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Diffstat (limited to 'lib/test_hash.c')
-rw-r--r-- | lib/test_hash.c | 239 |
1 files changed, 0 insertions, 239 deletions
diff --git a/lib/test_hash.c b/lib/test_hash.c deleted file mode 100644 index a7af39662a0a..000000000000 --- a/lib/test_hash.c +++ /dev/null @@ -1,239 +0,0 @@ -// SPDX-License-Identifier: GPL-2.0-only -/* - * Test cases for <linux/hash.h> and <linux/stringhash.h> - * This just verifies that various ways of computing a hash - * produce the same thing and, for cases where a k-bit hash - * value is requested, is of the requested size. - * - * We fill a buffer with a 255-byte null-terminated string, - * and use both full_name_hash() and hashlen_string() to hash the - * substrings from i to j, where 0 <= i < j < 256. - * - * The returned values are used to check that __hash_32() and - * __hash_32_generic() compute the same thing. Likewise hash_32() - * and hash_64(). - */ - -#include <linux/compiler.h> -#include <linux/types.h> -#include <linux/module.h> -#include <linux/hash.h> -#include <linux/stringhash.h> -#include <kunit/test.h> - -/* 32-bit XORSHIFT generator. Seed must not be zero. */ -static u32 __attribute_const__ -xorshift(u32 seed) -{ - seed ^= seed << 13; - seed ^= seed >> 17; - seed ^= seed << 5; - return seed; -} - -/* Given a non-zero x, returns a non-zero byte. */ -static u8 __attribute_const__ -mod255(u32 x) -{ - x = (x & 0xffff) + (x >> 16); /* 1 <= x <= 0x1fffe */ - x = (x & 0xff) + (x >> 8); /* 1 <= x <= 0x2fd */ - x = (x & 0xff) + (x >> 8); /* 1 <= x <= 0x100 */ - x = (x & 0xff) + (x >> 8); /* 1 <= x <= 0xff */ - return x; -} - -/* Fill the buffer with non-zero bytes. */ -static void fill_buf(char *buf, size_t len, u32 seed) -{ - size_t i; - - for (i = 0; i < len; i++) { - seed = xorshift(seed); - buf[i] = mod255(seed); - } -} - -/* Holds most testing variables for the int test. */ -struct test_hash_params { - /* Pointer to integer to be hashed. */ - unsigned long long *h64; - /* Low 32-bits of integer to be hashed. */ - u32 h0; - /* Arch-specific hash result. */ - u32 h1; - /* Generic hash result. */ - u32 h2; - /* ORed hashes of given size (in bits). */ - u32 (*hash_or)[33]; -}; - -#ifdef HAVE_ARCH__HASH_32 -static void -test_int__hash_32(struct kunit *test, struct test_hash_params *params) -{ - params->hash_or[1][0] |= params->h2 = __hash_32_generic(params->h0); -#if HAVE_ARCH__HASH_32 == 1 - KUNIT_EXPECT_EQ_MSG(test, params->h1, params->h2, - "__hash_32(%#x) = %#x != __hash_32_generic() = %#x", - params->h0, params->h1, params->h2); -#endif -} -#endif - -#ifdef HAVE_ARCH_HASH_64 -static void -test_int_hash_64(struct kunit *test, struct test_hash_params *params, u32 const *m, int *k) -{ - params->h2 = hash_64_generic(*params->h64, *k); -#if HAVE_ARCH_HASH_64 == 1 - KUNIT_EXPECT_EQ_MSG(test, params->h1, params->h2, - "hash_64(%#llx, %d) = %#x != hash_64_generic() = %#x", - *params->h64, *k, params->h1, params->h2); -#else - KUNIT_EXPECT_LE_MSG(test, params->h1, params->h2, - "hash_64_generic(%#llx, %d) = %#x > %#x", - *params->h64, *k, params->h1, *m); -#endif -} -#endif - -/* - * Test the various integer hash functions. h64 (or its low-order bits) - * is the integer to hash. hash_or accumulates the OR of the hash values, - * which are later checked to see that they cover all the requested bits. - * - * Because these functions (as opposed to the string hashes) are all - * inline, the code being tested is actually in the module, and you can - * recompile and re-test the module without rebooting. - */ -static void -test_int_hash(struct kunit *test, unsigned long long h64, u32 hash_or[2][33]) -{ - int k; - struct test_hash_params params = { &h64, (u32)h64, 0, 0, hash_or }; - - /* Test __hash32 */ - hash_or[0][0] |= params.h1 = __hash_32(params.h0); -#ifdef HAVE_ARCH__HASH_32 - test_int__hash_32(test, ¶ms); -#endif - - /* Test k = 1..32 bits */ - for (k = 1; k <= 32; k++) { - u32 const m = ((u32)2 << (k-1)) - 1; /* Low k bits set */ - - /* Test hash_32 */ - hash_or[0][k] |= params.h1 = hash_32(params.h0, k); - KUNIT_EXPECT_LE_MSG(test, params.h1, m, - "hash_32(%#x, %d) = %#x > %#x", - params.h0, k, params.h1, m); - - /* Test hash_64 */ - hash_or[1][k] |= params.h1 = hash_64(h64, k); - KUNIT_EXPECT_LE_MSG(test, params.h1, m, - "hash_64(%#llx, %d) = %#x > %#x", - h64, k, params.h1, m); -#ifdef HAVE_ARCH_HASH_64 - test_int_hash_64(test, ¶ms, &m, &k); -#endif - } -} - -#define SIZE 256 /* Run time is cubic in SIZE */ - -static void test_string_or(struct kunit *test) -{ - char buf[SIZE+1]; - u32 string_or = 0; - int i, j; - - fill_buf(buf, SIZE, 1); - - /* Test every possible non-empty substring in the buffer. */ - for (j = SIZE; j > 0; --j) { - buf[j] = '\0'; - - for (i = 0; i <= j; i++) { - u32 h0 = full_name_hash(buf+i, buf+i, j-i); - - string_or |= h0; - } /* i */ - } /* j */ - - /* The OR of all the hash values should cover all the bits */ - KUNIT_EXPECT_EQ_MSG(test, string_or, -1u, - "OR of all string hash results = %#x != %#x", - string_or, -1u); -} - -static void test_hash_or(struct kunit *test) -{ - char buf[SIZE+1]; - u32 hash_or[2][33] = { { 0, } }; - unsigned long long h64 = 0; - int i, j; - - fill_buf(buf, SIZE, 1); - - /* Test every possible non-empty substring in the buffer. */ - for (j = SIZE; j > 0; --j) { - buf[j] = '\0'; - - for (i = 0; i <= j; i++) { - u64 hashlen = hashlen_string(buf+i, buf+i); - u32 h0 = full_name_hash(buf+i, buf+i, j-i); - - /* Check that hashlen_string gets the length right */ - KUNIT_EXPECT_EQ_MSG(test, hashlen_len(hashlen), j-i, - "hashlen_string(%d..%d) returned length %u, expected %d", - i, j, hashlen_len(hashlen), j-i); - /* Check that the hashes match */ - KUNIT_EXPECT_EQ_MSG(test, hashlen_hash(hashlen), h0, - "hashlen_string(%d..%d) = %08x != full_name_hash() = %08x", - i, j, hashlen_hash(hashlen), h0); - - h64 = h64 << 32 | h0; /* For use with hash_64 */ - test_int_hash(test, h64, hash_or); - } /* i */ - } /* j */ - - KUNIT_EXPECT_EQ_MSG(test, hash_or[0][0], -1u, - "OR of all __hash_32 results = %#x != %#x", - hash_or[0][0], -1u); -#ifdef HAVE_ARCH__HASH_32 -#if HAVE_ARCH__HASH_32 != 1 /* Test is pointless if results match */ - KUNIT_EXPECT_EQ_MSG(test, hash_or[1][0], -1u, - "OR of all __hash_32_generic results = %#x != %#x", - hash_or[1][0], -1u); -#endif -#endif - - /* Likewise for all the i-bit hash values */ - for (i = 1; i <= 32; i++) { - u32 const m = ((u32)2 << (i-1)) - 1; /* Low i bits set */ - - KUNIT_EXPECT_EQ_MSG(test, hash_or[0][i], m, - "OR of all hash_32(%d) results = %#x (%#x expected)", - i, hash_or[0][i], m); - KUNIT_EXPECT_EQ_MSG(test, hash_or[1][i], m, - "OR of all hash_64(%d) results = %#x (%#x expected)", - i, hash_or[1][i], m); - } -} - -static struct kunit_case hash_test_cases[] __refdata = { - KUNIT_CASE(test_string_or), - KUNIT_CASE(test_hash_or), - {} -}; - -static struct kunit_suite hash_test_suite = { - .name = "hash", - .test_cases = hash_test_cases, -}; - - -kunit_test_suite(hash_test_suite); - -MODULE_DESCRIPTION("Test cases for <linux/hash.h> and <linux/stringhash.h>"); -MODULE_LICENSE("GPL"); |