Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit f1600952 authored by Peter Zijlstra's avatar Peter Zijlstra Committed by Ingo Molnar
Browse files

perf_counter: fix up counter free paths 



Impact: fix crash during perfcounters use

I found another counter free path, create a free_counter() call to
accomodate generic tear-down.

Fixes an RCU bug.

Signed-off-by: default avatarPeter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Orig-LKML-Reference: <20090319194233.652078652@chello.nl>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent 4a0deca6

kernel/perf_counter.c

+8 −3
Original line number Diff line number Diff line
@@ -1150,6 +1150,11 @@ static void free_counter_rcu(struct rcu_head *head) 
	kfree(counter);

}



static void free_counter(struct perf_counter *counter)

{

	call_rcu(&counter->rcu_head, free_counter_rcu);

}



/*

 * Called when the last reference to the file is gone.

 */
@@ -1168,7 +1173,7 @@ static int perf_release(struct inode *inode, struct file *file) 
	mutex_unlock(&counter->mutex);

	mutex_unlock(&ctx->mutex);



	call_rcu(&counter->rcu_head, free_counter_rcu);

	free_counter(counter);

	put_context(ctx);



	return 0;
@@ -2128,10 +2133,10 @@ __perf_counter_exit_task(struct task_struct *child, 
					 list_entry) {

			if (sub->parent) {

				sync_child_counter(sub, sub->parent);

				kfree(sub);

				free_counter(sub);

			}

		}

		kfree(child_counter);

		free_counter(child_counter);

	}

}