xref: /openbmc/linux/lib/overflow_kunit.c (revision 82806c25)
1 // SPDX-License-Identifier: GPL-2.0 OR MIT
2 /*
3  * Test cases for arithmetic overflow checks. See:
4  * https://www.kernel.org/doc/html/latest/dev-tools/kunit/kunit-tool.html#configuring-building-and-running-tests
5  *	./tools/testing/kunit/kunit.py run overflow [--raw_output]
6  */
7 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
8 
9 #include <kunit/test.h>
10 #include <linux/device.h>
11 #include <linux/kernel.h>
12 #include <linux/mm.h>
13 #include <linux/module.h>
14 #include <linux/overflow.h>
15 #include <linux/slab.h>
16 #include <linux/types.h>
17 #include <linux/vmalloc.h>
18 
19 #define DEFINE_TEST_ARRAY(t)			\
20 	static const struct test_ ## t {	\
21 		t a, b;				\
22 		t sum, diff, prod;		\
23 		bool s_of, d_of, p_of;		\
24 	} t ## _tests[]
25 
26 DEFINE_TEST_ARRAY(u8) = {
27 	{0, 0, 0, 0, 0, false, false, false},
28 	{1, 1, 2, 0, 1, false, false, false},
29 	{0, 1, 1, U8_MAX, 0, false, true, false},
30 	{1, 0, 1, 1, 0, false, false, false},
31 	{0, U8_MAX, U8_MAX, 1, 0, false, true, false},
32 	{U8_MAX, 0, U8_MAX, U8_MAX, 0, false, false, false},
33 	{1, U8_MAX, 0, 2, U8_MAX, true, true, false},
34 	{U8_MAX, 1, 0, U8_MAX-1, U8_MAX, true, false, false},
35 	{U8_MAX, U8_MAX, U8_MAX-1, 0, 1, true, false, true},
36 
37 	{U8_MAX, U8_MAX-1, U8_MAX-2, 1, 2, true, false, true},
38 	{U8_MAX-1, U8_MAX, U8_MAX-2, U8_MAX, 2, true, true, true},
39 
40 	{1U << 3, 1U << 3, 1U << 4, 0, 1U << 6, false, false, false},
41 	{1U << 4, 1U << 4, 1U << 5, 0, 0, false, false, true},
42 	{1U << 4, 1U << 3, 3*(1U << 3), 1U << 3, 1U << 7, false, false, false},
43 	{1U << 7, 1U << 7, 0, 0, 0, true, false, true},
44 
45 	{48, 32, 80, 16, 0, false, false, true},
46 	{128, 128, 0, 0, 0, true, false, true},
47 	{123, 234, 101, 145, 110, true, true, true},
48 };
49 DEFINE_TEST_ARRAY(u16) = {
50 	{0, 0, 0, 0, 0, false, false, false},
51 	{1, 1, 2, 0, 1, false, false, false},
52 	{0, 1, 1, U16_MAX, 0, false, true, false},
53 	{1, 0, 1, 1, 0, false, false, false},
54 	{0, U16_MAX, U16_MAX, 1, 0, false, true, false},
55 	{U16_MAX, 0, U16_MAX, U16_MAX, 0, false, false, false},
56 	{1, U16_MAX, 0, 2, U16_MAX, true, true, false},
57 	{U16_MAX, 1, 0, U16_MAX-1, U16_MAX, true, false, false},
58 	{U16_MAX, U16_MAX, U16_MAX-1, 0, 1, true, false, true},
59 
60 	{U16_MAX, U16_MAX-1, U16_MAX-2, 1, 2, true, false, true},
61 	{U16_MAX-1, U16_MAX, U16_MAX-2, U16_MAX, 2, true, true, true},
62 
63 	{1U << 7, 1U << 7, 1U << 8, 0, 1U << 14, false, false, false},
64 	{1U << 8, 1U << 8, 1U << 9, 0, 0, false, false, true},
65 	{1U << 8, 1U << 7, 3*(1U << 7), 1U << 7, 1U << 15, false, false, false},
66 	{1U << 15, 1U << 15, 0, 0, 0, true, false, true},
67 
68 	{123, 234, 357, 65425, 28782, false, true, false},
69 	{1234, 2345, 3579, 64425, 10146, false, true, true},
70 };
71 DEFINE_TEST_ARRAY(u32) = {
72 	{0, 0, 0, 0, 0, false, false, false},
73 	{1, 1, 2, 0, 1, false, false, false},
74 	{0, 1, 1, U32_MAX, 0, false, true, false},
75 	{1, 0, 1, 1, 0, false, false, false},
76 	{0, U32_MAX, U32_MAX, 1, 0, false, true, false},
77 	{U32_MAX, 0, U32_MAX, U32_MAX, 0, false, false, false},
78 	{1, U32_MAX, 0, 2, U32_MAX, true, true, false},
79 	{U32_MAX, 1, 0, U32_MAX-1, U32_MAX, true, false, false},
