From 034dd340b08be1f2f0477ad16131d609f9dbd53c Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Sun, 30 Aug 2026 09:22:00 -0700 Subject: Merge tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace Pull tracing fixes from Steven Rostedt: - Fix error output of boot instance creation failure Currently if a boot instance creation fails, instead of printing out the name of the instance that failed, it prints "(null)". That is because it prints "cur_str" that had already been processed by strsep(). Print the saved name instead. While at it, print the error code of the failure. - Fix use-after-free for same named historgrams Histograms can be named so that they can be used in multiple events. But if the named histogram has a variable attached, the second event that uses the named histogram which duplicates it and needs to free the original after duplication leaves the old variable in place and still visible. If another histogram uses than variable, it will use the stale one which will try to reference the freed duplicate histogram and crash the kernel. Free the duplicate variables along with the duplicated histogram data. - Check return value of kthread_run() in event self test The events self tests uses a kthread for testing but does not check if it succeeded in creating a kthread. If the kthread creation were to fail, the code will still try to call kthread_stop() on the error returned. - Fix race between reading trace_pipe and updating subbuffer size If a user is reading the trace_pipe file at the same time they update the ring buffer sub-buffer size, can cause the trace_pipe read to read stale data. Add trace_access_lock() around updating the ring buffer sub-buffer size. - Fix eventfs_inode on failure path in creation of the events directory In the creation of the "events" directory, if after allocating the eventfs_inode a failure is detected, it calls cleanup_ei() which calls free_ei(). The free_ei() will test if eventfs_inode being freed has no children. It is a bug if it does. But on the failure case of the creation of the "events" directory, the children lists have not yet been initialized and the free will trigger a warning because list_empty() on an uninitialized list returns false. Move the initialization into init_ei() where it makes more sense and makes sure that a created eventfs_inode has its lists initialized upon creation. - Check return value of kthread_run() in ftrace direct sample code The sample code that shows how to use the ftrace direct calls does not test the return of kthread_run() to see if it succeeds. Return a failure if the kthread_run() doesn't succeed. - Clear user events state on fork in case of alloc failure On fork, the child gets a pointer to the parent's user events state. It makes a copy of it then updates the child's pointer to it. But if the allocation fails, the duplication function leaves the child with a pointer to its parent's descriptor. When the child cleans up its data, it will free the parent's descriptor while the parent is still using it. In the duplication function, set the child's user_event_mm to NULL before testing if the allocation succeeded, and when it exits it will not free the parent's descriptor. - Fix retry exhaustion in simple ring buffer reader swap simple_ring_buffer_swap_reader_page() starts with retry set to 8 and post-decrements it only after a failed link replacement. On the final attempt, a successful replacement leaves retry at zero, while a failed replacement leaves it at -1. But the check for success expects the retry value to be non-zero and exits with an error on zero. This is the opposite result. Fix it. - Fail nicely when the remote swap_reader_page() returns an error Currently, if the swap_reader_page() of a remote buffer fails, it triggers a WARN_ON_ONCE() and continues normally. Instead, have it exit with an error and a pr_warn() print instead of a full WARNING. * tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: ring-buffer: Stop remote reader update when page swap fails tracing: Fix retry exhaustion in simple ring buffer reader swap tracing/user_events: Clear copied tracing state before fork duplication samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-multi-modify samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-modify eventfs: Initialize ei->children and ei->list in