https://github.com/torvalds/linux
Revision 641e3fd1a038c68045bbf89d78502f4b4bbc7284 authored by Uwe Kleine-König on 19 October 2021, 20:49:16 UTC, committed by David S. Miller on 20 October 2021, 13:41:20 UTC
If something goes wrong in the remove callback, returning an error code
just results in an error message. The device still disappears.

So don't skip disabling the regulator in st95hf_remove() if resetting
the controller via spi fails. Also don't return an error code which just
results in two error messages.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
1 parent 323e9a9
Raw File
Tip revision: 641e3fd1a038c68045bbf89d78502f4b4bbc7284 authored by Uwe Kleine-König on 19 October 2021, 20:49:16 UTC
nfc: st95hf: Make spi remove() callback return zero
Tip revision: 641e3fd
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/device.h>
#include <linux/init.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 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 arithmetic 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_overflow_shift(void)
{
	int err = 0;

/* Args are: value, shift, type, expected result, overflow expected */
#define TEST_ONE_SHIFT(a, s, t, expect, of) ({				\
	int __failed = 0;						\
	typeof(a) __a = (a);						\
	typeof(s) __s = (s);						\
	t __e = (expect);						\
	t __d;								\
	bool __of = check_shl_overflow(__a, __s, &__d);			\
	if (__of != of) {						\
		pr_warn("expected (%s)(%s << %s) to%s overflow\n",	\
			#t, #a, #s, of ? "" : " not");			\
		__failed = 1;						\
	} else if (!__of && __d != __e) {				\
		pr_warn("expected (%s)(%s << %s) == %s\n",		\
			#t, #a, #s, #expect);				\
		if ((t)-1 < 0)						\
			pr_warn("got %lld\n", (s64)__d);		\
		else							\
			pr_warn("got %llu\n", (u64)__d);		\
		__failed = 1;						\
	}								\
	if (!__failed)							\
		pr_info("ok: (%s)(%s << %s) == %s\n", #t, #a, #s,	\
			of ? "overflow" : #expect);			\
	__failed;							\
})

	/* Sane shifts. */
	err |= TEST_ONE_SHIFT(1, 0, u8, 1 << 0, false);
	err |= TEST_ONE_SHIFT(1, 4, u8, 1 << 4, false);
	err |= TEST_ONE_SHIFT(1, 7, u8, 1 << 7, false);
	err |= TEST_ONE_SHIFT(0xF, 4, u8, 0xF << 4, false);
	err |= TEST_ONE_SHIFT(1, 0, u16, 1 << 0, false);
	err |= TEST_ONE_SHIFT(1, 10, u16, 1 << 10, false);
	err |= TEST_ONE_SHIFT(1, 15, u16, 1 << 15, false);
	err |= TEST_ONE_SHIFT(0xFF, 8, u16, 0xFF << 8, false);
	err |= TEST_ONE_SHIFT(1, 0, int, 1 << 0, false);
	err |= TEST_ONE_SHIFT(1, 16, int, 1 << 16, false);
	err |= TEST_ONE_SHIFT(1, 30, int, 1 << 30, false);
	err |= TEST_ONE_SHIFT(1, 0, s32, 1 << 0, false);
	err |= TEST_ONE_SHIFT(1, 16, s32, 1 << 16, false);
	err |= TEST_ONE_SHIFT(1, 30, s32, 1 << 30, false);
	err |= TEST_ONE_SHIFT(1, 0, unsigned int, 1U << 0, false);
	err |= TEST_ONE_SHIFT(1, 20, unsigned int, 1U << 20, false);
	err |= TEST_ONE_SHIFT(1, 31, unsigned int, 1U << 31, false);
	err |= TEST_ONE_SHIFT(0xFFFFU, 16, unsigned int, 0xFFFFU << 16, false);
	err |= TEST_ONE_SHIFT(1, 0, u32, 1U << 0, false);
	err |= TEST_ONE_SHIFT(1, 20, u32, 1U << 20, false);
	err |= TEST_ONE_SHIFT(1, 31, u32, 1U << 31, false);
	err |= TEST_ONE_SHIFT(0xFFFFU, 16, u32, 0xFFFFU << 16, false);
	err |= TEST_ONE_SHIFT(1, 0, u64, 1ULL << 0, false);
	err |= TEST_ONE_SHIFT(1, 40, u64, 1ULL << 40, false);
	err |= TEST_ONE_SHIFT(1, 63, u64, 1ULL << 63, false);
	err |= TEST_ONE_SHIFT(0xFFFFFFFFULL, 32, u64,
			      0xFFFFFFFFULL << 32, false);

