we need a widget either in the systemtap runtime proper, or within staprun/stapio, to tell a probe the memory layout of a given user process. This is basically the contents of /proc/$$/maps, and is necessary in order to place kprobes, relocate unwind/symbol data, and probably other stuff too. Some of it needs to be available by probe initialization (uprobe placement) time. It needs to be kept reasonably up to date, and readable without taking sleepy locks (for backtrace purposes).
Roland's utrace TODO list (http://people.redhat.com/roland/utrace/TODO) includes a "mmap change event," which would presumably call a client callback when a VM area is created/removed/resized/moved. If you could create an initial map (possibly in a sleepy context) and then catch map changes as they happen, you could have an up-to-date version available even in can't-sleep contexts.
*** This bug has been marked as a duplicate of 5951 ***