Re: [PATCH 2/4] kfence: add function to mask address bits

From: Marco Elver <elver@google.com>
To: Heiko Carstens <hca@linux.ibm.com>
Cc: Alexander Potapenko <glider@google.com>,
	Sven Schnelle <svens@linux.ibm.com>,
	Vasily Gorbik <gor@linux.ibm.com>,
	Christian Borntraeger <borntraeger@de.ibm.com>,
	kasan-dev@googlegroups.com, linux-mm@kvack.org,
	linux-kernel@vger.kernel.org, linux-s390@vger.kernel.org
Subject: Re: [PATCH 2/4] kfence: add function to mask address bits
Date: Thu, 29 Jul 2021 14:27:30 +0200	[thread overview]
Message-ID: <CANpmjNPWj2vjNd2V-Wqgh1+AvmKQEbg=Qh43DQ_5P2vNv7+JDw@mail.gmail.com> (raw)
In-Reply-To: <YQKeNbU4HJhFP8kn@osiris>

On Thu, 29 Jul 2021 at 14:25, Heiko Carstens <hca@linux.ibm.com> wrote:
> On Thu, Jul 29, 2021 at 09:48:58AM +0200, Marco Elver wrote:
> > On Wed, Jul 28, 2021 at 09:02PM +0200, Heiko Carstens wrote:
> > > From: Sven Schnelle <svens@linux.ibm.com>
> > >
> > > s390 only reports the page address during a translation fault.
> > > To make the kfence unit tests pass, add a function that might
> > > be implemented by architectures to mask out address bits.
> > >
> > > Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
> > > Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
> >
> > I noticed this breaks on x86 if CONFIG_KFENCE_KUNIT_TEST=m, because x86
> > conditionally declares some asm functions if !MODULE.
> >
> > I think the below is the simplest to fix, and if you agree, please carry
> > it as a patch in this series before this patch.
>
> Will do.
>
> > With the below, you can add to this patch:
> >
> >       Reviewed-by: Marco Elver <elver@google.com>
>
> Done - Thank you! I silently assume this means also you have no
> objections if we carry this via the s390 tree for upstreaming.

I think that's reasonable. I'm not aware of any conflicts, nor am I
expecting any for the upcoming cycle.

Thanks,
-- Marco