From nobody Fri Dec 19 14:22:42 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 DD770C83F12 for ; Wed, 30 Aug 2023 03:01:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241798AbjH3DBB (ORCPT ); Tue, 29 Aug 2023 23:01:01 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48356 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230413AbjH3DAj (ORCPT ); Tue, 29 Aug 2023 23:00:39 -0400 Received: from mail.loongson.cn (mail.loongson.cn [114.242.206.163]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id C5C05185 for ; Tue, 29 Aug 2023 20:00:33 -0700 (PDT) Received: from loongson.cn (unknown [113.200.148.30]) by gateway (Coremail) with SMTP id _____8AxJujPsO5kEvgcAA--.120S3; Wed, 30 Aug 2023 11:00:31 +0800 (CST) Received: from linux.localdomain (unknown [113.200.148.30]) by localhost.localdomain (Coremail) with SMTP id AQAAf8CxF8zOsO5kVetmAA--.12565S2; Wed, 30 Aug 2023 11:00:31 +0800 (CST) From: Tiezhu Yang To: Huacai Chen Cc: loongarch@lists.linux.dev, linux-kernel@vger.kernel.org, loongson-kernel@lists.loongnix.cn Subject: [PATCH v2] LoongArch: Define the symbol fault as a local label in fpu.S Date: Wed, 30 Aug 2023 11:00:30 +0800 Message-Id: <1693364430-11337-1-git-send-email-yangtiezhu@loongson.cn> X-Mailer: git-send-email 2.1.0 X-CM-TRANSID: AQAAf8CxF8zOsO5kVetmAA--.12565S2 X-CM-SenderInfo: p1dqw3xlh2x3gn0dqz5rrqw2lrqou0/ X-Coremail-Antispam: 1Uk129KBj93XoWxZF4ftF1fKw4rJw1UXFy7urX_yoW5uF1xpF yUZrWvgr4rW3Z7Aanrtw4q9rZ8Ga9rGF47u3WqyrWxCrWjg3WDta18tryDXF12qa15JF40 qF4FqrWYq3Wqy3gCm3ZEXasCq-sJn29KB7ZKAUJUUUU3529EdanIXcx71UUUUU7KY7ZEXa sCq-sGcSsGvfJ3Ic02F40EFcxC0VAKzVAqx4xG6I80ebIjqfuFe4nvWSU5nxnvy29KBjDU 0xBIdaVrnRJUUU9Yb4IE77IF4wAFF20E14v26r1j6r4UM7CY07I20VC2zVCF04k26cxKx2 IYs7xG6rWj6s0DM7CIcVAFz4kK6r1Y6r17M28lY4IEw2IIxxk0rwA2F7IY1VAKz4vEj48v e4kI8wA2z4x0Y4vE2Ix0cI8IcVAFwI0_Xr0_Ar1l84ACjcxK6xIIjxv20xvEc7CjxVAFwI 0_Gr0_Cr1l84ACjcxK6I8E87Iv67AKxVW8Jr0_Cr1UM28EF7xvwVC2z280aVCY1x0267AK xVW8Jr0_Cr1UM2kKe7AKxVWUAVWUtwAS0I0E0xvYzxvE52x082IY62kv0487Mc804VCY07 AIYIkI8VC2zVCFFI0UMc02F40EFcxC0VAKzVAqx4xG6I80ewAv7VC0I7IYx2IY67AKxVWU AVWUtwAv7VC2z280aVAFwI0_Jr0_Gr1lOx8S6xCaFVCjc4AY6r1j6r4UM4x0Y48IcxkI7V AKI48JMxkF7I0En4kS14v26r126r1DMxAIw28IcxkI7VAKI48JMxC20s026xCaFVCjc4AY 6r1j6r4UMI8I3I0E5I8CrVAFwI0_Jr0_Jr4lx2IqxVCjr7xvwVAFwI0_JrI_JrWlx4CE17 CEb7AF67AKxVWUAVWUtwCIc40Y0x0EwIxGrwCI42IY6xIIjxv20xvE14v26r1I6r4UMIIF 0xvE2Ix0cI8IcVCY1x0267AKxVWUJVW8JwCI42IY6xAIw20EY4v20xvaj40_Jr0_JF4lIx AIcVC2z280aVAFwI0_Jr0_Gr1lIxAIcVC2z280aVCY1x0267AKxVWUJVW8JbIYCTnIWIev Ja73UjIFyTuYvjxUcbAwUUUUU 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" The initial aim is to silence the following objtool warnings: arch/loongarch/kernel/fpu.o: warning: objtool: _save_fp_context() falls t= hrough to next function fault() arch/loongarch/kernel/fpu.o: warning: objtool: _restore_fp_context() fall= s