From ldv at altlinux.org  Sat Aug  1 12:29:23 2020
From: ldv at altlinux.org (Dmitry V. Levin)
Date: Sat, 1 Aug 2020 15:29:23 +0300
Subject: [PATCH v4 1/7] PID namespace translation support
In-Reply-To: <CAJrAtOXCg+oR0WGs0++6tg_3a-QhZ8kupLmcGTWUim03OPCn8A@mail.gmail.com>
References: <20200727185410.2503993-1-uzonyi.akos@gmail.com>
 <20200727185410.2503993-2-uzonyi.akos@gmail.com>
 <20200731184127.GA23929@altlinux.org>
 <CAJrAtOXCg+oR0WGs0++6tg_3a-QhZ8kupLmcGTWUim03OPCn8A@mail.gmail.com>
Message-ID: <20200801122923.GA2879@altlinux.org>

On Fri, Jul 31, 2020 at 09:41:30PM +0200, ?kos Uzonyi wrote:
> On Fri, 31 Jul 2020 at 20:41, Dmitry V. Levin <ldv at altlinux.org> wrote:
> > On Mon, Jul 27, 2020 at 08:54:04PM +0200, ?kos Uzonyi wrote:
> [...]
> > > +static bool
> > > +is_proc_ours(void)
> > > +{
> > > +     static int cached_val = -1;
> > > +
> > > +     if (cached_val < 0)
> > > +             cached_val = get_id_list(0, NULL, PT_TID) == 1;
> > > +
> > > +     return cached_val;
> > > +}
> > > +
> > > +static uint64_t
> > > +get_ns(struct tcb *tcp)
> > > +{
> > > +     if (!tcp->pid_ns_inited) {
> > > +             int proc_pid = 0;
> > > +
> > > +             if (is_proc_ours())
> > > +                     proc_pid = tcp->pid;
> > > +             else
> > > +                     translate_pid(NULL, tcp->pid, PT_TID, &proc_pid);
> > > +
> > > +             if (proc_pid)
> > > +                     get_ns_hierarchy(proc_pid, &tcp->pid_ns, 1);
> > > +
> > > +             tcp->pid_ns_inited = true;
> > > +     }
> > > +
> > > +     return tcp->pid_ns;
> > > +}
> > > +
> > > +static uint64_t
> > > +get_our_ns(void)
> > > +{
> > > +     static uint64_t our_ns = 0;
> > > +     static bool our_ns_initialised = false;
> > > +
> > > +     if (!our_ns_initialised) {
> > > +             get_ns_hierarchy(0, &our_ns, 1);
> > > +             our_ns_initialised = true;
> > > +     }
> > > +
> > > +     return our_ns;
> > > +}
> >
> > Could you add some short comments describing the purpose of these
> > functions, similar to other functions in this file, please?
> 
> Ok, I'll add short documentations to these functions, and maybe some
> other functions as well.

It would be great if you could also add a comment about the choice of
numeric constants passed as arguments to trie_create in pidns_init and
put_proc_pid.


-- 
ldv

From ldv at altlinux.org  Sat Aug  1 12:52:51 2020
From: ldv at altlinux.org (Dmitry V. Levin)
Date: Sat, 1 Aug 2020 15:52:51 +0300
Subject: [PATCH v4 4/7] Add SYS_FUNC(tkill)
In-Reply-To: <20200727185410.2503993-5-uzonyi.akos@gmail.com>
References: <20200727185410.2503993-1-uzonyi.akos@gmail.com>
 <20200727185410.2503993-5-uzonyi.akos@gmail.com>
Message-ID: <20200801125251.GA3038@altlinux.org>

On Mon, Jul 27, 2020 at 08:54:07PM +0200, ?kos Uzonyi wrote:
> syscallent*.h files are updated automatically by:
> find linux -name syscallent*.h -exec \
>         sed -i '/"tkill"/ s/SEN(kill)/SEN(tkill)/' {} +
> 
> * signal.c (tkill): New syscall decoder.
> * linux/32/syscallent.h: Use SEN(tkill) for "tkill" syscall.

I think it would be better if this commit was split into two parts:
the first one that introduces a tkill syscall decoder, and the second part
that makes the tkill syscall decoder use printpid.  The second part then
should be merged into "Use printpid in decoders" commit that updates
decoders of kill and tgkill syscalls.

Does this make sense?


-- 
ldv

From uzonyi.akos at gmail.com  Sat Aug  1 13:50:20 2020
From: uzonyi.akos at gmail.com (=?UTF-8?B?w4Frb3MgVXpvbnlp?=)
Date: Sat, 1 Aug 2020 15:50:20 +0200
Subject: [PATCH v4 4/7] Add SYS_FUNC(tkill)
In-Reply-To: <20200801125251.GA3038@altlinux.org>
References: <20200727185410.2503993-1-uzonyi.akos@gmail.com>
 <20200727185410.2503993-5-uzonyi.akos@gmail.com>
 <20200801125251.GA3038@altlinux.org>
Message-ID: <CAJrAtOXew8kOb2G5qKQ7Qc2iQ_5WkFiB-gY-1Z9RMQoAtMrafQ@mail.gmail.com>

On Sat, 1 Aug 2020 at 14:52, Dmitry V. Levin <ldv at altlinux.org> wrote:
> On Mon, Jul 27, 2020 at 08:54:07PM +0200, ?kos Uzonyi wrote:
> > syscallent*.h files are updated automatically by:
> > find linux -name syscallent*.h -exec \
> >         sed -i '/"tkill"/ s/SEN(kill)/SEN(tkill)/' {} +
> >
> > * signal.c (tkill): New syscall decoder.
> > * linux/32/syscallent.h: Use SEN(tkill) for "tkill" syscall.
>
> I think it would be better if this commit was split into two parts:
> the first one that introduces a tkill syscall decoder, and the second part
> that makes the tkill syscall decoder use printpid.  The second part then
> should be merged into "Use printpid in decoders" commit that updates
> decoders of kill and tgkill syscalls.
>
> Does this make sense?

Yes, that makes sense, I will do it.

Also I'm not sure if "Use printpid in decoders" and "Use printpid in
print_sockaddr and printsiginfo" should be two different commits. I
didn't squash them together, because the latter one adds a tcp
parameter to a lot of functions so I thought it could be cleaner to
keep them separate. But since logically these two commits should be
one, I think I should squash them. Do you agree?

From ldv at altlinux.org  Sat Aug  1 13:51:29 2020
From: ldv at altlinux.org (Dmitry V. Levin)
Date: Sat, 1 Aug 2020 16:51:29 +0300
Subject: [PATCH v4 1/7] PID namespace translation support
In-Reply-To: <20200727185410.2503993-2-uzonyi.akos@gmail.com>
References: <20200727185410.2503993-1-uzonyi.akos@gmail.com>
 <20200727185410.2503993-2-uzonyi.akos@gmail.com>
Message-ID: <20200801135129.GA3674@altlinux.org>

On Mon, Jul 27, 2020 at 08:54:04PM +0200, ?kos Uzonyi wrote:
[...]
> @@ -983,6 +1001,11 @@ print_local_array_ex(struct tcb *tcp,
>  extern kernel_ulong_t *
>  fetch_indirect_syscall_args(struct tcb *, kernel_ulong_t addr, unsigned int n_args);
>  
> +extern void pidns_init(void);
> +
> +extern int translate_pid(struct tcb *tcp, int dest_id, enum pid_type type,
> +		    int *proc_pid_ptr);
> +
>  extern void
>  dumpiov_in_msghdr(struct tcb *, kernel_ulong_t addr, kernel_ulong_t data_size);
>  
> @@ -1058,6 +1081,8 @@ printfd(struct tcb *tcp, int fd)
>   * of the tracee the descriptor tcp).  This is a stub.
>   */
>  extern void printfd_pid_tracee_ns(struct tcb *tcp, pid_t pid, int fd);
> +extern void printpid(struct tcb *tcp, int pid, enum pid_type type);
> +extern void printpid_translation(struct tcb *tcp, int pid, enum pid_type type);
>  extern void print_sockaddr(const void *sa, int len);
>  extern bool
>  print_inet_addr(int af, const void *addr, unsigned int len, const char *var_name);

There is no strict rule, but in general we prefer "struct tcb *"
to "struct tcb *tcp" in function declarations because the former
is 3 symbols shorter and the latter does not add any more clarity.


-- 
ldv

From ldv at altlinux.org  Sat Aug  1 13:57:11 2020
From: ldv at altlinux.org (Dmitry V. Levin)
Date: Sat, 1 Aug 2020 16:57:11 +0300
Subject: [PATCH v4 4/7] Add SYS_FUNC(tkill)
In-Reply-To: <CAJrAtOXew8kOb2G5qKQ7Qc2iQ_5WkFiB-gY-1Z9RMQoAtMrafQ@mail.gmail.com>
References: <20200727185410.2503993-1-uzonyi.akos@gmail.com>
 <20200727185410.2503993-5-uzonyi.akos@gmail.com>
 <20200801125251.GA3038@altlinux.org>
 <CAJrAtOXew8kOb2G5qKQ7Qc2iQ_5WkFiB-gY-1Z9RMQoAtMrafQ@mail.gmail.com>
Message-ID: <20200801135711.GB3674@altlinux.org>

On Sat, Aug 01, 2020 at 03:50:20PM +0200, ?kos Uzonyi wrote:
> On Sat, 1 Aug 2020 at 14:52, Dmitry V. Levin <ldv at altlinux.org> wrote:
> > On Mon, Jul 27, 2020 at 08:54:07PM +0200, ?kos Uzonyi wrote:
> > > syscallent*.h files are updated automatically by:
> > > find linux -name syscallent*.h -exec \
> > >         sed -i '/"tkill"/ s/SEN(kill)/SEN(tkill)/' {} +
> > >
> > > * signal.c (tkill): New syscall decoder.
> > > * linux/32/syscallent.h: Use SEN(tkill) for "tkill" syscall.
> >
> > I think it would be better if this commit was split into two parts:
> > the first one that introduces a tkill syscall decoder, and the second part
> > that makes the tkill syscall decoder use printpid.  The second part then
> > should be merged into "Use printpid in decoders" commit that updates
> > decoders of kill and tgkill syscalls.
> >
> > Does this make sense?
> 
> Yes, that makes sense, I will do it.
> 
> Also I'm not sure if "Use printpid in decoders" and "Use printpid in
> print_sockaddr and printsiginfo" should be two different commits. I
> didn't squash them together, because the latter one adds a tcp
> parameter to a lot of functions so I thought it could be cleaner to
> keep them separate. But since logically these two commits should be
> one, I think I should squash them. Do you agree?

I think those changes that just add "struct tcb *" argument here and
there can now be moved to a separate commit (I'm currently testing this
in ldv/next branch), and both "Use printpid" commits would indeed
be better merged together.


-- 
ldv

From ldv at altlinux.org  Sun Aug  2 12:08:27 2020
From: ldv at altlinux.org (Dmitry V. Levin)
Date: Sun, 2 Aug 2020 15:08:27 +0300
Subject: [PATCH v4 4/7] Add SYS_FUNC(tkill)
In-Reply-To: <20200801135711.GB3674@altlinux.org>
References: <20200727185410.2503993-1-uzonyi.akos@gmail.com>
 <20200727185410.2503993-5-uzonyi.akos@gmail.com>
 <20200801125251.GA3038@altlinux.org>
 <CAJrAtOXew8kOb2G5qKQ7Qc2iQ_5WkFiB-gY-1Z9RMQoAtMrafQ@mail.gmail.com>
 <20200801135711.GB3674@altlinux.org>
Message-ID: <20200802120826.GA16944@altlinux.org>

On Sat, Aug 01, 2020 at 04:57:11PM +0300, Dmitry V. Levin wrote:
> On Sat, Aug 01, 2020 at 03:50:20PM +0200, ?kos Uzonyi wrote:
> > On Sat, 1 Aug 2020 at 14:52, Dmitry V. Levin <ldv at altlinux.org> wrote:
> > > On Mon, Jul 27, 2020 at 08:54:07PM +0200, ?kos Uzonyi wrote:
> > > > syscallent*.h files are updated automatically by:
> > > > find linux -name syscallent*.h -exec \
> > > >         sed -i '/"tkill"/ s/SEN(kill)/SEN(tkill)/' {} +
> > > >
> > > > * signal.c (tkill): New syscall decoder.
> > > > * linux/32/syscallent.h: Use SEN(tkill) for "tkill" syscall.
> > >
> > > I think it would be better if this commit was split into two parts:
> > > the first one that introduces a tkill syscall decoder, and the second part
> > > that makes the tkill syscall decoder use printpid.  The second part then
> > > should be merged into "Use printpid in decoders" commit that updates
> > > decoders of kill and tgkill syscalls.
> > >
> > > Does this make sense?
> > 
> > Yes, that makes sense, I will do it.
> > 
> > Also I'm not sure if "Use printpid in decoders" and "Use printpid in
> > print_sockaddr and printsiginfo" should be two different commits. I
> > didn't squash them together, because the latter one adds a tcp
> > parameter to a lot of functions so I thought it could be cleaner to
> > keep them separate. But since logically these two commits should be
> > one, I think I should squash them. Do you agree?
> 
> I think those changes that just add "struct tcb *" argument here and
> there can now be moved to a separate commit (I'm currently testing this
> in ldv/next branch), and both "Use printpid" commits would indeed
> be better merged together.

OK, I've pushed these changes to master.  When you rebase, there are going
to be a few simple conflicts to resolve.


-- 
ldv

From uzonyi.akos at gmail.com  Mon Aug  3 19:19:11 2020
From: uzonyi.akos at gmail.com (=?UTF-8?q?=C3=81kos=20Uzonyi?=)
Date: Mon,  3 Aug 2020 21:19:11 +0200
Subject: [PATCH v5 0/5] [PIDNS] Final
Message-ID: <20200803191916.94724-1-uzonyi.akos@gmail.com>

From: Uzonyi ?kos <uzonyi.akos at gmail.com>

Changes in v5:
  - Squash "Use printpid in *" commits
  - Makefile.am: move adding getpid.c to "Use printpid in decoders"
  - Remove pid_ns_inited field from struct tcb
  - strace.1.in: remove -Y flag
  - Use tprints instead of tprintf where possible
  - Make some global variables static
  - pidns_init: remove "inited" bool variable
  - Make printpid_translation static
  - tests/pidns.c: refactor a bit
  - check_ns_ioctl: fix error msg
  - defs.h: Move adding get_proc_pid to "PID namespace translation support"
  - Remove tcp paramter name from declarations
  - Update printfd_pid_tracee_ns documentation
  - Use named constants for trie_create arguments
  - Add documentation comments
  - Add printpid_tgid_pgid function
  - Delete get_pid_max function; use global variables instead
  - Refactor trie:
    - Move key_size argument
    - Remove support for TRIE_SET
    - Merge trie_create, trie_init, trie_check functions
    - trie_free_node: make static, fix "node" argument type
    - Add max_depth field
    - Reorder functions
    - Extract common parts of trie_get, trie_set
Changes in v4:
  - Skip tests if NS_* ioctl commands are not supported
  - Improve documentation in pidns.h
  - Use pipe for init process termination (instead of SIGKILL)
  - Add PIDNS_TEST_INIT macro
  - Remove "ifdef __NR_gettid"
  - Fix fork--pidns-tranlsation.test: skip if unshare fails with EPERM
  - Use debug message instead of normal message in some cases
  - Rename some labels
  - Rewrite get_ns function
  - Remove O_NONBLOCK from open(/proc/<pid>/ns/pid)
Changes in v3:
  - Split accidentally sqashed last commit
  - Undo modification of tests/pidfd_send_signal.c
  - Rename kcmp-yY test to kcmp-y--pidns-translation
  - Skip tests if unshare fails with EPERM
  - Fix buffer size in pidns_pid2str
  - Use largefile_wrappers.h macros
  - Return early if from_ns or our_ns is 0
  - Do not call ioctl(NS_GET_PARENT) again, if first failed with ENOTTY
  - Skip pidns tests if Linux kernel version < 4.9
  - Use smaller trie nodes in pidns.c
  - Remove race condition from fork--pidns-translation test
  - Move "key_size" to center in trie description
  - Use PT_TID (not PT_TGID) when translating tcp->pid
  - Fix get_ns_hierarchy and get_id_list functions
  - Fix migrate_pages test if syscall succeds
  - Fix filtering in ioctl_block--pidns-translation.test
  - Fix -a flag value in xetpriority test
Changes in v2:
  - Add missing header files to Makefile
  - Fix pointer-to-int-cast errors
  - Fix unused-result errors
  - Use perror_msg instead of perror_func_msg where appropriate
  - Remove tcb parameter of read_int_from_file
  - Use xsprintf instead of snprintf
  - Refactor get_pid_max, get_ns_hierarchy, get_id_list functions
  - Remove -Y flag
  - Improve documentation of trie
  - Fix printing of f_owner_ex struct
  - Use printpid for F_GETOWN, F_SETOWN fcntl command arguments
  - Use printpid for shmid_ds.shm_cpid, shmid_ds.shm_clid
  - Call pidns_init before parsing arguments

?kos Uzonyi (5):
  PID namespace translation support
  Use printpid in decoders
  Use get_proc_pid for /proc paths
  Implement testing framework for pidns
  Add tests for PID namespace translation

 Makefile.am                                   |   4 +
 NEWS                                          |   1 +
 affinity.c                                    |   6 +-
 block.c                                       |   2 +-
 bpf.c                                         |   2 +-
 capability.c                                  |   4 +-
 clone.c                                       |  14 +-
 defs.h                                        |  58 +-
 fcntl.c                                       |  24 +-
 get_robust_list.c                             |   3 +-
 getpid.c                                      |  46 ++
 ioprio.c                                      |  26 +-
 ipc_shmctl.c                                  |   5 +-
 kcmp.c                                        |   5 +-
 largefile_wrappers.h                          |   2 +
 linux/dummy.h                                 |   8 +-
 mmap_cache.c                                  |   2 +-
 msghdr.c                                      |   2 +-
 net.c                                         |   2 +-
 netlink.c                                     |   5 +-
 numa.c                                        |   6 +-
 pathtrace.c                                   |   5 +-
 pidfd_open.c                                  |   2 +-
 pidns.c                                       | 597 ++++++++++++++++++
 print_fields.h                                |  24 +
 printsiginfo.c                                |   2 +-
 process.c                                     |   3 +-
 process_vm.c                                  |   6 +-
 resource.c                                    |  27 +-
 sched.c                                       |  25 +-
 signal.c                                      |  21 +-
 sockaddr.c                                    |   2 +-
 strace.1.in                                   |   4 +
 strace.c                                      |  11 +-
 syscall.c                                     |  15 +
 tests/.gitignore                              |  31 +
 tests/Makefile.am                             |  37 ++
 tests/fcntl--pidns-translation.c              |   2 +
 tests/fcntl-common.c                          |  82 ++-
 tests/fcntl.c                                 |   1 +
 tests/fcntl64--pidns-translation.c            |   2 +
 tests/fcntl64.c                               |   3 +
 tests/fork--pidns-translation.awk             |  15 +
 tests/fork--pidns-translation.c               |  69 ++
 tests/fork--pidns-translation.test            |  16 +
 tests/gen_tests.in                            |  30 +-
 tests/getpgrp--pidns-translation.c            |   2 +
 tests/getpgrp.c                               |   8 +-
 tests/getpid--pidns-translation.c             |   2 +
 tests/getpid.c                                |   8 +-
 tests/getsid--pidns-translation.c             |   2 +
 tests/getsid.c                                |   9 +-
 tests/gettid--pidns-translation.c             |   2 +
 tests/gettid.c                                |   8 +-
 tests/init.sh                                 |  31 +
 tests/ioctl_block--pidns-translation.c        |   2 +
 tests/ioctl_block--pidns-translation.test     |  24 +
 tests/ioctl_block.c                           |  24 +-
 tests/ioprio--pidns-translation.c             |   2 +
 tests/ioprio.c                                |  54 +-
 tests/kcmp-y--pidns-translation.c             |   2 +
 tests/kcmp.c                                  |  36 +-
 tests/kill--pidns-translation.c               |   2 +
 tests/kill.c                                  |  12 +-
 tests/migrate_pages--pidns-translation.c      |   2 +
 tests/migrate_pages.c                         |  17 +-
 tests/move_pages--pidns-translation.c         |   2 +
 tests/move_pages.c                            |  51 +-
 tests/net-sockaddr--pidns-translation.c       |   2 +
 tests/net-sockaddr.c                          |  66 +-
 tests/netlink_audit--pidns-translation.c      |   2 +
 tests/netlink_audit--pidns-translation.test   |  13 +
 tests/netlink_audit.c                         |  11 +-
 tests/pidfd_open--pidns-translation.c         |   2 +
 tests/pidfd_open.c                            |  21 +-
 tests/pidfd_send_signal--pidns-translation.c  |   2 +
 tests/pidfd_send_signal.c                     |  13 +-
 tests/pidns.c                                 | 214 +++++++
 tests/pidns.h                                 |  56 ++
 tests/prlimit64--pidns-translation.c          |   2 +
 tests/prlimit64.c                             |  17 +-
 tests/process_vm_readv--pidns-translation.c   |   2 +
 tests/process_vm_readv_writev.c               |  27 +-
 tests/process_vm_writev--pidns-translation.c  |   2 +
 tests/rt_sigqueueinfo--pidns-translation.c    |   2 +
 tests/rt_sigqueueinfo.c                       |  15 +-
 tests/rt_tgsigqueueinfo--pidns-translation.c  |   2 +
 tests/rt_tgsigqueueinfo.c                     |  26 +-
 tests/sched_xetaffinity--pidns-translation.c  |   2 +
 tests/sched_xetaffinity.c                     |  31 +-
 tests/sched_xetattr--pidns-translation.c      |   2 +
 tests/sched_xetattr.c                         |  47 +-
 tests/sched_xetparam--pidns-translation.c     |   2 +
 tests/sched_xetparam.c                        |  20 +-
 tests/sched_xetscheduler--pidns-translation.c |   2 +
 tests/sched_xetscheduler.c                    |  44 +-
 tests/signal_receive--pidns-translation.c     |   2 +
 tests/signal_receive.c                        |  22 +-
 tests/so_peercred--pidns-translation.c        |   2 +
 tests/so_peercred.c                           |  22 +
 tests/xet_robust_list--pidns-translation.c    |   2 +
 tests/xet_robust_list.c                       |  18 +-
 tests/xetpgid--pidns-translation.c            |   2 +
 tests/xetpgid.c                               |  21 +-
 tests/xetpriority--pidns-translation.c        |   2 +
 tests/xetpriority.c                           |  20 +-
 trie.c                                        | 250 ++++++++
 trie.h                                        |  89 +++
 util.c                                        |  27 +-
 wait.c                                        |  36 +-
 110 files changed, 2468 insertions(+), 255 deletions(-)
 create mode 100644 getpid.c
 create mode 100644 pidns.c
 create mode 100644 tests/fcntl--pidns-translation.c
 create mode 100644 tests/fcntl64--pidns-translation.c
 create mode 100644 tests/fork--pidns-translation.awk
 create mode 100644 tests/fork--pidns-translation.c
 create mode 100755 tests/fork--pidns-translation.test
 create mode 100644 tests/getpgrp--pidns-translation.c
 create mode 100644 tests/getpid--pidns-translation.c
 create mode 100644 tests/getsid--pidns-translation.c
 create mode 100644 tests/gettid--pidns-translation.c
 create mode 100644 tests/ioctl_block--pidns-translation.c
 create mode 100755 tests/ioctl_block--pidns-translation.test
 create mode 100644 tests/ioprio--pidns-translation.c
 create mode 100644 tests/kcmp-y--pidns-translation.c
 create mode 100644 tests/kill--pidns-translation.c
 create mode 100644 tests/migrate_pages--pidns-translation.c
 create mode 100644 tests/move_pages--pidns-translation.c
 create mode 100644 tests/net-sockaddr--pidns-translation.c
 create mode 100644 tests/netlink_audit--pidns-translation.c
 create mode 100755 tests/netlink_audit--pidns-translation.test
 create mode 100644 tests/pidfd_open--pidns-translation.c
 create mode 100644 tests/pidfd_send_signal--pidns-translation.c
 create mode 100644 tests/pidns.c
 create mode 100644 tests/pidns.h
 create mode 100644 tests/prlimit64--pidns-translation.c
 create mode 100644 tests/process_vm_readv--pidns-translation.c
 create mode 100644 tests/process_vm_writev--pidns-translation.c
 create mode 100644 tests/rt_sigqueueinfo--pidns-translation.c
 create mode 100644 tests/rt_tgsigqueueinfo--pidns-translation.c
 create mode 100644 tests/sched_xetaffinity--pidns-translation.c
 create mode 100644 tests/sched_xetattr--pidns-translation.c
 create mode 100644 tests/sched_xetparam--pidns-translation.c
 create mode 100644 tests/sched_xetscheduler--pidns-translation.c
 create mode 100644 tests/signal_receive--pidns-translation.c
 create mode 100644 tests/so_peercred--pidns-translation.c
 create mode 100644 tests/xet_robust_list--pidns-translation.c
 create mode 100644 tests/xetpgid--pidns-translation.c
 create mode 100644 tests/xetpriority--pidns-translation.c
 create mode 100644 trie.c
 create mode 100644 trie.h

--
2.27.0


From uzonyi.akos at gmail.com  Mon Aug  3 19:19:12 2020
From: uzonyi.akos at gmail.com (=?UTF-8?q?=C3=81kos=20Uzonyi?=)
Date: Mon,  3 Aug 2020 21:19:12 +0200
Subject: [PATCH v5 1/5] PID namespace translation support
In-Reply-To: <20200803191916.94724-1-uzonyi.akos@gmail.com>
References: <20200803191916.94724-1-uzonyi.akos@gmail.com>
Message-ID: <20200803191916.94724-2-uzonyi.akos@gmail.com>

* defs.h (pidns_translation): New variable.
(tcb): Add pid_ns field.
(RVAL_MASK): Change value from 013 to 017.
(RVAL_TID, RVAL_SID, RVAL_TGID, RVAL_PGID): New definitions.
(pid_type): New enum.
(pidns_init, translate_pid, get_proc_pid, printpid, printpid_tgid_pgid):
New function declarations.
* largefile_wrappers.h (fstat_fd): New macro.
* pidns.c: New file.
* trie.c: New file.
* trie.h: New file.
* Makefile.am (libstrace_a_SOURCES): Add trie.c, trie.h, pidns.c.
* strace.c (pidns_translation): New variable.
(init): Add --pidns-translation option.
* syscall.c (syscall_exiting_trace): Handle RVAL_* return values.
* NEWS: Mention this.
* strace.1.in: Add description for new option.

Co-Authored-by: Eugene Syromyatnikov <evgsyr at gmail.com>
---
 Makefile.am          |   3 +
 NEWS                 |   1 +
 defs.h               |  53 +++-
 largefile_wrappers.h |   2 +
 pidns.c              | 597 +++++++++++++++++++++++++++++++++++++++++++
 strace.1.in          |   4 +
 strace.c             |   9 +
 syscall.c            |  15 ++
 trie.c               | 250 ++++++++++++++++++
 trie.h               |  89 +++++++
 10 files changed, 1022 insertions(+), 1 deletion(-)
 create mode 100644 pidns.c
 create mode 100644 trie.c
 create mode 100644 trie.h

diff --git a/Makefile.am b/Makefile.am
index f5447811..73c22035 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -233,6 +233,7 @@ libstrace_a_SOURCES =	\
 	personality.c	\
 	pidfd_getfd.c	\
 	pidfd_open.c	\
+	pidns.c		\
 	pkeys.c		\
 	poll.c		\
 	prctl.c		\
@@ -344,6 +345,8 @@ libstrace_a_SOURCES =	\
 	time.c		\
 	times.c		\
 	trace_event.h	\
+	trie.c 		\
+	trie.h 		\
 	truncate.c	\
 	ubi.c		\
 	ucopy.c		\
diff --git a/NEWS b/NEWS
index b83f9e80..9086fde9 100644
--- a/NEWS
+++ b/NEWS
@@ -14,6 +14,7 @@ Noteworthy changes in release ?.? (????-??-??)
     KEYCTL_*, KVM_*, LOOP_*, NDA_*, RTC_*, TCA_*, STATX_*, and *_MAGIC
     constants.
   * Updated lists of ioctl commands from Linux 5.8.
+  * Added --pidns-translation opition for PID namespace translation.
 
 * Bug fixes
   * Added statx syscall to %fstat trace class.
diff --git a/defs.h b/defs.h
index f7ac54f3..c16feb3c 100644
--- a/defs.h
+++ b/defs.h
@@ -280,6 +280,13 @@ struct tcb {
 	struct timespec etime;	/* Syscall entry time (CLOCK_MONOTONIC) */
 	struct timespec delay_expiration_time; /* When does the delay end */
 
+	/*
+	 * The ID of the PID namespace of this process
+	 * (inode number of /proc/<pid>/ns/pid)
+	 * (0: not initialized; -1ULL: initializtaion failed)
+	 */
+	uint64_t pid_ns;
+
 	struct mmap_cache_t *mmap_cache;
 
 	/*
@@ -413,7 +420,11 @@ extern const struct xlat whence_codes[];
 # define RVAL_HEX	001	/* hex format */
 # define RVAL_OCTAL	002	/* octal format */
 # define RVAL_FD		010	/* file descriptor */
-# define RVAL_MASK	013	/* mask for these values */
+# define RVAL_TID	011	/* task ID */
+# define RVAL_SID	012	/* session ID */
+# define RVAL_TGID	013	/* thread group ID */
+# define RVAL_PGID	014	/* process group ID */
+# define RVAL_MASK	017	/* mask for these values */
 
 # define RVAL_STR	020	/* Print `auxstr' field after return val */
 # define RVAL_NONE	040	/* Print nothing */
@@ -428,6 +439,16 @@ extern const struct xlat whence_codes[];
 
 # define indirect_ipccall(tcp) (tcp_sysent(tcp)->sys_flags & TRACE_INDIRECT_SUBCALL)
 
+enum pid_type {
+	PT_TID,
+	PT_TGID,
+	PT_PGID,
+	PT_SID,
+
+	PT_COUNT,
+	PT_NONE = -1
+};
+
 enum sock_proto {
 	SOCK_PROTO_UNKNOWN,
 	SOCK_PROTO_UNIX,
@@ -469,6 +490,7 @@ extern int Tflag_scale;
 extern int Tflag_width;
 extern bool iflag;
 extern bool count_wallclock;
+extern unsigned int pidns_translation;
 /* are we filtering traces based on paths? */
 extern struct path_set {
 	const char **paths_selected;
@@ -983,6 +1005,27 @@ print_local_array_ex(struct tcb *tcp,
 extern kernel_ulong_t *
 fetch_indirect_syscall_args(struct tcb *, kernel_ulong_t addr, unsigned int n_args);
 
+extern void pidns_init(void);
+
+/**
+ * Returns the pid of the tracee as present in /proc (can be different from
+ * tcp->pid if /proc and the tracee process are in different PID namespaces).
+ */
+extern int get_proc_pid(struct tcb *);
+
+/**
+ * Translates a pid from tracee's namespace to our namepace.
+ *
+ * @param tcp             The tcb of the tracee
+ *                        (NULL: from_id is in strace's namespace. Useful for
+ *                         getting the proc PID of from_id)
+ * @param from_id         The id to be translated
+ * @param type            The PID type of from_id
+ * @param proc_pid_ptr    If not NULL, writes the proc PID to this location
+ */
+extern int translate_pid(struct tcb *, int dest_id, enum pid_type type,
+		    int *proc_pid_ptr);
+
 extern void
 dumpiov_in_msghdr(struct tcb *, kernel_ulong_t addr, kernel_ulong_t data_size);
 
@@ -1058,6 +1101,14 @@ printfd(struct tcb *tcp, int fd)
  * of the tracee the descriptor tcp).  This is a stub.
  */
 extern void printfd_pid_tracee_ns(struct tcb *tcp, pid_t pid, int fd);
+
+extern void printpid(struct tcb *, int pid, enum pid_type type);
+
+/**
+ * Prints pid as a TGID if positive, and PGID if negative
+ * (like the first argument of kill).
+ */
+extern void printpid_tgid_pgid(struct tcb *, int pid);
 extern void print_sockaddr(struct tcb *, const void *sa, int len);
 extern bool
 print_inet_addr(int af, const void *addr, unsigned int len, const char *var_name);
diff --git a/largefile_wrappers.h b/largefile_wrappers.h
index 116e7048..9d8f5c92 100644
--- a/largefile_wrappers.h
+++ b/largefile_wrappers.h
@@ -29,6 +29,7 @@
 #  else
 #   define fcntl_fd fcntl
 #  endif
+#  define fstat_fd fstat64
 #  define strace_stat_t struct stat64
 #  define stat_file stat64
 #  define struct_dirent struct dirent64
@@ -39,6 +40,7 @@
 #  define open_file open
 #  define fopen_stream fopen
 #  define fcntl_fd fcntl
+#  define fstat_fd fstat
 #  define strace_stat_t struct stat
 #  define stat_file stat
 #  define struct_dirent struct dirent
diff --git a/pidns.c b/pidns.c
new file mode 100644
index 00000000..6d46cb11
--- /dev/null
+++ b/pidns.c
@@ -0,0 +1,597 @@
+/*
+ * Copyright (c) 2020 ?kos Uzonyi <uzonyi.akos at gmail.com>
+ * All rights reserved.
+ *
+ * SPDX-License-Identifier: LGPL-2.1-or-later
+ */
+
+#include "defs.h"
+
+
+#include <dirent.h>
+#include <fcntl.h>
+#include <stdint.h>
+#include <string.h>
+#include <unistd.h>
+
+#include <asm/unistd.h>
+
+#include <sys/ioctl.h>
+#include <sys/param.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+
+#include "largefile_wrappers.h"
+#include "trie.h"
+#include "nsfs.h"
+#include "xmalloc.h"
+#include "xstring.h"
+
+/**
+ * Key:   PID NS ID
+ * Value: a btree:
+ *           Key:   a process PID in NS
+ *           Value: the process's PID as present in /proc
+ */
+static struct trie *ns_pid_to_proc_pid[PT_COUNT];
+
+/**
+ * Key:   Proc PID
+ * Value: stuct proc_data
+ */
+static struct trie *proc_data_cache;
+
+static bool ns_get_parent_enotty = false;
+
+static const char tid_str[]  = "NSpid:\t";
+static const char tgid_str[] = "NStgid:\t";
+static const char pgid_str[] = "NSpgid:\t";
+static const char sid_str[]  = "NSsid:\t";
+
+static const struct {
+	const char *str;
+	size_t size;
+} id_strs[PT_COUNT] = {
+	[PT_TID] =  { tid_str,  sizeof(tid_str)  - 1 },
+	[PT_TGID] = { tgid_str, sizeof(tgid_str) - 1 },
+	[PT_PGID] = { pgid_str, sizeof(pgid_str) - 1 },
+	[PT_SID] =  { sid_str,  sizeof(sid_str)  - 1 },
+};
+
+
+/**
+ * Limit on PID NS hierarchy depth, imposed since Linux 3.7. NS traversal
+ * is not possible before Linux 4.9, so we consider this limit pretty universal.
+ */
+#define MAX_NS_DEPTH 32
+
+static const uint8_t ptr_sz_lg = (sizeof(uint64_t *) == 8 ? 6 : 5);
+
+static int pid_max;
+static uint8_t pid_max_size, pid_max_size_lg;
+
+struct proc_data {
+	int proc_pid;
+	int ns_count;
+	uint64_t ns_hierarchy[MAX_NS_DEPTH];
+	int id_count[PT_COUNT];
+	int id_hierarchy[PT_COUNT][MAX_NS_DEPTH];
+};
+
+void
+pidns_init(void)
+{
+	if (proc_data_cache)
+		return;
+
+	pid_max = INT_MAX;
+	if (read_int_from_file("/proc/sys/kernel/pid_max", &pid_max) < 0)
+		debug_func_perror_msg("reading /proc/sys/kernel/pid_max");
+	pid_max_size = ilog2_32(pid_max - 1) + 1;
+	pid_max_size_lg = ilog2_32(pid_max_size - 1) + 1;
+
+	for (int i = 0; i < PT_COUNT; i++)
+		ns_pid_to_proc_pid[i] = trie_create(64, ptr_sz_lg, 10, 10, 0);
+
+	proc_data_cache = trie_create(pid_max_size, ptr_sz_lg, 10, 10, 0);
+}
+
+static void
+put_proc_pid(uint64_t ns, int ns_pid, enum pid_type type, int proc_pid)
+{
+	struct trie *b = (struct trie *) (uintptr_t) trie_get(ns_pid_to_proc_pid[type], ns);
+	if (!b) {
+		b = trie_create(pid_max_size, pid_max_size_lg, 10, 10, 0);
+		trie_set(ns_pid_to_proc_pid[type], ns, (uint64_t) (uintptr_t) b);
+	}
+	trie_set(b, ns_pid, proc_pid);
+}
+
+static int
+get_cached_proc_pid(uint64_t ns, int ns_pid, enum pid_type type)
+{
+	struct trie *b = (struct trie *) (uintptr_t)
+		trie_get(ns_pid_to_proc_pid[type], ns);
+	if (!b)
+		return 0;
+
+	return trie_get(b, ns_pid);
+}
+
+/**
+ * Helper function, converts pid to string, or to "self" for pid == 0.
+ * Uses static buffer for operation.
+ */
+static const char *
+pid_to_str(pid_t pid)
+{
+	if (!pid)
+		return "self";
+
+	static char buf[sizeof("-2147483648")];
+	xsprintf(buf, "%d", pid);
+	return buf;
+}
+
+/**
+ * Returns a list of PID NS IDs for the specified PID.
+ *
+ * @param proc_pid PID (as present in /proc) to get information for.
+ * @param ns_buf   Pointer to buffer that is able to contain at least
+ *                 ns_buf_size items.
+ * @return         Amount of NS in list. 0 indicates error.
+ */
+static size_t
+get_ns_hierarchy(int proc_pid, uint64_t *ns_buf, size_t ns_buf_size)
+{
+	char path[PATH_MAX + 1];
+	xsprintf(path, "/proc/%s/ns/pid", pid_to_str(proc_pid));
+
+	int fd = open_file(path, O_RDONLY);
+	if (fd < 0)
+		return 0;
+
+	size_t n = 0;
+	while (n < ns_buf_size) {
+		strace_stat_t st;
+		if (fstat_fd(fd, &st))
+			break;
+
+		ns_buf[n++] = st.st_ino;
+		if (n >= ns_buf_size)
+			break;
+
+		if (ns_get_parent_enotty)
+			break;
+
+		int parent_fd = ioctl(fd, NS_GET_PARENT);
+		if (parent_fd < 0) {
+			switch (errno) {
+			case EPERM:
+				break;
+
+			case ENOTTY:
+				ns_get_parent_enotty = true;
+				error_msg("NS_* ioctl commands are not "
+					  "supported by the kernel");
+				break;
+
+			default:
+				perror_func_msg("ioctl(NS_GET_PARENT)");
+				break;
+			}
+
+			break;
+		}
+
+		close(fd);
+		fd = parent_fd;
+	}
+
+	close(fd);
+
+	return n;
+}
+
+/**
+ * Get list of IDs present in NS* proc status record. IDs are placed as they are
+ * stored in /proc (from top to bottom of NS hierarchy).
+ *
+ * @param proc_pid    PID (as present in /proc) to get information for.
+ * @param id_buf      Pointer to buffer that is able to contain at least
+ *                    MAX_NS_DEPTH items. Can be NULL.
+ * @param type        Type of ID requested.
+ * @return            Number of items stored in id_list. 0 indicates error.
+ */
+static size_t
+get_id_list(int proc_pid, int *id_buf, enum pid_type type)
+{
+	const char *ns_str = id_strs[type].str;
+	size_t ns_str_size = id_strs[type].size;
+
+	size_t n = 0;
+
+	char status_path[PATH_MAX + 1];
+	xsprintf(status_path, "/proc/%s/status", pid_to_str(proc_pid));
+	FILE *f = fopen_stream(status_path, "r");
+	if (!f)
+		return 0;
+
+	char *line = NULL;
+	size_t linesize = 0;
+	char *p = NULL;
+
+	while (getline(&line, &linesize, f) > 0) {
+		if (strncmp(line, ns_str, ns_str_size) == 0) {
+			p = line + ns_str_size;
+			break;
+		}
+	}
+
+	while (p) {
+		errno = 0;
+		long id = strtol(p, NULL, 10);
+
+		if (errno || (id < 1) || (id > INT_MAX)) {
+			perror_func_msg("converting pid to int");
+			break;
+		}
+
+		if (id_buf)
+			id_buf[n] = (int) id;
+
+		n++;
+		strsep(&p, "\t");
+	}
+
+	free(line);
+	fclose(f);
+
+	return n;
+}
+
+/**
+ * Returns whether the /proc filesystem's PID namespace is same as strace's.
+ */
+static bool
+is_proc_ours(void)
+{
+	static int cached_val = -1;
+
+	if (cached_val < 0)
+		cached_val = get_id_list(0, NULL, PT_TID) == 1;
+
+	return cached_val;
+}
+
+/**
+ * Returns the PID namespace of the tracee
+ */
+static uint64_t
+get_ns(struct tcb *tcp)
+{
+	if (tcp->pid_ns == -1ULL)
+		return 0;
+
+	if (tcp->pid_ns)
+		return tcp->pid_ns;
+
+	int proc_pid = 0;
+	translate_pid(NULL, tcp->pid, PT_TID, &proc_pid);
+
+	tcp->pid_ns = -1ULL;
+	if (proc_pid)
+		get_ns_hierarchy(proc_pid, &tcp->pid_ns, 1);
+
+	return tcp->pid_ns;
+}
+
+/**
+ * Returns the PID namespace of strace
+ */
+static uint64_t
+get_our_ns(void)
+{
+	static uint64_t our_ns = 0;
+	static bool our_ns_initialised = false;
+
+	if (!our_ns_initialised) {
+		get_ns_hierarchy(0, &our_ns, 1);
+		our_ns_initialised = true;
+	}
+
+	return our_ns;
+}
+
+/**
+ * Returns the cached proc_data struct associated with proc_pid.
+ * If none found, allocates a new proc_data.
+ */
+static struct proc_data *
+get_or_create_proc_data(int proc_pid)
+{
+	struct proc_data *pd = (struct proc_data *) (uintptr_t)
+		trie_get(proc_data_cache, proc_pid);
+
+	if (!pd) {
+		pd = calloc(1, sizeof(*pd));
+		if (!pd)
+			return NULL;
+
+		pd->proc_pid = proc_pid;
+		trie_set(proc_data_cache, proc_pid, (uint64_t) (uintptr_t) pd);
+	}
+
+	return pd;
+}
+
+/**
+ * Updates the proc_data from /proc
+ * If the process does not exists, returns false, and frees the proc_data
+ */
+static bool
+update_proc_data(struct proc_data *pd, enum pid_type type)
+{
+	pd->ns_count = get_ns_hierarchy(pd->proc_pid,
+		pd->ns_hierarchy, MAX_NS_DEPTH);
+	if (!pd->ns_count)
+		goto fail;
+
+	pd->id_count[type] = get_id_list(pd->proc_pid,
+		pd->id_hierarchy[type], type);
+	if (!pd->id_count[type])
+		goto fail;
+
+	return true;
+
+fail:
+	trie_set(proc_data_cache, pd->proc_pid, (uint64_t) (uintptr_t) NULL);
+	free(pd);
+	return false;
+}
+
+/**
+ * Paramters for id translation
+ */
+struct translate_id_params {
+	/* The result (output) */
+	int result_id;
+	/* The proc data of the process (output) */
+	struct proc_data *pd;
+
+	/* The namespace to be translated from */
+	uint64_t from_ns;
+	/* The id to be translated */
+	int from_id;
+	/* The type of the id */
+	enum pid_type type;
+};
+
+/**
+ * Translates an id to our namespace, given the proc_pid of the process,
+ * by reading files in /proc.
+ *
+ * @param tip      The parameters
+ * @param proc_pid The proc pid of the process.
+ *                 If 0, use the cached values in tip->pd.
+ */
+static void
+translate_id_proc_pid(struct translate_id_params *tip, int proc_pid)
+{
+	struct proc_data *pd = proc_pid ?
+		get_or_create_proc_data(proc_pid) :
+		tip->pd;
+
+	tip->result_id = 0;
+	tip->pd = NULL;
+
+	if (!pd)
+		return;
+
+	if (proc_pid && !update_proc_data(pd, tip->type))
+		return;
+
+	if (!pd->ns_count || (pd->id_count[tip->type] < pd->ns_count))
+		return;
+
+	int our_ns_id_idx = pd->id_count[tip->type] - pd->ns_count;
+
+	for (int i = 0; i < pd->ns_count; i++) {
+		if (pd->ns_hierarchy[i] != tip->from_ns)
+			continue;
+
+		int id_idx = pd->id_count[tip->type] - i - 1;
+		if (pd->id_hierarchy[tip->type][id_idx] != tip->from_id)
+			return;
+
+		tip->result_id = pd->id_hierarchy[tip->type][our_ns_id_idx];
+		tip->pd = pd;
+		return;
+	}
+}
+
+/**
+ * Translates an id to our namespace, by reading all proc entries in dir.
+ *
+ * @param tip            The parameters
+ * @param path           The path of the dir to be read.
+ * @param read_task_dir  Whether recurse to "task" subdirectory.
+ */
+static void
+translate_id_dir(struct translate_id_params *tip, const char *path,
+                 bool read_task_dir)
+{
+	DIR *dir = opendir(path);
+	if (!dir) {
+		debug_func_perror_msg("opening dir: %s", path);
+		return;
+	}
+
+	while (!tip->result_id) {
+		errno = 0;
+		struct_dirent *entry = read_dir(dir);
+		if (!entry) {
+			if (errno)
+				perror_func_msg("readdir");
+
+			break;
+		}
+
+		if (entry->d_type != DT_DIR)
+			continue;
+
+		errno = 0;
+		long proc_pid = strtol(entry->d_name, NULL, 10);
+		if (errno)
+			continue;
+		if ((proc_pid < 1) || (proc_pid > INT_MAX))
+			continue;
+
+		if (read_task_dir) {
+			char task_dir_path[PATH_MAX + 1];
+			xsprintf(task_dir_path, "/proc/%ld/task", proc_pid);
+			translate_id_dir(tip, task_dir_path, false);
+		}
+
+		if (tip->result_id)
+			break;
+
+		translate_id_proc_pid(tip, proc_pid);
+	}
+
+	closedir(dir);
+}
+
+/**
+ * Iterator function of the proc_data_cache for id translation.
+ * If the cache contains the id we are looking for, reads the corresponding
+ * directory in /proc, and if cache is valid, saves the result.
+ */
+static void
+proc_data_cache_iterator_fn(void* fn_data, uint64_t key, uint64_t val)
+{
+	struct translate_id_params *tip = (struct translate_id_params *)fn_data;
+	struct proc_data *pd = (struct proc_data *) (uintptr_t) val;
+
+	if (!pd)
+		return;
+
+	/* Result already found in an earlier iteration */
+	if (tip->result_id)
+		return;
+
+	/* Translate from cache */
+	tip->pd = pd;
+	translate_id_proc_pid(tip, 0);
+	if (!tip->result_id)
+		return;
+
+	/* Now translate from actual data in /proc, to check cache validity */
+	translate_id_proc_pid(tip, pd->proc_pid);
+}
+
+int
+translate_pid(struct tcb *tcp, int from_id, enum pid_type type,
+              int *proc_pid_ptr)
+{
+	if ((from_id <= 0) || (type < 0) || (type >= PT_COUNT))
+		return 0;
+
+	const uint64_t our_ns = get_our_ns();
+	if (!our_ns)
+		return 0;
+
+	struct translate_id_params tip = {
+		.result_id = 0,
+		.pd = NULL,
+		.from_ns = tcp ? get_ns(tcp) : our_ns,
+		.from_id = from_id,
+		.type = type,
+	};
+
+	if (!tip.from_ns)
+		return 0;
+
+	/* If translation is trivial */
+	if (tip.from_ns == our_ns && (is_proc_ours() || !proc_pid_ptr)) {
+		if (proc_pid_ptr)
+			*proc_pid_ptr = from_id;
+
+		tip.result_id = tip.from_id;
+		goto exit;
+	}
+
+	if (ns_get_parent_enotty)
+		return 0;
+
+	/* Look for a cached proc_pid for this (from_ns, from_id) pair */
+	int cached_proc_pid = get_cached_proc_pid(tip.from_ns, tip.from_id,
+		tip.type);
+	if (cached_proc_pid) {
+		translate_id_proc_pid(&tip, cached_proc_pid);
+		if (tip.result_id)
+			goto exit;
+	}
+
+	/* Iterate through the cache, find potential proc_data */
+	trie_iterate_keys(proc_data_cache, 0, pid_max,
+		proc_data_cache_iterator_fn, &tip);
+	/* (proc_data_cache_iterator_fn takes care about updating proc_data) */
+	if (tip.result_id)
+		goto exit;
+
+	/* No cache helped, read all entries in /proc */
+	translate_id_dir(&tip, "/proc", true);
+
+exit:
+	if (tip.pd) {
+		if (tip.pd->proc_pid)
+			put_proc_pid(tip.from_ns, tip.from_id, tip.type,
+				tip.pd->proc_pid);
+
+		if (proc_pid_ptr)
+			*proc_pid_ptr = tip.pd->proc_pid;
+	}
+
+	return tip.result_id;
+}
+
+int
+get_proc_pid(struct tcb *tcp)
+{
+	if (!is_proc_ours()) {
+		int ret = 0;
+		translate_pid(NULL, tcp->pid, PT_TID, &ret);
+		return ret;
+	}
+
+	return tcp->pid;
+}
+
+static void
+printpid_translation(struct tcb *tcp, int pid, enum pid_type type)
+{
+	if (!pidns_translation)
+		return;
+
+	int strace_pid = translate_pid(tcp, pid, type, NULL);
+	if (strace_pid && strace_pid != pid)
+		tprintf_comment("%d in strace's PID NS", strace_pid);
+}
+
+void
+printpid(struct tcb *tcp, int pid, enum pid_type type)
+{
+	tprintf("%d", pid);
+	printpid_translation(tcp, pid, type);
+}
+
+void
+printpid_tgid_pgid(struct tcb *tcp, int pid)
+{
+	tprintf("%d", pid);
+	if (pid > 0)
+		printpid_translation(tcp,  pid, PT_TGID);
+	else if (pid < -1)
+		printpid_translation(tcp, -pid, PT_PGID);
+}
diff --git a/strace.1.in b/strace.1.in
index 3b21caec..adca194c 100644
--- a/strace.1.in
+++ b/strace.1.in
@@ -1075,6 +1075,10 @@ Print all available information associated with file descritors:
 protocol-specific information associated with socket file descriptors,
 block/character device number associated with device file descriptors,
 and PIDs asociated with pidfd file descriptors.
+.TP
+.B \-\-pidns\-translation
+If strace and tracee are in different PID namespaces, print PIDs in
+strace's namespace also.
 .SS Statistics
 .TP 12
 .B \-c
diff --git a/strace.c b/strace.c
index 4c96a98b..249533ea 100644
--- a/strace.c
+++ b/strace.c
@@ -133,6 +133,8 @@ static unsigned int daemonized_tracer;
 static int post_attach_sigstop = TCB_IGNORE_ONE_SIGSTOP;
 #define use_seize (post_attach_sigstop == 0)
 
+unsigned int pidns_translation;
+
 static bool detach_on_execve;
 
 static int exit_code;
@@ -1998,6 +2000,8 @@ init(int argc, char *argv[])
 
 	os_release = get_os_release();
 
+	pidns_init();
+
 	shared_log = stderr;
 	set_sortby(DEFAULT_SORTBY);
 	set_personality(DEFAULT_PERSONALITY);
@@ -2022,6 +2026,7 @@ init(int argc, char *argv[])
 		GETOPT_FOLLOWFORKS,
 		GETOPT_OUTPUT_SEPARATELY,
 		GETOPT_TS,
+		GETOPT_PIDNS_TRANSLATION,
 
 		GETOPT_QUAL_TRACE,
 		GETOPT_QUAL_ABBREV,
@@ -2072,6 +2077,7 @@ init(int argc, char *argv[])
 		{ "summary-wall-clock", no_argument,	   0, 'w' },
 		{ "strings-in-hex",	optional_argument, 0, GETOPT_HEX_STR },
 		{ "const-print-style",	required_argument, 0, 'X' },
+		{ "pidns-translation",	no_argument      , 0, GETOPT_PIDNS_TRANSLATION },
 		{ "successful-only",	no_argument,	   0, 'z' },
 		{ "failed-only",	no_argument,	   0, 'Z' },
 		{ "failing-only",	no_argument,	   0, 'Z' },
@@ -2285,6 +2291,9 @@ init(int argc, char *argv[])
 		case 'y':
 			yflag_short++;
 			break;
+		case GETOPT_PIDNS_TRANSLATION:
+			pidns_translation++;
+			break;
 		case 'z':
 			clear_number_set_array(status_set, 1);
 			add_number_to_set(STATUS_SUCCESSFUL, status_set);
diff --git a/syscall.c b/syscall.c
index bcc87025..0f4bab6d 100644
--- a/syscall.c
+++ b/syscall.c
@@ -937,6 +937,21 @@ syscall_exiting_trace(struct tcb *tcp, struct timespec *ts, int res)
 					tprintf("= %" PRI_kld, tcp->u_rval);
 				}
 				break;
+			case RVAL_TID:
+			case RVAL_SID:
+			case RVAL_TGID:
+			case RVAL_PGID: {
+				#define _(_t) [RVAL_##_t - RVAL_TID] = PT_##_t
+				static const enum pid_type types[] = {
+					_(TID), _(SID), _(TGID), _(PGID),
+				};
+				#undef _
+
+				tprints("= ");
+				printpid(tcp, tcp->u_rval,
+					 types[(sys_res & RVAL_MASK) - RVAL_TID]);
+				break;
+			}
 			default:
 				error_msg("invalid rval format");
 				break;
diff --git a/trie.c b/trie.c
new file mode 100644
index 00000000..76cecc25
--- /dev/null
+++ b/trie.c
@@ -0,0 +1,250 @@
+/*
+ * Simple trie implementation for key-value mapping storage
+ *
+ * Copyright (c) 2020 ?kos Uzonyi <uzonyi.akos at gmail.com>
+ * All rights reserved.
+ *
+ * SPDX-License-Identifier: LGPL-2.1-or-later
+ */
+
+#include "defs.h"
+
+#include <assert.h>
+#include <stdbool.h>
+#include <stdint.h>
+#include <stdlib.h>
+
+#include "trie.h"
+
+static const uint8_t ptr_sz_lg = (sizeof(uint64_t *) == 8 ? 6 : 5);
+
+/**
+ * Returns lg2 of node size for the specific level of the trie. If max_depth
+ * provided is less than zero, it is calculated via trie_get_depth call.
+ */
+static uint8_t
+trie_get_node_size(struct trie *t, uint8_t depth)
+{
+	/* Last level contains data and we allow it having a different size */
+	if (depth == t->max_depth)
+		return t->data_block_key_bits + t->item_size_lg;
+	/* Last level of the tree can be smaller */
+	if (depth == t->max_depth - 1)
+		return (t->key_size - t->data_block_key_bits - 1) %
+		t->node_key_bits + 1 + ptr_sz_lg;
+
+	return t->node_key_bits + ptr_sz_lg;
+}
+
+/**
+ * Provides starting offset of bits in key corresponding to the node index
+ * at the specific level.
+ */
+static uint8_t
+trie_get_node_bit_offs(struct trie *t, uint8_t depth)
+{
+	uint8_t offs;
+
+	if (depth == t->max_depth)
+		return 0;
+
+	offs = t->data_block_key_bits;
+
+	if (depth == t->max_depth - 1)
+		return offs;
+
+	/* data_block_size + remainder */
+	offs += trie_get_node_size(t, t->max_depth - 1) - ptr_sz_lg;
+	offs += (t->max_depth - depth - 2) * t->node_key_bits;
+
+	return offs;
+}
+
+struct trie *
+trie_create(uint8_t key_size, uint8_t item_size_lg, uint8_t node_key_bits,
+            uint8_t data_block_key_bits, uint64_t empty_value)
+{
+	if (item_size_lg > 6)
+		return NULL;
+	if (key_size > 64)
+		return NULL;
+	if (node_key_bits < 1)
+		return NULL;
+	if (data_block_key_bits < 1 || data_block_key_bits > key_size)
+		return NULL;
+
+	struct trie *t = malloc(sizeof(*t));
+	if (!t)
+		return NULL;
+
+	t->empty_value = empty_value;
+	t->data = NULL;
+	t->item_size_lg = item_size_lg;
+	t->node_key_bits = node_key_bits;
+	t->data_block_key_bits = data_block_key_bits;
+	t->key_size = key_size;
+	t->max_depth = (key_size - data_block_key_bits + node_key_bits - 1)
+		/ t->node_key_bits;
+
+	return t;
+}
+
+static uint64_t *
+trie_get_node(struct trie *t, uint64_t key, bool auto_create)
+{
+	void **cur_node = &(t->data);
+
+	if (t->key_size < 64 && key > (uint64_t) 1 << t->key_size)
+		return NULL;
+
+	for (uint8_t cur_depth = 0; cur_depth <= t->max_depth; cur_depth++) {
+		uint8_t offs = trie_get_node_bit_offs(t, cur_depth);
+		uint8_t sz = trie_get_node_size(t, cur_depth);
+
+		if (!*cur_node) {
+			if (!auto_create)
+				return NULL;
+
+			*cur_node = xcalloc(1 << sz, 1);
+		}
+
+		if (cur_depth >= t->max_depth)
+			break;
+
+		size_t pos = (key >> offs) & ((1 << (sz - ptr_sz_lg)) - 1);
+		cur_node = (((void **) (*cur_node)) + pos);
+	}
+
+	return (uint64_t *) (*cur_node);
+}
+
+static void
+trie_data_block_calc_pos(struct trie *t, uint64_t key,
+                         uint64_t *pos, uint64_t *mask, uint64_t *offs)
+{
+	uint64_t key_mask;
+
+	key_mask = (1 << t->data_block_key_bits) - 1;
+	*pos = (key & key_mask) >> (6 - t->item_size_lg);
+
+	key_mask = (1 << (6 - t->item_size_lg)) - 1;
+	*offs = (key & key_mask) * (1 << t->item_size_lg);
+
+	*mask = (((uint64_t) 1 << (1 << t->item_size_lg)) - 1) << *offs;
+}
+
+bool
+trie_set(struct trie *t, uint64_t key, uint64_t val)
+{
+	uint64_t *data = trie_get_node(t, key, true);
+	if (!data)
+		return false;
+
+	uint64_t pos, mask, offs;
+	trie_data_block_calc_pos(t, key, &pos, &mask, &offs);
+
+	data[pos] &= ~mask;
+	data[pos] |= (val << offs) & mask;
+
+	return true;
+}
+
+static uint64_t
+trie_data_block_get(struct trie *t, uint64_t *data, uint64_t key)
+{
+	if (!data)
+		return t->empty_value;
+
+	uint64_t pos, mask, offs;
+	trie_data_block_calc_pos(t, key, &pos, &mask, &offs);
+
+	return (data[pos] & mask) >> offs;
+}
+
+uint64_t
+trie_get(struct trie *b, uint64_t key)
+{
+	return trie_data_block_get(b, trie_get_node(b, key, false), key);
+}
+
+static uint64_t
+trie_iterate_keys_node(struct trie *t,
+                       trie_iterate_fn fn, void *fn_data,
+                       void *node, uint64_t start, uint64_t end,
+                       uint8_t depth)
+{
+	if (start > end || !node)
+		return 0;
+
+	if (depth == t->max_depth) {
+		for (uint64_t i = start; i <= end; i++)
+			fn(fn_data, i, trie_data_block_get(t,
+				(uint64_t *) node, i));
+
+		return end - start + 1; //TODO: overflow
+	}
+
+	uint8_t parent_node_bit_off = depth == 0 ?
+		t->key_size :
+		trie_get_node_bit_offs(t, depth - 1);
+
+	uint64_t first_key_in_node = start &
+		(uint64_t) -1 << parent_node_bit_off;
+
+	uint8_t node_bit_off = trie_get_node_bit_offs(t, depth);
+	uint8_t node_key_bits = parent_node_bit_off - node_bit_off;
+	uint64_t mask = ((uint64_t) 1 << (node_key_bits)) - 1;
+	uint64_t start_index = (start >> node_bit_off) & mask;
+	uint64_t end_index = (end >> node_bit_off) & mask;
+	uint64_t child_key_count = (uint64_t) 1 << node_bit_off;
+
+	uint64_t count = 0;
+
+	for (uint64_t i = start_index; i <= end_index; i++) {
+		uint64_t child_start = first_key_in_node + i * child_key_count;
+		uint64_t child_end = first_key_in_node +
+			(i + 1) * child_key_count - 1;
+
+		if (child_start < start)
+			child_start = start;
+		if (child_end > end)
+			child_end = end;
+
+		count += trie_iterate_keys_node(t, fn, fn_data,
+			((void **) node)[i], child_start, child_end,
+			depth + 1);
+	}
+
+	return count;
+}
+
+uint64_t trie_iterate_keys(struct trie *t, uint64_t start, uint64_t end,
+                           trie_iterate_fn fn, void *fn_data)
+{
+	return trie_iterate_keys_node(t, fn, fn_data, t->data,
+		start, end, 0);
+}
+
+static void
+trie_free_node(struct trie *t, void *node, uint8_t depth)
+{
+	if (!node)
+		return;
+
+	if (depth >= t->max_depth)
+		goto free_node;
+
+	size_t sz = 1 << (trie_get_node_size(t, depth) - ptr_sz_lg);
+	for (size_t i = 0; i < sz; i++)
+		trie_free_node(t, ((void **) node)[i], depth + 1);
+
+free_node:
+	free(node);
+}
+
+void
+trie_free(struct trie *t)
+{
+	trie_free_node(t, t->data, 0);
+	free(t);
+}
diff --git a/trie.h b/trie.h
new file mode 100644
index 00000000..f7058c7e
--- /dev/null
+++ b/trie.h
@@ -0,0 +1,89 @@
+/*
+ * Simple trie interface
+ *
+ * Copyright (c) 2020 ?kos Uzonyi <uzonyi.akos at gmail.com>
+ * All rights reserved.
+ *
+ * SPDX-License-Identifier: LGPL-2.1-or-later
+ */
+
+#ifndef STRACE_TRIE_H
+#define STRACE_TRIE_H
+
+/**
+ * Trie control structure.
+ * Trie implemented here has the following properties:
+ *  * It allows storing values of the same size, the size can vary from 1 bit to
+ *    64 bit values (only power of 2 sizes are allowed).
+ *  * The key can be up to 64 bits in size.
+ *  * It has separate configuration for node size and data block size.
+ *
+ * How bits of key are used for different node levels:
+ *
+ *   highest bits                                                  lowest bits
+ *  | node_key_bits | node_key_bits | ... | <remainder> | data_block_key_bits |
+ *  \_________________________________________________________________________/
+ *                                 key_size
+ *
+ * So, the remainder is used on the lowest non-data node level.
+ *
+ * As of now, it doesn't implement any mechanisms for resizing/changing key
+ * size.  De-fragmentation is also unsupported currently.
+ */
+struct trie {
+	/** Return value of trie_get if key is not found */
+	uint64_t empty_value;
+
+	/** Pointer to root node */
+	void *data;
+
+	/** Key size in bits (0..64). */
+	uint8_t key_size;
+
+	/**
+	 * Size of the stored values in log2 bits (0..6).
+	 * (6: 64 bit values, 5: 32 bit values, ...)
+	 */
+	uint8_t item_size_lg;
+
+	/**
+	 * Number of bits in key that makes a symbol for a node.
+	 * (equals to log2 of the child count of the node)
+	 */
+	uint8_t node_key_bits;
+
+	/**
+	 * Number of bits in key that make a symbol for the data block (leaf).
+	 * (equals to log2 of the value count stored in a data block)
+	 */
+	uint8_t data_block_key_bits;
+
+	/** The depth of the data block. Caluclated from the values above */
+	uint8_t max_depth;
+};
+
+struct trie* trie_create(uint8_t key_size, uint8_t item_size_lg,
+			uint8_t node_key_bits, uint8_t data_block_key_bits,
+			uint64_t empty_value);
+
+bool trie_set(struct trie *t, uint64_t key, uint64_t val);
+uint64_t trie_get(struct trie *t, uint64_t key);
+
+typedef void (*trie_iterate_fn)(void *data, uint64_t key, uint64_t val);
+
+/**
+ * Calls trie_iterate_fn for each key-value pair where
+ * key is inside the [start, end] interval (inclusive).
+ *
+ * @param t        The trie.
+ * @param start    The start of the key interval (inclusive).
+ * @param end      The end of the key interval (inclusive).
+ * @param fn       The function to be called.
+ * @param fn_data  The value to be passed to fn.
+ */
+uint64_t trie_iterate_keys(struct trie *t, uint64_t start, uint64_t end,
+			    trie_iterate_fn fn, void *fn_data);
+
+void trie_free(struct trie *t);
+
+#endif /* !STRACE_TRIE_H */
-- 
2.27.0


From uzonyi.akos at gmail.com  Mon Aug  3 19:19:14 2020
From: uzonyi.akos at gmail.com (=?UTF-8?q?=C3=81kos=20Uzonyi?=)
Date: Mon,  3 Aug 2020 21:19:14 +0200
Subject: [PATCH v5 3/5] Use get_proc_pid for /proc paths
In-Reply-To: <20200803191916.94724-1-uzonyi.akos@gmail.com>
References: <20200803191916.94724-1-uzonyi.akos@gmail.com>
Message-ID: <20200803191916.94724-4-uzonyi.akos@gmail.com>

* mmap_cache.c (mmap_cache_rebuild_if_invalid): Use proc pid instead of
tcp->pid for /proc path.
* util.c (getfdproto): Likewise.
(pidfd_get_pid): Likewise.
* pathtrace.c (getfdpath_pid): Likewise.
* strace.c (attach_tcb): Likewise.
---
 mmap_cache.c | 2 +-
 pathtrace.c  | 5 ++++-
 strace.c     | 2 +-
 util.c       | 7 +++++--
 4 files changed, 11 insertions(+), 5 deletions(-)

diff --git a/mmap_cache.c b/mmap_cache.c
index 89c62254..9825df26 100644
--- a/mmap_cache.c
+++ b/mmap_cache.c
@@ -84,7 +84,7 @@ mmap_cache_rebuild_if_invalid(struct tcb *tcp, const char *caller)
 		return MMAP_CACHE_REBUILD_READY;
 
 	char filename[sizeof("/proc/4294967296/maps")];
-	xsprintf(filename, "/proc/%u/maps", tcp->pid);
+	xsprintf(filename, "/proc/%u/maps", get_proc_pid(tcp));
 
 	FILE *fp = fopen_stream(filename, "r");
 	if (!fp) {
diff --git a/pathtrace.c b/pathtrace.c
index 5b60762b..74717a8a 100644
--- a/pathtrace.c
+++ b/pathtrace.c
@@ -87,7 +87,10 @@ getfdpath_pid(pid_t pid, int fd, char *buf, unsigned bufsize)
 	if (fd < 0)
 		return -1;
 
-	xsprintf(linkpath, "/proc/%u/fd/%u", pid, fd);
+	int proc_pid = 0;
+	translate_pid(NULL, pid, PT_TID, &proc_pid);
+
+	xsprintf(linkpath, "/proc/%u/fd/%u", proc_pid, fd);
 	n = readlink(linkpath, buf, bufsize - 1);
 	/*
 	 * NB: if buf is too small, readlink doesn't fail,
diff --git a/strace.c b/strace.c
index 249533ea..ef23f08f 100644
--- a/strace.c
+++ b/strace.c
@@ -1196,7 +1196,7 @@ attach_tcb(struct tcb *const tcp)
 	unsigned int ntid = 0, nerr = 0;
 
 	if (followfork && tcp->pid != strace_child &&
-	    xsprintf(procdir, task_path, tcp->pid) > 0 &&
+	    xsprintf(procdir, task_path, get_proc_pid(tcp)) > 0 &&
 	    (dir = opendir(procdir)) != NULL) {
 		struct_dirent *de;
 
diff --git a/util.c b/util.c
index 094e5818..d87d022e 100644
--- a/util.c
+++ b/util.c
@@ -501,7 +501,7 @@ getfdproto(struct tcb *tcp, int fd)
 	if (fd < 0)
 		return SOCK_PROTO_UNKNOWN;
 
-	xsprintf(path, "/proc/%u/fd/%u", tcp->pid, fd);
+	xsprintf(path, "/proc/%u/fd/%u", get_proc_pid(tcp), fd);
 	r = getxattr(path, "system.sockprotoname", buf, bufsize - 1);
 	if (r <= 0)
 		return SOCK_PROTO_UNKNOWN;
@@ -582,8 +582,11 @@ printdev(struct tcb *tcp, int fd, const char *path)
 pid_t
 pidfd_get_pid(pid_t pid_of_fd, int fd)
 {
+	int proc_pid = 0;
+	translate_pid(NULL, pid_of_fd, PT_TID, &proc_pid);
+
 	char fdi_path[sizeof("/proc/%u/fdinfo/%u") + 2 * sizeof(int) * 3];
-	xsprintf(fdi_path, "/proc/%u/fdinfo/%u", pid_of_fd, fd);
+	xsprintf(fdi_path, "/proc/%u/fdinfo/%u", proc_pid, fd);
 
 	FILE *f = fopen_stream(fdi_path, "r");
 	if (!f)
-- 
2.27.0


From uzonyi.akos at gmail.com  Mon Aug  3 19:19:16 2020
From: uzonyi.akos at gmail.com (=?UTF-8?q?=C3=81kos=20Uzonyi?=)
Date: Mon,  3 Aug 2020 21:19:16 +0200
Subject: [PATCH v5 5/5] Add tests for PID namespace translation
In-Reply-To: <20200803191916.94724-1-uzonyi.akos@gmail.com>
References: <20200803191916.94724-1-uzonyi.akos@gmail.com>
Message-ID: <20200803191916.94724-6-uzonyi.akos@gmail.com>

* tests/.gitignore: Add new test executables.
* tests/Makefile.am (check_PROGRAMS): Add new test executables.
(DECODER_TESTS) Add new test files.
* tests/gen_tests.in: Add new tests.
* tests/fcntl-Y.c: New file.
* tests/fcntl64-Y.c: New file.
* tests/fork-Y.awk: New file.
* tests/fork-Y.c: New file.
* tests/fork-Y.test: New file.
* tests/getpgrp-Y.c: New file.
* tests/getpid-Y.c: New file.
* tests/getsid-Y.c: New file.
* tests/gettid-Y.c: New file.
* tests/ioctl_block-Y.c: New file.
* tests/ioctl_block-Y.test: New file.
* tests/ioprio-Y.c: New file.
* tests/kill-Y.c: New file.
* tests/migrate_pages-Y.c: New file.
* tests/move_pages-Y.c: New file.
* tests/net-sockaddr-Y.c: New file.
* tests/netlink_audit-Y.c: New file.
* tests/netlink_audit-Y.test: New file.
* tests/pidfd_open-Y.c: New file.
* tests/pidfd_send_signal-Y.c: New file.
* tests/prlimit64-Y.c: New file.
* tests/process_vm_readv-Y.c: New file.
* tests/process_vm_writev-Y.c: New file.
* tests/rt_sigqueueinfo-Y.c: New file.
* tests/rt_tgsigqueueinfo-Y.c: New file.
* tests/sched_xetaffinity-Y.c: New file.
* tests/sched_xetattr-Y.c: New file.
* tests/sched_xetparam-Y.c: New file.
* tests/sched_xetscheduler-Y.c: New file.
* tests/signal_receive-Y.c: New file.
* tests/so_peercred-Y.c: New file.
* tests/xet_robust_list-Y.c: New file.
* tests/xetpgid-Y.c: New file.
* tests/xetpriority-Y.c: New file.
* tests/fcntl-common.c: Print PID translation string after PIDs.
* tests/fcntl.c: Likewise.
* tests/fcntl64.c: Likewise.
* tests/getpgrp.c: Likewise.
* tests/getpid.c: Likewise.
* tests/getsid.c: Likewise.
* tests/gettid.c: Likewise.
* tests/ioctl_block.c: Likewise.
* tests/ioprio.c: Likewise.
* tests/kcmp.c: Likewise.
* tests/kill.c: Likewise.
* tests/migrate_pages.c: Likewise.
* tests/move_pages.c: Likewise.
* tests/net-sockaddr.c: Likewise.
* tests/netlink_audit.c: Likewise.
* tests/pidfd_open.c: Likewise.
* tests/pidfd_send_signal.c: Likewise.
* tests/prlimit64.c: Likewise.
* tests/process_vm_readv_writev.c: Likewise.
* tests/rt_sigqueueinfo.c: Likewise.
* tests/rt_tgsigqueueinfo.c: Likewise.
* tests/sched_xetaffinity.c: Likewise.
* tests/sched_xetattr.c: Likewise.
* tests/sched_xetparam.c: Likewise.
* tests/sched_xetscheduler.c: Likewise.
* tests/signal_receive.c: Likewise.
* tests/so_peercred.c: Likewise.
* tests/xet_robust_list.c: Likewise.
* tests/xetpgid.c: Likewise.
* tests/xetpriority.c: Likewise.
---
 tests/.gitignore                              | 31 +++++++
 tests/Makefile.am                             | 35 ++++++++
 tests/fcntl--pidns-translation.c              |  2 +
 tests/fcntl-common.c                          | 82 ++++++++++++++-----
 tests/fcntl.c                                 |  1 +
 tests/fcntl64--pidns-translation.c            |  2 +
 tests/fcntl64.c                               |  3 +
 tests/fork--pidns-translation.awk             | 15 ++++
 tests/fork--pidns-translation.c               | 69 ++++++++++++++++
 tests/fork--pidns-translation.test            | 16 ++++
 tests/gen_tests.in                            | 30 ++++++-
 tests/getpgrp--pidns-translation.c            |  2 +
 tests/getpgrp.c                               |  8 +-
 tests/getpid--pidns-translation.c             |  2 +
 tests/getpid.c                                |  8 +-
 tests/getsid--pidns-translation.c             |  2 +
 tests/getsid.c                                |  9 +-
 tests/gettid--pidns-translation.c             |  2 +
 tests/gettid.c                                |  8 +-
 tests/ioctl_block--pidns-translation.c        |  2 +
 tests/ioctl_block--pidns-translation.test     | 24 ++++++
 tests/ioctl_block.c                           | 24 +++++-
 tests/ioprio--pidns-translation.c             |  2 +
 tests/ioprio.c                                | 54 ++++++++----
 tests/kcmp-y--pidns-translation.c             |  2 +
 tests/kcmp.c                                  | 11 ++-
 tests/kill--pidns-translation.c               |  2 +
 tests/kill.c                                  | 12 ++-
 tests/migrate_pages--pidns-translation.c      |  2 +
 tests/migrate_pages.c                         | 17 +++-
 tests/move_pages--pidns-translation.c         |  2 +
 tests/move_pages.c                            | 51 +++++++-----
 tests/net-sockaddr--pidns-translation.c       |  2 +
 tests/net-sockaddr.c                          | 66 +++++++++++++--
 tests/netlink_audit--pidns-translation.c      |  2 +
 tests/netlink_audit--pidns-translation.test   | 13 +++
 tests/netlink_audit.c                         | 11 ++-
 tests/pidfd_open--pidns-translation.c         |  2 +
 tests/pidfd_open.c                            | 21 +++--
 tests/pidfd_send_signal--pidns-translation.c  |  2 +
 tests/pidfd_send_signal.c                     | 13 ++-
 tests/prlimit64--pidns-translation.c          |  2 +
 tests/prlimit64.c                             | 17 +++-
 tests/process_vm_readv--pidns-translation.c   |  2 +
 tests/process_vm_readv_writev.c               | 27 +++---
 tests/process_vm_writev--pidns-translation.c  |  2 +
 tests/rt_sigqueueinfo--pidns-translation.c    |  2 +
 tests/rt_sigqueueinfo.c                       | 15 +++-
 tests/rt_tgsigqueueinfo--pidns-translation.c  |  2 +
 tests/rt_tgsigqueueinfo.c                     | 26 ++++--
 tests/sched_xetaffinity--pidns-translation.c  |  2 +
 tests/sched_xetaffinity.c                     | 31 ++++---
 tests/sched_xetattr--pidns-translation.c      |  2 +
 tests/sched_xetattr.c                         | 47 ++++++++++-
 tests/sched_xetparam--pidns-translation.c     |  2 +
 tests/sched_xetparam.c                        | 20 +++--
 tests/sched_xetscheduler--pidns-translation.c |  2 +
 tests/sched_xetscheduler.c                    | 44 ++++++----
 tests/signal_receive--pidns-translation.c     |  2 +
 tests/signal_receive.c                        | 22 +++--
 tests/so_peercred--pidns-translation.c        |  2 +
 tests/so_peercred.c                           | 22 +++++
 tests/xet_robust_list--pidns-translation.c    |  2 +
 tests/xet_robust_list.c                       | 18 +++-
 tests/xetpgid--pidns-translation.c            |  2 +
 tests/xetpgid.c                               | 21 +++--
 tests/xetpriority--pidns-translation.c        |  2 +
 tests/xetpriority.c                           | 20 ++++-
 68 files changed, 854 insertions(+), 168 deletions(-)
 create mode 100644 tests/fcntl--pidns-translation.c
 create mode 100644 tests/fcntl64--pidns-translation.c
 create mode 100644 tests/fork--pidns-translation.awk
 create mode 100644 tests/fork--pidns-translation.c
 create mode 100755 tests/fork--pidns-translation.test
 create mode 100644 tests/getpgrp--pidns-translation.c
 create mode 100644 tests/getpid--pidns-translation.c
 create mode 100644 tests/getsid--pidns-translation.c
 create mode 100644 tests/gettid--pidns-translation.c
 create mode 100644 tests/ioctl_block--pidns-translation.c
 create mode 100755 tests/ioctl_block--pidns-translation.test
 create mode 100644 tests/ioprio--pidns-translation.c
 create mode 100644 tests/kcmp-y--pidns-translation.c
 create mode 100644 tests/kill--pidns-translation.c
 create mode 100644 tests/migrate_pages--pidns-translation.c
 create mode 100644 tests/move_pages--pidns-translation.c
 create mode 100644 tests/net-sockaddr--pidns-translation.c
 create mode 100644 tests/netlink_audit--pidns-translation.c
 create mode 100755 tests/netlink_audit--pidns-translation.test
 create mode 100644 tests/pidfd_open--pidns-translation.c
 create mode 100644 tests/pidfd_send_signal--pidns-translation.c
 create mode 100644 tests/prlimit64--pidns-translation.c
 create mode 100644 tests/process_vm_readv--pidns-translation.c
 create mode 100644 tests/process_vm_writev--pidns-translation.c
 create mode 100644 tests/rt_sigqueueinfo--pidns-translation.c
 create mode 100644 tests/rt_tgsigqueueinfo--pidns-translation.c
 create mode 100644 tests/sched_xetaffinity--pidns-translation.c
 create mode 100644 tests/sched_xetattr--pidns-translation.c
 create mode 100644 tests/sched_xetparam--pidns-translation.c
 create mode 100644 tests/sched_xetscheduler--pidns-translation.c
 create mode 100644 tests/signal_receive--pidns-translation.c
 create mode 100644 tests/so_peercred--pidns-translation.c
 create mode 100644 tests/xet_robust_list--pidns-translation.c
 create mode 100644 tests/xetpgid--pidns-translation.c
 create mode 100644 tests/xetpriority--pidns-translation.c

diff --git a/tests/.gitignore b/tests/.gitignore
index 0031d04d..4d1153fc 100644
--- a/tests/.gitignore
+++ b/tests/.gitignore
@@ -116,7 +116,9 @@ fchown
 fchown32
 fchownat
 fcntl
+fcntl--pidns-translation
 fcntl64
+fcntl64--pidns-translation
 fdatasync
 fflush
 file_handle
@@ -126,6 +128,7 @@ filter-unavailable
 finit_module
 flock
 fork-f
+fork--pidns-translation
 fsconfig
 fsconfig-P
 fsmount
@@ -168,7 +171,9 @@ getgroups
 getgroups32
 getpeername
 getpgrp
+getpgrp--pidns-translation
 getpid
+getpid--pidns-translation
 getppid
 getrandom
 getresgid
@@ -178,8 +183,10 @@ getresuid32
 getrlimit
 getrusage
 getsid
+getsid--pidns-translation
 getsockname
 gettid
+gettid--pidns-translation
 getuid
 getuid32
 getxgid
@@ -200,6 +207,7 @@ io_uring_register
 io_uring_setup
 ioctl
 ioctl_block
+ioctl_block--pidns-translation
 ioctl_dm
 ioctl_dm-v
 ioctl_evdev
@@ -275,6 +283,7 @@ ioctl_watchdog
 ioperm
 iopl
 ioprio
+ioprio--pidns-translation
 ioprio-Xabbrev
 ioprio-Xraw
 ioprio-Xverbose
@@ -299,6 +308,7 @@ ipc_shm-Xverbose
 is_linux_mips_n64
 kcmp
 kcmp-y
+kcmp-y--pidns-translation
 kern_features
 kernel_version
 kernel_version-Xabbrev
@@ -311,6 +321,7 @@ keyctl-Xabbrev
 keyctl-Xraw
 keyctl-Xverbose
 kill
+kill--pidns-translation
 kill_child
 ksysent
 ksysent.h
@@ -340,6 +351,7 @@ memfd_create-Xabbrev
 memfd_create-Xraw
 memfd_create-Xverbose
 migrate_pages
+migrate_pages--pidns-translation
 mincore
 mkdir
 mkdirat
@@ -371,6 +383,7 @@ move_pages
 move_pages-Xabbrev
 move_pages-Xraw
 move_pages-Xverbose
+move_pages--pidns-translation
 mq
 mq_sendrecv
 mq_sendrecv-read
@@ -391,6 +404,7 @@ net-packet_mreq-Xabbrev
 net-packet_mreq-Xraw
 net-packet_mreq-Xverbose
 net-sockaddr
+net-sockaddr--pidns-translation
 net-tpacket_req
 net-tpacket_stats
 net-tpacket_stats-success
@@ -400,6 +414,7 @@ net-yy-inet6
 net-yy-netlink
 net-yy-unix
 netlink_audit
+netlink_audit--pidns-translation
 netlink_crypto
 netlink_generic
 netlink_inet_diag
@@ -507,7 +522,9 @@ pidfd_open--decode-fd-socket
 pidfd_open-P
 pidfd_open-y
 pidfd_open-yy
+pidfd_open--pidns-translation
 pidfd_send_signal
+pidfd_send_signal--pidns-translation
 pipe
 pipe2
 pkey_alloc
@@ -546,8 +563,11 @@ printstrn-umoven
 printstrn-umoven-peekdata
 printstrn-umoven-undumpable
 prlimit64
+prlimit64--pidns-translation
 process_vm_readv
+process_vm_readv--pidns-translation
 process_vm_writev
+process_vm_writev--pidns-translation
 pselect6
 ptrace
 ptrace_syscall_info
@@ -597,10 +617,12 @@ rt_sigaction
 rt_sigpending
 rt_sigprocmask
 rt_sigqueueinfo
+rt_sigqueueinfo--pidns-translation
 rt_sigreturn
 rt_sigsuspend
 rt_sigtimedwait
 rt_tgsigqueueinfo
+rt_tgsigqueueinfo--pidns-translation
 run_expect_termsig
 s390_guarded_storage
 s390_guarded_storage-v
@@ -611,9 +633,13 @@ s390_sthyi-v
 sched_get_priority_mxx
 sched_rr_get_interval
 sched_xetaffinity
+sched_xetaffinity--pidns-translation
 sched_xetattr
+sched_xetattr--pidns-translation
 sched_xetparam
+sched_xetparam--pidns-translation
 sched_xetscheduler
+sched_xetscheduler--pidns-translation
 sched_yield
 scm_rights
 scno.h
@@ -669,6 +695,7 @@ sigaltstack
 siginfo
 signal
 signal_receive
+signal_receive--pidns-translation
 signalfd4
 sigpending
 sigprocmask
@@ -681,6 +708,7 @@ so_peercred
 so_peercred-Xabbrev
 so_peercred-Xraw
 so_peercred-Xverbose
+so_peercred--pidns-translation
 sock_filter-v
 sock_filter-v-Xabbrev
 sock_filter-v-Xraw
@@ -783,9 +811,12 @@ waitpid
 xattr
 xattr-strings
 xet_robust_list
+xet_robust_list--pidns-translation
 xet_thread_area_x86
 xetitimer
 xetpgid
+xetpgid--pidns-translation
 xetpriority
+xetpriority--pidns-translation
 xettimeofday
 zeroargc
diff --git a/tests/Makefile.am b/tests/Makefile.am
index 7a583a3a..05e350bd 100644
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@@ -109,17 +109,25 @@ check_PROGRAMS = $(PURE_EXECUTABLES) \
 	delay \
 	execve-v \
 	execveat-v \
+	fcntl--pidns-translation \
+	fcntl64--pidns-translation \
 	filter_seccomp-flag \
 	filter_seccomp-perf \
 	filter-unavailable \
 	fork-f \
+	fork--pidns-translation \
 	fsync-y \
 	get_process_reaper \
+	getpgrp--pidns-translation	\
 	getpid	\
+	getpid--pidns-translation	\
 	getppid	\
+	getsid--pidns-translation \
 	gettid \
+	gettid--pidns-translation \
 	inject-nf \
 	int_0x80 \
+	ioctl_block--pidns-translation \
 	ioctl_dm-v \
 	ioctl_evdev-success \
 	ioctl_evdev-success-Xabbrev \
@@ -150,18 +158,25 @@ check_PROGRAMS = $(PURE_EXECUTABLES) \
 	ioctl_v4l2-success-v-Xabbrev \
 	ioctl_v4l2-success-v-Xraw \
 	ioctl_v4l2-success-v-Xverbose \
+	ioprio--pidns-translation \
 	is_linux_mips_n64 \
+	kcmp-y--pidns-translation \
 	kill_child \
+	kill--pidns-translation \
 	ksysent \
 	list_sigaction_signum \
 	localtime \
 	looping_threads \
+	migrate_pages--pidns-translation \
 	mmsg-silent \
 	mmsg_name-v \
+	move_pages--pidns-translation \
 	msg_control-v \
 	net-accept-connect \
+	net-sockaddr--pidns-translation \
 	net-tpacket_stats-success \
 	nlattr_ifla_xdp-y \
+	netlink_audit--pidns-translation \
 	netlink_inet_diag \
 	netlink_netlink_diag \
 	netlink_unix_diag \
@@ -173,14 +188,19 @@ check_PROGRAMS = $(PURE_EXECUTABLES) \
 	pc \
 	perf_event_open_nonverbose \
 	perf_event_open_unabbrev \
+	pidfd_open--pidns-translation \
+	pidfd_send_signal--pidns-translation \
 	poll-P \
 	ppoll-P \
 	ppoll-v \
+	prlimit64--pidns-translation \
 	prctl-seccomp-filter-v \
 	prctl-seccomp-strict \
 	prctl-spec-inject \
 	print_maxfd \
 	print_ppid_tracerpid \
+	process_vm_readv--pidns-translation \
+	process_vm_writev--pidns-translation \
 	qual_fault \
 	qual_inject-error-signal \
 	qual_inject-retval \
@@ -194,7 +214,13 @@ check_PROGRAMS = $(PURE_EXECUTABLES) \
 	quotactl-xfs-v \
 	redirect-fds \
 	restart_syscall \
+	rt_sigqueueinfo--pidns-translation \
+	rt_tgsigqueueinfo--pidns-translation \
 	run_expect_termsig \
+	sched_xetaffinity--pidns-translation \
+	sched_xetattr--pidns-translation \
+	sched_xetparam--pidns-translation \
+	sched_xetscheduler--pidns-translation \
 	scm_rights \
 	seccomp-filter-v \
 	seccomp-strict \
@@ -204,12 +230,14 @@ check_PROGRAMS = $(PURE_EXECUTABLES) \
 	set_sigign \
 	setpgrp-exec \
 	signal_receive \
+	signal_receive--pidns-translation \
 	sleep \
 	stack-fcall \
 	stack-fcall-attach \
 	stack-fcall-mangled \
 	status-none-threads \
 	status-unfinished-threads \
+	so_peercred--pidns-translation \
 	syslog-success \
 	threads-execve \
 	threads-execve--quiet-thread-execve \
@@ -223,6 +251,9 @@ check_PROGRAMS = $(PURE_EXECUTABLES) \
 	vfork-f \
 	wait4-v \
 	waitid-v \
+	xetpgid--pidns-translation \
+	xetpriority--pidns-translation \
+	xet_robust_list--pidns-translation \
 	zeroargc \
 	# end of check_PROGRAMS
 
@@ -310,6 +341,7 @@ DECODER_TESTS = \
 	int_0x80.test \
 	inotify_init-y.test \
 	ioctl.test \
+	ioctl_block--pidns-translation.test \
 	ioctl_evdev-success.test \
 	ipc_msgbuf.test \
 	kern_features-fault.test \
@@ -381,12 +413,14 @@ MISC_TESTS = \
 	filtering_fd-syntax.test \
 	filtering_syscall-syntax.test \
 	first_exec_failure.test \
+	fork--pidns-translation.test \
 	get_regs.test \
 	inject-nf.test \
 	interactive_block.test \
 	kill_child.test \
 	localtime.test \
 	looping_threads.test \
+	netlink_audit--pidns-translation.test \
 	opipe.test \
 	options-syntax.test \
 	pc.test \
@@ -467,6 +501,7 @@ EXTRA_DIST = \
 	filter_seccomp.in \
 	filter_seccomp.sh \
 	filter-unavailable.expected \
+	fork--pidns-translation.awk \
 	fstatat.c \
 	fstatx.c \
 	gen_pure_executables.sh \
diff --git a/tests/fcntl--pidns-translation.c b/tests/fcntl--pidns-translation.c
new file mode 100644
index 00000000..e249424a
--- /dev/null
+++ b/tests/fcntl--pidns-translation.c
@@ -0,0 +1,2 @@
+#define PIDNS_TRANSLATION
+#include "fcntl.c"
diff --git a/tests/fcntl-common.c b/tests/fcntl-common.c
index 27694326..d9e29939 100644
--- a/tests/fcntl-common.c
+++ b/tests/fcntl-common.c
@@ -13,6 +13,8 @@
 #include <unistd.h>
 #include <assert.h>
 #include "flock.h"
+#include "pidns.h"
+#include "scno.h"
 
 #define FILE_LEN 4096
 
@@ -48,12 +50,14 @@ test_flock_einval(const int cmd, const char *name)
 	fl->l_len = (TYPEOF_FLOCK_OFF_T) 0xdefaced2cafef00dULL;
 
 	invoke_test_syscall(0, cmd, fl);
+	pidns_print_leader();
 	printf("%s(0, %s, {l_type=F_RDLCK, l_whence=SEEK_SET"
 	       ", l_start=%jd, l_len=%jd}) = %s\n", TEST_SYSCALL_STR, name,
 	       (intmax_t) fl->l_start, (intmax_t) fl->l_len, errstr);
 
 	void *const bad_addr = (void *) fl + 1;
 	invoke_test_syscall(0, cmd, bad_addr);
+	pidns_print_leader();
 	printf("%s(0, %s, %p) = %s\n",
 	       TEST_SYSCALL_STR, name, bad_addr, errstr);
 }
@@ -72,12 +76,14 @@ test_flock64_einval(const int cmd, const char *name)
 	fl->l_len = (TYPEOF_FLOCK_OFF_T) 0xdefaced2cafef00dULL;
 
 	invoke_test_syscall(0, cmd, fl);
+	pidns_print_leader();
 	printf("%s(0, %s, {l_type=F_RDLCK, l_whence=SEEK_SET"
 	       ", l_start=%jd, l_len=%jd}) = %s\n", TEST_SYSCALL_STR, name,
 	       (intmax_t) fl->l_start, (intmax_t) fl->l_len, errstr);
 
 	void *const bad_addr = (void *) fl + 1;
 	invoke_test_syscall(0, cmd, bad_addr);
+	pidns_print_leader();
 	printf("%s(0, %s, %p) = %s\n",
 	       TEST_SYSCALL_STR, name, bad_addr, errstr);
 }
@@ -94,6 +100,7 @@ test_flock(void)
 	fl->l_len = FILE_LEN;
 
 	long rc = invoke_test_syscall(0, F_SETLK, fl);
+	pidns_print_leader();
 	printf("%s(0, F_SETLK, {l_type=F_RDLCK, l_whence=SEEK_SET"
 	       ", l_start=0, l_len=%d}) = %s\n",
 	       TEST_SYSCALL_STR, FILE_LEN, errstr);
@@ -101,11 +108,13 @@ test_flock(void)
 		return;
 
 	invoke_test_syscall(0, F_GETLK, fl);
+	pidns_print_leader();
 	printf("%s(0, F_GETLK, {l_type=F_UNLCK, l_whence=SEEK_SET"
 	       ", l_start=0, l_len=%d, l_pid=0}) = 0\n",
 	       TEST_SYSCALL_STR, FILE_LEN);
 
 	invoke_test_syscall(0, F_SETLKW, fl);
+	pidns_print_leader();
 	printf("%s(0, F_SETLKW, {l_type=F_UNLCK, l_whence=SEEK_SET"
 	       ", l_start=0, l_len=%d}) = 0\n",
 	       TEST_SYSCALL_STR, FILE_LEN);
@@ -124,6 +133,7 @@ test_flock64_ofd(void)
 	fl->l_len = FILE_LEN;
 
 	long rc = invoke_test_syscall(0, F_OFD_SETLK, fl);
+	pidns_print_leader();
 	printf("%s(0, F_OFD_SETLK, {l_type=F_RDLCK, l_whence=SEEK_SET"
 	       ", l_start=0, l_len=%d}) = %s\n",
 	       TEST_SYSCALL_STR, FILE_LEN, errstr);
@@ -131,11 +141,13 @@ test_flock64_ofd(void)
 		return;
 
 	invoke_test_syscall(0, F_OFD_GETLK, fl);
+	pidns_print_leader();
 	printf("%s(0, F_OFD_GETLK, {l_type=F_UNLCK, l_whence=SEEK_SET"
 	       ", l_start=0, l_len=%d, l_pid=0}) = 0\n",
 	       TEST_SYSCALL_STR, FILE_LEN);
 
 	invoke_test_syscall(0, F_OFD_SETLKW, fl);
+	pidns_print_leader();
 	printf("%s(0, F_OFD_SETLKW, {l_type=F_UNLCK, l_whence=SEEK_SET"
 	       ", l_start=0, l_len=%d}) = 0\n",
 	       TEST_SYSCALL_STR, FILE_LEN);
@@ -167,18 +179,21 @@ test_flock64(void)
 static long
 test_f_owner_ex_type_pid(const int cmd, const char *const cmd_name,
 			 const int type, const char *const type_name,
-			 pid_t pid)
+			 enum pid_type pid_type, pid_t pid)
 {
 	TAIL_ALLOC_OBJECT_CONST_PTR(struct_kernel_f_owner_ex, fo);
 
 	fo->type = type;
 	fo->pid = pid;
 	long rc = invoke_test_syscall(0, cmd, fo);
-	printf("%s(0, %s, {type=%s, pid=%d}) = %s\n",
-	       TEST_SYSCALL_STR, cmd_name, type_name, fo->pid, errstr);
+	pidns_print_leader();
+	printf("%s(0, %s, {type=%s, pid=%d%s}) = %s\n",
+	       TEST_SYSCALL_STR, cmd_name, type_name,
+	       fo->pid, pidns_pid2str(pid_type), errstr);
 
 	void *bad_addr = (void *) fo + 1;
 	invoke_test_syscall(0, cmd, bad_addr);
+	pidns_print_leader();
 	printf("%s(0, %s, %p) = %s\n",
 	       TEST_SYSCALL_STR, cmd_name, bad_addr, errstr);
 
@@ -187,35 +202,39 @@ test_f_owner_ex_type_pid(const int cmd, const char *const cmd_name,
 
 static void
 test_f_owner_ex_umove_or_printaddr(const int type, const char *const type_name,
-				   pid_t pid)
+				   enum pid_type pid_type, pid_t pid)
 {
 	long rc = test_f_owner_ex_type_pid(ARG_STR(F_SETOWN_EX),
-					   type, type_name, pid);
+					   type, type_name, pid_type, pid);
 	if (!rc)
 		test_f_owner_ex_type_pid(ARG_STR(F_GETOWN_EX),
-					 type, type_name, pid);
+					 type, type_name, pid_type, pid);
 }
 
 static void
 test_f_owner_ex(void)
 {
-	static const struct {
+	struct {
 		int type;
 		const char *type_name;
-		pid_t pid[2];
+		enum pid_type pid_type;
+		pid_t pid;
 	} a[] = {
-		{ ARG_STR(F_OWNER_TID), { 1234567890, 20 } },
-		{ ARG_STR(F_OWNER_PID), { 1298126790, 30 } },
-		{ ARG_STR(F_OWNER_PGRP), { 1294567890, 40 } }
+		{ ARG_STR(F_OWNER_TID), PT_NONE, 1234567890 },
+		{ ARG_STR(F_OWNER_PID), PT_NONE, 1234567890 },
+		{ ARG_STR(F_OWNER_PGRP), PT_NONE, 1234567890 },
+		{ ARG_STR(F_OWNER_TID), PT_TID, 0 },
+		{ ARG_STR(F_OWNER_PID), PT_TGID, 0 },
+		{ ARG_STR(F_OWNER_PGRP), PT_PGID, 0 },
 	};
 
-	for (unsigned int i = 0; i < ARRAY_SIZE(a); i++) {
-		for (unsigned int j = 0; j < ARRAY_SIZE(a[0].pid); j++) {
-			test_f_owner_ex_umove_or_printaddr(a[i].type,
-							   a[i].type_name,
-							   a[i].pid[j]);
-		}
-	}
+	a[3].pid = syscall(__NR_gettid);
+	a[4].pid = getpid();
+	a[5].pid = getpgid(0);
+
+	for (unsigned int i = 0; i < ARRAY_SIZE(a); i++)
+		test_f_owner_ex_umove_or_printaddr(a[i].type, a[i].type_name,
+			a[i].pid_type, a[i].pid);
 }
 #endif /* TEST_F_OWNER_EX */
 
@@ -228,6 +247,23 @@ struct fcntl_cmd_check {
 	void (*print_flags)(long rc);
 };
 
+static void
+test_xetown(void)
+{
+	const int pid = getpid();
+	const char *pid_str = pidns_pid2str(PT_TGID);
+
+	invoke_test_syscall(0, F_SETOWN, (void *) (intptr_t) pid);
+	pidns_print_leader();
+	printf("%s(0, F_SETOWN, %d%s) = %s\n",
+		TEST_SYSCALL_STR, pid, pid_str, errstr);
+
+	invoke_test_syscall(0, F_GETOWN, NULL);
+	pidns_print_leader();
+	printf("%s(0, F_GETOWN) = %d%s\n",
+		TEST_SYSCALL_STR, pid, pid_str);
+}
+
 static void
 print_retval_flags(const struct fcntl_cmd_check *check, long rc)
 {
@@ -243,12 +279,14 @@ static void
 test_other_set_cmd(const struct fcntl_cmd_check *check)
 {
 	invoke_test_syscall(check->fd, check->cmd, (void *) check->arg);
+	pidns_print_leader();
 	printf("%s(%d, %s, %s) = %s\n",
 	       TEST_SYSCALL_STR, check->fd,
 	       check->cmd_str, check->arg_str, errstr);
 
 	/* bad file fd */
 	invoke_test_syscall(-1, check->cmd, (void *) check->arg);
+	pidns_print_leader();
 	printf("%s(-1, %s, %s) = %s\n",
 	       TEST_SYSCALL_STR, check->cmd_str,
 	       check->arg_str, errstr);
@@ -258,12 +296,14 @@ static void
 test_other_get_cmd(const struct fcntl_cmd_check *check)
 {
 	long rc = invoke_test_syscall(check->fd, check->cmd, NULL);
+	pidns_print_leader();
 	printf("%s(%d, %s) = ",
 	       TEST_SYSCALL_STR, check->fd, check->cmd_str);
 	print_retval_flags(check, rc);
 
 	/* bad file fd */
 	invoke_test_syscall(-1, check->cmd, NULL);
+	pidns_print_leader();
 	printf("%s(-1, %s) = %s\n",
 	       TEST_SYSCALL_STR, check->cmd_str, errstr);
 }
@@ -315,7 +355,6 @@ test_fcntl_others(void)
 {
 	static const struct fcntl_cmd_check set_checks[] = {
 		{ 0, ARG_STR(F_SETFD), ARG_STR(FD_CLOEXEC) },
-		{ 0, ARG_STR(F_SETOWN), ARG_STR(20) },
 #ifdef F_SETPIPE_SZ
 		{ 0, ARG_STR(F_SETPIPE_SZ), ARG_STR(4097) },
 #endif
@@ -336,7 +375,6 @@ test_fcntl_others(void)
 	static const struct fcntl_cmd_check get_checks[] = {
 		{ 0, ARG_STR(F_GETFD), .print_flags = print_flags_getfd },
 		{ 1, ARG_STR(F_GETFD), .print_flags = print_flags_getfd },
-		{ 0, ARG_STR(F_GETOWN) },
 #ifdef F_GETPIPE_SZ
 		{ 0, ARG_STR(F_GETPIPE_SZ) },
 #endif
@@ -360,6 +398,8 @@ create_sample(void)
 int
 main(void)
 {
+	PIDNS_TEST_INIT;
+
 	create_sample();
 	test_flock();
 	test_flock64();
@@ -367,7 +407,9 @@ main(void)
 	test_f_owner_ex();
 #endif
 	test_fcntl_others();
+	test_xetown();
 
+	pidns_print_leader();
 	puts("+++ exited with 0 +++");
 	return 0;
 }
diff --git a/tests/fcntl.c b/tests/fcntl.c
index f38b8afb..673c06e4 100644
--- a/tests/fcntl.c
+++ b/tests/fcntl.c
@@ -24,6 +24,7 @@ test_flock64_undecoded(const int cmd, const char *name)
 		.l_len = 0xdefaced2cafef00dULL
 	};
 	invoke_test_syscall(0, cmd, &fl);
+	pidns_print_leader();
 	printf("%s(0, %s, %p) = %s\n",
 	       TEST_SYSCALL_STR, name, &fl, errstr);
 }
diff --git a/tests/fcntl64--pidns-translation.c b/tests/fcntl64--pidns-translation.c
new file mode 100644
index 00000000..c6fdadd1
--- /dev/null
+++ b/tests/fcntl64--pidns-translation.c
@@ -0,0 +1,2 @@
+#define PIDNS_TRANSLATION
+#include "fcntl64.c"
diff --git a/tests/fcntl64.c b/tests/fcntl64.c
index 78e53b0d..f7b3f2fb 100644
--- a/tests/fcntl64.c
+++ b/tests/fcntl64.c
@@ -27,6 +27,7 @@ test_flock64_lk64(void)
 	fl->l_len = FILE_LEN;
 
 	long rc = invoke_test_syscall(0, F_SETLK64, fl);
+	pidns_print_leader();
 	printf("%s(0, F_SETLK64, {l_type=F_RDLCK, l_whence=SEEK_SET"
 	       ", l_start=0, l_len=%d}) = %s\n",
 	       TEST_SYSCALL_STR, FILE_LEN, errstr);
@@ -35,11 +36,13 @@ test_flock64_lk64(void)
 		return;
 
 	invoke_test_syscall(0, F_GETLK64, fl);
+	pidns_print_leader();
 	printf("%s(0, F_GETLK64, {l_type=F_UNLCK, l_whence=SEEK_SET"
 	       ", l_start=0, l_len=%d, l_pid=0}) = 0\n",
 	       TEST_SYSCALL_STR, FILE_LEN);
 
 	invoke_test_syscall(0, F_SETLKW64, fl);
+	pidns_print_leader();
 	printf("%s(0, F_SETLKW64, {l_type=F_UNLCK, l_whence=SEEK_SET"
 	       ", l_start=0, l_len=%d}) = 0\n",
 	       TEST_SYSCALL_STR, FILE_LEN);
diff --git a/tests/fork--pidns-translation.awk b/tests/fork--pidns-translation.awk
new file mode 100644
index 00000000..ef6858f4
--- /dev/null
+++ b/tests/fork--pidns-translation.awk
@@ -0,0 +1,15 @@
+/fork/ {
+        match($0, "([0-9]+) in strace\x27s PID NS", a);
+        if (a[1])
+                fork_pid = a[1]
+}
+
+/exited with 0/ {
+        if (!exit_pid)
+                exit_pid = $1
+}
+
+END {
+        if (!fork_pid || !exit_pid || fork_pid != exit_pid)
+                exit 1
+}
diff --git a/tests/fork--pidns-translation.c b/tests/fork--pidns-translation.c
new file mode 100644
index 00000000..73c39d5d
--- /dev/null
+++ b/tests/fork--pidns-translation.c
@@ -0,0 +1,69 @@
+/*
+ * Test PID namespace translation
+ *
+ * Copyright (c) 2020 ?kos Uzonyi <uzonyi.akos at gmail.com>
+ * All rights reserved.
+ *
+ * SPDX-License-Identifier: LGPL-2.1-or-later
+ */
+
+#include "tests.h"
+#include "scno.h"
+#include "pidns.h"
+
+#ifdef __NR_fork
+
+#include <errno.h>
+#include <limits.h>
+#include <sched.h>
+#include <signal.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <sys/wait.h>
+#include <unistd.h>
+#include <linux/sched.h>
+
+static int
+fork_chain(int depth)
+{
+	if (!depth)
+		return 0;
+
+	int pid = syscall(__NR_fork);
+	if (pid < 0)
+		return errno;
+
+	if (!pid)
+		_exit(fork_chain(depth - 1));
+
+	int status;
+	if (wait(&status) < 0)
+		return errno;
+
+	if (!WIFEXITED(status))
+		return -1;
+
+	return WEXITSTATUS(status);
+}
+
+int main(void)
+{
+	check_ns_ioctl();
+
+	if (unshare(CLONE_NEWPID | CLONE_NEWUSER) < 0) {
+		if (errno == EPERM)
+			perror_msg_and_skip("unshare");
+
+		perror_msg_and_fail("unshare");
+	}
+
+	errno = fork_chain(2);
+	if (errno)
+		perror("fork_chain");
+}
+
+#else
+
+SKIP_MAIN_UNDEFINED("__NR_fork")
+
+#endif
diff --git a/tests/fork--pidns-translation.test b/tests/fork--pidns-translation.test
new file mode 100755
index 00000000..fa7ecda5
--- /dev/null
+++ b/tests/fork--pidns-translation.test
@@ -0,0 +1,16 @@
+#!/bin/sh
+#
+# Check pidns translation of fork's return value.
+#
+# Copyright (c) 2020 The strace developers.
+# All rights reserved.
+#
+# SPDX-License-Identifier: LGPL-2.1-or-later
+
+. "${srcdir=.}/init.sh"
+
+require_min_kernel_version_or_skip 4.9
+
+run_prog
+run_strace -a6 --pidns-translation -f -e trace=fork $args
+match_awk
diff --git a/tests/gen_tests.in b/tests/gen_tests.in
index 6f8e1420..56e5b5e1 100644
--- a/tests/gen_tests.in
+++ b/tests/gen_tests.in
@@ -93,7 +93,9 @@ fchown	-a16
 fchown32	-a18
 fchownat
 fcntl	-a8
+fcntl--pidns-translation	test_pidns -a8 -e trace=fcntl
 fcntl64	-a8
+fcntl64--pidns-translation	test_pidns -a8 -e trace=fcntl64
 fdatasync	-a14
 file_handle	-e trace=name_to_handle_at,open_by_handle_at
 file_ioctl	+ioctl.test
@@ -147,7 +149,9 @@ getgroups	-a17
 getgroups32	-a19
 getpeername	-a27
 getpgrp	-a10
+getpgrp--pidns-translation	test_pidns -e trace=getpgrp -a10
 getpid	-a9
+getpid--pidns-translation	test_pidns -e trace=getpid -a9
 getppid	-a10
 getrandom	-a32 -s3
 getresgid	-a25
@@ -157,8 +161,10 @@ getresuid32	-a27
 getrlimit	-a27
 getrusage	-v
 getsid	-a10
+getsid--pidns-translation	test_pidns -e trace=getsid -a10
 getsockname	-a27
 gettid	-a9
+gettid--pidns-translation	test_pidns -e trace=gettid -a9
 getuid-creds	+getuid.test
 getuid32	+getuid.test
 getuid32-creds	+getuid.test
@@ -250,6 +256,7 @@ ioctl_watchdog	+ioctl.test
 ioperm	-a27
 iopl	-a8
 ioprio	-a18 -e trace=ioprio_get,ioprio_set
+ioprio--pidns-translation	test_pidns -a18 -e trace=ioprio_get,ioprio_set
 ioprio-Xabbrev	-a18 -e trace=ioprio_get,ioprio_set -Xabbrev
 ioprio-Xraw	-a18 -e trace=ioprio_get,ioprio_set -Xraw
 ioprio-Xverbose	-a18 -e trace=ioprio_get,ioprio_set -Xverbose
@@ -272,6 +279,7 @@ ipc_shm-Xraw	+ipc.sh -Xraw -a19
 ipc_shm-Xverbose	+ipc.sh -Xverbose -a34
 kcmp	-a22
 kcmp-y	-a22 -y -e trace=kcmp
+kcmp-y--pidns-translation	test_pidns -a22 -y -e trace=kcmp
 kern_features -a16
 kernel_version	-a16 -v -e trace=bpf
 kernel_version-Xabbrev	-a16 -Xabbrev -v -e trace=bpf
@@ -284,6 +292,7 @@ keyctl-Xabbrev	-a31 -s10 -e trace=keyctl -Xabbrev
 keyctl-Xraw	-a13 -s10 -e trace=keyctl -Xraw
 keyctl-Xverbose	-a41 -s10 -e trace=keyctl -Xverbose
 kill	-a12 -esignal=none
+kill--pidns-translation	test_pidns -a12 -e trace=kill -esignal=none
 ksysent	../$NAME
 lchown	-a30
 lchown32	-a32
@@ -305,6 +314,7 @@ memfd_create-Xabbrev	-Xabbrev -e trace=memfd_create
 memfd_create-Xraw	-a30 -Xraw -e trace=memfd_create
 memfd_create-Xverbose	-Xverbose -e trace=memfd_create
 migrate_pages	-a33
+migrate_pages--pidns-translation	test_pidns -a33 -e trace=migrate_pages
 mincore	-a22
 mkdir	-a20
 mkdirat	-a28
@@ -335,6 +345,7 @@ move_pages	-s3
 move_pages-Xabbrev	-s3 -e trace=move_pages -Xabbrev
 move_pages-Xraw	-s3 -a36 -e trace=move_pages -Xraw
 move_pages-Xverbose	-s3 -e trace=move_pages -Xverbose
+move_pages--pidns-translation	test_pidns -s3 -e trace=move_pages
 mq	-a32 -e trace=mq_getsetattr,mq_open,mq_unlink
 mq_sendrecv	-a14 -e trace=mq_open,mq_notify,mq_timedsend,mq_timedreceive,mq_unlink
 mq_sendrecv-read	-eread=0 -a14 -e trace=mq_open,mq_notify,mq_timedsend,mq_timedreceive,mq_unlink
@@ -354,6 +365,7 @@ net-packet_mreq-Xabbrev	-e trace=setsockopt -Xabbrev
 net-packet_mreq-Xraw	-e trace=setsockopt -Xraw
 net-packet_mreq-Xverbose	-e trace=setsockopt -Xverbose
 net-sockaddr	-a24 -e trace=connect
+net-sockaddr--pidns-translation	test_pidns -a24 -e trace=connect
 net-tpacket_req -e trace=setsockopt
 net-tpacket_stats -e trace=getsockopt
 net-yy-inet6	+net-yy-inet.test
@@ -457,7 +469,9 @@ pidfd_open--decode-fd-socket	-a17 -e decode-fd=socket -e trace=pidfd_open
 pidfd_open-P	-a17 -P /dev/full -e trace=pidfd_open
 pidfd_open-y	-a17 -y -e trace=pidfd_open
 pidfd_open-yy	-a17 -yy -e trace=pidfd_open
+pidfd_open--pidns-translation	test_pidns -a17 -e trace=pidfd_open
 pidfd_send_signal
+pidfd_send_signal--pidns-translation test_pidns -e trace=pidfd_send_signal
 pipe2	-a15
 pkey_alloc	-a17
 pkey_free	-a13
@@ -480,8 +494,11 @@ printstrn-umoven	-s4096 -e signal=none -e trace=add_key
 printstrn-umoven-peekdata	-e signal=none -e trace=add_key
 printstrn-umoven-undumpable	-e signal=none -e trace=add_key
 prlimit64
+prlimit64--pidns-translation     test_pidns -e trace=prlimit64
 process_vm_readv	-s5 -a37
+process_vm_readv--pidns-translation	test_pidns -s5 -a37 -e trace=process_vm_readv
 process_vm_writev	-s5 -a38
+process_vm_writev--pidns-translation	test_pidns -s5 -a38 -e trace=process_vm_writev
 pselect6
 ptrace	-a23 -e signal=none
 ptrace_syscall_info	-a35 -e signal=none -e trace=ptrace
@@ -518,10 +535,12 @@ rmdir	-a22
 rt_sigpending	-a20
 rt_sigprocmask
 rt_sigqueueinfo	-esignal=none
+rt_sigqueueinfo--pidns-translation	test_pidns -esignal=none -e trace=rt_sigqueueinfo
 rt_sigreturn	-esignal='!USR1'
 rt_sigsuspend	-a20 -esignal=none
 rt_sigtimedwait	-a38
 rt_tgsigqueueinfo	-esignal=none
+rt_tgsigqueueinfo--pidns-translation	test_pidns -esignal=none -e trace=rt_tgsigqueueinfo
 s390_guarded_storage	-a32
 s390_guarded_storage-v	-e trace=s390_guarded_storage -a32 -v
 s390_pci_mmio_read_write	-e trace=s390_pci_mmio_read,s390_pci_mmio_write -a30
@@ -532,9 +551,13 @@ sched	test_trace_expr times -e/sched
 sched_get_priority_mxx	-a33 -e trace=sched_get_priority_min,sched_get_priority_max
 sched_rr_get_interval	-a31
 sched_xetaffinity	-a28 -e trace=sched_getaffinity,sched_setaffinity
+sched_xetaffinity--pidns-translation	test_pidns -a28 -e trace=sched_getaffinity,sched_setaffinity
 sched_xetattr	-a29 -e trace=sched_getattr,sched_setattr
+sched_xetattr--pidns-translation	test_pidns -a29 -e trace=sched_getattr,sched_setattr
 sched_xetparam	-a23 -e trace=sched_getparam,sched_setparam
+sched_xetparam--pidns-translation	test_pidns -a23 -e trace=sched_getparam,sched_setparam
 sched_xetscheduler	-a22 -e trace=sched_getscheduler,sched_setscheduler
+sched_xetscheduler--pidns-translation	test_pidns -a22 -e trace=sched_getscheduler,sched_setscheduler
 sched_yield	-a14
 seccomp-filter	-e trace=seccomp
 seccomp-filter-v	-v -e trace=seccomp
@@ -581,6 +604,7 @@ sigaction	-a31
 siginfo	-e trace=none
 signal	-a25 -e signal=none -e trace='/^signal$'
 signal_receive	-a16 -e trace=kill
+signal_receive--pidns-translation	test_pidns -a16 -e trace=kill
 signalfd4
 sigpending	-a15
 sigprocmask	-a34
@@ -592,6 +616,7 @@ so_peercred	-e trace=getsockopt
 so_peercred-Xabbrev	-e trace=getsockopt -Xabbrev
 so_peercred-Xraw	-e trace=getsockopt -Xraw -a39
 so_peercred-Xverbose	-e trace=getsockopt -Xverbose
+so_peercred--pidns-translation	test_pidns -e trace=getsockopt
 sock_filter-v	-v -e trace=getsockopt,setsockopt
 sock_filter-v-Xabbrev	-v -e trace=getsockopt,setsockopt -X abbrev
 sock_filter-v-Xraw	-a 37 -v -e trace=getsockopt,setsockopt -X raw
@@ -721,7 +746,10 @@ waitpid	-a28
 xattr	-a22 -e trace=getxattr,fgetxattr,lgetxattr,setxattr,fsetxattr,lsetxattr,listxattr,flistxattr,llistxattr,removexattr,fremovexattr,lremovexattr
 xattr-strings	-a22 -s 4 -e trace=fsetxattr
 xet_robust_list	-a24 -e trace=get_robust_list,set_robust_list
+xet_robust_list--pidns-translation	test_pidns -a24 -e trace=get_robust_list,set_robust_list
 xetitimer	-a29 -e trace=setitimer,getitimer
 xetpgid	-a11 -e trace=getpgid,setpgid
-xetpriority	-a29 -e trace=getpriority,setpriority
+xetpgid--pidns-translation	test_pidns -a11 -e trace=getpgid,setpgid
+xetpriority	-a27 -e trace=getpriority,setpriority
+xetpriority--pidns-translation	test_pidns -a27 -e trace=getpriority,setpriority
 xettimeofday	-a20 -e trace=gettimeofday,settimeofday
diff --git a/tests/getpgrp--pidns-translation.c b/tests/getpgrp--pidns-translation.c
new file mode 100644
index 00000000..de8ceb33
--- /dev/null
+++ b/tests/getpgrp--pidns-translation.c
@@ -0,0 +1,2 @@
+#define PIDNS_TRANSLATION
+#include "getpgrp.c"
diff --git a/tests/getpgrp.c b/tests/getpgrp.c
index 104f4811..3f0b9dd1 100644
--- a/tests/getpgrp.c
+++ b/tests/getpgrp.c
@@ -7,6 +7,7 @@
 
 #include "tests.h"
 #include "scno.h"
+#include "pidns.h"
 
 #ifdef __NR_getpgrp
 
@@ -16,8 +17,13 @@
 int
 main(void)
 {
-	printf("getpgrp() = %ld\n", syscall(__NR_getpgrp));
+	PIDNS_TEST_INIT;
 
+	pidns_print_leader();
+	printf("getpgrp() = %d%s\n", (int) syscall(__NR_getpgrp),
+		pidns_pid2str(PT_PGID));
+
+	pidns_print_leader();
 	puts("+++ exited with 0 +++");
 	return 0;
 }
diff --git a/tests/getpid--pidns-translation.c b/tests/getpid--pidns-translation.c
new file mode 100644
index 00000000..94b12a1a
--- /dev/null
+++ b/tests/getpid--pidns-translation.c
@@ -0,0 +1,2 @@
+#define PIDNS_TRANSLATION
+#include "getpid.c"
diff --git a/tests/getpid.c b/tests/getpid.c
index 988f19d5..7ec4e6e8 100644
--- a/tests/getpid.c
+++ b/tests/getpid.c
@@ -7,6 +7,7 @@
 
 #include "tests.h"
 #include "scno.h"
+#include "pidns.h"
 
 #if defined __NR_getpid && (!defined __NR_getxpid || __NR_getxpid != __NR_getpid)
 
@@ -16,7 +17,12 @@
 int
 main(void)
 {
-	printf("getpid() = %ld\n", syscall(__NR_getpid));
+	PIDNS_TEST_INIT;
+
+	pidns_print_leader();
+	printf("getpid() = %d%s\n", (int) syscall(__NR_getpid),
+		pidns_pid2str(PT_TGID));
+	pidns_print_leader();
 	puts("+++ exited with 0 +++");
 	return 0;
 }
diff --git a/tests/getsid--pidns-translation.c b/tests/getsid--pidns-translation.c
new file mode 100644
index 00000000..7f983e87
--- /dev/null
+++ b/tests/getsid--pidns-translation.c
@@ -0,0 +1,2 @@
+#define PIDNS_TRANSLATION
+#include "getsid.c"
diff --git a/tests/getsid.c b/tests/getsid.c
index 588ea4ab..3bf74734 100644
--- a/tests/getsid.c
+++ b/tests/getsid.c
@@ -6,15 +6,22 @@
  */
 
 #include "tests.h"
+#include "pidns.h"
+
 #include <stdio.h>
 #include <unistd.h>
 
 int
 main(void)
 {
+	PIDNS_TEST_INIT;
+
 	pid_t pid = getpid();
-	printf("getsid(%d) = %d\n", pid, getsid(pid));
+	pidns_print_leader();
+	printf("getsid(%d%s) = %d%s\n", pid, pidns_pid2str(PT_TGID),
+		getsid(pid), pidns_pid2str(PT_SID));
 
+	pidns_print_leader();
 	puts("+++ exited with 0 +++");
 	return 0;
 }
diff --git a/tests/gettid--pidns-translation.c b/tests/gettid--pidns-translation.c
new file mode 100644
index 00000000..500c3213
--- /dev/null
+++ b/tests/gettid--pidns-translation.c
@@ -0,0 +1,2 @@
+#define PIDNS_TRANSLATION
+#include "gettid.c"
diff --git a/tests/gettid.c b/tests/gettid.c
index d38918dd..314d9c2c 100644
--- a/tests/gettid.c
+++ b/tests/gettid.c
@@ -9,11 +9,17 @@
 #include <stdio.h>
 #include <unistd.h>
 #include "scno.h"
+#include "pidns.h"
 
 int
 main(void)
 {
-	printf("gettid() = %ld\n", syscall(__NR_gettid));
+	PIDNS_TEST_INIT;
+
+	pidns_print_leader();
+	printf("gettid() = %d%s\n", (int) syscall(__NR_gettid),
+		pidns_pid2str(PT_TID));
+	pidns_print_leader();
 	puts("+++ exited with 0 +++");
 	return 0;
 }
diff --git a/tests/ioctl_block--pidns-translation.c b/tests/ioctl_block--pidns-translation.c
new file mode 100644
index 00000000..5eed6076
--- /dev/null
+++ b/tests/ioctl_block--pidns-translation.c
@@ -0,0 +1,2 @@
+#define PIDNS_TRANSLATION
+#include "ioctl_block.c"
diff --git a/tests/ioctl_block--pidns-translation.test b/tests/ioctl_block--pidns-translation.test
new file mode 100755
index 00000000..bb45f695
--- /dev/null
+++ b/tests/ioctl_block--pidns-translation.test
@@ -0,0 +1,24 @@
+#!/bin/sh
+#
+# Check ioctl syscall decoding.
+#
+# Copyright (c) 2020 The strace developers.
+# All rights reserved.
+#
+# SPDX-License-Identifier: LGPL-2.1-or-later
+
+. "${srcdir=.}/init.sh"
+
+require_min_kernel_version_or_skip 4.9
+
+check_prog head
+check_prog tail
+check_prog cut
+check_prog grep
+
+run_prog > /dev/null
+run_strace --pidns-translation -f -a16 -e trace=ioctl $@ $args > "$EXP"
+parent_pid="$(tail -n 2 $LOG | head -n 1 | cut -d' ' -f1)"
+init_pid="$(tail -n 1 $LOG | cut -d' ' -f1)"
+grep -E -v "^($parent_pid|$init_pid) |ioctl\([0123][,<]" "$LOG" > "$OUT"
+match_diff "$OUT" "$EXP"
diff --git a/tests/ioctl_block.c b/tests/ioctl_block.c
index 67fee35c..64677e85 100644
--- a/tests/ioctl_block.c
+++ b/tests/ioctl_block.c
@@ -9,7 +9,9 @@
  */
 
 #include "tests.h"
+#include "pidns.h"
 #include <errno.h>
+#include <unistd.h>
 #include <inttypes.h>
 #include <stdio.h>
 #include <string.h>
@@ -41,12 +43,15 @@ static struct xlat_data block_argless[] = {
 #define TEST_NULL_ARG(cmd)						\
 	do {								\
 		ioctl(-1, cmd, 0);					\
+		pidns_print_leader();					\
 		printf("ioctl(-1, %s, NULL) = -1 EBADF (%m)\n", #cmd);	\
 	} while (0)
 
 int
 main(void)
 {
+	PIDNS_TEST_INIT;
+
 	TEST_NULL_ARG(BLKBSZGET);
 	TEST_NULL_ARG(BLKBSZSET);
 	TEST_NULL_ARG(BLKFRAGET);
@@ -91,18 +96,22 @@ main(void)
 #endif
 
 	ioctl(-1, BLKRASET, lmagic);
+	pidns_print_leader();
 	printf("ioctl(-1, BLKRASET, %lu) = -1 EBADF (%m)\n", lmagic);
 
 	ioctl(-1, BLKFRASET, lmagic);
+	pidns_print_leader();
 	printf("ioctl(-1, BLKFRASET, %lu) = -1 EBADF (%m)\n", lmagic);
 
 	TAIL_ALLOC_OBJECT_CONST_PTR(int, val_int);
 	*val_int = magic;
 
 	ioctl(-1, BLKROSET, val_int);
+	pidns_print_leader();
 	printf("ioctl(-1, BLKROSET, [%d]) = -1 EBADF (%m)\n", *val_int);
 
 	ioctl(-1, BLKBSZSET, val_int);
+	pidns_print_leader();
 	printf("ioctl(-1, BLKBSZSET, [%d]) = -1 EBADF (%m)\n", *val_int);
 
 	uint64_t *pair_int64 = tail_alloc(sizeof(*pair_int64) * 2);
@@ -111,18 +120,21 @@ main(void)
 
 #ifdef BLKDISCARD
 	ioctl(-1, BLKDISCARD, pair_int64);
+	pidns_print_leader();
 	printf("ioctl(-1, BLKDISCARD, [%" PRIu64 ", %" PRIu64 "])"
 	       " = -1 EBADF (%m)\n", pair_int64[0], pair_int64[1]);
 #endif
 
 #ifdef BLKSECDISCARD
 	ioctl(-1, BLKSECDISCARD, pair_int64);
+	pidns_print_leader();
 	printf("ioctl(-1, BLKSECDISCARD, [%" PRIu64 ", %" PRIu64 "])"
 	       " = -1 EBADF (%m)\n", pair_int64[0], pair_int64[1]);
 #endif
 
 #ifdef BLKZEROOUT
 	ioctl(-1, BLKZEROOUT, pair_int64);
+	pidns_print_leader();
 	printf("ioctl(-1, BLKZEROOUT, [%" PRIu64 ", %" PRIu64 "])"
 	       " = -1 EBADF (%m)\n", pair_int64[0], pair_int64[1]);
 #endif
@@ -134,6 +146,7 @@ main(void)
 	blkpg->data = (void *) (unsigned long) 0xcafef00dfffffeedULL;
 
 	ioctl(-1, BLKPG, blkpg);
+	pidns_print_leader();
 	printf("ioctl(-1, BLKPG, {op=%s, flags=%d, datalen=%d"
 	       ", data=%#lx}) = -1 EBADF (%m)\n",
 	       "BLKPG_RESIZE_PARTITION", blkpg->flags, blkpg->datalen,
@@ -149,6 +162,7 @@ main(void)
 	blkpg->data = bp;
 
 	ioctl(-1, BLKPG, blkpg);
+	pidns_print_leader();
 	printf("ioctl(-1, BLKPG, {op=%s, flags=%d, datalen=%d"
 	       ", data={start=%lld, length=%lld, pno=%d"
 	       ", devname=\"%.*s\"..., volname=\"%.*s\"...}})"
@@ -162,25 +176,31 @@ main(void)
 #if defined BLKTRACESETUP && defined HAVE_STRUCT_BLK_USER_TRACE_SETUP
 	TAIL_ALLOC_OBJECT_CONST_PTR(struct blk_user_trace_setup, buts);
 	fill_memory(buts, sizeof(*buts));
+	buts->pid = getpid();
 
 	ioctl(-1, BLKTRACESETUP, buts);
+	pidns_print_leader();
 	printf("ioctl(-1, BLKTRACESETUP, {act_mask=%hu, buf_size=%u, buf_nr=%u"
-	       ", start_lba=%" PRI__u64 ", end_lba=%" PRI__u64 ", pid=%d})"
+	       ", start_lba=%" PRI__u64 ", end_lba=%" PRI__u64 ", pid=%d%s})"
 	       " = -1 EBADF (%m)\n",
 	       buts->act_mask, buts->buf_size, buts->buf_nr,
-	       buts->start_lba, buts->end_lba, buts->pid);
+	       buts->start_lba, buts->end_lba, buts->pid,
+	       pidns_pid2str(PT_TGID));
 #endif
 
 	unsigned int i;
 	for (i = 0; i < ARRAY_SIZE(block_argless); ++i) {
 		ioctl(-1, (unsigned long) block_argless[i].val, lmagic);
+		pidns_print_leader();
 		printf("ioctl(-1, %s) = -1 EBADF (%m)\n", block_argless[i].str);
 	}
 
 	ioctl(-1, _IOC(_IOC_READ, 0x12, 0xfe, 0xff), lmagic);
+	pidns_print_leader();
 	printf("ioctl(-1, %s, %#lx) = -1 EBADF (%m)\n",
 	       "_IOC(_IOC_READ, 0x12, 0xfe, 0xff)", lmagic);
 
+	pidns_print_leader();
 	puts("+++ exited with 0 +++");
 	return 0;
 }
diff --git a/tests/ioprio--pidns-translation.c b/tests/ioprio--pidns-translation.c
new file mode 100644
index 00000000..bcb49a8b
--- /dev/null
+++ b/tests/ioprio--pidns-translation.c
@@ -0,0 +1,2 @@
+#define PIDNS_TRANSLATION
+#include "ioprio.c"
diff --git a/tests/ioprio.c b/tests/ioprio.c
index 5e1e1194..110df063 100644
--- a/tests/ioprio.c
+++ b/tests/ioprio.c
@@ -9,8 +9,8 @@
  */
 
 #include "tests.h"
-
 #include "scno.h"
+#include "pidns.h"
 
 #if defined(__NR_ioprio_get) && defined(__NR_ioprio_set)
 
@@ -30,12 +30,18 @@ enum {
 int
 main(void)
 {
+	PIDNS_TEST_INIT;
+
 	static const kernel_ulong_t bogus_which =
 		(kernel_ulong_t) 0xdeadfacefa57beefULL;
 	static const kernel_ulong_t bogus_who =
 		(kernel_ulong_t) 0xbadc0dedda7a1057ULL;
 	static const kernel_ulong_t bogus_ioprio =
 		(kernel_ulong_t) 0xdec0ded1facefeedULL;
+
+	const int pid = getpid();
+	const int pgid = getpgid(0);
+
 # if !XLAT_RAW
 	static const char * const bogus_ioprio_str =
 		"IOPRIO_PRIO_VALUE(0x7d677 /* IOPRIO_CLASS_??? */, 7917)";
@@ -46,6 +52,7 @@ main(void)
 
 	rc = syscall(__NR_ioprio_get, bogus_which, bogus_who);
 	errstr = sprintrc(rc);
+	pidns_print_leader();
 # if XLAT_RAW
 	printf("ioprio_get(%#x, %d) = %s\n",
 	       (int) bogus_which, (int) bogus_who, errstr);
@@ -54,42 +61,52 @@ main(void)
 	       (int) bogus_which, (int) bogus_who, errstr);
 # endif
 
-	rc = syscall(__NR_ioprio_get, 1, 0);
+	rc = syscall(__NR_ioprio_get, 1, pid);
 	errstr = sprintrc(rc);
+	pidns_print_leader();
+	printf("ioprio_get(");
 # if XLAT_RAW
-	printf("ioprio_get(0x1, 0) = %s\n", errstr);
+	printf("0x1, ");
+# elif XLAT_VERBOSE
+	printf("0x1 /* IOPRIO_WHO_PROCESS */, ");
 # else /* XLAT_ABBREV */
-#  if XLAT_VERBOSE
-	printf("ioprio_get(0x1 /* IOPRIO_WHO_PROCESS */, 0) = %s", errstr);
-#  else
-	printf("ioprio_get(IOPRIO_WHO_PROCESS, 0) = %s", errstr);
-#  endif
+	printf("IOPRIO_WHO_PROCESS, ");
+# endif
+	printf("%d%s) = %s", pid, pidns_pid2str(PT_TGID), errstr);
+# if !XLAT_RAW
 	if (rc >= 0) {
 		printf(" (IOPRIO_PRIO_VALUE(");
 		printxval(ioprio_class, (unsigned int) rc >> 13,
 			  "IOPRIO_CLASS_???");
 		printf(", %u))", (unsigned int) rc & 0x1fff);
 	}
-	puts("");
 # endif
+	puts("");
 
-	rc = syscall(__NR_ioprio_set, 2, 0, 8191);
+	rc = syscall(__NR_ioprio_set, 2, pgid, 8191);
 	errstr = sprintrc(rc);
+	pidns_print_leader();
+	printf("ioprio_set(");
 # if XLAT_RAW
-	printf("ioprio_set(%#x, 0, 8191) = %s\n", 2, errstr);
+	printf("%#x", 2);
 # elif XLAT_VERBOSE
-	printf("ioprio_set(%#x /* IOPRIO_WHO_PGRP */, 0, 8191"
-	       " /* IOPRIO_PRIO_VALUE(0 /* IOPRIO_CLASS_NONE */, 8191) */)"
-	       " = %s\n",
-	       2, errstr);
+	printf("%#x /* IOPRIO_WHO_PGRP */", 2);
 # else /* XLAT_ABBREV */
-	printf("ioprio_set(IOPRIO_WHO_PGRP, 0"
-	       ", IOPRIO_PRIO_VALUE(IOPRIO_CLASS_NONE, 8191)) = %s\n",
-	       errstr);
+	printf("IOPRIO_WHO_PGRP");
+# endif
+	printf(", %d%s", pgid, pidns_pid2str(PT_PGID));
+# if XLAT_RAW
+	printf(", 8191)");
+# elif XLAT_VERBOSE
+	printf(", 8191 /* IOPRIO_PRIO_VALUE(0 /* IOPRIO_CLASS_NONE */, 8191) */)");
+# else /* XLAT_ABBREV */
+	printf(", IOPRIO_PRIO_VALUE(IOPRIO_CLASS_NONE, 8191))");
 # endif
+	printf(" = %s\n", errstr);
 
 	rc = syscall(__NR_ioprio_set, bogus_which, bogus_who, bogus_ioprio);
 	errstr = sprintrc(rc);
+	pidns_print_leader();
 # if XLAT_RAW
 	printf("ioprio_set(%#x, %d, %d) = %s\n",
 	       (int) bogus_which, (int) bogus_who, (int) bogus_ioprio,
@@ -104,6 +121,7 @@ main(void)
 	       errstr);
 # endif
 
+	pidns_print_leader();
 	puts("+++ exited with 0 +++");
 
 	return 0;
diff --git a/tests/kcmp-y--pidns-translation.c b/tests/kcmp-y--pidns-translation.c
new file mode 100644
index 00000000..f54d94cc
--- /dev/null
+++ b/tests/kcmp-y--pidns-translation.c
@@ -0,0 +1,2 @@
+#define PIDNS_TRANSLATION
+#include "kcmp-y.c"
diff --git a/tests/kcmp.c b/tests/kcmp.c
index dc5ba9a4..ce705ad0 100644
--- a/tests/kcmp.c
+++ b/tests/kcmp.c
@@ -9,8 +9,8 @@
  */
 
 #include "tests.h"
-
 #include "scno.h"
+#include "pidns.h"
 
 #ifdef __NR_kcmp
 
@@ -101,7 +101,11 @@ do_kcmp(kernel_ulong_t pid1, kernel_ulong_t pid2, kernel_ulong_t type,
 	rc = syscall(__NR_kcmp, pid1, pid2, type, idx1, idx2);
 	errstr = sprintrc(rc);
 
-	printf("kcmp(%d, %d, ", (int) pid1, (int) pid2);
+	const char *pid_str = pidns_pid2str(PT_TGID);
+	pidns_print_leader();
+	printf("kcmp(%d%s, %d%s, ",
+		(int) pid1, (int) pid1 == getpid() ? pid_str : "",
+		(int) pid2, (int) pid2 == getpid() ? pid_str : "");
 
 	if (type_str)
 		printf("%s", type_str);
@@ -146,6 +150,8 @@ do_kcmp(kernel_ulong_t pid1, kernel_ulong_t pid2, kernel_ulong_t type,
 int
 main(void)
 {
+	PIDNS_TEST_INIT;
+
 	static const kernel_ulong_t bogus_pid1 =
 		(kernel_ulong_t) 0xdeadca75face1057ULL;
 	static const kernel_ulong_t bogus_pid2 =
@@ -221,6 +227,7 @@ main(void)
 			(uintptr_t) slot, 1);
 	}
 
+	pidns_print_leader();
 	puts("+++ exited with 0 +++");
 
 	return 0;
diff --git a/tests/kill--pidns-translation.c b/tests/kill--pidns-translation.c
new file mode 100644
index 00000000..4736ca14
--- /dev/null
+++ b/tests/kill--pidns-translation.c
@@ -0,0 +1,2 @@
+#define PIDNS_TRANSLATION
+#include "kill.c"
diff --git a/tests/kill.c b/tests/kill.c
index f7d9341e..17de35da 100644
--- a/tests/kill.c
+++ b/tests/kill.c
@@ -11,6 +11,7 @@
 
 #include "tests.h"
 #include "scno.h"
+#include "pidns.h"
 
 #ifdef __NR_kill
 
@@ -26,6 +27,8 @@ handler(int sig)
 int
 main(void)
 {
+	PIDNS_TEST_INIT;
+
 	const struct sigaction act = { .sa_handler = handler };
 	if (sigaction(SIGALRM, &act, NULL))
 		perror_msg_and_fail("sigaction");
@@ -37,18 +40,23 @@ main(void)
 		perror_msg_and_fail("sigprocmask");
 
 	const int pid = getpid();
+	const char *pid_str = pidns_pid2str(PT_TGID);
 	long rc = syscall(__NR_kill, pid, (long) 0xdefaced00000000ULL | SIGALRM);
-	printf("kill(%d, SIGALRM) = %ld\n", pid, rc);
+	pidns_print_leader();
+	printf("kill(%d%s, SIGALRM) = %ld\n", pid, pid_str, rc);
 
 	const long big_pid = (long) 0xfacefeedbadc0dedULL;
 	const long big_sig = (long) 0xdeadbeefcafef00dULL;
 	rc = syscall(__NR_kill, big_pid, big_sig);
+	pidns_print_leader();
 	printf("kill(%d, %d) = %ld %s (%m)\n",
 	       (int) big_pid, (int) big_sig, rc, errno2name());
 
 	rc = syscall(__NR_kill, (long) 0xdefaced00000000ULL | pid, 0);
-	printf("kill(%d, 0) = %ld\n", pid, rc);
+	pidns_print_leader();
+	printf("kill(%d%s, 0) = %ld\n", pid, pid_str, rc);
 
+	pidns_print_leader();
 	puts("+++ exited with 0 +++");
 	return 0;
 }
diff --git a/tests/migrate_pages--pidns-translation.c b/tests/migrate_pages--pidns-translation.c
new file mode 100644
index 00000000..ec34938d
--- /dev/null
+++ b/tests/migrate_pages--pidns-translation.c
@@ -0,0 +1,2 @@
+#define PIDNS_TRANSLATION
+#include "migrate_pages.c"
diff --git a/tests/migrate_pages.c b/tests/migrate_pages.c
index 2dfba49c..390b490b 100644
--- a/tests/migrate_pages.c
+++ b/tests/migrate_pages.c
@@ -10,6 +10,7 @@
 
 #include "tests.h"
 #include "scno.h"
+#include "pidns.h"
 
 #ifdef __NR_migrate_pages
 
@@ -19,11 +20,21 @@
 int
 main(void)
 {
-	const long pid = (long) 0xfacefeedffffffffULL;
+	PIDNS_TEST_INIT;
+
+	const long pid = (long) 0xfacefeed00000000ULL | getpid();
 	long rc = syscall(__NR_migrate_pages, pid, 0, 0, 0);
-	printf("migrate_pages(%d, 0, NULL, NULL) = %ld %s (%m)\n",
-	       (int) pid, rc, errno2name());
 
+	pidns_print_leader();
+	printf("migrate_pages(%d%s, 0, NULL, NULL) = %ld",
+		(int) pid, pidns_pid2str(PT_TGID), rc);
+
+	if (rc < 0)
+		printf(" %s (%m)\n", errno2name());
+	else
+		printf("\n");
+
+	pidns_print_leader();
 	puts("+++ exited with 0 +++");
 	return 0;
 }
diff --git a/tests/move_pages--pidns-translation.c b/tests/move_pages--pidns-translation.c
new file mode 100644
index 00000000..8498e399
--- /dev/null
+++ b/tests/move_pages--pidns-translation.c
@@ -0,0 +1,2 @@
+#define PIDNS_TRANSLATION
+#include "move_pages.c"
diff --git a/tests/move_pages.c b/tests/move_pages.c
index e00fd1ac..56843158 100644
--- a/tests/move_pages.c
+++ b/tests/move_pages.c
@@ -10,6 +10,7 @@
 
 #include "tests.h"
 #include "scno.h"
+#include "pidns.h"
 
 #ifdef __NR_move_pages
 
@@ -122,15 +123,20 @@ print_status_array(const int *const status, const unsigned long count)
 }
 
 static void
-print_stat_pages(const unsigned long pid, const unsigned long count,
-		 const void **const pages, int *const status)
+print_stat_pages(const unsigned long pid,
+		 const char *pid_str,
+		 const unsigned long count,
+		 const void **const pages,
+		 int *const status)
 {
 	const unsigned long flags = (unsigned long) 0xfacefeed00000002ULL;
 
 	long rc = syscall(__NR_move_pages,
 			  pid, count, pages, NULL, status, flags);
 	const char *errstr = sprintrc(rc);
-	printf("move_pages(%d, %lu, ", (int) pid, count);
+	pidns_print_leader();
+	printf("move_pages(%d%s, %lu, ", (int) pid, pid_str,
+		count);
 	print_page_array(pages, count, 0);
 	printf(", NULL, ");
 	if (rc) {
@@ -152,6 +158,7 @@ print_stat_pages(const unsigned long pid, const unsigned long count,
 
 static void
 print_move_pages(const unsigned long pid,
+		 const char *pid_str,
 		 unsigned long count,
 		 const unsigned int offset,
 		 const void **const pages,
@@ -164,7 +171,9 @@ print_move_pages(const unsigned long pid,
 	long rc = syscall(__NR_move_pages,
 			  pid, count, pages, nodes, status, flags);
 	const char *errstr = sprintrc(rc);
-	printf("move_pages(%d, %lu, ", (int) pid, count);
+	pidns_print_leader();
+	printf("move_pages(%d%s, %lu, ", (int) pid, pid_str,
+		count);
 	print_page_array(pages, count, offset);
 	printf(", ");
 	print_node_array(nodes, count, offset);
@@ -185,8 +194,11 @@ print_move_pages(const unsigned long pid,
 int
 main(void)
 {
+	PIDNS_TEST_INIT;
+
 	const unsigned long pid =
 		(unsigned long) 0xfacefeed00000000ULL | getpid();
+	const char *pid_str = pidns_pid2str(PT_TGID);
 	unsigned long count = 1;
 	const unsigned page_size = get_page_size();
 	const void *const page = tail_alloc(page_size);
@@ -195,40 +207,41 @@ main(void)
 	TAIL_ALLOC_OBJECT_VAR_PTR(int, nodes);
 	TAIL_ALLOC_OBJECT_VAR_PTR(int, status);
 
-	print_stat_pages(pid, 0, pages, status);
-	print_move_pages(pid, 0, 0, pages, nodes, status);
-	print_move_pages(pid, 0, 1, pages + 1, nodes + 1, status + 1);
+	print_stat_pages(pid, pid_str, 0, pages, status);
+	print_move_pages(pid, pid_str, 0, 0, pages, nodes, status);
+	print_move_pages(pid, pid_str, 0, 1, pages + 1, nodes + 1, status + 1);
 
 	*pages = page;
-	print_stat_pages(pid, count, pages, status);
+	print_stat_pages(pid, pid_str, count, pages, status);
 	*nodes = 0xdeadbee1;
-	print_move_pages(pid, count, 0, pages, nodes, status);
-	print_move_pages(pid, count, 1, pages, nodes, status);
+	print_move_pages(pid, pid_str, count, 0, pages, nodes, status);
+	print_move_pages(pid, pid_str, count, 1, pages, nodes, status);
 
 	++count;
 	--status;
 	*(--pages) = efault;
-	print_stat_pages(pid, count, pages, status);
+	print_stat_pages(pid, pid_str, count, pages, status);
 	*(--nodes) = 0xdeadbee2;
-	print_move_pages(pid, count, 0, pages, nodes, status);
-	print_move_pages(pid, count, 1, pages, nodes, status);
+	print_move_pages(pid, pid_str, count, 0, pages, nodes, status);
+	print_move_pages(pid, pid_str, count, 1, pages, nodes, status);
 
 	++count;
 	--status;
 	*(--pages) = nodes;
-	print_stat_pages(pid, count, pages, status);
+	print_stat_pages(pid, pid_str, count, pages, status);
 	*(--nodes) = 0xdeadbee3;
-	print_move_pages(pid, count, 0, pages, nodes, status);
-	print_move_pages(pid, count, 1, pages, nodes, status);
+	print_move_pages(pid, pid_str, count, 0, pages, nodes, status);
+	print_move_pages(pid, pid_str, count, 1, pages, nodes, status);
 
 	++count;
 	--status;
 	*(--pages) = status;
-	print_stat_pages(pid, count, pages, status);
+	print_stat_pages(pid, pid_str, count, pages, status);
 	*(--nodes) = 0xdeadbee4;
-	print_move_pages(pid, count, 0, pages, nodes, status);
-	print_move_pages(pid, count, 1, pages, nodes, status);
+	print_move_pages(pid, pid_str, count, 0, pages, nodes, status);
+	print_move_pages(pid, pid_str, count, 1, pages, nodes, status);
 
+	pidns_print_leader();
 	puts("+++ exited with 0 +++");
 	return 0;
 }
diff --git a/tests/net-sockaddr--pidns-translation.c b/tests/net-sockaddr--pidns-translation.c
new file mode 100644
index 00000000..ff432bf4
--- /dev/null
+++ b/tests/net-sockaddr--pidns-translation.c
@@ -0,0 +1,2 @@
+#define PIDNS_TRANSLATION
+#include "net-sockaddr.c"
diff --git a/tests/net-sockaddr.c b/tests/net-sockaddr.c
index 4fc9da6e..b9cd46fd 100644
--- a/tests/net-sockaddr.c
+++ b/tests/net-sockaddr.c
@@ -9,6 +9,7 @@
  */
 
 #include "tests.h"
+#include "pidns.h"
 #include <stddef.h>
 #include <stdio.h>
 #include <string.h>
@@ -40,18 +41,21 @@ check_un(void)
 	memset(un->sun_path, '0', sizeof(un->sun_path));
 	unsigned int len = sizeof(*un);
 	int ret = connect(-1, (void *) un, len);
+	pidns_print_leader();
 	printf("connect(-1, {sa_family=AF_UNIX, sun_path=\"%.*u\"}"
 	       ", %u) = %d EBADF (%m)\n",
 	       (int) sizeof(un->sun_path), 0, len, ret);
 
 	un->sun_path[1] = 0;
 	ret = connect(-1, (void *) un, len);
+	pidns_print_leader();
 	printf("connect(-1, {sa_family=AF_UNIX, sun_path=\"%u\"}, %u)"
 	       " = %d EBADF (%m)\n", 0, len, ret);
 
 	un->sun_path[0] = 0;
 	un->sun_path[2] = 1;
 	ret = connect(-1, (void *) un, len);
+	pidns_print_leader();
 	printf("connect(-1, {sa_family=AF_UNIX, sun_path=@\"\\0\\001%.*u\"}"
 	       ", %u) = %d EBADF (%m)\n",
 	       (int) sizeof(un->sun_path) - 3, 0, len, ret);
@@ -61,12 +65,14 @@ check_un(void)
 	memset(un->sun_path, '0', sizeof(un->sun_path));
 	len = sizeof(*un) + 2;
 	ret = connect(-1, (void *) un, len);
+	pidns_print_leader();
 	printf("connect(-1, {sa_family=AF_UNIX, sun_path=\"%.*u\"}"
 	       ", %u) = %d EBADF (%m)\n",
 	       (int) sizeof(un->sun_path), 0, len, ret);
 
 	un->sun_path[0] = 0;
 	ret = connect(-1, (void *) un, len);
+	pidns_print_leader();
 	printf("connect(-1, {sa_family=AF_UNIX, sun_path=@\"%.*u\"}"
 	       ", %u) = %d EBADF (%m)\n",
 	       (int) sizeof(un->sun_path) - 1, 0, len, ret);
@@ -75,18 +81,21 @@ check_un(void)
 	un->sun_family = AF_UNIX;
 	len = sizeof(*un) - 2;
 	ret = connect(-1, (void *) un, len);
+	pidns_print_leader();
 	printf("connect(-1, {sa_family=AF_UNIX, sun_path=\"%.*u\"}"
 	       ", %u) = %d EBADF (%m)\n",
 	       (int) sizeof(un->sun_path) - 2, 0, len, ret);
 
 	un->sun_path[0] = 0;
 	ret = connect(-1, (void *) un, len);
+	pidns_print_leader();
 	printf("connect(-1, {sa_family=AF_UNIX, sun_path=@\"%.*u\"}"
 	       ", %u) = %d EBADF (%m)\n",
 	       (int) sizeof(un->sun_path) - 3, 0, len, ret);
 
 	len = sizeof(*un);
 	ret = connect(-1, (void *) un, len);
+	pidns_print_leader();
 	printf("connect(-1, %p, %u) = %d EBADF (%m)\n", un, len, ret);
 
 	un = tail_alloc(sizeof(struct sockaddr_storage));
@@ -94,12 +103,14 @@ check_un(void)
 	memset(un->sun_path, '0', sizeof(un->sun_path));
 	len = sizeof(struct sockaddr_storage) + 1;
 	ret = connect(-1, (void *) un, len);
+	pidns_print_leader();
 	printf("connect(-1, {sa_family=AF_UNIX, sun_path=\"%.*u\"}"
 	       ", %u) = %d EBADF (%m)\n",
 	       (int) sizeof(un->sun_path), 0, len, ret);
 
 	un->sun_path[0] = 0;
 	ret = connect(-1, (void *) un, len);
+	pidns_print_leader();
 	printf("connect(-1, {sa_family=AF_UNIX, sun_path=@\"%.*u\"}"
 	       ", %u) = %d EBADF (%m)\n",
 	       (int) sizeof(un->sun_path) - 1, 0, len, ret);
@@ -117,6 +128,7 @@ check_in(void)
 	in->sin_addr.s_addr = inet_addr(h_addr);
 	unsigned int len = sizeof(*in);
 	int ret = connect(-1, (void *) in, len);
+	pidns_print_leader();
 	printf("connect(-1, {sa_family=AF_INET, sin_port=htons(%hu)"
 	       ", sin_addr=inet_addr(\"%s\")}, %u) = %d EBADF (%m)\n",
 	       h_port, h_addr, len, ret);
@@ -127,6 +139,7 @@ check_in(void)
 	in->sin_addr.s_addr = inet_addr(h_addr);
 	len = sizeof(*in) + 4;
 	ret = connect(-1, (void *) in, len);
+	pidns_print_leader();
 	printf("connect(-1, {sa_family=AF_INET, sin_port=htons(%hu)"
 	       ", sin_addr=inet_addr(\"%s\")}, %u) = %d EBADF (%m)\n",
 	       h_port, h_addr, len, ret);
@@ -137,6 +150,7 @@ check_in(void)
 	in->sin_addr.s_addr = 0;
 	len = sizeof(*in) - 4;
 	ret = connect(-1, (void *) in, len);
+	pidns_print_leader();
 	printf("connect(-1, {sa_family=AF_INET, sa_data=\"%s\"}, %u)"
 	       " = %d EBADF (%m)\n",
 	       "\\0\\0\\0\\0\\0\\0\\377\\377\\377\\377",
@@ -144,6 +158,7 @@ check_in(void)
 
 	len = sizeof(*in);
 	ret = connect(-1, (void *) in, len);
+	pidns_print_leader();
 	printf("connect(-1, %p, %u) = %d EBADF (%m)\n", in, len, ret);
 }
 
