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gerrit-public.fairphone.software / kernel / msm-5.4 / 72f87654c69690ff4721bd9b4a39983f971de9a5 / . / include / linux / userfaultfd_k.h
blob: 7f318a46044b0a88d88023efcee12841978524bd [file] [log] [blame]
Andrea Arcangeli932b18e2015-09-04 15:46:10 -0700[diff] [blame]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
Jan Kara82b0f8c2016-12-14 15:06:58 -0800[diff] [blame]30extern int handle_userfault(struct vm_fault *vmf, unsigned long reason);
Andrea Arcangeli932b18e2015-09-04 15:46:10 -0700[diff] [blame]31
Andrea Arcangelic1a4de92015-09-04 15:47:04 -0700[diff] [blame]32extern ssize_t mcopy_atomic(struct mm_struct *dst_mm, unsigned long dst_start,
33 unsigned long src_start, unsigned long len);
34extern ssize_t mfill_zeropage(struct mm_struct *dst_mm,
35 unsigned long dst_start,
36 unsigned long len);
37
Andrea Arcangeli932b18e2015-09-04 15:46:10 -0700[diff] [blame]38/* mm helpers */
39static 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
45static inline bool userfaultfd_missing(struct vm_area_struct *vma)
46{
47 return vma->vm_flags & VM_UFFD_MISSING;
48}
49
50static inline bool userfaultfd_armed(struct vm_area_struct *vma)
51{
52 return vma->vm_flags & (VM_UFFD_MISSING | VM_UFFD_WP);
53}
54
Pavel Emelyanov893e26e2017-02-22 15:42:27 -0800[diff] [blame]55extern int dup_userfaultfd(struct vm_area_struct *, struct list_head *);
56extern void dup_userfaultfd_complete(struct list_head *);
57
Pavel Emelyanov72f87652017-02-22 15:42:34 -0800[diff] [blame^]58extern void mremap_userfaultfd_prep(struct vm_area_struct *,
59 struct vm_userfaultfd_ctx *);
60extern void mremap_userfaultfd_complete(struct vm_userfaultfd_ctx,
61 unsigned long from, unsigned long to,
62 unsigned long len);
63
Andrea Arcangeli932b18e2015-09-04 15:46:10 -0700[diff] [blame]64#else /* CONFIG_USERFAULTFD */
65
66/* mm helpers */
Jan Kara82b0f8c2016-12-14 15:06:58 -0800[diff] [blame]67static inline int handle_userfault(struct vm_fault *vmf, unsigned long reason)
Andrea Arcangeli932b18e2015-09-04 15:46:10 -0700[diff] [blame]68{
69 return VM_FAULT_SIGBUS;
70}
71
72static inline bool is_mergeable_vm_userfaultfd_ctx(struct vm_area_struct *vma,
73 struct vm_userfaultfd_ctx vm_ctx)
74{
75 return true;
76}
77
78static inline bool userfaultfd_missing(struct vm_area_struct *vma)
79{
80 return false;
81}
82
83static inline bool userfaultfd_armed(struct vm_area_struct *vma)
84{
85 return false;
86}
87
Pavel Emelyanov893e26e2017-02-22 15:42:27 -0800[diff] [blame]88static inline int dup_userfaultfd(struct vm_area_struct *vma,
89 struct list_head *l)
90{
91 return 0;
92}
93
94static inline void dup_userfaultfd_complete(struct list_head *l)
95{
96}
97
Pavel Emelyanov72f87652017-02-22 15:42:34 -0800[diff] [blame^]98static inline void mremap_userfaultfd_prep(struct vm_area_struct *vma,
99 struct vm_userfaultfd_ctx *ctx)
100{
101}
102
103static inline void mremap_userfaultfd_complete(struct vm_userfaultfd_ctx ctx,
104 unsigned long from,
105 unsigned long to,
106 unsigned long len)
107{
108}
Andrea Arcangeli932b18e2015-09-04 15:46:10 -0700[diff] [blame]109#endif /* CONFIG_USERFAULTFD */
110
111#endif /* _LINUX_USERFAULTFD_K_H */