Kernel mode protection
US6282657A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 16, 1998 |
| Grant date | Aug 28, 2001 |
| Priority date | — |
| Expiry date | Sep 16, 2018 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L2209/12
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A protection circuit operates in a user or kernel mode. In the kernel mode, a kernel memory is accessible only by a secure kernel. A processor is reset if a security violation occurs, such as by attempting to access kernel memory in user mode. A program fetch supervisor circuit compares addresses to a predetermined address to determine if a security violation has occurred. A data fetch supervisor circuit compares data addresses to a protected memory address range. A security violation occurs if the data address is in protected memory, which resets the processor. A method of kernel mode protection includes fetching a program opcode or data operand. If the program opcode or data operand is from kernel memory and the processor is in user mode, the processor is reset. If an opcode is fetched from user memory while in kernel mode, the processor reverts to user mode.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.