forked from mirrors/linux
		
	We already use _tolower() in other places, so convert the one which open codes it. Link: https://lkml.kernel.org/r/20230817145919.543251-1-andriy.shevchenko@linux.intel.com Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
		
			
				
	
	
		
			431 lines
		
	
	
	
		
			11 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			431 lines
		
	
	
	
		
			11 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
// SPDX-License-Identifier: GPL-2.0
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/*
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 * Convert integer string representation to an integer.
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 * If an integer doesn't fit into specified type, -E is returned.
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 *
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 * Integer starts with optional sign.
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 * kstrtou*() functions do not accept sign "-".
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 *
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 * Radix 0 means autodetection: leading "0x" implies radix 16,
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 * leading "0" implies radix 8, otherwise radix is 10.
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 * Autodetection hints work after optional sign, but not before.
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 *
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 * If -E is returned, result is not touched.
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 */
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#include <linux/ctype.h>
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#include <linux/errno.h>
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#include <linux/export.h>
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#include <linux/kstrtox.h>
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#include <linux/math64.h>
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#include <linux/types.h>
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#include <linux/uaccess.h>
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#include "kstrtox.h"
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noinline
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const char *_parse_integer_fixup_radix(const char *s, unsigned int *base)
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{
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	if (*base == 0) {
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		if (s[0] == '0') {
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			if (_tolower(s[1]) == 'x' && isxdigit(s[2]))
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				*base = 16;
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			else
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				*base = 8;
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		} else
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			*base = 10;
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	}
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	if (*base == 16 && s[0] == '0' && _tolower(s[1]) == 'x')
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		s += 2;
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	return s;
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}
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/*
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 * Convert non-negative integer string representation in explicitly given radix
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 * to an integer. A maximum of max_chars characters will be converted.
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 *
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 * Return number of characters consumed maybe or-ed with overflow bit.
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 * If overflow occurs, result integer (incorrect) is still returned.
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 *
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 * Don't you dare use this function.
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 */
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noinline
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unsigned int _parse_integer_limit(const char *s, unsigned int base, unsigned long long *p,
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				  size_t max_chars)
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{
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	unsigned long long res;
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	unsigned int rv;
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	res = 0;
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	rv = 0;
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	while (max_chars--) {
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		unsigned int c = *s;
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		unsigned int lc = _tolower(c);
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		unsigned int val;
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		if ('0' <= c && c <= '9')
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			val = c - '0';
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		else if ('a' <= lc && lc <= 'f')
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			val = lc - 'a' + 10;
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		else
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			break;
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		if (val >= base)
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			break;
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		/*
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		 * Check for overflow only if we are within range of
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		 * it in the max base we support (16)
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		 */
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		if (unlikely(res & (~0ull << 60))) {
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			if (res > div_u64(ULLONG_MAX - val, base))
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				rv |= KSTRTOX_OVERFLOW;
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		}
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		res = res * base + val;
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		rv++;
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		s++;
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	}
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	*p = res;
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	return rv;
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}
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noinline
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unsigned int _parse_integer(const char *s, unsigned int base, unsigned long long *p)
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{
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	return _parse_integer_limit(s, base, p, INT_MAX);
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}
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static int _kstrtoull(const char *s, unsigned int base, unsigned long long *res)
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{
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	unsigned long long _res;
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	unsigned int rv;
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	s = _parse_integer_fixup_radix(s, &base);
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	rv = _parse_integer(s, base, &_res);
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	if (rv & KSTRTOX_OVERFLOW)
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		return -ERANGE;
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	if (rv == 0)
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		return -EINVAL;
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	s += rv;
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	if (*s == '\n')
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		s++;
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	if (*s)
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		return -EINVAL;
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	*res = _res;
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	return 0;
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}
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/**
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 * kstrtoull - convert a string to an unsigned long long
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 * @s: The start of the string. The string must be null-terminated, and may also
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 *  include a single newline before its terminating null. The first character
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 *  may also be a plus sign, but not a minus sign.
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 * @base: The number base to use. The maximum supported base is 16. If base is
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 *  given as 0, then the base of the string is automatically detected with the
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 *  conventional semantics - If it begins with 0x the number will be parsed as a
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 *  hexadecimal (case insensitive), if it otherwise begins with 0, it will be
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 *  parsed as an octal number. Otherwise it will be parsed as a decimal.
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 * @res: Where to write the result of the conversion on success.
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 *
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 * Returns 0 on success, -ERANGE on overflow and -EINVAL on parsing error.
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 * Preferred over simple_strtoull(). Return code must be checked.
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 */
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noinline
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int kstrtoull(const char *s, unsigned int base, unsigned long long *res)
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{
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	if (s[0] == '+')
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		s++;
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	return _kstrtoull(s, base, res);
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}
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EXPORT_SYMBOL(kstrtoull);
