Re: [PATCH bpf-next v2 0/4] kprobes: rethook: x86: Replace kretprobe trampoline with rethook

[Masami Hiramatsu <mhiramat@kernel.org>]

On Fri, 25 Mar 2022 09:49:47 -0700
Alexei Starovoitov <alexei.starovoitov@gmail.com> wrote:

> On Fri, Mar 25, 2022 at 7:43 AM Peter Zijlstra <peterz@infradead.org> wrote:
> >
> > On Fri, Mar 25, 2022 at 11:22:53PM +0900, Masami Hiramatsu wrote:
> >
> > > Masami Hiramatsu (3):
> > >       kprobes: Use rethook for kretprobe if possible
> > >       rethook: kprobes: x86: Replace kretprobe with rethook on x86
> > >       x86,kprobes: Fix optprobe trampoline to generate complete pt_regs
> > >
> > > Peter Zijlstra (1):
> > >       Subject: x86,rethook: Fix arch_rethook_trampoline() to generate a complete pt_regs
> >
> > You fat-fingered the subject there ^
> >
> > Other than that:
> >
> > Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
> >
> > Hopefully the ftrace return trampoline can also be switched over..
> 
> Thanks Peter. What's an ETA on landing endbr set?
> Did I miss a pull req?
> I see an odd error in linux-next with bpf selftests
> which may or may not be related. Planning to debug it
> when everything settles in Linus's tree.

That is what I pointed in cover mail.

> BTW, this patch can be applied to next-20220324, not the bpf-next tree
> directly, because this depends on ANNOTATE_NOENDBR macro. However, since
> the fprobe is merged in the bpf-next, I marked this for bpf-next.
> So until merging the both of fprobes and ENDBR series, to compile this
> you need below 2 lines in arch/x86/kernel/rethook.c.
> 
> #ifndef ANNOTATE_NOENDBR
> #define ANNOTATE_NOENDBR

> 
> Masami, could you do another respin?

OK, I will add above temporary mitigation.

> 
> Also do you mind squashing patches 2,3,4 ?
> It's odd to have the same lines of code patched up 3 times.
> Just do it right once.

Hmm, I think those are different commit for different features.
I would like to keep those 3 patches separated (for the case if
we find any issue to introduce regs->ss later)

Thank you,

-- 
Masami Hiramatsu <mhiramat@kernel.org>