Linux kernel mirror (for testing)
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linux
1/*
2 * include/linux/userfaultfd_k.h
3 *
4 * Copyright (C) 2015 Red Hat, Inc.
5 *
6 */
7
8#ifndef _LINUX_USERFAULTFD_K_H
9#define _LINUX_USERFAULTFD_K_H
10
11#ifdef CONFIG_USERFAULTFD
12
13#include <linux/userfaultfd.h> /* linux/include/uapi/linux/userfaultfd.h */
14
15#include <linux/fcntl.h>
16
17/*
18 * CAREFUL: Check include/uapi/asm-generic/fcntl.h when defining
19 * new flags, since they might collide with O_* ones. We want
20 * to re-use O_* flags that couldn't possibly have a meaning
21 * from userfaultfd, in order to leave a free define-space for
22 * shared O_* flags.
23 */
24#define UFFD_CLOEXEC O_CLOEXEC
25#define UFFD_NONBLOCK O_NONBLOCK
26
27#define UFFD_SHARED_FCNTL_FLAGS (O_CLOEXEC | O_NONBLOCK)
28#define UFFD_FLAGS_SET (EFD_SHARED_FCNTL_FLAGS)
29
30extern int handle_userfault(struct vm_fault *vmf, unsigned long reason);
31
32extern ssize_t mcopy_atomic(struct mm_struct *dst_mm, unsigned long dst_start,
33 unsigned long src_start, unsigned long len);
34extern ssize_t mfill_zeropage(struct mm_struct *dst_mm,
35 unsigned long dst_start,
36 unsigned long len);
37
38/* mm helpers */
39static inline bool is_mergeable_vm_userfaultfd_ctx(struct vm_area_struct *vma,
40 struct vm_userfaultfd_ctx vm_ctx)
41{
42 return vma->vm_userfaultfd_ctx.ctx == vm_ctx.ctx;
43}
44
45static inline bool userfaultfd_missing(struct vm_area_struct *vma)
46{
47 return vma->vm_flags & VM_UFFD_MISSING;
48}
49
50static inline bool userfaultfd_armed(struct vm_area_struct *vma)
51{
52 return vma->vm_flags & (VM_UFFD_MISSING | VM_UFFD_WP);
53}
54
55extern int dup_userfaultfd(struct vm_area_struct *, struct list_head *);
56extern void dup_userfaultfd_complete(struct list_head *);
57
58extern void mremap_userfaultfd_prep(struct vm_area_struct *,
59 struct vm_userfaultfd_ctx *);
60extern void mremap_userfaultfd_complete(struct vm_userfaultfd_ctx *,
61 unsigned long from, unsigned long to,
62 unsigned long len);
63
64extern bool userfaultfd_remove(struct vm_area_struct *vma,
65 unsigned long start,
66 unsigned long end);
67
68extern int userfaultfd_unmap_prep(struct vm_area_struct *vma,
69 unsigned long start, unsigned long end,
70 struct list_head *uf);
71extern void userfaultfd_unmap_complete(struct mm_struct *mm,
72 struct list_head *uf);
73
74#else /* CONFIG_USERFAULTFD */
75
76/* mm helpers */
77static inline int handle_userfault(struct vm_fault *vmf, unsigned long reason)
78{
79 return VM_FAULT_SIGBUS;
80}
81
82static inline bool is_mergeable_vm_userfaultfd_ctx(struct vm_area_struct *vma,
83 struct vm_userfaultfd_ctx vm_ctx)
84{
85 return true;
86}
87
88static inline bool userfaultfd_missing(struct vm_area_struct *vma)
89{
90 return false;
91}
92
93static inline bool userfaultfd_armed(struct vm_area_struct *vma)
94{
95 return false;
96}
97
98static inline int dup_userfaultfd(struct vm_area_struct *vma,
99 struct list_head *l)
100{
101 return 0;
102}
103
104static inline void dup_userfaultfd_complete(struct list_head *l)
105{
106}
107
108static inline void mremap_userfaultfd_prep(struct vm_area_struct *vma,
109 struct vm_userfaultfd_ctx *ctx)
110{
111}
112
113static inline void mremap_userfaultfd_complete(struct vm_userfaultfd_ctx *ctx,
114 unsigned long from,
115 unsigned long to,
116 unsigned long len)
117{
118}
119
120static inline bool userfaultfd_remove(struct vm_area_struct *vma,
121 unsigned long start,
122 unsigned long end)
123{
124 return true;
125}
126
127static inline int userfaultfd_unmap_prep(struct vm_area_struct *vma,
128 unsigned long start, unsigned long end,
129 struct list_head *uf)
130{
131 return 0;
132}
133
134static inline void userfaultfd_unmap_complete(struct mm_struct *mm,
135 struct list_head *uf)
136{
137}
138
139#endif /* CONFIG_USERFAULTFD */
140
141#endif /* _LINUX_USERFAULTFD_K_H */