Separation-Logic-Based Program Verification in Coq

Abstract

In our interconnected world, software bugs can seriously compromise our safety and security. To provide adequate safety or protection, security-critical kernels (of large systems) must be functionally correct.

To ensure functional correctness of C programs, we can use Hoare logic and its extensions such as separation logic. But such correctness proofs are large and complex enough that we cannot trust them unless they are machine-checked.

This dissertation shows how we can construct machine-checked proofs of program correctness using separation logic. I answer three questions: How shall we specify our programs? How shall we prove our programs correct with respect to their specifications? How shall we mechanize such correctness proofs?

I present practical techniques for separation-logic-based program verification and demonstrate them on several examples. I introduce VST-Floyd, a tool for users to build formal C program correctness proofs in Coq using separation logic. VST-Floyd is built based on Verifiable C, a proved sound separation logic; I show how to reformulate its rules to make them practical for use in verification.