Merge branch 'tglx-license' into docs-next

Thomas said:

There are a few bogus SPDX identifiers in various files and SPDX
Identifiers used in tree or about to be used which have no corresponding
License Text file in the LICENSES directory or use the new variant of the
GPL-2.0[+] license identifiers which are not mentioned in the GPL-2.0
Valid-License-Identifiers: tags.

There is no tool which can be used to scan the tree and also nothing which
helps people who submit patches to check their stuff before submission.

The following series cleans that up:

 - Add GPL-2.0-only and GPL-2.0-or-later identifiers to the GPL2.0 license
   and the Linux-syscall-note exception

 - Add X11, Apache-2.0, CC-BY-SA-4.0, CCDL-1.0, Linux-OpenIB license texts
   to the LICENSES directory along with the required documentation texts

 - Add a checker script which can read a single file or even a patch from
   the command line or does a full git tree scan

[Thomas also wins some sort of special prize for including an SPDX-checking
patch that complains about itself!]

LICENSES/exceptions/Linux-syscall-note

@@ -1,6 +1,6 @@
 SPDX-Exception-Identifier: Linux-syscall-note
 SPDX-URL: https://spdx.org/licenses/Linux-syscall-note.html
-SPDX-Licenses: GPL-2.0, GPL-2.0+, GPL-1.0+, LGPL-2.0, LGPL-2.0+, LGPL-2.1, LGPL-2.1+
+SPDX-Licenses: GPL-2.0, GPL-2.0+, GPL-1.0+, LGPL-2.0, LGPL-2.0+, LGPL-2.1, LGPL-2.1+, GPL-2.0-only, GPL-2.0-or-later
 Usage-Guide:
   This exception is used together with one of the above SPDX-Licenses
   to mark user space API (uapi) header files so they can be included

LICENSES/other/Apache-2.0

@@ -0,0 +1,183 @@
+Valid-License-Identifier: Apache-2.0
+SPDX-URL: https://spdx.org/licenses/Apache-2.0.html
+Usage-Guide:
+  To use the Apache License version 2.0 put the following SPDX tag/value
+  pair into a comment according to the placement guidelines in the
+  licensing rules documentation:
+    SPDX-License-Identifier: Apache-2.0
+License-Text:
+
+Apache License
+
+Version 2.0, January 2004
+
+http://www.apache.org/licenses/
+
+TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
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LICENSES/other/CC-BY-SA-4.0

@@ -0,0 +1,397 @@
+Valid-License-Identifier: CC-BY-SA-4.0
+SPDX-URL: https://spdx.org/licenses/CC-BY-SA-4.0
+Usage-Guide:
+  To use the Creative Commons Attribution Share Alike 4.0 International
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+    SPDX-License-Identifier: CC-BY-SA-4.0
+License-Text:
+
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+authorize the use of the trademark "Creative Commons" or any other
+trademark or logo of Creative Commons without its prior written consent
+including, without limitation, in connection with any unauthorized
+modifications to any of its public licenses or any other arrangements,
+understandings, or agreements concerning use of licensed material. For the
+avoidance of doubt, this paragraph does not form part of the public
+licenses.
+
+Creative Commons may be contacted at creativecommons.org.

