1  /* Test of sigaltstack wrappers.
       2     Copyright (C) 2019-2023 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 <support/xsignal.h>
      20  #include <support/support.h>
      21  #include <support/xunistd.h>
      22  #include <support/check.h>
      23  
      24  #include <stdint.h>
      25  #include <stdio.h>
      26  
      27  static volatile uintptr_t handler_stackaddr;
      28  
      29  static void
      30  handler (int unused)
      31  {
      32    int var;
      33    handler_stackaddr = (uintptr_t) &var;
      34  }
      35  
      36  int
      37  do_test (void)
      38  {
      39    void *sstk = xalloc_sigstack (0);
      40  
      41    unsigned char *sp;
      42    size_t size;
      43    xget_sigstack_location (sstk, &sp, &size);
      44    printf ("signal stack installed: sp=%p size=%zu\n", sp, size);
      45  
      46    struct sigaction sa;
      47    sa.sa_handler = handler;
      48    sa.sa_flags   = SA_RESTART | SA_ONSTACK;
      49    sigfillset (&sa.sa_mask);
      50    if (sigaction (SIGUSR1, &sa, 0))
      51      FAIL_RET ("sigaction (SIGUSR1, handler): %m\n");
      52  
      53    raise (SIGUSR1);
      54  
      55    uintptr_t haddr = handler_stackaddr;
      56    printf ("address of handler local variable: %p\n", (void *)haddr);
      57    TEST_VERIFY ((uintptr_t)sp < haddr);
      58    TEST_VERIFY (haddr < (uintptr_t)sp + size);
      59  
      60    xfree_sigstack (sstk);
      61    return 0;
      62  }
      63  
      64  #include <support/test-driver.c>