@@ -155,6 +170,7 @@ check_in6_linklocal(struct sockaddr_in6 *const in6, const char *const h_addr)
 	in6->sin6_scope_id = 0xfacefeed;
 	unsigned int len = sizeof(*in6);
 	int ret = connect(-1, (void *) in6, len);
+	pidns_print_leader();
 	printf("connect(-1, {sa_family=AF_INET6, sin6_port=htons(%hu)"
 	       ", sin6_flowinfo=htonl(%u)"
 	       ", inet_pton(AF_INET6, \"%s\", &sin6_addr)"
@@ -166,7 +182,8 @@ check_in6_linklocal(struct sockaddr_in6 *const in6, const char *const h_addr)
 	in6->sin6_scope_id = ifindex_lo();
 	if (in6->sin6_scope_id) {
 		ret = connect(-1, (void *) in6, len);
-		printf("connect(-1, {sa_family=AF_INET6, sin6_port=htons(%hu)"
+		pidns_print_leader();
+	printf("connect(-1, {sa_family=AF_INET6, sin6_port=htons(%hu)"
 		       ", sin6_flowinfo=htonl(%u)"
 		       ", inet_pton(AF_INET6, \"%s\", &sin6_addr)"
 		       ", sin6_scope_id=%s}, %u)"
@@ -191,6 +208,7 @@ check_in6(void)
 	in6->sin6_scope_id = 0xfacefeed;
 	unsigned int len = sizeof(*in6);
 	int ret = connect(-1, (void *) in6, len);
+	pidns_print_leader();
 	printf("connect(-1, {sa_family=AF_INET6, sin6_port=htons(%hu)"
 	       ", sin6_flowinfo=htonl(%u)"
 	       ", inet_pton(AF_INET6, \"%s\", &sin6_addr)"
@@ -209,6 +227,7 @@ check_in6(void)
 	in6->sin6_scope_id = 0xfacefeed;
 	len = sizeof(*in6) + 4;
 	ret = connect(-1, (void *) in6, len);
+	pidns_print_leader();
 	printf("connect(-1, {sa_family=AF_INET6, sin6_port=htons(%hu)"
 	       ", sin6_flowinfo=htonl(%u)"
 	       ", inet_pton(AF_INET6, \"%s\", &sin6_addr)"
@@ -223,6 +242,7 @@ check_in6(void)
 	inet_pton(AF_INET6, h_addr, &in6->sin6_addr);
 	len = sizeof(*in6) - sizeof(in6->sin6_scope_id);
 	ret = connect(-1, (void *) in6, len);
+	pidns_print_leader();
 	printf("connect(-1, {sa_family=AF_INET6, sin6_port=htons(%hu)"
 	       ", sin6_flowinfo=htonl(%u)"
 	       ", inet_pton(AF_INET6, \"%s\", &sin6_addr)}, %u)"
@@ -236,6 +256,7 @@ check_in6(void)
 	memset(&in6->sin6_addr, '0', sizeof(in6->sin6_addr) - 4);
 	len = sizeof(*in6) - sizeof(in6->sin6_scope_id) - 4;
 	ret = connect(-1, (void *) in6, len);
+	pidns_print_leader();
 	printf("connect(-1, {sa_family=AF_INET6"
 	       ", sa_data=\"\\0\\0\\0\\0\\0\\000%.*u\"}, %u)"
 	       " = %d EBADF (%m)\n",
@@ -244,6 +265,7 @@ check_in6(void)
 
 	len = sizeof(*in6) - sizeof(in6->sin6_scope_id);
 	ret = connect(-1, (void *) in6, len);
+	pidns_print_leader();
 	printf("connect(-1, %p, %u) = %d EBADF (%m)\n", in6, len, ret);
 }
 
@@ -262,6 +284,7 @@ check_ipx(void)
 	void *ipx = tail_memdup(&c_ipx, sizeof(c_ipx));
 	unsigned int len = sizeof(c_ipx);
 	int ret = connect(-1, ipx, len);
+	pidns_print_leader();
 	printf("connect(-1, {sa_family=AF_IPX, sipx_port=htons(%u)"
 	       ", sipx_network=htonl(%#x)"
 	       ", sipx_node=[%#02x, %#02x, %#02x, %#02x, %#02x, %#02x]"
@@ -316,18 +339,21 @@ check_ax25(void)
 	fill_memory(sax, size);
 	sax->fsa_ax25.sax25_family = AF_AX25;
 	rc = connect(-1, sax_void, sizeof(struct sockaddr_ax25) - 1);
+	pidns_print_leader();
 	printf("connect(-1, {sa_family=AF_AX25, sa_data=\"\\202\\203\\204\\205"
 	       "\\206\\207\\210\\211\\212\\213\\214\\215\\216\"}, %zu) = %s\n",
 	       sizeof(struct sockaddr_ax25) - 1, sprintrc(rc));
 
 	memcpy(sax, &ax25, sizeof(ax25));
 	rc = connect(-1, sax_void, sizeof(struct sockaddr_ax25));
+	pidns_print_leader();
 	printf("connect(-1, {sa_family=AF_AX25, fsa_ax25={sax25_call=VALID-13"
 	       ", sax25_ndigis=8}, fsa_digipeater=[/* ??? */]}, %zu) = %s\n",
 	       sizeof(struct sockaddr_ax25), sprintrc(rc));
 
 	sax->fsa_ax25.sax25_ndigis = 0;
 	rc = connect(-1, sax_void, sizeof(struct sockaddr_ax25));
+	pidns_print_leader();
 	printf("connect(-1, {sa_family=AF_AX25, sax25_call=VALID-13"
 	       ", sax25_ndigis=0}, %zu) = %s\n",
 	       sizeof(struct sockaddr_ax25), sprintrc(rc));
@@ -335,6 +361,7 @@ check_ax25(void)
 	sax->fsa_ax25.sax25_ndigis = 8;
 	size = sizeof(struct sockaddr_ax25) + sizeof(ax25_address) * 3 + 1;
 	rc = connect(-1, sax_void, size);
+	pidns_print_leader();
 	printf("connect(-1, {sa_family=AF_AX25, fsa_ax25={sax25_call=VALID-13"
 	       ", sax25_ndigis=8}, fsa_digipeater"
 	       "=[{ax25_call=\"\\xa6\\xa0\\x82\\x40\\x86\\x8a\\x00\""
@@ -348,6 +375,7 @@ check_ax25(void)
 	sax->fsa_digipeater[2].ax25_call[6] = 0x4;
 	size = sizeof(struct sockaddr_ax25) + sizeof(ax25_address) * 4;
 	rc = connect(-1, sax_void, size);
+	pidns_print_leader();
 	printf("connect(-1, {sa_family=AF_AX25, fsa_ax25={sax25_call=VALID-13"
 	       ", sax25_ndigis=8}, fsa_digipeater"
 	       "=[{ax25_call=\"\\xa6\\xa0\\x82\\x40\\x86\\x8a\\x00\""
@@ -365,7 +393,8 @@ check_ax25(void)
 	for (size_t i = 0; i < 3; i++) {
 		size = sizeof(ax25) + sizeof(ax25_address) * (i / 2);
 		rc = connect(-1, sax_void, size);
-		printf("connect(-1, {sa_family=AF_AX25"
+		pidns_print_leader();
+	printf("connect(-1, {sa_family=AF_AX25"
 		       ", fsa_ax25={sax25_call=VALID-13, sax25_ndigis=%d}"
 		       ", fsa_digipeater=[VALID2-7, OK-15, %s /* FINE-2 */"
 		       ", {ax25_call=\"\\xe6\\xda\\xc2\\xd8\\xd8\\xe6\\x12\""
@@ -427,13 +456,15 @@ check_x25(void)
 	long rc;
 
 	rc = connect(-1, x25_void, sizeof(c_x25) - 1);
+	pidns_print_leader();
 	printf("connect(-1, {sa_family=AF_X25"
 	       ", sa_data=\"0123456789abcde\"}, %zu) = %s\n",
 	       sizeof(c_x25) - 1, sprintrc(rc));
 
 	for (size_t i = 0; i < 2; i++) {
 		rc = connect(-1, x25_void, sizeof(c_x25) + i);
-		printf("connect(-1, {sa_family=AF_X25"
+		pidns_print_leader();
+	printf("connect(-1, {sa_family=AF_X25"
 		       ", sx25_addr={x25_addr=\"0123456789abcde\"...}"
 		       "}, %zu) = %s\n",
 		       sizeof(c_x25) + i, sprintrc(rc));
@@ -442,6 +473,7 @@ check_x25(void)
 	struct sockaddr_x25 *const x25 = x25_void;
 	x25->sx25_addr.x25_addr[10] = '\0';
 	rc = connect(-1, x25_void, sizeof(c_x25));
+	pidns_print_leader();
 	printf("connect(-1, {sa_family=AF_X25"
 	       ", sx25_addr={x25_addr=\"0123456789\"}"
 	       "}, %zu) = %s\n",
@@ -457,19 +489,21 @@ check_nl(void)
 	nl->nl_groups = 0xfacefeed;
 	unsigned int len = sizeof(*nl);
 	int ret = connect(-1, (void *) nl, len);
+	pidns_print_leader();
 	printf("connect(-1, {sa_family=AF_NETLINK, nl_pid=%d"
 	       ", nl_groups=%#08x}, %u) = %d EBADF (%m)\n",
 	       nl->nl_pid, nl->nl_groups, len, ret);
 
 	nl = ((void *) nl) - 4;
 	nl->nl_family = AF_NETLINK;
-	nl->nl_pid = 1234567890;
+	nl->nl_pid = getpid();
 	nl->nl_groups = 0xfacefeed;
 	len = sizeof(*nl) + 4;
 	ret = connect(-1, (void *) nl, len);
-	printf("connect(-1, {sa_family=AF_NETLINK, nl_pid=%d"
+	pidns_print_leader();
+	printf("connect(-1, {sa_family=AF_NETLINK, nl_pid=%d%s"
 	       ", nl_groups=%#08x}, %u) = %d EBADF (%m)\n",
-	       nl->nl_pid, nl->nl_groups, len, ret);
+	       nl->nl_pid, pidns_pid2str(PT_TGID), nl->nl_groups, len, ret);
 }
 
 static void
@@ -487,6 +521,7 @@ check_ll(void)
 	void *ll = tail_memdup(&c_ll, sizeof(c_ll));
 	unsigned int len = sizeof(c_ll);
 	int ret = connect(-1, ll, len);
+	pidns_print_leader();
 	printf("connect(-1, {sa_family=AF_PACKET"
 	       ", sll_protocol=htons(ETH_P_ALL)"
 	       ", sll_ifindex=%u, sll_hatype=ARPHRD_ETHER"
@@ -502,6 +537,7 @@ check_ll(void)
 
 	((struct sockaddr_ll *) ll)->sll_halen++;
 	ret = connect(-1, ll, len);
+	pidns_print_leader();
 	printf("connect(-1, {sa_family=AF_PACKET"
 	       ", sll_protocol=htons(ETH_P_ALL)"
 	       ", sll_ifindex=%u, sll_hatype=ARPHRD_ETHER"
@@ -517,6 +553,7 @@ check_ll(void)
 
 	((struct sockaddr_ll *) ll)->sll_halen = 0;
 	ret = connect(-1, ll, len);
+	pidns_print_leader();
 	printf("connect(-1, {sa_family=AF_PACKET"
 	       ", sll_protocol=htons(ETH_P_ALL)"
 	       ", sll_ifindex=%u, sll_hatype=ARPHRD_ETHER"
@@ -526,7 +563,8 @@ check_ll(void)
 	((struct sockaddr_ll *) ll)->sll_ifindex = ifindex_lo();
 	if (((struct sockaddr_ll *) ll)->sll_ifindex) {
 		ret = connect(-1, ll, len);
-		printf("connect(-1, {sa_family=AF_PACKET"
+	pidns_print_leader();
+	printf("connect(-1, {sa_family=AF_PACKET"
 		       ", sll_protocol=htons(ETH_P_ALL)"
 		       ", sll_ifindex=%s"
 		       ", sll_hatype=ARPHRD_ETHER"
@@ -549,11 +587,13 @@ check_hci(void)
 	unsigned int len = sizeof(*hci);
 
 	int ret = connect(-1, (void *) hci, 4);
+	pidns_print_leader();
 	printf("connect(-1, {sa_family=AF_BLUETOOTH, hci_dev=htobs(%hu)"
 	       "}, 4) = %d EBADF (%m)\n",
 	       h_port, ret);
 
 	ret = connect(-1, (void *) hci, len);
+	pidns_print_leader();
 	printf("connect(-1, {sa_family=AF_BLUETOOTH, hci_dev=htobs(%hu)"
 # ifdef HAVE_STRUCT_SOCKADDR_HCI_HCI_CHANNEL
 	       ", hci_channel=HCI_CHANNEL_RAW"
@@ -572,6 +612,7 @@ check_sco(void)
 	void *sco = tail_memdup(&c_sco, sizeof(c_sco));
 	unsigned int len = sizeof(c_sco);
 	int ret = connect(-1, sco, len);
+	pidns_print_leader();
 	printf("connect(-1, {sa_family=AF_BLUETOOTH"
 	       ", sco_bdaddr=%02x:%02x:%02x:%02x:%02x:%02x"
 	       "}, %u) = %d EBADF (%m)\n",
@@ -592,6 +633,7 @@ check_rc(void)
 	void *rc = tail_memdup(&c_rc, sizeof(c_rc));
 	unsigned int len = sizeof(c_rc);
 	int ret = connect(-1, rc, len);
+	pidns_print_leader();
 	printf("connect(-1, {sa_family=AF_BLUETOOTH"
 	       ", rc_bdaddr=%02x:%02x:%02x:%02x:%02x:%02x"
 	       ", rc_channel=%u}, %u) = %d EBADF (%m)\n",
@@ -619,6 +661,7 @@ check_l2(void)
 	unsigned int len = sizeof(c_l2);
 
 	int ret = connect(-1, l2, len);
+	pidns_print_leader();
 	printf("connect(-1, {sa_family=AF_BLUETOOTH"
 	       ", l2_psm=htobs(L2CAP_PSM_DYN_START + %hu)"
 	       ", l2_bdaddr=%02x:%02x:%02x:%02x:%02x:%02x"
@@ -640,6 +683,7 @@ check_l2(void)
 # endif
 	memcpy(l2, &c_l2, sizeof(c_l2));
 	ret = connect(-1, l2, len);
+	pidns_print_leader();
 	printf("connect(-1, {sa_family=AF_BLUETOOTH"
 	       ", l2_psm=htobs(L2CAP_PSM_SDP)"
 	       ", l2_bdaddr=%02x:%02x:%02x:%02x:%02x:%02x"
@@ -660,6 +704,7 @@ check_l2(void)
 # endif
 	memcpy(l2, &c_l2, sizeof(c_l2));
 	ret = connect(-1, l2, len);
+	pidns_print_leader();
 	printf("connect(-1, {sa_family=AF_BLUETOOTH"
 	       ", l2_psm=htobs(0xbad /* L2CAP_PSM_??? */)"
 	       ", l2_bdaddr=%02x:%02x:%02x:%02x:%02x:%02x"
@@ -677,6 +722,7 @@ check_l2(void)
 	c_l2.l2_cid = htobs(0xffff);
 	memcpy(l2, &c_l2, 12);
 	ret = connect(-1, l2, 12);
+	pidns_print_leader();
 	printf("connect(-1, {sa_family=AF_BLUETOOTH"
 	       ", l2_psm=htobs(L2CAP_PSM_AUTO_END)"
 	       ", l2_bdaddr=%02x:%02x:%02x:%02x:%02x:%02x"
@@ -700,6 +746,7 @@ check_raw(void)
 	u.sa->sa_family = 0xff;
 	unsigned int len = sizeof(*u.st) + 8;
 	int ret = connect(-1, (void *) u.st, len);
+	pidns_print_leader();
 	printf("connect(-1, {sa_family=%#x /* AF_??? */, sa_data=\"%.*u\"}"
 	       ", %u) = %d EBADF (%m)\n", u.sa->sa_family,
 	       (int) (sizeof(*u.st) - sizeof(u.sa->sa_family)), 0, len, ret);
@@ -707,11 +754,13 @@ check_raw(void)
 	u.sa->sa_family = 0;
 	len = sizeof(u.sa->sa_family) + 1;
 	ret = connect(-1, (void *) u.st, len);
+	pidns_print_leader();
 	printf("connect(-1, {sa_family=AF_UNSPEC, sa_data=\"0\"}, %u)"
 	       " = %d EBADF (%m)\n", len, ret);
 
 	u.sa->sa_family = AF_BLUETOOTH;
 	ret = connect(-1, (void *) u.st, len);
+	pidns_print_leader();
 	printf("connect(-1, {sa_family=AF_BLUETOOTH, sa_data=\"0\"}, %u)"
 	       " = %d EBADF (%m)\n", len, ret);
 }
@@ -719,6 +768,8 @@ check_raw(void)
 int
 main(void)
 {
+	PIDNS_TEST_INIT;
+
 	check_un();
 	check_in();
 	check_in6();
@@ -735,6 +786,7 @@ main(void)
 #endif
 	check_raw();
 
+	pidns_print_leader();
 	puts("+++ exited with 0 +++");
 	return 0;
 }
diff --git a/tests/netlink_audit--pidns-translation.c b/tests/netlink_audit--pidns-translation.c
new file mode 100644
index 00000000..e08f9168
--- /dev/null
+++ b/tests/netlink_audit--pidns-translation.c
@@ -0,0 +1,2 @@
+#define PIDNS_TRANSLATION
+#include "netlink_audit.c"
diff --git a/tests/netlink_audit--pidns-translation.test b/tests/netlink_audit--pidns-translation.test
new file mode 100755
index 00000000..fbc32435
--- /dev/null
+++ b/tests/netlink_audit--pidns-translation.test
@@ -0,0 +1,13 @@
+#!/bin/sh
+#
+# Check decoding of NETLINK_SOCK_DIAG protocol
+#
+# Copyright (c) 2020 The strace developers.
+# All rights reserved.
+#
+# SPDX-License-Identifier: LGPL-2.1-or-later
+
+. "${srcdir=.}/init.sh"
+
+run_prog ../netlink_netlink_diag
+test_pidns -e trace=sendto "$@"
diff --git a/tests/netlink_audit.c b/tests/netlink_audit.c
index eba609a1..5dfcd786 100644
--- a/tests/netlink_audit.c
+++ b/tests/netlink_audit.c
@@ -7,6 +7,7 @@
  */
 
 #include "tests.h"
+#include "pidns.h"
 #include <stdio.h>
 #include <string.h>
 #include <unistd.h>
@@ -17,18 +18,23 @@
 static void
 test_nlmsg_type(const int fd)
 {
+	PIDNS_TEST_INIT;
+
 	long rc;
 	struct nlmsghdr nlh = {
 		.nlmsg_len = sizeof(nlh),
 		.nlmsg_type = AUDIT_GET,
 		.nlmsg_flags = NLM_F_REQUEST,
+		.nlmsg_pid = getpid(),
 	};
 
 	rc = sendto(fd, &nlh, sizeof(nlh), MSG_DONTWAIT, NULL, 0);
+	pidns_print_leader();
 	printf("sendto(%d, {len=%u, type=AUDIT_GET"
-	       ", flags=NLM_F_REQUEST, seq=0, pid=0}"
+	       ", flags=NLM_F_REQUEST, seq=0, pid=%d%s}"
 	       ", %u, MSG_DONTWAIT, NULL, 0) = %s\n",
-	       fd, nlh.nlmsg_len, (unsigned) sizeof(nlh), sprintrc(rc));
+	       fd, nlh.nlmsg_len, nlh.nlmsg_pid, pidns_pid2str(PT_TGID),
+	       (unsigned) sizeof(nlh), sprintrc(rc));
 }
 
 int main(void)
@@ -39,6 +45,7 @@ int main(void)
 
 	test_nlmsg_type(fd);
 
+	pidns_print_leader();
 	printf("+++ exited with 0 +++\n");
 
 	return 0;
diff --git a/tests/pidfd_open--pidns-translation.c b/tests/pidfd_open--pidns-translation.c
new file mode 100644
index 00000000..c38e37a8
--- /dev/null
+++ b/tests/pidfd_open--pidns-translation.c
@@ -0,0 +1,2 @@
+#define PIDNS_TRANSLATION
+#include "pidfd_open.c"
diff --git a/tests/pidfd_open.c b/tests/pidfd_open.c
index 5860adde..e5d74a91 100644
--- a/tests/pidfd_open.c
+++ b/tests/pidfd_open.c
@@ -10,6 +10,7 @@
 
 #include "tests.h"
 #include "scno.h"
+#include "pidns.h"
 
 #ifdef __NR_pidfd_open
 
@@ -37,6 +38,8 @@ k_pidfd_open(const unsigned int pid, const unsigned int flags)
 int
 main(void)
 {
+	PIDNS_TEST_INIT;
+
 # if defined PATH_TRACING || defined PRINT_PATHS
 	skip_if_unavailable("/proc/self/fd/");
 # endif
@@ -50,16 +53,19 @@ main(void)
 
 	k_pidfd_open(0, 0);
 # ifndef PATH_TRACING
+	pidns_print_leader();
 	printf("pidfd_open(0, 0) = %s\n", errstr);
 # endif
 
 	k_pidfd_open(-1U, 0);
 # ifndef PATH_TRACING
+	pidns_print_leader();
 	printf("pidfd_open(-1, 0) = %s\n", errstr);
 # endif
 
 	k_pidfd_open(0, -1U);
 # ifndef PATH_TRACING
+	pidns_print_leader();
 	printf("pidfd_open(0, %#x) = %s\n", -1U, errstr);
 # endif
 
@@ -68,7 +74,10 @@ main(void)
 
 	k_pidfd_open(pid, flags);
 # ifndef PATH_TRACING
-	printf("pidfd_open(%d, %#x) = %s\n", pid, flags, errstr);
+	const char *pid_str = pidns_pid2str(PT_TGID);
+	pidns_print_leader();
+	printf("pidfd_open(%d%s, %#x) = %s\n",
+		pid, pid_str, flags, errstr);
 # endif
 
 # ifdef PRINT_PATHS
@@ -80,17 +89,19 @@ main(void)
 # endif
 
 # ifndef PATH_TRACING
-	printf("pidfd_open(%d, 0) = "
+	pidns_print_leader();
+	printf("pidfd_open(%d%s, 0) = "
 #  if defined PRINT_PIDFD
-	       "%ld<pid:%d>\n", pid, rc, pid
+	       "%ld<pid:%d>\n", pid, pid_str, rc, pid
 #  elif defined PRINT_PATHS
-	       "%ld<anon_inode:[pidfd]>\n", pid, rc
+	       "%ld<anon_inode:[pidfd]>\n", pid, pid_str, rc
 #  else
-	       "%s\n", pid, errstr
+	       "%s\n", pid, pid_str, errstr
 #  endif
 	       );
 # endif
 
+	pidns_print_leader();
 	puts("+++ exited with 0 +++");
 	return 0;
 }
diff --git a/tests/pidfd_send_signal--pidns-translation.c b/tests/pidfd_send_signal--pidns-translation.c
new file mode 100644
index 00000000..b04f10f5
--- /dev/null
+++ b/tests/pidfd_send_signal--pidns-translation.c
@@ -0,0 +1,2 @@
+#define PIDNS_TRANSLATION
+#include "pidfd_send_signal.c"
diff --git a/tests/pidfd_send_signal.c b/tests/pidfd_send_signal.c
index 8537a497..3ce5024f 100644
--- a/tests/pidfd_send_signal.c
+++ b/tests/pidfd_send_signal.c
@@ -10,6 +10,7 @@
 #include "tests.h"
 #include <unistd.h>
 #include "scno.h"
+#include "pidns.h"
 
 #ifdef __NR_pidfd_send_signal
 
@@ -36,6 +37,8 @@ sys_pidfd_send_signal(int pidfd, int sig, const void *info, int flags)
 int
 main(void)
 {
+	PIDNS_TEST_INIT;
+
 	static const char null_path[] = "/dev/null";
 
 	int fd = open(null_path, O_RDONLY);
@@ -46,19 +49,23 @@ main(void)
 	const void *esi = (const void *) si + 1;
 
 	sys_pidfd_send_signal(fd, SIGUSR1, esi, 0);
+	pidns_print_leader();
 	printf("pidfd_send_signal(%d, SIGUSR1, %p, 0) = %s\n",
 	       fd, esi, errstr);
 
 	si->si_signo = SIGUSR1;
 	si->si_code = SI_QUEUE;
+	si->si_pid = getpid();
 
 	sys_pidfd_send_signal(fd, SIGUSR2, si, -1);
+	pidns_print_leader();
 	printf("pidfd_send_signal(%d, SIGUSR2, {si_signo=SIGUSR1"
-	       ", si_code=SI_QUEUE, si_errno=%u, si_pid=%d, si_uid=%d"
+	       ", si_code=SI_QUEUE, si_errno=%u, si_pid=%d%s, si_uid=%d"
 	       ", si_value={int=%d, ptr=%p}}, %#x) = %s\n",
-	       fd, si->si_errno, si->si_pid, si->si_uid, si->si_int, si->si_ptr,
-	       -1U, errstr);
+	       fd, si->si_errno, si->si_pid, pidns_pid2str(PT_TGID), si->si_uid,
+	       si->si_int, si->si_ptr, -1U, errstr);
 
+	pidns_print_leader();
 	puts("+++ exited with 0 +++");
 	return 0;
 }
diff --git a/tests/prlimit64--pidns-translation.c b/tests/prlimit64--pidns-translation.c
new file mode 100644
index 00000000..3972de66
--- /dev/null
+++ b/tests/prlimit64--pidns-translation.c
@@ -0,0 +1,2 @@
+#define PIDNS_TRANSLATION
+#include "prlimit64.c"
diff --git a/tests/prlimit64.c b/tests/prlimit64.c
index 34201a2b..bc1a80b3 100644
--- a/tests/prlimit64.c
+++ b/tests/prlimit64.c
@@ -19,6 +19,7 @@
 # include <sys/resource.h>
 # include <unistd.h>
 
+# include "pidns.h"
 # include "xlat.h"
 # include "xlat/resources.h"
 
@@ -42,8 +43,11 @@ sprint_rlim(uint64_t lim)
 int
 main(void)
 {
+	PIDNS_TEST_INIT;
+
 	unsigned long pid =
 		(unsigned long) 0xdefaced00000000ULL | (unsigned) getpid();
+	const char *pid_str = pidns_pid2str(PT_TGID);
 	uint64_t *const rlimit = tail_alloc(sizeof(*rlimit) * 2);
 	const struct xlat_data *xlat;
 	size_t i = 0;
@@ -54,18 +58,23 @@ main(void)
 
 		unsigned long res = 0xfacefeed00000000ULL | xlat->val;
 		long rc = syscall(__NR_prlimit64, pid, res, 0, rlimit);
+		pidns_print_leader();
 		if (rc)
-			printf("prlimit64(%d, %s, NULL, %p) = %ld %s (%m)\n",
-			       (unsigned) pid, xlat->str, rlimit,
+			printf("prlimit64(%d%s, %s, NULL, %p) ="
+				     " %ld %s (%m)\n",
+			       (unsigned) pid, pid_str,
+			       xlat->str, rlimit,
 			       rc, errno2name());
 		else
-			printf("prlimit64(%d, %s, NULL"
+			printf("prlimit64(%d%s, %s, NULL"
 			       ", {rlim_cur=%s, rlim_max=%s}) = 0\n",
-			       (unsigned) pid, xlat->str,
+			       (unsigned) pid, pid_str,
+			       xlat->str,
 			       sprint_rlim(rlimit[0]),
 			       sprint_rlim(rlimit[1]));
 	}
 
+	pidns_print_leader();
 	puts("+++ exited with 0 +++");
 	return 0;
 }
diff --git a/tests/process_vm_readv--pidns-translation.c b/tests/process_vm_readv--pidns-translation.c
new file mode 100644
index 00000000..0db29ca2
--- /dev/null
+++ b/tests/process_vm_readv--pidns-translation.c
@@ -0,0 +1,2 @@
+#define PIDNS_TRANSLATION
+#include "process_vm_readv.c"
diff --git a/tests/process_vm_readv_writev.c b/tests/process_vm_readv_writev.c
index 9309135a..44e511dd 100644
--- a/tests/process_vm_readv_writev.c
+++ b/tests/process_vm_readv_writev.c
@@ -12,6 +12,7 @@
 #include <stdio.h>
 #include <unistd.h>
 #include <sys/uio.h>
+#include "pidns.h"
 
 #if OP_WR
 # define in_iovec  rmt_iovec
@@ -121,7 +122,7 @@ print_iov(const struct iovec *iov, const void *arg_ptr, long rc)
 }
 
 static void
-do_call(kernel_ulong_t pid,
+do_call(kernel_ulong_t pid, enum pid_type pid_type,
 	kernel_ulong_t local_iov, const char *local_arg,
 	kernel_ulong_t liovcnt,
 	kernel_ulong_t remote_iov, const char *remote_arg,
@@ -135,7 +136,8 @@ do_call(kernel_ulong_t pid,
 		flags);
 	errstr = sprintrc(rc);
 
-	printf("%s(%d, ", OP_STR, (int) pid);
+	pidns_print_leader();
+	printf("%s(%d%s, ", OP_STR, (int) pid, pidns_pid2str(pid_type));
 
 	if (pr_iov)
 		pr_iov((const struct iovec *) (uintptr_t) local_iov, local_arg,
@@ -164,6 +166,8 @@ ptr_cast(void *ptr)
 int
 main(void)
 {
+	PIDNS_TEST_INIT;
+
 	enum {
 		SIZE_11 = 2,
 		SIZE_12 = 3,
@@ -243,18 +247,18 @@ main(void)
 	fill_memory_ex(data2_out, SIZE_2, SEGM2_BASE, SIZE_2);
 
 
-	do_call(bogus_pid, (kernel_ulong_t) (uintptr_t) ARG_STR(NULL),
+	do_call(bogus_pid, PT_NONE, (kernel_ulong_t) (uintptr_t) ARG_STR(NULL),
 		bogus_iovcnt1, (kernel_ulong_t) (uintptr_t) ARG_STR(NULL),
 		bogus_iovcnt2, bogus_flags, NULL);
 
-	do_call(my_pid, ptr_cast(bogus_iov + ARRAY_SIZE(bogus_iovec)),
+	do_call(my_pid, PT_TGID, ptr_cast(bogus_iov + ARRAY_SIZE(bogus_iovec)),
 		"[]", 0, ptr_cast(in_iov + ARRAY_SIZE(in_iovec)), "[]",
 		0, 0, NULL);
-	do_call(my_pid, ptr_cast(bogus_iov + ARRAY_SIZE(bogus_iovec)), NULL,
-		bogus_iovcnt1, ptr_cast(in_iov + ARRAY_SIZE(in_iovec)), NULL,
-		bogus_iovcnt2, 0, print_iov);
+	do_call(my_pid, PT_TGID, ptr_cast(bogus_iov + ARRAY_SIZE(bogus_iovec)),
+		NULL, bogus_iovcnt1, ptr_cast(in_iov + ARRAY_SIZE(in_iovec)),
+		NULL, bogus_iovcnt2, 0, print_iov);
 
-	do_call(my_pid, ptr_cast(bogus_iov), (char *) &bogus_arg,
+	do_call(my_pid, PT_TGID, ptr_cast(bogus_iov), (char *) &bogus_arg,
 		ARRAY_SIZE(bogus_iovec), ptr_cast(rmt_iov + 2),
 		(char *) &rmt_arg_cut, ARRAY_SIZE(rmt_iovec) - 2, 0, print_iov);
 
@@ -263,7 +267,7 @@ main(void)
 	lcl_arg_cut.check_rc = 1;
 #endif
 
-	do_call(my_pid, ptr_cast(lcl_iov + 2), (char *) &lcl_arg_cut,
+	do_call(my_pid, PT_TGID, ptr_cast(lcl_iov + 2), (char *) &lcl_arg_cut,
 		ARRAY_SIZE(lcl_iovec) - 1, ptr_cast(bogus_iov + 2),
 		(char *) &bogus_arg_cut, ARRAY_SIZE(bogus_iovec) - 1, 0,
 		print_iov);
@@ -273,15 +277,16 @@ main(void)
 	rmt_arg_cut.addr_term = 1;
 	rmt_arg_cut.count = 5;
 
-	do_call(my_pid, ptr_cast(lcl_iov + 2), (char *) &lcl_arg_cut,
+	do_call(my_pid, PT_TGID, ptr_cast(lcl_iov + 2), (char *) &lcl_arg_cut,
 		ARRAY_SIZE(lcl_iovec) - 2, ptr_cast(rmt_iov + 1),
 		(char *) &rmt_arg_cut, ARRAY_SIZE(rmt_iovec), 0, print_iov);
 
 	/* Correct call */
-	do_call(my_pid, ptr_cast(lcl_iov), (char *) &lcl_arg,
+	do_call(my_pid, PT_TGID, ptr_cast(lcl_iov), (char *) &lcl_arg,
 		ARRAY_SIZE(lcl_iovec), ptr_cast(rmt_iov), (char *) &rmt_arg,
 		ARRAY_SIZE(rmt_iovec), 0, print_iov);
 
+	pidns_print_leader();
 	puts("+++ exited with 0 +++");
 
 	return 0;
diff --git a/tests/process_vm_writev--pidns-translation.c b/tests/process_vm_writev--pidns-translation.c
new file mode 100644
index 00000000..9ba6a39b
--- /dev/null
+++ b/tests/process_vm_writev--pidns-translation.c
@@ -0,0 +1,2 @@
+#define PIDNS_TRANSLATION
+#include "process_vm_writev.c"
diff --git a/tests/rt_sigqueueinfo--pidns-translation.c b/tests/rt_sigqueueinfo--pidns-translation.c
new file mode 100644
index 00000000..74bfb464
--- /dev/null
+++ b/tests/rt_sigqueueinfo--pidns-translation.c
@@ -0,0 +1,2 @@
+#define PIDNS_TRANSLATION
+#include "rt_sigqueueinfo.c"
diff --git a/tests/rt_sigqueueinfo.c b/tests/rt_sigqueueinfo.c
index 3d3ae52c..7189ef14 100644
--- a/tests/rt_sigqueueinfo.c
+++ b/tests/rt_sigqueueinfo.c
@@ -7,6 +7,7 @@
  */
 
 #include "tests.h"
+#include "pidns.h"
 #include <assert.h>
 #include <stdio.h>
 #include <signal.h>
@@ -15,6 +16,8 @@
 int
 main(void)
 {
+	PIDNS_TEST_INIT;
+
 	struct sigaction sa = {
 		.sa_handler = SIG_IGN
 	};
@@ -22,15 +25,19 @@ main(void)
 		.sival_ptr = (void *) (unsigned long) 0xdeadbeefbadc0dedULL
 	};
 	pid_t pid = getpid();
+	const char *pid_str = pidns_pid2str(PT_TGID);
 
 	assert(sigaction(SIGUSR1, &sa, NULL) == 0);
 	if (sigqueue(pid, SIGUSR1, value))
 		perror_msg_and_skip("sigqueue");
-	printf("rt_sigqueueinfo(%u, SIGUSR1, {si_signo=SIGUSR1, "
-		"si_code=SI_QUEUE, si_pid=%d, si_uid=%d, "
+	pidns_print_leader();
+	printf("rt_sigqueueinfo(%d%s, SIGUSR1, {si_signo=SIGUSR1, "
+		"si_code=SI_QUEUE, si_pid=%d%s, si_uid=%u, "
 		"si_value={int=%d, ptr=%p}}) = 0\n",
-		pid, pid, getuid(), value.sival_int, value.sival_ptr);
-	printf("+++ exited with 0 +++\n");
+		pid, pid_str, pid, pid_str,
+		getuid(), value.sival_int, value.sival_ptr);
+	pidns_print_leader();
+	puts("+++ exited with 0 +++");
 
 	return 0;
 }
diff --git a/tests/rt_tgsigqueueinfo--pidns-translation.c b/tests/rt_tgsigqueueinfo--pidns-translation.c
new file mode 100644
index 00000000..94396f00
--- /dev/null
+++ b/tests/rt_tgsigqueueinfo--pidns-translation.c
@@ -0,0 +1,2 @@
+#define PIDNS_TRANSLATION
+#include "rt_tgsigqueueinfo.c"
diff --git a/tests/rt_tgsigqueueinfo.c b/tests/rt_tgsigqueueinfo.c
index 918e41d0..dcd7b161 100644
--- a/tests/rt_tgsigqueueinfo.c
+++ b/tests/rt_tgsigqueueinfo.c
@@ -10,8 +10,9 @@
 
 #include "tests.h"
 #include "scno.h"
+#include "pidns.h"
 
-#ifdef __NR_rt_tgsigqueueinfo
+#if defined __NR_rt_tgsigqueueinfo && defined __NR_gettid
 
 # include <errno.h>
 # include <signal.h>
@@ -20,11 +21,11 @@
 # include <unistd.h>
 
 static long
-k_tgsigqueueinfo(const pid_t pid, const int sig, const void *const info)
+k_tgsigqueueinfo(const pid_t tgid, const int tid, const int sig, const void *const info)
 {
 	return syscall(__NR_rt_tgsigqueueinfo,
-		       F8ILL_KULONG_MASK | pid,
-		       F8ILL_KULONG_MASK | pid,
+		       F8ILL_KULONG_MASK | tgid,
+		       F8ILL_KULONG_MASK | tid,
 		       F8ILL_KULONG_MASK | sig,
 		       info);
 }
@@ -32,6 +33,8 @@ k_tgsigqueueinfo(const pid_t pid, const int sig, const void *const info)
 int
 main(void)
 {
+	PIDNS_TEST_INIT;
+
 	const struct sigaction sa = {
 		.sa_handler = SIG_IGN
 	};
@@ -48,17 +51,22 @@ main(void)
 	info->si_value.sival_ptr =
 		(void *) (unsigned long) 0xdeadbeeffacefeedULL;
 
-	if (k_tgsigqueueinfo(info->si_pid, SIGUSR1, info))
+	if (k_tgsigqueueinfo(getpid(), syscall(__NR_gettid), SIGUSR1, info))
 		(errno == ENOSYS ? perror_msg_and_skip : perror_msg_and_fail)(
 			"rt_tgsigqueueinfo");
 
-	printf("rt_tgsigqueueinfo(%u, %u, %s, {si_signo=%s"
-		", si_code=SI_QUEUE, si_errno=ENOENT, si_pid=%d"
+	pidns_print_leader();
+	printf("rt_tgsigqueueinfo(%d%s, %d%s, %s, {si_signo=%s"
+		", si_code=SI_QUEUE, si_errno=ENOENT, si_pid=%d%s"
 		", si_uid=%d, si_value={int=%d, ptr=%p}}) = 0\n",
-		info->si_pid, info->si_pid, "SIGUSR1", "SIGUSR1",
-		info->si_pid, info->si_uid, info->si_value.sival_int,
+		info->si_pid, pidns_pid2str(PT_TGID),
+		info->si_pid, pidns_pid2str(PT_TID),
+		"SIGUSR1", "SIGUSR1",
+		info->si_pid, pidns_pid2str(PT_TGID),
+		info->si_uid, info->si_value.sival_int,
 		info->si_value.sival_ptr);
 
+	pidns_print_leader();
 	puts("+++ exited with 0 +++");
 	return 0;
 }
diff --git a/tests/sched_xetaffinity--pidns-translation.c b/tests/sched_xetaffinity--pidns-translation.c
new file mode 100644
index 00000000..814e3989
--- /dev/null
+++ b/tests/sched_xetaffinity--pidns-translation.c
@@ -0,0 +1,2 @@
+#define PIDNS_TRANSLATION
+#include "sched_xetaffinity.c"
diff --git a/tests/sched_xetaffinity.c b/tests/sched_xetaffinity.c
index cebff3ab..2e508ca3 100644
--- a/tests/sched_xetaffinity.c
+++ b/tests/sched_xetaffinity.c
@@ -10,6 +10,7 @@
 
 #include "tests.h"
 #include "scno.h"
+#include "pidns.h"
 #include <sched.h>
 
 #if defined __NR_sched_getaffinity && defined __NR_sched_setaffinity \
@@ -41,8 +42,11 @@ setaffinity(unsigned long pid, unsigned long size, void *set)
 int
 main(void)
 {
+	PIDNS_TEST_INIT;
+
 	unsigned int cpuset_size = 1;
 	const pid_t pid = getpid();
+	const char *pid_str = pidns_pid2str(PT_TGID);
 
 	while (cpuset_size) {
 		assert(getaffinity(pid, cpuset_size, NULL) == -1);
@@ -50,18 +54,21 @@ main(void)
 			break;
 		if (EINVAL != errno)
 			perror_msg_and_skip("sched_getaffinity");
-		printf("sched_getaffinity(%d, %u, NULL) = %s\n",
-		       pid, cpuset_size, errstr);
+		pidns_print_leader();
+		printf("sched_getaffinity(%d%s, %u, NULL) = %s\n",
+		       pid, pid_str, cpuset_size, errstr);
 		cpuset_size <<= 1;
 	}
 	assert(cpuset_size);
-	printf("sched_getaffinity(%d, %u, NULL) = %s\n",
-	       pid, cpuset_size, errstr);
+	pidns_print_leader();
+	printf("sched_getaffinity(%d%s, %u, NULL) = %s\n",
+	       pid, pid_str, cpuset_size, errstr);
 
 	cpu_set_t *cpuset = tail_alloc(cpuset_size);
 	getaffinity(pid, cpuset_size, cpuset + 1);
-	printf("sched_getaffinity(%d, %u, %p) = %s\n",
-	       pid, cpuset_size, cpuset + 1, errstr);
+	pidns_print_leader();
+	printf("sched_getaffinity(%d%s, %u, %p) = %s\n",
+	       pid, pid_str, cpuset_size, cpuset + 1, errstr);
 
 	int ret_size = getaffinity(pid, cpuset_size, cpuset);
 	if (ret_size < 0)
@@ -69,7 +76,8 @@ main(void)
 				    pid, (unsigned) cpuset_size, cpuset, errstr);
 	assert(ret_size <= (int) cpuset_size);
 
-	printf("sched_getaffinity(%d, %u, [", pid, cpuset_size);
+	pidns_print_leader();
+	printf("sched_getaffinity(%d%s, %u, [", pid, pid_str, cpuset_size);
 	const char *sep;
 	unsigned int i, cpu;
 	for (i = 0, cpu = 0, sep = ""; i < (unsigned) ret_size * 8; ++i) {
@@ -85,8 +93,9 @@ main(void)
 	CPU_SET_S(cpu, cpuset_size, cpuset);
 	if (setaffinity(pid, cpuset_size, cpuset))
 		perror_msg_and_skip("sched_setaffinity");
-	printf("sched_setaffinity(%d, %u, [%u]) = 0\n",
-	       pid, cpuset_size, cpu);
+	pidns_print_leader();
+	printf("sched_setaffinity(%d%s, %u, [%u]) = 0\n",
+	       pid, pid_str, cpuset_size, cpu);
 
 	const unsigned int big_size = cpuset_size < 128 ? 128 : cpuset_size * 2;
 	cpuset = tail_alloc(big_size);
@@ -95,7 +104,8 @@ main(void)
 		perror_msg_and_fail("sched_getaffinity(%d, %u, %p) = %s\n",
 				    pid, big_size, cpuset, errstr);
 	assert(ret_size <= (int) big_size);
-	printf("sched_getaffinity(%d, %u, [", pid, big_size);
+	pidns_print_leader();
+	printf("sched_getaffinity(%d%s, %u, [", pid, pid_str, big_size);
 	for (i = 0, sep = ""; i < (unsigned) ret_size * 8; ++i) {
 		if (CPU_ISSET_S(i, (unsigned) ret_size, cpuset)) {
 			printf("%s%u", sep, i);
@@ -104,6 +114,7 @@ main(void)
 	}
 	printf("]) = %s\n", errstr);
 
+	pidns_print_leader();
 	puts("+++ exited with 0 +++");
 	return 0;
 }
diff --git a/tests/sched_xetattr--pidns-translation.c b/tests/sched_xetattr--pidns-translation.c
new file mode 100644
index 00000000..c152023d
--- /dev/null
+++ b/tests/sched_xetattr--pidns-translation.c
@@ -0,0 +1,2 @@
+#define PIDNS_TRANSLATION
+#include "sched_xetattr.c"
diff --git a/tests/sched_xetattr.c b/tests/sched_xetattr.c
index c63d7a80..4a76b2d6 100644
--- a/tests/sched_xetattr.c
+++ b/tests/sched_xetattr.c
@@ -15,6 +15,7 @@
 # include <stdio.h>
 # include <sched.h>
 # include <unistd.h>
+# include "pidns.h"
 # include "sched_attr.h"
 # include "xlat.h"
 # include "xlat/schedulers.h"
@@ -41,6 +42,8 @@ sys_sched_setattr(kernel_ulong_t pid, kernel_ulong_t attr, kernel_ulong_t flags)
 int
 main(void)
 {
+	PIDNS_TEST_INIT;
+
 	static const kernel_ulong_t bogus_pid =
 		(kernel_ulong_t) 0xdefacedfacefeedULL;
 	static const kernel_ulong_t bogus_size =
@@ -48,20 +51,28 @@ main(void)
 	static const kernel_ulong_t bogus_flags =
 		(kernel_ulong_t) 0xdefaceddeadc0deULL;
 
+	const int pid = getpid();
+	const char *pid_str = pidns_pid2str(PT_TGID);
+
 	TAIL_ALLOC_OBJECT_CONST_PTR(struct sched_attr, attr);
 	TAIL_ALLOC_OBJECT_CONST_PTR(unsigned int, psize);
 	void *const efault = attr + 1;
 
-	sys_sched_getattr(0, 0, 0, 0);
-	printf("sched_getattr(0, NULL, 0, 0) = %s\n", errstr);
+	sys_sched_getattr(pid, 0, 0, 0);
+	pidns_print_leader();
+	printf("sched_getattr(%d%s, NULL, 0, 0) = %s\n",
+		pid, pid_str, errstr);
 
 	sys_sched_getattr(0, (unsigned long) attr, 0, 0);
+	pidns_print_leader();
 	printf("sched_getattr(0, %p, 0, 0) = %s\n", attr, errstr);
 
 	sys_sched_getattr(bogus_pid, 0, 0, 0);
+	pidns_print_leader();
 	printf("sched_getattr(%d, NULL, 0, 0) = %s\n", (int) bogus_pid, errstr);
 
 	sys_sched_getattr(-1U, (unsigned long) attr, bogus_size, bogus_flags);
+	pidns_print_leader();
 	printf("sched_getattr(-1, %p, %s%u, %u) = %s\n",
 	       attr,
 # if defined __arm64__ || defined __aarch64__
@@ -72,11 +83,13 @@ main(void)
 	       (unsigned) bogus_size, (unsigned) bogus_flags, errstr);
 
 	sys_sched_getattr(0, (unsigned long) efault, SCHED_ATTR_MIN_SIZE, 0);
+	pidns_print_leader();
 	printf("sched_getattr(0, %p, %u, 0) = %s\n",
 	       efault, (unsigned) SCHED_ATTR_MIN_SIZE, errstr);
 
 	if (sys_sched_getattr(0, (unsigned long) attr, SCHED_ATTR_MIN_SIZE, 0))
 		perror_msg_and_skip("sched_getattr");
+	pidns_print_leader();
 	printf("sched_getattr(0, {size=%u, sched_policy=", attr->size);
 	printxval(schedulers, attr->sched_policy, NULL);
 	printf(", sched_flags=%s, sched_nice=%d, sched_priority=%u"
@@ -91,11 +104,13 @@ main(void)
 	       (unsigned) SCHED_ATTR_MIN_SIZE);
 
 	sys_sched_getattr(0, (unsigned long) efault, sizeof(*attr), 0);
+	pidns_print_leader();
 	printf("sched_getattr(0, %p, %u, 0) = %s\n",
 	       efault, (unsigned) sizeof(*attr), errstr);
 
 	if (sys_sched_getattr(0, (unsigned long) attr, sizeof(*attr), 0))
 		perror_msg_and_skip("sched_getattr");
+	pidns_print_leader();
 	printf("sched_getattr(0, {size=%u, sched_policy=", attr->size);
 	printxval(schedulers, attr->sched_policy, NULL);
 	printf(", sched_flags=%s, sched_nice=%d, sched_priority=%u"
@@ -121,11 +136,13 @@ main(void)
 			  F8ILL_KULONG_MASK | sizeof(*attr), F8ILL_KULONG_MASK);
 # if defined __arm64__ || defined __aarch64__
 	if (rc) {
+		pidns_print_leader();
 		printf("sched_getattr(0, %p, 0xffffffff<<32|%u, 0) = %s\n",
 		       attr, (unsigned) sizeof(*attr), errstr);
 	} else
 # endif
 	{
+		pidns_print_leader();
 		printf("sched_getattr(0, {size=%u, sched_policy=", attr->size);
 		printxval(schedulers, attr->sched_policy, NULL);
 		printf(", sched_flags=%s, sched_nice=%d, sched_priority=%u"
@@ -146,13 +163,16 @@ main(void)
 	}
 
 	sys_sched_setattr(bogus_pid, 0, 0);
+	pidns_print_leader();
 	printf("sched_setattr(%d, NULL, 0) = %s\n", (int) bogus_pid, errstr);
 
 	attr->sched_flags |= 1;
 
-	if (sys_sched_setattr(0, (unsigned long) attr, 0))
+	if (sys_sched_setattr(pid, (unsigned long) attr, 0))
 		perror_msg_and_skip("sched_setattr");
-	printf("sched_setattr(0, {size=%u, sched_policy=", attr->size);
+	pidns_print_leader();
+	printf("sched_setattr(%d%s, {size=%u, sched_policy=",
+		pid, pid_str, attr->size);
 	printxval(schedulers, attr->sched_policy, NULL);
 	printf(", sched_flags=%s, sched_nice=%d, sched_priority=%u"
 	       ", sched_runtime=%" PRIu64 ", sched_deadline=%" PRIu64
@@ -172,6 +192,7 @@ main(void)
 
 	sys_sched_setattr(F8ILL_KULONG_MASK, (unsigned long) attr,
 			  F8ILL_KULONG_MASK);
+	pidns_print_leader();
 	printf("sched_setattr(0, {size=%u, sched_policy=", attr->size);
 	printxval(schedulers, attr->sched_policy, NULL);
 	printf(", sched_flags=%s, sched_nice=%d, sched_priority=%u"
@@ -193,11 +214,13 @@ main(void)
 	*psize = attr->size;
 
 	sys_sched_setattr(0, (unsigned long) psize, 0);
+	pidns_print_leader();
 	printf("sched_setattr(0, %p, 0) = %s\n", psize, errstr);
 
 	attr->size = 0;
 
 	sys_sched_setattr(0, (unsigned long) attr, 0);
+	pidns_print_leader();
 	printf("sched_setattr(0, {size=%u, sched_policy=", attr->size);
 	printxval(schedulers, attr->sched_policy, NULL);
 	printf(", sched_flags=%s, sched_nice=%d, sched_priority=%u"
@@ -213,12 +236,14 @@ main(void)
 	attr->size = 1;
 
 	sys_sched_setattr(0, (unsigned long) attr, 0);
+	pidns_print_leader();
 	printf("sched_setattr(0, {size=%u} => {size=%u}, 0) = %s\n",
 	       1, attr->size, errstr);
 
 	attr->size = SCHED_ATTR_MIN_SIZE - 1;
 
 	sys_sched_setattr(0, (unsigned long) attr, 0);
+	pidns_print_leader();
 	printf("sched_setattr(0, {size=%u} => {size=%u}, 0) = %s\n",
 	       SCHED_ATTR_MIN_SIZE - 1, attr->size, errstr);
 
@@ -232,6 +257,7 @@ main(void)
 	attr->sched_period = 0xded1ca7edda7aca7ULL;
 
 	sys_sched_setattr(bogus_pid, (unsigned long) attr, bogus_flags);
+	pidns_print_leader();
 	printf("sched_setattr(%d, {size=%u, sched_policy=%#x /* SCHED_??? */, "
 	       "sched_flags=%#" PRIx64 " /* SCHED_FLAG_??? */, "
 	       "sched_nice=%d, sched_priority=%u, sched_runtime=%" PRIu64 ", "
@@ -274,6 +300,7 @@ main(void)
 	attr->sched_period = 0xded1ca7edda7aca7ULL;
 
 	sys_sched_setattr(bogus_pid, (unsigned long) attr, bogus_flags);
+	pidns_print_leader();
 	printf("sched_setattr(%d, {size=%u, sched_policy=%#x /* SCHED_??? */, "
 	       "sched_flags=SCHED_FLAG_RESET_ON_FORK|SCHED_FLAG_RECLAIM|"
 	       "SCHED_FLAG_DL_OVERRUN|0x80, "
@@ -296,11 +323,13 @@ main(void)
 		const kernel_ulong_t ill = f8ill_ptr_to_kulong(attr);
 
 		sys_sched_getattr(0, ill, sizeof(*attr), 0);
+		pidns_print_leader();
 		printf("sched_getattr(0, %#llx, %u, 0) = %s\n",
 		       (unsigned long long) ill, (unsigned) sizeof(*attr),
 		       errstr);
 
 		sys_sched_setattr(0, ill, 0);
+		pidns_print_leader();
 		printf("sched_setattr(0, %#llx, 0) = %s\n",
 		       (unsigned long long) ill, errstr);
 	}
@@ -310,6 +339,7 @@ main(void)
 	attr->sched_flags = 0x8fULL;
 
 	sys_sched_setattr(bogus_pid, (unsigned long) attr, bogus_flags);
+	pidns_print_leader();
 	printf("sched_setattr(%d, {size=%u, "
 	       "sched_flags=SCHED_FLAG_RESET_ON_FORK|SCHED_FLAG_RECLAIM|"
 	       "SCHED_FLAG_DL_OVERRUN|SCHED_FLAG_KEEP_POLICY|0x80, "
@@ -329,11 +359,13 @@ main(void)
 		const kernel_ulong_t ill = f8ill_ptr_to_kulong(attr);
 
 		sys_sched_getattr(0, ill, sizeof(*attr), 0);
+		pidns_print_leader();
 		printf("sched_getattr(0, %#llx, %u, 0) = %s\n",
 		       (unsigned long long) ill, (unsigned) sizeof(*attr),
 		       errstr);
 
 		sys_sched_setattr(0, ill, 0);
+		pidns_print_leader();
 		printf("sched_setattr(0, %#llx, 0) = %s\n",
 		       (unsigned long long) ill, errstr);
 	}
@@ -342,6 +374,7 @@ main(void)
 	attr->sched_flags = 0xe7ULL;
 
 	sys_sched_setattr(bogus_pid, (unsigned long) attr, bogus_flags);
+	pidns_print_leader();
 	printf("sched_setattr(%d, {size=%u, sched_policy=%#x /* SCHED_??? */, "
 	       "sched_flags=SCHED_FLAG_RESET_ON_FORK|SCHED_FLAG_RECLAIM|"
 	       "SCHED_FLAG_DL_OVERRUN|SCHED_FLAG_UTIL_CLAMP_MIN"
@@ -365,11 +398,13 @@ main(void)
 		const kernel_ulong_t ill = f8ill_ptr_to_kulong(attr);
 
 		sys_sched_getattr(0, ill, sizeof(*attr), 0);
+		pidns_print_leader();
 		printf("sched_getattr(0, %#llx, %u, 0) = %s\n",
 		       (unsigned long long) ill, (unsigned) sizeof(*attr),
 		       errstr);
 
 		sys_sched_setattr(0, ill, 0);
+		pidns_print_leader();
 		printf("sched_setattr(0, %#llx, 0) = %s\n",
 		       (unsigned long long) ill, errstr);
 	}
@@ -377,6 +412,7 @@ main(void)
 	attr->sched_flags = 0xcaffee90LL;
 
 	sys_sched_setattr(bogus_pid, (unsigned long) attr, bogus_flags);
+	pidns_print_leader();
 	printf("sched_setattr(%d, {size=%u, sched_flags=SCHED_FLAG_KEEP_PARAMS"
 	       "|0xcaffee80, sched_util_min=%u, sched_util_max=%u}, %u) = %s\n",
 	       (int) bogus_pid,
@@ -389,15 +425,18 @@ main(void)
 		const kernel_ulong_t ill = f8ill_ptr_to_kulong(attr);
 
 		sys_sched_getattr(0, ill, sizeof(*attr), 0);
+		pidns_print_leader();
 		printf("sched_getattr(0, %#llx, %u, 0) = %s\n",
 		       (unsigned long long) ill, (unsigned) sizeof(*attr),
 		       errstr);
 
 		sys_sched_setattr(0, ill, 0);
+		pidns_print_leader();
 		printf("sched_setattr(0, %#llx, 0) = %s\n",
 		       (unsigned long long) ill, errstr);
 	}
 
+	pidns_print_leader();
 	puts("+++ exited with 0 +++");
 	return 0;
 }
diff --git a/tests/sched_xetparam--pidns-translation.c b/tests/sched_xetparam--pidns-translation.c
new file mode 100644
index 00000000..9fb3e579
--- /dev/null
+++ b/tests/sched_xetparam--pidns-translation.c
@@ -0,0 +1,2 @@
+#define PIDNS_TRANSLATION
+#include "sched_xetparam.c"
diff --git a/tests/sched_xetparam.c b/tests/sched_xetparam.c
index de3915b2..aa9c68cc 100644
--- a/tests/sched_xetparam.c
+++ b/tests/sched_xetparam.c
@@ -7,6 +7,7 @@
 
 #include "tests.h"
 #include "scno.h"
+# include "pidns.h"
 
 #if defined __NR_sched_getparam && defined __NR_sched_setparam
 
@@ -17,18 +18,27 @@
 int
 main(void)
 {
+	PIDNS_TEST_INIT;
+
 	struct sched_param *const param =
 		tail_alloc(sizeof(struct sched_param));
 
-	long rc = syscall(__NR_sched_getparam, 0, param);
-	printf("sched_getparam(0, [%d]) = %ld\n",
-	       param->sched_priority, rc);
+	const int pid = getpid();
+	const char *pid_str = pidns_pid2str(PT_TGID);
+
+	long rc = syscall(__NR_sched_getparam, pid, param);
+	pidns_print_leader();
+	printf("sched_getparam(%d%s, [%d]) = %ld\n",
+	       pid, pid_str, param->sched_priority, rc);
 
 	param->sched_priority = -1;
-	rc = syscall(__NR_sched_setparam, 0, param);
-	printf("sched_setparam(0, [%d]) = %ld %s (%m)\n",
+	rc = syscall(__NR_sched_setparam, pid, param);
+	pidns_print_leader();
+	printf("sched_setparam(%d%s, [%d]) = %ld %s (%m)\n",
+	       pid, pid_str,
 	       param->sched_priority, rc, errno2name());
 
+	pidns_print_leader();
 	puts("+++ exited with 0 +++");
 	return 0;
 }
diff --git a/tests/sched_xetscheduler--pidns-translation.c b/tests/sched_xetscheduler--pidns-translation.c
new file mode 100644
index 00000000..78b794b2
--- /dev/null
+++ b/tests/sched_xetscheduler--pidns-translation.c
@@ -0,0 +1,2 @@
+#define PIDNS_TRANSLATION
+#include "sched_xetscheduler.c"
diff --git a/tests/sched_xetscheduler.c b/tests/sched_xetscheduler.c
index 047e8676..91b5e32d 100644
--- a/tests/sched_xetscheduler.c
+++ b/tests/sched_xetscheduler.c
@@ -7,6 +7,7 @@
 
 #include "tests.h"
 #include "scno.h"
+#include "pidns.h"
 
 #if defined __NR_sched_getscheduler && defined __NR_sched_setscheduler
 
@@ -17,8 +18,13 @@
 int
 main(void)
 {
+	PIDNS_TEST_INIT;
+
 	TAIL_ALLOC_OBJECT_CONST_PTR(struct sched_param, param);
-	long rc = syscall(__NR_sched_getscheduler, 0);
+	const int pid = getpid();
+	const char *pid_str = pidns_pid2str(PT_TGID);
+
+	long rc = syscall(__NR_sched_getscheduler, pid);
 	const char *scheduler;
 	switch (rc) {
 		case SCHED_FIFO:
@@ -50,33 +56,43 @@ main(void)
 		default:
 			scheduler = "SCHED_OTHER";
 	}
-	printf("sched_getscheduler(0) = %ld (%s)\n",
-	       rc, scheduler);
+	pidns_print_leader();
+	printf("sched_getscheduler(%d%s) = %ld (%s)\n",
+	       pid, pid_str, rc, scheduler);
 
 	rc = syscall(__NR_sched_getscheduler, -1);
+	pidns_print_leader();
 	printf("sched_getscheduler(-1) = %s\n", sprintrc(rc));
 
 	param->sched_priority = -1;
 
-	rc = syscall(__NR_sched_setscheduler, 0, SCHED_FIFO, NULL);
-	printf("sched_setscheduler(0, SCHED_FIFO, NULL) = %s\n", sprintrc(rc));
+	rc = syscall(__NR_sched_setscheduler, pid, SCHED_FIFO, NULL);
+	pidns_print_leader();
+	printf("sched_setscheduler(%d%s, SCHED_FIFO, NULL) = %s\n",
+	       pid, pid_str, sprintrc(rc));
 
-	rc = syscall(__NR_sched_setscheduler, 0, SCHED_FIFO, param + 1);
-	printf("sched_setscheduler(0, SCHED_FIFO, %p) = %s\n", param + 1,
-	       sprintrc(rc));
+	rc = syscall(__NR_sched_setscheduler, pid, SCHED_FIFO, param + 1);
+	pidns_print_leader();
+	printf("sched_setscheduler(%d%s, SCHED_FIFO, %p) = %s\n",
+	       pid, pid_str, param + 1, sprintrc(rc));
 
-	rc = syscall(__NR_sched_setscheduler, 0, 0xfaceda7a, param);
-	printf("sched_setscheduler(0, %#x /* SCHED_??? */, [%d]) = %s\n",
-	       0xfaceda7a, param->sched_priority, sprintrc(rc));
+	rc = syscall(__NR_sched_setscheduler, pid, 0xfaceda7a, param);
+	pidns_print_leader();
+	printf("sched_setscheduler(%d%s, %#x /* SCHED_??? */, [%d]) = %s\n",
+	       pid, pid_str, 0xfaceda7a,
+	       param->sched_priority, sprintrc(rc));
 
 	rc = syscall(__NR_sched_setscheduler, -1, SCHED_FIFO, param);
+	pidns_print_leader();
 	printf("sched_setscheduler(-1, SCHED_FIFO, [%d]) = %s\n",
 	       param->sched_priority, sprintrc(rc));
 
-	rc = syscall(__NR_sched_setscheduler, 0, SCHED_FIFO, param);
-	printf("sched_setscheduler(0, SCHED_FIFO, [%d]) = %s\n",
-	       param->sched_priority, sprintrc(rc));
+	rc = syscall(__NR_sched_setscheduler, pid, SCHED_FIFO, param);
+	pidns_print_leader();
+	printf("sched_setscheduler(%d%s, SCHED_FIFO, [%d]) = %s\n",
+	       pid, pid_str, param->sched_priority, sprintrc(rc));
 
+	pidns_print_leader();
 	puts("+++ exited with 0 +++");
 	return 0;
 }
diff --git a/tests/signal_receive--pidns-translation.c b/tests/signal_receive--pidns-translation.c
new file mode 100644
index 00000000..b4e3b2f8
--- /dev/null
+++ b/tests/signal_receive--pidns-translation.c
@@ -0,0 +1,2 @@
+#define PIDNS_TRANSLATION
+#include "signal_receive.c"
diff --git a/tests/signal_receive.c b/tests/signal_receive.c
index ad3b4ebd..70441a9e 100644
--- a/tests/signal_receive.c
+++ b/tests/signal_receive.c
@@ -8,6 +8,7 @@
  */
 
 #include "tests.h"
+#include "pidns.h"
 #include <signal.h>
 #include <stdio.h>
 #include <unistd.h>
@@ -26,10 +27,13 @@ handler(int sig, siginfo_t *info, void *ucontext)
 int
 main(void)
 {
+	PIDNS_TEST_INIT;
+
 	static const char prefix[] = "KERNEL BUG";
 	int printed = 0;
 
 	const int pid = getpid();
+	const char *pid_str = pidns_pid2str(PT_TGID);
 	const int uid = geteuid();
 
 	for (int sig = 1; sig <= 31; ++sig) {
@@ -73,10 +77,13 @@ main(void)
 		const int e_pid = s_pid;
 		const int e_uid = s_uid;
 #endif
-		printf("kill(%d, %s) = 0\n", pid, signal2name(sig));
-		printf("--- %s {si_signo=%s, si_code=SI_USER, si_pid=%d"
+		pidns_print_leader();
+		printf("kill(%d%s, %s) = 0\n", pid, pid_str, signal2name(sig));
+		pidns_print_leader();
+		printf("--- %s {si_signo=%s, si_code=SI_USER, si_pid=%d%s"
 		       ", si_uid=%d} ---\n",
-		       signal2name(sig), signal2name(e_sig), e_pid, e_uid);
+		       signal2name(sig), signal2name(e_sig),
+		       e_pid, pid_str, e_uid);
 
 		if (s_code || sig != s_sig || pid != s_pid || uid != s_uid) {
 			/*
@@ -91,11 +98,11 @@ main(void)
 			}
 			fprintf(stderr,
 				"%s: expected: si_signo=%d, si_code=%d"
-				", si_pid=%d, si_uid=%d\n"
+				", si_pid=%d%s, si_uid=%d\n"
 				"%s: received: si_signo=%d, si_code=%d"
-				", si_pid=%d, si_uid=%d\n",
-				prefix, sig, SI_USER, pid, uid,
-				prefix, sig, s_code, s_pid, s_uid);
+				", si_pid=%d%s, si_uid=%d\n",
+				prefix, sig, SI_USER, pid, pid_str, uid,
+				prefix, sig, s_code, s_pid, pid_str, s_uid);
 		}
 	}
 
@@ -104,6 +111,7 @@ main(void)
 			"*** PLEASE FIX THE KERNEL ***\n", prefix);
 	}
 
+	pidns_print_leader();
 	puts("+++ exited with 0 +++");
 	return 0;
 }
diff --git a/tests/so_peercred--pidns-translation.c b/tests/so_peercred--pidns-translation.c
new file mode 100644
index 00000000..402bbcfe
--- /dev/null
+++ b/tests/so_peercred--pidns-translation.c
@@ -0,0 +1,2 @@
+#define PIDNS_TRANSLATION
+#include "so_peercred.c"
diff --git a/tests/so_peercred.c b/tests/so_peercred.c
index 151bb175..20188bdb 100644
--- a/tests/so_peercred.c
+++ b/tests/so_peercred.c
@@ -9,6 +9,7 @@
  */
 
 #include "tests.h"
+#include "pidns.h"
 
 #include <stddef.h>
 #include <stdio.h>
@@ -53,6 +54,8 @@ so_str(void)
 int
 main(void)
 {
+	PIDNS_TEST_INIT;
+
 	TAIL_ALLOC_OBJECT_CONST_PTR(struct ucred, peercred);
 	TAIL_ALLOC_OBJECT_CONST_PTR(socklen_t, len);
 
@@ -75,6 +78,8 @@ main(void)
 	struct ucred *const gid_truncated =
 		tail_alloc(sizeof_gid_truncated);
 
+	const char *pid_str = pidns_pid2str(PT_TGID);
+
 	int sv[2];
 	if (socketpair(AF_UNIX, SOCK_STREAM, 0, sv))
                 perror_msg_and_skip("socketpair AF_UNIX SOCK_STREAM");
@@ -82,8 +87,10 @@ main(void)
 	/* classic getsockopt */
 	*len = sizeof(*peercred);
 	get_peercred(sv[0], peercred, len);
+	pidns_print_leader();
 	printf("getsockopt(%d, %s", sv[0], so_str());
 	PRINT_FIELD_D(", {", *peercred, pid);
+	printf("%s", pid_str);
 	PRINT_FIELD_UID(", ", *peercred, uid);
 	PRINT_FIELD_UID(", ", *peercred, gid);
 	printf("}, [%d]) = %s\n", *len, errstr);
@@ -91,14 +98,17 @@ main(void)
 	/* getsockopt with zero optlen */
 	*len = 0;
 	get_peercred(sv[0], peercred, len);
+	pidns_print_leader();
 	printf("getsockopt(%d, %s, %p, [0]) = %s\n",
 	       sv[0], so_str(), peercred, errstr);
 
 	/* getsockopt with optlen larger than necessary - shortened */
 	*len = sizeof(*peercred) + 1;
 	get_peercred(sv[0], peercred, len);
+	pidns_print_leader();
 	printf("getsockopt(%d, %s", sv[0], so_str());
 	PRINT_FIELD_D(", {", *peercred, pid);
+	printf("%s", pid_str);
 	PRINT_FIELD_UID(", ", *peercred, uid);
 	PRINT_FIELD_UID(", ", *peercred, gid);
 	printf("}, [%u->%d]) = %s\n",
@@ -110,6 +120,7 @@ main(void)
 	 */
 	*len = sizeof_pid_truncated;
 	get_peercred(sv[0], pid_truncated, len);
+	pidns_print_leader();
 	printf("getsockopt(%d, %s, {pid=", sv[0], so_str());
 	print_quoted_hex(pid_truncated, *len);
 	printf("}, [%d]) = %s\n", *len, errstr);
@@ -120,8 +131,10 @@ main(void)
 	 */
 	*len = sizeof_pid;
 	get_peercred(sv[0], pid, len);
+	pidns_print_leader();
 	printf("getsockopt(%d, %s", sv[0], so_str());
 	PRINT_FIELD_D(", {", *pid, pid);
+	printf("%s", pid_str);
 	printf("}, [%d]) = %s\n", *len, errstr);
 
 	/*
@@ -136,8 +149,10 @@ main(void)
 	 * to struct ucred.pid field.
 	 */
 	memcpy(uid, uid_truncated, sizeof_uid_truncated);
+	pidns_print_leader();
 	printf("getsockopt(%d, %s", sv[0], so_str());
 	PRINT_FIELD_D(", {", *uid, pid);
+	printf("%s", pid_str);
 	printf(", uid=");
 	print_quoted_hex(&uid->uid, sizeof_uid_truncated -
 				    offsetof(struct ucred, uid));
@@ -149,8 +164,10 @@ main(void)
 	 */
 	*len = sizeof_uid;
 	get_peercred(sv[0], uid, len);
+	pidns_print_leader();
 	printf("getsockopt(%d, %s", sv[0], so_str());
 	PRINT_FIELD_D(", {", *uid, pid);
+	printf("%s", pid_str);
 	PRINT_FIELD_UID(", ", *uid, uid);
 	printf("}, [%d]) = %s\n", *len, errstr);
 
@@ -166,8 +183,10 @@ main(void)
 	 * to struct ucred.pid and struct ucred.uid fields.
 	 */
 	memcpy(peercred, gid_truncated, sizeof_gid_truncated);
+	pidns_print_leader();
 	printf("getsockopt(%d, %s", sv[0], so_str());
 	PRINT_FIELD_D(", {", *peercred, pid);
+	printf("%s", pid_str);
 	PRINT_FIELD_UID(", ", *peercred, uid);
 	printf(", gid=");
 	print_quoted_hex(&peercred->gid, sizeof_gid_truncated -
@@ -177,14 +196,17 @@ main(void)
 	/* getsockopt optval EFAULT */
 	*len = sizeof(*peercred);
 	get_peercred(sv[0], &peercred->uid, len);
+	pidns_print_leader();
 	printf("getsockopt(%d, %s, %p, [%d]) = %s\n",
 	       sv[0], so_str(), &peercred->uid, *len, errstr);
 
 	/* getsockopt optlen EFAULT */
 	get_peercred(sv[0], peercred, len + 1);
+	pidns_print_leader();
 	printf("getsockopt(%d, %s, %p, %p) = %s\n",
 	       sv[0], so_str(), peercred, len + 1, errstr);
 
+	pidns_print_leader();
 	puts("+++ exited with 0 +++");
 	return 0;
 }
diff --git a/tests/xet_robust_list--pidns-translation.c b/tests/xet_robust_list--pidns-translation.c
new file mode 100644
index 00000000..e0477267
--- /dev/null
+++ b/tests/xet_robust_list--pidns-translation.c
@@ -0,0 +1,2 @@
+#define PIDNS_TRANSLATION
+#include "xet_robust_list.c"
diff --git a/tests/xet_robust_list.c b/tests/xet_robust_list.c
index 43239c8b..b5751b0a 100644
--- a/tests/xet_robust_list.c
+++ b/tests/xet_robust_list.c
@@ -8,6 +8,7 @@
 
 #include "tests.h"
 #include "scno.h"
+#include "pidns.h"
 
 #if defined __NR_get_robust_list && defined __NR_set_robust_list
 
@@ -30,27 +31,36 @@ sprintaddr(void *addr)
 int
 main(void)
 {
+	PIDNS_TEST_INIT;
+
 	const pid_t pid = getpid();
+	const char *pid_str = pidns_pid2str(PT_TGID);
 	const long long_pid = (unsigned long) (0xdeadbeef00000000LL | pid);
 	TAIL_ALLOC_OBJECT_CONST_PTR(void *, p_head);
 	TAIL_ALLOC_OBJECT_CONST_PTR(size_t, p_len);
 
 	if (syscall(__NR_get_robust_list, long_pid, p_head, p_len))
 		perror_msg_and_skip("get_robust_list");
-	printf("get_robust_list(%d, [%s], [%lu]) = 0\n",
-	       (int) pid, sprintaddr(*p_head), (unsigned long) *p_len);
+	pidns_print_leader();
+	printf("get_robust_list(%d%s, [%s], [%lu]) = 0\n",
+	       pid, pid_str, sprintaddr(*p_head),
+	       (unsigned long) *p_len);
 
 	void *head = tail_alloc(*p_len);
 	if (syscall(__NR_set_robust_list, head, *p_len))
 		perror_msg_and_skip("set_robust_list");
+	pidns_print_leader();
 	printf("set_robust_list(%p, %lu) = 0\n",
 	       head, (unsigned long) *p_len);
 
 	if (syscall(__NR_get_robust_list, long_pid, p_head, p_len))
 		perror_msg_and_skip("get_robust_list");
-	printf("get_robust_list(%d, [%s], [%lu]) = 0\n",
-	       (int) pid, sprintaddr(*p_head), (unsigned long) *p_len);
+	pidns_print_leader();
+	printf("get_robust_list(%d%s, [%s], [%lu]) = 0\n",
+	       pid, pid_str, sprintaddr(*p_head),
+	       (unsigned long) *p_len);
 
+	pidns_print_leader();
 	puts("+++ exited with 0 +++");
 	return 0;
 }
diff --git a/tests/xetpgid--pidns-translation.c b/tests/xetpgid--pidns-translation.c
new file mode 100644
index 00000000..b6469628
--- /dev/null
+++ b/tests/xetpgid--pidns-translation.c
@@ -0,0 +1,2 @@
+#define PIDNS_TRANSLATION
+#include "xetpgid.c"
diff --git a/tests/xetpgid.c b/tests/xetpgid.c
index 9b070af2..411edfc7 100644
--- a/tests/xetpgid.c
+++ b/tests/xetpgid.c
@@ -10,6 +10,7 @@
 
 #include "tests.h"
 #include "scno.h"
+#include "pidns.h"
 
 #if defined __NR_getpgid && defined __NR_setpgid
 
@@ -19,13 +20,21 @@
 int
 main(void)
 {
-	const int pid = getpid();
-	long rc = syscall(__NR_getpgid, F8ILL_KULONG_MASK | pid);
-	printf("getpgid(%d) = %ld\n", pid, rc);
-
-	rc = syscall(__NR_setpgid, F8ILL_KULONG_MASK, F8ILL_KULONG_MASK | pid);
-	printf("setpgid(0, %d) = %ld\n", pid, rc);
+	PIDNS_TEST_INIT;
 
+	const int pid = getpid();
+	long pgid = syscall(__NR_getpgid, F8ILL_KULONG_MASK | pid);
+	pidns_print_leader();
+	printf("getpgid(%d%s) = %ld%s\n", pid, pidns_pid2str(PT_TGID),
+		pgid, pidns_pid2str(PT_PGID));
+
+	long rc = syscall(__NR_setpgid, F8ILL_KULONG_MASK,
+		F8ILL_KULONG_MASK | pgid);
+	pidns_print_leader();
+	printf("setpgid(0, %ld%s) = %s\n", pgid, pidns_pid2str(PT_PGID),
+		sprintrc(rc));
+
+	pidns_print_leader();
 	puts("+++ exited with 0 +++");
 	return 0;
 }
diff --git a/tests/xetpriority--pidns-translation.c b/tests/xetpriority--pidns-translation.c
new file mode 100644
index 00000000..c93669cb
--- /dev/null
+++ b/tests/xetpriority--pidns-translation.c
@@ -0,0 +1,2 @@
+#define PIDNS_TRANSLATION
+#include "xetpriority.c"
diff --git a/tests/xetpriority.c b/tests/xetpriority.c
index 2d61bd10..dd38217d 100644
--- a/tests/xetpriority.c
+++ b/tests/xetpriority.c
@@ -7,6 +7,7 @@
 
 #include "tests.h"
 #include "scno.h"
+#include "pidns.h"
 
 #if defined __NR_getpriority && defined __NR_setpriority
 
@@ -17,15 +18,30 @@
 int
 main(void)
 {
+	PIDNS_TEST_INIT;
+
 	const int pid = getpid();
+	const int pgid = getpgid(0);
+
 	long rc = syscall(__NR_getpriority, PRIO_PROCESS,
 			  F8ILL_KULONG_MASK | pid);
-	printf("getpriority(PRIO_PROCESS, %d) = %ld\n", pid, rc);
+	pidns_print_leader();
+	printf("getpriority(PRIO_PROCESS, %d%s) = %ld\n",
+		pid, pidns_pid2str(PT_TGID), rc);
 
 	rc = syscall(__NR_setpriority, PRIO_PROCESS,
 		     F8ILL_KULONG_MASK | pid, F8ILL_KULONG_MASK);
-	printf("setpriority(PRIO_PROCESS, %d, 0) = %s\n", pid, sprintrc(rc));
+	pidns_print_leader();
+	printf("setpriority(PRIO_PROCESS, %d%s, 0) = %s\n",
+		pid, pidns_pid2str(PT_TGID), sprintrc(rc));
+
+	rc = syscall(__NR_getpriority, PRIO_PGRP,
+			  F8ILL_KULONG_MASK | pgid);
+	pidns_print_leader();
+	printf("getpriority(PRIO_PGRP, %d%s) = %ld\n",
+		pgid, pidns_pid2str(PT_PGID), rc);
 
+	pidns_print_leader();
 	puts("+++ exited with 0 +++");
 	return 0;
 }
-- 
2.27.0


From uzonyi.akos at gmail.com  Mon Aug  3 19:19:15 2020
From: uzonyi.akos at gmail.com (=?UTF-8?q?=C3=81kos=20Uzonyi?=)
Date: Mon,  3 Aug 2020 21:19:15 +0200
Subject: [PATCH v5 4/5] Implement testing framework for pidns
In-Reply-To: <20200803191916.94724-1-uzonyi.akos@gmail.com>
References: <20200803191916.94724-1-uzonyi.akos@gmail.com>
Message-ID: <20200803191916.94724-5-uzonyi.akos@gmail.com>

* tests/pidns.c: New file.
* tests/pidns.h: New file.
* tests/Makefile.am (libtests_a_SOURCES): Add pidns.c, pidns.h.
* tests/init.sh (test_pidns, test_pidns_run_strace): New functions.
---
 tests/Makefile.am |   2 +
 tests/init.sh     |  31 +++++++
 tests/pidns.c     | 214 ++++++++++++++++++++++++++++++++++++++++++++++
 tests/pidns.h     |  56 ++++++++++++
 4 files changed, 303 insertions(+)
 create mode 100644 tests/pidns.c
 create mode 100644 tests/pidns.h

diff --git a/tests/Makefile.am b/tests/Makefile.am
index 28d95e39..7a583a3a 100644
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@@ -44,6 +44,8 @@ libtests_a_SOURCES = \
 	libsocketcall.c \
 	lock_file.c \
 	overflowuid.c \
+	pidns.c \
+	pidns.h \
 	pipe_maxfd.c \
 	print_quoted_string.c \
 	print_time.c \
diff --git a/tests/init.sh b/tests/init.sh
index d78e697b..7325fa4a 100644
--- a/tests/init.sh
+++ b/tests/init.sh
@@ -387,6 +387,37 @@ test_prog_set()
 	test_pure_prog_set "$@" < "$srcdir/$NAME.in"
 }
 
+test_pidns_run_strace()
+{
+	local parent_pid
+
+	check_prog tail
+	check_prog cut
+	check_prog grep
+
+	run_prog > /dev/null
+	run_strace --pidns-translation -f $@ $args > "$EXP"
+
+	# filter out logs made by the parent or init process of the pidns test
+	parent_pid="$(tail -n 2 $LOG | head -n 1 | cut -d' ' -f1)"
+	init_pid="$(tail -n 1 $LOG | cut -d' ' -f1)"
+	grep -E -v "^($parent_pid|$init_pid) " "$LOG" > "$OUT"
+	match_diff "$OUT" "$EXP"
+}
+
+test_pidns()
+{
+	# ioctl(NS_GET_PARENT) is added in Linux 4.9
+	require_min_kernel_version_or_skip 4.9
+	check_prog unshare
+
+	test_pidns_run_strace "$@"
+
+	# test PID translation when /proc is mounted from an other namespace
+	STRACE="unshare -Urpf $STRACE"
+	test_pidns_run_strace "$@"
+}
+
 check_prog cat
 check_prog rm
 
diff --git a/tests/pidns.c b/tests/pidns.c
new file mode 100644
index 00000000..f54af340
--- /dev/null
+++ b/tests/pidns.c
@@ -0,0 +1,214 @@
+/*
+ * Testing framework for PID namespace translation
+ *
+ * Copyright (c) 2020 ?kos Uzonyi <uzonyi.akos at gmail.com>
+ * All rights reserved.
+ *
+ * SPDX-License-Identifier: LGPL-2.1-or-later
+ */
+#include "tests.h"
+#include "pidns.h"
+#include "nsfs.h"
+
+#include <errno.h>
+#include <stdio.h>
+#include <string.h>
+#include <sys/types.h>
+#include <signal.h>
+#include <stdlib.h>
+#include <sched.h>
+#include <unistd.h>
+#include <sys/wait.h>
+#include <linux/sched.h>
+#include <fcntl.h>
+#include <sys/ioctl.h>
+
+static bool pidns_translation = false;
+static bool pidns_unshared = false;
+
+/* Our PIDs in strace's namespace */
+static pid_t pidns_strace_ids[PT_COUNT];
+
+void
+pidns_print_leader(void)
+{
+	if (pidns_translation)
+		printf("%-5d ", pidns_strace_ids[PT_TID]);
+}
+
+const char *
+pidns_pid2str(enum pid_type type)
+{
+	static const char format[] = " /* %d in strace's PID NS */";
+	static char buf[PT_COUNT][sizeof(format) + sizeof(int) * 3];
+
+	if (type < 0 || type >= PT_COUNT)
+		return "";
+
+	if (!pidns_unshared || !pidns_strace_ids[type])
+		return "";
+
+	snprintf(buf[type], sizeof(buf[type]), format, pidns_strace_ids[type]);
+	return buf[type];
+}
+
+/**
+ * This function is like fork, but does a few more things. It sets up the
+ * child's PGID and SID according to the parameters. Also it fills the
+ * pidns_strace_ids array in the child's memory with the PIDs of the child in
+ * parent's PID namespace. In the parent it waits for the child to terminate
+ * (but leaves the zombie to use it later as a process group). If the child
+ * terminates with nonzero exit status, the test is failed.
+ *
+ * @param pgid     The process group the child should be moved to. It's expected
+ *                 to be a PID of a zombie process (will be reaped). If
+ *                 negative, leave the child in the process group of the parent.
+ *                 If 0, move the process to its own process group.
+ * @param new_sid  Wheather child should be moved to a new session.
+ */
+static pid_t
+pidns_fork(pid_t pgid, bool new_sid)
+{
+	int strace_ids_pipe[2];
+	if (pipe(strace_ids_pipe) < 0)
+		perror_msg_and_fail("pipe");
+
+	fflush(stdout);
+	pid_t pid = fork();
+	if (pid < 0)
+		perror_msg_and_fail("fork");
+
+	if (!pid) {
+		close(strace_ids_pipe[1]);
+		if (read(strace_ids_pipe[0], pidns_strace_ids,
+		    sizeof(pidns_strace_ids)) < 0)
+			perror_msg_and_fail("read");
+		close(strace_ids_pipe[0]);
+
+		if (pidns_strace_ids[PT_SID])
+			setsid();
+
+		return 0;
+	}
+
+	pidns_strace_ids[PT_TID] = pid;
+	pidns_strace_ids[PT_TGID] = pid;
+	pidns_strace_ids[PT_PGID] = 0;
+	pidns_strace_ids[PT_SID] = 0;
+
+	if (!pgid)
+		pgid = pid;
+
+	if (pgid > 0) {
+		if (setpgid(pid, pgid) < 0)
+			perror_msg_and_fail("setpgid");
+
+		pidns_strace_ids[PT_PGID] = pgid;
+	}
+
+	/* Reap group leader to test PGID decoding */
+	if (pgid > 0 && pgid != pid) {
+		int ret = waitpid(pgid, NULL, WNOHANG);
+		if (ret < 0)
+			perror_msg_and_fail("wait");
+		if (!ret)
+			error_msg_and_fail("could not reap group leader");
+	}
+
+	if (new_sid) {
+		pidns_strace_ids[PT_SID] = pid;
+		pidns_strace_ids[PT_PGID] = pid;
+	}
+
+	if (write(strace_ids_pipe[1], pidns_strace_ids,
+	    sizeof(pidns_strace_ids)) < 0)
+		perror_msg_and_fail("write");
+	close(strace_ids_pipe[0]);
+	close(strace_ids_pipe[1]);
+
+	/* WNOWAIT: leave the zombie, to be able to use it as a process group */
+	siginfo_t siginfo;
+	if (waitid(P_PID, pid, &siginfo, WEXITED | WNOWAIT) < 0)
+		perror_msg_and_fail("wait");
+	if (siginfo.si_code != CLD_EXITED || siginfo.si_status)
+		error_msg_and_fail("child terminated with nonzero exit status");
+
+	return pid;
+}
+
+static void
+create_init_process(void)
+{
+	int child_pipe[2];
+	if (pipe(child_pipe) < 0)
+		perror_msg_and_fail("pipe");
+
+	pid_t pid = fork();
+	if (pid < 0)
+		perror_msg_and_fail("fork");
+
+	if (!pid) {
+		close(child_pipe[1]);
+		_exit(read(child_pipe[0], &child_pipe[1], sizeof(int)) == 0);
+	}
+
+	close(child_pipe[0]);
+}
+
+void
+check_ns_ioctl(void)
+{
+	int fd = open("/proc/self/ns/pid", O_RDONLY);
+	if (fd < 0)
+		perror_msg_and_fail("opening /proc/self/ns/pid");
+
+	int userns_fd = ioctl(fd, NS_GET_USERNS);
+	if (userns_fd < 0) {
+		if (errno == ENOTTY)
+			error_msg_and_skip("NS_* ioctl commands are not "
+			                   "supported by the kernel");
+		else
+			perror_msg_and_fail("ioctl(NS_GET_USERNS)");
+	}
+
+	close(userns_fd);
+	close(fd);
+}
+
+void
+pidns_test_init(void)
+{
+	pidns_translation = true;
+
+	check_ns_ioctl();
+
+	if (!pidns_fork(-1, false))
+		return;
+
+	/* Unshare user namespace too, so we do not need to be root */
+	if (unshare(CLONE_NEWUSER | CLONE_NEWPID) < 0) {
+		if (errno == EPERM)
+			perror_msg_and_skip("unshare");
+
+		perror_msg_and_fail("unshare");
+	}
+
+	pidns_unshared = true;
+
+	create_init_process();
+
+	if (!pidns_fork(-1, false))
+		return;
+
+	if (!pidns_fork(-1, true))
+		return;
+
+	pid_t pgid;
+	if (!(pgid = pidns_fork(0, false)))
+		return;
+
+	if (!pidns_fork(pgid, false))
+		return;
+
+	exit(0);
+}
diff --git a/tests/pidns.h b/tests/pidns.h
new file mode 100644
index 00000000..76963eb3
--- /dev/null
+++ b/tests/pidns.h
@@ -0,0 +1,56 @@
+/*
+ * Test PID namespace translation
+ *
+ * Copyright (c) 2020 ?kos Uzonyi <uzonyi.akos at gmail.com>
+ * All rights reserved.
+ *
+ * SPDX-License-Identifier: LGPL-2.1-or-later
+ */
+#ifndef STRACE_PIDNS_H
+#define STRACE_PIDNS_H
+
+#ifdef PIDNS_TRANSLATION
+# define PIDNS_TEST_INIT pidns_test_init()
+#else
+# define PIDNS_TEST_INIT
+#endif
+
+#include <sys/types.h>
+
+enum pid_type {
+	PT_TID,
+	PT_TGID,
+	PT_PGID,
+	PT_SID,
+
+	PT_COUNT,
+	PT_NONE = -1
+};
+
+/* Prints leader (process tid) if pidns_test_init was called */
+void pidns_print_leader(void);
+
+/*
+ * Returns a static buffer containing the translation string of our PID.
+ */
+const char *pidns_pid2str(enum pid_type type);
+
+/**
+ * Skips the test if NS_* ioctl commands are not supported by the kernel.
+ */
+void check_ns_ioctl(void);
+
+/**
+ * Init pidns testing.
+ *
+ * Should be called at the beginning of the test's main function
+ *
+ * This function calls fork a couple of times, and returns in the child
+ * processes. These child processes are in a new PID namespace with different
+ * PID configurations (group leader, session leader, ...). If any child
+ * terminates with nonzero exit status the test is failed. Otherwise the test is
+ * succesful, and the parent process exits with 0.
+ */
+void pidns_test_init(void);
+
+#endif
\ No newline at end of file
-- 
2.27.0


From uzonyi.akos at gmail.com  Mon Aug  3 19:19:13 2020
From: uzonyi.akos at gmail.com (=?UTF-8?q?=C3=81kos=20Uzonyi?=)
Date: Mon,  3 Aug 2020 21:19:13 +0200
Subject: [PATCH v5 2/5] Use printpid in decoders
In-Reply-To: <20200803191916.94724-1-uzonyi.akos@gmail.com>
References: <20200803191916.94724-1-uzonyi.akos@gmail.com>
Message-ID: <20200803191916.94724-3-uzonyi.akos@gmail.com>

* getpid.c: New file.
* Makefile.am (libstrace_a_SOURCES): Add getpid.c.
* linux/dummy.h (sys_getpid, sys_getppid, sys_gettid,
sys_setpgid, sys_setpgrp): Remove.
* util.c (printfd_pid_tracee_ns): Implement using translate_pid.
* defs.h (printnum_pid): New function definition.
(printfd_pid_tracee_ns): Update documentation
* util.c: (printnum_pid): New function.
* print_fields.h (PRINT_FIELD_TID): New macro.
(PRINT_FIELD_TGID): Likewise.
(PRINT_FIELD_PGID): Likewise.
(PRINT_FIELD_SID): Likewise.
* affinity.c: Print PIDs with printpid.
* block.c: Likewise.
* bpf.c: Likewise.
* capability.c: Likewise.
* clone.c: Likewise.
* fcntl.c: Likewise.
* get_robust_list.c: Likewise.
* ioprio.c: Likewise.
* kcmp.c: Likewise.
* msghdr.c: Likewise.
* net.c: Likewise.
* netlink.c: Likewise.
* numa.c: Likewise.
* pidfd_open.c: Likewise.
* printsiginfo.c: Likewise.
* process.c: Likewise.
* process_vm.c: Likewise.
* resource.c: Likewise.
* sched.c: Likewise.
* signal.c: Likewise.
* sockaddr.c: Likewise.
* wait.c: Likewise.
* kcmp.c (SYS_FUNC(kcmp)): Fix KCMP_FILE pid arguments.
* tests/kcmp.c (printpidfd): Print path if VERBOSE_FD.
(main): Use our real pid if real fds are used.
---
 Makefile.am       |  1 +
 affinity.c        |  6 ++++--
 block.c           |  2 +-
 bpf.c             |  2 +-
 capability.c      |  4 +++-
 clone.c           | 14 +++++++-------
 defs.h            |  5 ++++-
 fcntl.c           | 24 ++++++++++++++++++++++--
 get_robust_list.c |  3 ++-
 getpid.c          | 46 ++++++++++++++++++++++++++++++++++++++++++++++
 ioprio.c          | 26 ++++++++++++++++++++++----
 ipc_shmctl.c      |  5 +++--
 kcmp.c            |  5 ++++-
 linux/dummy.h     |  8 +-------
 msghdr.c          |  2 +-
 net.c             |  2 +-
 netlink.c         |  5 +++--
 numa.c            |  6 ++++--
 pidfd_open.c      |  2 +-
 print_fields.h    | 24 ++++++++++++++++++++++++
 printsiginfo.c    |  2 +-
 process.c         |  3 ++-
 process_vm.c      |  6 ++++--
 resource.c        | 27 ++++++++++++++++++++++++---
 sched.c           | 25 ++++++++++++++++---------
 signal.c          | 21 +++++++++++++++------
 sockaddr.c        |  2 +-
 tests/kcmp.c      | 25 ++++++++++++++++++++++---
 util.c            | 20 ++++++++++++++------
 wait.c            | 36 ++++++++++++++++++++++++------------
 30 files changed, 278 insertions(+), 81 deletions(-)
 create mode 100644 getpid.c

diff --git a/Makefile.am b/Makefile.am
index 73c22035..15fcd9a6 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -135,6 +135,7 @@ libstrace_a_SOURCES =	\
 	getcpu.c	\
 	getcwd.c	\
 	getpagesize.c \
+	getpid.c	\
 	getrandom.c	\
 	hdio.c		\
 	hostname.c	\
diff --git a/affinity.c b/affinity.c
index eb3158b7..f9893adb 100644
--- a/affinity.c
+++ b/affinity.c
@@ -82,7 +82,8 @@ SYS_FUNC(sched_setaffinity)
 	const int pid = tcp->u_arg[0];
 	const unsigned int len = tcp->u_arg[1];
 
-	tprintf("%d, %u, ", pid, len);
+	printpid(tcp, pid, PT_TGID);
+	tprintf(", %u, ", len);
 	print_affinitylist(tcp, tcp->u_arg[2], len);
 
 	return RVAL_DECODED;
@@ -94,7 +95,8 @@ SYS_FUNC(sched_getaffinity)
 	const unsigned int len = tcp->u_arg[1];
 
 	if (entering(tcp)) {
-		tprintf("%d, %u, ", pid, len);
+		printpid(tcp, pid, PT_TGID);
+		tprintf(", %u, ", len);
 	} else {
 		print_affinitylist(tcp, tcp->u_arg[2], tcp->u_rval);
 	}
diff --git a/block.c b/block.c
index a2f41551..231fa56b 100644
--- a/block.c
+++ b/block.c
@@ -179,7 +179,7 @@ MPERS_PRINTER_DECL(int, block_ioctl, struct tcb *const tcp,
 			PRINT_FIELD_U(", ", buts, buf_nr);
 			PRINT_FIELD_U(", ", buts, start_lba);
 			PRINT_FIELD_U(", ", buts, end_lba);
-			PRINT_FIELD_D(", ", buts, pid);
+			PRINT_FIELD_TGID(", ", buts, pid, tcp);
 			return 0;
 		} else {
 			struct_blk_user_trace_setup buts;
diff --git a/bpf.c b/bpf.c
index af830053..0ec33ba4 100644
--- a/bpf.c
+++ b/bpf.c
@@ -927,7 +927,7 @@ BEGIN_BPF_CMD_DECODER(BPF_TASK_FD_QUERY)
 	if (entering(tcp)) {
 		set_tcb_priv_ulong(tcp, attr.buf_len);
 
-		PRINT_FIELD_D("{task_fd_query={", attr, pid);
+		PRINT_FIELD_TGID("{task_fd_query={", attr, pid, tcp);
 		PRINT_FIELD_FD(", ", attr, fd, tcp);
 		PRINT_FIELD_U(", ", attr, flags);
 		PRINT_FIELD_U(", ", attr, buf_len);
diff --git a/capability.c b/capability.c
index 0e763ee1..812fb435 100644
--- a/capability.c
+++ b/capability.c
@@ -70,7 +70,9 @@ print_cap_header(struct tcb *const tcp, const kernel_ulong_t addr,
 	tprints("{version=");
 	printxval(cap_version, h->version,
 		  "_LINUX_CAPABILITY_VERSION_???");
-	tprintf(", pid=%d}", h->pid);
+	tprints(", pid=");
+	printpid(tcp, h->pid, PT_TGID);
+	tprints("}");
 }
 
 static void
diff --git a/clone.c b/clone.c
index 487c5c23..45f24065 100644
--- a/clone.c
+++ b/clone.c
@@ -114,14 +114,14 @@ SYS_FUNC(clone)
 		 */
 		if ((flags & (CLONE_PARENT_SETTID|CLONE_PIDFD|CLONE_CHILD_SETTID
 			      |CLONE_CHILD_CLEARTID|CLONE_SETTLS)) == 0)
-			return RVAL_DECODED;
+			return RVAL_DECODED | RVAL_TID;
 	} else {
 		if (flags & (CLONE_PARENT_SETTID|CLONE_PIDFD)) {
 			kernel_ulong_t addr = tcp->u_arg[ARG_PTID];
 
 			tprints(", parent_tid=");
 			if (flags & CLONE_PARENT_SETTID)
-				printnum_int(tcp, addr, "%u");
+				printnum_pid(tcp, addr, PT_TID);
 			else
 				printnum_fd(tcp, addr);
 		}
@@ -134,7 +134,7 @@ SYS_FUNC(clone)
 			printaddr(tcp->u_arg[ARG_CTID]);
 		}
 	}
-	return 0;
+	return RVAL_TID;
 }
 
 
@@ -229,7 +229,7 @@ SYS_FUNC(clone3)
 
 		if ((arg.flags & (CLONE_PIDFD | CLONE_PARENT_SETTID)) ||
 		    (size > fetch_size))
-			return 0;
+			return RVAL_TID;
 
 		goto out;
 	}
@@ -256,7 +256,7 @@ SYS_FUNC(clone3)
 
 	if (arg.flags & CLONE_PARENT_SETTID) {
 		tprintf("%sparent_tid=", pfx);
-		printnum_int(tcp, arg.parent_tid, "%d"); /* TID */
+		printnum_pid(tcp, arg.parent_tid, PT_TID);
 		pfx = ", ";
 	}
 
@@ -279,7 +279,7 @@ SYS_FUNC(clone3)
 out:
 	tprintf(", %" PRI_klu, size);
 
-	return RVAL_DECODED;
+	return RVAL_DECODED | RVAL_TID;
 }
 
 
@@ -300,5 +300,5 @@ SYS_FUNC(unshare)
 
 SYS_FUNC(fork)
 {
-	return RVAL_DECODED;
+	return RVAL_DECODED | RVAL_TGID;
 }
diff --git a/defs.h b/defs.h
index c16feb3c..38f123ee 100644
--- a/defs.h
+++ b/defs.h
@@ -1098,7 +1098,7 @@ printfd(struct tcb *tcp, int fd)
 
 /**
  * Print file descriptor fd owned by process with ID pid (from the PID NS
- * of the tracee the descriptor tcp).  This is a stub.
+ * of the tracee).
  */
 extern void printfd_pid_tracee_ns(struct tcb *tcp, pid_t pid, int fd);
 
@@ -1558,6 +1558,9 @@ DECL_PRINTNUM_ADDR(int64);
 extern bool
 printnum_fd(struct tcb *, kernel_ulong_t addr);
 
+extern bool
+printnum_pid(struct tcb *const tcp, const kernel_ulong_t addr, enum pid_type type);
+
 static inline bool
 printnum_slong(struct tcb *tcp, kernel_ulong_t addr)
 {
diff --git a/fcntl.c b/fcntl.c
index 345634c5..f4e69ea1 100644
--- a/fcntl.c
+++ b/fcntl.c
@@ -28,7 +28,7 @@ print_struct_flock64(struct tcb *const tcp, const struct_kernel_flock64 *fl, con
 	PRINT_FIELD_D(", ", *fl, l_start);
 	PRINT_FIELD_D(", ", *fl, l_len);
 	if (getlk)
-		PRINT_FIELD_D(", ", *fl, l_pid);
+		PRINT_FIELD_TGID(", ", *fl, l_pid, tcp);
 	tprints("}");
 }
 
@@ -59,7 +59,22 @@ print_f_owner_ex(struct tcb *const tcp, const kernel_ulong_t addr)
 		return;
 
 	PRINT_FIELD_XVAL("{", owner, type, f_owner_types, "F_OWNER_???");
-	PRINT_FIELD_D(", ", owner, pid);
+
+	enum pid_type pid_type = PT_NONE;
+	switch (owner.type)
+	{
+	case F_OWNER_TID:
+		pid_type = PT_TID;
+		break;
+	case F_OWNER_PID:
+		pid_type = PT_TGID;
+		break;
+	case F_OWNER_PGRP:
+		pid_type = PT_PGID;
+		break;
+	}
+	tprints(", pid=");
+	printpid(tcp, owner.pid, pid_type);
 	tprints("}");
 }
 
@@ -74,6 +89,9 @@ print_fcntl(struct tcb *tcp)
 		printflags(fdflags, tcp->u_arg[2], "FD_???");
 		break;
 	case F_SETOWN:
+		tprints(", ");
+		printpid_tgid_pgid(tcp, tcp->u_arg[2]);
+		break;
 	case F_SETPIPE_SZ:
 		tprintf(", %" PRI_kld, tcp->u_arg[2]);
 		break;
@@ -116,6 +134,8 @@ print_fcntl(struct tcb *tcp)
 		printsignal(tcp->u_arg[2]);
 		break;
 	case F_GETOWN:
+		return RVAL_DECODED |
+		       ((int) tcp->u_rval < 0 ? RVAL_PGID : RVAL_TGID);
 	case F_GETPIPE_SZ:
 		break;
 	case F_GETFD:
diff --git a/get_robust_list.c b/get_robust_list.c
index b5aebaff..4b771bac 100644
--- a/get_robust_list.c
+++ b/get_robust_list.c
@@ -10,7 +10,8 @@
 SYS_FUNC(get_robust_list)
 {
 	if (entering(tcp)) {
-		tprintf("%d, ", (int) tcp->u_arg[0]);
+		printpid(tcp, (int) tcp->u_arg[0], PT_TID);
+		tprints(", ");
 	} else {
 		printnum_ptr(tcp, tcp->u_arg[1]);
 		tprints(", ");
diff --git a/getpid.c b/getpid.c
new file mode 100644
index 00000000..5e9a1a29
--- /dev/null
+++ b/getpid.c
@@ -0,0 +1,46 @@
+/*
+ * Copyright (c) 2020 ?kos Uzonyi <uzonyi.akos at gmail.com>
+ * All rights reserved.
+ *
+ * SPDX-License-Identifier: LGPL-2.1-or-later
+ */
+
+#include "defs.h"
+
+SYS_FUNC(getpid)
+{
+	return RVAL_DECODED | RVAL_TGID;
+}
+
+SYS_FUNC(gettid)
+{
+	return RVAL_DECODED | RVAL_TID;
+}
+
+SYS_FUNC(getpgrp)
+{
+	return RVAL_DECODED | RVAL_PGID;
+}
+
+SYS_FUNC(getpgid)
+{
+	printpid(tcp, tcp->u_arg[0], PT_TGID);
+
+	return RVAL_DECODED | RVAL_PGID;
+}
+
+SYS_FUNC(getsid)
+{
+	printpid(tcp, tcp->u_arg[0], PT_TGID);
+
+	return RVAL_DECODED | RVAL_SID;
+}
+
+SYS_FUNC(setpgid)
+{
+	printpid(tcp, tcp->u_arg[0], PT_TGID);
+	tprints(", ");
+	printpid(tcp, tcp->u_arg[1], PT_PGID);
+
+	return RVAL_DECODED;
+}
diff --git a/ioprio.c b/ioprio.c
index 873c8ce5..52144884 100644
--- a/ioprio.c
+++ b/ioprio.c
@@ -49,13 +49,30 @@ print_ioprio(unsigned int ioprio)
 		? tprints_comment : tprints)(str);
 }
 
+static void
+ioprio_print_who(struct tcb *tcp, int which, int who)
+{
+	switch (which)
+	{
+	case IOPRIO_WHO_PROCESS:
+		printpid(tcp, who, PT_TGID);
+		break;
+	case IOPRIO_WHO_PGRP:
+		printpid(tcp, who, PT_PGID);
+		break;
+	default:
+		tprintf("%d", who);
+		break;
+	}
+}
+
 SYS_FUNC(ioprio_get)
 {
 	if (entering(tcp)) {
 		/* int which */
 		printxval(ioprio_who, tcp->u_arg[0], "IOPRIO_WHO_???");
-		/* int who */
-		tprintf(", %d", (int) tcp->u_arg[1]);
+		tprints(", ");
+		ioprio_print_who(tcp, (int) tcp->u_arg[0], (int) tcp->u_arg[1]);
 		return 0;
 	} else {
 		if (syserror(tcp))
@@ -72,8 +89,9 @@ SYS_FUNC(ioprio_set)
 {
 	/* int which */
 	printxval(ioprio_who, tcp->u_arg[0], "IOPRIO_WHO_???");
-	/* int who */
-	tprintf(", %d, ", (int) tcp->u_arg[1]);
+	tprints(", ");
+	ioprio_print_who(tcp, (int) tcp->u_arg[0], (int) tcp->u_arg[1]);
+	tprints(", ");
 	/* int ioprio */
 	if (xlat_verbose(xlat_verbosity) != XLAT_STYLE_ABBREV)
 		tprintf("%d", (int) tcp->u_arg[2]);
diff --git a/ipc_shmctl.c b/ipc_shmctl.c
index 8c9e1e7a..71b41651 100644
--- a/ipc_shmctl.c
+++ b/ipc_shmctl.c
@@ -12,6 +12,7 @@
  */
 
 #include "defs.h"
+#include "print_fields.h"
 
 #include DEF_MPERS_TYPE(shmid_ds_t)
 
@@ -53,8 +54,8 @@ print_shmid_ds(struct tcb *const tcp, const kernel_ulong_t addr, int cmd)
 		PRINT_FIELD_UID(", ", shmid_ds.shm_perm, cgid);
 		tprints("}");
 		tprintf(", shm_segsz=%u", (unsigned) shmid_ds.shm_segsz);
-		PRINT_FIELD_D(", ", shmid_ds, shm_cpid);
-		PRINT_FIELD_D(", ", shmid_ds, shm_lpid);
+		PRINT_FIELD_TGID(", ", shmid_ds, shm_cpid, tcp);
+		PRINT_FIELD_TGID(", ", shmid_ds, shm_lpid, tcp);
 		tprintf(", shm_nattch=%u", (unsigned) shmid_ds.shm_nattch);
 		tprintf(", shm_atime=%u", (unsigned) shmid_ds.shm_atime);
 		tprintf(", shm_dtime=%u", (unsigned) shmid_ds.shm_dtime);
diff --git a/kcmp.c b/kcmp.c
index 62115555..a5e1cdce 100644
--- a/kcmp.c
+++ b/kcmp.c
@@ -30,7 +30,10 @@ SYS_FUNC(kcmp)
 	kernel_ulong_t idx1 = tcp->u_arg[3];
 	kernel_ulong_t idx2 = tcp->u_arg[4];
 
-	tprintf("%d, %d, ", pid1, pid2);
+	printpid(tcp, pid1, PT_TGID);
+	tprints(", ");
+	printpid(tcp, pid2, PT_TGID);
+	tprints(", ");
 	printxval(kcmp_types, type, "KCMP_???");
 
 	switch (type) {
diff --git a/linux/dummy.h b/linux/dummy.h
index 2f859a60..ca0d2f0c 100644
--- a/linux/dummy.h
+++ b/linux/dummy.h
@@ -53,6 +53,7 @@
 # define sys_getgid		sys_getuid
 # define sys_getgid16		sys_getuid16
 # define sys_getpeername		sys_getsockname
+# define sys_getppid		sys_getpid
 # define sys_getresgid		sys_getresuid
 # define sys_getresgid16		sys_getresuid16
 # define sys_lstat		sys_stat
@@ -87,10 +88,6 @@
 # define sys_vfork		sys_fork
 
 /* printargs does the right thing */
-# define sys_getpgrp		printargs
-# define sys_getpid		printargs
-# define sys_getppid		printargs
-# define sys_gettid		printargs
 # define sys_idle		printargs
 # define sys_munlockall		printargs
 # define sys_pause		printargs
@@ -108,10 +105,7 @@
 
 /* printargs_d does the right thing */
 # define sys_exit		printargs_d
-# define sys_getpgid		printargs_d
-# define sys_getsid		printargs_d
 # define sys_nice		printargs_d
-# define sys_setpgid		printargs_d
 # define sys_setpgrp		printargs_d
 # define sys_timer_delete	printargs_d
 # define sys_timer_getoverrun	printargs_d
diff --git a/msghdr.c b/msghdr.c
index ef6dc24b..170b8e51 100644
--- a/msghdr.c
+++ b/msghdr.c
@@ -69,7 +69,7 @@ print_scm_creds(struct tcb *tcp, const void *cmsg_data,
 {
 	const struct ucred *uc = cmsg_data;
 
-	PRINT_FIELD_D("{", *uc, pid);
+	PRINT_FIELD_TGID("{", *uc, pid, tcp);
 	PRINT_FIELD_UID(", ", *uc, uid);
 	PRINT_FIELD_UID(", ", *uc, gid);
 	tprints("}");
diff --git a/net.c b/net.c
index 9ea34b22..6e899253 100644
--- a/net.c
+++ b/net.c
@@ -601,7 +601,7 @@ print_get_ucred(struct tcb *const tcp, const kernel_ulong_t addr,
 	if (umoven_or_printaddr(tcp, addr, len, &uc))
 		return;
 
-	PRINT_FIELD_LEN("{", uc, pid, len, PRINT_FIELD_D);
+	PRINT_FIELD_LEN("{", uc, pid, len, PRINT_FIELD_TGID, tcp);
 	PRINT_FIELD_LEN(", ", uc, uid, len, PRINT_FIELD_UID);
 	PRINT_FIELD_LEN(", ", uc, gid, len, PRINT_FIELD_UID);
 	tprints("}");
diff --git a/netlink.c b/netlink.c
index 88d864a9..cb29033a 100644
--- a/netlink.c
+++ b/netlink.c
@@ -446,8 +446,9 @@ print_nlmsghdr(struct tcb *tcp,
 	decode_nlmsg_flags(nlmsghdr->nlmsg_flags,
 			   nlmsghdr->nlmsg_type, family);
 
-	tprintf(", seq=%u, pid=%d}", nlmsghdr->nlmsg_seq,
-		nlmsghdr->nlmsg_pid);
+	tprintf(", seq=%u, pid=", nlmsghdr->nlmsg_seq);
+	printpid(tcp, nlmsghdr->nlmsg_pid, PT_TGID);
+	tprints("}");
 }
 
 static bool
diff --git a/numa.c b/numa.c
index cc7a7cc6..37b95397 100644
--- a/numa.c
+++ b/numa.c
@@ -44,7 +44,8 @@ print_nodemask(struct tcb *const tcp, const kernel_ulong_t addr,
 
 SYS_FUNC(migrate_pages)
 {
-	tprintf("%d, %" PRI_klu ", ", (int) tcp->u_arg[0], tcp->u_arg[1]);
+	printpid(tcp, (int) tcp->u_arg[0], PT_TGID);
+	tprintf(", %" PRI_klu ", ", tcp->u_arg[1]);
 	print_nodemask(tcp, tcp->u_arg[2], tcp->u_arg[1]);
 	tprints(", ");
 	print_nodemask(tcp, tcp->u_arg[3], tcp->u_arg[1]);
@@ -170,7 +171,8 @@ SYS_FUNC(move_pages)
 	kernel_ulong_t buf;
 
 	if (entering(tcp)) {
-		tprintf("%d, %" PRI_klu ", ", (int) tcp->u_arg[0], npages);
+		printpid(tcp, (int) tcp->u_arg[0], PT_TGID);
+		tprintf(", %" PRI_klu ", ", npages);
 		print_array(tcp, tcp->u_arg[2], npages, &buf, current_wordsize,
 			    tfetch_mem, print_addr, 0);
 		tprints(", ");
diff --git a/pidfd_open.c b/pidfd_open.c
index bbc7f617..10b5003d 100644
--- a/pidfd_open.c
+++ b/pidfd_open.c
@@ -10,7 +10,7 @@
 SYS_FUNC(pidfd_open)
 {
 	/* pid_t pid */
-	tprintf("%d", (int) tcp->u_arg[0]);
+	printpid(tcp, (int) tcp->u_arg[0], PT_TGID);
 
 	/* unsigned int flags */
 	tprintf(", %#x", (unsigned int) tcp->u_arg[1]);
diff --git a/print_fields.h b/print_fields.h
index f9714115..33d4a458 100644
--- a/print_fields.h
+++ b/print_fields.h
@@ -263,6 +263,30 @@
 		printfd((tcp_), (where_).field_);			\
 	} while (0)
 
+# define PRINT_FIELD_TID(prefix_, where_, field_, tcp_)			\
+	do {								\
+		STRACE_PRINTF("%s%s=", (prefix_), #field_);		\
+		printpid((tcp_), (where_).field_, PT_TID);			\
+	} while (0)
+
+# define PRINT_FIELD_TGID(prefix_, where_, field_, tcp_)			\
+	do {								\
+		STRACE_PRINTF("%s%s=", (prefix_), #field_);		\
+		printpid((tcp_), (where_).field_, PT_TGID);			\
+	} while (0)
+
+# define PRINT_FIELD_PGID(prefix_, where_, field_, tcp_)			\
+	do {								\
+		STRACE_PRINTF("%s%s=", (prefix_), #field_);		\
+		printpid((tcp_), (where_).field_, PT_PGID);			\
+	} while (0)
+
+# define PRINT_FIELD_SID(prefix_, where_, field_, tcp_)			\
+	do {								\
+		STRACE_PRINTF("%s%s=", (prefix_), #field_);		\
+		printpid((tcp_), (where_).field_, PT_SID);			\
+	} while (0)
+
 # define PRINT_FIELD_STRN(prefix_, where_, field_, len_, tcp_)		\
 	do {								\
 		STRACE_PRINTF("%s%s=", (prefix_), #field_);		\
diff --git a/printsiginfo.c b/printsiginfo.c
index 8ed1e7ba..cb4cde4a 100644
--- a/printsiginfo.c
+++ b/printsiginfo.c
@@ -58,7 +58,7 @@
 static void
 printsigsource(struct tcb *tcp, const siginfo_t *sip)
 {
-	PRINT_FIELD_D(", ", *sip, si_pid);
+	PRINT_FIELD_TGID(", ", *sip, si_pid, tcp);
 	PRINT_FIELD_UID(", ", *sip, si_uid);
 }
 
diff --git a/process.c b/process.c
index a98c304e..d6ff255d 100644
--- a/process.c
+++ b/process.c
@@ -92,7 +92,8 @@ SYS_FUNC(ptrace)
 		}
 
 		/* pid */
-		tprintf(", %d", pid);
+		tprints(", ");
+		printpid(tcp, pid, PT_TGID);
 
 		/* addr */
 		switch (request) {
diff --git a/process_vm.c b/process_vm.c
index abee1e68..50acb3fd 100644
--- a/process_vm.c
+++ b/process_vm.c
@@ -13,7 +13,8 @@ SYS_FUNC(process_vm_readv)
 {
 	if (entering(tcp)) {
 		/* arg 1: pid */
-		tprintf("%d, ", (int) tcp->u_arg[0]);
+		printpid(tcp, (int) tcp->u_arg[0], PT_TGID);
+		tprints(", ");
 	} else {
 		kernel_ulong_t local_iovcnt = tcp->u_arg[2];
 		kernel_ulong_t remote_iovcnt = tcp->u_arg[4];
@@ -42,7 +43,8 @@ SYS_FUNC(process_vm_writev)
 	kernel_ulong_t flags = tcp->u_arg[5];
 
 	/* arg 1: pid */
-	tprintf("%d, ", (int) tcp->u_arg[0]);
+	printpid(tcp, (int) tcp->u_arg[0], PT_TGID);
+	tprints(", ");
 	/* arg 2: local iov */
 	tprint_iov(tcp, local_iovcnt, tcp->u_arg[1], IOV_DECODE_STR);
 	/* arg 3: local iovcnt */
diff --git a/resource.c b/resource.c
index 53192ee9..bd21b748 100644
--- a/resource.c
+++ b/resource.c
@@ -142,7 +142,8 @@ SYS_FUNC(setrlimit)
 SYS_FUNC(prlimit64)
 {
 	if (entering(tcp)) {
-		tprintf("%d, ", (int) tcp->u_arg[0]);
+		printpid(tcp, (int) tcp->u_arg[0], PT_TGID);
+		tprints(", ");
 		printxval(resources, tcp->u_arg[1], "RLIMIT_???");
 		tprints(", ");
 		print_rlimit64(tcp, tcp->u_arg[2]);
@@ -179,10 +180,28 @@ SYS_FUNC(osf_getrusage)
 
 #include "xlat/priorities.h"
 
+static void
+priority_print_who(struct tcb *tcp, int which, int who)
+{
+	switch (which)
+	{
+	case PRIO_PROCESS:
+		printpid(tcp, who, PT_TGID);
+		break;
+	case PRIO_PGRP:
+		printpid(tcp, who, PT_PGID);
+		break;
+	default:
+		tprintf("%d", who);
+		break;
+	}
+}
+
 SYS_FUNC(getpriority)
 {
 	printxval(priorities, tcp->u_arg[0], "PRIO_???");
-	tprintf(", %d", (int) tcp->u_arg[1]);
+	tprints(", ");
+	priority_print_who(tcp, tcp->u_arg[0], tcp->u_arg[1]);
 
 	return RVAL_DECODED;
 }
@@ -190,7 +209,9 @@ SYS_FUNC(getpriority)
 SYS_FUNC(setpriority)
 {
 	printxval(priorities, tcp->u_arg[0], "PRIO_???");
-	tprintf(", %d, %d", (int) tcp->u_arg[1], (int) tcp->u_arg[2]);
+	tprints(", ");
+	priority_print_who(tcp, tcp->u_arg[0], tcp->u_arg[1]);
+	tprintf(", %d", (int) tcp->u_arg[2]);
 
 	return RVAL_DECODED;
 }
diff --git a/sched.c b/sched.c
index 788ef39b..7ae5abe2 100644
--- a/sched.c
+++ b/sched.c
@@ -21,7 +21,7 @@
 SYS_FUNC(sched_getscheduler)
 {
 	if (entering(tcp)) {
-		tprintf("%d", (int) tcp->u_arg[0]);
+		printpid(tcp, (int) tcp->u_arg[0], PT_TGID);
 	} else if (!syserror(tcp)) {
 		tcp->auxstr = xlookup(schedulers, (kernel_ulong_t) tcp->u_rval);
 		return RVAL_STR;
@@ -31,7 +31,8 @@ SYS_FUNC(sched_getscheduler)
 
 SYS_FUNC(sched_setscheduler)
 {
-	tprintf("%d, ", (int) tcp->u_arg[0]);
+	printpid(tcp, (int) tcp->u_arg[0], PT_TGID);
+	tprints(", ");
 	printxval(schedulers, tcp->u_arg[1], "SCHED_???");
 	tprints(", ");
 	printnum_int(tcp, tcp->u_arg[2], "%d");
@@ -41,16 +42,19 @@ SYS_FUNC(sched_setscheduler)
 
 SYS_FUNC(sched_getparam)
 {
-	if (entering(tcp))
-		tprintf("%d, ", (int) tcp->u_arg[0]);
-	else
+	if (entering(tcp)) {
+		printpid(tcp, (int) tcp->u_arg[0], PT_TGID);
+		tprints(", ");
+	} else {
 		printnum_int(tcp, tcp->u_arg[1], "%d");
+	}
 	return 0;
 }
 
 SYS_FUNC(sched_setparam)
 {
-	tprintf("%d, ", (int) tcp->u_arg[0]);
+	printpid(tcp, (int) tcp->u_arg[0], PT_TGID);
+	tprints(", ");
 	printnum_int(tcp, tcp->u_arg[1], "%d");
 
 	return RVAL_DECODED;
@@ -68,7 +72,8 @@ do_sched_rr_get_interval(struct tcb *const tcp,
 			 const print_obj_by_addr_fn print_ts)
 {
 	if (entering(tcp)) {
-		tprintf("%d, ", (int) tcp->u_arg[0]);
+		printpid(tcp, (int) tcp->u_arg[0], PT_TGID);
+		tprints(", ");
 	} else {
 		if (syserror(tcp))
 			printaddr(tcp->u_arg[1]);
@@ -160,7 +165,8 @@ end:
 SYS_FUNC(sched_setattr)
 {
 	if (entering(tcp)) {
-		tprintf("%d, ", (int) tcp->u_arg[0]);
+		printpid(tcp, (int) tcp->u_arg[0], PT_TGID);
+		tprints(", ");
 		print_sched_attr(tcp, tcp->u_arg[1], 0);
 	} else {
 		struct sched_attr attr;
@@ -179,7 +185,8 @@ SYS_FUNC(sched_setattr)
 SYS_FUNC(sched_getattr)
 {
 	if (entering(tcp)) {
-		tprintf("%d, ", (int) tcp->u_arg[0]);
+		printpid(tcp, (int) tcp->u_arg[0], PT_TGID);
+		tprints(", ");
 	} else {
 		const unsigned int size = tcp->u_arg[2];
 
diff --git a/signal.c b/signal.c
index 5f1acac6..50dd898c 100644
--- a/signal.c
+++ b/signal.c
@@ -439,7 +439,8 @@ SYS_FUNC(sigprocmask)
 SYS_FUNC(kill)
 {
 	/* pid */
-	tprintf("%d, ", (int) tcp->u_arg[0]);
+	printpid_tgid_pgid(tcp, tcp->u_arg[0]);
+	tprints(", ");
 	/* signal */
 	printsignal(tcp->u_arg[1]);
 
@@ -448,7 +449,7 @@ SYS_FUNC(kill)
 
 SYS_FUNC(tkill)
 {
-	tprintf("%d", (int) tcp->u_arg[0]);
+	printpid(tcp, (int) tcp->u_arg[0], PT_TID);
 	tprints(", ");
 	printsignal(tcp->u_arg[1]);
 
@@ -457,8 +458,12 @@ SYS_FUNC(tkill)
 
 SYS_FUNC(tgkill)
 {
-	/* tgid, tid */
-	tprintf("%d, %d, ", (int) tcp->u_arg[0], (int) tcp->u_arg[1]);
+	/* tgid */
+	printpid(tcp, (int) tcp->u_arg[0], PT_TGID);
+	tprints(", ");
+	/* tid */
+	printpid(tcp, (int) tcp->u_arg[1], PT_TID);
+	tprints(", ");
 	/* signal */
 	printsignal(tcp->u_arg[2]);
 
@@ -624,7 +629,8 @@ print_sigqueueinfo(struct tcb *const tcp, const int sig,
 
 SYS_FUNC(rt_sigqueueinfo)
 {
-	tprintf("%d, ", (int) tcp->u_arg[0]);
+	printpid(tcp, (int) tcp->u_arg[0], PT_TGID);
+	tprints(", ");
 	print_sigqueueinfo(tcp, tcp->u_arg[1], tcp->u_arg[2]);
 
 	return RVAL_DECODED;
@@ -632,7 +638,10 @@ SYS_FUNC(rt_sigqueueinfo)
 
 SYS_FUNC(rt_tgsigqueueinfo)
 {
-	tprintf("%d, %d, ", (int) tcp->u_arg[0], (int) tcp->u_arg[1]);
+	printpid(tcp, (int) tcp->u_arg[0], PT_TGID);
+	tprints(", ");
+	printpid(tcp, (int) tcp->u_arg[1], PT_TID);
+	tprints(", ");
 	print_sigqueueinfo(tcp, tcp->u_arg[2], tcp->u_arg[3]);
 
 	return RVAL_DECODED;
diff --git a/sockaddr.c b/sockaddr.c
index b0046331..fb8887c2 100644
--- a/sockaddr.c
+++ b/sockaddr.c
@@ -416,7 +416,7 @@ print_sockaddr_data_nl(struct tcb *tcp, const void *const buf, const int addrlen
 {
 	const struct sockaddr_nl *const sa_nl = buf;
 
-	PRINT_FIELD_D("", *sa_nl, nl_pid);
+	PRINT_FIELD_TGID("", *sa_nl, nl_pid, tcp);
 	PRINT_FIELD_0X(", ", *sa_nl, nl_groups);
 }
 
diff --git a/tests/kcmp.c b/tests/kcmp.c
index a46da0ed..dc5ba9a4 100644
--- a/tests/kcmp.c
+++ b/tests/kcmp.c
@@ -64,7 +64,26 @@ static const char zero_path[] = "/dev/zero";
 static void
 printpidfd(const char *prefix, pid_t pid, unsigned fd)
 {
-	printf("%s%d", prefix, fd);
+	const char *path = NULL;
+
+# if VERBOSE_FD
+	if (pid == getpid()) {
+		switch (fd)
+		{
+		case NULL_FD:
+			path = null_path;
+			break;
+		case ZERO_FD:
+			path = zero_path;
+			break;
+		}
+	}
+# endif
+
+	if (path)
+		printf("%s%d<%s>", prefix, fd, path);
+	else
+		printf("%s%d", prefix, fd);
 }
 
 /*
@@ -179,7 +198,7 @@ main(void)
 	/* KCMP_FILE is the only type which has additional args */
 	do_kcmp(3141592653U, 2718281828U, ARG_STR(KCMP_FILE), bogus_idx1,
 		bogus_idx2);
-	do_kcmp(-1, -1, ARG_STR(KCMP_FILE), NULL_FD, ZERO_FD);
+	do_kcmp(getpid(), getpid(), ARG_STR(KCMP_FILE), NULL_FD, ZERO_FD);
 
 	/* Types without additional args */
 	do_kcmp(-1, -1, ARG_STR(KCMP_VM), bogus_idx1, bogus_idx2);
@@ -198,7 +217,7 @@ main(void)
 	for (i = 0; i < ARRAY_SIZE(slot_data); i++) {
 		memcpy(slot, slot_data + i, sizeof(*slot));
 
-		do_kcmp(getpid(), getppid(), ARG_STR(KCMP_EPOLL_TFD), NULL_FD,
+		do_kcmp(getpid(), -1, ARG_STR(KCMP_EPOLL_TFD), NULL_FD,
 			(uintptr_t) slot, 1);
 	}
 
diff --git a/util.c b/util.c
index 286c6903..094e5818 100644
--- a/util.c
+++ b/util.c
@@ -392,6 +392,18 @@ printnum_fd(struct tcb *const tcp, const kernel_ulong_t addr)
 	return true;
 }
 
+bool
+printnum_pid(struct tcb *const tcp, const kernel_ulong_t addr, enum pid_type type)
+{
+	int pid;
+	if (umove_or_printaddr(tcp, addr, &pid))
+		return false;
+	tprints("[");
+	printpid(tcp, pid, type);
+	tprints("]");
+	return true;
+}
+
 /**
  * Prints time to a (static internal) buffer and returns pointer to it.
  * Returns NULL if the provided time specification is not correct.
@@ -641,12 +653,8 @@ printed:
 void
 printfd_pid_tracee_ns(struct tcb *tcp, pid_t pid, int fd)
 {
-	/*
-	 * TODO: We want to have the same formatting as printfd here,
-	 *       but we should figure out first which process in strace's
-	 *       PID NS is referred to by pid in tracee's PID NS.
-	 */
-	tprintf("%d", fd);
+	int strace_pid = translate_pid(tcp, pid, PT_TGID, NULL);
+	printfd_pid(tcp, strace_pid, fd);
 }
 
 /*
diff --git a/wait.c b/wait.c
index 2b9f9807..997a711a 100644
--- a/wait.c
+++ b/wait.c
@@ -80,14 +80,8 @@ printwaitn(struct tcb *const tcp,
 	   void (*const print_rusage)(struct tcb *, kernel_ulong_t))
 {
 	if (entering(tcp)) {
-		/* On Linux, kernel-side pid_t is typedef'ed to int
-		 * on all arches. Also, glibc-2.8 truncates wait3 and wait4
-		 * pid argument to int on 64bit arches, producing,
-		 * for example, wait4(4294967295, ...) instead of -1
-		 * in strace. We have to use int here, not long.
-		 */
-		int pid = tcp->u_arg[0];
-		tprintf("%d, ", pid);
+		printpid_tgid_pgid(tcp, tcp->u_arg[0]);
+		tprintf(", ");
 	} else {
 		int status;
 
@@ -108,7 +102,7 @@ printwaitn(struct tcb *const tcp,
 				printaddr(tcp->u_arg[3]);
 		}
 	}
-	return 0;
+	return RVAL_TGID;
 }
 
 SYS_FUNC(waitpid)
@@ -134,10 +128,28 @@ SYS_FUNC(osf_wait4)
 
 SYS_FUNC(waitid)
 {
+	unsigned int idtype = (unsigned int) tcp->u_arg[0];
+	int id = (int) tcp->u_arg[1];
+
 	if (entering(tcp)) {
-		printxval(waitid_types, tcp->u_arg[0], "P_???");
-		int pid = tcp->u_arg[1];
-		tprintf(", %d, ", pid);
+		printxval(waitid_types, idtype, "P_???");
+		tprints(", ");
+		switch (idtype)
+		{
+		case P_PID:
+			printpid(tcp, id, PT_TGID);
+			break;
+		case P_PIDFD:
+			printfd(tcp, id);
+			break;
+		case P_PGID:
+			printpid(tcp, id, PT_PGID);
+			break;
+		default:
+			tprintf("%d", id);
+			break;
+		}
+		tprints(", ");
 	} else {
 		/* siginfo */
 		printsiginfo_at(tcp, tcp->u_arg[2]);
-- 
2.27.0


From ldv at altlinux.org  Mon Aug  3 21:43:27 2020
From: ldv at altlinux.org (Dmitry V. Levin)
Date: Tue, 4 Aug 2020 00:43:27 +0300
Subject: [PATCH v5 1/5] PID namespace translation support
In-Reply-To: <20200803191916.94724-2-uzonyi.akos@gmail.com>
References: <20200803191916.94724-1-uzonyi.akos@gmail.com>
 <20200803191916.94724-2-uzonyi.akos@gmail.com>
Message-ID: <20200803214326.GB7849@altlinux.org>

On Mon, Aug 03, 2020 at 09:19:12PM +0200, ?kos Uzonyi wrote:
[...]
> +void
> +pidns_init(void)
> +{
> +	if (proc_data_cache)
> +		return;
> +
> +	pid_max = INT_MAX;
> +	if (read_int_from_file("/proc/sys/kernel/pid_max", &pid_max) < 0)
> +		debug_func_perror_msg("reading /proc/sys/kernel/pid_max");
> +	pid_max_size = ilog2_32(pid_max - 1) + 1;
> +	pid_max_size_lg = ilog2_32(pid_max_size - 1) + 1;
> +
> +	for (int i = 0; i < PT_COUNT; i++)
> +		ns_pid_to_proc_pid[i] = trie_create(64, ptr_sz_lg, 10, 10, 0);

Has the numeric constant 64 been chosen because
sizeof(struct tcb.pid_ns) * 8 == 64?

> +
> +	proc_data_cache = trie_create(pid_max_size, ptr_sz_lg, 10, 10, 0);
> +}
> +
> +static void
> +put_proc_pid(uint64_t ns, int ns_pid, enum pid_type type, int proc_pid)
> +{
> +	struct trie *b = (struct trie *) (uintptr_t) trie_get(ns_pid_to_proc_pid[type], ns);
> +	if (!b) {
> +		b = trie_create(pid_max_size, pid_max_size_lg, 10, 10, 0);
> +		trie_set(ns_pid_to_proc_pid[type], ns, (uint64_t) (uintptr_t) b);
> +	}
> +	trie_set(b, ns_pid, proc_pid);
> +}

In all three cases trie_create is invoked with node_key_bits
and data_block_key_bits arguments equal to 10.

Could you shed some light on the choice of this numeric constant, please?


-- 
ldv

From jojokoo1111 at protonmail.com  Tue Aug  4 05:13:17 2020
From: jojokoo1111 at protonmail.com (jojokoo1111)
Date: Tue, 04 Aug 2020 05:13:17 +0000
Subject: How does strace distinguishes between syscall-exit-stop or
 syscall-enter-stop in ARM LINUX ?
Message-ID: <S3nNQgnKhA0QUDv-HWKIyOjug7oSW2RQ9FU_l2ljS9Vz2l-xwNzJsRlLbld15pMfiNatx8-gSQAwo3vsnvElF7dv3eknP38GqG_z7A-cSGw=@protonmail.com>

I didn't find the piece of code in strace that distinguishes when using PTRACE_SYSCALL if the state is syscall-exit-stop or syscall-enter-stop in ARM LINUX .

If it is new kenel we can use PTRACE_GET_SYSCALL_INFO , but how does strace find that information out if it is older kernel?
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From jojokoo1111 at protonmail.com  Tue Aug  4 05:11:03 2020
From: jojokoo1111 at protonmail.com (jojokoo1111)
Date: Tue, 04 Aug 2020 05:11:03 +0000
Subject: test
Message-ID: <vXrNwvz1dVOTHcbGKnXL4kOOITyNHR6XUEgIIzSg5VNvzoxAWdWUAx0H-Uud8c7CMxHElNPGVqIOOSrTRMJwsHvuMGVHDy8oiUST2xzc2wU=@protonmail.com>

sss
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From uzonyi.akos at gmail.com  Tue Aug  4 17:52:46 2020
From: uzonyi.akos at gmail.com (=?UTF-8?B?w4Frb3MgVXpvbnlp?=)
Date: Tue, 4 Aug 2020 19:52:46 +0200
Subject: [PATCH v5 1/5] PID namespace translation support
In-Reply-To: <20200803214326.GB7849@altlinux.org>
References: <20200803191916.94724-1-uzonyi.akos@gmail.com>
 <20200803191916.94724-2-uzonyi.akos@gmail.com>
 <20200803214326.GB7849@altlinux.org>
Message-ID: <CAJrAtOVnPU+pbpM1h4hybfU-PzMQF_cjMiUgQwySfb6WRjsqqQ@mail.gmail.com>

On Mon, 3 Aug 2020 at 23:43, Dmitry V. Levin <ldv at altlinux.org> wrote:
> On Mon, Aug 03, 2020 at 09:19:12PM +0200, ?kos Uzonyi wrote:
> [...]
> > +void
> > +pidns_init(void)
> > +{
> > +     if (proc_data_cache)
> > +             return;
> > +
> > +     pid_max = INT_MAX;
> > +     if (read_int_from_file("/proc/sys/kernel/pid_max", &pid_max) < 0)
> > +             debug_func_perror_msg("reading /proc/sys/kernel/pid_max");
> > +     pid_max_size = ilog2_32(pid_max - 1) + 1;
> > +     pid_max_size_lg = ilog2_32(pid_max_size - 1) + 1;
> > +
> > +     for (int i = 0; i < PT_COUNT; i++)
> > +             ns_pid_to_proc_pid[i] = trie_create(64, ptr_sz_lg, 10, 10, 0);
>
> Has the numeric constant 64 been chosen because
> sizeof(struct tcb.pid_ns) * 8 == 64?

Yes.
For making it clear in the code, which one would be preferred?
- Using a named constant
- Using the expression you wrote above
- Adding a comment about it

> > +
> > +     proc_data_cache = trie_create(pid_max_size, ptr_sz_lg, 10, 10, 0);
> > +}
> > +
> > +static void
> > +put_proc_pid(uint64_t ns, int ns_pid, enum pid_type type, int proc_pid)
> > +{
> > +     struct trie *b = (struct trie *) (uintptr_t) trie_get(ns_pid_to_proc_pid[type], ns);
> > +     if (!b) {
> > +             b = trie_create(pid_max_size, pid_max_size_lg, 10, 10, 0);
> > +             trie_set(ns_pid_to_proc_pid[type], ns, (uint64_t) (uintptr_t) b);
> > +     }
> > +     trie_set(b, ns_pid, proc_pid);
> > +}
>
> In all three cases trie_create is invoked with node_key_bits
> and data_block_key_bits arguments equal to 10.
>
> Could you shed some light on the choice of this numeric constant, please?

Unfortunately, I have no strong reason why 10 was chosen. It's just a
number that seemed to be ok. But thinking a bit more about it, I
realized maybe a smaller number would be better. 10 means node size is
8KB (with 8 byte pointers), which seems to be a lot of memory usage,
as PIDs are sparse. Maybe for example 4 could be a better choice, so
nodes are small, and lookup times are still not that bad. But I'm
still not sure what explanation could I write to the chosen constant.

From ldv at altlinux.org  Tue Aug  4 22:31:31 2020
From: ldv at altlinux.org (Dmitry V. Levin)
Date: Wed, 5 Aug 2020 01:31:31 +0300
Subject: [PATCH v5 1/5] PID namespace translation support
In-Reply-To: <CAJrAtOVnPU+pbpM1h4hybfU-PzMQF_cjMiUgQwySfb6WRjsqqQ@mail.gmail.com>
References: <20200803191916.94724-1-uzonyi.akos@gmail.com>
 <20200803191916.94724-2-uzonyi.akos@gmail.com>
 <20200803214326.GB7849@altlinux.org>
 <CAJrAtOVnPU+pbpM1h4hybfU-PzMQF_cjMiUgQwySfb6WRjsqqQ@mail.gmail.com>
Message-ID: <20200804223131.GA25142@altlinux.org>

On Tue, Aug 04, 2020 at 07:52:46PM +0200, ?kos Uzonyi wrote:
> On Mon, 3 Aug 2020 at 23:43, Dmitry V. Levin <ldv at altlinux.org> wrote:
> > On Mon, Aug 03, 2020 at 09:19:12PM +0200, ?kos Uzonyi wrote:
> > [...]
> > > +void
> > > +pidns_init(void)
> > > +{
> > > +     if (proc_data_cache)
> > > +             return;
> > > +
> > > +     pid_max = INT_MAX;
> > > +     if (read_int_from_file("/proc/sys/kernel/pid_max", &pid_max) < 0)
> > > +             debug_func_perror_msg("reading /proc/sys/kernel/pid_max");
> > > +     pid_max_size = ilog2_32(pid_max - 1) + 1;
> > > +     pid_max_size_lg = ilog2_32(pid_max_size - 1) + 1;
> > > +
> > > +     for (int i = 0; i < PT_COUNT; i++)
> > > +             ns_pid_to_proc_pid[i] = trie_create(64, ptr_sz_lg, 10, 10, 0);
> >
> > Has the numeric constant 64 been chosen because
> > sizeof(struct tcb.pid_ns) * 8 == 64?
> 
> Yes.
> For making it clear in the code, which one would be preferred?
> - Using a named constant

It's always nice to have a good name for a constant.

> - Using the expression you wrote above

Strictly speaking, that was not a valid C expression, but
	sizeof_field(struct tcb, pid_ns) * 8
is a valid one.

> - Adding a comment about it
> 
> > > +
> > > +     proc_data_cache = trie_create(pid_max_size, ptr_sz_lg, 10, 10, 0);
> > > +}
> > > +
> > > +static void
> > > +put_proc_pid(uint64_t ns, int ns_pid, enum pid_type type, int proc_pid)
> > > +{
> > > +     struct trie *b = (struct trie *) (uintptr_t) trie_get(ns_pid_to_proc_pid[type], ns);
> > > +     if (!b) {
> > > +             b = trie_create(pid_max_size, pid_max_size_lg, 10, 10, 0);
> > > +             trie_set(ns_pid_to_proc_pid[type], ns, (uint64_t) (uintptr_t) b);
> > > +     }
> > > +     trie_set(b, ns_pid, proc_pid);
> > > +}
> >
> > In all three cases trie_create is invoked with node_key_bits
> > and data_block_key_bits arguments equal to 10.
> >
> > Could you shed some light on the choice of this numeric constant, please?
> 
> Unfortunately, I have no strong reason why 10 was chosen. It's just a
> number that seemed to be ok. But thinking a bit more about it, I
> realized maybe a smaller number would be better. 10 means node size is
> 8KB (with 8 byte pointers), which seems to be a lot of memory usage,

Should the number depend on the size of pointer then?
Or should it depend on pid_max?

> as PIDs are sparse.

What do you mean by that?

> Maybe for example 4 could be a better choice, so
> nodes are small, and lookup times are still not that bad. But I'm
> still not sure what explanation could I write to the chosen constant.

Even if it just feels right, try to explain in the comment why it feels right.


-- 
ldv

From uzonyi.akos at gmail.com  Tue Aug  4 23:53:37 2020
From: uzonyi.akos at gmail.com (=?UTF-8?B?w4Frb3MgVXpvbnlp?=)
Date: Wed, 5 Aug 2020 01:53:37 +0200
Subject: [PATCH v5 1/5] PID namespace translation support
In-Reply-To: <20200804223131.GA25142@altlinux.org>
References: <20200803191916.94724-1-uzonyi.akos@gmail.com>
 <20200803191916.94724-2-uzonyi.akos@gmail.com>
 <20200803214326.GB7849@altlinux.org>
 <CAJrAtOVnPU+pbpM1h4hybfU-PzMQF_cjMiUgQwySfb6WRjsqqQ@mail.gmail.com>
 <20200804223131.GA25142@altlinux.org>
Message-ID: <CAJrAtOX+rOLV1o_kc1t_J3zFboF6PWBcmy2BThr9XnWpkRHZFA@mail.gmail.com>

On Wed, 5 Aug 2020 at 00:31, Dmitry V. Levin <ldv at altlinux.org> wrote:
> On Tue, Aug 04, 2020 at 07:52:46PM +0200, ?kos Uzonyi wrote:
> > On Mon, 3 Aug 2020 at 23:43, Dmitry V. Levin <ldv at altlinux.org> wrote:
> > > On Mon, Aug 03, 2020 at 09:19:12PM +0200, ?kos Uzonyi wrote:
> > > [...]
> > > > +void
> > > > +pidns_init(void)
> > > > +{
> > > > +     if (proc_data_cache)
> > > > +             return;
> > > > +
> > > > +     pid_max = INT_MAX;
> > > > +     if (read_int_from_file("/proc/sys/kernel/pid_max", &pid_max) < 0)
> > > > +             debug_func_perror_msg("reading /proc/sys/kernel/pid_max");
> > > > +     pid_max_size = ilog2_32(pid_max - 1) + 1;
> > > > +     pid_max_size_lg = ilog2_32(pid_max_size - 1) + 1;
> > > > +
> > > > +     for (int i = 0; i < PT_COUNT; i++)
> > > > +             ns_pid_to_proc_pid[i] = trie_create(64, ptr_sz_lg, 10, 10, 0);
> > >
> > > Has the numeric constant 64 been chosen because
> > > sizeof(struct tcb.pid_ns) * 8 == 64?
> >
> > Yes.
> > For making it clear in the code, which one would be preferred?
> > - Using a named constant
>
> It's always nice to have a good name for a constant.
>
> > - Using the expression you wrote above
>
> Strictly speaking, that was not a valid C expression, but
>         sizeof_field(struct tcb, pid_ns) * 8
> is a valid one.

As tcb.pid_ns is just one of the variables where ns ids are stored, I
might prefer using sizeof(uint64_t):
#define NS_ID_SIZE sizeof(uint64_t)
or maybe just simply:
#define NS_ID_SIZE 64

> > - Adding a comment about it
> >
> > > > +
> > > > +     proc_data_cache = trie_create(pid_max_size, ptr_sz_lg, 10, 10, 0);
> > > > +}
> > > > +
> > > > +static void
> > > > +put_proc_pid(uint64_t ns, int ns_pid, enum pid_type type, int proc_pid)
> > > > +{
> > > > +     struct trie *b = (struct trie *) (uintptr_t) trie_get(ns_pid_to_proc_pid[type], ns);
> > > > +     if (!b) {
> > > > +             b = trie_create(pid_max_size, pid_max_size_lg, 10, 10, 0);
> > > > +             trie_set(ns_pid_to_proc_pid[type], ns, (uint64_t) (uintptr_t) b);
> > > > +     }
> > > > +     trie_set(b, ns_pid, proc_pid);
> > > > +}
> > >
> > > In all three cases trie_create is invoked with node_key_bits
> > > and data_block_key_bits arguments equal to 10.
> > >
> > > Could you shed some light on the choice of this numeric constant, please?
> >
> > Unfortunately, I have no strong reason why 10 was chosen. It's just a
> > number that seemed to be ok. But thinking a bit more about it, I
> > realized maybe a smaller number would be better. 10 means node size is
> > 8KB (with 8 byte pointers), which seems to be a lot of memory usage,
>
> Should the number depend on the size of pointer then?
> Or should it depend on pid_max?

I think it's easier to use a constant.

> > as PIDs are sparse.
>
> What do you mean by that?

I just meant that usually a few pids are distributed over a large
interval, so it's a waste allocating large nodes, as usually only a
few pointers will be used in them.

> > Maybe for example 4 could be a better choice, so
> > nodes are small, and lookup times are still not that bad. But I'm
> > still not sure what explanation could I write to the chosen constant.
>
> Even if it just feels right, try to explain in the comment why it feels right.

OK, I'll try to come up with something.

From ldv at altlinux.org  Wed Aug  5 00:02:58 2020
From: ldv at altlinux.org (Dmitry V. Levin)
Date: Wed, 5 Aug 2020 03:02:58 +0300
Subject: [PATCH v5 1/5] PID namespace translation support
In-Reply-To: <CAJrAtOX+rOLV1o_kc1t_J3zFboF6PWBcmy2BThr9XnWpkRHZFA@mail.gmail.com>
References: <20200803191916.94724-1-uzonyi.akos@gmail.com>
 <20200803191916.94724-2-uzonyi.akos@gmail.com>
 <20200803214326.GB7849@altlinux.org>
 <CAJrAtOVnPU+pbpM1h4hybfU-PzMQF_cjMiUgQwySfb6WRjsqqQ@mail.gmail.com>
 <20200804223131.GA25142@altlinux.org>
 <CAJrAtOX+rOLV1o_kc1t_J3zFboF6PWBcmy2BThr9XnWpkRHZFA@mail.gmail.com>
Message-ID: <20200805000258.GA25963@altlinux.org>

On Wed, Aug 05, 2020 at 01:53:37AM +0200, ?kos Uzonyi wrote:
> On Wed, 5 Aug 2020 at 00:31, Dmitry V. Levin <ldv at altlinux.org> wrote:
> > On Tue, Aug 04, 2020 at 07:52:46PM +0200, ?kos Uzonyi wrote:
> > > On Mon, 3 Aug 2020 at 23:43, Dmitry V. Levin <ldv at altlinux.org> wrote:
> > > > On Mon, Aug 03, 2020 at 09:19:12PM +0200, ?kos Uzonyi wrote:
> > > > [...]
> > > > > +void
> > > > > +pidns_init(void)
> > > > > +{
> > > > > +     if (proc_data_cache)
> > > > > +             return;
> > > > > +
> > > > > +     pid_max = INT_MAX;
> > > > > +     if (read_int_from_file("/proc/sys/kernel/pid_max", &pid_max) < 0)
> > > > > +             debug_func_perror_msg("reading /proc/sys/kernel/pid_max");
> > > > > +     pid_max_size = ilog2_32(pid_max - 1) + 1;
> > > > > +     pid_max_size_lg = ilog2_32(pid_max_size - 1) + 1;
> > > > > +
> > > > > +     for (int i = 0; i < PT_COUNT; i++)
> > > > > +             ns_pid_to_proc_pid[i] = trie_create(64, ptr_sz_lg, 10, 10, 0);
> > > >
> > > > Has the numeric constant 64 been chosen because
> > > > sizeof(struct tcb.pid_ns) * 8 == 64?
> > >
> > > Yes.
> > > For making it clear in the code, which one would be preferred?
> > > - Using a named constant
> >
> > It's always nice to have a good name for a constant.
> >
> > > - Using the expression you wrote above
> >
> > Strictly speaking, that was not a valid C expression, but
> >         sizeof_field(struct tcb, pid_ns) * 8
> > is a valid one.
> 
> As tcb.pid_ns is just one of the variables where ns ids are stored, I
> might prefer using sizeof(uint64_t):
> #define NS_ID_SIZE sizeof(uint64_t)
> or maybe just simply:
> #define NS_ID_SIZE 64

By the way, is it really 64?  Yes, the type of struct tcb.pid_ns is 64-bit,
but any valid pid_ns is 32-bit.