LICENSES/other/CDDL-1.0

@@ -0,0 +1,364 @@
+Valid-License-Identifier: CDDL-1.0
+SPDX-URL: https://spdx.org/licenses/CDDL-1.0.html
+Usage-Guide:
+  To use the Common Development and Distribution License 1.0 put the
+  following SPDX tag/value pair into a comment according to the placement
+  guidelines in the licensing rules documentation:
+    SPDX-License-Identifier: CDDL-1.0
+
+License-Text:
+
+COMMON DEVELOPMENT AND DISTRIBUTION LICENSE (CDDL)
+Version 1.0
+
+    1. Definitions.
+
+        1.1. "Contributor" means each individual or entity that creates or
+             contributes to the creation of Modifications.
+
+        1.2. "Contributor Version" means the combination of the Original
+	     Software, prior Modifications used by a Contributor (if any),
+	     and the Modifications made by that particular Contributor.
+
+        1.3. "Covered Software" means (a) the Original Software, or (b)
+             Modifications, or (c) the combination of files containing
+             Original Software with files containing Modifications, in each
+             case including portions thereof.
+
+	1.4. "Executable" means the Covered Software in any form other than
+             Source Code.
+
+        1.5. "Initial Developer" means the individual or entity that first
+             makes Original Software available under this License.
+
+        1.6. "Larger Work" means a work which combines Covered Software or
+             portions thereof with code not governed by the terms of this
+             License.
+
+        1.7. "License" means this document.
+
+        1.8. "Licensable" means having the right to grant, to the maximum
+             extent possible, whether at the time of the initial grant or
+             subsequently acquired, any and all of the rights conveyed herein.
+
+        1.9. "Modifications" means the Source Code and Executable form of
+             any of the following:
+
+            A. Any file that results from an addition to, deletion from or
+               modification of the contents of a file containing Original
+               Software or previous Modifications;
+
+            B. Any new file that contains any part of the Original Software
+               or previous Modification; or
+
+            C. Any new file that is contributed or otherwise made available
+               under the terms of this License.
+
+        1.10. "Original Software" means the Source Code and Executable form
+              of computer software code that is originally released under
+              this License.
+
+        1.11. "Patent Claims" means any patent claim(s), now owned or
+              hereafter acquired, including without limitation, method,
+              process, and apparatus claims, in any patent Licensable by
+              grantor.
+
+        1.12. "Source Code" means (a) the common form of computer software
+	      code in which modifications are made and (b) associated
+              documentation included in or with such code.
+
+        1.13. "You" (or "Your") means an individual or a legal entity
+              exercising rights under, and complying with all of the terms
+              of, this License. For legal entities, "You" includes any
+              entity which controls, is controlled by, or is under common
+              control with You. For purposes of this definition, "control"
+              means (a) the power, direct or indirect, to cause the
+              direction or management of such entity, whether by contract
+              or otherwise, or (b) ownership of more than fifty percent
+              (50%) of the outstanding shares or beneficial ownership of
+              such entity.
+
+    2. License Grants.
+        2.1. The Initial Developer Grant.
+
+        Conditioned upon Your compliance with Section 3.1 below and subject
+        to third party intellectual property claims, the Initial Developer
+        hereby grants You a world-wide, royalty-free, non-exclusive
+        license:
+
+            (a) under intellectual property rights (other than patent or
+                trademark) Licensable by Initial Developer, to use,
+                reproduce, modify, display, perform, sublicense and
+                distribute the Original Software (or portions thereof),
+                with or without Modifications, and/or as part of a Larger
+                Work; and
+
+            (b) under Patent Claims infringed by the making, using or
+                selling of Original Software, to make, have made, use,
+                practice, sell, and offer for sale, and/or otherwise
+                dispose of the Original Software (or portions thereof).
+
+            (c) The licenses granted in Sections 2.1(a) and (b) are
+                effective on the date Initial Developer first distributes
+                or otherwise makes the Original Software available to a
