Em Wed, Sep 25, 2019 at 12:59:24PM -0700, Ian Rogers escreveu: > An optimized build such as: > make -C tools/perf CLANG=1 CC=clang EXTRA_CFLAGS="-O3 > will turn the dereference operation into a ud2 instruction, raising a SIGILL > rather than a SIGSEGV. Use raise(..) for correctness and clarity. > > Similar issues were addressed in Numfor Mbiziwo-Tiapo's patch: > https://lkml.org/lkml/2019/7/8/1234
Added: Cc: Numfor Mbiziwo-Tiapo <[email protected]> And: Cc: Wang Nan <[email protected]> Fixes: a074865e60ed ("perf tools: Introduce perf hooks") And: Committer testing: Before: [root@quaco ~]# perf test hooks 55: perf hooks : Ok [root@quaco ~]# perf test -v hooks 55: perf hooks : --- start --- test child forked, pid 17092 SIGSEGV is observed as expected, try to recover. Fatal error (SEGFAULT) in perf hook 'test' test child finished with 0 ---- end ---- perf hooks: Ok [root@quaco ~]# After: [root@quaco ~]# perf test hooks 55: perf hooks : Ok [root@quaco ~]# perf test -v hooks 55: perf hooks : --- start --- test child forked, pid 17909 SIGSEGV is observed as expected, try to recover. Fatal error (SEGFAULT) in perf hook 'test' test child finished with 0 ---- end ---- perf hooks: Ok [root@quaco ~]# ---------------------------------------------------------------------------- Thanks, applied. - Arnaldo > Signed-off-by: Ian Rogers <[email protected]> > --- > tools/perf/tests/perf-hooks.c | 3 +-- > 1 file changed, 1 insertion(+), 2 deletions(-) > > diff --git a/tools/perf/tests/perf-hooks.c b/tools/perf/tests/perf-hooks.c > index dbc27199c65e..dd865e0bea12 100644 > --- a/tools/perf/tests/perf-hooks.c > +++ b/tools/perf/tests/perf-hooks.c > @@ -19,12 +19,11 @@ static void sigsegv_handler(int sig __maybe_unused) > static void the_hook(void *_hook_flags) > { > int *hook_flags = _hook_flags; > - int *p = NULL; > > *hook_flags = 1234; > > /* Generate a segfault, test perf_hooks__recover */ > - *p = 0; > + raise(SIGSEGV); > } > > int test__perf_hooks(struct test *test __maybe_unused, int subtest > __maybe_unused) > -- > 2.23.0.351.gc4317032e6-goog -- - Arnaldo
