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=-8.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_2 autolearn=unavailable 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 4FD0BC433E0 for ; Thu, 11 Jun 2020 23:55:57 +0000 (UTC) Received: from whitealder.osuosl.org (smtp1.osuosl.org [140.211.166.138]) (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 11EF720731 for ; Thu, 11 Jun 2020 23:55:56 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 11EF720731 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.intel.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 whitealder.osuosl.org (Postfix) with ESMTP id B140D88578; Thu, 11 Jun 2020 23:55:56 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from whitealder.osuosl.org ([127.0.0.1]) by localhost (.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id erRStojBlWcM; Thu, 11 Jun 2020 23:55:53 +0000 (UTC) Received: from lists.linuxfoundation.org (lf-lists.osuosl.org [140.211.9.56]) by whitealder.osuosl.org (Postfix) with ESMTP id AEB3B885FA; Thu, 11 Jun 2020 23:55:53 +0000 (UTC) Received: from lf-lists.osuosl.org (localhost [127.0.0.1]) by lists.linuxfoundation.org (Postfix) with ESMTP id 92676C0865; Thu, 11 Jun 2020 23:55:53 +0000 (UTC) Received: from fraxinus.osuosl.org (smtp4.osuosl.org [140.211.166.137]) by lists.linuxfoundation.org (Postfix) with ESMTP id 4BEA4C016F for ; Thu, 11 Jun 2020 23:55:52 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by fraxinus.osuosl.org (Postfix) with ESMTP id 3A6E2874FE for ; Thu, 11 Jun 2020 23:55:52 +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 P5XHmcP2GMSv for ; Thu, 11 Jun 2020 23:55:51 +0000 (UTC) X-Greylist: domain auto-whitelisted by SQLgrey-1.7.6 Received: from mga11.intel.com (mga11.intel.com [192.55.52.93]) by fraxinus.osuosl.org (Postfix) with ESMTPS id 93B1A874FB for ; Thu, 11 Jun 2020 23:55:51 +0000 (UTC) IronPort-SDR: 05mqeU6Khn7b6aPKrZJay8X0TCH2E3H/h2po4+g5I7fCdVMW85nDEqvTS/SB0Wg9h321gd1X3a TrUYF7IgR/dQ== X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga002.fm.intel.com ([10.253.24.26]) by fmsmga102.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 11 Jun 2020 16:55:51 -0700 IronPort-SDR: 4x4zF9SvzKmm9dyWY4ue1fzA7Z0jpOO7A56jcV2UPWtsr3bi7KKjOgihk+gEqKQhpjKD9m+RxM GgF6RmS9MIng== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.73,501,1583222400"; d="scan'208";a="307124319" Received: from jacob-builder.jf.intel.com (HELO jacob-builder) ([10.7.199.155]) by fmsmga002.fm.intel.com with ESMTP; 11 Jun 2020 16:55:50 -0700 Date: Thu, 11 Jun 2020 17:02:15 -0700 From: Jacob Pan To: Alex Williamson Subject: Re: [PATCH v2 2/3] iommu/uapi: Add argsz for user filled data Message-ID: <20200611170215.7005042e@jacob-builder> In-Reply-To: <20200611104936.5129e99e@x1.home> References: <1591848735-12447-1-git-send-email-jacob.jun.pan@linux.intel.com> <1591848735-12447-3-git-send-email-jacob.jun.pan@linux.intel.com> <20200611104936.5129e99e@x1.home> Organization: OTC X-Mailer: Claws Mail 3.13.2 (GTK+ 2.24.30; x86_64-pc-linux-gnu) MIME-Version: 1.0 Cc: "Tian, Kevin" , Raj Ashok , Jonathan Corbet , Jean-Philippe Brucker , LKML , Christoph Hellwig , iommu@lists.linux-foundation.org, David Woodhouse 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-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: iommu-bounces@lists.linux-foundation.org Sender: "iommu" On Thu, 11 Jun 2020 10:49:36 -0600 Alex Williamson wrote: > On Wed, 10 Jun 2020 21:12:14 -0700 > Jacob Pan wrote: > > > As IOMMU UAPI gets extended, user data size may increase. To support > > backward compatibiliy, this patch introduces a size field to each > > UAPI data structures. It is *always* the responsibility for the > > user to fill in the correct size. > > Though at the same time, argsz is user provided data which we don't > trust. The argsz field allows the user to indicate how much data > they're providing, it's still the kernel's responsibility to validate > whether it's correct and sufficient for the requested operation. > Thanks, > Yes, will add this clarification. Thanks, Jacob > Alex > > > Specific scenarios for user data handling are documented in: > > Documentation/userspace-api/iommu.rst > > > > Signed-off-by: Liu Yi L > > Signed-off-by: Jacob Pan > > --- > > include/uapi/linux/iommu.h | 6 ++++++ > > 1 file changed, 6 insertions(+) > > > > diff --git a/include/uapi/linux/iommu.h b/include/uapi/linux/iommu.h > > index e907b7091a46..303f148a5cd7 100644 > > --- a/include/uapi/linux/iommu.h > > +++ b/include/uapi/linux/iommu.h > > @@ -135,6 +135,7 @@ enum iommu_page_response_code { > > > > /** > > * struct iommu_page_response - Generic page response information > > + * @argsz: User filled size of this data > > * @version: API version of this structure > > * @flags: encodes whether the corresponding fields are valid > > * (IOMMU_FAULT_PAGE_RESPONSE_* values) > > @@ -143,6 +144,7 @@ enum iommu_page_response_code { > > * @code: response code from &enum iommu_page_response_code > > */ > > struct iommu_page_response { > > + __u32 argsz; > > #define IOMMU_PAGE_RESP_VERSION_1 1 > > __u32 version; > > #define IOMMU_PAGE_RESP_PASID_VALID (1 << 0) > > @@ -218,6 +220,7 @@ struct iommu_inv_pasid_info { > > /** > > * struct iommu_cache_invalidate_info - First level/stage > > invalidation > > * information > > + * @argsz: User filled size of this data > > * @version: API version of this structure > > * @cache: bitfield that allows to select which caches to > > invalidate > > * @granularity: defines the lowest granularity used for the > > invalidation: @@ -246,6 +249,7 @@ struct iommu_inv_pasid_info { > > * must support the used granularity. > > */ > > struct iommu_cache_invalidate_info { > > + __u32 argsz; > > #define IOMMU_CACHE_INVALIDATE_INFO_VERSION_1 1 > > __u32 version; > > /* IOMMU paging structure cache */ > > @@ -292,6 +296,7 @@ struct iommu_gpasid_bind_data_vtd { > > > > /** > > * struct iommu_gpasid_bind_data - Information about device and > > guest PASID binding > > + * @argsz: User filled size of this data > > * @version: Version of this data structure > > * @format: PASID table entry format > > * @flags: Additional information on guest bind request > > @@ -309,6 +314,7 @@ struct iommu_gpasid_bind_data_vtd { > > * PASID to host PASID based on this bind data. > > */ > > struct iommu_gpasid_bind_data { > > + __u32 argsz; > > #define IOMMU_GPASID_BIND_VERSION_1 1 > > __u32 version; > > #define IOMMU_PASID_FORMAT_INTEL_VTD 1 > [Jacob Pan] _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu