Privileged error detection protects safety processors with low overhead
PEEK: Heterogeneous Parallelism for Privileged Error Detection in Safety-Critical Processors
Hardware Architecture
Summary
Safety-critical processors must detect errors even when running privileged tasks, which manage sensitive system operations. Existing error detection methods don’t cover these privileged tasks well, causing performance and reliability problems. The authors designed PEEK, a new system that can check errors during privileged execution without slowing down the processor much. They tested PEEK on a real processor running Linux and showed it works efficiently with small hardware cost.
What this means in practice
- •For chip designers: Incorporate error detection for privileged software execution to maintain safety without heavy hardware cost in processor chips.
- •For embedded systems engineers: Build safety-critical processors that can robustly detect errors while running operating system kernels and privileged code in real time.
Authors
Tinglue Wang, Zhenghui Guo, Bing Guo, Jiapeng Guan, Renshuang Jiang, Jie Zhang, Jing Li, Xin Si, Sam Ainsworth, Zhe Jiang
Abstract
Heterogeneous parallel error detection architecture has been widely studied for safeguarding OoO superscalar processors in safetycritical systems, as it achieves significantly lower hardware overhead compared to traditional LockStep, by exploiting the parallelism that exists in a secondary execution. However, previous works do not cover the protection of privileged-mode execution, impeding their effectiveness in real-world deployment. Moreover, naive extension to privileged-mode can cause a litany of issues, from abysmal performance due to high synchronization costs, to full deadlocks. Here, we present PEEK, the first privileged parallel error detection architecture. Based on a deep analysis of privileged execution, we redesign the verification pipeline, addressing all the bottlenecks and bugs identified in privileged-mode protection. Evaluated using various metrics on an RTL-level full system running Linux, PEEK achieves full-privilege protection on Linux with negligible performance slowdown and affordable hardware overhead. PEEK has been taped out using a 28nm process, and its source is available at https://anonymous.4open.science/r/PEEK-3000.