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  1// SPDX-License-Identifier: GPL-2.0 OR MIT
  2/*
  3 * Test cases for arithmetic overflow checks.
  4 */
  5#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  6
  7#include <linux/device.h>
  8#include <linux/init.h>
  9#include <linux/kernel.h>
 10#include <linux/mm.h>
 11#include <linux/module.h>
 12#include <linux/overflow.h>
 13#include <linux/slab.h>
 14#include <linux/types.h>
 15#include <linux/vmalloc.h>
 16
 17#define DEFINE_TEST_ARRAY(t)			\
 18	static const struct test_ ## t {	\
 19		t a, b;				\
 20		t sum, diff, prod;		\
 21		bool s_of, d_of, p_of;		\
 22	} t ## _tests[] __initconst
 23
 24DEFINE_TEST_ARRAY(u8) = {
 25	{0, 0, 0, 0, 0, false, false, false},
 26	{1, 1, 2, 0, 1, false, false, false},
 27	{0, 1, 1, U8_MAX, 0, false, true, false},
 28	{1, 0, 1, 1, 0, false, false, false},
 29	{0, U8_MAX, U8_MAX, 1, 0, false, true, false},
 30	{U8_MAX, 0, U8_MAX, U8_MAX, 0, false, false, false},
 31	{1, U8_MAX, 0, 2, U8_MAX, true, true, false},
 32	{U8_MAX, 1, 0, U8_MAX-1, U8_MAX, true, false, false},
 33	{U8_MAX, U8_MAX, U8_MAX-1, 0, 1, true, false, true},
 34
 35	{U8_MAX, U8_MAX-1, U8_MAX-2, 1, 2, true, false, true},
 36	{U8_MAX-1, U8_MAX, U8_MAX-2, U8_MAX, 2, true, true, true},
 37
 38	{1U << 3, 1U << 3, 1U << 4, 0, 1U << 6, false, false, false},
 39	{1U << 4, 1U << 4, 1U << 5, 0, 0, false, false, true},
 40	{1U << 4, 1U << 3, 3*(1U << 3), 1U << 3, 1U << 7, false, false, false},
 41	{1U << 7, 1U << 7, 0, 0, 0, true, false, true},
 42
 43	{48, 32, 80, 16, 0, false, false, true},
 44	{128, 128, 0, 0, 0, true, false, true},
 45	{123, 234, 101, 145, 110, true, true, true},
 46};
 47DEFINE_TEST_ARRAY(u16) = {
 48	{0, 0, 0, 0, 0, false, false, false},
 49	{1, 1, 2, 0, 1, false, false, false},
 50	{0, 1, 1, U16_MAX, 0, false, true, false},
 51	{1, 0, 1, 1, 0, false, false, false},
 52	{0, U16_MAX, U16_MAX, 1, 0, false, true, false},
 53	{U16_MAX, 0, U16_MAX, U16_MAX, 0, false, false, false},
 54	{1, U16_MAX, 0, 2, U16_MAX, true, true, false},
 55	{U16_MAX, 1, 0, U16_MAX-1, U16_MAX, true, false, false},
 56	{U16_MAX, U16_MAX, U16_MAX-1, 0, 1, true, false, true},
 57
 58	{U16_MAX, U16_MAX-1, U16_MAX-2, 1, 2, true, false, true},
 59	{U16_MAX-1, U16_MAX, U16_MAX-2, U16_MAX, 2, true, true, true},
 60
 61	{1U << 7, 1U << 7, 1U << 8, 0, 1U << 14, false, false, false},
 62	{1U << 8, 1U << 8, 1U << 9, 0, 0, false, false, true},
 63	{1U << 8, 1U << 7, 3*(1U << 7), 1U << 7, 1U << 15, false, false, false},
 64	{1U << 15, 1U << 15, 0, 0, 0, true, false, true},
 65
 66	{123, 234, 357, 65425, 28782, false, true, false},
 67	{1234, 2345, 3579, 64425, 10146, false, true, true},
 68};
 69DEFINE_TEST_ARRAY(u32) = {
 70	{0, 0, 0, 0, 0, false, false, false},
 71	{1, 1, 2, 0, 1, false, false, false},
 72	{0, 1, 1, U32_MAX, 0, false, true, false},
 73	{1, 0, 1, 1, 0, false, false, false},
 74	{0, U32_MAX, U32_MAX, 1, 0, false, true, false},
