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/arch/cris/include/arch-v10/arch/bitops.h b/arch/cris/include/arch-v10/arch/bitops.h
index 03d9cfd92c8a..c18f81858899 100644
--- a/arch/cris/include/arch-v10/arch/bitops.h
+++ b/arch/cris/include/arch-v10/arch/bitops.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 /* asm/arch/bitops.h for Linux/CRISv10 */
 
 #ifndef _CRIS_ARCH_BITOPS_H
diff --git a/arch/cris/include/arch-v10/arch/bug.h b/arch/cris/include/arch-v10/arch/bug.h
index 3485d6b34bb0..905afeacfedf 100644
--- a/arch/cris/include/arch-v10/arch/bug.h
+++ b/arch/cris/include/arch-v10/arch/bug.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #ifndef __ASM_CRISv10_ARCH_BUG_H
 #define __ASM_CRISv10_ARCH_BUG_H
 
diff --git a/arch/cris/include/arch-v10/arch/cache.h b/arch/cris/include/arch-v10/arch/cache.h
index aea27184d2d2..d4049bcab3c5 100644
--- a/arch/cris/include/arch-v10/arch/cache.h
+++ b/arch/cris/include/arch-v10/arch/cache.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #ifndef _ASM_ARCH_CACHE_H
 #define _ASM_ARCH_CACHE_H
 
diff --git a/arch/cris/include/arch-v10/arch/checksum.h b/arch/cris/include/arch-v10/arch/checksum.h
index d1d1bd9e1090..eb186be4fb32 100644
--- a/arch/cris/include/arch-v10/arch/checksum.h
+++ b/arch/cris/include/arch-v10/arch/checksum.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #ifndef _CRIS_ARCH_CHECKSUM_H
 #define _CRIS_ARCH_CHECKSUM_H
 
diff --git a/arch/cris/include/arch-v10/arch/delay.h b/arch/cris/include/arch-v10/arch/delay.h
index 39481f6e0c30..a57d2cc0baf7 100644
--- a/arch/cris/include/arch-v10/arch/delay.h
+++ b/arch/cris/include/arch-v10/arch/delay.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #ifndef _CRIS_ARCH_DELAY_H
 #define _CRIS_ARCH_DELAY_H
 
diff --git a/arch/cris/include/arch-v10/arch/dma.h b/arch/cris/include/arch-v10/arch/dma.h
index ecb9dba6fa4f..ea794a32cf5e 100644
--- a/arch/cris/include/arch-v10/arch/dma.h
+++ b/arch/cris/include/arch-v10/arch/dma.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 /* Defines for using and allocating dma channels. */
 
 #ifndef _ASM_ARCH_DMA_H
diff --git a/arch/cris/include/arch-v10/arch/io.h b/arch/cris/include/arch-v10/arch/io.h
index 4a724172877f..bae5f77cfabc 100644
--- a/arch/cris/include/arch-v10/arch/io.h
+++ b/arch/cris/include/arch-v10/arch/io.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #ifndef _ASM_ARCH_CRIS_IO_H
 #define _ASM_ARCH_CRIS_IO_H
 
diff --git a/arch/cris/include/arch-v10/arch/io_interface_mux.h b/arch/cris/include/arch-v10/arch/io_interface_mux.h
index d92500080883..2d5617e67ab0 100644
--- a/arch/cris/include/arch-v10/arch/io_interface_mux.h
+++ b/arch/cris/include/arch-v10/arch/io_interface_mux.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 /* IO interface mux allocator for ETRAX100LX.
  * Copyright 2004, Axis Communications AB
  * $Id: io_interface_mux.h,v 1.1 2004/12/13 12:21:53 starvik Exp $
diff --git a/arch/cris/include/arch-v10/arch/irq.h b/arch/cris/include/arch-v10/arch/irq.h
index 6aecb835037d..c4e8a78e33d1 100644
--- a/arch/cris/include/arch-v10/arch/irq.h
+++ b/arch/cris/include/arch-v10/arch/irq.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 /*
  * Interrupt handling assembler and defines for Linux/CRISv10
  */
diff --git a/arch/cris/include/arch-v10/arch/irqflags.h b/arch/cris/include/arch-v10/arch/irqflags.h
index 75ef18991240..9959b0a8a58c 100644
--- a/arch/cris/include/arch-v10/arch/irqflags.h
+++ b/arch/cris/include/arch-v10/arch/irqflags.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #ifndef __ASM_CRIS_ARCH_IRQFLAGS_H
 #define __ASM_CRIS_ARCH_IRQFLAGS_H
 
diff --git a/arch/cris/include/arch-v10/arch/memmap.h b/arch/cris/include/arch-v10/arch/memmap.h
index 13f3b971407f..b6b171f48b29 100644
--- a/arch/cris/include/arch-v10/arch/memmap.h
+++ b/arch/cris/include/arch-v10/arch/memmap.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #ifndef _ASM_ARCH_MEMMAP_H
 #define _ASM_ARCH_MEMMAP_H
 
