[PATCH 3.16.y-ckt 017/135] gpio: fix memory leak and sleep-while-atomic

[Luis Henriques]

3.16.7-ckt6 -stable review patch.  If anyone has any objections, please let me know.

------------------

From: Johan Hovold <johan@xxxxxxxxxx>

commit 00acc3dc248063f982cfacfbe5e78c0d6797ffef upstream.

Fix memory leak and sleep-while-atomic in gpiochip_remove.

The memory leak was introduced by afa82fab5e13 ("gpio / ACPI: Move event
handling registration to gpiolib irqchip helpers") that moved the
release of acpi interrupt resources to gpiochip_irqchip_remove, but by
then the resources are no longer accessible as the acpi_gpio_chip has
already been freed by acpi_gpiochip_remove.

Note that this also fixes a few potential sleep-while-atomics, which has
been around since 1425052097b5 ("gpio: add IRQ chip helpers in gpiolib")
when the call to gpiochip_irqchip_remove while holding a spinlock was
added (a couple of irq-domain paths can end up grabbing mutexes).

Fixes: afa82fab5e13 ("gpio / ACPI: Move event handling registration to
gpiolib irqchip helpers")
Fixes: 1425052097b5 ("gpio: add IRQ chip helpers in gpiolib")

Signed-off-by: Johan Hovold <johan@xxxxxxxxxx>
Signed-off-by: Linus Walleij <linus.walleij@xxxxxxxxxx>
Signed-off-by: Luis Henriques <luis.henriques@xxxxxxxxxxxxx>
---
 drivers/gpio/gpiolib.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index aea93a2f69b4..2c7157705e71 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -1272,11 +1272,12 @@ int gpiochip_remove(struct gpio_chip *chip)
 	int		status = 0;
 	unsigned	id;
 
+	gpiochip_irqchip_remove(chip);
+
 	acpi_gpiochip_remove(chip);
 
 	spin_lock_irqsave(&gpio_lock, flags);
 
-	gpiochip_irqchip_remove(chip);
 	gpiochip_remove_pin_ranges(chip);
 	of_gpiochip_remove(chip);
 
-- 
2.1.4

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