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| 1 | +// SPDX-License-Identifier: GPL-2.0-only |
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| 1 | 2 | /* -*- linux-c -*- ------------------------------------------------------- * |
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| 2 | 3 | * |
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| 3 | 4 | * Copyright (C) 1991, 1992 Linus Torvalds |
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| 4 | 5 | * Copyright 2007 rPath, Inc. - All Rights Reserved |
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| 5 | | - * |
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| 6 | | - * This file is part of the Linux kernel, and is made available under |
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| 7 | | - * the terms of the GNU General Public License version 2. |
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| 8 | 6 | * |
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| 9 | 7 | * ----------------------------------------------------------------------- */ |
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| 10 | 8 | |
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| .. | .. |
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| 13 | 11 | */ |
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| 14 | 12 | |
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| 15 | 13 | #include <linux/types.h> |
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| 14 | +#include <linux/compiler.h> |
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| 15 | +#include <linux/errno.h> |
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| 16 | +#include <linux/limits.h> |
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| 16 | 17 | #include <asm/asm.h> |
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| 17 | 18 | #include "ctype.h" |
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| 18 | 19 | #include "string.h" |
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| 20 | + |
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| 21 | +#define KSTRTOX_OVERFLOW (1U << 31) |
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| 19 | 22 | |
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| 20 | 23 | /* |
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| 21 | 24 | * Undef these macros so that the functions that we provide |
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| .. | .. |
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| 114 | 117 | * @endp: A pointer to the end of the parsed string will be placed here |
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| 115 | 118 | * @base: The number base to use |
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| 116 | 119 | */ |
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| 117 | | - |
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| 118 | 120 | unsigned long long simple_strtoull(const char *cp, char **endp, unsigned int base) |
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| 119 | 121 | { |
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| 120 | 122 | unsigned long long result = 0; |
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| .. | .. |
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| 195 | 197 | return NULL; |
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| 196 | 198 | return (char *)s; |
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| 197 | 199 | } |
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| 200 | + |
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| 201 | +static inline u64 __div_u64_rem(u64 dividend, u32 divisor, u32 *remainder) |
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| 202 | +{ |
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| 203 | + union { |
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| 204 | + u64 v64; |
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| 205 | + u32 v32[2]; |
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| 206 | + } d = { dividend }; |
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| 207 | + u32 upper; |
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| 208 | + |
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| 209 | + upper = d.v32[1]; |
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| 210 | + d.v32[1] = 0; |
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| 211 | + if (upper >= divisor) { |
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| 212 | + d.v32[1] = upper / divisor; |
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| 213 | + upper %= divisor; |
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| 214 | + } |
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| 215 | + asm ("divl %2" : "=a" (d.v32[0]), "=d" (*remainder) : |
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| 216 | + "rm" (divisor), "0" (d.v32[0]), "1" (upper)); |
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| 217 | + return d.v64; |
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| 218 | +} |
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| 219 | + |
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| 220 | +static inline u64 __div_u64(u64 dividend, u32 divisor) |
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| 221 | +{ |
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| 222 | + u32 remainder; |
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| 223 | + |
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| 224 | + return __div_u64_rem(dividend, divisor, &remainder); |
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| 225 | +} |
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| 226 | + |
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| 227 | +static inline char _tolower(const char c) |
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| 228 | +{ |
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| 229 | + return c | 0x20; |
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| 230 | +} |
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| 231 | + |
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| 232 | +static const char *_parse_integer_fixup_radix(const char *s, unsigned int *base) |
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| 233 | +{ |
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| 234 | + if (*base == 0) { |
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| 235 | + if (s[0] == '0') { |
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| 236 | + if (_tolower(s[1]) == 'x' && isxdigit(s[2])) |
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| 237 | + *base = 16; |
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| 238 | + else |
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| 239 | + *base = 8; |
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| 240 | + } else |
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| 241 | + *base = 10; |
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| 242 | + } |
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| 243 | + if (*base == 16 && s[0] == '0' && _tolower(s[1]) == 'x') |
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| 244 | + s += 2; |
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| 245 | + return s; |
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| 246 | +} |
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| 247 | + |
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| 248 | +/* |
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| 249 | + * Convert non-negative integer string representation in explicitly given radix |
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| 250 | + * to an integer. |
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| 251 | + * Return number of characters consumed maybe or-ed with overflow bit. |
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| 252 | + * If overflow occurs, result integer (incorrect) is still returned. |
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| 253 | + * |
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| 254 | + * Don't you dare use this function. |
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| 255 | + */ |
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| 256 | +static unsigned int _parse_integer(const char *s, |
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| 257 | + unsigned int base, |
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| 258 | + unsigned long long *p) |
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| 259 | +{ |
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| 260 | + unsigned long long res; |
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| 261 | + unsigned int rv; |
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| 262 | + |
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| 263 | + res = 0; |
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| 264 | + rv = 0; |
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| 265 | + while (1) { |
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| 266 | + unsigned int c = *s; |
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| 267 | + unsigned int lc = c | 0x20; /* don't tolower() this line */ |
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| 268 | + unsigned int val; |
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| 269 | + |
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| 270 | + if ('0' <= c && c <= '9') |
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| 271 | + val = c - '0'; |
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| 272 | + else if ('a' <= lc && lc <= 'f') |
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| 273 | + val = lc - 'a' + 10; |
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| 274 | + else |
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| 275 | + break; |
