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>

26 files changed, 26 insertions, 0 deletions

diff --git a/arch/arm/mm/Kconfig b/arch/arm/mm/Kconfig
index 60cdfdc151aa..fd9077a74fce 100644
--- a/arch/arm/mm/Kconfig
+++ b/arch/arm/mm/Kconfig
@@ -1,3 +1,4 @@
+# SPDX-License-Identifier: GPL-2.0
 comment "Processor Type"
 
 # Select CPU types depending on the architecture selected.  This selects
diff --git a/arch/arm/mm/Makefile b/arch/arm/mm/Makefile
index 950d19babb5f..f353ee569f6b 100644
--- a/arch/arm/mm/Makefile
+++ b/arch/arm/mm/Makefile
@@ -1,3 +1,4 @@
+# SPDX-License-Identifier: GPL-2.0
 #
 # Makefile for the linux arm-specific parts of the memory manager.
 #
diff --git a/arch/arm/mm/abort-ev4.S b/arch/arm/mm/abort-ev4.S
index b3b31e30cadd..a10bcb89594d 100644
--- a/arch/arm/mm/abort-ev4.S
+++ b/arch/arm/mm/abort-ev4.S
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #include <linux/linkage.h>
 #include <asm/assembler.h>
 /*
diff --git a/arch/arm/mm/abort-ev4t.S b/arch/arm/mm/abort-ev4t.S
index 9da704e7b86e..14743a2f6997 100644
--- a/arch/arm/mm/abort-ev4t.S
+++ b/arch/arm/mm/abort-ev4t.S
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #include <linux/linkage.h>
 #include <asm/assembler.h>
 #include "abort-macro.S"
diff --git a/arch/arm/mm/abort-ev5t.S b/arch/arm/mm/abort-ev5t.S
index a6a381a6caa5..98c523118820 100644
--- a/arch/arm/mm/abort-ev5t.S
+++ b/arch/arm/mm/abort-ev5t.S
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #include <linux/linkage.h>
 #include <asm/assembler.h>
 #include "abort-macro.S"
diff --git a/arch/arm/mm/abort-ev5tj.S b/arch/arm/mm/abort-ev5tj.S
index 00ab011bef58..fec72f4fbaf5 100644
--- a/arch/arm/mm/abort-ev5tj.S
+++ b/arch/arm/mm/abort-ev5tj.S
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #include <linux/linkage.h>
 #include <asm/assembler.h>
 #include "abort-macro.S"
diff --git a/arch/arm/mm/abort-ev6.S b/arch/arm/mm/abort-ev6.S
index 8801a15aa105..c58bf8b43fea 100644
--- a/arch/arm/mm/abort-ev6.S
+++ b/arch/arm/mm/abort-ev6.S
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #include <linux/linkage.h>
 #include <asm/assembler.h>
 #include "abort-macro.S"
diff --git a/arch/arm/mm/abort-ev7.S b/arch/arm/mm/abort-ev7.S
index e8d0e08c227f..f7cc5d68444b 100644
--- a/arch/arm/mm/abort-ev7.S
+++ b/arch/arm/mm/abort-ev7.S
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #include <linux/linkage.h>
 #include <asm/assembler.h>
 /*
diff --git a/arch/arm/mm/abort-lv4t.S b/arch/arm/mm/abort-lv4t.S
index 4cdfab31a0b6..fbd60a120f66 100644
--- a/arch/arm/mm/abort-lv4t.S
+++ b/arch/arm/mm/abort-lv4t.S
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #include <linux/linkage.h>
 #include <asm/assembler.h>
 /*
diff --git a/arch/arm/mm/abort-macro.S b/arch/arm/mm/abort-macro.S
index 4509bee4e081..bacf53fd0b70 100644
--- a/arch/arm/mm/abort-macro.S
+++ b/arch/arm/mm/abort-macro.S
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 /*
  * The ARM LDRD and Thumb LDRSB instructions use bit 20/11 (ARM/Thumb)
  * differently than every other instruction, so it is set to 0 (write)
diff --git a/arch/arm/mm/abort-nommu.S b/arch/arm/mm/abort-nommu.S
index 119cb479c2ab..6e2366a26321 100644
--- a/arch/arm/mm/abort-nommu.S
+++ b/arch/arm/mm/abort-nommu.S
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #include <linux/linkage.h>
 #include <asm/assembler.h>
 /*
diff --git a/arch/arm/mm/dma.h b/arch/arm/mm/dma.h
index 70ea6852f94e..aaef64b7f177 100644
--- a/arch/arm/mm/dma.h
+++ b/arch/arm/mm/dma.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #ifndef DMA_H
 #define DMA_H
 
