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arXiv · 2407.20559

Practical Rely/Guarantee Verification of an Efficient Lock for seL4 on Multicore Architectures

Robert J. Colvin·Ian J. Hayes·Scott Heiner·Peter Höfner·Larissa Meinicke·Roger C. Su
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Abstract

Developers of low-level systems code providing core functionality for operating systems and kernels must address hardware-level features of modern multicore architectures. A particular feature is pipelined "out-of-order execution" of the code as written, the effects of which are typically summarised as a "weak memory model" - a term which includes further complicating factors that may be introduced by compiler optimisations. In many cases, the nondeterminism inherent in weak memory models can be expressed as micro-parallelism, i.e., parallelism within threads and not just between them. Fortunately Jones' rely/guarantee reasoning provides a compositional method for shared-variable concurrency, whether that be in terms of communication between top-level threads or micro-parallelism within threads. In this paper we provide an in-depth verification of the lock algorithm used in the seL4 microkernel, using rely/guarantee to handle both interthread communication as well as micro-parallelism introduced by weak memory models.

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Robert J. Colvin, Ian J. Hayes, Scott Heiner, Peter Höfner, Larissa Meinicke, Roger C. Su. 2024-07-30. Practical Rely/Guarantee Verification of an Efficient Lock for seL4 on Multicore Architectures. https://arxiv.org/abs/2407.20559

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