diff options
author | Andrea Arcangeli <aarcange@redhat.com> | 2015-05-14 19:31:01 +0200 |
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committer | Sasha Levin <sasha.levin@oracle.com> | 2015-05-18 06:28:56 -0400 |
commit | d615b32241ecae9b3f5b001acb24195693b7658f (patch) | |
tree | 867a794b8526c96ae248581c6170ec80d217b13b | |
parent | 02e446b1e9e61c3336864f7b9b0d27ca368a6518 (diff) | |
download | mm-next-d615b32241ecae9b3f5b001acb24195693b7658f.tar.gz |
userfaultfd: linux/userfaultfd_k.h
Kernel header defining the methods needed by the VM common code to
interact with the userfaultfd.
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
-rw-r--r-- | include/linux/userfaultfd_k.h | 79 |
1 files changed, 79 insertions, 0 deletions
diff --git a/include/linux/userfaultfd_k.h b/include/linux/userfaultfd_k.h new file mode 100644 index 00000000000000..e1e43609a179a3 --- /dev/null +++ b/include/linux/userfaultfd_k.h @@ -0,0 +1,79 @@ +/* + * 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_area_struct *vma, unsigned long address, + unsigned int flags, unsigned long reason); + +/* 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); +} + +#else /* CONFIG_USERFAULTFD */ + +/* mm helpers */ +static inline int handle_userfault(struct vm_area_struct *vma, + unsigned long address, + unsigned int flags, + 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; +} + +#endif /* CONFIG_USERFAULTFD */ + +#endif /* _LINUX_USERFAULTFD_K_H */ |