xref: /linux/lib/test_ubsan.c (revision 666ed8bfd1de3b091cf32ca03b651757dd86cfff)
1 // SPDX-License-Identifier: GPL-2.0
2 #include <linux/init.h>
3 #include <linux/kernel.h>
4 #include <linux/module.h>
5 
6 typedef void(*test_ubsan_fp)(void);
7 
8 static void test_ubsan_add_overflow(void)
9 {
10 	volatile int val = INT_MAX;
11 
12 	val += 2;
13 }
14 
15 static void test_ubsan_sub_overflow(void)
16 {
17 	volatile int val = INT_MIN;
18 	volatile int val2 = 2;
19 
20 	val -= val2;
21 }
22 
23 static void test_ubsan_mul_overflow(void)
24 {
25 	volatile int val = INT_MAX / 2;
26 
27 	val *= 3;
28 }
29 
30 static void test_ubsan_negate_overflow(void)
31 {
32 	volatile int val = INT_MIN;
33 
34 	val = -val;
35 }
36 
37 static void test_ubsan_divrem_overflow(void)
38 {
39 	volatile int val = 16;
40 	volatile int val2 = 0;
41 
42 	val /= val2;
43 }
44 
45 static void test_ubsan_shift_out_of_bounds(void)
46 {
47 	volatile int val = -1;
48 	int val2 = 10;
49 
50 	val2 <<= val;
51 }
52 
53 static void test_ubsan_out_of_bounds(void)
54 {
55 	volatile int i = 4, j = 5;
56 	volatile int arr[4];
57 
58 	arr[j] = i;
59 }
60 
61 static void test_ubsan_load_invalid_value(void)
62 {
63 	volatile char *dst, *src;
64 	bool val, val2, *ptr;
65 	char c = 4;
66 
67 	dst = (char *)&val;
68 	src = &c;
69 	*dst = *src;
70 
71 	ptr = &val2;
72 	val2 = val;
73 }
74 
75 static void test_ubsan_null_ptr_deref(void)
76 {
77 	volatile int *ptr = NULL;
78 	int val;
79 
80 	val = *ptr;
81 }
82 
83 static void test_ubsan_misaligned_access(void)
84 {
85 	volatile char arr[5] __aligned(4) = {1, 2, 3, 4, 5};
86 	volatile int *ptr, val = 6;
87 
88 	ptr = (int *)(arr + 1);
89 	*ptr = val;
90 }
91 
92 static void test_ubsan_object_size_mismatch(void)
93 {
94 	/* "((aligned(8)))" helps this not into be misaligned for ptr-access. */
95 	volatile int val __aligned(8) = 4;
96 	volatile long long *ptr, val2;
97 
98 	ptr = (long long *)&val;
99 	val2 = *ptr;
100 }
101 
102 static const test_ubsan_fp test_ubsan_array[] = {
103 	test_ubsan_add_overflow,
104 	test_ubsan_sub_overflow,
105 	test_ubsan_mul_overflow,
106 	test_ubsan_negate_overflow,
107 	test_ubsan_divrem_overflow,
108 	test_ubsan_shift_out_of_bounds,
109 	test_ubsan_out_of_bounds,
110 	test_ubsan_load_invalid_value,
111 	//test_ubsan_null_ptr_deref, /* exclude it because there is a crash */
112 	test_ubsan_misaligned_access,
113 	test_ubsan_object_size_mismatch,
114 };
115 
116 static int __init test_ubsan_init(void)
117 {
118 	unsigned int i;
119 
120 	for (i = 0; i < ARRAY_SIZE(test_ubsan_array); i++)
121 		test_ubsan_array[i]();
122 
123 	(void)test_ubsan_null_ptr_deref; /* to avoid unsed-function warning */
124 	return 0;
125 }
126 module_init(test_ubsan_init);
127 
128 static void __exit test_ubsan_exit(void)
129 {
130 	/* do nothing */
131 }
132 module_exit(test_ubsan_exit);
133 
134 MODULE_AUTHOR("Jinbum Park <jinb.park7@gmail.com>");
135 MODULE_LICENSE("GPL v2");
136