dtrace -s script.d -c binary Not working

[codeorcode]

I am trying to run this script:

!/usr/sbin/dtrace -q

syscall::read:entry,
syscall::write:entry
/pid == $target/
{
printf("execname:%s | %s(%d, 0x%x, %4d)", execname, probefunc, arg0, arg1, arg2);
printf("\n\t\t\t\t\ttest: %s", copyinstr(arg1));
}

syscall::read:return,
syscall::write:return
/pid == $target/
{
printf("\t\t = %d\n", arg1);
}

The command is: dtrace -s script.d -c "./a.out"

The command should display all reads and writes by my a.out app then exit. But instead it will not exit. I've replaced a.out with a linux command like netstat or ls. Still the script will not exit.

[root@centos6 ~]# dtrace -s b.d -c ./a.out
parent: waiting for child
parent: after waitpid pid=10187 status=137f
child 10187 about to exec ./a.out
rd_loadobj_iter
rd_loadobj_iter: /lib64/ld-2.12.so 0x7f216aee5000
proc-stub:rd_event_enable
proc-stub:rd_event_addr addr=(nil)
proc-stub:rd_event_addr addr=(nil)
proc-stub:rd_event_addr addr=(nil)
dtrace: script 'b.d' matched 8 probes

�CentOS is version 6.6, kernel: 2.6.32-504.23.4.el6.x86_64

Any hint what should I do next?