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Date:   Thu, 7 Mar 2019 18:12:07 -0500
From:   Joel Fernandes <joel@joelfernandes.org>
To:     "Enrico Weigelt, metux IT consult" <lkml@metux.net>
Cc:     Greg KH <gregkh@linuxfoundation.org>,
        Daniel Colascione <dancol@google.com>,
        "H. Peter Anvin" <hpa@zytor.com>, Pavel Machek <pavel@ucw.cz>,
        linux-kernel <linux-kernel@vger.kernel.org>,
        Andrew Morton <akpm@linux-foundation.org>, ast@kernel.org,
        atish patra <atishp04@gmail.com>,
        Borislav Petkov <bp@alien8.de>, Ingo Molnar <mingo@redhat.com>,
        Jan Kara <jack@suse.cz>, Jonathan Corbet <corbet@lwn.net>,
        Karim Yaghmour <karim.yaghmour@opersys.com>,
        Kees Cook <keescook@chromium.org>, kernel-team@android.com,
        "open list:DOCUMENTATION" <linux-doc@vger.kernel.org>,
        Manoj Rao <linux@manojrajarao.com>,
        Masahiro Yamada <yamada.masahiro@socionext.com>,
        Paul McKenney <paulmck@linux.vnet.ibm.com>,
        "Peter Zijlstra (Intel)" <peterz@infradead.org>,
        Randy Dunlap <rdunlap@infradead.org>, rostedt@goodmis.org,
        Thomas Gleixner <tglx@linutronix.de>,
        "maintainer:X86 ARCHITECTURE (32-BIT AND 64-BIT)" <x86@kernel.org>,
        yhs@fb.com
Subject: Re: [RFC] Provide in-kernel headers for making it easy to extend the
 kernel
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Enrico,

On Thu, Mar 07, 2019 at 11:11:22PM +0100, Enrico Weigelt, metux IT consult wrote:
> On 07.03.19 21:55, Greg KH wrote:
> 
> > Ick, no, no more squashfs please, let's just kill that mess once and for
> > all :)
> 
> okay, then: s/squashfs/whatever_fs_image_or_archive_you_like/;
> 
> > Again, putting this in a simple compressed tar image allows anyone to do
> > whatever they need to with this.  If they want a full filesystem,
> > uncompress it and use it there.  If they just want it in-memory where
> > they can uncompress it and then discard it, that works too.
> 
> And let me stress the point: doesn't need any kernel changes at all,
> when it's just a file in the same place where the .ko's live.

Yes, but you're missing the point that some people would also opt to build it
into the kernel during their development/debugging (Config=y). For such
folks, they don't want to update the FS with anything during debug runs
either. Your "whole same place where the .ko lives" doesn't address Daniel's
usecase. You may say "initrd", but this is a much cleaner solution to that
IMO. There is no initrd needed and the path to the header files will be at a
standard location that is already pre-decided by the kernel.

As Greg said, you are welcome to keep it disabled for yourself if you don't
want it. This doesn't affect anyone else who doesn't use it.