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authorAndrea Arcangeli <aarcange@redhat.com>2015-09-04 15:46:10 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2015-09-04 16:54:41 -0700
commit932b18e0aec65acb089f4bd8761ee85e70f8eb6a (patch)
tree3c13a23c34e9d1b4faac767806d2944bb50329ec /include
parent1038628d80e96e3a086189172d9be8eb85ecfabf (diff)
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> Acked-by: Pavel Emelyanov <xemul@parallels.com> Cc: Sanidhya Kashyap <sanidhya.gatech@gmail.com> Cc: zhang.zhanghailiang@huawei.com Cc: "Kirill A. Shutemov" <kirill@shutemov.name> Cc: Andres Lagar-Cavilla <andreslc@google.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Rik van Riel <riel@redhat.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Hugh Dickins <hughd@google.com> Cc: Peter Feiner <pfeiner@google.com> Cc: "Dr. David Alan Gilbert" <dgilbert@redhat.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: "Huangpeng (Peter)" <peter.huangpeng@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include')
-rw-r--r--include/linux/userfaultfd_k.h79
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 000000000000..e1e43609a179
--- /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 */