elf/dl-iteratephdr.c

   1 /* Get loaded objects program headers.
   2    Copyright (C) 2001-2012 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4    Contributed by Jakub Jelinek <jakub@redhat.com>, 2001.
   5
   6    The GNU C Library is free software; you can redistribute it and/or
   7    modify it under the terms of the GNU Lesser General Public License as
   8    published by the Free Software Foundation; either version 2.1 of the
   9    License, or (at your option) any later version.
  10
  11    The GNU C Library is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14    Lesser General Public License for more details.
  15
  16    You should have received a copy of the GNU Lesser General Public
  17    License along with the GNU C Library; see the file COPYING.LIB.  If
  18    not, see <http://www.gnu.org/licenses/>.  */
  19
  20 #include <errno.h>
  21 #include <ldsodefs.h>
  22 #include <stddef.h>
  23 #include <bits/libc-lock.h>
  24
  25 static void
  26 cancel_handler (void *arg __attribute__((unused)))
  27 {
  28   __rtld_lock_unlock_recursive (GL(dl_load_write_lock));
  29 }
  30
  31 hidden_proto (__dl_iterate_phdr)
  32 int
  33 __dl_iterate_phdr (int (*callback) (struct dl_phdr_info *info,
  34                                     size_t size, void *data), void *data)
  35 {
  36   struct link_map *l;
  37   struct dl_phdr_info info;
  38   int ret = 0;
  39
  40   /* Make sure nobody modifies the list of loaded objects.  */
  41   __rtld_lock_lock_recursive (GL(dl_load_write_lock));
  42   __libc_cleanup_push (cancel_handler, NULL);
  43
  44   /* We have to determine the namespace of the caller since this determines
  45      which namespace is reported.  */
  46   size_t nloaded = GL(dl_ns)[0]._ns_nloaded;
  47   Lmid_t ns = 0;
  48 #ifdef SHARED
  49   const void *caller = RETURN_ADDRESS (0);
  50   for (Lmid_t cnt = GL(dl_nns) - 1; cnt > 0; --cnt)
  51     for (struct link_map *l = GL(dl_ns)[cnt]._ns_loaded; l; l = l->l_next)
  52       {
  53         /* We have to count the total number of loaded objects.  */
  54         nloaded += GL(dl_ns)[cnt]._ns_nloaded;
  55
  56         if (caller >= (const void *) l->l_map_start
  57             && caller < (const void *) l->l_map_end
  58             && (l->l_contiguous
  59                 || _dl_addr_inside_object (l, (ElfW(Addr)) caller)))
  60           ns = cnt;
  61       }
  62 #endif
  63
  64   for (l = GL(dl_ns)[ns]._ns_loaded; l != NULL; l = l->l_next)
  65     {
  66       info.dlpi_addr = l->l_real->l_addr;
  67       info.dlpi_name = l->l_real->l_name;
  68       info.dlpi_phdr = l->l_real->l_phdr;
  69       info.dlpi_phnum = l->l_real->l_phnum;
  70       info.dlpi_adds = GL(dl_load_adds);
  71       info.dlpi_subs = GL(dl_load_adds) - nloaded;
  72       info.dlpi_tls_data = NULL;
  73       info.dlpi_tls_modid = l->l_real->l_tls_modid;
  74       if (info.dlpi_tls_modid != 0)
  75         info.dlpi_tls_data = GLRO(dl_tls_get_addr_soft) (l->l_real);
  76       ret = callback (&info, sizeof (struct dl_phdr_info), data);
  77       if (ret)
  78         break;
  79     }
  80
  81   /* Release the lock.  */
  82   __libc_cleanup_pop (0);
  83   __rtld_lock_unlock_recursive (GL(dl_load_write_lock));
  84
  85   return ret;
  86 }
  87 hidden_def (__dl_iterate_phdr)
  88
  89 #ifdef SHARED
  90
  91 weak_alias (__dl_iterate_phdr, dl_iterate_phdr);
  92
  93 #else
  94
  95 /* dl-support.c defines these and initializes them early on.  */
  96 extern ElfW(Phdr) *_dl_phdr;
  97 extern size_t _dl_phnum;
  98
  99 int
 100 dl_iterate_phdr (int (*callback) (struct dl_phdr_info *info,
 101                                   size_t size, void *data), void *data)
 102 {
 103   if (_dl_phnum != 0)
 104     {
 105       /* This entry describes this statically-linked program itself.  */
 106       struct dl_phdr_info info;
 107       int ret;
 108       info.dlpi_addr = 0;
 109       info.dlpi_name = "";
 110       info.dlpi_phdr = _dl_phdr;
 111       info.dlpi_phnum = _dl_phnum;
 112       info.dlpi_adds = GL(dl_load_adds);
 113       info.dlpi_subs = GL(dl_load_adds) - GL(dl_ns)[LM_ID_BASE]._ns_nloaded;
 114       ret = (*callback) (&info, sizeof (struct dl_phdr_info), data);
 115       if (ret)
 116         return ret;
 117     }
 118
 119   return __dl_iterate_phdr (callback, data);
 120 }
 121
 122
 123 #endif