80 	{U32_MAX, U32_MAX, U32_MAX-1, 0, 1, true, false, true},
81 
82 	{U32_MAX, U32_MAX-1, U32_MAX-2, 1, 2, true, false, true},
83 	{U32_MAX-1, U32_MAX, U32_MAX-2, U32_MAX, 2, true, true, true},
84 
85 	{1U << 15, 1U << 15, 1U << 16, 0, 1U << 30, false, false, false},
86 	{1U << 16, 1U << 16, 1U << 17, 0, 0, false, false, true},
87 	{1U << 16, 1U << 15, 3*(1U << 15), 1U << 15, 1U << 31, false, false, false},
88 	{1U << 31, 1U << 31, 0, 0, 0, true, false, true},
89 
90 	{-2U, 1U, -1U, -3U, -2U, false, false, false},
91 	{-4U, 5U, 1U, -9U, -20U, true, false, true},
92 };
93 
94 #if BITS_PER_LONG == 64
95 DEFINE_TEST_ARRAY(u64) = {
96 	{0, 0, 0, 0, 0, false, false, false},
97 	{1, 1, 2, 0, 1, false, false, false},
98 	{0, 1, 1, U64_MAX, 0, false, true, false},
99 	{1, 0, 1, 1, 0, false, false, false},
100 	{0, U64_MAX, U64_MAX, 1, 0, false, true, false},
101 	{U64_MAX, 0, U64_MAX, U64_MAX, 0, false, false, false},
102 	{1, U64_MAX, 0, 2, U64_MAX, true, true, false},
103 	{U64_MAX, 1, 0, U64_MAX-1, U64_MAX, true, false, false},
104 	{U64_MAX, U64_MAX, U64_MAX-1, 0, 1, true, false, true},
105 
106 	{U64_MAX, U64_MAX-1, U64_MAX-2, 1, 2, true, false, true},
107 	{U64_MAX-1, U64_MAX, U64_MAX-2, U64_MAX, 2, true, true, true},
108 
109 	{1ULL << 31, 1ULL << 31, 1ULL << 32, 0, 1ULL << 62, false, false, false},
110 	{1ULL << 32, 1ULL << 32, 1ULL << 33, 0, 0, false, false, true},
111 	{1ULL << 32, 1ULL << 31, 3*(1ULL << 31), 1ULL << 31, 1ULL << 63, false, false, false},
112 	{1ULL << 63, 1ULL << 63, 0, 0, 0, true, false, true},
113 	{1000000000ULL /* 10^9 */, 10000000000ULL /* 10^10 */,
114 	 11000000000ULL, 18446744064709551616ULL, 10000000000000000000ULL,
115 	 false, true, false},
116 	{-15ULL, 10ULL, -5ULL, -25ULL, -150ULL, false, false, true},
117 };
118 #endif
119 
120 DEFINE_TEST_ARRAY(s8) = {
121 	{0, 0, 0, 0, 0, false, false, false},
122 
123 	{0, S8_MAX, S8_MAX, -S8_MAX, 0, false, false, false},
124 	{S8_MAX, 0, S8_MAX, S8_MAX, 0, false, false, false},
125 	{0, S8_MIN, S8_MIN, S8_MIN, 0, false, true, false},
126 	{S8_MIN, 0, S8_MIN, S8_MIN, 0, false, false, false},
127 
128 	{-1, S8_MIN, S8_MAX, S8_MAX, S8_MIN, true, false, true},
129 	{S8_MIN, -1, S8_MAX, -S8_MAX, S8_MIN, true, false, true},
130 	{-1, S8_MAX, S8_MAX-1, S8_MIN, -S8_MAX, false, false, false},
131 	{S8_MAX, -1, S8_MAX-1, S8_MIN, -S8_MAX, false, true, false},
132 	{-1, -S8_MAX, S8_MIN, S8_MAX-1, S8_MAX, false, false, false},
133 	{-S8_MAX, -1, S8_MIN, S8_MIN+2, S8_MAX, false, false, false},
134 
135 	{1, S8_MIN, -S8_MAX, -S8_MAX, S8_MIN, false, true, false},
136 	{S8_MIN, 1, -S8_MAX, S8_MAX, S8_MIN, false, true, false},
137 	{1, S8_MAX, S8_MIN, S8_MIN+2, S8_MAX, true, false, false},
138 	{S8_MAX, 1, S8_MIN, S8_MAX-1, S8_MAX, true, false, false},
139 
140 	{S8_MIN, S8_MIN, 0, 0, 0, true, false, true},
141 	{S8_MAX, S8_MAX, -2, 0, 1, true, false, true},
142 
143 	{-4, -32, -36, 28, -128, false, false, true},
144 	{-4, 32, 28, -36, -128, false, false, false},
145 };
146 
147 DEFINE_TEST_ARRAY(s16) = {
148 	{0, 0, 0, 0, 0, false, false, false},
149 
150 	{0, S16_MAX, S16_MAX, -S16_MAX, 0, false, false, false},
151 	{S16_MAX, 0, S16_MAX, S16_MAX, 0, false, false, false},
152 	{0, S16_MIN, S16_MIN, S16_MIN, 0, false, true, false},
153 	{S16_MIN, 0, S16_MIN, S16_MIN, 0, false, false, false},
