summaryrefslogtreecommitdiffstats
path: root/lib/fortify_kunit.c
blob: c8c33cbaae9ec9d17bf5f7aef590be20943ce0b1 (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
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
// SPDX-License-Identifier: GPL-2.0
/*
 * Runtime test cases for CONFIG_FORTIFY_SOURCE that aren't expected to
 * Oops the kernel on success. (For those, see drivers/misc/lkdtm/fortify.c)
 *
 * For corner cases with UBSAN, try testing with:
 *
 * ./tools/testing/kunit/kunit.py run --arch=x86_64 \
 *	--kconfig_add CONFIG_FORTIFY_SOURCE=y \
 *	--kconfig_add CONFIG_UBSAN=y \
 *	--kconfig_add CONFIG_UBSAN_TRAP=y \
 *	--kconfig_add CONFIG_UBSAN_BOUNDS=y \
 *	--kconfig_add CONFIG_UBSAN_LOCAL_BOUNDS=y \
 *	--make_options LLVM=1 fortify
 */
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <kunit/test.h>
#include <linux/device.h>
#include <linux/slab.h>
#include <linux/string.h>
#include <linux/vmalloc.h>

static const char array_of_10[] = "this is 10";
static const char *ptr_of_11 = "this is 11!";
static char array_unknown[] = "compiler thinks I might change";

static void known_sizes_test(struct kunit *test)
{
	KUNIT_EXPECT_EQ(test, __compiletime_strlen("88888888"), 8);
	KUNIT_EXPECT_EQ(test, __compiletime_strlen(array_of_10), 10);
	KUNIT_EXPECT_EQ(test, __compiletime_strlen(ptr_of_11), 11);

	KUNIT_EXPECT_EQ(test, __compiletime_strlen(array_unknown), SIZE_MAX);
	/* Externally defined and dynamically sized string pointer: */
	KUNIT_EXPECT_EQ(test, __compiletime_strlen(test->name), SIZE_MAX);
}

/* This is volatile so the optimizer can't perform DCE below. */
static volatile int pick;

/* Not inline to keep optimizer from figuring out which string we want. */
static noinline size_t want_minus_one(int pick)
{
	const char *str;

	switch (pick) {
	case 1:
		str = "4444";
		break;
	case 2:
		str = "333";
		break;
	default:
		str = "1";
		break;
	}
	return __compiletime_strlen(str);
}

static void control_flow_split_test(struct kunit *test)
{
	KUNIT_EXPECT_EQ(test, want_minus_one(pick), SIZE_MAX);
}

#define KUNIT_EXPECT_BOS(test, p, expected, name)			\
	KUNIT_EXPECT_EQ_MSG(test, __builtin_object_size(p, 1),		\
		expected,						\
		"__alloc_size() not working with __bos on " name "\n")

#if !__has_builtin(__builtin_dynamic_object_size)
#define KUNIT_EXPECT_BDOS(test, p, expected, name)			\
	/* Silence "unused variable 'expected'" warning. */		\
	KUNIT_EXPECT_EQ(test, expected, expected)
#else
#define KUNIT_EXPECT_BDOS(test, p, expected, name)			\
	KUNIT_EXPECT_EQ_MSG(test, __builtin_dynamic_object_size(p, 1),	\
		expected,						\
		"__alloc_size() not working with __bdos on " name "\n")
#endif

/* If the execpted size is a constant value, __bos can see it. */
#define check_const(_expected, alloc, free)		do {		\
	size_t expected = (_expected);					\
	void *p = alloc;						\
	KUNIT_EXPECT_TRUE_MSG(test, p != NULL, #alloc " failed?!\n");	\
	KUNIT_EXPECT_BOS(test, p, expected, #alloc);			\
	KUNIT_EXPECT_BDOS(test, p, expected, #alloc);			\
	free;								\
} while (0)

