On Wed, 2023-02-08 at 17:34 -0800, Andrii Nakryiko wrote:
> On Wed, Feb 8, 2023 at 12:57 PM Ilya Leoshkevich <iii@xxxxxxxxxxxxx>
> wrote:
> >
> > eBPF selftests produce a few false positives with MSan. These can
> > be
> > divided in two classes:
> >
> > - Sending uninitalized data via a socket.
> > - bpf_obj_get_info_by_fd() calls.
> >
> > The first class is trivial; the second should ideally be handled by
> > libbpf, but it doesn't look possible at the moment, since we don't
> > know the type of the eBPF object referred to by fd, and therefore
> > the
> > structure of the output data.
>
> yeah, bpf_obj_get_info_by_fd() is quite bad from usability
> standpoint.
> I think we should add bpf_get_{map,prog,link,btf}_info_by_fd()
> wrappers and try to use them. That will allow to specify correct
> expected struct types, we'll be able to mark initialized memory
> properly. We already have bpf_{map,prog,btf,link}_get_fd_by_id()
> family, so having similar for getting info seems fitting (even if
> underlying bpf() command is generic).
>
> Thoughts?
Sounds good to me, I will give it a try.
> >
> > Signed-off-by: Ilya Leoshkevich <iii@xxxxxxxxxxxxx>
> > ---
> > tools/testing/selftests/bpf/cap_helpers.c | 3 +++
> > tools/testing/selftests/bpf/prog_tests/bpf_obj_id.c | 10
> > ++++++++++
> > tools/testing/selftests/bpf/prog_tests/bpf_tcp_ca.c | 3 +++
> > tools/testing/selftests/bpf/prog_tests/btf.c | 11
> > +++++++++++
> > tools/testing/selftests/bpf/prog_tests/send_signal.c | 2 ++
> > .../selftests/bpf/prog_tests/tp_attach_query.c | 6 ++++++
> > tools/testing/selftests/bpf/prog_tests/xdp_bonding.c | 3 +++
> > tools/testing/selftests/bpf/xdp_synproxy.c | 2 ++
> > 8 files changed, 40 insertions(+)
> >
>
> [...]
