Re: [PATCH] lib: kunit_test_overflow: add KUnit test of check_*_overflow functions

From: Brendan Higgins
Date: Fri Jun 12 2020 - 15:06:53 EST


On Thu, Jun 11, 2020 at 2:55 PM Vitor Massaru Iha <vitor@xxxxxxxxxxx> wrote:
>
> This adds the convertion of the runtime tests of check_*_overflow fuctions,
> from `lib/test_overflow.c`to KUnit tests.
>
> The log similar to the one seen in dmesg running test_overflow can be
> seen in `test.log`.
>
> Signed-off-by: Vitor Massaru Iha <vitor@xxxxxxxxxxx>
> ---
> lib/Kconfig.debug | 17 ++
> lib/Makefile | 1 +
> lib/kunit_overflow_test.c | 590 ++++++++++++++++++++++++++++++++++++++
> 3 files changed, 608 insertions(+)
> create mode 100644 lib/kunit_overflow_test.c
>
> diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
> index 1f4ab7a2bdee..72fcfe1f24a4 100644
> --- a/lib/Kconfig.debug
> +++ b/lib/Kconfig.debug
> @@ -2075,6 +2075,23 @@ config SYSCTL_KUNIT_TEST
>
> If unsure, say N.
>
> +config OVERFLOW_KUNIT_TEST
> + tristate "KUnit test for overflow" if !KUNIT_ALL_TESTS
> + depends on KUNIT
> + default KUNIT_ALL_TESTS
> + help
> + This builds the overflow KUnit tests.
> +
> + KUnit tests run during boot and output the results to the debug log
> + in TAP format (http://testanything.org/). Only useful for kernel devs
> + running KUnit test harness and are not for inclusion into a production
> + build.
> +
> + For more information on KUnit and unit tests in general please refer
> + to the KUnit documentation in Documentation/dev-tools/kunit/.
> +
> + If unsure, say N.

Since this is a migration of the overflow runtime test, I feel like
you should delete it here. I also think it would probably make this
easier to read for Kees and the other maintainers since it highlights
what you are changing in the test.

> config LIST_KUNIT_TEST
> tristate "KUnit Test for Kernel Linked-list structures" if !KUNIT_ALL_TESTS
> depends on KUNIT
> diff --git a/lib/Makefile b/lib/Makefile
> index 685aee60de1d..a3290adc0019 100644
> --- a/lib/Makefile
> +++ b/lib/Makefile
> @@ -309,3 +309,4 @@ obj-$(CONFIG_OBJAGG) += objagg.o
>
> # KUnit tests
> obj-$(CONFIG_LIST_KUNIT_TEST) += list-test.o
> +obj-$(CONFIG_OVERFLOW_KUNIT_TEST) += kunit_overflow_test.o
> diff --git a/lib/kunit_overflow_test.c b/lib/kunit_overflow_test.c
> new file mode 100644
> index 000000000000..c3eb8f0d3d50
> --- /dev/null
> +++ b/lib/kunit_overflow_test.c
> @@ -0,0 +1,590 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * This code is the conversion of the overflow test in runtime to KUnit tests.
> + */
> +
> +/*
> + * Test cases for arithmetic overflow checks.
