1 files changed, 22 insertions, 8 deletions

diff --git a/drivers/base/core.c b/drivers/base/core.c
index da84a73f2ba6..636058bbf48a 100644
--- a/drivers/base/core.c
+++ b/drivers/base/core.c
@@ -1663,6 +1663,9 @@ void device_initialize(struct device *dev)
         kobject_init(&dev->kobj, &device_ktype);
         INIT_LIST_HEAD(&dev->dma_pools);
         mutex_init(&dev->mutex);
+#ifdef CONFIG_PROVE_LOCKING
+        mutex_init(&dev->lockdep_mutex);
+#endif
         lockdep_set_novalidate_class(&dev->mutex);
         spin_lock_init(&dev->devres_lock);
         INIT_LIST_HEAD(&dev->devres_head);
@@ -2211,6 +2214,24 @@ void put_device(struct device *dev)
 }
 EXPORT_SYMBOL_GPL(put_device);
 
+bool kill_device(struct device *dev)
+{
+        /*
+         * Require the device lock and set the "dead" flag to guarantee that
+         * the update behavior is consistent with the other bitfields near
+         * it and that we cannot have an asynchronous probe routine trying
+         * to run while we are tearing out the bus/class/sysfs from
+         * underneath the device.
+         */
+        lockdep_assert_held(&dev->mutex);
+
+        if (dev->p->dead)
+                return false;
+        dev->p->dead = true;
+        return true;
+}
+EXPORT_SYMBOL_GPL(kill_device);
+
 /**
  * device_del - delete device from system.
  * @dev: device.
@@ -2230,15 +2251,8 @@ void device_del(struct device *dev)
         struct kobject *glue_dir = NULL;
         struct class_interface *class_intf;
 
-        /*
-         * Hold the device lock and set the "dead" flag to guarantee that
-         * the update behavior is consistent with the other bitfields near
-         * it and that we cannot have an asynchronous probe routine trying
-         * to run while we are tearing out the bus/class/sysfs from
-         * underneath the device.
-         */
         device_lock(dev);
-        dev->p->dead = true;
+        kill_device(dev);
         device_unlock(dev);
 
         /* Notify clients of device removal.  This call must come