gpio: sysfs: fix memory leaks and device hotplug

[pandora-kernel.git] / drivers / gpio / gpiolib-sysfs.c

diff --git a/drivers/gpio/gpiolib-sysfs.c b/drivers/gpio/gpiolib-sysfs.c
index 7722ed5..af3bc7a 100644 (file)
--- a/drivers/gpio/gpiolib-sysfs.c
+++ b/drivers/gpio/gpiolib-sysfs.c
@@ -551,6 +551,7 @@ static struct class gpio_class = {
  */
 int gpiod_export(struct gpio_desc *desc, bool direction_may_change)
 {
+       struct gpio_chip        *chip;
        unsigned long           flags;
        int                     status;
        const char              *ioname = NULL;
@@ -568,8 +569,16 @@ int gpiod_export(struct gpio_desc *desc, bool direction_may_change)
                return -EINVAL;
        }
 
+       chip = desc->chip;
+
        mutex_lock(&sysfs_lock);
 
+       /* check if chip is being removed */
+       if (!chip || !chip->exported) {
+               status = -ENODEV;
+               goto fail_unlock;
+       }
+
        spin_lock_irqsave(&gpio_lock, flags);
        if (!test_bit(FLAG_REQUESTED, &desc->flags) ||
             test_bit(FLAG_EXPORT, &desc->flags)) {
@@ -783,12 +792,15 @@ void gpiochip_unexport(struct gpio_chip *chip)
 {
        int                     status;
        struct device           *dev;
+       struct gpio_desc *desc;
+       unsigned int i;
 
        mutex_lock(&sysfs_lock);
        dev = class_find_device(&gpio_class, NULL, chip, match_export);
        if (dev) {
                put_device(dev);
                device_unregister(dev);
+               /* prevent further gpiod exports */
                chip->exported = false;
                status = 0;
        } else
@@ -797,6 +809,13 @@ void gpiochip_unexport(struct gpio_chip *chip)
 
        if (status)
                chip_dbg(chip, "%s: status %d\n", __func__, status);
+
+       /* unregister gpiod class devices owned by sysfs */
+       for (i = 0; i < chip->ngpio; i++) {
+               desc = &chip->desc[i];
+               if (test_and_clear_bit(FLAG_SYSFS, &desc->flags))
+                       gpiod_free(desc);
+       }
 }
 
 static int __init gpiolib_sysfs_init(void)