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=-15.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,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 B3DF1C4361B for ; Wed, 16 Dec 2020 12:10:33 +0000 (UTC) Received: from silver.osuosl.org (smtp3.osuosl.org [140.211.166.136]) (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 1BEE623105 for ; Wed, 16 Dec 2020 12:10:32 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 1BEE623105 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=iommu-bounces@lists.linux-foundation.org Received: from localhost (localhost [127.0.0.1]) by silver.osuosl.org (Postfix) with ESMTP id 8A5A32010D; Wed, 16 Dec 2020 12:10:32 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from silver.osuosl.org ([127.0.0.1]) by localhost (.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id R5NFl6Lx1tdz; Wed, 16 Dec 2020 12:10:30 +0000 (UTC) Received: from lists.linuxfoundation.org (lf-lists.osuosl.org [140.211.9.56]) by silver.osuosl.org (Postfix) with ESMTP id DC5A120033; Wed, 16 Dec 2020 12:10:30 +0000 (UTC) Received: from lf-lists.osuosl.org (localhost [127.0.0.1]) by lists.linuxfoundation.org (Postfix) with ESMTP id CDE6AC088E; Wed, 16 Dec 2020 12:10:30 +0000 (UTC) Received: from fraxinus.osuosl.org (smtp4.osuosl.org [140.211.166.137]) by lists.linuxfoundation.org (Postfix) with ESMTP id 2D8B8C013B for ; Wed, 16 Dec 2020 12:10:30 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by fraxinus.osuosl.org (Postfix) with ESMTP id 1CCC085EC6 for ; Wed, 16 Dec 2020 12:10:30 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from fraxinus.osuosl.org ([127.0.0.1]) by localhost (.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id 2MP_BfJKS7s9 for ; Wed, 16 Dec 2020 12:10:27 +0000 (UTC) X-Greylist: domain auto-whitelisted by SQLgrey-1.7.6 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by fraxinus.osuosl.org (Postfix) with ESMTP id 5015F85742 for ; Wed, 16 Dec 2020 12:10:27 +0000 (UTC) Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id A86551FB; Wed, 16 Dec 2020 04:10:26 -0800 (PST) Received: from [10.57.34.90] (unknown [10.57.34.90]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 09D3C3F66E; Wed, 16 Dec 2020 04:10:23 -0800 (PST) Subject: Re: [PATCH v3 4/7] iommu: Switch gather->end to unsigned long long To: Yong Wu , Joerg Roedel , Will Deacon References: <20201216103607.23050-1-yong.wu@mediatek.com> <20201216103607.23050-5-yong.wu@mediatek.com> From: Robin Murphy Message-ID: <16a9565e-5b01-e1c2-0f4a-d06db7f3b093@arm.com> Date: Wed, 16 Dec 2020 12:10:22 +0000 User-Agent: Mozilla/5.0 (Windows NT 10.0; rv:78.0) Gecko/20100101 Thunderbird/78.5.1 MIME-Version: 1.0 In-Reply-To: <20201216103607.23050-5-yong.wu@mediatek.com> Content-Language: en-GB Cc: youlin.pei@mediatek.com, anan.sun@mediatek.com, Nicolas Boichat , srv_heupstream@mediatek.com, Tomasz Figa , linux-kernel@vger.kernel.org, Krzysztof Kozlowski , chao.hao@mediatek.com, iommu@lists.linux-foundation.org, linux-mediatek@lists.infradead.org, Matthias Brugger , Greg Kroah-Hartman , kernel-team@android.com, linux-arm-kernel@lists.infradead.org X-BeenThere: iommu@lists.linux-foundation.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: Development issues for Linux IOMMU support List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Errors-To: iommu-bounces@lists.linux-foundation.org Sender: "iommu" On 2020-12-16 10:36, Yong Wu wrote: > Currently gather->end is "unsigned long" which may be overflow in > arch32 in the corner case: 0xfff00000 + 0x100000(iova + size). > Although it doesn't affect the size(end - start), it affects the checking > "gather->end < end" This won't help the same situation at the top of a 64-bit address space, though, and now that we have TTBR1 support for AArch64 format that is definitely a thing. Better to just encode the end address as the actual end address, i.e. iova + size - 1. We don't lose anything other than the ability to encode zero-sized invalidations that don't make sense anyway. Robin. > Fixes: a7d20dc19d9e ("iommu: Introduce struct iommu_iotlb_gather for batching TLB flushes") > Signed-off-by: Yong Wu > --- > include/linux/iommu.h | 5 +++-- > 1 file changed, 3 insertions(+), 2 deletions(-) > > diff --git a/include/linux/iommu.h b/include/linux/iommu.h > index 794d4085edd3..6e907a95d981 100644 > --- a/include/linux/iommu.h > +++ b/include/linux/iommu.h > @@ -178,7 +178,7 @@ enum iommu_dev_features { > */ > struct iommu_iotlb_gather { > unsigned long start; > - unsigned long end; > + unsigned long long end; > size_t pgsize; > }; > > @@ -537,7 +537,8 @@ static inline void iommu_iotlb_gather_add_page(struct iommu_domain *domain, > struct iommu_iotlb_gather *gather, > unsigned long iova, size_t size) > { > - unsigned long start = iova, end = start + size; > + unsigned long start = iova; > + unsigned long long end = start + size; > > /* > * If the new page is disjoint from the current range or is mapped at > _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu