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authorRicardo Ribalda Delgado2016-06-03 19:10:02 +0200
committerLinus Walleij2016-06-08 10:40:29 +0200
commitf4833b8cc7edab57d3f3033e549111a546c2e02b (patch)
tree9ec107aa22c29db288c6444ee21d3f1be5521266 /drivers/gpio
parent11f33a6d15bfa397867ac0d7f3481b6dd683286f (diff)
gpiolib: Fix unaligned used of reference counters
gpiolib relies on the reference counters to clean up the gpio_device structure. Although the number of get/put is properly aligned on gpiolib.c itself, it does not take into consideration how the referece counters are affected by other external functions such as cdev_add and device_add. Because of this, after the last call to put_device, the reference counter has a value of +3, therefore never calling gpiodevice_release. Due to the fact that some of the device has already been cleaned on gpiochip_remove, the library will end up OOPsing the kernel (e.g. a call to of_gpiochip_find_and_xlate). Cc: stable@vger.kernel.org Signed-off-by: Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Diffstat (limited to 'drivers/gpio')
-rw-r--r--drivers/gpio/gpiolib.c4
1 files changed, 2 insertions, 2 deletions
diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index a2c31a5a677f..58d822d7e8da 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -449,7 +449,6 @@ static void gpiodevice_release(struct device *dev)
{
struct gpio_device *gdev = dev_get_drvdata(dev);
- cdev_del(&gdev->chrdev);
list_del(&gdev->list);
ida_simple_remove(&gpio_ida, gdev->id);
kfree(gdev->label);
@@ -482,7 +481,6 @@ static int gpiochip_setup_dev(struct gpio_device *gdev)
/* From this point, the .release() function cleans up gpio_device */
gdev->dev.release = gpiodevice_release;
- get_device(&gdev->dev);
pr_debug("%s: registered GPIOs %d to %d on device: %s (%s)\n",
__func__, gdev->base, gdev->base + gdev->ngpio - 1,
dev_name(&gdev->dev), gdev->chip->label ? : "generic");
@@ -770,6 +768,8 @@ void gpiochip_remove(struct gpio_chip *chip)
* be removed, else it will be dangling until the last user is
* gone.
*/
+ cdev_del(&gdev->chrdev);
+ device_del(&gdev->dev);
put_device(&gdev->dev);
}
EXPORT_SYMBOL_GPL(gpiochip_remove);