treewide: refresh kmalloc_obj() conversionsgrafted

This is another run of the Coccinelle script for converting kmalloc()
family of allocations to kmalloc_obj() via the existing rules in
scripts/coccinelle/api/kmalloc_objs.cocci

This catches both the set of kmalloc() uses added since the first
kmalloc_obj() conversions in v7.0 and adds a large group missed in the
first pass due to Coccinelle not interacting well with the cleanup.h
scoped_...() family of macros[1]. I worked around this with spatch's
"--macro-file" argument to a file with all the scoped_...() macros mapped
to Coccinelle's YACFE_ITERATOR[2] as that was the closest viable control
flow indicator I could find.

Build tested allmodconfig on x86, arm64, arm, loongarch, mips, powerpc,
riscv, and s390 with no new warnings.

Link: https://lore.kernel.org/lkml/202609021314.8A9C0B8@keescook/ [1]
Link: https://github.com/coccinelle/coccinelle/blob/master/standard.h [2]
Signed-off-by: Kees Cook <kees+treewide@kernel.org>

8 files changed, 641 insertions, 0 deletions

diff --git a/lib/math/tests/Makefile b/lib/math/tests/Makefile
new file mode 100644
index 000000000..85e1ad59f
--- /dev/null
+++ b/lib/math/tests/Makefile
@@ -0,0 +1,9 @@
+# SPDX-License-Identifier: GPL-2.0-only
+
+obj-$(CONFIG_GCD_KUNIT_TEST)		+= gcd_kunit.o
+obj-$(CONFIG_INT_LOG_KUNIT_TEST)	+= int_log_kunit.o
+obj-$(CONFIG_INT_POW_KUNIT_TEST)	+= int_pow_kunit.o
+obj-$(CONFIG_INT_SQRT_KUNIT_TEST)	+= int_sqrt_kunit.o
+obj-$(CONFIG_POLYNOMIAL_KUNIT_TEST)	+= polynomial_kunit.o
+obj-$(CONFIG_PRIME_NUMBERS_KUNIT_TEST)	+= prime_numbers_kunit.o
+obj-$(CONFIG_RATIONAL_KUNIT_TEST)	+= rational_kunit.o
diff --git a/lib/math/tests/gcd_kunit.c b/lib/math/tests/gcd_kunit.c
new file mode 100644
index 000000000..ede188358
--- /dev/null
+++ b/lib/math/tests/gcd_kunit.c
@@ -0,0 +1,56 @@
+// SPDX-License-Identifier: GPL-2.0-only
+
+#include <kunit/test.h>
+#include <linux/gcd.h>
+#include <linux/limits.h>
+
+struct test_case_params {
+	unsigned long val1;
+	unsigned long val2;
+	unsigned long expected_result;
+	const char *name;
+};
+
+static const struct test_case_params params[] = {
+	{ 48, 18, 6, "GCD of 48 and 18" },
+	{ 18, 48, 6, "GCD of 18 and 48" },
+	{ 56, 98, 14, "GCD of 56 and 98" },
+	{ 17, 13, 1, "Coprime numbers" },
+	{ 101, 103, 1, "Coprime numbers" },
+	{ 270, 192, 6, "GCD of 270 and 192" },
+	{ 0, 5, 5, "GCD with zero" },
+	{ 7, 0, 7, "GCD with zero reversed" },
+	{ 36, 36, 36, "GCD of identical numbers" },
+	{ ULONG_MAX, 1, 1, "GCD of max ulong and 1" },
+	{ ULONG_MAX, ULONG_MAX, ULONG_MAX, "GCD of max ulong values" },
+};
+
+static void get_desc(const struct test_case_params *tc, char *desc)
+{
+	strscpy(desc, tc->name, KUNIT_PARAM_DESC_SIZE);
+}
+
+KUNIT_ARRAY_PARAM(gcd, params, get_desc);
+
+static void gcd_test(struct kunit *test)
+{
+	const struct test_case_params *tc = (const struct test_case_params *)test->param_value;
+
+	KUNIT_EXPECT_EQ(test, tc->expected_result, gcd(tc->val1, tc->val2));
+}
+
+static struct kunit_case math_gcd_test_cases[] = {
+	KUNIT_CASE_PARAM(gcd_test, gcd_gen_params),
+	{}
+};
+
+static struct kunit_suite gcd_test_suite = {
+	.name = "math-gcd",
+	.test_cases = math_gcd_test_cases,
+};
+
+kunit_test_suite(gcd_test_suite);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("math.gcd KUnit test suite");
+MODULE_AUTHOR("Yu-Chun Lin <eleanor15x@gmail.com>");
diff --git a/lib/math/tests/int_log_kunit.c b/lib/math/tests/int_log_kunit.c
new file mode 100644
index 000000000..14e854146
--- /dev/null
+++ b/lib/math/tests/int_log_kunit.c
@@ -0,0 +1,74 @@
+// SPDX-License-Identifier: GPL-2.0-only
+#include <kunit/test.h>
+#include <linux/int_log.h>
+
+struct test_case_params {
+	u32 value;
+	unsigned int expected_result;
+	const char *name;
+};
+
+
+/* The expected result takes into account the log error */
+static const struct test_case_params intlog2_params[] = {
+	{0, 0, "Log base 2 of 0"},
+	{1, 0, "Log base 2 of 1"},
+	{2, 16777216, "Log base 2 of 2"},
+	{3, 26591232, "Log base 2 of 3"},
+	{4, 33554432, "Log base 2 of 4"},
+	{8, 50331648, "Log base 2 of 8"},
+	{16, 67108864, "Log base 2 of 16"},
+	{32, 83886080, "Log base 2 of 32"},
+	{U32_MAX, 536870911, "Log base 2 of MAX"},
+};
+
+static const struct test_case_params intlog10_params[] = {
+	{0, 0, "Log base 10 of 0"},
+	{1, 0, "Log base 10 of 1"},
+	{6, 13055203, "Log base 10 of 6"},
+	{10, 16777225, "Log base 10 of 10"},
+	{100, 33554450, "Log base 10 of 100"},
+	{1000, 50331675, "Log base 10 of 1000"},
+	{10000, 67108862, "Log base 10 of 10000"},
+	{U32_MAX, 161614247, "Log base 10 of MAX"}
+};
+
+static void get_desc(const struct test_case_params *tc, char *desc)
+{
+	strscpy(desc, tc->name, KUNIT_PARAM_DESC_SIZE);
+}
+
+
+KUNIT_ARRAY_PARAM(intlog2, intlog2_params, get_desc);
+
+static void intlog2_test(struct kunit *test)
+{
+	const struct test_case_params *tc = (const struct test_case_params *)test->param_value;
+
+	KUNIT_EXPECT_EQ(test, tc->expected_result, intlog2(tc->value));
+}
+
+KUNIT_ARRAY_PARAM(intlog10, intlog10_params, get_desc);
+
+static void intlog10_test(struct kunit *test)
+{
+	const struct test_case_params *tc = (const struct test_case_params *)test->param_value;
+
+	KUNIT_EXPECT_EQ(test, tc->expected_result, intlog10(tc->value));
+}
+
+static struct kunit_case math_int_log_test_cases[] = {
+	KUNIT_CASE_PARAM(intlog2_test, intlog2_gen_params),
+	KUNIT_CASE_PARAM(intlog10_test, intlog10_gen_params),
+	{}
+};
+
+static struct kunit_suite int_log_test_suite = {
+	.name = "math-int_log",
+	.test_cases =  math_int_log_test_cases,
+};
+
+kunit_test_suites(&int_log_test_suite);
+
+MODULE_DESCRIPTION("math.int_log KUnit test suite");
+MODULE_LICENSE("GPL");
diff --git a/lib/math/tests/int_pow_kunit.c b/lib/math/tests/int_pow_kunit.c
new file mode 100644
index 000000000..34b33677d
--- /dev/null
+++ b/lib/math/tests/int_pow_kunit.c
@@ -0,0 +1,52 @@
+// SPDX-License-Identifier: GPL-2.0-only
+
+#include <kunit/test.h>
+#include <linux/math.h>
+
+struct test_case_params {
+	u64 base;
+	unsigned int exponent;
+	u64 expected_result;
+	const char *name;
+};
+
+static const struct test_case_params params[] = {
+	{ 64, 0, 1, "Power of zero" },
+	{ 64, 1, 64, "Power of one"},
+	{ 0, 5, 0, "Base zero" },
+	{ 1, 64, 1, "Base one" },
+	{ 2, 2, 4, "Two squared"},
+	{ 2, 3, 8, "Two cubed"},
+	{ 5, 5, 3125, "Five raised to the fifth power" },
+	{ U64_MAX, 1, U64_MAX, "Max base" },
+	{ 2, 63, 9223372036854775808ULL, "Large result"},
+};
+
+static void get_desc(const struct test_case_params *tc, char *desc)
+{
+	strscpy(desc, tc->name, KUNIT_PARAM_DESC_SIZE);
+}
+
+KUNIT_ARRAY_PARAM(int_pow, params, get_desc);
+
+static void int_pow_test(struct kunit *test)
+{
+	const struct test_case_params *tc = (const struct test_case_params *)test->param_value;
+
+	KUNIT_EXPECT_EQ(test, tc->expected_result, int_pow(tc->base, tc->exponent));
+}
+
