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=-8.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 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 89175C3A589 for ; Mon, 19 Aug 2019 02:27:56 +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 5B74F2087E for ; Mon, 19 Aug 2019 02:27:56 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 5B74F2087E 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]:44138 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1hzXOl-0003V3-Bp for qemu-devel@archiver.kernel.org; Sun, 18 Aug 2019 22:27:55 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:42580) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1hzXO4-00034n-CT for qemu-devel@nongnu.org; Sun, 18 Aug 2019 22:27:13 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1hzXO3-0005ND-0u for qemu-devel@nongnu.org; Sun, 18 Aug 2019 22:27:12 -0400 Received: from mga17.intel.com ([192.55.52.151]:29387) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1hzXO2-0005Kz-NU for qemu-devel@nongnu.org; Sun, 18 Aug 2019 22:27:10 -0400 X-Amp-Result: UNKNOWN X-Amp-Original-Verdict: FILE UNKNOWN X-Amp-File-Uploaded: False Received: from orsmga004.jf.intel.com ([10.7.209.38]) by fmsmga107.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 18 Aug 2019 19:27:04 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.64,403,1559545200"; d="scan'208";a="329238100" Received: from richard.sh.intel.com (HELO localhost) ([10.239.159.54]) by orsmga004.jf.intel.com with ESMTP; 18 Aug 2019 19:27:02 -0700 Date: Mon, 19 Aug 2019 10:26:39 +0800 From: Wei Yang To: "Dr. David Alan Gilbert" Message-ID: <20190819022639.GA6368@richard> References: <20190712032704.7826-1-richardw.yang@linux.intel.com> <20190719175400.GJ3000@work-vm> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190719175400.GJ3000@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: 192.55.52.151 Subject: Re: [Qemu-devel] [PATCH] migration: check length directly to make sure the range is aligned 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: qemu-devel@nongnu.org, pbonzini@redhat.com, quintela@redhat.com, Wei Yang , rth@twiddle.net Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Fri, Jul 19, 2019 at 06:54:00PM +0100, Dr. David Alan Gilbert wrote: >* Wei Yang (richardw.yang@linux.intel.com) wrote: >> Since the start addr is already checked, to make sure the range is >> aligned, checking the length is enough. >> >> Signed-off-by: Wei Yang >> --- >> exec.c | 7 +++---- >> 1 file changed, 3 insertions(+), 4 deletions(-) >> >> diff --git a/exec.c b/exec.c >> index 50ea9c5aaa..8fa980baae 100644 >> --- a/exec.c >> +++ b/exec.c >> @@ -4067,10 +4067,9 @@ int ram_block_discard_range(RAMBlock *rb, uint64_t start, size_t length) >> >> if ((start + length) <= rb->used_length) { >> bool need_madvise, need_fallocate; >> - uint8_t *host_endaddr = host_startaddr + length; >> - 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; >David Gibson's balloon fix from February means that the balloon code >should now warn in it's case. > >rth: Want to pick this up? > >Reviewed-by: Dr. David Alan Gilbert > Hi, David Do you like this one? >> goto err; >> } >> >> -- >> 2.17.1 >> >-- >Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK -- Wei Yang Help you, Help me