Merge tag 'trace-fixes-v3.15-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

torvalds · torvalds · commit 00622e61eda4 · 2014-05-03T08:30:44.000-07:00
Pull tracing fix from Steven Rostedt:
 "This is a small fix where the trigger code used the wrong
  rcu_dereference().  It required rcu_dereference_sched() instead of the
  normal rcu_dereference().  It produces a nasty RCU lockdep splat due
  to the incorrect rcu notation"

Acked-by: Paul E. McKenney &lt;paulmck@linux.vnet.ibm.com&gt;

* tag 'trace-fixes-v3.15-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  tracing: Use rcu_dereference_sched() for trace event triggers
diff --git a/kernel/trace/trace_events_trigger.c b/kernel/trace/trace_events_trigger.c
@@ -77,7 +77,7 @@ event_triggers_call(struct ftrace_event_file *file, void *rec)
 			data->ops->func(data);
 			continue;
 		}
-		filter = rcu_dereference(data->filter);
+		filter = rcu_dereference_sched(data->filter);
 		if (filter && !filter_match_preds(filter, rec))
 			continue;
 		if (data->cmd_ops->post_trigger) {

Original file line number	Diff line number	Diff line change
`@@ -77,7 +77,7 @@ event_triggers_call(struct ftrace_event_file file, void rec)`
`77`	`77`	`data->ops->func(data);`
`78`	`78`	`continue;`
`79`	`79`	`}`
`80`		`- filter = rcu_dereference(data->filter);`
	`80`	`+ filter = rcu_dereference_sched(data->filter);`
`81`	`81`	`if (filter && !filter_match_preds(filter, rec))`
`82`	`82`	`continue;`
`83`	`83`	`if (data->cmd_ops->post_trigger) {`