 75	{U32_MAX, 0, U32_MAX, U32_MAX, 0, false, false, false},
 76	{1, U32_MAX, 0, 2, U32_MAX, true, true, false},
 77	{U32_MAX, 1, 0, U32_MAX-1, U32_MAX, true, false, false},
 78	{U32_MAX, U32_MAX, U32_MAX-1, 0, 1, true, false, true},
 79
 80	{U32_MAX, U32_MAX-1, U32_MAX-2, 1, 2, true, false, true},
 81	{U32_MAX-1, U32_MAX, U32_MAX-2, U32_MAX, 2, true, true, true},
 82
 83	{1U << 15, 1U << 15, 1U << 16, 0, 1U << 30, false, false, false},
 84	{1U << 16, 1U << 16, 1U << 17, 0, 0, false, false, true},
 85	{1U << 16, 1U << 15, 3*(1U << 15), 1U << 15, 1U << 31, false, false, false},
 86	{1U << 31, 1U << 31, 0, 0, 0, true, false, true},
 87
 88	{-2U, 1U, -1U, -3U, -2U, false, false, false},
 89	{-4U, 5U, 1U, -9U, -20U, true, false, true},
 90};
 91
 92DEFINE_TEST_ARRAY(u64) = {
 93	{0, 0, 0, 0, 0, false, false, false},
 94	{1, 1, 2, 0, 1, false, false, false},
 95	{0, 1, 1, U64_MAX, 0, false, true, false},
 96	{1, 0, 1, 1, 0, false, false, false},
 97	{0, U64_MAX, U64_MAX, 1, 0, false, true, false},
 98	{U64_MAX, 0, U64_MAX, U64_MAX, 0, false, false, false},
 99	{1, U64_MAX, 0, 2, U64_MAX, true, true, false},
100	{U64_MAX, 1, 0, U64_MAX-1, U64_MAX, true, false, false},
101	{U64_MAX, U64_MAX, U64_MAX-1, 0, 1, true, false, true},
102
103	{U64_MAX, U64_MAX-1, U64_MAX-2, 1, 2, true, false, true},
104	{U64_MAX-1, U64_MAX, U64_MAX-2, U64_MAX, 2, true, true, true},
105
106	{1ULL << 31, 1ULL << 31, 1ULL << 32, 0, 1ULL << 62, false, false, false},
107	{1ULL << 32, 1ULL << 32, 1ULL << 33, 0, 0, false, false, true},
108	{1ULL << 32, 1ULL << 31, 3*(1ULL << 31), 1ULL << 31, 1ULL << 63, false, false, false},
109	{1ULL << 63, 1ULL << 63, 0, 0, 0, true, false, true},
110	{1000000000ULL /* 10^9 */, 10000000000ULL /* 10^10 */,
111	 11000000000ULL, 18446744064709551616ULL, 10000000000000000000ULL,
112	 false, true, false},
113	{-15ULL, 10ULL, -5ULL, -25ULL, -150ULL, false, false, true},
114};
115
116DEFINE_TEST_ARRAY(s8) = {
117	{0, 0, 0, 0, 0, false, false, false},
118
119	{0, S8_MAX, S8_MAX, -S8_MAX, 0, false, false, false},
120	{S8_MAX, 0, S8_MAX, S8_MAX, 0, false, false, false},
121	{0, S8_MIN, S8_MIN, S8_MIN, 0, false, true, false},
122	{S8_MIN, 0, S8_MIN, S8_MIN, 0, false, false, false},
123
124	{-1, S8_MIN, S8_MAX, S8_MAX, S8_MIN, true, false, true},
125	{S8_MIN, -1, S8_MAX, -S8_MAX, S8_MIN, true, false, true},
126	{-1, S8_MAX, S8_MAX-1, S8_MIN, -S8_MAX, false, false, false},
127	{S8_MAX, -1, S8_MAX-1, S8_MIN, -S8_MAX, false, true, false},
128	{-1, -S8_MAX, S8_MIN, S8_MAX-1, S8_MAX, false, false, false},
129	{-S8_MAX, -1, S8_MIN, S8_MIN+2, S8_MAX, false, false, false},
130
131	{1, S8_MIN, -S8_MAX, -S8_MAX, S8_MIN, false, true, false},
132	{S8_MIN, 1, -S8_MAX, S8_MAX, S8_MIN, false, true, false},
133	{1, S8_MAX, S8_MIN, S8_MIN+2, S8_MAX, true, false, false},
134	{S8_MAX, 1, S8_MIN, S8_MAX-1, S8_MAX, true, false, false},
135
136	{S8_MIN, S8_MIN, 0, 0, 0, true, false, true},
137	{S8_MAX, S8_MAX, -2, 0, 1, true, false, true},
