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/dt-bindings/clock/berlin2.h b/include/dt-bindings/clock/berlin2.h
index 0c30800175dfa..b07b8efab0754 100644
--- a/include/dt-bindings/clock/berlin2.h
+++ b/include/dt-bindings/clock/berlin2.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 /*
  * Berlin2 BG2/BG2CD clock tree IDs
  */
diff --git a/include/dt-bindings/clock/berlin2q.h b/include/dt-bindings/clock/berlin2q.h
index 72eaf91c9ca6c..44b4ac3828508 100644
--- a/include/dt-bindings/clock/berlin2q.h
+++ b/include/dt-bindings/clock/berlin2q.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 /*
  * Berlin2 BG2Q clock tree IDs
  */
diff --git a/include/dt-bindings/clock/cortina,gemini-clock.h b/include/dt-bindings/clock/cortina,gemini-clock.h
index acf5cd550b0c7..04c3404b2d335 100644
--- a/include/dt-bindings/clock/cortina,gemini-clock.h
+++ b/include/dt-bindings/clock/cortina,gemini-clock.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #ifndef DT_BINDINGS_CORTINA_GEMINI_CLOCK_H
 #define DT_BINDINGS_CORTINA_GEMINI_CLOCK_H
 
diff --git a/include/dt-bindings/clock/efm32-cmu.h b/include/dt-bindings/clock/efm32-cmu.h
index b21b91e736af0..4b48d15fe194f 100644
--- a/include/dt-bindings/clock/efm32-cmu.h
+++ b/include/dt-bindings/clock/efm32-cmu.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #ifndef __DT_BINDINGS_CLOCK_EFM32_CMU_H
 #define __DT_BINDINGS_CLOCK_EFM32_CMU_H
 
diff --git a/include/dt-bindings/clock/exynos-audss-clk.h b/include/dt-bindings/clock/exynos-audss-clk.h
index 0ae6f5a75d2a5..eee9fcc6e6af2 100644
--- a/include/dt-bindings/clock/exynos-audss-clk.h
+++ b/include/dt-bindings/clock/exynos-audss-clk.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 /*
  * This header provides constants for Samsung audio subsystem
  * clock controller.
diff --git a/include/dt-bindings/clock/gxbb-clkc.h b/include/dt-bindings/clock/gxbb-clkc.h
index c04a76d8facff..8c92528aa48ad 100644
--- a/include/dt-bindings/clock/gxbb-clkc.h
+++ b/include/dt-bindings/clock/gxbb-clkc.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 /*
  * GXBB clock tree IDs
  */
diff --git a/include/dt-bindings/clock/jz4740-cgu.h b/include/dt-bindings/clock/jz4740-cgu.h
index 43153d3e9bd26..6ed83f926ae71 100644
--- a/include/dt-bindings/clock/jz4740-cgu.h
+++ b/include/dt-bindings/clock/jz4740-cgu.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 /*
  * This header provides clock numbers for the ingenic,jz4740-cgu DT binding.
  *
diff --git a/include/dt-bindings/clock/jz4780-cgu.h b/include/dt-bindings/clock/jz4780-cgu.h
index 467165e3cfee4..1859ce53ee388 100644
--- a/include/dt-bindings/clock/jz4780-cgu.h
+++ b/include/dt-bindings/clock/jz4780-cgu.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 /*
  * This header provides clock numbers for the ingenic,jz4780-cgu DT binding.
  *
diff --git a/include/dt-bindings/clock/marvell,mmp2.h b/include/dt-bindings/clock/marvell,mmp2.h
index 7a510384a82ae..228a5e234af04 100644
--- a/include/dt-bindings/clock/marvell,mmp2.h
+++ b/include/dt-bindings/clock/marvell,mmp2.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #ifndef __DTS_MARVELL_MMP2_CLOCK_H
 #define __DTS_MARVELL_MMP2_CLOCK_H
 
diff --git a/include/dt-bindings/clock/marvell,pxa168.h b/include/dt-bindings/clock/marvell,pxa168.h
index 3e45bdfe1aa45..caf90436b8483 100644
--- a/include/dt-bindings/clock/marvell,pxa168.h
+++ b/include/dt-bindings/clock/marvell,pxa168.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #ifndef __DTS_MARVELL_PXA168_CLOCK_H
 #define __DTS_MARVELL_PXA168_CLOCK_H
 
diff --git a/include/dt-bindings/clock/marvell,pxa1928.h b/include/dt-bindings/clock/marvell,pxa1928.h
index d4f2e18919ff8..5dca4820297fe 100644
--- a/include/dt-bindings/clock/marvell,pxa1928.h
+++ b/include/dt-bindings/clock/marvell,pxa1928.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #ifndef __DTS_MARVELL_PXA1928_CLOCK_H
 #define __DTS_MARVELL_PXA1928_CLOCK_H
 
diff --git a/include/dt-bindings/clock/marvell,pxa910.h b/include/dt-bindings/clock/marvell,pxa910.h
index 135082a0b62f6..7bf46238946eb 100644
--- a/include/dt-bindings/clock/marvell,pxa910.h
+++ b/include/dt-bindings/clock/marvell,pxa910.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #ifndef __DTS_MARVELL_PXA910_CLOCK_H
 #define __DTS_MARVELL_PXA910_CLOCK_H
 
