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Commit 0254e953 authored by Guenter Roeck's avatar Guenter Roeck Committed by Wim Van Sebroeck
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watchdog: Drop pointer to watchdog device from struct watchdog_device 



The lifetime of the watchdog device pointer is different from the lifetime
of its character device. Remove it entirely to avoid race conditions.

Signed-off-by: default avatarGuenter Roeck <linux@roeck-us.net>
Signed-off-by: default avatarGuenter Roeck <linux@roeck-us.net>
Signed-off-by: default avatarWim Van Sebroeck <wim@iguana.be>
parent 2c2f3080

Documentation/watchdog/watchdog-kernel-api.txt

+0 −2
Original line number Diff line number Diff line
@@ -44,7 +44,6 @@ The watchdog device structure looks like this: 


struct watchdog_device {

	int id;

	struct device *dev;

	struct device *parent;

	const struct attribute_group **groups;

	const struct watchdog_info *info;
@@ -66,7 +65,6 @@ It contains following fields: 
  /dev/watchdog0 cdev (dynamic major, minor 0) as well as the old

  /dev/watchdog miscdev. The id is set automatically when calling

  watchdog_register_device.

* dev: device under the watchdog class (created by watchdog_register_device).

* parent: set this to the parent device (or NULL) before calling

  watchdog_register_device.

* groups: List of sysfs attribute groups to create when creating the watchdog

drivers/watchdog/watchdog_core.c

+4 −4
Original line number Diff line number Diff line
@@ -249,8 +249,8 @@ static int __watchdog_register_device(struct watchdog_device *wdd) 


		ret = register_reboot_notifier(&wdd->reboot_nb);

		if (ret) {

			dev_err(wdd->dev, "Cannot register reboot notifier (%d)\n",

				ret);

			pr_err("watchdog%d: Cannot register reboot notifier (%d)\n",

			       wdd->id, ret);

			watchdog_dev_unregister(wdd);

			ida_simple_remove(&watchdog_ida, wdd->id);

			return ret;
@@ -262,8 +262,8 @@ static int __watchdog_register_device(struct watchdog_device *wdd) 


		ret = register_restart_handler(&wdd->restart_nb);

		if (ret)

			dev_warn(wdd->dev, "Cannot register restart handler (%d)\n",

				 ret);

			pr_warn("watchog%d: Cannot register restart handler (%d)\n",

				wdd->id, ret);

	}



	return 0;

drivers/watchdog/watchdog_dev.c

+4 −5
Original line number Diff line number Diff line
@@ -143,7 +143,8 @@ static int watchdog_stop(struct watchdog_device *wdd) 
		return 0;



	if (test_bit(WDOG_NO_WAY_OUT, &wdd->status)) {

		dev_info(wdd->dev, "nowayout prevents watchdog being stopped!\n");

		pr_info("watchdog%d: nowayout prevents watchdog being stopped!\n",

			wdd->id);

		return -EBUSY;

	}
@@ -604,7 +605,7 @@ static int watchdog_release(struct inode *inode, struct file *file) 


	/* If the watchdog was not stopped, send a keepalive ping */

	if (err < 0) {

		dev_crit(wdd->dev, "watchdog did not stop!\n");

		pr_crit("watchdog%d: watchdog did not stop!\n", wdd->id);

		watchdog_ping(wdd);

	}
@@ -751,7 +752,6 @@ int watchdog_dev_register(struct watchdog_device *wdd) 
		watchdog_cdev_unregister(wdd);

		return PTR_ERR(dev);

	}

	wdd->dev = dev;



	return ret;

}
@@ -766,8 +766,7 @@ int watchdog_dev_register(struct watchdog_device *wdd) 


void watchdog_dev_unregister(struct watchdog_device *wdd)

{

	device_destroy(&watchdog_class, wdd->dev->devt);

	wdd->dev = NULL;

	device_destroy(&watchdog_class, wdd->wd_data->cdev.dev);

	watchdog_cdev_unregister(wdd);

}

include/linux/watchdog.h

+0 −2
Original line number Diff line number Diff line
@@ -53,7 +53,6 @@ struct watchdog_ops { 
/** struct watchdog_device - The structure that defines a watchdog device

 *

 * @id:		The watchdog's ID. (Allocated by watchdog_register_device)

 * @dev:	The device for our watchdog

 * @parent:	The parent bus device

 * @groups:	List of sysfs attribute groups to create when creating the

 *		watchdog device.
@@ -82,7 +81,6 @@ struct watchdog_ops { 
 */

struct watchdog_device {

	int id;

	struct device *dev;

	struct device *parent;

	const struct attribute_group **groups;

	const struct watchdog_info *info;