mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git
synced 2024-12-28 00:32:00 +00:00
lib/crc_kunit.c: add KUnit test suite for CRC library functions
Add a KUnit test suite for the crc16, crc_t10dif, crc32_le, crc32_be, crc32c, and crc64_be library functions. It avoids code duplication by sharing most logic among all CRC variants. The test suite includes: - Differential fuzz test of each CRC function against a simple bit-at-a-time reference implementation. - Test for CRC combination, when implemented by a CRC variant. - Optional benchmark of each CRC function with various data lengths. This is intended as a replacement for crc32test and crc16_kunit, as well as a new test for CRC variants which didn't previously have a test. Reviewed-by: Ard Biesheuvel <ardb@kernel.org> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Cc: Vinicius Peixoto <vpeixoto@lkcamp.dev> Link: https://lore.kernel.org/r/20241202012056.209768-9-ebiggers@kernel.org Signed-off-by: Eric Biggers <ebiggers@google.com>
This commit is contained in:
Eric Biggers
parent
7439cfed1c
commit
e47d9b1a76
@ -2838,6 +2838,26 @@ config HW_BREAKPOINT_KUNIT_TEST
|
||||
|
||||
If unsure, say N.
|
||||
|
||||
config CRC_KUNIT_TEST
|
||||
tristate "KUnit tests for CRC functions" if !KUNIT_ALL_TESTS
|
||||
depends on KUNIT
|
||||
default KUNIT_ALL_TESTS
|
||||
select CRC16
|
||||
select CRC_T10DIF
|
||||
select CRC32
|
||||
select CRC64
|
||||
help
|
||||
Unit tests for the CRC library functions.
|
||||
|
||||
This is intended to help people writing architecture-specific
|
||||
optimized versions. If unsure, say N.
|
||||
|
||||
config CRC_BENCHMARK
|
||||
bool "Benchmark for the CRC functions"
|
||||
depends on CRC_KUNIT_TEST
|
||||
help
|
||||
Include benchmarks in the KUnit test suite for the CRC functions.
|
||||
|
||||
config SIPHASH_KUNIT_TEST
|
||||
tristate "Perform selftest on siphash functions" if !KUNIT_ALL_TESTS
|
||||
depends on KUNIT
|
||||
|
||||
@ -391,6 +391,7 @@ CFLAGS_fortify_kunit.o += $(call cc-disable-warning, stringop-overread)
|
||||
CFLAGS_fortify_kunit.o += $(call cc-disable-warning, stringop-truncation)
|
||||
CFLAGS_fortify_kunit.o += $(DISABLE_STRUCTLEAK_PLUGIN)
|
||||
obj-$(CONFIG_FORTIFY_KUNIT_TEST) += fortify_kunit.o
|
||||
obj-$(CONFIG_CRC_KUNIT_TEST) += crc_kunit.o
|
||||
obj-$(CONFIG_SIPHASH_KUNIT_TEST) += siphash_kunit.o
|
||||
obj-$(CONFIG_USERCOPY_KUNIT_TEST) += usercopy_kunit.o
|
||||
obj-$(CONFIG_CRC16_KUNIT_TEST) += crc16_kunit.o
|
||||
|
||||
435
lib/crc_kunit.c
Normal file
435
lib/crc_kunit.c
Normal file
@ -0,0 +1,435 @@
|
||||
// SPDX-License-Identifier: GPL-2.0-or-later
|
||||
/*
|
||||
* Unit tests and benchmarks for the CRC library functions
|
||||
*
|
||||
* Copyright 2024 Google LLC
|
||||
*
|
||||
* Author: Eric Biggers <ebiggers@google.com>
|
||||
*/
|
||||
#include <kunit/test.h>
|
||||
#include <linux/crc16.h>
|
||||
#include <linux/crc-t10dif.h>
|
||||
#include <linux/crc32.h>
|
||||
#include <linux/crc32c.h>
|
||||
#include <linux/crc64.h>
|
||||
#include <linux/prandom.h>
|
||||
#include <linux/vmalloc.h>
|
||||
|
||||
#define CRC_KUNIT_SEED 42
|
||||
#define CRC_KUNIT_MAX_LEN 16384
|
||||
#define CRC_KUNIT_NUM_TEST_ITERS 1000
|
||||
|
||||
static struct rnd_state rng;
|
||||
static u8 *test_buffer;
|
||||
static size_t test_buflen;
|
||||
|
||||
/**
|
||||
* struct crc_variant - describes a CRC variant
|
||||
* @bits: Number of bits in the CRC, 1 <= @bits <= 64.
