From mboxrd@z Thu Jan  1 00:00:00 1970
From: Joel Fernandes <joelaf@google.com>
Subject: samples don't build on v4.18
Date: Tue, 14 Aug 2018 18:20:54 -0700
Message-ID: <20180815012054.GA70201@joelaf.mtv.corp.google.com>
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
To: linux-kernel@vger.kernel.org, wangnan0@huawei.com,
        netdev@vger.kernel.org, ast@kernel.org, acme@kernel.org,
        fengc@google.com
Return-path: <linux-kernel-owner@vger.kernel.org>
Content-Disposition: inline
Sender: linux-kernel-owner@vger.kernel.org
List-Id: netdev.vger.kernel.org


Hi,
When building BPF samples on v4.18, I get the following errors:

$ cd samples/bpf/
$ make

Auto-detecting system features:
...                        libelf: [ OFF ]
...                           bpf: [ OFF ]

No libelf found
Makefile:213: recipe for target 'elfdep' failed
-----------

I bissected it down to commit 5f9380572b4bb24f60cd492b1

Author: Jakub Kicinski <jakub.kicinski@netronome.com>
Date:   Thu May 10 10:24:39 2018 -0700

    samples: bpf: compile and link against full libbpf
---------

Checking out a kernel before this commit makes the samples build. Also I do
have libelf on my system.

Any thoughts on this issue?

thank you,

- Joel