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>

58 files changed, 58 insertions, 0 deletions

diff --git a/tools/lib/api/Makefile b/tools/lib/api/Makefile
index 1e83e3c074484..a13e9c7f1fc50 100644
--- a/tools/lib/api/Makefile
+++ b/tools/lib/api/Makefile
@@ -1,3 +1,4 @@
+# SPDX-License-Identifier: GPL-2.0
 include ../../scripts/Makefile.include
 include ../../scripts/utilities.mak		# QUIET_CLEAN
 
diff --git a/tools/lib/api/cpu.c b/tools/lib/api/cpu.c
index 8c6489356e3ac..4af6d4b7aa075 100644
--- a/tools/lib/api/cpu.c
+++ b/tools/lib/api/cpu.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #include <stdio.h>
 
 #include "cpu.h"
diff --git a/tools/lib/api/cpu.h b/tools/lib/api/cpu.h
index 81e9d3955961e..90a102fb20ded 100644
--- a/tools/lib/api/cpu.h
+++ b/tools/lib/api/cpu.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #ifndef __API_CPU__
 #define __API_CPU__
 
diff --git a/tools/lib/api/debug-internal.h b/tools/lib/api/debug-internal.h
index 188f7880eafe6..80c783497d25b 100644
--- a/tools/lib/api/debug-internal.h
+++ b/tools/lib/api/debug-internal.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #ifndef __API_DEBUG_INTERNAL_H__
 #define __API_DEBUG_INTERNAL_H__
 
diff --git a/tools/lib/api/debug.c b/tools/lib/api/debug.c
index 5fa5cf500a1f9..69b1ba3d1ee38 100644
--- a/tools/lib/api/debug.c
+++ b/tools/lib/api/debug.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #include <stdio.h>
 #include <stdarg.h>
 #include "debug.h"
diff --git a/tools/lib/api/debug.h b/tools/lib/api/debug.h
index a0872f68fc56b..3684dd6e0c02d 100644
--- a/tools/lib/api/debug.h
+++ b/tools/lib/api/debug.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #ifndef __API_DEBUG_H__
 #define __API_DEBUG_H__
 
diff --git a/tools/lib/api/fd/array.h b/tools/lib/api/fd/array.h
index 71287dddc05fb..b39557d1a88f9 100644
--- a/tools/lib/api/fd/array.h
+++ b/tools/lib/api/fd/array.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #ifndef __API_FD_ARRAY__
 #define __API_FD_ARRAY__
 
diff --git a/tools/lib/api/fs/fs.c b/tools/lib/api/fs/fs.c
index a7ecf8f469f47..b24afc0e6e81c 100644
--- a/tools/lib/api/fs/fs.c
+++ b/tools/lib/api/fs/fs.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #include <ctype.h>
 #include <errno.h>
 #include <limits.h>
diff --git a/tools/lib/api/fs/fs.h b/tools/lib/api/fs/fs.h
index 45605348461e2..dda49deefb521 100644
--- a/tools/lib/api/fs/fs.h
+++ b/tools/lib/api/fs/fs.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #ifndef __API_FS__
 #define __API_FS__
 
diff --git a/tools/lib/api/fs/tracing_path.c b/tools/lib/api/fs/tracing_path.c
index 3e606b9c443ef..7b7fd0b185510 100644
--- a/tools/lib/api/fs/tracing_path.c
+++ b/tools/lib/api/fs/tracing_path.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #ifndef _GNU_SOURCE
 # define _GNU_SOURCE
 #endif
diff --git a/tools/lib/api/fs/tracing_path.h b/tools/lib/api/fs/tracing_path.h
index 3f233ac70b6f7..0066f06cc3817 100644
--- a/tools/lib/api/fs/tracing_path.h
+++ b/tools/lib/api/fs/tracing_path.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #ifndef __API_FS_TRACING_PATH_H
 #define __API_FS_TRACING_PATH_H
 
diff --git a/tools/lib/bpf/Makefile b/tools/lib/bpf/Makefile
index d2441db34740d..4555304dc18e6 100644
--- a/tools/lib/bpf/Makefile
+++ b/tools/lib/bpf/Makefile
@@ -1,3 +1,4 @@
+# SPDX-License-Identifier: GPL-2.0
 # Most of this file is copied from tools/lib/traceevent/Makefile
 
 BPF_VERSION = 0
diff --git a/tools/lib/hweight.c b/tools/lib/hweight.c
index 0b859b8843390..a16ebf5154170 100644
--- a/tools/lib/hweight.c
+++ b/tools/lib/hweight.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #include <linux/bitops.h>
 #include <asm/types.h>
 
diff --git a/tools/lib/lockdep/Makefile b/tools/lib/lockdep/Makefile
index ed9ace59d1120..9b0ca3ad1ef38 100644
--- a/tools/lib/lockdep/Makefile
+++ b/tools/lib/lockdep/Makefile
@@ -1,3 +1,4 @@
+# SPDX-License-Identifier: GPL-2.0
 # file format version
 FILE_VERSION = 1
 
diff --git a/tools/lib/lockdep/common.c b/tools/lib/lockdep/common.c
index d1c89cc06f5f6..5c3b58cce8a9b 100644
--- a/tools/lib/lockdep/common.c
+++ b/tools/lib/lockdep/common.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #include <stddef.h>
 #include <stdbool.h>
 #include <linux/compiler.h>
diff --git a/tools/lib/lockdep/include/liblockdep/common.h b/tools/lib/lockdep/include/liblockdep/common.h
index 6e66277ec4375..8862da80995a8 100644
--- a/tools/lib/lockdep/include/liblockdep/common.h
+++ b/tools/lib/lockdep/include/liblockdep/common.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #ifndef _LIBLOCKDEP_COMMON_H
 #define _LIBLOCKDEP_COMMON_H
 
diff --git a/tools/lib/lockdep/include/liblockdep/mutex.h b/tools/lib/lockdep/include/liblockdep/mutex.h
index ee53a42818cae..a80ac39f966ed 100644
--- a/tools/lib/lockdep/include/liblockdep/mutex.h
+++ b/tools/lib/lockdep/include/liblockdep/mutex.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #ifndef _LIBLOCKDEP_MUTEX_H
 #define _LIBLOCKDEP_MUTEX_H
 
diff --git a/tools/lib/lockdep/include/liblockdep/rwlock.h b/tools/lib/lockdep/include/liblockdep/rwlock.h
index 4ec03f8615516..a96c3bf0fef12 100644
--- a/tools/lib/lockdep/include/liblockdep/rwlock.h
+++ b/tools/lib/lockdep/include/liblockdep/rwlock.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #ifndef _LIBLOCKDEP_RWLOCK_H
 #define _LIBLOCKDEP_RWLOCK_H
 
diff --git a/tools/lib/lockdep/lockdep.c b/tools/lib/lockdep/lockdep.c
index ced6d7443cea2..6002fcf2f9bc3 100644
--- a/tools/lib/lockdep/lockdep.c
+++ b/tools/lib/lockdep/lockdep.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #include <linux/lockdep.h>
 #include <stdlib.h>
 
diff --git a/tools/lib/lockdep/preload.c b/tools/lib/lockdep/preload.c
index 6a2d3c5d4e92b..76245d16196de 100644
--- a/tools/lib/lockdep/preload.c
+++ b/tools/lib/lockdep/preload.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #define _GNU_SOURCE
 #include <pthread.h>
 #include <stdio.h>
diff --git a/tools/lib/lockdep/run_tests.sh b/tools/lib/lockdep/run_tests.sh
index f9b94098fc98e..2e570a188f167 100755
--- a/tools/lib/lockdep/run_tests.sh
+++ b/tools/lib/lockdep/run_tests.sh
@@ -1,4 +1,5 @@
 #! /bin/bash
+# SPDX-License-Identifier: GPL-2.0
 
 make &> /dev/null
 
diff --git a/tools/lib/lockdep/tests/AA.c b/tools/lib/lockdep/tests/AA.c
index 18211a5f354fe..63c7ce97bda3a 100644
--- a/tools/lib/lockdep/tests/AA.c
+++ b/tools/lib/lockdep/tests/AA.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #include <liblockdep/mutex.h>
 
 int main(void)
diff --git a/tools/lib/lockdep/tests/ABA.c b/tools/lib/lockdep/tests/ABA.c
index 0f782ff404ac6..efa39b23f05d0 100644
--- a/tools/lib/lockdep/tests/ABA.c
+++ b/tools/lib/lockdep/tests/ABA.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #include <liblockdep/mutex.h>
 
