From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-out.m-online.net (mail-out.m-online.net [212.18.0.9]) by sourceware.org (Postfix) with ESMTPS id 09C56385841F for ; Mon, 9 Aug 2021 07:48:42 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org 09C56385841F Authentication-Results: sourceware.org; dmarc=none (p=none dis=none) header.from=linux-m68k.org Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=nefkom.net Received: from frontend01.mail.m-online.net (unknown [192.168.8.182]) by mail-out.m-online.net (Postfix) with ESMTP id 4Gjp9h3SbYz1r9vG; Mon, 9 Aug 2021 09:48:40 +0200 (CEST) Received: from localhost (dynscan1.mnet-online.de [192.168.6.70]) by mail.m-online.net (Postfix) with ESMTP id 4Gjp9h2d01z1r6NX; Mon, 9 Aug 2021 09:48:40 +0200 (CEST) X-Virus-Scanned: amavisd-new at mnet-online.de Received: from mail.mnet-online.de ([192.168.8.182]) by localhost (dynscan1.mail.m-online.net [192.168.6.70]) (amavisd-new, port 10024) with ESMTP id 5kg8_ACuerUl; Mon, 9 Aug 2021 09:48:39 +0200 (CEST) X-Auth-Info: /to2TEiUafDteoOkm56Cvk/uvTCOdvVpiY9qUEE+9ehm2Kd+yfwzgut1AKzPodAU Received: from igel.home (ppp-46-244-162-191.dynamic.mnet-online.de [46.244.162.191]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.mnet-online.de (Postfix) with ESMTPSA; Mon, 9 Aug 2021 09:48:39 +0200 (CEST) Received: by igel.home (Postfix, from userid 1000) id 0DFCD2C0303; Mon, 9 Aug 2021 09:48:39 +0200 (CEST) From: Andreas Schwab To: "Dmitry V. Levin" Cc: Nikita Ermakov , libc-alpha@sourceware.org Subject: Re: [PATCH] elf: Use the 64-bit wide 'seen' variable References: <20210807142223.58295-1-sh1r4s3@mail.si-head.nl> <20210809004648.GB2038@altlinux.org> X-Yow: I joined scientology at a garage sale!! Date: Mon, 09 Aug 2021 09:48:38 +0200 In-Reply-To: <20210809004648.GB2038@altlinux.org> (Dmitry V. Levin's message of "Mon, 9 Aug 2021 03:46:48 +0300") Message-ID: <87lf5bgisp.fsf@igel.home> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/27.2 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain X-Spam-Status: No, score=-2.8 required=5.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS, KAM_DMARC_STATUS, RCVD_IN_DNSWL_LOW, RCVD_IN_MSPIKE_H3, RCVD_IN_MSPIKE_WL, SPF_HELO_NONE, SPF_PASS, TXREP autolearn=ham autolearn_force=no version=3.4.4 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on server2.sourceware.org X-BeenThere: libc-alpha@sourceware.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Libc-alpha mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 09 Aug 2021 07:48:43 -0000 On Aug 09 2021, Dmitry V. Levin wrote: > On Sat, Aug 07, 2021 at 05:22:23PM +0300, Nikita Ermakov via Libc-alpha wrote: >> The 32-bit 'seen' variable doesn't allow to check any auxiliary entry >> type with a value greater than 31 as it leads to wrapping and crumbling >> of the 'seen' variable. >> >> For example, if AT_UID (which is 11) would precede AT_L1D_CACHEGEOMETRY >> (which is 43), then uid would be overridden by an AT_L1D_CACHEGEOMETRY >> value. >> >> Using 64-bit wide 'seen' variable allows to handle such situations. > > I agree with the analysis, but I'm not sure uint64_t would be the most > appropriate type in this case. I'd suggest to consider using uintmax_t > instead. AT_* constants can be arbitrary so no type will fit. The right way to fix that is to check the range. Of course, this is only relevant for non-linux configurations. Andreas. -- Andreas Schwab, schwab@linux-m68k.org GPG Key fingerprint = 7578 EB47 D4E5 4D69 2510 2552 DF73 E780 A9DA AEC1 "And now for something completely different."