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authorLinus Torvalds <torvalds@macmini.osdl.org>2006-07-09 00:24:18 +0200
committerLinus Torvalds <torvalds@macmini.osdl.org>2006-07-09 00:24:18 +0200
commitb862f3b099f3ea672c7438c0b282ce8201d39dfc (patch)
tree62f8cc2dc2b1c9abb6364b16f3b218a04d121f3e /include/asm-i386/rwlock.h
parentpower: improve inline asm memory constraints (diff)
downloadlinux-b862f3b099f3ea672c7438c0b282ce8201d39dfc.tar.xz
linux-b862f3b099f3ea672c7438c0b282ce8201d39dfc.zip
i386: improve and correct inline asm memory constraints
Use "+m" rather than a combination of "=m" and "m" for improved clarity and consistency. This also fixes some inlines that incorrectly didn't tell the compiler that they read the old value at all, potentially causing the compiler to generate bogus code. It appear that all of those potential bugs were hidden by the use of extra "volatile" specifiers on the data structures in question, though. Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'include/asm-i386/rwlock.h')
-rw-r--r--include/asm-i386/rwlock.h4
1 files changed, 2 insertions, 2 deletions
diff --git a/include/asm-i386/rwlock.h b/include/asm-i386/rwlock.h
index 94f00195d543..96b0bef2ea56 100644
--- a/include/asm-i386/rwlock.h
+++ b/include/asm-i386/rwlock.h
@@ -37,7 +37,7 @@
"popl %%eax\n\t" \
"1:\n", \
"subl $1,%0\n\t", \
- "=m" (*(volatile int *)rw) : : "memory")
+ "+m" (*(volatile int *)rw) : : "memory")
#define __build_read_lock(rw, helper) do { \
if (__builtin_constant_p(rw)) \
@@ -63,7 +63,7 @@
"popl %%eax\n\t" \
"1:\n", \
"subl $" RW_LOCK_BIAS_STR ",%0\n\t", \
- "=m" (*(volatile int *)rw) : : "memory")
+ "+m" (*(volatile int *)rw) : : "memory")
#define __build_write_lock(rw, helper) do { \
if (__builtin_constant_p(rw)) \