On Tue, Sep 2, 2025 at 11:35 PM Jiri Olsa <olsaj...@gmail.com> wrote:
>
> On Tue, Sep 02, 2025 at 09:11:22AM -0700, Alexei Starovoitov wrote:
> > On Tue, Sep 2, 2025 at 7:38 AM Jiri Olsa <jo...@kernel.org> wrote:
> > >
> > > Adding support to attach unique uprobe through uprobe multi link
> > > interface.
> > >
> > > Adding new BPF_F_UPROBE_MULTI_UNIQUE flag that denotes the unique
> > > uprobe creation.
> > >
> > > Signed-off-by: Jiri Olsa <jo...@kernel.org>
> > > ---
> > > include/uapi/linux/bpf.h | 3 ++-
> > > kernel/trace/bpf_trace.c | 4 +++-
> > > tools/include/uapi/linux/bpf.h | 3 ++-
> > > 3 files changed, 7 insertions(+), 3 deletions(-)
> > >
> > > diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
> > > index 233de8677382..3de9eb469fe2 100644
> > > --- a/include/uapi/linux/bpf.h
> > > +++ b/include/uapi/linux/bpf.h
> > > @@ -1300,7 +1300,8 @@ enum {
> > > * BPF_TRACE_UPROBE_MULTI attach type to create return probe.
> > > */
> > > enum {
> > > - BPF_F_UPROBE_MULTI_RETURN = (1U << 0)
> > > + BPF_F_UPROBE_MULTI_RETURN = (1U << 0),
> > > + BPF_F_UPROBE_MULTI_UNIQUE = (1U << 1),
> >
> > I second Masami's point. "exclusive" name fits better.
> > And once you use that name the "multi_exclusive"
> > part will not make sense.
> > How can an exclusive user of the uprobe be "multi" at the same time?
> > Like attaching to multiple uprobes and modifying regsiters
> > in all of them? Is it practical ?
>
> we can still attach single uprobe with uprobe_multi,
> but for more uprobes it's probably not practical
>
> > It till attach single uprobe with eels to me BPF_F_UPROBE_EXCLUSIVE should
> > be targeting
> > one specific uprobe.
>
> do you mean to force single uprobe with this flag?
>
> I understood 'BPF_F_UPROBE_MULTI_' flag prefix more as indication what link
> it belongs to, but I'm ok with BPF_F_UPROBE_EXCLUSIVE
What is the use case for attaching the same bpf prog to multiple
uprobes and modifying their registers?
