tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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
23const 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 */
47unsigned 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
78static 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
99int 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}
105EXPORT_SYMBOL(kstrtoull);
106
107int 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}
129EXPORT_SYMBOL(kstrtoll);
130
131/* Internal, do not use. */
132int _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}
145EXPORT_SYMBOL(_kstrtoul);
146
147/* Internal, do not use. */
148int _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}
161EXPORT_SYMBOL(_kstrtol);
162
163int 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}
176EXPORT_SYMBOL(kstrtouint);
177
178int 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}
191EXPORT_SYMBOL(kstrtoint);
192
193int 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}
206EXPORT_SYMBOL(kstrtou16);
207
208int 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}
221EXPORT_SYMBOL(kstrtos16);
222
223int 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}
236EXPORT_SYMBOL(kstrtou8);
237
238int 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}
251EXPORT_SYMBOL(kstrtos8);
252
253#define kstrto_from_user(f, g, type) \
254int 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} \
265EXPORT_SYMBOL(f)
266
267kstrto_from_user(kstrtoull_from_user, kstrtoull, unsigned long long);
268kstrto_from_user(kstrtoll_from_user, kstrtoll, long long);
269kstrto_from_user(kstrtoul_from_user, kstrtoul, unsigned long);
270kstrto_from_user(kstrtol_from_user, kstrtol, long);
271kstrto_from_user(kstrtouint_from_user, kstrtouint, unsigned int);
272kstrto_from_user(kstrtoint_from_user, kstrtoint, int);
273kstrto_from_user(kstrtou16_from_user, kstrtou16, u16);
274kstrto_from_user(kstrtos16_from_user, kstrtos16, s16);
275kstrto_from_user(kstrtou8_from_user, kstrtou8, u8);
276kstrto_from_user(kstrtos8_from_user, kstrtos8, s8);