linux-hardening - Re: [PATCH] drm/dp: Actually read Adjust Request Post Cursor2 register

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] [day] [month] [year] [list]

Message-ID: <87y24o7sry.fsf@intel.com>
Date:   Mon, 13 Dec 2021 11:34:09 +0200
From:   Jani Nikula <jani.nikula@...ux.intel.com>
To:     Kees Cook <keescook@...omium.org>
Cc:     Harry Wentland <harry.wentland@....com>,
        David Airlie <airlied@...ux.ie>, linux-kernel@...r.kernel.org,
        dri-devel@...ts.freedesktop.org, linux-hardening@...r.kernel.org,
        Thomas Zimmermann <tzimmermann@...e.de>,
        Thierry Reding <treding@...dia.com>
Subject: Re: [PATCH] drm/dp: Actually read Adjust Request Post Cursor2 register

On Fri, 10 Dec 2021, Kees Cook <keescook@...omium.org> wrote:
> On Fri, Dec 10, 2021 at 12:06:20PM +0200, Jani Nikula wrote:
>> Post Cursor2 was completely optional for the transmitter even before it
>> was deprecated.
>> 
>> And now we'd be adding 5 bytes extra to all link status reads. To fix
>> the only user of drm_dp_get_adjust_request_post_cursor() that apparently
>> has never worked as intended. I'm just not convinced.
>> 
>> I was trying to look through the implications of DP_LINK_STATUS_SIZE
>> increase, and at least drm_dp_dpcd_read_phy_link_status() comes across
>> as something probably needing attention.
>
> Okay, it sounds like you'd prefer the "make it tegra-specific" patch I
> proposed. I will work that up as a proper patch and send it.

Yes. Of course, I'd like to hear Thierry's view as well.

BR,
Jani.


-- 
Jani Nikula, Intel Open Source Graphics Center