ConfigFix: Interactive Configuration Conflict Resolution for the Linux Kernel

TL;DR

CONFIGFIX is a C-based tool integrated into the Linux kernel configurator that automates conflict resolution, aiding users in achieving desired configurations and supporting future research and development in kernel configuration management.

Contribution

We developed CONFIGFIX, a fully integrated, C-based conflict resolution tool for the Linux kernel configuration process, addressing a long-standing usability challenge.

Findings

Successfully integrated into the kernel configurator

Produces automated fixes for configuration conflicts

Supports kernel configuration and research efforts

Abstract

Highly configurable systems are highly complex systems, with the Linux kernel arguably being one of the most well-known ones. Since 2007, it has been a frequent target of the research community, conducting empirical studies and building dedicated methods and tools for analyzing, configuring, testing, optimizing, and maintaining the kernel in the light of its vast configuration space. However, despite a large body of work, mainly bug fixes that were the result of such research made it back into the kernel's source tree. Unfortunately, Linux users still struggle with kernel configuration and resolving configuration conflicts, since the kernel largely lacks automated support. Additionally, there are technical and community requirements for supporting automated conflict resolution in the kernel, such as, for example, using a pure C-based solution that uses only compatible third-party libraries (if any). With the aim of contributing back to the Linux community, we present CONFIGFIX, a tooling that we integrated with the kernel configurator, that is purely implemented in C, and that is finally a working solution able to produce fixes for configuration conflicts. In this experience report, we describe our experiences ranging over a decade of building upon the large body of work from research on the Linux kernel configuration mechanisms as well as how we designed and realized CONFIGFIX while adhering to the Linux kernel's community requirements and standards. While CONFIGFIX helps Linux kernel users obtaining their desired configuration, the sound semantic abstraction we implement provides the basis for many of the above techniques supporting kernel configuration, helping researchers and kernel developers.