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From:   Masahiro Yamada <yamada.masahiro@socionext.com>
Date:   Tue, 8 Oct 2019 19:27:35 +0900
Message-ID: <CAK7LNARhd7Ogmk8wMnDS9K=jvbBNUAZjkK66U++gGHhWLvgvww@mail.gmail.com>
Subject: Re: [PATCH v2] kheaders: making headers archive reproducible
To:     Dmitry Goldin <dgoldin@protonmail.ch>
Cc:     Andreas Schwab <schwab@linux-m68k.org>,
        Greg KH <gregkh@linuxfoundation.org>,
        "linux-kernel\\\\@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        "joel\\\\@joelfernandes.org" <joel@joelfernandes.org>,
        Ben Hutchings <ben@decadent.org.uk>
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On Tue, Oct 8, 2019 at 6:54 PM Dmitry Goldin <dgoldin@protonmail.ch> wrote:
>
> =E2=80=90=E2=80=90=E2=80=90=E2=80=90=E2=80=90=E2=80=90=E2=80=90 Original =
Message =E2=80=90=E2=80=90=E2=80=90=E2=80=90=E2=80=90=E2=80=90=E2=80=90
> On Tuesday, October 8, 2019 10:14 AM, Masahiro Yamada <yamada.masahiro@so=
cionext.com> wrote:
>
> > On Tue, Oct 8, 2019 at 5:07 PM Dmitry Goldin dgoldin@protonmail.ch wrot=
e:
> >
> > > Hmm. --sort was introduced in 1.28 in 2014. Do you think it would war=
rant some sort of version check and fallback or is this something we can ex=
pect the user to handle if their distribution happens to not ship anything =
more recent? A few sensible workarounds come to mind.
> >
> > I think the former.
>
> After pondering it briefly, maybe substituting the option is a bit less h=
assle than checking for
> the version and then degrading to a possibly non-reproducible archive.
>
> Maybe we could go with something like the sketch below to replace --sort=
=3Dname. That is, if
> that's the only problematic flag.
>
> find $cpio_dir -printf "%P\n" | LC_ALL=3DC sort | \
>     tar "${KBUILD_BUILD_TIMESTAMP:+--mtime=3D$KBUILD_BUILD_TIMESTAMP}" \
>     --owner=3D0 --group=3D0 --numeric-owner \
>     -Jcf $tarfile -C $cpio_dir/ -T - > /dev/null
>
> I will look at this a bit more closely and give it a test-run later today=
 or early tomorrow. Then we can decide if its sufficient before submitting =
another patch. Other suggestions and pointers are welcome, of course.


I am fine with this solution too.

Thanks!

--=20
Best Regards
Masahiro Yamada