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Subject: Re: [PATCH v5 0/4] KASAN for powerpc64 radix
To:     Daniel Axtens <dja@axtens.net>, linux-kernel@vger.kernel.org,
        linux-mm@kvack.org, linuxppc-dev@lists.ozlabs.org,
        kasan-dev@googlegroups.com, aneesh.kumar@linux.ibm.com,
        bsingharora@gmail.com
References: <20200109070811.31169-1-dja@axtens.net>
From:   Christophe Leroy <christophe.leroy@c-s.fr>
Message-ID: <8a1b7f4b-de14-90fe-2efa-789882d28702@c-s.fr>
Date:   Thu, 16 Jan 2020 10:34:05 +0100
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Le 09/01/2020 à 08:08, Daniel Axtens a écrit :
> Building on the work of Christophe, Aneesh and Balbir, I've ported
> KASAN to 64-bit Book3S kernels running on the Radix MMU.
> 
> This provides full inline instrumentation on radix, but does require
> that you be able to specify the amount of physically contiguous memory
> on the system at compile time. More details in patch 4.

This might be a stupid idea as I don't know ppc64 much. IIUC, PPC64 
kernel can be relocated, there is no requirement to have it at address 
0. Therefore, would it be possible to put the KASAN shadow mem at the 
begining of the physical memory, instead of putting it at the end ?
That way, you wouldn't need to know the amount of memory at compile time 
because KASAN shadow mem would always be at address 0.

Christophe