	/* Sane shift: start and end with 0, without a too-wide shift. */
	err |= TEST_ONE_SHIFT(0, 7, u8, 0, false);
	err |= TEST_ONE_SHIFT(0, 15, u16, 0, false);
	err |= TEST_ONE_SHIFT(0, 31, unsigned int, 0, false);
	err |= TEST_ONE_SHIFT(0, 31, u32, 0, false);
	err |= TEST_ONE_SHIFT(0, 63, u64, 0, false);

	/* Sane shift: start and end with 0, without reaching signed bit. */
	err |= TEST_ONE_SHIFT(0, 6, s8, 0, false);
	err |= TEST_ONE_SHIFT(0, 14, s16, 0, false);
	err |= TEST_ONE_SHIFT(0, 30, int, 0, false);
	err |= TEST_ONE_SHIFT(0, 30, s32, 0, false);
	err |= TEST_ONE_SHIFT(0, 62, s64, 0, false);

	/* Overflow: shifted the bit off the end. */
	err |= TEST_ONE_SHIFT(1, 8, u8, 0, true);
	err |= TEST_ONE_SHIFT(1, 16, u16, 0, true);
	err |= TEST_ONE_SHIFT(1, 32, unsigned int, 0, true);
	err |= TEST_ONE_SHIFT(1, 32, u32, 0, true);
	err |= TEST_ONE_SHIFT(1, 64, u64, 0, true);

	/* Overflow: shifted into the signed bit. */
	err |= TEST_ONE_SHIFT(1, 7, s8, 0, true);
	err |= TEST_ONE_SHIFT(1, 15, s16, 0, true);
	err |= TEST_ONE_SHIFT(1, 31, int, 0, true);
	err |= TEST_ONE_SHIFT(1, 31, s32, 0, true);
	err |= TEST_ONE_SHIFT(1, 63, s64, 0, true);

	/* Overflow: high bit falls off unsigned types. */
	/* 10010110 */
	err |= TEST_ONE_SHIFT(150, 1, u8, 0, true);
	/* 1000100010010110 */
	err |= TEST_ONE_SHIFT(34966, 1, u16, 0, true);
	/* 10000100000010001000100010010110 */
	err |= TEST_ONE_SHIFT(2215151766U, 1, u32, 0, true);
	err |= TEST_ONE_SHIFT(2215151766U, 1, unsigned int, 0, true);
	/* 1000001000010000010000000100000010000100000010001000100010010110 */
	err |= TEST_ONE_SHIFT(9372061470395238550ULL, 1, u64, 0, true);

	/* Overflow: bit shifted into signed bit on signed types. */
	/* 01001011 */
	err |= TEST_ONE_SHIFT(75, 1, s8, 0, true);
	/* 0100010001001011 */
	err |= TEST_ONE_SHIFT(17483, 1, s16, 0, true);
	/* 01000010000001000100010001001011 */
	err |= TEST_ONE_SHIFT(1107575883, 1, s32, 0, true);
	err |= TEST_ONE_SHIFT(1107575883, 1, int, 0, true);
	/* 0100000100001000001000000010000001000010000001000100010001001011 */
	err |= TEST_ONE_SHIFT(4686030735197619275LL, 1, s64, 0, true);

	/* Overflow: bit shifted past signed bit on signed types. */
	/* 01001011 */
	err |= TEST_ONE_SHIFT(75, 2, s8, 0, true);
	/* 0100010001001011 */
	err |= TEST_ONE_SHIFT(17483, 2, s16, 0, true);
	/* 01000010000001000100010001001011 */
	err |= TEST_ONE_SHIFT(1107575883, 2, s32, 0, true);
	err |= TEST_ONE_SHIFT(1107575883, 2, int, 0, true);
	/* 0100000100001000001000000010000001000010000001000100010001001011 */
	err |= TEST_ONE_SHIFT(4686030735197619275LL, 2, s64, 0, true);

	/* Overflow: values larger than destination type. */
	err |= TEST_ONE_SHIFT(0x100, 0, u8, 0, true);
	err |= TEST_ONE_SHIFT(0xFF, 0, s8, 0, true);
	err |= TEST_ONE_SHIFT(0x10000U, 0, u16, 0, true);
	err |= TEST_ONE_SHIFT(0xFFFFU, 0, s16, 0, true);
	err |= TEST_ONE_SHIFT(0x100000000ULL, 0, u32, 0, true);
	err |= TEST_ONE_SHIFT(0x100000000ULL, 0, unsigned int, 0, true);
	err |= TEST_ONE_SHIFT(0xFFFFFFFFUL, 0, s32, 0, true);
	err |= TEST_ONE_SHIFT(0xFFFFFFFFUL, 0, int, 0, true);
	err |= TEST_ONE_SHIFT(0xFFFFFFFFFFFFFFFFULL, 0, s64, 0, true);

