Re: "ro->_ro_rt ==NULL || ro->_ro_rt->rt_refcnt > 0" failed

[Ryota Ozaki <ozaki-r%netbsd.org@localhost>]

On Wed, Sep 2, 2015 at 5:45 PM, Ryota Ozaki <ozaki-r%netbsd.org@localhost> wrote:
> Hi,
>
> Thank you for rechecking.
>
> I found you're right and I mess up. I've been using a kernel
> with a different config from GENERIC, which is tuned for
> KVM to reduce build time. So I'm now able to reproduce the
> issue again with a latest GENERIC kernel. I've started
> debugging really.

I found nd6_lookup is broken. Here is a patch to fix the issue:
http://www.netbsd.org/~ozaki-r/fix-ipv6-refcnt.diff
It works for me. I hope it works for you too.

The change looks big because it is based on my local change that
cleans up complicated nd6_lookup though, the point is to replace
rtfree with RTFREE_IF_NEEDED.

Thanks,
  ozaki-r

>
> Thank you so much!
>   ozaki-r
>
> On Wed, Sep 2, 2015 at 5:06 PM, Paul Goyette <paul%vps1.whooppee.com@localhost> wrote:
>> On Wed, 2 Sep 2015, Ryota Ozaki wrote:
>>
>>> On Wed, Sep 2, 2015 at 3:16 PM, Ryota Ozaki <ozaki-r%netbsd.org@localhost> wrote:
>>>>
>>>> Hi Paul and Jun,
>>>>
>>>> Thank you for your reporting!
>>>>
>>>> Now I can reproduce the issue quickly using openvpn.
>>>> So I would provide a fix soon (hopefully).
>>>
>>>
>>> Oops. The tested kernel was built at 8/24. A kernel built today
>>> doesn't reproduce the issue...
>>
>>
>>
>> Hmmm, I don't know what kernel you have from Aug 24.  But a kernel that was
>> built from up-to-date sources less than one hour ago (and with no subsequent
>> CVS commits!) still fails.
>>
>> This kernel identifies itself as
>>
>> %uname -a
>> NetBSD pokey.whooppee.com 7.99.21 NetBSD 7.99.21 (GENERIC) #0: Wed Sep  2
>> 15:49:03 PHT 2015
>> paul%pokey.whooppee.com@localhost:/build/netbsd-local/obj/amd64/sys/arch/amd64/compile/GENERIC
>> amd64
>>
>> And I have attached the Xterm log from my gdb session (after running
>>
>>         tr -d '\r'
>>
>> to remove trailing ^M characters!)
>>
>>
>>
>>
>>
>>
>> -------------------------------------------------------------------------
>> | Paul Goyette     | PGP Key fingerprint:     | E-mail addresses:       |
>> | (Retired)        | FA29 0E3B 35AF E8AE 6651 | paul at whooppee.com    |
>> | Kernel Developer | 0786 F758 55DE 53BA 7731 | pgoyette at netbsd.org  |
>> -------------------------------------------------------------------------