}: probe description syscall::exece:return does not match any probes
bash-3.00#
Have you set the privileges for the zone to allow the use of dtrace.
I've tested this, set the limitpriv of the zone to default,dtrace_user,dtrace_proc and after this your dtrace-command from above showed one matching probe. I'm not sure, but AFAIK the dtrace_kernel is not possible in a zone.