On Di, 2018-02-27 at 17:07 +0000, Roger Pau Monné wrote:
> On Tue, Feb 27, 2018 at 03:55:58PM +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 Monné <roger.pau@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>
> > ---
> > drivers/xen/events/events_base.c | 5 ++++-
> > 1 file changed, 4 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/xen/events/events_base.c
> > b/drivers/xen/events/events_base.c
> > index c86d10e..a299586 100644
> > --- a/drivers/xen/events/events_base.c
> > +++ b/drivers/xen/events/events_base.c
> > @@ -750,11 +750,14 @@ int xen_bind_pirq_msi_to_irq(struct pci_dev
> > *dev, struct msi_desc *msidesc,
> >
> > ret = irq_set_msi_desc(irq, msidesc);
> > if (ret < 0)
> > - goto error_irq;
> > + goto error_desc;
> > out:
> > mutex_unlock(&irq_mapping_update_lock);
> > return irq;
> > error_irq:
> > + while (--nvec >= i)
> > + xen_free_irq(irq + nvec);
> > +error_desc:
> > while (i > 0) {
> > i--;
> > __unbind_from_irq(irq + i);
> It seems pointless to introduce another label and another loop to fix
> something that can be fixed with a single label and a single loop,
> this just makes the code more complex for no reason.
I disagree, just because there are two different cleanups to be made
for two different issues; it's not as if the if.. and else conditions
are going to be interleaved.
Anyway it's a matter of taste.
Since you've already proposed the patch, would you mind baking a proper
one and posting it?
Thanks!
> IMHO the way to solve this issue is:
>
> while (nvec--) {
> if (nvec >= i)
> xen_free_irq(irq + nvec);
> else
> __unbind_from_irq(irq + nvec);
> }
Amit
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