path: root/lib/overflow_kunit.c

// SPDX-License-Identifier: GPL-2.0 OR MIT
/*
 * Test cases for arithmetic overflow checks. See:
 * "Running tests with kunit_tool" at Documentation/dev-tools/kunit/start.rst
 *	./tools/testing/kunit/kunit.py run overflow [--raw_output]
 */
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <kunit/test.h>
#include <linux/device.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/module.h>
#include <linux/overflow.h>
#include <linux/slab.h>
#include <linux/types.h>
#include <linux/vmalloc.h>

#define SKIP(cond, reason)		do {			\
	if (cond) {						\
		kunit_skip(test, reason);			\
		return;						\
	}							\
} while (0)

/*
 * Clang 11 and earlier generate unwanted libcalls for signed output
 * on unsigned input.
 */
#if defined(CONFIG_CC_IS_CLANG) && __clang_major__ <= 11
# define SKIP_SIGN_MISMATCH(t)	SKIP(t, "Clang 11 unwanted libcalls")
#else
# define SKIP_SIGN_MISMATCH(t)	do { } while (0)
#endif

/*
 * Clang 13 and earlier generate unwanted libcalls for 64-bit tests on
 * 32-bit hosts.
 */
#if defined(CONFIG_CC_IS_CLANG) && __clang_major__ <= 13 &&	\
    BITS_PER_LONG != 64
# define SKIP_64_ON_32(t)	SKIP(t, "Clang 13 unwanted libcalls")
#else
# define SKIP_64_ON_32(t)	do { } while (0)
#endif

#define DEFINE_TEST_ARRAY_TYPED(t1, t2, t)			\
	static const struct test_ ## t1 ## _ ## t2 ## __ ## t {	\
		t1 a;						\
		t2 b;						\
		t sum, diff, prod;				\
		bool s_of, d_of, p_of;				\
	} t1 ## _ ## t2 ## __ ## t ## _tests[]

#define DEFINE_TEST_ARRAY(t)	DEFINE_TEST_ARRAY_TYPED(t, t, t)

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,