init_ei() tracing: Fix use-after-free in trace_pipe read on sub-buffer order change tracing: Fix crash passing ERR_PTR to kthread_stop() tracing: Fix use-after-free with same-name named triggers tracing: Fix logged instance name on creation failure --- lib/tests/string_kunit.c | 924 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 924 insertions(+) create mode 100644 lib/tests/string_kunit.c (limited to 'lib/tests/string_kunit.c') diff --git a/lib/tests/string_kunit.c b/lib/tests/string_kunit.c new file mode 100644 index 000000000..0819ace5b --- /dev/null +++ b/lib/tests/string_kunit.c @@ -0,0 +1,924 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Test cases for string functions. + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#define STRCMP_LARGE_BUF_LEN 2048 +#define STRCMP_CHANGE_POINT 1337 +#define STRCMP_TEST_EXPECT_EQUAL(test, fn, ...) KUNIT_EXPECT_EQ(test, fn(__VA_ARGS__), 0) +#define STRCMP_TEST_EXPECT_LOWER(test, fn, ...) KUNIT_EXPECT_LT(test, fn(__VA_ARGS__), 0) +#define STRCMP_TEST_EXPECT_GREATER(test, fn, ...) KUNIT_EXPECT_GT(test, fn(__VA_ARGS__), 0) + +#define STRING_TEST_MAX_LEN 128 +#define STRING_TEST_MAX_OFFSET 16 + +#define STRING_BENCH_SEED 888 +#define STRING_BENCH_WORKLOAD (1 * MEGA) + +static void string_test_memset16(struct kunit *test) +{ + unsigned i, j, k; + u16 v, *p; + + p = kunit_kzalloc(test, 256 * 2 * 2, GFP_KERNEL); + KUNIT_ASSERT_NOT_ERR_OR_NULL(test, p); + + for (i = 0; i < 256; i++) { + for (j = 0; j < 256; j++) { + memset(p, 0xa1, 256 * 2 * sizeof(v)); + memset16(p + i, 0xb1b2, j); + for (k = 0; k < 512; k++) { + v = p[k]; + if (k < i) { + KUNIT_ASSERT_EQ_MSG(test, v, 0xa1a1, + "i:%d j:%d k:%d", i, j, k); + } else if (k < i + j) { + KUNIT_ASSERT_EQ_MSG(test, v, 0xb1b2, + "i:%d j:%d k:%d", i, j, k); + } else { + KUNIT_ASSERT_EQ_MSG(test, v, 0xa1a1, + "i:%d j:%d k:%d", i, j, k); + } + } + } + } +} + +static void string_test_memset32(struct kunit *test) +{ + unsigned i, j, k; + u32 v, *p; + + p = kunit_kzalloc(test, 256 * 2 * 4, GFP_KERNEL); + KUNIT_ASSERT_NOT_ERR_OR_NULL(test, p); + + for (i = 0; i < 256; i++) { + for (j = 0; j < 256; j++) { + memset(p, 0xa1, 256 * 2 * sizeof(v)); + memset32(p + i, 0xb1b2b3b4, j); + for (k = 0; k < 512; k++) { + v = p[k]; + if (k < i) { + KUNIT_ASSERT_EQ_MSG(test, v, 0xa1a1a1a1, + "i:%d j:%d k:%d", i, j, k); + } else if (k < i + j) { + KUNIT_ASSERT_EQ_MSG(test, v, 0xb1b2b3b4, + "i:%d j:%d k:%d", i, j, k); + } else { + KUNIT_ASSERT_EQ_MSG(test, v, 0xa1a1a1a1, + "i:%d j:%d k:%d", i, j, k); + } + } + } + } +} + +static void string_test_memset64(struct kunit *test) +{ + unsigned i, j, k; + u64 v, *p; + + p = kunit_kzalloc(test, 256 * 2 * 8, GFP_KERNEL); + KUNIT_ASSERT_NOT_ERR_OR_NULL(test, p); + + for (i = 0; i < 256; i++) { + for (j = 0; j < 256; j++) { + memset(p, 0xa1, 256 * 2 * sizeof(v)); + memset64(p + i, 0xb1b2b3b4b5b6b7b8ULL, j); + for (k = 0; k < 512; k++) { + v = p[k]; + if (k < i) { + KUNIT_ASSERT_EQ_MSG(test, v, 0xa1a1a1a1a1a1a1a1ULL, + "i:%d j:%d k:%d", i, j, k); + } else if (k < i + j) { + KUNIT_ASSERT_EQ_MSG(test, v, 0xb1b2b3b4b5b6b7b8ULL, + "i:%d j:%d k:%d", i, j, k); + } else { + KUNIT_ASSERT_EQ_MSG(test, v, 0xa1a1a1a1a1a1a1a1ULL, + "i:%d j:%d k:%d", i, j, k); + } + } + } + } +} + +static void string_test_strlen(struct kunit *test) +{ + size_t buf_size; + char *buf, *s; + + buf_size = PAGE_ALIGN(STRING_TEST_MAX_LEN + STRING_TEST_MAX_OFFSET + 1); + buf = vmalloc(buf_size); + KUNIT_ASSERT_NOT_ERR_OR_NULL(test, buf); + + memset(buf, 'A', buf_size); + + for (size_t offset = 0; offset < STRING_TEST_MAX_OFFSET; offset++) { + for (size_t len = 0; len <= STRING_TEST_MAX_LEN; len++) { + s = buf + buf_size - 1 - offset - len; + s[len] = '\0'; + KUNIT_EXPECT_EQ_MSG(test, strlen(s), len, + "offset:%zu len:%zu", offset, len); + s[len] = 'A'; + } + } + + vfree(buf); +} + +static void string_test_strnlen(struct kunit *test) +{ + size_t buf_size; + char *buf, *s; + + buf_size = PAGE_ALIGN(STRING_TEST_MAX_LEN + STRING_TEST_MAX_OFFSET + 1); + buf = vmalloc(buf_size); + KUNIT_ASSERT_NOT_ERR_OR_NULL(test, buf); + + memset(buf, 'A', buf_size); + + for (size_t offset = 0; offset < STRING_TEST_MAX_OFFSET; offset++) { + for (size_t len = 0; len <= STRING_TEST_MAX_LEN; len++) { + s = buf + buf_size - 1 - offset - len; + s[len] = '\0'; + + if (len > 0) + KUNIT_EXPECT_EQ(test, strnlen(s, len - 1), len - 