@@ -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
@@ -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_test.o
new file mode 100644
@@ -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");
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 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 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_test.c | 197 +++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 204 insertions(+) create mode 100644 lib/math/math_test.c base-commit: 65f0d2414b7079556fbbcc070b3d1c9f9587606d