Messages in this thread | | | Date | Thu, 16 Oct 2008 16:11:45 -0700 | From | Andrew Morton <> | Subject | Re: [PATCH] NULL struct irq_desc's member 'name' in dynamic_irq_cleanup() |
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On Thu, 16 Oct 2008 07:58:08 -0500 Dean Nelson <dcn@sgi.com> wrote:
> If the member 'name' of the irq_desc structure happens to point to a character > string that is resident within a kernel module, problems insue if that module > is rmmod'd (at which time dynamic_irq_cleanup() is called) and then later > show_interrupts() is called by someone.
It would be nice to spell out what the "problems" are.
> It is also not a good thing if the > character string resided in kmalloc'd space that has been kfree'd (after > having called dynamic_irq_cleanup()). dynamic_irq_cleanup() fails to NULL > the 'name' member and show_interrupts() references it on a few architectures > (like h8300, sh and x86). > > Signed-off-by: Dean Nelson <dcn@sgi.com> > > --- > > kernel/irq/chip.c | 1 + > 1 file changed, 1 insertion(+) > > Index: linux/kernel/irq/chip.c > =================================================================== > --- linux.orig/kernel/irq/chip.c 2008-10-15 07:44:31.000000000 -0500 > +++ linux/kernel/irq/chip.c 2008-10-16 06:55:56.000000000 -0500 > @@ -79,6 +79,7 @@ void dynamic_irq_cleanup(unsigned int ir > desc->chip_data = NULL; > desc->handle_irq = handle_bad_irq; > desc->chip = &no_irq_chip; > + desc->name = NULL; > spin_unlock_irqrestore(&desc->lock, flags); > } >
Because we should work out whether this should be backported into -stable. And if so, how far back it should go.
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