Formal Verification of a Memory Allocation Module of Contiki with Frama-C: a Case Study

International audienceFormal verification is still rarely applied to the IoT (InternetofThings)software, whereas IoT applications tend to become increasingly popular and critical.This short paper promotes the usage of formal verification to ensure safetyand security of software in this domain. We present a successful case study ondeductive verification of a memory allocation module of Contiki, a popular open-source operating system for IoT. We present the target module, describe how thecode has been specified and proven using Frama-C, a software analysis platformfor C code, and discuss lessons learned

Proving Partial-Correctness and Invariance Properties of Transition-System Models

International audienceWe propose a deductive verification approach for proving partial-correctness and invariance properties on transition-system models. Regarding partial correctness, we gen-eralise the recently introduced formalism of Reachability Logic, currently used as a language-parametric logic for programs, to transition systems. We propose a sound and relatively complete proof system for the resulting reachability logic. The soundness of the proof system is formally established in the Coq proof assistant, and the mechanised proof provides us with a Coq-certified Reachability-Logic prover for transition-system models. The relative completeness of the proof system, although theoretical in nature, also has a practical value, as it induces a proof strategy that is guaranteed to prove all valid formulas on a given transition system. The strategy reduces partial-correctness verification to invariance verification; for the latter we propose an incremental technique in order to deal with the case-explosion problem that affects it. All these techniques were instrumental in enabling us to prove, within reasonable time and effort limits, that the nontrivial algorithm implemented in security hypervisor that we designed in earlier work meets its expected functional requirements

Actes des 14e journées sur les Approches Formelles dans l'Assistance au Développement de Logiciels

National audienceCet ouvrage présente les actes des 14èmes journées sur les Approches Formelles dans l'Assistance au Développement de Logiciels (AFADL'2015) qui se sont tenues à Bordeaux les 9 et 10 juin 2015

Rely-guarantee Reasoning about Concurrent Reactive Systems: The PiCore Framework, Languages Integration and Applications

The rely-guarantee approach is a promising way for compositional verification of concurrent reactive systems (CRSs), e.g. concurrent operating systems, interrupt-driven control systems and business process systems. However, specifications using heterogeneous reaction patterns, different abstraction levels, and the complexity of real-world CRSs are still challenging the rely-guarantee approach. This article proposes PiCore, a rely-guarantee reasoning framework for formal specification and verification of CRSs. We design an event specification language supporting complex reaction structures and its rely-guarantee proof system to detach the specification and logic of reactive aspects of CRSs from event behaviours. PiCore parametrizes the language and its rely-guarantee system for event behaviour using a rely-guarantee interface and allows to easily integrate 3rd-party languages via rely-guarantee adapters. By this design, we have successfully integrated two existing languages and their rely-guarantee proof systems without any change of their specification and proofs. PiCore has been applied to two real-world case studies, i.e. formal verification of concurrent memory management in Zephyr RTOS and a verified translation for a standardized Business Process Execution Language (BPEL) to PiCore.Comment: Submission to ACM Transactions on Programming Languages and Systems in 202

A case study on formal verification of the anaxagoros hypervisor paging system with frama-C

Conference of 20th International Workshop on Formal Methods for Industrial Critical Systems, FMICS 2015 ; Conference Date: 22 June 2015 Through 23 June 2015; Conference Code:118829International audienceCloud hypervisors are critical software whose formal verification can increase our confidence in the reliability and security of the cloud. This work presents a case study on formal verification of the virtual memory system of the cloud hypervisor Anaxagoros, a microkernel designed for resource isolation and protection. The code under verification is specified and proven in the Frama-C software verification framework, mostly using automatic theorem proving. The remaining properties are interactively proven with the Coq proof assistant. We describe in detail selected aspects of the case study, including parallel execution and counting references to pages, and discuss some lessons learned, benefits and limitations of our approach

Computer Aided Verification

The open access two-volume set LNCS 11561 and 11562 constitutes the refereed proceedings of the 31st International Conference on Computer Aided Verification, CAV 2019, held in New York City, USA, in July 2019. The 52 full papers presented together with 13 tool papers and 2 case studies, were carefully reviewed and selected from 258 submissions. The papers were organized in the following topical sections: Part I: automata and timed systems; security and hyperproperties; synthesis; model checking; cyber-physical systems and machine learning; probabilistic systems, runtime techniques; dynamical, hybrid, and reactive systems; Part II: logics, decision procedures; and solvers; numerical programs; verification; distributed systems and networks; verification and invariants; and concurrency

Computer Aided Verification

The open access two-volume set LNCS 11561 and 11562 constitutes the refereed proceedings of the 31st International Conference on Computer Aided Verification, CAV 2019, held in New York City, USA, in July 2019. The 52 full papers presented together with 13 tool papers and 2 case studies, were carefully reviewed and selected from 258 submissions. The papers were organized in the following topical sections: Part I: automata and timed systems; security and hyperproperties; synthesis; model checking; cyber-physical systems and machine learning; probabilistic systems, runtime techniques; dynamical, hybrid, and reactive systems; Part II: logics, decision procedures; and solvers; numerical programs; verification; distributed systems and networks; verification and invariants; and concurrency