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=-2.3 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 F3D63C1975A for ; Wed, 25 Mar 2020 13:34:35 +0000 (UTC) Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) (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 CFE9320658 for ; Wed, 25 Mar 2020 13:34:35 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org CFE9320658 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=suse.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=xen-devel-bounces@lists.xenproject.org Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.89) (envelope-from ) id 1jH6Ah-00033v-98; Wed, 25 Mar 2020 13:34:15 +0000 Received: from us1-rack-iad1.inumbo.com ([172.99.69.81]) by lists.xenproject.org with esmtp (Exim 4.89) (envelope-from ) id 1jH6Af-00033q-QP for xen-devel@lists.xenproject.org; Wed, 25 Mar 2020 13:34:13 +0000 X-Inumbo-ID: 5070f9b6-6e9d-11ea-a6c1-bc764e2007e4 Received: from mx2.suse.de (unknown [195.135.220.15]) by us1-rack-iad1.inumbo.com (Halon) with ESMTPS id 5070f9b6-6e9d-11ea-a6c1-bc764e2007e4; Wed, 25 Mar 2020 13:34:13 +0000 (UTC) X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx2.suse.de (Postfix) with ESMTP id 164D1AC37; Wed, 25 Mar 2020 13:34:12 +0000 (UTC) To: Andrew Cooper References: <20200323101724.15655-1-andrew.cooper3@citrix.com> <20200323101724.15655-4-andrew.cooper3@citrix.com> From: Jan Beulich Message-ID: Date: Wed, 25 Mar 2020 14:34:07 +0100 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:68.0) Gecko/20100101 Thunderbird/68.6.0 MIME-Version: 1.0 In-Reply-To: <20200323101724.15655-4-andrew.cooper3@citrix.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Subject: Re: [Xen-devel] [PATCH 3/7] x86/ucode/intel: Remove gratuitous memory allocations from cpu_request_microcode() X-BeenThere: xen-devel@lists.xenproject.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Cc: Xen-devel , Wei Liu , =?UTF-8?Q?Roger_Pau_Monn=c3=a9?= Errors-To: xen-devel-bounces@lists.xenproject.org Sender: "Xen-devel" On 23.03.2020 11:17, Andrew Cooper wrote: > static struct microcode_patch *cpu_request_microcode(const void *buf, > size_t size) > { > - long offset = 0; > int error = 0; > - struct microcode_intel *mc, *saved = NULL; > + const struct microcode_intel *saved = NULL; > struct microcode_patch *patch = NULL; > > - while ( (offset = get_next_ucode_from_buffer(&mc, buf, size, offset)) > 0 ) > + while ( size ) > { > - error = microcode_sanity_check(mc); > - if ( error ) > + const struct microcode_intel *mc; > + unsigned int blob_size; > + > + if ( size < MC_HEADER_SIZE || /* Insufficient space for header? */ > + (mc = buf)->hdr.hdrver != 1 || /* Unrecognised header version? */ > + mc->hdr.ldrver != 1 || /* Unrecognised loader version? */ These two duplicate what microcode_sanity_check() does, plus the function issues a log message when either check fails. Since I think ... > + size < (blob_size = /* Insufficient space for patch? */ > + get_totalsize(&mc->hdr)) ) ... this wants to come after the two version checks, how about lifting the printk() here? The other user of microcode_sanity_check() is an ASSERT(), where it's rather less relevant to have such a printk(). Jan