From:   Michael Ellerman <patch-notifications@ellerman.id.au>
To:     Benjamin Herrenschmidt <benh@kernel.crashing.org>,
        Paul Mackerras <paulus@samba.org>,
        Michael Ellerman <mpe@ellerman.id.au>,
        Christophe Leroy <christophe.leroy@csgroup.eu>
Cc:     linuxppc-dev@lists.ozlabs.org, stable@vger.kernel.org,
        linux-kernel@vger.kernel.org
In-Reply-To: <a21e9a057fe2d247a535aff0d157a54eefee017a.1636963688.git.christophe.leroy@csgroup.eu>
References: <a21e9a057fe2d247a535aff0d157a54eefee017a.1636963688.git.christophe.leroy@csgroup.eu>
Subject: Re: [PATCH] powerpc/8xx: Fix pinned TLBs with CONFIG_STRICT_KERNEL_RWX
Message-Id: <163714821663.1508509.919431268872483842.b4-ty@ellerman.id.au>
Date:   Wed, 17 Nov 2021 22:23:36 +1100
MIME-Version: 1.0
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On Mon, 15 Nov 2021 09:08:36 +0100, Christophe Leroy wrote:
> As spotted and explained in commit c12ab8dbc492 ("powerpc/8xx: Fix
> Oops with STRICT_KERNEL_RWX without DEBUG_RODATA_TEST"), the selection
> of STRICT_KERNEL_RWX without selecting DEBUG_RODATA_TEST has spotted
> the lack of the DIRTY bit in the pinned kernel data TLBs.
> 
> This problem should have been detected a lot earlier if things had
> been working as expected. But due to an incredible level of chance or
> mishap, this went undetected because of a set of bugs: In fact the
> DTLBs were not pinned, because instead of setting the reserve bit
> in MD_CTR, it was set in MI_CTR that is the register for ITLBs.
> 
> [...]

Applied to powerpc/fixes.

[1/1] powerpc/8xx: Fix pinned TLBs with CONFIG_STRICT_KERNEL_RWX
      https://git.kernel.org/powerpc/c/1e35eba4055149c578baf0318d2f2f89ea3c44a0

cheers