2019-02-12 06:29:27

by Ben Finney

[permalink] [raw]
Subject: Re: Bug#919356: Licensing of include/linux/hash.h

Martin Steigerwald <[email protected]> writes:

> Well the file has in its header:
>
> /* Fast hashing routine for a long.
> (C) 2002 William Lee Irwin III, IBM */
>
> /*
> * Knuth recommends primes in approximately golden ratio to the maximum
> * integer representable by a machine word for multiplicative hashing.
> * Chuck Lever verified the effectiveness of this technique:
> * http://www.citi.umich.edu/techreports/reports/citi-tr-00-1.pdf
> *
> * These primes are chosen to be bit-sparse, that is operations on
> * them can use shifts and additions instead of multiplications for
> * machines where multiplications are slow.
> */
>
> It has been quite a while ago. I bet back then I did not regard this
> as license information since it does not specify a license. Thus I
> assumed it to be GPL-2 as the other files which have no license boiler
> plate. I.e.: Check file is it has different license, if not, then
> assume it has license as specified in COPYING.
>
> Not specifying a license can however also mean in this context that it
> has no license as the file contains copyright information from another
> author.

If a work (even one file) “has no license”, that means no special
permissions are granted and normal copyright applies: All rights
reserved, i.e. not redistributable. So, no license is grounds to
consider a work non-free and non-redistributable.

If, on the other hand, the file is to be free software, there would need
to be a clear grant of some free software license to that work.

Given the confusion over this file, I would consider it a significant
risk to just assume we have GPLv2 permissions without being told that
explicitly by the copyright holder. Rather, the reason we are seeking a
clearly-granted free license for this one file, is because we are trying
to replace a probably non-free file with the same code in it.

It seems we need to keep looking, and in the meantime assume we have no
free license in this file.

--
\ “If the desire to kill and the opportunity to kill came always |
`\ together, who would escape hanging?” —Mark Twain, _Following |
_o__) the Equator_ |
Ben Finney <[email protected]>


2019-02-12 16:17:27

by Jens Axboe

[permalink] [raw]
Subject: Re: Bug#919356: Licensing of include/linux/hash.h

On 2/11/19 11:27 PM, Ben Finney wrote:
> Martin Steigerwald <[email protected]> writes:
>
>> Well the file has in its header:
>>
>> /* Fast hashing routine for a long.
>> (C) 2002 William Lee Irwin III, IBM */
>>
>> /*
>> * Knuth recommends primes in approximately golden ratio to the maximum
>> * integer representable by a machine word for multiplicative hashing.
>> * Chuck Lever verified the effectiveness of this technique:
>> * http://www.citi.umich.edu/techreports/reports/citi-tr-00-1.pdf
>> *
>> * These primes are chosen to be bit-sparse, that is operations on
>> * them can use shifts and additions instead of multiplications for
>> * machines where multiplications are slow.
>> */
>>
>> It has been quite a while ago. I bet back then I did not regard this
>> as license information since it does not specify a license. Thus I
>> assumed it to be GPL-2 as the other files which have no license boiler
>> plate. I.e.: Check file is it has different license, if not, then
>> assume it has license as specified in COPYING.
>>
>> Not specifying a license can however also mean in this context that it
>> has no license as the file contains copyright information from another
>> author.
>
> If a work (even one file) “has no license”, that means no special
> permissions are granted and normal copyright applies: All rights
> reserved, i.e. not redistributable. So, no license is grounds to
> consider a work non-free and non-redistributable.
>
> If, on the other hand, the file is to be free software, there would need
> to be a clear grant of some free software license to that work.
>
> Given the confusion over this file, I would consider it a significant
> risk to just assume we have GPLv2 permissions without being told that
> explicitly by the copyright holder. Rather, the reason we are seeking a
> clearly-granted free license for this one file, is because we are trying
> to replace a probably non-free file with the same code in it.
>
> It seems we need to keep looking, and in the meantime assume we have no
> free license in this file.

FWIW, fio.c includes the following mention:

* The license below covers all files distributed with fio unless otherwise
* noted in the file itself.

followed by the GPL v2 license. I'll go through and add SPDX headers to
everything to avoid wasting anymore time on this nonsense.