diff --git a/include/dt-bindings/clock/meson8b-clkc.h b/include/dt-bindings/clock/meson8b-clkc.h
index a9c0306330b6a..dea9d46d4fa7c 100644
--- a/include/dt-bindings/clock/meson8b-clkc.h
+++ b/include/dt-bindings/clock/meson8b-clkc.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 /*
  * Meson8b clock tree IDs
  */
diff --git a/include/dt-bindings/clock/mpc512x-clock.h b/include/dt-bindings/clock/mpc512x-clock.h
index 4f94919327ced..13c316bf2796b 100644
--- a/include/dt-bindings/clock/mpc512x-clock.h
+++ b/include/dt-bindings/clock/mpc512x-clock.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 /*
  * This header provides constants for MPC512x clock specs in DT bindings.
  */
diff --git a/include/dt-bindings/clock/rockchip,rk808.h b/include/dt-bindings/clock/rockchip,rk808.h
index 1a873432f965c..75dabfc6adc14 100644
--- a/include/dt-bindings/clock/rockchip,rk808.h
+++ b/include/dt-bindings/clock/rockchip,rk808.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 /*
  * This header provides constants clk index RK808 pmic clkout
  */
diff --git a/include/dt-bindings/clock/ste-ab8500.h b/include/dt-bindings/clock/ste-ab8500.h
index 6731f1f00a844..fb42dd0cab5fc 100644
--- a/include/dt-bindings/clock/ste-ab8500.h
+++ b/include/dt-bindings/clock/ste-ab8500.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #ifndef __STE_CLK_AB8500_H__
 #define __STE_CLK_AB8500_H__
 
diff --git a/include/dt-bindings/clock/stih407-clks.h b/include/dt-bindings/clock/stih407-clks.h
index 082edd9badfa1..f0936c1337721 100644
--- a/include/dt-bindings/clock/stih407-clks.h
+++ b/include/dt-bindings/clock/stih407-clks.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 /*
  * This header provides constants clk index STMicroelectronics
  * STiH407 SoC.
diff --git a/include/dt-bindings/clock/stih410-clks.h b/include/dt-bindings/clock/stih410-clks.h
index 2097a4bbe155d..90cbe6154c390 100644
--- a/include/dt-bindings/clock/stih410-clks.h
+++ b/include/dt-bindings/clock/stih410-clks.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 /*
  * This header provides constants clk index STMicroelectronics
  * STiH410 SoC.
diff --git a/include/dt-bindings/clock/stih416-clks.h b/include/dt-bindings/clock/stih416-clks.h
index f9bdbd13568dd..74302278024ea 100644
--- a/include/dt-bindings/clock/stih416-clks.h
+++ b/include/dt-bindings/clock/stih416-clks.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 /*
  * This header provides constants clk index STMicroelectronics
  * STiH416 SoC.
diff --git a/include/dt-bindings/clock/stih418-clks.h b/include/dt-bindings/clock/stih418-clks.h
index b62aa0b20217e..0e7fba0c52b32 100644
--- a/include/dt-bindings/clock/stih418-clks.h
+++ b/include/dt-bindings/clock/stih418-clks.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 /*
  * This header provides constants clk index STMicroelectronics
  * STiH418 SoC.
diff --git a/include/dt-bindings/clock/tegra114-car.h b/include/dt-bindings/clock/tegra114-car.h
index ed5ca218c8573..bb5c2c999c059 100644
--- a/include/dt-bindings/clock/tegra114-car.h
+++ b/include/dt-bindings/clock/tegra114-car.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 /*
  * This header provides constants for binding nvidia,tegra114-car.
  *
diff --git a/include/dt-bindings/clock/tegra124-car-common.h b/include/dt-bindings/clock/tegra124-car-common.h
index 9352c7e2ce0ba..4331f1df6ebee 100644
--- a/include/dt-bindings/clock/tegra124-car-common.h
+++ b/include/dt-bindings/clock/tegra124-car-common.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 /*
  * This header provides constants for binding nvidia,tegra124-car or
  * nvidia,tegra132-car.
diff --git a/include/dt-bindings/clock/tegra124-car.h b/include/dt-bindings/clock/tegra124-car.h
index 2860737f04436..c520ee2319509 100644
--- a/include/dt-bindings/clock/tegra124-car.h
+++ b/include/dt-bindings/clock/tegra124-car.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 /*
  * This header provides Tegra124-specific constants for binding
  * nvidia,tegra124-car.
diff --git a/include/dt-bindings/clock/tegra186-clock.h b/include/dt-bindings/clock/tegra186-clock.h
index f73d32098f992..d6b525f4566fa 100644
--- a/include/dt-bindings/clock/tegra186-clock.h
+++ b/include/dt-bindings/clock/tegra186-clock.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 /** @file */
 
 #ifndef _MACH_T186_CLK_T186_H
diff --git a/include/dt-bindings/clock/tegra20-car.h b/include/dt-bindings/clock/tegra20-car.h
index 04500b243a4d8..b21a0eb329214 100644
--- a/include/dt-bindings/clock/tegra20-car.h
+++ b/include/dt-bindings/clock/tegra20-car.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 /*
  * This header provides constants for binding nvidia,tegra20-car.
  *
diff --git a/include/dt-bindings/clock/tegra210-car.h b/include/dt-bindings/clock/tegra210-car.h
index 46689cd3750bf..a9dc1457cb006 100644
--- a/include/dt-bindings/clock/tegra210-car.h
+++ b/include/dt-bindings/clock/tegra210-car.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 /*
  * This header provides constants for binding nvidia,tegra210-car.
  *
diff --git a/include/dt-bindings/clock/tegra30-car.h b/include/dt-bindings/clock/tegra30-car.h
index 7213354b9652c..3c90f1535551a 100644
--- a/include/dt-bindings/clock/tegra30-car.h
+++ b/include/dt-bindings/clock/tegra30-car.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 /*
  * This header provides constants for binding nvidia,tegra30-car.
  *