Re: [RFC PATCH bpf-next 2/4] selftests/bpf: Add re-attach test to fentry_test

[Jiri Olsa <jolsa@redhat.com>]

On Tue, Mar 30, 2021 at 01:23:15AM +0000, Song Liu wrote:
> 
> 
> > On Mar 28, 2021, at 4:26 AM, Jiri Olsa <jolsa@kernel.org> wrote:
> > 
> > Adding the test to re-attach (detach/attach again) tracing
> > fentry programs, plus check that already linked program can't
> > be attached again.
> > 
> > Fixing the number of check-ed results, which should be 8.
> > 
> > Signed-off-by: Jiri Olsa <jolsa@kernel.org>
> > 
> [...]
> > +
> > +void test_fentry_test(void)
> > +{
> > +	struct fentry_test *fentry_skel = NULL;
> > +	struct bpf_link *link;
> > +	int err;
> > +
> > +	fentry_skel = fentry_test__open_and_load();
> > +	if (CHECK(!fentry_skel, "fentry_skel_load", "fentry skeleton failed\n"))
> > +		goto cleanup;
> > +
> > +	err = fentry_test__attach(fentry_skel);
> > +	if (CHECK(err, "fentry_attach", "fentry attach failed: %d\n", err))
> > +		goto cleanup;
> > +
> > +	err = fentry_test(fentry_skel);
> > +	if (CHECK(err, "fentry_test", "fentry test failed: %d\n", err))
> > +		goto cleanup;
> > +
> > +	fentry_test__detach(fentry_skel);
> > +
> > +	/* Re-attach and test again */
> > +	err = fentry_test__attach(fentry_skel);
> > +	if (CHECK(err, "fentry_attach", "fentry re-attach failed: %d\n", err))
> > +		goto cleanup;
> > +
> > +	link = bpf_program__attach(fentry_skel->progs.test1);
> > +	if (CHECK(!IS_ERR(link), "attach_fentry re-attach without detach",
> > +		  "err: %ld\n", PTR_ERR(link)))
> 
> nit: I guess we shouldn't print PTR_ERR(link) when link is not an error code?
> This shouldn't break though. 

true, makes no sense.. I'll remove it

thanks,
jirka