linux-kernel - Re: [PATCH] powerpc/603: Clear C bit when PTE is read only

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Date:   Tue, 15 Feb 2022 16:26:44 +1100
From:   Michael Ellerman <patch-notifications@...erman.id.au>
To:     Benjamin Herrenschmidt <benh@...nel.crashing.org>,
        Paul Mackerras <paulus@...ba.org>,
        Christophe Leroy <christophe.leroy@...roup.eu>,
        Michael Ellerman <mpe@...erman.id.au>
Cc:     linux-kernel@...r.kernel.org, linuxppc-dev@...ts.ozlabs.org
Subject: Re: [PATCH] powerpc/603: Clear C bit when PTE is read only

On Mon, 31 Jan 2022 07:17:57 +0000, Christophe Leroy wrote:
> On book3s/32 MMU, PP bits don't offer kernel RO protection,
> kernel pages are always RW.
> 
> However, on the 603 a page fault is always generated when the
> C bit (change bit = dirty bit) is not set.
> 
> Enforce kernel RO protection by clearing C bit in TLB miss
> handler when the page doesn't have _PAGE_RW flag.
> 
> [...]

Applied to powerpc/next.

[1/1] powerpc/603: Clear C bit when PTE is read only
      https://git.kernel.org/powerpc/c/4634bf4455fe26f07dabf97c3585c9ccb86353c4

cheers