On Thu, Jun 22, 2023 at 7:00 AM Yonghong Song <yhs@xxxxxxxx> wrote:
>
>
>
> On 6/20/23 9:30 AM, Yafang Shao wrote:
> > By introducing support for ->fill_link_info to the perf_event link, users
> > gain the ability to inspect it using `bpftool link show`. While the current
> > approach involves accessing this information via `bpftool perf show`,
> > consolidating link information for all link types in one place offers
> > greater convenience. Additionally, this patch extends support to the
> > generic perf event, which is not currently accommodated by
> > `bpftool perf show`. While only the perf type and config are exposed to
> > userspace, other attributes such as sample_period and sample_freq are
> > ignored. It's important to note that if kptr_restrict is not permitted, the
> > probed address will not be exposed, maintaining security measures.
> >
> > A new enum bpf_perf_event_type is introduced to help the user understand
> > which struct is relevant.
> >
> > Signed-off-by: Yafang Shao <laoar.shao@xxxxxxxxx>
> > ---
> > include/uapi/linux/bpf.h | 36 +++++++++++++
> > kernel/bpf/syscall.c | 115 +++++++++++++++++++++++++++++++++++++++++
> > tools/include/uapi/linux/bpf.h | 36 +++++++++++++
> > 3 files changed, 187 insertions(+)
> >
> > diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
> > index 23691ea..56528dd 100644
> > --- a/include/uapi/linux/bpf.h
> > +++ b/include/uapi/linux/bpf.h
> > @@ -1056,6 +1056,16 @@ enum bpf_link_type {
> > MAX_BPF_LINK_TYPE,
> > };
> >
> > +enum bpf_perf_event_type {
> > + BPF_PERF_EVENT_UNSPEC = 0,
> > + BPF_PERF_EVENT_UPROBE = 1,
> > + BPF_PERF_EVENT_KPROBE = 2,
> > + BPF_PERF_EVENT_TRACEPOINT = 3,
> > + BPF_PERF_EVENT_EVENT = 4,
> > +
> > + MAX_BPF_PERF_EVENT_TYPE,
> > +};
> > +
> > /* cgroup-bpf attach flags used in BPF_PROG_ATTACH command
> > *
> > * NONE(default): No further bpf programs allowed in the subtree.
> > @@ -6443,6 +6453,32 @@ struct bpf_link_info {
> > __u32 count;
> > __u32 flags;
> > } kprobe_multi;
> > + struct {
> > + __u32 type; /* enum bpf_perf_event_type */
>
> Maybe add the following
> __u32 :32;
> so later on this field can be reused if another u32 is needed in
> the future?
Good point. Will do it.
--
Regards
Yafang
