Am 27.05.19 um 17:26 schrieb Daniel Vetter: > On Mon, May 27, 2019 at 3:42 PM Koenig, Christian > <Christian.Koenig@xxxxxxx> wrote: >> Am 27.05.19 um 15:26 schrieb Emil Velikov: >>> On 2019/05/27, Daniel Vetter wrote: >>>> On Mon, May 27, 2019 at 10:47:39AM +0000, Koenig, Christian wrote: >>>>> Am 27.05.19 um 10:17 schrieb Emil Velikov: >>>>>> From: Emil Velikov <emil.velikov@xxxxxxxxxxxxx> >>>>>> >>>>>> Currently one can circumvent DRM_AUTH, when the ioctl is exposed via the >>>>>> render node. A seemingly deliberate design decision. >>>>>> >>>>>> Hence we can drop the DRM_AUTH all together (details in follow-up patch) >>>>>> yet not all userspace checks if it's authenticated, but instead uses >>>>>> uncommon assumptions. >>>>>> >>>>>> After days of digging through git log and testing, only a single (ab)use >>>>>> was spotted - the Mesa RADV driver, using the AMDGPU_INFO ioctl and >>>>>> assuming that failure implies lack of authentication. >>>>>> >>>>>> Affected versions are: >>>>>> - the whole 18.2.x series, which is EOL >>>>>> - the whole 18.3.x series, which is EOL >>>>>> - the 19.0.x series, prior to 19.0.4 >>>>> Well you could have saved your time, cause this is still a NAK. >>>>> >>>>> For the record: I strongly think that we don't want to expose any render >>>>> functionality on the primary node. >>>>> >>>>> To even go a step further I would say that at least on AMD hardware we >>>>> should completely disable DRI2 for one of the next generations. >>>>> >>>>> As a follow up I would then completely disallow the DRM authentication >>>>> for amdgpu, so that the command submission interface on the primary node >>>>> can only be used by the display server. >>>> So amdgpu is running in one direction, while everyone else is running in >>>> the other direction? Please note that your patch to change i915 landed >>>> already, so that ship is sailing (but we could ofc revert that back >>>> again). >>>> >>>> Imo really not a great idea if we do a amdgpu vs. everyone else split >>>> here. If we want to deprecate dri2/flink/rendering on primary nodes across >>>> the stack, then that should be a stack wide decision, not an amdgpu one. >>>> >>> Cannot agree more - I would love to see drivers stay consistent. >> Yeah, completely agree to that. That's why I think we should not do this >> at all and just let Intel fix it's userspace bugs :P > So you're planning to submit that revert? You did jump the gun with > sending out that patch after all too ... (aside from it got merged > because of some other mixup with r-b tags and what not). Well already regretting submitting that. On the other hand what is the minimum IOCTLs we need to get working to fix the vainfo issue? Might be a good idea looking into reverting it partially, so that at least command submission and buffer allocation is still blocked. Christian. > -Daniel > >> Anyway my concern is really that we should stop extending functionality >> on the primary node. >> >> E.g. the render node is for use by the clients and the primary node for >> mode setting and use by the display server only. >> >> Regards, >> Christian. >> >>> Fwiw, this series consistently paves the way toward nuking DRM_AUTH ;-) >>> >>> Thanks >>> Emil > _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel
