target/linux/generic/patches-3.12/864-gpiommc_configfs_locking.patch

   1 The gpiommc configfs context structure needs locking, as configfs
   2 does not lock access between files.
   3
   4 --- a/drivers/mmc/host/gpiommc.c
   5 +++ b/drivers/mmc/host/gpiommc.c
   6 @@ -144,6 +144,8 @@ struct gpiommc_configfs_device {
   7         struct platform_device *pdev;
   8         /* The configuration */
   9         struct gpiommc_platform_data pdata;
  10 +       /* Mutex to protect this structure */
  11 +       struct mutex mutex;
  12  };
  13
  14  #define GPIO_INVALID   -1
  15 @@ -234,6 +236,8 @@ static ssize_t gpiommc_config_attr_show(
  16         unsigned int gpio;
  17         int err = 0;
  18
  19 +       mutex_lock(&dev->mutex);
  20 +
  21         if (attr == &gpiommc_attr_DI) {
  22                 gpio = dev->pdata.pins.gpio_di;
  23                 if (gpio == GPIO_INVALID)
  24 @@ -294,6 +298,8 @@ static ssize_t gpiommc_config_attr_show(
  25         WARN_ON(1);
  26         err = -ENOSYS;
  27  out:
  28 +       mutex_unlock(&dev->mutex);
  29 +
  30         return err ? err : count;
  31  }
  32
  33 @@ -353,6 +359,8 @@ static ssize_t gpiommc_config_attr_store
  34         int err = -EINVAL;
  35         unsigned long data;
  36
  37 +       mutex_lock(&dev->mutex);
  38 +
  39         if (attr == &gpiommc_attr_register) {
  40                 err = kstrtoul(page, 10, &data);
  41                 if (err)
  42 @@ -478,6 +486,8 @@ static ssize_t gpiommc_config_attr_store
  43         WARN_ON(1);
  44         err = -ENOSYS;
  45  out:
  46 +       mutex_unlock(&dev->mutex);
  47 +
  48         return err ? err : count;
  49  }
  50
  51 @@ -514,6 +524,7 @@ static struct config_item *gpiommc_make_
  52         if (!dev)
  53                 return NULL;
  54
  55 +       mutex_init(&dev->mutex);
  56         config_item_init_type_name(&dev->item, name,
  57                                    &gpiommc_dev_ci_type);
  58