+                third party under the terms of this License.
+
+            (d) Notwithstanding Section 2.1(b) above, no patent license is
+                granted: (1) for code that You delete from the Original
+                Software, or (2) for infringements caused by: (i) the
+                modification of the Original Software, or (ii) the
+                combination of the Original Software with other software or
+                devices.
+
+        2.2. Contributor Grant.
+
+        Conditioned upon Your compliance with Section 3.1 below and subject
+        to third party intellectual property claims, each Contributor
+        hereby grants You a world-wide, royalty-free, non-exclusive
+        license:
+
+            (a) under intellectual property rights (other than patent or
+	        trademark) Licensable by Contributor to use, reproduce,
+	        modify, display, perform, sublicense and distribute the
+	        Modifications created by such Contributor (or portions
+	        thereof), either on an unmodified basis, with other
+	        Modifications, as Covered Software and/or as part of a
+	        Larger Work; and
+
+            (b) under Patent Claims infringed by the making, using, or
+                selling of Modifications made by that Contributor either
+                alone and/or in combination with its Contributor Version
+                (or portions of such combination), to make, use, sell,
+                offer for sale, have made, and/or otherwise dispose of: (1)
+                Modifications made by that Contributor (or portions
+                thereof); and (2) the combination of Modifications made by
+                that Contributor with its Contributor Version (or portions
+                of such combination).
+
+            (c) The licenses granted in Sections 2.2(a) and 2.2(b) are
+                effective on the date Contributor first distributes or
+                otherwise makes the Modifications available to a third
+                party.
+
+            (d) Notwithstanding Section 2.2(b) above, no patent license is
+                granted: (1) for any code that Contributor has deleted from
+                the Contributor Version; (2) for infringements caused by:
+                (i) third party modifications of Contributor Version, or
+                (ii) the combination of Modifications made by that
+                Contributor with other software (except as part of the
+                Contributor Version) or other devices; or (3) under Patent
+                Claims infringed by Covered Software in the absence of
+                Modifications made by that Contributor.
+
+    3. Distribution Obligations.
+        3.1. Availability of Source Code.
+
+        Any Covered Software that You distribute or otherwise make
+        available in Executable form must also be made available in Source
+        Code form and that Source Code form must be distributed only under
+        the terms of this License. You must include a copy of this License
+        with every copy of the Source Code form of the Covered Software You
+        distribute or otherwise make available. You must inform recipients
+        of any such Covered Software in Executable form as to how they can
+        obtain such Covered Software in Source Code form in a reasonable
+        manner on or through a medium customarily used for software
+        exchange.
+
+        3.2. Modifications.
+
+        The Modifications that You create or to which You contribute are
+        governed by the terms of this License. You represent that You
+        believe Your Modifications are Your original creation(s) and/or You
+        have sufficient rights to grant the rights conveyed by this
+        License.
+
+        3.3. Required Notices.
+
+        You must include a notice in each of Your Modifications that
+        identifies You as the Contributor of the Modification. You may not
+        remove or alter any copyright, patent or trademark notices
+        contained within the Covered Software, or any notices of licensing
+        or any descriptive text giving attribution to any Contributor or
+        the Initial Developer.
+
+        3.4. Application of Additional Terms.
+
+        You may not offer or impose any terms on any Covered Software in
+        Source Code form that alters or restricts the applicable version of
+        this License or the recipients' rights hereunder. You may choose to
+        offer, and to charge a fee for, warranty, support, indemnity or
+        liability obligations to one or more recipients of Covered
+        Software. However, you may do so only on Your own behalf, and not
+        on behalf of the Initial Developer or any Contributor. You must
+        make it absolutely clear that any such warranty, support, indemnity
+        or liability obligation is offered by You alone, and You hereby
