From: Chris Wilson chris@chris-wilson.co.uk Subject: Re: [proof-of-concept/rfc] per object file mmaps To: Dave Airlie airlied@gmail.com, dri-devel@lists.freedesktop.org In-Reply-To: 1355892119-13926-1-git-send-email-airlied@gmail.com References: 1355892119-13926-1-git-send-email-airlied@gmail.com
On Wed, 19 Dec 2012 14:41:56 +1000, Dave Airlie airlied@gmail.com wrote:
The 2+3 patches are actually the code, the first was just a cleanup.
Anyways the second patch describes it best, but I've taken the approach that we just need to keep track of what filp this object has had a handle created on, and block mmaps on it. We could also probably block a bit more explicitly in the driver respective mmap offset retrieval ioctls, however we need to block in mmap itself to stop people just picking misc address and trying them.
It doesn't really add much now, but with render nodes where we have flink_to or fd passing it would be more useful.
I've no idea if I'll get to do much more with this, so consider it an indication of how I'd like it done for someone else to run with :-)
Locking looks entirely non-existent for per-file mmap add/remove in the generic gem code. Also we have a pair of hooks there that look like they would be a convenient point to place that code. -Chris