Adding upstream version 6.1.76.upstream/6.1.76

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 238 insertions, 0 deletions

diff --git a/lib/test_hash.c b/lib/test_hash.c
new file mode 100644
index 000000000..bb25fda34
--- /dev/null
+++ b/lib/test_hash.c
@@ -0,0 +1,238 @@
+// 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, &params);
+#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, &params, &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_LICENSE("GPL");