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>

25 files changed, 25 insertions, 0 deletions

diff --git a/net/ceph/Makefile b/net/ceph/Makefile
index 6a5180903e7b..b4bded4b5396 100644
--- a/net/ceph/Makefile
+++ b/net/ceph/Makefile
@@ -1,3 +1,4 @@
+# SPDX-License-Identifier: GPL-2.0
 #
 # Makefile for CEPH filesystem.
 #
diff --git a/net/ceph/armor.c b/net/ceph/armor.c
index 1fc1ee11dfa2..0db8065928df 100644
--- a/net/ceph/armor.c
+++ b/net/ceph/armor.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 
 #include <linux/errno.h>
 
diff --git a/net/ceph/auth.c b/net/ceph/auth.c
index 48bb8d95195b..dbde2b3c3c15 100644
--- a/net/ceph/auth.c
+++ b/net/ceph/auth.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #include <linux/ceph/ceph_debug.h>
 
 #include <linux/module.h>
diff --git a/net/ceph/auth_none.c b/net/ceph/auth_none.c
index df45e467c81f..41d2a0c72236 100644
--- a/net/ceph/auth_none.c
+++ b/net/ceph/auth_none.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 
 #include <linux/ceph/ceph_debug.h>
 
diff --git a/net/ceph/auth_none.h b/net/ceph/auth_none.h
index 62021535ae4a..860ed9875791 100644
--- a/net/ceph/auth_none.h
+++ b/net/ceph/auth_none.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #ifndef _FS_CEPH_AUTH_NONE_H
 #define _FS_CEPH_AUTH_NONE_H
 
diff --git a/net/ceph/auth_x.c b/net/ceph/auth_x.c
index 8757fb87dab8..2f4a1baf5f52 100644
--- a/net/ceph/auth_x.c
+++ b/net/ceph/auth_x.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 
 #include <linux/ceph/ceph_debug.h>
 
diff --git a/net/ceph/auth_x.h b/net/ceph/auth_x.h
index 48e9ad41bd2a..454cb54568af 100644
--- a/net/ceph/auth_x.h
+++ b/net/ceph/auth_x.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #ifndef _FS_CEPH_AUTH_X_H
 #define _FS_CEPH_AUTH_X_H
 
diff --git a/net/ceph/auth_x_protocol.h b/net/ceph/auth_x_protocol.h
index 671d30576c4f..32c13d763b9a 100644
--- a/net/ceph/auth_x_protocol.h
+++ b/net/ceph/auth_x_protocol.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #ifndef __FS_CEPH_AUTH_X_PROTOCOL
 #define __FS_CEPH_AUTH_X_PROTOCOL
 
diff --git a/net/ceph/buffer.c b/net/ceph/buffer.c
index add5f921a0ff..5622763ad402 100644
--- a/net/ceph/buffer.c
+++ b/net/ceph/buffer.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 
 #include <linux/ceph/ceph_debug.h>
 
diff --git a/net/ceph/ceph_fs.c b/net/ceph/ceph_fs.c
index dcbe67ff3e2b..756a2dc10d27 100644
--- a/net/ceph/ceph_fs.c
+++ b/net/ceph/ceph_fs.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 /*
  * Some non-inline ceph helpers
  */
diff --git a/net/ceph/ceph_strings.c b/net/ceph/ceph_strings.c
index 19b7d8aa915c..10e01494993c 100644
--- a/net/ceph/ceph_strings.c
+++ b/net/ceph/ceph_strings.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 /*
  * Ceph string constants
  */
diff --git a/net/ceph/cls_lock_client.c b/net/ceph/cls_lock_client.c
index 08ada893f01e..8d2032b2f225 100644
--- a/net/ceph/cls_lock_client.c
+++ b/net/ceph/cls_lock_client.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #include <linux/ceph/ceph_debug.h>
 
