Subject: Re: [RFC PATCH net-next] tools/bpftool: use version from the kernel
 source tree
To: Roman Gushchin <guro@fb.com>, <netdev@vger.kernel.org>
CC: <linux-kernel@vger.kernel.org>, <kernel-team@fb.com>,
        <scientist@fb.com>, Jakub Kicinski <jakub.kicinski@netronome.com>,
        Alexei Starovoitov <ast@kernel.org>,
        Daniel Borkmann <daniel@iogearbox.net>
References: <20171220201943.24440-1-guro@fb.com>
From: Yonghong Song <yhs@fb.com>
Message-ID: <1fa179c1-4725-7e37-b5a9-5d7d8d36a37a@fb.com>
Date: Wed, 20 Dec 2017 12:26:30 -0800
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On 12/20/17 12:19 PM, 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
> 
> 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

-I$(srctree)/usr/include may not work if build directory is not the same 
as the source directory. You probably should use
-I$(objtree)/usr/include?

>   LIBS = -lelf -lbfd -lopcodes $(LIBBPF)
>   
>   INSTALL ?= install
>