Re: [PATCH] x86: check for valid irq_cfg pointer insmp_irq_move_cleanup_interrupt

From: Suresh Siddha
Date: Wed May 23 2012 - 15:26:15 EST


On Wed, 2012-05-23 at 14:04 -0500, Dimitri Sivanich wrote:
> On Wed, May 23, 2012 at 01:16:36PM -0500, Dimitri Sivanich wrote:
> > In create_irq_nr() there is a window where we have set vector_irq in
> > __assign_irq_vector(), but not yet called irq_set_chip_data() to set the
> > irq_cfg pointer.

Ha. Now I understand how it can happen during boot/module load time.
Thanks.

> BTW - is there a reason why we're calling irq_set_chip_data() in create_irq_nr()
> rather than in __assign_irq_vector() for the case where irq_cfg is NULL?

assign_irq_vector() is also for setting up vectors during irq migration.
So may be we could have done the irq_set_chip_data() in create_irq_nr()
itself before calling assign_irq_vector(). Anyways, this change can't
help in case of destroy irq path which can also lead to the same issue
of de-referencing null pointer.

Also, it will be nice if you can refer to this destroy irq path in your
changelog.

Acked-by: Suresh Siddha <suresh.b.siddha@xxxxxxxxx>

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/