On Tue, May 06, 2025 at 03:33:33PM -0700, Andrii Nakryiko wrote:
> On Tue, May 6, 2025 at 6:58 AM Jiri Olsa <jolsa@xxxxxxxxxx> wrote:
> >
> > Adding support to display ref_ctr_offset in link output, like:
> >
> > # bpftool link
> > ...
> > 42: perf_event prog 174
> > uprobe /proc/self/exe+0x102f13 cookie 3735928559 ref_ctr_offset 50500538
>
> let's use hex for ref_ctr_offset?
I had that, then I saw cookie was dec ;-) either way is fine for me
>
> and also, why do we have bpf_cookie and cookie emitted? Are they different?
hum, right.. so there's bpf_cookie retrieval from perf_link through the
task_file iterator:
cbdaf71f7e65 bpftool: Add bpf_cookie to link output
I guess it was added before we decided to have bpf_link_info.perf_event
interface, which seems easier to me
jirka
>
> > bpf_cookie 3735928559
> > pids test_progs(1820)
> >
> > # bpftool link -j | jq
> > [
> > ...
> > {
> > "id": 42,
> > ...
> > "ref_ctr_offset": 50500538,
> > }
> > ]
> >
> > Signed-off-by: Jiri Olsa <jolsa@xxxxxxxxxx>
> > ---
> > tools/bpf/bpftool/link.c | 3 +++
> > 1 file changed, 3 insertions(+)
> >
> > diff --git a/tools/bpf/bpftool/link.c b/tools/bpf/bpftool/link.c
> > index 52fd2c9fac56..b09aae3a191e 100644
> > --- a/tools/bpf/bpftool/link.c
> > +++ b/tools/bpf/bpftool/link.c
> > @@ -380,6 +380,7 @@ show_perf_event_uprobe_json(struct bpf_link_info *info, json_writer_t *wtr)
> > u64_to_ptr(info->perf_event.uprobe.file_name));
> > jsonw_uint_field(wtr, "offset", info->perf_event.uprobe.offset);
> > jsonw_uint_field(wtr, "cookie", info->perf_event.uprobe.cookie);
> > + jsonw_uint_field(wtr, "ref_ctr_offset", info->perf_event.uprobe.ref_ctr_offset);
> > }
> >
> > static void
> > @@ -823,6 +824,8 @@ static void show_perf_event_uprobe_plain(struct bpf_link_info *info)
> > printf("%s+%#x ", buf, info->perf_event.uprobe.offset);
> > if (info->perf_event.uprobe.cookie)
> > printf("cookie %llu ", info->perf_event.uprobe.cookie);
> > + if (info->perf_event.uprobe.ref_ctr_offset)
> > + printf("ref_ctr_offset %llu ", info->perf_event.uprobe.ref_ctr_offset);
> > }
> >
> > static void show_perf_event_tracepoint_plain(struct bpf_link_info *info)
> > --
> > 2.49.0
> >