+        agree to indemnify the Initial Developer and every Contributor for
+        any liability incurred by the Initial Developer or such Contributor
+        as a result of warranty, support, indemnity or liability terms You
+        offer.
+
+        3.5. Distribution of Executable Versions.
+
+        You may distribute the Executable form of the Covered Software
+        under the terms of this License or under the terms of a license of
+        Your choice, which may contain terms different from this License,
+        provided that You are in compliance with the terms of this License
+        and that the license for the Executable form does not attempt to
+        limit or alter the recipient's rights in the Source Code form from
+        the rights set forth in this License. If You distribute the Covered
+        Software in Executable form under a different license, You must
+        make it absolutely clear that any terms which differ from this
+        License are offered by You alone, not by the Initial Developer or
+        Contributor. You hereby agree to indemnify the Initial Developer
+        and every Contributor for any liability incurred by the Initial
+        Developer or such Contributor as a result of any such terms You
+        offer.
+
+        3.6. Larger Works.
+
+        You may create a Larger Work by combining Covered Software with
+        other code not governed by the terms of this License and distribute
+        the Larger Work as a single product. In such a case, You must make
+        sure the requirements of this License are fulfilled for the Covered
+        Software.
+
+    4. Versions of the License.
+        4.1. New Versions.
+
+        Sun Microsystems, Inc. is the initial license steward and may
+        publish revised and/or new versions of this License from time to
+        time. Each version will be given a distinguishing version
+        number. Except as provided in Section 4.3, no one other than the
+        license steward has the right to modify this License.
+
+        4.2. Effect of New Versions.
+
+        You may always continue to use, distribute or otherwise make the
+        Covered Software available under the terms of the version of the
+        License under which You originally received the Covered
+        Software. If the Initial Developer includes a notice in the
+        Original Software prohibiting it from being distributed or
+        otherwise made available under any subsequent version of the
+        License, You must distribute and make the Covered Software
+        available under the terms of the version of the License under which
+        You originally received the Covered Software. Otherwise, You may
+        also choose to use, distribute or otherwise make the Covered
+        Software available under the terms of any subsequent version of the
+        License published by the license steward.
+
+        4.3. Modified Versions.
+
+        When You are an Initial Developer and You want to create a new
+        license for Your Original Software, You may create and use a
+        modified version of this License if You: (a) rename the license and
+        remove any references to the name of the license steward (except to
+        note that the license differs from this License); and (b) otherwise
+        make it clear that the license contains terms which differ from
+        this License.
+
+    5. DISCLAIMER OF WARRANTY.
+
+    COVERED SOFTWARE IS PROVIDED UNDER THIS LICENSE ON AN "AS IS" BASIS,
+    WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING,
+    WITHOUT LIMITATION, WARRANTIES THAT THE COVERED SOFTWARE IS FREE OF
+    DEFECTS, MERCHANTABLE, FIT FOR A PARTICULAR PURPOSE OR
+    NON-INFRINGING. THE ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE OF
+    THE COVERED SOFTWARE IS WITH YOU. SHOULD ANY COVERED SOFTWARE PROVE
+    DEFECTIVE IN ANY RESPECT, YOU (NOT THE INITIAL DEVELOPER OR ANY OTHER
+    CONTRIBUTOR) ASSUME THE COST OF ANY NECESSARY SERVICING, REPAIR OR
+    CORRECTION. THIS DISCLAIMER OF WARRANTY CONSTITUTES AN ESSENTIAL PART
+    OF THIS LICENSE. NO USE OF ANY COVERED SOFTWARE IS AUTHORIZED HEREUNDER
+    EXCEPT UNDER THIS DISCLAIMER.
+
+    6. TERMINATION.
+
+        6.1. This License and the rights granted hereunder will terminate
+        automatically if You fail to comply with terms herein and fail to
+        cure such breach within 30 days of becoming aware of the
+        breach. Provisions which, by their nature, must remain in effect
+        beyond the termination of this License shall survive.
+
+        6.2. If You assert a patent infringement claim (excluding
+        declaratory judgment actions) against Initial Developer or a
+        Contributor (the Initial Developer or Contributor against whom You
+        assert such claim is referred to as "Participant") alleging that