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/**
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 * kstrtoll - convert a string to a long long
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 * @s: The start of the string. The string must be null-terminated, and may also
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 *  include a single newline before its terminating null. The first character
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 *  may also be a plus sign or a minus sign.
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 * @base: The number base to use. The maximum supported base is 16. If base is
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 *  given as 0, then the base of the string is automatically detected with the
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 *  conventional semantics - If it begins with 0x the number will be parsed as a
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 *  hexadecimal (case insensitive), if it otherwise begins with 0, it will be
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 *  parsed as an octal number. Otherwise it will be parsed as a decimal.
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 * @res: Where to write the result of the conversion on success.
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 *
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 * Returns 0 on success, -ERANGE on overflow and -EINVAL on parsing error.
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 * Preferred over simple_strtoll(). Return code must be checked.
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 */
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noinline
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int kstrtoll(const char *s, unsigned int base, long long *res)
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{
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	unsigned long long tmp;
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	int rv;
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	if (s[0] == '-') {
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		rv = _kstrtoull(s + 1, base, &tmp);
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		if (rv < 0)
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			return rv;
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		if ((long long)-tmp > 0)
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			return -ERANGE;
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		*res = -tmp;
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	} else {
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		rv = kstrtoull(s, base, &tmp);
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		if (rv < 0)
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			return rv;
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		if ((long long)tmp < 0)
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			return -ERANGE;
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		*res = tmp;
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	}
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	return 0;
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}
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EXPORT_SYMBOL(kstrtoll);
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/* Internal, do not use. */
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int _kstrtoul(const char *s, unsigned int base, unsigned long *res)
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{
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	unsigned long long tmp;
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	int rv;
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	rv = kstrtoull(s, base, &tmp);
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	if (rv < 0)
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		return rv;
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	if (tmp != (unsigned long)tmp)
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		return -ERANGE;
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	*res = tmp;
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	return 0;
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}
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EXPORT_SYMBOL(_kstrtoul);
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/* Internal, do not use. */
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int _kstrtol(const char *s, unsigned int base, long *res)
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{
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	long long tmp;
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	int rv;
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	rv = kstrtoll(s, base, &tmp);
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	if (rv < 0)
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		return rv;
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	if (tmp != (long)tmp)
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		return -ERANGE;
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	*res = tmp;
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	return 0;
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}
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EXPORT_SYMBOL(_kstrtol);
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/**
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 * kstrtouint - convert a string to an unsigned int
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 * @s: The start of the string. The string must be null-terminated, and may also
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 *  include a single newline before its terminating null. The first character
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 *  may also be a plus sign, but not a minus sign.
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 * @base: The number base to use. The maximum supported base is 16. If base is
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 *  given as 0, then the base of the string is automatically detected with the
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 *  conventional semantics - If it begins with 0x the number will be parsed as a
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 *  hexadecimal (case insensitive), if it otherwise begins with 0, it will be
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 *  parsed as an octal number. Otherwise it will be parsed as a decimal.
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 * @res: Where to write the result of the conversion on success.
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 *
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 * Returns 0 on success, -ERANGE on overflow and -EINVAL on parsing error.
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 * Preferred over simple_strtoul(). Return code must be checked.
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 */
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noinline
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int kstrtouint(const char *s, unsigned int base, unsigned int *res)
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{
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	unsigned long long tmp;
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	int rv;
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	rv = kstrtoull(s, base, &tmp);
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	if (rv < 0)
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		return rv;
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	if (tmp != (unsigned int)tmp)
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		return -ERANGE;
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	*res = tmp;
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	return 0;
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}
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EXPORT_SYMBOL(kstrtouint);
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/**
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 * kstrtoint - convert a string to an int
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 * @s: The start of the string. The string must be null-terminated, and may also
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 *  include a single newline before its terminating null. The first character
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 *  may also be a plus sign or a minus sign.
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 * @base: The number base to use. The maximum supported base is 16. If base is
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 *  given as 0, then the base of the string is automatically detected with the
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 *  conventional semantics - If it begins with 0x the number will be parsed as a
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 *  hexadecimal (case insensitive), if it otherwise begins with 0, it will be
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 *  parsed as an octal number. Otherwise it will be parsed as a decimal.
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 * @res: Where to write the result of the conversion on success.
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 *
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 * Returns 0 on success, -ERANGE on overflow and -EINVAL on parsing error.
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 * Preferred over simple_strtol(). Return code must be checked.
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 */
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noinline
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int kstrtoint(const char *s, unsigned int base, int *res)
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{
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	long long tmp;
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	int rv;
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	rv = kstrtoll(s, base, &tmp);
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	if (rv < 0)
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		return rv;
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	if (tmp != (int)tmp)
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		return -ERANGE;
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	*res = tmp;
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	return 0;
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}
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EXPORT_SYMBOL(kstrtoint);
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noinline
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int kstrtou16(const char *s, unsigned int base, u16 *res)
