1// SPDX-License-Identifier: GPL-2.0
2#include <linux/init.h>
3#include <linux/kernel.h>
4#include <linux/module.h>
5
6typedef 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
14static void test_ubsan_add_overflow(void)
15{
16 volatile int val = INT_MAX;
17
18 UBSAN_TEST(CONFIG_UBSAN_INTEGER_WRAP);
19 val += 2;
20}
21
22static void test_ubsan_sub_overflow(void)
23{
24 volatile int val = INT_MIN;
25 volatile int val2 = 2;
26
27 UBSAN_TEST(CONFIG_UBSAN_INTEGER_WRAP);
28 val -= val2;
29}
30
31static void test_ubsan_mul_overflow(void)
32{
33 volatile int val = INT_MAX / 2;
34
35 UBSAN_TEST(CONFIG_UBSAN_INTEGER_WRAP);
36 val *= 3;
37}
38
39static void test_ubsan_negate_overflow(void)
40{
41 volatile int val = INT_MIN;
42
43 UBSAN_TEST(CONFIG_UBSAN_INTEGER_WRAP);
44 val = -val;
45}
46
47static 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
56static void test_ubsan_truncate_signed(void)
57{
58 volatile long val = LONG_MAX;
59 volatile int val2 = 0;
60
61 UBSAN_TEST(CONFIG_UBSAN_INTEGER_WRAP);
62 val2 = val;
63}
64
65static void test_ubsan_shift_out_of_bounds(void)
66{
67 volatile int neg = -1, wrap = 4;
68 volatile int val1 = 10;
69 volatile int val2 = INT_MAX;
70
71 UBSAN_TEST(CONFIG_UBSAN_SHIFT, "negative exponent");
72 val1 <<= neg;
73
74 UBSAN_TEST(CONFIG_UBSAN_SHIFT, "left overflow");
75 val2 <<= wrap;
76}
77
78static void test_ubsan_out_of_bounds(void)
79{
80 int i = 4, j = 4, k = -1;
81 volatile struct {
82 char above[4]; /* Protect surrounding memory. */
83 int arr[4];
84 char below[4]; /* Protect surrounding memory. */
85 } data;
86
87 OPTIMIZER_HIDE_VAR(i);
88 OPTIMIZER_HIDE_VAR(j);
89 OPTIMIZER_HIDE_VAR(k);
90
91 UBSAN_TEST(CONFIG_UBSAN_BOUNDS, "above");
92 data.arr[j] = i;
93
94 UBSAN_TEST(CONFIG_UBSAN_BOUNDS, "below");
95 data.arr[k] = i;
96}
97
98enum ubsan_test_enum {
99 UBSAN_TEST_ZERO = 0,
100 UBSAN_TEST_ONE,
101 UBSAN_TEST_MAX,
102};
103
104static void test_ubsan_load_invalid_value(void)
105{
106 volatile char *dst, *src;
107 bool val, val2, *ptr;
108 enum ubsan_test_enum eval, eval2, *eptr;
109 unsigned char c = 0xff;
110
111 UBSAN_TEST(CONFIG_UBSAN_BOOL, "bool");
112 dst = (char *)&val;
113 src = &c;
114 *dst = *src;
115
116 ptr = &val2;
117 val2 = val;
118
119 UBSAN_TEST(CONFIG_UBSAN_ENUM, "enum");
120 dst = (char *)&eval;
121 src = &c;
122 *dst = *src;
123
124 eptr = &eval2;
125 eval2 = eval;
126}
127
128static void test_ubsan_misaligned_access(void)
129{
130 volatile char arr[5] __aligned(4) = {1, 2, 3, 4, 5};
131 volatile int *ptr, val = 6;
132
133 UBSAN_TEST(CONFIG_UBSAN_ALIGNMENT);
134 ptr = (int *)(arr + 1);
135 *ptr = val;
136}
137
138static const test_ubsan_fp test_ubsan_array[] = {
139 test_ubsan_add_overflow,
140 test_ubsan_sub_overflow,
141 test_ubsan_mul_overflow,
142 test_ubsan_negate_overflow,
143 test_ubsan_truncate_signed,
144 test_ubsan_shift_out_of_bounds,
145 test_ubsan_out_of_bounds,
146 test_ubsan_load_invalid_value,
147 test_ubsan_misaligned_access,
148};
149
150/* Excluded because they Oops the module. */
151static __used const test_ubsan_fp skip_ubsan_array[] = {
152 test_ubsan_divrem_overflow,
153};
154
155static int __init test_ubsan_init(void)
156{
157 unsigned int i;
158
159 for (i = 0; i < ARRAY_SIZE(test_ubsan_array); i++)
160 test_ubsan_array[i]();
161
162 return 0;
163}
164module_init(test_ubsan_init);
165
166static void __exit test_ubsan_exit(void)
167{
168 /* do nothing */
169}
170module_exit(test_ubsan_exit);
171
172MODULE_AUTHOR("Jinbum Park <jinb.park7@gmail.com>");
173MODULE_DESCRIPTION("UBSAN unit test");
174MODULE_LICENSE("GPL v2");
175

source code of linux/lib/test_ubsan.c