Re: [PATCH 1/2] xen: close evtchn port if binding to irq fails

[Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>]

On Tue, Feb 19, 2013 at 02:46:31PM +0000, Wei Liu wrote:
> On Tue, 2013-02-19 at 14:32 +0000, Konrad Rzeszutek Wilk wrote:
> > On Mon, Feb 18, 2013 at 02:57:58PM +0000, Wei Liu wrote:
> > > Signed-off-by: Wei Liu <wei.liu2@citrix.com>
> > 
> > I thought we had discussed doing this check in the user of
> > this as well?
> > 
> 
> Hah? I remember Jan's comment on the port == 0 case and your suggestion
> to add BUG_ON() in the unbind path. Did I miss anything?

This patch by itself is fine. I thought that we had chatted of adding
a check in evtchn_bind_to_user to check the return value and so
something about it. But the more I think about this - it makes less
sense than doing it here.

So this patch is good - putting it on my 3.9 list.
> 
> 
> Wei.
> 
> > > ---
> > >  drivers/xen/evtchn.c |   10 ++++++++++
> > >  1 file changed, 10 insertions(+)
> > > 
> > > diff --git a/drivers/xen/evtchn.c b/drivers/xen/evtchn.c
> > > index b1f60a0..b2db77e 100644
> > > --- a/drivers/xen/evtchn.c
> > > +++ b/drivers/xen/evtchn.c
> > > @@ -269,6 +269,14 @@ static int evtchn_bind_to_user(struct per_user_data *u, int port)
> > >  				       u->name, (void *)(unsigned long)port);
> > >  	if (rc >= 0)
> > >  		rc = evtchn_make_refcounted(port);
> > > +	else {
> > > +		/* bind failed, should close the port now */
> > > +		struct evtchn_close close;
> > > +		close.port = port;
> > > +		if (HYPERVISOR_event_channel_op(EVTCHNOP_close, &close) != 0)
> > > +			BUG();
> > > +		set_port_user(port, NULL);
> > > +	}
> > >  
> > >  	return rc;
> > >  }
> > > @@ -277,6 +285,8 @@ static void evtchn_unbind_from_user(struct per_user_data *u, int port)
> > >  {
> > >  	int irq = irq_from_evtchn(port);
> > >  
> > > +	BUG_ON(irq < 0);
> > > +
> > >  	unbind_from_irqhandler(irq, (void *)(unsigned long)port);
> > >  
> > >  	set_port_user(port, NULL);
> > > -- 
> > > 1.7.10.4
> > > 
> 
>