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authorJiong Wang <jiong.wang@netronome.com>2019-05-24 23:25:22 +0100
committerAlexei Starovoitov <ast@kernel.org>2019-05-24 18:58:37 -0700
commit163541e6ba3426b21884af5a2f498c9d2ce77f00 (patch)
tree39a68dd196aa308d09e4519dabfa42dd142e9863 /arch/arm/net
parent9d120b4127e8df04ee665241916056b0156b37c7 (diff)
arm: bpf: eliminate zero extension code-gen
Cc: Shubham Bansal <illusionist.neo@gmail.com> Signed-off-by: Jiong Wang <jiong.wang@netronome.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Diffstat (limited to 'arch/arm/net')
-rw-r--r--arch/arm/net/bpf_jit_32.c42
1 files changed, 31 insertions, 11 deletions
diff --git a/arch/arm/net/bpf_jit_32.c b/arch/arm/net/bpf_jit_32.c
index c8bfbbfdfcc3..97a6b4b2a115 100644
--- a/arch/arm/net/bpf_jit_32.c
+++ b/arch/arm/net/bpf_jit_32.c
@@ -736,7 +736,8 @@ static inline void emit_a32_alu_r64(const bool is64, const s8 dst[],
/* ALU operation */
emit_alu_r(rd[1], rs, true, false, op, ctx);
- emit_a32_mov_i(rd[0], 0, ctx);
+ if (!ctx->prog->aux->verifier_zext)
+ emit_a32_mov_i(rd[0], 0, ctx);
}
arm_bpf_put_reg64(dst, rd, ctx);
@@ -758,8 +759,9 @@ static inline void emit_a32_mov_r64(const bool is64, const s8 dst[],
struct jit_ctx *ctx) {
if (!is64) {
emit_a32_mov_r(dst_lo, src_lo, ctx);
- /* Zero out high 4 bytes */
- emit_a32_mov_i(dst_hi, 0, ctx);
+ if (!ctx->prog->aux->verifier_zext)
+ /* Zero out high 4 bytes */
+ emit_a32_mov_i(dst_hi, 0, ctx);
} else if (__LINUX_ARM_ARCH__ < 6 &&
ctx->cpu_architecture < CPU_ARCH_ARMv5TE) {
/* complete 8 byte move */
@@ -1060,17 +1062,20 @@ static inline void emit_ldx_r(const s8 dst[], const s8 src,
case BPF_B:
/* Load a Byte */
emit(ARM_LDRB_I(rd[1], rm, off), ctx);
- emit_a32_mov_i(rd[0], 0, ctx);
+ if (!ctx->prog->aux->verifier_zext)
+ emit_a32_mov_i(rd[0], 0, ctx);
break;
case BPF_H:
/* Load a HalfWord */
emit(ARM_LDRH_I(rd[1], rm, off), ctx);
- emit_a32_mov_i(rd[0], 0, ctx);
+ if (!ctx->prog->aux->verifier_zext)
+ emit_a32_mov_i(rd[0], 0, ctx);
break;
case BPF_W:
/* Load a Word */
emit(ARM_LDR_I(rd[1], rm, off), ctx);
- emit_a32_mov_i(rd[0], 0, ctx);
+ if (!ctx->prog->aux->verifier_zext)
+ emit_a32_mov_i(rd[0], 0, ctx);
break;
case BPF_DW:
/* Load a Double Word */
@@ -1359,6 +1364,11 @@ static int build_insn(const struct bpf_insn *insn, struct jit_ctx *ctx)
case BPF_ALU64 | BPF_MOV | BPF_X:
switch (BPF_SRC(code)) {
case BPF_X:
+ if (imm == 1) {
+ /* Special mov32 for zext */
+ emit_a32_mov_i(dst_hi, 0, ctx);
+ break;
+ }
emit_a32_mov_r64(is64, dst, src, ctx);
break;
case BPF_K:
@@ -1438,7 +1448,8 @@ static int build_insn(const struct bpf_insn *insn, struct jit_ctx *ctx)
}
emit_udivmod(rd_lo, rd_lo, rt, ctx, BPF_OP(code));
arm_bpf_put_reg32(dst_lo, rd_lo, ctx);
- emit_a32_mov_i(dst_hi, 0, ctx);
+ if (!ctx->prog->aux->verifier_zext)
+ emit_a32_mov_i(dst_hi, 0, ctx);
break;
case BPF_ALU64 | BPF_DIV | BPF_K:
case BPF_ALU64 | BPF_DIV | BPF_X:
@@ -1453,7 +1464,8 @@ static int build_insn(const struct bpf_insn *insn, struct jit_ctx *ctx)
return -EINVAL;
if (imm)
emit_a32_alu_i(dst_lo, imm, ctx, BPF_OP(code));
- emit_a32_mov_i(dst_hi, 0, ctx);
+ if (!ctx->prog->aux->verifier_zext)
+ emit_a32_mov_i(dst_hi, 0, ctx);
break;
/* dst = dst << imm */
case BPF_ALU64 | BPF_LSH | BPF_K:
@@ -1488,7 +1500,8 @@ static int build_insn(const struct bpf_insn *insn, struct jit_ctx *ctx)
/* dst = ~dst */
case BPF_ALU | BPF_NEG:
emit_a32_alu_i(dst_lo, 0, ctx, BPF_OP(code));
- emit_a32_mov_i(dst_hi, 0, ctx);
+ if (!ctx->prog->aux->verifier_zext)
+ emit_a32_mov_i(dst_hi, 0, ctx);
break;
/* dst = ~dst (64 bit) */
case BPF_ALU64 | BPF_NEG:
@@ -1544,11 +1557,13 @@ emit_bswap_uxt:
#else /* ARMv6+ */
emit(ARM_UXTH(rd[1], rd[1]), ctx);
#endif
- emit(ARM_EOR_R(rd[0], rd[0], rd[0]), ctx);
+ if (!ctx->prog->aux->verifier_zext)
+ emit(ARM_EOR_R(rd[0], rd[0], rd[0]), ctx);
break;
case 32:
/* zero-extend 32 bits into 64 bits */
- emit(ARM_EOR_R(rd[0], rd[0], rd[0]), ctx);
+ if (!ctx->prog->aux->verifier_zext)
+ emit(ARM_EOR_R(rd[0], rd[0], rd[0]), ctx);
break;
case 64:
/* nop */
@@ -1838,6 +1853,11 @@ void bpf_jit_compile(struct bpf_prog *prog)
/* Nothing to do here. We support Internal BPF. */
}
+bool bpf_jit_needs_zext(void)
+{
+ return true;
+}
+
struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog)
{
struct bpf_prog *tmp, *orig_prog = prog;