htl/tests/test-4.c

   1 /* Test the stack guard.
   2    Copyright (C) 2000-2023 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 #define _GNU_SOURCE
  20
  21 #include <pthread.h>
  22 #include <assert.h>
  23 #include <unistd.h>
  24 #include <errno.h>
  25 #include <string.h>
  26 #include <stdio.h>
  27
  28 size_t stacksize;
  29
  30 void *
  31 thr (void *arg)
  32 {
  33   int i;
  34   char *foo;
  35
  36   foo = alloca (3 * stacksize / 4);
  37   for (i = 0; i < sizeof foo; i++)
  38     foo[i] = -1;
  39
  40   return (void *) 1;
  41 }
  42
  43 int
  44 main (int argc, char *argv[])
  45 {
  46   error_t err;
  47   pid_t child;
  48
  49   child = fork ();
  50   switch (child)
  51     {
  52     case -1:
  53       error (1, errno, "fork");
  54       break;
  55
  56     case 0:
  57       {
  58         pthread_attr_t attr;
  59         pthread_t tid;
  60         void *ret;
  61
  62         err = pthread_attr_init (&attr);
  63         assert_perror (err);
  64
  65         err = pthread_attr_getstacksize (&attr, &stacksize);
  66         assert_perror (err);
  67
  68         err = pthread_attr_setguardsize (&attr, stacksize / 2);
  69         if (err == ENOTSUP)
  70           {
  71             printf ("Stack guard attribute not supported.\n");
  72             return 1;
  73           }
  74         assert_perror (err);
  75
  76         err = pthread_create (&tid, &attr, thr, 0);
  77         assert_perror (err);
  78
  79         err = pthread_attr_destroy (&attr);
  80         assert_perror (err);
  81
  82         err = pthread_join (tid, &ret);
  83         /* Should never be successful.  */
  84         printf ("Thread did not segfault!?!\n");
  85         assert_perror (err);
  86         return 0;
  87       }
  88
  89     default:
  90       {
  91         pid_t pid;
  92         int status;
  93
  94         pid = waitpid (child, &status, 0);
  95         printf ("pid = %d; child = %d; status = %d\n", pid, child, status);
  96         assert (pid == child);
  97         assert (status != 0);
  98       }
  99     }
 100
 101   return 0;
 102 }