40 Variability Bugs in the Linux Kernel

TR-2014-180, Authors: Iago Abal, Claus Brabrand & Andrzej Wasowski.

40 Variability Bugs in the Linux Kernel

Iago Abal

Claus Brabrand

Andrzej Wasowski

Abstract

Feature-sensitive verification is a recent field that pursues the effective analysis of the exponential number of variants of a program family. Today researchers lack examples of concrete bugs induced by variability, and occurring in real large-scale software. Such a collection of bugs is a requirement for goal-oriented research, serving to evaluate tool implementations of feature-sensitive analyses by testing them on real bugs. We present a qualitative study of 40 variability bugs collected from bug-fixing commits to the Linux kernel repository. We investigate each of the 40 bugs, recording the outcome of our analysis into a database. In addition, we provide self-contained simplified C99 versions of the bugs, facilitating understanding and tool evaluation. Our study provides insights about the nature and occurrence of variability bugs in a large C software system, and shows in what ways variability affects and increases the complexity of software bugs.

Technical report TR-2014-180 in IT University Technical Report Series, May 2014. 

Available as PDF.