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lib/vsprintf.c 26 KB
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  /*
   *  linux/lib/vsprintf.c
   *
   *  Copyright (C) 1991, 1992  Linus Torvalds
   */
  
  /* vsprintf.c -- Lars Wirzenius & Linus Torvalds. */
  /*
   * Wirzenius wrote this portably, Torvalds fucked it up :-)
   */
  
  /* 
   * Fri Jul 13 2001 Crutcher Dunnavant <crutcher+kernel@datastacks.com>
   * - changed to provide snprintf and vsnprintf functions
   * So Feb  1 16:51:32 CET 2004 Juergen Quade <quade@hsnr.de>
   * - scnprintf and vscnprintf
   */
  
  #include <stdarg.h>
  #include <linux/module.h>
  #include <linux/types.h>
  #include <linux/string.h>
  #include <linux/ctype.h>
  #include <linux/kernel.h>
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  #include <asm/page.h>		/* for PAGE_SIZE */
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  #include <asm/div64.h>
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  /* Works only for digits and letters, but small and fast */
  #define TOLOWER(x) ((x) | 0x20)
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  /**
   * simple_strtoul - convert a string to an unsigned long
   * @cp: The start of the string
   * @endp: A pointer to the end of the parsed string will be placed here
   * @base: The number base to use
   */
  unsigned long simple_strtoul(const char *cp,char **endp,unsigned int base)
  {
  	unsigned long result = 0,value;
  
  	if (!base) {
  		base = 10;
  		if (*cp == '0') {
  			base = 8;
  			cp++;
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  			if ((TOLOWER(*cp) == 'x') && isxdigit(cp[1])) {
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  				cp++;
  				base = 16;
  			}
  		}
  	} else if (base == 16) {
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  		if (cp[0] == '0' && TOLOWER(cp[1]) == 'x')
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  			cp += 2;
  	}
  	while (isxdigit(*cp) &&
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  	       (value = isdigit(*cp) ? *cp-'0' : TOLOWER(*cp)-'a'+10) < base) {
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  		result = result*base + value;
  		cp++;
  	}
  	if (endp)
  		*endp = (char *)cp;
  	return result;
  }
  
  EXPORT_SYMBOL(simple_strtoul);
  
  /**
   * simple_strtol - convert a string to a signed long
   * @cp: The start of the string
   * @endp: A pointer to the end of the parsed string will be placed here
   * @base: The number base to use
   */
  long simple_strtol(const char *cp,char **endp,unsigned int base)
  {
  	if(*cp=='-')
  		return -simple_strtoul(cp+1,endp,base);
  	return simple_strtoul(cp,endp,base);
  }
  
  EXPORT_SYMBOL(simple_strtol);
  
  /**
   * simple_strtoull - convert a string to an unsigned long long
   * @cp: The start of the string
   * @endp: A pointer to the end of the parsed string will be placed here
   * @base: The number base to use
   */
  unsigned long long simple_strtoull(const char *cp,char **endp,unsigned int base)
  {
  	unsigned long long result = 0,value;
  
  	if (!base) {
  		base = 10;
  		if (*cp == '0') {
  			base = 8;
  			cp++;
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  			if ((TOLOWER(*cp) == 'x') && isxdigit(cp[1])) {
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  				cp++;
  				base = 16;
  			}
  		}
  	} else if (base == 16) {
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  		if (cp[0] == '0' && TOLOWER(cp[1]) == 'x')
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  			cp += 2;
  	}
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  	while (isxdigit(*cp)
  	 && (value = isdigit(*cp) ? *cp-'0' : TOLOWER(*cp)-'a'+10) < base) {
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  		result = result*base + value;
  		cp++;
  	}
  	if (endp)
  		*endp = (char *)cp;
  	return result;
  }
  
  EXPORT_SYMBOL(simple_strtoull);
  
