ARM: net: bpf_jit_32: add XOR instruction for BPF JIT

This patch is a follow-up for patch "filter: add XOR instruction for use
with X/K" that implements BPF ARM JIT parts for the BPF XOR operation.

Signed-off-by: Daniel Borkmann <daniel.borkmann@tik.ee.ethz.ch>
Cc: Mircea Gherzan <mgherzan@gmail.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Acked-by: Mircea Gherzan <mgherzan@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

arch/arm/net/bpf_jit_32.c

@@ -646,6 +646,16 @@ static int build_body(struct jit_ctx *ctx)
 			update_on_xread(ctx);
 			emit(ARM_ORR_R(r_A, r_A, r_X), ctx);
 			break;
+		case BPF_S_ALU_XOR_K:
+			/* A ^= K; */
+			OP_IMM3(ARM_EOR, r_A, r_A, k, ctx);
+			break;
+		case BPF_S_ANC_ALU_XOR_X:
+		case BPF_S_ALU_XOR_X:
+			/* A ^= X */
+			update_on_xread(ctx);
+			emit(ARM_EOR_R(r_A, r_A, r_X), ctx);
+			break;
 		case BPF_S_ALU_AND_K:
 			/* A &= K */
 			OP_IMM3(ARM_AND, r_A, r_A, k, ctx);
@@ -762,11 +772,6 @@ static int build_body(struct jit_ctx *ctx)
 			update_on_xread(ctx);
 			emit(ARM_MOV_R(r_A, r_X), ctx);
 			break;
-		case BPF_S_ANC_ALU_XOR_X:
-			/* A ^= X */
-			update_on_xread(ctx);
-			emit(ARM_EOR_R(r_A, r_A, r_X), ctx);
-			break;
 		case BPF_S_ANC_PROTOCOL:
 			/* A = ntohs(skb->protocol) */
 			ctx->seen |= SEEN_SKB;

arch/arm/net/bpf_jit_32.h

@@ -69,6 +69,7 @@
 #define ARM_INST_CMP_I		0x03500000
 
 #define ARM_INST_EOR_R		0x00200000
+#define ARM_INST_EOR_I		0x02200000
 
 #define ARM_INST_LDRB_I		0x05d00000
 #define ARM_INST_LDRB_R		0x07d00000
@@ -135,6 +136,7 @@
 #define ARM_CMP_I(rn, imm)	_AL3_I(ARM_INST_CMP, 0, rn, imm)
 
 #define ARM_EOR_R(rd, rn, rm)	_AL3_R(ARM_INST_EOR, rd, rn, rm)
+#define ARM_EOR_I(rd, rn, imm)	_AL3_I(ARM_INST_EOR, rd, rn, imm)
 
 #define ARM_LDR_I(rt, rn, off)	(ARM_INST_LDR_I | (rt) << 12 | (rn) << 16 \
 				 | (off))