-- 
ldv

From uzonyi.akos at gmail.com  Wed Aug  5 00:14:36 2020
From: uzonyi.akos at gmail.com (=?UTF-8?B?w4Frb3MgVXpvbnlp?=)
Date: Wed, 5 Aug 2020 02:14:36 +0200
Subject: [PATCH v5 1/5] PID namespace translation support
In-Reply-To: <20200805000258.GA25963@altlinux.org>
References: <20200803191916.94724-1-uzonyi.akos@gmail.com>
 <20200803191916.94724-2-uzonyi.akos@gmail.com>
 <20200803214326.GB7849@altlinux.org>
 <CAJrAtOVnPU+pbpM1h4hybfU-PzMQF_cjMiUgQwySfb6WRjsqqQ@mail.gmail.com>
 <20200804223131.GA25142@altlinux.org>
 <CAJrAtOX+rOLV1o_kc1t_J3zFboF6PWBcmy2BThr9XnWpkRHZFA@mail.gmail.com>
 <20200805000258.GA25963@altlinux.org>
Message-ID: <CAJrAtOVUFPSxxX+cFThNbjaj6Cyd5nAP95sFS41BYSbNDYbpHA@mail.gmail.com>

On Wed, 5 Aug 2020 at 02:02, Dmitry V. Levin <ldv at altlinux.org> wrote:
> On Wed, Aug 05, 2020 at 01:53:37AM +0200, ?kos Uzonyi wrote:
> > On Wed, 5 Aug 2020 at 00:31, Dmitry V. Levin <ldv at altlinux.org> wrote:
> > > On Tue, Aug 04, 2020 at 07:52:46PM +0200, ?kos Uzonyi wrote:
> > > > On Mon, 3 Aug 2020 at 23:43, Dmitry V. Levin <ldv at altlinux.org> wrote:
> > > > > On Mon, Aug 03, 2020 at 09:19:12PM +0200, ?kos Uzonyi wrote:
> > > > > [...]
> > > > > > +void
> > > > > > +pidns_init(void)
> > > > > > +{
> > > > > > +     if (proc_data_cache)
> > > > > > +             return;
> > > > > > +
> > > > > > +     pid_max = INT_MAX;
> > > > > > +     if (read_int_from_file("/proc/sys/kernel/pid_max", &pid_max) < 0)
> > > > > > +             debug_func_perror_msg("reading /proc/sys/kernel/pid_max");
> > > > > > +     pid_max_size = ilog2_32(pid_max - 1) + 1;
> > > > > > +     pid_max_size_lg = ilog2_32(pid_max_size - 1) + 1;
> > > > > > +
> > > > > > +     for (int i = 0; i < PT_COUNT; i++)
> > > > > > +             ns_pid_to_proc_pid[i] = trie_create(64, ptr_sz_lg, 10, 10, 0);
> > > > >
> > > > > Has the numeric constant 64 been chosen because
> > > > > sizeof(struct tcb.pid_ns) * 8 == 64?
> > > >
> > > > Yes.
> > > > For making it clear in the code, which one would be preferred?
> > > > - Using a named constant
> > >
> > > It's always nice to have a good name for a constant.
> > >
> > > > - Using the expression you wrote above
> > >
> > > Strictly speaking, that was not a valid C expression, but
> > >         sizeof_field(struct tcb, pid_ns) * 8
> > > is a valid one.
> >
> > As tcb.pid_ns is just one of the variables where ns ids are stored, I
> > might prefer using sizeof(uint64_t):
> > #define NS_ID_SIZE sizeof(uint64_t)
> > or maybe just simply:
> > #define NS_ID_SIZE 64
>
> By the way, is it really 64?  Yes, the type of struct tcb.pid_ns is 64-bit,
> but any valid pid_ns is 32-bit.

I think it was chosen to be 64 bit by Eugene, because it's not
documented that it should fit into 32 bit. The documentation only says
that it's derived from an inode number. Or is it guaranteed that inode
numbers are maximum 32 bit?

From ldv at altlinux.org  Wed Aug  5 00:30:55 2020
From: ldv at altlinux.org (Dmitry V. Levin)
Date: Wed, 5 Aug 2020 03:30:55 +0300
Subject: [PATCH v5 1/5] PID namespace translation support
In-Reply-To: <CAJrAtOVUFPSxxX+cFThNbjaj6Cyd5nAP95sFS41BYSbNDYbpHA@mail.gmail.com>
References: <20200803191916.94724-1-uzonyi.akos@gmail.com>
 <20200803191916.94724-2-uzonyi.akos@gmail.com>
 <20200803214326.GB7849@altlinux.org>
 <CAJrAtOVnPU+pbpM1h4hybfU-PzMQF_cjMiUgQwySfb6WRjsqqQ@mail.gmail.com>
 <20200804223131.GA25142@altlinux.org>
 <CAJrAtOX+rOLV1o_kc1t_J3zFboF6PWBcmy2BThr9XnWpkRHZFA@mail.gmail.com>
 <20200805000258.GA25963@altlinux.org>
 <CAJrAtOVUFPSxxX+cFThNbjaj6Cyd5nAP95sFS41BYSbNDYbpHA@mail.gmail.com>
Message-ID: <20200805003055.GA26447@altlinux.org>

On Wed, Aug 05, 2020 at 02:14:36AM +0200, ?kos Uzonyi wrote:
> On Wed, 5 Aug 2020 at 02:02, Dmitry V. Levin <ldv at altlinux.org> wrote:
> > On Wed, Aug 05, 2020 at 01:53:37AM +0200, ?kos Uzonyi wrote:
> > > On Wed, 5 Aug 2020 at 00:31, Dmitry V. Levin <ldv at altlinux.org> wrote:
> > > > On Tue, Aug 04, 2020 at 07:52:46PM +0200, ?kos Uzonyi wrote:
> > > > > On Mon, 3 Aug 2020 at 23:43, Dmitry V. Levin <ldv at altlinux.org> wrote:
> > > > > > On Mon, Aug 03, 2020 at 09:19:12PM +0200, ?kos Uzonyi wrote:
> > > > > > [...]
> > > > > > > +void
> > > > > > > +pidns_init(void)
> > > > > > > +{
> > > > > > > +     if (proc_data_cache)
> > > > > > > +             return;
> > > > > > > +
> > > > > > > +     pid_max = INT_MAX;
> > > > > > > +     if (read_int_from_file("/proc/sys/kernel/pid_max", &pid_max) < 0)
> > > > > > > +             debug_func_perror_msg("reading /proc/sys/kernel/pid_max");
> > > > > > > +     pid_max_size = ilog2_32(pid_max - 1) + 1;
> > > > > > > +     pid_max_size_lg = ilog2_32(pid_max_size - 1) + 1;
> > > > > > > +
> > > > > > > +     for (int i = 0; i < PT_COUNT; i++)
> > > > > > > +             ns_pid_to_proc_pid[i] = trie_create(64, ptr_sz_lg, 10, 10, 0);
> > > > > >
> > > > > > Has the numeric constant 64 been chosen because
> > > > > > sizeof(struct tcb.pid_ns) * 8 == 64?
> > > > >
> > > > > Yes.
> > > > > For making it clear in the code, which one would be preferred?
> > > > > - Using a named constant
> > > >
> > > > It's always nice to have a good name for a constant.
> > > >
> > > > > - Using the expression you wrote above
> > > >
> > > > Strictly speaking, that was not a valid C expression, but
> > > >         sizeof_field(struct tcb, pid_ns) * 8
> > > > is a valid one.
> > >
> > > As tcb.pid_ns is just one of the variables where ns ids are stored, I
> > > might prefer using sizeof(uint64_t):
> > > #define NS_ID_SIZE sizeof(uint64_t)
> > > or maybe just simply:
> > > #define NS_ID_SIZE 64
> >
> > By the way, is it really 64?  Yes, the type of struct tcb.pid_ns is 64-bit,
> > but any valid pid_ns is 32-bit.
> 
> I think it was chosen to be 64 bit by Eugene, because it's not
> documented that it should fit into 32 bit. The documentation only says
> that it's derived from an inode number. Or is it guaranteed that inode
> numbers are maximum 32 bit?

If I read the kernel correctly, pid_ns is assigned from struct ns_common.inum
of type unsigned int.


-- 
ldv

From uzonyi.akos at gmail.com  Wed Aug  5 08:45:28 2020
From: uzonyi.akos at gmail.com (=?UTF-8?B?w4Frb3MgVXpvbnlp?=)
Date: Wed, 5 Aug 2020 10:45:28 +0200
Subject: [PATCH v5 1/5] PID namespace translation support
In-Reply-To: <20200805003055.GA26447@altlinux.org>
References: <20200803191916.94724-1-uzonyi.akos@gmail.com>
 <20200803191916.94724-2-uzonyi.akos@gmail.com>
 <20200803214326.GB7849@altlinux.org>
 <CAJrAtOVnPU+pbpM1h4hybfU-PzMQF_cjMiUgQwySfb6WRjsqqQ@mail.gmail.com>
 <20200804223131.GA25142@altlinux.org>
 <CAJrAtOX+rOLV1o_kc1t_J3zFboF6PWBcmy2BThr9XnWpkRHZFA@mail.gmail.com>
 <20200805000258.GA25963@altlinux.org>
 <CAJrAtOVUFPSxxX+cFThNbjaj6Cyd5nAP95sFS41BYSbNDYbpHA@mail.gmail.com>
 <20200805003055.GA26447@altlinux.org>
Message-ID: <CAJrAtOVy4Mi=WMkVK5vtJnXqD-M3MXtXA84oSjttiH82CgTn+A@mail.gmail.com>

On Wed, 5 Aug 2020 at 02:30, Dmitry V. Levin <ldv at altlinux.org> wrote:
> On Wed, Aug 05, 2020 at 02:14:36AM +0200, ?kos Uzonyi wrote:
> > On Wed, 5 Aug 2020 at 02:02, Dmitry V. Levin <ldv at altlinux.org> wrote:
> > > On Wed, Aug 05, 2020 at 01:53:37AM +0200, ?kos Uzonyi wrote:
> > > > On Wed, 5 Aug 2020 at 00:31, Dmitry V. Levin <ldv at altlinux.org> wrote:
> > > > > On Tue, Aug 04, 2020 at 07:52:46PM +0200, ?kos Uzonyi wrote:
> > > > > > On Mon, 3 Aug 2020 at 23:43, Dmitry V. Levin <ldv at altlinux.org> wrote:
> > > > > > > On Mon, Aug 03, 2020 at 09:19:12PM +0200, ?kos Uzonyi wrote:
> > > > > > > [...]
> > > > > > > > +void
> > > > > > > > +pidns_init(void)
> > > > > > > > +{
> > > > > > > > +     if (proc_data_cache)
> > > > > > > > +             return;
> > > > > > > > +
> > > > > > > > +     pid_max = INT_MAX;
> > > > > > > > +     if (read_int_from_file("/proc/sys/kernel/pid_max", &pid_max) < 0)
> > > > > > > > +             debug_func_perror_msg("reading /proc/sys/kernel/pid_max");
> > > > > > > > +     pid_max_size = ilog2_32(pid_max - 1) + 1;
> > > > > > > > +     pid_max_size_lg = ilog2_32(pid_max_size - 1) + 1;
> > > > > > > > +
> > > > > > > > +     for (int i = 0; i < PT_COUNT; i++)
> > > > > > > > +             ns_pid_to_proc_pid[i] = trie_create(64, ptr_sz_lg, 10, 10, 0);
> > > > > > >
> > > > > > > Has the numeric constant 64 been chosen because
> > > > > > > sizeof(struct tcb.pid_ns) * 8 == 64?
> > > > > >
> > > > > > Yes.
> > > > > > For making it clear in the code, which one would be preferred?
> > > > > > - Using a named constant
> > > > >
> > > > > It's always nice to have a good name for a constant.
> > > > >
> > > > > > - Using the expression you wrote above
> > > > >
> > > > > Strictly speaking, that was not a valid C expression, but
> > > > >         sizeof_field(struct tcb, pid_ns) * 8
> > > > > is a valid one.
> > > >
> > > > As tcb.pid_ns is just one of the variables where ns ids are stored, I
> > > > might prefer using sizeof(uint64_t):
> > > > #define NS_ID_SIZE sizeof(uint64_t)
> > > > or maybe just simply:
> > > > #define NS_ID_SIZE 64
> > >
> > > By the way, is it really 64?  Yes, the type of struct tcb.pid_ns is 64-bit,
> > > but any valid pid_ns is 32-bit.
> >
> > I think it was chosen to be 64 bit by Eugene, because it's not
> > documented that it should fit into 32 bit. The documentation only says
> > that it's derived from an inode number. Or is it guaranteed that inode
> > numbers are maximum 32 bit?
>
> If I read the kernel correctly, pid_ns is assigned from struct ns_common.inum
> of type unsigned int.

Yes, I understand. However since it's not documented anywhere (AFAIK),
it might change later, isn't it? But if you say it's highly unlikely
to change, we can use unsigned int for ns id type. I think we should
not use -1U then for indicating error in tcb.pid_ns, as it is a likely
valid ns id. It's not a big problem however, as errors are unlikely,
so there is an option to just leave tcb.pid_ns 0 on error.

From ldv at altlinux.org  Wed Aug  5 09:52:39 2020
From: ldv at altlinux.org (Dmitry V. Levin)
Date: Wed, 5 Aug 2020 12:52:39 +0300
Subject: [PATCH v5 1/5] PID namespace translation support
In-Reply-To: <CAJrAtOVy4Mi=WMkVK5vtJnXqD-M3MXtXA84oSjttiH82CgTn+A@mail.gmail.com>
References: <20200803191916.94724-1-uzonyi.akos@gmail.com>
 <20200803191916.94724-2-uzonyi.akos@gmail.com>
 <20200803214326.GB7849@altlinux.org>
 <CAJrAtOVnPU+pbpM1h4hybfU-PzMQF_cjMiUgQwySfb6WRjsqqQ@mail.gmail.com>
 <20200804223131.GA25142@altlinux.org>
 <CAJrAtOX+rOLV1o_kc1t_J3zFboF6PWBcmy2BThr9XnWpkRHZFA@mail.gmail.com>
 <20200805000258.GA25963@altlinux.org>
 <CAJrAtOVUFPSxxX+cFThNbjaj6Cyd5nAP95sFS41BYSbNDYbpHA@mail.gmail.com>
 <20200805003055.GA26447@altlinux.org>
 <CAJrAtOVy4Mi=WMkVK5vtJnXqD-M3MXtXA84oSjttiH82CgTn+A@mail.gmail.com>
Message-ID: <20200805095239.GB27875@altlinux.org>

On Wed, Aug 05, 2020 at 10:45:28AM +0200, ?kos Uzonyi wrote:
> On Wed, 5 Aug 2020 at 02:30, Dmitry V. Levin <ldv at altlinux.org> wrote:
> > On Wed, Aug 05, 2020 at 02:14:36AM +0200, ?kos Uzonyi wrote:
> > > On Wed, 5 Aug 2020 at 02:02, Dmitry V. Levin <ldv at altlinux.org> wrote:
> > > > On Wed, Aug 05, 2020 at 01:53:37AM +0200, ?kos Uzonyi wrote:
> > > > > On Wed, 5 Aug 2020 at 00:31, Dmitry V. Levin <ldv at altlinux.org> wrote:
> > > > > > On Tue, Aug 04, 2020 at 07:52:46PM +0200, ?kos Uzonyi wrote:
> > > > > > > On Mon, 3 Aug 2020 at 23:43, Dmitry V. Levin <ldv at altlinux.org> wrote:
> > > > > > > > On Mon, Aug 03, 2020 at 09:19:12PM +0200, ?kos Uzonyi wrote:
> > > > > > > > [...]
> > > > > > > > > +void
> > > > > > > > > +pidns_init(void)
> > > > > > > > > +{
> > > > > > > > > +     if (proc_data_cache)
> > > > > > > > > +             return;
> > > > > > > > > +
> > > > > > > > > +     pid_max = INT_MAX;
> > > > > > > > > +     if (read_int_from_file("/proc/sys/kernel/pid_max", &pid_max) < 0)
> > > > > > > > > +             debug_func_perror_msg("reading /proc/sys/kernel/pid_max");
> > > > > > > > > +     pid_max_size = ilog2_32(pid_max - 1) + 1;
> > > > > > > > > +     pid_max_size_lg = ilog2_32(pid_max_size - 1) + 1;
> > > > > > > > > +
> > > > > > > > > +     for (int i = 0; i < PT_COUNT; i++)
> > > > > > > > > +             ns_pid_to_proc_pid[i] = trie_create(64, ptr_sz_lg, 10, 10, 0);
> > > > > > > >
> > > > > > > > Has the numeric constant 64 been chosen because
> > > > > > > > sizeof(struct tcb.pid_ns) * 8 == 64?
> > > > > > >
> > > > > > > Yes.
> > > > > > > For making it clear in the code, which one would be preferred?
> > > > > > > - Using a named constant
> > > > > >
> > > > > > It's always nice to have a good name for a constant.
> > > > > >
> > > > > > > - Using the expression you wrote above
> > > > > >
> > > > > > Strictly speaking, that was not a valid C expression, but
> > > > > >         sizeof_field(struct tcb, pid_ns) * 8
> > > > > > is a valid one.
> > > > >
> > > > > As tcb.pid_ns is just one of the variables where ns ids are stored, I
> > > > > might prefer using sizeof(uint64_t):
> > > > > #define NS_ID_SIZE sizeof(uint64_t)
> > > > > or maybe just simply:
> > > > > #define NS_ID_SIZE 64
> > > >
> > > > By the way, is it really 64?  Yes, the type of struct tcb.pid_ns is 64-bit,
> > > > but any valid pid_ns is 32-bit.
> > >
> > > I think it was chosen to be 64 bit by Eugene, because it's not
> > > documented that it should fit into 32 bit. The documentation only says
> > > that it's derived from an inode number. Or is it guaranteed that inode
> > > numbers are maximum 32 bit?
> >
> > If I read the kernel correctly, pid_ns is assigned from struct ns_common.inum
> > of type unsigned int.
> 
> Yes, I understand. However since it's not documented anywhere (AFAIK),
> it might change later, isn't it? But if you say it's highly unlikely
> to change, we can use unsigned int for ns id type. I think we should
> not use -1U then for indicating error in tcb.pid_ns, as it is a likely
> valid ns id. It's not a big problem however, as errors are unlikely,
> so there is an option to just leave tcb.pid_ns 0 on error.

Yes, I agree, -1U shouldn't be used as an error indicator.


-- 
ldv

From ldv at altlinux.org  Thu Aug  6 18:29:30 2020
From: ldv at altlinux.org (Dmitry V. Levin)
Date: Thu, 6 Aug 2020 21:29:30 +0300
Subject: strace 5.8 released
Message-ID: <20200806182929.GA22121@altlinux.org>

Starting with version 4.13, strace follows the schedule of linux kernel
and new versions of strace are released along with new versions of linux
kernel, so strace 5.8 is tagged and uploaded.

$ git tag -v v5.8 2> /dev/null | sed -n '/^$/,$p'

Noteworthy changes in strace 5.8 (2020-08-06)
=============================================

* Changes in behaviour
  * Modified %process class to contain system calls associated with
    process lifecycle (creation, exec, termination):
    kill, tkill, tgkill, pidfd_send_signal and rt_sigqueueinfo are added,
    arch_prctl and unshare are removed.

* Improvements
  * Implemented decoding of faccessat2 syscall.
  * Implemented decoding of LOOP_CONFIGURE ioctl command.
  * Updated decoding of io_uring_setup syscall to match Linux 5.8.
  * Updated lists of AUDIT_*, BPF_*, CAP_*, ETH_*, INET_DIAG_*, IORING_*,
    KEYCTL_*, KVM_*, LOOP_*, NDA_*, RTC_*, TCA_*, STATX_*, and *_MAGIC
    constants.
  * Updated lists of ioctl commands from Linux 5.8.

* Bug fixes
  * Added statx syscall to %fstat trace class.

Contributors
============

This release was made possible by the contributions of many people.
The maintainers are grateful to everyone who has contributed
changes or bug reports.  These include:

* Chris Packham
* Dmitry V. Levin
* Eugene Syromyatnikov
* Gleb Fotengauer-Malinovskiy
* Janosch Frank
* Steve Langasek
* Sven Schnelle
* ?kos Uzonyi

Please refer to the CREDITS file for the full list of strace contributors.


-- 
ldv
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From uzonyi.akos at gmail.com  Thu Aug  6 19:02:06 2020
From: uzonyi.akos at gmail.com (=?UTF-8?q?=C3=81kos=20Uzonyi?=)
Date: Thu,  6 Aug 2020 21:02:06 +0200
Subject: [PATCH v6 0/5] [PIDNS] Final
Message-ID: <20200806190211.118721-1-uzonyi.akos@gmail.com>

From: Uzonyi ?kos <uzonyi.akos at gmail.com>

NS ID type is unsigned int now. -1U is no longer used as an error indicator,
it just simply left 0 if initialization fails (but is's unlikely to happen).

I added a new function for creating tries, with a documentation explaining
the choice of using 4 for node_key_bits and data_block_key_bits.

Changes in v6:
  - Add function with documentation for creating tries
  - Do not use -1ULL as error indicator in tcb.pid_ns
  - Use unsigned int (instead of uint64_t) for NS IDs
  - Add constant for NS ID size.
  - Modify get_proc_pid a bit
  - Die if trie creation fails
Changes in v5:
  - Squash "Use printpid in *" commits
  - Makefile.am: move adding getpid.c to "Use printpid in decoders"
  - Remove pid_ns_inited field from struct tcb
  - strace.1.in: remove -Y flag
  - Use tprints instead of tprintf where possible
  - Make some global variables static
  - pidns_init: remove "inited" bool variable
  - Make printpid_translation static
  - tests/pidns.c: refactor a bit
  - check_ns_ioctl: fix error msg
  - defs.h: Move adding get_proc_pid to "PID namespace translation support"
  - Remove tcp paramter name from declarations
  - Update printfd_pid_tracee_ns documentation
  - Use named constants for trie_create arguments
  - Add documentation comments
  - Add printpid_tgid_pgid function
  - Delete get_pid_max function; use global variables instead
  - Refactor trie:
    - Move key_size argument
    - Remove support for TRIE_SET
    - Merge trie_create, trie_init, trie_check functions
    - trie_free_node: make static, fix "node" argument type
    - Add max_depth field
    - Reorder functions
    - Extract common parts of trie_get, trie_set
Changes in v4:
  - Skip tests if NS_* ioctl commands are not supported
  - Improve documentation in pidns.h
  - Use pipe for init process termination (instead of SIGKILL)
  - Add PIDNS_TEST_INIT macro
  - Remove "ifdef __NR_gettid"
  - Fix fork--pidns-tranlsation.test: skip if unshare fails with EPERM
  - Use debug message instead of normal message in some cases
  - Rename some labels
  - Rewrite get_ns function
  - Remove O_NONBLOCK from open(/proc/<pid>/ns/pid)
Changes in v3:
  - Split accidentally sqashed last commit
  - Undo modification of tests/pidfd_send_signal.c
  - Rename kcmp-yY test to kcmp-y--pidns-translation
  - Skip tests if unshare fails with EPERM
  - Fix buffer size in pidns_pid2str
  - Use largefile_wrappers.h macros
  - Return early if from_ns or our_ns is 0
  - Do not call ioctl(NS_GET_PARENT) again, if first failed with ENOTTY
  - Skip pidns tests if Linux kernel version < 4.9
  - Use smaller trie nodes in pidns.c
  - Remove race condition from fork--pidns-translation test
  - Move "key_size" to center in trie description
  - Use PT_TID (not PT_TGID) when translating tcp->pid
  - Fix get_ns_hierarchy and get_id_list functions
  - Fix migrate_pages test if syscall succeds
  - Fix filtering in ioctl_block--pidns-translation.test
  - Fix -a flag value in xetpriority test
Changes in v2:
  - Add missing header files to Makefile
  - Fix pointer-to-int-cast errors
  - Fix unused-result errors
  - Use perror_msg instead of perror_func_msg where appropriate
  - Remove tcb parameter of read_int_from_file
  - Use xsprintf instead of snprintf
  - Refactor get_pid_max, get_ns_hierarchy, get_id_list functions
  - Remove -Y flag
  - Improve documentation of trie
  - Fix printing of f_owner_ex struct
  - Use printpid for F_GETOWN, F_SETOWN fcntl command arguments
  - Use printpid for shmid_ds.shm_cpid, shmid_ds.shm_clid
  - Call pidns_init before parsing arguments

?kos Uzonyi (5):
  PID namespace translation support
  Use printpid in decoders
  Use get_proc_pid for /proc paths
  Implement testing framework for pidns
  Add tests for PID namespace translation

 Makefile.am                                   |   4 +
 NEWS                                          |   1 +
 affinity.c                                    |   6 +-
 block.c                                       |   2 +-
 bpf.c                                         |   2 +-
 capability.c                                  |   4 +-
 clone.c                                       |  14 +-
 defs.h                                        |  58 +-
 fcntl.c                                       |  24 +-
 get_robust_list.c                             |   3 +-
 getpid.c                                      |  46 ++
 ioprio.c                                      |  26 +-
 ipc_shmctl.c                                  |   5 +-
 kcmp.c                                        |   5 +-
 largefile_wrappers.h                          |   2 +
 linux/dummy.h                                 |   8 +-
 mmap_cache.c                                  |   2 +-
 msghdr.c                                      |   2 +-
 net.c                                         |   2 +-
 netlink.c                                     |   5 +-
 numa.c                                        |   6 +-
 pathtrace.c                                   |   5 +-
 pidfd_open.c                                  |   2 +-
 pidns.c                                       | 613 ++++++++++++++++++
 print_fields.h                                |  24 +
 printsiginfo.c                                |   2 +-
 process.c                                     |   3 +-
 process_vm.c                                  |   6 +-
 resource.c                                    |  27 +-
 sched.c                                       |  25 +-
 signal.c                                      |  21 +-
 sockaddr.c                                    |   2 +-
 strace.1.in                                   |   4 +
 strace.c                                      |  11 +-
 syscall.c                                     |  15 +
 tests/.gitignore                              |  31 +
 tests/Makefile.am                             |  37 ++
 tests/fcntl--pidns-translation.c              |   2 +
 tests/fcntl-common.c                          |  82 ++-
 tests/fcntl.c                                 |   1 +
 tests/fcntl64--pidns-translation.c            |   2 +
 tests/fcntl64.c                               |   3 +
 tests/fork--pidns-translation.awk             |  15 +
 tests/fork--pidns-translation.c               |  69 ++
 tests/fork--pidns-translation.test            |  16 +
 tests/gen_tests.in                            |  30 +-
 tests/getpgrp--pidns-translation.c            |   2 +
 tests/getpgrp.c                               |   8 +-
 tests/getpid--pidns-translation.c             |   2 +
 tests/getpid.c                                |   8 +-
 tests/getsid--pidns-translation.c             |   2 +
 tests/getsid.c                                |   9 +-
 tests/gettid--pidns-translation.c             |   2 +
 tests/gettid.c                                |   8 +-
 tests/init.sh                                 |  31 +
 tests/ioctl_block--pidns-translation.c        |   2 +
 tests/ioctl_block--pidns-translation.test     |  24 +
 tests/ioctl_block.c                           |  24 +-
 tests/ioprio--pidns-translation.c             |   2 +
 tests/ioprio.c                                |  54 +-
 tests/kcmp-y--pidns-translation.c             |   2 +
 tests/kcmp.c                                  |  36 +-
 tests/kill--pidns-translation.c               |   2 +
 tests/kill.c                                  |  12 +-
 tests/migrate_pages--pidns-translation.c      |   2 +
 tests/migrate_pages.c                         |  17 +-
 tests/move_pages--pidns-translation.c         |   2 +
 tests/move_pages.c                            |  51 +-
 tests/net-sockaddr--pidns-translation.c       |   2 +
 tests/net-sockaddr.c                          |  66 +-
 tests/netlink_audit--pidns-translation.c      |   2 +
 tests/netlink_audit--pidns-translation.test   |  13 +
 tests/netlink_audit.c                         |  11 +-
 tests/pidfd_open--pidns-translation.c         |   2 +
 tests/pidfd_open.c                            |  21 +-
 tests/pidfd_send_signal--pidns-translation.c  |   2 +
 tests/pidfd_send_signal.c                     |  13 +-
 tests/pidns.c                                 | 214 ++++++
 tests/pidns.h                                 |  56 ++
 tests/prlimit64--pidns-translation.c          |   2 +
 tests/prlimit64.c                             |  17 +-
 tests/process_vm_readv--pidns-translation.c   |   2 +
 tests/process_vm_readv_writev.c               |  27 +-
 tests/process_vm_writev--pidns-translation.c  |   2 +
 tests/rt_sigqueueinfo--pidns-translation.c    |   2 +
 tests/rt_sigqueueinfo.c                       |  15 +-
 tests/rt_tgsigqueueinfo--pidns-translation.c  |   2 +
 tests/rt_tgsigqueueinfo.c                     |  26 +-
 tests/sched_xetaffinity--pidns-translation.c  |   2 +
 tests/sched_xetaffinity.c                     |  31 +-
 tests/sched_xetattr--pidns-translation.c      |   2 +
 tests/sched_xetattr.c                         |  47 +-
 tests/sched_xetparam--pidns-translation.c     |   2 +
 tests/sched_xetparam.c                        |  20 +-
 tests/sched_xetscheduler--pidns-translation.c |   2 +
 tests/sched_xetscheduler.c                    |  44 +-
 tests/signal_receive--pidns-translation.c     |   2 +
 tests/signal_receive.c                        |  22 +-
 tests/so_peercred--pidns-translation.c        |   2 +
 tests/so_peercred.c                           |  22 +
 tests/xet_robust_list--pidns-translation.c    |   2 +
 tests/xet_robust_list.c                       |  18 +-
 tests/xetpgid--pidns-translation.c            |   2 +
 tests/xetpgid.c                               |  21 +-
 tests/xetpriority--pidns-translation.c        |   2 +
 tests/xetpriority.c                           |  20 +-
 trie.c                                        | 250 +++++++
 trie.h                                        |  89 +++
 util.c                                        |  27 +-
 wait.c                                        |  36 +-
 110 files changed, 2484 insertions(+), 255 deletions(-)
 create mode 100644 getpid.c
 create mode 100644 pidns.c
 create mode 100644 tests/fcntl--pidns-translation.c
 create mode 100644 tests/fcntl64--pidns-translation.c
 create mode 100644 tests/fork--pidns-translation.awk
 create mode 100644 tests/fork--pidns-translation.c
 create mode 100755 tests/fork--pidns-translation.test
 create mode 100644 tests/getpgrp--pidns-translation.c
 create mode 100644 tests/getpid--pidns-translation.c
 create mode 100644 tests/getsid--pidns-translation.c
 create mode 100644 tests/gettid--pidns-translation.c
 create mode 100644 tests/ioctl_block--pidns-translation.c
 create mode 100755 tests/ioctl_block--pidns-translation.test
 create mode 100644 tests/ioprio--pidns-translation.c
 create mode 100644 tests/kcmp-y--pidns-translation.c
 create mode 100644 tests/kill--pidns-translation.c
 create mode 100644 tests/migrate_pages--pidns-translation.c
 create mode 100644 tests/move_pages--pidns-translation.c
 create mode 100644 tests/net-sockaddr--pidns-translation.c
 create mode 100644 tests/netlink_audit--pidns-translation.c
 create mode 100755 tests/netlink_audit--pidns-translation.test
 create mode 100644 tests/pidfd_open--pidns-translation.c
 create mode 100644 tests/pidfd_send_signal--pidns-translation.c
 create mode 100644 tests/pidns.c
 create mode 100644 tests/pidns.h
 create mode 100644 tests/prlimit64--pidns-translation.c
 create mode 100644 tests/process_vm_readv--pidns-translation.c
 create mode 100644 tests/process_vm_writev--pidns-translation.c
 create mode 100644 tests/rt_sigqueueinfo--pidns-translation.c
 create mode 100644 tests/rt_tgsigqueueinfo--pidns-translation.c
 create mode 100644 tests/sched_xetaffinity--pidns-translation.c
 create mode 100644 tests/sched_xetattr--pidns-translation.c
 create mode 100644 tests/sched_xetparam--pidns-translation.c
 create mode 100644 tests/sched_xetscheduler--pidns-translation.c
 create mode 100644 tests/signal_receive--pidns-translation.c
 create mode 100644 tests/so_peercred--pidns-translation.c
 create mode 100644 tests/xet_robust_list--pidns-translation.c
 create mode 100644 tests/xetpgid--pidns-translation.c
 create mode 100644 tests/xetpriority--pidns-translation.c
 create mode 100644 trie.c
 create mode 100644 trie.h

--
2.27.0


From uzonyi.akos at gmail.com  Thu Aug  6 19:02:10 2020
From: uzonyi.akos at gmail.com (=?UTF-8?q?=C3=81kos=20Uzonyi?=)
Date: Thu,  6 Aug 2020 21:02:10 +0200
Subject: [PATCH v6 4/5] Implement testing framework for pidns
In-Reply-To: <20200806190211.118721-1-uzonyi.akos@gmail.com>
References: <20200806190211.118721-1-uzonyi.akos@gmail.com>
Message-ID: <20200806190211.118721-5-uzonyi.akos@gmail.com>

* tests/pidns.c: New file.
* tests/pidns.h: New file.
* tests/Makefile.am (libtests_a_SOURCES): Add pidns.c, pidns.h.
* tests/init.sh (test_pidns, test_pidns_run_strace): New functions.
---
 tests/Makefile.am |   2 +
 tests/init.sh     |  31 +++++++
 tests/pidns.c     | 214 ++++++++++++++++++++++++++++++++++++++++++++++
 tests/pidns.h     |  56 ++++++++++++
 4 files changed, 303 insertions(+)
 create mode 100644 tests/pidns.c
 create mode 100644 tests/pidns.h

diff --git a/tests/Makefile.am b/tests/Makefile.am
index 28d95e39..7a583a3a 100644
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@@ -44,6 +44,8 @@ libtests_a_SOURCES = \
 	libsocketcall.c \
 	lock_file.c \
 	overflowuid.c \
+	pidns.c \
+	pidns.h \
 	pipe_maxfd.c \
 	print_quoted_string.c \
 	print_time.c \
diff --git a/tests/init.sh b/tests/init.sh
index d78e697b..7325fa4a 100644
--- a/tests/init.sh
+++ b/tests/init.sh
@@ -387,6 +387,37 @@ test_prog_set()
 	test_pure_prog_set "$@" < "$srcdir/$NAME.in"
 }
 
+test_pidns_run_strace()
+{
+	local parent_pid
+
+	check_prog tail
+	check_prog cut
+	check_prog grep
+
+	run_prog > /dev/null
+	run_strace --pidns-translation -f $@ $args > "$EXP"
+
+	# filter out logs made by the parent or init process of the pidns test
+	parent_pid="$(tail -n 2 $LOG | head -n 1 | cut -d' ' -f1)"
+	init_pid="$(tail -n 1 $LOG | cut -d' ' -f1)"
+	grep -E -v "^($parent_pid|$init_pid) " "$LOG" > "$OUT"
+	match_diff "$OUT" "$EXP"
+}
+
+test_pidns()
+{
+	# ioctl(NS_GET_PARENT) is added in Linux 4.9
+	require_min_kernel_version_or_skip 4.9
+	check_prog unshare
+
+	test_pidns_run_strace "$@"
+
+	# test PID translation when /proc is mounted from an other namespace
+	STRACE="unshare -Urpf $STRACE"
+	test_pidns_run_strace "$@"
+}
+
 check_prog cat
 check_prog rm
 
diff --git a/tests/pidns.c b/tests/pidns.c
new file mode 100644
index 00000000..f54af340
--- /dev/null
+++ b/tests/pidns.c
@@ -0,0 +1,214 @@
+/*
+ * Testing framework for PID namespace translation
+ *
+ * Copyright (c) 2020 ?kos Uzonyi <uzonyi.akos at gmail.com>
+ * All rights reserved.
+ *
+ * SPDX-License-Identifier: LGPL-2.1-or-later
+ */
+#include "tests.h"
+#include "pidns.h"
+#include "nsfs.h"
+
+#include <errno.h>
+#include <stdio.h>
+#include <string.h>
+#include <sys/types.h>
+#include <signal.h>
+#include <stdlib.h>
+#include <sched.h>
+#include <unistd.h>
+#include <sys/wait.h>
+#include <linux/sched.h>
+#include <fcntl.h>
+#include <sys/ioctl.h>
+
+static bool pidns_translation = false;
+static bool pidns_unshared = false;
+
+/* Our PIDs in strace's namespace */
+static pid_t pidns_strace_ids[PT_COUNT];
+
+void
+pidns_print_leader(void)
+{
+	if (pidns_translation)
+		printf("%-5d ", pidns_strace_ids[PT_TID]);
+}
+
+const char *
+pidns_pid2str(enum pid_type type)
+{
+	static const char format[] = " /* %d in strace's PID NS */";
+	static char buf[PT_COUNT][sizeof(format) + sizeof(int) * 3];
+
+	if (type < 0 || type >= PT_COUNT)
+		return "";
+
+	if (!pidns_unshared || !pidns_strace_ids[type])
+		return "";
+
+	snprintf(buf[type], sizeof(buf[type]), format, pidns_strace_ids[type]);
+	return buf[type];
+}
+
+/**
+ * This function is like fork, but does a few more things. It sets up the
+ * child's PGID and SID according to the parameters. Also it fills the
+ * pidns_strace_ids array in the child's memory with the PIDs of the child in
+ * parent's PID namespace. In the parent it waits for the child to terminate
+ * (but leaves the zombie to use it later as a process group). If the child
+ * terminates with nonzero exit status, the test is failed.
+ *
+ * @param pgid     The process group the child should be moved to. It's expected
+ *                 to be a PID of a zombie process (will be reaped). If
+ *                 negative, leave the child in the process group of the parent.
+ *                 If 0, move the process to its own process group.
+ * @param new_sid  Wheather child should be moved to a new session.
+ */
+static pid_t
+pidns_fork(pid_t pgid, bool new_sid)
+{
+	int strace_ids_pipe[2];
+	if (pipe(strace_ids_pipe) < 0)
+		perror_msg_and_fail("pipe");
+
+	fflush(stdout);
+	pid_t pid = fork();
+	if (pid < 0)
+		perror_msg_and_fail("fork");
+
+	if (!pid) {
+		close(strace_ids_pipe[1]);
+		if (read(strace_ids_pipe[0], pidns_strace_ids,
+		    sizeof(pidns_strace_ids)) < 0)
+			perror_msg_and_fail("read");
+		close(strace_ids_pipe[0]);
+
+		if (pidns_strace_ids[PT_SID])
+			setsid();
+
+		return 0;
+	}
+
+	pidns_strace_ids[PT_TID] = pid;
+	pidns_strace_ids[PT_TGID] = pid;
+	pidns_strace_ids[PT_PGID] = 0;
+	pidns_strace_ids[PT_SID] = 0;
+
+	if (!pgid)
+		pgid = pid;
+
+	if (pgid > 0) {
+		if (setpgid(pid, pgid) < 0)
+			perror_msg_and_fail("setpgid");
+
+		pidns_strace_ids[PT_PGID] = pgid;
+	}
+
+	/* Reap group leader to test PGID decoding */
+	if (pgid > 0 && pgid != pid) {
+		int ret = waitpid(pgid, NULL, WNOHANG);
+		if (ret < 0)
+			perror_msg_and_fail("wait");
+		if (!ret)
+			error_msg_and_fail("could not reap group leader");
+	}
+
+	if (new_sid) {
+		pidns_strace_ids[PT_SID] = pid;
+		pidns_strace_ids[PT_PGID] = pid;
+	}
+
+	if (write(strace_ids_pipe[1], pidns_strace_ids,
+	    sizeof(pidns_strace_ids)) < 0)
+		perror_msg_and_fail("write");
+	close(strace_ids_pipe[0]);
+	close(strace_ids_pipe[1]);
+
+	/* WNOWAIT: leave the zombie, to be able to use it as a process group */
+	siginfo_t siginfo;
+	if (waitid(P_PID, pid, &siginfo, WEXITED | WNOWAIT) < 0)
+		perror_msg_and_fail("wait");
+	if (siginfo.si_code != CLD_EXITED || siginfo.si_status)
+		error_msg_and_fail("child terminated with nonzero exit status");
+
+	return pid;
+}
+
+static void
+create_init_process(void)
+{
+	int child_pipe[2];
+	if (pipe(child_pipe) < 0)
+		perror_msg_and_fail("pipe");
+
+	pid_t pid = fork();
+	if (pid < 0)
+		perror_msg_and_fail("fork");
+
+	if (!pid) {
+		close(child_pipe[1]);
+		_exit(read(child_pipe[0], &child_pipe[1], sizeof(int)) == 0);
+	}
+
+	close(child_pipe[0]);
+}
+
+void
+check_ns_ioctl(void)
+{
+	int fd = open("/proc/self/ns/pid", O_RDONLY);
+	if (fd < 0)
+		perror_msg_and_fail("opening /proc/self/ns/pid");
+
+	int userns_fd = ioctl(fd, NS_GET_USERNS);
+	if (userns_fd < 0) {
+		if (errno == ENOTTY)
+			error_msg_and_skip("NS_* ioctl commands are not "
+			                   "supported by the kernel");
+		else
+			perror_msg_and_fail("ioctl(NS_GET_USERNS)");
+	}
+
+	close(userns_fd);
+	close(fd);
+}
+
+void
+pidns_test_init(void)
+{
+	pidns_translation = true;
+
+	check_ns_ioctl();
+
+	if (!pidns_fork(-1, false))
+		return;
+
+	/* Unshare user namespace too, so we do not need to be root */
+	if (unshare(CLONE_NEWUSER | CLONE_NEWPID) < 0) {
+		if (errno == EPERM)
+			perror_msg_and_skip("unshare");
+
+		perror_msg_and_fail("unshare");
+	}
+
+	pidns_unshared = true;
+
+	create_init_process();
+
+	if (!pidns_fork(-1, false))
+		return;
+
+	if (!pidns_fork(-1, true))
+		return;
+
+	pid_t pgid;
+	if (!(pgid = pidns_fork(0, false)))
+		return;
+
+	if (!pidns_fork(pgid, false))
+		return;
+
+	exit(0);
+}
diff --git a/tests/pidns.h b/tests/pidns.h
new file mode 100644
index 00000000..76963eb3
--- /dev/null
+++ b/tests/pidns.h
@@ -0,0 +1,56 @@
+/*
+ * Test PID namespace translation
+ *
+ * Copyright (c) 2020 ?kos Uzonyi <uzonyi.akos at gmail.com>
+ * All rights reserved.
+ *
+ * SPDX-License-Identifier: LGPL-2.1-or-later
+ */
+#ifndef STRACE_PIDNS_H
+#define STRACE_PIDNS_H
+
+#ifdef PIDNS_TRANSLATION
+# define PIDNS_TEST_INIT pidns_test_init()
+#else
+# define PIDNS_TEST_INIT
+#endif
+
+#include <sys/types.h>
+
+enum pid_type {
+	PT_TID,
+	PT_TGID,
+	PT_PGID,
+	PT_SID,
+
+	PT_COUNT,
+	PT_NONE = -1
+};
+
+/* Prints leader (process tid) if pidns_test_init was called */
+void pidns_print_leader(void);
+
+/*
+ * Returns a static buffer containing the translation string of our PID.
+ */
+const char *pidns_pid2str(enum pid_type type);
+
+/**
+ * Skips the test if NS_* ioctl commands are not supported by the kernel.
+ */
+void check_ns_ioctl(void);
+
+/**
+ * Init pidns testing.
+ *
+ * Should be called at the beginning of the test's main function
+ *
+ * This function calls fork a couple of times, and returns in the child
+ * processes. These child processes are in a new PID namespace with different
+ * PID configurations (group leader, session leader, ...). If any child
+ * terminates with nonzero exit status the test is failed. Otherwise the test is
+ * succesful, and the parent process exits with 0.
+ */
+void pidns_test_init(void);
+
+#endif
\ No newline at end of file
-- 
2.27.0


From uzonyi.akos at gmail.com  Thu Aug  6 19:02:08 2020
From: uzonyi.akos at gmail.com (=?UTF-8?q?=C3=81kos=20Uzonyi?=)
Date: Thu,  6 Aug 2020 21:02:08 +0200
Subject: [PATCH v6 2/5] Use printpid in decoders
In-Reply-To: <20200806190211.118721-1-uzonyi.akos@gmail.com>
References: <20200806190211.118721-1-uzonyi.akos@gmail.com>
Message-ID: <20200806190211.118721-3-uzonyi.akos@gmail.com>

* getpid.c: New file.
* Makefile.am (libstrace_a_SOURCES): Add getpid.c.
* linux/dummy.h (sys_getpid, sys_getppid, sys_gettid,
sys_setpgid, sys_setpgrp): Remove.
* util.c (printfd_pid_tracee_ns): Implement using translate_pid.
* defs.h (printnum_pid): New function definition.
(printfd_pid_tracee_ns): Update documentation
* util.c: (printnum_pid): New function.
* print_fields.h (PRINT_FIELD_TID): New macro.
(PRINT_FIELD_TGID): Likewise.
(PRINT_FIELD_PGID): Likewise.
(PRINT_FIELD_SID): Likewise.
* affinity.c: Print PIDs with printpid.
* block.c: Likewise.
* bpf.c: Likewise.
* capability.c: Likewise.
* clone.c: Likewise.
* fcntl.c: Likewise.
* get_robust_list.c: Likewise.
* ioprio.c: Likewise.
* kcmp.c: Likewise.
* msghdr.c: Likewise.
* net.c: Likewise.
* netlink.c: Likewise.
* numa.c: Likewise.
* pidfd_open.c: Likewise.
* printsiginfo.c: Likewise.
* process.c: Likewise.
* process_vm.c: Likewise.
* resource.c: Likewise.
* sched.c: Likewise.
* signal.c: Likewise.
* sockaddr.c: Likewise.
* wait.c: Likewise.
* kcmp.c (SYS_FUNC(kcmp)): Fix KCMP_FILE pid arguments.
* tests/kcmp.c (printpidfd): Print path if VERBOSE_FD.
(main): Use our real pid if real fds are used.
---
 Makefile.am       |  1 +
 affinity.c        |  6 ++++--
 block.c           |  2 +-
 bpf.c             |  2 +-
 capability.c      |  4 +++-
 clone.c           | 14 +++++++-------
 defs.h            |  5 ++++-
 fcntl.c           | 24 ++++++++++++++++++++++--
 get_robust_list.c |  3 ++-
 getpid.c          | 46 ++++++++++++++++++++++++++++++++++++++++++++++
 ioprio.c          | 26 ++++++++++++++++++++++----
 ipc_shmctl.c      |  5 +++--
 kcmp.c            |  5 ++++-
 linux/dummy.h     |  8 +-------
 msghdr.c          |  2 +-
 net.c             |  2 +-
 netlink.c         |  5 +++--
 numa.c            |  6 ++++--
 pidfd_open.c      |  2 +-
 print_fields.h    | 24 ++++++++++++++++++++++++
 printsiginfo.c    |  2 +-
 process.c         |  3 ++-
 process_vm.c      |  6 ++++--
 resource.c        | 27 ++++++++++++++++++++++++---
 sched.c           | 25 ++++++++++++++++---------
 signal.c          | 21 +++++++++++++++------
 sockaddr.c        |  2 +-
 tests/kcmp.c      | 25 ++++++++++++++++++++++---
 util.c            | 20 ++++++++++++++------
 wait.c            | 36 ++++++++++++++++++++++++------------
 30 files changed, 278 insertions(+), 81 deletions(-)
 create mode 100644 getpid.c

diff --git a/Makefile.am b/Makefile.am
index 73c22035..15fcd9a6 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -135,6 +135,7 @@ libstrace_a_SOURCES =	\
 	getcpu.c	\
 	getcwd.c	\
 	getpagesize.c \
+	getpid.c	\
 	getrandom.c	\
 	hdio.c		\
 	hostname.c	\
diff --git a/affinity.c b/affinity.c
index eb3158b7..f9893adb 100644
--- a/affinity.c
+++ b/affinity.c
@@ -82,7 +82,8 @@ SYS_FUNC(sched_setaffinity)
 	const int pid = tcp->u_arg[0];
 	const unsigned int len = tcp->u_arg[1];
 
-	tprintf("%d, %u, ", pid, len);
+	printpid(tcp, pid, PT_TGID);
+	tprintf(", %u, ", len);
 	print_affinitylist(tcp, tcp->u_arg[2], len);
 
 	return RVAL_DECODED;
@@ -94,7 +95,8 @@ SYS_FUNC(sched_getaffinity)
 	const unsigned int len = tcp->u_arg[1];
 
 	if (entering(tcp)) {
-		tprintf("%d, %u, ", pid, len);
+		printpid(tcp, pid, PT_TGID);
+		tprintf(", %u, ", len);
 	} else {
 		print_affinitylist(tcp, tcp->u_arg[2], tcp->u_rval);
 	}
diff --git a/block.c b/block.c
index b527ef43..783a4b5a 100644
--- a/block.c
+++ b/block.c
@@ -179,7 +179,7 @@ MPERS_PRINTER_DECL(int, block_ioctl, struct tcb *const tcp,
 			PRINT_FIELD_U(", ", buts, buf_nr);
 			PRINT_FIELD_U(", ", buts, start_lba);
 			PRINT_FIELD_U(", ", buts, end_lba);
-			PRINT_FIELD_D(", ", buts, pid);
+			PRINT_FIELD_TGID(", ", buts, pid, tcp);
 			return 0;
 		} else {
 			struct_blk_user_trace_setup buts;
diff --git a/bpf.c b/bpf.c
index af830053..0ec33ba4 100644
--- a/bpf.c
+++ b/bpf.c
@@ -927,7 +927,7 @@ BEGIN_BPF_CMD_DECODER(BPF_TASK_FD_QUERY)
 	if (entering(tcp)) {
 		set_tcb_priv_ulong(tcp, attr.buf_len);
 
-		PRINT_FIELD_D("{task_fd_query={", attr, pid);
+		PRINT_FIELD_TGID("{task_fd_query={", attr, pid, tcp);
 		PRINT_FIELD_FD(", ", attr, fd, tcp);
 		PRINT_FIELD_U(", ", attr, flags);
 		PRINT_FIELD_U(", ", attr, buf_len);
diff --git a/capability.c b/capability.c
index 0e763ee1..812fb435 100644
--- a/capability.c
+++ b/capability.c
@@ -70,7 +70,9 @@ print_cap_header(struct tcb *const tcp, const kernel_ulong_t addr,
 	tprints("{version=");
 	printxval(cap_version, h->version,
 		  "_LINUX_CAPABILITY_VERSION_???");
-	tprintf(", pid=%d}", h->pid);
+	tprints(", pid=");
+	printpid(tcp, h->pid, PT_TGID);
+	tprints("}");
 }
 
 static void
diff --git a/clone.c b/clone.c
index 487c5c23..45f24065 100644
--- a/clone.c
+++ b/clone.c
@@ -114,14 +114,14 @@ SYS_FUNC(clone)
 		 */
 		if ((flags & (CLONE_PARENT_SETTID|CLONE_PIDFD|CLONE_CHILD_SETTID
 			      |CLONE_CHILD_CLEARTID|CLONE_SETTLS)) == 0)
-			return RVAL_DECODED;
+			return RVAL_DECODED | RVAL_TID;
 	} else {
 		if (flags & (CLONE_PARENT_SETTID|CLONE_PIDFD)) {
 			kernel_ulong_t addr = tcp->u_arg[ARG_PTID];
 
 			tprints(", parent_tid=");
 			if (flags & CLONE_PARENT_SETTID)
-				printnum_int(tcp, addr, "%u");
+				printnum_pid(tcp, addr, PT_TID);
 			else
 				printnum_fd(tcp, addr);
 		}
@@ -134,7 +134,7 @@ SYS_FUNC(clone)
 			printaddr(tcp->u_arg[ARG_CTID]);
 		}
 	}
-	return 0;
+	return RVAL_TID;
 }
 
 
@@ -229,7 +229,7 @@ SYS_FUNC(clone3)
 
 		if ((arg.flags & (CLONE_PIDFD | CLONE_PARENT_SETTID)) ||
 		    (size > fetch_size))
-			return 0;
+			return RVAL_TID;
 
 		goto out;
 	}
@@ -256,7 +256,7 @@ SYS_FUNC(clone3)
 
 	if (arg.flags & CLONE_PARENT_SETTID) {
 		tprintf("%sparent_tid=", pfx);
-		printnum_int(tcp, arg.parent_tid, "%d"); /* TID */
+		printnum_pid(tcp, arg.parent_tid, PT_TID);
 		pfx = ", ";
 	}
 
@@ -279,7 +279,7 @@ SYS_FUNC(clone3)
 out:
 	tprintf(", %" PRI_klu, size);
 
-	return RVAL_DECODED;
+	return RVAL_DECODED | RVAL_TID;
 }
 
 
@@ -300,5 +300,5 @@ SYS_FUNC(unshare)
 
 SYS_FUNC(fork)
 {
-	return RVAL_DECODED;
+	return RVAL_DECODED | RVAL_TGID;
 }
diff --git a/defs.h b/defs.h
index 692fa0d3..f59da4ba 100644
--- a/defs.h
+++ b/defs.h
@@ -1098,7 +1098,7 @@ printfd(struct tcb *tcp, int fd)
 
 /**
  * Print file descriptor fd owned by process with ID pid (from the PID NS
- * of the tracee the descriptor tcp).  This is a stub.
+ * of the tracee).
  */
 extern void printfd_pid_tracee_ns(struct tcb *tcp, pid_t pid, int fd);
 
@@ -1558,6 +1558,9 @@ DECL_PRINTNUM_ADDR(int64);
 extern bool
 printnum_fd(struct tcb *, kernel_ulong_t addr);
 
+extern bool
+printnum_pid(struct tcb *const tcp, const kernel_ulong_t addr, enum pid_type type);
+
 static inline bool
 printnum_slong(struct tcb *tcp, kernel_ulong_t addr)
 {
diff --git a/fcntl.c b/fcntl.c
index 6fcd5dac..5c630a06 100644
--- a/fcntl.c
+++ b/fcntl.c
@@ -28,7 +28,7 @@ print_struct_flock64(struct tcb *const tcp, const struct_kernel_flock64 *fl, con
 	PRINT_FIELD_D(", ", *fl, l_start);
 	PRINT_FIELD_D(", ", *fl, l_len);
 	if (getlk)
-		PRINT_FIELD_D(", ", *fl, l_pid);
+		PRINT_FIELD_TGID(", ", *fl, l_pid, tcp);
 	tprints("}");
 }
 
@@ -59,7 +59,22 @@ print_f_owner_ex(struct tcb *const tcp, const kernel_ulong_t addr)
 		return;
 
 	PRINT_FIELD_XVAL("{", owner, type, f_owner_types, "F_OWNER_???");
-	PRINT_FIELD_D(", ", owner, pid);
+
+	enum pid_type pid_type = PT_NONE;
+	switch (owner.type)
+	{
+	case F_OWNER_TID:
+		pid_type = PT_TID;
+		break;
+	case F_OWNER_PID:
+		pid_type = PT_TGID;
+		break;
+	case F_OWNER_PGRP:
+		pid_type = PT_PGID;
+		break;
+	}
+	tprints(", pid=");
+	printpid(tcp, owner.pid, pid_type);
 	tprints("}");
 }
 
@@ -74,6 +89,9 @@ print_fcntl(struct tcb *tcp)
 		printflags(fdflags, tcp->u_arg[2], "FD_???");
 		break;
 	case F_SETOWN:
+		tprints(", ");
+		printpid_tgid_pgid(tcp, tcp->u_arg[2]);
+		break;
 	case F_SETPIPE_SZ:
 		tprintf(", %" PRI_kld, tcp->u_arg[2]);
 		break;
@@ -116,6 +134,8 @@ print_fcntl(struct tcb *tcp)
 		printsignal(tcp->u_arg[2]);
 		break;
 	case F_GETOWN:
+		return RVAL_DECODED |
+		       ((int) tcp->u_rval < 0 ? RVAL_PGID : RVAL_TGID);
 	case F_GETPIPE_SZ:
 		break;
 	case F_GETFD:
diff --git a/get_robust_list.c b/get_robust_list.c
index b5aebaff..4b771bac 100644
--- a/get_robust_list.c
+++ b/get_robust_list.c
@@ -10,7 +10,8 @@
 SYS_FUNC(get_robust_list)
 {
 	if (entering(tcp)) {
-		tprintf("%d, ", (int) tcp->u_arg[0]);
+		printpid(tcp, (int) tcp->u_arg[0], PT_TID);
+		tprints(", ");
 	} else {
 		printnum_ptr(tcp, tcp->u_arg[1]);
 		tprints(", ");
diff --git a/getpid.c b/getpid.c
new file mode 100644
index 00000000..5e9a1a29
--- /dev/null
+++ b/getpid.c
@@ -0,0 +1,46 @@
+/*
+ * Copyright (c) 2020 ?kos Uzonyi <uzonyi.akos at gmail.com>
+ * All rights reserved.
+ *
+ * SPDX-License-Identifier: LGPL-2.1-or-later
+ */
+
+#include "defs.h"
+
+SYS_FUNC(getpid)
+{
+	return RVAL_DECODED | RVAL_TGID;
+}
+
+SYS_FUNC(gettid)
+{
+	return RVAL_DECODED | RVAL_TID;
+}
+
+SYS_FUNC(getpgrp)
+{
+	return RVAL_DECODED | RVAL_PGID;
+}
+
+SYS_FUNC(getpgid)
+{
+	printpid(tcp, tcp->u_arg[0], PT_TGID);
+
+	return RVAL_DECODED | RVAL_PGID;
+}
+
+SYS_FUNC(getsid)
+{
+	printpid(tcp, tcp->u_arg[0], PT_TGID);
+
+	return RVAL_DECODED | RVAL_SID;
+}
+
+SYS_FUNC(setpgid)
+{
+	printpid(tcp, tcp->u_arg[0], PT_TGID);
+	tprints(", ");
+	printpid(tcp, tcp->u_arg[1], PT_PGID);
+
+	return RVAL_DECODED;
+}
diff --git a/ioprio.c b/ioprio.c
index 873c8ce5..52144884 100644
--- a/ioprio.c
+++ b/ioprio.c
@@ -49,13 +49,30 @@ print_ioprio(unsigned int ioprio)
 		? tprints_comment : tprints)(str);
 }
 
+static void
+ioprio_print_who(struct tcb *tcp, int which, int who)
+{
+	switch (which)
+	{
+	case IOPRIO_WHO_PROCESS:
+		printpid(tcp, who, PT_TGID);
+		break;
+	case IOPRIO_WHO_PGRP:
+		printpid(tcp, who, PT_PGID);
+		break;
+	default:
+		tprintf("%d", who);
+		break;
+	}
+}
+
 SYS_FUNC(ioprio_get)
 {
 	if (entering(tcp)) {
 		/* int which */
 		printxval(ioprio_who, tcp->u_arg[0], "IOPRIO_WHO_???");
-		/* int who */
-		tprintf(", %d", (int) tcp->u_arg[1]);
+		tprints(", ");
+		ioprio_print_who(tcp, (int) tcp->u_arg[0], (int) tcp->u_arg[1]);
 		return 0;
 	} else {
 		if (syserror(tcp))
@@ -72,8 +89,9 @@ SYS_FUNC(ioprio_set)
 {
 	/* int which */
 	printxval(ioprio_who, tcp->u_arg[0], "IOPRIO_WHO_???");
-	/* int who */
-	tprintf(", %d, ", (int) tcp->u_arg[1]);
+	tprints(", ");
+	ioprio_print_who(tcp, (int) tcp->u_arg[0], (int) tcp->u_arg[1]);
+	tprints(", ");
 	/* int ioprio */
 	if (xlat_verbose(xlat_verbosity) != XLAT_STYLE_ABBREV)
 		tprintf("%d", (int) tcp->u_arg[2]);
diff --git a/ipc_shmctl.c b/ipc_shmctl.c
index 8c9e1e7a..71b41651 100644
--- a/ipc_shmctl.c
+++ b/ipc_shmctl.c
@@ -12,6 +12,7 @@
  */
 
 #include "defs.h"
+#include "print_fields.h"
 
 #include DEF_MPERS_TYPE(shmid_ds_t)
 
@@ -53,8 +54,8 @@ print_shmid_ds(struct tcb *const tcp, const kernel_ulong_t addr, int cmd)
 		PRINT_FIELD_UID(", ", shmid_ds.shm_perm, cgid);
 		tprints("}");
 		tprintf(", shm_segsz=%u", (unsigned) shmid_ds.shm_segsz);
-		PRINT_FIELD_D(", ", shmid_ds, shm_cpid);
-		PRINT_FIELD_D(", ", shmid_ds, shm_lpid);
+		PRINT_FIELD_TGID(", ", shmid_ds, shm_cpid, tcp);
+		PRINT_FIELD_TGID(", ", shmid_ds, shm_lpid, tcp);
 		tprintf(", shm_nattch=%u", (unsigned) shmid_ds.shm_nattch);
 		tprintf(", shm_atime=%u", (unsigned) shmid_ds.shm_atime);
 		tprintf(", shm_dtime=%u", (unsigned) shmid_ds.shm_dtime);
diff --git a/kcmp.c b/kcmp.c
index 62115555..a5e1cdce 100644
--- a/kcmp.c
+++ b/kcmp.c
@@ -30,7 +30,10 @@ SYS_FUNC(kcmp)
 	kernel_ulong_t idx1 = tcp->u_arg[3];
 	kernel_ulong_t idx2 = tcp->u_arg[4];
 
-	tprintf("%d, %d, ", pid1, pid2);
+	printpid(tcp, pid1, PT_TGID);
+	tprints(", ");
+	printpid(tcp, pid2, PT_TGID);
+	tprints(", ");
 	printxval(kcmp_types, type, "KCMP_???");
 
 	switch (type) {
diff --git a/linux/dummy.h b/linux/dummy.h
index 2f859a60..ca0d2f0c 100644
--- a/linux/dummy.h
+++ b/linux/dummy.h
@@ -53,6 +53,7 @@
 # define sys_getgid		sys_getuid
 # define sys_getgid16		sys_getuid16
 # define sys_getpeername		sys_getsockname
+# define sys_getppid		sys_getpid
 # define sys_getresgid		sys_getresuid
 # define sys_getresgid16		sys_getresuid16
 # define sys_lstat		sys_stat
@@ -87,10 +88,6 @@
 # define sys_vfork		sys_fork
 
 /* printargs does the right thing */
-# define sys_getpgrp		printargs
-# define sys_getpid		printargs
-# define sys_getppid		printargs
-# define sys_gettid		printargs
 # define sys_idle		printargs
 # define sys_munlockall		printargs
 # define sys_pause		printargs
@@ -108,10 +105,7 @@
 
 /* printargs_d does the right thing */
 # define sys_exit		printargs_d
-# define sys_getpgid		printargs_d
-# define sys_getsid		printargs_d
 # define sys_nice		printargs_d
-# define sys_setpgid		printargs_d
 # define sys_setpgrp		printargs_d
 # define sys_timer_delete	printargs_d
 # define sys_timer_getoverrun	printargs_d
diff --git a/msghdr.c b/msghdr.c
index ef6dc24b..170b8e51 100644
--- a/msghdr.c
+++ b/msghdr.c
@@ -69,7 +69,7 @@ print_scm_creds(struct tcb *tcp, const void *cmsg_data,
 {
 	const struct ucred *uc = cmsg_data;
 
-	PRINT_FIELD_D("{", *uc, pid);
+	PRINT_FIELD_TGID("{", *uc, pid, tcp);
 	PRINT_FIELD_UID(", ", *uc, uid);
 	PRINT_FIELD_UID(", ", *uc, gid);
 	tprints("}");
diff --git a/net.c b/net.c
index fa4638e7..2099f0ac 100644
--- a/net.c
+++ b/net.c
@@ -601,7 +601,7 @@ print_get_ucred(struct tcb *const tcp, const kernel_ulong_t addr,
 	if (umoven_or_printaddr(tcp, addr, len, &uc))
 		return;
 
-	PRINT_FIELD_LEN("{", uc, pid, len, PRINT_FIELD_D);
+	PRINT_FIELD_LEN("{", uc, pid, len, PRINT_FIELD_TGID, tcp);
 	PRINT_FIELD_LEN(", ", uc, uid, len, PRINT_FIELD_UID);
 	PRINT_FIELD_LEN(", ", uc, gid, len, PRINT_FIELD_UID);
 	tprints("}");
diff --git a/netlink.c b/netlink.c
index 88d864a9..cb29033a 100644
--- a/netlink.c
+++ b/netlink.c
@@ -446,8 +446,9 @@ print_nlmsghdr(struct tcb *tcp,
 	decode_nlmsg_flags(nlmsghdr->nlmsg_flags,
 			   nlmsghdr->nlmsg_type, family);
 
-	tprintf(", seq=%u, pid=%d}", nlmsghdr->nlmsg_seq,
-		nlmsghdr->nlmsg_pid);
+	tprintf(", seq=%u, pid=", nlmsghdr->nlmsg_seq);
+	printpid(tcp, nlmsghdr->nlmsg_pid, PT_TGID);
+	tprints("}");
 }
 
 static bool
diff --git a/numa.c b/numa.c
index cc7a7cc6..37b95397 100644
--- a/numa.c
+++ b/numa.c
@@ -44,7 +44,8 @@ print_nodemask(struct tcb *const tcp, const kernel_ulong_t addr,
 
 SYS_FUNC(migrate_pages)
 {
-	tprintf("%d, %" PRI_klu ", ", (int) tcp->u_arg[0], tcp->u_arg[1]);
+	printpid(tcp, (int) tcp->u_arg[0], PT_TGID);
+	tprintf(", %" PRI_klu ", ", tcp->u_arg[1]);
 	print_nodemask(tcp, tcp->u_arg[2], tcp->u_arg[1]);
 	tprints(", ");
 	print_nodemask(tcp, tcp->u_arg[3], tcp->u_arg[1]);
@@ -170,7 +171,8 @@ SYS_FUNC(move_pages)
 	kernel_ulong_t buf;
 
 	if (entering(tcp)) {
-		tprintf("%d, %" PRI_klu ", ", (int) tcp->u_arg[0], npages);
+		printpid(tcp, (int) tcp->u_arg[0], PT_TGID);
+		tprintf(", %" PRI_klu ", ", npages);
 		print_array(tcp, tcp->u_arg[2], npages, &buf, current_wordsize,
 			    tfetch_mem, print_addr, 0);
 		tprints(", ");
diff --git a/pidfd_open.c b/pidfd_open.c
index bbc7f617..10b5003d 100644
--- a/pidfd_open.c
+++ b/pidfd_open.c
@@ -10,7 +10,7 @@
 SYS_FUNC(pidfd_open)
 {
 	/* pid_t pid */
-	tprintf("%d", (int) tcp->u_arg[0]);
+	printpid(tcp, (int) tcp->u_arg[0], PT_TGID);
 
 	/* unsigned int flags */
 	tprintf(", %#x", (unsigned int) tcp->u_arg[1]);
diff --git a/print_fields.h b/print_fields.h
index f9714115..33d4a458 100644
--- a/print_fields.h
+++ b/print_fields.h
@@ -263,6 +263,30 @@
 		printfd((tcp_), (where_).field_);			\
 	} while (0)
 
+# define PRINT_FIELD_TID(prefix_, where_, field_, tcp_)			\
+	do {								\
+		STRACE_PRINTF("%s%s=", (prefix_), #field_);		\
+		printpid((tcp_), (where_).field_, PT_TID);			\
+	} while (0)
+
+# define PRINT_FIELD_TGID(prefix_, where_, field_, tcp_)			\
+	do {								\
+		STRACE_PRINTF("%s%s=", (prefix_), #field_);		\
+		printpid((tcp_), (where_).field_, PT_TGID);			\
+	} while (0)
+
+# define PRINT_FIELD_PGID(prefix_, where_, field_, tcp_)			\
+	do {								\
+		STRACE_PRINTF("%s%s=", (prefix_), #field_);		\
+		printpid((tcp_), (where_).field_, PT_PGID);			\
+	} while (0)
+
+# define PRINT_FIELD_SID(prefix_, where_, field_, tcp_)			\
+	do {								\
+		STRACE_PRINTF("%s%s=", (prefix_), #field_);		\
+		printpid((tcp_), (where_).field_, PT_SID);			\
+	} while (0)
+
 # define PRINT_FIELD_STRN(prefix_, where_, field_, len_, tcp_)		\
 	do {								\
 		STRACE_PRINTF("%s%s=", (prefix_), #field_);		\
diff --git a/printsiginfo.c b/printsiginfo.c
index 8ed1e7ba..cb4cde4a 100644
--- a/printsiginfo.c
+++ b/printsiginfo.c
@@ -58,7 +58,7 @@
 static void
 printsigsource(struct tcb *tcp, const siginfo_t *sip)
 {
-	PRINT_FIELD_D(", ", *sip, si_pid);
+	PRINT_FIELD_TGID(", ", *sip, si_pid, tcp);
 	PRINT_FIELD_UID(", ", *sip, si_uid);
 }
 
diff --git a/process.c b/process.c
index a98c304e..d6ff255d 100644
--- a/process.c
+++ b/process.c
@@ -92,7 +92,8 @@ SYS_FUNC(ptrace)
 		}
 
 		/* pid */
-		tprintf(", %d", pid);
+		tprints(", ");
+		printpid(tcp, pid, PT_TGID);
 
 		/* addr */
 		switch (request) {
diff --git a/process_vm.c b/process_vm.c
index abee1e68..50acb3fd 100644
--- a/process_vm.c
+++ b/process_vm.c
@@ -13,7 +13,8 @@ SYS_FUNC(process_vm_readv)
 {
 	if (entering(tcp)) {
 		/* arg 1: pid */
-		tprintf("%d, ", (int) tcp->u_arg[0]);
+		printpid(tcp, (int) tcp->u_arg[0], PT_TGID);
+		tprints(", ");
 	} else {
 		kernel_ulong_t local_iovcnt = tcp->u_arg[2];
 		kernel_ulong_t remote_iovcnt = tcp->u_arg[4];
@@ -42,7 +43,8 @@ SYS_FUNC(process_vm_writev)
 	kernel_ulong_t flags = tcp->u_arg[5];
 
 	/* arg 1: pid */
-	tprintf("%d, ", (int) tcp->u_arg[0]);
+	printpid(tcp, (int) tcp->u_arg[0], PT_TGID);
+	tprints(", ");
 	/* arg 2: local iov */
 	tprint_iov(tcp, local_iovcnt, tcp->u_arg[1], IOV_DECODE_STR);
 	/* arg 3: local iovcnt */
diff --git a/resource.c b/resource.c
index 53192ee9..bd21b748 100644
--- a/resource.c
+++ b/resource.c
@@ -142,7 +142,8 @@ SYS_FUNC(setrlimit)
 SYS_FUNC(prlimit64)
 {
 	if (entering(tcp)) {
-		tprintf("%d, ", (int) tcp->u_arg[0]);
+		printpid(tcp, (int) tcp->u_arg[0], PT_TGID);
+		tprints(", ");
 		printxval(resources, tcp->u_arg[1], "RLIMIT_???");
 		tprints(", ");
 		print_rlimit64(tcp, tcp->u_arg[2]);
@@ -179,10 +180,28 @@ SYS_FUNC(osf_getrusage)
 
 #include "xlat/priorities.h"
 
+static void
+priority_print_who(struct tcb *tcp, int which, int who)
+{
+	switch (which)
+	{
+	case PRIO_PROCESS:
+		printpid(tcp, who, PT_TGID);
+		break;
+	case PRIO_PGRP:
+		printpid(tcp, who, PT_PGID);
+		break;
+	default:
+		tprintf("%d", who);
+		break;
+	}
+}
+
 SYS_FUNC(getpriority)
 {
 	printxval(priorities, tcp->u_arg[0], "PRIO_???");
-	tprintf(", %d", (int) tcp->u_arg[1]);
+	tprints(", ");
+	priority_print_who(tcp, tcp->u_arg[0], tcp->u_arg[1]);
 
 	return RVAL_DECODED;
 }
@@ -190,7 +209,9 @@ SYS_FUNC(getpriority)
 SYS_FUNC(setpriority)
 {
 	printxval(priorities, tcp->u_arg[0], "PRIO_???");
-	tprintf(", %d, %d", (int) tcp->u_arg[1], (int) tcp->u_arg[2]);
+	tprints(", ");
+	priority_print_who(tcp, tcp->u_arg[0], tcp->u_arg[1]);
+	tprintf(", %d", (int) tcp->u_arg[2]);
 
 	return RVAL_DECODED;
 }
diff --git a/sched.c b/sched.c
index 788ef39b..7ae5abe2 100644
--- a/sched.c
+++ b/sched.c
@@ -21,7 +21,7 @@
 SYS_FUNC(sched_getscheduler)
 {
 	if (entering(tcp)) {
-		tprintf("%d", (int) tcp->u_arg[0]);
+		printpid(tcp, (int) tcp->u_arg[0], PT_TGID);
 	} else if (!syserror(tcp)) {
 		tcp->auxstr = xlookup(schedulers, (kernel_ulong_t) tcp->u_rval);
 		return RVAL_STR;
@@ -31,7 +31,8 @@ SYS_FUNC(sched_getscheduler)
 
 SYS_FUNC(sched_setscheduler)
 {
-	tprintf("%d, ", (int) tcp->u_arg[0]);
+	printpid(tcp, (int) tcp->u_arg[0], PT_TGID);
+	tprints(", ");
 	printxval(schedulers, tcp->u_arg[1], "SCHED_???");
 	tprints(", ");
 	printnum_int(tcp, tcp->u_arg[2], "%d");
@@ -41,16 +42,19 @@ SYS_FUNC(sched_setscheduler)
 
 SYS_FUNC(sched_getparam)
 {
-	if (entering(tcp))
-		tprintf("%d, ", (int) tcp->u_arg[0]);
-	else
+	if (entering(tcp)) {
+		printpid(tcp, (int) tcp->u_arg[0], PT_TGID);
+		tprints(", ");
+	} else {
 		printnum_int(tcp, tcp->u_arg[1], "%d");
+	}
 	return 0;
 }
 
 SYS_FUNC(sched_setparam)
 {
-	tprintf("%d, ", (int) tcp->u_arg[0]);
+	printpid(tcp, (int) tcp->u_arg[0], PT_TGID);
+	tprints(", ");
 	printnum_int(tcp, tcp->u_arg[1], "%d");
 
 	return RVAL_DECODED;
@@ -68,7 +72,8 @@ do_sched_rr_get_interval(struct tcb *const tcp,
 			 const print_obj_by_addr_fn print_ts)
 {
 	if (entering(tcp)) {
-		tprintf("%d, ", (int) tcp->u_arg[0]);
+		printpid(tcp, (int) tcp->u_arg[0], PT_TGID);
+		tprints(", ");
 	} else {
 		if (syserror(tcp))
 			printaddr(tcp->u_arg[1]);
@@ -160,7 +165,8 @@ end:
 SYS_FUNC(sched_setattr)
 {
 	if (entering(tcp)) {
-		tprintf("%d, ", (int) tcp->u_arg[0]);
+		printpid(tcp, (int) tcp->u_arg[0], PT_TGID);
+		tprints(", ");
 		print_sched_attr(tcp, tcp->u_arg[1], 0);
 	} else {
 		struct sched_attr attr;
@@ -179,7 +185,8 @@ SYS_FUNC(sched_setattr)
 SYS_FUNC(sched_getattr)
 {
 	if (entering(tcp)) {
-		tprintf("%d, ", (int) tcp->u_arg[0]);
+		printpid(tcp, (int) tcp->u_arg[0], PT_TGID);
+		tprints(", ");
 	} else {
 		const unsigned int size = tcp->u_arg[2];
 
diff --git a/signal.c b/signal.c
index d5d59105..510b8992 100644
--- a/signal.c
+++ b/signal.c
@@ -439,7 +439,8 @@ SYS_FUNC(sigprocmask)
 SYS_FUNC(kill)
 {
 	/* pid */
-	tprintf("%d, ", (int) tcp->u_arg[0]);
+	printpid_tgid_pgid(tcp, tcp->u_arg[0]);
+	tprints(", ");
 	/* signal */
 	printsignal(tcp->u_arg[1]);
 
@@ -448,7 +449,7 @@ SYS_FUNC(kill)
 
 SYS_FUNC(tkill)
 {
-	tprintf("%d", (int) tcp->u_arg[0]);
+	printpid(tcp, (int) tcp->u_arg[0], PT_TID);
 	tprints(", ");
 	printsignal(tcp->u_arg[1]);
 
@@ -457,8 +458,12 @@ SYS_FUNC(tkill)
 
 SYS_FUNC(tgkill)
 {
-	/* tgid, tid */
-	tprintf("%d, %d, ", (int) tcp->u_arg[0], (int) tcp->u_arg[1]);
+	/* tgid */
+	printpid(tcp, (int) tcp->u_arg[0], PT_TGID);
+	tprints(", ");
+	/* tid */
+	printpid(tcp, (int) tcp->u_arg[1], PT_TID);
+	tprints(", ");
 	/* signal */
 	printsignal(tcp->u_arg[2]);
 
@@ -624,7 +629,8 @@ print_sigqueueinfo(struct tcb *const tcp, const int sig,
 
 SYS_FUNC(rt_sigqueueinfo)
 {
-	tprintf("%d, ", (int) tcp->u_arg[0]);
+	printpid(tcp, (int) tcp->u_arg[0], PT_TGID);
+	tprints(", ");
 	print_sigqueueinfo(tcp, tcp->u_arg[1], tcp->u_arg[2]);
 
 	return RVAL_DECODED;
@@ -632,7 +638,10 @@ SYS_FUNC(rt_sigqueueinfo)
 
 SYS_FUNC(rt_tgsigqueueinfo)
 {
-	tprintf("%d, %d, ", (int) tcp->u_arg[0], (int) tcp->u_arg[1]);
+	printpid(tcp, (int) tcp->u_arg[0], PT_TGID);
+	tprints(", ");
+	printpid(tcp, (int) tcp->u_arg[1], PT_TID);
+	tprints(", ");
 	print_sigqueueinfo(tcp, tcp->u_arg[2], tcp->u_arg[3]);
 
 	return RVAL_DECODED;
diff --git a/sockaddr.c b/sockaddr.c
index b0046331..fb8887c2 100644
--- a/sockaddr.c
+++ b/sockaddr.c
@@ -416,7 +416,7 @@ print_sockaddr_data_nl(struct tcb *tcp, const void *const buf, const int addrlen
 {
 	const struct sockaddr_nl *const sa_nl = buf;
 
-	PRINT_FIELD_D("", *sa_nl, nl_pid);
+	PRINT_FIELD_TGID("", *sa_nl, nl_pid, tcp);
 	PRINT_FIELD_0X(", ", *sa_nl, nl_groups);
 }
 
diff --git a/tests/kcmp.c b/tests/kcmp.c
index a46da0ed..dc5ba9a4 100644
--- a/tests/kcmp.c
+++ b/tests/kcmp.c
@@ -64,7 +64,26 @@ static const char zero_path[] = "/dev/zero";
 static void
 printpidfd(const char *prefix, pid_t pid, unsigned fd)
 {
-	printf("%s%d", prefix, fd);
+	const char *path = NULL;
+
+# if VERBOSE_FD
+	if (pid == getpid()) {
+		switch (fd)
+		{
+		case NULL_FD:
+			path = null_path;
+			break;
+		case ZERO_FD:
+			path = zero_path;
+			break;
+		}
+	}
+# endif
+
+	if (path)
+		printf("%s%d<%s>", prefix, fd, path);
+	else
+		printf("%s%d", prefix, fd);
 }
 
 /*
@@ -179,7 +198,7 @@ main(void)
 	/* KCMP_FILE is the only type which has additional args */
 	do_kcmp(3141592653U, 2718281828U, ARG_STR(KCMP_FILE), bogus_idx1,
 		bogus_idx2);
-	do_kcmp(-1, -1, ARG_STR(KCMP_FILE), NULL_FD, ZERO_FD);
+	do_kcmp(getpid(), getpid(), ARG_STR(KCMP_FILE), NULL_FD, ZERO_FD);
 
 	/* Types without additional args */
 	do_kcmp(-1, -1, ARG_STR(KCMP_VM), bogus_idx1, bogus_idx2);
@@ -198,7 +217,7 @@ main(void)
 	for (i = 0; i < ARRAY_SIZE(slot_data); i++) {
 		memcpy(slot, slot_data + i, sizeof(*slot));
 
-		do_kcmp(getpid(), getppid(), ARG_STR(KCMP_EPOLL_TFD), NULL_FD,
+		do_kcmp(getpid(), -1, ARG_STR(KCMP_EPOLL_TFD), NULL_FD,
 			(uintptr_t) slot, 1);
 	}
 
diff --git a/util.c b/util.c
index 286c6903..094e5818 100644
--- a/util.c
+++ b/util.c
@@ -392,6 +392,18 @@ printnum_fd(struct tcb *const tcp, const kernel_ulong_t addr)
 	return true;
 }
 
+bool
+printnum_pid(struct tcb *const tcp, const kernel_ulong_t addr, enum pid_type type)
+{
+	int pid;
+	if (umove_or_printaddr(tcp, addr, &pid))
+		return false;
+	tprints("[");
+	printpid(tcp, pid, type);
+	tprints("]");
+	return true;
+}
+
 /**
  * Prints time to a (static internal) buffer and returns pointer to it.
  * Returns NULL if the provided time specification is not correct.
@@ -641,12 +653,8 @@ printed:
 void
 printfd_pid_tracee_ns(struct tcb *tcp, pid_t pid, int fd)
 {
-	/*
-	 * TODO: We want to have the same formatting as printfd here,
-	 *       but we should figure out first which process in strace's
-	 *       PID NS is referred to by pid in tracee's PID NS.
-	 */
-	tprintf("%d", fd);
+	int strace_pid = translate_pid(tcp, pid, PT_TGID, NULL);
+	printfd_pid(tcp, strace_pid, fd);
 }
 
 /*
diff --git a/wait.c b/wait.c
index 2b9f9807..997a711a 100644
--- a/wait.c
+++ b/wait.c
@@ -80,14 +80,8 @@ printwaitn(struct tcb *const tcp,
 	   void (*const print_rusage)(struct tcb *, kernel_ulong_t))
 {
 	if (entering(tcp)) {
-		/* On Linux, kernel-side pid_t is typedef'ed to int
-		 * on all arches. Also, glibc-2.8 truncates wait3 and wait4
-		 * pid argument to int on 64bit arches, producing,
-		 * for example, wait4(4294967295, ...) instead of -1
-		 * in strace. We have to use int here, not long.
-		 */
-		int pid = tcp->u_arg[0];
-		tprintf("%d, ", pid);
+		printpid_tgid_pgid(tcp, tcp->u_arg[0]);
+		tprintf(", ");
 	} else {
 		int status;
 
@@ -108,7 +102,7 @@ printwaitn(struct tcb *const tcp,
 				printaddr(tcp->u_arg[3]);
 		}
 	}
-	return 0;
+	return RVAL_TGID;
 }
 
 SYS_FUNC(waitpid)
@@ -134,10 +128,28 @@ SYS_FUNC(osf_wait4)
 
 SYS_FUNC(waitid)
 {
+	unsigned int idtype = (unsigned int) tcp->u_arg[0];
+	int id = (int) tcp->u_arg[1];
+
 	if (entering(tcp)) {
-		printxval(waitid_types, tcp->u_arg[0], "P_???");
-		int pid = tcp->u_arg[1];
-		tprintf(", %d, ", pid);
+		printxval(waitid_types, idtype, "P_???");
+		tprints(", ");
+		switch (idtype)
+		{
+		case P_PID:
+			printpid(tcp, id, PT_TGID);
+			break;
+		case P_PIDFD:
+			printfd(tcp, id);
+			break;
+		case P_PGID:
+			printpid(tcp, id, PT_PGID);
+			break;
+		default:
+			tprintf("%d", id);
+			break;
+		}
+		tprints(", ");
 	} else {
 		/* siginfo */
 		printsiginfo_at(tcp, tcp->u_arg[2]);
-- 
2.27.0


From uzonyi.akos at gmail.com  Thu Aug  6 19:02:11 2020
From: uzonyi.akos at gmail.com (=?UTF-8?q?=C3=81kos=20Uzonyi?=)
Date: Thu,  6 Aug 2020 21:02:11 +0200
Subject: [PATCH v6 5/5] Add tests for PID namespace translation
In-Reply-To: <20200806190211.118721-1-uzonyi.akos@gmail.com>
References: <20200806190211.118721-1-uzonyi.akos@gmail.com>
Message-ID: <20200806190211.118721-6-uzonyi.akos@gmail.com>

* tests/.gitignore: Add new test executables.
* tests/Makefile.am (check_PROGRAMS): Add new test executables.
(DECODER_TESTS) Add new test files.
* tests/gen_tests.in: Add new tests.
* tests/fcntl-Y.c: New file.
* tests/fcntl64-Y.c: New file.
* tests/fork-Y.awk: New file.
* tests/fork-Y.c: New file.
* tests/fork-Y.test: New file.
* tests/getpgrp-Y.c: New file.
* tests/getpid-Y.c: New file.
* tests/getsid-Y.c: New file.
* tests/gettid-Y.c: New file.
* tests/ioctl_block-Y.c: New file.
* tests/ioctl_block-Y.test: New file.
* tests/ioprio-Y.c: New file.
* tests/kill-Y.c: New file.
* tests/migrate_pages-Y.c: New file.
* tests/move_pages-Y.c: New file.
* tests/net-sockaddr-Y.c: New file.
* tests/netlink_audit-Y.c: New file.
* tests/netlink_audit-Y.test: New file.
* tests/pidfd_open-Y.c: New file.
* tests/pidfd_send_signal-Y.c: New file.
* tests/prlimit64-Y.c: New file.
* tests/process_vm_readv-Y.c: New file.
* tests/process_vm_writev-Y.c: New file.
* tests/rt_sigqueueinfo-Y.c: New file.
* tests/rt_tgsigqueueinfo-Y.c: New file.
* tests/sched_xetaffinity-Y.c: New file.
* tests/sched_xetattr-Y.c: New file.
* tests/sched_xetparam-Y.c: New file.
* tests/sched_xetscheduler-Y.c: New file.
* tests/signal_receive-Y.c: New file.
* tests/so_peercred-Y.c: New file.
* tests/xet_robust_list-Y.c: New file.
* tests/xetpgid-Y.c: New file.
* tests/xetpriority-Y.c: New file.
* tests/fcntl-common.c: Print PID translation string after PIDs.
* tests/fcntl.c: Likewise.
* tests/fcntl64.c: Likewise.
* tests/getpgrp.c: Likewise.
* tests/getpid.c: Likewise.
* tests/getsid.c: Likewise.
* tests/gettid.c: Likewise.
* tests/ioctl_block.c: Likewise.
* tests/ioprio.c: Likewise.
* tests/kcmp.c: Likewise.
* tests/kill.c: Likewise.
* tests/migrate_pages.c: Likewise.
* tests/move_pages.c: Likewise.
* tests/net-sockaddr.c: Likewise.
* tests/netlink_audit.c: Likewise.
* tests/pidfd_open.c: Likewise.
* tests/pidfd_send_signal.c: Likewise.
* tests/prlimit64.c: Likewise.
* tests/process_vm_readv_writev.c: Likewise.
* tests/rt_sigqueueinfo.c: Likewise.
* tests/rt_tgsigqueueinfo.c: Likewise.
* tests/sched_xetaffinity.c: Likewise.
* tests/sched_xetattr.c: Likewise.
* tests/sched_xetparam.c: Likewise.
* tests/sched_xetscheduler.c: Likewise.
* tests/signal_receive.c: Likewise.
* tests/so_peercred.c: Likewise.
* tests/xet_robust_list.c: Likewise.
* tests/xetpgid.c: Likewise.
* tests/xetpriority.c: Likewise.
---
 tests/.gitignore                              | 31 +++++++
 tests/Makefile.am                             | 35 ++++++++
 tests/fcntl--pidns-translation.c              |  2 +
 tests/fcntl-common.c                          | 82 ++++++++++++++-----
 tests/fcntl.c                                 |  1 +
 tests/fcntl64--pidns-translation.c            |  2 +
 tests/fcntl64.c                               |  3 +
 tests/fork--pidns-translation.awk             | 15 ++++
 tests/fork--pidns-translation.c               | 69 ++++++++++++++++
 tests/fork--pidns-translation.test            | 16 ++++
 tests/gen_tests.in                            | 30 ++++++-
 tests/getpgrp--pidns-translation.c            |  2 +
 tests/getpgrp.c                               |  8 +-
 tests/getpid--pidns-translation.c             |  2 +
 tests/getpid.c                                |  8 +-
 tests/getsid--pidns-translation.c             |  2 +
 tests/getsid.c                                |  9 +-
 tests/gettid--pidns-translation.c             |  2 +
 tests/gettid.c                                |  8 +-
 tests/ioctl_block--pidns-translation.c        |  2 +
 tests/ioctl_block--pidns-translation.test     | 24 ++++++
 tests/ioctl_block.c                           | 24 +++++-
 tests/ioprio--pidns-translation.c             |  2 +
 tests/ioprio.c                                | 54 ++++++++----
 tests/kcmp-y--pidns-translation.c             |  2 +
 tests/kcmp.c                                  | 11 ++-
 tests/kill--pidns-translation.c               |  2 +
 tests/kill.c                                  | 12 ++-
 tests/migrate_pages--pidns-translation.c      |  2 +
 tests/migrate_pages.c                         | 17 +++-
 tests/move_pages--pidns-translation.c         |  2 +
 tests/move_pages.c                            | 51 +++++++-----
 tests/net-sockaddr--pidns-translation.c       |  2 +
 tests/net-sockaddr.c                          | 66 +++++++++++++--
 tests/netlink_audit--pidns-translation.c      |  2 +
 tests/netlink_audit--pidns-translation.test   | 13 +++
 tests/netlink_audit.c                         | 11 ++-
 tests/pidfd_open--pidns-translation.c         |  2 +
 tests/pidfd_open.c                            | 21 +++--
 tests/pidfd_send_signal--pidns-translation.c  |  2 +
 tests/pidfd_send_signal.c                     | 13 ++-
 tests/prlimit64--pidns-translation.c          |  2 +
 tests/prlimit64.c                             | 17 +++-
 tests/process_vm_readv--pidns-translation.c   |  2 +
 tests/process_vm_readv_writev.c               | 27 +++---
 tests/process_vm_writev--pidns-translation.c  |  2 +
 tests/rt_sigqueueinfo--pidns-translation.c    |  2 +
 tests/rt_sigqueueinfo.c                       | 15 +++-
 tests/rt_tgsigqueueinfo--pidns-translation.c  |  2 +
 tests/rt_tgsigqueueinfo.c                     | 26 ++++--
 tests/sched_xetaffinity--pidns-translation.c  |  2 +
 tests/sched_xetaffinity.c                     | 31 ++++---
 tests/sched_xetattr--pidns-translation.c      |  2 +
 tests/sched_xetattr.c                         | 47 ++++++++++-
 tests/sched_xetparam--pidns-translation.c     |  2 +
 tests/sched_xetparam.c                        | 20 +++--
 tests/sched_xetscheduler--pidns-translation.c |  2 +
 tests/sched_xetscheduler.c                    | 44 ++++++----
 tests/signal_receive--pidns-translation.c     |  2 +
 tests/signal_receive.c                        | 22 +++--
 tests/so_peercred--pidns-translation.c        |  2 +
 tests/so_peercred.c                           | 22 +++++
 tests/xet_robust_list--pidns-translation.c    |  2 +
 tests/xet_robust_list.c                       | 18 +++-
 tests/xetpgid--pidns-translation.c            |  2 +
 tests/xetpgid.c                               | 21 +++--
 tests/xetpriority--pidns-translation.c        |  2 +
 tests/xetpriority.c                           | 20 ++++-
 68 files changed, 854 insertions(+), 168 deletions(-)
 create mode 100644 tests/fcntl--pidns-translation.c
 create mode 100644 tests/fcntl64--pidns-translation.c
 create mode 100644 tests/fork--pidns-translation.awk
 create mode 100644 tests/fork--pidns-translation.c
 create mode 100755 tests/fork--pidns-translation.test
 create mode 100644 tests/getpgrp--pidns-translation.c
 create mode 100644 tests/getpid--pidns-translation.c
 create mode 100644 tests/getsid--pidns-translation.c
 create mode 100644 tests/gettid--pidns-translation.c
 create mode 100644 tests/ioctl_block--pidns-translation.c
 create mode 100755 tests/ioctl_block--pidns-translation.test
 create mode 100644 tests/ioprio--pidns-translation.c
 create mode 100644 tests/kcmp-y--pidns-translation.c
 create mode 100644 tests/kill--pidns-translation.c
 create mode 100644 tests/migrate_pages--pidns-translation.c
 create mode 100644 tests/move_pages--pidns-translation.c
 create mode 100644 tests/net-sockaddr--pidns-translation.c
 create mode 100644 tests/netlink_audit--pidns-translation.c
 create mode 100755 tests/netlink_audit--pidns-translation.test
 create mode 100644 tests/pidfd_open--pidns-translation.c
 create mode 100644 tests/pidfd_send_signal--pidns-translation.c
 create mode 100644 tests/prlimit64--pidns-translation.c
 create mode 100644 tests/process_vm_readv--pidns-translation.c
 create mode 100644 tests/process_vm_writev--pidns-translation.c
 create mode 100644 tests/rt_sigqueueinfo--pidns-translation.c
 create mode 100644 tests/rt_tgsigqueueinfo--pidns-translation.c
 create mode 100644 tests/sched_xetaffinity--pidns-translation.c
 create mode 100644 tests/sched_xetattr--pidns-translation.c
 create mode 100644 tests/sched_xetparam--pidns-translation.c
 create mode 100644 tests/sched_xetscheduler--pidns-translation.c
 create mode 100644 tests/signal_receive--pidns-translation.c
 create mode 100644 tests/so_peercred--pidns-translation.c
 create mode 100644 tests/xet_robust_list--pidns-translation.c
 create mode 100644 tests/xetpgid--pidns-translation.c
 create mode 100644 tests/xetpriority--pidns-translation.c

diff --git a/tests/.gitignore b/tests/.gitignore
index 0031d04d..4d1153fc 100644
--- a/tests/.gitignore
+++ b/tests/.gitignore
@@ -116,7 +116,9 @@ fchown
 fchown32
 fchownat
 fcntl
+fcntl--pidns-translation
 fcntl64
+fcntl64--pidns-translation
 fdatasync
 fflush
 file_handle
@@ -126,6 +128,7 @@ filter-unavailable
 finit_module
 flock
 fork-f
+fork--pidns-translation
 fsconfig
 fsconfig-P
 fsmount
@@ -168,7 +171,9 @@ getgroups
 getgroups32
 getpeername
 getpgrp
+getpgrp--pidns-translation
 getpid
+getpid--pidns-translation
 getppid
 getrandom
 getresgid
@@ -178,8 +183,10 @@ getresuid32
 getrlimit
 getrusage
 getsid
+getsid--pidns-translation
 getsockname
 gettid
+gettid--pidns-translation
 getuid
 getuid32
 getxgid
@@ -200,6 +207,7 @@ io_uring_register
 io_uring_setup
 ioctl
 ioctl_block
+ioctl_block--pidns-translation
 ioctl_dm
 ioctl_dm-v
 ioctl_evdev
@@ -275,6 +283,7 @@ ioctl_watchdog
 ioperm
 iopl
 ioprio
+ioprio--pidns-translation
 ioprio-Xabbrev
 ioprio-Xraw
 ioprio-Xverbose
@@ -299,6 +308,7 @@ ipc_shm-Xverbose
 is_linux_mips_n64
 kcmp
 kcmp-y
+kcmp-y--pidns-translation
 kern_features
 kernel_version
 kernel_version-Xabbrev
@@ -311,6 +321,7 @@ keyctl-Xabbrev
 keyctl-Xraw
 keyctl-Xverbose
 kill
+kill--pidns-translation
 kill_child
 ksysent
 ksysent.h
@@ -340,6 +351,7 @@ memfd_create-Xabbrev
 memfd_create-Xraw
 memfd_create-Xverbose
 migrate_pages
+migrate_pages--pidns-translation
 mincore
 mkdir
 mkdirat
@@ -371,6 +383,7 @@ move_pages
 move_pages-Xabbrev
 move_pages-Xraw
 move_pages-Xverbose
+move_pages--pidns-translation
 mq
 mq_sendrecv
 mq_sendrecv-read
@@ -391,6 +404,7 @@ net-packet_mreq-Xabbrev
 net-packet_mreq-Xraw
 net-packet_mreq-Xverbose
 net-sockaddr
+net-sockaddr--pidns-translation
 net-tpacket_req
 net-tpacket_stats
 net-tpacket_stats-success
@@ -400,6 +414,7 @@ net-yy-inet6
 net-yy-netlink
 net-yy-unix
 netlink_audit
+netlink_audit--pidns-translation
 netlink_crypto
 netlink_generic
 netlink_inet_diag
@@ -507,7 +522,9 @@ pidfd_open--decode-fd-socket
 pidfd_open-P
 pidfd_open-y
 pidfd_open-yy
+pidfd_open--pidns-translation
 pidfd_send_signal
+pidfd_send_signal--pidns-translation
 pipe
 pipe2
 pkey_alloc
@@ -546,8 +563,11 @@ printstrn-umoven
 printstrn-umoven-peekdata
 printstrn-umoven-undumpable
 prlimit64
+prlimit64--pidns-translation
 process_vm_readv
+process_vm_readv--pidns-translation
 process_vm_writev
+process_vm_writev--pidns-translation
 pselect6
 ptrace
 ptrace_syscall_info
@@ -597,10 +617,12 @@ rt_sigaction
 rt_sigpending
 rt_sigprocmask
 rt_sigqueueinfo
+rt_sigqueueinfo--pidns-translation
 rt_sigreturn
 rt_sigsuspend
 rt_sigtimedwait
 rt_tgsigqueueinfo
+rt_tgsigqueueinfo--pidns-translation
 run_expect_termsig
 s390_guarded_storage
 s390_guarded_storage-v
@@ -611,9 +633,13 @@ s390_sthyi-v
 sched_get_priority_mxx
 sched_rr_get_interval
 sched_xetaffinity
+sched_xetaffinity--pidns-translation
 sched_xetattr
+sched_xetattr--pidns-translation
 sched_xetparam
+sched_xetparam--pidns-translation
 sched_xetscheduler
+sched_xetscheduler--pidns-translation
 sched_yield
 scm_rights
 scno.h
@@ -669,6 +695,7 @@ sigaltstack
 siginfo
 signal
 signal_receive
+signal_receive--pidns-translation
 signalfd4
 sigpending
 sigprocmask
@@ -681,6 +708,7 @@ so_peercred
 so_peercred-Xabbrev
 so_peercred-Xraw
 so_peercred-Xverbose
+so_peercred--pidns-translation
 sock_filter-v
 sock_filter-v-Xabbrev
 sock_filter-v-Xraw
@@ -783,9 +811,12 @@ waitpid
 xattr
 xattr-strings
 xet_robust_list
+xet_robust_list--pidns-translation
 xet_thread_area_x86
 xetitimer
 xetpgid
+xetpgid--pidns-translation
 xetpriority
+xetpriority--pidns-translation
 xettimeofday
 zeroargc
diff --git a/tests/Makefile.am b/tests/Makefile.am
index 7a583a3a..05e350bd 100644
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@@ -109,17 +109,25 @@ check_PROGRAMS = $(PURE_EXECUTABLES) \
 	delay \
 	execve-v \
 	execveat-v \
+	fcntl--pidns-translation \
+	fcntl64--pidns-translation \
 	filter_seccomp-flag \
 	filter_seccomp-perf \
 	filter-unavailable \
 	fork-f \
+	fork--pidns-translation \
 	fsync-y \
 	get_process_reaper \
+	getpgrp--pidns-translation	\
 	getpid	\
+	getpid--pidns-translation	\
 	getppid	\
+	getsid--pidns-translation \
 	gettid \
+	gettid--pidns-translation \
 	inject-nf \
 	int_0x80 \
+	ioctl_block--pidns-translation \
 	ioctl_dm-v \
 	ioctl_evdev-success \
 	ioctl_evdev-success-Xabbrev \
@@ -150,18 +158,25 @@ check_PROGRAMS = $(PURE_EXECUTABLES) \
 	ioctl_v4l2-success-v-Xabbrev \
 	ioctl_v4l2-success-v-Xraw \
 	ioctl_v4l2-success-v-Xverbose \
+	ioprio--pidns-translation \
 	is_linux_mips_n64 \
+	kcmp-y--pidns-translation \
 	kill_child \
+	kill--pidns-translation \
 	ksysent \
 	list_sigaction_signum \
 	localtime \
 	looping_threads \
+	migrate_pages--pidns-translation \
 	mmsg-silent \
 	mmsg_name-v \
+	move_pages--pidns-translation \
 	msg_control-v \
 	net-accept-connect \
+	net-sockaddr--pidns-translation \
 	net-tpacket_stats-success \
 	nlattr_ifla_xdp-y \
+	netlink_audit--pidns-translation \
 	netlink_inet_diag \
 	netlink_netlink_diag \
 	netlink_unix_diag \
@@ -173,14 +188,19 @@ check_PROGRAMS = $(PURE_EXECUTABLES) \
 	pc \
 	perf_event_open_nonverbose \
 	perf_event_open_unabbrev \
+	pidfd_open--pidns-translation \
+	pidfd_send_signal--pidns-translation \
 	poll-P \
 	ppoll-P \
 	ppoll-v \
+	prlimit64--pidns-translation \
 	prctl-seccomp-filter-v \
 	prctl-seccomp-strict \
 	prctl-spec-inject \
 	print_maxfd \
 	print_ppid_tracerpid \
+	process_vm_readv--pidns-translation \
+	process_vm_writev--pidns-translation \
 	qual_fault \
 	qual_inject-error-signal \
 	qual_inject-retval \
@@ -194,7 +214,13 @@ check_PROGRAMS = $(PURE_EXECUTABLES) \
 	quotactl-xfs-v \
 	redirect-fds \
 	restart_syscall \
+	rt_sigqueueinfo--pidns-translation \
+	rt_tgsigqueueinfo--pidns-translation \
 	run_expect_termsig \
+	sched_xetaffinity--pidns-translation \
+	sched_xetattr--pidns-translation \
+	sched_xetparam--pidns-translation \
+	sched_xetscheduler--pidns-translation \
 	scm_rights \
 	seccomp-filter-v \
 	seccomp-strict \
@@ -204,12 +230,14 @@ check_PROGRAMS = $(PURE_EXECUTABLES) \
 	set_sigign \
 	setpgrp-exec \
 	signal_receive \
+	signal_receive--pidns-translation \
 	sleep \
 	stack-fcall \
 	stack-fcall-attach \
 	stack-fcall-mangled \
 	status-none-threads \
 	status-unfinished-threads \
+	so_peercred--pidns-translation \
 	syslog-success \
 	threads-execve \
 	threads-execve--quiet-thread-execve \
@@ -223,6 +251,9 @@ check_PROGRAMS = $(PURE_EXECUTABLES) \
 	vfork-f \
 	wait4-v \
 	waitid-v \
+	xetpgid--pidns-translation \
+	xetpriority--pidns-translation \
+	xet_robust_list--pidns-translation \
 	zeroargc \
 	# end of check_PROGRAMS
 
@@ -310,6 +341,7 @@ DECODER_TESTS = \
 	int_0x80.test \
 	inotify_init-y.test \
 	ioctl.test \
+	ioctl_block--pidns-translation.test \
 	ioctl_evdev-success.test \
 	ipc_msgbuf.test \
 	kern_features-fault.test \
@@ -381,12 +413,14 @@ MISC_TESTS = \
 	filtering_fd-syntax.test \
 	filtering_syscall-syntax.test \
 	first_exec_failure.test \
+	fork--pidns-translation.test \
 	get_regs.test \
 	inject-nf.test \
 	interactive_block.test \
 	kill_child.test \
 	localtime.test \
 	looping_threads.test \
+	netlink_audit--pidns-translation.test \
 	opipe.test \
 	options-syntax.test \
 	pc.test \
@@ -467,6 +501,7 @@ EXTRA_DIST = \
 	filter_seccomp.in \
 	filter_seccomp.sh \
 	filter-unavailable.expected \
+	fork--pidns-translation.awk \
 	fstatat.c \
 	fstatx.c \
 	gen_pure_executables.sh \
diff --git a/tests/fcntl--pidns-translation.c b/tests/fcntl--pidns-translation.c
new file mode 100644
index 00000000..e249424a
--- /dev/null
+++ b/tests/fcntl--pidns-translation.c
@@ -0,0 +1,2 @@
+#define PIDNS_TRANSLATION
+#include "fcntl.c"
diff --git a/tests/fcntl-common.c b/tests/fcntl-common.c
index 27694326..d9e29939 100644
--- a/tests/fcntl-common.c
+++ b/tests/fcntl-common.c
@@ -13,6 +13,8 @@
 #include <unistd.h>
 #include <assert.h>
 #include "flock.h"
+#include "pidns.h"
+#include "scno.h"
 
 #define FILE_LEN 4096
 
@@ -48,12 +50,14 @@ test_flock_einval(const int cmd, const char *name)
 	fl->l_len = (TYPEOF_FLOCK_OFF_T) 0xdefaced2cafef00dULL;
 
 	invoke_test_syscall(0, cmd, fl);
+	pidns_print_leader();
 	printf("%s(0, %s, {l_type=F_RDLCK, l_whence=SEEK_SET"
 	       ", l_start=%jd, l_len=%jd}) = %s\n", TEST_SYSCALL_STR, name,
 	       (intmax_t) fl->l_start, (intmax_t) fl->l_len, errstr);
 
 	void *const bad_addr = (void *) fl + 1;
 	invoke_test_syscall(0, cmd, bad_addr);
+	pidns_print_leader();
 	printf("%s(0, %s, %p) = %s\n",
 	       TEST_SYSCALL_STR, name, bad_addr, errstr);
 }
@@ -72,12 +76,14 @@ test_flock64_einval(const int cmd, const char *name)
 	fl->l_len = (TYPEOF_FLOCK_OFF_T) 0xdefaced2cafef00dULL;
 
 	invoke_test_syscall(0, cmd, fl);
+	pidns_print_leader();
 	printf("%s(0, %s, {l_type=F_RDLCK, l_whence=SEEK_SET"
 	       ", l_start=%jd, l_len=%jd}) = %s\n", TEST_SYSCALL_STR, name,
 	       (intmax_t) fl->l_start, (intmax_t) fl->l_len, errstr);
 
 	void *const bad_addr = (void *) fl + 1;
 	invoke_test_syscall(0, cmd, bad_addr);
+	pidns_print_leader();
 	printf("%s(0, %s, %p) = %s\n",
 	       TEST_SYSCALL_STR, name, bad_addr, errstr);
 }
@@ -94,6 +100,7 @@ test_flock(void)
 	fl->l_len = FILE_LEN;
 
 	long rc = invoke_test_syscall(0, F_SETLK, fl);
+	pidns_print_leader();
 	printf("%s(0, F_SETLK, {l_type=F_RDLCK, l_whence=SEEK_SET"
 	       ", l_start=0, l_len=%d}) = %s\n",
 	       TEST_SYSCALL_STR, FILE_LEN, errstr);
@@ -101,11 +108,13 @@ test_flock(void)
 		return;
 
 	invoke_test_syscall(0, F_GETLK, fl);
+	pidns_print_leader();
 	printf("%s(0, F_GETLK, {l_type=F_UNLCK, l_whence=SEEK_SET"
 	       ", l_start=0, l_len=%d, l_pid=0}) = 0\n",
 	       TEST_SYSCALL_STR, FILE_LEN);
 
 	invoke_test_syscall(0, F_SETLKW, fl);
+	pidns_print_leader();
 	printf("%s(0, F_SETLKW, {l_type=F_UNLCK, l_whence=SEEK_SET"
 	       ", l_start=0, l_len=%d}) = 0\n",
 	       TEST_SYSCALL_STR, FILE_LEN);
@@ -124,6 +133,7 @@ test_flock64_ofd(void)
 	fl->l_len = FILE_LEN;
 
 	long rc = invoke_test_syscall(0, F_OFD_SETLK, fl);
+	pidns_print_leader();
 	printf("%s(0, F_OFD_SETLK, {l_type=F_RDLCK, l_whence=SEEK_SET"
 	       ", l_start=0, l_len=%d}) = %s\n",
 	       TEST_SYSCALL_STR, FILE_LEN, errstr);
@@ -131,11 +141,13 @@ test_flock64_ofd(void)
 		return;
 
 	invoke_test_syscall(0, F_OFD_GETLK, fl);
+	pidns_print_leader();
 	printf("%s(0, F_OFD_GETLK, {l_type=F_UNLCK, l_whence=SEEK_SET"
 	       ", l_start=0, l_len=%d, l_pid=0}) = 0\n",
 	       TEST_SYSCALL_STR, FILE_LEN);
 
 	invoke_test_syscall(0, F_OFD_SETLKW, fl);
+	pidns_print_leader();
 	printf("%s(0, F_OFD_SETLKW, {l_type=F_UNLCK, l_whence=SEEK_SET"
 	       ", l_start=0, l_len=%d}) = 0\n",
 	       TEST_SYSCALL_STR, FILE_LEN);
@@ -167,18 +179,21 @@ test_flock64(void)
 static long
 test_f_owner_ex_type_pid(const int cmd, const char *const cmd_name,
 			 const int type, const char *const type_name,
-			 pid_t pid)
+			 enum pid_type pid_type, pid_t pid)
 {
 	TAIL_ALLOC_OBJECT_CONST_PTR(struct_kernel_f_owner_ex, fo);
 
 	fo->type = type;
 	fo->pid = pid;
 	long rc = invoke_test_syscall(0, cmd, fo);
-	printf("%s(0, %s, {type=%s, pid=%d}) = %s\n",
-	       TEST_SYSCALL_STR, cmd_name, type_name, fo->pid, errstr);
+	pidns_print_leader();
+	printf("%s(0, %s, {type=%s, pid=%d%s}) = %s\n",
+	       TEST_SYSCALL_STR, cmd_name, type_name,
+	       fo->pid, pidns_pid2str(pid_type), errstr);
 
 	void *bad_addr = (void *) fo + 1;
 	invoke_test_syscall(0, cmd, bad_addr);
+	pidns_print_leader();
 	printf("%s(0, %s, %p) = %s\n",
 	       TEST_SYSCALL_STR, cmd_name, bad_addr, errstr);
 
@@ -187,35 +202,39 @@ test_f_owner_ex_type_pid(const int cmd, const char *const cmd_name,
 
 static void
 test_f_owner_ex_umove_or_printaddr(const int type, const char *const type_name,
-				   pid_t pid)
+				   enum pid_type pid_type, pid_t pid)
 {
 	long rc = test_f_owner_ex_type_pid(ARG_STR(F_SETOWN_EX),
-					   type, type_name, pid);
+					   type, type_name, pid_type, pid);
 	if (!rc)
 		test_f_owner_ex_type_pid(ARG_STR(F_GETOWN_EX),
-					 type, type_name, pid);
+					 type, type_name, pid_type, pid);
 }
 
 static void
 test_f_owner_ex(void)
 {
-	static const struct {
+	struct {
 		int type;
 		const char *type_name;
-		pid_t pid[2];
+		enum pid_type pid_type;
+		pid_t pid;
 	} a[] = {
-		{ ARG_STR(F_OWNER_TID), { 1234567890, 20 } },
-		{ ARG_STR(F_OWNER_PID), { 1298126790, 30 } },
-		{ ARG_STR(F_OWNER_PGRP), { 1294567890, 40 } }
+		{ ARG_STR(F_OWNER_TID), PT_NONE, 1234567890 },
+		{ ARG_STR(F_OWNER_PID), PT_NONE, 1234567890 },
+		{ ARG_STR(F_OWNER_PGRP), PT_NONE, 1234567890 },
+		{ ARG_STR(F_OWNER_TID), PT_TID, 0 },
+		{ ARG_STR(F_OWNER_PID), PT_TGID, 0 },
+		{ ARG_STR(F_OWNER_PGRP), PT_PGID, 0 },
 	};
 
-	for (unsigned int i = 0; i < ARRAY_SIZE(a); i++) {
-		for (unsigned int j = 0; j < ARRAY_SIZE(a[0].pid); j++) {
-			test_f_owner_ex_umove_or_printaddr(a[i].type,
-							   a[i].type_name,
-							   a[i].pid[j]);
-		}
-	}
+	a[3].pid = syscall(__NR_gettid);
+	a[4].pid = getpid();
+	a[5].pid = getpgid(0);
+
+	for (unsigned int i = 0; i < ARRAY_SIZE(a); i++)
+		test_f_owner_ex_umove_or_printaddr(a[i].type, a[i].type_name,
+			a[i].pid_type, a[i].pid);
 }
 #endif /* TEST_F_OWNER_EX */
 
@@ -228,6 +247,23 @@ struct fcntl_cmd_check {
 	void (*print_flags)(long rc);
 };
 
+static void
+test_xetown(void)
+{
+	const int pid = getpid();
+	const char *pid_str = pidns_pid2str(PT_TGID);
+
+	invoke_test_syscall(0, F_SETOWN, (void *) (intptr_t) pid);
+	pidns_print_leader();
+	printf("%s(0, F_SETOWN, %d%s) = %s\n",
+		TEST_SYSCALL_STR, pid, pid_str, errstr);
+
+	invoke_test_syscall(0, F_GETOWN, NULL);
+	pidns_print_leader();
+	printf("%s(0, F_GETOWN) = %d%s\n",
+		TEST_SYSCALL_STR, pid, pid_str);
+}
+
 static void
 print_retval_flags(const struct fcntl_cmd_check *check, long rc)
 {
@@ -243,12 +279,14 @@ static void
 test_other_set_cmd(const struct fcntl_cmd_check *check)
 {
 	invoke_test_syscall(check->fd, check->cmd, (void *) check->arg);
+	pidns_print_leader();
 	printf("%s(%d, %s, %s) = %s\n",
 	       TEST_SYSCALL_STR, check->fd,
 	       check->cmd_str, check->arg_str, errstr);
 
 	/* bad file fd */
 	invoke_test_syscall(-1, check->cmd, (void *) check->arg);
+	pidns_print_leader();
 	printf("%s(-1, %s, %s) = %s\n",
 	       TEST_SYSCALL_STR, check->cmd_str,
 	       check->arg_str, errstr);
@@ -258,12 +296,14 @@ static void
 test_other_get_cmd(const struct fcntl_cmd_check *check)
 {
 	long rc = invoke_test_syscall(check->fd, check->cmd, NULL);
+	pidns_print_leader();
 	printf("%s(%d, %s) = ",
 	       TEST_SYSCALL_STR, check->fd, check->cmd_str);
 	print_retval_flags(check, rc);
 
 	/* bad file fd */
 	invoke_test_syscall(-1, check->cmd, NULL);
+	pidns_print_leader();
 	printf("%s(-1, %s) = %s\n",
 	       TEST_SYSCALL_STR, check->cmd_str, errstr);
 }
@@ -315,7 +355,6 @@ test_fcntl_others(void)
 {
 	static const struct fcntl_cmd_check set_checks[] = {
 		{ 0, ARG_STR(F_SETFD), ARG_STR(FD_CLOEXEC) },
-		{ 0, ARG_STR(F_SETOWN), ARG_STR(20) },
 #ifdef F_SETPIPE_SZ
 		{ 0, ARG_STR(F_SETPIPE_SZ), ARG_STR(4097) },
 #endif
@@ -336,7 +375,6 @@ test_fcntl_others(void)
 	static const struct fcntl_cmd_check get_checks[] = {
 		{ 0, ARG_STR(F_GETFD), .print_flags = print_flags_getfd },
 		{ 1, ARG_STR(F_GETFD), .print_flags = print_flags_getfd },
-		{ 0, ARG_STR(F_GETOWN) },
 #ifdef F_GETPIPE_SZ
 		{ 0, ARG_STR(F_GETPIPE_SZ) },
 #endif
@@ -360,6 +398,8 @@ create_sample(void)
 int
 main(void)
 {
+	PIDNS_TEST_INIT;
+
 	create_sample();
 	test_flock();
 	test_flock64();
@@ -367,7 +407,9 @@ main(void)
 	test_f_owner_ex();
 #endif
 	test_fcntl_others();
+	test_xetown();
 
+	pidns_print_leader();
 	puts("+++ exited with 0 +++");
 	return 0;
 }
diff --git a/tests/fcntl.c b/tests/fcntl.c
index f38b8afb..673c06e4 100644
--- a/tests/fcntl.c
+++ b/tests/fcntl.c
@@ -24,6 +24,7 @@ test_flock64_undecoded(const int cmd, const char *name)
 		.l_len = 0xdefaced2cafef00dULL
 	};
 	invoke_test_syscall(0, cmd, &fl);
+	pidns_print_leader();
 	printf("%s(0, %s, %p) = %s\n",
 	       TEST_SYSCALL_STR, name, &fl, errstr);
 }
diff --git a/tests/fcntl64--pidns-translation.c b/tests/fcntl64--pidns-translation.c
new file mode 100644
index 00000000..c6fdadd1
--- /dev/null
+++ b/tests/fcntl64--pidns-translation.c
@@ -0,0 +1,2 @@
+#define PIDNS_TRANSLATION
+#include "fcntl64.c"
diff --git a/tests/fcntl64.c b/tests/fcntl64.c
index 78e53b0d..f7b3f2fb 100644
--- a/tests/fcntl64.c
+++ b/tests/fcntl64.c
@@ -27,6 +27,7 @@ test_flock64_lk64(void)
 	fl->l_len = FILE_LEN;
 
 	long rc = invoke_test_syscall(0, F_SETLK64, fl);
+	pidns_print_leader();
 	printf("%s(0, F_SETLK64, {l_type=F_RDLCK, l_whence=SEEK_SET"
 	       ", l_start=0, l_len=%d}) = %s\n",
 	       TEST_SYSCALL_STR, FILE_LEN, errstr);
@@ -35,11 +36,13 @@ test_flock64_lk64(void)
 		return;
 
 	invoke_test_syscall(0, F_GETLK64, fl);
+	pidns_print_leader();
 	printf("%s(0, F_GETLK64, {l_type=F_UNLCK, l_whence=SEEK_SET"
 	       ", l_start=0, l_len=%d, l_pid=0}) = 0\n",
 	       TEST_SYSCALL_STR, FILE_LEN);
 
 	invoke_test_syscall(0, F_SETLKW64, fl);
+	pidns_print_leader();
 	printf("%s(0, F_SETLKW64, {l_type=F_UNLCK, l_whence=SEEK_SET"
 	       ", l_start=0, l_len=%d}) = 0\n",
 	       TEST_SYSCALL_STR, FILE_LEN);
diff --git a/tests/fork--pidns-translation.awk b/tests/fork--pidns-translation.awk
new file mode 100644
index 00000000..ef6858f4
--- /dev/null
+++ b/tests/fork--pidns-translation.awk
@@ -0,0 +1,15 @@
+/fork/ {
+        match($0, "([0-9]+) in strace\x27s PID NS", a);
+        if (a[1])
+                fork_pid = a[1]
+}
+
+/exited with 0/ {
+        if (!exit_pid)
+                exit_pid = $1
+}
+
+END {
+        if (!fork_pid || !exit_pid || fork_pid != exit_pid)
+                exit 1
+}
diff --git a/tests/fork--pidns-translation.c b/tests/fork--pidns-translation.c
new file mode 100644
index 00000000..73c39d5d
--- /dev/null
+++ b/tests/fork--pidns-translation.c
@@ -0,0 +1,69 @@
+/*
+ * Test PID namespace translation
+ *
+ * Copyright (c) 2020 ?kos Uzonyi <uzonyi.akos at gmail.com>
+ * All rights reserved.
+ *
+ * SPDX-License-Identifier: LGPL-2.1-or-later
+ */
+
+#include "tests.h"
+#include "scno.h"
+#include "pidns.h"
+
+#ifdef __NR_fork
+
+#include <errno.h>
+#include <limits.h>
+#include <sched.h>
+#include <signal.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <sys/wait.h>
+#include <unistd.h>
+#include <linux/sched.h>
+
+static int
+fork_chain(int depth)
+{
+	if (!depth)
+		return 0;
+
+	int pid = syscall(__NR_fork);
+	if (pid < 0)
+		return errno;
+
+	if (!pid)
+		_exit(fork_chain(depth - 1));
+
+	int status;
+	if (wait(&status) < 0)
+		return errno;
+
+	if (!WIFEXITED(status))
+		return -1;
+
+	return WEXITSTATUS(status);
+}
+
+int main(void)
+{
+	check_ns_ioctl();
+
+	if (unshare(CLONE_NEWPID | CLONE_NEWUSER) < 0) {
+		if (errno == EPERM)
+			perror_msg_and_skip("unshare");
+
+		perror_msg_and_fail("unshare");
+	}
+
+	errno = fork_chain(2);
+	if (errno)
+		perror("fork_chain");
+}
+
+#else
+
+SKIP_MAIN_UNDEFINED("__NR_fork")
+
+#endif
diff --git a/tests/fork--pidns-translation.test b/tests/fork--pidns-translation.test
new file mode 100755
index 00000000..fa7ecda5
--- /dev/null
+++ b/tests/fork--pidns-translation.test
@@ -0,0 +1,16 @@
+#!/bin/sh
+#
+# Check pidns translation of fork's return value.
+#
+# Copyright (c) 2020 The strace developers.
+# All rights reserved.
+#
+# SPDX-License-Identifier: LGPL-2.1-or-later
+
+. "${srcdir=.}/init.sh"
+
+require_min_kernel_version_or_skip 4.9
+
+run_prog
+run_strace -a6 --pidns-translation -f -e trace=fork $args
+match_awk
diff --git a/tests/gen_tests.in b/tests/gen_tests.in
index 6f8e1420..56e5b5e1 100644
--- a/tests/gen_tests.in
+++ b/tests/gen_tests.in
@@ -93,7 +93,9 @@ fchown	-a16
 fchown32	-a18
 fchownat
 fcntl	-a8
+fcntl--pidns-translation	test_pidns -a8 -e trace=fcntl
 fcntl64	-a8
+fcntl64--pidns-translation	test_pidns -a8 -e trace=fcntl64
 fdatasync	-a14
 file_handle	-e trace=name_to_handle_at,open_by_handle_at
 file_ioctl	+ioctl.test
@@ -147,7 +149,9 @@ getgroups	-a17
 getgroups32	-a19
 getpeername	-a27
 getpgrp	-a10
+getpgrp--pidns-translation	test_pidns -e trace=getpgrp -a10
 getpid	-a9
+getpid--pidns-translation	test_pidns -e trace=getpid -a9
 getppid	-a10
 getrandom	-a32 -s3
 getresgid	-a25
@@ -157,8 +161,10 @@ getresuid32	-a27
 getrlimit	-a27
 getrusage	-v
 getsid	-a10
+getsid--pidns-translation	test_pidns -e trace=getsid -a10
 getsockname	-a27
 gettid	-a9
+gettid--pidns-translation	test_pidns -e trace=gettid -a9
 getuid-creds	+getuid.test
 getuid32	+getuid.test
 getuid32-creds	+getuid.test
@@ -250,6 +256,7 @@ ioctl_watchdog	+ioctl.test
 ioperm	-a27
 iopl	-a8
 ioprio	-a18 -e trace=ioprio_get,ioprio_set
+ioprio--pidns-translation	test_pidns -a18 -e trace=ioprio_get,ioprio_set
 ioprio-Xabbrev	-a18 -e trace=ioprio_get,ioprio_set -Xabbrev
 ioprio-Xraw	-a18 -e trace=ioprio_get,ioprio_set -Xraw
 ioprio-Xverbose	-a18 -e trace=ioprio_get,ioprio_set -Xverbose
@@ -272,6 +279,7 @@ ipc_shm-Xraw	+ipc.sh -Xraw -a19
 ipc_shm-Xverbose	+ipc.sh -Xverbose -a34
 kcmp	-a22
 kcmp-y	-a22 -y -e trace=kcmp
+kcmp-y--pidns-translation	test_pidns -a22 -y -e trace=kcmp
 kern_features -a16
 kernel_version	-a16 -v -e trace=bpf
 kernel_version-Xabbrev	-a16 -Xabbrev -v -e trace=bpf
@@ -284,6 +292,7 @@ keyctl-Xabbrev	-a31 -s10 -e trace=keyctl -Xabbrev
 keyctl-Xraw	-a13 -s10 -e trace=keyctl -Xraw
 keyctl-Xverbose	-a41 -s10 -e trace=keyctl -Xverbose
 kill	-a12 -esignal=none
+kill--pidns-translation	test_pidns -a12 -e trace=kill -esignal=none
 ksysent	../$NAME
 lchown	-a30
 lchown32	-a32
@@ -305,6 +314,7 @@ memfd_create-Xabbrev	-Xabbrev -e trace=memfd_create
 memfd_create-Xraw	-a30 -Xraw -e trace=memfd_create
 memfd_create-Xverbose	-Xverbose -e trace=memfd_create
 migrate_pages	-a33
+migrate_pages--pidns-translation	test_pidns -a33 -e trace=migrate_pages
 mincore	-a22
 mkdir	-a20
 mkdirat	-a28
@@ -335,6 +345,7 @@ move_pages	-s3
 move_pages-Xabbrev	-s3 -e trace=move_pages -Xabbrev
 move_pages-Xraw	-s3 -a36 -e trace=move_pages -Xraw
 move_pages-Xverbose	-s3 -e trace=move_pages -Xverbose
+move_pages--pidns-translation	test_pidns -s3 -e trace=move_pages
 mq	-a32 -e trace=mq_getsetattr,mq_open,mq_unlink
 mq_sendrecv	-a14 -e trace=mq_open,mq_notify,mq_timedsend,mq_timedreceive,mq_unlink
 mq_sendrecv-read	-eread=0 -a14 -e trace=mq_open,mq_notify,mq_timedsend,mq_timedreceive,mq_unlink
@@ -354,6 +365,7 @@ net-packet_mreq-Xabbrev	-e trace=setsockopt -Xabbrev
 net-packet_mreq-Xraw	-e trace=setsockopt -Xraw
 net-packet_mreq-Xverbose	-e trace=setsockopt -Xverbose
 net-sockaddr	-a24 -e trace=connect
+net-sockaddr--pidns-translation	test_pidns -a24 -e trace=connect
 net-tpacket_req -e trace=setsockopt
 net-tpacket_stats -e trace=getsockopt
 net-yy-inet6	+net-yy-inet.test
@@ -457,7 +469,9 @@ pidfd_open--decode-fd-socket	-a17 -e decode-fd=socket -e trace=pidfd_open
 pidfd_open-P	-a17 -P /dev/full -e trace=pidfd_open
 pidfd_open-y	-a17 -y -e trace=pidfd_open
 pidfd_open-yy	-a17 -yy -e trace=pidfd_open
+pidfd_open--pidns-translation	test_pidns -a17 -e trace=pidfd_open
 pidfd_send_signal
+pidfd_send_signal--pidns-translation test_pidns -e trace=pidfd_send_signal
 pipe2	-a15
 pkey_alloc	-a17
 pkey_free	-a13
@@ -480,8 +494,11 @@ printstrn-umoven	-s4096 -e signal=none -e trace=add_key
 printstrn-umoven-peekdata	-e signal=none -e trace=add_key
 printstrn-umoven-undumpable	-e signal=none -e trace=add_key
 prlimit64
+prlimit64--pidns-translation     test_pidns -e trace=prlimit64
 process_vm_readv	-s5 -a37
+process_vm_readv--pidns-translation	test_pidns -s5 -a37 -e trace=process_vm_readv
 process_vm_writev	-s5 -a38
+process_vm_writev--pidns-translation	test_pidns -s5 -a38 -e trace=process_vm_writev
 pselect6
 ptrace	-a23 -e signal=none
 ptrace_syscall_info	-a35 -e signal=none -e trace=ptrace
@@ -518,10 +535,12 @@ rmdir	-a22
 rt_sigpending	-a20
 rt_sigprocmask
 rt_sigqueueinfo	-esignal=none
+rt_sigqueueinfo--pidns-translation	test_pidns -esignal=none -e trace=rt_sigqueueinfo
 rt_sigreturn	-esignal='!USR1'
 rt_sigsuspend	-a20 -esignal=none
 rt_sigtimedwait	-a38
 rt_tgsigqueueinfo	-esignal=none
+rt_tgsigqueueinfo--pidns-translation	test_pidns -esignal=none -e trace=rt_tgsigqueueinfo
 s390_guarded_storage	-a32
 s390_guarded_storage-v	-e trace=s390_guarded_storage -a32 -v
 s390_pci_mmio_read_write	-e trace=s390_pci_mmio_read,s390_pci_mmio_write -a30
@@ -532,9 +551,13 @@ sched	test_trace_expr times -e/sched
 sched_get_priority_mxx	-a33 -e trace=sched_get_priority_min,sched_get_priority_max
 sched_rr_get_interval	-a31
 sched_xetaffinity	-a28 -e trace=sched_getaffinity,sched_setaffinity
+sched_xetaffinity--pidns-translation	test_pidns -a28 -e trace=sched_getaffinity,sched_setaffinity
 sched_xetattr	-a29 -e trace=sched_getattr,sched_setattr
+sched_xetattr--pidns-translation	test_pidns -a29 -e trace=sched_getattr,sched_setattr
 sched_xetparam	-a23 -e trace=sched_getparam,sched_setparam
+sched_xetparam--pidns-translation	test_pidns -a23 -e trace=sched_getparam,sched_setparam
 sched_xetscheduler	-a22 -e trace=sched_getscheduler,sched_setscheduler
+sched_xetscheduler--pidns-translation	test_pidns -a22 -e trace=sched_getscheduler,sched_setscheduler
 sched_yield	-a14
 seccomp-filter	-e trace=seccomp
 seccomp-filter-v	-v -e trace=seccomp
@@ -581,6 +604,7 @@ sigaction	-a31
 siginfo	-e trace=none
 signal	-a25 -e signal=none -e trace='/^signal$'
 signal_receive	-a16 -e trace=kill
+signal_receive--pidns-translation	test_pidns -a16 -e trace=kill
 signalfd4
 sigpending	-a15
 sigprocmask	-a34
@@ -592,6 +616,7 @@ so_peercred	-e trace=getsockopt
 so_peercred-Xabbrev	-e trace=getsockopt -Xabbrev
 so_peercred-Xraw	-e trace=getsockopt -Xraw -a39
 so_peercred-Xverbose	-e trace=getsockopt -Xverbose
+so_peercred--pidns-translation	test_pidns -e trace=getsockopt
 sock_filter-v	-v -e trace=getsockopt,setsockopt
 sock_filter-v-Xabbrev	-v -e trace=getsockopt,setsockopt -X abbrev
 sock_filter-v-Xraw	-a 37 -v -e trace=getsockopt,setsockopt -X raw
@@ -721,7 +746,10 @@ waitpid	-a28
 xattr	-a22 -e trace=getxattr,fgetxattr,lgetxattr,setxattr,fsetxattr,lsetxattr,listxattr,flistxattr,llistxattr,removexattr,fremovexattr,lremovexattr
 xattr-strings	-a22 -s 4 -e trace=fsetxattr
 xet_robust_list	-a24 -e trace=get_robust_list,set_robust_list
+xet_robust_list--pidns-translation	test_pidns -a24 -e trace=get_robust_list,set_robust_list
 xetitimer	-a29 -e trace=setitimer,getitimer
 xetpgid	-a11 -e trace=getpgid,setpgid
-xetpriority	-a29 -e trace=getpriority,setpriority
+xetpgid--pidns-translation	test_pidns -a11 -e trace=getpgid,setpgid
+xetpriority	-a27 -e trace=getpriority,setpriority
+xetpriority--pidns-translation	test_pidns -a27 -e trace=getpriority,setpriority
 xettimeofday	-a20 -e trace=gettimeofday,settimeofday
diff --git a/tests/getpgrp--pidns-translation.c b/tests/getpgrp--pidns-translation.c
new file mode 100644
index 00000000..de8ceb33
--- /dev/null
+++ b/tests/getpgrp--pidns-translation.c
@@ -0,0 +1,2 @@
+#define PIDNS_TRANSLATION
+#include "getpgrp.c"
diff --git a/tests/getpgrp.c b/tests/getpgrp.c
index 104f4811..3f0b9dd1 100644
--- a/tests/getpgrp.c
+++ b/tests/getpgrp.c
@@ -7,6 +7,7 @@
 
 #include "tests.h"
 #include "scno.h"
+#include "pidns.h"
 
 #ifdef __NR_getpgrp
 
@@ -16,8 +17,13 @@
 int
 main(void)
 {
-	printf("getpgrp() = %ld\n", syscall(__NR_getpgrp));
+	PIDNS_TEST_INIT;
 
+	pidns_print_leader();
+	printf("getpgrp() = %d%s\n", (int) syscall(__NR_getpgrp),
+		pidns_pid2str(PT_PGID));
+
+	pidns_print_leader();
 	puts("+++ exited with 0 +++");
 	return 0;
 }
diff --git a/tests/getpid--pidns-translation.c b/tests/getpid--pidns-translation.c
new file mode 100644
index 00000000..94b12a1a
--- /dev/null
+++ b/tests/getpid--pidns-translation.c
@@ -0,0 +1,2 @@
+#define PIDNS_TRANSLATION
+#include "getpid.c"
diff --git a/tests/getpid.c b/tests/getpid.c
index 988f19d5..7ec4e6e8 100644
--- a/tests/getpid.c
+++ b/tests/getpid.c
@@ -7,6 +7,7 @@
 
 #include "tests.h"
 #include "scno.h"
+#include "pidns.h"
 
 #if defined __NR_getpid && (!defined __NR_getxpid || __NR_getxpid != __NR_getpid)
 
@@ -16,7 +17,12 @@
 int
 main(void)
 {
-	printf("getpid() = %ld\n", syscall(__NR_getpid));
+	PIDNS_TEST_INIT;
+
+	pidns_print_leader();
+	printf("getpid() = %d%s\n", (int) syscall(__NR_getpid),
+		pidns_pid2str(PT_TGID));
+	pidns_print_leader();
 	puts("+++ exited with 0 +++");
 	return 0;
 }
diff --git a/tests/getsid--pidns-translation.c b/tests/getsid--pidns-translation.c
new file mode 100644
index 00000000..7f983e87
--- /dev/null
+++ b/tests/getsid--pidns-translation.c
@@ -0,0 +1,2 @@
+#define PIDNS_TRANSLATION
+#include "getsid.c"
diff --git a/tests/getsid.c b/tests/getsid.c
index 588ea4ab..3bf74734 100644
--- a/tests/getsid.c
+++ b/tests/getsid.c
@@ -6,15 +6,22 @@
  */
 
 #include "tests.h"
+#include "pidns.h"
+
 #include <stdio.h>
 #include <unistd.h>
 
 int
 main(void)
 {
+	PIDNS_TEST_INIT;
+
 	pid_t pid = getpid();
-	printf("getsid(%d) = %d\n", pid, getsid(pid));
+	pidns_print_leader();
+	printf("getsid(%d%s) = %d%s\n", pid, pidns_pid2str(PT_TGID),
+		getsid(pid), pidns_pid2str(PT_SID));
 
+	pidns_print_leader();
 	puts("+++ exited with 0 +++");
 	return 0;
 }
diff --git a/tests/gettid--pidns-translation.c b/tests/gettid--pidns-translation.c
new file mode 100644
index 00000000..500c3213
--- /dev/null
+++ b/tests/gettid--pidns-translation.c
@@ -0,0 +1,2 @@
+#define PIDNS_TRANSLATION
+#include "gettid.c"
diff --git a/tests/gettid.c b/tests/gettid.c
index d38918dd..314d9c2c 100644
--- a/tests/gettid.c
+++ b/tests/gettid.c
@@ -9,11 +9,17 @@
 #include <stdio.h>
 #include <unistd.h>
 #include "scno.h"
+#include "pidns.h"
 
 int
 main(void)
 {
-	printf("gettid() = %ld\n", syscall(__NR_gettid));
+	PIDNS_TEST_INIT;
+
+	pidns_print_leader();
+	printf("gettid() = %d%s\n", (int) syscall(__NR_gettid),
+		pidns_pid2str(PT_TID));
+	pidns_print_leader();
 	puts("+++ exited with 0 +++");
 	return 0;
 }
diff --git a/tests/ioctl_block--pidns-translation.c b/tests/ioctl_block--pidns-translation.c
new file mode 100644
index 00000000..5eed6076
--- /dev/null
+++ b/tests/ioctl_block--pidns-translation.c
@@ -0,0 +1,2 @@
+#define PIDNS_TRANSLATION
+#include "ioctl_block.c"
diff --git a/tests/ioctl_block--pidns-translation.test b/tests/ioctl_block--pidns-translation.test
new file mode 100755
index 00000000..bb45f695
--- /dev/null
+++ b/tests/ioctl_block--pidns-translation.test
@@ -0,0 +1,24 @@
+#!/bin/sh
+#
+# Check ioctl syscall decoding.
+#
+# Copyright (c) 2020 The strace developers.
+# All rights reserved.
+#
+# SPDX-License-Identifier: LGPL-2.1-or-later
+
+. "${srcdir=.}/init.sh"
+
+require_min_kernel_version_or_skip 4.9
+
+check_prog head
+check_prog tail
+check_prog cut
+check_prog grep
+
+run_prog > /dev/null
+run_strace --pidns-translation -f -a16 -e trace=ioctl $@ $args > "$EXP"
+parent_pid="$(tail -n 2 $LOG | head -n 1 | cut -d' ' -f1)"
+init_pid="$(tail -n 1 $LOG | cut -d' ' -f1)"
+grep -E -v "^($parent_pid|$init_pid) |ioctl\([0123][,<]" "$LOG" > "$OUT"
+match_diff "$OUT" "$EXP"
diff --git a/tests/ioctl_block.c b/tests/ioctl_block.c
index 0afe27f7..8a345f4e 100644
--- a/tests/ioctl_block.c
+++ b/tests/ioctl_block.c
@@ -9,7 +9,9 @@
  */
 
 #include "tests.h"
+#include "pidns.h"
 #include <errno.h>
+#include <unistd.h>
 #include <inttypes.h>
 #include <stdio.h>
 #include <string.h>
@@ -41,12 +43,15 @@ static struct xlat_data block_argless[] = {
 #define TEST_NULL_ARG(cmd)						\
 	do {								\
 		ioctl(-1, cmd, 0);					\
+		pidns_print_leader();					\
 		printf("ioctl(-1, %s, NULL) = -1 EBADF (%m)\n", #cmd);	\
 	} while (0)
 
 int
 main(void)
 {
+	PIDNS_TEST_INIT;
+
 	TEST_NULL_ARG(BLKBSZGET);
 	TEST_NULL_ARG(BLKBSZSET);
 	TEST_NULL_ARG(BLKFRAGET);
@@ -91,18 +96,22 @@ main(void)
 #endif
 
 	ioctl(-1, BLKRASET, lmagic);
+	pidns_print_leader();
 	printf("ioctl(-1, BLKRASET, %lu) = -1 EBADF (%m)\n", lmagic);
 
 	ioctl(-1, BLKFRASET, lmagic);
+	pidns_print_leader();
 	printf("ioctl(-1, BLKFRASET, %lu) = -1 EBADF (%m)\n", lmagic);
 
 	TAIL_ALLOC_OBJECT_CONST_PTR(int, val_int);
 	*val_int = magic;
 
 	ioctl(-1, BLKROSET, val_int);
+	pidns_print_leader();
 	printf("ioctl(-1, BLKROSET, [%d]) = -1 EBADF (%m)\n", *val_int);
 
 	ioctl(-1, BLKBSZSET, val_int);
+	pidns_print_leader();
 	printf("ioctl(-1, BLKBSZSET, [%d]) = -1 EBADF (%m)\n", *val_int);
 
 	uint64_t *pair_int64 = tail_alloc(sizeof(*pair_int64) * 2);
@@ -111,18 +120,21 @@ main(void)
 
 #ifdef BLKDISCARD
 	ioctl(-1, BLKDISCARD, pair_int64);
+	pidns_print_leader();
 	printf("ioctl(-1, BLKDISCARD, [%" PRIu64 ", %" PRIu64 "])"
 	       " = -1 EBADF (%m)\n", pair_int64[0], pair_int64[1]);
 #endif
 
 #ifdef BLKSECDISCARD
 	ioctl(-1, BLKSECDISCARD, pair_int64);
+	pidns_print_leader();
 	printf("ioctl(-1, BLKSECDISCARD, [%" PRIu64 ", %" PRIu64 "])"
 	       " = -1 EBADF (%m)\n", pair_int64[0], pair_int64[1]);
 #endif
 
 #ifdef BLKZEROOUT
 	ioctl(-1, BLKZEROOUT, pair_int64);
+	pidns_print_leader();
 	printf("ioctl(-1, BLKZEROOUT, [%" PRIu64 ", %" PRIu64 "])"
 	       " = -1 EBADF (%m)\n", pair_int64[0], pair_int64[1]);
 #endif
@@ -134,6 +146,7 @@ main(void)
 	blkpg->data = (void *) (unsigned long) 0xcafef00dfffffeedULL;
 
 	ioctl(-1, BLKPG, blkpg);
+	pidns_print_leader();
 	printf("ioctl(-1, BLKPG, {op=%s, flags=%d, datalen=%d"
 	       ", data=%#lx}) = -1 EBADF (%m)\n",
 	       "BLKPG_RESIZE_PARTITION", blkpg->flags, blkpg->datalen,
@@ -149,6 +162,7 @@ main(void)
 	blkpg->data = bp;
 
 	ioctl(-1, BLKPG, blkpg);
+	pidns_print_leader();
 	printf("ioctl(-1, BLKPG, {op=%s, flags=%d, datalen=%d"
 	       ", data={start=%lld, length=%lld, pno=%d"
 	       ", devname=\"%.*s\"..., volname=\"%.*s\"...}})"
@@ -162,25 +176,31 @@ main(void)
 #if defined BLKTRACESETUP && defined HAVE_STRUCT_BLK_USER_TRACE_SETUP
 	TAIL_ALLOC_OBJECT_CONST_PTR(struct blk_user_trace_setup, buts);
 	fill_memory(buts, sizeof(*buts));
+	buts->pid = getpid();
 
 	ioctl(-1, BLKTRACESETUP, buts);
+	pidns_print_leader();
 	printf("ioctl(-1, BLKTRACESETUP, {act_mask=%hu, buf_size=%u, buf_nr=%u"
-	       ", start_lba=%" PRI__u64 ", end_lba=%" PRI__u64 ", pid=%d})"
+	       ", start_lba=%" PRI__u64 ", end_lba=%" PRI__u64 ", pid=%d%s})"
 	       " = -1 EBADF (%m)\n",
 	       buts->act_mask, buts->buf_size, buts->buf_nr,
-	       buts->start_lba, buts->end_lba, buts->pid);
+	       buts->start_lba, buts->end_lba, buts->pid,
+	       pidns_pid2str(PT_TGID));
 #endif
 
 	unsigned int i;
 	for (i = 0; i < ARRAY_SIZE(block_argless); ++i) {
 		ioctl(-1, (unsigned long) block_argless[i].val, lmagic);
+		pidns_print_leader();
 		printf("ioctl(-1, %s) = -1 EBADF (%m)\n", block_argless[i].str);
 	}
 
 	ioctl(-1, _IOC(_IOC_READ, 0x12, 0xfe, 0xff), lmagic);
+	pidns_print_leader();
 	printf("ioctl(-1, %s, %#lx) = -1 EBADF (%m)\n",
 	       "_IOC(_IOC_READ, 0x12, 0xfe, 0xff)", lmagic);
 
+	pidns_print_leader();
 	puts("+++ exited with 0 +++");
 	return 0;
 }
diff --git a/tests/ioprio--pidns-translation.c b/tests/ioprio--pidns-translation.c
new file mode 100644
index 00000000..bcb49a8b
--- /dev/null
+++ b/tests/ioprio--pidns-translation.c
@@ -0,0 +1,2 @@
+#define PIDNS_TRANSLATION
+#include "ioprio.c"
diff --git a/tests/ioprio.c b/tests/ioprio.c
index 5e1e1194..110df063 100644
--- a/tests/ioprio.c
+++ b/tests/ioprio.c
@@ -9,8 +9,8 @@
  */
 
 #include "tests.h"
-
 #include "scno.h"
+#include "pidns.h"
 
 #if defined(__NR_ioprio_get) && defined(__NR_ioprio_set)
 
@@ -30,12 +30,18 @@ enum {
 int
 main(void)
 {
+	PIDNS_TEST_INIT;
+
 	static const kernel_ulong_t bogus_which =
 		(kernel_ulong_t) 0xdeadfacefa57beefULL;
 	static const kernel_ulong_t bogus_who =
 		(kernel_ulong_t) 0xbadc0dedda7a1057ULL;
 	static const kernel_ulong_t bogus_ioprio =
 		(kernel_ulong_t) 0xdec0ded1facefeedULL;
+
+	const int pid = getpid();
+	const int pgid = getpgid(0);
+
 # if !XLAT_RAW
 	static const char * const bogus_ioprio_str =
 		"IOPRIO_PRIO_VALUE(0x7d677 /* IOPRIO_CLASS_??? */, 7917)";
@@ -46,6 +52,7 @@ main(void)
 
 	rc = syscall(__NR_ioprio_get, bogus_which, bogus_who);
 	errstr = sprintrc(rc);
+	pidns_print_leader();
 # if XLAT_RAW
 	printf("ioprio_get(%#x, %d) = %s\n",
 	       (int) bogus_which, (int) bogus_who, errstr);
@@ -54,42 +61,52 @@ main(void)
 	       (int) bogus_which, (int) bogus_who, errstr);
 # endif
 
-	rc = syscall(__NR_ioprio_get, 1, 0);
+	rc = syscall(__NR_ioprio_get, 1, pid);
 	errstr = sprintrc(rc);
+	pidns_print_leader();
+	printf("ioprio_get(");
 # if XLAT_RAW
-	printf("ioprio_get(0x1, 0) = %s\n", errstr);
+	printf("0x1, ");
+# elif XLAT_VERBOSE
+	printf("0x1 /* IOPRIO_WHO_PROCESS */, ");
 # else /* XLAT_ABBREV */
-#  if XLAT_VERBOSE
-	printf("ioprio_get(0x1 /* IOPRIO_WHO_PROCESS */, 0) = %s", errstr);
-#  else
-	printf("ioprio_get(IOPRIO_WHO_PROCESS, 0) = %s", errstr);
-#  endif
+	printf("IOPRIO_WHO_PROCESS, ");
+# endif
+	printf("%d%s) = %s", pid, pidns_pid2str(PT_TGID), errstr);
+# if !XLAT_RAW
 	if (rc >= 0) {
 		printf(" (IOPRIO_PRIO_VALUE(");
 		printxval(ioprio_class, (unsigned int) rc >> 13,
 			  "IOPRIO_CLASS_???");
 		printf(", %u))", (unsigned int) rc & 0x1fff);
 	}
-	puts("");
 # endif
+	puts("");
 
-	rc = syscall(__NR_ioprio_set, 2, 0, 8191);
+	rc = syscall(__NR_ioprio_set, 2, pgid, 8191);
 	errstr = sprintrc(rc);
+	pidns_print_leader();
+	printf("ioprio_set(");
 # if XLAT_RAW
-	printf("ioprio_set(%#x, 0, 8191) = %s\n", 2, errstr);
+	printf("%#x", 2);
 # elif XLAT_VERBOSE
-	printf("ioprio_set(%#x /* IOPRIO_WHO_PGRP */, 0, 8191"
-	       " /* IOPRIO_PRIO_VALUE(0 /* IOPRIO_CLASS_NONE */, 8191) */)"
-	       " = %s\n",
-	       2, errstr);
+	printf("%#x /* IOPRIO_WHO_PGRP */", 2);
 # else /* XLAT_ABBREV */
-	printf("ioprio_set(IOPRIO_WHO_PGRP, 0"
-	       ", IOPRIO_PRIO_VALUE(IOPRIO_CLASS_NONE, 8191)) = %s\n",
-	       errstr);
+	printf("IOPRIO_WHO_PGRP");
+# endif
+	printf(", %d%s", pgid, pidns_pid2str(PT_PGID));
+# if XLAT_RAW
+	printf(", 8191)");
+# elif XLAT_VERBOSE
+	printf(", 8191 /* IOPRIO_PRIO_VALUE(0 /* IOPRIO_CLASS_NONE */, 8191) */)");
+# else /* XLAT_ABBREV */
+	printf(", IOPRIO_PRIO_VALUE(IOPRIO_CLASS_NONE, 8191))");
 # endif
+	printf(" = %s\n", errstr);
 
 	rc = syscall(__NR_ioprio_set, bogus_which, bogus_who, bogus_ioprio);
 	errstr = sprintrc(rc);
+	pidns_print_leader();
 # if XLAT_RAW
 	printf("ioprio_set(%#x, %d, %d) = %s\n",
 	       (int) bogus_which, (int) bogus_who, (int) bogus_ioprio,
@@ -104,6 +121,7 @@ main(void)
 	       errstr);
 # endif
 
+	pidns_print_leader();
 	puts("+++ exited with 0 +++");
 
 	return 0;
diff --git a/tests/kcmp-y--pidns-translation.c b/tests/kcmp-y--pidns-translation.c
new file mode 100644
index 00000000..f54d94cc
--- /dev/null
+++ b/tests/kcmp-y--pidns-translation.c
@@ -0,0 +1,2 @@
+#define PIDNS_TRANSLATION
+#include "kcmp-y.c"
diff --git a/tests/kcmp.c b/tests/kcmp.c
index dc5ba9a4..ce705ad0 100644
--- a/tests/kcmp.c
+++ b/tests/kcmp.c
@@ -9,8 +9,8 @@
  */
 
 #include "tests.h"
-
 #include "scno.h"
+#include "pidns.h"
 
 #ifdef __NR_kcmp
 
@@ -101,7 +101,11 @@ do_kcmp(kernel_ulong_t pid1, kernel_ulong_t pid2, kernel_ulong_t type,
 	rc = syscall(__NR_kcmp, pid1, pid2, type, idx1, idx2);
 	errstr = sprintrc(rc);
 
-	printf("kcmp(%d, %d, ", (int) pid1, (int) pid2);
+	const char *pid_str = pidns_pid2str(PT_TGID);
+	pidns_print_leader();
+	printf("kcmp(%d%s, %d%s, ",
+		(int) pid1, (int) pid1 == getpid() ? pid_str : "",
+		(int) pid2, (int) pid2 == getpid() ? pid_str : "");
 
 	if (type_str)
 		printf("%s", type_str);
@@ -146,6 +150,8 @@ do_kcmp(kernel_ulong_t pid1, kernel_ulong_t pid2, kernel_ulong_t type,
 int
 main(void)
 {
+	PIDNS_TEST_INIT;
+
 	static const kernel_ulong_t bogus_pid1 =
 		(kernel_ulong_t) 0xdeadca75face1057ULL;
 	static const kernel_ulong_t bogus_pid2 =
@@ -221,6 +227,7 @@ main(void)
 			(uintptr_t) slot, 1);
 	}
 
