gpio: Fix potential NULL handler data in chained irqchip handler

commit 324b0398781e7afb846378dd2d8a4374faaf236b upstream.

There is possibility with misconfigured pins that interrupt occurs instantly
after setting irq_set_chained_handler() in gpiochip_set_chained_irqchip().
Now if handler gets called before irq_set_handler_data() the handler gets
NULL handler data.

Fix this by moving irq_set_handler_data() call before
irq_set_chained_handler() in gpiochip_set_chained_irqchip().

Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index 2ebc9071e354884a80de8c17a978ba7bb3d28077..810c84fd00c496cea9567fde5a693d47d77237dd 100644 (file)
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -1368,12 +1368,12 @@ void gpiochip_set_chained_irqchip(struct gpio_chip *gpiochip,
                return;
        }
 
-       irq_set_chained_handler(parent_irq, parent_handler);
        /*
         * The parent irqchip is already using the chip_data for this
         * irqchip, so our callbacks simply use the handler_data.
         */
        irq_set_handler_data(parent_irq, gpiochip);
+       irq_set_chained_handler(parent_irq, parent_handler);
 }
 EXPORT_SYMBOL_GPL(gpiochip_set_chained_irqchip);