> + */
> +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
> +
> +#include <kunit/test.h>
> +#include <linux/device.h>
> +#include <linux/init.h>
> +#include <linux/mm.h>
> +#include <linux/overflow.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[]
> +
> +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(test, t, fmt, op, sym, a, b, r, of) do { \
> + t _r; \
> + bool _of; \
> + \
> + _of = check_ ## op ## _overflow(a, b, &_r); \
> + if (_of != of) { \
> + KUNIT_FAIL(test, "Expected "fmt" "sym" "fmt \
> + " to%s overflow (type %s)\n", \
> + a, b, of ? "" : " not", #t); \
> + } \
> + if (_r != r) { \
> + KUNIT_FAIL(test, "Expected "fmt" "sym" "fmt" == " \
> + fmt", got "fmt" (type %s)\n", \
> + a, b, r, _r, #t); \
> + } \
> +} while (0)
> +
> +#define DEFINE_TEST_FUNC(test, t, fmt) \
> +static void do_test_ ## t(struct kunit *test, const struct test_ ## t *p) \
> +{ \
> + check_one_op(test, t, fmt, add, "+", p->a, p->b, p->sum, p->s_of); \
> + check_one_op(test, t, fmt, add, "+", p->b, p->a, p->sum, p->s_of); \
> + check_one_op(test, t, fmt, sub, "-", p->a, p->b, p->diff, p->d_of); \
> + check_one_op(test, t, fmt, mul, "*", p->a, p->b, p->prod, p->p_of); \
> + check_one_op(test, t, fmt, mul, "*", p->b, p->a, p->prod, p->p_of); \
> +} \
> + \
> +static void test_ ## t ## _overflow(struct kunit *test) \
> +{ \
> + unsigned i; \
> + \
> + kunit_warn(test, "%-3s: %zu arithmetic tests\n", #t, \
> + ARRAY_SIZE(t ## _tests)); \
> + for (i = 0; i < ARRAY_SIZE(t ## _tests); ++i) \
> + do_test_ ## t(test, &t ## _tests[i]); \
> +}
> +
> +DEFINE_TEST_FUNC(test, u8, "%d");
> +DEFINE_TEST_FUNC(test, s8, "%d");
> +DEFINE_TEST_FUNC(test, u16, "%d");
> +DEFINE_TEST_FUNC(test, s16, "%d");
> +DEFINE_TEST_FUNC(test, u32, "%u");
> +DEFINE_TEST_FUNC(test, s32, "%d");
> +#if BITS_PER_LONG == 64
> +DEFINE_TEST_FUNC(test, u64, "%llu");
> +DEFINE_TEST_FUNC(test, s64, "%lld");
> +#endif
> +
> +static void overflow_calculation_test(struct kunit *test)
> +{
> +
> + test_u8_overflow(test);
> + test_s8_overflow(test);
> + test_s8_overflow(test);
> + test_u16_overflow(test);
> + test_s16_overflow(test);
> + test_u32_overflow(test);
> + test_s32_overflow(test);
> +#if BITS_PER_LONG == 64
> + test_u64_overflow(test);
> + test_s64_overflow(test);
> +#endif
> +}
> +
> +static void overflow_shift_test(struct kunit *test)
> +{
> +/* 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) { \
> + KUNIT_FAIL(test, "Expected (%s)(%s << %s) to%s overflow\n", \

I mentioned this offline: I am of two minds on this. Part of me would
like to make it more KUnit-y, but part of me thinks that it is best to
not change the test more than necessary. I am fine either way, I just
wanted to draw attention to it for other reviewers who may care.

> + #t, #a, #s, of ? "" : " not"); \
> + __failed = 1; \
> + } else if (!__of && __d != __e) { \
> + KUNIT_FAIL(test, "Expected (%s)(%s << %s) == %s\n", \
> + #t, #a, #s, #expect); \
> + if ((t)-1 < 0) \
> + KUNIT_FAIL(test, "got %lld\n", (s64)__d); \
> + else \
> + KUNIT_FAIL(test, "got %llu\n", (u64)__d); \
> + __failed = 1; \
> + } \
> + if (!__failed) \
