Re: lockdep WARNING in get_online_cpus

From: Dmitry Vyukov
Date: Tue Apr 05 2016 - 05:44:38 EST


On Tue, Apr 5, 2016 at 11:41 AM, Peter Zijlstra <peterz@xxxxxxxxxxxxx> wrote:
> On Mon, Apr 04, 2016 at 11:50:07AM +0200, Dmitry Vyukov wrote:
>> Yes, I am able to reproduce it by running:
>>
>> # ./syz-execprog -cover=0 -repeat=0 -procs=20 -nobody=0
>> crash-qemu-26-1459761514194788294
>>
>> crash-qemu-26-1459761514194788294 being:
>> https://gist.githubusercontent.com/dvyukov/bce719c2b7dede54f96d8bbb7c78714f/raw/08a7a237986f0e3bccc7c0e800a3bdaa32e1fc0b/gistfile1.txt
>
>
> root@ivb-ep:~/gopath/src/github.com/google/syzkaller# ./bin/syz-execprog -cover=0 -repeat=0 -procs=20 -nobody=0 gistfile1.txt
> 2016/04/05 11:39:37 parsed 391 programs
> 2016/04/05 11:39:37 executed 0 programs
> result: failed=false hanged=false err=failed to start executor binary: fork/exec /root/gopath/src/github.com/google/syzkaller: permission denied
>
> result: failed=false hanged=false err=failed to start executor binary: fork/exec /root/gopath/src/github.com/google/syzkaller: permission denied
>
> result: failed=false hanged=false err=failed to start executor binary: fork/exec /root/gopath/src/github.com/google/syzkaller: permission denied
>
> (which goes on ad inf.)
>
> Clearly I'm not doing it right.. help?

The latest version of syz-execproc uses ./syz-executor by default. If
you don't have ./syz-executor, add -executor=/path/to/syz-executor.