diff --git a/sys/compat/linuxkpi/common/include/linux/mm.h b/sys/compat/linuxkpi/common/include/linux/mm.h
--- a/sys/compat/linuxkpi/common/include/linux/mm.h
+++ b/sys/compat/linuxkpi/common/include/linux/mm.h
@@ -310,4 +310,6 @@
 
 #define PAGE_ALIGNED(p)	__is_aligned(p, PAGE_SIZE)
 
+void vma_set_file(struct vm_area_struct *vma, struct linux_file *file);
+
 #endif					/* _LINUXKPI_LINUX_MM_H_ */
diff --git a/sys/compat/linuxkpi/common/src/linux_compat.c b/sys/compat/linuxkpi/common/src/linux_compat.c
--- a/sys/compat/linuxkpi/common/src/linux_compat.c
+++ b/sys/compat/linuxkpi/common/src/linux_compat.c
@@ -833,6 +833,18 @@
 	return (0);
 }
 
+void
+vma_set_file(struct vm_area_struct *vma, struct linux_file *file)
+{
+	struct linux_file *tmp;
+
+	/* Changing an anonymous vma with this is illegal */
+	get_file(file);
+	tmp = vma->vm_file;
+	vma->vm_file = file;
+	fput(tmp);
+}
+
 static struct file_operations dummy_ldev_ops = {
 	/* XXXKIB */
 };