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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 | // SPDX-License-Identifier: GPL-2.0+ /* * Kernel module for testing 'strscpy' family of functions. */ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt #include <kunit/test.h> #include <linux/string.h> /* * tc() - Run a specific test case. * @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() * @terminator: 1 if there should be a terminating null byte 0 otherwise. * @chars: Number of characters from the src string expected to be * written to the dst buffer. * @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 tc(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 strscpy_test(struct kunit *test) { char dest[8]; /* * tc() 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(). */ /* tc(test, src, count, expected, chars, terminator, pad) */ tc(test, "a", 0, -E2BIG, 0, 0, 0); tc(test, "", 0, -E2BIG, 0, 0, 0); tc(test, "a", 1, -E2BIG, 0, 1, 0); tc(test, "", 1, 0, 0, 1, 0); tc(test, "ab", 2, -E2BIG, 1, 1, 0); tc(test, "a", 2, 1, 1, 1, 0); tc(test, "", 2, 0, 0, 1, 1); tc(test, "abc", 3, -E2BIG, 2, 1, 0); tc(test, "ab", 3, 2, 2, 1, 0); tc(test, "a", 3, 1, 1, 1, 1); tc(test, "", 3, 0, 0, 1, 2); tc(test, "abcd", 4, -E2BIG, 3, 1, 0); tc(test, "abc", 4, 3, 3, 1, 0); tc(test, "ab", 4, 2, 2, 1, 1); tc(test, "a", 4, 1, 1, 1, 2); tc(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 struct kunit_case strscpy_test_cases[] = { KUNIT_CASE(strscpy_test), {} }; static struct kunit_suite strscpy_test_suite = { .name = "strscpy", .test_cases = strscpy_test_cases, }; kunit_test_suite(strscpy_test_suite); MODULE_AUTHOR("Tobin C. Harding <tobin@kernel.org>"); MODULE_LICENSE("GPL"); |