It's hard to generalise like that. There are lots of flavors of cap system. On many hardware capability-based addressing systems it is easy to zap them by cle

It's hard to generalise like that. There are lots of flavors of cap system. On many hardware capability-based addressing systems it is easy to zap them by clearing the corresponding bit in the capability mask. However, the problem then becomes how to revoke a cap from some holders and not others etc (which can be done with chains and ... turns into an interesting permission-like system ;) ...) Permission-list systems have exactly the same problem too. IIRC munmap ends up walking linked lists on Linux rather like ancient heaps. It might have changed.