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Patent Title: Virtual storage computer system having methods and apparatus for providing token-controlled access to protected pages of memory via a token-accessible view

Assignee: IBM
Patent Number: US5628023
Issue Date: 05-06-1997
Application Number:
File Date:12-27-1994

Abstract: A virtual storage computer system having token controlled storage protection. The computer system includes a processor, a real storage, and a virtual storage containing a user space and a system space. A virtual storage area in the user space provides a protected view of one or more pages of memory located in the real storage. A virtual storage area in the system space provides a token-accessible view of the corresponding pages of memory. To protect the pages of memory, a user program first requests that token controlled protection be provided via the virtual address in the user space and that a corresponding user token be returned by the processor. The user program stores the user token for later use when accessing the protected pages. When the user program requests access to the protected pages, the processor matches the user token with a system token to obtain a token-accessible view in the system space of the protected pages.


Link to USPTO

IBM Pledge dated 1/11/2005