Line data Source code
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 : #include <linux/mm.h>
18 : #include <asm-generic/pgtable_uffd.h>
19 :
20 : /*
21 : * CAREFUL: Check include/uapi/asm-generic/fcntl.h when defining
22 : * new flags, since they might collide with O_* ones. We want
23 : * to re-use O_* flags that couldn't possibly have a meaning
24 : * from userfaultfd, in order to leave a free define-space for
25 : * shared O_* flags.
26 : */
27 : #define UFFD_CLOEXEC O_CLOEXEC
28 : #define UFFD_NONBLOCK O_NONBLOCK
29 :
30 : #define UFFD_SHARED_FCNTL_FLAGS (O_CLOEXEC | O_NONBLOCK)
31 : #define UFFD_FLAGS_SET (EFD_SHARED_FCNTL_FLAGS)
32 :
33 : extern int sysctl_unprivileged_userfaultfd;
34 :
35 : extern vm_fault_t handle_userfault(struct vm_fault *vmf, unsigned long reason);
36 :
37 : extern ssize_t mcopy_atomic(struct mm_struct *dst_mm, unsigned long dst_start,
38 : unsigned long src_start, unsigned long len,
39 : bool *mmap_changing, __u64 mode);
40 : extern ssize_t mfill_zeropage(struct mm_struct *dst_mm,
41 : unsigned long dst_start,
42 : unsigned long len,
43 : bool *mmap_changing);
44 : extern int mwriteprotect_range(struct mm_struct *dst_mm,
45 : unsigned long start, unsigned long len,
46 : bool enable_wp, bool *mmap_changing);
47 :
48 : /* mm helpers */
49 : static inline bool is_mergeable_vm_userfaultfd_ctx(struct vm_area_struct *vma,
50 : struct vm_userfaultfd_ctx vm_ctx)
51 : {
52 : return vma->vm_userfaultfd_ctx.ctx == vm_ctx.ctx;
53 : }
54 :
55 : static inline bool userfaultfd_missing(struct vm_area_struct *vma)
56 : {
57 : return vma->vm_flags & VM_UFFD_MISSING;
58 : }
59 :
60 : static inline bool userfaultfd_wp(struct vm_area_struct *vma)
61 : {
62 : return vma->vm_flags & VM_UFFD_WP;
63 : }
64 :
65 : static inline bool userfaultfd_pte_wp(struct vm_area_struct *vma,
66 : pte_t pte)
67 : {
68 : return userfaultfd_wp(vma) && pte_uffd_wp(pte);
69 : }
70 :
71 : static inline bool userfaultfd_huge_pmd_wp(struct vm_area_struct *vma,
72 : pmd_t pmd)
73 : {
74 : return userfaultfd_wp(vma) && pmd_uffd_wp(pmd);
75 : }
76 :
77 : static inline bool userfaultfd_armed(struct vm_area_struct *vma)
78 : {
79 : return vma->vm_flags & (VM_UFFD_MISSING | VM_UFFD_WP);
80 : }
81 :
82 : extern int dup_userfaultfd(struct vm_area_struct *, struct list_head *);
83 : extern void dup_userfaultfd_complete(struct list_head *);
84 :
85 : extern void mremap_userfaultfd_prep(struct vm_area_struct *,
86 : struct vm_userfaultfd_ctx *);
87 : extern void mremap_userfaultfd_complete(struct vm_userfaultfd_ctx *,
88 : unsigned long from, unsigned long to,
89 : unsigned long len);
90 :
91 : extern bool userfaultfd_remove(struct vm_area_struct *vma,
92 : unsigned long start,
93 : unsigned long end);
94 :
95 : extern int userfaultfd_unmap_prep(struct vm_area_struct *vma,
96 : unsigned long start, unsigned long end,
97 : struct list_head *uf);
98 : extern void userfaultfd_unmap_complete(struct mm_struct *mm,
99 : struct list_head *uf);
100 :
101 : #else /* CONFIG_USERFAULTFD */
102 :
103 : /* mm helpers */
104 : static inline vm_fault_t handle_userfault(struct vm_fault *vmf,
105 : unsigned long reason)
106 : {
107 : return VM_FAULT_SIGBUS;
108 : }
109 :
110 3538 : static inline bool is_mergeable_vm_userfaultfd_ctx(struct vm_area_struct *vma,
111 : struct vm_userfaultfd_ctx vm_ctx)
112 : {
113 3538 : return true;
114 : }
115 :
116 43719 : static inline bool userfaultfd_missing(struct vm_area_struct *vma)
117 : {
118 43719 : return false;
119 : }
120 :
121 47433 : static inline bool userfaultfd_wp(struct vm_area_struct *vma)
122 : {
123 47433 : return false;
124 : }
125 :
126 47433 : static inline bool userfaultfd_pte_wp(struct vm_area_struct *vma,
127 : pte_t pte)
128 : {
129 47433 : return false;
130 : }
131 :
132 0 : static inline bool userfaultfd_huge_pmd_wp(struct vm_area_struct *vma,
133 : pmd_t pmd)
134 : {
135 0 : return false;
136 : }
137 :
138 :
139 2028 : static inline bool userfaultfd_armed(struct vm_area_struct *vma)
140 : {
141 2028 : return false;
142 : }
143 :
144 44988 : static inline int dup_userfaultfd(struct vm_area_struct *vma,
145 : struct list_head *l)
146 : {
147 44988 : return 0;
148 : }
149 :
150 858 : static inline void dup_userfaultfd_complete(struct list_head *l)
151 : {
152 858 : }
153 :
154 : static inline void mremap_userfaultfd_prep(struct vm_area_struct *vma,
155 : struct vm_userfaultfd_ctx *ctx)
156 : {
157 : }
158 :
159 42 : static inline void mremap_userfaultfd_complete(struct vm_userfaultfd_ctx *ctx,
160 : unsigned long from,
161 : unsigned long to,
162 : unsigned long len)
163 : {
164 42 : }
165 :
166 4 : static inline bool userfaultfd_remove(struct vm_area_struct *vma,
167 : unsigned long start,
168 : unsigned long end)
169 : {
170 4 : return true;
171 : }
172 :
173 : static inline int userfaultfd_unmap_prep(struct vm_area_struct *vma,
174 : unsigned long start, unsigned long end,
175 : struct list_head *uf)
176 : {
177 : return 0;
178 : }
179 :
180 30784 : static inline void userfaultfd_unmap_complete(struct mm_struct *mm,
181 : struct list_head *uf)
182 : {
183 30784 : }
184 :
185 : #endif /* CONFIG_USERFAULTFD */
186 :
187 : #endif /* _LINUX_USERFAULTFD_K_H */
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