Page granular curtained memory via mapping control
View Patent ↗Methods of providing and limiting access to trusted memory are provided. Trusted memory pages are not mapped with page map pages. When a central processor is operated in a page-mapping mode, access to the trusted memory is limited. In particular, without mapping information, software and hardware modules cannot access and modify the contents of trusted memory sections.
1. A method of restricting access to memory, the method comprising:
storing data in a memory location;
determining whether the data is trusted or non-trusted data;
mapping the memory location with at least one page map page stored in a non-trusted memory section only when the data is non-trusted data; and
storing entries in the at least one page map page in read only format.
2. The method of claim 1 , further including:
declaring a security violation when an attempt is made to write data to a read only page map page entry.
3. The method of claim 2 , further including:
aborting the attempt when the attempt is not a legal operation.
4. A computer-readable medium contain computer-executable instructions for causing a computer device to perform the steps comprising:
storing data in a memory location;
determining whether the data is trusted or non-trusted data; and
mapping the memory location with at least one page map page stored in a non-trusted memory section only when the data is non-trusted data, further including computer-executable instructions for causing the computer device to perform the step comprising:
configuring a processor that controls access to the at least one page map page to run in a page-mapping mode, further including computer-executable instructions for causing the computer device to perform the step comprising:
storing entries in the at least one page map page in read only format.
5. The computer-readable medium of claim 4 , further including computer-executable instructions for causing the computer device to perform the step comprising:
declaring a security violation when an attempt is made to write data to a read only page map page entry.