11927 Log, or optionally panic, on zero-length kmem allocations
Reviewed by: Dan McDonald <danmcd@joyent.com>
Reviewed by: Jason King <jason.brian.king@gmail.com>

*** 22,31 ****
--- 22,32 ----
   * Copyright 2010 Sun Microsystems, Inc.  All rights reserved.
   * Use is subject to license terms.
   */
  /*
   * Copyright 2012 Garrett D'Amore <garrett@damore.org>.  All rights reserved.
+  * Copyright (c) 2015 Joyent, Inc.  All rights reserved.
   */
  /*
   * Fibre channel Transport Library (fctl)
   *
   * Function naming conventions:
*** 5498,5507 ****
--- 5499,5513 ----
          for (fca_port = fctl_fca_portlist; fca_port != NULL;
              fca_port = fca_port->port_next) {
                  maxPorts ++;
          }
  
+         if (maxPorts == 0) {
+                 mutex_exit(&fctl_port_lock);
+                 return (0);
+         }
+ 
          /* Now allocate a buffer to store all the pointers for comparisons */
          portList = kmem_zalloc(sizeof (fc_local_port_t *) * maxPorts, KM_SLEEP);
  
          for (fca_port = fctl_fca_portlist; fca_port != NULL;
              fca_port = fca_port->port_next) {