diff options
| author | Andy Lutomirski <luto@kernel.org> | 2017-03-16 12:59:39 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2017-03-22 12:43:40 +0100 |
| commit | 9f9115b67aa5821e1d5490d94c1ad87d0396f7b6 (patch) | |
| tree | df32019969ce77fc97dff5edff98205a09e4cade | |
| parent | 24ba2842a49da3338581b42a5618088d2a0b0730 (diff) | |
x86/perf: Fix CR4.PCE propagation to use active_mm instead of mm
commit 5dc855d44c2ad960a86f593c60461f1ae1566b6d upstream.
If one thread mmaps a perf event while another thread in the same mm
is in some context where active_mm != mm (which can happen in the
scheduler, for example), refresh_pce() would write the wrong value
to CR4.PCE. This broke some PAPI tests.
Reported-and-tested-by: Vince Weaver <vincent.weaver@maine.edu>
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Borislav Petkov <bpetkov@suse.de>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Fixes: 7911d3f7af14 ("perf/x86: Only allow rdpmc if a perf_event is mapped")
Link: http://lkml.kernel.org/r/0c5b38a76ea50e405f9abe07a13dfaef87c173a1.1489694270.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | arch/x86/events/core.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/arch/x86/events/core.c b/arch/x86/events/core.c index 7fe88bb57e36..38623e219816 100644 --- a/arch/x86/events/core.c +++ b/arch/x86/events/core.c @@ -2096,8 +2096,8 @@ static int x86_pmu_event_init(struct perf_event *event) static void refresh_pce(void *ignored) { - if (current->mm) - load_mm_cr4(current->mm); + if (current->active_mm) + load_mm_cr4(current->active_mm); } static void x86_pmu_event_mapped(struct perf_event *event) |