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 --- include/asm-generic/fixmap.h | 101 +++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 101 insertions(+) create mode 100644 include/asm-generic/fixmap.h (limited to 'include/asm-generic/fixmap.h') diff --git a/include/asm-generic/fixmap.h b/include/asm-generic/fixmap.h new file mode 100644 index 000000000..3ff832ebc --- /dev/null +++ b/include/asm-generic/fixmap.h @@ -0,0 +1,101 @@ +/* + * fixmap.h: compile-time virtual memory allocation + * + * This file is subject to the terms and conditions of the GNU General Public + * License. See the file "COPYING" in the main directory of this archive + * for more details. + * + * Copyright (C) 1998 Ingo Molnar + * + * Support of BIGMEM added by Gerhard Wichert, Siemens AG, July 1999 + * x86_32 and x86_64 integration by Gustavo F. Padovan, February 2009 + * Break out common bits to asm-generic by Mark Salter, November 2013 + */ + +#ifndef __ASM_GENERIC_FIXMAP_H +#define __ASM_GENERIC_FIXMAP_H + +#include +#include + +#define __fix_to_virt(x) (FIXADDR_TOP - ((x) << PAGE_SHIFT)) +#define __virt_to_fix(x) ((FIXADDR_TOP - ((x)&PAGE_MASK)) >> PAGE_SHIFT) + +#ifndef __ASSEMBLER__ +/* + * 'index to address' translation. If anyone tries to use the idx + * directly without translation, we catch the bug with a NULL-deference + * kernel oops. Illegal ranges of incoming indices are caught too. + */ +static __always_inline unsigned long fix_to_virt(const unsigned int idx) +{ + BUILD_BUG_ON(idx >= __end_of_fixed_addresses); + return __fix_to_virt(idx); +} + +static inline unsigned long virt_to_fix(const unsigned long vaddr) +{ + BUG_ON(vaddr >= FIXADDR_TOP || vaddr < FIXADDR_START); + return __virt_to_fix(vaddr); +} + +/* + * Provide some reasonable defaults for page flags. + * Not all architectures use all of these different types and some + * architectures use different names. + */ +#ifndef FIXMAP_PAGE_NORMAL +#define FIXMAP_PAGE_NORMAL PAGE_KERNEL +#endif +#if !defined(FIXMAP_PAGE_RO) && defined(PAGE_KERNEL_RO) +#define FIXMAP_PAGE_RO PAGE_KERNEL_RO +#endif +#ifndef FIXMAP_PAGE_NOCACHE +#define FIXMAP_PAGE_NOCACHE PAGE_KERNEL_NOCACHE +#endif +#ifndef FIXMAP_PAGE_IO +#define FIXMAP_PAGE_IO PAGE_KERNEL_IO +#endif +#ifndef FIXMAP_PAGE_CLEAR +#define FIXMAP_PAGE_CLEAR __pgprot(0) +#endif + +#ifndef set_fixmap +#define set_fixmap(idx, phys) \ + __set_fixmap(idx, phys, FIXMAP_PAGE_NORMAL) +#endif + +#ifndef clear_fixmap +#define clear_fixmap(idx) \ + __set_fixmap(idx, 0, FIXMAP_PAGE_CLEAR) +#endif + +/* Return a pointer with offset calculated */ +#define __set_fixmap_offset(idx, phys, flags) \ +({ \ + unsigned long ________addr; \ + __set_fixmap(idx, phys, flags); \ + ________addr = fix_to_virt(idx) + ((phys) & (PAGE_SIZE - 1)); \ + ________addr; \ +}) + +#define set_fixmap_offset(idx, phys) \ + __set_fixmap_offset(idx, phys, FIXMAP_PAGE_NORMAL) + +/* + * Some hardware wants to get fixmapped without caching. + */ +#define set_fixmap_nocache(idx, phys) \ + __set_fixmap(idx, phys, FIXMAP_PAGE_NOCACHE) + +#define set_fixmap_offset_nocache(idx, phys) \ + __set_fixmap_offset(idx, phys, FIXMAP_PAGE_NOCACHE) + +/* + * Some fixmaps are for IO + */ +#define set_fixmap_io(idx, phys) \ + __set_fixmap(idx, phys, FIXMAP_PAGE_IO) + +#endif /* __ASSEMBLER__ */ +#endif /* __ASM_GENERIC_FIXMAP_H */ -- cgit v1.3.1