1 /* SPDX-License-Identifier: GPL-2.0 */
3 * include/linux/userfaultfd_k.h
5 * Copyright (C) 2015 Red Hat, Inc.
9 #ifndef _LINUX_USERFAULTFD_K_H
10 #define _LINUX_USERFAULTFD_K_H
12 #ifdef CONFIG_USERFAULTFD
14 #include <linux/userfaultfd.h> /* linux/include/uapi/linux/userfaultfd.h */
16 #include <linux/fcntl.h>
19 * CAREFUL: Check include/uapi/asm-generic/fcntl.h when defining
20 * new flags, since they might collide with O_* ones. We want
21 * to re-use O_* flags that couldn't possibly have a meaning
22 * from userfaultfd, in order to leave a free define-space for
25 #define UFFD_CLOEXEC O_CLOEXEC
26 #define UFFD_NONBLOCK O_NONBLOCK
28 #define UFFD_SHARED_FCNTL_FLAGS (O_CLOEXEC | O_NONBLOCK)
29 #define UFFD_FLAGS_SET (EFD_SHARED_FCNTL_FLAGS)
31 extern int handle_userfault(struct vm_fault *vmf, unsigned long reason);
33 extern ssize_t mcopy_atomic(struct mm_struct *dst_mm, unsigned long dst_start,
34 unsigned long src_start, unsigned long len,
36 extern ssize_t mfill_zeropage(struct mm_struct *dst_mm,
37 unsigned long dst_start,
42 static inline bool is_mergeable_vm_userfaultfd_ctx(struct vm_area_struct *vma,
43 struct vm_userfaultfd_ctx vm_ctx)
45 return vma->vm_userfaultfd_ctx.ctx == vm_ctx.ctx;
48 static inline bool userfaultfd_missing(struct vm_area_struct *vma)
50 return vma->vm_flags & VM_UFFD_MISSING;
53 static inline bool userfaultfd_armed(struct vm_area_struct *vma)
55 return vma->vm_flags & (VM_UFFD_MISSING | VM_UFFD_WP);
58 extern int dup_userfaultfd(struct vm_area_struct *, struct list_head *);
59 extern void dup_userfaultfd_complete(struct list_head *);
61 extern void mremap_userfaultfd_prep(struct vm_area_struct *,
62 struct vm_userfaultfd_ctx *);
63 extern void mremap_userfaultfd_complete(struct vm_userfaultfd_ctx *,
64 unsigned long from, unsigned long to,
67 extern bool userfaultfd_remove(struct vm_area_struct *vma,
71 extern int userfaultfd_unmap_prep(struct vm_area_struct *vma,
72 unsigned long start, unsigned long end,
73 struct list_head *uf);
74 extern void userfaultfd_unmap_complete(struct mm_struct *mm,
75 struct list_head *uf);
77 #else /* CONFIG_USERFAULTFD */
80 static inline int handle_userfault(struct vm_fault *vmf, unsigned long reason)
82 return VM_FAULT_SIGBUS;
85 static inline bool is_mergeable_vm_userfaultfd_ctx(struct vm_area_struct *vma,
86 struct vm_userfaultfd_ctx vm_ctx)
91 static inline bool userfaultfd_missing(struct vm_area_struct *vma)
96 static inline bool userfaultfd_armed(struct vm_area_struct *vma)
101 static inline int dup_userfaultfd(struct vm_area_struct *vma,
107 static inline void dup_userfaultfd_complete(struct list_head *l)
111 static inline void mremap_userfaultfd_prep(struct vm_area_struct *vma,
112 struct vm_userfaultfd_ctx *ctx)
116 static inline void mremap_userfaultfd_complete(struct vm_userfaultfd_ctx *ctx,
123 static inline bool userfaultfd_remove(struct vm_area_struct *vma,
130 static inline int userfaultfd_unmap_prep(struct vm_area_struct *vma,
131 unsigned long start, unsigned long end,
132 struct list_head *uf)
137 static inline void userfaultfd_unmap_complete(struct mm_struct *mm,
138 struct list_head *uf)
142 #endif /* CONFIG_USERFAULTFD */
144 #endif /* _LINUX_USERFAULTFD_K_H */