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Subject[PATCH 4.18 069/168] nds32: Fix get_user/put_user macro expand pointer problem
Date
4.18-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Zong Li <zong@andestech.com>

[ Upstream commit 6cce95a6c7d288ac2126eee4b95df448b9015b84 ]

The pointer argument of macro need to be taken out once first, and then
use the new pointer in the macro body.

In kernel/trace/trace.c, get_user(ch, ubuf++) causes the unexpected
increment after expand the macro.

Signed-off-by: Zong Li <zong@andestech.com>
Acked-by: Greentime Hu <greentime@andestech.com>
Signed-off-by: Greentime Hu <greentime@andestech.com>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
arch/nds32/include/asm/uaccess.h | 26 ++++++++++++++------------
1 file changed, 14 insertions(+), 12 deletions(-)

--- a/arch/nds32/include/asm/uaccess.h
+++ b/arch/nds32/include/asm/uaccess.h
@@ -78,8 +78,9 @@ static inline void set_fs(mm_segment_t f
#define get_user(x,p) \
({ \
long __e = -EFAULT; \
- if(likely(access_ok(VERIFY_READ, p, sizeof(*p)))) { \
- __e = __get_user(x,p); \
+ const __typeof__(*(p)) __user *__p = (p); \
+ if(likely(access_ok(VERIFY_READ, __p, sizeof(*__p)))) { \
+ __e = __get_user(x, __p); \
} else \
x = 0; \
__e; \
@@ -99,10 +100,10 @@ static inline void set_fs(mm_segment_t f

#define __get_user_err(x,ptr,err) \
do { \
- unsigned long __gu_addr = (unsigned long)(ptr); \
+ const __typeof__(*(ptr)) __user *__gu_addr = (ptr); \
unsigned long __gu_val; \
- __chk_user_ptr(ptr); \
- switch (sizeof(*(ptr))) { \
+ __chk_user_ptr(__gu_addr); \
+ switch (sizeof(*(__gu_addr))) { \
case 1: \
__get_user_asm("lbi",__gu_val,__gu_addr,err); \
break; \
@@ -119,7 +120,7 @@ do { \
BUILD_BUG(); \
break; \
} \
- (x) = (__typeof__(*(ptr)))__gu_val; \
+ (x) = (__typeof__(*(__gu_addr)))__gu_val; \
} while (0)

#define __get_user_asm(inst,x,addr,err) \
@@ -169,8 +170,9 @@ do { \
#define put_user(x,p) \
({ \
long __e = -EFAULT; \
- if(likely(access_ok(VERIFY_WRITE, p, sizeof(*p)))) { \
- __e = __put_user(x,p); \
+ __typeof__(*(p)) __user *__p = (p); \
+ if(likely(access_ok(VERIFY_WRITE, __p, sizeof(*__p)))) { \
+ __e = __put_user(x, __p); \
} \
__e; \
})
@@ -189,10 +191,10 @@ do { \

#define __put_user_err(x,ptr,err) \
do { \
- unsigned long __pu_addr = (unsigned long)(ptr); \
- __typeof__(*(ptr)) __pu_val = (x); \
- __chk_user_ptr(ptr); \
- switch (sizeof(*(ptr))) { \
+ __typeof__(*(ptr)) __user *__pu_addr = (ptr); \
+ __typeof__(*(__pu_addr)) __pu_val = (x); \
+ __chk_user_ptr(__pu_addr); \
+ switch (sizeof(*(__pu_addr))) { \
case 1: \
__put_user_asm("sbi",__pu_val,__pu_addr,err); \
break; \

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