+	pidns_print_leader();
 	puts("+++ exited with 0 +++");
 
 	return 0;
diff --git a/tests/kill--pidns-translation.c b/tests/kill--pidns-translation.c
new file mode 100644
index 00000000..4736ca14
--- /dev/null
+++ b/tests/kill--pidns-translation.c
@@ -0,0 +1,2 @@
+#define PIDNS_TRANSLATION
+#include "kill.c"
diff --git a/tests/kill.c b/tests/kill.c
index f7d9341e..17de35da 100644
--- a/tests/kill.c
+++ b/tests/kill.c
@@ -11,6 +11,7 @@
 
 #include "tests.h"
 #include "scno.h"
+#include "pidns.h"
 
 #ifdef __NR_kill
 
@@ -26,6 +27,8 @@ handler(int sig)
 int
 main(void)
 {
+	PIDNS_TEST_INIT;
+
 	const struct sigaction act = { .sa_handler = handler };
 	if (sigaction(SIGALRM, &act, NULL))
 		perror_msg_and_fail("sigaction");
@@ -37,18 +40,23 @@ main(void)
 		perror_msg_and_fail("sigprocmask");
 
 	const int pid = getpid();
+	const char *pid_str = pidns_pid2str(PT_TGID);
 	long rc = syscall(__NR_kill, pid, (long) 0xdefaced00000000ULL | SIGALRM);
-	printf("kill(%d, SIGALRM) = %ld\n", pid, rc);
+	pidns_print_leader();
+	printf("kill(%d%s, SIGALRM) = %ld\n", pid, pid_str, rc);
 
 	const long big_pid = (long) 0xfacefeedbadc0dedULL;
 	const long big_sig = (long) 0xdeadbeefcafef00dULL;
 	rc = syscall(__NR_kill, big_pid, big_sig);
+	pidns_print_leader();
 	printf("kill(%d, %d) = %ld %s (%m)\n",
 	       (int) big_pid, (int) big_sig, rc, errno2name());
 
 	rc = syscall(__NR_kill, (long) 0xdefaced00000000ULL | pid, 0);
-	printf("kill(%d, 0) = %ld\n", pid, rc);
+	pidns_print_leader();
+	printf("kill(%d%s, 0) = %ld\n", pid, pid_str, rc);
 
+	pidns_print_leader();
 	puts("+++ exited with 0 +++");
 	return 0;
 }
diff --git a/tests/migrate_pages--pidns-translation.c b/tests/migrate_pages--pidns-translation.c
new file mode 100644
index 00000000..ec34938d
--- /dev/null
+++ b/tests/migrate_pages--pidns-translation.c
@@ -0,0 +1,2 @@
+#define PIDNS_TRANSLATION
+#include "migrate_pages.c"
diff --git a/tests/migrate_pages.c b/tests/migrate_pages.c
index 2dfba49c..390b490b 100644
--- a/tests/migrate_pages.c
+++ b/tests/migrate_pages.c
@@ -10,6 +10,7 @@
 
 #include "tests.h"
 #include "scno.h"
+#include "pidns.h"
 
 #ifdef __NR_migrate_pages
 
@@ -19,11 +20,21 @@
 int
 main(void)
 {
-	const long pid = (long) 0xfacefeedffffffffULL;
+	PIDNS_TEST_INIT;
+
+	const long pid = (long) 0xfacefeed00000000ULL | getpid();
 	long rc = syscall(__NR_migrate_pages, pid, 0, 0, 0);
-	printf("migrate_pages(%d, 0, NULL, NULL) = %ld %s (%m)\n",
-	       (int) pid, rc, errno2name());
 
+	pidns_print_leader();
+	printf("migrate_pages(%d%s, 0, NULL, NULL) = %ld",
+		(int) pid, pidns_pid2str(PT_TGID), rc);
+
+	if (rc < 0)
+		printf(" %s (%m)\n", errno2name());
+	else
+		printf("\n");
+
+	pidns_print_leader();
 	puts("+++ exited with 0 +++");
 	return 0;
 }
diff --git a/tests/move_pages--pidns-translation.c b/tests/move_pages--pidns-translation.c
new file mode 100644
index 00000000..8498e399
--- /dev/null
+++ b/tests/move_pages--pidns-translation.c
@@ -0,0 +1,2 @@
+#define PIDNS_TRANSLATION
+#include "move_pages.c"
diff --git a/tests/move_pages.c b/tests/move_pages.c
index e00fd1ac..56843158 100644
--- a/tests/move_pages.c
+++ b/tests/move_pages.c
@@ -10,6 +10,7 @@
 
 #include "tests.h"
 #include "scno.h"
+#include "pidns.h"
 
 #ifdef __NR_move_pages
 
@@ -122,15 +123,20 @@ print_status_array(const int *const status, const unsigned long count)
 }
 
 static void
-print_stat_pages(const unsigned long pid, const unsigned long count,
-		 const void **const pages, int *const status)
+print_stat_pages(const unsigned long pid,
+		 const char *pid_str,
+		 const unsigned long count,
+		 const void **const pages,
+		 int *const status)
 {
 	const unsigned long flags = (unsigned long) 0xfacefeed00000002ULL;
 
 	long rc = syscall(__NR_move_pages,
 			  pid, count, pages, NULL, status, flags);
 	const char *errstr = sprintrc(rc);
-	printf("move_pages(%d, %lu, ", (int) pid, count);
+	pidns_print_leader();
+	printf("move_pages(%d%s, %lu, ", (int) pid, pid_str,
+		count);
 	print_page_array(pages, count, 0);
 	printf(", NULL, ");
 	if (rc) {
@@ -152,6 +158,7 @@ print_stat_pages(const unsigned long pid, const unsigned long count,
 
 static void
 print_move_pages(const unsigned long pid,
+		 const char *pid_str,
 		 unsigned long count,
 		 const unsigned int offset,
 		 const void **const pages,
@@ -164,7 +171,9 @@ print_move_pages(const unsigned long pid,
 	long rc = syscall(__NR_move_pages,
 			  pid, count, pages, nodes, status, flags);
 	const char *errstr = sprintrc(rc);
-	printf("move_pages(%d, %lu, ", (int) pid, count);
+	pidns_print_leader();
+	printf("move_pages(%d%s, %lu, ", (int) pid, pid_str,
+		count);
 	print_page_array(pages, count, offset);
 	printf(", ");
 	print_node_array(nodes, count, offset);
@@ -185,8 +194,11 @@ print_move_pages(const unsigned long pid,
 int
 main(void)
 {
+	PIDNS_TEST_INIT;
+
 	const unsigned long pid =
 		(unsigned long) 0xfacefeed00000000ULL | getpid();
+	const char *pid_str = pidns_pid2str(PT_TGID);
 	unsigned long count = 1;
 	const unsigned page_size = get_page_size();
 	const void *const page = tail_alloc(page_size);
@@ -195,40 +207,41 @@ main(void)
 	TAIL_ALLOC_OBJECT_VAR_PTR(int, nodes);
 	TAIL_ALLOC_OBJECT_VAR_PTR(int, status);
 
-	print_stat_pages(pid, 0, pages, status);
-	print_move_pages(pid, 0, 0, pages, nodes, status);
-	print_move_pages(pid, 0, 1, pages + 1, nodes + 1, status + 1);
+	print_stat_pages(pid, pid_str, 0, pages, status);
+	print_move_pages(pid, pid_str, 0, 0, pages, nodes, status);
+	print_move_pages(pid, pid_str, 0, 1, pages + 1, nodes + 1, status + 1);
 
 	*pages = page;
-	print_stat_pages(pid, count, pages, status);
+	print_stat_pages(pid, pid_str, count, pages, status);
 	*nodes = 0xdeadbee1;
-	print_move_pages(pid, count, 0, pages, nodes, status);
-	print_move_pages(pid, count, 1, pages, nodes, status);
+	print_move_pages(pid, pid_str, count, 0, pages, nodes, status);
+	print_move_pages(pid, pid_str, count, 1, pages, nodes, status);
 
 	++count;
 	--status;
 	*(--pages) = efault;
-	print_stat_pages(pid, count, pages, status);
+	print_stat_pages(pid, pid_str, count, pages, status);
 	*(--nodes) = 0xdeadbee2;
-	print_move_pages(pid, count, 0, pages, nodes, status);
-	print_move_pages(pid, count, 1, pages, nodes, status);
+	print_move_pages(pid, pid_str, count, 0, pages, nodes, status);
+	print_move_pages(pid, pid_str, count, 1, pages, nodes, status);
 
 	++count;
 	--status;
 	*(--pages) = nodes;
-	print_stat_pages(pid, count, pages, status);
+	print_stat_pages(pid, pid_str, count, pages, status);
 	*(--nodes) = 0xdeadbee3;
-	print_move_pages(pid, count, 0, pages, nodes, status);
-	print_move_pages(pid, count, 1, pages, nodes, status);
+	print_move_pages(pid, pid_str, count, 0, pages, nodes, status);
+	print_move_pages(pid, pid_str, count, 1, pages, nodes, status);
 
 	++count;
 	--status;
 	*(--pages) = status;
-	print_stat_pages(pid, count, pages, status);
+	print_stat_pages(pid, pid_str, count, pages, status);
 	*(--nodes) = 0xdeadbee4;
-	print_move_pages(pid, count, 0, pages, nodes, status);
-	print_move_pages(pid, count, 1, pages, nodes, status);
+	print_move_pages(pid, pid_str, count, 0, pages, nodes, status);
+	print_move_pages(pid, pid_str, count, 1, pages, nodes, status);
 
+	pidns_print_leader();
 	puts("+++ exited with 0 +++");
 	return 0;
 }
diff --git a/tests/net-sockaddr--pidns-translation.c b/tests/net-sockaddr--pidns-translation.c
new file mode 100644
index 00000000..ff432bf4
--- /dev/null
+++ b/tests/net-sockaddr--pidns-translation.c
@@ -0,0 +1,2 @@
+#define PIDNS_TRANSLATION
+#include "net-sockaddr.c"
diff --git a/tests/net-sockaddr.c b/tests/net-sockaddr.c
index 4fc9da6e..b9cd46fd 100644
--- a/tests/net-sockaddr.c
+++ b/tests/net-sockaddr.c
@@ -9,6 +9,7 @@
  */
 
 #include "tests.h"
+#include "pidns.h"
 #include <stddef.h>
 #include <stdio.h>
 #include <string.h>
@@ -40,18 +41,21 @@ check_un(void)
 	memset(un->sun_path, '0', sizeof(un->sun_path));
 	unsigned int len = sizeof(*un);
 	int ret = connect(-1, (void *) un, len);
+	pidns_print_leader();
 	printf("connect(-1, {sa_family=AF_UNIX, sun_path=\"%.*u\"}"
 	       ", %u) = %d EBADF (%m)\n",
 	       (int) sizeof(un->sun_path), 0, len, ret);
 
 	un->sun_path[1] = 0;
 	ret = connect(-1, (void *) un, len);
+	pidns_print_leader();
 	printf("connect(-1, {sa_family=AF_UNIX, sun_path=\"%u\"}, %u)"
 	       " = %d EBADF (%m)\n", 0, len, ret);
 
 	un->sun_path[0] = 0;
 	un->sun_path[2] = 1;
 	ret = connect(-1, (void *) un, len);
+	pidns_print_leader();
 	printf("connect(-1, {sa_family=AF_UNIX, sun_path=@\"\\0\\001%.*u\"}"
 	       ", %u) = %d EBADF (%m)\n",
 	       (int) sizeof(un->sun_path) - 3, 0, len, ret);
@@ -61,12 +65,14 @@ check_un(void)
 	memset(un->sun_path, '0', sizeof(un->sun_path));
 	len = sizeof(*un) + 2;
 	ret = connect(-1, (void *) un, len);
+	pidns_print_leader();
 	printf("connect(-1, {sa_family=AF_UNIX, sun_path=\"%.*u\"}"
 	       ", %u) = %d EBADF (%m)\n",
 	       (int) sizeof(un->sun_path), 0, len, ret);
 
 	un->sun_path[0] = 0;
 	ret = connect(-1, (void *) un, len);
+	pidns_print_leader();
 	printf("connect(-1, {sa_family=AF_UNIX, sun_path=@\"%.*u\"}"
 	       ", %u) = %d EBADF (%m)\n",
 	       (int) sizeof(un->sun_path) - 1, 0, len, ret);
@@ -75,18 +81,21 @@ check_un(void)
 	un->sun_family = AF_UNIX;
 	len = sizeof(*un) - 2;
 	ret = connect(-1, (void *) un, len);
+	pidns_print_leader();
 	printf("connect(-1, {sa_family=AF_UNIX, sun_path=\"%.*u\"}"
 	       ", %u) = %d EBADF (%m)\n",
 	       (int) sizeof(un->sun_path) - 2, 0, len, ret);
 
 	un->sun_path[0] = 0;
 	ret = connect(-1, (void *) un, len);
+	pidns_print_leader();
 	printf("connect(-1, {sa_family=AF_UNIX, sun_path=@\"%.*u\"}"
 	       ", %u) = %d EBADF (%m)\n",
 	       (int) sizeof(un->sun_path) - 3, 0, len, ret);
 
 	len = sizeof(*un);
 	ret = connect(-1, (void *) un, len);
+	pidns_print_leader();
 	printf("connect(-1, %p, %u) = %d EBADF (%m)\n", un, len, ret);
 
 	un = tail_alloc(sizeof(struct sockaddr_storage));
@@ -94,12 +103,14 @@ check_un(void)
 	memset(un->sun_path, '0', sizeof(un->sun_path));
 	len = sizeof(struct sockaddr_storage) + 1;
 	ret = connect(-1, (void *) un, len);
+	pidns_print_leader();
 	printf("connect(-1, {sa_family=AF_UNIX, sun_path=\"%.*u\"}"
 	       ", %u) = %d EBADF (%m)\n",
 	       (int) sizeof(un->sun_path), 0, len, ret);
 
 	un->sun_path[0] = 0;
 	ret = connect(-1, (void *) un, len);
+	pidns_print_leader();
 	printf("connect(-1, {sa_family=AF_UNIX, sun_path=@\"%.*u\"}"
 	       ", %u) = %d EBADF (%m)\n",
 	       (int) sizeof(un->sun_path) - 1, 0, len, ret);
@@ -117,6 +128,7 @@ check_in(void)
 	in->sin_addr.s_addr = inet_addr(h_addr);
 	unsigned int len = sizeof(*in);
 	int ret = connect(-1, (void *) in, len);
+	pidns_print_leader();
 	printf("connect(-1, {sa_family=AF_INET, sin_port=htons(%hu)"
 	       ", sin_addr=inet_addr(\"%s\")}, %u) = %d EBADF (%m)\n",
 	       h_port, h_addr, len, ret);
@@ -127,6 +139,7 @@ check_in(void)
 	in->sin_addr.s_addr = inet_addr(h_addr);
 	len = sizeof(*in) + 4;
 	ret = connect(-1, (void *) in, len);
+	pidns_print_leader();
 	printf("connect(-1, {sa_family=AF_INET, sin_port=htons(%hu)"
 	       ", sin_addr=inet_addr(\"%s\")}, %u) = %d EBADF (%m)\n",
 	       h_port, h_addr, len, ret);
@@ -137,6 +150,7 @@ check_in(void)
 	in->sin_addr.s_addr = 0;
 	len = sizeof(*in) - 4;
 	ret = connect(-1, (void *) in, len);
+	pidns_print_leader();
 	printf("connect(-1, {sa_family=AF_INET, sa_data=\"%s\"}, %u)"
 	       " = %d EBADF (%m)\n",
 	       "\\0\\0\\0\\0\\0\\0\\377\\377\\377\\377",
@@ -144,6 +158,7 @@ check_in(void)
 
 	len = sizeof(*in);
 	ret = connect(-1, (void *) in, len);
+	pidns_print_leader();
 	printf("connect(-1, %p, %u) = %d EBADF (%m)\n", in, len, ret);
 }
 
@@ -155,6 +170,7 @@ check_in6_linklocal(struct sockaddr_in6 *const in6, const char *const h_addr)
 	in6->sin6_scope_id = 0xfacefeed;
 	unsigned int len = sizeof(*in6);
 	int ret = connect(-1, (void *) in6, len);
+	pidns_print_leader();
 	printf("connect(-1, {sa_family=AF_INET6, sin6_port=htons(%hu)"
 	       ", sin6_flowinfo=htonl(%u)"
 	       ", inet_pton(AF_INET6, \"%s\", &sin6_addr)"
@@ -166,7 +182,8 @@ check_in6_linklocal(struct sockaddr_in6 *const in6, const char *const h_addr)
 	in6->sin6_scope_id = ifindex_lo();
 	if (in6->sin6_scope_id) {
 		ret = connect(-1, (void *) in6, len);
-		printf("connect(-1, {sa_family=AF_INET6, sin6_port=htons(%hu)"
+		pidns_print_leader();
+	printf("connect(-1, {sa_family=AF_INET6, sin6_port=htons(%hu)"
 		       ", sin6_flowinfo=htonl(%u)"
 		       ", inet_pton(AF_INET6, \"%s\", &sin6_addr)"
 		       ", sin6_scope_id=%s}, %u)"
@@ -191,6 +208,7 @@ check_in6(void)
 	in6->sin6_scope_id = 0xfacefeed;
 	unsigned int len = sizeof(*in6);
 	int ret = connect(-1, (void *) in6, len);
+	pidns_print_leader();
 	printf("connect(-1, {sa_family=AF_INET6, sin6_port=htons(%hu)"
 	       ", sin6_flowinfo=htonl(%u)"
 	       ", inet_pton(AF_INET6, \"%s\", &sin6_addr)"
@@ -209,6 +227,7 @@ check_in6(void)
 	in6->sin6_scope_id = 0xfacefeed;
 	len = sizeof(*in6) + 4;
 	ret = connect(-1, (void *) in6, len);
+	pidns_print_leader();
 	printf("connect(-1, {sa_family=AF_INET6, sin6_port=htons(%hu)"
 	       ", sin6_flowinfo=htonl(%u)"
 	       ", inet_pton(AF_INET6, \"%s\", &sin6_addr)"
@@ -223,6 +242,7 @@ check_in6(void)
 	inet_pton(AF_INET6, h_addr, &in6->sin6_addr);
 	len = sizeof(*in6) - sizeof(in6->sin6_scope_id);
 	ret = connect(-1, (void *) in6, len);
+	pidns_print_leader();
 	printf("connect(-1, {sa_family=AF_INET6, sin6_port=htons(%hu)"
 	       ", sin6_flowinfo=htonl(%u)"
 	       ", inet_pton(AF_INET6, \"%s\", &sin6_addr)}, %u)"
@@ -236,6 +256,7 @@ check_in6(void)
 	memset(&in6->sin6_addr, '0', sizeof(in6->sin6_addr) - 4);
 	len = sizeof(*in6) - sizeof(in6->sin6_scope_id) - 4;
 	ret = connect(-1, (void *) in6, len);
+	pidns_print_leader();
 	printf("connect(-1, {sa_family=AF_INET6"
 	       ", sa_data=\"\\0\\0\\0\\0\\0\\000%.*u\"}, %u)"
 	       " = %d EBADF (%m)\n",
@@ -244,6 +265,7 @@ check_in6(void)
 
 	len = sizeof(*in6) - sizeof(in6->sin6_scope_id);
 	ret = connect(-1, (void *) in6, len);
+	pidns_print_leader();
 	printf("connect(-1, %p, %u) = %d EBADF (%m)\n", in6, len, ret);
 }
 
@@ -262,6 +284,7 @@ check_ipx(void)
 	void *ipx = tail_memdup(&c_ipx, sizeof(c_ipx));
 	unsigned int len = sizeof(c_ipx);
 	int ret = connect(-1, ipx, len);
+	pidns_print_leader();
 	printf("connect(-1, {sa_family=AF_IPX, sipx_port=htons(%u)"
 	       ", sipx_network=htonl(%#x)"
 	       ", sipx_node=[%#02x, %#02x, %#02x, %#02x, %#02x, %#02x]"
@@ -316,18 +339,21 @@ check_ax25(void)
 	fill_memory(sax, size);
 	sax->fsa_ax25.sax25_family = AF_AX25;
 	rc = connect(-1, sax_void, sizeof(struct sockaddr_ax25) - 1);
+	pidns_print_leader();
 	printf("connect(-1, {sa_family=AF_AX25, sa_data=\"\\202\\203\\204\\205"
 	       "\\206\\207\\210\\211\\212\\213\\214\\215\\216\"}, %zu) = %s\n",
 	       sizeof(struct sockaddr_ax25) - 1, sprintrc(rc));
 
 	memcpy(sax, &ax25, sizeof(ax25));
 	rc = connect(-1, sax_void, sizeof(struct sockaddr_ax25));
+	pidns_print_leader();
 	printf("connect(-1, {sa_family=AF_AX25, fsa_ax25={sax25_call=VALID-13"
 	       ", sax25_ndigis=8}, fsa_digipeater=[/* ??? */]}, %zu) = %s\n",
 	       sizeof(struct sockaddr_ax25), sprintrc(rc));
 
 	sax->fsa_ax25.sax25_ndigis = 0;
 	rc = connect(-1, sax_void, sizeof(struct sockaddr_ax25));
+	pidns_print_leader();
 	printf("connect(-1, {sa_family=AF_AX25, sax25_call=VALID-13"
 	       ", sax25_ndigis=0}, %zu) = %s\n",
 	       sizeof(struct sockaddr_ax25), sprintrc(rc));
@@ -335,6 +361,7 @@ check_ax25(void)
 	sax->fsa_ax25.sax25_ndigis = 8;
 	size = sizeof(struct sockaddr_ax25) + sizeof(ax25_address) * 3 + 1;
 	rc = connect(-1, sax_void, size);
+	pidns_print_leader();
 	printf("connect(-1, {sa_family=AF_AX25, fsa_ax25={sax25_call=VALID-13"
 	       ", sax25_ndigis=8}, fsa_digipeater"
 	       "=[{ax25_call=\"\\xa6\\xa0\\x82\\x40\\x86\\x8a\\x00\""
@@ -348,6 +375,7 @@ check_ax25(void)
 	sax->fsa_digipeater[2].ax25_call[6] = 0x4;
 	size = sizeof(struct sockaddr_ax25) + sizeof(ax25_address) * 4;
 	rc = connect(-1, sax_void, size);
+	pidns_print_leader();
 	printf("connect(-1, {sa_family=AF_AX25, fsa_ax25={sax25_call=VALID-13"
 	       ", sax25_ndigis=8}, fsa_digipeater"
 	       "=[{ax25_call=\"\\xa6\\xa0\\x82\\x40\\x86\\x8a\\x00\""
@@ -365,7 +393,8 @@ check_ax25(void)
 	for (size_t i = 0; i < 3; i++) {
 		size = sizeof(ax25) + sizeof(ax25_address) * (i / 2);
 		rc = connect(-1, sax_void, size);
-		printf("connect(-1, {sa_family=AF_AX25"
+		pidns_print_leader();
+	printf("connect(-1, {sa_family=AF_AX25"
 		       ", fsa_ax25={sax25_call=VALID-13, sax25_ndigis=%d}"
 		       ", fsa_digipeater=[VALID2-7, OK-15, %s /* FINE-2 */"
 		       ", {ax25_call=\"\\xe6\\xda\\xc2\\xd8\\xd8\\xe6\\x12\""
@@ -427,13 +456,15 @@ check_x25(void)
 	long rc;
 
 	rc = connect(-1, x25_void, sizeof(c_x25) - 1);
+	pidns_print_leader();
 	printf("connect(-1, {sa_family=AF_X25"
 	       ", sa_data=\"0123456789abcde\"}, %zu) = %s\n",
 	       sizeof(c_x25) - 1, sprintrc(rc));
 
 	for (size_t i = 0; i < 2; i++) {
 		rc = connect(-1, x25_void, sizeof(c_x25) + i);
-		printf("connect(-1, {sa_family=AF_X25"
+		pidns_print_leader();
+	printf("connect(-1, {sa_family=AF_X25"
 		       ", sx25_addr={x25_addr=\"0123456789abcde\"...}"
 		       "}, %zu) = %s\n",
 		       sizeof(c_x25) + i, sprintrc(rc));
@@ -442,6 +473,7 @@ check_x25(void)
 	struct sockaddr_x25 *const x25 = x25_void;
 	x25->sx25_addr.x25_addr[10] = '\0';
 	rc = connect(-1, x25_void, sizeof(c_x25));
+	pidns_print_leader();
 	printf("connect(-1, {sa_family=AF_X25"
 	       ", sx25_addr={x25_addr=\"0123456789\"}"
 	       "}, %zu) = %s\n",
@@ -457,19 +489,21 @@ check_nl(void)
 	nl->nl_groups = 0xfacefeed;
 	unsigned int len = sizeof(*nl);
 	int ret = connect(-1, (void *) nl, len);
+	pidns_print_leader();
 	printf("connect(-1, {sa_family=AF_NETLINK, nl_pid=%d"
 	       ", nl_groups=%#08x}, %u) = %d EBADF (%m)\n",
 	       nl->nl_pid, nl->nl_groups, len, ret);
 
 	nl = ((void *) nl) - 4;
 	nl->nl_family = AF_NETLINK;
-	nl->nl_pid = 1234567890;
+	nl->nl_pid = getpid();
 	nl->nl_groups = 0xfacefeed;
 	len = sizeof(*nl) + 4;
 	ret = connect(-1, (void *) nl, len);
-	printf("connect(-1, {sa_family=AF_NETLINK, nl_pid=%d"
+	pidns_print_leader();
+	printf("connect(-1, {sa_family=AF_NETLINK, nl_pid=%d%s"
 	       ", nl_groups=%#08x}, %u) = %d EBADF (%m)\n",
-	       nl->nl_pid, nl->nl_groups, len, ret);
+	       nl->nl_pid, pidns_pid2str(PT_TGID), nl->nl_groups, len, ret);
 }
 
 static void
@@ -487,6 +521,7 @@ check_ll(void)
 	void *ll = tail_memdup(&c_ll, sizeof(c_ll));
 	unsigned int len = sizeof(c_ll);
 	int ret = connect(-1, ll, len);
+	pidns_print_leader();
 	printf("connect(-1, {sa_family=AF_PACKET"
 	       ", sll_protocol=htons(ETH_P_ALL)"
 	       ", sll_ifindex=%u, sll_hatype=ARPHRD_ETHER"
@@ -502,6 +537,7 @@ check_ll(void)
 
 	((struct sockaddr_ll *) ll)->sll_halen++;
 	ret = connect(-1, ll, len);
+	pidns_print_leader();
 	printf("connect(-1, {sa_family=AF_PACKET"
 	       ", sll_protocol=htons(ETH_P_ALL)"
 	       ", sll_ifindex=%u, sll_hatype=ARPHRD_ETHER"
@@ -517,6 +553,7 @@ check_ll(void)
 
 	((struct sockaddr_ll *) ll)->sll_halen = 0;
 	ret = connect(-1, ll, len);
+	pidns_print_leader();
 	printf("connect(-1, {sa_family=AF_PACKET"
 	       ", sll_protocol=htons(ETH_P_ALL)"
 	       ", sll_ifindex=%u, sll_hatype=ARPHRD_ETHER"
@@ -526,7 +563,8 @@ check_ll(void)
 	((struct sockaddr_ll *) ll)->sll_ifindex = ifindex_lo();
 	if (((struct sockaddr_ll *) ll)->sll_ifindex) {
 		ret = connect(-1, ll, len);
-		printf("connect(-1, {sa_family=AF_PACKET"
+	pidns_print_leader();
+	printf("connect(-1, {sa_family=AF_PACKET"
 		       ", sll_protocol=htons(ETH_P_ALL)"
 		       ", sll_ifindex=%s"
 		       ", sll_hatype=ARPHRD_ETHER"
@@ -549,11 +587,13 @@ check_hci(void)
 	unsigned int len = sizeof(*hci);
 
 	int ret = connect(-1, (void *) hci, 4);
+	pidns_print_leader();
 	printf("connect(-1, {sa_family=AF_BLUETOOTH, hci_dev=htobs(%hu)"
 	       "}, 4) = %d EBADF (%m)\n",
 	       h_port, ret);
 
 	ret = connect(-1, (void *) hci, len);
+	pidns_print_leader();
 	printf("connect(-1, {sa_family=AF_BLUETOOTH, hci_dev=htobs(%hu)"
 # ifdef HAVE_STRUCT_SOCKADDR_HCI_HCI_CHANNEL
 	       ", hci_channel=HCI_CHANNEL_RAW"
@@ -572,6 +612,7 @@ check_sco(void)
 	void *sco = tail_memdup(&c_sco, sizeof(c_sco));
 	unsigned int len = sizeof(c_sco);
 	int ret = connect(-1, sco, len);
+	pidns_print_leader();
 	printf("connect(-1, {sa_family=AF_BLUETOOTH"
 	       ", sco_bdaddr=%02x:%02x:%02x:%02x:%02x:%02x"
 	       "}, %u) = %d EBADF (%m)\n",
@@ -592,6 +633,7 @@ check_rc(void)
 	void *rc = tail_memdup(&c_rc, sizeof(c_rc));
 	unsigned int len = sizeof(c_rc);
 	int ret = connect(-1, rc, len);
+	pidns_print_leader();
 	printf("connect(-1, {sa_family=AF_BLUETOOTH"
 	       ", rc_bdaddr=%02x:%02x:%02x:%02x:%02x:%02x"
 	       ", rc_channel=%u}, %u) = %d EBADF (%m)\n",
@@ -619,6 +661,7 @@ check_l2(void)
 	unsigned int len = sizeof(c_l2);
 
 	int ret = connect(-1, l2, len);
+	pidns_print_leader();
 	printf("connect(-1, {sa_family=AF_BLUETOOTH"
 	       ", l2_psm=htobs(L2CAP_PSM_DYN_START + %hu)"
 	       ", l2_bdaddr=%02x:%02x:%02x:%02x:%02x:%02x"
@@ -640,6 +683,7 @@ check_l2(void)
 # endif
 	memcpy(l2, &c_l2, sizeof(c_l2));
 	ret = connect(-1, l2, len);
+	pidns_print_leader();
 	printf("connect(-1, {sa_family=AF_BLUETOOTH"
 	       ", l2_psm=htobs(L2CAP_PSM_SDP)"
 	       ", l2_bdaddr=%02x:%02x:%02x:%02x:%02x:%02x"
@@ -660,6 +704,7 @@ check_l2(void)
 # endif
 	memcpy(l2, &c_l2, sizeof(c_l2));
 	ret = connect(-1, l2, len);
+	pidns_print_leader();
 	printf("connect(-1, {sa_family=AF_BLUETOOTH"
 	       ", l2_psm=htobs(0xbad /* L2CAP_PSM_??? */)"
 	       ", l2_bdaddr=%02x:%02x:%02x:%02x:%02x:%02x"
@@ -677,6 +722,7 @@ check_l2(void)
 	c_l2.l2_cid = htobs(0xffff);
 	memcpy(l2, &c_l2, 12);
 	ret = connect(-1, l2, 12);
+	pidns_print_leader();
 	printf("connect(-1, {sa_family=AF_BLUETOOTH"
 	       ", l2_psm=htobs(L2CAP_PSM_AUTO_END)"
 	       ", l2_bdaddr=%02x:%02x:%02x:%02x:%02x:%02x"
@@ -700,6 +746,7 @@ check_raw(void)
 	u.sa->sa_family = 0xff;
 	unsigned int len = sizeof(*u.st) + 8;
 	int ret = connect(-1, (void *) u.st, len);
+	pidns_print_leader();
 	printf("connect(-1, {sa_family=%#x /* AF_??? */, sa_data=\"%.*u\"}"
 	       ", %u) = %d EBADF (%m)\n", u.sa->sa_family,
 	       (int) (sizeof(*u.st) - sizeof(u.sa->sa_family)), 0, len, ret);
@@ -707,11 +754,13 @@ check_raw(void)
 	u.sa->sa_family = 0;
 	len = sizeof(u.sa->sa_family) + 1;
 	ret = connect(-1, (void *) u.st, len);
+	pidns_print_leader();
 	printf("connect(-1, {sa_family=AF_UNSPEC, sa_data=\"0\"}, %u)"
 	       " = %d EBADF (%m)\n", len, ret);
 
 	u.sa->sa_family = AF_BLUETOOTH;
 	ret = connect(-1, (void *) u.st, len);
+	pidns_print_leader();
 	printf("connect(-1, {sa_family=AF_BLUETOOTH, sa_data=\"0\"}, %u)"
 	       " = %d EBADF (%m)\n", len, ret);
 }
@@ -719,6 +768,8 @@ check_raw(void)
 int
 main(void)
 {
+	PIDNS_TEST_INIT;
+
 	check_un();
 	check_in();
 	check_in6();
@@ -735,6 +786,7 @@ main(void)
 #endif
 	check_raw();
 
+	pidns_print_leader();
 	puts("+++ exited with 0 +++");
 	return 0;
 }
diff --git a/tests/netlink_audit--pidns-translation.c b/tests/netlink_audit--pidns-translation.c
new file mode 100644
index 00000000..e08f9168
--- /dev/null
+++ b/tests/netlink_audit--pidns-translation.c
@@ -0,0 +1,2 @@
+#define PIDNS_TRANSLATION
+#include "netlink_audit.c"
diff --git a/tests/netlink_audit--pidns-translation.test b/tests/netlink_audit--pidns-translation.test
new file mode 100755
index 00000000..fbc32435
--- /dev/null
+++ b/tests/netlink_audit--pidns-translation.test
@@ -0,0 +1,13 @@
+#!/bin/sh
+#
+# Check decoding of NETLINK_SOCK_DIAG protocol
+#
+# Copyright (c) 2020 The strace developers.
+# All rights reserved.
+#
+# SPDX-License-Identifier: LGPL-2.1-or-later
+
+. "${srcdir=.}/init.sh"
+
+run_prog ../netlink_netlink_diag
+test_pidns -e trace=sendto "$@"
diff --git a/tests/netlink_audit.c b/tests/netlink_audit.c
index eba609a1..5dfcd786 100644
--- a/tests/netlink_audit.c
+++ b/tests/netlink_audit.c
@@ -7,6 +7,7 @@
  */
 
 #include "tests.h"
+#include "pidns.h"
 #include <stdio.h>
 #include <string.h>
 #include <unistd.h>
@@ -17,18 +18,23 @@
 static void
 test_nlmsg_type(const int fd)
 {
+	PIDNS_TEST_INIT;
+
 	long rc;
 	struct nlmsghdr nlh = {
 		.nlmsg_len = sizeof(nlh),
 		.nlmsg_type = AUDIT_GET,
 		.nlmsg_flags = NLM_F_REQUEST,
+		.nlmsg_pid = getpid(),
 	};
 
 	rc = sendto(fd, &nlh, sizeof(nlh), MSG_DONTWAIT, NULL, 0);
+	pidns_print_leader();
 	printf("sendto(%d, {len=%u, type=AUDIT_GET"
-	       ", flags=NLM_F_REQUEST, seq=0, pid=0}"
+	       ", flags=NLM_F_REQUEST, seq=0, pid=%d%s}"
 	       ", %u, MSG_DONTWAIT, NULL, 0) = %s\n",
-	       fd, nlh.nlmsg_len, (unsigned) sizeof(nlh), sprintrc(rc));
+	       fd, nlh.nlmsg_len, nlh.nlmsg_pid, pidns_pid2str(PT_TGID),
+	       (unsigned) sizeof(nlh), sprintrc(rc));
 }
 
 int main(void)
@@ -39,6 +45,7 @@ int main(void)
 
 	test_nlmsg_type(fd);
 
+	pidns_print_leader();
 	printf("+++ exited with 0 +++\n");
 
 	return 0;
diff --git a/tests/pidfd_open--pidns-translation.c b/tests/pidfd_open--pidns-translation.c
new file mode 100644
index 00000000..c38e37a8
--- /dev/null
+++ b/tests/pidfd_open--pidns-translation.c
@@ -0,0 +1,2 @@
+#define PIDNS_TRANSLATION
+#include "pidfd_open.c"
diff --git a/tests/pidfd_open.c b/tests/pidfd_open.c
index 5860adde..e5d74a91 100644
--- a/tests/pidfd_open.c
+++ b/tests/pidfd_open.c
@@ -10,6 +10,7 @@
 
 #include "tests.h"
 #include "scno.h"
+#include "pidns.h"
 
 #ifdef __NR_pidfd_open
 
@@ -37,6 +38,8 @@ k_pidfd_open(const unsigned int pid, const unsigned int flags)
 int
 main(void)
 {
+	PIDNS_TEST_INIT;
+
 # if defined PATH_TRACING || defined PRINT_PATHS
 	skip_if_unavailable("/proc/self/fd/");
 # endif
@@ -50,16 +53,19 @@ main(void)
 
 	k_pidfd_open(0, 0);
 # ifndef PATH_TRACING
+	pidns_print_leader();
 	printf("pidfd_open(0, 0) = %s\n", errstr);
 # endif
 
 	k_pidfd_open(-1U, 0);
 # ifndef PATH_TRACING
+	pidns_print_leader();
 	printf("pidfd_open(-1, 0) = %s\n", errstr);
 # endif
 
 	k_pidfd_open(0, -1U);
 # ifndef PATH_TRACING
+	pidns_print_leader();
 	printf("pidfd_open(0, %#x) = %s\n", -1U, errstr);
 # endif
 
@@ -68,7 +74,10 @@ main(void)
 
 	k_pidfd_open(pid, flags);
 # ifndef PATH_TRACING
-	printf("pidfd_open(%d, %#x) = %s\n", pid, flags, errstr);
+	const char *pid_str = pidns_pid2str(PT_TGID);
+	pidns_print_leader();
+	printf("pidfd_open(%d%s, %#x) = %s\n",
+		pid, pid_str, flags, errstr);
 # endif
 
 # ifdef PRINT_PATHS
@@ -80,17 +89,19 @@ main(void)
 # endif
 
 # ifndef PATH_TRACING
-	printf("pidfd_open(%d, 0) = "
+	pidns_print_leader();
+	printf("pidfd_open(%d%s, 0) = "
 #  if defined PRINT_PIDFD
-	       "%ld<pid:%d>\n", pid, rc, pid
+	       "%ld<pid:%d>\n", pid, pid_str, rc, pid
 #  elif defined PRINT_PATHS
-	       "%ld<anon_inode:[pidfd]>\n", pid, rc
+	       "%ld<anon_inode:[pidfd]>\n", pid, pid_str, rc
 #  else
-	       "%s\n", pid, errstr
+	       "%s\n", pid, pid_str, errstr
 #  endif
 	       );
 # endif
 
+	pidns_print_leader();
 	puts("+++ exited with 0 +++");
 	return 0;
 }
diff --git a/tests/pidfd_send_signal--pidns-translation.c b/tests/pidfd_send_signal--pidns-translation.c
new file mode 100644
index 00000000..b04f10f5
--- /dev/null
+++ b/tests/pidfd_send_signal--pidns-translation.c
@@ -0,0 +1,2 @@
+#define PIDNS_TRANSLATION
+#include "pidfd_send_signal.c"
diff --git a/tests/pidfd_send_signal.c b/tests/pidfd_send_signal.c
index 38b5bda1..a6b2d28c 100644
--- a/tests/pidfd_send_signal.c
+++ b/tests/pidfd_send_signal.c
@@ -10,6 +10,7 @@
 #include "tests.h"
 #include <unistd.h>
 #include "scno.h"
+#include "pidns.h"
 
 #ifdef __NR_pidfd_send_signal
 
@@ -36,6 +37,8 @@ sys_pidfd_send_signal(int pidfd, int sig, const void *info, int flags)
 int
 main(void)
 {
+	PIDNS_TEST_INIT;
+
 	static const char null_path[] = "/dev/null";
 
 	int fd = open(null_path, O_RDONLY);
@@ -46,19 +49,23 @@ main(void)
 	const void *esi = (const void *) si + 1;
 
 	sys_pidfd_send_signal(fd, SIGUSR1, esi, 0);
+	pidns_print_leader();
 	printf("pidfd_send_signal(%d, SIGUSR1, %p, 0) = %s\n",
 	       fd, esi, errstr);
 
 	si->si_signo = SIGUSR1;
 	si->si_code = SI_QUEUE;
+	si->si_pid = getpid();
 
 	sys_pidfd_send_signal(fd, SIGUSR2, si, -1);
+	pidns_print_leader();
 	printf("pidfd_send_signal(%d, SIGUSR2, {si_signo=SIGUSR1"
-	       ", si_code=SI_QUEUE, si_errno=%u, si_pid=%d, si_uid=%d"
+	       ", si_code=SI_QUEUE, si_errno=%u, si_pid=%d%s, si_uid=%d"
 	       ", si_value={int=%d, ptr=%p}}, %#x) = %s\n",
-	       fd, si->si_errno, si->si_pid, si->si_uid, si->si_int, si->si_ptr,
-	       -1U, errstr);
+	       fd, si->si_errno, si->si_pid, pidns_pid2str(PT_TGID), si->si_uid,
+	       si->si_int, si->si_ptr, -1U, errstr);
 
+	pidns_print_leader();
 	puts("+++ exited with 0 +++");
 	return 0;
 }
diff --git a/tests/prlimit64--pidns-translation.c b/tests/prlimit64--pidns-translation.c
new file mode 100644
index 00000000..3972de66
--- /dev/null
+++ b/tests/prlimit64--pidns-translation.c
@@ -0,0 +1,2 @@
+#define PIDNS_TRANSLATION
+#include "prlimit64.c"
diff --git a/tests/prlimit64.c b/tests/prlimit64.c
index 34201a2b..bc1a80b3 100644
--- a/tests/prlimit64.c
+++ b/tests/prlimit64.c
@@ -19,6 +19,7 @@
 # include <sys/resource.h>
 # include <unistd.h>
 
+# include "pidns.h"
 # include "xlat.h"
 # include "xlat/resources.h"
 
@@ -42,8 +43,11 @@ sprint_rlim(uint64_t lim)
 int
 main(void)
 {
+	PIDNS_TEST_INIT;
+
 	unsigned long pid =
 		(unsigned long) 0xdefaced00000000ULL | (unsigned) getpid();
+	const char *pid_str = pidns_pid2str(PT_TGID);
 	uint64_t *const rlimit = tail_alloc(sizeof(*rlimit) * 2);
 	const struct xlat_data *xlat;
 	size_t i = 0;
@@ -54,18 +58,23 @@ main(void)
 
 		unsigned long res = 0xfacefeed00000000ULL | xlat->val;
 		long rc = syscall(__NR_prlimit64, pid, res, 0, rlimit);
+		pidns_print_leader();
 		if (rc)
-			printf("prlimit64(%d, %s, NULL, %p) = %ld %s (%m)\n",
-			       (unsigned) pid, xlat->str, rlimit,
+			printf("prlimit64(%d%s, %s, NULL, %p) ="
+				     " %ld %s (%m)\n",
+			       (unsigned) pid, pid_str,
+			       xlat->str, rlimit,
 			       rc, errno2name());
 		else
-			printf("prlimit64(%d, %s, NULL"
+			printf("prlimit64(%d%s, %s, NULL"
 			       ", {rlim_cur=%s, rlim_max=%s}) = 0\n",
-			       (unsigned) pid, xlat->str,
+			       (unsigned) pid, pid_str,
+			       xlat->str,
 			       sprint_rlim(rlimit[0]),
 			       sprint_rlim(rlimit[1]));
 	}
 
+	pidns_print_leader();
 	puts("+++ exited with 0 +++");
 	return 0;
 }
diff --git a/tests/process_vm_readv--pidns-translation.c b/tests/process_vm_readv--pidns-translation.c
new file mode 100644
index 00000000..0db29ca2
--- /dev/null
+++ b/tests/process_vm_readv--pidns-translation.c
@@ -0,0 +1,2 @@
+#define PIDNS_TRANSLATION
+#include "process_vm_readv.c"
diff --git a/tests/process_vm_readv_writev.c b/tests/process_vm_readv_writev.c
index 9309135a..44e511dd 100644
--- a/tests/process_vm_readv_writev.c
+++ b/tests/process_vm_readv_writev.c
@@ -12,6 +12,7 @@
 #include <stdio.h>
 #include <unistd.h>
 #include <sys/uio.h>
+#include "pidns.h"
 
 #if OP_WR
 # define in_iovec  rmt_iovec
@@ -121,7 +122,7 @@ print_iov(const struct iovec *iov, const void *arg_ptr, long rc)
 }
 
 static void
-do_call(kernel_ulong_t pid,
+do_call(kernel_ulong_t pid, enum pid_type pid_type,
 	kernel_ulong_t local_iov, const char *local_arg,
 	kernel_ulong_t liovcnt,
 	kernel_ulong_t remote_iov, const char *remote_arg,
@@ -135,7 +136,8 @@ do_call(kernel_ulong_t pid,
 		flags);
 	errstr = sprintrc(rc);
 
-	printf("%s(%d, ", OP_STR, (int) pid);
+	pidns_print_leader();
+	printf("%s(%d%s, ", OP_STR, (int) pid, pidns_pid2str(pid_type));
 
 	if (pr_iov)
 		pr_iov((const struct iovec *) (uintptr_t) local_iov, local_arg,
@@ -164,6 +166,8 @@ ptr_cast(void *ptr)
 int
 main(void)
 {
+	PIDNS_TEST_INIT;
+
 	enum {
 		SIZE_11 = 2,
 		SIZE_12 = 3,
@@ -243,18 +247,18 @@ main(void)
 	fill_memory_ex(data2_out, SIZE_2, SEGM2_BASE, SIZE_2);
 
 
-	do_call(bogus_pid, (kernel_ulong_t) (uintptr_t) ARG_STR(NULL),
+	do_call(bogus_pid, PT_NONE, (kernel_ulong_t) (uintptr_t) ARG_STR(NULL),
 		bogus_iovcnt1, (kernel_ulong_t) (uintptr_t) ARG_STR(NULL),
 		bogus_iovcnt2, bogus_flags, NULL);
 
-	do_call(my_pid, ptr_cast(bogus_iov + ARRAY_SIZE(bogus_iovec)),
+	do_call(my_pid, PT_TGID, ptr_cast(bogus_iov + ARRAY_SIZE(bogus_iovec)),
 		"[]", 0, ptr_cast(in_iov + ARRAY_SIZE(in_iovec)), "[]",
 		0, 0, NULL);
-	do_call(my_pid, ptr_cast(bogus_iov + ARRAY_SIZE(bogus_iovec)), NULL,
-		bogus_iovcnt1, ptr_cast(in_iov + ARRAY_SIZE(in_iovec)), NULL,
-		bogus_iovcnt2, 0, print_iov);
+	do_call(my_pid, PT_TGID, ptr_cast(bogus_iov + ARRAY_SIZE(bogus_iovec)),
+		NULL, bogus_iovcnt1, ptr_cast(in_iov + ARRAY_SIZE(in_iovec)),
+		NULL, bogus_iovcnt2, 0, print_iov);
 
-	do_call(my_pid, ptr_cast(bogus_iov), (char *) &bogus_arg,
+	do_call(my_pid, PT_TGID, ptr_cast(bogus_iov), (char *) &bogus_arg,
 		ARRAY_SIZE(bogus_iovec), ptr_cast(rmt_iov + 2),
 		(char *) &rmt_arg_cut, ARRAY_SIZE(rmt_iovec) - 2, 0, print_iov);
 
@@ -263,7 +267,7 @@ main(void)
 	lcl_arg_cut.check_rc = 1;
 #endif
 
-	do_call(my_pid, ptr_cast(lcl_iov + 2), (char *) &lcl_arg_cut,
+	do_call(my_pid, PT_TGID, ptr_cast(lcl_iov + 2), (char *) &lcl_arg_cut,
 		ARRAY_SIZE(lcl_iovec) - 1, ptr_cast(bogus_iov + 2),
 		(char *) &bogus_arg_cut, ARRAY_SIZE(bogus_iovec) - 1, 0,
 		print_iov);
@@ -273,15 +277,16 @@ main(void)
 	rmt_arg_cut.addr_term = 1;
 	rmt_arg_cut.count = 5;
 
-	do_call(my_pid, ptr_cast(lcl_iov + 2), (char *) &lcl_arg_cut,
+	do_call(my_pid, PT_TGID, ptr_cast(lcl_iov + 2), (char *) &lcl_arg_cut,
 		ARRAY_SIZE(lcl_iovec) - 2, ptr_cast(rmt_iov + 1),
 		(char *) &rmt_arg_cut, ARRAY_SIZE(rmt_iovec), 0, print_iov);
 
 	/* Correct call */
-	do_call(my_pid, ptr_cast(lcl_iov), (char *) &lcl_arg,
+	do_call(my_pid, PT_TGID, ptr_cast(lcl_iov), (char *) &lcl_arg,
 		ARRAY_SIZE(lcl_iovec), ptr_cast(rmt_iov), (char *) &rmt_arg,
 		ARRAY_SIZE(rmt_iovec), 0, print_iov);
 
+	pidns_print_leader();
 	puts("+++ exited with 0 +++");
 
 	return 0;
diff --git a/tests/process_vm_writev--pidns-translation.c b/tests/process_vm_writev--pidns-translation.c
new file mode 100644
index 00000000..9ba6a39b
--- /dev/null
+++ b/tests/process_vm_writev--pidns-translation.c
@@ -0,0 +1,2 @@
+#define PIDNS_TRANSLATION
+#include "process_vm_writev.c"
diff --git a/tests/rt_sigqueueinfo--pidns-translation.c b/tests/rt_sigqueueinfo--pidns-translation.c
new file mode 100644
index 00000000..74bfb464
--- /dev/null
+++ b/tests/rt_sigqueueinfo--pidns-translation.c
@@ -0,0 +1,2 @@
+#define PIDNS_TRANSLATION
+#include "rt_sigqueueinfo.c"
diff --git a/tests/rt_sigqueueinfo.c b/tests/rt_sigqueueinfo.c
index c1693873..e22e4640 100644
--- a/tests/rt_sigqueueinfo.c
+++ b/tests/rt_sigqueueinfo.c
@@ -7,6 +7,7 @@
  */
 
 #include "tests.h"
+#include "pidns.h"
 #include <assert.h>
 #include <stdio.h>
 #include <signal.h>
@@ -15,6 +16,8 @@
 int
 main(void)
 {
+	PIDNS_TEST_INIT;
+
 	struct sigaction sa = {
 		.sa_handler = SIG_IGN
 	};
@@ -22,15 +25,19 @@ main(void)
 		.sival_ptr = (void *) (unsigned long) 0xdeadbeefbadc0dedULL
 	};
 	pid_t pid = getpid();
+	const char *pid_str = pidns_pid2str(PT_TGID);
 
 	assert(sigaction(SIGUSR1, &sa, NULL) == 0);
 	if (sigqueue(pid, SIGUSR1, value))
 		perror_msg_and_skip("sigqueue");
-	printf("rt_sigqueueinfo(%u, SIGUSR1, {si_signo=SIGUSR1, "
-		"si_code=SI_QUEUE, si_pid=%d, si_uid=%d, "
+	pidns_print_leader();
+	printf("rt_sigqueueinfo(%d%s, SIGUSR1, {si_signo=SIGUSR1, "
+		"si_code=SI_QUEUE, si_pid=%d%s, si_uid=%u, "
 		"si_value={int=%d, ptr=%p}}) = 0\n",
-		pid, pid, getuid(), value.sival_int, value.sival_ptr);
-	printf("+++ exited with 0 +++\n");
+		pid, pid_str, pid, pid_str,
+		getuid(), value.sival_int, value.sival_ptr);
+	pidns_print_leader();
+	puts("+++ exited with 0 +++");
 
 	return 0;
 }
diff --git a/tests/rt_tgsigqueueinfo--pidns-translation.c b/tests/rt_tgsigqueueinfo--pidns-translation.c
new file mode 100644
index 00000000..94396f00
--- /dev/null
+++ b/tests/rt_tgsigqueueinfo--pidns-translation.c
@@ -0,0 +1,2 @@
+#define PIDNS_TRANSLATION
+#include "rt_tgsigqueueinfo.c"
diff --git a/tests/rt_tgsigqueueinfo.c b/tests/rt_tgsigqueueinfo.c
index 865c21f6..21d01cbb 100644
--- a/tests/rt_tgsigqueueinfo.c
+++ b/tests/rt_tgsigqueueinfo.c
@@ -10,8 +10,9 @@
 
 #include "tests.h"
 #include "scno.h"
+#include "pidns.h"
 
-#ifdef __NR_rt_tgsigqueueinfo
+#if defined __NR_rt_tgsigqueueinfo && defined __NR_gettid
 
 # include <errno.h>
 # include <signal.h>
@@ -20,11 +21,11 @@
 # include <unistd.h>
 
 static long
-k_tgsigqueueinfo(const pid_t pid, const int sig, const void *const info)
+k_tgsigqueueinfo(const pid_t tgid, const int tid, const int sig, const void *const info)
 {
 	return syscall(__NR_rt_tgsigqueueinfo,
-		       F8ILL_KULONG_MASK | pid,
-		       F8ILL_KULONG_MASK | pid,
+		       F8ILL_KULONG_MASK | tgid,
+		       F8ILL_KULONG_MASK | tid,
 		       F8ILL_KULONG_MASK | sig,
 		       info);
 }
@@ -32,6 +33,8 @@ k_tgsigqueueinfo(const pid_t pid, const int sig, const void *const info)
 int
 main(void)
 {
+	PIDNS_TEST_INIT;
+
 	const struct sigaction sa = {
 		.sa_handler = SIG_IGN
 	};
@@ -48,17 +51,22 @@ main(void)
 	info->si_value.sival_ptr =
 		(void *) (unsigned long) 0xdeadbeeffacefeedULL;
 
-	if (k_tgsigqueueinfo(info->si_pid, SIGUSR1, info))
+	if (k_tgsigqueueinfo(getpid(), syscall(__NR_gettid), SIGUSR1, info))
 		(errno == ENOSYS ? perror_msg_and_skip : perror_msg_and_fail)(
 			"rt_tgsigqueueinfo");
 
-	printf("rt_tgsigqueueinfo(%u, %u, %s, {si_signo=%s"
-		", si_code=SI_QUEUE, si_errno=ENOENT, si_pid=%d"
+	pidns_print_leader();
+	printf("rt_tgsigqueueinfo(%d%s, %d%s, %s, {si_signo=%s"
+		", si_code=SI_QUEUE, si_errno=ENOENT, si_pid=%d%s"
 		", si_uid=%d, si_value={int=%d, ptr=%p}}) = 0\n",
-		info->si_pid, info->si_pid, "SIGUSR1", "SIGUSR1",
-		info->si_pid, info->si_uid, info->si_value.sival_int,
+		info->si_pid, pidns_pid2str(PT_TGID),
+		info->si_pid, pidns_pid2str(PT_TID),
+		"SIGUSR1", "SIGUSR1",
+		info->si_pid, pidns_pid2str(PT_TGID),
+		info->si_uid, info->si_value.sival_int,
 		info->si_value.sival_ptr);
 
+	pidns_print_leader();
 	puts("+++ exited with 0 +++");
 	return 0;
 }
diff --git a/tests/sched_xetaffinity--pidns-translation.c b/tests/sched_xetaffinity--pidns-translation.c
new file mode 100644
index 00000000..814e3989
--- /dev/null
+++ b/tests/sched_xetaffinity--pidns-translation.c
@@ -0,0 +1,2 @@
+#define PIDNS_TRANSLATION
+#include "sched_xetaffinity.c"
diff --git a/tests/sched_xetaffinity.c b/tests/sched_xetaffinity.c
index cebff3ab..2e508ca3 100644
--- a/tests/sched_xetaffinity.c
+++ b/tests/sched_xetaffinity.c
@@ -10,6 +10,7 @@
 
 #include "tests.h"
 #include "scno.h"
+#include "pidns.h"
 #include <sched.h>
 
 #if defined __NR_sched_getaffinity && defined __NR_sched_setaffinity \
@@ -41,8 +42,11 @@ setaffinity(unsigned long pid, unsigned long size, void *set)
 int
 main(void)
 {
+	PIDNS_TEST_INIT;
+
 	unsigned int cpuset_size = 1;
 	const pid_t pid = getpid();
+	const char *pid_str = pidns_pid2str(PT_TGID);
 
 	while (cpuset_size) {
 		assert(getaffinity(pid, cpuset_size, NULL) == -1);
@@ -50,18 +54,21 @@ main(void)
 			break;
 		if (EINVAL != errno)
 			perror_msg_and_skip("sched_getaffinity");
-		printf("sched_getaffinity(%d, %u, NULL) = %s\n",
-		       pid, cpuset_size, errstr);
+		pidns_print_leader();
+		printf("sched_getaffinity(%d%s, %u, NULL) = %s\n",
+		       pid, pid_str, cpuset_size, errstr);
 		cpuset_size <<= 1;
 	}
 	assert(cpuset_size);
-	printf("sched_getaffinity(%d, %u, NULL) = %s\n",
-	       pid, cpuset_size, errstr);
+	pidns_print_leader();
+	printf("sched_getaffinity(%d%s, %u, NULL) = %s\n",
+	       pid, pid_str, cpuset_size, errstr);
 
 	cpu_set_t *cpuset = tail_alloc(cpuset_size);
 	getaffinity(pid, cpuset_size, cpuset + 1);
-	printf("sched_getaffinity(%d, %u, %p) = %s\n",
-	       pid, cpuset_size, cpuset + 1, errstr);
+	pidns_print_leader();
+	printf("sched_getaffinity(%d%s, %u, %p) = %s\n",
+	       pid, pid_str, cpuset_size, cpuset + 1, errstr);
 
 	int ret_size = getaffinity(pid, cpuset_size, cpuset);
 	if (ret_size < 0)
@@ -69,7 +76,8 @@ main(void)
 				    pid, (unsigned) cpuset_size, cpuset, errstr);
 	assert(ret_size <= (int) cpuset_size);
 
-	printf("sched_getaffinity(%d, %u, [", pid, cpuset_size);
+	pidns_print_leader();
+	printf("sched_getaffinity(%d%s, %u, [", pid, pid_str, cpuset_size);
 	const char *sep;
 	unsigned int i, cpu;
 	for (i = 0, cpu = 0, sep = ""; i < (unsigned) ret_size * 8; ++i) {
@@ -85,8 +93,9 @@ main(void)
 	CPU_SET_S(cpu, cpuset_size, cpuset);
 	if (setaffinity(pid, cpuset_size, cpuset))
 		perror_msg_and_skip("sched_setaffinity");
-	printf("sched_setaffinity(%d, %u, [%u]) = 0\n",
-	       pid, cpuset_size, cpu);
+	pidns_print_leader();
+	printf("sched_setaffinity(%d%s, %u, [%u]) = 0\n",
+	       pid, pid_str, cpuset_size, cpu);
 
 	const unsigned int big_size = cpuset_size < 128 ? 128 : cpuset_size * 2;
 	cpuset = tail_alloc(big_size);
@@ -95,7 +104,8 @@ main(void)
 		perror_msg_and_fail("sched_getaffinity(%d, %u, %p) = %s\n",
 				    pid, big_size, cpuset, errstr);
 	assert(ret_size <= (int) big_size);
-	printf("sched_getaffinity(%d, %u, [", pid, big_size);
+	pidns_print_leader();
+	printf("sched_getaffinity(%d%s, %u, [", pid, pid_str, big_size);
 	for (i = 0, sep = ""; i < (unsigned) ret_size * 8; ++i) {
 		if (CPU_ISSET_S(i, (unsigned) ret_size, cpuset)) {
 			printf("%s%u", sep, i);
@@ -104,6 +114,7 @@ main(void)
 	}
 	printf("]) = %s\n", errstr);
 
+	pidns_print_leader();
 	puts("+++ exited with 0 +++");
 	return 0;
 }
diff --git a/tests/sched_xetattr--pidns-translation.c b/tests/sched_xetattr--pidns-translation.c
new file mode 100644
index 00000000..c152023d
--- /dev/null
+++ b/tests/sched_xetattr--pidns-translation.c
@@ -0,0 +1,2 @@
+#define PIDNS_TRANSLATION
+#include "sched_xetattr.c"
diff --git a/tests/sched_xetattr.c b/tests/sched_xetattr.c
index c63d7a80..4a76b2d6 100644
--- a/tests/sched_xetattr.c
+++ b/tests/sched_xetattr.c
@@ -15,6 +15,7 @@
 # include <stdio.h>
 # include <sched.h>
 # include <unistd.h>
+# include "pidns.h"
 # include "sched_attr.h"
 # include "xlat.h"
 # include "xlat/schedulers.h"
@@ -41,6 +42,8 @@ sys_sched_setattr(kernel_ulong_t pid, kernel_ulong_t attr, kernel_ulong_t flags)
 int
 main(void)
 {
+	PIDNS_TEST_INIT;
+
 	static const kernel_ulong_t bogus_pid =
 		(kernel_ulong_t) 0xdefacedfacefeedULL;
 	static const kernel_ulong_t bogus_size =
@@ -48,20 +51,28 @@ main(void)
 	static const kernel_ulong_t bogus_flags =
 		(kernel_ulong_t) 0xdefaceddeadc0deULL;
 
+	const int pid = getpid();
+	const char *pid_str = pidns_pid2str(PT_TGID);
+
 	TAIL_ALLOC_OBJECT_CONST_PTR(struct sched_attr, attr);
 	TAIL_ALLOC_OBJECT_CONST_PTR(unsigned int, psize);
 	void *const efault = attr + 1;
 
-	sys_sched_getattr(0, 0, 0, 0);
-	printf("sched_getattr(0, NULL, 0, 0) = %s\n", errstr);
+	sys_sched_getattr(pid, 0, 0, 0);
+	pidns_print_leader();
+	printf("sched_getattr(%d%s, NULL, 0, 0) = %s\n",
+		pid, pid_str, errstr);
 
 	sys_sched_getattr(0, (unsigned long) attr, 0, 0);
+	pidns_print_leader();
 	printf("sched_getattr(0, %p, 0, 0) = %s\n", attr, errstr);
 
 	sys_sched_getattr(bogus_pid, 0, 0, 0);
+	pidns_print_leader();
 	printf("sched_getattr(%d, NULL, 0, 0) = %s\n", (int) bogus_pid, errstr);
 
 	sys_sched_getattr(-1U, (unsigned long) attr, bogus_size, bogus_flags);
+	pidns_print_leader();
 	printf("sched_getattr(-1, %p, %s%u, %u) = %s\n",
 	       attr,
 # if defined __arm64__ || defined __aarch64__
@@ -72,11 +83,13 @@ main(void)
 	       (unsigned) bogus_size, (unsigned) bogus_flags, errstr);
 
 	sys_sched_getattr(0, (unsigned long) efault, SCHED_ATTR_MIN_SIZE, 0);
+	pidns_print_leader();
 	printf("sched_getattr(0, %p, %u, 0) = %s\n",
 	       efault, (unsigned) SCHED_ATTR_MIN_SIZE, errstr);
 
 	if (sys_sched_getattr(0, (unsigned long) attr, SCHED_ATTR_MIN_SIZE, 0))
 		perror_msg_and_skip("sched_getattr");
+	pidns_print_leader();
 	printf("sched_getattr(0, {size=%u, sched_policy=", attr->size);
 	printxval(schedulers, attr->sched_policy, NULL);
 	printf(", sched_flags=%s, sched_nice=%d, sched_priority=%u"
@@ -91,11 +104,13 @@ main(void)
 	       (unsigned) SCHED_ATTR_MIN_SIZE);
 
 	sys_sched_getattr(0, (unsigned long) efault, sizeof(*attr), 0);
+	pidns_print_leader();
 	printf("sched_getattr(0, %p, %u, 0) = %s\n",
 	       efault, (unsigned) sizeof(*attr), errstr);
 
 	if (sys_sched_getattr(0, (unsigned long) attr, sizeof(*attr), 0))
 		perror_msg_and_skip("sched_getattr");
+	pidns_print_leader();
 	printf("sched_getattr(0, {size=%u, sched_policy=", attr->size);
 	printxval(schedulers, attr->sched_policy, NULL);
 	printf(", sched_flags=%s, sched_nice=%d, sched_priority=%u"
@@ -121,11 +136,13 @@ main(void)
 			  F8ILL_KULONG_MASK | sizeof(*attr), F8ILL_KULONG_MASK);
 # if defined __arm64__ || defined __aarch64__
 	if (rc) {
+		pidns_print_leader();
 		printf("sched_getattr(0, %p, 0xffffffff<<32|%u, 0) = %s\n",
 		       attr, (unsigned) sizeof(*attr), errstr);
 	} else
 # endif
 	{
+		pidns_print_leader();
 		printf("sched_getattr(0, {size=%u, sched_policy=", attr->size);
 		printxval(schedulers, attr->sched_policy, NULL);
 		printf(", sched_flags=%s, sched_nice=%d, sched_priority=%u"
@@ -146,13 +163,16 @@ main(void)
 	}
 
 	sys_sched_setattr(bogus_pid, 0, 0);
+	pidns_print_leader();
 	printf("sched_setattr(%d, NULL, 0) = %s\n", (int) bogus_pid, errstr);
 
 	attr->sched_flags |= 1;
 
-	if (sys_sched_setattr(0, (unsigned long) attr, 0))
+	if (sys_sched_setattr(pid, (unsigned long) attr, 0))
 		perror_msg_and_skip("sched_setattr");
-	printf("sched_setattr(0, {size=%u, sched_policy=", attr->size);
+	pidns_print_leader();
+	printf("sched_setattr(%d%s, {size=%u, sched_policy=",
+		pid, pid_str, attr->size);
 	printxval(schedulers, attr->sched_policy, NULL);
 	printf(", sched_flags=%s, sched_nice=%d, sched_priority=%u"
 	       ", sched_runtime=%" PRIu64 ", sched_deadline=%" PRIu64
@@ -172,6 +192,7 @@ main(void)
 
 	sys_sched_setattr(F8ILL_KULONG_MASK, (unsigned long) attr,
 			  F8ILL_KULONG_MASK);
+	pidns_print_leader();
 	printf("sched_setattr(0, {size=%u, sched_policy=", attr->size);
 	printxval(schedulers, attr->sched_policy, NULL);
 	printf(", sched_flags=%s, sched_nice=%d, sched_priority=%u"
@@ -193,11 +214,13 @@ main(void)
 	*psize = attr->size;
 
 	sys_sched_setattr(0, (unsigned long) psize, 0);
+	pidns_print_leader();
 	printf("sched_setattr(0, %p, 0) = %s\n", psize, errstr);
 
 	attr->size = 0;
 
 	sys_sched_setattr(0, (unsigned long) attr, 0);
+	pidns_print_leader();
 	printf("sched_setattr(0, {size=%u, sched_policy=", attr->size);
 	printxval(schedulers, attr->sched_policy, NULL);
 	printf(", sched_flags=%s, sched_nice=%d, sched_priority=%u"
@@ -213,12 +236,14 @@ main(void)
 	attr->size = 1;
 
 	sys_sched_setattr(0, (unsigned long) attr, 0);
+	pidns_print_leader();
 	printf("sched_setattr(0, {size=%u} => {size=%u}, 0) = %s\n",
 	       1, attr->size, errstr);
 
 	attr->size = SCHED_ATTR_MIN_SIZE - 1;
 
 	sys_sched_setattr(0, (unsigned long) attr, 0);
+	pidns_print_leader();
 	printf("sched_setattr(0, {size=%u} => {size=%u}, 0) = %s\n",
 	       SCHED_ATTR_MIN_SIZE - 1, attr->size, errstr);
 
@@ -232,6 +257,7 @@ main(void)
 	attr->sched_period = 0xded1ca7edda7aca7ULL;
 
 	sys_sched_setattr(bogus_pid, (unsigned long) attr, bogus_flags);
+	pidns_print_leader();
 	printf("sched_setattr(%d, {size=%u, sched_policy=%#x /* SCHED_??? */, "
 	       "sched_flags=%#" PRIx64 " /* SCHED_FLAG_??? */, "
 	       "sched_nice=%d, sched_priority=%u, sched_runtime=%" PRIu64 ", "
@@ -274,6 +300,7 @@ main(void)
 	attr->sched_period = 0xded1ca7edda7aca7ULL;
 
 	sys_sched_setattr(bogus_pid, (unsigned long) attr, bogus_flags);
+	pidns_print_leader();
 	printf("sched_setattr(%d, {size=%u, sched_policy=%#x /* SCHED_??? */, "
 	       "sched_flags=SCHED_FLAG_RESET_ON_FORK|SCHED_FLAG_RECLAIM|"
 	       "SCHED_FLAG_DL_OVERRUN|0x80, "
@@ -296,11 +323,13 @@ main(void)
 		const kernel_ulong_t ill = f8ill_ptr_to_kulong(attr);
 
 		sys_sched_getattr(0, ill, sizeof(*attr), 0);
+		pidns_print_leader();
 		printf("sched_getattr(0, %#llx, %u, 0) = %s\n",
 		       (unsigned long long) ill, (unsigned) sizeof(*attr),
 		       errstr);
 
 		sys_sched_setattr(0, ill, 0);
+		pidns_print_leader();
 		printf("sched_setattr(0, %#llx, 0) = %s\n",
 		       (unsigned long long) ill, errstr);
 	}
@@ -310,6 +339,7 @@ main(void)
 	attr->sched_flags = 0x8fULL;
 
 	sys_sched_setattr(bogus_pid, (unsigned long) attr, bogus_flags);
+	pidns_print_leader();
 	printf("sched_setattr(%d, {size=%u, "
 	       "sched_flags=SCHED_FLAG_RESET_ON_FORK|SCHED_FLAG_RECLAIM|"
 	       "SCHED_FLAG_DL_OVERRUN|SCHED_FLAG_KEEP_POLICY|0x80, "
@@ -329,11 +359,13 @@ main(void)
 		const kernel_ulong_t ill = f8ill_ptr_to_kulong(attr);
 
 		sys_sched_getattr(0, ill, sizeof(*attr), 0);
+		pidns_print_leader();
 		printf("sched_getattr(0, %#llx, %u, 0) = %s\n",
 		       (unsigned long long) ill, (unsigned) sizeof(*attr),
 		       errstr);
 
 		sys_sched_setattr(0, ill, 0);
+		pidns_print_leader();
 		printf("sched_setattr(0, %#llx, 0) = %s\n",
 		       (unsigned long long) ill, errstr);
 	}
@@ -342,6 +374,7 @@ main(void)
 	attr->sched_flags = 0xe7ULL;
 
 	sys_sched_setattr(bogus_pid, (unsigned long) attr, bogus_flags);
+	pidns_print_leader();
 	printf("sched_setattr(%d, {size=%u, sched_policy=%#x /* SCHED_??? */, "
 	       "sched_flags=SCHED_FLAG_RESET_ON_FORK|SCHED_FLAG_RECLAIM|"
 	       "SCHED_FLAG_DL_OVERRUN|SCHED_FLAG_UTIL_CLAMP_MIN"
@@ -365,11 +398,13 @@ main(void)
 		const kernel_ulong_t ill = f8ill_ptr_to_kulong(attr);
 
 		sys_sched_getattr(0, ill, sizeof(*attr), 0);
+		pidns_print_leader();
 		printf("sched_getattr(0, %#llx, %u, 0) = %s\n",
 		       (unsigned long long) ill, (unsigned) sizeof(*attr),
 		       errstr);
 
 		sys_sched_setattr(0, ill, 0);
+		pidns_print_leader();
 		printf("sched_setattr(0, %#llx, 0) = %s\n",
 		       (unsigned long long) ill, errstr);
 	}
@@ -377,6 +412,7 @@ main(void)
 	attr->sched_flags = 0xcaffee90LL;
 
 	sys_sched_setattr(bogus_pid, (unsigned long) attr, bogus_flags);
+	pidns_print_leader();
 	printf("sched_setattr(%d, {size=%u, sched_flags=SCHED_FLAG_KEEP_PARAMS"
 	       "|0xcaffee80, sched_util_min=%u, sched_util_max=%u}, %u) = %s\n",
 	       (int) bogus_pid,
@@ -389,15 +425,18 @@ main(void)
 		const kernel_ulong_t ill = f8ill_ptr_to_kulong(attr);
 
 		sys_sched_getattr(0, ill, sizeof(*attr), 0);
+		pidns_print_leader();
 		printf("sched_getattr(0, %#llx, %u, 0) = %s\n",
 		       (unsigned long long) ill, (unsigned) sizeof(*attr),
 		       errstr);
 
 		sys_sched_setattr(0, ill, 0);
+		pidns_print_leader();
 		printf("sched_setattr(0, %#llx, 0) = %s\n",
 		       (unsigned long long) ill, errstr);
 	}
 
+	pidns_print_leader();
 	puts("+++ exited with 0 +++");
 	return 0;
 }
diff --git a/tests/sched_xetparam--pidns-translation.c b/tests/sched_xetparam--pidns-translation.c
new file mode 100644
index 00000000..9fb3e579
--- /dev/null
+++ b/tests/sched_xetparam--pidns-translation.c
@@ -0,0 +1,2 @@
+#define PIDNS_TRANSLATION
+#include "sched_xetparam.c"
diff --git a/tests/sched_xetparam.c b/tests/sched_xetparam.c
index de3915b2..aa9c68cc 100644
--- a/tests/sched_xetparam.c
+++ b/tests/sched_xetparam.c
@@ -7,6 +7,7 @@
 
 #include "tests.h"
 #include "scno.h"
+# include "pidns.h"
 
 #if defined __NR_sched_getparam && defined __NR_sched_setparam
 
@@ -17,18 +18,27 @@
 int
 main(void)
 {
+	PIDNS_TEST_INIT;
+
 	struct sched_param *const param =
 		tail_alloc(sizeof(struct sched_param));
 
-	long rc = syscall(__NR_sched_getparam, 0, param);
-	printf("sched_getparam(0, [%d]) = %ld\n",
-	       param->sched_priority, rc);
+	const int pid = getpid();
+	const char *pid_str = pidns_pid2str(PT_TGID);
+
+	long rc = syscall(__NR_sched_getparam, pid, param);
+	pidns_print_leader();
+	printf("sched_getparam(%d%s, [%d]) = %ld\n",
+	       pid, pid_str, param->sched_priority, rc);
 
 	param->sched_priority = -1;
-	rc = syscall(__NR_sched_setparam, 0, param);
-	printf("sched_setparam(0, [%d]) = %ld %s (%m)\n",
+	rc = syscall(__NR_sched_setparam, pid, param);
+	pidns_print_leader();
+	printf("sched_setparam(%d%s, [%d]) = %ld %s (%m)\n",
+	       pid, pid_str,
 	       param->sched_priority, rc, errno2name());
 
+	pidns_print_leader();
 	puts("+++ exited with 0 +++");
 	return 0;
 }
diff --git a/tests/sched_xetscheduler--pidns-translation.c b/tests/sched_xetscheduler--pidns-translation.c
new file mode 100644
index 00000000..78b794b2
--- /dev/null
+++ b/tests/sched_xetscheduler--pidns-translation.c
@@ -0,0 +1,2 @@
+#define PIDNS_TRANSLATION
+#include "sched_xetscheduler.c"
diff --git a/tests/sched_xetscheduler.c b/tests/sched_xetscheduler.c
index 047e8676..91b5e32d 100644
--- a/tests/sched_xetscheduler.c
+++ b/tests/sched_xetscheduler.c
@@ -7,6 +7,7 @@
 
 #include "tests.h"
 #include "scno.h"
+#include "pidns.h"
 
 #if defined __NR_sched_getscheduler && defined __NR_sched_setscheduler
 
@@ -17,8 +18,13 @@
 int
 main(void)
 {
+	PIDNS_TEST_INIT;
+
 	TAIL_ALLOC_OBJECT_CONST_PTR(struct sched_param, param);
-	long rc = syscall(__NR_sched_getscheduler, 0);
+	const int pid = getpid();
+	const char *pid_str = pidns_pid2str(PT_TGID);
+
+	long rc = syscall(__NR_sched_getscheduler, pid);
 	const char *scheduler;
 	switch (rc) {
 		case SCHED_FIFO:
@@ -50,33 +56,43 @@ main(void)
 		default:
 			scheduler = "SCHED_OTHER";
 	}
-	printf("sched_getscheduler(0) = %ld (%s)\n",
-	       rc, scheduler);
+	pidns_print_leader();
+	printf("sched_getscheduler(%d%s) = %ld (%s)\n",
+	       pid, pid_str, rc, scheduler);
 
 	rc = syscall(__NR_sched_getscheduler, -1);
+	pidns_print_leader();
 	printf("sched_getscheduler(-1) = %s\n", sprintrc(rc));
 
 	param->sched_priority = -1;
 
-	rc = syscall(__NR_sched_setscheduler, 0, SCHED_FIFO, NULL);
-	printf("sched_setscheduler(0, SCHED_FIFO, NULL) = %s\n", sprintrc(rc));
+	rc = syscall(__NR_sched_setscheduler, pid, SCHED_FIFO, NULL);
+	pidns_print_leader();
+	printf("sched_setscheduler(%d%s, SCHED_FIFO, NULL) = %s\n",
+	       pid, pid_str, sprintrc(rc));
 
-	rc = syscall(__NR_sched_setscheduler, 0, SCHED_FIFO, param + 1);
-	printf("sched_setscheduler(0, SCHED_FIFO, %p) = %s\n", param + 1,
-	       sprintrc(rc));
+	rc = syscall(__NR_sched_setscheduler, pid, SCHED_FIFO, param + 1);
+	pidns_print_leader();
+	printf("sched_setscheduler(%d%s, SCHED_FIFO, %p) = %s\n",
+	       pid, pid_str, param + 1, sprintrc(rc));
 
-	rc = syscall(__NR_sched_setscheduler, 0, 0xfaceda7a, param);
-	printf("sched_setscheduler(0, %#x /* SCHED_??? */, [%d]) = %s\n",
-	       0xfaceda7a, param->sched_priority, sprintrc(rc));
+	rc = syscall(__NR_sched_setscheduler, pid, 0xfaceda7a, param);
+	pidns_print_leader();
+	printf("sched_setscheduler(%d%s, %#x /* SCHED_??? */, [%d]) = %s\n",
+	       pid, pid_str, 0xfaceda7a,
+	       param->sched_priority, sprintrc(rc));
 
 	rc = syscall(__NR_sched_setscheduler, -1, SCHED_FIFO, param);
+	pidns_print_leader();
 	printf("sched_setscheduler(-1, SCHED_FIFO, [%d]) = %s\n",
 	       param->sched_priority, sprintrc(rc));
 
-	rc = syscall(__NR_sched_setscheduler, 0, SCHED_FIFO, param);
-	printf("sched_setscheduler(0, SCHED_FIFO, [%d]) = %s\n",
-	       param->sched_priority, sprintrc(rc));
+	rc = syscall(__NR_sched_setscheduler, pid, SCHED_FIFO, param);
+	pidns_print_leader();
+	printf("sched_setscheduler(%d%s, SCHED_FIFO, [%d]) = %s\n",
+	       pid, pid_str, param->sched_priority, sprintrc(rc));
 
+	pidns_print_leader();
 	puts("+++ exited with 0 +++");
 	return 0;
 }
diff --git a/tests/signal_receive--pidns-translation.c b/tests/signal_receive--pidns-translation.c
new file mode 100644
index 00000000..b4e3b2f8
--- /dev/null
+++ b/tests/signal_receive--pidns-translation.c
@@ -0,0 +1,2 @@
+#define PIDNS_TRANSLATION
+#include "signal_receive.c"
diff --git a/tests/signal_receive.c b/tests/signal_receive.c
index ad3b4ebd..70441a9e 100644
--- a/tests/signal_receive.c
+++ b/tests/signal_receive.c
@@ -8,6 +8,7 @@
  */
 
 #include "tests.h"
+#include "pidns.h"
 #include <signal.h>
 #include <stdio.h>
 #include <unistd.h>
@@ -26,10 +27,13 @@ handler(int sig, siginfo_t *info, void *ucontext)
 int
 main(void)
 {
+	PIDNS_TEST_INIT;
+
 	static const char prefix[] = "KERNEL BUG";
 	int printed = 0;
 
 	const int pid = getpid();
+	const char *pid_str = pidns_pid2str(PT_TGID);
 	const int uid = geteuid();
 
 	for (int sig = 1; sig <= 31; ++sig) {
@@ -73,10 +77,13 @@ main(void)
 		const int e_pid = s_pid;
 		const int e_uid = s_uid;
 #endif
-		printf("kill(%d, %s) = 0\n", pid, signal2name(sig));
-		printf("--- %s {si_signo=%s, si_code=SI_USER, si_pid=%d"
+		pidns_print_leader();
+		printf("kill(%d%s, %s) = 0\n", pid, pid_str, signal2name(sig));
+		pidns_print_leader();
+		printf("--- %s {si_signo=%s, si_code=SI_USER, si_pid=%d%s"
 		       ", si_uid=%d} ---\n",
-		       signal2name(sig), signal2name(e_sig), e_pid, e_uid);
+		       signal2name(sig), signal2name(e_sig),
+		       e_pid, pid_str, e_uid);
 
 		if (s_code || sig != s_sig || pid != s_pid || uid != s_uid) {
 			/*
@@ -91,11 +98,11 @@ main(void)
 			}
 			fprintf(stderr,
 				"%s: expected: si_signo=%d, si_code=%d"
-				", si_pid=%d, si_uid=%d\n"
+				", si_pid=%d%s, si_uid=%d\n"
 				"%s: received: si_signo=%d, si_code=%d"
-				", si_pid=%d, si_uid=%d\n",
-				prefix, sig, SI_USER, pid, uid,
-				prefix, sig, s_code, s_pid, s_uid);
+				", si_pid=%d%s, si_uid=%d\n",
+				prefix, sig, SI_USER, pid, pid_str, uid,
+				prefix, sig, s_code, s_pid, pid_str, s_uid);
 		}
 	}
 
@@ -104,6 +111,7 @@ main(void)
 			"*** PLEASE FIX THE KERNEL ***\n", prefix);
 	}
 
+	pidns_print_leader();
 	puts("+++ exited with 0 +++");
 	return 0;
 }
diff --git a/tests/so_peercred--pidns-translation.c b/tests/so_peercred--pidns-translation.c
new file mode 100644
index 00000000..402bbcfe
--- /dev/null
+++ b/tests/so_peercred--pidns-translation.c
@@ -0,0 +1,2 @@
+#define PIDNS_TRANSLATION
+#include "so_peercred.c"
diff --git a/tests/so_peercred.c b/tests/so_peercred.c
index 151bb175..20188bdb 100644
--- a/tests/so_peercred.c
+++ b/tests/so_peercred.c
@@ -9,6 +9,7 @@
  */
 
 #include "tests.h"
+#include "pidns.h"
 
 #include <stddef.h>
 #include <stdio.h>
@@ -53,6 +54,8 @@ so_str(void)
 int
 main(void)
 {
+	PIDNS_TEST_INIT;
+
 	TAIL_ALLOC_OBJECT_CONST_PTR(struct ucred, peercred);
 	TAIL_ALLOC_OBJECT_CONST_PTR(socklen_t, len);
 
@@ -75,6 +78,8 @@ main(void)
 	struct ucred *const gid_truncated =
 		tail_alloc(sizeof_gid_truncated);
 
+	const char *pid_str = pidns_pid2str(PT_TGID);
+
 	int sv[2];
 	if (socketpair(AF_UNIX, SOCK_STREAM, 0, sv))
                 perror_msg_and_skip("socketpair AF_UNIX SOCK_STREAM");
@@ -82,8 +87,10 @@ main(void)
 	/* classic getsockopt */
 	*len = sizeof(*peercred);
 	get_peercred(sv[0], peercred, len);
+	pidns_print_leader();
 	printf("getsockopt(%d, %s", sv[0], so_str());
 	PRINT_FIELD_D(", {", *peercred, pid);
+	printf("%s", pid_str);
 	PRINT_FIELD_UID(", ", *peercred, uid);
 	PRINT_FIELD_UID(", ", *peercred, gid);
 	printf("}, [%d]) = %s\n", *len, errstr);
@@ -91,14 +98,17 @@ main(void)
 	/* getsockopt with zero optlen */
 	*len = 0;
 	get_peercred(sv[0], peercred, len);
+	pidns_print_leader();
 	printf("getsockopt(%d, %s, %p, [0]) = %s\n",
 	       sv[0], so_str(), peercred, errstr);
 
 	/* getsockopt with optlen larger than necessary - shortened */
 	*len = sizeof(*peercred) + 1;
 	get_peercred(sv[0], peercred, len);
+	pidns_print_leader();
 	printf("getsockopt(%d, %s", sv[0], so_str());
 	PRINT_FIELD_D(", {", *peercred, pid);
+	printf("%s", pid_str);
 	PRINT_FIELD_UID(", ", *peercred, uid);
 	PRINT_FIELD_UID(", ", *peercred, gid);
 	printf("}, [%u->%d]) = %s\n",
@@ -110,6 +120,7 @@ main(void)
 	 */
 	*len = sizeof_pid_truncated;
 	get_peercred(sv[0], pid_truncated, len);
+	pidns_print_leader();
 	printf("getsockopt(%d, %s, {pid=", sv[0], so_str());
 	print_quoted_hex(pid_truncated, *len);
 	printf("}, [%d]) = %s\n", *len, errstr);
@@ -120,8 +131,10 @@ main(void)
 	 */
 	*len = sizeof_pid;
 	get_peercred(sv[0], pid, len);
+	pidns_print_leader();
 	printf("getsockopt(%d, %s", sv[0], so_str());
 	PRINT_FIELD_D(", {", *pid, pid);
+	printf("%s", pid_str);
 	printf("}, [%d]) = %s\n", *len, errstr);
 
 	/*
@@ -136,8 +149,10 @@ main(void)
 	 * to struct ucred.pid field.
 	 */
 	memcpy(uid, uid_truncated, sizeof_uid_truncated);
+	pidns_print_leader();
 	printf("getsockopt(%d, %s", sv[0], so_str());
 	PRINT_FIELD_D(", {", *uid, pid);
+	printf("%s", pid_str);
 	printf(", uid=");
 	print_quoted_hex(&uid->uid, sizeof_uid_truncated -
 				    offsetof(struct ucred, uid));
@@ -149,8 +164,10 @@ main(void)
 	 */
 	*len = sizeof_uid;
 	get_peercred(sv[0], uid, len);
+	pidns_print_leader();
 	printf("getsockopt(%d, %s", sv[0], so_str());
 	PRINT_FIELD_D(", {", *uid, pid);
+	printf("%s", pid_str);
 	PRINT_FIELD_UID(", ", *uid, uid);
 	printf("}, [%d]) = %s\n", *len, errstr);
 
@@ -166,8 +183,10 @@ main(void)
 	 * to struct ucred.pid and struct ucred.uid fields.
 	 */
 	memcpy(peercred, gid_truncated, sizeof_gid_truncated);
+	pidns_print_leader();
 	printf("getsockopt(%d, %s", sv[0], so_str());
 	PRINT_FIELD_D(", {", *peercred, pid);
+	printf("%s", pid_str);
 	PRINT_FIELD_UID(", ", *peercred, uid);
 	printf(", gid=");
 	print_quoted_hex(&peercred->gid, sizeof_gid_truncated -
@@ -177,14 +196,17 @@ main(void)
 	/* getsockopt optval EFAULT */
 	*len = sizeof(*peercred);
 	get_peercred(sv[0], &peercred->uid, len);
+	pidns_print_leader();
 	printf("getsockopt(%d, %s, %p, [%d]) = %s\n",
 	       sv[0], so_str(), &peercred->uid, *len, errstr);
 
 	/* getsockopt optlen EFAULT */
 	get_peercred(sv[0], peercred, len + 1);
+	pidns_print_leader();
 	printf("getsockopt(%d, %s, %p, %p) = %s\n",
 	       sv[0], so_str(), peercred, len + 1, errstr);
 
+	pidns_print_leader();
 	puts("+++ exited with 0 +++");
 	return 0;
 }
diff --git a/tests/xet_robust_list--pidns-translation.c b/tests/xet_robust_list--pidns-translation.c
new file mode 100644
index 00000000..e0477267
--- /dev/null
+++ b/tests/xet_robust_list--pidns-translation.c
@@ -0,0 +1,2 @@
+#define PIDNS_TRANSLATION
+#include "xet_robust_list.c"
diff --git a/tests/xet_robust_list.c b/tests/xet_robust_list.c
index 43239c8b..b5751b0a 100644
--- a/tests/xet_robust_list.c
+++ b/tests/xet_robust_list.c
@@ -8,6 +8,7 @@
 
 #include "tests.h"
 #include "scno.h"
+#include "pidns.h"
 
 #if defined __NR_get_robust_list && defined __NR_set_robust_list
 
@@ -30,27 +31,36 @@ sprintaddr(void *addr)
 int
 main(void)
 {
+	PIDNS_TEST_INIT;
+
 	const pid_t pid = getpid();
+	const char *pid_str = pidns_pid2str(PT_TGID);
 	const long long_pid = (unsigned long) (0xdeadbeef00000000LL | pid);
 	TAIL_ALLOC_OBJECT_CONST_PTR(void *, p_head);
 	TAIL_ALLOC_OBJECT_CONST_PTR(size_t, p_len);
 
 	if (syscall(__NR_get_robust_list, long_pid, p_head, p_len))
 		perror_msg_and_skip("get_robust_list");
-	printf("get_robust_list(%d, [%s], [%lu]) = 0\n",
-	       (int) pid, sprintaddr(*p_head), (unsigned long) *p_len);
+	pidns_print_leader();
+	printf("get_robust_list(%d%s, [%s], [%lu]) = 0\n",
+	       pid, pid_str, sprintaddr(*p_head),
+	       (unsigned long) *p_len);
 
 	void *head = tail_alloc(*p_len);
 	if (syscall(__NR_set_robust_list, head, *p_len))
 		perror_msg_and_skip("set_robust_list");
+	pidns_print_leader();
 	printf("set_robust_list(%p, %lu) = 0\n",
 	       head, (unsigned long) *p_len);
 
 	if (syscall(__NR_get_robust_list, long_pid, p_head, p_len))
 		perror_msg_and_skip("get_robust_list");
-	printf("get_robust_list(%d, [%s], [%lu]) = 0\n",
-	       (int) pid, sprintaddr(*p_head), (unsigned long) *p_len);
+	pidns_print_leader();
+	printf("get_robust_list(%d%s, [%s], [%lu]) = 0\n",
+	       pid, pid_str, sprintaddr(*p_head),
+	       (unsigned long) *p_len);
 
+	pidns_print_leader();
 	puts("+++ exited with 0 +++");
 	return 0;
 }
diff --git a/tests/xetpgid--pidns-translation.c b/tests/xetpgid--pidns-translation.c
new file mode 100644
index 00000000..b6469628
--- /dev/null
+++ b/tests/xetpgid--pidns-translation.c
@@ -0,0 +1,2 @@
+#define PIDNS_TRANSLATION
+#include "xetpgid.c"
diff --git a/tests/xetpgid.c b/tests/xetpgid.c
index 9b070af2..411edfc7 100644
--- a/tests/xetpgid.c
+++ b/tests/xetpgid.c
@@ -10,6 +10,7 @@
 
 #include "tests.h"
 #include "scno.h"
+#include "pidns.h"
 
 #if defined __NR_getpgid && defined __NR_setpgid
 
@@ -19,13 +20,21 @@
 int
 main(void)
 {
-	const int pid = getpid();
-	long rc = syscall(__NR_getpgid, F8ILL_KULONG_MASK | pid);
-	printf("getpgid(%d) = %ld\n", pid, rc);
-
-	rc = syscall(__NR_setpgid, F8ILL_KULONG_MASK, F8ILL_KULONG_MASK | pid);
-	printf("setpgid(0, %d) = %ld\n", pid, rc);
+	PIDNS_TEST_INIT;
 
+	const int pid = getpid();
+	long pgid = syscall(__NR_getpgid, F8ILL_KULONG_MASK | pid);
+	pidns_print_leader();
+	printf("getpgid(%d%s) = %ld%s\n", pid, pidns_pid2str(PT_TGID),
+		pgid, pidns_pid2str(PT_PGID));
+
+	long rc = syscall(__NR_setpgid, F8ILL_KULONG_MASK,
+		F8ILL_KULONG_MASK | pgid);
+	pidns_print_leader();
+	printf("setpgid(0, %ld%s) = %s\n", pgid, pidns_pid2str(PT_PGID),
+		sprintrc(rc));
+
+	pidns_print_leader();
 	puts("+++ exited with 0 +++");
 	return 0;
 }
diff --git a/tests/xetpriority--pidns-translation.c b/tests/xetpriority--pidns-translation.c
new file mode 100644
index 00000000..c93669cb
--- /dev/null
+++ b/tests/xetpriority--pidns-translation.c
@@ -0,0 +1,2 @@
+#define PIDNS_TRANSLATION
+#include "xetpriority.c"
diff --git a/tests/xetpriority.c b/tests/xetpriority.c
index 2d61bd10..dd38217d 100644
--- a/tests/xetpriority.c
+++ b/tests/xetpriority.c
@@ -7,6 +7,7 @@
 
 #include "tests.h"
 #include "scno.h"
+#include "pidns.h"
 
 #if defined __NR_getpriority && defined __NR_setpriority
 
@@ -17,15 +18,30 @@
 int
 main(void)
 {
+	PIDNS_TEST_INIT;
+
 	const int pid = getpid();
+	const int pgid = getpgid(0);
+
 	long rc = syscall(__NR_getpriority, PRIO_PROCESS,
 			  F8ILL_KULONG_MASK | pid);
-	printf("getpriority(PRIO_PROCESS, %d) = %ld\n", pid, rc);
+	pidns_print_leader();
+	printf("getpriority(PRIO_PROCESS, %d%s) = %ld\n",
+		pid, pidns_pid2str(PT_TGID), rc);
 
 	rc = syscall(__NR_setpriority, PRIO_PROCESS,
 		     F8ILL_KULONG_MASK | pid, F8ILL_KULONG_MASK);
-	printf("setpriority(PRIO_PROCESS, %d, 0) = %s\n", pid, sprintrc(rc));
+	pidns_print_leader();
+	printf("setpriority(PRIO_PROCESS, %d%s, 0) = %s\n",
+		pid, pidns_pid2str(PT_TGID), sprintrc(rc));
+
+	rc = syscall(__NR_getpriority, PRIO_PGRP,
+			  F8ILL_KULONG_MASK | pgid);
+	pidns_print_leader();
+	printf("getpriority(PRIO_PGRP, %d%s) = %ld\n",
+		pgid, pidns_pid2str(PT_PGID), rc);
 
+	pidns_print_leader();
 	puts("+++ exited with 0 +++");
 	return 0;
 }
-- 
2.27.0


From uzonyi.akos at gmail.com  Thu Aug  6 19:02:09 2020
From: uzonyi.akos at gmail.com (=?UTF-8?q?=C3=81kos=20Uzonyi?=)
Date: Thu,  6 Aug 2020 21:02:09 +0200
Subject: [PATCH v6 3/5] Use get_proc_pid for /proc paths
In-Reply-To: <20200806190211.118721-1-uzonyi.akos@gmail.com>
References: <20200806190211.118721-1-uzonyi.akos@gmail.com>
Message-ID: <20200806190211.118721-4-uzonyi.akos@gmail.com>

* mmap_cache.c (mmap_cache_rebuild_if_invalid): Use proc pid instead of
tcp->pid for /proc path.
* util.c (getfdproto): Likewise.
(pidfd_get_pid): Likewise.
* pathtrace.c (getfdpath_pid): Likewise.
* strace.c (attach_tcb): Likewise.
---
 mmap_cache.c | 2 +-
 pathtrace.c  | 5 ++++-
 strace.c     | 2 +-
 util.c       | 7 +++++--
 4 files changed, 11 insertions(+), 5 deletions(-)

diff --git a/mmap_cache.c b/mmap_cache.c
index 89c62254..9825df26 100644
--- a/mmap_cache.c
+++ b/mmap_cache.c
@@ -84,7 +84,7 @@ mmap_cache_rebuild_if_invalid(struct tcb *tcp, const char *caller)
 		return MMAP_CACHE_REBUILD_READY;
 
 	char filename[sizeof("/proc/4294967296/maps")];
-	xsprintf(filename, "/proc/%u/maps", tcp->pid);
+	xsprintf(filename, "/proc/%u/maps", get_proc_pid(tcp));
 
 	FILE *fp = fopen_stream(filename, "r");
 	if (!fp) {
diff --git a/pathtrace.c b/pathtrace.c
index 5b60762b..74717a8a 100644
--- a/pathtrace.c
+++ b/pathtrace.c
@@ -87,7 +87,10 @@ getfdpath_pid(pid_t pid, int fd, char *buf, unsigned bufsize)
 	if (fd < 0)
 		return -1;
 
-	xsprintf(linkpath, "/proc/%u/fd/%u", pid, fd);
+	int proc_pid = 0;
+	translate_pid(NULL, pid, PT_TID, &proc_pid);
+
+	xsprintf(linkpath, "/proc/%u/fd/%u", proc_pid, fd);
 	n = readlink(linkpath, buf, bufsize - 1);
 	/*
 	 * NB: if buf is too small, readlink doesn't fail,
diff --git a/strace.c b/strace.c
index 249533ea..ef23f08f 100644
--- a/strace.c
+++ b/strace.c
@@ -1196,7 +1196,7 @@ attach_tcb(struct tcb *const tcp)
 	unsigned int ntid = 0, nerr = 0;
 
 	if (followfork && tcp->pid != strace_child &&
-	    xsprintf(procdir, task_path, tcp->pid) > 0 &&
+	    xsprintf(procdir, task_path, get_proc_pid(tcp)) > 0 &&
 	    (dir = opendir(procdir)) != NULL) {
 		struct_dirent *de;
 
diff --git a/util.c b/util.c
index 094e5818..d87d022e 100644
--- a/util.c
+++ b/util.c
@@ -501,7 +501,7 @@ getfdproto(struct tcb *tcp, int fd)
 	if (fd < 0)
 		return SOCK_PROTO_UNKNOWN;
 
-	xsprintf(path, "/proc/%u/fd/%u", tcp->pid, fd);
+	xsprintf(path, "/proc/%u/fd/%u", get_proc_pid(tcp), fd);
 	r = getxattr(path, "system.sockprotoname", buf, bufsize - 1);
 	if (r <= 0)
 		return SOCK_PROTO_UNKNOWN;
@@ -582,8 +582,11 @@ printdev(struct tcb *tcp, int fd, const char *path)
 pid_t
 pidfd_get_pid(pid_t pid_of_fd, int fd)
 {
+	int proc_pid = 0;
+	translate_pid(NULL, pid_of_fd, PT_TID, &proc_pid);
+
 	char fdi_path[sizeof("/proc/%u/fdinfo/%u") + 2 * sizeof(int) * 3];
-	xsprintf(fdi_path, "/proc/%u/fdinfo/%u", pid_of_fd, fd);
+	xsprintf(fdi_path, "/proc/%u/fdinfo/%u", proc_pid, fd);
 
 	FILE *f = fopen_stream(fdi_path, "r");
 	if (!f)
-- 
2.27.0


From uzonyi.akos at gmail.com  Thu Aug  6 19:02:07 2020
From: uzonyi.akos at gmail.com (=?UTF-8?q?=C3=81kos=20Uzonyi?=)
Date: Thu,  6 Aug 2020 21:02:07 +0200
Subject: [PATCH v6 1/5] PID namespace translation support
In-Reply-To: <20200806190211.118721-1-uzonyi.akos@gmail.com>
References: <20200806190211.118721-1-uzonyi.akos@gmail.com>
Message-ID: <20200806190211.118721-2-uzonyi.akos@gmail.com>

* defs.h (pidns_translation): New variable.
(tcb): Add pid_ns field.
(RVAL_MASK): Change value from 013 to 017.
(RVAL_TID, RVAL_SID, RVAL_TGID, RVAL_PGID): New definitions.
(pid_type): New enum.
(pidns_init, translate_pid, get_proc_pid, printpid, printpid_tgid_pgid):
New function declarations.
* largefile_wrappers.h (fstat_fd): New macro.
* pidns.c: New file.
* trie.c: New file.
* trie.h: New file.
* Makefile.am (libstrace_a_SOURCES): Add trie.c, trie.h, pidns.c.
* strace.c (pidns_translation): New variable.
(init): Add --pidns-translation option.
* syscall.c (syscall_exiting_trace): Handle RVAL_* return values.
* NEWS: Mention this.
* strace.1.in: Add description for new option.

Co-Authored-by: Eugene Syromyatnikov <evgsyr at gmail.com>
---
 Makefile.am          |   3 +
 NEWS                 |   1 +
 defs.h               |  53 +++-
 largefile_wrappers.h |   2 +
 pidns.c              | 613 +++++++++++++++++++++++++++++++++++++++++++
 strace.1.in          |   4 +
 strace.c             |   9 +
 syscall.c            |  15 ++
 trie.c               | 250 ++++++++++++++++++
 trie.h               |  89 +++++++
 10 files changed, 1038 insertions(+), 1 deletion(-)
 create mode 100644 pidns.c
 create mode 100644 trie.c
 create mode 100644 trie.h

diff --git a/Makefile.am b/Makefile.am
index f5447811..73c22035 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -233,6 +233,7 @@ libstrace_a_SOURCES =	\
 	personality.c	\
 	pidfd_getfd.c	\
 	pidfd_open.c	\
+	pidns.c		\
 	pkeys.c		\
 	poll.c		\
 	prctl.c		\
@@ -344,6 +345,8 @@ libstrace_a_SOURCES =	\
 	time.c		\
 	times.c		\
 	trace_event.h	\
+	trie.c 		\
+	trie.h 		\
 	truncate.c	\
 	ubi.c		\
 	ucopy.c		\
diff --git a/NEWS b/NEWS
index b83f9e80..9086fde9 100644
--- a/NEWS
+++ b/NEWS
@@ -14,6 +14,7 @@ Noteworthy changes in release ?.? (????-??-??)
     KEYCTL_*, KVM_*, LOOP_*, NDA_*, RTC_*, TCA_*, STATX_*, and *_MAGIC
     constants.
   * Updated lists of ioctl commands from Linux 5.8.
+  * Added --pidns-translation opition for PID namespace translation.
 
 * Bug fixes
   * Added statx syscall to %fstat trace class.
diff --git a/defs.h b/defs.h
index f7ac54f3..692fa0d3 100644
--- a/defs.h
+++ b/defs.h
@@ -280,6 +280,13 @@ struct tcb {
 	struct timespec etime;	/* Syscall entry time (CLOCK_MONOTONIC) */
 	struct timespec delay_expiration_time; /* When does the delay end */
 
+	/*
+	 * The ID of the PID namespace of this process
+	 * (inode number of /proc/<pid>/ns/pid)
+	 * (0: not initialized)
+	 */
+	unsigned int pid_ns;
+
 	struct mmap_cache_t *mmap_cache;
 
 	/*
@@ -413,7 +420,11 @@ extern const struct xlat whence_codes[];
 # define RVAL_HEX	001	/* hex format */
 # define RVAL_OCTAL	002	/* octal format */
 # define RVAL_FD		010	/* file descriptor */
-# define RVAL_MASK	013	/* mask for these values */
+# define RVAL_TID	011	/* task ID */
+# define RVAL_SID	012	/* session ID */
+# define RVAL_TGID	013	/* thread group ID */
+# define RVAL_PGID	014	/* process group ID */
+# define RVAL_MASK	017	/* mask for these values */
 
 # define RVAL_STR	020	/* Print `auxstr' field after return val */
 # define RVAL_NONE	040	/* Print nothing */
@@ -428,6 +439,16 @@ extern const struct xlat whence_codes[];
 
 # define indirect_ipccall(tcp) (tcp_sysent(tcp)->sys_flags & TRACE_INDIRECT_SUBCALL)
 
+enum pid_type {
+	PT_TID,
+	PT_TGID,
+	PT_PGID,
+	PT_SID,
+
+	PT_COUNT,
+	PT_NONE = -1
+};
+
 enum sock_proto {
 	SOCK_PROTO_UNKNOWN,
 	SOCK_PROTO_UNIX,
@@ -469,6 +490,7 @@ extern int Tflag_scale;
 extern int Tflag_width;
 extern bool iflag;
 extern bool count_wallclock;
+extern unsigned int pidns_translation;
 /* are we filtering traces based on paths? */
 extern struct path_set {
 	const char **paths_selected;
@@ -983,6 +1005,27 @@ print_local_array_ex(struct tcb *tcp,
 extern kernel_ulong_t *
 fetch_indirect_syscall_args(struct tcb *, kernel_ulong_t addr, unsigned int n_args);
 
+extern void pidns_init(void);
+
+/**
+ * Returns the pid of the tracee as present in /proc (can be different from
+ * tcp->pid if /proc and the tracee process are in different PID namespaces).
+ */
+extern int get_proc_pid(struct tcb *);
+
+/**
+ * Translates a pid from tracee's namespace to our namepace.
+ *
+ * @param tcp             The tcb of the tracee
+ *                        (NULL: from_id is in strace's namespace. Useful for
+ *                         getting the proc PID of from_id)
+ * @param from_id         The id to be translated
+ * @param type            The PID type of from_id
+ * @param proc_pid_ptr    If not NULL, writes the proc PID to this location
+ */
+extern int translate_pid(struct tcb *, int dest_id, enum pid_type type,
+		    int *proc_pid_ptr);
+
 extern void
 dumpiov_in_msghdr(struct tcb *, kernel_ulong_t addr, kernel_ulong_t data_size);
 
@@ -1058,6 +1101,14 @@ printfd(struct tcb *tcp, int fd)
  * of the tracee the descriptor tcp).  This is a stub.
  */
 extern void printfd_pid_tracee_ns(struct tcb *tcp, pid_t pid, int fd);
+
+extern void printpid(struct tcb *, int pid, enum pid_type type);
+
+/**
+ * Prints pid as a TGID if positive, and PGID if negative
+ * (like the first argument of kill).
+ */
+extern void printpid_tgid_pgid(struct tcb *, int pid);
 extern void print_sockaddr(struct tcb *, const void *sa, int len);
 extern bool
 print_inet_addr(int af, const void *addr, unsigned int len, const char *var_name);
diff --git a/largefile_wrappers.h b/largefile_wrappers.h
index 116e7048..9d8f5c92 100644
--- a/largefile_wrappers.h
+++ b/largefile_wrappers.h
@@ -29,6 +29,7 @@
 #  else
 #   define fcntl_fd fcntl
 #  endif
+#  define fstat_fd fstat64
 #  define strace_stat_t struct stat64
 #  define stat_file stat64
 #  define struct_dirent struct dirent64
@@ -39,6 +40,7 @@
 #  define open_file open
 #  define fopen_stream fopen
 #  define fcntl_fd fcntl
+#  define fstat_fd fstat
 #  define strace_stat_t struct stat
 #  define stat_file stat
 #  define struct_dirent struct dirent
diff --git a/pidns.c b/pidns.c
new file mode 100644
index 00000000..6a99fbb4
--- /dev/null
+++ b/pidns.c
@@ -0,0 +1,613 @@
+/*
+ * Copyright (c) 2020 ?kos Uzonyi <uzonyi.akos at gmail.com>
+ * All rights reserved.
+ *
+ * SPDX-License-Identifier: LGPL-2.1-or-later
+ */
+
+#include "defs.h"
+
+
+#include <dirent.h>
+#include <fcntl.h>
+#include <stdint.h>
+#include <string.h>
+#include <unistd.h>
+
+#include <asm/unistd.h>
+
+#include <sys/ioctl.h>
+#include <sys/param.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+
+#include "largefile_wrappers.h"
+#include "trie.h"
+#include "nsfs.h"
+#include "xmalloc.h"
+#include "xstring.h"
+
+/**
+ * Key:   PID NS ID
+ * Value: a btree:
+ *           Key:   a process PID in NS
+ *           Value: the process's PID as present in /proc
+ */
+static struct trie *ns_pid_to_proc_pid[PT_COUNT];
+
+/**
+ * Key:   Proc PID
+ * Value: stuct proc_data
+ */
+static struct trie *proc_data_cache;
+
+static bool ns_get_parent_enotty = false;
+
+static const char tid_str[]  = "NSpid:\t";
+static const char tgid_str[] = "NStgid:\t";
+static const char pgid_str[] = "NSpgid:\t";
+static const char sid_str[]  = "NSsid:\t";
+
+static const struct {
+	const char *str;
+	size_t size;
+} id_strs[PT_COUNT] = {
+	[PT_TID] =  { tid_str,  sizeof(tid_str)  - 1 },
+	[PT_TGID] = { tgid_str, sizeof(tgid_str) - 1 },
+	[PT_PGID] = { pgid_str, sizeof(pgid_str) - 1 },
+	[PT_SID] =  { sid_str,  sizeof(sid_str)  - 1 },
+};
+
+
+/**
+ * Limit on PID NS hierarchy depth, imposed since Linux 3.7. NS traversal
+ * is not possible before Linux 4.9, so we consider this limit pretty universal.
+ */
+#define MAX_NS_DEPTH 32
+
+static const size_t ns_id_size = sizeof(unsigned int);
+static const uint8_t ptr_sz_lg = (sizeof(void *) == 8 ? 6 : 5);
+
+static int pid_max;
+static uint8_t pid_max_size, pid_max_size_lg;
+
+struct proc_data {
+	int proc_pid;
+	int ns_count;
+	unsigned int ns_hierarchy[MAX_NS_DEPTH];
+	int id_count[PT_COUNT];
+	int id_hierarchy[PT_COUNT][MAX_NS_DEPTH];
+};
+
+/**
+ * Helper function for creating a trie.
+ *
+ * For node_key_bits and data_block_key_bits 4 is used (so trie height is 32 / 4
+ * = 8, and node sizes are 8 byte * 2^4 = 128 bytes), which seems to be a good
+ * tradeoff between between memory usage and lookup time. It should not be too
+ * large, since there can be large holes between PIDs, and it would be just a
+ * waste of memory having large nodes with lot of NULL pointers in them.
+ */
+static struct trie *
+create_trie_4(uint8_t key_size, uint8_t item_size_lg, uint64_t empty_value)
+{
+	struct trie *t = trie_create(key_size, item_size_lg, 4, 4, empty_value);
+	if (!t)
+		error_msg_and_die("creating trie failed");
+
+	return t;
+}
+
+void
+pidns_init(void)
+{
+	if (proc_data_cache)
+		return;
+
+	pid_max = INT_MAX;
+	if (read_int_from_file("/proc/sys/kernel/pid_max", &pid_max) < 0)
+		debug_func_perror_msg("reading /proc/sys/kernel/pid_max");
+	pid_max_size = ilog2_32(pid_max - 1) + 1;
+	pid_max_size_lg = ilog2_32(pid_max_size - 1) + 1;
+
+	for (int i = 0; i < PT_COUNT; i++)
+		ns_pid_to_proc_pid[i] = create_trie_4(ns_id_size, ptr_sz_lg, 0);
+
+	proc_data_cache = create_trie_4(pid_max_size, ptr_sz_lg, 0);
+}
+
+static void
+put_proc_pid(unsigned int ns, int ns_pid, enum pid_type type, int proc_pid)
+{
+	struct trie *b = (struct trie *) (uintptr_t) trie_get(ns_pid_to_proc_pid[type], ns);
+	if (!b) {
+		b = create_trie_4(pid_max_size, pid_max_size_lg, 0);
+		trie_set(ns_pid_to_proc_pid[type], ns, (uint64_t) (uintptr_t) b);
+	}
+	trie_set(b, ns_pid, proc_pid);
+}
+
+static int
+get_cached_proc_pid(unsigned int ns, int ns_pid, enum pid_type type)
+{
+	struct trie *b = (struct trie *) (uintptr_t)
+		trie_get(ns_pid_to_proc_pid[type], ns);
+	if (!b)
+		return 0;
+
+	return trie_get(b, ns_pid);
+}
+
+/**
+ * Helper function, converts pid to string, or to "self" for pid == 0.
+ * Uses static buffer for operation.
+ */
+static const char *
+pid_to_str(pid_t pid)
+{
+	if (!pid)
+		return "self";
+
+	static char buf[sizeof("-2147483648")];
+	xsprintf(buf, "%d", pid);
+	return buf;
+}
+
+/**
+ * Returns a list of PID NS IDs for the specified PID.
+ *
+ * @param proc_pid PID (as present in /proc) to get information for.
+ * @param ns_buf   Pointer to buffer that is able to contain at least
+ *                 ns_buf_size items.
+ * @return         Amount of NS in list. 0 indicates error.
+ */
+static size_t
+get_ns_hierarchy(int proc_pid, unsigned int *ns_buf, size_t ns_buf_size)
+{
+	char path[PATH_MAX + 1];
+	xsprintf(path, "/proc/%s/ns/pid", pid_to_str(proc_pid));
+
+	int fd = open_file(path, O_RDONLY);
+	if (fd < 0)
+		return 0;
+
+	size_t n = 0;
+	while (n < ns_buf_size) {
+		strace_stat_t st;
+		if (fstat_fd(fd, &st))
+			break;
+
+		ns_buf[n++] = st.st_ino;
+		if (n >= ns_buf_size)
+			break;
+
+		if (ns_get_parent_enotty)
+			break;
+
+		int parent_fd = ioctl(fd, NS_GET_PARENT);
+		if (parent_fd < 0) {
+			switch (errno) {
+			case EPERM:
+				break;
+
+			case ENOTTY:
+				ns_get_parent_enotty = true;
+				error_msg("NS_* ioctl commands are not "
+					  "supported by the kernel");
+				break;
+
+			default:
+				perror_func_msg("ioctl(NS_GET_PARENT)");
+				break;
+			}
+
+			break;
+		}
+
+		close(fd);
+		fd = parent_fd;
+	}
+
+	close(fd);
+
+	return n;
+}
+
+/**
+ * Get list of IDs present in NS* proc status record. IDs are placed as they are
+ * stored in /proc (from top to bottom of NS hierarchy).
+ *
+ * @param proc_pid    PID (as present in /proc) to get information for.
+ * @param id_buf      Pointer to buffer that is able to contain at least
+ *                    MAX_NS_DEPTH items. Can be NULL.
+ * @param type        Type of ID requested.
+ * @return            Number of items stored in id_list. 0 indicates error.
+ */
+static size_t
+get_id_list(int proc_pid, int *id_buf, enum pid_type type)
+{
+	const char *ns_str = id_strs[type].str;
+	size_t ns_str_size = id_strs[type].size;
+
+	size_t n = 0;
+
+	char status_path[PATH_MAX + 1];
+	xsprintf(status_path, "/proc/%s/status", pid_to_str(proc_pid));
+	FILE *f = fopen_stream(status_path, "r");
+	if (!f)
+		return 0;
+
+	char *line = NULL;
+	size_t linesize = 0;
+	char *p = NULL;
+
+	while (getline(&line, &linesize, f) > 0) {
+		if (strncmp(line, ns_str, ns_str_size) == 0) {
+			p = line + ns_str_size;
+			break;
+		}
+	}
+
+	while (p) {
+		errno = 0;
+		long id = strtol(p, NULL, 10);
+
+		if (errno || (id < 1) || (id > INT_MAX)) {
+			perror_func_msg("converting pid to int");
+			break;
+		}
+
+		if (id_buf)
+			id_buf[n] = (int) id;
+
+		n++;
+		strsep(&p, "\t");
+	}
+
+	free(line);
+	fclose(f);
+
+	return n;
+}
+
+/**
+ * Returns whether the /proc filesystem's PID namespace is same as strace's.
+ */
+static bool
+is_proc_ours(void)
+{
+	static int cached_val = -1;
+
+	if (cached_val < 0)
+		cached_val = get_id_list(0, NULL, PT_TID) == 1;
+
+	return cached_val;
+}
+
+/**
+ * Returns the PID namespace of the tracee
+ */
+static unsigned int
+get_ns(struct tcb *tcp)
+{
+	if (!tcp->pid_ns) {
+		int proc_pid = 0;
+		translate_pid(NULL, tcp->pid, PT_TID, &proc_pid);
+
+		if (proc_pid)
+			get_ns_hierarchy(proc_pid, &tcp->pid_ns, 1);
+	}
+
+	return tcp->pid_ns;
+}
+
+/**
+ * Returns the PID namespace of strace
+ */
+static unsigned int
+get_our_ns(void)
+{
+	static unsigned int our_ns = 0;
+	static bool our_ns_initialised = false;
+
+	if (!our_ns_initialised) {
+		get_ns_hierarchy(0, &our_ns, 1);
+		our_ns_initialised = true;
+	}
+
+	return our_ns;
+}
+
+/**
+ * Returns the cached proc_data struct associated with proc_pid.
+ * If none found, allocates a new proc_data.
+ */
+static struct proc_data *
+get_or_create_proc_data(int proc_pid)
+{
+	struct proc_data *pd = (struct proc_data *) (uintptr_t)
+		trie_get(proc_data_cache, proc_pid);
+
+	if (!pd) {
+		pd = calloc(1, sizeof(*pd));
+		if (!pd)
+			return NULL;
+
+		pd->proc_pid = proc_pid;
+		trie_set(proc_data_cache, proc_pid, (uint64_t) (uintptr_t) pd);
+	}
+
+	return pd;
+}
+
+/**
+ * Updates the proc_data from /proc
+ * If the process does not exists, returns false, and frees the proc_data
+ */
+static bool
+update_proc_data(struct proc_data *pd, enum pid_type type)
+{
+	pd->ns_count = get_ns_hierarchy(pd->proc_pid,
+		pd->ns_hierarchy, MAX_NS_DEPTH);
+	if (!pd->ns_count)
+		goto fail;
+
+	pd->id_count[type] = get_id_list(pd->proc_pid,
+		pd->id_hierarchy[type], type);
+	if (!pd->id_count[type])
+		goto fail;
+
+	return true;
+
+fail:
+	trie_set(proc_data_cache, pd->proc_pid, (uint64_t) (uintptr_t) NULL);
+	free(pd);
+	return false;
+}
+
+/**
+ * Paramters for id translation
+ */
+struct translate_id_params {
+	/* The result (output) */
+	int result_id;
+	/* The proc data of the process (output) */
+	struct proc_data *pd;
+
+	/* The namespace to be translated from */
+	unsigned int from_ns;
+	/* The id to be translated */
+	int from_id;
+	/* The type of the id */
+	enum pid_type type;
+};
+
+/**
+ * Translates an id to our namespace, given the proc_pid of the process,
+ * by reading files in /proc.
+ *
+ * @param tip      The parameters
+ * @param proc_pid The proc pid of the process.
+ *                 If 0, use the cached values in tip->pd.
+ */
+static void
+translate_id_proc_pid(struct translate_id_params *tip, int proc_pid)
+{
+	struct proc_data *pd = proc_pid ?
+		get_or_create_proc_data(proc_pid) :
+		tip->pd;
+
+	tip->result_id = 0;
+	tip->pd = NULL;
+
+	if (!pd)
+		return;
+
+	if (proc_pid && !update_proc_data(pd, tip->type))
+		return;
+
+	if (!pd->ns_count || (pd->id_count[tip->type] < pd->ns_count))
+		return;
+
+	int our_ns_id_idx = pd->id_count[tip->type] - pd->ns_count;
+
+	for (int i = 0; i < pd->ns_count; i++) {
+		if (pd->ns_hierarchy[i] != tip->from_ns)
+			continue;
+
+		int id_idx = pd->id_count[tip->type] - i - 1;
+		if (pd->id_hierarchy[tip->type][id_idx] != tip->from_id)
+			return;
+
+		tip->result_id = pd->id_hierarchy[tip->type][our_ns_id_idx];
+		tip->pd = pd;
+		return;
+	}
+}
+
+/**
+ * Translates an id to our namespace, by reading all proc entries in dir.
+ *
+ * @param tip            The parameters
+ * @param path           The path of the dir to be read.
+ * @param read_task_dir  Whether recurse to "task" subdirectory.
+ */
+static void
+translate_id_dir(struct translate_id_params *tip, const char *path,
+                 bool read_task_dir)
+{
+	DIR *dir = opendir(path);
+	if (!dir) {
+		debug_func_perror_msg("opening dir: %s", path);
+		return;
+	}
+
+	while (!tip->result_id) {
+		errno = 0;
+		struct_dirent *entry = read_dir(dir);
+		if (!entry) {
+			if (errno)
+				perror_func_msg("readdir");
+
+			break;
+		}
+
+		if (entry->d_type != DT_DIR)
+			continue;
+
+		errno = 0;
+		long proc_pid = strtol(entry->d_name, NULL, 10);
+		if (errno)
+			continue;
+		if ((proc_pid < 1) || (proc_pid > INT_MAX))
+			continue;
+
+		if (read_task_dir) {
+			char task_dir_path[PATH_MAX + 1];
+			xsprintf(task_dir_path, "/proc/%ld/task", proc_pid);
+			translate_id_dir(tip, task_dir_path, false);
+		}
+
+		if (tip->result_id)
+			break;
+
+		translate_id_proc_pid(tip, proc_pid);
+	}
+
+	closedir(dir);
+}
+
+/**
+ * Iterator function of the proc_data_cache for id translation.
+ * If the cache contains the id we are looking for, reads the corresponding
+ * directory in /proc, and if cache is valid, saves the result.
+ */
+static void
+proc_data_cache_iterator_fn(void* fn_data, uint64_t key, uint64_t val)
+{
+	struct translate_id_params *tip = (struct translate_id_params *)fn_data;
+	struct proc_data *pd = (struct proc_data *) (uintptr_t) val;
+
+	if (!pd)
+		return;
+
+	/* Result already found in an earlier iteration */
+	if (tip->result_id)
+		return;
+
+	/* Translate from cache */
+	tip->pd = pd;
+	translate_id_proc_pid(tip, 0);
+	if (!tip->result_id)
+		return;
+
+	/* Now translate from actual data in /proc, to check cache validity */
+	translate_id_proc_pid(tip, pd->proc_pid);
+}
+
+int
+translate_pid(struct tcb *tcp, int from_id, enum pid_type type,
+              int *proc_pid_ptr)
+{
+	if ((from_id <= 0) || (type < 0) || (type >= PT_COUNT))
+		return 0;
+
+	const unsigned int our_ns = get_our_ns();
+	if (!our_ns)
+		return 0;
+
+	struct translate_id_params tip = {
+		.result_id = 0,
+		.pd = NULL,
+		.from_ns = tcp ? get_ns(tcp) : our_ns,
+		.from_id = from_id,
+		.type = type,
+	};
+
+	if (!tip.from_ns)
+		return 0;
+
+	/* If translation is trivial */
+	if (tip.from_ns == our_ns && (is_proc_ours() || !proc_pid_ptr)) {
+		if (proc_pid_ptr)
+			*proc_pid_ptr = from_id;
+
+		tip.result_id = tip.from_id;
+		goto exit;
+	}
+
+	if (ns_get_parent_enotty)
+		return 0;
+
+	/* Look for a cached proc_pid for this (from_ns, from_id) pair */
+	int cached_proc_pid = get_cached_proc_pid(tip.from_ns, tip.from_id,
+		tip.type);
+	if (cached_proc_pid) {
+		translate_id_proc_pid(&tip, cached_proc_pid);
+		if (tip.result_id)
+			goto exit;
+	}
+
+	/* Iterate through the cache, find potential proc_data */
+	trie_iterate_keys(proc_data_cache, 0, pid_max,
+		proc_data_cache_iterator_fn, &tip);
+	/* (proc_data_cache_iterator_fn takes care about updating proc_data) */
+	if (tip.result_id)
+		goto exit;
+
+	/* No cache helped, read all entries in /proc */
+	translate_id_dir(&tip, "/proc", true);
+
+exit:
+	if (tip.pd) {
+		if (tip.pd->proc_pid)
+			put_proc_pid(tip.from_ns, tip.from_id, tip.type,
+				tip.pd->proc_pid);
+
+		if (proc_pid_ptr)
+			*proc_pid_ptr = tip.pd->proc_pid;
+	}
+
+	return tip.result_id;
+}
+
+int
+get_proc_pid(struct tcb *tcp)
+{
+	int ret = 0;
+
+	if (is_proc_ours())
+		ret = tcp->pid;
+	else
+		translate_pid(NULL, tcp->pid, PT_TID, &ret);
+
+	return ret;
+}
+
+static void
+printpid_translation(struct tcb *tcp, int pid, enum pid_type type)
+{
+	if (!pidns_translation)
+		return;
+
+	int strace_pid = translate_pid(tcp, pid, type, NULL);
+	if (strace_pid && strace_pid != pid)
+		tprintf_comment("%d in strace's PID NS", strace_pid);
+}
+
+void
+printpid(struct tcb *tcp, int pid, enum pid_type type)
+{
+	tprintf("%d", pid);
+	printpid_translation(tcp, pid, type);
+}
+
+void
+printpid_tgid_pgid(struct tcb *tcp, int pid)
+{
+	tprintf("%d", pid);
+	if (pid > 0)
+		printpid_translation(tcp,  pid, PT_TGID);
+	else if (pid < -1)
+		printpid_translation(tcp, -pid, PT_PGID);
+}
diff --git a/strace.1.in b/strace.1.in
index 3b21caec..adca194c 100644
--- a/strace.1.in
+++ b/strace.1.in
@@ -1075,6 +1075,10 @@ Print all available information associated with file descritors:
 protocol-specific information associated with socket file descriptors,
 block/character device number associated with device file descriptors,
 and PIDs asociated with pidfd file descriptors.
+.TP
+.B \-\-pidns\-translation
+If strace and tracee are in different PID namespaces, print PIDs in
+strace's namespace also.
 .SS Statistics
 .TP 12
 .B \-c
diff --git a/strace.c b/strace.c
index 4c96a98b..249533ea 100644
--- a/strace.c
+++ b/strace.c
@@ -133,6 +133,8 @@ static unsigned int daemonized_tracer;
 static int post_attach_sigstop = TCB_IGNORE_ONE_SIGSTOP;
 #define use_seize (post_attach_sigstop == 0)
 
+unsigned int pidns_translation;
+
 static bool detach_on_execve;
 
 static int exit_code;
@@ -1998,6 +2000,8 @@ init(int argc, char *argv[])
 
 	os_release = get_os_release();
 
+	pidns_init();
+
 	shared_log = stderr;
 	set_sortby(DEFAULT_SORTBY);
 	set_personality(DEFAULT_PERSONALITY);
@@ -2022,6 +2026,7 @@ init(int argc, char *argv[])
 		GETOPT_FOLLOWFORKS,
 		GETOPT_OUTPUT_SEPARATELY,
 		GETOPT_TS,
+		GETOPT_PIDNS_TRANSLATION,
 
 		GETOPT_QUAL_TRACE,
 		GETOPT_QUAL_ABBREV,
@@ -2072,6 +2077,7 @@ init(int argc, char *argv[])
 		{ "summary-wall-clock", no_argument,	   0, 'w' },
 		{ "strings-in-hex",	optional_argument, 0, GETOPT_HEX_STR },
 		{ "const-print-style",	required_argument, 0, 'X' },
+		{ "pidns-translation",	no_argument      , 0, GETOPT_PIDNS_TRANSLATION },
 		{ "successful-only",	no_argument,	   0, 'z' },
 		{ "failed-only",	no_argument,	   0, 'Z' },
 		{ "failing-only",	no_argument,	   0, 'Z' },
@@ -2285,6 +2291,9 @@ init(int argc, char *argv[])
 		case 'y':
 			yflag_short++;
 			break;
+		case GETOPT_PIDNS_TRANSLATION:
+			pidns_translation++;
+			break;
 		case 'z':
 			clear_number_set_array(status_set, 1);
 			add_number_to_set(STATUS_SUCCESSFUL, status_set);
diff --git a/syscall.c b/syscall.c
index bcc87025..0f4bab6d 100644
--- a/syscall.c
+++ b/syscall.c
@@ -937,6 +937,21 @@ syscall_exiting_trace(struct tcb *tcp, struct timespec *ts, int res)
 					tprintf("= %" PRI_kld, tcp->u_rval);
 				}
 				break;
+			case RVAL_TID:
+			case RVAL_SID:
+			case RVAL_TGID:
+			case RVAL_PGID: {
+				#define _(_t) [RVAL_##_t - RVAL_TID] = PT_##_t
+				static const enum pid_type types[] = {
+					_(TID), _(SID), _(TGID), _(PGID),
+				};
+				#undef _
+
+				tprints("= ");
+				printpid(tcp, tcp->u_rval,
+					 types[(sys_res & RVAL_MASK) - RVAL_TID]);
+				break;
+			}
 			default:
 				error_msg("invalid rval format");
 				break;
diff --git a/trie.c b/trie.c
new file mode 100644
index 00000000..76cecc25
--- /dev/null
+++ b/trie.c
@@ -0,0 +1,250 @@
+/*
+ * Simple trie implementation for key-value mapping storage
+ *
+ * Copyright (c) 2020 ?kos Uzonyi <uzonyi.akos at gmail.com>
+ * All rights reserved.
+ *
+ * SPDX-License-Identifier: LGPL-2.1-or-later
+ */
+
+#include "defs.h"
+
+#include <assert.h>
+#include <stdbool.h>
+#include <stdint.h>
+#include <stdlib.h>
+
+#include "trie.h"
+
+static const uint8_t ptr_sz_lg = (sizeof(uint64_t *) == 8 ? 6 : 5);
+
+/**
+ * Returns lg2 of node size for the specific level of the trie. If max_depth
+ * provided is less than zero, it is calculated via trie_get_depth call.
+ */
+static uint8_t
+trie_get_node_size(struct trie *t, uint8_t depth)
+{
+	/* Last level contains data and we allow it having a different size */
+	if (depth == t->max_depth)
+		return t->data_block_key_bits + t->item_size_lg;
+	/* Last level of the tree can be smaller */
+	if (depth == t->max_depth - 1)
+		return (t->key_size - t->data_block_key_bits - 1) %
+		t->node_key_bits + 1 + ptr_sz_lg;
+
+	return t->node_key_bits + ptr_sz_lg;
+}
+
+/**
+ * Provides starting offset of bits in key corresponding to the node index
+ * at the specific level.
+ */
+static uint8_t
+trie_get_node_bit_offs(struct trie *t, uint8_t depth)
+{
+	uint8_t offs;
+
+	if (depth == t->max_depth)
+		return 0;
+
+	offs = t->data_block_key_bits;
+
+	if (depth == t->max_depth - 1)
+		return offs;
+
+	/* data_block_size + remainder */
+	offs += trie_get_node_size(t, t->max_depth - 1) - ptr_sz_lg;
+	offs += (t->max_depth - depth - 2) * t->node_key_bits;
+
+	return offs;
+}
+
+struct trie *
+trie_create(uint8_t key_size, uint8_t item_size_lg, uint8_t node_key_bits,
+            uint8_t data_block_key_bits, uint64_t empty_value)
+{
+	if (item_size_lg > 6)
+		return NULL;
+	if (key_size > 64)
+		return NULL;
+	if (node_key_bits < 1)
+		return NULL;
+	if (data_block_key_bits < 1 || data_block_key_bits > key_size)
+		return NULL;
+
+	struct trie *t = malloc(sizeof(*t));
+	if (!t)
+		return NULL;
+
+	t->empty_value = empty_value;
+	t->data = NULL;
+	t->item_size_lg = item_size_lg;
+	t->node_key_bits = node_key_bits;
+	t->data_block_key_bits = data_block_key_bits;
+	t->key_size = key_size;
+	t->max_depth = (key_size - data_block_key_bits + node_key_bits - 1)
+		/ t->node_key_bits;
+
+	return t;
+}
+
+static uint64_t *
+trie_get_node(struct trie *t, uint64_t key, bool auto_create)
+{
+	void **cur_node = &(t->data);
+
+	if (t->key_size < 64 && key > (uint64_t) 1 << t->key_size)
+		return NULL;
+
+	for (uint8_t cur_depth = 0; cur_depth <= t->max_depth; cur_depth++) {
+		uint8_t offs = trie_get_node_bit_offs(t, cur_depth);
+		uint8_t sz = trie_get_node_size(t, cur_depth);
+
+		if (!*cur_node) {
+			if (!auto_create)
+				return NULL;
+
+			*cur_node = xcalloc(1 << sz, 1);
+		}
+
+		if (cur_depth >= t->max_depth)
+			break;
+
+		size_t pos = (key >> offs) & ((1 << (sz - ptr_sz_lg)) - 1);
+		cur_node = (((void **) (*cur_node)) + pos);
+	}
+
+	return (uint64_t *) (*cur_node);
+}
+
+static void
+trie_data_block_calc_pos(struct trie *t, uint64_t key,
+                         uint64_t *pos, uint64_t *mask, uint64_t *offs)
+{
+	uint64_t key_mask;
+
+	key_mask = (1 << t->data_block_key_bits) - 1;
+	*pos = (key & key_mask) >> (6 - t->item_size_lg);
+
+	key_mask = (1 << (6 - t->item_size_lg)) - 1;
+	*offs = (key & key_mask) * (1 << t->item_size_lg);
+
+	*mask = (((uint64_t) 1 << (1 << t->item_size_lg)) - 1) << *offs;
+}
+
+bool
+trie_set(struct trie *t, uint64_t key, uint64_t val)
+{
+	uint64_t *data = trie_get_node(t, key, true);
+	if (!data)
+		return false;
+
+	uint64_t pos, mask, offs;
+	trie_data_block_calc_pos(t, key, &pos, &mask, &offs);
+
+	data[pos] &= ~mask;
+	data[pos] |= (val << offs) & mask;
+
+	return true;
+}
+
+static uint64_t
+trie_data_block_get(struct trie *t, uint64_t *data, uint64_t key)
+{
+	if (!data)
+		return t->empty_value;
+
+	uint64_t pos, mask, offs;
+	trie_data_block_calc_pos(t, key, &pos, &mask, &offs);
+
+	return (data[pos] & mask) >> offs;
+}
+
+uint64_t
+trie_get(struct trie *b, uint64_t key)
+{
+	return trie_data_block_get(b, trie_get_node(b, key, false), key);
+}
+
+static uint64_t
+trie_iterate_keys_node(struct trie *t,
+                       trie_iterate_fn fn, void *fn_data,
+                       void *node, uint64_t start, uint64_t end,
+                       uint8_t depth)
+{
+	if (start > end || !node)
+		return 0;
+
+	if (depth == t->max_depth) {
+		for (uint64_t i = start; i <= end; i++)
+			fn(fn_data, i, trie_data_block_get(t,
+				(uint64_t *) node, i));
+
+		return end - start + 1; //TODO: overflow
+	}
+
+	uint8_t parent_node_bit_off = depth == 0 ?
+		t->key_size :
+		trie_get_node_bit_offs(t, depth - 1);
+
+	uint64_t first_key_in_node = start &
+		(uint64_t) -1 << parent_node_bit_off;
+
+	uint8_t node_bit_off = trie_get_node_bit_offs(t, depth);
+	uint8_t node_key_bits = parent_node_bit_off - node_bit_off;
+	uint64_t mask = ((uint64_t) 1 << (node_key_bits)) - 1;
+	uint64_t start_index = (start >> node_bit_off) & mask;
+	uint64_t end_index = (end >> node_bit_off) & mask;
+	uint64_t child_key_count = (uint64_t) 1 << node_bit_off;
+
+	uint64_t count = 0;
+
+	for (uint64_t i = start_index; i <= end_index; i++) {
+		uint64_t child_start = first_key_in_node + i * child_key_count;
+		uint64_t child_end = first_key_in_node +
+			(i + 1) * child_key_count - 1;
+
+		if (child_start < start)
+			child_start = start;
+		if (child_end > end)
+			child_end = end;
+
+		count += trie_iterate_keys_node(t, fn, fn_data,
+			((void **) node)[i], child_start, child_end,
+			depth + 1);
+	}
+
+	return count;
+}
+
+uint64_t trie_iterate_keys(struct trie *t, uint64_t start, uint64_t end,
+                           trie_iterate_fn fn, void *fn_data)
+{
+	return trie_iterate_keys_node(t, fn, fn_data, t->data,
+		start, end, 0);
+}
+
+static void
+trie_free_node(struct trie *t, void *node, uint8_t depth)
+{
+	if (!node)
+		return;
+
+	if (depth >= t->max_depth)
+		goto free_node;
+
+	size_t sz = 1 << (trie_get_node_size(t, depth) - ptr_sz_lg);
+	for (size_t i = 0; i < sz; i++)
+		trie_free_node(t, ((void **) node)[i], depth + 1);
+
+free_node:
+	free(node);
+}
+
+void
+trie_free(struct trie *t)
+{
+	trie_free_node(t, t->data, 0);
+	free(t);
+}
diff --git a/trie.h b/trie.h
new file mode 100644
index 00000000..f7058c7e
--- /dev/null
+++ b/trie.h
@@ -0,0 +1,89 @@
+/*
+ * Simple trie interface
+ *
+ * Copyright (c) 2020 ?kos Uzonyi <uzonyi.akos at gmail.com>
+ * All rights reserved.
+ *
+ * SPDX-License-Identifier: LGPL-2.1-or-later
+ */
+
+#ifndef STRACE_TRIE_H
+#define STRACE_TRIE_H
+
+/**
+ * Trie control structure.
+ * Trie implemented here has the following properties:
+ *  * It allows storing values of the same size, the size can vary from 1 bit to
+ *    64 bit values (only power of 2 sizes are allowed).
+ *  * The key can be up to 64 bits in size.
+ *  * It has separate configuration for node size and data block size.
+ *
+ * How bits of key are used for different node levels:
+ *
+ *   highest bits                                                  lowest bits
+ *  | node_key_bits | node_key_bits | ... | <remainder> | data_block_key_bits |
+ *  \_________________________________________________________________________/
+ *                                 key_size
+ *
+ * So, the remainder is used on the lowest non-data node level.
+ *
+ * As of now, it doesn't implement any mechanisms for resizing/changing key
+ * size.  De-fragmentation is also unsupported currently.
+ */
+struct trie {
+	/** Return value of trie_get if key is not found */
+	uint64_t empty_value;
+
+	/** Pointer to root node */
+	void *data;
+
+	/** Key size in bits (0..64). */
+	uint8_t key_size;
+
+	/**
+	 * Size of the stored values in log2 bits (0..6).
+	 * (6: 64 bit values, 5: 32 bit values, ...)
+	 */
+	uint8_t item_size_lg;
+
+	/**
+	 * Number of bits in key that makes a symbol for a node.
+	 * (equals to log2 of the child count of the node)
+	 */
+	uint8_t node_key_bits;
+
+	/**
+	 * Number of bits in key that make a symbol for the data block (leaf).
+	 * (equals to log2 of the value count stored in a data block)
+	 */
+	uint8_t data_block_key_bits;
+
+	/** The depth of the data block. Caluclated from the values above */
+	uint8_t max_depth;
+};
+
+struct trie* trie_create(uint8_t key_size, uint8_t item_size_lg,
+			uint8_t node_key_bits, uint8_t data_block_key_bits,
+			uint64_t empty_value);
+
+bool trie_set(struct trie *t, uint64_t key, uint64_t val);
+uint64_t trie_get(struct trie *t, uint64_t key);
+
+typedef void (*trie_iterate_fn)(void *data, uint64_t key, uint64_t val);
+
+/**
+ * Calls trie_iterate_fn for each key-value pair where
+ * key is inside the [start, end] interval (inclusive).
+ *
+ * @param t        The trie.
+ * @param start    The start of the key interval (inclusive).
+ * @param end      The end of the key interval (inclusive).
+ * @param fn       The function to be called.
+ * @param fn_data  The value to be passed to fn.
+ */
+uint64_t trie_iterate_keys(struct trie *t, uint64_t start, uint64_t end,
+			    trie_iterate_fn fn, void *fn_data);
+
+void trie_free(struct trie *t);
+
+#endif /* !STRACE_TRIE_H */
-- 
2.27.0


From ldv at altlinux.org  Fri Aug  7 18:23:18 2020
From: ldv at altlinux.org (Dmitry V. Levin)
Date: Fri, 7 Aug 2020 21:23:18 +0300
Subject: [PATCH v6 1/5] PID namespace translation support
In-Reply-To: <20200806190211.118721-2-uzonyi.akos@gmail.com>
References: <20200806190211.118721-1-uzonyi.akos@gmail.com>
 <20200806190211.118721-2-uzonyi.akos@gmail.com>
Message-ID: <20200807182318.GA5985@altlinux.org>

On Thu, Aug 06, 2020 at 09:02:07PM +0200, ?kos Uzonyi wrote:
[...]
> diff --git a/NEWS b/NEWS
> index b83f9e80..9086fde9 100644
> --- a/NEWS
> +++ b/NEWS
> @@ -14,6 +14,7 @@ Noteworthy changes in release ?.? (????-??-??)
>      KEYCTL_*, KVM_*, LOOP_*, NDA_*, RTC_*, TCA_*, STATX_*, and *_MAGIC
>      constants.
>    * Updated lists of ioctl commands from Linux 5.8.
> +  * Added --pidns-translation opition for PID namespace translation.

Typo?

> @@ -983,6 +1005,27 @@ print_local_array_ex(struct tcb *tcp,
>  extern kernel_ulong_t *
>  fetch_indirect_syscall_args(struct tcb *, kernel_ulong_t addr, unsigned int n_args);
>  
> +extern void pidns_init(void);
> +
> +/**
> + * Returns the pid of the tracee as present in /proc (can be different from
> + * tcp->pid if /proc and the tracee process are in different PID namespaces).
> + */
> +extern int get_proc_pid(struct tcb *);

I'm still puzzled what /proc are you talking about, the tracer's /proc or
the tracee's /proc.

> @@ -1058,6 +1101,14 @@ printfd(struct tcb *tcp, int fd)
>   * of the tracee the descriptor tcp).  This is a stub.
>   */
>  extern void printfd_pid_tracee_ns(struct tcb *tcp, pid_t pid, int fd);
> +
> +extern void printpid(struct tcb *, int pid, enum pid_type type);

Although this might look obvious, I suggest adding a short comment for
printpid, too, to make it clear that printpid prints the pid given
in the tracee's pid namespace.

> +/**
> + * Key:   Proc PID
> + * Value: stuct proc_data

Typo?

> +/**
> + * Helper function for creating a trie.
> + *
> + * For node_key_bits and data_block_key_bits 4 is used (so trie height is 32 / 4
> + * = 8, and node sizes are 8 byte * 2^4 = 128 bytes), which seems to be a good
> + * tradeoff between between memory usage and lookup time. It should not be too

Typo?

> + * large, since there can be large holes between PIDs, and it would be just a
> + * waste of memory having large nodes with lot of NULL pointers in them.
> + */
> +static struct trie *
> +create_trie_4(uint8_t key_size, uint8_t item_size_lg, uint64_t empty_value)
> +{
> +	struct trie *t = trie_create(key_size, item_size_lg, 4, 4, empty_value);
> +	if (!t)
> +		error_msg_and_die("creating trie failed");
> +
> +	return t;
> +}

I believe empty_value is always 0, so why bother with the argument?

> +	while (p) {
> +		errno = 0;
> +		long id = strtol(p, NULL, 10);
> +
> +		if (errno || (id < 1) || (id > INT_MAX)) {

I don't think these extra brackets increase readability.

> +			perror_func_msg("converting pid to int");
> +			break;
> +		}

I suggest also printing the value of p in this unlikely case.

> +/**
> + * Returns whether the /proc filesystem's PID namespace is same as strace's.

Grammar: is the same.

> diff --git a/strace.1.in b/strace.1.in
> index 3b21caec..adca194c 100644
> --- a/strace.1.in
> +++ b/strace.1.in
> @@ -1075,6 +1075,10 @@ Print all available information associated with file descritors:
>  protocol-specific information associated with socket file descriptors,
>  block/character device number associated with device file descriptors,
>  and PIDs asociated with pidfd file descriptors.
> +.TP
> +.B \-\-pidns\-translation
> +If strace and tracee are in different PID namespaces, print PIDs in
> +strace's namespace also.

Changing "print PIDs in strace's namespace also" to either
"print PIDs also in strace's namespace" or
"print PIDs in strace's namespace, too" would likely result
to a more grammatically correct sentence.

> diff --git a/trie.c b/trie.c
> new file mode 100644
> index 00000000..76cecc25
> --- /dev/null
> +++ b/trie.c
> @@ -0,0 +1,250 @@
> +/*
> + * Simple trie implementation for key-value mapping storage
> + *
> + * Copyright (c) 2020 ?kos Uzonyi <uzonyi.akos at gmail.com>
> + * All rights reserved.
> + *
> + * SPDX-License-Identifier: LGPL-2.1-or-later
> + */
> +
> +#include "defs.h"
> +
> +#include <assert.h>

Does this code use assert?

> +#include <stdbool.h>
> +#include <stdint.h>
> +#include <stdlib.h>
> +
> +#include "trie.h"
> +
> +static const uint8_t ptr_sz_lg = (sizeof(uint64_t *) == 8 ? 6 : 5);

Hmm, pidns.c uses a slightly different (although essentially the same)
definition of ptr_sz_lg.

> +
> +/**
> + * Returns lg2 of node size for the specific level of the trie. If max_depth
> + * provided is less than zero, it is calculated via trie_get_depth call.
> + */
> +static uint8_t
> +trie_get_node_size(struct trie *t, uint8_t depth)

What do you mean by "If max_depth provided"?

> +struct trie *
> +trie_create(uint8_t key_size, uint8_t item_size_lg, uint8_t node_key_bits,
> +            uint8_t data_block_key_bits, uint64_t empty_value)
> +{
> +	if (item_size_lg > 6)
> +		return NULL;
> +	if (key_size > 64)
> +		return NULL;
> +	if (node_key_bits < 1)
> +		return NULL;
> +	if (data_block_key_bits < 1 || data_block_key_bits > key_size)
> +		return NULL;

Should there be a check that node_key_bits isn't too big, for consistency?

> +static uint64_t
> +trie_iterate_keys_node(struct trie *t,
> +                       trie_iterate_fn fn, void *fn_data,
> +                       void *node, uint64_t start, uint64_t end,
> +                       uint8_t depth)
> +{
> +	if (start > end || !node)
> +		return 0;
> +
> +	if (depth == t->max_depth) {
> +		for (uint64_t i = start; i <= end; i++)
> +			fn(fn_data, i, trie_data_block_get(t,
> +				(uint64_t *) node, i));
> +
> +		return end - start + 1; //TODO: overflow

Overflow?

> +	/**
> +	 * Number of bits in key that makes a symbol for a node.
> +	 * (equals to log2 of the child count of the node)
> +	 */
> +	uint8_t node_key_bits;
> +
> +	/**
> +	 * Number of bits in key that make a symbol for the data block (leaf).

Typo?

> +	 * (equals to log2 of the value count stored in a data block)
> +	 */
> +	uint8_t data_block_key_bits;
> +
> +	/** The depth of the data block. Caluclated from the values above */

Typo?


-- 
ldv

From ldv at altlinux.org  Fri Aug  7 18:53:54 2020
From: ldv at altlinux.org (Dmitry V. Levin)
Date: Fri, 7 Aug 2020 21:53:54 +0300
Subject: [PATCH v6 3/5] Use get_proc_pid for /proc paths
In-Reply-To: <20200806190211.118721-4-uzonyi.akos@gmail.com>
References: <20200806190211.118721-1-uzonyi.akos@gmail.com>
 <20200806190211.118721-4-uzonyi.akos@gmail.com>
Message-ID: <20200807185354.GB5985@altlinux.org>

On Thu, Aug 06, 2020 at 09:02:09PM +0200, ?kos Uzonyi wrote:
> * mmap_cache.c (mmap_cache_rebuild_if_invalid): Use proc pid instead of
> tcp->pid for /proc path.
> * util.c (getfdproto): Likewise.
> (pidfd_get_pid): Likewise.
> * pathtrace.c (getfdpath_pid): Likewise.
> * strace.c (attach_tcb): Likewise.
> ---
>  mmap_cache.c | 2 +-
>  pathtrace.c  | 5 ++++-
>  strace.c     | 2 +-
>  util.c       | 7 +++++--
>  4 files changed, 11 insertions(+), 5 deletions(-)
> 
> diff --git a/mmap_cache.c b/mmap_cache.c
> index 89c62254..9825df26 100644
> --- a/mmap_cache.c
> +++ b/mmap_cache.c
> @@ -84,7 +84,7 @@ mmap_cache_rebuild_if_invalid(struct tcb *tcp, const char *caller)
>  		return MMAP_CACHE_REBUILD_READY;
>  
>  	char filename[sizeof("/proc/4294967296/maps")];
> -	xsprintf(filename, "/proc/%u/maps", tcp->pid);
> +	xsprintf(filename, "/proc/%u/maps", get_proc_pid(tcp));
>  
>  	FILE *fp = fopen_stream(filename, "r");
>  	if (!fp) {
> diff --git a/pathtrace.c b/pathtrace.c
> index 5b60762b..74717a8a 100644
> --- a/pathtrace.c
> +++ b/pathtrace.c
> @@ -87,7 +87,10 @@ getfdpath_pid(pid_t pid, int fd, char *buf, unsigned bufsize)
>  	if (fd < 0)
>  		return -1;
>  
> -	xsprintf(linkpath, "/proc/%u/fd/%u", pid, fd);
> +	int proc_pid = 0;
> +	translate_pid(NULL, pid, PT_TID, &proc_pid);
> +
> +	xsprintf(linkpath, "/proc/%u/fd/%u", proc_pid, fd);

This looks like an emulation of get_proc_pid(tcp) for the case
when we have no tcp.

Fortunately, we have a tcp argument, it's in function getfdpath.
Since there are no users of getfdpath_pid that couldn't use getfdpath
instead, I suggest removing getfdpath_pid and defining just getfdpath,
this would make the code clearer.

>  	n = readlink(linkpath, buf, bufsize - 1);
>  	/*
>  	 * NB: if buf is too small, readlink doesn't fail,
> diff --git a/util.c b/util.c
> index 094e5818..d87d022e 100644
> --- a/util.c
> +++ b/util.c
> @@ -582,8 +582,11 @@ printdev(struct tcb *tcp, int fd, const char *path)
>  pid_t
>  pidfd_get_pid(pid_t pid_of_fd, int fd)
>  {
> +	int proc_pid = 0;
> +	translate_pid(NULL, pid_of_fd, PT_TID, &proc_pid);
> +
>  	char fdi_path[sizeof("/proc/%u/fdinfo/%u") + 2 * sizeof(int) * 3];
> -	xsprintf(fdi_path, "/proc/%u/fdinfo/%u", pid_of_fd, fd);
> +	xsprintf(fdi_path, "/proc/%u/fdinfo/%u", proc_pid, fd);
>  
>  	FILE *f = fopen_stream(fdi_path, "r");
>  	if (!f)

Likewise, this would invoke the whole translate_pid machinery even for the
case when is_proc_ours() returns true.  Could something be done about it?

The idea is not to bring all these heavy translation mechanisms up
unnecessarily, that is, unless /proc is messed up or --pidns-translation
is specified.


-- 
ldv

From ldv at altlinux.org  Fri Aug  7 19:04:04 2020
From: ldv at altlinux.org (Dmitry V. Levin)
Date: Fri, 7 Aug 2020 22:04:04 +0300
Subject: [PATCH v6 1/5] PID namespace translation support
In-Reply-To: <20200806190211.118721-2-uzonyi.akos@gmail.com>
References: <20200806190211.118721-1-uzonyi.akos@gmail.com>
 <20200806190211.118721-2-uzonyi.akos@gmail.com>
Message-ID: <20200807190404.GC5985@altlinux.org>

On Thu, Aug 06, 2020 at 09:02:07PM +0200, ?kos Uzonyi wrote:
> * pidns.c: New file.
> * trie.c: New file.
> * trie.h: New file.

