[mirror_ubuntu-hirsute-kernel.git] / lib / kstrtox.c

// SPDX-License-Identifier: GPL-2.0
/*
 * Convert integer string representation to an integer.
 * If an integer doesn't fit into specified type, -E is returned.
 *
 * Integer starts with optional sign.
 * kstrtou*() functions do not accept sign "-".
 *
 * Radix 0 means autodetection: leading "0x" implies radix 16,
 * leading "0" implies radix 8, otherwise radix is 10.
 * Autodetection hints work after optional sign, but not before.
 *
 * If -E is returned, result is not touched.
 */
#include <linux/ctype.h>
#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/math64.h>
#include <linux/export.h>
#include <linux/types.h>
#include <linux/uaccess.h>
#include "kstrtox.h"

const char *_parse_integer_fixup_radix(const char *s, unsigned int *base)
{
	if (*base == 0) {
		if (s[0] == '0') {
			if (_tolower(s[1]) == 'x' && isxdigit(s[2]))
				*base = 16;
			else
				*base = 8;
		} else
			*base = 10;
	}
	if (*base == 16 && s[0] == '0' && _tolower(s[1]) == 'x')
		s += 2;
	return s;
}

/*
 * Convert non-negative integer string representation in explicitly given radix
 * to an integer.
 * Return number of characters consumed maybe or-ed with overflow bit.
 * If overflow occurs, result integer (incorrect) is still returned.
 *
 * Don't you dare use this function.
 */
unsigned int _parse_integer(const char *s, unsigned int base, unsigned long long *p)
{
	unsigned long long res;
	unsigned int rv;

	res = 0;
	rv = 0;
	while (1) {
		unsigned int c = *s;
		unsigned int lc = c | 0x20; /* don't tolower() this line */
		unsigned int val;

		if ('0' <= c && c <= '9')
			val = c - '0';
		else if ('a' <= lc && lc <= 'f')
			val = lc - 'a' + 10;
		else
			break;

		if (val >= base)
			break;
		/*
		 * Check for overflow only if we are within range of
		 * it in the max base we support (16)
		 */
		if (unlikely(res & (~0ull << 60))) {
			if (res > div_u64(ULLONG_MAX - val, base))
				rv |= KSTRTOX_OVERFLOW;
		}
		res = res * base + val;
		rv++;
		s++;
	}
	*p = res;
	return rv;
}

static int _kstrtoull(const char *s, unsigned int base, unsigned long long *res)
{
	unsigned long long _res;
	unsigned int rv;

	s = _parse_integer_fixup_radix(s, &base);
	rv = _parse_integer(s, base, &_res);
	if (rv & KSTRTOX_OVERFLOW)
		return -ERANGE;
	if (rv == 0)
		return -EINVAL;
	s += rv;
	if (*s == '\n')
		s++;
	if (*s)
		return -EINVAL;
	*res = _res;
	return 0;
}

/**
 * kstrtoull - convert a string to an unsigned long long
 * @s: The start of the string. The string must be null-terminated, and may also
 *  include a single newline before its terminating null. The first character
 *  may also be a plus sign, but not a minus sign.
 * @base: The number base to use. The maximum supported base is 16. If base is
 *  given as 0, then the base of the string is automatically detected with the
 *  conventional semantics - If it begins with 0x the number will be parsed as a
 *  hexadecimal (case insensitive), if it otherwise begins with 0, it will be
 *  parsed as an octal number. Otherwise it will be parsed as a decimal.
 * @res: Where to write the result of the conversion on success.
 *
 * Returns 0 on success, -ERANGE on overflow and -EINVAL on parsing error.
 * Preferred over simple_strtoull(). Return code must be checked.
 */
int kstrtoull(const char *s, unsigned int base, unsigned long long *res)
{
	if (s[0] == '+')
		s++;
	return _kstrtoull(s, base, res);
}
EXPORT_SYMBOL(kstrtoull);

