xref: /linux/lib/memcpy_kunit.c (revision 31354121bf03dac6498a4236928a38490745d601)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Test cases for memcpy(), memmove(), and memset().
4  */
5 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
6 
7 #include <kunit/test.h>
8 #include <linux/device.h>
9 #include <linux/init.h>
10 #include <linux/kernel.h>
11 #include <linux/mm.h>
12 #include <linux/module.h>
13 #include <linux/overflow.h>
14 #include <linux/slab.h>
15 #include <linux/types.h>
16 #include <linux/vmalloc.h>
17 
18 struct some_bytes {
19 	union {
20 		u8 data[32];
21 		struct {
22 			u32 one;
23 			u16 two;
24 			u8  three;
25 			/* 1 byte hole */
26 			u32 four[4];
27 		};
28 	};
29 };
30 
31 #define check(instance, v) do {	\
32 	BUILD_BUG_ON(sizeof(instance.data) != 32);	\
33 	for (size_t i = 0; i < sizeof(instance.data); i++) {	\
34 		KUNIT_ASSERT_EQ_MSG(test, instance.data[i], v, \
35 			"line %d: '%s' not initialized to 0x%02x @ %d (saw 0x%02x)\n", \
36 			__LINE__, #instance, v, i, instance.data[i]);	\
37 	}	\
38 } while (0)
39 
40 #define compare(name, one, two) do { \
41 	BUILD_BUG_ON(sizeof(one) != sizeof(two)); \
42 	for (size_t i = 0; i < sizeof(one); i++) {	\
43 		KUNIT_EXPECT_EQ_MSG(test, one.data[i], two.data[i], \
44 			"line %d: %s.data[%d] (0x%02x) != %s.data[%d] (0x%02x)\n", \
45 			__LINE__, #one, i, one.data[i], #two, i, two.data[i]); \
46 	}	\
47 	kunit_info(test, "ok: " TEST_OP "() " name "\n");	\
48 } while (0)
49 
50 static void memcpy_test(struct kunit *test)
51 {
52 #define TEST_OP "memcpy"
53 	struct some_bytes control = {
54 		.data = { 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20,
55 			  0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20,
56 			  0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20,
57 			  0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20,
58 			},
59 	};
60 	struct some_bytes zero = { };
61 	struct some_bytes middle = {
62 		.data = { 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20,
63 			  0x20, 0x20, 0x20, 0x20, 0x00, 0x00, 0x00, 0x00,
64 			  0x00, 0x00, 0x00, 0x20, 0x20, 0x20, 0x20, 0x20,
65 			  0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20,
66 			},
67 	};
68 	struct some_bytes three = {
69 		.data = { 0x00, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20,
70 			  0x20, 0x00, 0x00, 0x20, 0x20, 0x20, 0x20, 0x20,
71 			  0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20,
72 			  0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20,
73 			},
74 	};
75 	struct some_bytes dest = { };
76 	int count;
77 	u8 *ptr;
78 
79 	/* Verify static initializers. */
80 	check(control, 0x20);
81 	check(zero, 0);
82 	compare("static initializers", dest, zero);
83 
84 	/* Verify assignment. */
85 	dest = control;
86 	compare("direct assignment", dest, control);
87 
88 	/* Verify complete overwrite. */
89 	memcpy(dest.data, zero.data, sizeof(dest.data));
90 	compare("complete overwrite", dest, zero);
91 
92 	/* Verify middle overwrite. */
93 	dest = control;
94 	memcpy(dest.data + 12, zero.data, 7);
95 	compare("middle overwrite", dest, middle);
96 
97 	/* Verify argument side-effects aren't repeated. */
98 	dest = control;
99 	ptr = dest.data;
100 	count = 1;
101 	memcpy(ptr++, zero.data, count++);
102 	ptr += 8;
103 	memcpy(ptr++, zero.data, count++);
104 	compare("argument side-effects", dest, three);
105 #undef TEST_OP
106 }
107 
108 static void memmove_test(struct kunit *test)
109 {
110 #define TEST_OP "memmove"
111 	struct some_bytes control = {
112 		.data = { 0x99, 0x99, 0x99, 0x99, 0x99, 0x99, 0x99, 0x99,
113 			  0x99, 0x99, 0x99, 0x99, 0x99, 0x99, 0x99, 0x99,
114 			  0x99, 0x99, 0x99, 0x99, 0x99, 0x99, 0x99, 0x99,
115 			  0x99, 0x99, 0x99, 0x99, 0x99, 0x99, 0x99, 0x99,
116 			},
117 	};
118 	struct some_bytes zero = { };
119 	struct some_bytes middle = {
120 		.data = { 0x99, 0x99, 0x99, 0x99, 0x99, 0x99, 0x99, 0x99,