Sorry, these files are really hard to review, especially trie.c:
when I read it for about five minutes my mind blows up.

So I'll be reviewing these products of a superiour mind
in five minute chunks, sorry.


-- 
ldv

From ldv at altlinux.org  Fri Aug  7 19:09:25 2020
From: ldv at altlinux.org (Dmitry V. Levin)
Date: Fri, 7 Aug 2020 22:09:25 +0300
Subject: [PATCH v6 5/5] Add tests for PID namespace translation
In-Reply-To: <20200806190211.118721-6-uzonyi.akos@gmail.com>
References: <20200806190211.118721-1-uzonyi.akos@gmail.com>
 <20200806190211.118721-6-uzonyi.akos@gmail.com>
Message-ID: <20200807190925.GD5985@altlinux.org>

On Thu, Aug 06, 2020 at 09:02:11PM +0200, ?kos Uzonyi wrote:
>  tests/gettid--pidns-translation.c             |  2 +

Note that this test is constantly failing one of github ci tests,
see e.g. https://github.com/strace/strace/runs/959422499

Could you have a look, please?


-- 
ldv

From uzonyi.akos at gmail.com  Fri Aug  7 19:12:05 2020
From: uzonyi.akos at gmail.com (=?UTF-8?B?w4Frb3MgVXpvbnlp?=)
Date: Fri, 7 Aug 2020 21:12:05 +0200
Subject: [PATCH v6 3/5] Use get_proc_pid for /proc paths
In-Reply-To: <20200807185354.GB5985@altlinux.org>
References: <20200806190211.118721-1-uzonyi.akos@gmail.com>
 <20200806190211.118721-4-uzonyi.akos@gmail.com>
 <20200807185354.GB5985@altlinux.org>
Message-ID: <CAJrAtOUvVuJN3LEagY=PFv9AgFFgQ-5OvB2_2R40cmaZbO56tg@mail.gmail.com>

On Fri, 7 Aug 2020 at 20:53, Dmitry V. Levin <ldv at altlinux.org> wrote:
> On Thu, Aug 06, 2020 at 09:02:09PM +0200, ?kos Uzonyi wrote:
> > * mmap_cache.c (mmap_cache_rebuild_if_invalid): Use proc pid instead of
> > tcp->pid for /proc path.
> > * util.c (getfdproto): Likewise.
> > (pidfd_get_pid): Likewise.
> > * pathtrace.c (getfdpath_pid): Likewise.
> > * strace.c (attach_tcb): Likewise.
> > ---
> >  mmap_cache.c | 2 +-
> >  pathtrace.c  | 5 ++++-
> >  strace.c     | 2 +-
> >  util.c       | 7 +++++--
> >  4 files changed, 11 insertions(+), 5 deletions(-)
> >
> > diff --git a/mmap_cache.c b/mmap_cache.c
> > index 89c62254..9825df26 100644
> > --- a/mmap_cache.c
> > +++ b/mmap_cache.c
> > @@ -84,7 +84,7 @@ mmap_cache_rebuild_if_invalid(struct tcb *tcp, const char *caller)
> >               return MMAP_CACHE_REBUILD_READY;
> >
> >       char filename[sizeof("/proc/4294967296/maps")];
> > -     xsprintf(filename, "/proc/%u/maps", tcp->pid);
> > +     xsprintf(filename, "/proc/%u/maps", get_proc_pid(tcp));
> >
> >       FILE *fp = fopen_stream(filename, "r");
> >       if (!fp) {
> > diff --git a/pathtrace.c b/pathtrace.c
> > index 5b60762b..74717a8a 100644
> > --- a/pathtrace.c
> > +++ b/pathtrace.c
> > @@ -87,7 +87,10 @@ getfdpath_pid(pid_t pid, int fd, char *buf, unsigned bufsize)
> >       if (fd < 0)
> >               return -1;
> >
> > -     xsprintf(linkpath, "/proc/%u/fd/%u", pid, fd);
> > +     int proc_pid = 0;
> > +     translate_pid(NULL, pid, PT_TID, &proc_pid);
> > +
> > +     xsprintf(linkpath, "/proc/%u/fd/%u", proc_pid, fd);
>
> This looks like an emulation of get_proc_pid(tcp) for the case
> when we have no tcp.
>
> Fortunately, we have a tcp argument, it's in function getfdpath.
> Since there are no users of getfdpath_pid that couldn't use getfdpath
> instead, I suggest removing getfdpath_pid and defining just getfdpath,
> this would make the code clearer.

getfdpath_pid was introduced by me recently. It's used in printfd_pid
(util.c), and it cannot be replaced by getfdpath. getfdpath_pid is
necessary for decoding a fd of another process (not the tracee), which
is the case in kcmp.

> >       n = readlink(linkpath, buf, bufsize - 1);
> >       /*
> >        * NB: if buf is too small, readlink doesn't fail,
> > diff --git a/util.c b/util.c
> > index 094e5818..d87d022e 100644
> > --- a/util.c
> > +++ b/util.c
> > @@ -582,8 +582,11 @@ printdev(struct tcb *tcp, int fd, const char *path)
> >  pid_t
> >  pidfd_get_pid(pid_t pid_of_fd, int fd)
> >  {
> > +     int proc_pid = 0;
> > +     translate_pid(NULL, pid_of_fd, PT_TID, &proc_pid);
> > +
> >       char fdi_path[sizeof("/proc/%u/fdinfo/%u") + 2 * sizeof(int) * 3];
> > -     xsprintf(fdi_path, "/proc/%u/fdinfo/%u", pid_of_fd, fd);
> > +     xsprintf(fdi_path, "/proc/%u/fdinfo/%u", proc_pid, fd);
> >
> >       FILE *f = fopen_stream(fdi_path, "r");
> >       if (!f)
>
> Likewise, this would invoke the whole translate_pid machinery even for the
> case when is_proc_ours() returns true.  Could something be done about it?
>
> The idea is not to bring all these heavy translation mechanisms up
> unnecessarily, that is, unless /proc is messed up or --pidns-translation
> is specified.

Actually, translation happens very fast in that case, as the following
condition will be true (in translate_pid):

/* If translation is trivial */
if (tip.from_ns == our_ns && (is_proc_ours() || !proc_pid_ptr)) {

So we could even remove the "if (is_proc_ours())" optimization from
get_proc_pid, as it is already done in translate_pid.

From ldv at altlinux.org  Fri Aug  7 19:29:38 2020
From: ldv at altlinux.org (Dmitry V. Levin)
Date: Fri, 7 Aug 2020 22:29:38 +0300
Subject: [PATCH v6 3/5] Use get_proc_pid for /proc paths
In-Reply-To: <CAJrAtOUvVuJN3LEagY=PFv9AgFFgQ-5OvB2_2R40cmaZbO56tg@mail.gmail.com>
References: <20200806190211.118721-1-uzonyi.akos@gmail.com>
 <20200806190211.118721-4-uzonyi.akos@gmail.com>
 <20200807185354.GB5985@altlinux.org>
 <CAJrAtOUvVuJN3LEagY=PFv9AgFFgQ-5OvB2_2R40cmaZbO56tg@mail.gmail.com>
Message-ID: <20200807192938.GE5985@altlinux.org>

On Fri, Aug 07, 2020 at 09:12:05PM +0200, ?kos Uzonyi wrote:
> On Fri, 7 Aug 2020 at 20:53, Dmitry V. Levin <ldv at altlinux.org> wrote:
> > On Thu, Aug 06, 2020 at 09:02:09PM +0200, ?kos Uzonyi wrote:
> > > * mmap_cache.c (mmap_cache_rebuild_if_invalid): Use proc pid instead of
> > > tcp->pid for /proc path.
> > > * util.c (getfdproto): Likewise.
> > > (pidfd_get_pid): Likewise.
> > > * pathtrace.c (getfdpath_pid): Likewise.
> > > * strace.c (attach_tcb): Likewise.
> > > ---
> > >  mmap_cache.c | 2 +-
> > >  pathtrace.c  | 5 ++++-
> > >  strace.c     | 2 +-
> > >  util.c       | 7 +++++--
> > >  4 files changed, 11 insertions(+), 5 deletions(-)
> > >
> > > diff --git a/mmap_cache.c b/mmap_cache.c
> > > index 89c62254..9825df26 100644
> > > --- a/mmap_cache.c
> > > +++ b/mmap_cache.c
> > > @@ -84,7 +84,7 @@ mmap_cache_rebuild_if_invalid(struct tcb *tcp, const char *caller)
> > >               return MMAP_CACHE_REBUILD_READY;
> > >
> > >       char filename[sizeof("/proc/4294967296/maps")];
> > > -     xsprintf(filename, "/proc/%u/maps", tcp->pid);
> > > +     xsprintf(filename, "/proc/%u/maps", get_proc_pid(tcp));
> > >
> > >       FILE *fp = fopen_stream(filename, "r");
> > >       if (!fp) {
> > > diff --git a/pathtrace.c b/pathtrace.c
> > > index 5b60762b..74717a8a 100644
> > > --- a/pathtrace.c
> > > +++ b/pathtrace.c
> > > @@ -87,7 +87,10 @@ getfdpath_pid(pid_t pid, int fd, char *buf, unsigned bufsize)
> > >       if (fd < 0)
> > >               return -1;
> > >
> > > -     xsprintf(linkpath, "/proc/%u/fd/%u", pid, fd);
> > > +     int proc_pid = 0;
> > > +     translate_pid(NULL, pid, PT_TID, &proc_pid);
> > > +
> > > +     xsprintf(linkpath, "/proc/%u/fd/%u", proc_pid, fd);
> >
> > This looks like an emulation of get_proc_pid(tcp) for the case
> > when we have no tcp.
> >
> > Fortunately, we have a tcp argument, it's in function getfdpath.
> > Since there are no users of getfdpath_pid that couldn't use getfdpath
> > instead, I suggest removing getfdpath_pid and defining just getfdpath,
> > this would make the code clearer.
> 
> getfdpath_pid was introduced by me recently. It's used in printfd_pid
> (util.c), and it cannot be replaced by getfdpath. getfdpath_pid is
> necessary for decoding a fd of another process (not the tracee), which
> is the case in kcmp.

Indeed, I used to remember that, but it has eventually slipped my mind.
> 
> > >       n = readlink(linkpath, buf, bufsize - 1);
> > >       /*
> > >        * NB: if buf is too small, readlink doesn't fail,
> > > diff --git a/util.c b/util.c
> > > index 094e5818..d87d022e 100644
> > > --- a/util.c
> > > +++ b/util.c
> > > @@ -582,8 +582,11 @@ printdev(struct tcb *tcp, int fd, const char *path)
> > >  pid_t
> > >  pidfd_get_pid(pid_t pid_of_fd, int fd)
> > >  {
> > > +     int proc_pid = 0;
> > > +     translate_pid(NULL, pid_of_fd, PT_TID, &proc_pid);
> > > +
> > >       char fdi_path[sizeof("/proc/%u/fdinfo/%u") + 2 * sizeof(int) * 3];
> > > -     xsprintf(fdi_path, "/proc/%u/fdinfo/%u", pid_of_fd, fd);
> > > +     xsprintf(fdi_path, "/proc/%u/fdinfo/%u", proc_pid, fd);
> > >
> > >       FILE *f = fopen_stream(fdi_path, "r");
> > >       if (!f)
> >
> > Likewise, this would invoke the whole translate_pid machinery even for the
> > case when is_proc_ours() returns true.  Could something be done about it?
> >
> > The idea is not to bring all these heavy translation mechanisms up
> > unnecessarily, that is, unless /proc is messed up or --pidns-translation
> > is specified.
> 
> Actually, translation happens very fast in that case, as the following
> condition will be true (in translate_pid):
> 
> /* If translation is trivial */
> if (tip.from_ns == our_ns && (is_proc_ours() || !proc_pid_ptr)) {
> 
> So we could even remove the "if (is_proc_ours())" optimization from
> get_proc_pid, as it is already done in translate_pid.

Sorry, I don't follow: translate_pid(NULL) calls both get_our_ns()
and is_proc_ours(), but I don't understand why it has to call
get_our_ns() if the result is essentially ignored anyway.


-- 
ldv

From uzonyi.akos at gmail.com  Fri Aug  7 19:34:22 2020
From: uzonyi.akos at gmail.com (=?UTF-8?B?w4Frb3MgVXpvbnlp?=)
Date: Fri, 7 Aug 2020 21:34:22 +0200
Subject: [PATCH v6 1/5] PID namespace translation support
In-Reply-To: <20200807182318.GA5985@altlinux.org>
References: <20200806190211.118721-1-uzonyi.akos@gmail.com>
 <20200806190211.118721-2-uzonyi.akos@gmail.com>
 <20200807182318.GA5985@altlinux.org>
Message-ID: <CAJrAtOWjsaeMxUYgnHoqVXXfcZL1_X7QTCCQM80JEyDVwNTieg@mail.gmail.com>

On Fri, 7 Aug 2020 at 20:23, Dmitry V. Levin <ldv at altlinux.org> wrote:
> On Thu, Aug 06, 2020 at 09:02:07PM +0200, ?kos Uzonyi wrote:
> [...]
> > diff --git a/NEWS b/NEWS
> > index b83f9e80..9086fde9 100644
> > --- a/NEWS
> > +++ b/NEWS
> > @@ -14,6 +14,7 @@ Noteworthy changes in release ?.? (????-??-??)
> >      KEYCTL_*, KVM_*, LOOP_*, NDA_*, RTC_*, TCA_*, STATX_*, and *_MAGIC
> >      constants.
> >    * Updated lists of ioctl commands from Linux 5.8.
> > +  * Added --pidns-translation opition for PID namespace translation.
>
> Typo?
>
> > @@ -983,6 +1005,27 @@ print_local_array_ex(struct tcb *tcp,
> >  extern kernel_ulong_t *
> >  fetch_indirect_syscall_args(struct tcb *, kernel_ulong_t addr, unsigned int n_args);
> >
> > +extern void pidns_init(void);
> > +
> > +/**
> > + * Returns the pid of the tracee as present in /proc (can be different from
> > + * tcp->pid if /proc and the tracee process are in different PID namespaces).
> > + */
> > +extern int get_proc_pid(struct tcb *);
>
> I'm still puzzled what /proc are you talking about, the tracer's /proc or
> the tracee's /proc.

It's the tracer's /proc. I will clarify it.

> > @@ -1058,6 +1101,14 @@ printfd(struct tcb *tcp, int fd)
> >   * of the tracee the descriptor tcp).  This is a stub.
> >   */
> >  extern void printfd_pid_tracee_ns(struct tcb *tcp, pid_t pid, int fd);
> > +
> > +extern void printpid(struct tcb *, int pid, enum pid_type type);
>
> Although this might look obvious, I suggest adding a short comment for
> printpid, too, to make it clear that printpid prints the pid given
> in the tracee's pid namespace.

Ok, I'll add a short comment.

> > +/**
> > + * Key:   Proc PID
> > + * Value: stuct proc_data
>
> Typo?
>
> > +/**
> > + * Helper function for creating a trie.
> > + *
> > + * For node_key_bits and data_block_key_bits 4 is used (so trie height is 32 / 4
> > + * = 8, and node sizes are 8 byte * 2^4 = 128 bytes), which seems to be a good
> > + * tradeoff between between memory usage and lookup time. It should not be too
>
> Typo?
>
> > + * large, since there can be large holes between PIDs, and it would be just a
> > + * waste of memory having large nodes with lot of NULL pointers in them.
> > + */
> > +static struct trie *
> > +create_trie_4(uint8_t key_size, uint8_t item_size_lg, uint64_t empty_value)
> > +{
> > +     struct trie *t = trie_create(key_size, item_size_lg, 4, 4, empty_value);
> > +     if (!t)
> > +             error_msg_and_die("creating trie failed");
> > +
> > +     return t;
> > +}
>
> I believe empty_value is always 0, so why bother with the argument?

I'm working on a performance improvement: translating pids by unix
sockets. In that code I use a trie where empty_value is -1 (keys are
file descriptors), so I would like to keep that argument.

> > +     while (p) {
> > +             errno = 0;
> > +             long id = strtol(p, NULL, 10);
> > +
> > +             if (errno || (id < 1) || (id > INT_MAX)) {
>
> I don't think these extra brackets increase readability.

Agree.

> > +                     perror_func_msg("converting pid to int");
> > +                     break;
> > +             }
>
> I suggest also printing the value of p in this unlikely case.

OK.

> > +/**
> > + * Returns whether the /proc filesystem's PID namespace is same as strace's.
>
> Grammar: is the same.
>
> > diff --git a/strace.1.in b/strace.1.in
> > index 3b21caec..adca194c 100644
> > --- a/strace.1.in
> > +++ b/strace.1.in
> > @@ -1075,6 +1075,10 @@ Print all available information associated with file descritors:
> >  protocol-specific information associated with socket file descriptors,
> >  block/character device number associated with device file descriptors,
> >  and PIDs asociated with pidfd file descriptors.
> > +.TP
> > +.B \-\-pidns\-translation
> > +If strace and tracee are in different PID namespaces, print PIDs in
> > +strace's namespace also.
>
> Changing "print PIDs in strace's namespace also" to either
> "print PIDs also in strace's namespace" or
> "print PIDs in strace's namespace, too" would likely result
> to a more grammatically correct sentence.
>
> > diff --git a/trie.c b/trie.c
> > new file mode 100644
> > index 00000000..76cecc25
> > --- /dev/null
> > +++ b/trie.c
> > @@ -0,0 +1,250 @@
> > +/*
> > + * Simple trie implementation for key-value mapping storage
> > + *
> > + * Copyright (c) 2020 ?kos Uzonyi <uzonyi.akos at gmail.com>
> > + * All rights reserved.
> > + *
> > + * SPDX-License-Identifier: LGPL-2.1-or-later
> > + */
> > +
> > +#include "defs.h"
> > +
> > +#include <assert.h>
>
> Does this code use assert?

Indeed, it's not necessary anymore.

> > +#include <stdbool.h>
> > +#include <stdint.h>
> > +#include <stdlib.h>
> > +
> > +#include "trie.h"
> > +
> > +static const uint8_t ptr_sz_lg = (sizeof(uint64_t *) == 8 ? 6 : 5);
>
> Hmm, pidns.c uses a slightly different (although essentially the same)
> definition of ptr_sz_lg.

Oh thanks, I modified the one in pidns.c recently, and forgot to
update this one.

> > +
> > +/**
> > + * Returns lg2 of node size for the specific level of the trie. If max_depth
> > + * provided is less than zero, it is calculated via trie_get_depth call.
> > + */
> > +static uint8_t
> > +trie_get_node_size(struct trie *t, uint8_t depth)
>
> What do you mean by "If max_depth provided"?

Sorry, I forgot to update the documentation when I removed the
"max_depth" argument.

> > +struct trie *
> > +trie_create(uint8_t key_size, uint8_t item_size_lg, uint8_t node_key_bits,
> > +            uint8_t data_block_key_bits, uint64_t empty_value)
> > +{
> > +     if (item_size_lg > 6)
> > +             return NULL;
> > +     if (key_size > 64)
> > +             return NULL;
> > +     if (node_key_bits < 1)
> > +             return NULL;
> > +     if (data_block_key_bits < 1 || data_block_key_bits > key_size)
> > +             return NULL;
>
> Should there be a check that node_key_bits isn't too big, for consistency?

Actually it's not a problem if node_key_bits is big. If node_key_bits
is larger than key_size, then all the key bits (except the bits for
the data block) are part of the "<remainder>" node level.

> > +static uint64_t
> > +trie_iterate_keys_node(struct trie *t,
> > +                       trie_iterate_fn fn, void *fn_data,
> > +                       void *node, uint64_t start, uint64_t end,
> > +                       uint8_t depth)
> > +{
> > +     if (start > end || !node)
> > +             return 0;
> > +
> > +     if (depth == t->max_depth) {
> > +             for (uint64_t i = start; i <= end; i++)
> > +                     fn(fn_data, i, trie_data_block_get(t,
> > +                             (uint64_t *) node, i));
> > +
> > +             return end - start + 1; //TODO: overflow
>
> Overflow?

The function returns the number of values iterated. In case the trie
contains 2^64 values, the above expression will overflow to 0. But
since it's not possible to have so many values in the trie, I agree
that this comment should be removed. :)

> > +     /**
> > +      * Number of bits in key that makes a symbol for a node.
> > +      * (equals to log2 of the child count of the node)
> > +      */
> > +     uint8_t node_key_bits;
> > +
> > +     /**
> > +      * Number of bits in key that make a symbol for the data block (leaf).
>
> Typo?

Sorry I can't find the typo you are referring to.

> > +      * (equals to log2 of the value count stored in a data block)
> > +      */
> > +     uint8_t data_block_key_bits;
> > +
> > +     /** The depth of the data block. Caluclated from the values above */
>
> Typo?

Thanks, I'll fix all the typos you found. I think I should have run a
spell checker on the comments, sorry.

From ldv at altlinux.org  Fri Aug  7 19:43:24 2020
From: ldv at altlinux.org (Dmitry V. Levin)
Date: Fri, 7 Aug 2020 22:43:24 +0300
Subject: [PATCH v6 2/5] Use printpid in decoders
In-Reply-To: <20200806190211.118721-3-uzonyi.akos@gmail.com>
References: <20200806190211.118721-1-uzonyi.akos@gmail.com>
 <20200806190211.118721-3-uzonyi.akos@gmail.com>
Message-ID: <20200807194324.GA7365@altlinux.org>

On Thu, Aug 06, 2020 at 09:02:08PM +0200, ?kos Uzonyi wrote:
> * getpid.c: New file.
> * Makefile.am (libstrace_a_SOURCES): Add getpid.c.

By the way, you can use a simpler form "Add it" instead of "Add getpid.c".

> diff --git a/get_robust_list.c b/get_robust_list.c
> index b5aebaff..4b771bac 100644
> --- a/get_robust_list.c
> +++ b/get_robust_list.c
> @@ -10,7 +10,8 @@
>  SYS_FUNC(get_robust_list)
>  {
>  	if (entering(tcp)) {
> -		tprintf("%d, ", (int) tcp->u_arg[0]);
> +		printpid(tcp, (int) tcp->u_arg[0], PT_TID);
> +		tprints(", ");

The explicit cast used to be need for tprintf, but I don't think
it's still useful in printpid calls like this one.

> diff --git a/ioprio.c b/ioprio.c
> index 873c8ce5..52144884 100644
> --- a/ioprio.c
> +++ b/ioprio.c
> @@ -49,13 +49,30 @@ print_ioprio(unsigned int ioprio)
>  		? tprints_comment : tprints)(str);
>  }
>  
> +static void
> +ioprio_print_who(struct tcb *tcp, int which, int who)
> +{
> +	switch (which)
> +	{
> +	case IOPRIO_WHO_PROCESS:
> +		printpid(tcp, who, PT_TGID);
> +		break;
> +	case IOPRIO_WHO_PGRP:
> +		printpid(tcp, who, PT_PGID);
> +		break;
> +	default:
> +		tprintf("%d", who);
> +		break;
> +	}
> +}
> +
>  SYS_FUNC(ioprio_get)
>  {
>  	if (entering(tcp)) {
>  		/* int which */
>  		printxval(ioprio_who, tcp->u_arg[0], "IOPRIO_WHO_???");
> -		/* int who */
> -		tprintf(", %d", (int) tcp->u_arg[1]);
> +		tprints(", ");
> +		ioprio_print_who(tcp, (int) tcp->u_arg[0], (int) tcp->u_arg[1]);

Likewise, I don't think these explicit casts increase readability.

>  		return 0;
>  	} else {
>  		if (syserror(tcp))
> @@ -72,8 +89,9 @@ SYS_FUNC(ioprio_set)
>  {
>  	/* int which */
>  	printxval(ioprio_who, tcp->u_arg[0], "IOPRIO_WHO_???");
> -	/* int who */
> -	tprintf(", %d, ", (int) tcp->u_arg[1]);
> +	tprints(", ");
> +	ioprio_print_who(tcp, (int) tcp->u_arg[0], (int) tcp->u_arg[1]);
> +	tprints(", ");

Likewise.

> diff --git a/ipc_shmctl.c b/ipc_shmctl.c
> index 8c9e1e7a..71b41651 100644
> --- a/ipc_shmctl.c
> +++ b/ipc_shmctl.c
> @@ -12,6 +12,7 @@
>   */
>  
>  #include "defs.h"
> +#include "print_fields.h"
>  
>  #include DEF_MPERS_TYPE(shmid_ds_t)
>  
> @@ -53,8 +54,8 @@ print_shmid_ds(struct tcb *const tcp, const kernel_ulong_t addr, int cmd)
>  		PRINT_FIELD_UID(", ", shmid_ds.shm_perm, cgid);
>  		tprints("}");
>  		tprintf(", shm_segsz=%u", (unsigned) shmid_ds.shm_segsz);
> -		PRINT_FIELD_D(", ", shmid_ds, shm_cpid);
> -		PRINT_FIELD_D(", ", shmid_ds, shm_lpid);
> +		PRINT_FIELD_TGID(", ", shmid_ds, shm_cpid, tcp);
> +		PRINT_FIELD_TGID(", ", shmid_ds, shm_lpid, tcp);
>  		tprintf(", shm_nattch=%u", (unsigned) shmid_ds.shm_nattch);
>  		tprintf(", shm_atime=%u", (unsigned) shmid_ds.shm_atime);
>  		tprintf(", shm_dtime=%u", (unsigned) shmid_ds.shm_dtime);

The #include "print_fields.h" added here is probably a leftover from an
early edition.

> diff --git a/numa.c b/numa.c
> index cc7a7cc6..37b95397 100644
> --- a/numa.c
> +++ b/numa.c
> @@ -44,7 +44,8 @@ print_nodemask(struct tcb *const tcp, const kernel_ulong_t addr,
>  
>  SYS_FUNC(migrate_pages)
>  {
> -	tprintf("%d, %" PRI_klu ", ", (int) tcp->u_arg[0], tcp->u_arg[1]);
> +	printpid(tcp, (int) tcp->u_arg[0], PT_TGID);
> +	tprintf(", %" PRI_klu ", ", tcp->u_arg[1]);

Likewise, I don't think this explicit cast increases readability.

>  	print_nodemask(tcp, tcp->u_arg[2], tcp->u_arg[1]);
>  	tprints(", ");
>  	print_nodemask(tcp, tcp->u_arg[3], tcp->u_arg[1]);
> @@ -170,7 +171,8 @@ SYS_FUNC(move_pages)
>  	kernel_ulong_t buf;
>  
>  	if (entering(tcp)) {
> -		tprintf("%d, %" PRI_klu ", ", (int) tcp->u_arg[0], npages);
> +		printpid(tcp, (int) tcp->u_arg[0], PT_TGID);
> +		tprintf(", %" PRI_klu ", ", npages);

Likewise.

> diff --git a/pidfd_open.c b/pidfd_open.c
> index bbc7f617..10b5003d 100644
> --- a/pidfd_open.c
> +++ b/pidfd_open.c
> @@ -10,7 +10,7 @@
>  SYS_FUNC(pidfd_open)
>  {
>  	/* pid_t pid */
> -	tprintf("%d", (int) tcp->u_arg[0]);
> +	printpid(tcp, (int) tcp->u_arg[0], PT_TGID);

Likewise.

> diff --git a/process_vm.c b/process_vm.c
> index abee1e68..50acb3fd 100644
> --- a/process_vm.c
> +++ b/process_vm.c
> @@ -13,7 +13,8 @@ SYS_FUNC(process_vm_readv)
>  {
>  	if (entering(tcp)) {
>  		/* arg 1: pid */
> -		tprintf("%d, ", (int) tcp->u_arg[0]);
> +		printpid(tcp, (int) tcp->u_arg[0], PT_TGID);
> +		tprints(", ");

Likewise.

>  	} else {
>  		kernel_ulong_t local_iovcnt = tcp->u_arg[2];
>  		kernel_ulong_t remote_iovcnt = tcp->u_arg[4];
> @@ -42,7 +43,8 @@ SYS_FUNC(process_vm_writev)
>  	kernel_ulong_t flags = tcp->u_arg[5];
>  
>  	/* arg 1: pid */
> -	tprintf("%d, ", (int) tcp->u_arg[0]);
> +	printpid(tcp, (int) tcp->u_arg[0], PT_TGID);
> +	tprints(", ");

Likewise.

> diff --git a/resource.c b/resource.c
> index 53192ee9..bd21b748 100644
> --- a/resource.c
> +++ b/resource.c
> @@ -142,7 +142,8 @@ SYS_FUNC(setrlimit)
>  SYS_FUNC(prlimit64)
>  {
>  	if (entering(tcp)) {
> -		tprintf("%d, ", (int) tcp->u_arg[0]);
> +		printpid(tcp, (int) tcp->u_arg[0], PT_TGID);
> +		tprints(", ");

Likewise.

> diff --git a/sched.c b/sched.c
> index 788ef39b..7ae5abe2 100644
> --- a/sched.c
> +++ b/sched.c
> @@ -21,7 +21,7 @@
>  SYS_FUNC(sched_getscheduler)
>  {
>  	if (entering(tcp)) {
> -		tprintf("%d", (int) tcp->u_arg[0]);
> +		printpid(tcp, (int) tcp->u_arg[0], PT_TGID);

Likewise.

>  	} else if (!syserror(tcp)) {
>  		tcp->auxstr = xlookup(schedulers, (kernel_ulong_t) tcp->u_rval);
>  		return RVAL_STR;
> @@ -31,7 +31,8 @@ SYS_FUNC(sched_getscheduler)
>  
>  SYS_FUNC(sched_setscheduler)
>  {
> -	tprintf("%d, ", (int) tcp->u_arg[0]);
> +	printpid(tcp, (int) tcp->u_arg[0], PT_TGID);
> +	tprints(", ");

Likewise.

>  	printxval(schedulers, tcp->u_arg[1], "SCHED_???");
>  	tprints(", ");
>  	printnum_int(tcp, tcp->u_arg[2], "%d");
> @@ -41,16 +42,19 @@ SYS_FUNC(sched_setscheduler)
>  
>  SYS_FUNC(sched_getparam)
>  {
> -	if (entering(tcp))
> -		tprintf("%d, ", (int) tcp->u_arg[0]);
> -	else
> +	if (entering(tcp)) {
> +		printpid(tcp, (int) tcp->u_arg[0], PT_TGID);
> +		tprints(", ");
> +	} else {

Likewise.

>  		printnum_int(tcp, tcp->u_arg[1], "%d");
> +	}
>  	return 0;
>  }
>  
>  SYS_FUNC(sched_setparam)
>  {
> -	tprintf("%d, ", (int) tcp->u_arg[0]);
> +	printpid(tcp, (int) tcp->u_arg[0], PT_TGID);
> +	tprints(", ");

Likewise.

>  	printnum_int(tcp, tcp->u_arg[1], "%d");
>  
>  	return RVAL_DECODED;
> @@ -68,7 +72,8 @@ do_sched_rr_get_interval(struct tcb *const tcp,
>  			 const print_obj_by_addr_fn print_ts)
>  {
>  	if (entering(tcp)) {
> -		tprintf("%d, ", (int) tcp->u_arg[0]);
> +		printpid(tcp, (int) tcp->u_arg[0], PT_TGID);
> +		tprints(", ");

Likewise.

>  	} else {
>  		if (syserror(tcp))
>  			printaddr(tcp->u_arg[1]);
> @@ -160,7 +165,8 @@ end:
>  SYS_FUNC(sched_setattr)
>  {
>  	if (entering(tcp)) {
> -		tprintf("%d, ", (int) tcp->u_arg[0]);
> +		printpid(tcp, (int) tcp->u_arg[0], PT_TGID);
> +		tprints(", ");

Likewise.

>  		print_sched_attr(tcp, tcp->u_arg[1], 0);
>  	} else {
>  		struct sched_attr attr;
> @@ -179,7 +185,8 @@ SYS_FUNC(sched_setattr)
>  SYS_FUNC(sched_getattr)
>  {
>  	if (entering(tcp)) {
> -		tprintf("%d, ", (int) tcp->u_arg[0]);
> +		printpid(tcp, (int) tcp->u_arg[0], PT_TGID);

Likewise.

> @@ -448,7 +449,7 @@ SYS_FUNC(kill)
>  
>  SYS_FUNC(tkill)
>  {
> -	tprintf("%d", (int) tcp->u_arg[0]);
> +	printpid(tcp, (int) tcp->u_arg[0], PT_TID);

Likewise.

>  	tprints(", ");
>  	printsignal(tcp->u_arg[1]);
>  
> @@ -457,8 +458,12 @@ SYS_FUNC(tkill)
>  
>  SYS_FUNC(tgkill)
>  {
> -	/* tgid, tid */
> -	tprintf("%d, %d, ", (int) tcp->u_arg[0], (int) tcp->u_arg[1]);
> +	/* tgid */
> +	printpid(tcp, (int) tcp->u_arg[0], PT_TGID);
> +	tprints(", ");
> +	/* tid */
> +	printpid(tcp, (int) tcp->u_arg[1], PT_TID);
> +	tprints(", ");

Likewise.

>  	/* signal */
>  	printsignal(tcp->u_arg[2]);
>  
> @@ -624,7 +629,8 @@ print_sigqueueinfo(struct tcb *const tcp, const int sig,
>  
>  SYS_FUNC(rt_sigqueueinfo)
>  {
> -	tprintf("%d, ", (int) tcp->u_arg[0]);
> +	printpid(tcp, (int) tcp->u_arg[0], PT_TGID);
> +	tprints(", ");

Likewise.

>  	print_sigqueueinfo(tcp, tcp->u_arg[1], tcp->u_arg[2]);
>  
>  	return RVAL_DECODED;
> @@ -632,7 +638,10 @@ SYS_FUNC(rt_sigqueueinfo)
>  
>  SYS_FUNC(rt_tgsigqueueinfo)
>  {
> -	tprintf("%d, %d, ", (int) tcp->u_arg[0], (int) tcp->u_arg[1]);
> +	printpid(tcp, (int) tcp->u_arg[0], PT_TGID);
> +	tprints(", ");
> +	printpid(tcp, (int) tcp->u_arg[1], PT_TID);
> +	tprints(", ");

Likewise.


-- 
ldv

From ldv at altlinux.org  Fri Aug  7 19:53:36 2020
From: ldv at altlinux.org (Dmitry V. Levin)
Date: Fri, 7 Aug 2020 22:53:36 +0300
Subject: [PATCH v6 1/5] PID namespace translation support
In-Reply-To: <CAJrAtOWjsaeMxUYgnHoqVXXfcZL1_X7QTCCQM80JEyDVwNTieg@mail.gmail.com>
References: <20200806190211.118721-1-uzonyi.akos@gmail.com>
 <20200806190211.118721-2-uzonyi.akos@gmail.com>
 <20200807182318.GA5985@altlinux.org>
 <CAJrAtOWjsaeMxUYgnHoqVXXfcZL1_X7QTCCQM80JEyDVwNTieg@mail.gmail.com>
Message-ID: <20200807195336.GB7365@altlinux.org>

On Fri, Aug 07, 2020 at 09:34:22PM +0200, ?kos Uzonyi wrote:
> On Fri, 7 Aug 2020 at 20:23, Dmitry V. Levin <ldv at altlinux.org> wrote:
> > On Thu, Aug 06, 2020 at 09:02:07PM +0200, ?kos Uzonyi wrote:
[...]
> > > + * large, since there can be large holes between PIDs, and it would be just a
> > > + * waste of memory having large nodes with lot of NULL pointers in them.
> > > + */
> > > +static struct trie *
> > > +create_trie_4(uint8_t key_size, uint8_t item_size_lg, uint64_t empty_value)
> > > +{
> > > +     struct trie *t = trie_create(key_size, item_size_lg, 4, 4, empty_value);
> > > +     if (!t)
> > > +             error_msg_and_die("creating trie failed");
> > > +
> > > +     return t;
> > > +}
> >
> > I believe empty_value is always 0, so why bother with the argument?
> 
> I'm working on a performance improvement: translating pids by unix
> sockets. In that code I use a trie where empty_value is -1 (keys are
> file descriptors), so I would like to keep that argument.

OK

[...]
> > > +struct trie *
> > > +trie_create(uint8_t key_size, uint8_t item_size_lg, uint8_t node_key_bits,
> > > +            uint8_t data_block_key_bits, uint64_t empty_value)
> > > +{
> > > +     if (item_size_lg > 6)
> > > +             return NULL;
> > > +     if (key_size > 64)
> > > +             return NULL;
> > > +     if (node_key_bits < 1)
> > > +             return NULL;
> > > +     if (data_block_key_bits < 1 || data_block_key_bits > key_size)
> > > +             return NULL;
> >
> > Should there be a check that node_key_bits isn't too big, for consistency?
> 
> Actually it's not a problem if node_key_bits is big. If node_key_bits
> is larger than key_size, then all the key bits (except the bits for
> the data block) are part of the "<remainder>" node level.

Unless we care about integer overflows due to node_key_bits being too
large.  Well, this definitely can wait as we are not going to have such
large node_key_bits any time soon.

[...]
> > > +     /**
> > > +      * Number of bits in key that makes a symbol for a node.
> > > +      * (equals to log2 of the child count of the node)
> > > +      */
> > > +     uint8_t node_key_bits;
> > > +
> > > +     /**
> > > +      * Number of bits in key that make a symbol for the data block (leaf).
> >
> > Typo?
> 
> Sorry I can't find the typo you are referring to.

It's grammar than. :)

The first comments says: Number of bits in key that makes.
The second comments says: Number of bits in key that make.

By the way, it should be "in the key" in both cases.


-- 
ldv

From uzonyi.akos at gmail.com  Fri Aug  7 21:11:22 2020
From: uzonyi.akos at gmail.com (=?UTF-8?B?w4Frb3MgVXpvbnlp?=)
Date: Fri, 7 Aug 2020 23:11:22 +0200
Subject: [PATCH v6 3/5] Use get_proc_pid for /proc paths
In-Reply-To: <20200807192938.GE5985@altlinux.org>
References: <20200806190211.118721-1-uzonyi.akos@gmail.com>
 <20200806190211.118721-4-uzonyi.akos@gmail.com>
 <20200807185354.GB5985@altlinux.org>
 <CAJrAtOUvVuJN3LEagY=PFv9AgFFgQ-5OvB2_2R40cmaZbO56tg@mail.gmail.com>
 <20200807192938.GE5985@altlinux.org>
Message-ID: <CAJrAtOVtRQaCEfLqBvAw5U0m8SR1KJdZoxvW=hjfqmtu_dz3nQ@mail.gmail.com>

On Fri, 7 Aug 2020 at 21:29, Dmitry V. Levin <ldv at altlinux.org> wrote:
> On Fri, Aug 07, 2020 at 09:12:05PM +0200, ?kos Uzonyi wrote:
> > On Fri, 7 Aug 2020 at 20:53, Dmitry V. Levin <ldv at altlinux.org> wrote:
> > > On Thu, Aug 06, 2020 at 09:02:09PM +0200, ?kos Uzonyi wrote:
[...]
> > > > diff --git a/util.c b/util.c
> > > > index 094e5818..d87d022e 100644
> > > > --- a/util.c
> > > > +++ b/util.c
> > > > @@ -582,8 +582,11 @@ printdev(struct tcb *tcp, int fd, const char *path)
> > > >  pid_t
> > > >  pidfd_get_pid(pid_t pid_of_fd, int fd)
> > > >  {
> > > > +     int proc_pid = 0;
> > > > +     translate_pid(NULL, pid_of_fd, PT_TID, &proc_pid);
> > > > +
> > > >       char fdi_path[sizeof("/proc/%u/fdinfo/%u") + 2 * sizeof(int) * 3];
> > > > -     xsprintf(fdi_path, "/proc/%u/fdinfo/%u", pid_of_fd, fd);
> > > > +     xsprintf(fdi_path, "/proc/%u/fdinfo/%u", proc_pid, fd);
> > > >
> > > >       FILE *f = fopen_stream(fdi_path, "r");
> > > >       if (!f)
> > >
> > > Likewise, this would invoke the whole translate_pid machinery even for the
> > > case when is_proc_ours() returns true.  Could something be done about it?
> > >
> > > The idea is not to bring all these heavy translation mechanisms up
> > > unnecessarily, that is, unless /proc is messed up or --pidns-translation
> > > is specified.
> >
> > Actually, translation happens very fast in that case, as the following
> > condition will be true (in translate_pid):
> >
> > /* If translation is trivial */
> > if (tip.from_ns == our_ns && (is_proc_ours() || !proc_pid_ptr)) {
> >
> > So we could even remove the "if (is_proc_ours())" optimization from
> > get_proc_pid, as it is already done in translate_pid.
>
> Sorry, I don't follow: translate_pid(NULL) calls both get_our_ns()
> and is_proc_ours(), but I don't understand why it has to call
> get_our_ns() if the result is essentially ignored anyway.

Indeed, it calls get_our_ns, which is not needed if tcp is NULL. It's
not a very big performance problem however, as get_our_ns return value
is cached. But I'll modify translate_pid a bit, so get_our_ns is only
called if really needed.

From uzonyi.akos at gmail.com  Sat Aug  8 13:33:06 2020
From: uzonyi.akos at gmail.com (=?UTF-8?B?w4Frb3MgVXpvbnlp?=)
Date: Sat, 8 Aug 2020 15:33:06 +0200
Subject: [PATCH v6 5/5] Add tests for PID namespace translation
In-Reply-To: <20200807190925.GD5985@altlinux.org>
References: <20200806190211.118721-1-uzonyi.akos@gmail.com>
 <20200806190211.118721-6-uzonyi.akos@gmail.com>
 <20200807190925.GD5985@altlinux.org>
Message-ID: <CAJrAtOWRyrMQZAhWA2GiLqD2kvAtm3MX0akpMNpNYSRCRWrbLA@mail.gmail.com>

On Fri, 7 Aug 2020 at 21:09, Dmitry V. Levin <ldv at altlinux.org> wrote:
> On Thu, Aug 06, 2020 at 09:02:11PM +0200, ?kos Uzonyi wrote:
> >  tests/gettid--pidns-translation.c             |  2 +
>
> Note that this test is constantly failing one of github ci tests,
> see e.g. https://github.com/strace/strace/runs/959422499
>
> Could you have a look, please?

Unfortunately musl calls gettid in the child after fork. I think some
kind of hack has to be done here, like running uniq on the output.

From uzonyi.akos at gmail.com  Sat Aug  8 21:14:32 2020
From: uzonyi.akos at gmail.com (=?UTF-8?q?=C3=81kos=20Uzonyi?=)
Date: Sat,  8 Aug 2020 23:14:32 +0200
Subject: [PATCH v7 0/5] [PIDNS] Final
Message-ID: <20200808211437.469898-1-uzonyi.akos@gmail.com>

From: Uzonyi ?kos <uzonyi.akos at gmail.com>

In gettid--pidns-translation test I used uniq to filter out gettid calls made
by musl.

Changes in v7:
  - Run uniq on gettid--pidns-translation test output
  - Add comment to printpid
  - translate_id: do not call get_our_ns if not necessary
  - Remove unnecessary parentheses
  - Fix commit message of last commit (s/-Y/--pidns-translation/)
  - get_proc_pid: remove unnecessary optimization
  - trie.c: remove #include <assert.h>
  - Add clarification to get_proc_pid's comment
  - Fix typos
  - trie.c: ptr_sz_lg use void* in sizeof
  - trie_get_node_size: fix comment
  - trie.c: remove "TODO: overflow"
  - ipc_shmctl.c: remove duplicate #include "print_field.h"
Changes in v6:
  - Add function with documentation for creating tries
  - Do not use -1ULL as error indicator in tcb.pid_ns
  - Use unsigned int (instead of uint64_t) for NS IDs
  - Add constant for NS ID size.
  - Modify get_proc_pid a bit
  - Die if trie creation fails
Changes in v5:
  - Squash "Use printpid in *" commits
  - Makefile.am: move adding getpid.c to "Use printpid in decoders"
  - Remove pid_ns_inited field from struct tcb
  - strace.1.in: remove -Y flag
  - Use tprints instead of tprintf where possible
  - Make some global variables static
  - pidns_init: remove "inited" bool variable
  - Make printpid_translation static
  - tests/pidns.c: refactor a bit
  - check_ns_ioctl: fix error msg
  - defs.h: Move adding get_proc_pid to "PID namespace translation support"
  - Remove tcp paramter name from declarations
  - Update printfd_pid_tracee_ns documentation
  - Use named constants for trie_create arguments
  - Add documentation comments
  - Add printpid_tgid_pgid function
  - Delete get_pid_max function; use global variables instead
  - Refactor trie:
    - Move key_size argument
    - Remove support for TRIE_SET
    - Merge trie_create, trie_init, trie_check functions
    - trie_free_node: make static, fix "node" argument type
    - Add max_depth field
    - Reorder functions
    - Extract common parts of trie_get, trie_set
Changes in v4:
  - Skip tests if NS_* ioctl commands are not supported
  - Improve documentation in pidns.h
  - Use pipe for init process termination (instead of SIGKILL)
  - Add PIDNS_TEST_INIT macro
  - Remove "ifdef __NR_gettid"
  - Fix fork--pidns-tranlsation.test: skip if unshare fails with EPERM
  - Use debug message instead of normal message in some cases
  - Rename some labels
  - Rewrite get_ns function
  - Remove O_NONBLOCK from open(/proc/<pid>/ns/pid)
Changes in v3:
  - Split accidentally sqashed last commit
  - Undo modification of tests/pidfd_send_signal.c
  - Rename kcmp-yY test to kcmp-y--pidns-translation
  - Skip tests if unshare fails with EPERM
  - Fix buffer size in pidns_pid2str
  - Use largefile_wrappers.h macros
  - Return early if from_ns or our_ns is 0
  - Do not call ioctl(NS_GET_PARENT) again, if first failed with ENOTTY
  - Skip pidns tests if Linux kernel version < 4.9
  - Use smaller trie nodes in pidns.c
  - Remove race condition from fork--pidns-translation test
  - Move "key_size" to center in trie description
  - Use PT_TID (not PT_TGID) when translating tcp->pid
  - Fix get_ns_hierarchy and get_id_list functions
  - Fix migrate_pages test if syscall succeds
  - Fix filtering in ioctl_block--pidns-translation.test
  - Fix -a flag value in xetpriority test
Changes in v2:
  - Add missing header files to Makefile
  - Fix pointer-to-int-cast errors
  - Fix unused-result errors
  - Use perror_msg instead of perror_func_msg where appropriate
  - Remove tcb parameter of read_int_from_file
  - Use xsprintf instead of snprintf
  - Refactor get_pid_max, get_ns_hierarchy, get_id_list functions
  - Remove -Y flag
  - Improve documentation of trie
  - Fix printing of f_owner_ex struct
  - Use printpid for F_GETOWN, F_SETOWN fcntl command arguments
  - Use printpid for shmid_ds.shm_cpid, shmid_ds.shm_clid
  - Call pidns_init before parsing arguments

?kos Uzonyi (5):
  PID namespace translation support
  Use printpid in decoders
  Use get_proc_pid for /proc paths
  Implement testing framework for pidns
  Add tests for PID namespace translation

 Makefile.am                                   |   4 +
 NEWS                                          |   1 +
 affinity.c                                    |   6 +-
 block.c                                       |   2 +-
 bpf.c                                         |   2 +-
 capability.c                                  |   4 +-
 clone.c                                       |  14 +-
 defs.h                                        |  60 +-
 fcntl.c                                       |  24 +-
 get_robust_list.c                             |   3 +-
 getpid.c                                      |  46 ++
 ioprio.c                                      |  26 +-
 ipc_shmctl.c                                  |   4 +-
 kcmp.c                                        |   5 +-
 largefile_wrappers.h                          |   2 +
 linux/dummy.h                                 |   8 +-
 mmap_cache.c                                  |   2 +-
 msghdr.c                                      |   2 +-
 net.c                                         |   2 +-
 netlink.c                                     |   5 +-
 numa.c                                        |   6 +-
 pathtrace.c                                   |   5 +-
 pidfd_open.c                                  |   2 +-
 pidns.c                                       | 604 ++++++++++++++++++
 print_fields.h                                |  24 +
 printsiginfo.c                                |   2 +-
 process.c                                     |   3 +-
 process_vm.c                                  |   6 +-
 resource.c                                    |  27 +-
 sched.c                                       |  25 +-
 signal.c                                      |  21 +-
 sockaddr.c                                    |   2 +-
 strace.1.in                                   |   4 +
 strace.c                                      |  11 +-
 syscall.c                                     |  15 +
 tests/.gitignore                              |  31 +
 tests/Makefile.am                             |  38 ++
 tests/fcntl--pidns-translation.c              |   2 +
 tests/fcntl-common.c                          |  82 ++-
 tests/fcntl.c                                 |   1 +
 tests/fcntl64--pidns-translation.c            |   2 +
 tests/fcntl64.c                               |   3 +
 tests/fork--pidns-translation.awk             |  15 +
 tests/fork--pidns-translation.c               |  69 ++
 tests/fork--pidns-translation.test            |  16 +
 tests/gen_tests.in                            |  29 +-
 tests/getpgrp--pidns-translation.c            |   2 +
 tests/getpgrp.c                               |   8 +-
 tests/getpid--pidns-translation.c             |   2 +
 tests/getpid.c                                |   8 +-
 tests/getsid--pidns-translation.c             |   2 +
 tests/getsid.c                                |   9 +-
 tests/gettid--pidns-translation.c             |   2 +
 tests/gettid--pidns-translation.test          |  19 +
 tests/gettid.c                                |   8 +-
 tests/init.sh                                 |  31 +
 tests/ioctl_block--pidns-translation.c        |   2 +
 tests/ioctl_block--pidns-translation.test     |  24 +
 tests/ioctl_block.c                           |  24 +-
 tests/ioprio--pidns-translation.c             |   2 +
 tests/ioprio.c                                |  54 +-
 tests/kcmp-y--pidns-translation.c             |   2 +
 tests/kcmp.c                                  |  36 +-
 tests/kill--pidns-translation.c               |   2 +
 tests/kill.c                                  |  12 +-
 tests/migrate_pages--pidns-translation.c      |   2 +
 tests/migrate_pages.c                         |  17 +-
 tests/move_pages--pidns-translation.c         |   2 +
 tests/move_pages.c                            |  51 +-
 tests/net-sockaddr--pidns-translation.c       |   2 +
 tests/net-sockaddr.c                          |  66 +-
 tests/netlink_audit--pidns-translation.c      |   2 +
 tests/netlink_audit--pidns-translation.test   |  13 +
 tests/netlink_audit.c                         |  11 +-
 tests/pidfd_open--pidns-translation.c         |   2 +
 tests/pidfd_open.c                            |  21 +-
 tests/pidfd_send_signal--pidns-translation.c  |   2 +
 tests/pidfd_send_signal.c                     |  13 +-
 tests/pidns.c                                 | 214 +++++++
 tests/pidns.h                                 |  56 ++
 tests/prlimit64--pidns-translation.c          |   2 +
 tests/prlimit64.c                             |  17 +-
 tests/process_vm_readv--pidns-translation.c   |   2 +
 tests/process_vm_readv_writev.c               |  27 +-
 tests/process_vm_writev--pidns-translation.c  |   2 +
 tests/rt_sigqueueinfo--pidns-translation.c    |   2 +
 tests/rt_sigqueueinfo.c                       |  15 +-
 tests/rt_tgsigqueueinfo--pidns-translation.c  |   2 +
 tests/rt_tgsigqueueinfo.c                     |  26 +-
 tests/sched_xetaffinity--pidns-translation.c  |   2 +
 tests/sched_xetaffinity.c                     |  31 +-
 tests/sched_xetattr--pidns-translation.c      |   2 +
 tests/sched_xetattr.c                         |  47 +-
 tests/sched_xetparam--pidns-translation.c     |   2 +
 tests/sched_xetparam.c                        |  20 +-
 tests/sched_xetscheduler--pidns-translation.c |   2 +
 tests/sched_xetscheduler.c                    |  44 +-
 tests/signal_receive--pidns-translation.c     |   2 +
 tests/signal_receive.c                        |  22 +-
 tests/so_peercred--pidns-translation.c        |   2 +
 tests/so_peercred.c                           |  22 +
 tests/xet_robust_list--pidns-translation.c    |   2 +
 tests/xet_robust_list.c                       |  18 +-
 tests/xetpgid--pidns-translation.c            |   2 +
 tests/xetpgid.c                               |  21 +-
 tests/xetpriority--pidns-translation.c        |   2 +
 tests/xetpriority.c                           |  20 +-
 trie.c                                        | 248 +++++++
 trie.h                                        |  89 +++
 util.c                                        |  27 +-
 wait.c                                        |  36 +-
 111 files changed, 2493 insertions(+), 255 deletions(-)
 create mode 100644 getpid.c
 create mode 100644 pidns.c
 create mode 100644 tests/fcntl--pidns-translation.c
 create mode 100644 tests/fcntl64--pidns-translation.c
 create mode 100644 tests/fork--pidns-translation.awk
 create mode 100644 tests/fork--pidns-translation.c
 create mode 100755 tests/fork--pidns-translation.test
 create mode 100644 tests/getpgrp--pidns-translation.c
 create mode 100644 tests/getpid--pidns-translation.c
 create mode 100644 tests/getsid--pidns-translation.c
 create mode 100644 tests/gettid--pidns-translation.c
 create mode 100755 tests/gettid--pidns-translation.test
 create mode 100644 tests/ioctl_block--pidns-translation.c
 create mode 100755 tests/ioctl_block--pidns-translation.test
 create mode 100644 tests/ioprio--pidns-translation.c
 create mode 100644 tests/kcmp-y--pidns-translation.c
 create mode 100644 tests/kill--pidns-translation.c
 create mode 100644 tests/migrate_pages--pidns-translation.c
 create mode 100644 tests/move_pages--pidns-translation.c
 create mode 100644 tests/net-sockaddr--pidns-translation.c
 create mode 100644 tests/netlink_audit--pidns-translation.c
 create mode 100755 tests/netlink_audit--pidns-translation.test
 create mode 100644 tests/pidfd_open--pidns-translation.c
 create mode 100644 tests/pidfd_send_signal--pidns-translation.c
 create mode 100644 tests/pidns.c
 create mode 100644 tests/pidns.h
 create mode 100644 tests/prlimit64--pidns-translation.c
 create mode 100644 tests/process_vm_readv--pidns-translation.c
 create mode 100644 tests/process_vm_writev--pidns-translation.c
 create mode 100644 tests/rt_sigqueueinfo--pidns-translation.c
 create mode 100644 tests/rt_tgsigqueueinfo--pidns-translation.c
 create mode 100644 tests/sched_xetaffinity--pidns-translation.c
 create mode 100644 tests/sched_xetattr--pidns-translation.c
 create mode 100644 tests/sched_xetparam--pidns-translation.c
 create mode 100644 tests/sched_xetscheduler--pidns-translation.c
 create mode 100644 tests/signal_receive--pidns-translation.c
 create mode 100644 tests/so_peercred--pidns-translation.c
 create mode 100644 tests/xet_robust_list--pidns-translation.c
 create mode 100644 tests/xetpgid--pidns-translation.c
 create mode 100644 tests/xetpriority--pidns-translation.c
 create mode 100644 trie.c
 create mode 100644 trie.h

--
2.27.0


From uzonyi.akos at gmail.com  Sat Aug  8 21:14:33 2020
From: uzonyi.akos at gmail.com (=?UTF-8?q?=C3=81kos=20Uzonyi?=)
Date: Sat,  8 Aug 2020 23:14:33 +0200
Subject: [PATCH v7 1/5] PID namespace translation support
In-Reply-To: <20200808211437.469898-1-uzonyi.akos@gmail.com>
References: <20200808211437.469898-1-uzonyi.akos@gmail.com>
Message-ID: <20200808211437.469898-2-uzonyi.akos@gmail.com>

* defs.h (pidns_translation): New variable.
(tcb): Add pid_ns field.
(RVAL_MASK): Change value from 013 to 017.
(RVAL_TID, RVAL_SID, RVAL_TGID, RVAL_PGID): New definitions.
(pid_type): New enum.
(pidns_init, translate_pid, get_proc_pid, printpid, printpid_tgid_pgid):
New function declarations.
* largefile_wrappers.h (fstat_fd): New macro.
* pidns.c: New file.
* trie.c: New file.
* trie.h: New file.
* Makefile.am (libstrace_a_SOURCES): Add trie.c, trie.h, pidns.c.
* strace.c (pidns_translation): New variable.
(init): Add --pidns-translation option.
* syscall.c (syscall_exiting_trace): Handle RVAL_* return values.
* NEWS: Mention this.
* strace.1.in: Add description for new option.

Co-Authored-by: Eugene Syromyatnikov <evgsyr at gmail.com>
---
 Makefile.am          |   3 +
 NEWS                 |   1 +
 defs.h               |  55 +++-
 largefile_wrappers.h |   2 +
 pidns.c              | 604 +++++++++++++++++++++++++++++++++++++++++++
 strace.1.in          |   4 +
 strace.c             |   9 +
 syscall.c            |  15 ++
 trie.c               | 248 ++++++++++++++++++
 trie.h               |  89 +++++++
 10 files changed, 1029 insertions(+), 1 deletion(-)
 create mode 100644 pidns.c
 create mode 100644 trie.c
 create mode 100644 trie.h

diff --git a/Makefile.am b/Makefile.am
index f5447811..73c22035 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -233,6 +233,7 @@ libstrace_a_SOURCES =	\
 	personality.c	\
 	pidfd_getfd.c	\
 	pidfd_open.c	\
+	pidns.c		\
 	pkeys.c		\
 	poll.c		\
 	prctl.c		\
@@ -344,6 +345,8 @@ libstrace_a_SOURCES =	\
 	time.c		\
 	times.c		\
 	trace_event.h	\
+	trie.c 		\
+	trie.h 		\
 	truncate.c	\
 	ubi.c		\
 	ucopy.c		\
diff --git a/NEWS b/NEWS
index 10039ceb..2ebe45c1 100644
--- a/NEWS
+++ b/NEWS
@@ -22,6 +22,7 @@ Noteworthy changes in release 5.8 (2020-08-06)
     KEYCTL_*, KVM_*, LOOP_*, NDA_*, RTC_*, TCA_*, STATX_*, and *_MAGIC
     constants.
   * Updated lists of ioctl commands from Linux 5.8.
+  * Added --pidns-translation option for PID namespace translation.
 
 * Bug fixes
   * Added statx syscall to %fstat trace class.
diff --git a/defs.h b/defs.h
index f7ac54f3..ea77f1ff 100644
--- a/defs.h
+++ b/defs.h
@@ -280,6 +280,13 @@ struct tcb {
 	struct timespec etime;	/* Syscall entry time (CLOCK_MONOTONIC) */
 	struct timespec delay_expiration_time; /* When does the delay end */
 
+	/*
+	 * The ID of the PID namespace of this process
+	 * (inode number of /proc/<pid>/ns/pid)
+	 * (0: not initialized)
+	 */
+	unsigned int pid_ns;
+
 	struct mmap_cache_t *mmap_cache;
 
 	/*
@@ -413,7 +420,11 @@ extern const struct xlat whence_codes[];
 # define RVAL_HEX	001	/* hex format */
 # define RVAL_OCTAL	002	/* octal format */
 # define RVAL_FD		010	/* file descriptor */
-# define RVAL_MASK	013	/* mask for these values */
+# define RVAL_TID	011	/* task ID */
+# define RVAL_SID	012	/* session ID */
+# define RVAL_TGID	013	/* thread group ID */
+# define RVAL_PGID	014	/* process group ID */
+# define RVAL_MASK	017	/* mask for these values */
 
 # define RVAL_STR	020	/* Print `auxstr' field after return val */
 # define RVAL_NONE	040	/* Print nothing */
@@ -428,6 +439,16 @@ extern const struct xlat whence_codes[];
 
 # define indirect_ipccall(tcp) (tcp_sysent(tcp)->sys_flags & TRACE_INDIRECT_SUBCALL)
 
+enum pid_type {
+	PT_TID,
+	PT_TGID,
+	PT_PGID,
+	PT_SID,
+
+	PT_COUNT,
+	PT_NONE = -1
+};
+
 enum sock_proto {
 	SOCK_PROTO_UNKNOWN,
 	SOCK_PROTO_UNIX,
@@ -469,6 +490,7 @@ extern int Tflag_scale;
 extern int Tflag_width;
 extern bool iflag;
 extern bool count_wallclock;
+extern unsigned int pidns_translation;
 /* are we filtering traces based on paths? */
 extern struct path_set {
 	const char **paths_selected;
@@ -983,6 +1005,28 @@ print_local_array_ex(struct tcb *tcp,
 extern kernel_ulong_t *
 fetch_indirect_syscall_args(struct tcb *, kernel_ulong_t addr, unsigned int n_args);
 
+extern void pidns_init(void);
+
+/**
+ * Returns the pid of the tracee as present in /proc of the tracer (can be
+ * different from tcp->pid if /proc and the tracee process are in different PID
+ * namespaces).
+ */
+extern int get_proc_pid(struct tcb *);
+
+/**
+ * Translates a pid from tracee's namespace to our namepace.
+ *
+ * @param tcp             The tcb of the tracee
+ *                        (NULL: from_id is in strace's namespace. Useful for
+ *                         getting the proc PID of from_id)
+ * @param from_id         The id to be translated
+ * @param type            The PID type of from_id
+ * @param proc_pid_ptr    If not NULL, writes the proc PID to this location
+ */
+extern int translate_pid(struct tcb *, int dest_id, enum pid_type type,
+		    int *proc_pid_ptr);
+
 extern void
 dumpiov_in_msghdr(struct tcb *, kernel_ulong_t addr, kernel_ulong_t data_size);
 
@@ -1058,6 +1102,15 @@ printfd(struct tcb *tcp, int fd)
  * of the tracee the descriptor tcp).  This is a stub.
  */
 extern void printfd_pid_tracee_ns(struct tcb *tcp, pid_t pid, int fd);
+
+/** Prints a PID in the tracee's PID namespace */
+extern void printpid(struct tcb *, int pid, enum pid_type type);
+
+/**
+ * Prints pid as a TGID if positive, and PGID if negative
+ * (like the first argument of kill).
+ */
+extern void printpid_tgid_pgid(struct tcb *, int pid);
 extern void print_sockaddr(struct tcb *, const void *sa, int len);
 extern bool
 print_inet_addr(int af, const void *addr, unsigned int len, const char *var_name);
diff --git a/largefile_wrappers.h b/largefile_wrappers.h
index 116e7048..9d8f5c92 100644
--- a/largefile_wrappers.h
+++ b/largefile_wrappers.h
@@ -29,6 +29,7 @@
 #  else
 #   define fcntl_fd fcntl
 #  endif
+#  define fstat_fd fstat64
 #  define strace_stat_t struct stat64
 #  define stat_file stat64
 #  define struct_dirent struct dirent64
@@ -39,6 +40,7 @@
 #  define open_file open
 #  define fopen_stream fopen
 #  define fcntl_fd fcntl
+#  define fstat_fd fstat
 #  define strace_stat_t struct stat
 #  define stat_file stat
 #  define struct_dirent struct dirent
diff --git a/pidns.c b/pidns.c
new file mode 100644
index 00000000..2f43838d
--- /dev/null
+++ b/pidns.c
@@ -0,0 +1,604 @@
+/*
+ * Copyright (c) 2020 ?kos Uzonyi <uzonyi.akos at gmail.com>
+ * All rights reserved.
+ *
+ * SPDX-License-Identifier: LGPL-2.1-or-later
+ */
+
+#include "defs.h"
+
+
+#include <dirent.h>
+#include <fcntl.h>
+#include <stdint.h>
+#include <string.h>
+#include <unistd.h>
+
+#include <asm/unistd.h>
+
+#include <sys/ioctl.h>
+#include <sys/param.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+
+#include "largefile_wrappers.h"
+#include "trie.h"
+#include "nsfs.h"
+#include "xmalloc.h"
+#include "xstring.h"
+
+/**
+ * Key:   PID NS ID
+ * Value: a btree:
+ *           Key:   a process PID in NS
+ *           Value: the process's PID as present in /proc
+ */
+static struct trie *ns_pid_to_proc_pid[PT_COUNT];
+
+/**
+ * Key:   Proc PID
+ * Value: struct proc_data
+ */
+static struct trie *proc_data_cache;
+
+static bool ns_get_parent_enotty = false;
+
+static const char tid_str[]  = "NSpid:\t";
+static const char tgid_str[] = "NStgid:\t";
+static const char pgid_str[] = "NSpgid:\t";
+static const char sid_str[]  = "NSsid:\t";
+
+static const struct {
+	const char *str;
+	size_t size;
+} id_strs[PT_COUNT] = {
+	[PT_TID] =  { tid_str,  sizeof(tid_str)  - 1 },
+	[PT_TGID] = { tgid_str, sizeof(tgid_str) - 1 },
+	[PT_PGID] = { pgid_str, sizeof(pgid_str) - 1 },
+	[PT_SID] =  { sid_str,  sizeof(sid_str)  - 1 },
+};
+
+
+/**
+ * Limit on PID NS hierarchy depth, imposed since Linux 3.7. NS traversal
+ * is not possible before Linux 4.9, so we consider this limit pretty universal.
+ */
+#define MAX_NS_DEPTH 32
+
+static const size_t ns_id_size = sizeof(unsigned int);
+static const uint8_t ptr_sz_lg = (sizeof(void *) == 8 ? 6 : 5);
+
+static int pid_max;
+static uint8_t pid_max_size, pid_max_size_lg;
+
+struct proc_data {
+	int proc_pid;
+	int ns_count;
+	unsigned int ns_hierarchy[MAX_NS_DEPTH];
+	int id_count[PT_COUNT];
+	int id_hierarchy[PT_COUNT][MAX_NS_DEPTH];
+};
+
+/**
+ * Helper function for creating a trie.
+ *
+ * For node_key_bits and data_block_key_bits 4 is used (so trie height is 32 / 4
+ * = 8, and node sizes are 8 byte * 2^4 = 128 bytes), which seems to be a good
+ * tradeoff between memory usage and lookup time. It should not be too large,
+ * since there can be large holes between PIDs, and it would be just a waste of
+ * memory having large nodes with lot of NULL pointers in them.
+ */
+static struct trie *
+create_trie_4(uint8_t key_size, uint8_t item_size_lg, uint64_t empty_value)
+{
+	struct trie *t = trie_create(key_size, item_size_lg, 4, 4, empty_value);
+	if (!t)
+		error_msg_and_die("creating trie failed");
+
+	return t;
+}
+
+void
+pidns_init(void)
+{
+	if (proc_data_cache)
+		return;
+
+	pid_max = INT_MAX;
+	if (read_int_from_file("/proc/sys/kernel/pid_max", &pid_max) < 0)
+		debug_func_perror_msg("reading /proc/sys/kernel/pid_max");
+	pid_max_size = ilog2_32(pid_max - 1) + 1;
+	pid_max_size_lg = ilog2_32(pid_max_size - 1) + 1;
+
+	for (int i = 0; i < PT_COUNT; i++)
+		ns_pid_to_proc_pid[i] = create_trie_4(ns_id_size, ptr_sz_lg, 0);
+
+	proc_data_cache = create_trie_4(pid_max_size, ptr_sz_lg, 0);
+}
+
+static void
+put_proc_pid(unsigned int ns, int ns_pid, enum pid_type type, int proc_pid)
+{
+	struct trie *b = (struct trie *) (uintptr_t) trie_get(ns_pid_to_proc_pid[type], ns);
+	if (!b) {
+		b = create_trie_4(pid_max_size, pid_max_size_lg, 0);
+		trie_set(ns_pid_to_proc_pid[type], ns, (uint64_t) (uintptr_t) b);
+	}
+	trie_set(b, ns_pid, proc_pid);
+}
+
+static int
+get_cached_proc_pid(unsigned int ns, int ns_pid, enum pid_type type)
+{
+	struct trie *b = (struct trie *) (uintptr_t)
+		trie_get(ns_pid_to_proc_pid[type], ns);
+	if (!b)
+		return 0;
+
+	return trie_get(b, ns_pid);
+}
+
+/**
+ * Helper function, converts pid to string, or to "self" for pid == 0.
+ * Uses static buffer for operation.
+ */
+static const char *
+pid_to_str(pid_t pid)
+{
+	if (!pid)
+		return "self";
+
+	static char buf[sizeof("-2147483648")];
+	xsprintf(buf, "%d", pid);
+	return buf;
+}
+
+/**
+ * Returns a list of PID NS IDs for the specified PID.
+ *
+ * @param proc_pid PID (as present in /proc) to get information for.
+ * @param ns_buf   Pointer to buffer that is able to contain at least
+ *                 ns_buf_size items.
+ * @return         Amount of NS in list. 0 indicates error.
+ */
+static size_t
+get_ns_hierarchy(int proc_pid, unsigned int *ns_buf, size_t ns_buf_size)
+{
+	char path[PATH_MAX + 1];
+	xsprintf(path, "/proc/%s/ns/pid", pid_to_str(proc_pid));
+
+	int fd = open_file(path, O_RDONLY);
+	if (fd < 0)
+		return 0;
+
+	size_t n = 0;
+	while (n < ns_buf_size) {
+		strace_stat_t st;
+		if (fstat_fd(fd, &st))
+			break;
+
+		ns_buf[n++] = st.st_ino;
+		if (n >= ns_buf_size)
+			break;
+
+		if (ns_get_parent_enotty)
+			break;
+
+		int parent_fd = ioctl(fd, NS_GET_PARENT);
+		if (parent_fd < 0) {
+			switch (errno) {
+			case EPERM:
+				break;
+
+			case ENOTTY:
+				ns_get_parent_enotty = true;
+				error_msg("NS_* ioctl commands are not "
+					  "supported by the kernel");
+				break;
+
+			default:
+				perror_func_msg("ioctl(NS_GET_PARENT)");
+				break;
+			}
+
+			break;
+		}
+
+		close(fd);
+		fd = parent_fd;
+	}
+
+	close(fd);
+
+	return n;
+}
+
+/**
+ * Get list of IDs present in NS* proc status record. IDs are placed as they are
+ * stored in /proc (from top to bottom of NS hierarchy).
+ *
+ * @param proc_pid    PID (as present in /proc) to get information for.
+ * @param id_buf      Pointer to buffer that is able to contain at least
+ *                    MAX_NS_DEPTH items. Can be NULL.
+ * @param type        Type of ID requested.
+ * @return            Number of items stored in id_list. 0 indicates error.
+ */
+static size_t
+get_id_list(int proc_pid, int *id_buf, enum pid_type type)
+{
+	const char *ns_str = id_strs[type].str;
+	size_t ns_str_size = id_strs[type].size;
+
+	size_t n = 0;
+
+	char status_path[PATH_MAX + 1];
+	xsprintf(status_path, "/proc/%s/status", pid_to_str(proc_pid));
+	FILE *f = fopen_stream(status_path, "r");
+	if (!f)
+		return 0;
+
+	char *line = NULL;
+	size_t linesize = 0;
+	char *p = NULL;
+
+	while (getline(&line, &linesize, f) > 0) {
+		if (strncmp(line, ns_str, ns_str_size) == 0) {
+			p = line + ns_str_size;
+			break;
+		}
+	}
+
+	while (p) {
+		errno = 0;
+		long id = strtol(p, NULL, 10);
+
+		if (errno || id < 1 || id > INT_MAX) {
+			perror_func_msg("converting pid (%ld) to int", id);
+			break;
+		}
+
+		if (id_buf)
+			id_buf[n] = (int) id;
+
+		n++;
+		strsep(&p, "\t");
+	}
+
+	free(line);
+	fclose(f);
+
+	return n;
+}
+
+/**
+ * Returns whether the /proc filesystem's PID namespace is the same as strace's.
+ */
+static bool
+is_proc_ours(void)
+{
+	static int cached_val = -1;
+
+	if (cached_val < 0)
+		cached_val = get_id_list(0, NULL, PT_TID) == 1;
+
+	return cached_val;
+}
+
+/**
+ * Returns the PID namespace of the tracee
+ */
+static unsigned int
+get_ns(struct tcb *tcp)
+{
+	if (!tcp->pid_ns) {
+		int proc_pid = 0;
+		translate_pid(NULL, tcp->pid, PT_TID, &proc_pid);
+
+		if (proc_pid)
+			get_ns_hierarchy(proc_pid, &tcp->pid_ns, 1);
+	}
+
+	return tcp->pid_ns;
+}
+
+/**
+ * Returns the PID namespace of strace
+ */
+static unsigned int
+get_our_ns(void)
+{
+	static unsigned int our_ns = 0;
+	static bool our_ns_initialised = false;
+
+	if (!our_ns_initialised) {
+		get_ns_hierarchy(0, &our_ns, 1);
+		our_ns_initialised = true;
+	}
+
+	return our_ns;
+}
+
+/**
+ * Returns the cached proc_data struct associated with proc_pid.
+ * If none found, allocates a new proc_data.
+ */
+static struct proc_data *
+get_or_create_proc_data(int proc_pid)
+{
+	struct proc_data *pd = (struct proc_data *) (uintptr_t)
+		trie_get(proc_data_cache, proc_pid);
+
+	if (!pd) {
+		pd = calloc(1, sizeof(*pd));
+		if (!pd)
+			return NULL;
+
+		pd->proc_pid = proc_pid;
+		trie_set(proc_data_cache, proc_pid, (uint64_t) (uintptr_t) pd);
+	}
+
+	return pd;
+}
+
+/**
+ * Updates the proc_data from /proc
+ * If the process does not exists, returns false, and frees the proc_data
+ */
+static bool
+update_proc_data(struct proc_data *pd, enum pid_type type)
+{
+	pd->ns_count = get_ns_hierarchy(pd->proc_pid,
+		pd->ns_hierarchy, MAX_NS_DEPTH);
+	if (!pd->ns_count)
+		goto fail;
+
+	pd->id_count[type] = get_id_list(pd->proc_pid,
+		pd->id_hierarchy[type], type);
+	if (!pd->id_count[type])
+		goto fail;
+
+	return true;
+
+fail:
+	trie_set(proc_data_cache, pd->proc_pid, (uint64_t) (uintptr_t) NULL);
+	free(pd);
+	return false;
+}
+
+/**
+ * Paramters for id translation
+ */
+struct translate_id_params {
+	/* The result (output) */
+	int result_id;
+	/* The proc data of the process (output) */
+	struct proc_data *pd;
+
+	/* The namespace to be translated from */
+	unsigned int from_ns;
+	/* The id to be translated */
+	int from_id;
+	/* The type of the id */
+	enum pid_type type;
+};
+
+/**
+ * Translates an id to our namespace, given the proc_pid of the process,
+ * by reading files in /proc.
+ *
+ * @param tip      The parameters
+ * @param proc_pid The proc pid of the process.
+ *                 If 0, use the cached values in tip->pd.
+ */
+static void
+translate_id_proc_pid(struct translate_id_params *tip, int proc_pid)
+{
+	struct proc_data *pd = proc_pid ?
+		get_or_create_proc_data(proc_pid) :
+		tip->pd;
+
+	tip->result_id = 0;
+	tip->pd = NULL;
+
+	if (!pd)
+		return;
+
+	if (proc_pid && !update_proc_data(pd, tip->type))
+		return;
+
+	if (!pd->ns_count || pd->id_count[tip->type] < pd->ns_count)
+		return;
+
+	int our_ns_id_idx = pd->id_count[tip->type] - pd->ns_count;
+
+	for (int i = 0; i < pd->ns_count; i++) {
+		if (pd->ns_hierarchy[i] != tip->from_ns)
+			continue;
+
+		int id_idx = pd->id_count[tip->type] - i - 1;
+		if (pd->id_hierarchy[tip->type][id_idx] != tip->from_id)
+			return;
+
+		tip->result_id = pd->id_hierarchy[tip->type][our_ns_id_idx];
+		tip->pd = pd;
+		return;
+	}
+}
+
+/**
+ * Translates an id to our namespace, by reading all proc entries in dir.
+ *
+ * @param tip            The parameters
+ * @param path           The path of the dir to be read.
+ * @param read_task_dir  Whether recurse to "task" subdirectory.
+ */
+static void
+translate_id_dir(struct translate_id_params *tip, const char *path,
+                 bool read_task_dir)
+{
+	DIR *dir = opendir(path);
+	if (!dir) {
+		debug_func_perror_msg("opening dir: %s", path);
+		return;
+	}
+
+	while (!tip->result_id) {
+		errno = 0;
+		struct_dirent *entry = read_dir(dir);
+		if (!entry) {
+			if (errno)
+				perror_func_msg("readdir");
+
+			break;
+		}
+
+		if (entry->d_type != DT_DIR)
+			continue;
+
+		errno = 0;
+		long proc_pid = strtol(entry->d_name, NULL, 10);
+		if (errno)
+			continue;
+		if (proc_pid < 1 || proc_pid > INT_MAX)
+			continue;
+
+		if (read_task_dir) {
+			char task_dir_path[PATH_MAX + 1];
+			xsprintf(task_dir_path, "/proc/%ld/task", proc_pid);
+			translate_id_dir(tip, task_dir_path, false);
+		}
+
+		if (tip->result_id)
+			break;
+
+		translate_id_proc_pid(tip, proc_pid);
+	}
+
+	closedir(dir);
+}
+
+/**
+ * Iterator function of the proc_data_cache for id translation.
+ * If the cache contains the id we are looking for, reads the corresponding
+ * directory in /proc, and if cache is valid, saves the result.
+ */
+static void
+proc_data_cache_iterator_fn(void* fn_data, uint64_t key, uint64_t val)
+{
+	struct translate_id_params *tip = (struct translate_id_params *)fn_data;
+	struct proc_data *pd = (struct proc_data *) (uintptr_t) val;
+
+	if (!pd)
+		return;
+
+	/* Result already found in an earlier iteration */
+	if (tip->result_id)
+		return;
+
+	/* Translate from cache */
+	tip->pd = pd;
+	translate_id_proc_pid(tip, 0);
+	if (!tip->result_id)
+		return;
+
+	/* Now translate from actual data in /proc, to check cache validity */
+	translate_id_proc_pid(tip, pd->proc_pid);
+}
+
+int
+translate_pid(struct tcb *tcp, int from_id, enum pid_type type,
+              int *proc_pid_ptr)
+{
+	if (from_id <= 0 || type < 0 || type >= PT_COUNT)
+		return 0;
+
+	/* If translation is trivial */
+	if ((!tcp || get_ns(tcp) == get_our_ns()) &&
+	    (is_proc_ours() || !proc_pid_ptr)) {
+		if (proc_pid_ptr)
+			*proc_pid_ptr = from_id;
+
+		return from_id;
+	}
+
+	struct translate_id_params tip = {
+		.result_id = 0,
+		.pd = NULL,
+		.from_ns = tcp ? get_ns(tcp) : get_our_ns(),
+		.from_id = from_id,
+		.type = type,
+	};
+
+	if (!tip.from_ns)
+		return 0;
+
+	if (ns_get_parent_enotty)
+		return 0;
+
+	/* Look for a cached proc_pid for this (from_ns, from_id) pair */
+	int cached_proc_pid = get_cached_proc_pid(tip.from_ns, tip.from_id,
+		tip.type);
+	if (cached_proc_pid) {
+		translate_id_proc_pid(&tip, cached_proc_pid);
+		if (tip.result_id)
+			goto exit;
+	}
+
+	/* Iterate through the cache, find potential proc_data */
+	trie_iterate_keys(proc_data_cache, 0, pid_max,
+		proc_data_cache_iterator_fn, &tip);
+	/* (proc_data_cache_iterator_fn takes care about updating proc_data) */
+	if (tip.result_id)
+		goto exit;
+
+	/* No cache helped, read all entries in /proc */
+	translate_id_dir(&tip, "/proc", true);
+
+exit:
+	if (tip.pd) {
+		if (tip.pd->proc_pid)
+			put_proc_pid(tip.from_ns, tip.from_id, tip.type,
+				tip.pd->proc_pid);
+
+		if (proc_pid_ptr)
+			*proc_pid_ptr = tip.pd->proc_pid;
+	}
+
+	return tip.result_id;
+}
+
+int
+get_proc_pid(struct tcb *tcp)
+{
+	int proc_pid = 0;
+	translate_pid(NULL, tcp->pid, PT_TID, &proc_pid);
+	return proc_pid;
+}
+
+static void
+printpid_translation(struct tcb *tcp, int pid, enum pid_type type)
+{
+	if (!pidns_translation)
+		return;
+
+	int strace_pid = translate_pid(tcp, pid, type, NULL);
+	if (strace_pid && strace_pid != pid)
+		tprintf_comment("%d in strace's PID NS", strace_pid);
+}
+
+void
+printpid(struct tcb *tcp, int pid, enum pid_type type)
+{
+	tprintf("%d", pid);
+	printpid_translation(tcp, pid, type);
+}
+
+void
+printpid_tgid_pgid(struct tcb *tcp, int pid)
+{
+	tprintf("%d", pid);
+	if (pid > 0)
+		printpid_translation(tcp,  pid, PT_TGID);
+	else if (pid < -1)
+		printpid_translation(tcp, -pid, PT_PGID);
+}
diff --git a/strace.1.in b/strace.1.in
index 3b21caec..83776e88 100644
--- a/strace.1.in
+++ b/strace.1.in
@@ -1075,6 +1075,10 @@ Print all available information associated with file descritors:
 protocol-specific information associated with socket file descriptors,
 block/character device number associated with device file descriptors,
 and PIDs asociated with pidfd file descriptors.
+.TP
+.B \-\-pidns\-translation
+If strace and tracee are in different PID namespaces, print PIDs in
+strace's namespace, too.
 .SS Statistics
 .TP 12
 .B \-c
diff --git a/strace.c b/strace.c
index 4c96a98b..249533ea 100644
--- a/strace.c
+++ b/strace.c
@@ -133,6 +133,8 @@ static unsigned int daemonized_tracer;
 static int post_attach_sigstop = TCB_IGNORE_ONE_SIGSTOP;
 #define use_seize (post_attach_sigstop == 0)
 
+unsigned int pidns_translation;
+
 static bool detach_on_execve;
 
 static int exit_code;
@@ -1998,6 +2000,8 @@ init(int argc, char *argv[])
 
 	os_release = get_os_release();
 
+	pidns_init();
+
 	shared_log = stderr;
 	set_sortby(DEFAULT_SORTBY);
 	set_personality(DEFAULT_PERSONALITY);
@@ -2022,6 +2026,7 @@ init(int argc, char *argv[])
 		GETOPT_FOLLOWFORKS,
 		GETOPT_OUTPUT_SEPARATELY,
 		GETOPT_TS,
+		GETOPT_PIDNS_TRANSLATION,
 
 		GETOPT_QUAL_TRACE,
 		GETOPT_QUAL_ABBREV,
@@ -2072,6 +2077,7 @@ init(int argc, char *argv[])
 		{ "summary-wall-clock", no_argument,	   0, 'w' },
 		{ "strings-in-hex",	optional_argument, 0, GETOPT_HEX_STR },
 		{ "const-print-style",	required_argument, 0, 'X' },
+		{ "pidns-translation",	no_argument      , 0, GETOPT_PIDNS_TRANSLATION },
 		{ "successful-only",	no_argument,	   0, 'z' },
 		{ "failed-only",	no_argument,	   0, 'Z' },
 		{ "failing-only",	no_argument,	   0, 'Z' },
@@ -2285,6 +2291,9 @@ init(int argc, char *argv[])
 		case 'y':
 			yflag_short++;
 			break;
+		case GETOPT_PIDNS_TRANSLATION:
+			pidns_translation++;
+			break;
 		case 'z':
 			clear_number_set_array(status_set, 1);
 			add_number_to_set(STATUS_SUCCESSFUL, status_set);
diff --git a/syscall.c b/syscall.c
index bcc87025..0f4bab6d 100644
--- a/syscall.c
+++ b/syscall.c
@@ -937,6 +937,21 @@ syscall_exiting_trace(struct tcb *tcp, struct timespec *ts, int res)
 					tprintf("= %" PRI_kld, tcp->u_rval);
 				}
 				break;
+			case RVAL_TID:
+			case RVAL_SID:
+			case RVAL_TGID:
+			case RVAL_PGID: {
+				#define _(_t) [RVAL_##_t - RVAL_TID] = PT_##_t
+				static const enum pid_type types[] = {
+					_(TID), _(SID), _(TGID), _(PGID),
+				};
+				#undef _
+
+				tprints("= ");
+				printpid(tcp, tcp->u_rval,
+					 types[(sys_res & RVAL_MASK) - RVAL_TID]);
+				break;
+			}
 			default:
 				error_msg("invalid rval format");
 				break;
diff --git a/trie.c b/trie.c
new file mode 100644
index 00000000..b7d56ed5
--- /dev/null
+++ b/trie.c
@@ -0,0 +1,248 @@
+/*
+ * Simple trie implementation for key-value mapping storage
+ *
+ * Copyright (c) 2020 ?kos Uzonyi <uzonyi.akos at gmail.com>
+ * All rights reserved.
+ *
+ * SPDX-License-Identifier: LGPL-2.1-or-later
+ */
+
+#include "defs.h"
+
+#include <stdbool.h>
+#include <stdint.h>
+#include <stdlib.h>
+
+#include "trie.h"
+
+static const uint8_t ptr_sz_lg = (sizeof(void *) == 8 ? 6 : 5);
+
+/**
+ * Returns lg2 of node size in bits for the specific level of the trie.
+ */
+static uint8_t
+trie_get_node_size(struct trie *t, uint8_t depth)
+{
+	/* Last level contains data and we allow it having a different size */
+	if (depth == t->max_depth)
+		return t->data_block_key_bits + t->item_size_lg;
+	/* Last level of the tree can be smaller */
+	if (depth == t->max_depth - 1)
+		return (t->key_size - t->data_block_key_bits - 1) %
+		t->node_key_bits + 1 + ptr_sz_lg;
+
+	return t->node_key_bits + ptr_sz_lg;
+}
+
+/**
+ * Provides starting offset of bits in key corresponding to the node index
+ * at the specific level.
+ */
+static uint8_t
+trie_get_node_bit_offs(struct trie *t, uint8_t depth)
+{
+	uint8_t offs;
+
+	if (depth == t->max_depth)
+		return 0;
+
+	offs = t->data_block_key_bits;
+
+	if (depth == t->max_depth - 1)
+		return offs;
+
+	/* data_block_size + remainder */
+	offs += trie_get_node_size(t, t->max_depth - 1) - ptr_sz_lg;
+	offs += (t->max_depth - depth - 2) * t->node_key_bits;
+
+	return offs;
+}
+
+struct trie *
+trie_create(uint8_t key_size, uint8_t item_size_lg, uint8_t node_key_bits,
+            uint8_t data_block_key_bits, uint64_t empty_value)
+{
+	if (item_size_lg > 6)
+		return NULL;
+	if (key_size > 64)
+		return NULL;
+	if (node_key_bits < 1)
+		return NULL;
+	if (data_block_key_bits < 1 || data_block_key_bits > key_size)
+		return NULL;
+
+	struct trie *t = malloc(sizeof(*t));
+	if (!t)
+		return NULL;
+
+	t->empty_value = empty_value;
+	t->data = NULL;
+	t->item_size_lg = item_size_lg;
+	t->node_key_bits = node_key_bits;
+	t->data_block_key_bits = data_block_key_bits;
+	t->key_size = key_size;
+	t->max_depth = (key_size - data_block_key_bits + node_key_bits - 1)
+		/ t->node_key_bits;
+
+	return t;
+}
+
+static uint64_t *
+trie_get_node(struct trie *t, uint64_t key, bool auto_create)
+{
+	void **cur_node = &(t->data);
+
+	if (t->key_size < 64 && key > (uint64_t) 1 << t->key_size)
+		return NULL;
+
+	for (uint8_t cur_depth = 0; cur_depth <= t->max_depth; cur_depth++) {
+		uint8_t offs = trie_get_node_bit_offs(t, cur_depth);
+		uint8_t sz = trie_get_node_size(t, cur_depth);
+
+		if (!*cur_node) {
+			if (!auto_create)
+				return NULL;
+
+			*cur_node = xcalloc(1 << sz, 1);
+		}
+
+		if (cur_depth >= t->max_depth)
+			break;
+
+		size_t pos = (key >> offs) & ((1 << (sz - ptr_sz_lg)) - 1);
+		cur_node = (((void **) (*cur_node)) + pos);
+	}
+
+	return (uint64_t *) (*cur_node);
+}
+
+static void
+trie_data_block_calc_pos(struct trie *t, uint64_t key,
+                         uint64_t *pos, uint64_t *mask, uint64_t *offs)
+{
+	uint64_t key_mask;
+
+	key_mask = (1 << t->data_block_key_bits) - 1;
+	*pos = (key & key_mask) >> (6 - t->item_size_lg);
+
+	key_mask = (1 << (6 - t->item_size_lg)) - 1;
+	*offs = (key & key_mask) * (1 << t->item_size_lg);
+
+	*mask = (((uint64_t) 1 << (1 << t->item_size_lg)) - 1) << *offs;
+}
+
+bool
+trie_set(struct trie *t, uint64_t key, uint64_t val)
+{
+	uint64_t *data = trie_get_node(t, key, true);
+	if (!data)
+		return false;
+
+	uint64_t pos, mask, offs;
+	trie_data_block_calc_pos(t, key, &pos, &mask, &offs);
+
+	data[pos] &= ~mask;
+	data[pos] |= (val << offs) & mask;
+
+	return true;
+}
+
+static uint64_t
+trie_data_block_get(struct trie *t, uint64_t *data, uint64_t key)
+{
+	if (!data)
+		return t->empty_value;
+
+	uint64_t pos, mask, offs;
+	trie_data_block_calc_pos(t, key, &pos, &mask, &offs);
+
+	return (data[pos] & mask) >> offs;
+}
+
+uint64_t
+trie_get(struct trie *b, uint64_t key)
+{
+	return trie_data_block_get(b, trie_get_node(b, key, false), key);
+}
+
+static uint64_t
+trie_iterate_keys_node(struct trie *t,
+                       trie_iterate_fn fn, void *fn_data,
+                       void *node, uint64_t start, uint64_t end,
+                       uint8_t depth)
+{
+	if (start > end || !node)
+		return 0;
+
+	if (depth == t->max_depth) {
+		for (uint64_t i = start; i <= end; i++)
+			fn(fn_data, i, trie_data_block_get(t,
+				(uint64_t *) node, i));
+
+		return end - start + 1;
+	}
+
+	uint8_t parent_node_bit_off = depth == 0 ?
+		t->key_size :
+		trie_get_node_bit_offs(t, depth - 1);
+
+	uint64_t first_key_in_node = start &
+		(uint64_t) -1 << parent_node_bit_off;
+
+	uint8_t node_bit_off = trie_get_node_bit_offs(t, depth);
+	uint8_t node_key_bits = parent_node_bit_off - node_bit_off;
+	uint64_t mask = ((uint64_t) 1 << (node_key_bits)) - 1;
+	uint64_t start_index = (start >> node_bit_off) & mask;
+	uint64_t end_index = (end >> node_bit_off) & mask;
+	uint64_t child_key_count = (uint64_t) 1 << node_bit_off;
+
+	uint64_t count = 0;
+
+	for (uint64_t i = start_index; i <= end_index; i++) {
+		uint64_t child_start = first_key_in_node + i * child_key_count;
+		uint64_t child_end = first_key_in_node +
+			(i + 1) * child_key_count - 1;
+
+		if (child_start < start)
+			child_start = start;
+		if (child_end > end)
+			child_end = end;
+
+		count += trie_iterate_keys_node(t, fn, fn_data,
+			((void **) node)[i], child_start, child_end,
+			depth + 1);
+	}
+
+	return count;
+}
+
+uint64_t trie_iterate_keys(struct trie *t, uint64_t start, uint64_t end,
+                           trie_iterate_fn fn, void *fn_data)
+{
+	return trie_iterate_keys_node(t, fn, fn_data, t->data,
+		start, end, 0);
+}
+
+static void
+trie_free_node(struct trie *t, void *node, uint8_t depth)
+{
+	if (!node)
+		return;
+
+	if (depth >= t->max_depth)
+		goto free_node;
+
+	size_t sz = 1 << (trie_get_node_size(t, depth) - ptr_sz_lg);
+	for (size_t i = 0; i < sz; i++)
+		trie_free_node(t, ((void **) node)[i], depth + 1);
+
+free_node:
+	free(node);
+}
+
+void
+trie_free(struct trie *t)
+{
+	trie_free_node(t, t->data, 0);
+	free(t);
+}
diff --git a/trie.h b/trie.h
new file mode 100644
index 00000000..1ff31397
--- /dev/null
+++ b/trie.h
@@ -0,0 +1,89 @@
+/*
+ * Simple trie interface
+ *
+ * Copyright (c) 2020 ?kos Uzonyi <uzonyi.akos at gmail.com>
+ * All rights reserved.
+ *
+ * SPDX-License-Identifier: LGPL-2.1-or-later
+ */
+
+#ifndef STRACE_TRIE_H
+#define STRACE_TRIE_H
+
+/**
+ * Trie control structure.
+ * Trie implemented here has the following properties:
+ *  * It allows storing values of the same size, the size can vary from 1 bit to
+ *    64 bit values (only power of 2 sizes are allowed).
+ *  * The key can be up to 64 bits in size.
+ *  * It has separate configuration for node size and data block size.
+ *
+ * How bits of key are used for different node levels:
+ *
+ *   highest bits                                                  lowest bits
+ *  | node_key_bits | node_key_bits | ... | <remainder> | data_block_key_bits |
+ *  \_________________________________________________________________________/
+ *                                 key_size
+ *
+ * So, the remainder is used on the lowest non-data node level.
+ *
+ * As of now, it doesn't implement any mechanisms for resizing/changing key
+ * size.  De-fragmentation is also unsupported currently.
+ */
+struct trie {
+	/** Return value of trie_get if key is not found */
+	uint64_t empty_value;
+
+	/** Pointer to root node */
+	void *data;
+
+	/** Key size in bits (0..64). */
+	uint8_t key_size;
+
+	/**
+	 * Size of the stored values in log2 bits (0..6).
+	 * (6: 64 bit values, 5: 32 bit values, ...)
+	 */
+	uint8_t item_size_lg;
+
+	/**
+	 * Number of bits in the key that make a symbol for a node.
+	 * (equals to log2 of the child count of the node)
+	 */
+	uint8_t node_key_bits;
+
+	/**
+	 * Number of bits in the key that make a symbol for the data block (leaf).
+	 * (equals to log2 of the value count stored in a data block)
+	 */
+	uint8_t data_block_key_bits;
+
+	/** The depth of the data block. Calculated from the values above */
+	uint8_t max_depth;
+};
+
+struct trie* trie_create(uint8_t key_size, uint8_t item_size_lg,
+			uint8_t node_key_bits, uint8_t data_block_key_bits,
+			uint64_t empty_value);
+
+bool trie_set(struct trie *t, uint64_t key, uint64_t val);
+uint64_t trie_get(struct trie *t, uint64_t key);
+
+typedef void (*trie_iterate_fn)(void *data, uint64_t key, uint64_t val);
+
+/**
+ * Calls trie_iterate_fn for each key-value pair where
+ * key is inside the [start, end] interval (inclusive).
+ *
+ * @param t        The trie.
+ * @param start    The start of the key interval (inclusive).
+ * @param end      The end of the key interval (inclusive).
+ * @param fn       The function to be called.
+ * @param fn_data  The value to be passed to fn.
+ */
+uint64_t trie_iterate_keys(struct trie *t, uint64_t start, uint64_t end,
+			    trie_iterate_fn fn, void *fn_data);
+
+void trie_free(struct trie *t);
+
+#endif /* !STRACE_TRIE_H */
-- 
2.27.0


From uzonyi.akos at gmail.com  Sat Aug  8 21:14:34 2020
From: uzonyi.akos at gmail.com (=?UTF-8?q?=C3=81kos=20Uzonyi?=)
Date: Sat,  8 Aug 2020 23:14:34 +0200
Subject: [PATCH v7 2/5] Use printpid in decoders
In-Reply-To: <20200808211437.469898-1-uzonyi.akos@gmail.com>
References: <20200808211437.469898-1-uzonyi.akos@gmail.com>
Message-ID: <20200808211437.469898-3-uzonyi.akos@gmail.com>

* getpid.c: New file.
* Makefile.am (libstrace_a_SOURCES): Add it.
* linux/dummy.h (sys_getpid, sys_getppid, sys_gettid,
sys_setpgid, sys_setpgrp): Remove.
* util.c (printfd_pid_tracee_ns): Implement using translate_pid.
* defs.h (printnum_pid): New function definition.
(printfd_pid_tracee_ns): Update documentation
* util.c: (printnum_pid): New function.
* print_fields.h (PRINT_FIELD_TID): New macro.
(PRINT_FIELD_TGID): Likewise.
(PRINT_FIELD_PGID): Likewise.
(PRINT_FIELD_SID): Likewise.
* affinity.c: Print PIDs with printpid.
* block.c: Likewise.
* bpf.c: Likewise.
* capability.c: Likewise.
* clone.c: Likewise.
* fcntl.c: Likewise.
* get_robust_list.c: Likewise.
* ioprio.c: Likewise.
* kcmp.c: Likewise.
* msghdr.c: Likewise.
* net.c: Likewise.
* netlink.c: Likewise.
* numa.c: Likewise.
* pidfd_open.c: Likewise.
* printsiginfo.c: Likewise.
* process.c: Likewise.
* process_vm.c: Likewise.
* resource.c: Likewise.
* sched.c: Likewise.
* signal.c: Likewise.
* sockaddr.c: Likewise.
* wait.c: Likewise.
* kcmp.c (SYS_FUNC(kcmp)): Fix KCMP_FILE pid arguments.
* tests/kcmp.c (printpidfd): Print path if VERBOSE_FD.
(main): Use our real pid if real fds are used.
---
 Makefile.am       |  1 +
 affinity.c        |  6 ++++--
 block.c           |  2 +-
 bpf.c             |  2 +-
 capability.c      |  4 +++-
 clone.c           | 14 +++++++-------
 defs.h            |  5 ++++-
 fcntl.c           | 24 ++++++++++++++++++++++--
 get_robust_list.c |  3 ++-
 getpid.c          | 46 ++++++++++++++++++++++++++++++++++++++++++++++
 ioprio.c          | 26 ++++++++++++++++++++++----
 ipc_shmctl.c      |  4 ++--
 kcmp.c            |  5 ++++-
 linux/dummy.h     |  8 +-------
 msghdr.c          |  2 +-
 net.c             |  2 +-
 netlink.c         |  5 +++--
 numa.c            |  6 ++++--
 pidfd_open.c      |  2 +-
 print_fields.h    | 24 ++++++++++++++++++++++++
 printsiginfo.c    |  2 +-
 process.c         |  3 ++-
 process_vm.c      |  6 ++++--
 resource.c        | 27 ++++++++++++++++++++++++---
 sched.c           | 25 ++++++++++++++++---------
 signal.c          | 21 +++++++++++++++------
 sockaddr.c        |  2 +-
 tests/kcmp.c      | 25 ++++++++++++++++++++++---
 util.c            | 20 ++++++++++++++------
 wait.c            | 36 ++++++++++++++++++++++++------------
 30 files changed, 277 insertions(+), 81 deletions(-)
 create mode 100644 getpid.c

diff --git a/Makefile.am b/Makefile.am
index 73c22035..15fcd9a6 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -135,6 +135,7 @@ libstrace_a_SOURCES =	\
 	getcpu.c	\
 	getcwd.c	\
 	getpagesize.c \
+	getpid.c	\
 	getrandom.c	\
 	hdio.c		\
 	hostname.c	\
diff --git a/affinity.c b/affinity.c
index eb3158b7..f9893adb 100644
--- a/affinity.c
+++ b/affinity.c
@@ -82,7 +82,8 @@ SYS_FUNC(sched_setaffinity)
 	const int pid = tcp->u_arg[0];
 	const unsigned int len = tcp->u_arg[1];
 
-	tprintf("%d, %u, ", pid, len);
+	printpid(tcp, pid, PT_TGID);
+	tprintf(", %u, ", len);
 	print_affinitylist(tcp, tcp->u_arg[2], len);
 
 	return RVAL_DECODED;
@@ -94,7 +95,8 @@ SYS_FUNC(sched_getaffinity)
 	const unsigned int len = tcp->u_arg[1];
 
 	if (entering(tcp)) {
-		tprintf("%d, %u, ", pid, len);
+		printpid(tcp, pid, PT_TGID);
+		tprintf(", %u, ", len);
 	} else {
 		print_affinitylist(tcp, tcp->u_arg[2], tcp->u_rval);
 	}
diff --git a/block.c b/block.c
index b527ef43..783a4b5a 100644
--- a/block.c
+++ b/block.c
@@ -179,7 +179,7 @@ MPERS_PRINTER_DECL(int, block_ioctl, struct tcb *const tcp,
 			PRINT_FIELD_U(", ", buts, buf_nr);
 			PRINT_FIELD_U(", ", buts, start_lba);
 			PRINT_FIELD_U(", ", buts, end_lba);
-			PRINT_FIELD_D(", ", buts, pid);
+			PRINT_FIELD_TGID(", ", buts, pid, tcp);
 			return 0;
 		} else {
 			struct_blk_user_trace_setup buts;
diff --git a/bpf.c b/bpf.c
index af830053..0ec33ba4 100644
--- a/bpf.c
+++ b/bpf.c
@@ -927,7 +927,7 @@ BEGIN_BPF_CMD_DECODER(BPF_TASK_FD_QUERY)
 	if (entering(tcp)) {
 		set_tcb_priv_ulong(tcp, attr.buf_len);
 
-		PRINT_FIELD_D("{task_fd_query={", attr, pid);
+		PRINT_FIELD_TGID("{task_fd_query={", attr, pid, tcp);
 		PRINT_FIELD_FD(", ", attr, fd, tcp);
 		PRINT_FIELD_U(", ", attr, flags);
 		PRINT_FIELD_U(", ", attr, buf_len);
diff --git a/capability.c b/capability.c
index 0e763ee1..812fb435 100644
--- a/capability.c
+++ b/capability.c
@@ -70,7 +70,9 @@ print_cap_header(struct tcb *const tcp, const kernel_ulong_t addr,
 	tprints("{version=");
 	printxval(cap_version, h->version,
 		  "_LINUX_CAPABILITY_VERSION_???");
-	tprintf(", pid=%d}", h->pid);
+	tprints(", pid=");
+	printpid(tcp, h->pid, PT_TGID);
+	tprints("}");
 }
 
 static void
diff --git a/clone.c b/clone.c
index 487c5c23..45f24065 100644
--- a/clone.c
+++ b/clone.c
@@ -114,14 +114,14 @@ SYS_FUNC(clone)
 		 */
 		if ((flags & (CLONE_PARENT_SETTID|CLONE_PIDFD|CLONE_CHILD_SETTID
 			      |CLONE_CHILD_CLEARTID|CLONE_SETTLS)) == 0)
-			return RVAL_DECODED;
+			return RVAL_DECODED | RVAL_TID;
 	} else {
 		if (flags & (CLONE_PARENT_SETTID|CLONE_PIDFD)) {
 			kernel_ulong_t addr = tcp->u_arg[ARG_PTID];
 
 			tprints(", parent_tid=");
 			if (flags & CLONE_PARENT_SETTID)
-				printnum_int(tcp, addr, "%u");
+				printnum_pid(tcp, addr, PT_TID);
 			else
 				printnum_fd(tcp, addr);
 		}
@@ -134,7 +134,7 @@ SYS_FUNC(clone)
 			printaddr(tcp->u_arg[ARG_CTID]);
 		}
 	}
-	return 0;
+	return RVAL_TID;
 }
 
 
@@ -229,7 +229,7 @@ SYS_FUNC(clone3)
 
 		if ((arg.flags & (CLONE_PIDFD | CLONE_PARENT_SETTID)) ||
 		    (size > fetch_size))
-			return 0;
+			return RVAL_TID;
 
 		goto out;
 	}
@@ -256,7 +256,7 @@ SYS_FUNC(clone3)
 
 	if (arg.flags & CLONE_PARENT_SETTID) {
 		tprintf("%sparent_tid=", pfx);
-		printnum_int(tcp, arg.parent_tid, "%d"); /* TID */
+		printnum_pid(tcp, arg.parent_tid, PT_TID);
 		pfx = ", ";
 	}
 
@@ -279,7 +279,7 @@ SYS_FUNC(clone3)
 out:
 	tprintf(", %" PRI_klu, size);
 
-	return RVAL_DECODED;
+	return RVAL_DECODED | RVAL_TID;
 }
 
 
@@ -300,5 +300,5 @@ SYS_FUNC(unshare)
 
 SYS_FUNC(fork)
 {
-	return RVAL_DECODED;
+	return RVAL_DECODED | RVAL_TGID;
 }
diff --git a/defs.h b/defs.h
index ea77f1ff..f7a0a01d 100644
--- a/defs.h
+++ b/defs.h
@@ -1099,7 +1099,7 @@ printfd(struct tcb *tcp, int fd)
 
 /**
  * Print file descriptor fd owned by process with ID pid (from the PID NS
- * of the tracee the descriptor tcp).  This is a stub.
+ * of the tracee).
  */
 extern void printfd_pid_tracee_ns(struct tcb *tcp, pid_t pid, int fd);
 
@@ -1560,6 +1560,9 @@ DECL_PRINTNUM_ADDR(int64);
 extern bool
 printnum_fd(struct tcb *, kernel_ulong_t addr);
 
+extern bool
+printnum_pid(struct tcb *const tcp, const kernel_ulong_t addr, enum pid_type type);
+
 static inline bool
 printnum_slong(struct tcb *tcp, kernel_ulong_t addr)
 {
diff --git a/fcntl.c b/fcntl.c
index 6fcd5dac..5c630a06 100644
--- a/fcntl.c
+++ b/fcntl.c
@@ -28,7 +28,7 @@ print_struct_flock64(struct tcb *const tcp, const struct_kernel_flock64 *fl, con
 	PRINT_FIELD_D(", ", *fl, l_start);
 	PRINT_FIELD_D(", ", *fl, l_len);
 	if (getlk)
-		PRINT_FIELD_D(", ", *fl, l_pid);
+		PRINT_FIELD_TGID(", ", *fl, l_pid, tcp);
 	tprints("}");
 }
 
@@ -59,7 +59,22 @@ print_f_owner_ex(struct tcb *const tcp, const kernel_ulong_t addr)
 		return;
 
 	PRINT_FIELD_XVAL("{", owner, type, f_owner_types, "F_OWNER_???");
-	PRINT_FIELD_D(", ", owner, pid);
+
+	enum pid_type pid_type = PT_NONE;
+	switch (owner.type)
+	{
+	case F_OWNER_TID:
+		pid_type = PT_TID;
+		break;
+	case F_OWNER_PID:
+		pid_type = PT_TGID;
+		break;
+	case F_OWNER_PGRP:
+		pid_type = PT_PGID;
+		break;
+	}
+	tprints(", pid=");
+	printpid(tcp, owner.pid, pid_type);
 	tprints("}");
 }
 
@@ -74,6 +89,9 @@ print_fcntl(struct tcb *tcp)
 		printflags(fdflags, tcp->u_arg[2], "FD_???");
 		break;
 	case F_SETOWN:
+		tprints(", ");
+		printpid_tgid_pgid(tcp, tcp->u_arg[2]);
+		break;
 	case F_SETPIPE_SZ:
 		tprintf(", %" PRI_kld, tcp->u_arg[2]);
 		break;
@@ -116,6 +134,8 @@ print_fcntl(struct tcb *tcp)
 		printsignal(tcp->u_arg[2]);
 		break;
 	case F_GETOWN:
+		return RVAL_DECODED |
+		       ((int) tcp->u_rval < 0 ? RVAL_PGID : RVAL_TGID);
 	case F_GETPIPE_SZ:
 		break;
 	case F_GETFD:
diff --git a/get_robust_list.c b/get_robust_list.c
index b5aebaff..81aba2dd 100644
--- a/get_robust_list.c
+++ b/get_robust_list.c
@@ -10,7 +10,8 @@
 SYS_FUNC(get_robust_list)
 {
 	if (entering(tcp)) {
-		tprintf("%d, ", (int) tcp->u_arg[0]);
+		printpid(tcp, tcp->u_arg[0], PT_TID);
+		tprints(", ");
 	} else {
 		printnum_ptr(tcp, tcp->u_arg[1]);
 		tprints(", ");
diff --git a/getpid.c b/getpid.c
new file mode 100644
index 00000000..5e9a1a29
--- /dev/null
+++ b/getpid.c
@@ -0,0 +1,46 @@
+/*
+ * Copyright (c) 2020 ?kos Uzonyi <uzonyi.akos at gmail.com>
+ * All rights reserved.
+ *
+ * SPDX-License-Identifier: LGPL-2.1-or-later
+ */
+
+#include "defs.h"
+
+SYS_FUNC(getpid)
+{
+	return RVAL_DECODED | RVAL_TGID;
+}
+
+SYS_FUNC(gettid)
+{
+	return RVAL_DECODED | RVAL_TID;
+}
+
+SYS_FUNC(getpgrp)
+{
+	return RVAL_DECODED | RVAL_PGID;
+}
+
+SYS_FUNC(getpgid)
+{
+	printpid(tcp, tcp->u_arg[0], PT_TGID);
+
+	return RVAL_DECODED | RVAL_PGID;
+}
+
+SYS_FUNC(getsid)
+{
+	printpid(tcp, tcp->u_arg[0], PT_TGID);
+
+	return RVAL_DECODED | RVAL_SID;
+}
+
+SYS_FUNC(setpgid)
+{
+	printpid(tcp, tcp->u_arg[0], PT_TGID);
+	tprints(", ");
+	printpid(tcp, tcp->u_arg[1], PT_PGID);
+
+	return RVAL_DECODED;
+}
diff --git a/ioprio.c b/ioprio.c
index 873c8ce5..149ef3fd 100644
--- a/ioprio.c
+++ b/ioprio.c
@@ -49,13 +49,30 @@ print_ioprio(unsigned int ioprio)
 		? tprints_comment : tprints)(str);
 }
 
+static void
+ioprio_print_who(struct tcb *tcp, int which, int who)
+{
+	switch (which)
+	{
+	case IOPRIO_WHO_PROCESS:
+		printpid(tcp, who, PT_TGID);
+		break;
+	case IOPRIO_WHO_PGRP:
+		printpid(tcp, who, PT_PGID);
+		break;
+	default:
+		tprintf("%d", who);
+		break;
+	}
+}
+
 SYS_FUNC(ioprio_get)
 {
 	if (entering(tcp)) {
 		/* int which */
 		printxval(ioprio_who, tcp->u_arg[0], "IOPRIO_WHO_???");
-		/* int who */
-		tprintf(", %d", (int) tcp->u_arg[1]);
+		tprints(", ");
+		ioprio_print_who(tcp, tcp->u_arg[0], tcp->u_arg[1]);
 		return 0;
 	} else {
 		if (syserror(tcp))
@@ -72,8 +89,9 @@ SYS_FUNC(ioprio_set)
 {
 	/* int which */
 	printxval(ioprio_who, tcp->u_arg[0], "IOPRIO_WHO_???");
-	/* int who */
-	tprintf(", %d, ", (int) tcp->u_arg[1]);
+	tprints(", ");
+	ioprio_print_who(tcp, tcp->u_arg[0], tcp->u_arg[1]);
+	tprints(", ");
 	/* int ioprio */
 	if (xlat_verbose(xlat_verbosity) != XLAT_STYLE_ABBREV)
 		tprintf("%d", (int) tcp->u_arg[2]);
diff --git a/ipc_shmctl.c b/ipc_shmctl.c
index 8c9e1e7a..1f99f02a 100644
--- a/ipc_shmctl.c
+++ b/ipc_shmctl.c
@@ -53,8 +53,8 @@ print_shmid_ds(struct tcb *const tcp, const kernel_ulong_t addr, int cmd)
 		PRINT_FIELD_UID(", ", shmid_ds.shm_perm, cgid);
 		tprints("}");
 		tprintf(", shm_segsz=%u", (unsigned) shmid_ds.shm_segsz);
-		PRINT_FIELD_D(", ", shmid_ds, shm_cpid);
-		PRINT_FIELD_D(", ", shmid_ds, shm_lpid);
+		PRINT_FIELD_TGID(", ", shmid_ds, shm_cpid, tcp);
+		PRINT_FIELD_TGID(", ", shmid_ds, shm_lpid, tcp);
 		tprintf(", shm_nattch=%u", (unsigned) shmid_ds.shm_nattch);
 		tprintf(", shm_atime=%u", (unsigned) shmid_ds.shm_atime);
 		tprintf(", shm_dtime=%u", (unsigned) shmid_ds.shm_dtime);
diff --git a/kcmp.c b/kcmp.c
index 62115555..a5e1cdce 100644
--- a/kcmp.c
+++ b/kcmp.c
@@ -30,7 +30,10 @@ SYS_FUNC(kcmp)
 	kernel_ulong_t idx1 = tcp->u_arg[3];
 	kernel_ulong_t idx2 = tcp->u_arg[4];
 
-	tprintf("%d, %d, ", pid1, pid2);
+	printpid(tcp, pid1, PT_TGID);
+	tprints(", ");
+	printpid(tcp, pid2, PT_TGID);
+	tprints(", ");
 	printxval(kcmp_types, type, "KCMP_???");
 
 	switch (type) {
diff --git a/linux/dummy.h b/linux/dummy.h
index 2f859a60..ca0d2f0c 100644
--- a/linux/dummy.h
+++ b/linux/dummy.h
@@ -53,6 +53,7 @@
 # define sys_getgid		sys_getuid
 # define sys_getgid16		sys_getuid16
 # define sys_getpeername		sys_getsockname
+# define sys_getppid		sys_getpid
 # define sys_getresgid		sys_getresuid
 # define sys_getresgid16		sys_getresuid16
 # define sys_lstat		sys_stat
@@ -87,10 +88,6 @@
 # define sys_vfork		sys_fork
 
 /* printargs does the right thing */
-# define sys_getpgrp		printargs
-# define sys_getpid		printargs
-# define sys_getppid		printargs
-# define sys_gettid		printargs
 # define sys_idle		printargs
 # define sys_munlockall		printargs
 # define sys_pause		printargs
@@ -108,10 +105,7 @@
 
 /* printargs_d does the right thing */
 # define sys_exit		printargs_d
-# define sys_getpgid		printargs_d
-# define sys_getsid		printargs_d
 # define sys_nice		printargs_d
-# define sys_setpgid		printargs_d
 # define sys_setpgrp		printargs_d
 # define sys_timer_delete	printargs_d
 # define sys_timer_getoverrun	printargs_d
diff --git a/msghdr.c b/msghdr.c
index ef6dc24b..170b8e51 100644
--- a/msghdr.c
+++ b/msghdr.c
@@ -69,7 +69,7 @@ print_scm_creds(struct tcb *tcp, const void *cmsg_data,
 {
 	const struct ucred *uc = cmsg_data;
 
-	PRINT_FIELD_D("{", *uc, pid);
+	PRINT_FIELD_TGID("{", *uc, pid, tcp);
 	PRINT_FIELD_UID(", ", *uc, uid);
 	PRINT_FIELD_UID(", ", *uc, gid);
 	tprints("}");
diff --git a/net.c b/net.c
index fa4638e7..2099f0ac 100644
--- a/net.c
+++ b/net.c
@@ -601,7 +601,7 @@ print_get_ucred(struct tcb *const tcp, const kernel_ulong_t addr,
 	if (umoven_or_printaddr(tcp, addr, len, &uc))
 		return;
 
-	PRINT_FIELD_LEN("{", uc, pid, len, PRINT_FIELD_D);
+	PRINT_FIELD_LEN("{", uc, pid, len, PRINT_FIELD_TGID, tcp);
 	PRINT_FIELD_LEN(", ", uc, uid, len, PRINT_FIELD_UID);
 	PRINT_FIELD_LEN(", ", uc, gid, len, PRINT_FIELD_UID);
 	tprints("}");
diff --git a/netlink.c b/netlink.c
index 88d864a9..cb29033a 100644
--- a/netlink.c
+++ b/netlink.c
@@ -446,8 +446,9 @@ print_nlmsghdr(struct tcb *tcp,
 	decode_nlmsg_flags(nlmsghdr->nlmsg_flags,
 			   nlmsghdr->nlmsg_type, family);
 
-	tprintf(", seq=%u, pid=%d}", nlmsghdr->nlmsg_seq,
-		nlmsghdr->nlmsg_pid);
+	tprintf(", seq=%u, pid=", nlmsghdr->nlmsg_seq);
+	printpid(tcp, nlmsghdr->nlmsg_pid, PT_TGID);
+	tprints("}");
 }
 
 static bool
diff --git a/numa.c b/numa.c
index cc7a7cc6..f7a58266 100644
--- a/numa.c
+++ b/numa.c
@@ -44,7 +44,8 @@ print_nodemask(struct tcb *const tcp, const kernel_ulong_t addr,
 
 SYS_FUNC(migrate_pages)
 {
-	tprintf("%d, %" PRI_klu ", ", (int) tcp->u_arg[0], tcp->u_arg[1]);
+	printpid(tcp, tcp->u_arg[0], PT_TGID);
+	tprintf(", %" PRI_klu ", ", tcp->u_arg[1]);
 	print_nodemask(tcp, tcp->u_arg[2], tcp->u_arg[1]);
 	tprints(", ");
 	print_nodemask(tcp, tcp->u_arg[3], tcp->u_arg[1]);
@@ -170,7 +171,8 @@ SYS_FUNC(move_pages)
 	kernel_ulong_t buf;
 
 	if (entering(tcp)) {
-		tprintf("%d, %" PRI_klu ", ", (int) tcp->u_arg[0], npages);
+		printpid(tcp, tcp->u_arg[0], PT_TGID);
+		tprintf(", %" PRI_klu ", ", npages);
 		print_array(tcp, tcp->u_arg[2], npages, &buf, current_wordsize,
 			    tfetch_mem, print_addr, 0);
 		tprints(", ");
diff --git a/pidfd_open.c b/pidfd_open.c
index bbc7f617..cf05a110 100644
--- a/pidfd_open.c
+++ b/pidfd_open.c
@@ -10,7 +10,7 @@
 SYS_FUNC(pidfd_open)
 {
 	/* pid_t pid */
-	tprintf("%d", (int) tcp->u_arg[0]);
+	printpid(tcp, tcp->u_arg[0], PT_TGID);
 
 	/* unsigned int flags */
 	tprintf(", %#x", (unsigned int) tcp->u_arg[1]);
diff --git a/print_fields.h b/print_fields.h
index f9714115..33d4a458 100644
--- a/print_fields.h
+++ b/print_fields.h
@@ -263,6 +263,30 @@
 		printfd((tcp_), (where_).field_);			\
 	} while (0)
 
+# define PRINT_FIELD_TID(prefix_, where_, field_, tcp_)			\
+	do {								\
+		STRACE_PRINTF("%s%s=", (prefix_), #field_);		\
+		printpid((tcp_), (where_).field_, PT_TID);			\
+	} while (0)
+
+# define PRINT_FIELD_TGID(prefix_, where_, field_, tcp_)			\
+	do {								\
+		STRACE_PRINTF("%s%s=", (prefix_), #field_);		\
+		printpid((tcp_), (where_).field_, PT_TGID);			\
+	} while (0)
+
+# define PRINT_FIELD_PGID(prefix_, where_, field_, tcp_)			\
+	do {								\
+		STRACE_PRINTF("%s%s=", (prefix_), #field_);		\
+		printpid((tcp_), (where_).field_, PT_PGID);			\
+	} while (0)
+
+# define PRINT_FIELD_SID(prefix_, where_, field_, tcp_)			\
+	do {								\
+		STRACE_PRINTF("%s%s=", (prefix_), #field_);		\
+		printpid((tcp_), (where_).field_, PT_SID);			\
+	} while (0)
+
 # define PRINT_FIELD_STRN(prefix_, where_, field_, len_, tcp_)		\
 	do {								\
 		STRACE_PRINTF("%s%s=", (prefix_), #field_);		\
diff --git a/printsiginfo.c b/printsiginfo.c
index 8ed1e7ba..cb4cde4a 100644
--- a/printsiginfo.c
+++ b/printsiginfo.c
@@ -58,7 +58,7 @@
 static void
 printsigsource(struct tcb *tcp, const siginfo_t *sip)
 {
-	PRINT_FIELD_D(", ", *sip, si_pid);
+	PRINT_FIELD_TGID(", ", *sip, si_pid, tcp);
 	PRINT_FIELD_UID(", ", *sip, si_uid);
 }
 
diff --git a/process.c b/process.c
index a98c304e..d6ff255d 100644
--- a/process.c
+++ b/process.c
@@ -92,7 +92,8 @@ SYS_FUNC(ptrace)
 		}
 
 		/* pid */
-		tprintf(", %d", pid);
+		tprints(", ");
+		printpid(tcp, pid, PT_TGID);
 
 		/* addr */
 		switch (request) {
diff --git a/process_vm.c b/process_vm.c
index abee1e68..81d9b0f4 100644
--- a/process_vm.c
+++ b/process_vm.c
@@ -13,7 +13,8 @@ SYS_FUNC(process_vm_readv)
 {
 	if (entering(tcp)) {
 		/* arg 1: pid */
-		tprintf("%d, ", (int) tcp->u_arg[0]);
+		printpid(tcp, tcp->u_arg[0], PT_TGID);
+		tprints(", ");
 	} else {
 		kernel_ulong_t local_iovcnt = tcp->u_arg[2];
 		kernel_ulong_t remote_iovcnt = tcp->u_arg[4];
@@ -42,7 +43,8 @@ SYS_FUNC(process_vm_writev)
 	kernel_ulong_t flags = tcp->u_arg[5];
 
 	/* arg 1: pid */
-	tprintf("%d, ", (int) tcp->u_arg[0]);
+	printpid(tcp, tcp->u_arg[0], PT_TGID);
+	tprints(", ");
 	/* arg 2: local iov */
 	tprint_iov(tcp, local_iovcnt, tcp->u_arg[1], IOV_DECODE_STR);
 	/* arg 3: local iovcnt */
diff --git a/resource.c b/resource.c
index 53192ee9..070f4740 100644
--- a/resource.c
+++ b/resource.c
@@ -142,7 +142,8 @@ SYS_FUNC(setrlimit)
 SYS_FUNC(prlimit64)
 {
 	if (entering(tcp)) {
-		tprintf("%d, ", (int) tcp->u_arg[0]);
+		printpid(tcp, tcp->u_arg[0], PT_TGID);
+		tprints(", ");
 		printxval(resources, tcp->u_arg[1], "RLIMIT_???");
 		tprints(", ");
 		print_rlimit64(tcp, tcp->u_arg[2]);
@@ -179,10 +180,28 @@ SYS_FUNC(osf_getrusage)
 
 #include "xlat/priorities.h"
 
+static void
+priority_print_who(struct tcb *tcp, int which, int who)
+{
+	switch (which)
+	{
+	case PRIO_PROCESS:
+		printpid(tcp, who, PT_TGID);
+		break;
+	case PRIO_PGRP:
+		printpid(tcp, who, PT_PGID);
+		break;
+	default:
+		tprintf("%d", who);
+		break;
+	}
+}
+
 SYS_FUNC(getpriority)
 {
 	printxval(priorities, tcp->u_arg[0], "PRIO_???");
-	tprintf(", %d", (int) tcp->u_arg[1]);
+	tprints(", ");
+	priority_print_who(tcp, tcp->u_arg[0], tcp->u_arg[1]);
 
 	return RVAL_DECODED;
 }
@@ -190,7 +209,9 @@ SYS_FUNC(getpriority)
 SYS_FUNC(setpriority)
 {
 	printxval(priorities, tcp->u_arg[0], "PRIO_???");
-	tprintf(", %d, %d", (int) tcp->u_arg[1], (int) tcp->u_arg[2]);
+	tprints(", ");
+	priority_print_who(tcp, tcp->u_arg[0], tcp->u_arg[1]);
+	tprintf(", %d", (int) tcp->u_arg[2]);
 
 	return RVAL_DECODED;
 }
diff --git a/sched.c b/sched.c
index 788ef39b..ff427e48 100644
--- a/sched.c
+++ b/sched.c
@@ -21,7 +21,7 @@
 SYS_FUNC(sched_getscheduler)
 {
 	if (entering(tcp)) {
-		tprintf("%d", (int) tcp->u_arg[0]);
+		printpid(tcp, tcp->u_arg[0], PT_TGID);
 	} else if (!syserror(tcp)) {
 		tcp->auxstr = xlookup(schedulers, (kernel_ulong_t) tcp->u_rval);
 		return RVAL_STR;
@@ -31,7 +31,8 @@ SYS_FUNC(sched_getscheduler)
 
 SYS_FUNC(sched_setscheduler)
 {
-	tprintf("%d, ", (int) tcp->u_arg[0]);
+	printpid(tcp, tcp->u_arg[0], PT_TGID);
+	tprints(", ");
 	printxval(schedulers, tcp->u_arg[1], "SCHED_???");
 	tprints(", ");
 	printnum_int(tcp, tcp->u_arg[2], "%d");
@@ -41,16 +42,19 @@ SYS_FUNC(sched_setscheduler)
 
 SYS_FUNC(sched_getparam)
 {
-	if (entering(tcp))
-		tprintf("%d, ", (int) tcp->u_arg[0]);
-	else
+	if (entering(tcp)) {
+		printpid(tcp, tcp->u_arg[0], PT_TGID);
+		tprints(", ");
+	} else {
 		printnum_int(tcp, tcp->u_arg[1], "%d");
+	}
 	return 0;
 }
 
 SYS_FUNC(sched_setparam)
 {
-	tprintf("%d, ", (int) tcp->u_arg[0]);
+	printpid(tcp, tcp->u_arg[0], PT_TGID);
+	tprints(", ");
 	printnum_int(tcp, tcp->u_arg[1], "%d");
 
 	return RVAL_DECODED;
@@ -68,7 +72,8 @@ do_sched_rr_get_interval(struct tcb *const tcp,
 			 const print_obj_by_addr_fn print_ts)
 {
 	if (entering(tcp)) {
-		tprintf("%d, ", (int) tcp->u_arg[0]);
+		printpid(tcp, tcp->u_arg[0], PT_TGID);
+		tprints(", ");
 	} else {
 		if (syserror(tcp))
 			printaddr(tcp->u_arg[1]);
@@ -160,7 +165,8 @@ end:
 SYS_FUNC(sched_setattr)
 {
 	if (entering(tcp)) {
-		tprintf("%d, ", (int) tcp->u_arg[0]);
+		printpid(tcp, tcp->u_arg[0], PT_TGID);
+		tprints(", ");
 		print_sched_attr(tcp, tcp->u_arg[1], 0);
 	} else {
 		struct sched_attr attr;
@@ -179,7 +185,8 @@ SYS_FUNC(sched_setattr)
 SYS_FUNC(sched_getattr)
 {
 	if (entering(tcp)) {
-		tprintf("%d, ", (int) tcp->u_arg[0]);
+		printpid(tcp, tcp->u_arg[0], PT_TGID);
+		tprints(", ");
 	} else {
 		const unsigned int size = tcp->u_arg[2];
 
diff --git a/signal.c b/signal.c
index d5d59105..49b4ebd5 100644
--- a/signal.c
+++ b/signal.c
@@ -439,7 +439,8 @@ SYS_FUNC(sigprocmask)
 SYS_FUNC(kill)
 {
 	/* pid */
-	tprintf("%d, ", (int) tcp->u_arg[0]);
+	printpid_tgid_pgid(tcp, tcp->u_arg[0]);
+	tprints(", ");
 	/* signal */
 	printsignal(tcp->u_arg[1]);
 
@@ -448,7 +449,7 @@ SYS_FUNC(kill)
 
 SYS_FUNC(tkill)
 {
-	tprintf("%d", (int) tcp->u_arg[0]);
+	printpid(tcp, tcp->u_arg[0], PT_TID);
 	tprints(", ");
 	printsignal(tcp->u_arg[1]);
 
@@ -457,8 +458,12 @@ SYS_FUNC(tkill)
 
 SYS_FUNC(tgkill)
 {
-	/* tgid, tid */
-	tprintf("%d, %d, ", (int) tcp->u_arg[0], (int) tcp->u_arg[1]);
+	/* tgid */
+	printpid(tcp, tcp->u_arg[0], PT_TGID);
+	tprints(", ");
+	/* tid */
+	printpid(tcp, tcp->u_arg[1], PT_TID);
+	tprints(", ");
 	/* signal */
 	printsignal(tcp->u_arg[2]);
 
@@ -624,7 +629,8 @@ print_sigqueueinfo(struct tcb *const tcp, const int sig,
 
 SYS_FUNC(rt_sigqueueinfo)
 {
-	tprintf("%d, ", (int) tcp->u_arg[0]);
+	printpid(tcp, tcp->u_arg[0], PT_TGID);
+	tprints(", ");
 	print_sigqueueinfo(tcp, tcp->u_arg[1], tcp->u_arg[2]);
 
 	return RVAL_DECODED;
@@ -632,7 +638,10 @@ SYS_FUNC(rt_sigqueueinfo)
 
 SYS_FUNC(rt_tgsigqueueinfo)
 {
-	tprintf("%d, %d, ", (int) tcp->u_arg[0], (int) tcp->u_arg[1]);
+	printpid(tcp, tcp->u_arg[0], PT_TGID);
+	tprints(", ");
+	printpid(tcp, tcp->u_arg[1], PT_TID);
+	tprints(", ");
 	print_sigqueueinfo(tcp, tcp->u_arg[2], tcp->u_arg[3]);
 
 	return RVAL_DECODED;
diff --git a/sockaddr.c b/sockaddr.c
index b0046331..fb8887c2 100644
--- a/sockaddr.c
+++ b/sockaddr.c
@@ -416,7 +416,7 @@ print_sockaddr_data_nl(struct tcb *tcp, const void *const buf, const int addrlen
 {
 	const struct sockaddr_nl *const sa_nl = buf;
 
-	PRINT_FIELD_D("", *sa_nl, nl_pid);
+	PRINT_FIELD_TGID("", *sa_nl, nl_pid, tcp);
 	PRINT_FIELD_0X(", ", *sa_nl, nl_groups);
 }
 
diff --git a/tests/kcmp.c b/tests/kcmp.c
index a46da0ed..dc5ba9a4 100644
--- a/tests/kcmp.c
+++ b/tests/kcmp.c
@@ -64,7 +64,26 @@ static const char zero_path[] = "/dev/zero";
 static void
 printpidfd(const char *prefix, pid_t pid, unsigned fd)
 {
-	printf("%s%d", prefix, fd);
+	const char *path = NULL;
+
+# if VERBOSE_FD
+	if (pid == getpid()) {
+		switch (fd)
+		{
+		case NULL_FD:
+			path = null_path;
+			break;
+		case ZERO_FD:
+			path = zero_path;
+			break;
+		}
+	}
+# endif
+
+	if (path)
+		printf("%s%d<%s>", prefix, fd, path);
+	else
+		printf("%s%d", prefix, fd);
 }
 
 /*
@@ -179,7 +198,7 @@ main(void)
 	/* KCMP_FILE is the only type which has additional args */
 	do_kcmp(3141592653U, 2718281828U, ARG_STR(KCMP_FILE), bogus_idx1,
 		bogus_idx2);
-	do_kcmp(-1, -1, ARG_STR(KCMP_FILE), NULL_FD, ZERO_FD);
+	do_kcmp(getpid(), getpid(), ARG_STR(KCMP_FILE), NULL_FD, ZERO_FD);
 
 	/* Types without additional args */
 	do_kcmp(-1, -1, ARG_STR(KCMP_VM), bogus_idx1, bogus_idx2);
@@ -198,7 +217,7 @@ main(void)
 	for (i = 0; i < ARRAY_SIZE(slot_data); i++) {
 		memcpy(slot, slot_data + i, sizeof(*slot));
 
-		do_kcmp(getpid(), getppid(), ARG_STR(KCMP_EPOLL_TFD), NULL_FD,
+		do_kcmp(getpid(), -1, ARG_STR(KCMP_EPOLL_TFD), NULL_FD,
 			(uintptr_t) slot, 1);
 	}
 
diff --git a/util.c b/util.c
index 286c6903..094e5818 100644
--- a/util.c
+++ b/util.c
@@ -392,6 +392,18 @@ printnum_fd(struct tcb *const tcp, const kernel_ulong_t addr)
 	return true;
 }
 
+bool
+printnum_pid(struct tcb *const tcp, const kernel_ulong_t addr, enum pid_type type)
+{
+	int pid;
+	if (umove_or_printaddr(tcp, addr, &pid))
+		return false;
+	tprints("[");
+	printpid(tcp, pid, type);
+	tprints("]");
+	return true;
+}
+
 /**
  * Prints time to a (static internal) buffer and returns pointer to it.
  * Returns NULL if the provided time specification is not correct.
@@ -641,12 +653,8 @@ printed:
 void
 printfd_pid_tracee_ns(struct tcb *tcp, pid_t pid, int fd)
 {
-	/*
-	 * TODO: We want to have the same formatting as printfd here,
-	 *       but we should figure out first which process in strace's
-	 *       PID NS is referred to by pid in tracee's PID NS.
-	 */
-	tprintf("%d", fd);
+	int strace_pid = translate_pid(tcp, pid, PT_TGID, NULL);
+	printfd_pid(tcp, strace_pid, fd);
 }
 
 /*
diff --git a/wait.c b/wait.c
index 2b9f9807..177427c8 100644
--- a/wait.c
+++ b/wait.c
@@ -80,14 +80,8 @@ printwaitn(struct tcb *const tcp,
 	   void (*const print_rusage)(struct tcb *, kernel_ulong_t))
 {
 	if (entering(tcp)) {
-		/* On Linux, kernel-side pid_t is typedef'ed to int
-		 * on all arches. Also, glibc-2.8 truncates wait3 and wait4
-		 * pid argument to int on 64bit arches, producing,
-		 * for example, wait4(4294967295, ...) instead of -1
-		 * in strace. We have to use int here, not long.
-		 */
-		int pid = tcp->u_arg[0];
-		tprintf("%d, ", pid);
+		printpid_tgid_pgid(tcp, tcp->u_arg[0]);
+		tprintf(", ");
 	} else {
 		int status;
 
@@ -108,7 +102,7 @@ printwaitn(struct tcb *const tcp,
 				printaddr(tcp->u_arg[3]);
 		}
 	}
-	return 0;
+	return RVAL_TGID;
 }
 
 SYS_FUNC(waitpid)
@@ -134,10 +128,28 @@ SYS_FUNC(osf_wait4)
 
 SYS_FUNC(waitid)
 {
+	unsigned int idtype = (unsigned int) tcp->u_arg[0];
+	int id = tcp->u_arg[1];
+
 	if (entering(tcp)) {
-		printxval(waitid_types, tcp->u_arg[0], "P_???");
-		int pid = tcp->u_arg[1];
-		tprintf(", %d, ", pid);
+		printxval(waitid_types, idtype, "P_???");
+		tprints(", ");
+		switch (idtype)
+		{
+		case P_PID:
+			printpid(tcp, id, PT_TGID);
+			break;
+		case P_PIDFD:
+			printfd(tcp, id);
+			break;
+		case P_PGID:
+			printpid(tcp, id, PT_PGID);
+			break;
+		default:
+			tprintf("%d", id);
+			break;
+		}
+		tprints(", ");
 	} else {
 		/* siginfo */
 		printsiginfo_at(tcp, tcp->u_arg[2]);
-- 
2.27.0


From uzonyi.akos at gmail.com  Sat Aug  8 21:14:36 2020
From: uzonyi.akos at gmail.com (=?UTF-8?q?=C3=81kos=20Uzonyi?=)
Date: Sat,  8 Aug 2020 23:14:36 +0200
Subject: [PATCH v7 4/5] Implement testing framework for pidns
In-Reply-To: <20200808211437.469898-1-uzonyi.akos@gmail.com>
References: <20200808211437.469898-1-uzonyi.akos@gmail.com>
Message-ID: <20200808211437.469898-5-uzonyi.akos@gmail.com>

* tests/pidns.c: New file.
* tests/pidns.h: New file.
* tests/Makefile.am (libtests_a_SOURCES): Add pidns.c, pidns.h.
* tests/init.sh (test_pidns, test_pidns_run_strace): New functions.
---
 tests/Makefile.am |   2 +
 tests/init.sh     |  31 +++++++
 tests/pidns.c     | 214 ++++++++++++++++++++++++++++++++++++++++++++++
 tests/pidns.h     |  56 ++++++++++++
 4 files changed, 303 insertions(+)
 create mode 100644 tests/pidns.c
 create mode 100644 tests/pidns.h

diff --git a/tests/Makefile.am b/tests/Makefile.am
index 28d95e39..7a583a3a 100644
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@@ -44,6 +44,8 @@ libtests_a_SOURCES = \
 	libsocketcall.c \
 	lock_file.c \
 	overflowuid.c \
+	pidns.c \
+	pidns.h \
 	pipe_maxfd.c \
 	print_quoted_string.c \
 	print_time.c \
diff --git a/tests/init.sh b/tests/init.sh
index d78e697b..7325fa4a 100644
--- a/tests/init.sh
+++ b/tests/init.sh
@@ -387,6 +387,37 @@ test_prog_set()
 	test_pure_prog_set "$@" < "$srcdir/$NAME.in"
 }
 
+test_pidns_run_strace()
+{
+	local parent_pid
+
+	check_prog tail
+	check_prog cut
+	check_prog grep
+
+	run_prog > /dev/null
+	run_strace --pidns-translation -f $@ $args > "$EXP"
+
+	# filter out logs made by the parent or init process of the pidns test
+	parent_pid="$(tail -n 2 $LOG | head -n 1 | cut -d' ' -f1)"
+	init_pid="$(tail -n 1 $LOG | cut -d' ' -f1)"
+	grep -E -v "^($parent_pid|$init_pid) " "$LOG" > "$OUT"
+	match_diff "$OUT" "$EXP"
+}
+
+test_pidns()
+{
+	# ioctl(NS_GET_PARENT) is added in Linux 4.9
+	require_min_kernel_version_or_skip 4.9
+	check_prog unshare
+
+	test_pidns_run_strace "$@"
+
+	# test PID translation when /proc is mounted from an other namespace
+	STRACE="unshare -Urpf $STRACE"
+	test_pidns_run_strace "$@"
+}
+
 check_prog cat
 check_prog rm
 
diff --git a/tests/pidns.c b/tests/pidns.c
new file mode 100644
index 00000000..f54af340
--- /dev/null
+++ b/tests/pidns.c
@@ -0,0 +1,214 @@
+/*
+ * Testing framework for PID namespace translation
+ *
+ * Copyright (c) 2020 ?kos Uzonyi <uzonyi.akos at gmail.com>
+ * All rights reserved.
+ *
+ * SPDX-License-Identifier: LGPL-2.1-or-later
+ */
+#include "tests.h"
+#include "pidns.h"
+#include "nsfs.h"
+
+#include <errno.h>
+#include <stdio.h>
+#include <string.h>
+#include <sys/types.h>
+#include <signal.h>
+#include <stdlib.h>
+#include <sched.h>
+#include <unistd.h>
+#include <sys/wait.h>
+#include <linux/sched.h>
+#include <fcntl.h>
+#include <sys/ioctl.h>
+
+static bool pidns_translation = false;
+static bool pidns_unshared = false;
+
+/* Our PIDs in strace's namespace */
+static pid_t pidns_strace_ids[PT_COUNT];
+
+void
+pidns_print_leader(void)
+{
+	if (pidns_translation)
+		printf("%-5d ", pidns_strace_ids[PT_TID]);
+}
+
+const char *
+pidns_pid2str(enum pid_type type)
+{
+	static const char format[] = " /* %d in strace's PID NS */";
+	static char buf[PT_COUNT][sizeof(format) + sizeof(int) * 3];
+
+	if (type < 0 || type >= PT_COUNT)
+		return "";
+
+	if (!pidns_unshared || !pidns_strace_ids[type])
+		return "";
+
+	snprintf(buf[type], sizeof(buf[type]), format, pidns_strace_ids[type]);
+	return buf[type];
+}
+
+/**
+ * This function is like fork, but does a few more things. It sets up the
+ * child's PGID and SID according to the parameters. Also it fills the
+ * pidns_strace_ids array in the child's memory with the PIDs of the child in
+ * parent's PID namespace. In the parent it waits for the child to terminate
+ * (but leaves the zombie to use it later as a process group). If the child
+ * terminates with nonzero exit status, the test is failed.
+ *
+ * @param pgid     The process group the child should be moved to. It's expected
+ *                 to be a PID of a zombie process (will be reaped). If
+ *                 negative, leave the child in the process group of the parent.
+ *                 If 0, move the process to its own process group.
+ * @param new_sid  Wheather child should be moved to a new session.
+ */
+static pid_t
+pidns_fork(pid_t pgid, bool new_sid)
+{
+	int strace_ids_pipe[2];
+	if (pipe(strace_ids_pipe) < 0)
+		perror_msg_and_fail("pipe");
+
+	fflush(stdout);
+	pid_t pid = fork();
+	if (pid < 0)
+		perror_msg_and_fail("fork");
+
+	if (!pid) {
+		close(strace_ids_pipe[1]);
+		if (read(strace_ids_pipe[0], pidns_strace_ids,
+		    sizeof(pidns_strace_ids)) < 0)
+			perror_msg_and_fail("read");
+		close(strace_ids_pipe[0]);
+
+		if (pidns_strace_ids[PT_SID])
+			setsid();
+
+		return 0;
+	}
+
+	pidns_strace_ids[PT_TID] = pid;
+	pidns_strace_ids[PT_TGID] = pid;
+	pidns_strace_ids[PT_PGID] = 0;
+	pidns_strace_ids[PT_SID] = 0;
+
+	if (!pgid)
+		pgid = pid;
+
+	if (pgid > 0) {
+		if (setpgid(pid, pgid) < 0)
+			perror_msg_and_fail("setpgid");
+
+		pidns_strace_ids[PT_PGID] = pgid;
+	}
+
+	/* Reap group leader to test PGID decoding */
+	if (pgid > 0 && pgid != pid) {
+		int ret = waitpid(pgid, NULL, WNOHANG);
+		if (ret < 0)
+			perror_msg_and_fail("wait");
+		if (!ret)
+			error_msg_and_fail("could not reap group leader");
+	}
+
+	if (new_sid) {
+		pidns_strace_ids[PT_SID] = pid;
+		pidns_strace_ids[PT_PGID] = pid;
+	}
+
+	if (write(strace_ids_pipe[1], pidns_strace_ids,
+	    sizeof(pidns_strace_ids)) < 0)
+		perror_msg_and_fail("write");
+	close(strace_ids_pipe[0]);
+	close(strace_ids_pipe[1]);
+
+	/* WNOWAIT: leave the zombie, to be able to use it as a process group */
+	siginfo_t siginfo;
+	if (waitid(P_PID, pid, &siginfo, WEXITED | WNOWAIT) < 0)
+		perror_msg_and_fail("wait");
+	if (siginfo.si_code != CLD_EXITED || siginfo.si_status)
+		error_msg_and_fail("child terminated with nonzero exit status");
+
+	return pid;
+}
+
+static void
+create_init_process(void)
+{
+	int child_pipe[2];
+	if (pipe(child_pipe) < 0)
+		perror_msg_and_fail("pipe");
+
+	pid_t pid = fork();
+	if (pid < 0)
+		perror_msg_and_fail("fork");
+
+	if (!pid) {
+		close(child_pipe[1]);
+		_exit(read(child_pipe[0], &child_pipe[1], sizeof(int)) == 0);
+	}
+
+	close(child_pipe[0]);
+}
+
+void
+check_ns_ioctl(void)
+{
+	int fd = open("/proc/self/ns/pid", O_RDONLY);
+	if (fd < 0)
+		perror_msg_and_fail("opening /proc/self/ns/pid");
+
+	int userns_fd = ioctl(fd, NS_GET_USERNS);
+	if (userns_fd < 0) {
+		if (errno == ENOTTY)
+			error_msg_and_skip("NS_* ioctl commands are not "
+			                   "supported by the kernel");
+		else
+			perror_msg_and_fail("ioctl(NS_GET_USERNS)");
+	}
+
+	close(userns_fd);
+	close(fd);
+}
+
+void
+pidns_test_init(void)
+{
+	pidns_translation = true;
+
+	check_ns_ioctl();
+
+	if (!pidns_fork(-1, false))
+		return;
+
+	/* Unshare user namespace too, so we do not need to be root */
+	if (unshare(CLONE_NEWUSER | CLONE_NEWPID) < 0) {
+		if (errno == EPERM)
+			perror_msg_and_skip("unshare");
+
+		perror_msg_and_fail("unshare");
+	}
+
+	pidns_unshared = true;
+
+	create_init_process();
+
+	if (!pidns_fork(-1, false))
+		return;
+
+	if (!pidns_fork(-1, true))
+		return;
+
+	pid_t pgid;
+	if (!(pgid = pidns_fork(0, false)))
+		return;
+
+	if (!pidns_fork(pgid, false))
+		return;
+
+	exit(0);
+}
diff --git a/tests/pidns.h b/tests/pidns.h
new file mode 100644
index 00000000..76963eb3
--- /dev/null
+++ b/tests/pidns.h
@@ -0,0 +1,56 @@
+/*
+ * Test PID namespace translation
+ *
+ * Copyright (c) 2020 ?kos Uzonyi <uzonyi.akos at gmail.com>
+ * All rights reserved.
+ *
+ * SPDX-License-Identifier: LGPL-2.1-or-later
+ */
+#ifndef STRACE_PIDNS_H
+#define STRACE_PIDNS_H
+
+#ifdef PIDNS_TRANSLATION
+# define PIDNS_TEST_INIT pidns_test_init()
+#else
+# define PIDNS_TEST_INIT
+#endif
+
+#include <sys/types.h>
+
+enum pid_type {
+	PT_TID,
+	PT_TGID,
+	PT_PGID,
+	PT_SID,
+
+	PT_COUNT,
+	PT_NONE = -1
+};
+
+/* Prints leader (process tid) if pidns_test_init was called */
+void pidns_print_leader(void);
+
+/*
+ * Returns a static buffer containing the translation string of our PID.
+ */
+const char *pidns_pid2str(enum pid_type type);
+
+/**
+ * Skips the test if NS_* ioctl commands are not supported by the kernel.
+ */
+void check_ns_ioctl(void);
+
+/**
+ * Init pidns testing.
+ *
+ * Should be called at the beginning of the test's main function
+ *
+ * This function calls fork a couple of times, and returns in the child
+ * processes. These child processes are in a new PID namespace with different
+ * PID configurations (group leader, session leader, ...). If any child
+ * terminates with nonzero exit status the test is failed. Otherwise the test is
+ * succesful, and the parent process exits with 0.
+ */
+void pidns_test_init(void);
+
+#endif
\ No newline at end of file
-- 
2.27.0


From uzonyi.akos at gmail.com  Sat Aug  8 21:14:35 2020
From: uzonyi.akos at gmail.com (=?UTF-8?q?=C3=81kos=20Uzonyi?=)
Date: Sat,  8 Aug 2020 23:14:35 +0200
Subject: [PATCH v7 3/5] Use get_proc_pid for /proc paths
In-Reply-To: <20200808211437.469898-1-uzonyi.akos@gmail.com>
References: <20200808211437.469898-1-uzonyi.akos@gmail.com>
Message-ID: <20200808211437.469898-4-uzonyi.akos@gmail.com>

* mmap_cache.c (mmap_cache_rebuild_if_invalid): Use proc pid instead of
tcp->pid for /proc path.
* util.c (getfdproto): Likewise.
(pidfd_get_pid): Likewise.
* pathtrace.c (getfdpath_pid): Likewise.
* strace.c (attach_tcb): Likewise.
---
 mmap_cache.c | 2 +-
 pathtrace.c  | 5 ++++-
 strace.c     | 2 +-
 util.c       | 7 +++++--
 4 files changed, 11 insertions(+), 5 deletions(-)

diff --git a/mmap_cache.c b/mmap_cache.c
index 89c62254..9825df26 100644
--- a/mmap_cache.c
+++ b/mmap_cache.c
@@ -84,7 +84,7 @@ mmap_cache_rebuild_if_invalid(struct tcb *tcp, const char *caller)
 		return MMAP_CACHE_REBUILD_READY;
 
 	char filename[sizeof("/proc/4294967296/maps")];
-	xsprintf(filename, "/proc/%u/maps", tcp->pid);
+	xsprintf(filename, "/proc/%u/maps", get_proc_pid(tcp));
 
 	FILE *fp = fopen_stream(filename, "r");
 	if (!fp) {
diff --git a/pathtrace.c b/pathtrace.c
index 5b60762b..74717a8a 100644
--- a/pathtrace.c
+++ b/pathtrace.c
@@ -87,7 +87,10 @@ getfdpath_pid(pid_t pid, int fd, char *buf, unsigned bufsize)
 	if (fd < 0)
 		return -1;
 
-	xsprintf(linkpath, "/proc/%u/fd/%u", pid, fd);
+	int proc_pid = 0;
+	translate_pid(NULL, pid, PT_TID, &proc_pid);
+
+	xsprintf(linkpath, "/proc/%u/fd/%u", proc_pid, fd);
 	n = readlink(linkpath, buf, bufsize - 1);
 	/*
 	 * NB: if buf is too small, readlink doesn't fail,
diff --git a/strace.c b/strace.c
index 249533ea..ef23f08f 100644
--- a/strace.c
+++ b/strace.c
@@ -1196,7 +1196,7 @@ attach_tcb(struct tcb *const tcp)
 	unsigned int ntid = 0, nerr = 0;
 
 	if (followfork && tcp->pid != strace_child &&
-	    xsprintf(procdir, task_path, tcp->pid) > 0 &&
+	    xsprintf(procdir, task_path, get_proc_pid(tcp)) > 0 &&
 	    (dir = opendir(procdir)) != NULL) {
 		struct_dirent *de;
 
diff --git a/util.c b/util.c
index 094e5818..d87d022e 100644
--- a/util.c
+++ b/util.c
@@ -501,7 +501,7 @@ getfdproto(struct tcb *tcp, int fd)
 	if (fd < 0)
 		return SOCK_PROTO_UNKNOWN;
 
-	xsprintf(path, "/proc/%u/fd/%u", tcp->pid, fd);
+	xsprintf(path, "/proc/%u/fd/%u", get_proc_pid(tcp), fd);
 	r = getxattr(path, "system.sockprotoname", buf, bufsize - 1);
 	if (r <= 0)
 		return SOCK_PROTO_UNKNOWN;
@@ -582,8 +582,11 @@ printdev(struct tcb *tcp, int fd, const char *path)
 pid_t
 pidfd_get_pid(pid_t pid_of_fd, int fd)
 {
+	int proc_pid = 0;
+	translate_pid(NULL, pid_of_fd, PT_TID, &proc_pid);
+
 	char fdi_path[sizeof("/proc/%u/fdinfo/%u") + 2 * sizeof(int) * 3];
-	xsprintf(fdi_path, "/proc/%u/fdinfo/%u", pid_of_fd, fd);
+	xsprintf(fdi_path, "/proc/%u/fdinfo/%u", proc_pid, fd);
 
