Re: [BUG] no ORC stacktrace from kretprobe.multi bpf program

[Jiri Olsa <olsajiri@gmail.com>]

On Sun, Oct 12, 2025 at 01:09:31PM +0900, Masami Hiramatsu wrote:
> On Wed, 8 Oct 2025 23:08:26 +0200
> Jiri Olsa <olsajiri@gmail.com> wrote:
> 
> > hi,
> > I'm getting no stacktrace from bpf program attached on kretprobe.multi probe
> > (which means on top of return fprobe) on x86.
> > 
> > I think we need some kind of treatment we do for rethook, AFAICS the ORC unwind
> > stops on return_to_handler, because the stack and the function itself are not
> > adjusted for unwind_recover_ret_addr call
> > 
> > If it's any help I pushed the bpf/selftest for that in here:
> >   https://git.kernel.org/pub/scm/linux/kernel/git/jolsa/perf.git/log/?h=stacktrace_test
> > 
> > just execute:
> >   # test_progs -t stacktrace_map/kretprobe_multi
> 
> Hmm, curious. as far as we are using fgraph, stacktrace should work.
> May this happen if function-graph tracer is enabled too?

that tests is just simple kretprobe so there should be no function-graph
tracer in the way.. I plan to check on this again later this week

jirka