That is not true, dtrace cannot modify data and is specifically designed not to do so. It can however be used to leak information or read info out of other pro

That is not true, dtrace cannot modify data and is specifically designed not to do so. It can however be used to leak information or read info out of other processes. I was going to say that for this reason even on linux you can't ptrace processes that are not children of the current process (e.g. you can run something under strace, but not attach to an existing process unless you twiddle a flag or do it as root). Having said that, you CAN modify data with ptrace, unlike dtrace. So that's kindof an aside. In any case the idea is that one process can't hijack another even from the same user for ptrace.