+        the Participant Software (meaning the Contributor Version where the
+        Participant is a Contributor or the Original Software where the
+        Participant is the Initial Developer) directly or indirectly
+        infringes any patent, then any and all rights granted directly or
+        indirectly to You by such Participant, the Initial Developer (if
+        the Initial Developer is not the Participant) and all Contributors
+        under Sections 2.1 and/or 2.2 of this License shall, upon 60 days
+        notice from Participant terminate prospectively and automatically
+        at the expiration of such 60 day notice period, unless if within
+        such 60 day period You withdraw Your claim with respect to the
+        Participant Software against such Participant either unilaterally
+        or pursuant to a written agreement with Participant.
+
+        6.3. In the event of termination under Sections 6.1 or 6.2 above,
+        all end user licenses that have been validly granted by You or any
+        distributor hereunder prior to termination (excluding licenses
+        granted to You by any distributor) shall survive termination.
+
+    7. LIMITATION OF LIABILITY.
+
+    UNDER NO CIRCUMSTANCES AND UNDER NO LEGAL THEORY, WHETHER TORT
+    (INCLUDING NEGLIGENCE), CONTRACT, OR OTHERWISE, SHALL YOU, THE INITIAL
+    DEVELOPER, ANY OTHER CONTRIBUTOR, OR ANY DISTRIBUTOR OF COVERED
+    SOFTWARE, OR ANY SUPPLIER OF ANY OF SUCH PARTIES, BE LIABLE TO ANY
+    PERSON FOR ANY INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
+    OF ANY CHARACTER INCLUDING, WITHOUT LIMITATION, DAMAGES FOR LOST
+    PROFITS, LOSS OF GOODWILL, WORK STOPPAGE, COMPUTER FAILURE OR
+    MALFUNCTION, OR ANY AND ALL OTHER COMMERCIAL DAMAGES OR LOSSES, EVEN IF
+    SUCH PARTY SHALL HAVE BEEN INFORMED OF THE POSSIBILITY OF SUCH
+    DAMAGES. THIS LIMITATION OF LIABILITY SHALL NOT APPLY TO LIABILITY FOR
+    DEATH OR PERSONAL INJURY RESULTING FROM SUCH PARTY'S NEGLIGENCE TO THE
+    EXTENT APPLICABLE LAW PROHIBITS SUCH LIMITATION. SOME JURISDICTIONS DO
+    NOT ALLOW THE EXCLUSION OR LIMITATION OF INCIDENTAL OR CONSEQUENTIAL
+    DAMAGES, SO THIS EXCLUSION AND LIMITATION MAY NOT APPLY TO YOU.
+
+    8. U.S. GOVERNMENT END USERS.
+
+    The Covered Software is a "commercial item," as that term is defined in
+    48 C.F.R. 2.101 (Oct. 1995), consisting of "commercial computer
+    software" (as that term is defined at 48 C.F.R. $ 252.227-7014(a)(1))
+    and "commercial computer software documentation" as such terms are used
+    in 48 C.F.R. 12.212 (Sept. 1995). Consistent with 48 C.F.R. 12.212 and
+    48 C.F.R. 227.7202-1 through 227.7202-4 (June 1995), all
+    U.S. Government End Users acquire Covered Software with only those
+    rights set forth herein. This U.S. Government Rights clause is in lieu
+    of, and supersedes, any other FAR, DFAR, or other clause or provision
+    that addresses Government rights in computer software under this
+    License.
+
+    9. MISCELLANEOUS.
+
+    This License represents the complete agreement concerning subject
+    matter hereof. If any provision of this License is held to be
+    unenforceable, such provision shall be reformed only to the extent
+    necessary to make it enforceable. This License shall be governed by the
+    law of the jurisdiction specified in a notice contained within the
+    Original Software (except to the extent applicable law, if any,
+    provides otherwise), excluding such jurisdiction's conflict-of-law
+    provisions. Any litigation relating to this License shall be subject to
+    the jurisdiction of the courts located in the jurisdiction and venue
+    specified in a notice contained within the Original Software, with the
+    losing party responsible for costs, including, without limitation,
+    court costs and reasonable attorneys' fees and expenses. The
+    application of the United Nations Convention on Contracts for the
+    International Sale of Goods is expressly excluded. Any law or
+    regulation which provides that the language of a contract shall be
+    construed against the drafter shall not apply to this License. You
+    agree that You alone are responsible for compliance with the United
+    States export administration regulations (and the export control laws
+    and regulation of any other countries) when You use, distribute or
+    otherwise make available any Covered Software.
+
+    10. RESPONSIBILITY FOR CLAIMS.
+
+    As between Initial Developer and the Contributors, each party is
+    responsible for claims and damages arising, directly or indirectly, out
+    of its utilization of rights under this License and You agree to work
+    with Initial Developer and Contributors to distribute such
+    responsibility on an equitable basis. Nothing herein is intended or
+    shall be deemed to constitute any admission of liability.

