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=-5.2 required=3.0 tests=FROM_EXCESS_BASE64, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY,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 8FE8BC3A589 for ; Tue, 20 Aug 2019 09:59:19 +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 64E5B22CF4 for ; Tue, 20 Aug 2019 09:59:19 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 64E5B22CF4 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:35446 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1i00v8-0000W6-KM for qemu-devel@archiver.kernel.org; Tue, 20 Aug 2019 05:59:18 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:40421) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1i00u7-0008UZ-5Y for qemu-devel@nongnu.org; Tue, 20 Aug 2019 05:58:16 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1i00u5-0000iB-Dx for qemu-devel@nongnu.org; Tue, 20 Aug 2019 05:58:14 -0400 Received: from mx1.redhat.com ([209.132.183.28]:56930) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1i00u5-0000gi-5H for qemu-devel@nongnu.org; Tue, 20 Aug 2019 05:58:13 -0400 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 93507106BB22; Tue, 20 Aug 2019 09:58:10 +0000 (UTC) Received: from redhat.com (ovpn-112-61.ams2.redhat.com [10.36.112.61]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 381847E39; Tue, 20 Aug 2019 09:58:03 +0000 (UTC) Date: Tue, 20 Aug 2019 10:58:00 +0100 From: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= To: Andrey Shinkevich Message-ID: <20190820095800.GF23352@redhat.com> References: <1565625509-404969-1-git-send-email-andrey.shinkevich@virtuozzo.com> <1565625509-404969-3-git-send-email-andrey.shinkevich@virtuozzo.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <1565625509-404969-3-git-send-email-andrey.shinkevich@virtuozzo.com> User-Agent: Mutt/1.12.0 (2019-05-25) X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.6.2 (mx1.redhat.com [10.5.110.64]); Tue, 20 Aug 2019 09:58:11 +0000 (UTC) Content-Transfer-Encoding: quoted-printable X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 209.132.183.28 Subject: Re: [Qemu-devel] [PATCH v4 2/2] char-socket: Lock tcp_chr_disconnect() and socket_reconnect_timeout() 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: , Reply-To: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= Cc: vsementsov@virtuozzo.com, berto@igalia.com, qemu-devel@nongnu.org, marcandre.lureau@redhat.com, pbonzini@redhat.com, den@openvz.org Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Mon, Aug 12, 2019 at 06:58:29PM +0300, Andrey Shinkevich wrote: > From: Alberto Garcia >=20 > There's a race condition in which the tcp_chr_read() ioc handler can > close a connection that is being written to from another thread. >=20 > Running iotest 136 in a loop triggers this problem and crashes QEMU. >=20 > (gdb) bt > #0 0x00005558b842902d in object_get_class (obj=3D0x0) at qom/object.c= :860 > #1 0x00005558b84f92db in qio_channel_writev_full (ioc=3D0x0, iov=3D0x= 7ffc355decf0, niov=3D1, fds=3D0x0, nfds=3D0, errp=3D0x0) at io/channel.c:= 76 > #2 0x00005558b84e0e9e in io_channel_send_full (ioc=3D0x0, buf=3D0x555= 8baf5beb0, len=3D138, fds=3D0x0, nfds=3D0) at chardev/char-io.c:123 > #3 0x00005558b84e4a69 in tcp_chr_write (chr=3D0x5558ba460380, buf=3D0= x5558baf5beb0 "...", len=3D138) at chardev/char-socket.c:135 > #4 0x00005558b84dca55 in qemu_chr_write_buffer (s=3D0x5558ba460380, b= uf=3D0x5558baf5beb0 "...", len=3D138, offset=3D0x7ffc355dedd0, write_all=3D= false) at chardev/char.c:112 > #5 0x00005558b84dcbc2 in qemu_chr_write (s=3D0x5558ba460380, buf=3D0x= 5558baf5beb0 "...", len=3D138, write_all=3Dfalse) at chardev/char.c:147 > #6 0x00005558b84dfb26 in qemu_chr_fe_write (be=3D0x5558ba476610, buf=3D= 0x5558baf5beb0 "...", len=3D138) at chardev/char-fe.c:42 > #7 0x00005558b8088c86 in monitor_flush_locked (mon=3D0x5558ba476610) = at monitor.c:406 > #8 0x00005558b8088e8c in monitor_puts (mon=3D0x5558ba476610, str=3D0x= 5558ba921e49 "") at monitor.c:449 > #9 0x00005558b8089178 in qmp_send_response (mon=3D0x5558ba476610, rsp= =3D0x5558bb161600) at monitor.c:498 > #10 0x00005558b808920c in monitor_qapi_event_emit (event=3DQAPI_EVENT_= SHUTDOWN, qdict=3D0x5558bb161600) at monitor.c:526 > #11 0x00005558b8089307 in monitor_qapi_event_queue_no_reenter (event=3D= QAPI_EVENT_SHUTDOWN, qdict=3D0x5558bb161600) at monitor.c:551 > #12 0x00005558b80896c0 in qapi_event_emit (event=3DQAPI_EVENT_SHUTDOWN= , qdict=3D0x5558bb161600) at monitor.c:626 > #13 0x00005558b855f23b in qapi_event_send_shutdown (guest=3Dfalse, rea= son=3DSHUTDOWN_CAUSE_HOST_QMP_QUIT) at qapi/qapi-events-run-state.c:43 > #14 0x00005558b81911ef in qemu_system_shutdown (cause=3DSHUTDOWN_CAUSE= _HOST_QMP_QUIT) at vl.c:1837 > #15 0x00005558b8191308 in main_loop_should_exit () at vl.c:1885 > #16 0x00005558b819140d in main_loop () at vl.c:1924 > #17 0x00005558b8198c84 in main (argc=3D18, argv=3D0x7ffc355df3f8, envp= =3D0x7ffc355df490) at vl.c:4665 >=20 > This patch adds a lock to protect tcp_chr_disconnect() and > socket_reconnect_timeout() >=20 > Signed-off-by: Alberto Garcia > Signed-off-by: Andrey Shinkevich Reviewed-by: Daniel P. Berrang=C3=A9 Regards, Daniel --=20 |: https://berrange.com -o- https://www.flickr.com/photos/dberran= ge :| |: https://libvirt.org -o- https://fstop138.berrange.c= om :| |: https://entangle-photo.org -o- https://www.instagram.com/dberran= ge :|