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Date: Thu, 10 Dec 2015 13:04:48 +0100
Message-ID: <CAFLxGvy7z5zo1_9QfYZj1AMLN-+iVnErir_U7=5=y2bRFKHhNQ@mail.gmail.com>
Subject: Re: m(un)map kmalloc buffers to userspace
From: Richard Weinberger <richard.weinberger@gmail.com>
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Sender: owner-linux-mm@kvack.org
List-ID: <linux-mm.kvack.org>
To: Michal Hocko <mhocko@kernel.org>
Cc: Sebastian Frias <sebastian_frias@sigmadesigns.com>, Marc Gonzalez <marc_gonzalez@sigmadesigns.com>, linux-mm <linux-mm@kvack.org>, LKML <linux-kernel@vger.kernel.org>

On Thu, Dec 10, 2015 at 12:40 PM, Michal Hocko <mhocko@kernel.org> wrote:
> On Wed 09-12-15 16:35:53, Sebastian Frias wrote:
> [...]
>> We've seen that drivers/media/pci/zoran/zoran_driver.c for example seems to
>> be doing as us kmalloc+remap_pfn_range,
>
> This driver is broken - I will post a patch.
>
>> is there any guarantee (or at least an advised heuristic) to determine
>> if a driver is "current" (ie: uses the latest APIs and works)?
>
> OK, it seems I was overly optimistic when directing you to existing
> drivers. Sorry about that I wasn't aware you could find such a terrible
> code there. Please refer to Linux Device Drivers book which should give
> you a much better lead (e.g. http://www.makelinux.net/ldd3/chp-15-sect-2)

Also consider using UIO.

-- 
Thanks,
//richard

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