/**
 * kstrtoll - convert a string to a long long
 * @s: The start of the string. The string must be null-terminated, and may also
 *  include a single newline before its terminating null. The first character
 *  may also be a plus sign or a minus sign.
 * @base: The number base to use. The maximum supported base is 16. If base is
 *  given as 0, then the base of the string is automatically detected with the
 *  conventional semantics - If it begins with 0x the number will be parsed as a
 *  hexadecimal (case insensitive), if it otherwise begins with 0, it will be
 *  parsed as an octal number. Otherwise it will be parsed as a decimal.
 * @res: Where to write the result of the conversion on success.
 *
 * Returns 0 on success, -ERANGE on overflow and -EINVAL on parsing error.
 * Preferred over simple_strtoll(). Return code must be checked.
 */
int kstrtoll(const char *s, unsigned int base, long long *res)
{
	unsigned long long tmp;
	int rv;

	if (s[0] == '-') {
		rv = _kstrtoull(s + 1, base, &tmp);
		if (rv < 0)
			return rv;
		if ((long long)-tmp > 0)
			return -ERANGE;
		*res = -tmp;
	} else {
		rv = kstrtoull(s, base, &tmp);
		if (rv < 0)
			return rv;
		if ((long long)tmp < 0)
			return -ERANGE;
		*res = tmp;
	}
	return 0;
}
EXPORT_SYMBOL(kstrtoll);

/* Internal, do not use. */
int _kstrtoul(const char *s, unsigned int base, unsigned long *res)
{
	unsigned long long tmp;
	int rv;

	rv = kstrtoull(s, base, &tmp);
	if (rv < 0)
		return rv;
	if (tmp != (unsigned long)tmp)
		return -ERANGE;
	*res = tmp;
	return 0;
}
EXPORT_SYMBOL(_kstrtoul);

/* Internal, do not use. */
int _kstrtol(const char *s, unsigned int base, long *res)
{
	long long tmp;
	int rv;

	rv = kstrtoll(s, base, &tmp);
	if (rv < 0)
		return rv;
	if (tmp != (long)tmp)
		return -ERANGE;
	*res = tmp;
	return 0;
}
EXPORT_SYMBOL(_kstrtol);

/**
 * kstrtouint - convert a string to an unsigned int
 * @s: The start of the string. The string must be null-terminated, and may also
 *  include a single newline before its terminating null. The first character
 *  may also be a plus sign, but not a minus sign.
 * @base: The number base to use. The maximum supported base is 16. If base is
 *  given as 0, then the base of the string is automatically detected with the
 *  conventional semantics - If it begins with 0x the number will be parsed as a
 *  hexadecimal (case insensitive), if it otherwise begins with 0, it will be
 *  parsed as an octal number. Otherwise it will be parsed as a decimal.
 * @res: Where to write the result of the conversion on success.
 *
 * Returns 0 on success, -ERANGE on overflow and -EINVAL on parsing error.
 * Preferred over simple_strtoul(). Return code must be checked.
 */
int kstrtouint(const char *s, unsigned int base, unsigned int *res)
{
	unsigned long long tmp;
	int rv;

	rv = kstrtoull(s, base, &tmp);
	if (rv < 0)
		return rv;
	if (tmp != (unsigned int)tmp)
		return -ERANGE;
	*res = tmp;
	return 0;
}
EXPORT_SYMBOL(kstrtouint);

/**
 * kstrtoint - convert a string to an int
 * @s: The start of the string. The string must be null-terminated, and may also
 *  include a single newline before its terminating null. The first character
 *  may also be a plus sign or a minus sign.
 * @base: The number base to use. The maximum supported base is 16. If base is
 *  given as 0, then the base of the string is automatically detected with the
 *  conventional semantics - If it begins with 0x the number will be parsed as a
 *  hexadecimal (case insensitive), if it otherwise begins with 0, it will be
 *  parsed as an octal number. Otherwise it will be parsed as a decimal.
 * @res: Where to write the result of the conversion on success.
 *
 * Returns 0 on success, -ERANGE on overflow and -EINVAL on parsing error.
 * Preferred over simple_strtol(). Return code must be checked.
 */
int kstrtoint(const char *s, unsigned int base, int *res)
{
	long long tmp;
	int rv;

	rv = kstrtoll(s, base, &tmp);
	if (rv < 0)
		return rv;
	if (tmp != (int)tmp)
		return -ERANGE;
	*res = tmp;
	return 0;
}
EXPORT_SYMBOL(kstrtoint);

