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Subject[tip:x86/asm] x86: Fix atomic64_xxx_cx8() functions
Commit-ID:  ceb7b40b65539a771d1bfaf47660ac0ee57e0c4f
Gitweb: http://git.kernel.org/tip/ceb7b40b65539a771d1bfaf47660ac0ee57e0c4f
Author: Eric Dumazet <eric.dumazet@gmail.com>
AuthorDate: Tue, 3 Jan 2012 17:35:40 +0100
Committer: Ingo Molnar <mingo@elte.hu>
CommitDate: Wed, 4 Jan 2012 15:01:56 +0100

x86: Fix atomic64_xxx_cx8() functions

It appears about all functions in arch/x86/lib/atomic64_cx8_32.S
are wrong in case cmpxchg8b must be restarted, because
LOCK_PREFIX macro defines a label "1" clashing with other local
labels :

1:
some_instructions
LOCK_PREFIX
cmpxchg8b (%ebp)
jne 1b / jumps to beginning of LOCK_PREFIX !

A possible fix is to use a magic label "672" in LOCK_PREFIX asm
definition, similar to the "671" one we defined in
LOCK_PREFIX_HERE.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Acked-by: Jan Beulich <JBeulich@suse.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: http://lkml.kernel.org/r/1325608540.2320.103.camel@edumazet-HP-Compaq-6005-Pro-SFF-PC
Signed-off-by: Ingo Molnar <mingo@elte.hu>
---
arch/x86/include/asm/alternative-asm.h | 4 ++--
1 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/x86/include/asm/alternative-asm.h b/arch/x86/include/asm/alternative-asm.h
index 091508b..952bd01 100644
--- a/arch/x86/include/asm/alternative-asm.h
+++ b/arch/x86/include/asm/alternative-asm.h
@@ -4,10 +4,10 @@

#ifdef CONFIG_SMP
.macro LOCK_PREFIX
-1: lock
+672: lock
.section .smp_locks,"a"
.balign 4
- .long 1b - .
+ .long 672b - .
.previous
.endm
#else

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