diff mbox series

[1/2] selftests/bpf: Avoid errno clobbering

Message ID 20201128192502.88195-2-dev@der-flo.net (mailing list archive)
State Superseded
Delegated to: BPF
Headers show
Series Improve error handling of verifier tests | expand

Checks

Context Check Description
netdev/tree_selection success Not a local patch

Commit Message

Florian Lehner Nov. 28, 2020, 7:25 p.m. UTC
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@google.com>
Cc: Krzesimir Nowak <krzesimir@kinvolk.io>
Signed-off-by: Florian Lehner <dev@der-flo.net>
---
 tools/testing/selftests/bpf/test_verifier.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

Comments

Andrii Nakryiko Dec. 2, 2020, 1:24 a.m. UTC | #1
On Sat, Nov 28, 2020 at 11:28 AM Florian Lehner <dev@der-flo.net> 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@google.com>
> Cc: Krzesimir Nowak <krzesimir@kinvolk.io>
> Signed-off-by: Florian Lehner <dev@der-flo.net>
> ---

Acked-by: Andrii Nakryiko <andrii@kernel.org>

>  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
>
diff mbox series

Patch

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