Shared mapping

[riya khanna]

Hi,

Is there a way, w.r.t memory contents, to make a process B see what
process A sees through shared memory mappings?

Suppose Process A has mapped a device file (say F) at address
0xaaaaaaaa in its address space. Is it possible for process B to see
the same device file F contents as process A via shared memory
mappings? If mapped in process B's address space, would process B
continue to to see the old contents if process A were to map a new
device file (say N) at the same address 0xaaaaaaaa in its address
space or do they have independent mappings?

So basically I'm trying to understand if there could be virtual to
virtual mappings (e.g. process B mapping process A's memory, so that B
sees whatever A sees)?

Thanks for your help!

-Riya