/* If the execpted size is NOT a constant value, __bos CANNOT see it. */
#define check_dynamic(_expected, alloc, free)		do {		\
	size_t expected = (_expected);					\
	void *p = alloc;						\
	KUNIT_EXPECT_TRUE_MSG(test, p != NULL, #alloc " failed?!\n");	\
	KUNIT_EXPECT_BOS(test, p, SIZE_MAX, #alloc);			\
	KUNIT_EXPECT_BDOS(test, p, expected, #alloc);			\
	free;								\
} while (0)

/* Assortment of constant-value kinda-edge cases. */
#define CONST_TEST_BODY(TEST_alloc)	do {				\
	/* Special-case vmalloc()-family to skip 0-sized allocs. */	\
	if (strcmp(#TEST_alloc, "TEST_vmalloc") != 0)			\
		TEST_alloc(check_const, 0, 0);				\
	TEST_alloc(check_const, 1, 1);					\
	TEST_alloc(check_const, 128, 128);				\
	TEST_alloc(check_const, 1023, 1023);				\
	TEST_alloc(check_const, 1025, 1025);				\
	TEST_alloc(check_const, 4096, 4096);				\
	TEST_alloc(check_const, 4097, 4097);				\
} while (0)

static volatile size_t zero_size;
static volatile size_t unknown_size = 50;

#if !__has_builtin(__builtin_dynamic_object_size)
#define DYNAMIC_TEST_BODY(TEST_alloc)					\
	kunit_skip(test, "Compiler is missing __builtin_dynamic_object_size() support\n")
#else
#define DYNAMIC_TEST_BODY(TEST_alloc)	do {				\
	size_t size = unknown_size;					\
									\
	/*								\
	 * Expected size is "size" in each test, before it is then	\
	 * internally incremented in each test.	Requires we disable	\
	 * -Wunsequenced.						\
	 */								\
	TEST_alloc(check_dynamic, size, size++);			\
	/* Make sure incrementing actually happened. */			\
	KUNIT_EXPECT_NE(test, size, unknown_size);			\
} while (0)
#endif

#define DEFINE_ALLOC_SIZE_TEST_PAIR(allocator)				\
static void alloc_size_##allocator##_const_test(struct kunit *test)	\
{									\
	CONST_TEST_BODY(TEST_##allocator);				\
}									\
static void alloc_size_##allocator##_dynamic_test(struct kunit *test)	\
{									\
	DYNAMIC_TEST_BODY(TEST_##allocator);				\
}