138
139	{-4, -32, -36, 28, -128, false, false, true},
140	{-4, 32, 28, -36, -128, false, false, false},
141};
142
143DEFINE_TEST_ARRAY(s16) = {
144	{0, 0, 0, 0, 0, false, false, false},
145
146	{0, S16_MAX, S16_MAX, -S16_MAX, 0, false, false, false},
147	{S16_MAX, 0, S16_MAX, S16_MAX, 0, false, false, false},
148	{0, S16_MIN, S16_MIN, S16_MIN, 0, false, true, false},
149	{S16_MIN, 0, S16_MIN, S16_MIN, 0, false, false, false},
150
151	{-1, S16_MIN, S16_MAX, S16_MAX, S16_MIN, true, false, true},
152	{S16_MIN, -1, S16_MAX, -S16_MAX, S16_MIN, true, false, true},
153	{-1, S16_MAX, S16_MAX-1, S16_MIN, -S16_MAX, false, false, false},
154	{S16_MAX, -1, S16_MAX-1, S16_MIN, -S16_MAX, false, true, false},
155	{-1, -S16_MAX, S16_MIN, S16_MAX-1, S16_MAX, false, false, false},
156	{-S16_MAX, -1, S16_MIN, S16_MIN+2, S16_MAX, false, false, false},
157
158	{1, S16_MIN, -S16_MAX, -S16_MAX, S16_MIN, false, true, false},
159	{S16_MIN, 1, -S16_MAX, S16_MAX, S16_MIN, false, true, false},
160	{1, S16_MAX, S16_MIN, S16_MIN+2, S16_MAX, true, false, false},
161	{S16_MAX, 1, S16_MIN, S16_MAX-1, S16_MAX, true, false, false},
162
163	{S16_MIN, S16_MIN, 0, 0, 0, true, false, true},
164	{S16_MAX, S16_MAX, -2, 0, 1, true, false, true},
165};
166DEFINE_TEST_ARRAY(s32) = {
167	{0, 0, 0, 0, 0, false, false, false},
168
169	{0, S32_MAX, S32_MAX, -S32_MAX, 0, false, false, false},
170	{S32_MAX, 0, S32_MAX, S32_MAX, 0, false, false, false},
171	{0, S32_MIN, S32_MIN, S32_MIN, 0, false, true, false},
172	{S32_MIN, 0, S32_MIN, S32_MIN, 0, false, false, false},
173
174	{-1, S32_MIN, S32_MAX, S32_MAX, S32_MIN, true, false, true},
175	{S32_MIN, -1, S32_MAX, -S32_MAX, S32_MIN, true, false, true},
176	{-1, S32_MAX, S32_MAX-1, S32_MIN, -S32_MAX, false, false, false},
177	{S32_MAX, -1, S32_MAX-1, S32_MIN, -S32_MAX, false, true, false},
178	{-1, -S32_MAX, S32_MIN, S32_MAX-1, S32_MAX, false, false, false},
179	{-S32_MAX, -1, S32_MIN, S32_MIN+2, S32_MAX, false, false, false},
180
181	{1, S32_MIN, -S32_MAX, -S32_MAX, S32_MIN, false, true, false},
182	{S32_MIN, 1, -S32_MAX, S32_MAX, S32_MIN, false, true, false},
183	{1, S32_MAX, S32_MIN, S32_MIN+2, S32_MAX, true, false, false},
184	{S32_MAX, 1, S32_MIN, S32_MAX-1, S32_MAX, true, false, false},
185
186	{S32_MIN, S32_MIN, 0, 0, 0, true, false, true},
187	{S32_MAX, S32_MAX, -2, 0, 1, true, false, true},
188};
189DEFINE_TEST_ARRAY(s64) = {
190	{0, 0, 0, 0, 0, false, false, false},
191
192	{0, S64_MAX, S64_MAX, -S64_MAX, 0, false, false, false},
193	{S64_MAX, 0, S64_MAX, S64_MAX, 0, false, false, false},
194	{0, S64_MIN, S64_MIN, S64_MIN, 0, false, true, false},
195	{S64_MIN, 0, S64_MIN, S64_MIN, 0, false, false, false},
196
197	{-1, S64_MIN, S64_MAX, S64_MAX, S64_MIN, true, false, true},
198	{S64_MIN, -1, S64_MAX, -S64_MAX, S64_MIN, true, false, true},
199	{-1, S64_MAX, S64_MAX-1, S64_MIN, -S64_MAX, false, false, false},
200	{S64_MAX, -1, S64_MAX-1, S64_MIN, -S64_MAX, false, true, false},
