Re: [PATCH bpf-next] libbpf: Fix include of bpf_helpers.h when libbpf is installed on system

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

On Tue, Jan 14, 2020 at 11:07 AM Andrii Nakryiko
<andrii.nakryiko@gmail.com> wrote:
>
> On Tue, Jan 14, 2020 at 8:43 AM Toke Høiland-Jørgensen <toke@redhat.com> wrote:
> >
> > The change to use angled includes for bpf_helper_defs.h breaks compilation
> > against libbpf when it is installed in the include path, since the file is
> > installed in the bpf/ subdirectory of $INCLUDE_PATH. Fix this by adding the
> > bpf/ prefix to the #include directive.
> >
> > Fixes: 6910d7d3867a ("selftests/bpf: Ensure bpf_helper_defs.h are taken from selftests dir")
> > Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
> > ---
> > Not actually sure this fix works for all the cases you originally tried to
>
> This does break selftests/bpf. Have you tried building selftests, does
> it work for you? We need to fix selftests simultaneously with this
> change.
>
> > fix with the referred commit; please check. Also, could we please stop breaking
> > libbpf builds? :)
>
> Which libbpf build is failing right now? Both github and in-kernel
> libbpf builds are fine. You must be referring to something else. What
> exactly?

I think it's better to just ensure that when compiling BPF programs,
they have -I/usr/include/bpf specified, so that all BPF-side headers
can be simply included as #include <bpf_helpers.h>, #include
<bpf_tracing.h>, etc

>
> >
> >  tools/lib/bpf/bpf_helpers.h | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/tools/lib/bpf/bpf_helpers.h b/tools/lib/bpf/bpf_helpers.h
> > index 050bb7bf5be6..fa43d649e7a2 100644
> > --- a/tools/lib/bpf/bpf_helpers.h
> > +++ b/tools/lib/bpf/bpf_helpers.h
> > @@ -2,7 +2,7 @@
> >  #ifndef __BPF_HELPERS__
> >  #define __BPF_HELPERS__
> >
> > -#include <bpf_helper_defs.h>
> > +#include <bpf/bpf_helper_defs.h>
> >
> >  #define __uint(name, val) int (*name)[val]
> >  #define __type(name, val) typeof(val) *name
> > --
> > 2.24.1
> >