int kstrtou16(const char *s, unsigned int base, u16 *res)
{
	unsigned long long tmp;
	int rv;

	rv = kstrtoull(s, base, &tmp);
	if (rv < 0)
		return rv;
	if (tmp != (u16)tmp)
		return -ERANGE;
	*res = tmp;
	return 0;
}
EXPORT_SYMBOL(kstrtou16);

int kstrtos16(const char *s, unsigned int base, s16 *res)
{
	long long tmp;
	int rv;

	rv = kstrtoll(s, base, &tmp);
	if (rv < 0)
		return rv;
	if (tmp != (s16)tmp)
		return -ERANGE;
	*res = tmp;
	return 0;
}
EXPORT_SYMBOL(kstrtos16);

int kstrtou8(const char *s, unsigned int base, u8 *res)
{
	unsigned long long tmp;
	int rv;

	rv = kstrtoull(s, base, &tmp);
	if (rv < 0)
		return rv;
	if (tmp != (u8)tmp)
		return -ERANGE;
	*res = tmp;
	return 0;
}
EXPORT_SYMBOL(kstrtou8);

int kstrtos8(const char *s, unsigned int base, s8 *res)
{
	long long tmp;
	int rv;

	rv = kstrtoll(s, base, &tmp);
	if (rv < 0)
		return rv;
	if (tmp != (s8)tmp)
		return -ERANGE;
	*res = tmp;
	return 0;
}
EXPORT_SYMBOL(kstrtos8);

/**
 * kstrtobool - convert common user inputs into boolean values
 * @s: input string
 * @res: result
 *
 * This routine returns 0 iff the first character is one of 'Yy1Nn0', or
 * [oO][NnFf] for "on" and "off". Otherwise it will return -EINVAL.  Value
 * pointed to by res is updated upon finding a match.
 */
int kstrtobool(const char *s, bool *res)
{
	if (!s)
		return -EINVAL;

	switch (s[0]) {
	case 'y':
	case 'Y':
	case '1':
		*res = true;
		return 0;
	case 'n':
	case 'N':
	case '0':
		*res = false;
		return 0;
	case 'o':
	case 'O':
		switch (s[1]) {
		case 'n':
		case 'N':
			*res = true;
			return 0;
		case 'f':
		case 'F':
			*res = false;
			return 0;
		default:
			break;
		}
	default:
		break;
	}

	return -EINVAL;
}
EXPORT_SYMBOL(kstrtobool);

/*
 * Since "base" would be a nonsense argument, this open-codes the
 * _from_user helper instead of using the helper macro below.
 */
int kstrtobool_from_user(const char __user *s, size_t count, bool *res)
{
	/* Longest string needed to differentiate, newline, terminator */
	char buf[4];

	count = min(count, sizeof(buf) - 1);
	if (copy_from_user(buf, s, count))
		return -EFAULT;
	buf[count] = '\0';
	return kstrtobool(buf, res);
}
EXPORT_SYMBOL(kstrtobool_from_user);

#define kstrto_from_user(f, g, type)					\
int f(const char __user *s, size_t count, unsigned int base, type *res)	\
{									\
	/* sign, base 2 representation, newline, terminator */		\
	char buf[1 + sizeof(type) * 8 + 1 + 1];				\
									\
	count = min(count, sizeof(buf) - 1);				\
	if (copy_from_user(buf, s, count))				\
		return -EFAULT;						\
	buf[count] = '\0';						\
	return g(buf, base, res);					\
}									\
EXPORT_SYMBOL(f)

kstrto_from_user(kstrtoull_from_user,	kstrtoull,	unsigned long long);
kstrto_from_user(kstrtoll_from_user,	kstrtoll,	long long);
kstrto_from_user(kstrtoul_from_user,	kstrtoul,	unsigned long);
kstrto_from_user(kstrtol_from_user,	kstrtol,	long);
kstrto_from_user(kstrtouint_from_user,	kstrtouint,	unsigned int);
kstrto_from_user(kstrtoint_from_user,	kstrtoint,	int);
kstrto_from_user(kstrtou16_from_user,	kstrtou16,	u16);
kstrto_from_user(kstrtos16_from_user,	kstrtos16,	s16);
kstrto_from_user(kstrtou8_from_user,	kstrtou8,	u8);
kstrto_from_user(kstrtos8_from_user,	kstrtos8,	s8);
Commit	Line	Data
b2441318	1	// SPDX-License-Identifier: GPL-2.0
33ee3b2e AD	2	/*
	3	* Convert integer string representation to an integer.
	4	* If an integer doesn't fit into specified type, -E is returned.
	5	*
	6	* Integer starts with optional sign.
	7	* kstrtou*() functions do not accept sign "-".
	8	*
	9	* Radix 0 means autodetection: leading "0x" implies radix 16,
	10	* leading "0" implies radix 8, otherwise radix is 10.
	11	* Autodetection hints work after optional sign, but not before.
	12	*
	13	* If -E is returned, result is not touched.
	14	*/
	15	#include <linux/ctype.h>
	16	#include <linux/errno.h>
	17	#include <linux/kernel.h>
	18	#include <linux/math64.h>
8bc3bcc9	19	#include <linux/export.h>
33ee3b2e	20	#include <linux/types.h>
7c0f6ba6	21	#include <linux/uaccess.h>
1dff46d6	22	#include "kstrtox.h"
33ee3b2e	23
1dff46d6	24	const char _parse_integer_fixup_radix(const char s, unsigned int *base)
33ee3b2e	25	{
1dff46d6	26	if (*base == 0) {
33ee3b2e AD	27	if (s[0] == '0') {
33ee3b2e AD	28	if (_tolower(s[1]) == 'x' && isxdigit(s[2]))
1dff46d6	29	*base = 16;
33ee3b2e	30	else
1dff46d6	31	*base = 8;
33ee3b2e	32	} else
1dff46d6	33	*base = 10;
33ee3b2e	34	}
1dff46d6	35	if (*base == 16 && s[0] == '0' && _tolower(s[1]) == 'x')
33ee3b2e	36	s += 2;
1dff46d6 AD	37	return s;
	38	}
	39
	40	/*
	41	* Convert non-negative integer string representation in explicitly given radix
	42	* to an integer.
	43	* Return number of characters consumed maybe or-ed with overflow bit.
	44	* If overflow occurs, result integer (incorrect) is still returned.
	45	*
	46	* Don't you dare use this function.
	47	*/
690d137f	48	unsigned int _parse_integer(const char s, unsigned int base, unsigned long long p)
1dff46d6	49	{
690d137f	50	unsigned long long res;
1dff46d6	51	unsigned int rv;
33ee3b2e	52
690d137f	53	res = 0;
1dff46d6	54	rv = 0;
512750ef	55	while (1) {
be5f3c77 AD	56	unsigned int c = *s;
be5f3c77 AD	57	unsigned int lc = c \| 0x20; /* don't tolower() this line */
33ee3b2e AD	58	unsigned int val;
33ee3b2e AD	59
be5f3c77 AD	60	if ('0' <= c && c <= '9')
	61	val = c - '0';
	62	else if ('a' <= lc && lc <= 'f')
	63	val = lc - 'a' + 10;
78be959e	64	else
1dff46d6	65	break;
33ee3b2e AD	66
33ee3b2e AD	67	if (val >= base)
1dff46d6	68	break;
690d137f DH	69	/*
	70	* Check for overflow only if we are within range of
	71	* it in the max base we support (16)
	72	*/
	73	if (unlikely(res & (~0ull << 60))) {
	74	if (res > div_u64(ULLONG_MAX - val, base))
8cfd56d4	75	rv \|= KSTRTOX_OVERFLOW;
690d137f DH	76	}
690d137f DH	77	res = res * base + val;
1dff46d6	78	rv++;
33ee3b2e AD	79	s++;
33ee3b2e AD	80	}
690d137f	81	*p = res;
1dff46d6 AD	82	return rv;
	83	}
	84
	85	static int _kstrtoull(const char s, unsigned int base, unsigned long long res)
	86	{
	87	unsigned long long _res;
	88	unsigned int rv;
	89
