Re: IPv6 issue in next-20171102 - lockdep and BUG handling RA packet.

From: David Ahern
Date: Mon Nov 06 2017 - 19:39:21 EST


On 11/7/17 9:31 AM, Eric Dumazet wrote:
> On Mon, Nov 6, 2017 at 4:29 PM, David Ahern <dsahern@xxxxxxxxx> wrote:
>> On 11/7/17 5:56 AM, valdis.kletnieks@xxxxxx wrote:
>>> I've hit this 6 times now, across 3 boots:
>>>
>>> Nov 3 11:04:54 turing-police kernel: [ 547.814748] BUG: sleeping function called from invalid context at mm/slab.h:422
>>>
>>> Nov 3 20:24:11 turing-police kernel: [ 60.093793] BUG: sleeping function called from invalid context at mm/slab.h:422
>>> Nov 4 20:20:54 turing-police kernel: [86264.366955] BUG: sleeping function called from invalid context at mm/slab.h:422
>>> Nov 5 19:17:40 turing-police kernel: [172469.769179] BUG: sleeping function called from invalid context at mm/slab.h:422
>>> Nov 6 06:07:37 turing-police kernel: [211467.239460] BUG: sleeping function called from invalid context at mm/slab.h:422
>>>
>>> Nov 6 14:12:43 turing-police kernel: [ 54.891848] BUG: sleeping function called from invalid context at mm/slab.h:422
>>>
>>> Something seems to be going astray while handling a RA packet.
>>
>> Odd. I tested RA before sending the patches and again just now - no
>> traceback with an RCU / lock debugging kernel. What is sending the RA's
>> in your case? I'd like to understand the config and add a test for this.
>
> Do you have CONFIG_DEBUG_ATOMIC_SLEEP=y in your .config ?
>

I needed to set sysctl -w net.ipv6.conf.eth1.use_tempaddr=1. With that I
see the trace.