[linux.git] / lib / test_overflow.c

// SPDX-License-Identifier: GPL-2.0 OR MIT
/*
 * Test cases for arithmetic overflow checks.
 */
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/overflow.h>
#include <linux/types.h>

#define DEFINE_TEST_ARRAY(t)			\
	static const struct test_ ## t {	\
		t a, b;				\
		t sum, diff, prod;		\
		bool s_of, d_of, p_of;		\
	} t ## _tests[] __initconst

DEFINE_TEST_ARRAY(u8) = {
	{0, 0, 0, 0, 0, false, false, false},
	{1, 1, 2, 0, 1, false, false, false},
	{0, 1, 1, U8_MAX, 0, false, true, false},
	{1, 0, 1, 1, 0, false, false, false},
	{0, U8_MAX, U8_MAX, 1, 0, false, true, false},
	{U8_MAX, 0, U8_MAX, U8_MAX, 0, false, false, false},
	{1, U8_MAX, 0, 2, U8_MAX, true, true, false},
	{U8_MAX, 1, 0, U8_MAX-1, U8_MAX, true, false, false},
	{U8_MAX, U8_MAX, U8_MAX-1, 0, 1, true, false, true},

	{U8_MAX, U8_MAX-1, U8_MAX-2, 1, 2, true, false, true},
	{U8_MAX-1, U8_MAX, U8_MAX-2, U8_MAX, 2, true, true, true},

	{1U << 3, 1U << 3, 1U << 4, 0, 1U << 6, false, false, false},
	{1U << 4, 1U << 4, 1U << 5, 0, 0, false, false, true},
	{1U << 4, 1U << 3, 3*(1U << 3), 1U << 3, 1U << 7, false, false, false},
	{1U << 7, 1U << 7, 0, 0, 0, true, false, true},

	{48, 32, 80, 16, 0, false, false, true},
	{128, 128, 0, 0, 0, true, false, true},
	{123, 234, 101, 145, 110, true, true, true},
};
DEFINE_TEST_ARRAY(u16) = {
	{0, 0, 0, 0, 0, false, false, false},
	{1, 1, 2, 0, 1, false, false, false},
	{0, 1, 1, U16_MAX, 0, false, true, false},
	{1, 0, 1, 1, 0, false, false, false},
	{0, U16_MAX, U16_MAX, 1, 0, false, true, false},
	{U16_MAX, 0, U16_MAX, U16_MAX, 0, false, false, false},
	{1, U16_MAX, 0, 2, U16_MAX, true, true, false},
	{U16_MAX, 1, 0, U16_MAX-1, U16_MAX, true, false, false},
	{U16_MAX, U16_MAX, U16_MAX-1, 0, 1, true, false, true},

	{U16_MAX, U16_MAX-1, U16_MAX-2, 1, 2, true, false, true},
	{U16_MAX-1, U16_MAX, U16_MAX-2, U16_MAX, 2, true, true, true},

	{1U << 7, 1U << 7, 1U << 8, 0, 1U << 14, false, false, false},
	{1U << 8, 1U << 8, 1U << 9, 0, 0, false, false, true},
	{1U << 8, 1U << 7, 3*(1U << 7), 1U << 7, 1U << 15, false, false, false},
	{1U << 15, 1U << 15, 0, 0, 0, true, false, true},

	{123, 234, 357, 65425, 28782, false, true, false},
	{1234, 2345, 3579, 64425, 10146, false, true, true},
};
DEFINE_TEST_ARRAY(u32) = {
	{0, 0, 0, 0, 0, false, false, false},
	{1, 1, 2, 0, 1, false, false, false},
	{0, 1, 1, U32_MAX, 0, false, true, false},
	{1, 0, 1, 1, 0, false, false, false},
	{0, U32_MAX, U32_MAX, 1, 0, false, true, false},
	{U32_MAX, 0, U32_MAX, U32_MAX, 0, false, false, false},
	{1, U32_MAX, 0, 2, U32_MAX, true, true, false},
	{U32_MAX, 1, 0, U32_MAX-1, U32_MAX, true, false, false},
	{U32_MAX, U32_MAX, U32_MAX-1, 0, 1, true, false, true},

	{U32_MAX, U32_MAX-1, U32_MAX-2, 1, 2, true, false, true},
	{U32_MAX-1, U32_MAX, U32_MAX-2, U32_MAX, 2, true, true, true},

	{1U << 15, 1U << 15, 1U << 16, 0, 1U << 30, false, false, false},
	{1U << 16, 1U << 16, 1U << 17, 0, 0, false, false, true},
	{1U << 16, 1U << 15, 3*(1U << 15), 1U << 15, 1U << 31, false, false, false},
	{1U << 31, 1U << 31, 0, 0, 0, true, false, true},

	{-2U, 1U, -1U, -3U, -2U, false, false, false},
	{-4U, 5U, 1U, -9U, -20U, true, false, true},
};

DEFINE_TEST_ARRAY(u64) = {
	{0, 0, 0, 0, 0, false, false, false},
	{1, 1, 2, 0, 1, false, false, false},
	{0, 1, 1, U64_MAX, 0, false, true, false},
	{1, 0, 1, 1, 0, false, false, false},
	{0, U64_MAX, U64_MAX, 1, 0, false, true, false},
	{U64_MAX, 0, U64_MAX, U64_MAX, 0, false, false, false},
	{1, U64_MAX, 0, 2, U64_MAX, true, true, false},
	{U64_MAX, 1, 0, U64_MAX-1, U64_MAX, true, false, false},
	{U64_MAX, U64_MAX, U64_MAX-1, 0, 1, true, false, true},

	{U64_MAX, U64_MAX-1, U64_MAX-2, 1, 2, true, false, true},
	{U64_MAX-1, U64_MAX, U64_MAX-2, U64_MAX, 2, true, true, true},

	{1ULL << 31, 1ULL << 31, 1ULL << 32, 0, 1ULL << 62, false, false, false},
	{1ULL << 32, 1ULL << 32, 1ULL << 33, 0, 0, false, false, true},
	{1ULL << 32, 1ULL << 31, 3*(1ULL << 31), 1ULL << 31, 1ULL << 63, false, false, false},
	{1ULL << 63, 1ULL << 63, 0, 0, 0, true, false, true},
	{1000000000ULL /* 10^9 */, 10000000000ULL /* 10^10 */,
	 11000000000ULL, 18446744064709551616ULL, 10000000000000000000ULL,
	 false, true, false},
	{-15ULL, 10ULL, -5ULL, -25ULL, -150ULL, false, false, true},
};

DEFINE_TEST_ARRAY(s8) = {
	{0, 0, 0, 0, 0, false, false, false},

	{0, S8_MAX, S8_MAX, -S8_MAX, 0, false, false, false},
	{S8_MAX, 0, S8_MAX, S8_MAX, 0, false, false, false},
	{0, S8_MIN, S8_MIN, S8_MIN, 0, false, true, false},
	{S8_MIN, 0, S8_MIN, S8_MIN, 0, false, false, false},

	{-1, S8_MIN, S8_MAX, S8_MAX, S8_MIN, true, false, true},
	{S8_MIN, -1, S8_MAX, -S8_MAX, S8_MIN, true, false, true},
	{-1, S8_MAX, S8_MAX-1, S8_MIN, -S8_MAX, false, false, false},
	{S8_MAX, -1, S8_MAX-1, S8_MIN, -S8_MAX, false, true, false},
	{-1, -S8_MAX, S8_MIN, S8_MAX-1, S8_MAX, false, false, false},
	{-S8_MAX, -1, S8_MIN, S8_MIN+2, S8_MAX, false, false, false},

	{1, S8_MIN, -S8_MAX, -S8_MAX, S8_MIN, false, true, false},
	{S8_MIN, 1, -S8_MAX, S8_MAX, S8_MIN, false, true, false},
	{1, S8_MAX, S8_MIN, S8_MIN+2, S8_MAX, true, false, false},
	{S8_MAX, 1, S8_MIN, S8_MAX-1, S8_MAX, true, false, false},

	{S8_MIN, S8_MIN, 0, 0, 0, true, false, true},
	{S8_MAX, S8_MAX, -2, 0, 1, true, false, true},

	{-4, -32, -36, 28, -128, false, false, true},
	{-4, 32, 28, -36, -128, false, false, false},
};

DEFINE_TEST_ARRAY(s16) = {
	{0, 0, 0, 0, 0, false, false, false},

	{0, S16_MAX, S16_MAX, -S16_MAX, 0, false, false, false},
	{S16_MAX, 0, S16_MAX, S16_MAX, 0, false, false, false},
	{0, S16_MIN, S16_MIN, S16_MIN, 0, false, true, false},
	{S16_MIN, 0, S16_MIN, S16_MIN, 0, false, false, false},

