Question

From my research so far, Linux is moving away from allowing access to physical memory via the /dev/mem file. Unfortunately this is the case on Ubuntu 11.10, as /dev/mem does not exist.

Further research turned up the shm file as a way to pass memory between programs (http://www.cyberciti.biz/tips/what-is-devshm-and-its-practical-usage.html). This is to try to learn if /dev/shm is a valid substitute for hexdumping the contents of physical memory, e.g.,

dd if=/dev/shm bs=1024 count=10485576|hexdump -C > recovery.txt

Failing this, is there an alternate route to access physical memory in Linux when there is no /dev/mem?

Answer 1

You can’t use /dev/shm this way, it’s a temporary filesystem that only provides a way to access information specifically stored in it.

You are right that you can’t easily use /dev/mem this way. What’s your use case? There’s a probably a way to do what you want to do.