On Thu, Feb 1, 2024 at 1:06 AM David Gow davidgow@google.com wrote:

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

Hello,

I have tested this with modules and it looks good to me!

Thanks! -Rae

Reviewed-by: Rae Moar rmoar@google.com

---

This will hopefully resolve some of the issues linked to from: https://lore.kernel.org/intel-gfx/DM4PR11MB614179CB9C387842D8E8BB40B97C2@DM4...

---

lib/kunit/device-impl.h | 2 ++ lib/kunit/device.c | 14 ++++++++++++++ lib/kunit/test.c | 3 +++ 3 files changed, 19 insertions(+)

diff --git a/lib/kunit/device-impl.h b/lib/kunit/device-impl.h index 54bd55836405..5fcd48ff0f36 100644 --- 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 074c6dd2e36a..644a38a1f5b1 100644 --- 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 31a5a992e646..1d1475578515 100644 --- 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); -- 2.43.0.429.g432eaa2c6b-goog