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 # include <dl-tls.h>
  36
  37 struct dlinfo_args
  38 {
  39   ElfW(Addr) caller;
  40   void *handle;
  41   int request;
  42   void *arg;
  43 };
  44
  45 static void
  46 dlinfo_doit (void *argsblock)
  47 {
  48   struct dlinfo_args *const args = argsblock;
  49   struct link_map *l = args->handle;
  50
  51 # if 0
  52   if (args->handle == RTLD_SELF)
  53     {
  54       Lmid_t nsid;
  55
  56       /* Find the highest-addressed object that CALLER is not below.  */
  57       for (nsid = 0; nsid < DL_NNS; ++nsid)
  58         for (l = GL(dl_ns)[nsid]._ns_loaded; l != NULL; l = l->l_next)
  59           if (caller >= l->l_map_start && caller < l->l_map_end)
  60             /* There must be exactly one DSO for the range of the virtual
  61                memory.  Otherwise something is really broken.  */
  62             break;
  63
  64       if (l == NULL)
  65         GLRO(dl_signal_error) (0, NULL, NULL, N_("\
  66 RTLD_SELF used in code not dynamically loaded"));
  67     }
  68 # endif
  69
  70   switch (args->request)
  71     {
  72     case RTLD_DI_CONFIGADDR:
  73     default:
  74       GLRO(dl_signal_error) (0, NULL, NULL, N_("unsupported dlinfo request"));
  75       break;
  76
  77     case RTLD_DI_LMID:
  78       *(Lmid_t *) args->arg = l->l_ns;
  79       break;
  80
  81     case RTLD_DI_LINKMAP:
  82       *(struct link_map **) args->arg = l;
  83       break;
  84
  85     case RTLD_DI_SERINFO:
  86       _dl_rtld_di_serinfo (l, args->arg, false);
  87       break;
  88     case RTLD_DI_SERINFOSIZE:
  89       _dl_rtld_di_serinfo (l, args->arg, true);
  90       break;
  91
  92     case RTLD_DI_ORIGIN:
  93       strcpy (args->arg, l->l_origin);
  94       break;
  95
  96     case RTLD_DI_TLS_MODID:
  97       *(size_t *) args->arg = 0;
  98       *(size_t *) args->arg = l->l_tls_modid;
  99       break;
 100
 101     case RTLD_DI_TLS_DATA:
 102       {
 103         void *data = NULL;
 104         if (l->l_tls_modid != 0)
 105           data = _dl_tls_get_addr_soft (l);
 106         *(void **) args->arg = data;
 107         break;
 108       }
 109     }
 110 }
 111
 112 int
 113 __dlinfo (void *handle, int request, void *arg DL_CALLER_DECL)
 114 {
 115 # ifdef SHARED
 116   if (__builtin_expect (_dlfcn_hook != NULL, 0))
 117     return _dlfcn_hook->dlinfo (handle, request, arg,
 118                                 DL_CALLER);
 119 # endif
 120
 121   struct dlinfo_args args = { (ElfW(Addr)) DL_CALLER,
 122                               handle, request, arg };
 123   return _dlerror_run (&dlinfo_doit, &args) ? -1 : 0;
 124 }
 125 # ifdef SHARED
 126 strong_alias (__dlinfo, dlinfo)
 127 # endif
 128 #endif