License cleanup: add SPDX GPL-2.0 license identifier to files with no license

Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.

By default all files without license information are under the default
license of the kernel, which is GPL version 2.

Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier.  The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.

This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.

How this work was done:

Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
 - file had no licensing information it it.
 - file was a */uapi/* one with no licensing information in it,
 - file was a */uapi/* one with existing licensing information,

Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.

The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne.  Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.

The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed.  Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.

Criteria used to select files for SPDX license identifier tagging was:
 - Files considered eligible had to be source code files.
 - Make and config files were included as candidates if they contained >5
   lines of source
 - File already had some variant of a license header in it (even if <5
   lines).

All documentation files were explicitly excluded.

The following heuristics were used to determine which SPDX license
identifiers to apply.

 - when both scanners couldn't find any license traces, file was
   considered to have no license information in it, and the top level
   COPYING file license applied.

   For non */uapi/* files that summary was:

   SPDX license identifier                            # files
   ---------------------------------------------------|-------
   GPL-2.0                                              11139

   and resulted in the first patch in this series.

   If that file was a */uapi/* path one, it was "GPL-2.0 WITH
   Linux-syscall-note" otherwise it was "GPL-2.0".  Results of that was:

   SPDX license identifier                            # files
   ---------------------------------------------------|-------
   GPL-2.0 WITH Linux-syscall-note                        930

   and resulted in the second patch in this series.

 - if a file had some form of licensing information in it, and was one
   of the */uapi/* ones, it was denoted with the Linux-syscall-note if
   any GPL family license was found in the file or had no licensing in
   it (per prior point).  Results summary:

   SPDX license identifier                            # files
   ---------------------------------------------------|------
   GPL-2.0 WITH Linux-syscall-note                       270
   GPL-2.0+ WITH Linux-syscall-note                      169
   ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause)    21
   ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause)    17
   LGPL-2.1+ WITH Linux-syscall-note                      15
   GPL-1.0+ WITH Linux-syscall-note                       14
   ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause)    5
   LGPL-2.0+ WITH Linux-syscall-note                       4
   LGPL-2.1 WITH Linux-syscall-note                        3
   ((GPL-2.0 WITH Linux-syscall-note) OR MIT)              3
   ((GPL-2.0 WITH Linux-syscall-note) AND MIT)             1

   and that resulted in the third patch in this series.

 - when the two scanners agreed on the detected license(s), that became
   the concluded license(s).

 - when there was disagreement between the two scanners (one detected a
   license but the other didn't, or they both detected different
   licenses) a manual inspection of the file occurred.

 - In most cases a manual inspection of the information in the file
   resulted in a clear resolution of the license that should apply (and
   which scanner probably needed to revisit its heuristics).

 - When it was not immediately clear, the license identifier was
   confirmed with lawyers working with the Linux Foundation.

 - If there was any question as to the appropriate license identifier,
   the file was flagged for further research and to be revisited later
   in time.

In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.

Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights.  The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.

Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.

In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.

Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
 - a full scancode scan run, collecting the matched texts, detected
   license ids and scores
 - reviewing anything where there was a license detected (about 500+
   files) to ensure that the applied SPDX license was correct
 - reviewing anything where there was no detection but the patch license
   was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
   SPDX license was correct

This produced a worksheet with 20 files needing minor correction.  This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.

These .csv files were then reviewed by Greg.  Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected.  This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.)  Finally Greg ran the script using the .csv files to
generate the patches.

Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

53 files changed, 53 insertions, 0 deletions

diff --git a/mm/Makefile b/mm/Makefile
index e3ac3aeb533b..4659b93cba43 100644
--- a/mm/Makefile
+++ b/mm/Makefile
@@ -1,3 +1,4 @@
+# SPDX-License-Identifier: GPL-2.0
 #
 # Makefile for the linux memory manager.
 #
diff --git a/mm/bootmem.c b/mm/bootmem.c
index 9fedb27c6451..6aef64254203 100644
--- a/mm/bootmem.c
+++ b/mm/bootmem.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 /*
  *  bootmem - A boot-time physical memory allocator and configurator
  *
diff --git a/mm/cma.h b/mm/cma.h
index 49861286279d..33c0b517733c 100644
--- a/mm/cma.h
+++ b/mm/cma.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #ifndef __MM_CMA_H__
 #define __MM_CMA_H__
 
