Re: [RFC PATCH v2 0/8] fprobe: Introduce fprobe function entry/exit probe

Masami Hiramatsu
2022-01-13T13:18:54Z

On Thu, 13 Jan 2022 13:27:34 +0100
Jiri Olsa <jolsa@redhat.com> wrote:

> On Wed, Jan 12, 2022 at 05:01:15PM +0100, Jiri Olsa wrote:
> > On Wed, Jan 12, 2022 at 11:02:46PM +0900, Masami Hiramatsu wrote:
> > > Hi Jiri and Alexei,
> > >
> > > Here is the 2nd version of fprobe. This version uses the
> > > ftrace_set_filter_ips() for reducing the registering overhead.
> > > Note that this also drops per-probe point private data, which
> > > is not used anyway.
> > >
> > > This introduces the fprobe, the function entry/exit probe with
> > > multiple probe point support. This also introduces the rethook
> > > for hooking function return as same as kretprobe does. This
> >
> > nice, I was going through the multi-user-graph support
> > and was wondering that this might be a better way
> >
> > > abstraction will help us to generalize the fgraph tracer,
> > > because we can just switch it from rethook in fprobe, depending
> > > on the kernel configuration.
> > >
> > > The patch [1/8] and [7/8] are from your series[1]. Other libbpf
> > > patches will not be affected by this change.
> >
> > I'll try the bpf selftests on top of this
>
> I'm getting crash and stall when running bpf selftests,
> the fprobe sample module works fine, I'll check on that

Hmm, would you mean tools/testing/selftests/bpf/prog_tests/ ?
Let me check it too.

Thank you,

--
Masami Hiramatsu <mhiramat@kernel.org>