Today libbpf documents single-kprobe attach through func_name, with an
optional offset. For the PMU-based path, func_name = NULL with an
absolute address in offset already works as well, but that is not
described in the API.

This patchset clarifies this behavior. The first commit adds kprobe API
comments for the raw-address form and rejects it explicitly for legacy
tracefs/debugfs kprobes. The second commit adds PERF and LINK selftests
for the raw-address form, and checks that LEGACY rejects it.

---
Changes in v5:
- Add kprobe API docs, use -EOPNOTSUPP, and switch selftests to LIBBPF_OPTS

Changes in v4:
- Inline raw-address error formatting and remove the probe_target buffer

Changes in v3:
- Drop bpf_kprobe_opts.addr and reuse offset when func_name is NULL
- Make legacy tracefs/debugfs kprobes reject the raw-address form
- Update selftests to cover PERF/LINK raw-address attach and LEGACY reject

Changes in v2:
- Fix line wrapping and indentation

Hoyeon Lee (2):
  libbpf: clarify raw-address single kprobe attach behavior
  selftests/bpf: add test for raw-address single kprobe attach

 tools/lib/bpf/libbpf.c                        | 16 ++--
 tools/lib/bpf/libbpf.h                        | 29 ++++++-
 .../selftests/bpf/prog_tests/attach_probe.c   | 82 +++++++++++++++++++
 3 files changed, 119 insertions(+), 8 deletions(-)

-- 
2.52.0