OS-5192 need faster clock_gettime
Reviewed by: Jerry Jelinek <jerry.jelinek@joyent.com>
Reviewed by: Robert Mustacchi <rm@joyent.com>
Reviewed by: Joshua M. Clulow <jmc@joyent.com>
Reviewed by: Ryan Zezeski <ryan@zinascii.com>
OS-2844 lx brand should support 64-bit user-land
OS-3280 need a way to specify the root of a native system in the lx brand
OS-3279 lx brand should allow delegated datasets
Reviewed by: Jerry Jelinek <jerry.jelinek@joyent.com>

*** 123,132 ****
--- 123,133 ----
          0,                      /* nthreads */
          0,                      /* nzombies */
          0,                      /* ndaemons */
          0,                      /* pid */
          sigacthandler,          /* sigacthandler */
+         __setcontext,           /* setctxt */
          NULL,                   /* lwp_stacks */
          NULL,                   /* lwp_laststack */
          0,                      /* nfreestack */
          10,                     /* thread_stack_cache */
          NULL,                   /* ulwp_freelist */
*** 135,144 ****
--- 136,147 ----
          NULL,                   /* ulwp_replace_last */
          NULL,                   /* atforklist */
          NULL,                   /* robustlocks */
          NULL,                   /* robustlist */
          NULL,                   /* progname */
+         NULL,                   /* ub_broot */
+         NULL,                   /* ub_comm_page */
          NULL,                   /* __tdb_bootstrap */
          {                       /* tdb */
                  NULL,           /* tdb_sync_addr_hash */
                  0,              /* tdb_register_count */
                  0,              /* tdb_hash_alloc_failed */
*** 1218,1227 ****
--- 1221,1253 ----
  
  #ifdef __amd64
  extern void __proc64id(void);
  #endif
  
+ static void
+ init_auxv_data(uberdata_t *udp)
+ {
+         Dl_argsinfo_t args;
+ 
+         udp->ub_broot = NULL;
+         udp->ub_comm_page = NULL;
+         if (dlinfo(RTLD_SELF, RTLD_DI_ARGSINFO, &args) < 0)
+                 return;
+ 
+         while (args.dla_auxv->a_type != AT_NULL) {
+                 switch (args.dla_auxv->a_type) {
+                 case AT_SUN_BRAND_NROOT:
+                         udp->ub_broot = args.dla_auxv->a_un.a_ptr;
+                         break;
+                 case AT_SUN_COMMPAGE:
+                         udp->ub_comm_page = args.dla_auxv->a_un.a_ptr;
+                         break;
+                 }
+                 args.dla_auxv++;
+         }
+ }
+ 
  /*
   * libc_init() is called by ld.so.1 for library initialization.
   * We perform minimal initialization; enough to work with the main thread.
   */
  void
*** 1254,1263 ****
--- 1280,1297 ----
           * Every libc, regardless of which link map, must register __cleanup().
           */
          (void) _atexit(__cleanup);
  
          /*
+          * Every libc, regardless of link map, needs to go through and check
+          * its aux vectors.  Doing so will indicate whether or not this has
+          * been given a brand root (used to qualify various other data) or a
+          * comm page (to optimize certain system actions).
+          */
+         init_auxv_data(udp);
+ 
+         /*
           * We keep our uberdata on one of (a) the first alternate link map
           * or (b) the primary link map.  We switch to the primary link map
           * and stay there once we see it.  All intermediate link maps are
           * subject to being unloaded at any time.
           */