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Date:   Tue, 20 Jun 2023 19:23:31 +0200
From:   Marco Elver <elver@google.com>
To:     Andrey Konovalov <andreyknvl@gmail.com>,
        Andrew Morton <akpm@linux-foundation.org>
Cc:     Alexander Potapenko <glider@google.com>,
        Dmitry Vyukov <dvyukov@google.com>,
        Taras Madan <tarasmadan@google.com>,
        Aleksandr Nogikh <nogikh@google.com>,
        Andrey Ryabinin <ryabinin.a.a@gmail.com>,
        Vincenzo Frascino <vincenzo.frascino@arm.com>,
        Jonathan Corbet <corbet@lwn.net>, kasan-dev@googlegroups.com,
        linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org,
        linux-mm@kvack.org, Catalin Marinas <catalin.marinas@arm.com>
Subject: Re: [PATCH] kasan: add support for kasan.fault=panic_on_write
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On Tue, Jun 20, 2023 at 06:27PM +0200, Andrey Konovalov wrote:
> On Tue, Jun 20, 2023 at 4:49 PM Marco Elver <elver@google.com> wrote:
> >
> > On Tue, Jun 20, 2023 at 03:56PM +0200, Andrey Konovalov wrote:
> > ...
> > > Could you move this to the section that describes the kasan.fault
> > > flag? This seems more consistent.
> >
> > Like this?
> >
> >
> > diff --git a/Documentation/dev-tools/kasan.rst b/Documentation/dev-tools/kasan.rst
> > index 7f37a46af574..f4acf9c2e90f 100644
> > --- a/Documentation/dev-tools/kasan.rst
> > +++ b/Documentation/dev-tools/kasan.rst
> > @@ -110,7 +110,9 @@ parameter can be used to control panic and reporting behaviour:
> >  - ``kasan.fault=report``, ``=panic``, or ``=panic_on_write`` controls whether
> >    to only print a KASAN report, panic the kernel, or panic the kernel on
> >    invalid writes only (default: ``report``). The panic happens even if
> > -  ``kasan_multi_shot`` is enabled.
> > +  ``kasan_multi_shot`` is enabled. Note that when using asynchronous mode of
> > +  Hardware Tag-Based KASAN, ``kasan.fault=panic_on_write`` always panics on
> > +  asynchronously checked accesses (including reads).
> >
> >  Software and Hardware Tag-Based KASAN modes (see the section about various
> >  modes below) support altering stack trace collection behavior:
> 
> Yes, this looks great! Thanks!

The patch here is already in mm-stable (which I recall doesn't do
rebases?), so I sent

 https://lkml.kernel.org/r/ZJHfL6vavKUZ3Yd8@elver.google.com

to be used as a fixup or just added to mm-stable by Andrew at one point
or another as well.

Thanks,
-- Marco