tracing: Fix failure path in ftrace_graph_write()

Don't call trace_parser_put() on uninitialized trace_parser.

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
LKML-Reference: <4AB86639.3000003@cn.fujitsu.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 6 insertions, 4 deletions

diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index a8fe4782ebad..5c5cb9be8e8c 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -2561,12 +2561,12 @@ ftrace_graph_write(struct file *file, const char __user *ubuf,
 
         if (ftrace_graph_count >= FTRACE_GRAPH_MAX_FUNCS) {
                 ret = -EBUSY;
-                goto out;
+                goto out_unlock;
         }
 
         if (trace_parser_get_init(&parser, FTRACE_BUFF_MAX)) {
                 ret = -ENOMEM;
-                goto out;
+                goto out_unlock;
         }
 
         read = trace_get_user(&parser, ubuf, cnt, ppos);
@@ -2578,12 +2578,14 @@ ftrace_graph_write(struct file *file, const char __user *ubuf,
                 ret = ftrace_set_func(ftrace_graph_funcs, &ftrace_graph_count,
                                         parser.buffer);
                 if (ret)
-                        goto out;
+                        goto out_free;
         }
 
         ret = read;
- out:
+
+out_free:
         trace_parser_put(&parser);
+out_unlock:
         mutex_unlock(&graph_lock);
 
         return ret;