diff options
| author | Chris Wilson <chris@chris-wilson.co.uk> | 2017-05-12 12:45:25 +0100 |
|---|---|---|
| committer | Daniel Vetter <daniel.vetter@ffwll.ch> | 2021-11-16 09:24:36 +0100 |
| commit | 5179ec408bcdb7d305f4f7665a95bf108141eeab (patch) | |
| tree | 1fccaf2d7d7d8d18d5043306ca3dc24a0e1a169a /kernel/events/core.c | |
| parent | 2c2dfe8da9505a178fd1839d4f7dd749de626539 (diff) | |
perf/core: Avoid removing shared pmu_context on unregister
In commit 1fd7e4169954 ("perf/core: Remove perf_cpu_context::unique_pmu"),
the search for another user of the pmu_cpu_context was removed, and so
we unconditionally free it during perf_pmu_unregister. This leads to
random corruption later and a BUG at mm/percpu.c:689.
v2: Check for shared pmu_contexts under the mutex.
Fixes: 1fd7e4169954 ("perf/core: Remove perf_cpu_context::unique_pmu")
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: David Carrillo-Cisneros <davidcc@google.com>
Cc: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: <stable@vger.kernel.org> # v4.11+
Link: http://patchwork.freedesktop.org/patch/msgid/20170512114525.17575-1-chris@chris-wilson.co.uk
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Diffstat (limited to 'kernel/events/core.c')
| -rw-r--r-- | kernel/events/core.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/kernel/events/core.c b/kernel/events/core.c index 523106a506ee..4829e9b397d5 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -11210,7 +11210,8 @@ void perf_pmu_unregister(struct pmu *pmu) device_del(pmu->dev); put_device(pmu->dev); } - free_pmu_context(pmu); + if (!find_pmu_context(pmu->task_ctx_nr)) + free_pmu_context(pmu); mutex_unlock(&pmus_lock); } EXPORT_SYMBOL_GPL(perf_pmu_unregister); |