[v2.6.34-stable 089/213] wake_up_process() should be never used to wakeup a TASK_STOPPED/TRACED task

[Paul Gortmaker]

From: Oleg Nesterov <oleg@xxxxxxxxxx>

                   -------------------
    This is a commit scheduled for the next v2.6.34 longterm release.
    http://git.kernel.org/?p=linux/kernel/git/paulg/longterm-queue-2.6.34.git
    If you see a problem with using this for longterm, please comment.
                   -------------------

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@xxxxxxxxxx>
Signed-off-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
[PG: kernel/sched/core.c --> kernel/sched.c on 2.6.34]
Signed-off-by: Paul Gortmaker <paul.gortmaker@xxxxxxxxxxxxx>
---
 kernel/sched.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/kernel/sched.c b/kernel/sched.c
index e24d139ff694..ddcb8aeb2f59 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -2492,7 +2492,8 @@ 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);
 
-- 
1.8.5.2

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