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 #define UBSAN_TEST(config, ...) do { \
9 pr_info("%s " __VA_ARGS__ "%s(%s=%s)\n", __func__, \
10 sizeof(" " __VA_ARGS__) > 2 ? " " : "", \
11 #config, IS_ENABLED(config) ? "y" : "n"); \
12 } while (0)
13
14 static void test_ubsan_add_overflow(void)
15 {
16 volatile int val = INT_MAX;
17
18 UBSAN_TEST(CONFIG_UBSAN_SIGNED_WRAP);
19 val += 2;
20 }
21
22 static void test_ubsan_sub_overflow(void)
23 {
24 volatile int val = INT_MIN;
25 volatile int val2 = 2;
26
27 UBSAN_TEST(CONFIG_UBSAN_SIGNED_WRAP);
28 val -= val2;
29 }
30
31 static void test_ubsan_mul_overflow(void)
32 {
33 volatile int val = INT_MAX / 2;
34
35 UBSAN_TEST(CONFIG_UBSAN_SIGNED_WRAP);
36 val *= 3;
37 }
38
39 static void test_ubsan_negate_overflow(void)
40 {
41 volatile int val = INT_MIN;
42
43 UBSAN_TEST(CONFIG_UBSAN_SIGNED_WRAP);
44 val = -val;
45 }
46
47 static void test_ubsan_divrem_overflow(void)
48 {
49 volatile int val = 16;
50 volatile int val2 = 0;
51
52 UBSAN_TEST(CONFIG_UBSAN_DIV_ZERO);
53 val /= val2;
54 }
55
56 static void test_ubsan_shift_out_of_bounds(void)
57 {
58 volatile int neg = -1, wrap = 4;
59 volatile int val1 = 10;
60 volatile int val2 = INT_MAX;
61
62 UBSAN_TEST(CONFIG_UBSAN_SHIFT, "negative exponent");
63 val1 <<= neg;
64
65 UBSAN_TEST(CONFIG_UBSAN_SHIFT, "left overflow");
66 val2 <<= wrap;
67 }
68
69 static void test_ubsan_out_of_bounds(void)
70 {
71 volatile int i = 4, j = 5, k = -1;
72 volatile char above[4] = { }; /* Protect surrounding memory. */
73 volatile int arr[4];
74 volatile char below[4] = { }; /* Protect surrounding memory. */
75
76 above[0] = below[0];
77
78 UBSAN_TEST(CONFIG_UBSAN_BOUNDS, "above");
79 arr[j] = i;
80
81 UBSAN_TEST(CONFIG_UBSAN_BOUNDS, "below");
82 arr[k] = i;
83 }
84
85 enum ubsan_test_enum {
86 UBSAN_TEST_ZERO = 0,
87 UBSAN_TEST_ONE,
88 UBSAN_TEST_MAX,
89 };
90
91 static void test_ubsan_load_invalid_value(void)
92 {
93 volatile char *dst, *src;
94 bool val, val2, *ptr;
95 enum ubsan_test_enum eval, eval2, *eptr;
96 unsigned char c = 0xff;
97
98 UBSAN_TEST(CONFIG_UBSAN_BOOL, "bool");
99 dst = (char *)&val;
100 src = &c;
101 *dst = *src;
102
103 ptr = &val2;
104 val2 = val;
105
106 UBSAN_TEST(CONFIG_UBSAN_ENUM, "enum");
107 dst = (char *)&eval;
108 src = &c;
109 *dst = *src;
110
111 eptr = &eval2;
112 eval2 = eval;
113 }
114
115 static void test_ubsan_misaligned_access(void)
116 {
117 volatile char arr[5] __aligned(4) = {1, 2, 3, 4, 5};
118 volatile int *ptr, val = 6;
119
120 UBSAN_TEST(CONFIG_UBSAN_ALIGNMENT);
121 ptr = (int *)(arr + 1);
122 *ptr = val;
123 }
124
125 static const test_ubsan_fp test_ubsan_array[] = {
126 test_ubsan_add_overflow,
127 test_ubsan_sub_overflow,
128 test_ubsan_mul_overflow,
129 test_ubsan_negate_overflow,
130 test_ubsan_shift_out_of_bounds,
131 test_ubsan_out_of_bounds,
132 test_ubsan_load_invalid_value,
133 test_ubsan_misaligned_access,
134 };
135
136 /* Excluded because they Oops the module. */
137 static __used const test_ubsan_fp skip_ubsan_array[] = {
138 test_ubsan_divrem_overflow,
139 };
140
141 static int __init test_ubsan_init(void)
142 {
143 unsigned int i;
144
145 for (i = 0; i < ARRAY_SIZE(test_ubsan_array); i++)
146 test_ubsan_array[i]();
147
148 return 0;
149 }
150 module_init(test_ubsan_init);
151
152 static void __exit test_ubsan_exit(void)
153 {
154 /* do nothing */
155 }
156 module_exit(test_ubsan_exit);
157
158 MODULE_AUTHOR("Jinbum Park <jinb.park7@gmail.com>");
159 MODULE_DESCRIPTION("UBSAN unit test");
160 MODULE_LICENSE("GPL v2");
161
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