|
||||
* @le: true if it's a "little endian" CRC (reversed mapping between bits and
|
||||
* polynomial coefficients in each byte), false if it's a "big endian" CRC
|
||||
* (natural mapping between bits and polynomial coefficients in each byte)
|
||||
* @poly: The generator polynomial with the highest-order term omitted.
|
||||
* Bit-reversed if @le is true.
|
||||
* @func: The function to compute a CRC. The type signature uses u64 so that it
|
||||
* can fit any CRC up to CRC-64.
|
||||
* @combine_func: Optional function to combine two CRCs.
|
||||
*/
|
||||
struct crc_variant {
|
||||
int bits;
|
||||
bool le;
|
||||
u64 poly;
|
||||
u64 (*func)(u64 crc, const u8 *p, size_t len);
|
||||
u64 (*combine_func)(u64 crc1, u64 crc2, size_t len2);
|
||||
};
|
||||
|
||||
static u32 rand32(void)
|
||||
{
|
||||
return prandom_u32_state(&rng);
|
||||
}
|
||||
|
||||
static u64 rand64(void)
|
||||
{
|
||||
u32 n = rand32();
|
||||
|
||||
return ((u64)n << 32) | rand32();
|
||||
}
|
||||
|
||||
static u64 crc_mask(const struct crc_variant *v)
|
||||
{
|
||||
return (u64)-1 >> (64 - v->bits);
|
||||
}
|
||||
|
||||
/* Reference implementation of any CRC variant */
|
||||
static u64 crc_ref(const struct crc_variant *v,
|
||||
u64 crc, const u8 *p, size_t len)
|
||||
{
|
||||
size_t i, j;
|
||||
|
||||
for (i = 0; i < len; i++) {
|
||||
for (j = 0; j < 8; j++) {
|
||||
if (v->le) {
|
||||
crc ^= (p[i] >> j) & 1;
|
||||
crc = (crc >> 1) ^ ((crc & 1) ? v->poly : 0);
|
||||
} else {
|
||||
crc ^= (u64)((p[i] >> (7 - j)) & 1) <<
|
||||
(v->bits - 1);
|
||||
if (crc & (1ULL << (v->bits - 1)))
|
||||
crc = ((crc << 1) ^ v->poly) &
|
||||
crc_mask(v);
|
||||
else
|
||||
crc <<= 1;
|
||||
}
|
||||
}
|
||||
}
|
||||
return crc;
|
||||
}
|
||||
|
||||
static int crc_suite_init(struct kunit_suite *suite)
|
||||
{
|
||||
/*
|
||||
* Allocate the test buffer using vmalloc() with a page-aligned length
|
||||
* so that it is immediately followed by a guard page. This allows
|
||||
* buffer overreads to be detected, even in assembly code.
|
||||
*/
|
||||
test_buflen = round_up(CRC_KUNIT_MAX_LEN, PAGE_SIZE);
|
||||
test_buffer = vmalloc(test_buflen);
|
||||
if (!test_buffer)
|
||||
return -ENOMEM;
|
||||
|
||||
prandom_seed_state(&rng, CRC_KUNIT_SEED);
|
||||
prandom_bytes_state(&rng, test_buffer, test_buflen);
|
||||
return 0;
|
||||
}
|
||||
|
||||
static void crc_suite_exit(struct kunit_suite *suite)
|
||||
{
|
||||
vfree(test_buffer);
|
||||
test_buffer = NULL;
|
||||
}
|
||||
|
||||
/* Generate a random initial CRC. */
|
||||
static u64 generate_random_initial_crc(const struct crc_variant *v)
|
||||
{
|
||||
switch (rand32() % 4) {
|
||||
case 0:
|
||||
return 0;
|
||||
case 1:
|
||||
return crc_mask(v); /* All 1 bits */
|
||||
default:
|
||||
return rand64() & crc_mask(v);
|
||||
}
|
||||
}
|
||||
|
||||
/* Generate a random length, preferring small lengths. */
|
||||
static size_t generate_random_length(size_t max_length)
|
||||
{
|
||||
size_t len;
|
||||
|
||||
switch (rand32() % 3) {
|
||||
case 0:
|
||||
len = rand32() % 128;
|
||||
break;
|
||||
case 1:
|
||||
len = rand32() % 3072;
|
||||
break;
|
||||
default:
|
||||
len = rand32();
|
||||
break;