	90	s = _parse_integer_fixup_radix(s, &base);
	91	rv = _parse_integer(s, base, &_res);
	92	if (rv & KSTRTOX_OVERFLOW)
	93	return -ERANGE;
1dff46d6 AD	94	if (rv == 0)
	95	return -EINVAL;
	96	s += rv;
	97	if (*s == '\n')
	98	s++;
	99	if (*s)
33ee3b2e	100	return -EINVAL;
1dff46d6	101	*res = _res;
33ee3b2e AD	102	return 0;
	103	}
	104
4c925d60 EZ	105	/**
	106	* kstrtoull - convert a string to an unsigned long long
	107	* @s: The start of the string. The string must be null-terminated, and may also
	108	* include a single newline before its terminating null. The first character
	109	* may also be a plus sign, but not a minus sign.
	110	* @base: The number base to use. The maximum supported base is 16. If base is
	111	* given as 0, then the base of the string is automatically detected with the
	112	* conventional semantics - If it begins with 0x the number will be parsed as a
	113	* hexadecimal (case insensitive), if it otherwise begins with 0, it will be
	114	* parsed as an octal number. Otherwise it will be parsed as a decimal.
	115	* @res: Where to write the result of the conversion on success.
	116	*
	117	* Returns 0 on success, -ERANGE on overflow and -EINVAL on parsing error.
ef0f2685	118	* Preferred over simple_strtoull(). Return code must be checked.
4c925d60	119	*/
33ee3b2e AD	120	int kstrtoull(const char s, unsigned int base, unsigned long long res)
	121	{
	122	if (s[0] == '+')
	123	s++;
	124	return _kstrtoull(s, base, res);
	125	}
	126	EXPORT_SYMBOL(kstrtoull);
	127
4c925d60 EZ	128	/**
	129	* kstrtoll - convert a string to a long long
	130	* @s: The start of the string. The string must be null-terminated, and may also
	131	* include a single newline before its terminating null. The first character
	132	* may also be a plus sign or a minus sign.
	133	* @base: The number base to use. The maximum supported base is 16. If base is
	134	* given as 0, then the base of the string is automatically detected with the
	135	* conventional semantics - If it begins with 0x the number will be parsed as a
	136	* hexadecimal (case insensitive), if it otherwise begins with 0, it will be
	137	* parsed as an octal number. Otherwise it will be parsed as a decimal.
	138	* @res: Where to write the result of the conversion on success.
	139	*
	140	* Returns 0 on success, -ERANGE on overflow and -EINVAL on parsing error.
ef0f2685	141	* Preferred over simple_strtoll(). Return code must be checked.
4c925d60	142	*/
33ee3b2e AD	143	int kstrtoll(const char s, unsigned int base, long long res)
	144	{
	145	unsigned long long tmp;
	146	int rv;
	147
	148	if (s[0] == '-') {
	149	rv = _kstrtoull(s + 1, base, &tmp);
	150	if (rv < 0)
	151	return rv;
2d2e4715	152	if ((long long)-tmp > 0)
33ee3b2e AD	153	return -ERANGE;
	154	*res = -tmp;
	155	} else {
	156	rv = kstrtoull(s, base, &tmp);
	157	if (rv < 0)
	158	return rv;
	159	if ((long long)tmp < 0)
	160	return -ERANGE;
	161	*res = tmp;
	162	}
	163	return 0;
	164	}
	165	EXPORT_SYMBOL(kstrtoll);
	166
	167	/* Internal, do not use. */
	168	int _kstrtoul(const char s, unsigned int base, unsigned long res)
	169	{
	170	unsigned long long tmp;
	171	int rv;
	172
	173	rv = kstrtoull(s, base, &tmp);
	174	if (rv < 0)
	175	return rv;
048e513d	176	if (tmp != (unsigned long)tmp)
33ee3b2e AD	177	return -ERANGE;
	178	*res = tmp;
	179	return 0;
	180	}
	181	EXPORT_SYMBOL(_kstrtoul);
	182
	183	/* Internal, do not use. */
