1 files changed, 9 insertions, 1 deletions

diff --git a/kernel/stop_machine.c b/kernel/stop_machine.c
index 1ff523dae6e2..e190d1ef3a23 100644
--- a/kernel/stop_machine.c
+++ b/kernel/stop_machine.c
@@ -260,6 +260,15 @@ retry:
         err = 0;
         __cpu_stop_queue_work(stopper1, work1, &wakeq);
         __cpu_stop_queue_work(stopper2, work2, &wakeq);
+        /*
+         * The waking up of stopper threads has to happen
+         * in the same scheduling context as the queueing.
+         * Otherwise, there is a possibility of one of the
+         * above stoppers being woken up by another CPU,
+         * and preempting us. This will cause us to n ot
+         * wake up the other stopper forever.
+         */
+        preempt_disable();
 unlock:
         raw_spin_unlock(&stopper2->lock);
         raw_spin_unlock_irq(&stopper1->lock);
@@ -271,7 +280,6 @@ unlock:
         }
 
         if (!err) {
-                preempt_disable();
                 wake_up_q(&wakeq);
                 preempt_enable();
         }