Re: [PATCH bpf-next 2/2] selftests/bpf: add test for legacy/perf kprobe/uprobe attach mode

[Menglong Dong]

On Tue, Feb 7, 2023 at 4:05 AM Andrii Nakryiko
<andrii.nakryiko@xxxxxxxxx> wrote:
>
> On Thu, Feb 2, 2023 at 7:18 PM <menglong8.dong@xxxxxxxxx> wrote:
> >
> > From: Menglong Dong <imagedong@xxxxxxxxxxx>
> >
> > Add the testing for kprobe/uprobe attaching in legacy and perf mode.
> > And the testing passed:
> >
> > ./test_progs -t attach_probe
> > $5       attach_probe:OK
> > Summary: 1/0 PASSED, 0 SKIPPED, 0 FAILED
> >
> > Signed-off-by: Menglong Dong <imagedong@xxxxxxxxxxx>
> > ---
>
> Do you mind refactoring attach_probe test into multiple subtests,
> where each subtest will only test one of the attach mode and type. The
> reason is that libbpf CI runs tests with latest selftests and libbpf
> against old kernels (4.9 and 5.5, currently). Due to attach_probe
> testing all these uprobe/kprobe attach modes with extra features (like
> cookie, ref count, etc), we had to disable attach_probe test in libbpf
> CI on old kernels.
>
> If we can split each individual uprobe/kprobe mode, that will give us
> flexibility to selectively allowlist those tests that don't force
> libbpf to use newer features (like cookies, LINK or PERF mode, etc).
>
> It would be a great improvement and highly appreciated! If you don't
> mind doing this, let's do the split of existing use cases into subtest
> in a separate patch, and then add PERF/LEGACY/LINK mode tests on top
> of that patch.
>

Of course, with pleasure. For the existing use cases, we split it into
subtests, such as:

  kprobe/kretprobe auto attach
  kprobe/kretprobe manual attach
  uprobe/uretprobe ref_ctr test
  uprobe/uretprobe auto attach
  sleepable kprobe/uprobe
  ......

Am I right?

Thanks!
Dongmeng Long

>
> >  .../selftests/bpf/prog_tests/attach_probe.c   | 61 ++++++++++++++++++-
> >  .../selftests/bpf/progs/test_attach_probe.c   | 32 ++++++++++
> >  2 files changed, 92 insertions(+), 1 deletion(-)
> >
>
> [...]