2916 DTrace in a zone should be able to access fds[]

*** 19,28 ****
--- 19,29 ----
   * CDDL HEADER END
   */
  
  /*
   * Copyright (c) 1989, 2010, Oracle and/or its affiliates. All rights reserved.
+  * Copyright (c) 2012, Joyent Inc. All rights reserved.
   */
  
  /*      Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T */
  /*      All Rights Reserved */
  
*** 52,61 ****
--- 53,63 ----
  #include <sys/atomic.h>
  #include <sys/fcntl.h>
  #include <sys/poll.h>
  #include <sys/rctl.h>
  #include <sys/port_impl.h>
+ #include <sys/dtrace.h>
  
  #include <c2/audit.h>
  #include <sys/nbmlock.h>
  
  #ifdef DEBUG
*** 950,959 ****
--- 952,973 ----
                  return (error);
          }
          ASSERT(fp->f_count == 0);
          mutex_exit(&fp->f_tlock);
  
+         /*
+          * If DTrace has getf() subroutines active, it will set dtrace_closef
+          * to point to code that implements a barrier with respect to probe
+          * context.  This must be called before the file_t is freed (and the
+          * vnode that it refers to is released) -- but it must be after the
+          * file_t has been removed from the uf_entry_t.  That is, there must
+          * be no way for a racing getf() in probe context to yield the fp that
+          * we're operating upon.
+          */
+         if (dtrace_closef != NULL)
+                 (*dtrace_closef)();
+ 
          VN_RELE(vp);
          /*
           * deallocate resources to audit_data
           */
          if (audit_active)