Contribution Guidelines

Quick steps for opening issues and pull requests plus the code and text licenses.

We’re happy you want to make Engineering Everything with eBPF better.
The steps below keep changes smooth and easy.

  1. Open an issue first

    • Create a GitHub issue for typos, unclear text, new examples, or bugs in sample code.
    • Show what you saw and what you expect instead. Screenshots or terminal output help a lot.

  2. Fork the repo and create a branch

    • Fork, then name your branch clearly—­for example fix-ringbuf-example or add-cgroup-section.

  3. Write in the same simple style

    • Short sentences, plain English.
    • Use fenced code blocks (```c for C, ```bash for shell).
    • Wrap Markdown lines at about 80 characters so diffs stay readable.

  4. Test what you add

    • All examples must build and run on at least Linux 6.12.22, Clang/LLVM 17, and libbpf 1.5—or newer.
    • If you change existing code, run it to confirm the output still matches the book.
    • Add a short comment showing expected output if it helps readers verify success.

  5. Open a pull request

    • Reference the related issue (for example, Fixes #123).
    • In the PR description, explain why you made the change and how you tested it.
    • CI checks will compile the code and build the book; please wait for them to pass.

  6. Review process

    • We aim to review within a week. Friendly suggestions are normal—feel free to ask for clarification.
    • Once approved, a maintainer will merge and include your name in the release notes.

  7. Licensing

    • Kernel eBPF source files
      • If the file contains 
        char LICENSE[] SEC("license") = "GPL";
        it is contributed under GPL-2.0-or-later so it can use GPL-only helpers.
      • You may instead set the string to "BSD", "MIT", or any SPDX-compatible identifier if you prefer a more permissive license.
        • Important: the kernel will then not allow GPL-only helpers; choose this path only if your code does not need them.
        • State your chosen license in the file header so readers know the terms.
    • User-space loaders, scripts, and utilities are Apache 2.0 by default (mention in the header if you prefer GPL).
    • Book text and diagrams remain Creative Commons BY 4.0.

  8. Code of Conduct

    • We follow the Contributor Covenant v2.1. Please be respectful, patient, and welcoming. That’s it! Thank you for helping more people engineer everything with eBPF.