[PATCH v2 2/7] drivers/base: Verify struct device locking requirements at runtime

[Bart Van Assche <bvanassche@xxxxxxx>]

Make sure that a complaint appears in the kernel log if the driver core
locking assumptions are violated.

Cc: Lee Duncan <lduncan@xxxxxxxx>
Cc: Hannes Reinecke <hare@xxxxxxxx>
Cc: Luis Chamberlain <mcgrof@xxxxxxxxxx>
Cc: Johannes Thumshirn <jthumshirn@xxxxxxx>
Cc: Christoph Hellwig <hch@xxxxxx>
Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Bart Van Assche <bvanassche@xxxxxxx>
---
 drivers/base/dd.c     | 16 ++++++++++++++++
 drivers/base/memory.c |  4 ++++
 2 files changed, 20 insertions(+)

diff --git a/drivers/base/dd.c b/drivers/base/dd.c
index b4212154a94b..033382421351 100644
--- a/drivers/base/dd.c
+++ b/drivers/base/dd.c
@@ -315,11 +315,15 @@ __exitcall(deferred_probe_exit);
  */
 bool device_is_bound(struct device *dev)
 {
+	lockdep_assert_held(&dev->mutex);
+
 	return dev->p && klist_node_attached(&dev->p->knode_driver);
 }
 
 static void driver_bound(struct device *dev)
 {
+	lockdep_assert_held(&dev->mutex);
+
 	if (device_is_bound(dev)) {
 		printk(KERN_WARNING "%s: device %s already bound\n",
 			__func__, kobject_name(&dev->kobj));
@@ -363,6 +367,8 @@ static int driver_sysfs_add(struct device *dev)
 {
 	int ret;
 
+	lockdep_assert_held(&dev->mutex);
+
 	if (dev->bus)
 		blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
 					     BUS_NOTIFY_BIND_DRIVER, dev);
@@ -421,6 +427,8 @@ int device_bind_driver(struct device *dev)
 {
 	int ret;
 
+	lockdep_assert_held(&dev->mutex);
+
 	ret = driver_sysfs_add(dev);
 	if (!ret)
 		driver_bound(dev);
@@ -450,6 +458,8 @@ static int really_probe(struct device *dev, struct device_driver *drv)
 	bool test_remove = IS_ENABLED(CONFIG_DEBUG_TEST_DRIVER_REMOVE) &&
 			   !drv->suppress_bind_attrs;
 
+	lockdep_assert_held(&dev->mutex);
+
 	if (defer_all_probes) {
 		/*
 		 * Value of defer_all_probes can be set only by
@@ -589,6 +599,8 @@ static int really_probe_debug(struct device *dev, struct device_driver *drv)
 	ktime_t calltime, delta, rettime;
 	int ret;
 
+	lockdep_assert_held(&dev->mutex);
+
 	calltime = ktime_get();
 	ret = really_probe(dev, drv);
 	rettime = ktime_get();
@@ -645,6 +657,8 @@ int driver_probe_device(struct device_driver *drv, struct device *dev)
 {
 	int ret = 0;
 
+	lockdep_assert_held(&dev->mutex);
+
 	/*
 	 * Several callers check the driver pointer without holding the
 	 * device mutex. Hence check the driver pointer again while holding
@@ -932,6 +946,8 @@ static void __device_release_driver(struct device *dev, struct device *parent)
 {
 	struct device_driver *drv;
 
+	lockdep_assert_held(&dev->mutex);
+
 	drv = dev->driver;
 	if (drv) {
 		if (driver_allows_async_probing(drv))
diff --git a/drivers/base/memory.c b/drivers/base/memory.c
index c8a1cb0b6136..41a8454dabb5 100644
--- a/drivers/base/memory.c
+++ b/drivers/base/memory.c
@@ -283,6 +283,8 @@ static int memory_subsys_online(struct device *dev)
 	struct memory_block *mem = to_memory_block(dev);
 	int ret;
 
+	lockdep_assert_held(&dev->mutex);
+
 	if (mem->state == MEM_ONLINE)
 		return 0;
 
@@ -307,6 +309,8 @@ static int memory_subsys_offline(struct device *dev)
 {
 	struct memory_block *mem = to_memory_block(dev);
 
+	lockdep_assert_held(&dev->mutex);
+
 	if (mem->state == MEM_OFFLINE)
 		return 0;
 
-- 
2.19.1.568.g152ad8e336-goog