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>

22 files changed, 22 insertions, 0 deletions

diff --git a/drivers/char/Kconfig b/drivers/char/Kconfig
index 623714344600..c28dca0c613d 100644
--- a/drivers/char/Kconfig
+++ b/drivers/char/Kconfig
@@ -1,3 +1,4 @@
+# SPDX-License-Identifier: GPL-2.0
 #
 # Character device configuration
 #
diff --git a/drivers/char/Makefile b/drivers/char/Makefile
index 53e33720818c..7dc3abe66464 100644
--- a/drivers/char/Makefile
+++ b/drivers/char/Makefile
@@ -1,3 +1,4 @@
+# SPDX-License-Identifier: GPL-2.0
 #
 # Makefile for the kernel character device drivers.
 #
diff --git a/drivers/char/agp/Kconfig b/drivers/char/agp/Kconfig
index c528f96ee204..6231714ef3c8 100644
--- a/drivers/char/agp/Kconfig
+++ b/drivers/char/agp/Kconfig
@@ -1,3 +1,4 @@
+# SPDX-License-Identifier: GPL-2.0
 menuconfig AGP
 	tristate "/dev/agpgart (AGP Support)"
 	depends on ALPHA || IA64 || PARISC || PPC || X86
diff --git a/drivers/char/agp/Makefile b/drivers/char/agp/Makefile
index 604489bcdbf9..4a786ffd9dee 100644
--- a/drivers/char/agp/Makefile
+++ b/drivers/char/agp/Makefile
@@ -1,3 +1,4 @@
+# SPDX-License-Identifier: GPL-2.0
 agpgart-y := backend.o frontend.o generic.o isoch.o
 
 agpgart-$(CONFIG_COMPAT)	+= compat_ioctl.o
diff --git a/drivers/char/agp/intel-agp.h b/drivers/char/agp/intel-agp.h
index fda073dcd967..164bf651953f 100644
--- a/drivers/char/agp/intel-agp.h
+++ b/drivers/char/agp/intel-agp.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 /*
  * Common Intel AGPGART and GTT definitions.
  */
diff --git a/drivers/char/agp/isoch.c b/drivers/char/agp/isoch.c
index c73385cc4b8a..fc8e1bc3347d 100644
--- a/drivers/char/agp/isoch.c
+++ b/drivers/char/agp/isoch.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 /*
  * Setup routines for AGP 3.5 compliant bridges.
  */
diff --git a/drivers/char/applicom.h b/drivers/char/applicom.h
index 35530b3d9bd6..282e08f159d5 100644
--- a/drivers/char/applicom.h
+++ b/drivers/char/applicom.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 /* $Id: applicom.h,v 1.2 1999/08/28 15:09:49 dwmw2 Exp $ */
 
