summaryrefslogtreecommitdiff
path: root/include/linux/userfaultfd_k.h
blob: 0468548acebfef5431ea7bfd6f565cfdfb73f348 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
/*
 *  include/linux/userfaultfd_k.h
 *
 *  Copyright (C) 2015  Red Hat, Inc.
 *
 */

#ifndef _LINUX_USERFAULTFD_K_H
#define _LINUX_USERFAULTFD_K_H

#ifdef CONFIG_USERFAULTFD

#include <linux/userfaultfd.h> /* linux/include/uapi/linux/userfaultfd.h */

#include <linux/fcntl.h>

/*
 * CAREFUL: Check include/uapi/asm-generic/fcntl.h when defining
 * new flags, since they might collide with O_* ones. We want
 * to re-use O_* flags that couldn't possibly have a meaning
 * 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)

extern int handle_userfault(struct vm_fault *vmf, unsigned long reason);

extern ssize_t mcopy_atomic(struct mm_struct *dst_mm, unsigned long dst_start,
			    unsigned long src_start, unsigned long len);
extern ssize_t mfill_zeropage(struct mm_struct *dst_mm,
			      unsigned long dst_start,
			      unsigned long len);

/* mm helpers */
static inline bool is_mergeable_vm_userfaultfd_ctx(struct vm_area_struct *vma,
					struct vm_userfaultfd_ctx vm_ctx)
{
	return vma->vm_userfaultfd_ctx.ctx == vm_ctx.ctx;
}

static inline bool userfaultfd_missing(struct vm_area_struct *vma)
{
	return vma->vm_flags & VM_UFFD_MISSING;
}

static inline bool userfaultfd_armed(struct vm_area_struct *vma)
{
	return vma->vm_flags & (VM_UFFD_MISSING | VM_UFFD_WP);
}

extern int dup_userfaultfd(struct vm_area_struct *, struct list_head *);
extern void dup_userfaultfd_complete(struct list_head *);

extern void mremap_userfaultfd_prep(struct vm_area_struct *,
				    struct vm_userfaultfd_ctx *);
extern void mremap_userfaultfd_complete(struct vm_userfaultfd_ctx *,
					unsigned long from, unsigned long to,
					unsigned long len);

extern void userfaultfd_remove(struct vm_area_struct *vma,
			       struct vm_area_struct **prev,
			       unsigned long start,
			       unsigned long end);

extern int userfaultfd_unmap_prep(struct vm_area_struct *vma,
				  unsigned long start, unsigned long end,
				  struct list_head *uf);
extern void userfaultfd_unmap_complete(struct mm_struct *mm,
				       struct list_head *uf);

extern void userfaultfd_exit(struct mm_struct *mm);

#else /* CONFIG_USERFAULTFD */

/* mm helpers */
static inline int handle_userfault(struct vm_fault *vmf, unsigned long reason)
{
	return VM_FAULT_SIGBUS;
}

static inline bool is_mergeable_vm_userfaultfd_ctx(struct vm_area_struct *vma,
					struct vm_userfaultfd_ctx vm_ctx)
{
	return true;
}

static inline bool userfaultfd_missing(struct vm_area_struct *vma)
{
	return false;
}

static inline bool userfaultfd_armed(struct vm_area_struct *vma)
{
	return false;
}

static inline int dup_userfaultfd(struct vm_area_struct *vma,
				  struct list_head *l)
{
	return 0;
}

static inline void dup_userfaultfd_complete(struct list_head *l)
{
}

static inline void mremap_userfaultfd_prep(struct vm_area_struct *vma,
					   struct vm_userfaultfd_ctx *ctx)
{
}

static inline void mremap_userfaultfd_complete(struct vm_userfaultfd_ctx *ctx,
					       unsigned long from,
					       unsigned long to,
					       unsigned long len)
{
}

static inline void userfaultfd_remove(struct vm_area_struct *vma,
				      struct vm_area_struct **prev,
				      unsigned long start,
				      unsigned long end)
{
}

static inline int userfaultfd_unmap_prep(struct vm_area_struct *vma,
					 unsigned long start, unsigned long end,
					 struct list_head *uf)
{
	return 0;
}

static inline void userfaultfd_unmap_complete(struct mm_struct *mm,
					      struct list_head *uf)
{
}

static inline void userfaultfd_exit(struct mm_struct *mm)
{
}

#endif /* CONFIG_USERFAULTFD */

#endif /* _LINUX_USERFAULTFD_K_H */