[PATCH v2] mm/huge_memory: mark racy access on huge_anon_orders_always

[PATCH v2] mm/huge_memory: mark racy access on huge_anon_orders_always

[xu.xin16]

From: Ran Xiaokai <ran.xiaokai@zte.com.cn>

huge_anon_orders_always is accessed lockless, it is better
to use the READ_ONCE() wrapper. This is not fixing any visible
bug, hopefully this can cease some KCSAN complains in the future.
Also do that for huge_anon_orders_madvise.

Signed-off-by: Ran Xiaokai <ran.xiaokai@zte.com.cn>
Acked-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Lu Zhongjun <lu.zhongjun@zte.com.cn>
Reviewed-by: xu xin <xu.xin16@zte.com.cn>
Cc: Yang Yang <yang.yang29@zte.com.cn>
---
 include/linux/huge_mm.h | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/include/linux/huge_mm.h b/include/linux/huge_mm.h
index de0c89105076..cf7f671aa634 100644
--- a/include/linux/huge_mm.h
+++ b/include/linux/huge_mm.h
@@ -122,8 +122,8 @@ static inline bool hugepage_flags_enabled(void)
 	 * So we don't need to look at huge_anon_orders_inherit.
 	 */
 	return hugepage_global_enabled() ||
-	       huge_anon_orders_always ||
-	       huge_anon_orders_madvise;
+	       READ_ONCE(huge_anon_orders_always) ||
+	       READ_ONCE(huge_anon_orders_madvise);
 }

 static inline int highest_order(unsigned long orders)
-- 
2.15.2