bpf, arm64: implement jiting of BPF_J{LT, LE, SLT, SLE}

This work implements jiting of BPF_J{LT,LE,SLT,SLE} instructions
with BPF_X/BPF_K variants for the arm64 eBPF JIT.

Signed-off-by: Daniel Borkmann <[e-mail]>
Signed-off-by: David S. Miller <[e-mail]>

arch/arm64/net/bpf_jit.h

···
 #define A64_COND_NE	AARCH64_INSN_COND_NE /* != */
 #define A64_COND_CS	AARCH64_INSN_COND_CS /* unsigned >= */
 #define A64_COND_HI	AARCH64_INSN_COND_HI /* unsigned > */
+#define A64_COND_LS	AARCH64_INSN_COND_LS /* unsigned <= */
+#define A64_COND_CC	AARCH64_INSN_COND_CC /* unsigned < */
 #define A64_COND_GE	AARCH64_INSN_COND_GE /* signed >= */
 #define A64_COND_GT	AARCH64_INSN_COND_GT /* signed > */
+#define A64_COND_LE	AARCH64_INSN_COND_LE /* signed <= */
+#define A64_COND_LT	AARCH64_INSN_COND_LT /* signed < */
 #define A64_B_(cond, imm19) A64_COND_BRANCH(cond, (imm19) << 2)
 
 /* Unconditional branch (immediate) */

arch/arm64/net/bpf_jit_comp.c

···
 	/* IF (dst COND src) JUMP off */
 	case BPF_JMP | BPF_JEQ | BPF_X:
 	case BPF_JMP | BPF_JGT | BPF_X:
+	case BPF_JMP | BPF_JLT | BPF_X:
 	case BPF_JMP | BPF_JGE | BPF_X:
+	case BPF_JMP | BPF_JLE | BPF_X:
 	case BPF_JMP | BPF_JNE | BPF_X:
 	case BPF_JMP | BPF_JSGT | BPF_X:
+	case BPF_JMP | BPF_JSLT | BPF_X:
 	case BPF_JMP | BPF_JSGE | BPF_X:
+	case BPF_JMP | BPF_JSLE | BPF_X:
 		emit(A64_CMP(1, dst, src), ctx);
 emit_cond_jmp:
 		jmp_offset = bpf2a64_offset(i + off, i, ctx);
···
 		case BPF_JGT:
 			jmp_cond = A64_COND_HI;
 			break;
+		case BPF_JLT:
+			jmp_cond = A64_COND_CC;
+			break;
 		case BPF_JGE:
 			jmp_cond = A64_COND_CS;
+			break;
+		case BPF_JLE:
+			jmp_cond = A64_COND_LS;
 			break;
 		case BPF_JSET:
 		case BPF_JNE:
···
 		case BPF_JSGT:
 			jmp_cond = A64_COND_GT;
 			break;
+		case BPF_JSLT:
+			jmp_cond = A64_COND_LT;
+			break;
 		case BPF_JSGE:
 			jmp_cond = A64_COND_GE;
+			break;
+		case BPF_JSLE:
+			jmp_cond = A64_COND_LE;
 			break;
 		default:
 			return -EFAULT;
···
 	/* IF (dst COND imm) JUMP off */
 	case BPF_JMP | BPF_JEQ | BPF_K:
 	case BPF_JMP | BPF_JGT | BPF_K:
+	case BPF_JMP | BPF_JLT | BPF_K:
 	case BPF_JMP | BPF_JGE | BPF_K:
+	case BPF_JMP | BPF_JLE | BPF_K:
 	case BPF_JMP | BPF_JNE | BPF_K:
 	case BPF_JMP | BPF_JSGT | BPF_K:
+	case BPF_JMP | BPF_JSLT | BPF_K:
 	case BPF_JMP | BPF_JSGE | BPF_K:
+	case BPF_JMP | BPF_JSLE | BPF_K:
 		emit_a64_mov_i(1, tmp, imm, ctx);
 		emit(A64_CMP(1, dst, tmp), ctx);
 		goto emit_cond_jmp;