From mboxrd@z Thu Jan  1 00:00:00 1970
From: getarunks@gmail.com (Arun Sudhilal)
Date: Mon, 3 Oct 2016 18:30:26 +0530
Subject: Error reading /dev/mem
In-Reply-To: <CAOK12Db6OzJagTgXMNcpJFOSnvOqNL8RqH=5GUVoi66wn=rC_g@mail.gmail.com>
References: <CAOK12Db6OzJagTgXMNcpJFOSnvOqNL8RqH=5GUVoi66wn=rC_g@mail.gmail.com>
Message-ID: <CABOM9ZraVOOcyc2XDvkfho52sr37F-xnizTYxB6QDxDw1hnhWw@mail.gmail.com>
To: kernelnewbies@lists.kernelnewbies.org
List-Id: kernelnewbies.lists.kernelnewbies.org

Hello Paddie,

On Wed, Sep 28, 2016 at 1:19 AM, Paddie O'Brien <paddieobrien@gmail.com> wrote:
> Hi,
>
> I have a system call that maps virtual to physical addresses. I have
> disabled CONFIG_STRICT_DEVMEM and am reading from /dev/mem to verify
> that the contents of the syscall-returned physical address match the
> contents of the virtual address. It works fine up to a point. Reading
> beyond byte 935321597 in /dev/mem throws a "bad address" error. Not
> sure it's relevant but I'm running on virtual box and specifying 1GB
> of RAM. Tried with 2GB of RAM and hit the same problem.
>
> Any idea why I can't read beyond the above point?

Can you send the output to cat /proc/iomem?

>
> Thanks.
>
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