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=-5.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=no 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 09CC7C433ED for ; Mon, 17 May 2021 07:11:18 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 7AA6D60E09 for ; Mon, 17 May 2021 07:11:17 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 7AA6D60E09 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=huawei.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:40832 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1liXPI-0007hj-Jl for qemu-devel@archiver.kernel.org; Mon, 17 May 2021 03:11:16 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:35806) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1liXBN-0006QV-MY for qemu-devel@nongnu.org; Mon, 17 May 2021 02:56:54 -0400 Received: from szxga06-in.huawei.com ([45.249.212.32]:2560) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1liXBI-0007yY-6A for qemu-devel@nongnu.org; Mon, 17 May 2021 02:56:52 -0400 Received: from dggems701-chm.china.huawei.com (unknown [172.30.72.58]) by szxga06-in.huawei.com (SkyGuard) with ESMTP id 4Fk8xt2S88zmWgS; Mon, 17 May 2021 14:54:26 +0800 (CST) Received: from dggpeml500016.china.huawei.com (7.185.36.70) by dggems701-chm.china.huawei.com (10.3.19.178) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2176.2; Mon, 17 May 2021 14:56:40 +0800 Received: from [10.174.148.223] (10.174.148.223) by dggpeml500016.china.huawei.com (7.185.36.70) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2176.2; Mon, 17 May 2021 14:56:40 +0800 From: "Longpeng (Mike, Cloud Infrastructure Service Product Dept.)" To: , , Subject: A bug of Monitor Chardev ? Message-ID: Date: Mon, 17 May 2021 14:56:39 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 Content-Type: text/plain; charset="gbk" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.174.148.223] X-ClientProxiedBy: dggems704-chm.china.huawei.com (10.3.19.181) To dggpeml500016.china.huawei.com (7.185.36.70) X-CFilter-Loop: Reflected Received-SPF: pass client-ip=45.249.212.32; envelope-from=longpeng2@huawei.com; helo=szxga06-in.huawei.com X-Spam_score_int: -41 X-Spam_score: -4.2 X-Spam_bar: ---- X-Spam_report: (-4.2 / 5.0 requ) BAYES_00=-1.9, RCVD_IN_DNSWL_MED=-2.3, RCVD_IN_MSPIKE_H3=-0.01, RCVD_IN_MSPIKE_WL=-0.01, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: chenjiashang@huawei.com, "Gonglei \(Arei\)" , qemu-devel@nongnu.org Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" We find a race during QEMU starting, which would case the QEMU process coredump.
| | [1] create MON chardev | qemu_create_early_backends | chardev_init_func | | [2] create MON iothread | qemu_create_late_backends | mon_init_func | aio_bh_schedule-----------------------> monitor_qmp_setup_handlers_bh [3] enter main loog | tcp_chr_update_read_handler (* A client come in, e.g. Libvirt *) | update_ioc_handlers tcp_chr_new_client | update_ioc_handlers | | [4] create new hup_source | s->hup_source = *PTR1* | g_source_attach(s->hup_source)| | [5] remove_hup_source(*PTR1*) | (create new hup_source) | s->hup_source = *PTR2* [6] g_source_attach_unlocked | *PTR1* is freed by [5] | Do you have any suggestion to fix this bug ? Thanks!