I think that's the real meat of the kernel developer decision to keep Nvidia away from DMA-BUF. Why hand them something else that will be useful for them to harm people with (with their blob being proprietary and hazardous to system integrity)? Why give them more incentive to continue being parasites that never work upstream and just ship a blob of crap with a kernel glue layer later on?
Originally Posted by asdx
It's not just about Free Software, either. Nvidia already exposes their users to many security problems, such as that example back in August. The TL;DR of that is (1) Nvidia knew about the problem for over a year because it had been privately reported, (2) The problem was a local root exploit that their blob facilitated due to unsafe use of /dev/shmem, and (3) they fixed it in a matter of days *after* one of the kernel developers released a proof of concept and embarassed them on Slashdot.
I have to assume that handing Nvidia another kernel interface to abuse will just lead to more bugs that expose many more nasty security problems when you use their blob driver on Linux.
As much as the kernel developers want to wash their hands of Nvidia and AMD's blobs that cause all sorts of weird errors (warnings, oopses, and panics), they still end up getting users that try to submit bug reports to upstream (or to their distribution) that were caused by having nvidia or catalyst loaded. Sifting through bug reports to decide that there's nothing you can do about it because it's not your bug and the proprietary software company that made the driver may or may not ever get around to fixing it is not "free", it wastes the time of people who have to triage bug reports. They will spend at least a minute or two just looking at the bug report, seeing that the user has Nvidia or Catalyst loaded, and deciding to render it INVALID.
They should make life as difficult as possible for Nvidia as long as Nvidia insists on being uncooperative. If the feature is something Nvidia really wants, then maybe they will open some of THEIR code to gain access to the kernel interface.
In the mean time, it's nice (in a spiteful sort of way) to do to Nvidia exactly what they've done to Nouveau for a change. "Nyah! Nyah! We do something cool and we're not going to let you use it!".
Last edited by DaemonFC; 10-14-2012 at 12:25 AM.