From 7e5b528b4ce31208ef5c240c14beec4853d8262c Mon Sep 17 00:00:00 2001
From: Dmitry Vyukov <dvyukov@google.com>
Date: Fri, 12 Dec 2014 16:56:30 -0800
Subject: 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>
---
 mm/vmalloc.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

(limited to 'mm')

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 @@ static void show_numa_info(struct seq_file *m, struct vm_struct *v)
 		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));
 
-- 
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