* The controlD device
@ 2011-10-21 14:06 Thomas Hellstrom
2011-10-21 14:18 ` Dave Airlie
0 siblings, 1 reply; 6+ messages in thread
From: Thomas Hellstrom @ 2011-10-21 14:06 UTC (permalink / raw)
To: Dave Airlie; +Cc: dri-devel@lists.freedesktop.org
Dave,
What is the drm control device nodes really used for?
On my fc14 system it seems like it has world rw privileges, and full
access to all modesetting ioctls.
Is that the intention?
/Thomas
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: The controlD device
2011-10-21 14:06 The controlD device Thomas Hellstrom
@ 2011-10-21 14:18 ` Dave Airlie
2011-10-21 14:36 ` Dave Airlie
0 siblings, 1 reply; 6+ messages in thread
From: Dave Airlie @ 2011-10-21 14:18 UTC (permalink / raw)
To: Thomas Hellstrom; +Cc: Dave Airlie, dri-devel@lists.freedesktop.org
On Fri, Oct 21, 2011 at 3:06 PM, Thomas Hellstrom <thellstrom@vmware.com> wrote:
> Dave,
>
> What is the drm control device nodes really used for?
>
> On my fc14 system it seems like it has world rw privileges, and full access
> to all modesetting ioctls.
> Is that the intention?
No, and I just realised we packaged a broken udev rule.
It should be root only, oops.
Its intention is for setting up multi-seat and gpgpu access to the drm.
change /etc/udev/rules.d/91-modeset.rules to be 0600.
Dave.
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: The controlD device
2011-10-21 14:18 ` Dave Airlie
@ 2011-10-21 14:36 ` Dave Airlie
2011-10-21 16:03 ` Thomas Hellstrom
0 siblings, 1 reply; 6+ messages in thread
From: Dave Airlie @ 2011-10-21 14:36 UTC (permalink / raw)
To: Thomas Hellstrom; +Cc: Dave Airlie, dri-devel@lists.freedesktop.org
On Fri, Oct 21, 2011 at 3:18 PM, Dave Airlie <airlied@gmail.com> wrote:
> On Fri, Oct 21, 2011 at 3:06 PM, Thomas Hellstrom <thellstrom@vmware.com> wrote:
>> Dave,
>>
>> What is the drm control device nodes really used for?
>>
>> On my fc14 system it seems like it has world rw privileges, and full access
>> to all modesetting ioctls.
>> Is that the intention?
>
> No, and I just realised we packaged a broken udev rule.
>
> It should be root only, oops.
>
> Its intention is for setting up multi-seat and gpgpu access to the drm.
>
> change /etc/udev/rules.d/91-modeset.rules to be 0600.
I've filed updates to Fedora to fix this, no other distro should be
using or caring about these device nodes yet, since we never really
got GPGPU going yet.
Dave.
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: The controlD device
2011-10-21 14:36 ` Dave Airlie
@ 2011-10-21 16:03 ` Thomas Hellstrom
2011-10-21 16:48 ` Dave Airlie
0 siblings, 1 reply; 6+ messages in thread
From: Thomas Hellstrom @ 2011-10-21 16:03 UTC (permalink / raw)
To: Dave Airlie; +Cc: Dave Airlie, dri-devel@lists.freedesktop.org
On 10/21/2011 04:36 PM, Dave Airlie wrote:
> On Fri, Oct 21, 2011 at 3:18 PM, Dave Airlie<airlied@gmail.com> wrote:
>
>> On Fri, Oct 21, 2011 at 3:06 PM, Thomas Hellstrom<thellstrom@vmware.com> wrote:
>>
>>> Dave,
>>>
>>> What is the drm control device nodes really used for?
>>>
>>> On my fc14 system it seems like it has world rw privileges, and full access
>>> to all modesetting ioctls.
>>> Is that the intention?
>>>
>> No, and I just realised we packaged a broken udev rule.
>>
>> It should be root only, oops.
>>
>> Its intention is for setting up multi-seat and gpgpu access to the drm.
>>
>> change /etc/udev/rules.d/91-modeset.rules to be 0600.