diff --git a/mm/cma_debug.c b/mm/cma_debug.c
index c03ccbc405a0..275df8b5b22e 100644
--- a/mm/cma_debug.c
+++ b/mm/cma_debug.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 /*
  * CMA DebugFS Interface
  *
diff --git a/mm/compaction.c b/mm/compaction.c
index 03d31a875341..85395dc6eb13 100644
--- a/mm/compaction.c
+++ b/mm/compaction.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 /*
  * linux/mm/compaction.c
  *
diff --git a/mm/debug.c b/mm/debug.c
index 5715448ab0b5..6726bec731c9 100644
--- a/mm/debug.c
+++ b/mm/debug.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 /*
  * mm/debug.c
  *
diff --git a/mm/debug_page_ref.c b/mm/debug_page_ref.c
index 1aef3d562e52..f3b2c9d3ece2 100644
--- a/mm/debug_page_ref.c
+++ b/mm/debug_page_ref.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #include <linux/mm_types.h>
 #include <linux/tracepoint.h>
 
diff --git a/mm/early_ioremap.c b/mm/early_ioremap.c
index b1dd4a948fc0..d04ac1ec0559 100644
--- a/mm/early_ioremap.c
+++ b/mm/early_ioremap.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 /*
  * Provide common bits of early_ioremap() support for architectures needing
  * temporary mappings during boot before ioremap() is available.
diff --git a/mm/fadvise.c b/mm/fadvise.c
index 702f239cd6db..ec70d6e4b86d 100644
--- a/mm/fadvise.c
+++ b/mm/fadvise.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 /*
  * mm/fadvise.c
  *
diff --git a/mm/failslab.c b/mm/failslab.c
index b0fac98cd938..8087d976a809 100644
--- a/mm/failslab.c
+++ b/mm/failslab.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #include <linux/fault-inject.h>
 #include <linux/slab.h>
 #include <linux/mm.h>
diff --git a/mm/frame_vector.c b/mm/frame_vector.c
index 72ebec18629c..2f98df0d460e 100644
--- a/mm/frame_vector.c
+++ b/mm/frame_vector.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #include <linux/kernel.h>
 #include <linux/errno.h>
 #include <linux/err.h>
diff --git a/mm/highmem.c b/mm/highmem.c
index 50b4ca6787f0..59db3223a5d6 100644
--- a/mm/highmem.c
+++ b/mm/highmem.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 /*
  * High memory handling common code and variables.
  *
diff --git a/mm/init-mm.c b/mm/init-mm.c
index 975e49f00f34..f94d5d15ebc0 100644
--- a/mm/init-mm.c
+++ b/mm/init-mm.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #include <linux/mm_types.h>
 #include <linux/rbtree.h>
 #include <linux/rwsem.h>
diff --git a/mm/kasan/Makefile b/mm/kasan/Makefile
index 2976a9ee104f..3289db38bc87 100644
--- a/mm/kasan/Makefile
+++ b/mm/kasan/Makefile
@@ -1,3 +1,4 @@
+# SPDX-License-Identifier: GPL-2.0
 KASAN_SANITIZE := n
 UBSAN_SANITIZE_kasan.o := n
 KCOV_INSTRUMENT := n
diff --git a/mm/kasan/kasan.h b/mm/kasan/kasan.h
index 1229298cce64..c70851a9a6a4 100644
--- a/mm/kasan/kasan.h
+++ b/mm/kasan/kasan.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #ifndef __MM_KASAN_KASAN_H
 #define __MM_KASAN_KASAN_H
 
diff --git a/mm/khugepaged.c b/mm/khugepaged.c
index c01f177a1120..43cb3043311b 100644
--- a/mm/khugepaged.c
+++ b/mm/khugepaged.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 
 #include <linux/mm.h>
diff --git a/mm/kmemcheck.c b/mm/kmemcheck.c
index 2d5959c5f7c5..800d64b854ea 100644
--- a/mm/kmemcheck.c
+++ b/mm/kmemcheck.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #include <linux/gfp.h>
 #include <linux/mm_types.h>
 #include <linux/mm.h>
diff --git a/mm/madvise.c b/mm/madvise.c
index fd70d6aabc3e..375cf32087e4 100644
--- a/mm/madvise.c
+++ b/mm/madvise.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 /*
  *	linux/mm/madvise.c
  *
diff --git a/mm/mempool.c b/mm/mempool.c
index 1c0294858527..c4a23cdae3f0 100644
--- a/mm/mempool.c
+++ b/mm/mempool.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 /*
  *  linux/mm/mempool.c
  *
diff --git a/mm/memtest.c b/mm/memtest.c
index 8eaa4c3a5f65..f53ace709ccd 100644
--- a/mm/memtest.c
+++ b/mm/memtest.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #include <linux/kernel.h>
 #include <linux/types.h>
 #include <linux/init.h>
diff --git a/mm/migrate.c b/mm/migrate.c
index e00814ca390e..1236449b4777 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 /*
  * Memory Migration functionality - linux/mm/migrate.c
  *
diff --git a/mm/mincore.c b/mm/mincore.c
index c5687c45c326..fc37afe226e6 100644
--- a/mm/mincore.c
+++ b/mm/mincore.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 /*
  *	linux/mm/mincore.c
  *
diff --git a/mm/mlock.c b/mm/mlock.c
index dfc6f1912176..46af369c13e5 100644
--- a/mm/mlock.c
+++ b/mm/mlock.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 /*
  *	linux/mm/mlock.c
  *
diff --git a/mm/mmzone.c b/mm/mmzone.c
index a51c0a67ea3d..4686fdc23bb9 100644
--- a/mm/mmzone.c
+++ b/mm/mmzone.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 /*
  * linux/mm/mmzone.c
  *
diff --git a/mm/mprotect.c b/mm/mprotect.c
index 6d3e2f082290..ec39f730a0bf 100644
--- a/mm/mprotect.c
+++ b/mm/mprotect.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 /*
  *  mm/mprotect.c
  *
diff --git a/mm/mremap.c b/mm/mremap.c
index cfec004c4ff9..049470aa1e3e 100644
--- a/mm/mremap.c
+++ b/mm/mremap.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 /*
  *	mm/mremap.c
  *
diff --git a/mm/msync.c b/mm/msync.c
index 24e612fefa04..ef30a429623a 100644
--- a/mm/msync.c
+++ b/mm/msync.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 /*
  *	linux/mm/msync.c
  *
diff --git a/mm/nobootmem.c b/mm/nobootmem.c
index 3637809a18d0..9b02fda0886b 100644
--- a/mm/nobootmem.c
+++ b/mm/nobootmem.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 /*
  *  bootmem - A boot-time physical memory allocator and configurator
  *
diff --git a/mm/page_counter.c b/mm/page_counter.c
index 7c6a63d2c27f..2a8df3ad60a4 100644
--- a/mm/page_counter.c
+++ b/mm/page_counter.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 /*
  * Lockless hierarchical page accounting & limiting
  *
diff --git a/mm/page_ext.c b/mm/page_ext.c
index 32f18911deda..4f0367d472c4 100644
--- a/mm/page_ext.c
+++ b/mm/page_ext.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #include <linux/mm.h>
 #include <linux/mmzone.h>
 #include <linux/bootmem.h>
diff --git a/mm/page_idle.c b/mm/page_idle.c
index 4bd03a8d809e..0a49374e6931 100644
--- a/mm/page_idle.c
+++ b/mm/page_idle.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #include <linux/init.h>
 #include <linux/bootmem.h>
 #include <linux/fs.h>
diff --git a/mm/page_io.c b/mm/page_io.c
index 21502d341a67..5d882de3fbfd 100644
--- a/mm/page_io.c
+++ b/mm/page_io.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 /*
  *  linux/mm/page_io.c
  *
diff --git a/mm/page_isolation.c b/mm/page_isolation.c
index 757410d9f758..44f213935bf6 100644
--- a/mm/page_isolation.c
+++ b/mm/page_isolation.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 /*
  * linux/mm/page_isolation.c
  */
diff --git a/mm/page_owner.c b/mm/page_owner.c
index 57abca62d4db..4f44b95b9d1e 100644
--- a/mm/page_owner.c
+++ b/mm/page_owner.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #include <linux/debugfs.h>
 #include <linux/mm.h>
 #include <linux/slab.h>
diff --git a/mm/page_poison.c b/mm/page_poison.c
index be19e989ccff..e83fd44867de 100644
--- a/mm/page_poison.c
+++ b/mm/page_poison.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #include <linux/kernel.h>
 #include <linux/string.h>
 #include <linux/mm.h>
diff --git a/mm/page_vma_mapped.c b/mm/page_vma_mapped.c
index 53afbb919a1c..d22b84310f6d 100644
--- a/mm/page_vma_mapped.c
+++ b/mm/page_vma_mapped.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #include <linux/mm.h>
 #include <linux/rmap.h>
 #include <linux/hugetlb.h>
diff --git a/mm/pagewalk.c b/mm/pagewalk.c
index 1a4197965415..8bd4afa83cb8 100644
--- a/mm/pagewalk.c
+++ b/mm/pagewalk.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #include <linux/mm.h>
 #include <linux/highmem.h>
 #include <linux/sched.h>
diff --git a/mm/percpu-internal.h b/mm/percpu-internal.h
index 7065faf74b46..b1739dc06b73 100644
--- a/mm/percpu-internal.h
+++ b/mm/percpu-internal.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #ifndef _MM_PERCPU_INTERNAL_H
 #define _MM_PERCPU_INTERNAL_H
 
diff --git a/mm/pgtable-generic.c b/mm/pgtable-generic.c
index 1175f6a24fdb..1e4ee763c190 100644
--- a/mm/pgtable-generic.c
+++ b/mm/pgtable-generic.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 /*
  *  mm/pgtable-generic.c
  *
diff --git a/mm/quicklist.c b/mm/quicklist.c
index daf6ff6e199a..5e98ac78e410 100644
--- a/mm/quicklist.c
+++ b/mm/quicklist.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 /*
  * Quicklist support.
  *
diff --git a/mm/slab.c b/mm/slab.c
index 04dec48c3ed7..b7095884fd93 100644
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 /*
  * linux/mm/slab.c
  * Written by Mark Hemment, 1996/97.
diff --git a/mm/slab.h b/mm/slab.h
index 073362816acc..028cdc7df67e 100644
--- a/mm/slab.h
+++ b/mm/slab.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #ifndef MM_SLAB_H
 #define MM_SLAB_H
 /*
diff --git a/mm/slab_common.c b/mm/slab_common.c
index 80164599ca5d..0d7fe71ff5e4 100644
--- a/mm/slab_common.c
+++ b/mm/slab_common.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 /*
  * Slab allocator functions that are independent of the allocator strategy
  *
diff --git a/mm/slob.c b/mm/slob.c
index a8bd6fa11a66..10249160b693 100644
--- a/mm/slob.c
+++ b/mm/slob.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 /*
  * SLOB Allocator: Simple List Of Blocks
  *
diff --git a/mm/slub.c b/mm/slub.c
index 163352c537ab..1efbb8123037 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 /*
  * SLUB: A slab allocator that limits cache line use instead of queuing
  * objects in per cpu and per node lists.
diff --git a/mm/sparse-vmemmap.c b/mm/sparse-vmemmap.c
index d1a39b8051e0..478ce6d4a2c4 100644
--- a/mm/sparse-vmemmap.c
+++ b/mm/sparse-vmemmap.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 /*
  * Virtual Memory Map support
  *
diff --git a/mm/sparse.c b/mm/sparse.c
index 83b3bf6461af..4900707ae146 100644
--- a/mm/sparse.c
+++ b/mm/sparse.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 /*
  * sparse memory mappings.
  */
diff --git a/mm/swap_cgroup.c b/mm/swap_cgroup.c
index fcd2740f4ed7..45affaef3bc6 100644
--- a/mm/swap_cgroup.c
+++ b/mm/swap_cgroup.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #include <linux/swap_cgroup.h>
 #include <linux/vmalloc.h>
 #include <linux/mm.h>
diff --git a/mm/swap_slots.c b/mm/swap_slots.c
index 13a174006b91..d81cfc5a43d5 100644
--- a/mm/swap_slots.c
+++ b/mm/swap_slots.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 /*
  * Manage cache of swap slots to be used for and returned from
  * swap.
diff --git a/mm/swap_state.c b/mm/swap_state.c
index 05b6803f0cce..326439428daf 100644
--- a/mm/swap_state.c
+++ b/mm/swap_state.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 /*
  *  linux/mm/swap_state.c
  *
diff --git a/mm/vmacache.c b/mm/vmacache.c
index 7ffa0ee341b5..db7596eb6132 100644
--- a/mm/vmacache.c
+++ b/mm/vmacache.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 /*
  * Copyright (C) 2014 Davidlohr Bueso.
  */
diff --git a/mm/vmscan.c b/mm/vmscan.c
index 13d711dd8776..eb2f0315b8c0 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 /*
  *  linux/mm/vmscan.c
  *
diff --git a/mm/workingset.c b/mm/workingset.c
index 7119cd745ace..b997c9de28f6 100644
--- a/mm/workingset.c
+++ b/mm/workingset.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 /*
  * Workingset detection
  *