Sentry: light-weight auxiliary memory access control

Light-weight, flexible access control, which allows software to regulate reads and writes to any granularity of memory region, can help improve the reliability of today’s multi-module multiprogrammer applications, as well as the efficiency of software debugging tools. Unfortunately, access control in today’s processors is tied to support for virtual memory, making its use both heavy weight and coarse grain. In this paper, we propose Sentry, an auxiliary level of virtual memory tagging that is entirely subordinate to existing virtual memory-based protection mechanisms and can be manipulated at the user level. We implement these tags in a complexity-effective manner using an M-cache (metadata cache) structure that only intervenes on L1 misses, thereby minimizing changes to the processor core. Existing cache coherence states are repurposed to implicitly validate permissions for L1 hits. Sentry achieves its goal of flexible and light-weight access control without disrupting existin...

• Type: Conference
• Year: 2010
• Where: ISCA
• Authors: Arrvindh Shriraman, Sandhya Dwarkadas
• Keywords: Access Control, Hardware, ISCA 2010, Memory Regions, Virtual Memory