 void main(void)
diff --git a/tools/lib/lockdep/tests/ABBA.c b/tools/lib/lockdep/tests/ABBA.c
index 07f0e29d54859..1460afd33d712 100644
--- a/tools/lib/lockdep/tests/ABBA.c
+++ b/tools/lib/lockdep/tests/ABBA.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #include <liblockdep/mutex.h>
 #include "common.h"
 
diff --git a/tools/lib/lockdep/tests/ABBA_2threads.c b/tools/lib/lockdep/tests/ABBA_2threads.c
index cd807d7363611..39325ef8a2ac1 100644
--- a/tools/lib/lockdep/tests/ABBA_2threads.c
+++ b/tools/lib/lockdep/tests/ABBA_2threads.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #include <stdio.h>
 #include <pthread.h>
 
diff --git a/tools/lib/lockdep/tests/ABBCCA.c b/tools/lib/lockdep/tests/ABBCCA.c
index 843db09ac666c..a54c1b2af1182 100644
--- a/tools/lib/lockdep/tests/ABBCCA.c
+++ b/tools/lib/lockdep/tests/ABBCCA.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #include <liblockdep/mutex.h>
 #include "common.h"
 
diff --git a/tools/lib/lockdep/tests/ABBCCDDA.c b/tools/lib/lockdep/tests/ABBCCDDA.c
index 33620e268f85f..aa5d194e88694 100644
--- a/tools/lib/lockdep/tests/ABBCCDDA.c
+++ b/tools/lib/lockdep/tests/ABBCCDDA.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #include <liblockdep/mutex.h>
 #include "common.h"
 
diff --git a/tools/lib/lockdep/tests/ABCABC.c b/tools/lib/lockdep/tests/ABCABC.c
index 3fee51e3a68a5..b54a08e60416f 100644
--- a/tools/lib/lockdep/tests/ABCABC.c
+++ b/tools/lib/lockdep/tests/ABCABC.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #include <liblockdep/mutex.h>
 #include "common.h"
 
diff --git a/tools/lib/lockdep/tests/ABCDBCDA.c b/tools/lib/lockdep/tests/ABCDBCDA.c
index 427ba562c75b0..a56742250d86f 100644
--- a/tools/lib/lockdep/tests/ABCDBCDA.c
+++ b/tools/lib/lockdep/tests/ABCDBCDA.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #include <liblockdep/mutex.h>
 #include "common.h"
 
diff --git a/tools/lib/lockdep/tests/ABCDBDDA.c b/tools/lib/lockdep/tests/ABCDBDDA.c
index 680c6cf3e919c..238a3353f3c35 100644
--- a/tools/lib/lockdep/tests/ABCDBDDA.c
+++ b/tools/lib/lockdep/tests/ABCDBDDA.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #include <liblockdep/mutex.h>
 #include "common.h"
 
diff --git a/tools/lib/lockdep/tests/WW.c b/tools/lib/lockdep/tests/WW.c
index d44f77d710298..eee88df7fc41b 100644
--- a/tools/lib/lockdep/tests/WW.c
+++ b/tools/lib/lockdep/tests/WW.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #include <liblockdep/rwlock.h>
 
 void main(void)
diff --git a/tools/lib/lockdep/tests/common.h b/tools/lib/lockdep/tests/common.h
index d89e94d47d86c..3026c29ccb5c3 100644
--- a/tools/lib/lockdep/tests/common.h
+++ b/tools/lib/lockdep/tests/common.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #ifndef _LIBLOCKDEP_TEST_COMMON_H
 #define _LIBLOCKDEP_TEST_COMMON_H
 
diff --git a/tools/lib/lockdep/tests/unlock_balance.c b/tools/lib/lockdep/tests/unlock_balance.c
index 0bc62de686f7b..34cf32f689de0 100644
--- a/tools/lib/lockdep/tests/unlock_balance.c
+++ b/tools/lib/lockdep/tests/unlock_balance.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #include <liblockdep/mutex.h>
 
 void main(void)
diff --git a/tools/lib/str_error_r.c b/tools/lib/str_error_r.c
index 503ae072244cb..d6d65537b0d9b 100644
--- a/tools/lib/str_error_r.c
+++ b/tools/lib/str_error_r.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #undef _GNU_SOURCE
 #include <string.h>
 #include <stdio.h>
diff --git a/tools/lib/string.c b/tools/lib/string.c
index a4246f14ded10..93b3d4b6feac3 100644
--- a/tools/lib/string.c
+++ b/tools/lib/string.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 /*
  *  linux/tools/lib/string.c
  *
diff --git a/tools/lib/subcmd/Makefile b/tools/lib/subcmd/Makefile
index 7e9f03c97e4c6..95563b8e1ad74 100644
--- a/tools/lib/subcmd/Makefile
+++ b/tools/lib/subcmd/Makefile
@@ -1,3 +1,4 @@
+# SPDX-License-Identifier: GPL-2.0
 include ../../scripts/Makefile.include
 include ../../scripts/utilities.mak		# QUIET_CLEAN
 
