From 66d0d5a854a6625974e7de4b874e7934988b0ef8 Mon Sep 17 00:00:00 2001 From: Jiong Wang Date: Fri, 24 May 2019 23:25:27 +0100 Subject: [PATCH] riscv: bpf: eliminate zero extension code-gen MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Cc: Björn Töpel Acked-by: Björn Töpel Tested-by: Björn Töpel Signed-off-by: Jiong Wang Signed-off-by: Alexei Starovoitov --- arch/riscv/net/bpf_jit_comp.c | 43 ++++++++++++++++++++++++----------- 1 file changed, 30 insertions(+), 13 deletions(-) diff --git a/arch/riscv/net/bpf_jit_comp.c b/arch/riscv/net/bpf_jit_comp.c index 80b12aa5e10d..c4c836e3d318 100644 --- a/arch/riscv/net/bpf_jit_comp.c +++ b/arch/riscv/net/bpf_jit_comp.c @@ -731,6 +731,7 @@ static int emit_insn(const struct bpf_insn *insn, struct rv_jit_context *ctx, { bool is64 = BPF_CLASS(insn->code) == BPF_ALU64 || BPF_CLASS(insn->code) == BPF_JMP; + struct bpf_prog_aux *aux = ctx->prog->aux; int rvoff, i = insn - ctx->prog->insnsi; u8 rd = -1, rs = -1, code = insn->code; s16 off = insn->off; @@ -742,8 +743,13 @@ static int emit_insn(const struct bpf_insn *insn, struct rv_jit_context *ctx, /* dst = src */ case BPF_ALU | BPF_MOV | BPF_X: case BPF_ALU64 | BPF_MOV | BPF_X: + if (imm == 1) { + /* Special mov32 for zext */ + emit_zext_32(rd, ctx); + break; + } emit(is64 ? rv_addi(rd, rs, 0) : rv_addiw(rd, rs, 0), ctx); - if (!is64) + if (!is64 && !aux->verifier_zext) emit_zext_32(rd, ctx); break; @@ -771,19 +777,19 @@ static int emit_insn(const struct bpf_insn *insn, struct rv_jit_context *ctx, case BPF_ALU | BPF_MUL | BPF_X: case BPF_ALU64 | BPF_MUL | BPF_X: emit(is64 ? rv_mul(rd, rd, rs) : rv_mulw(rd, rd, rs), ctx); - if (!is64) + if (!is64 && !aux->verifier_zext) emit_zext_32(rd, ctx); break; case BPF_ALU | BPF_DIV | BPF_X: case BPF_ALU64 | BPF_DIV | BPF_X: emit(is64 ? rv_divu(rd, rd, rs) : rv_divuw(rd, rd, rs), ctx); - if (!is64) + if (!is64 && !aux->verifier_zext) emit_zext_32(rd, ctx); break; case BPF_ALU | BPF_MOD | BPF_X: case BPF_ALU64 | BPF_MOD | BPF_X: emit(is64 ? rv_remu(rd, rd, rs) : rv_remuw(rd, rd, rs), ctx); - if (!is64) + if (!is64 && !aux->verifier_zext) emit_zext_32(rd, ctx); break; case BPF_ALU | BPF_LSH | BPF_X: @@ -867,7 +873,7 @@ out_be: case BPF_ALU | BPF_MOV | BPF_K: case BPF_ALU64 | BPF_MOV | BPF_K: emit_imm(rd, imm, ctx); - if (!is64) + if (!is64 && !aux->verifier_zext) emit_zext_32(rd, ctx); break; @@ -882,7 +888,7 @@ out_be: emit(is64 ? rv_add(rd, rd, RV_REG_T1) : rv_addw(rd, rd, RV_REG_T1), ctx); } - if (!is64) + if (!is64 && !aux->verifier_zext) emit_zext_32(rd, ctx); break; case BPF_ALU | BPF_SUB | BPF_K: @@ -895,7 +901,7 @@ out_be: emit(is64 ? rv_sub(rd, rd, RV_REG_T1) : rv_subw(rd, rd, RV_REG_T1), ctx); } - if (!is64) + if (!is64 && !aux->verifier_zext) emit_zext_32(rd, ctx); break; case BPF_ALU | BPF_AND | BPF_K: @@ -906,7 +912,7 @@ out_be: emit_imm(RV_REG_T1, imm, ctx); emit(rv_and(rd, rd, RV_REG_T1), ctx); } - if (!is64) + if (!is64 && !aux->verifier_zext) emit_zext_32(rd, ctx); break; case BPF_ALU | BPF_OR | BPF_K: @@ -917,7 +923,7 @@ out_be: emit_imm(RV_REG_T1, imm, ctx); emit(rv_or(rd, rd, RV_REG_T1), ctx); } - if (!is64) + if (!is64 && !aux->verifier_zext) emit_zext_32(rd, ctx); break; case BPF_ALU | BPF_XOR | BPF_K: @@ -928,7 +934,7 @@ out_be: emit_imm(RV_REG_T1, imm, ctx); emit(rv_xor(rd, rd, RV_REG_T1), ctx); } - if (!is64) + if (!is64 && !aux->verifier_zext) emit_zext_32(rd, ctx); break; case BPF_ALU | BPF_MUL | BPF_K: @@ -936,7 +942,7 @@ out_be: emit_imm(RV_REG_T1, imm, ctx); emit(is64 ? rv_mul(rd, rd, RV_REG_T1) : rv_mulw(rd, rd, RV_REG_T1), ctx); - if (!is64) + if (!is64 && !aux->verifier_zext) emit_zext_32(rd, ctx); break; case BPF_ALU | BPF_DIV | BPF_K: @@ -944,7 +950,7 @@ out_be: emit_imm(RV_REG_T1, imm, ctx); emit(is64 ? rv_divu(rd, rd, RV_REG_T1) : rv_divuw(rd, rd, RV_REG_T1), ctx); - if (!is64) + if (!is64 && !aux->verifier_zext) emit_zext_32(rd, ctx); break; case BPF_ALU | BPF_MOD | BPF_K: @@ -952,7 +958,7 @@ out_be: emit_imm(RV_REG_T1, imm, ctx); emit(is64 ? rv_remu(rd, rd, RV_REG_T1) : rv_remuw(rd, rd, RV_REG_T1), ctx); - if (!is64) + if (!is64 && !aux->verifier_zext) emit_zext_32(rd, ctx); break; case BPF_ALU | BPF_LSH | BPF_K: @@ -1239,6 +1245,8 @@ out_be: emit_imm(RV_REG_T1, off, ctx); emit(rv_add(RV_REG_T1, RV_REG_T1, rs), ctx); emit(rv_lbu(rd, 0, RV_REG_T1), ctx); + if (insn_is_zext(&insn[1])) + return 1; break; case BPF_LDX | BPF_MEM | BPF_H: if (is_12b_int(off)) { @@ -1249,6 +1257,8 @@ out_be: emit_imm(RV_REG_T1, off, ctx); emit(rv_add(RV_REG_T1, RV_REG_T1, rs), ctx); emit(rv_lhu(rd, 0, RV_REG_T1), ctx); + if (insn_is_zext(&insn[1])) + return 1; break; case BPF_LDX | BPF_MEM | BPF_W: if (is_12b_int(off)) { @@ -1259,6 +1269,8 @@ out_be: emit_imm(RV_REG_T1, off, ctx); emit(rv_add(RV_REG_T1, RV_REG_T1, rs), ctx); emit(rv_lwu(rd, 0, RV_REG_T1), ctx); + if (insn_is_zext(&insn[1])) + return 1; break; case BPF_LDX | BPF_MEM | BPF_DW: if (is_12b_int(off)) { @@ -1503,6 +1515,11 @@ static void bpf_flush_icache(void *start, void *end) flush_icache_range((unsigned long)start, (unsigned long)end); } +bool bpf_jit_needs_zext(void) +{ + return true; +} + struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog) { bool tmp_blinded = false, extra_pass = false; -- 2.30.2