diff options
| -rw-r--r-- | fs/userfaultfd.c | 22 | ||||
| -rw-r--r-- | include/asm-generic/pgtable_uffd.h | 17 | ||||
| -rw-r--r-- | include/linux/mm_inline.h | 8 | ||||
| -rw-r--r-- | include/linux/userfaultfd_k.h | 69 | ||||
| -rw-r--r-- | mm/memory.c | 6 |
5 files changed, 78 insertions, 44 deletions
diff --git a/fs/userfaultfd.c b/fs/userfaultfd.c index 3f539aabc3b3..5a0d19dec7ba 100644 --- a/fs/userfaultfd.c +++ b/fs/userfaultfd.c @@ -1289,9 +1289,9 @@ static int userfaultfd_register(struct userfaultfd_ctx *ctx, if (uffdio_register.mode & UFFDIO_REGISTER_MODE_MISSING) vm_flags |= VM_UFFD_MISSING; if (uffdio_register.mode & UFFDIO_REGISTER_MODE_WP) { -#ifndef CONFIG_HAVE_ARCH_USERFAULTFD_WP - goto out; -#endif + if (!pgtable_supports_uffd_wp()) + goto out; + vm_flags |= VM_UFFD_WP; } if (uffdio_register.mode & UFFDIO_REGISTER_MODE_MINOR) { @@ -1999,14 +1999,14 @@ static int userfaultfd_api(struct userfaultfd_ctx *ctx, uffdio_api.features &= ~(UFFD_FEATURE_MINOR_HUGETLBFS | UFFD_FEATURE_MINOR_SHMEM); #endif -#ifndef CONFIG_HAVE_ARCH_USERFAULTFD_WP - uffdio_api.features &= ~UFFD_FEATURE_PAGEFAULT_FLAG_WP; -#endif -#ifndef CONFIG_PTE_MARKER_UFFD_WP - uffdio_api.features &= ~UFFD_FEATURE_WP_HUGETLBFS_SHMEM; - uffdio_api.features &= ~UFFD_FEATURE_WP_UNPOPULATED; - uffdio_api.features &= ~UFFD_FEATURE_WP_ASYNC; -#endif + if (!pgtable_supports_uffd_wp()) + uffdio_api.features &= ~UFFD_FEATURE_PAGEFAULT_FLAG_WP; + + if (!uffd_supports_wp_marker()) { + uffdio_api.features &= ~UFFD_FEATURE_WP_HUGETLBFS_SHMEM; + uffdio_api.features &= ~UFFD_FEATURE_WP_UNPOPULATED; + uffdio_api.features &= ~UFFD_FEATURE_WP_ASYNC; + } ret = -EINVAL; if (features & ~uffdio_api.features) diff --git a/include/asm-generic/pgtable_uffd.h b/include/asm-generic/pgtable_uffd.h index 828966d4c281..0d85791efdf7 100644 --- a/include/asm-generic/pgtable_uffd.h +++ b/include/asm-generic/pgtable_uffd.h @@ -1,6 +1,23 @@ #ifndef _ASM_GENERIC_PGTABLE_UFFD_H #define _ASM_GENERIC_PGTABLE_UFFD_H +/* + * Some platforms can customize the uffd-wp 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_wp +#define pgtable_supports_uffd_wp() IS_ENABLED(CONFIG_HAVE_ARCH_USERFAULTFD_WP) +#endif + +static inline bool uffd_supports_wp_marker(void) +{ + return pgtable_supports_uffd_wp() && IS_ENABLED(CONFIG_PTE_MARKER_UFFD_WP); +} + #ifndef CONFIG_HAVE_ARCH_USERFAULTFD_WP static __always_inline int pte_uffd_wp(pte_t pte) { diff --git a/include/linux/mm_inline.h b/include/linux/mm_inline.h index b58f34c4fe92..fa2d6ba811b5 100644 --- a/include/linux/mm_inline.h +++ b/include/linux/mm_inline.h @@ -553,7 +553,6 @@ static inline pte_marker copy_pte_marker( return dstm; } -#endif /* * If this pte is wr-protected by uffd-wp in any form, arm the special pte to @@ -571,9 +570,11 @@ static inline bool pte_install_uffd_wp_if_needed(struct vm_area_struct *vma, unsigned long addr, pte_t *pte, pte_t pteval) { -#ifdef CONFIG_PTE_MARKER_UFFD_WP bool arm_uffd_pte = false; + if (!uffd_supports_wp_marker()) + return false; + /* The current status of the pte should be "cleared" before calling */ WARN_ON_ONCE(!pte_none(ptep_get(pte))); @@ -602,7 +603,7 @@ pte_install_uffd_wp_if_needed(struct vm_area_struct *vma, unsigned long addr, make_pte_marker(PTE_MARKER_UFFD_WP)); return true; } -#endif + return false; } @@ -616,6 +617,7 @@ static inline bool vma_has_recency(const struct vm_area_struct *vma) return true; } +#endif /** * num_pages_contiguous() - determine