	{-1, S16_MIN, S16_MAX, S16_MAX, S16_MIN, true, false, true},
	{S16_MIN, -1, S16_MAX, -S16_MAX, S16_MIN, true, false, true},
	{-1, S16_MAX, S16_MAX-1, S16_MIN, -S16_MAX, false, false, false},
	{S16_MAX, -1, S16_MAX-1, S16_MIN, -S16_MAX, false, true, false},
	{-1, -S16_MAX, S16_MIN, S16_MAX-1, S16_MAX, false, false, false},
	{-S16_MAX, -1, S16_MIN, S16_MIN+2, S16_MAX, false, false, false},

	{1, S16_MIN, -S16_MAX, -S16_MAX, S16_MIN, false, true, false},
	{S16_MIN, 1, -S16_MAX, S16_MAX, S16_MIN, false, true, false},
	{1, S16_MAX, S16_MIN, S16_MIN+2, S16_MAX, true, false, false},
	{S16_MAX, 1, S16_MIN, S16_MAX-1, S16_MAX, true, false, false},

	{S16_MIN, S16_MIN, 0, 0, 0, true, false, true},
	{S16_MAX, S16_MAX, -2, 0, 1, true, false, true},
};
DEFINE_TEST_ARRAY(s32) = {
	{0, 0, 0, 0, 0, false, false, false},

	{0, S32_MAX, S32_MAX, -S32_MAX, 0, false, false, false},
	{S32_MAX, 0, S32_MAX, S32_MAX, 0, false, false, false},
	{0, S32_MIN, S32_MIN, S32_MIN, 0, false, true, false},
	{S32_MIN, 0, S32_MIN, S32_MIN, 0, false, false, false},

	{-1, S32_MIN, S32_MAX, S32_MAX, S32_MIN, true, false, true},
	{S32_MIN, -1, S32_MAX, -S32_MAX, S32_MIN, true, false, true},
	{-1, S32_MAX, S32_MAX-1, S32_MIN, -S32_MAX, false, false, false},
	{S32_MAX, -1, S32_MAX-1, S32_MIN, -S32_MAX, false, true, false},
	{-1, -S32_MAX, S32_MIN, S32_MAX-1, S32_MAX, false, false, false},
	{-S32_MAX, -1, S32_MIN, S32_MIN+2, S32_MAX, false, false, false},

	{1, S32_MIN, -S32_MAX, -S32_MAX, S32_MIN, false, true, false},
	{S32_MIN, 1, -S32_MAX, S32_MAX, S32_MIN, false, true, false},
	{1, S32_MAX, S32_MIN, S32_MIN+2, S32_MAX, true, false, false},
	{S32_MAX, 1, S32_MIN, S32_MAX-1, S32_MAX, true, false, false},

	{S32_MIN, S32_MIN, 0, 0, 0, true, false, true},
	{S32_MAX, S32_MAX, -2, 0, 1, true, false, true},
};
DEFINE_TEST_ARRAY(s64) = {
	{0, 0, 0, 0, 0, false, false, false},

	{0, S64_MAX, S64_MAX, -S64_MAX, 0, false, false, false},
	{S64_MAX, 0, S64_MAX, S64_MAX, 0, false, false, false},
	{0, S64_MIN, S64_MIN, S64_MIN, 0, false, true, false},
	{S64_MIN, 0, S64_MIN, S64_MIN, 0, false, false, false},

	{-1, S64_MIN, S64_MAX, S64_MAX, S64_MIN, true, false, true},
	{S64_MIN, -1, S64_MAX, -S64_MAX, S64_MIN, true, false, true},
	{-1, S64_MAX, S64_MAX-1, S64_MIN, -S64_MAX, false, false, false},
	{S64_MAX, -1, S64_MAX-1, S64_MIN, -S64_MAX, false, true, false},
	{-1, -S64_MAX, S64_MIN, S64_MAX-1, S64_MAX, false, false, false},
	{-S64_MAX, -1, S64_MIN, S64_MIN+2, S64_MAX, false, false, false},

	{1, S64_MIN, -S64_MAX, -S64_MAX, S64_MIN, false, true, false},
	{S64_MIN, 1, -S64_MAX, S64_MAX, S64_MIN, false, true, false},
	{1, S64_MAX, S64_MIN, S64_MIN+2, S64_MAX, true, false, false},
	{S64_MAX, 1, S64_MIN, S64_MAX-1, S64_MAX, true, false, false},

