The kdbuswreck

So if the major bone of contention is whether to transmit metadata about the message sender with the kdbus message, how about this approach:
1) Make sure the kdbus user space-kernel API handles message metadata in an extensible way
2) Merge kdbus without providing any message sender metadata
3) Separately, create a patch to add the sender metadata back in, pursue merging that separately

It looks to me like the kdbus patch would still be useful even without this metadata functionality, so it would make sense to try to get kdbus w/o metadata merged now, then look at adding metadata later.