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=-8.6 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, NICE_REPLY_A,SIGNED_OFF_BY,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 DD9FDC4363D for ; Fri, 2 Oct 2020 06:20:27 +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 87B9D206DD for ; Fri, 2 Oct 2020 06:20:27 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=suse.com header.i=@suse.com header.b="duT1sp8u" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 87B9D206DD Authentication-Results: mail.kernel.org; dmarc=fail (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 list by lists.xenproject.org with outflank-mailman.1688.5114 (Exim 4.92) (envelope-from ) id 1kOEQO-0004XF-Cy; Fri, 02 Oct 2020 06:20:12 +0000 X-Outflank-Mailman: Message body and most headers restored to incoming version Received: by outflank-mailman (output) from mailman id 1688.5114; Fri, 02 Oct 2020 06:20:12 +0000 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" Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1kOEQO-0004X8-8M; Fri, 02 Oct 2020 06:20:12 +0000 Received: by outflank-mailman (input) for mailman id 1688; Fri, 02 Oct 2020 06:20:10 +0000 Received: from us1-rack-iad1.inumbo.com ([172.99.69.81]) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1kOEQM-0004X3-KO for xen-devel@lists.xenproject.org; Fri, 02 Oct 2020 06:20:10 +0000 Received: from mx2.suse.de (unknown [195.135.220.15]) by us1-rack-iad1.inumbo.com (Halon) with ESMTPS id 859395e9-6e23-4669-ad3c-a1a5b5311647; Fri, 02 Oct 2020 06:20:09 +0000 (UTC) Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id 06CC0AD2C; Fri, 2 Oct 2020 06:20:09 +0000 (UTC) Received: from us1-rack-iad1.inumbo.com ([172.99.69.81]) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1kOEQM-0004X3-KO for xen-devel@lists.xenproject.org; Fri, 02 Oct 2020 06:20:10 +0000 X-Inumbo-ID: 859395e9-6e23-4669-ad3c-a1a5b5311647 Received: from mx2.suse.de (unknown [195.135.220.15]) by us1-rack-iad1.inumbo.com (Halon) with ESMTPS id 859395e9-6e23-4669-ad3c-a1a5b5311647; Fri, 02 Oct 2020 06:20:09 +0000 (UTC) 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=1601619609; h=from:from:reply-to:subject:subject: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=ZbOzifHMrWmdV8hTzqw4L1Ltp2rraz8UHROP0ToP688=; b=duT1sp8uf2+cXRqnCIMZ6kFEhwyO/uvCWQRcjMSU6Ouf/FkYE2I/bjsZxp0nH6L73xAdRZ XOurxyEKX+2/N+p/LaAigeKrBBWOcolGRmG1wjZDgQ7sGoVw0va6mjGWpyfTY91tY5WrEb NMiPD8bA6Qq+hWrHoEcmLPaRI3Lc0lE= Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id 06CC0AD2C; Fri, 2 Oct 2020 06:20:09 +0000 (UTC) Subject: Re: [PATCH v3] tools/libs/stat: fix broken build To: =?UTF-8?B?SsO8cmdlbiBHcm/Dnw==?= Cc: Bertrand Marquis , "open list:X86" , Ian Jackson , Wei Liu References: <20200912130836.11024-1-jgross@suse.com> <5232FD74-9636-4EF4-81F8-2EF7EE21D326@arm.com> <87CA2B55-B372-458C-82CC-2423B8AC3EEE@arm.com> From: Jan Beulich Message-ID: Date: Fri, 2 Oct 2020 08:20:11 +0200 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:68.0) Gecko/20100101 Thunderbird/68.12.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit On 02.10.2020 06:50, Jürgen Groß wrote: > On 01.10.20 18:38, Bertrand Marquis wrote: >> Hi Juergen, >> >>> On 14 Sep 2020, at 11:58, Bertrand Marquis wrote: >>> >>> >>> >>>> On 12 Sep 2020, at 14:08, Juergen Gross wrote: >>>> >>>> Making getBridge() static triggered a build error with some gcc versions: >>>> >>>> error: 'strncpy' output may be truncated copying 15 bytes from a string of >>>> length 255 [-Werror=stringop-truncation] >>>> >>>> Fix that by using a buffer with 256 bytes instead. >>>> >>>> Fixes: 6d0ec053907794 ("tools: split libxenstat into new tools/libs/stat directory") >>>> Signed-off-by: Juergen Gross >>> Reviewed-by: Bertrand Marquis >> >> Sorry i have to come back on this one. >> >> I still see an error compiling with Yocto on this one: >> | inlined from 'xenstat_collect_networks' at xenstat_linux.c:306:2: >> | xenstat_linux.c:81:6: error: 'strncpy' output may be truncated copying 255 bytes from a string of length 255 [-Werror=stringop-truncation] >> | 81 | strncpy(result, de->d_name, resultLen); >> | | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ >> >> To solve it, I need to define devBridge[257] as devNoBrideg. > > IMHO this is a real compiler error. > > de->d_name is an array of 256 bytes, so doing strncpy() from that to > another array of 256 bytes with a length of 256 won't truncate anything. That's a matter of how you look at it, I think: If the original array doesn't hold a nul-terminated string, the destination array won't either, yet the common goal of strncpy() is to yield a properly nul- terminated string. IOW the warning may be since the standard even has a specific foot note to point out this possible pitfall. Jan