From: Christian Borntraeger <borntraeger@xxxxxxxxxx> [ Upstream commit 062795fcdcb2d22822fb42644b1d76a8ad8439b3 ] Depending on inlining decisions by the compiler, __get/put_user_fn might become out of line. Then the compiler is no longer able to tell that size can only be 1,2,4 or 8 due to the check in __get/put_user resulting in false positives like ./arch/s390/include/asm/uaccess.h: In function ‘__put_user_fn’: ./arch/s390/include/asm/uaccess.h:113:9: warning: ‘rc’ may be used uninitialized in this function [-Wmaybe-uninitialized] 113 | return rc; | ^~ ./arch/s390/include/asm/uaccess.h: In function ‘__get_user_fn’: ./arch/s390/include/asm/uaccess.h:143:9: warning: ‘rc’ may be used uninitialized in this function [-Wmaybe-uninitialized] 143 | return rc; | ^~ These functions are supposed to be always inlined. Mark it as such. Signed-off-by: Christian Borntraeger <borntraeger@xxxxxxxxxx> Signed-off-by: Vasily Gorbik <gor@xxxxxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- 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 a7ef702201260..31b2913372b56 100644 --- a/arch/s390/include/asm/uaccess.h +++ b/arch/s390/include/asm/uaccess.h @@ -151,7 +151,7 @@ unsigned long __must_check __copy_to_user(void __user *to, const void *from, __rc; \ }) -static inline int __put_user_fn(void *x, void __user *ptr, unsigned long size) +static __always_inline int __put_user_fn(void *x, void __user *ptr, unsigned long size) { unsigned long spec = 0x810000UL; int rc; @@ -181,7 +181,7 @@ static inline int __put_user_fn(void *x, void __user *ptr, unsigned long size) return rc; } -static inline int __get_user_fn(void *x, const void __user *ptr, unsigned long size) +static __always_inline int __get_user_fn(void *x, const void __user *ptr, unsigned long size) { unsigned long spec = 0x81UL; int rc; -- 2.20.1