[3.13.y.z extended stable] Patch "kthread: fix return value of kthread_create() upon SIGKILL." has been added to staging queue

[Kamal Mostafa]

This is a note to let you know that I have just added a patch titled

    kthread: fix return value of kthread_create() upon SIGKILL.

to the linux-3.13.y-queue branch of the 3.13.y.z extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.13.y-queue

This patch is scheduled to be released in version 3.13.11.5.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.13.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Kamal

------

>From 949038551b4ed910a49f136602e3f5aba217dc0c Mon Sep 17 00:00:00 2001
From: Tetsuo Handa <penguin-kernel at i-love.sakura.ne.jp>
Date: Wed, 4 Jun 2014 16:05:36 -0700
Subject: kthread: fix return value of kthread_create() upon SIGKILL.

commit 8fe6929cfd43c44834858a53e129ffdc7c166298 upstream.

Commit 786235eeba0e ("kthread: make kthread_create() killable") meant
for allowing kthread_create() to abort as soon as killed by the
OOM-killer.  But returning -ENOMEM is wrong if killed by SIGKILL from
userspace.  Change kthread_create() to return -EINTR upon SIGKILL.

Signed-off-by: Tetsuo Handa <penguin-kernel at I-love.SAKURA.ne.jp>
Cc: Oleg Nesterov <oleg at redhat.com>
Acked-by: David Rientjes <rientjes at google.com>
Signed-off-by: Andrew Morton <akpm at linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds at linux-foundation.org>
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
 kernel/kthread.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/kernel/kthread.c b/kernel/kthread.c
index b5ae3ee..f6249f9 100644
--- a/kernel/kthread.c
+++ b/kernel/kthread.c
@@ -262,7 +262,7 @@ static void create_kthread(struct kthread_create_info *create)
  * kthread_stop() has been called).  The return value should be zero
  * or a negative error number; it will be passed to kthread_stop().
  *
- * Returns a task_struct or ERR_PTR(-ENOMEM).
+ * Returns a task_struct or ERR_PTR(-ENOMEM) or ERR_PTR(-EINTR).
  */
 struct task_struct *kthread_create_on_node(int (*threadfn)(void *data),
 					   void *data, int node,
@@ -298,7 +298,7 @@ struct task_struct *kthread_create_on_node(int (*threadfn)(void *data),
 		 * that thread.
 		 */
 		if (xchg(&create->done, NULL))
-			return ERR_PTR(-ENOMEM);
+			return ERR_PTR(-EINTR);
 		/*
 		 * kthreadd (or new kernel thread) will call complete()
 		 * shortly.
--
1.9.1