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=-6.9 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED 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 033D4C04A6B for ; Tue, 7 May 2019 00:08:51 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id C5459206BF for ; Tue, 7 May 2019 00:08:50 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org C5459206BF 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 ([127.0.0.1]:35683 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1hNnf7-0000Bi-Nv for qemu-devel@archiver.kernel.org; Mon, 06 May 2019 20:08:49 -0400 Received: from eggs.gnu.org ([209.51.188.92]:59655) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1hNneJ-0008JF-J8 for qemu-devel@nongnu.org; Mon, 06 May 2019 20:08:00 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1hNneI-0002tl-J4 for qemu-devel@nongnu.org; Mon, 06 May 2019 20:07:59 -0400 Received: from mx1.redhat.com ([209.132.183.28]:52422) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1hNneE-0002r0-3M for qemu-devel@nongnu.org; Mon, 06 May 2019 20:07:57 -0400 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 4BAC13092676; Tue, 7 May 2019 00:07:51 +0000 (UTC) Received: from [10.72.12.47] (ovpn-12-47.pek2.redhat.com [10.72.12.47]) by smtp.corp.redhat.com (Postfix) with ESMTP id AF20661F21; Tue, 7 May 2019 00:07:49 +0000 (UTC) To: Lukas Straub , qemu-devel@nongnu.org References: <20190420191425.7d1dab82@luklap> <20190506123020.23d168a3@luklap> From: Jason Wang Message-ID: Date: Tue, 7 May 2019 08:07:47 +0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.6.1 MIME-Version: 1.0 In-Reply-To: <20190506123020.23d168a3@luklap> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.43]); Tue, 07 May 2019 00:07:51 +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 v2] net/colo-compare.c: Fix a crash in COLO Primary. X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: "Zhang, Chen" Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On 2019/5/6 =E4=B8=8B=E5=8D=886:32, Lukas Straub wrote: > On Sat, 20 Apr 2019 19:14:25 +0200 > Lukas Straub wrote: > >> From: Lukas Straub >> Because event_unhandled_count may be accessed concurrently, it needs >> to be protected by taking the lock. However the assert is outside the >> lock, probably causing it to read garbage and aborting Qemu >> erroneously. >> >> The Bug only happens when running Qemu in COLO mode. >> >> This Patch fixes the following bug: >> https://bugs.launchpad.net/qemu/+bug/1824622 >> >> Signed-off-by: Lukas Straub >> --- >> net/colo-compare.c | 3 +-- >> 1 file changed, 1 insertion(+), 2 deletions(-) >> >> diff --git a/net/colo-compare.c b/net/colo-compare.c >> index bf10526f05..fcb491121b 100644 >> --- a/net/colo-compare.c >> +++ b/net/colo-compare.c >> @@ -813,9 +813,8 @@ static void colo_compare_handle_event(void >> *opaque) break; >> } >> >> - assert(event_unhandled_count > 0); >> - >> qemu_mutex_lock(&event_mtx); >> + assert(event_unhandled_count > 0); >> event_unhandled_count--; >> qemu_cond_broadcast(&event_complete_cond); >> qemu_mutex_unlock(&event_mtx); > Ping. > > Regards, > Lukas Straub Applied. Thanks >