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Date: Wed, 2 May 2018 15:11:13 +0000
From: "Luis R. Rodriguez" <mcgrof@kernel.org>
To: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: "Luis R. Rodriguez" <mcgrof@kernel.org>,
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Subject: Re: [PATCH] mm: provide a fallback for PAGE_KERNEL_RO for
 architectures
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References: <20180428001526.22475-1-mcgrof@kernel.org>
 <CAMuHMdUpc6=j62E7Xrcid6tKU5FRUZsiSVK7J=KD09epQ=9xfA@mail.gmail.com>
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On Wed, May 02, 2018 at 12:08:57PM +0200, Geert Uytterhoeven wrote:
> Hi Luis,
> 
> On Sat, Apr 28, 2018 at 2:15 AM, Luis R. Rodriguez <mcgrof@kernel.org> wrote:
> > Some architectures do not define PAGE_KERNEL_RO, best we can do
> > for them is to provide a fallback onto PAGE_KERNEL. Remove the
> > hack from the firmware loader and move it onto the asm-generic
> > header, and document while at it the affected architectures
> > which do not have a PAGE_KERNEL_RO:
> >
> >   o alpha
> >   o ia64
> >   o m68k
> >   o mips
> >   o sparc64
> >   o sparc
> >
> > Blessed-by: 0-day
> > Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org>
> 
> I believe the "best we can do" is to add the missing definitions for the
> architectures where the hardware does support it?

True, but we cannot wait for every architecture to implement a feature to then
such generics upstream, specially when we have common places which use that.
Matthew did send a patch to add ia64 support for PAGE_KERNEL_RO, so I'll
respin the patch to add that and also move the other define he suggested.

At least we'd now have a list of documented archs which need further work too.

  Luis