154 
155 	{-1, S16_MIN, S16_MAX, S16_MAX, S16_MIN, true, false, true},
156 	{S16_MIN, -1, S16_MAX, -S16_MAX, S16_MIN, true, false, true},
157 	{-1, S16_MAX, S16_MAX-1, S16_MIN, -S16_MAX, false, false, false},
158 	{S16_MAX, -1, S16_MAX-1, S16_MIN, -S16_MAX, false, true, false},
159 	{-1, -S16_MAX, S16_MIN, S16_MAX-1, S16_MAX, false, false, false},
160 	{-S16_MAX, -1, S16_MIN, S16_MIN+2, S16_MAX, false, false, false},
161 
162 	{1, S16_MIN, -S16_MAX, -S16_MAX, S16_MIN, false, true, false},
163 	{S16_MIN, 1, -S16_MAX, S16_MAX, S16_MIN, false, true, false},
164 	{1, S16_MAX, S16_MIN, S16_MIN+2, S16_MAX, true, false, false},
165 	{S16_MAX, 1, S16_MIN, S16_MAX-1, S16_MAX, true, false, false},
166 
167 	{S16_MIN, S16_MIN, 0, 0, 0, true, false, true},
168 	{S16_MAX, S16_MAX, -2, 0, 1, true, false, true},
169 };
170 DEFINE_TEST_ARRAY(s32) = {
171 	{0, 0, 0, 0, 0, false, false, false},
172 
173 	{0, S32_MAX, S32_MAX, -S32_MAX, 0, false, false, false},
174 	{S32_MAX, 0, S32_MAX, S32_MAX, 0, false, false, false},
175 	{0, S32_MIN, S32_MIN, S32_MIN, 0, false, true, false},
176 	{S32_MIN, 0, S32_MIN, S32_MIN, 0, false, false, false},
177 
178 	{-1, S32_MIN, S32_MAX, S32_MAX, S32_MIN, true, false, true},
179 	{S32_MIN, -1, S32_MAX, -S32_MAX, S32_MIN, true, false, true},
180 	{-1, S32_MAX, S32_MAX-1, S32_MIN, -S32_MAX, false, false, false},
181 	{S32_MAX, -1, S32_MAX-1, S32_MIN, -S32_MAX, false, true, false},
182 	{-1, -S32_MAX, S32_MIN, S32_MAX-1, S32_MAX, false, false, false},
183 	{-S32_MAX, -1, S32_MIN, S32_MIN+2, S32_MAX, false, false, false},
184 
185 	{1, S32_MIN, -S32_MAX, -S32_MAX, S32_MIN, false, true, false},
186 	{S32_MIN, 1, -S32_MAX, S32_MAX, S32_MIN, false, true, false},
187 	{1, S32_MAX, S32_MIN, S32_MIN+2, S32_MAX, true, false, false},
188 	{S32_MAX, 1, S32_MIN, S32_MAX-1, S32_MAX, true, false, false},
189 
190 	{S32_MIN, S32_MIN, 0, 0, 0, true, false, true},
191 	{S32_MAX, S32_MAX, -2, 0, 1, true, false, true},
192 };
193 
194 #if BITS_PER_LONG == 64
195 DEFINE_TEST_ARRAY(s64) = {
196 	{0, 0, 0, 0, 0, false, false, false},
197 
198 	{0, S64_MAX, S64_MAX, -S64_MAX, 0, false, false, false},
199 	{S64_MAX, 0, S64_MAX, S64_MAX, 0, false, false, false},
200 	{0, S64_MIN, S64_MIN, S64_MIN, 0, false, true, false},
201 	{S64_MIN, 0, S64_MIN, S64_MIN, 0, false, false, false},
202 
203 	{-1, S64_MIN, S64_MAX, S64_MAX, S64_MIN, true, false, true},
204 	{S64_MIN, -1, S64_MAX, -S64_MAX, S64_MIN, true, false, true},
205 	{-1, S64_MAX, S64_MAX-1, S64_MIN, -S64_MAX, false, false, false},
206 	{S64_MAX, -1, S64_MAX-1, S64_MIN, -S64_MAX, false, true, false},
207 	{-1, -S64_MAX, S64_MIN, S64_MAX-1, S64_MAX, false, false, false},
208 	{-S64_MAX, -1, S64_MIN, S64_MIN+2, S64_MAX, false, false, false},
209 
210 	{1, S64_MIN, -S64_MAX, -S64_MAX, S64_MIN, false, true, false},
211 	{S64_MIN, 1, -S64_MAX, S64_MAX, S64_MIN, false, true, false},
212 	{1, S64_MAX, S64_MIN, S64_MIN+2, S64_MAX, true, false, false},
213 	{S64_MAX, 1, S64_MIN, S64_MAX-1, S64_MAX, true, false, false},
214 
215 	{S64_MIN, S64_MIN, 0, 0, 0, true, false, true},
216 	{S64_MAX, S64_MAX, -2, 0, 1, true, false, true},
217 
218 	{-1, -1, -2, 0, 1, false, false, false},
219 	{-1, -128, -129, 127, 128, false, false, false},
220 	{-128, -1, -129, -127, 128, false, false, false},