diff --git a/arch/arm/mm/extable.c b/arch/arm/mm/extable.c
index f436f7439e46..fc33564597b8 100644
--- a/arch/arm/mm/extable.c
+++ b/arch/arm/mm/extable.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 /*
  *  linux/arch/arm/mm/extable.c
  */
diff --git a/arch/arm/mm/fault.h b/arch/arm/mm/fault.h
index afc1f84e763b..c063708fa503 100644
--- a/arch/arm/mm/fault.h
+++ b/arch/arm/mm/fault.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #ifndef __ARCH_ARM_FAULT_H
 #define __ARCH_ARM_FAULT_H
 
diff --git a/arch/arm/mm/fsr-2level.c b/arch/arm/mm/fsr-2level.c
index 18ca74c0f341..f2be95197265 100644
--- a/arch/arm/mm/fsr-2level.c
+++ b/arch/arm/mm/fsr-2level.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 static struct fsr_info fsr_info[] = {
 	/*
 	 * The following are the standard ARMv3 and ARMv4 aborts.  ARMv5
diff --git a/arch/arm/mm/fsr-3level.c b/arch/arm/mm/fsr-3level.c
index ab4409a2307e..d0ae2963656a 100644
--- a/arch/arm/mm/fsr-3level.c
+++ b/arch/arm/mm/fsr-3level.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 static struct fsr_info fsr_info[] = {
 	{ do_bad,		SIGBUS,  0,		"unknown 0"			},
 	{ do_bad,		SIGBUS,  0,		"unknown 1"			},
diff --git a/arch/arm/mm/idmap.c b/arch/arm/mm/idmap.c
index 3e511bec69b8..10bfba85eb96 100644
--- a/arch/arm/mm/idmap.c
+++ b/arch/arm/mm/idmap.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #include <linux/module.h>
 #include <linux/kernel.h>
 #include <linux/slab.h>
diff --git a/arch/arm/mm/iomap.c b/arch/arm/mm/iomap.c
index 4614208369f1..091ddc56827e 100644
--- a/arch/arm/mm/iomap.c
+++ b/arch/arm/mm/iomap.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 /*
  *  linux/arch/arm/mm/iomap.c
  *
diff --git a/arch/arm/mm/l2c-l2x0-resume.S b/arch/arm/mm/l2c-l2x0-resume.S
index fda415e4ca8f..fc01f1b18523 100644
--- a/arch/arm/mm/l2c-l2x0-resume.S
+++ b/arch/arm/mm/l2c-l2x0-resume.S
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 /*
  * L2C-310 early resume code.  This can be used by platforms to restore
  * the settings of their L2 cache controller before restoring the
diff --git a/arch/arm/mm/mm.h b/arch/arm/mm/mm.h
index ce727d47275c..6b045c6653ea 100644
--- a/arch/arm/mm/mm.h
+++ b/arch/arm/mm/mm.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #ifdef CONFIG_MMU
 #include <linux/list.h>
 #include <linux/vmalloc.h>
diff --git a/arch/arm/mm/mmap.c b/arch/arm/mm/mmap.c
index f0701d8d24df..eb1de66517d5 100644
--- a/arch/arm/mm/mmap.c
+++ b/arch/arm/mm/mmap.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 /*
  *  linux/arch/arm/mm/mmap.c
  */
diff --git a/arch/arm/mm/pabort-legacy.S b/arch/arm/mm/pabort-legacy.S
index 8bbff025269a..b2ffce420106 100644
--- a/arch/arm/mm/pabort-legacy.S
+++ b/arch/arm/mm/pabort-legacy.S
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #include <linux/linkage.h>
 #include <asm/assembler.h>
 
diff --git a/arch/arm/mm/pabort-v6.S b/arch/arm/mm/pabort-v6.S
index 9627646ce783..8686265dc941 100644
--- a/arch/arm/mm/pabort-v6.S
+++ b/arch/arm/mm/pabort-v6.S
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #include <linux/linkage.h>
 #include <asm/assembler.h>
 
diff --git a/arch/arm/mm/pabort-v7.S b/arch/arm/mm/pabort-v7.S
index 875761f44f3b..9c70b1a21dc9 100644
--- a/arch/arm/mm/pabort-v7.S
+++ b/arch/arm/mm/pabort-v7.S
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #include <linux/linkage.h>
 #include <asm/assembler.h>
 
diff --git a/arch/arm/mm/physaddr.c b/arch/arm/mm/physaddr.c
index 02e60f495608..cf75819e4c13 100644
--- a/arch/arm/mm/physaddr.c
+++ b/arch/arm/mm/physaddr.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #include <linux/bug.h>
 #include <linux/export.h>
 #include <linux/types.h>
diff --git a/arch/arm/mm/proc-macros.S b/arch/arm/mm/proc-macros.S
index f944836da8a2..f10e31d0730a 100644
--- a/arch/arm/mm/proc-macros.S
+++ b/arch/arm/mm/proc-macros.S
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 /*
  * We need constants.h for:
  *  VMA_VM_MM