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Date: Wed, 17 Sep 2014 09:17:41 -0700
Message-ID: <CAMEtUuzaCEX9RKDBMnQBZSHdTjjidp81myfSVVi4qQqtSGgtmw@mail.gmail.com>
Subject: Re: [PATCH v11 net-next 12/12] bpf: mini eBPF library, test stubs and
 verifier testsuite
From: Alexei Starovoitov <ast@plumgrid.com>
To: Daniel Borkmann <dborkman@redhat.com>
Cc: "David S. Miller" <davem@davemloft.net>, Ingo Molnar <mingo@kernel.org>,
        Linus Torvalds <torvalds@linuxfoundation.org>,
        Andy Lutomirski <luto@amacapital.net>,
        Steven Rostedt <rostedt@goodmis.org>,
        Hannes Frederic Sowa <hannes@stressinduktion.org>,
        Chema Gonzalez <chema@google.com>, Eric Dumazet <edumazet@google.com>,
        Peter Zijlstra <a.p.zijlstra@chello.nl>,
        Pablo Neira Ayuso <pablo@netfilter.org>,
        "H. Peter Anvin" <hpa@zytor.com>,
        Andrew Morton <akpm@linuxfoundation.org>,
        Kees Cook <keescook@chromium.org>,
        Linux API <linux-api@vger.kernel.org>,
        Network Development <netdev@vger.kernel.org>,
        LKML <linux-kernel@vger.kernel.org>
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On Wed, Sep 17, 2014 at 12:16 AM, Daniel Borkmann <dborkman@redhat.com> wrote:
>
>
> That actually still doesn't answer my question why the test stub
> cannot live in lib/test_bpf where we have our actual testing
> framework for eBPF/BPF, also since you exactly only build test_stub.c
> when TEST_BPF is enabled which is the Kconfig for lib/test_bpf.

multiple reasons:
1.
lib/test_bpf.c is a module, whereas test_stub.c is kernel builtin.

2.
I wasn't sure that reusing CONFIG_TEST_BPF for this
purpose was a good idea. May be it's better to introduce
CONFIG_BPF_VERIFIER_TEST_STUBS or something.

3.
kernel/bpf/test_stubs.c can be removed once real tracing
or socket use case is in.