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