	{S64_MIN, S64_MIN, 0, 0, 0, true, false, true},
	{S64_MAX, S64_MAX, -2, 0, 1, true, false, true},

	{-1, -1, -2, 0, 1, false, false, false},
	{-1, -128, -129, 127, 128, false, false, false},
	{-128, -1, -129, -127, 128, false, false, false},
	{0, -S64_MAX, -S64_MAX, S64_MAX, 0, false, false, false},
};

#define check_one_op(t, fmt, op, sym, a, b, r, of) do {		\
	t _r;							\
	bool _of;						\
								\
	_of = check_ ## op ## _overflow(a, b, &_r);		\
	if (_of != of) {					\
		pr_warn("expected "fmt" "sym" "fmt		\
			" to%s overflow (type %s)\n",		\
			a, b, of ? "" : " not", #t);		\
		err = 1;					\
	}							\
	if (_r != r) {						\
		pr_warn("expected "fmt" "sym" "fmt" == "	\
			fmt", got "fmt" (type %s)\n",		\
			a, b, r, _r, #t);			\
		err = 1;					\
	}							\
} while (0)

#define DEFINE_TEST_FUNC(t, fmt)					\
static int __init do_test_ ## t(const struct test_ ## t *p)		\
{							   		\
	int err = 0;							\
									\
	check_one_op(t, fmt, add, "+", p->a, p->b, p->sum, p->s_of);	\
	check_one_op(t, fmt, add, "+", p->b, p->a, p->sum, p->s_of);	\
	check_one_op(t, fmt, sub, "-", p->a, p->b, p->diff, p->d_of);	\
	check_one_op(t, fmt, mul, "*", p->a, p->b, p->prod, p->p_of);	\
	check_one_op(t, fmt, mul, "*", p->b, p->a, p->prod, p->p_of);	\
									\
	return err;							\
}									\
									\
static int __init test_ ## t ## _overflow(void) {			\
	int err = 0;							\
	unsigned i;							\
									\
	pr_info("%-3s: %zu tests\n", #t, ARRAY_SIZE(t ## _tests));	\
	for (i = 0; i < ARRAY_SIZE(t ## _tests); ++i)			\
		err |= do_test_ ## t(&t ## _tests[i]);			\
	return err;							\
}

DEFINE_TEST_FUNC(u8, "%d");
DEFINE_TEST_FUNC(s8, "%d");
DEFINE_TEST_FUNC(u16, "%d");
DEFINE_TEST_FUNC(s16, "%d");
DEFINE_TEST_FUNC(u32, "%u");
DEFINE_TEST_FUNC(s32, "%d");
#if BITS_PER_LONG == 64
DEFINE_TEST_FUNC(u64, "%llu");
DEFINE_TEST_FUNC(s64, "%lld");
#endif

static int __init test_overflow_calculation(void)
{
	int err = 0;

	err |= test_u8_overflow();
	err |= test_s8_overflow();
	err |= test_u16_overflow();
	err |= test_s16_overflow();
	err |= test_u32_overflow();
	err |= test_s32_overflow();
#if BITS_PER_LONG == 64
	err |= test_u64_overflow();
	err |= test_s64_overflow();
#endif

	return err;
}

static int __init test_module_init(void)
{
	int err = 0;

	err |= test_overflow_calculation();

	if (err) {
		pr_warn("FAIL!\n");
		err = -EINVAL;
	} else {
		pr_info("all tests passed\n");
	}

