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authorTejun Heo <tj@kernel.org>2011-11-23 08:49:49 -0800
committerSteven Rostedt <rostedt@goodmis.org>2011-12-01 22:16:47 -0500
commitd3d9acf646679c1981032b0985b386d12fccc60c (patch)
tree68df9e100ae7304a1384160b5d1b068241f4d1fe
parent4a1dba72384193753e44e15d9d05a50be6587271 (diff)
downloadlwn-d3d9acf646679c1981032b0985b386d12fccc60c.tar.gz
lwn-d3d9acf646679c1981032b0985b386d12fccc60c.zip
trace_events_filter: Use rcu_assign_pointer() when setting ftrace_event_call->filter
ftrace_event_call->filter is sched RCU protected but didn't use rcu_assign_pointer(). Use it. TODO: Add proper __rcu annotation to call->filter and all its users. -v2: Use RCU_INIT_POINTER() for %NULL clearing as suggested by Eric. Link: http://lkml.kernel.org/r/20111123164949.GA29639@google.com Cc: Eric Dumazet <eric.dumazet@gmail.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: stable@kernel.org # (2.6.39+) Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
-rw-r--r--kernel/trace/trace_events_filter.c6
1 files changed, 3 insertions, 3 deletions
diff --git a/kernel/trace/trace_events_filter.c b/kernel/trace/trace_events_filter.c
index 816d3d074979..d6e7926dcd26 100644
--- a/kernel/trace/trace_events_filter.c
+++ b/kernel/trace/trace_events_filter.c
@@ -1686,7 +1686,7 @@ static int replace_system_preds(struct event_subsystem *system,
* replace the filter for the call.
*/
filter = call->filter;
- call->filter = filter_item->filter;
+ rcu_assign_pointer(call->filter, filter_item->filter);
filter_item->filter = filter;
fail = false;
@@ -1741,7 +1741,7 @@ int apply_event_filter(struct ftrace_event_call *call, char *filter_string)
filter = call->filter;
if (!filter)
goto out_unlock;
- call->filter = NULL;
+ RCU_INIT_POINTER(call->filter, NULL);
/* Make sure the filter is not being used */
synchronize_sched();
__free_filter(filter);
@@ -1782,7 +1782,7 @@ out:
* string
*/
tmp = call->filter;
- call->filter = filter;
+ rcu_assign_pointer(call->filter, filter);
if (tmp) {
/* Make sure the call is done with the filter */
synchronize_sched();