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Date:   Mon, 31 Jul 2023 16:30:09 -0700
From:   "Paul E. McKenney" <paulmck@kernel.org>
To:     akpm@linux-foundation.org, adobriyan@gmail.com, mhiramat@kernel.org
Cc:     arnd@kernel.org, ndesaulniers@google.com, sfr@canb.auug.org.au,
        linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org,
        kernel-team@meta.com
Subject: [PATCH RFC v2 bootconfig 0/3] Distinguish bootloader and embedded
 kernel parameters
Message-ID: <db98cbbf-2205-40d2-9fa1-f1c135cc151c@paulmck-laptop>
Reply-To: paulmck@kernel.org
References: <197cba95-3989-4d2f-a9f1-8b192ad08c49@paulmck-laptop>
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On Thu, Jul 27, 2023 at 08:35:10PM -0700, Paul E. McKenney wrote:
Hello!

This series provides a /proc interface parallel to /proc/cmdline that
provides only those kernel boot parameters that were provided by the
bootloader in a new /proc/cmdline_load.  This is especially important
when these parameters are presented to the boot loader by automation
that might gather them from diverse sources, and also when a kexec-based
reboot process pulls the kernel boot parameters from /proc.  If such a
reboot process uses /proc/cmdline, the kernel parameters from the image
are replicated on every reboot, which can be frustrating when the new
kernel has different embedded kernel boot parameters.

Why put these in /proc?  Because they is quite similar to /proc/cmdline,
so it makes sense to put it in the same place that /proc/cmdline is
located.

1.	Update /proc/cmdline documentation to include boot config.

2.	fs/proc: Add /proc/cmdline_load for boot loader arguments.

3.	Add /proc/bootconfig to proc.rst.

Changes since v1:

o	Dropped /proc/cmdline_image in favor of the existing
	/proc/bootconfig.

o	Pulled in fixes from Stephen and Arnd.

o	Added documentation for /proc/bootconfig.

						Thanx, Paul

------------------------------------------------------------------------

 Documentation/filesystems/proc.rst   |    2 ++
 b/Documentation/filesystems/proc.rst |    3 ++-
 b/fs/proc/cmdline.c                  |   13 +++++++++++++
 b/include/linux/init.h               |    3 ++-
 b/init/main.c                        |    2 +-
 5 files changed, 20 insertions(+), 3 deletions(-)