	184	int _kstrtol(const char s, unsigned int base, long res)
	185	{
	186	long long tmp;
	187	int rv;
	188
	189	rv = kstrtoll(s, base, &tmp);
	190	if (rv < 0)
	191	return rv;
048e513d	192	if (tmp != (long)tmp)
33ee3b2e AD	193	return -ERANGE;
	194	*res = tmp;
	195	return 0;
	196	}
	197	EXPORT_SYMBOL(_kstrtol);
	198
4c925d60 EZ	199	/**
	200	* kstrtouint - convert a string to an unsigned int
	201	* @s: The start of the string. The string must be null-terminated, and may also
	202	* include a single newline before its terminating null. The first character
	203	* may also be a plus sign, but not a minus sign.
	204	* @base: The number base to use. The maximum supported base is 16. If base is
	205	* given as 0, then the base of the string is automatically detected with the
	206	* conventional semantics - If it begins with 0x the number will be parsed as a
	207	* hexadecimal (case insensitive), if it otherwise begins with 0, it will be
	208	* parsed as an octal number. Otherwise it will be parsed as a decimal.
	209	* @res: Where to write the result of the conversion on success.
	210	*
	211	* Returns 0 on success, -ERANGE on overflow and -EINVAL on parsing error.
ef0f2685	212	* Preferred over simple_strtoul(). Return code must be checked.
4c925d60	213	*/
33ee3b2e AD	214	int kstrtouint(const char s, unsigned int base, unsigned int res)
	215	{
	216	unsigned long long tmp;
	217	int rv;
	218
	219	rv = kstrtoull(s, base, &tmp);
	220	if (rv < 0)
	221	return rv;
048e513d	222	if (tmp != (unsigned int)tmp)
33ee3b2e AD	223	return -ERANGE;
	224	*res = tmp;
	225	return 0;
	226	}
	227	EXPORT_SYMBOL(kstrtouint);
	228
4c925d60 EZ	229	/**
	230	* kstrtoint - convert a string to an int
	231	* @s: The start of the string. The string must be null-terminated, and may also
	232	* include a single newline before its terminating null. The first character
	233	* may also be a plus sign or a minus sign.
	234	* @base: The number base to use. The maximum supported base is 16. If base is
	235	* given as 0, then the base of the string is automatically detected with the
	236	* conventional semantics - If it begins with 0x the number will be parsed as a
	237	* hexadecimal (case insensitive), if it otherwise begins with 0, it will be
	238	* parsed as an octal number. Otherwise it will be parsed as a decimal.
	239	* @res: Where to write the result of the conversion on success.
	240	*
	241	* Returns 0 on success, -ERANGE on overflow and -EINVAL on parsing error.
ef0f2685	242	* Preferred over simple_strtol(). Return code must be checked.
4c925d60	243	*/
33ee3b2e AD	244	int kstrtoint(const char s, unsigned int base, int res)
	245	{
	246	long long tmp;
	247	int rv;
	248
	249	rv = kstrtoll(s, base, &tmp);
	250	if (rv < 0)
	251	return rv;
048e513d	252	if (tmp != (int)tmp)
33ee3b2e AD	253	return -ERANGE;
	254	*res = tmp;
	255	return 0;
	256	}
	257	EXPORT_SYMBOL(kstrtoint);
	258
	259	int kstrtou16(const char s, unsigned int base, u16 res)
	260	{
	261	unsigned long long tmp;
	262	int rv;
	263
	264	rv = kstrtoull(s, base, &tmp);
	265	if (rv < 0)
	266	return rv;
048e513d	267	if (tmp != (u16)tmp)
33ee3b2e AD	268	return -ERANGE;
	269	*res = tmp;
	270	return 0;
	271	}
	272	EXPORT_SYMBOL(kstrtou16);
	273
	274	int kstrtos16(const char s, unsigned int base, s16 res)
	275	{
	276	long long tmp;
	277	int rv;
	278
	279	rv = kstrtoll(s, base, &tmp);
	280	if (rv < 0)
	281	return rv;