121 			  0x99, 0x99, 0x99, 0x99, 0x00, 0x00, 0x00, 0x00,
122 			  0x00, 0x00, 0x00, 0x99, 0x99, 0x99, 0x99, 0x99,
123 			  0x99, 0x99, 0x99, 0x99, 0x99, 0x99, 0x99, 0x99,
124 			},
125 	};
126 	struct some_bytes five = {
127 		.data = { 0x00, 0x00, 0x99, 0x99, 0x99, 0x99, 0x99, 0x99,
128 			  0x99, 0x99, 0x00, 0x00, 0x00, 0x99, 0x99, 0x99,
129 			  0x99, 0x99, 0x99, 0x99, 0x99, 0x99, 0x99, 0x99,
130 			  0x99, 0x99, 0x99, 0x99, 0x99, 0x99, 0x99, 0x99,
131 			},
132 	};
133 	struct some_bytes overlap = {
134 		.data = { 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
135 			  0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E, 0x0F,
136 			  0x99, 0x99, 0x99, 0x99, 0x99, 0x99, 0x99, 0x99,
137 			  0x99, 0x99, 0x99, 0x99, 0x99, 0x99, 0x99, 0x99,
138 			},
139 	};
140 	struct some_bytes overlap_expected = {
141 		.data = { 0x00, 0x01, 0x00, 0x01, 0x02, 0x03, 0x04, 0x07,
142 			  0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E, 0x0F,
143 			  0x99, 0x99, 0x99, 0x99, 0x99, 0x99, 0x99, 0x99,
144 			  0x99, 0x99, 0x99, 0x99, 0x99, 0x99, 0x99, 0x99,
145 			},
146 	};
147 	struct some_bytes dest = { };
148 	int count;
149 	u8 *ptr;
150 
151 	/* Verify static initializers. */
152 	check(control, 0x99);
153 	check(zero, 0);
154 	compare("static initializers", zero, dest);
155 
156 	/* Verify assignment. */
157 	dest = control;
158 	compare("direct assignment", dest, control);
159 
160 	/* Verify complete overwrite. */
161 	memmove(dest.data, zero.data, sizeof(dest.data));
162 	compare("complete overwrite", dest, zero);
163 
164 	/* Verify middle overwrite. */
165 	dest = control;
166 	memmove(dest.data + 12, zero.data, 7);
167 	compare("middle overwrite", dest, middle);
168 
169 	/* Verify argument side-effects aren't repeated. */
170 	dest = control;
171 	ptr = dest.data;
172 	count = 2;
173 	memmove(ptr++, zero.data, count++);
174 	ptr += 9;
175 	memmove(ptr++, zero.data, count++);
176 	compare("argument side-effects", dest, five);
177 
178 	/* Verify overlapping overwrite is correct. */
179 	ptr = &overlap.data[2];
180 	memmove(ptr, overlap.data, 5);
181 	compare("overlapping write", overlap, overlap_expected);
182 #undef TEST_OP
183 }
184 
185 static void memset_test(struct kunit *test)
186 {
187 #define TEST_OP "memset"
188 	struct some_bytes control = {
189 		.data = { 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30,
190 			  0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30,
191 			  0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30,
192 			  0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30,
193 			},
194 	};
195 	struct some_bytes complete = {
196 		.data = { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
197 			  0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
198 			  0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
199 			  0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
200 			},
201 	};
202 	struct some_bytes middle = {
203 		.data = { 0x30, 0x30, 0x30, 0x30, 0x31, 0x31, 0x31, 0x31,
204 			  0x31, 0x31, 0x31, 0x31, 0x31, 0x31, 0x31, 0x31,
205 			  0x31, 0x31, 0x31, 0x31, 0x30, 0x30, 0x30, 0x30,
206 			  0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30,
207 			},
208 	};
209 	struct some_bytes three = {
210 		.data = { 0x60, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30,
211 			  0x30, 0x61, 0x61, 0x30, 0x30, 0x30, 0x30, 0x30,
212 			  0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30,
213 			  0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30,
214 			},
215 	};
216 	struct some_bytes after = {
217 		.data = { 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x72,
218 			  0x72, 0x72, 0x72, 0x72, 0x72, 0x72, 0x72, 0x72,
219 			  0x72, 0x72, 0x72, 0x72, 0x72, 0x72, 0x72, 0x72,
220 			  0x72, 0x72, 0x72, 0x72, 0x72, 0x72, 0x72, 0x72,
221 			},
222 	};
223 	struct some_bytes startat = {
224 		.data = { 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30,
