SIRO: Empowering Version Compatibility in Intermediate Representations via Program Synthesis

This paper presents Siro, a new program transformation framework that translates between different versions of Intermediate Representations (IR), aiming to better address the issue of IR version incompatibility on IR-based software, such as static analyzers. We introduce a generic algorithm skeleton for Siro based on the divide-and-conquer principle. To minimize labor-intensive tasks of the implementation process, we further employ program synthesis to automatically generate translators for IR instructions within vast search spaces. Siro is instantiated on LLVM IR and has effectively helped to produce ten well-functioning IR translators for different version pairs, each taking less than three hours. From a practical perspective, we utilize these translators to assist static analyzers and fuzzers in reporting bugs and achieving accuracy of 91% and 95%, respectively. Remarkably, Siro has already been deployed in real-world scenarios and makes existing static analyzers available to safeguard the Linux kernel by uncovering 80 new vulnerabilities.