elf/tst-nodelete-dlclose-dso.c

   1 /* Bug 11941: Improper assert map->l_init_called in dlclose.
   2    Copyright (C) 2016-2017 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 /* This is the primary DSO that is loaded by the appliation.  This DSO
  20    then loads a plugin with RTLD_NODELETE.  This plugin depends on this
  21    DSO.  This dependency chain means that at application shutdown the
  22    plugin will be destructed first.  Thus by the time this DSO is
  23    destructed we will be calling dlclose on an object that has already
  24    been destructed.  It is allowed to call dlclose in this way and
  25    should not assert.  */
  26 #include <stdio.h>
  27 #include <stdlib.h>
  28 #include <dlfcn.h>
  29
  30 /* Plugin to load.  */
  31 static void *plugin_lib = NULL;
  32 /* Plugin function.  */
  33 static void (*plugin_func) (void);
  34 #define LIB_PLUGIN "tst-nodelete-dlclose-plugin.so"
  35
  36 /* This function is never called but the plugin references it.
  37    We do this to avoid any future --as-needed from removing the
  38    plugin's DT_NEEDED on this DSO (required for the test).  */
  39 void
  40 primary_reference (void)
  41 {
  42   printf ("INFO: Called primary_reference function.\n");
  43 }
  44
  45 void
  46 primary (void)
  47 {
  48   char *error;
  49
  50   plugin_lib = dlopen (LIB_PLUGIN, RTLD_NOW | RTLD_LOCAL | RTLD_NODELETE);
  51   if (plugin_lib == NULL)
  52     {
  53       printf ("ERROR: Unable to load plugin library.\n");
  54       exit (EXIT_FAILURE);
  55     }
  56   dlerror ();
  57
  58   plugin_func = (void (*) (void)) dlsym (plugin_lib, "plugin_func");
  59   error = dlerror ();
  60   if (error != NULL)
  61     {
  62       printf ("ERROR: Unable to find symbol with error \"%s\".",
  63               error);
  64       exit (EXIT_FAILURE);
  65     }
  66
  67   return;
  68 }
  69
  70 __attribute__ ((destructor))
  71 static void
  72 primary_dtor (void)
  73 {
  74   int ret;
  75
  76   printf ("INFO: Calling primary destructor.\n");
  77
  78   /* The destructor runs in the test driver also, which
  79      hasn't called primary, in that case do nothing.  */
  80   if (plugin_lib == NULL)
  81     return;
  82
  83   ret = dlclose (plugin_lib);
  84   if (ret != 0)
  85     {
  86       printf ("ERROR: Calling dlclose failed with \"%s\"\n",
  87               dlerror ());
  88       exit (EXIT_FAILURE);
  89     }
  90 }