Commit 2fac6f3f authored Apr 25, 2005 by Deepak Saxena Committed by Russell King Apr 25, 2005

[PATCH] ARM: 2653/1: Fix memset and memzero macro double-reference of parameters

Patch from Deepak Saxena

The current memset() and memzero() macros on ARM reference the
incoming parameters more than once and this can cause uninted
side-effects. The issue was found while debugging SCTP protocol
and with the specific usage of memzero(skb_put(skb,size),size).
This call would call skb_put(skb,size) twice leading to badness.
The fixed version copies the incoming parameters into local
variables and uses those instead.

Signed-off-by: Deepak Saxena
Signed-off-by: Russell King

parent 41130d37

include/asm-arm/string.h

+12 −5

Original line number	Diff line number	Diff line
		@@ -29,15 +29,22 @@ extern void __memzero(void *ptr, __kernel_size_t n);

		#define memset(p,v,n) \
		({ \
		if ((n) != 0) { \
		void *__p = (p); size_t __n = n; \
		if ((__n) != 0) { \
		if (__builtin_constant_p((v)) && (v) == 0) \
		__memzero((p),(n)); \
		__memzero((__p),(__n)); \
		else \
		memset((p),(v),(n)); \
		memset((__p),(v),(__n)); \
		} \
		(p); \
		(__p); \
		})

		#define memzero(p,n) ({ if ((n) != 0) __memzero((p),(n)); (p); })
		#define memzero(p,n) \
		({ \
		void *__p = (p); size_t __n = n; \
		if ((__n) != 0) \
		__memzero((__p),(__n)); \
		(__p); \
		})

		#endif

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