From 27600805e62f800bacf990354632eae4e487d34c Mon Sep 17 00:00:00 2001 From: Yazen Ghannam Date: Thu, 3 Sep 2026 10:43:25 -0500 Subject: x86/amd_node: Fix PCI device reference counting in amd_smn_init() The local "root" pointer is a temporary variable used during the device search. Therefore, refcount related to the search iterators should be cleaned up after the search is complete. Use the __free() cleanup macro to ensure the refcount is decremented when the temporary pointer goes out of scope. Additionally, increment the refcount when caching a root pointer. This ensures the in-use refcount is separate from the temporary search refcounting. Finally, drop the redundant "root = NULL" before the second search loop. The pci_get_class() iterator always decrements the refcount of its "from" argument, so the first loop can only fall through with "root" already NULL. Fixes: 0a4b61d9c2e4 ("x86/amd_node: Fix AMD root device caching") Closes: https://sashiko.dev/#/patchset/20260806160159.230453-1-jason.andryuk%40amd.com Reported-by: Sashiko Assisted-by: LLM Signed-off-by: Yazen Ghannam Signed-off-by: Borislav Petkov (AMD) Reviewed-by: Mario Limonciello (AMD) Cc: Link: https://patch.msgid.link/20260903154325.74343-1-yazen.ghannam@amd.com --- drivers/comedi/comedi_usb.c | 139 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 139 insertions(+) create mode 100644 drivers/comedi/comedi_usb.c (limited to 'drivers/comedi/comedi_usb.c') diff --git a/drivers/comedi/comedi_usb.c b/drivers/comedi/comedi_usb.c new file mode 100644 index 000000000..75d65171c --- /dev/null +++ b/drivers/comedi/comedi_usb.c @@ -0,0 +1,139 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * comedi_usb.c + * Comedi USB driver specific functions. + * + * COMEDI - Linux Control and Measurement Device Interface + * Copyright (C) 1997-2000 David A. Schleef + */ + +#include +#include + +/** + * comedi_to_usb_interface() - Return USB interface attached to COMEDI device + * @dev: COMEDI device. + * + * Assuming @dev->hw_dev is non-%NULL, it is assumed to be pointing to a + * a &struct device embedded in a &struct usb_interface. + * + * Return: Attached USB interface if @dev->hw_dev is non-%NULL. + * Return %NULL if @dev->hw_dev is %NULL. + */ +struct usb_interface *comedi_to_usb_interface(struct comedi_device *dev) +{ + return dev->hw_dev ? to_usb_interface(dev->hw_dev) : NULL; +} +EXPORT_SYMBOL_GPL(comedi_to_usb_interface); + +/** + * comedi_to_usb_dev() - Return USB device attached to COMEDI device + * @dev: COMEDI device. + * + * Assuming @dev->hw_dev is non-%NULL, it is assumed to be pointing to a + * a &struct device embedded in a &struct usb_interface. + * + * Return: USB device to which the USB interface belongs if @dev->hw_dev is + * non-%NULL. Return %NULL if @dev->hw_dev is %NULL. + */ +struct usb_device *comedi_to_usb_dev(struct comedi_device *dev) +{ + struct usb_interface *intf = comedi_to_usb_interface(dev); + + return intf ? interface_to_usbdev(intf) : NULL; +} +EXPORT_SYMBOL_GPL(comedi_to_usb_dev); + +/** + * comedi_usb_auto_config() - Configure/probe a USB COMEDI driver + * @intf: USB interface. + * @driver: Registered COMEDI driver. + * @context: Driver specific data, passed to comedi_auto_config(). + * + * Typically called from the usb_driver (*probe) function. Auto-configure a + * COMEDI device, using a pointer to the &struct device embedded in *@intf as + * the hardware device. The @context value gets passed through to @driver's + * "auto_attach" handler. The "auto_attach" handler may call + * comedi_to_usb_interface() on the passed in COMEDI device to recover @intf. + * + * Return: The result of calling comedi_auto_config() (%0 on success, or + * a negative error number on failure). + */ +int comedi_usb_auto_config(struct usb_interface *intf, + struct comedi_driver *driver, + unsigned long context) +{ + return comedi_auto_config(&intf->dev, driver, context); +} +EXPORT_SYMBOL_GPL(comedi_usb_auto_config); + +/** + * comedi_usb_auto_unconfig() - Unconfigure/disconnect a USB COMEDI device + * @intf: USB interface. + * + * Typically called from the usb_driver (*disconnect) function. + * Auto-unconfigure a COMEDI device attached to this USB interface, using a + * pointer to the &struct device embedded in *@intf as the hardware device. + * The COMEDI driver's "detach" handler will be called during unconfiguration + * of the COMEDI device. + * + * Note that the COMEDI device may have already been unconfigured using the + * %COMEDI_DEVCONFIG ioctl, in which case this attempt to unconfigure it + * again should be ignored. + */ +void comedi_usb_auto_unconfig(struct usb_interface *intf) +{ + comedi_auto_unconfig(&intf->dev); +} +EXPORT_SYMBOL_GPL(comedi_usb_auto_unconfig); + +/** + * comedi_usb_driver_register() - Register a USB COMEDI driver + * @comedi_driver: COMEDI driver to be registered. + * @usb_driver: USB driver to be registered. + * + * This function is called from the module_init() of USB COMEDI driver modules + * to register the COMEDI driver and the USB driver. Do not call it directly, + * use the module_comedi_usb_driver() helper macro instead. + * + * Return: %0 on success, or a negative error number on failure. + */ +int comedi_usb_driver_register(struct comedi_driver *comedi_driver, + struct usb_driver *usb_driver) +{ + int ret; + + ret = comedi_driver_register(comedi_driver); + if (ret < 0) + return ret; + + ret = usb_register(usb_driver); + if (ret < 0) { + comedi_driver_unregister(comedi_driver); + return ret; + } + + return 0; +} +EXPORT_SYMBOL_GPL(comedi_usb_driver_register); + +/** + * comedi_usb_driver_unregister() - Unregister a USB COMEDI driver + * @comedi_driver: COMEDI driver to be registered. + * @usb_driver: USB driver to be registered. + * + * This function is called from the module_exit() of USB COMEDI driver modules + * to unregister the USB driver and the COMEDI driver. Do not call it + * directly, use the module_comedi_usb_driver() helper macro instead. + */ +void comedi_usb_driver_unregister(struct comedi_driver *comedi_driver, + struct usb_driver *usb_driver) +{ + usb_deregister(usb_driver); + comedi_driver_unregister(comedi_driver); +} +EXPORT_SYMBOL_GPL(comedi_usb_driver_unregister); + +MODULE_AUTHOR("https://www.comedi.org"); +MODULE_DESCRIPTION("Comedi USB interface module"); +MODULE_LICENSE("GPL"); -- cgit v1.3.1