diff --git a/arch/cris/include/arch-v10/arch/mmu.h b/arch/cris/include/arch-v10/arch/mmu.h
index 47a5dd21749d..74c53048be79 100644
--- a/arch/cris/include/arch-v10/arch/mmu.h
+++ b/arch/cris/include/arch-v10/arch/mmu.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 /*
  * CRIS MMU constants and PTE layout
  */
diff --git a/arch/cris/include/arch-v10/arch/offset.h b/arch/cris/include/arch-v10/arch/offset.h
index 675b51d85639..6f0f2b4a163f 100644
--- a/arch/cris/include/arch-v10/arch/offset.h
+++ b/arch/cris/include/arch-v10/arch/offset.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #ifndef __ASM_OFFSETS_H__
 #define __ASM_OFFSETS_H__
 /*
diff --git a/arch/cris/include/arch-v10/arch/page.h b/arch/cris/include/arch-v10/arch/page.h
index ffafc99c3472..a4bbff64868c 100644
--- a/arch/cris/include/arch-v10/arch/page.h
+++ b/arch/cris/include/arch-v10/arch/page.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #ifndef _CRIS_ARCH_PAGE_H
 #define _CRIS_ARCH_PAGE_H
 
diff --git a/arch/cris/include/arch-v10/arch/pgtable.h b/arch/cris/include/arch-v10/arch/pgtable.h
index 2a2576d1fc97..a61532d06acb 100644
--- a/arch/cris/include/arch-v10/arch/pgtable.h
+++ b/arch/cris/include/arch-v10/arch/pgtable.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #ifndef _CRIS_ARCH_PGTABLE_H
 #define _CRIS_ARCH_PGTABLE_H
 
diff --git a/arch/cris/include/arch-v10/arch/processor.h b/arch/cris/include/arch-v10/arch/processor.h
index 93feb2a487d8..b2df646bc1eb 100644
--- a/arch/cris/include/arch-v10/arch/processor.h
+++ b/arch/cris/include/arch-v10/arch/processor.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #ifndef __ASM_CRIS_ARCH_PROCESSOR_H
 #define __ASM_CRIS_ARCH_PROCESSOR_H
 
diff --git a/arch/cris/include/arch-v10/arch/swab.h b/arch/cris/include/arch-v10/arch/swab.h
index e4e847d8a05e..8cc27dfb9d3a 100644
--- a/arch/cris/include/arch-v10/arch/swab.h
+++ b/arch/cris/include/arch-v10/arch/swab.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #ifndef _CRIS_ARCH_SWAB_H
 #define _CRIS_ARCH_SWAB_H
 
diff --git a/arch/cris/include/arch-v10/arch/system.h b/arch/cris/include/arch-v10/arch/system.h
index 9b5580f58b96..4c63f728122b 100644
--- a/arch/cris/include/arch-v10/arch/system.h
+++ b/arch/cris/include/arch-v10/arch/system.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #ifndef __ASM_CRIS_ARCH_SYSTEM_H
 #define __ASM_CRIS_ARCH_SYSTEM_H
 
diff --git a/arch/cris/include/arch-v10/arch/thread_info.h b/arch/cris/include/arch-v10/arch/thread_info.h
index 218f4152d3e5..0ef1223998c1 100644
--- a/arch/cris/include/arch-v10/arch/thread_info.h
+++ b/arch/cris/include/arch-v10/arch/thread_info.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #ifndef _ASM_ARCH_THREAD_INFO_H
 #define _ASM_ARCH_THREAD_INFO_H
 
diff --git a/arch/cris/include/arch-v10/arch/timex.h b/arch/cris/include/arch-v10/arch/timex.h
index e48447d94faf..9c9583e5aed6 100644
--- a/arch/cris/include/arch-v10/arch/timex.h
+++ b/arch/cris/include/arch-v10/arch/timex.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 /*
  * Use prescale timer at 25000 Hz instead of the baudrate timer at 
  * 19200 to get rid of the 64ppm to fast timer (and we get better 
diff --git a/arch/cris/include/arch-v10/arch/tlb.h b/arch/cris/include/arch-v10/arch/tlb.h
index 31525bbe75c3..9f039d83f21b 100644
--- a/arch/cris/include/arch-v10/arch/tlb.h
+++ b/arch/cris/include/arch-v10/arch/tlb.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #ifndef _CRIS_ARCH_TLB_H
 #define _CRIS_ARCH_TLB_H
 
diff --git a/arch/cris/include/arch-v10/arch/uaccess.h b/arch/cris/include/arch-v10/arch/uaccess.h
index 5477c98c2281..8d033c534f1f 100644
--- a/arch/cris/include/arch-v10/arch/uaccess.h
+++ b/arch/cris/include/arch-v10/arch/uaccess.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 /* 
  * Authors:    Bjorn Wesen (bjornw@axis.com)
  *	       Hans-Peter Nilsson (hp@axis.com)
diff --git a/arch/cris/include/arch-v10/arch/unistd.h b/arch/cris/include/arch-v10/arch/unistd.h
index d1a38b9e6264..03cd0b8652f4 100644
--- a/arch/cris/include/arch-v10/arch/unistd.h
+++ b/arch/cris/include/arch-v10/arch/unistd.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #ifndef _ASM_CRIS_ARCH_UNISTD_H_
 #define _ASM_CRIS_ARCH_UNISTD_H_