	return err;
}

static void __exit test_module_exit(void)
{ }

module_init(test_module_init);
module_exit(test_module_exit);
MODULE_LICENSE("Dual MIT/GPL");
Commit	Line	Data
455a35a6 RV	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/init.h>
	8	#include <linux/kernel.h>
	9	#include <linux/module.h>
	10	#include <linux/overflow.h>
	11	#include <linux/types.h>
	12
	13	#define DEFINE_TEST_ARRAY(t) \
	14	static const struct test_ ## t { \
	15	t a, b; \
	16	t sum, diff, prod; \
	17	bool s_of, d_of, p_of; \
	18	} t ## _tests[] __initconst
	19
	20	DEFINE_TEST_ARRAY(u8) = {
	21	{0, 0, 0, 0, 0, false, false, false},
	22	{1, 1, 2, 0, 1, false, false, false},
	23	{0, 1, 1, U8_MAX, 0, false, true, false},
	24	{1, 0, 1, 1, 0, false, false, false},
	25	{0, U8_MAX, U8_MAX, 1, 0, false, true, false},
	26	{U8_MAX, 0, U8_MAX, U8_MAX, 0, false, false, false},
	27	{1, U8_MAX, 0, 2, U8_MAX, true, true, false},
	28	{U8_MAX, 1, 0, U8_MAX-1, U8_MAX, true, false, false},
	29	{U8_MAX, U8_MAX, U8_MAX-1, 0, 1, true, false, true},
	30
	31	{U8_MAX, U8_MAX-1, U8_MAX-2, 1, 2, true, false, true},
	32	{U8_MAX-1, U8_MAX, U8_MAX-2, U8_MAX, 2, true, true, true},
	33
	34	{1U << 3, 1U << 3, 1U << 4, 0, 1U << 6, false, false, false},
	35	{1U << 4, 1U << 4, 1U << 5, 0, 0, false, false, true},
	36	{1U << 4, 1U << 3, 3*(1U << 3), 1U << 3, 1U << 7, false, false, false},
	37	{1U << 7, 1U << 7, 0, 0, 0, true, false, true},
	38
	39	{48, 32, 80, 16, 0, false, false, true},
	40	{128, 128, 0, 0, 0, true, false, true},
	41	{123, 234, 101, 145, 110, true, true, true},
	42	};
	43	DEFINE_TEST_ARRAY(u16) = {
	44	{0, 0, 0, 0, 0, false, false, false},
	45	{1, 1, 2, 0, 1, false, false, false},
	46	{0, 1, 1, U16_MAX, 0, false, true, false},
	47	{1, 0, 1, 1, 0, false, false, false},
	48	{0, U16_MAX, U16_MAX, 1, 0, false, true, false},
	49	{U16_MAX, 0, U16_MAX, U16_MAX, 0, false, false, false},
	50	{1, U16_MAX, 0, 2, U16_MAX, true, true, false},
	51	{U16_MAX, 1, 0, U16_MAX-1, U16_MAX, true, false, false},
	52	{U16_MAX, U16_MAX, U16_MAX-1, 0, 1, true, false, true},
	53
	54	{U16_MAX, U16_MAX-1, U16_MAX-2, 1, 2, true, false, true},
	55	{U16_MAX-1, U16_MAX, U16_MAX-2, U16_MAX, 2, true, true, true},
	56
	57	{1U << 7, 1U << 7, 1U << 8, 0, 1U << 14, false, false, false},
	58	{1U << 8, 1U << 8, 1U << 9, 0, 0, false, false, true},
	59	{1U << 8, 1U << 7, 3*(1U << 7), 1U << 7, 1U << 15, false, false, false},
	60	{1U << 15, 1U << 15, 0, 0, 0, true, false, true},
	61
	62	{123, 234, 357, 65425, 28782, false, true, false},
	63	{1234, 2345, 3579, 64425, 10146, false, true, true},
	64	};
65	DEFINE_TEST_ARRAY(u32) = {
66	{0, 0, 0, 0, 0, false, false, false},
67	{1, 1, 2, 0, 1, false, false, false},
68	{0, 1, 1, U32_MAX, 0, false, true, false},
69	{1, 0, 1, 1, 0, false, false, false},
70	{0, U32_MAX, U32_MAX, 1, 0, false, true, false},
71	{U32_MAX, 0, U32_MAX, U32_MAX, 0, false, false, false},
72	{1, U32_MAX, 0, 2, U32_MAX, true, true, false},
73	{U32_MAX, 1, 0, U32_MAX-1, U32_MAX, true, false, false},
