From: Jie Meng jmeng@fb.com
commit 6364d7d75a0e015a405d1f8a07f267f076c36ca6 upstream.
Introduce a single reg version of maybe_emit_mod() and factor out common code in more cases.
Signed-off-by: Jie Meng jmeng@fb.com Signed-off-by: Daniel Borkmann daniel@iogearbox.net Acked-by: Song Liu songliubraving@fb.com Link: https://lore.kernel.org/bpf/20211006194135.608932-1-jmeng@fb.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- arch/x86/net/bpf_jit_comp.c | 50 ++++++++++++++++++++++---------------------- 1 file changed, 26 insertions(+), 24 deletions(-)
--- a/arch/x86/net/bpf_jit_comp.c +++ b/arch/x86/net/bpf_jit_comp.c @@ -721,6 +721,20 @@ static void maybe_emit_mod(u8 **pprog, u *pprog = prog; }
+/* + * Similar version of maybe_emit_mod() for a single register + */ +static void maybe_emit_1mod(u8 **pprog, u32 reg, bool is64) +{ + u8 *prog = *pprog; + + if (is64) + EMIT1(add_1mod(0x48, reg)); + else if (is_ereg(reg)) + EMIT1(add_1mod(0x40, reg)); + *pprog = prog; +} + /* LDX: dst_reg = *(u8*)(src_reg + off) */ static void emit_ldx(u8 **pprog, u32 size, u32 dst_reg, u32 src_reg, int off) { @@ -951,10 +965,8 @@ static int do_jit(struct bpf_prog *bpf_p /* neg dst */ case BPF_ALU | BPF_NEG: case BPF_ALU64 | BPF_NEG: - if (BPF_CLASS(insn->code) == BPF_ALU64) - EMIT1(add_1mod(0x48, dst_reg)); - else if (is_ereg(dst_reg)) - EMIT1(add_1mod(0x40, dst_reg)); + maybe_emit_1mod(&prog, dst_reg, + BPF_CLASS(insn->code) == BPF_ALU64); EMIT2(0xF7, add_1reg(0xD8, dst_reg)); break;
@@ -968,10 +980,8 @@ static int do_jit(struct bpf_prog *bpf_p case BPF_ALU64 | BPF_AND | BPF_K: case BPF_ALU64 | BPF_OR | BPF_K: case BPF_ALU64 | BPF_XOR | BPF_K: - if (BPF_CLASS(insn->code) == BPF_ALU64) - EMIT1(add_1mod(0x48, dst_reg)); - else if (is_ereg(dst_reg)) - EMIT1(add_1mod(0x40, dst_reg)); + maybe_emit_1mod(&prog, dst_reg, + BPF_CLASS(insn->code) == BPF_ALU64);
/* * b3 holds 'normal' opcode, b2 short form only valid @@ -1112,10 +1122,8 @@ static int do_jit(struct bpf_prog *bpf_p case BPF_ALU64 | BPF_LSH | BPF_K: case BPF_ALU64 | BPF_RSH | BPF_K: case BPF_ALU64 | BPF_ARSH | BPF_K: - if (BPF_CLASS(insn->code) == BPF_ALU64) - EMIT1(add_1mod(0x48, dst_reg)); - else if (is_ereg(dst_reg)) - EMIT1(add_1mod(0x40, dst_reg)); + maybe_emit_1mod(&prog, dst_reg, + BPF_CLASS(insn->code) == BPF_ALU64);
b3 = simple_alu_opcodes[BPF_OP(insn->code)]; if (imm32 == 1) @@ -1146,10 +1154,8 @@ static int do_jit(struct bpf_prog *bpf_p }
/* shl %rax, %cl | shr %rax, %cl | sar %rax, %cl */ - if (BPF_CLASS(insn->code) == BPF_ALU64) - EMIT1(add_1mod(0x48, dst_reg)); - else if (is_ereg(dst_reg)) - EMIT1(add_1mod(0x40, dst_reg)); + maybe_emit_1mod(&prog, dst_reg, + BPF_CLASS(insn->code) == BPF_ALU64);
b3 = simple_alu_opcodes[BPF_OP(insn->code)]; EMIT2(0xD3, add_1reg(b3, dst_reg)); @@ -1459,10 +1465,8 @@ st: if (is_imm8(insn->off)) case BPF_JMP | BPF_JSET | BPF_K: case BPF_JMP32 | BPF_JSET | BPF_K: /* test dst_reg, imm32 */ - if (BPF_CLASS(insn->code) == BPF_JMP) - EMIT1(add_1mod(0x48, dst_reg)); - else if (is_ereg(dst_reg)) - EMIT1(add_1mod(0x40, dst_reg)); + maybe_emit_1mod(&prog, dst_reg, + BPF_CLASS(insn->code) == BPF_JMP); EMIT2_off32(0xF7, add_1reg(0xC0, dst_reg), imm32); goto emit_cond_jmp;
@@ -1495,10 +1499,8 @@ st: if (is_imm8(insn->off)) }
/* cmp dst_reg, imm8/32 */ - if (BPF_CLASS(insn->code) == BPF_JMP) - EMIT1(add_1mod(0x48, dst_reg)); - else if (is_ereg(dst_reg)) - EMIT1(add_1mod(0x40, dst_reg)); + maybe_emit_1mod(&prog, dst_reg, + BPF_CLASS(insn->code) == BPF_JMP);
if (is_imm8(imm32)) EMIT3(0x83, add_1reg(0xF8, dst_reg), imm32);