+static struct kunit_case math_int_pow_test_cases[] = {
+	KUNIT_CASE_PARAM(int_pow_test, int_pow_gen_params),
+	{}
+};
+
+static struct kunit_suite int_pow_test_suite = {
+	.name = "math-int_pow",
+	.test_cases = math_int_pow_test_cases,
+};
+
+kunit_test_suites(&int_pow_test_suite);
+
+MODULE_DESCRIPTION("math.int_pow KUnit test suite");
+MODULE_LICENSE("GPL");
diff --git a/lib/math/tests/int_sqrt_kunit.c b/lib/math/tests/int_sqrt_kunit.c
new file mode 100644
index 000000000..1798e1312
--- /dev/null
+++ b/lib/math/tests/int_sqrt_kunit.c
@@ -0,0 +1,66 @@
+// SPDX-License-Identifier: GPL-2.0-only
+
+#include <kunit/test.h>
+#include <linux/limits.h>
+#include <linux/math.h>
+#include <linux/module.h>
+#include <linux/string.h>
+
+struct test_case_params {
+	unsigned long x;
+	unsigned long expected_result;
+	const char *name;
+};
+
+static const struct test_case_params params[] = {
+	{ 0, 0, "edge case: square root of 0" },
+	{ 1, 1, "perfect square: square root of 1" },
+	{ 2, 1, "non-perfect square: square root of 2" },
+	{ 3, 1, "non-perfect square: square root of 3" },
+	{ 4, 2, "perfect square: square root of 4" },
+	{ 5, 2, "non-perfect square: square root of 5" },
+	{ 6, 2, "non-perfect square: square root of 6" },
+	{ 7, 2, "non-perfect square: square root of 7" },
+	{ 8, 2, "non-perfect square: square root of 8" },
+	{ 9, 3, "perfect square: square root of 9" },
+	{ 15, 3, "non-perfect square: square root of 15 (N-1 from 16)" },
+	{ 16, 4, "perfect square: square root of 16" },
+	{ 17, 4, "non-perfect square: square root of 17 (N+1 from 16)" },
+	{ 80, 8, "non-perfect square: square root of 80 (N-1 from 81)" },
+	{ 81, 9, "perfect square: square root of 81" },
+	{ 82, 9, "non-perfect square: square root of 82 (N+1 from 81)" },
+	{ 255, 15, "non-perfect square: square root of 255 (N-1 from 256)" },
+	{ 256, 16, "perfect square: square root of 256" },
+	{ 257, 16, "non-perfect square: square root of 257 (N+1 from 256)" },
+	{ 2147483648, 46340, "large input: square root of 2147483648" },
+	{ 4294967295, 65535, "edge case: ULONG_MAX for 32-bit" },
+};
+
+static void get_desc(const struct test_case_params *tc, char *desc)
+{
+	strscpy(desc, tc->name, KUNIT_PARAM_DESC_SIZE);
+}
+
+KUNIT_ARRAY_PARAM(int_sqrt, params, get_desc);
+
+static void int_sqrt_test(struct kunit *test)
+{
+	const struct test_case_params *tc = (const struct test_case_params *)test->param_value;
+
+	KUNIT_EXPECT_EQ(test, tc->expected_result, int_sqrt(tc->x));
+}
+
+static struct kunit_case math_int_sqrt_test_cases[] = {
+	KUNIT_CASE_PARAM(int_sqrt_test, int_sqrt_gen_params),
+	{}
+};
+
+static struct kunit_suite int_sqrt_test_suite = {
+	.name = "math-int_sqrt",
+	.test_cases = math_int_sqrt_test_cases,
+};
+
+kunit_test_suites(&int_sqrt_test_suite);
+
+MODULE_DESCRIPTION("math.int_sqrt KUnit test suite");
+MODULE_LICENSE("GPL");
diff --git a/lib/math/tests/polynomial_kunit.c b/lib/math/tests/polynomial_kunit.c
new file mode 100644
index 000000000..ef443b57f
--- /dev/null
+++ b/lib/math/tests/polynomial_kunit.c
@@ -0,0 +1,270 @@
+// SPDX-License-Identifier: GPL-2.0-only
+
+#include <kunit/test.h>
+#include <linux/polynomial.h>
+
+struct polynomial_test_param {
+	const struct polynomial *poly;
+	long data;
+	long expected;
+	const char *name;
+};
+
+/* f(x) = 5 */
+static const struct polynomial poly_constant = {
+	.total_divider = 1,
+	.terms = {
+		{0, 5, 1, 1},
+	}
+};
+
+/* f(x) = 2x^2 + 3x + 5 */
