Exception-Level Memory Access Control for Secure Software Isolation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional technologies fail to adequately secure important data stored in low exception levels from being accessed and tampered with by software running at high exception levels, leading to potential data leakage and security breaches.
Innovation Solution
Implementing an electronic apparatus with multiple exception levels, each corresponding to a specific physical address range, and a controller to manage access, ensuring that software can only access its designated range, and performing security protection operations when unauthorized access is detected.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If software running at high exception level can access physical address range corresponding to low exception level, then software functionality and flexibility are improved, but security and data protection deteriorate
Solution Approach 1:
The patent segments the physical address space into multiple exception levels (EL0, EL1, EL2, EL3), where each level has its own dedicated physical address range. This segmentation prevents software at higher exception levels from accessing memory spaces of lower exception levels, thereby securing sensitive data while maintaining software functionality within appropriate boundaries.
Solution Approach 2:
The patent introduces an intermediary mechanism (the exception level hierarchy with associated physical address ranges) that mediates between software needs for data access and security requirements. This intermediary structure allows controlled access patterns while preventing unauthorized access to sensitive data stored at lower exception levels.
2Reliability
If important data is stored in physical address range corresponding to low exception level, then data protection and security are improved, but software functionality and accessibility deteriorate
Solution Approach 1:
The patent segments the memory space into exception levels, placing important data in protected ranges at lower levels (EL0, EL1) while allowing software at appropriate levels to access this data through defined pathways. This maintains both security and necessary accessibility.
Solution Approach 2:
The patent applies local quality by providing different access rights and characteristics to different regions of memory based on their exception level. Sensitive data at lower exception levels has restricted access, while data at higher levels has broader access, creating localized security properties throughout the address space.
Data Source
Figure 1~2
Figure 3
Figure 4
AI summary
Embodiments of this application provide an electronic apparatus and a method for securely accessing software. The electronic apparatus includes a processor and a first controller. The processor is configured to run current software, and provide, for the first controller, a logical address of a memory to be accessed by the current software. The first controller converts the logical address into a physical address in the memory, determines whether the physical address is within a preset physical address range corresponding to a current exception level of the current software, and when the physical address is within the preset physical address range, allows the current software to access the logical address. The electronic apparatus has a plurality of exception levels, each of the plurality of exception levels reflects one privilege level, each exception level corresponds to one physical address range, and the current exception level is one of the plurality of exception levels. The electronic apparatus and the method for securely accessing software provided in embodiments of this application can improve security of running software.