201	{-1, -S64_MAX, S64_MIN, S64_MAX-1, S64_MAX, false, false, false},
202	{-S64_MAX, -1, S64_MIN, S64_MIN+2, S64_MAX, false, false, false},
203
204	{1, S64_MIN, -S64_MAX, -S64_MAX, S64_MIN, false, true, false},
205	{S64_MIN, 1, -S64_MAX, S64_MAX, S64_MIN, false, true, false},
206	{1, S64_MAX, S64_MIN, S64_MIN+2, S64_MAX, true, false, false},
207	{S64_MAX, 1, S64_MIN, S64_MAX-1, S64_MAX, true, false, false},
208
209	{S64_MIN, S64_MIN, 0, 0, 0, true, false, true},
210	{S64_MAX, S64_MAX, -2, 0, 1, true, false, true},
211
212	{-1, -1, -2, 0, 1, false, false, false},
213	{-1, -128, -129, 127, 128, false, false, false},
214	{-128, -1, -129, -127, 128, false, false, false},
215	{0, -S64_MAX, -S64_MAX, S64_MAX, 0, false, false, false},
216};
217
218#define check_one_op(t, fmt, op, sym, a, b, r, of) do {		\
219	t _r;							\
220	bool _of;						\
221								\
222	_of = check_ ## op ## _overflow(a, b, &_r);		\
223	if (_of != of) {					\
224		pr_warn("expected "fmt" "sym" "fmt		\
225			" to%s overflow (type %s)\n",		\
226			a, b, of ? "" : " not", #t);		\
227		err = 1;					\
228	}							\
229	if (_r != r) {						\
230		pr_warn("expected "fmt" "sym" "fmt" == "	\
231			fmt", got "fmt" (type %s)\n",		\
232			a, b, r, _r, #t);			\
233		err = 1;					\
234	}							\
235} while (0)
236
237#define DEFINE_TEST_FUNC(t, fmt)					\
238static int __init do_test_ ## t(const struct test_ ## t *p)		\
239{							   		\
240	int err = 0;							\
241									\
242	check_one_op(t, fmt, add, "+", p->a, p->b, p->sum, p->s_of);	\
243	check_one_op(t, fmt, add, "+", p->b, p->a, p->sum, p->s_of);	\
244	check_one_op(t, fmt, sub, "-", p->a, p->b, p->diff, p->d_of);	\
245	check_one_op(t, fmt, mul, "*", p->a, p->b, p->prod, p->p_of);	\
246	check_one_op(t, fmt, mul, "*", p->b, p->a, p->prod, p->p_of);	\
247									\
248	return err;							\
249}									\
250									\
251static int __init test_ ## t ## _overflow(void) {			\
252	int err = 0;							\
253	unsigned i;							\
254									\
255	pr_info("%-3s: %zu arithmetic tests\n", #t,			\
256		ARRAY_SIZE(t ## _tests));				\
257	for (i = 0; i < ARRAY_SIZE(t ## _tests); ++i)			\
258		err |= do_test_ ## t(&t ## _tests[i]);			\
259	return err;							\
260}
261
262DEFINE_TEST_FUNC(u8, "%d");
263DEFINE_TEST_FUNC(s8, "%d");
264DEFINE_TEST_FUNC(u16, "%d");
265DEFINE_TEST_FUNC(s16, "%d");
266DEFINE_TEST_FUNC(u32, "%u");
267DEFINE_TEST_FUNC(s32, "%d");
268#if BITS_PER_LONG == 64
269DEFINE_TEST_FUNC(u64, "%llu");
270DEFINE_TEST_FUNC(s64, "%lld");
271#endif
272
273static int __init test_overflow_calculation(void)
274{
275	int err = 0;
276
277	err |= test_u8_overflow();
278	err |= test_s8_overflow();
279	err |= test_u16_overflow();
280	err |= test_s16_overflow();
281	err |= test_u32_overflow();
282	err |= test_s32_overflow();
283#if BITS_PER_LONG == 64
284	err |= test_u64_overflow();
285	err |= test_s64_overflow();
286#endif
287
288	return err;
289}
290
