Limitations of the Linux Fault Injection Framework to Test Direct Memory Access Address Errors

Device drivers can be traced as the source of most operating system (OS) bugs. The Linux kernel includes a fault injection framework which developers can use to implement simple fault injection tools to test device drivers. This paper presents our results in applying the fault injection framework to inject DMA address errors. Our experiments show that while the injected errors reach the device driver, the asynchronous nature of DMA makes the framework an ill-suited approach if the fault injection campaign expects the errors to reach the hardware I/O devices, as when trying to test IOMMU implementations.