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| author | Peter Zijlstra <peterz@infradead.org> | 2018-09-25 17:58:35 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2018-10-02 09:37:56 +0200 |
| commit | a9f9772114c8b07ae75bcb3654bd017461248095 (patch) | |
| tree | af2008edb00495276c182e7d77f8c334ab502ef1 /kernel | |
| parent | 291d0e5d81e101392379217b06251fe8c27f1f80 (diff) | |
| download | linux-0-day-a9f9772114c8b07ae75bcb3654bd017461248095.tar.gz linux-0-day-a9f9772114c8b07ae75bcb3654bd017461248095.tar.xz | |
perf/core: Fix perf_pmu_unregister() locking
When we unregister a PMU, we fail to serialize the @pmu_idr properly.
Fix that by doing the entire thing under pmu_lock.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.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: Vince Weaver <vincent.weaver@maine.edu>
Fixes: 2e80a82a49c4 ("perf: Dynamic pmu types")
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/events/core.c | 9 |
1 files changed, 2 insertions, 7 deletions
diff --git a/kernel/events/core.c b/kernel/events/core.c index dcb093e7b3777..dfb1d951789ea 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -9431,9 +9431,7 @@ static void free_pmu_context(struct pmu *pmu) if (pmu->task_ctx_nr > perf_invalid_context) return; - mutex_lock(&pmus_lock); free_percpu(pmu->pmu_cpu_context); - mutex_unlock(&pmus_lock); } /* @@ -9689,12 +9687,8 @@ EXPORT_SYMBOL_GPL(perf_pmu_register); void perf_pmu_unregister(struct pmu *pmu) { - int remove_device; - mutex_lock(&pmus_lock); - remove_device = pmu_bus_running; list_del_rcu(&pmu->entry); - mutex_unlock(&pmus_lock); /* * We dereference the pmu list under both SRCU and regular RCU, so @@ -9706,13 +9700,14 @@ void perf_pmu_unregister(struct pmu *pmu) free_percpu(pmu->pmu_disable_count); if (pmu->type >= PERF_TYPE_MAX) idr_remove(&pmu_idr, pmu->type); - if (remove_device) { + if (pmu_bus_running) { if (pmu->nr_addr_filters) device_remove_file(pmu->dev, &dev_attr_nr_addr_filters); device_del(pmu->dev); put_device(pmu->dev); } free_pmu_context(pmu); + mutex_unlock(&pmus_lock); } EXPORT_SYMBOL_GPL(perf_pmu_unregister); |