Mobile devices are significantly complex, feature-rich, and heavily customized, thus they are prone to software reliability and performance issues. This paper considers the problem of software aging in Android mobile OS, which causes the device to gradually degrade in responsiveness, and to eventually fail. We present a methodology to identify factors (such as workloads and device configurations) and resource utilization metrics that are correlated with software aging. Moreover, we performed an empirical analysis of recent Android devices, finding that software aging actually affects them. The analysis pointed out processes and components of the Android OS affected by software aging, and metrics useful as indicators of software aging to schedule software rejuvenation actions.

Bugs affecting storage device drivers include the so-called protocol violation bugs, which silently corrupt data and commands exchanged with I/O devices. Protocol violations are very difficult to prevent, since testing device driver is notoriously difficult. To address them, we present a monitoring approach for device drivers (MoIO) to detect HO protocol violations at run-time. The approach infers a model of the interactions between the storage device driver, the OS kernel, and the hardware (the device driver protocol) by analyzing execution traces. The model is then used as a reference for detecting violations in production. The approach has been designed to have a low overhead and to overcome the lack of source code and protocol documentation. We show that the approach is feasible and effective by applying it on the SATA/AHCI storage device driver of the Linux kernel, and by performing fault injection and long-running tests.

The assessment of operating systems robustness with respect to unexpected or anomalous events is a fundamental requirement for mission-critical systems. Robustness can be tested by deliberately exposing the system to erroneous events during its execution, and then analyzing the OS behavior to evaluate its ability to gracefully handle these events. Since OSs are complex and stateful systems, robustness testing needs to account for the timing of erroneous events, in order to evaluate the robust behavior of the OS under different states. This paper presents SABRINE (StAte-Based Robustness testIng of operatiNg systEms), an approach for state-aware robustness testing of OSs. SABRINE automatically extracts state models from execution traces, and generates a set of test cases that cover different OS states. We evaluate the approach on a Linux-based Real-Time Operating System adopted in the avionic domain. Experimental results show that SABRINE can automatically identify relevant OS states, and find robustness vulnerabilities while keeping low the number of test cases.