[PATCH] x86: properly parenthesize cmpxchg() macro arguments

[PATCH] x86: properly parenthesize cmpxchg() macro arguments

[Jan Beulich]

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>

---
 arch/x86/include/asm/cmpxchg.h |    6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

--- 3.3-rc1/arch/x86/include/asm/cmpxchg.h
+++ 3.3-rc1-x86-cmpxchg-parenthesize/arch/x86/include/asm/cmpxchg.h
@@ -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
 
 /*

[tip:x86/urgent] x86: Properly parenthesize cmpxchg() macro arguments

[tip-bot for Jan Beulich]

Commit-ID:  fc395b9291925b1880e0afc61274fe2f6ddc1269
Gitweb:     http://git.kernel.org/tip/fc395b9291925b1880e0afc61274fe2f6ddc1269
Author:     Jan Beulich <JBeulich@suse.com>
AuthorDate: Thu, 26 Jan 2012 15:47:37 +0000
Committer:  Ingo Molnar <mingo@elte.hu>
CommitDate: Thu, 26 Jan 2012 21:18:29 +0100

x86: Properly parenthesize cmpxchg() macro arguments

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 |    6 +++---
 1 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/arch/x86/include/asm/cmpxchg.h b/arch/x86/include/asm/cmpxchg.h
index 0c9fa27..b3b7332 100644
--- a/arch/x86/include/asm/cmpxchg.h
+++ b/arch/x86/include/asm/cmpxchg.h
@@ -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
 
 /*