Ringmaster: How to juggle high-throughput host OS system calls from TrustZone TEEs

2026-01-23

AI Summary

This work addresses the challenge of enabling secure, real-time access to rich operating system services in safety-critical systems, where conventional isolation mechanisms often impede such interaction. To this end, the authors propose Ringmaster, a novel framework that, for the first time, allows a TrustZone-based Trusted Execution Environment (TEE) on ARM platforms to asynchronously invoke host OS services via Linux io_uring while maintaining resilience through a lightweight kernel and essential drivers in the event of OS failure. Ringmaster supports execution of unmodified, large-scale applications as enclaves, achieving both strong security guarantees and high-efficiency collaboration. Experimental evaluation on a Raspberry Pi 4B demonstrates enclave data throughput approaching 1 GiB/s, with only 0–3% performance overhead compared to non-enclave tasks, and the framework has been successfully deployed in a drone safety system.

Technology Category

• Application Domains: Security
• Machine Learning: Hardware-aware ML
• Natural Language Processing: Safety and Robustness

Application Category

• Security and Privacy: Large-scale security measurements
• Systems and Infrastructure for Web, Mobile and WoT: Web performance, measurement, and characterization
• Responsible Web: Machine-in-the-loop, human agency and autonomy

Abstract

Many safety-critical systems require timely processing of sensor inputs to avoid potential safety hazards. Additionally, to support useful application features, such systems increasingly have a large rich operating system (OS) at the cost of potential security bugs. Thus, if a malicious party gains supervisor privileges, they could cause real-world damage by denying service to time-sensitive programs. Many past approaches to this problem completely isolate time-sensitive programs with a hypervisor; however, this prevents the programs from accessing useful OS services. We introduce Ringmaster, a novel framework that enables enclaves or TEEs (Trusted Execution Environments) to asynchronously access rich, but potentially untrusted, OS services via Linux's io_uring. When service is denied by the untrusted OS, enclaves continue to operate on Ringmaster's minimal ARM TrustZone kernel with access to small, critical device drivers. This approach balances the need for secure, time-sensitive processing with the convenience of rich OS services. Additionally, Ringmaster supports large unmodified programs as enclaves, offering lower overhead compared to existing systems. We demonstrate how Ringmaster helps us build a working highly-secure system with minimal engineering. In our experiments with an unmanned aerial vehicle, Ringmaster achieved nearly 1GiB/sec of data into enclave on a Raspberry Pi4b, 0-3% throughput overhead compared to non-enclave tasks.

Problem

• Trusted Execution Environment
• real-time processing
• OS service access
• security isolation
• denial of service

Innovation

• Trusted Execution Environment
• io_uring
• TrustZone
• asynchronous system calls
• real-time security