dlfcn/dlinfo.c

   1 /* dlinfo -- Get information from the dynamic linker.
   2    Copyright (C) 2003, 2004, 2006 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 Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the 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    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, write to the Free
  17    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  18    02111-1307 USA.  */
  19
  20 #include <dlfcn.h>
  21 #include <link.h>
  22 #include <ldsodefs.h>
  23 #include <libintl.h>
  24
  25 #if !defined SHARED && defined IS_IN_libdl
  26
  27 int
  28 dlinfo (void *handle, int request, void *arg)
  29 {
  30   return __dlinfo (handle, request, arg, RETURN_ADDRESS (0));
  31 }
  32
  33 #else
  34
  35 # ifdef USE_TLS
  36 #  include <dl-tls.h>
  37 # endif
  38
  39 struct dlinfo_args
  40 {
  41   ElfW(Addr) caller;
  42   void *handle;
  43   int request;
  44   void *arg;
  45 };
  46
  47 static void
  48 dlinfo_doit (void *argsblock)
  49 {
  50   struct dlinfo_args *const args = argsblock;
  51   struct link_map *l = args->handle;
  52
  53 # if 0
  54   if (args->handle == RTLD_SELF)
  55     {
  56       Lmid_t nsid;
  57
  58       /* Find the highest-addressed object that CALLER is not below.  */
  59       for (nsid = 0; nsid < DL_NNS; ++nsid)
  60         for (l = GL(dl_ns)[nsid]._ns_loaded; l != NULL; l = l->l_next)
  61           if (caller >= l->l_map_start && caller < l->l_map_end)
  62             /* There must be exactly one DSO for the range of the virtual
  63                memory.  Otherwise something is really broken.  */
  64             break;
  65
  66       if (l == NULL)
  67         GLRO(dl_signal_error) (0, NULL, NULL, N_("\
  68 RTLD_SELF used in code not dynamically loaded"));
  69     }
  70 # endif
  71
  72   switch (args->request)
  73     {
  74     case RTLD_DI_CONFIGADDR:
  75     default:
  76       GLRO(dl_signal_error) (0, NULL, NULL, N_("unsupported dlinfo request"));
  77       break;
  78
  79     case RTLD_DI_LMID:
  80       *(Lmid_t *) args->arg = l->l_ns;
  81       break;
  82
  83     case RTLD_DI_LINKMAP:
  84       *(struct link_map **) args->arg = l;
  85       break;
  86
  87     case RTLD_DI_SERINFO:
  88       _dl_rtld_di_serinfo (l, args->arg, false);
  89       break;
  90     case RTLD_DI_SERINFOSIZE:
  91       _dl_rtld_di_serinfo (l, args->arg, true);
  92       break;
  93
  94     case RTLD_DI_ORIGIN:
  95       strcpy (args->arg, l->l_origin);
  96       break;
  97
  98     case RTLD_DI_TLS_MODID:
  99       *(size_t *) args->arg = 0;
 100 #ifdef USE_TLS
 101       *(size_t *) args->arg = l->l_tls_modid;
 102 #endif
 103       break;
 104
 105     case RTLD_DI_TLS_DATA:
 106       {
 107         void *data = NULL;
 108 #ifdef USE_TLS
 109         if (l->l_tls_modid != 0)
 110           data = _dl_tls_get_addr_soft (l);
 111 #endif
 112         *(void **) args->arg = data;
 113         break;
 114       }
 115     }
 116 }
 117
 118 int
 119 __dlinfo (void *handle, int request, void *arg DL_CALLER_DECL)
 120 {
 121 # ifdef SHARED
 122   if (__builtin_expect (_dlfcn_hook != NULL, 0))
 123     return _dlfcn_hook->dlinfo (handle, request, arg,
 124                                 DL_CALLER);
 125 # endif
 126
 127   struct dlinfo_args args = { (ElfW(Addr)) DL_CALLER,
 128                               handle, request, arg };
 129   return _dlerror_run (&dlinfo_doit, &args) ? -1 : 0;
 130 }
 131 # ifdef SHARED
 132 strong_alias (__dlinfo, dlinfo)
 133 # endif
 134 #endif