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>

24 files changed, 24 insertions, 0 deletions

diff --git a/arch/m68k/coldfire/Makefile b/arch/m68k/coldfire/Makefile
index 4aa2c57afc35..f8cef9681416 100644
--- a/arch/m68k/coldfire/Makefile
+++ b/arch/m68k/coldfire/Makefile
@@ -1,3 +1,4 @@
+# SPDX-License-Identifier: GPL-2.0
 #
 # Makefile for the m68knommu kernel.
 #
diff --git a/arch/m68k/coldfire/cache.c b/arch/m68k/coldfire/cache.c
index 71beeaf0c5c4..98ee89b87439 100644
--- a/arch/m68k/coldfire/cache.c
+++ b/arch/m68k/coldfire/cache.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 /***************************************************************************/
 
 /*
diff --git a/arch/m68k/coldfire/clk.c b/arch/m68k/coldfire/clk.c
index 856069a3196d..849cd208e2ed 100644
--- a/arch/m68k/coldfire/clk.c
+++ b/arch/m68k/coldfire/clk.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 /***************************************************************************/
 
 /*
diff --git a/arch/m68k/coldfire/dma.c b/arch/m68k/coldfire/dma.c
index df5ce20d181c..c3279f7467d7 100644
--- a/arch/m68k/coldfire/dma.c
+++ b/arch/m68k/coldfire/dma.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 /***************************************************************************/
 
 /*
diff --git a/arch/m68k/coldfire/dma_timer.c b/arch/m68k/coldfire/dma_timer.c
index 8273eea57874..cbb289439606 100644
--- a/arch/m68k/coldfire/dma_timer.c
+++ b/arch/m68k/coldfire/dma_timer.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 /*
  * dma_timer.c -- Freescale ColdFire DMA Timer.
  *
diff --git a/arch/m68k/coldfire/firebee.c b/arch/m68k/coldfire/firebee.c
index 46d50534f981..3b9d4fc6f12e 100644
--- a/arch/m68k/coldfire/firebee.c
+++ b/arch/m68k/coldfire/firebee.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 /***************************************************************************/
 
 /*
diff --git a/arch/m68k/coldfire/head.S b/arch/m68k/coldfire/head.S
index bdb472c48401..c6d7fd28c602 100644
--- a/arch/m68k/coldfire/head.S
+++ b/arch/m68k/coldfire/head.S
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 /*****************************************************************************/
 
 /*
diff --git a/arch/m68k/coldfire/m5206.c b/arch/m68k/coldfire/m5206.c
index a3bcf0883f98..2f14ea95c391 100644
--- a/arch/m68k/coldfire/m5206.c
+++ b/arch/m68k/coldfire/m5206.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 /***************************************************************************/
 
 /*
diff --git a/arch/m68k/coldfire/m520x.c b/arch/m68k/coldfire/m520x.c
index 5ba69217ce6c..b5b2a267dada 100644
--- a/arch/m68k/coldfire/m520x.c
+++ b/arch/m68k/coldfire/m520x.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 /***************************************************************************/
 
 /*
diff --git a/arch/m68k/coldfire/m523x.c b/arch/m68k/coldfire/m523x.c
index f7a0fcc5618c..ddf2496ed117 100644
--- a/arch/m68k/coldfire/m523x.c
+++ b/arch/m68k/coldfire/m523x.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 /***************************************************************************/
 
 /*
diff --git a/arch/m68k/coldfire/m5249.c b/arch/m68k/coldfire/m5249.c
index b16cf9b4580c..0590f8c421f1 100644
--- a/arch/m68k/coldfire/m5249.c
+++ b/arch/m68k/coldfire/m5249.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 /***************************************************************************/
 
 /*
diff --git a/arch/m68k/coldfire/m525x.c b/arch/m68k/coldfire/m525x.c
index 110e2cd34e62..1772359c416c 100644
--- a/arch/m68k/coldfire/m525x.c
+++ b/arch/m68k/coldfire/m525x.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 /***************************************************************************/
 
