Fix locking problem, race conditions and resource leaks in em28xx, em28xx-dvb

@@ -1160,10 +1160,9 @@
 static DEFINE_MUTEX(em28xx_devlist_mutex);
 
 /*
- * em28xx_realease_resources()
- * unregisters the v4l2,i2c and usb devices
- * called when the device gets disconected or at module unload
-*/
+ * em28xx_remove_from_devlist()
+ * Removes the device from the list of active devices.
+ */
 void em28xx_remove_from_devlist(struct em28xx *dev)
 {
 	mutex_lock(&em28xx_devlist_mutex);

@@ -1171,13 +1170,6 @@
 	mutex_unlock(&em28xx_devlist_mutex);
 };
 
-void em28xx_add_into_devlist(struct em28xx *dev)
-{
-	mutex_lock(&em28xx_devlist_mutex);
-	list_add_tail(&dev->devlist, &em28xx_devlist);
-	mutex_unlock(&em28xx_devlist_mutex);
-};
-
 /*
  * Extension interface
  */

@@ -1193,8 +1185,8 @@
 	list_for_each_entry(dev, &em28xx_devlist, devlist) {
 		ops->init(dev);
 	}
-	printk(KERN_INFO "Em28xx: Initialized (%s) extension\n", ops->name);
 	mutex_unlock(&em28xx_devlist_mutex);
+	printk(KERN_INFO "Em28xx: Initialized (%s) extension\n", ops->name);
 	return 0;
 }
 EXPORT_SYMBOL(em28xx_register_extension);

@@ -1207,9 +1199,9 @@
 	list_for_each_entry(dev, &em28xx_devlist, devlist) {
 		ops->fini(dev);
 	}
-	printk(KERN_INFO "Em28xx: Removed (%s) extension\n", ops->name);
 	list_del(&ops->next);
 	mutex_unlock(&em28xx_devlist_mutex);
+	printk(KERN_INFO "Em28xx: Removed (%s) extension\n", ops->name);
 }
 EXPORT_SYMBOL(em28xx_unregister_extension);
 

@@ -1218,11 +1210,10 @@
 	struct em28xx_ops *ops = NULL;
 
 	mutex_lock(&em28xx_devlist_mutex);
-	if (!list_empty(&em28xx_extension_devlist)) {
-		list_for_each_entry(ops, &em28xx_extension_devlist, next) {
-			if (ops->init)
-				ops->init(dev);
-		}
+	list_add_tail(&dev->devlist, &em28xx_devlist);
+	list_for_each_entry(ops, &em28xx_extension_devlist, next) {
+		if (ops->init)
+			ops->init(dev);
 	}
 	mutex_unlock(&em28xx_devlist_mutex);
 }

171 lines not on this page · raw message

@@ -542,7 +542,6 @@
 	dev->dvb = dvb;
 	dvb->fe[0] = dvb->fe[1] = NULL;
 
-	mutex_lock(&dev->lock);
 	em28xx_set_mode(dev, EM28XX_DIGITAL_MODE);
 	/* init frontend */
 	switch (dev->model) {

@@ -711,7 +710,6 @@
 	em28xx_info("Successfully loaded em28xx-dvb\n");
 ret:
 	em28xx_set_mode(dev, EM28XX_SUSPEND);
-	mutex_unlock(&dev->lock);
 	return result;
 
 out_free: