[ 37/66] wake_up_process() should be never used to wakeup a TASK_STOPPED/TRACED task

[Ben Hutchings <ben@decadent.org.uk>]

3.2-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Oleg Nesterov <oleg@redhat.com>

commit 9067ac85d533651b98c2ff903182a20cbb361fcb upstream.

wake_up_process() should never wakeup a TASK_STOPPED/TRACED task.
Change it to use TASK_NORMAL and add the WARN_ON().

TASK_ALL has no other users, probably can be killed.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
[bwh: Backported to 3.2: adjust filename]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---
 kernel/sched/core.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -2924,7 +2924,8 @@ out:
  */
 int wake_up_process(struct task_struct *p)
 {
-	return try_to_wake_up(p, TASK_ALL, 0);
+	WARN_ON(task_is_stopped_or_traced(p));
+	return try_to_wake_up(p, TASK_NORMAL, 0);
 }
 EXPORT_SYMBOL(wake_up_process);