On Sat, Nov 28, 2020 at 11:28 AM Florian Lehner <dev@xxxxxxxxxxx> wrote:
>
> Commit 8184d44c9a57 ("selftests/bpf: skip verifier tests for unsupported
> program types") added a check to skip unsupported program types. As
> bpf_probe_prog_type can change errno, do_single_test should save it before
> printing a reason why a supported BPF program type failed to load.
>
> Fixes: 8184d44c9a57 ("selftests/bpf: skip verifier tests for unsupported program types")
> Cc: Stanislav Fomichev <sdf@xxxxxxxxxx>
> Cc: Krzesimir Nowak <krzesimir@xxxxxxxxxx>
> Signed-off-by: Florian Lehner <dev@xxxxxxxxxxx>
> ---
Acked-by: Andrii Nakryiko <andrii@xxxxxxxxxx>
> tools/testing/selftests/bpf/test_verifier.c | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/tools/testing/selftests/bpf/test_verifier.c b/tools/testing/selftests/bpf/test_verifier.c
> index 4bfe3aa2cfc4..ceea9409639e 100644
> --- a/tools/testing/selftests/bpf/test_verifier.c
> +++ b/tools/testing/selftests/bpf/test_verifier.c
> @@ -936,6 +936,7 @@ static void do_test_single(struct bpf_test *test, bool unpriv,
> int run_errs, run_successes;
> int map_fds[MAX_NR_MAPS];
> const char *expected_err;
> + int saved_errno;
> int fixup_skips;
> __u32 pflags;
> int i, err;
> @@ -997,6 +998,7 @@ static void do_test_single(struct bpf_test *test, bool unpriv,
> }
>
> fd_prog = bpf_load_program_xattr(&attr, bpf_vlog, sizeof(bpf_vlog));
> + saved_errno = errno;
>
> /* BPF_PROG_TYPE_TRACING requires more setup and
> * bpf_probe_prog_type won't give correct answer
> @@ -1013,7 +1015,7 @@ static void do_test_single(struct bpf_test *test, bool unpriv,
> if (expected_ret == ACCEPT || expected_ret == VERBOSE_ACCEPT) {
> if (fd_prog < 0) {
> printf("FAIL\nFailed to load prog '%s'!\n",
> - strerror(errno));
> + strerror(saved_errno));
> goto fail_log;
> }
> #ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
> --
> 2.28.0
>
