[mirror_ubuntu-artful-kernel.git] / include / linux / userfaultfd_k.h

/*
 *  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_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);
extern ssize_t mfill_zeropage(struct mm_struct *dst_mm,
			      unsigned long dst_start,
			      unsigned long len);

/* 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);
}

extern int dup_userfaultfd(struct vm_area_struct *, struct list_head *);
extern void dup_userfaultfd_complete(struct list_head *);

#else /* CONFIG_USERFAULTFD */

/* mm helpers */
static inline int 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_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)
{
}

#endif /* CONFIG_USERFAULTFD */

#endif /* _LINUX_USERFAULTFD_K_H */
Commit	Line	Data
932b18e0 AA	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
82b0f8c3	30	extern int handle_userfault(struct vm_fault *vmf, unsigned long reason);
932b18e0	31
c1a4de99 AA	32	extern ssize_t mcopy_atomic(struct mm_struct *dst_mm, unsigned long dst_start,
	33	unsigned long src_start, unsigned long len);
	34	extern ssize_t mfill_zeropage(struct mm_struct *dst_mm,
	35	unsigned long dst_start,
	36	unsigned long len);
	37
932b18e0 AA	38	/* mm helpers */
	39	static inline bool is_mergeable_vm_userfaultfd_ctx(struct vm_area_struct *vma,
	40	struct vm_userfaultfd_ctx vm_ctx)
	41	{
	42	return vma->vm_userfaultfd_ctx.ctx == vm_ctx.ctx;
	43	}
	44
	45	static inline bool userfaultfd_missing(struct vm_area_struct *vma)
	46	{
	47	return vma->vm_flags & VM_UFFD_MISSING;
	48	}
	49
	50	static inline bool userfaultfd_armed(struct vm_area_struct *vma)
	51	{
	52	return vma->vm_flags & (VM_UFFD_MISSING \| VM_UFFD_WP);
	53	}
	54
893e26e6 PE	55	extern int dup_userfaultfd(struct vm_area_struct , struct list_head );
	56	extern void dup_userfaultfd_complete(struct list_head *);
	57
932b18e0 AA	58	#else /* CONFIG_USERFAULTFD */
	59
	60	/* mm helpers */
82b0f8c3	61	static inline int handle_userfault(struct vm_fault *vmf, unsigned long reason)
932b18e0 AA	62	{
	63	return VM_FAULT_SIGBUS;
	64	}
	65
	66	static inline bool is_mergeable_vm_userfaultfd_ctx(struct vm_area_struct *vma,
	67	struct vm_userfaultfd_ctx vm_ctx)
	68	{
	69	return true;
	70	}
	71
	72	static inline bool userfaultfd_missing(struct vm_area_struct *vma)
	73	{
	74	return false;
	75	}
	76
	77	static inline bool userfaultfd_armed(struct vm_area_struct *vma)
	78	{
	79	return false;
	80	}
	81
893e26e6 PE	82	static inline int dup_userfaultfd(struct vm_area_struct *vma,
	83	struct list_head *l)
	84	{
	85	return 0;
	86	}
	87
	88	static inline void dup_userfaultfd_complete(struct list_head *l)
	89	{
	90	}
	91
932b18e0 AA	92	#endif /* CONFIG_USERFAULTFD */
	93
	94	#endif /* _LINUX_USERFAULTFD_K_H */