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>

23 files changed, 23 insertions, 0 deletions

diff --git a/include/crypto/ablk_helper.h b/include/crypto/ablk_helper.h
index 4f93df50c23e..4e655c2a4e15 100644
--- a/include/crypto/ablk_helper.h
+++ b/include/crypto/ablk_helper.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 /*
  * Shared async block cipher helpers
  */
diff --git a/include/crypto/aes.h b/include/crypto/aes.h
index 7524ba3b6f3c..852eaa9cd4db 100644
--- a/include/crypto/aes.h
+++ b/include/crypto/aes.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 /*
  * Common values for AES algorithms
  */
diff --git a/include/crypto/blowfish.h b/include/crypto/blowfish.h
index 1450d4a27980..9b384670b356 100644
--- a/include/crypto/blowfish.h
+++ b/include/crypto/blowfish.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 /*
  * Common values for blowfish algorithms
  */
diff --git a/include/crypto/cast5.h b/include/crypto/cast5.h
index 14fbf39d6380..3d4ed4ea9c3b 100644
--- a/include/crypto/cast5.h
+++ b/include/crypto/cast5.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #ifndef _CRYPTO_CAST5_H
 #define _CRYPTO_CAST5_H
 
diff --git a/include/crypto/cast6.h b/include/crypto/cast6.h
index 32b60eb8bd24..c71f6ef47f0f 100644
--- a/include/crypto/cast6.h
+++ b/include/crypto/cast6.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #ifndef _CRYPTO_CAST6_H
 #define _CRYPTO_CAST6_H
 
diff --git a/include/crypto/cast_common.h b/include/crypto/cast_common.h
index b7df35cd9f0a..b90090244164 100644
--- a/include/crypto/cast_common.h
+++ b/include/crypto/cast_common.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #ifndef _CRYPTO_CAST_COMMON_H
 #define _CRYPTO_CAST_COMMON_H
 
diff --git a/include/crypto/chacha20.h b/include/crypto/chacha20.h
index 445fc45f4b5b..caaa470389e0 100644
--- a/include/crypto/chacha20.h
+++ b/include/crypto/chacha20.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 /*
  * Common values for the ChaCha20 algorithm
  */
diff --git a/include/crypto/cryptd.h b/include/crypto/cryptd.h
index 94418cbf9013..1e64f354c2b8 100644
--- a/include/crypto/cryptd.h
+++ b/include/crypto/cryptd.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 /*
  * Software async crypto daemon
  *
diff --git a/include/crypto/crypto_wq.h b/include/crypto/crypto_wq.h
index a7d252daf91b..23114746ac08 100644
--- a/include/crypto/crypto_wq.h
+++ b/include/crypto/crypto_wq.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #ifndef CRYPTO_WQ_H
 #define CRYPTO_WQ_H
 
diff --git a/include/crypto/des.h b/include/crypto/des.h
index fc6274c6bb26..d4094d58ac54 100644
--- a/include/crypto/des.h
+++ b/include/crypto/des.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 /* 
  * DES & Triple DES EDE Cipher Algorithms.
  */
diff --git a/include/crypto/ghash.h b/include/crypto/ghash.h
index 2a61c9bbab8f..9136301062a5 100644
--- a/include/crypto/ghash.h
+++ b/include/crypto/ghash.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 /*
  * Common values for GHASH algorithms
  */
diff --git a/include/crypto/hmac.h b/include/crypto/hmac.h
index ef09f7938204..66774132a7b6 100644
--- a/include/crypto/hmac.h
+++ b/include/crypto/hmac.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #ifndef _CRYPTO_HMAC_H
 #define _CRYPTO_HMAC_H
 
diff --git a/include/crypto/internal/simd.h b/include/crypto/internal/simd.h
index 429509968f68..32ceb6929885 100644
--- a/include/crypto/internal/simd.h
+++ b/include/crypto/internal/simd.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 /*
  * Shared crypto simd helpers
  */
diff --git a/include/crypto/lrw.h b/include/crypto/lrw.h
index 25a2c8716375..a9d44c06d081 100644
--- a/include/crypto/lrw.h
+++ b/include/crypto/lrw.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #ifndef _CRYPTO_LRW_H
 #define _CRYPTO_LRW_H
 
diff --git a/include/crypto/mcryptd.h b/include/crypto/mcryptd.h
index 4a53c0d38cd2..cceafa01f907 100644
--- a/include/crypto/mcryptd.h
+++ b/include/crypto/mcryptd.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 /*
  * Software async multibuffer crypto daemon headers
  *
diff --git a/include/crypto/md5.h b/include/crypto/md5.h
index 327deac963c0..cf9e9dec3d21 100644
--- a/include/crypto/md5.h
+++ b/include/crypto/md5.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #ifndef _CRYPTO_MD5_H
 #define _CRYPTO_MD5_H
 
diff --git a/include/crypto/null.h b/include/crypto/null.h
index 3f0c59fb0a61..5757c0a4b321 100644
--- a/include/crypto/null.h
+++ b/include/crypto/null.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 /* Values for NULL algorithms */
 
 #ifndef _CRYPTO_NULL_H
diff --git a/include/crypto/poly1305.h b/include/crypto/poly1305.h
index 894df59b74e4..c65567d01e8e 100644
--- a/include/crypto/poly1305.h
+++ b/include/crypto/poly1305.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 /*
  * Common values for the Poly1305 algorithm
  */
diff --git a/include/crypto/serpent.h b/include/crypto/serpent.h
index b7e0941eb6fc..7dd780c5d058 100644
--- a/include/crypto/serpent.h
+++ b/include/crypto/serpent.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 /*
  * Common values for serpent algorithms
  */
diff --git a/include/crypto/sha.h b/include/crypto/sha.h
index c94d3eb1cefd..0555b571dd34 100644
--- a/include/crypto/sha.h
+++ b/include/crypto/sha.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 /*
  * Common values for SHA algorithms
  */
diff --git a/include/crypto/sha3.h b/include/crypto/sha3.h
index f4c9f68f5ffe..b9d9bd553b48 100644
--- a/include/crypto/sha3.h
+++ b/include/crypto/sha3.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 /*
  * Common values for SHA-3 algorithms
  */
diff --git a/include/crypto/twofish.h b/include/crypto/twofish.h
index 095c901a8af3..2e2c09673d88 100644
--- a/include/crypto/twofish.h
+++ b/include/crypto/twofish.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #ifndef _CRYPTO_TWOFISH_H
 #define _CRYPTO_TWOFISH_H
 
diff --git a/include/crypto/xts.h b/include/crypto/xts.h
index c0bde308b28a..322aab6e78a7 100644
--- a/include/crypto/xts.h
+++ b/include/crypto/xts.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #ifndef _CRYPTO_XTS_H
 #define _CRYPTO_XTS_H