2 * include/linux/userfaultfd_k.h
4 * Copyright (C) 2015 Red Hat, Inc.
8 #ifndef _LINUX_USERFAULTFD_K_H
9 #define _LINUX_USERFAULTFD_K_H
11 #ifdef CONFIG_USERFAULTFD
13 #include <linux/userfaultfd.h> /* linux/include/uapi/linux/userfaultfd.h */
15 #include <linux/fcntl.h>
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
24 #define UFFD_CLOEXEC O_CLOEXEC
25 #define UFFD_NONBLOCK O_NONBLOCK
27 #define UFFD_SHARED_FCNTL_FLAGS (O_CLOEXEC | O_NONBLOCK)
28 #define UFFD_FLAGS_SET (EFD_SHARED_FCNTL_FLAGS)
30 extern int handle_userfault(struct vm_area_struct *vma, unsigned long address,
31 unsigned int flags, unsigned long reason);
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,
40 static inline bool is_mergeable_vm_userfaultfd_ctx(struct vm_area_struct *vma,
41 struct vm_userfaultfd_ctx vm_ctx)
43 return vma->vm_userfaultfd_ctx.ctx == vm_ctx.ctx;
46 static inline bool userfaultfd_missing(struct vm_area_struct *vma)
48 return vma->vm_flags & VM_UFFD_MISSING;
51 static inline bool userfaultfd_armed(struct vm_area_struct *vma)
53 return vma->vm_flags & (VM_UFFD_MISSING | VM_UFFD_WP);
56 #else /* CONFIG_USERFAULTFD */
59 static inline int handle_userfault(struct vm_area_struct *vma,
60 unsigned long address,
64 return VM_FAULT_SIGBUS;
67 static inline bool is_mergeable_vm_userfaultfd_ctx(struct vm_area_struct *vma,
68 struct vm_userfaultfd_ctx vm_ctx)
73 static inline bool userfaultfd_missing(struct vm_area_struct *vma)
78 static inline bool userfaultfd_armed(struct vm_area_struct *vma)
83 #endif /* CONFIG_USERFAULTFD */
85 #endif /* _LINUX_USERFAULTFD_K_H */