Merge branch 'for_linus' of git://cavan.codon.org.uk/platform-drivers-x86
[linux-2.6.git] / lib / kstrtox.c
blobf78ae0c0c4e2257cf96ab3a67b11f6bd6d9d11e0
1 /*
2 * Convert integer string representation to an integer.
3 * If an integer doesn't fit into specified type, -E is returned.
5 * Integer starts with optional sign.
6 * kstrtou*() functions do not accept sign "-".
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.
12 * If -E is returned, result is not touched.
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"
23 const char *_parse_integer_fixup_radix(const char *s, unsigned int *base)
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;
34 if (*base == 16 && s[0] == '0' && _tolower(s[1]) == 'x')
35 s += 2;
36 return s;
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.
45 * Don't you dare use this function.
47 unsigned int _parse_integer(const char *s, unsigned int base, unsigned long long *p)
49 unsigned long long res;
50 unsigned int rv;
51 int overflow;
53 res = 0;
54 rv = 0;
55 overflow = 0;
56 while (*s) {
57 unsigned int val;
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;
66 if (val >= base)
67 break;
69 * Check for overflow only if we are within range of
70 * it in the max base we support (16)
72 if (unlikely(res & (~0ull << 60))) {
73 if (res > div_u64(ULLONG_MAX - val, base))
74 overflow = 1;
76 res = res * base + val;
77 rv++;
78 s++;
80 *p = res;
81 if (overflow)
82 rv |= KSTRTOX_OVERFLOW;
83 return rv;
86 static int _kstrtoull(const char *s, unsigned int base, unsigned long long *res)
88 unsigned long long _res;
89 unsigned int rv;
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;
108 * kstrtoull - convert a string to an unsigned long long
109 * @s: The start of the string. The string must be null-terminated, and may also
110 * include a single newline before its terminating null. The first character
111 * may also be a plus sign, but not a minus sign.
112 * @base: The number base to use. The maximum supported base is 16. If base is
113 * given as 0, then the base of the string is automatically detected with the
114 * conventional semantics - If it begins with 0x the number will be parsed as a
115 * hexadecimal (case insensitive), if it otherwise begins with 0, it will be
116 * parsed as an octal number. Otherwise it will be parsed as a decimal.
117 * @res: Where to write the result of the conversion on success.
119 * Returns 0 on success, -ERANGE on overflow and -EINVAL on parsing error.
120 * Used as a replacement for the obsolete simple_strtoull. Return code must
121 * be checked.
123 int kstrtoull(const char *s, unsigned int base, unsigned long long *res)
125 if (s[0] == '+')
126 s++;
127 return _kstrtoull(s, base, res);
129 EXPORT_SYMBOL(kstrtoull);
132 * kstrtoll - convert a string to a long long
133 * @s: The start of the string. The string must be null-terminated, and may also
134 * include a single newline before its terminating null. The first character
135 * may also be a plus sign or a minus sign.
136 * @base: The number base to use. The maximum supported base is 16. If base is
137 * given as 0, then the base of the string is automatically detected with the
138 * conventional semantics - If it begins with 0x the number will be parsed as a
139 * hexadecimal (case insensitive), if it otherwise begins with 0, it will be
140 * parsed as an octal number. Otherwise it will be parsed as a decimal.
141 * @res: Where to write the result of the conversion on success.
143 * Returns 0 on success, -ERANGE on overflow and -EINVAL on parsing error.
144 * Used as a replacement for the obsolete simple_strtoull. Return code must
145 * be checked.
147 int kstrtoll(const char *s, unsigned int base, long long *res)
149 unsigned long long tmp;
150 int rv;
152 if (s[0] == '-') {
153 rv = _kstrtoull(s + 1, base, &tmp);
154 if (rv < 0)
155 return rv;
156 if ((long long)(-tmp) >= 0)
157 return -ERANGE;
158 *res = -tmp;
159 } else {
160 rv = kstrtoull(s, base, &tmp);
161 if (rv < 0)
162 return rv;
163 if ((long long)tmp < 0)
164 return -ERANGE;
165 *res = tmp;
167 return 0;
169 EXPORT_SYMBOL(kstrtoll);
171 /* Internal, do not use. */
172 int _kstrtoul(const char *s, unsigned int base, unsigned long *res)
174 unsigned long long tmp;
175 int rv;
177 rv = kstrtoull(s, base, &tmp);
178 if (rv < 0)
179 return rv;
180 if (tmp != (unsigned long long)(unsigned long)tmp)
181 return -ERANGE;
182 *res = tmp;
183 return 0;
185 EXPORT_SYMBOL(_kstrtoul);
187 /* Internal, do not use. */
188 int _kstrtol(const char *s, unsigned int base, long *res)
190 long long tmp;
191 int rv;
193 rv = kstrtoll(s, base, &tmp);
194 if (rv < 0)
195 return rv;
196 if (tmp != (long long)(long)tmp)
197 return -ERANGE;
198 *res = tmp;
199 return 0;
201 EXPORT_SYMBOL(_kstrtol);
204 * kstrtouint - convert a string to an unsigned int
205 * @s: The start of the string. The string must be null-terminated, and may also
206 * include a single newline before its terminating null. The first character
207 * may also be a plus sign, but not a minus sign.
