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 sysctl_unprivileged_userfaultfd;
33 extern vm_fault_t handle_userfault(struct vm_fault *vmf, unsigned long reason);
35 extern ssize_t mcopy_atomic(struct mm_struct *dst_mm, unsigned long dst_start,
36 unsigned long src_start, unsigned long len,
38 extern ssize_t mfill_zeropage(struct mm_struct *dst_mm,
39 unsigned long dst_start,
44 static inline bool is_mergeable_vm_userfaultfd_ctx(struct vm_area_struct *vma,
45 struct vm_userfaultfd_ctx vm_ctx)
47 return vma->vm_userfaultfd_ctx.ctx == vm_ctx.ctx;
50 static inline bool userfaultfd_missing(struct vm_area_struct *vma)
52 return vma->vm_flags & VM_UFFD_MISSING;
55 static inline bool userfaultfd_armed(struct vm_area_struct *vma)
57 return vma->vm_flags & (VM_UFFD_MISSING | VM_UFFD_WP);
60 extern int dup_userfaultfd(struct vm_area_struct *, struct list_head *);
61 extern void dup_userfaultfd_complete(struct list_head *);
63 extern void mremap_userfaultfd_prep(struct vm_area_struct *,
64 struct vm_userfaultfd_ctx *);
65 extern void mremap_userfaultfd_complete(struct vm_userfaultfd_ctx *,
66 unsigned long from, unsigned long to,
69 extern bool userfaultfd_remove(struct vm_area_struct *vma,
73 extern int userfaultfd_unmap_prep(struct vm_area_struct *vma,
74 unsigned long start, unsigned long end,
75 struct list_head *uf);
76 extern void userfaultfd_unmap_complete(struct mm_struct *mm,
77 struct list_head *uf);
79 #else /* CONFIG_USERFAULTFD */
82 static inline vm_fault_t handle_userfault(struct vm_fault *vmf,
85 return VM_FAULT_SIGBUS;
88 static inline bool is_mergeable_vm_userfaultfd_ctx(struct vm_area_struct *vma,
89 struct vm_userfaultfd_ctx vm_ctx)
94 static inline bool userfaultfd_missing(struct vm_area_struct *vma)
99 static inline bool userfaultfd_armed(struct vm_area_struct *vma)
104 static inline int dup_userfaultfd(struct vm_area_struct *vma,
110 static inline void dup_userfaultfd_complete(struct list_head *l)
114 static inline void mremap_userfaultfd_prep(struct vm_area_struct *vma,
115 struct vm_userfaultfd_ctx *ctx)
119 static inline void mremap_userfaultfd_complete(struct vm_userfaultfd_ctx *ctx,
126 static inline bool userfaultfd_remove(struct vm_area_struct *vma,
133 static inline int userfaultfd_unmap_prep(struct vm_area_struct *vma,
134 unsigned long start, unsigned long end,
135 struct list_head *uf)
140 static inline void userfaultfd_unmap_complete(struct mm_struct *mm,
141 struct list_head *uf)
145 #endif /* CONFIG_USERFAULTFD */
147 #endif /* _LINUX_USERFAULTFD_K_H */