From a4c927733e74bb39f9964d8f451e717f8cf6d6cf Mon Sep 17 00:00:00 2001 From: Jiong Wang Date: Fri, 24 May 2019 23:25:23 +0100 Subject: [PATCH] powerpc: bpf: eliminate zero extension code-gen Cc: Naveen N. Rao Cc: Sandipan Das Signed-off-by: Jiong Wang Signed-off-by: Alexei Starovoitov --- arch/powerpc/net/bpf_jit_comp64.c | 36 +++++++++++++++++++++++++++++++++--- 1 file changed, 33 insertions(+), 3 deletions(-) diff --git a/arch/powerpc/net/bpf_jit_comp64.c b/arch/powerpc/net/bpf_jit_comp64.c index 21a1dcd..0ebd946 100644 --- a/arch/powerpc/net/bpf_jit_comp64.c +++ b/arch/powerpc/net/bpf_jit_comp64.c @@ -504,6 +504,9 @@ static int bpf_jit_build_body(struct bpf_prog *fp, u32 *image, case BPF_ALU | BPF_LSH | BPF_X: /* (u32) dst <<= (u32) src */ /* slw clears top 32 bits */ PPC_SLW(dst_reg, dst_reg, src_reg); + /* skip zero extension move, but set address map. */ + if (insn_is_zext(&insn[i + 1])) + addrs[++i] = ctx->idx * 4; break; case BPF_ALU64 | BPF_LSH | BPF_X: /* dst <<= src; */ PPC_SLD(dst_reg, dst_reg, src_reg); @@ -511,6 +514,8 @@ static int bpf_jit_build_body(struct bpf_prog *fp, u32 *image, case BPF_ALU | BPF_LSH | BPF_K: /* (u32) dst <<== (u32) imm */ /* with imm 0, we still need to clear top 32 bits */ PPC_SLWI(dst_reg, dst_reg, imm); + if (insn_is_zext(&insn[i + 1])) + addrs[++i] = ctx->idx * 4; break; case BPF_ALU64 | BPF_LSH | BPF_K: /* dst <<== imm */ if (imm != 0) @@ -518,12 +523,16 @@ static int bpf_jit_build_body(struct bpf_prog *fp, u32 *image, break; case BPF_ALU | BPF_RSH | BPF_X: /* (u32) dst >>= (u32) src */ PPC_SRW(dst_reg, dst_reg, src_reg); + if (insn_is_zext(&insn[i + 1])) + addrs[++i] = ctx->idx * 4; break; case BPF_ALU64 | BPF_RSH | BPF_X: /* dst >>= src */ PPC_SRD(dst_reg, dst_reg, src_reg); break; case BPF_ALU | BPF_RSH | BPF_K: /* (u32) dst >>= (u32) imm */ PPC_SRWI(dst_reg, dst_reg, imm); + if (insn_is_zext(&insn[i + 1])) + addrs[++i] = ctx->idx * 4; break; case BPF_ALU64 | BPF_RSH | BPF_K: /* dst >>= imm */ if (imm != 0) @@ -548,6 +557,11 @@ static int bpf_jit_build_body(struct bpf_prog *fp, u32 *image, */ case BPF_ALU | BPF_MOV | BPF_X: /* (u32) dst = src */ case BPF_ALU64 | BPF_MOV | BPF_X: /* dst = src */ + if (imm == 1) { + /* special mov32 for zext */ + PPC_RLWINM(dst_reg, dst_reg, 0, 0, 31); + break; + } PPC_MR(dst_reg, src_reg); goto bpf_alu32_trunc; case BPF_ALU | BPF_MOV | BPF_K: /* (u32) dst = imm */ @@ -555,11 +569,13 @@ static int bpf_jit_build_body(struct bpf_prog *fp, u32 *image, PPC_LI32(dst_reg, imm); if (imm < 0) goto bpf_alu32_trunc; + else if (insn_is_zext(&insn[i + 1])) + addrs[++i] = ctx->idx * 4; break; bpf_alu32_trunc: /* Truncate to 32-bits */ - if (BPF_CLASS(code) == BPF_ALU) + if (BPF_CLASS(code) == BPF_ALU && !fp->aux->verifier_zext) PPC_RLWINM(dst_reg, dst_reg, 0, 0, 31); break; @@ -618,10 +634,13 @@ emit_clear: case 16: /* zero-extend 16 bits into 64 bits */ PPC_RLDICL(dst_reg, dst_reg, 0, 48); + if (insn_is_zext(&insn[i + 1])) + addrs[++i] = ctx->idx * 4; break; case 32: - /* zero-extend 32 bits into 64 bits */ - PPC_RLDICL(dst_reg, dst_reg, 0, 32); + if (!fp->aux->verifier_zext) + /* zero-extend 32 bits into 64 bits */ + PPC_RLDICL(dst_reg, dst_reg, 0, 32); break; case 64: /* nop */ @@ -698,14 +717,20 @@ emit_clear: /* dst = *(u8 *)(ul) (src + off) */ case BPF_LDX | BPF_MEM | BPF_B: PPC_LBZ(dst_reg, src_reg, off); + if (insn_is_zext(&insn[i + 1])) + addrs[++i] = ctx->idx * 4; break; /* dst = *(u16 *)(ul) (src + off) */ case BPF_LDX | BPF_MEM | BPF_H: PPC_LHZ(dst_reg, src_reg, off); + if (insn_is_zext(&insn[i + 1])) + addrs[++i] = ctx->idx * 4; break; /* dst = *(u32 *)(ul) (src + off) */ case BPF_LDX | BPF_MEM | BPF_W: PPC_LWZ(dst_reg, src_reg, off); + if (insn_is_zext(&insn[i + 1])) + addrs[++i] = ctx->idx * 4; break; /* dst = *(u64 *)(ul) (src + off) */ case BPF_LDX | BPF_MEM | BPF_DW: @@ -1046,6 +1071,11 @@ struct powerpc64_jit_data { struct codegen_context ctx; }; +bool bpf_jit_needs_zext(void) +{ + return true; +} + struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *fp) { u32 proglen; -- 2.7.4