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

commit 89aba4c upstream.

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: 6c2a9e6 ("[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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

arch/s390/lib/uaccess.c

@@ -339,7 +339,7 @@ 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(3b,5b)
-		: "+a" (size), "+a" (to), "+a" (tmp1), "=a" (tmp2)
+		: "+&a" (size), "+&a" (to), "+a" (tmp1), "=&a" (tmp2)
 		: "a" (empty_zero_page), "d" (reg0) : "cc", "memory");
 	return size;
 }