74	{U32_MAX, U32_MAX, U32_MAX-1, 0, 1, true, false, true},
75
76	{U32_MAX, U32_MAX-1, U32_MAX-2, 1, 2, true, false, true},
77	{U32_MAX-1, U32_MAX, U32_MAX-2, U32_MAX, 2, true, true, true},
78
79	{1U << 15, 1U << 15, 1U << 16, 0, 1U << 30, false, false, false},
80	{1U << 16, 1U << 16, 1U << 17, 0, 0, false, false, true},
81	{1U << 16, 1U << 15, 3*(1U << 15), 1U << 15, 1U << 31, false, false, false},
82	{1U << 31, 1U << 31, 0, 0, 0, true, false, true},
83
84	{-2U, 1U, -1U, -3U, -2U, false, false, false},
85	{-4U, 5U, 1U, -9U, -20U, true, false, true},
86	};
87
88	DEFINE_TEST_ARRAY(u64) = {
89	{0, 0, 0, 0, 0, false, false, false},
90	{1, 1, 2, 0, 1, false, false, false},
91	{0, 1, 1, U64_MAX, 0, false, true, false},
92	{1, 0, 1, 1, 0, false, false, false},
93	{0, U64_MAX, U64_MAX, 1, 0, false, true, false},
94	{U64_MAX, 0, U64_MAX, U64_MAX, 0, false, false, false},
95	{1, U64_MAX, 0, 2, U64_MAX, true, true, false},
96	{U64_MAX, 1, 0, U64_MAX-1, U64_MAX, true, false, false},
97	{U64_MAX, U64_MAX, U64_MAX-1, 0, 1, true, false, true},
98
99	{U64_MAX, U64_MAX-1, U64_MAX-2, 1, 2, true, false, true},
100	{U64_MAX-1, U64_MAX, U64_MAX-2, U64_MAX, 2, true, true, true},
101
102	{1ULL << 31, 1ULL << 31, 1ULL << 32, 0, 1ULL << 62, false, false, false},
103	{1ULL << 32, 1ULL << 32, 1ULL << 33, 0, 0, false, false, true},
104	{1ULL << 32, 1ULL << 31, 3*(1ULL << 31), 1ULL << 31, 1ULL << 63, false, false, false},
105	{1ULL << 63, 1ULL << 63, 0, 0, 0, true, false, true},
106	{1000000000ULL /* 10^9 /, 10000000000ULL / 10^10 */,
107	11000000000ULL, 18446744064709551616ULL, 10000000000000000000ULL,
108	false, true, false},
109	{-15ULL, 10ULL, -5ULL, -25ULL, -150ULL, false, false, true},
110	};
111
112	DEFINE_TEST_ARRAY(s8) = {
113	{0, 0, 0, 0, 0, false, false, false},
114
115	{0, S8_MAX, S8_MAX, -S8_MAX, 0, false, false, false},
116	{S8_MAX, 0, S8_MAX, S8_MAX, 0, false, false, false},
117	{0, S8_MIN, S8_MIN, S8_MIN, 0, false, true, false},
118	{S8_MIN, 0, S8_MIN, S8_MIN, 0, false, false, false},
119
120	{-1, S8_MIN, S8_MAX, S8_MAX, S8_MIN, true, false, true},
121	{S8_MIN, -1, S8_MAX, -S8_MAX, S8_MIN, true, false, true},
122	{-1, S8_MAX, S8_MAX-1, S8_MIN, -S8_MAX, false, false, false},
123	{S8_MAX, -1, S8_MAX-1, S8_MIN, -S8_MAX, false, true, false},
124	{-1, -S8_MAX, S8_MIN, S8_MAX-1, S8_MAX, false, false, false},
125	{-S8_MAX, -1, S8_MIN, S8_MIN+2, S8_MAX, false, false, false},
126
127	{1, S8_MIN, -S8_MAX, -S8_MAX, S8_MIN, false, true, false},
128	{S8_MIN, 1, -S8_MAX, S8_MAX, S8_MIN, false, true, false},
129	{1, S8_MAX, S8_MIN, S8_MIN+2, S8_MAX, true, false, false},
130	{S8_MAX, 1, S8_MIN, S8_MAX-1, S8_MAX, true, false, false},
131
132	{S8_MIN, S8_MIN, 0, 0, 0, true, false, true},
133	{S8_MAX, S8_MAX, -2, 0, 1, true, false, true},
134
135	{-4, -32, -36, 28, -128, false, false, true},
136	{-4, 32, 28, -36, -128, false, false, false},
137	};
138
139	DEFINE_TEST_ARRAY(s16) = {
140	{0, 0, 0, 0, 0, false, false, false},
141
142	{0, S16_MAX, S16_MAX, -S16_MAX, 0, false, false, false},
