Uprobes returns - again

The comment from the linked announcement:
"2. Much better handling of multithreaded programs because of XOL.
Current ptrace based mechanisms use single stepping inline, i.e they
copy back the original instruction on hitting a breakpoint."

Is not true. Maemo functracer (user-space) tool uses XOL with ptrace:
http://stage.maemo.org/pool/fremantle/free/f/functracer/

I think even the first versions from 2008 did that:
http://stage.maemo.org/pool/diablo/free/f/functracer/