dlfcn/dlinfo.c

   1 /* dlinfo -- Get information from the dynamic linker.
   2    Copyright (C) 2003-2017 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, see
  17    <http://www.gnu.org/licenses/>.  */
  18
  19 #include <dlfcn.h>
  20 #include <link.h>
  21 #include <ldsodefs.h>
  22 #include <libintl.h>
  23
  24 #if !defined SHARED && IS_IN (libdl)
  25
  26 int
  27 dlinfo (void *handle, int request, void *arg)
  28 {
  29   return __dlinfo (handle, request, arg, RETURN_ADDRESS (0));
  30 }
  31
  32 #else
  33
  34 # include <dl-tls.h>
  35
  36 struct dlinfo_args
  37 {
  38   ElfW(Addr) caller;
  39   void *handle;
  40   int request;
  41   void *arg;
  42 };
  43
  44 static void
  45 dlinfo_doit (void *argsblock)
  46 {
  47   struct dlinfo_args *const args = argsblock;
  48   struct link_map *l = args->handle;
  49
  50 # if 0
  51   if (args->handle == RTLD_SELF)
  52     {
  53       Lmid_t nsid;
  54
  55       /* Find the highest-addressed object that CALLER is not below.  */
  56       for (nsid = 0; nsid < DL_NNS; ++nsid)
  57         for (l = GL(dl_ns)[nsid]._ns_loaded; l != NULL; l = l->l_next)
  58           if (caller >= l->l_map_start && caller < l->l_map_end
  59               && (l->l_contiguous || _dl_addr_inside_object (l, caller)))
  60             break;
  61
  62       if (l == NULL)
  63         _dl_signal_error (0, NULL, NULL, N_("\
  64 RTLD_SELF used in code not dynamically loaded"));
  65     }
  66 # endif
  67
  68   switch (args->request)
  69     {
  70     case RTLD_DI_CONFIGADDR:
  71     default:
  72       _dl_signal_error (0, NULL, NULL, N_("unsupported dlinfo request"));
  73       break;
  74
  75     case RTLD_DI_LMID:
  76       *(Lmid_t *) args->arg = l->l_ns;
  77       break;
  78
  79     case RTLD_DI_LINKMAP:
  80       *(struct link_map **) args->arg = l;
  81       break;
  82
  83     case RTLD_DI_SERINFO:
  84       _dl_rtld_di_serinfo (l, args->arg, false);
  85       break;
  86     case RTLD_DI_SERINFOSIZE:
  87       _dl_rtld_di_serinfo (l, args->arg, true);
  88       break;
  89
  90     case RTLD_DI_ORIGIN:
  91       strcpy (args->arg, l->l_origin);
  92       break;
  93
  94     case RTLD_DI_TLS_MODID:
  95       *(size_t *) args->arg = 0;
  96       *(size_t *) args->arg = l->l_tls_modid;
  97       break;
  98
  99     case RTLD_DI_TLS_DATA:
 100       {
 101         void *data = NULL;
 102         if (l->l_tls_modid != 0)
 103           data = GLRO(dl_tls_get_addr_soft) (l);
 104         *(void **) args->arg = data;
 105         break;
 106       }
 107     }
 108 }
 109
 110 int
 111 __dlinfo (void *handle, int request, void *arg DL_CALLER_DECL)
 112 {
 113 # ifdef SHARED
 114   if (__glibc_unlikely (_dlfcn_hook != NULL))
 115     return _dlfcn_hook->dlinfo (handle, request, arg,
 116                                 DL_CALLER);
 117 # endif
 118
 119   struct dlinfo_args args = { (ElfW(Addr)) DL_CALLER,
 120                               handle, request, arg };
 121   return _dlerror_run (&dlinfo_doit, &args) ? -1 : 0;
 122 }
 123 # ifdef SHARED
 124 strong_alias (__dlinfo, dlinfo)
 125 # endif
 126 #endif