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/bgrt.c | 94 +++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 94 insertions(+) create mode 100644 drivers/acpi/bgrt.c (limited to 'drivers/acpi/bgrt.c') diff --git a/drivers/acpi/bgrt.c b/drivers/acpi/bgrt.c new file mode 100644 index 000000000..0fdd581ef --- /dev/null +++ b/drivers/acpi/bgrt.c @@ -0,0 +1,94 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * BGRT boot graphic support + * Authors: Matthew Garrett, Josh Triplett + * Copyright 2012 Red Hat, Inc + * Copyright 2012 Intel Corporation + */ + +#include +#include +#include +#include +#include + +static void *bgrt_image; +static struct kobject *bgrt_kobj; + +#define BGRT_SHOW(_name, _member) \ + static ssize_t _name##_show(struct kobject *kobj, \ + struct kobj_attribute *attr, char *buf) \ + { \ + return sysfs_emit(buf, "%d\n", bgrt_tab._member); \ + } \ + static struct kobj_attribute bgrt_attr_##_name = __ATTR_RO(_name) + +BGRT_SHOW(version, version); +BGRT_SHOW(status, status); +BGRT_SHOW(type, image_type); +BGRT_SHOW(xoffset, image_offset_x); +BGRT_SHOW(yoffset, image_offset_y); + +static __ro_after_init BIN_ATTR_SIMPLE_RO(image); + +static struct attribute *bgrt_attributes[] = { + &bgrt_attr_version.attr, + &bgrt_attr_status.attr, + &bgrt_attr_type.attr, + &bgrt_attr_xoffset.attr, + &bgrt_attr_yoffset.attr, + NULL, +}; + +static const struct bin_attribute *const bgrt_bin_attributes[] = { + &bin_attr_image, + NULL, +}; + +static const struct attribute_group bgrt_attribute_group = { + .attrs = bgrt_attributes, + .bin_attrs = bgrt_bin_attributes, +}; + +int __init acpi_parse_bgrt(struct acpi_table_header *table) +{ + efi_bgrt_init(table); + return 0; +} + +static int __init bgrt_init(void) +{ + int ret; + + if (!bgrt_tab.image_address) + return -ENODEV; + + bgrt_image = memremap(bgrt_tab.image_address, bgrt_image_size, + MEMREMAP_WB); + if (!bgrt_image) { + pr_notice("Ignoring BGRT: failed to map image memory\n"); + return -ENOMEM; + } + + bin_attr_image.private = bgrt_image; + bin_attr_image.size = bgrt_image_size; + + bgrt_kobj = kobject_create_and_add("bgrt", acpi_kobj); + if (!bgrt_kobj) { + ret = -EINVAL; + goto out_memmap; + } + + ret = sysfs_create_group(bgrt_kobj, &bgrt_attribute_group); + if (ret) + goto out_kobject; + + return 0; + +out_kobject: + kobject_put(bgrt_kobj); +out_memmap: + memunmap(bgrt_image); + return ret; +} +device_initcall(bgrt_init); -- cgit v1.3.1