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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 | ||
bae473a4 | 30 | extern int handle_userfault(struct fault_env *fe, unsigned long reason); |
932b18e0 | 31 | |
c1a4de99 AA |
32 | extern ssize_t mcopy_atomic(struct mm_struct *dst_mm, unsigned long dst_start, |
33 | unsigned long src_start, unsigned long len); | |
34 | extern ssize_t mfill_zeropage(struct mm_struct *dst_mm, | |
35 | unsigned long dst_start, | |
36 | unsigned long len); | |
37 | ||
932b18e0 AA |
38 | /* mm helpers */ |
39 | static 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 | ||
45 | static inline bool userfaultfd_missing(struct vm_area_struct *vma) | |
46 | { | |
47 | return vma->vm_flags & VM_UFFD_MISSING; | |
48 | } | |
49 | ||
50 | static inline bool userfaultfd_armed(struct vm_area_struct *vma) | |
51 | { | |
52 | return vma->vm_flags & (VM_UFFD_MISSING | VM_UFFD_WP); | |
53 | } | |
54 | ||
55 | #else /* CONFIG_USERFAULTFD */ | |
56 | ||
57 | /* mm helpers */ | |
bae473a4 | 58 | static inline int handle_userfault(struct fault_env *fe, unsigned long reason) |
932b18e0 AA |
59 | { |
60 | return VM_FAULT_SIGBUS; | |
61 | } | |
62 | ||
63 | static inline bool is_mergeable_vm_userfaultfd_ctx(struct vm_area_struct *vma, | |
64 | struct vm_userfaultfd_ctx vm_ctx) | |
65 | { | |
66 | return true; | |
67 | } | |
68 | ||
69 | static inline bool userfaultfd_missing(struct vm_area_struct *vma) | |
70 | { | |
71 | return false; | |
72 | } | |
73 | ||
74 | static inline bool userfaultfd_armed(struct vm_area_struct *vma) | |
75 | { | |
76 | return false; | |
77 | } | |
78 | ||
79 | #endif /* CONFIG_USERFAULTFD */ | |
80 | ||
81 | #endif /* _LINUX_USERFAULTFD_K_H */ |