[PATCH 1/2] gpio: sysfs: fix gpio-chip device-attribute leak

Johan Hovold
2015-01-26T18:05:38Z

Commit 121b6a79955a3a3fd7bbb9b8cb88d5b9dad6283d upstream.

The gpio-chip device attributes were never destroyed when the device was
removed.

Fix by using device_create_with_groups() to create the device attributes
of the chip class device.

Note that this also fixes the attribute-creation race with userspace.

Fixes: d8f388d8dc8d ("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>
Signed-off-by: Johan Hovold <johan@kernel.org>
---
drivers/gpio/gpiolib.c | 19 ++++++++-----------
1 file changed, 8 insertions(+), 11 deletions(-)

diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index 0dee0e0c247a..dd4d6ffacc30 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -627,16 +627,13 @@ static ssize_t chip_ngpio_show(struct device *dev,
}
static DEVICE_ATTR(ngpio, 0444, chip_ngpio_show, NULL);

-static const struct attribute *gpiochip_attrs[] = {
+static struct attribute *gpiochip_attrs[] = {
&dev_attr_base.attr,
&dev_attr_label.attr,
&dev_attr_ngpio.attr,
NULL,
};
-
-static const struct attribute_group gpiochip_attr_group = {
- .attrs = (struct attribute **) gpiochip_attrs,
-};
+ATTRIBUTE_GROUPS(gpiochip);

/*
* /sys/class/gpio/export ... write-only
@@ -1001,13 +998,13 @@ static int gpiochip_export(struct gpio_chip *chip)

/* use chip->base for the ID; it's already known to be unique */
mutex_lock(&sysfs_lock);
- dev = device_create(&gpio_class, chip->dev, MKDEV(0, 0), chip,
- "gpiochip%d", chip->base);
- if (!IS_ERR(dev)) {
- status = sysfs_create_group(&dev->kobj,
- &gpiochip_attr_group);
- } else
+ dev = device_create_with_groups(&gpio_class, chip->dev, MKDEV(0, 0),
+ chip, gpiochip_groups,
+ "gpiochip%d", chip->base);
+ if (IS_ERR(dev))
status = PTR_ERR(dev);
+ else
+ status = 0;
chip->exported = (status == 0);
mutex_unlock(&sysfs_lock);

--
2.0.5