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Date:   Thu, 23 May 2019 16:10:38 -0300
From:   Jason Gunthorpe <jgg@ziepe.ca>
To:     Jerome Glisse <jglisse@redhat.com>
Cc:     linux-kernel@vger.kernel.org, linux-rdma@vger.kernel.org,
        Leon Romanovsky <leonro@mellanox.com>,
        Doug Ledford <dledford@redhat.com>,
        Artemy Kovalyov <artemyko@mellanox.com>,
        Moni Shoua <monis@mellanox.com>,
        Mike Marciniszyn <mike.marciniszyn@intel.com>,
        Kaike Wan <kaike.wan@intel.com>,
        Dennis Dalessandro <dennis.dalessandro@intel.com>
Subject: Re: [PATCH v4 0/1] Use HMM for ODP v4
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On Thu, May 23, 2019 at 02:24:58PM -0400, Jerome Glisse wrote:
> I can not take mmap_sem in range_register, the READ_ONCE is fine and
> they are no race as we do take a reference on the hmm struct thus

Of course there are use after free races with a READ_ONCE scheme, I
shouldn't have to explain this.

If you cannot take the read mmap sem (why not?), then please use my
version and push the update to the driver through -mm..

Jason