Calling platform_device_set_fwnode() (and by extension: platform_device_set_of_node()) of platform_device_set_of_node_from_dev() for a dynamically allocated platform device whose primary firmware node is already assigned and is a software node leads to a resource leak as we never perform the corresponding call to software_node_notify_remove(). As there are currently no users for this special case - just disallow it and warn loudly if it ever happens.
Signed-off-by: Bartosz Golaszewski <[email protected]> --- drivers/base/platform.c | 21 ++++++++++++++++++--- 1 file changed, 18 insertions(+), 3 deletions(-) diff --git a/drivers/base/platform.c b/drivers/base/platform.c index a71015f1d915340aa01ebfae67196d4d7ccecba8..fb57d487a6c2aba799b4ca5ccd089006cf2d8bf6 100644 --- a/drivers/base/platform.c +++ b/drivers/base/platform.c @@ -707,7 +707,9 @@ EXPORT_SYMBOL_GPL(platform_device_add_data); * * Assign an OF node to this platform device. Internally keep track of the * reference count. Devices created with platform_device_alloc() must use this - * function instead of assigning the node manually. + * function instead of assigning the node manually. This function must not be + * called for a platform device that already has a software node as its primary + * firmware node assigned. */ void platform_device_set_of_node(struct platform_device *pdev, struct device_node *np) @@ -723,11 +725,20 @@ EXPORT_SYMBOL_GPL(platform_device_set_of_node); * * Assign a firmware node to this platform device. Internally keep track of the * reference count. Devices created with platform_device_alloc() must use this - * function instead of assigning the node manually. + * function instead of assigning the node manually. This function must not be + * called for a platform device that already has a software node as its primary + * firmware node assigned. */ void platform_device_set_fwnode(struct platform_device *pdev, struct fwnode_handle *fwnode) { + /* + * If we call this function for a platform device whose primary + * firmware node is a software node, we'll never end up calling the + * symmetric software_node_notify_remove(). There are no users for this + * right now in the tree so just disallow it. + */ + WARN_ON(is_software_node(dev_fwnode(&pdev->dev))); fwnode_handle_put(pdev->dev.fwnode); device_set_node(&pdev->dev, fwnode_handle_get(fwnode)); } @@ -739,11 +750,15 @@ EXPORT_SYMBOL_GPL(platform_device_set_fwnode); * @dev2: device whose OF node to reuse * * Reuses the OF node of another device in this platform device while - * internally keeping track of reference counting. + * internally keeping track of reference counting. This function must not be + * called for a platform device that already has a software node as its primary + * firmware node assigned. */ void platform_device_set_of_node_from_dev(struct platform_device *pdev, const struct device *dev2) { + /* See platform_device_set_fwnode(). */ + WARN_ON(is_software_node(dev_fwnode(&pdev->dev))); device_set_of_node_from_dev(&pdev->dev, dev2); pdev->dev.fwnode = of_fwnode_handle(pdev->dev.of_node); } -- 2.47.3
