simulating wireless device (if_alloc panic, VirtualBox, VIMAGE)

[Bjoern A. Zeeb]

On Wed, 2 Feb 2011, Monthadar Al Jaberi wrote:

Hi,

> Thanx makes more sense, but I have noticed something weired if you can
> shade some light on.
>
> I added printfs one when the module is first loaded (static int
> event_handler(module_t module, int event, void *arg)):
> curthread=0xc3f95870
> curthread->td_vnet=0xc3170e00
> curthread->td_ucred=0xc3185d00
> TD_TO_VNET=0
> CRED_TO_VNET=0

Try to load it from laoder on boot; I think that should work as we are
setting the curvent for the kernel startup.

The problem you are seeing is a bug in the current implementation that
you cannot add any physical network interface after the kernel started.
This applies to cardbus/usb/... as well as any kind of ethernet
interface, so a kldload igb should yield it as well.

The fix for that is easy and hard at the same time:
A) either touch all drivers
B) or touch all cloned interfaces and change 3 common lines.
    or try to make cloners aware of vimages.

Solution B) is sitting in perforce with the entire stuff that it depends
on and was started with CH=179022,179255 but not limited to that if you
want to have a peek.

What you certainly can do locally to your driver for now is to make a
change like this:

+#ifdef VIMAGE
+       CURVNET_SET(vnet0);
+#endif
         ifp = if_alloc(IFT_ETHER);
+#ifdef VIMAGE
+       CURVNET_RESTORE();
+#endif

It's the type A) kind of change from above that will break eventually
in the future.

/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