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linux/tools/testing/selftests/bpf/verifier/jit.c
Jie Meng 57a610f1c5 bpf, x64: Save bytes for DIV by reducing reg copies 
Instead of unconditionally performing push/pop on %rax/%rdx in case of
division/modulo, we can save a few bytes in case of destination register
being either BPF r0 (%rax) or r3 (%rdx) since the result is written in
there anyway.

Also, we do not need to copy the source to %r11 unless the source is either
%rax, %rdx or an immediate.

For example, before the patch:

  22:   push   %rax
  23:   push   %rdx
  24:   mov    %rsi,%r11
  27:   xor    %edx,%edx
  29:   div    %r11
  2c:   mov    %rax,%r11
  2f:   pop    %rdx
  30:   pop    %rax
  31:   mov    %r11,%rax

After:

  22:   push   %rdx
  23:   xor    %edx,%edx
  25:   div    %rsi
  28:   pop    %rdx

Signed-off-by: Jie Meng <jmeng@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Tested-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20211002035626.2041910-1-jmeng@fb.com
2021-10-06 15:24:36 +02:00

195 lines
5.4 KiB
C
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{
"jit: lsh, rsh, arsh by 1",
.insns = {
BPF_MOV64_IMM(BPF_REG_0, 1),
BPF_MOV64_IMM(BPF_REG_1, 0xff),
BPF_ALU64_IMM(BPF_LSH, BPF_REG_1, 1),
BPF_ALU32_IMM(BPF_LSH, BPF_REG_1, 1),
BPF_JMP_IMM(BPF_JEQ, BPF_REG_1, 0x3fc, 1),
BPF_EXIT_INSN(),
BPF_ALU64_IMM(BPF_RSH, BPF_REG_1, 1),
BPF_ALU32_IMM(BPF_RSH, BPF_REG_1, 1),
BPF_JMP_IMM(BPF_JEQ, BPF_REG_1, 0xff, 1),
BPF_EXIT_INSN(),
BPF_ALU64_IMM(BPF_ARSH, BPF_REG_1, 1),
BPF_JMP_IMM(BPF_JEQ, BPF_REG_1, 0x7f, 1),
BPF_EXIT_INSN(),
BPF_MOV64_IMM(BPF_REG_0, 2),
BPF_EXIT_INSN(),
},
.result = ACCEPT,
.retval = 2,
},
{
"jit: mov32 for ldimm64, 1",
.insns = {
BPF_MOV64_IMM(BPF_REG_0, 2),
BPF_LD_IMM64(BPF_REG_1, 0xfeffffffffffffffULL),
BPF_ALU64_IMM(BPF_RSH, BPF_REG_1, 32),
BPF_LD_IMM64(BPF_REG_2, 0xfeffffffULL),
BPF_JMP_REG(BPF_JEQ, BPF_REG_1, BPF_REG_2, 1),
BPF_MOV64_IMM(BPF_REG_0, 1),
BPF_EXIT_INSN(),
},
.result = ACCEPT,
.retval = 2,
},
{
"jit: mov32 for ldimm64, 2",
.insns = {
BPF_MOV64_IMM(BPF_REG_0, 1),
BPF_LD_IMM64(BPF_REG_1, 0x1ffffffffULL),
BPF_LD_IMM64(BPF_REG_2, 0xffffffffULL),
