1  /* Check compatibility of CET-enabled executable with dlopened legacy
       2     shared object.
       3     Copyright (C) 2019-2023 Free Software Foundation, Inc.
       4     This file is part of the GNU C Library.
       5  
       6     The GNU C Library is free software; you can redistribute it and/or
       7     modify it under the terms of the GNU Lesser General Public
       8     License as published by the Free Software Foundation; either
       9     version 2.1 of the License, or (at your option) any later version.
      10  
      11     The GNU C Library is distributed in the hope that it will be useful,
      12     but WITHOUT ANY WARRANTY; without even the implied warranty of
      13     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
      14     Lesser General Public License for more details.
      15  
      16     You should have received a copy of the GNU Lesser General Public
      17     License along with the GNU C Library; if not, see
      18     <https://www.gnu.org/licenses/>.  */
      19  
      20  #include <dlfcn.h>
      21  #include <stdio.h>
      22  #include <stdlib.h>
      23  #include <stdbool.h>
      24  #include <string.h>
      25  #include <x86intrin.h>
      26  #include <support/check.h>
      27  
      28  #if defined CET_IS_PERMISSIVE || defined CET_DISABLED_BY_ENV
      29  # define CET_MAYBE_DISABLED 1
      30  #else
      31  # define CET_MAYBE_DISABLED 0
      32  #endif
      33  
      34  static void
      35  do_test_1 (const char *modname, bool fail)
      36  {
      37    int (*fp) (void);
      38    void *h;
      39  
      40    /* NB: dlopen should never fail on non-CET platforms.  If SHSTK is
      41       disabled, assuming IBT is also disabled.  */
      42    bool cet_enabled = _get_ssp () != 0 && !CET_MAYBE_DISABLED;
      43    if (!cet_enabled)
      44      fail = false;
      45  
      46    h = dlopen (modname, RTLD_LAZY);
      47    if (h == NULL)
      48      {
      49        const char *err = dlerror ();
      50        if (fail)
      51  	{
      52  	  if (strstr (err, "rebuild shared object with SHSTK support enabled")
      53  	      == NULL)
      54  	    FAIL_EXIT1 ("incorrect dlopen '%s' error: %s\n", modname, err);
      55  
      56  	  return;
      57  	}
      58  
      59        FAIL_EXIT1 ("cannot open '%s': %s\n", modname, err);
      60      }
      61  
      62    if (fail)
      63      FAIL_EXIT1 ("dlopen should have failed\n");
      64  
      65    fp = dlsym (h, "test");
      66    if (fp == NULL)
      67      {
      68        printf ("cannot get symbol 'test': %s\n", dlerror ());
      69        exit (1);
      70      }
      71  
      72    if (fp () != 0)
      73      {
      74        puts ("test () != 0");
      75        exit (1);
      76      }
      77  
      78    dlclose (h);
      79  }
      80  
      81  static int
      82  do_test (void)
      83  {
      84    do_test_1 ("tst-cet-legacy-mod-6a.so", true);
      85    do_test_1 ("tst-cet-legacy-mod-6b.so", false);
      86    return 0;
      87  }
      88  
      89  #include <support/test-driver.c>