Exploiting Intel TSX for fault-tolerant execution in safety-critical systems

Safety-critical systems demand increasing computational power, which requests high-performance embedded systems. While commercial-of-the-shelf (COTS) processors offer high computational performance for a low price, they do not provide hardware support for fault-tolerant execution. However, pure software-based fault-tolerance methods entail high design complexity and runtime overhead. In this paper, we present an efficient software/hardware-based redundant execution scheme for a COTS ×86 processor, which exploits the Transactional Synchronization Extensions (TSX) introduced with the Intel Haswell microarchitecture. Our approach extends a static binary instrumentation tool to insert fault-tolerant transactions and fault-detection instructions at function granularity. TSX hardware support is used for error containment and recovery. The average runtime overhead for selected SPEC2006 benchmarks was only 49% compared to a non-fault-tolerant execution.