diff mbox series

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

Message ID 20201202194532.12879-3-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State Superseded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 Dec. 2, 2020, 7:45 p.m. UTC
Print a message when the returned error is about a program type being
not supported or because of permission problems.
These messages are expected if the program to test was actually
executed.

Cc: Krzesimir Nowak <krzesimir@kinvolk.io>
Signed-off-by: Florian Lehner <dev@der-flo.net>
---
 tools/testing/selftests/bpf/test_verifier.c | 26 +++++++++++++++++----
 1 file changed, 21 insertions(+), 5 deletions(-)

--
2.28.0

Comments

Andrii Nakryiko Dec. 3, 2020, 9:13 p.m. UTC | #1
On Wed, Dec 2, 2020 at 11:46 AM Florian Lehner <dev@der-flo.net> wrote:
>
> Print a message when the returned error is about a program type being
> not supported or because of permission problems.
> These messages are expected if the program to test was actually
> executed.
>
> Cc: Krzesimir Nowak <krzesimir@kinvolk.io>
> Signed-off-by: Florian Lehner <dev@der-flo.net>
> ---
>  tools/testing/selftests/bpf/test_verifier.c | 26 +++++++++++++++++----
>  1 file changed, 21 insertions(+), 5 deletions(-)
>
> diff --git a/tools/testing/selftests/bpf/test_verifier.c b/tools/testing/selftests/bpf/test_verifier.c
> index ceea9409639e..86ef28dd9919 100644
> --- a/tools/testing/selftests/bpf/test_verifier.c
> +++ b/tools/testing/selftests/bpf/test_verifier.c
> @@ -875,19 +875,35 @@ static int do_prog_test_run(int fd_prog, bool unpriv, uint32_t expected_val,
>         __u8 tmp[TEST_DATA_LEN << 2];
>         __u32 size_tmp = sizeof(tmp);
>         uint32_t retval;
> -       int err;
> +       int err, saved_errno;
>
>         if (unpriv)
>                 set_admin(true);
>         err = bpf_prog_test_run(fd_prog, 1, data, size_data,
>                                 tmp, &size_tmp, &retval, NULL);
> +       saved_errno = errno;
> +
>         if (unpriv)
>                 set_admin(false);
> -       if (err && errno != 524/*ENOTSUPP*/ && errno != EPERM) {
> -               printf("Unexpected bpf_prog_test_run error ");
> -               return err;
> +
> +       if (err) {
> +               switch (saved_errno) {
> +               case 524/*ENOTSUPP*/:
> +                       printf("Did not run the program (not supported) ");
> +                       return 0;
> +               case EPERM:
> +                       if (unpriv) {
> +                               printf("Did not run the program (no permission) ");
> +                               return 0;
> +                       }

I see people specifying /* fallthrough; */ to make explicit that we
expect falling through into default case?

> +               default:
> +                       printf("FAIL: Unexpected bpf_prog_test_run error (%s) ",
> +                               strerror(saved_errno));
> +                       return err;
> +               }
>         }
> -       if (!err && retval != expected_val &&
> +
> +       if (retval != expected_val &&
>             expected_val != POINTER_VALUE) {
>                 printf("FAIL retval %d != %d ", retval, expected_val);
>                 return 1;
> --
> 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 ceea9409639e..86ef28dd9919 100644
--- a/tools/testing/selftests/bpf/test_verifier.c
+++ b/tools/testing/selftests/bpf/test_verifier.c
@@ -875,19 +875,35 @@  static int do_prog_test_run(int fd_prog, bool unpriv, uint32_t expected_val,
 	__u8 tmp[TEST_DATA_LEN << 2];
 	__u32 size_tmp = sizeof(tmp);
 	uint32_t retval;
-	int err;
+	int err, saved_errno;

 	if (unpriv)
 		set_admin(true);
 	err = bpf_prog_test_run(fd_prog, 1, data, size_data,
 				tmp, &size_tmp, &retval, NULL);
+	saved_errno = errno;
+
 	if (unpriv)
 		set_admin(false);
-	if (err && errno != 524/*ENOTSUPP*/ && errno != EPERM) {
-		printf("Unexpected bpf_prog_test_run error ");
-		return err;
+
+	if (err) {
+		switch (saved_errno) {
+		case 524/*ENOTSUPP*/:
+			printf("Did not run the program (not supported) ");
+			return 0;
+		case EPERM:
+			if (unpriv) {
+				printf("Did not run the program (no permission) ");
+				return 0;
+			}
+		default:
+			printf("FAIL: Unexpected bpf_prog_test_run error (%s) ",
+				strerror(saved_errno));
+			return err;
+		}
 	}
-	if (!err && retval != expected_val &&
+
+	if (retval != expected_val &&
 	    expected_val != POINTER_VALUE) {
 		printf("FAIL retval %d != %d ", retval, expected_val);
 		return 1;