Re: [PATCH 1/9] irq-remove: core

[Jeff Garzik <jeff@garzik.org>]

Eric W. Biederman wrote:
> Jeff Garzik <jeff@garzik.org> writes:
>
> > commit 008b5fcf3c1d8456005de26ddd4256b1369225e8
> > Author: Jeff Garzik <jeff@garzik.org>
> > Date:   Fri Oct 19 00:45:51 2007 -0400
> >
> >     [IRQ ARG REMOVAL] core interrupt delivery infrastructure updates
> >
> >  include/asm-generic/irq_regs.h |   25 +++++++++++++++++++++++++
> >  include/linux/interrupt.h      |    4 ++--
> >  kernel/irq/handle.c            |    5 +++--
> >  kernel/irq/manage.c            |    4 ++--
> >  kernel/irq/spurious.c          |    3 ++-
> >  lib/irq_regs.c                 |    5 +++++
> >  6 files changed, 39 insertions(+), 7 deletions(-)
> >
> > 008b5fcf3c1d8456005de26ddd4256b1369225e8
> > diff --git a/include/asm-generic/irq_regs.h b/include/asm-generic/irq_regs.h
> > index 5ae1d07..1d99ef4 100644
> > --- a/include/asm-generic/irq_regs.h
> > +++ b/include/asm-generic/irq_regs.h
> > @@ -34,4 +34,29 @@ static inline struct pt_regs *set_irq_regs(struct pt_regs
> > *new_regs)
> >  	return old_regs;
> >  }
> >  
> > +DECLARE_PER_CPU(unsigned int, __irqfunc_irqs);
> > +
> > +static inline unsigned int get_irqfunc_irq(void)
> > +{
> > +	return __get_cpu_var(__irqfunc_irqs);
> > +}
> > +
> > +#if 0
> > +static inline unsigned int set_irqfunc_irq(unsigned int new_irq)
> > +{
> > +	unsigned int old_irq, *pirq = &__get_cpu_var(__irqfunc_irqs);
> > +
> > +	old_irq = *pirq;
> > +	*pirq = new_irq;
> > +	return old_irq;
> > +}
> > +#else
> > +static inline void set_irqfunc_irq(unsigned int new_irq)
> > +{
> > +	int *pirq = &__get_cpu_var(__irqfunc_irqs);
> > +
> > +	*pirq = new_irq;
> > +}
> > +#endif
>
> Please look at handle_IRQ_event.  Local irqs are enabled so irq
> recursion can happen.  So not handling old_irq is a big nasty
> bug.

Do you think set_irqfunc_irq() should be called at all the callsites of 
set_irq_regs(), or one the fix you mention is applied, do you think 
current model is sufficient?

	Jeff



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