Hi On Wed, Sep 9, 2015 at 3:03 PM, Daniel Vetter <daniel@xxxxxxxx> wrote: > On Wed, Sep 09, 2015 at 02:21:33PM +0200, David Herrmann wrote: >> Now that we support connector hotplugging, user-space might see >> mode-object IDs coming and going asynchronously. Therefore, we must make >> sure to not re-use object IDs, so to not confuse user-space and introduce >> races. Therefore, all kernel-allocated objects will no longer recycle >> IDs. Instead, we use the cyclic idr allocator (which performs still fine >> for reasonable allocation schemes). >> >> However, for user-space allocated objects like framebuffers, we don't >> want to risk allowing malicious users to screw with the ID space. >> Furthermore, those objects happen to not be subject to ID hotplug races, >> as they're allocated and freed explicitly. Hence, we still recycle IDs >> for these objects (which are just framebuffers so far). > > Since atomic also blob properties can be created by userspace. And there > has actually been trouble once with some attempt in SNA to cache the edid > blob without realizing that they get reused. So working userspace _always_ > has to re-read the blob prop to make sure it has the current one anyway. I see. So lets include the blobs in recycle, too? This makes the patch a bit more clunky as we need to distinguish kernel-generated blobs and user-space generated blobs. I'll see how that works out. Thanks David _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/dri-devel