048e513d	282	if (tmp != (s16)tmp)
33ee3b2e AD	283	return -ERANGE;
	284	*res = tmp;
	285	return 0;
	286	}
	287	EXPORT_SYMBOL(kstrtos16);
	288
	289	int kstrtou8(const char s, unsigned int base, u8 res)
	290	{
	291	unsigned long long tmp;
	292	int rv;
	293
	294	rv = kstrtoull(s, base, &tmp);
	295	if (rv < 0)
	296	return rv;
048e513d	297	if (tmp != (u8)tmp)
33ee3b2e AD	298	return -ERANGE;
	299	*res = tmp;
	300	return 0;
	301	}
	302	EXPORT_SYMBOL(kstrtou8);
	303
	304	int kstrtos8(const char s, unsigned int base, s8 res)
	305	{
	306	long long tmp;
	307	int rv;
	308
	309	rv = kstrtoll(s, base, &tmp);
	310	if (rv < 0)
	311	return rv;
048e513d	312	if (tmp != (s8)tmp)
33ee3b2e AD	313	return -ERANGE;
	314	*res = tmp;
	315	return 0;
	316	}
	317	EXPORT_SYMBOL(kstrtos8);
c196e32a	318
ef951599 KC	319	/**
	320	* kstrtobool - convert common user inputs into boolean values
	321	* @s: input string
	322	* @res: result
	323	*
a81a5a17 KC	324	* This routine returns 0 iff the first character is one of 'Yy1Nn0', or
	325	* [oO][NnFf] for "on" and "off". Otherwise it will return -EINVAL. Value
	326	* pointed to by res is updated upon finding a match.
ef951599 KC	327	*/
	328	int kstrtobool(const char s, bool res)
	329	{
	330	if (!s)
	331	return -EINVAL;
	332
	333	switch (s[0]) {
	334	case 'y':
	335	case 'Y':
	336	case '1':
	337	*res = true;
	338	return 0;
	339	case 'n':
	340	case 'N':
	341	case '0':
	342	*res = false;
	343	return 0;
a81a5a17 KC	344	case 'o':
	345	case 'O':
	346	switch (s[1]) {
	347	case 'n':
	348	case 'N':
	349	*res = true;
	350	return 0;
	351	case 'f':
	352	case 'F':
	353	*res = false;
	354	return 0;
	355	default:
	356	break;
	357	}
ef951599 KC	358	default:
	359	break;
	360	}
	361
	362	return -EINVAL;
	363	}
	364	EXPORT_SYMBOL(kstrtobool);
	365
	366	/*
	367	* Since "base" would be a nonsense argument, this open-codes the
	368	* _from_user helper instead of using the helper macro below.
	369	*/
	370	int kstrtobool_from_user(const char __user s, size_t count, bool res)
	371	{
	372	/* Longest string needed to differentiate, newline, terminator */
	373	char buf[4];
	374
	375	count = min(count, sizeof(buf) - 1);
	376	if (copy_from_user(buf, s, count))
	377	return -EFAULT;
	378	buf[count] = '\0';
	379	return kstrtobool(buf, res);
	380	}
	381	EXPORT_SYMBOL(kstrtobool_from_user);
	382
c196e32a AD	383	#define kstrto_from_user(f, g, type) \
	384	int f(const char __user s, size_t count, unsigned int base, type res) \
	385	{ \
	386	/* sign, base 2 representation, newline, terminator */ \
	387	char buf[1 + sizeof(type) * 8 + 1 + 1]; \
	388	\
	389	count = min(count, sizeof(buf) - 1); \
	390	if (copy_from_user(buf, s, count)) \
	391	return -EFAULT; \
	392	buf[count] = '\0'; \
	393	return g(buf, base, res); \
	394	} \
	395	EXPORT_SYMBOL(f)
	396
	397	kstrto_from_user(kstrtoull_from_user, kstrtoull, unsigned long long);
	398	kstrto_from_user(kstrtoll_from_user, kstrtoll, long long);
	399	kstrto_from_user(kstrtoul_from_user, kstrtoul, unsigned long);
	400	kstrto_from_user(kstrtol_from_user, kstrtol, long);
	401	kstrto_from_user(kstrtouint_from_user, kstrtouint, unsigned int);
	402	kstrto_from_user(kstrtoint_from_user, kstrtoint, int);
	403	kstrto_from_user(kstrtou16_from_user, kstrtou16, u16);
	404	kstrto_from_user(kstrtos16_from_user, kstrtos16, s16);
	405	kstrto_from_user(kstrtou8_from_user, kstrtou8, u8);
	406	kstrto_from_user(kstrtos8_from_user, kstrtos8, s8);