An Empirical Study of Configuration Mismatches in Linux

TL;DR

This paper investigates configuration mismatches in the Linux kernel, analyzing 80 cases to understand their types and severity, revealing that many can cause critical kernel misconfigurations.

Contribution

It provides a detailed manual analysis of configuration mismatches in Linux, categorizing issues and assessing their potential impact on kernel correctness.

Findings

Approximately two-thirds of mismatches can lead to kernel misconfigurations

Identified various categories of configuration issues

Highlights the prevalence of configuration mismatches in Linux kernels

Abstract

Ideally the variability of a product line is represented completely and correctly by its variability model. However, in practice additional variability is often represented on the level of the build system or in the code. Such a situation may lead to inconsistencies, where the actually realized variability does not fully correspond to the one described by the variability model. In this paper we focus on configuration mismatches, i.e., cases where the effective variability differs from the variability as it is represented by the variability model. While previous research has already shown that these situations still exist even today in well-analyzed product lines like Linux, so far it was unclear under what circumstances such issues occur in reality. In particular, it is open what types of configuration mismatches occur and how severe they are. Here, our contribution is to close this gap by presenting a detailed manual analysis of 80 configuration mismatches in the Linux 4.4.1 kernel and assess their criticality. We identify various categories of configuration issues and show that about two-thirds of the configuration mismatches may actually lead to kernel misconfigurations.