[PATCH bpf-next v2 0/9] bpf: Add log support for tracing link_create

[Leon Hwang <leon.hwang@linux.dev>]

I'm planning to add syscall common attrs support for LINK_CREATE cmd.

This is the second series for the plan, that adds syscall common attrs
support for LINK_CREATE of tracing prog and cgroup prog.

BTW, address Andrii's review [1] in patch 5:
1. Change if (!OPTS_ZEROED(opts, iter_info_len)) to if
   (!OPTS_ZEROED(opts, log_opts)).
2. Add comment to iter_info and iter_info_len that they are
   deprecated, and use iter.info and iter.len instead.

Links:
[1] https://lore.kernel.org/bpf/CAEf4BzbW4zwL-9j8e2B6KNXVNwsfWyMSAo_RsGCqv-nu_yGhTg@mail.gmail.com/

Changes:
v1 -> v2:
* Add log_opts support for bpf_program__attach_iter() API in libbpf.
* Add test to verify the log for freplace max_ctx_offset case.
* Update a subtest to verify the log_opts in bpf_program__attach_iter()
  API.
* Add log for freplace max_ctx_offset case. (bot+bpf-ci)
* Drop unnecessary bpf_verifier.h include. (bot+bpf-ci)
* Change log to "Invalid tracing attach_type.\n" when the link
  attach_type is not prog->expected_attach_type. (bot+bpf-ci)
* Change BPF_XDP to BPF_TRACE_FEXIT in tracing link_create test.
  (bot+bpf-ci)
* Drop dead iter.len check in libbpf. (bot+bpf-ci, Sashiko)
* Add OPTS_ZEROED(opts, iter) check. (bot+bpf-ci, Sashiko)
* Swap log positions of iter_info and iter_info_len. (Sashiko)
* Update bpf_program__attach_iter() to use iter.info and iter.len.
  (Sashiko)
* v1: https://lore.kernel.org/bpf/20261109140816.5196-1-leon.hwang@linux.dev/

Leon Hwang (9):
  bpf: Add log support for tracing link_create
  bpf: Add log support for tracing_multi link_create
  bpf: Add log support for iter link_create
  bpf: Add log support for cgroup prog link_create
  libbpf: Add log_opts support for BPF_TRACE_ITER
  selftests/bpf: Verify tracing link_create logs
  selftests/bpf: Verify tracing_multi link_create logs
  selftests/bpf: Verify iter link_create logs
  selftests/bpf: Verify cgroup prog link_create logs

 include/linux/bpf-cgroup.h                    |   6 +-
 include/linux/bpf.h                           |   3 +-
 include/linux/trace_events.h                  |   7 +-
 kernel/bpf/bpf_iter.c                         |  27 +-
 kernel/bpf/cgroup.c                           |  76 +++-
 kernel/bpf/syscall.c                          |  29 +-
 kernel/trace/bpf_trace.c                      |  26 +-
 tools/lib/bpf/bpf.c                           |  23 +-
 tools/lib/bpf/bpf.h                           |   8 +
 tools/lib/bpf/libbpf.c                        |   5 +-
 tools/lib/bpf/libbpf.h                        |   3 +-
 .../selftests/bpf/prog_tests/cgroup_link.c    | 324 +++++++++++++
 .../selftests/bpf/prog_tests/iter_link.c      | 156 +++++++
 .../selftests/bpf/prog_tests/tracing_link.c   | 429 ++++++++++++++++++
 .../selftests/bpf/progs/tracing_link_ctx.c    |  17 +
 15 files changed, 1083 insertions(+), 56 deletions(-)
 create mode 100644 tools/testing/selftests/bpf/prog_tests/iter_link.c
 create mode 100644 tools/testing/selftests/bpf/prog_tests/tracing_link.c
 create mode 100644 tools/testing/selftests/bpf/progs/tracing_link_ctx.c

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2.55.0