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authorLi Zefan2009-08-24 06:19:47 +0200
committerSteven Rostedt2009-09-13 04:28:38 +0200
commit558e6547e4b8a2b13608a24a9d3679802f91c4c7 (patch)
treeaa7eeeee57fbf93d2ff3811a362ffef19be17c29 /kernel/trace/trace_event_profile.c
parenttracing/function-graph: x86_64 stack allocation cleanup (diff)
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tracing/profile: fix profile_disable vs module_unload
If the correspoding module is unloaded before ftrace_profile_disable() is called, event->profile_disable() won't be called, which can cause oops: # insmod trace-events-sample.ko # perf record -f -a -e sample:foo_bar sleep 3 & # sleep 1 # rmmod trace_events_sample # insmod trace-events-sample.ko OOPS! Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> LKML-Reference: <4A9214E3.2070807@cn.fujitsu.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Diffstat (limited to 'kernel/trace/trace_event_profile.c')
-rw-r--r--kernel/trace/trace_event_profile.c5
1 files changed, 4 insertions, 1 deletions
diff --git a/kernel/trace/trace_event_profile.c b/kernel/trace/trace_event_profile.c
index 11ba5bb4ed0a..55a25c933d15 100644
--- a/kernel/trace/trace_event_profile.c
+++ b/kernel/trace/trace_event_profile.c
@@ -5,6 +5,7 @@
*
*/
+#include <linux/module.h>
#include "trace.h"
int ftrace_profile_enable(int event_id)
@@ -14,7 +15,8 @@ int ftrace_profile_enable(int event_id)
mutex_lock(&event_mutex);
list_for_each_entry(event, &ftrace_events, list) {
- if (event->id == event_id && event->profile_enable) {
+ if (event->id == event_id && event->profile_enable &&
+ try_module_get(event->mod)) {
ret = event->profile_enable(event);
break;
}
@@ -32,6 +34,7 @@ void ftrace_profile_disable(int event_id)
list_for_each_entry(event, &ftrace_events, list) {
if (event->id == event_id) {
event->profile_disable(event);
+ module_put(event->mod);
break;
}
}