--
Jens Axboe


2019-02-12 21:43:41

by Martin Steigerwald

[permalink] [raw]
Subject: Re: Bug#919356: Licensing of include/linux/hash.h

On 2/11/19 11:27 PM, Ben Finney wrote:
> Martin Steigerwald <[email protected]> writes:
>
>> Well the file has in its header:
>>
>> /* Fast hashing routine for a long.
>> (C) 2002 William Lee Irwin III, IBM */
>>
>> /*
>> * Knuth recommends primes in approximately golden ratio to the
maximum
>> * integer representable by a machine word for multiplicative
hashing.
>> * Chuck Lever verified the effectiveness of this technique:
>> * http://www.citi.umich.edu/techreports/reports/citi-tr-00-1.pdf
>> *
>> * These primes are chosen to be bit-sparse, that is operations on
>> * them can use shifts and additions instead of multiplications for
>> * machines where multiplications are slow.
>> */
>>
>> It has been quite a while ago. I bet back then I did not regard this
>> as license information since it does not specify a license. Thus I
>> assumed it to be GPL-2 as the other files which have no license boiler
>> plate. I.e.: Check file is it has different license, if not, then
>> assume it has license as specified in COPYING.
>>
>> Not specifying a license can however also mean in this context that
it
>> has no license as the file contains copyright information from another
>> author.
>
> If a work (even one file) “has no license”, that means no special
> permissions are granted and normal copyright applies: All rights
> reserved, i.e. not redistributable. So, no license is grounds to
> consider a work non-free and non-redistributable.
>
> If, on the other hand, the file is to be free software, there would
need
> to be a clear grant of some free software license to that work.
>
> Given the confusion over this file, I would consider it a significant
> risk to just assume we have GPLv2 permissions without being told that
> explicitly by the copyright holder. Rather, the reason we are seeking
a
> clearly-granted free license for this one file, is because we are
trying
> to replace a probably non-free file with the same code in it.
>
> It seems we need to keep looking, and in the meantime assume we have
no
> free license in this file.

FWIW, fio.c includes the following mention:

* The license below covers all files distributed with fio unless
otherwise
* noted in the file itself.

followed by the GPL v2 license. I'll go through and add SPDX headers to
everything to avoid wasting anymore time on this nonsense.

--
Jens Axboe





2019-02-12 21:43:41

by Martin Steigerwald

[permalink] [raw]
Subject: Re: Bug#919356: Licensing of include/linux/hash.h

Jens Axboe - 12.02.19, 17:16:
> On 2/11/19 11:27 PM, Ben Finney wrote:
> > Martin Steigerwald <[email protected]> writes:
> >> Well the file has in its header:
> >>
> >> /* Fast hashing routine for a long.
> >>
> >> (C) 2002 William Lee Irwin III, IBM */
> >>
> >> /*
> >>
> >> * Knuth recommends primes in approximately golden ratio to the
> >> maximum * integer representable by a machine word for
> >> multiplicative hashing. * Chuck Lever verified the effectiveness
> >> of this technique:
> >> * http://www.citi.umich.edu/techreports/reports/citi-tr-00-1.pdf
> >> *
> >> * These primes are chosen to be bit-sparse, that is operations on
> >> * them can use shifts and additions instead of multiplications for
> >> * machines where multiplications are slow.
> >> */
> >>
> >> It has been quite a while ago. I bet back then I did not regard
> >> this
> >> as license information since it does not specify a license. Thus I
> >> assumed it to be GPL-2 as the other files which have no license
> >> boiler plate. I.e.: Check file is it has different license, if
> >> not, then assume it has license as specified in COPYING.
> >>
> >> Not specifying a license can however also mean in this context that
> >> it has no license as the file contains copyright information from
> >> another author.
> >
> > If a work (even one file) “has no license”, that means no special
> > permissions are granted and normal copyright applies: All rights
> > reserved, i.e. not redistributable. So, no license is grounds to
> > consider a work non-free and non-redistributable.
> >
> > If, on the other hand, the file is to be free software, there would
> > need to be a clear grant of some free software license to that
> > work.
> >
> > Given the confusion over this file, I would consider it a
> > significant
> > risk to just assume we have GPLv2 permissions without being told
> > that
> > explicitly by the copyright holder. Rather, the reason we are
> > seeking a clearly-granted free license for this one file, is
> > because we are trying to replace a probably non-free file with the
> > same code in it.
> >
> > It seems we need to keep looking, and in the meantime assume we have
> > no free license in this file.
>
> FWIW, fio.c includes the following mention:
>
> * The license below covers all files distributed with fio unless
> otherwise * noted in the file itself.
>
> followed by the GPL v2 license. I'll go through and add SPDX headers
> to everything to avoid wasting anymore time on this nonsense.

Thank you, Jens, for settling this. I did not remember that one. It may
very well be that I have seen this note as I initially packaged fio as my
first package for Debian about 10 years ago.

I forwarded your mail and the one from Domenico with the SPDX patch to
Debian bug

#922112 fio: hash.h is not DFSG compliant
https://bugs.debian.org/922112

which I closed before as you told already that hash.c is GPL-2.

Thanks,
--
Martin



2019-02-12 22:30:25

by Ben Finney

[permalink] [raw]
Subject: Re: Bug#919356: Licensing of include/linux/hash.h

Jens Axboe <[email protected]> writes:

> On 2/11/19 11:27 PM, Ben Finney wrote:
> > If, on the other hand, the file is to be free software, there would need
> > to be a clear grant of some free software license to that work.
>
> FWIW, fio.c includes the following mention:
>
> * The license below covers all files distributed with fio unless otherwise
> * noted in the file itself.
>
> followed by the GPL v2 license.

Great! That does appear to be a positive assertion from the copyright
holder, that we have a grant to use that work under GPLv2.

That written grant of license can be used in the Debian package to
demonstrate our license to the work.

> I'll go through and add SPDX headers to everything to avoid wasting
> anymore time on this nonsense.

Not necessary from my point of view for this specific case, because we
have the clear explicit grant of license. Don't let me stop you from
doing the good work of documenting more clearly :-)

--
\ “Come on Milhouse, there’s no such thing as a soul! It’s just |
`\ something they made up to scare kids, like the Boogie Man or |
_o__) Michael Jackson.” —Bart, _The Simpsons_ |
Ben Finney