Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
lib/crc16_kunit.c: add KUnit tests for crc16
Add Kunit tests for the kernel's implementation of the standard CRC-16
algorithm (<linux/crc16.h>). 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 <vpeixoto@lkcamp.dev>
Co-developed-by: Enzo Bertoloti <ebertoloti@lkcamp.dev>
Signed-off-by: Enzo Bertoloti <ebertoloti@lkcamp.dev>
Co-developed-by: Fabricio Gasperin <fgasperin@lkcamp.dev>
Signed-off-by: Fabricio Gasperin <fgasperin@lkcamp.dev>
Suggested-by: David Laight <David.Laight@ACULAB.COM>
Cc: Brendan Higgins <brendan.higgins@linux.dev>
Cc: David Gow <davidgow@google.com>
Cc: Rae Moar <rmoar@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
authored by
Vinicius Peixoto
and committed by
Andrew Morton
5d042707
a9d38bcd
+165
+9
lib/Kconfig.debug
+9
lib/Kconfig.debug
···
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on the copy_to/from_user infrastructure, making sure basic
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user/kernel boundary testing is working.
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config CRC16_KUNIT_TEST
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tristate "KUnit tests for CRC16"
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depends on KUNIT
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default KUNIT_ALL_TESTS
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select CRC16
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help
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Enable this option to run unit tests for the kernel's CRC16
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implementation (<linux/crc16.h>).
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config TEST_UDELAY
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tristate "udelay test driver"
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help
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lib/Makefile
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lib/Makefile
···
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obj-$(CONFIG_FORTIFY_KUNIT_TEST) += fortify_kunit.o
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obj-$(CONFIG_SIPHASH_KUNIT_TEST) += siphash_kunit.o
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obj-$(CONFIG_USERCOPY_KUNIT_TEST) += usercopy_kunit.o
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obj-$(CONFIG_CRC16_KUNIT_TEST) += crc16_kunit.o
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obj-$(CONFIG_GENERIC_LIB_DEVMEM_IS_ALLOWED) += devmem_is_allowed.o
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+155
lib/crc16_kunit.c
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lib/crc16_kunit.c
···
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// SPDX-License-Identifier: GPL-2.0
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/*
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* KUnits tests for CRC16.
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*
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* Copyright (C) 2024, LKCAMP
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* Author: Vinicius Peixoto <vpeixoto@lkcamp.dev>
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* Author: Fabricio Gasperin <fgasperin@lkcamp.dev>
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* Author: Enzo Bertoloti <ebertoloti@lkcamp.dev>
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*/
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#include <kunit/test.h>
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#include <linux/crc16.h>
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#include <linux/prandom.h>
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+
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#define CRC16_KUNIT_DATA_SIZE 4096
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#define CRC16_KUNIT_TEST_SIZE 100
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#define CRC16_KUNIT_SEED 0x12345678
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/**
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* struct crc16_test - CRC16 test data
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* @crc: initial input value to CRC16
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* @start: Start index within the data buffer
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* @length: Length of the data
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*/
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static struct crc16_test {
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u16 crc;
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u16 start;
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u16 length;
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} tests[CRC16_KUNIT_TEST_SIZE];
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u8 data[CRC16_KUNIT_DATA_SIZE];
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/* Naive implementation of CRC16 for validation purposes */
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static inline u16 _crc16_naive_byte(u16 crc, u8 data)
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{
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u8 i = 0;
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crc ^= (u16) data;
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for (i = 0; i < 8; i++) {
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if (crc & 0x01)
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crc = (crc >> 1) ^ 0xa001;
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else
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crc = crc >> 1;
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}
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return crc;
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}
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static inline u16 _crc16_naive(u16 crc, u8 *buffer, size_t len)
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{
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while (len--)
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crc = _crc16_naive_byte(crc, *buffer++);
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return crc;
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}
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/* Small helper for generating pseudorandom 16-bit data */
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static inline u16 _rand16(void)
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{
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static u32 rand = CRC16_KUNIT_SEED;
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rand = next_pseudo_random32(rand);
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return rand & 0xFFFF;
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}
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static int crc16_init_test_data(struct kunit_suite *suite)
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{
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size_t i;
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/* Fill the data buffer with random bytes */
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for (i = 0; i < CRC16_KUNIT_DATA_SIZE; i++)
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data[i] = _rand16() & 0xFF;
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/* Generate random test data while ensuring the random
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* start + length values won't overflow the 4096-byte
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* buffer (0x7FF * 2 = 0xFFE < 0x1000)
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*/
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for (size_t i = 0; i < CRC16_KUNIT_TEST_SIZE; i++) {
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tests[i].crc = _rand16();
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tests[i].start = _rand16() & 0x7FF;
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tests[i].length = _rand16() & 0x7FF;
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}
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return 0;
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}
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static void crc16_test_empty(struct kunit *test)
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{
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u16 crc;
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/* The result for empty data should be the same as the
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* initial crc
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*/
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crc = crc16(0x00, data, 0);
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KUNIT_EXPECT_EQ(test, crc, 0);
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crc = crc16(0xFF, data, 0);
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KUNIT_EXPECT_EQ(test, crc, 0xFF);
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}
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static void crc16_test_correctness(struct kunit *test)
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{
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size_t i;
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u16 crc, crc_naive;
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for (i = 0; i < CRC16_KUNIT_TEST_SIZE; i++) {
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/* Compare results with the naive crc16 implementation */
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crc = crc16(tests[i].crc, data + tests[i].start,
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tests[i].length);
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crc_naive = _crc16_naive(tests[i].crc, data + tests[i].start,
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tests[i].length);
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KUNIT_EXPECT_EQ(test, crc, crc_naive);
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}
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}
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static void crc16_test_combine(struct kunit *test)
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{
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size_t i, j;
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u16 crc, crc_naive;
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/* Make sure that combining two consecutive crc16 calculations
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* yields the same result as calculating the crc16 for the whole thing
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*/
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for (i = 0; i < CRC16_KUNIT_TEST_SIZE; i++) {
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crc_naive = crc16(tests[i].crc, data + tests[i].start, tests[i].length);
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for (j = 0; j < tests[i].length; j++) {
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crc = crc16(tests[i].crc, data + tests[i].start, j);
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crc = crc16(crc, data + tests[i].start + j, tests[i].length - j);
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KUNIT_EXPECT_EQ(test, crc, crc_naive);
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}
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}
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}
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static struct kunit_case crc16_test_cases[] = {
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KUNIT_CASE(crc16_test_empty),
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KUNIT_CASE(crc16_test_combine),
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KUNIT_CASE(crc16_test_correctness),
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{},
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};
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static struct kunit_suite crc16_test_suite = {
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.name = "crc16",
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.test_cases = crc16_test_cases,
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.suite_init = crc16_init_test_data,
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};
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kunit_test_suite(crc16_test_suite);
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MODULE_AUTHOR("Fabricio Gasperin <fgasperin@lkcamp.dev>");
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MODULE_AUTHOR("Vinicius Peixoto <vpeixoto@lkcamp.dev>");
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MODULE_AUTHOR("Enzo Bertoloti <ebertoloti@lkcamp.dev>");
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MODULE_DESCRIPTION("Unit tests for crc16");
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MODULE_LICENSE("GPL");