Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull perf fix from Ingo Molnar:
 "This fix adds missing RCU read protection"

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  events: Protect access via task_subsys_state_check()

1 files changed, 2 insertions, 0 deletions

diff --git a/kernel/events/core.c b/kernel/events/core.c
index 4d3124b39277..9fcb0944f071 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -4596,6 +4596,7 @@ void perf_event_comm(struct task_struct *task)
         struct perf_event_context *ctx;
         int ctxn;
 
+        rcu_read_lock();
         for_each_task_context_nr(ctxn) {
                 ctx = task->perf_event_ctxp[ctxn];
                 if (!ctx)
@@ -4603,6 +4604,7 @@ void perf_event_comm(struct task_struct *task)
 
                 perf_event_enable_on_exec(ctx);
         }
+        rcu_read_unlock();
 
         if (!atomic_read(&nr_comm_events))
                 return;