221 	{0, -S64_MAX, -S64_MAX, S64_MAX, 0, false, false, false},
222 };
223 #endif
224 
225 #define check_one_op(t, fmt, op, sym, a, b, r, of) do {		\
226 	t _r;							\
227 	bool _of;						\
228 								\
229 	_of = check_ ## op ## _overflow(a, b, &_r);		\
230 	KUNIT_EXPECT_EQ_MSG(test, _of, of,			\
231 		"expected "fmt" "sym" "fmt" to%s overflow (type %s)\n",	\
232 		a, b, of ? "" : " not", #t);			\
233 	KUNIT_EXPECT_EQ_MSG(test, _r, r,			\
234 		"expected "fmt" "sym" "fmt" == "fmt", got "fmt" (type %s)\n", \
235 		a, b, r, _r, #t);				\
236 } while (0)
237 
238 #define DEFINE_TEST_FUNC(t, fmt)					\
239 static void do_test_ ## t(struct kunit *test, const struct test_ ## t *p) \
240 {							   		\
241 	check_one_op(t, fmt, add, "+", p->a, p->b, p->sum, p->s_of);	\
242 	check_one_op(t, fmt, add, "+", p->b, p->a, p->sum, p->s_of);	\
243 	check_one_op(t, fmt, sub, "-", p->a, p->b, p->diff, p->d_of);	\
244 	check_one_op(t, fmt, mul, "*", p->a, p->b, p->prod, p->p_of);	\
245 	check_one_op(t, fmt, mul, "*", p->b, p->a, p->prod, p->p_of);	\
246 }									\
247 									\
248 static void t ## _overflow_test(struct kunit *test) {			\
249 	unsigned i;							\
250 									\
251 	for (i = 0; i < ARRAY_SIZE(t ## _tests); ++i)			\
252 		do_test_ ## t(test, &t ## _tests[i]);			\
253 	kunit_info(test, "%zu %s arithmetic tests finished\n",		\
254 		ARRAY_SIZE(t ## _tests), #t);				\
255 }
256 
257 DEFINE_TEST_FUNC(u8, "%d");
258 DEFINE_TEST_FUNC(s8, "%d");
259 DEFINE_TEST_FUNC(u16, "%d");
260 DEFINE_TEST_FUNC(s16, "%d");
261 DEFINE_TEST_FUNC(u32, "%u");
262 DEFINE_TEST_FUNC(s32, "%d");
263 #if BITS_PER_LONG == 64
264 DEFINE_TEST_FUNC(u64, "%llu");
265 DEFINE_TEST_FUNC(s64, "%lld");
266 #endif
267 
268 static void overflow_shift_test(struct kunit *test)
269 {
270 	int count = 0;
271 
272 /* Args are: value, shift, type, expected result, overflow expected */
273 #define TEST_ONE_SHIFT(a, s, t, expect, of)	do {			\
274 	typeof(a) __a = (a);						\
275 	typeof(s) __s = (s);						\
276 	t __e = (expect);						\
277 	t __d;								\
278 	bool __of = check_shl_overflow(__a, __s, &__d);			\
279 	if (__of != of) {						\
280 		KUNIT_EXPECT_EQ_MSG(test, __of, of,			\
281 			"expected (%s)(%s << %s) to%s overflow\n",	\
282 			#t, #a, #s, of ? "" : " not");			\
283 	} else if (!__of && __d != __e) {				\
284 		KUNIT_EXPECT_EQ_MSG(test, __d, __e,			\
285 			"expected (%s)(%s << %s) == %s\n",		\
286 			#t, #a, #s, #expect);				\
287 		if ((t)-1 < 0)						\
288 			kunit_info(test, "got %lld\n", (s64)__d);	\
289 		else							\
290 			kunit_info(test, "got %llu\n", (u64)__d);	\
291 	}								\
292 	count++;							\
293 } while (0)
294 
295 	/* Sane shifts. */
296 	TEST_ONE_SHIFT(1, 0, u8, 1 << 0, false);
297 	TEST_ONE_SHIFT(1, 4, u8, 1 << 4, false);
298 	TEST_ONE_SHIFT(1, 7, u8, 1 << 7, false);
299 	TEST_ONE_SHIFT(0xF, 4, u8, 0xF << 4, false);
300 	TEST_ONE_SHIFT(1, 0, u16, 1 << 0, false);
301 	TEST_ONE_SHIFT(1, 10, u16, 1 << 10, false);
302 	TEST_ONE_SHIFT(1, 15, u16, 1 << 15, false);
303 	TEST_ONE_SHIFT(0xFF, 8, u16, 0xFF << 8, false);
304 	TEST_ONE_SHIFT(1, 0, int, 1 << 0, false);
305 	TEST_ONE_SHIFT(1, 16, int, 1 << 16, false);
306 	TEST_ONE_SHIFT(1, 30, int, 1 << 30, false);
307 	TEST_ONE_SHIFT(1, 0, s32, 1 << 0, false);
308 	TEST_ONE_SHIFT(1, 16, s32, 1 << 16, false);
