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_divrem_overflow(void)
15{
16 volatile int val = 16;
17 volatile int val2 = 0;
18
19 UBSAN_TEST(CONFIG_UBSAN_DIV_ZERO);
20 val /= val2;
21}
22
23static void test_ubsan_shift_out_of_bounds(void)
24{
25 volatile int neg = -1, wrap = 4;
26 int val1 = 10;
27 int val2 = INT_MAX;
28
29 UBSAN_TEST(CONFIG_UBSAN_SHIFT, "negative exponent");
30 val1 <<= neg;
31
32 UBSAN_TEST(CONFIG_UBSAN_SHIFT, "left overflow");
33 val2 <<= wrap;
34}
35
36static void test_ubsan_out_of_bounds(void)
37{
38 volatile int i = 4, j = 5, k = -1;
39 volatile char above[4] = { }; /* Protect surrounding memory. */
40 volatile int arr[4];
41 volatile char below[4] = { }; /* Protect surrounding memory. */
42
43 above[0] = below[0];
44
45 UBSAN_TEST(CONFIG_UBSAN_BOUNDS, "above");
46 arr[j] = i;
47
48 UBSAN_TEST(CONFIG_UBSAN_BOUNDS, "below");
49 arr[k] = i;
50}
51
52enum ubsan_test_enum {
53 UBSAN_TEST_ZERO = 0,
54 UBSAN_TEST_ONE,
55 UBSAN_TEST_MAX,
56};
57
58static void test_ubsan_load_invalid_value(void)
59{
60 volatile char *dst, *src;
61 bool val, val2, *ptr;
62 enum ubsan_test_enum eval, eval2, *eptr;
63 unsigned char c = 0xff;
64
65 UBSAN_TEST(CONFIG_UBSAN_BOOL, "bool");
66 dst = (char *)&val;
67 src = &c;
68 *dst = *src;
69
70 ptr = &val2;
71 val2 = val;
72
73 UBSAN_TEST(CONFIG_UBSAN_ENUM, "enum");
74 dst = (char *)&eval;
75 src = &c;
76 *dst = *src;
77
78 eptr = &eval2;
79 eval2 = eval;
80}
81
82static void test_ubsan_misaligned_access(void)
83{
84 volatile char arr[5] __aligned(4) = {1, 2, 3, 4, 5};
85 volatile int *ptr, val = 6;
86
87 UBSAN_TEST(CONFIG_UBSAN_ALIGNMENT);
88 ptr = (int *)(arr + 1);
89 *ptr = val;
90}
91
92static const test_ubsan_fp test_ubsan_array[] = {
93 test_ubsan_shift_out_of_bounds,
94 test_ubsan_out_of_bounds,
95 test_ubsan_load_invalid_value,
96 test_ubsan_misaligned_access,
97};
98
99/* Excluded because they Oops the module. */
100static const test_ubsan_fp skip_ubsan_array[] = {
101 test_ubsan_divrem_overflow,
102};
103
104static int __init test_ubsan_init(void)
105{
106 unsigned int i;
107
108 for (i = 0; i < ARRAY_SIZE(test_ubsan_array); i++)
109 test_ubsan_array[i]();
110
111 return 0;
112}
113module_init(test_ubsan_init);
114
115static void __exit test_ubsan_exit(void)
116{
117 /* do nothing */
118}
119module_exit(test_ubsan_exit);
120
121MODULE_AUTHOR("Jinbum Park <jinb.park7@gmail.com>");
122MODULE_LICENSE("GPL v2");
123

source code of linux/lib/test_ubsan.c