|
||||
}
|
||||
return len % (max_length + 1);
|
||||
}
|
||||
|
||||
/* Test that v->func gives the same CRCs as a reference implementation. */
|
||||
static void crc_main_test(struct kunit *test, const struct crc_variant *v)
|
||||
{
|
||||
size_t i;
|
||||
|
||||
for (i = 0; i < CRC_KUNIT_NUM_TEST_ITERS; i++) {
|
||||
u64 init_crc, expected_crc, actual_crc;
|
||||
size_t len, offset;
|
||||
bool nosimd;
|
||||
|
||||
init_crc = generate_random_initial_crc(v);
|
||||
len = generate_random_length(CRC_KUNIT_MAX_LEN);
|
||||
|
||||
/* Generate a random offset. */
|
||||
if (rand32() % 2 == 0) {
|
||||
/* Use a random alignment mod 64 */
|
||||
offset = rand32() % 64;
|
||||
offset = min(offset, CRC_KUNIT_MAX_LEN - len);
|
||||
} else {
|
||||
/* Go up to the guard page, to catch buffer overreads */
|
||||
offset = test_buflen - len;
|
||||
}
|
||||
|
||||
if (rand32() % 8 == 0)
|
||||
/* Refresh the data occasionally. */
|
||||
prandom_bytes_state(&rng, &test_buffer[offset], len);
|
||||
|
||||
nosimd = rand32() % 8 == 0;
|
||||
|
||||
/*
|
||||
* Compute the CRC, and verify that it equals the CRC computed
|
||||
* by a simple bit-at-a-time reference implementation.
|
||||
*/
|
||||
expected_crc = crc_ref(v, init_crc, &test_buffer[offset], len);
|
||||
if (nosimd)
|
||||
local_irq_disable();
|
||||
actual_crc = v->func(init_crc, &test_buffer[offset], len);
|
||||
if (nosimd)
|
||||
local_irq_enable();
|
||||
KUNIT_EXPECT_EQ_MSG(test, expected_crc, actual_crc,
|
||||
"Wrong result with len=%zu offset=%zu nosimd=%d",
|
||||
len, offset, nosimd);
|
||||
}
|
||||
}
|
||||
|
||||
/* Test that CRC(concat(A, B)) == combine_CRCs(CRC(A), CRC(B), len(B)). */
|
||||
static void crc_combine_test(struct kunit *test, const struct crc_variant *v)
|
||||
{
|
||||
int i;
|
||||
|
||||
for (i = 0; i < 100; i++) {
|
||||
u64 init_crc = generate_random_initial_crc(v);
|
||||
size_t len1 = generate_random_length(CRC_KUNIT_MAX_LEN);
|
||||
size_t len2 = generate_random_length(CRC_KUNIT_MAX_LEN - len1);
|
||||
u64 crc1, crc2, expected_crc, actual_crc;
|
||||
|
||||
prandom_bytes_state(&rng, test_buffer, len1 + len2);
|
||||
crc1 = v->func(init_crc, test_buffer, len1);
|
||||
crc2 = v->func(0, &test_buffer[len1], len2);
|
||||
expected_crc = v->func(init_crc, test_buffer, len1 + len2);
|
||||
actual_crc = v->combine_func(crc1, crc2, len2);
|
||||
KUNIT_EXPECT_EQ_MSG(test, expected_crc, actual_crc,
|
||||
"CRC combination gave wrong result with len1=%zu len2=%zu\n",
|
||||
len1, len2);
|
||||
}
|
||||
}
|
||||
|
||||
static void crc_test(struct kunit *test, const struct crc_variant *v)
|
||||
{
|
||||
crc_main_test(test, v);
|
||||
if (v->combine_func)
|
||||
crc_combine_test(test, v);
|
||||
}
|
||||
|
||||
static __always_inline void
|
||||
crc_benchmark(struct kunit *test,
|
||||
u64 (*crc_func)(u64 crc, const u8 *p, size_t len))
|
||||
{
|
||||
static const size_t lens_to_test[] = {
|
||||
1, 16, 64, 127, 128, 200, 256, 511, 512, 1024, 3173, 4096, 16384,
|
||||
};
|
||||
size_t len, i, j, num_iters;
|
||||
/*
|
||||
* Some of the CRC library functions are marked as __pure, so use
|
||||
* volatile to ensure that all calls are really made as intended.
|
||||
*/
|
||||
volatile u64 crc = 0;
|
||||
u64 t;
|
||||
|
||||
if (!IS_ENABLED(CONFIG_CRC_BENCHMARK))
|
||||
kunit_skip(test, "not enabled");
|
||||
|
||||
/* warm-up */
|
||||
for (i = 0; i < 10000000; i += CRC_KUNIT_MAX_LEN)
|
||||
crc = crc_func(crc, test_buffer, CRC_KUNIT_MAX_LEN);
|
||||
|
||||
for (i = 0; i < ARRAY_SIZE(lens_to_test); i++) {
|
||||
len = lens_to_test[i];
|
||||
KUNIT_ASSERT_LE(test, len, CRC_KUNIT_MAX_LEN);
|
||||
num_iters = 10000000 / (len + 128);
|
||||
preempt_disable();
|
||||
t = ktime_get_ns();
|
||||
for (j = 0; j < num_iters; j++)
|
||||
crc = crc_func(crc, test_buffer, len);
|
||||
t = ktime_get_ns() - t;
|
||||
preempt_enable();
|
||||
kunit_info(test, "len=%zu: %llu MB/s\n",
|
||||
len, div64_u64((u64)len * num_iters * 1000, t));
|
||||
}
|
||||
}
|
||||
|
||||
/* crc16 */
|
||||
|
||||
static u64 crc16_wrapper(u64 crc, const u8 *p, size_t len)
|
||||
{
|
||||
return crc16(crc, p, len);
|
||||
}
|
||||
|
||||
static const struct crc_variant crc_variant_crc16 = {
|
||||
.bits = 16,
|
||||
.le = true,
|
||||
.poly = 0xa001,
|
||||
.func = crc16_wrapper,
|
||||
};
|
||||
|
||||
static void crc16_test(struct kunit *test)
|
||||
{
|
||||
crc_test(test, &crc_variant_crc16);
|
||||
}
|
||||
|
||||
static void crc16_benchmark(struct kunit *test)
|
||||
{
|
||||
crc_benchmark(test, crc16_wrapper);
|
||||
}
|
||||
|
||||
/* crc_t10dif */
|
||||
|
||||
static u64 crc_t10dif_wrapper(u64 crc, const u8 *p, size_t len)
|
||||
{
|
||||
return crc_t10dif_update(crc, p, len);
|
||||
}
|
||||
|
||||
static const struct crc_variant crc_variant_crc_t10dif = {
|
||||
.bits = 16,
|
||||
.le = false,
|
||||
.poly = 0x8bb7,
|
||||
.func = crc_t10dif_wrapper,
|
||||
};
|
||||
|
||||
static void crc_t10dif_test(struct kunit *test)
|
||||
{
|
||||
crc_test(test, &crc_variant_crc_t10dif);
|
||||
}
|
||||
|
||||
static void crc_t10dif_benchmark(struct kunit *test)
|
||||
{
|
||||
crc_benchmark(test, crc_t10dif_wrapper);
|
||||
}
|
||||
|
||||
/* crc32_le */
|
||||
|
||||
static u64 crc32_le_wrapper(u64 crc, const u8 *p, size_t len)
|
||||
{
|
||||
return crc32_le(crc, p, len);
|
||||
}
|
||||
|
||||
static u64 crc32_le_combine_wrapper(u64 crc1, u64 crc2, size_t len2)
|
||||
{
|
||||
return crc32_le_combine(crc1, crc2, len2);
|
||||
}
|
||||
|
||||
static const struct crc_variant crc_variant_crc32_le = {
|
||||
.bits = 32,
|
||||
.le = true,
|
||||
.poly = 0xedb88320,
|
||||
.func = crc32_le_wrapper,
|
||||
.combine_func = crc32_le_combine_wrapper,
|
||||
};
|
||||
|
||||
static void crc32_le_test(struct kunit *test)
|
||||
{
|
||||
crc_test(test, &crc_variant_crc32_le);
|
||||
}
|
||||
|
||||
static void crc32_le_benchmark(struct kunit *test)
|
||||
{
|
||||
crc_benchmark(test, crc32_le_wrapper);
|
||||
}
|
||||
|
||||
/* crc32_be */
|
||||
|
||||
static u64 crc32_be_wrapper(u64 crc, const u8 *p, size_t len)
|
||||
{
|
||||
return crc32_be(crc, p, len);
|
||||
}
|
||||
|
||||
static const struct crc_variant crc_variant_crc32_be = {
|
||||
.bits = 32,
|
||||
.le = false,
|
||||
.poly = 0x04c11db7,
|
||||
.func = crc32_be_wrapper,
|
||||
};
|
||||
|
||||
static void crc32_be_test(struct kunit *test)
|
||||
{
|
||||
crc_test(test, &crc_variant_crc32_be);
|
||||
}
|
||||
|
||||
static void crc32_be_benchmark(struct kunit *test)
|
||||
{
|
||||
crc_benchmark(test, crc32_be_wrapper);
|
||||
}
|
||||
|
||||
/* crc32c */
|
||||
|
||||
static u64 crc32c_wrapper(u64 crc, const u8 *p, size_t len)
|
||||
{
|
||||
return crc32c(crc, p, len);
|
||||
}
|
||||
|
||||
static u64 crc32c_combine_wrapper(u64 crc1, u64 crc2, size_t len2)
|
||||
{
|
||||
return __crc32c_le_combine(crc1, crc2, len2);
|
||||
}
|
||||
|
||||
static const struct crc_variant crc_variant_crc32c = {
|
||||
.bits = 32,
|
||||
.le = true,
|
||||
.poly = 0x82f63b78,
|
||||
.func = crc32c_wrapper,
|
||||
.combine_func = crc32c_combine_wrapper,
|
||||
};
|
||||
|
||||
static void crc32c_test(struct kunit *test)
|
||||
{
|
||||
crc_test(test, &crc_variant_crc32c);
|
||||
}
|
||||
|
||||
static void crc32c_benchmark(struct kunit *test)
|
||||
{
|
||||
crc_benchmark(test, crc32c_wrapper);
|
||||
}
|
||||
|
||||
/* crc64_be */
|
||||
|
||||
static u64 crc64_be_wrapper(u64 crc, const u8 *p, size_t len)
|
||||
{
|
||||
return crc64_be(crc, p, len);
|
||||
}
|
||||
|
||||
static const struct crc_variant crc_variant_crc64_be = {
|
||||
.bits = 64,
|
||||
.le = false,
|
||||
.poly = 0x42f0e1eba9ea3693,
|
||||
.func = crc64_be_wrapper,
|
||||
};
|
||||
|
||||
static void crc64_be_test(struct kunit *test)
|
||||
{
|
||||
crc_test(test, &crc_variant_crc64_be);
|
||||
}
|
||||
|
||||
static void crc64_be_benchmark(struct kunit *test)
|
||||
{
|
||||
crc_benchmark(test, crc64_be_wrapper);
|
||||
}
|
||||
|
||||
static struct kunit_case crc_test_cases[] = {
|
||||
KUNIT_CASE(crc16_test),
|
||||
KUNIT_CASE(crc16_benchmark),
|
||||
KUNIT_CASE(crc_t10dif_test),
|
||||
KUNIT_CASE(crc_t10dif_benchmark),
|
||||
KUNIT_CASE(crc32_le_test),
|
||||
KUNIT_CASE(crc32_le_benchmark),
|
||||
KUNIT_CASE(crc32_be_test),
|
||||
KUNIT_CASE(crc32_be_benchmark),
|
||||
KUNIT_CASE(crc32c_test),
|
||||
KUNIT_CASE(crc32c_benchmark),
|
||||
KUNIT_CASE(crc64_be_test),
|
||||
KUNIT_CASE(crc64_be_benchmark),
|
||||
{},
|
||||
};
|
||||
|
||||
static struct kunit_suite crc_test_suite = {
|
||||
.name = "crc",
|
||||
.test_cases = crc_test_cases,
|
||||
.suite_init = crc_suite_init,
|
||||
.suite_exit = crc_suite_exit,
|
||||
};
|
||||
kunit_test_suite(crc_test_suite);
|
||||
|
||||
MODULE_DESCRIPTION("Unit tests and benchmarks for the CRC library functions");
|
||||
MODULE_LICENSE("GPL");
|
||||
Loading…
Reference in New Issue
Block a user