Software Black Box

Hyunmin Yoon, Minsoo Ryu

http://doi.org/10.5626/JOK.2018.45.5.416

Deterministic replay mechanisms have proved to be useful in many areas including debugging, fault tolerance, security, and postmortem analysis because they can deterministically reproduce a computer system’s execution. However, proposed full-system replay mechanisms have limited applicability because of their reliance on special hardware instrumentation or virtual machine (VM) technology. In this paper, we present a purely software-based approach to full-system replay, a software black box (SBB) that does not require either special hardware instrumentation or virtual machine technology. Our proposed SBB can deterministically replay a full software system, including both applications and the OS itself. We have implemented a prototype of SBB in an embedded RTOS on top of ARMv7 Cortex-A9 and have carried out experiments to evaluate our approach. Our experiments demonstrate that SBB can successfully reproduce subtle concurrency bugs, such as races and deadlocks that may occur both in applications and in the OS kernel. We also show that the event and data logging of SBB incurs such small performance overhead that it can be enabled permanently in the OS kernel.