through to next function fault() arch/loongarch/kernel/fpu.o: warning: objtool: _save_lsx_context() falls = through to next function fault() arch/loongarch/kernel/fpu.o: warning: objtool: _restore_lsx_context() fal= ls through to next function fault() arch/loongarch/kernel/fpu.o: warning: objtool: _save_lasx_context() falls= through to next function fault() arch/loongarch/kernel/fpu.o: warning: objtool: _restore_lasx_context() fa= lls through to next function fault() Currently, SYM_FUNC_END() defines the symbol fault as SYM_T_FUNC which is STT_FUNC, the objtool warnings are generated through the following code: tools/objtool/include/objtool/check.h static inline struct symbol *insn_func(struct instruction *insn) { struct symbol *sym =3D insn->sym; if (sym && sym->type !=3D STT_FUNC) sym =3D NULL; return sym; } tools/objtool/check.c static int validate_branch(struct objtool_file *file, struct symbol *func, struct instruction *insn, struct insn_state state) { ... if (func && insn_func(insn) && func !=3D insn_func(insn)->pfunc) { ... WARN("%s() falls through to next function %s()", func->name, insn_func(insn)->name); return 1; } ... } We can see that the fixup can be a local label in the following code: arch/loongarch/include/asm/asm-extable.h .pushsection __ex_table, "a"; \ .balign 4; \ .long ((insn) - .); \ .long ((fixup) - .); \ .short (type); \ .short (data); \ .popsection; .macro _asm_extable, insn, fixup __ASM_EXTABLE_RAW(\insn, \fixup, EX_TYPE_FIXUP, 0) .endm Like arch/loongarch/lib/*.S, just define the symbol fault as a local label in fpu.S. Before: $ readelf -s arch/loongarch/kernel/fpu.o | awk -F: /fault/'{print $2}' 000000000000053c 8 FUNC GLOBAL DEFAULT 1 fault After: $ readelf -s arch/loongarch/kernel/fpu.o | awk -F: /fault/'{print $2}' 000000000000053c 0 NOTYPE LOCAL DEFAULT 1 .L_fixup_fpu_fault Co-developed-by: Youling Tang Signed-off-by: Youling Tang Signed-off-by: Tiezhu Yang --- Add v2 tag in this patch, please ignore the previous patch, sorry for that. There is a same issue in lbt.S, Huacai suggested to squash the changes in the original patch: "LoongArch: Add Loongson Binary Translation (LBT) extension support" arch/loongarch/kernel/fpu.S | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/arch/loongarch/kernel/fpu.S b/arch/loongarch/kernel/fpu.S index b4032de..3177725 100644 --- a/arch/loongarch/kernel/fpu.S +++ b/arch/loongarch/kernel/fpu.S @@ -22,7 +22,7 @@ =20 .macro EX insn, reg, src, offs .ex\@: \insn \reg, \src, \offs - _asm_extable .ex\@, fault + _asm_extable .ex\@, .L_fixup_fpu_fault .endm =20 .macro sc_save_fp base @@ -521,7 +521,6 @@ SYM_FUNC_START(_restore_lasx_context) jr ra SYM_FUNC_END(_restore_lasx_context) =20 -SYM_FUNC_START(fault) +.L_fixup_fpu_fault: li.w a0, -EFAULT # failure jr ra -SYM_FUNC_END(fault) --=20 2.1.0