Re: [RFC PATCH] iommu: create direct_mapping after device attached

From	Joerg Roedel <joro@8bytes.org>
Newsgroups	linux.kernel
Subject	Re: [RFC PATCH] iommu: create direct_mapping after device attached
Date	2016-07-20 16:10 +0200
Message-ID	<rX0me-2ra-21@gated-at.bofh.it> (permalink)
References	<rWZ6N-1u8-1@gated-at.bofh.it>
Organization	linux.* mail to news gateway

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On Wed, Jul 20, 2016 at 08:49:21PM +0800, honghui.zhang@mediatek.com wrote:
> From: Honghui Zhang <honghui.zhang@mediatek.com>
> 
> For mtk iommu, the domain_finalize was called in device attatch, the mtk
> iommu iopgt ops was allocated and initialized in domain_finalize, the
> iommu_group_create_direct_mappings would call the map interface to
> implement the map. If it's earlier than device attach, there would be NULL
> dereference. Move the iommu_group_create_direct_mappings call after device
> attached.

No, this would open a race window where the device is attached, but
doesn't have its unity-mappings in place. You should re-organize the mtk
driver instead, so that it works in this order too.



	Joerg

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[RFC PATCH] iommu: create direct_mapping after device attached <honghui.zhang@mediatek.com> - 2016-07-20 14:50 +0200
  Re: [RFC PATCH] iommu: create direct_mapping after device attached Joerg Roedel <joro@8bytes.org> - 2016-07-20 16:10 +0200

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