LICENSES/other/Linux-OpenIB

@@ -0,0 +1,26 @@
+Valid-License-Identifier: Linux-OpenIB
+SPDX-URL: https://spdx.org/licenses/Linux-OpenIB.html
+Usage-Guide:
+  To use the Linux Kernel Variant of OpenIB.org license put the following
+  SPDX tag/value pair into a comment according to the placement guidelines
+  in the licensing rules documentation:
+    SPDX-License-Identifier: Linux-OpenIB
+License-Text:
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are met:
+
+    - Redistributions of source code must retain the above copyright
+      notice, this list of conditions and the following disclaimer.
+
+    - Redistributions in binary form must reproduce the above copyright
+      notice, this list of conditions and the following disclaimer in the
+      documentation and/or other materials provided with the distribution.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+DEALINGS IN THE SOFTWARE.

LICENSES/other/X11

@@ -0,0 +1,37 @@
+Valid-License-Identifier: X11
+SPDX-URL: https://spdx.org/licenses/X11.html
+Usage-Guide:
+  To use the X11 put the following SPDX tag/value pair into a comment
+  according to the placement guidelines in the licensing rules
+  documentation:
+    SPDX-License-Identifier: X11
+License-Text:
+
+
+X11 License
+
+Copyright (C) 1996 X Consortium
+
+Permission is hereby granted, free of charge, to any person obtaining a
+copy of this software and associated documentation files (the "Software"),
+to deal in the Software without restriction, including without limitation
+the rights to use, copy, modify, merge, publish, distribute, sublicense,
+and/or sell copies of the Software, and to permit persons to whom the
+Software is furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in
+all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+X CONSORTIUM BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
+IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+Except as contained in this notice, the name of the X Consortium shall not
+be used in advertising or otherwise to promote the sale, use or other
+dealings in this Software without prior written authorization from the X
+Consortium.
+
+X Window System is a trademark of X Consortium, Inc.

LICENSES/preferred/GPL-2.0

@@ -1,5 +1,7 @@
 Valid-License-Identifier: GPL-2.0
+Valid-License-Identifier: GPL-2.0-only
 Valid-License-Identifier: GPL-2.0+
+Valid-License-Identifier: GPL-2.0-or-later
 SPDX-URL: https://spdx.org/licenses/GPL-2.0.html
 Usage-Guide:
   To use this license in source code, put one of the following SPDX
@@ -7,8 +9,12 @@ Usage-Guide:
   guidelines in the licensing rules documentation.
   For 'GNU General Public License (GPL) version 2 only' use:
     SPDX-License-Identifier: GPL-2.0
+  or
+    SPDX-License-Identifier: GPL-2.0-only
   For 'GNU General Public License (GPL) version 2 or any later version' use:
     SPDX-License-Identifier: GPL-2.0+
+  or
+    SPDX-License-Identifier: GPL-2.0-or-later
 License-Text:
 
