I don&#x27;t think anyone is disputing that Linux has many encrusted layers of permissions systems, some of them Turing complete.  And a terrible reporting mechanism -- your system call returns -EPERM, now you have to work out which of the many layers you tripped over.  Or you can try decoding audit.log or remember which of the many SELinux tools you need to invoke.<p>The question is if we can do better, and the answer is obviously yes because research OSes have existed for many years, like EROS, KeyKOS etc.<p>However rewriting all our software is not going to happen, so the question is how to get from where we are now to better systems.