asm-generic: {get,put}_user ptr argument evaluate only 1 time

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>

diff --git a/include/asm-generic/uaccess.h b/include/asm-generic/uaccess.h
index 72d8803..1bfa602 100644 (file)
--- a/include/asm-generic/uaccess.h
+++ b/include/asm-generic/uaccess.h
@@ -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;                                        \
 })