From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7B223C4CECD for ; Wed, 18 Sep 2019 03:09:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 51D5D218AC for ; Wed, 18 Sep 2019 03:09:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728236AbfIRDJr (ORCPT ); Tue, 17 Sep 2019 23:09:47 -0400 Received: from szxga07-in.huawei.com ([45.249.212.35]:33988 "EHLO huawei.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1728206AbfIRDJq (ORCPT ); Tue, 17 Sep 2019 23:09:46 -0400 Received: from DGGEMS413-HUB.china.huawei.com (unknown [172.30.72.58]) by Forcepoint Email with ESMTP id 5335DCD535D0C4A99B76; Wed, 18 Sep 2019 11:09:44 +0800 (CST) Received: from use12-sp2.huawei.com (10.67.189.177) by DGGEMS413-HUB.china.huawei.com (10.3.19.213) with Microsoft SMTP Server id 14.3.439.0; Wed, 18 Sep 2019 11:09:36 +0800 From: chenzefeng To: , , , , CC: , , , , , Subject: [PATCH] arm:unwind: fix incorrect backtrace with unwind_table Date: Wed, 18 Sep 2019 11:09:34 +0800 Message-ID: <1568776174-84980-1-git-send-email-chenzefeng2@huawei.com> X-Mailer: git-send-email 1.8.5.6 MIME-Version: 1.0 Content-Type: text/plain X-Originating-IP: [10.67.189.177] X-CFilter-Loop: Reflected Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org For arm, if the CONFIG_ARM_UNWIND is open, when insmod a module, the init section add to the unwind_table, the code path as follow: load_module --->post_relocation ------->module_finalize ----------->maps[ARM_SEC_INIT].txt_sec = s ----------->unwind_table_add Later if load_module success, the init section's memory will be vfree, the code path as follow: load_module --->do_init_module ------->freeinit->module_init = mod->init_layout.base ------->schedule_work(&init_free_wq) ----------->do_free_init --------------->vfree(freeinit->module_init) But after the init section's had been vfree, but it's unwind_table is not removed. The issue as follow: When insmod module A, the system alloc the "Addr1" for it's init text section, and add it to the unwind_table list, after insmod success, the "Addr1" would be vfreed. Unfortunately, later insmod module B, the system alloc the "Addr1" for it's text section, and add it to the unwind_table list, too. And we dumpstack in module B, we may get a incorrect backtrace. Signed-off-by: chenzefeng --- arch/arm/kernel/module.c | 15 ++++++++++++++- 1 file changed, 14 insertions(+), 1 deletion(-) diff --git a/arch/arm/kernel/module.c b/arch/arm/kernel/module.c index deef17f..438ed67 100644 --- a/arch/arm/kernel/module.c +++ b/arch/arm/kernel/module.c @@ -410,7 +410,20 @@ int module_finalize(const Elf32_Ehdr *hdr, const Elf_Shdr *sechdrs, int i; for (i = 0; i < ARM_SEC_MAX; i++) - if (mod->arch.unwind[i]) + if (mod->arch.unwind[i]) { unwind_table_del(mod->arch.unwind[i]); + mod->arch.unwind[i] = NULL; + } +#endif +} + +void +module_arch_freeing_init(struct module *mod) +{ +#ifdef CONFIG_ARM_UNWIND + if (mod->arch.unwind[ARM_SEC_INIT]) { + unwind_table_del(mod->arch.unwind[ARM_SEC_INIT]); + mod->arch.unwind[ARM_SEC_INIT] = NULL; + } #endif } -- 1.8.5.6