  /**
   * simple_strtoll - convert a string to a signed long long
   * @cp: The start of the string
   * @endp: A pointer to the end of the parsed string will be placed here
   * @base: The number base to use
   */
  long long simple_strtoll(const char *cp,char **endp,unsigned int base)
  {
  	if(*cp=='-')
  		return -simple_strtoull(cp+1,endp,base);
  	return simple_strtoull(cp,endp,base);
  }
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  /**
   * strict_strtoul - convert a string to an unsigned long strictly
   * @cp: The string to be converted
   * @base: The number base to use
   * @res: The converted result value
   *
   * strict_strtoul converts a string to an unsigned long only if the
   * string is really an unsigned long string, any string containing
   * any invalid char at the tail will be rejected and -EINVAL is returned,
   * only a newline char at the tail is acceptible because people generally
   * change a module parameter in the following way:
   *
   * 	echo 1024 > /sys/module/e1000/parameters/copybreak
   *
   * echo will append a newline to the tail.
   *
   * It returns 0 if conversion is successful and *res is set to the converted
   * value, otherwise it returns -EINVAL and *res is set to 0.
   *
   * simple_strtoul just ignores the successive invalid characters and
   * return the converted value of prefix part of the string.
   */
  int strict_strtoul(const char *cp, unsigned int base, unsigned long *res);
  
  /**
   * strict_strtol - convert a string to a long strictly
   * @cp: The string to be converted
   * @base: The number base to use
   * @res: The converted result value
   *
   * strict_strtol is similiar to strict_strtoul, but it allows the first
   * character of a string is '-'.
   *
   * It returns 0 if conversion is successful and *res is set to the converted
   * value, otherwise it returns -EINVAL and *res is set to 0.
   */
  int strict_strtol(const char *cp, unsigned int base, long *res);
  
  /**
   * strict_strtoull - convert a string to an unsigned long long strictly
   * @cp: The string to be converted
   * @base: The number base to use
   * @res: The converted result value
   *
   * strict_strtoull converts a string to an unsigned long long only if the
   * string is really an unsigned long long string, any string containing
   * any invalid char at the tail will be rejected and -EINVAL is returned,
   * only a newline char at the tail is acceptible because people generally
   * change a module parameter in the following way:
   *
   * 	echo 1024 > /sys/module/e1000/parameters/copybreak
   *
   * echo will append a newline to the tail of the string.
   *
   * It returns 0 if conversion is successful and *res is set to the converted
   * value, otherwise it returns -EINVAL and *res is set to 0.
   *
   * simple_strtoull just ignores the successive invalid characters and
   * return the converted value of prefix part of the string.
   */
  int strict_strtoull(const char *cp, unsigned int base, unsigned long long *res);
  
  /**
   * strict_strtoll - convert a string to a long long strictly
   * @cp: The string to be converted
   * @base: The number base to use
   * @res: The converted result value
   *
   * strict_strtoll is similiar to strict_strtoull, but it allows the first
   * character of a string is '-'.
   *
   * It returns 0 if conversion is successful and *res is set to the converted
   * value, otherwise it returns -EINVAL and *res is set to 0.
   */
  int strict_strtoll(const char *cp, unsigned int base, long long *res);
  
  #define define_strict_strtoux(type, valtype)				\
  int strict_strtou##type(const char *cp, unsigned int base, valtype *res)\
  {									\
  	char *tail;							\
  	valtype val;							\
  	size_t len;							\
  									\
  	*res = 0;							\
  	len = strlen(cp);						\
  	if (len == 0)							\
  		return -EINVAL;						\
  									\
  	val = simple_strtoul(cp, &tail, base);				\
  	if ((*tail == '\0') ||						\
  		((len == (size_t)(tail - cp) + 1) && (*tail == '
  '))) {\
  		*res = val;						\
  		return 0;						\
  	}								\
  									\
  	return -EINVAL;							\
  }									\
  
  #define define_strict_strtox(type, valtype)				\
  int strict_strto##type(const char *cp, unsigned int base, valtype *res)	\
  {									\
  	int ret;							\
  	if (*cp == '-') {						\
  		ret = strict_strtou##type(cp+1, base, res);		\
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  		if (!ret)						\
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  			*res = -(*res);					\
  	} else								\
  		ret = strict_strtou##type(cp, base, res);		\
  									\
  	return ret;							\
  }									\
  
  define_strict_strtoux(l, unsigned long)
  define_strict_strtox(l, long)
  define_strict_strtoux(ll, unsigned long long)
  define_strict_strtox(ll, long long)
  
  EXPORT_SYMBOL(strict_strtoul);
  EXPORT_SYMBOL(strict_strtol);
  EXPORT_SYMBOL(strict_strtoll);
  EXPORT_SYMBOL(strict_strtoull);
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  static int skip_atoi(const char **s)
  {
  	int i=0;
  
  	while (isdigit(**s))
  		i = i*10 + *((*s)++) - '0';
  	return i;
  }
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  /* Decimal conversion is by far the most typical, and is used
   * for /proc and /sys data. This directly impacts e.g. top performance
   * with many processes running. We optimize it for speed
   * using code from
   * http://www.cs.uiowa.edu/~jones/bcd/decimal.html
   * (with permission from the author, Douglas W. Jones). */
  
  /* Formats correctly any integer in [0,99999].
   * Outputs from one to five digits depending on input.
   * On i386 gcc 4.1.2 -O2: ~250 bytes of code. */
  static char* put_dec_trunc(char *buf, unsigned q)
  {
  	unsigned d3, d2, d1, d0;
  	d1 = (q>>4) & 0xf;
  	d2 = (q>>8) & 0xf;
  	d3 = (q>>12);
  
  	d0 = 6*(d3 + d2 + d1) + (q & 0xf);
  	q = (d0 * 0xcd) >> 11;
  	d0 = d0 - 10*q;
  	*buf++ = d0 + '0'; /* least significant digit */
  	d1 = q + 9*d3 + 5*d2 + d1;
  	if (d1 != 0) {
  		q = (d1 * 0xcd) >> 11;
  		d1 = d1 - 10*q;
  		*buf++ = d1 + '0'; /* next digit */
  
  		d2 = q + 2*d2;
  		if ((d2 != 0) || (d3 != 0)) {
  			q = (d2 * 0xd) >> 7;
  			d2 = d2 - 10*q;
  			*buf++ = d2 + '0'; /* next digit */
  
  			d3 = q + 4*d3;
  			if (d3 != 0) {
  				q = (d3 * 0xcd) >> 11;
  				d3 = d3 - 10*q;
  				*buf++ = d3 + '0';  /* next digit */
  				if (q != 0)
  					*buf++ = q + '0';  /* most sign. digit */
  			}
  		}
  	}
  	return buf;
  }
  /* Same with if's removed. Always emits five digits */
  static char* put_dec_full(char *buf, unsigned q)
  {
  	/* BTW, if q is in [0,9999], 8-bit ints will be enough, */
  	/* but anyway, gcc produces better code with full-sized ints */
  	unsigned d3, d2, d1, d0;
  	d1 = (q>>4) & 0xf;
  	d2 = (q>>8) & 0xf;
  	d3 = (q>>12);
  
  	/* Possible ways to approx. divide by 10 */
  	/* gcc -O2 replaces multiply with shifts and adds */
  	// (x * 0xcd) >> 11: 11001101 - shorter code than * 0x67 (on i386)
  	// (x * 0x67) >> 10:  1100111
  	// (x * 0x34) >> 9:    110100 - same
  	// (x * 0x1a) >> 8:     11010 - same
  	// (x * 0x0d) >> 7:      1101 - same, shortest code (on i386)
  
  	d0 = 6*(d3 + d2 + d1) + (q & 0xf);
  	q = (d0 * 0xcd) >> 11;
  	d0 = d0 - 10*q;
  	*buf++ = d0 + '0';
  	d1 = q + 9*d3 + 5*d2 + d1;
  		q = (d1 * 0xcd) >> 11;
  		d1 = d1 - 10*q;
  		*buf++ = d1 + '0';
  
