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>

41 files changed, 41 insertions, 0 deletions

diff --git a/drivers/md/Makefile b/drivers/md/Makefile
index 786ec9e86d65..e94b6f9be941 100644
--- a/drivers/md/Makefile
+++ b/drivers/md/Makefile
@@ -1,3 +1,4 @@
+# SPDX-License-Identifier: GPL-2.0
 #
 # Makefile for the kernel software RAID and LVM drivers.
 #
diff --git a/drivers/md/bcache/Makefile b/drivers/md/bcache/Makefile
index c488b846f831..d26b35195825 100644
--- a/drivers/md/bcache/Makefile
+++ b/drivers/md/bcache/Makefile
@@ -1,3 +1,4 @@
+# SPDX-License-Identifier: GPL-2.0
 
 obj-$(CONFIG_BCACHE)	+= bcache.o
 
diff --git a/drivers/md/bcache/alloc.c b/drivers/md/bcache/alloc.c
index cacbe2dbd5c3..08035634795c 100644
--- a/drivers/md/bcache/alloc.c
+++ b/drivers/md/bcache/alloc.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 /*
  * Primary bucket allocation code
  *
diff --git a/drivers/md/bcache/bcache.h b/drivers/md/bcache/bcache.h
index 2ed9bd231d84..abd31e847f96 100644
--- a/drivers/md/bcache/bcache.h
+++ b/drivers/md/bcache/bcache.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #ifndef _BCACHE_H
 #define _BCACHE_H
 
diff --git a/drivers/md/bcache/bset.c b/drivers/md/bcache/bset.c
index 18526d44688d..e56d3ecdbfcb 100644
--- a/drivers/md/bcache/bset.c
+++ b/drivers/md/bcache/bset.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 /*
  * Code for working with individual keys, and sorted sets of keys with in a
  * btree node
diff --git a/drivers/md/bcache/bset.h b/drivers/md/bcache/bset.h
index ae964624efb2..fa506c1aa524 100644
--- a/drivers/md/bcache/bset.h
+++ b/drivers/md/bcache/bset.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #ifndef _BCACHE_BSET_H
 #define _BCACHE_BSET_H
 
diff --git a/drivers/md/bcache/btree.c b/drivers/md/bcache/btree.c
index 866dcf78ff8e..658c54b3b07a 100644
--- a/drivers/md/bcache/btree.c
+++ b/drivers/md/bcache/btree.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 /*
  * Copyright (C) 2010 Kent Overstreet <kent.overstreet@gmail.com>
  *
diff --git a/drivers/md/bcache/btree.h b/drivers/md/bcache/btree.h
index 73da1f5626cb..42204d61bc95 100644
--- a/drivers/md/bcache/btree.h
+++ b/drivers/md/bcache/btree.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #ifndef _BCACHE_BTREE_H
 #define _BCACHE_BTREE_H
 
diff --git a/drivers/md/bcache/closure.h b/drivers/md/bcache/closure.h
index 295b7e43f92c..965907ce1e20 100644
--- a/drivers/md/bcache/closure.h
+++ b/drivers/md/bcache/closure.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #ifndef _LINUX_CLOSURE_H
 #define _LINUX_CLOSURE_H
 
diff --git a/drivers/md/bcache/debug.c b/drivers/md/bcache/debug.c
index 61076eda2e6d..c7a02c4900da 100644
--- a/drivers/md/bcache/debug.c
+++ b/drivers/md/bcache/debug.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 /*
  * Assorted bcache debug code
  *
diff --git a/drivers/md/bcache/debug.h b/drivers/md/bcache/debug.h
index 1f63c195d247..acc48d3fa274 100644
--- a/drivers/md/bcache/debug.h
+++ b/drivers/md/bcache/debug.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #ifndef _BCACHE_DEBUG_H
 #define _BCACHE_DEBUG_H
 
diff --git a/drivers/md/bcache/extents.c b/drivers/md/bcache/extents.c
index 243de0bf15cd..41c238fc3733 100644
--- a/drivers/md/bcache/extents.c
+++ b/drivers/md/bcache/extents.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 /*
  * Copyright (C) 2010 Kent Overstreet <kent.overstreet@gmail.com>
  *
diff --git a/drivers/md/bcache/extents.h b/drivers/md/bcache/extents.h
index e2ed54054e7a..0cd3575afa1d 100644
--- a/drivers/md/bcache/extents.h
+++ b/drivers/md/bcache/extents.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #ifndef _BCACHE_EXTENTS_H
 #define _BCACHE_EXTENTS_H
 
