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>

27 files changed, 27 insertions, 0 deletions

diff --git a/include/xen/arm/hypervisor.h b/include/xen/arm/hypervisor.h
index 44b587b49904..2982571f7cc1 100644
--- a/include/xen/arm/hypervisor.h
+++ b/include/xen/arm/hypervisor.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #ifndef _ASM_ARM_XEN_HYPERVISOR_H
 #define _ASM_ARM_XEN_HYPERVISOR_H
 
diff --git a/include/xen/arm/interface.h b/include/xen/arm/interface.h
index 75d596862892..c3eada2642aa 100644
--- a/include/xen/arm/interface.h
+++ b/include/xen/arm/interface.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 /******************************************************************************
  * Guest OS interface to ARM Xen.
  *
diff --git a/include/xen/arm/page-coherent.h b/include/xen/arm/page-coherent.h
index b1b4ecdf329a..59a260712a56 100644
--- a/include/xen/arm/page-coherent.h
+++ b/include/xen/arm/page-coherent.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #ifndef _ASM_ARM_XEN_PAGE_COHERENT_H
 #define _ASM_ARM_XEN_PAGE_COHERENT_H
 
diff --git a/include/xen/arm/page.h b/include/xen/arm/page.h
index 6adc2a955340..f77dcbcba5a6 100644
--- a/include/xen/arm/page.h
+++ b/include/xen/arm/page.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #ifndef _ASM_ARM_XEN_PAGE_H
 #define _ASM_ARM_XEN_PAGE_H
 
diff --git a/include/xen/balloon.h b/include/xen/balloon.h
index 8906361bb50c..4914b93a23f2 100644
--- a/include/xen/balloon.h
+++ b/include/xen/balloon.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 /******************************************************************************
  * Xen balloon functionality
  */
diff --git a/include/xen/events.h b/include/xen/events.h
index f442ca5fcd82..c3e6bc643a7b 100644
--- a/include/xen/events.h
+++ b/include/xen/events.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #ifndef _XEN_EVENTS_H
 #define _XEN_EVENTS_H
 
diff --git a/include/xen/features.h b/include/xen/features.h
index 27292d4d2a6a..e4cb464386a9 100644
--- a/include/xen/features.h
+++ b/include/xen/features.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 /******************************************************************************
  * features.h
  *
diff --git a/include/xen/hvc-console.h b/include/xen/hvc-console.h
index b62dfef15f61..d8949d5e227d 100644
--- a/include/xen/hvc-console.h
+++ b/include/xen/hvc-console.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #ifndef XEN_HVC_CONSOLE_H
 #define XEN_HVC_CONSOLE_H
 
diff --git a/include/xen/hvm.h b/include/xen/hvm.h
index 63917a8de3b0..0b15f8cb17fc 100644
--- a/include/xen/hvm.h
+++ b/include/xen/hvm.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 /* Simple wrappers around HVM functions */
 #ifndef XEN_HVM_H__
 #define XEN_HVM_H__
diff --git a/include/xen/interface/event_channel.h b/include/xen/interface/event_channel.h
index 7e6acef5415b..45650c9a06d5 100644
--- a/include/xen/interface/event_channel.h
+++ b/include/xen/interface/event_channel.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 /******************************************************************************
  * event_channel.h
  *
diff --git a/include/xen/interface/features.h b/include/xen/interface/features.h
index 6ad3d110bb81..9b0eb574f0d1 100644
--- a/include/xen/interface/features.h
+++ b/include/xen/interface/features.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 /******************************************************************************
  * features.h
  *
diff --git a/include/xen/interface/io/blkif.h b/include/xen/interface/io/blkif.h
index 8b8cfadf7833..5e40041c7e95 100644
--- a/include/xen/interface/io/blkif.h
+++ b/include/xen/interface/io/blkif.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 /******************************************************************************
  * blkif.h
  *
diff --git a/include/xen/interface/io/console.h b/include/xen/interface/io/console.h
index e563de70f784..85ca8b02695a 100644
--- a/include/xen/interface/io/console.h
+++ b/include/xen/interface/io/console.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 /******************************************************************************
  * console.h
  *
diff --git a/include/xen/interface/io/protocols.h b/include/xen/interface/io/protocols.h
index 545a14ba0bb3..6a89dc1bf225 100644
--- a/include/xen/interface/io/protocols.h
+++ b/include/xen/interface/io/protocols.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #ifndef __XEN_PROTOCOLS_H__
 #define __XEN_PROTOCOLS_H__
 
