1 /* Test the stack overflow handler.
2 Copyright (C) 2002-2021 Bruno Haible <bruno@clisp.org>
3 Copyright (C) 2010 Eric Blake <eblake@redhat.com>
5 This program is free software: you can redistribute it and/or modify
6 it under the terms of the GNU General Public License as published by
7 the Free Software Foundation; either version 2 of the License, or
8 (at your option) any later version.
10 This program 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
13 GNU General Public License for more details.
15 You should have received a copy of the GNU General Public License
16 along with this program. If not, see <https://www.gnu.org/licenses/>. */
26 #if HAVE_STACK_OVERFLOW_RECOVERY
28 # if defined _WIN32 && !defined __CYGWIN__
29 /* Windows doesn't have sigset_t. */
31 # define sigemptyset(set)
32 # define sigprocmask(how,set,oldset)
35 # include <stddef.h> /* needed for NULL on SunOS4 */
36 # include <stdlib.h> /* for abort, exit */
40 # include <sys/types.h>
41 # include <sys/time.h>
42 # include <sys/resource.h>
44 # include "altstack-util.h"
49 volatile int pass = 0;
51 volatile char *stack_lower_bound;
52 volatile char *stack_upper_bound;
55 stackoverflow_handler_continuation (void *arg1, void *arg2, void *arg3)
57 int arg = (int) (long) arg1;
58 longjmp (mainloop, arg);
62 stackoverflow_handler (int emergency, stackoverflow_context_t scp)
65 volatile char *addr = &dummy;
66 if (!(addr >= stack_lower_bound && addr <= stack_upper_bound))
69 printf ("Stack overflow %d caught.\n", pass);
70 sigprocmask (SIG_SETMASK, &mainsigset, NULL);
71 sigsegv_leave_handler (stackoverflow_handler_continuation,
72 (void *) (long) (emergency ? -1 : pass), NULL, NULL);
76 recurse_1 (int n, volatile int *p)
79 *recurse_1 (n + 1, p) += n;
84 recurse (volatile int n)
86 return *recurse_1 (n, &n);
94 # if HAVE_SETRLIMIT && defined RLIMIT_STACK
95 /* Before starting the endless recursion, try to be friendly to the user's
96 machine. On some Linux 2.2.x systems, there is no stack limit for user
97 processes at all. We don't want to kill such systems. */
99 rl.rlim_cur = rl.rlim_max = 0x100000; /* 1 MB */
100 setrlimit (RLIMIT_STACK, &rl);
103 /* Prepare the storage for the alternate stack. */
104 prepare_alternate_stack ();
106 /* Install the stack overflow handler. */
107 if (stackoverflow_install_handler (&stackoverflow_handler,
108 mystack, MYSTACK_SIZE)
111 stack_lower_bound = mystack;
112 stack_upper_bound = mystack + MYSTACK_SIZE - 1;
114 /* Save the current signal mask. */
115 sigemptyset (&emptyset);
116 sigprocmask (SIG_BLOCK, &emptyset, &mainsigset);
118 /* Provoke two stack overflows in a row. */
119 switch (setjmp (mainloop))
122 printf ("emergency exit\n"); exit (1);
124 printf ("Starting recursion pass %d.\n", pass + 1);
126 printf ("no endless recursion?!\n"); exit (1);
133 /* Validate that the alternate stack did not overflow. */
134 check_alternate_stack_no_overflow ();
136 printf ("Test passed.\n");