Messages in this thread | | | Date | Sat, 30 Sep 2023 18:14:35 +0900 | From | Masami Hiramatsu (Google) <> | Subject | Re: [PATCH v5 00/12] tracing: fprobe: rethook: Use ftrace_regs instead of pt_regs |
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On Fri, 29 Sep 2023 17:12:07 -0700 Alexei Starovoitov <alexei.starovoitov@gmail.com> wrote:
> On Thu, Sep 28, 2023 at 6:21 PM Masami Hiramatsu <mhiramat@kernel.org> wrote: > > > > > > Thus, what I need is to make fprobe to use function-graph tracer's shadow > > stack and trampoline instead of rethook. This may need to generalize its > > interface so that we can share it between fprobe and function-graph tracer, > > but we don't need to involve rethook and kretprobes anymore. > > ... > > > And need to add patches > > > > - Introduce a generized function exit hook interface for ftrace. > > - Replace rethook in fprobe with the function exit hook interface. > > you mean that rethook will be removed after that?
No, it is too late. rethook is deeply integrated with kretprobe. So when we remove the kretprobe, rethook will be removed too. (fprobe and kretprobe provides similar functionality, so we can move to fprobe)
Even though, objpool(*) itself might be kept for some other use cases. As far as I can see, ftrace_ret_stack can not provide a context local storage between entry -> exit callbacks. (so this feature must be dropped from fprobe)
(*) https://lore.kernel.org/all/20230905015255.81545-1-wuqiang.matt@bytedance.com/
Thank you,
-- Masami Hiramatsu (Google) <mhiramat@kernel.org>
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