| 1 | |
| 2 | |
| 3 | * arch/arm/boot/compressed/string.c
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| 4 | *
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| 5 | * Small subset of simple string routines
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| 6 |
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| 7 |
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| 8 | #define __NO_FORTIFY
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| 9 | #include <linux/string.h>
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| 10 |
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| 11 | |
| 12 | * The decompressor is built without KASan but uses the same redirects as the
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| 13 | * rest of the kernel when CONFIG_KASAN is enabled, defining e.g. memcpy()
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| 14 | * to __memcpy() but since we are not linking with the main kernel string
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| 15 | * library in the decompressor, that will lead to link failures.
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| 16 | *
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| 17 | * Undefine KASan's versions, define the wrapped functions and alias them to
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| 18 | * the right names so that when e.g. __memcpy() appear in the code, it will
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| 19 | * still be linked to this local version of memcpy().
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| 20 |
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| 21 | #ifdef CONFIG_KASAN
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| 22 | #undef memcpy
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| 23 | #undef memmove
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| 24 | #undef memset
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| 25 | void *__memcpy(void *__dest, __const void *__src, size_t __n) __alias(memcpy);
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| 26 | void *__memmove(void *__dest, __const void *__src, size_t count) __alias(memmove);
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| 27 | void *__memset(void *s, int c, size_t count) __alias(memset);
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| 28 | #endif
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| 29 |
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| 30 | void *memcpy(void *__dest, __const void *__src, size_t __n)
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| 31 | {
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| 32 | int i = 0;
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| 33 | unsigned char *d = (unsigned char *)__dest, *s = (unsigned char *)__src;
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| 34 |
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| 35 | for (i = __n >> 3; i > 0; i--) {
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| 36 | *d++ = *s++;
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| 37 | *d++ = *s++;
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| 38 | *d++ = *s++;
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| 39 | *d++ = *s++;
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| 40 | *d++ = *s++;
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| 41 | *d++ = *s++;
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| 42 | *d++ = *s++;
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| 43 | *d++ = *s++;
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| 44 | }
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| 45 |
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| 46 | if (__n & 1 << 2) {
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| 47 | *d++ = *s++;
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| 48 | *d++ = *s++;
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| 49 | *d++ = *s++;
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| 50 | *d++ = *s++;
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| 51 | }
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| 52 |
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| 53 | if (__n & 1 << 1) {
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| 54 | *d++ = *s++;
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| 55 | *d++ = *s++;
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| 56 | }
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| 57 |
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| 58 | if (__n & 1)
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| 59 | *d++ = *s++;
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| 60 |
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| 61 | return __dest;
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| 62 | }
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| 63 |
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| 64 | void *memmove(void *__dest, __const void *__src, size_t count)
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| 65 | {
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| 66 | unsigned char *d = __dest;
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| 67 | const unsigned char *s = __src;
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| 68 |
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| 69 | if (__dest == __src)
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| 70 | return __dest;
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| 71 |
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| 72 | if (__dest < __src)
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| 73 | return memcpy(__dest, __src, count);
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| 74 |
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| 75 | while (count--)
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| 76 | d[count] = s[count];
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| 77 | return __dest;
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| 78 | }
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| 79 |
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| 80 | size_t strlen(const char *s)
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| 81 | {
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| 82 | const char *sc = s;
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| 83 |
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| 84 | while (*sc != '\0')
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| 85 | sc++;
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| 86 | return sc - s;
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| 87 | }
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| 88 |
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| 89 | size_t strnlen(const char *s, size_t count)
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| 90 | {
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| 91 | const char *sc;
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| 92 |
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| 93 | for (sc = s; count-- && *sc != '\0'; ++sc)
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| 94 | ;
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| 95 | return sc - s;
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| 96 | }
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| 97 |
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| 98 | int memcmp(const void *cs, const void *ct, size_t count)
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| 99 | {
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| 100 | const unsigned char *su1 = cs, *su2 = ct, *end = su1 + count;
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| 101 | int res = 0;
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| 102 |
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| 103 | while (su1 < end) {
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| 104 | res = *su1++ - *su2++;
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| 105 | if (res)
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| 106 | break;
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| 107 | }
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| 108 | return res;
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| 109 | }
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| 110 |
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| 111 | int strcmp(const char *cs, const char *ct)
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| 112 | {
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| 113 | unsigned char c1, c2;
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| 114 | int res = 0;
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| 115 |
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| 116 | do {
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| 117 | c1 = *cs++;
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| 118 | c2 = *ct++;
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| 119 | res = c1 - c2;
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| 120 | if (res)
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| 121 | break;
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| 122 | } while (c1);
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| 123 | return res;
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| 124 | }
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| 125 |
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| 126 | void *memchr(const void *s, int c, size_t count)
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| 127 | {
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| 128 | const unsigned char *p = s;
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| 129 |
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| 130 | while (count--)
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| 131 | if ((unsigned char)c == *p++)
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| 132 | return (void *)(p - 1);
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| 133 | return NULL;
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| 134 | }
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| 135 |
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| 136 | char *strchr(const char *s, int c)
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| 137 | {
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| 138 | while (*s != (char)c)
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| 139 | if (*s++ == '\0')
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| 140 | return NULL;
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| 141 | return (char *)s;
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| 142 | }
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| 143 |
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| 144 | char *strrchr(const char *s, int c)
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| 145 | {
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| 146 | const char *last = NULL;
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| 147 | do {
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| 148 | if (*s == (char)c)
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| 149 | last = s;
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| 150 | } while (*s++);
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| 151 | return (char *)last;
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| 152 | }
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| 153 |
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| 154 | #undef memset
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| 155 |
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| 156 | void *memset(void *s, int c, size_t count)
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| 157 | {
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| 158 | char *xs = s;
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| 159 | while (count--)
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| 160 | *xs++ = c;
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| 161 | return s;
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| 162 | }
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