Re: [PATCH bpf-next v4 2/2] bpf: Add show_fdinfo for kprobe_multi

[Tao Chen]

在 2025/6/20 10:59, Alexei Starovoitov 写道:
> On Thu, Jun 19, 2025 at 7:46 PM Tao Chen <chen.dylane@xxxxxxxxx> wrote:
> > 在 2025/6/20 01:17, Alexei Starovoitov 写道:
> > > On Wed, Jun 18, 2025 at 8:44 PM Tao Chen <chen.dylane@xxxxxxxxx> wrote:
> > > > Show kprobe_multi link info with fdinfo, the info as follows:
> > > >
> > > > link_type:      kprobe_multi
> > > > link_id:        1
> > > > prog_tag:       a15b7646cb7f3322
> > > > prog_id:        21
> > > > type:   kprobe_multi
> > >
> > > ..
> > >
> > > > +       seq_printf(seq,
> > > > +                  "type:\t%s\n"
> > > > +                  "kprobe_cnt:\t%u\n"
> > > > +                  "missed:\t%lu\n",
> > > > +                  kmulti_link->flags == BPF_F_KPROBE_MULTI_RETURN ? "kretprobe_multi" :
> > > > +                                        "kprobe_multi",
> > >
> > > why print the same info twice ?
> > > seq_printf(m, "link_type:\t%s\n", bpf_link_type_strs[type]);
> > > in bpf_link_show_fdinfo() already did it in a cleaner way.
> >
> > link_type only shows 'kprobe_multi', maybe we can show the format like:
>
> Ohh. Especially so. It would be wrong and confusing to display:
> link_type:      kprobe_multi
> type: kretprobe_multi
>
> Let's fix 'link_type' to display it properly.

What do you think show like this:

    link_type:      kprobe_multi
    link_id:        1
    prog_tag:       33be53a4fd673e1d
    prog_id:        21
    retprobe:       false
    kprobe_cnt:     8
    missed: 0
    cookie           func
    1                bpf_fentry_test1+0x0/0x20
    7                bpf_fentry_test2+0x0/0x20
    2                bpf_fentry_test3+0x0/0x20
    3                bpf_fentry_test4+0x0/0x20
    4                bpf_fentry_test5+0x0/0x20
    5                bpf_fentry_test6+0x0/0x20
    6                bpf_fentry_test7+0x0/0x20
    8                bpf_fentry_test8+0x0/0x10

--
Best Regards
Tao Chen