[$] Security requirements for new kernel features

The relatively new io_uring subsystem haschanged the way asynchronous I/O is done on Linux systems and improvedperformance significantly. It has also, however, begun to run up a recordof disagreements with the kernel's security community. A recentdiscussion about security hooks for the new uring_cmd mechanismshows how easily requirements can be overlooked in a complex system with nooverall supervision.