WG211/M11Lawall

Automatic Generation of a Debugging Interface to the Linux Kernel by Julia Lawall

 The Linux kernel does not export a stable, well-defined kernel interface,
 complicating the development of kernel-level services, such as device
 drivers and file systems.  While there does exist a set of functions that
 are exported to external modules, these frequently change, and have
 implicit, ill-documented preconditions.  However, no specific debugging
 support is provided.

 We present Diagnosys, an approach to automatically
 constructing a debugging interface for the Linux kernel.  First, a
 designated kernel maintainer uses Diagnosys to identify constraints on
 the use of the exported functions.  Based on this information, service
 developers can then use Diagnosys to generate a debugging interface
 specialized to their code.  When a service including this interface is
 tested, it records information about potential problems. This information
 is preserved following a kernel crash or hang.
 Our experiments show that the generated debugging interface provides
 useful log information and incurs a low performance penalty.

Joint work with Tegawend\'e F. Bissyand\'e, Laurent R\'eveill\`ere and Gilles Muller