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In-Reply-To: <4302f36bd615c179c92f2007a0f3a1215ba96c55.1531439662.git.christophe.leroy@c-s.fr>
To: Christophe Leroy <christophe.leroy@c-s.fr>,
 Benjamin Herrenschmidt <benh@kernel.crashing.org>,
 Paul Mackerras <paulus@samba.org>
From: Michael Ellerman <patch-notifications@ellerman.id.au>
Cc: linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org
Subject: Re: powerpc/8xx: fix handling of early NULL pointer dereference
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Date: Tue, 24 Jul 2018 01:11:17 +1000 (AEST)
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On Fri, 2018-07-13 at 13:10:47 UTC, Christophe Leroy wrote:
> NULL pointers are pointers to user memory space. So user pagetable
> has to be set in order to avoid random behaviour in case of NULL
> pointer dereference, otherwise we may encounter random memory
> access hence Machine Check Exception from TLB Miss handlers.
> 
> Set user pagetable as early as possible in order to properly
> catch early kernel NULL pointer dereference.
> 
> Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>

Applied to powerpc next, thanks.

https://git.kernel.org/powerpc/c/8c8c10b90d88bfaad41ea34df17bf6

cheers