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

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