> + kunit_info(test, "ok: (%s)(%s << %s) == %s\n", #t, #a, #s, \
> + of ? "overflow" : #expect); \
> + __failed; \
> +})
> +
> + /* Sane shifts. */
> + TEST_ONE_SHIFT(1, 0, u8, 1 << 0, false);
> + TEST_ONE_SHIFT(1, 4, u8, 1 << 4, false);
> + TEST_ONE_SHIFT(1, 7, u8, 1 << 7, false);
> + TEST_ONE_SHIFT(0xF, 4, u8, 0xF << 4, false);
> + TEST_ONE_SHIFT(1, 0, u16, 1 << 0, false);
> + TEST_ONE_SHIFT(1, 10, u16, 1 << 10, false);
> + TEST_ONE_SHIFT(1, 15, u16, 1 << 15, false);
> + TEST_ONE_SHIFT(0xFF, 8, u16, 0xFF << 8, false);
> + TEST_ONE_SHIFT(1, 0, int, 1 << 0, false);
> + TEST_ONE_SHIFT(1, 16, int, 1 << 16, false);
> + TEST_ONE_SHIFT(1, 30, int, 1 << 30, false);
> + TEST_ONE_SHIFT(1, 0, s32, 1 << 0, false);
> + TEST_ONE_SHIFT(1, 16, s32, 1 << 16, false);
> + TEST_ONE_SHIFT(1, 30, s32, 1 << 30, false);
> + TEST_ONE_SHIFT(1, 0, unsigned int, 1U << 0, false);
> + TEST_ONE_SHIFT(1, 20, unsigned int, 1U << 20, false);
> + TEST_ONE_SHIFT(1, 31, unsigned int, 1U << 31, false);
> + TEST_ONE_SHIFT(0xFFFFU, 16, unsigned int, 0xFFFFU << 16, false);
> + TEST_ONE_SHIFT(1, 0, u32, 1U << 0, false);
> + TEST_ONE_SHIFT(1, 20, u32, 1U << 20, false);
> + TEST_ONE_SHIFT(1, 31, u32, 1U << 31, false);
> + TEST_ONE_SHIFT(0xFFFFU, 16, u32, 0xFFFFU << 16, false);
> + TEST_ONE_SHIFT(1, 0, u64, 1ULL << 0, false);
> + TEST_ONE_SHIFT(1, 40, u64, 1ULL << 40, false);
> + TEST_ONE_SHIFT(1, 63, u64, 1ULL << 63, false);
> + TEST_ONE_SHIFT(0xFFFFFFFFULL, 32, u64,
> + 0xFFFFFFFFULL << 32, false);
> +
> + /* Sane shift: start and end with 0, without a too-wide shift. */
> + TEST_ONE_SHIFT(0, 7, u8, 0, false);
> + TEST_ONE_SHIFT(0, 15, u16, 0, false);
> + TEST_ONE_SHIFT(0, 31, unsigned int, 0, false);
> + TEST_ONE_SHIFT(0, 31, u32, 0, false);
> + TEST_ONE_SHIFT(0, 63, u64, 0, false);
> +
> + /* Sane shift: start and end with 0, without reaching signed bit. */
> + TEST_ONE_SHIFT(0, 6, s8, 0, false);
> + TEST_ONE_SHIFT(0, 14, s16, 0, false);
> + TEST_ONE_SHIFT(0, 30, int, 0, false);
> + TEST_ONE_SHIFT(0, 30, s32, 0, false);
> + TEST_ONE_SHIFT(0, 62, s64, 0, false);
> +
> + /* Overflow: shifted the bit off the end. */
> + TEST_ONE_SHIFT(1, 8, u8, 0, true);
> + TEST_ONE_SHIFT(1, 16, u16, 0, true);
> + TEST_ONE_SHIFT(1, 32, unsigned int, 0, true);
> + TEST_ONE_SHIFT(1, 32, u32, 0, true);
> + TEST_ONE_SHIFT(1, 64, u64, 0, true);
> +
> + /* Overflow: shifted into the signed bit. */
> + TEST_ONE_SHIFT(1, 7, s8, 0, true);
> + TEST_ONE_SHIFT(1, 15, s16, 0, true);
> + TEST_ONE_SHIFT(1, 31, int, 0, true);
> + TEST_ONE_SHIFT(1, 31, s32, 0, true);
> + TEST_ONE_SHIFT(1, 63, s64, 0, true);
> +
> + /* Overflow: high bit falls off unsigned types. */
> + /* 10010110 */
> + TEST_ONE_SHIFT(150, 1, u8, 0, true);
> + /* 1000100010010110 */
> + TEST_ONE_SHIFT(34966, 1, u16, 0, true);
> + /* 10000100000010001000100010010110 */
> + TEST_ONE_SHIFT(2215151766U, 1, u32, 0, true);
> + TEST_ONE_SHIFT(2215151766U, 1, unsigned int, 0, true);
> + /* 1000001000010000010000000100000010000100000010001000100010010110 */
> + TEST_ONE_SHIFT(9372061470395238550ULL, 1, u64, 0, true);
> +
> + /* Overflow: bit shifted into signed bit on signed types. */
> + /* 01001011 */
