// 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");