1); + if (len > 1) + KUNIT_EXPECT_EQ(test, strnlen(s, len - 2), len - 2); + + KUNIT_EXPECT_EQ(test, strnlen(s, len), len); + + KUNIT_EXPECT_EQ(test, strnlen(s, len + 1), len); + KUNIT_EXPECT_EQ(test, strnlen(s, len + 2), len); + KUNIT_EXPECT_EQ(test, strnlen(s, len + 10), len); + + s[len] = 'A'; + } + } + + vfree(buf); +} + +static void string_test_strchr(struct kunit *test) +{ + const char *test_string = "abcdefghijkl"; + const char *empty_string = ""; + char *result; + int i; + + for (i = 0; i < strlen(test_string) + 1; i++) { + result = strchr(test_string, test_string[i]); + KUNIT_ASSERT_EQ_MSG(test, result - test_string, i, + "char:%c", 'a' + i); + } + + result = strchr(empty_string, '\0'); + KUNIT_ASSERT_PTR_EQ(test, result, empty_string); + + result = strchr(empty_string, 'a'); + KUNIT_ASSERT_NULL(test, result); + + result = strchr(test_string, 'z'); + KUNIT_ASSERT_NULL(test, result); +} + +static void string_test_strrchr(struct kunit *test) +{ + size_t buf_size; + char *buf, *s; + + buf_size = PAGE_ALIGN(STRING_TEST_MAX_LEN + STRING_TEST_MAX_OFFSET + 1); + buf = vmalloc(buf_size); + KUNIT_ASSERT_NOT_ERR_OR_NULL(test, buf); + + memset(buf, 'A', buf_size); + + for (size_t offset = 0; offset < STRING_TEST_MAX_OFFSET; offset++) { + for (size_t len = 0; len <= STRING_TEST_MAX_LEN; len++) { + s = buf + buf_size - 1 - offset - len; + s[len] = '\0'; + + KUNIT_EXPECT_PTR_EQ(test, strrchr(s, 'Z'), NULL); + + if (len > 0) + KUNIT_EXPECT_PTR_EQ(test, strrchr(s, 'A'), s + len - 1); + else + KUNIT_EXPECT_PTR_EQ(test, strrchr(s, 'A'), NULL); + + s[len] = 'A'; + } + } + + vfree(buf); +} + +static void string_test_strnchr(struct kunit *test) +{ + const char *test_string = "abcdefghijkl"; + const char *empty_string = ""; + char *result; + int i, j; + + for (i = 0; i < strlen(test_string) + 1; i++) { + for (j = 0; j < strlen(test_string) + 2; j++) { + result = strnchr(test_string, j, test_string[i]); + if (j <= i) { + KUNIT_ASSERT_NULL_MSG(test, result, + "char:%c i:%d j:%d", 'a' + i, i, j); + } else { + KUNIT_ASSERT_EQ_MSG(test, result - test_string, i, + "char:%c i:%d j:%d", 'a' + i, i, j); + } + } + } + + result = strnchr(empty_string, 0, '\0'); + KUNIT_ASSERT_NULL(test, result); + + result = strnchr(empty_string, 1, '\0'); + KUNIT_ASSERT_PTR_EQ(test, result, empty_string); + + result = strnchr(empty_string, 1, 'a'); + KUNIT_ASSERT_NULL(test, result); + + result = strnchr(NULL, 0, '\0'); + KUNIT_ASSERT_NULL(test, result); +} + +static void string_test_strspn(struct kunit *test) +{ + static const struct strspn_test { + const char str[16]; + const char accept[16]; + const char reject[16]; + unsigned a; + unsigned r; + } tests[] = { + { "foobar", "", "", 0, 6 }, + { "abba", "abc", "ABBA", 4, 4 }, + { "abba", "a", "b", 1, 1 }, + { "", "abc", "abc", 0, 0}, + }; + const struct strspn_test *s = tests; + size_t i; + + for (i = 0; i < ARRAY_SIZE(tests); ++i, ++s) { + KUNIT_ASSERT_EQ_MSG(test, s->a, strspn(s->str, s->accept), + "i:%zu", i); + KUNIT_ASSERT_EQ_MSG(test, s->r, strcspn(s->str, s->reject), + "i:%zu", i); + } +} + +static char strcmp_buffer1[STRCMP_LARGE_BUF_LEN]; +static char strcmp_buffer2[STRCMP_LARGE_BUF_LEN]; + +static void strcmp_fill_buffers(char fill1, char fill2) +{ + memset(strcmp_buffer1, fill1, STRCMP_LARGE_BUF_LEN); + memset(strcmp_buffer2, fill2, STRCMP_LARGE_BUF_LEN); + strcmp_buffer1[STRCMP_LARGE_BUF_LEN - 1] = 0; + strcmp_buffer2[STRCMP_LARGE_BUF_LEN - 1] = 0; +} + +static void string_test_strcmp(struct kunit *test) +{ + /* Equal strings */ + STRCMP_TEST_EXPECT_EQUAL(test, strcmp, "Hello, Kernel!", "Hello, Kernel!"); + /* First string is lexicographically less than the second */ + STRCMP_TEST_EXPECT_LOWER(test, strcmp, "Hello, KUnit!", "Hello, Kernel!"); + /* First string is lexicographically larger than the second */ + STRCMP_TEST_EXPECT_GREATER(test, strcmp, "Hello, Kernel!", "Hello, KUnit!"); + /* Empty string is always lexicographically less than any non-empty string */ + STRCMP_TEST_EXPECT_LOWER(test, strcmp, "", "Non-empty string"); + /* Two empty strings should be equal */ + STRCMP_TEST_EXPECT_EQUAL(test, strcmp, "", ""); + /* Compare two strings which have only one char difference */ + STRCMP_TEST_EXPECT_LOWER(test, strcmp, "Abacaba", "Abadaba"); + /* Compare two strings which have the same prefix*/ + STRCMP_TEST_EXPECT_LOWER(test, strcmp, "Just a string", "Just