> + TEST_ONE_SHIFT(75, 1, s8, 0, true);
> + /* 0100010001001011 */
> + TEST_ONE_SHIFT(17483, 1, s16, 0, true);
> + /* 01000010000001000100010001001011 */
> + TEST_ONE_SHIFT(1107575883, 1, s32, 0, true);
> + TEST_ONE_SHIFT(1107575883, 1, int, 0, true);
> + /* 0100000100001000001000000010000001000010000001000100010001001011 */
> + TEST_ONE_SHIFT(4686030735197619275LL, 1, s64, 0, true);
> +
> + /* Overflow: bit shifted past signed bit on signed types. */
> + /* 01001011 */
> + TEST_ONE_SHIFT(75, 2, s8, 0, true);
> + /* 0100010001001011 */
> + TEST_ONE_SHIFT(17483, 2, s16, 0, true);
> + /* 01000010000001000100010001001011 */
> + TEST_ONE_SHIFT(1107575883, 2, s32, 0, true);
> + TEST_ONE_SHIFT(1107575883, 2, int, 0, true);
> + /* 0100000100001000001000000010000001000010000001000100010001001011 */
> + TEST_ONE_SHIFT(4686030735197619275LL, 2, s64, 0, true);
> +
> + /* Overflow: values larger than destination type. */
> + TEST_ONE_SHIFT(0x100, 0, u8, 0, true);
> + TEST_ONE_SHIFT(0xFF, 0, s8, 0, true);
> + TEST_ONE_SHIFT(0x10000U, 0, u16, 0, true);
> + TEST_ONE_SHIFT(0xFFFFU, 0, s16, 0, true);
> + TEST_ONE_SHIFT(0x100000000ULL, 0, u32, 0, true);
> + TEST_ONE_SHIFT(0x100000000ULL, 0, unsigned int, 0, true);
> + TEST_ONE_SHIFT(0xFFFFFFFFUL, 0, s32, 0, true);
> + TEST_ONE_SHIFT(0xFFFFFFFFUL, 0, int, 0, true);
> + TEST_ONE_SHIFT(0xFFFFFFFFFFFFFFFFULL, 0, s64, 0, true);
> +
> + /* Nonsense: negative initial value. */
> + TEST_ONE_SHIFT(-1, 0, s8, 0, true);
> + TEST_ONE_SHIFT(-1, 0, u8, 0, true);
> + TEST_ONE_SHIFT(-5, 0, s16, 0, true);
> + TEST_ONE_SHIFT(-5, 0, u16, 0, true);
> + TEST_ONE_SHIFT(-10, 0, int, 0, true);
> + TEST_ONE_SHIFT(-10, 0, unsigned int, 0, true);
> + TEST_ONE_SHIFT(-100, 0, s32, 0, true);
> + TEST_ONE_SHIFT(-100, 0, u32, 0, true);
> + TEST_ONE_SHIFT(-10000, 0, s64, 0, true);
> + TEST_ONE_SHIFT(-10000, 0, u64, 0, true);
> +
> + /* Nonsense: negative shift values. */
> + TEST_ONE_SHIFT(0, -5, s8, 0, true);
> + TEST_ONE_SHIFT(0, -5, u8, 0, true);
> + TEST_ONE_SHIFT(0, -10, s16, 0, true);
> + TEST_ONE_SHIFT(0, -10, u16, 0, true);
> + TEST_ONE_SHIFT(0, -15, int, 0, true);
> + TEST_ONE_SHIFT(0, -15, unsigned int, 0, true);
> + TEST_ONE_SHIFT(0, -20, s32, 0, true);
> + TEST_ONE_SHIFT(0, -20, u32, 0, true);
> + TEST_ONE_SHIFT(0, -30, s64, 0, true);
> + TEST_ONE_SHIFT(0, -30, u64, 0, true);
> +
> + /* Overflow: shifted at or beyond entire type's bit width. */
> + TEST_ONE_SHIFT(0, 8, u8, 0, true);
> + TEST_ONE_SHIFT(0, 9, u8, 0, true);
> + TEST_ONE_SHIFT(0, 8, s8, 0, true);
> + TEST_ONE_SHIFT(0, 9, s8, 0, true);
> + TEST_ONE_SHIFT(0, 16, u16, 0, true);
> + TEST_ONE_SHIFT(0, 17, u16, 0, true);
> + TEST_ONE_SHIFT(0, 16, s16, 0, true);
> + TEST_ONE_SHIFT(0, 17, s16, 0, true);
> + TEST_ONE_SHIFT(0, 32, u32, 0, true);
> + TEST_ONE_SHIFT(0, 33, u32, 0, true);
> + TEST_ONE_SHIFT(0, 32, int, 0, true);
> + TEST_ONE_SHIFT(0, 33, int, 0, true);
> + TEST_ONE_SHIFT(0, 32, s32, 0, true);
> + TEST_ONE_SHIFT(0, 33, s32, 0, true);
> + TEST_ONE_SHIFT(0, 64, u64, 0, true);
> + TEST_ONE_SHIFT(0, 65, u64, 0, true);
> + TEST_ONE_SHIFT(0, 64, s64, 0, true);
> + 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.
