tracing: Fix sparse RCU warning

p_start() and p_stop() are seq_file functions that match. Teach sparse to
know that rcu_read_lock_sched() that is taken by p_start() is released by
p_stop.

Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

1 files changed, 2 insertions, 0 deletions

diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c
index 2b7fccd499c6..fb0261e90acc 100644
--- a/kernel/trace/trace_events.c
+++ b/kernel/trace/trace_events.c
@@ -938,6 +938,7 @@ static void t_stop(struct seq_file *m, void *p)
 }
 
 static void *p_start(struct seq_file *m, loff_t *pos)
+        __acquires(RCU)
 {
         struct trace_pid_list *pid_list;
         struct trace_array *tr = m->private;
@@ -960,6 +961,7 @@ static void *p_start(struct seq_file *m, loff_t *pos)
 }
 
 static void p_stop(struct seq_file *m, void *p)
+        __releases(RCU)
 {
         rcu_read_unlock_sched();
         mutex_unlock(&event_mutex);