[PATCH bpf-next 00/17] bpf: tracing_multi link

[Jiri Olsa <jolsa@kernel.org>]

hi,
adding tracing_multi link support that allows fast attachment
of tracing program to many functions.

RFC version: https://lore.kernel.org/bpf/20260203093819.2105105-1-jolsa@kernel.org/

Changes to RFC:
- added ftrace_hash_count as wrapper for hash_count [Steven]
- added trampoline mutex pool [Andrii]
- reworked 'struct bpf_tramp_node' separatoin [Andrii]
  - the 'struct bpf_tramp_node' now holds pointer to bpf_link,
    which is similar to what we do for uprobe_multi;
    I understand it's not a fundamental change compared to previous
    version which used bpf_prog pointer instead, but I don't see better
    way of doing this.. I'm happy to discuss this further if there's
    better idea
- reworked 'struct bpf_fsession_link' based on bpf_tramp_node
- made btf__find_by_glob_kind function internal helper [Andrii]
- many small assorted fixes [Andrii,CI]
- added session support [Leon Hwang]
- added cookies support
- added more tests

Note I plan to send linkinfo/fdinfo support separately.

TODO: add rollback tests, add f*.multi.s tests, add trigger bench

---
Jiri Olsa (17):
      ftrace: Add ftrace_hash_count function
      bpf: Use mutex lock pool for bpf trampolines
      bpf: Add struct bpf_trampoline_ops object
      bpf: Add struct bpf_tramp_node object
      bpf: Factor fsession link to use struct bpf_tramp_node
      bpf: Add multi tracing attach types
      bpf: Add bpf_trampoline_multi_attach/detach functions
      bpf: Add support for tracing multi link
      bpf: Add support for tracing_multi link cookies
      bpf: Add support for tracing_multi link session
      libbpf: Add support to create tracing multi link
      selftests/bpf: Add tracing multi skel/pattern/ids attach tests
      selftests/bpf: Add tracing multi intersect tests
      selftests/bpf: Add tracing multi cookies test
      selftests/bpf: Add tracing multi session test
      selftests/bpf: Add tracing multi attach fails test
      selftests/bpf: Add tracing multi attach benchmark test

 arch/arm64/net/bpf_jit_comp.c                                      |  58 ++++-----
 arch/s390/net/bpf_jit_comp.c                                       |  42 +++---
 arch/x86/net/bpf_jit_comp.c                                        |  54 ++++----
 include/linux/bpf.h                                                |  87 +++++++++----
 include/linux/bpf_types.h                                          |   1 +
 include/linux/ftrace.h                                             |   1 +
 include/linux/trace_events.h                                       |   6 +
 include/uapi/linux/bpf.h                                           |   9 ++
 kernel/bpf/bpf_struct_ops.c                                        |  27 ++--
 kernel/bpf/btf.c                                                   |   4 +
 kernel/bpf/syscall.c                                               |  91 ++++++++-----
 kernel/bpf/trampoline.c                                            | 457 ++++++++++++++++++++++++++++++++++++++++++++++++++++------------
 kernel/bpf/verifier.c                                              |  26 +++-
 kernel/trace/bpf_trace.c                                           | 120 ++++++++++++++++-
 kernel/trace/ftrace.c                                              |   7 +-
 net/bpf/bpf_dummy_struct_ops.c                                     |  14 +-
 net/bpf/test_run.c                                                 |   3 +
 tools/include/uapi/linux/bpf.h                                     |  10 ++
 tools/lib/bpf/bpf.c                                                |   9 ++
 tools/lib/bpf/bpf.h                                                |   5 +
 tools/lib/bpf/libbpf.c                                             | 200 ++++++++++++++++++++++++++++
 tools/lib/bpf/libbpf.h                                             |  15 +++
 tools/lib/bpf/libbpf.map                                           |   1 +
 tools/testing/selftests/bpf/Makefile                               |   7 +-
 tools/testing/selftests/bpf/prog_tests/tracing_multi.c             | 595 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 tools/testing/selftests/bpf/progs/tracing_multi_attach.c           |  26 ++++
 tools/testing/selftests/bpf/progs/tracing_multi_bench.c            |  13 ++
 tools/testing/selftests/bpf/progs/tracing_multi_check.c            | 165 ++++++++++++++++++++++++
 tools/testing/selftests/bpf/progs/tracing_multi_intersect_attach.c |  42 ++++++
 tools/testing/selftests/bpf/progs/tracing_multi_session_attach.c   |  27 ++++
 30 files changed, 1874 insertions(+), 248 deletions(-)
 create mode 100644 tools/testing/selftests/bpf/prog_tests/tracing_multi.c
 create mode 100644 tools/testing/selftests/bpf/progs/tracing_multi_attach.c
 create mode 100644 tools/testing/selftests/bpf/progs/tracing_multi_bench.c
 create mode 100644 tools/testing/selftests/bpf/progs/tracing_multi_check.c
 create mode 100644 tools/testing/selftests/bpf/progs/tracing_multi_intersect_attach.c
 create mode 100644 tools/testing/selftests/bpf/progs/tracing_multi_session_attach.c