[PATCH] drm/gem: Add new flink_to ioctl

[Kristian Høgsberg]

On Thu, Jul 8, 2010 at 11:59 AM, Keith Packard <keithp at keithp.com> wrote:
> On Thu,  8 Jul 2010 11:23:25 -0400, Kristian Høgsberg <krh at bitplanet.net> wrote:
>
>>  - a mechanism to attach a binary blob to an flink_to buffer name.
>>    open_with_data returns the data.  Userspace (typically libdrm)
>>    decides the layout and versioning of the blob and the contents
>>    will be chipset specific.  it's an opaque blob to the kernel,
>>    which doesn't need to know about stride and formats etc.
>
> Arbitrary binary blobs considered harmful? Even if the kernel doesn't
> need to know all of this data, having it in an explicit (versioned)
> format will protect applications from randomly mis-interpreting the data.

I talked with ickle about that and whether or not to include a
version+format u32 for the data in the ioctl args.  He convinced me
that the kernel didn't need to know about the layout of the blob and
that requiring by convention that the first u32 of the blob is the
version+format u32 would suffice.  I can go either way on this, but I
guess I have a small preference for making it part of the ioctl args
as you suggest.

Kristian