From nobody Tue Dec 16 13:53:31 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 AA434C07E98 for ; Wed, 29 Nov 2023 13:07:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233849AbjK2NHM (ORCPT ); Wed, 29 Nov 2023 08:07:12 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36210 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233384AbjK2NHD (ORCPT ); Wed, 29 Nov 2023 08:07:03 -0500 Received: from mail.loongson.cn (mail.loongson.cn [114.242.206.163]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id F38C610DA for ; Wed, 29 Nov 2023 05:07:08 -0800 (PST) Received: from loongson.cn (unknown [113.200.148.30]) by gateway (Coremail) with SMTP id _____8Cxrut7N2dlcqc9AA--.54171S3; Wed, 29 Nov 2023 21:07:07 +0800 (CST) Received: from linux.localdomain (unknown [113.200.148.30]) by localhost.localdomain (Coremail) with SMTP id AQAAf8Axzy91N2dlVtNPAA--.45987S8; Wed, 29 Nov 2023 21:07:07 +0800 (CST) From: Tiezhu Yang To: Josh Poimboeuf , Peter Zijlstra , Huacai Chen Cc: loongarch@lists.linux.dev, linux-kernel@vger.kernel.org Subject: [PATCH v5 6/8] objtool: Check local label in add_dead_ends() Date: Wed, 29 Nov 2023 21:06:59 +0800 Message-ID: <20231129130701.27744-7-yangtiezhu@loongson.cn> X-Mailer: git-send-email 2.42.0 In-Reply-To: <20231129130701.27744-1-yangtiezhu@loongson.cn> References: <20231129130701.27744-1-yangtiezhu@loongson.cn> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-CM-TRANSID: AQAAf8Axzy91N2dlVtNPAA--.45987S8 X-CM-SenderInfo: p1dqw3xlh2x3gn0dqz5rrqw2lrqou0/ X-Coremail-Antispam: 1Uk129KBj93XoWxWryUXry8JF1rCw47Gr1fKrX_yoWrXry8pF 43C343Kr42vr13Zw47tFyxWasxWws7WFnrJ3y7GF1rAry2van0gw12yw15Zas8Gr12vw45 XayYgay3uryDAwcCm3ZEXasCq-sJn29KB7ZKAUJUUUUr529EdanIXcx71UUUUU7KY7ZEXa sCq-sGcSsGvfJ3Ic02F40EFcxC0VAKzVAqx4xG6I80ebIjqfuFe4nvWSU5nxnvy29KBjDU 0xBIdaVrnRJUUU9Fb4IE77IF4wAFF20E14v26r1j6r4UM7CY07I20VC2zVCF04k26cxKx2 IYs7xG6rWj6s0DM7CIcVAFz4kK6r126r13M28lY4IEw2IIxxk0rwA2F7IY1VAKz4vEj48v e4kI8wA2z4x0Y4vE2Ix0cI8IcVAFwI0_Xr0_Ar1l84ACjcxK6xIIjxv20xvEc7CjxVAFwI 0_Gr0_Cr1l84ACjcxK6I8E87Iv67AKxVW8Jr0_Cr1UM28EF7xvwVC2z280aVCY1x0267AK xVW8Jr0_Cr1UM2kKe7AKxVWUXVWUAwAS0I0E0xvYzxvE52x082IY62kv0487Mc804VCY07 AIYIkI8VC2zVCFFI0UMc02F40EFcxC0VAKzVAqx4xG6I80ewAv7VC0I7IYx2IY67AKxVWU tVWrXwAv7VC2z280aVAFwI0_Gr0_Cr1lOx8S6xCaFVCjc4AY6r1j6r4UM4x0Y48IcxkI7V AKI48JMxAIw28IcxkI7VAKI48JMxC20s026xCaFVCjc4AY6r1j6r4UMxCIbckI1I0E14v2 6r1Y6r17MI8I3I0E5I8CrVAFwI0_Jr0_Jr4lx2IqxVCjr7xvwVAFwI0_JrI_JrWlx4CE17 CEb7AF67AKxVWUAVWUtwCIc40Y0x0EwIxGrwCI42IY6xIIjxv20xvE14v26ryj6F1UMIIF 0xvE2Ix0cI8IcVCY1x0267AKxVW8JVWxJwCI42IY6xAIw20EY4v20xvaj40_Jr0_JF4lIx AIcVC2z280aVAFwI0_Gr0_Cr1lIxAIcVC2z280aVCY1x0267AKxVW8JVW8JrUvcSsGvfC2 KfnxnUUI43ZEXa7IU8XyCJUUUUU== Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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, like this: init/main.o: warning: objtool: unexpected relocation symbol type in .rela= .discard.unreachable We can see that the reloc sym name is local label instead of section in relocation section '.rela.discard.unreachable', 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. At the same time, replace the variable "addend" with "offset" to reflect the reality. Here are some detailed info: [fedora@linux 6.7.test]$ gcc --version gcc (GCC) 14.0.0 20231127 (experimental) [fedora@linux 6.7.test]$ as --version GNU assembler (GNU Binutils) 2.41.50.20231127 [fedora@linux 6.7.test]$ readelf -r init/main.o | grep -A 2 "rela.discard.u= nreachable" Relocation section '.rela.discard.unreachable' at offset 0x4b58 contains 1 = entry: Offset Info Type Sym. Value Sym. Name + A= ddend 000000000000 00de00000063 R_LARCH_32_PCREL 0000000000000220 .L467^B1 + 0 Signed-off-by: Tiezhu Yang --- tools/objtool/check.c | 34 +++++++++++++++++++--------------- 1 file changed, 19 insertions(+), 15 deletions(-) diff --git a/tools/objtool/check.c b/tools/objtool/check.c index 29b3c5495901..395fce41fb81 100644 --- a/tools/objtool/check.c +++ b/tools/objtool/check.c @@ -611,7 +611,7 @@ static int add_dead_ends(struct objtool_file *file) struct section *rsec; struct reloc *reloc; struct instruction *insn; - s64 addend; + unsigned long offset; =20 /* * Check for manually annotated dead ends. @@ -622,26 +622,28 @@ static int add_dead_ends(struct objtool_file *file) =20 for_each_reloc(rsec, reloc) { =20 - if (reloc->sym->type !=3D STT_SECTION) { + if (reloc->sym->type =3D=3D STT_SECTION) { + offset =3D reloc_addend(reloc); + } else if (reloc->sym->local_label) { + offset =3D reloc->sym->offset; + } else { WARN("unexpected relocation symbol type in %s", rsec->name); return -1; } =20 - addend =3D reloc_addend(reloc); - - insn =3D find_insn(file, reloc->sym->sec, addend); + insn =3D find_insn(file, reloc->sym->sec, offset); if (insn) insn =3D prev_insn_same_sec(file, insn); - else if (addend =3D=3D reloc->sym->sec->sh.sh_size) { + else if (offset =3D=3D reloc->sym->sec->sh.sh_size) { insn =3D find_last_insn(file, reloc->sym->sec); if (!insn) { WARN("can't find unreachable insn at %s+0x%" PRIx64, - reloc->sym->sec->name, addend); + reloc->sym->sec->name, offset); return -1; } } else { WARN("can't find unreachable insn at %s+0x%" PRIx64, - reloc->sym->sec->name, addend); + reloc->sym->sec->name, offset); return -1; } =20 @@ -661,26 +663,28 @@ static int add_dead_ends(struct objtool_file *file) =20 for_each_reloc(rsec, reloc) { =20 - if (reloc->sym->type !=3D STT_SECTION) { + if (reloc->sym->type =3D=3D STT_SECTION) { + offset =3D reloc_addend(reloc); + } else if (reloc->sym->local_label) { + offset =3D reloc->sym->offset; + } else { WARN("unexpected relocation symbol type in %s", rsec->name); return -1; } =20 - addend =3D reloc_addend(reloc); - - insn =3D find_insn(file, reloc->sym->sec, addend); + insn =3D find_insn(file, reloc->sym->sec, offset); if (insn) insn =3D prev_insn_same_sec(file, insn); - else if (addend =3D=3D reloc->sym->sec->sh.sh_size) { + else if (offset =3D=3D reloc->sym->sec->sh.sh_size) { insn =3D find_last_insn(file, reloc->sym->sec); if (!insn) { WARN("can't find reachable insn at %s+0x%" PRIx64, - reloc->sym->sec->name, addend); + reloc->sym->sec->name, offset); return -1; } } else { WARN("can't find reachable insn at %s+0x%" PRIx64, - reloc->sym->sec->name, addend); + reloc->sym->sec->name, offset); return -1; } =20 --=20 2.42.0