  		d2 = q + 2*d2;
  			q = (d2 * 0xd) >> 7;
  			d2 = d2 - 10*q;
  			*buf++ = d2 + '0';
  
  			d3 = q + 4*d3;
  				q = (d3 * 0xcd) >> 11; /* - shorter code */
  				/* q = (d3 * 0x67) >> 10; - would also work */
  				d3 = d3 - 10*q;
  				*buf++ = d3 + '0';
  					*buf++ = q + '0';
  	return buf;
  }
  /* No inlining helps gcc to use registers better */
  static noinline char* put_dec(char *buf, unsigned long long num)
  {
  	while (1) {
  		unsigned rem;
  		if (num < 100000)
  			return put_dec_trunc(buf, num);
  		rem = do_div(num, 100000);
  		buf = put_dec_full(buf, rem);
  	}
  }
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  #define ZEROPAD	1		/* pad with zero */
  #define SIGN	2		/* unsigned/signed long */
  #define PLUS	4		/* show plus */
  #define SPACE	8		/* space if plus */
  #define LEFT	16		/* left justified */
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  #define SMALL	32		/* Must be 32 == 0x20 */
  #define SPECIAL	64		/* 0x */
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  static char *number(char *buf, char *end, unsigned long long num, int base, int size, int precision, int type)
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  {
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  	/* we are called with base 8, 10 or 16, only, thus don't need "G..."  */
  	static const char digits[16] = "0123456789ABCDEF"; /* "GHIJKLMNOPQRSTUVWXYZ"; */
  
  	char tmp[66];
  	char sign;
  	char locase;
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  	int need_pfx = ((type & SPECIAL) && base != 10);
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  	int i;
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  	/* locase = 0 or 0x20. ORing digits or letters with 'locase'
  	 * produces same digits or (maybe lowercased) letters */
  	locase = (type & SMALL);
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  	if (type & LEFT)
  		type &= ~ZEROPAD;
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  	sign = 0;
  	if (type & SIGN) {
  		if ((signed long long) num < 0) {
  			sign = '-';
  			num = - (signed long long) num;
  			size--;
  		} else if (type & PLUS) {
  			sign = '+';
  			size--;
  		} else if (type & SPACE) {
  			sign = ' ';
  			size--;
  		}
  	}
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  	if (need_pfx) {
  		size--;
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  		if (base == 16)
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  			size--;
  	}
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  	/* generate full string in tmp[], in reverse order */
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  	i = 0;
  	if (num == 0)
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  		tmp[i++] = '0';
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  	/* Generic code, for any base:
  	else do {
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  		tmp[i++] = (digits[do_div(num,base)] | locase);
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  	} while (num != 0);
  	*/
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  	else if (base != 10) { /* 8 or 16 */
  		int mask = base - 1;
  		int shift = 3;
  		if (base == 16) shift = 4;
  		do {
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  			tmp[i++] = (digits[((unsigned char)num) & mask] | locase);
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  			num >>= shift;
  		} while (num);
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  	} else { /* base 10 */
  		i = put_dec(tmp, num) - tmp;
  	}
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  	/* printing 100 using %2d gives "100", not "00" */
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  	if (i > precision)
  		precision = i;
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  	/* leading space padding */
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  	size -= precision;
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  	if (!(type & (ZEROPAD+LEFT))) {
  		while(--size >= 0) {
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  			if (buf < end)
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  				*buf = ' ';
  			++buf;
  		}
  	}
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  	/* sign */
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  	if (sign) {
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  		if (buf < end)
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  			*buf = sign;
  		++buf;
  	}
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  	/* "0x" / "0" prefix */
  	if (need_pfx) {
  		if (buf < end)
  			*buf = '0';
  		++buf;
  		if (base == 16) {
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  			if (buf < end)
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  				*buf = ('X' | locase);
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
445
446
447
  			++buf;
  		}
  	}
b39a73409   Denis Vlasenko   vsprintf.c: optim...
448
  	/* zero or space padding */
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
449
  	if (!(type & LEFT)) {
b39a73409   Denis Vlasenko   vsprintf.c: optim...
450
451
  		char c = (type & ZEROPAD) ? '0' : ' ';
  		while (--size >= 0) {
f796937a0   Jeremy Fitzhardinge   [PATCH] Fix bound...
452
  			if (buf < end)
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
453
454
455
456
  				*buf = c;
  			++buf;
  		}
  	}
b39a73409   Denis Vlasenko   vsprintf.c: optim...
457
458
  	/* hmm even more zero padding? */
  	while (i <= --precision) {
f796937a0   Jeremy Fitzhardinge   [PATCH] Fix bound...
459
  		if (buf < end)
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
460
461
462
  			*buf = '0';
  		++buf;
  	}
b39a73409   Denis Vlasenko   vsprintf.c: optim...
463
464
  	/* actual digits of result */
  	while (--i >= 0) {
f796937a0   Jeremy Fitzhardinge   [PATCH] Fix bound...
465
  		if (buf < end)
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
466
467
468
  			*buf = tmp[i];
  		++buf;
  	}
b39a73409   Denis Vlasenko   vsprintf.c: optim...
469
470
  	/* trailing space padding */
  	while (--size >= 0) {
f796937a0   Jeremy Fitzhardinge   [PATCH] Fix bound...
471
  		if (buf < end)
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
  			*buf = ' ';
  		++buf;
  	}
  	return buf;
  }
  
