[PATCH] x86: cmpxchg_double: Add missing memory clobber

From: Pranith Kumar
Date: Tue Oct 06 2015 - 14:54:23 EST


We are reading from memory locations pointed to by p1 and p2 in the asm
block. Add a memory clobber flag to make gcc aware of this.

Signed-off-by: Pranith Kumar <bobby.prani@xxxxxxxxx>
---
arch/x86/include/asm/cmpxchg.h | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/arch/x86/include/asm/cmpxchg.h b/arch/x86/include/asm/cmpxchg.h
index 4a2e5bc..3e83949 100644
--- a/arch/x86/include/asm/cmpxchg.h
+++ b/arch/x86/include/asm/cmpxchg.h
@@ -214,7 +214,8 @@ extern void __add_wrong_size(void)
: "=a" (__ret), "+d" (__old2), \
"+m" (*(p1)), "+m" (*(p2)) \
: "i" (2 * sizeof(long)), "a" (__old1), \
- "b" (__new1), "c" (__new2)); \
+ "b" (__new1), "c" (__new2) \
+ : "memory"); \
__ret; \
})

--
2.5.3

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