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x32: bpf: eliminate zero extension code-gen
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Cc: Wang YanQing <udknight@gmail.com>
Tested-by: Wang YanQing <udknight@gmail.com>
Signed-off-by: Jiong Wang <jiong.wang@netronome.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
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Jiong Wang authored and Alexei Starovoitov committed May 25, 2019
1 parent 3e2a33c commit 836256b
Showing 1 changed file with 56 additions and 27 deletions.
83 changes: 56 additions & 27 deletions arch/x86/net/bpf_jit_comp32.c
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Original file line number Diff line number Diff line change
Expand Up @@ -253,13 +253,14 @@ static inline void emit_ia32_mov_r(const u8 dst, const u8 src, bool dstk,
/* dst = src */
static inline void emit_ia32_mov_r64(const bool is64, const u8 dst[],
const u8 src[], bool dstk,
bool sstk, u8 **pprog)
bool sstk, u8 **pprog,
const struct bpf_prog_aux *aux)
{
emit_ia32_mov_r(dst_lo, src_lo, dstk, sstk, pprog);
if (is64)
/* complete 8 byte move */
emit_ia32_mov_r(dst_hi, src_hi, dstk, sstk, pprog);
else
else if (!aux->verifier_zext)
/* zero out high 4 bytes */
emit_ia32_mov_i(dst_hi, 0, dstk, pprog);
}
Expand Down Expand Up @@ -313,7 +314,8 @@ static inline void emit_ia32_mul_r(const u8 dst, const u8 src, bool dstk,
}

static inline void emit_ia32_to_le_r64(const u8 dst[], s32 val,
bool dstk, u8 **pprog)
bool dstk, u8 **pprog,
const struct bpf_prog_aux *aux)
{
u8 *prog = *pprog;
int cnt = 0;
Expand All @@ -334,12 +336,14 @@ static inline void emit_ia32_to_le_r64(const u8 dst[], s32 val,
*/
EMIT2(0x0F, 0xB7);
EMIT1(add_2reg(0xC0, dreg_lo, dreg_lo));
/* xor dreg_hi,dreg_hi */
EMIT2(0x33, add_2reg(0xC0, dreg_hi, dreg_hi));
if (!aux->verifier_zext)
/* xor dreg_hi,dreg_hi */
EMIT2(0x33, add_2reg(0xC0, dreg_hi, dreg_hi));
break;
case 32:
/* xor dreg_hi,dreg_hi */
EMIT2(0x33, add_2reg(0xC0, dreg_hi, dreg_hi));
if (!aux->verifier_zext)
/* xor dreg_hi,dreg_hi */
EMIT2(0x33, add_2reg(0xC0, dreg_hi, dreg_hi));
break;
case 64:
/* nop */
Expand All @@ -358,7 +362,8 @@ static inline void emit_ia32_to_le_r64(const u8 dst[], s32 val,
}

static inline void emit_ia32_to_be_r64(const u8 dst[], s32 val,
bool dstk, u8 **pprog)
bool dstk, u8 **pprog,
const struct bpf_prog_aux *aux)
{
u8 *prog = *pprog;
int cnt = 0;
Expand All @@ -380,16 +385,18 @@ static inline void emit_ia32_to_be_r64(const u8 dst[], s32 val,
EMIT2(0x0F, 0xB7);
EMIT1(add_2reg(0xC0, dreg_lo, dreg_lo));

/* xor dreg_hi,dreg_hi */
EMIT2(0x33, add_2reg(0xC0, dreg_hi, dreg_hi));
if (!aux->verifier_zext)
/* xor dreg_hi,dreg_hi */
EMIT2(0x33, add_2reg(0xC0, dreg_hi, dreg_hi));
break;
case 32:
/* Emit 'bswap eax' to swap lower 4 bytes */
EMIT1(0x0F);
EMIT1(add_1reg(0xC8, dreg_lo));

