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gpio: sysfs: fix gpio device-attribute leak 

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: d8f388d8dc ("gpio: sysfs interface")
Cc: stable <stable@vger.kernel.org>	# v2.6.27+
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
This commit is contained in:
Johan Hovold 2015-01-13 13:00:05 +01:00 committed by Linus Walleij
parent 121b6a7995
commit 0915e6feb3
1 changed files with 13 additions and 15 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

28
drivers/gpio/gpiolib-sysfs.c
View File

@ -128,7 +128,7 @@ 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)
@ -353,18 +353,15 @@ 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/
@ -561,18 +558,15 @@ 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)
@ -583,13 +577,15 @@ 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:
@ -723,6 +719,8 @@ void gpiod_unexport(struct gpio_desc *desc)
mutex_unlock(&sysfs_lock);
if (dev) {
device_remove_file(dev, &dev_attr_edge);
device_remove_file(dev, &dev_attr_direction);
device_unregister(dev);
put_device(dev);
}