 		    GNU GENERAL PUBLIC LICENSE

scripts/spdxcheck.py

@@ -0,0 +1,284 @@
+#!/usr/bin/env python
+# SPDX-License-Identifier: GPL-2.0
+# Copyright Thomas Gleixner <tglx@linutronix.de>
+
+from argparse import ArgumentParser
+from ply import lex, yacc
+import traceback
+import sys
+import git
+import re
+import os
+
+class ParserException(Exception):
+    def __init__(self, tok, txt):
+        self.tok = tok
+        self.txt = txt
+
+class SPDXException(Exception):
+    def __init__(self, el, txt):
+        self.el = el
+        self.txt = txt
+
+class SPDXdata(object):
+    def __init__(self):
+        self.license_files = 0
+        self.exception_files = 0
+        self.licenses = [ ]
+        self.exceptions = { }
+
+# Read the spdx data from the LICENSES directory
+def read_spdxdata(repo):
+
+    # The subdirectories of LICENSES in the kernel source
+    license_dirs = [ "preferred", "other", "exceptions" ]
+    lictree = repo.heads.master.commit.tree['LICENSES']
+
+    spdx = SPDXdata()
+
+    for d in license_dirs:
+        for el in lictree[d].traverse():
+            if not os.path.isfile(el.path):
+                continue
+
+            exception = None
+            for l in open(el.path).readlines():
+                if l.startswith('Valid-License-Identifier:'):
+                    lid = l.split(':')[1].strip().upper()
+                    if lid in spdx.licenses:
+                        raise SPDXException(el, 'Duplicate License Identifier: %s' %lid)
+                    else:
+                        spdx.licenses.append(lid)
+
+                elif l.startswith('SPDX-Exception-Identifier:'):
+                    exception = l.split(':')[1].strip().upper()
+                    spdx.exceptions[exception] = []
+
+                elif l.startswith('SPDX-Licenses:'):
+                    for lic in l.split(':')[1].upper().strip().replace(' ', '').replace('\t', '').split(','):
+                        if not lic in spdx.licenses:
+                            raise SPDXException(None, 'Exception %s missing license %s' %(ex, lic))
+                        spdx.exceptions[exception].append(lic)
+
+                elif l.startswith("License-Text:"):
+                    if exception:
+                        if not len(spdx.exceptions[exception]):
+                            raise SPDXException(el, 'Exception %s is missing SPDX-Licenses' %excid)
+                        spdx.exception_files += 1
+                    else:
+                        spdx.license_files += 1
+                    break
+    return spdx
+
+class id_parser(object):
+
+    reserved = [ 'AND', 'OR', 'WITH' ]
+    tokens = [ 'LPAR', 'RPAR', 'ID', 'EXC' ] + reserved
+
+    precedence = ( ('nonassoc', 'AND', 'OR'), )
+
+    t_ignore = ' \t'
+
+    def __init__(self, spdx):
+        self.spdx = spdx
+        self.lasttok = None
+        self.lastid = None
+        self.lexer = lex.lex(module = self, reflags = re.UNICODE)
+        # Initialize the parser. No debug file and no parser rules stored on disk
+        # The rules are small enough to be generated on the fly
+        self.parser = yacc.yacc(module = self, write_tables = False, debug = False)
+        self.lines_checked = 0
+        self.checked = 0
+        self.spdx_valid = 0
+        self.spdx_errors = 0
+        self.curline = 0
+        self.deepest = 0
+
+    # Validate License and Exception IDs
+    def validate(self, tok):
+        id = tok.value.upper()
+        if tok.type == 'ID':
+            if not id in self.spdx.licenses:
+                raise ParserException(tok, 'Invalid License ID')
+            self.lastid = id
+        elif tok.type == 'EXC':
+            if not self.spdx.exceptions.has_key(id):
+                raise ParserException(tok, 'Invalid Exception ID')
+            if self.lastid not in self.spdx.exceptions[id]:
+                raise ParserException(tok, 'Exception not valid for license %s' %self.lastid)
+            self.lastid = None
+        elif tok.type != 'WITH':
+            self.lastid = None
+
+    # Lexer functions
+    def t_RPAR(self, tok):
+        r'\)'
+        self.lasttok = tok.type
+        return tok
+
+    def t_LPAR(self, tok):
+        r'\('
+        self.lasttok = tok.type
+        return tok
+
+    def t_ID(self, tok):
+        r'[A-Za-z.0-9\-+]+'
+
+        if self.lasttok == 'EXC':
+            print(tok)
+            raise ParserException(tok, 'Missing parentheses')
+
+        tok.value = tok.value.strip()
+        val = tok.value.upper()
+
+        if val in self.reserved:
+            tok.type = val
+        elif self.lasttok == 'WITH':
+            tok.type = 'EXC'
+
+        self.lasttok = tok.type
+        self.validate(tok)
+        return tok
+
+    def t_error(self, tok):
+        raise ParserException(tok, 'Invalid token')
+
+    def p_expr(self, p):
+        '''expr : ID
+                | ID WITH EXC
+                | expr AND expr
+                | expr OR expr
+                | LPAR expr RPAR'''
+        pass
+
