[PATCH 2/3] gpio: sysfs: fix gpio device-attribute leak
From: Johan Hovold <johan@kernel.org>
Date: 2015-01-13 12:00:37
Also in:
lkml, stable
Subsystem:
gpio subsystem, the rest · Maintainers:
Linus Walleij, Bartosz Golaszewski, Linus Torvalds
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")
Cc: stable <redacted> # v2.6.27+
Signed-off-by: Johan Hovold <johan@kernel.org>
---
drivers/gpio/gpiolib-sysfs.c | 28 +++++++++++++---------------
1 file changed, 13 insertions(+), 15 deletions(-)
diff --git a/drivers/gpio/gpiolib-sysfs.c b/drivers/gpio/gpiolib-sysfs.c
index 33cf4bd0ed2d..fd4d9423f6e6 100644
--- a/drivers/gpio/gpiolib-sysfs.c
+++ b/drivers/gpio/gpiolib-sysfs.c@@ -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); }
--
2.0.5