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x86: add memory clobber to save/loadsegment

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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>
Cc: xen-devel <xen-devel@lists.xensource.com>
Cc: Stephen Tweedie <sct@redhat.com>
Cc: Eduardo Habkost <ehabkost@redhat.com>
Cc: Mark McLoughlin <markmc@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This commit is contained in:
Jeremy Fitzhardinge 2008-06-25 00:18:58 -04:00 committed by Ingo Molnar
parent bea41808ef
commit d338c73c39
1 changed files with 2 additions and 2 deletions
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4
include/asm-x86/system.h
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@ -153,14 +153,14 @@ extern void load_gs_index(unsigned);
"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)
{