From f16009527595ee562308653bc3d0039166d2ab15 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Thu, 19 Mar 2009 20:26:16 +0100 Subject: [PATCH] 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: Peter Zijlstra Cc: Paul Mackerras Cc: Steven Rostedt Orig-LKML-Reference: <20090319194233.652078652@chello.nl> Signed-off-by: Ingo Molnar --- kernel/perf_counter.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) diff --git a/kernel/perf_counter.c b/kernel/perf_counter.c index 99d5930..97f891f 100644 --- a/kernel/perf_counter.c +++ b/kernel/perf_counter.c @@ -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); } } -- 2.7.4