+static const struct polynomial poly_simple = {
+	.total_divider = 1,
+	.terms = {
+		{2, 2, 1, 1},
+		{1, 3, 1, 1},
+		{0, 5, 1, 1},
+	}
+};
+
+/* f(x) = -5x + 100 */
+static const struct polynomial poly_negative_coef = {
+	.total_divider = 1,
+	.terms = {
+		{1, -5, 1, 1},
+		{0, 100, 1, 1},
+	}
+};
+
+/* f(x) = (150x + 50) / 10 */
+static const struct polynomial poly_total_divider = {
+	.total_divider = 10,
+	.terms = {
+		{1, 150, 1, 1},
+		{0,  50, 1, 1},
+	}
+};
+
+/*
+ * f(x) = x / 2
+ * divider=2 applied once per multiply: mult_frac(coef, data, 2) = coef*data/2
+ */
+static const struct polynomial poly_step_divider = {
+	.total_divider = 1,
+	.terms = {
+		{1, 1, 2, 1},
+		{0, 0, 1, 1},
+	}
+};
+
+/*
+ * f(x) = (100/500) * x^2 = 0.2 * x^2
+ * Encoded as coef=100, divider=10, divider_leftover=5:
+ *   denom = 10^2 * 5 = 500
+ */
+static const struct polynomial poly_leftover = {
+	.total_divider = 1,
+	.terms = {
+		{2, 100, 10, 5},
+		{0,   0,  1, 1},
+	}
+};
+
+/*
+ * f(x) = 2x^3  (single high-degree term, no constant)
+ * Used to exercise the power loop alone.
+ */
+static const struct polynomial poly_cubic = {
+	.total_divider = 1,
+	.terms = {
+		{3, 2, 1, 1},
+		{0, 0, 1, 1},
+	}
+};
+
+/*
+ * f(x) = 4x + 1  with a zero-coefficient quadratic term.
+ * The deg-2 term contributes nothing regardless of input.
+ */
+static const struct polynomial poly_zero_coef = {
+	.total_divider = 1,
+	.terms = {
+		{2, 0, 1, 1},
+		{1, 4, 1, 1},
+		{0, 1, 1, 1},
+	}
+};
+
+/*
+ * f(x) = 9  with total_divider = 0.
+ * The implementation treats 0 as 1 via `total_divider ?: 1`, so the
+ * result must equal the constant term unchanged.
+ */
+static const struct polynomial poly_zero_total_divider = {
+	.total_divider = 0,
+	.terms = {
+		{0, 9, 1, 1},
+	}
+};
+
+
+static const struct polynomial_test_param test_params[] = {
+	{
+		.poly     = &poly_constant,
+		.data     = 0,
+		.expected = 5,
+		.name     = "Constant polynomial at x=0",
+	},
+	{
+		.poly     = &poly_constant,
+		.data     = 42,
+		.expected = 5,
+		.name     = "Constant polynomial is independent of input",
+	},
+	{
+		.poly     = &poly_simple,
+		.data     = 0,
+		.expected = 5,	/* zero input collapses all power terms */
+		.name     = "Zero input yields constant term only",
+	},
+	{
+		.poly     = &poly_simple,
+		.data     = 10,
+		.expected = 235,	/* 2*100 + 3*10 + 5 */
+		.name     = "Simple quadratic at x=10",
+	},
+	{
+		.poly     = &poly_negative_coef,
+		.data     = 10,
+		.expected = 50,		/* -5*10 + 100 */
+		.name     = "Negative coefficient at x=10",
+	},
+	{
+		.poly     = &poly_negative_coef,
+		.data     = 20,
+		.expected = 0,		/* -5*20 + 100 = 0 */
+		.name     = "Negative coefficient result is zero",
+	},
+	{
+		.poly     = &poly_total_divider,
+		.data     = 3,
+		.expected = 50,		/* (150*3 + 50) / 10 = 500/10 */
+		.name     = "total_divider scales the final sum",
+	},
+	{
+		.poly     = &poly_step_divider,
+		.data     = 100,
+		.expected = 50,		/* 1*100/2 */
+		.name     = "Per-step divider halves input",
+	},
+	{
+		.poly     = &poly_leftover,
+		.data     = 30,
+		.expected = 180,	/* 100*30^2 / (10^2 * 5) = 90000/500 */
+		.name     = "divider_leftover with quadratic term",
+	},
+	/* Boundary: unit and negative-unit input */
+	{
+		/*
+		 * data=1: each mult_frac(tmp, 1, divider) strips one factor of
+		 * divider from coef per degree, so coef is left-shifted right
+		 * until intermediate precision is exhausted.