	/* Nonsense: negative initial value. */
	err |= TEST_ONE_SHIFT(-1, 0, s8, 0, true);
	err |= TEST_ONE_SHIFT(-1, 0, u8, 0, true);
	err |= TEST_ONE_SHIFT(-5, 0, s16, 0, true);
	err |= TEST_ONE_SHIFT(-5, 0, u16, 0, true);
	err |= TEST_ONE_SHIFT(-10, 0, int, 0, true);
	err |= TEST_ONE_SHIFT(-10, 0, unsigned int, 0, true);
	err |= TEST_ONE_SHIFT(-100, 0, s32, 0, true);
	err |= TEST_ONE_SHIFT(-100, 0, u32, 0, true);
	err |= TEST_ONE_SHIFT(-10000, 0, s64, 0, true);
	err |= TEST_ONE_SHIFT(-10000, 0, u64, 0, true);

	/* Nonsense: negative shift values. */
	err |= TEST_ONE_SHIFT(0, -5, s8, 0, true);
	err |= TEST_ONE_SHIFT(0, -5, u8, 0, true);
	err |= TEST_ONE_SHIFT(0, -10, s16, 0, true);
	err |= TEST_ONE_SHIFT(0, -10, u16, 0, true);
	err |= TEST_ONE_SHIFT(0, -15, int, 0, true);
	err |= TEST_ONE_SHIFT(0, -15, unsigned int, 0, true);
	err |= TEST_ONE_SHIFT(0, -20, s32, 0, true);
	err |= TEST_ONE_SHIFT(0, -20, u32, 0, true);
	err |= TEST_ONE_SHIFT(0, -30, s64, 0, true);
	err |= TEST_ONE_SHIFT(0, -30, u64, 0, true);

	/* Overflow: shifted at or beyond entire type's bit width. */
	err |= TEST_ONE_SHIFT(0, 8, u8, 0, true);
	err |= TEST_ONE_SHIFT(0, 9, u8, 0, true);
	err |= TEST_ONE_SHIFT(0, 8, s8, 0, true);
	err |= TEST_ONE_SHIFT(0, 9, s8, 0, true);
	err |= TEST_ONE_SHIFT(0, 16, u16, 0, true);
	err |= TEST_ONE_SHIFT(0, 17, u16, 0, true);
	err |= TEST_ONE_SHIFT(0, 16, s16, 0, true);
	err |= TEST_ONE_SHIFT(0, 17, s16, 0, true);
	err |= TEST_ONE_SHIFT(0, 32, u32, 0, true);
	err |= TEST_ONE_SHIFT(0, 33, u32, 0, true);
	err |= TEST_ONE_SHIFT(0, 32, int, 0, true);
	err |= TEST_ONE_SHIFT(0, 33, int, 0, true);
	err |= TEST_ONE_SHIFT(0, 32, s32, 0, true);
	err |= TEST_ONE_SHIFT(0, 33, s32, 0, true);
	err |= TEST_ONE_SHIFT(0, 64, u64, 0, true);
	err |= TEST_ONE_SHIFT(0, 65, u64, 0, true);
	err |= TEST_ONE_SHIFT(0, 64, s64, 0, true);
	err |= TEST_ONE_SHIFT(0, 65, s64, 0, true);

	/*
	 * Corner case: for unsigned types, we fail when we've shifted
	 * through the entire width of bits. For signed types, we might
	 * want to match this behavior, but that would mean noticing if
	 * we shift through all but the signed bit, and this is not
	 * currently detected (but we'll notice an overflow into the
	 * signed bit). So, for now, we will test this condition but
	 * mark it as not expected to overflow.
	 */
	err |= TEST_ONE_SHIFT(0, 7, s8, 0, false);
	err |= TEST_ONE_SHIFT(0, 15, s16, 0, false);
	err |= TEST_ONE_SHIFT(0, 31, int, 0, false);
	err |= TEST_ONE_SHIFT(0, 31, s32, 0, false);
	err |= TEST_ONE_SHIFT(0, 63, s64, 0, false);

	return err;
}

/*
 * Deal with the various forms of allocator arguments. See comments above
 * the DEFINE_TEST_ALLOC() instances for mapping of the "bits".
 */
#define alloc_GFP		 (GFP_KERNEL | __GFP_NOWARN)
#define alloc010(alloc, arg, sz) alloc(sz, alloc_GFP)
#define alloc011(alloc, arg, sz) alloc(sz, alloc_GFP, NUMA_NO_NODE)
#define alloc000(alloc, arg, sz) alloc(sz)
#define alloc001(alloc, arg, sz) alloc(sz, NUMA_NO_NODE)
#define alloc110(alloc, arg, sz) alloc(arg, sz, alloc_GFP)
#define free0(free, arg, ptr)	 free(ptr)
#define free1(free, arg, ptr)	 free(arg, ptr)

