workqueue: lock cwq access in drain_workqueue

[firefly-linux-kernel-4.4.55.git] / kernel / workqueue.c

diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index 0400553f0d049807d109e9cc87d7a5dc2c0dcc99..aec02b6a1c4a4b70ae0eb1c15fc40b93b726c849 100644 (file)
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -3026,8 +3026,13 @@ reflush:
 
        for_each_cwq_cpu(cpu, wq) {
                struct cpu_workqueue_struct *cwq = get_cwq(cpu, wq);
+               bool drained;
 
-               if (!cwq->nr_active && list_empty(&cwq->delayed_works))
+               spin_lock_irq(&cwq->gcwq->lock);
+               drained = !cwq->nr_active && list_empty(&cwq->delayed_works);
+               spin_unlock_irq(&cwq->gcwq->lock);
+
+               if (drained)
                        continue;
 
                if (++flush_cnt == 10 ||