mbox series

[v2,0/8] Update to C11, fix signal undefined behavior

Message ID 20221024181913.630986-1-irogers@google.com
Headers
Series Update to C11, fix signal undefined behavior |

Message

Ian Rogers Oct. 24, 2022, 6:19 p.m. UTC 
  The use of C11 is mainstream in the kernel [1]. There was some
confusion on volatile and signal handlers in [2] for which atomics
(present in C11) make things clearer. Switch to using volatile
sig_atomic_t as per [3]. Thanks to Leo Yan <leo.yan@linaro.org> for
the suggestions.

[1] https://lore.kernel.org/lkml/CAHk-=whWbENRz-vLY6vpESDLj6kGUTKO3khGtVfipHqwewh2HQ@mail.gmail.com/
[2] https://lore.kernel.org/lkml/20221024011024.462518-1-irogers@google.com/
[3] https://wiki.sei.cmu.edu/confluence/display/c/SIG31-C.+Do+not+access+shared+objects+in+signal+handlers

v2. Remove unneeded stdatomic.h includes for sig_atomic_t as it is
    declared in signal.h.

Ian Rogers (8):
  perf build: Update to C standard to gnu11
  perf record: Use sig_atomic_t for signal handlers
  perf daemon: Use sig_atomic_t to avoid UB
  perf ftrace: Use sig_atomic_t to avoid UB
  perf session: Change type to avoid UB
  perf stat: Use sig_atomic_t to avoid UB
  perf top: Use sig_atomic_t to avoid UB
  perf trace: Use sig_atomic_t to avoid UB

 tools/perf/Makefile.config  | 2 +-
 tools/perf/builtin-daemon.c | 2 +-
 tools/perf/builtin-ftrace.c | 4 ++--
 tools/perf/builtin-record.c | 8 ++++----
 tools/perf/builtin-stat.c   | 8 ++++----
 tools/perf/builtin-top.c    | 4 ++--
 tools/perf/builtin-trace.c  | 4 ++--
 tools/perf/util/session.c   | 3 ++-
 8 files changed, 18 insertions(+), 17 deletions(-)

Comments

Arnaldo Carvalho de Melo Nov. 3, 2022, 1:04 p.m. UTC | #1 
Em Mon, Oct 24, 2022 at 11:19:05AM -0700, Ian Rogers escreveu:
> The use of C11 is mainstream in the kernel [1]. There was some
> confusion on volatile and signal handlers in [2] for which atomics
> (present in C11) make things clearer. Switch to using volatile
> sig_atomic_t as per [3]. Thanks to Leo Yan <leo.yan@linaro.org> for
> the suggestions.

Thanks, applied and testing building it now.

- Arnaldo
 
> [1] https://lore.kernel.org/lkml/CAHk-=whWbENRz-vLY6vpESDLj6kGUTKO3khGtVfipHqwewh2HQ@mail.gmail.com/
> [2] https://lore.kernel.org/lkml/20221024011024.462518-1-irogers@google.com/
> [3] https://wiki.sei.cmu.edu/confluence/display/c/SIG31-C.+Do+not+access+shared+objects+in+signal+handlers
> 
> v2. Remove unneeded stdatomic.h includes for sig_atomic_t as it is
>     declared in signal.h.
> 
> Ian Rogers (8):
>   perf build: Update to C standard to gnu11
>   perf record: Use sig_atomic_t for signal handlers
>   perf daemon: Use sig_atomic_t to avoid UB
>   perf ftrace: Use sig_atomic_t to avoid UB
>   perf session: Change type to avoid UB
>   perf stat: Use sig_atomic_t to avoid UB
>   perf top: Use sig_atomic_t to avoid UB
>   perf trace: Use sig_atomic_t to avoid UB
> 
>  tools/perf/Makefile.config  | 2 +-
>  tools/perf/builtin-daemon.c | 2 +-
>  tools/perf/builtin-ftrace.c | 4 ++--
>  tools/perf/builtin-record.c | 8 ++++----
>  tools/perf/builtin-stat.c   | 8 ++++----
>  tools/perf/builtin-top.c    | 4 ++--
>  tools/perf/builtin-trace.c  | 4 ++--
>  tools/perf/util/session.c   | 3 ++-
>  8 files changed, 18 insertions(+), 17 deletions(-)
> 
> -- 
> 2.38.0.135.g90850a2211-goog