a string and something else"); +} + +static void string_test_strcmp_long_strings(struct kunit *test) +{ + strcmp_fill_buffers('B', 'B'); + STRCMP_TEST_EXPECT_EQUAL(test, strcmp, strcmp_buffer1, strcmp_buffer2); + + strcmp_buffer1[STRCMP_CHANGE_POINT] = 'A'; + STRCMP_TEST_EXPECT_LOWER(test, strcmp, strcmp_buffer1, strcmp_buffer2); + + strcmp_buffer1[STRCMP_CHANGE_POINT] = 'C'; + STRCMP_TEST_EXPECT_GREATER(test, strcmp, strcmp_buffer1, strcmp_buffer2); +} + +static void string_test_strncmp(struct kunit *test) +{ + /* Equal strings */ + STRCMP_TEST_EXPECT_EQUAL(test, strncmp, "Hello, KUnit!", "Hello, KUnit!", 13); + /* First string is lexicographically less than the second */ + STRCMP_TEST_EXPECT_LOWER(test, strncmp, "Hello, KUnit!", "Hello, Kernel!", 13); + /* Result is always 'equal' when count = 0 */ + STRCMP_TEST_EXPECT_EQUAL(test, strncmp, "Hello, Kernel!", "Hello, KUnit!", 0); + /* Strings with common prefix are equal if count = length of prefix */ + STRCMP_TEST_EXPECT_EQUAL(test, strncmp, "Abacaba", "Abadaba", 3); + /* Strings with common prefix are not equal when count = length of prefix + 1 */ + STRCMP_TEST_EXPECT_LOWER(test, strncmp, "Abacaba", "Abadaba", 4); + /* If one string is a prefix of another, the shorter string is lexicographically smaller */ + STRCMP_TEST_EXPECT_LOWER(test, strncmp, "Just a string", "Just a string and something else", + strlen("Just a string and something else")); + /* + * If one string is a prefix of another, and we check first length + * of prefix chars, the result is 'equal' + */ + STRCMP_TEST_EXPECT_EQUAL(test, strncmp, "Just a string", "Just a string and something else", + strlen("Just a string")); +} + +static void string_test_strncmp_long_strings(struct kunit *test) +{ + strcmp_fill_buffers('B', 'B'); + STRCMP_TEST_EXPECT_EQUAL(test, strncmp, strcmp_buffer1, + strcmp_buffer2, STRCMP_LARGE_BUF_LEN); + + strcmp_buffer1[STRCMP_CHANGE_POINT] = 'A'; + STRCMP_TEST_EXPECT_LOWER(test, strncmp, strcmp_buffer1, + strcmp_buffer2, STRCMP_LARGE_BUF_LEN); + + strcmp_buffer1[STRCMP_CHANGE_POINT] = 'C'; + STRCMP_TEST_EXPECT_GREATER(test, strncmp, strcmp_buffer1, + strcmp_buffer2, STRCMP_LARGE_BUF_LEN); + /* the strings are equal up to STRCMP_CHANGE_POINT */ + STRCMP_TEST_EXPECT_EQUAL(test, strncmp, strcmp_buffer1, + strcmp_buffer2, STRCMP_CHANGE_POINT); + STRCMP_TEST_EXPECT_GREATER(test, strncmp, strcmp_buffer1, + strcmp_buffer2, STRCMP_CHANGE_POINT + 1); +} + +static void string_test_strcasecmp(struct kunit *test) +{ + /* Same strings in different case should be equal */ + STRCMP_TEST_EXPECT_EQUAL(test, strcasecmp, "Hello, Kernel!", "HeLLO, KErNeL!"); + /* Empty strings should be equal */ + STRCMP_TEST_EXPECT_EQUAL(test, strcasecmp, "", ""); + /* Despite ascii code for 'a' is larger than ascii code for 'B', 'a' < 'B' */ + STRCMP_TEST_EXPECT_LOWER(test, strcasecmp, "a", "B"); + STRCMP_TEST_EXPECT_GREATER(test, strcasecmp, "B", "a"); + /* Special symbols and numbers should be processed correctly */ + STRCMP_TEST_EXPECT_EQUAL(test, strcasecmp, "-+**.1230ghTTT~^", "-+**.1230Ghttt~^"); +} + +static void string_test_strcasecmp_long_strings(struct kunit *test) +{ + strcmp_fill_buffers('b', 'B'); + STRCMP_TEST_EXPECT_EQUAL(test, strcasecmp, strcmp_buffer1, strcmp_buffer2); + + strcmp_buffer1[STRCMP_CHANGE_POINT] = 'a'; + STRCMP_TEST_EXPECT_LOWER(test, strcasecmp, strcmp_buffer1, strcmp_buffer2); + + strcmp_buffer1[STRCMP_CHANGE_POINT] = 'C'; + STRCMP_TEST_EXPECT_GREATER(test, strcasecmp, strcmp_buffer1, strcmp_buffer2); +} + +static void string_test_strncasecmp(struct kunit *test) +{ + /* Same strings in different case should be equal */ + STRCMP_TEST_EXPECT_EQUAL(test, strncasecmp, "AbAcAbA", "Abacaba", strlen("Abacaba")); + /* strncasecmp should check 'count' chars only */ + STRCMP_TEST_EXPECT_EQUAL(test, strncasecmp, "AbaCaBa", "abaCaDa", 5); + STRCMP_TEST_EXPECT_LOWER(test, strncasecmp, "a", "B", 1); + STRCMP_TEST_EXPECT_GREATER(test, strncasecmp, "B", "a", 1); + /* Result is always 'equal' when count = 0 */ + STRCMP_TEST_EXPECT_EQUAL(test, strncasecmp, "Abacaba", "Not abacaba", 0); +} + +static void string_test_strncasecmp_long_strings(struct kunit *test) +{ + strcmp_fill_buffers('b', 'B'); + STRCMP_TEST_EXPECT_EQUAL(test, strncasecmp, strcmp_buffer1, + strcmp_buffer2, STRCMP_LARGE_BUF_LEN); + + strcmp_buffer1[STRCMP_CHANGE_POINT] = 