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https://github.com/torvalds/linux.git
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Andrea Arcangeli
c1a4de99fa
This implements mcopy_atomic and mfill_zeropage that are the lowlevel VM methods that are invoked respectively by the UFFDIO_COPY and UFFDIO_ZEROPAGE userfaultfd commands. Signed-off-by: Andrea Arcangeli <[email protected]> Acked-by: Pavel Emelyanov <[email protected]> Cc: Sanidhya Kashyap <[email protected]> Cc: [email protected] Cc: "Kirill A. Shutemov" <[email protected]> Cc: Andres Lagar-Cavilla <[email protected]> Cc: Dave Hansen <[email protected]> Cc: Paolo Bonzini <[email protected]> Cc: Rik van Riel <[email protected]> Cc: Mel Gorman <[email protected]> Cc: Andy Lutomirski <[email protected]> Cc: Hugh Dickins <[email protected]> Cc: Peter Feiner <[email protected]> Cc: "Dr. David Alan Gilbert" <[email protected]> Cc: Johannes Weiner <[email protected]> Cc: "Huangpeng (Peter)" <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
86 lines
2.1 KiB
C
86 lines
2.1 KiB
C
/*
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* include/linux/userfaultfd_k.h
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*
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* Copyright (C) 2015 Red Hat, Inc.
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*
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*/
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#ifndef _LINUX_USERFAULTFD_K_H
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#define _LINUX_USERFAULTFD_K_H
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#ifdef CONFIG_USERFAULTFD
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#include <linux/userfaultfd.h> /* linux/include/uapi/linux/userfaultfd.h */
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#include <linux/fcntl.h>
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/*
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* CAREFUL: Check include/uapi/asm-generic/fcntl.h when defining
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* new flags, since they might collide with O_* ones. We want
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* to re-use O_* flags that couldn't possibly have a meaning
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* from userfaultfd, in order to leave a free define-space for
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* shared O_* flags.
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*/
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#define UFFD_CLOEXEC O_CLOEXEC
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#define UFFD_NONBLOCK O_NONBLOCK
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#define UFFD_SHARED_FCNTL_FLAGS (O_CLOEXEC | O_NONBLOCK)
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#define UFFD_FLAGS_SET (EFD_SHARED_FCNTL_FLAGS)
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extern int handle_userfault(struct vm_area_struct *vma, unsigned long address,
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unsigned int flags, unsigned long reason);
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extern ssize_t mcopy_atomic(struct mm_struct *dst_mm, unsigned long dst_start,
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unsigned long src_start, unsigned long len);
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extern ssize_t mfill_zeropage(struct mm_struct *dst_mm,
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unsigned long dst_start,
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unsigned long len);
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/* mm helpers */
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static inline bool is_mergeable_vm_userfaultfd_ctx(struct vm_area_struct *vma,
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struct vm_userfaultfd_ctx vm_ctx)
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{
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return vma->vm_userfaultfd_ctx.ctx == vm_ctx.ctx;
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}
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static inline bool userfaultfd_missing(struct vm_area_struct *vma)
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{
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return vma->vm_flags & VM_UFFD_MISSING;
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}
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static inline bool userfaultfd_armed(struct vm_area_struct *vma)
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{
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return vma->vm_flags & (VM_UFFD_MISSING | VM_UFFD_WP);
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}
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#else /* CONFIG_USERFAULTFD */
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/* mm helpers */
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static inline int handle_userfault(struct vm_area_struct *vma,
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unsigned long address,
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unsigned int flags,
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unsigned long reason)
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{
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return VM_FAULT_SIGBUS;
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}
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static inline bool is_mergeable_vm_userfaultfd_ctx(struct vm_area_struct *vma,
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struct vm_userfaultfd_ctx vm_ctx)
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{
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return true;
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}
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static inline bool userfaultfd_missing(struct vm_area_struct *vma)
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{
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return false;
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}
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static inline bool userfaultfd_armed(struct vm_area_struct *vma)
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{
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return false;
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}
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#endif /* CONFIG_USERFAULTFD */
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#endif /* _LINUX_USERFAULTFD_K_H */
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