[PATCH v10 0/5] [PIDNS] Final

[Ákos Uzonyi]

On Thu, 20 Aug 2020 at 11:34, Dmitry V. Levin <ldv at altlinux.org> wrote:
> Hi,
>
> When I tried this patchset on various systems, on those where NS_* ioctl
> commands are not supported by the kernel, a lot of tests start failing with
> similar diagnostics.  For example:
>
> FAIL: dup-y.gen
> ===============
>
> + ../strace -V
> + TIMEOUT='timeout -k 5 -s XCPU 2100'
> + timeout -k 5 -s XCPU 2100 true
> + '[' 1 -eq 0 ']'
> + exec timeout -k 5 -s XCPU 2100 ./dup-y.gen.test
> + run_strace_match_diff -a8 --trace=dup -y
> + args='-a8 --trace=dup -y'
> + '[' -n '-a8 --trace=dup -y' -a '(' -z '-a8 --trace=dup -y' -o -z '' ')' ']'
> + run_prog
> + '[' 0 -eq 0 ']'
> + set -- ../dup-y
> + args=../dup-y
> + ../dup-y
> + run_strace -a8 --trace=dup -y ../dup-y
> + args='-a8 --trace=dup -y ../dup-y'
> + ../../strace -o log -a8 --trace=dup -y ../dup-y
> ../../strace: NS_* ioctl commands are not supported by the kernel
> + match_diff log exp
> + local output expected error
> + '[' 2 -eq 0 ']'
> + output=log
> + shift
> + '[' 1 -eq 0 ']'
> + expected=exp
> + shift
> + '[' 0 -eq 0 ']'
> + error='../../strace -a8 --trace=dup -y ../dup-y output mismatch'
> + check_prog diff
> + type diff
> + diff -u -- exp log
> --- exp 2020-08-20 00:53:31.868741256 +0000
> +++ log 2020-08-20 00:53:31.868741256 +0000
> @@ -1,5 +1,5 @@
>  dup(-1) = -1 EBADF (Bad file descriptor)
> -dup(0</dev/null>) = 3</dev/null>
> -dup(3</dev/null>) = 4</dev/null>
> -dup(9</dev/full>) = 5</dev/full>
> +dup(0)  = 3
> +dup(3)  = 4
> +dup(9)  = 5
>  +++ exited with 0 +++
> + fail_ '../../strace -a8 --trace=dup -y ../dup-y output mismatch'
> + warn_ 'dup-y.gen.test: failed test: ../../strace -a8 --trace=dup -y ../dup-y output mismatch'
> + printf '%s\n' 'dup-y.gen.test: failed test: ../../strace -a8 --trace=dup -y ../dup-y output mismatch'
> dup-y.gen.test: failed test: ../../strace -a8 --trace=dup -y ../dup-y output mismatch
> + exit 1
> FAIL dup-y.gen.test (exit status: 1)

Interesting. On travis we have some systems where NS_* ioctl commands
are not supported, and all tests pass. I think the problem is caused
by is_proc_ours returning false (otherwise translation should be
trivial, and no NS_ ioctl commands would be needed). First I thought
that /proc is not mounted on that system, but dup-y is skipped if
/proc/self/fd is not available (anyway we should check if /proc is
mounted and return 0 in translate_pid if not). Also I think we could
print error messages if /proc/%s/ns/pid or /proc/%s/status is not
available. Is it possible that these are not available on this system?