Using SBPF to Accelerate Kernel Memory Access From Userspace

2025-06-27

AI Summary

Traditional system calls incur substantial performance overhead and microarchitectural penalties—including frequent context switches and costly cross-address-space memory copies—leading to pipeline flushes and degraded efficiency. This paper proposes a novel user-kernel communication paradigm that synergistically combines shared memory with the uBPF virtual machine: a controlled, kernel-enforced shared memory region is established between user and kernel address spaces, and uBPF-based sandboxing enables fine-grained, formally verifiable access control over shared data, enabling non-blocking, zero-copy exchanges. To our knowledge, this is the first work to deeply integrate uBPF into shared-memory access enforcement—breaking the user-kernel isolation bottleneck while preserving memory safety. Experimental evaluation across representative workloads demonstrates significant speedups over conventional system calls, achieving up to several-fold improvements in data transfer throughput and effectively mitigating microarchitectural performance degradation.

Technology Category

• Multiagent Systems: Agent Communication
• Data Mining & Knowledge Management: Scalability, Parallel & Distributed Systems
• Cognitive Modeling & Cognitive Systems: Social Cognition And Interaction

Application Category

• Security and Privacy: Large-scale security measurements
• Systems and Infrastructure for Web, Mobile and WoT: Web performance, measurement, and characterization
• User Modeling, Personalization and Recommendation: User privacy protection in personalized systems

Abstract

The cost of communication between the operating system kernel and user applications has long blocked improvements in software performance. Traditionally, operating systems encourage software developers to use the system call interface to transfer (or initiate transfer of) data between user applications and the kernel. This approach not only hurts performance at the software level due to memory copies between user space address spaces and kernel space address spaces, it also hurts system performance at the microarchitectural level by flushing processor pipelines and other microarchitectural state. In this paper, we propose a new communication interface between user applications and the kernel by setting up a shared memory region between user space applications and the kernel's address space. We acknowledge the danger in breaking the golden law of user-kernel address space isolation, so we coupled a uBPF VM (user-space BPF Virtual Machine) with shared memory to control access to the kernel's memory from the user's application. In this case, user-space programs can access the shared memory under the supervision of the uBPF VM (and the kernel's blessing of its shared library) to gain non-blocking data transfer to and from the kernel's memory space. We test our implementation in several use cases and find this mechanism can bring speedups over traditional user-kernel information passing mechanisms.

Problem

• Reducing kernel-user communication cost for performance
• Enabling safe shared memory access via uBPF VM
• Accelerating data transfer without memory copies

Innovation

• Shared memory between user and kernel space
• uBPF VM controls kernel memory access
• Non-blocking data transfer via shared library