svn commit: r253346 - in head/sys: kern net netgraph netgraph/bluetooth/socket

[Marko Zec]

On Thursday 25 July 2013 10:07:58 Marius Strobl wrote:
> On Mon, Jul 15, 2013 at 01:32:55AM +0000, Craig Rodrigues wrote:
> > Author: rodrigc
> > Date: Mon Jul 15 01:32:55 2013
> > New Revision: 253346
> > URL: http://svnweb.freebsd.org/changeset/base/253346
> >
> > Log:
> >   PR: 168520 170096
> >   Submitted by: adrian, zec
> >
> >   Fix multiple kernel panics when VIMAGE is enabled in the kernel.
> >   These fixes are based on patches submitted by Adrian Chadd and Marko
> > Zec.
> >
> >   (1)  Set curthread->td_vnet to vnet0 in device_probe_and_attach()
> > just before calling device_attach().  This fixes multiple VIMAGE
> > related kernel panics when trying to attach Bluetooth or USB Ethernet
> > devices because curthread->td_vnet is NULL.
> >
> >   (2)  Set curthread->td_vnet in if_detach().  This fixes kernel panics
> > when detaching networking interfaces, especially USB Ethernet devices.
> >
> >   (3)  Use VNET_DOMAIN_SET() in ng_btsocket.c
> >
> >   (4)  In ng_unref_node() set curthread->td_vnet.  This fixes kernel
> > panics when detaching Netgraph nodes.
> >
> > Modified:
> >   head/sys/kern/subr_bus.c
> >   head/sys/net/if.c
> >   head/sys/netgraph/bluetooth/socket/ng_btsocket.c
> >   head/sys/netgraph/ng_base.c
> >
> > Modified: head/sys/kern/subr_bus.c
> > =======================================================================
> >======= --- head/sys/kern/subr_bus.c	Mon Jul 15 00:49:10 2013	(r253345)
> > +++ head/sys/kern/subr_bus.c	Mon Jul 15 01:32:55 2013	(r253346) @@
> > -53,6 +53,8 @@ __FBSDID("$FreeBSD$");
> >  #include <sys/bus.h>
> >  #include <sys/interrupt.h>
> >
> > +#include <net/vnet.h>
> > +
> >  #include <machine/stdarg.h>
> >
> >  #include <vm/uma.h>
> > @@ -2735,7 +2737,11 @@ device_probe_and_attach(device_t dev)
> >  		return (0);
> >  	else if (error != 0)
> >  		return (error);
> > -	return (device_attach(dev));
> > +
> > +	CURVNET_SET_QUIET(vnet0);
> > +	error = device_attach(dev);
> > +	CURVNET_RESTORE();
> > +	return error;
> >  }
>
> Uhm - do we really need to have that layering violation in subr_bus.c?
> Wouldn't it be sufficient to set curthread->td_vnet to vnet0 in
> if_alloc(9) or if_attach(9) at least instead?

That wouldn't solve the issues with attaching netgraph node(s) to the 
arriving device, nor potentially other issues unrelated to if_alloc or 
if_attach.

Marko