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linux-next/include/linux/userfaultfd_k.h
Souptick Joarder 2b74030354 mm: Change return type int to vm_fault_t for fault handlers
Use new return type vm_fault_t for fault handler.  For now, this is just
documenting that the function returns a VM_FAULT value rather than an
errno.  Once all instances are converted, vm_fault_t will become a
distinct type.

Ref-> commit 1c8f422059 ("mm: change return type to vm_fault_t")

The aim is to change the return type of finish_fault() and
handle_mm_fault() to vm_fault_t type.  As part of that clean up return
type of all other recursively called functions have been changed to
vm_fault_t type.

The places from where handle_mm_fault() is getting invoked will be
change to vm_fault_t type but in a separate patch.

vmf_error() is the newly introduce inline function in 4.17-rc6.

[akpm@linux-foundation.org: don't shadow outer local `ret' in __do_huge_pmd_anonymous_page()]
Link: http://lkml.kernel.org/r/20180604171727.GA20279@jordon-HP-15-Notebook-PC
Signed-off-by: Souptick Joarder <jrdr.linux@gmail.com>
Reviewed-by: Matthew Wilcox <mawilcox@microsoft.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-23 18:48:44 -07:00

146 lines
3.6 KiB
C

/* 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 */