rust-ebpf_skill

Overview

This skill provides expert guidance for designing, writing, and debugging eBPF programs and kernel-adjacent components using Rust and Aya. It focuses on safe loading, map management, XDP/tracepoint/kprobe programs, tail calls, and performance tuning. The content is practical and centered on real-world diagnostics and optimization for production systems.

How this skill works

The skill inspects eBPF program structure, map usage, and user-space loader interactions, and recommends fixes for verifier failures, performance hotspots, and unsafe patterns. It analyzes common Aya idioms (XDP, tracepoints, kprobes, per-CPU maps, program arrays) and suggests concrete code-level changes, map layouts, and loading/attachment procedures. It also proposes performance optimizations like bulk map access, tail call usage limits, and PerCPU counters.

When to use it

• Building or porting eBPF programs in Rust with Aya
• Diagnosing verifier errors, load/attach failures, or kernel crashes
• Optimizing packet processing (XDP) or tracing pipelines for latency and throughput
• Designing map layouts for perf-sensitive counters or shared configuration
• Implementing safe user-space loaders and runtime map updates

Best practices

• Prefer Aya abstractions and Rust types to reduce unsafe code and verifier surprises
• Use PerCPU maps for high-frequency counters to avoid contention
• Batch map reads and writes in user space to minimize syscalls
• Keep tail call chains short and deterministic; validate program array indices
• Prefer arrays for fixed-index lookups and hash maps only for sparse keys
• Test eBPF programs in a controlled environment before wide deployment to avoid kernel impact

Example use cases

• High-performance packet counting with an XDP program and PerCPU maps
• Chaining parsers and filters via tail calls for modular packet pipelines
• Tracing syscalls with tracepoints and correlating with user-space maps
• Instrumenting tcp_v4_connect with kprobe/kretprobe to measure connect latency
• Runtime-controlled feature flags via Array or Hash map updated by a user-space loader