[PATCH] irq: fix possible null-pointer deref irq_domain_to_irq

[Jamie Iles]

Hi Rob,

On Sun, Nov 27, 2011 at 09:11:01AM -0600, Rob Herring wrote:
> On 11/25/2011 09:35 AM, Jamie Iles wrote:
> > I wonder if this might make more sense instead.  I'll post a proper 
> > patch if you think so.
> > 
> > Regards,
> > 
> > Jamie
> > 
> > diff --git a/kernel/irq/irqdomain.c b/kernel/irq/irqdomain.c
> > index 200ce83..92c3484 100644
> > --- a/kernel/irq/irqdomain.c
> > +++ b/kernel/irq/irqdomain.c
> > @@ -143,11 +143,6 @@ int irq_domain_simple_dt_translate(struct irq_domain *d,
> >  	return 0;
> >  }
> >  
> > -struct irq_domain_ops irq_domain_simple_ops = {
> > -	.dt_translate = irq_domain_simple_dt_translate,
> > -};
> > -EXPORT_SYMBOL_GPL(irq_domain_simple_ops);
> > -
> >  /**
> >   * irq_domain_create_simple() - Set up a 'simple' translation range
> >   */
> > @@ -181,4 +176,11 @@ void irq_domain_generate_simple(const struct of_device_id *match,
> >  		pr_info("no node found\n");
> >  }
> >  EXPORT_SYMBOL_GPL(irq_domain_generate_simple);
> > +#else /* CONFIG_OF_IRQ */
> > +#define irq_domain_simple_dt_translate NULL
> >  #endif /* CONFIG_OF_IRQ */
> > +
> > +struct irq_domain_ops irq_domain_simple_ops = {
> > +	.dt_translate = irq_domain_simple_dt_translate,
> 
> .dt_translate is surrounded by CONFIG_OF, so it will break on !CONFIG_OF.

Ahh, good spot!

> > +};
> > +EXPORT_SYMBOL_GPL(irq_domain_simple_ops);
> 
> The extern declaration in irqdomain.h is surrounded by CONFIG_OF_IRQ, so
> it needs to be moved out of that as well.
> 
> On Sparc, CONFIG_OF is true, but CONFIG_OF_IRQ is false. So that
> combination needs to be handled as well.

OK, I'm travelling for a couple of days now, but I'll respin something 
when I'm back.  I guess it's a case of always exporting the simple ops 
when CONFIG_IRQDOMAIN=y, and only setting the .dt_translate when 
CONFIG_OF_IRQ=y though.

Jamie