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From:   Souptick Joarder <jrdr.linux@gmail.com>
Date:   Mon, 26 Aug 2019 01:32:09 +0530
Message-ID: <CAFqt6za5uUSKLMn0E25M1tYG853tpdE-kcoUYHdmby5s4d0JKg@mail.gmail.com>
Subject: Re: [PATCH] IB/mlx5: Convert to use vm_map_pages_zero()
To:     Jason Gunthorpe <jgg@ziepe.ca>
Cc:     leon@kernel.org, Doug Ledford <dledford@redhat.com>,
        linux-rdma@vger.kernel.org, linux-kernel@vger.kernel.org,
        Matthew Wilcox <willy@infradead.org>
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On Mon, Aug 26, 2019 at 1:13 AM Jason Gunthorpe <jgg@ziepe.ca> wrote:
>
> On Sun, Aug 25, 2019 at 11:37:27AM +0530, Souptick Joarder wrote:
> > First, length passed to mmap is checked explicitly against
> > PAGE_SIZE.
> >
> > Second, if vma->vm_pgoff is passed as non zero, it would return
> > error. It appears like driver is expecting vma->vm_pgoff to
> > be passed as 0 always.
>
> ? pg_off is not zero

Sorry, I mean, driver has a check against non zero to return error -EOPNOTSUPP
which means in true scenario driver is expecting vma->vm_pgoff should be passed
as 0.

-       if (get_index(vma->vm_pgoff) != MLX5_IB_CLOCK_INFO_V1)
-               return -EOPNOTSUPP;