/* xor dreg_hi,dreg_hi */
EMIT2(0x33, add_2reg(0xC0, dreg_hi, dreg_hi));
if (!aux->verifier_zext)
/* xor dreg_hi,dreg_hi */
EMIT2(0x33, add_2reg(0xC0, dreg_hi, dreg_hi));
break;
case 64:
/* Emit 'bswap eax' to swap lower 4 bytes */
Expand Down Expand Up @@ -569,15 +576,15 @@ static inline void emit_ia32_alu_r(const bool is64, const bool hi, const u8 op,
static inline void emit_ia32_alu_r64(const bool is64, const u8 op,
const u8 dst[], const u8 src[],
bool dstk, bool sstk,
u8 **pprog)
u8 **pprog, const struct bpf_prog_aux *aux)
{
u8 *prog = *pprog;

emit_ia32_alu_r(is64, false, op, dst_lo, src_lo, dstk, sstk, &prog);
if (is64)
emit_ia32_alu_r(is64, true, op, dst_hi, src_hi, dstk, sstk,
&prog);
else
else if (!aux->verifier_zext)
emit_ia32_mov_i(dst_hi, 0, dstk, &prog);
*pprog = prog;
}
Expand Down Expand Up @@ -668,7 +675,8 @@ static inline void emit_ia32_alu_i(const bool is64, const bool hi, const u8 op,
/* ALU operation (64 bit) */
static inline void emit_ia32_alu_i64(const bool is64, const u8 op,
const u8 dst[], const u32 val,
bool dstk, u8 **pprog)
bool dstk, u8 **pprog,
const struct bpf_prog_aux *aux)
{
u8 *prog = *pprog;
u32 hi = 0;
Expand All @@ -679,7 +687,7 @@ static inline void emit_ia32_alu_i64(const bool is64, const u8 op,
emit_ia32_alu_i(is64, false, op, dst_lo, val, dstk, &prog);
if (is64)
emit_ia32_alu_i(is64, true, op, dst_hi, hi, dstk, &prog);
else
else if (!aux->verifier_zext)
emit_ia32_mov_i(dst_hi, 0, dstk, &prog);

