tracing/filters: add missing unlock in a failure path

[ Impact: fix deadlock in a rare case we fail to allocate memory ]

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
LKML-Reference: <4A0CDC6F.7070200@cn.fujitsu.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

1 files changed, 6 insertions, 4 deletions

diff --git a/kernel/trace/trace_events_filter.c b/kernel/trace/trace_events_filter.c
index 85ad6a8939ad..22c29984fe0e 100644
--- a/kernel/trace/trace_events_filter.c
+++ b/kernel/trace/trace_events_filter.c
@@ -1079,9 +1079,10 @@ int apply_event_filter(struct ftrace_event_call *call, char *filter_string)
                 return 0;
         }
 
+        err = -ENOMEM;
         ps = kzalloc(sizeof(*ps), GFP_KERNEL);
         if (!ps)
-                return -ENOMEM;
+                goto out_unlock;
 
         filter_disable_preds(call);
         replace_filter_string(call->filter, filter_string);
@@ -1101,7 +1102,7 @@ out:
         filter_opstack_clear(ps);
         postfix_clear(ps);
         kfree(ps);
-
+out_unlock:
         mutex_unlock(&filter_mutex);
 
         return err;
@@ -1123,9 +1124,10 @@ int apply_subsystem_event_filter(struct event_subsystem *system,
                 return 0;
         }
 
+        err = -ENOMEM;
         ps = kzalloc(sizeof(*ps), GFP_KERNEL);
         if (!ps)
-                return -ENOMEM;
+                goto out_unlock;
 
         filter_free_subsystem_preds(system);
         replace_filter_string(system->filter, filter_string);
@@ -1145,7 +1147,7 @@ out:
         filter_opstack_clear(ps);
         postfix_clear(ps);
         kfree(ps);
-
+out_unlock:
         mutex_unlock(&filter_mutex);
 
         return err;