gpio/msic: Fix race in installing chained IRQ handler

Fix a race where a pending interrupt could be received and the handler
called before the handler's data has been setup, by converting to
irq_set_chained_handler_and_data().

Search and conversion was done with coccinelle:

@@
expression E1, E2, E3;
@@
(
-if (irq_set_chained_handler(E1, E3) != 0)
-   BUG();
|
-irq_set_chained_handler(E1, E3);
)
-irq_set_handler_data(E1, E2);
+irq_set_chained_handler_and_data(E1, E3, E2);

@@
expression E1, E2, E3;
@@
(
-if (irq_set_chained_handler(E1, E3) != 0)
-   BUG();
...
|
-irq_set_chained_handler(E1, E3);
...
)
-irq_set_handler_data(E1, E2);
+irq_set_chained_handler_and_data(E1, E3, E2);

Reported-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Julia Lawall <Julia.Lawall@lip6.fr>
Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: Alexandre Courbot <gnurou@gmail.com>
Cc: linux-gpio@vger.kernel.org

diff --git a/drivers/gpio/gpio-msic.c b/drivers/gpio/gpio-msic.c
index 01acf0a..7bcfb87 100644 (file)
--- a/drivers/gpio/gpio-msic.c
+++ b/drivers/gpio/gpio-msic.c
@@ -309,8 +309,7 @@ static int platform_msic_gpio_probe(struct platform_device *pdev)
                                         &msic_irqchip,
                                         handle_simple_irq);
        }
-       irq_set_chained_handler(mg->irq, msic_gpio_irq_handler);
-       irq_set_handler_data(mg->irq, mg);
+       irq_set_chained_handler_and_data(mg->irq, msic_gpio_irq_handler, mg);
 
        return 0;
 err: