Re: [PATCH 11/14] xen: events: dynamically allocate irq infostructures

From: Ian Campbell
Date: Thu Mar 10 2011 - 03:51:37 EST


On Thu, 2011-03-10 at 05:27 +0000, Konrad Rzeszutek Wilk wrote:
> > @@ -649,10 +653,9 @@ int xen_bind_pirq_gsi_to_irq(unsigned gsi,
> >
> > spin_lock(&irq_mapping_update_lock);
> >
> > - if ((pirq > nr_irqs) || (gsi > nr_irqs)) {
> > - printk(KERN_WARNING "xen_map_pirq_gsi: %s %s is incorrect!\n",
> > - pirq > nr_irqs ? "pirq" :"",
> > - gsi > nr_irqs ? "gsi" : "");
> > + if (pirq > nr_irqs) {
> > + printk(KERN_WARNING "xen_map_pirq_gsi: pirq %d > nr_irqs %d!\n",
> > + pirq, nr_irqs);
>
> Looks like this belongs to another patch?

To be honest I'm not entirely sure what that check was protecting
anyway. Possibly it comes from a time when the GSI<->IRQ was 1-1 and
prevented us from spilling off the end of the irq_info array.

It may be that it is safe to have gsi > nr_irqs in an earlier patch in
this series (possibly "xen: events: maintain a list of Xen interrupts")
or even in one of my earlier series which switched to using the core
interrupt allocation logic and/or removed the 1-1 mapping above
nr_irqs_gsi in certain cases.

Anyway, this is the first patch where I'm pretty sure it is safe to
allow GSI > nr_irqs since there are no nr_irqs based limitations left
apart from the pirq one.

Ian.

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