Re: [PATCH 2/2] xen: events: free irqs in error condition

From: Shah, Amit
Date: Mon Feb 26 2018 - 13:57:17 EST



On Mo, 2018-02-26 at 18:14 +0000, Roger Pau Monnà wrote:
> On Mon, Feb 26, 2018 at 05:36:35PM +0000, Amit Shah wrote:
> >
> > In case of errors in irq setup for MSI, free up the allocated irqs.
> >
> > Fixes: 4892c9b4ada9f9 ("xen: add support for MSI message groups")
> > Reported-by: Hooman Mirhadi <mirhadih@xxxxxxxxxx>
> > CC: <stable@xxxxxxxxxxxxxxx>
> > CC: Roger Pau Monnà <roger.pau@xxxxxxxxxx>
> > CC: David Vrabel <david.vrabel@xxxxxxxxxx>
> > CC: Boris Ostrovsky <boris.ostrovsky@xxxxxxxxxx>
> > CC: Eduardo Valentin <eduval@xxxxxxxxxx>
> > CC: Juergen Gross <jgross@xxxxxxxx>
> > CC: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
> > CC: "K. Y. Srinivasan" <kys@xxxxxxxxxxxxx>
> > CC: Liu Shuo <shuo.a.liu@xxxxxxxxx>
> > CC: Anoob Soman <anoob.soman@xxxxxxxxxx>
> > Signed-off-by: Amit Shah <aams@xxxxxxxxxx>
> > ---
> > Âdrivers/xen/events/events_base.c | 1 +
> > Â1 file changed, 1 insertion(+)
> >
> > diff --git a/drivers/xen/events/events_base.c
> > b/drivers/xen/events/events_base.c
> > index b6b8b29..96aa575 100644
> > --- a/drivers/xen/events/events_base.c
> > +++ b/drivers/xen/events/events_base.c
> > @@ -758,6 +758,7 @@ int xen_bind_pirq_msi_to_irq(struct pci_dev
> > *dev, struct msi_desc *msidesc,
> > Âerror_irq:
> > Â for (; i >= 0; i--)
> > Â __unbind_from_irq(irq + i);
> > + xen_free_irq(irq);
> Hm, xen_free_irq calls irq_free_desc, which is irq_free_descs(irq,
> 1),

Er... Âright.

> I think you will have to introduce a new free function:
>
> xen_free_irqs(unsigned irq, unsigned int nr)
>
> That calls irq_free_descs(irq, nr)

Actually, xen_free_irq() is already done in __unbind_from_irq(), so
this patch is actually wrong and not needed.


Amit
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