[PATCH 02 of 36] x86: add memory clobber to save/loadsegment

Jeremy Fitzhardinge
2008-06-25T04:37:25Z

Add "memory" clobbers to savesegment and loadsegment, since they can
affect memory accesses and we never want the compiler to reorder them
with respect to memory references.

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
---
include/asm-x86/system.h | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/include/asm-x86/system.h b/include/asm-x86/system.h
--- a/include/asm-x86/system.h
+++ b/include/asm-x86/system.h
@@ -157,14 +157,14 @@
"jmp 2b\n" \
".previous\n" \
_ASM_EXTABLE(1b,3b) \
- : :"r" (value), "r" (0))
+ : :"r" (value), "r" (0) : "memory")

/*
* Save a segment register away
*/
#define savesegment(seg, value) \
- asm volatile("mov %%" #seg ",%0":"=rm" (value))
+ asm("mov %%" #seg ",%0":"=rm" (value) : : "memory")

static inline unsigned long get_limit(unsigned long segment)
{