| commit | 113fc5a6e8c2288619ff7e8187a6f556b7e0d372 | |
| author | H. Peter Anvin <hpa@zytor.com> | |
| Wed, 28 Jul 2010 00:01:49 +0000 (27 17:01 -0700) | ||
| committer | H. Peter Anvin <hpa@zytor.com> | |
| Wed, 28 Jul 2010 00:14:02 +0000 (27 17:14 -0700) | ||
| tree | 84393467b2174c05e7240db72ffa55ce3da67a70 | treesnapshot (tar.gz zip) |
| parent | fc0f5ac8fe693d1b05f5a928cc48135d1c8b7f2e | commitdiff |
x86: Add memory modify constraints to xchg() and cmpxchg()
xchg() and cmpxchg() modify their memory operands, not merely read
them. For some versions of gcc the "memory" clobber has apparently
dealt with the situation, but not for all.
Originally-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Cc: Glauber Costa <glommer@redhat.com>
Cc: Avi Kivity <avi@redhat.com>
Cc: Peter Palfrader <peter@palfrader.org>
Cc: Greg KH <gregkh@suse.de>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Zachary Amsden <zamsden@redhat.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: <stable@kernel.org>
LKML-Reference: <4C4F7277.8050306@zytor.com>
xchg() and cmpxchg() modify their memory operands, not merely read
them. For some versions of gcc the "memory" clobber has apparently
dealt with the situation, but not for all.
Originally-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Cc: Glauber Costa <glommer@redhat.com>
Cc: Avi Kivity <avi@redhat.com>
Cc: Peter Palfrader <peter@palfrader.org>
Cc: Greg KH <gregkh@suse.de>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Zachary Amsden <zamsden@redhat.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: <stable@kernel.org>
LKML-Reference: <4C4F7277.8050306@zytor.com>
| arch/x86/include/asm/cmpxchg_32.h | diffblobblamehistory | |
| arch/x86/include/asm/cmpxchg_64.h | diffblobblamehistory |