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Abstract—Protection of cache hierarchies from side-channel attacks is critical for building secure systems, particularly the ones using Trusted Execution Environments (TEEs). In this pa- per, we consider the problem of efficient and secure fine-grained partitioning of cache hierarchies and propose a framework, called Secure Hierarchies for TEEs (TEE-SHirT). In the context of a three-level cache system, TEE-SHirT consists of partitioned shared last-level cache, partitioned private L2 caches, and non- partitioned L1 caches that are flushed on context switches and system calls. Efficient and correct partitioning requires careful design. Towards this goal, TEE-SHirT makes three contributions: 1) we demonstrate how the hardware structures used for holding cache partitioning metadata can be effectively virtualized to avoid flushing of cache partition content on context switches and system calls; 2) we show how to support multi-threaded enclaves in TEE- SHirT, addressing the issues of coherency and consistency that arise with both intra-core and inter-core data sharing; 3) we develop a formal security model for TEE-SHirT to rigorously reason about the security of our design.
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Work in Progress: Identifying Unexpected Inter-core Interference Induced by Shared Cache
In modern real-time multicore systems, understanding and adequately managing shared caches is essential to ensure the temporal isolation of critical tasks. Recent research has identified and extensively studied the sources of unpredictability imputable to shared caches, heavily promoting techniques such as cache partitioning and internal resources management. In this article, we highlight the existence of an enigmatic source of inter-core interference: the CPU-brainfreeze. Experiments realized on a development board show that benchmarks (selected from the San-Diego Vision Benchmark Suite) can exhibit up to a 10-fold increase in their execution time. The same experiment shows that for extreme cases, the core cluster can be stalled indefinitely.
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- Award ID(s):
- 2008799
- PAR ID:
- 10332464
- Date Published:
- Journal Name:
- In Proceedings of the 27th IEEE Real-Time and Embedded Technology and Applications Symposium (RTAS 2021)
- Page Range / eLocation ID:
- 517 to 520
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Conference Paper:
- https://doi.org/10.1109/RTAS52030.2021.00066
