[PATCH 2/2 v3] drm/exynos: added userptr feature.

[KOSAKI Motohiro]

> My point is this ioctl will be restricted to one user (Xserver if i
> understand) and only this user, there is no fork in it so no need to
> worry about fork, just setting the vma as locked will be enough.
>
> But i don't want people reading this driver suddenly think that what
> it's doing is ok, it's not, it's hack and can never make to work
> properly on a general case, that's why it needs a big comment stating,
> stressing that. I just wanted to make sure Inki and Kyungmin
> understood that this kind of ioctl should be restricted to carefully
> selected user and that there is no way to make it general or reliable
> outside that.

first off, I'm not drm guy and then I don't intend to insist you. but if
application don't use fork, get_user_pages() has no downside. I guess we
don't need VM_LOCKED hack.

but again, up to drm folks.