+    def p_error(self, p):
+        if not p:
+            raise ParserException(None, 'Unfinished license expression')
+        else:
+            raise ParserException(p, 'Syntax error')
+
+    def parse(self, expr):
+        self.lasttok = None
+        self.lastid = None
+        self.parser.parse(expr, lexer = self.lexer)
+
+    def parse_lines(self, fd, maxlines, fname):
+        self.checked += 1
+        self.curline = 0
+        try:
+            for line in fd:
+                self.curline += 1
+                if self.curline > maxlines:
+                    break
+                self.lines_checked += 1
+                if line.find("SPDX-License-Identifier:") < 0:
+                    continue
+                expr = line.split(':')[1].replace('*/', '').strip()
+                self.parse(expr)
+                self.spdx_valid += 1
+                #
+                # Should we check for more SPDX ids in the same file and
+                # complain if there are any?
+                #
+                break
+
+        except ParserException as pe:
+            if pe.tok:
+                col = line.find(expr) + pe.tok.lexpos
+                tok = pe.tok.value
+                sys.stdout.write('%s: %d:%d %s: %s\n' %(fname, self.curline, col, pe.txt, tok))
+            else:
+                sys.stdout.write('%s: %d:0 %s\n' %(fname, self.curline, col, pe.txt))
+            self.spdx_errors += 1
+
+def scan_git_tree(tree):
+    for el in tree.traverse():
+        # Exclude stuff which would make pointless noise
+        # FIXME: Put this somewhere more sensible
+        if el.path.startswith("LICENSES"):
+            continue
+        if el.path.find("license-rules.rst") >= 0:
+            continue
+        if el.path == 'scripts/checkpatch.pl':
+            continue
+        if not os.path.isfile(el.path):
+            continue
+        parser.parse_lines(open(el.path), args.maxlines, el.path)
+
+def scan_git_subtree(tree, path):
+    for p in path.strip('/').split('/'):
+        tree = tree[p]
+    scan_git_tree(tree)
+
+if __name__ == '__main__':
+
+    ap = ArgumentParser(description='SPDX expression checker')
+    ap.add_argument('path', nargs='*', help='Check path or file. If not given full git tree scan. For stdin use "-"')
+    ap.add_argument('-m', '--maxlines', type=int, default=15,
+                    help='Maximum number of lines to scan in a file. Default 15')
+    ap.add_argument('-v', '--verbose', action='store_true', help='Verbose statistics output')
+    args = ap.parse_args()
+
+    # Sanity check path arguments
+    if '-' in args.path and len(args.path) > 1:
+        sys.stderr.write('stdin input "-" must be the only path argument\n')
+        sys.exit(1)
+
+    try:
+        # Use git to get the valid license expressions
+        repo = git.Repo(os.getcwd())
+        assert not repo.bare
+
+        # Initialize SPDX data
+        spdx = read_spdxdata(repo)
+
+        # Initilize the parser
+        parser = id_parser(spdx)
+
+    except SPDXException as se:
+        if se.el:
+            sys.stderr.write('%s: %s\n' %(se.el.path, se.txt))
+        else:
+            sys.stderr.write('%s\n' %se.txt)
+        sys.exit(1)
+
+    except Exception as ex:
+        sys.stderr.write('FAIL: %s\n' %ex)
+        sys.stderr.write('%s\n' %traceback.format_exc())
+        sys.exit(1)
+
+    try:
+        if len(args.path) and args.path[0] == '-':
+            parser.parse_lines(sys.stdin, args.maxlines, '-')
+        else:
+            if args.path:
+                for p in args.path:
+                    if os.path.isfile(p):
+                        parser.parse_lines(open(p), args.maxlines, p)
+                    elif os.path.isdir(p):
+                        scan_git_subtree(repo.head.reference.commit.tree, p)
+                    else:
+                        sys.stderr.write('path %s does not exist\n' %p)
+                        sys.exit(1)
+            else:
+                # Full git tree scan
+                scan_git_tree(repo.head.commit.tree)
+
+            if args.verbose:
+                sys.stderr.write('\n')
+                sys.stderr.write('License files:     %12d\n' %spdx.license_files)
+                sys.stderr.write('Exception files:   %12d\n' %spdx.exception_files)
+                sys.stderr.write('License IDs        %12d\n' %len(spdx.licenses))
+                sys.stderr.write('Exception IDs      %12d\n' %len(spdx.exceptions))
+                sys.stderr.write('\n')
+                sys.stderr.write('Files checked:     %12d\n' %parser.checked)
+                sys.stderr.write('Lines checked:     %12d\n' %parser.lines_checked)
+                sys.stderr.write('Files with SPDX:   %12d\n' %parser.spdx_valid)
+                sys.stderr.write('Files with errors: %12d\n' %parser.spdx_errors)
+
+            sys.exit(0)
+
+    except Exception as ex:
+        sys.stderr.write('FAIL: %s\n' %ex)
+        sys.stderr.write('%s\n' %traceback.format_exc())
+        sys.exit(1)