Bug#799948: Permission issue with GDM and NVidia

[Luca Boccassi]

On Sep 29, 2015 09:09, "Aigars Mahinovs" <aigarius at gmail.com> wrote:
>
> Looks possible - I also had the glx-diversions updated from 0.5.1 to
0.6.0 at the same time.
>
> On Tue, Sep 29, 2015 at 8:21 AM Diederik de Haas <didi.debian at cknow.org>
wrote:
>>
>> On Monday 28 September 2015 23:19:30 Aigars Mahinovs wrote:
>> > I can confirm that the issue rescribed in bug #800327 is real and the
>> > workaround of adding Debian-gdm user to the video group works.
>>
>> That workaround was also posted on
http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=799948 and the cause seems
to be the upgrade of glx-
>> diversions to version 0.6.0.
>> I wouldn't be surprised if that is the case with you too.

I believe it's a side effect of a new feature introduced by nvidia-driver
340.93-2 and glx-alternatives 0.6 combined, namely the auto-generation of
the xorg.conf and the auto-loading of the necessary kernel modules.

IMHO this is a great feature to have and it makes the life of the users
much simpler. So the question is how to deal with the permission problem.

Adding the DM users to the video group in the driver postinst seems the
basic solution, but it's not enough as a chicken-and-egg situation could
happen (eg: a GDM-Nvidia user installs sddm later). So the only way to be
sure would be to also create the DM users if not present at the driver
install time. But how will the various DM packages deal with the fact that
the user already exists at install time? Will it cause problems?

Another solution would be having the DM packages themselves add their users
to the video group on install as well, but I'd be wary of adding
workarounds in other packages, especially when it involves extending
privileges, and I suspect the respective mainteiners feel the same way.

Andreas, Vincent, what are your thoughts on this?

I'll try and have a play and investigate in the following days.

Kind regards,
Luca Boccassi
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.alioth.debian.org/pipermail/pkg-nvidia-devel/attachments/20150929/cc564f86/attachment-0003.html>