kunit: device: Unregister the kunit_bus on shutdown

If KUnit is built as a module, and it's unloaded, the kunit_bus is not
unregistered. This causes an error if it's then re-loaded later, as we
try to re-register the bus.

Unregister the bus and root_device on shutdown, if it looks valid.

In addition, be more specific about the value of kunit_bus_device. It
is:
- a valid struct device* if the kunit_bus initialised correctly.
- an ERR_PTR if it failed to initialise.
- NULL before initialisation and after shutdown.

Fixes: d03c720e03bd ("kunit: Add APIs for managing devices")
Signed-off-by: David Gow <davidgow@google.com>
Reviewed-by: Rae Moar <rmoar@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

diff --git a/lib/kunit/device-impl.h b/lib/kunit/device-impl.h
index 54bd558364053c2eb5437e0bf5b94da6cdfba0e1..5fcd48ff0f36a37415c67cf2223cdf7ffeaef794 100644 (file)
--- a/lib/kunit/device-impl.h
+++ b/lib/kunit/device-impl.h
@@ -13,5 +13,7 @@
 
 // For internal use only -- registers the kunit_bus.
 int kunit_bus_init(void);
+// For internal use only -- unregisters the kunit_bus.
+void kunit_bus_shutdown(void);
 
 #endif //_KUNIT_DEVICE_IMPL_H

diff --git a/lib/kunit/device.c b/lib/kunit/device.c
index 074c6dd2e36a7d9e8154a604db7c2a8e4f669921..644a38a1f5b1cf0686a67e7df1a366a3d84e61a6 100644 (file)
--- a/lib/kunit/device.c
+++ b/lib/kunit/device.c
@@ -54,6 +54,20 @@ int kunit_bus_init(void)
        return error;
 }
 
+/* Unregister the 'kunit_bus' in case the KUnit module is unloaded. */
+void kunit_bus_shutdown(void)
+{
+       /* Make sure the bus exists before we unregister it. */
+       if (IS_ERR_OR_NULL(kunit_bus_device))
+               return;
+
+       bus_unregister(&kunit_bus_type);
+
+       root_device_unregister(kunit_bus_device);
+
+       kunit_bus_device = NULL;
+}
+
 /* Release a 'fake' KUnit device. */
 static void kunit_device_release(struct device *d)
 {

diff --git a/lib/kunit/test.c b/lib/kunit/test.c
index 31a5a992e64670f35a9717659f99ca1b385d5f2e..1d1475578515c261fe74b454502f1a2a5ac3bb81 100644 (file)
--- a/lib/kunit/test.c
+++ b/lib/kunit/test.c
@@ -928,6 +928,9 @@ static void __exit kunit_exit(void)
 #ifdef CONFIG_MODULES
        unregister_module_notifier(&kunit_mod_nb);
 #endif
+
+       kunit_bus_shutdown();
+
        kunit_debugfs_cleanup();
 }
 module_exit(kunit_exit);