diff --git a/fs/file.c b/fs/file.c
index 7ffd6e9..6d6f185 100644
--- a/fs/file.c
+++ b/fs/file.c
@@ -727,7 +727,7 @@ struct file *fget_raw(unsigned int fd)
  * The fput_needed flag returned by fget_light should be passed to the
  * corresponding fput_light.
  */
-static unsigned long __fget_light(unsigned int fd, fmode_t mask)
+static taggedptr_t __fget_light(unsigned int fd, fmode_t mask)
 {
 	struct files_struct *files = current->files;
 	struct file *file;
@@ -736,33 +736,34 @@ static unsigned long __fget_light(unsigned int fd, fmode_t mask)
 		file = __fcheck_files(files, fd);
 		if (!file || unlikely(file->f_mode & mask))
 			return 0;
-		return (unsigned long)file;
+		return taggedptr_fold(file, 0);
 	} else {
 		file = __fget(fd, mask);
 		if (!file)
 			return 0;
-		return FDPUT_FPUT | (unsigned long)file;
+		return taggedptr_fold(file, FDPUT_FPUT);
 	}
 }
-unsigned long __fdget(unsigned int fd)
+
+taggedptr_t __fdget(unsigned int fd)
 {
 	return __fget_light(fd, FMODE_PATH);
 }
 EXPORT_SYMBOL(__fdget);
 
-unsigned long __fdget_raw(unsigned int fd)
+taggedptr_t __fdget_raw(unsigned int fd)
 {
 	return __fget_light(fd, 0);
 }
 
-unsigned long __fdget_pos(unsigned int fd)
+taggedptr_t __fdget_pos(unsigned int fd)
 {
-	unsigned long v = __fdget(fd);
-	struct file *file = (struct file *)(v & ~3);
+	taggedptr_t v = __fdget(fd);
+	struct file *file = taggedptr_unfold_ptr(v);
 
 	if (file && (file->f_mode & FMODE_ATOMIC_POS)) {
 		if (file_count(file) > 1) {
-			v |= FDPUT_POS_UNLOCK;
+			taggedptr_set_tags(v, FDPUT_POS_UNLOCK);
 			mutex_lock(&file->f_pos_lock);
 		}
 	}
diff --git a/include/linux/file.h b/include/linux/file.h
index 279720d..af81f68 100644
--- a/include/linux/file.h
+++ b/include/linux/file.h
@@ -9,6 +9,7 @@
 #include <linux/compiler.h>
 #include <linux/types.h>
 #include <linux/posix_types.h>
+#include <linux/taggedptr.h>
 
 struct file;
 
@@ -42,9 +43,9 @@ static inline void fdput(struct fd fd)
 
 extern struct file *fget(unsigned int fd);
 extern struct file *fget_raw(unsigned int fd);
-extern unsigned long __fdget(unsigned int fd);
-extern unsigned long __fdget_raw(unsigned int fd);
-extern unsigned long __fdget_pos(unsigned int fd);
+extern taggedptr_t __fdget(unsigned int fd);
+extern taggedptr_t __fdget_raw(unsigned int fd);
+extern taggedptr_t __fdget_pos(unsigned int fd);
 extern void __f_unlock_pos(struct file *);
 
 static inline struct fd __to_fd(unsigned long v)
diff --git a/include/linux/taggedptr.h b/include/linux/taggedptr.h
new file mode 100644
index 0000000..1805394
--- /dev/null
+++ b/include/linux/taggedptr.h
@@ -0,0 +1,76 @@
+/* SPDX-License-Identifier: GPL-2.0
+ *
+ * Tagged pointer implementation
+ *
+ * Copyright (C) 2018 Gao Xiang <gaoxiang25@huawei.com>
+ */
+#ifndef _LINUX_TAGGEDPTR_H
+#define _LINUX_TAGGEDPTR_H
+
+#include <linux/types.h>
+#include <linux/build_bug.h>
+
+/*
+ * mark these special integers as another type
+ * in order to highlight the tagged pointer usage.
+ */
+typedef uintptr_t	taggedptr_t;
+
+/*
+ * generally for all architectures, the last 2 bits of
+ * pointer can be used safely
+ */
+#ifndef TAGGEDPTR_TAGS_BITS
+#define TAGGEDPTR_TAGS_BITS	2
+#endif
+
+#define TAGGEDPTR_TAGS_MASK	((1 << TAGGEDPTR_TAGS_BITS) - 1)
+
+extern void __compiletime_error("bad taggedptr tags")
+	__bad_taggedptr_tags(void);
+
+/* encode the tagged pointer */
+static inline taggedptr_t taggedptr_fold(void *ptr, unsigned int tags)
+{
+	if (__builtin_constant_p(tags) && (tags & ~TAGGEDPTR_TAGS_MASK))
+		__bad_taggedptr_tags();
+
+	return (taggedptr_t)ptr | tags;
+}
+
+static inline void *taggedptr_unfold_ptr(taggedptr_t tptr)
+{
+	return (void *)(tptr & ~TAGGEDPTR_TAGS_MASK);
+}
+
+static inline unsigned int taggedptr_unfold_tags(taggedptr_t tptr)
+{
+	return tptr & TAGGEDPTR_TAGS_MASK;
+}
+
+static inline taggedptr_t taggedptr_replace_tags(taggedptr_t tptr,
+						 unsigned int tags)
+{
+	return taggedptr_fold(taggedptr_unfold_ptr(tptr), tags);
+}
+
+static inline taggedptr_t taggedptr_set_tags(taggedptr_t tptr,
+					     unsigned int tags)
+{
+	if (__builtin_constant_p(tags) && (tags & ~TAGGEDPTR_TAGS_MASK))
+		__bad_taggedptr_tags();
+
+	return tptr |= tags;
+}
+
+static inline taggedptr_t taggedptr_clear_tags(taggedptr_t tptr,
+					       unsigned int tags)
+{
+	if (__builtin_constant_p(tags) && (tags & ~TAGGEDPTR_TAGS_MASK))
+		__bad_taggedptr_tags();
+
+	return tptr &= ~tags;
+}
+
+#endif
+
