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Date:   Tue, 29 Sep 2020 19:02:10 +0100
From:   Christoph Hellwig <hch@infradead.org>
To:     Jason Gunthorpe <jgg@nvidia.com>
Cc:     Leon Romanovsky <leon@kernel.org>,
        Doug Ledford <dledford@redhat.com>,
        Yishai Hadas <yishaih@nvidia.com>, linux-rdma@vger.kernel.org,
        Christoph Hellwig <hch@infradead.org>
Subject: Re: [PATCH rdma-next v2 1/4] IB/core: Improve ODP to use
 hmm_range_fault()
Message-ID: <20200929180210.GA5012@infradead.org>
References: <20200922082104.2148873-1-leon@kernel.org>
 <20200922082104.2148873-2-leon@kernel.org>
 <20200929175946.GA767138@nvidia.com>
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On Tue, Sep 29, 2020 at 02:59:46PM -0300, Jason Gunthorpe wrote:
> This leaves *dma_addr set to ib_dma_mapping_error, which means the
> next try to map it will fail the if (!dma_addr) and produce a
> corrupted dma address.
> 
> *dma_addr should be set to 0 here

Maybe the code should use DMA_MAPPING_ERROR as the sentinel for a
not mapped entry?