linux-stable/tools/testing/selftests/bpf/verifier/jit.c
Wang YanQing 711aef1bbf bpf, x32: Fix bug for BPF_JMP | {BPF_JSGT, BPF_JSLE, BPF_JSLT, BPF_JSGE}
The current method to compare 64-bit numbers for conditional jump is:

1) Compare the high 32-bit first.

2) If the high 32-bit isn't the same, then goto step 4.

3) Compare the low 32-bit.

4) Check the desired condition.

This method is right for unsigned comparison, but it is buggy for signed
comparison, because it does signed comparison for low 32-bit too.

There is only one sign bit in 64-bit number, that is the MSB in the 64-bit
number, it is wrong to treat low 32-bit as signed number and do the signed
comparison for it.

This patch fixes the bug and adds a testcase in selftests/bpf for such bug.

Signed-off-by: Wang YanQing <udknight@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-05-01 23:32:16 +02:00

107 lines
2.8 KiB
C

{
"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_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_0, 0x952a7bbcULL),
BPF_LD_IMM64(BPF_REG_1, 0xfefefeULL),
BPF_LD_IMM64(BPF_REG_2, 0xeeff0d413122ULL),
BPF_ALU32_REG(BPF_MUL, BPF_REG_2, BPF_REG_1),
BPF_JMP_REG(BPF_JEQ, BPF_REG_2, 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: 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,
},