291static int __init test_overflow_shift(void)
292{
293	int err = 0;
294
295/* Args are: value, shift, type, expected result, overflow expected */
296#define TEST_ONE_SHIFT(a, s, t, expect, of) ({				\
297	int __failed = 0;						\
298	typeof(a) __a = (a);						\
299	typeof(s) __s = (s);						\
300	t __e = (expect);						\
301	t __d;								\
302	bool __of = check_shl_overflow(__a, __s, &__d);			\
303	if (__of != of) {						\
304		pr_warn("expected (%s)(%s << %s) to%s overflow\n",	\
305			#t, #a, #s, of ? "" : " not");			\
306		__failed = 1;						\
307	} else if (!__of && __d != __e) {				\
308		pr_warn("expected (%s)(%s << %s) == %s\n",		\
309			#t, #a, #s, #expect);				\
310		if ((t)-1 < 0)						\
311			pr_warn("got %lld\n", (s64)__d);		\
312		else							\
313			pr_warn("got %llu\n", (u64)__d);		\
314		__failed = 1;						\
315	}								\
316	if (!__failed)							\
317		pr_info("ok: (%s)(%s << %s) == %s\n", #t, #a, #s,	\
318			of ? "overflow" : #expect);			\
319	__failed;							\
320})
321
322	/* Sane shifts. */
323	err |= TEST_ONE_SHIFT(1, 0, u8, 1 << 0, false);
324	err |= TEST_ONE_SHIFT(1, 4, u8, 1 << 4, false);
325	err |= TEST_ONE_SHIFT(1, 7, u8, 1 << 7, false);
326	err |= TEST_ONE_SHIFT(0xF, 4, u8, 0xF << 4, false);
327	err |= TEST_ONE_SHIFT(1, 0, u16, 1 << 0, false);
328	err |= TEST_ONE_SHIFT(1, 10, u16, 1 << 10, false);
329	err |= TEST_ONE_SHIFT(1, 15, u16, 1 << 15, false);
330	err |= TEST_ONE_SHIFT(0xFF, 8, u16, 0xFF << 8, false);
331	err |= TEST_ONE_SHIFT(1, 0, int, 1 << 0, false);
332	err |= TEST_ONE_SHIFT(1, 16, int, 1 << 16, false);
333	err |= TEST_ONE_SHIFT(1, 30, int, 1 << 30, false);
334	err |= TEST_ONE_SHIFT(1, 0, s32, 1 << 0, false);
335	err |= TEST_ONE_SHIFT(1, 16, s32, 1 << 16, false);
336	err |= TEST_ONE_SHIFT(1, 30, s32, 1 << 30, false);
337	err |= TEST_ONE_SHIFT(1, 0, unsigned int, 1U << 0, false);
338	err |= TEST_ONE_SHIFT(1, 20, unsigned int, 1U << 20, false);
339	err |= TEST_ONE_SHIFT(1, 31, unsigned int, 1U << 31, false);
340	err |= TEST_ONE_SHIFT(0xFFFFU, 16, unsigned int, 0xFFFFU << 16, false);
341	err |= TEST_ONE_SHIFT(1, 0, u32, 1U << 0, false);
342	err |= TEST_ONE_SHIFT(1, 20, u32, 1U << 20, false);
343	err |= TEST_ONE_SHIFT(1, 31, u32, 1U << 31, false);
344	err |= TEST_ONE_SHIFT(0xFFFFU, 16, u32, 0xFFFFU << 16, false);
345	err |= TEST_ONE_SHIFT(1, 0, u64, 1ULL << 0, false);
346	err |= TEST_ONE_SHIFT(1, 40, u64, 1ULL << 40, false);
347	err |= TEST_ONE_SHIFT(1, 63, u64, 1ULL << 63, false);
348	err |= TEST_ONE_SHIFT(0xFFFFFFFFULL, 32, u64,
349			      0xFFFFFFFFULL << 32, false);
350
351	/* Sane shift: start and end with 0, without a too-wide shift. */
352	err |= TEST_ONE_SHIFT(0, 7, u8, 0, false);
353	err |= TEST_ONE_SHIFT(0, 15, u16, 0, false);
354	err |= TEST_ONE_SHIFT(0, 31, unsigned int, 0, false);
355	err |= TEST_ONE_SHIFT(0, 31, u32, 0, false);
356	err |= TEST_ONE_SHIFT(0, 63, u64, 0, false);
357
358	/* Sane shift: start and end with 0, without reaching signed bit. */
