From: Peter Zijlstra <peterz@infradead.org>
To: Tiezhu Yang <yangtiezhu@loongson.cn>
Cc: Huacai Chen <chenhuacai@kernel.org>,
Josh Poimboeuf <jpoimboe@kernel.org>,
Nathan Chancellor <nathan@kernel.org>,
loongarch@lists.linux.dev, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v1 2/3] objtool/LoongArch: Fix unreachable instruction warnings about EFISTUB
Date: Mon, 1 Sep 2025 10:19:04 +0200 [thread overview]
Message-ID: <20250901081904.GB4067720@noisy.programming.kicks-ass.net> (raw)
In-Reply-To: <20250901072156.31361-3-yangtiezhu@loongson.cn>
On Mon, Sep 01, 2025 at 03:21:55PM +0800, Tiezhu Yang wrote:
> When compiling with LLVM and CONFIG_LTO_CLANG is set, there exist the
> following objtool warnings:
>
> vmlinux.o: warning: objtool: .head.text+0x0: unreachable instruction
> vmlinux.o: warning: objtool: .head.text+0x18: unreachable instruction
> vmlinux.o: warning: objtool: .head.text+0x38: unreachable instruction
> vmlinux.o: warning: objtool: .head.text+0x3c: unreachable instruction
> vmlinux.o: warning: objtool: .head.text+0x40: unreachable instruction
> vmlinux.o: warning: objtool: .head.text+0x44: unreachable instruction
> vmlinux.o: warning: objtool: .head.text+0x54: unreachable instruction
> vmlinux.o: warning: objtool: .head.text+0x58: unreachable instruction
> vmlinux.o: warning: objtool: .head.text+0x6c: unreachable instruction
> vmlinux.o: warning: objtool: .head.text+0x84: unreachable instruction
> vmlinux.o: warning: objtool: .head.text+0x94: unreachable instruction
> vmlinux.o: warning: objtool: .head.text+0x9c: unreachable instruction
> vmlinux.o: warning: objtool: .head.text+0xc4: unreachable instruction
> vmlinux.o: warning: objtool: .head.text+0xf8: unreachable instruction
> vmlinux.o: warning: objtool: .head.text+0xfc: unreachable instruction
> vmlinux.o: warning: objtool: .head.text+0x104: unreachable instruction
> vmlinux.o: warning: objtool: .head.text+0x10c: unreachable instruction
> vmlinux.o: warning: objtool: .head.text+0x11c: unreachable instruction
> vmlinux.o: warning: objtool: .head.text+0x120: unreachable instruction
> vmlinux.o: warning: objtool: .head.text+0x124: unreachable instruction
> vmlinux.o: warning: objtool: .head.text+0x144: unreachable instruction
>
> The instructions in the .head.text section are related with EFISTUB,
> they are image header and can be ignored by objtool, so just check the
> section name in ignore_unreachable_insn() to ignore it.
I am confused; why do the efi/libstub functions generate this error?
Is this zboot-header.S perhaps? Why can't we properly annotate that
file?
next prev parent reply other threads:[~2025-09-01 8:19 UTC|newest]
Thread overview: 35+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-09-01 7:21 [PATCH v1 0/3] Fix objtool warnings if LTO is enabled for LoongArch (Part 2) Tiezhu Yang
2025-09-01 7:21 ` [PATCH v1 1/3] objtool/LoongArch: Fix fall through warning about efi_boot_kernel() Tiezhu Yang
2025-09-01 8:16 ` Peter Zijlstra
2025-09-01 8:31 ` Tiezhu Yang
2025-09-03 19:17 ` Josh Poimboeuf
2025-09-04 2:15 ` Tiezhu Yang
2025-09-04 2:17 ` Huacai Chen
2025-09-04 17:26 ` Josh Poimboeuf
2025-09-05 4:33 ` Huacai Chen
2025-09-05 9:53 ` Tiezhu Yang
2025-09-01 7:21 ` [PATCH v1 2/3] objtool/LoongArch: Fix unreachable instruction warnings about EFISTUB Tiezhu Yang
2025-09-01 8:19 ` Peter Zijlstra [this message]
2025-09-01 8:39 ` Tiezhu Yang
2025-09-03 19:19 ` Josh Poimboeuf
2025-09-04 2:18 ` Tiezhu Yang
2025-09-04 2:21 ` Huacai Chen
2025-09-04 3:50 ` Tiezhu Yang
2025-09-04 3:59 ` Huacai Chen
2025-09-04 17:39 ` Josh Poimboeuf
2025-09-04 21:46 ` Josh Poimboeuf
2025-09-05 4:36 ` Huacai Chen
2025-09-05 16:04 ` Josh Poimboeuf
2025-09-09 3:59 ` Tiezhu Yang
2025-09-09 4:10 ` Huacai Chen
2025-09-09 16:05 ` Josh Poimboeuf
2025-09-10 6:55 ` Huacai Chen
2025-09-11 3:23 ` Josh Poimboeuf
2025-09-11 8:28 ` Huacai Chen
2025-09-01 7:21 ` [PATCH v1 3/3] LoongArch: Fix unreachable instruction warnings about entry functions Tiezhu Yang
2025-09-01 8:20 ` Peter Zijlstra
2025-09-03 19:22 ` Josh Poimboeuf
2025-09-04 1:26 ` Jinyang He
2025-09-04 3:18 ` Tiezhu Yang
2025-09-04 17:16 ` Josh Poimboeuf
2025-09-02 15:43 ` [PATCH v1 0/3] Fix objtool warnings if LTO is enabled for LoongArch (Part 2) Huacai Chen
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