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>

diff --git a/kernel/trace/trace_events_filter.c b/kernel/trace/trace_events_filter.c
index 85ad6a8939ad2ea01df946bfe31f3f020f7b56bf..22c29984fe0e708d31e222acb6bbe569fd1623e9 100644 (file)
--- 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;