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perf_counter: fix up counter free paths

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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: Peter 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: Ingo Molnar <mingo@elte.hu>
This commit is contained in:
Peter Zijlstra 2009-03-19 20:26:16 +01:00 committed by Ingo Molnar
parent 4a0deca657
commit f160095275
1 changed files with 8 additions and 3 deletions
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11
kernel/perf_counter.c
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@ -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);
}
}