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

/* 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>

/*
 * 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 *);

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 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)
{
}

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 */
Commit	Line	Data
b2441318	1	/* SPDX-License-Identifier: GPL-2.0 */
932b18e0 AA	2	/*
	3	* include/linux/userfaultfd_k.h
	4	*
	5	* Copyright (C) 2015 Red Hat, Inc.
	6	*
	7	*/
	8
	9	#ifndef _LINUX_USERFAULTFD_K_H
	10	#define _LINUX_USERFAULTFD_K_H
	11
	12	#ifdef CONFIG_USERFAULTFD
	13
	14	#include <linux/userfaultfd.h> /* linux/include/uapi/linux/userfaultfd.h */
	15
	16	#include <linux/fcntl.h>
	17
	18	/*
	19	* CAREFUL: Check include/uapi/asm-generic/fcntl.h when defining
	20	* new flags, since they might collide with O_* ones. We want
	21	* to re-use O_* flags that couldn't possibly have a meaning
	22	* from userfaultfd, in order to leave a free define-space for
	23	* shared O_* flags.
	24	*/
	25	#define UFFD_CLOEXEC O_CLOEXEC
	26	#define UFFD_NONBLOCK O_NONBLOCK
	27
	28	#define UFFD_SHARED_FCNTL_FLAGS (O_CLOEXEC \| O_NONBLOCK)
	29	#define UFFD_FLAGS_SET (EFD_SHARED_FCNTL_FLAGS)
	30
82b0f8c3	31	extern int handle_userfault(struct vm_fault *vmf, unsigned long reason);
932b18e0	32
c1a4de99 AA	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
932b18e0 AA	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
893e26e6 PE	56	extern int dup_userfaultfd(struct vm_area_struct , struct list_head );
	57	extern void dup_userfaultfd_complete(struct list_head *);
	58
72f87654 PE	59	extern void mremap_userfaultfd_prep(struct vm_area_struct *,
72f87654 PE	60	struct vm_userfaultfd_ctx *);
90794bf1	61	extern void mremap_userfaultfd_complete(struct vm_userfaultfd_ctx *,
72f87654 PE	62	unsigned long from, unsigned long to,
	63	unsigned long len);
	64
70ccb92f	65	extern bool userfaultfd_remove(struct vm_area_struct *vma,
d811914d MR	66	unsigned long start,
d811914d MR	67	unsigned long end);
05ce7724	68
897ab3e0 MR	69	extern int userfaultfd_unmap_prep(struct vm_area_struct *vma,
	70	unsigned long start, unsigned long end,
	71	struct list_head *uf);
	72	extern void userfaultfd_unmap_complete(struct mm_struct *mm,
	73	struct list_head *uf);
	74
932b18e0 AA	75	#else /* CONFIG_USERFAULTFD */
	76
	77	/* mm helpers */
82b0f8c3	78	static inline int handle_userfault(struct vm_fault *vmf, unsigned long reason)
932b18e0 AA	79	{
	80	return VM_FAULT_SIGBUS;
	81	}
	82
	83	static inline bool is_mergeable_vm_userfaultfd_ctx(struct vm_area_struct *vma,
	84	struct vm_userfaultfd_ctx vm_ctx)
	85	{
	86	return true;
	87	}
	88
	89	static inline bool userfaultfd_missing(struct vm_area_struct *vma)
	90	{
	91	return false;
	92	}
	93
	94	static inline bool userfaultfd_armed(struct vm_area_struct *vma)
	95	{
	96	return false;
	97	}
	98
893e26e6 PE	99	static inline int dup_userfaultfd(struct vm_area_struct *vma,
	100	struct list_head *l)
	101	{
	102	return 0;
	103	}
	104
	105	static inline void dup_userfaultfd_complete(struct list_head *l)
	106	{
	107	}
	108
72f87654 PE	109	static inline void mremap_userfaultfd_prep(struct vm_area_struct *vma,
	110	struct vm_userfaultfd_ctx *ctx)
	111	{
	112	}
	113
90794bf1	114	static inline void mremap_userfaultfd_complete(struct vm_userfaultfd_ctx *ctx,
72f87654 PE	115	unsigned long from,
	116	unsigned long to,
	117	unsigned long len)
	118	{
	119	}
05ce7724	120
70ccb92f	121	static inline bool userfaultfd_remove(struct vm_area_struct *vma,
d811914d MR	122	unsigned long start,
d811914d MR	123	unsigned long end)
05ce7724	124	{
70ccb92f	125	return true;
05ce7724	126	}
897ab3e0 MR	127
	128	static inline int userfaultfd_unmap_prep(struct vm_area_struct *vma,
	129	unsigned long start, unsigned long end,
	130	struct list_head *uf)
	131	{
	132	return 0;
	133	}
	134
	135	static inline void userfaultfd_unmap_complete(struct mm_struct *mm,
	136	struct list_head *uf)
	137	{
	138	}
ca49ca71	139
932b18e0 AA	140	#endif /* CONFIG_USERFAULTFD */
	141
	142	#endif /* _LINUX_USERFAULTFD_K_H */