309 	TEST_ONE_SHIFT(1, 30, s32, 1 << 30, false);
310 	TEST_ONE_SHIFT(1, 0, unsigned int, 1U << 0, false);
311 	TEST_ONE_SHIFT(1, 20, unsigned int, 1U << 20, false);
312 	TEST_ONE_SHIFT(1, 31, unsigned int, 1U << 31, false);
313 	TEST_ONE_SHIFT(0xFFFFU, 16, unsigned int, 0xFFFFU << 16, false);
314 	TEST_ONE_SHIFT(1, 0, u32, 1U << 0, false);
315 	TEST_ONE_SHIFT(1, 20, u32, 1U << 20, false);
316 	TEST_ONE_SHIFT(1, 31, u32, 1U << 31, false);
317 	TEST_ONE_SHIFT(0xFFFFU, 16, u32, 0xFFFFU << 16, false);
318 	TEST_ONE_SHIFT(1, 0, u64, 1ULL << 0, false);
319 	TEST_ONE_SHIFT(1, 40, u64, 1ULL << 40, false);
320 	TEST_ONE_SHIFT(1, 63, u64, 1ULL << 63, false);
321 	TEST_ONE_SHIFT(0xFFFFFFFFULL, 32, u64, 0xFFFFFFFFULL << 32, false);
322 
323 	/* Sane shift: start and end with 0, without a too-wide shift. */
324 	TEST_ONE_SHIFT(0, 7, u8, 0, false);
325 	TEST_ONE_SHIFT(0, 15, u16, 0, false);
326 	TEST_ONE_SHIFT(0, 31, unsigned int, 0, false);
327 	TEST_ONE_SHIFT(0, 31, u32, 0, false);
328 	TEST_ONE_SHIFT(0, 63, u64, 0, false);
329 
330 	/* Sane shift: start and end with 0, without reaching signed bit. */
331 	TEST_ONE_SHIFT(0, 6, s8, 0, false);
332 	TEST_ONE_SHIFT(0, 14, s16, 0, false);
333 	TEST_ONE_SHIFT(0, 30, int, 0, false);
334 	TEST_ONE_SHIFT(0, 30, s32, 0, false);
335 	TEST_ONE_SHIFT(0, 62, s64, 0, false);
336 
337 	/* Overflow: shifted the bit off the end. */
338 	TEST_ONE_SHIFT(1, 8, u8, 0, true);
339 	TEST_ONE_SHIFT(1, 16, u16, 0, true);
340 	TEST_ONE_SHIFT(1, 32, unsigned int, 0, true);
341 	TEST_ONE_SHIFT(1, 32, u32, 0, true);
342 	TEST_ONE_SHIFT(1, 64, u64, 0, true);
343 
344 	/* Overflow: shifted into the signed bit. */
345 	TEST_ONE_SHIFT(1, 7, s8, 0, true);
346 	TEST_ONE_SHIFT(1, 15, s16, 0, true);
347 	TEST_ONE_SHIFT(1, 31, int, 0, true);
348 	TEST_ONE_SHIFT(1, 31, s32, 0, true);
349 	TEST_ONE_SHIFT(1, 63, s64, 0, true);
350 
351 	/* Overflow: high bit falls off unsigned types. */
352 	/* 10010110 */
353 	TEST_ONE_SHIFT(150, 1, u8, 0, true);
354 	/* 1000100010010110 */
355 	TEST_ONE_SHIFT(34966, 1, u16, 0, true);
356 	/* 10000100000010001000100010010110 */
357 	TEST_ONE_SHIFT(2215151766U, 1, u32, 0, true);
358 	TEST_ONE_SHIFT(2215151766U, 1, unsigned int, 0, true);
359 	/* 1000001000010000010000000100000010000100000010001000100010010110 */
360 	TEST_ONE_SHIFT(9372061470395238550ULL, 1, u64, 0, true);
361 
362 	/* Overflow: bit shifted into signed bit on signed types. */
363 	/* 01001011 */
364 	TEST_ONE_SHIFT(75, 1, s8, 0, true);
365 	/* 0100010001001011 */
366 	TEST_ONE_SHIFT(17483, 1, s16, 0, true);
367 	/* 01000010000001000100010001001011 */
368 	TEST_ONE_SHIFT(1107575883, 1, s32, 0, true);
369 	TEST_ONE_SHIFT(1107575883, 1, int, 0, true);
370 	/* 0100000100001000001000000010000001000010000001000100010001001011 */
371 	TEST_ONE_SHIFT(4686030735197619275LL, 1, s64, 0, true);
372 
373 	/* Overflow: bit shifted past signed bit on signed types. */
374 	/* 01001011 */
375 	TEST_ONE_SHIFT(75, 2, s8, 0, true);
376 	/* 0100010001001011 */
377 	TEST_ONE_SHIFT(17483, 2, s16, 0, true);
378 	/* 01000010000001000100010001001011 */
379 	TEST_ONE_SHIFT(1107575883, 2, s32, 0, true);
380 	TEST_ONE_SHIFT(1107575883, 2, int, 0, true);
381 	/* 0100000100001000001000000010000001000010000001000100010001001011 */
