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| author | Ian Rogers <irogers@google.com> | 2019-09-25 12:59:24 -0700 |
|---|---|---|
| committer | Arnaldo Carvalho de Melo <acme@redhat.com> | 2019-09-27 09:26:14 -0300 |
| commit | e3e2cf3d5b1fe800b032e14c0fdcd9a6fb20cf3b (patch) | |
| tree | 34e170583b1cc56f51ac08120b5f6adeb6d43b8d /tools | |
| parent | 4b0b2b096da9d296e0e5668cdfba8613bd6f5bc8 (diff) | |
| download | linux-stable-e3e2cf3d5b1fe800b032e14c0fdcd9a6fb20cf3b.tar.gz linux-stable-e3e2cf3d5b1fe800b032e14c0fdcd9a6fb20cf3b.tar.bz2 linux-stable-e3e2cf3d5b1fe800b032e14c0fdcd9a6fb20cf3b.zip | |
perf tests: Avoid raising SEGV using an obvious NULL dereference
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
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 ~]#
Fixes: a074865e60ed ("perf tools: Introduce perf hooks")
Signed-off-by: Ian Rogers <irogers@google.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lore.kernel.org/lkml/20190925195924.152834-2-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Diffstat (limited to 'tools')
| -rw-r--r-- | tools/perf/tests/perf-hooks.c | 3 |
1 files changed, 1 insertions, 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) |