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>

29 files changed, 29 insertions, 0 deletions

diff --git a/sound/usb/Makefile b/sound/usb/Makefile
index 42cb33b94f6a..05440e2df8d9 100644
--- a/sound/usb/Makefile
+++ b/sound/usb/Makefile
@@ -1,3 +1,4 @@
+# SPDX-License-Identifier: GPL-2.0
 #
 # Makefile for ALSA
 #
diff --git a/sound/usb/caiaq/audio.h b/sound/usb/caiaq/audio.h
index bdf155300a8a..869bf6264d6a 100644
--- a/sound/usb/caiaq/audio.h
+++ b/sound/usb/caiaq/audio.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #ifndef CAIAQ_AUDIO_H
 #define CAIAQ_AUDIO_H
 
diff --git a/sound/usb/caiaq/control.h b/sound/usb/caiaq/control.h
index 501c4883aef6..cb204fd45858 100644
--- a/sound/usb/caiaq/control.h
+++ b/sound/usb/caiaq/control.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #ifndef CAIAQ_CONTROL_H
 #define CAIAQ_CONTROL_H
 
diff --git a/sound/usb/caiaq/device.h b/sound/usb/caiaq/device.h
index ab0f7520a99b..50fea085765b 100644
--- a/sound/usb/caiaq/device.h
+++ b/sound/usb/caiaq/device.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #ifndef CAIAQ_DEVICE_H
 #define CAIAQ_DEVICE_H
 
diff --git a/sound/usb/caiaq/input.h b/sound/usb/caiaq/input.h
index 6014e2713a60..c42891e7be88 100644
--- a/sound/usb/caiaq/input.h
+++ b/sound/usb/caiaq/input.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #ifndef CAIAQ_INPUT_H
 #define CAIAQ_INPUT_H
 
diff --git a/sound/usb/caiaq/midi.h b/sound/usb/caiaq/midi.h
index 60bf3442b283..a6ae0c22484d 100644
--- a/sound/usb/caiaq/midi.h
+++ b/sound/usb/caiaq/midi.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #ifndef CAIAQ_MIDI_H
 #define CAIAQ_MIDI_H
 
diff --git a/sound/usb/card.h b/sound/usb/card.h
index 111b0f009afa..ed87cc83eb47 100644
--- a/sound/usb/card.h
+++ b/sound/usb/card.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #ifndef __USBAUDIO_CARD_H
 #define __USBAUDIO_CARD_H
 
diff --git a/sound/usb/clock.h b/sound/usb/clock.h
index d592e4a29856..87557cae1a0b 100644
--- a/sound/usb/clock.h
+++ b/sound/usb/clock.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #ifndef __USBAUDIO_CLOCK_H
 #define __USBAUDIO_CLOCK_H
 
diff --git a/sound/usb/debug.h b/sound/usb/debug.h
index 58030176f008..7dd983c35001 100644
--- a/sound/usb/debug.h
+++ b/sound/usb/debug.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #ifndef __USBAUDIO_DEBUG_H
 #define __USBAUDIO_DEBUG_H
 
diff --git a/sound/usb/endpoint.h b/sound/usb/endpoint.h
index 584f295d7c77..63a39d4fa8d8 100644
--- a/sound/usb/endpoint.h
+++ b/sound/usb/endpoint.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #ifndef __USBAUDIO_ENDPOINT_H
 #define __USBAUDIO_ENDPOINT_H
 
diff --git a/sound/usb/format.h b/sound/usb/format.h
index 4b8a01129f24..8c3ff9ce0824 100644
--- a/sound/usb/format.h
+++ b/sound/usb/format.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #ifndef __USBAUDIO_FORMAT_H
 #define __USBAUDIO_FORMAT_H
 
diff --git a/sound/usb/helper.h b/sound/usb/helper.h
index 805c300dd004..4463e6d6dcb3 100644
--- a/sound/usb/helper.h
+++ b/sound/usb/helper.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #ifndef __USBAUDIO_HELPER_H
 #define __USBAUDIO_HELPER_H
 
diff --git a/sound/usb/line6/Makefile b/sound/usb/line6/Makefile
index b8b3b2a543d8..4ba98eb32119 100644
--- a/sound/usb/line6/Makefile
+++ b/sound/usb/line6/Makefile
@@ -1,3 +1,4 @@
+# SPDX-License-Identifier: GPL-2.0
 snd-usb-line6-y := 		\
 		capture.o	\
 		driver.o	\
diff --git a/sound/usb/midi.h b/sound/usb/midi.h
index 5e25a3fd6c1d..8c38aec22999 100644
--- a/sound/usb/midi.h
+++ b/sound/usb/midi.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #ifndef __USBMIDI_H
 #define __USBMIDI_H
 
diff --git a/sound/usb/mixer.h b/sound/usb/mixer.h
index 545d99b09706..ba27f7ade670 100644
--- a/sound/usb/mixer.h
+++ b/sound/usb/mixer.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #ifndef __USBMIXER_H
 #define __USBMIXER_H
 
