svn commit: r228969 - head/sys/netinet

[Mikolaj Golub]

On Wed, Oct 16, 2013 at 05:09:04PM -0400, John Baldwin wrote:
...
> >  >> #10 0x80b6f1fd in igmp_change_state (inm=0x8ae70480)
> >  >>     at /home/golub/freebsd/base/head/sys/netinet/igmp.c:2595
> >  >> #11 0x80b76f68 in in_leavegroup_locked (inm=0x8ae70480, imf=0x8a655a00)
> >  >>     at /home/golub/freebsd/base/head/sys/netinet/in_mcast.c:1239
> >  >> #12 0x80b76fbd in in_leavegroup (inm=0x8ae70480, imf=0x8a655a00)
> >  >>     at /home/golub/freebsd/base/head/sys/netinet/in_mcast.c:1184
> >  >> #13 0x80b770b4 in inp_gcmoptions (context=0x0, pending=1)
> >  >>     at /home/golub/freebsd/base/head/sys/netinet/in_mcast.c:1554
> >  >> #14 0x80a8ff2b in taskqueue_run_locked (queue=0x87594880)
> >  >>     at /home/golub/freebsd/base/head/sys/kern/subr_taskqueue.c:308
> >  >> #15 0x80a90987 in taskqueue_thread_loop (arg=0x81186bcc)
> >  >>     at /home/golub/freebsd/base/head/sys/kern/subr_taskqueue.c:497
> >  >> #16 0x80a1b2d8 in fork_exit (callout=0x80a90920
> >  >> <taskqueue_thread_loop>, arg=0x81186bcc,
> >  >>     frame=0x872b2d28) at /home/golub/freebsd/base/head/sys/kern/kern_fork.c:992
...
> >  >> VNET context is not set at that point.
...
> 
> I think this was just fixed by glebius@ in r256587:
> 
> Author: glebius
> Date: Wed Oct 16 05:02:01 2013
> New Revision: 256587
> URL: http://svnweb.freebsd.org/changeset/base/256587
> 
> Log:
>   For VIMAGE kernels store vnet in the struct task, and set vnet context
>   during task processing.
>   
>   Reported & tested by: mm

I think that particular issue was fixed earlier by hrs in r252510:

  Fix a panic when leaving MC group in a kernel with VIMAGE enabled.
  in_leavegroup() is called from an asynchronous task, and
  igmp_change_state() requires that curvnet is set by the caller.

Concerning this more general solution from Gleb, with storing the vnet
pointer in the task, I wander how it is safe when the vnet is being
removed?

In vnet_destroy() the vnet interfaces are moved back to their parent
vnets, so setting the vnet context from the interface looks safer.

-- 
Mikolaj Golub