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=-2.1 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, 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 5CC0BC433DF for ; Thu, 4 Jun 2020 21:56:23 +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 25E112067B for ; Thu, 4 Jun 2020 21:56:23 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="ddG2CJL8" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 25E112067B 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]:46350 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jgxqY-0002Q8-Ed for qemu-devel@archiver.kernel.org; Thu, 04 Jun 2020 17:56:22 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:36070) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1jgxpX-0001Mc-Je for qemu-devel@nongnu.org; Thu, 04 Jun 2020 17:55:21 -0400 Received: from us-smtp-1.mimecast.com ([207.211.31.81]:26739 helo=us-smtp-delivery-1.mimecast.com) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.90_1) (envelope-from ) id 1jgxpU-0000ta-13 for qemu-devel@nongnu.org; Thu, 04 Jun 2020 17:55:18 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1591307714; 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=sdXXWjoY5/iTvsd9MYNX1eirF9T4vt02eSPP3jxJc/w=; b=ddG2CJL8+7OOwRLF2nMe9lSwYFOQ4XaSaCJSWdFFk2U4t2bWSUOr2f+qEamRy5yuq5YdFb VbS37azbwhcJA1Y/fEh87fIbP6lmDoJoOdP+bP3Lj+ZQCN0dLTdwvDm+gmV3pDLeOwF1mP Bgw3dnSSVmjnGEa5CfOZzQCg6jfBRDY= 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-207-JIPMmbwbPzWkpj4HQTSATw-1; Thu, 04 Jun 2020 17:55:07 -0400 X-MC-Unique: JIPMmbwbPzWkpj4HQTSATw-1 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 637E2835B40; Thu, 4 Jun 2020 21:55:06 +0000 (UTC) Received: from [10.3.113.22] (ovpn-113-22.phx2.redhat.com [10.3.113.22]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 6056810013D7; Thu, 4 Jun 2020 21:55:02 +0000 (UTC) Subject: Re: [PATCH v4] osdep: Make MIN/MAX evaluate arguments only once From: Eric Blake To: qemu-devel@nongnu.org References: <20200604215236.2798244-1-eblake@redhat.com> Organization: Red Hat, Inc. Message-ID: <7233fccd-aaff-d705-0746-99648c61a15c@redhat.com> Date: Thu, 4 Jun 2020 16:55:01 -0500 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.8.0 MIME-Version: 1.0 In-Reply-To: <20200604215236.2798244-1-eblake@redhat.com> Content-Language: en-US X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Received-SPF: pass client-ip=207.211.31.81; envelope-from=eblake@redhat.com; helo=us-smtp-delivery-1.mimecast.com X-detected-operating-system: by eggs.gnu.org: First seen = 2020/06/04 01:31:23 X-ACL-Warn: Detected OS = Linux 2.2.x-3.x [generic] [fuzzy] X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H4=0.001, RCVD_IN_MSPIKE_WL=0.001, 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: Kevin Wolf , "open list:Block layer core" , quintela@redhat.com, crosthwaite.peter@gmail.com, dgilbert@redhat.com, f4bug@amsat.org, kraxel@redhat.com, dirty.ice.hu@gmail.com, pbonzini@redhat.com, Max Reitz , rth@twiddle.net Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On 6/4/20 4:52 PM, Eric Blake wrote: > I'm not aware of any immediate bugs in qemu where a second runtime > evalution of the arguments to MIN() or MAX() causes a problem, but evaluation > proactively preventing such abuse is easier than falling prey to an > unintended case down the road. At any rate, here's the conversation > that sparked the current patch: > https://lists.gnu.org/archive/html/qemu-devel/2018-12/msg05718.html > -- Eric Blake, Principal Software Engineer Red Hat, Inc. +1-919-301-3226 Virtualization: qemu.org | libvirt.org