1  /* Copyright (C) 2003-2023 Free Software Foundation, Inc.
       2     This file is part of the GNU C Library.
       3  
       4     The GNU C Library is free software; you can redistribute it and/or
       5     modify it under the terms of the GNU Lesser General Public
       6     License as published by the Free Software Foundation; either
       7     version 2.1 of the License, or (at your option) any later version.
       8  
       9     The GNU C Library is distributed in the hope that it will be useful,
      10     but WITHOUT ANY WARRANTY; without even the implied warranty of
      11     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
      12     Lesser General Public License for more details.
      13  
      14     You should have received a copy of the GNU Lesser General Public
      15     License along with the GNU C Library; if not, see
      16     <https://www.gnu.org/licenses/>.  */
      17  
      18  #include <setjmp.h>
      19  #include <signal.h>
      20  #include <stdio.h>
      21  #include <stdlib.h>
      22  #include <sys/types.h>
      23  
      24  static sigjmp_buf jmpbuf;
      25  
      26  static void
      27  sig_handler (int signo)
      28  {
      29    siglongjmp (jmpbuf, 1);
      30  }
      31  
      32  static int
      33  do_test (void)
      34  {
      35    char *p = NULL;
      36    /* gcc can overwrite the success written value by scheduling instructions
      37       around sprintf.  It is allowed to do this since according to C99 the first
      38       argument of sprintf is a character array and NULL is not a valid character
      39       array.  Mark the return value as volatile so that it gets reloaded on
      40       return.  */
      41    volatile int ret = 0;
      42  
      43    if (signal (SIGSEGV, &sig_handler) == SIG_ERR)
      44      {
      45        perror ("installing SIGSEGV handler");
      46        return 1;
      47      }
      48  
      49    puts ("Attempting to sprintf to null ptr");
      50    if (setjmp (jmpbuf))
      51      {
      52        puts ("Exiting main...");
      53        return ret;
      54      }
      55  
      56    sprintf (p, "This should segv\n");
      57  
      58    return 1;
      59  }
      60  
      61  #define TEST_FUNCTION do_test ()
      62  #include "../test-skeleton.c"