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=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_MUTT 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 007E6C46477 for ; Fri, 14 Jun 2019 07:18:31 +0000 (UTC) Received: from mail.linuxfoundation.org (mail.linuxfoundation.org [140.211.169.12]) (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 D36452133D for ; Fri, 14 Jun 2019 07:18:30 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org D36452133D Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=lst.de Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=iommu-bounces@lists.linux-foundation.org Received: from mail.linux-foundation.org (localhost [127.0.0.1]) by mail.linuxfoundation.org (Postfix) with ESMTP id A6BD9F18; Fri, 14 Jun 2019 07:18:30 +0000 (UTC) Received: from smtp1.linuxfoundation.org (smtp1.linux-foundation.org [172.17.192.35]) by mail.linuxfoundation.org (Postfix) with ESMTPS id 52088F18 for ; Fri, 14 Jun 2019 07:18:30 +0000 (UTC) X-Greylist: from auto-whitelisted by SQLgrey-1.7.6 Received: from newverein.lst.de (verein.lst.de [213.95.11.211]) by smtp1.linuxfoundation.org (Postfix) with ESMTPS id 54B1DE5 for ; Fri, 14 Jun 2019 07:18:29 +0000 (UTC) Received: by newverein.lst.de (Postfix, from userid 2407) id 7983A68B05; Fri, 14 Jun 2019 09:18:00 +0200 (CEST) Date: Fri, 14 Jun 2019 09:18:00 +0200 From: Christoph Hellwig To: Geert Uytterhoeven Subject: Re: [RFC PATCH v6 4/5] mmc: tmio: Use dma_max_mapping_size() instead of a workaround Message-ID: <20190614071800.GB8420@lst.de> References: <1560421215-10750-1-git-send-email-yoshihiro.shimoda.uh@renesas.com> <1560421215-10750-5-git-send-email-yoshihiro.shimoda.uh@renesas.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.17 (2007-11-01) Cc: Jens Axboe , Linux-Renesas , Ulf Hansson , Linux MMC List , Christoph Hellwig , linux-block@vger.kernel.org, Wolfram Sang , Linux IOMMU X-BeenThere: iommu@lists.linux-foundation.org X-Mailman-Version: 2.1.12 Precedence: list List-Id: Development issues for Linux IOMMU support List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: iommu-bounces@lists.linux-foundation.org Errors-To: iommu-bounces@lists.linux-foundation.org On Thu, Jun 13, 2019 at 10:35:44PM +0200, Geert Uytterhoeven wrote: > I'm always triggered by the use of min_t() and other casts: > mmc->max_blk_size and mmc->max_blk_count are both unsigned int. > dma_max_mapping_size() returns size_t, which can be 64-bit. > > 1) Can the multiplication overflow? > Probably not, as per commit 2a55c1eac7882232 ("mmc: renesas_sdhi: > prevent overflow for max_req_size"), but I thought I'd better ask. > 2) In theory, dma_max_mapping_size() can return a number that doesn't > fit in 32-bit, and will be truncated (to e.g. 0), leading to max_req_size > is zero? This really should use a min_t on size_t. Otherwise the patch looks fine: Reviewed-by: Christoph Hellwig _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu