1 /* 2 * Convert integer string representation to an integer. 3 * If an integer doesn't fit into specified type, -E is returned. 4 * 5 * Integer starts with optional sign. 6 * kstrtou*() functions do not accept sign "-". 7 * 8 * Radix 0 means autodetection: leading "0x" implies radix 16, 9 * leading "0" implies radix 8, otherwise radix is 10. 10 * Autodetection hints work after optional sign, but not before. 11 * 12 * If -E is returned, result is not touched. 13 */ 14 #include <linux/ctype.h> 15 #include <linux/errno.h> 16 #include <linux/kernel.h> 17 #include <linux/math64.h> 18 #include <linux/export.h> 19 #include <linux/types.h> 20 #include <asm/uaccess.h> 21 #include "kstrtox.h" 22 23 const char *_parse_integer_fixup_radix(const char *s, unsigned int *base) 24 { 25 if (*base == 0) { 26 if (s[0] == '0') { 27 if (_tolower(s[1]) == 'x' && isxdigit(s[2])) 28 *base = 16; 29 else 30 *base = 8; 31 } else 32 *base = 10; 33 } 34 if (*base == 16 && s[0] == '0' && _tolower(s[1]) == 'x') 35 s += 2; 36 return s; 37 } 38 39 /* 40 * Convert non-negative integer string representation in explicitly given radix 41 * to an integer. 42 * Return number of characters consumed maybe or-ed with overflow bit. 43 * If overflow occurs, result integer (incorrect) is still returned. 44 * 45 * Don't you dare use this function. 46 */ 47 unsigned int _parse_integer(const char *s, unsigned int base, unsigned long long *p) 48 { 49 unsigned long long res; 50 unsigned int rv; 51 int overflow; 52 53 res = 0; 54 rv = 0; 55 overflow = 0; 56 while (*s) { 57 unsigned int val; 58 59 if ('0' <= *s && *s <= '9') 60 val = *s - '0'; 61 else if ('a' <= _tolower(*s) && _tolower(*s) <= 'f') 62 val = _tolower(*s) - 'a' + 10; 63 else 64 break; 65 66 if (val >= base) 67 break; 68 /* 69 * Check for overflow only if we are within range of 70 * it in the max base we support (16) 71 */ 72 if (unlikely(res & (~0ull << 60))) { 73 if (res > div_u64(ULLONG_MAX - val, base)) 74 overflow = 1; 75 } 76 res = res * base + val; 77 rv++; 78 s++; 79 } 80 *p = res; 81 if (overflow) 82 rv |= KSTRTOX_OVERFLOW; 83 return rv; 84 } 85 86 static int _kstrtoull(const char *s, unsigned int base, unsigned long long *res) 87 { 88 unsigned long long _res; 89 unsigned int rv; 90 91 s = _parse_integer_fixup_radix(s, &base); 92 rv = _parse_integer(s, base, &_res); 93 if (rv & KSTRTOX_OVERFLOW) 94 return -ERANGE; 95 rv &= ~KSTRTOX_OVERFLOW; 96 if (rv == 0) 97 return -EINVAL; 98 s += rv; 99 if (*s == '\n') 100 s++; 101 if (*s) 102 return -EINVAL; 103 *res = _res; 104 return 0; 105 } 106 107 int kstrtoull(const char *s, unsigned int base, unsigned long long *res) 108 { 109 if (s[0] == '+') 110 s++; 111 return _kstrtoull(s, base, res); 112 } 113 EXPORT_SYMBOL(kstrtoull); 114 115 int kstrtoll(const char *s, unsigned int base, long long *res) 116 { 117 unsigned long long tmp; 118 int rv; 119 120 if (s[0] == '-') { 121 rv = _kstrtoull(s + 1, base, &tmp); 122 if (rv < 0) 123 return rv; 124 if ((long long)(-tmp) >= 0) 125 return -ERANGE; 126 *res = -tmp; 127 } else { 128 rv = kstrtoull(s, base, &tmp); 129 if (rv < 0) 130 return rv; 131 if ((long long)tmp < 0) 132 return -ERANGE; 133 *res = tmp; 134 } 135 return 0; 136 } 137 EXPORT_SYMBOL(kstrtoll); 138 139 /* Internal, do not use. */ 140 int _kstrtoul(const char *s, unsigned int base, unsigned long *res) 141 { 142 unsigned long long tmp; 143 int rv; 144 145 rv = kstrtoull(s, base, &tmp); 