SYSENT
SYSENT[sysnum].sy_systrace_args_func = systrace_args;
SYSENT[sysnum].sy_entry = id;
SYSENT[sysnum].sy_return = id;
SYSENT[sysnum].sy_systrace_args_func = NULL;
SYSENT[sysnum].sy_entry = DTRACE_IDNONE;
SYSENT[sysnum].sy_return = DTRACE_IDNONE;