problem mapping physical address from /dev/mem

[Mulyadi Santosa]

Hi...

On Thu, Oct 6, 2011 at 02:34, Vaibhav Jain <vjoss197 at gmail.com> wrote:
> Hi,
>
> I am trying to run a program that scans memory from a given physical address
> using /dev/mem.
> It uses mmap to map physical address from /dev/mem. So to start with I used
> /proc/iomem to look up the
> physical memory mapping and found the address 00010000 to be the starting
> address for System ram. But whenever I
> provide this address to the program it throws an error of "Operation not
> permitted".

Probably this could also due to mmap NULL dereferencing protection (at
least that's how I name it :) )

By default, the lowest 65536 byte (10000 in hex) is protected from
mapping etc. It practically render such null dererefencing useless.


-- 
regards,

Mulyadi Santosa
Freelance Linux trainer and consultant

blog: the-hydra.blogspot.com
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