Re: [RFC PATCH v2 00/13] mm/kwatch: dynamic hardware watchpoints for hunting memory corruption

On Tue, 21 Jul 2026 08:36:01 -0400
Jinchao Wang <[email protected]> wrote:

> On 7/20/2026 10:24 AM, Masami Hiramatsu (Google) wrote:
> > On Fri, 17 Jul 2026 11:10:04 -0700
> > Borislav Petkov <[email protected]> wrote:
> 
> >> Looks to me like folks need to sit down and agree on strategy first.
> > 
> > Yeah, I need to talk with Jinchao.
> > 
> > Like kprobe, wprobe itself integrates watchpoint functionality into
> > the tracing subsystem. Jinchao, I would like to ask you to redesign
> > the kwatch tool based on fprobe and wprobe events in user space?
> > I think that could reduce redundant efforts on the similar feature.
> > 
> > Using fprobe entry and exit event trigger, we can make a Function-
> > scoped watch window. Also, since fprobe and wprobe are having BTF
> > typecast support, you can access to the members of data structures
> > more naturally.
> > 
> > If you are interested, I would be open to having you handle the
> > development of the necessary features for wprobe.
> > 
> > Thank you,
> > 
> Thank you, Boris and Masami.
> 
> Boris is right that we should agree on the overall strategy before
> moving either series forward, especially since they share the low-level
> HWBP work. Masami is also right that fprobe and wprobe provide a more
> appropriate foundation than introducing KWatch as another standalone
> debugging tool.

Agreed. I just sent v10 because v9 lacked base-commit and Sashiko did
not reviewed. (so it just add a trigger-side BTF support which was
dropped in v9).
Think of v10 as the complete set of ideas we wanted to implement
with this wprobe.

> 
> After reconsidering the design, I will stop the standalone KWatch
> series. Instead, I would like to work with Masami on extending wprobe
> to support the function-scoped dynamic-watchpoint use cases that
> motivated KWatch.

Thanks Jinchao, I appreciate to work with you on this project.

> 
> Masami, thank you for being open to having me develop the necessary
> wprobe features. I am interested in taking that direction.

OK, please share your thoughts on watchpoint usage in the kernel.

Basically, I will fix the points raised in the review, but please
let me know if you have any other suggestions.

Thank you,

-- 
Masami Hiramatsu (Google) <[email protected]>