#define TEST_kmalloc(checker, expected_size, alloc_size)	do {	\
	gfp_t gfp = GFP_KERNEL | __GFP_NOWARN;				\
	void *orig;							\
	size_t len;							\
									\
	checker(expected_size, kmalloc(alloc_size, gfp),		\
		kfree(p));						\
	checker(expected_size,						\
		kmalloc_node(alloc_size, gfp, NUMA_NO_NODE),		\
		kfree(p));						\
	checker(expected_size, kzalloc(alloc_size, gfp),		\
		kfree(p));						\
	checker(expected_size,						\
		kzalloc_node(alloc_size, gfp, NUMA_NO_NODE),		\
		kfree(p));						\
	checker(expected_size, kcalloc(1, alloc_size, gfp),		\
		kfree(p));						\
	checker(expected_size, kcalloc(alloc_size, 1, gfp),		\
		kfree(p));						\
	checker(expected_size,						\
		kcalloc_node(1, alloc_size, gfp, NUMA_NO_NODE),		\
		kfree(p));						\
	checker(expected_size,						\
		kcalloc_node(alloc_size, 1, gfp, NUMA_NO_NODE),		\
		kfree(p));						\
	checker(expected_size, kmalloc_array(1, alloc_size, gfp),	\
		kfree(p));						\
	checker(expected_size, kmalloc_array(alloc_size, 1, gfp),	\
		kfree(p));						\
	checker(expected_size,						\
		kmalloc_array_node(1, alloc_size, gfp, NUMA_NO_NODE),	\
		kfree(p));						\
	checker(expected_size,						\
		kmalloc_array_node(alloc_size, 1, gfp, NUMA_NO_NODE),	\
		kfree(p));						\
	checker(expected_size, __kmalloc(alloc_size, gfp),		\
		kfree(p));						\
	checker(expected_size,						\
		__kmalloc_node(alloc_size, gfp, NUMA_NO_NODE),		\
		kfree(p));						\
									\
	orig = kmalloc(alloc_size, gfp);				\
	KUNIT_EXPECT_TRUE(test, orig != NULL);				\
	checker((expected_size) * 2,					\
		krealloc(orig, (alloc_size) * 2, gfp),			\
		kfree(p));						\
	orig = kmalloc(alloc_size, gfp);				\
	KUNIT_EXPECT_TRUE(test, orig != NULL);				\
	checker((expected_size) * 2,					\
		krealloc_array(orig, 1, (alloc_size) * 2, gfp),		\
		kfree(p));						\
	orig = kmalloc(alloc_size, gfp);				\
	KUNIT_EXPECT_TRUE(test, orig != NULL);				\
	checker((expected_size) * 2,					\
		krealloc_array(orig, (alloc_size) * 2, 1, gfp),		\
		kfree(p));						\
									\
	len = 11;							\
	/* Using memdup() with fixed size, so force unknown length. */	\
	if (!__builtin_constant_p(expected_size))			\
		len += zero_size;					\
	checker(len, kmemdup("hello there", len, gfp), kfree(p));	\
} while (0)
DEFINE_ALLOC_SIZE_TEST_PAIR(kmalloc)

/* Sizes are in pages, not bytes. */
#define TEST_vmalloc(checker, expected_pages, alloc_pages)	do {	\
	gfp_t gfp = GFP_KERNEL | __GFP_NOWARN;				\
	checker((expected_pages) * PAGE_SIZE,				\
		vmalloc((alloc_pages) * PAGE_SIZE),	   vfree(p));	\
	checker((expected_pages) * PAGE_SIZE,				\
		vzalloc((alloc_pages) * PAGE_SIZE),	   vfree(p));	\
	checker((expected_pages) * PAGE_SIZE,				\
		__vmalloc((alloc_pages) * PAGE_SIZE, gfp), vfree(p));	\
} while (0)
DEFINE_ALLOC_SIZE_TEST_PAIR(vmalloc)

/* Sizes are in pages (and open-coded for side-effects), not bytes. */
#define TEST_kvmalloc(checker, expected_pages, alloc_pages)	do {	\
	gfp_t gfp = GFP_KERNEL | __GFP_NOWARN;				\
	size_t prev_size;						\
	void *orig;							\
									\
	checker((expected_pages) * PAGE_SIZE,				\
		kvmalloc((alloc_pages) * PAGE_SIZE, gfp),		\
		vfree(p));						\
	checker((expected_pages) * PAGE_SIZE,				\
		kvmalloc_node((alloc_pages) * PAGE_SIZE, gfp, NUMA_NO_NODE), \
		vfree(p));						\
	checker((expected_pages) * PAGE_SIZE,				\
		kvzalloc((alloc_pages) * PAGE_SIZE, gfp),		\
		vfree(p));						\
	checker((expected_pages) * PAGE_SIZE,				\
		kvzalloc_node((alloc_pages) * PAGE_SIZE, gfp, NUMA_NO_NODE), \
		vfree(p));						\
	checker((expected_pages) * PAGE_SIZE,				\
		kvcalloc(1, (alloc_pages) * PAGE_SIZE, gfp),		\
		vfree(p));						\
	checker((expected_pages) * PAGE_SIZE,				\
		kvcalloc((alloc_pages) * PAGE_SIZE, 1, gfp),		\
		vfree(p));						\
	checker((expected_pages) * PAGE_SIZE,				\
		kvmalloc_array(1, (alloc_pages) * PAGE_SIZE, gfp),	\
		vfree(p));						\
	checker((expected_pages) * PAGE_SIZE,				\
		kvmalloc_array((alloc_pages) * PAGE_SIZE, 1, gfp),	\
		vfree(p));						\
									\
	prev_size = (expected_pages) * PAGE_SIZE;			\
	orig = kvmalloc(prev_size, gfp);				\
	KUNIT_EXPECT_TRUE(test, orig != NULL);				\
	checker(((expected_pages) * PAGE_SIZE) * 2,			\
		kvrealloc(orig, prev_size,				\
			  ((alloc_pages) * PAGE_SIZE) * 2, gfp),	\
		kvfree(p));						\
} while (0)
DEFINE_ALLOC_SIZE_TEST_PAIR(kvmalloc)