 	FILE *f = fopen_stream(fdi_path, "r");
 	if (!f)
-- 
2.27.0


From uzonyi.akos at gmail.com  Sat Aug  8 21:14:37 2020
From: uzonyi.akos at gmail.com (=?UTF-8?q?=C3=81kos=20Uzonyi?=)
Date: Sat,  8 Aug 2020 23:14:37 +0200
Subject: [PATCH v7 5/5] Add tests for PID namespace translation
In-Reply-To: <20200808211437.469898-1-uzonyi.akos@gmail.com>
References: <20200808211437.469898-1-uzonyi.akos@gmail.com>
Message-ID: <20200808211437.469898-6-uzonyi.akos@gmail.com>

* tests/.gitignore: Add new test executables.
* tests/Makefile.am (check_PROGRAMS): Add new test executables.
(DECODER_TESTS) Add new test files.
* tests/gen_tests.in: Add new tests.
* tests/fcntl--pidns-translation.c: New file.
* tests/fcntl64--pidns-translation.c: New file.
* tests/fork--pidns-translation.awk: New file.
* tests/fork--pidns-translation.c: New file.
* tests/fork--pidns-translation.test: New file.
* tests/getpgrp--pidns-translation.c: New file.
* tests/getpid--pidns-translation.c: New file.
* tests/getsid--pidns-translation.c: New file.
* tests/gettid--pidns-translation.c: New file.
* tests/gettid--pidns-translation.test: New file.
* tests/ioctl_block--pidns-translation.c: New file.
* tests/ioctl_block--pidns-translation.test: New file.
* tests/ioprio--pidns-translation.c: New file.
* tests/kill--pidns-translation.c: New file.
* tests/migrate_pages--pidns-translation.c: New file.
* tests/move_pages--pidns-translation.c: New file.
* tests/net-sockaddr--pidns-translation.c: New file.
* tests/netlink_audit--pidns-translation.c: New file.
* tests/netlink_audit--pidns-translation.test: New file.
* tests/pidfd_open--pidns-translation.c: New file.
* tests/pidfd_send_signal--pidns-translation.c: New file.
* tests/prlimit64--pidns-translation.c: New file.
* tests/process_vm_readv--pidns-translation.c: New file.
* tests/process_vm_writev--pidns-translation.c: New file.
* tests/rt_sigqueueinfo--pidns-translation.c: New file.
* tests/rt_tgsigqueueinfo--pidns-translation.c: New file.
* tests/sched_xetaffinity--pidns-translation.c: New file.
* tests/sched_xetattr--pidns-translation.c: New file.
* tests/sched_xetparam--pidns-translation.c: New file.
* tests/sched_xetscheduler--pidns-translation.c: New file.
* tests/signal_receive--pidns-translation.c: New file.
* tests/so_peercred--pidns-translation.c: New file.
* tests/xet_robust_list--pidns-translation.c: New file.
* tests/xetpgid--pidns-translation.c: New file.
* tests/xetpriority--pidns-translation.c: New file.
* tests/fcntl-common.c: Print PID translation string after PIDs.
* tests/fcntl.c: Likewise.
* tests/fcntl64.c: Likewise.
* tests/getpgrp.c: Likewise.
* tests/getpid.c: Likewise.
* tests/getsid.c: Likewise.
* tests/gettid.c: Likewise.
* tests/ioctl_block.c: Likewise.
* tests/ioprio.c: Likewise.
* tests/kcmp.c: Likewise.
* tests/kill.c: Likewise.
* tests/migrate_pages.c: Likewise.
* tests/move_pages.c: Likewise.
* tests/net-sockaddr.c: Likewise.
* tests/netlink_audit.c: Likewise.
* tests/pidfd_open.c: Likewise.
* tests/pidfd_send_signal.c: Likewise.
* tests/prlimit64.c: Likewise.
* tests/process_vm_readv_writev.c: Likewise.
* tests/rt_sigqueueinfo.c: Likewise.
* tests/rt_tgsigqueueinfo.c: Likewise.
* tests/sched_xetaffinity.c: Likewise.
* tests/sched_xetattr.c: Likewise.
* tests/sched_xetparam.c: Likewise.
* tests/sched_xetscheduler.c: Likewise.
* tests/signal_receive.c: Likewise.
* tests/so_peercred.c: Likewise.
* tests/xet_robust_list.c: Likewise.
* tests/xetpgid.c: Likewise.
* tests/xetpriority.c: Likewise.
---
 tests/.gitignore                              | 31 +++++++
 tests/Makefile.am                             | 36 ++++++++
 tests/fcntl--pidns-translation.c              |  2 +
 tests/fcntl-common.c                          | 82 ++++++++++++++-----
 tests/fcntl.c                                 |  1 +
 tests/fcntl64--pidns-translation.c            |  2 +
 tests/fcntl64.c                               |  3 +
 tests/fork--pidns-translation.awk             | 15 ++++
 tests/fork--pidns-translation.c               | 69 ++++++++++++++++
 tests/fork--pidns-translation.test            | 16 ++++
 tests/gen_tests.in                            | 29 ++++++-
 tests/getpgrp--pidns-translation.c            |  2 +
 tests/getpgrp.c                               |  8 +-
 tests/getpid--pidns-translation.c             |  2 +
 tests/getpid.c                                |  8 +-
 tests/getsid--pidns-translation.c             |  2 +
 tests/getsid.c                                |  9 +-
 tests/gettid--pidns-translation.c             |  2 +
 tests/gettid--pidns-translation.test          | 19 +++++
 tests/gettid.c                                |  8 +-
 tests/ioctl_block--pidns-translation.c        |  2 +
 tests/ioctl_block--pidns-translation.test     | 24 ++++++
 tests/ioctl_block.c                           | 24 +++++-
 tests/ioprio--pidns-translation.c             |  2 +
 tests/ioprio.c                                | 54 ++++++++----
 tests/kcmp-y--pidns-translation.c             |  2 +
 tests/kcmp.c                                  | 11 ++-
 tests/kill--pidns-translation.c               |  2 +
 tests/kill.c                                  | 12 ++-
 tests/migrate_pages--pidns-translation.c      |  2 +
 tests/migrate_pages.c                         | 17 +++-
 tests/move_pages--pidns-translation.c         |  2 +
 tests/move_pages.c                            | 51 +++++++-----
 tests/net-sockaddr--pidns-translation.c       |  2 +
 tests/net-sockaddr.c                          | 66 +++++++++++++--
 tests/netlink_audit--pidns-translation.c      |  2 +
 tests/netlink_audit--pidns-translation.test   | 13 +++
 tests/netlink_audit.c                         | 11 ++-
 tests/pidfd_open--pidns-translation.c         |  2 +
 tests/pidfd_open.c                            | 21 +++--
 tests/pidfd_send_signal--pidns-translation.c  |  2 +
 tests/pidfd_send_signal.c                     | 13 ++-
 tests/prlimit64--pidns-translation.c          |  2 +
 tests/prlimit64.c                             | 17 +++-
 tests/process_vm_readv--pidns-translation.c   |  2 +
 tests/process_vm_readv_writev.c               | 27 +++---
 tests/process_vm_writev--pidns-translation.c  |  2 +
 tests/rt_sigqueueinfo--pidns-translation.c    |  2 +
 tests/rt_sigqueueinfo.c                       | 15 +++-
 tests/rt_tgsigqueueinfo--pidns-translation.c  |  2 +
 tests/rt_tgsigqueueinfo.c                     | 26 ++++--
 tests/sched_xetaffinity--pidns-translation.c  |  2 +
 tests/sched_xetaffinity.c                     | 31 ++++---
 tests/sched_xetattr--pidns-translation.c      |  2 +
 tests/sched_xetattr.c                         | 47 ++++++++++-
 tests/sched_xetparam--pidns-translation.c     |  2 +
 tests/sched_xetparam.c                        | 20 +++--
 tests/sched_xetscheduler--pidns-translation.c |  2 +
 tests/sched_xetscheduler.c                    | 44 ++++++----
 tests/signal_receive--pidns-translation.c     |  2 +
 tests/signal_receive.c                        | 22 +++--
 tests/so_peercred--pidns-translation.c        |  2 +
 tests/so_peercred.c                           | 22 +++++
 tests/xet_robust_list--pidns-translation.c    |  2 +
 tests/xet_robust_list.c                       | 18 +++-
 tests/xetpgid--pidns-translation.c            |  2 +
 tests/xetpgid.c                               | 21 +++--
 tests/xetpriority--pidns-translation.c        |  2 +
 tests/xetpriority.c                           | 20 ++++-
 69 files changed, 873 insertions(+), 168 deletions(-)
 create mode 100644 tests/fcntl--pidns-translation.c
 create mode 100644 tests/fcntl64--pidns-translation.c
 create mode 100644 tests/fork--pidns-translation.awk
 create mode 100644 tests/fork--pidns-translation.c
 create mode 100755 tests/fork--pidns-translation.test
 create mode 100644 tests/getpgrp--pidns-translation.c
 create mode 100644 tests/getpid--pidns-translation.c
 create mode 100644 tests/getsid--pidns-translation.c
 create mode 100644 tests/gettid--pidns-translation.c
 create mode 100755 tests/gettid--pidns-translation.test
 create mode 100644 tests/ioctl_block--pidns-translation.c
 create mode 100755 tests/ioctl_block--pidns-translation.test
 create mode 100644 tests/ioprio--pidns-translation.c
 create mode 100644 tests/kcmp-y--pidns-translation.c
 create mode 100644 tests/kill--pidns-translation.c
 create mode 100644 tests/migrate_pages--pidns-translation.c
 create mode 100644 tests/move_pages--pidns-translation.c
 create mode 100644 tests/net-sockaddr--pidns-translation.c
 create mode 100644 tests/netlink_audit--pidns-translation.c
 create mode 100755 tests/netlink_audit--pidns-translation.test
 create mode 100644 tests/pidfd_open--pidns-translation.c
 create mode 100644 tests/pidfd_send_signal--pidns-translation.c
 create mode 100644 tests/prlimit64--pidns-translation.c
 create mode 100644 tests/process_vm_readv--pidns-translation.c
 create mode 100644 tests/process_vm_writev--pidns-translation.c
 create mode 100644 tests/rt_sigqueueinfo--pidns-translation.c
 create mode 100644 tests/rt_tgsigqueueinfo--pidns-translation.c
 create mode 100644 tests/sched_xetaffinity--pidns-translation.c
 create mode 100644 tests/sched_xetattr--pidns-translation.c
 create mode 100644 tests/sched_xetparam--pidns-translation.c
 create mode 100644 tests/sched_xetscheduler--pidns-translation.c
 create mode 100644 tests/signal_receive--pidns-translation.c
 create mode 100644 tests/so_peercred--pidns-translation.c
 create mode 100644 tests/xet_robust_list--pidns-translation.c
 create mode 100644 tests/xetpgid--pidns-translation.c
 create mode 100644 tests/xetpriority--pidns-translation.c

diff --git a/tests/.gitignore b/tests/.gitignore
index 0031d04d..4d1153fc 100644
--- a/tests/.gitignore
+++ b/tests/.gitignore
@@ -116,7 +116,9 @@ fchown
 fchown32
 fchownat
 fcntl
+fcntl--pidns-translation
 fcntl64
+fcntl64--pidns-translation
 fdatasync
 fflush
 file_handle
@@ -126,6 +128,7 @@ filter-unavailable
 finit_module
 flock
 fork-f
+fork--pidns-translation
 fsconfig
 fsconfig-P
 fsmount
@@ -168,7 +171,9 @@ getgroups
 getgroups32
 getpeername
 getpgrp
+getpgrp--pidns-translation
 getpid
+getpid--pidns-translation
 getppid
 getrandom
 getresgid
@@ -178,8 +183,10 @@ getresuid32
 getrlimit
 getrusage
 getsid
+getsid--pidns-translation
 getsockname
 gettid
+gettid--pidns-translation
 getuid
 getuid32
 getxgid
@@ -200,6 +207,7 @@ io_uring_register
 io_uring_setup
 ioctl
 ioctl_block
+ioctl_block--pidns-translation
 ioctl_dm
 ioctl_dm-v
 ioctl_evdev
@@ -275,6 +283,7 @@ ioctl_watchdog
 ioperm
 iopl
 ioprio
+ioprio--pidns-translation
 ioprio-Xabbrev
 ioprio-Xraw
 ioprio-Xverbose
@@ -299,6 +308,7 @@ ipc_shm-Xverbose
 is_linux_mips_n64
 kcmp
 kcmp-y
+kcmp-y--pidns-translation
 kern_features
 kernel_version
 kernel_version-Xabbrev
@@ -311,6 +321,7 @@ keyctl-Xabbrev
 keyctl-Xraw
 keyctl-Xverbose
 kill
+kill--pidns-translation
 kill_child
 ksysent
 ksysent.h
@@ -340,6 +351,7 @@ memfd_create-Xabbrev
 memfd_create-Xraw
 memfd_create-Xverbose
 migrate_pages
+migrate_pages--pidns-translation
 mincore
 mkdir
 mkdirat
@@ -371,6 +383,7 @@ move_pages
 move_pages-Xabbrev
 move_pages-Xraw
 move_pages-Xverbose
+move_pages--pidns-translation
 mq
 mq_sendrecv
 mq_sendrecv-read
@@ -391,6 +404,7 @@ net-packet_mreq-Xabbrev
 net-packet_mreq-Xraw
 net-packet_mreq-Xverbose
 net-sockaddr
+net-sockaddr--pidns-translation
 net-tpacket_req
 net-tpacket_stats
 net-tpacket_stats-success
@@ -400,6 +414,7 @@ net-yy-inet6
 net-yy-netlink
 net-yy-unix
 netlink_audit
+netlink_audit--pidns-translation
 netlink_crypto
 netlink_generic
 netlink_inet_diag
@@ -507,7 +522,9 @@ pidfd_open--decode-fd-socket
 pidfd_open-P
 pidfd_open-y
 pidfd_open-yy
+pidfd_open--pidns-translation
 pidfd_send_signal
+pidfd_send_signal--pidns-translation
 pipe
 pipe2
 pkey_alloc
@@ -546,8 +563,11 @@ printstrn-umoven
 printstrn-umoven-peekdata
 printstrn-umoven-undumpable
 prlimit64
+prlimit64--pidns-translation
 process_vm_readv
+process_vm_readv--pidns-translation
 process_vm_writev
+process_vm_writev--pidns-translation
 pselect6
 ptrace
 ptrace_syscall_info
@@ -597,10 +617,12 @@ rt_sigaction
 rt_sigpending
 rt_sigprocmask
 rt_sigqueueinfo
+rt_sigqueueinfo--pidns-translation
 rt_sigreturn
 rt_sigsuspend
 rt_sigtimedwait
 rt_tgsigqueueinfo
+rt_tgsigqueueinfo--pidns-translation
 run_expect_termsig
 s390_guarded_storage
 s390_guarded_storage-v
@@ -611,9 +633,13 @@ s390_sthyi-v
 sched_get_priority_mxx
 sched_rr_get_interval
 sched_xetaffinity
+sched_xetaffinity--pidns-translation
 sched_xetattr
+sched_xetattr--pidns-translation
 sched_xetparam
+sched_xetparam--pidns-translation
 sched_xetscheduler
+sched_xetscheduler--pidns-translation
 sched_yield
 scm_rights
 scno.h
@@ -669,6 +695,7 @@ sigaltstack
 siginfo
 signal
 signal_receive
+signal_receive--pidns-translation
 signalfd4
 sigpending
 sigprocmask
@@ -681,6 +708,7 @@ so_peercred
 so_peercred-Xabbrev
 so_peercred-Xraw
 so_peercred-Xverbose
+so_peercred--pidns-translation
 sock_filter-v
 sock_filter-v-Xabbrev
 sock_filter-v-Xraw
@@ -783,9 +811,12 @@ waitpid
 xattr
 xattr-strings
 xet_robust_list
+xet_robust_list--pidns-translation
 xet_thread_area_x86
 xetitimer
 xetpgid
+xetpgid--pidns-translation
 xetpriority
+xetpriority--pidns-translation
 xettimeofday
 zeroargc
diff --git a/tests/Makefile.am b/tests/Makefile.am
index 7a583a3a..f2c5da83 100644
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@@ -109,17 +109,25 @@ check_PROGRAMS = $(PURE_EXECUTABLES) \
 	delay \
 	execve-v \
 	execveat-v \
+	fcntl--pidns-translation \
+	fcntl64--pidns-translation \
 	filter_seccomp-flag \
 	filter_seccomp-perf \
 	filter-unavailable \
 	fork-f \
+	fork--pidns-translation \
 	fsync-y \
 	get_process_reaper \
+	getpgrp--pidns-translation	\
 	getpid	\
+	getpid--pidns-translation	\
 	getppid	\
+	getsid--pidns-translation \
 	gettid \
+	gettid--pidns-translation \
 	inject-nf \
 	int_0x80 \
+	ioctl_block--pidns-translation \
 	ioctl_dm-v \
 	ioctl_evdev-success \
 	ioctl_evdev-success-Xabbrev \
@@ -150,18 +158,25 @@ check_PROGRAMS = $(PURE_EXECUTABLES) \
 	ioctl_v4l2-success-v-Xabbrev \
 	ioctl_v4l2-success-v-Xraw \
 	ioctl_v4l2-success-v-Xverbose \
+	ioprio--pidns-translation \
 	is_linux_mips_n64 \
+	kcmp-y--pidns-translation \
 	kill_child \
+	kill--pidns-translation \
 	ksysent \
 	list_sigaction_signum \
 	localtime \
 	looping_threads \
+	migrate_pages--pidns-translation \
 	mmsg-silent \
 	mmsg_name-v \
+	move_pages--pidns-translation \
 	msg_control-v \
 	net-accept-connect \
+	net-sockaddr--pidns-translation \
 	net-tpacket_stats-success \
 	nlattr_ifla_xdp-y \
+	netlink_audit--pidns-translation \
 	netlink_inet_diag \
 	netlink_netlink_diag \
 	netlink_unix_diag \
@@ -173,14 +188,19 @@ check_PROGRAMS = $(PURE_EXECUTABLES) \
 	pc \
 	perf_event_open_nonverbose \
 	perf_event_open_unabbrev \
+	pidfd_open--pidns-translation \
+	pidfd_send_signal--pidns-translation \
 	poll-P \
 	ppoll-P \
 	ppoll-v \
+	prlimit64--pidns-translation \
 	prctl-seccomp-filter-v \
 	prctl-seccomp-strict \
 	prctl-spec-inject \
 	print_maxfd \
 	print_ppid_tracerpid \
+	process_vm_readv--pidns-translation \
+	process_vm_writev--pidns-translation \
 	qual_fault \
 	qual_inject-error-signal \
 	qual_inject-retval \
@@ -194,7 +214,13 @@ check_PROGRAMS = $(PURE_EXECUTABLES) \
 	quotactl-xfs-v \
 	redirect-fds \
 	restart_syscall \
+	rt_sigqueueinfo--pidns-translation \
+	rt_tgsigqueueinfo--pidns-translation \
 	run_expect_termsig \
+	sched_xetaffinity--pidns-translation \
+	sched_xetattr--pidns-translation \
+	sched_xetparam--pidns-translation \
+	sched_xetscheduler--pidns-translation \
 	scm_rights \
 	seccomp-filter-v \
 	seccomp-strict \
@@ -204,12 +230,14 @@ check_PROGRAMS = $(PURE_EXECUTABLES) \
 	set_sigign \
 	setpgrp-exec \
 	signal_receive \
+	signal_receive--pidns-translation \
 	sleep \
 	stack-fcall \
 	stack-fcall-attach \
 	stack-fcall-mangled \
 	status-none-threads \
 	status-unfinished-threads \
+	so_peercred--pidns-translation \
 	syslog-success \
 	threads-execve \
 	threads-execve--quiet-thread-execve \
@@ -223,6 +251,9 @@ check_PROGRAMS = $(PURE_EXECUTABLES) \
 	vfork-f \
 	wait4-v \
 	waitid-v \
+	xetpgid--pidns-translation \
+	xetpriority--pidns-translation \
+	xet_robust_list--pidns-translation \
 	zeroargc \
 	# end of check_PROGRAMS
 
@@ -310,6 +341,7 @@ DECODER_TESTS = \
 	int_0x80.test \
 	inotify_init-y.test \
 	ioctl.test \
+	ioctl_block--pidns-translation.test \
 	ioctl_evdev-success.test \
 	ipc_msgbuf.test \
 	kern_features-fault.test \
@@ -381,12 +413,15 @@ MISC_TESTS = \
 	filtering_fd-syntax.test \
 	filtering_syscall-syntax.test \
 	first_exec_failure.test \
+	fork--pidns-translation.test \
 	get_regs.test \
+	gettid--pidns-translation.test \
 	inject-nf.test \
 	interactive_block.test \
 	kill_child.test \
 	localtime.test \
 	looping_threads.test \
+	netlink_audit--pidns-translation.test \
 	opipe.test \
 	options-syntax.test \
 	pc.test \
@@ -467,6 +502,7 @@ EXTRA_DIST = \
 	filter_seccomp.in \
 	filter_seccomp.sh \
 	filter-unavailable.expected \
+	fork--pidns-translation.awk \
 	fstatat.c \
 	fstatx.c \
 	gen_pure_executables.sh \
diff --git a/tests/fcntl--pidns-translation.c b/tests/fcntl--pidns-translation.c
new file mode 100644
index 00000000..e249424a
--- /dev/null
+++ b/tests/fcntl--pidns-translation.c
@@ -0,0 +1,2 @@
+#define PIDNS_TRANSLATION
+#include "fcntl.c"
diff --git a/tests/fcntl-common.c b/tests/fcntl-common.c
index 27694326..d9e29939 100644
--- a/tests/fcntl-common.c
+++ b/tests/fcntl-common.c
@@ -13,6 +13,8 @@
 #include <unistd.h>
 #include <assert.h>
 #include "flock.h"
+#include "pidns.h"
+#include "scno.h"
 
 #define FILE_LEN 4096
 
@@ -48,12 +50,14 @@ test_flock_einval(const int cmd, const char *name)
 	fl->l_len = (TYPEOF_FLOCK_OFF_T) 0xdefaced2cafef00dULL;
 
 	invoke_test_syscall(0, cmd, fl);
+	pidns_print_leader();
 	printf("%s(0, %s, {l_type=F_RDLCK, l_whence=SEEK_SET"
 	       ", l_start=%jd, l_len=%jd}) = %s\n", TEST_SYSCALL_STR, name,
 	       (intmax_t) fl->l_start, (intmax_t) fl->l_len, errstr);
 
 	void *const bad_addr = (void *) fl + 1;
 	invoke_test_syscall(0, cmd, bad_addr);
+	pidns_print_leader();
 	printf("%s(0, %s, %p) = %s\n",
 	       TEST_SYSCALL_STR, name, bad_addr, errstr);
 }
@@ -72,12 +76,14 @@ test_flock64_einval(const int cmd, const char *name)
 	fl->l_len = (TYPEOF_FLOCK_OFF_T) 0xdefaced2cafef00dULL;
 
 	invoke_test_syscall(0, cmd, fl);
+	pidns_print_leader();
 	printf("%s(0, %s, {l_type=F_RDLCK, l_whence=SEEK_SET"
 	       ", l_start=%jd, l_len=%jd}) = %s\n", TEST_SYSCALL_STR, name,
 	       (intmax_t) fl->l_start, (intmax_t) fl->l_len, errstr);
 
 	void *const bad_addr = (void *) fl + 1;
 	invoke_test_syscall(0, cmd, bad_addr);
+	pidns_print_leader();
 	printf("%s(0, %s, %p) = %s\n",
 	       TEST_SYSCALL_STR, name, bad_addr, errstr);
 }
@@ -94,6 +100,7 @@ test_flock(void)
 	fl->l_len = FILE_LEN;
 
 	long rc = invoke_test_syscall(0, F_SETLK, fl);
+	pidns_print_leader();
 	printf("%s(0, F_SETLK, {l_type=F_RDLCK, l_whence=SEEK_SET"
 	       ", l_start=0, l_len=%d}) = %s\n",
 	       TEST_SYSCALL_STR, FILE_LEN, errstr);
@@ -101,11 +108,13 @@ test_flock(void)
 		return;
 
 	invoke_test_syscall(0, F_GETLK, fl);
+	pidns_print_leader();
 	printf("%s(0, F_GETLK, {l_type=F_UNLCK, l_whence=SEEK_SET"
 	       ", l_start=0, l_len=%d, l_pid=0}) = 0\n",
 	       TEST_SYSCALL_STR, FILE_LEN);
 
 	invoke_test_syscall(0, F_SETLKW, fl);
+	pidns_print_leader();
 	printf("%s(0, F_SETLKW, {l_type=F_UNLCK, l_whence=SEEK_SET"
 	       ", l_start=0, l_len=%d}) = 0\n",
 	       TEST_SYSCALL_STR, FILE_LEN);
@@ -124,6 +133,7 @@ test_flock64_ofd(void)
 	fl->l_len = FILE_LEN;
 
 	long rc = invoke_test_syscall(0, F_OFD_SETLK, fl);
+	pidns_print_leader();
 	printf("%s(0, F_OFD_SETLK, {l_type=F_RDLCK, l_whence=SEEK_SET"
 	       ", l_start=0, l_len=%d}) = %s\n",
 	       TEST_SYSCALL_STR, FILE_LEN, errstr);
@@ -131,11 +141,13 @@ test_flock64_ofd(void)
 		return;
 
 	invoke_test_syscall(0, F_OFD_GETLK, fl);
+	pidns_print_leader();
 	printf("%s(0, F_OFD_GETLK, {l_type=F_UNLCK, l_whence=SEEK_SET"
 	       ", l_start=0, l_len=%d, l_pid=0}) = 0\n",
 	       TEST_SYSCALL_STR, FILE_LEN);
 
 	invoke_test_syscall(0, F_OFD_SETLKW, fl);
+	pidns_print_leader();
 	printf("%s(0, F_OFD_SETLKW, {l_type=F_UNLCK, l_whence=SEEK_SET"
 	       ", l_start=0, l_len=%d}) = 0\n",
 	       TEST_SYSCALL_STR, FILE_LEN);
@@ -167,18 +179,21 @@ test_flock64(void)
 static long
 test_f_owner_ex_type_pid(const int cmd, const char *const cmd_name,
 			 const int type, const char *const type_name,
-			 pid_t pid)
+			 enum pid_type pid_type, pid_t pid)
 {
 	TAIL_ALLOC_OBJECT_CONST_PTR(struct_kernel_f_owner_ex, fo);
 
 	fo->type = type;
 	fo->pid = pid;
 	long rc = invoke_test_syscall(0, cmd, fo);
-	printf("%s(0, %s, {type=%s, pid=%d}) = %s\n",
-	       TEST_SYSCALL_STR, cmd_name, type_name, fo->pid, errstr);
+	pidns_print_leader();
+	printf("%s(0, %s, {type=%s, pid=%d%s}) = %s\n",
+	       TEST_SYSCALL_STR, cmd_name, type_name,
+	       fo->pid, pidns_pid2str(pid_type), errstr);
 
 	void *bad_addr = (void *) fo + 1;
 	invoke_test_syscall(0, cmd, bad_addr);
+	pidns_print_leader();
 	printf("%s(0, %s, %p) = %s\n",
 	       TEST_SYSCALL_STR, cmd_name, bad_addr, errstr);
 
@@ -187,35 +202,39 @@ test_f_owner_ex_type_pid(const int cmd, const char *const cmd_name,
 
 static void
 test_f_owner_ex_umove_or_printaddr(const int type, const char *const type_name,
-				   pid_t pid)
+				   enum pid_type pid_type, pid_t pid)
 {
 	long rc = test_f_owner_ex_type_pid(ARG_STR(F_SETOWN_EX),
-					   type, type_name, pid);
+					   type, type_name, pid_type, pid);
 	if (!rc)
 		test_f_owner_ex_type_pid(ARG_STR(F_GETOWN_EX),
-					 type, type_name, pid);
+					 type, type_name, pid_type, pid);
 }
 
 static void
 test_f_owner_ex(void)
 {
-	static const struct {
+	struct {
 		int type;
 		const char *type_name;
-		pid_t pid[2];
+		enum pid_type pid_type;
+		pid_t pid;
 	} a[] = {
-		{ ARG_STR(F_OWNER_TID), { 1234567890, 20 } },
-		{ ARG_STR(F_OWNER_PID), { 1298126790, 30 } },
-		{ ARG_STR(F_OWNER_PGRP), { 1294567890, 40 } }
+		{ ARG_STR(F_OWNER_TID), PT_NONE, 1234567890 },
+		{ ARG_STR(F_OWNER_PID), PT_NONE, 1234567890 },
+		{ ARG_STR(F_OWNER_PGRP), PT_NONE, 1234567890 },
+		{ ARG_STR(F_OWNER_TID), PT_TID, 0 },
+		{ ARG_STR(F_OWNER_PID), PT_TGID, 0 },
+		{ ARG_STR(F_OWNER_PGRP), PT_PGID, 0 },
 	};
 
-	for (unsigned int i = 0; i < ARRAY_SIZE(a); i++) {
-		for (unsigned int j = 0; j < ARRAY_SIZE(a[0].pid); j++) {
-			test_f_owner_ex_umove_or_printaddr(a[i].type,
-							   a[i].type_name,
-							   a[i].pid[j]);
-		}
-	}
+	a[3].pid = syscall(__NR_gettid);
+	a[4].pid = getpid();
+	a[5].pid = getpgid(0);
+
+	for (unsigned int i = 0; i < ARRAY_SIZE(a); i++)
+		test_f_owner_ex_umove_or_printaddr(a[i].type, a[i].type_name,
+			a[i].pid_type, a[i].pid);
 }
 #endif /* TEST_F_OWNER_EX */
 
@@ -228,6 +247,23 @@ struct fcntl_cmd_check {
 	void (*print_flags)(long rc);
 };
 
+static void
+test_xetown(void)
+{
+	const int pid = getpid();
+	const char *pid_str = pidns_pid2str(PT_TGID);
+
+	invoke_test_syscall(0, F_SETOWN, (void *) (intptr_t) pid);
+	pidns_print_leader();
+	printf("%s(0, F_SETOWN, %d%s) = %s\n",
+		TEST_SYSCALL_STR, pid, pid_str, errstr);
+
+	invoke_test_syscall(0, F_GETOWN, NULL);
+	pidns_print_leader();
+	printf("%s(0, F_GETOWN) = %d%s\n",
+		TEST_SYSCALL_STR, pid, pid_str);
+}
+
 static void
 print_retval_flags(const struct fcntl_cmd_check *check, long rc)
 {
@@ -243,12 +279,14 @@ static void
 test_other_set_cmd(const struct fcntl_cmd_check *check)
 {
 	invoke_test_syscall(check->fd, check->cmd, (void *) check->arg);
+	pidns_print_leader();
 	printf("%s(%d, %s, %s) = %s\n",
 	       TEST_SYSCALL_STR, check->fd,
 	       check->cmd_str, check->arg_str, errstr);
 
 	/* bad file fd */
 	invoke_test_syscall(-1, check->cmd, (void *) check->arg);
+	pidns_print_leader();
 	printf("%s(-1, %s, %s) = %s\n",
 	       TEST_SYSCALL_STR, check->cmd_str,
 	       check->arg_str, errstr);
@@ -258,12 +296,14 @@ static void
 test_other_get_cmd(const struct fcntl_cmd_check *check)
 {
 	long rc = invoke_test_syscall(check->fd, check->cmd, NULL);
+	pidns_print_leader();
 	printf("%s(%d, %s) = ",
 	       TEST_SYSCALL_STR, check->fd, check->cmd_str);
 	print_retval_flags(check, rc);
 
 	/* bad file fd */
 	invoke_test_syscall(-1, check->cmd, NULL);
+	pidns_print_leader();
 	printf("%s(-1, %s) = %s\n",
 	       TEST_SYSCALL_STR, check->cmd_str, errstr);
 }
@@ -315,7 +355,6 @@ test_fcntl_others(void)
 {
 	static const struct fcntl_cmd_check set_checks[] = {
 		{ 0, ARG_STR(F_SETFD), ARG_STR(FD_CLOEXEC) },
-		{ 0, ARG_STR(F_SETOWN), ARG_STR(20) },
 #ifdef F_SETPIPE_SZ
 		{ 0, ARG_STR(F_SETPIPE_SZ), ARG_STR(4097) },
 #endif
@@ -336,7 +375,6 @@ test_fcntl_others(void)
 	static const struct fcntl_cmd_check get_checks[] = {
 		{ 0, ARG_STR(F_GETFD), .print_flags = print_flags_getfd },
 		{ 1, ARG_STR(F_GETFD), .print_flags = print_flags_getfd },
-		{ 0, ARG_STR(F_GETOWN) },
 #ifdef F_GETPIPE_SZ
 		{ 0, ARG_STR(F_GETPIPE_SZ) },
 #endif
@@ -360,6 +398,8 @@ create_sample(void)
 int
 main(void)
 {
+	PIDNS_TEST_INIT;
+
 	create_sample();
 	test_flock();
 	test_flock64();
@@ -367,7 +407,9 @@ main(void)
 	test_f_owner_ex();
 #endif
 	test_fcntl_others();
+	test_xetown();
 
+	pidns_print_leader();
 	puts("+++ exited with 0 +++");
 	return 0;
 }
diff --git a/tests/fcntl.c b/tests/fcntl.c
index f38b8afb..673c06e4 100644
--- a/tests/fcntl.c
+++ b/tests/fcntl.c
@@ -24,6 +24,7 @@ test_flock64_undecoded(const int cmd, const char *name)
 		.l_len = 0xdefaced2cafef00dULL
 	};
 	invoke_test_syscall(0, cmd, &fl);
+	pidns_print_leader();
 	printf("%s(0, %s, %p) = %s\n",
 	       TEST_SYSCALL_STR, name, &fl, errstr);
 }
diff --git a/tests/fcntl64--pidns-translation.c b/tests/fcntl64--pidns-translation.c
new file mode 100644
index 00000000..c6fdadd1
--- /dev/null
+++ b/tests/fcntl64--pidns-translation.c
@@ -0,0 +1,2 @@
+#define PIDNS_TRANSLATION
+#include "fcntl64.c"
diff --git a/tests/fcntl64.c b/tests/fcntl64.c
index 78e53b0d..f7b3f2fb 100644
--- a/tests/fcntl64.c
+++ b/tests/fcntl64.c
@@ -27,6 +27,7 @@ test_flock64_lk64(void)
 	fl->l_len = FILE_LEN;
 
 	long rc = invoke_test_syscall(0, F_SETLK64, fl);
+	pidns_print_leader();
 	printf("%s(0, F_SETLK64, {l_type=F_RDLCK, l_whence=SEEK_SET"
 	       ", l_start=0, l_len=%d}) = %s\n",
 	       TEST_SYSCALL_STR, FILE_LEN, errstr);
@@ -35,11 +36,13 @@ test_flock64_lk64(void)
 		return;
 
 	invoke_test_syscall(0, F_GETLK64, fl);
+	pidns_print_leader();
 	printf("%s(0, F_GETLK64, {l_type=F_UNLCK, l_whence=SEEK_SET"
 	       ", l_start=0, l_len=%d, l_pid=0}) = 0\n",
 	       TEST_SYSCALL_STR, FILE_LEN);
 
 	invoke_test_syscall(0, F_SETLKW64, fl);
+	pidns_print_leader();
 	printf("%s(0, F_SETLKW64, {l_type=F_UNLCK, l_whence=SEEK_SET"
 	       ", l_start=0, l_len=%d}) = 0\n",
 	       TEST_SYSCALL_STR, FILE_LEN);
diff --git a/tests/fork--pidns-translation.awk b/tests/fork--pidns-translation.awk
new file mode 100644
index 00000000..ef6858f4
--- /dev/null
+++ b/tests/fork--pidns-translation.awk
@@ -0,0 +1,15 @@
+/fork/ {
+        match($0, "([0-9]+) in strace\x27s PID NS", a);
+        if (a[1])
+                fork_pid = a[1]
+}
+
+/exited with 0/ {
+        if (!exit_pid)
+                exit_pid = $1
+}
+
+END {
+        if (!fork_pid || !exit_pid || fork_pid != exit_pid)
+                exit 1
+}
diff --git a/tests/fork--pidns-translation.c b/tests/fork--pidns-translation.c
new file mode 100644
index 00000000..73c39d5d
--- /dev/null
+++ b/tests/fork--pidns-translation.c
@@ -0,0 +1,69 @@
+/*
+ * Test PID namespace translation
+ *
+ * Copyright (c) 2020 ?kos Uzonyi <uzonyi.akos at gmail.com>
+ * All rights reserved.
+ *
+ * SPDX-License-Identifier: LGPL-2.1-or-later
+ */
+
+#include "tests.h"
+#include "scno.h"
+#include "pidns.h"
+
+#ifdef __NR_fork
+
+#include <errno.h>
+#include <limits.h>
+#include <sched.h>
+#include <signal.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <sys/wait.h>
+#include <unistd.h>
+#include <linux/sched.h>
+
+static int
+fork_chain(int depth)
+{
+	if (!depth)
+		return 0;
+
+	int pid = syscall(__NR_fork);
+	if (pid < 0)
+		return errno;
+
+	if (!pid)
+		_exit(fork_chain(depth - 1));
+
+	int status;
+	if (wait(&status) < 0)
+		return errno;
+
+	if (!WIFEXITED(status))
+		return -1;
+
+	return WEXITSTATUS(status);
+}
+
+int main(void)
+{
+	check_ns_ioctl();
+
+	if (unshare(CLONE_NEWPID | CLONE_NEWUSER) < 0) {
+		if (errno == EPERM)
+			perror_msg_and_skip("unshare");
+
+		perror_msg_and_fail("unshare");
+	}
+
+	errno = fork_chain(2);
+	if (errno)
+		perror("fork_chain");
+}
+
+#else
+
+SKIP_MAIN_UNDEFINED("__NR_fork")
+
+#endif
diff --git a/tests/fork--pidns-translation.test b/tests/fork--pidns-translation.test
new file mode 100755
index 00000000..fa7ecda5
--- /dev/null
+++ b/tests/fork--pidns-translation.test
@@ -0,0 +1,16 @@
+#!/bin/sh
+#
+# Check pidns translation of fork's return value.
+#
+# Copyright (c) 2020 The strace developers.
+# All rights reserved.
+#
+# SPDX-License-Identifier: LGPL-2.1-or-later
+
+. "${srcdir=.}/init.sh"
+
+require_min_kernel_version_or_skip 4.9
+
+run_prog
+run_strace -a6 --pidns-translation -f -e trace=fork $args
+match_awk
diff --git a/tests/gen_tests.in b/tests/gen_tests.in
index 6f8e1420..10374a9e 100644
--- a/tests/gen_tests.in
+++ b/tests/gen_tests.in
@@ -93,7 +93,9 @@ fchown	-a16
 fchown32	-a18
 fchownat
 fcntl	-a8
+fcntl--pidns-translation	test_pidns -a8 -e trace=fcntl
 fcntl64	-a8
+fcntl64--pidns-translation	test_pidns -a8 -e trace=fcntl64
 fdatasync	-a14
 file_handle	-e trace=name_to_handle_at,open_by_handle_at
 file_ioctl	+ioctl.test
@@ -147,7 +149,9 @@ getgroups	-a17
 getgroups32	-a19
 getpeername	-a27
 getpgrp	-a10
+getpgrp--pidns-translation	test_pidns -e trace=getpgrp -a10
 getpid	-a9
+getpid--pidns-translation	test_pidns -e trace=getpid -a9
 getppid	-a10
 getrandom	-a32 -s3
 getresgid	-a25
@@ -157,6 +161,7 @@ getresuid32	-a27
 getrlimit	-a27
 getrusage	-v
 getsid	-a10
+getsid--pidns-translation	test_pidns -e trace=getsid -a10
 getsockname	-a27
 gettid	-a9
 getuid-creds	+getuid.test
@@ -250,6 +255,7 @@ ioctl_watchdog	+ioctl.test
 ioperm	-a27
 iopl	-a8
 ioprio	-a18 -e trace=ioprio_get,ioprio_set
+ioprio--pidns-translation	test_pidns -a18 -e trace=ioprio_get,ioprio_set
 ioprio-Xabbrev	-a18 -e trace=ioprio_get,ioprio_set -Xabbrev
 ioprio-Xraw	-a18 -e trace=ioprio_get,ioprio_set -Xraw
 ioprio-Xverbose	-a18 -e trace=ioprio_get,ioprio_set -Xverbose
@@ -272,6 +278,7 @@ ipc_shm-Xraw	+ipc.sh -Xraw -a19
 ipc_shm-Xverbose	+ipc.sh -Xverbose -a34
 kcmp	-a22
 kcmp-y	-a22 -y -e trace=kcmp
+kcmp-y--pidns-translation	test_pidns -a22 -y -e trace=kcmp
 kern_features -a16
 kernel_version	-a16 -v -e trace=bpf
 kernel_version-Xabbrev	-a16 -Xabbrev -v -e trace=bpf
@@ -284,6 +291,7 @@ keyctl-Xabbrev	-a31 -s10 -e trace=keyctl -Xabbrev
 keyctl-Xraw	-a13 -s10 -e trace=keyctl -Xraw
 keyctl-Xverbose	-a41 -s10 -e trace=keyctl -Xverbose
 kill	-a12 -esignal=none
+kill--pidns-translation	test_pidns -a12 -e trace=kill -esignal=none
 ksysent	../$NAME
 lchown	-a30
 lchown32	-a32
@@ -305,6 +313,7 @@ memfd_create-Xabbrev	-Xabbrev -e trace=memfd_create
 memfd_create-Xraw	-a30 -Xraw -e trace=memfd_create
 memfd_create-Xverbose	-Xverbose -e trace=memfd_create
 migrate_pages	-a33
+migrate_pages--pidns-translation	test_pidns -a33 -e trace=migrate_pages
 mincore	-a22
 mkdir	-a20
 mkdirat	-a28
@@ -335,6 +344,7 @@ move_pages	-s3
 move_pages-Xabbrev	-s3 -e trace=move_pages -Xabbrev
 move_pages-Xraw	-s3 -a36 -e trace=move_pages -Xraw
 move_pages-Xverbose	-s3 -e trace=move_pages -Xverbose
+move_pages--pidns-translation	test_pidns -s3 -e trace=move_pages
 mq	-a32 -e trace=mq_getsetattr,mq_open,mq_unlink
 mq_sendrecv	-a14 -e trace=mq_open,mq_notify,mq_timedsend,mq_timedreceive,mq_unlink
 mq_sendrecv-read	-eread=0 -a14 -e trace=mq_open,mq_notify,mq_timedsend,mq_timedreceive,mq_unlink
@@ -354,6 +364,7 @@ net-packet_mreq-Xabbrev	-e trace=setsockopt -Xabbrev
 net-packet_mreq-Xraw	-e trace=setsockopt -Xraw
 net-packet_mreq-Xverbose	-e trace=setsockopt -Xverbose
 net-sockaddr	-a24 -e trace=connect
+net-sockaddr--pidns-translation	test_pidns -a24 -e trace=connect
 net-tpacket_req -e trace=setsockopt
 net-tpacket_stats -e trace=getsockopt
 net-yy-inet6	+net-yy-inet.test
@@ -457,7 +468,9 @@ pidfd_open--decode-fd-socket	-a17 -e decode-fd=socket -e trace=pidfd_open
 pidfd_open-P	-a17 -P /dev/full -e trace=pidfd_open
 pidfd_open-y	-a17 -y -e trace=pidfd_open
 pidfd_open-yy	-a17 -yy -e trace=pidfd_open
+pidfd_open--pidns-translation	test_pidns -a17 -e trace=pidfd_open
 pidfd_send_signal
+pidfd_send_signal--pidns-translation test_pidns -e trace=pidfd_send_signal
 pipe2	-a15
 pkey_alloc	-a17
 pkey_free	-a13
@@ -480,8 +493,11 @@ printstrn-umoven	-s4096 -e signal=none -e trace=add_key
 printstrn-umoven-peekdata	-e signal=none -e trace=add_key
 printstrn-umoven-undumpable	-e signal=none -e trace=add_key
 prlimit64
+prlimit64--pidns-translation     test_pidns -e trace=prlimit64
 process_vm_readv	-s5 -a37
+process_vm_readv--pidns-translation	test_pidns -s5 -a37 -e trace=process_vm_readv
 process_vm_writev	-s5 -a38
+process_vm_writev--pidns-translation	test_pidns -s5 -a38 -e trace=process_vm_writev
 pselect6
 ptrace	-a23 -e signal=none
 ptrace_syscall_info	-a35 -e signal=none -e trace=ptrace
@@ -518,10 +534,12 @@ rmdir	-a22
 rt_sigpending	-a20
 rt_sigprocmask
 rt_sigqueueinfo	-esignal=none
+rt_sigqueueinfo--pidns-translation	test_pidns -esignal=none -e trace=rt_sigqueueinfo
 rt_sigreturn	-esignal='!USR1'
 rt_sigsuspend	-a20 -esignal=none
 rt_sigtimedwait	-a38
 rt_tgsigqueueinfo	-esignal=none
+rt_tgsigqueueinfo--pidns-translation	test_pidns -esignal=none -e trace=rt_tgsigqueueinfo
 s390_guarded_storage	-a32
 s390_guarded_storage-v	-e trace=s390_guarded_storage -a32 -v
 s390_pci_mmio_read_write	-e trace=s390_pci_mmio_read,s390_pci_mmio_write -a30
@@ -532,9 +550,13 @@ sched	test_trace_expr times -e/sched
 sched_get_priority_mxx	-a33 -e trace=sched_get_priority_min,sched_get_priority_max
 sched_rr_get_interval	-a31
 sched_xetaffinity	-a28 -e trace=sched_getaffinity,sched_setaffinity
+sched_xetaffinity--pidns-translation	test_pidns -a28 -e trace=sched_getaffinity,sched_setaffinity
 sched_xetattr	-a29 -e trace=sched_getattr,sched_setattr
+sched_xetattr--pidns-translation	test_pidns -a29 -e trace=sched_getattr,sched_setattr
 sched_xetparam	-a23 -e trace=sched_getparam,sched_setparam
+sched_xetparam--pidns-translation	test_pidns -a23 -e trace=sched_getparam,sched_setparam
 sched_xetscheduler	-a22 -e trace=sched_getscheduler,sched_setscheduler
+sched_xetscheduler--pidns-translation	test_pidns -a22 -e trace=sched_getscheduler,sched_setscheduler
 sched_yield	-a14
 seccomp-filter	-e trace=seccomp
 seccomp-filter-v	-v -e trace=seccomp
@@ -581,6 +603,7 @@ sigaction	-a31
 siginfo	-e trace=none
 signal	-a25 -e signal=none -e trace='/^signal$'
 signal_receive	-a16 -e trace=kill
+signal_receive--pidns-translation	test_pidns -a16 -e trace=kill
 signalfd4
 sigpending	-a15
 sigprocmask	-a34
@@ -592,6 +615,7 @@ so_peercred	-e trace=getsockopt
 so_peercred-Xabbrev	-e trace=getsockopt -Xabbrev
 so_peercred-Xraw	-e trace=getsockopt -Xraw -a39
 so_peercred-Xverbose	-e trace=getsockopt -Xverbose
+so_peercred--pidns-translation	test_pidns -e trace=getsockopt
 sock_filter-v	-v -e trace=getsockopt,setsockopt
 sock_filter-v-Xabbrev	-v -e trace=getsockopt,setsockopt -X abbrev
 sock_filter-v-Xraw	-a 37 -v -e trace=getsockopt,setsockopt -X raw
@@ -721,7 +745,10 @@ waitpid	-a28
 xattr	-a22 -e trace=getxattr,fgetxattr,lgetxattr,setxattr,fsetxattr,lsetxattr,listxattr,flistxattr,llistxattr,removexattr,fremovexattr,lremovexattr
 xattr-strings	-a22 -s 4 -e trace=fsetxattr
 xet_robust_list	-a24 -e trace=get_robust_list,set_robust_list
+xet_robust_list--pidns-translation	test_pidns -a24 -e trace=get_robust_list,set_robust_list
 xetitimer	-a29 -e trace=setitimer,getitimer
 xetpgid	-a11 -e trace=getpgid,setpgid
-xetpriority	-a29 -e trace=getpriority,setpriority
+xetpgid--pidns-translation	test_pidns -a11 -e trace=getpgid,setpgid
+xetpriority	-a27 -e trace=getpriority,setpriority
+xetpriority--pidns-translation	test_pidns -a27 -e trace=getpriority,setpriority
 xettimeofday	-a20 -e trace=gettimeofday,settimeofday
diff --git a/tests/getpgrp--pidns-translation.c b/tests/getpgrp--pidns-translation.c
new file mode 100644
index 00000000..de8ceb33
--- /dev/null
+++ b/tests/getpgrp--pidns-translation.c
@@ -0,0 +1,2 @@
+#define PIDNS_TRANSLATION
+#include "getpgrp.c"
diff --git a/tests/getpgrp.c b/tests/getpgrp.c
index 104f4811..3f0b9dd1 100644
--- a/tests/getpgrp.c
+++ b/tests/getpgrp.c
@@ -7,6 +7,7 @@
 
 #include "tests.h"
 #include "scno.h"
+#include "pidns.h"
 
 #ifdef __NR_getpgrp
 
@@ -16,8 +17,13 @@
 int
 main(void)
 {
-	printf("getpgrp() = %ld\n", syscall(__NR_getpgrp));
+	PIDNS_TEST_INIT;
 
+	pidns_print_leader();
+	printf("getpgrp() = %d%s\n", (int) syscall(__NR_getpgrp),
+		pidns_pid2str(PT_PGID));
+
+	pidns_print_leader();
 	puts("+++ exited with 0 +++");
 	return 0;
 }
diff --git a/tests/getpid--pidns-translation.c b/tests/getpid--pidns-translation.c
new file mode 100644
index 00000000..94b12a1a
--- /dev/null
+++ b/tests/getpid--pidns-translation.c
@@ -0,0 +1,2 @@
+#define PIDNS_TRANSLATION
+#include "getpid.c"
diff --git a/tests/getpid.c b/tests/getpid.c
index 988f19d5..7ec4e6e8 100644
--- a/tests/getpid.c
+++ b/tests/getpid.c
@@ -7,6 +7,7 @@
 
 #include "tests.h"
 #include "scno.h"
+#include "pidns.h"
 
 #if defined __NR_getpid && (!defined __NR_getxpid || __NR_getxpid != __NR_getpid)
 
@@ -16,7 +17,12 @@
 int
 main(void)
 {
-	printf("getpid() = %ld\n", syscall(__NR_getpid));
+	PIDNS_TEST_INIT;
+
+	pidns_print_leader();
+	printf("getpid() = %d%s\n", (int) syscall(__NR_getpid),
+		pidns_pid2str(PT_TGID));
+	pidns_print_leader();
 	puts("+++ exited with 0 +++");
 	return 0;
 }
diff --git a/tests/getsid--pidns-translation.c b/tests/getsid--pidns-translation.c
new file mode 100644
index 00000000..7f983e87
--- /dev/null
+++ b/tests/getsid--pidns-translation.c
@@ -0,0 +1,2 @@
+#define PIDNS_TRANSLATION
+#include "getsid.c"
diff --git a/tests/getsid.c b/tests/getsid.c
index 588ea4ab..3bf74734 100644
--- a/tests/getsid.c
+++ b/tests/getsid.c
@@ -6,15 +6,22 @@
  */
 
 #include "tests.h"
+#include "pidns.h"
+
 #include <stdio.h>
 #include <unistd.h>
 
 int
 main(void)
 {
+	PIDNS_TEST_INIT;
+
 	pid_t pid = getpid();
-	printf("getsid(%d) = %d\n", pid, getsid(pid));
+	pidns_print_leader();
+	printf("getsid(%d%s) = %d%s\n", pid, pidns_pid2str(PT_TGID),
+		getsid(pid), pidns_pid2str(PT_SID));
 
+	pidns_print_leader();
 	puts("+++ exited with 0 +++");
 	return 0;
 }
diff --git a/tests/gettid--pidns-translation.c b/tests/gettid--pidns-translation.c
new file mode 100644
index 00000000..500c3213
--- /dev/null
+++ b/tests/gettid--pidns-translation.c
@@ -0,0 +1,2 @@
+#define PIDNS_TRANSLATION
+#include "gettid.c"
diff --git a/tests/gettid--pidns-translation.test b/tests/gettid--pidns-translation.test
new file mode 100755
index 00000000..b9773e04
--- /dev/null
+++ b/tests/gettid--pidns-translation.test
@@ -0,0 +1,19 @@
+#!/bin/sh
+#
+# Check pidns translation of gettid's return value.
+#
+# Copyright (c) 2020 The strace developers.
+# All rights reserved.
+#
+# SPDX-License-Identifier: LGPL-2.1-or-later
+
+. "${srcdir=.}/init.sh"
+
+require_min_kernel_version_or_skip 4.9
+
+run_prog > /dev/null
+run_strace -a9 --pidns-translation -f -e trace=gettid $args > "$EXP"
+parent_pid="$(tail -n 2 $LOG | head -n 1 | cut -d' ' -f1)"
+init_pid="$(tail -n 1 $LOG | cut -d' ' -f1)"
+grep -E -v "^($parent_pid|$init_pid) " "$LOG" | uniq > "$OUT"
+match_diff "$OUT" "$EXP"
diff --git a/tests/gettid.c b/tests/gettid.c
index d38918dd..314d9c2c 100644
--- a/tests/gettid.c
+++ b/tests/gettid.c
@@ -9,11 +9,17 @@
 #include <stdio.h>
 #include <unistd.h>
 #include "scno.h"
+#include "pidns.h"
 
 int
 main(void)
 {
-	printf("gettid() = %ld\n", syscall(__NR_gettid));
+	PIDNS_TEST_INIT;
+
+	pidns_print_leader();
+	printf("gettid() = %d%s\n", (int) syscall(__NR_gettid),
+		pidns_pid2str(PT_TID));
+	pidns_print_leader();
 	puts("+++ exited with 0 +++");
 	return 0;
 }
diff --git a/tests/ioctl_block--pidns-translation.c b/tests/ioctl_block--pidns-translation.c
new file mode 100644
index 00000000..5eed6076
--- /dev/null
+++ b/tests/ioctl_block--pidns-translation.c
@@ -0,0 +1,2 @@
+#define PIDNS_TRANSLATION
+#include "ioctl_block.c"
diff --git a/tests/ioctl_block--pidns-translation.test b/tests/ioctl_block--pidns-translation.test
new file mode 100755
index 00000000..bb45f695
--- /dev/null
+++ b/tests/ioctl_block--pidns-translation.test
@@ -0,0 +1,24 @@
+#!/bin/sh
+#
+# Check ioctl syscall decoding.
+#
+# Copyright (c) 2020 The strace developers.
+# All rights reserved.
+#
+# SPDX-License-Identifier: LGPL-2.1-or-later
+
+. "${srcdir=.}/init.sh"
+
+require_min_kernel_version_or_skip 4.9
+
+check_prog head
+check_prog tail
+check_prog cut
+check_prog grep
+
+run_prog > /dev/null
+run_strace --pidns-translation -f -a16 -e trace=ioctl $@ $args > "$EXP"
+parent_pid="$(tail -n 2 $LOG | head -n 1 | cut -d' ' -f1)"
+init_pid="$(tail -n 1 $LOG | cut -d' ' -f1)"
+grep -E -v "^($parent_pid|$init_pid) |ioctl\([0123][,<]" "$LOG" > "$OUT"
+match_diff "$OUT" "$EXP"
diff --git a/tests/ioctl_block.c b/tests/ioctl_block.c
index 0afe27f7..8a345f4e 100644
--- a/tests/ioctl_block.c
+++ b/tests/ioctl_block.c
@@ -9,7 +9,9 @@
  */
 
 #include "tests.h"
+#include "pidns.h"
 #include <errno.h>
+#include <unistd.h>
 #include <inttypes.h>
 #include <stdio.h>
 #include <string.h>
@@ -41,12 +43,15 @@ static struct xlat_data block_argless[] = {
 #define TEST_NULL_ARG(cmd)						\
 	do {								\
 		ioctl(-1, cmd, 0);					\
+		pidns_print_leader();					\
 		printf("ioctl(-1, %s, NULL) = -1 EBADF (%m)\n", #cmd);	\
 	} while (0)
 
 int
 main(void)
 {
+	PIDNS_TEST_INIT;
+
 	TEST_NULL_ARG(BLKBSZGET);
 	TEST_NULL_ARG(BLKBSZSET);
 	TEST_NULL_ARG(BLKFRAGET);
@@ -91,18 +96,22 @@ main(void)
 #endif
 
 	ioctl(-1, BLKRASET, lmagic);
+	pidns_print_leader();
 	printf("ioctl(-1, BLKRASET, %lu) = -1 EBADF (%m)\n", lmagic);
 
 	ioctl(-1, BLKFRASET, lmagic);
+	pidns_print_leader();
 	printf("ioctl(-1, BLKFRASET, %lu) = -1 EBADF (%m)\n", lmagic);
 
 	TAIL_ALLOC_OBJECT_CONST_PTR(int, val_int);
 	*val_int = magic;
 
 	ioctl(-1, BLKROSET, val_int);
+	pidns_print_leader();
 	printf("ioctl(-1, BLKROSET, [%d]) = -1 EBADF (%m)\n", *val_int);
 
 	ioctl(-1, BLKBSZSET, val_int);
+	pidns_print_leader();
 	printf("ioctl(-1, BLKBSZSET, [%d]) = -1 EBADF (%m)\n", *val_int);
 
 	uint64_t *pair_int64 = tail_alloc(sizeof(*pair_int64) * 2);
@@ -111,18 +120,21 @@ main(void)
 
 #ifdef BLKDISCARD
 	ioctl(-1, BLKDISCARD, pair_int64);
+	pidns_print_leader();
 	printf("ioctl(-1, BLKDISCARD, [%" PRIu64 ", %" PRIu64 "])"
 	       " = -1 EBADF (%m)\n", pair_int64[0], pair_int64[1]);
 #endif
 
 #ifdef BLKSECDISCARD
 	ioctl(-1, BLKSECDISCARD, pair_int64);
+	pidns_print_leader();
 	printf("ioctl(-1, BLKSECDISCARD, [%" PRIu64 ", %" PRIu64 "])"
 	       " = -1 EBADF (%m)\n", pair_int64[0], pair_int64[1]);
 #endif
 
 #ifdef BLKZEROOUT
 	ioctl(-1, BLKZEROOUT, pair_int64);
+	pidns_print_leader();
 	printf("ioctl(-1, BLKZEROOUT, [%" PRIu64 ", %" PRIu64 "])"
 	       " = -1 EBADF (%m)\n", pair_int64[0], pair_int64[1]);
 #endif
@@ -134,6 +146,7 @@ main(void)
 	blkpg->data = (void *) (unsigned long) 0xcafef00dfffffeedULL;
 
 	ioctl(-1, BLKPG, blkpg);
+	pidns_print_leader();
 	printf("ioctl(-1, BLKPG, {op=%s, flags=%d, datalen=%d"
 	       ", data=%#lx}) = -1 EBADF (%m)\n",
 	       "BLKPG_RESIZE_PARTITION", blkpg->flags, blkpg->datalen,
@@ -149,6 +162,7 @@ main(void)
 	blkpg->data = bp;
 
 	ioctl(-1, BLKPG, blkpg);
+	pidns_print_leader();
 	printf("ioctl(-1, BLKPG, {op=%s, flags=%d, datalen=%d"
 	       ", data={start=%lld, length=%lld, pno=%d"
 	       ", devname=\"%.*s\"..., volname=\"%.*s\"...}})"
@@ -162,25 +176,31 @@ main(void)
 #if defined BLKTRACESETUP && defined HAVE_STRUCT_BLK_USER_TRACE_SETUP
 	TAIL_ALLOC_OBJECT_CONST_PTR(struct blk_user_trace_setup, buts);
 	fill_memory(buts, sizeof(*buts));
+	buts->pid = getpid();
 
 	ioctl(-1, BLKTRACESETUP, buts);
+	pidns_print_leader();
 	printf("ioctl(-1, BLKTRACESETUP, {act_mask=%hu, buf_size=%u, buf_nr=%u"
-	       ", start_lba=%" PRI__u64 ", end_lba=%" PRI__u64 ", pid=%d})"
+	       ", start_lba=%" PRI__u64 ", end_lba=%" PRI__u64 ", pid=%d%s})"
 	       " = -1 EBADF (%m)\n",
 	       buts->act_mask, buts->buf_size, buts->buf_nr,
-	       buts->start_lba, buts->end_lba, buts->pid);
+	       buts->start_lba, buts->end_lba, buts->pid,
+	       pidns_pid2str(PT_TGID));
 #endif
 
 	unsigned int i;
 	for (i = 0; i < ARRAY_SIZE(block_argless); ++i) {
 		ioctl(-1, (unsigned long) block_argless[i].val, lmagic);
+		pidns_print_leader();
 		printf("ioctl(-1, %s) = -1 EBADF (%m)\n", block_argless[i].str);
 	}
 
 	ioctl(-1, _IOC(_IOC_READ, 0x12, 0xfe, 0xff), lmagic);
+	pidns_print_leader();
 	printf("ioctl(-1, %s, %#lx) = -1 EBADF (%m)\n",
 	       "_IOC(_IOC_READ, 0x12, 0xfe, 0xff)", lmagic);
 
+	pidns_print_leader();
 	puts("+++ exited with 0 +++");
 	return 0;
 }
diff --git a/tests/ioprio--pidns-translation.c b/tests/ioprio--pidns-translation.c
new file mode 100644
index 00000000..bcb49a8b
--- /dev/null
+++ b/tests/ioprio--pidns-translation.c
@@ -0,0 +1,2 @@
+#define PIDNS_TRANSLATION
+#include "ioprio.c"
diff --git a/tests/ioprio.c b/tests/ioprio.c
index 5e1e1194..110df063 100644
--- a/tests/ioprio.c
+++ b/tests/ioprio.c
@@ -9,8 +9,8 @@
  */
 
 #include "tests.h"
-
 #include "scno.h"
+#include "pidns.h"
 
 #if defined(__NR_ioprio_get) && defined(__NR_ioprio_set)
 
@@ -30,12 +30,18 @@ enum {
 int
 main(void)
 {
+	PIDNS_TEST_INIT;
+
 	static const kernel_ulong_t bogus_which =
 		(kernel_ulong_t) 0xdeadfacefa57beefULL;
 	static const kernel_ulong_t bogus_who =
 		(kernel_ulong_t) 0xbadc0dedda7a1057ULL;
 	static const kernel_ulong_t bogus_ioprio =
 		(kernel_ulong_t) 0xdec0ded1facefeedULL;
+
+	const int pid = getpid();
+	const int pgid = getpgid(0);
+
 # if !XLAT_RAW
 	static const char * const bogus_ioprio_str =
 		"IOPRIO_PRIO_VALUE(0x7d677 /* IOPRIO_CLASS_??? */, 7917)";
@@ -46,6 +52,7 @@ main(void)
 
 	rc = syscall(__NR_ioprio_get, bogus_which, bogus_who);
 	errstr = sprintrc(rc);
+	pidns_print_leader();
 # if XLAT_RAW
 	printf("ioprio_get(%#x, %d) = %s\n",
 	       (int) bogus_which, (int) bogus_who, errstr);
@@ -54,42 +61,52 @@ main(void)
 	       (int) bogus_which, (int) bogus_who, errstr);
 # endif
 
-	rc = syscall(__NR_ioprio_get, 1, 0);
+	rc = syscall(__NR_ioprio_get, 1, pid);
 	errstr = sprintrc(rc);
+	pidns_print_leader();
+	printf("ioprio_get(");
 # if XLAT_RAW
-	printf("ioprio_get(0x1, 0) = %s\n", errstr);
+	printf("0x1, ");
+# elif XLAT_VERBOSE
+	printf("0x1 /* IOPRIO_WHO_PROCESS */, ");
 # else /* XLAT_ABBREV */
-#  if XLAT_VERBOSE
-	printf("ioprio_get(0x1 /* IOPRIO_WHO_PROCESS */, 0) = %s", errstr);
-#  else
-	printf("ioprio_get(IOPRIO_WHO_PROCESS, 0) = %s", errstr);
-#  endif
+	printf("IOPRIO_WHO_PROCESS, ");
+# endif
+	printf("%d%s) = %s", pid, pidns_pid2str(PT_TGID), errstr);
+# if !XLAT_RAW
 	if (rc >= 0) {
 		printf(" (IOPRIO_PRIO_VALUE(");
 		printxval(ioprio_class, (unsigned int) rc >> 13,
 			  "IOPRIO_CLASS_???");
 		printf(", %u))", (unsigned int) rc & 0x1fff);
 	}
-	puts("");
 # endif
+	puts("");
 
-	rc = syscall(__NR_ioprio_set, 2, 0, 8191);
+	rc = syscall(__NR_ioprio_set, 2, pgid, 8191);
 	errstr = sprintrc(rc);
+	pidns_print_leader();
+	printf("ioprio_set(");
 # if XLAT_RAW
-	printf("ioprio_set(%#x, 0, 8191) = %s\n", 2, errstr);
+	printf("%#x", 2);
 # elif XLAT_VERBOSE
-	printf("ioprio_set(%#x /* IOPRIO_WHO_PGRP */, 0, 8191"
-	       " /* IOPRIO_PRIO_VALUE(0 /* IOPRIO_CLASS_NONE */, 8191) */)"
-	       " = %s\n",
-	       2, errstr);
+	printf("%#x /* IOPRIO_WHO_PGRP */", 2);
 # else /* XLAT_ABBREV */
-	printf("ioprio_set(IOPRIO_WHO_PGRP, 0"
-	       ", IOPRIO_PRIO_VALUE(IOPRIO_CLASS_NONE, 8191)) = %s\n",
-	       errstr);
+	printf("IOPRIO_WHO_PGRP");
+# endif
+	printf(", %d%s", pgid, pidns_pid2str(PT_PGID));
+# if XLAT_RAW
+	printf(", 8191)");
+# elif XLAT_VERBOSE
+	printf(", 8191 /* IOPRIO_PRIO_VALUE(0 /* IOPRIO_CLASS_NONE */, 8191) */)");
+# else /* XLAT_ABBREV */
+	printf(", IOPRIO_PRIO_VALUE(IOPRIO_CLASS_NONE, 8191))");
 # endif
+	printf(" = %s\n", errstr);
 
 	rc = syscall(__NR_ioprio_set, bogus_which, bogus_who, bogus_ioprio);
 	errstr = sprintrc(rc);
+	pidns_print_leader();
 # if XLAT_RAW
 	printf("ioprio_set(%#x, %d, %d) = %s\n",
 	       (int) bogus_which, (int) bogus_who, (int) bogus_ioprio,
@@ -104,6 +121,7 @@ main(void)
 	       errstr);
 # endif
 
+	pidns_print_leader();
 	puts("+++ exited with 0 +++");
 
 	return 0;
diff --git a/tests/kcmp-y--pidns-translation.c b/tests/kcmp-y--pidns-translation.c
new file mode 100644
index 00000000..f54d94cc
--- /dev/null
+++ b/tests/kcmp-y--pidns-translation.c
@@ -0,0 +1,2 @@
+#define PIDNS_TRANSLATION
+#include "kcmp-y.c"
diff --git a/tests/kcmp.c b/tests/kcmp.c
index dc5ba9a4..ce705ad0 100644
--- a/tests/kcmp.c
+++ b/tests/kcmp.c
@@ -9,8 +9,8 @@
  */
 
 #include "tests.h"
-
 #include "scno.h"
+#include "pidns.h"
 
 #ifdef __NR_kcmp
 
@@ -101,7 +101,11 @@ do_kcmp(kernel_ulong_t pid1, kernel_ulong_t pid2, kernel_ulong_t type,
 	rc = syscall(__NR_kcmp, pid1, pid2, type, idx1, idx2);
 	errstr = sprintrc(rc);
 
-	printf("kcmp(%d, %d, ", (int) pid1, (int) pid2);
+	const char *pid_str = pidns_pid2str(PT_TGID);
+	pidns_print_leader();
+	printf("kcmp(%d%s, %d%s, ",
+		(int) pid1, (int) pid1 == getpid() ? pid_str : "",
+		(int) pid2, (int) pid2 == getpid() ? pid_str : "");
 
 	if (type_str)
 		printf("%s", type_str);
@@ -146,6 +150,8 @@ do_kcmp(kernel_ulong_t pid1, kernel_ulong_t pid2, kernel_ulong_t type,
 int
 main(void)
 {
+	PIDNS_TEST_INIT;
+
 	static const kernel_ulong_t bogus_pid1 =
 		(kernel_ulong_t) 0xdeadca75face1057ULL;
 	static const kernel_ulong_t bogus_pid2 =
@@ -221,6 +227,7 @@ main(void)
 			(uintptr_t) slot, 1);
 	}
 
+	pidns_print_leader();
 	puts("+++ exited with 0 +++");
 
 	return 0;
diff --git a/tests/kill--pidns-translation.c b/tests/kill--pidns-translation.c
new file mode 100644
index 00000000..4736ca14
--- /dev/null
+++ b/tests/kill--pidns-translation.c
@@ -0,0 +1,2 @@
+#define PIDNS_TRANSLATION
+#include "kill.c"
diff --git a/tests/kill.c b/tests/kill.c
index f7d9341e..17de35da 100644
--- a/tests/kill.c
+++ b/tests/kill.c
@@ -11,6 +11,7 @@
 
 #include "tests.h"
 #include "scno.h"
+#include "pidns.h"
 
 #ifdef __NR_kill
 
@@ -26,6 +27,8 @@ handler(int sig)
 int
 main(void)
 {
+	PIDNS_TEST_INIT;
+
 	const struct sigaction act = { .sa_handler = handler };
 	if (sigaction(SIGALRM, &act, NULL))
 		perror_msg_and_fail("sigaction");
@@ -37,18 +40,23 @@ main(void)
 		perror_msg_and_fail("sigprocmask");
 
 	const int pid = getpid();
+	const char *pid_str = pidns_pid2str(PT_TGID);
 	long rc = syscall(__NR_kill, pid, (long) 0xdefaced00000000ULL | SIGALRM);
-	printf("kill(%d, SIGALRM) = %ld\n", pid, rc);
+	pidns_print_leader();
+	printf("kill(%d%s, SIGALRM) = %ld\n", pid, pid_str, rc);
 
 	const long big_pid = (long) 0xfacefeedbadc0dedULL;
 	const long big_sig = (long) 0xdeadbeefcafef00dULL;
 	rc = syscall(__NR_kill, big_pid, big_sig);
+	pidns_print_leader();
 	printf("kill(%d, %d) = %ld %s (%m)\n",
 	       (int) big_pid, (int) big_sig, rc, errno2name());
 
 	rc = syscall(__NR_kill, (long) 0xdefaced00000000ULL | pid, 0);
-	printf("kill(%d, 0) = %ld\n", pid, rc);
+	pidns_print_leader();
+	printf("kill(%d%s, 0) = %ld\n", pid, pid_str, rc);
 
+	pidns_print_leader();
 	puts("+++ exited with 0 +++");
 	return 0;
 }
diff --git a/tests/migrate_pages--pidns-translation.c b/tests/migrate_pages--pidns-translation.c
new file mode 100644
index 00000000..ec34938d
--- /dev/null
+++ b/tests/migrate_pages--pidns-translation.c
@@ -0,0 +1,2 @@
+#define PIDNS_TRANSLATION
+#include "migrate_pages.c"
diff --git a/tests/migrate_pages.c b/tests/migrate_pages.c
index 2dfba49c..390b490b 100644
--- a/tests/migrate_pages.c
+++ b/tests/migrate_pages.c
@@ -10,6 +10,7 @@
 
 #include "tests.h"
 #include "scno.h"
+#include "pidns.h"
 
 #ifdef __NR_migrate_pages
 
@@ -19,11 +20,21 @@
 int
 main(void)
 {
-	const long pid = (long) 0xfacefeedffffffffULL;
+	PIDNS_TEST_INIT;
+
+	const long pid = (long) 0xfacefeed00000000ULL | getpid();
 	long rc = syscall(__NR_migrate_pages, pid, 0, 0, 0);
-	printf("migrate_pages(%d, 0, NULL, NULL) = %ld %s (%m)\n",
-	       (int) pid, rc, errno2name());
 
+	pidns_print_leader();
+	printf("migrate_pages(%d%s, 0, NULL, NULL) = %ld",
+		(int) pid, pidns_pid2str(PT_TGID), rc);
+
+	if (rc < 0)
+		printf(" %s (%m)\n", errno2name());
+	else
+		printf("\n");
+
+	pidns_print_leader();
 	puts("+++ exited with 0 +++");
 	return 0;
 }
diff --git a/tests/move_pages--pidns-translation.c b/tests/move_pages--pidns-translation.c
new file mode 100644
index 00000000..8498e399
--- /dev/null
+++ b/tests/move_pages--pidns-translation.c
@@ -0,0 +1,2 @@
+#define PIDNS_TRANSLATION
+#include "move_pages.c"
diff --git a/tests/move_pages.c b/tests/move_pages.c
index e00fd1ac..56843158 100644
--- a/tests/move_pages.c
+++ b/tests/move_pages.c
@@ -10,6 +10,7 @@
 
 #include "tests.h"
 #include "scno.h"
+#include "pidns.h"
 
 #ifdef __NR_move_pages
 
@@ -122,15 +123,20 @@ print_status_array(const int *const status, const unsigned long count)
 }
 
 static void
-print_stat_pages(const unsigned long pid, const unsigned long count,
-		 const void **const pages, int *const status)
+print_stat_pages(const unsigned long pid,
+		 const char *pid_str,
+		 const unsigned long count,
+		 const void **const pages,
+		 int *const status)
 {
 	const unsigned long flags = (unsigned long) 0xfacefeed00000002ULL;
 
 	long rc = syscall(__NR_move_pages,
 			  pid, count, pages, NULL, status, flags);
 	const char *errstr = sprintrc(rc);
-	printf("move_pages(%d, %lu, ", (int) pid, count);
+	pidns_print_leader();
+	printf("move_pages(%d%s, %lu, ", (int) pid, pid_str,
+		count);
 	print_page_array(pages, count, 0);
 	printf(", NULL, ");
 	if (rc) {
@@ -152,6 +158,7 @@ print_stat_pages(const unsigned long pid, const unsigned long count,
 
 static void
 print_move_pages(const unsigned long pid,
+		 const char *pid_str,
 		 unsigned long count,
 		 const unsigned int offset,
 		 const void **const pages,
@@ -164,7 +171,9 @@ print_move_pages(const unsigned long pid,
 	long rc = syscall(__NR_move_pages,
 			  pid, count, pages, nodes, status, flags);
 	const char *errstr = sprintrc(rc);
-	printf("move_pages(%d, %lu, ", (int) pid, count);
+	pidns_print_leader();
+	printf("move_pages(%d%s, %lu, ", (int) pid, pid_str,
+		count);
 	print_page_array(pages, count, offset);
 	printf(", ");
 	print_node_array(nodes, count, offset);
@@ -185,8 +194,11 @@ print_move_pages(const unsigned long pid,
 int
 main(void)
 {
+	PIDNS_TEST_INIT;
+
 	const unsigned long pid =
 		(unsigned long) 0xfacefeed00000000ULL | getpid();
+	const char *pid_str = pidns_pid2str(PT_TGID);
 	unsigned long count = 1;
 	const unsigned page_size = get_page_size();
 	const void *const page = tail_alloc(page_size);
@@ -195,40 +207,41 @@ main(void)
 	TAIL_ALLOC_OBJECT_VAR_PTR(int, nodes);
 	TAIL_ALLOC_OBJECT_VAR_PTR(int, status);
 
-	print_stat_pages(pid, 0, pages, status);
-	print_move_pages(pid, 0, 0, pages, nodes, status);
-	print_move_pages(pid, 0, 1, pages + 1, nodes + 1, status + 1);
+	print_stat_pages(pid, pid_str, 0, pages, status);
+	print_move_pages(pid, pid_str, 0, 0, pages, nodes, status);
+	print_move_pages(pid, pid_str, 0, 1, pages + 1, nodes + 1, status + 1);
 
 	*pages = page;
-	print_stat_pages(pid, count, pages, status);
+	print_stat_pages(pid, pid_str, count, pages, status);
 	*nodes = 0xdeadbee1;
-	print_move_pages(pid, count, 0, pages, nodes, status);
-	print_move_pages(pid, count, 1, pages, nodes, status);
+	print_move_pages(pid, pid_str, count, 0, pages, nodes, status);
+	print_move_pages(pid, pid_str, count, 1, pages, nodes, status);
 
 	++count;
 	--status;
 	*(--pages) = efault;
-	print_stat_pages(pid, count, pages, status);
+	print_stat_pages(pid, pid_str, count, pages, status);
 	*(--nodes) = 0xdeadbee2;
-	print_move_pages(pid, count, 0, pages, nodes, status);
-	print_move_pages(pid, count, 1, pages, nodes, status);
+	print_move_pages(pid, pid_str, count, 0, pages, nodes, status);
+	print_move_pages(pid, pid_str, count, 1, pages, nodes, status);
 
 	++count;
 	--status;
 	*(--pages) = nodes;
-	print_stat_pages(pid, count, pages, status);
+	print_stat_pages(pid, pid_str, count, pages, status);
 	*(--nodes) = 0xdeadbee3;
-	print_move_pages(pid, count, 0, pages, nodes, status);
-	print_move_pages(pid, count, 1, pages, nodes, status);
+	print_move_pages(pid, pid_str, count, 0, pages, nodes, status);
+	print_move_pages(pid, pid_str, count, 1, pages, nodes, status);
 
 	++count;
 	--status;
 	*(--pages) = status;
-	print_stat_pages(pid, count, pages, status);
+	print_stat_pages(pid, pid_str, count, pages, status);
 	*(--nodes) = 0xdeadbee4;
-	print_move_pages(pid, count, 0, pages, nodes, status);
-	print_move_pages(pid, count, 1, pages, nodes, status);
+	print_move_pages(pid, pid_str, count, 0, pages, nodes, status);
+	print_move_pages(pid, pid_str, count, 1, pages, nodes, status);
 
+	pidns_print_leader();
 	puts("+++ exited with 0 +++");
 	return 0;
 }
diff --git a/tests/net-sockaddr--pidns-translation.c b/tests/net-sockaddr--pidns-translation.c
new file mode 100644
index 00000000..ff432bf4
--- /dev/null
+++ b/tests/net-sockaddr--pidns-translation.c
@@ -0,0 +1,2 @@
+#define PIDNS_TRANSLATION
+#include "net-sockaddr.c"
diff --git a/tests/net-sockaddr.c b/tests/net-sockaddr.c
index 4fc9da6e..b9cd46fd 100644
--- a/tests/net-sockaddr.c
+++ b/tests/net-sockaddr.c
@@ -9,6 +9,7 @@
  */
 
 #include "tests.h"
+#include "pidns.h"
 #include <stddef.h>
 #include <stdio.h>
 #include <string.h>
@@ -40,18 +41,21 @@ check_un(void)
 	memset(un->sun_path, '0', sizeof(un->sun_path));
 	unsigned int len = sizeof(*un);
 	int ret = connect(-1, (void *) un, len);
+	pidns_print_leader();
 	printf("connect(-1, {sa_family=AF_UNIX, sun_path=\"%.*u\"}"
 	       ", %u) = %d EBADF (%m)\n",
 	       (int) sizeof(un->sun_path), 0, len, ret);
 
 	un->sun_path[1] = 0;
 	ret = connect(-1, (void *) un, len);
+	pidns_print_leader();
 	printf("connect(-1, {sa_family=AF_UNIX, sun_path=\"%u\"}, %u)"
 	       " = %d EBADF (%m)\n", 0, len, ret);
 
 	un->sun_path[0] = 0;
 	un->sun_path[2] = 1;
 	ret = connect(-1, (void *) un, len);
+	pidns_print_leader();
 	printf("connect(-1, {sa_family=AF_UNIX, sun_path=@\"\\0\\001%.*u\"}"
 	       ", %u) = %d EBADF (%m)\n",
 	       (int) sizeof(un->sun_path) - 3, 0, len, ret);
@@ -61,12 +65,14 @@ check_un(void)
 	memset(un->sun_path, '0', sizeof(un->sun_path));
 	len = sizeof(*un) + 2;
 	ret = connect(-1, (void *) un, len);
+	pidns_print_leader();
 	printf("connect(-1, {sa_family=AF_UNIX, sun_path=\"%.*u\"}"
 	       ", %u) = %d EBADF (%m)\n",
 	       (int) sizeof(un->sun_path), 0, len, ret);
 
 	un->sun_path[0] = 0;
 	ret = connect(-1, (void *) un, len);
+	pidns_print_leader();
 	printf("connect(-1, {sa_family=AF_UNIX, sun_path=@\"%.*u\"}"
 	       ", %u) = %d EBADF (%m)\n",
 	       (int) sizeof(un->sun_path) - 1, 0, len, ret);
@@ -75,18 +81,21 @@ check_un(void)
 	un->sun_family = AF_UNIX;
 	len = sizeof(*un) - 2;
 	ret = connect(-1, (void *) un, len);
+	pidns_print_leader();
 	printf("connect(-1, {sa_family=AF_UNIX, sun_path=\"%.*u\"}"
 	       ", %u) = %d EBADF (%m)\n",
 	       (int) sizeof(un->sun_path) - 2, 0, len, ret);
 
 	un->sun_path[0] = 0;
 	ret = connect(-1, (void *) un, len);
+	pidns_print_leader();
 	printf("connect(-1, {sa_family=AF_UNIX, sun_path=@\"%.*u\"}"
 	       ", %u) = %d EBADF (%m)\n",
 	       (int) sizeof(un->sun_path) - 3, 0, len, ret);
 
 	len = sizeof(*un);
 	ret = connect(-1, (void *) un, len);
+	pidns_print_leader();
 	printf("connect(-1, %p, %u) = %d EBADF (%m)\n", un, len, ret);
 
 	un = tail_alloc(sizeof(struct sockaddr_storage));
@@ -94,12 +103,14 @@ check_un(void)
 	memset(un->sun_path, '0', sizeof(un->sun_path));
 	len = sizeof(struct sockaddr_storage) + 1;
 	ret = connect(-1, (void *) un, len);
+	pidns_print_leader();
 	printf("connect(-1, {sa_family=AF_UNIX, sun_path=\"%.*u\"}"
 	       ", %u) = %d EBADF (%m)\n",
 	       (int) sizeof(un->sun_path), 0, len, ret);
 
 	un->sun_path[0] = 0;
 	ret = connect(-1, (void *) un, len);
+	pidns_print_leader();
 	printf("connect(-1, {sa_family=AF_UNIX, sun_path=@\"%.*u\"}"
 	       ", %u) = %d EBADF (%m)\n",
 	       (int) sizeof(un->sun_path) - 1, 0, len, ret);
@@ -117,6 +128,7 @@ check_in(void)
 	in->sin_addr.s_addr = inet_addr(h_addr);
 	unsigned int len = sizeof(*in);
 	int ret = connect(-1, (void *) in, len);
+	pidns_print_leader();
 	printf("connect(-1, {sa_family=AF_INET, sin_port=htons(%hu)"
 	       ", sin_addr=inet_addr(\"%s\")}, %u) = %d EBADF (%m)\n",
 	       h_port, h_addr, len, ret);
@@ -127,6 +139,7 @@ check_in(void)
 	in->sin_addr.s_addr = inet_addr(h_addr);
 	len = sizeof(*in) + 4;
 	ret = connect(-1, (void *) in, len);
+	pidns_print_leader();
 	printf("connect(-1, {sa_family=AF_INET, sin_port=htons(%hu)"
 	       ", sin_addr=inet_addr(\"%s\")}, %u) = %d EBADF (%m)\n",
 	       h_port, h_addr, len, ret);
@@ -137,6 +150,7 @@ check_in(void)
 	in->sin_addr.s_addr = 0;
 	len = sizeof(*in) - 4;
 	ret = connect(-1, (void *) in, len);
+	pidns_print_leader();
 	printf("connect(-1, {sa_family=AF_INET, sa_data=\"%s\"}, %u)"
 	       " = %d EBADF (%m)\n",
 	       "\\0\\0\\0\\0\\0\\0\\377\\377\\377\\377",
@@ -144,6 +158,7 @@ check_in(void)
 
 	len = sizeof(*in);
 	ret = connect(-1, (void *) in, len);
+	pidns_print_leader();
 	printf("connect(-1, %p, %u) = %d EBADF (%m)\n", in, len, ret);
 }
 
@@ -155,6 +170,7 @@ check_in6_linklocal(struct sockaddr_in6 *const in6, const char *const h_addr)
 	in6->sin6_scope_id = 0xfacefeed;
 	unsigned int len = sizeof(*in6);
 	int ret = connect(-1, (void *) in6, len);
+	pidns_print_leader();
 	printf("connect(-1, {sa_family=AF_INET6, sin6_port=htons(%hu)"
 	       ", sin6_flowinfo=htonl(%u)"
 	       ", inet_pton(AF_INET6, \"%s\", &sin6_addr)"
@@ -166,7 +182,8 @@ check_in6_linklocal(struct sockaddr_in6 *const in6, const char *const h_addr)
 	in6->sin6_scope_id = ifindex_lo();
 	if (in6->sin6_scope_id) {
 		ret = connect(-1, (void *) in6, len);
-		printf("connect(-1, {sa_family=AF_INET6, sin6_port=htons(%hu)"
+		pidns_print_leader();
+	printf("connect(-1, {sa_family=AF_INET6, sin6_port=htons(%hu)"
 		       ", sin6_flowinfo=htonl(%u)"
 		       ", inet_pton(AF_INET6, \"%s\", &sin6_addr)"
 		       ", sin6_scope_id=%s}, %u)"
@@ -191,6 +208,7 @@ check_in6(void)
 	in6->sin6_scope_id = 0xfacefeed;
 	unsigned int len = sizeof(*in6);
 	int ret = connect(-1, (void *) in6, len);
+	pidns_print_leader();
 	printf("connect(-1, {sa_family=AF_INET6, sin6_port=htons(%hu)"
 	       ", sin6_flowinfo=htonl(%u)"
 	       ", inet_pton(AF_INET6, \"%s\", &sin6_addr)"
@@ -209,6 +227,7 @@ check_in6(void)
 	in6->sin6_scope_id = 0xfacefeed;
 	len = sizeof(*in6) + 4;
 	ret = connect(-1, (void *) in6, len);
+	pidns_print_leader();
 	printf("connect(-1, {sa_family=AF_INET6, sin6_port=htons(%hu)"
 	       ", sin6_flowinfo=htonl(%u)"
 	       ", inet_pton(AF_INET6, \"%s\", &sin6_addr)"
@@ -223,6 +242,7 @@ check_in6(void)
 	inet_pton(AF_INET6, h_addr, &in6->sin6_addr);
 	len = sizeof(*in6) - sizeof(in6->sin6_scope_id);
 	ret = connect(-1, (void *) in6, len);
+	pidns_print_leader();
 	printf("connect(-1, {sa_family=AF_INET6, sin6_port=htons(%hu)"
 	       ", sin6_flowinfo=htonl(%u)"
 	       ", inet_pton(AF_INET6, \"%s\", &sin6_addr)}, %u)"
@@ -236,6 +256,7 @@ check_in6(void)
 	memset(&in6->sin6_addr, '0', sizeof(in6->sin6_addr) - 4);
 	len = sizeof(*in6) - sizeof(in6->sin6_scope_id) - 4;
 	ret = connect(-1, (void *) in6, len);
+	pidns_print_leader();
 	printf("connect(-1, {sa_family=AF_INET6"
 	       ", sa_data=\"\\0\\0\\0\\0\\0\\000%.*u\"}, %u)"
 	       " = %d EBADF (%m)\n",
@@ -244,6 +265,7 @@ check_in6(void)
 
 	len = sizeof(*in6) - sizeof(in6->sin6_scope_id);
 	ret = connect(-1, (void *) in6, len);
+	pidns_print_leader();
 	printf("connect(-1, %p, %u) = %d EBADF (%m)\n", in6, len, ret);
 }
 
@@ -262,6 +284,7 @@ check_ipx(void)
 	void *ipx = tail_memdup(&c_ipx, sizeof(c_ipx));
 	unsigned int len = sizeof(c_ipx);
 	int ret = connect(-1, ipx, len);
+	pidns_print_leader();
 	printf("connect(-1, {sa_family=AF_IPX, sipx_port=htons(%u)"
 	       ", sipx_network=htonl(%#x)"
 	       ", sipx_node=[%#02x, %#02x, %#02x, %#02x, %#02x, %#02x]"
@@ -316,18 +339,21 @@ check_ax25(void)
 	fill_memory(sax, size);
 	sax->fsa_ax25.sax25_family = AF_AX25;
 	rc = connect(-1, sax_void, sizeof(struct sockaddr_ax25) - 1);
+	pidns_print_leader();
 	printf("connect(-1, {sa_family=AF_AX25, sa_data=\"\\202\\203\\204\\205"
 	       "\\206\\207\\210\\211\\212\\213\\214\\215\\216\"}, %zu) = %s\n",
 	       sizeof(struct sockaddr_ax25) - 1, sprintrc(rc));
 
 	memcpy(sax, &ax25, sizeof(ax25));
 	rc = connect(-1, sax_void, sizeof(struct sockaddr_ax25));
+	pidns_print_leader();
 	printf("connect(-1, {sa_family=AF_AX25, fsa_ax25={sax25_call=VALID-13"
 	       ", sax25_ndigis=8}, fsa_digipeater=[/* ??? */]}, %zu) = %s\n",
 	       sizeof(struct sockaddr_ax25), sprintrc(rc));
 
 	sax->fsa_ax25.sax25_ndigis = 0;
 	rc = connect(-1, sax_void, sizeof(struct sockaddr_ax25));
+	pidns_print_leader();
 	printf("connect(-1, {sa_family=AF_AX25, sax25_call=VALID-13"
 	       ", sax25_ndigis=0}, %zu) = %s\n",
 	       sizeof(struct sockaddr_ax25), sprintrc(rc));
@@ -335,6 +361,7 @@ check_ax25(void)
 	sax->fsa_ax25.sax25_ndigis = 8;
 	size = sizeof(struct sockaddr_ax25) + sizeof(ax25_address) * 3 + 1;
 	rc = connect(-1, sax_void, size);
+	pidns_print_leader();
 	printf("connect(-1, {sa_family=AF_AX25, fsa_ax25={sax25_call=VALID-13"
 	       ", sax25_ndigis=8}, fsa_digipeater"
 	       "=[{ax25_call=\"\\xa6\\xa0\\x82\\x40\\x86\\x8a\\x00\""
@@ -348,6 +375,7 @@ check_ax25(void)
 	sax->fsa_digipeater[2].ax25_call[6] = 0x4;
 	size = sizeof(struct sockaddr_ax25) + sizeof(ax25_address) * 4;
 	rc = connect(-1, sax_void, size);
+	pidns_print_leader();
 	printf("connect(-1, {sa_family=AF_AX25, fsa_ax25={sax25_call=VALID-13"
 	       ", sax25_ndigis=8}, fsa_digipeater"
 	       "=[{ax25_call=\"\\xa6\\xa0\\x82\\x40\\x86\\x8a\\x00\""
@@ -365,7 +393,8 @@ check_ax25(void)
 	for (size_t i = 0; i < 3; i++) {
 		size = sizeof(ax25) + sizeof(ax25_address) * (i / 2);
 		rc = connect(-1, sax_void, size);
-		printf("connect(-1, {sa_family=AF_AX25"
+		pidns_print_leader();
+	printf("connect(-1, {sa_family=AF_AX25"
 		       ", fsa_ax25={sax25_call=VALID-13, sax25_ndigis=%d}"
 		       ", fsa_digipeater=[VALID2-7, OK-15, %s /* FINE-2 */"
 		       ", {ax25_call=\"\\xe6\\xda\\xc2\\xd8\\xd8\\xe6\\x12\""
@@ -427,13 +456,15 @@ check_x25(void)
 	long rc;
 
 	rc = connect(-1, x25_void, sizeof(c_x25) - 1);
+	pidns_print_leader();
 	printf("connect(-1, {sa_family=AF_X25"
 	       ", sa_data=\"0123456789abcde\"}, %zu) = %s\n",
 	       sizeof(c_x25) - 1, sprintrc(rc));
 
 	for (size_t i = 0; i < 2; i++) {
 		rc = connect(-1, x25_void, sizeof(c_x25) + i);
-		printf("connect(-1, {sa_family=AF_X25"
+		pidns_print_leader();
+	printf("connect(-1, {sa_family=AF_X25"
 		       ", sx25_addr={x25_addr=\"0123456789abcde\"...}"
 		       "}, %zu) = %s\n",
 		       sizeof(c_x25) + i, sprintrc(rc));
@@ -442,6 +473,7 @@ check_x25(void)
 	struct sockaddr_x25 *const x25 = x25_void;
 	x25->sx25_addr.x25_addr[10] = '\0';
 	rc = connect(-1, x25_void, sizeof(c_x25));
+	pidns_print_leader();
 	printf("connect(-1, {sa_family=AF_X25"
 	       ", sx25_addr={x25_addr=\"0123456789\"}"
 	       "}, %zu) = %s\n",
@@ -457,19 +489,21 @@ check_nl(void)
 	nl->nl_groups = 0xfacefeed;
 	unsigned int len = sizeof(*nl);
 	int ret = connect(-1, (void *) nl, len);
+	pidns_print_leader();
 	printf("connect(-1, {sa_family=AF_NETLINK, nl_pid=%d"
 	       ", nl_groups=%#08x}, %u) = %d EBADF (%m)\n",
 	       nl->nl_pid, nl->nl_groups, len, ret);
 
 	nl = ((void *) nl) - 4;
 	nl->nl_family = AF_NETLINK;
-	nl->nl_pid = 1234567890;
+	nl->nl_pid = getpid();
 	nl->nl_groups = 0xfacefeed;
 	len = sizeof(*nl) + 4;
 	ret = connect(-1, (void *) nl, len);
-	printf("connect(-1, {sa_family=AF_NETLINK, nl_pid=%d"
+	pidns_print_leader();
+	printf("connect(-1, {sa_family=AF_NETLINK, nl_pid=%d%s"
 	       ", nl_groups=%#08x}, %u) = %d EBADF (%m)\n",
-	       nl->nl_pid, nl->nl_groups, len, ret);
+	       nl->nl_pid, pidns_pid2str(PT_TGID), nl->nl_groups, len, ret);
 }
 
 static void
@@ -487,6 +521,7 @@ check_ll(void)
 	void *ll = tail_memdup(&c_ll, sizeof(c_ll));
 	unsigned int len = sizeof(c_ll);
 	int ret = connect(-1, ll, len);
+	pidns_print_leader();
 	printf("connect(-1, {sa_family=AF_PACKET"
 	       ", sll_protocol=htons(ETH_P_ALL)"
 	       ", sll_ifindex=%u, sll_hatype=ARPHRD_ETHER"
@@ -502,6 +537,7 @@ check_ll(void)
 
 	((struct sockaddr_ll *) ll)->sll_halen++;
 	ret = connect(-1, ll, len);
+	pidns_print_leader();
 	printf("connect(-1, {sa_family=AF_PACKET"
 	       ", sll_protocol=htons(ETH_P_ALL)"
 	       ", sll_ifindex=%u, sll_hatype=ARPHRD_ETHER"
@@ -517,6 +553,7 @@ check_ll(void)
 
 	((struct sockaddr_ll *) ll)->sll_halen = 0;
 	ret = connect(-1, ll, len);
+	pidns_print_leader();
 	printf("connect(-1, {sa_family=AF_PACKET"
 	       ", sll_protocol=htons(ETH_P_ALL)"
 	       ", sll_ifindex=%u, sll_hatype=ARPHRD_ETHER"
@@ -526,7 +563,8 @@ check_ll(void)
 	((struct sockaddr_ll *) ll)->sll_ifindex = ifindex_lo();
 	if (((struct sockaddr_ll *) ll)->sll_ifindex) {
 		ret = connect(-1, ll, len);
-		printf("connect(-1, {sa_family=AF_PACKET"
+	pidns_print_leader();
+	printf("connect(-1, {sa_family=AF_PACKET"
 		       ", sll_protocol=htons(ETH_P_ALL)"
 		       ", sll_ifindex=%s"
 		       ", sll_hatype=ARPHRD_ETHER"
@@ -549,11 +587,13 @@ check_hci(void)
 	unsigned int len = sizeof(*hci);
 
 	int ret = connect(-1, (void *) hci, 4);
+	pidns_print_leader();
 	printf("connect(-1, {sa_family=AF_BLUETOOTH, hci_dev=htobs(%hu)"
 	       "}, 4) = %d EBADF (%m)\n",
 	       h_port, ret);
 
 	ret = connect(-1, (void *) hci, len);
+	pidns_print_leader();
 	printf("connect(-1, {sa_family=AF_BLUETOOTH, hci_dev=htobs(%hu)"
 # ifdef HAVE_STRUCT_SOCKADDR_HCI_HCI_CHANNEL
 	       ", hci_channel=HCI_CHANNEL_RAW"
@@ -572,6 +612,7 @@ check_sco(void)
 	void *sco = tail_memdup(&c_sco, sizeof(c_sco));
 	unsigned int len = sizeof(c_sco);
 	int ret = connect(-1, sco, len);
+	pidns_print_leader();
 	printf("connect(-1, {sa_family=AF_BLUETOOTH"
 	       ", sco_bdaddr=%02x:%02x:%02x:%02x:%02x:%02x"
 	       "}, %u) = %d EBADF (%m)\n",
@@ -592,6 +633,7 @@ check_rc(void)
 	void *rc = tail_memdup(&c_rc, sizeof(c_rc));
 	unsigned int len = sizeof(c_rc);
 	int ret = connect(-1, rc, len);
+	pidns_print_leader();
 	printf("connect(-1, {sa_family=AF_BLUETOOTH"
 	       ", rc_bdaddr=%02x:%02x:%02x:%02x:%02x:%02x"
 	       ", rc_channel=%u}, %u) = %d EBADF (%m)\n",
@@ -619,6 +661,7 @@ check_l2(void)
 	unsigned int len = sizeof(c_l2);
 
 	int ret = connect(-1, l2, len);
+	pidns_print_leader();
 	printf("connect(-1, {sa_family=AF_BLUETOOTH"
 	       ", l2_psm=htobs(L2CAP_PSM_DYN_START + %hu)"
 	       ", l2_bdaddr=%02x:%02x:%02x:%02x:%02x:%02x"
@@ -640,6 +683,7 @@ check_l2(void)
 # endif
 	memcpy(l2, &c_l2, sizeof(c_l2));
 	ret = connect(-1, l2, len);
+	pidns_print_leader();
 	printf("connect(-1, {sa_family=AF_BLUETOOTH"
 	       ", l2_psm=htobs(L2CAP_PSM_SDP)"
 	       ", l2_bdaddr=%02x:%02x:%02x:%02x:%02x:%02x"
@@ -660,6 +704,7 @@ check_l2(void)
 # endif
 	memcpy(l2, &c_l2, sizeof(c_l2));
 	ret = connect(-1, l2, len);
+	pidns_print_leader();
 	printf("connect(-1, {sa_family=AF_BLUETOOTH"
 	       ", l2_psm=htobs(0xbad /* L2CAP_PSM_??? */)"
 	       ", l2_bdaddr=%02x:%02x:%02x:%02x:%02x:%02x"
@@ -677,6 +722,7 @@ check_l2(void)
 	c_l2.l2_cid = htobs(0xffff);
 	memcpy(l2, &c_l2, 12);
 	ret = connect(-1, l2, 12);
+	pidns_print_leader();
 	printf("connect(-1, {sa_family=AF_BLUETOOTH"
 	       ", l2_psm=htobs(L2CAP_PSM_AUTO_END)"
 	       ", l2_bdaddr=%02x:%02x:%02x:%02x:%02x:%02x"
@@ -700,6 +746,7 @@ check_raw(void)
 	u.sa->sa_family = 0xff;
 	unsigned int len = sizeof(*u.st) + 8;
 	int ret = connect(-1, (void *) u.st, len);
+	pidns_print_leader();
 	printf("connect(-1, {sa_family=%#x /* AF_??? */, sa_data=\"%.*u\"}"
 	       ", %u) = %d EBADF (%m)\n", u.sa->sa_family,
 	       (int) (sizeof(*u.st) - sizeof(u.sa->sa_family)), 0, len, ret);
@@ -707,11 +754,13 @@ check_raw(void)
 	u.sa->sa_family = 0;
 	len = sizeof(u.sa->sa_family) + 1;
 	ret = connect(-1, (void *) u.st, len);
+	pidns_print_leader();
 	printf("connect(-1, {sa_family=AF_UNSPEC, sa_data=\"0\"}, %u)"
 	       " = %d EBADF (%m)\n", len, ret);
 
 	u.sa->sa_family = AF_BLUETOOTH;
 	ret = connect(-1, (void *) u.st, len);
+	pidns_print_leader();
 	printf("connect(-1, {sa_family=AF_BLUETOOTH, sa_data=\"0\"}, %u)"
 	       " = %d EBADF (%m)\n", len, ret);
 }
@@ -719,6 +768,8 @@ check_raw(void)
 int
 main(void)
 {
+	PIDNS_TEST_INIT;
+
 	check_un();
 	check_in();
 	check_in6();
@@ -735,6 +786,7 @@ main(void)
 #endif
 	check_raw();
 
+	pidns_print_leader();
 	puts("+++ exited with 0 +++");
 	return 0;
 }
diff --git a/tests/netlink_audit--pidns-translation.c b/tests/netlink_audit--pidns-translation.c
new file mode 100644
index 00000000..e08f9168
--- /dev/null
+++ b/tests/netlink_audit--pidns-translation.c
@@ -0,0 +1,2 @@
+#define PIDNS_TRANSLATION
+#include "netlink_audit.c"
diff --git a/tests/netlink_audit--pidns-translation.test b/tests/netlink_audit--pidns-translation.test
new file mode 100755
index 00000000..fbc32435
--- /dev/null
+++ b/tests/netlink_audit--pidns-translation.test
@@ -0,0 +1,13 @@
+#!/bin/sh
+#
+# Check decoding of NETLINK_SOCK_DIAG protocol
+#
+# Copyright (c) 2020 The strace developers.
+# All rights reserved.
+#
+# SPDX-License-Identifier: LGPL-2.1-or-later
+
+. "${srcdir=.}/init.sh"
+
+run_prog ../netlink_netlink_diag
+test_pidns -e trace=sendto "$@"
diff --git a/tests/netlink_audit.c b/tests/netlink_audit.c
index eba609a1..5dfcd786 100644
--- a/tests/netlink_audit.c
+++ b/tests/netlink_audit.c
@@ -7,6 +7,7 @@
  */
 
 #include "tests.h"
+#include "pidns.h"
 #include <stdio.h>
 #include <string.h>
 #include <unistd.h>
@@ -17,18 +18,23 @@
 static void
 test_nlmsg_type(const int fd)
 {
+	PIDNS_TEST_INIT;
+
 	long rc;
 	struct nlmsghdr nlh = {
 		.nlmsg_len = sizeof(nlh),
 		.nlmsg_type = AUDIT_GET,
 		.nlmsg_flags = NLM_F_REQUEST,
+		.nlmsg_pid = getpid(),
 	};
 
 	rc = sendto(fd, &nlh, sizeof(nlh), MSG_DONTWAIT, NULL, 0);
+	pidns_print_leader();
 	printf("sendto(%d, {len=%u, type=AUDIT_GET"
-	       ", flags=NLM_F_REQUEST, seq=0, pid=0}"
+	       ", flags=NLM_F_REQUEST, seq=0, pid=%d%s}"
 	       ", %u, MSG_DONTWAIT, NULL, 0) = %s\n",
-	       fd, nlh.nlmsg_len, (unsigned) sizeof(nlh), sprintrc(rc));
+	       fd, nlh.nlmsg_len, nlh.nlmsg_pid, pidns_pid2str(PT_TGID),
+	       (unsigned) sizeof(nlh), sprintrc(rc));
 }
 
 int main(void)
@@ -39,6 +45,7 @@ int main(void)
 
 	test_nlmsg_type(fd);
 
+	pidns_print_leader();
 	printf("+++ exited with 0 +++\n");
 
 	return 0;
diff --git a/tests/pidfd_open--pidns-translation.c b/tests/pidfd_open--pidns-translation.c
new file mode 100644
index 00000000..c38e37a8
--- /dev/null
+++ b/tests/pidfd_open--pidns-translation.c
@@ -0,0 +1,2 @@
+#define PIDNS_TRANSLATION
+#include "pidfd_open.c"
diff --git a/tests/pidfd_open.c b/tests/pidfd_open.c
index 5860adde..e5d74a91 100644
--- a/tests/pidfd_open.c
+++ b/tests/pidfd_open.c
@@ -10,6 +10,7 @@
 
 #include "tests.h"
 #include "scno.h"
+#include "pidns.h"
 
 #ifdef __NR_pidfd_open
 
@@ -37,6 +38,8 @@ k_pidfd_open(const unsigned int pid, const unsigned int flags)
 int
 main(void)
 {
+	PIDNS_TEST_INIT;
+
 # if defined PATH_TRACING || defined PRINT_PATHS
 	skip_if_unavailable("/proc/self/fd/");
 # endif
@@ -50,16 +53,19 @@ main(void)
 
 	k_pidfd_open(0, 0);
 # ifndef PATH_TRACING
+	pidns_print_leader();
 	printf("pidfd_open(0, 0) = %s\n", errstr);
 # endif
 
 	k_pidfd_open(-1U, 0);
 # ifndef PATH_TRACING
+	pidns_print_leader();
 	printf("pidfd_open(-1, 0) = %s\n", errstr);
 # endif
 
 	k_pidfd_open(0, -1U);
 # ifndef PATH_TRACING
+	pidns_print_leader();
 	printf("pidfd_open(0, %#x) = %s\n", -1U, errstr);
 # endif
 
@@ -68,7 +74,10 @@ main(void)
 
 	k_pidfd_open(pid, flags);
 # ifndef PATH_TRACING
-	printf("pidfd_open(%d, %#x) = %s\n", pid, flags, errstr);
+	const char *pid_str = pidns_pid2str(PT_TGID);
+	pidns_print_leader();
+	printf("pidfd_open(%d%s, %#x) = %s\n",
+		pid, pid_str, flags, errstr);
 # endif
 
 # ifdef PRINT_PATHS
@@ -80,17 +89,19 @@ main(void)
 # endif
 
 # ifndef PATH_TRACING
-	printf("pidfd_open(%d, 0) = "
+	pidns_print_leader();
+	printf("pidfd_open(%d%s, 0) = "
 #  if defined PRINT_PIDFD
-	       "%ld<pid:%d>\n", pid, rc, pid
+	       "%ld<pid:%d>\n", pid, pid_str, rc, pid
 #  elif defined PRINT_PATHS
-	       "%ld<anon_inode:[pidfd]>\n", pid, rc
+	       "%ld<anon_inode:[pidfd]>\n", pid, pid_str, rc
 #  else
-	       "%s\n", pid, errstr
+	       "%s\n", pid, pid_str, errstr
 #  endif
 	       );
 # endif
 
+	pidns_print_leader();
 	puts("+++ exited with 0 +++");
 	return 0;
 }
diff --git a/tests/pidfd_send_signal--pidns-translation.c b/tests/pidfd_send_signal--pidns-translation.c
new file mode 100644
index 00000000..b04f10f5
--- /dev/null
+++ b/tests/pidfd_send_signal--pidns-translation.c
@@ -0,0 +1,2 @@
+#define PIDNS_TRANSLATION
+#include "pidfd_send_signal.c"
diff --git a/tests/pidfd_send_signal.c b/tests/pidfd_send_signal.c
index 38b5bda1..a6b2d28c 100644
--- a/tests/pidfd_send_signal.c
+++ b/tests/pidfd_send_signal.c
@@ -10,6 +10,7 @@
 #include "tests.h"
 #include <unistd.h>
 #include "scno.h"
+#include "pidns.h"
 
 #ifdef __NR_pidfd_send_signal
 
@@ -36,6 +37,8 @@ sys_pidfd_send_signal(int pidfd, int sig, const void *info, int flags)
 int
 main(void)
 {
+	PIDNS_TEST_INIT;
+
 	static const char null_path[] = "/dev/null";
 
 	int fd = open(null_path, O_RDONLY);
@@ -46,19 +49,23 @@ main(void)
 	const void *esi = (const void *) si + 1;
 
 	sys_pidfd_send_signal(fd, SIGUSR1, esi, 0);
+	pidns_print_leader();
 	printf("pidfd_send_signal(%d, SIGUSR1, %p, 0) = %s\n",
 	       fd, esi, errstr);
 
 	si->si_signo = SIGUSR1;
 	si->si_code = SI_QUEUE;
+	si->si_pid = getpid();
 
 	sys_pidfd_send_signal(fd, SIGUSR2, si, -1);
+	pidns_print_leader();
 	printf("pidfd_send_signal(%d, SIGUSR2, {si_signo=SIGUSR1"
-	       ", si_code=SI_QUEUE, si_errno=%u, si_pid=%d, si_uid=%d"
+	       ", si_code=SI_QUEUE, si_errno=%u, si_pid=%d%s, si_uid=%d"
 	       ", si_value={int=%d, ptr=%p}}, %#x) = %s\n",
-	       fd, si->si_errno, si->si_pid, si->si_uid, si->si_int, si->si_ptr,
-	       -1U, errstr);
+	       fd, si->si_errno, si->si_pid, pidns_pid2str(PT_TGID), si->si_uid,
+	       si->si_int, si->si_ptr, -1U, errstr);
 
+	pidns_print_leader();
 	puts("+++ exited with 0 +++");
 	return 0;
 }
diff --git a/tests/prlimit64--pidns-translation.c b/tests/prlimit64--pidns-translation.c
new file mode 100644
index 00000000..3972de66
--- /dev/null
+++ b/tests/prlimit64--pidns-translation.c
@@ -0,0 +1,2 @@
+#define PIDNS_TRANSLATION
+#include "prlimit64.c"
diff --git a/tests/prlimit64.c b/tests/prlimit64.c
index 34201a2b..bc1a80b3 100644
--- a/tests/prlimit64.c
+++ b/tests/prlimit64.c
@@ -19,6 +19,7 @@
 # include <sys/resource.h>
 # include <unistd.h>
 
+# include "pidns.h"
 # include "xlat.h"
 # include "xlat/resources.h"
 
@@ -42,8 +43,11 @@ sprint_rlim(uint64_t lim)
 int
 main(void)
 {
+	PIDNS_TEST_INIT;
+
 	unsigned long pid =
 		(unsigned long) 0xdefaced00000000ULL | (unsigned) getpid();
+	const char *pid_str = pidns_pid2str(PT_TGID);
 	uint64_t *const rlimit = tail_alloc(sizeof(*rlimit) * 2);
 	const struct xlat_data *xlat;
 	size_t i = 0;
@@ -54,18 +58,23 @@ main(void)
 
 		unsigned long res = 0xfacefeed00000000ULL | xlat->val;
 		long rc = syscall(__NR_prlimit64, pid, res, 0, rlimit);
+		pidns_print_leader();
 		if (rc)
-			printf("prlimit64(%d, %s, NULL, %p) = %ld %s (%m)\n",
-			       (unsigned) pid, xlat->str, rlimit,
+			printf("prlimit64(%d%s, %s, NULL, %p) ="
+				     " %ld %s (%m)\n",
+			       (unsigned) pid, pid_str,
+			       xlat->str, rlimit,
 			       rc, errno2name());
 		else
-			printf("prlimit64(%d, %s, NULL"
+			printf("prlimit64(%d%s, %s, NULL"
 			       ", {rlim_cur=%s, rlim_max=%s}) = 0\n",
-			       (unsigned) pid, xlat->str,
+			       (unsigned) pid, pid_str,
+			       xlat->str,
 			       sprint_rlim(rlimit[0]),
 			       sprint_rlim(rlimit[1]));
 	}
 
+	pidns_print_leader();
 	puts("+++ exited with 0 +++");
 	return 0;
 }
diff --git a/tests/process_vm_readv--pidns-translation.c b/tests/process_vm_readv--pidns-translation.c
new file mode 100644
index 00000000..0db29ca2
--- /dev/null
+++ b/tests/process_vm_readv--pidns-translation.c
@@ -0,0 +1,2 @@
+#define PIDNS_TRANSLATION
+#include "process_vm_readv.c"
diff --git a/tests/process_vm_readv_writev.c b/tests/process_vm_readv_writev.c
index 9309135a..44e511dd 100644
--- a/tests/process_vm_readv_writev.c
+++ b/tests/process_vm_readv_writev.c
@@ -12,6 +12,7 @@
 #include <stdio.h>
 #include <unistd.h>
 #include <sys/uio.h>
+#include "pidns.h"
 
 #if OP_WR
 # define in_iovec  rmt_iovec
@@ -121,7 +122,7 @@ print_iov(const struct iovec *iov, const void *arg_ptr, long rc)
 }
 
 static void
-do_call(kernel_ulong_t pid,
+do_call(kernel_ulong_t pid, enum pid_type pid_type,
 	kernel_ulong_t local_iov, const char *local_arg,
 	kernel_ulong_t liovcnt,
 	kernel_ulong_t remote_iov, const char *remote_arg,
@@ -135,7 +136,8 @@ do_call(kernel_ulong_t pid,
 		flags);
 	errstr = sprintrc(rc);
 
-	printf("%s(%d, ", OP_STR, (int) pid);
+	pidns_print_leader();
+	printf("%s(%d%s, ", OP_STR, (int) pid, pidns_pid2str(pid_type));
 
 	if (pr_iov)
 		pr_iov((const struct iovec *) (uintptr_t) local_iov, local_arg,
@@ -164,6 +166,8 @@ ptr_cast(void *ptr)
 int
 main(void)
 {
+	PIDNS_TEST_INIT;
+
 	enum {
 		SIZE_11 = 2,
 		SIZE_12 = 3,
@@ -243,18 +247,18 @@ main(void)
 	fill_memory_ex(data2_out, SIZE_2, SEGM2_BASE, SIZE_2);
 
 
-	do_call(bogus_pid, (kernel_ulong_t) (uintptr_t) ARG_STR(NULL),
+	do_call(bogus_pid, PT_NONE, (kernel_ulong_t) (uintptr_t) ARG_STR(NULL),
 		bogus_iovcnt1, (kernel_ulong_t) (uintptr_t) ARG_STR(NULL),
 		bogus_iovcnt2, bogus_flags, NULL);
 
-	do_call(my_pid, ptr_cast(bogus_iov + ARRAY_SIZE(bogus_iovec)),
+	do_call(my_pid, PT_TGID, ptr_cast(bogus_iov + ARRAY_SIZE(bogus_iovec)),
 		"[]", 0, ptr_cast(in_iov + ARRAY_SIZE(in_iovec)), "[]",
 		0, 0, NULL);
-	do_call(my_pid, ptr_cast(bogus_iov + ARRAY_SIZE(bogus_iovec)), NULL,
-		bogus_iovcnt1, ptr_cast(in_iov + ARRAY_SIZE(in_iovec)), NULL,
-		bogus_iovcnt2, 0, print_iov);
+	do_call(my_pid, PT_TGID, ptr_cast(bogus_iov + ARRAY_SIZE(bogus_iovec)),
+		NULL, bogus_iovcnt1, ptr_cast(in_iov + ARRAY_SIZE(in_iovec)),
+		NULL, bogus_iovcnt2, 0, print_iov);
 
-	do_call(my_pid, ptr_cast(bogus_iov), (char *) &bogus_arg,
+	do_call(my_pid, PT_TGID, ptr_cast(bogus_iov), (char *) &bogus_arg,
 		ARRAY_SIZE(bogus_iovec), ptr_cast(rmt_iov + 2),
 		(char *) &rmt_arg_cut, ARRAY_SIZE(rmt_iovec) - 2, 0, print_iov);
 
@@ -263,7 +267,7 @@ main(void)
 	lcl_arg_cut.check_rc = 1;
 #endif
 
-	do_call(my_pid, ptr_cast(lcl_iov + 2), (char *) &lcl_arg_cut,
+	do_call(my_pid, PT_TGID, ptr_cast(lcl_iov + 2), (char *) &lcl_arg_cut,
 		ARRAY_SIZE(lcl_iovec) - 1, ptr_cast(bogus_iov + 2),
 		(char *) &bogus_arg_cut, ARRAY_SIZE(bogus_iovec) - 1, 0,
 		print_iov);
@@ -273,15 +277,16 @@ main(void)
 	rmt_arg_cut.addr_term = 1;
 	rmt_arg_cut.count = 5;
 
-	do_call(my_pid, ptr_cast(lcl_iov + 2), (char *) &lcl_arg_cut,
+	do_call(my_pid, PT_TGID, ptr_cast(lcl_iov + 2), (char *) &lcl_arg_cut,
 		ARRAY_SIZE(lcl_iovec) - 2, ptr_cast(rmt_iov + 1),
 		(char *) &rmt_arg_cut, ARRAY_SIZE(rmt_iovec), 0, print_iov);
 
 	/* Correct call */
-	do_call(my_pid, ptr_cast(lcl_iov), (char *) &lcl_arg,
+	do_call(my_pid, PT_TGID, ptr_cast(lcl_iov), (char *) &lcl_arg,
 		ARRAY_SIZE(lcl_iovec), ptr_cast(rmt_iov), (char *) &rmt_arg,
 		ARRAY_SIZE(rmt_iovec), 0, print_iov);
 
+	pidns_print_leader();
 	puts("+++ exited with 0 +++");
 
 	return 0;
diff --git a/tests/process_vm_writev--pidns-translation.c b/tests/process_vm_writev--pidns-translation.c
new file mode 100644
index 00000000..9ba6a39b
--- /dev/null
+++ b/tests/process_vm_writev--pidns-translation.c
@@ -0,0 +1,2 @@
+#define PIDNS_TRANSLATION
+#include "process_vm_writev.c"
diff --git a/tests/rt_sigqueueinfo--pidns-translation.c b/tests/rt_sigqueueinfo--pidns-translation.c
new file mode 100644
index 00000000..74bfb464
--- /dev/null
+++ b/tests/rt_sigqueueinfo--pidns-translation.c
@@ -0,0 +1,2 @@
+#define PIDNS_TRANSLATION
+#include "rt_sigqueueinfo.c"
diff --git a/tests/rt_sigqueueinfo.c b/tests/rt_sigqueueinfo.c
index c1693873..e22e4640 100644
--- a/tests/rt_sigqueueinfo.c
+++ b/tests/rt_sigqueueinfo.c
@@ -7,6 +7,7 @@
  */
 
 #include "tests.h"
+#include "pidns.h"
 #include <assert.h>
 #include <stdio.h>
 #include <signal.h>
@@ -15,6 +16,8 @@
 int
 main(void)
 {
+	PIDNS_TEST_INIT;
+
 	struct sigaction sa = {
 		.sa_handler = SIG_IGN
 	};
@@ -22,15 +25,19 @@ main(void)
 		.sival_ptr = (void *) (unsigned long) 0xdeadbeefbadc0dedULL
 	};
 	pid_t pid = getpid();
+	const char *pid_str = pidns_pid2str(PT_TGID);
 
 	assert(sigaction(SIGUSR1, &sa, NULL) == 0);
 	if (sigqueue(pid, SIGUSR1, value))
 		perror_msg_and_skip("sigqueue");
-	printf("rt_sigqueueinfo(%u, SIGUSR1, {si_signo=SIGUSR1, "
-		"si_code=SI_QUEUE, si_pid=%d, si_uid=%d, "
+	pidns_print_leader();
+	printf("rt_sigqueueinfo(%d%s, SIGUSR1, {si_signo=SIGUSR1, "
+		"si_code=SI_QUEUE, si_pid=%d%s, si_uid=%u, "
 		"si_value={int=%d, ptr=%p}}) = 0\n",
-		pid, pid, getuid(), value.sival_int, value.sival_ptr);
-	printf("+++ exited with 0 +++\n");
+		pid, pid_str, pid, pid_str,
+		getuid(), value.sival_int, value.sival_ptr);
+	pidns_print_leader();
+	puts("+++ exited with 0 +++");
 
 	return 0;
 }
diff --git a/tests/rt_tgsigqueueinfo--pidns-translation.c b/tests/rt_tgsigqueueinfo--pidns-translation.c
new file mode 100644
index 00000000..94396f00
--- /dev/null
+++ b/tests/rt_tgsigqueueinfo--pidns-translation.c
@@ -0,0 +1,2 @@
+#define PIDNS_TRANSLATION
+#include "rt_tgsigqueueinfo.c"
diff --git a/tests/rt_tgsigqueueinfo.c b/tests/rt_tgsigqueueinfo.c
index 865c21f6..21d01cbb 100644
--- a/tests/rt_tgsigqueueinfo.c
+++ b/tests/rt_tgsigqueueinfo.c
@@ -10,8 +10,9 @@
 
 #include "tests.h"
 #include "scno.h"
+#include "pidns.h"
 
-#ifdef __NR_rt_tgsigqueueinfo
+#if defined __NR_rt_tgsigqueueinfo && defined __NR_gettid
 
 # include <errno.h>
 # include <signal.h>
@@ -20,11 +21,11 @@
 # include <unistd.h>
 
 static long
-k_tgsigqueueinfo(const pid_t pid, const int sig, const void *const info)
+k_tgsigqueueinfo(const pid_t tgid, const int tid, const int sig, const void *const info)
 {
 	return syscall(__NR_rt_tgsigqueueinfo,
-		       F8ILL_KULONG_MASK | pid,
-		       F8ILL_KULONG_MASK | pid,
+		       F8ILL_KULONG_MASK | tgid,
+		       F8ILL_KULONG_MASK | tid,
 		       F8ILL_KULONG_MASK | sig,
 		       info);
 }
@@ -32,6 +33,8 @@ k_tgsigqueueinfo(const pid_t pid, const int sig, const void *const info)
 int
 main(void)
 {
+	PIDNS_TEST_INIT;
+
 	const struct sigaction sa = {
 		.sa_handler = SIG_IGN
 	};
@@ -48,17 +51,22 @@ main(void)
 	info->si_value.sival_ptr =
 		(void *) (unsigned long) 0xdeadbeeffacefeedULL;
 
-	if (k_tgsigqueueinfo(info->si_pid, SIGUSR1, info))
+	if (k_tgsigqueueinfo(getpid(), syscall(__NR_gettid), SIGUSR1, info))
 		(errno == ENOSYS ? perror_msg_and_skip : perror_msg_and_fail)(
 			"rt_tgsigqueueinfo");
 
-	printf("rt_tgsigqueueinfo(%u, %u, %s, {si_signo=%s"
-		", si_code=SI_QUEUE, si_errno=ENOENT, si_pid=%d"
+	pidns_print_leader();
+	printf("rt_tgsigqueueinfo(%d%s, %d%s, %s, {si_signo=%s"
+		", si_code=SI_QUEUE, si_errno=ENOENT, si_pid=%d%s"
 		", si_uid=%d, si_value={int=%d, ptr=%p}}) = 0\n",
-		info->si_pid, info->si_pid, "SIGUSR1", "SIGUSR1",
-		info->si_pid, info->si_uid, info->si_value.sival_int,
+		info->si_pid, pidns_pid2str(PT_TGID),
+		info->si_pid, pidns_pid2str(PT_TID),
+		"SIGUSR1", "SIGUSR1",
+		info->si_pid, pidns_pid2str(PT_TGID),
+		info->si_uid, info->si_value.sival_int,
 		info->si_value.sival_ptr);
 
+	pidns_print_leader();
 	puts("+++ exited with 0 +++");
 	return 0;
 }
diff --git a/tests/sched_xetaffinity--pidns-translation.c b/tests/sched_xetaffinity--pidns-translation.c
new file mode 100644
index 00000000..814e3989
--- /dev/null
+++ b/tests/sched_xetaffinity--pidns-translation.c
@@ -0,0 +1,2 @@
+#define PIDNS_TRANSLATION
+#include "sched_xetaffinity.c"
diff --git a/tests/sched_xetaffinity.c b/tests/sched_xetaffinity.c
index cebff3ab..2e508ca3 100644
--- a/tests/sched_xetaffinity.c
+++ b/tests/sched_xetaffinity.c
@@ -10,6 +10,7 @@
 
 #include "tests.h"
 #include "scno.h"
+#include "pidns.h"
 #include <sched.h>
 
 #if defined __NR_sched_getaffinity && defined __NR_sched_setaffinity \
@@ -41,8 +42,11 @@ setaffinity(unsigned long pid, unsigned long size, void *set)
 int
 main(void)
 {
+	PIDNS_TEST_INIT;
+
 	unsigned int cpuset_size = 1;
 	const pid_t pid = getpid();
+	const char *pid_str = pidns_pid2str(PT_TGID);
 
 	while (cpuset_size) {
 		assert(getaffinity(pid, cpuset_size, NULL) == -1);
@@ -50,18 +54,21 @@ main(void)
 			break;
 		if (EINVAL != errno)
 			perror_msg_and_skip("sched_getaffinity");
-		printf("sched_getaffinity(%d, %u, NULL) = %s\n",
-		       pid, cpuset_size, errstr);
+		pidns_print_leader();
+		printf("sched_getaffinity(%d%s, %u, NULL) = %s\n",
+		       pid, pid_str, cpuset_size, errstr);
 		cpuset_size <<= 1;
 	}
 	assert(cpuset_size);
-	printf("sched_getaffinity(%d, %u, NULL) = %s\n",
-	       pid, cpuset_size, errstr);
+	pidns_print_leader();
+	printf("sched_getaffinity(%d%s, %u, NULL) = %s\n",
+	       pid, pid_str, cpuset_size, errstr);
 
 	cpu_set_t *cpuset = tail_alloc(cpuset_size);
 	getaffinity(pid, cpuset_size, cpuset + 1);
-	printf("sched_getaffinity(%d, %u, %p) = %s\n",
-	       pid, cpuset_size, cpuset + 1, errstr);
+	pidns_print_leader();
+	printf("sched_getaffinity(%d%s, %u, %p) = %s\n",
+	       pid, pid_str, cpuset_size, cpuset + 1, errstr);
 
 	int ret_size = getaffinity(pid, cpuset_size, cpuset);
 	if (ret_size < 0)
@@ -69,7 +76,8 @@ main(void)
 				    pid, (unsigned) cpuset_size, cpuset, errstr);
 	assert(ret_size <= (int) cpuset_size);
 
-	printf("sched_getaffinity(%d, %u, [", pid, cpuset_size);
+	pidns_print_leader();
+	printf("sched_getaffinity(%d%s, %u, [", pid, pid_str, cpuset_size);
 	const char *sep;
 	unsigned int i, cpu;
 	for (i = 0, cpu = 0, sep = ""; i < (unsigned) ret_size * 8; ++i) {
@@ -85,8 +93,9 @@ main(void)
 	CPU_SET_S(cpu, cpuset_size, cpuset);
 	if (setaffinity(pid, cpuset_size, cpuset))
 		perror_msg_and_skip("sched_setaffinity");
-	printf("sched_setaffinity(%d, %u, [%u]) = 0\n",
-	       pid, cpuset_size, cpu);
+	pidns_print_leader();
+	printf("sched_setaffinity(%d%s, %u, [%u]) = 0\n",
+	       pid, pid_str, cpuset_size, cpu);
 
 	const unsigned int big_size = cpuset_size < 128 ? 128 : cpuset_size * 2;
 	cpuset = tail_alloc(big_size);
@@ -95,7 +104,8 @@ main(void)
 		perror_msg_and_fail("sched_getaffinity(%d, %u, %p) = %s\n",
 				    pid, big_size, cpuset, errstr);
 	assert(ret_size <= (int) big_size);
-	printf("sched_getaffinity(%d, %u, [", pid, big_size);
+	pidns_print_leader();
+	printf("sched_getaffinity(%d%s, %u, [", pid, pid_str, big_size);
 	for (i = 0, sep = ""; i < (unsigned) ret_size * 8; ++i) {
 		if (CPU_ISSET_S(i, (unsigned) ret_size, cpuset)) {
 			printf("%s%u", sep, i);
@@ -104,6 +114,7 @@ main(void)
 	}
 	printf("]) = %s\n", errstr);
 
+	pidns_print_leader();
 	puts("+++ exited with 0 +++");
 	return 0;
 }
diff --git a/tests/sched_xetattr--pidns-translation.c b/tests/sched_xetattr--pidns-translation.c
new file mode 100644
index 00000000..c152023d
--- /dev/null
+++ b/tests/sched_xetattr--pidns-translation.c
@@ -0,0 +1,2 @@
+#define PIDNS_TRANSLATION
+#include "sched_xetattr.c"
diff --git a/tests/sched_xetattr.c b/tests/sched_xetattr.c
index c63d7a80..4a76b2d6 100644
--- a/tests/sched_xetattr.c
+++ b/tests/sched_xetattr.c
@@ -15,6 +15,7 @@
 # include <stdio.h>
 # include <sched.h>
 # include <unistd.h>
+# include "pidns.h"
 # include "sched_attr.h"
 # include "xlat.h"
 # include "xlat/schedulers.h"
@@ -41,6 +42,8 @@ sys_sched_setattr(kernel_ulong_t pid, kernel_ulong_t attr, kernel_ulong_t flags)
 int
 main(void)
 {
+	PIDNS_TEST_INIT;
+
 	static const kernel_ulong_t bogus_pid =
 		(kernel_ulong_t) 0xdefacedfacefeedULL;
 	static const kernel_ulong_t bogus_size =
@@ -48,20 +51,28 @@ main(void)
 	static const kernel_ulong_t bogus_flags =
 		(kernel_ulong_t) 0xdefaceddeadc0deULL;
 
+	const int pid = getpid();
+	const char *pid_str = pidns_pid2str(PT_TGID);
+
 	TAIL_ALLOC_OBJECT_CONST_PTR(struct sched_attr, attr);
 	TAIL_ALLOC_OBJECT_CONST_PTR(unsigned int, psize);
 	void *const efault = attr + 1;
 
-	sys_sched_getattr(0, 0, 0, 0);
-	printf("sched_getattr(0, NULL, 0, 0) = %s\n", errstr);
+	sys_sched_getattr(pid, 0, 0, 0);
+	pidns_print_leader();
+	printf("sched_getattr(%d%s, NULL, 0, 0) = %s\n",
+		pid, pid_str, errstr);
 
 	sys_sched_getattr(0, (unsigned long) attr, 0, 0);
+	pidns_print_leader();
 	printf("sched_getattr(0, %p, 0, 0) = %s\n", attr, errstr);
 
 	sys_sched_getattr(bogus_pid, 0, 0, 0);
+	pidns_print_leader();
 	printf("sched_getattr(%d, NULL, 0, 0) = %s\n", (int) bogus_pid, errstr);
 
 	sys_sched_getattr(-1U, (unsigned long) attr, bogus_size, bogus_flags);
+	pidns_print_leader();
 	printf("sched_getattr(-1, %p, %s%u, %u) = %s\n",
 	       attr,
 # if defined __arm64__ || defined __aarch64__
@@ -72,11 +83,13 @@ main(void)
 	       (unsigned) bogus_size, (unsigned) bogus_flags, errstr);
 
 	sys_sched_getattr(0, (unsigned long) efault, SCHED_ATTR_MIN_SIZE, 0);
+	pidns_print_leader();
 	printf("sched_getattr(0, %p, %u, 0) = %s\n",
 	       efault, (unsigned) SCHED_ATTR_MIN_SIZE, errstr);
 
 	if (sys_sched_getattr(0, (unsigned long) attr, SCHED_ATTR_MIN_SIZE, 0))
 		perror_msg_and_skip("sched_getattr");
+	pidns_print_leader();
 	printf("sched_getattr(0, {size=%u, sched_policy=", attr->size);
 	printxval(schedulers, attr->sched_policy, NULL);
 	printf(", sched_flags=%s, sched_nice=%d, sched_priority=%u"
@@ -91,11 +104,13 @@ main(void)
 	       (unsigned) SCHED_ATTR_MIN_SIZE);
 
 	sys_sched_getattr(0, (unsigned long) efault, sizeof(*attr), 0);
+	pidns_print_leader();
 	printf("sched_getattr(0, %p, %u, 0) = %s\n",
 	       efault, (unsigned) sizeof(*attr), errstr);
 
 	if (sys_sched_getattr(0, (unsigned long) attr, sizeof(*attr), 0))
 		perror_msg_and_skip("sched_getattr");
+	pidns_print_leader();
 	printf("sched_getattr(0, {size=%u, sched_policy=", attr->size);
 	printxval(schedulers, attr->sched_policy, NULL);
 	printf(", sched_flags=%s, sched_nice=%d, sched_priority=%u"
@@ -121,11 +136,13 @@ main(void)
 			  F8ILL_KULONG_MASK | sizeof(*attr), F8ILL_KULONG_MASK);
 # if defined __arm64__ || defined __aarch64__
 	if (rc) {
+		pidns_print_leader();
 		printf("sched_getattr(0, %p, 0xffffffff<<32|%u, 0) = %s\n",
 		       attr, (unsigned) sizeof(*attr), errstr);
 	} else
 # endif
 	{
+		pidns_print_leader();
 		printf("sched_getattr(0, {size=%u, sched_policy=", attr->size);
 		printxval(schedulers, attr->sched_policy, NULL);
 		printf(", sched_flags=%s, sched_nice=%d, sched_priority=%u"
@@ -146,13 +163,16 @@ main(void)
 	}
 
 	sys_sched_setattr(bogus_pid, 0, 0);
+	pidns_print_leader();
 	printf("sched_setattr(%d, NULL, 0) = %s\n", (int) bogus_pid, errstr);
 
 	attr->sched_flags |= 1;
 
-	if (sys_sched_setattr(0, (unsigned long) attr, 0))
+	if (sys_sched_setattr(pid, (unsigned long) attr, 0))
 		perror_msg_and_skip("sched_setattr");
-	printf("sched_setattr(0, {size=%u, sched_policy=", attr->size);
+	pidns_print_leader();
+	printf("sched_setattr(%d%s, {size=%u, sched_policy=",
+		pid, pid_str, attr->size);
 	printxval(schedulers, attr->sched_policy, NULL);
 	printf(", sched_flags=%s, sched_nice=%d, sched_priority=%u"
 	       ", sched_runtime=%" PRIu64 ", sched_deadline=%" PRIu64
@@ -172,6 +192,7 @@ main(void)
 
 	sys_sched_setattr(F8ILL_KULONG_MASK, (unsigned long) attr,
 			  F8ILL_KULONG_MASK);
+	pidns_print_leader();
 	printf("sched_setattr(0, {size=%u, sched_policy=", attr->size);
 	printxval(schedulers, attr->sched_policy, NULL);
 	printf(", sched_flags=%s, sched_nice=%d, sched_priority=%u"
@@ -193,11 +214,13 @@ main(void)
 	*psize = attr->size;
 
 	sys_sched_setattr(0, (unsigned long) psize, 0);
+	pidns_print_leader();
 	printf("sched_setattr(0, %p, 0) = %s\n", psize, errstr);
 
 	attr->size = 0;
 
 	sys_sched_setattr(0, (unsigned long) attr, 0);
+	pidns_print_leader();
 	printf("sched_setattr(0, {size=%u, sched_policy=", attr->size);
 	printxval(schedulers, attr->sched_policy, NULL);
 	printf(", sched_flags=%s, sched_nice=%d, sched_priority=%u"
@@ -213,12 +236,14 @@ main(void)
 	attr->size = 1;
 
 	sys_sched_setattr(0, (unsigned long) attr, 0);
+	pidns_print_leader();
 	printf("sched_setattr(0, {size=%u} => {size=%u}, 0) = %s\n",
 	       1, attr->size, errstr);
 
 	attr->size = SCHED_ATTR_MIN_SIZE - 1;
 
 	sys_sched_setattr(0, (unsigned long) attr, 0);
+	pidns_print_leader();
 	printf("sched_setattr(0, {size=%u} => {size=%u}, 0) = %s\n",
 	       SCHED_ATTR_MIN_SIZE - 1, attr->size, errstr);
 
@@ -232,6 +257,7 @@ main(void)
 	attr->sched_period = 0xded1ca7edda7aca7ULL;
 
 	sys_sched_setattr(bogus_pid, (unsigned long) attr, bogus_flags);
+	pidns_print_leader();
 	printf("sched_setattr(%d, {size=%u, sched_policy=%#x /* SCHED_??? */, "
 	       "sched_flags=%#" PRIx64 " /* SCHED_FLAG_??? */, "
 	       "sched_nice=%d, sched_priority=%u, sched_runtime=%" PRIu64 ", "
@@ -274,6 +300,7 @@ main(void)
 	attr->sched_period = 0xded1ca7edda7aca7ULL;
 
 	sys_sched_setattr(bogus_pid, (unsigned long) attr, bogus_flags);
+	pidns_print_leader();
 	printf("sched_setattr(%d, {size=%u, sched_policy=%#x /* SCHED_??? */, "
 	       "sched_flags=SCHED_FLAG_RESET_ON_FORK|SCHED_FLAG_RECLAIM|"
 	       "SCHED_FLAG_DL_OVERRUN|0x80, "
@@ -296,11 +323,13 @@ main(void)
 		const kernel_ulong_t ill = f8ill_ptr_to_kulong(attr);
 
 		sys_sched_getattr(0, ill, sizeof(*attr), 0);
+		pidns_print_leader();
 		printf("sched_getattr(0, %#llx, %u, 0) = %s\n",
 		       (unsigned long long) ill, (unsigned) sizeof(*attr),
 		       errstr);
 
 		sys_sched_setattr(0, ill, 0);
+		pidns_print_leader();
 		printf("sched_setattr(0, %#llx, 0) = %s\n",
 		       (unsigned long long) ill, errstr);
 	}
@@ -310,6 +339,7 @@ main(void)
 	attr->sched_flags = 0x8fULL;
 
 	sys_sched_setattr(bogus_pid, (unsigned long) attr, bogus_flags);
+	pidns_print_leader();
 	printf("sched_setattr(%d, {size=%u, "
 	       "sched_flags=SCHED_FLAG_RESET_ON_FORK|SCHED_FLAG_RECLAIM|"
 	       "SCHED_FLAG_DL_OVERRUN|SCHED_FLAG_KEEP_POLICY|0x80, "
@@ -329,11 +359,13 @@ main(void)
 		const kernel_ulong_t ill = f8ill_ptr_to_kulong(attr);
 
 		sys_sched_getattr(0, ill, sizeof(*attr), 0);
+		pidns_print_leader();
 		printf("sched_getattr(0, %#llx, %u, 0) = %s\n",
 		       (unsigned long long) ill, (unsigned) sizeof(*attr),
 		       errstr);
 
 		sys_sched_setattr(0, ill, 0);
+		pidns_print_leader();
 		printf("sched_setattr(0, %#llx, 0) = %s\n",
 		       (unsigned long long) ill, errstr);
 	}
@@ -342,6 +374,7 @@ main(void)
 	attr->sched_flags = 0xe7ULL;
 
 	sys_sched_setattr(bogus_pid, (unsigned long) attr, bogus_flags);
+	pidns_print_leader();
 	printf("sched_setattr(%d, {size=%u, sched_policy=%#x /* SCHED_??? */, "
 	       "sched_flags=SCHED_FLAG_RESET_ON_FORK|SCHED_FLAG_RECLAIM|"
 	       "SCHED_FLAG_DL_OVERRUN|SCHED_FLAG_UTIL_CLAMP_MIN"
@@ -365,11 +398,13 @@ main(void)
 		const kernel_ulong_t ill = f8ill_ptr_to_kulong(attr);
 
 		sys_sched_getattr(0, ill, sizeof(*attr), 0);
+		pidns_print_leader();
 		printf("sched_getattr(0, %#llx, %u, 0) = %s\n",
 		       (unsigned long long) ill, (unsigned) sizeof(*attr),
 		       errstr);
 
 		sys_sched_setattr(0, ill, 0);
+		pidns_print_leader();
 		printf("sched_setattr(0, %#llx, 0) = %s\n",
 		       (unsigned long long) ill, errstr);
 	}
@@ -377,6 +412,7 @@ main(void)
 	attr->sched_flags = 0xcaffee90LL;
 
 	sys_sched_setattr(bogus_pid, (unsigned long) attr, bogus_flags);
+	pidns_print_leader();
 	printf("sched_setattr(%d, {size=%u, sched_flags=SCHED_FLAG_KEEP_PARAMS"
 	       "|0xcaffee80, sched_util_min=%u, sched_util_max=%u}, %u) = %s\n",
 	       (int) bogus_pid,
@@ -389,15 +425,18 @@ main(void)
 		const kernel_ulong_t ill = f8ill_ptr_to_kulong(attr);
 
 		sys_sched_getattr(0, ill, sizeof(*attr), 0);
+		pidns_print_leader();
 		printf("sched_getattr(0, %#llx, %u, 0) = %s\n",
 		       (unsigned long long) ill, (unsigned) sizeof(*attr),
 		       errstr);
 
 		sys_sched_setattr(0, ill, 0);
+		pidns_print_leader();
 		printf("sched_setattr(0, %#llx, 0) = %s\n",
 		       (unsigned long long) ill, errstr);
 	}
 
+	pidns_print_leader();
 	puts("+++ exited with 0 +++");
 	return 0;
 }
diff --git a/tests/sched_xetparam--pidns-translation.c b/tests/sched_xetparam--pidns-translation.c
new file mode 100644
index 00000000..9fb3e579
--- /dev/null
+++ b/tests/sched_xetparam--pidns-translation.c
@@ -0,0 +1,2 @@
+#define PIDNS_TRANSLATION
+#include "sched_xetparam.c"
diff --git a/tests/sched_xetparam.c b/tests/sched_xetparam.c
index de3915b2..aa9c68cc 100644
--- a/tests/sched_xetparam.c
+++ b/tests/sched_xetparam.c
@@ -7,6 +7,7 @@
 
 #include "tests.h"
 #include "scno.h"
+# include "pidns.h"
 
 #if defined __NR_sched_getparam && defined __NR_sched_setparam
 
@@ -17,18 +18,27 @@
 int
 main(void)
 {
+	PIDNS_TEST_INIT;
+
 	struct sched_param *const param =
 		tail_alloc(sizeof(struct sched_param));
 
-	long rc = syscall(__NR_sched_getparam, 0, param);
-	printf("sched_getparam(0, [%d]) = %ld\n",
-	       param->sched_priority, rc);
+	const int pid = getpid();
+	const char *pid_str = pidns_pid2str(PT_TGID);
+
+	long rc = syscall(__NR_sched_getparam, pid, param);
+	pidns_print_leader();
+	printf("sched_getparam(%d%s, [%d]) = %ld\n",
+	       pid, pid_str, param->sched_priority, rc);
 
 	param->sched_priority = -1;
-	rc = syscall(__NR_sched_setparam, 0, param);
-	printf("sched_setparam(0, [%d]) = %ld %s (%m)\n",
+	rc = syscall(__NR_sched_setparam, pid, param);
+	pidns_print_leader();
+	printf("sched_setparam(%d%s, [%d]) = %ld %s (%m)\n",
+	       pid, pid_str,
 	       param->sched_priority, rc, errno2name());
 
+	pidns_print_leader();
 	puts("+++ exited with 0 +++");
 	return 0;
 }
diff --git a/tests/sched_xetscheduler--pidns-translation.c b/tests/sched_xetscheduler--pidns-translation.c
new file mode 100644
index 00000000..78b794b2
--- /dev/null
+++ b/tests/sched_xetscheduler--pidns-translation.c
@@ -0,0 +1,2 @@
+#define PIDNS_TRANSLATION
+#include "sched_xetscheduler.c"
diff --git a/tests/sched_xetscheduler.c b/tests/sched_xetscheduler.c
index 047e8676..91b5e32d 100644
--- a/tests/sched_xetscheduler.c
+++ b/tests/sched_xetscheduler.c
@@ -7,6 +7,7 @@
 
 #include "tests.h"
 #include "scno.h"
+#include "pidns.h"
 
 #if defined __NR_sched_getscheduler && defined __NR_sched_setscheduler
 
@@ -17,8 +18,13 @@
 int
 main(void)
 {
+	PIDNS_TEST_INIT;
+
 	TAIL_ALLOC_OBJECT_CONST_PTR(struct sched_param, param);
-	long rc = syscall(__NR_sched_getscheduler, 0);
+	const int pid = getpid();
+	const char *pid_str = pidns_pid2str(PT_TGID);
+
+	long rc = syscall(__NR_sched_getscheduler, pid);
 	const char *scheduler;
 	switch (rc) {
 		case SCHED_FIFO:
@@ -50,33 +56,43 @@ main(void)
 		default:
 			scheduler = "SCHED_OTHER";
 	}
-	printf("sched_getscheduler(0) = %ld (%s)\n",
-	       rc, scheduler);
+	pidns_print_leader();
+	printf("sched_getscheduler(%d%s) = %ld (%s)\n",
+	       pid, pid_str, rc, scheduler);
 
 	rc = syscall(__NR_sched_getscheduler, -1);
+	pidns_print_leader();
 	printf("sched_getscheduler(-1) = %s\n", sprintrc(rc));
 
 	param->sched_priority = -1;
 
-	rc = syscall(__NR_sched_setscheduler, 0, SCHED_FIFO, NULL);
-	printf("sched_setscheduler(0, SCHED_FIFO, NULL) = %s\n", sprintrc(rc));
+	rc = syscall(__NR_sched_setscheduler, pid, SCHED_FIFO, NULL);
+	pidns_print_leader();
+	printf("sched_setscheduler(%d%s, SCHED_FIFO, NULL) = %s\n",
+	       pid, pid_str, sprintrc(rc));
 
-	rc = syscall(__NR_sched_setscheduler, 0, SCHED_FIFO, param + 1);
-	printf("sched_setscheduler(0, SCHED_FIFO, %p) = %s\n", param + 1,
-	       sprintrc(rc));
+	rc = syscall(__NR_sched_setscheduler, pid, SCHED_FIFO, param + 1);
+	pidns_print_leader();
+	printf("sched_setscheduler(%d%s, SCHED_FIFO, %p) = %s\n",
+	       pid, pid_str, param + 1, sprintrc(rc));
 
-	rc = syscall(__NR_sched_setscheduler, 0, 0xfaceda7a, param);
-	printf("sched_setscheduler(0, %#x /* SCHED_??? */, [%d]) = %s\n",
-	       0xfaceda7a, param->sched_priority, sprintrc(rc));
+	rc = syscall(__NR_sched_setscheduler, pid, 0xfaceda7a, param);
+	pidns_print_leader();
+	printf("sched_setscheduler(%d%s, %#x /* SCHED_??? */, [%d]) = %s\n",
+	       pid, pid_str, 0xfaceda7a,
+	       param->sched_priority, sprintrc(rc));
 
 	rc = syscall(__NR_sched_setscheduler, -1, SCHED_FIFO, param);
+	pidns_print_leader();
 	printf("sched_setscheduler(-1, SCHED_FIFO, [%d]) = %s\n",
 	       param->sched_priority, sprintrc(rc));
 
-	rc = syscall(__NR_sched_setscheduler, 0, SCHED_FIFO, param);
-	printf("sched_setscheduler(0, SCHED_FIFO, [%d]) = %s\n",
-	       param->sched_priority, sprintrc(rc));
+	rc = syscall(__NR_sched_setscheduler, pid, SCHED_FIFO, param);
+	pidns_print_leader();
+	printf("sched_setscheduler(%d%s, SCHED_FIFO, [%d]) = %s\n",
+	       pid, pid_str, param->sched_priority, sprintrc(rc));
 
+	pidns_print_leader();
 	puts("+++ exited with 0 +++");
 	return 0;
 }
diff --git a/tests/signal_receive--pidns-translation.c b/tests/signal_receive--pidns-translation.c
new file mode 100644
index 00000000..b4e3b2f8
--- /dev/null
+++ b/tests/signal_receive--pidns-translation.c
@@ -0,0 +1,2 @@
+#define PIDNS_TRANSLATION
+#include "signal_receive.c"
diff --git a/tests/signal_receive.c b/tests/signal_receive.c
index ad3b4ebd..70441a9e 100644
--- a/tests/signal_receive.c
+++ b/tests/signal_receive.c
@@ -8,6 +8,7 @@
  */
 
 #include "tests.h"
+#include "pidns.h"
 #include <signal.h>
 #include <stdio.h>
 #include <unistd.h>
@@ -26,10 +27,13 @@ handler(int sig, siginfo_t *info, void *ucontext)
 int
 main(void)
 {
+	PIDNS_TEST_INIT;
+
 	static const char prefix[] = "KERNEL BUG";
 	int printed = 0;
 
 	const int pid = getpid();
+	const char *pid_str = pidns_pid2str(PT_TGID);
 	const int uid = geteuid();
 
 	for (int sig = 1; sig <= 31; ++sig) {
@@ -73,10 +77,13 @@ main(void)
 		const int e_pid = s_pid;
 		const int e_uid = s_uid;
 #endif
-		printf("kill(%d, %s) = 0\n", pid, signal2name(sig));
-		printf("--- %s {si_signo=%s, si_code=SI_USER, si_pid=%d"
+		pidns_print_leader();
+		printf("kill(%d%s, %s) = 0\n", pid, pid_str, signal2name(sig));
+		pidns_print_leader();
+		printf("--- %s {si_signo=%s, si_code=SI_USER, si_pid=%d%s"
 		       ", si_uid=%d} ---\n",
-		       signal2name(sig), signal2name(e_sig), e_pid, e_uid);
+		       signal2name(sig), signal2name(e_sig),
+		       e_pid, pid_str, e_uid);
 
 		if (s_code || sig != s_sig || pid != s_pid || uid != s_uid) {
 			/*
@@ -91,11 +98,11 @@ main(void)
 			}
 			fprintf(stderr,
 				"%s: expected: si_signo=%d, si_code=%d"
-				", si_pid=%d, si_uid=%d\n"
+				", si_pid=%d%s, si_uid=%d\n"
 				"%s: received: si_signo=%d, si_code=%d"
-				", si_pid=%d, si_uid=%d\n",
-				prefix, sig, SI_USER, pid, uid,
-				prefix, sig, s_code, s_pid, s_uid);
+				", si_pid=%d%s, si_uid=%d\n",
+				prefix, sig, SI_USER, pid, pid_str, uid,
+				prefix, sig, s_code, s_pid, pid_str, s_uid);
 		}
 	}
 
@@ -104,6 +111,7 @@ main(void)
 			"*** PLEASE FIX THE KERNEL ***\n", prefix);
 	}
 
+	pidns_print_leader();
 	puts("+++ exited with 0 +++");
 	return 0;
 }
diff --git a/tests/so_peercred--pidns-translation.c b/tests/so_peercred--pidns-translation.c
new file mode 100644
index 00000000..402bbcfe
--- /dev/null
+++ b/tests/so_peercred--pidns-translation.c
@@ -0,0 +1,2 @@
+#define PIDNS_TRANSLATION
+#include "so_peercred.c"
diff --git a/tests/so_peercred.c b/tests/so_peercred.c
index 151bb175..20188bdb 100644
--- a/tests/so_peercred.c
+++ b/tests/so_peercred.c
@@ -9,6 +9,7 @@
  */
 
 #include "tests.h"
+#include "pidns.h"
 
 #include <stddef.h>
 #include <stdio.h>
@@ -53,6 +54,8 @@ so_str(void)
 int
 main(void)
 {
+	PIDNS_TEST_INIT;
+
 	TAIL_ALLOC_OBJECT_CONST_PTR(struct ucred, peercred);
 	TAIL_ALLOC_OBJECT_CONST_PTR(socklen_t, len);
 
@@ -75,6 +78,8 @@ main(void)
 	struct ucred *const gid_truncated =
 		tail_alloc(sizeof_gid_truncated);
 
+	const char *pid_str = pidns_pid2str(PT_TGID);
+
 	int sv[2];
 	if (socketpair(AF_UNIX, SOCK_STREAM, 0, sv))
                 perror_msg_and_skip("socketpair AF_UNIX SOCK_STREAM");
@@ -82,8 +87,10 @@ main(void)
 	/* classic getsockopt */
 	*len = sizeof(*peercred);
 	get_peercred(sv[0], peercred, len);
+	pidns_print_leader();
 	printf("getsockopt(%d, %s", sv[0], so_str());
 	PRINT_FIELD_D(", {", *peercred, pid);
+	printf("%s", pid_str);
 	PRINT_FIELD_UID(", ", *peercred, uid);
 	PRINT_FIELD_UID(", ", *peercred, gid);
 	printf("}, [%d]) = %s\n", *len, errstr);
@@ -91,14 +98,17 @@ main(void)
 	/* getsockopt with zero optlen */
 	*len = 0;
 	get_peercred(sv[0], peercred, len);
+	pidns_print_leader();
 	printf("getsockopt(%d, %s, %p, [0]) = %s\n",
 	       sv[0], so_str(), peercred, errstr);
 
 	/* getsockopt with optlen larger than necessary - shortened */
 	*len = sizeof(*peercred) + 1;
 	get_peercred(sv[0], peercred, len);
+	pidns_print_leader();
 	printf("getsockopt(%d, %s", sv[0], so_str());
 	PRINT_FIELD_D(", {", *peercred, pid);
+	printf("%s", pid_str);
 	PRINT_FIELD_UID(", ", *peercred, uid);
 	PRINT_FIELD_UID(", ", *peercred, gid);
 	printf("}, [%u->%d]) = %s\n",
@@ -110,6 +120,7 @@ main(void)
 	 */
 	*len = sizeof_pid_truncated;
 	get_peercred(sv[0], pid_truncated, len);
+	pidns_print_leader();
 	printf("getsockopt(%d, %s, {pid=", sv[0], so_str());
 	print_quoted_hex(pid_truncated, *len);
 	printf("}, [%d]) = %s\n", *len, errstr);
@@ -120,8 +131,10 @@ main(void)
 	 */
 	*len = sizeof_pid;
 	get_peercred(sv[0], pid, len);
+	pidns_print_leader();
 	printf("getsockopt(%d, %s", sv[0], so_str());
 	PRINT_FIELD_D(", {", *pid, pid);
+	printf("%s", pid_str);
 	printf("}, [%d]) = %s\n", *len, errstr);
 
 	/*
@@ -136,8 +149,10 @@ main(void)
 	 * to struct ucred.pid field.
 	 */
 	memcpy(uid, uid_truncated, sizeof_uid_truncated);
+	pidns_print_leader();
 	printf("getsockopt(%d, %s", sv[0], so_str());
 	PRINT_FIELD_D(", {", *uid, pid);
+	printf("%s", pid_str);
 	printf(", uid=");
 	print_quoted_hex(&uid->uid, sizeof_uid_truncated -
 				    offsetof(struct ucred, uid));
@@ -149,8 +164,10 @@ main(void)
 	 */
 	*len = sizeof_uid;
 	get_peercred(sv[0], uid, len);
+	pidns_print_leader();
 	printf("getsockopt(%d, %s", sv[0], so_str());
 	PRINT_FIELD_D(", {", *uid, pid);
+	printf("%s", pid_str);
 	PRINT_FIELD_UID(", ", *uid, uid);
 	printf("}, [%d]) = %s\n", *len, errstr);
 
@@ -166,8 +183,10 @@ main(void)
 	 * to struct ucred.pid and struct ucred.uid fields.
 	 */
 	memcpy(peercred, gid_truncated, sizeof_gid_truncated);
+	pidns_print_leader();
 	printf("getsockopt(%d, %s", sv[0], so_str());
 	PRINT_FIELD_D(", {", *peercred, pid);
+	printf("%s", pid_str);
 	PRINT_FIELD_UID(", ", *peercred, uid);
 	printf(", gid=");
 	print_quoted_hex(&peercred->gid, sizeof_gid_truncated -
@@ -177,14 +196,17 @@ main(void)
 	/* getsockopt optval EFAULT */
 	*len = sizeof(*peercred);
 	get_peercred(sv[0], &peercred->uid, len);
+	pidns_print_leader();
 	printf("getsockopt(%d, %s, %p, [%d]) = %s\n",
 	       sv[0], so_str(), &peercred->uid, *len, errstr);
 
 	/* getsockopt optlen EFAULT */
 	get_peercred(sv[0], peercred, len + 1);
+	pidns_print_leader();
 	printf("getsockopt(%d, %s, %p, %p) = %s\n",
 	       sv[0], so_str(), peercred, len + 1, errstr);
 
+	pidns_print_leader();
 	puts("+++ exited with 0 +++");
 	return 0;
 }
diff --git a/tests/xet_robust_list--pidns-translation.c b/tests/xet_robust_list--pidns-translation.c
new file mode 100644
index 00000000..e0477267
--- /dev/null
+++ b/tests/xet_robust_list--pidns-translation.c
@@ -0,0 +1,2 @@
+#define PIDNS_TRANSLATION
+#include "xet_robust_list.c"
diff --git a/tests/xet_robust_list.c b/tests/xet_robust_list.c
index 43239c8b..b5751b0a 100644
--- a/tests/xet_robust_list.c
+++ b/tests/xet_robust_list.c
@@ -8,6 +8,7 @@
 
 #include "tests.h"
 #include "scno.h"
+#include "pidns.h"
 
 #if defined __NR_get_robust_list && defined __NR_set_robust_list
 
@@ -30,27 +31,36 @@ sprintaddr(void *addr)
 int
 main(void)
 {
+	PIDNS_TEST_INIT;
+
 	const pid_t pid = getpid();
+	const char *pid_str = pidns_pid2str(PT_TGID);
 	const long long_pid = (unsigned long) (0xdeadbeef00000000LL | pid);
 	TAIL_ALLOC_OBJECT_CONST_PTR(void *, p_head);
 	TAIL_ALLOC_OBJECT_CONST_PTR(size_t, p_len);
 
 	if (syscall(__NR_get_robust_list, long_pid, p_head, p_len))
 		perror_msg_and_skip("get_robust_list");
-	printf("get_robust_list(%d, [%s], [%lu]) = 0\n",
-	       (int) pid, sprintaddr(*p_head), (unsigned long) *p_len);
+	pidns_print_leader();
+	printf("get_robust_list(%d%s, [%s], [%lu]) = 0\n",
+	       pid, pid_str, sprintaddr(*p_head),
+	       (unsigned long) *p_len);
 
 	void *head = tail_alloc(*p_len);
 	if (syscall(__NR_set_robust_list, head, *p_len))
 		perror_msg_and_skip("set_robust_list");
+	pidns_print_leader();
 	printf("set_robust_list(%p, %lu) = 0\n",
 	       head, (unsigned long) *p_len);
 
 	if (syscall(__NR_get_robust_list, long_pid, p_head, p_len))
 		perror_msg_and_skip("get_robust_list");
-	printf("get_robust_list(%d, [%s], [%lu]) = 0\n",
-	       (int) pid, sprintaddr(*p_head), (unsigned long) *p_len);
+	pidns_print_leader();
+	printf("get_robust_list(%d%s, [%s], [%lu]) = 0\n",
+	       pid, pid_str, sprintaddr(*p_head),
+	       (unsigned long) *p_len);
 
+	pidns_print_leader();
 	puts("+++ exited with 0 +++");
 	return 0;
 }
diff --git a/tests/xetpgid--pidns-translation.c b/tests/xetpgid--pidns-translation.c
new file mode 100644
index 00000000..b6469628
--- /dev/null
+++ b/tests/xetpgid--pidns-translation.c
@@ -0,0 +1,2 @@
+#define PIDNS_TRANSLATION
+#include "xetpgid.c"
diff --git a/tests/xetpgid.c b/tests/xetpgid.c
index 9b070af2..411edfc7 100644
--- a/tests/xetpgid.c
+++ b/tests/xetpgid.c
@@ -10,6 +10,7 @@
 
 #include "tests.h"
 #include "scno.h"
+#include "pidns.h"
 
 #if defined __NR_getpgid && defined __NR_setpgid
 
@@ -19,13 +20,21 @@
 int
 main(void)
 {
-	const int pid = getpid();
-	long rc = syscall(__NR_getpgid, F8ILL_KULONG_MASK | pid);
-	printf("getpgid(%d) = %ld\n", pid, rc);
-
-	rc = syscall(__NR_setpgid, F8ILL_KULONG_MASK, F8ILL_KULONG_MASK | pid);
-	printf("setpgid(0, %d) = %ld\n", pid, rc);
+	PIDNS_TEST_INIT;
 
+	const int pid = getpid();
+	long pgid = syscall(__NR_getpgid, F8ILL_KULONG_MASK | pid);
+	pidns_print_leader();
+	printf("getpgid(%d%s) = %ld%s\n", pid, pidns_pid2str(PT_TGID),
+		pgid, pidns_pid2str(PT_PGID));
+
+	long rc = syscall(__NR_setpgid, F8ILL_KULONG_MASK,
+		F8ILL_KULONG_MASK | pgid);
+	pidns_print_leader();
+	printf("setpgid(0, %ld%s) = %s\n", pgid, pidns_pid2str(PT_PGID),
+		sprintrc(rc));
+
+	pidns_print_leader();
 	puts("+++ exited with 0 +++");
 	return 0;
 }
diff --git a/tests/xetpriority--pidns-translation.c b/tests/xetpriority--pidns-translation.c
new file mode 100644
index 00000000..c93669cb
--- /dev/null
+++ b/tests/xetpriority--pidns-translation.c
@@ -0,0 +1,2 @@
+#define PIDNS_TRANSLATION
+#include "xetpriority.c"
diff --git a/tests/xetpriority.c b/tests/xetpriority.c
index 2d61bd10..dd38217d 100644
--- a/tests/xetpriority.c
+++ b/tests/xetpriority.c
@@ -7,6 +7,7 @@
 
 #include "tests.h"
 #include "scno.h"
+#include "pidns.h"
 
 #if defined __NR_getpriority && defined __NR_setpriority
 
@@ -17,15 +18,30 @@
 int
 main(void)
 {
+	PIDNS_TEST_INIT;
+
 	const int pid = getpid();
+	const int pgid = getpgid(0);
+
 	long rc = syscall(__NR_getpriority, PRIO_PROCESS,
 			  F8ILL_KULONG_MASK | pid);
-	printf("getpriority(PRIO_PROCESS, %d) = %ld\n", pid, rc);
+	pidns_print_leader();
+	printf("getpriority(PRIO_PROCESS, %d%s) = %ld\n",
+		pid, pidns_pid2str(PT_TGID), rc);
 
 	rc = syscall(__NR_setpriority, PRIO_PROCESS,
 		     F8ILL_KULONG_MASK | pid, F8ILL_KULONG_MASK);
-	printf("setpriority(PRIO_PROCESS, %d, 0) = %s\n", pid, sprintrc(rc));
+	pidns_print_leader();
+	printf("setpriority(PRIO_PROCESS, %d%s, 0) = %s\n",
+		pid, pidns_pid2str(PT_TGID), sprintrc(rc));
+
+	rc = syscall(__NR_getpriority, PRIO_PGRP,
+			  F8ILL_KULONG_MASK | pgid);
+	pidns_print_leader();
+	printf("getpriority(PRIO_PGRP, %d%s) = %ld\n",
+		pgid, pidns_pid2str(PT_PGID), rc);
 
+	pidns_print_leader();
 	puts("+++ exited with 0 +++");
 	return 0;
 }
-- 
2.27.0


From ldv at altlinux.org  Sat Aug  8 22:07:56 2020
From: ldv at altlinux.org (Dmitry V. Levin)
Date: Sun, 9 Aug 2020 01:07:56 +0300
Subject: [PATCH v7 1/5] PID namespace translation support
In-Reply-To: <20200808211437.469898-2-uzonyi.akos@gmail.com>
References: <20200808211437.469898-1-uzonyi.akos@gmail.com>
 <20200808211437.469898-2-uzonyi.akos@gmail.com>
Message-ID: <20200808220756.GA23517@altlinux.org>

On Sat, Aug 08, 2020 at 11:14:33PM +0200, ?kos Uzonyi wrote:
[...]
> --- a/NEWS
> +++ b/NEWS
> @@ -22,6 +22,7 @@ Noteworthy changes in release 5.8 (2020-08-06)
>      KEYCTL_*, KVM_*, LOOP_*, NDA_*, RTC_*, TCA_*, STATX_*, and *_MAGIC
>      constants.
>    * Updated lists of ioctl commands from Linux 5.8.
> +  * Added --pidns-translation option for PID namespace translation.
>  
>  * Bug fixes
>    * Added statx syscall to %fstat trace class.

