Re: [Linux-ATM-General] Fwd: Re: [PATCH] pppoatm carrier status

[Philip P. <phi...@re...>]

  On 9/22/10 8:21 AM, Karl Hiramoto wrote:
> On 09/22/10 16:21, chas williams - CONTRACTOR wrote:
>> On Tue, 21 Sep 2010 21:19:45 -0700
>> Philip Prindeville<phi...@re...>  wrote:
>>
>>
>>> BUG: unable to handle kernel NULL pointer dereference at 00000090
>> like it said, null pointer dereference.  i.e. (null)->something
>>
>>> IP: [<e0133050>] :ppp_generic:ppp_channel_carrier_on+0x16/0x31
>> very early in ppp_channel_carrier_on() which means it is likely
>> 'struct channel *pch = chan->ppp;' where chan is null for some reason.
>> there could be an ordering issue here.  pvcc->chan might not be
>> assigned by the time the event is ready to fire.  it is reasonable to
>> expect that the carrier status of the hardware device will change
>> before the vcc is even assigned to the ppp layer.
>>
>>
> Yeah, thats exactly what it is. The last version of the patch i sent
> checks "if (pch->ppp)"
>
> in pppoatm when ppp_register_channel() is called the PPP channel is not
> yet connected so pch->ppp is null.

Ok, that didn't crash.

Now how is the state exposed into user-space?