Re: a small question about bpftool struct_ops

[Zhouyi Zhou]

Hi

On Sat, May 20, 2023 at 7:37 AM Zhouyi Zhou <zhouzhouyi@xxxxxxxxx> wrote:
>
> Thank you for responding so quickly ;-)
>
> On Sat, May 20, 2023 at 3:01 AM Martin KaFai Lau <martin.lau@xxxxxxxxx> wrote:
> >
> > On 5/19/23 5:07 AM, Zhouyi Zhou wrote:
> > > Dear developers:
> > > I compiled bpftool and bpf tests in mainline (2d1bcbc6cd70),
> > > but when I invoke:
> > > bpftool struct_ops register bpf_cubic.bpf.o
> > >
> > > the command line fail with:
> > > libbpf: struct_ops init_kern: struct tcp_congestion_ops data is not
> > > found in struct bpf_struct_ops_tcp_congestion_ops
> >
> > At the machine trying to register the bpf_cubic, please dump the vmlinux btf and
> > search for bpf_struct_ops_tcp_congestion_ops and paste it here:
> >
> > For example:
> > #> bpftool btf dump file /sys/kernel/btf/vmlinux
> >
> > ...
> >
> > [74578] STRUCT 'bpf_struct_ops_tcp_congestion_ops' size=256 vlen=3
> >          'refcnt' type_id=145 bits_offset=0
> >          'state' type_id=74569 bits_offset=32
> >          'data' type_id=6241 bits_offset=512
> OK
> [214398] STRUCT 'bpf_struct_ops_tcp_congestion_ops' size=256 vlen=3
>         'refcnt' type_id=298 bits_offset=0
>         'state' type_id=214224 bits_offset=32
>         'data' type_id=213704 bits_offset=512
>
> Please tell me if I could provide any further information.
>
> You are of great help
>
> Thank you very much
> Zhouyi
Thanks for your help

Or, can you teach me how to prepare an environment that can run
"bpftool struct_ops register xxx.o" ;-)
(A few words of description of OS version (Ubuntu/CentOS/Suse for etc)
and example kernel .config is enough)

I am an enthusiastic learner ;-)

Thanks in advance
Zhouyi
> >