bpf.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Andrii Nakryiko <andrii.nakryiko@gmail.com>
To: Quentin Monnet <quentin@isovalent.com>
Cc: Alexei Starovoitov <ast@kernel.org>,
	Daniel Borkmann <daniel@iogearbox.net>,
	Andrii Nakryiko <andrii@kernel.org>,
	Networking <netdev@vger.kernel.org>, bpf <bpf@vger.kernel.org>
Subject: Re: [PATCH bpf-next v2 2/9] tools: bpftool: install libbpf headers instead of including the dir
Date: Fri, 1 Oct 2021 15:55:41 -0700	[thread overview]
Message-ID: <CAEf4BzaEN91ju5E6YUdpT07noMafMfge+8Owvq8UPvBBQxJxJg@mail.gmail.com> (raw)
In-Reply-To: <20211001110856.14730-3-quentin@isovalent.com>

On Fri, Oct 1, 2021 at 4:09 AM Quentin Monnet <quentin@isovalent.com> wrote:
>
> Bpftool relies on libbpf, therefore it relies on a number of headers
> from the library and must be linked against the library. The Makefile
> for bpftool exposes these objects by adding tools/lib as an include
> directory ("-I$(srctree)/tools/lib"). This is a working solution, but
> this is not the cleanest one. The risk is to involuntarily include
> objects that are not intended to be exposed by the libbpf.
>
> The headers needed to compile bpftool should in fact be "installed" from
> libbpf, with its "install_headers" Makefile target. In addition, there
> is one header which is internal to the library and not supposed to be
> used by external applications, but that bpftool uses anyway.
>
> Adjust the Makefile in order to install the header files properly before
> compiling bpftool. Also copy the additional internal header file
> (nlattr.h), but call it out explicitly. Build (and install headers) in a
> subdirectory under bpftool/ instead of tools/lib/bpf/. When descending
> from a parent Makefile, this is configurable by setting the OUTPUT,
> LIBBPF_OUTPUT and LIBBPF_DESTDIR variables.
>
> Also adjust the Makefile for BPF selftests, so as to reuse the (host)
> libbpf compiled earlier and to avoid compiling a separate version of the
> library just for bpftool.
>
> Signed-off-by: Quentin Monnet <quentin@isovalent.com>
> ---
>  tools/bpf/bpftool/Makefile           | 27 ++++++++++++++++-----------
>  tools/testing/selftests/bpf/Makefile |  2 ++
>  2 files changed, 18 insertions(+), 11 deletions(-)
>

Looks good, but with Makefile no one can ever be sure :) Let's see how
this works in practice...

Acked-by: Andrii Nakryiko <andrii@kernel.org>

> diff --git a/tools/bpf/bpftool/Makefile b/tools/bpf/bpftool/Makefile
> index 1fcf5b01a193..78e42963535a 100644
> --- a/tools/bpf/bpftool/Makefile
> +++ b/tools/bpf/bpftool/Makefile
> @@ -17,16 +17,16 @@ endif
>  BPF_DIR = $(srctree)/tools/lib/bpf/

[...]

> +# We need to copy nlattr.h which is not otherwise exported by libbpf, but still
> +# required by bpftool.
>  $(LIBBPF): FORCE | $(LIBBPF_OUTPUT)
> -       $(Q)$(MAKE) -C $(BPF_DIR) OUTPUT=$(LIBBPF_OUTPUT) $(LIBBPF_OUTPUT)libbpf.a
> +       $(Q)$(MAKE) -C $(BPF_DIR) OUTPUT=$(LIBBPF_OUTPUT) \
> +               DESTDIR=$(LIBBPF_DESTDIR) prefix= \
> +               $(LIBBPF_OUTPUT)libbpf.a install_headers

s/$(LIBBPF_OUTPUT)libbpf.a/$(LIBBPF)/ ?

> +       $(call QUIET_INSTALL, bpf/nlattr.h)
> +       $(Q)install -m 644 -t $(LIBBPF_INCLUDE)/bpf/ $(BPF_DIR)nlattr.h
>
>  $(LIBBPF_BOOTSTRAP): FORCE | $(LIBBPF_BOOTSTRAP_OUTPUT)
>         $(Q)$(MAKE) -C $(BPF_DIR) OUTPUT=$(LIBBPF_BOOTSTRAP_OUTPUT) \

[...]

  reply	other threads:[~2021-10-01 22:56 UTC|newest]

Thread overview: 25+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-10-01 11:08 [PATCH bpf-next v2 0/9] install libbpf headers when using the library Quentin Monnet
2021-10-01 11:08 ` [PATCH bpf-next v2 1/9] tools: bpftool: remove unused includes to <bpf/bpf_gen_internal.h> Quentin Monnet
2021-10-01 11:08 ` [PATCH bpf-next v2 2/9] tools: bpftool: install libbpf headers instead of including the dir Quentin Monnet
2021-10-01 22:55   ` Andrii Nakryiko [this message]
2021-10-01 11:08 ` [PATCH bpf-next v2 3/9] tools: resolve_btfids: install libbpf headers when building Quentin Monnet
2021-10-01 23:01   ` Andrii Nakryiko
2021-10-01 11:08 ` [PATCH bpf-next v2 4/9] tools: runqslower: " Quentin Monnet
2021-10-01 11:08 ` [PATCH bpf-next v2 5/9] bpf: preload: " Quentin Monnet
2021-10-01 11:08 ` [PATCH bpf-next v2 6/9] bpf: iterators: " Quentin Monnet
2021-10-01 23:19   ` Andrii Nakryiko
2021-10-02 20:27     ` Quentin Monnet
2021-10-02 22:11       ` Quentin Monnet
2021-10-04 19:10         ` Andrii Nakryiko
2021-10-04 21:30           ` Quentin Monnet
2021-10-05 20:03             ` Quentin Monnet
2021-10-06 17:44               ` Andrii Nakryiko
2021-10-01 11:08 ` [PATCH bpf-next v2 7/9] samples/bpf: " Quentin Monnet
2021-10-01 23:22   ` Andrii Nakryiko
2021-10-02 20:30     ` Quentin Monnet
2021-10-01 11:08 ` [PATCH bpf-next v2 8/9] samples/bpf: update .gitignore Quentin Monnet
2021-10-01 11:08 ` [PATCH bpf-next v2 9/9] selftests/bpf: better clean up for runqslower in test_bpftool_build.sh Quentin Monnet
2021-10-01 23:05 ` [PATCH bpf-next v2 0/9] install libbpf headers when using the library Andrii Nakryiko
2021-10-01 23:27   ` Andrii Nakryiko
2021-10-02 20:40   ` Quentin Monnet
2021-10-03 19:20     ` Quentin Monnet

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=CAEf4BzaEN91ju5E6YUdpT07noMafMfge+8Owvq8UPvBBQxJxJg@mail.gmail.com \
    --to=andrii.nakryiko@gmail.com \
    --cc=andrii@kernel.org \
    --cc=ast@kernel.org \
    --cc=bpf@vger.kernel.org \
    --cc=daniel@iogearbox.net \
    --cc=netdev@vger.kernel.org \
    --cc=quentin@isovalent.com \
    --subject='Re: [PATCH bpf-next v2 2/9] tools: bpftool: install libbpf headers instead of including the dir' \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).