diff options
Diffstat (limited to 'include/linux/userfaultfd_k.h')
| -rw-r--r-- | include/linux/userfaultfd_k.h | 179 |
1 files changed, 83 insertions, 96 deletions
diff --git a/include/linux/userfaultfd_k.h b/include/linux/userfaultfd_k.h index 75342022d144..d2920f98ab86 100644 --- a/include/linux/userfaultfd_k.h +++ b/include/linux/userfaultfd_k.h @@ -16,13 +16,16 @@ #include <linux/fcntl.h> #include <linux/mm.h> #include <linux/swap.h> -#include <linux/swapops.h> +#include <linux/leafops.h> #include <asm-generic/pgtable_uffd.h> #include <linux/hugetlb_inline.h> /* The set of all possible UFFD-related VM flags. */ #define __VM_UFFD_FLAGS (VM_UFFD_MISSING | VM_UFFD_WP | VM_UFFD_MINOR) +#define __VMA_UFFD_FLAGS mk_vma_flags(VMA_UFFD_MISSING_BIT, VMA_UFFD_WP_BIT, \ + VMA_UFFD_MINOR_BIT) + /* * CAREFUL: Check include/uapi/asm-generic/fcntl.h when defining * new flags, since they might collide with O_* ones. We want @@ -30,11 +33,7 @@ * from userfaultfd, in order to leave a free define-space for * shared O_* flags. */ -#define UFFD_CLOEXEC O_CLOEXEC -#define UFFD_NONBLOCK O_NONBLOCK - #define UFFD_SHARED_FCNTL_FLAGS (O_CLOEXEC | O_NONBLOCK) -#define UFFD_FLAGS_SET (EFD_SHARED_FCNTL_FLAGS) /* * Start with fault_pending_wqh and fault_wqh so they're more likely @@ -84,6 +83,39 @@ struct userfaultfd_ctx { extern vm_fault_t handle_userfault(struct vm_fault *vmf, unsigned long reason); +/* VMA userfaultfd operations */ +struct vm_uffd_ops { + /* Checks if a VMA can support userfaultfd */ + bool (*can_userfault)(struct vm_area_struct *vma, vm_flags_t vm_flags); + /* + * Called to resolve UFFDIO_CONTINUE request. + * Should return the folio found at pgoff in the VMA's pagecache if it + * exists or ERR_PTR otherwise. + * The returned folio is locked and with reference held. + */ + struct folio *(*get_folio_noalloc)(struct inode *inode, pgoff_t pgoff); + /* + * Called during resolution of UFFDIO_COPY request. + * Should allocate and return a folio or NULL if allocation fails. + */ + struct folio *(*alloc_folio)(struct vm_area_struct *vma, + unsigned long addr); + /* + * Called during resolution of UFFDIO_COPY request. + * Should only be called with a folio returned by alloc_folio() above. + * The folio will be set to locked. + * Returns 0 on success, error code on failure. + */ + int (*filemap_add)(struct folio *folio, struct vm_area_struct *vma, + unsigned long addr); + /* + * Called during resolution of UFFDIO_COPY request on the error + * handling path. + * Should revert the operation of ->filemap_add(). + */ + void (*filemap_remove)(struct folio *folio, struct vm_area_struct *vma); +}; + /* A combined operation mode + behavior flags. */ typedef unsigned int __bitwise uffd_flags_t; @@ -115,11 +147,6 @@ static inline uffd_flags_t uffd_flags_set_mode(uffd_flags_t flags, enum mfill_at /* Flags controlling behavior. These behavior changes are mode-independent. */ #define MFILL_ATOMIC_WP MFILL_ATOMIC_FLAG(0) -extern int mfill_atomic_install_pte(pmd_t *dst_pmd, - struct vm_area_struct *dst_vma, - unsigned long dst_addr, struct page *page, - bool newly_allocated, uffd_flags_t flags); - extern ssize_t mfill_atomic_copy(struct userfaultfd_ctx *ctx, unsigned long dst_start, unsigned long src_start, unsigned long len, uffd_flags_t flags); @@ -212,40 +239,8 @@ static inline bool userfaultfd_armed(struct vm_area_struct *vma) return vma->vm_flags & __VM_UFFD_FLAGS; } -static inline bool vma_can_userfault(struct vm_area_struct *vma, - unsigned long vm_flags, - bool wp_async) -{ - vm_flags &= __VM_UFFD_FLAGS; - - if (vm_flags & VM_DROPPABLE) - return false; - - if ((vm_flags & VM_UFFD_MINOR) && - (!is_vm_hugetlb_page(vma) && !vma_is_shmem(vma))) - return false; - - /* - * If wp async enabled, and WP is the only mode enabled, allow any - * memory type. - */ - 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)) - return false; -#endif - - /* By default, allow any of anon|shmem|hugetlb */ - return vma_is_anonymous(vma) || is_vm_hugetlb_page(vma) || - vma_is_shmem(vma); -} +bool vma_can_userfault(struct vm_area_struct *vma, vm_flags_t vm_flags, + bool wp_async); static inline bool vma_has_uffd_without_event_remap(struct vm_area_struct *vma) { @@ -263,6 +258,7 @@ extern void mremap_userfaultfd_prep(struct vm_area_struct *, extern void mremap_userfaultfd_complete(struct vm_userfaultfd_ctx *, unsigned long from, unsigned long to, unsigned long len); +void mremap_userfaultfd_fail(struct vm_userfaultfd_ctx *); extern bool userfaultfd_remove(struct vm_area_struct *vma, unsigned long start, @@ -285,7 +281,7 @@ struct vm_area_struct *userfaultfd_clear_vma(struct vma_iterator *vmi, int userfaultfd_register_range(struct userfaultfd_ctx *ctx, struct vm_area_struct *vma, - unsigned long vm_flags, + vm_flags_t vm_flags, unsigned long start, unsigned long end, bool wp_async); @@ -294,6 +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 */ @@ -375,6 +408,10 @@ static inline void mremap_userfaultfd_complete(struct vm_userfaultfd_ctx *ctx, { } +static inline void mremap_userfaultfd_fail(struct vm_userfaultfd_ctx *ctx) +{ +} + static inline bool userfaultfd_remove(struct vm_area_struct *vma, unsigned long start, unsigned long end) @@ -414,49 +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); -} - -static inline bool pte_marker_entry_uffd_wp(swp_entry_t entry) -{ -#ifdef CONFIG_PTE_MARKER_UFFD_WP - return is_pte_marker_entry(entry) && - (pte_marker_get(entry) & PTE_MARKER_UFFD_WP); -#else - return false; -#endif -} - -static inline bool pte_marker_uffd_wp(pte_t pte) -{ -#ifdef CONFIG_PTE_MARKER_UFFD_WP - swp_entry_t entry; - - if (!is_swap_pte(pte)) - return false; - - entry = pte_to_swp_entry(pte); - - return pte_marker_entry_uffd_wp(entry); -#else return false; -#endif } /* @@ -465,17 +462,7 @@ static inline bool pte_marker_uffd_wp(pte_t pte) */ static inline bool pte_swp_uffd_wp_any(pte_t pte) { -#ifdef CONFIG_PTE_MARKER_UFFD_WP - if (!is_swap_pte(pte)) - return false; - - if (pte_swp_uffd_wp(pte)) - return true; - - if (pte_marker_uffd_wp(pte)) - return true; -#endif return false; } - +#endif /* CONFIG_USERFAULTFD */ #endif /* _LINUX_USERFAULTFD_K_H */ |