[PATCH 01/13] drm/amdgpu: introduce and honour DRM_FORCE_AUTH workaround

Michel Dänzer michel at daenzer.net
Fri Jun 21 07:41:20 UTC 2019

On 2019-06-21 9:12 a.m., Koenig, Christian wrote:
> First of all I tried to disable DRM authentication completely with a 
> kernel config option. Surprisingly that actually works out of the box at 
> least on the AMDGPU stack.
> This effectively allows us to get rid of DRI2 and the related security 
> problems. Only thing left for that is that I'm just not sure how to 
> signal this to userspace so that the DDX wouldn't advertise DRI2 at all 
> any more.

FWIW, getting rid of DRI2 also needs to be discussed with amdgpu-pro
OpenGL driver folks.

> As a next step I looked into if we can disable the command submission 
> for DRM master. Turned out that this is relatively easy as well.
> All we have to do is to fix the bug Michel pointed out about KMS handles 
> for display

I'm working on that, consider it fixed.

> and let the DDX use a render node instead of the DRM master for Glamor.
> Still need to sync up with Michel and/or Marek whats the best way of
> doing this.

My suggestion was to add a new variant of amdgpu_device_initialize. When
the new variant is called, libdrm_amdgpu internally uses a render node
for command submission etc. whenever possible.

Earthling Michel Dänzer               |              https://www.amd.com
Libre software enthusiast             |             Mesa and X developer

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