382 	TEST_ONE_SHIFT(4686030735197619275LL, 2, s64, 0, true);
383 
384 	/* Overflow: values larger than destination type. */
385 	TEST_ONE_SHIFT(0x100, 0, u8, 0, true);
386 	TEST_ONE_SHIFT(0xFF, 0, s8, 0, true);
387 	TEST_ONE_SHIFT(0x10000U, 0, u16, 0, true);
388 	TEST_ONE_SHIFT(0xFFFFU, 0, s16, 0, true);
389 	TEST_ONE_SHIFT(0x100000000ULL, 0, u32, 0, true);
390 	TEST_ONE_SHIFT(0x100000000ULL, 0, unsigned int, 0, true);
391 	TEST_ONE_SHIFT(0xFFFFFFFFUL, 0, s32, 0, true);
392 	TEST_ONE_SHIFT(0xFFFFFFFFUL, 0, int, 0, true);
393 	TEST_ONE_SHIFT(0xFFFFFFFFFFFFFFFFULL, 0, s64, 0, true);
394 
395 	/* Nonsense: negative initial value. */
396 	TEST_ONE_SHIFT(-1, 0, s8, 0, true);
397 	TEST_ONE_SHIFT(-1, 0, u8, 0, true);
398 	TEST_ONE_SHIFT(-5, 0, s16, 0, true);
399 	TEST_ONE_SHIFT(-5, 0, u16, 0, true);
400 	TEST_ONE_SHIFT(-10, 0, int, 0, true);
401 	TEST_ONE_SHIFT(-10, 0, unsigned int, 0, true);
402 	TEST_ONE_SHIFT(-100, 0, s32, 0, true);
403 	TEST_ONE_SHIFT(-100, 0, u32, 0, true);
404 	TEST_ONE_SHIFT(-10000, 0, s64, 0, true);
405 	TEST_ONE_SHIFT(-10000, 0, u64, 0, true);
406 
407 	/* Nonsense: negative shift values. */
408 	TEST_ONE_SHIFT(0, -5, s8, 0, true);
409 	TEST_ONE_SHIFT(0, -5, u8, 0, true);
410 	TEST_ONE_SHIFT(0, -10, s16, 0, true);
411 	TEST_ONE_SHIFT(0, -10, u16, 0, true);
412 	TEST_ONE_SHIFT(0, -15, int, 0, true);
413 	TEST_ONE_SHIFT(0, -15, unsigned int, 0, true);
414 	TEST_ONE_SHIFT(0, -20, s32, 0, true);
415 	TEST_ONE_SHIFT(0, -20, u32, 0, true);
416 	TEST_ONE_SHIFT(0, -30, s64, 0, true);
417 	TEST_ONE_SHIFT(0, -30, u64, 0, true);
418 
419 	/* Overflow: shifted at or beyond entire type's bit width. */
420 	TEST_ONE_SHIFT(0, 8, u8, 0, true);
421 	TEST_ONE_SHIFT(0, 9, u8, 0, true);
422 	TEST_ONE_SHIFT(0, 8, s8, 0, true);
423 	TEST_ONE_SHIFT(0, 9, s8, 0, true);
424 	TEST_ONE_SHIFT(0, 16, u16, 0, true);
425 	TEST_ONE_SHIFT(0, 17, u16, 0, true);
426 	TEST_ONE_SHIFT(0, 16, s16, 0, true);
427 	TEST_ONE_SHIFT(0, 17, s16, 0, true);
428 	TEST_ONE_SHIFT(0, 32, u32, 0, true);
429 	TEST_ONE_SHIFT(0, 33, u32, 0, true);
430 	TEST_ONE_SHIFT(0, 32, int, 0, true);
431 	TEST_ONE_SHIFT(0, 33, int, 0, true);
432 	TEST_ONE_SHIFT(0, 32, s32, 0, true);
433 	TEST_ONE_SHIFT(0, 33, s32, 0, true);
434 	TEST_ONE_SHIFT(0, 64, u64, 0, true);
435 	TEST_ONE_SHIFT(0, 65, u64, 0, true);
436 	TEST_ONE_SHIFT(0, 64, s64, 0, true);
437 	TEST_ONE_SHIFT(0, 65, s64, 0, true);
438 
439 	/*
440 	 * Corner case: for unsigned types, we fail when we've shifted
441 	 * through the entire width of bits. For signed types, we might
442 	 * want to match this behavior, but that would mean noticing if
443 	 * we shift through all but the signed bit, and this is not
444 	 * currently detected (but we'll notice an overflow into the
445 	 * signed bit). So, for now, we will test this condition but
446 	 * mark it as not expected to overflow.
447 	 */
448 	TEST_ONE_SHIFT(0, 7, s8, 0, false);
449 	TEST_ONE_SHIFT(0, 15, s16, 0, false);
450 	TEST_ONE_SHIFT(0, 31, int, 0, false);
451 	TEST_ONE_SHIFT(0, 31, s32, 0, false);
452 	TEST_ONE_SHIFT(0, 63, s64, 0, false);
453 
454 	kunit_info(test, "%d shift tests finished\n", count);
455 #undef TEST_ONE_SHIFT
456 }
457 
458 /*
459  * Deal with the various forms of allocator arguments. See comments above
460  * the DEFINE_TEST_ALLOC() instances for mapping of the "bits".
