Shadow state encoding for efficient monitoring of block-level properties

Abstract

Memory shadowing associates addresses from an application's memory to values stored in a disjoint memory space called shadow memory. At runtime shadow values store metadata about application memory locations they are mapped to. Shadow state encodings -- the structure of shadow values and their interpretation -- vary across different tools. Encodings used by the state-of-the-art monitoring tools have been proven useful for tracking memory at a byte-level, but cannot address properties related to memory block boundaries. Tracking block boundaries is however crucial for spatial memory safety analysis, where a spatial violation such as out-of-bounds access, may dereference an allocated location belonging to an adjacent block or a different struct member.