From fce2a6bf0840c9d7c841beb4963d424e6e599c13 Mon Sep 17 00:00:00 2001 From: Yoshinori Sato Date: Thu, 16 Jul 2015 13:56:06 +0900 Subject: [PATCH] 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 --- include/asm-generic/uaccess.h | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) diff --git a/include/asm-generic/uaccess.h b/include/asm-generic/uaccess.h index 72d8803832ff..1bfa602958f2 100644 --- 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; \ }) -- 2.39.5