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=-5.1 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A, 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 89EB0C433DB for ; Tue, 19 Jan 2021 16:09:34 +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 03D2621D7F for ; Tue, 19 Jan 2021 16:09:33 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 03D2621D7F 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]:46238 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1l1tZU-0002mE-So for qemu-devel@archiver.kernel.org; Tue, 19 Jan 2021 11:09:32 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:40164) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1l1tYF-0001tB-Um for qemu-devel@nongnu.org; Tue, 19 Jan 2021 11:08:16 -0500 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:30717) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.90_1) (envelope-from ) id 1l1tYD-0002hp-4H for qemu-devel@nongnu.org; Tue, 19 Jan 2021 11:08:15 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1611072490; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=PV37KtaIbe4rmwZfLkrLn1mEh0ceo2zqHiguZPrRouo=; b=e1+tMFkbIRZ/QeTd7uCmfYJcohEcYvm2H+vEHywcyluwYH4MQD/WNjUYlawUn7MA4CYLr8 XtVOPMOK86VoZCkNHLADHyk4piUtZGbubkKF/J9l1x1PfaqEkz89ZFApBRa/bd9o6Noxeu PCI6M6QHrmpRh/kkSoXiB1Pzyf+ppOY= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-179-mqOJvKAlPNWUWCLTZnzOYA-1; Tue, 19 Jan 2021 11:08:06 -0500 X-MC-Unique: mqOJvKAlPNWUWCLTZnzOYA-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 84C67806660; Tue, 19 Jan 2021 16:08:05 +0000 (UTC) Received: from [10.3.113.116] (ovpn-113-116.phx2.redhat.com [10.3.113.116]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 32BA460C5A; Tue, 19 Jan 2021 16:08:05 +0000 (UTC) Subject: Re: [PATCH v4 1/5] net: Clarify early exit condition To: Vladimir Sementsov-Ogievskiy , qemu-devel@nongnu.org References: <20210113221013.390592-1-eblake@redhat.com> <20210113221013.390592-2-eblake@redhat.com> <7e1edd6a-dbdf-3c4c-4dfa-c181418d09bd@virtuozzo.com> From: Eric Blake Organization: Red Hat, Inc. Message-ID: <689a713c-b190-aa77-106d-24ad8e3fc49e@redhat.com> Date: Tue, 19 Jan 2021 10:08:03 -0600 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.6.0 MIME-Version: 1.0 In-Reply-To: <7e1edd6a-dbdf-3c4c-4dfa-c181418d09bd@virtuozzo.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=eblake@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit Received-SPF: pass client-ip=216.205.24.124; envelope-from=eblake@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -29 X-Spam_score: -3.0 X-Spam_bar: --- X-Spam_report: (-3.0 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.195, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, NICE_REPLY_A=-0.001, RCVD_IN_DNSWL_LOW=-0.7, RCVD_IN_MSPIKE_H3=0.001, RCVD_IN_MSPIKE_WL=0.001, 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: Jason Wang , armbru@redhat.com Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On 1/13/21 10:54 PM, Vladimir Sementsov-Ogievskiy wrote: > 14.01.2021 01:10, Eric Blake wrote: >> On first glance, the loop in qmp_query_rx_filter() has early return >> paths that could leak any allocation of filter_list from a previous >> iteration.  But on closer inspection, it is obvious that all of the >> early exits are guarded by has_name, and that the bulk of the loop >> body can be executed at most once if the user is filtering by name, >> thus, any early exit coincides with an empty list.  Add asserts to >> make this obvious. > > A bit simpler (for me :) observation: > > But on closer inspection, it is obvious that all of the early exits are > guarded by has_name, and in case when has_name is true we leave the loop s/in case// > (by break) immediately after allocation and assigning filter_list for > the first time. Replacing my wording with this touched-up sentence is fine with me, if Markus would like to tweak the queued commit to incorporate it. -- Eric Blake, Principal Software Engineer Red Hat, Inc. +1-919-301-3226 Virtualization: qemu.org | libvirt.org