Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
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
Message-Id: <41Z4h573nxz9s7c@ozlabs.org>
Date:   Tue, 24 Jul 2018 01:11:17 +1000 (AEST)
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

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