Android Stack Machine

Abstract

Abstract. In this paper, we propose Android Stack Machine (ASM), a formal model to capture key mechanisms of Android multi-tasking such as activities, back stacks, launch modes, as well as task affinities. The model is based on pushdown systems with multiple stacks, and focuses on the evolution of the back stack of the Android system when interacting with activities carrying specific launch modes and task affinities. For formal analysis, we study the reachability problem of ASM. While the general problem is shown to be undecidable, we identify expressive fragments for which various verification techniques for pushdown systems or their extensions are harnessed to show decidability of the problem.

Smali+: An Operational Semantics for Low-Level Code Generated from Reverse Engineering Android Applications

“…Some works have focused on other issues of Android such as multi-tasking. For instance, ASM presented in [29] is a formal model that formalizes all Android elements related to multi-tasking, such as activities, back stacks and tasks. An Android application is somewhat seen as a collection of activities with different types that interact with the user through a back stack.…”