From: David Gow Date: Thu, 20 Jul 2023 12:45:09 +0000 (+0200) Subject: drivers: base: Free devm resources when unregistering a device X-Git-Tag: v6.6.7~2017^2~6 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=699fb50d99039a50e7494de644f96c889279aca3;p=platform%2Fkernel%2Flinux-starfive.git drivers: base: Free devm resources when unregistering a device In the current code, devres_release_all() only gets called if the device has a bus and has been probed. This leads to issues when using bus-less or driver-less devices where the device might never get freed if a managed resource holds a reference to the device. This is happening in the DRM framework for example. We should thus call devres_release_all() in the device_del() function to make sure that the device-managed actions are properly executed when the device is unregistered, even if it has neither a bus nor a driver. This is effectively the same change than commit 2f8d16a996da ("devres: release resources on device_del()") that got reverted by commit a525a3ddeaca ("driver core: free devres in device_release") over memory leaks concerns. This patch effectively combines the two commits mentioned above to release the resources both on device_del() and device_release() and get the best of both worlds. Fixes: a525a3ddeaca ("driver core: free devres in device_release") Signed-off-by: David Gow Signed-off-by: Maxime Ripard Link: https://lore.kernel.org/r/20230720-kunit-devm-inconsistencies-test-v3-3-6aa7e074f373@kernel.org Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/base/core.c b/drivers/base/core.c index 3dff503..6ceaf50 100644 --- a/drivers/base/core.c +++ b/drivers/base/core.c @@ -3817,6 +3817,17 @@ void device_del(struct device *dev) device_platform_notify_remove(dev); device_links_purge(dev); + /* + * If a device does not have a driver attached, we need to clean + * up any managed resources. We do this in device_release(), but + * it's never called (and we leak the device) if a managed + * resource holds a reference to the device. So release all + * managed resources here, like we do in driver_detach(). We + * still need to do so again in device_release() in case someone + * adds a new resource after this point, though. + */ + devres_release_all(dev); + bus_notify(dev, BUS_NOTIFY_REMOVED_DEVICE); kobject_uevent(&dev->kobj, KOBJ_REMOVE); glue_dir = get_glue_dir(dev); diff --git a/drivers/base/test/platform-device-test.c b/drivers/base/test/platform-device-test.c index b6ebf1d..1ae5ce8 100644 --- a/drivers/base/test/platform-device-test.c +++ b/drivers/base/test/platform-device-test.c @@ -87,8 +87,6 @@ static void platform_device_devm_register_get_unregister_with_devm_test(struct k struct test_priv *priv = test->priv; int ret; - kunit_skip(test, "This needs to be fixed in the core."); - pdev = platform_device_alloc(DEVICE_NAME, PLATFORM_DEVID_NONE); KUNIT_ASSERT_NOT_ERR_OR_NULL(test, pdev); diff --git a/drivers/base/test/root-device-test.c b/drivers/base/test/root-device-test.c index 9a3e6cc..780d074 100644 --- a/drivers/base/test/root-device-test.c +++ b/drivers/base/test/root-device-test.c @@ -78,8 +78,6 @@ static void root_device_devm_register_get_unregister_with_devm_test(struct kunit struct test_priv *priv = test->priv; int ret; - kunit_skip(test, "This needs to be fixed in the core."); - priv->dev = root_device_register(DEVICE_NAME); KUNIT_ASSERT_NOT_ERR_OR_NULL(test, priv->dev);