Re: [PATCH v2 2/2] virtio: console: add locking around c_ovq operations

[Amit Shah <amit.shah@redhat.com>]

On (Sat) 30 Mar 2013 [14:28:28], Rusty Russell wrote:
> Amit Shah <amit.shah@redhat.com> writes:
> > When multiple ovq operations are being performed (lots of open/close
> > operations on virtio_console fds), the __send_control_msg() function can
> > get confused without locking.
> >
> > A simple recipe to cause badness is:
> > * create a QEMU VM with two virtio-serial ports
> > * in the guest, do
> >   while true;do echo abc >/dev/vport0p1;done
> >   while true;do echo edf >/dev/vport0p2;done
> >
> > In one run, this caused a panic in __send_control_msg().  In another, I
> > got
> >
> >    virtio_console virtio0: control-o:id 0 is not a head!
> 
> Both applied to my fixes branch, with CC: stable added.
> 
> For future reference, I prefer you to put the CC: stable@kernel.org tag
> in if you think it's a stable candidate.

Will do,

Thanks

		Amit