Flexible and Survivable Embedded Systems

“灵活和可生存的嵌入式系统”该项目正在开发一种三层方法，通过一种结合了三个要素的策略来实现可靠、安全和可靠的软件控制：基于编译器的保护、高级安全控制器和运行时保护。该研究分为三个主要重点：控制应用程序的代码安全检查：本研究旨在利用控制应用程序的结构并开发不妨碍合法控制应用程序开发的编程限制，但促进基于编译器的关键属性（如内存安全）静态检查。这些限制以与语言无关的方式指定。这是抵御代码、数据和流程访问错误和攻击的第一道防线。一个基于LLVM编译器系统的安全编程环境的原型正在开发中，它实现了上述策略，并证明了它们在单工厂控制应用中的有效性。针对语义错误和攻击的高级安全控制器：本研究为安全控制器设计提供可靠切换控制的不变性控制方法。重点研究了系统构建在线控制软件升级安全控制器的理论和步骤。基于编译器的保护、控制器设计和运行时保护之间的相互依赖关系是一个关键问题。研究了编程限制、高级控制器设计中所需的表达性以及为静态分析无法完全检查的动态行为自动生成最少和足够的运行时断言之间的相互作用。有效的运行时保护：传统的运行时保护依赖于流程抽象和执行时间监视的广泛使用。通过代码安全检查，现在可以为大多数应用程序开发逻辑上相互保护的线程。进程抽象将仅用于不能通过编译器静态分析验证安全性的复杂模块。目标是新一代高效且容错的动态实时架构，它可以利用编译器静态分析、安全控制器和运行时监控和恢复之间的集成。实验重点是基于新框架的下一代Telelab演示设备，该设备可以测量以下内容：1)不变控制理论下稳定包络的大小和安全控制器能量的减少；2)由于编译器支持和运行时的集成，存储和CPU使用方面的运行时效率提高；3)新框架对故障和攻击的鲁棒性。

Sha, LuiCCR-0209202"Flexible and Survivable Embedded Systems" This project is developing a three-tiered approach to dependable, safe, and secure software control through a strategy that combines three elements: compiler-based protection, advanced safety controllers, and runtime protection. The research is organized into three majre emphases:Code Safety Checks for Control Applications: This research seeks to exploit the structure of control applications and develop programming restrictions that do not hinder the development of legitimate control applications, but facilitate compiler based static checks for critical properties such as memory safety. The restrictions are specified in a language-independent manner. This is the first line of defense against code, data and process access faults and attacks. A prototype of a secure programming environment based on the LLVM compiler system is being developed that implements the above strategies and demonstrates their effectiveness for single plant control applications.Advanced Safety Controllers against Semantic Faults and Attacks: This research is developing the Invariance Control Method for reliable switching control for safety controller designs. The focus is theory and procedures for systematically constructing safety controllers for online control software upgrade. The inter-dependency between compiler based protection, controller designs and runtime protections is a key concern. The inter-play is studied between programming restrictions, the expressiveness needed in the design of advanced controllers, and automatic generation of minimal and sufficient runtime assertions for dynamic behaviors that cannot be completely checked by static analysis.Efficient Runtime Protections: Traditional runtime protections rely on the extensive use of the process abstraction and execution time monitoring. With code safety checks, it is now possible to develop threads that are logically protected from each other for most applications. The process abstraction will be used only for complex modules whose safety cannot be verified by compiler static analysis. The goal is a new generation of efficient and fault tolerant dynamic real time architectures that can capitalize on the integration between compiler static analysis, safety controller and runtime monitoring and recovery. Experimentation focuses on the next generation Telelab demonstration facility, based on the new framework, that can measure the following: 1) the size of the stability envelope and the reduction of safety controller energy under the theory of invariance control; 2) the runtime efficiency gain in storage and in CPU usage resulted from the integration of complier support and runtime; 3) the robustness against faults and attacks of this new framework.