[oracle@testdb admin]$ lsnrctl start
 
LSNRCTL for Linux: Version 11.2.0.4.0 - Production on 10-FEB-2018 00:28:40
 
Copyright (c) 1991, 2013, Oracle. All rights reserved.
 
Starting /u01/app/oracle/product/11.2.0/db_1/bin/tnslsnr: please wait...
 
TNSLSNR for Linux: Version 11.2.0.4.0 - Production
System parameter file is /u01/app/oracle/product/11.2.0/db_1/network/admin/listener.ora
Log messages written to /u01/app/oracle/diag/tnslsnr/orcl/listener/alert/log.xml
Error listening on: (DESCRIPTION=(ADDRESS=(PROTOCOL=IPC)(KEY=EXTPROC1521)))
TNS-12555: TNS:permission denied
 TNS-12560: TNS:protocol adapter error
  TNS-00525: Insufficient privilege for operation
   Linux Error: 1: Operation not permitted
 
Listener failed to start. See the error message(s) above...
 
 
 
解决方法：
[root@testdb ~]# chmod -R 777 /var/tmp/.oracle
 
参考文档： Listener Fails To Start With IPC Permission Errors (TNS-12546 TNS-12555 TNS-00516 TNS-00525) (文档 ID 434062.1)