BPF_JMP_REG(BPF_JEQ, BPF_REG_1, BPF_REG_2, 1),
BPF_MOV64_IMM(BPF_REG_0, 2),
BPF_EXIT_INSN(),
},
.result = ACCEPT,
.retval = 2,
},
{
"jit: various mul tests",
.insns = {
BPF_LD_IMM64(BPF_REG_2, 0xeeff0d413122ULL),
BPF_LD_IMM64(BPF_REG_0, 0xfefefeULL),
BPF_LD_IMM64(BPF_REG_1, 0xefefefULL),
BPF_ALU64_REG(BPF_MUL, BPF_REG_0, BPF_REG_1),
BPF_JMP_REG(BPF_JEQ, BPF_REG_0, BPF_REG_2, 2),
BPF_MOV64_IMM(BPF_REG_0, 1),
BPF_EXIT_INSN(),
BPF_LD_IMM64(BPF_REG_3, 0xfefefeULL),
BPF_ALU64_REG(BPF_MUL, BPF_REG_3, BPF_REG_1),
BPF_JMP_REG(BPF_JEQ, BPF_REG_3, BPF_REG_2, 2),
BPF_MOV64_IMM(BPF_REG_0, 1),
BPF_EXIT_INSN(),
BPF_LD_IMM64(BPF_REG_3, 0xfefefeULL),
BPF_ALU64_IMM(BPF_MUL, BPF_REG_3, 0xefefef),
BPF_JMP_REG(BPF_JEQ, BPF_REG_3, BPF_REG_2, 2),
BPF_MOV64_IMM(BPF_REG_0, 1),
BPF_EXIT_INSN(),
BPF_MOV32_REG(BPF_REG_2, BPF_REG_2),
BPF_LD_IMM64(BPF_REG_0, 0xfefefeULL),
BPF_ALU32_REG(BPF_MUL, BPF_REG_0, BPF_REG_1),
BPF_JMP_REG(BPF_JEQ, BPF_REG_0, BPF_REG_2, 2),
BPF_MOV64_IMM(BPF_REG_0, 1),
BPF_EXIT_INSN(),
BPF_LD_IMM64(BPF_REG_3, 0xfefefeULL),
BPF_ALU32_REG(BPF_MUL, BPF_REG_3, BPF_REG_1),
BPF_JMP_REG(BPF_JEQ, BPF_REG_3, BPF_REG_2, 2),
BPF_MOV64_IMM(BPF_REG_0, 1),
BPF_EXIT_INSN(),
BPF_LD_IMM64(BPF_REG_3, 0xfefefeULL),
BPF_ALU32_IMM(BPF_MUL, BPF_REG_3, 0xefefef),
BPF_JMP_REG(BPF_JEQ, BPF_REG_3, BPF_REG_2, 2),
BPF_MOV64_IMM(BPF_REG_0, 1),
BPF_EXIT_INSN(),
BPF_LD_IMM64(BPF_REG_0, 0xfefefeULL),
BPF_LD_IMM64(BPF_REG_2, 0x2ad4d4aaULL),
BPF_ALU32_IMM(BPF_MUL, BPF_REG_0, 0x2b),
BPF_JMP_REG(BPF_JEQ, BPF_REG_0, BPF_REG_2, 2),
BPF_MOV64_IMM(BPF_REG_0, 1),
BPF_EXIT_INSN(),
BPF_LD_IMM64(BPF_REG_0, 0x952a7bbcULL),
BPF_LD_IMM64(BPF_REG_1, 0xfefefeULL),
BPF_LD_IMM64(BPF_REG_5, 0xeeff0d413122ULL),
BPF_ALU32_REG(BPF_MUL, BPF_REG_5, BPF_REG_1),
BPF_JMP_REG(BPF_JEQ, BPF_REG_5, BPF_REG_0, 2),
BPF_MOV64_IMM(BPF_REG_0, 1),
BPF_EXIT_INSN(),
BPF_MOV64_IMM(BPF_REG_0, 2),
BPF_EXIT_INSN(),
},
.result = ACCEPT,
.retval = 2,
},
{
"jit: various div tests",
.insns = {
BPF_LD_IMM64(BPF_REG_2, 0xefeffeULL),
BPF_LD_IMM64(BPF_REG_0, 0xeeff0d413122ULL),
BPF_LD_IMM64(BPF_REG_1, 0xfefeeeULL),
BPF_ALU64_REG(BPF_DIV, BPF_REG_0, BPF_REG_1),
BPF_JMP_REG(BPF_JEQ, BPF_REG_0, BPF_REG_2, 2),
BPF_MOV64_IMM(BPF_REG_0, 1),
