1 files changed, 6 insertions, 1 deletions

diff --git a/include/linux/rculist_nulls.h b/include/linux/rculist_nulls.h
index 2ae13714828b..1c33dd7da4a7 100644
--- a/include/linux/rculist_nulls.h
+++ b/include/linux/rculist_nulls.h
@@ -105,9 +105,14 @@ static inline void hlist_nulls_add_head_rcu(struct hlist_nulls_node *n,
  * @head:       the head for your list.
  * @member:     the name of the hlist_nulls_node within the struct.
  *
+ * The barrier() is needed to make sure compiler doesn't cache first element [1],
+ * as this loop can be restarted [2]
+ * [1] Documentation/atomic_ops.txt around line 114
+ * [2] Documentation/RCU/rculist_nulls.txt around line 146
  */
 #define hlist_nulls_for_each_entry_rcu(tpos, pos, head, member)                 \
-        for (pos = rcu_dereference_raw(hlist_nulls_first_rcu(head));            \
+        for (({barrier();}),                                                    \
+             pos = rcu_dereference_raw(hlist_nulls_first_rcu(head));            \
                 (!is_a_nulls(pos)) &&                                           \
                 ({ tpos = hlist_nulls_entry(pos, typeof(*tpos), member); 1; }); \
                 pos = rcu_dereference_raw(hlist_nulls_next_rcu(pos)))