1 files changed, 14 insertions, 8 deletions

diff --git a/include/linux/preempt.h b/include/linux/preempt.h
index 5a710b9c578e..87a03c746f17 100644
--- a/include/linux/preempt.h
+++ b/include/linux/preempt.h
@@ -93,14 +93,20 @@ do { \
 
 #else /* !CONFIG_PREEMPT_COUNT */
 
-#define preempt_disable()               do { } while (0)
-#define sched_preempt_enable_no_resched()       do { } while (0)
-#define preempt_enable_no_resched()     do { } while (0)
-#define preempt_enable()                do { } while (0)
-
-#define preempt_disable_notrace()               do { } while (0)
-#define preempt_enable_no_resched_notrace()     do { } while (0)
-#define preempt_enable_notrace()                do { } while (0)
+/*
+ * Even if we don't have any preemption, we need preempt disable/enable
+ * to be barriers, so that we don't have things like get_user/put_user
+ * that can cause faults and scheduling migrate into our preempt-protected
+ * region.
+ */
+#define preempt_disable()               barrier()
+#define sched_preempt_enable_no_resched()       barrier()
+#define preempt_enable_no_resched()     barrier()
+#define preempt_enable()                barrier()
+
+#define preempt_disable_notrace()               barrier()
+#define preempt_enable_no_resched_notrace()     barrier()
+#define preempt_enable_notrace()                barrier()
 
 #endif /* CONFIG_PREEMPT_COUNT */