Re: [Xen-devel] [PATCH 4/4] xen/events: Add WARN_ON when quick lookup found invalid type.

[Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>]

On Thu, May 24, 2012 at 11:58:11AM +0100, Stefano Stabellini wrote:
> On Wed, 23 May 2012, Konrad Rzeszutek Wilk wrote:
> > All of the bind_XYZ_to_irq do a quick lookup to see if the
> > event exists. And if they that value is returned instead of
> 
>                            ^

Lack of filters for coffee caused that :-)

> 
> > initialized. This patch adds an extra logic to check that the
> > type returned is the proper one and we can use it to find
> > drivers that are doing something naught.
> > 
> > Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>
> > ---
> >  drivers/xen/events.c |   11 +++++++++--
> >  1 files changed, 9 insertions(+), 2 deletions(-)
> > 
> > diff --git a/drivers/xen/events.c b/drivers/xen/events.c
> > index faae2f9..093851b 100644
> > --- a/drivers/xen/events.c
> > +++ b/drivers/xen/events.c
> > @@ -827,6 +827,9 @@ int bind_evtchn_to_irq(unsigned int evtchn)
> >                                           handle_edge_irq, "event");
> >  
> >             xen_irq_info_evtchn_init(irq, evtchn);
> > +   } else {
> > +           struct irq_info *info = info_for_irq(irq);
> > +           WARN_ON(info && info->type != IRQT_EVTCHN);
> >     }
> 
> considering that when evtchn_to_irq[evtchn] is != -1, a corresponding
> struct irq_info is always supposed to exists, shouldn't this be:
> 
> WARN_ON(info == NULL || info->type != IRQT_EVTCHN);

<nods> Much better. Will do that.

> 
> ?
> 
> 
> >  out:
> > @@ -862,8 +865,10 @@ static int bind_ipi_to_irq(unsigned int ipi, unsigned 
> > int cpu)
> >             xen_irq_info_ipi_init(cpu, irq, evtchn, ipi);
> >  
> >             bind_evtchn_to_cpu(evtchn, cpu);
> > +   } else {
> > +           struct irq_info *info = info_for_irq(irq);
> > +           WARN_ON(info && info->type != IRQT_IPI);
> >     }
> > -
> >   out:
> >     mutex_unlock(&irq_mapping_update_lock);
> >     return irq;
> > @@ -939,8 +944,10 @@ int bind_virq_to_irq(unsigned int virq, unsigned int 
> > cpu)
> >             xen_irq_info_virq_init(cpu, irq, evtchn, virq);
> >  
> >             bind_evtchn_to_cpu(evtchn, cpu);
> > +   } else {
> > +           struct irq_info *info = info_for_irq(irq);
> > +           WARN_ON(info && info->type != IRQT_VIRQ);
> >     }
> > -
> >  out:
> >     mutex_unlock(&irq_mapping_update_lock);
> 
> same here
> --
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