The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Oct. 01, 1985
Filed:
May. 22, 1981
Gerald F Clancy, Saratoga, CA (US);
Stephen I Schleimer, Chapel Hill, NC (US);
Craig J Mundie, Cary, NC (US);
Steven J Wallach, Saratoga, CA (US);
Richard G Bratt, Wayland, MA (US);
Edward S Gavrin, Lincoln, MA (US);
Data General Corporation, Westboro, MA (US);
Abstract
An access control system for use in a digital computer system wherein the memory system is organized into objects, a data item is locatable by specifying an object, instructions are contained in procedures, and the operations performed by the system include a call operation for suspending an execution of a procedure and commencing another execution and a return operation for terminating an execution and resuming a suspended execution. The access control system associates each procedure with a domain, i.e., a set of objects accessible to the procedure. The access control system further includes a secure stack object which is accessible only to the access control system. When a call operation commences execution of a procedure which has a different domain, the access control system responds to the call operation by storing information required to return to the current domain in the secure stack. When a return operation resumes execution of a procedure which has a different domain, the access control system responds to the call operation by using the information in the secure stack to return to the previous domain.