On Fri, Nov 16, 2018 at 12:55 PM Lorenz Bauer <lmb@xxxxxxxxxxxxxx> wrote:
>
> Make sure that bpf_prog_test_run returns the correct length
> in the size_out argument and that the kernel respects the
> output size hint.
>
> Signed-off-by: Lorenz Bauer <lmb@xxxxxxxxxxxxxx>
> ---
> tools/testing/selftests/bpf/test_progs.c | 34 ++++++++++++++++++++++++
> 1 file changed, 34 insertions(+)
>
> diff --git a/tools/testing/selftests/bpf/test_progs.c b/tools/testing/selftests/bpf/test_progs.c
> index 560d7527b86b..6ab98e10e86f 100644
> --- a/tools/testing/selftests/bpf/test_progs.c
> +++ b/tools/testing/selftests/bpf/test_progs.c
> @@ -124,6 +124,39 @@ static void test_pkt_access(void)
> bpf_object__close(obj);
> }
>
> +static void test_output_size_hint(void)
> +{
> + const char *file = "./test_pkt_access.o";
> + struct bpf_object *obj;
> + __u32 retval, size, duration;
> + int err, prog_fd;
> + char buf[10];
> +
> + err = bpf_prog_load(file, BPF_PROG_TYPE_SCHED_CLS, &obj, &prog_fd);
> + if (err) {
> + error_cnt++;
> + return;
> + }
CHECK can also be used here.
if (CHECK(...)) {
goto done;
}
where label "done" is right before bpf_object__close.
> +
> + memset(buf, 0, sizeof(buf));
> +
> + size = 5;
> + err = bpf_prog_test_run(prog_fd, 1, &pkt_v4, sizeof(pkt_v4),
> + buf, &size, &retval, &duration);
> + CHECK(err || retval, "run",
> + "err %d errno %d retval %d\n",
> + err, errno, retval);
> +
> + CHECK(size != sizeof(pkt_v4), "out_size",
> + "incorrect output size, want %lu have %u\n",
> + sizeof(pkt_v4), size);
> +
> + CHECK(buf[5] != 0, "overflow",
> + "prog_test_run ignored size hint\n");
> +
> + bpf_object__close(obj);
> +}
> +
> static void test_xdp(void)
> {
> struct vip key4 = {.protocol = 6, .family = AF_INET};
> @@ -1847,6 +1880,7 @@ int main(void)
> jit_enabled = is_jit_enabled();
>
> test_pkt_access();
> + test_output_size_hint();
> test_xdp();
> test_xdp_adjust_tail();
> test_l4lb_all();
> --
> 2.17.1
>
