Design and implementation of a kernel resource protector for robustness of Linux module programming

Abstract

Loadable kernel modules supported by Linux provides lots of benefits such as a small-sized kernel, on-demand loading, and easy software upgrading. However, since modules are executed in a privileged mode, trivial misuses in a module may cause critical system halts or deadlock situations. This paper presents a kernel resource protector which prevents kernel from faults generated by modules. The protector models the system in two objects: module object and resource object. By observing the interrelations between the two objects, the protector can detect misuses of modules and take actions to resolve the erroneous situations. Implementation study has shown that the protector can find out memory leaks wasted by modules and can reclaim leaks without degrading system performance. The proposed protector makes Linux more robust, which is required indispensably in the system equipped with NVRAM (Non Volatile RAM) such as FRAM and PRAM.