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| author | Christoph Lameter <cl@linux.com> | 2011-03-26 20:57:18 -0500 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2011-03-27 19:25:36 -0700 |
| commit | d7c3f8cee81f4548de0513403b74131aee655576 (patch) | |
| tree | 3512188d9be3e429284d094d4bc1fdc2299b92db /arch/x86/lib | |
| parent | 76597cd31470fa130784c78fadb4dab2e624a723 (diff) | |
| download | linux-3.10-d7c3f8cee81f4548de0513403b74131aee655576.tar.gz linux-3.10-d7c3f8cee81f4548de0513403b74131aee655576.tar.bz2 linux-3.10-d7c3f8cee81f4548de0513403b74131aee655576.zip | |
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 <cl@linux.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'arch/x86/lib')
| -rw-r--r-- | arch/x86/lib/cmpxchg16b_emu.S | 14 |
1 files changed, 10 insertions, 4 deletions
diff --git a/arch/x86/lib/cmpxchg16b_emu.S b/arch/x86/lib/cmpxchg16b_emu.S index 3e8b08a6de2..1e572c507d0 100644 --- a/arch/x86/lib/cmpxchg16b_emu.S +++ b/arch/x86/lib/cmpxchg16b_emu.S @@ -10,6 +10,12 @@ #include <asm/frame.h> #include <asm/dwarf2.h> +#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 |