irqchip/alpine-msi: Fix freeing of interrupts on allocation error path

The alpine-msi driver has an interesting allocation error handling,
where it frees the same interrupts repeatedly. Hilarity follows.

This code is probably never executed, but let's fix it nonetheless.

Fixes: e6b78f2c3e14 ("irqchip: Add the Alpine MSIX interrupt controller")
Signed-off-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Antoine Tenart <atenart@kernel.org>
Cc: Tsahee Zidenberg <tsahee@annapurnalabs.com>
Cc: Antoine Tenart <atenart@kernel.org>
Link: https://lore.kernel.org/r/20201129135525.396671-1-maz@kernel.org

diff --git a/drivers/irqchip/irq-alpine-msi.c b/drivers/irqchip/irq-alpine-msi.c
index 23a3b87..ede02dc 100644 (file)
--- a/drivers/irqchip/irq-alpine-msi.c
+++ b/drivers/irqchip/irq-alpine-msi.c
@@ -165,8 +165,7 @@ static int alpine_msix_middle_domain_alloc(struct irq_domain *domain,
        return 0;
 
 err_sgi:
-       while (--i >= 0)
-               irq_domain_free_irqs_parent(domain, virq, i);
+       irq_domain_free_irqs_parent(domain, virq, i - 1);
        alpine_msix_free_sgi(priv, sgi, nr_irqs);
        return err;
 }