Date: Tue, 7 Jul 2015 12:18:40 -0700
From: Alexei Starovoitov <alexei.starovoitov@gmail.com>
To: Vince Weaver <vincent.weaver@maine.edu>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>,
        linux-kernel@vger.kernel.org,
        Ananth N Mavinakayanahalli <ananth@in.ibm.com>,
        Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>,
        "David S. Miller" <davem@davemloft.net>,
        Peter Zijlstra <a.p.zijlstra@chello.nl>,
        Ingo Molnar <mingo@redhat.com>,
        Arnaldo Carvalho de Melo <acme@kernel.org>,
        Steven Rostedt <rostedt@goodmis.org>
Subject: Re: perf, kprobes: fuzzer generates huge number of WARNings
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On Tue, Jul 07, 2015 at 12:00:12AM -0400, Vince Weaver wrote:
> 
> Well the BPF hack is in the fuzzer, not the kernel.  And it's not really a 
> hack, it just turned out to be a huge pain to figure out how to 
> manually create a valid BPF program in conjunction with a valid kprobe 
> event.

You mean automatically generating valid bpf program? That's definitely hard.
If you mean just few hardcoded programs then take them from samples or
from test_bpf ?

> I did have to sprinkle printks in the kprobe and bpf code to find out 
> where various EINVAL returns were coming from, so potentially this is just 
> a problem of printks happening where they shouldn't.  I'll remove those 
> changes and try to reproduce this tomorrow.

could you please elaborate on this further. Which EINVALs you talking about?

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