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{
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	unsigned long long tmp;
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	int rv;
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	rv = kstrtoull(s, base, &tmp);
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	if (rv < 0)
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		return rv;
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	if (tmp != (u16)tmp)
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		return -ERANGE;
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	*res = tmp;
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	return 0;
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}
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EXPORT_SYMBOL(kstrtou16);
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noinline
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int kstrtos16(const char *s, unsigned int base, s16 *res)
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{
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	long long tmp;
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	int rv;
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	rv = kstrtoll(s, base, &tmp);
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	if (rv < 0)
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		return rv;
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	if (tmp != (s16)tmp)
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		return -ERANGE;
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	*res = tmp;
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	return 0;
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}
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EXPORT_SYMBOL(kstrtos16);
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noinline
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int kstrtou8(const char *s, unsigned int base, u8 *res)
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{
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	unsigned long long tmp;
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	int rv;
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	rv = kstrtoull(s, base, &tmp);
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	if (rv < 0)
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		return rv;
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	if (tmp != (u8)tmp)
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		return -ERANGE;
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	*res = tmp;
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	return 0;
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}
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EXPORT_SYMBOL(kstrtou8);
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noinline
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int kstrtos8(const char *s, unsigned int base, s8 *res)
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{
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	long long tmp;
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	int rv;
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	rv = kstrtoll(s, base, &tmp);
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	if (rv < 0)
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		return rv;
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	if (tmp != (s8)tmp)
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		return -ERANGE;
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	*res = tmp;
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	return 0;
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}
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EXPORT_SYMBOL(kstrtos8);
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/**
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 * kstrtobool - convert common user inputs into boolean values
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 * @s: input string
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 * @res: result
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 *
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 * This routine returns 0 iff the first character is one of 'YyTt1NnFf0', or
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 * [oO][NnFf] for "on" and "off". Otherwise it will return -EINVAL.  Value
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 * pointed to by res is updated upon finding a match.
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 */
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noinline
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int kstrtobool(const char *s, bool *res)
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{
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	if (!s)
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		return -EINVAL;
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	switch (s[0]) {
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	case 'y':
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	case 'Y':
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	case 't':
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	case 'T':
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	case '1':
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		*res = true;
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		return 0;
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	case 'n':
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	case 'N':
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	case 'f':
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	case 'F':
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	case '0':
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		*res = false;
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		return 0;
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	case 'o':
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	case 'O':
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		switch (s[1]) {
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		case 'n':
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		case 'N':
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			*res = true;
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			return 0;
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		case 'f':
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		case 'F':
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			*res = false;
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			return 0;
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		default:
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			break;
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		}
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		break;
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	default:
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		break;
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	}
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	return -EINVAL;
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}
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EXPORT_SYMBOL(kstrtobool);
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/*
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 * Since "base" would be a nonsense argument, this open-codes the
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 * _from_user helper instead of using the helper macro below.
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 */
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int kstrtobool_from_user(const char __user *s, size_t count, bool *res)
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{
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	/* Longest string needed to differentiate, newline, terminator */
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	char buf[4];
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	count = min(count, sizeof(buf) - 1);
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	if (copy_from_user(buf, s, count))
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		return -EFAULT;
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	buf[count] = '\0';
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	return kstrtobool(buf, res);
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}
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EXPORT_SYMBOL(kstrtobool_from_user);
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#define kstrto_from_user(f, g, type)					\
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int f(const char __user *s, size_t count, unsigned int base, type *res)	\
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{									\
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	/* sign, base 2 representation, newline, terminator */		\
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	char buf[1 + sizeof(type) * 8 + 1 + 1];				\
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									\
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	count = min(count, sizeof(buf) - 1);				\
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	if (copy_from_user(buf, s, count))				\
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		return -EFAULT;						\
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	buf[count] = '\0';						\
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	return g(buf, base, res);					\
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}									\
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EXPORT_SYMBOL(f)
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kstrto_from_user(kstrtoull_from_user,	kstrtoull,	unsigned long long);
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kstrto_from_user(kstrtoll_from_user,	kstrtoll,	long long);
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kstrto_from_user(kstrtoul_from_user,	kstrtoul,	unsigned long);
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kstrto_from_user(kstrtol_from_user,	kstrtol,	long);
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kstrto_from_user(kstrtouint_from_user,	kstrtouint,	unsigned int);
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kstrto_from_user(kstrtoint_from_user,	kstrtoint,	int);
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kstrto_from_user(kstrtou16_from_user,	kstrtou16,	u16);
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kstrto_from_user(kstrtos16_from_user,	kstrtos16,	s16);
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kstrto_from_user(kstrtou8_from_user,	kstrtou8,	u8);
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kstrto_from_user(kstrtos8_from_user,	kstrtos8,	s8);
 |