mm/vmalloc.c: fix memory ordering bug
Read memory barriers must follow the read operations.
Signed-off-by: Dmitry Vyukov <dvyukov@google.com>
Cc: Eric Dumazet <edumazet@google.com>
Acked-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index 8a18196..39c3388 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -2574,10 +2574,10 @@
if (!counters)
return;
- /* Pair with smp_wmb() in clear_vm_uninitialized_flag() */
- smp_rmb();
if (v->flags & VM_UNINITIALIZED)
return;
+ /* Pair with smp_wmb() in clear_vm_uninitialized_flag() */
+ smp_rmb();
memset(counters, 0, nr_node_ids * sizeof(unsigned int));