linux/tools/bpf/bpftool
Quentin Monnet 9910a74d6e bpftool: Update versioning scheme, align on libbpf's version number
Since the notion of versions was introduced for bpftool, it has been
following the version number of the kernel (using the version number
corresponding to the tree in which bpftool's sources are located). The
rationale was that bpftool's features are loosely tied to BPF features
in the kernel, and that we could defer versioning to the kernel
repository itself.

But this versioning scheme is confusing today, because a bpftool binary
should be able to work with both older and newer kernels, even if some
of its recent features won't be available on older systems. Furthermore,
if bpftool is ported to other systems in the future, keeping a
Linux-based version number is not a good option.

Looking at other options, we could either have a totally independent
scheme for bpftool, or we could align it on libbpf's version number
(with an offset on the major version number, to avoid going backwards).
The latter comes with a few drawbacks:

- We may want bpftool releases in-between two libbpf versions. We can
  always append pre-release numbers to distinguish versions, although
  those won't look as "official" as something with a proper release
  number. But at the same time, having bpftool with version numbers that
  look "official" hasn't really been an issue so far.

- If no new feature lands in bpftool for some time, we may move from
  e.g. 6.7.0 to 6.8.0 when libbpf levels up and have two different
  versions which are in fact the same.

- Following libbpf's versioning scheme sounds better than kernel's, but
  ultimately it doesn't make too much sense either, because even though
  bpftool uses the lib a lot, its behaviour is not that much conditioned
  by the internal evolution of the library (or by new APIs that it may
  not use).

Having an independent versioning scheme solves the above, but at the
cost of heavier maintenance. Developers will likely forget to increase
the numbers when adding features or bug fixes, and we would take the
risk of having to send occasional "catch-up" patches just to update the
version number.

Based on these considerations, this patch aligns bpftool's version
number on libbpf's. This is not a perfect solution, but 1) it's
certainly an improvement over the current scheme, 2) the issues raised
above are all minor at the moment, and 3) we can still move to an
independent scheme in the future if we realise we need it.

Given that libbpf is currently at version 0.7.0, and bpftool, before
this patch, was at 5.16, we use an offset of 6 for the major version,
bumping bpftool to 6.7.0. Libbpf does not export its patch number;
leave bpftool's patch number at 0 for now.

It remains possible to manually override the version number by setting
BPFTOOL_VERSION when calling make.

Signed-off-by: Quentin Monnet <quentin@isovalent.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20220210104237.11649-3-quentin@isovalent.com
2022-02-10 21:09:47 -08:00
..
bash-completion bpftool: Update the lists of names for maps and prog-attach types 2021-11-14 18:35:02 -08:00
Documentation bpftool: Add libbpf's version number to "bpftool version" output 2022-02-10 21:09:47 -08:00
skeleton tools/bpf/bpftool/skeleton: replace bpf_probe_read_kernel with bpf_probe_read_kernel_str to get task comm 2022-01-20 08:52:53 +02:00
.gitignore bpftool: Fix SPDX tag for Makefiles and .gitignore 2021-11-10 09:00:52 -08:00
btf_dumper.c bpftool: Use bpf_obj_get_info_by_fd directly 2021-11-03 11:25:32 -07:00
btf.c bpftool: Fix error check when calling hashmap__new() 2022-01-12 17:01:36 -08:00
cfg.c tools, bpftool: Poison and replace kernel integer typedefs 2020-05-11 21:20:46 +02:00
cfg.h tools: bpftool: replace Netronome boilerplate with SPDX license headers 2018-12-13 12:08:44 +01:00
cgroup.c bpftool: Adding support for BTF program names 2022-01-19 10:04:41 -08:00
common.c bpftool: Fix uninit variable compilation warning 2022-02-03 16:32:25 +01:00
feature.c bpftool: Stop supporting BPF offload-enabled feature probing 2022-02-03 16:32:25 +01:00
gen.c bpftool: Generalize light skeleton generation. 2022-02-10 23:31:51 +01:00
iter.c bpftool: Use libbpf_get_error() to check error 2021-11-14 18:38:13 -08:00
jit_disasm.c bpftool: Properly close va_list 'ap' by va_end() on error 2021-07-06 09:19:23 +02:00
json_writer.c bpftool: Support dumping metadata 2020-09-15 18:28:27 -07:00
json_writer.h bpftool: Support dumping metadata 2020-09-15 18:28:27 -07:00
link.c bpftool: Fix error check when calling hashmap__new() 2022-01-12 17:01:36 -08:00
main.c bpftool: Update versioning scheme, align on libbpf's version number 2022-02-10 21:09:47 -08:00
main.h bpftool: Adding support for BTF program names 2022-01-19 10:04:41 -08:00
Makefile bpftool: Update versioning scheme, align on libbpf's version number 2022-02-10 21:09:47 -08:00
map_perf_ring.c bpftool: Update btf_dump__new() and perf_buffer__new_raw() calls 2021-11-11 16:54:06 -08:00
map.c bpftool: Fix error check when calling hashmap__new() 2022-01-12 17:01:36 -08:00
net.c bpftool: use new API for attaching XDP program 2022-01-20 21:22:02 -08:00
netlink_dumper.c bpftool: Use consistent include paths for libbpf 2020-01-20 16:37:45 -08:00
netlink_dumper.h tools: bpftool: dual license all files 2018-12-13 12:08:44 +01:00
perf.c tools: bpftool: Update and synchronise option list in doc and help msg 2021-07-30 15:40:27 -07:00
pids.c bpftool: Fix error check when calling hashmap__new() 2022-01-12 17:01:36 -08:00
prog.c bpftool: Migrate from bpf_prog_test_run_xattr 2022-02-02 22:31:18 -08:00
struct_ops.c bpftool: Stop using bpf_map__def() API 2022-01-12 17:01:38 -08:00
tracelog.c tools: bpftool: add an option to prevent auto-mount of bpffs, tracefs 2018-12-18 14:47:17 +01:00
xlated_dumper.c bpftool: Use syscall/loader program in "prog load" and "gen skeleton" command. 2021-05-19 00:41:31 +02:00
xlated_dumper.h tools: bpftool: replace Netronome boilerplate with SPDX license headers 2018-12-13 12:08:44 +01:00