Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 4db25cc9 authored by Daniel Borkmann's avatar Daniel Borkmann Committed by Alexei Starovoitov
Browse files

bpf, mips64: remove ld_abs/ld_ind 



Since LD_ABS/LD_IND instructions are now removed from the core and
reimplemented through a combination of inlined BPF instructions and
a slow-path helper, we can get rid of the complexity from mips64 JIT.

Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
Acked-by: default avatarAlexei Starovoitov <ast@kernel.org>
Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
parent 0d2d0ced

arch/mips/net/ebpf_jit.c

+0 −104
Original line number Diff line number Diff line
@@ -1267,110 +1267,6 @@ static int build_one_insn(const struct bpf_insn *insn, struct jit_ctx *ctx, 
			return -EINVAL;

		break;



	case BPF_LD | BPF_B | BPF_ABS:

	case BPF_LD | BPF_H | BPF_ABS:

	case BPF_LD | BPF_W | BPF_ABS:

	case BPF_LD | BPF_DW | BPF_ABS:

		ctx->flags |= EBPF_SAVE_RA;



		gen_imm_to_reg(insn, MIPS_R_A1, ctx);

		emit_instr(ctx, addiu, MIPS_R_A2, MIPS_R_ZERO, size_to_len(insn));



		if (insn->imm < 0) {

			emit_const_to_reg(ctx, MIPS_R_T9, (u64)bpf_internal_load_pointer_neg_helper);

		} else {

			emit_const_to_reg(ctx, MIPS_R_T9, (u64)ool_skb_header_pointer);

			emit_instr(ctx, daddiu, MIPS_R_A3, MIPS_R_SP, ctx->tmp_offset);

		}

		goto ld_skb_common;



	case BPF_LD | BPF_B | BPF_IND:

	case BPF_LD | BPF_H | BPF_IND:

	case BPF_LD | BPF_W | BPF_IND:

	case BPF_LD | BPF_DW | BPF_IND:

		ctx->flags |= EBPF_SAVE_RA;

		src = ebpf_to_mips_reg(ctx, insn, src_reg_no_fp);

		if (src < 0)

			return src;

		ts = get_reg_val_type(ctx, this_idx, insn->src_reg);

		if (ts == REG_32BIT_ZERO_EX) {

			/* sign extend */

			emit_instr(ctx, sll, MIPS_R_A1, src, 0);

			src = MIPS_R_A1;

		}

		if (insn->imm >= S16_MIN && insn->imm <= S16_MAX) {

			emit_instr(ctx, daddiu, MIPS_R_A1, src, insn->imm);

		} else {

			gen_imm_to_reg(insn, MIPS_R_AT, ctx);

			emit_instr(ctx, daddu, MIPS_R_A1, MIPS_R_AT, src);

		}

		/* truncate to 32-bit int */

		emit_instr(ctx, sll, MIPS_R_A1, MIPS_R_A1, 0);

		emit_instr(ctx, daddiu, MIPS_R_A3, MIPS_R_SP, ctx->tmp_offset);

		emit_instr(ctx, slt, MIPS_R_AT, MIPS_R_A1, MIPS_R_ZERO);



		emit_const_to_reg(ctx, MIPS_R_T8, (u64)bpf_internal_load_pointer_neg_helper);

		emit_const_to_reg(ctx, MIPS_R_T9, (u64)ool_skb_header_pointer);

		emit_instr(ctx, addiu, MIPS_R_A2, MIPS_R_ZERO, size_to_len(insn));

		emit_instr(ctx, movn, MIPS_R_T9, MIPS_R_T8, MIPS_R_AT);



ld_skb_common:

		emit_instr(ctx, jalr, MIPS_R_RA, MIPS_R_T9);

		/* delay slot move */

		emit_instr(ctx, daddu, MIPS_R_A0, MIPS_R_S0, MIPS_R_ZERO);



		/* Check the error value */

		b_off = b_imm(exit_idx, ctx);

		if (is_bad_offset(b_off)) {

			target = j_target(ctx, exit_idx);

			if (target == (unsigned int)-1)

				return -E2BIG;



			if (!(ctx->offsets[this_idx] & OFFSETS_B_CONV)) {

				ctx->offsets[this_idx] |= OFFSETS_B_CONV;

				ctx->long_b_conversion = 1;

			}

			emit_instr(ctx, bne, MIPS_R_V0, MIPS_R_ZERO, 4 * 3);

			emit_instr(ctx, nop);

			emit_instr(ctx, j, target);

			emit_instr(ctx, nop);

		} else {

			emit_instr(ctx, beq, MIPS_R_V0, MIPS_R_ZERO, b_off);

			emit_instr(ctx, nop);

		}



#ifdef __BIG_ENDIAN

		need_swap = false;

#else

		need_swap = true;

#endif

		dst = MIPS_R_V0;

		switch (BPF_SIZE(insn->code)) {

		case BPF_B:

			emit_instr(ctx, lbu, dst, 0, MIPS_R_V0);

			break;

		case BPF_H:

			emit_instr(ctx, lhu, dst, 0, MIPS_R_V0);

			if (need_swap)

				emit_instr(ctx, wsbh, dst, dst);

			break;

		case BPF_W:

			emit_instr(ctx, lw, dst, 0, MIPS_R_V0);

			if (need_swap) {

				emit_instr(ctx, wsbh, dst, dst);

				emit_instr(ctx, rotr, dst, dst, 16);

			}

			break;

		case BPF_DW:

			emit_instr(ctx, ld, dst, 0, MIPS_R_V0);

			if (need_swap) {

				emit_instr(ctx, dsbh, dst, dst);

				emit_instr(ctx, dshd, dst, dst);

			}

			break;

		}



		break;

	case BPF_ALU | BPF_END | BPF_FROM_BE:

	case BPF_ALU | BPF_END | BPF_FROM_LE:

		dst = ebpf_to_mips_reg(ctx, insn, dst_reg);