the number of contiguous pages diff --git a/include/linux/userfaultfd_k.h b/include/linux/userfaultfd_k.h index 96b089dff4ef..fd5f42765497 100644 --- a/include/linux/userfaultfd_k.h +++ b/include/linux/userfaultfd_k.h @@ -228,15 +228,14 @@ static inline bool vma_can_userfault(struct vm_area_struct *vma, if (wp_async && (vm_flags == VM_UFFD_WP)) return true; -#ifndef CONFIG_PTE_MARKER_UFFD_WP /* * If user requested uffd-wp but not enabled pte markers for * uffd-wp, then shmem & hugetlbfs are not supported but only * anonymous. */ - if ((vm_flags & VM_UFFD_WP) && !vma_is_anonymous(vma)) + if (!uffd_supports_wp_marker() && (vm_flags & VM_UFFD_WP) && + !vma_is_anonymous(vma)) return false; -#endif /* By default, allow any of anon|shmem|hugetlb */ return vma_is_anonymous(vma) || is_vm_hugetlb_page(vma) || @@ -291,6 +290,43 @@ void userfaultfd_release_new(struct userfaultfd_ctx *ctx); void userfaultfd_release_all(struct mm_struct *mm, struct userfaultfd_ctx *ctx); +static inline bool userfaultfd_wp_use_markers(struct vm_area_struct *vma) +{ + /* Only wr-protect mode uses pte markers */ + if (!userfaultfd_wp(vma)) + return false; + + /* File-based uffd-wp always need markers */ + if (!vma_is_anonymous(vma)) + return true; + + /* + * Anonymous uffd-wp only needs the markers if WP_UNPOPULATED + * enabled (to apply markers on zero pages). + */ + return userfaultfd_wp_unpopulated(vma); +} + +/* + * Returns true if this is a swap pte and was uffd-wp wr-protected in either + * forms (pte marker or a normal swap pte), false otherwise. + */ +static inline bool pte_swp_uffd_wp_any(pte_t pte) +{ + if (!uffd_supports_wp_marker()) + return false; + + if (pte_present(pte)) + return false; + + if (pte_swp_uffd_wp(pte)) + return true; + + if (pte_is_uffd_wp_marker(pte)) + return true; + + return false; +} #else /* CONFIG_USERFAULTFD */ /* mm helpers */ @@ -415,23 +451,9 @@ static inline bool vma_has_uffd_without_event_remap(struct vm_area_struct *vma) return false; } -#endif /* CONFIG_USERFAULTFD */ - static inline bool userfaultfd_wp_use_markers(struct vm_area_struct *vma) { - /* Only wr-protect mode uses pte markers */ - if (!userfaultfd_wp(vma)) - return false; - - /* File-based uffd-wp always need markers */ - if (!vma_is_anonymous(vma)) - return true; - - /* - * Anonymous uffd-wp only needs the markers if WP_UNPOPULATED - * enabled (to apply markers on zero pages). - */ - return userfaultfd_wp_unpopulated(vma); + return false; } /* @@ -440,16 +462,7 @@ static inline bool userfaultfd_wp_use_markers(struct vm_area_struct *vma) */ static inline bool pte_swp_uffd_wp_any(pte_t pte) { -#ifdef CONFIG_PTE_MARKER_UFFD_WP - if (pte_present(pte)) - return false; - if (pte_swp_uffd_wp(pte)) - return true; - - if (pte_is_uffd_wp_marker(pte)) - return true; -#endif return false; } - +#endif /* CONFIG_USERFAULTFD */ #endif /* _LINUX_USERFAULTFD_K_H */ diff --git a/mm/memory.c b/mm/memory.c index 50b93b45b174..6675e87eb7dd 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -1590,7 +1590,9 @@ zap_install_uffd_wp_if_needed(struct vm_area_struct *vma, { bool was_installed = false; -#ifdef CONFIG_PTE_MARKER_UFFD_WP + if (!uffd_supports_wp_marker()) + return false; + /* Zap on anonymous always means dropping everything */ if (vma_is_anonymous(vma)) return false; @@ -1607,7 +1609,7 @@ zap_install_uffd_wp_if_needed(struct vm_area_struct *vma, pte++; addr += PAGE_SIZE; } -#endif + return was_installed; } |