 #include <linux/types.h>
diff --git a/net/ceph/crush/crush.c b/net/ceph/crush/crush.c
index 4b428f46a8ca..3d70244bc1b6 100644
--- a/net/ceph/crush/crush.c
+++ b/net/ceph/crush/crush.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #ifdef __KERNEL__
 # include <linux/slab.h>
 # include <linux/crush/crush.h>
diff --git a/net/ceph/crush/hash.c b/net/ceph/crush/hash.c
index ed123af49eba..e5cc603cdb17 100644
--- a/net/ceph/crush/hash.c
+++ b/net/ceph/crush/hash.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #ifdef __KERNEL__
 # include <linux/crush/hash.h>
 #else
diff --git a/net/ceph/crypto.c b/net/ceph/crypto.c
index 46008d5ac504..489610ac1cdd 100644
--- a/net/ceph/crypto.c
+++ b/net/ceph/crypto.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 
 #include <linux/ceph/ceph_debug.h>
 
diff --git a/net/ceph/crypto.h b/net/ceph/crypto.h
index 58d83aa7740f..bb45c7d43739 100644
--- a/net/ceph/crypto.h
+++ b/net/ceph/crypto.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #ifndef _FS_CEPH_CRYPTO_H
 #define _FS_CEPH_CRYPTO_H
 
diff --git a/net/ceph/debugfs.c b/net/ceph/debugfs.c
index fa5233e0d01c..1eef6806aa1a 100644
--- a/net/ceph/debugfs.c
+++ b/net/ceph/debugfs.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #include <linux/ceph/ceph_debug.h>
 
 #include <linux/device.h>
diff --git a/net/ceph/messenger.c b/net/ceph/messenger.c
index a67298c7e0cd..ad93342c90d7 100644
--- a/net/ceph/messenger.c
+++ b/net/ceph/messenger.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #include <linux/ceph/ceph_debug.h>
 
 #include <linux/crc32c.h>
diff --git a/net/ceph/mon_client.c b/net/ceph/mon_client.c
index 63edc6e5f026..9ae1bab8c05d 100644
--- a/net/ceph/mon_client.c
+++ b/net/ceph/mon_client.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #include <linux/ceph/ceph_debug.h>
 
 #include <linux/module.h>
diff --git a/net/ceph/msgpool.c b/net/ceph/msgpool.c
index aaed59a47b1d..72571535883f 100644
--- a/net/ceph/msgpool.c
+++ b/net/ceph/msgpool.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #include <linux/ceph/ceph_debug.h>
 
 #include <linux/err.h>
diff --git a/net/ceph/osd_client.c b/net/ceph/osd_client.c
index e02f01f534e2..2814dba5902d 100644
--- a/net/ceph/osd_client.c
+++ b/net/ceph/osd_client.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 
 #include <linux/ceph/ceph_debug.h>
 
diff --git a/net/ceph/osdmap.c b/net/ceph/osdmap.c
index 79d14d70b7ea..0da27c66349a 100644
--- a/net/ceph/osdmap.c
+++ b/net/ceph/osdmap.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 
 #include <linux/ceph/ceph_debug.h>
 
diff --git a/net/ceph/pagelist.c b/net/ceph/pagelist.c
index ce09f73be759..2ea0564771d2 100644
--- a/net/ceph/pagelist.c
+++ b/net/ceph/pagelist.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #include <linux/module.h>
 #include <linux/gfp.h>
 #include <linux/slab.h>
diff --git a/net/ceph/pagevec.c b/net/ceph/pagevec.c
index 1a7c9a79a53c..ee43bc13221c 100644
--- a/net/ceph/pagevec.c
+++ b/net/ceph/pagevec.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #include <linux/ceph/ceph_debug.h>
 
 #include <linux/module.h>
diff --git a/net/ceph/string_table.c b/net/ceph/string_table.c
index 22fb96efcf34..3191d9d160a2 100644
--- a/net/ceph/string_table.c
+++ b/net/ceph/string_table.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #include <linux/slab.h>
 #include <linux/gfp.h>
 #include <linux/string.h>