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path: root/arch/x86/net/bpf_jit_comp.c
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Diffstat (limited to 'arch/x86/net/bpf_jit_comp.c')
-rw-r--r--arch/x86/net/bpf_jit_comp.c130
1 files changed, 69 insertions, 61 deletions
diff --git a/arch/x86/net/bpf_jit_comp.c b/arch/x86/net/bpf_jit_comp.c
index 576ef1a6954a..e474718d152b 100644
--- 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, u32 dst_reg, u32 src_reg, bool is64)
*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_prog, int *addrs, u8 *image,
/* 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_prog, int *addrs, u8 *image,
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
@@ -1028,19 +1038,30 @@ static int do_jit(struct bpf_prog *bpf_prog, int *addrs, u8 *image,
case BPF_ALU64 | BPF_MOD | BPF_X:
case BPF_ALU64 | BPF_DIV | BPF_X:
case BPF_ALU64 | BPF_MOD | BPF_K:
- case BPF_ALU64 | BPF_DIV | BPF_K:
- EMIT1(0x50); /* push rax */
- EMIT1(0x52); /* push rdx */
-
- if (BPF_SRC(insn->code) == BPF_X)
- /* mov r11, src_reg */
- EMIT_mov(AUX_REG, src_reg);
- else
+ case BPF_ALU64 | BPF_DIV | BPF_K: {
+ bool is64 = BPF_CLASS(insn->code) == BPF_ALU64;
+
+ if (dst_reg != BPF_REG_0)
+ EMIT1(0x50); /* push rax */
+ if (dst_reg != BPF_REG_3)
+ EMIT1(0x52); /* push rdx */
+
+ if (BPF_SRC(insn->code) == BPF_X) {
+ if (src_reg == BPF_REG_0 ||
+ src_reg == BPF_REG_3) {
+ /* mov r11, src_reg */
+ EMIT_mov(AUX_REG, src_reg);
+ src_reg = AUX_REG;
+ }
+ } else {
/* mov r11, imm32 */
EMIT3_off32(0x49, 0xC7, 0xC3, imm32);
+ src_reg = AUX_REG;
+ }
- /* mov rax, dst_reg */
- EMIT_mov(BPF_REG_0, dst_reg);
+ if (dst_reg != BPF_REG_0)
+ /* mov rax, dst_reg */
+ emit_mov_reg(&prog, is64, BPF_REG_0, dst_reg);
/*
* xor edx, edx
@@ -1048,33 +1069,30 @@ static int do_jit(struct bpf_prog *bpf_prog, int *addrs, u8 *image,
*/
EMIT2(0x31, 0xd2);
- if (BPF_CLASS(insn->code) == BPF_ALU64)
- /* div r11 */
- EMIT3(0x49, 0xF7, 0xF3);
- else
- /* div r11d */
- EMIT3(0x41, 0xF7, 0xF3);
-
- if (BPF_OP(insn->code) == BPF_MOD)
- /* mov r11, rdx */
- EMIT3(0x49, 0x89, 0xD3);
- else
- /* mov r11, rax */
- EMIT3(0x49, 0x89, 0xC3);
-
- EMIT1(0x5A); /* pop rdx */
- EMIT1(0x58); /* pop rax */
-
- /* mov dst_reg, r11 */
- EMIT_mov(dst_reg, AUX_REG);
+ /* div src_reg */
+ maybe_emit_1mod(&prog, src_reg, is64);
+ EMIT2(0xF7, add_1reg(0xF0, src_reg));
+
+ if (BPF_OP(insn->code) == BPF_MOD &&
+ dst_reg != BPF_REG_3)
+ /* mov dst_reg, rdx */
+ emit_mov_reg(&prog, is64, dst_reg, BPF_REG_3);
+ else if (BPF_OP(insn->code) == BPF_DIV &&
+ dst_reg != BPF_REG_0)
+ /* mov dst_reg, rax */
+ emit_mov_reg(&prog, is64, dst_reg, BPF_REG_0);
+
+ if (dst_reg != BPF_REG_3)
+ EMIT1(0x5A); /* pop rdx */
+ if (dst_reg != BPF_REG_0)
+ EMIT1(0x58); /* pop rax */
break;
+ }
case BPF_ALU | BPF_MUL | BPF_K:
case BPF_ALU64 | BPF_MUL | BPF_K:
- if (BPF_CLASS(insn->code) == BPF_ALU64)
- EMIT1(add_2mod(0x48, dst_reg, dst_reg));
- else if (is_ereg(dst_reg))
- EMIT1(add_2mod(0x40, dst_reg, dst_reg));
+ maybe_emit_mod(&prog, dst_reg, dst_reg,
+ BPF_CLASS(insn->code) == BPF_ALU64);
if (is_imm8(imm32))
/* imul dst_reg, dst_reg, imm8 */
@@ -1089,10 +1107,8 @@ static int do_jit(struct bpf_prog *bpf_prog, int *addrs, u8 *image,
case BPF_ALU | BPF_MUL | BPF_X:
case BPF_ALU64 | BPF_MUL | BPF_X:
- if (BPF_CLASS(insn->code) == BPF_ALU64)
- EMIT1(add_2mod(0x48, src_reg, dst_reg));
- else if (is_ereg(dst_reg) || is_ereg(src_reg))
- EMIT1(add_2mod(0x40, src_reg, dst_reg));
+ maybe_emit_mod(&prog, src_reg, dst_reg,
+ BPF_CLASS(insn->code) == BPF_ALU64);
/* imul dst_reg, src_reg */
EMIT3(0x0F, 0xAF, add_2reg(0xC0, src_reg, dst_reg));
@@ -1105,10 +1121,8 @@ static int do_jit(struct bpf_prog *bpf_prog, int *addrs, u8 *image,
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)
@@ -1139,10 +1153,8 @@ static int do_jit(struct bpf_prog *bpf_prog, int *addrs, u8 *image,
}
/* 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));
@@ -1452,10 +1464,8 @@ 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;
@@ -1488,10 +1498,8 @@ 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);
generated by cgit v1.2.3-70-g09d2 (git 2.48.1) at 2025-09-25 02:08:55 +0000