SafeDrive: Safe and Recoverable Extensions Using Language-Based Techniques

Overview

This paper presents SafeDrive, a system for detecting and recovering from type safety violations in software extensions. SafeDrive has low overhead and requires minimal changes to existing source code. To achieve this result, SafeDrive uses a novel type system that provides finegrained isolation for existing extensions written in C. In addition, SafeDrive tracks invariants using simple wrappers for the host system API and restores them when recovering from a violation. This paper describes the experience using SafeDrive for protection and recovery of a variety of Linux device drivers. In order to apply SafeDrive to these device drivers, it had to change less than 4% of the source code. SafeDrive recovered from all 44 crashes due to injected faults in a network card driver.