From mboxrd@z Thu Jan  1 00:00:00 1970
From: Jakub Kicinski <jakub.kicinski@netronome.com>
Subject: Re: [RFC PATCH net-next] tools/bpftool: use version from the kernel
 source tree
Date: Wed, 20 Dec 2017 12:29:21 -0800
Message-ID: <20171220122921.62e10f33@cakuba.netronome.com>
References: <20171220201943.24440-1-guro@fb.com>
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Cc: <netdev@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
        <kernel-team@fb.com>, <scientist@fb.com>,
        Alexei Starovoitov <ast@kernel.org>,
        Daniel Borkmann <daniel@iogearbox.net>
To: Roman Gushchin <guro@fb.com>
Return-path: <linux-kernel-owner@vger.kernel.org>
In-Reply-To: <20171220201943.24440-1-guro@fb.com>
Sender: linux-kernel-owner@vger.kernel.org
List-Id: netdev.vger.kernel.org

On Wed, 20 Dec 2017 20:19:43 +0000, Roman Gushchin wrote:
> Bpftool determines it's own version based on the kernel
> version, which is picked from the linux/version.h header.
> 
> It's strange to use the version of the installed kernel
> headers, and makes much more sense to use the version
> of the actual source tree, where bpftool sources are.
> 
> This patch adds $(srctree)/usr/include to the list
> of include files, which causes bpftool to use the version
> from the source tree.
> 
> Example:
> before:
> 
> $ bpftool version
> bpftool v4.14.6
> 
> after:
> $ bpftool version
> bpftool v4.15.0

Thanks for the patch, this would indeed use some improvement.

How about we just run make to get the version like liblockdep does?

LIBLOCKDEP_VERSION=$(shell make --no-print-directory -sC ../../.. kernelversion)

probably s@../../..@$(srctree)@

$(srctree)/usr/include is not going to be there for out-of-source builds.

> Signed-off-by: Roman Gushchin <guro@fb.com>
> Cc: Jakub Kicinski <jakub.kicinski@netronome.com>
> Cc: Alexei Starovoitov <ast@kernel.org>
> Cc: Daniel Borkmann <daniel@iogearbox.net>
> ---
>  tools/bpf/bpftool/Makefile | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
> 
> diff --git a/tools/bpf/bpftool/Makefile b/tools/bpf/bpftool/Makefile
> index 9c089cfa5f3f..6864d416c49e 100644
> --- a/tools/bpf/bpftool/Makefile
> +++ b/tools/bpf/bpftool/Makefile
> @@ -37,7 +37,9 @@ CC = gcc
>  
>  CFLAGS += -O2
>  CFLAGS += -W -Wall -Wextra -Wno-unused-parameter -Wshadow
> -CFLAGS += -D__EXPORTED_HEADERS__ -I$(srctree)/tools/include/uapi -I$(srctree)/tools/include -I$(srctree)/tools/lib/bpf -I$(srctree)/kernel/bpf/
> +CFLAGS += -D__EXPORTED_HEADERS__ -I$(srctree)/tools/include/uapi
> +CFLAGS += -I$(srctree)/tools/include -I$(srctree)/tools/lib/bpf
> +CFLAGS += -I$(srctree)/kernel/bpf/ -I$(srctree)/usr/include
>  LIBS = -lelf -lbfd -lopcodes $(LIBBPF)
>  
>  INSTALL ?= install