s390/bpf,jit: add support for XOR instruction

Add support for XOR instruction for use with X/K.

s390 JIT support for the new BPF_S_ALU_XOR_* instructions introduced
with 9e49e88 "filter: add XOR instruction for use with X/K".

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

arch/s390/net/bpf_jit_comp.c

@@ -389,10 +389,17 @@ static int bpf_jit_insn(struct bpf_jit *jit, struct sock_filter *filter,
 			EMIT4_DISP(0x5650d000, EMIT_CONST(K));
 		break;
 	case BPF_S_ANC_ALU_XOR_X: /* A ^= X; */
+	case BPF_S_ALU_XOR_X:
 		jit->seen |= SEEN_XREG;
 		/* xr %r5,%r12 */
 		EMIT2(0x175c);
 		break;
+	case BPF_S_ALU_XOR_K: /* A ^= K */
+		if (!K)
+			break;
+		/* x %r5,<d(K)>(%r13) */
+		EMIT4_DISP(0x5750d000, EMIT_CONST(K));
+		break;
 	case BPF_S_ALU_LSH_X: /* A <<= X; */
 		jit->seen |= SEEN_XREG;
 		/* sll %r5,0(%r12) */