146 if (rv < 0) 147 return rv; 148 if (tmp != (unsigned long long)(unsigned long)tmp) 149 return -ERANGE; 150 *res = tmp; 151 return 0; 152 } 153 EXPORT_SYMBOL(_kstrtoul); 154 155 /* Internal, do not use. */ 156 int _kstrtol(const char *s, unsigned int base, long *res) 157 { 158 long long tmp; 159 int rv; 160 161 rv = kstrtoll(s, base, &tmp); 162 if (rv < 0) 163 return rv; 164 if (tmp != (long long)(long)tmp) 165 return -ERANGE; 166 *res = tmp; 167 return 0; 168 } 169 EXPORT_SYMBOL(_kstrtol); 170 171 int kstrtouint(const char *s, unsigned int base, unsigned int *res) 172 { 173 unsigned long long tmp; 174 int rv; 175 176 rv = kstrtoull(s, base, &tmp); 177 if (rv < 0) 178 return rv; 179 if (tmp != (unsigned long long)(unsigned int)tmp) 180 return -ERANGE; 181 *res = tmp; 182 return 0; 183 } 184 EXPORT_SYMBOL(kstrtouint); 185 186 int kstrtoint(const char *s, unsigned int base, int *res) 187 { 188 long long tmp; 189 int rv; 190 191 rv = kstrtoll(s, base, &tmp); 192 if (rv < 0) 193 return rv; 194 if (tmp != (long long)(int)tmp) 195 return -ERANGE; 196 *res = tmp; 197 return 0; 198 } 199 EXPORT_SYMBOL(kstrtoint); 200 201 int kstrtou16(const char *s, unsigned int base, u16 *res) 202 { 203 unsigned long long tmp; 204 int rv; 205 206 rv = kstrtoull(s, base, &tmp); 207 if (rv < 0) 208 return rv; 209 if (tmp != (unsigned long long)(u16)tmp) 210 return -ERANGE; 211 *res = tmp; 212 return 0; 213 } 214 EXPORT_SYMBOL(kstrtou16); 215 216 int kstrtos16(const char *s, unsigned int base, s16 *res) 217 { 218 long long tmp; 219 int rv; 220 221 rv = kstrtoll(s, base, &tmp); 222 if (rv < 0) 223 return rv; 224 if (tmp != (long long)(s16)tmp) 225 return -ERANGE; 226 *res = tmp; 227 return 0; 228 } 229 EXPORT_SYMBOL(kstrtos16); 230 231 int kstrtou8(const char *s, unsigned int base, u8 *res) 232 { 233 unsigned long long tmp; 234 int rv; 235 236 rv = kstrtoull(s, base, &tmp); 237 if (rv < 0) 238 return rv; 239 if (tmp != (unsigned long long)(u8)tmp) 240 return -ERANGE; 241 *res = tmp; 242 return 0; 243 } 244 EXPORT_SYMBOL(kstrtou8); 245 246 int kstrtos8(const char *s, unsigned int base, s8 *res) 247 { 248 long long tmp; 249 int rv; 250 251 rv = kstrtoll(s, base, &tmp); 252 if (rv < 0) 253 return rv; 254 if (tmp != (long long)(s8)tmp) 255 return -ERANGE; 256 *res = tmp; 257 return 0; 258 } 259 EXPORT_SYMBOL(kstrtos8); 260 261 #define kstrto_from_user(f, g, type) \ 262 int f(const char __user *s, size_t count, unsigned int base, type *res) \ 263 { \ 264 /* sign, base 2 representation, newline, terminator */ \ 265 char buf[1 + sizeof(type) * 8 + 1 + 1]; \ 266 \ 267 count = min(count, sizeof(buf) - 1); \ 268 if (copy_from_user(buf, s, count)) \ 269 return -EFAULT; \ 270 buf[count] = '\0'; \ 271 return g(buf, base, res); \ 272 } \ 273 EXPORT_SYMBOL(f) 274 275 kstrto_from_user(kstrtoull_from_user, kstrtoull, unsigned long long); 276 kstrto_from_user(kstrtoll_from_user, kstrtoll, long long); 277 kstrto_from_user(kstrtoul_from_user, kstrtoul, unsigned long); 278 kstrto_from_user(kstrtol_from_user, kstrtol, long); 279 kstrto_from_user(kstrtouint_from_user, kstrtouint, unsigned int); 280 kstrto_from_user(kstrtoint_from_user, kstrtoint, int); 281 kstrto_from_user(kstrtou16_from_user, kstrtou16, u16); 282 kstrto_from_user(kstrtos16_from_user, kstrtos16, s16); 283 kstrto_from_user(kstrtou8_from_user, kstrtou8, u8); 284 kstrto_from_user(kstrtos8_from_user, kstrtos8, s8); 285