[PATCH 1/6] x86/uaccess: Dont evaluate argument inside AC region

Peter Zijlstra
2019-02-25T12:53:26Z

AC regions are special, make sure we don't do possibly complex
evaluations there.

Probably-Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
---
arch/x86/include/asm/uaccess.h | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

--- a/arch/x86/include/asm/uaccess.h
+++ b/arch/x86/include/asm/uaccess.h
@@ -431,8 +431,10 @@ do { \
({ \
__label__ __pu_label; \
int __pu_err = -EFAULT; \
+ __typeof__(*(ptr)) __pu_val; \
+ __pu_val = x; \
__uaccess_begin(); \
- __put_user_size((x), (ptr), (size), __pu_label); \
+ __put_user_size(__pu_val, (ptr), (size), __pu_label); \
__pu_err = 0; \
__pu_label: \
__uaccess_end(); \