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Date: Mon, 20 Oct 2025 11:51:32 -0700
From: Andrew Morton <akpm@linux-foundation.org>
To: Douglas Anderson <dianders@chromium.org>
Cc: linux-kernel@vger.kernel.org, Andrew Chant <achant@google.com>,
 Alexander Shishkin <alexander.shishkin@linux.intel.com>, Brian Gerst
 <brgerst@gmail.com>, Christian Brauner <brauner@kernel.org>, Francesco
 Valla <francesco@valla.it>, Geert Uytterhoeven <geert+renesas@glider.be>,
 Guo Weikang <guoweikang.kernel@gmail.com>, Huacai Chen
 <chenhuacai@kernel.org>, Jan Hendrik Farr <kernel@jfarr.cc>, Jeff Xu
 <jeffxu@chromium.org>, Kees Cook <kees@kernel.org>, Masahiro Yamada
 <masahiroy@kernel.org>, Michal =?ISO-8859-1?Q?Koutn=FD?=
 <mkoutny@suse.com>, Miguel Ojeda <ojeda@kernel.org>,
 "Mike Rapoport (Microsoft)" <rppt@kernel.org>, Nathan Chancellor
 <nathan@kernel.org>, Peter Zijlstra <peterz@infradead.org>, Randy Dunlap
 <rdunlap@infradead.org>, Shakeel Butt <shakeel.butt@linux.dev>, Tejun Heo
 <tj@kernel.org>, Thomas Gleixner <tglx@linutronix.de>, Thomas
 =?ISO-8859-1?Q?Wei=DFschuh?= <thomas.weissschuh@linutronix.de>,
 "Uladzislau Rezki (Sony)" <urezki@gmail.com>
Subject: Re: [PATCH] init/main.c: Wrap long kernel cmdline when printing to
 logs
Message-Id: <20251020115132.10897a599c8fbda4829b3f89@linux-foundation.org>
In-Reply-To: <20251019100605.1.I095f1e2c6c27f9f4de0b4841f725f356c643a13f@changeid>
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On Sun, 19 Oct 2025 10:06:14 -0700 Douglas Anderson <dianders@chromium.org> wrote:

> The kernel cmdline length is allowed to be longer than what printk can
> handle. When this happens the cmdline that's printed to the kernel
> ring buffer at bootup is cutoff and some kernel cmdline options are
> "hidden" from the logs. This undercuts the usefulness of the log
> message.
> 
> Add wrapping to the printout. 

Do we really need the wrapping?  That will confuse anything which
parses the output expecting a single line.

And the code would presumably be much simpler if we simply chunked up
the printing and spat out one really long line.