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From:   Masahiro Yamada <yamada.masahiro@socionext.com>
Date:   Sat, 13 Apr 2019 11:58:53 +0900
Message-ID: <CAK7LNATW0EQ+uYqGgEbzp1pzajs2CBOWT937JOCNnepP3AAD1g@mail.gmail.com>
Subject: Re: [PATCH v6 1/2] Provide in-kernel headers to make extending kernel easier
To:     Daniel Colascione <dancol@google.com>
Cc:     Joel Fernandes <joel@joelfernandes.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        Andrew Morton <akpm@linux-foundation.org>,
        Alexei Starovoitov <ast@kernel.org>,
        atish patra <atishp04@gmail.com>,
        Dan Williams <dan.j.williams@intel.com>,
        Dietmar Eggemann <dietmar.eggemann@arm.com>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Guenter Roeck <groeck@chromium.org>,
        Jonathan Corbet <corbet@lwn.net>,
        Karim Yaghmour <karim.yaghmour@opersys.com>,
        Kees Cook <keescook@chromium.org>,
        "Cc: Android Kernel" <kernel-team@android.com>,
        "open list:DOCUMENTATION" <linux-doc@vger.kernel.org>,
        "open list:KERNEL SELFTEST FRAMEWORK" 
        <linux-kselftest@vger.kernel.org>,
        linux-trace-devel@vger.kernel.org,
        Manoj Rao <linux@manojrajarao.com>,
        Masami Hiramatsu <mhiramat@kernel.org>,
        Qais Yousef <qais.yousef@arm.com>,
        Randy Dunlap <rdunlap@infradead.org>,
        Steven Rostedt <rostedt@goodmis.org>,
        Shuah Khan <shuah@kernel.org>, Yonghong Song <yhs@fb.com>
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On Sat, Apr 13, 2019 at 10:53 AM Daniel Colascione <dancol@google.com> wrote:
>
> On Fri, Apr 12, 2019 at 6:49 PM Masahiro Yamada
> <yamada.masahiro@socionext.com> wrote:
> >
> > On Sat, Apr 13, 2019 at 3:02 AM Joel Fernandes <joel@joelfernandes.org> wrote:
> >
> > >
> > > > > +extern char kernel_headers_data;
> > > > > +extern char kernel_headers_data_end;
> > > > > +
> > > > > +static ssize_t
> > > > > +ikheaders_read_current(struct file *file, char __user *buf,
> > > >
> > > > Could you stretch this line ?
> > > > It will still fit in 80-cols.
> > > >
> > > > (This is a coding style error in kernel/configs.c)
> > >
> > > It takes 87 cols if I expand, so I'll leave it as is.
> > >
> >
> >
> > Sorry if what I said was unclear.
> >
> > Since I just did not a good reason to put
> > "static ssize_t" in the previous line,
> > I meant like follows:
> >
> >
> > [Before]
> > static ssize_t
> > ikheaders_read_current(struct file *file, char __user *buf,
> >                        size_t len, loff_t *offset)
> >
> >
> >
> > [After]
> > static ssize_t ikheaders_read_current(struct file *file, char __user *buf,
> >                                       size_t len, loff_t *offset)
> >
> >
> > (takes 74-cols.)
> >
> >
> > (I am sending this from Gmail, so I am not sure
> > how it will look like from you...)
> >
> >
> > Anyway, it is super-bikeshedding stuff.
> > It is OK as-is.
> >
>
> What about sorting the files for determinism?


Do you mean the order of files in the tar archive?
I think it is a good idea for reproducible build.


It looks like the tar command supports --sort=name option,
but I did not test it at all.


Perhaps, the sorting policy could be affected by locale.
We saw it for the 'find' command.
I am not sure about the tar command though.


commit f55f2328bb28a8517620518c5d124f5194673309
Author: Andrzej Pietrasiewicz <andrzej.p@samsung.com>
Date:   Fri Aug 17 14:03:19 2018 +0200

    kbuild: make sorting initramfs contents independent of locale


--
Best Regards
Masahiro Yamada