  /**
   * vsnprintf - Format a string and place it in a buffer
   * @buf: The buffer to place the result into
   * @size: The size of the buffer, including the trailing null space
   * @fmt: The format string to use
   * @args: Arguments for the format string
   *
   * The return value is the number of characters which would
   * be generated for the given input, excluding the trailing
   * '\0', as per ISO C99. If you want to have the exact
   * number of characters written into @buf as return value
72fd4a35a   Robert P. J. Day   [PATCH] Numerous ...
489
   * (not including the trailing '\0'), use vscnprintf(). If the
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
490
491
492
493
   * return is greater than or equal to @size, the resulting
   * string is truncated.
   *
   * Call this function if you are already dealing with a va_list.
72fd4a35a   Robert P. J. Day   [PATCH] Numerous ...
494
   * You probably want snprintf() instead.
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
   */
  int vsnprintf(char *buf, size_t size, const char *fmt, va_list args)
  {
  	int len;
  	unsigned long long num;
  	int i, base;
  	char *str, *end, c;
  	const char *s;
  
  	int flags;		/* flags to number() */
  
  	int field_width;	/* width of output field */
  	int precision;		/* min. # of digits for integers; max
  				   number of chars for from string */
  	int qualifier;		/* 'h', 'l', or 'L' for integer fields */
  				/* 'z' support added 23/7/1999 S.H.    */
  				/* 'z' changed to 'Z' --davidm 1/25/99 */
803223069   Al Viro   [PATCH] %t... in ...
512
  				/* 't' added for ptrdiff_t */
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
513

f796937a0   Jeremy Fitzhardinge   [PATCH] Fix bound...
514
515
  	/* Reject out-of-range values early.  Large positive sizes are
  	   used for unknown buffer sizes. */
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
516
517
  	if (unlikely((int) size < 0)) {
  		/* There can be only one.. */
b39a73409   Denis Vlasenko   vsprintf.c: optim...
518
  		static char warn = 1;
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
519
520
521
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523
524
  		WARN_ON(warn);
  		warn = 0;
  		return 0;
  	}
  
  	str = buf;
f796937a0   Jeremy Fitzhardinge   [PATCH] Fix bound...
525
  	end = buf + size;
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
526

f796937a0   Jeremy Fitzhardinge   [PATCH] Fix bound...
527
528
529
530
  	/* Make sure end is always >= buf */
  	if (end < buf) {
  		end = ((void *)-1);
  		size = end - buf;
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
531
532
533
534
  	}
  
  	for (; *fmt ; ++fmt) {
  		if (*fmt != '%') {
f796937a0   Jeremy Fitzhardinge   [PATCH] Fix bound...
535
  			if (str < end)
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
536
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540
541
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  				*str = *fmt;
  			++str;
  			continue;
  		}
  
