From nobody Thu Dec 18 04:43:54 2025 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 11D03C001E0 for ; Fri, 20 Oct 2023 02:27:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1346895AbjJTC11 (ORCPT ); Thu, 19 Oct 2023 22:27:27 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38604 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1346854AbjJTC1N (ORCPT ); Thu, 19 Oct 2023 22:27:13 -0400 Received: from mail.loongson.cn (mail.loongson.cn [114.242.206.163]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 20FB2124 for ; Thu, 19 Oct 2023 19:27:10 -0700 (PDT) Received: from loongson.cn (unknown [113.200.148.30]) by gateway (Coremail) with SMTP id _____8BxpPB75TFlTF8zAA--.34366S3; Fri, 20 Oct 2023 10:27:07 +0800 (CST) Received: from linux.localdomain (unknown [113.200.148.30]) by localhost.localdomain (Coremail) with SMTP id AQAAf8CxP9115TFl7r4rAA--.28791S9; Fri, 20 Oct 2023 10:27:07 +0800 (CST) From: Tiezhu Yang To: Josh Poimboeuf , Peter Zijlstra , Huacai Chen Cc: loongarch@lists.linux.dev, linux-kernel@vger.kernel.org, loongson-kernel@lists.loongnix.cn Subject: [PATCH v3 7/8] objtool: Check local label in read_unwind_hints() Date: Fri, 20 Oct 2023 10:27:00 +0800 Message-Id: <1697768821-22931-8-git-send-email-yangtiezhu@loongson.cn> X-Mailer: git-send-email 2.1.0 In-Reply-To: <1697768821-22931-1-git-send-email-yangtiezhu@loongson.cn> References: <1697768821-22931-1-git-send-email-yangtiezhu@loongson.cn> X-CM-TRANSID: AQAAf8CxP9115TFl7r4rAA--.28791S9 X-CM-SenderInfo: p1dqw3xlh2x3gn0dqz5rrqw2lrqou0/ X-Coremail-Antispam: 1Uk129KBj93XoW7KFyrZw45KFWrCw4xWF47ZFc_yoW8trW5pF W3C34agr40qry7uw17tFy8WasxKws7CF17trZrGr4rAry2qw15KF9Iyr15tF9rWr15uw47 XF98Ka4293WqyabCm3ZEXasCq-sJn29KB7ZKAUJUUUU7529EdanIXcx71UUUUU7KY7ZEXa sCq-sGcSsGvfJ3Ic02F40EFcxC0VAKzVAqx4xG6I80ebIjqfuFe4nvWSU5nxnvy29KBjDU 0xBIdaVrnRJUUUBIb4IE77IF4wAFF20E14v26r1j6r4UM7CY07I20VC2zVCF04k26cxKx2 IYs7xG6rWj6s0DM7CIcVAFz4kK6r1q6r4UM28lY4IEw2IIxxk0rwA2F7IY1VAKz4vEj48v e4kI8wA2z4x0Y4vE2Ix0cI8IcVAFwI0_Xr0_Ar1l84ACjcxK6xIIjxv20xvEc7CjxVAFwI 0_Gr0_Cr1l84ACjcxK6I8E87Iv67AKxVW8Jr0_Cr1UM28EF7xvwVC2z280aVCY1x0267AK xVW8Jr0_Cr1UM2kKe7AKxVWUXVWUAwAS0I0E0xvYzxvE52x082IY62kv0487Mc804VCY07 AIYIkI8VC2zVCFFI0UMc02F40EFcxC0VAKzVAqx4xG6I80ewAv7VC0I7IYx2IY67AKxVWr XVW3AwAv7VC2z280aVAFwI0_Gr0_Cr1lOx8S6xCaFVCjc4AY6r1j6r4UM4x0Y48IcxkI7V AKI48JMxkF7I0En4kS14v26r126r1DMxAIw28IcxkI7VAKI48JMxC20s026xCaFVCjc4AY 6r1j6r4UMxCIbckI1I0E14v26r1Y6r17MI8I3I0E5I8CrVAFwI0_Jr0_Jr4lx2IqxVCjr7 xvwVAFwI0_JrI_JrWlx4CE17CEb7AF67AKxVWUAVWUtwCIc40Y0x0EwIxGrwCI42IY6xII jxv20xvE14v26ryj6F1UMIIF0xvE2Ix0cI8IcVCY1x0267AKxVW8JVWxJwCI42IY6xAIw2 0EY4v20xvaj40_Jr0_JF4lIxAIcVC2z280aVAFwI0_Gr0_Cr1lIxAIcVC2z280aVCY1x02 67AKxVW8JVW8JrUvcSsGvfC2KfnxnUUI43ZEXa7IU8CzutUUUUU== Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" When update the latest upstream gcc and binutils which enables linker relaxation by default, it generates more objtool warnings on LoongArch. We can see that the reloc sym name is local label instead of section in relocation section '.rela.discard.unwind_hints', in this case, the reloc sym type is STT_NOTYPE instead of STT_SECTION. Let us check it to not return -1, then use reloc->sym->offset instead of reloc addend which is 0 to find the corresponding instruction. Here are some detailed info: [fedora@linux 6.6.test]$ gcc --version gcc (GCC) 14.0.0 20231009 (experimental) [fedora@linux 6.6.test]$ as --version GNU assembler (GNU Binutils) 2.41.50.20231009 [fedora@linux 6.6.test]$ readelf -r arch/loongarch/kernel/entry.o | grep -A= 2 "rela.discard.unwind_hints" Relocation section '.rela.discard.unwind_hints' at offset 0x458 contains 7 = entries: Offset Info Type Sym. Value Sym. Name + A= ddend 000000000000 000800000063 R_LARCH_32_PCREL 000000000000001c .Lhere_1 + 0 Signed-off-by: Tiezhu Yang --- tools/objtool/check.c | 13 ++++++++++++- 1 file changed, 12 insertions(+), 1 deletion(-) diff --git a/tools/objtool/check.c b/tools/objtool/check.c index eee5621..607a745 100644 --- a/tools/objtool/check.c +++ b/tools/objtool/check.c @@ -2227,6 +2227,7 @@ static int read_unwind_hints(struct objtool_file *fil= e) struct unwind_hint *hint; struct instruction *insn; struct reloc *reloc; + unsigned long offset; int i; =20 sec =3D find_section_by_name(file->elf, ".discard.unwind_hints"); @@ -2254,7 +2255,17 @@ static int read_unwind_hints(struct objtool_file *fi= le) return -1; } =20 - insn =3D find_insn(file, reloc->sym->sec, reloc_addend(reloc)); + if (reloc->sym->type =3D=3D STT_SECTION) { + offset =3D reloc_addend(reloc); + } else if ((reloc->sym->type =3D=3D STT_NOTYPE) && + strncmp(reloc->sym->name, ".L", 2) =3D=3D 0) { + offset =3D reloc->sym->offset; + } else { + WARN("unexpected relocation symbol type in %s", sec->rsec->name); + return -1; + } + + insn =3D find_insn(file, reloc->sym->sec, offset); if (!insn) { WARN("can't find insn for unwind_hints[%d]", i); return -1; --=20 2.1.0