From: Yoshinori Sato <ysato@users.sourceforge.jp>
Date: Thu, 16 Jul 2015 04:56:06 +0000 (+0900)
Subject: asm-generic: {get,put}_user ptr argument evaluate only 1 time
X-Git-Tag: KARO-TX6UL-2015-11-03~131^2~1
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=fce2a6bf0840c9d7c841beb4963d424e6e599c13;p=karo-tx-linux.git

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 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;					\
 })