diff --git a/drivers/md/bcache/io.c b/drivers/md/bcache/io.c
index 7e871bdc0097..fac97ec2d0e2 100644
--- a/drivers/md/bcache/io.c
+++ b/drivers/md/bcache/io.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 /*
  * Some low level IO code, and hacks for various block layer limitations
  *
diff --git a/drivers/md/bcache/journal.c b/drivers/md/bcache/journal.c
index 7e1d1c3ba33a..02a98ddb592d 100644
--- a/drivers/md/bcache/journal.c
+++ b/drivers/md/bcache/journal.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 /*
  * bcache journalling code, for btree insertions
  *
diff --git a/drivers/md/bcache/journal.h b/drivers/md/bcache/journal.h
index e3c39457afbb..b5788199188f 100644
--- a/drivers/md/bcache/journal.h
+++ b/drivers/md/bcache/journal.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #ifndef _BCACHE_JOURNAL_H
 #define _BCACHE_JOURNAL_H
 
diff --git a/drivers/md/bcache/movinggc.c b/drivers/md/bcache/movinggc.c
index f633b30c962e..d50c1c97da68 100644
--- a/drivers/md/bcache/movinggc.c
+++ b/drivers/md/bcache/movinggc.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 /*
  * Moving/copying garbage collector
  *
diff --git a/drivers/md/bcache/request.c b/drivers/md/bcache/request.c
index 681b4f12b05a..3475d6628e21 100644
--- a/drivers/md/bcache/request.c
+++ b/drivers/md/bcache/request.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 /*
  * Main bcache entry point - handle a read or a write request and decide what to
  * do with it; the make_request functions are called by the block layer.
diff --git a/drivers/md/bcache/request.h b/drivers/md/bcache/request.h
index 7689176951ce..dea0886b81c1 100644
--- a/drivers/md/bcache/request.h
+++ b/drivers/md/bcache/request.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #ifndef _BCACHE_REQUEST_H_
 #define _BCACHE_REQUEST_H_
 
diff --git a/drivers/md/bcache/stats.c b/drivers/md/bcache/stats.c
index 0ca072c20d0d..d0831d5bcc87 100644
--- a/drivers/md/bcache/stats.c
+++ b/drivers/md/bcache/stats.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 /*
  * bcache stats code
  *
diff --git a/drivers/md/bcache/stats.h b/drivers/md/bcache/stats.h
index adbff141c887..0b70f9de0c03 100644
--- a/drivers/md/bcache/stats.h
+++ b/drivers/md/bcache/stats.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #ifndef _BCACHE_STATS_H_
 #define _BCACHE_STATS_H_
 
diff --git a/drivers/md/bcache/sysfs.c b/drivers/md/bcache/sysfs.c
index 104c57cd666c..234b2f5b286d 100644
--- a/drivers/md/bcache/sysfs.c
+++ b/drivers/md/bcache/sysfs.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 /*
  * bcache sysfs interfaces
  *
diff --git a/drivers/md/bcache/sysfs.h b/drivers/md/bcache/sysfs.h
index 0526fe92a683..b54fe9602529 100644
--- a/drivers/md/bcache/sysfs.h
+++ b/drivers/md/bcache/sysfs.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #ifndef _BCACHE_SYSFS_H_
 #define _BCACHE_SYSFS_H_
 
diff --git a/drivers/md/bcache/trace.c b/drivers/md/bcache/trace.c
index b7820b0d2621..a9a73f560c04 100644
--- a/drivers/md/bcache/trace.c
+++ b/drivers/md/bcache/trace.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #include "bcache.h"
 #include "btree.h"
 
diff --git a/drivers/md/bcache/util.h b/drivers/md/bcache/util.h
index cb8d2ccbb6c6..f54b58282f77 100644
--- a/drivers/md/bcache/util.h
+++ b/drivers/md/bcache/util.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 
 #ifndef _BCACHE_UTIL_H
 #define _BCACHE_UTIL_H
diff --git a/drivers/md/bcache/writeback.c b/drivers/md/bcache/writeback.c
index e663ca082183..70454f2ad2fa 100644
--- a/drivers/md/bcache/writeback.c
+++ b/drivers/md/bcache/writeback.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 /*
  * background writeback - scan btree for dirty data and write it to the backing
  * device
diff --git a/drivers/md/bcache/writeback.h b/drivers/md/bcache/writeback.h
index e35421d20d2e..151544740148 100644
--- a/drivers/md/bcache/writeback.h
+++ b/drivers/md/bcache/writeback.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #ifndef _BCACHE_WRITEBACK_H
 #define _BCACHE_WRITEBACK_H
 
diff --git a/drivers/md/bitmap.h b/drivers/md/bitmap.h
index d15721ac07a6..5df35ca90f58 100644
--- a/drivers/md/bitmap.h
+++ b/drivers/md/bitmap.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 /*
  * bitmap.h: Copyright (C) Peter T. Breuer (ptb@ot.uc3m.es) 2003
  *
diff --git a/drivers/md/dm-builtin.c b/drivers/md/dm-builtin.c
index f092771878c2..8eb52e425141 100644
--- a/drivers/md/dm-builtin.c
+++ b/drivers/md/dm-builtin.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #include "dm-core.h"
 
