Testing for Dynamic Software Update: An Object-State-Oriented Approach

Dynamic software update (DSU) can patch programs without stopping them. The updating process includes replacing changed code, transforming stale objects with object transformers, and resuming the execution of the updated program. However, flawed object transformers currently hinder DSU from the wide application, since they may introduce the inconsistencies between the transformed objects with expected new ones, that are created by the new program executing from scratch with the same inputs. To detect such inconsistencies, our approach first utilizes fuzzing testing to explore test inputs, then executes them over the old and new versions of a program within our specially designed parallel executor. Any inconsistency and the corresponding test will be issued. The evaluation over default transformer in 50 updates (14 of them have the inconsistency problem) showed that our approach discovered inconsistency in 16 updates, with 5 false positives and 3 false negatives. We also optimized the seed selection strategy in fuzzing process and improved the efficiency by 25.0%.