/* Wrap around to 16K */
#define TEST_SIZE		(5 * 4096)

#define DEFINE_TEST_ALLOC(func, free_func, want_arg, want_gfp, want_node)\
static int __init test_ ## func (void *arg)				\
{									\
	volatile size_t a = TEST_SIZE;					\
	volatile size_t b = (SIZE_MAX / TEST_SIZE) + 1;			\
	void *ptr;							\
									\
	/* Tiny allocation test. */					\
	ptr = alloc ## want_arg ## want_gfp ## want_node (func, arg, 1);\
	if (!ptr) {							\
		pr_warn(#func " failed regular allocation?!\n");	\
		return 1;						\
	}								\
	free ## want_arg (free_func, arg, ptr);				\
									\
	/* Wrapped allocation test. */					\
	ptr = alloc ## want_arg ## want_gfp ## want_node (func, arg,	\
							  a * b);	\
	if (!ptr) {							\
		pr_warn(#func " unexpectedly failed bad wrapping?!\n");	\
		return 1;						\
	}								\
	free ## want_arg (free_func, arg, ptr);				\
									\
	/* Saturated allocation test. */				\
	ptr = alloc ## want_arg ## want_gfp ## want_node (func, arg,	\
						   array_size(a, b));	\
	if (ptr) {							\
		pr_warn(#func " missed saturation!\n");			\
		free ## want_arg (free_func, arg, ptr);			\
		return 1;						\
	}								\
	pr_info(#func " detected saturation\n");			\
	return 0;							\
}

/*
 * Allocator uses a trailing node argument --------+  (e.g. kmalloc_node())
 * Allocator uses the gfp_t argument -----------+  |  (e.g. kmalloc())
 * Allocator uses a special leading argument +  |  |  (e.g. devm_kmalloc())
 *                                           |  |  |
 */
DEFINE_TEST_ALLOC(kmalloc,	 kfree,	     0, 1, 0);
DEFINE_TEST_ALLOC(kmalloc_node,	 kfree,	     0, 1, 1);
DEFINE_TEST_ALLOC(kzalloc,	 kfree,	     0, 1, 0);
DEFINE_TEST_ALLOC(kzalloc_node,  kfree,	     0, 1, 1);
DEFINE_TEST_ALLOC(vmalloc,	 vfree,	     0, 0, 0);
DEFINE_TEST_ALLOC(vmalloc_node,  vfree,	     0, 0, 1);
DEFINE_TEST_ALLOC(vzalloc,	 vfree,	     0, 0, 0);
DEFINE_TEST_ALLOC(vzalloc_node,  vfree,	     0, 0, 1);
DEFINE_TEST_ALLOC(kvmalloc,	 kvfree,     0, 1, 0);
DEFINE_TEST_ALLOC(kvmalloc_node, kvfree,     0, 1, 1);
DEFINE_TEST_ALLOC(kvzalloc,	 kvfree,     0, 1, 0);
DEFINE_TEST_ALLOC(kvzalloc_node, kvfree,     0, 1, 1);
DEFINE_TEST_ALLOC(devm_kmalloc,  devm_kfree, 1, 1, 0);
DEFINE_TEST_ALLOC(devm_kzalloc,  devm_kfree, 1, 1, 0);

static int __init test_overflow_allocation(void)
{
	const char device_name[] = "overflow-test";
	struct device *dev;
	int err = 0;

	/* Create dummy device for devm_kmalloc()-family tests. */
	dev = root_device_register(device_name);
	if (IS_ERR(dev)) {
		pr_warn("Cannot register test device\n");
		return 1;
	}

	err |= test_kmalloc(NULL);
	err |= test_kmalloc_node(NULL);
	err |= test_kzalloc(NULL);
	err |= test_kzalloc_node(NULL);
	err |= test_kvmalloc(NULL);
	err |= test_kvmalloc_node(NULL);
	err |= test_kvzalloc(NULL);
	err |= test_kvzalloc_node(NULL);
	err |= test_vmalloc(NULL);
	err |= test_vmalloc_node(NULL);
	err |= test_vzalloc(NULL);
	err |= test_vzalloc_node(NULL);
	err |= test_devm_kmalloc(dev);
	err |= test_devm_kzalloc(dev);

	device_unregister(dev);

	return err;
}

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

	err |= test_overflow_calculation();
	err |= test_overflow_shift();
	err |= test_overflow_allocation();

	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");
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