Re: [PATCH v2] efistub: Only link libstub to final vmlinux

From: Huacai Chen <chenhuacai@kernel.org>
To: Josh Poimboeuf <jpoimboe@kernel.org>,
	Catalin Marinas <catalin.marinas@arm.com>,
	 Will Deacon <will@kernel.org>, Paul Walmsley <pjw@kernel.org>,
	Palmer Dabbelt <palmer@dabbelt.com>,
	 Albert Ou <aou@eecs.berkeley.edu>,
	 "Madhavan T. Venkataraman" <madvenka@linux.microsoft.com>
Cc: Tiezhu Yang <yangtiezhu@loongson.cn>,
	Ard Biesheuvel <ardb@kernel.org>,
	loongarch@lists.linux.dev,  linux-arm-kernel@lists.infradead.org,
	linux-riscv@lists.infradead.org,  linux-efi@vger.kernel.org,
	linux-kbuild@vger.kernel.org,  linux-kernel@vger.kernel.org
Subject: Re: [PATCH v2] efistub: Only link libstub to final vmlinux
Date: Sat, 15 Nov 2025 11:16:42 +0800	[thread overview]
Message-ID: <CAAhV-H47fzaKcMhgLWWOTxB+srBsg85-eK0LW1vQXQnvq32-+w@mail.gmail.com> (raw)
In-Reply-To: <32s3lvzfu6jkyho7qenrqbsm5wkgjnzn2imdp6tfwycmyxpzgu@kg5367uxmxii>

On Wed, Nov 12, 2025 at 2:00 AM Josh Poimboeuf <jpoimboe@kernel.org> wrote:
>
> On Mon, Nov 10, 2025 at 03:00:00PM +0800, Huacai Chen wrote:
> > On Mon, Nov 10, 2025 at 9:19 AM Tiezhu Yang <yangtiezhu@loongson.cn> wrote:
> > > If I understand correctly, I should modify this patch to remove the
> > > changes of arm and riscv for now, do the changes only when there is
> > > a real problem or requirement some day, right? If no more comments,
> > > I will send v3 later.
> >
> > Now everyone involved agrees that the efistub code is correct, so the
> > proper solution is to fix the compiler.
>
> Hm?  I don't see how it's a compiler bug.  It's really just an objtool
> limitation.
>
> > Changing efistub code and changing objtool (ignore __efistub prefix)
> > are both workarounds, but I think changing objtool is a little more
> > reasonable. Maybe Josh has different ideas?
>
> I thought the conversation had converged on what Tiezhu mentioned above,
> which is to skip objtool on libstub for loongarch, but leave the other
> arches alone.  That way objtool behavior is consistent between loongarch
> and x86, and objtool doesn't need to ignore any prefixes.
>
> So basically, the v2 patch minus the arm64/riscv changes.

Hi, ARM64 and RISC-V maintainers,

Would you mind that this patch modifies the three architectures
together (they are exactly the same style now)?

Madhavan is the author of ARM64's objtool, I think your opinion is
also very important.

Huacai

>
> --
> Josh

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