SingAll: Scalable Control Flow Checking for Multi-Process Embedded Systems

Reliability concerns of embedded systems are traditionally resolved by software-based control flow checking (CFC) methods where the execution flow of the processor is monitored to detect and compensate flow violations. Traditional CFC methods may lose their efficiency when it comes to multiprocessing embedded systems. In this paper, we introduce and validate a novel flow error model for multiprocessing embedded systems. Further, we propose a holistic CFC system which performs the flow checking of the processes of interest. The proposed CFC checking introduces the concept of a single monitoring process intended to check the execution flow of as many processes as wanted within an multiprocessing embedded system. Proposed solution does not introduce any substantial overheads in performance and memory consumption. Even more important is method’s insensitivity to the number of checked processes. Our wide evaluations show the average performance overhead of 13.77%, average code-size overhead of 51.71%, and the average memory overhead of 1.95% on the Mibench benchmark suite. Results of fault injections confirm that the proposed CFC method successfully detects more than 95% of flow errors including our newly defined error model.