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>

20 files changed, 20 insertions, 0 deletions

diff --git a/include/linux/usb/atmel_usba_udc.h b/include/linux/usb/atmel_usba_udc.h
index ba99af275a31..9bb00df3b53f 100644
--- a/include/linux/usb/atmel_usba_udc.h
+++ b/include/linux/usb/atmel_usba_udc.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 /*
  * Platform data definitions for Atmel USBA gadget driver.
  */
diff --git a/include/linux/usb/ch9.h b/include/linux/usb/ch9.h
index 6cc96bb12ddc..523aa088f6ab 100644
--- a/include/linux/usb/ch9.h
+++ b/include/linux/usb/ch9.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 /*
  * This file holds USB constants and structures that are needed for
  * USB device APIs.  These are used by the USB device model, which is
diff --git a/include/linux/usb/chipidea.h b/include/linux/usb/chipidea.h
index d725cff7268d..07f99362bc90 100644
--- a/include/linux/usb/chipidea.h
+++ b/include/linux/usb/chipidea.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 /*
  * Platform data for the chipidea USB dual role controller
  */
diff --git a/include/linux/usb/ehci-dbgp.h b/include/linux/usb/ehci-dbgp.h
index 7344d9e591cc..62ab3805172d 100644
--- a/include/linux/usb/ehci-dbgp.h
+++ b/include/linux/usb/ehci-dbgp.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 /*
  * Standalone EHCI usb debug driver
  *
diff --git a/include/linux/usb/ezusb.h b/include/linux/usb/ezusb.h
index 639ee45779fb..487047162ca8 100644
--- a/include/linux/usb/ezusb.h
+++ b/include/linux/usb/ezusb.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #ifndef __EZUSB_H
 #define __EZUSB_H
 
diff --git a/include/linux/usb/functionfs.h b/include/linux/usb/functionfs.h
index 71190663f1ee..570578cc9861 100644
--- a/include/linux/usb/functionfs.h
+++ b/include/linux/usb/functionfs.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #ifndef __LINUX_FUNCTIONFS_H__
 #define __LINUX_FUNCTIONFS_H__ 1
 
diff --git a/include/linux/usb/gadget_configfs.h b/include/linux/usb/gadget_configfs.h
index c36e95730de1..d61aebd68128 100644
--- a/include/linux/usb/gadget_configfs.h
+++ b/include/linux/usb/gadget_configfs.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #ifndef __GADGET_CONFIGFS__
 #define __GADGET_CONFIGFS__
 
diff --git a/include/linux/usb/iowarrior.h b/include/linux/usb/iowarrior.h
index 4fd6513d564c..56559bc53214 100644
--- a/include/linux/usb/iowarrior.h
+++ b/include/linux/usb/iowarrior.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #ifndef __LINUX_USB_IOWARRIOR_H
 #define __LINUX_USB_IOWARRIOR_H
 
diff --git a/include/linux/usb/irda.h b/include/linux/usb/irda.h
index e345ceaf72d6..396d2b043e64 100644
--- a/include/linux/usb/irda.h
+++ b/include/linux/usb/irda.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 /*
  * USB IrDA Bridge Device Definition
  */
diff --git a/include/linux/usb/isp116x.h b/include/linux/usb/isp116x.h
index 96ca114e88d0..1f331c28bfe3 100644
--- a/include/linux/usb/isp116x.h
+++ b/include/linux/usb/isp116x.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 /*
  * Board initialization code should put one of these into dev->platform_data
  * and place the isp116x onto platform_bus.
diff --git a/include/linux/usb/isp1362.h b/include/linux/usb/isp1362.h
index 642684bb9292..5356c4ae386e 100644
--- a/include/linux/usb/isp1362.h
+++ b/include/linux/usb/isp1362.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 /*
  * board initialization code should put one of these into dev->platform_data
  * and place the isp1362 onto platform_bus.
diff --git a/include/linux/usb/isp1760.h b/include/linux/usb/isp1760.h
index de7de53c5531..b75ded28db81 100644
--- a/include/linux/usb/isp1760.h
+++ b/include/linux/usb/isp1760.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 /*
  * board initialization should put one of these into dev->platform_data
  * and place the isp1760 onto platform_bus named "isp1760-hcd".
diff --git a/include/linux/usb/musb.h b/include/linux/usb/musb.h
index d315c8907869..5d19e6730475 100644
--- a/include/linux/usb/musb.h
+++ b/include/linux/usb/musb.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 /*
  * This is used to for host and peripheral modes of the driver for
  * Inventra (Multidrop) Highspeed Dual-Role Controllers:  (M)HDRC.
diff --git a/include/linux/usb/otg.h b/include/linux/usb/otg.h
index 67929df86df5..69f1b6328532 100644
--- a/include/linux/usb/otg.h
+++ b/include/linux/usb/otg.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 /* USB OTG (On The Go) defines */
 /*
  *
diff --git a/include/linux/usb/phy.h b/include/linux/usb/phy.h
index 8c6914873a16..b7a2625947f5 100644
--- a/include/linux/usb/phy.h
+++ b/include/linux/usb/phy.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 /*
  * USB PHY defines
  *
diff --git a/include/linux/usb/quirks.h b/include/linux/usb/quirks.h
index de2a722fe3cf..7cd553a3ce05 100644
--- a/include/linux/usb/quirks.h
+++ b/include/linux/usb/quirks.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 /*
  * This file holds the definitions of quirks found in USB devices.
  * Only quirks that affect the whole device, not an interface,
diff --git a/include/linux/usb/sl811.h b/include/linux/usb/sl811.h
index 3afe4d16fcef..6c97f8e66492 100644
--- a/include/linux/usb/sl811.h
+++ b/include/linux/usb/sl811.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 /*
  * board initialization should put one of these into dev->platform_data
  * and place the sl811hs onto platform_bus named "sl811-hcd".
diff --git a/include/linux/usb/typec.h b/include/linux/usb/typec.h
index ffe7487886ca..0d44ce6af08f 100644
--- a/include/linux/usb/typec.h
+++ b/include/linux/usb/typec.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 
 #ifndef __LINUX_USB_TYPEC_H
 #define __LINUX_USB_TYPEC_H
diff --git a/include/linux/usb/uas.h b/include/linux/usb/uas.h
index 3fc8e8b9f043..aa3ad39d39dc 100644
--- a/include/linux/usb/uas.h
+++ b/include/linux/usb/uas.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #ifndef __USB_UAS_H__
 #define __USB_UAS_H__
 
diff --git a/include/linux/usb/usb_phy_generic.h b/include/linux/usb/usb_phy_generic.h
index c13632d5292e..7408cf52c710 100644
--- a/include/linux/usb/usb_phy_generic.h
+++ b/include/linux/usb/usb_phy_generic.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #ifndef __LINUX_USB_NOP_XCEIV_H
 #define __LINUX_USB_NOP_XCEIV_H