| Andrea Arcangeli | 932b18e | 2015-09-04 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 | |
| 30 | extern int handle_userfault(struct vm_area_struct *vma, unsigned long address, |
| 31 | unsigned int flags, unsigned long reason); |
| 32 | |
| Andrea Arcangeli | c1a4de9 | 2015-09-04 15:47:04 -0700 | [diff] [blame] | 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 | |
| Andrea Arcangeli | 932b18e | 2015-09-04 15:46:10 -0700 | [diff] [blame] | 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 */ |