Abstract:

The kernel security of operating systems is the foundation of the security of computer and information systems. Device drivers are considered to be the main source of kernel bugs because they account for more than 50% of kernel codes. Moreover, device drivers always run in kernel-space with system level permission, and the system completely trusts the codes running in kernel-space. So, if some bugs or malicious codes exist in device drivers, it could affect the safety of operating systems, and even render the whole system collapse. In order to prevent such failure caused by device drivers, moving part or whole codes of device drivers to user space becomes one of the effective ways to limit and isolate the vulnerability of device drivers. However, it will be a time consuming task because device drivers are various and complicated and closely related to other modules of kernels. Based on the final goal of automated split and migration, this paper attempts to construct unified and standardized communication architecture, to explore scientific policies about migrated functions within device drivers, to design framework for both user space part and kernel space part of the migrated functions, and to extract basic non-kernel migration operations. Corresponding prototypes are implemented and test results show that communication mechanisms and non-kernel solutions for device drivers in this paper are effective and less overloaded.

Key words: security of operating systems, non-kernel device drivers, kernel space, user space, communication mechanism