linux-kernel - [PATCH] x86: cmpxchg_double: Add missing memory clobber

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Date:	Tue,  6 Oct 2015 14:54:29 -0400
From:	Pranith Kumar <bobby.prani@...il.com>
To:	Thomas Gleixner <tglx@...utronix.de>,
	Ingo Molnar <mingo@...hat.com>,
	"H. Peter Anvin" <hpa@...or.com>,
	x86@...nel.org (maintainer:X86 ARCHITECTURE (32-BIT AND 64-BIT)),
	linux-kernel@...r.kernel.org (open list:X86 ARCHITECTURE (32-BIT AND
	64-BIT))
Subject: [PATCH] x86: cmpxchg_double: Add missing memory clobber

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@...il.com>
---
 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

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/