208 * @base: The number base to use. The maximum supported base is 16. If base is
209 * given as 0, then the base of the string is automatically detected with the
210 * conventional semantics - If it begins with 0x the number will be parsed as a
211 * hexadecimal (case insensitive), if it otherwise begins with 0, it will be
212 * parsed as an octal number. Otherwise it will be parsed as a decimal.
213 * @res: Where to write the result of the conversion on success.
215 * Returns 0 on success, -ERANGE on overflow and -EINVAL on parsing error.
216 * Used as a replacement for the obsolete simple_strtoull. Return code must
217 * be checked.
219 int kstrtouint(const char *s, unsigned int base, unsigned int *res)
221 unsigned long long tmp;
222 int rv;
224 rv = kstrtoull(s, base, &tmp);
225 if (rv < 0)
226 return rv;
227 if (tmp != (unsigned long long)(unsigned int)tmp)
228 return -ERANGE;
229 *res = tmp;
230 return 0;
232 EXPORT_SYMBOL(kstrtouint);
235 * kstrtoint - convert a string to an int
236 * @s: The start of the string. The string must be null-terminated, and may also
237 * include a single newline before its terminating null. The first character
238 * may also be a plus sign or a minus sign.
239 * @base: The number base to use. The maximum supported base is 16. If base is
240 * given as 0, then the base of the string is automatically detected with the
241 * conventional semantics - If it begins with 0x the number will be parsed as a
242 * hexadecimal (case insensitive), if it otherwise begins with 0, it will be
243 * parsed as an octal number. Otherwise it will be parsed as a decimal.
244 * @res: Where to write the result of the conversion on success.
246 * Returns 0 on success, -ERANGE on overflow and -EINVAL on parsing error.
247 * Used as a replacement for the obsolete simple_strtoull. Return code must
248 * be checked.
250 int kstrtoint(const char *s, unsigned int base, int *res)
252 long long tmp;
253 int rv;
255 rv = kstrtoll(s, base, &tmp);
256 if (rv < 0)
257 return rv;
258 if (tmp != (long long)(int)tmp)
259 return -ERANGE;
260 *res = tmp;
261 return 0;
263 EXPORT_SYMBOL(kstrtoint);
265 int kstrtou16(const char *s, unsigned int base, u16 *res)
267 unsigned long long tmp;
268 int rv;
270 rv = kstrtoull(s, base, &tmp);
271 if (rv < 0)
272 return rv;
273 if (tmp != (unsigned long long)(u16)tmp)
274 return -ERANGE;
275 *res = tmp;
276 return 0;
278 EXPORT_SYMBOL(kstrtou16);
280 int kstrtos16(const char *s, unsigned int base, s16 *res)
282 long long tmp;
283 int rv;
285 rv = kstrtoll(s, base, &tmp);
286 if (rv < 0)
287 return rv;
288 if (tmp != (long long)(s16)tmp)
289 return -ERANGE;
290 *res = tmp;
291 return 0;
293 EXPORT_SYMBOL(kstrtos16);
295 int kstrtou8(const char *s, unsigned int base, u8 *res)
297 unsigned long long tmp;
298 int rv;
300 rv = kstrtoull(s, base, &tmp);
301 if (rv < 0)
302 return rv;
303 if (tmp != (unsigned long long)(u8)tmp)
304 return -ERANGE;
305 *res = tmp;
306 return 0;
308 EXPORT_SYMBOL(kstrtou8);
310 int kstrtos8(const char *s, unsigned int base, s8 *res)
312 long long tmp;
313 int rv;
315 rv = kstrtoll(s, base, &tmp);
316 if (rv < 0)
317 return rv;
318 if (tmp != (long long)(s8)tmp)
319 return -ERANGE;
320 *res = tmp;
321 return 0;
323 EXPORT_SYMBOL(kstrtos8);
325 #define kstrto_from_user(f, g, type) \
326 int f(const char __user *s, size_t count, unsigned int base, type *res) \
328 /* sign, base 2 representation, newline, terminator */ \
329 char buf[1 + sizeof(type) * 8 + 1 + 1]; \
331 count = min(count, sizeof(buf) - 1); \
332 if (copy_from_user(buf, s, count)) \
333 return -EFAULT; \
334 buf[count] = '\0'; \
335 return g(buf, base, res); \
337 EXPORT_SYMBOL(f)
339 kstrto_from_user(kstrtoull_from_user, kstrtoull, unsigned long long);
340 kstrto_from_user(kstrtoll_from_user, kstrtoll, long long);
341 kstrto_from_user(kstrtoul_from_user, kstrtoul, unsigned long);
342 kstrto_from_user(kstrtol_from_user, kstrtol, long);
343 kstrto_from_user(kstrtouint_from_user, kstrtouint, unsigned int);
344 kstrto_from_user(kstrtoint_from_user, kstrtoint, int);
345 kstrto_from_user(kstrtou16_from_user, kstrtou16, u16);
346 kstrto_from_user(kstrtos16_from_user, kstrtos16, s16);
347 kstrto_from_user(kstrtou8_from_user, kstrtou8, u8);
348 kstrto_from_user(kstrtos8_from_user, kstrtos8, s8);