KVM: s390: fix __insn32_query() inline assembly

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>

diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
index f6db0f1..74e1a22 100644 (file)
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -332,7 +332,7 @@ 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;
@@ -340,9 +340,9 @@ 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