 /*
diff --git a/arch/m68k/coldfire/m5272.c b/arch/m68k/coldfire/m5272.c
index 9abb1a441da0..ad1185c68df7 100644
--- a/arch/m68k/coldfire/m5272.c
+++ b/arch/m68k/coldfire/m5272.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 /***************************************************************************/
 
 /*
diff --git a/arch/m68k/coldfire/m527x.c b/arch/m68k/coldfire/m527x.c
index b10b436b5a31..cad462df6861 100644
--- a/arch/m68k/coldfire/m527x.c
+++ b/arch/m68k/coldfire/m527x.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 /***************************************************************************/
 
 /*
diff --git a/arch/m68k/coldfire/m528x.c b/arch/m68k/coldfire/m528x.c
index ea76998d5ab9..7ad3193887e8 100644
--- a/arch/m68k/coldfire/m528x.c
+++ b/arch/m68k/coldfire/m528x.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 /***************************************************************************/
 
 /*
diff --git a/arch/m68k/coldfire/m5307.c b/arch/m68k/coldfire/m5307.c
index cc5e8a50a423..64b4b1fd34ff 100644
--- a/arch/m68k/coldfire/m5307.c
+++ b/arch/m68k/coldfire/m5307.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 /***************************************************************************/
 
 /*
diff --git a/arch/m68k/coldfire/m5407.c b/arch/m68k/coldfire/m5407.c
index 38863ddbeab0..0400d76115a1 100644
--- a/arch/m68k/coldfire/m5407.c
+++ b/arch/m68k/coldfire/m5407.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 /***************************************************************************/
 
 /*
diff --git a/arch/m68k/coldfire/m5441x.c b/arch/m68k/coldfire/m5441x.c
index 04fd7fde9fb3..315d14b0dca0 100644
--- a/arch/m68k/coldfire/m5441x.c
+++ b/arch/m68k/coldfire/m5441x.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 /*
  *	m5441x.c -- support for Coldfire m5441x processors
  *
diff --git a/arch/m68k/coldfire/m54xx.c b/arch/m68k/coldfire/m54xx.c
index c552851ec617..e53ffed13ba8 100644
--- a/arch/m68k/coldfire/m54xx.c
+++ b/arch/m68k/coldfire/m54xx.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 /***************************************************************************/
 
 /*
diff --git a/arch/m68k/coldfire/nettel.c b/arch/m68k/coldfire/nettel.c
index ddc48ec1b800..ea8df6e7a6cc 100644
--- a/arch/m68k/coldfire/nettel.c
+++ b/arch/m68k/coldfire/nettel.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 /***************************************************************************/
 
 /*
diff --git a/arch/m68k/coldfire/pit.c b/arch/m68k/coldfire/pit.c
index 6c0878018b44..eb6f16b0e2e6 100644
--- a/arch/m68k/coldfire/pit.c
+++ b/arch/m68k/coldfire/pit.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 /***************************************************************************/
 
 /*
diff --git a/arch/m68k/coldfire/sltimers.c b/arch/m68k/coldfire/sltimers.c
index 3292c0d68b18..1b11e7bacab3 100644
--- a/arch/m68k/coldfire/sltimers.c
+++ b/arch/m68k/coldfire/sltimers.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 /***************************************************************************/
 
 /*
diff --git a/arch/m68k/coldfire/timers.c b/arch/m68k/coldfire/timers.c
index 2dc7a58204f6..227aa5d13709 100644
--- a/arch/m68k/coldfire/timers.c
+++ b/arch/m68k/coldfire/timers.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 /***************************************************************************/
 
 /*
diff --git a/arch/m68k/coldfire/vectors.c b/arch/m68k/coldfire/vectors.c
index 08923fe600e0..3bf0d69eec9e 100644
--- a/arch/m68k/coldfire/vectors.c
+++ b/arch/m68k/coldfire/vectors.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 /***************************************************************************/
 
 /*