Partitioning and protecting control program function through virtual storage

Many operating systems are endowed with the ability to access every byte of addressable memory in the processor complex. Unfortunately, a control program so designed creates an exposure of the following nature: It is possible for an errant section of operating system code to unwittingly modify (and perhaps destroy) either its own storage or the storage of others. This thesis addresses this problem and discusses the design and implementation of a control program in which many such attempts at destroying storage are detected and suppressed. This is accomplished by placing separate control program functions in separate virtual storages. The thesis also expounds upon the notions of protection and security within the operating system itself, and details a quasi capability mechanism that regulates the access to shared objects and ensures the invocation of one control program function by another is authorized