From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail.loongson.cn (mail.loongson.cn [114.242.206.163]) by smtp.subspace.kernel.org (Postfix) with ESMTP id CAE6814B977 for ; Tue, 26 Aug 2025 12:30:27 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=114.242.206.163 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756211430; cv=none; b=b7VAuASF5csnIA20fKITbgGUFkRZ3n+EH/h67hRsCS+86SrdzcX1V07AEACA4gF7cr/54RaaNHXo5aV8sAgjI07pHcPDYCyBB5Wa9Vgpp9u6soda/6De4/rM/6TQYb8sdOdSMgK595N8qgIsYQBfmkq7llHulOQbWdPuoY+4tNc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756211430; c=relaxed/simple; bh=vi9HxGRPG4Osqc5VgRy7CzXqp8laDNkYadtP54HwQoM=; h=Subject:To:Cc:References:From:Message-ID:Date:MIME-Version: In-Reply-To:Content-Type; b=G6LQPlQSNGI6iSN9HQd2PY2qXj40Z/5WWtsE20l2xlrC9zH0uLgnyw/afQTxJUKIr1rQK3EchkO1PsK+eyvDrndbmDlgcRuPoO7++tpJHxqRbau337yPqUolLRNld4JROJk5u7qqhGLO4cZM1husOV42eWZeEAEFnp/iT6XLRk4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=loongson.cn; spf=pass smtp.mailfrom=loongson.cn; arc=none smtp.client-ip=114.242.206.163 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=loongson.cn Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=loongson.cn Received: from loongson.cn (unknown [113.200.148.30]) by gateway (Coremail) with SMTP id _____8DxN9HhqK1ou1wDAA--.6573S3; Tue, 26 Aug 2025 20:30:25 +0800 (CST) Received: from [10.130.10.66] (unknown [113.200.148.30]) by front1 (Coremail) with SMTP id qMiowJAxT+bgqK1opP9pAA--.65380S3; Tue, 26 Aug 2025 20:30:24 +0800 (CST) Subject: Re: [RFC PATCH 2/2] objtool/LoongArch: Fix unreachable instruction warnings about head.S To: Huacai Chen Cc: Josh Poimboeuf , Peter Zijlstra , Nathan Chancellor , loongarch@lists.linux.dev, linux-kernel@vger.kernel.org References: <20250826064631.9617-1-yangtiezhu@loongson.cn> <20250826064631.9617-3-yangtiezhu@loongson.cn> From: Tiezhu Yang Message-ID: Date: Tue, 26 Aug 2025 20:30:23 +0800 User-Agent: Mozilla/5.0 (X11; Linux loongarch64; rv:68.0) Gecko/20100101 Thunderbird/68.7.0 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 8bit X-CM-TRANSID:qMiowJAxT+bgqK1opP9pAA--.65380S3 X-CM-SenderInfo: p1dqw3xlh2x3gn0dqz5rrqw2lrqou0/ X-Coremail-Antispam: 1Uk129KBj9xXoWruFWkWF47Gr1kZr4UuFyrXwc_yoWkCFg_ur 17uw48W3y8Jayqvw1DKasxuw1UZanY9F4FyrykZrZFv3WrJry5Xr47Jw1rurn8Kr4kGrZ8 A39Ygas3Ar1UtosvyTuYvTs0mTUanT9S1TB71UUUUUDqnTZGkaVYY2UrUUUUj1kv1TuYvT s0mT0YCTnIWjqI5I8CrVACY4xI64kE6c02F40Ex7xfYxn0WfASr-VFAUDa7-sFnT9fnUUI cSsGvfJTRUUUb3AYFVCjjxCrM7AC8VAFwI0_Jr0_Gr1l1xkIjI8I6I8E6xAIw20EY4v20x vaj40_Wr0E3s1l1IIY67AEw4v_Jrv_JF1l8cAvFVAK0II2c7xJM28CjxkF64kEwVA0rcxS w2x7M28EF7xvwVC0I7IYx2IY67AKxVW5JVW7JwA2z4x0Y4vE2Ix0cI8IcVCY1x0267AKxV W8JVWxJwA2z4x0Y4vEx4A2jsIE14v26rxl6s0DM28EF7xvwVC2z280aVCY1x0267AKxVW0 oVCq3wAS0I0E0xvYzxvE52x082IY62kv0487Mc804VCY07AIYIkI8VC2zVCFFI0UMc02F4 0EFcxC0VAKzVAqx4xG6I80ewAv7VC0I7IYx2IY67AKxVWUAVWUtwAv7VC2z280aVAFwI0_ Gr0_Cr1lOx8S6xCaFVCjc4AY6r1j6r4UM4x0Y48IcVAKI48JMxk0xIA0c2IEe2xFo4CEbI xvr21l42xK82IYc2Ij64vIr41l4I8I3I0E4IkC6x0Yz7v_Jr0_Gr1l4IxYO2xFxVAFwI0_ JF0_Jw1lx2IqxVAqx4xG67AKxVWUJVWUGwC20s026x8GjcxK67AKxVWUGVWUWwC2zVAF1V AY17CE14v26r126r1DMIIYrxkI7VAKI48JMIIF0xvE2Ix0cI8IcVAFwI0_JFI_Gr1lIxAI cVC0I7IYx2IY6xkF7I0E14v26r1j6r4UMIIF0xvE42xK8VAvwI8IcIk0rVWUJVWUCwCI42 IY6I8E87Iv67AKxVW8JVWxJwCI42IY6I8E87Iv6xkF7I0E14v26r4j6r4UJbIYCTnIWIev Ja73UjIFyTuYvjxUcDDGUUUUU On 2025/8/26 下午4:26, Huacai Chen wrote: > On Tue, Aug 26, 2025 at 2:46 PM Tiezhu Yang wrote: >> >> When compiling with LLVM and CONFIG_LTO_CLANG is set, there exist the >> following objtool warnings after silencing all of the other warnings: ... >> arch/loongarch/kernel/head.S | 8 ++++---- >> 1 file changed, 4 insertions(+), 4 deletions(-) >> >> diff --git a/arch/loongarch/kernel/head.S b/arch/loongarch/kernel/head.S >> index e3865e92a917..566a1dbf5fa0 100644 >> --- a/arch/loongarch/kernel/head.S >> +++ b/arch/loongarch/kernel/head.S >> @@ -20,6 +20,7 @@ >> __HEAD >> >> _head: >> + UNWIND_HINT_UNDEFINED >> .word IMAGE_DOS_SIGNATURE /* "MZ", MS-DOS header */ >> .org 0x8 >> .dword _kernel_entry /* Kernel entry point (physical address) */ >> @@ -30,6 +31,7 @@ _head: >> .long pe_header - _head /* Offset to the PE header */ >> >> pe_header: >> + UNWIND_HINT_UNDEFINED >> __EFI_PE_HEADER > The efi header is completely not code, the annotations are very strange. Yes, I think so too, but the aim is only to not checking for objtool, it seems no other better way. Thanks, Tiezhu