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
_parse_integer_fixup_radix(const char * s,unsigned int * base)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 */
_parse_integer(const char * s,unsigned int base,unsigned long long * p)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
_kstrtoull(const char * s,unsigned int base,unsigned long long * res)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
kstrtoull(const char * s,unsigned int base,unsigned long long * res)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
kstrtoll(const char * s,unsigned int base,long long * res)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. */
_kstrtoul(const char * s,unsigned int base,unsigned long * res)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. */
_kstrtol(const char * s,unsigned int base,long * res)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
kstrtouint(const char * s,unsigned int base,unsigned int * res)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
kstrtoint(const char * s,unsigned int base,int * res)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
kstrtou16(const char * s,unsigned int base,u16 * res)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
kstrtos16(const char * s,unsigned int base,s16 * res)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
kstrtou8(const char * s,unsigned int base,u8 * res)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
kstrtos8(const char * s,unsigned int base,s8 * res)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