143	{S16_MAX, 0, S16_MAX, S16_MAX, 0, false, false, false},
144	{0, S16_MIN, S16_MIN, S16_MIN, 0, false, true, false},
145	{S16_MIN, 0, S16_MIN, S16_MIN, 0, false, false, false},
146
147	{-1, S16_MIN, S16_MAX, S16_MAX, S16_MIN, true, false, true},
148	{S16_MIN, -1, S16_MAX, -S16_MAX, S16_MIN, true, false, true},
149	{-1, S16_MAX, S16_MAX-1, S16_MIN, -S16_MAX, false, false, false},
150	{S16_MAX, -1, S16_MAX-1, S16_MIN, -S16_MAX, false, true, false},
151	{-1, -S16_MAX, S16_MIN, S16_MAX-1, S16_MAX, false, false, false},
152	{-S16_MAX, -1, S16_MIN, S16_MIN+2, S16_MAX, false, false, false},
153
154	{1, S16_MIN, -S16_MAX, -S16_MAX, S16_MIN, false, true, false},
155	{S16_MIN, 1, -S16_MAX, S16_MAX, S16_MIN, false, true, false},
156	{1, S16_MAX, S16_MIN, S16_MIN+2, S16_MAX, true, false, false},
157	{S16_MAX, 1, S16_MIN, S16_MAX-1, S16_MAX, true, false, false},
158
159	{S16_MIN, S16_MIN, 0, 0, 0, true, false, true},
160	{S16_MAX, S16_MAX, -2, 0, 1, true, false, true},
161	};
162	DEFINE_TEST_ARRAY(s32) = {
163	{0, 0, 0, 0, 0, false, false, false},
164
165	{0, S32_MAX, S32_MAX, -S32_MAX, 0, false, false, false},
166	{S32_MAX, 0, S32_MAX, S32_MAX, 0, false, false, false},
167	{0, S32_MIN, S32_MIN, S32_MIN, 0, false, true, false},
168	{S32_MIN, 0, S32_MIN, S32_MIN, 0, false, false, false},
169
170	{-1, S32_MIN, S32_MAX, S32_MAX, S32_MIN, true, false, true},
171	{S32_MIN, -1, S32_MAX, -S32_MAX, S32_MIN, true, false, true},
172	{-1, S32_MAX, S32_MAX-1, S32_MIN, -S32_MAX, false, false, false},
173	{S32_MAX, -1, S32_MAX-1, S32_MIN, -S32_MAX, false, true, false},
174	{-1, -S32_MAX, S32_MIN, S32_MAX-1, S32_MAX, false, false, false},
175	{-S32_MAX, -1, S32_MIN, S32_MIN+2, S32_MAX, false, false, false},
176
177	{1, S32_MIN, -S32_MAX, -S32_MAX, S32_MIN, false, true, false},
178	{S32_MIN, 1, -S32_MAX, S32_MAX, S32_MIN, false, true, false},
179	{1, S32_MAX, S32_MIN, S32_MIN+2, S32_MAX, true, false, false},
180	{S32_MAX, 1, S32_MIN, S32_MAX-1, S32_MAX, true, false, false},
181
182	{S32_MIN, S32_MIN, 0, 0, 0, true, false, true},
183	{S32_MAX, S32_MAX, -2, 0, 1, true, false, true},
184	};
185	DEFINE_TEST_ARRAY(s64) = {
186	{0, 0, 0, 0, 0, false, false, false},
187
188	{0, S64_MAX, S64_MAX, -S64_MAX, 0, false, false, false},
189	{S64_MAX, 0, S64_MAX, S64_MAX, 0, false, false, false},
190	{0, S64_MIN, S64_MIN, S64_MIN, 0, false, true, false},
191	{S64_MIN, 0, S64_MIN, S64_MIN, 0, false, false, false},
192
193	{-1, S64_MIN, S64_MAX, S64_MAX, S64_MIN, true, false, true},
194	{S64_MIN, -1, S64_MAX, -S64_MAX, S64_MIN, true, false, true},
195	{-1, S64_MAX, S64_MAX-1, S64_MIN, -S64_MAX, false, false, false},
196	{S64_MAX, -1, S64_MAX-1, S64_MIN, -S64_MAX, false, true, false},
197	{-1, -S64_MAX, S64_MIN, S64_MAX-1, S64_MAX, false, false, false},
198	{-S64_MAX, -1, S64_MIN, S64_MIN+2, S64_MAX, false, false, false},
199
200	{1, S64_MIN, -S64_MAX, -S64_MAX, S64_MIN, false, true, false},
201	{S64_MIN, 1, -S64_MAX, S64_MAX, S64_MIN, false, true, false},
202	{1, S64_MAX, S64_MIN, S64_MIN+2, S64_MAX, true, false, false},
