]> git.proxmox.com Git - mirror_ubuntu-kernels.git/commit
perf trace: Avoid early exit due SIGCHLD from non-workload processes
authorChangbin Du <changbin.du@gmail.com>
Tue, 8 Feb 2022 14:07:25 +0000 (22:07 +0800)
committerArnaldo Carvalho de Melo <acme@redhat.com>
Wed, 16 Feb 2022 16:47:12 +0000 (13:47 -0300)
commitde9f498d2b381de1abf654ca3459c4f01227b5cd
tree0f89ebdaa634c5f096259baebc8a4d1156a6c246
parent0bc2ba49101f4ca35e0c878968adb5660ffa2517
perf trace: Avoid early exit due SIGCHLD from non-workload processes

The function trace__symbols_init() runs "perf-read-vdso32" and that ends up
with a SIGCHLD delivered to 'perf'. And this SIGCHLD make perf exit early.

'perf trace' should exit only if the SIGCHLD is from our workload process.
So let's use sigaction() instead of signal() to match such condition.

Committer notes:

Use memset to zero the 'struct sigaction' variable as the '= { 0 }'
method isn't accepted in many compiler versions, e.g.:

   4    34.02 alpine:3.6                    : FAIL clang version 4.0.0 (tags/RELEASE_400/final)
    builtin-trace.c:4897:35: error: suggest braces around initialization of subobject [-Werror,-Wmissing-braces]
            struct sigaction sigchld_act = { 0 };
                                             ^
                                             {}
    builtin-trace.c:4897:37: error: missing field 'sa_mask' initializer [-Werror,-Wmissing-field-initializers]
            struct sigaction sigchld_act = { 0 };
                                               ^
    2 errors generated.
   6    32.60 alpine:3.8                    : FAIL gcc version 6.4.0 (Alpine 6.4.0)
    builtin-trace.c:4897:35: error: suggest braces around initialization of subobject [-Werror,-Wmissing-braces]
            struct sigaction sigchld_act = { 0 };
                                             ^
                                             {}
    builtin-trace.c:4897:37: error: missing field 'sa_mask' initializer [-Werror,-Wmissing-field-initializers]
            struct sigaction sigchld_act = { 0 };
                                               ^
    2 errors generated.
   7    34.82 alpine:3.9                    : FAIL gcc version 8.3.0 (Alpine 8.3.0)
    builtin-trace.c:4897:35: error: suggest braces around initialization of subobject [-Werror,-Wmissing-braces]
            struct sigaction sigchld_act = { 0 };
                                             ^
                                             {}
    builtin-trace.c:4897:37: error: missing field 'sa_mask' initializer [-Werror,-Wmissing-field-initializers]
            struct sigaction sigchld_act = { 0 };
                                               ^
    2 errors generated.

Signed-off-by: Changbin Du <changbin.du@gmail.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20220208140725.3947-1-changbin.du@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
tools/perf/builtin-trace.c