225 			  0x79, 0x79, 0x79, 0x79, 0x79, 0x79, 0x79, 0x79,
226 			  0x79, 0x79, 0x79, 0x79, 0x79, 0x79, 0x79, 0x79,
227 			  0x79, 0x79, 0x79, 0x79, 0x79, 0x79, 0x79, 0x79,
228 			},
229 	};
230 	struct some_bytes dest = { };
231 	int count, value;
232 	u8 *ptr;
233 
234 	/* Verify static initializers. */
235 	check(control, 0x30);
236 	check(dest, 0);
237 
238 	/* Verify assignment. */
239 	dest = control;
240 	compare("direct assignment", dest, control);
241 
242 	/* Verify complete overwrite. */
243 	memset(dest.data, 0xff, sizeof(dest.data));
244 	compare("complete overwrite", dest, complete);
245 
246 	/* Verify middle overwrite. */
247 	dest = control;
248 	memset(dest.data + 4, 0x31, 16);
249 	compare("middle overwrite", dest, middle);
250 
251 	/* Verify argument side-effects aren't repeated. */
252 	dest = control;
253 	ptr = dest.data;
254 	value = 0x60;
255 	count = 1;
256 	memset(ptr++, value++, count++);
257 	ptr += 8;
258 	memset(ptr++, value++, count++);
259 	compare("argument side-effects", dest, three);
260 
261 	/* Verify memset_after() */
262 	dest = control;
263 	memset_after(&dest, 0x72, three);
264 	compare("memset_after()", dest, after);
265 
266 	/* Verify memset_startat() */
267 	dest = control;
268 	memset_startat(&dest, 0x79, four);
269 	compare("memset_startat()", dest, startat);
270 #undef TEST_OP
271 }
272 
273 static void strtomem_test(struct kunit *test)
274 {
275 	static const char input[sizeof(unsigned long)] = "hi";
276 	static const char truncate[] = "this is too long";
277 	struct {
278 		unsigned long canary1;
279 		unsigned char output[sizeof(unsigned long)] __nonstring;
280 		unsigned long canary2;
281 	} wrap;
282 
283 	memset(&wrap, 0xFF, sizeof(wrap));
284 	KUNIT_EXPECT_EQ_MSG(test, wrap.canary1, ULONG_MAX,
285 			    "bad initial canary value");
286 	KUNIT_EXPECT_EQ_MSG(test, wrap.canary2, ULONG_MAX,
287 			    "bad initial canary value");
288 
289 	/* Check unpadded copy leaves surroundings untouched. */
290 	strtomem(wrap.output, input);
291 	KUNIT_EXPECT_EQ(test, wrap.canary1, ULONG_MAX);
292 	KUNIT_EXPECT_EQ(test, wrap.output[0], input[0]);
293 	KUNIT_EXPECT_EQ(test, wrap.output[1], input[1]);
294 	for (size_t i = 2; i < sizeof(wrap.output); i++)
295 		KUNIT_EXPECT_EQ(test, wrap.output[i], 0xFF);
296 	KUNIT_EXPECT_EQ(test, wrap.canary2, ULONG_MAX);
297 
298 	/* Check truncated copy leaves surroundings untouched. */
299 	memset(&wrap, 0xFF, sizeof(wrap));
300 	strtomem(wrap.output, truncate);
301 	KUNIT_EXPECT_EQ(test, wrap.canary1, ULONG_MAX);
302 	for (size_t i = 0; i < sizeof(wrap.output); i++)
303 		KUNIT_EXPECT_EQ(test, wrap.output[i], truncate[i]);
304 	KUNIT_EXPECT_EQ(test, wrap.canary2, ULONG_MAX);
305 
306 	/* Check padded copy leaves only string padded. */
307 	memset(&wrap, 0xFF, sizeof(wrap));
308 	strtomem_pad(wrap.output, input, 0xAA);
309 	KUNIT_EXPECT_EQ(test, wrap.canary1, ULONG_MAX);
310 	KUNIT_EXPECT_EQ(test, wrap.output[0], input[0]);
311 	KUNIT_EXPECT_EQ(test, wrap.output[1], input[1]);
312 	for (size_t i = 2; i < sizeof(wrap.output); i++)
313 		KUNIT_EXPECT_EQ(test, wrap.output[i], 0xAA);
314 	KUNIT_EXPECT_EQ(test, wrap.canary2, ULONG_MAX);
315 
316 	/* Check truncated padded copy has no padding. */
317 	memset(&wrap, 0xFF, sizeof(wrap));
318 	strtomem(wrap.output, truncate);
319 	KUNIT_EXPECT_EQ(test, wrap.canary1, ULONG_MAX);
320 	for (size_t i = 0; i < sizeof(wrap.output); i++)
321 		KUNIT_EXPECT_EQ(test, wrap.output[i], truncate[i]);
322 	KUNIT_EXPECT_EQ(test, wrap.canary2, ULONG_MAX);
323 }
324 
325 static struct kunit_case memcpy_test_cases[] = {
326 	KUNIT_CASE(memset_test),
327 	KUNIT_CASE(memcpy_test),
328 	KUNIT_CASE(memmove_test),
329 	KUNIT_CASE(strtomem_test),
330 	{}
331 };
332 
333 static struct kunit_suite memcpy_test_suite = {
334 	.name = "memcpy",
335 	.test_cases = memcpy_test_cases,
336 };
337 
338 kunit_test_suite(memcpy_test_suite);
339 
340 MODULE_LICENSE("GPL");
341