>>
> I've filed updates to Fedora to fix this, no other distro should be
> using or caring about these device nodes yet, since we never really
> got GPGPU going yet.
>
> Dave.
>
Sounds good. I was actually mostly curios on the intended usage pattern
of the control node.
I found some things on the DRM wikis, but it doesn't at all seem
consistent with what's in DRM.
Why do we have CONTROL_ALLOW on all modesetting ioctls?, also this code
in drm_crtc.c seems odd:
if (file_priv->master->minor->type == DRM_MINOR_CONTROL) {
...
Isn't that equivalent to
if (file_priv->minor->type == DRM_MINOR_CONTROL) { ?
Any enlightenment would be appreciated.
Thanks,
/Thomas
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: The controlD device
2011-10-21 16:03 ` Thomas Hellstrom
@ 2011-10-21 16:48 ` Dave Airlie
2011-10-21 19:16 ` Thomas Hellstrom
0 siblings, 1 reply; 6+ messages in thread
From: Dave Airlie @ 2011-10-21 16:48 UTC (permalink / raw)
To: Thomas Hellstrom; +Cc: Dave Airlie, dri-devel@lists.freedesktop.org
>
> Why do we have CONTROL_ALLOW on all modesetting ioctls?, also this code in
> drm_crtc.c seems odd:
The plan was to allow a master daemon to create seats and compute
nodes, on reflection it probably didn't need *all* the modesetting
ioctls,
just the GetResources one.
So gdm or some equivalent would keep control over the control node,
and could be used to establish seats via render nodes.
Render nodes could have various crtc/outputs assigned to them.
A GPGPU render node would have 0 output pieces attached.
> if (file_priv->master->minor->type == DRM_MINOR_CONTROL) {
> ...
>
> Isn't that equivalent to
>
> if (file_priv->minor->type == DRM_MINOR_CONTROL) { ?
Yeah most likely just over thinking something. should be the same.
I had a tree on k.org with this stuff more fleshed out,
I've just pushed it out here:
http://cgit.freedesktop.org/~airlied/linux/log/?h=drm-render-nodes
Dave.
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: The controlD device
2011-10-21 16:48 ` Dave Airlie
@ 2011-10-21 19:16 ` Thomas Hellstrom
0 siblings, 0 replies; 6+ messages in thread
From: Thomas Hellstrom @ 2011-10-21 19:16 UTC (permalink / raw)
To: Dave Airlie; +Cc: Dave Airlie, dri-devel@lists.freedesktop.org
On 10/21/2011 06:48 PM, Dave Airlie wrote:
>> Why do we have CONTROL_ALLOW on all modesetting ioctls?, also this code in
>> drm_crtc.c seems odd:
>>
> The plan was to allow a master daemon to create seats and compute
> nodes, on reflection it probably didn't need *all* the modesetting
> ioctls,
> just the GetResources one.
>
> So gdm or some equivalent would keep control over the control node,
> and could be used to establish seats via render nodes.
> Render nodes could have various crtc/outputs assigned to them.
> A GPGPU render node would have 0 output pieces attached.
>
>
>> if (file_priv->master->minor->type == DRM_MINOR_CONTROL) {
>> ...
>>
>> Isn't that equivalent to
>>
>> if (file_priv->minor->type == DRM_MINOR_CONTROL) { ?
>>
> Yeah most likely just over thinking something. should be the same.
>
> I had a tree on k.org with this stuff more fleshed out,
> I've just pushed it out here:
> http://cgit.freedesktop.org/~airlied/linux/log/?h=drm-render-nodes
>
>
OK. Thanks. Got a better understanding what it's all about now.
/Thomas
> Dave.
>
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2011-10-21 19:18 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2011-10-21 14:06 The controlD device Thomas Hellstrom
2011-10-21 14:18 ` Dave Airlie
2011-10-21 14:36 ` Dave Airlie
2011-10-21 16:03 ` Thomas Hellstrom
2011-10-21 16:48 ` Dave Airlie
2011-10-21 19:16 ` Thomas Hellstrom
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