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=-10.5 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING, NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 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 D5F82C4338F for ; Fri, 23 Jul 2021 01:36:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B336760EB5 for ; Fri, 23 Jul 2021 01:36:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233118AbhGWA4Q (ORCPT ); Thu, 22 Jul 2021 20:56:16 -0400 Received: from szxga01-in.huawei.com ([45.249.212.187]:15049 "EHLO szxga01-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232892AbhGWA4P (ORCPT ); Thu, 22 Jul 2021 20:56:15 -0400 Received: from dggemv703-chm.china.huawei.com (unknown [172.30.72.57]) by szxga01-in.huawei.com (SkyGuard) with ESMTP id 4GWBfX0L1GzZqYQ; Fri, 23 Jul 2021 09:33:24 +0800 (CST) Received: from dggpemm000001.china.huawei.com (7.185.36.245) by dggemv703-chm.china.huawei.com (10.3.19.46) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2176.2; Fri, 23 Jul 2021 09:36:48 +0800 Received: from [10.174.177.250] (10.174.177.250) by dggpemm000001.china.huawei.com (7.185.36.245) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2176.2; Fri, 23 Jul 2021 09:36:47 +0800 Subject: Re: [PATCH -next v2] riscv: add VMAP_STACK overflow detection To: Jisheng Zhang , Andreas Schwab References: <87bl6yrcmd.fsf@igel.home> <20210722213724.1f12a0e7@xhacker> <87zguexslf.fsf@igel.home> <20210723075432.098634a2@xhacker> CC: Atish Patra , Palmer Dabbelt , Paul Walmsley , Albert Ou , linux-riscv , "linux-kernel@vger.kernel.org List" From: tongtiangen Message-ID: <52e3626a-2b40-bda6-de0e-68ea12a86dd9@huawei.com> Date: Fri, 23 Jul 2021 09:36:47 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:45.0) Gecko/20100101 Thunderbird/45.7.1 MIME-Version: 1.0 In-Reply-To: <20210723075432.098634a2@xhacker> Content-Type: text/plain; charset="UTF-8"; format=flowed Content-Transfer-Encoding: 8bit X-Originating-IP: [10.174.177.250] X-ClientProxiedBy: dggems703-chm.china.huawei.com (10.3.19.180) To dggpemm000001.china.huawei.com (7.185.36.245) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2021/7/23 7:54, Jisheng Zhang wrote: > On Thu, 22 Jul 2021 17:42:52 +0200 > Andreas Schwab wrote: > >> On Jul 22 2021, Jisheng Zhang wrote: >> >>> I think we need to pin the stack before calling get_wchan(), could you please >>> try below patch? >> >> Thanks, this fixes the crash for me. >> >> Andreas. >> > > Thanks for testing. I will send out formal patch later > > Thanks > > . > Hi all: I tried to reproduced this crash in openSUSE code repo（ https://github.com/opensuse/kernel ）, but not reproduced successfully. From the patch of problem repair, the crash is due to task->stack is released before calling get_wchan, the task state of maybe TASK_DEAD. VMAP_STACK is used to detect kernel stack overflow, there is no connection between the two, it makes me a little confused.