linux-kernel - Re: [PATCH 3/3] drm/panfrost: Clamp lock region to Bifrost minimum

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]

Date:   Mon, 23 Aug 2021 17:13:45 -0400
From:   Alyssa Rosenzweig <alyssa@...labora.com>
To:     Steven Price <steven.price@....com>
Cc:     Alyssa Rosenzweig <alyssa.rosenzweig@...labora.com>,
        dri-devel@...ts.freedesktop.org, Rob Herring <robh@...nel.org>,
        Tomeu Vizoso <tomeu.vizoso@...labora.com>,
        David Airlie <airlied@...ux.ie>,
        Daniel Vetter <daniel@...ll.ch>, linux-kernel@...r.kernel.org,
        Chris Morgan <macromorgan@...mail.com>, stable@...r.kernel.org
Subject: Re: [PATCH 3/3] drm/panfrost: Clamp lock region to Bifrost minimum

> > When locking a region, we currently clamp to a PAGE_SIZE as the minimum
> > lock region. While this is valid for Midgard, it is invalid for Bifrost,
> 
> While the spec does seem to state it's invalid for Bifrost - kbase
> didn't bother with a lower clamp for a long time. I actually think this
> is in many ways more of a spec bug: i.e. implementation details of the
> round-up that the hardware does. But it's much safer following the spec
> ;) And it seems like kbase eventually caught up too.

Yeah, makes sense. Should I drop the Cc: stable in that case? If the
issue is purely theoretical.