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>
diff --git a/include/asm-i386/semaphore.h b/include/asm-i386/semaphore.h
index f7a0f31..d51e800 100644
--- a/include/asm-i386/semaphore.h
+++ b/include/asm-i386/semaphore.h
@@ -107,7 +107,7 @@
"call __down_failed\n\t"
"jmp 1b\n"
LOCK_SECTION_END
- :"=m" (sem->count)
+ :"+m" (sem->count)
:
:"memory","ax");
}
@@ -132,7 +132,7 @@
"call __down_failed_interruptible\n\t"
"jmp 1b\n"
LOCK_SECTION_END
- :"=a" (result), "=m" (sem->count)
+ :"=a" (result), "+m" (sem->count)
:
:"memory");
return result;
@@ -157,7 +157,7 @@
"call __down_failed_trylock\n\t"
"jmp 1b\n"
LOCK_SECTION_END
- :"=a" (result), "=m" (sem->count)
+ :"=a" (result), "+m" (sem->count)
:
:"memory");
return result;
@@ -182,7 +182,7 @@
"jmp 1b\n"
LOCK_SECTION_END
".subsection 0\n"
- :"=m" (sem->count)
+ :"+m" (sem->count)
:
:"memory","ax");
}