diff --git a/sound/usb/mixer_quirks.h b/sound/usb/mixer_quirks.h
index 177c329cd4dd..b5abd328a361 100644
--- a/sound/usb/mixer_quirks.h
+++ b/sound/usb/mixer_quirks.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #ifndef SND_USB_MIXER_QUIRKS_H
 #define SND_USB_MIXER_QUIRKS_H
 
diff --git a/sound/usb/mixer_scarlett.h b/sound/usb/mixer_scarlett.h
index 19c592ab0332..bbf063b79370 100644
--- a/sound/usb/mixer_scarlett.h
+++ b/sound/usb/mixer_scarlett.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #ifndef __USB_MIXER_SCARLETT_H
 #define __USB_MIXER_SCARLETT_H
 
diff --git a/sound/usb/mixer_us16x08.h b/sound/usb/mixer_us16x08.h
index a6312fb0f962..56ff16c0698f 100644
--- a/sound/usb/mixer_us16x08.h
+++ b/sound/usb/mixer_us16x08.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #ifndef __USB_MIXER_US16X08_H
 #define __USB_MIXER_US16X08_H
 
diff --git a/sound/usb/pcm.h b/sound/usb/pcm.h
index df7a003682ad..35740d5ef268 100644
--- a/sound/usb/pcm.h
+++ b/sound/usb/pcm.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #ifndef __USBAUDIO_PCM_H
 #define __USBAUDIO_PCM_H
 
diff --git a/sound/usb/power.h b/sound/usb/power.h
index 48ee51dcb71e..b2e25f60c5a2 100644
--- a/sound/usb/power.h
+++ b/sound/usb/power.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #ifndef __USBAUDIO_POWER_H
 #define __USBAUDIO_POWER_H
 
diff --git a/sound/usb/proc.h b/sound/usb/proc.h
index a45b765e4cf1..72b1b2d28b44 100644
--- a/sound/usb/proc.h
+++ b/sound/usb/proc.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #ifndef __USBAUDIO_PROC_H
 #define __USBAUDIO_PROC_H
 
diff --git a/sound/usb/quirks.h b/sound/usb/quirks.h
index 192ff5ce9452..b90c8b7caab5 100644
--- a/sound/usb/quirks.h
+++ b/sound/usb/quirks.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #ifndef __USBAUDIO_QUIRKS_H
 #define __USBAUDIO_QUIRKS_H
 
diff --git a/sound/usb/stream.h b/sound/usb/stream.h
index c97f679fc84f..d92e18d5818f 100644
--- a/sound/usb/stream.h
+++ b/sound/usb/stream.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #ifndef __USBAUDIO_STREAM_H
 #define __USBAUDIO_STREAM_H
 
diff --git a/sound/usb/usx2y/Makefile b/sound/usb/usx2y/Makefile
index 748933054b6c..cc4c2f1efab2 100644
--- a/sound/usb/usx2y/Makefile
+++ b/sound/usb/usx2y/Makefile
@@ -1,3 +1,4 @@
+# SPDX-License-Identifier: GPL-2.0
 snd-usb-usx2y-objs := usbusx2y.o usX2Yhwdep.o usx2yhwdeppcm.o
 snd-usb-us122l-objs := us122l.o
 
diff --git a/sound/usb/usx2y/us122l.h b/sound/usb/usx2y/us122l.h
index 3e2a2d0041ee..34bea99d343c 100644
--- a/sound/usb/usx2y/us122l.h
+++ b/sound/usb/usx2y/us122l.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #ifndef US122L_H
 #define US122L_H
 
diff --git a/sound/usb/usx2y/usX2Yhwdep.h b/sound/usb/usx2y/usX2Yhwdep.h
index c095d5bf1220..457199b5ed03 100644
--- a/sound/usb/usx2y/usX2Yhwdep.h
+++ b/sound/usb/usx2y/usX2Yhwdep.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #ifndef USX2YHWDEP_H
 #define USX2YHWDEP_H
 
diff --git a/sound/usb/usx2y/usb_stream.h b/sound/usb/usx2y/usb_stream.h
index 90369001eab6..851358a8d709 100644
--- a/sound/usb/usx2y/usb_stream.h
+++ b/sound/usb/usx2y/usb_stream.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #ifndef __USB_STREAM_H
 #define __USB_STREAM_H
 
diff --git a/sound/usb/usx2y/usbusx2y.h b/sound/usb/usx2y/usbusx2y.h
index 6ae6b0806938..e0f77172ce8f 100644
--- a/sound/usb/usx2y/usbusx2y.h
+++ b/sound/usb/usx2y/usbusx2y.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #ifndef USBUSX2Y_H
 #define USBUSX2Y_H
 #include "../usbaudio.h"
diff --git a/sound/usb/usx2y/usx2yhwdeppcm.h b/sound/usb/usx2y/usx2yhwdeppcm.h
index 9c4fb84b2aa0..eb5a46466f0e 100644
--- a/sound/usb/usx2y/usx2yhwdeppcm.h
+++ b/sound/usb/usx2y/usx2yhwdeppcm.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #define MAXPACK 50
 #define MAXBUFFERMS 100
 #define MAXSTRIDE 3