elf/nodelete.c

   1 #include <dlfcn.h>
   2 #include <setjmp.h>
   3 #include <signal.h>
   4 #include <stdio.h>
   5
   6
   7 static sigjmp_buf jmpbuf;
   8
   9
  10 static void
  11 handler (int sig)
  12 {
  13   siglongjmp (jmpbuf, 1);
  14 }
  15
  16
  17 #define TEST_FUNCTION do_test ()
  18 static int
  19 do_test (void)
  20 {
  21   /* We are testing the two possibilities to mark an object as not deletable:
  22      - marked on the linker commandline with `-z nodelete'
  23      - with the RTLD_NODELETE flag at dlopen()-time.
  24
  25      The test we are performing should be safe.  We are loading the objects,
  26      get the address of variables in the respective object, unload the object
  27      and then try to read the variable.  If the object is unloaded this
  28      should lead to an segmentation fault.  */
  29   int result = 0;
  30   void *p;
  31   struct sigaction sa;
  32
  33   sa.sa_handler = handler;
  34   sigfillset (&sa.sa_mask);
  35   sa.sa_flags = SA_RESTART;
  36   sa.sa_restorer = NULL;
  37
  38   if (sigaction (SIGSEGV, &sa, NULL) == -1)
  39     printf ("cannot install signal handler: %m\n");
  40
  41   p = dlopen ("nodelmod1.so", RTLD_LAZY);
  42   if (p == NULL)
  43     {
  44       printf ("failed to load \"nodelmod1.so\": %s\n", dlerror ());
  45       result = 1;
  46     }
  47   else
  48     {
  49       int *varp;
  50
  51       puts ("succeeded loading \"nodelmod1.so\"");
  52
  53       varp = dlsym (p, "var1");
  54       if (varp == NULL)
  55         {
  56           puts ("failed to get address of \"var1\" in \"nodelmod1.so\"");
  57           result = 1;
  58         }
  59       else
  60         {
  61           *varp = 20000720;
  62
  63           /* Now close the object.  */
  64           if (dlclose (p) != 0)
  65             {
  66               puts ("failed to close \"nodelmod1.so\"");
  67               result = 1;
  68             }
  69           else if (! sigsetjmp (jmpbuf, 1))
  70             {
  71               /* Access the variable again.  */
  72               if (*varp != 20000720)
  73                 {
  74                   puts ("\"var1\" value not correct");
  75                   result = 1;
  76                 }
  77               else
  78                 puts ("-z nodelete test succeeded");
  79             }
  80           else
  81             {
  82               /* We caught an segmentation fault.  */
  83               puts ("\"nodelmod1.so\" got deleted");
  84               result = 1;
  85             }
  86         }
  87     }
  88
  89   p = dlopen ("nodelmod2.so", RTLD_LAZY | RTLD_NODELETE);
  90   if (p == NULL)
  91     {
  92       printf ("failed to load \"nodelmod2.so\": %s\n", dlerror ());
  93       result = 1;
  94     }
  95   else
  96     {
  97       int *varp;
  98
  99       puts ("succeeded loading \"nodelmod2.so\"");
 100
 101       varp = dlsym (p, "var2");
 102       if (varp == NULL)
 103         {
 104           puts ("failed to get address of \"var2\" in \"nodelmod2.so\"");
 105           result = 1;
 106         }
 107       else
 108         {
 109           *varp = 42;
 110
 111           /* Now close the object.  */
 112           if (dlclose (p) != 0)
 113             {
 114               puts ("failed to close \"nodelmod2.so\"");
 115               result = 1;
 116             }
 117           else if (! sigsetjmp (jmpbuf, 1))
 118             {
 119               /* Access the variable again.  */
 120               if (*varp != 42)
 121                 {
 122                   puts ("\"var2\" value not correct");
 123                   result = 1;
 124                 }
 125               else
 126                 puts ("RTLD_NODELETE test succeeded");
 127             }
 128           else
 129             {
 130               /* We caught an segmentation fault.  */
 131               puts ("\"nodelmod2.so\" got deleted");
 132               result = 1;
 133             }
 134         }
 135     }
 136
 137   p = dlopen ("nodelmod3.so", RTLD_LAZY);
 138   if (p == NULL)
 139     {
 140       printf ("failed to load \"nodelmod3.so\": %s\n", dlerror ());
 141       result = 1;
 142     }
 143   else
 144     {
 145       int *(*fctp) (void);
 146
 147       puts ("succeeded loading \"nodelmod3.so\"");
 148
 149       fctp = dlsym (p, "addr");
 150       if (fctp == NULL)
 151         {
 152           puts ("failed to get address of \"addr\" in \"nodelmod3.so\"");
 153           result = 1;
 154         }
 155       else
 156         {
 157           int *varp = fctp ();
 158
 159           *varp = -1;
 160
 161           /* Now close the object.  */
 162           if (dlclose (p) != 0)
 163             {
 164               puts ("failed to close \"nodelmod3.so\"");
 165               result = 1;
 166             }
 167           else if (! sigsetjmp (jmpbuf, 1))
 168             {
 169               /* Access the variable again.  */
 170               if (*varp != -1)
 171                 {
 172                   puts ("\"var_in_mod4\" value not correct");
 173                   result = 1;
 174                 }
 175               else
 176                 puts ("-z nodelete in dependency succeeded");
 177             }
 178           else
 179             {
 180               /* We caught an segmentation fault.  */
 181               puts ("\"nodelmod4.so\" got deleted");
 182               result = 1;
 183             }
 184         }
 185     }
 186
 187   return result;
 188 }
 189
 190 #include "../test-skeleton.c"