irqchip/sunxi-nmi: Fix error check of of_io_request_and_map()

The of_io_request_and_map() returns a valid pointer in iomem region or
ERR_PTR(), check for NULL always fails and may cause a NULL pointer
dereference on error path.

Fixes: 0e841b04c829 ("irqchip/sunxi-nmi: Switch to of_io_request_and_map() from of_iomap()")
Signed-off-by: Vladimir Zapolskiy <vz@mleia.com>
Cc: Jason Cooper <jason@lakedaemon.net>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Chen-Yu Tsai <wens@csie.org>
Cc: Maxime Ripard <maxime.ripard@free-electrons.com>
Cc: linux-arm-kernel@lists.infradead.org
Link: http://lkml.kernel.org/r/1457486489-10189-1-git-send-email-vz@mleia.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

diff --git a/drivers/irqchip/irq-sunxi-nmi.c b/drivers/irqchip/irq-sunxi-nmi.c
index 0820f67..668730c 100644 (file)
--- a/drivers/irqchip/irq-sunxi-nmi.c
+++ b/drivers/irqchip/irq-sunxi-nmi.c
@@ -160,9 +160,9 @@ static int __init sunxi_sc_nmi_irq_init(struct device_node *node,
 
        gc = irq_get_domain_generic_chip(domain, 0);
        gc->reg_base = of_io_request_and_map(node, 0, of_node_full_name(node));
-       if (!gc->reg_base) {
+       if (IS_ERR(gc->reg_base)) {
                pr_err("unable to map resource\n");
-               ret = -ENOMEM;
+               ret = PTR_ERR(gc->reg_base);
                goto fail_irqd_remove;
        }