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>

53 files changed, 53 insertions, 0 deletions

diff --git a/tools/perf/tests/attr.c b/tools/perf/tests/attr.c
index c9aafed7da15..c180bbcdbef6 100644
--- a/tools/perf/tests/attr.c
+++ b/tools/perf/tests/attr.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 /*
  * The struct perf_event_attr test support.
  *
diff --git a/tools/perf/tests/attr.py b/tools/perf/tests/attr.py
index 6bb50e82a3e3..907b1b2f56ad 100644
--- a/tools/perf/tests/attr.py
+++ b/tools/perf/tests/attr.py
@@ -1,4 +1,5 @@
 #! /usr/bin/python
+# SPDX-License-Identifier: GPL-2.0
 
 import os
 import sys
diff --git a/tools/perf/tests/backward-ring-buffer.c b/tools/perf/tests/backward-ring-buffer.c
index d233ad336463..71b9a0b613d2 100644
--- a/tools/perf/tests/backward-ring-buffer.c
+++ b/tools/perf/tests/backward-ring-buffer.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 /*
  * Test backward bit in event attribute, read ring buffer from end to
  * beginning
diff --git a/tools/perf/tests/bitmap.c b/tools/perf/tests/bitmap.c
index 0d7c06584905..47bedf25ba69 100644
--- a/tools/perf/tests/bitmap.c
+++ b/tools/perf/tests/bitmap.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #include <linux/compiler.h>
 #include <linux/bitmap.h>
 #include "tests.h"
diff --git a/tools/perf/tests/bp_signal.c b/tools/perf/tests/bp_signal.c
index 97937e1bc53a..335b695f4970 100644
--- a/tools/perf/tests/bp_signal.c
+++ b/tools/perf/tests/bp_signal.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 /*
  * Inspired by breakpoint overflow test done by
  * Vince Weaver <vincent.weaver@maine.edu> for perf_event_tests
diff --git a/tools/perf/tests/bp_signal_overflow.c b/tools/perf/tests/bp_signal_overflow.c
index 61ecd8021f49..ca962559e845 100644
--- a/tools/perf/tests/bp_signal_overflow.c
+++ b/tools/perf/tests/bp_signal_overflow.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 /*
  * Originally done by Vince Weaver <vincent.weaver@maine.edu> for
  * perf_event_tests (git://github.com/deater/perf_event_tests)
diff --git a/tools/perf/tests/builtin-test.c b/tools/perf/tests/builtin-test.c
index 377bea009163..53d06f37406a 100644
--- a/tools/perf/tests/builtin-test.c
+++ b/tools/perf/tests/builtin-test.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 /*
  * builtin-test.c
  *
diff --git a/tools/perf/tests/clang.c b/tools/perf/tests/clang.c
index c60ec916f0f2..f45fe11dcf50 100644
--- a/tools/perf/tests/clang.c
+++ b/tools/perf/tests/clang.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #include "tests.h"
 #include "debug.h"
 #include "util.h"
diff --git a/tools/perf/tests/code-reading.c b/tools/perf/tests/code-reading.c
index 466a462b26d1..fcc8984bc329 100644
--- a/tools/perf/tests/code-reading.c
+++ b/tools/perf/tests/code-reading.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #include <errno.h>
 #include <linux/kernel.h>
 #include <linux/types.h>
diff --git a/tools/perf/tests/cpumap.c b/tools/perf/tests/cpumap.c
index 199702252270..e78b897677bd 100644
--- a/tools/perf/tests/cpumap.c
+++ b/tools/perf/tests/cpumap.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #include "tests.h"
 #include <stdio.h>
 #include "cpumap.h"
diff --git a/tools/perf/tests/dso-data.c b/tools/perf/tests/dso-data.c
index 30aead42d136..7f6c52021e41 100644
--- a/tools/perf/tests/dso-data.c
+++ b/tools/perf/tests/dso-data.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #include <dirent.h>
 #include <stdlib.h>
 #include <linux/kernel.h>
diff --git a/tools/perf/tests/dwarf-unwind.c b/tools/perf/tests/dwarf-unwind.c
index 9ba1d216a89f..ac40e05bcab4 100644
--- a/tools/perf/tests/dwarf-unwind.c
+++ b/tools/perf/tests/dwarf-unwind.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #include <linux/compiler.h>
 #include <linux/types.h>
 #include <inttypes.h>
diff --git a/tools/perf/tests/event-times.c b/tools/perf/tests/event-times.c
index b82b981c3259..1a2686f1fcf0 100644
--- a/tools/perf/tests/event-times.c
+++ b/tools/perf/tests/event-times.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #include <linux/compiler.h>
 #include <errno.h>
 #include <inttypes.h>
diff --git a/tools/perf/tests/event_update.c b/tools/perf/tests/event_update.c
index 9484da2ec6b4..f14dcd613438 100644
--- a/tools/perf/tests/event_update.c
+++ b/tools/perf/tests/event_update.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #include <linux/compiler.h>
 #include "evlist.h"
 #include "evsel.h"
diff --git a/tools/perf/tests/evsel-roundtrip-name.c b/tools/perf/tests/evsel-roundtrip-name.c
index d32759b6e38a..a104728ebf25 100644
--- a/tools/perf/tests/evsel-roundtrip-name.c
+++ b/tools/perf/tests/evsel-roundtrip-name.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #include "evlist.h"
 #include "evsel.h"
 #include "parse-events.h"
diff --git a/tools/perf/tests/evsel-tp-sched.c b/tools/perf/tests/evsel-tp-sched.c
index 5fc906d26c5c..699561fa512c 100644
--- a/tools/perf/tests/evsel-tp-sched.c
+++ b/tools/perf/tests/evsel-tp-sched.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #include <linux/err.h>
 #include <traceevent/event-parse.h>
 #include "evsel.h"
diff --git a/tools/perf/tests/expr.c b/tools/perf/tests/expr.c
index cb251bf523e7..01f0706995a9 100644
--- a/tools/perf/tests/expr.c
+++ b/tools/perf/tests/expr.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #include "util/debug.h"
 #include "util/expr.h"
 #include "tests.h"
diff --git a/tools/perf/tests/fdarray.c b/tools/perf/tests/fdarray.c
index 7d3a9e2ff897..c7c81c4a5b2b 100644
--- a/tools/perf/tests/fdarray.c
+++ b/tools/perf/tests/fdarray.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #include <api/fd/array.h>
 #include <poll.h>
 #include "util/debug.h"
diff --git a/tools/perf/tests/hists_common.c b/tools/perf/tests/hists_common.c
index 00b8dc50f3db..f7c5b613d667 100644
--- a/tools/perf/tests/hists_common.c
+++ b/tools/perf/tests/hists_common.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #include <inttypes.h>
 #include "perf.h"
 #include "util/debug.h"
diff --git a/tools/perf/tests/hists_common.h b/tools/perf/tests/hists_common.h
index 888254e8665c..a2de0ff0ce3a 100644
--- a/tools/perf/tests/hists_common.h
+++ b/tools/perf/tests/hists_common.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #ifndef __PERF_TESTS__HISTS_COMMON_H__
 #define __PERF_TESTS__HISTS_COMMON_H__
 
diff --git a/tools/perf/tests/hists_cumulate.c b/tools/perf/tests/hists_cumulate.c
index 8d19c0200cb7..65fe02bebbee 100644
--- a/tools/perf/tests/hists_cumulate.c
+++ b/tools/perf/tests/hists_cumulate.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #include "perf.h"
 #include "util/debug.h"
 #include "util/event.h"
diff --git a/tools/perf/tests/hists_filter.c b/tools/perf/tests/hists_filter.c
index 755ca551b810..1c5bedab3c2c 100644
--- a/tools/perf/tests/hists_filter.c
+++ b/tools/perf/tests/hists_filter.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #include "perf.h"
 #include "util/debug.h"
 #include "util/symbol.h"
diff --git a/tools/perf/tests/hists_link.c b/tools/perf/tests/hists_link.c
index 073c9c2856bc..9a9d06cb0222 100644
--- a/tools/perf/tests/hists_link.c
+++ b/tools/perf/tests/hists_link.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #include "perf.h"
 #include "tests.h"
 #include "debug.h"
diff --git a/tools/perf/tests/hists_output.c b/tools/perf/tests/hists_output.c
index 282d62eaebe2..faacb4f41460 100644
--- a/tools/perf/tests/hists_output.c
+++ b/tools/perf/tests/hists_output.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #include "perf.h"
 #include "util/debug.h"
 #include "util/event.h"
diff --git a/tools/perf/tests/is_printable_array.c b/tools/perf/tests/is_printable_array.c
index 38f765767587..9c7b3baca4fe 100644
--- a/tools/perf/tests/is_printable_array.c
+++ b/tools/perf/tests/is_printable_array.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #include <linux/compiler.h>
 #include <linux/kernel.h>
 #include "tests.h"
diff --git a/tools/perf/tests/keep-tracking.c b/tools/perf/tests/keep-tracking.c
index 739428603b71..842d33637a18 100644
--- a/tools/perf/tests/keep-tracking.c
+++ b/tools/perf/tests/keep-tracking.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #include <linux/types.h>
 #include <unistd.h>
 #include <sys/prctl.h>
diff --git a/tools/perf/tests/kmod-path.c b/tools/perf/tests/kmod-path.c
index 8b9d4ba06c0e..8e57d46109de 100644
--- a/tools/perf/tests/kmod-path.c
+++ b/tools/perf/tests/kmod-path.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #include <stdbool.h>
 #include <stdlib.h>
 #include "tests.h"
diff --git a/tools/perf/tests/llvm.c b/tools/perf/tests/llvm.c
index 5187b50dbafe..a039f93199e5 100644
--- a/tools/perf/tests/llvm.c
+++ b/tools/perf/tests/llvm.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #include <stdio.h>
 #include <bpf/libbpf.h>
 #include <util/llvm-utils.h>
diff --git a/tools/perf/tests/llvm.h b/tools/perf/tests/llvm.h
index b83571758d83..f68b0d9b8ae2 100644
--- a/tools/perf/tests/llvm.h
+++ b/tools/perf/tests/llvm.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #ifndef PERF_TEST_LLVM_H
 #define PERF_TEST_LLVM_H
 
diff --git a/tools/perf/tests/mmap-basic.c b/tools/perf/tests/mmap-basic.c
index bc8a70ee46d8..5a8bf318f8a7 100644
--- a/tools/perf/tests/mmap-basic.c
+++ b/tools/perf/tests/mmap-basic.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #include <errno.h>
 #include <inttypes.h>
 /* For the CLR_() macros */
diff --git a/tools/perf/tests/mmap-thread-lookup.c b/tools/perf/tests/mmap-thread-lookup.c
index f94a4196e7c9..3c3f3e029e33 100644
--- a/tools/perf/tests/mmap-thread-lookup.c
+++ b/tools/perf/tests/mmap-thread-lookup.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #include <inttypes.h>
 #include <unistd.h>
 #include <sys/syscall.h>
diff --git a/tools/perf/tests/openat-syscall-all-cpus.c b/tools/perf/tests/openat-syscall-all-cpus.c
index 9cf1c35f2ad0..c531e6deb104 100644
--- a/tools/perf/tests/openat-syscall-all-cpus.c
+++ b/tools/perf/tests/openat-syscall-all-cpus.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #include <errno.h>
 #include <inttypes.h>
 /* For the CPU_* macros */
diff --git a/tools/perf/tests/openat-syscall-tp-fields.c b/tools/perf/tests/openat-syscall-tp-fields.c
index b6ee1c41f45d..d9619d265314 100644
--- a/tools/perf/tests/openat-syscall-tp-fields.c
+++ b/tools/perf/tests/openat-syscall-tp-fields.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #include <linux/err.h>
 #include "perf.h"
 #include "evlist.h"
diff --git a/tools/perf/tests/openat-syscall.c b/tools/perf/tests/openat-syscall.c
index 9dc5c5d37553..00cd63f90b92 100644
--- a/tools/perf/tests/openat-syscall.c
+++ b/tools/perf/tests/openat-syscall.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #include <errno.h>
 #include <inttypes.h>
 #include <api/fs/tracing_path.h>
diff --git a/tools/perf/tests/parse-events.c b/tools/perf/tests/parse-events.c
index 0f0b025faa4b..f0679613bd18 100644
--- a/tools/perf/tests/parse-events.c
+++ b/tools/perf/tests/parse-events.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #include "parse-events.h"
 #include "evsel.h"
 #include "evlist.h"
diff --git a/tools/perf/tests/parse-no-sample-id-all.c b/tools/perf/tests/parse-no-sample-id-all.c
index 91867dcc39f0..2196d1497c0c 100644
--- a/tools/perf/tests/parse-no-sample-id-all.c
+++ b/tools/perf/tests/parse-no-sample-id-all.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #include <linux/kernel.h>
 #include <linux/types.h>
 #include <stddef.h>
diff --git a/tools/perf/tests/perf-hooks.c b/tools/perf/tests/perf-hooks.c
index bf2517d6de70..a693bcf017ea 100644
--- a/tools/perf/tests/perf-hooks.c
+++ b/tools/perf/tests/perf-hooks.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #include <signal.h>
 #include <stdlib.h>
 
diff --git a/tools/perf/tests/perf-record.c b/tools/perf/tests/perf-record.c
index 19b650064b70..c34904d37705 100644
--- a/tools/perf/tests/perf-record.c
+++ b/tools/perf/tests/perf-record.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #include <errno.h>
 #include <inttypes.h>
 /* For the CLR_() macros */
diff --git a/tools/perf/tests/perf-targz-src-pkg b/tools/perf/tests/perf-targz-src-pkg
index f2d9c5fe58e0..fae26b1cf08f 100755
--- a/tools/perf/tests/perf-targz-src-pkg
+++ b/tools/perf/tests/perf-targz-src-pkg
@@ -1,4 +1,5 @@
 #!/bin/sh
+# SPDX-License-Identifier: GPL-2.0
 # Test one of the main kernel Makefile targets to generate a perf sources tarball
 # suitable for build outside the full kernel sources.
 #
diff --git a/tools/perf/tests/pmu.c b/tools/perf/tests/pmu.c
index 9f7f589f9c54..9abca267afa9 100644
--- a/tools/perf/tests/pmu.c
+++ b/tools/perf/tests/pmu.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #include "parse-events.h"
 #include "pmu.h"
 #include "util.h"
diff --git a/tools/perf/tests/python-use.c b/tools/perf/tests/python-use.c
index 598a7e058ad4..5d2df65ada6a 100644
--- a/tools/perf/tests/python-use.c
+++ b/tools/perf/tests/python-use.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 /*
  * Just test if we can load the python binding.
  */
diff --git a/tools/perf/tests/sample-parsing.c b/tools/perf/tests/sample-parsing.c
index c3858487159d..3ec6302b6498 100644
--- a/tools/perf/tests/sample-parsing.c
+++ b/tools/perf/tests/sample-parsing.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #include <stdbool.h>
 #include <inttypes.h>
 #include <linux/kernel.h>
diff --git a/tools/perf/tests/sdt.c b/tools/perf/tests/sdt.c
index a9903d9b8bc2..5059452d27dd 100644
--- a/tools/perf/tests/sdt.c
+++ b/tools/perf/tests/sdt.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #include <errno.h>
 #include <stdio.h>
 #include <sys/epoll.h>
diff --git a/tools/perf/tests/stat.c b/tools/perf/tests/stat.c
index 7f988a939036..94250024684a 100644
--- a/tools/perf/tests/stat.c
+++ b/tools/perf/tests/stat.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #include <linux/compiler.h>
 #include "event.h"
 #include "tests.h"
diff --git a/tools/perf/tests/sw-clock.c b/tools/perf/tests/sw-clock.c
index d88511f6072c..725a196991a8 100644
--- a/tools/perf/tests/sw-clock.c
+++ b/tools/perf/tests/sw-clock.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #include <errno.h>
 #include <inttypes.h>
 #include <unistd.h>
diff --git a/tools/perf/tests/switch-tracking.c b/tools/perf/tests/switch-tracking.c
index 2acd78555192..7d3f4bf9534f 100644
--- a/tools/perf/tests/switch-tracking.c
+++ b/tools/perf/tests/switch-tracking.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #include <sys/time.h>
 #include <sys/prctl.h>
 #include <errno.h>
diff --git a/tools/perf/tests/task-exit.c b/tools/perf/tests/task-exit.c
index f0881d0dd9c9..bc4a7344e274 100644
--- a/tools/perf/tests/task-exit.c
+++ b/tools/perf/tests/task-exit.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #include "evlist.h"
 #include "evsel.h"
 #include "thread_map.h"
diff --git a/tools/perf/tests/tests.h b/tools/perf/tests/tests.h
index 921412a6a880..2862b80bc288 100644
--- a/tools/perf/tests/tests.h
+++ b/tools/perf/tests/tests.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #ifndef TESTS_H
 #define TESTS_H
 
diff --git a/tools/perf/tests/thread-map.c b/tools/perf/tests/thread-map.c
index b3423c744f46..dbcb6a19b375 100644
--- a/tools/perf/tests/thread-map.c
+++ b/tools/perf/tests/thread-map.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #include <stdlib.h>
 #include <sys/types.h>
 #include <unistd.h>
diff --git a/tools/perf/tests/thread-mg-share.c b/tools/perf/tests/thread-mg-share.c
index b9c7f58db6c4..b1d1bbafe7ae 100644
--- a/tools/perf/tests/thread-mg-share.c
+++ b/tools/perf/tests/thread-mg-share.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #include "tests.h"
 #include "machine.h"
 #include "thread.h"
diff --git a/tools/perf/tests/topology.c b/tools/perf/tests/topology.c
index 19b0561fd6f6..a59db7c45a65 100644
--- a/tools/perf/tests/topology.c
+++ b/tools/perf/tests/topology.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #include <string.h>
 #include <stdlib.h>
 #include <stdio.h>
diff --git a/tools/perf/tests/unit_number__scnprintf.c b/tools/perf/tests/unit_number__scnprintf.c
index 15cd1cf8c129..2bb8cb0039c1 100644
--- a/tools/perf/tests/unit_number__scnprintf.c
+++ b/tools/perf/tests/unit_number__scnprintf.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #include <inttypes.h>
 #include <linux/compiler.h>
 #include <linux/types.h>
diff --git a/tools/perf/tests/vmlinux-kallsyms.c b/tools/perf/tests/vmlinux-kallsyms.c
index 86cb8868f67f..f6789fb029d6 100644
--- a/tools/perf/tests/vmlinux-kallsyms.c
+++ b/tools/perf/tests/vmlinux-kallsyms.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #include <linux/compiler.h>
 #include <linux/rbtree.h>
 #include <inttypes.h>