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Commit 1dff46d6 authored by Alexey Dobriyan's avatar Alexey Dobriyan Committed by Linus Torvalds
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lib/kstrtox: common code between kstrto*() and simple_strto*() functions 



Currently termination logic (\0 or \n\0) is hardcoded in _kstrtoull(),
avoid that for code reuse between kstrto*() and simple_strtoull().
Essentially, make them different only in termination logic.

simple_strtoull() (and scanf(), BTW) ignores integer overflow, that's a
bug we currently don't have guts to fix, making KSTRTOX_OVERFLOW hack
necessary.

Almost forgot: patch shrinks code size by about ~80 bytes on x86_64.

Signed-off-by: default avatarAlexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent b3c49c05

lib/kstrtox.c

+53 −22
Original line number Original line Diff line number Diff line
@@ -18,26 +18,40 @@ 
#include <linux/module.h>

#include <linux/module.h>

#include <linux/types.h>

#include <linux/types.h>

#include <asm/uaccess.h>

#include <asm/uaccess.h>

#include "kstrtox.h"





static int _kstrtoull(const char *s, unsigned int base, unsigned long long *res)

const char *_parse_integer_fixup_radix(const char *s, unsigned int *base)

{

{

	unsigned long long acc;

	if (*base == 0) {

	int ok;



	if (base == 0) {

		if (s[0] == '0') {

		if (s[0] == '0') {

			if (_tolower(s[1]) == 'x' && isxdigit(s[2]))

			if (_tolower(s[1]) == 'x' && isxdigit(s[2]))

				base = 16;

				*base = 16;

			else

			else

				base = 8;

				*base = 8;

		} else

		} else

			base = 10;

			*base = 10;

	}

	}

	if (base == 16 && s[0] == '0' && _tolower(s[1]) == 'x')

	if (*base == 16 && s[0] == '0' && _tolower(s[1]) == 'x')

		s += 2;

		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 *res)

{

	unsigned int rv;

	int overflow;





	acc = 0;

	*res = 0;

	ok = 0;

	rv = 0;

	overflow = 0;

	while (*s) {

	while (*s) {

		unsigned int val;

		unsigned int val;
@@ -45,23 +59,40 @@ static int _kstrtoull(const char *s, unsigned int base, unsigned long long *res) 
			val = *s - '0';

			val = *s - '0';

		else if ('a' <= _tolower(*s) && _tolower(*s) <= 'f')

		else if ('a' <= _tolower(*s) && _tolower(*s) <= 'f')

			val = _tolower(*s) - 'a' + 10;

			val = _tolower(*s) - 'a' + 10;

		else if (*s == '\n' && *(s + 1) == '\0')

			break;

		else

		else

			return -EINVAL;

			break;





		if (val >= base)

		if (val >= base)

			return -EINVAL;

			break;

		if (acc > div_u64(ULLONG_MAX - val, base))

		if (*res > div_u64(ULLONG_MAX - val, base))

			return -ERANGE;

			overflow = 1;

		acc = acc * base + val;

		*res = *res * base + val;

		ok = 1;

		rv++;



		s++;

		s++;

	}

	}

	if (!ok)

	if (overflow)

		rv |= KSTRTOX_OVERFLOW;

	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;

	rv &= ~KSTRTOX_OVERFLOW;

	if (rv == 0)

		return -EINVAL;

	s += rv;

	if (*s == '\n')

		s++;

	if (*s)

		return -EINVAL;

		return -EINVAL;

	*res = acc;

	*res = _res;

	return 0;

	return 0;

}

}

lib/kstrtox.h

0 → 100644
+8 −0
Original line number Original line Diff line number Diff line 
#ifndef _LIB_KSTRTOX_H

#define _LIB_KSTRTOX_H



#define KSTRTOX_OVERFLOW	(1U << 31)

const char *_parse_integer_fixup_radix(const char *s, unsigned int *base);

unsigned int _parse_integer(const char *s, unsigned int base, unsigned long long *res);



#endif

lib/vsprintf.c

+7 −26
Original line number Original line Diff line number Diff line
@@ -31,17 +31,7 @@ 
#include <asm/div64.h>

#include <asm/div64.h>

#include <asm/sections.h>	/* for dereference_function_descriptor() */

#include <asm/sections.h>	/* for dereference_function_descriptor() */





static unsigned int simple_guess_base(const char *cp)

#include "kstrtox.h"

{

	if (cp[0] == '0') {

		if (_tolower(cp[1]) == 'x' && isxdigit(cp[2]))

			return 16;

		else

			return 8;

	} else {

		return 10;

	}

}





/**

/**

 * simple_strtoull - convert a string to an unsigned long long

 * simple_strtoull - convert a string to an unsigned long long
@@ -51,23 +41,14 @@ static unsigned int simple_guess_base(const char *cp) 
 */

 */

unsigned long long simple_strtoull(const char *cp, char **endp, unsigned int base)

unsigned long long simple_strtoull(const char *cp, char **endp, unsigned int base)

{

{

	unsigned long long result = 0;

	unsigned long long result;

	unsigned int rv;





	if (!base)

	cp = _parse_integer_fixup_radix(cp, &base);

		base = simple_guess_base(cp);

	rv = _parse_integer(cp, base, &result);

	/* FIXME */

	cp += (rv & ~KSTRTOX_OVERFLOW);





	if (base == 16 && cp[0] == '0' && _tolower(cp[1]) == 'x')

		cp += 2;



	while (isxdigit(*cp)) {

		unsigned int value;



		value = isdigit(*cp) ? *cp - '0' : _tolower(*cp) - 'a' + 10;

		if (value >= base)

			break;

		result = result * base + value;

		cp++;

	}

	if (endp)

	if (endp)

		*endp = (char *)cp;

		*endp = (char *)cp;