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-rw-r--r--kernel/include/linux/userfaultfd_k.h85
1 files changed, 85 insertions, 0 deletions
diff --git a/kernel/include/linux/userfaultfd_k.h b/kernel/include/linux/userfaultfd_k.h
new file mode 100644
index 000000000..587480ad4
--- /dev/null
+++ b/kernel/include/linux/userfaultfd_k.h
@@ -0,0 +1,85 @@
+/*
+ * 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);
+
+extern ssize_t mcopy_atomic(struct mm_struct *dst_mm, unsigned long dst_start,
+ unsigned long src_start, unsigned long len);
+extern ssize_t mfill_zeropage(struct mm_struct *dst_mm,
+ unsigned long dst_start,
+ unsigned long len);
+
+/* 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 */