AI 中文总结
PRISM是用于CHERI的TEE架构，通过引入棱柱能力解决现有CHERI构建TEE的四大问题，用户空间飞地执行开销≤15%，优于Intel SGX。
AI 中文摘要
可信执行环境（TEE）可保护敏感代码和数据免受外部干扰，但缺乏固有内存安全性。CHERI能在对象级别实施空间内存安全性。利用CHERI原语构建TEE的尝试存在四个问题：（1）能力撤销操作开销大；（2）需依赖主机操作系统（OS）支持溯源跟踪和物理内存保护；（3）域转换开销大；（4）缺乏远程认证支持。我们引入棱柱能力并提出PRISM——一种用于CHERI的TEE架构，该架构利用棱柱能力创建用户空间飞地，同时解决上述挑战。PRISM将棱柱能力中的飞地“色调”（标识符）与物理内存访问控制绑定，支持O(1)复杂度的所有权建立（无需内存扫描），并能实现高效域转换，可原子性激活和停用棱柱能力。此外，PRISM支持飞地的远程认证。我们的实验表明，在PRISM中执行用户空间飞地仅产生中等开销（≤15%），相比Intel SGX下相同工作负载有显著改进。
英文摘要
Trusted execution environments (TEEs) protect sensitive code and data from external interference, but lack inherent memory safety. CHERI can enforce spatial memory safety at the object level. Attempts to establish a TEE using CHERI primitives suffer from (1) expensive capability revocation operations, (2) need to rely on the host operating system (OS) to support provenance tracking and physical memory protection, (3) expensive domain transitions, and (4) lack of support for remote attestation. We introduce prismatic capabilities and present PRISM, a TEE architecture for CHERI leveraging prismatic capabilities to create userspace enclaves while addressing these challenges. PRISM binds enclave 'hues' (identifiers) in prismatic capabilities to physical memory access controls, enables O(1) ownership establishment without memory sweeps, and supports efficient domain transitions that atomically activate and deactivate prismatic capabilities. Additionally, PRISM enables remote attestation of its enclaves. We demonstrate that execution of userspace enclaves in PRISM incurs only moderate overhead (<= 15%), a significant improvement over the same workloads under Intel SGX
