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 12:04:18 +0100 |
| commit | 62f57041fbdf15db6336542384a4b36f1f387299 (patch) | |
| tree | f85cc3e5f0e7463dd8a9dcf828f74068fcc56aa9 /arch | |
| parent | 8e0ec20539f8c626463ae43fcaeb218e3b2b5dc4 (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>
Cc: stable@vger.kernel.org
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>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/x86/kernel/cpu/perf_event.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/arch/x86/kernel/cpu/perf_event.c b/arch/x86/kernel/cpu/perf_event.c index 1a8256dd6729..5b2f2306fbcc 100644 --- a/arch/x86/kernel/cpu/perf_event.c +++ b/arch/x86/kernel/cpu/perf_event.c @@ -1996,8 +1996,8 @@ 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) |