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authorFrederic Weisbecker <fweisbec@gmail.com>2009-10-03 14:55:18 +0200
committerFrederic Weisbecker <fweisbec@gmail.com>2009-10-05 10:57:41 +0200
commitfe8e5b5a60f8427940d33b205e127aecfb0bca10 (patch)
treed4d18d4a69175f715c9483e0e92ae73f8deda090 /kernel/trace
parent8a0382f6fceaf0c6479e582e1054f36333ea3d24 (diff)
tracing: Check total refcount before releasing bufs in profile_enable failure
When we call the profile_enable() callback of an event, we release the shared perf event tracing buffers unconditionnaly in the failure path. This is wrong because there may be other users of these. Then check the total refcount before doing this. Reported-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Ingo Molnar <mingo@elte.hu> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Li Zefan <lizf@cn.fujitsu.com>
Diffstat (limited to 'kernel/trace')
-rw-r--r--kernel/trace/trace_event_profile.c15
1 files changed, 10 insertions, 5 deletions
diff --git a/kernel/trace/trace_event_profile.c b/kernel/trace/trace_event_profile.c
index dd44b876886..e52784b7b84 100644
--- a/kernel/trace/trace_event_profile.c
+++ b/kernel/trace/trace_event_profile.c
@@ -31,7 +31,7 @@ static int ftrace_profile_enable_event(struct ftrace_event_call *event)
if (atomic_inc_return(&event->profile_count))
return 0;
- if (!total_profile_count++) {
+ if (!total_profile_count) {
buf = (char *)alloc_percpu(profile_buf_t);
if (!buf)
goto fail_buf;
@@ -46,14 +46,19 @@ static int ftrace_profile_enable_event(struct ftrace_event_call *event)
}
ret = event->profile_enable();
- if (!ret)
+ if (!ret) {
+ total_profile_count++;
return 0;
+ }
- kfree(trace_profile_buf_nmi);
fail_buf_nmi:
- kfree(trace_profile_buf);
+ if (!total_profile_count) {
+ kfree(trace_profile_buf_nmi);
+ kfree(trace_profile_buf);
+ trace_profile_buf_nmi = NULL;
+ trace_profile_buf = NULL;
+ }
fail_buf:
- total_profile_count--;
atomic_dec(&event->profile_count);
return ret;