Messages in this thread | | | Date | Wed, 4 Oct 2017 23:08:04 +0900 | From | Masami Hiramatsu <> | Subject | Re: [BUGFIX PATCH] kprobes/x86: Remove IRQ disabling from jprobe handlers |
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On Wed, 4 Oct 2017 12:41:01 +0200 Ingo Molnar <mingo@kernel.org> wrote:
> > * Masami Hiramatsu <mhiramat@kernel.org> wrote: > > > Hmm, actually we can not disable jprobe, that has no separate Kconfig. > > So we need to introduce new kconfig for that. > > > > And, there are several network protocols using jprobe to trace events. > > (e.g. NET_DCCPPROBE and NET_TCPPROBE) > > I think they need to migrate to trace-event at first. > > > > So, how about below idea? > > > > 1. Introduce CONFIG_JPROBE_API which only separate jprobe general parts > > (no arch dependent code involves) and make it default n. > > 2. Mark break_handler and jprobe APIs deprecated so that no new user comes up. > > 3. migrate in-kernel jprobe user to trace-event or ftrace. > > (may take some time) > > So my suggestion would be to just return from register_jprobe() and don't register > anything.
with CONFIG_JPROBE_API=n, is that right?
> Yes, there are usecases of jprobes in the kernel, but they all look > pretty ancient and unused.
Hmm, in that case, should we also remove those users? If we disable such way those features are just useless.
> > So let's try this for -next and see whether anyone has a real usecase. And no > Kconfig and deprecation messages - those don't really work in practice - just > disable the functionality and force people to (trivially) modify the source if > they want to re-enable it.
So you mean I don't have to change those usecases, just let them do.
> > If this is fine for a single release then we can just remove it all: > > > 4. after that, we can completely remove jprobe which will be a series for > > all archs. (or just one big patch?) > > we want a series of patches - but that's for later.
OK :)
Thank you,
> > Thanks, > > Ingo
-- Masami Hiramatsu <mhiramat@kernel.org>
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