1  /* Test for unloading (really unmapping) of objects.  By Franz Sirl.
       2     This test does not have to passed in all dlopen() et.al. implementation
       3     since it is not required the unloading actually happens.  But we
       4     require it for glibc.  */
       5  
       6  #include <dlfcn.h>
       7  #include <link.h>
       8  #include <mcheck.h>
       9  #include <stdio.h>
      10  #include <stdlib.h>
      11  
      12  #define MAPS ((struct link_map *) _r_debug.r_map)
      13  
      14  #define OUT \
      15    for (map = MAPS; map != NULL; map = map->l_next)			      \
      16      if (map->l_type == lt_loaded)					      \
      17        printf ("name = \"%s\", direct_opencount = %d\n",			      \
      18  	      map->l_name, (int) map->l_direct_opencount);		      \
      19    fflush (stdout)
      20  
      21  typedef struct
      22  {
      23    void *next;
      24  } strct;
      25  
      26  int
      27  main (void)
      28  {
      29     void *sohandle;
      30     strct *testdat;
      31     int ret;
      32     int result = 0;
      33     struct link_map *map;
      34  
      35     mtrace ();
      36  
      37     puts ("\nBefore");
      38     OUT;
      39  
      40     sohandle = dlopen ("unloadmod.so", RTLD_NOW | RTLD_GLOBAL);
      41     if (sohandle == NULL)
      42       {
      43         printf ("*** first dlopen failed: %s\n", dlerror ());
      44         exit (1);
      45       }
      46  
      47     puts ("\nAfter loading unloadmod.so");
      48     OUT;
      49  
      50     testdat = dlsym (sohandle, "testdat");
      51     testdat->next = (void *) -1;
      52  
      53     ret = dlclose (sohandle);
      54     if (ret != 0)
      55       {
      56         puts ("*** first dlclose failed");
      57         result = 1;
      58       }
      59  
      60     puts ("\nAfter closing unloadmod.so");
      61     OUT;
      62  
      63     sohandle = dlopen ("unloadmod.so", RTLD_NOW | RTLD_GLOBAL);
      64     if (sohandle == NULL)
      65       {
      66         printf ("*** second dlopen failed: %s\n", dlerror ());
      67         exit (1);
      68       }
      69  
      70     puts ("\nAfter loading unloadmod.so the second time");
      71     OUT;
      72  
      73     testdat = dlsym (sohandle, "testdat");
      74     if (testdat->next == (void *) -1)
      75       {
      76         puts ("*** testdat->next == (void *) -1");
      77         result = 1;
      78       }
      79  
      80     ret = dlclose (sohandle);
      81     if (ret != 0)
      82       {
      83         puts ("*** second dlclose failed");
      84         result = 1;
      85       }
      86  
      87     puts ("\nAfter closing unloadmod.so again");
      88     OUT;
      89  
      90     return result;
      91  }