From nobody Fri Oct 3 13:34:13 2025 Received: from mail.loongson.cn (mail.loongson.cn [114.242.206.163]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 0F53E1F582B for ; Mon, 1 Sep 2025 07:22:04 +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=1756711327; cv=none; b=ENI/7uw7PlNOHFW9b3HDMi0wmftV60so1Xew6w0HpiF3l4ZqxRjCgZ/sSTAv11Vkp3p5zbNeKXBEwfwGEdryAakM9rkmjWtBA/aa24ecpyJ/iv1yf8EugI4sRBCTITxxbrQT3z0sWlJYZJko7+l+lsdcD4WovqYDMmaWaTpdY80= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756711327; c=relaxed/simple; bh=yDz+grzfuSXFL1I6+ka8l/Oc6n/W6Hy1mLlCIP3m+kw=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=PuqQGyi9ioazmlDu/gmF35fQcc39FrNlRBLempdmZT0pdV6Hb/C8A4waaCApZ347FXrGIIsCsJtCf5BdpqhFhinQ/Til4b9NvnJ8SLqsCadZCiLxvMWkdwFrRIHr+8DBoY97fhIXvJPkqKiqYAvWN2dTBaJbAa2tYMyBufoL+Z4= 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 _____8DxP9OaSbVoCkUFAA--.10581S3; Mon, 01 Sep 2025 15:22:02 +0800 (CST) Received: from linux.localdomain (unknown [113.200.148.30]) by front1 (Coremail) with SMTP id qMiowJAxE+SVSbVoxHB2AA--.44622S3; Mon, 01 Sep 2025 15:22:01 +0800 (CST) From: Tiezhu Yang To: Huacai Chen , Josh Poimboeuf , Peter Zijlstra , Nathan Chancellor Cc: loongarch@lists.linux.dev, linux-kernel@vger.kernel.org Subject: [PATCH v1 1/3] objtool/LoongArch: Fix fall through warning about efi_boot_kernel() Date: Mon, 1 Sep 2025 15:21:54 +0800 Message-ID: <20250901072156.31361-2-yangtiezhu@loongson.cn> X-Mailer: git-send-email 2.42.0 In-Reply-To: <20250901072156.31361-1-yangtiezhu@loongson.cn> References: <20250901072156.31361-1-yangtiezhu@loongson.cn> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-CM-TRANSID: qMiowJAxE+SVSbVoxHB2AA--.44622S3 X-CM-SenderInfo: p1dqw3xlh2x3gn0dqz5rrqw2lrqou0/ X-Coremail-Antispam: 1Uk129KBj93XoW7AryrKr1fKry3XrW7tryktFc_yoW8GryrpF WUCrWjkrWYgrZ8K3WDJa1Igry5CwsFqr17Gry8Wa9rA390vFnxtw4akr10va9Fqrn3Ww1I qayjgF9IkayqyagCm3ZEXasCq-sJn29KB7ZKAUJUUUUr529EdanIXcx71UUUUU7KY7ZEXa sCq-sGcSsGvfJ3Ic02F40EFcxC0VAKzVAqx4xG6I80ebIjqfuFe4nvWSU5nxnvy29KBjDU 0xBIdaVrnRJUUUBFb4IE77IF4wAFF20E14v26r1j6r4UM7CY07I20VC2zVCF04k26cxKx2 IYs7xG6rWj6s0DM7CIcVAFz4kK6r126r13M28lY4IEw2IIxxk0rwA2F7IY1VAKz4vEj48v e4kI8wA2z4x0Y4vE2Ix0cI8IcVAFwI0_Xr0_Ar1l84ACjcxK6xIIjxv20xvEc7CjxVAFwI 0_Gr0_Cr1l84ACjcxK6I8E87Iv67AKxVWxJr0_GcWl84ACjcxK6I8E87Iv6xkF7I0E14v2 6F4UJVW0owAaw2AFwI0_Jrv_JF1le2I262IYc4CY6c8Ij28IcVAaY2xG8wAqjxCEc2xF0c Ia020Ex4CE44I27wAqx4xG64xvF2IEw4CE5I8CrVC2j2WlYx0E2Ix0cI8IcVAFwI0_JF0_ Jw1lYx0Ex4A2jsIE14v26r4j6F4UMcvjeVCFs4IE7xkEbVWUJVW8JwACjcxG0xvY0x0EwI xGrwCY1x0262kKe7AKxVWUAVWUtwCF04k20xvY0x0EwIxGrwCFx2IqxVCFs4IE7xkEbVWU JVW8JwCFI7km07C267AKxVWUXVWUAwC20s026c02F40E14v26r1j6r18MI8I3I0E7480Y4 vE14v26r106r1rMI8E67AF67kF1VAFwI0_JF0_Jw1lIxkGc2Ij64vIr41lIxAIcVC0I7IY x2IY67AKxVWUCVW8JwCI42IY6xIIjxv20xvEc7CjxVAFwI0_Gr0_Cr1lIxAIcVCF04k26c xKx2IYs7xG6r1j6r1xMIIF0xvEx4A2jsIE14v26r4j6F4UMIIF0xvEx4A2jsIEc7CjxVAF wI0_Gr0_Gr1UYxBIdaVFxhVjvjDU0xZFpf9x07jFiihUUUUU= Content-Type: text/plain; charset="utf-8" When compiling with LLVM and CONFIG_LTO_CLANG is set, there exists the following objtool warning: vmlinux.o: warning: objtool: __efistub_efi_boot_kernel() falls through to next function __efistub_exit_boot_func() This is because efi_boot_kernel() doesn't end with a return instruction or an unconditional jump, then objtool has determined that the function can fall through into the next function. At the beginning, try to do something to make efi_boot_kernel() ends with an unconditional jump instruction, but it is not a proper way. After more analysis, one simple way is to ignore these EFISTUB functions in validate_branch() of objtool since they are useless for stack unwinder. Signed-off-by: Tiezhu Yang --- tools/objtool/check.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/tools/objtool/check.c b/tools/objtool/check.c index d14f20ef1db1..2dcebf75d95e 100644 --- a/tools/objtool/check.c +++ b/tools/objtool/check.c @@ -3567,6 +3567,10 @@ static int validate_branch(struct objtool_file *file= , struct symbol *func, !strncmp(func->name, "__pfx_", 6)) return 0; =20 + /* Ignore EFISTUB functions which are useless for stack unwinder */ + if (!strncmp(func->name, "__efistub_", 10)) + return 0; + if (file->ignore_unreachables) return 0; =20 --=20 2.42.0