releases/3.10.67/gpio-sysfs-fix-gpio-device-attribute-leak.patch

   1 From 0915e6feb38de8d3601819992a5bd050201a56fa Mon Sep 17 00:00:00 2001
   2 From: Johan Hovold <johan@kernel.org>
   3 Date: Tue, 13 Jan 2015 13:00:05 +0100
   4 Subject: gpio: sysfs: fix gpio device-attribute leak
   5
   6 From: Johan Hovold <johan@kernel.org>
   7
   8 commit 0915e6feb38de8d3601819992a5bd050201a56fa upstream.
   9
  10 The gpio device attributes were never destroyed when the gpio was
  11 unexported (or on export failures).
  12
  13 Use device_create_with_groups() to create the default device attributes
  14 of the gpio class device. Note that this also fixes the
  15 attribute-creation race with userspace for these attributes.
  16
  17 Remove contingent attributes in export error path and on unexport.
  18
  19 Fixes: d8f388d8dc8d ("gpio: sysfs interface")
  20 Cc: stable <stable@vger.kernel.org>     # v2.6.27+
  21 Signed-off-by: Johan Hovold <johan@kernel.org>
  22 Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
  23 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
  24
  25 ---
  26  drivers/gpio/gpiolib.c |   19 +++++++++++++------
  27  1 file changed, 13 insertions(+), 6 deletions(-)
  28
  29 --- a/drivers/gpio/gpiolib.c
  30 +++ b/drivers/gpio/gpiolib.c
  31 @@ -362,7 +362,7 @@ static ssize_t gpio_value_store(struct d
  32         return status;
  33  }
  34
  35 -static const DEVICE_ATTR(value, 0644,
  36 +static DEVICE_ATTR(value, 0644,
  37                 gpio_value_show, gpio_value_store);
  38
  39  static irqreturn_t gpio_sysfs_irq(int irq, void *priv)
  40 @@ -580,17 +580,17 @@ static ssize_t gpio_active_low_store(str
  41         return status ? : size;
  42  }
  43
  44 -static const DEVICE_ATTR(active_low, 0644,
  45 +static DEVICE_ATTR(active_low, 0644,
  46                 gpio_active_low_show, gpio_active_low_store);
  47
  48 -static const struct attribute *gpio_attrs[] = {
  49 +static struct attribute *gpio_attrs[] = {
  50         &dev_attr_value.attr,
  51         &dev_attr_active_low.attr,
  52         NULL,
  53  };
  54
  55  static const struct attribute_group gpio_attr_group = {
  56 -       .attrs = (struct attribute **) gpio_attrs,
  57 +       .attrs = gpio_attrs,
  58  };
  59
  60  /*
  61 @@ -806,20 +806,24 @@ static int gpiod_export(struct gpio_desc
  62         if (direction_may_change) {
  63                 status = device_create_file(dev, &dev_attr_direction);
  64                 if (status)
  65 -                       goto fail_unregister_device;
  66 +                       goto fail_remove_attr_group;
  67         }
  68
  69         if (gpiod_to_irq(desc) >= 0 && (direction_may_change ||
  70                                        !test_bit(FLAG_IS_OUT, &desc->flags))) {
  71                 status = device_create_file(dev, &dev_attr_edge);
  72                 if (status)
  73 -                       goto fail_unregister_device;
  74 +                       goto fail_remove_attr_direction;
  75         }
  76
  77         set_bit(FLAG_EXPORT, &desc->flags);
  78         mutex_unlock(&sysfs_lock);
  79         return 0;
  80
  81 +fail_remove_attr_direction:
  82 +       device_remove_file(dev, &dev_attr_direction);
  83 +fail_remove_attr_group:
  84 +       sysfs_remove_group(&dev->kobj, &gpio_attr_group);
  85  fail_unregister_device:
  86         device_unregister(dev);
  87  fail_unlock:
  88 @@ -971,6 +975,9 @@ static void gpiod_unexport(struct gpio_d
  89         mutex_unlock(&sysfs_lock);
  90
  91         if (dev) {
  92 +               device_remove_file(dev, &dev_attr_edge);
  93 +               device_remove_file(dev, &dev_attr_direction);
  94 +               sysfs_remove_group(&dev->kobj, &gpio_attr_group);
  95                 device_unregister(dev);
  96                 put_device(dev);
  97         }