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Commit 932b18e0 authored by Andrea Arcangeli's avatar Andrea Arcangeli Committed by Linus Torvalds
Browse files

userfaultfd: linux/userfaultfd_k.h 



Kernel header defining the methods needed by the VM common code to
interact with the userfaultfd.

Signed-off-by: default avatarAndrea Arcangeli <aarcange@redhat.com>
Acked-by: default avatarPavel Emelyanov <xemul@parallels.com>
Cc: Sanidhya Kashyap <sanidhya.gatech@gmail.com>
Cc: zhang.zhanghailiang@huawei.com
Cc: "Kirill A. Shutemov" <kirill@shutemov.name>
Cc: Andres Lagar-Cavilla <andreslc@google.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Hugh Dickins <hughd@google.com>
Cc: Peter Feiner <pfeiner@google.com>
Cc: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: "Huangpeng (Peter)" <peter.huangpeng@huawei.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 1038628d

include/linux/userfaultfd_k.h

0 → 100644
+79 −0
Original line number Diff line number Diff line 
/*

 *  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>



/*

 * 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 handle_userfault(struct vm_area_struct *vma, unsigned long address,

			    unsigned int flags, unsigned long reason);



/* 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_armed(struct vm_area_struct *vma)

{

	return vma->vm_flags & (VM_UFFD_MISSING | VM_UFFD_WP);

}



#else /* CONFIG_USERFAULTFD */



/* mm helpers */

static inline int handle_userfault(struct vm_area_struct *vma,

				   unsigned long address,

				   unsigned int flags,

				   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_armed(struct vm_area_struct *vma)

{

	return false;

}



#endif /* CONFIG_USERFAULTFD */



#endif /* _LINUX_USERFAULTFD_K_H */