From: Vasily Gorbik <gor@linux.ibm.com>
Date: Mon, 2 Mar 2026 18:03:34 +0000 (+0100)
Subject: s390/xor: Fix xor_xc_5() inline assembly
X-Git-Tag: v7.0-rc3~17^2~3
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=5f25805303e201f3afaff0a90f7c7ce257468704;p=thirdparty%2Fkernel%2Flinux.git

s390/xor: Fix xor_xc_5() inline assembly

xor_xc_5() contains a larl 1,2f that is not used by the asm and is not
declared as a clobber. This can corrupt a compiler-allocated value in %r1
and lead to miscompilation. Remove the instruction.

Fixes: 745600ed6965 ("s390/lib: Use exrl instead of ex in xor functions")
Cc: stable@vger.kernel.org
Reviewed-by: Juergen Christ <jchrist@linux.ibm.com>
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Reviewed-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
---

diff --git a/arch/s390/lib/xor.c b/arch/s390/lib/xor.c
index 1721b73b78036..a4d8b51beb95f 100644
--- a/arch/s390/lib/xor.c
+++ b/arch/s390/lib/xor.c
@@ -96,7 +96,6 @@ static void xor_xc_5(unsigned long bytes, unsigned long * __restrict p1,
 		     const unsigned long * __restrict p5)
 {
 	asm volatile(
-		"	larl	1,2f\n"
 		"	aghi	%0,-1\n"
 		"	jm	6f\n"
 		"	srlg	0,%0,8\n"