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| 276 | + |
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| 277 | + if (val >= base) |
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| 278 | + break; |
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| 279 | + /* |
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| 280 | + * Check for overflow only if we are within range of |
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| 281 | + * it in the max base we support (16) |
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| 282 | + */ |
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| 283 | + if (unlikely(res & (~0ull << 60))) { |
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| 284 | + if (res > __div_u64(ULLONG_MAX - val, base)) |
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| 285 | + rv |= KSTRTOX_OVERFLOW; |
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| 286 | + } |
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| 287 | + res = res * base + val; |
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| 288 | + rv++; |
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| 289 | + s++; |
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| 290 | + } |
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| 291 | + *p = res; |
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| 292 | + return rv; |
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| 293 | +} |
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| 294 | + |
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| 295 | +static int _kstrtoull(const char *s, unsigned int base, unsigned long long *res) |
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| 296 | +{ |
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| 297 | + unsigned long long _res; |
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| 298 | + unsigned int rv; |
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| 299 | + |
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| 300 | + s = _parse_integer_fixup_radix(s, &base); |
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| 301 | + rv = _parse_integer(s, base, &_res); |
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| 302 | + if (rv & KSTRTOX_OVERFLOW) |
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| 303 | + return -ERANGE; |
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| 304 | + if (rv == 0) |
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| 305 | + return -EINVAL; |
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| 306 | + s += rv; |
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| 307 | + if (*s == '\n') |
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| 308 | + s++; |
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| 309 | + if (*s) |
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| 310 | + return -EINVAL; |
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| 311 | + *res = _res; |
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| 312 | + return 0; |
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| 313 | +} |
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| 314 | + |
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| 315 | +/** |
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| 316 | + * kstrtoull - convert a string to an unsigned long long |
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| 317 | + * @s: The start of the string. The string must be null-terminated, and may also |
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| 318 | + * include a single newline before its terminating null. The first character |
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| 319 | + * may also be a plus sign, but not a minus sign. |
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| 320 | + * @base: The number base to use. The maximum supported base is 16. If base is |
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| 321 | + * given as 0, then the base of the string is automatically detected with the |
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| 322 | + * conventional semantics - If it begins with 0x the number will be parsed as a |
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| 323 | + * hexadecimal (case insensitive), if it otherwise begins with 0, it will be |
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| 324 | + * parsed as an octal number. Otherwise it will be parsed as a decimal. |
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| 325 | + * @res: Where to write the result of the conversion on success. |
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| 326 | + * |
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| 327 | + * Returns 0 on success, -ERANGE on overflow and -EINVAL on parsing error. |
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| 328 | + * Used as a replacement for the obsolete simple_strtoull. Return code must |
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| 329 | + * be checked. |
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| 330 | + */ |
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| 331 | +int kstrtoull(const char *s, unsigned int base, unsigned long long *res) |
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| 332 | +{ |
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| 333 | + if (s[0] == '+') |
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| 334 | + s++; |
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| 335 | + return _kstrtoull(s, base, res); |
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| 336 | +} |
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| 337 | + |
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| 338 | +static int _kstrtoul(const char *s, unsigned int base, unsigned long *res) |
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| 339 | +{ |
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| 340 | + unsigned long long tmp; |
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| 341 | + int rv; |
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| 342 | + |
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| 343 | + rv = kstrtoull(s, base, &tmp); |
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| 344 | + if (rv < 0) |
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| 345 | + return rv; |
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| 346 | + if (tmp != (unsigned long)tmp) |
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| 347 | + return -ERANGE; |
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| 348 | + *res = tmp; |
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| 349 | + return 0; |
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| 350 | +} |
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| 351 | + |
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| 352 | +/** |
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| 353 | + * kstrtoul - convert a string to an unsigned long |
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| 354 | + * @s: The start of the string. The string must be null-terminated, and may also |
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| 355 | + * include a single newline before its terminating null. The first character |
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| 356 | + * may also be a plus sign, but not a minus sign. |
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| 357 | + * @base: The number base to use. The maximum supported base is 16. If base is |
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| 358 | + * given as 0, then the base of the string is automatically detected with the |
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| 359 | + * conventional semantics - If it begins with 0x the number will be parsed as a |
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| 360 | + * hexadecimal (case insensitive), if it otherwise begins with 0, it will be |
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| 361 | + * parsed as an octal number. Otherwise it will be parsed as a decimal. |
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| 362 | + * @res: Where to write the result of the conversion on success. |
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| 363 | + * |
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| 364 | + * Returns 0 on success, -ERANGE on overflow and -EINVAL on parsing error. |
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| 365 | + * Used as a replacement for the simple_strtoull. |
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| 366 | + */ |
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| 367 | +int boot_kstrtoul(const char *s, unsigned int base, unsigned long *res) |
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| 368 | +{ |
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| 369 | + /* |
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| 370 | + * We want to shortcut function call, but |
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| 371 | + * __builtin_types_compatible_p(unsigned long, unsigned long long) = 0. |
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| 372 | + */ |
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| 373 | + if (sizeof(unsigned long) == sizeof(unsigned long long) && |
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| 374 | + __alignof__(unsigned long) == __alignof__(unsigned long long)) |
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| 375 | + return kstrtoull(s, base, (unsigned long long *)res); |
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| 376 | + else |
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| 377 | + return _kstrtoul(s, base, res); |
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| 378 | +} |
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