From d7c3f8cee81f4548de0513403b74131aee655576 Mon Sep 17 00:00:00 2001 From: Christoph Lameter Date: Sat, 26 Mar 2011 20:57:18 -0500 Subject: percpu: Omit segment prefix in the UP case for cmpxchg_double Omit the segment prefix in the UP case. GS is not used then and we will generate segfaults if cmpxchg16b is used otherwise. Signed-off-by: Christoph Lameter Signed-off-by: Linus Torvalds --- arch/x86/lib/cmpxchg16b_emu.S | 14 ++++++++++---- 1 file changed, 10 insertions(+), 4 deletions(-) (limited to 'arch/x86/lib') diff --git a/arch/x86/lib/cmpxchg16b_emu.S b/arch/x86/lib/cmpxchg16b_emu.S index 3e8b08a6de2b..1e572c507d06 100644 --- a/arch/x86/lib/cmpxchg16b_emu.S +++ b/arch/x86/lib/cmpxchg16b_emu.S @@ -10,6 +10,12 @@ #include #include +#ifdef CONFIG_SMP +#define SEG_PREFIX %gs: +#else +#define SEG_PREFIX +#endif + .text /* @@ -37,13 +43,13 @@ this_cpu_cmpxchg16b_emu: pushf cli - cmpq %gs:(%rsi), %rax + cmpq SEG_PREFIX(%rsi), %rax jne not_same - cmpq %gs:8(%rsi), %rdx + cmpq SEG_PREFIX 8(%rsi), %rdx jne not_same - movq %rbx, %gs:(%rsi) - movq %rcx, %gs:8(%rsi) + movq %rbx, SEG_PREFIX(%rsi) + movq %rcx, SEG_PREFIX 8(%rsi) popf mov $1, %al -- cgit v1.2.3-59-g8ed1b