Re: [RFC][PATCH 00/12] various perf fixes

[Dmitry Vyukov]

On Thu, Jan 14, 2016 at 10:35 AM, Peter Zijlstra <peterz@xxxxxxxxxxxxx> wrote:
> On Tue, Jan 12, 2016 at 12:26:27PM +0100, Dmitry Vyukov wrote:
>> What do you think if we work on making syzkaller work for you locally?
>
> There's no easy way to do this right? I had a look at that project on
> github and it looks like the most complex test setup possible :-(
>
> I don't generally do VMs so I'm not much good at setting those up nor do
> I speak Go (although I did play the game a lot of years ago).
>
> Isn't there an easy way to just run syz-fuzzer on a machine without all
> the bells and whistles on?


There is a way to run it without coverage on a local machine.

First, you need to setup Go toolchain: download latest Go distribution
from https://golang.org/dl:
https://storage.googleapis.com/golang/go1.5.3.linux-amd64.tar.gz
Unpack it to $HOME/go1.5.

$ export GOROOT=$HOME/go1.5
$ export GOPATH=$HOME/gopath

Download syzkaller sources:

$ go get github.com/google/syzkaller

Build necessary syzkaller binaries:

$ cd $GOPATH/src/github.com/google/syzkaller
$ make

Then save the following content into
$GOPATH/src/github.com/google/syzkaller/perf.cfg

{
        "http": "localhost:50000",
        "workdir": "home/gopath/src/github.com/google/syzkaller/workdir",
        "syzkaller": "/home/gopath/src/github.com/google/syzkaller",
        "vmlinux": "-",
        "type": "local",
        "count": 1,
        "procs": 16,
        "nocover": true,
        "nodropprivs": true,
        "enable_syscalls": [
                "getpid",
                "perf_event_open",
                "ioctl$PERF*",
                "prctl$void",
                "bpf$*",
                "sched_yield"
        ]
}

Alter paths as necessary. Also you can change procs parameter (number
of parallel test processes), something like NCPU*4 would be a good
number. Also you can add additional syscalls to the mix.

Then run:

$ bin/syz-manager -config perf.cfg

If you run it on a separate test machine, then scp syzkaller/bin dir
and perf.cfg to the machine (the syzkaller param in config is where it
will search for the bin dir).

If syz-manager does not appear to be doing anything useful, then pleas
run it in the following mode and post output:

$ bin/syz-manager -config perf.cfg -v 1 -debug