diff --git a/tools/lib/subcmd/exec-cmd.c b/tools/lib/subcmd/exec-cmd.c
index 1ae833af1a4af..33e94fb839867 100644
--- a/tools/lib/subcmd/exec-cmd.c
+++ b/tools/lib/subcmd/exec-cmd.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #include <linux/compiler.h>
 #include <linux/string.h>
 #include <sys/types.h>
diff --git a/tools/lib/subcmd/exec-cmd.h b/tools/lib/subcmd/exec-cmd.h
index 5d08bda31d90f..aba591b8d2548 100644
--- a/tools/lib/subcmd/exec-cmd.h
+++ b/tools/lib/subcmd/exec-cmd.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #ifndef __SUBCMD_EXEC_CMD_H
 #define __SUBCMD_EXEC_CMD_H
 
diff --git a/tools/lib/subcmd/help.c b/tools/lib/subcmd/help.c
index 0310520f918e4..2859f107abc80 100644
--- a/tools/lib/subcmd/help.c
+++ b/tools/lib/subcmd/help.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tools/lib/subcmd/help.h b/tools/lib/subcmd/help.h
index 9bd4223dc7220..355c066c8d49c 100644
--- a/tools/lib/subcmd/help.h
+++ b/tools/lib/subcmd/help.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #ifndef __SUBCMD_HELP_H
 #define __SUBCMD_HELP_H
 
diff --git a/tools/lib/subcmd/pager.c b/tools/lib/subcmd/pager.c
index 6518bea926d6f..5ba754d179520 100644
--- a/tools/lib/subcmd/pager.c
+++ b/tools/lib/subcmd/pager.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #include <sys/select.h>
 #include <stdlib.h>
 #include <stdio.h>
diff --git a/tools/lib/subcmd/pager.h b/tools/lib/subcmd/pager.h
index 623f5542d05de..f1a53cf298804 100644
--- a/tools/lib/subcmd/pager.h
+++ b/tools/lib/subcmd/pager.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #ifndef __SUBCMD_PAGER_H
 #define __SUBCMD_PAGER_H
 
diff --git a/tools/lib/subcmd/parse-options.c b/tools/lib/subcmd/parse-options.c
index 2bd6fd0c1d40d..f6a1babcbac41 100644
--- a/tools/lib/subcmd/parse-options.c
+++ b/tools/lib/subcmd/parse-options.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #include <linux/compiler.h>
 #include <linux/string.h>
 #include <linux/types.h>
diff --git a/tools/lib/subcmd/parse-options.h b/tools/lib/subcmd/parse-options.h
index f054ca1b899df..92fdbe1519f6d 100644
--- a/tools/lib/subcmd/parse-options.h
+++ b/tools/lib/subcmd/parse-options.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #ifndef __SUBCMD_PARSE_OPTIONS_H
 #define __SUBCMD_PARSE_OPTIONS_H
 
diff --git a/tools/lib/subcmd/run-command.c b/tools/lib/subcmd/run-command.c
index 911f83942723a..5cdac21625322 100644
--- a/tools/lib/subcmd/run-command.c
+++ b/tools/lib/subcmd/run-command.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #include <unistd.h>
 #include <sys/types.h>
 #include <sys/stat.h>
diff --git a/tools/lib/subcmd/run-command.h b/tools/lib/subcmd/run-command.h
index fe2befea1e730..17d969c6add3b 100644
--- a/tools/lib/subcmd/run-command.h
+++ b/tools/lib/subcmd/run-command.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #ifndef __SUBCMD_RUN_COMMAND_H
 #define __SUBCMD_RUN_COMMAND_H
 
