[PATCH 1/1] workqueue: swap set_cpus_allowed_ptr() and PF_NO_SETAFFINITY

[Oleg Nesterov <oleg@redhat.com>]

Move the setting of PF_NO_SETAFFINITY up before set_cpus_allowed()
in create_worker(). Otherwise userland can change ->cpus_allowed
in between.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
---
 kernel/workqueue.c |    8 ++++----
 1 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index 987293d..775af74 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -1736,16 +1736,16 @@ static struct worker *create_worker(struct worker_pool *pool)
 	if (IS_ERR(worker->task))
 		goto fail;
 
+	set_user_nice(worker->task, pool->attrs->nice);
+
+	/* prevent userland from meddling with cpumask of workqueue workers */
+	worker->task->flags |= PF_NO_SETAFFINITY;
 	/*
 	 * set_cpus_allowed_ptr() will fail if the cpumask doesn't have any
 	 * online CPUs.  It'll be re-applied when any of the CPUs come up.
 	 */
-	set_user_nice(worker->task, pool->attrs->nice);
 	set_cpus_allowed_ptr(worker->task, pool->attrs->cpumask);
 
-	/* prevent userland from meddling with cpumask of workqueue workers */
-	worker->task->flags |= PF_NO_SETAFFINITY;
-
 	/*
 	 * The caller is responsible for ensuring %POOL_DISASSOCIATED
 	 * remains stable across this function.  See the comments above the
-- 
1.5.5.1