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authorPeter Zijlstra <peterz@infradead.org>2018-09-25 17:58:35 +0200
committerIngo Molnar <mingo@kernel.org>2018-10-02 09:37:56 +0200
commita9f9772114c8b07ae75bcb3654bd017461248095 (patch)
treeaf2008edb00495276c182e7d77f8c334ab502ef1 /kernel
parent291d0e5d81e101392379217b06251fe8c27f1f80 (diff)
downloadlinux-a9f9772114c8b07ae75bcb3654bd017461248095.tar.bz2
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.c9
1 files changed, 2 insertions, 7 deletions
diff --git a/kernel/events/core.c b/kernel/events/core.c
index dcb093e7b377..dfb1d951789e 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);