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/pgtable_uffd.h | 83 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 83 insertions(+) create mode 100644 include/asm-generic/pgtable_uffd.h (limited to 'include/asm-generic/pgtable_uffd.h') diff --git a/include/asm-generic/pgtable_uffd.h b/include/asm-generic/pgtable_uffd.h new file mode 100644 index 000000000..30e88fc1d --- /dev/null +++ b/include/asm-generic/pgtable_uffd.h @@ -0,0 +1,83 @@ +#ifndef _ASM_GENERIC_PGTABLE_UFFD_H +#define _ASM_GENERIC_PGTABLE_UFFD_H + +/* + * Some platforms can customize the uffd PTE bit, making it unavailable + * even if the architecture provides the resource. + * Adding this API allows architectures to add their own checks for the + * devices on which the kernel is running. + * Note: When overriding it, please make sure the + * CONFIG_HAVE_ARCH_USERFAULTFD_WP is part of this macro. + */ +#ifndef pgtable_supports_uffd +#define pgtable_supports_uffd() IS_ENABLED(CONFIG_HAVE_ARCH_USERFAULTFD_WP) +#endif + +static inline bool uffd_supports_wp_marker(void) +{ + return pgtable_supports_uffd() && IS_ENABLED(CONFIG_PTE_MARKER_UFFD_WP); +} + +#ifndef CONFIG_HAVE_ARCH_USERFAULTFD_WP +static __always_inline int pte_uffd(pte_t pte) +{ + return 0; +} + +static __always_inline int pmd_uffd(pmd_t pmd) +{ + return 0; +} + +static __always_inline pte_t pte_mkuffd(pte_t pte) +{ + return pte; +} + +static __always_inline pmd_t pmd_mkuffd(pmd_t pmd) +{ + return pmd; +} + +static __always_inline pte_t pte_clear_uffd(pte_t pte) +{ + return pte; +} + +static __always_inline pmd_t pmd_clear_uffd(pmd_t pmd) +{ + return pmd; +} + +static __always_inline pte_t pte_swp_mkuffd(pte_t pte) +{ + return pte; +} + +static __always_inline int pte_swp_uffd(pte_t pte) +{ + return 0; +} + +static __always_inline pte_t pte_swp_clear_uffd(pte_t pte) +{ + return pte; +} + +static inline pmd_t pmd_swp_mkuffd(pmd_t pmd) +{ + return pmd; +} + +static inline int pmd_swp_uffd(pmd_t pmd) +{ + return 0; +} + +static inline pmd_t pmd_swp_clear_uffd(pmd_t pmd) +{ + return pmd; +} +#endif /* CONFIG_HAVE_ARCH_USERFAULTFD_WP */ + +#endif /* _ASM_GENERIC_PGTABLE_UFFD_H */ -- cgit v1.3.1