examining mmap()'d memory regions on linux

[Andrew Cagney]

Kevin Hilman wrote:
> 
> I have an app that reads/writes to an mmap()'d region.  The data
> is being read and written fine because it's getting to it's final
> location (in this case a hardware device).
> 
> However, if I try to examine (via 'x') these memory regions in gdb, I
> always get zeros.
> 
> Does gdb support mmap()'d regions?

Not a GDB problem.  GDB asks the kernel ``can I have memory at address X
with process P''.  If the kernel doesn't return it there is little GDB
can do :-)

As a work around, you may want to add a small function to your program
that dumps out the relevant data.  You can then call that from the gdb
command line.

	enjoy,
		Andrew