[3.16.y-ckt stable] Patch "gpio: fix memory leak and sleep-while-atomic" has been added to staging queue

[Luis Henriques]

This is a note to let you know that I have just added a patch titled

    gpio: fix memory leak and sleep-while-atomic

to the linux-3.16.y-queue branch of the 3.16.y-ckt extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.16.y-queue

This patch is scheduled to be released in version 3.16.7-ckt6.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.16.y-ckt tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Luis

------

>From 356a997cf9fe0185735aa416097cb7281c9b0d9f Mon Sep 17 00:00:00 2001
From: Johan Hovold <johan at kernel.org>
Date: Mon, 12 Jan 2015 17:12:27 +0100
Subject: gpio: fix memory leak and sleep-while-atomic

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 at kernel.org>
Signed-off-by: Linus Walleij <linus.walleij at linaro.org>
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 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