Re: Error loading xdp program that worked with bpf_load

I am using libbpf from here https://github.com/libbpf/libbpf I'm not
using ebpf. I just linked to the ebpf issue because it seems like the
only thing related to this problem when I googled it.

On Thu, Jun 11, 2020 at 9:34 AM Andrii Nakryiko
<[email protected]> wrote:
>
> On Thu, Jun 11, 2020 at 4:00 AM Jesper Dangaard Brouer
> <[email protected]> wrote:
> >
> > (Cross-posting to iovisor-dev)
> >
> > Seeking input from BPF-llvm developers. How come Clang/LLVM 10+ is
> > generating incompatible BTF-info in ELF file, and downgrading to LLVM-9
> > fixes the issue ?
> >
> >
> > On Wed, 10 Jun 2020 14:50:27 -0700 Elerion <[email protected]> wrote:
> >
> > > Never mind, I fixed it by downgrading to Clang 9.
> > >
> > > It appears to be an issue with Clang/LLVM 10+
> > >
> > > https://github.com/cilium/ebpf/issues/43
>
> This is newer Clang recording that function is global, not static.
> libbpf is sanitizing BTF to remove this flag, if kernel doesn't
> support this. But given this is re-implementation of libbpf, that's
> probably not happening, right?
>
> > >
> > > On Wed, Jun 10, 2020 at 2:38 PM Toke Høiland-Jørgensen <[email protected]> wrote:
> > > >
> > > > Elerion <[email protected]> writes:
> > > >
> > > > > [69] FUNC xdp_program type_id=68 vlen != 0
> > > >
> > > > 'vlen != 0' is the error. Not sure why you hit that; what's the output
> > > > of 'bpftool btf dump file yourprog.o' ?
> > > >
> > > > -Toke
> > > >
> >
> >
> > --
> > Best regards,
> >   Jesper Dangaard Brouer
> >   MSc.CS, Principal Kernel Engineer at Red Hat
> >   LinkedIn: http://www.linkedin.com/in/brouer
> >