1  /* Check CET compatibility with legacy JIT engine via GLIBC_TUNABLES.
       2     Copyright (C) 2021-2023 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     <https://www.gnu.org/licenses/>.  */
      18  
      19  #include <stdio.h>
      20  #include <stdlib.h>
      21  #include <sys/mman.h>
      22  #include <support/test-driver.h>
      23  #include <support/xunistd.h>
      24  
      25  /* Check that mmapped legacy code won't trigger segfault with
      26     -fcf-protection and GLIBC_TUNABLES=glibc.cpu.hwcaps=-IBT,-SHSTK.  */
      27  
      28  static int
      29  do_test (void)
      30  {
      31    void (*funcp) (void);
      32    funcp = xmmap (NULL, 0x1000, PROT_EXEC | PROT_READ | PROT_WRITE,
      33  		 MAP_ANONYMOUS | MAP_PRIVATE, -1);
      34    printf ("mmap = %p\n", funcp);
      35    /* Write RET instruction.  */
      36    *(char *) funcp = 0xc3;
      37    funcp ();
      38    return EXIT_SUCCESS;
      39  }
      40  
      41  #include <support/test-driver.c>