*pprog = prog;
Expand Down Expand Up @@ -1713,8 +1721,13 @@ static int do_jit(struct bpf_prog *bpf_prog, int *addrs, u8 *image,
case BPF_ALU64 | BPF_MOV | BPF_X:
switch (BPF_SRC(code)) {
case BPF_X:
emit_ia32_mov_r64(is64, dst, src, dstk,
sstk, &prog);
if (imm32 == 1) {
/* Special mov32 for zext. */
emit_ia32_mov_i(dst_hi, 0, dstk, &prog);
break;
}
emit_ia32_mov_r64(is64, dst, src, dstk, sstk,
&prog, bpf_prog->aux);
break;
case BPF_K:
/* Sign-extend immediate value to dst reg */
Expand Down Expand Up @@ -1754,11 +1767,13 @@ static int do_jit(struct bpf_prog *bpf_prog, int *addrs, u8 *image,
switch (BPF_SRC(code)) {
case BPF_X:
emit_ia32_alu_r64(is64, BPF_OP(code), dst,
src, dstk, sstk, &prog);
src, dstk, sstk, &prog,
bpf_prog->aux);
break;
case BPF_K:
emit_ia32_alu_i64(is64, BPF_OP(code), dst,
imm32, dstk, &prog);
imm32, dstk, &prog,
bpf_prog->aux);
break;
}
break;
Expand All @@ -1777,7 +1792,8 @@ static int do_jit(struct bpf_prog *bpf_prog, int *addrs, u8 *image,
false, &prog);
break;
}
emit_ia32_mov_i(dst_hi, 0, dstk, &prog);
if (!bpf_prog->aux->verifier_zext)
emit_ia32_mov_i(dst_hi, 0, dstk, &prog);
break;
case BPF_ALU | BPF_LSH | BPF_X:
case BPF_ALU | BPF_RSH | BPF_X:
Expand All @@ -1797,7 +1813,8 @@ static int do_jit(struct bpf_prog *bpf_prog, int *addrs, u8 *image,
&prog);
break;
}
emit_ia32_mov_i(dst_hi, 0, dstk, &prog);
if (!bpf_prog->aux->verifier_zext)
emit_ia32_mov_i(dst_hi, 0, dstk, &prog);
break;
/* dst = dst / src(imm) */
/* dst = dst % src(imm) */
Expand All @@ -1819,7 +1836,8 @@ static int do_jit(struct bpf_prog *bpf_prog, int *addrs, u8 *image,
&prog);
break;
}
emit_ia32_mov_i(dst_hi, 0, dstk, &prog);
if (!bpf_prog->aux->verifier_zext)
emit_ia32_mov_i(dst_hi, 0, dstk, &prog);
break;
case BPF_ALU64 | BPF_DIV | BPF_K:
case BPF_ALU64 | BPF_DIV | BPF_X:
Expand All @@ -1836,7 +1854,8 @@ static int do_jit(struct bpf_prog *bpf_prog, int *addrs, u8 *image,
EMIT2_off32(0xC7, add_1reg(0xC0, IA32_ECX), imm32);
emit_ia32_shift_r(BPF_OP(code), dst_lo, IA32_ECX, dstk,
false, &prog);
emit_ia32_mov_i(dst_hi, 0, dstk, &prog);
if (!bpf_prog->aux->verifier_zext)
emit_ia32_mov_i(dst_hi, 0, dstk, &prog);
break;
/* dst = dst << imm */
case BPF_ALU64 | BPF_LSH | BPF_K:
Expand Down Expand Up @@ -1872,7 +1891,8 @@ static int do_jit(struct bpf_prog *bpf_prog, int *addrs, u8 *image,
case BPF_ALU | BPF_NEG:
emit_ia32_alu_i(is64, false, BPF_OP(code),
dst_lo, 0, dstk, &prog);
emit_ia32_mov_i(dst_hi, 0, dstk, &prog);
if (!bpf_prog->aux->verifier_zext)
emit_ia32_mov_i(dst_hi, 0, dstk, &prog);
break;
/* dst = ~dst (64 bit) */
case BPF_ALU64 | BPF_NEG:
Expand All @@ -1892,11 +1912,13 @@ static int do_jit(struct bpf_prog *bpf_prog, int *addrs, u8 *image,
break;
/* dst = htole(dst) */
case BPF_ALU | BPF_END | BPF_FROM_LE:
emit_ia32_to_le_r64(dst, imm32, dstk, &prog);
emit_ia32_to_le_r64(dst, imm32, dstk, &prog,
bpf_prog->aux);
break;
/* dst = htobe(dst) */
case BPF_ALU | BPF_END | BPF_FROM_BE:
emit_ia32_to_be_r64(dst, imm32, dstk, &prog);
emit_ia32_to_be_r64(dst, imm32, dstk, &prog,
bpf_prog->aux);
break;
/* dst = imm64 */
case BPF_LD | BPF_IMM | BPF_DW: {
Expand Down Expand Up @@ -2051,6 +2073,8 @@ static int do_jit(struct bpf_prog *bpf_prog, int *addrs, u8 *image,
case BPF_B:
case BPF_H:
case BPF_W:
if (!bpf_prog->aux->verifier_zext)
break;
if (dstk) {
EMIT3(0xC7, add_1reg(0x40, IA32_EBP),
STACK_VAR(dst_hi));
Expand Down Expand Up @@ -2475,6 +2499,11 @@ emit_cond_jmp: jmp_cond = get_cond_jmp_opcode(BPF_OP(code), false);
return proglen;
}

bool bpf_jit_needs_zext(void)
{
return true;
}

struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog)
{
struct bpf_binary_header *header = NULL;
Expand Down

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