#define TEST_devm_kmalloc(checker, expected_size, alloc_size)	do {	\
	gfp_t gfp = GFP_KERNEL | __GFP_NOWARN;				\
	const char dev_name[] = "fortify-test";				\
	struct device *dev;						\
	void *orig;							\
	size_t len;							\
									\
	/* Create dummy device for devm_kmalloc()-family tests. */	\
	dev = root_device_register(dev_name);				\
	KUNIT_ASSERT_FALSE_MSG(test, IS_ERR(dev),			\
			       "Cannot register test device\n");	\
									\
	checker(expected_size, devm_kmalloc(dev, alloc_size, gfp),	\
		devm_kfree(dev, p));					\
	checker(expected_size, devm_kzalloc(dev, alloc_size, gfp),	\
		devm_kfree(dev, p));					\
	checker(expected_size,						\
		devm_kmalloc_array(dev, 1, alloc_size, gfp),		\
		devm_kfree(dev, p));					\
	checker(expected_size,						\
		devm_kmalloc_array(dev, alloc_size, 1, gfp),		\
		devm_kfree(dev, p));					\
	checker(expected_size,						\
		devm_kcalloc(dev, 1, alloc_size, gfp),			\
		devm_kfree(dev, p));					\
	checker(expected_size,						\
		devm_kcalloc(dev, alloc_size, 1, gfp),			\
		devm_kfree(dev, p));					\
									\
	orig = devm_kmalloc(dev, alloc_size, gfp);			\
	KUNIT_EXPECT_TRUE(test, orig != NULL);				\
	checker((expected_size) * 2,					\
		devm_krealloc(dev, orig, (alloc_size) * 2, gfp),	\
		devm_kfree(dev, p));					\
									\
	len = 4;							\
	/* Using memdup() with fixed size, so force unknown length. */	\
	if (!__builtin_constant_p(expected_size))			\
		len += zero_size;					\
	checker(len, devm_kmemdup(dev, "Ohai", len, gfp),		\
		devm_kfree(dev, p));					\
									\
	device_unregister(dev);						\
} while (0)
DEFINE_ALLOC_SIZE_TEST_PAIR(devm_kmalloc)

static struct kunit_case fortify_test_cases[] = {
	KUNIT_CASE(known_sizes_test),
	KUNIT_CASE(control_flow_split_test),
	KUNIT_CASE(alloc_size_kmalloc_const_test),
	KUNIT_CASE(alloc_size_kmalloc_dynamic_test),
	KUNIT_CASE(alloc_size_vmalloc_const_test),
	KUNIT_CASE(alloc_size_vmalloc_dynamic_test),
	KUNIT_CASE(alloc_size_kvmalloc_const_test),
	KUNIT_CASE(alloc_size_kvmalloc_dynamic_test),
	KUNIT_CASE(alloc_size_devm_kmalloc_const_test),
	KUNIT_CASE(alloc_size_devm_kmalloc_dynamic_test),
	{}
};

static struct kunit_suite fortify_test_suite = {
	.name = "fortify",
	.test_cases = fortify_test_cases,
};

kunit_test_suite(fortify_test_suite);

MODULE_LICENSE("GPL");