PathExpander: Architectural Support for Increasing the Path Coverage of Dynamic Bug Detection

Dynamic software bug detection tools are commonly used because they leverage run-time information. However, they suffer from a fundamental limitation, the Path Coverage Problem: they detect bugs only in taken paths but not in non-taken paths. In other words, they require bugs to be exposed in the monitored execution. This paper makes one of the first attempts to address this fundamental problem with a simple hardware extension. First, we propose PathExpander , a novel design that dynamically increases the code path coverage of dynamic bug detection tools with no programmer involvement. As a program executes, PathExpander selectively executes non-taken paths in a sandbox without side effects. This enables dynamic bug detection tools to find bugs that are present in these non-taken paths and would otherwise not be detected. Second, we propose a simple hardware extension to control the huge overhead in its pure software implementation to a moderate level. To further minimize overhead, ...

• Type: Conference
• Year: 2006
• Where: MICRO
• Authors: Shan Lu, Pin Zhou, Wei Liu, Yuanyuan Zhou, Josep Torrellas
• Keywords: Bug Detection Tools, Dynamic Bug Detection, Hardware, MICRO 2006, Non-taken Paths