[elrepo] Problem with CUDA since 331.67.elrepo

[Michael Lampe]

Phil Perry wrote:

>> 1) Packaging a piece of software also means to adapt it to how things
>> work
>> in a specific distribution. So one would expect that permissions for the
>> nvidia devices reproduce the logic of the distribution for dri devices.
>>   (Principle of least surprise.)
>>
>
> This FAQ (7.1):
>
> http://uk.download.nvidia.com/XFree86/Linux-x86/331.67/README/faq.html
>
> documents the default attributes nvidia-modprobe uses for creating
> device files and how to change those default values. Would you suggest
> changing these default values, and if so, to what?

No, I'm not refering to this. I'm refering to the way (video) device 
permissions are handled in EL5 and EL6, respectively.

EL5 creates them root:root 600 and then uses PAM to dynamically change 
this to <user>:root 600 for console logins and back after logout.

EL6 creates them root:video 660 and lets ConsoleKit add/remove an ACL 
for <user> on console login/logout.

(EL7 will do what EL6 does, but with systemd instead of ConsoleKit.)

I can offer the necessary patches for EL5 and EL6. (EL7 isn't released.)

If you don't like it that way, then you should at least go for a simple 
and honest solution: create all devices with a little script in 
/etc/init.d, set them up world writable once, and then simply stick to 
that.

Letting the kernel module tinker with device creation, allow it to 
change permissions so everybody just gets through, and then even add a 
suid root modprobe wrapper on top of that seems very much ill-minded, 
even if that is what Nvidia came up with.

-Michael