Merge branch 'tracing-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

* 'tracing-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  ftrace: do_each_pid_task() needs rcu lock

1 files changed, 5 insertions, 0 deletions

diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 7dcf6e9f2b04..9a236ffe2aa4 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -1737,9 +1737,12 @@ static void clear_ftrace_pid(struct pid *pid)
 {
         struct task_struct *p;
 
+        rcu_read_lock();
         do_each_pid_task(pid, PIDTYPE_PID, p) {
                 clear_tsk_trace_trace(p);
         } while_each_pid_task(pid, PIDTYPE_PID, p);
+        rcu_read_unlock();
+
         put_pid(pid);
 }
 
@@ -1747,9 +1750,11 @@ static void set_ftrace_pid(struct pid *pid)
 {
         struct task_struct *p;
 
+        rcu_read_lock();
         do_each_pid_task(pid, PIDTYPE_PID, p) {
                 set_tsk_trace_trace(p);
         } while_each_pid_task(pid, PIDTYPE_PID, p);
+        rcu_read_unlock();
 }
 
 static void clear_ftrace_pid_task(struct pid **pid)