> + */
> + TEST_ONE_SHIFT(0, 7, s8, 0, false);
> + TEST_ONE_SHIFT(0, 15, s16, 0, false);
> + TEST_ONE_SHIFT(0, 31, int, 0, false);
> + TEST_ONE_SHIFT(0, 31, s32, 0, false);
> + TEST_ONE_SHIFT(0, 63, s64, 0, false);
> +}
> +
> +/*
> + * 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(test, func, free_func, want_arg, want_gfp, want_node) \
> +static void test_ ## func (struct kunit *test, 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); \
> + KUNIT_EXPECT_NOT_ERR_OR_NULL(test, ptr); \
> + if (!ptr) { \
> + kunit_err(test, #func " failed regular allocation?!\n"); \
> + } \
> + free ## want_arg (free_func, arg, ptr); \
> + \
> + /* Wrapped allocation test. */ \
> + ptr = alloc ## want_arg ## want_gfp ## want_node (func, arg, a * b); \
> + KUNIT_EXPECT_NOT_ERR_OR_NULL(test, ptr); \
> + if (!ptr) { \
> + kunit_err(test, #func " unexpectedly failed bad wrapping?!\n"); \
> + } \
> + free ## want_arg (free_func, arg, ptr); \
> + \
> + /* Saturated allocation test. */ \
> + ptr = alloc ## want_arg ## want_gfp ## want_node (func, arg, \
> + array_size(a, b)); \
> + KUNIT_ASSERT_TRUE(test, IS_ERR_OR_NULL(ptr)); \
> + if (ptr) { \
> + kunit_err(test, #func " missed saturation!\n"); \
> + free ## want_arg (free_func, arg, ptr); \
> + } \
> + kunit_info(test, #func " detected saturation\n"); \
> +}
> +
> +/*
> + * 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(test, kmalloc, kfree, 0, 1, 0);
> +DEFINE_TEST_ALLOC(test, kmalloc_node, kfree, 0, 1, 1);
> +DEFINE_TEST_ALLOC(test, kzalloc, kfree, 0, 1, 0);
> +DEFINE_TEST_ALLOC(test, kzalloc_node, kfree, 0, 1, 1);
> +DEFINE_TEST_ALLOC(test, vmalloc, vfree, 0, 0, 0);
> +DEFINE_TEST_ALLOC(test, vmalloc_node, vfree, 0, 0, 1);
> +DEFINE_TEST_ALLOC(test, vzalloc, vfree, 0, 0, 0);
> +DEFINE_TEST_ALLOC(test, vzalloc_node, vfree, 0, 0, 1);
> +DEFINE_TEST_ALLOC(test, kvmalloc, kvfree, 0, 1, 0);
> +DEFINE_TEST_ALLOC(test, kvmalloc_node, kvfree, 0, 1, 1);
> +DEFINE_TEST_ALLOC(test, kvzalloc, kvfree, 0, 1, 0);
> +DEFINE_TEST_ALLOC(test, kvzalloc_node, kvfree, 0, 1, 1);
> +DEFINE_TEST_ALLOC(test, devm_kmalloc, devm_kfree, 1, 1, 0);
> +DEFINE_TEST_ALLOC(test, devm_kzalloc, devm_kfree, 1, 1, 0);
> +
> +static void overflow_allocation_test(struct kunit *test)
> +{
> + const char device_name[] = "overflow-test";
> + struct device *dev;
> +
> + /* Create dummy device for devm_kmalloc()-family tests. */
> + dev = root_device_register(device_name);
> + if (IS_ERR(dev))
> + kunit_warn(test, "Cannot register test device\n");
> +
> + test_kmalloc(test, NULL);
> + test_kmalloc_node(test, NULL);
> + test_kzalloc(test, NULL);
> + test_kzalloc_node(test, NULL);
> + test_kvmalloc(test, NULL);
> + test_kvmalloc_node(test, NULL);
> + test_kvzalloc(test, NULL);
> + test_kvzalloc_node(test, NULL);
> + test_vmalloc(test, NULL);
> + test_vmalloc_node(test, NULL);
> + test_vzalloc(test, NULL);
> + test_vzalloc_node(test, NULL);
> + test_devm_kmalloc(test, dev);
> + test_devm_kzalloc(test, dev);
> +
> + device_unregister(dev);
> +}
> +
> +static struct kunit_case overflow_test_cases[] = {
> + KUNIT_CASE(overflow_calculation_test),
> + KUNIT_CASE(overflow_shift_test),
> + KUNIT_CASE(overflow_allocation_test),
> + {}
> +};
> +
> +static struct kunit_suite overflow_test_suite = {
> + .name = "overflow",
> + .test_cases = overflow_test_cases,
> +};
> +
> +kunit_test_suites(&overflow_test_suite);
> +
> +MODULE_LICENSE("GPL v2");
> --
> 2.26.2
>