asm-generic: {get,put}_user ptr argument evaluate only 1 time (a02613a4) · Commits · 戴 / test

Current implemantation ptr argument evaluate 2 times. It'll be an unexpected result. Changes v5: Remove unnecessary const. Changes v4: Temporary pointer type change to const void* Changes v3: Some build error fix. Changes v2: Argument x protect. Signed-off-by:

Yoshinori Sato <ysato@users.sourceforge.jp>

include/asm-generic/uaccess.h

+6 −4

Original line number	Diff line number	Diff line
		@@ -163,9 +163,10 @@ static inline __must_check long __copy_to_user(void __user *to,

		#define put_user(x, ptr) \
		({ \
		void *__p = (ptr); \
		might_fault(); \
		access_ok(VERIFY_WRITE, ptr, sizeof(*ptr)) ? \
		__put_user(x, ptr) : \
		access_ok(VERIFY_WRITE, __p, sizeof(*ptr)) ? \
		__put_user((x), ((__typeof__((ptr)) )__p)) : \
		-EFAULT; \
		})

		@@ -225,9 +226,10 @@ extern int __put_user_bad(void) __attribute__((noreturn));

		#define get_user(x, ptr) \
		({ \
		const void *__p = (ptr); \
		might_fault(); \
		access_ok(VERIFY_READ, ptr, sizeof(*ptr)) ? \
		__get_user(x, ptr) : \
		access_ok(VERIFY_READ, __p, sizeof(*ptr)) ? \
		__get_user((x), (__typeof__((ptr)) )__p) : \
		-EFAULT; \
		})

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