Re: ftrace/perf_event leak

[Peter Zijlstra <peterz@infradead.org>]

On Wed, 2010-09-01 at 13:38 +0300, Avi Kivity wrote:
> On 09/01/2010 12:38 PM, Li Zefan wrote:
> >
> > Then try this:
> 
> Tested-by: Avi Kivity <avi@redhat.com>
> 

Thanks, queued as:

---
Subject: perf, trace: Fix module leak
From: Li Zefan <lizf@cn.fujitsu.com>
Date: Wed Sep 01 12:58:43 CEST 2010

Commit 1c024eca (perf, trace: Optimize tracepoints by using
per-tracepoint-per-cpu hlist to track events) caused a module refcount
leak.

Tested-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <4C7E1F12.8030304@cn.fujitsu.com>
---
 kernel/trace/trace_event_perf.c |    3 +++
 1 file changed, 3 insertions(+)

Index: linux-2.6/kernel/trace/trace_event_perf.c
===================================================================
--- linux-2.6.orig/kernel/trace/trace_event_perf.c
+++ linux-2.6/kernel/trace/trace_event_perf.c
@@ -91,6 +91,8 @@ int perf_trace_init(struct perf_event *p
 		    tp_event->class && tp_event->class->reg &&
 		    try_module_get(tp_event->mod)) {
 			ret = perf_trace_event_init(tp_event, p_event);
+			if (ret)
+				module_put(tp_event->mod);
 			break;
 		}
 	}
@@ -147,6 +149,7 @@ void perf_trace_destroy(struct perf_even
 		}
 	}
 out:
+	module_put(tp_event->mod);
 	mutex_unlock(&event_mutex);
 }