diff --git a/tools/lib/subcmd/sigchain.c b/tools/lib/subcmd/sigchain.c
index 3537c348a18ef..f0fe3dbef7f7f 100644
--- a/tools/lib/subcmd/sigchain.c
+++ b/tools/lib/subcmd/sigchain.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #include <signal.h>
 #include "subcmd-util.h"
 #include "sigchain.h"
diff --git a/tools/lib/subcmd/sigchain.h b/tools/lib/subcmd/sigchain.h
index 0c919f2874ca3..1ec663af43eaf 100644
--- a/tools/lib/subcmd/sigchain.h
+++ b/tools/lib/subcmd/sigchain.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #ifndef __SUBCMD_SIGCHAIN_H
 #define __SUBCMD_SIGCHAIN_H
 
diff --git a/tools/lib/subcmd/subcmd-config.c b/tools/lib/subcmd/subcmd-config.c
index d017c728bd1b3..84a7cf6c7878a 100644
--- a/tools/lib/subcmd/subcmd-config.c
+++ b/tools/lib/subcmd/subcmd-config.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #include "subcmd-config.h"
 
 #define UNDEFINED "SUBCMD_HAS_NOT_BEEN_INITIALIZED"
diff --git a/tools/lib/subcmd/subcmd-config.h b/tools/lib/subcmd/subcmd-config.h
index cc8514030b5c3..9024dc17d1001 100644
--- a/tools/lib/subcmd/subcmd-config.h
+++ b/tools/lib/subcmd/subcmd-config.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #ifndef __PERF_SUBCMD_CONFIG_H
 #define __PERF_SUBCMD_CONFIG_H
 
diff --git a/tools/lib/subcmd/subcmd-util.h b/tools/lib/subcmd/subcmd-util.h
index 8fa5f036eff08..794a375dad360 100644
--- a/tools/lib/subcmd/subcmd-util.h
+++ b/tools/lib/subcmd/subcmd-util.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #ifndef __SUBCMD_UTIL_H
 #define __SUBCMD_UTIL_H
 
diff --git a/tools/lib/symbol/kallsyms.c b/tools/lib/symbol/kallsyms.c
index d270ac00613d6..914cb8e3d40b7 100644
--- a/tools/lib/symbol/kallsyms.c
+++ b/tools/lib/symbol/kallsyms.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #include <ctype.h>
 #include "symbol/kallsyms.h"
 #include <stdio.h>
diff --git a/tools/lib/symbol/kallsyms.h b/tools/lib/symbol/kallsyms.h
index 4071316a766ef..bc40101d72c18 100644
--- a/tools/lib/symbol/kallsyms.h
+++ b/tools/lib/symbol/kallsyms.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #ifndef __TOOLS_KALLSYMS_H_
 #define __TOOLS_KALLSYMS_H_ 1
 
diff --git a/tools/lib/traceevent/Makefile b/tools/lib/traceevent/Makefile
index 9b8555ea3459c..46cd5f871ad76 100644
--- a/tools/lib/traceevent/Makefile
+++ b/tools/lib/traceevent/Makefile
@@ -1,3 +1,4 @@
+# SPDX-License-Identifier: GPL-2.0
 # trace-cmd version
 EP_VERSION = 1
 EP_PATCHLEVEL = 1
diff --git a/tools/lib/traceevent/plugin_cfg80211.c b/tools/lib/traceevent/plugin_cfg80211.c
index ec57d0c1fbc2b..8f8586912da7b 100644
--- a/tools/lib/traceevent/plugin_cfg80211.c
+++ b/tools/lib/traceevent/plugin_cfg80211.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #include <stdio.h>
 #include <string.h>
 #include <inttypes.h>
diff --git a/tools/lib/traceevent/plugin_scsi.c b/tools/lib/traceevent/plugin_scsi.c
index 3727de48c8d50..5e750af2b461f 100644
--- a/tools/lib/traceevent/plugin_scsi.c
+++ b/tools/lib/traceevent/plugin_scsi.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #include <stdio.h>
 #include <string.h>
 #include <inttypes.h>
diff --git a/tools/lib/traceevent/plugin_xen.c b/tools/lib/traceevent/plugin_xen.c
index 3a413eaada684..690173bfa13ed 100644
--- a/tools/lib/traceevent/plugin_xen.c
+++ b/tools/lib/traceevent/plugin_xen.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tools/lib/vsprintf.c b/tools/lib/vsprintf.c
index 45f9a06daa560..e08ee147eab43 100644
--- a/tools/lib/vsprintf.c
+++ b/tools/lib/vsprintf.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #include <sys/types.h>
 #include <linux/kernel.h>
 #include <stdio.h>