On Fri, Sep 30, 2022 at 4:09 AM Artem Savkov <asavkov@xxxxxxxxxx> wrote:
>
> At the moment libbpf_probe_prog_types test iterates over all available
> BPF_PROG_TYPE regardless of kernel configuration which can exclude some
> of those. Unfortunately there is no direct way to tell which types are
> available, but we can look at struct bpf_ctx_onvert to tell which ones
> are available.
>
> Signed-off-by: Artem Savkov <asavkov@xxxxxxxxxx>
> ---
Many selftests assume correct kernel configuration which is encoded in
config and config.<arch> files. So it seems fair to assume that all
defined program types are available on kernel-under-test.
If someone is running selftests under custom more minimal kernel they
can use denylist to ignore specific prog type subtests?
> .../selftests/bpf/prog_tests/libbpf_probes.c | 33 +++++++++++++++++--
> 1 file changed, 31 insertions(+), 2 deletions(-)
>
> diff --git a/tools/testing/selftests/bpf/prog_tests/libbpf_probes.c b/tools/testing/selftests/bpf/prog_tests/libbpf_probes.c
> index 9f766ddd946ab..753ddf79cf5e0 100644
> --- a/tools/testing/selftests/bpf/prog_tests/libbpf_probes.c
> +++ b/tools/testing/selftests/bpf/prog_tests/libbpf_probes.c
> @@ -4,12 +4,29 @@
> #include <test_progs.h>
> #include <bpf/btf.h>
>
> +static int find_type_in_ctx_convert(struct btf *btf,
> + const char *prog_type_name,
> + const struct btf_type *t)
> +{
> + const struct btf_member *m;
> + size_t cmplen = strlen(prog_type_name);
> + int i, n;
> +
> + for (m = btf_members(t), i = 0, n = btf_vlen(t); i < n; m++, i++) {
> + const char *member_name = btf__str_by_offset(btf, m->name_off);
> +
> + if (!strncmp(prog_type_name, member_name, cmplen))
> + return 1;
> + }
> + return 0;
> +}
> +
> void test_libbpf_probe_prog_types(void)
> {
> struct btf *btf;
> - const struct btf_type *t;
> + const struct btf_type *t, *context_convert_t;
> const struct btf_enum *e;
> - int i, n, id;
> + int i, n, id, context_convert_id;
>
> btf = btf__parse("/sys/kernel/btf/vmlinux", NULL);
> if (!ASSERT_OK_PTR(btf, "btf_parse"))
> @@ -23,6 +40,14 @@ void test_libbpf_probe_prog_types(void)
> if (!ASSERT_OK_PTR(t, "bpf_prog_type_enum"))
> goto cleanup;
>
> + context_convert_id = btf__find_by_name_kind(btf, "bpf_ctx_convert",
> + BTF_KIND_STRUCT);
> + if (!ASSERT_GT(context_convert_id, 0, "bpf_ctx_convert_id"))
> + goto cleanup;
> + context_convert_t = btf__type_by_id(btf, context_convert_id);
> + if (!ASSERT_OK_PTR(t, "bpf_ctx_convert_type"))
> + goto cleanup;
> +
> for (e = btf_enum(t), i = 0, n = btf_vlen(t); i < n; e++, i++) {
> const char *prog_type_name = btf__str_by_offset(btf, e->name_off);
> enum bpf_prog_type prog_type = (enum bpf_prog_type)e->val;
> @@ -31,6 +56,10 @@ void test_libbpf_probe_prog_types(void)
> if (prog_type == BPF_PROG_TYPE_UNSPEC)
> continue;
>
> + if (!find_type_in_ctx_convert(btf, prog_type_name,
> + context_convert_t))
> + continue;
> +
> if (!test__start_subtest(prog_type_name))
> continue;
>
> --
> 2.37.3
>
