From 5d042707089f0d0c49473d05250e4f319a71e1df Mon Sep 17 00:00:00 2001 From: Vinicius Peixoto Date: Sat, 12 Oct 2024 04:43:49 -0300 Subject: [PATCH] lib/crc16_kunit.c: add KUnit tests for crc16 Add Kunit tests for the kernel's implementation of the standard CRC-16 algorithm (). The test data consists of 100 randomly-generated test cases, validated against a naive CRC-16 implementation. This test follows roughly the same logic as lib/crc32test.c, but without the performance measurements. Link: https://lkml.kernel.org/r/20241012-crc16-kunit-v3-1-0ca75cb58ca9@lkcamp.dev Signed-off-by: Vinicius Peixoto Co-developed-by: Enzo Bertoloti Signed-off-by: Enzo Bertoloti Co-developed-by: Fabricio Gasperin Signed-off-by: Fabricio Gasperin Suggested-by: David Laight Cc: Brendan Higgins Cc: David Gow Cc: Rae Moar Signed-off-by: Andrew Morton --- lib/Kconfig.debug | 9 +++ lib/Makefile | 1 + lib/crc16_kunit.c | 155 ++++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 165 insertions(+) create mode 100644 lib/crc16_kunit.c diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index 409dd193c09b..eda319e9d569 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -2850,6 +2850,15 @@ config USERCOPY_KUNIT_TEST on the copy_to/from_user infrastructure, making sure basic user/kernel boundary testing is working. +config CRC16_KUNIT_TEST + tristate "KUnit tests for CRC16" + depends on KUNIT + default KUNIT_ALL_TESTS + select CRC16 + help + Enable this option to run unit tests for the kernel's CRC16 + implementation (). + config TEST_UDELAY tristate "udelay test driver" help diff --git a/lib/Makefile b/lib/Makefile index 773adf88af41..1faed6414a85 100644 --- a/lib/Makefile +++ b/lib/Makefile @@ -389,6 +389,7 @@ CFLAGS_fortify_kunit.o += $(DISABLE_STRUCTLEAK_PLUGIN) obj-$(CONFIG_FORTIFY_KUNIT_TEST) += fortify_kunit.o obj-$(CONFIG_SIPHASH_KUNIT_TEST) += siphash_kunit.o obj-$(CONFIG_USERCOPY_KUNIT_TEST) += usercopy_kunit.o +obj-$(CONFIG_CRC16_KUNIT_TEST) += crc16_kunit.o obj-$(CONFIG_GENERIC_LIB_DEVMEM_IS_ALLOWED) += devmem_is_allowed.o diff --git a/lib/crc16_kunit.c b/lib/crc16_kunit.c new file mode 100644 index 000000000000..0918c98a96d2 --- /dev/null +++ b/lib/crc16_kunit.c @@ -0,0 +1,155 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * KUnits tests for CRC16. + * + * Copyright (C) 2024, LKCAMP + * Author: Vinicius Peixoto + * Author: Fabricio Gasperin + * Author: Enzo Bertoloti + */ +#include +#include +#include + +#define CRC16_KUNIT_DATA_SIZE 4096 +#define CRC16_KUNIT_TEST_SIZE 100 +#define CRC16_KUNIT_SEED 0x12345678 + +/** + * struct crc16_test - CRC16 test data + * @crc: initial input value to CRC16 + * @start: Start index within the data buffer + * @length: Length of the data + */ +static struct crc16_test { + u16 crc; + u16 start; + u16 length; +} tests[CRC16_KUNIT_TEST_SIZE]; + +u8 data[CRC16_KUNIT_DATA_SIZE]; + + +/* Naive implementation of CRC16 for validation purposes */ +static inline u16 _crc16_naive_byte(u16 crc, u8 data) +{ + u8 i = 0; + + crc ^= (u16) data; + for (i = 0; i < 8; i++) { + if (crc & 0x01) + crc = (crc >> 1) ^ 0xa001; + else + crc = crc >> 1; + } + + return crc; +} + + +static inline u16 _crc16_naive(u16 crc, u8 *buffer, size_t len) +{ + while (len--) + crc = _crc16_naive_byte(crc, *buffer++); + return crc; +} + + +/* Small helper for generating pseudorandom 16-bit data */ +static inline u16 _rand16(void) +{ + static u32 rand = CRC16_KUNIT_SEED; + + rand = next_pseudo_random32(rand); + return rand & 0xFFFF; +} + + +static int crc16_init_test_data(struct kunit_suite *suite) +{ + size_t i; + + /* Fill the data buffer with random bytes */ + for (i = 0; i < CRC16_KUNIT_DATA_SIZE; i++) + data[i] = _rand16() & 0xFF; + + /* Generate random test data while ensuring the random + * start + length values won't overflow the 4096-byte + * buffer (0x7FF * 2 = 0xFFE < 0x1000) + */ + for (size_t i = 0; i < CRC16_KUNIT_TEST_SIZE; i++) { + tests[i].crc = _rand16(); + tests[i].start = _rand16() & 0x7FF; + tests[i].length = _rand16() & 0x7FF; + } + + return 0; +} + +static void crc16_test_empty(struct kunit *test) +{ + u16 crc; + + /* The result for empty data should be the same as the + * initial crc + */ + crc = crc16(0x00, data, 0); + KUNIT_EXPECT_EQ(test, crc, 0); + crc = crc16(0xFF, data, 0); + KUNIT_EXPECT_EQ(test, crc, 0xFF); +} + +static void crc16_test_correctness(struct kunit *test) +{ + size_t i; + u16 crc, crc_naive; + + for (i = 0; i < CRC16_KUNIT_TEST_SIZE; i++) { + /* Compare results with the naive crc16 implementation */ + crc = crc16(tests[i].crc, data + tests[i].start, + tests[i].length); + crc_naive = _crc16_naive(tests[i].crc, data + tests[i].start, + tests[i].length); + KUNIT_EXPECT_EQ(test, crc, crc_naive); + } +} + + +static void crc16_test_combine(struct kunit *test) +{ + size_t i, j; + u16 crc, crc_naive; + + /* Make sure that combining two consecutive crc16 calculations + * yields the same result as calculating the crc16 for the whole thing + */ + for (i = 0; i < CRC16_KUNIT_TEST_SIZE; i++) { + crc_naive = crc16(tests[i].crc, data + tests[i].start, tests[i].length); + for (j = 0; j < tests[i].length; j++) { + crc = crc16(tests[i].crc, data + tests[i].start, j); + crc = crc16(crc, data + tests[i].start + j, tests[i].length - j); + KUNIT_EXPECT_EQ(test, crc, crc_naive); + } + } +} + + +static struct kunit_case crc16_test_cases[] = { + KUNIT_CASE(crc16_test_empty), + KUNIT_CASE(crc16_test_combine), + KUNIT_CASE(crc16_test_correctness), + {}, +}; + +static struct kunit_suite crc16_test_suite = { + .name = "crc16", + .test_cases = crc16_test_cases, + .suite_init = crc16_init_test_data, +}; +kunit_test_suite(crc16_test_suite); + +MODULE_AUTHOR("Fabricio Gasperin "); +MODULE_AUTHOR("Vinicius Peixoto "); +MODULE_AUTHOR("Enzo Bertoloti "); +MODULE_DESCRIPTION("Unit tests for crc16"); +MODULE_LICENSE("GPL");