On Thu, 14 Jul 2022 at 07:38, Andrii Nakryiko <andrii.nakryiko@xxxxxxxxx> wrote:
>
> On Wed, Jul 13, 2022 at 4:15 AM Toke Høiland-Jørgensen <toke@xxxxxxxxxx> wrote:
> >
> > From: Kumar Kartikeya Dwivedi <memxor@xxxxxxxxx>
> >
> > Test various cases of direct packet access (proper range propagation,
> > comparison of packet pointers pointing into separate xdp_frames, and
> > correct invalidation on packet drop (so that multiple packet pointers
> > are usable safely in a dequeue program)).
> >
> > Signed-off-by: Kumar Kartikeya Dwivedi <memxor@xxxxxxxxx>
> > Signed-off-by: Toke Høiland-Jørgensen <toke@xxxxxxxxxx>
> > ---
>
> Consider writing these tests as plain C BPF code and put them in
> test_progs, is there anything you can't express in C and thus requires
> test_verifier?
Not really, but in general I like test_verifier because it stays
immune to compiler shenanigans.
So going forward should test_verifier tests be avoided, and normal C
tests (using SEC("?...")) be preferred for these cases?
>
> > tools/testing/selftests/bpf/test_verifier.c | 29 +++-
> > .../testing/selftests/bpf/verifier/dequeue.c | 160 ++++++++++++++++++
> > 2 files changed, 180 insertions(+), 9 deletions(-)
> > create mode 100644 tools/testing/selftests/bpf/verifier/dequeue.c
> >
>
> [...]
