On 2020-08-19 14:31, Mark-PK Tsai wrote:

From: Marc Zyngier <maz@kernel.org>

quoted

quoted

+
+static int mst_intc_domain_alloc(struct irq_domain *domain, unsigned
int virq,
+				 unsigned int nr_irqs, void *data)
+{
+	int i;
+	irq_hw_number_t hwirq;
+	struct irq_fwspec parent_fwspec, *fwspec = data;
+	struct mst_intc_chip_data *cd = (struct mst_intc_chip_data
*)domain->host_data;

No cast necessary here.

quoted

+
+	/* Not GIC compliant */
+	if (fwspec->param_count != 3)
+		return -EINVAL;
+
+	/* No PPI should point to this domain */
+	if (fwspec->param[0])
+		return -EINVAL;
+
+	if (fwspec->param[1] >= cd->nr_irqs)

This condition is bogus, as it doesn't take into account the nr_irqs
parameter.

The hwirq number need to be in the irq map range. (property:
mstar,irqs-map-range)
If it's not, it must be incorrect configuration.

I agree. And since you are checking whether the configuration is 
correct,
it'd better be completely correct.

So how about use the condition as following?

if (hwirq >= cd->nr_irqs)
	return -EINVAL;

Again, this says nothing of the validity of (hwirq + nr_irqs - 1)...

quoted

quoted

+		return -EINVAL;
+
+	hwirq = fwspec->param[1];
+	for (i = 0; i < nr_irqs; i++)
+		irq_domain_set_hwirq_and_chip(domain, virq + i, hwirq + i,
+					      &mst_intc_chip,
+					      domain->host_data);

... which you are using here.

         M.
-- 
Jazz is not dead. It just smells funny...

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