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/acpi/container.c | 117 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 117 insertions(+) create mode 100644 drivers/acpi/container.c (limited to 'drivers/acpi/container.c') diff --git a/drivers/acpi/container.c b/drivers/acpi/container.c new file mode 100644 index 000000000..f138a4335 --- /dev/null +++ b/drivers/acpi/container.c @@ -0,0 +1,117 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * container.c - ACPI Generic Container Driver + * + * Copyright (C) 2004 Anil S Keshavamurthy (anil.s.keshavamurthy@intel.com) + * Copyright (C) 2004 Keiichiro Tokunaga (tokunaga.keiich@jp.fujitsu.com) + * Copyright (C) 2004 Motoyuki Ito (motoyuki@soft.fujitsu.com) + * Copyright (C) 2004 FUJITSU LIMITED + * Copyright (C) 2004, 2013 Intel Corp. + * Author: Rafael J. Wysocki + */ +#include +#include + +#include "internal.h" + +static const struct acpi_device_id container_device_ids[] = { + {"ACPI0004", 0}, + {"PNP0A05", 0}, + {"PNP0A06", 0}, + {"", 0}, +}; + +#ifdef CONFIG_ACPI_CONTAINER + +static int check_offline(struct acpi_device *adev, void *not_used) +{ + if (acpi_scan_is_offline(adev, false)) + return 0; + + return -EBUSY; +} + +static int acpi_container_offline(struct container_dev *cdev) +{ + /* Check all of the dependent devices' physical companions. */ + return acpi_dev_for_each_child(ACPI_COMPANION(&cdev->dev), check_offline, NULL); +} + +static void acpi_container_release(struct device *dev) +{ + kfree(to_container_dev(dev)); +} + +static int container_device_attach(struct acpi_device *adev, + const struct acpi_device_id *not_used) +{ + struct container_dev *cdev; + struct device *dev; + int ret; + + if (adev->flags.is_dock_station) + return 0; + + cdev = kzalloc_obj(*cdev); + if (!cdev) + return -ENOMEM; + + cdev->offline = acpi_container_offline; + dev = &cdev->dev; + dev->bus = &container_subsys; + dev_set_name(dev, "%s", dev_name(&adev->dev)); + ACPI_COMPANION_SET(dev, adev); + dev->release = acpi_container_release; + ret = device_register(dev); + if (ret) { + put_device(dev); + return ret; + } + adev->driver_data = dev; + return 1; +} + +static void container_device_detach(struct acpi_device *adev) +{ + struct device *dev = acpi_driver_data(adev); + + adev->driver_data = NULL; + if (dev) + device_unregister(dev); +} + +static void container_device_online(struct acpi_device *adev) +{ + struct device *dev = acpi_driver_data(adev); + + kobject_uevent(&dev->kobj, KOBJ_ONLINE); +} + +static struct acpi_scan_handler container_handler = { + .ids = container_device_ids, + .attach = container_device_attach, + .detach = container_device_detach, + .hotplug = { + .enabled = true, + .demand_offline = true, + .notify_online = container_device_online, + }, +}; + +void __init acpi_container_init(void) +{ + acpi_scan_add_handler(&container_handler); +} + +#else + +static struct acpi_scan_handler container_handler = { + .ids = container_device_ids, +}; + +void __init acpi_container_init(void) +{ + acpi_scan_add_handler_with_hotplug(&container_handler, "container"); +} + +#endif /* CONFIG_ACPI_CONTAINER */ -- cgit v1.3.1