Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
tjh.dev
kernel
os
linux
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
30extern int handle_userfault(struct fault_env *fe, unsigned long reason);
31
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
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
55#else /* CONFIG_USERFAULTFD */
56
57/* mm helpers */
58static inline int handle_userfault(struct fault_env *fe, unsigned long reason)
59{
60 return VM_FAULT_SIGBUS;
61}
62
63static 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
69static inline bool userfaultfd_missing(struct vm_area_struct *vma)
70{
71 return false;
72}
73
74static 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 */