linux-kernel - Re: [PATCH v2] of: WARN on deprecated #address-cells/#size-cells handling

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <874j4ava8a.fsf@mpe.ellerman.id.au>
Date: Thu, 14 Nov 2024 13:07:49 +1100
From: Michael Ellerman <mpe@...erman.id.au>
To: Geert Uytterhoeven <geert@...ux-m68k.org>
Cc: "Rob Herring (Arm)" <robh@...nel.org>, Saravana Kannan
 <saravanak@...gle.com>, linuxppc-dev@...ts.ozlabs.org, Conor Dooley
 <conor@...nel.org>, devicetree@...r.kernel.org,
 linux-kernel@...r.kernel.org
Subject: Re: [PATCH v2] of: WARN on deprecated #address-cells/#size-cells
 handling

Geert Uytterhoeven <geert@...ux-m68k.org> writes:
> On Thu, Nov 7, 2024 at 12:37 PM Michael Ellerman <mpe@...erman.id.au> wrote:
>> "Rob Herring (Arm)" <robh@...nel.org> writes:
>> > While OpenFirmware originally allowed walking parent nodes and default
>> > root values for #address-cells and #size-cells, FDT has long required
>> > explicit values. It's been a warning in dtc for the root node since the
>> > beginning (2005) and for any parent node since 2007. Of course, not all
>> > FDT uses dtc, but that should be the majority by far. The various
>> > extracted OF devicetrees I have dating back to the 1990s (various
>> > PowerMac, OLPC, PASemi Nemo) all have explicit root node properties.
>>
>> I have various old device trees that have been given to me over the
>> years, and as far as I can tell they all have these properties (some of
>> them are partial trees so it's hard to be 100% sure).
>
> Apparently CHRP LongTrail only had #address-cells in the root node.
> Interestingly, /cpus does have a (zero) @size-cells property.
> http://g33rt.be/migrated/Linux/PPC/root.html
> http://g33rt.be/migrated/Linux/PPC/DeviceTree.html
>
> No idea if any of them are still alive.

OK. We could fix that up in prom_init() if necessary - there's already a
bunch of workarounds in there for longtrail.

cheers