From d78286bea3657a8761803b71a7d8b685007f750b Mon Sep 17 00:00:00 2001
From: Heiko Carstens <heiko.carstens@de.ibm.com>
Date: Wed, 2 Oct 2019 14:24:47 +0200
Subject: [PATCH] KVM: s390: fix __insn32_query() inline assembly

commit b1c41ac3ce569b04644bb1e3fd28926604637da3 upstream.

The inline assembly constraints of __insn32_query() tell the compiler
that only the first byte of "query" is being written to. Intended was
probably that 32 bytes are written to.

Fix and simplify the code and just use a "memory" clobber.

Fixes: d668139718a9 ("KVM: s390: provide query function for instructions returning 32 byte")
Cc: stable@vger.kernel.org # v5.2+
Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>

diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
index db64187e9505..681deaf9f20a 100644
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -327,7 +327,7 @@ static inline int plo_test_bit(unsigned char nr)
 	return cc == 0;
 }
 
-static inline void __insn32_query(unsigned int opcode, u8 query[32])
+static inline void __insn32_query(unsigned int opcode, u8 *query)
 {
 	register unsigned long r0 asm("0") = 0;	/* query function */
 	register unsigned long r1 asm("1") = (unsigned long) query;
@@ -335,9 +335,9 @@ static inline void __insn32_query(unsigned int opcode, u8 query[32])
 	asm volatile(
 		/* Parameter regs are ignored */
 		"	.insn	rrf,%[opc] << 16,2,4,6,0\n"
-		: "=m" (*query)
+		:
 		: "d" (r0), "a" (r1), [opc] "i" (opcode)
-		: "cc");
+		: "cc", "memory");
 }
 
 #define INSN_SORTL 0xb938
-- 
2.7.4