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Date: Mon, 2 Dec 2019 10:47:59 +0000
From: Mark Rutland <mark.rutland@arm.com>
To: Kees Cook <keescook@chromium.org>
Cc: Kassad <aashad940@gmail.com>, kernel-hardening@lists.openwall.com
Subject: Re: Contributing to KSPP newbie
Message-ID: <20191202104759.GB24608@lakrids.cambridge.arm.com>
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User-Agent: Mutt/1.11.1+11 (2f07cb52) (2018-12-01)

On Sat, Nov 30, 2019 at 08:48:23AM -0800, Kees Cook wrote:
> On Fri, Nov 29, 2019 at 11:29:13AM +0000, Mark Rutland wrote:
> > On Thu, Nov 28, 2019 at 11:39:11PM -0500, Kassad wrote:
> > > Hey Kees,
> > > 
> > > I'm 3rd university student interested in learning more about the linux kernel.
> > > I'm came across this subsystem, since it aligns with my interest in security.
> > > Do you think as a newbie this task https://github.com/KSPP/linux/issues/11 will
> > > be a good starting point?
> > 
> > I think this specific task (Disable arm32 kuser helpers) has already
> > been done, and the ticket is stale.
> 
> Oh, thank you! I entirely missed both of these commits. I've added
> notes to the bug and closed it.

Great!

> > On arm CONFIG_KUSER_HELPERS can be disabled on kernels that don't need
> > to run on HW prior to ARMv6. See commit:
> > 
> >   f6f91b0d9fd971c6 ("ARM: allow kuser helpers to be removed from the vector page")
> > 
> > On arm64, CONFIG_KUSER_HELPERS can be disabled on any kernel. See
> > commit:
> > 
> >   1b3cf2c2a3f42b ("arm64: compat: Add KUSER_HELPERS config option")
> 
> (Typo: a1b3cf2c2a3f42b)

I see you use vim. ;)

Mark.