summaryrefslogtreecommitdiff
path: root/lib/test_ubsan.c
blob: c288df9372ede1cbda1371ae92e20a25ae9ebe91 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
// SPDX-License-Identifier: GPL-2.0
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>

typedef void(*test_ubsan_fp)(void);

#define UBSAN_TEST(config, ...)	do {					\
		pr_info("%s " __VA_ARGS__ "%s(%s=%s)\n", __func__,	\
			sizeof(" " __VA_ARGS__) > 2 ? " " : "",		\
			#config, IS_ENABLED(config) ? "y" : "n");	\
	} while (0)

static void test_ubsan_add_overflow(void)
{
	volatile int val = INT_MAX;

	UBSAN_TEST(CONFIG_UBSAN_SIGNED_WRAP);
	val += 2;
}

static void test_ubsan_sub_overflow(void)
{
	volatile int val = INT_MIN;
	volatile int val2 = 2;

	UBSAN_TEST(CONFIG_UBSAN_SIGNED_WRAP);
	val -= val2;
}

static void test_ubsan_mul_overflow(void)
{
	volatile int val = INT_MAX / 2;

	UBSAN_TEST(CONFIG_UBSAN_SIGNED_WRAP);
	val *= 3;
}

static void test_ubsan_negate_overflow(void)
{
	volatile int val = INT_MIN;

	UBSAN_TEST(CONFIG_UBSAN_SIGNED_WRAP);
	val = -val;
}

static void test_ubsan_divrem_overflow(void)
{
	volatile int val = 16;
	volatile int val2 = 0;

	UBSAN_TEST(CONFIG_UBSAN_DIV_ZERO);
	val /= val2;
}

static void test_ubsan_shift_out_of_bounds(void)
{
	volatile int neg = -1, wrap = 4;
	volatile int val1 = 10;
	volatile int val2 = INT_MAX;

	UBSAN_TEST(CONFIG_UBSAN_SHIFT, "negative exponent");
	val1 <<= neg;

	UBSAN_TEST(CONFIG_UBSAN_SHIFT, "left overflow");
	val2 <<= wrap;
}

static void test_ubsan_out_of_bounds(void)
{
	volatile int i = 4, j = 5, k = -1;
	volatile char above[4] = { }; /* Protect surrounding memory. */
	volatile int arr[4];
	volatile char below[4] = { }; /* Protect surrounding memory. */

	above[0] = below[0];

	UBSAN_TEST(CONFIG_UBSAN_BOUNDS, "above");
	arr[j] = i;

	UBSAN_TEST(CONFIG_UBSAN_BOUNDS, "below");
	arr[k] = i;
}

enum ubsan_test_enum {
	UBSAN_TEST_ZERO = 0,
	UBSAN_TEST_ONE,
	UBSAN_TEST_MAX,
};

static void test_ubsan_load_invalid_value(void)
{
	volatile char *dst, *src;
	bool val, val2, *ptr;
	enum ubsan_test_enum eval, eval2, *eptr;
	unsigned char c = 0xff;

	UBSAN_TEST(CONFIG_UBSAN_BOOL, "bool");
	dst = (char *)&val;
	src = &c;
	*dst = *src;

	ptr = &val2;
	val2 = val;

	UBSAN_TEST(CONFIG_UBSAN_ENUM, "enum");
	dst = (char *)&eval;
	src = &c;
	*dst = *src;

	eptr = &eval2;
	eval2 = eval;
}

static void test_ubsan_misaligned_access(void)
{
	volatile char arr[5] __aligned(4) = {1, 2, 3, 4, 5};
	volatile int *ptr, val = 6;

	UBSAN_TEST(CONFIG_UBSAN_ALIGNMENT);
	ptr = (int *)(arr + 1);
	*ptr = val;
}

static const test_ubsan_fp test_ubsan_array[] = {
	test_ubsan_add_overflow,
	test_ubsan_sub_overflow,
	test_ubsan_mul_overflow,
	test_ubsan_negate_overflow,
	test_ubsan_shift_out_of_bounds,
	test_ubsan_out_of_bounds,
	test_ubsan_load_invalid_value,
	test_ubsan_misaligned_access,
};

/* Excluded because they Oops the module. */
static __used const test_ubsan_fp skip_ubsan_array[] = {
	test_ubsan_divrem_overflow,
};

static int __init test_ubsan_init(void)
{
	unsigned int i;

	for (i = 0; i < ARRAY_SIZE(test_ubsan_array); i++)
		test_ubsan_array[i]();

	return 0;
}
module_init(test_ubsan_init);

static void __exit test_ubsan_exit(void)
{
	/* do nothing */
}
module_exit(test_ubsan_exit);

MODULE_AUTHOR("Jinbum Park <jinb.park7@gmail.com>");
MODULE_LICENSE("GPL v2");