Re: [PATCH bpf v1 2/3] selftests/bpf: Print a message when tester could not run a program

From: Krzesimir Nowak
Date: Thu May 16 2019 - 05:31:49 EST


On Wed, May 15, 2019 at 11:46 PM Jakub Kicinski
<jakub.kicinski@xxxxxxxxxxxxx> wrote:
>
> On Wed, 15 May 2019 15:47:27 +0200, Krzesimir Nowak wrote:
> > This prints a message when the error is about program type being not
> > supported by the test runner or because of permissions problem. This
> > is to see if the program we expected to run was actually executed.
> >
> > The messages are open-coded because strerror(ENOTSUPP) returns
> > "Unknown error 524".
> >
> > Signed-off-by: Krzesimir Nowak <krzesimir@xxxxxxxxxx>
> > ---
> > tools/testing/selftests/bpf/test_verifier.c | 17 +++++++++++++----
> > 1 file changed, 13 insertions(+), 4 deletions(-)
> >
> > diff --git a/tools/testing/selftests/bpf/test_verifier.c b/tools/testing/selftests/bpf/test_verifier.c
> > index ccd896b98cac..bf0da03f593b 100644
> > --- a/tools/testing/selftests/bpf/test_verifier.c
> > +++ b/tools/testing/selftests/bpf/test_verifier.c
> > @@ -825,11 +825,20 @@ static int do_prog_test_run(int fd_prog, bool unpriv, uint32_t expected_val,
> > tmp, &size_tmp, &retval, NULL);
> > if (unpriv)
> > set_admin(false);
> > - if (err && errno != 524/*ENOTSUPP*/ && errno != EPERM) {
> > - printf("Unexpected bpf_prog_test_run error ");
> > - return err;
> > + if (err) {
> > + switch (errno) {
> > + case 524/*ENOTSUPP*/:
> > + printf("Did not run the program (not supported) ");
> > + return 0;
> > + case EPERM:
> > + printf("Did not run the program (no permission) ");
> > + return 0;
>
> Perhaps use strerror(errno)?

As I said in the commit message, I open-coded those messages because
strerror for ENOTSUPP returns "Unknown error 524".

>
> > + default:
> > + printf("Unexpected bpf_prog_test_run error ");
> > + 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;
>


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