Subject: Re: [PATCH v8 10/11] arm64/kasan: explicitly zero kasan shadow memory

From: Mark Rutland <[email-masked]>
Date: Fri, 15 Sep 2017 22:51:48 +0100

On Fri, Sep 15, 2017 at 05:20:59PM -0400, Pavel Tatashin wrote:
> Hi Mark,
> 
> I had this option  back upto version 3, where zero flag was passed into
> vmemmap_alloc_block(), but I was asked to remove it, because it required too
> many changes in other places.

Ok. Sorry for bringing back a point that had already been covered.

> So, the current approach is cleaner, but the idea is that kasan should use
> its own version of vmemmap_populate() for both x86 and ARM, but I think it is
> outside of the scope of this work.

I appreciate that this is unrelated to your ultimate goal, and that this is
somewhat frustrating given the KASAN code is arguably abusing the
vmemmap_populate() interface.

However, I do think we need to migrate the KASAN code to a proper interface
immediately, rather than making it worse in the interim.

> If you think I should add these function in this project, than sure I can
> send a new version with kasanmap_populate() functions.

I would very much appreciate if you could send a version with a
kasan_map_populate() interface. I'm more than happy to review/test that portion
of the series, or to help if there's some problem which makes that difficult.

Thanks,
Mark.