linux-kernel - Re: [PATCH v1] partitions/efi: Add 'gpt

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:   Wed, 19 Feb 2020 08:27:38 -0800
From:   Christoph Hellwig <hch@...radead.org>
To:     Dmitry Osipenko <digetx@...il.com>
Cc:     Jens Axboe <axboe@...nel.dk>, Davidlohr Bueso <dave@...olabs.net>,
        Colin Cross <ccross@...roid.com>,
        Thierry Reding <thierry.reding@...il.com>,
        Jonathan Hunter <jonathanh@...dia.com>,
        Michał Mirosław <mirq-linux@...e.qmqm.pl>,
        David Heidelberg <david@...t.cz>,
        Peter Geis <pgwipeout@...il.com>, linux-efi@...r.kernel.org,
        linux-tegra@...r.kernel.org, linux-block@...r.kernel.org,
        linux-doc@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH v1] partitions/efi: Add 'gpt_sector' kernel cmdline
 parameter

On Wed, Feb 19, 2020 at 07:23:39PM +0300, Dmitry Osipenko wrote:
> The gpt_sector=<sector> causes the GPT partition search to look at the
> specified sector for a valid GPT header if the GPT is not found at the
> beginning or the end of block device.
> 
> In particular this is needed for NVIDIA Tegra consumer-grade Android
> devices in order to make them usable with the upstream kernel because
> these devices use a proprietary / closed-source partition table format
> for the EMMC and it's impossible to change the partition's format. Luckily
> there is a GPT table in addition to the proprietary table, which is placed
> in uncommon location of the EMMC storage and bootloader passes the
> location to kernel using "gpt gpt_sector=<sector>" cmdline parameters.
> 
> This patch is based on the original work done by Colin Cross for the
> downstream Android kernel.

I don't think a magic command line is the way to go.  The best would be
to reverse-engineer the proprietary partition table format.  If that is
too hard we can at least key off the odd GPT location based of it's
magic number.