[systemd-devel] logind: multiseat without framebuffer graphic cards

[Oleg Samarin]

В Вс., 25/11/2012 в 02:21 +0100, Kay Sievers пишет:
> On Sat, Nov 24, 2012 at 10:46 PM, Lennart Poettering
> <lennart at poettering.net> wrote:
> 
> > This sounds as if it should be tagged with uaccess, so that it is
> > managed by dynamic ACLs as sessoins become active and inactive.
> >
> > Kay, what's the story behind /dev/snd/seq and ACLs?
> 
> Should work fine when the driver is loaded. The module is usually not
> loaded though.

If snd_seq is not loaded, then /dev/snd/seq has no ACL at all.

After loading snd_seq /dev/snd/seq becomes accessible in a single seat
enviroment. But after configuring seat1 it stops working on both seat0
and seat1.

> The auto-loading on user access by the kernel does not trigger,
> because the ACL only gets applied to a real device, not a "dead"
> device node.
> 
> So, either the primary permissions of the node need to be relaxed, the
> module needs to be always force-loaded, or the ACL setting logic would
> need to be changed to include "dead" nodes without a device.

F17 has a bug causes snd_seq is not loaded on boot. But after I used a
workaround (placing 'install snd-pcm /usr/sbin/modprobe --ignore-install
snd-pcm && /usr/sbin/modprobe snd-seq'
to /etc/modprobe.d/dist-alsa.conf), /dev/snd/seq started working, but
only in single-seat environment.