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>

*** 22,32 ****
  /*
   * Copyright 2005 Sun Microsystems, Inc.  All rights reserved.
   * Use is subject to license terms.
   */
  
! #pragma ident   "%Z%%M% %I%     %E% SMI"
  
  #include <sys/promif.h>
  #include <sys/promimpl.h>
  #include <sys/prom_emul.h>
  #include <sys/obpdefs.h>
--- 22,34 ----
  /*
   * Copyright 2005 Sun Microsystems, Inc.  All rights reserved.
   * Use is subject to license terms.
   */
  
! /*
!  * Copyright (c) 2015 Joyent, Inc.  All rights reserved.
!  */
  
  #include <sys/promif.h>
  #include <sys/promimpl.h>
  #include <sys/prom_emul.h>
  #include <sys/obpdefs.h>
*** 44,54 ****
          struct prom_prop *p, *q;
  
          q = kmem_zalloc(sizeof (*q), KM_SLEEP);
          q->pp_name = kmem_zalloc(strlen(name) + 1, KM_SLEEP);
          (void) strcpy(q->pp_name, name);
!         q->pp_val = kmem_alloc(len, KM_SLEEP);
          q->pp_len = len;
          switch (flags) {
          case DDI_PROP_TYPE_INT:
          case DDI_PROP_TYPE_INT64:
                  /*
--- 46,56 ----
          struct prom_prop *p, *q;
  
          q = kmem_zalloc(sizeof (*q), KM_SLEEP);
          q->pp_name = kmem_zalloc(strlen(name) + 1, KM_SLEEP);
          (void) strcpy(q->pp_name, name);
!         q->pp_val = len > 0 ? kmem_alloc(len, KM_SLEEP) : NULL;
          q->pp_len = len;
          switch (flags) {
          case DDI_PROP_TYPE_INT:
          case DDI_PROP_TYPE_INT64:
                  /*