diff --git a/include/xen/interface/io/ring.h b/include/xen/interface/io/ring.h
index e547088ceb0e..3f40501fc60b 100644
--- a/include/xen/interface/io/ring.h
+++ b/include/xen/interface/io/ring.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 /******************************************************************************
  * ring.h
  *
diff --git a/include/xen/interface/io/xenbus.h b/include/xen/interface/io/xenbus.h
index 9fda532973a5..aaf2951b1cce 100644
--- a/include/xen/interface/io/xenbus.h
+++ b/include/xen/interface/io/xenbus.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 /*****************************************************************************
  * xenbus.h
  *
diff --git a/include/xen/interface/io/xs_wire.h b/include/xen/interface/io/xs_wire.h
index 794deb07eb53..1517c7e93a3a 100644
--- a/include/xen/interface/io/xs_wire.h
+++ b/include/xen/interface/io/xs_wire.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 /*
  * Details of the "wire" protocol between Xen Store Daemon and client
  * library or guest kernel.
diff --git a/include/xen/interface/memory.h b/include/xen/interface/memory.h
index 9aa8988cb340..583dd93b3016 100644
--- a/include/xen/interface/memory.h
+++ b/include/xen/interface/memory.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 /******************************************************************************
  * memory.h
  *
diff --git a/include/xen/interface/nmi.h b/include/xen/interface/nmi.h
index b47d9d06fade..73d9b0a2974e 100644
--- a/include/xen/interface/nmi.h
+++ b/include/xen/interface/nmi.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 /******************************************************************************
  * nmi.h
  *
diff --git a/include/xen/interface/version.h b/include/xen/interface/version.h
index 145f12f9ecec..8772b552c006 100644
--- a/include/xen/interface/version.h
+++ b/include/xen/interface/version.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 /******************************************************************************
  * version.h
  *
diff --git a/include/xen/interface/xenpmu.h b/include/xen/interface/xenpmu.h
index 139efc91bceb..ad603eab24b3 100644
--- a/include/xen/interface/xenpmu.h
+++ b/include/xen/interface/xenpmu.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #ifndef __XEN_PUBLIC_XENPMU_H__
 #define __XEN_PUBLIC_XENPMU_H__
 
diff --git a/include/xen/page.h b/include/xen/page.h
index 064194f6453e..df6d6b6ec66e 100644
--- a/include/xen/page.h
+++ b/include/xen/page.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #ifndef _XEN_PAGE_H
 #define _XEN_PAGE_H
 
diff --git a/include/xen/platform_pci.h b/include/xen/platform_pci.h
index 5c52b5583917..e51e7cb71a85 100644
--- a/include/xen/platform_pci.h
+++ b/include/xen/platform_pci.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #ifndef _XEN_PLATFORM_PCI_H
 #define _XEN_PLATFORM_PCI_H
 
diff --git a/include/xen/swiotlb-xen.h b/include/xen/swiotlb-xen.h
index ed2de363da33..5e4b83f83dbc 100644
--- a/include/xen/swiotlb-xen.h
+++ b/include/xen/swiotlb-xen.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #ifndef __LINUX_SWIOTLB_XEN_H
 #define __LINUX_SWIOTLB_XEN_H
 
diff --git a/include/xen/tmem.h b/include/xen/tmem.h
index 3930a90045ff..c80bafe31f14 100644
--- a/include/xen/tmem.h
+++ b/include/xen/tmem.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #ifndef _XEN_TMEM_H
 #define _XEN_TMEM_H
 
diff --git a/include/xen/xen-ops.h b/include/xen/xen-ops.h
index 218e6aae5433..a95e65ec83c3 100644
--- a/include/xen/xen-ops.h
+++ b/include/xen/xen-ops.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #ifndef INCLUDE_XEN_OPS_H
 #define INCLUDE_XEN_OPS_H
 
diff --git a/include/xen/xen.h b/include/xen/xen.h
index 28c59ca529d7..9d4340c907d1 100644
--- a/include/xen/xen.h
+++ b/include/xen/xen.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #ifndef _XEN_XEN_H
 #define _XEN_XEN_H