1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
|
/* Test the stack overflow handler.
Copyright (C) 2002-2023 Free Software Foundation, Inc.
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <https://www.gnu.org/licenses/>. */
/* Written by Bruno Haible and Eric Blake. */
#include <config.h>
/* Specification. */
#include "sigsegv.h"
#include <stdio.h>
#include <limits.h>
#if HAVE_STACK_OVERFLOW_RECOVERY
# if defined _WIN32 && !defined __CYGWIN__
/* Windows doesn't have sigset_t. */
typedef int sigset_t;
# define sigemptyset(set)
# define sigprocmask(how,set,oldset)
# endif
# include <stddef.h> /* needed for NULL on SunOS4 */
# include <stdlib.h> /* for abort, exit */
# include <signal.h>
# include <setjmp.h>
# if HAVE_SETRLIMIT
# include <sys/types.h>
# include <sys/time.h>
# include <sys/resource.h>
# endif
# include "altstack-util.h"
static jmp_buf mainloop;
static sigset_t mainsigset;
static volatile int pass = 0;
static volatile char *stack_lower_bound;
static volatile char *stack_upper_bound;
static void
stackoverflow_handler_continuation (void *arg1, void *arg2, void *arg3)
{
int arg = (int) (long) arg1;
longjmp (mainloop, arg);
}
static void
stackoverflow_handler (int emergency, stackoverflow_context_t scp)
{
char dummy;
volatile char *addr = &dummy;
if (!(addr >= stack_lower_bound && addr <= stack_upper_bound))
abort ();
pass++;
printf ("Stack overflow %d caught.\n", pass);
sigprocmask (SIG_SETMASK, &mainsigset, NULL);
sigsegv_leave_handler (stackoverflow_handler_continuation,
(void *) (long) (emergency ? -1 : pass), NULL, NULL);
}
static volatile int *
recurse_1 (int n, volatile int *p)
{
if (n < INT_MAX)
*recurse_1 (n + 1, p) += n;
return p;
}
static int
recurse (volatile int n)
{
return *recurse_1 (n, &n);
}
int
main ()
{
sigset_t emptyset;
# if HAVE_SETRLIMIT && defined RLIMIT_STACK
/* Before starting the endless recursion, try to be friendly to the user's
machine. On some Linux 2.2.x systems, there is no stack limit for user
processes at all. We don't want to kill such systems. */
struct rlimit rl;
rl.rlim_cur = rl.rlim_max = 0x100000; /* 1 MB */
setrlimit (RLIMIT_STACK, &rl);
# endif
/* Prepare the storage for the alternate stack. */
prepare_alternate_stack ();
/* Install the stack overflow handler. */
if (stackoverflow_install_handler (&stackoverflow_handler,
mystack, MYSTACK_SIZE)
< 0)
exit (2);
stack_lower_bound = mystack;
stack_upper_bound = mystack + MYSTACK_SIZE - 1;
/* Save the current signal mask. */
sigemptyset (&emptyset);
sigprocmask (SIG_BLOCK, &emptyset, &mainsigset);
/* Provoke two stack overflows in a row. */
switch (setjmp (mainloop))
{
case -1:
printf ("emergency exit\n"); exit (1);
case 0: case 1:
printf ("Starting recursion pass %d.\n", pass + 1);
recurse (0);
printf ("no endless recursion?!\n"); exit (1);
case 2:
break;
default:
abort ();
}
/* Validate that the alternate stack did not overflow. */
check_alternate_stack_no_overflow ();
printf ("Test passed.\n");
exit (0);
}
#else
int
main ()
{
return 77;
}
#endif
|
