Re: Unsupported CONFIG_FPROBE and CONFIG_RETHOOK on ARM64

[Masami Hiramatsu (Google) <mhiramat@kernel.org>]

On Wed, 11 Sep 2024 13:18:12 -0700
Andrii Nakryiko <andrii.nakryiko@gmail.com> wrote:

> > > So while I get the desire to have a clean and nice
> > > end goal, and that it might take a bit longer to get everything right.
> > > But, maybe, landing a stop-gap solution meanwhile (especially as
> > > isolated and thus easily backportable as the patch [0] you referenced)
> > > is an OK path forward?
> >
> > I had not realized that the PSTATE register was not saved correctly
> > at that point. This is one reason why I decided to move in the
> > current fprobe-on-fgraph direction.
> 
> Sure, but you said yourself, the same problem exists with current
> kretprobe implementation, so this won't regress anything. And yes,
> your fprobe-on-fgraph series is supposed to fix this for good, which
> is great, but that's a separate topic.

It does not regress kretprobe, but introduces the same problem to
fprobe. And since fprobe-on-fgraph was boosted by this problem,
I think that is not a separate topic.

Thank you,

-- 
Masami Hiramatsu (Google) <mhiramat@kernel.org>