[PATCHv4] print stack trace after each syscall

[Luca Clementi]

On Tue, Sep 17, 2013 at 5:12 AM, Masatake YAMATO <yamato at redhat.com> wrote:
>> In the patch `delete_mmap_cache' is used as a trigger for updating
>> proc/maps info cache.  It is called as expected when mmap and friends
>> are traced.  However, if the tracing is disabled with -e option, strae
>> misses the chance to updating the info cache.
>
> Could you review this patch for the bug I reported and merge if appreciated.
>
> `REQUIRED_BY_STACKTRACE' is introduced to trigger the `delete_mmap_cache'.
>

It works for me.

Acked-by: Luca Clementi <luca.clementi at gmail.com>

Thanks for the fix,
Luca


> Masatake YAMATO
>
>
>
> diff --git a/defs.h b/defs.h
> index 7f76008..46188c9 100644
> --- a/defs.h
> +++ b/defs.h
> @@ -557,6 +557,7 @@ extern const struct xlat whence_codes[];
>  #define TRACE_DESC     040     /* Trace file descriptor-related syscalls. */
>  #define TRACE_MEMORY   0100    /* Trace memory mapping-related syscalls. */
>  #define SYSCALL_NEVER_FAILS    0200    /* Syscall is always successful. */
> +#define REQUIRED_BY_STACKTRACE  0400   /* Trigger proc/maps cache updating */
>
>  typedef enum {
>         CFLAG_NONE = 0,
> diff --git a/linux/x86_64/syscallent.h b/linux/x86_64/syscallent.h
> index 8e3a200..a710401 100644
> --- a/linux/x86_64/syscallent.h
> +++ b/linux/x86_64/syscallent.h
> @@ -7,9 +7,9 @@
>         { 2,    TF,     sys_lstat,              "lstat"         },  /* 6 */
>         { 3,    TD,     sys_poll,               "poll"          },  /* 7 */
>         { 3,    TD,     sys_lseek,              "lseek"         },  /* 8 */
> -       { 6,    TD|TM,  sys_mmap,               "mmap"          },  /* 9 */
> -       { 3,    TM,     sys_mprotect,           "mprotect"      },  /* 10 */
> -       { 2,    TM,     sys_munmap,             "munmap"        },  /* 11 */
> +       { 6,    TD|TM|RT,sys_mmap,              "mmap"          },  /* 9 */
> +       { 3,    TM|RT,  sys_mprotect,           "mprotect"      },  /* 10 */
> +       { 2,    TM|RT,  sys_munmap,             "munmap"        },  /* 11 */
>         { 1,    TM,     sys_brk,                "brk"           },  /* 12 */
>         { 4,    TS,     sys_rt_sigaction,       "rt_sigaction"  },  /* 13 */
>         { 4,    TS,     sys_rt_sigprocmask,     "rt_sigprocmask"},  /* 14 */
> @@ -23,7 +23,7 @@
>         { 1,    TD,     sys_pipe,               "pipe"          },  /* 22 */
>         { 5,    TD,     sys_select,             "select"        },  /* 23 */
>         { 0,    0,      sys_sched_yield,        "sched_yield"   },  /* 24 */
> -       { 5,    TM,     sys_mremap,             "mremap"        },  /* 25 */
> +       { 5,    TM|RT,  sys_mremap,             "mremap"        },  /* 25 */
>         { 3,    TM,     sys_msync,              "msync"         },  /* 26 */
>         { 3,    TM,     sys_mincore,            "mincore"       },  /* 27 */
>         { 3,    TM,     sys_madvise,            "madvise"       },  /* 28 */
> @@ -57,7 +57,7 @@
>         { 5,    TP,     sys_clone,              "clone"         },  /* 56 */
>         { 0,    TP,     sys_fork,               "fork"          },  /* 57 */
>         { 0,    TP,     sys_vfork,              "vfork"         },  /* 58 */
> -       { 3,    TF|TP,  sys_execve,             "execve"        },  /* 59 */
> +       { 3,    TF|TP|RT,sys_execve,            "execve"        },  /* 59 */
>         { 1,    TP,     sys_exit,               "_exit"         },  /* 60 */
>         { 4,    TP,     sys_wait4,              "wait4"         },  /* 61 */
>         { 2,    TS,     sys_kill,               "kill"          },  /* 62 */
> diff --git a/mem.c b/mem.c
> index ca6caa1..ef273c7 100644
> --- a/mem.c
> +++ b/mem.c
> @@ -175,11 +175,6 @@ static int
>  print_mmap(struct tcb *tcp, long *u_arg, unsigned long long offset)
>  {
>         if (entering(tcp)) {
> -#ifdef USE_LIBUNWIND
> -               if (stack_trace_enabled)
> -                       delete_mmap_cache(tcp);
> -#endif
> -
>                 /* addr */
>                 if (!u_arg[0])
>                         tprints("NULL, ");
> @@ -309,12 +304,6 @@ sys_munmap(struct tcb *tcp)
>                 tprintf("%#lx, %lu",
>                         tcp->u_arg[0], tcp->u_arg[1]);
>         }
> -#ifdef USE_LIBUNWIND
> -       else {
> -               if (stack_trace_enabled)
> -                       delete_mmap_cache(tcp);
> -       }
> -#endif
>         return 0;
>  }
>
> @@ -326,12 +315,6 @@ sys_mprotect(struct tcb *tcp)
>                         tcp->u_arg[0], tcp->u_arg[1]);
>                 printflags(mmap_prot, tcp->u_arg[2], "PROT_???");
>         }
> -#ifdef USE_LIBUNWIND
> -       else {
> -               if (stack_trace_enabled)
> -                       delete_mmap_cache(tcp);
> -       }
> -#endif
>         return 0;
>  }
>
> diff --git a/process.c b/process.c
> index 22bb5b6..aaea9c5 100644
> --- a/process.c
> +++ b/process.c
> @@ -992,12 +992,6 @@ sys_execve(struct tcb *tcp)
>                         tprints("]");
>                 }
>         }
> -#ifdef USE_LIBUNWIND
> -       else {
> -               if (stack_trace_enabled)
> -                       delete_mmap_cache(tcp);
> -       }
> -#endif
>
>         return 0;
>  }
> diff --git a/syscall.c b/syscall.c
> index b01c023..7ddde88 100644
> --- a/syscall.c
> +++ b/syscall.c
> @@ -97,6 +97,7 @@
>  #define TM TRACE_MEMORY
>  #define NF SYSCALL_NEVER_FAILS
>  #define MA MAX_ARGS
> +#define RT REQUIRED_BY_STACKTRACE
>
>  const struct_sysent sysent0[] = {
>  #include "syscallent.h"
> @@ -2712,6 +2713,11 @@ trace_syscall_exiting(struct tcb *tcp)
>  #endif
>
>   ret:
> +#ifdef USE_LIBUNWIND
> +       if (stack_trace_enabled)
> +         if (tcp->s_ent->sys_flags & REQUIRED_BY_STACKTRACE)
> +           delete_mmap_cache(tcp);
> +#endif
>         tcp->flags &= ~TCB_INSYSCALL;
>         return 0;
>  }