Besides that, here's a headscratcher (although the question is just a pure why rather than it getting in the way of a solution at the moment): /dev/shm DOES show up as mounted if you run 'mount'. rdmod segfaults. Then you run 'mount -t tmpfs tmpfs /dev/shm'. /dev/shm shows up in the same exact way in 'mount' output again. No change what so ever. Yet rdmod stops segfaulting.