On Mon, Nov 28, 2022 at 5:30 AM Jiri Olsa <jolsa@xxxxxxxxxx> wrote:
>
> Adding tests for using new bpf_vma_build_id_parse kfunc in task_vma
> iterator program.
>
> On bpf program side the iterator filters test proccess and proper
> vma by provided function pointer and reads its build id with the
> new kfunc.
>
> On user side the test uses readelf to get test_progs build id and
> compares it with the one read from iterator.
>
> Signed-off-by: Jiri Olsa <jolsa@xxxxxxxxxx>
> ---
> .../selftests/bpf/prog_tests/bpf_iter.c | 44 +++++++++++++++++++
> .../selftests/bpf/progs/bpf_iter_build_id.c | 41 +++++++++++++++++
> 2 files changed, 85 insertions(+)
> create mode 100644 tools/testing/selftests/bpf/progs/bpf_iter_build_id.c
>
> diff --git a/tools/testing/selftests/bpf/prog_tests/bpf_iter.c b/tools/testing/selftests/bpf/prog_tests/bpf_iter.c
> index 6f8ed61fc4b4..b2cad9f70b32 100644
> --- a/tools/testing/selftests/bpf/prog_tests/bpf_iter.c
> +++ b/tools/testing/selftests/bpf/prog_tests/bpf_iter.c
> @@ -33,6 +33,9 @@
<...>
>
> +static void test_task_vma_build_id(void)
> +{
> + struct bpf_iter_build_id *skel;
> + char buf[BUILDID_STR_SIZE] = {};
Jiri, do you mean buf[BUILDID_STR_SIZE + 1]? I see you have
buf[BUILDID_STR_SIZE] = 0; below.
> + int iter_fd, len;
> + char *build_id;
<...>
> +
> + while ((len = read(iter_fd, buf, sizeof(buf))) > 0)
> + ;
I think you need to pass 'buf + len' to read(), otherwise the last
iteration will overwrite the content read from the previous
iterations.
> + buf[BUILDID_STR_SIZE] = 0;
> +
> + /* Read build_id via readelf to compare with iterator buf. */
> + if (!ASSERT_OK(read_self_buildid(&build_id), "read_buildid"))
> + goto exit;
We need to close iter_fd before going to exit.
> +
> + ASSERT_STREQ(buf, build_id, "build_id_match");
> + ASSERT_GT(skel->data->size, 0, "size");
> +
> + free(build_id);
> + close(iter_fd);
> +exit:
> + bpf_iter_build_id__destroy(skel);
> +}
> +
<...>
> --
> 2.38.1
>