 
diff --git a/drivers/char/ds1302.c b/drivers/char/ds1302.c
index c614a56e68cc..8e16ad5d6d89 100644
--- a/drivers/char/ds1302.c
+++ b/drivers/char/ds1302.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 /*!***************************************************************************
 *!
 *! FILE NAME  : ds1302.c
diff --git a/drivers/char/hw_random/Makefile b/drivers/char/hw_random/Makefile
index 39a67defac67..f3728d008fff 100644
--- a/drivers/char/hw_random/Makefile
+++ b/drivers/char/hw_random/Makefile
@@ -1,3 +1,4 @@
+# SPDX-License-Identifier: GPL-2.0
 #
 # Makefile for HW Random Number Generator (RNG) device drivers.
 #
diff --git a/drivers/char/hw_random/n2-asm.S b/drivers/char/hw_random/n2-asm.S
index 9b6eb5cd59f6..c205df43d5ae 100644
--- a/drivers/char/hw_random/n2-asm.S
+++ b/drivers/char/hw_random/n2-asm.S
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 /* n2-asm.S: Niagara2 RNG hypervisor call assembler.
  *
  * Copyright (C) 2008 David S. Miller <davem@davemloft.net>
diff --git a/drivers/char/hw_random/n2rng.h b/drivers/char/hw_random/n2rng.h
index 6bad6cc634e8..9a870f5dc371 100644
--- a/drivers/char/hw_random/n2rng.h
+++ b/drivers/char/hw_random/n2rng.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 /* n2rng.h: Niagara2 RNG defines.
  *
  * Copyright (C) 2008 David S. Miller <davem@davemloft.net>
diff --git a/drivers/char/ipmi/Makefile b/drivers/char/ipmi/Makefile
index eefb0b301e83..43b7d86cc5f2 100644
--- a/drivers/char/ipmi/Makefile
+++ b/drivers/char/ipmi/Makefile
@@ -1,3 +1,4 @@
+# SPDX-License-Identifier: GPL-2.0
 #
 # Makefile for the ipmi drivers.
 #
diff --git a/drivers/char/ipmi/ipmi_dmi.c b/drivers/char/ipmi/ipmi_dmi.c
index 2a84401dea05..2059f79d669a 100644
--- a/drivers/char/ipmi/ipmi_dmi.c
+++ b/drivers/char/ipmi/ipmi_dmi.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 /*
  * A hack to create a platform device from a DMI entry.  This will
  * allow autoloading of the IPMI drive based on SMBIOS entries.
diff --git a/drivers/char/ipmi/ipmi_dmi.h b/drivers/char/ipmi/ipmi_dmi.h
index 0a1afe5ceb1e..ea990a8e3b09 100644
--- a/drivers/char/ipmi/ipmi_dmi.h
+++ b/drivers/char/ipmi/ipmi_dmi.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 /*
  * DMI defines for use by IPMI
  */
diff --git a/drivers/char/mem.c b/drivers/char/mem.c
index 593a8818aca9..970e1242a282 100644
--- a/drivers/char/mem.c
+++ b/drivers/char/mem.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 /*
  *  linux/drivers/char/mem.c
  *
diff --git a/drivers/char/misc.c b/drivers/char/misc.c
index c9cd1ea6844a..1bb9e7cc82e3 100644
--- a/drivers/char/misc.c
+++ b/drivers/char/misc.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 /*
  * linux/drivers/char/misc.c
  *
diff --git a/drivers/char/nwbutton.h b/drivers/char/nwbutton.h
index c3ebc16ce8a7..abee3ca74801 100644
--- a/drivers/char/nwbutton.h
+++ b/drivers/char/nwbutton.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #ifndef __NWBUTTON_H
 #define __NWBUTTON_H
 
diff --git a/drivers/char/pcmcia/cm4040_cs.h b/drivers/char/pcmcia/cm4040_cs.h
index 9a8b805c5095..e2ffff995d51 100644
--- a/drivers/char/pcmcia/cm4040_cs.h
+++ b/drivers/char/pcmcia/cm4040_cs.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #ifndef	_CM4040_H_
 #define	_CM4040_H_
 
diff --git a/drivers/char/tpm/Makefile b/drivers/char/tpm/Makefile
index 23681f01f95a..34b4bcf46f43 100644
--- a/drivers/char/tpm/Makefile
+++ b/drivers/char/tpm/Makefile
@@ -1,3 +1,4 @@
+# SPDX-License-Identifier: GPL-2.0
 #
 # Makefile for the kernel tpm device drivers.
 #
diff --git a/drivers/char/tpm/st33zp24/Makefile b/drivers/char/tpm/st33zp24/Makefile
index 74a722e5e068..649e41107de9 100644
--- a/drivers/char/tpm/st33zp24/Makefile
+++ b/drivers/char/tpm/st33zp24/Makefile
@@ -1,3 +1,4 @@
+# SPDX-License-Identifier: GPL-2.0
 #
 # Makefile for ST33ZP24 TPM 1.2 driver
 #
diff --git a/drivers/char/tpm/tpm-dev.h b/drivers/char/tpm/tpm-dev.h
index ff15cf719bad..ba3b6f9dacf7 100644
--- a/drivers/char/tpm/tpm-dev.h
+++ b/drivers/char/tpm/tpm-dev.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #ifndef _TPM_DEV_H
 #define _TPM_DEV_H
 
diff --git a/drivers/char/tpm/tpm_eventlog.h b/drivers/char/tpm/tpm_eventlog.h
index b4b549559203..204466cc4d05 100644
--- a/drivers/char/tpm/tpm_eventlog.h
+++ b/drivers/char/tpm/tpm_eventlog.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 
 #ifndef __TPM_EVENTLOG_H__
 #define __TPM_EVENTLOG_H__