359	err |= TEST_ONE_SHIFT(0, 6, s8, 0, false);
360	err |= TEST_ONE_SHIFT(0, 14, s16, 0, false);
361	err |= TEST_ONE_SHIFT(0, 30, int, 0, false);
362	err |= TEST_ONE_SHIFT(0, 30, s32, 0, false);
363	err |= TEST_ONE_SHIFT(0, 62, s64, 0, false);
364
365	/* Overflow: shifted the bit off the end. */
366	err |= TEST_ONE_SHIFT(1, 8, u8, 0, true);
367	err |= TEST_ONE_SHIFT(1, 16, u16, 0, true);
368	err |= TEST_ONE_SHIFT(1, 32, unsigned int, 0, true);
369	err |= TEST_ONE_SHIFT(1, 32, u32, 0, true);
370	err |= TEST_ONE_SHIFT(1, 64, u64, 0, true);
371
372	/* Overflow: shifted into the signed bit. */
373	err |= TEST_ONE_SHIFT(1, 7, s8, 0, true);
374	err |= TEST_ONE_SHIFT(1, 15, s16, 0, true);
375	err |= TEST_ONE_SHIFT(1, 31, int, 0, true);
376	err |= TEST_ONE_SHIFT(1, 31, s32, 0, true);
377	err |= TEST_ONE_SHIFT(1, 63, s64, 0, true);
378
379	/* Overflow: high bit falls off unsigned types. */
380	/* 10010110 */
381	err |= TEST_ONE_SHIFT(150, 1, u8, 0, true);
382	/* 1000100010010110 */
383	err |= TEST_ONE_SHIFT(34966, 1, u16, 0, true);
384	/* 10000100000010001000100010010110 */
385	err |= TEST_ONE_SHIFT(2215151766U, 1, u32, 0, true);
386	err |= TEST_ONE_SHIFT(2215151766U, 1, unsigned int, 0, true);
387	/* 1000001000010000010000000100000010000100000010001000100010010110 */
388	err |= TEST_ONE_SHIFT(9372061470395238550ULL, 1, u64, 0, true);
389
390	/* Overflow: bit shifted into signed bit on signed types. */
391	/* 01001011 */
392	err |= TEST_ONE_SHIFT(75, 1, s8, 0, true);
393	/* 0100010001001011 */
394	err |= TEST_ONE_SHIFT(17483, 1, s16, 0, true);
395	/* 01000010000001000100010001001011 */
396	err |= TEST_ONE_SHIFT(1107575883, 1, s32, 0, true);
397	err |= TEST_ONE_SHIFT(1107575883, 1, int, 0, true);
398	/* 0100000100001000001000000010000001000010000001000100010001001011 */
399	err |= TEST_ONE_SHIFT(4686030735197619275LL, 1, s64, 0, true);
400
401	/* Overflow: bit shifted past signed bit on signed types. */
402	/* 01001011 */
403	err |= TEST_ONE_SHIFT(75, 2, s8, 0, true);
404	/* 0100010001001011 */
405	err |= TEST_ONE_SHIFT(17483, 2, s16, 0, true);
406	/* 01000010000001000100010001001011 */
407	err |= TEST_ONE_SHIFT(1107575883, 2, s32, 0, true);
408	err |= TEST_ONE_SHIFT(1107575883, 2, int, 0, true);
409	/* 0100000100001000001000000010000001000010000001000100010001001011 */
410	err |= TEST_ONE_SHIFT(4686030735197619275LL, 2, s64, 0, true);
411
412	/* Overflow: values larger than destination type. */
413	err |= TEST_ONE_SHIFT(0x100, 0, u8, 0, true);
414	err |= TEST_ONE_SHIFT(0xFF, 0, s8, 0, true);
415	err |= TEST_ONE_SHIFT(0x10000U, 0, u16, 0, true);
416	err |= TEST_ONE_SHIFT(0xFFFFU, 0, s16, 0, true);
417	err |= TEST_ONE_SHIFT(0x100000000ULL, 0, u32, 0, true);
418	err |= TEST_ONE_SHIFT(0x100000000ULL, 0, unsigned int, 0, true);
419	err |= TEST_ONE_SHIFT(0xFFFFFFFFUL, 0, s32, 0, true);
420	err |= TEST_ONE_SHIFT(0xFFFFFFFFUL, 0, int, 0, true);
421	err |= TEST_ONE_SHIFT(0xFFFFFFFFFFFFFFFFULL, 0, s64, 0, true);
