1 | /* SPDX-License-Identifier: GPL-2.0 */ |
2 | /* |
3 | * include/linux/userfaultfd_k.h |
4 | * |
5 | * Copyright (C) 2015 Red Hat, Inc. |
6 | * |
7 | */ |
8 | |
9 | #ifndef _LINUX_USERFAULTFD_K_H |
10 | #define _LINUX_USERFAULTFD_K_H |
11 | |
12 | #ifdef CONFIG_USERFAULTFD |
13 | |
14 | #include <linux/userfaultfd.h> /* linux/include/uapi/linux/userfaultfd.h */ |
15 | |
16 | #include <linux/fcntl.h> |
17 | |
18 | /* |
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 |
23 | * shared O_* flags. |
24 | */ |
25 | #define UFFD_CLOEXEC O_CLOEXEC |
26 | #define UFFD_NONBLOCK O_NONBLOCK |
27 | |
28 | #define UFFD_SHARED_FCNTL_FLAGS (O_CLOEXEC | O_NONBLOCK) |
29 | #define UFFD_FLAGS_SET (EFD_SHARED_FCNTL_FLAGS) |
30 | |
31 | extern vm_fault_t handle_userfault(struct vm_fault *vmf, unsigned long reason); |
32 | |
33 | extern ssize_t mcopy_atomic(struct mm_struct *dst_mm, unsigned long dst_start, |
34 | unsigned long src_start, unsigned long len, |
35 | bool *mmap_changing); |
36 | extern ssize_t mfill_zeropage(struct mm_struct *dst_mm, |
37 | unsigned long dst_start, |
38 | unsigned long len, |
39 | bool *mmap_changing); |
40 | |
41 | /* mm helpers */ |
42 | static inline bool is_mergeable_vm_userfaultfd_ctx(struct vm_area_struct *vma, |
43 | struct vm_userfaultfd_ctx vm_ctx) |
44 | { |
45 | return vma->vm_userfaultfd_ctx.ctx == vm_ctx.ctx; |
46 | } |
47 | |
48 | static inline bool userfaultfd_missing(struct vm_area_struct *vma) |
49 | { |
50 | return vma->vm_flags & VM_UFFD_MISSING; |
51 | } |
52 | |
53 | static inline bool userfaultfd_armed(struct vm_area_struct *vma) |
54 | { |
55 | return vma->vm_flags & (VM_UFFD_MISSING | VM_UFFD_WP); |
56 | } |
57 | |
58 | extern int dup_userfaultfd(struct vm_area_struct *, struct list_head *); |
59 | extern void dup_userfaultfd_complete(struct list_head *); |
60 | |
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, |
65 | unsigned long len); |
66 | |
67 | extern bool userfaultfd_remove(struct vm_area_struct *vma, |
68 | unsigned long start, |
69 | unsigned long end); |
70 | |
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); |
76 | |
77 | #else /* CONFIG_USERFAULTFD */ |
78 | |
79 | /* mm helpers */ |
80 | static inline vm_fault_t handle_userfault(struct vm_fault *vmf, |
81 | unsigned long reason) |
82 | { |
83 | return VM_FAULT_SIGBUS; |
84 | } |
85 | |
86 | static inline bool is_mergeable_vm_userfaultfd_ctx(struct vm_area_struct *vma, |
87 | struct vm_userfaultfd_ctx vm_ctx) |
88 | { |
89 | return true; |
90 | } |
91 | |
92 | static inline bool userfaultfd_missing(struct vm_area_struct *vma) |
93 | { |
94 | return false; |
95 | } |
96 | |
97 | static inline bool userfaultfd_armed(struct vm_area_struct *vma) |
98 | { |
99 | return false; |
100 | } |
101 | |
102 | static inline int dup_userfaultfd(struct vm_area_struct *vma, |
103 | struct list_head *l) |
104 | { |
105 | return 0; |
106 | } |
107 | |
108 | static inline void dup_userfaultfd_complete(struct list_head *l) |
109 | { |
110 | } |
111 | |
112 | static inline void mremap_userfaultfd_prep(struct vm_area_struct *vma, |
113 | struct vm_userfaultfd_ctx *ctx) |
114 | { |
115 | } |
116 | |
117 | static inline void mremap_userfaultfd_complete(struct vm_userfaultfd_ctx *ctx, |
118 | unsigned long from, |
119 | unsigned long to, |
120 | unsigned long len) |
121 | { |
122 | } |
123 | |
124 | static inline bool userfaultfd_remove(struct vm_area_struct *vma, |
125 | unsigned long start, |
126 | unsigned long end) |
127 | { |
128 | return true; |
129 | } |
130 | |
131 | static inline int userfaultfd_unmap_prep(struct vm_area_struct *vma, |
132 | unsigned long start, unsigned long end, |
133 | struct list_head *uf) |
134 | { |
135 | return 0; |
136 | } |
137 | |
138 | static inline void userfaultfd_unmap_complete(struct mm_struct *mm, |
139 | struct list_head *uf) |
140 | { |
141 | } |
142 | |
143 | #endif /* CONFIG_USERFAULTFD */ |
144 | |
145 | #endif /* _LINUX_USERFAULTFD_K_H */ |
146 | |