OS-5566 ppoll timeout calculation can overflow
Reviewed by: Jerry Jelinek <jerry.jelinek@joyent.com>
Reviewed by: Robert Mustacchi <rm@joyent.com>
Reviewed by: Alex Wilson <alex.wilson@joyent.com>
Approved by: Robert Mustacchi <rm@joyent.com>

*** 13,22 ****
--- 13,23 ----
   *
   * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
   * Use is subject to license terms.
   *
   * Copyright 2013 Nexenta Systems, Inc.  All rights reserved.
+  * Copyright 2016 Joyent, Inc.
   */
  
  /*
   * Copyright (c) 2013, 2015 by Delphix. All rights reserved.
   */
*** 259,268 ****
--- 260,277 ----
   */
  typedef longlong_t      hrtime_t;
  
  #if defined(_KERNEL) || defined(_FAKE_KERNEL)
  
+ /*
+  * Unsigned counterpart to hrtime_t
+  */
+ typedef u_longlong_t    uhrtime_t;
+ 
+ #define HRTIME_MAX      LLONG_MAX
+ #define UHRTIME_MAX     ULLONG_MAX
+ 
  #include <sys/time_impl.h>
  #include <sys/mutex.h>
  
  extern int tick_per_msec;       /* clock ticks per millisecond (may be zero) */
  extern int msec_per_tick;       /* milliseconds per clock tick (may be zero) */