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 22 static int _kstrtoull(const char *s, unsigned int base, unsigned long long *res) 23 { 24 unsigned long long acc; 25 int ok; 26 27 if (base == 0) { 28 if (s[0] == '0') { 29 if (_tolower(s[1]) == 'x' && isxdigit(s[2])) 30 base = 16; 31 else 32 base = 8; 33 } else 34 base = 10; 35 } 36 if (base == 16 && s[0] == '0' && _tolower(s[1]) == 'x') 37 s += 2; 38 39 acc = 0; 40 ok = 0; 41 while (*s) { 42 unsigned int val; 43 44 if ('0' <= *s && *s <= '9') 45 val = *s - '0'; 46 else if ('a' <= _tolower(*s) && _tolower(*s) <= 'f') 47 val = _tolower(*s) - 'a' + 10; 48 else if (*s == '\n' && *(s + 1) == '\0') 49 break; 50 else 51 return -EINVAL; 52 53 if (val >= base) 54 return -EINVAL; 55 if (acc > div_u64(ULLONG_MAX - val, base)) 56 return -ERANGE; 57 acc = acc * base + val; 58 ok = 1; 59 60 s++; 61 } 62 if (!ok) 63 return -EINVAL; 64 *res = acc; 65 return 0; 66 } 67 68 int kstrtoull(const char *s, unsigned int base, unsigned long long *res) 69 { 70 if (s[0] == '+') 71 s++; 72 return _kstrtoull(s, base, res); 73 } 74 EXPORT_SYMBOL(kstrtoull); 75 76 int kstrtoll(const char *s, unsigned int base, long long *res) 77 { 78 unsigned long long tmp; 79 int rv; 80 81 if (s[0] == '-') { 82 rv = _kstrtoull(s + 1, base, &tmp); 83 if (rv < 0) 84 return rv; 85 if ((long long)(-tmp) >= 0) 86 return -ERANGE; 87 *res = -tmp; 88 } else { 89 rv = kstrtoull(s, base, &tmp); 90 if (rv < 0) 91 return rv; 92 if ((long long)tmp < 0) 93 return -ERANGE; 94 *res = tmp; 95 } 96 return 0; 97 } 98 EXPORT_SYMBOL(kstrtoll); 99 100 /* Internal, do not use. */ 101 int _kstrtoul(const char *s, unsigned int base, unsigned long *res) 102 { 103 unsigned long long tmp; 104 int rv; 105 106 rv = kstrtoull(s, base, &tmp); 107 if (rv < 0) 108 return rv; 109 if (tmp != (unsigned long long)(unsigned long)tmp) 110 return -ERANGE; 111 *res = tmp; 112 return 0; 113 } 114 EXPORT_SYMBOL(_kstrtoul); 115 116 /* Internal, do not use. */ 117 int _kstrtol(const char *s, unsigned int base, long *res) 118 { 119 long long tmp; 120 int rv; 121 122 rv = kstrtoll(s, base, &tmp); 123 if (rv < 0) 124 return rv; 125 if (tmp != (long long)(long)tmp) 126 return -ERANGE; 127 *res = tmp; 128 return 0; 129 } 130 EXPORT_SYMBOL(_kstrtol); 131 132 int kstrtouint(const char *s, unsigned int base, unsigned int *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 int)tmp) 141 return -ERANGE; 142 *res = tmp; 143 return 0; 144 } 145 EXPORT_SYMBOL(kstrtouint); 146 147 int kstrtoint(const char *s, unsigned int base, int *res) 148 { 149 long long tmp; 150 int rv; 151 152 rv = kstrtoll(s, base, &tmp); 153 if (rv < 0) 154 return rv; 155 if (tmp != (long long)(int)tmp) 156 return -ERANGE; 157 *res = tmp; 158 return 0; 159 } 160 EXPORT_SYMBOL(kstrtoint); 161 162 int kstrtou16(const char *s, unsigned int base, u16 *res) 163 { 164 unsigned long long tmp; 165 int rv; 166 167 rv = kstrtoull(s, base, &tmp); 168 if (rv < 0) 169 return rv; 170 if (tmp != (unsigned long long)(u16)tmp) 171 return -ERANGE; 172 *res = tmp; 173 return 0; 174 } 175 EXPORT_SYMBOL(kstrtou16); 176 177 int kstrtos16(const char *s, unsigned int base, s16 *res) 178 { 179 long long tmp; 180 int rv; 181 182 rv = kstrtoll(s, base, &tmp); 183 if (rv < 0) 184 return rv; 185 if (tmp != (long long)(s16)tmp) 186 return -ERANGE; 187 *res = tmp; 188 return 0; 189 } 190 EXPORT_SYMBOL(kstrtos16); 191 192 int kstrtou8(const char *s, unsigned int base, u8 *res) 193 { 194 unsigned long long tmp; 195 int rv; 196 197 rv = kstrtoull(s, base, &tmp); 198 if (rv < 0) 199 return rv; 200 if (tmp != (unsigned long long)(u8)tmp) 201 return -ERANGE; 202 *res = tmp; 203 return 0; 204 } 205 EXPORT_SYMBOL(kstrtou8); 206 207 int kstrtos8(const char *s, unsigned int base, s8 *res) 208 { 209 long long tmp; 210 int rv; 211 212 rv = kstrtoll(s, base, &tmp); 213 if (rv < 0) 214 return rv; 215 if (tmp != (long long)(s8)tmp) 216 return -ERANGE; 217 *res = tmp; 218 return 0; 219 } 220 EXPORT_SYMBOL(kstrtos8); 221 222 #define kstrto_from_user(f, g, type) \ 223 int f(const char __user *s, size_t count, unsigned int base, type *res) \ 224 { \ 225 /* sign, base 2 representation, newline, terminator */ \ 226 char buf[1 + sizeof(type) * 8 + 1 + 1]; \ 227 \ 228 count = min(count, sizeof(buf) - 1); \ 229 if (copy_from_user(buf, s, count)) \ 230 return -EFAULT; \ 231 buf[count] = '\0'; \ 232 return g(buf, base, res); \ 233 } \ 234 EXPORT_SYMBOL(f) 235 236 kstrto_from_user(kstrtoull_from_user, kstrtoull, unsigned long long); 237 kstrto_from_user(kstrtoll_from_user, kstrtoll, long long); 238 kstrto_from_user(kstrtoul_from_user, kstrtoul, unsigned long); 239 kstrto_from_user(kstrtol_from_user, kstrtol, long); 240 kstrto_from_user(kstrtouint_from_user, kstrtouint, unsigned int); 241 kstrto_from_user(kstrtoint_from_user, kstrtoint, int); 242 kstrto_from_user(kstrtou16_from_user, kstrtou16, u16); 243 kstrto_from_user(kstrtos16_from_user, kstrtos16, s16); 244 kstrto_from_user(kstrtou8_from_user, kstrtou8, u8); 245 kstrto_from_user(kstrtos8_from_user, kstrtos8, s8); 246