'a'; + STRCMP_TEST_EXPECT_LOWER(test, strncasecmp, strcmp_buffer1, + strcmp_buffer2, STRCMP_LARGE_BUF_LEN); + + strcmp_buffer1[STRCMP_CHANGE_POINT] = 'C'; + STRCMP_TEST_EXPECT_GREATER(test, strncasecmp, strcmp_buffer1, + strcmp_buffer2, STRCMP_LARGE_BUF_LEN); + + STRCMP_TEST_EXPECT_EQUAL(test, strncasecmp, strcmp_buffer1, + strcmp_buffer2, STRCMP_CHANGE_POINT); + STRCMP_TEST_EXPECT_GREATER(test, strncasecmp, strcmp_buffer1, + strcmp_buffer2, STRCMP_CHANGE_POINT + 1); +} + +/** + * strscpy_check() - Run a specific test case. + * @test: KUnit test context pointer + * @src: Source string, argument to strscpy_pad() + * @count: Size of destination buffer, argument to strscpy_pad() + * @expected: Expected return value from call to strscpy_pad() + * @chars: Number of characters from the src string expected to be + * written to the dst buffer. + * @terminator: 1 if there should be a terminating null byte 0 otherwise. + * @pad: Number of pad characters expected (in the tail of dst buffer). + * (@pad does not include the null terminator byte.) + * + * Calls strscpy_pad() and verifies the return value and state of the + * destination buffer after the call returns. + */ +static void strscpy_check(struct kunit *test, char *src, int count, + int expected, int chars, int terminator, int pad) +{ + int nr_bytes_poison; + int max_expected; + int max_count; + int written; + char buf[6]; + int index, i; + const char POISON = 'z'; + + KUNIT_ASSERT_TRUE_MSG(test, src != NULL, + "null source string not supported"); + + memset(buf, POISON, sizeof(buf)); + /* Future proofing test suite, validate args */ + max_count = sizeof(buf) - 2; /* Space for null and to verify overflow */ + max_expected = count - 1; /* Space for the null */ + + KUNIT_ASSERT_LE_MSG(test, count, max_count, + "count (%d) is too big (%d) ... aborting", count, max_count); + KUNIT_EXPECT_LE_MSG(test, expected, max_expected, + "expected (%d) is bigger than can possibly be returned (%d)", + expected, max_expected); + + written = strscpy_pad(buf, src, count); + KUNIT_ASSERT_EQ(test, written, expected); + + if (count && written == -E2BIG) { + KUNIT_ASSERT_EQ_MSG(test, 0, strncmp(buf, src, count - 1), + "buffer state invalid for -E2BIG"); + KUNIT_ASSERT_EQ_MSG(test, buf[count - 1], '\0', + "too big string is not null terminated correctly"); + } + + for (i = 0; i < chars; i++) + KUNIT_ASSERT_EQ_MSG(test, buf[i], src[i], + "buf[i]==%c != src[i]==%c", buf[i], src[i]); + + if (terminator) + KUNIT_ASSERT_EQ_MSG(test, buf[count - 1], '\0', + "string is not null terminated correctly"); + + for (i = 0; i < pad; i++) { + index = chars + terminator + i; + KUNIT_ASSERT_EQ_MSG(test, buf[index], '\0', + "padding missing at index: %d", i); + } + + nr_bytes_poison = sizeof(buf) - chars - terminator - pad; + for (i = 0; i < nr_bytes_poison; i++) { + index = sizeof(buf) - 1 - i; /* Check from the end back */ + KUNIT_ASSERT_EQ_MSG(test, buf[index], POISON, + "poison value missing at index: %d", i); + } +} + +static void string_test_strscpy(struct kunit *test) +{ + char dest[8]; + + /* + * strscpy_check() uses a destination buffer of size 6 and needs at + * least 2 characters spare (one for null and one to check for + * overflow). This means we should only call tc() with + * strings up to a maximum of 4 characters long and 'count' + * should not exceed 4. To test with longer strings increase + * the buffer size in tc(). + */ + + /* strscpy_check(test, src, count, expected, chars, terminator, pad) */ + strscpy_check(test, "a", 0, -E2BIG, 0, 0, 0); + strscpy_check(test, "", 0, -E2BIG, 0, 0, 0); + + strscpy_check(test, "a", 1, -E2BIG, 0, 1, 0); + strscpy_check(test, "", 1, 0, 0, 1, 0); + + strscpy_check(test, "ab", 2, -E2BIG, 1, 1, 0); + strscpy_check(test, "a", 2, 1, 1, 1, 0); + strscpy_check(test, "", 2, 0, 0, 1, 1); + + strscpy_check(test, "abc", 3, -E2BIG, 2, 1, 0); + strscpy_check(test, "ab", 3, 2, 2, 1, 0); + strscpy_check(test, "a", 3, 1, 1, 1, 1); + strscpy_check(test, "", 3, 0, 0, 1, 2); + + strscpy_check(test, "abcd", 4, -E2BIG, 3, 1, 0); + strscpy_check(test, "abc", 4, 3, 3, 1, 0); + strscpy_check(test, "ab", 4, 2, 2, 1, 1); + strscpy_check(test, "a", 4, 1, 1, 1, 2); + strscpy_check(test, "", 4, 0, 0, 1, 3); + + /* Compile-time-known source strings. */ + KUNIT_EXPECT_EQ(test, strscpy(dest, "", ARRAY_SIZE(dest)), 0); + KUNIT_EXPECT_EQ(test, strscpy(dest, "", 3), 0); + KUNIT_EXPECT_EQ(test, strscpy(dest, "", 1), 0); + KUNIT_EXPECT_EQ(test, strscpy(dest, "", 0), -E2BIG); + KUNIT_EXPECT_EQ(test, strscpy(dest, "Fixed", ARRAY_SIZE(dest)), 5); + KUNIT_EXPECT_EQ(test, strscpy(dest, "Fixed", 3), -E2BIG); + KUNIT_EXPECT_EQ(test, strscpy(dest, "Fixed", 1), -E2BIG); + KUNIT_EXPECT_EQ(test, strscpy(dest, "Fixed", 0), -E2BIG); + KUNIT_EXPECT_EQ(test, strscpy(dest, "This is too long", ARRAY_SIZE(dest)), -E2BIG); +} + +static volatile int unconst; + +static void string_test_strcat(struct kunit *test) +{ + char dest[8]; + + /* Destination is terminated. */ + memset(dest, 0, sizeof(dest)); + KUNIT_EXPECT_EQ(test, strlen(dest), 0); + /* Empty copy does nothing. */ + KUNIT_EXPECT_TRUE(test, strcat(dest, "") == dest); + KUNIT_EXPECT_STREQ(test, dest, ""); + /* 4 characters copied in, stops at %NUL. */ + KUNIT_EXPECT_TRUE(test, strcat(dest, "four\000123") == dest); + KUNIT_EXPECT_STREQ(test, dest, "four"); + KUNIT_EXPECT_EQ(test, dest[5], '\0'); + /* 2 more characters copied in okay. */ + KUNIT_EXPECT_TRUE(test, strcat(dest, "AB") == dest); + KUNIT_EXPECT_STREQ(test, dest, "fourAB"); +} + +static void string_test_strncat(struct kunit *test) +{ + char dest[8]; + + /* Destination is terminated. */ + memset(dest, 0, sizeof(dest)); + KUNIT_EXPECT_EQ(test, strlen(dest), 0); + /* Empty copy of size 0 does nothing. */ + KUNIT_EXPECT_TRUE(test, strncat(dest, "", 0 + unconst) == dest); + KUNIT_EXPECT_STREQ(test, dest, ""); + /* Empty copy of size 1 does nothing too. */ + KUNIT_EXPECT_TRUE(test, strncat(dest, "", 1 + unconst) == dest); + KUNIT_EXPECT_STREQ(test, dest, ""); + /* Copy of max 0 characters should do nothing. */ + KUNIT_EXPECT_TRUE(test, strncat(dest, "asdf", 0 + unconst) == dest); + KUNIT_EXPECT_STREQ(test, dest, ""); + + /* 4 characters copied in, even if max is 8. */ + KUNIT_EXPECT_TRUE(test, strncat(dest, "four\000123", 8 + unconst) == dest); + KUNIT_EXPECT_STREQ(test, dest, "four"); + KUNIT_EXPECT_EQ(test, dest[5], '\0'); + KUNIT_EXPECT_EQ(test, dest[6], '\0'); + /* 2 characters copied in okay, 2 ignored. */ + KUNIT_EXPECT_TRUE(test, strncat(dest, "ABCD", 2 + unconst) == dest); + KUNIT_EXPECT_STREQ(test, dest, "fourAB"); +} + +static void string_test_strlcat(struct kunit *test) +{ + char dest[8] = ""; + int len = sizeof(dest) + unconst; + + /* Destination is terminated. */ + KUNIT_EXPECT_EQ(test, strlen(dest), 0); + /* Empty copy is size 0. */ + KUNIT_EXPECT_EQ(test, strlcat(dest, "", len), 0); + KUNIT_EXPECT_STREQ(test, dest, ""); + /* Size 1 should keep buffer terminated, report size of source only. */ + KUNIT_EXPECT_EQ(test, strlcat(dest, "four", 1 + unconst), 4); + KUNIT_EXPECT_STREQ(test, dest, ""); + + /* 4 characters copied in. */ + KUNIT_EXPECT_EQ(test, strlcat(dest, "four", len), 4); + KUNIT_EXPECT_STREQ(test, dest, "four"); + /* 2 characters copied in okay, gets to 6 total. */ + KUNIT_EXPECT_EQ(test, strlcat(dest, "AB", len), 6); + KUNIT_EXPECT_STREQ(test, dest, "fourAB"); + /* 2 characters ignored if max size (7) reached. */ + KUNIT_EXPECT_EQ(test, strlcat(dest, "CD", 7 + unconst), 8); + KUNIT_EXPECT_STREQ(test, dest, "fourAB"); + /* 1 of 2 characters skipped, now at true max size. */ + KUNIT_EXPECT_EQ(test, strlcat(dest, "EFG", len), 9); + KUNIT_EXPECT_STREQ(test, dest, "fourABE"); + /* Everything else ignored, now at full size. */ + KUNIT_EXPECT_EQ(test, strlcat(dest, "1234", len), 11); + KUNIT_EXPECT_STREQ(test, dest, "fourABE"); +} + +static void string_test_strtomem(struct kunit *test) +{ + static const char input[sizeof(unsigned long)] = "hi"; + static const char truncate[] = "this is too long"; + struct { + unsigned long canary1; + unsigned char output[sizeof(unsigned long)] __nonstring; + unsigned long canary2; + } wrap; + + memset(&wrap, 0xFF, sizeof(wrap)); + KUNIT_EXPECT_EQ_MSG(test, wrap.canary1, ULONG_MAX, + "bad initial canary value"); + KUNIT_EXPECT_EQ_MSG(test, wrap.canary2, ULONG_MAX, + "bad initial canary value"); + + /* Check unpadded copy leaves surroundings untouched. */ + strtomem(wrap.output, input); + KUNIT_EXPECT_EQ(test, wrap.canary1, ULONG_MAX); + KUNIT_EXPECT_EQ(test, wrap.output[0], input[0]); + KUNIT_EXPECT_EQ(test, wrap.output[1], input[1]); + for (size_t i = 2; i < sizeof(wrap.output); i++) + KUNIT_EXPECT_EQ(test, wrap.output[i], 0xFF); + KUNIT_EXPECT_EQ(test, wrap.canary2, ULONG_MAX); + + /* Check truncated copy leaves surroundings untouched. */ + memset(&wrap, 0xFF, sizeof(wrap)); + strtomem(wrap.output, truncate); + KUNIT_EXPECT_EQ(test, wrap.canary1, ULONG_MAX); + for (size_t i = 0; i < sizeof(wrap.output); i++) + KUNIT_EXPECT_EQ(test, wrap.output[i], truncate[i]); + KUNIT_EXPECT_EQ(test, wrap.canary2, ULONG_MAX); + + /* Check padded copy leaves only string padded. */ + memset(&wrap, 0xFF, sizeof(wrap)); + strtomem_pad(wrap.output, input, 0xAA); + KUNIT_EXPECT_EQ(test, wrap.canary1, ULONG_MAX); + KUNIT_EXPECT_EQ(test, wrap.output[0], input[0]); + KUNIT_EXPECT_EQ(test, wrap.output[1], input[1]); + for (size_t i = 2; i < sizeof(wrap.output); i++) + KUNIT_EXPECT_EQ(test, wrap.output[i], 0xAA); + KUNIT_EXPECT_EQ(test, wrap.canary2, ULONG_MAX); + + /* Check truncated padded copy has no padding. */ + memset(&wrap, 0xFF, sizeof(wrap)); + strtomem(wrap.output, truncate); + KUNIT_EXPECT_EQ(test, wrap.canary1, ULONG_MAX); + for (size_t i = 0; i < sizeof(wrap.output); i++) + KUNIT_EXPECT_EQ(test, wrap.output[i], truncate[i]); + KUNIT_EXPECT_EQ(test, wrap.canary2, ULONG_MAX); +} + + +static void string_test_memtostr(struct kunit *test) +{ + char nonstring[7] __nonstring = { 'a', 'b', 'c', 'd', 'e', 'f', 'g' }; + char nonstring_small[3] __nonstring = { 'a', 'b', 'c' }; + char dest[sizeof(nonstring) + 1]; + + /* Copy in a non-NUL-terminated string into exactly right-sized dest. */ + KUNIT_EXPECT_EQ(test, sizeof(dest), sizeof(nonstring) + 1); + memset(dest, 'X', sizeof(dest)); + memtostr(dest, nonstring); + KUNIT_EXPECT_STREQ(test, dest, "abcdefg"); + memset(dest, 'X', sizeof(dest)); + memtostr(dest, nonstring_small); + KUNIT_EXPECT_STREQ(test, dest, "abc"); + KUNIT_EXPECT_EQ(test, dest[7], 'X'); + + memset(dest, 'X', sizeof(dest)); + memtostr_pad(dest, nonstring); + KUNIT_EXPECT_STREQ(test, dest, "abcdefg"); + memset(dest, 'X', sizeof(dest)); + memtostr_pad(dest, nonstring_small); + KUNIT_EXPECT_STREQ(test, dest, "abc"); + KUNIT_EXPECT_EQ(test, dest[7], '\0'); +} + +static void string_test_strends(struct kunit *test) +{ + KUNIT_EXPECT_TRUE(test, strends("foo-bar", "bar")); + KUNIT_EXPECT_TRUE(test, strends("foo-bar", "-bar")); + KUNIT_EXPECT_TRUE(test, strends("foobar", "foobar")); + KUNIT_EXPECT_TRUE(test, strends("foobar", "")); + KUNIT_EXPECT_FALSE(test, strends("bar", "foobar")); + KUNIT_EXPECT_FALSE(test, strends("", "foo")); + KUNIT_EXPECT_FALSE(test, strends("foobar", "ba")); + KUNIT_EXPECT_TRUE(test, strends("", "")); +} + +#if IS_ENABLED(CONFIG_STRING_KUNIT_BENCH) +/* Target string lengths for benchmarking */ +static const size_t bench_lens[] = { + 0, 1, 7, 8, 16, 31, 64, 127, 512, 1024, 3173, 4096, +}; + +/** + * alloc_max_bench_buffer() - Allocate buffer for the max test case. + * @test: KUnit context for managed allocation. + * @lens: Array of lengths used in the benchmark cases. + * @count: Number of elements in the @lens array. + * @buf_len: [out] Pointer to store the actually allocated buffer + * size (including NUL character). + * + * Return: Pointer to the allocated memory, or NULL on failure. + */ +static void *alloc_max_bench_buffer(struct kunit *test, const size_t *lens, + size_t count, size_t *buf_len) +{ + size_t max_len = 0; + void *buf; + + for (size_t i = 0; i < count; i++) + max_len = max(lens[i], max_len); + + /* Add space for NUL character */ + max_len += 1; + + buf = kunit_kzalloc(test, max_len, GFP_KERNEL); + if (!buf) + return NULL; + + if (buf_len) + *buf_len = max_len; + + return buf; +} + +/** + * fill_random_string() - Populate a buffer with a random NUL-terminated string. + * @buf: Buffer to fill. + * @len: Length of the buffer in bytes. + * + * Fills the buffer with random non-NUL bytes and ensures the string is + * properly NUL-terminated. + */ +static void fill_random_string(char *buf, size_t len) +{ + struct rnd_state state; + + if (!buf || !len) + return; + + /* Use a fixed seed to ensure deterministic benchmark results */ + prandom_seed_state(&state, STRING_BENCH_SEED); + prandom_bytes_state(&state, buf, len); + + /* Replace NUL characters to avoid early string termination */ + for (size_t i = 0; i < len; i++) { + if (buf[i] == '\0') + buf[i] = 0x01; + } + + buf[len - 1] = '\0'; +} + +/** + * STRING_BENCH() - Benchmark string functions. + * @iters: Number of iterations to run. + * @func: Function to benchmark. + * @...: Variable arguments passed to @func. + * + * Disables preemption and measures the total time in nanoseconds to execute + * @func(@__VA_ARGS__) for @iters times, including a small warm-up phase. + * + * Context: Disables preemption during measurement. + * Return: Total execution time in nanoseconds (u64). + */ +#define STRING_BENCH(iters, func, ...) \ +({ \ + /* Volatile function pointer prevents dead code elimination */ \ + typeof(func) (* volatile __func) = (func); \ + size_t __bn_iters = (iters); \ + size_t __bn_warm_iters; \ + u64 __bn_t; \ + \ + /* Use 10% of the given iterations (maximum 50) to warm up */ \ + __bn_warm_iters = max(__bn_iters / 10, 50U); \ + \ + for (size_t __bn_i = 0; __bn_i < __bn_warm_iters; __bn_i++) \ + (void)__func(__VA_ARGS__); \ + \ + preempt_disable(); \ + __bn_t = ktime_get_ns(); \ + for (size_t __bn_i = 0; __bn_i < __bn_iters; __bn_i++) \ + (void)__func(__VA_ARGS__); \ + __bn_t = ktime_get_ns() - __bn_t; \ + preempt_enable(); \ + __bn_t; \ +}) + +/** + * STRING_BENCH_BUF() - Benchmark harness for single-buffer functions. + * @test: KUnit context. + * @buf_name: Local char * variable name to be defined. + * @buf_size: Local size_t variable name to be defined. + * @func: Function to benchmark. + * @...: Extra arguments for @func. + * + * Prepares a randomized, NUL-terminated buffer and iterates through lengths + * in bench_lens, defining @buf_name and @buf_size in each loop. + */ +#define STRING_BENCH_BUF(test, buf_name, buf_size, func, ...) \ +do { \ + size_t _bn_i, _bn_iters, _bn_size = 0; \ + u64 _bn_t, _bn_mbps = 0, _bn_lat = 0; \ + char *_bn_buf; \ + \ + _bn_buf = alloc_max_bench_buffer(test, bench_lens, \ + ARRAY_SIZE(bench_lens), &_bn_size); \ + KUNIT_ASSERT_NOT_ERR_OR_NULL(test, _bn_buf); \ + \ + fill_random_string(_bn_buf, _bn_size); \ + \ + for (_bn_i = 0; _bn_i < ARRAY_SIZE(bench_lens); _bn_i++) { \ + size_t buf_size = bench_lens[_bn_i]; \ + char *buf_name = _bn_buf + _bn_size - buf_size - 1; \ + _bn_iters = STRING_BENCH_WORKLOAD / max(buf_size, 1U); \ + \ + _bn_t = STRING_BENCH(_bn_iters, func, ##__VA_ARGS__); \ + if (_bn_t > 0) { \ + _bn_mbps = (u64)(buf_size) * _bn_iters * \ + (NSEC_PER_SEC / MEGA); \ + _bn_mbps = div64_u64(_bn_mbps, _bn_t); \ + _bn_lat = div64_u64(_bn_t, _bn_iters); \ + } \ + kunit_info(test, "len=%zu: %llu MB/s (%llu ns/call)\n", \ + buf_size, _bn_mbps, _bn_lat); \ + } \ +} while (0) +#else +#define STRING_BENCH_BUF(test, buf_name, buf_size, func, ...) \ + kunit_skip(test, "not enabled") +#endif /* IS_ENABLED(CONFIG_STRING_KUNIT_BENCH) */ + +static void string_bench_strlen(struct kunit *test) +{ + STRING_BENCH_BUF(test, buf, len, strlen, buf); +} + +static void string_bench_strnlen(struct kunit *test) +{ + STRING_BENCH_BUF(test, buf, len, strnlen, buf, len); +} + +static void string_bench_strchr(struct kunit *test) +{ + STRING_BENCH_BUF(test, buf, len, strchr, buf, '\0'); +} + +static void string_bench_strrchr(struct kunit *test) +{ + STRING_BENCH_BUF(test, buf, len, strrchr, buf, '\0'); +} + +static struct kunit_case string_test_cases[] = { + KUNIT_CASE(string_test_memset16), + KUNIT_CASE(string_test_memset32), + KUNIT_CASE(string_test_memset64), + KUNIT_CASE(string_test_strlen), + KUNIT_CASE(string_test_strnlen), + KUNIT_CASE(string_test_strchr), + KUNIT_CASE(string_test_strnchr), + KUNIT_CASE(string_test_strrchr), + KUNIT_CASE(string_test_strspn), + KUNIT_CASE(string_test_strcmp), + KUNIT_CASE(string_test_strcmp_long_strings), + KUNIT_CASE(string_test_strncmp), + KUNIT_CASE(string_test_strncmp_long_strings), + KUNIT_CASE(string_test_strcasecmp), + KUNIT_CASE(string_test_strcasecmp_long_strings), + KUNIT_CASE(string_test_strncasecmp), + KUNIT_CASE(string_test_strncasecmp_long_strings), + KUNIT_CASE(string_test_strscpy), + KUNIT_CASE(string_test_strcat), + KUNIT_CASE(string_test_strncat), + KUNIT_CASE(string_test_strlcat), + KUNIT_CASE(string_test_strtomem), + KUNIT_CASE(string_test_memtostr), + KUNIT_CASE(string_test_strends), + KUNIT_CASE(string_bench_strlen), + KUNIT_CASE(string_bench_strnlen), + KUNIT_CASE(string_bench_strchr), + KUNIT_CASE(string_bench_strrchr), + {} +}; + +static struct kunit_suite string_test_suite = { + .name = "string", + .test_cases = string_test_cases, +}; + +kunit_test_suites(&string_test_suite); + +MODULE_DESCRIPTION("Test cases for string functions"); +MODULE_LICENSE("GPL v2"); -- cgit v1.3.1