mbox series

[bpf-next,0/3] libbpf: add bulk BTF type copying API

Message ID 20211005064703.60785-1-andrii@kernel.org (mailing list archive)
Headers show
Series libbpf: add bulk BTF type copying API | expand

Message

Andrii Nakryiko Oct. 5, 2021, 6:47 a.m. UTC 
From: Andrii Nakryiko <andrii@kernel.org>

Add bulk BTF type data copying API, btf__add_btf(), to libbpf. This API is
useful for tools that are manipulating BPF, such as pahole. They abstract away
the details of implementing a pretty mundane, but important to get right,
details of handling all possible BTF kinds, as well as, importantly, adjusting
BTF type IDs and copying/deduplicating strings and string offsets, referenced
from copied BTF types.

Also, being a batch API, it's possible to improve the efficiency by
preallocating necessary memory more efficiently.

This API is going to be used by pahole to implement efficient parallelized BTF
encoding.

Cc: Arnaldo Carvalho de Melo <acme@kernel.org>

Andrii Nakryiko (3):
  libbpf: add API that copies all BTF types from one BTF object to
    another
  selftests/bpf: refactor btf_write selftest to reuse BTF generation
    logic
  selftests/bpf: test new btf__add_btf() API

 tools/lib/bpf/btf.c                           | 114 +++++++++++++-
 tools/lib/bpf/btf.h                           |  22 +++
 tools/lib/bpf/libbpf.map                      |   1 +
 .../selftests/bpf/prog_tests/btf_write.c      | 141 +++++++++++++++++-
 4 files changed, 270 insertions(+), 8 deletions(-)