Revision 5e98e916f95bdc50e90f3199d7f3d74b94fa5976 authored by Linus Torvalds on 12 February 2023, 21:52:17 UTC, committed by Linus Torvalds on 12 February 2023, 21:52:17 UTC
Pull tracing fix from Steven Rostedt: "Fix showing of TASK_COMM_LEN instead of its value The TASK_COMM_LEN was converted from a macro into an enum so that BTF would have access to it. But this unfortunately caused TASK_COMM_LEN to display in the format fields of trace events, as they are created by the TRACE_EVENT() macro and such, macros convert to their values, where as enums do not. To handle this, instead of using the field itself to be display, save the value of the array size as another field in the trace_event_fields structure, and use that instead. Not only does this fix the issue, but also converts the other trace events that have this same problem (but were not breaking tooling). With this change, the original work around b3bc8547d3be6 ("tracing: Have TRACE_DEFINE_ENUM affect trace event types as well") could be reverted (but that should be done in the merge window)" * tag 'trace-v6.2-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: tracing: Fix TASK_COMM_LEN in trace event format file
test_hash.c
// 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_LICENSE("GPL");
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