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/module.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 *res) 48 { 49 unsigned int rv; 50 int overflow; 51 52 *res = 0; 53 rv = 0; 54 overflow = 0; 55 while (*s) { 56 unsigned int val; 57 58 if ('0' <= *s && *s <= '9') 59 val = *s - '0'; 60 else if ('a' <= _tolower(*s) && _tolower(*s) <= 'f') 61 val = _tolower(*s) - 'a' + 10; 62 else 63 break; 64 65 if (val >= base) 66 break; 67 if (*res > div_u64(ULLONG_MAX - val, base)) 68 overflow = 1; 69 *res = *res * base + val; 70 rv++; 71 s++; 72 } 73 if (overflow) 74 rv |= KSTRTOX_OVERFLOW; 75 return rv; 76 } 77 78 static int _kstrtoull(const char *s, unsigned int base, unsigned long long *res) 79 { 80 unsigned long long _res; 81 unsigned int rv; 82 83 s = _parse_integer_fixup_radix(s, &base); 84 rv = _parse_integer(s, base, &_res); 85 if (rv & KSTRTOX_OVERFLOW) 86 return -ERANGE; 87 rv &= ~KSTRTOX_OVERFLOW; 88 if (rv == 0) 89 return -EINVAL; 90 s += rv; 91 if (*s == '\n') 92 s++; 93 if (*s) 94 return -EINVAL; 95 *res = _res; 96 return 0; 97 } 98 99 int kstrtoull(const char *s, unsigned int base, unsigned long long *res) 100 { 101 if (s[0] == '+') 102 s++; 103 return _kstrtoull(s, base, res); 104 } 105 EXPORT_SYMBOL(kstrtoull); 106 107 int kstrtoll(const char *s, unsigned int base, long long *res) 108 { 109 unsigned long long tmp; 110 int rv; 111 112 if (s[0] == '-') { 113 rv = _kstrtoull(s + 1, base, &tmp); 114 if (rv < 0) 115 return rv; 116 if ((long long)(-tmp) >= 0) 117 return -ERANGE; 118 *res = -tmp; 119 } else { 120 rv = kstrtoull(s, base, &tmp); 121 if (rv < 0) 122 return rv; 123 if ((long long)tmp < 0) 124 return -ERANGE; 125 *res = tmp; 126 } 127 return 0; 128 } 129 EXPORT_SYMBOL(kstrtoll); 130 131 /* Internal, do not use. */ 132 int _kstrtoul(const char *s, unsigned int base, unsigned long *res) 133 { 134 unsigned long long tmp; 135 int rv; 136 137 rv = kstrtoull(s, base, &tmp); 138 if (rv < 0) 139 return rv; 140 if (tmp != (unsigned long long)(unsigned long)tmp) 141 return -ERANGE; 142 *res = tmp; 143 return 0; 144 } 145 EXPORT_SYMBOL(_kstrtoul); 146 147 /* Internal, do not use. */ 148 int _kstrtol(const char *s, unsigned int base, long *res) 149 { 150 long long tmp; 151 int rv; 152 153 rv = kstrtoll(s, base, &tmp); 154 if (rv < 0) 155 return rv; 156 if (tmp != (long long)(long)tmp) 157 return -ERANGE; 158 *res = tmp; 159 return 0; 160 } 161 EXPORT_SYMBOL(_kstrtol); 162 163 int kstrtouint(const char *s, unsigned int base, unsigned int *res) 164 { 165 unsigned long long tmp; 166 int rv; 167 168 rv = kstrtoull(s, base, &tmp); 169 if (rv < 0) 170 return rv; 171 if (tmp != (unsigned long long)(unsigned int)tmp) 172 return -ERANGE; 173 *res = tmp; 174 return 0; 175 } 176 EXPORT_SYMBOL(kstrtouint); 177 178 int kstrtoint(const char *s, unsigned int base, int *res) 179 { 180 long long tmp; 181 int rv; 182 183 rv = kstrtoll(s, base, &tmp); 184 if (rv < 0) 185 return rv; 186 if (tmp != (long long)(int)tmp) 187 return -ERANGE; 188 *res = tmp; 189 return 0; 190 } 191 EXPORT_SYMBOL(kstrtoint); 192 193 int kstrtou16(const char *s, unsigned int base, u16 *res) 194 { 195 unsigned long long tmp; 196 int rv; 197 198 rv = kstrtoull(s, base, &tmp); 199 if (rv < 0) 200 return rv; 201 if (tmp != (unsigned long long)(u16)tmp) 202 return -ERANGE; 203 *res = tmp; 204 return 0; 205 } 206 EXPORT_SYMBOL(kstrtou16); 207 208 int kstrtos16(const char *s, unsigned int base, s16 *res) 209 { 210 long long tmp; 211 int rv; 212 213 rv = kstrtoll(s, base, &tmp); 214 if (rv < 0) 215 return rv; 216 if (tmp != (long long)(s16)tmp) 217 return -ERANGE; 218 *res = tmp; 219 return 0; 220 } 221 EXPORT_SYMBOL(kstrtos16); 222 223 int kstrtou8(const char *s, unsigned int base, u8 *res) 224 { 225 unsigned long long tmp; 226 int rv; 227 228 rv = kstrtoull(s, base, &tmp); 229 if (rv < 0) 230 return rv; 231 if (tmp != (unsigned long long)(u8)tmp) 232 return -ERANGE; 233 *res = tmp; 234 return 0; 235 } 236 EXPORT_SYMBOL(kstrtou8); 237 238 int kstrtos8(const char *s, unsigned int base, s8 *res) 239 { 240 long long tmp; 241 int rv; 242 243 rv = kstrtoll(s, base, &tmp); 244 if (rv < 0) 245 return rv; 246 if (tmp != (long long)(s8)tmp) 247 return -ERANGE; 248 *res = tmp; 249 return 0; 250 } 251 EXPORT_SYMBOL(kstrtos8); 252 253 #define kstrto_from_user(f, g, type) \ 254 int f(const char __user *s, size_t count, unsigned int base, type *res) \ 255 { \ 256 /* sign, base 2 representation, newline, terminator */ \ 257 char buf[1 + sizeof(type) * 8 + 1 + 1]; \ 258 \ 259 count = min(count, sizeof(buf) - 1); \ 260 if (copy_from_user(buf, s, count)) \ 261 return -EFAULT; \ 262 buf[count] = '\0'; \ 263 return g(buf, base, res); \ 264 } \ 265 EXPORT_SYMBOL(f) 266 267 kstrto_from_user(kstrtoull_from_user, kstrtoull, unsigned long long); 268 kstrto_from_user(kstrtoll_from_user, kstrtoll, long long); 269 kstrto_from_user(kstrtoul_from_user, kstrtoul, unsigned long); 270 kstrto_from_user(kstrtol_from_user, kstrtol, long); 271 kstrto_from_user(kstrtouint_from_user, kstrtouint, unsigned int); 272 kstrto_from_user(kstrtoint_from_user, kstrtoint, int); 273 kstrto_from_user(kstrtou16_from_user, kstrtou16, u16); 274 kstrto_from_user(kstrtos16_from_user, kstrtos16, s16); 275 kstrto_from_user(kstrtou8_from_user, kstrtou8, u8); 276 kstrto_from_user(kstrtos8_from_user, kstrtos8, s8); 277