[PATCH bpf-next 0/6] Provide bpf_for() and bpf_for_each() by libbpf

[Andrii Nakryiko <andrii@kernel.org>]

This patch set moves bpf_for(), bpf_for_each(), and bpf_repeat() macros from
selftests-internal bpf_misc.h header to libbpf-provided bpf_helpers.h header.
To do this in a way to allow users to feature-detect and guard such
bpf_for()/bpf_for_each() uses on old kernels we also extend libbpf to improve
unresolved kfunc calls handling and reporting. This lets us mark
bpf_iter_num_{new,next,destroy}() declarations as __weak, and thus not fail
program loading outright if such kfuncs are missing on the host kernel.

Patches #1 and #2 do some simple clean ups and logging improvements. Patch #3
adds kfunc call poisoning and log fixup logic and is the hear of this patch
set, effectively. Patch #4 adds selftest for this logic. Patches #4 and #5
move bpf_for()/bpf_for_each()/bpf_repeat() into bpf_helpers.h header and mark
kfuncs as __weak to allow users to feature-detect and guard their uses.

Andrii Nakryiko (6):
  libbpf: misc internal libbpf clean ups around log fixup
  libbpf: report vmlinux vs module name when dealing with ksyms
  libbpf: improve handling of unresolved kfuncs
  selftests/bpf: add missing __weak kfunc log fixup test
  libbpf: move bpf_for(), bpf_for_each(), and bpf_repeat() into
    bpf_helpers.h
  libbpf: mark bpf_iter_num_{new,next,destroy} as __weak

 tools/lib/bpf/bpf_helpers.h                   | 103 +++++++++++++++++
 tools/lib/bpf/libbpf.c                        | 107 ++++++++++++++----
 .../selftests/bpf/prog_tests/log_fixup.c      |  31 +++++
 tools/testing/selftests/bpf/progs/bpf_misc.h  | 103 -----------------
 .../selftests/bpf/progs/test_log_fixup.c      |  10 ++
 5 files changed, 232 insertions(+), 122 deletions(-)

-- 
2.34.1