x86: Properly parenthesize cmpxchg() macro arguments
authorJan Beulich <JBeulich@suse.com>
Thu, 26 Jan 2012 15:47:37 +0000 (15:47 +0000)
committerIngo Molnar <mingo@elte.hu>
Thu, 26 Jan 2012 20:18:29 +0000 (21:18 +0100)
Quite oddly, all of the arguments passed through from the top
level macros to the second level which didn't need parentheses
had them, while the only expression (involving a parameter)
needing them didn't.

Very recently I got bitten by the lack thereof when using
something like "array + index" for the first operand, with
"array" being an array more narrow than int.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/4F2183A9020000780006F3E6@nat28.tlf.novell.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
arch/x86/include/asm/cmpxchg.h

index 0c9fa27..b3b7332 100644 (file)
@@ -145,13 +145,13 @@ extern void __add_wrong_size(void)
 
 #ifdef __HAVE_ARCH_CMPXCHG
 #define cmpxchg(ptr, old, new)                                         \
-       __cmpxchg((ptr), (old), (new), sizeof(*ptr))
+       __cmpxchg(ptr, old, new, sizeof(*(ptr)))
 
 #define sync_cmpxchg(ptr, old, new)                                    \
-       __sync_cmpxchg((ptr), (old), (new), sizeof(*ptr))
+       __sync_cmpxchg(ptr, old, new, sizeof(*(ptr)))
 
 #define cmpxchg_local(ptr, old, new)                                   \
-       __cmpxchg_local((ptr), (old), (new), sizeof(*ptr))
+       __cmpxchg_local(ptr, old, new, sizeof(*(ptr)))
 #endif
 
 /*