+		 * 2*1 + 3*1 + 5 = 10
+		 */
+		.poly     = &poly_simple,
+		.data     = 1,
+		.expected = 10,
+		.name     = "Boundary: data=1 (unit input)",
+	},
+	{
+		/*
+		 * data=-1: even degrees produce positive contributions,
+		 * odd degrees produce negative ones.
+		 * 2*(-1)^2 + 3*(-1) + 5 = 2 - 3 + 5 = 4
+		 */
+		.poly     = &poly_simple,
+		.data     = -1,
+		.expected = 4,
+		.name     = "Boundary: data=-1 (negative unit input)",
+	},
+
+	/* Boundary: negative non-trivial input */
+	{
+		/*
+		 * 2*(-3)^2 + 3*(-3) + 5 = 18 - 9 + 5 = 14
+		 * Verifies sign handling for negative data across all degrees.
+		 */
+		.poly     = &poly_simple,
+		.data     = -3,
+		.expected = 14,
+		.name     = "Boundary: negative data with quadratic",
+	},
+
+	/* Boundary: total_divider = 0 is treated as 1 */
+	{
+		.poly     = &poly_zero_total_divider,
+		.data     = 42,
+		.expected = 9,
+		.name     = "Boundary: total_divider=0 defaults to 1",
+	},
+
+	/* Boundary: zero-coefficient high-degree term */
+	{
+		/*
+		 * The deg-2 term has coef=0, so it contributes 0 regardless
+		 * of data. Result: 0 + 4*10 + 1 = 41
+		 */
+		.poly     = &poly_zero_coef,
+		.data     = 10,
+		.expected = 41,
+		.name     = "Boundary: zero-coefficient term is inert",
+	},
+
+	/* Boundary: single high-degree term, no constant */
+	{
+		/* 2 * 5^3 = 250; also verifies the loop terminates on deg-0 */
+		.poly     = &poly_cubic,
+		.data     = 5,
+		.expected = 250,
+		.name     = "Boundary: single cubic term",
+	},
+	{
+		/* 2 * (-2)^3 = -16; odd power preserves sign of negative data */
+		.poly     = &poly_cubic,
+		.data     = -2,
+		.expected = -16,
+		.name     = "Boundary: single cubic term, negative data",
+	},
+
+};
+
+static void get_desc(const struct polynomial_test_param *param, char *desc)
+{
+	strscpy(desc, param->name, KUNIT_PARAM_DESC_SIZE);
+}
+
+KUNIT_ARRAY_PARAM(polynomial, test_params, get_desc);
+
+static void polynomial_calc_test(struct kunit *test)
+{
+	const struct polynomial_test_param *param = test->param_value;
+
+	KUNIT_EXPECT_EQ(test, polynomial_calc(param->poly, param->data),
+			param->expected);
+}
+
+static struct kunit_case polynomial_test_cases[] = {
+	KUNIT_CASE_PARAM(polynomial_calc_test, polynomial_gen_params),
+	{}
+};
+
+static struct kunit_suite polynomial_test_suite = {
+	.name = "math-polynomial",
+	.test_cases = polynomial_test_cases,
+};
+
+kunit_test_suites(&polynomial_test_suite);
+
+MODULE_DESCRIPTION("math.polynomial_calc KUnit test suite");
+MODULE_LICENSE("GPL");
diff --git a/lib/math/tests/prime_numbers_kunit.c b/lib/math/tests/prime_numbers_kunit.c
new file mode 100644
index 000000000..55ac160c6
--- /dev/null
+++ b/lib/math/tests/prime_numbers_kunit.c
@@ -0,0 +1,57 @@
+// SPDX-License-Identifier: GPL-2.0-only
+
+#include <kunit/test.h>
+#include <linux/module.h>
+#include <linux/prime_numbers.h>
+
+#include "../prime_numbers_private.h"
+
+static void dump_primes(void *ctx, const struct primes *p)
+{
+	struct kunit_suite *suite = ctx;
+
+	kunit_info(suite, "primes.{last=%lu, .sz=%lu, .primes[]=...x%lx} = %*pbl",
