Re: [PATCH v2 bpf-next 1/9] selftests/bpf: normalize XDP section names in selftests

[Andrii Nakryiko <andrii.nakryiko@gmail.com>]

On Mon, Sep 20, 2021 at 9:55 PM Dave Marchevsky <davemarchevsky@fb.com> wrote:
>
> On 9/20/21 7:43 PM, Andrii Nakryiko wrote:
> > Convert almost all SEC("xdp_blah") uses to strict SEC("xdp") to comply
> > with strict libbpf 1.0 logic of exact section name match for XDP program
> > types. There is only one exception, which is only tested through
> > iproute2 and defines multiple XDP programs within the same BPF object.
> > Given iproute2 still works in non-strict libbpf mode and it doesn't have
> > means to specify XDP programs by its name (not section name/title),
> > leave that single file alone for now until iproute2 gains lookup by
> > function/program name.
> >
> > Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
> > ---
>
> Aside from a checkpatch nit which you didn't cause, LGTM. Some general
> comments follow as well, but aren't directly related to the patch.
>
> Acked-by: Dave Marchevsky <davemarchevsky@fb.com>
>
> >  tools/testing/selftests/bpf/progs/test_map_in_map.c         | 2 +-
> >  .../selftests/bpf/progs/test_tcp_check_syncookie_kern.c     | 2 +-
> >  tools/testing/selftests/bpf/progs/test_xdp.c                | 2 +-
> >  .../testing/selftests/bpf/progs/test_xdp_adjust_tail_grow.c | 2 +-
> >  .../selftests/bpf/progs/test_xdp_adjust_tail_shrink.c       | 4 +---
> >  tools/testing/selftests/bpf/progs/test_xdp_devmap_helpers.c | 2 +-
> >  tools/testing/selftests/bpf/progs/test_xdp_link.c           | 2 +-
> >  tools/testing/selftests/bpf/progs/test_xdp_loop.c           | 2 +-
> >  tools/testing/selftests/bpf/progs/test_xdp_noinline.c       | 4 ++--
> >  .../selftests/bpf/progs/test_xdp_with_cpumap_helpers.c      | 4 ++--
> >  .../selftests/bpf/progs/test_xdp_with_devmap_helpers.c      | 4 ++--
> >  tools/testing/selftests/bpf/progs/xdp_dummy.c               | 2 +-
> >  tools/testing/selftests/bpf/progs/xdp_redirect_multi_kern.c | 4 ++--
> >  tools/testing/selftests/bpf/progs/xdping_kern.c             | 4 ++--
> >  tools/testing/selftests/bpf/test_tcp_check_syncookie.sh     | 2 +-
> >  tools/testing/selftests/bpf/test_xdp_redirect.sh            | 4 ++--
> >  tools/testing/selftests/bpf/test_xdp_redirect_multi.sh      | 2 +-
> >  tools/testing/selftests/bpf/test_xdp_veth.sh                | 4 ++--
> >  tools/testing/selftests/bpf/xdping.c                        | 6 +++---
>
> Doesn't look like the test_...sh's here are run by the CI. Confirmed they
> (as well as test_xdping.sh) all passed for me. My test VM isn't doing anything
> special networking-wise, so maybe it's not too difficult to add these to CI.

Thanks for confirming. Yes, they are not run in CI, we only run
test_progs, test_verifier and test_maps. Instead of adding all those
small scripts to be run by CI, we are encouraging everyone to converge
on test_progs, because that's where we invest efforts to make it a
universal test runner for BPF needs. So I'd say let's convert them to
test_progs framework instead.

>
> >  19 files changed, 28 insertions(+), 30 deletions(-)
> >
> > diff --git a/tools/testing/selftests/bpf/progs/test_map_in_map.c b/tools/testing/selftests/bpf/progs/test_map_in_map.c
> > index 1cfeb940cf9f..5f0e0bfc151e 100644
> > --- a/tools/testing/selftests/bpf/progs/test_map_in_map.c
> > +++ b/tools/testing/selftests/bpf/progs/test_map_in_map.c
> > @@ -23,7 +23,7 @@ struct {

[...]

> >       void *data_end = (void *)(long)xdp->data_end;
> > diff --git a/tools/testing/selftests/bpf/progs/test_xdp_adjust_tail_shrink.c b/tools/testing/selftests/bpf/progs/test_xdp_adjust_tail_shrink.c
> > index 22065a9cfb25..b7448253d135 100644
> > --- a/tools/testing/selftests/bpf/progs/test_xdp_adjust_tail_shrink.c
> > +++ b/tools/testing/selftests/bpf/progs/test_xdp_adjust_tail_shrink.c
> > @@ -9,9 +9,7 @@
> >  #include <linux/if_ether.h>
> >  #include <bpf/bpf_helpers.h>
> >
> > -int _version SEC("version") = 1;
> > -
>
> Didn't realize this was meant to specify kernel version for compat, and that
> it no longer does anything anyways. Maybe this should be removed from all
> selftests + examples to make this more obvious?

Yes, it should, but perhaps in a separate clean up series. Except I'd
leave it for BPF static linker testing, of course.

>
> > -SEC("xdp_adjust_tail_shrink")
> > +SEC("xdp")
> >  int _xdp_adjust_tail_shrink(struct xdp_md *xdp)
> >  {
> >       void *data_end = (void *)(long)xdp->data_end;
> > diff --git a/tools/testing/selftests/bpf/progs/test_xdp_devmap_helpers.c b/tools/testing/selftests/bpf/progs/test_xdp_devmap_helpers.c
> > index b360ba2bd441..807bf895f42c 100644
> > --- a/tools/testing/selftests/bpf/progs/test_xdp_devmap_helpers.c

Note, it's generally a good idea to trim irrelevant parts in your
reply making it easier to see one's replies among the wall of text,
especially outside of gmail UI.

[...]

> > diff --git a/tools/testing/selftests/bpf/xdping.c b/tools/testing/selftests/bpf/xdping.c
> > index 842d9155d36c..f9798ead20a9 100644
> > --- a/tools/testing/selftests/bpf/xdping.c
> > +++ b/tools/testing/selftests/bpf/xdping.c
> > @@ -178,9 +178,9 @@ int main(int argc, char **argv)
> >               return 1;
> >       }
> >
> > -     main_prog = bpf_object__find_program_by_title(obj,
> > -                                                   server ? "xdpserver" :
> > -                                                            "xdpclient");
> > +     main_prog = bpf_object__find_program_by_name(obj,
> > +                                                   server ? "xdping_server" :
> > +                                                            "xdping_client");
>
> checkpatch doesn't like the text alignment here, not that you changed it

yeah, me neither, but not worth re-spin just for this :)

>
> >       if (main_prog)
> >               prog_fd = bpf_program__fd(main_prog);
> >       if (!main_prog || prog_fd < 0) {
> >
>
>