[patch 01/26] x86: fix csum_ipv6_magic asm memory clobber

Greg KH
2009-10-09T23:16:46Z

[-- Attachment #1: x86-fix-csum_ipv6_magic-asm-memory-clobber.patch --]
[-- Type: text/plain, Size: 1411 bytes --]

2.6.31-stable review patch. If anyone has any objections, please let us know.

------------------
From: Samuel Thibault <samuel.thibault@ens-lyon.org>

commit 392d814daf460a9564d29b2cebc51e1ea34e0504 upstream.

Just like ip_fast_csum, the assembly snippet in csum_ipv6_magic needs a
memory clobber, as it is only passed the address of the buffer, not a
memory reference to the buffer itself.

This caused failures in Hurd's pfinetv4 when we tried to compile it with
gcc-4.3 (bogus checksums).

Signed-off-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Acked-by: "David S. Miller" <davem@davemloft.net>
Cc: Andi Kleen <andi@firstfloor.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

---
arch/x86/include/asm/checksum_32.h | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

--- a/arch/x86/include/asm/checksum_32.h
+++ b/arch/x86/include/asm/checksum_32.h
@@ -161,7 +161,8 @@ static inline __sum16 csum_ipv6_magic(co
"adcl $0, %0 ;\n"
: "=&r" (sum)
: "r" (saddr), "r" (daddr),
- "r" (htonl(len)), "r" (htonl(proto)), "0" (sum));
+ "r" (htonl(len)), "r" (htonl(proto)), "0" (sum)
+ : "memory");

return csum_fold(sum);
}