1 /*
2  * SPDX-License-Identifier: BSD-3-Clause
3  *
4  * Copyright © 2020 Keith Packard
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  *
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  *
13  * 2. Redistributions in binary form must reproduce the above
14  *    copyright notice, this list of conditions and the following
15  *    disclaimer in the documentation and/or other materials provided
16  *    with the distribution.
17  *
18  * 3. Neither the name of the copyright holder nor the names of its
19  *    contributors may be used to endorse or promote products derived
20  *    from this software without specific prior written permission.
21  *
22  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
23  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
24  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
25  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
26  * COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
27  * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
28  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
29  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
31  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
32  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
33  * OF THE POSSIBILITY OF SUCH DAMAGE.
34  */
35 
36 #include <stdlib.h>
37 #include <malloc.h>
38 #include <string.h>
39 #include <stdio.h>
40 #include <stdint.h>
41 #include <unistd.h>
42 #include <stdbool.h>
43 #include <ssp/ssp.h>
44 
45 #ifdef TESTS_ENABLE_STACK_PROTECTOR
46 static volatile bool expect_smash;
47 
48 static void __attribute__((noinline))
49 #ifdef _HAVE_CC_INHIBIT_LOOP_TO_LIBCALL
50 __attribute((__optimize__("-fno-tree-loop-distribute-patterns")))
51 #endif
my_strcpy(char * d,char * s)52     my_strcpy(char *d, char *s)
53 {
54     while ((*d++ = *s++));
55 }
56 
smash_array(char * source,char * dest)57 static void __attribute__((noinline)) smash_array(char *source, char *dest)
58 {
59 	char	local[48];
60 
61 	my_strcpy(local, source);
62 	local[0]++;
63 	my_strcpy(dest, local);
64 }
65 
66 void
__stack_chk_fail(void)67 __stack_chk_fail (void)
68 {
69 	if (expect_smash) {
70 #ifdef TINY_STDIO
71 		puts("caught expected stack smash");
72 #endif
73 		_exit(0);
74 	} else {
75 #ifdef TINY_STDIO
76 		puts("caught unexpected stack smash");
77 #endif
78 		_exit(1);
79 	}
80 }
81 
main(void)82 int main(void)
83 {
84 	char	source[64];
85 	char	dest[64];
86 
87 	memset(source, 'x', 15);
88 	source[15] = '\0';
89 	expect_smash = false;
90 	smash_array(source, dest);
91 	expect_smash = false;
92 	printf("short source %s dest %s\n", source, dest);
93 
94 	memset(source, 'x', 63);
95 	source[63] = '\0';
96 	expect_smash = true;
97 	smash_array(source, dest);
98 	expect_smash = false;
99 	printf("missed expected stack smash\n");
100 	return 1;
101 }
102 #else
main(void)103 int main(void)
104 {
105 	printf("stack protector disabled for tests\n");
106 	return 0;
107 }
108 #endif
109