  		/* process flags */
  		flags = 0;
  		repeat:
  			++fmt;		/* this also skips first '%' */
  			switch (*fmt) {
  				case '-': flags |= LEFT; goto repeat;
  				case '+': flags |= PLUS; goto repeat;
  				case ' ': flags |= SPACE; goto repeat;
  				case '#': flags |= SPECIAL; goto repeat;
  				case '0': flags |= ZEROPAD; goto repeat;
  			}
  
  		/* get field width */
  		field_width = -1;
  		if (isdigit(*fmt))
  			field_width = skip_atoi(&fmt);
  		else if (*fmt == '*') {
  			++fmt;
  			/* it's the next argument */
  			field_width = va_arg(args, int);
  			if (field_width < 0) {
  				field_width = -field_width;
  				flags |= LEFT;
  			}
  		}
  
  		/* get the precision */
  		precision = -1;
  		if (*fmt == '.') {
  			++fmt;	
  			if (isdigit(*fmt))
  				precision = skip_atoi(&fmt);
  			else if (*fmt == '*') {
  				++fmt;
  				/* it's the next argument */
  				precision = va_arg(args, int);
  			}
  			if (precision < 0)
  				precision = 0;
  		}
  
  		/* get the conversion qualifier */
  		qualifier = -1;
  		if (*fmt == 'h' || *fmt == 'l' || *fmt == 'L' ||
803223069   Al Viro   [PATCH] %t... in ...
585
  		    *fmt =='Z' || *fmt == 'z' || *fmt == 't') {
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
  			qualifier = *fmt;
  			++fmt;
  			if (qualifier == 'l' && *fmt == 'l') {
  				qualifier = 'L';
  				++fmt;
  			}
  		}
  
  		/* default base */
  		base = 10;
  
  		switch (*fmt) {
  			case 'c':
  				if (!(flags & LEFT)) {
  					while (--field_width > 0) {
f796937a0   Jeremy Fitzhardinge   [PATCH] Fix bound...
601
  						if (str < end)
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
602
603
604
605
606
  							*str = ' ';
  						++str;
  					}
  				}
  				c = (unsigned char) va_arg(args, int);
f796937a0   Jeremy Fitzhardinge   [PATCH] Fix bound...
607
  				if (str < end)
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
608
609
610
  					*str = c;
  				++str;
  				while (--field_width > 0) {
f796937a0   Jeremy Fitzhardinge   [PATCH] Fix bound...
611
  					if (str < end)
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
612
613
614
615
616
617
618
619
620
621
622
623
624
625
  						*str = ' ';
  					++str;
  				}
  				continue;
  
  			case 's':
  				s = va_arg(args, char *);
  				if ((unsigned long)s < PAGE_SIZE)
  					s = "<NULL>";
  
  				len = strnlen(s, precision);
  
  				if (!(flags & LEFT)) {
  					while (len < field_width--) {
f796937a0   Jeremy Fitzhardinge   [PATCH] Fix bound...
626
  						if (str < end)
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
627
628
629
630
631
  							*str = ' ';
  						++str;
  					}
  				}
  				for (i = 0; i < len; ++i) {
f796937a0   Jeremy Fitzhardinge   [PATCH] Fix bound...
632
  					if (str < end)
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
633
634
635
636
  						*str = *s;
  					++str; ++s;
  				}
  				while (len < field_width--) {
f796937a0   Jeremy Fitzhardinge   [PATCH] Fix bound...
637
  					if (str < end)
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
638
639
640
641
642
643
  						*str = ' ';
  					++str;
  				}
  				continue;
  