422
423	/* Nonsense: negative initial value. */
424	err |= TEST_ONE_SHIFT(-1, 0, s8, 0, true);
425	err |= TEST_ONE_SHIFT(-1, 0, u8, 0, true);
426	err |= TEST_ONE_SHIFT(-5, 0, s16, 0, true);
427	err |= TEST_ONE_SHIFT(-5, 0, u16, 0, true);
428	err |= TEST_ONE_SHIFT(-10, 0, int, 0, true);
429	err |= TEST_ONE_SHIFT(-10, 0, unsigned int, 0, true);
430	err |= TEST_ONE_SHIFT(-100, 0, s32, 0, true);
431	err |= TEST_ONE_SHIFT(-100, 0, u32, 0, true);
432	err |= TEST_ONE_SHIFT(-10000, 0, s64, 0, true);
433	err |= TEST_ONE_SHIFT(-10000, 0, u64, 0, true);
434
435	/* Nonsense: negative shift values. */
436	err |= TEST_ONE_SHIFT(0, -5, s8, 0, true);
437	err |= TEST_ONE_SHIFT(0, -5, u8, 0, true);
438	err |= TEST_ONE_SHIFT(0, -10, s16, 0, true);
439	err |= TEST_ONE_SHIFT(0, -10, u16, 0, true);
440	err |= TEST_ONE_SHIFT(0, -15, int, 0, true);
441	err |= TEST_ONE_SHIFT(0, -15, unsigned int, 0, true);
442	err |= TEST_ONE_SHIFT(0, -20, s32, 0, true);
443	err |= TEST_ONE_SHIFT(0, -20, u32, 0, true);
444	err |= TEST_ONE_SHIFT(0, -30, s64, 0, true);
445	err |= TEST_ONE_SHIFT(0, -30, u64, 0, true);
446
447	/* Overflow: shifted at or beyond entire type's bit width. */
448	err |= TEST_ONE_SHIFT(0, 8, u8, 0, true);
449	err |= TEST_ONE_SHIFT(0, 9, u8, 0, true);
450	err |= TEST_ONE_SHIFT(0, 8, s8, 0, true);
451	err |= TEST_ONE_SHIFT(0, 9, s8, 0, true);
452	err |= TEST_ONE_SHIFT(0, 16, u16, 0, true);
453	err |= TEST_ONE_SHIFT(0, 17, u16, 0, true);
454	err |= TEST_ONE_SHIFT(0, 16, s16, 0, true);
455	err |= TEST_ONE_SHIFT(0, 17, s16, 0, true);
456	err |= TEST_ONE_SHIFT(0, 32, u32, 0, true);
457	err |= TEST_ONE_SHIFT(0, 33, u32, 0, true);
458	err |= TEST_ONE_SHIFT(0, 32, int, 0, true);
459	err |= TEST_ONE_SHIFT(0, 33, int, 0, true);
460	err |= TEST_ONE_SHIFT(0, 32, s32, 0, true);
461	err |= TEST_ONE_SHIFT(0, 33, s32, 0, true);
462	err |= TEST_ONE_SHIFT(0, 64, u64, 0, true);
463	err |= TEST_ONE_SHIFT(0, 65, u64, 0, true);
464	err |= TEST_ONE_SHIFT(0, 64, s64, 0, true);
465	err |= TEST_ONE_SHIFT(0, 65, s64, 0, true);
466
467	/*
468	 * Corner case: for unsigned types, we fail when we've shifted
469	 * through the entire width of bits. For signed types, we might
470	 * want to match this behavior, but that would mean noticing if
471	 * we shift through all but the signed bit, and this is not
472	 * currently detected (but we'll notice an overflow into the
473	 * signed bit). So, for now, we will test this condition but
474	 * mark it as not expected to overflow.
475	 */
476	err |= TEST_ONE_SHIFT(0, 7, s8, 0, false);
477	err |= TEST_ONE_SHIFT(0, 15, s16, 0, false);
478	err |= TEST_ONE_SHIFT(0, 31, int, 0, false);
479	err |= TEST_ONE_SHIFT(0, 31, s32, 0, false);
480	err |= TEST_ONE_SHIFT(0, 63, s64, 0, false);
481
482	return err;
483}
484
485/*
486 * Deal with the various forms of allocator arguments. See comments above
487 * the DEFINE_TEST_ALLOC() instances for mapping of the "bits".
