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From: Breno Leitao <leitao@debian.org>
To: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>,
	 Nathan Chancellor <nathan@kernel.org>,
	paulmck@kernel.org, Nicolas Schier <nsc@kernel.org>,
	 Thomas Gleixner <tglx@kernel.org>,
	Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
	 Dave Hansen <dave.hansen@linux.intel.com>,
	x86@kernel.org, "H. Peter Anvin" <hpa@zytor.com>,
	 linux-kernel@vger.kernel.org,
	linux-trace-kernel@vger.kernel.org, linux-kbuild@vger.kernel.org,
	 bpf@vger.kernel.org, kernel-team@meta.com
Subject: Re: [PATCH 0/4] bootconfig: embed kernel.* cmdline at build time
Date: Mon, 1 Jun 2026 10:56:27 -0700	[thread overview]
Message-ID: <ah3HwIwXpxTVTtFz@gmail.com> (raw)
In-Reply-To: <20260529001519.14ca9dbe92fb2622249137c6@kernel.org>

On Fri, May 29, 2026 at 12:15:19AM +0900, Masami Hiramatsu wrote:
> On Wed, 27 May 2026 09:41:33 -0700
> Breno Leitao <leitao@debian.org> wrote:
> 
> > The userspace pieces (xbc_snprint_cmdline() in lib/, tools/bootconfig -C)
> > already landed; this series wires the rendered cmdline into the kernel.
> > 
> > Motivation: today the embedded bootconfig is parsed at runtime, after
> > parse_early_param() has already run, so early_param() handlers can't
> > see embedded values. Folding the kernel.* subtree into the cmdline at
> > build time gives a CONFIG_CMDLINE-equivalent for embedded-bootconfig
> > users without forcing them to maintain two cmdline sources.
> > 
> > Behaviorally, the "kernel" subtree is rendered to a flat string at
> > build time and stashed in .init.rodata. setup_arch() prepends it to
> > boot_command_line before parse_early_param() runs. Overflow is a soft
> > error: the helper logs and leaves boot_command_line untouched rather
> > than panicking, so an oversized embedded bconf cannot brick a boot.
> > 
> 
> Thanks Breno, yes, that is what I think about.
> Let me check it. And could you also check Sashiko's comments?

yes, I've spent some time on them, and it reported some good points, in
fact. I will fix those and resend.

Thanks!
--breno

      parent reply	other threads:[~2026-06-01 17:56 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-05-27 16:41 [PATCH 0/4] bootconfig: embed kernel.* cmdline at build time Breno Leitao
2026-05-27 16:41 ` [PATCH 1/4] bootconfig: return 0 from xbc_snprint_cmdline() for a leaf root Breno Leitao
2026-05-27 16:41 ` [PATCH 2/4] bootconfig: render embedded bootconfig as a kernel cmdline at build time Breno Leitao
2026-05-27 16:41 ` [PATCH 3/4] bootconfig: add xbc_prepend_embedded_cmdline() helper Breno Leitao
2026-05-27 16:41 ` [PATCH 4/4] x86/setup: prepend embedded bootconfig cmdline before parse_early_param Breno Leitao
2026-05-28 15:15 ` [PATCH 0/4] bootconfig: embed kernel.* cmdline at build time Masami Hiramatsu
2026-05-28 16:14   ` Breno Leitao
2026-06-01 17:56   ` Breno Leitao [this message]

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