elf/dl-init.c

   1 /* Return the next shared object initializer function not yet run.
   2    Copyright (C) 1995, 1996, 1998, 1999 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Library General Public License as
   7    published by the Free Software Foundation; either version 2 of the
   8    License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Library General Public License for more details.
  14
  15    You should have received a copy of the GNU Library General Public
  16    License along with the GNU C Library; see the file COPYING.LIB.  If not,
  17    write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  18    Boston, MA 02111-1307, USA.  */
  19
  20 #include <stddef.h>
  21 #include <elf/ldsodefs.h>
  22
  23
  24 /* Run initializers for MAP and its dependencies, in inverse dependency
  25    order (that is, leaf nodes first).  */
  26
  27 ElfW(Addr)
  28 internal_function
  29 _dl_init_next (struct r_scope_elem *searchlist)
  30 {
  31   unsigned int i;
  32
  33   /* The search list for symbol lookup is a flat list in top-down
  34      dependency order, so processing that list from back to front gets us
  35      breadth-first leaf-to-root order.  */
  36
  37   i = searchlist->r_nlist;
  38   while (i-- > 0)
  39     {
  40       struct link_map *l = searchlist->r_list[i];
  41       ElfW(Addr) *array;
  42
  43       if (l->l_init_called)
  44         /* This object is all done.  */
  45         continue;
  46
  47       /* Check for object which constructors we do not run here.
  48          XXX Maybe this should be pre-computed, but where?  */
  49       if (l->l_name[0] == '\0' && l->l_type == lt_executable)
  50         {
  51           l->l_init_called = 1;
  52           continue;
  53         }
  54
  55       /* Account for running next constructor.  */
  56       ++l->l_runcount;
  57
  58       if (l->l_runcount == 1)
  59         {
  60           /* Try running the DT_INIT constructor.  */
  61           if (l->l_info[DT_INIT])
  62             {
  63               /* Print a debug message if wanted.  */
  64               if (_dl_debug_impcalls)
  65                 _dl_debug_message (1, "\ncalling init: ",
  66                                    l->l_name[0] ? l->l_name : _dl_argv[0],
  67                                    "\n\n", NULL);
  68
  69               return l->l_addr + l->l_info[DT_INIT]->d_un.d_ptr;
  70             }
  71
  72           /* No DT_INIT, so go on with the array.  */
  73           ++l->l_runcount;
  74         }
  75
  76       if (l->l_runcount > l->l_initcount)
  77         {
  78           /* That were all of the constructors.  */
  79           l->l_runcount = 0;
  80           l->l_init_called = 1;
  81           continue;
  82         }
  83
  84       /* Print a debug message if wanted.  */
  85       if (_dl_debug_impcalls && l->l_info[DT_INIT] == NULL
  86           && l->l_runcount == 2)
  87         _dl_debug_message (1, "\ncalling init: ",
  88                            l->l_name[0] ? l->l_name : _dl_argv[0],
  89                            "\n\n", NULL);
  90
  91       array = (ElfW(Addr) *) l->l_info[DT_INIT_ARRAY]->d_un.d_ptr;
  92       return l->l_addr + array[l->l_runcount - 2];
  93       /* NOTREACHED */
  94     }
  95
  96
  97   /* Notify the debugger all new objects are now ready to go.  */
  98   _r_debug.r_state = RT_CONSISTENT;
  99   _dl_debug_state ();
 100
 101   return 0;
 102 }