linux/include/uapi
Quentin Monnet ad4a522349 bpf: add documentation for eBPF helpers (01-11)
Add documentation for eBPF helper functions to bpf.h user header file.
This documentation can be parsed with the Python script provided in
another commit of the patch series, in order to provide a RST document
that can later be converted into a man page.

The objective is to make the documentation easily understandable and
accessible to all eBPF developers, including beginners.

This patch contains descriptions for the following helper functions, all
written by Alexei:

- bpf_map_lookup_elem()
- bpf_map_update_elem()
- bpf_map_delete_elem()
- bpf_probe_read()
- bpf_ktime_get_ns()
- bpf_trace_printk()
- bpf_skb_store_bytes()
- bpf_l3_csum_replace()
- bpf_l4_csum_replace()
- bpf_tail_call()
- bpf_clone_redirect()

v4:
- bpf_map_lookup_elem(): Add "const" qualifier for key.
- bpf_map_update_elem(): Add "const" qualifier for key and value.
- bpf_map_lookup_elem(): Add "const" qualifier for key.
- bpf_skb_store_bytes(): Clarify comment about invalidated verifier
  checks.
- bpf_l3_csum_replace(): Mention L3 instead of just IP, and add a note
  about bpf_csum_diff().
- bpf_l4_csum_replace(): Mention L4 instead of just TCP/UDP, and add a
  note about bpf_csum_diff().
- bpf_tail_call(): Bring minor edits to description.
- bpf_clone_redirect(): Add a note about the relation with
  bpf_redirect(). Also clarify comment about invalidated verifier
  checks.

v3:
- bpf_map_lookup_elem(): Fix description of restrictions for flags
  related to the existence of the entry.
- bpf_trace_printk(): State that trace_pipe can be configured. Fix
  return value in case an unknown format specifier is met. Add a note on
  kernel log notice when the helper is used. Edit example.
- bpf_tail_call(): Improve comment on stack inheritance.
- bpf_clone_redirect(): Improve description of BPF_F_INGRESS flag.

Cc: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Quentin Monnet <quentin.monnet@netronome.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-04-27 00:21:58 +02:00
..
asm-generic Merge branch 'parisc-4.17-2' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux 2018-04-12 17:07:04 -07:00
drm Linux 4.16-rc7 2018-03-28 14:30:41 +10:00
linux bpf: add documentation for eBPF helpers (01-11) 2018-04-27 00:21:58 +02:00
misc ocxl: Add get_metadata IOCTL to share OCXL information to userspace 2018-03-02 13:02:14 +11:00
mtd License cleanup: add SPDX license identifier to uapi header files with a license 2017-11-02 11:20:11 +01:00
rdma IB/mlx5: Device memory support in mlx5_ib 2018-04-05 13:04:49 -06:00
scsi License cleanup: add SPDX license identifier to uapi header files with a license 2017-11-02 11:20:11 +01:00
sound ASoC: soc-generic-dmaengine-pcm: Fix sparse warnings 2018-02-26 11:05:12 +00:00
video License cleanup: add SPDX license identifier to uapi header files with a license 2017-11-02 11:20:11 +01:00
xen License cleanup: add SPDX license identifier to uapi header files with a license 2017-11-02 11:20:11 +01:00