From ee64baf4ea3b7affb7e325bb3d188515ec4bb66e Mon Sep 17 00:00:00 2001 From: Heiko Carstens Date: Mon, 13 Jun 2016 10:17:20 +0200 Subject: [PATCH] s390/uaccess: use __builtin_expect for get_user/put_user We always expect that get_user and put_user return with zero. Give the compiler a hint so it can slightly optimize the code and avoid branches. This is the same what x86 got with commit a76cf66e948a ("x86/uaccess: Tell the compiler that uaccess is unlikely to fault"). Signed-off-by: Heiko Carstens Signed-off-by: Martin Schwidefsky --- arch/s390/include/asm/uaccess.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/s390/include/asm/uaccess.h b/arch/s390/include/asm/uaccess.h index e0900ddf91dd..2ea7f3208cd2 100644 --- a/arch/s390/include/asm/uaccess.h +++ b/arch/s390/include/asm/uaccess.h @@ -191,7 +191,7 @@ static inline int __get_user_fn(void *x, const void __user *ptr, unsigned long s __put_user_bad(); \ break; \ } \ - __pu_err; \ + __builtin_expect(__pu_err, 0); \ }) #define put_user(x, ptr) \ @@ -240,7 +240,7 @@ int __put_user_bad(void) __attribute__((noreturn)); __get_user_bad(); \ break; \ } \ - __gu_err; \ + __builtin_expect(__gu_err, 0); \ }) #define get_user(x, ptr) \ -- GitLab