From: Heiko Carstens <hca@linux.ibm.com>

Date: Thu, 23 Mar 2023 13:09:16 +0100

Subject: s390/uaccess: add missing earlyclobber annotations to __clear_user()

Git-commit: 89aba4c26fae4e459f755a18912845c348ee48f3

Patch-mainline: v6.3-rc5

References: bsc#1209856 git-fixes

Add missing earlyclobber annotation to size, to, and tmp2 operands of the

__clear_user() inline assembly since they are modified or written to before

the last usage of all input operands. This can lead to incorrect register

allocation for the inline assembly.

Fixes: 6c2a9e6df604 ("[S390] Use alternative user-copy operations for new hardware.")

Reported-by: Mark Rutland <mark.rutland@arm.com>

Link: https://lore.kernel.org/all/20230321122514.1743889-3-mark.rutland@arm.com/

Cc: stable@vger.kernel.org

Reviewed-by: Gerald Schaefer <gerald.schaefer@linux.ibm.com>

Signed-off-by: Heiko Carstens <hca@linux.ibm.com>

Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>

Acked-by: Miroslav Franc <mfranc@suse.cz>

---

 arch/s390/lib/uaccess.c | 2 +-

 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/s390/lib/uaccess.c b/arch/s390/lib/uaccess.c

index 9e306eb38170..a00e793ea2e7 100644

--- a/arch/s390/lib/uaccess.c

+++ b/arch/s390/lib/uaccess.c

@@ -292,7 +292,7 @@ static inline unsigned long clear_user_mvcos(void __user *to, unsigned long size

 		"4: slgr  %0,%0\n"

 		"5:\n"

 		EX_TABLE(0b,2b) EX_TABLE(6b,2b) EX_TABLE(3b,5b) EX_TABLE(7b,5b)

-		: "+a" (size), "+a" (to), "+a" (tmp1), "=a" (tmp2)

+		: "+&a" (size), "+&a" (to), "+a" (tmp1), "=&a" (tmp2)

 		: "a" (empty_zero_page), [spec] "K" (0x81UL)

 		: "cc", "memory", "0");

 	return size;