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=-2.2 required=3.0 tests=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 805DBCA9EAF for ; Mon, 28 Oct 2019 01:12:19 +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 537F4205C9 for ; Mon, 28 Oct 2019 01:12:19 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 537F4205C9 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.intel.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:50210 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1iOtZy-0002q7-AU for qemu-devel@archiver.kernel.org; Sun, 27 Oct 2019 21:12:18 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:44760) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1iOtYi-0002NC-UT for qemu-devel@nongnu.org; Sun, 27 Oct 2019 21:11:04 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1iOtYh-0000tI-LJ for qemu-devel@nongnu.org; Sun, 27 Oct 2019 21:11:00 -0400 Received: from mga04.intel.com ([192.55.52.120]:8972) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1iOtYg-0000oP-J2 for qemu-devel@nongnu.org; Sun, 27 Oct 2019 21:10:59 -0400 X-Amp-Result: UNKNOWN X-Amp-Original-Verdict: FILE UNKNOWN X-Amp-File-Uploaded: False Received: from fmsmga002.fm.intel.com ([10.253.24.26]) by fmsmga104.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 27 Oct 2019 18:10:50 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.68,238,1569308400"; d="scan'208";a="229534819" Received: from richard.sh.intel.com (HELO localhost) ([10.239.159.54]) by fmsmga002.fm.intel.com with ESMTP; 27 Oct 2019 18:10:49 -0700 Date: Mon, 28 Oct 2019 09:10:15 +0800 From: Wei Yang To: "Dr. David Alan Gilbert" Subject: Re: [Qemu-devel] [PATCH] migration: check length directly to make sure the range is aligned Message-ID: <20191028011015.GA3893@richard> References: <20190712032704.7826-1-richardw.yang@linux.intel.com> <20190719175400.GJ3000@work-vm> <0fd200f7-ad92-d753-23ca-8c89a27fd346@redhat.com> <20190719180651.GM3000@work-vm> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190719180651.GM3000@work-vm> User-Agent: Mutt/1.9.4 (2018-02-28) X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. X-Received-From: 192.55.52.120 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: Wei Yang Cc: Paolo Bonzini , rth@twiddle.net, Wei Yang , qemu-devel@nongnu.org, quintela@redhat.com Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Fri, Jul 19, 2019 at 07:06:51PM +0100, Dr. David Alan Gilbert wrote: >* Paolo Bonzini (pbonzini@redhat.com) wrote: >> On 19/07/19 19:54, Dr. David Alan Gilbert wrote: >> >> - if ((uintptr_t)host_endaddr & (rb->page_size - 1)) { >> >> - error_report("ram_block_discard_range: Unaligned end address: %p", >> >> - host_endaddr); >> >> + if (length & (rb->page_size - 1)) { >> >> + error_report("ram_block_discard_range: Unaligned length: %lx", >> >> + length); >> > Yes, I *think* this is safe, we'll need to watch out for any warnings; >> >> Do you mean compiler or QEMU warning? > >No, I mean lots of these error reports being printed out in some common >case. > Hi, Dave Haven't see you for a period of time :-) >Dave > > The patch is safe since there's an >> >> if ((uintptr_t)host_startaddr & (rb->page_size - 1)) { >> error_report("ram_block_discard_range: Unaligned start address: %p", >> host_startaddr); >> goto err; >> } >> >> just before this context. >> >> Paolo >-- >Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK -- Wei Yang Help you, Help me