 /*
diff --git a/drivers/md/dm-stats.c b/drivers/md/dm-stats.c
index 6028d8247f58..a7868503d135 100644
--- a/drivers/md/dm-stats.c
+++ b/drivers/md/dm-stats.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #include <linux/errno.h>
 #include <linux/numa.h>
 #include <linux/slab.h>
diff --git a/drivers/md/dm-stats.h b/drivers/md/dm-stats.h
index f1c0956e3843..2ddfae678f32 100644
--- a/drivers/md/dm-stats.h
+++ b/drivers/md/dm-stats.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #ifndef DM_STATS_H
 #define DM_STATS_H
 
diff --git a/drivers/md/linear.h b/drivers/md/linear.h
index 8d392e6098b3..8381d651d4ed 100644
--- a/drivers/md/linear.h
+++ b/drivers/md/linear.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #ifndef _LINEAR_H
 #define _LINEAR_H
 
diff --git a/drivers/md/md-cluster.h b/drivers/md/md-cluster.h
index 274016177983..c0240708f443 100644
--- a/drivers/md/md-cluster.h
+++ b/drivers/md/md-cluster.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 
 
 #ifndef _MD_CLUSTER_H
diff --git a/drivers/md/multipath.h b/drivers/md/multipath.h
index 717c60f62898..0adb941f485a 100644
--- a/drivers/md/multipath.h
+++ b/drivers/md/multipath.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #ifndef _MULTIPATH_H
 #define _MULTIPATH_H
 
diff --git a/drivers/md/persistent-data/Makefile b/drivers/md/persistent-data/Makefile
index ff528792c358..66be7c66479a 100644
--- a/drivers/md/persistent-data/Makefile
+++ b/drivers/md/persistent-data/Makefile
@@ -1,3 +1,4 @@
+# SPDX-License-Identifier: GPL-2.0
 obj-$(CONFIG_DM_PERSISTENT_DATA) += dm-persistent-data.o
 dm-persistent-data-objs := \
 	dm-array.o \
diff --git a/drivers/md/raid0.h b/drivers/md/raid0.h
index 7127a623f5da..540e65d92642 100644
--- a/drivers/md/raid0.h
+++ b/drivers/md/raid0.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #ifndef _RAID0_H
 #define _RAID0_H
 
diff --git a/drivers/md/raid1-10.c b/drivers/md/raid1-10.c
index 9f2670b45f31..400001b815db 100644
--- a/drivers/md/raid1-10.c
+++ b/drivers/md/raid1-10.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 /* Maximum size of each resync request */
 #define RESYNC_BLOCK_SIZE (64*1024)
 #define RESYNC_PAGES ((RESYNC_BLOCK_SIZE + PAGE_SIZE-1) / PAGE_SIZE)
diff --git a/drivers/md/raid1.h b/drivers/md/raid1.h
index c8894ef1e9d2..c7294e7557e0 100644
--- a/drivers/md/raid1.h
+++ b/drivers/md/raid1.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #ifndef _RAID1_H
 #define _RAID1_H
 
diff --git a/drivers/md/raid10.h b/drivers/md/raid10.h
index 735ce1a3d260..abceccab6671 100644
--- a/drivers/md/raid10.h
+++ b/drivers/md/raid10.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #ifndef _RAID10_H
 #define _RAID10_H
 
diff --git a/drivers/md/raid5-log.h b/drivers/md/raid5-log.h
index 328d67aedda4..7f9ad5f7cda0 100644
--- a/drivers/md/raid5-log.h
+++ b/drivers/md/raid5-log.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #ifndef _RAID5_LOG_H
 #define _RAID5_LOG_H
 
diff --git a/drivers/md/raid5.h b/drivers/md/raid5.h
index f6536399677a..2e6123825095 100644
--- a/drivers/md/raid5.h
+++ b/drivers/md/raid5.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #ifndef _RAID5_H
 #define _RAID5_H