[PATCH 04/16] irqchip/crossbar: fix allocation and init cleanup

[Haofeng Li]

From: Haofeng Li <lihaofeng@xxxxxxxxxx>

crossbar_domain_alloc() returns in the middle of a multi-IRQ
allocation without freeing IRQs and crossbar slots allocated by
earlier iterations.

If irq_domain_create_hierarchy() fails after crossbar_of_init(), the
global crossbar object and its maps and MMIO mapping are also leaked.

Roll back prior IRQs through crossbar_domain_free(), and release all
crossbar resources when domain creation fails.

Fixes: 783d31863fb8 ("irqchip: crossbar: Convert dra7 crossbar to stacked domains")

Signed-off-by: Haofeng Li <lihaofeng@xxxxxxxxxx>
---
 drivers/irqchip/irq-crossbar.c | 23 +++++++++++++++++++++--
 1 file changed, 21 insertions(+), 2 deletions(-)

diff --git a/drivers/irqchip/irq-crossbar.c b/drivers/irqchip/irq-crossbar.c
index 033b08782119..0ac5268aa8e4 100644
--- a/drivers/irqchip/irq-crossbar.c
+++ b/drivers/irqchip/irq-crossbar.c
@@ -42,6 +42,9 @@ struct crossbar_device {
 
 static struct crossbar_device *cb;
 
+static void crossbar_domain_free(struct irq_domain *domain, unsigned int virq,
+				 unsigned int nr_irqs);
+
 static void crossbar_writel(int irq_no, int cb_no)
 {
 	writel(cb_no, cb->crossbar_base + cb->register_offsets[irq_no]);
@@ -127,11 +130,14 @@ static int crossbar_domain_alloc(struct irq_domain *d, unsigned int virq,
 	for (i = 0; i < nr_irqs; i++) {
 		int err = allocate_gic_irq(d, virq + i, hwirq + i);
 
-		if (err)
+		if (err) {
+			if (i)
+				crossbar_domain_free(d, virq, i);
 			return err;
+		}
 
 		irq_domain_set_hwirq_and_chip(d, virq + i, hwirq + i,
-					      &crossbar_chip, NULL);
+					     &crossbar_chip, NULL);
 	}
 
 	return 0;
@@ -336,6 +342,18 @@ static int __init crossbar_of_init(struct device_node *node)
 	return ret;
 }
 
+static void __init crossbar_free(void)
+{
+	if (!cb)
+		return;
+
+	kfree(cb->register_offsets);
+	kfree(cb->irq_map);
+	iounmap(cb->crossbar_base);
+	kfree(cb);
+	cb = NULL;
+}
+
 static int __init irqcrossbar_init(struct device_node *node,
 				   struct device_node *parent)
 {
@@ -361,6 +379,7 @@ static int __init irqcrossbar_init(struct device_node *node,
 					     of_fwnode_handle(node), &crossbar_domain_ops, NULL);
 	if (!domain) {
 		pr_err("%pOF: failed to allocated domain\n", node);
+		crossbar_free();
 		return -ENOMEM;
 	}
 
-- 
2.25.1