BPF_EXIT_INSN(),
BPF_LD_IMM64(BPF_REG_3, 0xeeff0d413122ULL),
BPF_ALU64_IMM(BPF_DIV, BPF_REG_3, 0xfefeeeULL),
BPF_JMP_REG(BPF_JEQ, BPF_REG_3, BPF_REG_2, 2),
BPF_MOV64_IMM(BPF_REG_0, 1),
BPF_EXIT_INSN(),
BPF_LD_IMM64(BPF_REG_2, 0xaa93ULL),
BPF_ALU64_IMM(BPF_MOD, BPF_REG_1, 0xbeefULL),
BPF_JMP_REG(BPF_JEQ, BPF_REG_1, BPF_REG_2, 2),
BPF_MOV64_IMM(BPF_REG_0, 1),
BPF_EXIT_INSN(),
BPF_LD_IMM64(BPF_REG_1, 0xfefeeeULL),
BPF_LD_IMM64(BPF_REG_3, 0xbeefULL),
BPF_ALU64_REG(BPF_MOD, BPF_REG_1, BPF_REG_3),
BPF_JMP_REG(BPF_JEQ, BPF_REG_1, BPF_REG_2, 2),
BPF_MOV64_IMM(BPF_REG_0, 1),
BPF_EXIT_INSN(),
BPF_LD_IMM64(BPF_REG_2, 0x5ee1dULL),
BPF_LD_IMM64(BPF_REG_1, 0xfefeeeULL),
BPF_LD_IMM64(BPF_REG_3, 0x2bULL),
BPF_ALU32_REG(BPF_DIV, BPF_REG_1, BPF_REG_3),
BPF_JMP_REG(BPF_JEQ, BPF_REG_1, BPF_REG_2, 2),
BPF_MOV64_IMM(BPF_REG_0, 1),
BPF_EXIT_INSN(),
BPF_ALU32_REG(BPF_DIV, BPF_REG_1, BPF_REG_1),
BPF_JMP_IMM(BPF_JEQ, BPF_REG_1, 1, 2),
BPF_MOV64_IMM(BPF_REG_0, 1),
BPF_EXIT_INSN(),
BPF_ALU64_REG(BPF_MOD, BPF_REG_2, BPF_REG_2),
BPF_JMP_IMM(BPF_JEQ, BPF_REG_2, 0, 2),
BPF_MOV64_IMM(BPF_REG_0, 1),
BPF_EXIT_INSN(),
BPF_MOV64_IMM(BPF_REG_0, 2),
BPF_EXIT_INSN(),
},
.result = ACCEPT,
.retval = 2,
},
{
"jit: jsgt, jslt",
.insns = {
BPF_LD_IMM64(BPF_REG_1, 0x80000000ULL),
BPF_LD_IMM64(BPF_REG_2, 0x0ULL),
BPF_JMP_REG(BPF_JSGT, BPF_REG_1, BPF_REG_2, 2),
BPF_MOV64_IMM(BPF_REG_0, 1),
BPF_EXIT_INSN(),
BPF_JMP_REG(BPF_JSLT, BPF_REG_2, BPF_REG_1, 2),
BPF_MOV64_IMM(BPF_REG_0, 1),
BPF_EXIT_INSN(),
BPF_MOV64_IMM(BPF_REG_0, 2),
BPF_EXIT_INSN(),
},
.result = ACCEPT,
.retval = 2,
},
{
"jit: torturous jumps, imm8 nop jmp and pure jump padding",
.insns = { },
.fill_helper = bpf_fill_torturous_jumps,
.prog_type = BPF_PROG_TYPE_SCHED_CLS,
.result = ACCEPT,
.retval = 1,
},
{
"jit: torturous jumps, imm32 nop jmp and jmp_cond padding",
.insns = { },
.fill_helper = bpf_fill_torturous_jumps,
.prog_type = BPF_PROG_TYPE_SCHED_CLS,
.result = ACCEPT,
.retval = 2,
},
{
"jit: torturous jumps in subprog",
.insns = { },
.fill_helper = bpf_fill_torturous_jumps,
.prog_type = BPF_PROG_TYPE_SCHED_CLS,
.result = ACCEPT,
.retval = 3,
},
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