+		   p->last, p->sz, p->primes[BITS_TO_LONGS(p->sz) - 1], (int)p->sz, p->primes);
+}
+
+static void prime_numbers_test(struct kunit *test)
+{
+	const unsigned long max = 65536;
+	unsigned long x, last, next;
+
+	for (last = 0, x = 2; x < max; x++) {
+		const bool slow = slow_is_prime_number(x);
+		const bool fast = is_prime_number(x);
+
+		KUNIT_ASSERT_EQ_MSG(test, slow, fast, "is-prime(%lu)", x);
+
+		if (!slow)
+			continue;
+
+		next = next_prime_number(last);
+		KUNIT_ASSERT_EQ_MSG(test, next, x, "next-prime(%lu)", last);
+		last = next;
+	}
+}
+
+static void kunit_suite_exit(struct kunit_suite *suite)
+{
+	with_primes(suite, dump_primes);
+}
+
+static struct kunit_case prime_numbers_cases[] = {
+	KUNIT_CASE(prime_numbers_test),
+	{},
+};
+
+static struct kunit_suite prime_numbers_suite = {
+	.name = "math-prime_numbers",
+	.suite_exit = kunit_suite_exit,
+	.test_cases = prime_numbers_cases,
+};
+
+kunit_test_suite(prime_numbers_suite);
+
+MODULE_AUTHOR("Intel Corporation");
+MODULE_DESCRIPTION("Prime number library");
+MODULE_LICENSE("GPL");
diff --git a/lib/math/tests/rational_kunit.c b/lib/math/tests/rational_kunit.c
new file mode 100644
index 000000000..47486a95f
--- /dev/null
+++ b/lib/math/tests/rational_kunit.c
@@ -0,0 +1,57 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <kunit/test.h>
+
+#include <linux/rational.h>
+
+struct rational_test_param {
+	unsigned long num, den;
+	unsigned long max_num, max_den;
+	unsigned long exp_num, exp_den;
+
+	const char *name;
+};
+
+static const struct rational_test_param test_parameters[] = {
+	{ 1230,	10,	100, 20,	100, 1,    "Exceeds bounds, semi-convergent term > 1/2 last term" },
+	{ 34567,100, 	120, 20,	120, 1,    "Exceeds bounds, semi-convergent term < 1/2 last term" },
+	{ 1, 30,	100, 10,	0, 1,	   "Closest to zero" },
+	{ 1, 19,	100, 10,	1, 10,     "Closest to smallest non-zero" },
+	{ 27,32,	16, 16,		11, 13,    "Use convergent" },
+	{ 1155, 7735,	255, 255,	33, 221,   "Exact answer" },
+	{ 87, 32,	70, 32,		68, 25,    "Semiconvergent, numerator limit" },
+	{ 14533, 4626,	15000, 2400,	7433, 2366, "Semiconvergent, denominator limit" },
+};
+
+static void get_desc(const struct rational_test_param *param, char *desc)
+{
+	strscpy(desc, param->name, KUNIT_PARAM_DESC_SIZE);
+}
+
+/* Creates function rational_gen_params */
+KUNIT_ARRAY_PARAM(rational, test_parameters, get_desc);
+
+static void rational_test(struct kunit *test)
+{
+	const struct rational_test_param *param = (const struct rational_test_param *)test->param_value;
+	unsigned long n = 0, d = 0;
+
+	rational_best_approximation(param->num, param->den, param->max_num, param->max_den, &n, &d);
+	KUNIT_EXPECT_EQ(test, n, param->exp_num);
+	KUNIT_EXPECT_EQ(test, d, param->exp_den);
+}
+
+static struct kunit_case rational_test_cases[] = {
+	KUNIT_CASE_PARAM(rational_test, rational_gen_params),
+	{}
+};
+
+static struct kunit_suite rational_test_suite = {
+	.name = "rational",
+	.test_cases = rational_test_cases,
+};
+
+kunit_test_suites(&rational_test_suite);
+
+MODULE_DESCRIPTION("Rational fractions unit test");
+MODULE_LICENSE("GPL v2");