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=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_2 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 60FE1C28CBC for ; Wed, 6 May 2020 17:55:05 +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 3AFE4206D5 for ; Wed, 6 May 2020 17:55:05 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 3AFE4206D5 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=kaod.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:34108 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jWOG8-00019S-C0 for qemu-devel@archiver.kernel.org; Wed, 06 May 2020 13:55:04 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:51320) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1jWOFU-0000Py-Ei for qemu-devel@nongnu.org; Wed, 06 May 2020 13:54:24 -0400 Received: from 5.mo179.mail-out.ovh.net ([46.105.43.140]:33674) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1jWOFT-0007mk-CK for qemu-devel@nongnu.org; Wed, 06 May 2020 13:54:24 -0400 Received: from player718.ha.ovh.net (unknown [10.108.42.215]) by mo179.mail-out.ovh.net (Postfix) with ESMTP id 5D9B4165077 for ; Wed, 6 May 2020 19:54:19 +0200 (CEST) Received: from kaod.org (lns-bzn-46-82-253-208-248.adsl.proxad.net [82.253.208.248]) (Authenticated sender: groug@kaod.org) by player718.ha.ovh.net (Postfix) with ESMTPSA id A0E64120156A0; Wed, 6 May 2020 17:54:17 +0000 (UTC) Date: Wed, 6 May 2020 19:54:15 +0200 From: Greg Kurz To: Christian Schoenebeck Subject: Re: [PATCH] 9pfs: Fix potential deadlock of QEMU mainloop Message-ID: <20200506195415.4cc48810@bahia.lan> In-Reply-To: <3204505.kZXhZKLjgj@silver> References: <158826201391.1344781.9403916162733181811.stgit@bahia.lan> <4216293.sUgoX00Q1d@silver> <3204505.kZXhZKLjgj@silver> X-Mailer: Claws Mail 3.17.4 (GTK+ 2.24.32; x86_64-redhat-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Ovh-Tracer-Id: 17999198861922113856 X-VR-SPAMSTATE: OK X-VR-SPAMSCORE: 0 X-VR-SPAMCAUSE: gggruggvucftvghtrhhoucdtuddrgeduhedrjeekgdduudehucetufdoteggodetrfdotffvucfrrhhofhhilhgvmecuqfggjfdpvefjgfevmfevgfenuceurghilhhouhhtmecuhedttdenucenucfjughrpeffhffvuffkjghfofggtgfgsehtjeertdertddvnecuhfhrohhmpefirhgvghcumfhurhiiuceoghhrohhugheskhgrohgurdhorhhgqeenucggtffrrghtthgvrhhnpeehkefhtdehgeehheejledufeekhfdvleefvdeihefhkefhudffhfeuuedvffdthfenucfkpheptddrtddrtddrtddpkedvrddvheefrddvtdekrddvgeeknecuvehluhhsthgvrhfuihiivgeptdenucfrrghrrghmpehmohguvgepshhmthhpqdhouhhtpdhhvghlohepphhlrgihvghrjedukedrhhgrrdhovhhhrdhnvghtpdhinhgvtheptddrtddrtddrtddpmhgrihhlfhhrohhmpehgrhhouhhgsehkrghougdrohhrghdprhgtphhtthhopehqvghmuhdquggvvhgvlhesnhhonhhgnhhurdhorhhg Received-SPF: pass client-ip=46.105.43.140; envelope-from=groug@kaod.org; helo=5.mo179.mail-out.ovh.net X-detected-operating-system: by eggs.gnu.org: First seen = 2020/05/06 13:54:19 X-ACL-Warn: Detected OS = Linux 3.11 and newer X-Spam_score_int: -18 X-Spam_score: -1.9 X-Spam_bar: - X-Spam_report: (-1.9 / 5.0 requ) BAYES_00=-1.9, RCVD_IN_DNSWL_NONE=-0.0001, SPF_PASS=-0.001, URIBL_BLOCKED=0.001 autolearn=_AUTOLEARN 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: qemu-devel@nongnu.org Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Wed, 06 May 2020 15:36:16 +0200 Christian Schoenebeck wrote: > On Mittwoch, 6. Mai 2020 15:05:23 CEST Christian Schoenebeck wrote: > > > diff --git a/hw/9pfs/9p.c b/hw/9pfs/9p.c > > > index 9e046f7acb51..ac84ae804496 100644 > > > --- a/hw/9pfs/9p.c > > > +++ b/hw/9pfs/9p.c > > > @@ -2170,7 +2170,7 @@ static int coroutine_fn > > > v9fs_do_readdir_with_stat(V9fsPDU *pdu, int32_t count = 0; > > > > > > struct stat stbuf; > > > off_t saved_dir_pos; > > > > > > - struct dirent *dent; > > > + struct dirent dent; > > One more: since this dirent structure is now on the stack, it should better be > initialized for safety reasons. > I don't think so, for two reasons: - I can't think of an initializer that would make sense for a dirent - if a future change introduces a branch where dent could be used uninitialized, I'd rather give a chance to the compiler to bark > Best regards, > Christian Schoenebeck > >