dlfcn/dlinfo.c

   1 /* dlinfo -- Get information from the dynamic linker.
   2    Copyright (C) 2003-2021 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    <https://www.gnu.org/licenses/>.  */
  18
  19 #include <dlfcn.h>
  20 #include <link.h>
  21 #include <ldsodefs.h>
  22 #include <libintl.h>
  23 #include <dl-tls.h>
  24 #include <shlib-compat.h>
  25
  26 struct dlinfo_args
  27 {
  28   void *handle;
  29   int request;
  30   void *arg;
  31 };
  32
  33 static void
  34 dlinfo_doit (void *argsblock)
  35 {
  36   struct dlinfo_args *const args = argsblock;
  37   struct link_map *l = args->handle;
  38
  39   switch (args->request)
  40     {
  41     case RTLD_DI_CONFIGADDR:
  42     default:
  43       _dl_signal_error (0, NULL, NULL, N_("unsupported dlinfo request"));
  44       break;
  45
  46     case RTLD_DI_LMID:
  47       *(Lmid_t *) args->arg = l->l_ns;
  48       break;
  49
  50     case RTLD_DI_LINKMAP:
  51       *(struct link_map **) args->arg = l;
  52       break;
  53
  54     case RTLD_DI_SERINFO:
  55       _dl_rtld_di_serinfo (l, args->arg, false);
  56       break;
  57     case RTLD_DI_SERINFOSIZE:
  58       _dl_rtld_di_serinfo (l, args->arg, true);
  59       break;
  60
  61     case RTLD_DI_ORIGIN:
  62       strcpy (args->arg, l->l_origin);
  63       break;
  64
  65     case RTLD_DI_TLS_MODID:
  66       *(size_t *) args->arg = 0;
  67       *(size_t *) args->arg = l->l_tls_modid;
  68       break;
  69
  70     case RTLD_DI_TLS_DATA:
  71       {
  72         void *data = NULL;
  73         if (l->l_tls_modid != 0)
  74           data = GLRO(dl_tls_get_addr_soft) (l);
  75         *(void **) args->arg = data;
  76         break;
  77       }
  78     }
  79 }
  80
  81 static int
  82 dlinfo_implementation (void *handle, int request, void *arg)
  83 {
  84   struct dlinfo_args args = { handle, request, arg };
  85   return _dlerror_run (&dlinfo_doit, &args) ? -1 : 0;
  86 }
  87
  88 #ifdef SHARED
  89 int
  90 ___dlinfo (void *handle, int request, void *arg)
  91 {
  92   if (!rtld_active ())
  93     return GLRO (dl_dlfcn_hook)->dlinfo (handle, request, arg);
  94   else
  95     return dlinfo_implementation (handle, request, arg);
  96 }
  97 versioned_symbol (libc, ___dlinfo, dlinfo, GLIBC_2_34);
  98
  99 # if OTHER_SHLIB_COMPAT (libdl, GLIBC_2_3_3, GLIBC_2_34)
 100 compat_symbol (libc, ___dlinfo, dlinfo, GLIBC_2_3_3);
 101 # endif
 102 #else /* !SHARED */
 103 /* Also used with _dlfcn_hook.  */
 104 int
 105 __dlinfo (void *handle, int request, void *arg)
 106 {
 107   return dlinfo_implementation (handle, request, arg);
 108 }
 109 weak_alias (__dlinfo, dlinfo)
 110 #endif