461  */
462 #define alloc_GFP		 (GFP_KERNEL | __GFP_NOWARN)
463 #define alloc010(alloc, arg, sz) alloc(sz, alloc_GFP)
464 #define alloc011(alloc, arg, sz) alloc(sz, alloc_GFP, NUMA_NO_NODE)
465 #define alloc000(alloc, arg, sz) alloc(sz)
466 #define alloc001(alloc, arg, sz) alloc(sz, NUMA_NO_NODE)
467 #define alloc110(alloc, arg, sz) alloc(arg, sz, alloc_GFP)
468 #define free0(free, arg, ptr)	 free(ptr)
469 #define free1(free, arg, ptr)	 free(arg, ptr)
470 
471 /* Wrap around to 16K */
472 #define TEST_SIZE		(5 * 4096)
473 
474 #define DEFINE_TEST_ALLOC(func, free_func, want_arg, want_gfp, want_node)\
475 static void test_ ## func (struct kunit *test, void *arg)		\
476 {									\
477 	volatile size_t a = TEST_SIZE;					\
478 	volatile size_t b = (SIZE_MAX / TEST_SIZE) + 1;			\
479 	void *ptr;							\
480 									\
481 	/* Tiny allocation test. */					\
482 	ptr = alloc ## want_arg ## want_gfp ## want_node (func, arg, 1);\
483 	KUNIT_ASSERT_NOT_ERR_OR_NULL_MSG(test, ptr,			\
484 			    #func " failed regular allocation?!\n");	\
485 	free ## want_arg (free_func, arg, ptr);				\
486 									\
487 	/* Wrapped allocation test. */					\
488 	ptr = alloc ## want_arg ## want_gfp ## want_node (func, arg,	\
489 							  a * b);	\
490 	KUNIT_ASSERT_NOT_ERR_OR_NULL_MSG(test, ptr,			\
491 			    #func " unexpectedly failed bad wrapping?!\n"); \
492 	free ## want_arg (free_func, arg, ptr);				\
493 									\
494 	/* Saturated allocation test. */				\
495 	ptr = alloc ## want_arg ## want_gfp ## want_node (func, arg,	\
496 						   array_size(a, b));	\
497 	if (ptr) {							\
498 		KUNIT_FAIL(test, #func " missed saturation!\n");	\
499 		free ## want_arg (free_func, arg, ptr);			\
500 	}								\
501 }
502 
503 /*
504  * Allocator uses a trailing node argument --------+  (e.g. kmalloc_node())
505  * Allocator uses the gfp_t argument -----------+  |  (e.g. kmalloc())
506  * Allocator uses a special leading argument +  |  |  (e.g. devm_kmalloc())
507  *                                           |  |  |
508  */
509 DEFINE_TEST_ALLOC(kmalloc,	 kfree,	     0, 1, 0);
510 DEFINE_TEST_ALLOC(kmalloc_node,	 kfree,	     0, 1, 1);
511 DEFINE_TEST_ALLOC(kzalloc,	 kfree,	     0, 1, 0);
512 DEFINE_TEST_ALLOC(kzalloc_node,  kfree,	     0, 1, 1);
513 DEFINE_TEST_ALLOC(__vmalloc,	 vfree,	     0, 1, 0);
514 DEFINE_TEST_ALLOC(kvmalloc,	 kvfree,     0, 1, 0);
515 DEFINE_TEST_ALLOC(kvmalloc_node, kvfree,     0, 1, 1);
516 DEFINE_TEST_ALLOC(kvzalloc,	 kvfree,     0, 1, 0);
517 DEFINE_TEST_ALLOC(kvzalloc_node, kvfree,     0, 1, 1);
518 DEFINE_TEST_ALLOC(devm_kmalloc,  devm_kfree, 1, 1, 0);
519 DEFINE_TEST_ALLOC(devm_kzalloc,  devm_kfree, 1, 1, 0);
520 
521 static void overflow_allocation_test(struct kunit *test)
522 {
523 	const char device_name[] = "overflow-test";
524 	struct device *dev;
525 	int count = 0;
526 
527 #define check_allocation_overflow(alloc)	do {	\
528 	count++;					\
529 	test_ ## alloc(test, dev);			\
530 } while (0)
531 
532 	/* Create dummy device for devm_kmalloc()-family tests. */
533 	dev = root_device_register(device_name);
534 	KUNIT_ASSERT_FALSE_MSG(test, IS_ERR(dev),
535 			       "Cannot register test device\n");
536 
537 	check_allocation_overflow(kmalloc);
538 	check_allocation_overflow(kmalloc_node);
539 	check_allocation_overflow(kzalloc);
540 	check_allocation_overflow(kzalloc_node);
541 	check_allocation_overflow(__vmalloc);
542 	check_allocation_overflow(kvmalloc);
543 	check_allocation_overflow(kvmalloc_node);
544 	check_allocation_overflow(kvzalloc);
545 	check_allocation_overflow(kvzalloc_node);
546 	check_allocation_overflow(devm_kmalloc);
547 	check_allocation_overflow(devm_kzalloc);
548 
549 	device_unregister(dev);
550 
551 	kunit_info(test, "%d allocation overflow tests finished\n", count);
552 #undef check_allocation_overflow
553 }
554 
555 struct __test_flex_array {
556 	unsigned long flags;
557 	size_t count;
558 	unsigned long data[];
559 };
560 
561 static void overflow_size_helpers_test(struct kunit *test)
562 {
563 	/* Make sure struct_size() can be used in a constant expression. */
564 	u8 ce_array[struct_size((struct __test_flex_array *)0, data, 55)];
565 	struct __test_flex_array *obj;
566 	int count = 0;
567 	int var;
568 	volatile int unconst = 0;
569 
570 	/* Verify constant expression against runtime version. */
571 	var = 55;
572 	OPTIMIZER_HIDE_VAR(var);
