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932b18e0 AA |
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 | ||
30 | extern int handle_userfault(struct vm_area_struct *vma, unsigned long address, | |
31 | unsigned int flags, unsigned long reason); | |
32 | ||
c1a4de99 AA |
33 | extern ssize_t mcopy_atomic(struct mm_struct *dst_mm, unsigned long dst_start, |
34 | unsigned long src_start, unsigned long len); | |
35 | extern ssize_t mfill_zeropage(struct mm_struct *dst_mm, | |
36 | unsigned long dst_start, | |
37 | unsigned long len); | |
38 | ||
932b18e0 AA |
39 | /* mm helpers */ |
40 | static inline bool is_mergeable_vm_userfaultfd_ctx(struct vm_area_struct *vma, | |
41 | struct vm_userfaultfd_ctx vm_ctx) | |
42 | { | |
43 | return vma->vm_userfaultfd_ctx.ctx == vm_ctx.ctx; | |
44 | } | |
45 | ||
46 | static inline bool userfaultfd_missing(struct vm_area_struct *vma) | |
47 | { | |
48 | return vma->vm_flags & VM_UFFD_MISSING; | |
49 | } | |
50 | ||
51 | static inline bool userfaultfd_armed(struct vm_area_struct *vma) | |
52 | { | |
53 | return vma->vm_flags & (VM_UFFD_MISSING | VM_UFFD_WP); | |
54 | } | |
55 | ||
56 | #else /* CONFIG_USERFAULTFD */ | |
57 | ||
58 | /* mm helpers */ | |
59 | static inline int handle_userfault(struct vm_area_struct *vma, | |
60 | unsigned long address, | |
61 | unsigned int flags, | |
62 | unsigned long reason) | |
63 | { | |
64 | return VM_FAULT_SIGBUS; | |
65 | } | |
66 | ||
67 | static inline bool is_mergeable_vm_userfaultfd_ctx(struct vm_area_struct *vma, | |
68 | struct vm_userfaultfd_ctx vm_ctx) | |
69 | { | |
70 | return true; | |
71 | } | |
72 | ||
73 | static inline bool userfaultfd_missing(struct vm_area_struct *vma) | |
74 | { | |
75 | return false; | |
76 | } | |
77 | ||
78 | static inline bool userfaultfd_armed(struct vm_area_struct *vma) | |
79 | { | |
80 | return false; | |
81 | } | |
82 | ||
83 | #endif /* CONFIG_USERFAULTFD */ | |
84 | ||
85 | #endif /* _LINUX_USERFAULTFD_K_H */ |