On Thu, Oct 6, 2011 at 11:28 AM, Mulyadi Santosa
[off-list ref]wrote:

Hi...

On Thu, Oct 6, 2011 at 02:34, Vaibhav Jain [off-list ref] wrote:

quoted

Hi,

I am trying to run a program that scans memory from a given physical

address

quoted

using /dev/mem.
It uses mmap to map physical address from /dev/mem. So to start with I

used

quoted

/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
training: mulyaditraining.blogspot.com

Hi,

I tried the same with other addresses (greater than 0x10000 ) also but it is
throwing the same error.
Is there a way to get over this ?

Thanks
Vaibhav Jain
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