 ae2924a2bd
			
		
	
	
	ae2924a2bd
	
	
	
		
			
			We can't reach the cleanup code unless the flag KSTRTOX_OVERFLOW is not set, so there's not no point in clearing a bit that we know is not set. Signed-off-by: Felipe Contreras <felipe.contreras@gmail.com> Acked-by: Levente Kurusa <levex@linux.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
		
			
				
	
	
		
			347 lines
		
	
	
	
		
			9.4 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			347 lines
		
	
	
	
		
			9.4 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
| /*
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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/kernel.h>
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| #include <linux/math64.h>
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| #include <linux/export.h>
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| #include <linux/types.h>
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| #include <asm/uaccess.h>
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| #include "kstrtox.h"
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| 
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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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| /*
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|  * Convert non-negative integer string representation in explicitly given radix
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|  * to an integer.
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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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| unsigned int _parse_integer(const char *s, unsigned int base, unsigned long long *p)
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| {
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| 	unsigned long long res;
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| 	unsigned int rv;
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| 	int overflow;
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| 
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| 	res = 0;
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| 	rv = 0;
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| 	overflow = 0;
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| 	while (*s) {
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| 		unsigned int val;
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| 
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| 		if ('0' <= *s && *s <= '9')
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| 			val = *s - '0';
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| 		else if ('a' <= _tolower(*s) && _tolower(*s) <= 'f')
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| 			val = _tolower(*s) - 'a' + 10;
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| 		else
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| 			break;
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| 
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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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| 				overflow = 1;
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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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| 	if (overflow)
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| 		rv |= KSTRTOX_OVERFLOW;
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| 	return rv;
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| }
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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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| 
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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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| /**
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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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|  * Used as a replacement for the obsolete simple_strtoull. Return code must
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|  * be checked.
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|  */
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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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| /**
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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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|  * Used as a replacement for the obsolete simple_strtoull. Return code must
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|  * be checked.
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|  */
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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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| 
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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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| 
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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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| 
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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 long)(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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| 
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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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| 
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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 long)(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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| /**
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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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|  * Used as a replacement for the obsolete simple_strtoull. Return code must
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|  * be checked.
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|  */
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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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| 
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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 long)(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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| /**
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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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|  * Used as a replacement for the obsolete simple_strtoull. Return code must
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|  * be checked.
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|  */
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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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| 
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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 long)(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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| 
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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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| 
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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 long)(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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| 
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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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| 
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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 long)(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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| 
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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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| 
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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 long)(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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| 
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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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| 
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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 long)(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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| #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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| 
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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);
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