573 	KUNIT_EXPECT_EQ(test, sizeof(ce_array), struct_size(obj, data, var));
574 
575 #define check_one_size_helper(expected, func, args...)	do {	\
576 	size_t _r = func(args);					\
577 	KUNIT_EXPECT_EQ_MSG(test, _r, expected,			\
578 		"expected " #func "(" #args ") to return %zu but got %zu instead\n", \
579 		(size_t)(expected), _r);			\
580 	count++;						\
581 } while (0)
582 
583 	var = 4;
584 	check_one_size_helper(20,	size_mul, var++, 5);
585 	check_one_size_helper(20,	size_mul, 4, var++);
586 	check_one_size_helper(0,	size_mul, 0, 3);
587 	check_one_size_helper(0,	size_mul, 3, 0);
588 	check_one_size_helper(6,	size_mul, 2, 3);
589 	check_one_size_helper(SIZE_MAX,	size_mul, SIZE_MAX,  1);
590 	check_one_size_helper(SIZE_MAX,	size_mul, SIZE_MAX,  3);
591 	check_one_size_helper(SIZE_MAX,	size_mul, SIZE_MAX, -3);
592 
593 	var = 4;
594 	check_one_size_helper(9,	size_add, var++, 5);
595 	check_one_size_helper(9,	size_add, 4, var++);
596 	check_one_size_helper(9,	size_add, 9, 0);
597 	check_one_size_helper(9,	size_add, 0, 9);
598 	check_one_size_helper(5,	size_add, 2, 3);
599 	check_one_size_helper(SIZE_MAX, size_add, SIZE_MAX,  1);
600 	check_one_size_helper(SIZE_MAX, size_add, SIZE_MAX,  3);
601 	check_one_size_helper(SIZE_MAX, size_add, SIZE_MAX, -3);
602 
603 	var = 4;
604 	check_one_size_helper(1,	size_sub, var--, 3);
605 	check_one_size_helper(1,	size_sub, 4, var--);
606 	check_one_size_helper(1,	size_sub, 3, 2);
607 	check_one_size_helper(9,	size_sub, 9, 0);
608 	check_one_size_helper(SIZE_MAX, size_sub, 9, -3);
609 	check_one_size_helper(SIZE_MAX, size_sub, 0, 9);
610 	check_one_size_helper(SIZE_MAX, size_sub, 2, 3);
611 	check_one_size_helper(SIZE_MAX, size_sub, SIZE_MAX,  0);
612 	check_one_size_helper(SIZE_MAX, size_sub, SIZE_MAX, 10);
613 	check_one_size_helper(SIZE_MAX, size_sub, 0,  SIZE_MAX);
614 	check_one_size_helper(SIZE_MAX, size_sub, 14, SIZE_MAX);
615 	check_one_size_helper(SIZE_MAX - 2, size_sub, SIZE_MAX - 1,  1);
616 	check_one_size_helper(SIZE_MAX - 4, size_sub, SIZE_MAX - 1,  3);
617 	check_one_size_helper(1,		size_sub, SIZE_MAX - 1, -3);
618 
619 	var = 4;
620 	check_one_size_helper(4 * sizeof(*obj->data),
621 			      flex_array_size, obj, data, var++);
622 	check_one_size_helper(5 * sizeof(*obj->data),
623 			      flex_array_size, obj, data, var++);
624 	check_one_size_helper(0, flex_array_size, obj, data, 0 + unconst);
625 	check_one_size_helper(sizeof(*obj->data),
626 			      flex_array_size, obj, data, 1 + unconst);
627 	check_one_size_helper(7 * sizeof(*obj->data),
628 			      flex_array_size, obj, data, 7 + unconst);
629 	check_one_size_helper(SIZE_MAX,
630 			      flex_array_size, obj, data, -1 + unconst);
631 	check_one_size_helper(SIZE_MAX,
632 			      flex_array_size, obj, data, SIZE_MAX - 4 + unconst);
633 
634 	var = 4;
635 	check_one_size_helper(sizeof(*obj) + (4 * sizeof(*obj->data)),
636 			      struct_size, obj, data, var++);
637 	check_one_size_helper(sizeof(*obj) + (5 * sizeof(*obj->data)),
638 			      struct_size, obj, data, var++);
639 	check_one_size_helper(sizeof(*obj), struct_size, obj, data, 0 + unconst);
640 	check_one_size_helper(sizeof(*obj) + sizeof(*obj->data),
641 			      struct_size, obj, data, 1 + unconst);
642 	check_one_size_helper(SIZE_MAX,
643 			      struct_size, obj, data, -3 + unconst);
644 	check_one_size_helper(SIZE_MAX,
645 			      struct_size, obj, data, SIZE_MAX - 3 + unconst);
646 
647 	kunit_info(test, "%d overflow size helper tests finished\n", count);
648 #undef check_one_size_helper
649 }
650 
651 static struct kunit_case overflow_test_cases[] = {
652 	KUNIT_CASE(u8_overflow_test),
653 	KUNIT_CASE(s8_overflow_test),
654 	KUNIT_CASE(u16_overflow_test),
655 	KUNIT_CASE(s16_overflow_test),
656 	KUNIT_CASE(u32_overflow_test),
657 	KUNIT_CASE(s32_overflow_test),
658 /* Clang 13 and earlier generate unwanted libcalls on 32-bit. */
659 #if BITS_PER_LONG == 64
660 	KUNIT_CASE(u64_overflow_test),
661 	KUNIT_CASE(s64_overflow_test),
662 #endif
663 	KUNIT_CASE(overflow_shift_test),
664 	KUNIT_CASE(overflow_allocation_test),
665 	KUNIT_CASE(overflow_size_helpers_test),
666 	{}
667 };
668 
669 static struct kunit_suite overflow_test_suite = {
670 	.name = "overflow",
671 	.test_cases = overflow_test_cases,
672 };
673 
674 kunit_test_suite(overflow_test_suite);
675 
676 MODULE_LICENSE("Dual MIT/GPL");
677