Drawing the Red Line in Java

Godmar Back and Wilson Hsieh


The Flux Research Group
University of Utah Department of Computer Science
50 Central Campus Drive, 3190 MEB, Salt Lake City, Utah 84112


Software-based protection has become a viable alternative to hardware-based protection in systems based on languages such as Java, but the absence of hardware mechanisms for protection has been coupled with an absence of a user/kernel boundary. We show why such a "red line" must be present in order for a Java virtual machine to be as effective and as reliable as an operating system. We discuss how the red line can be implemented using software mechanisms, and explain the ones we use in the Java system that we are building.

Full paper presented at and appears in Proceedings of the Seventh IEEE Workshop on Hot Topics in Operating Systems, March 1999: