1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Kernel module for testing 'strcat' family of functions. 4 */ 5 6 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 7 8 #include <kunit/test.h> 9 #include <linux/string.h> 10 11 static volatile int unconst; 12 13 static void strcat_test(struct kunit *test) 14 { 15 char dest[8]; 16 17 /* Destination is terminated. */ 18 memset(dest, 0, sizeof(dest)); 19 KUNIT_EXPECT_EQ(test, strlen(dest), 0); 20 /* Empty copy does nothing. */ 21 KUNIT_EXPECT_TRUE(test, strcat(dest, "") == dest); 22 KUNIT_EXPECT_STREQ(test, dest, ""); 23 /* 4 characters copied in, stops at %NUL. */ 24 KUNIT_EXPECT_TRUE(test, strcat(dest, "four\000123") == dest); 25 KUNIT_EXPECT_STREQ(test, dest, "four"); 26 KUNIT_EXPECT_EQ(test, dest[5], '\0'); 27 /* 2 more characters copied in okay. */ 28 KUNIT_EXPECT_TRUE(test, strcat(dest, "AB") == dest); 29 KUNIT_EXPECT_STREQ(test, dest, "fourAB"); 30 } 31 32 static void strncat_test(struct kunit *test) 33 { 34 char dest[8]; 35 36 /* Destination is terminated. */ 37 memset(dest, 0, sizeof(dest)); 38 KUNIT_EXPECT_EQ(test, strlen(dest), 0); 39 /* Empty copy of size 0 does nothing. */ 40 KUNIT_EXPECT_TRUE(test, strncat(dest, "", 0 + unconst) == dest); 41 KUNIT_EXPECT_STREQ(test, dest, ""); 42 /* Empty copy of size 1 does nothing too. */ 43 KUNIT_EXPECT_TRUE(test, strncat(dest, "", 1 + unconst) == dest); 44 KUNIT_EXPECT_STREQ(test, dest, ""); 45 /* Copy of max 0 characters should do nothing. */ 46 KUNIT_EXPECT_TRUE(test, strncat(dest, "asdf", 0 + unconst) == dest); 47 KUNIT_EXPECT_STREQ(test, dest, ""); 48 49 /* 4 characters copied in, even if max is 8. */ 50 KUNIT_EXPECT_TRUE(test, strncat(dest, "four\000123", 8 + unconst) == dest); 51 KUNIT_EXPECT_STREQ(test, dest, "four"); 52 KUNIT_EXPECT_EQ(test, dest[5], '\0'); 53 KUNIT_EXPECT_EQ(test, dest[6], '\0'); 54 /* 2 characters copied in okay, 2 ignored. */ 55 KUNIT_EXPECT_TRUE(test, strncat(dest, "ABCD", 2 + unconst) == dest); 56 KUNIT_EXPECT_STREQ(test, dest, "fourAB"); 57 } 58 59 static void strlcat_test(struct kunit *test) 60 { 61 char dest[8] = ""; 62 int len = sizeof(dest) + unconst; 63 64 /* Destination is terminated. */ 65 KUNIT_EXPECT_EQ(test, strlen(dest), 0); 66 /* Empty copy is size 0. */ 67 KUNIT_EXPECT_EQ(test, strlcat(dest, "", len), 0); 68 KUNIT_EXPECT_STREQ(test, dest, ""); 69 /* Size 1 should keep buffer terminated, report size of source only. */ 70 KUNIT_EXPECT_EQ(test, strlcat(dest, "four", 1 + unconst), 4); 71 KUNIT_EXPECT_STREQ(test, dest, ""); 72 73 /* 4 characters copied in. */ 74 KUNIT_EXPECT_EQ(test, strlcat(dest, "four", len), 4); 75 KUNIT_EXPECT_STREQ(test, dest, "four"); 76 /* 2 characters copied in okay, gets to 6 total. */ 77 KUNIT_EXPECT_EQ(test, strlcat(dest, "AB", len), 6); 78 KUNIT_EXPECT_STREQ(test, dest, "fourAB"); 79 /* 2 characters ignored if max size (7) reached. */ 80 KUNIT_EXPECT_EQ(test, strlcat(dest, "CD", 7 + unconst), 8); 81 KUNIT_EXPECT_STREQ(test, dest, "fourAB"); 82 /* 1 of 2 characters skipped, now at true max size. */ 83 KUNIT_EXPECT_EQ(test, strlcat(dest, "EFG", len), 9); 84 KUNIT_EXPECT_STREQ(test, dest, "fourABE"); 85 /* Everything else ignored, now at full size. */ 86 KUNIT_EXPECT_EQ(test, strlcat(dest, "1234", len), 11); 87 KUNIT_EXPECT_STREQ(test, dest, "fourABE"); 88 } 89 90 static struct kunit_case strcat_test_cases[] = { 91 KUNIT_CASE(strcat_test), 92 KUNIT_CASE(strncat_test), 93 KUNIT_CASE(strlcat_test), 94 {} 95 }; 96 97 static struct kunit_suite strcat_test_suite = { 98 .name = "strcat", 99 .test_cases = strcat_test_cases, 100 }; 101 102 kunit_test_suite(strcat_test_suite); 103 104 MODULE_LICENSE("GPL"); 105