linux-kernel - Re: [PATCH V5 5/5] of: unittest: Statically apply overlays using fdtoverlay

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: <20210121233957.GA4400@yekko.fritz.box>
Date:   Fri, 22 Jan 2021 10:39:57 +1100
From:   David Gibson <david@...son.dropbear.id.au>
To:     Viresh Kumar <viresh.kumar@...aro.org>
Cc:     Frank Rowand <frowand.list@...il.com>,
        Rob Herring <robh+dt@...nel.org>,
        Pantelis Antoniou <pantelis.antoniou@...sulko.com>,
        Vincent Guittot <vincent.guittot@...aro.org>,
        Masahiro Yamada <masahiroy@...nel.org>,
        devicetree@...r.kernel.org, linux-kernel@...r.kernel.org,
        Bill Mills <bill.mills@...aro.org>, anmar.oueja@...aro.org
Subject: Re: [PATCH V5 5/5] of: unittest: Statically apply overlays using
 fdtoverlay

On Thu, Jan 21, 2021 at 12:27:28PM +0530, Viresh Kumar wrote:
> On 21-01-21, 17:34, David Gibson wrote:
> > No, this is the wrong way around.  The expected operation here is that
> > you apply overlay (1) to the base tree, giving you, say, output1.dtb.
> > output1.dtb is (effectively) a base tree itself, to which you can then
> > apply overlay-(2).
> 
> Thanks for the confirmation about this.
> 
> > Merging overlays is
> > something that could make sense, but fdtoverlay will not do it at
> > present.
> 
> FWIW, I think it works fine right now even if it not intentional.

No, it definitely will not work in general.  It might kinda work in a
few trivial cases, but it absolutely will not do the neccessary
handling in some cases.

> I
> did inspect the output dtb (made by merging two overlays) using
> fdtdump and it looked okay.

Ok.. but if you're using these bizarre messed up "dtbs" that this test
code seems to be, I don't really trust that tells you much.

> But yeah, I understand that we shouldn't
> do it.


-- 
David Gibson			| I'll have my music baroque, and my code
david AT gibson.dropbear.id.au	| minimalist, thank you.  NOT _the_ _other_
				| _way_ _around_!
http://www.ozlabs.org/~dgibson

Download attachment "signature.asc" of type "application/pgp-signature" (834 bytes)