From patchwork Tue Apr 27 12:53:08 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jan Beulich X-Patchwork-Id: 12226691 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=-17.2 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, 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 213D5C433B4 for ; Tue, 27 Apr 2021 12:53:22 +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 C489C60E09 for ; Tue, 27 Apr 2021 12:53:21 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org C489C60E09 Authentication-Results: mail.kernel.org; dmarc=fail (p=quarantine dis=none) header.from=suse.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=xen-devel-bounces@lists.xenproject.org Received: from list by lists.xenproject.org with outflank-mailman.118424.224524 (Exim 4.92) (envelope-from ) id 1lbNDE-0002rf-3P; Tue, 27 Apr 2021 12:53:12 +0000 X-Outflank-Mailman: Message body and most headers restored to incoming version Received: by outflank-mailman (output) from mailman id 118424.224524; Tue, 27 Apr 2021 12:53:12 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1lbNDE-0002rY-0T; Tue, 27 Apr 2021 12:53:12 +0000 Received: by outflank-mailman (input) for mailman id 118424; Tue, 27 Apr 2021 12:53:10 +0000 Received: from us1-rack-iad1.inumbo.com ([172.99.69.81]) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1lbNDC-0002rS-6q for xen-devel@lists.xenproject.org; Tue, 27 Apr 2021 12:53:10 +0000 Received: from mx2.suse.de (unknown [195.135.220.15]) by us1-rack-iad1.inumbo.com (Halon) with ESMTPS id 2f82e92e-5cd4-4e22-a8aa-3c780d14dad7; Tue, 27 Apr 2021 12:53:09 +0000 (UTC) Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id BFE99B19D; Tue, 27 Apr 2021 12:53:08 +0000 (UTC) X-BeenThere: xen-devel@lists.xenproject.org List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xenproject.org Precedence: list Sender: "Xen-devel" X-Inumbo-ID: 2f82e92e-5cd4-4e22-a8aa-3c780d14dad7 X-Virus-Scanned: by amavisd-new at test-mx.suse.de DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1619527988; h=from:from:reply-to: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=5HO69LOYF/q+tMqUDzvDRQvMkLc5+o3wKO8eXoOtaQw=; b=ZcDjdrS+nrZcOBJjf3H1DMDCmoQXr+fLdQGL/aJRjASAKoL2G1J9w6sd678pAZe6s3LfLZ PkAdcOlKWqtOmN/zGwbo1Pd8eD8c2iHT+HYUBm+RYzPM+jA9c0gFM0Ck/PzpHNvcm2ZzQh QL2GNmZgX2Tvr45++JbfNeSjPkPkzYo= Subject: [PATCH 1/7] x86: correct comment about alternatives ordering From: Jan Beulich To: "xen-devel@lists.xenproject.org" Cc: Andrew Cooper , Wei Liu , =?utf-8?q?Roger_Pau_Monn=C3=A9?= References: <6d6da76c-ccc8-afa2-bd06-5ae132c354f2@suse.com> Message-ID: Date: Tue, 27 Apr 2021 14:53:08 +0200 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101 Thunderbird/78.10.0 MIME-Version: 1.0 In-Reply-To: <6d6da76c-ccc8-afa2-bd06-5ae132c354f2@suse.com> Content-Language: en-US Unlike Linux, Xen has never (so far) used alternatives patching for memcpy() or memset(), even less such utilizing multiple alternatives. Correct the Linux-inherited comment to match reality. Signed-off-by: Jan Beulich Acked-by: Andrew Cooper --- a/xen/arch/x86/alternative.c +++ b/xen/arch/x86/alternative.c @@ -194,8 +194,7 @@ static void init_or_livepatch _apply_alt /* * The scan order should be from start to end. A later scanned * alternative code can overwrite a previous scanned alternative code. - * Some kernel functions (e.g. memcpy, memset, etc) use this order to - * patch code. + * Some code (e.g. ALTERNATIVE_2()) relies on this order of patching. * * So be careful if you want to change the scan order to any other * order.