SaTC: CORE: Small: Partition-Oblivious Real-Time Hierarchical Scheduling

With the advancement in modern computing and communication technologies, there is an increasing trend toward integrating many real-time applications from various vendors into a single, larger system, allowing an efficient utilization of common hardware resources. In safety-critical systems, such as avionics, automotive, industrial control systems, it is of utmost importance to provide strong isolation among the applications that require different levels of criticality in order to confine faulty operations to individual components. In particular, time partitioning is a key ingredient for a safe composition of real-time applications whose correctness highly depends on their timings. Real-time hierarchical scheduling facilitates modular reasoning about the temporal behavior of individual real-time applications by abstracting away varying behavior of other applications and, more importantly, by isolating their potential misbehavior. However, conventional time-partitioning mechanisms fail to achieve strong temporal isolation from a security viewpoint; variations in execution timings can be perceived by others, which enables illegitimate information-flow between applications that are completely isolated from each other in the utilization of CPU time. This project addresses the problem of information-flow through real-time hierarchical scheduling in such integrated software environment. The proposed work will allow such systems to employ advanced hardware and software technologies to develop high-end, real-time applications in a secure manner, dramatically improving the utility and reliability of many key components in the world’s critical infrastructure. The project includes significant curriculum development activities and outreach activities to K-12 students as well as women and minority students.This project develops a set of algorithmic solutions that make real-time partitions oblivious of others’ varying temporal behaviors -- achieving non-interference-based security among all partitions. The main challenge is that the mechanisms should be independent from particular scheduling algorithms and non-intrusive to the underlying schedulers. Hence, the project focuses on highly modular and extensible mechanisms that facilitate integration into a wide variety of existing systems without requiring complete reengineering of operating systems. Scheduling analysis techniques that can enable system designers to assess the impact of the improved information-security on the CPU utilization, as well as formal method techniques for the verification of the non-interference property in both algorithmic and implementation levels is developed. The solutions are validated on prototype real-time systems with real workload. On the education side, this project pushes new courses on real-time systems into the existing curriculum and also provides students opportunities for hands-on experience with modern real-time applications. It also aims to broaden the participation of underrepresented groups and give students a unique combination of technical training and experience in this cutting-edge field.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.