support/tst-xsigstack.c

   1 /* Test of sigaltstack wrappers.
   2    Copyright (C) 2019-2022 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>