Commit 4615fbc3 authored Nov 29, 2020 by Marc Zyngier Committed by Thomas Gleixner Nov 30, 2020

genirq/irqdomain: Don't try to free an interrupt that has no mapping



When an interrupt allocation fails for N interrupts, it is pretty
common for the error handling code to free the same number of interrupts,
no matter how many interrupts have actually been allocated.

This may result in the domain freeing code to be unexpectedly called
for interrupts that have no mapping in that domain. Things end pretty
badly.

Instead, add some checks to irq_domain_free_irqs_hierarchy() to make sure
that thiss does not follow the hierarchy if no mapping exists for a given
interrupt.

Fixes: 6a6544e5 ("genirq/irqdomain: Remove auto-recursive hierarchy support")
Signed-off-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20201129135551.396777-1-maz@kernel.org

parent 15b8d937

kernel/irq/irqdomain.c

+9 −2

Original line number	Diff line number	Diff line
		@@ -1381,8 +1381,15 @@ static void irq_domain_free_irqs_hierarchy(struct irq_domain *domain,
		unsigned int irq_base,
		unsigned int nr_irqs)
		{
		if (domain->ops->free)
		domain->ops->free(domain, irq_base, nr_irqs);
		unsigned int i;

		if (!domain->ops->free)
		return;

		for (i = 0; i < nr_irqs; i++) {
		if (irq_domain_get_irq_data(domain, irq_base + i))
		domain->ops->free(domain, irq_base + i, 1);
		}
		}

		int irq_domain_alloc_irqs_hierarchy(struct irq_domain *domain,

Admin message