488 */
489#define alloc_GFP		 (GFP_KERNEL | __GFP_NOWARN)
490#define alloc010(alloc, arg, sz) alloc(sz, alloc_GFP)
491#define alloc011(alloc, arg, sz) alloc(sz, alloc_GFP, NUMA_NO_NODE)
492#define alloc000(alloc, arg, sz) alloc(sz)
493#define alloc001(alloc, arg, sz) alloc(sz, NUMA_NO_NODE)
494#define alloc110(alloc, arg, sz) alloc(arg, sz, alloc_GFP)
495#define free0(free, arg, ptr)	 free(ptr)
496#define free1(free, arg, ptr)	 free(arg, ptr)
497
498/* Wrap around to 16K */
499#define TEST_SIZE		(5 * 4096)
500
501#define DEFINE_TEST_ALLOC(func, free_func, want_arg, want_gfp, want_node)\
502static int __init test_ ## func (void *arg)				\
503{									\
504	volatile size_t a = TEST_SIZE;					\
505	volatile size_t b = (SIZE_MAX / TEST_SIZE) + 1;			\
506	void *ptr;							\
507									\
508	/* Tiny allocation test. */					\
509	ptr = alloc ## want_arg ## want_gfp ## want_node (func, arg, 1);\
510	if (!ptr) {							\
511		pr_warn(#func " failed regular allocation?!\n");	\
512		return 1;						\
513	}								\
514	free ## want_arg (free_func, arg, ptr);				\
515									\
516	/* Wrapped allocation test. */					\
517	ptr = alloc ## want_arg ## want_gfp ## want_node (func, arg,	\
518							  a * b);	\
519	if (!ptr) {							\
520		pr_warn(#func " unexpectedly failed bad wrapping?!\n");	\
521		return 1;						\
522	}								\
523	free ## want_arg (free_func, arg, ptr);				\
524									\
525	/* Saturated allocation test. */				\
526	ptr = alloc ## want_arg ## want_gfp ## want_node (func, arg,	\
527						   array_size(a, b));	\
528	if (ptr) {							\
529		pr_warn(#func " missed saturation!\n");			\
530		free ## want_arg (free_func, arg, ptr);			\
531		return 1;						\
532	}								\
533	pr_info(#func " detected saturation\n");			\
534	return 0;							\
535}
536
537/*
538 * Allocator uses a trailing node argument --------+  (e.g. kmalloc_node())
539 * Allocator uses the gfp_t argument -----------+  |  (e.g. kmalloc())
540 * Allocator uses a special leading argument +  |  |  (e.g. devm_kmalloc())
541 *                                           |  |  |
542 */
543DEFINE_TEST_ALLOC(kmalloc,	 kfree,	     0, 1, 0);
544DEFINE_TEST_ALLOC(kmalloc_node,	 kfree,	     0, 1, 1);
545DEFINE_TEST_ALLOC(kzalloc,	 kfree,	     0, 1, 0);
546DEFINE_TEST_ALLOC(kzalloc_node,  kfree,	     0, 1, 1);
547DEFINE_TEST_ALLOC(vmalloc,	 vfree,	     0, 0, 0);
548DEFINE_TEST_ALLOC(vmalloc_node,  vfree,	     0, 0, 1);
549DEFINE_TEST_ALLOC(vzalloc,	 vfree,	     0, 0, 0);
550DEFINE_TEST_ALLOC(vzalloc_node,  vfree,	     0, 0, 1);
551DEFINE_TEST_ALLOC(kvmalloc,	 kvfree,     0, 1, 0);
552DEFINE_TEST_ALLOC(kvmalloc_node, kvfree,     0, 1, 1);
553DEFINE_TEST_ALLOC(kvzalloc,	 kvfree,     0, 1, 0);
554DEFINE_TEST_ALLOC(kvzalloc_node, kvfree,     0, 1, 1);
555DEFINE_TEST_ALLOC(devm_kmalloc,  devm_kfree, 1, 1, 0);
556DEFINE_TEST_ALLOC(devm_kzalloc,  devm_kfree, 1, 1, 0);
557
558static int __init test_overflow_allocation(void)
559{
560	const char device_name[] = "overflow-test";
561	struct device *dev;
562	int err = 0;
563
564	/* Create dummy device for devm_kmalloc()-family tests. */
565	dev = root_device_register(device_name);
566	if (IS_ERR(dev)) {
567		pr_warn("Cannot register test device\n");
568		return 1;
569	}
570
571	err |= test_kmalloc(NULL);
572	err |= test_kmalloc_node(NULL);
573	err |= test_kzalloc(NULL);
574	err |= test_kzalloc_node(NULL);
575	err |= test_kvmalloc(NULL);
576	err |= test_kvmalloc_node(NULL);
577	err |= test_kvzalloc(NULL);
578	err |= test_kvzalloc_node(NULL);
579	err |= test_vmalloc(NULL);
580	err |= test_vmalloc_node(NULL);
581	err |= test_vzalloc(NULL);
582	err |= test_vzalloc_node(NULL);
583	err |= test_devm_kmalloc(dev);
584	err |= test_devm_kzalloc(dev);
585
586	device_unregister(dev);
587
588	return err;
589}
590
591static int __init test_module_init(void)
592{
593	int err = 0;
594
595	err |= test_overflow_calculation();
596	err |= test_overflow_shift();
597	err |= test_overflow_allocation();
598
599	if (err) {
600		pr_warn("FAIL!\n");
601		err = -EINVAL;
602	} else {
603		pr_info("all tests passed\n");
604	}
605
606	return err;
607}
608
609static void __exit test_module_exit(void)
610{ }
611
612module_init(test_module_init);
613module_exit(test_module_exit);
614MODULE_LICENSE("Dual MIT/GPL");