This went to the old section of the NEWS.

> --- a/defs.h
> +++ b/defs.h
> @@ -983,6 +1005,28 @@ print_local_array_ex(struct tcb *tcp,
>  extern kernel_ulong_t *
>  fetch_indirect_syscall_args(struct tcb *, kernel_ulong_t addr, unsigned int n_args);
>  
> +extern void pidns_init(void);
> +
> +/**
> + * Returns the pid of the tracee as present in /proc of the tracer (can be
> + * different from tcp->pid if /proc and the tracee process are in different PID
> + * namespaces).
> + */
> +extern int get_proc_pid(struct tcb *);

I though it can be different only if /proc and the _tracer_
are in different PID namespaces.

> +
> +/**
> + * Translates a pid from tracee's namespace to our namepace.
> + *
> + * @param tcp             The tcb of the tracee
> + *                        (NULL: from_id is in strace's namespace. Useful for
> + *                         getting the proc PID of from_id)
> + * @param from_id         The id to be translated
> + * @param type            The PID type of from_id
> + * @param proc_pid_ptr    If not NULL, writes the proc PID to this location
> + */
> +extern int translate_pid(struct tcb *, int dest_id, enum pid_type type,
> +		    int *proc_pid_ptr);

Sometimes this function returns the translated pid, sometimes it doesn't.
Could you document the return value, please?

Also, could you check whether all users of this function do proper error
handling, please?  I'm afraid sometimes they just go on with 0 instead of
translated pid.

> @@ -1058,6 +1102,15 @@ printfd(struct tcb *tcp, int fd)
>   * of the tracee the descriptor tcp).  This is a stub.
>   */
>  extern void printfd_pid_tracee_ns(struct tcb *tcp, pid_t pid, int fd);
> +
> +/** Prints a PID in the tracee's PID namespace */
> +extern void printpid(struct tcb *, int pid, enum pid_type type);

This is slightly ambiguous.  One might think it translates a pid into the
tracee's PID namespace and prints it, which is certainly not the case.

I think this function prints a pid which is specified in the tracee's PID namespace.

[...]
> +int
> +translate_pid(struct tcb *tcp, int from_id, enum pid_type type,
> +              int *proc_pid_ptr)
> +{
> +	if (from_id <= 0 || type < 0 || type >= PT_COUNT)
> +		return 0;
> +
> +	/* If translation is trivial */
> +	if ((!tcp || get_ns(tcp) == get_our_ns()) &&
> +	    (is_proc_ours() || !proc_pid_ptr)) {

I suggest checking for !proc_pid_ptr first because its very cheap.


-- 
ldv

From uzonyi.akos at gmail.com  Sun Aug  9 14:13:01 2020
From: uzonyi.akos at gmail.com (=?UTF-8?q?=C3=81kos=20Uzonyi?=)
Date: Sun,  9 Aug 2020 16:13:01 +0200
Subject: [PATCH v8 0/5] [PIDNS] Final
Message-ID: <20200809141306.477539-1-uzonyi.akos@gmail.com>

From: Uzonyi ?kos <uzonyi.akos at gmail.com>

Changes in v8:
  - translate_pid: document return value; check !proc_pid first
  - NEWS: move to new section
  - get_proc_pid, printpid: fix comment
  - Check if translation failed
Changes in v7:
  - Run uniq on gettid--pidns-translation test output
  - Add comment to printpid
  - translate_id: do not call get_our_ns if not necessary
  - Remove unnecessary parentheses
  - Fix commit message of last commit (s/-Y/--pidns-translation/)
  - get_proc_pid: remove unnecessary optimization
  - trie.c: remove #include <assert.h>
  - Add clarification to get_proc_pid's comment
  - Fix typos
  - trie.c: ptr_sz_lg use void* in sizeof
  - trie_get_node_size: fix comment
  - trie.c: remove "TODO: overflow"
  - ipc_shmctl.c: remove duplicate #include "print_field.h"
Changes in v6:
  - Add function with documentation for creating tries
  - Do not use -1ULL as error indicator in tcb.pid_ns
  - Use unsigned int (instead of uint64_t) for NS IDs
  - Add constant for NS ID size.
  - Modify get_proc_pid a bit
  - Die if trie creation fails
Changes in v5:
  - Squash "Use printpid in *" commits
  - Makefile.am: move adding getpid.c to "Use printpid in decoders"
  - Remove pid_ns_inited field from struct tcb
  - strace.1.in: remove -Y flag
  - Use tprints instead of tprintf where possible
  - Make some global variables static
  - pidns_init: remove "inited" bool variable
  - Make printpid_translation static
  - tests/pidns.c: refactor a bit
  - check_ns_ioctl: fix error msg
  - defs.h: Move adding get_proc_pid to "PID namespace translation support"
  - Remove tcp paramter name from declarations
  - Update printfd_pid_tracee_ns documentation
  - Use named constants for trie_create arguments
  - Add documentation comments
  - Add printpid_tgid_pgid function
  - Delete get_pid_max function; use global variables instead
  - Refactor trie:
    - Move key_size argument
    - Remove support for TRIE_SET
    - Merge trie_create, trie_init, trie_check functions
    - trie_free_node: make static, fix "node" argument type
    - Add max_depth field
    - Reorder functions
    - Extract common parts of trie_get, trie_set
Changes in v4:
  - Skip tests if NS_* ioctl commands are not supported
  - Improve documentation in pidns.h
  - Use pipe for init process termination (instead of SIGKILL)
  - Add PIDNS_TEST_INIT macro
  - Remove "ifdef __NR_gettid"
  - Fix fork--pidns-tranlsation.test: skip if unshare fails with EPERM
  - Use debug message instead of normal message in some cases
  - Rename some labels
  - Rewrite get_ns function
  - Remove O_NONBLOCK from open(/proc/<pid>/ns/pid)
Changes in v3:
  - Split accidentally sqashed last commit
  - Undo modification of tests/pidfd_send_signal.c
  - Rename kcmp-yY test to kcmp-y--pidns-translation
  - Skip tests if unshare fails with EPERM
  - Fix buffer size in pidns_pid2str
  - Use largefile_wrappers.h macros
  - Return early if from_ns or our_ns is 0
  - Do not call ioctl(NS_GET_PARENT) again, if first failed with ENOTTY
  - Skip pidns tests if Linux kernel version < 4.9
  - Use smaller trie nodes in pidns.c
  - Remove race condition from fork--pidns-translation test
  - Move "key_size" to center in trie description
  - Use PT_TID (not PT_TGID) when translating tcp->pid
  - Fix get_ns_hierarchy and get_id_list functions
  - Fix migrate_pages test if syscall succeds
  - Fix filtering in ioctl_block--pidns-translation.test
  - Fix -a flag value in xetpriority test
Changes in v2:
  - Add missing header files to Makefile
  - Fix pointer-to-int-cast errors
  - Fix unused-result errors
  - Use perror_msg instead of perror_func_msg where appropriate
  - Remove tcb parameter of read_int_from_file
  - Use xsprintf instead of snprintf
  - Refactor get_pid_max, get_ns_hierarchy, get_id_list functions
  - Remove -Y flag
  - Improve documentation of trie
  - Fix printing of f_owner_ex struct
  - Use printpid for F_GETOWN, F_SETOWN fcntl command arguments
  - Use printpid for shmid_ds.shm_cpid, shmid_ds.shm_clid
  - Call pidns_init before parsing arguments

?kos Uzonyi (5):
  PID namespace translation support
  Use printpid in decoders
  Use get_proc_pid for /proc paths
  Implement testing framework for pidns
  Add tests for PID namespace translation

 Makefile.am                                   |   4 +
 NEWS                                          |   1 +
 affinity.c                                    |   6 +-
 block.c                                       |   2 +-
 bpf.c                                         |   2 +-
 capability.c                                  |   4 +-
 clone.c                                       |  14 +-
 defs.h                                        |  61 +-
 fcntl.c                                       |  24 +-
 get_robust_list.c                             |   3 +-
 getpid.c                                      |  46 ++
 ioprio.c                                      |  26 +-
 ipc_shmctl.c                                  |   4 +-
 kcmp.c                                        |   5 +-
 largefile_wrappers.h                          |   2 +
 linux/dummy.h                                 |   8 +-
 mmap_cache.c                                  |   2 +-
 msghdr.c                                      |   2 +-
 net.c                                         |   2 +-
 netlink.c                                     |   5 +-
 numa.c                                        |   6 +-
 pathtrace.c                                   |   7 +-
 pidfd_open.c                                  |   2 +-
 pidns.c                                       | 604 ++++++++++++++++++
 print_fields.h                                |  24 +
 printsiginfo.c                                |   2 +-
 process.c                                     |   3 +-
 process_vm.c                                  |   6 +-
 resource.c                                    |  27 +-
 sched.c                                       |  25 +-
 signal.c                                      |  21 +-
 sockaddr.c                                    |   2 +-
 strace.1.in                                   |   4 +
 strace.c                                      |  11 +-
 syscall.c                                     |  15 +
 tests/.gitignore                              |  31 +
 tests/Makefile.am                             |  38 ++
 tests/fcntl--pidns-translation.c              |   2 +
 tests/fcntl-common.c                          |  82 ++-
 tests/fcntl.c                                 |   1 +
 tests/fcntl64--pidns-translation.c            |   2 +
 tests/fcntl64.c                               |   3 +
 tests/fork--pidns-translation.awk             |  15 +
 tests/fork--pidns-translation.c               |  69 ++
 tests/fork--pidns-translation.test            |  16 +
 tests/gen_tests.in                            |  29 +-
 tests/getpgrp--pidns-translation.c            |   2 +
 tests/getpgrp.c                               |   8 +-
 tests/getpid--pidns-translation.c             |   2 +
 tests/getpid.c                                |   8 +-
 tests/getsid--pidns-translation.c             |   2 +
 tests/getsid.c                                |   9 +-
 tests/gettid--pidns-translation.c             |   2 +
 tests/gettid--pidns-translation.test          |  20 +
 tests/gettid.c                                |   8 +-
 tests/init.sh                                 |  31 +
 tests/ioctl_block--pidns-translation.c        |   2 +
 tests/ioctl_block--pidns-translation.test     |  24 +
 tests/ioctl_block.c                           |  24 +-
 tests/ioprio--pidns-translation.c             |   2 +
 tests/ioprio.c                                |  54 +-
 tests/kcmp-y--pidns-translation.c             |   2 +
 tests/kcmp.c                                  |  36 +-
 tests/kill--pidns-translation.c               |   2 +
 tests/kill.c                                  |  12 +-
 tests/migrate_pages--pidns-translation.c      |   2 +
 tests/migrate_pages.c                         |  17 +-
 tests/move_pages--pidns-translation.c         |   2 +
 tests/move_pages.c                            |  51 +-
 tests/net-sockaddr--pidns-translation.c       |   2 +
 tests/net-sockaddr.c                          |  66 +-
 tests/netlink_audit--pidns-translation.c      |   2 +
 tests/netlink_audit--pidns-translation.test   |  13 +
 tests/netlink_audit.c                         |  11 +-
 tests/pidfd_open--pidns-translation.c         |   2 +
 tests/pidfd_open.c                            |  21 +-
 tests/pidfd_send_signal--pidns-translation.c  |   2 +
 tests/pidfd_send_signal.c                     |  13 +-
 tests/pidns.c                                 | 214 +++++++
 tests/pidns.h                                 |  56 ++
 tests/prlimit64--pidns-translation.c          |   2 +
 tests/prlimit64.c                             |  17 +-
 tests/process_vm_readv--pidns-translation.c   |   2 +
 tests/process_vm_readv_writev.c               |  27 +-
 tests/process_vm_writev--pidns-translation.c  |   2 +
 tests/rt_sigqueueinfo--pidns-translation.c    |   2 +
 tests/rt_sigqueueinfo.c                       |  15 +-
 tests/rt_tgsigqueueinfo--pidns-translation.c  |   2 +
 tests/rt_tgsigqueueinfo.c                     |  26 +-
 tests/sched_xetaffinity--pidns-translation.c  |   2 +
 tests/sched_xetaffinity.c                     |  31 +-
 tests/sched_xetattr--pidns-translation.c      |   2 +
 tests/sched_xetattr.c                         |  47 +-
 tests/sched_xetparam--pidns-translation.c     |   2 +
 tests/sched_xetparam.c                        |  20 +-
 tests/sched_xetscheduler--pidns-translation.c |   2 +
 tests/sched_xetscheduler.c                    |  44 +-
 tests/signal_receive--pidns-translation.c     |   2 +
 tests/signal_receive.c                        |  22 +-
 tests/so_peercred--pidns-translation.c        |   2 +
 tests/so_peercred.c                           |  22 +
 tests/xet_robust_list--pidns-translation.c    |   2 +
 tests/xet_robust_list.c                       |  18 +-
 tests/xetpgid--pidns-translation.c            |   2 +
 tests/xetpgid.c                               |  21 +-
 tests/xetpriority--pidns-translation.c        |   2 +
 tests/xetpriority.c                           |  20 +-
 trie.c                                        | 248 +++++++
 trie.h                                        |  89 +++
 util.c                                        |  31 +-
 wait.c                                        |  36 +-
 111 files changed, 2500 insertions(+), 256 deletions(-)
 create mode 100644 getpid.c
 create mode 100644 pidns.c
 create mode 100644 tests/fcntl--pidns-translation.c
 create mode 100644 tests/fcntl64--pidns-translation.c
 create mode 100644 tests/fork--pidns-translation.awk
 create mode 100644 tests/fork--pidns-translation.c
 create mode 100755 tests/fork--pidns-translation.test
 create mode 100644 tests/getpgrp--pidns-translation.c
 create mode 100644 tests/getpid--pidns-translation.c
 create mode 100644 tests/getsid--pidns-translation.c
 create mode 100644 tests/gettid--pidns-translation.c
 create mode 100755 tests/gettid--pidns-translation.test
 create mode 100644 tests/ioctl_block--pidns-translation.c
 create mode 100755 tests/ioctl_block--pidns-translation.test
 create mode 100644 tests/ioprio--pidns-translation.c
 create mode 100644 tests/kcmp-y--pidns-translation.c
 create mode 100644 tests/kill--pidns-translation.c
 create mode 100644 tests/migrate_pages--pidns-translation.c
 create mode 100644 tests/move_pages--pidns-translation.c
 create mode 100644 tests/net-sockaddr--pidns-translation.c
 create mode 100644 tests/netlink_audit--pidns-translation.c
 create mode 100755 tests/netlink_audit--pidns-translation.test
 create mode 100644 tests/pidfd_open--pidns-translation.c
 create mode 100644 tests/pidfd_send_signal--pidns-translation.c
 create mode 100644 tests/pidns.c
 create mode 100644 tests/pidns.h
 create mode 100644 tests/prlimit64--pidns-translation.c
 create mode 100644 tests/process_vm_readv--pidns-translation.c
 create mode 100644 tests/process_vm_writev--pidns-translation.c
 create mode 100644 tests/rt_sigqueueinfo--pidns-translation.c
 create mode 100644 tests/rt_tgsigqueueinfo--pidns-translation.c
 create mode 100644 tests/sched_xetaffinity--pidns-translation.c
 create mode 100644 tests/sched_xetattr--pidns-translation.c
 create mode 100644 tests/sched_xetparam--pidns-translation.c
 create mode 100644 tests/sched_xetscheduler--pidns-translation.c
 create mode 100644 tests/signal_receive--pidns-translation.c
 create mode 100644 tests/so_peercred--pidns-translation.c
 create mode 100644 tests/xet_robust_list--pidns-translation.c
 create mode 100644 tests/xetpgid--pidns-translation.c
 create mode 100644 tests/xetpriority--pidns-translation.c
 create mode 100644 trie.c
 create mode 100644 trie.h

--
2.27.0


From uzonyi.akos at gmail.com  Sun Aug  9 14:13:02 2020
From: uzonyi.akos at gmail.com (=?UTF-8?q?=C3=81kos=20Uzonyi?=)
Date: Sun,  9 Aug 2020 16:13:02 +0200
Subject: [PATCH v8 1/5] PID namespace translation support
In-Reply-To: <20200809141306.477539-1-uzonyi.akos@gmail.com>
References: <20200809141306.477539-1-uzonyi.akos@gmail.com>
Message-ID: <20200809141306.477539-2-uzonyi.akos@gmail.com>

* defs.h (pidns_translation): New variable.
(tcb): Add pid_ns field.
(RVAL_MASK): Change value from 013 to 017.
(RVAL_TID, RVAL_SID, RVAL_TGID, RVAL_PGID): New definitions.
(pid_type): New enum.
(pidns_init, translate_pid, get_proc_pid, printpid, printpid_tgid_pgid):
New function declarations.
* largefile_wrappers.h (fstat_fd): New macro.
* pidns.c: New file.
* trie.c: New file.
* trie.h: New file.
* Makefile.am (libstrace_a_SOURCES): Add trie.c, trie.h, pidns.c.
* strace.c (pidns_translation): New variable.
(init): Add --pidns-translation option.
* syscall.c (syscall_exiting_trace): Handle RVAL_* return values.
* NEWS: Mention this.
* strace.1.in: Add description for new option.

Co-Authored-by: Eugene Syromyatnikov <evgsyr at gmail.com>
---
 Makefile.am          |   3 +
 NEWS                 |   1 +
 defs.h               |  56 +++-
 largefile_wrappers.h |   2 +
 pidns.c              | 604 +++++++++++++++++++++++++++++++++++++++++++
 strace.1.in          |   4 +
 strace.c             |   9 +
 syscall.c            |  15 ++
 trie.c               | 248 ++++++++++++++++++
 trie.h               |  89 +++++++
 10 files changed, 1030 insertions(+), 1 deletion(-)
 create mode 100644 pidns.c
 create mode 100644 trie.c
 create mode 100644 trie.h

diff --git a/Makefile.am b/Makefile.am
index f5447811..73c22035 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -233,6 +233,7 @@ libstrace_a_SOURCES =	\
 	personality.c	\
 	pidfd_getfd.c	\
 	pidfd_open.c	\
+	pidns.c		\
 	pkeys.c		\
 	poll.c		\
 	prctl.c		\
@@ -344,6 +345,8 @@ libstrace_a_SOURCES =	\
 	time.c		\
 	times.c		\
 	trace_event.h	\
+	trie.c 		\
+	trie.h 		\
 	truncate.c	\
 	ubi.c		\
 	ucopy.c		\
diff --git a/NEWS b/NEWS
index 10039ceb..c3c5c162 100644
--- a/NEWS
+++ b/NEWS
@@ -2,6 +2,7 @@ Noteworthy changes in release ?.? (????-??-??)
 ==============================================
 
 * Improvements
+  * Added --pidns-translation option for PID namespace translation.
 
 * Bug fixes
 
diff --git a/defs.h b/defs.h
index f7ac54f3..511a92a2 100644
--- a/defs.h
+++ b/defs.h
@@ -280,6 +280,13 @@ struct tcb {
 	struct timespec etime;	/* Syscall entry time (CLOCK_MONOTONIC) */
 	struct timespec delay_expiration_time; /* When does the delay end */
 
+	/*
+	 * The ID of the PID namespace of this process
+	 * (inode number of /proc/<pid>/ns/pid)
+	 * (0: not initialized)
+	 */
+	unsigned int pid_ns;
+
 	struct mmap_cache_t *mmap_cache;
 
 	/*
@@ -413,7 +420,11 @@ extern const struct xlat whence_codes[];
 # define RVAL_HEX	001	/* hex format */
 # define RVAL_OCTAL	002	/* octal format */
 # define RVAL_FD		010	/* file descriptor */
-# define RVAL_MASK	013	/* mask for these values */
+# define RVAL_TID	011	/* task ID */
+# define RVAL_SID	012	/* session ID */
+# define RVAL_TGID	013	/* thread group ID */
+# define RVAL_PGID	014	/* process group ID */
+# define RVAL_MASK	017	/* mask for these values */
 
 # define RVAL_STR	020	/* Print `auxstr' field after return val */
 # define RVAL_NONE	040	/* Print nothing */
@@ -428,6 +439,16 @@ extern const struct xlat whence_codes[];
 
 # define indirect_ipccall(tcp) (tcp_sysent(tcp)->sys_flags & TRACE_INDIRECT_SUBCALL)
 
+enum pid_type {
+	PT_TID,
+	PT_TGID,
+	PT_PGID,
+	PT_SID,
+
+	PT_COUNT,
+	PT_NONE = -1
+};
+
 enum sock_proto {
 	SOCK_PROTO_UNKNOWN,
 	SOCK_PROTO_UNIX,
@@ -469,6 +490,7 @@ extern int Tflag_scale;
 extern int Tflag_width;
 extern bool iflag;
 extern bool count_wallclock;
+extern unsigned int pidns_translation;
 /* are we filtering traces based on paths? */
 extern struct path_set {
 	const char **paths_selected;
@@ -983,6 +1005,29 @@ print_local_array_ex(struct tcb *tcp,
 extern kernel_ulong_t *
 fetch_indirect_syscall_args(struct tcb *, kernel_ulong_t addr, unsigned int n_args);
 
+extern void pidns_init(void);
+
+/**
+ * Returns the pid of the tracee as present in /proc of the tracer (can be
+ * different from tcp->pid if /proc and the tracer process are in different PID
+ * namespaces).
+ */
+extern int get_proc_pid(struct tcb *);
+
+/**
+ * Translates a pid from tracee's namespace to our namepace.
+ *
+ * @param tcp             The tcb of the tracee
+ *                        (NULL: from_id is in strace's namespace. Useful for
+ *                         getting the proc PID of from_id)
+ * @param from_id         The id to be translated
+ * @param type            The PID type of from_id
+ * @param proc_pid_ptr    If not NULL, writes the proc PID to this location
+ * @return                The translated id, or 0 if translation fails.
+ */
+extern int translate_pid(struct tcb *, int dest_id, enum pid_type type,
+		    int *proc_pid_ptr);
+
 extern void
 dumpiov_in_msghdr(struct tcb *, kernel_ulong_t addr, kernel_ulong_t data_size);
 
@@ -1058,6 +1103,15 @@ printfd(struct tcb *tcp, int fd)
  * of the tracee the descriptor tcp).  This is a stub.
  */
 extern void printfd_pid_tracee_ns(struct tcb *tcp, pid_t pid, int fd);
+
+/** Prints a PID specified in the tracee's PID namespace */
+extern void printpid(struct tcb *, int pid, enum pid_type type);
+
+/**
+ * Prints pid as a TGID if positive, and PGID if negative
+ * (like the first argument of kill).
+ */
+extern void printpid_tgid_pgid(struct tcb *, int pid);
 extern void print_sockaddr(struct tcb *, const void *sa, int len);
 extern bool
 print_inet_addr(int af, const void *addr, unsigned int len, const char *var_name);
diff --git a/largefile_wrappers.h b/largefile_wrappers.h
index 116e7048..9d8f5c92 100644
--- a/largefile_wrappers.h
+++ b/largefile_wrappers.h
@@ -29,6 +29,7 @@
 #  else
 #   define fcntl_fd fcntl
 #  endif
+#  define fstat_fd fstat64
 #  define strace_stat_t struct stat64
 #  define stat_file stat64
 #  define struct_dirent struct dirent64
@@ -39,6 +40,7 @@
 #  define open_file open
 #  define fopen_stream fopen
 #  define fcntl_fd fcntl
+#  define fstat_fd fstat
 #  define strace_stat_t struct stat
 #  define stat_file stat
 #  define struct_dirent struct dirent
diff --git a/pidns.c b/pidns.c
new file mode 100644
index 00000000..edab73f8
--- /dev/null
+++ b/pidns.c
@@ -0,0 +1,604 @@
+/*
+ * Copyright (c) 2020 ?kos Uzonyi <uzonyi.akos at gmail.com>
+ * All rights reserved.
+ *
+ * SPDX-License-Identifier: LGPL-2.1-or-later
+ */
+
+#include "defs.h"
+
+
+#include <dirent.h>
+#include <fcntl.h>
+#include <stdint.h>
+#include <string.h>
+#include <unistd.h>
+
+#include <asm/unistd.h>
+
+#include <sys/ioctl.h>
+#include <sys/param.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+
+#include "largefile_wrappers.h"
+#include "trie.h"
+#include "nsfs.h"
+#include "xmalloc.h"
+#include "xstring.h"
+
+/**
+ * Key:   PID NS ID
+ * Value: a btree:
+ *           Key:   a process PID in NS
+ *           Value: the process's PID as present in /proc
+ */
+static struct trie *ns_pid_to_proc_pid[PT_COUNT];
+
+/**
+ * Key:   Proc PID
+ * Value: struct proc_data
+ */
+static struct trie *proc_data_cache;
+
+static bool ns_get_parent_enotty = false;
+
+static const char tid_str[]  = "NSpid:\t";
+static const char tgid_str[] = "NStgid:\t";
+static const char pgid_str[] = "NSpgid:\t";
+static const char sid_str[]  = "NSsid:\t";
+
+static const struct {
+	const char *str;
+	size_t size;
+} id_strs[PT_COUNT] = {
+	[PT_TID] =  { tid_str,  sizeof(tid_str)  - 1 },
+	[PT_TGID] = { tgid_str, sizeof(tgid_str) - 1 },
+	[PT_PGID] = { pgid_str, sizeof(pgid_str) - 1 },
+	[PT_SID] =  { sid_str,  sizeof(sid_str)  - 1 },
+};
+
+
+/**
+ * Limit on PID NS hierarchy depth, imposed since Linux 3.7. NS traversal
+ * is not possible before Linux 4.9, so we consider this limit pretty universal.
+ */
+#define MAX_NS_DEPTH 32
+
+static const size_t ns_id_size = sizeof(unsigned int);
+static const uint8_t ptr_sz_lg = (sizeof(void *) == 8 ? 6 : 5);
+
+static int pid_max;
+static uint8_t pid_max_size, pid_max_size_lg;
+
+struct proc_data {
+	int proc_pid;
+	int ns_count;
+	unsigned int ns_hierarchy[MAX_NS_DEPTH];
+	int id_count[PT_COUNT];
+	int id_hierarchy[PT_COUNT][MAX_NS_DEPTH];
+};
+
+/**
+ * Helper function for creating a trie.
+ *
+ * For node_key_bits and data_block_key_bits 4 is used (so trie height is 32 / 4
+ * = 8, and node sizes are 8 byte * 2^4 = 128 bytes), which seems to be a good
+ * tradeoff between memory usage and lookup time. It should not be too large,
+ * since there can be large holes between PIDs, and it would be just a waste of
+ * memory having large nodes with lot of NULL pointers in them.
+ */
+static struct trie *
+create_trie_4(uint8_t key_size, uint8_t item_size_lg, uint64_t empty_value)
+{
+	struct trie *t = trie_create(key_size, item_size_lg, 4, 4, empty_value);
+	if (!t)
+		error_msg_and_die("creating trie failed");
+
+	return t;
+}
+
+void
+pidns_init(void)
+{
+	if (proc_data_cache)
+		return;
+
+	pid_max = INT_MAX;
+	if (read_int_from_file("/proc/sys/kernel/pid_max", &pid_max) < 0)
+		debug_func_perror_msg("reading /proc/sys/kernel/pid_max");
+	pid_max_size = ilog2_32(pid_max - 1) + 1;
+	pid_max_size_lg = ilog2_32(pid_max_size - 1) + 1;
+
+	for (int i = 0; i < PT_COUNT; i++)
+		ns_pid_to_proc_pid[i] = create_trie_4(ns_id_size, ptr_sz_lg, 0);
+
+	proc_data_cache = create_trie_4(pid_max_size, ptr_sz_lg, 0);
+}
+
+static void
+put_proc_pid(unsigned int ns, int ns_pid, enum pid_type type, int proc_pid)
+{
+	struct trie *b = (struct trie *) (uintptr_t) trie_get(ns_pid_to_proc_pid[type], ns);
+	if (!b) {
+		b = create_trie_4(pid_max_size, pid_max_size_lg, 0);
+		trie_set(ns_pid_to_proc_pid[type], ns, (uint64_t) (uintptr_t) b);
+	}
+	trie_set(b, ns_pid, proc_pid);
+}
+
+static int
+get_cached_proc_pid(unsigned int ns, int ns_pid, enum pid_type type)
+{
+	struct trie *b = (struct trie *) (uintptr_t)
+		trie_get(ns_pid_to_proc_pid[type], ns);
+	if (!b)
+		return 0;
+
+	return trie_get(b, ns_pid);
+}
+
+/**
+ * Helper function, converts pid to string, or to "self" for pid == 0.
+ * Uses static buffer for operation.
+ */
+static const char *
+pid_to_str(pid_t pid)
+{
+	if (!pid)
+		return "self";
+
+	static char buf[sizeof("-2147483648")];
+	xsprintf(buf, "%d", pid);
+	return buf;
+}
+
+/**
+ * Returns a list of PID NS IDs for the specified PID.
+ *
+ * @param proc_pid PID (as present in /proc) to get information for.
+ * @param ns_buf   Pointer to buffer that is able to contain at least
+ *                 ns_buf_size items.
+ * @return         Amount of NS in list. 0 indicates error.
+ */
+static size_t
+get_ns_hierarchy(int proc_pid, unsigned int *ns_buf, size_t ns_buf_size)
+{
+	char path[PATH_MAX + 1];
+	xsprintf(path, "/proc/%s/ns/pid", pid_to_str(proc_pid));
+
+	int fd = open_file(path, O_RDONLY);
+	if (fd < 0)
+		return 0;
+
+	size_t n = 0;
+	while (n < ns_buf_size) {
+		strace_stat_t st;
+		if (fstat_fd(fd, &st))
+			break;
+
+		ns_buf[n++] = st.st_ino;
+		if (n >= ns_buf_size)
+			break;
+
+		if (ns_get_parent_enotty)
+			break;
+
+		int parent_fd = ioctl(fd, NS_GET_PARENT);
+		if (parent_fd < 0) {
+			switch (errno) {
+			case EPERM:
+				break;
+
+			case ENOTTY:
+				ns_get_parent_enotty = true;
+				error_msg("NS_* ioctl commands are not "
+					  "supported by the kernel");
+				break;
+
+			default:
+				perror_func_msg("ioctl(NS_GET_PARENT)");
+				break;
+			}
+
+			break;
+		}
+
+		close(fd);
+		fd = parent_fd;
+	}
+
+	close(fd);
+
+	return n;
+}
+
+/**
+ * Get list of IDs present in NS* proc status record. IDs are placed as they are
+ * stored in /proc (from top to bottom of NS hierarchy).
+ *
+ * @param proc_pid    PID (as present in /proc) to get information for.
+ * @param id_buf      Pointer to buffer that is able to contain at least
+ *                    MAX_NS_DEPTH items. Can be NULL.
+ * @param type        Type of ID requested.
+ * @return            Number of items stored in id_list. 0 indicates error.
+ */
+static size_t
+get_id_list(int proc_pid, int *id_buf, enum pid_type type)
+{
+	const char *ns_str = id_strs[type].str;
+	size_t ns_str_size = id_strs[type].size;
+
+	size_t n = 0;
+
+	char status_path[PATH_MAX + 1];
+	xsprintf(status_path, "/proc/%s/status", pid_to_str(proc_pid));
+	FILE *f = fopen_stream(status_path, "r");
+	if (!f)
+		return 0;
+
+	char *line = NULL;
+	size_t linesize = 0;
+	char *p = NULL;
+
+	while (getline(&line, &linesize, f) > 0) {
+		if (strncmp(line, ns_str, ns_str_size) == 0) {
+			p = line + ns_str_size;
+			break;
+		}
+	}
+
+	while (p) {
+		errno = 0;
+		long id = strtol(p, NULL, 10);
+
+		if (errno || id < 1 || id > INT_MAX) {
+			perror_func_msg("converting pid (%ld) to int", id);
+			break;
+		}
+
+		if (id_buf)
+			id_buf[n] = (int) id;
+
+		n++;
+		strsep(&p, "\t");
+	}
+
+	free(line);
+	fclose(f);
+
+	return n;
+}
+
+/**
+ * Returns whether the /proc filesystem's PID namespace is the same as strace's.
+ */
+static bool
+is_proc_ours(void)
+{
+	static int cached_val = -1;
+
+	if (cached_val < 0)
+		cached_val = get_id_list(0, NULL, PT_TID) == 1;
+
+	return cached_val;
+}
+
+/**
+ * Returns the PID namespace of the tracee
+ */
+static unsigned int
+get_ns(struct tcb *tcp)
+{
+	if (!tcp->pid_ns) {
+		int proc_pid = 0;
+		translate_pid(NULL, tcp->pid, PT_TID, &proc_pid);
+
+		if (proc_pid)
+			get_ns_hierarchy(proc_pid, &tcp->pid_ns, 1);
+	}
+
+	return tcp->pid_ns;
+}
+
+/**
+ * Returns the PID namespace of strace
+ */
+static unsigned int
+get_our_ns(void)
+{
+	static unsigned int our_ns = 0;
+	static bool our_ns_initialised = false;
+
+	if (!our_ns_initialised) {
+		get_ns_hierarchy(0, &our_ns, 1);
+		our_ns_initialised = true;
+	}
+
+	return our_ns;
+}
+
+/**
+ * Returns the cached proc_data struct associated with proc_pid.
+ * If none found, allocates a new proc_data.
+ */
+static struct proc_data *
+get_or_create_proc_data(int proc_pid)
+{
+	struct proc_data *pd = (struct proc_data *) (uintptr_t)
+		trie_get(proc_data_cache, proc_pid);
+
+	if (!pd) {
+		pd = calloc(1, sizeof(*pd));
+		if (!pd)
+			return NULL;
+
+		pd->proc_pid = proc_pid;
+		trie_set(proc_data_cache, proc_pid, (uint64_t) (uintptr_t) pd);
+	}
+
+	return pd;
+}
+
+/**
+ * Updates the proc_data from /proc
+ * If the process does not exists, returns false, and frees the proc_data
+ */
+static bool
+update_proc_data(struct proc_data *pd, enum pid_type type)
+{
+	pd->ns_count = get_ns_hierarchy(pd->proc_pid,
+		pd->ns_hierarchy, MAX_NS_DEPTH);
+	if (!pd->ns_count)
+		goto fail;
+
+	pd->id_count[type] = get_id_list(pd->proc_pid,
+		pd->id_hierarchy[type], type);
+	if (!pd->id_count[type])
+		goto fail;
+
+	return true;
+
+fail:
+	trie_set(proc_data_cache, pd->proc_pid, (uint64_t) (uintptr_t) NULL);
+	free(pd);
+	return false;
+}
+
+/**
+ * Paramters for id translation
+ */
+struct translate_id_params {
+	/* The result (output) */
+	int result_id;
+	/* The proc data of the process (output) */
+	struct proc_data *pd;
+
+	/* The namespace to be translated from */
+	unsigned int from_ns;
+	/* The id to be translated */
+	int from_id;
+	/* The type of the id */
+	enum pid_type type;
+};
+
+/**
+ * Translates an id to our namespace, given the proc_pid of the process,
+ * by reading files in /proc.
+ *
+ * @param tip      The parameters
+ * @param proc_pid The proc pid of the process.
+ *                 If 0, use the cached values in tip->pd.
+ */
+static void
+translate_id_proc_pid(struct translate_id_params *tip, int proc_pid)
+{
+	struct proc_data *pd = proc_pid ?
+		get_or_create_proc_data(proc_pid) :
+		tip->pd;
+
+	tip->result_id = 0;
+	tip->pd = NULL;
+
+	if (!pd)
+		return;
+
+	if (proc_pid && !update_proc_data(pd, tip->type))
+		return;
+
+	if (!pd->ns_count || pd->id_count[tip->type] < pd->ns_count)
+		return;
+
+	int our_ns_id_idx = pd->id_count[tip->type] - pd->ns_count;
+
+	for (int i = 0; i < pd->ns_count; i++) {
+		if (pd->ns_hierarchy[i] != tip->from_ns)
+			continue;
+
+		int id_idx = pd->id_count[tip->type] - i - 1;
+		if (pd->id_hierarchy[tip->type][id_idx] != tip->from_id)
+			return;
+
+		tip->result_id = pd->id_hierarchy[tip->type][our_ns_id_idx];
+		tip->pd = pd;
+		return;
+	}
+}
+
+/**
+ * Translates an id to our namespace, by reading all proc entries in dir.
+ *
+ * @param tip            The parameters
+ * @param path           The path of the dir to be read.
+ * @param read_task_dir  Whether recurse to "task" subdirectory.
+ */
+static void
+translate_id_dir(struct translate_id_params *tip, const char *path,
+                 bool read_task_dir)
+{
+	DIR *dir = opendir(path);
+	if (!dir) {
+		debug_func_perror_msg("opening dir: %s", path);
+		return;
+	}
+
+	while (!tip->result_id) {
+		errno = 0;
+		struct_dirent *entry = read_dir(dir);
+		if (!entry) {
+			if (errno)
+				perror_func_msg("readdir");
+
+			break;
+		}
+
+		if (entry->d_type != DT_DIR)
+			continue;
+
+		errno = 0;
+		long proc_pid = strtol(entry->d_name, NULL, 10);
+		if (errno)
+			continue;
+		if (proc_pid < 1 || proc_pid > INT_MAX)
+			continue;
+
+		if (read_task_dir) {
+			char task_dir_path[PATH_MAX + 1];
+			xsprintf(task_dir_path, "/proc/%ld/task", proc_pid);
+			translate_id_dir(tip, task_dir_path, false);
+		}
+
+		if (tip->result_id)
+			break;
+
+		translate_id_proc_pid(tip, proc_pid);
+	}
+
+	closedir(dir);
+}
+
+/**
+ * Iterator function of the proc_data_cache for id translation.
+ * If the cache contains the id we are looking for, reads the corresponding
+ * directory in /proc, and if cache is valid, saves the result.
+ */
+static void
+proc_data_cache_iterator_fn(void* fn_data, uint64_t key, uint64_t val)
+{
+	struct translate_id_params *tip = (struct translate_id_params *)fn_data;
+	struct proc_data *pd = (struct proc_data *) (uintptr_t) val;
+
+	if (!pd)
+		return;
+
+	/* Result already found in an earlier iteration */
+	if (tip->result_id)
+		return;
+
+	/* Translate from cache */
+	tip->pd = pd;
+	translate_id_proc_pid(tip, 0);
+	if (!tip->result_id)
+		return;
+
+	/* Now translate from actual data in /proc, to check cache validity */
+	translate_id_proc_pid(tip, pd->proc_pid);
+}
+
+int
+translate_pid(struct tcb *tcp, int from_id, enum pid_type type,
+              int *proc_pid_ptr)
+{
+	if (from_id <= 0 || type < 0 || type >= PT_COUNT)
+		return 0;
+
+	/* If translation is trivial */
+	if ((!tcp || get_ns(tcp) == get_our_ns()) &&
+	    (!proc_pid_ptr || is_proc_ours())) {
+		if (proc_pid_ptr)
+			*proc_pid_ptr = from_id;
+
+		return from_id;
+	}
+
+	struct translate_id_params tip = {
+		.result_id = 0,
+		.pd = NULL,
+		.from_ns = tcp ? get_ns(tcp) : get_our_ns(),
+		.from_id = from_id,
+		.type = type,
+	};
+
+	if (!tip.from_ns)
+		return 0;
+
+	if (ns_get_parent_enotty)
+		return 0;
+
+	/* Look for a cached proc_pid for this (from_ns, from_id) pair */
+	int cached_proc_pid = get_cached_proc_pid(tip.from_ns, tip.from_id,
+		tip.type);
+	if (cached_proc_pid) {
+		translate_id_proc_pid(&tip, cached_proc_pid);
+		if (tip.result_id)
+			goto exit;
+	}
+
+	/* Iterate through the cache, find potential proc_data */
+	trie_iterate_keys(proc_data_cache, 0, pid_max,
+		proc_data_cache_iterator_fn, &tip);
+	/* (proc_data_cache_iterator_fn takes care about updating proc_data) */
+	if (tip.result_id)
+		goto exit;
+
+	/* No cache helped, read all entries in /proc */
+	translate_id_dir(&tip, "/proc", true);
+
+exit:
+	if (tip.pd) {
+		if (tip.pd->proc_pid)
+			put_proc_pid(tip.from_ns, tip.from_id, tip.type,
+				tip.pd->proc_pid);
+
+		if (proc_pid_ptr)
+			*proc_pid_ptr = tip.pd->proc_pid;
+	}
+
+	return tip.result_id;
+}
+
+int
+get_proc_pid(struct tcb *tcp)
+{
+	int proc_pid = 0;
+	translate_pid(NULL, tcp->pid, PT_TID, &proc_pid);
+	return proc_pid;
+}
+
+static void
+printpid_translation(struct tcb *tcp, int pid, enum pid_type type)
+{
+	if (!pidns_translation)
+		return;
+
+	int strace_pid = translate_pid(tcp, pid, type, NULL);
+	if (strace_pid && strace_pid != pid)
+		tprintf_comment("%d in strace's PID NS", strace_pid);
+}
+
+void
+printpid(struct tcb *tcp, int pid, enum pid_type type)
+{
+	tprintf("%d", pid);
+	printpid_translation(tcp, pid, type);
+}
+
+void
+printpid_tgid_pgid(struct tcb *tcp, int pid)
+{
+	tprintf("%d", pid);
+	if (pid > 0)
+		printpid_translation(tcp,  pid, PT_TGID);
+	else if (pid < -1)
+		printpid_translation(tcp, -pid, PT_PGID);
+}
diff --git a/strace.1.in b/strace.1.in
index 3b21caec..83776e88 100644
--- a/strace.1.in
+++ b/strace.1.in
@@ -1075,6 +1075,10 @@ Print all available information associated with file descritors:
 protocol-specific information associated with socket file descriptors,
 block/character device number associated with device file descriptors,
 and PIDs asociated with pidfd file descriptors.
+.TP
+.B \-\-pidns\-translation
+If strace and tracee are in different PID namespaces, print PIDs in
+strace's namespace, too.
 .SS Statistics
 .TP 12
 .B \-c
diff --git a/strace.c b/strace.c
index 4c96a98b..249533ea 100644
--- a/strace.c
+++ b/strace.c
@@ -133,6 +133,8 @@ static unsigned int daemonized_tracer;
 static int post_attach_sigstop = TCB_IGNORE_ONE_SIGSTOP;
 #define use_seize (post_attach_sigstop == 0)
 
+unsigned int pidns_translation;
+
 static bool detach_on_execve;
 
 static int exit_code;
@@ -1998,6 +2000,8 @@ init(int argc, char *argv[])
 
 	os_release = get_os_release();
 
+	pidns_init();
+
 	shared_log = stderr;
 	set_sortby(DEFAULT_SORTBY);
 	set_personality(DEFAULT_PERSONALITY);
@@ -2022,6 +2026,7 @@ init(int argc, char *argv[])
 		GETOPT_FOLLOWFORKS,
 		GETOPT_OUTPUT_SEPARATELY,
 		GETOPT_TS,
+		GETOPT_PIDNS_TRANSLATION,
 
 		GETOPT_QUAL_TRACE,
 		GETOPT_QUAL_ABBREV,
@@ -2072,6 +2077,7 @@ init(int argc, char *argv[])
 		{ "summary-wall-clock", no_argument,	   0, 'w' },
 		{ "strings-in-hex",	optional_argument, 0, GETOPT_HEX_STR },
 		{ "const-print-style",	required_argument, 0, 'X' },
+		{ "pidns-translation",	no_argument      , 0, GETOPT_PIDNS_TRANSLATION },
 		{ "successful-only",	no_argument,	   0, 'z' },
 		{ "failed-only",	no_argument,	   0, 'Z' },
 		{ "failing-only",	no_argument,	   0, 'Z' },
@@ -2285,6 +2291,9 @@ init(int argc, char *argv[])
 		case 'y':
 			yflag_short++;
 			break;
+		case GETOPT_PIDNS_TRANSLATION:
+			pidns_translation++;
+			break;
 		case 'z':
 			clear_number_set_array(status_set, 1);
 			add_number_to_set(STATUS_SUCCESSFUL, status_set);
diff --git a/syscall.c b/syscall.c
index bcc87025..0f4bab6d 100644
--- a/syscall.c
+++ b/syscall.c
@@ -937,6 +937,21 @@ syscall_exiting_trace(struct tcb *tcp, struct timespec *ts, int res)
 					tprintf("= %" PRI_kld, tcp->u_rval);
 				}
 				break;
+			case RVAL_TID:
+			case RVAL_SID:
+			case RVAL_TGID:
+			case RVAL_PGID: {
+				#define _(_t) [RVAL_##_t - RVAL_TID] = PT_##_t
+				static const enum pid_type types[] = {
+					_(TID), _(SID), _(TGID), _(PGID),
+				};
+				#undef _
+
+				tprints("= ");
+				printpid(tcp, tcp->u_rval,
+					 types[(sys_res & RVAL_MASK) - RVAL_TID]);
+				break;
+			}
 			default:
 				error_msg("invalid rval format");
 				break;
diff --git a/trie.c b/trie.c
new file mode 100644
index 00000000..b7d56ed5
--- /dev/null
+++ b/trie.c
@@ -0,0 +1,248 @@
+/*
+ * Simple trie implementation for key-value mapping storage
+ *
+ * Copyright (c) 2020 ?kos Uzonyi <uzonyi.akos at gmail.com>
+ * All rights reserved.
+ *
+ * SPDX-License-Identifier: LGPL-2.1-or-later
+ */
+
+#include "defs.h"
+
+#include <stdbool.h>
+#include <stdint.h>
+#include <stdlib.h>
+
+#include "trie.h"
+
+static const uint8_t ptr_sz_lg = (sizeof(void *) == 8 ? 6 : 5);
+
+/**
+ * Returns lg2 of node size in bits for the specific level of the trie.
+ */
+static uint8_t
+trie_get_node_size(struct trie *t, uint8_t depth)
+{
+	/* Last level contains data and we allow it having a different size */
+	if (depth == t->max_depth)
+		return t->data_block_key_bits + t->item_size_lg;
+	/* Last level of the tree can be smaller */
+	if (depth == t->max_depth - 1)
+		return (t->key_size - t->data_block_key_bits - 1) %
+		t->node_key_bits + 1 + ptr_sz_lg;
+
+	return t->node_key_bits + ptr_sz_lg;
+}
+
+/**
+ * Provides starting offset of bits in key corresponding to the node index
+ * at the specific level.
+ */
+static uint8_t
+trie_get_node_bit_offs(struct trie *t, uint8_t depth)
+{
+	uint8_t offs;
+
+	if (depth == t->max_depth)
+		return 0;
+
+	offs = t->data_block_key_bits;
+
+	if (depth == t->max_depth - 1)
+		return offs;
+
+	/* data_block_size + remainder */
+	offs += trie_get_node_size(t, t->max_depth - 1) - ptr_sz_lg;
+	offs += (t->max_depth - depth - 2) * t->node_key_bits;
+
+	return offs;
+}
+
+struct trie *
+trie_create(uint8_t key_size, uint8_t item_size_lg, uint8_t node_key_bits,
+            uint8_t data_block_key_bits, uint64_t empty_value)
+{
+	if (item_size_lg > 6)
+		return NULL;
+	if (key_size > 64)
+		return NULL;
+	if (node_key_bits < 1)
+		return NULL;
+	if (data_block_key_bits < 1 || data_block_key_bits > key_size)
+		return NULL;
+
+	struct trie *t = malloc(sizeof(*t));
+	if (!t)
+		return NULL;
+
+	t->empty_value = empty_value;
+	t->data = NULL;
+	t->item_size_lg = item_size_lg;
+	t->node_key_bits = node_key_bits;
+	t->data_block_key_bits = data_block_key_bits;
+	t->key_size = key_size;
+	t->max_depth = (key_size - data_block_key_bits + node_key_bits - 1)
+		/ t->node_key_bits;
+
+	return t;
+}
+
+static uint64_t *
+trie_get_node(struct trie *t, uint64_t key, bool auto_create)
+{
+	void **cur_node = &(t->data);
+
+	if (t->key_size < 64 && key > (uint64_t) 1 << t->key_size)
+		return NULL;
+
+	for (uint8_t cur_depth = 0; cur_depth <= t->max_depth; cur_depth++) {
+		uint8_t offs = trie_get_node_bit_offs(t, cur_depth);
+		uint8_t sz = trie_get_node_size(t, cur_depth);
+
+		if (!*cur_node) {
+			if (!auto_create)
+				return NULL;
+
+			*cur_node = xcalloc(1 << sz, 1);
+		}
+
+		if (cur_depth >= t->max_depth)
+			break;
+
+		size_t pos = (key >> offs) & ((1 << (sz - ptr_sz_lg)) - 1);
+		cur_node = (((void **) (*cur_node)) + pos);
+	}
+
+	return (uint64_t *) (*cur_node);
+}
+
+static void
+trie_data_block_calc_pos(struct trie *t, uint64_t key,
+                         uint64_t *pos, uint64_t *mask, uint64_t *offs)
+{
+	uint64_t key_mask;
+
+	key_mask = (1 << t->data_block_key_bits) - 1;
+	*pos = (key & key_mask) >> (6 - t->item_size_lg);
+
+	key_mask = (1 << (6 - t->item_size_lg)) - 1;
+	*offs = (key & key_mask) * (1 << t->item_size_lg);
+
+	*mask = (((uint64_t) 1 << (1 << t->item_size_lg)) - 1) << *offs;
+}
+
+bool
+trie_set(struct trie *t, uint64_t key, uint64_t val)
+{
+	uint64_t *data = trie_get_node(t, key, true);
+	if (!data)
+		return false;
+
+	uint64_t pos, mask, offs;
+	trie_data_block_calc_pos(t, key, &pos, &mask, &offs);
+
+	data[pos] &= ~mask;
+	data[pos] |= (val << offs) & mask;
+
+	return true;
+}
+
+static uint64_t
+trie_data_block_get(struct trie *t, uint64_t *data, uint64_t key)
+{
+	if (!data)
+		return t->empty_value;
+
+	uint64_t pos, mask, offs;
+	trie_data_block_calc_pos(t, key, &pos, &mask, &offs);
+
+	return (data[pos] & mask) >> offs;
+}
+
+uint64_t
+trie_get(struct trie *b, uint64_t key)
+{
+	return trie_data_block_get(b, trie_get_node(b, key, false), key);
+}
+
+static uint64_t
+trie_iterate_keys_node(struct trie *t,
+                       trie_iterate_fn fn, void *fn_data,
+                       void *node, uint64_t start, uint64_t end,
+                       uint8_t depth)
+{
+	if (start > end || !node)
+		return 0;
+
+	if (depth == t->max_depth) {
+		for (uint64_t i = start; i <= end; i++)
+			fn(fn_data, i, trie_data_block_get(t,
+				(uint64_t *) node, i));
+
+		return end - start + 1;
+	}
+
+	uint8_t parent_node_bit_off = depth == 0 ?
+		t->key_size :
+		trie_get_node_bit_offs(t, depth - 1);
+
+	uint64_t first_key_in_node = start &
+		(uint64_t) -1 << parent_node_bit_off;
+
+	uint8_t node_bit_off = trie_get_node_bit_offs(t, depth);
+	uint8_t node_key_bits = parent_node_bit_off - node_bit_off;
+	uint64_t mask = ((uint64_t) 1 << (node_key_bits)) - 1;
+	uint64_t start_index = (start >> node_bit_off) & mask;
+	uint64_t end_index = (end >> node_bit_off) & mask;
+	uint64_t child_key_count = (uint64_t) 1 << node_bit_off;
+
+	uint64_t count = 0;
+
+	for (uint64_t i = start_index; i <= end_index; i++) {
+		uint64_t child_start = first_key_in_node + i * child_key_count;
+		uint64_t child_end = first_key_in_node +
+			(i + 1) * child_key_count - 1;
+
+		if (child_start < start)
+			child_start = start;
+		if (child_end > end)
+			child_end = end;
+
+		count += trie_iterate_keys_node(t, fn, fn_data,
+			((void **) node)[i], child_start, child_end,
+			depth + 1);
+	}
+
+	return count;
+}
+
+uint64_t trie_iterate_keys(struct trie *t, uint64_t start, uint64_t end,
+                           trie_iterate_fn fn, void *fn_data)
+{
+	return trie_iterate_keys_node(t, fn, fn_data, t->data,
+		start, end, 0);
+}
+
+static void
+trie_free_node(struct trie *t, void *node, uint8_t depth)
+{
+	if (!node)
+		return;
+
+	if (depth >= t->max_depth)
+		goto free_node;
+
+	size_t sz = 1 << (trie_get_node_size(t, depth) - ptr_sz_lg);
+	for (size_t i = 0; i < sz; i++)
+		trie_free_node(t, ((void **) node)[i], depth + 1);
+
+free_node:
+	free(node);
+}
+
+void
+trie_free(struct trie *t)
+{
+	trie_free_node(t, t->data, 0);
+	free(t);
+}
diff --git a/trie.h b/trie.h
new file mode 100644
index 00000000..1ff31397
--- /dev/null
+++ b/trie.h
@@ -0,0 +1,89 @@
+/*
+ * Simple trie interface
+ *
+ * Copyright (c) 2020 ?kos Uzonyi <uzonyi.akos at gmail.com>
+ * All rights reserved.
+ *
+ * SPDX-License-Identifier: LGPL-2.1-or-later
+ */
+
+#ifndef STRACE_TRIE_H
+#define STRACE_TRIE_H
+
+/**
+ * Trie control structure.
+ * Trie implemented here has the following properties:
+ *  * It allows storing values of the same size, the size can vary from 1 bit to
+ *    64 bit values (only power of 2 sizes are allowed).
+ *  * The key can be up to 64 bits in size.
+ *  * It has separate configuration for node size and data block size.
+ *
+ * How bits of key are used for different node levels:
+ *
+ *   highest bits                                                  lowest bits
+ *  | node_key_bits | node_key_bits | ... | <remainder> | data_block_key_bits |
+ *  \_________________________________________________________________________/
+ *                                 key_size
+ *
+ * So, the remainder is used on the lowest non-data node level.
+ *
+ * As of now, it doesn't implement any mechanisms for resizing/changing key
+ * size.  De-fragmentation is also unsupported currently.
+ */
+struct trie {
+	/** Return value of trie_get if key is not found */
+	uint64_t empty_value;
+
+	/** Pointer to root node */
+	void *data;
+
+	/** Key size in bits (0..64). */
+	uint8_t key_size;
+
+	/**
+	 * Size of the stored values in log2 bits (0..6).
+	 * (6: 64 bit values, 5: 32 bit values, ...)
+	 */
+	uint8_t item_size_lg;
+
+	/**
+	 * Number of bits in the key that make a symbol for a node.
+	 * (equals to log2 of the child count of the node)
+	 */
+	uint8_t node_key_bits;
+
+	/**
+	 * Number of bits in the key that make a symbol for the data block (leaf).
+	 * (equals to log2 of the value count stored in a data block)
+	 */
+	uint8_t data_block_key_bits;
+
+	/** The depth of the data block. Calculated from the values above */
+	uint8_t max_depth;
+};
+
+struct trie* trie_create(uint8_t key_size, uint8_t item_size_lg,
+			uint8_t node_key_bits, uint8_t data_block_key_bits,
+			uint64_t empty_value);
+
+bool trie_set(struct trie *t, uint64_t key, uint64_t val);
+uint64_t trie_get(struct trie *t, uint64_t key);
+
+typedef void (*trie_iterate_fn)(void *data, uint64_t key, uint64_t val);
+
+/**
+ * Calls trie_iterate_fn for each key-value pair where
+ * key is inside the [start, end] interval (inclusive).
+ *
+ * @param t        The trie.
+ * @param start    The start of the key interval (inclusive).
+ * @param end      The end of the key interval (inclusive).
+ * @param fn       The function to be called.
+ * @param fn_data  The value to be passed to fn.
+ */
+uint64_t trie_iterate_keys(struct trie *t, uint64_t start, uint64_t end,
+			    trie_iterate_fn fn, void *fn_data);
+
+void trie_free(struct trie *t);
+
+#endif /* !STRACE_TRIE_H */
-- 
2.27.0


From uzonyi.akos at gmail.com  Sun Aug  9 14:13:04 2020
From: uzonyi.akos at gmail.com (=?UTF-8?q?=C3=81kos=20Uzonyi?=)
Date: Sun,  9 Aug 2020 16:13:04 +0200
Subject: [PATCH v8 3/5] Use get_proc_pid for /proc paths
In-Reply-To: <20200809141306.477539-1-uzonyi.akos@gmail.com>
References: <20200809141306.477539-1-uzonyi.akos@gmail.com>
Message-ID: <20200809141306.477539-4-uzonyi.akos@gmail.com>

* mmap_cache.c (mmap_cache_rebuild_if_invalid): Use proc pid instead of
tcp->pid for /proc path.
* util.c (getfdproto): Likewise.
(pidfd_get_pid): Likewise.
* pathtrace.c (getfdpath_pid): Likewise.
* strace.c (attach_tcb): Likewise.
---
 mmap_cache.c | 2 +-
 pathtrace.c  | 7 ++++++-
 strace.c     | 2 +-
 util.c       | 9 +++++++--
 4 files changed, 15 insertions(+), 5 deletions(-)

diff --git a/mmap_cache.c b/mmap_cache.c
index 89c62254..9825df26 100644
--- a/mmap_cache.c
+++ b/mmap_cache.c
@@ -84,7 +84,7 @@ mmap_cache_rebuild_if_invalid(struct tcb *tcp, const char *caller)
 		return MMAP_CACHE_REBUILD_READY;
 
 	char filename[sizeof("/proc/4294967296/maps")];
-	xsprintf(filename, "/proc/%u/maps", tcp->pid);
+	xsprintf(filename, "/proc/%u/maps", get_proc_pid(tcp));
 
 	FILE *fp = fopen_stream(filename, "r");
 	if (!fp) {
diff --git a/pathtrace.c b/pathtrace.c
index 5b60762b..afed770a 100644
--- a/pathtrace.c
+++ b/pathtrace.c
@@ -87,7 +87,12 @@ getfdpath_pid(pid_t pid, int fd, char *buf, unsigned bufsize)
 	if (fd < 0)
 		return -1;
 
-	xsprintf(linkpath, "/proc/%u/fd/%u", pid, fd);
+	int proc_pid = 0;
+	translate_pid(NULL, pid, PT_TID, &proc_pid);
+	if (!proc_pid)
+		return -1;
+
+	xsprintf(linkpath, "/proc/%u/fd/%u", proc_pid, fd);
 	n = readlink(linkpath, buf, bufsize - 1);
 	/*
 	 * NB: if buf is too small, readlink doesn't fail,
diff --git a/strace.c b/strace.c
index 249533ea..ef23f08f 100644
--- a/strace.c
+++ b/strace.c
@@ -1196,7 +1196,7 @@ attach_tcb(struct tcb *const tcp)
 	unsigned int ntid = 0, nerr = 0;
 
 	if (followfork && tcp->pid != strace_child &&
-	    xsprintf(procdir, task_path, tcp->pid) > 0 &&
+	    xsprintf(procdir, task_path, get_proc_pid(tcp)) > 0 &&
 	    (dir = opendir(procdir)) != NULL) {
 		struct_dirent *de;
 
diff --git a/util.c b/util.c
index 2568021e..481144bf 100644
--- a/util.c
+++ b/util.c
@@ -501,7 +501,7 @@ getfdproto(struct tcb *tcp, int fd)
 	if (fd < 0)
 		return SOCK_PROTO_UNKNOWN;
 
-	xsprintf(path, "/proc/%u/fd/%u", tcp->pid, fd);
+	xsprintf(path, "/proc/%u/fd/%u", get_proc_pid(tcp), fd);
 	r = getxattr(path, "system.sockprotoname", buf, bufsize - 1);
 	if (r <= 0)
 		return SOCK_PROTO_UNKNOWN;
@@ -582,8 +582,13 @@ printdev(struct tcb *tcp, int fd, const char *path)
 pid_t
 pidfd_get_pid(pid_t pid_of_fd, int fd)
 {
+	int proc_pid = 0;
+	translate_pid(NULL, pid_of_fd, PT_TID, &proc_pid);
+	if (!proc_pid)
+		return -1;
+
 	char fdi_path[sizeof("/proc/%u/fdinfo/%u") + 2 * sizeof(int) * 3];
-	xsprintf(fdi_path, "/proc/%u/fdinfo/%u", pid_of_fd, fd);
+	xsprintf(fdi_path, "/proc/%u/fdinfo/%u", proc_pid, fd);
 
 	FILE *f = fopen_stream(fdi_path, "r");
 	if (!f)
-- 
2.27.0


From uzonyi.akos at gmail.com  Sun Aug  9 14:13:03 2020
From: uzonyi.akos at gmail.com (=?UTF-8?q?=C3=81kos=20Uzonyi?=)
Date: Sun,  9 Aug 2020 16:13:03 +0200
Subject: [PATCH v8 2/5] Use printpid in decoders
In-Reply-To: <20200809141306.477539-1-uzonyi.akos@gmail.com>
References: <20200809141306.477539-1-uzonyi.akos@gmail.com>
Message-ID: <20200809141306.477539-3-uzonyi.akos@gmail.com>

* getpid.c: New file.
* Makefile.am (libstrace_a_SOURCES): Add it.
* linux/dummy.h (sys_getpid, sys_getppid, sys_gettid,
sys_setpgid, sys_setpgrp): Remove.
* util.c (printfd_pid_tracee_ns): Implement using translate_pid.
* defs.h (printnum_pid): New function definition.
(printfd_pid_tracee_ns): Update documentation
* util.c: (printnum_pid): New function.
* print_fields.h (PRINT_FIELD_TID): New macro.
(PRINT_FIELD_TGID): Likewise.
(PRINT_FIELD_PGID): Likewise.
(PRINT_FIELD_SID): Likewise.
* affinity.c: Print PIDs with printpid.
* block.c: Likewise.
* bpf.c: Likewise.
* capability.c: Likewise.
* clone.c: Likewise.
* fcntl.c: Likewise.
* get_robust_list.c: Likewise.
* ioprio.c: Likewise.
* kcmp.c: Likewise.
* msghdr.c: Likewise.
* net.c: Likewise.
* netlink.c: Likewise.
* numa.c: Likewise.
* pidfd_open.c: Likewise.
* printsiginfo.c: Likewise.
* process.c: Likewise.
* process_vm.c: Likewise.
* resource.c: Likewise.
* sched.c: Likewise.
* signal.c: Likewise.
* sockaddr.c: Likewise.
* wait.c: Likewise.
* kcmp.c (SYS_FUNC(kcmp)): Fix KCMP_FILE pid arguments.
* tests/kcmp.c (printpidfd): Print path if VERBOSE_FD.
(main): Use our real pid if real fds are used.
---
 Makefile.am       |  1 +
 affinity.c        |  6 ++++--
 block.c           |  2 +-
 bpf.c             |  2 +-
 capability.c      |  4 +++-
 clone.c           | 14 +++++++-------
 defs.h            |  5 ++++-
 fcntl.c           | 24 ++++++++++++++++++++++--
 get_robust_list.c |  3 ++-
 getpid.c          | 46 ++++++++++++++++++++++++++++++++++++++++++++++
 ioprio.c          | 26 ++++++++++++++++++++++----
 ipc_shmctl.c      |  4 ++--
 kcmp.c            |  5 ++++-
 linux/dummy.h     |  8 +-------
 msghdr.c          |  2 +-
 net.c             |  2 +-
 netlink.c         |  5 +++--
 numa.c            |  6 ++++--
 pidfd_open.c      |  2 +-
 print_fields.h    | 24 ++++++++++++++++++++++++
 printsiginfo.c    |  2 +-
 process.c         |  3 ++-
 process_vm.c      |  6 ++++--
 resource.c        | 27 ++++++++++++++++++++++++---
 sched.c           | 25 ++++++++++++++++---------
 signal.c          | 21 +++++++++++++++------
 sockaddr.c        |  2 +-
 tests/kcmp.c      | 25 ++++++++++++++++++++++---
 util.c            | 22 +++++++++++++++-------
 wait.c            | 36 ++++++++++++++++++++++++------------
 30 files changed, 278 insertions(+), 82 deletions(-)
 create mode 100644 getpid.c

diff --git a/Makefile.am b/Makefile.am
index 73c22035..15fcd9a6 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -135,6 +135,7 @@ libstrace_a_SOURCES =	\
 	getcpu.c	\
 	getcwd.c	\
 	getpagesize.c \
+	getpid.c	\
 	getrandom.c	\
 	hdio.c		\
 	hostname.c	\
diff --git a/affinity.c b/affinity.c
index eb3158b7..f9893adb 100644
--- a/affinity.c
+++ b/affinity.c
@@ -82,7 +82,8 @@ SYS_FUNC(sched_setaffinity)
 	const int pid = tcp->u_arg[0];
 	const unsigned int len = tcp->u_arg[1];
 
-	tprintf("%d, %u, ", pid, len);
+	printpid(tcp, pid, PT_TGID);
+	tprintf(", %u, ", len);
 	print_affinitylist(tcp, tcp->u_arg[2], len);
 
 	return RVAL_DECODED;
@@ -94,7 +95,8 @@ SYS_FUNC(sched_getaffinity)
 	const unsigned int len = tcp->u_arg[1];
 
 	if (entering(tcp)) {
-		tprintf("%d, %u, ", pid, len);
+		printpid(tcp, pid, PT_TGID);
+		tprintf(", %u, ", len);
 	} else {
 		print_affinitylist(tcp, tcp->u_arg[2], tcp->u_rval);
 	}
diff --git a/block.c b/block.c
index b527ef43..783a4b5a 100644
--- a/block.c
+++ b/block.c
@@ -179,7 +179,7 @@ MPERS_PRINTER_DECL(int, block_ioctl, struct tcb *const tcp,
 			PRINT_FIELD_U(", ", buts, buf_nr);
 			PRINT_FIELD_U(", ", buts, start_lba);
 			PRINT_FIELD_U(", ", buts, end_lba);
-			PRINT_FIELD_D(", ", buts, pid);
+			PRINT_FIELD_TGID(", ", buts, pid, tcp);
 			return 0;
 		} else {
 			struct_blk_user_trace_setup buts;
diff --git a/bpf.c b/bpf.c
index af830053..0ec33ba4 100644
--- a/bpf.c
+++ b/bpf.c
@@ -927,7 +927,7 @@ BEGIN_BPF_CMD_DECODER(BPF_TASK_FD_QUERY)
 	if (entering(tcp)) {
 		set_tcb_priv_ulong(tcp, attr.buf_len);
 
-		PRINT_FIELD_D("{task_fd_query={", attr, pid);
+		PRINT_FIELD_TGID("{task_fd_query={", attr, pid, tcp);
 		PRINT_FIELD_FD(", ", attr, fd, tcp);
 		PRINT_FIELD_U(", ", attr, flags);
 		PRINT_FIELD_U(", ", attr, buf_len);
diff --git a/capability.c b/capability.c
index 0e763ee1..812fb435 100644
--- a/capability.c
+++ b/capability.c
@@ -70,7 +70,9 @@ print_cap_header(struct tcb *const tcp, const kernel_ulong_t addr,
 	tprints("{version=");
 	printxval(cap_version, h->version,
 		  "_LINUX_CAPABILITY_VERSION_???");
-	tprintf(", pid=%d}", h->pid);
+	tprints(", pid=");
+	printpid(tcp, h->pid, PT_TGID);
+	tprints("}");
 }
 
 static void
diff --git a/clone.c b/clone.c
index 487c5c23..45f24065 100644
--- a/clone.c
+++ b/clone.c
@@ -114,14 +114,14 @@ SYS_FUNC(clone)
 		 */
 		if ((flags & (CLONE_PARENT_SETTID|CLONE_PIDFD|CLONE_CHILD_SETTID
 			      |CLONE_CHILD_CLEARTID|CLONE_SETTLS)) == 0)
-			return RVAL_DECODED;
+			return RVAL_DECODED | RVAL_TID;
 	} else {
 		if (flags & (CLONE_PARENT_SETTID|CLONE_PIDFD)) {
 			kernel_ulong_t addr = tcp->u_arg[ARG_PTID];
 
 			tprints(", parent_tid=");
 			if (flags & CLONE_PARENT_SETTID)
-				printnum_int(tcp, addr, "%u");
+				printnum_pid(tcp, addr, PT_TID);
 			else
 				printnum_fd(tcp, addr);
 		}
@@ -134,7 +134,7 @@ SYS_FUNC(clone)
 			printaddr(tcp->u_arg[ARG_CTID]);
 		}
 	}
-	return 0;
+	return RVAL_TID;
 }
 
 
@@ -229,7 +229,7 @@ SYS_FUNC(clone3)
 
 		if ((arg.flags & (CLONE_PIDFD | CLONE_PARENT_SETTID)) ||
 		    (size > fetch_size))
-			return 0;
+			return RVAL_TID;
 
 		goto out;
 	}
@@ -256,7 +256,7 @@ SYS_FUNC(clone3)
 
 	if (arg.flags & CLONE_PARENT_SETTID) {
 		tprintf("%sparent_tid=", pfx);
-		printnum_int(tcp, arg.parent_tid, "%d"); /* TID */
+		printnum_pid(tcp, arg.parent_tid, PT_TID);
 		pfx = ", ";
 	}
 
@@ -279,7 +279,7 @@ SYS_FUNC(clone3)
 out:
 	tprintf(", %" PRI_klu, size);
 
-	return RVAL_DECODED;
+	return RVAL_DECODED | RVAL_TID;
 }
 
 
@@ -300,5 +300,5 @@ SYS_FUNC(unshare)
 
 SYS_FUNC(fork)
 {
-	return RVAL_DECODED;
+	return RVAL_DECODED | RVAL_TGID;
 }
diff --git a/defs.h b/defs.h
index 511a92a2..328c1940 100644
--- a/defs.h
+++ b/defs.h
@@ -1100,7 +1100,7 @@ printfd(struct tcb *tcp, int fd)
 
 /**
  * Print file descriptor fd owned by process with ID pid (from the PID NS
- * of the tracee the descriptor tcp).  This is a stub.
+ * of the tracee).
  */
 extern void printfd_pid_tracee_ns(struct tcb *tcp, pid_t pid, int fd);
 
@@ -1561,6 +1561,9 @@ DECL_PRINTNUM_ADDR(int64);
 extern bool
 printnum_fd(struct tcb *, kernel_ulong_t addr);
 
+extern bool
+printnum_pid(struct tcb *const tcp, const kernel_ulong_t addr, enum pid_type type);
+
 static inline bool
 printnum_slong(struct tcb *tcp, kernel_ulong_t addr)
 {
diff --git a/fcntl.c b/fcntl.c
index 6fcd5dac..5c630a06 100644
--- a/fcntl.c
+++ b/fcntl.c
@@ -28,7 +28,7 @@ print_struct_flock64(struct tcb *const tcp, const struct_kernel_flock64 *fl, con
 	PRINT_FIELD_D(", ", *fl, l_start);
 	PRINT_FIELD_D(", ", *fl, l_len);
 	if (getlk)
-		PRINT_FIELD_D(", ", *fl, l_pid);
+		PRINT_FIELD_TGID(", ", *fl, l_pid, tcp);
 	tprints("}");
 }
 
@@ -59,7 +59,22 @@ print_f_owner_ex(struct tcb *const tcp, const kernel_ulong_t addr)
 		return;
 
 	PRINT_FIELD_XVAL("{", owner, type, f_owner_types, "F_OWNER_???");
-	PRINT_FIELD_D(", ", owner, pid);
+
+	enum pid_type pid_type = PT_NONE;
+	switch (owner.type)
+	{
+	case F_OWNER_TID:
+		pid_type = PT_TID;
+		break;
+	case F_OWNER_PID:
+		pid_type = PT_TGID;
+		break;
+	case F_OWNER_PGRP:
+		pid_type = PT_PGID;
+		break;
+	}
+	tprints(", pid=");
+	printpid(tcp, owner.pid, pid_type);
 	tprints("}");
 }
 
@@ -74,6 +89,9 @@ print_fcntl(struct tcb *tcp)
 		printflags(fdflags, tcp->u_arg[2], "FD_???");
 		break;
 	case F_SETOWN:
+		tprints(", ");
+		printpid_tgid_pgid(tcp, tcp->u_arg[2]);
+		break;
 	case F_SETPIPE_SZ:
 		tprintf(", %" PRI_kld, tcp->u_arg[2]);
 		break;
@@ -116,6 +134,8 @@ print_fcntl(struct tcb *tcp)
 		printsignal(tcp->u_arg[2]);
 		break;
 	case F_GETOWN:
+		return RVAL_DECODED |
+		       ((int) tcp->u_rval < 0 ? RVAL_PGID : RVAL_TGID);
 	case F_GETPIPE_SZ:
 		break;
 	case F_GETFD:
diff --git a/get_robust_list.c b/get_robust_list.c
index b5aebaff..81aba2dd 100644
--- a/get_robust_list.c
+++ b/get_robust_list.c
@@ -10,7 +10,8 @@
 SYS_FUNC(get_robust_list)
 {
 	if (entering(tcp)) {
-		tprintf("%d, ", (int) tcp->u_arg[0]);
+		printpid(tcp, tcp->u_arg[0], PT_TID);
+		tprints(", ");
 	} else {
 		printnum_ptr(tcp, tcp->u_arg[1]);
 		tprints(", ");
diff --git a/getpid.c b/getpid.c
new file mode 100644
index 00000000..5e9a1a29
--- /dev/null
+++ b/getpid.c
@@ -0,0 +1,46 @@
+/*
+ * Copyright (c) 2020 ?kos Uzonyi <uzonyi.akos at gmail.com>
+ * All rights reserved.
+ *
+ * SPDX-License-Identifier: LGPL-2.1-or-later
+ */
+
+#include "defs.h"
+
+SYS_FUNC(getpid)
+{
+	return RVAL_DECODED | RVAL_TGID;
+}
+
+SYS_FUNC(gettid)
+{
+	return RVAL_DECODED | RVAL_TID;
+}
+
+SYS_FUNC(getpgrp)
+{
+	return RVAL_DECODED | RVAL_PGID;
+}
+
+SYS_FUNC(getpgid)
+{
+	printpid(tcp, tcp->u_arg[0], PT_TGID);
+
+	return RVAL_DECODED | RVAL_PGID;
+}
+
+SYS_FUNC(getsid)
+{
+	printpid(tcp, tcp->u_arg[0], PT_TGID);
+
+	return RVAL_DECODED | RVAL_SID;
+}
+
+SYS_FUNC(setpgid)
+{
+	printpid(tcp, tcp->u_arg[0], PT_TGID);
+	tprints(", ");
+	printpid(tcp, tcp->u_arg[1], PT_PGID);
+
+	return RVAL_DECODED;
+}
diff --git a/ioprio.c b/ioprio.c
index 873c8ce5..149ef3fd 100644
--- a/ioprio.c
+++ b/ioprio.c
@@ -49,13 +49,30 @@ print_ioprio(unsigned int ioprio)
 		? tprints_comment : tprints)(str);
 }
 
+static void
+ioprio_print_who(struct tcb *tcp, int which, int who)
+{
+	switch (which)
+	{
+	case IOPRIO_WHO_PROCESS:
+		printpid(tcp, who, PT_TGID);
+		break;
+	case IOPRIO_WHO_PGRP:
+		printpid(tcp, who, PT_PGID);
+		break;
+	default:
+		tprintf("%d", who);
+		break;
+	}
+}
+
 SYS_FUNC(ioprio_get)
 {
 	if (entering(tcp)) {
 		/* int which */
 		printxval(ioprio_who, tcp->u_arg[0], "IOPRIO_WHO_???");
-		/* int who */
-		tprintf(", %d", (int) tcp->u_arg[1]);
+		tprints(", ");
+		ioprio_print_who(tcp, tcp->u_arg[0], tcp->u_arg[1]);
 		return 0;
 	} else {
 		if (syserror(tcp))
@@ -72,8 +89,9 @@ SYS_FUNC(ioprio_set)
 {
 	/* int which */
 	printxval(ioprio_who, tcp->u_arg[0], "IOPRIO_WHO_???");
-	/* int who */
-	tprintf(", %d, ", (int) tcp->u_arg[1]);
+	tprints(", ");
+	ioprio_print_who(tcp, tcp->u_arg[0], tcp->u_arg[1]);
+	tprints(", ");
 	/* int ioprio */
 	if (xlat_verbose(xlat_verbosity) != XLAT_STYLE_ABBREV)
 		tprintf("%d", (int) tcp->u_arg[2]);
diff --git a/ipc_shmctl.c b/ipc_shmctl.c
index 8c9e1e7a..1f99f02a 100644
--- a/ipc_shmctl.c
+++ b/ipc_shmctl.c
@@ -53,8 +53,8 @@ print_shmid_ds(struct tcb *const tcp, const kernel_ulong_t addr, int cmd)
 		PRINT_FIELD_UID(", ", shmid_ds.shm_perm, cgid);
 		tprints("}");
 		tprintf(", shm_segsz=%u", (unsigned) shmid_ds.shm_segsz);
-		PRINT_FIELD_D(", ", shmid_ds, shm_cpid);
-		PRINT_FIELD_D(", ", shmid_ds, shm_lpid);
+		PRINT_FIELD_TGID(", ", shmid_ds, shm_cpid, tcp);
+		PRINT_FIELD_TGID(", ", shmid_ds, shm_lpid, tcp);
 		tprintf(", shm_nattch=%u", (unsigned) shmid_ds.shm_nattch);
 		tprintf(", shm_atime=%u", (unsigned) shmid_ds.shm_atime);
 		tprintf(", shm_dtime=%u", (unsigned) shmid_ds.shm_dtime);
diff --git a/kcmp.c b/kcmp.c
index 62115555..a5e1cdce 100644
--- a/kcmp.c
+++ b/kcmp.c
@@ -30,7 +30,10 @@ SYS_FUNC(kcmp)
 	kernel_ulong_t idx1 = tcp->u_arg[3];
 	kernel_ulong_t idx2 = tcp->u_arg[4];
 
-	tprintf("%d, %d, ", pid1, pid2);
+	printpid(tcp, pid1, PT_TGID);
+	tprints(", ");
+	printpid(tcp, pid2, PT_TGID);
+	tprints(", ");
 	printxval(kcmp_types, type, "KCMP_???");
 
 	switch (type) {
diff --git a/linux/dummy.h b/linux/dummy.h
index 2f859a60..ca0d2f0c 100644
--- a/linux/dummy.h
+++ b/linux/dummy.h
@@ -53,6 +53,7 @@
 # define sys_getgid		sys_getuid
 # define sys_getgid16		sys_getuid16
 # define sys_getpeername		sys_getsockname
+# define sys_getppid		sys_getpid
 # define sys_getresgid		sys_getresuid
 # define sys_getresgid16		sys_getresuid16
 # define sys_lstat		sys_stat
@@ -87,10 +88,6 @@
 # define sys_vfork		sys_fork
 
 /* printargs does the right thing */
-# define sys_getpgrp		printargs
-# define sys_getpid		printargs
-# define sys_getppid		printargs
-# define sys_gettid		printargs
 # define sys_idle		printargs
 # define sys_munlockall		printargs
 # define sys_pause		printargs
@@ -108,10 +105,7 @@
 
 /* printargs_d does the right thing */
 # define sys_exit		printargs_d
-# define sys_getpgid		printargs_d
-# define sys_getsid		printargs_d
 # define sys_nice		printargs_d
-# define sys_setpgid		printargs_d
 # define sys_setpgrp		printargs_d
 # define sys_timer_delete	printargs_d
 # define sys_timer_getoverrun	printargs_d
diff --git a/msghdr.c b/msghdr.c
index ef6dc24b..170b8e51 100644
--- a/msghdr.c
+++ b/msghdr.c
@@ -69,7 +69,7 @@ print_scm_creds(struct tcb *tcp, const void *cmsg_data,
 {
 	const struct ucred *uc = cmsg_data;
 
-	PRINT_FIELD_D("{", *uc, pid);
+	PRINT_FIELD_TGID("{", *uc, pid, tcp);
 	PRINT_FIELD_UID(", ", *uc, uid);
 	PRINT_FIELD_UID(", ", *uc, gid);
 	tprints("}");
diff --git a/net.c b/net.c
index fa4638e7..2099f0ac 100644
--- a/net.c
+++ b/net.c
@@ -601,7 +601,7 @@ print_get_ucred(struct tcb *const tcp, const kernel_ulong_t addr,
 	if (umoven_or_printaddr(tcp, addr, len, &uc))
 		return;
 
-	PRINT_FIELD_LEN("{", uc, pid, len, PRINT_FIELD_D);
+	PRINT_FIELD_LEN("{", uc, pid, len, PRINT_FIELD_TGID, tcp);
 	PRINT_FIELD_LEN(", ", uc, uid, len, PRINT_FIELD_UID);
 	PRINT_FIELD_LEN(", ", uc, gid, len, PRINT_FIELD_UID);
 	tprints("}");
diff --git a/netlink.c b/netlink.c
index 88d864a9..cb29033a 100644
--- a/netlink.c
+++ b/netlink.c
@@ -446,8 +446,9 @@ print_nlmsghdr(struct tcb *tcp,
 	decode_nlmsg_flags(nlmsghdr->nlmsg_flags,
 			   nlmsghdr->nlmsg_type, family);
 
-	tprintf(", seq=%u, pid=%d}", nlmsghdr->nlmsg_seq,
-		nlmsghdr->nlmsg_pid);
+	tprintf(", seq=%u, pid=", nlmsghdr->nlmsg_seq);
+	printpid(tcp, nlmsghdr->nlmsg_pid, PT_TGID);
+	tprints("}");
 }
 
 static bool
diff --git a/numa.c b/numa.c
index cc7a7cc6..f7a58266 100644
--- a/numa.c
+++ b/numa.c
@@ -44,7 +44,8 @@ print_nodemask(struct tcb *const tcp, const kernel_ulong_t addr,
 
 SYS_FUNC(migrate_pages)
 {
-	tprintf("%d, %" PRI_klu ", ", (int) tcp->u_arg[0], tcp->u_arg[1]);
+	printpid(tcp, tcp->u_arg[0], PT_TGID);
+	tprintf(", %" PRI_klu ", ", tcp->u_arg[1]);
 	print_nodemask(tcp, tcp->u_arg[2], tcp->u_arg[1]);
 	tprints(", ");
 	print_nodemask(tcp, tcp->u_arg[3], tcp->u_arg[1]);
@@ -170,7 +171,8 @@ SYS_FUNC(move_pages)
 	kernel_ulong_t buf;
 
 	if (entering(tcp)) {
-		tprintf("%d, %" PRI_klu ", ", (int) tcp->u_arg[0], npages);
+		printpid(tcp, tcp->u_arg[0], PT_TGID);
+		tprintf(", %" PRI_klu ", ", npages);
 		print_array(tcp, tcp->u_arg[2], npages, &buf, current_wordsize,
 			    tfetch_mem, print_addr, 0);
 		tprints(", ");
diff --git a/pidfd_open.c b/pidfd_open.c
index bbc7f617..cf05a110 100644
--- a/pidfd_open.c
+++ b/pidfd_open.c
@@ -10,7 +10,7 @@
 SYS_FUNC(pidfd_open)
 {
 	/* pid_t pid */
-	tprintf("%d", (int) tcp->u_arg[0]);
+	printpid(tcp, tcp->u_arg[0], PT_TGID);
 
 	/* unsigned int flags */
 	tprintf(", %#x", (unsigned int) tcp->u_arg[1]);
diff --git a/print_fields.h b/print_fields.h
index f9714115..33d4a458 100644
--- a/print_fields.h
+++ b/print_fields.h
@@ -263,6 +263,30 @@
 		printfd((tcp_), (where_).field_);			\
 	} while (0)
 
+# define PRINT_FIELD_TID(prefix_, where_, field_, tcp_)			\
+	do {								\
+		STRACE_PRINTF("%s%s=", (prefix_), #field_);		\
+		printpid((tcp_), (where_).field_, PT_TID);			\
+	} while (0)
+
+# define PRINT_FIELD_TGID(prefix_, where_, field_, tcp_)			\
+	do {								\
+		STRACE_PRINTF("%s%s=", (prefix_), #field_);		\
+		printpid((tcp_), (where_).field_, PT_TGID);			\
+	} while (0)
+
+# define PRINT_FIELD_PGID(prefix_, where_, field_, tcp_)			\
+	do {								\
+		STRACE_PRINTF("%s%s=", (prefix_), #field_);		\
+		printpid((tcp_), (where_).field_, PT_PGID);			\
+	} while (0)
+
+# define PRINT_FIELD_SID(prefix_, where_, field_, tcp_)			\
+	do {								\
+		STRACE_PRINTF("%s%s=", (prefix_), #field_);		\
+		printpid((tcp_), (where_).field_, PT_SID);			\
+	} while (0)
+
 # define PRINT_FIELD_STRN(prefix_, where_, field_, len_, tcp_)		\
 	do {								\
 		STRACE_PRINTF("%s%s=", (prefix_), #field_);		\
diff --git a/printsiginfo.c b/printsiginfo.c
index 8ed1e7ba..cb4cde4a 100644
--- a/printsiginfo.c
+++ b/printsiginfo.c
@@ -58,7 +58,7 @@
 static void
 printsigsource(struct tcb *tcp, const siginfo_t *sip)
 {
-	PRINT_FIELD_D(", ", *sip, si_pid);
+	PRINT_FIELD_TGID(", ", *sip, si_pid, tcp);
 	PRINT_FIELD_UID(", ", *sip, si_uid);
 }
 
diff --git a/process.c b/process.c
index a98c304e..d6ff255d 100644
--- a/process.c
+++ b/process.c
@@ -92,7 +92,8 @@ SYS_FUNC(ptrace)
 		}
 
 		/* pid */
-		tprintf(", %d", pid);
+		tprints(", ");
+		printpid(tcp, pid, PT_TGID);
 
 		/* addr */
 		switch (request) {
diff --git a/process_vm.c b/process_vm.c
index abee1e68..81d9b0f4 100644
--- a/process_vm.c
+++ b/process_vm.c
@@ -13,7 +13,8 @@ SYS_FUNC(process_vm_readv)
 {
 	if (entering(tcp)) {
 		/* arg 1: pid */
-		tprintf("%d, ", (int) tcp->u_arg[0]);
+		printpid(tcp, tcp->u_arg[0], PT_TGID);
+		tprints(", ");
 	} else {
 		kernel_ulong_t local_iovcnt = tcp->u_arg[2];
 		kernel_ulong_t remote_iovcnt = tcp->u_arg[4];
@@ -42,7 +43,8 @@ SYS_FUNC(process_vm_writev)
 	kernel_ulong_t flags = tcp->u_arg[5];
 
 	/* arg 1: pid */
-	tprintf("%d, ", (int) tcp->u_arg[0]);
+	printpid(tcp, tcp->u_arg[0], PT_TGID);
+	tprints(", ");
 	/* arg 2: local iov */
 	tprint_iov(tcp, local_iovcnt, tcp->u_arg[1], IOV_DECODE_STR);
 	/* arg 3: local iovcnt */
diff --git a/resource.c b/resource.c
index 53192ee9..070f4740 100644
--- a/resource.c
+++ b/resource.c
@@ -142,7 +142,8 @@ SYS_FUNC(setrlimit)
 SYS_FUNC(prlimit64)
 {
 	if (entering(tcp)) {
-		tprintf("%d, ", (int) tcp->u_arg[0]);
+		printpid(tcp, tcp->u_arg[0], PT_TGID);
+		tprints(", ");
 		printxval(resources, tcp->u_arg[1], "RLIMIT_???");
 		tprints(", ");
 		print_rlimit64(tcp, tcp->u_arg[2]);
@@ -179,10 +180,28 @@ SYS_FUNC(osf_getrusage)
 
 #include "xlat/priorities.h"
 
+static void
+priority_print_who(struct tcb *tcp, int which, int who)
+{
+	switch (which)
+	{
+	case PRIO_PROCESS:
+		printpid(tcp, who, PT_TGID);
+		break;
+	case PRIO_PGRP:
+		printpid(tcp, who, PT_PGID);
+		break;
+	default:
+		tprintf("%d", who);
+		break;
+	}
+}
+
 SYS_FUNC(getpriority)
 {
 	printxval(priorities, tcp->u_arg[0], "PRIO_???");
-	tprintf(", %d", (int) tcp->u_arg[1]);
+	tprints(", ");
+	priority_print_who(tcp, tcp->u_arg[0], tcp->u_arg[1]);
 
 	return RVAL_DECODED;
 }
@@ -190,7 +209,9 @@ SYS_FUNC(getpriority)
 SYS_FUNC(setpriority)
 {
 	printxval(priorities, tcp->u_arg[0], "PRIO_???");
-	tprintf(", %d, %d", (int) tcp->u_arg[1], (int) tcp->u_arg[2]);
+	tprints(", ");
+	priority_print_who(tcp, tcp->u_arg[0], tcp->u_arg[1]);
+	tprintf(", %d", (int) tcp->u_arg[2]);
 
 	return RVAL_DECODED;
 }
diff --git a/sched.c b/sched.c
index 788ef39b..ff427e48 100644
--- a/sched.c
+++ b/sched.c
@@ -21,7 +21,7 @@
 SYS_FUNC(sched_getscheduler)
 {
 	if (entering(tcp)) {
-		tprintf("%d", (int) tcp->u_arg[0]);
+		printpid(tcp, tcp->u_arg[0], PT_TGID);
 	} else if (!syserror(tcp)) {
 		tcp->auxstr = xlookup(schedulers, (kernel_ulong_t) tcp->u_rval);
 		return RVAL_STR;
@@ -31,7 +31,8 @@ SYS_FUNC(sched_getscheduler)
 
 SYS_FUNC(sched_setscheduler)
 {
-	tprintf("%d, ", (int) tcp->u_arg[0]);
+	printpid(tcp, tcp->u_arg[0], PT_TGID);
+	tprints(", ");
 	printxval(schedulers, tcp->u_arg[1], "SCHED_???");
 	tprints(", ");
 	printnum_int(tcp, tcp->u_arg[2], "%d");
@@ -41,16 +42,19 @@ SYS_FUNC(sched_setscheduler)
 
 SYS_FUNC(sched_getparam)
 {
-	if (entering(tcp))
-		tprintf("%d, ", (int) tcp->u_arg[0]);
-	else
+	if (entering(tcp)) {
+		printpid(tcp, tcp->u_arg[0], PT_TGID);
+		tprints(", ");
+	} else {
 		printnum_int(tcp, tcp->u_arg[1], "%d");
+	}
 	return 0;
 }
 
 SYS_FUNC(sched_setparam)
 {
-	tprintf("%d, ", (int) tcp->u_arg[0]);
+	printpid(tcp, tcp->u_arg[0], PT_TGID);
+	tprints(", ");
 	printnum_int(tcp, tcp->u_arg[1], "%d");
 
 	return RVAL_DECODED;
@@ -68,7 +72,8 @@ do_sched_rr_get_interval(struct tcb *const tcp,
 			 const print_obj_by_addr_fn print_ts)
 {
 	if (entering(tcp)) {
-		tprintf("%d, ", (int) tcp->u_arg[0]);
+		printpid(tcp, tcp->u_arg[0], PT_TGID);
+		tprints(", ");
 	} else {
 		if (syserror(tcp))
 			printaddr(tcp->u_arg[1]);
@@ -160,7 +165,8 @@ end:
 SYS_FUNC(sched_setattr)
 {
 	if (entering(tcp)) {
-		tprintf("%d, ", (int) tcp->u_arg[0]);
+		printpid(tcp, tcp->u_arg[0], PT_TGID);
+		tprints(", ");
 		print_sched_attr(tcp, tcp->u_arg[1], 0);
 	} else {
 		struct sched_attr attr;
@@ -179,7 +185,8 @@ SYS_FUNC(sched_setattr)
 SYS_FUNC(sched_getattr)
 {
 	if (entering(tcp)) {
-		tprintf("%d, ", (int) tcp->u_arg[0]);
+		printpid(tcp, tcp->u_arg[0], PT_TGID);
+		tprints(", ");
 	} else {
 		const unsigned int size = tcp->u_arg[2];
 
diff --git a/signal.c b/signal.c
index d5d59105..49b4ebd5 100644
--- a/signal.c
+++ b/signal.c
@@ -439,7 +439,8 @@ SYS_FUNC(sigprocmask)
 SYS_FUNC(kill)
 {
 	/* pid */
-	tprintf("%d, ", (int) tcp->u_arg[0]);
+	printpid_tgid_pgid(tcp, tcp->u_arg[0]);
+	tprints(", ");
 	/* signal */
 	printsignal(tcp->u_arg[1]);
 
@@ -448,7 +449,7 @@ SYS_FUNC(kill)
 
 SYS_FUNC(tkill)
 {
-	tprintf("%d", (int) tcp->u_arg[0]);
+	printpid(tcp, tcp->u_arg[0], PT_TID);
 	tprints(", ");
 	printsignal(tcp->u_arg[1]);
 
@@ -457,8 +458,12 @@ SYS_FUNC(tkill)
 
 SYS_FUNC(tgkill)
 {
-	/* tgid, tid */
-	tprintf("%d, %d, ", (int) tcp->u_arg[0], (int) tcp->u_arg[1]);
+	/* tgid */
+	printpid(tcp, tcp->u_arg[0], PT_TGID);
+	tprints(", ");
+	/* tid */
+	printpid(tcp, tcp->u_arg[1], PT_TID);
+	tprints(", ");
 	/* signal */
 	printsignal(tcp->u_arg[2]);
 
@@ -624,7 +629,8 @@ print_sigqueueinfo(struct tcb *const tcp, const int sig,
 
 SYS_FUNC(rt_sigqueueinfo)
 {
-	tprintf("%d, ", (int) tcp->u_arg[0]);
+	printpid(tcp, tcp->u_arg[0], PT_TGID);
+	tprints(", ");
 	print_sigqueueinfo(tcp, tcp->u_arg[1], tcp->u_arg[2]);
 
 	return RVAL_DECODED;
@@ -632,7 +638,10 @@ SYS_FUNC(rt_sigqueueinfo)
 
 SYS_FUNC(rt_tgsigqueueinfo)
 {
-	tprintf("%d, %d, ", (int) tcp->u_arg[0], (int) tcp->u_arg[1]);
+	printpid(tcp, tcp->u_arg[0], PT_TGID);
+	tprints(", ");
+	printpid(tcp, tcp->u_arg[1], PT_TID);
+	tprints(", ");
 	print_sigqueueinfo(tcp, tcp->u_arg[2], tcp->u_arg[3]);
 
 	return RVAL_DECODED;
diff --git a/sockaddr.c b/sockaddr.c
index b0046331..fb8887c2 100644
--- a/sockaddr.c
+++ b/sockaddr.c
@@ -416,7 +416,7 @@ print_sockaddr_data_nl(struct tcb *tcp, const void *const buf, const int addrlen
 {
 	const struct sockaddr_nl *const sa_nl = buf;
 
-	PRINT_FIELD_D("", *sa_nl, nl_pid);
+	PRINT_FIELD_TGID("", *sa_nl, nl_pid, tcp);
 	PRINT_FIELD_0X(", ", *sa_nl, nl_groups);
 }
 
diff --git a/tests/kcmp.c b/tests/kcmp.c
index a46da0ed..dc5ba9a4 100644
--- a/tests/kcmp.c
+++ b/tests/kcmp.c
@@ -64,7 +64,26 @@ static const char zero_path[] = "/dev/zero";
 static void
 printpidfd(const char *prefix, pid_t pid, unsigned fd)
 {
-	printf("%s%d", prefix, fd);
+	const char *path = NULL;
+
+# if VERBOSE_FD
+	if (pid == getpid()) {
+		switch (fd)
+		{
+		case NULL_FD:
+			path = null_path;
+			break;
+		case ZERO_FD:
+			path = zero_path;
+			break;
+		}
+	}
+# endif
+
+	if (path)
+		printf("%s%d<%s>", prefix, fd, path);
+	else
+		printf("%s%d", prefix, fd);
 }
 
 /*
@@ -179,7 +198,7 @@ main(void)
 	/* KCMP_FILE is the only type which has additional args */
 	do_kcmp(3141592653U, 2718281828U, ARG_STR(KCMP_FILE), bogus_idx1,
 		bogus_idx2);
-	do_kcmp(-1, -1, ARG_STR(KCMP_FILE), NULL_FD, ZERO_FD);
+	do_kcmp(getpid(), getpid(), ARG_STR(KCMP_FILE), NULL_FD, ZERO_FD);
 
 	/* Types without additional args */
 	do_kcmp(-1, -1, ARG_STR(KCMP_VM), bogus_idx1, bogus_idx2);
@@ -198,7 +217,7 @@ main(void)
 	for (i = 0; i < ARRAY_SIZE(slot_data); i++) {
 		memcpy(slot, slot_data + i, sizeof(*slot));
 
-		do_kcmp(getpid(), getppid(), ARG_STR(KCMP_EPOLL_TFD), NULL_FD,
+		do_kcmp(getpid(), -1, ARG_STR(KCMP_EPOLL_TFD), NULL_FD,
 			(uintptr_t) slot, 1);
 	}
 
diff --git a/util.c b/util.c
index 286c6903..2568021e 100644
--- a/util.c
+++ b/util.c
@@ -392,6 +392,18 @@ printnum_fd(struct tcb *const tcp, const kernel_ulong_t addr)
 	return true;
 }
 
+bool
+printnum_pid(struct tcb *const tcp, const kernel_ulong_t addr, enum pid_type type)
+{
+	int pid;
+	if (umove_or_printaddr(tcp, addr, &pid))
+		return false;
+	tprints("[");
+	printpid(tcp, pid, type);
+	tprints("]");
+	return true;
+}
+
 /**
  * Prints time to a (static internal) buffer and returns pointer to it.
  * Returns NULL if the provided time specification is not correct.
@@ -616,7 +628,7 @@ void
 printfd_pid(struct tcb *tcp, pid_t pid, int fd)
 {
 	char path[PATH_MAX + 1];
-	if (!number_set_array_is_empty(decode_fd_set, 0)
+	if (pid > 0 && !number_set_array_is_empty(decode_fd_set, 0)
 	    && getfdpath_pid(pid, fd, path, sizeof(path)) >= 0) {
 		tprintf("%d<", (int) fd);
 		if (is_number_in_set(DECODE_FD_SOCKET, decode_fd_set) &&
@@ -641,12 +653,8 @@ printed:
 void
 printfd_pid_tracee_ns(struct tcb *tcp, pid_t pid, int fd)
 {
-	/*
-	 * TODO: We want to have the same formatting as printfd here,
-	 *       but we should figure out first which process in strace's
-	 *       PID NS is referred to by pid in tracee's PID NS.
-	 */
-	tprintf("%d", fd);
+	int strace_pid = translate_pid(tcp, pid, PT_TGID, NULL);
+	printfd_pid(tcp, strace_pid, fd);
 }
 
 /*
diff --git a/wait.c b/wait.c
index 2b9f9807..177427c8 100644
--- a/wait.c
+++ b/wait.c
@@ -80,14 +80,8 @@ printwaitn(struct tcb *const tcp,
 	   void (*const print_rusage)(struct tcb *, kernel_ulong_t))
 {
 	if (entering(tcp)) {
-		/* On Linux, kernel-side pid_t is typedef'ed to int
-		 * on all arches. Also, glibc-2.8 truncates wait3 and wait4
-		 * pid argument to int on 64bit arches, producing,
-		 * for example, wait4(4294967295, ...) instead of -1
-		 * in strace. We have to use int here, not long.
-		 */
-		int pid = tcp->u_arg[0];
-		tprintf("%d, ", pid);
+		printpid_tgid_pgid(tcp, tcp->u_arg[0]);
+		tprintf(", ");
 	} else {
 		int status;
 
@@ -108,7 +102,7 @@ printwaitn(struct tcb *const tcp,
 				printaddr(tcp->u_arg[3]);
 		}
 	}
-	return 0;
+	return RVAL_TGID;
 }
 
 SYS_FUNC(waitpid)
@@ -134,10 +128,28 @@ SYS_FUNC(osf_wait4)
 
 SYS_FUNC(waitid)
 {
+	unsigned int idtype = (unsigned int) tcp->u_arg[0];
+	int id = tcp->u_arg[1];
+
 	if (entering(tcp)) {
-		printxval(waitid_types, tcp->u_arg[0], "P_???");
-		int pid = tcp->u_arg[1];
-		tprintf(", %d, ", pid);
+		printxval(waitid_types, idtype, "P_???");
+		tprints(", ");
+		switch (idtype)
+		{
+		case P_PID:
+			printpid(tcp, id, PT_TGID);
+			break;
+		case P_PIDFD:
+			printfd(tcp, id);
+			break;
+		case P_PGID:
+			printpid(tcp, id, PT_PGID);
+			break;
+		default:
+			tprintf("%d", id);
+			break;
+		}
+		tprints(", ");
 	} else {
 		/* siginfo */
 		printsiginfo_at(tcp, tcp->u_arg[2]);
-- 
2.27.0


From uzonyi.akos at gmail.com  Sun Aug  9 14:13:05 2020
From: uzonyi.akos at gmail.com (=?UTF-8?q?=C3=81kos=20Uzonyi?=)
Date: Sun,  9 Aug 2020 16:13:05 +0200
Subject: [PATCH v8 4/5] Implement testing framework for pidns
In-Reply-To: <20200809141306.477539-1-uzonyi.akos@gmail.com>
References: <20200809141306.477539-1-uzonyi.akos@gmail.com>
Message-ID: <20200809141306.477539-5-uzonyi.akos@gmail.com>

* tests/pidns.c: New file.
* tests/pidns.h: New file.
* tests/Makefile.am (libtests_a_SOURCES): Add pidns.c, pidns.h.
* tests/init.sh (test_pidns, test_pidns_run_strace): New functions.
---
 tests/Makefile.am |   2 +
 tests/init.sh     |  31 +++++++
 tests/pidns.c     | 214 ++++++++++++++++++++++++++++++++++++++++++++++
 tests/pidns.h     |  56 ++++++++++++
 4 files changed, 303 insertions(+)
 create mode 100644 tests/pidns.c
 create mode 100644 tests/pidns.h

diff --git a/tests/Makefile.am b/tests/Makefile.am
index 28d95e39..7a583a3a 100644
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@@ -44,6 +44,8 @@ libtests_a_SOURCES = \
 	libsocketcall.c \
 	lock_file.c \
 	overflowuid.c \
+	pidns.c \
+	pidns.h \
 	pipe_maxfd.c \
 	print_quoted_string.c \
 	print_time.c \
diff --git a/tests/init.sh b/tests/init.sh
index d78e697b..7325fa4a 100644
--- a/tests/init.sh
+++ b/tests/init.sh
@@ -387,6 +387,37 @@ test_prog_set()
 	test_pure_prog_set "$@" < "$srcdir/$NAME.in"
 }
 
+test_pidns_run_strace()
+{
+	local parent_pid
+
+	check_prog tail
+	check_prog cut
+	check_prog grep
+
+	run_prog > /dev/null
+	run_strace --pidns-translation -f $@ $args > "$EXP"
+
+	# filter out logs made by the parent or init process of the pidns test
+	parent_pid="$(tail -n 2 $LOG | head -n 1 | cut -d' ' -f1)"
+	init_pid="$(tail -n 1 $LOG | cut -d' ' -f1)"
+	grep -E -v "^($parent_pid|$init_pid) " "$LOG" > "$OUT"
+	match_diff "$OUT" "$EXP"
+}
+
+test_pidns()
+{
+	# ioctl(NS_GET_PARENT) is added in Linux 4.9
+	require_min_kernel_version_or_skip 4.9
+	check_prog unshare
+
+	test_pidns_run_strace "$@"
+
+	# test PID translation when /proc is mounted from an other namespace
+	STRACE="unshare -Urpf $STRACE"
+	test_pidns_run_strace "$@"
+}
+
 check_prog cat
 check_prog rm
 
diff --git a/tests/pidns.c b/tests/pidns.c
new file mode 100644
index 00000000..f54af340
--- /dev/null
+++ b/tests/pidns.c
@@ -0,0 +1,214 @@
+/*
+ * Testing framework for PID namespace translation
+ *
+ * Copyright (c) 2020 ?kos Uzonyi <uzonyi.akos at gmail.com>
+ * All rights reserved.
+ *
+ * SPDX-License-Identifier: LGPL-2.1-or-later
+ */
+#include "tests.h"
+#include "pidns.h"
+#include "nsfs.h"
+
+#include <errno.h>
+#include <stdio.h>
+#include <string.h>
+#include <sys/types.h>
+#include <signal.h>
+#include <stdlib.h>
+#include <sched.h>
+#include <unistd.h>
+#include <sys/wait.h>
+#include <linux/sched.h>
+#include <fcntl.h>
+#include <sys/ioctl.h>
+
+static bool pidns_translation = false;
+static bool pidns_unshared = false;
+
+/* Our PIDs in strace's namespace */
+static pid_t pidns_strace_ids[PT_COUNT];
+
+void
+pidns_print_leader(void)
+{
+	if (pidns_translation)
+		printf("%-5d ", pidns_strace_ids[PT_TID]);
+}
+
+const char *
+pidns_pid2str(enum pid_type type)
+{
+	static const char format[] = " /* %d in strace's PID NS */";
+	static char buf[PT_COUNT][sizeof(format) + sizeof(int) * 3];
+
+	if (type < 0 || type >= PT_COUNT)
+		return "";
+
+	if (!pidns_unshared || !pidns_strace_ids[type])
+		return "";
+
+	snprintf(buf[type], sizeof(buf[type]), format, pidns_strace_ids[type]);
+	return buf[type];
+}
+
+/**
+ * This function is like fork, but does a few more things. It sets up the
+ * child's PGID and SID according to the parameters. Also it fills the
+ * pidns_strace_ids array in the child's memory with the PIDs of the child in
+ * parent's PID namespace. In the parent it waits for the child to terminate
+ * (but leaves the zombie to use it later as a process group). If the child
+ * terminates with nonzero exit status, the test is failed.
+ *
+ * @param pgid     The process group the child should be moved to. It's expected
+ *                 to be a PID of a zombie process (will be reaped). If
+ *                 negative, leave the child in the process group of the parent.
+ *                 If 0, move the process to its own process group.
+ * @param new_sid  Wheather child should be moved to a new session.
+ */
+static pid_t
+pidns_fork(pid_t pgid, bool new_sid)
+{
+	int strace_ids_pipe[2];
+	if (pipe(strace_ids_pipe) < 0)
+		perror_msg_and_fail("pipe");
+
+	fflush(stdout);
+	pid_t pid = fork();
+	if (pid < 0)
+		perror_msg_and_fail("fork");
+
+	if (!pid) {
+		close(strace_ids_pipe[1]);
+		if (read(strace_ids_pipe[0], pidns_strace_ids,
+		    sizeof(pidns_strace_ids)) < 0)
+			perror_msg_and_fail("read");
+		close(strace_ids_pipe[0]);
+
+		if (pidns_strace_ids[PT_SID])
+			setsid();
+
+		return 0;
+	}
+
+	pidns_strace_ids[PT_TID] = pid;
+	pidns_strace_ids[PT_TGID] = pid;
+	pidns_strace_ids[PT_PGID] = 0;
+	pidns_strace_ids[PT_SID] = 0;
+
+	if (!pgid)
+		pgid = pid;
+
+	if (pgid > 0) {
+		if (setpgid(pid, pgid) < 0)
+			perror_msg_and_fail("setpgid");
+
+		pidns_strace_ids[PT_PGID] = pgid;
+	}
+
+	/* Reap group leader to test PGID decoding */
+	if (pgid > 0 && pgid != pid) {
+		int ret = waitpid(pgid, NULL, WNOHANG);
+		if (ret < 0)
+			perror_msg_and_fail("wait");
+		if (!ret)
+			error_msg_and_fail("could not reap group leader");
+	}
+
+	if (new_sid) {
+		pidns_strace_ids[PT_SID] = pid;
+		pidns_strace_ids[PT_PGID] = pid;
+	}
+
+	if (write(strace_ids_pipe[1], pidns_strace_ids,
+	    sizeof(pidns_strace_ids)) < 0)
+		perror_msg_and_fail("write");
+	close(strace_ids_pipe[0]);
+	close(strace_ids_pipe[1]);
+
+	/* WNOWAIT: leave the zombie, to be able to use it as a process group */
+	siginfo_t siginfo;
+	if (waitid(P_PID, pid, &siginfo, WEXITED | WNOWAIT) < 0)
+		perror_msg_and_fail("wait");
+	if (siginfo.si_code != CLD_EXITED || siginfo.si_status)
+		error_msg_and_fail("child terminated with nonzero exit status");
+
+	return pid;
+}
+
+static void
+create_init_process(void)
+{
+	int child_pipe[2];
+	if (pipe(child_pipe) < 0)
+		perror_msg_and_fail("pipe");
+
+	pid_t pid = fork();
+	if (pid < 0)
+		perror_msg_and_fail("fork");
+
+	if (!pid) {
+		close(child_pipe[1]);
+		_exit(read(child_pipe[0], &child_pipe[1], sizeof(int)) == 0);
+	}
+
+	close(child_pipe[0]);
+}
+
+void
+check_ns_ioctl(void)
+{
+	int fd = open("/proc/self/ns/pid", O_RDONLY);
+	if (fd < 0)
+		perror_msg_and_fail("opening /proc/self/ns/pid");
+
+	int userns_fd = ioctl(fd, NS_GET_USERNS);
+	if (userns_fd < 0) {
+		if (errno == ENOTTY)
+			error_msg_and_skip("NS_* ioctl commands are not "
+			                   "supported by the kernel");
+		else
+			perror_msg_and_fail("ioctl(NS_GET_USERNS)");
+	}
+
+	close(userns_fd);
+	close(fd);
+}
+
+void
+pidns_test_init(void)
+{
+	pidns_translation = true;
+
+	check_ns_ioctl();
+
+	if (!pidns_fork(-1, false))
+		return;
+
+	/* Unshare user namespace too, so we do not need to be root */
+	if (unshare(CLONE_NEWUSER | CLONE_NEWPID) < 0) {
+		if (errno == EPERM)
+			perror_msg_and_skip("unshare");
+
+		perror_msg_and_fail("unshare");
+	}
+
+	pidns_unshared = true;
+
+	create_init_process();
+
+	if (!pidns_fork(-1, false))
+		return;
+
+	if (!pidns_fork(-1, true))
+		return;
+
+	pid_t pgid;
+	if (!(pgid = pidns_fork(0, false)))
+		return;
+
+	if (!pidns_fork(pgid, false))
+		return;
+
+	exit(0);
+}
diff --git a/tests/pidns.h b/tests/pidns.h
new file mode 100644
index 00000000..76963eb3
--- /dev/null
+++ b/tests/pidns.h
@@ -0,0 +1,56 @@
+/*
+ * Test PID namespace translation
+ *
+ * Copyright (c) 2020 ?kos Uzonyi <uzonyi.akos at gmail.com>
+ * All rights reserved.
+ *
+ * SPDX-License-Identifier: LGPL-2.1-or-later
+ */
+#ifndef STRACE_PIDNS_H
+#define STRACE_PIDNS_H
+
+#ifdef PIDNS_TRANSLATION
+# define PIDNS_TEST_INIT pidns_test_init()
+#else
+# define PIDNS_TEST_INIT
+#endif
+
+#include <sys/types.h>
+
+enum pid_type {
+	PT_TID,
+	PT_TGID,
+	PT_PGID,
+	PT_SID,
+
+	PT_COUNT,
+	PT_NONE = -1
+};
+
+/* Prints leader (process tid) if pidns_test_init was called */
+void pidns_print_leader(void);
+
+/*
+ * Returns a static buffer containing the translation string of our PID.
+ */
+const char *pidns_pid2str(enum pid_type type);
+
+/**
+ * Skips the test if NS_* ioctl commands are not supported by the kernel.
+ */
+void check_ns_ioctl(void);
+
+/**
+ * Init pidns testing.
+ *
+ * Should be called at the beginning of the test's main function
+ *
+ * This function calls fork a couple of times, and returns in the child
+ * processes. These child processes are in a new PID namespace with different
+ * PID configurations (group leader, session leader, ...). If any child
+ * terminates with nonzero exit status the test is failed. Otherwise the test is
+ * succesful, and the parent process exits with 0.
+ */
+void pidns_test_init(void);
+
+#endif
\ No newline at end of file
-- 
2.27.0


From uzonyi.akos at gmail.com  Sun Aug  9 14:13:06 2020
From: uzonyi.akos at gmail.com (=?UTF-8?q?=C3=81kos=20Uzonyi?=)
Date: Sun,  9 Aug 2020 16:13:06 +0200
Subject: [PATCH v8 5/5] Add tests for PID namespace translation
In-Reply-To: <20200809141306.477539-1-uzonyi.akos@gmail.com>
References: <20200809141306.477539-1-uzonyi.akos@gmail.com>
Message-ID: <20200809141306.477539-6-uzonyi.akos@gmail.com>

* tests/.gitignore: Add new test executables.
* tests/Makefile.am (check_PROGRAMS): Add new test executables.
(DECODER_TESTS) Add new test files.
* tests/gen_tests.in: Add new tests.
* tests/fcntl--pidns-translation.c: New file.
* tests/fcntl64--pidns-translation.c: New file.
* tests/fork--pidns-translation.awk: New file.
* tests/fork--pidns-translation.c: New file.
* tests/fork--pidns-translation.test: New file.
* tests/getpgrp--pidns-translation.c: New file.
* tests/getpid--pidns-translation.c: New file.
* tests/getsid--pidns-translation.c: New file.
* tests/gettid--pidns-translation.c: New file.
* tests/gettid--pidns-translation.test: New file.
* tests/ioctl_block--pidns-translation.c: New file.
* tests/ioctl_block--pidns-translation.test: New file.
* tests/ioprio--pidns-translation.c: New file.
* tests/kill--pidns-translation.c: New file.
* tests/migrate_pages--pidns-translation.c: New file.
* tests/move_pages--pidns-translation.c: New file.
* tests/net-sockaddr--pidns-translation.c: New file.
* tests/netlink_audit--pidns-translation.c: New file.
* tests/netlink_audit--pidns-translation.test: New file.
* tests/pidfd_open--pidns-translation.c: New file.
* tests/pidfd_send_signal--pidns-translation.c: New file.
* tests/prlimit64--pidns-translation.c: New file.
* tests/process_vm_readv--pidns-translation.c: New file.
* tests/process_vm_writev--pidns-translation.c: New file.
* tests/rt_sigqueueinfo--pidns-translation.c: New file.
* tests/rt_tgsigqueueinfo--pidns-translation.c: New file.
* tests/sched_xetaffinity--pidns-translation.c: New file.
* tests/sched_xetattr--pidns-translation.c: New file.
* tests/sched_xetparam--pidns-translation.c: New file.
* tests/sched_xetscheduler--pidns-translation.c: New file.
* tests/signal_receive--pidns-translation.c: New file.
* tests/so_peercred--pidns-translation.c: New file.
* tests/xet_robust_list--pidns-translation.c: New file.
* tests/xetpgid--pidns-translation.c: New file.
* tests/xetpriority--pidns-translation.c: New file.
* tests/fcntl-common.c: Print PID translation string after PIDs.
* tests/fcntl.c: Likewise.
* tests/fcntl64.c: Likewise.
* tests/getpgrp.c: Likewise.
* tests/getpid.c: Likewise.
* tests/getsid.c: Likewise.
* tests/gettid.c: Likewise.
* tests/ioctl_block.c: Likewise.
* tests/ioprio.c: Likewise.
* tests/kcmp.c: Likewise.
* tests/kill.c: Likewise.
* tests/migrate_pages.c: Likewise.
* tests/move_pages.c: Likewise.
* tests/net-sockaddr.c: Likewise.
* tests/netlink_audit.c: Likewise.
* tests/pidfd_open.c: Likewise.
* tests/pidfd_send_signal.c: Likewise.
* tests/prlimit64.c: Likewise.
* tests/process_vm_readv_writev.c: Likewise.
* tests/rt_sigqueueinfo.c: Likewise.
* tests/rt_tgsigqueueinfo.c: Likewise.
* tests/sched_xetaffinity.c: Likewise.
* tests/sched_xetattr.c: Likewise.
* tests/sched_xetparam.c: Likewise.
* tests/sched_xetscheduler.c: Likewise.
* tests/signal_receive.c: Likewise.
* tests/so_peercred.c: Likewise.
* tests/xet_robust_list.c: Likewise.
* tests/xetpgid.c: Likewise.
* tests/xetpriority.c: Likewise.
---
 tests/.gitignore                              | 31 +++++++
 tests/Makefile.am                             | 36 ++++++++
 tests/fcntl--pidns-translation.c              |  2 +
 tests/fcntl-common.c                          | 82 ++++++++++++++-----
 tests/fcntl.c                                 |  1 +
 tests/fcntl64--pidns-translation.c            |  2 +
 tests/fcntl64.c                               |  3 +
 tests/fork--pidns-translation.awk             | 15 ++++
 tests/fork--pidns-translation.c               | 69 ++++++++++++++++
 tests/fork--pidns-translation.test            | 16 ++++
 tests/gen_tests.in                            | 29 ++++++-
 tests/getpgrp--pidns-translation.c            |  2 +
 tests/getpgrp.c                               |  8 +-
 tests/getpid--pidns-translation.c             |  2 +
 tests/getpid.c                                |  8 +-
 tests/getsid--pidns-translation.c             |  2 +
 tests/getsid.c                                |  9 +-
 tests/gettid--pidns-translation.c             |  2 +
 tests/gettid--pidns-translation.test          | 20 +++++
 tests/gettid.c                                |  8 +-
 tests/ioctl_block--pidns-translation.c        |  2 +
 tests/ioctl_block--pidns-translation.test     | 24 ++++++
 tests/ioctl_block.c                           | 24 +++++-
 tests/ioprio--pidns-translation.c             |  2 +
 tests/ioprio.c                                | 54 ++++++++----
 tests/kcmp-y--pidns-translation.c             |  2 +
 tests/kcmp.c                                  | 11 ++-
 tests/kill--pidns-translation.c               |  2 +
 tests/kill.c                                  | 12 ++-
 tests/migrate_pages--pidns-translation.c      |  2 +
 tests/migrate_pages.c                         | 17 +++-
 tests/move_pages--pidns-translation.c         |  2 +
 tests/move_pages.c                            | 51 +++++++-----
 tests/net-sockaddr--pidns-translation.c       |  2 +
 tests/net-sockaddr.c                          | 66 +++++++++++++--
 tests/netlink_audit--pidns-translation.c      |  2 +
 tests/netlink_audit--pidns-translation.test   | 13 +++
 tests/netlink_audit.c                         | 11 ++-
 tests/pidfd_open--pidns-translation.c         |  2 +
 tests/pidfd_open.c                            | 21 +++--
 tests/pidfd_send_signal--pidns-translation.c  |  2 +
 tests/pidfd_send_signal.c                     | 13 ++-
 tests/prlimit64--pidns-translation.c          |  2 +
 tests/prlimit64.c                             | 17 +++-
 tests/process_vm_readv--pidns-translation.c   |  2 +
 tests/process_vm_readv_writev.c               | 27 +++---
 tests/process_vm_writev--pidns-translation.c  |  2 +
 tests/rt_sigqueueinfo--pidns-translation.c    |  2 +
 tests/rt_sigqueueinfo.c                       | 15 +++-
 tests/rt_tgsigqueueinfo--pidns-translation.c  |  2 +
 tests/rt_tgsigqueueinfo.c                     | 26 ++++--
 tests/sched_xetaffinity--pidns-translation.c  |  2 +
 tests/sched_xetaffinity.c                     | 31 ++++---
 tests/sched_xetattr--pidns-translation.c      |  2 +
 tests/sched_xetattr.c                         | 47 ++++++++++-
 tests/sched_xetparam--pidns-translation.c     |  2 +
 tests/sched_xetparam.c                        | 20 +++--
 tests/sched_xetscheduler--pidns-translation.c |  2 +
 tests/sched_xetscheduler.c                    | 44 ++++++----
 tests/signal_receive--pidns-translation.c     |  2 +
 tests/signal_receive.c                        | 22 +++--
 tests/so_peercred--pidns-translation.c        |  2 +
 tests/so_peercred.c                           | 22 +++++
 tests/xet_robust_list--pidns-translation.c    |  2 +
 tests/xet_robust_list.c                       | 18 +++-
 tests/xetpgid--pidns-translation.c            |  2 +
 tests/xetpgid.c                               | 21 +++--
 tests/xetpriority--pidns-translation.c        |  2 +
 tests/xetpriority.c                           | 20 ++++-
 69 files changed, 874 insertions(+), 168 deletions(-)
 create mode 100644 tests/fcntl--pidns-translation.c
 create mode 100644 tests/fcntl64--pidns-translation.c
 create mode 100644 tests/fork--pidns-translation.awk
 create mode 100644 tests/fork--pidns-translation.c
 create mode 100755 tests/fork--pidns-translation.test
 create mode 100644 tests/getpgrp--pidns-translation.c
 create mode 100644 tests/getpid--pidns-translation.c
 create mode 100644 tests/getsid--pidns-translation.c
 create mode 100644 tests/gettid--pidns-translation.c
 create mode 100755 tests/gettid--pidns-translation.test
 create mode 100644 tests/ioctl_block--pidns-translation.c
 create mode 100755 tests/ioctl_block--pidns-translation.test
 create mode 100644 tests/ioprio--pidns-translation.c
 create mode 100644 tests/kcmp-y--pidns-translation.c
 create mode 100644 tests/kill--pidns-translation.c
 create mode 100644 tests/migrate_pages--pidns-translation.c
 create mode 100644 tests/move_pages--pidns-translation.c
 create mode 100644 tests/net-sockaddr--pidns-translation.c
 create mode 100644 tests/netlink_audit--pidns-translation.c
 create mode 100755 tests/netlink_audit--pidns-translation.test
 create mode 100644 tests/pidfd_open--pidns-translation.c
 create mode 100644 tests/pidfd_send_signal--pidns-translation.c
 create mode 100644 tests/prlimit64--pidns-translation.c
 create mode 100644 tests/process_vm_readv--pidns-translation.c
 create mode 100644 tests/process_vm_writev--pidns-translation.c
 create mode 100644 tests/rt_sigqueueinfo--pidns-translation.c
 create mode 100644 tests/rt_tgsigqueueinfo--pidns-translation.c
 create mode 100644 tests/sched_xetaffinity--pidns-translation.c
 create mode 100644 tests/sched_xetattr--pidns-translation.c
 create mode 100644 tests/sched_xetparam--pidns-translation.c
 create mode 100644 tests/sched_xetscheduler--pidns-translation.c
 create mode 100644 tests/signal_receive--pidns-translation.c
 create mode 100644 tests/so_peercred--pidns-translation.c
 create mode 100644 tests/xet_robust_list--pidns-translation.c
 create mode 100644 tests/xetpgid--pidns-translation.c
 create mode 100644 tests/xetpriority--pidns-translation.c

diff --git a/tests/.gitignore b/tests/.gitignore
index 0031d04d..4d1153fc 100644
--- a/tests/.gitignore
+++ b/tests/.gitignore
@@ -116,7 +116,9 @@ fchown
 fchown32
 fchownat
 fcntl
+fcntl--pidns-translation
 fcntl64
+fcntl64--pidns-translation
 fdatasync
 fflush
 file_handle
@@ -126,6 +128,7 @@ filter-unavailable
 finit_module
 flock
 fork-f
+fork--pidns-translation
 fsconfig
 fsconfig-P
 fsmount
@@ -168,7 +171,9 @@ getgroups
 getgroups32
 getpeername
 getpgrp
+getpgrp--pidns-translation
 getpid
+getpid--pidns-translation
 getppid
 getrandom
 getresgid
@@ -178,8 +183,10 @@ getresuid32
 getrlimit
 getrusage
 getsid
+getsid--pidns-translation
 getsockname
 gettid
+gettid--pidns-translation
 getuid
 getuid32
 getxgid
@@ -200,6 +207,7 @@ io_uring_register
 io_uring_setup
 ioctl
 ioctl_block
+ioctl_block--pidns-translation
 ioctl_dm
 ioctl_dm-v
 ioctl_evdev
@@ -275,6 +283,7 @@ ioctl_watchdog
 ioperm
 iopl
 ioprio
+ioprio--pidns-translation
 ioprio-Xabbrev
 ioprio-Xraw
 ioprio-Xverbose
@@ -299,6 +308,7 @@ ipc_shm-Xverbose
 is_linux_mips_n64
 kcmp
 kcmp-y
+kcmp-y--pidns-translation
 kern_features
 kernel_version
 kernel_version-Xabbrev
@@ -311,6 +321,7 @@ keyctl-Xabbrev
 keyctl-Xraw
 keyctl-Xverbose
 kill
+kill--pidns-translation
 kill_child
 ksysent
 ksysent.h
@@ -340,6 +351,7 @@ memfd_create-Xabbrev
 memfd_create-Xraw
 memfd_create-Xverbose
 migrate_pages
+migrate_pages--pidns-translation
 mincore
 mkdir
 mkdirat
@@ -371,6 +383,7 @@ move_pages
 move_pages-Xabbrev
 move_pages-Xraw
 move_pages-Xverbose
+move_pages--pidns-translation
 mq
 mq_sendrecv
 mq_sendrecv-read
@@ -391,6 +404,7 @@ net-packet_mreq-Xabbrev
 net-packet_mreq-Xraw
 net-packet_mreq-Xverbose
 net-sockaddr
+net-sockaddr--pidns-translation
 net-tpacket_req
 net-tpacket_stats
 net-tpacket_stats-success
@@ -400,6 +414,7 @@ net-yy-inet6
 net-yy-netlink
 net-yy-unix
 netlink_audit
+netlink_audit--pidns-translation
 netlink_crypto
 netlink_generic
 netlink_inet_diag
@@ -507,7 +522,9 @@ pidfd_open--decode-fd-socket
 pidfd_open-P
 pidfd_open-y
 pidfd_open-yy
+pidfd_open--pidns-translation
 pidfd_send_signal
+pidfd_send_signal--pidns-translation
 pipe
 pipe2
 pkey_alloc
@@ -546,8 +563,11 @@ printstrn-umoven
 printstrn-umoven-peekdata
 printstrn-umoven-undumpable
 prlimit64
+prlimit64--pidns-translation
 process_vm_readv
+process_vm_readv--pidns-translation
 process_vm_writev
+process_vm_writev--pidns-translation
 pselect6
 ptrace
 ptrace_syscall_info
@@ -597,10 +617,12 @@ rt_sigaction
 rt_sigpending
 rt_sigprocmask
 rt_sigqueueinfo
+rt_sigqueueinfo--pidns-translation
 rt_sigreturn
 rt_sigsuspend
 rt_sigtimedwait
 rt_tgsigqueueinfo
+rt_tgsigqueueinfo--pidns-translation
 run_expect_termsig
 s390_guarded_storage
 s390_guarded_storage-v
@@ -611,9 +633,13 @@ s390_sthyi-v
 sched_get_priority_mxx
 sched_rr_get_interval
 sched_xetaffinity
+sched_xetaffinity--pidns-translation
 sched_xetattr
+sched_xetattr--pidns-translation
 sched_xetparam
+sched_xetparam--pidns-translation
 sched_xetscheduler
+sched_xetscheduler--pidns-translation
 sched_yield
 scm_rights
 scno.h
@@ -669,6 +695,7 @@ sigaltstack
 siginfo
 signal
 signal_receive
+signal_receive--pidns-translation
 signalfd4
 sigpending
 sigprocmask
@@ -681,6 +708,7 @@ so_peercred
 so_peercred-Xabbrev
 so_peercred-Xraw
 so_peercred-Xverbose
+so_peercred--pidns-translation
 sock_filter-v
 sock_filter-v-Xabbrev
 sock_filter-v-Xraw
@@ -783,9 +811,12 @@ waitpid
 xattr
 xattr-strings
 xet_robust_list
+xet_robust_list--pidns-translation
 xet_thread_area_x86
 xetitimer
 xetpgid
+xetpgid--pidns-translation
 xetpriority
+xetpriority--pidns-translation
 xettimeofday
 zeroargc
diff --git a/tests/Makefile.am b/tests/Makefile.am
index 7a583a3a..f2c5da83 100644
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@@ -109,17 +109,25 @@ check_PROGRAMS = $(PURE_EXECUTABLES) \
 	delay \
 	execve-v \
 	execveat-v \
+	fcntl--pidns-translation \
+	fcntl64--pidns-translation \
 	filter_seccomp-flag \
 	filter_seccomp-perf \
 	filter-unavailable \
 	fork-f \
+	fork--pidns-translation \
 	fsync-y \
 	get_process_reaper \
+	getpgrp--pidns-translation	\
 	getpid	\
+	getpid--pidns-translation	\
 	getppid	\
+	getsid--pidns-translation \
 	gettid \
+	gettid--pidns-translation \
 	inject-nf \
 	int_0x80 \
+	ioctl_block--pidns-translation \
 	ioctl_dm-v \
 	ioctl_evdev-success \
 	ioctl_evdev-success-Xabbrev \
@@ -150,18 +158,25 @@ check_PROGRAMS = $(PURE_EXECUTABLES) \
 	ioctl_v4l2-success-v-Xabbrev \
 	ioctl_v4l2-success-v-Xraw \
 	ioctl_v4l2-success-v-Xverbose \
+	ioprio--pidns-translation \
 	is_linux_mips_n64 \
+	kcmp-y--pidns-translation \
 	kill_child \
+	kill--pidns-translation \
 	ksysent \
 	list_sigaction_signum \
 	localtime \
 	looping_threads \
+	migrate_pages--pidns-translation \
 	mmsg-silent \
 	mmsg_name-v \
+	move_pages--pidns-translation \
 	msg_control-v \
 	net-accept-connect \
+	net-sockaddr--pidns-translation \
 	net-tpacket_stats-success \
 	nlattr_ifla_xdp-y \
+	netlink_audit--pidns-translation \
 	netlink_inet_diag \
 	netlink_netlink_diag \
 	netlink_unix_diag \
@@ -173,14 +188,19 @@ check_PROGRAMS = $(PURE_EXECUTABLES) \
 	pc \
 	perf_event_open_nonverbose \
 	perf_event_open_unabbrev \
+	pidfd_open--pidns-translation \
+	pidfd_send_signal--pidns-translation \
 	poll-P \
 	ppoll-P \
 	ppoll-v \
+	prlimit64--pidns-translation \
 	prctl-seccomp-filter-v \
 	prctl-seccomp-strict \
 	prctl-spec-inject \
 	print_maxfd \
 	print_ppid_tracerpid \
+	process_vm_readv--pidns-translation \
+	process_vm_writev--pidns-translation \
 	qual_fault \
 	qual_inject-error-signal \
 	qual_inject-retval \
@@ -194,7 +214,13 @@ check_PROGRAMS = $(PURE_EXECUTABLES) \
 	quotactl-xfs-v \
 	redirect-fds \
 	restart_syscall \
+	rt_sigqueueinfo--pidns-translation \
+	rt_tgsigqueueinfo--pidns-translation \
 	run_expect_termsig \
+	sched_xetaffinity--pidns-translation \
+	sched_xetattr--pidns-translation \
+	sched_xetparam--pidns-translation \
+	sched_xetscheduler--pidns-translation \
 	scm_rights \
 	seccomp-filter-v \
 	seccomp-strict \
@@ -204,12 +230,14 @@ check_PROGRAMS = $(PURE_EXECUTABLES) \
 	set_sigign \
 	setpgrp-exec \
 	signal_receive \
+	signal_receive--pidns-translation \
 	sleep \
 	stack-fcall \
 	stack-fcall-attach \
 	stack-fcall-mangled \
 	status-none-threads \
 	status-unfinished-threads \
+	so_peercred--pidns-translation \
 	syslog-success \
 	threads-execve \
 	threads-execve--quiet-thread-execve \
@@ -223,6 +251,9 @@ check_PROGRAMS = $(PURE_EXECUTABLES) \
 	vfork-f \
 	wait4-v \
 	waitid-v \
+	xetpgid--pidns-translation \
+	xetpriority--pidns-translation \
+	xet_robust_list--pidns-translation \
 	zeroargc \
 	# end of check_PROGRAMS
 
@@ -310,6 +341,7 @@ DECODER_TESTS = \
 	int_0x80.test \
 	inotify_init-y.test \
 	ioctl.test \
+	ioctl_block--pidns-translation.test \
 	ioctl_evdev-success.test \
 	ipc_msgbuf.test \
 	kern_features-fault.test \
@@ -381,12 +413,15 @@ MISC_TESTS = \
 	filtering_fd-syntax.test \
 	filtering_syscall-syntax.test \
 	first_exec_failure.test \
+	fork--pidns-translation.test \
 	get_regs.test \
+	gettid--pidns-translation.test \
 	inject-nf.test \
 	interactive_block.test \
 	kill_child.test \
 	localtime.test \
 	looping_threads.test \
+	netlink_audit--pidns-translation.test \
 	opipe.test \
 	options-syntax.test \
 	pc.test \
@@ -467,6 +502,7 @@ EXTRA_DIST = \
 	filter_seccomp.in \
 	filter_seccomp.sh \
 	filter-unavailable.expected \
+	fork--pidns-translation.awk \
 	fstatat.c \
 	fstatx.c \
 	gen_pure_executables.sh \
diff --git a/tests/fcntl--pidns-translation.c b/tests/fcntl--pidns-translation.c
new file mode 100644
index 00000000..e249424a
--- /dev/null
+++ b/tests/fcntl--pidns-translation.c
@@ -0,0 +1,2 @@
+#define PIDNS_TRANSLATION
+#include "fcntl.c"
diff --git a/tests/fcntl-common.c b/tests/fcntl-common.c
index 27694326..d9e29939 100644
--- a/tests/fcntl-common.c
+++ b/tests/fcntl-common.c
@@ -13,6 +13,8 @@
 #include <unistd.h>
 #include <assert.h>
 #include "flock.h"
+#include "pidns.h"
+#include "scno.h"
 
 #define FILE_LEN 4096
 
@@ -48,12 +50,14 @@ test_flock_einval(const int cmd, const char *name)
 	fl->l_len = (TYPEOF_FLOCK_OFF_T) 0xdefaced2cafef00dULL;
 
 	invoke_test_syscall(0, cmd, fl);
+	pidns_print_leader();
 	printf("%s(0, %s, {l_type=F_RDLCK, l_whence=SEEK_SET"
 	       ", l_start=%jd, l_len=%jd}) = %s\n", TEST_SYSCALL_STR, name,
 	       (intmax_t) fl->l_start, (intmax_t) fl->l_len, errstr);
 
 	void *const bad_addr = (void *) fl + 1;
 	invoke_test_syscall(0, cmd, bad_addr);
+	pidns_print_leader();
 	printf("%s(0, %s, %p) = %s\n",
 	       TEST_SYSCALL_STR, name, bad_addr, errstr);
 }
@@ -72,12 +76,14 @@ test_flock64_einval(const int cmd, const char *name)
 	fl->l_len = (TYPEOF_FLOCK_OFF_T) 0xdefaced2cafef00dULL;
 
 	invoke_test_syscall(0, cmd, fl);
+	pidns_print_leader();
 	printf("%s(0, %s, {l_type=F_RDLCK, l_whence=SEEK_SET"
 	       ", l_start=%jd, l_len=%jd}) = %s\n", TEST_SYSCALL_STR, name,
 	       (intmax_t) fl->l_start, (intmax_t) fl->l_len, errstr);
 
 	void *const bad_addr = (void *) fl + 1;
 	invoke_test_syscall(0, cmd, bad_addr);
+	pidns_print_leader();
 	printf("%s(0, %s, %p) = %s\n",
 	       TEST_SYSCALL_STR, name, bad_addr, errstr);
 }
@@ -94,6 +100,7 @@ test_flock(void)
 	fl->l_len = FILE_LEN;
 
 	long rc = invoke_test_syscall(0, F_SETLK, fl);
+	pidns_print_leader();
 	printf("%s(0, F_SETLK, {l_type=F_RDLCK, l_whence=SEEK_SET"
 	       ", l_start=0, l_len=%d}) = %s\n",
 	       TEST_SYSCALL_STR, FILE_LEN, errstr);
@@ -101,11 +108,13 @@ test_flock(void)
 		return;
 
 	invoke_test_syscall(0, F_GETLK, fl);
+	pidns_print_leader();
 	printf("%s(0, F_GETLK, {l_type=F_UNLCK, l_whence=SEEK_SET"
 	       ", l_start=0, l_len=%d, l_pid=0}) = 0\n",
 	       TEST_SYSCALL_STR, FILE_LEN);
 
 	invoke_test_syscall(0, F_SETLKW, fl);
+	pidns_print_leader();
 	printf("%s(0, F_SETLKW, {l_type=F_UNLCK, l_whence=SEEK_SET"
 	       ", l_start=0, l_len=%d}) = 0\n",
 	       TEST_SYSCALL_STR, FILE_LEN);
@@ -124,6 +133,7 @@ test_flock64_ofd(void)
 	fl->l_len = FILE_LEN;
 
 	long rc = invoke_test_syscall(0, F_OFD_SETLK, fl);
+	pidns_print_leader();
 	printf("%s(0, F_OFD_SETLK, {l_type=F_RDLCK, l_whence=SEEK_SET"
 	       ", l_start=0, l_len=%d}) = %s\n",
 	       TEST_SYSCALL_STR, FILE_LEN, errstr);
@@ -131,11 +141,13 @@ test_flock64_ofd(void)
 		return;
 
 	invoke_test_syscall(0, F_OFD_GETLK, fl);
+	pidns_print_leader();
 	printf("%s(0, F_OFD_GETLK, {l_type=F_UNLCK, l_whence=SEEK_SET"
 	       ", l_start=0, l_len=%d, l_pid=0}) = 0\n",
 	       TEST_SYSCALL_STR, FILE_LEN);
 
 	invoke_test_syscall(0, F_OFD_SETLKW, fl);
+	pidns_print_leader();
 	printf("%s(0, F_OFD_SETLKW, {l_type=F_UNLCK, l_whence=SEEK_SET"
 	       ", l_start=0, l_len=%d}) = 0\n",
 	       TEST_SYSCALL_STR, FILE_LEN);
@@ -167,18 +179,21 @@ test_flock64(void)
 static long
 test_f_owner_ex_type_pid(const int cmd, const char *const cmd_name,
 			 const int type, const char *const type_name,
-			 pid_t pid)
+			 enum pid_type pid_type, pid_t pid)
 {
 	TAIL_ALLOC_OBJECT_CONST_PTR(struct_kernel_f_owner_ex, fo);
 
 	fo->type = type;
 	fo->pid = pid;
 	long rc = invoke_test_syscall(0, cmd, fo);
-	printf("%s(0, %s, {type=%s, pid=%d}) = %s\n",
-	       TEST_SYSCALL_STR, cmd_name, type_name, fo->pid, errstr);
+	pidns_print_leader();
+	printf("%s(0, %s, {type=%s, pid=%d%s}) = %s\n",
+	       TEST_SYSCALL_STR, cmd_name, type_name,
+	       fo->pid, pidns_pid2str(pid_type), errstr);
 
 	void *bad_addr = (void *) fo + 1;
 	invoke_test_syscall(0, cmd, bad_addr);
+	pidns_print_leader();
 	printf("%s(0, %s, %p) = %s\n",
 	       TEST_SYSCALL_STR, cmd_name, bad_addr, errstr);
 
