Root/lib/kstrtox.c

Source at commit b386be689295730688885552666ea40b2e639b14 created 8 years 11 months ago.
By Maarten ter Huurne, Revert "MIPS: JZ4740: reset: Initialize hibernate wakeup counters."
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 *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
86static 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
107int 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}
113EXPORT_SYMBOL(kstrtoull);
114
115int 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}
137EXPORT_SYMBOL(kstrtoll);
138
139/* Internal, do not use. */
140int _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}
153EXPORT_SYMBOL(_kstrtoul);
154
155/* Internal, do not use. */
156int _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}
169EXPORT_SYMBOL(_kstrtol);
170
171int 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}
184EXPORT_SYMBOL(kstrtouint);
185
186int 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}
199EXPORT_SYMBOL(kstrtoint);
200
201int 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}
214EXPORT_SYMBOL(kstrtou16);
215
216int 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}
229EXPORT_SYMBOL(kstrtos16);
230
231int 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}
244EXPORT_SYMBOL(kstrtou8);
245
246int 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}
259EXPORT_SYMBOL(kstrtos8);
260
261#define kstrto_from_user(f, g, type) \
262int 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} \
273EXPORT_SYMBOL(f)
274
275kstrto_from_user(kstrtoull_from_user, kstrtoull, unsigned long long);
276kstrto_from_user(kstrtoll_from_user, kstrtoll, long long);
277kstrto_from_user(kstrtoul_from_user, kstrtoul, unsigned long);
278kstrto_from_user(kstrtol_from_user, kstrtol, long);
279kstrto_from_user(kstrtouint_from_user, kstrtouint, unsigned int);
280kstrto_from_user(kstrtoint_from_user, kstrtoint, int);
281kstrto_from_user(kstrtou16_from_user, kstrtou16, u16);
282kstrto_from_user(kstrtos16_from_user, kstrtos16, s16);
283kstrto_from_user(kstrtou8_from_user, kstrtou8, u8);
284kstrto_from_user(kstrtos8_from_user, kstrtos8, s8);
285

Archive Download this file



interactive