| ================= | 
 | BPF Documentation | 
 | ================= | 
 |  | 
 | This directory contains documentation for the BPF (Berkeley Packet | 
 | Filter) facility, with a focus on the extended BPF version (eBPF). | 
 |  | 
 | This kernel side documentation is still work in progress. The main | 
 | textual documentation is (for historical reasons) described in | 
 | :ref:`networking-filter`, which describe both classical and extended | 
 | BPF instruction-set. | 
 | The Cilium project also maintains a `BPF and XDP Reference Guide`_ | 
 | that goes into great technical depth about the BPF Architecture. | 
 |  | 
 | The primary info for the bpf syscall is available in the `man-pages`_ | 
 | for `bpf(2)`_. | 
 |  | 
 | BPF Type Format (BTF) | 
 | ===================== | 
 |  | 
 | .. toctree:: | 
 |    :maxdepth: 1 | 
 |  | 
 |    btf | 
 |  | 
 |  | 
 | Frequently asked questions (FAQ) | 
 | ================================ | 
 |  | 
 | Two sets of Questions and Answers (Q&A) are maintained. | 
 |  | 
 | .. toctree:: | 
 |    :maxdepth: 1 | 
 |  | 
 |    bpf_design_QA | 
 |    bpf_devel_QA | 
 |  | 
 |  | 
 | Helper functions | 
 | ================ | 
 |  | 
 | * `bpf-helpers(7)`_ maintains a list of helpers available to eBPF programs. | 
 |  | 
 |  | 
 | Program types | 
 | ============= | 
 |  | 
 | .. toctree:: | 
 |    :maxdepth: 1 | 
 |  | 
 |    prog_cgroup_sockopt | 
 |    prog_cgroup_sysctl | 
 |    prog_flow_dissector | 
 |    bpf_lsm | 
 |    prog_sk_lookup | 
 |  | 
 |  | 
 | Map types | 
 | ========= | 
 |  | 
 | .. toctree:: | 
 |    :maxdepth: 1 | 
 |  | 
 |    map_cgroup_storage | 
 |  | 
 |  | 
 | Testing and debugging BPF | 
 | ========================= | 
 |  | 
 | .. toctree:: | 
 |    :maxdepth: 1 | 
 |  | 
 |    drgn | 
 |    s390 | 
 |  | 
 |  | 
 | Other | 
 | ===== | 
 |  | 
 | .. toctree:: | 
 |    :maxdepth: 1 | 
 |  | 
 |    ringbuf | 
 |  | 
 | .. Links: | 
 | .. _networking-filter: ../networking/filter.rst | 
 | .. _man-pages: https://www.kernel.org/doc/man-pages/ | 
 | .. _bpf(2): https://man7.org/linux/man-pages/man2/bpf.2.html | 
 | .. _bpf-helpers(7): https://man7.org/linux/man-pages/man7/bpf-helpers.7.html | 
 | .. _BPF and XDP Reference Guide: https://docs.cilium.io/en/latest/bpf/ |