@@ -187,35 +202,39 @@ test_f_owner_ex_type_pid(const int cmd, const char *const cmd_name,
 
 static void
 test_f_owner_ex_umove_or_printaddr(const int type, const char *const type_name,
-				   pid_t pid)
+				   enum pid_type pid_type, pid_t pid)
 {
 	long rc = test_f_owner_ex_type_pid(ARG_STR(F_SETOWN_EX),
-					   type, type_name, pid);
+					   type, type_name, pid_type, pid);
 	if (!rc)
 		test_f_owner_ex_type_pid(ARG_STR(F_GETOWN_EX),
-					 type, type_name, pid);
+					 type, type_name, pid_type, pid);
 }
 
 static void
 test_f_owner_ex(void)
 {
-	static const struct {
+	struct {
 		int type;
 		const char *type_name;
-		pid_t pid[2];
+		enum pid_type pid_type;
+		pid_t pid;
 	} a[] = {
-		{ ARG_STR(F_OWNER_TID), { 1234567890, 20 } },
-		{ ARG_STR(F_OWNER_PID), { 1298126790, 30 } },
-		{ ARG_STR(F_OWNER_PGRP), { 1294567890, 40 } }
+		{ ARG_STR(F_OWNER_TID), PT_NONE, 1234567890 },
+		{ ARG_STR(F_OWNER_PID), PT_NONE, 1234567890 },
+		{ ARG_STR(F_OWNER_PGRP), PT_NONE, 1234567890 },
+		{ ARG_STR(F_OWNER_TID), PT_TID, 0 },
+		{ ARG_STR(F_OWNER_PID), PT_TGID, 0 },
+		{ ARG_STR(F_OWNER_PGRP), PT_PGID, 0 },
 	};
 
-	for (unsigned int i = 0; i < ARRAY_SIZE(a); i++) {
-		for (unsigned int j = 0; j < ARRAY_SIZE(a[0].pid); j++) {
-			test_f_owner_ex_umove_or_printaddr(a[i].type,
-							   a[i].type_name,
-							   a[i].pid[j]);
-		}
-	}
+	a[3].pid = syscall(__NR_gettid);
+	a[4].pid = getpid();
+	a[5].pid = getpgid(0);
+
+	for (unsigned int i = 0; i < ARRAY_SIZE(a); i++)
+		test_f_owner_ex_umove_or_printaddr(a[i].type, a[i].type_name,
+			a[i].pid_type, a[i].pid);
 }
 #endif /* TEST_F_OWNER_EX */
 
@@ -228,6 +247,23 @@ struct fcntl_cmd_check {
 	void (*print_flags)(long rc);
 };
 
+static void
+test_xetown(void)
+{
+	const int pid = getpid();
+	const char *pid_str = pidns_pid2str(PT_TGID);
+
+	invoke_test_syscall(0, F_SETOWN, (void *) (intptr_t) pid);
+	pidns_print_leader();
+	printf("%s(0, F_SETOWN, %d%s) = %s\n",
+		TEST_SYSCALL_STR, pid, pid_str, errstr);
+
+	invoke_test_syscall(0, F_GETOWN, NULL);
+	pidns_print_leader();
+	printf("%s(0, F_GETOWN) = %d%s\n",
+		TEST_SYSCALL_STR, pid, pid_str);
+}
+
 static void
 print_retval_flags(const struct fcntl_cmd_check *check, long rc)
 {
@@ -243,12 +279,14 @@ static void
 test_other_set_cmd(const struct fcntl_cmd_check *check)
 {
 	invoke_test_syscall(check->fd, check->cmd, (void *) check->arg);
+	pidns_print_leader();
 	printf("%s(%d, %s, %s) = %s\n",
 	       TEST_SYSCALL_STR, check->fd,
 	       check->cmd_str, check->arg_str, errstr);
 
 	/* bad file fd */
 	invoke_test_syscall(-1, check->cmd, (void *) check->arg);
+	pidns_print_leader();
 	printf("%s(-1, %s, %s) = %s\n",
 	       TEST_SYSCALL_STR, check->cmd_str,
 	       check->arg_str, errstr);
@@ -258,12 +296,14 @@ static void
 test_other_get_cmd(const struct fcntl_cmd_check *check)
 {
 	long rc = invoke_test_syscall(check->fd, check->cmd, NULL);
+	pidns_print_leader();
 	printf("%s(%d, %s) = ",
 	       TEST_SYSCALL_STR, check->fd, check->cmd_str);
 	print_retval_flags(check, rc);
 
 	/* bad file fd */
 	invoke_test_syscall(-1, check->cmd, NULL);
+	pidns_print_leader();
 	printf("%s(-1, %s) = %s\n",
 	       TEST_SYSCALL_STR, check->cmd_str, errstr);
 }
@@ -315,7 +355,6 @@ test_fcntl_others(void)
 {
 	static const struct fcntl_cmd_check set_checks[] = {
 		{ 0, ARG_STR(F_SETFD), ARG_STR(FD_CLOEXEC) },
-		{ 0, ARG_STR(F_SETOWN), ARG_STR(20) },
 #ifdef F_SETPIPE_SZ
 		{ 0, ARG_STR(F_SETPIPE_SZ), ARG_STR(4097) },
 #endif
@@ -336,7 +375,6 @@ test_fcntl_others(void)
 	static const struct fcntl_cmd_check get_checks[] = {
 		{ 0, ARG_STR(F_GETFD), .print_flags = print_flags_getfd },
 		{ 1, ARG_STR(F_GETFD), .print_flags = print_flags_getfd },
-		{ 0, ARG_STR(F_GETOWN) },
 #ifdef F_GETPIPE_SZ
 		{ 0, ARG_STR(F_GETPIPE_SZ) },
 #endif
@@ -360,6 +398,8 @@ create_sample(void)
 int
 main(void)
 {
+	PIDNS_TEST_INIT;
+
 	create_sample();
 	test_flock();
 	test_flock64();
@@ -367,7 +407,9 @@ main(void)
 	test_f_owner_ex();
 #endif
 	test_fcntl_others();
+	test_xetown();
 
+	pidns_print_leader();
 	puts("+++ exited with 0 +++");
 	return 0;
 }
diff --git a/tests/fcntl.c b/tests/fcntl.c
index f38b8afb..673c06e4 100644
--- a/tests/fcntl.c
+++ b/tests/fcntl.c
@@ -24,6 +24,7 @@ test_flock64_undecoded(const int cmd, const char *name)
 		.l_len = 0xdefaced2cafef00dULL
 	};
 	invoke_test_syscall(0, cmd, &fl);
+	pidns_print_leader();
 	printf("%s(0, %s, %p) = %s\n",
 	       TEST_SYSCALL_STR, name, &fl, errstr);
 }
diff --git a/tests/fcntl64--pidns-translation.c b/tests/fcntl64--pidns-translation.c
new file mode 100644
index 00000000..c6fdadd1
--- /dev/null
+++ b/tests/fcntl64--pidns-translation.c
@@ -0,0 +1,2 @@
+#define PIDNS_TRANSLATION
+#include "fcntl64.c"
diff --git a/tests/fcntl64.c b/tests/fcntl64.c
index 78e53b0d..f7b3f2fb 100644
--- a/tests/fcntl64.c
+++ b/tests/fcntl64.c
@@ -27,6 +27,7 @@ test_flock64_lk64(void)
 	fl->l_len = FILE_LEN;
 
 	long rc = invoke_test_syscall(0, F_SETLK64, fl);
+	pidns_print_leader();
 	printf("%s(0, F_SETLK64, {l_type=F_RDLCK, l_whence=SEEK_SET"
 	       ", l_start=0, l_len=%d}) = %s\n",
 	       TEST_SYSCALL_STR, FILE_LEN, errstr);
@@ -35,11 +36,13 @@ test_flock64_lk64(void)
 		return;
 
 	invoke_test_syscall(0, F_GETLK64, fl);
+	pidns_print_leader();
 	printf("%s(0, F_GETLK64, {l_type=F_UNLCK, l_whence=SEEK_SET"
 	       ", l_start=0, l_len=%d, l_pid=0}) = 0\n",
 	       TEST_SYSCALL_STR, FILE_LEN);
 
 	invoke_test_syscall(0, F_SETLKW64, fl);
+	pidns_print_leader();
 	printf("%s(0, F_SETLKW64, {l_type=F_UNLCK, l_whence=SEEK_SET"
 	       ", l_start=0, l_len=%d}) = 0\n",
 	       TEST_SYSCALL_STR, FILE_LEN);
diff --git a/tests/fork--pidns-translation.awk b/tests/fork--pidns-translation.awk
new file mode 100644
index 00000000..ef6858f4
--- /dev/null
+++ b/tests/fork--pidns-translation.awk
@@ -0,0 +1,15 @@
+/fork/ {
+        match($0, "([0-9]+) in strace\x27s PID NS", a);
+        if (a[1])
+                fork_pid = a[1]
+}
+
+/exited with 0/ {
+        if (!exit_pid)
+                exit_pid = $1
+}
+
+END {
+        if (!fork_pid || !exit_pid || fork_pid != exit_pid)
+                exit 1
+}
diff --git a/tests/fork--pidns-translation.c b/tests/fork--pidns-translation.c
new file mode 100644
index 00000000..73c39d5d
--- /dev/null
+++ b/tests/fork--pidns-translation.c
@@ -0,0 +1,69 @@
+/*
+ * Test PID namespace translation
+ *
+ * Copyright (c) 2020 ?kos Uzonyi <uzonyi.akos at gmail.com>
+ * All rights reserved.
+ *
+ * SPDX-License-Identifier: LGPL-2.1-or-later
+ */
+
+#include "tests.h"
+#include "scno.h"
+#include "pidns.h"
+
+#ifdef __NR_fork
+
+#include <errno.h>
+#include <limits.h>
+#include <sched.h>
+#include <signal.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <sys/wait.h>
+#include <unistd.h>
+#include <linux/sched.h>
+
+static int
+fork_chain(int depth)
+{
+	if (!depth)
+		return 0;
+
+	int pid = syscall(__NR_fork);
+	if (pid < 0)
+		return errno;
+
+	if (!pid)
+		_exit(fork_chain(depth - 1));
+
+	int status;
+	if (wait(&status) < 0)
+		return errno;
+
+	if (!WIFEXITED(status))
+		return -1;
+
+	return WEXITSTATUS(status);
+}
+
+int main(void)
+{
+	check_ns_ioctl();
+
+	if (unshare(CLONE_NEWPID | CLONE_NEWUSER) < 0) {
+		if (errno == EPERM)
+			perror_msg_and_skip("unshare");
+
+		perror_msg_and_fail("unshare");
+	}
+
+	errno = fork_chain(2);
+	if (errno)
+		perror("fork_chain");
+}
+
+#else
+
+SKIP_MAIN_UNDEFINED("__NR_fork")
+
+#endif
diff --git a/tests/fork--pidns-translation.test b/tests/fork--pidns-translation.test
new file mode 100755
index 00000000..fa7ecda5
--- /dev/null
+++ b/tests/fork--pidns-translation.test
@@ -0,0 +1,16 @@
+#!/bin/sh
+#
+# Check pidns translation of fork's return value.
+#
+# Copyright (c) 2020 The strace developers.
+# All rights reserved.
+#
+# SPDX-License-Identifier: LGPL-2.1-or-later
+
+. "${srcdir=.}/init.sh"
+
+require_min_kernel_version_or_skip 4.9
+
+run_prog
+run_strace -a6 --pidns-translation -f -e trace=fork $args
+match_awk
diff --git a/tests/gen_tests.in b/tests/gen_tests.in
index 6f8e1420..10374a9e 100644
--- a/tests/gen_tests.in
+++ b/tests/gen_tests.in
@@ -93,7 +93,9 @@ fchown	-a16
 fchown32	-a18
 fchownat
 fcntl	-a8
+fcntl--pidns-translation	test_pidns -a8 -e trace=fcntl
 fcntl64	-a8
+fcntl64--pidns-translation	test_pidns -a8 -e trace=fcntl64
 fdatasync	-a14
 file_handle	-e trace=name_to_handle_at,open_by_handle_at
 file_ioctl	+ioctl.test
@@ -147,7 +149,9 @@ getgroups	-a17
 getgroups32	-a19
 getpeername	-a27
 getpgrp	-a10
+getpgrp--pidns-translation	test_pidns -e trace=getpgrp -a10
 getpid	-a9
+getpid--pidns-translation	test_pidns -e trace=getpid -a9
 getppid	-a10
 getrandom	-a32 -s3
 getresgid	-a25
@@ -157,6 +161,7 @@ getresuid32	-a27
 getrlimit	-a27
 getrusage	-v
 getsid	-a10
+getsid--pidns-translation	test_pidns -e trace=getsid -a10
 getsockname	-a27
 gettid	-a9
 getuid-creds	+getuid.test
@@ -250,6 +255,7 @@ ioctl_watchdog	+ioctl.test
 ioperm	-a27
 iopl	-a8
 ioprio	-a18 -e trace=ioprio_get,ioprio_set
+ioprio--pidns-translation	test_pidns -a18 -e trace=ioprio_get,ioprio_set
 ioprio-Xabbrev	-a18 -e trace=ioprio_get,ioprio_set -Xabbrev
 ioprio-Xraw	-a18 -e trace=ioprio_get,ioprio_set -Xraw
 ioprio-Xverbose	-a18 -e trace=ioprio_get,ioprio_set -Xverbose
@@ -272,6 +278,7 @@ ipc_shm-Xraw	+ipc.sh -Xraw -a19
 ipc_shm-Xverbose	+ipc.sh -Xverbose -a34
 kcmp	-a22
 kcmp-y	-a22 -y -e trace=kcmp
+kcmp-y--pidns-translation	test_pidns -a22 -y -e trace=kcmp
 kern_features -a16
 kernel_version	-a16 -v -e trace=bpf
 kernel_version-Xabbrev	-a16 -Xabbrev -v -e trace=bpf
@@ -284,6 +291,7 @@ keyctl-Xabbrev	-a31 -s10 -e trace=keyctl -Xabbrev
 keyctl-Xraw	-a13 -s10 -e trace=keyctl -Xraw
 keyctl-Xverbose	-a41 -s10 -e trace=keyctl -Xverbose
 kill	-a12 -esignal=none
+kill--pidns-translation	test_pidns -a12 -e trace=kill -esignal=none
 ksysent	../$NAME
 lchown	-a30
 lchown32	-a32
@@ -305,6 +313,7 @@ memfd_create-Xabbrev	-Xabbrev -e trace=memfd_create
 memfd_create-Xraw	-a30 -Xraw -e trace=memfd_create
 memfd_create-Xverbose	-Xverbose -e trace=memfd_create
 migrate_pages	-a33
+migrate_pages--pidns-translation	test_pidns -a33 -e trace=migrate_pages
 mincore	-a22
 mkdir	-a20
 mkdirat	-a28
@@ -335,6 +344,7 @@ move_pages	-s3
 move_pages-Xabbrev	-s3 -e trace=move_pages -Xabbrev
 move_pages-Xraw	-s3 -a36 -e trace=move_pages -Xraw
 move_pages-Xverbose	-s3 -e trace=move_pages -Xverbose
+move_pages--pidns-translation	test_pidns -s3 -e trace=move_pages
 mq	-a32 -e trace=mq_getsetattr,mq_open,mq_unlink
 mq_sendrecv	-a14 -e trace=mq_open,mq_notify,mq_timedsend,mq_timedreceive,mq_unlink
 mq_sendrecv-read	-eread=0 -a14 -e trace=mq_open,mq_notify,mq_timedsend,mq_timedreceive,mq_unlink
@@ -354,6 +364,7 @@ net-packet_mreq-Xabbrev	-e trace=setsockopt -Xabbrev
 net-packet_mreq-Xraw	-e trace=setsockopt -Xraw
 net-packet_mreq-Xverbose	-e trace=setsockopt -Xverbose
 net-sockaddr	-a24 -e trace=connect
+net-sockaddr--pidns-translation	test_pidns -a24 -e trace=connect
 net-tpacket_req -e trace=setsockopt
 net-tpacket_stats -e trace=getsockopt
 net-yy-inet6	+net-yy-inet.test
@@ -457,7 +468,9 @@ pidfd_open--decode-fd-socket	-a17 -e decode-fd=socket -e trace=pidfd_open
 pidfd_open-P	-a17 -P /dev/full -e trace=pidfd_open
 pidfd_open-y	-a17 -y -e trace=pidfd_open
 pidfd_open-yy	-a17 -yy -e trace=pidfd_open
+pidfd_open--pidns-translation	test_pidns -a17 -e trace=pidfd_open
 pidfd_send_signal
+pidfd_send_signal--pidns-translation test_pidns -e trace=pidfd_send_signal
 pipe2	-a15
 pkey_alloc	-a17
 pkey_free	-a13
@@ -480,8 +493,11 @@ printstrn-umoven	-s4096 -e signal=none -e trace=add_key
 printstrn-umoven-peekdata	-e signal=none -e trace=add_key
 printstrn-umoven-undumpable	-e signal=none -e trace=add_key
 prlimit64
+prlimit64--pidns-translation     test_pidns -e trace=prlimit64
 process_vm_readv	-s5 -a37
+process_vm_readv--pidns-translation	test_pidns -s5 -a37 -e trace=process_vm_readv
 process_vm_writev	-s5 -a38
+process_vm_writev--pidns-translation	test_pidns -s5 -a38 -e trace=process_vm_writev
 pselect6
 ptrace	-a23 -e signal=none
 ptrace_syscall_info	-a35 -e signal=none -e trace=ptrace
@@ -518,10 +534,12 @@ rmdir	-a22
 rt_sigpending	-a20
 rt_sigprocmask
 rt_sigqueueinfo	-esignal=none
+rt_sigqueueinfo--pidns-translation	test_pidns -esignal=none -e trace=rt_sigqueueinfo
 rt_sigreturn	-esignal='!USR1'
 rt_sigsuspend	-a20 -esignal=none
 rt_sigtimedwait	-a38
 rt_tgsigqueueinfo	-esignal=none
+rt_tgsigqueueinfo--pidns-translation	test_pidns -esignal=none -e trace=rt_tgsigqueueinfo
 s390_guarded_storage	-a32
 s390_guarded_storage-v	-e trace=s390_guarded_storage -a32 -v
 s390_pci_mmio_read_write	-e trace=s390_pci_mmio_read,s390_pci_mmio_write -a30
@@ -532,9 +550,13 @@ sched	test_trace_expr times -e/sched
 sched_get_priority_mxx	-a33 -e trace=sched_get_priority_min,sched_get_priority_max
 sched_rr_get_interval	-a31
 sched_xetaffinity	-a28 -e trace=sched_getaffinity,sched_setaffinity
+sched_xetaffinity--pidns-translation	test_pidns -a28 -e trace=sched_getaffinity,sched_setaffinity
 sched_xetattr	-a29 -e trace=sched_getattr,sched_setattr
+sched_xetattr--pidns-translation	test_pidns -a29 -e trace=sched_getattr,sched_setattr
 sched_xetparam	-a23 -e trace=sched_getparam,sched_setparam
+sched_xetparam--pidns-translation	test_pidns -a23 -e trace=sched_getparam,sched_setparam
 sched_xetscheduler	-a22 -e trace=sched_getscheduler,sched_setscheduler
+sched_xetscheduler--pidns-translation	test_pidns -a22 -e trace=sched_getscheduler,sched_setscheduler
 sched_yield	-a14
 seccomp-filter	-e trace=seccomp
 seccomp-filter-v	-v -e trace=seccomp
@@ -581,6 +603,7 @@ sigaction	-a31
 siginfo	-e trace=none
 signal	-a25 -e signal=none -e trace='/^signal$'
 signal_receive	-a16 -e trace=kill
+signal_receive--pidns-translation	test_pidns -a16 -e trace=kill
 signalfd4
 sigpending	-a15
 sigprocmask	-a34
@@ -592,6 +615,7 @@ so_peercred	-e trace=getsockopt
 so_peercred-Xabbrev	-e trace=getsockopt -Xabbrev
 so_peercred-Xraw	-e trace=getsockopt -Xraw -a39
 so_peercred-Xverbose	-e trace=getsockopt -Xverbose
+so_peercred--pidns-translation	test_pidns -e trace=getsockopt
 sock_filter-v	-v -e trace=getsockopt,setsockopt
 sock_filter-v-Xabbrev	-v -e trace=getsockopt,setsockopt -X abbrev
 sock_filter-v-Xraw	-a 37 -v -e trace=getsockopt,setsockopt -X raw
@@ -721,7 +745,10 @@ waitpid	-a28
 xattr	-a22 -e trace=getxattr,fgetxattr,lgetxattr,setxattr,fsetxattr,lsetxattr,listxattr,flistxattr,llistxattr,removexattr,fremovexattr,lremovexattr
 xattr-strings	-a22 -s 4 -e trace=fsetxattr
 xet_robust_list	-a24 -e trace=get_robust_list,set_robust_list
+xet_robust_list--pidns-translation	test_pidns -a24 -e trace=get_robust_list,set_robust_list
 xetitimer	-a29 -e trace=setitimer,getitimer
 xetpgid	-a11 -e trace=getpgid,setpgid
-xetpriority	-a29 -e trace=getpriority,setpriority
+xetpgid--pidns-translation	test_pidns -a11 -e trace=getpgid,setpgid
+xetpriority	-a27 -e trace=getpriority,setpriority
+xetpriority--pidns-translation	test_pidns -a27 -e trace=getpriority,setpriority
 xettimeofday	-a20 -e trace=gettimeofday,settimeofday
diff --git a/tests/getpgrp--pidns-translation.c b/tests/getpgrp--pidns-translation.c
new file mode 100644
index 00000000..de8ceb33
--- /dev/null
+++ b/tests/getpgrp--pidns-translation.c
@@ -0,0 +1,2 @@
+#define PIDNS_TRANSLATION
+#include "getpgrp.c"
diff --git a/tests/getpgrp.c b/tests/getpgrp.c
index 104f4811..3f0b9dd1 100644
--- a/tests/getpgrp.c
+++ b/tests/getpgrp.c
@@ -7,6 +7,7 @@
 
 #include "tests.h"
 #include "scno.h"
+#include "pidns.h"
 
 #ifdef __NR_getpgrp
 
@@ -16,8 +17,13 @@
 int
 main(void)
 {
-	printf("getpgrp() = %ld\n", syscall(__NR_getpgrp));
+	PIDNS_TEST_INIT;
 
+	pidns_print_leader();
+	printf("getpgrp() = %d%s\n", (int) syscall(__NR_getpgrp),
+		pidns_pid2str(PT_PGID));
+
+	pidns_print_leader();
 	puts("+++ exited with 0 +++");
 	return 0;
 }
diff --git a/tests/getpid--pidns-translation.c b/tests/getpid--pidns-translation.c
new file mode 100644
index 00000000..94b12a1a
--- /dev/null
+++ b/tests/getpid--pidns-translation.c
@@ -0,0 +1,2 @@
+#define PIDNS_TRANSLATION
+#include "getpid.c"
diff --git a/tests/getpid.c b/tests/getpid.c
index 988f19d5..7ec4e6e8 100644
--- a/tests/getpid.c
+++ b/tests/getpid.c
@@ -7,6 +7,7 @@
 
 #include "tests.h"
 #include "scno.h"
+#include "pidns.h"
 
 #if defined __NR_getpid && (!defined __NR_getxpid || __NR_getxpid != __NR_getpid)
 
@@ -16,7 +17,12 @@
 int
 main(void)
 {
-	printf("getpid() = %ld\n", syscall(__NR_getpid));
+	PIDNS_TEST_INIT;
+
+	pidns_print_leader();
+	printf("getpid() = %d%s\n", (int) syscall(__NR_getpid),
+		pidns_pid2str(PT_TGID));
+	pidns_print_leader();
 	puts("+++ exited with 0 +++");
 	return 0;
 }
diff --git a/tests/getsid--pidns-translation.c b/tests/getsid--pidns-translation.c
new file mode 100644
index 00000000..7f983e87
--- /dev/null
+++ b/tests/getsid--pidns-translation.c
@@ -0,0 +1,2 @@
+#define PIDNS_TRANSLATION
+#include "getsid.c"
diff --git a/tests/getsid.c b/tests/getsid.c
index 588ea4ab..3bf74734 100644
--- a/tests/getsid.c
+++ b/tests/getsid.c
@@ -6,15 +6,22 @@
  */
 
 #include "tests.h"
+#include "pidns.h"
+
 #include <stdio.h>
 #include <unistd.h>
 
 int
 main(void)
 {
+	PIDNS_TEST_INIT;
+
 	pid_t pid = getpid();
-	printf("getsid(%d) = %d\n", pid, getsid(pid));
+	pidns_print_leader();
+	printf("getsid(%d%s) = %d%s\n", pid, pidns_pid2str(PT_TGID),
+		getsid(pid), pidns_pid2str(PT_SID));
 
+	pidns_print_leader();
 	puts("+++ exited with 0 +++");
 	return 0;
 }
diff --git a/tests/gettid--pidns-translation.c b/tests/gettid--pidns-translation.c
new file mode 100644
index 00000000..500c3213
--- /dev/null
+++ b/tests/gettid--pidns-translation.c
@@ -0,0 +1,2 @@
+#define PIDNS_TRANSLATION
+#include "gettid.c"
diff --git a/tests/gettid--pidns-translation.test b/tests/gettid--pidns-translation.test
new file mode 100755
index 00000000..0c7736fa
--- /dev/null
+++ b/tests/gettid--pidns-translation.test
@@ -0,0 +1,20 @@
+#!/bin/sh
+#
+# Check pidns translation of gettid's return value.
+#
+# Copyright (c) 2020 The strace developers.
+# All rights reserved.
+#
+# SPDX-License-Identifier: LGPL-2.1-or-later
+
+. "${srcdir=.}/init.sh"
+
+require_min_kernel_version_or_skip 4.9
+
+run_prog > /dev/null
+run_strace -a9 --pidns-translation -f -e trace=gettid $args > "$EXP"
+parent_pid="$(tail -n 2 $LOG | head -n 1 | cut -d' ' -f1)"
+init_pid="$(tail -n 1 $LOG | cut -d' ' -f1)"
+# uniq: filter out extra gettid calls made by musl libc
+grep -E -v "^($parent_pid|$init_pid) " "$LOG" | uniq > "$OUT"
+match_diff "$OUT" "$EXP"
diff --git a/tests/gettid.c b/tests/gettid.c
index d38918dd..314d9c2c 100644
--- a/tests/gettid.c
+++ b/tests/gettid.c
@@ -9,11 +9,17 @@
 #include <stdio.h>
 #include <unistd.h>
 #include "scno.h"
+#include "pidns.h"
 
 int
 main(void)
 {
-	printf("gettid() = %ld\n", syscall(__NR_gettid));
+	PIDNS_TEST_INIT;
+
+	pidns_print_leader();
+	printf("gettid() = %d%s\n", (int) syscall(__NR_gettid),
+		pidns_pid2str(PT_TID));
+	pidns_print_leader();
 	puts("+++ exited with 0 +++");
 	return 0;
 }
diff --git a/tests/ioctl_block--pidns-translation.c b/tests/ioctl_block--pidns-translation.c
new file mode 100644
index 00000000..5eed6076
--- /dev/null
+++ b/tests/ioctl_block--pidns-translation.c
@@ -0,0 +1,2 @@
+#define PIDNS_TRANSLATION
+#include "ioctl_block.c"
diff --git a/tests/ioctl_block--pidns-translation.test b/tests/ioctl_block--pidns-translation.test
new file mode 100755
index 00000000..bb45f695
--- /dev/null
+++ b/tests/ioctl_block--pidns-translation.test
@@ -0,0 +1,24 @@
+#!/bin/sh
+#
+# Check ioctl syscall decoding.
+#
+# Copyright (c) 2020 The strace developers.
+# All rights reserved.
+#
+# SPDX-License-Identifier: LGPL-2.1-or-later
+
+. "${srcdir=.}/init.sh"
+
+require_min_kernel_version_or_skip 4.9
+
+check_prog head
+check_prog tail
+check_prog cut
+check_prog grep
+
+run_prog > /dev/null
+run_strace --pidns-translation -f -a16 -e trace=ioctl $@ $args > "$EXP"
+parent_pid="$(tail -n 2 $LOG | head -n 1 | cut -d' ' -f1)"
+init_pid="$(tail -n 1 $LOG | cut -d' ' -f1)"
+grep -E -v "^($parent_pid|$init_pid) |ioctl\([0123][,<]" "$LOG" > "$OUT"
+match_diff "$OUT" "$EXP"
diff --git a/tests/ioctl_block.c b/tests/ioctl_block.c
index 0afe27f7..8a345f4e 100644
--- a/tests/ioctl_block.c
+++ b/tests/ioctl_block.c
@@ -9,7 +9,9 @@
  */
 
 #include "tests.h"
+#include "pidns.h"
 #include <errno.h>
+#include <unistd.h>
 #include <inttypes.h>
 #include <stdio.h>
 #include <string.h>
@@ -41,12 +43,15 @@ static struct xlat_data block_argless[] = {
 #define TEST_NULL_ARG(cmd)						\
 	do {								\
 		ioctl(-1, cmd, 0);					\
+		pidns_print_leader();					\
 		printf("ioctl(-1, %s, NULL) = -1 EBADF (%m)\n", #cmd);	\
 	} while (0)
 
 int
 main(void)
 {
+	PIDNS_TEST_INIT;
+
 	TEST_NULL_ARG(BLKBSZGET);
 	TEST_NULL_ARG(BLKBSZSET);
 	TEST_NULL_ARG(BLKFRAGET);
@@ -91,18 +96,22 @@ main(void)
 #endif
 
 	ioctl(-1, BLKRASET, lmagic);
+	pidns_print_leader();
 	printf("ioctl(-1, BLKRASET, %lu) = -1 EBADF (%m)\n", lmagic);
 
 	ioctl(-1, BLKFRASET, lmagic);
+	pidns_print_leader();
 	printf("ioctl(-1, BLKFRASET, %lu) = -1 EBADF (%m)\n", lmagic);
 
 	TAIL_ALLOC_OBJECT_CONST_PTR(int, val_int);
 	*val_int = magic;
 
 	ioctl(-1, BLKROSET, val_int);
+	pidns_print_leader();
 	printf("ioctl(-1, BLKROSET, [%d]) = -1 EBADF (%m)\n", *val_int);
 
 	ioctl(-1, BLKBSZSET, val_int);
+	pidns_print_leader();
 	printf("ioctl(-1, BLKBSZSET, [%d]) = -1 EBADF (%m)\n", *val_int);
 
 	uint64_t *pair_int64 = tail_alloc(sizeof(*pair_int64) * 2);
@@ -111,18 +120,21 @@ main(void)
 
 #ifdef BLKDISCARD
 	ioctl(-1, BLKDISCARD, pair_int64);
+	pidns_print_leader();
 	printf("ioctl(-1, BLKDISCARD, [%" PRIu64 ", %" PRIu64 "])"
 	       " = -1 EBADF (%m)\n", pair_int64[0], pair_int64[1]);
 #endif
 
 #ifdef BLKSECDISCARD
 	ioctl(-1, BLKSECDISCARD, pair_int64);
+	pidns_print_leader();
 	printf("ioctl(-1, BLKSECDISCARD, [%" PRIu64 ", %" PRIu64 "])"
 	       " = -1 EBADF (%m)\n", pair_int64[0], pair_int64[1]);
 #endif
 
 #ifdef BLKZEROOUT
 	ioctl(-1, BLKZEROOUT, pair_int64);
+	pidns_print_leader();
 	printf("ioctl(-1, BLKZEROOUT, [%" PRIu64 ", %" PRIu64 "])"
 	       " = -1 EBADF (%m)\n", pair_int64[0], pair_int64[1]);
 #endif
@@ -134,6 +146,7 @@ main(void)
 	blkpg->data = (void *) (unsigned long) 0xcafef00dfffffeedULL;
 
 	ioctl(-1, BLKPG, blkpg);
+	pidns_print_leader();
 	printf("ioctl(-1, BLKPG, {op=%s, flags=%d, datalen=%d"
 	       ", data=%#lx}) = -1 EBADF (%m)\n",
 	       "BLKPG_RESIZE_PARTITION", blkpg->flags, blkpg->datalen,
@@ -149,6 +162,7 @@ main(void)
 	blkpg->data = bp;
 
 	ioctl(-1, BLKPG, blkpg);
+	pidns_print_leader();
 	printf("ioctl(-1, BLKPG, {op=%s, flags=%d, datalen=%d"
 	       ", data={start=%lld, length=%lld, pno=%d"
 	       ", devname=\"%.*s\"..., volname=\"%.*s\"...}})"
@@ -162,25 +176,31 @@ main(void)
 #if defined BLKTRACESETUP && defined HAVE_STRUCT_BLK_USER_TRACE_SETUP
 	TAIL_ALLOC_OBJECT_CONST_PTR(struct blk_user_trace_setup, buts);
 	fill_memory(buts, sizeof(*buts));
+	buts->pid = getpid();
 
 	ioctl(-1, BLKTRACESETUP, buts);
+	pidns_print_leader();
 	printf("ioctl(-1, BLKTRACESETUP, {act_mask=%hu, buf_size=%u, buf_nr=%u"
-	       ", start_lba=%" PRI__u64 ", end_lba=%" PRI__u64 ", pid=%d})"
+	       ", start_lba=%" PRI__u64 ", end_lba=%" PRI__u64 ", pid=%d%s})"
 	       " = -1 EBADF (%m)\n",
 	       buts->act_mask, buts->buf_size, buts->buf_nr,
-	       buts->start_lba, buts->end_lba, buts->pid);
+	       buts->start_lba, buts->end_lba, buts->pid,
+	       pidns_pid2str(PT_TGID));
 #endif
 
 	unsigned int i;
 	for (i = 0; i < ARRAY_SIZE(block_argless); ++i) {
 		ioctl(-1, (unsigned long) block_argless[i].val, lmagic);
+		pidns_print_leader();
 		printf("ioctl(-1, %s) = -1 EBADF (%m)\n", block_argless[i].str);
 	}
 
 	ioctl(-1, _IOC(_IOC_READ, 0x12, 0xfe, 0xff), lmagic);
+	pidns_print_leader();
 	printf("ioctl(-1, %s, %#lx) = -1 EBADF (%m)\n",
 	       "_IOC(_IOC_READ, 0x12, 0xfe, 0xff)", lmagic);
 
+	pidns_print_leader();
 	puts("+++ exited with 0 +++");
 	return 0;
 }
diff --git a/tests/ioprio--pidns-translation.c b/tests/ioprio--pidns-translation.c
new file mode 100644
index 00000000..bcb49a8b
--- /dev/null
+++ b/tests/ioprio--pidns-translation.c
@@ -0,0 +1,2 @@
+#define PIDNS_TRANSLATION
+#include "ioprio.c"
diff --git a/tests/ioprio.c b/tests/ioprio.c
index 5e1e1194..110df063 100644
--- a/tests/ioprio.c
+++ b/tests/ioprio.c
@@ -9,8 +9,8 @@
  */
 
 #include "tests.h"
-
 #include "scno.h"
+#include "pidns.h"
 
 #if defined(__NR_ioprio_get) && defined(__NR_ioprio_set)
 
@@ -30,12 +30,18 @@ enum {
 int
 main(void)
 {
+	PIDNS_TEST_INIT;
+
 	static const kernel_ulong_t bogus_which =
 		(kernel_ulong_t) 0xdeadfacefa57beefULL;
 	static const kernel_ulong_t bogus_who =
 		(kernel_ulong_t) 0xbadc0dedda7a1057ULL;
 	static const kernel_ulong_t bogus_ioprio =
 		(kernel_ulong_t) 0xdec0ded1facefeedULL;
+
+	const int pid = getpid();
+	const int pgid = getpgid(0);
+
 # if !XLAT_RAW
 	static const char * const bogus_ioprio_str =
 		"IOPRIO_PRIO_VALUE(0x7d677 /* IOPRIO_CLASS_??? */, 7917)";
@@ -46,6 +52,7 @@ main(void)
 
 	rc = syscall(__NR_ioprio_get, bogus_which, bogus_who);
 	errstr = sprintrc(rc);
+	pidns_print_leader();
 # if XLAT_RAW
 	printf("ioprio_get(%#x, %d) = %s\n",
 	       (int) bogus_which, (int) bogus_who, errstr);
@@ -54,42 +61,52 @@ main(void)
 	       (int) bogus_which, (int) bogus_who, errstr);
 # endif
 
-	rc = syscall(__NR_ioprio_get, 1, 0);
+	rc = syscall(__NR_ioprio_get, 1, pid);
 	errstr = sprintrc(rc);
+	pidns_print_leader();
+	printf("ioprio_get(");
 # if XLAT_RAW
-	printf("ioprio_get(0x1, 0) = %s\n", errstr);
+	printf("0x1, ");
+# elif XLAT_VERBOSE
+	printf("0x1 /* IOPRIO_WHO_PROCESS */, ");
 # else /* XLAT_ABBREV */
-#  if XLAT_VERBOSE
-	printf("ioprio_get(0x1 /* IOPRIO_WHO_PROCESS */, 0) = %s", errstr);
-#  else
-	printf("ioprio_get(IOPRIO_WHO_PROCESS, 0) = %s", errstr);
-#  endif
+	printf("IOPRIO_WHO_PROCESS, ");
+# endif
+	printf("%d%s) = %s", pid, pidns_pid2str(PT_TGID), errstr);
+# if !XLAT_RAW
 	if (rc >= 0) {
 		printf(" (IOPRIO_PRIO_VALUE(");
 		printxval(ioprio_class, (unsigned int) rc >> 13,
 			  "IOPRIO_CLASS_???");
 		printf(", %u))", (unsigned int) rc & 0x1fff);
 	}
-	puts("");
 # endif
+	puts("");
 
-	rc = syscall(__NR_ioprio_set, 2, 0, 8191);
+	rc = syscall(__NR_ioprio_set, 2, pgid, 8191);
 	errstr = sprintrc(rc);
+	pidns_print_leader();
+	printf("ioprio_set(");
 # if XLAT_RAW
-	printf("ioprio_set(%#x, 0, 8191) = %s\n", 2, errstr);
+	printf("%#x", 2);
 # elif XLAT_VERBOSE
-	printf("ioprio_set(%#x /* IOPRIO_WHO_PGRP */, 0, 8191"
-	       " /* IOPRIO_PRIO_VALUE(0 /* IOPRIO_CLASS_NONE */, 8191) */)"
-	       " = %s\n",
-	       2, errstr);
+	printf("%#x /* IOPRIO_WHO_PGRP */", 2);
 # else /* XLAT_ABBREV */
-	printf("ioprio_set(IOPRIO_WHO_PGRP, 0"
-	       ", IOPRIO_PRIO_VALUE(IOPRIO_CLASS_NONE, 8191)) = %s\n",
-	       errstr);
+	printf("IOPRIO_WHO_PGRP");
+# endif
+	printf(", %d%s", pgid, pidns_pid2str(PT_PGID));
+# if XLAT_RAW
+	printf(", 8191)");
+# elif XLAT_VERBOSE
+	printf(", 8191 /* IOPRIO_PRIO_VALUE(0 /* IOPRIO_CLASS_NONE */, 8191) */)");
+# else /* XLAT_ABBREV */
+	printf(", IOPRIO_PRIO_VALUE(IOPRIO_CLASS_NONE, 8191))");
 # endif
+	printf(" = %s\n", errstr);
 
 	rc = syscall(__NR_ioprio_set, bogus_which, bogus_who, bogus_ioprio);
 	errstr = sprintrc(rc);
+	pidns_print_leader();
 # if XLAT_RAW
 	printf("ioprio_set(%#x, %d, %d) = %s\n",
 	       (int) bogus_which, (int) bogus_who, (int) bogus_ioprio,
@@ -104,6 +121,7 @@ main(void)
 	       errstr);
 # endif
 
+	pidns_print_leader();
 	puts("+++ exited with 0 +++");
 
 	return 0;
diff --git a/tests/kcmp-y--pidns-translation.c b/tests/kcmp-y--pidns-translation.c
new file mode 100644
index 00000000..f54d94cc
--- /dev/null
+++ b/tests/kcmp-y--pidns-translation.c
@@ -0,0 +1,2 @@
+#define PIDNS_TRANSLATION
+#include "kcmp-y.c"
diff --git a/tests/kcmp.c b/tests/kcmp.c
index dc5ba9a4..ce705ad0 100644
--- a/tests/kcmp.c
+++ b/tests/kcmp.c
@@ -9,8 +9,8 @@
  */
 
 #include "tests.h"
-
 #include "scno.h"
+#include "pidns.h"
 
 #ifdef __NR_kcmp
 
@@ -101,7 +101,11 @@ do_kcmp(kernel_ulong_t pid1, kernel_ulong_t pid2, kernel_ulong_t type,
 	rc = syscall(__NR_kcmp, pid1, pid2, type, idx1, idx2);
 	errstr = sprintrc(rc);
 
-	printf("kcmp(%d, %d, ", (int) pid1, (int) pid2);
+	const char *pid_str = pidns_pid2str(PT_TGID);
+	pidns_print_leader();
+	printf("kcmp(%d%s, %d%s, ",
+		(int) pid1, (int) pid1 == getpid() ? pid_str : "",
+		(int) pid2, (int) pid2 == getpid() ? pid_str : "");
 
 	if (type_str)
 		printf("%s", type_str);
@@ -146,6 +150,8 @@ do_kcmp(kernel_ulong_t pid1, kernel_ulong_t pid2, kernel_ulong_t type,
 int
 main(void)
 {
+	PIDNS_TEST_INIT;
+
 	static const kernel_ulong_t bogus_pid1 =
 		(kernel_ulong_t) 0xdeadca75face1057ULL;
 	static const kernel_ulong_t bogus_pid2 =
@@ -221,6 +227,7 @@ main(void)
 			(uintptr_t) slot, 1);
 	}
 
+	pidns_print_leader();
 	puts("+++ exited with 0 +++");
 
 	return 0;
diff --git a/tests/kill--pidns-translation.c b/tests/kill--pidns-translation.c
new file mode 100644
index 00000000..4736ca14
--- /dev/null
+++ b/tests/kill--pidns-translation.c
@@ -0,0 +1,2 @@
+#define PIDNS_TRANSLATION
+#include "kill.c"
diff --git a/tests/kill.c b/tests/kill.c
index f7d9341e..17de35da 100644
--- a/tests/kill.c
+++ b/tests/kill.c
@@ -11,6 +11,7 @@
 
 #include "tests.h"
 #include "scno.h"
+#include "pidns.h"
 
 #ifdef __NR_kill
 
@@ -26,6 +27,8 @@ handler(int sig)
 int
 main(void)
 {
+	PIDNS_TEST_INIT;
+
 	const struct sigaction act = { .sa_handler = handler };
 	if (sigaction(SIGALRM, &act, NULL))
 		perror_msg_and_fail("sigaction");
@@ -37,18 +40,23 @@ main(void)
 		perror_msg_and_fail("sigprocmask");
 
 	const int pid = getpid();
+	const char *pid_str = pidns_pid2str(PT_TGID);
 	long rc = syscall(__NR_kill, pid, (long) 0xdefaced00000000ULL | SIGALRM);
-	printf("kill(%d, SIGALRM) = %ld\n", pid, rc);
+	pidns_print_leader();
+	printf("kill(%d%s, SIGALRM) = %ld\n", pid, pid_str, rc);
 
 	const long big_pid = (long) 0xfacefeedbadc0dedULL;
 	const long big_sig = (long) 0xdeadbeefcafef00dULL;
 	rc = syscall(__NR_kill, big_pid, big_sig);
+	pidns_print_leader();
 	printf("kill(%d, %d) = %ld %s (%m)\n",
 	       (int) big_pid, (int) big_sig, rc, errno2name());
 
 	rc = syscall(__NR_kill, (long) 0xdefaced00000000ULL | pid, 0);
-	printf("kill(%d, 0) = %ld\n", pid, rc);
+	pidns_print_leader();
+	printf("kill(%d%s, 0) = %ld\n", pid, pid_str, rc);
 
+	pidns_print_leader();
 	puts("+++ exited with 0 +++");
 	return 0;
 }
diff --git a/tests/migrate_pages--pidns-translation.c b/tests/migrate_pages--pidns-translation.c
new file mode 100644
index 00000000..ec34938d
--- /dev/null
+++ b/tests/migrate_pages--pidns-translation.c
@@ -0,0 +1,2 @@
+#define PIDNS_TRANSLATION
+#include "migrate_pages.c"
diff --git a/tests/migrate_pages.c b/tests/migrate_pages.c
index 2dfba49c..390b490b 100644
--- a/tests/migrate_pages.c
+++ b/tests/migrate_pages.c
@@ -10,6 +10,7 @@
 
 #include "tests.h"
 #include "scno.h"
+#include "pidns.h"
 
 #ifdef __NR_migrate_pages
 
@@ -19,11 +20,21 @@
 int
 main(void)
 {
-	const long pid = (long) 0xfacefeedffffffffULL;
+	PIDNS_TEST_INIT;
+
+	const long pid = (long) 0xfacefeed00000000ULL | getpid();
 	long rc = syscall(__NR_migrate_pages, pid, 0, 0, 0);
-	printf("migrate_pages(%d, 0, NULL, NULL) = %ld %s (%m)\n",
-	       (int) pid, rc, errno2name());
 
+	pidns_print_leader();
+	printf("migrate_pages(%d%s, 0, NULL, NULL) = %ld",
+		(int) pid, pidns_pid2str(PT_TGID), rc);
+
+	if (rc < 0)
+		printf(" %s (%m)\n", errno2name());
+	else
+		printf("\n");
+
+	pidns_print_leader();
 	puts("+++ exited with 0 +++");
 	return 0;
 }
diff --git a/tests/move_pages--pidns-translation.c b/tests/move_pages--pidns-translation.c
new file mode 100644
index 00000000..8498e399
--- /dev/null
+++ b/tests/move_pages--pidns-translation.c
@@ -0,0 +1,2 @@
+#define PIDNS_TRANSLATION
+#include "move_pages.c"
diff --git a/tests/move_pages.c b/tests/move_pages.c
index e00fd1ac..56843158 100644
--- a/tests/move_pages.c
+++ b/tests/move_pages.c
@@ -10,6 +10,7 @@
 
 #include "tests.h"
 #include "scno.h"
+#include "pidns.h"
 
 #ifdef __NR_move_pages
 
@@ -122,15 +123,20 @@ print_status_array(const int *const status, const unsigned long count)
 }
 
 static void
-print_stat_pages(const unsigned long pid, const unsigned long count,
-		 const void **const pages, int *const status)
+print_stat_pages(const unsigned long pid,
+		 const char *pid_str,
+		 const unsigned long count,
+		 const void **const pages,
+		 int *const status)
 {
 	const unsigned long flags = (unsigned long) 0xfacefeed00000002ULL;
 
 	long rc = syscall(__NR_move_pages,
 			  pid, count, pages, NULL, status, flags);
 	const char *errstr = sprintrc(rc);
-	printf("move_pages(%d, %lu, ", (int) pid, count);
+	pidns_print_leader();
+	printf("move_pages(%d%s, %lu, ", (int) pid, pid_str,
+		count);
 	print_page_array(pages, count, 0);
 	printf(", NULL, ");
 	if (rc) {
@@ -152,6 +158,7 @@ print_stat_pages(const unsigned long pid, const unsigned long count,
 
 static void
 print_move_pages(const unsigned long pid,
+		 const char *pid_str,
 		 unsigned long count,
 		 const unsigned int offset,
 		 const void **const pages,
@@ -164,7 +171,9 @@ print_move_pages(const unsigned long pid,
 	long rc = syscall(__NR_move_pages,
 			  pid, count, pages, nodes, status, flags);
 	const char *errstr = sprintrc(rc);
-	printf("move_pages(%d, %lu, ", (int) pid, count);
+	pidns_print_leader();
+	printf("move_pages(%d%s, %lu, ", (int) pid, pid_str,
+		count);
 	print_page_array(pages, count, offset);
 	printf(", ");
 	print_node_array(nodes, count, offset);
@@ -185,8 +194,11 @@ print_move_pages(const unsigned long pid,
 int
 main(void)
 {
+	PIDNS_TEST_INIT;
+
 	const unsigned long pid =
 		(unsigned long) 0xfacefeed00000000ULL | getpid();
+	const char *pid_str = pidns_pid2str(PT_TGID);
 	unsigned long count = 1;
 	const unsigned page_size = get_page_size();
 	const void *const page = tail_alloc(page_size);
@@ -195,40 +207,41 @@ main(void)
 	TAIL_ALLOC_OBJECT_VAR_PTR(int, nodes);
 	TAIL_ALLOC_OBJECT_VAR_PTR(int, status);
 
-	print_stat_pages(pid, 0, pages, status);
-	print_move_pages(pid, 0, 0, pages, nodes, status);
-	print_move_pages(pid, 0, 1, pages + 1, nodes + 1, status + 1);
+	print_stat_pages(pid, pid_str, 0, pages, status);
+	print_move_pages(pid, pid_str, 0, 0, pages, nodes, status);
+	print_move_pages(pid, pid_str, 0, 1, pages + 1, nodes + 1, status + 1);
 
 	*pages = page;
-	print_stat_pages(pid, count, pages, status);
+	print_stat_pages(pid, pid_str, count, pages, status);
 	*nodes = 0xdeadbee1;
-	print_move_pages(pid, count, 0, pages, nodes, status);
-	print_move_pages(pid, count, 1, pages, nodes, status);
+	print_move_pages(pid, pid_str, count, 0, pages, nodes, status);
+	print_move_pages(pid, pid_str, count, 1, pages, nodes, status);
 
 	++count;
 	--status;
 	*(--pages) = efault;
-	print_stat_pages(pid, count, pages, status);
+	print_stat_pages(pid, pid_str, count, pages, status);
 	*(--nodes) = 0xdeadbee2;
-	print_move_pages(pid, count, 0, pages, nodes, status);
-	print_move_pages(pid, count, 1, pages, nodes, status);
+	print_move_pages(pid, pid_str, count, 0, pages, nodes, status);
+	print_move_pages(pid, pid_str, count, 1, pages, nodes, status);
 
 	++count;
 	--status;
 	*(--pages) = nodes;
-	print_stat_pages(pid, count, pages, status);
+	print_stat_pages(pid, pid_str, count, pages, status);
 	*(--nodes) = 0xdeadbee3;
-	print_move_pages(pid, count, 0, pages, nodes, status);
-	print_move_pages(pid, count, 1, pages, nodes, status);
+	print_move_pages(pid, pid_str, count, 0, pages, nodes, status);
+	print_move_pages(pid, pid_str, count, 1, pages, nodes, status);
 
 	++count;
 	--status;
 	*(--pages) = status;
-	print_stat_pages(pid, count, pages, status);
+	print_stat_pages(pid, pid_str, count, pages, status);
 	*(--nodes) = 0xdeadbee4;
-	print_move_pages(pid, count, 0, pages, nodes, status);
-	print_move_pages(pid, count, 1, pages, nodes, status);
+	print_move_pages(pid, pid_str, count, 0, pages, nodes, status);
+	print_move_pages(pid, pid_str, count, 1, pages, nodes, status);
 
+	pidns_print_leader();
 	puts("+++ exited with 0 +++");
 	return 0;
 }
diff --git a/tests/net-sockaddr--pidns-translation.c b/tests/net-sockaddr--pidns-translation.c
new file mode 100644
index 00000000..ff432bf4
--- /dev/null
+++ b/tests/net-sockaddr--pidns-translation.c
@@ -0,0 +1,2 @@
+#define PIDNS_TRANSLATION
+#include "net-sockaddr.c"
diff --git a/tests/net-sockaddr.c b/tests/net-sockaddr.c
index 4fc9da6e..b9cd46fd 100644
--- a/tests/net-sockaddr.c
+++ b/tests/net-sockaddr.c
@@ -9,6 +9,7 @@
  */
 
 #include "tests.h"
+#include "pidns.h"
 #include <stddef.h>
 #include <stdio.h>
 #include <string.h>
@@ -40,18 +41,21 @@ check_un(void)
 	memset(un->sun_path, '0', sizeof(un->sun_path));
 	unsigned int len = sizeof(*un);
 	int ret = connect(-1, (void *) un, len);
+	pidns_print_leader();
 	printf("connect(-1, {sa_family=AF_UNIX, sun_path=\"%.*u\"}"
 	       ", %u) = %d EBADF (%m)\n",
 	       (int) sizeof(un->sun_path), 0, len, ret);
 
 	un->sun_path[1] = 0;
 	ret = connect(-1, (void *) un, len);
+	pidns_print_leader();
 	printf("connect(-1, {sa_family=AF_UNIX, sun_path=\"%u\"}, %u)"
 	       " = %d EBADF (%m)\n", 0, len, ret);
 
 	un->sun_path[0] = 0;
 	un->sun_path[2] = 1;
 	ret = connect(-1, (void *) un, len);
+	pidns_print_leader();
 	printf("connect(-1, {sa_family=AF_UNIX, sun_path=@\"\\0\\001%.*u\"}"
 	       ", %u) = %d EBADF (%m)\n",
 	       (int) sizeof(un->sun_path) - 3, 0, len, ret);
@@ -61,12 +65,14 @@ check_un(void)
 	memset(un->sun_path, '0', sizeof(un->sun_path));
 	len = sizeof(*un) + 2;
 	ret = connect(-1, (void *) un, len);
+	pidns_print_leader();
 	printf("connect(-1, {sa_family=AF_UNIX, sun_path=\"%.*u\"}"
 	       ", %u) = %d EBADF (%m)\n",
 	       (int) sizeof(un->sun_path), 0, len, ret);
 
 	un->sun_path[0] = 0;
 	ret = connect(-1, (void *) un, len);
+	pidns_print_leader();
 	printf("connect(-1, {sa_family=AF_UNIX, sun_path=@\"%.*u\"}"
 	       ", %u) = %d EBADF (%m)\n",
 	       (int) sizeof(un->sun_path) - 1, 0, len, ret);
@@ -75,18 +81,21 @@ check_un(void)
 	un->sun_family = AF_UNIX;
 	len = sizeof(*un) - 2;
 	ret = connect(-1, (void *) un, len);
+	pidns_print_leader();
 	printf("connect(-1, {sa_family=AF_UNIX, sun_path=\"%.*u\"}"
 	       ", %u) = %d EBADF (%m)\n",
 	       (int) sizeof(un->sun_path) - 2, 0, len, ret);
 
 	un->sun_path[0] = 0;
 	ret = connect(-1, (void *) un, len);
+	pidns_print_leader();
 	printf("connect(-1, {sa_family=AF_UNIX, sun_path=@\"%.*u\"}"
 	       ", %u) = %d EBADF (%m)\n",
 	       (int) sizeof(un->sun_path) - 3, 0, len, ret);
 
 	len = sizeof(*un);
 	ret = connect(-1, (void *) un, len);
+	pidns_print_leader();
 	printf("connect(-1, %p, %u) = %d EBADF (%m)\n", un, len, ret);
 
 	un = tail_alloc(sizeof(struct sockaddr_storage));
@@ -94,12 +103,14 @@ check_un(void)
 	memset(un->sun_path, '0', sizeof(un->sun_path));
 	len = sizeof(struct sockaddr_storage) + 1;
 	ret = connect(-1, (void *) un, len);
+	pidns_print_leader();
 	printf("connect(-1, {sa_family=AF_UNIX, sun_path=\"%.*u\"}"
 	       ", %u) = %d EBADF (%m)\n",
 	       (int) sizeof(un->sun_path), 0, len, ret);
 
 	un->sun_path[0] = 0;
 	ret = connect(-1, (void *) un, len);
+	pidns_print_leader();
 	printf("connect(-1, {sa_family=AF_UNIX, sun_path=@\"%.*u\"}"
 	       ", %u) = %d EBADF (%m)\n",
 	       (int) sizeof(un->sun_path) - 1, 0, len, ret);
@@ -117,6 +128,7 @@ check_in(void)
 	in->sin_addr.s_addr = inet_addr(h_addr);
 	unsigned int len = sizeof(*in);
 	int ret = connect(-1, (void *) in, len);
+	pidns_print_leader();
 	printf("connect(-1, {sa_family=AF_INET, sin_port=htons(%hu)"
 	       ", sin_addr=inet_addr(\"%s\")}, %u) = %d EBADF (%m)\n",
 	       h_port, h_addr, len, ret);
@@ -127,6 +139,7 @@ check_in(void)
 	in->sin_addr.s_addr = inet_addr(h_addr);
 	len = sizeof(*in) + 4;
 	ret = connect(-1, (void *) in, len);
+	pidns_print_leader();
 	printf("connect(-1, {sa_family=AF_INET, sin_port=htons(%hu)"
 	       ", sin_addr=inet_addr(\"%s\")}, %u) = %d EBADF (%m)\n",
 	       h_port, h_addr, len, ret);
@@ -137,6 +150,7 @@ check_in(void)
 	in->sin_addr.s_addr = 0;
 	len = sizeof(*in) - 4;
 	ret = connect(-1, (void *) in, len);
+	pidns_print_leader();
 	printf("connect(-1, {sa_family=AF_INET, sa_data=\"%s\"}, %u)"
 	       " = %d EBADF (%m)\n",
 	       "\\0\\0\\0\\0\\0\\0\\377\\377\\377\\377",
@@ -144,6 +158,7 @@ check_in(void)
 
 	len = sizeof(*in);
 	ret = connect(-1, (void *) in, len);
+	pidns_print_leader();
 	printf("connect(-1, %p, %u) = %d EBADF (%m)\n", in, len, ret);
 }
 
@@ -155,6 +170,7 @@ check_in6_linklocal(struct sockaddr_in6 *const in6, const char *const h_addr)
 	in6->sin6_scope_id = 0xfacefeed;
 	unsigned int len = sizeof(*in6);
 	int ret = connect(-1, (void *) in6, len);
+	pidns_print_leader();
 	printf("connect(-1, {sa_family=AF_INET6, sin6_port=htons(%hu)"
 	       ", sin6_flowinfo=htonl(%u)"
 	       ", inet_pton(AF_INET6, \"%s\", &sin6_addr)"
@@ -166,7 +182,8 @@ check_in6_linklocal(struct sockaddr_in6 *const in6, const char *const h_addr)
 	in6->sin6_scope_id = ifindex_lo();
 	if (in6->sin6_scope_id) {
 		ret = connect(-1, (void *) in6, len);
-		printf("connect(-1, {sa_family=AF_INET6, sin6_port=htons(%hu)"
+		pidns_print_leader();
+	printf("connect(-1, {sa_family=AF_INET6, sin6_port=htons(%hu)"
 		       ", sin6_flowinfo=htonl(%u)"
 		       ", inet_pton(AF_INET6, \"%s\", &sin6_addr)"
 		       ", sin6_scope_id=%s}, %u)"
@@ -191,6 +208,7 @@ check_in6(void)
 	in6->sin6_scope_id = 0xfacefeed;
 	unsigned int len = sizeof(*in6);
 	int ret = connect(-1, (void *) in6, len);
+	pidns_print_leader();
 	printf("connect(-1, {sa_family=AF_INET6, sin6_port=htons(%hu)"
 	       ", sin6_flowinfo=htonl(%u)"
 	       ", inet_pton(AF_INET6, \"%s\", &sin6_addr)"
@@ -209,6 +227,7 @@ check_in6(void)
 	in6->sin6_scope_id = 0xfacefeed;
 	len = sizeof(*in6) + 4;
 	ret = connect(-1, (void *) in6, len);
+	pidns_print_leader();
 	printf("connect(-1, {sa_family=AF_INET6, sin6_port=htons(%hu)"
 	       ", sin6_flowinfo=htonl(%u)"
 	       ", inet_pton(AF_INET6, \"%s\", &sin6_addr)"
@@ -223,6 +242,7 @@ check_in6(void)
 	inet_pton(AF_INET6, h_addr, &in6->sin6_addr);
 	len = sizeof(*in6) - sizeof(in6->sin6_scope_id);
 	ret = connect(-1, (void *) in6, len);
+	pidns_print_leader();
 	printf("connect(-1, {sa_family=AF_INET6, sin6_port=htons(%hu)"
 	       ", sin6_flowinfo=htonl(%u)"
 	       ", inet_pton(AF_INET6, \"%s\", &sin6_addr)}, %u)"
@@ -236,6 +256,7 @@ check_in6(void)
 	memset(&in6->sin6_addr, '0', sizeof(in6->sin6_addr) - 4);
 	len = sizeof(*in6) - sizeof(in6->sin6_scope_id) - 4;
 	ret = connect(-1, (void *) in6, len);
+	pidns_print_leader();
 	printf("connect(-1, {sa_family=AF_INET6"
 	       ", sa_data=\"\\0\\0\\0\\0\\0\\000%.*u\"}, %u)"
 	       " = %d EBADF (%m)\n",
@@ -244,6 +265,7 @@ check_in6(void)
 
 	len = sizeof(*in6) - sizeof(in6->sin6_scope_id);
 	ret = connect(-1, (void *) in6, len);
+	pidns_print_leader();
 	printf("connect(-1, %p, %u) = %d EBADF (%m)\n", in6, len, ret);
 }
 
@@ -262,6 +284,7 @@ check_ipx(void)
 	void *ipx = tail_memdup(&c_ipx, sizeof(c_ipx));
 	unsigned int len = sizeof(c_ipx);
 	int ret = connect(-1, ipx, len);
+	pidns_print_leader();
 	printf("connect(-1, {sa_family=AF_IPX, sipx_port=htons(%u)"
 	       ", sipx_network=htonl(%#x)"
 	       ", sipx_node=[%#02x, %#02x, %#02x, %#02x, %#02x, %#02x]"
@@ -316,18 +339,21 @@ check_ax25(void)
 	fill_memory(sax, size);
 	sax->fsa_ax25.sax25_family = AF_AX25;
 	rc = connect(-1, sax_void, sizeof(struct sockaddr_ax25) - 1);
+	pidns_print_leader();
 	printf("connect(-1, {sa_family=AF_AX25, sa_data=\"\\202\\203\\204\\205"
 	       "\\206\\207\\210\\211\\212\\213\\214\\215\\216\"}, %zu) = %s\n",
 	       sizeof(struct sockaddr_ax25) - 1, sprintrc(rc));
 
 	memcpy(sax, &ax25, sizeof(ax25));
 	rc = connect(-1, sax_void, sizeof(struct sockaddr_ax25));
+	pidns_print_leader();
 	printf("connect(-1, {sa_family=AF_AX25, fsa_ax25={sax25_call=VALID-13"
 	       ", sax25_ndigis=8}, fsa_digipeater=[/* ??? */]}, %zu) = %s\n",
 	       sizeof(struct sockaddr_ax25), sprintrc(rc));
 
 	sax->fsa_ax25.sax25_ndigis = 0;
 	rc = connect(-1, sax_void, sizeof(struct sockaddr_ax25));
+	pidns_print_leader();
 	printf("connect(-1, {sa_family=AF_AX25, sax25_call=VALID-13"
 	       ", sax25_ndigis=0}, %zu) = %s\n",
 	       sizeof(struct sockaddr_ax25), sprintrc(rc));
@@ -335,6 +361,7 @@ check_ax25(void)
 	sax->fsa_ax25.sax25_ndigis = 8;
 	size = sizeof(struct sockaddr_ax25) + sizeof(ax25_address) * 3 + 1;
 	rc = connect(-1, sax_void, size);
+	pidns_print_leader();
 	printf("connect(-1, {sa_family=AF_AX25, fsa_ax25={sax25_call=VALID-13"
 	       ", sax25_ndigis=8}, fsa_digipeater"
 	       "=[{ax25_call=\"\\xa6\\xa0\\x82\\x40\\x86\\x8a\\x00\""
@@ -348,6 +375,7 @@ check_ax25(void)
 	sax->fsa_digipeater[2].ax25_call[6] = 0x4;
 	size = sizeof(struct sockaddr_ax25) + sizeof(ax25_address) * 4;
 	rc = connect(-1, sax_void, size);
+	pidns_print_leader();
 	printf("connect(-1, {sa_family=AF_AX25, fsa_ax25={sax25_call=VALID-13"
 	       ", sax25_ndigis=8}, fsa_digipeater"
 	       "=[{ax25_call=\"\\xa6\\xa0\\x82\\x40\\x86\\x8a\\x00\""
@@ -365,7 +393,8 @@ check_ax25(void)
 	for (size_t i = 0; i < 3; i++) {
 		size = sizeof(ax25) + sizeof(ax25_address) * (i / 2);
 		rc = connect(-1, sax_void, size);
-		printf("connect(-1, {sa_family=AF_AX25"
+		pidns_print_leader();
+	printf("connect(-1, {sa_family=AF_AX25"
 		       ", fsa_ax25={sax25_call=VALID-13, sax25_ndigis=%d}"
 		       ", fsa_digipeater=[VALID2-7, OK-15, %s /* FINE-2 */"
 		       ", {ax25_call=\"\\xe6\\xda\\xc2\\xd8\\xd8\\xe6\\x12\""
@@ -427,13 +456,15 @@ check_x25(void)
 	long rc;
 
 	rc = connect(-1, x25_void, sizeof(c_x25) - 1);
+	pidns_print_leader();
 	printf("connect(-1, {sa_family=AF_X25"
 	       ", sa_data=\"0123456789abcde\"}, %zu) = %s\n",
 	       sizeof(c_x25) - 1, sprintrc(rc));
 
 	for (size_t i = 0; i < 2; i++) {
 		rc = connect(-1, x25_void, sizeof(c_x25) + i);
-		printf("connect(-1, {sa_family=AF_X25"
+		pidns_print_leader();
+	printf("connect(-1, {sa_family=AF_X25"
 		       ", sx25_addr={x25_addr=\"0123456789abcde\"...}"
 		       "}, %zu) = %s\n",
 		       sizeof(c_x25) + i, sprintrc(rc));
@@ -442,6 +473,7 @@ check_x25(void)
 	struct sockaddr_x25 *const x25 = x25_void;
 	x25->sx25_addr.x25_addr[10] = '\0';
 	rc = connect(-1, x25_void, sizeof(c_x25));
+	pidns_print_leader();
 	printf("connect(-1, {sa_family=AF_X25"
 	       ", sx25_addr={x25_addr=\"0123456789\"}"
 	       "}, %zu) = %s\n",
@@ -457,19 +489,21 @@ check_nl(void)
 	nl->nl_groups = 0xfacefeed;
 	unsigned int len = sizeof(*nl);
 	int ret = connect(-1, (void *) nl, len);
+	pidns_print_leader();
 	printf("connect(-1, {sa_family=AF_NETLINK, nl_pid=%d"
 	       ", nl_groups=%#08x}, %u) = %d EBADF (%m)\n",
 	       nl->nl_pid, nl->nl_groups, len, ret);
 
 	nl = ((void *) nl) - 4;
 	nl->nl_family = AF_NETLINK;
-	nl->nl_pid = 1234567890;
+	nl->nl_pid = getpid();
 	nl->nl_groups = 0xfacefeed;
 	len = sizeof(*nl) + 4;
 	ret = connect(-1, (void *) nl, len);
-	printf("connect(-1, {sa_family=AF_NETLINK, nl_pid=%d"
+	pidns_print_leader();
+	printf("connect(-1, {sa_family=AF_NETLINK, nl_pid=%d%s"
 	       ", nl_groups=%#08x}, %u) = %d EBADF (%m)\n",
-	       nl->nl_pid, nl->nl_groups, len, ret);
+	       nl->nl_pid, pidns_pid2str(PT_TGID), nl->nl_groups, len, ret);
 }
 
 static void
@@ -487,6 +521,7 @@ check_ll(void)
 	void *ll = tail_memdup(&c_ll, sizeof(c_ll));
 	unsigned int len = sizeof(c_ll);
 	int ret = connect(-1, ll, len);
+	pidns_print_leader();
 	printf("connect(-1, {sa_family=AF_PACKET"
 	       ", sll_protocol=htons(ETH_P_ALL)"
 	       ", sll_ifindex=%u, sll_hatype=ARPHRD_ETHER"
@@ -502,6 +537,7 @@ check_ll(void)
 
 	((struct sockaddr_ll *) ll)->sll_halen++;
 	ret = connect(-1, ll, len);
+	pidns_print_leader();
 	printf("connect(-1, {sa_family=AF_PACKET"
 	       ", sll_protocol=htons(ETH_P_ALL)"
 	       ", sll_ifindex=%u, sll_hatype=ARPHRD_ETHER"
@@ -517,6 +553,7 @@ check_ll(void)
 
 	((struct sockaddr_ll *) ll)->sll_halen = 0;
 	ret = connect(-1, ll, len);
+	pidns_print_leader();
 	printf("connect(-1, {sa_family=AF_PACKET"
 	       ", sll_protocol=htons(ETH_P_ALL)"
 	       ", sll_ifindex=%u, sll_hatype=ARPHRD_ETHER"
@@ -526,7 +563,8 @@ check_ll(void)
 	((struct sockaddr_ll *) ll)->sll_ifindex = ifindex_lo();
 	if (((struct sockaddr_ll *) ll)->sll_ifindex) {
 		ret = connect(-1, ll, len);
-		printf("connect(-1, {sa_family=AF_PACKET"
+	pidns_print_leader();
+	printf("connect(-1, {sa_family=AF_PACKET"
 		       ", sll_protocol=htons(ETH_P_ALL)"
 		       ", sll_ifindex=%s"
 		       ", sll_hatype=ARPHRD_ETHER"
@@ -549,11 +587,13 @@ check_hci(void)
 	unsigned int len = sizeof(*hci);
 
 	int ret = connect(-1, (void *) hci, 4);
+	pidns_print_leader();
 	printf("connect(-1, {sa_family=AF_BLUETOOTH, hci_dev=htobs(%hu)"
 	       "}, 4) = %d EBADF (%m)\n",
 	       h_port, ret);
 
 	ret = connect(-1, (void *) hci, len);
+	pidns_print_leader();
 	printf("connect(-1, {sa_family=AF_BLUETOOTH, hci_dev=htobs(%hu)"
 # ifdef HAVE_STRUCT_SOCKADDR_HCI_HCI_CHANNEL
 	       ", hci_channel=HCI_CHANNEL_RAW"
@@ -572,6 +612,7 @@ check_sco(void)
 	void *sco = tail_memdup(&c_sco, sizeof(c_sco));
 	unsigned int len = sizeof(c_sco);
 	int ret = connect(-1, sco, len);
+	pidns_print_leader();
 	printf("connect(-1, {sa_family=AF_BLUETOOTH"
 	       ", sco_bdaddr=%02x:%02x:%02x:%02x:%02x:%02x"
 	       "}, %u) = %d EBADF (%m)\n",
@@ -592,6 +633,7 @@ check_rc(void)
 	void *rc = tail_memdup(&c_rc, sizeof(c_rc));
 	unsigned int len = sizeof(c_rc);
 	int ret = connect(-1, rc, len);
+	pidns_print_leader();
 	printf("connect(-1, {sa_family=AF_BLUETOOTH"
 	       ", rc_bdaddr=%02x:%02x:%02x:%02x:%02x:%02x"
 	       ", rc_channel=%u}, %u) = %d EBADF (%m)\n",
@@ -619,6 +661,7 @@ check_l2(void)
 	unsigned int len = sizeof(c_l2);
 
 	int ret = connect(-1, l2, len);
+	pidns_print_leader();
 	printf("connect(-1, {sa_family=AF_BLUETOOTH"
 	       ", l2_psm=htobs(L2CAP_PSM_DYN_START + %hu)"
 	       ", l2_bdaddr=%02x:%02x:%02x:%02x:%02x:%02x"
@@ -640,6 +683,7 @@ check_l2(void)
 # endif
 	memcpy(l2, &c_l2, sizeof(c_l2));
 	ret = connect(-1, l2, len);
+	pidns_print_leader();
 	printf("connect(-1, {sa_family=AF_BLUETOOTH"
 	       ", l2_psm=htobs(L2CAP_PSM_SDP)"
 	       ", l2_bdaddr=%02x:%02x:%02x:%02x:%02x:%02x"
@@ -660,6 +704,7 @@ check_l2(void)
 # endif
 	memcpy(l2, &c_l2, sizeof(c_l2));
 	ret = connect(-1, l2, len);
+	pidns_print_leader();
 	printf("connect(-1, {sa_family=AF_BLUETOOTH"
 	       ", l2_psm=htobs(0xbad /* L2CAP_PSM_??? */)"
 	       ", l2_bdaddr=%02x:%02x:%02x:%02x:%02x:%02x"
@@ -677,6 +722,7 @@ check_l2(void)
 	c_l2.l2_cid = htobs(0xffff);
 	memcpy(l2, &c_l2, 12);
 	ret = connect(-1, l2, 12);
+	pidns_print_leader();
 	printf("connect(-1, {sa_family=AF_BLUETOOTH"
 	       ", l2_psm=htobs(L2CAP_PSM_AUTO_END)"
 	       ", l2_bdaddr=%02x:%02x:%02x:%02x:%02x:%02x"
@@ -700,6 +746,7 @@ check_raw(void)
 	u.sa->sa_family = 0xff;
 	unsigned int len = sizeof(*u.st) + 8;
 	int ret = connect(-1, (void *) u.st, len);
+	pidns_print_leader();
 	printf("connect(-1, {sa_family=%#x /* AF_??? */, sa_data=\"%.*u\"}"
 	       ", %u) = %d EBADF (%m)\n", u.sa->sa_family,
 	       (int) (sizeof(*u.st) - sizeof(u.sa->sa_family)), 0, len, ret);
@@ -707,11 +754,13 @@ check_raw(void)
 	u.sa->sa_family = 0;
 	len = sizeof(u.sa->sa_family) + 1;
 	ret = connect(-1, (void *) u.st, len);
+	pidns_print_leader();
 	printf("connect(-1, {sa_family=AF_UNSPEC, sa_data=\"0\"}, %u)"
 	       " = %d EBADF (%m)\n", len, ret);
 
 	u.sa->sa_family = AF_BLUETOOTH;
 	ret = connect(-1, (void *) u.st, len);
+	pidns_print_leader();
 	printf("connect(-1, {sa_family=AF_BLUETOOTH, sa_data=\"0\"}, %u)"
 	       " = %d EBADF (%m)\n", len, ret);
 }
@@ -719,6 +768,8 @@ check_raw(void)
 int
 main(void)
 {
+	PIDNS_TEST_INIT;
+
 	check_un();
 	check_in();
 	check_in6();
@@ -735,6 +786,7 @@ main(void)
 #endif
 	check_raw();
 
+	pidns_print_leader();
 	puts("+++ exited with 0 +++");
 	return 0;
 }
diff --git a/tests/netlink_audit--pidns-translation.c b/tests/netlink_audit--pidns-translation.c
new file mode 100644
index 00000000..e08f9168
--- /dev/null
+++ b/tests/netlink_audit--pidns-translation.c
@@ -0,0 +1,2 @@
+#define PIDNS_TRANSLATION
+#include "netlink_audit.c"
diff --git a/tests/netlink_audit--pidns-translation.test b/tests/netlink_audit--pidns-translation.test
new file mode 100755
index 00000000..fbc32435
--- /dev/null
+++ b/tests/netlink_audit--pidns-translation.test
@@ -0,0 +1,13 @@
+#!/bin/sh
+#
+# Check decoding of NETLINK_SOCK_DIAG protocol
+#
+# Copyright (c) 2020 The strace developers.
+# All rights reserved.
+#
+# SPDX-License-Identifier: LGPL-2.1-or-later
+
+. "${srcdir=.}/init.sh"
+
+run_prog ../netlink_netlink_diag
+test_pidns -e trace=sendto "$@"
diff --git a/tests/netlink_audit.c b/tests/netlink_audit.c
index eba609a1..5dfcd786 100644
--- a/tests/netlink_audit.c
+++ b/tests/netlink_audit.c
@@ -7,6 +7,7 @@
  */
 
 #include "tests.h"
+#include "pidns.h"
 #include <stdio.h>
 #include <string.h>
 #include <unistd.h>
@@ -17,18 +18,23 @@
 static void
 test_nlmsg_type(const int fd)
 {
+	PIDNS_TEST_INIT;
+
 	long rc;
 	struct nlmsghdr nlh = {
 		.nlmsg_len = sizeof(nlh),
 		.nlmsg_type = AUDIT_GET,
 		.nlmsg_flags = NLM_F_REQUEST,
+		.nlmsg_pid = getpid(),
 	};
 
 	rc = sendto(fd, &nlh, sizeof(nlh), MSG_DONTWAIT, NULL, 0);
+	pidns_print_leader();
 	printf("sendto(%d, {len=%u, type=AUDIT_GET"
-	       ", flags=NLM_F_REQUEST, seq=0, pid=0}"
+	       ", flags=NLM_F_REQUEST, seq=0, pid=%d%s}"
 	       ", %u, MSG_DONTWAIT, NULL, 0) = %s\n",
-	       fd, nlh.nlmsg_len, (unsigned) sizeof(nlh), sprintrc(rc));
+	       fd, nlh.nlmsg_len, nlh.nlmsg_pid, pidns_pid2str(PT_TGID),
+	       (unsigned) sizeof(nlh), sprintrc(rc));
 }
 
 int main(void)
@@ -39,6 +45,7 @@ int main(void)
 
 	test_nlmsg_type(fd);
 
+	pidns_print_leader();
 	printf("+++ exited with 0 +++\n");
 
 	return 0;
diff --git a/tests/pidfd_open--pidns-translation.c b/tests/pidfd_open--pidns-translation.c
new file mode 100644
index 00000000..c38e37a8
--- /dev/null
+++ b/tests/pidfd_open--pidns-translation.c
@@ -0,0 +1,2 @@
+#define PIDNS_TRANSLATION
+#include "pidfd_open.c"
diff --git a/tests/pidfd_open.c b/tests/pidfd_open.c
index 5860adde..e5d74a91 100644
--- a/tests/pidfd_open.c
+++ b/tests/pidfd_open.c
@@ -10,6 +10,7 @@
 
 #include "tests.h"
 #include "scno.h"
+#include "pidns.h"
 
 #ifdef __NR_pidfd_open
 
@@ -37,6 +38,8 @@ k_pidfd_open(const unsigned int pid, const unsigned int flags)
 int
 main(void)
 {
+	PIDNS_TEST_INIT;
+
 # if defined PATH_TRACING || defined PRINT_PATHS
 	skip_if_unavailable("/proc/self/fd/");
 # endif
@@ -50,16 +53,19 @@ main(void)
 
 	k_pidfd_open(0, 0);
 # ifndef PATH_TRACING
+	pidns_print_leader();
 	printf("pidfd_open(0, 0) = %s\n", errstr);
 # endif
 
 	k_pidfd_open(-1U, 0);
 # ifndef PATH_TRACING
+	pidns_print_leader();
 	printf("pidfd_open(-1, 0) = %s\n", errstr);
 # endif
 
 	k_pidfd_open(0, -1U);
 # ifndef PATH_TRACING
+	pidns_print_leader();
 	printf("pidfd_open(0, %#x) = %s\n", -1U, errstr);
 # endif
 
@@ -68,7 +74,10 @@ main(void)
 
 	k_pidfd_open(pid, flags);
 # ifndef PATH_TRACING
-	printf("pidfd_open(%d, %#x) = %s\n", pid, flags, errstr);
+	const char *pid_str = pidns_pid2str(PT_TGID);
+	pidns_print_leader();
+	printf("pidfd_open(%d%s, %#x) = %s\n",
+		pid, pid_str, flags, errstr);
 # endif
 
 # ifdef PRINT_PATHS
@@ -80,17 +89,19 @@ main(void)
 # endif
 
 # ifndef PATH_TRACING
-	printf("pidfd_open(%d, 0) = "
+	pidns_print_leader();
+	printf("pidfd_open(%d%s, 0) = "
 #  if defined PRINT_PIDFD
-	       "%ld<pid:%d>\n", pid, rc, pid
+	       "%ld<pid:%d>\n", pid, pid_str, rc, pid
 #  elif defined PRINT_PATHS
-	       "%ld<anon_inode:[pidfd]>\n", pid, rc
+	       "%ld<anon_inode:[pidfd]>\n", pid, pid_str, rc
 #  else
-	       "%s\n", pid, errstr
+	       "%s\n", pid, pid_str, errstr
 #  endif
 	       );
 # endif
 
+	pidns_print_leader();
 	puts("+++ exited with 0 +++");
 	return 0;
 }
diff --git a/tests/pidfd_send_signal--pidns-translation.c b/tests/pidfd_send_signal--pidns-translation.c
new file mode 100644
index 00000000..b04f10f5
--- /dev/null
+++ b/tests/pidfd_send_signal--pidns-translation.c
@@ -0,0 +1,2 @@
+#define PIDNS_TRANSLATION
+#include "pidfd_send_signal.c"
diff --git a/tests/pidfd_send_signal.c b/tests/pidfd_send_signal.c
index 38b5bda1..a6b2d28c 100644
--- a/tests/pidfd_send_signal.c
+++ b/tests/pidfd_send_signal.c
@@ -10,6 +10,7 @@
 #include "tests.h"
 #include <unistd.h>
 #include "scno.h"
+#include "pidns.h"
 
 #ifdef __NR_pidfd_send_signal
 
@@ -36,6 +37,8 @@ sys_pidfd_send_signal(int pidfd, int sig, const void *info, int flags)
 int
 main(void)
 {
+	PIDNS_TEST_INIT;
+
 	static const char null_path[] = "/dev/null";
 
 	int fd = open(null_path, O_RDONLY);
@@ -46,19 +49,23 @@ main(void)
 	const void *esi = (const void *) si + 1;
 
 	sys_pidfd_send_signal(fd, SIGUSR1, esi, 0);
+	pidns_print_leader();
 	printf("pidfd_send_signal(%d, SIGUSR1, %p, 0) = %s\n",
 	       fd, esi, errstr);
 
 	si->si_signo = SIGUSR1;
 	si->si_code = SI_QUEUE;
+	si->si_pid = getpid();
 
 	sys_pidfd_send_signal(fd, SIGUSR2, si, -1);
+	pidns_print_leader();
 	printf("pidfd_send_signal(%d, SIGUSR2, {si_signo=SIGUSR1"
-	       ", si_code=SI_QUEUE, si_errno=%u, si_pid=%d, si_uid=%d"
+	       ", si_code=SI_QUEUE, si_errno=%u, si_pid=%d%s, si_uid=%d"
 	       ", si_value={int=%d, ptr=%p}}, %#x) = %s\n",
-	       fd, si->si_errno, si->si_pid, si->si_uid, si->si_int, si->si_ptr,
-	       -1U, errstr);
+	       fd, si->si_errno, si->si_pid, pidns_pid2str(PT_TGID), si->si_uid,
+	       si->si_int, si->si_ptr, -1U, errstr);
 
+	pidns_print_leader();
 	puts("+++ exited with 0 +++");
 	return 0;
 }
diff --git a/tests/prlimit64--pidns-translation.c b/tests/prlimit64--pidns-translation.c
new file mode 100644
index 00000000..3972de66
--- /dev/null
+++ b/tests/prlimit64--pidns-translation.c
@@ -0,0 +1,2 @@
+#define PIDNS_TRANSLATION
+#include "prlimit64.c"
diff --git a/tests/prlimit64.c b/tests/prlimit64.c
index 34201a2b..bc1a80b3 100644
--- a/tests/prlimit64.c
+++ b/tests/prlimit64.c
@@ -19,6 +19,7 @@
 # include <sys/resource.h>
 # include <unistd.h>
 
+# include "pidns.h"
 # include "xlat.h"
 # include "xlat/resources.h"
 
@@ -42,8 +43,11 @@ sprint_rlim(uint64_t lim)
 int
 main(void)
 {
+	PIDNS_TEST_INIT;
+
 	unsigned long pid =
 		(unsigned long) 0xdefaced00000000ULL | (unsigned) getpid();
+	const char *pid_str = pidns_pid2str(PT_TGID);
 	uint64_t *const rlimit = tail_alloc(sizeof(*rlimit) * 2);
 	const struct xlat_data *xlat;
 	size_t i = 0;
@@ -54,18 +58,23 @@ main(void)
 
 		unsigned long res = 0xfacefeed00000000ULL | xlat->val;
 		long rc = syscall(__NR_prlimit64, pid, res, 0, rlimit);
+		pidns_print_leader();
 		if (rc)
-			printf("prlimit64(%d, %s, NULL, %p) = %ld %s (%m)\n",
-			       (unsigned) pid, xlat->str, rlimit,
+			printf("prlimit64(%d%s, %s, NULL, %p) ="
+				     " %ld %s (%m)\n",
+			       (unsigned) pid, pid_str,
+			       xlat->str, rlimit,
 			       rc, errno2name());
 		else
-			printf("prlimit64(%d, %s, NULL"
+			printf("prlimit64(%d%s, %s, NULL"
 			       ", {rlim_cur=%s, rlim_max=%s}) = 0\n",
-			       (unsigned) pid, xlat->str,
+			       (unsigned) pid, pid_str,
+			       xlat->str,
 			       sprint_rlim(rlimit[0]),
 			       sprint_rlim(rlimit[1]));
 	}
 
+	pidns_print_leader();
 	puts("+++ exited with 0 +++");
 	return 0;
 }
diff --git a/tests/process_vm_readv--pidns-translation.c b/tests/process_vm_readv--pidns-translation.c
new file mode 100644
index 00000000..0db29ca2
--- /dev/null
+++ b/tests/process_vm_readv--pidns-translation.c
@@ -0,0 +1,2 @@
+#define PIDNS_TRANSLATION
+#include "process_vm_readv.c"
diff --git a/tests/process_vm_readv_writev.c b/tests/process_vm_readv_writev.c
index 9309135a..44e511dd 100644
--- a/tests/process_vm_readv_writev.c
+++ b/tests/process_vm_readv_writev.c
@@ -12,6 +12,7 @@
 #include <stdio.h>
 #include <unistd.h>
 #include <sys/uio.h>
+#include "pidns.h"
 
 #if OP_WR
 # define in_iovec  rmt_iovec
@@ -121,7 +122,7 @@ print_iov(const struct iovec *iov, const void *arg_ptr, long rc)
 }
 
 static void
-do_call(kernel_ulong_t pid,
+do_call(kernel_ulong_t pid, enum pid_type pid_type,
 	kernel_ulong_t local_iov, const char *local_arg,
 	kernel_ulong_t liovcnt,
 	kernel_ulong_t remote_iov, const char *remote_arg,
@@ -135,7 +136,8 @@ do_call(kernel_ulong_t pid,
 		flags);
 	errstr = sprintrc(rc);
 
-	printf("%s(%d, ", OP_STR, (int) pid);
+	pidns_print_leader();
+	printf("%s(%d%s, ", OP_STR, (int) pid, pidns_pid2str(pid_type));
 
 	if (pr_iov)
 		pr_iov((const struct iovec *) (uintptr_t) local_iov, local_arg,
@@ -164,6 +166,8 @@ ptr_cast(void *ptr)
 int
 main(void)
 {
+	PIDNS_TEST_INIT;
+
 	enum {
 		SIZE_11 = 2,
 		SIZE_12 = 3,
@@ -243,18 +247,18 @@ main(void)
 	fill_memory_ex(data2_out, SIZE_2, SEGM2_BASE, SIZE_2);
 
 
-	do_call(bogus_pid, (kernel_ulong_t) (uintptr_t) ARG_STR(NULL),
+	do_call(bogus_pid, PT_NONE, (kernel_ulong_t) (uintptr_t) ARG_STR(NULL),
 		bogus_iovcnt1, (kernel_ulong_t) (uintptr_t) ARG_STR(NULL),
 		bogus_iovcnt2, bogus_flags, NULL);
 
-	do_call(my_pid, ptr_cast(bogus_iov + ARRAY_SIZE(bogus_iovec)),
+	do_call(my_pid, PT_TGID, ptr_cast(bogus_iov + ARRAY_SIZE(bogus_iovec)),
 		"[]", 0, ptr_cast(in_iov + ARRAY_SIZE(in_iovec)), "[]",
 		0, 0, NULL);
-	do_call(my_pid, ptr_cast(bogus_iov + ARRAY_SIZE(bogus_iovec)), NULL,
-		bogus_iovcnt1, ptr_cast(in_iov + ARRAY_SIZE(in_iovec)), NULL,
-		bogus_iovcnt2, 0, print_iov);
+	do_call(my_pid, PT_TGID, ptr_cast(bogus_iov + ARRAY_SIZE(bogus_iovec)),
+		NULL, bogus_iovcnt1, ptr_cast(in_iov + ARRAY_SIZE(in_iovec)),
+		NULL, bogus_iovcnt2, 0, print_iov);
 
-	do_call(my_pid, ptr_cast(bogus_iov), (char *) &bogus_arg,
+	do_call(my_pid, PT_TGID, ptr_cast(bogus_iov), (char *) &bogus_arg,
 		ARRAY_SIZE(bogus_iovec), ptr_cast(rmt_iov + 2),
 		(char *) &rmt_arg_cut, ARRAY_SIZE(rmt_iovec) - 2, 0, print_iov);
 
@@ -263,7 +267,7 @@ main(void)
 	lcl_arg_cut.check_rc = 1;
 #endif
 
-	do_call(my_pid, ptr_cast(lcl_iov + 2), (char *) &lcl_arg_cut,
+	do_call(my_pid, PT_TGID, ptr_cast(lcl_iov + 2), (char *) &lcl_arg_cut,
 		ARRAY_SIZE(lcl_iovec) - 1, ptr_cast(bogus_iov + 2),
 		(char *) &bogus_arg_cut, ARRAY_SIZE(bogus_iovec) - 1, 0,
 		print_iov);
@@ -273,15 +277,16 @@ main(void)
 	rmt_arg_cut.addr_term = 1;
 	rmt_arg_cut.count = 5;
 
-	do_call(my_pid, ptr_cast(lcl_iov + 2), (char *) &lcl_arg_cut,
+	do_call(my_pid, PT_TGID, ptr_cast(lcl_iov + 2), (char *) &lcl_arg_cut,
 		ARRAY_SIZE(lcl_iovec) - 2, ptr_cast(rmt_iov + 1),
 		(char *) &rmt_arg_cut, ARRAY_SIZE(rmt_iovec), 0, print_iov);
 
 	/* Correct call */
-	do_call(my_pid, ptr_cast(lcl_iov), (char *) &lcl_arg,
+	do_call(my_pid, PT_TGID, ptr_cast(lcl_iov), (char *) &lcl_arg,
 		ARRAY_SIZE(lcl_iovec), ptr_cast(rmt_iov), (char *) &rmt_arg,
 		ARRAY_SIZE(rmt_iovec), 0, print_iov);
 
+	pidns_print_leader();
 	puts("+++ exited with 0 +++");
 
 	return 0;
diff --git a/tests/process_vm_writev--pidns-translation.c b/tests/process_vm_writev--pidns-translation.c
new file mode 100644
index 00000000..9ba6a39b
--- /dev/null
+++ b/tests/process_vm_writev--pidns-translation.c
@@ -0,0 +1,2 @@
+#define PIDNS_TRANSLATION
+#include "process_vm_writev.c"
diff --git a/tests/rt_sigqueueinfo--pidns-translation.c b/tests/rt_sigqueueinfo--pidns-translation.c
new file mode 100644
index 00000000..74bfb464
--- /dev/null
+++ b/tests/rt_sigqueueinfo--pidns-translation.c
@@ -0,0 +1,2 @@
+#define PIDNS_TRANSLATION
+#include "rt_sigqueueinfo.c"
diff --git a/tests/rt_sigqueueinfo.c b/tests/rt_sigqueueinfo.c
index c1693873..e22e4640 100644
--- a/tests/rt_sigqueueinfo.c
+++ b/tests/rt_sigqueueinfo.c
@@ -7,6 +7,7 @@
  */
 
 #include "tests.h"
+#include "pidns.h"
 #include <assert.h>
 #include <stdio.h>
 #include <signal.h>
@@ -15,6 +16,8 @@
 int
 main(void)
 {
+	PIDNS_TEST_INIT;
+
 	struct sigaction sa = {
 		.sa_handler = SIG_IGN
 	};
@@ -22,15 +25,19 @@ main(void)
 		.sival_ptr = (void *) (unsigned long) 0xdeadbeefbadc0dedULL
 	};
 	pid_t pid = getpid();
+	const char *pid_str = pidns_pid2str(PT_TGID);
 
 	assert(sigaction(SIGUSR1, &sa, NULL) == 0);
 	if (sigqueue(pid, SIGUSR1, value))
 		perror_msg_and_skip("sigqueue");
-	printf("rt_sigqueueinfo(%u, SIGUSR1, {si_signo=SIGUSR1, "
-		"si_code=SI_QUEUE, si_pid=%d, si_uid=%d, "
+	pidns_print_leader();
+	printf("rt_sigqueueinfo(%d%s, SIGUSR1, {si_signo=SIGUSR1, "
+		"si_code=SI_QUEUE, si_pid=%d%s, si_uid=%u, "
 		"si_value={int=%d, ptr=%p}}) = 0\n",
-		pid, pid, getuid(), value.sival_int, value.sival_ptr);
-	printf("+++ exited with 0 +++\n");
+		pid, pid_str, pid, pid_str,
+		getuid(), value.sival_int, value.sival_ptr);
+	pidns_print_leader();
+	puts("+++ exited with 0 +++");
 
 	return 0;
 }
diff --git a/tests/rt_tgsigqueueinfo--pidns-translation.c b/tests/rt_tgsigqueueinfo--pidns-translation.c
new file mode 100644
index 00000000..94396f00
--- /dev/null
+++ b/tests/rt_tgsigqueueinfo--pidns-translation.c
@@ -0,0 +1,2 @@
+#define PIDNS_TRANSLATION
+#include "rt_tgsigqueueinfo.c"
diff --git a/tests/rt_tgsigqueueinfo.c b/tests/rt_tgsigqueueinfo.c
index 865c21f6..21d01cbb 100644
--- a/tests/rt_tgsigqueueinfo.c
+++ b/tests/rt_tgsigqueueinfo.c
@@ -10,8 +10,9 @@
 
 #include "tests.h"
 #include "scno.h"
+#include "pidns.h"
 
-#ifdef __NR_rt_tgsigqueueinfo
+#if defined __NR_rt_tgsigqueueinfo && defined __NR_gettid
 
 # include <errno.h>
 # include <signal.h>
@@ -20,11 +21,11 @@
 # include <unistd.h>
 
 static long
-k_tgsigqueueinfo(const pid_t pid, const int sig, const void *const info)
+k_tgsigqueueinfo(const pid_t tgid, const int tid, const int sig, const void *const info)
 {
 	return syscall(__NR_rt_tgsigqueueinfo,
-		       F8ILL_KULONG_MASK | pid,
-		       F8ILL_KULONG_MASK | pid,
+		       F8ILL_KULONG_MASK | tgid,
+		       F8ILL_KULONG_MASK | tid,
 		       F8ILL_KULONG_MASK | sig,
 		       info);
 }
@@ -32,6 +33,8 @@ k_tgsigqueueinfo(const pid_t pid, const int sig, const void *const info)
 int
 main(void)
 {
+	PIDNS_TEST_INIT;
+
 	const struct sigaction sa = {
 		.sa_handler = SIG_IGN
 	};
@@ -48,17 +51,22 @@ main(void)
 	info->si_value.sival_ptr =
 		(void *) (unsigned long) 0xdeadbeeffacefeedULL;
 
-	if (k_tgsigqueueinfo(info->si_pid, SIGUSR1, info))
+	if (k_tgsigqueueinfo(getpid(), syscall(__NR_gettid), SIGUSR1, info))
 		(errno == ENOSYS ? perror_msg_and_skip : perror_msg_and_fail)(
 			"rt_tgsigqueueinfo");
 
-	printf("rt_tgsigqueueinfo(%u, %u, %s, {si_signo=%s"
-		", si_code=SI_QUEUE, si_errno=ENOENT, si_pid=%d"
+	pidns_print_leader();
+	printf("rt_tgsigqueueinfo(%d%s, %d%s, %s, {si_signo=%s"
+		", si_code=SI_QUEUE, si_errno=ENOENT, si_pid=%d%s"
 		", si_uid=%d, si_value={int=%d, ptr=%p}}) = 0\n",
-		info->si_pid, info->si_pid, "SIGUSR1", "SIGUSR1",
-		info->si_pid, info->si_uid, info->si_value.sival_int,
+		info->si_pid, pidns_pid2str(PT_TGID),
+		info->si_pid, pidns_pid2str(PT_TID),
+		"SIGUSR1", "SIGUSR1",
+		info->si_pid, pidns_pid2str(PT_TGID),
+		info->si_uid, info->si_value.sival_int,
 		info->si_value.sival_ptr);
 
+	pidns_print_leader();
 	puts("+++ exited with 0 +++");
 	return 0;
 }
diff --git a/tests/sched_xetaffinity--pidns-translation.c b/tests/sched_xetaffinity--pidns-translation.c
new file mode 100644
index 00000000..814e3989
--- /dev/null
+++ b/tests/sched_xetaffinity--pidns-translation.c
@@ -0,0 +1,2 @@
+#define PIDNS_TRANSLATION
+#include "sched_xetaffinity.c"
diff --git a/tests/sched_xetaffinity.c b/tests/sched_xetaffinity.c
index cebff3ab..2e508ca3 100644
--- a/tests/sched_xetaffinity.c
+++ b/tests/sched_xetaffinity.c
@@ -10,6 +10,7 @@
 
 #include "tests.h"
 #include "scno.h"
+#include "pidns.h"
 #include <sched.h>
 
 #if defined __NR_sched_getaffinity && defined __NR_sched_setaffinity \
@@ -41,8 +42,11 @@ setaffinity(unsigned long pid, unsigned long size, void *set)
 int
 main(void)
 {
+	PIDNS_TEST_INIT;
+
 	unsigned int cpuset_size = 1;
 	const pid_t pid = getpid();
+	const char *pid_str = pidns_pid2str(PT_TGID);
 
 	while (cpuset_size) {
 		assert(getaffinity(pid, cpuset_size, NULL) == -1);
@@ -50,18 +54,21 @@ main(void)
 			break;
 		if (EINVAL != errno)
 			perror_msg_and_skip("sched_getaffinity");
-		printf("sched_getaffinity(%d, %u, NULL) = %s\n",
-		       pid, cpuset_size, errstr);
+		pidns_print_leader();
+		printf("sched_getaffinity(%d%s, %u, NULL) = %s\n",
+		       pid, pid_str, cpuset_size, errstr);
 		cpuset_size <<= 1;
 	}
 	assert(cpuset_size);
-	printf("sched_getaffinity(%d, %u, NULL) = %s\n",
-	       pid, cpuset_size, errstr);
+	pidns_print_leader();
+	printf("sched_getaffinity(%d%s, %u, NULL) = %s\n",
+	       pid, pid_str, cpuset_size, errstr);
 
 	cpu_set_t *cpuset = tail_alloc(cpuset_size);
 	getaffinity(pid, cpuset_size, cpuset + 1);
-	printf("sched_getaffinity(%d, %u, %p) = %s\n",
-	       pid, cpuset_size, cpuset + 1, errstr);
+	pidns_print_leader();
+	printf("sched_getaffinity(%d%s, %u, %p) = %s\n",
+	       pid, pid_str, cpuset_size, cpuset + 1, errstr);
 
 	int ret_size = getaffinity(pid, cpuset_size, cpuset);
 	if (ret_size < 0)
@@ -69,7 +76,8 @@ main(void)
 				    pid, (unsigned) cpuset_size, cpuset, errstr);
 	assert(ret_size <= (int) cpuset_size);
 
-	printf("sched_getaffinity(%d, %u, [", pid, cpuset_size);
+	pidns_print_leader();
+	printf("sched_getaffinity(%d%s, %u, [", pid, pid_str, cpuset_size);
 	const char *sep;
 	unsigned int i, cpu;
 	for (i = 0, cpu = 0, sep = ""; i < (unsigned) ret_size * 8; ++i) {
@@ -85,8 +93,9 @@ main(void)
 	CPU_SET_S(cpu, cpuset_size, cpuset);
 	if (setaffinity(pid, cpuset_size, cpuset))
 		perror_msg_and_skip("sched_setaffinity");
-	printf("sched_setaffinity(%d, %u, [%u]) = 0\n",
-	       pid, cpuset_size, cpu);
+	pidns_print_leader();
+	printf("sched_setaffinity(%d%s, %u, [%u]) = 0\n",
+	       pid, pid_str, cpuset_size, cpu);
 
 	const unsigned int big_size = cpuset_size < 128 ? 128 : cpuset_size * 2;
 	cpuset = tail_alloc(big_size);
@@ -95,7 +104,8 @@ main(void)
 		perror_msg_and_fail("sched_getaffinity(%d, %u, %p) = %s\n",
 				    pid, big_size, cpuset, errstr);
 	assert(ret_size <= (int) big_size);
-	printf("sched_getaffinity(%d, %u, [", pid, big_size);
+	pidns_print_leader();
+	printf("sched_getaffinity(%d%s, %u, [", pid, pid_str, big_size);
 	for (i = 0, sep = ""; i < (unsigned) ret_size * 8; ++i) {
 		if (CPU_ISSET_S(i, (unsigned) ret_size, cpuset)) {
 			printf("%s%u", sep, i);
@@ -104,6 +114,7 @@ main(void)
 	}
 	printf("]) = %s\n", errstr);
 
+	pidns_print_leader();
 	puts("+++ exited with 0 +++");
 	return 0;
 }
diff --git a/tests/sched_xetattr--pidns-translation.c b/tests/sched_xetattr--pidns-translation.c
new file mode 100644
index 00000000..c152023d
--- /dev/null
+++ b/tests/sched_xetattr--pidns-translation.c
@@ -0,0 +1,2 @@
+#define PIDNS_TRANSLATION
+#include "sched_xetattr.c"
diff --git a/tests/sched_xetattr.c b/tests/sched_xetattr.c
index c63d7a80..4a76b2d6 100644
--- a/tests/sched_xetattr.c
+++ b/tests/sched_xetattr.c
@@ -15,6 +15,7 @@
 # include <stdio.h>
 # include <sched.h>
 # include <unistd.h>
+# include "pidns.h"
 # include "sched_attr.h"
 # include "xlat.h"
 # include "xlat/schedulers.h"
@@ -41,6 +42,8 @@ sys_sched_setattr(kernel_ulong_t pid, kernel_ulong_t attr, kernel_ulong_t flags)
 int
 main(void)
 {
+	PIDNS_TEST_INIT;
+
 	static const kernel_ulong_t bogus_pid =
 		(kernel_ulong_t) 0xdefacedfacefeedULL;
 	static const kernel_ulong_t bogus_size =
@@ -48,20 +51,28 @@ main(void)
 	static const kernel_ulong_t bogus_flags =
 		(kernel_ulong_t) 0xdefaceddeadc0deULL;
 
+	const int pid = getpid();
+	const char *pid_str = pidns_pid2str(PT_TGID);
+
 	TAIL_ALLOC_OBJECT_CONST_PTR(struct sched_attr, attr);
 	TAIL_ALLOC_OBJECT_CONST_PTR(unsigned int, psize);
 	void *const efault = attr + 1;
 
-	sys_sched_getattr(0, 0, 0, 0);
-	printf("sched_getattr(0, NULL, 0, 0) = %s\n", errstr);
+	sys_sched_getattr(pid, 0, 0, 0);
+	pidns_print_leader();
+	printf("sched_getattr(%d%s, NULL, 0, 0) = %s\n",
+		pid, pid_str, errstr);
 
 	sys_sched_getattr(0, (unsigned long) attr, 0, 0);
+	pidns_print_leader();
 	printf("sched_getattr(0, %p, 0, 0) = %s\n", attr, errstr);
 
 	sys_sched_getattr(bogus_pid, 0, 0, 0);
+	pidns_print_leader();
 	printf("sched_getattr(%d, NULL, 0, 0) = %s\n", (int) bogus_pid, errstr);
 
 	sys_sched_getattr(-1U, (unsigned long) attr, bogus_size, bogus_flags);
+	pidns_print_leader();
 	printf("sched_getattr(-1, %p, %s%u, %u) = %s\n",
 	       attr,
 # if defined __arm64__ || defined __aarch64__
@@ -72,11 +83,13 @@ main(void)
 	       (unsigned) bogus_size, (unsigned) bogus_flags, errstr);
 
 	sys_sched_getattr(0, (unsigned long) efault, SCHED_ATTR_MIN_SIZE, 0);
+	pidns_print_leader();
 	printf("sched_getattr(0, %p, %u, 0) = %s\n",
 	       efault, (unsigned) SCHED_ATTR_MIN_SIZE, errstr);
 
 	if (sys_sched_getattr(0, (unsigned long) attr, SCHED_ATTR_MIN_SIZE, 0))
 		perror_msg_and_skip("sched_getattr");
+	pidns_print_leader();
 	printf("sched_getattr(0, {size=%u, sched_policy=", attr->size);
 	printxval(schedulers, attr->sched_policy, NULL);
 	printf(", sched_flags=%s, sched_nice=%d, sched_priority=%u"
@@ -91,11 +104,13 @@ main(void)
 	       (unsigned) SCHED_ATTR_MIN_SIZE);
 
 	sys_sched_getattr(0, (unsigned long) efault, sizeof(*attr), 0);
+	pidns_print_leader();
 	printf("sched_getattr(0, %p, %u, 0) = %s\n",
 	       efault, (unsigned) sizeof(*attr), errstr);
 
 	if (sys_sched_getattr(0, (unsigned long) attr, sizeof(*attr), 0))
 		perror_msg_and_skip("sched_getattr");
+	pidns_print_leader();
 	printf("sched_getattr(0, {size=%u, sched_policy=", attr->size);
 	printxval(schedulers, attr->sched_policy, NULL);
 	printf(", sched_flags=%s, sched_nice=%d, sched_priority=%u"
@@ -121,11 +136,13 @@ main(void)
 			  F8ILL_KULONG_MASK | sizeof(*attr), F8ILL_KULONG_MASK);
 # if defined __arm64__ || defined __aarch64__
 	if (rc) {
+		pidns_print_leader();
 		printf("sched_getattr(0, %p, 0xffffffff<<32|%u, 0) = %s\n",
 		       attr, (unsigned) sizeof(*attr), errstr);
 	} else
 # endif
 	{
+		pidns_print_leader();
 		printf("sched_getattr(0, {size=%u, sched_policy=", attr->size);
 		printxval(schedulers, attr->sched_policy, NULL);
 		printf(", sched_flags=%s, sched_nice=%d, sched_priority=%u"
@@ -146,13 +163,16 @@ main(void)
 	}
 
 	sys_sched_setattr(bogus_pid, 0, 0);
+	pidns_print_leader();
 	printf("sched_setattr(%d, NULL, 0) = %s\n", (int) bogus_pid, errstr);
 
 	attr->sched_flags |= 1;
 
-	if (sys_sched_setattr(0, (unsigned long) attr, 0))
+	if (sys_sched_setattr(pid, (unsigned long) attr, 0))
 		perror_msg_and_skip("sched_setattr");
-	printf("sched_setattr(0, {size=%u, sched_policy=", attr->size);
+	pidns_print_leader();
+	printf("sched_setattr(%d%s, {size=%u, sched_policy=",
+		pid, pid_str, attr->size);
 	printxval(schedulers, attr->sched_policy, NULL);
 	printf(", sched_flags=%s, sched_nice=%d, sched_priority=%u"
 	       ", sched_runtime=%" PRIu64 ", sched_deadline=%" PRIu64
@@ -172,6 +192,7 @@ main(void)
 
 	sys_sched_setattr(F8ILL_KULONG_MASK, (unsigned long) attr,
 			  F8ILL_KULONG_MASK);
+	pidns_print_leader();
 	printf("sched_setattr(0, {size=%u, sched_policy=", attr->size);
 	printxval(schedulers, attr->sched_policy, NULL);
 	printf(", sched_flags=%s, sched_nice=%d, sched_priority=%u"
@@ -193,11 +214,13 @@ main(void)
 	*psize = attr->size;
 
 	sys_sched_setattr(0, (unsigned long) psize, 0);
+	pidns_print_leader();
 	printf("sched_setattr(0, %p, 0) = %s\n", psize, errstr);
 
 	attr->size = 0;
 
 	sys_sched_setattr(0, (unsigned long) attr, 0);
+	pidns_print_leader();
 	printf("sched_setattr(0, {size=%u, sched_policy=", attr->size);
 	printxval(schedulers, attr->sched_policy, NULL);
 	printf(", sched_flags=%s, sched_nice=%d, sched_priority=%u"
@@ -213,12 +236,14 @@ main(void)
 	attr->size = 1;
 
 	sys_sched_setattr(0, (unsigned long) attr, 0);
+	pidns_print_leader();
 	printf("sched_setattr(0, {size=%u} => {size=%u}, 0) = %s\n",
 	       1, attr->size, errstr);
 
 	attr->size = SCHED_ATTR_MIN_SIZE - 1;
 
 	sys_sched_setattr(0, (unsigned long) attr, 0);
+	pidns_print_leader();
 	printf("sched_setattr(0, {size=%u} => {size=%u}, 0) = %s\n",
 	       SCHED_ATTR_MIN_SIZE - 1, attr->size, errstr);
 
@@ -232,6 +257,7 @@ main(void)
 	attr->sched_period = 0xded1ca7edda7aca7ULL;
 
 	sys_sched_setattr(bogus_pid, (unsigned long) attr, bogus_flags);
+	pidns_print_leader();
 	printf("sched_setattr(%d, {size=%u, sched_policy=%#x /* SCHED_??? */, "
 	       "sched_flags=%#" PRIx64 " /* SCHED_FLAG_??? */, "
 	       "sched_nice=%d, sched_priority=%u, sched_runtime=%" PRIu64 ", "
@@ -274,6 +300,7 @@ main(void)
 	attr->sched_period = 0xded1ca7edda7aca7ULL;
 
 	sys_sched_setattr(bogus_pid, (unsigned long) attr, bogus_flags);
+	pidns_print_leader();
 	printf("sched_setattr(%d, {size=%u, sched_policy=%#x /* SCHED_??? */, "
 	       "sched_flags=SCHED_FLAG_RESET_ON_FORK|SCHED_FLAG_RECLAIM|"
 	       "SCHED_FLAG_DL_OVERRUN|0x80, "
@@ -296,11 +323,13 @@ main(void)
 		const kernel_ulong_t ill = f8ill_ptr_to_kulong(attr);
 
 		sys_sched_getattr(0, ill, sizeof(*attr), 0);
+		pidns_print_leader();
 		printf("sched_getattr(0, %#llx, %u, 0) = %s\n",
 		       (unsigned long long) ill, (unsigned) sizeof(*attr),
 		       errstr);
 
 		sys_sched_setattr(0, ill, 0);
+		pidns_print_leader();
 		printf("sched_setattr(0, %#llx, 0) = %s\n",
 		       (unsigned long long) ill, errstr);
 	}
@@ -310,6 +339,7 @@ main(void)
 	attr->sched_flags = 0x8fULL;
 
 	sys_sched_setattr(bogus_pid, (unsigned long) attr, bogus_flags);
+	pidns_print_leader();
 	printf("sched_setattr(%d, {size=%u, "
 	       "sched_flags=SCHED_FLAG_RESET_ON_FORK|SCHED_FLAG_RECLAIM|"
 	       "SCHED_FLAG_DL_OVERRUN|SCHED_FLAG_KEEP_POLICY|0x80, "
@@ -329,11 +359,13 @@ main(void)
 		const kernel_ulong_t ill = f8ill_ptr_to_kulong(attr);
 
 		sys_sched_getattr(0, ill, sizeof(*attr), 0);
+		pidns_print_leader();
 		printf("sched_getattr(0, %#llx, %u, 0) = %s\n",
 		       (unsigned long long) ill, (unsigned) sizeof(*attr),
 		       errstr);
 
 		sys_sched_setattr(0, ill, 0);
+		pidns_print_leader();
 		printf("sched_setattr(0, %#llx, 0) = %s\n",
 		       (unsigned long long) ill, errstr);
 	}
@@ -342,6 +374,7 @@ main(void)
 	attr->sched_flags = 0xe7ULL;
 
 	sys_sched_setattr(bogus_pid, (unsigned long) attr, bogus_flags);
+	pidns_print_leader();
 	printf("sched_setattr(%d, {size=%u, sched_policy=%#x /* SCHED_??? */, "
 	       "sched_flags=SCHED_FLAG_RESET_ON_FORK|SCHED_FLAG_RECLAIM|"
 	       "SCHED_FLAG_DL_OVERRUN|SCHED_FLAG_UTIL_CLAMP_MIN"
@@ -365,11 +398,13 @@ main(void)
 		const kernel_ulong_t ill = f8ill_ptr_to_kulong(attr);
 
 		sys_sched_getattr(0, ill, sizeof(*attr), 0);
+		pidns_print_leader();
 		printf("sched_getattr(0, %#llx, %u, 0) = %s\n",
 		       (unsigned long long) ill, (unsigned) sizeof(*attr),
 		       errstr);
 
 		sys_sched_setattr(0, ill, 0);
+		pidns_print_leader();
 		printf("sched_setattr(0, %#llx, 0) = %s\n",
 		       (unsigned long long) ill, errstr);
 	}
@@ -377,6 +412,7 @@ main(void)
 	attr->sched_flags = 0xcaffee90LL;
 
 	sys_sched_setattr(bogus_pid, (unsigned long) attr, bogus_flags);
+	pidns_print_leader();
 	printf("sched_setattr(%d, {size=%u, sched_flags=SCHED_FLAG_KEEP_PARAMS"
 	       "|0xcaffee80, sched_util_min=%u, sched_util_max=%u}, %u) = %s\n",
 	       (int) bogus_pid,
@@ -389,15 +425,18 @@ main(void)
 		const kernel_ulong_t ill = f8ill_ptr_to_kulong(attr);
 
 		sys_sched_getattr(0, ill, sizeof(*attr), 0);
+		pidns_print_leader();
 		printf("sched_getattr(0, %#llx, %u, 0) = %s\n",
 		       (unsigned long long) ill, (unsigned) sizeof(*attr),
 		       errstr);
 
 		sys_sched_setattr(0, ill, 0);
+		pidns_print_leader();
 		printf("sched_setattr(0, %#llx, 0) = %s\n",
 		       (unsigned long long) ill, errstr);
 	}
 
+	pidns_print_leader();
 	puts("+++ exited with 0 +++");
 	return 0;
 }
diff --git a/tests/sched_xetparam--pidns-translation.c b/tests/sched_xetparam--pidns-translation.c
new file mode 100644
index 00000000..9fb3e579
--- /dev/null
+++ b/tests/sched_xetparam--pidns-translation.c
@@ -0,0 +1,2 @@
+#define PIDNS_TRANSLATION
+#include "sched_xetparam.c"
diff --git a/tests/sched_xetparam.c b/tests/sched_xetparam.c
index de3915b2..aa9c68cc 100644
--- a/tests/sched_xetparam.c
+++ b/tests/sched_xetparam.c
@@ -7,6 +7,7 @@
 
 #include "tests.h"
 #include "scno.h"
+# include "pidns.h"
 
 #if defined __NR_sched_getparam && defined __NR_sched_setparam
 
@@ -17,18 +18,27 @@
 int
 main(void)
 {
+	PIDNS_TEST_INIT;
+
 	struct sched_param *const param =
 		tail_alloc(sizeof(struct sched_param));
 
-	long rc = syscall(__NR_sched_getparam, 0, param);
-	printf("sched_getparam(0, [%d]) = %ld\n",
-	       param->sched_priority, rc);
+	const int pid = getpid();
+	const char *pid_str = pidns_pid2str(PT_TGID);
+
+	long rc = syscall(__NR_sched_getparam, pid, param);
+	pidns_print_leader();
+	printf("sched_getparam(%d%s, [%d]) = %ld\n",
+	       pid, pid_str, param->sched_priority, rc);
 
 	param->sched_priority = -1;
-	rc = syscall(__NR_sched_setparam, 0, param);
-	printf("sched_setparam(0, [%d]) = %ld %s (%m)\n",
+	rc = syscall(__NR_sched_setparam, pid, param);
+	pidns_print_leader();
+	printf("sched_setparam(%d%s, [%d]) = %ld %s (%m)\n",
+	       pid, pid_str,
 	       param->sched_priority, rc, errno2name());
 
+	pidns_print_leader();
 	puts("+++ exited with 0 +++");
 	return 0;
 }
diff --git a/tests/sched_xetscheduler--pidns-translation.c b/tests/sched_xetscheduler--pidns-translation.c
new file mode 100644
index 00000000..78b794b2
--- /dev/null
+++ b/tests/sched_xetscheduler--pidns-translation.c
@@ -0,0 +1,2 @@
+#define PIDNS_TRANSLATION
+#include "sched_xetscheduler.c"
diff --git a/tests/sched_xetscheduler.c b/tests/sched_xetscheduler.c
index 047e8676..91b5e32d 100644
--- a/tests/sched_xetscheduler.c
+++ b/tests/sched_xetscheduler.c
@@ -7,6 +7,7 @@
 
 #include "tests.h"
 #include "scno.h"
+#include "pidns.h"
 
 #if defined __NR_sched_getscheduler && defined __NR_sched_setscheduler
 
@@ -17,8 +18,13 @@
 int
 main(void)
 {
+	PIDNS_TEST_INIT;
+
 	TAIL_ALLOC_OBJECT_CONST_PTR(struct sched_param, param);
-	long rc = syscall(__NR_sched_getscheduler, 0);
+	const int pid = getpid();
+	const char *pid_str = pidns_pid2str(PT_TGID);
+
+	long rc = syscall(__NR_sched_getscheduler, pid);
 	const char *scheduler;
 	switch (rc) {
 		case SCHED_FIFO:
@@ -50,33 +56,43 @@ main(void)
 		default:
 			scheduler = "SCHED_OTHER";
 	}
-	printf("sched_getscheduler(0) = %ld (%s)\n",
-	       rc, scheduler);
+	pidns_print_leader();
+	printf("sched_getscheduler(%d%s) = %ld (%s)\n",
+	       pid, pid_str, rc, scheduler);
 
 	rc = syscall(__NR_sched_getscheduler, -1);
+	pidns_print_leader();
 	printf("sched_getscheduler(-1) = %s\n", sprintrc(rc));
 
 	param->sched_priority = -1;
 
-	rc = syscall(__NR_sched_setscheduler, 0, SCHED_FIFO, NULL);
-	printf("sched_setscheduler(0, SCHED_FIFO, NULL) = %s\n", sprintrc(rc));
+	rc = syscall(__NR_sched_setscheduler, pid, SCHED_FIFO, NULL);
+	pidns_print_leader();
+	printf("sched_setscheduler(%d%s, SCHED_FIFO, NULL) = %s\n",
+	       pid, pid_str, sprintrc(rc));
 
-	rc = syscall(__NR_sched_setscheduler, 0, SCHED_FIFO, param + 1);
-	printf("sched_setscheduler(0, SCHED_FIFO, %p) = %s\n", param + 1,
-	       sprintrc(rc));
+	rc = syscall(__NR_sched_setscheduler, pid, SCHED_FIFO, param + 1);
+	pidns_print_leader();
+	printf("sched_setscheduler(%d%s, SCHED_FIFO, %p) = %s\n",
+	       pid, pid_str, param + 1, sprintrc(rc));
 
-	rc = syscall(__NR_sched_setscheduler, 0, 0xfaceda7a, param);
-	printf("sched_setscheduler(0, %#x /* SCHED_??? */, [%d]) = %s\n",
-	       0xfaceda7a, param->sched_priority, sprintrc(rc));
+	rc = syscall(__NR_sched_setscheduler, pid, 0xfaceda7a, param);
+	pidns_print_leader();
+	printf("sched_setscheduler(%d%s, %#x /* SCHED_??? */, [%d]) = %s\n",
+	       pid, pid_str, 0xfaceda7a,
+	       param->sched_priority, sprintrc(rc));
 
 	rc = syscall(__NR_sched_setscheduler, -1, SCHED_FIFO, param);
+	pidns_print_leader();
 	printf("sched_setscheduler(-1, SCHED_FIFO, [%d]) = %s\n",
 	       param->sched_priority, sprintrc(rc));
 
-	rc = syscall(__NR_sched_setscheduler, 0, SCHED_FIFO, param);
-	printf("sched_setscheduler(0, SCHED_FIFO, [%d]) = %s\n",
-	       param->sched_priority, sprintrc(rc));
+	rc = syscall(__NR_sched_setscheduler, pid, SCHED_FIFO, param);
+	pidns_print_leader();
+	printf("sched_setscheduler(%d%s, SCHED_FIFO, [%d]) = %s\n",
+	       pid, pid_str, param->sched_priority, sprintrc(rc));
 
+	pidns_print_leader();
 	puts("+++ exited with 0 +++");
 	return 0;
 }
diff --git a/tests/signal_receive--pidns-translation.c b/tests/signal_receive--pidns-translation.c
new file mode 100644
index 00000000..b4e3b2f8
--- /dev/null
+++ b/tests/signal_receive--pidns-translation.c
@@ -0,0 +1,2 @@
+#define PIDNS_TRANSLATION
+#include "signal_receive.c"
diff --git a/tests/signal_receive.c b/tests/signal_receive.c
index ad3b4ebd..70441a9e 100644
--- a/tests/signal_receive.c
+++ b/tests/signal_receive.c
@@ -8,6 +8,7 @@
  */
 
 #include "tests.h"
+#include "pidns.h"
 #include <signal.h>
 #include <stdio.h>
 #include <unistd.h>
@@ -26,10 +27,13 @@ handler(int sig, siginfo_t *info, void *ucontext)
 int
 main(void)
 {
+	PIDNS_TEST_INIT;
+
 	static const char prefix[] = "KERNEL BUG";
 	int printed = 0;
 
 	const int pid = getpid();
+	const char *pid_str = pidns_pid2str(PT_TGID);
 	const int uid = geteuid();
 
 	for (int sig = 1; sig <= 31; ++sig) {
@@ -73,10 +77,13 @@ main(void)
 		const int e_pid = s_pid;
 		const int e_uid = s_uid;
 #endif
-		printf("kill(%d, %s) = 0\n", pid, signal2name(sig));
-		printf("--- %s {si_signo=%s, si_code=SI_USER, si_pid=%d"
+		pidns_print_leader();
+		printf("kill(%d%s, %s) = 0\n", pid, pid_str, signal2name(sig));
+		pidns_print_leader();
+		printf("--- %s {si_signo=%s, si_code=SI_USER, si_pid=%d%s"
 		       ", si_uid=%d} ---\n",
-		       signal2name(sig), signal2name(e_sig), e_pid, e_uid);
+		       signal2name(sig), signal2name(e_sig),
+		       e_pid, pid_str, e_uid);
 
 		if (s_code || sig != s_sig || pid != s_pid || uid != s_uid) {
 			/*
@@ -91,11 +98,11 @@ main(void)
 			}
 			fprintf(stderr,
 				"%s: expected: si_signo=%d, si_code=%d"
-				", si_pid=%d, si_uid=%d\n"
+				", si_pid=%d%s, si_uid=%d\n"
 				"%s: received: si_signo=%d, si_code=%d"
-				", si_pid=%d, si_uid=%d\n",
-				prefix, sig, SI_USER, pid, uid,
-				prefix, sig, s_code, s_pid, s_uid);
+				", si_pid=%d%s, si_uid=%d\n",
+				prefix, sig, SI_USER, pid, pid_str, uid,
+				prefix, sig, s_code, s_pid, pid_str, s_uid);
 		}
 	}
 
@@ -104,6 +111,7 @@ main(void)
 			"*** PLEASE FIX THE KERNEL ***\n", prefix);
 	}
 
+	pidns_print_leader();
 	puts("+++ exited with 0 +++");
 	return 0;
 }
diff --git a/tests/so_peercred--pidns-translation.c b/tests/so_peercred--pidns-translation.c
new file mode 100644
index 00000000..402bbcfe
--- /dev/null
+++ b/tests/so_peercred--pidns-translation.c
@@ -0,0 +1,2 @@
+#define PIDNS_TRANSLATION
+#include "so_peercred.c"
diff --git a/tests/so_peercred.c b/tests/so_peercred.c
index 151bb175..20188bdb 100644
--- a/tests/so_peercred.c
+++ b/tests/so_peercred.c
@@ -9,6 +9,7 @@
  */
 
 #include "tests.h"
+#include "pidns.h"
 
 #include <stddef.h>
 #include <stdio.h>
@@ -53,6 +54,8 @@ so_str(void)
 int
 main(void)
 {
+	PIDNS_TEST_INIT;
+
 	TAIL_ALLOC_OBJECT_CONST_PTR(struct ucred, peercred);
 	TAIL_ALLOC_OBJECT_CONST_PTR(socklen_t, len);
 
@@ -75,6 +78,8 @@ main(void)
 	struct ucred *const gid_truncated =
 		tail_alloc(sizeof_gid_truncated);
 
+	const char *pid_str = pidns_pid2str(PT_TGID);
+
 	int sv[2];
 	if (socketpair(AF_UNIX, SOCK_STREAM, 0, sv))
                 perror_msg_and_skip("socketpair AF_UNIX SOCK_STREAM");
@@ -82,8 +87,10 @@ main(void)
 	/* classic getsockopt */
 	*len = sizeof(*peercred);
 	get_peercred(sv[0], peercred, len);
+	pidns_print_leader();
 	printf("getsockopt(%d, %s", sv[0], so_str());
 	PRINT_FIELD_D(", {", *peercred, pid);
+	printf("%s", pid_str);
 	PRINT_FIELD_UID(", ", *peercred, uid);
 	PRINT_FIELD_UID(", ", *peercred, gid);
 	printf("}, [%d]) = %s\n", *len, errstr);
@@ -91,14 +98,17 @@ main(void)
 	/* getsockopt with zero optlen */
 	*len = 0;
 	get_peercred(sv[0], peercred, len);
+	pidns_print_leader();
 	printf("getsockopt(%d, %s, %p, [0]) = %s\n",
 	       sv[0], so_str(), peercred, errstr);
 
 	/* getsockopt with optlen larger than necessary - shortened */
 	*len = sizeof(*peercred) + 1;
 	get_peercred(sv[0], peercred, len);
+	pidns_print_leader();
 	printf("getsockopt(%d, %s", sv[0], so_str());
 	PRINT_FIELD_D(", {", *peercred, pid);
+	printf("%s", pid_str);
 	PRINT_FIELD_UID(", ", *peercred, uid);
 	PRINT_FIELD_UID(", ", *peercred, gid);
 	printf("}, [%u->%d]) = %s\n",
@@ -110,6 +120,7 @@ main(void)
 	 */
 	*len = sizeof_pid_truncated;
 	get_peercred(sv[0], pid_truncated, len);
+	pidns_print_leader();
 	printf("getsockopt(%d, %s, {pid=", sv[0], so_str());
 	print_quoted_hex(pid_truncated, *len);
 	printf("}, [%d]) = %s\n", *len, errstr);
@@ -120,8 +131,10 @@ main(void)
 	 */
 	*len = sizeof_pid;
 	get_peercred(sv[0], pid, len);
+	pidns_print_leader();
 	printf("getsockopt(%d, %s", sv[0], so_str());
 	PRINT_FIELD_D(", {", *pid, pid);
+	printf("%s", pid_str);
 	printf("}, [%d]) = %s\n", *len, errstr);
 
 	/*
@@ -136,8 +149,10 @@ main(void)
 	 * to struct ucred.pid field.
 	 */
 	memcpy(uid, uid_truncated, sizeof_uid_truncated);
+	pidns_print_leader();
 	printf("getsockopt(%d, %s", sv[0], so_str());
 	PRINT_FIELD_D(", {", *uid, pid);
+	printf("%s", pid_str);
 	printf(", uid=");
 	print_quoted_hex(&uid->uid, sizeof_uid_truncated -
 				    offsetof(struct ucred, uid));
@@ -149,8 +164,10 @@ main(void)
 	 */
 	*len = sizeof_uid;
 	get_peercred(sv[0], uid, len);
+	pidns_print_leader();
 	printf("getsockopt(%d, %s", sv[0], so_str());
 	PRINT_FIELD_D(", {", *uid, pid);
+	printf("%s", pid_str);
 	PRINT_FIELD_UID(", ", *uid, uid);
 	printf("}, [%d]) = %s\n", *len, errstr);
 
@@ -166,8 +183,10 @@ main(void)
 	 * to struct ucred.pid and struct ucred.uid fields.
 	 */
 	memcpy(peercred, gid_truncated, sizeof_gid_truncated);
+	pidns_print_leader();
 	printf("getsockopt(%d, %s", sv[0], so_str());
 	PRINT_FIELD_D(", {", *peercred, pid);
+	printf("%s", pid_str);
 	PRINT_FIELD_UID(", ", *peercred, uid);
 	printf(", gid=");
 	print_quoted_hex(&peercred->gid, sizeof_gid_truncated -
@@ -177,14 +196,17 @@ main(void)
 	/* getsockopt optval EFAULT */
 	*len = sizeof(*peercred);
 	get_peercred(sv[0], &peercred->uid, len);
+	pidns_print_leader();
 	printf("getsockopt(%d, %s, %p, [%d]) = %s\n",
 	       sv[0], so_str(), &peercred->uid, *len, errstr);
 
 	/* getsockopt optlen EFAULT */
 	get_peercred(sv[0], peercred, len + 1);
+	pidns_print_leader();
 	printf("getsockopt(%d, %s, %p, %p) = %s\n",
 	       sv[0], so_str(), peercred, len + 1, errstr);
 
+	pidns_print_leader();
 	puts("+++ exited with 0 +++");
 	return 0;
 }
diff --git a/tests/xet_robust_list--pidns-translation.c b/tests/xet_robust_list--pidns-translation.c
new file mode 100644
index 00000000..e0477267
--- /dev/null
+++ b/tests/xet_robust_list--pidns-translation.c
@@ -0,0 +1,2 @@
+#define PIDNS_TRANSLATION
+#include "xet_robust_list.c"
diff --git a/tests/xet_robust_list.c b/tests/xet_robust_list.c
index 43239c8b..b5751b0a 100644
--- a/tests/xet_robust_list.c
+++ b/tests/xet_robust_list.c
@@ -8,6 +8,7 @@
 
 #include "tests.h"
 #include "scno.h"
+#include "pidns.h"
 
 #if defined __NR_get_robust_list && defined __NR_set_robust_list
 
@@ -30,27 +31,36 @@ sprintaddr(void *addr)
 int
 main(void)
 {
+	PIDNS_TEST_INIT;
+
 	const pid_t pid = getpid();
+	const char *pid_str = pidns_pid2str(PT_TGID);
 	const long long_pid = (unsigned long) (0xdeadbeef00000000LL | pid);
 	TAIL_ALLOC_OBJECT_CONST_PTR(void *, p_head);
 	TAIL_ALLOC_OBJECT_CONST_PTR(size_t, p_len);
 
 	if (syscall(__NR_get_robust_list, long_pid, p_head, p_len))
 		perror_msg_and_skip("get_robust_list");
-	printf("get_robust_list(%d, [%s], [%lu]) = 0\n",
-	       (int) pid, sprintaddr(*p_head), (unsigned long) *p_len);
+	pidns_print_leader();
+	printf("get_robust_list(%d%s, [%s], [%lu]) = 0\n",
+	       pid, pid_str, sprintaddr(*p_head),
+	       (unsigned long) *p_len);
 
 	void *head = tail_alloc(*p_len);
 	if (syscall(__NR_set_robust_list, head, *p_len))
 		perror_msg_and_skip("set_robust_list");
+	pidns_print_leader();
 	printf("set_robust_list(%p, %lu) = 0\n",
 	       head, (unsigned long) *p_len);
 
 	if (syscall(__NR_get_robust_list, long_pid, p_head, p_len))
 		perror_msg_and_skip("get_robust_list");
-	printf("get_robust_list(%d, [%s], [%lu]) = 0\n",
-	       (int) pid, sprintaddr(*p_head), (unsigned long) *p_len);
+	pidns_print_leader();
+	printf("get_robust_list(%d%s, [%s], [%lu]) = 0\n",
+	       pid, pid_str, sprintaddr(*p_head),
+	       (unsigned long) *p_len);
 
+	pidns_print_leader();
 	puts("+++ exited with 0 +++");
 	return 0;
 }
diff --git a/tests/xetpgid--pidns-translation.c b/tests/xetpgid--pidns-translation.c
new file mode 100644
index 00000000..b6469628
--- /dev/null
+++ b/tests/xetpgid--pidns-translation.c
@@ -0,0 +1,2 @@
+#define PIDNS_TRANSLATION
+#include "xetpgid.c"
diff --git a/tests/xetpgid.c b/tests/xetpgid.c
index 9b070af2..411edfc7 100644
--- a/tests/xetpgid.c
+++ b/tests/xetpgid.c
@@ -10,6 +10,7 @@
 
 #include "tests.h"
 #include "scno.h"
+#include "pidns.h"
 
 #if defined __NR_getpgid && defined __NR_setpgid
 
@@ -19,13 +20,21 @@
 int
 main(void)
 {
-	const int pid = getpid();
-	long rc = syscall(__NR_getpgid, F8ILL_KULONG_MASK | pid);
-	printf("getpgid(%d) = %ld\n", pid, rc);
-
-	rc = syscall(__NR_setpgid, F8ILL_KULONG_MASK, F8ILL_KULONG_MASK | pid);
-	printf("setpgid(0, %d) = %ld\n", pid, rc);
+	PIDNS_TEST_INIT;
 
+	const int pid = getpid();
+	long pgid = syscall(__NR_getpgid, F8ILL_KULONG_MASK | pid);
+	pidns_print_leader();
+	printf("getpgid(%d%s) = %ld%s\n", pid, pidns_pid2str(PT_TGID),
+		pgid, pidns_pid2str(PT_PGID));
+
+	long rc = syscall(__NR_setpgid, F8ILL_KULONG_MASK,
+		F8ILL_KULONG_MASK | pgid);
+	pidns_print_leader();
+	printf("setpgid(0, %ld%s) = %s\n", pgid, pidns_pid2str(PT_PGID),
+		sprintrc(rc));
+
+	pidns_print_leader();
 	puts("+++ exited with 0 +++");
 	return 0;
 }
diff --git a/tests/xetpriority--pidns-translation.c b/tests/xetpriority--pidns-translation.c
new file mode 100644
index 00000000..c93669cb
--- /dev/null
+++ b/tests/xetpriority--pidns-translation.c
@@ -0,0 +1,2 @@
+#define PIDNS_TRANSLATION
+#include "xetpriority.c"
diff --git a/tests/xetpriority.c b/tests/xetpriority.c
index 2d61bd10..dd38217d 100644
--- a/tests/xetpriority.c
+++ b/tests/xetpriority.c
@@ -7,6 +7,7 @@
 
 #include "tests.h"
 #include "scno.h"
+#include "pidns.h"
 
 #if defined __NR_getpriority && defined __NR_setpriority
 
@@ -17,15 +18,30 @@
 int
 main(void)
 {
+	PIDNS_TEST_INIT;
+
 	const int pid = getpid();
+	const int pgid = getpgid(0);
+
 	long rc = syscall(__NR_getpriority, PRIO_PROCESS,
 			  F8ILL_KULONG_MASK | pid);
-	printf("getpriority(PRIO_PROCESS, %d) = %ld\n", pid, rc);
+	pidns_print_leader();
+	printf("getpriority(PRIO_PROCESS, %d%s) = %ld\n",
+		pid, pidns_pid2str(PT_TGID), rc);
 
 	rc = syscall(__NR_setpriority, PRIO_PROCESS,
 		     F8ILL_KULONG_MASK | pid, F8ILL_KULONG_MASK);
-	printf("setpriority(PRIO_PROCESS, %d, 0) = %s\n", pid, sprintrc(rc));
+	pidns_print_leader();
+	printf("setpriority(PRIO_PROCESS, %d%s, 0) = %s\n",
+		pid, pidns_pid2str(PT_TGID), sprintrc(rc));
+
+	rc = syscall(__NR_getpriority, PRIO_PGRP,
+			  F8ILL_KULONG_MASK | pgid);
+	pidns_print_leader();
+	printf("getpriority(PRIO_PGRP, %d%s) = %ld\n",
+		pgid, pidns_pid2str(PT_PGID), rc);
 
+	pidns_print_leader();
 	puts("+++ exited with 0 +++");
 	return 0;
 }
-- 
2.27.0


From uzonyi.akos at gmail.com  Thu Aug 13 15:32:38 2020
From: uzonyi.akos at gmail.com (=?UTF-8?q?=C3=81kos=20Uzonyi?=)
Date: Thu, 13 Aug 2020 17:32:38 +0200
Subject: [RFC PATCH 0/4] [PIDNS] Trie and pidns-cache tests
Message-ID: <20200813153242.94742-1-uzonyi.akos@gmail.com>

From: Uzonyi ?kos <uzonyi.akos at gmail.com>

In the last series, while refactoring trie I introduced a bug (tries with 64
bits key were returning 0 always), which caused pidns cache not working. The
first patch in this series fixes it. Also ns_id_size was wrong, which is fixed
by the second patch.

The last two patches add tests, so these bugs are caught by the test suite. The
first one checks whether pidns tranlsation is fast enough (executes 200 getpid
calls, and expects it to complete under 1s). The second one (which is not yet
complete) check whether trie_get is returning the expected value.

The reason I'm sending it is to have some feedback whether you like the
approach to these (little bit odd) tests. In the first one, I'm not sure if
it's OK to use 200 for SYSCALL_COUNT, which is based on my system's
performance. In the second one is it's OK to add ../trie.c ../trie.h to
libtests_a_SOURCES?

?kos Uzonyi (4):
  Fix trie
  Fix ns_id_size
  Test pidns translation cache
  Add test for trie

 pidns.c                |  2 +-
 tests/.gitignore       |  2 ++
 tests/Makefile.am      |  5 ++++
 tests/pidns-cache.c    | 29 +++++++++++++++++++++
 tests/pidns-cache.test | 23 +++++++++++++++++
 tests/trie.c           | 57 ++++++++++++++++++++++++++++++++++++++++++
 tests/trie.test        | 12 +++++++++
 trie.c                 | 10 +++++---
 8 files changed, 136 insertions(+), 4 deletions(-)
 create mode 100644 tests/pidns-cache.c
 create mode 100755 tests/pidns-cache.test
 create mode 100644 tests/trie.c
 create mode 100755 tests/trie.test

--
2.28.0


From uzonyi.akos at gmail.com  Thu Aug 13 15:32:39 2020
From: uzonyi.akos at gmail.com (=?UTF-8?q?=C3=81kos=20Uzonyi?=)
Date: Thu, 13 Aug 2020 17:32:39 +0200
Subject: [RFC PATCH 1/4] Fix trie
In-Reply-To: <20200813153242.94742-1-uzonyi.akos@gmail.com>
References: <20200813153242.94742-1-uzonyi.akos@gmail.com>
Message-ID: <20200813153242.94742-2-uzonyi.akos@gmail.com>

---
 trie.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/trie.c b/trie.c
index b7d56ed5..b2d421cd 100644
--- a/trie.c
+++ b/trie.c
@@ -125,6 +125,12 @@ trie_data_block_calc_pos(struct trie *t, uint64_t key,
 	key_mask = (1 << t->data_block_key_bits) - 1;
 	*pos = (key & key_mask) >> (6 - t->item_size_lg);
 
+	if (t->item_size_lg == 6) {
+		*offs = 0;
+		*mask = -1;
+		return;
+	}
+
 	key_mask = (1 << (6 - t->item_size_lg)) - 1;
 	*offs = (key & key_mask) * (1 << t->item_size_lg);
 
-- 
2.28.0


From uzonyi.akos at gmail.com  Thu Aug 13 15:32:40 2020
From: uzonyi.akos at gmail.com (=?UTF-8?q?=C3=81kos=20Uzonyi?=)
Date: Thu, 13 Aug 2020 17:32:40 +0200
Subject: [RFC PATCH 2/4] Fix ns_id_size
In-Reply-To: <20200813153242.94742-1-uzonyi.akos@gmail.com>
References: <20200813153242.94742-1-uzonyi.akos@gmail.com>
Message-ID: <20200813153242.94742-3-uzonyi.akos@gmail.com>

---
 pidns.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/pidns.c b/pidns.c
index edab73f8..9d8695da 100644
--- a/pidns.c
+++ b/pidns.c
@@ -65,7 +65,7 @@ static const struct {
  */
 #define MAX_NS_DEPTH 32
 
-static const size_t ns_id_size = sizeof(unsigned int);
+static const size_t ns_id_size = sizeof(unsigned int) * 8;
 static const uint8_t ptr_sz_lg = (sizeof(void *) == 8 ? 6 : 5);
 
 static int pid_max;
-- 
2.28.0


From uzonyi.akos at gmail.com  Thu Aug 13 15:32:41 2020
From: uzonyi.akos at gmail.com (=?UTF-8?q?=C3=81kos=20Uzonyi?=)
Date: Thu, 13 Aug 2020 17:32:41 +0200
Subject: [RFC PATCH 3/4] Test pidns translation cache
In-Reply-To: <20200813153242.94742-1-uzonyi.akos@gmail.com>
References: <20200813153242.94742-1-uzonyi.akos@gmail.com>
Message-ID: <20200813153242.94742-4-uzonyi.akos@gmail.com>

---
 tests/.gitignore       |  1 +
 tests/Makefile.am      |  2 ++
 tests/pidns-cache.c    | 29 +++++++++++++++++++++++++++++
 tests/pidns-cache.test | 23 +++++++++++++++++++++++
 4 files changed, 55 insertions(+)
 create mode 100644 tests/pidns-cache.c
 create mode 100755 tests/pidns-cache.test

diff --git a/tests/.gitignore b/tests/.gitignore
index 4d1153fc..fc512ad2 100644
--- a/tests/.gitignore
+++ b/tests/.gitignore
@@ -525,6 +525,7 @@ pidfd_open-yy
 pidfd_open--pidns-translation
 pidfd_send_signal
 pidfd_send_signal--pidns-translation
+pidns-performance
 pipe
 pipe2
 pkey_alloc
diff --git a/tests/Makefile.am b/tests/Makefile.am
index f2c5da83..8aaa0cae 100644
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@@ -190,6 +190,7 @@ check_PROGRAMS = $(PURE_EXECUTABLES) \
 	perf_event_open_unabbrev \
 	pidfd_open--pidns-translation \
 	pidfd_send_signal--pidns-translation \
+	pidns-cache \
 	poll-P \
 	ppoll-P \
 	ppoll-v \
@@ -425,6 +426,7 @@ MISC_TESTS = \
 	opipe.test \
 	options-syntax.test \
 	pc.test \
+	pidns-cache.test \
 	printpath-umovestr-legacy.test \
 	printstrn-umoven-legacy.test \
 	qual_fault-syntax.test \
diff --git a/tests/pidns-cache.c b/tests/pidns-cache.c
new file mode 100644
index 00000000..989f7db3
--- /dev/null
+++ b/tests/pidns-cache.c
@@ -0,0 +1,29 @@
+/*
+ * Copyright (c) 2020 The strace developers.
+ * All rights reserved.
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+
+#include "tests.h"
+#include "pidns.h"
+
+#include <stdio.h>
+#include <unistd.h>
+
+/**
+ * There is a 1 sec timeout for this test. With pidns caching more than 1000
+ * syscalls can be executed, without caching only a few tens.
+ */
+#define SYSCALL_COUNT 200
+
+int
+main(void)
+{
+	pidns_test_init();
+
+        for (int i = 0; i < SYSCALL_COUNT; i++)
+                getpid();
+
+	return 0;
+}
diff --git a/tests/pidns-cache.test b/tests/pidns-cache.test
new file mode 100755
index 00000000..8c126f91
--- /dev/null
+++ b/tests/pidns-cache.test
@@ -0,0 +1,23 @@
+#!/bin/sh
+#
+# Test pidns translation cache.
+#
+# Copyright (c) 2020 The strace developers.
+# All rights reserved.
+#
+# SPDX-License-Identifier: GPL-2.0-or-later
+
+. "${srcdir=.}/init.sh"
+
+require_min_kernel_version_or_skip 4.9
+check_prog timeout
+
+run_prog > /dev/null
+timeout 1 $STRACE -o /dev/null --pidns-translation -f -e trace=getpid $args || {
+        rc=$?
+        if [ $rc -eq 124 ]; then
+                fail_ "pidns translation took too long"
+        else
+                fail_ "$args failed with code $rc"
+        fi
+}
-- 
2.28.0


From uzonyi.akos at gmail.com  Thu Aug 13 15:32:42 2020
From: uzonyi.akos at gmail.com (=?UTF-8?q?=C3=81kos=20Uzonyi?=)
Date: Thu, 13 Aug 2020 17:32:42 +0200
Subject: [RFC PATCH 4/4] Add test for trie
In-Reply-To: <20200813153242.94742-1-uzonyi.akos@gmail.com>
References: <20200813153242.94742-1-uzonyi.akos@gmail.com>
Message-ID: <20200813153242.94742-5-uzonyi.akos@gmail.com>

---
 tests/.gitignore  |  1 +
 tests/Makefile.am |  3 +++
 tests/trie.c      | 57 +++++++++++++++++++++++++++++++++++++++++++++++
 tests/trie.test   | 12 ++++++++++
 trie.c            |  4 +---
 5 files changed, 74 insertions(+), 3 deletions(-)
 create mode 100644 tests/trie.c
 create mode 100755 tests/trie.test

diff --git a/tests/.gitignore b/tests/.gitignore
index fc512ad2..34268a05 100644
--- a/tests/.gitignore
+++ b/tests/.gitignore
@@ -772,6 +772,7 @@ times
 times-fail
 tkill
 tracer_ppid_pgid_sid
+trie
 truncate
 truncate64
 ugetrlimit
diff --git a/tests/Makefile.am b/tests/Makefile.am
index 8aaa0cae..d1f1a98d 100644
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@@ -29,6 +29,7 @@ AM_CPPFLAGS = $(ARCH_MFLAGS) \
 AM_LDFLAGS = $(ARCH_MFLAGS)
 
 libtests_a_SOURCES = \
+	../trie.c ../trie.h \
 	create_nl_socket.c \
 	create_tmpfile.c \
 	errno2name.c \
@@ -246,6 +247,7 @@ check_PROGRAMS = $(PURE_EXECUTABLES) \
 	threads-execve-qq \
 	threads-execve-qqq \
 	tracer_ppid_pgid_sid \
+	trie \
 	unblock_reset_raise \
 	unix-pair-send-recv \
 	unix-pair-sendto-recvfrom \
@@ -467,6 +469,7 @@ MISC_TESTS = \
 	strace-tt.test \
 	strace-ttt.test \
 	termsig.test \
+	trie.test \
 	threads-execve.test \
 	umovestr_cached.test \
 	# end of MISC_TESTS
diff --git a/tests/trie.c b/tests/trie.c
new file mode 100644
index 00000000..26118c14
--- /dev/null
+++ b/tests/trie.c
@@ -0,0 +1,57 @@
+/*
+ * Copyright (c) 2017-2019 The strace developers.
+ * All rights reserved.
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+
+#include "tests.h"
+#include "trie.h"
+
+#include <stdio.h>
+
+static void
+assert_equals(const char *msg, uint64_t expected, uint64_t actual) {
+	if (actual != expected)
+		error_msg_and_fail("%s: expected: %ld, actual: %ld", msg, expected, actual);
+}
+
+int
+main(void)
+{
+	static const struct {
+		uint8_t key_size;
+		uint8_t item_size_lg;
+		uint8_t node_key_bits;
+		uint8_t data_block_key_bits;
+		uint64_t empty_value;
+
+		struct {
+			uint64_t key, value, expected_value;
+		} key_value_pairs[3];
+	} params[] = {
+		{64, 6, 10, 10, 0, {{2, 42, 42}, {0, 1, 1}, {2, 43, 43}}},
+	};
+
+	for (size_t i = 0; i < ARRAY_SIZE(params); i++) {
+		struct trie *t = trie_create(params[i].key_size,
+		                             params[i].item_size_lg,
+					     params[i].node_key_bits,
+					     params[i].data_block_key_bits,
+					     params[i].empty_value);
+
+		for (size_t j = 0; j < ARRAY_SIZE(params[i].key_value_pairs); j++) {
+			uint64_t key, value, expected;
+			key = params[i].key_value_pairs[j].key;
+			value = params[i].key_value_pairs[j].value;
+			expected = params[i].key_value_pairs[j].expected_value;
+
+			trie_set(t, key, value);
+			assert_equals("trie_get", expected, trie_get(t, key));
+		}
+
+		trie_free(t);
+	}
+
+	return 0;
+}
diff --git a/tests/trie.test b/tests/trie.test
new file mode 100755
index 00000000..f5a5bf68
--- /dev/null
+++ b/tests/trie.test
@@ -0,0 +1,12 @@
+#!/bin/sh
+#
+# Test trie.
+#
+# Copyright (c) 2020 The strace developers.
+# All rights reserved.
+#
+# SPDX-License-Identifier: LGPL-2.1-or-later
+
+. "${srcdir=.}/init.sh"
+
+run_prog
diff --git a/trie.c b/trie.c
index b2d421cd..e55c5027 100644
--- a/trie.c
+++ b/trie.c
@@ -7,8 +7,6 @@
  * SPDX-License-Identifier: LGPL-2.1-or-later
  */
 
-#include "defs.h"
-
 #include <stdbool.h>
 #include <stdint.h>
 #include <stdlib.h>
@@ -103,7 +101,7 @@ trie_get_node(struct trie *t, uint64_t key, bool auto_create)
 			if (!auto_create)
 				return NULL;
 
-			*cur_node = xcalloc(1 << sz, 1);
+			*cur_node = calloc(1 << sz, 1);
 		}
 
 		if (cur_depth >= t->max_depth)
-- 
2.28.0