simulating wireless device (if_alloc panic, VirtualBox, VIMAGE)

[Bjoern A. Zeeb]

On Thu, 3 Feb 2011, Monthadar Al Jaberi wrote:

> On Thu, Feb 3, 2011 at 12:18 PM, Bjoern A. Zeeb
> <bzeeb-lists at lists.zabbadoz.net> wrote:
>> On Thu, 3 Feb 2011, Monthadar Al Jaberi wrote:
>>
>>> On Thu, Feb 3, 2011 at 11:59 AM, Bjoern A. Zeeb
>>> <bzeeb-lists at lists.zabbadoz.net> wrote:
>>>>
>>>> On Thu, 3 Feb 2011, Monthadar Al Jaberi wrote:
>>>>
>>>>>>>> I don't understand why you saw a CRED_TO_VNET of 0
>>>>>>>> I was under the impression that every process/thread in the system
>>>>>>>> would
>>>>>>>> be
>>>>>>>> on vnet0
>>>>>>>> in a vimage kernel.
>>>>>>>
>>>>>>> This is how my printf looks like:
>>>>>>> struct thread *td = curthread;
>>>>>>> struct vnet *v = TD_TO_VNET(td);
>>>>>>> struct ucred *cred = CRED_TO_VNET(td->ucred);
>>>>>>> struct vnet *td_vnet = td->td_vnet;
>>>>>>
>>>>>> here's your problem:
>>>>>>
>>>>>> strcut vnet *vnet = cred->cr_prison->pr_vnet;
>>>>>
>>>>> When I add CURVNET_SET(CRED_TO_VNET(curthread->td_ucred)); I get a panic
>>>>> too...
>>>>> But your suggestion works if I do like this:
>>>>> curthread->td_vnet = curthread->td_ucred->cr_prison->pr_vnet;
>>>>>
>>>>> CRED_TO_VNET(curthread->td_ucred) returns NULL
>>>>
>>>> I wonder how you are building your module and if VIMAGE is properly
>>>> defined.  If it's not that would explain a lot of things.
>>>
>>> I have put options VIMAGE, rebuild both world and kernel.
>>>
>>> I can create jails with vnet options...
>>>
>>> I build my module with the standard Makefile for modules:
>>> ...
>>> KMOD    =  wtap
>>> ...
>>> SRCS    =  if_wtap_module.c if_wtap.c if_medium.c hal.c
>>>
>>> .include <bsd.kmod.mk>
>>
>> Right but are you building your module along with the kernel or
>> outside the tree?  In the latter case you may want to add soemthing
>> like
>>
>> SRCS+=          opt_global.h
>>
>> .if defined(KERNBUILDDIR)
>> MKDEP=          -include ${KERNBUILDDIR}/opt_global.h
>> .else
>> CFLAGS+=        -include opt_global.h
>> MKDEP=          -include opt_global.h
>>
>> opt_global.h:
>>        echo "#define VIMAGE 1" > ${.TARGET}
>> .endif
>>
>> and/or point KERNBUILDDIR to where you built your kernels.
>
> Thanks it works now..


One thing you should be aware of is that if you will compile without
KERNBUILDDIR set, your module will not work on a non-VIMAGE kernel.

Unfortuantely we can only have defaults for one or the other in the
case.  Worst you may want to only do the "echo" if there was a command
line option like -DVIMAGE or the like.  Note, setting it to 0 will not
do the trick as it would still be defined.

/bz

-- 
Bjoern A. Zeeb                                 You have to have visions!
         <ks> Going to jail sucks -- <bz> All my daemons like it!
   http://www.freebsd.org/doc/en_US.ISO8859-1/books/handbook/jails.html