Re: [PATCH bpf-next 02/11] bpf: add also cbpf long jump test cases with heavy expansion

[Song Liu <liu.song.a23@gmail.com>]

On Sun, May 27, 2018 at 5:43 PM, Daniel Borkmann <daniel@iogearbox.net> wrote:
> We have one triggering on eBPF but lets also add a cBPF example to
> make sure we keep tracking them. Also add anther cBPF test running
> max number of MSH ops.
>
> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
> Acked-by: Alexei Starovoitov <ast@kernel.org>

Acked-by: Song Liu <songliubraving@fb.com>


> ---
>  lib/test_bpf.c | 63 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 63 insertions(+)
>
> diff --git a/lib/test_bpf.c b/lib/test_bpf.c
> index 317f231..60aedc8 100644
> --- a/lib/test_bpf.c
> +++ b/lib/test_bpf.c
> @@ -356,6 +356,52 @@ static int bpf_fill_maxinsns11(struct bpf_test *self)
>         return __bpf_fill_ja(self, BPF_MAXINSNS, 68);
>  }
>
> +static int bpf_fill_maxinsns12(struct bpf_test *self)
> +{
> +       unsigned int len = BPF_MAXINSNS;
> +       struct sock_filter *insn;
> +       int i = 0;
> +
> +       insn = kmalloc_array(len, sizeof(*insn), GFP_KERNEL);
> +       if (!insn)
> +               return -ENOMEM;
> +
> +       insn[0] = __BPF_JUMP(BPF_JMP | BPF_JA, len - 2, 0, 0);
> +
> +       for (i = 1; i < len - 1; i++)
> +               insn[i] = __BPF_STMT(BPF_LDX | BPF_B | BPF_MSH, 0);
> +
> +       insn[len - 1] = __BPF_STMT(BPF_RET | BPF_K, 0xabababab);
> +
> +       self->u.ptr.insns = insn;
> +       self->u.ptr.len = len;
> +
> +       return 0;
> +}
> +
> +static int bpf_fill_maxinsns13(struct bpf_test *self)
> +{
> +       unsigned int len = BPF_MAXINSNS;
> +       struct sock_filter *insn;
> +       int i = 0;
> +
> +       insn = kmalloc_array(len, sizeof(*insn), GFP_KERNEL);
> +       if (!insn)
> +               return -ENOMEM;
> +
> +       for (i = 0; i < len - 3; i++)
> +               insn[i] = __BPF_STMT(BPF_LDX | BPF_B | BPF_MSH, 0);
> +
> +       insn[len - 3] = __BPF_STMT(BPF_LD | BPF_IMM, 0xabababab);
> +       insn[len - 2] = __BPF_STMT(BPF_ALU | BPF_XOR | BPF_X, 0);
> +       insn[len - 1] = __BPF_STMT(BPF_RET | BPF_A, 0);
> +
> +       self->u.ptr.insns = insn;
> +       self->u.ptr.len = len;
> +
> +       return 0;
> +}
> +
>  static int bpf_fill_ja(struct bpf_test *self)
>  {
>         /* Hits exactly 11 passes on x86_64 JIT. */
> @@ -5290,6 +5336,23 @@ static struct bpf_test tests[] = {
>                 .expected_errcode = -ENOTSUPP,
>         },
>         {
> +               "BPF_MAXINSNS: jump over MSH",
> +               { },
> +               CLASSIC | FLAG_EXPECTED_FAIL,
> +               { 0xfa, 0xfb, 0xfc, 0xfd, },
> +               { { 4, 0xabababab } },
> +               .fill_helper = bpf_fill_maxinsns12,
> +               .expected_errcode = -EINVAL,
> +       },
> +       {
> +               "BPF_MAXINSNS: exec all MSH",
> +               { },
> +               CLASSIC,
> +               { 0xfa, 0xfb, 0xfc, 0xfd, },
> +               { { 4, 0xababab83 } },
> +               .fill_helper = bpf_fill_maxinsns13,
> +       },
> +       {
>                 "BPF_MAXINSNS: ld_abs+get_processor_id",
>                 { },
>                 CLASSIC,
> --
> 2.9.5
>