I have been looking through Egbert Eich's patch to add 32-bit compatibility code for the DRM ioctls on 64-bit platforms.
First off, has anyone updated the patch lately? The patch adds an extra field to the drm_map_t to handle the problem of the `handle' field being basically a kernel virtual address which gets exposed to userland. His patch seems to go to considerable lengths to translate between 32-bit handles and 64-bit handles, and the extra field in the drm_map_t basically means a change to the ABI, which I'd rather avoid if possible. There is also the `offset' field, which seems to have a similar function in terms of distinguishing between different regions of the address space. The `handle', though, seems to be always a vmalloc'd or ioremap'd address. How does userspace use the handle? Does userspace treat it as a purely opaque value? Could we perhaps synthesize a 32-bit handle cheaply by combining the offset and type fields? (or even just use offset >> 12 perhaps?) Paul. ------------------------------------------------------- SF email is sponsored by - The IT Product Guide Read honest & candid reviews on hundreds of IT Products from real users. Discover which products truly live up to the hype. Start reading now. http://ads.osdn.com/?ad_id=6595&alloc_id=14396&op=click -- _______________________________________________ Dri-devel mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/dri-devel