203	{S64_MAX, 1, S64_MIN, S64_MAX-1, S64_MAX, true, false, false},
204
205	{S64_MIN, S64_MIN, 0, 0, 0, true, false, true},
206	{S64_MAX, S64_MAX, -2, 0, 1, true, false, true},
207
208	{-1, -1, -2, 0, 1, false, false, false},
209	{-1, -128, -129, 127, 128, false, false, false},
210	{-128, -1, -129, -127, 128, false, false, false},
211	{0, -S64_MAX, -S64_MAX, S64_MAX, 0, false, false, false},
212	};
213
6d334432 RV	214	#define check_one_op(t, fmt, op, sym, a, b, r, of) do { \
	215	t _r; \
	216	bool _of; \
	217	\
	218	_of = check_ ## op ## _overflow(a, b, &_r); \
	219	if (_of != of) { \
	220	pr_warn("expected "fmt" "sym" "fmt \
	221	" to%s overflow (type %s)\n", \
	222	a, b, of ? "" : " not", #t); \
8fee81aa	223	err = 1; \
6d334432 RV	224	} \
	225	if (_r != r) { \
	226	pr_warn("expected "fmt" "sym" "fmt" == " \
	227	fmt", got "fmt" (type %s)\n", \
	228	a, b, r, _r, #t); \
8fee81aa	229	err = 1; \
6d334432 RV	230	} \
	231	} while (0)
	232
455a35a6	233	#define DEFINE_TEST_FUNC(t, fmt) \
8fee81aa	234	static int __init do_test_ ## t(const struct test_ ## t *p) \
455a35a6	235	{ \
8fee81aa KC	236	int err = 0; \
8fee81aa KC	237	\
6d334432 RV	238	check_one_op(t, fmt, add, "+", p->a, p->b, p->sum, p->s_of); \
	239	check_one_op(t, fmt, add, "+", p->b, p->a, p->sum, p->s_of); \
	240	check_one_op(t, fmt, sub, "-", p->a, p->b, p->diff, p->d_of); \
	241	check_one_op(t, fmt, mul, "*", p->a, p->b, p->prod, p->p_of); \
	242	check_one_op(t, fmt, mul, "*", p->b, p->a, p->prod, p->p_of); \
8fee81aa KC	243	\
8fee81aa KC	244	return err; \
455a35a6 RV	245	} \
455a35a6 RV	246	\
8fee81aa KC	247	static int __init test_ ## t ## _overflow(void) { \
8fee81aa KC	248	int err = 0; \
455a35a6 RV	249	unsigned i; \
	250	\
	251	pr_info("%-3s: %zu tests\n", #t, ARRAY_SIZE(t ## _tests)); \
	252	for (i = 0; i < ARRAY_SIZE(t ## _tests); ++i) \
8fee81aa KC	253	err \|= do_test_ ## t(&t ## _tests[i]); \
8fee81aa KC	254	return err; \
455a35a6 RV	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
8fee81aa	268	static int __init test_overflow_calculation(void)
455a35a6	269	{
8fee81aa KC	270	int err = 0;
	271
	272	err \|= test_u8_overflow();
	273	err \|= test_s8_overflow();
	274	err \|= test_u16_overflow();
	275	err \|= test_s16_overflow();
	276	err \|= test_u32_overflow();
	277	err \|= test_s32_overflow();
455a35a6	278	#if BITS_PER_LONG == 64
8fee81aa KC	279	err \|= test_u64_overflow();
8fee81aa KC	280	err \|= test_s64_overflow();
455a35a6 RV	281	#endif
455a35a6 RV	282
8fee81aa KC	283	return err;
	284	}
	285
	286	static int __init test_module_init(void)
	287	{
	288	int err = 0;
	289
	290	err \|= test_overflow_calculation();
	291
	292	if (err) {
	293	pr_warn("FAIL!\n");
	294	err = -EINVAL;
	295	} else {
	296	pr_info("all tests passed\n");
	297	}
455a35a6	298
8fee81aa	299	return err;
455a35a6 RV	300	}
	301
	302	static void __exit test_module_exit(void)
	303	{ }
	304
8fee81aa	305	module_init(test_module_init);
455a35a6 RV	306	module_exit(test_module_exit);
455a35a6 RV	307	MODULE_LICENSE("Dual MIT/GPL");