From 591006b9e754ca723e3deabeccdf56eb531f0b94 Mon Sep 17 00:00:00 2001 From: Jiong Wang Date: Fri, 24 May 2019 23:25:24 +0100 Subject: [PATCH] s390: bpf: eliminate zero extension code-gen Cc: Martin Schwidefsky Cc: Heiko Carstens Signed-off-by: Jiong Wang Signed-off-by: Alexei Starovoitov --- arch/s390/net/bpf_jit_comp.c | 41 ++++++++++++++++++++++++++++++------ 1 file changed, 34 insertions(+), 7 deletions(-) diff --git a/arch/s390/net/bpf_jit_comp.c b/arch/s390/net/bpf_jit_comp.c index 5e7c63033159..e636728ab452 100644 --- a/arch/s390/net/bpf_jit_comp.c +++ b/arch/s390/net/bpf_jit_comp.c @@ -299,9 +299,11 @@ static inline void reg_set_seen(struct bpf_jit *jit, u32 b1) #define EMIT_ZERO(b1) \ ({ \ - /* llgfr %dst,%dst (zero extend to 64 bit) */ \ - EMIT4(0xb9160000, b1, b1); \ - REG_SET_SEEN(b1); \ + if (!fp->aux->verifier_zext) { \ + /* llgfr %dst,%dst (zero extend to 64 bit) */ \ + EMIT4(0xb9160000, b1, b1); \ + REG_SET_SEEN(b1); \ + } \ }) /* @@ -520,6 +522,8 @@ static noinline int bpf_jit_insn(struct bpf_jit *jit, struct bpf_prog *fp, int i case BPF_ALU | BPF_MOV | BPF_X: /* dst = (u32) src */ /* llgfr %dst,%src */ EMIT4(0xb9160000, dst_reg, src_reg); + if (insn_is_zext(&insn[1])) + insn_count = 2; break; case BPF_ALU64 | BPF_MOV | BPF_X: /* dst = src */ /* lgr %dst,%src */ @@ -528,6 +532,8 @@ static noinline int bpf_jit_insn(struct bpf_jit *jit, struct bpf_prog *fp, int i case BPF_ALU | BPF_MOV | BPF_K: /* dst = (u32) imm */ /* llilf %dst,imm */ EMIT6_IMM(0xc00f0000, dst_reg, imm); + if (insn_is_zext(&insn[1])) + insn_count = 2; break; case BPF_ALU64 | BPF_MOV | BPF_K: /* dst = imm */ /* lgfi %dst,imm */ @@ -639,6 +645,8 @@ static noinline int bpf_jit_insn(struct bpf_jit *jit, struct bpf_prog *fp, int i EMIT4(0xb9970000, REG_W0, src_reg); /* llgfr %dst,%rc */ EMIT4(0xb9160000, dst_reg, rc_reg); + if (insn_is_zext(&insn[1])) + insn_count = 2; break; } case BPF_ALU64 | BPF_DIV | BPF_X: /* dst = dst / src */ @@ -676,6 +684,8 @@ static noinline int bpf_jit_insn(struct bpf_jit *jit, struct bpf_prog *fp, int i EMIT_CONST_U32(imm)); /* llgfr %dst,%rc */ EMIT4(0xb9160000, dst_reg, rc_reg); + if (insn_is_zext(&insn[1])) + insn_count = 2; break; } case BPF_ALU64 | BPF_DIV | BPF_K: /* dst = dst / imm */ @@ -864,10 +874,13 @@ static noinline int bpf_jit_insn(struct bpf_jit *jit, struct bpf_prog *fp, int i case 16: /* dst = (u16) cpu_to_be16(dst) */ /* llghr %dst,%dst */ EMIT4(0xb9850000, dst_reg, dst_reg); + if (insn_is_zext(&insn[1])) + insn_count = 2; break; case 32: /* dst = (u32) cpu_to_be32(dst) */ - /* llgfr %dst,%dst */ - EMIT4(0xb9160000, dst_reg, dst_reg); + if (!fp->aux->verifier_zext) + /* llgfr %dst,%dst */ + EMIT4(0xb9160000, dst_reg, dst_reg); break; case 64: /* dst = (u64) cpu_to_be64(dst) */ break; @@ -882,12 +895,15 @@ static noinline int bpf_jit_insn(struct bpf_jit *jit, struct bpf_prog *fp, int i EMIT4_DISP(0x88000000, dst_reg, REG_0, 16); /* llghr %dst,%dst */ EMIT4(0xb9850000, dst_reg, dst_reg); + if (insn_is_zext(&insn[1])) + insn_count = 2; break; case 32: /* dst = (u32) cpu_to_le32(dst) */ /* lrvr %dst,%dst */ EMIT4(0xb91f0000, dst_reg, dst_reg); - /* llgfr %dst,%dst */ - EMIT4(0xb9160000, dst_reg, dst_reg); + if (!fp->aux->verifier_zext) + /* llgfr %dst,%dst */ + EMIT4(0xb9160000, dst_reg, dst_reg); break; case 64: /* dst = (u64) cpu_to_le64(dst) */ /* lrvgr %dst,%dst */ @@ -968,16 +984,22 @@ static noinline int bpf_jit_insn(struct bpf_jit *jit, struct bpf_prog *fp, int i /* llgc %dst,0(off,%src) */ EMIT6_DISP_LH(0xe3000000, 0x0090, dst_reg, src_reg, REG_0, off); jit->seen |= SEEN_MEM; + if (insn_is_zext(&insn[1])) + insn_count = 2; break; case BPF_LDX | BPF_MEM | BPF_H: /* dst = *(u16 *)(ul) (src + off) */ /* llgh %dst,0(off,%src) */ EMIT6_DISP_LH(0xe3000000, 0x0091, dst_reg, src_reg, REG_0, off); jit->seen |= SEEN_MEM; + if (insn_is_zext(&insn[1])) + insn_count = 2; break; case BPF_LDX | BPF_MEM | BPF_W: /* dst = *(u32 *)(ul) (src + off) */ /* llgf %dst,off(%src) */ jit->seen |= SEEN_MEM; EMIT6_DISP_LH(0xe3000000, 0x0016, dst_reg, src_reg, REG_0, off); + if (insn_is_zext(&insn[1])) + insn_count = 2; break; case BPF_LDX | BPF_MEM | BPF_DW: /* dst = *(u64 *)(ul) (src + off) */ /* lg %dst,0(off,%src) */ @@ -1282,6 +1304,11 @@ static int bpf_jit_prog(struct bpf_jit *jit, struct bpf_prog *fp) return 0; } +bool bpf_jit_needs_zext(void) +{ + return true; +} + /* * Compile eBPF program "fp" */ -- GitLab