[PATCH bpf-next v2 0/6] bpf: Support multi-attach for freplace programs

["Toke Høiland-Jørgensen" <toke@redhat.com>]

This series adds support attaching freplace BPF programs to multiple targets.
This is needed to support incremental attachment of multiple XDP programs using
the libxdp dispatcher model.

The first two patches are refactoring patches: The first one is a trivial change
to the logging in the verifier, split out to make the subsequent refactor easier
to read. Patch 2 refactors check_attach_btf_id() so that the checks on program
and target compatibility can be reused when attaching to a secondary location.

Patch 3 contains the change that actually allows attaching freplace programs in
multiple places. Patches 4-6 are the usual tools header updates, libbpf support
and selftest.

See the individual patches for details.

Changelog:

v2:
  - Drop the log arguments from bpf_raw_tracepoint_open
  - Fix kbot errors
  - Rebase to latest bpf-next

---

Toke Høiland-Jørgensen (6):
      bpf: change logging calls from verbose() to bpf_log() and use log pointer
      bpf: verifier: refactor check_attach_btf_id()
      bpf: support attaching freplace programs to multiple attach points
      tools: add new members to bpf_attr.raw_tracepoint in bpf.h
      libbpf: add support for supplying target to bpf_raw_tracepoint_open()
      selftests: add test for multiple attachments of freplace program


 include/linux/bpf.h                           |  23 ++-
 include/linux/bpf_verifier.h                  |   9 +
 include/uapi/linux/bpf.h                      |   6 +-
 kernel/bpf/core.c                             |   1 -
 kernel/bpf/syscall.c                          |  78 +++++++-
 kernel/bpf/trampoline.c                       |  36 +++-
 kernel/bpf/verifier.c                         | 171 ++++++++++--------
 tools/include/uapi/linux/bpf.h                |   6 +-
 tools/lib/bpf/bpf.c                           |  13 +-
 tools/lib/bpf/bpf.h                           |   9 +
 tools/lib/bpf/libbpf.map                      |   1 +
 .../selftests/bpf/prog_tests/fexit_bpf2bpf.c  | 164 ++++++++++++++---
 .../bpf/progs/freplace_get_constant.c         |  15 ++
 13 files changed, 404 insertions(+), 128 deletions(-)
 create mode 100644 tools/testing/selftests/bpf/progs/freplace_get_constant.c