Add basic test coverage for files that don't require any config options: * gcd.c * lcm.c * int_sqrt.c * reciprocal_div.c (Ignored int_pow.c since it's a simple textbook algorithm.)

These tests aren't particularly interesting, but they * provide short and simple examples of parameterized tests * provide a place to add tests for any new files in this dir * are written so adding new test cases to cover edge cases should be easy

Signed-off-by: Daniel Latypov dlatypov@google.com --- Changes since v2: mv math_test.c => math_kunit.c

Changes since v1: * Rebase and rewrite to use the new parameterized testing support. * misc: fix overflow in literal and inline int_sqrt format string. * related: commit 1f0e943df68a ("Documentation: kunit: provide guidance for testing many inputs") was merged explaining the patterns shown here. * there's an in-flight patch to update it for parameterized testing.

v1: https://lore.kernel.org/lkml/20201019224556.3536790-1-dlatypov@google.com/ --- lib/math/Kconfig | 5 ++ lib/math/Makefile | 2 + lib/math/math_kunit.c | 197 ++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 204 insertions(+) create mode 100644 lib/math/math_kunit.c

diff --git a/lib/math/Kconfig b/lib/math/Kconfig index f19bc9734fa7..6ba8680439c1 100644 --- a/lib/math/Kconfig +++ b/lib/math/Kconfig @@ -15,3 +15,8 @@ config PRIME_NUMBERS

config RATIONAL bool + +config MATH_KUNIT_TEST + tristate "KUnit test for lib/math" if !KUNIT_ALL_TESTS + default KUNIT_ALL_TESTS + depends on KUNIT diff --git a/lib/math/Makefile b/lib/math/Makefile index be6909e943bd..30abb7a8d564 100644 --- a/lib/math/Makefile +++ b/lib/math/Makefile @@ -4,3 +4,5 @@ obj-y += div64.o gcd.o lcm.o int_pow.o int_sqrt.o reciprocal_div.o obj-$(CONFIG_CORDIC) += cordic.o obj-$(CONFIG_PRIME_NUMBERS) += prime_numbers.o obj-$(CONFIG_RATIONAL) += rational.o + +obj-$(CONFIG_MATH_KUNIT_TEST) += math_kunit.o diff --git a/lib/math/math_kunit.c b/lib/math/math_kunit.c new file mode 100644 index 000000000000..cb2637a24942 --- /dev/null +++ b/lib/math/math_kunit.c @@ -0,0 +1,197 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Simple KUnit suite for math helper funcs that are always enabled. + * + * Copyright (C) 2020, Google LLC. + * Author: Daniel Latypov dlatypov@google.com + */ + +#include <kunit/test.h> +#include <linux/gcd.h> +#include <linux/kernel.h> +#include <linux/lcm.h> +#include <linux/reciprocal_div.h> + +/* Generic test case for unsigned long inputs. */ +struct test_case { + unsigned long a, b; + unsigned long result; +}; + +static struct test_case gcd_cases[] = { + { + .a = 0, .b = 1, + .result = 1, + }, + { + .a = 2, .b = 2, + .result = 2, + }, + { + .a = 2, .b = 4, + .result = 2, + }, + { + .a = 3, .b = 5, + .result = 1, + }, + { + .a = 3*9, .b = 3*5, + .result = 3, + }, + { + .a = 3*5*7, .b = 3*5*11, + .result = 15, + }, + { + .a = 1 << 21, + .b = (1 << 21) - 1, + .result = 1, + }, +}; +KUNIT_ARRAY_PARAM(gcd, gcd_cases, NULL); + +static void gcd_test(struct kunit *test) +{ + const char *message_fmt = "gcd(%lu, %lu)"; + const struct test_case *test_param = test->param_value; + + KUNIT_EXPECT_EQ_MSG(test, test_param->result, + gcd(test_param->a, test_param->b), + message_fmt, test_param->a, + test_param->b); + + /* gcd(a,b) == gcd(b,a) */ + KUNIT_EXPECT_EQ_MSG(test, test_param->result, + gcd(test_param->b, test_param->a), + message_fmt, test_param->b, + test_param->a); +} + + +static struct test_case lcm_cases[] = { + { + .a = 0, .b = 1, + .result = 0, + }, + { + .a = 1, .b = 2, + .result = 2, + }, + { + .a = 2, .b = 2, + .result = 2, + }, + { + .a = 3*5, .b = 3*7, + .result = 3*5*7, + }, +}; +KUNIT_ARRAY_PARAM(lcm, lcm_cases, NULL); + +static void lcm_test(struct kunit *test) +{ + const char *message_fmt = "lcm(%lu, %lu)"; + const struct test_case *test_param = test->param_value; + + KUNIT_EXPECT_EQ_MSG(test, test_param->result, + lcm(test_param->a, test_param->b), + message_fmt, test_param->a, + test_param->b); + + /* lcm(a,b) == lcm(b,a) */ + KUNIT_EXPECT_EQ_MSG(test, test_param->result, + lcm(test_param->b, test_param->a), + message_fmt, test_param->b, + test_param->a); +} + +static struct test_case int_sqrt_cases[] = { + { + .a = 0, + .result = 0, + }, + { + .a = 1, + .result = 1, + }, + { + .a = 4, + .result = 2, + }, + { + .a = 5, + .result = 2, + }, + { + .a = 8, + .result = 2, + }, + { + .a = 1UL << 30, + .result = 1UL << 15, + }, +}; +KUNIT_ARRAY_PARAM(int_sqrt, int_sqrt_cases, NULL); + +static void int_sqrt_test(struct kunit *test) +{ + const struct test_case *test_param = test->param_value; + + KUNIT_EXPECT_EQ_MSG(test, int_sqrt(test_param->a), + test_param->result, "sqrt(%lu)", + test_param->a); +} + +struct reciprocal_test_case { + u32 a, b; + u32 result; +}; + +static struct reciprocal_test_case reciprocal_div_cases[] = { + { + .a = 0, .b = 1, + .result = 0, + }, + { + .a = 42, .b = 20, + .result = 2, + }, + { + .a = 42, .b = 9999, + .result = 0, + }, + { + .a = (1<<16), .b = (1<<14), + .result = 1<<2, + }, +}; +KUNIT_ARRAY_PARAM(reciprocal_div, reciprocal_div_cases, NULL); + +static void reciprocal_div_test(struct kunit *test) +{ + const struct reciprocal_test_case *test_param = test->param_value; + struct reciprocal_value rv = reciprocal_value(test_param->b); + + KUNIT_EXPECT_EQ_MSG(test, test_param->result, + reciprocal_divide(test_param->a, rv), + "reciprocal_divide(%u, %u)", + test_param->a, test_param->b); +} + +static struct kunit_case math_test_cases[] = { + KUNIT_CASE_PARAM(gcd_test, gcd_gen_params), + KUNIT_CASE_PARAM(lcm_test, lcm_gen_params), + KUNIT_CASE_PARAM(int_sqrt_test, int_sqrt_gen_params), + KUNIT_CASE_PARAM(reciprocal_div_test, reciprocal_div_gen_params), + {} +}; + +static struct kunit_suite math_test_suite = { + .name = "lib-math", + .test_cases = math_test_cases, +}; + +kunit_test_suites(&math_test_suite); + +MODULE_LICENSE("GPL v2");

base-commit: 65f0d2414b7079556fbbcc070b3d1c9f9587606d