[linux.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.
 * Used as a replacement for the obsolete 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.
 * Used as a replacement for the obsolete simple_strtoull. 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.
 * Used as a replacement for the obsolete simple_strtoull. 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.
 * Used as a replacement for the obsolete simple_strtoull. 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.
	118	* Used as a replacement for the obsolete simple_strtoull. Return code must
	119	* be checked.
	120	*/
33ee3b2e AD	121	int kstrtoull(const char s, unsigned int base, unsigned long long res)
	122	{
	123	if (s[0] == '+')
	124	s++;
	125	return _kstrtoull(s, base, res);
	126	}
	127	EXPORT_SYMBOL(kstrtoull);
	128
4c925d60 EZ	129	/**
	130	* kstrtoll - convert a string to a long long
	131	* @s: The start of the string. The string must be null-terminated, and may also
	132	* include a single newline before its terminating null. The first character
	133	* may also be a plus sign or a minus sign.
	134	* @base: The number base to use. The maximum supported base is 16. If base is
	135	* given as 0, then the base of the string is automatically detected with the
	136	* conventional semantics - If it begins with 0x the number will be parsed as a
	137	* hexadecimal (case insensitive), if it otherwise begins with 0, it will be
	138	* parsed as an octal number. Otherwise it will be parsed as a decimal.
	139	* @res: Where to write the result of the conversion on success.
	140	*
	141	* Returns 0 on success, -ERANGE on overflow and -EINVAL on parsing error.
	142	* Used as a replacement for the obsolete simple_strtoull. Return code must
	143	* be checked.
	144	*/
33ee3b2e AD	145	int kstrtoll(const char s, unsigned int base, long long res)
	146	{
	147	unsigned long long tmp;
	148	int rv;
	149
	150	if (s[0] == '-') {
	151	rv = _kstrtoull(s + 1, base, &tmp);
	152	if (rv < 0)
	153	return rv;
2d2e4715	154	if ((long long)-tmp > 0)
33ee3b2e AD	155	return -ERANGE;
	156	*res = -tmp;
	157	} else {
	158	rv = kstrtoull(s, base, &tmp);
	159	if (rv < 0)
	160	return rv;
	161	if ((long long)tmp < 0)
	162	return -ERANGE;
	163	*res = tmp;
	164	}
	165	return 0;
	166	}
	167	EXPORT_SYMBOL(kstrtoll);
	168
	169	/* Internal, do not use. */
	170	int _kstrtoul(const char s, unsigned int base, unsigned long res)
	171	{
	172	unsigned long long tmp;
	173	int rv;
	174
	175	rv = kstrtoull(s, base, &tmp);
	176	if (rv < 0)
	177	return rv;
048e513d	178	if (tmp != (unsigned long)tmp)
33ee3b2e AD	179	return -ERANGE;
	180	*res = tmp;
	181	return 0;
	182	}
	183	EXPORT_SYMBOL(_kstrtoul);
	184
	185	/* Internal, do not use. */
	186	int _kstrtol(const char s, unsigned int base, long res)
	187	{
	188	long long tmp;
	189	int rv;
	190
	191	rv = kstrtoll(s, base, &tmp);
	192	if (rv < 0)
	193	return rv;
048e513d	194	if (tmp != (long)tmp)
33ee3b2e AD	195	return -ERANGE;
	196	*res = tmp;
	197	return 0;
	198	}
	199	EXPORT_SYMBOL(_kstrtol);
	200
4c925d60 EZ	201	/**
	202	* kstrtouint - convert a string to an unsigned int
	203	* @s: The start of the string. The string must be null-terminated, and may also
	204	* include a single newline before its terminating null. The first character
	205	* may also be a plus sign, but not a minus sign.
	206	* @base: The number base to use. The maximum supported base is 16. If base is
	207	* given as 0, then the base of the string is automatically detected with the
	208	* conventional semantics - If it begins with 0x the number will be parsed as a
	209	* hexadecimal (case insensitive), if it otherwise begins with 0, it will be
	210	* parsed as an octal number. Otherwise it will be parsed as a decimal.
	211	* @res: Where to write the result of the conversion on success.
	212	*
	213	* Returns 0 on success, -ERANGE on overflow and -EINVAL on parsing error.
	214	* Used as a replacement for the obsolete simple_strtoull. Return code must
	215	* be checked.
	216	*/
33ee3b2e AD	217	int kstrtouint(const char s, unsigned int base, unsigned int res)
	218	{
	219	unsigned long long tmp;
	220	int rv;
	221
	222	rv = kstrtoull(s, base, &tmp);
	223	if (rv < 0)
	224	return rv;
048e513d	225	if (tmp != (unsigned int)tmp)
33ee3b2e AD	226	return -ERANGE;
	227	*res = tmp;
	228	return 0;
	229	}
	230	EXPORT_SYMBOL(kstrtouint);
	231
4c925d60 EZ	232	/**
	233	* kstrtoint - convert a string to an int
	234	* @s: The start of the string. The string must be null-terminated, and may also
	235	* include a single newline before its terminating null. The first character
	236	* may also be a plus sign or a minus sign.
	237	* @base: The number base to use. The maximum supported base is 16. If base is
	238	* given as 0, then the base of the string is automatically detected with the
	239	* conventional semantics - If it begins with 0x the number will be parsed as a
	240	* hexadecimal (case insensitive), if it otherwise begins with 0, it will be
	241	* parsed as an octal number. Otherwise it will be parsed as a decimal.
	242	* @res: Where to write the result of the conversion on success.
	243	*
	244	* Returns 0 on success, -ERANGE on overflow and -EINVAL on parsing error.
	245	* Used as a replacement for the obsolete simple_strtoull. Return code must
	246	* be checked.
	247	*/
33ee3b2e AD	248	int kstrtoint(const char s, unsigned int base, int res)
	249	{
	250	long long tmp;
	251	int rv;
	252
	253	rv = kstrtoll(s, base, &tmp);
	254	if (rv < 0)
	255	return rv;
048e513d	256	if (tmp != (int)tmp)
33ee3b2e AD	257	return -ERANGE;
	258	*res = tmp;
	259	return 0;
	260	}
	261	EXPORT_SYMBOL(kstrtoint);
	262
	263	int kstrtou16(const char s, unsigned int base, u16 res)
	264	{
	265	unsigned long long tmp;
	266	int rv;
	267
	268	rv = kstrtoull(s, base, &tmp);
	269	if (rv < 0)
	270	return rv;
048e513d	271	if (tmp != (u16)tmp)
33ee3b2e AD	272	return -ERANGE;
	273	*res = tmp;
	274	return 0;
	275	}
	276	EXPORT_SYMBOL(kstrtou16);
	277
	278	int kstrtos16(const char s, unsigned int base, s16 res)
	279	{
	280	long long tmp;
	281	int rv;
	282
	283	rv = kstrtoll(s, base, &tmp);
	284	if (rv < 0)
	285	return rv;
048e513d	286	if (tmp != (s16)tmp)
33ee3b2e AD	287	return -ERANGE;
	288	*res = tmp;
	289	return 0;
	290	}
	291	EXPORT_SYMBOL(kstrtos16);
	292
	293	int kstrtou8(const char s, unsigned int base, u8 res)
	294	{
	295	unsigned long long tmp;
	296	int rv;
	297
	298	rv = kstrtoull(s, base, &tmp);
	299	if (rv < 0)
	300	return rv;
048e513d	301	if (tmp != (u8)tmp)
33ee3b2e AD	302	return -ERANGE;
	303	*res = tmp;
	304	return 0;
	305	}
	306	EXPORT_SYMBOL(kstrtou8);
	307
	308	int kstrtos8(const char s, unsigned int base, s8 res)
	309	{
	310	long long tmp;
	311	int rv;
	312
	313	rv = kstrtoll(s, base, &tmp);
	314	if (rv < 0)
	315	return rv;
048e513d	316	if (tmp != (s8)tmp)
33ee3b2e AD	317	return -ERANGE;
	318	*res = tmp;
	319	return 0;
	320	}
	321	EXPORT_SYMBOL(kstrtos8);
c196e32a	322
ef951599 KC	323	/**
	324	* kstrtobool - convert common user inputs into boolean values
	325	* @s: input string
	326	* @res: result
	327	*
a81a5a17 KC	328	* This routine returns 0 iff the first character is one of 'Yy1Nn0', or
	329	* [oO][NnFf] for "on" and "off". Otherwise it will return -EINVAL. Value
	330	* pointed to by res is updated upon finding a match.
ef951599 KC	331	*/
	332	int kstrtobool(const char s, bool res)
	333	{
	334	if (!s)
	335	return -EINVAL;
	336
	337	switch (s[0]) {
	338	case 'y':
	339	case 'Y':
	340	case '1':
	341	*res = true;
	342	return 0;
	343	case 'n':
	344	case 'N':
	345	case '0':
	346	*res = false;
	347	return 0;
a81a5a17 KC	348	case 'o':
	349	case 'O':
	350	switch (s[1]) {
	351	case 'n':
	352	case 'N':
	353	*res = true;
	354	return 0;
	355	case 'f':
	356	case 'F':
	357	*res = false;
	358	return 0;
	359	default:
	360	break;
	361	}
ef951599 KC	362	default:
	363	break;
	364	}
	365
	366	return -EINVAL;
	367	}
	368	EXPORT_SYMBOL(kstrtobool);
	369
	370	/*
	371	* Since "base" would be a nonsense argument, this open-codes the
	372	* _from_user helper instead of using the helper macro below.
	373	*/
	374	int kstrtobool_from_user(const char __user s, size_t count, bool res)
	375	{
	376	/* Longest string needed to differentiate, newline, terminator */
	377	char buf[4];
	378
	379	count = min(count, sizeof(buf) - 1);
	380	if (copy_from_user(buf, s, count))
	381	return -EFAULT;
	382	buf[count] = '\0';
	383	return kstrtobool(buf, res);
	384	}
	385	EXPORT_SYMBOL(kstrtobool_from_user);
	386
c196e32a AD	387	#define kstrto_from_user(f, g, type) \
	388	int f(const char __user s, size_t count, unsigned int base, type res) \
	389	{ \
	390	/* sign, base 2 representation, newline, terminator */ \
	391	char buf[1 + sizeof(type) * 8 + 1 + 1]; \
	392	\
	393	count = min(count, sizeof(buf) - 1); \
	394	if (copy_from_user(buf, s, count)) \
	395	return -EFAULT; \
	396	buf[count] = '\0'; \
	397	return g(buf, base, res); \
	398	} \
	399	EXPORT_SYMBOL(f)
	400
	401	kstrto_from_user(kstrtoull_from_user, kstrtoull, unsigned long long);
	402	kstrto_from_user(kstrtoll_from_user, kstrtoll, long long);
	403	kstrto_from_user(kstrtoul_from_user, kstrtoul, unsigned long);
	404	kstrto_from_user(kstrtol_from_user, kstrtol, long);
	405	kstrto_from_user(kstrtouint_from_user, kstrtouint, unsigned int);
	406	kstrto_from_user(kstrtoint_from_user, kstrtoint, int);
	407	kstrto_from_user(kstrtou16_from_user, kstrtou16, u16);
	408	kstrto_from_user(kstrtos16_from_user, kstrtos16, s16);
	409	kstrto_from_user(kstrtou8_from_user, kstrtou8, u8);
	410	kstrto_from_user(kstrtos8_from_user, kstrtos8, s8);