diff options
Diffstat (limited to 'include/linux/userfaultfd_k.h')
| -rw-r--r-- | include/linux/userfaultfd_k.h | 187 |
1 files changed, 187 insertions, 0 deletions
diff --git a/include/linux/userfaultfd_k.h b/include/linux/userfaultfd_k.h new file mode 100644 index 000000000..a8e5f3ea9 --- /dev/null +++ b/include/linux/userfaultfd_k.h @@ -0,0 +1,187 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * include/linux/userfaultfd_k.h + * + * Copyright (C) 2015 Red Hat, Inc. + * + */ + +#ifndef _LINUX_USERFAULTFD_K_H +#define _LINUX_USERFAULTFD_K_H + +#ifdef CONFIG_USERFAULTFD + +#include <linux/userfaultfd.h> /* linux/include/uapi/linux/userfaultfd.h */ + +#include <linux/fcntl.h> +#include <linux/mm.h> +#include <asm-generic/pgtable_uffd.h> + +/* + * CAREFUL: Check include/uapi/asm-generic/fcntl.h when defining + * new flags, since they might collide with O_* ones. We want + * to re-use O_* flags that couldn't possibly have a meaning + * from userfaultfd, in order to leave a free define-space for + * shared O_* flags. + */ +#define UFFD_CLOEXEC O_CLOEXEC +#define UFFD_NONBLOCK O_NONBLOCK + +#define UFFD_SHARED_FCNTL_FLAGS (O_CLOEXEC | O_NONBLOCK) +#define UFFD_FLAGS_SET (EFD_SHARED_FCNTL_FLAGS) + +extern int sysctl_unprivileged_userfaultfd; + +extern vm_fault_t handle_userfault(struct vm_fault *vmf, unsigned long reason); + +extern ssize_t mcopy_atomic(struct mm_struct *dst_mm, unsigned long dst_start, + unsigned long src_start, unsigned long len, + bool *mmap_changing, __u64 mode); +extern ssize_t mfill_zeropage(struct mm_struct *dst_mm, + unsigned long dst_start, + unsigned long len, + bool *mmap_changing); +extern int mwriteprotect_range(struct mm_struct *dst_mm, + unsigned long start, unsigned long len, + bool enable_wp, bool *mmap_changing); + +/* mm helpers */ +static inline bool is_mergeable_vm_userfaultfd_ctx(struct vm_area_struct *vma, + struct vm_userfaultfd_ctx vm_ctx) +{ + return vma->vm_userfaultfd_ctx.ctx == vm_ctx.ctx; +} + +static inline bool userfaultfd_missing(struct vm_area_struct *vma) +{ + return vma->vm_flags & VM_UFFD_MISSING; +} + +static inline bool userfaultfd_wp(struct vm_area_struct *vma) +{ + return vma->vm_flags & VM_UFFD_WP; +} + +static inline bool userfaultfd_pte_wp(struct vm_area_struct *vma, + pte_t pte) +{ + return userfaultfd_wp(vma) && pte_uffd_wp(pte); +} + +static inline bool userfaultfd_huge_pmd_wp(struct vm_area_struct *vma, + pmd_t pmd) +{ + return userfaultfd_wp(vma) && pmd_uffd_wp(pmd); +} + +static inline bool userfaultfd_armed(struct vm_area_struct *vma) +{ + return vma->vm_flags & (VM_UFFD_MISSING | VM_UFFD_WP); +} + +extern int dup_userfaultfd(struct vm_area_struct *, struct list_head *); +extern void dup_userfaultfd_complete(struct list_head *); + +extern void mremap_userfaultfd_prep(struct vm_area_struct *, + struct vm_userfaultfd_ctx *); +extern void mremap_userfaultfd_complete(struct vm_userfaultfd_ctx *, + unsigned long from, unsigned long to, + unsigned long len); + +extern bool userfaultfd_remove(struct vm_area_struct *vma, + unsigned long start, + unsigned long end); + +extern int userfaultfd_unmap_prep(struct vm_area_struct *vma, + unsigned long start, unsigned long end, + struct list_head *uf); +extern void userfaultfd_unmap_complete(struct mm_struct *mm, + struct list_head *uf); + +#else /* CONFIG_USERFAULTFD */ + +/* mm helpers */ +static inline vm_fault_t handle_userfault(struct vm_fault *vmf, + unsigned long reason) +{ + return VM_FAULT_SIGBUS; +} + +static inline bool is_mergeable_vm_userfaultfd_ctx(struct vm_area_struct *vma, + struct vm_userfaultfd_ctx vm_ctx) +{ + return true; +} + +static inline bool userfaultfd_missing(struct vm_area_struct *vma) +{ + return false; +} + +static inline bool userfaultfd_wp(struct vm_area_struct *vma) +{ + return false; +} + +static inline bool userfaultfd_pte_wp(struct vm_area_struct *vma, + pte_t pte) +{ + return false; +} + +static inline bool userfaultfd_huge_pmd_wp(struct vm_area_struct *vma, + pmd_t pmd) +{ + return false; +} + + +static inline bool userfaultfd_armed(struct vm_area_struct *vma) +{ + return false; +} + +static inline int dup_userfaultfd(struct vm_area_struct *vma, + struct list_head *l) +{ + return 0; +} + +static inline void dup_userfaultfd_complete(struct list_head *l) +{ +} + +static inline void mremap_userfaultfd_prep(struct vm_area_struct *vma, + struct vm_userfaultfd_ctx *ctx) +{ +} + +static inline void mremap_userfaultfd_complete(struct vm_userfaultfd_ctx *ctx, + unsigned long from, + unsigned long to, + unsigned long len) +{ +} + +static inline bool userfaultfd_remove(struct vm_area_struct *vma, + unsigned long start, + unsigned long end) +{ + return true; +} + +static inline int userfaultfd_unmap_prep(struct vm_area_struct *vma, + unsigned long start, unsigned long end, + struct list_head *uf) +{ + return 0; +} + +static inline void userfaultfd_unmap_complete(struct mm_struct *mm, + struct list_head *uf) +{ +} + +#endif /* CONFIG_USERFAULTFD */ + +#endif /* _LINUX_USERFAULTFD_K_H */ |