Nope, that'll just get you the addresses being freed. This, on the other hand, seems to do what I expected: dtrace -n 'pid$target::free:entry { printf("%s:

Nope, that'll just get you the addresses being freed. This, on the other hand, seems to do what I expected: dtrace -n 'pid$target::free:entry { printf("%s: %s", probefunc, copyinstr(arg0)); }' -p <pid>