From: Johan Hovold <jo...@kernel.org>

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

===============

commit 0915e6feb38de8d3601819992a5bd050201a56fa upstream.

The gpio device attributes were never destroyed when the gpio was
unexported (or on export failures).

Use device_create_with_groups() to create the default device attributes
of the gpio class device. Note that this also fixes the
attribute-creation race with userspace for these attributes.

Remove contingent attributes in export error path and on unexport.

Fixes: d8f388d8dc8d ("gpio: sysfs interface")
Signed-off-by: Johan Hovold <jo...@kernel.org>
Signed-off-by: Linus Walleij <linus.wall...@linaro.org>
Signed-off-by: Jiri Slaby <jsl...@suse.cz>
---
 drivers/gpio/gpiolib.c | 27 +++++++++++++--------------
 1 file changed, 13 insertions(+), 14 deletions(-)

diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index b5d0fff2cd5a..1cd034e428b5 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -362,7 +362,7 @@ static ssize_t gpio_value_store(struct device *dev,
        return status;
 }
 
-static const DEVICE_ATTR(value, 0644,
+static DEVICE_ATTR(value, 0644,
                gpio_value_show, gpio_value_store);
 
 static irqreturn_t gpio_sysfs_irq(int irq, void *priv)
@@ -580,18 +580,16 @@ static ssize_t gpio_active_low_store(struct device *dev,
        return status ? : size;
 }
 
-static const DEVICE_ATTR(active_low, 0644,
+static DEVICE_ATTR(active_low, 0644,
                gpio_active_low_show, gpio_active_low_store);
 
-static const struct attribute *gpio_attrs[] = {
+static struct attribute *gpio_attrs[] = {
        &dev_attr_value.attr,
        &dev_attr_active_low.attr,
        NULL,
 };
 
-static const struct attribute_group gpio_attr_group = {
-       .attrs = (struct attribute **) gpio_attrs,
-};
+ATTRIBUTE_GROUPS(gpio);
 
 /*
  * /sys/class/gpio/gpiochipN/
@@ -788,18 +786,15 @@ static int gpiod_export(struct gpio_desc *desc, bool 
direction_may_change)
        if (desc->chip->names && desc->chip->names[offset])
                ioname = desc->chip->names[offset];
 
-       dev = device_create(&gpio_class, desc->chip->dev, MKDEV(0, 0),
-                           desc, ioname ? ioname : "gpio%u",
-                           desc_to_gpio(desc));
+       dev = device_create_with_groups(&gpio_class, desc->chip->dev,
+                                       MKDEV(0, 0), desc, gpio_groups,
+                                       ioname ? ioname : "gpio%u",
+                                       desc_to_gpio(desc));
        if (IS_ERR(dev)) {
                status = PTR_ERR(dev);
                goto fail_unlock;
        }
 
-       status = sysfs_create_group(&dev->kobj, &gpio_attr_group);
-       if (status)
-               goto fail_unregister_device;
-
        if (direction_may_change) {
                status = device_create_file(dev, &dev_attr_direction);
                if (status)
@@ -810,13 +805,15 @@ static int gpiod_export(struct gpio_desc *desc, bool 
direction_may_change)
                                       !test_bit(FLAG_IS_OUT, &desc->flags))) {
                status = device_create_file(dev, &dev_attr_edge);
                if (status)
-                       goto fail_unregister_device;
+                       goto fail_remove_attr_direction;
        }
 
        set_bit(FLAG_EXPORT, &desc->flags);
        mutex_unlock(&sysfs_lock);
        return 0;
 
+fail_remove_attr_direction:
+       device_remove_file(dev, &dev_attr_direction);
 fail_unregister_device:
        device_unregister(dev);
 fail_unlock:
@@ -959,6 +956,8 @@ static void gpiod_unexport(struct gpio_desc *desc)
 
                dev = class_find_device(&gpio_class, NULL, desc, match_export);
                if (dev) {
+                       device_remove_file(dev, &dev_attr_edge);
+                       device_remove_file(dev, &dev_attr_direction);
                        gpio_setup_irq(desc, dev, 0);
                        clear_bit(FLAG_EXPORT, &desc->flags);
                } else
-- 
2.2.2

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