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=-8.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED 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 7A6BEC433E6 for ; Mon, 4 Jan 2021 10:56:43 +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 B83C6207BC for ; Mon, 4 Jan 2021 10:56:42 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org B83C6207BC Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=antioche.eu.org 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.61121.107277 (Exim 4.92) (envelope-from ) id 1kwNXD-0003sA-JX; Mon, 04 Jan 2021 10:56:23 +0000 X-Outflank-Mailman: Message body and most headers restored to incoming version Received: by outflank-mailman (output) from mailman id 61121.107277; Mon, 04 Jan 2021 10:56:23 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1kwNXD-0003s3-GO; Mon, 04 Jan 2021 10:56:23 +0000 Received: by outflank-mailman (input) for mailman id 61121; Mon, 04 Jan 2021 10:56:21 +0000 Received: from us1-rack-iad1.inumbo.com ([172.99.69.81]) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1kwNXB-0003ry-Lv for xen-devel@lists.xenproject.org; Mon, 04 Jan 2021 10:56:21 +0000 Received: from chassiron.antioche.eu.org (unknown [2001:41d0:fe9d:1101::1]) by us1-rack-iad1.inumbo.com (Halon) with ESMTPS id 21aafdf9-ff9e-45ec-a5ce-8704ae591ddd; Mon, 04 Jan 2021 10:56:20 +0000 (UTC) Received: from rochebonne.antioche.eu.org (rochebonne [IPv6:2001:41d0:fe9d:1100:221:70ff:fe0c:9885]) by chassiron.antioche.eu.org (8.15.2/8.15.2) with ESMTP id 104AuEBf025619; Mon, 4 Jan 2021 11:56:14 +0100 (MET) Received: by rochebonne.antioche.eu.org (Postfix, from userid 1210) id 482D4281D; Mon, 4 Jan 2021 11:56:14 +0100 (CET) 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: 21aafdf9-ff9e-45ec-a5ce-8704ae591ddd Date: Mon, 4 Jan 2021 11:56:14 +0100 From: Manuel Bouyer To: Roger Pau =?iso-8859-1?Q?Monn=E9?= Cc: xen-devel@lists.xenproject.org Subject: Re: [PATCH 19/24] errno may not be a gobal R/W variable, use a local variable instead (fix build on NetBSD) Message-ID: <20210104105614.GI2005@antioche.eu.org> References: <20201214163623.2127-1-bouyer@netbsd.org> <20201214163623.2127-20-bouyer@netbsd.org> <20201229143853.gikc7xqeqw6jjlvy@Air-de-Roger> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20201229143853.gikc7xqeqw6jjlvy@Air-de-Roger> X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.4.3 (chassiron.antioche.eu.org [IPv6:2001:41d0:fe9d:1101:0:0:0:1]); Mon, 04 Jan 2021 11:56:16 +0100 (MET) On Tue, Dec 29, 2020 at 03:38:53PM +0100, Roger Pau Monné wrote: > On Mon, Dec 14, 2020 at 05:36:18PM +0100, Manuel Bouyer wrote: > > --- > > tools/xenpaging/xenpaging.c | 5 +++-- > > 1 file changed, 3 insertions(+), 2 deletions(-) > > > > diff --git a/tools/xenpaging/xenpaging.c b/tools/xenpaging/xenpaging.c > > index 33098046c2..39c8c83b4b 100644 > > --- a/tools/xenpaging/xenpaging.c > > +++ b/tools/xenpaging/xenpaging.c > > @@ -180,10 +180,11 @@ static int xenpaging_get_tot_pages(struct xenpaging *paging) > > static void *init_page(void) > > { > > void *buffer; > > + int rc; > > > > /* Allocated page memory */ > > - errno = posix_memalign(&buffer, XC_PAGE_SIZE, XC_PAGE_SIZE); > > - if ( errno != 0 ) > > + rc = posix_memalign(&buffer, XC_PAGE_SIZE, XC_PAGE_SIZE); > > + if ( rc != 0 ) > > I think the point of setting errno here is because posix_memalign > doesn't set it and instead returns an error code. The caller of > init_page uses PERROR in order to print the error which his expected to > be in errno. I understand this. But on NetBSD, errno is: #define errno (*__errno()) (I think this is related to thread-safety). > > I don't think this is the only place in Xen code that errno is set, why > are the others fine but not this instance? probably this code is not used on NetBSD ? -- Manuel Bouyer NetBSD: 26 ans d'experience feront toujours la difference --