[linux-block.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 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);
extern ssize_t mfill_zeropage(struct mm_struct *dst_mm,
			      unsigned long dst_start,
			      unsigned long len,
			      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_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_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
cefdca0a PX	31	extern int sysctl_unprivileged_userfaultfd;
cefdca0a PX	32
2b740303	33	extern vm_fault_t handle_userfault(struct vm_fault *vmf, unsigned long reason);
932b18e0	34
c1a4de99	35	extern ssize_t mcopy_atomic(struct mm_struct *dst_mm, unsigned long dst_start,
df2cc96e MR	36	unsigned long src_start, unsigned long len,
df2cc96e MR	37	bool *mmap_changing);
c1a4de99 AA	38	extern ssize_t mfill_zeropage(struct mm_struct *dst_mm,
c1a4de99 AA	39	unsigned long dst_start,
df2cc96e MR	40	unsigned long len,
df2cc96e MR	41	bool *mmap_changing);
c1a4de99	42
932b18e0 AA	43	/* mm helpers */
	44	static inline bool is_mergeable_vm_userfaultfd_ctx(struct vm_area_struct *vma,
	45	struct vm_userfaultfd_ctx vm_ctx)
	46	{
	47	return vma->vm_userfaultfd_ctx.ctx == vm_ctx.ctx;
	48	}
	49
	50	static inline bool userfaultfd_missing(struct vm_area_struct *vma)
	51	{
	52	return vma->vm_flags & VM_UFFD_MISSING;
	53	}
	54
1df319e0 SL	55	static inline bool userfaultfd_wp(struct vm_area_struct *vma)
	56	{
	57	return vma->vm_flags & VM_UFFD_WP;
	58	}
	59
932b18e0 AA	60	static inline bool userfaultfd_armed(struct vm_area_struct *vma)
	61	{
	62	return vma->vm_flags & (VM_UFFD_MISSING \| VM_UFFD_WP);
	63	}
	64
893e26e6 PE	65	extern int dup_userfaultfd(struct vm_area_struct , struct list_head );
	66	extern void dup_userfaultfd_complete(struct list_head *);
	67
72f87654 PE	68	extern void mremap_userfaultfd_prep(struct vm_area_struct *,
72f87654 PE	69	struct vm_userfaultfd_ctx *);
90794bf1	70	extern void mremap_userfaultfd_complete(struct vm_userfaultfd_ctx *,
72f87654 PE	71	unsigned long from, unsigned long to,
	72	unsigned long len);
	73
70ccb92f	74	extern bool userfaultfd_remove(struct vm_area_struct *vma,
d811914d MR	75	unsigned long start,
d811914d MR	76	unsigned long end);
05ce7724	77
897ab3e0 MR	78	extern int userfaultfd_unmap_prep(struct vm_area_struct *vma,
	79	unsigned long start, unsigned long end,
	80	struct list_head *uf);
	81	extern void userfaultfd_unmap_complete(struct mm_struct *mm,
	82	struct list_head *uf);
	83
932b18e0 AA	84	#else /* CONFIG_USERFAULTFD */
	85
	86	/* mm helpers */
2b740303 SJ	87	static inline vm_fault_t handle_userfault(struct vm_fault *vmf,
2b740303 SJ	88	unsigned long reason)
932b18e0 AA	89	{
	90	return VM_FAULT_SIGBUS;
	91	}
	92
	93	static inline bool is_mergeable_vm_userfaultfd_ctx(struct vm_area_struct *vma,
	94	struct vm_userfaultfd_ctx vm_ctx)
	95	{
	96	return true;
	97	}
	98
	99	static inline bool userfaultfd_missing(struct vm_area_struct *vma)
	100	{
	101	return false;
	102	}
	103
1df319e0 SL	104	static inline bool userfaultfd_wp(struct vm_area_struct *vma)
	105	{
	106	return false;
	107	}
	108
932b18e0 AA	109	static inline bool userfaultfd_armed(struct vm_area_struct *vma)
	110	{
	111	return false;
	112	}
	113
893e26e6 PE	114	static inline int dup_userfaultfd(struct vm_area_struct *vma,
	115	struct list_head *l)
	116	{
	117	return 0;
	118	}
	119
	120	static inline void dup_userfaultfd_complete(struct list_head *l)
	121	{
	122	}
	123
72f87654 PE	124	static inline void mremap_userfaultfd_prep(struct vm_area_struct *vma,
	125	struct vm_userfaultfd_ctx *ctx)
	126	{
	127	}
	128
90794bf1	129	static inline void mremap_userfaultfd_complete(struct vm_userfaultfd_ctx *ctx,
72f87654 PE	130	unsigned long from,
	131	unsigned long to,
	132	unsigned long len)
	133	{
	134	}
05ce7724	135
70ccb92f	136	static inline bool userfaultfd_remove(struct vm_area_struct *vma,
d811914d MR	137	unsigned long start,
d811914d MR	138	unsigned long end)
05ce7724	139	{
70ccb92f	140	return true;
05ce7724	141	}
897ab3e0 MR	142
	143	static inline int userfaultfd_unmap_prep(struct vm_area_struct *vma,
	144	unsigned long start, unsigned long end,
	145	struct list_head *uf)
	146	{
	147	return 0;
	148	}
	149
	150	static inline void userfaultfd_unmap_complete(struct mm_struct *mm,
	151	struct list_head *uf)
	152	{
	153	}
ca49ca71	154
932b18e0 AA	155	#endif /* CONFIG_USERFAULTFD */
	156
	157	#endif /* _LINUX_USERFAULTFD_K_H */