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| author | Yan, Zheng <zheng.z.yan@intel.com> | 2012-06-15 14:31:31 +0800 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2012-06-18 12:13:20 +0200 |
| commit | fbfc623f8231c8d8c78aab5841e9c6e5811ab638 (patch) | |
| tree | 54883756f1b404f2232d4d5077219ea98c1fdbfd | |
| parent | 4b4969b14490a4f65b572b8f180164181104b5e1 (diff) | |
| download | linux-stable-fbfc623f8231c8d8c78aab5841e9c6e5811ab638.tar.gz linux-stable-fbfc623f8231c8d8c78aab5841e9c6e5811ab638.tar.bz2 linux-stable-fbfc623f8231c8d8c78aab5841e9c6e5811ab638.zip | |
perf: Avoid race between cpu hotplug and installing event
perf_event_open() requires the cpu on which to install event is online,
but the cpu can go offline after perf_event_open checks that. Add a
get_online_cpus()/put_online_cpus() pair to avoid the race.
Signed-off-by: Zheng Yan <zheng.z.yan@intel.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1339741902-8449-3-git-send-email-zheng.z.yan@intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
| -rw-r--r-- | kernel/events/core.c | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/kernel/events/core.c b/kernel/events/core.c index d7d71d6ec972..31d182e01549 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -6252,6 +6252,8 @@ SYSCALL_DEFINE5(perf_event_open, } } + get_online_cpus(); + event = perf_event_alloc(&attr, cpu, task, group_leader, NULL, NULL, NULL); if (IS_ERR(event)) { @@ -6391,6 +6393,8 @@ SYSCALL_DEFINE5(perf_event_open, perf_unpin_context(ctx); mutex_unlock(&ctx->mutex); + put_online_cpus(); + event->owner = current; mutex_lock(¤t->perf_event_mutex); @@ -6419,6 +6423,7 @@ err_context: err_alloc: free_event(event); err_task: + put_online_cpus(); if (task) put_task_struct(task); err_group_fd: |