  			case 'p':
9b706aee7   Denys Vlasenko   x86: trivial prin...
644
  				flags |= SMALL;
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
645
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  				if (field_width == -1) {
  					field_width = 2*sizeof(void *);
  					flags |= ZEROPAD;
  				}
  				str = number(str, end,
  						(unsigned long) va_arg(args, void *),
  						16, field_width, precision, flags);
  				continue;
  
  
  			case 'n':
  				/* FIXME:
  				* What does C99 say about the overflow case here? */
  				if (qualifier == 'l') {
  					long * ip = va_arg(args, long *);
  					*ip = (str - buf);
  				} else if (qualifier == 'Z' || qualifier == 'z') {
  					size_t * ip = va_arg(args, size_t *);
  					*ip = (str - buf);
  				} else {
  					int * ip = va_arg(args, int *);
  					*ip = (str - buf);
  				}
  				continue;
  
  			case '%':
f796937a0   Jeremy Fitzhardinge   [PATCH] Fix bound...
671
  				if (str < end)
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
672
673
674
675
676
677
678
679
  					*str = '%';
  				++str;
  				continue;
  
  				/* integer number formats - set up the flags and "break" */
  			case 'o':
  				base = 8;
  				break;
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
680
  			case 'x':
9b706aee7   Denys Vlasenko   x86: trivial prin...
681
682
  				flags |= SMALL;
  			case 'X':
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
683
684
685
686
687
688
689
690
691
692
  				base = 16;
  				break;
  
  			case 'd':
  			case 'i':
  				flags |= SIGN;
  			case 'u':
  				break;
  
  			default:
f796937a0   Jeremy Fitzhardinge   [PATCH] Fix bound...
693
  				if (str < end)
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
694
695
696
  					*str = '%';
  				++str;
  				if (*fmt) {
f796937a0   Jeremy Fitzhardinge   [PATCH] Fix bound...
697
  					if (str < end)
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
698
699
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701
702
703
704
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  						*str = *fmt;
  					++str;
  				} else {
  					--fmt;
  				}
  				continue;
  		}
  		if (qualifier == 'L')
  			num = va_arg(args, long long);
  		else if (qualifier == 'l') {
  			num = va_arg(args, unsigned long);
  			if (flags & SIGN)
  				num = (signed long) num;
  		} else if (qualifier == 'Z' || qualifier == 'z') {
  			num = va_arg(args, size_t);
803223069   Al Viro   [PATCH] %t... in ...
713
714
  		} else if (qualifier == 't') {
  			num = va_arg(args, ptrdiff_t);
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
715
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717
718
719
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721
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723
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  		} else if (qualifier == 'h') {
  			num = (unsigned short) va_arg(args, int);
  			if (flags & SIGN)
  				num = (signed short) num;
  		} else {
  			num = va_arg(args, unsigned int);
  			if (flags & SIGN)
  				num = (signed int) num;
  		}
  		str = number(str, end, num, base,
  				field_width, precision, flags);
  	}
f796937a0   Jeremy Fitzhardinge   [PATCH] Fix bound...
727
728
729
730
  	if (size > 0) {
  		if (str < end)
  			*str = '\0';
  		else
0a6047eef   Linus Torvalds   Fix vsnprintf off...
731
  			end[-1] = '\0';
f796937a0   Jeremy Fitzhardinge   [PATCH] Fix bound...
732
733
  	}
  	/* the trailing null byte doesn't count towards the total */
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
734
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  	return str-buf;
  }
  
  EXPORT_SYMBOL(vsnprintf);
  
  /**
   * vscnprintf - Format a string and place it in a buffer
   * @buf: The buffer to place the result into
   * @size: The size of the buffer, including the trailing null space
   * @fmt: The format string to use
   * @args: Arguments for the format string
   *
   * The return value is the number of characters which have been written into
   * the @buf not including the trailing '\0'. If @size is <= 0 the function
   * returns 0.
   *
   * Call this function if you are already dealing with a va_list.
72fd4a35a   Robert P. J. Day   [PATCH] Numerous ...
751
   * You probably want scnprintf() instead.
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
752
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   */
  int vscnprintf(char *buf, size_t size, const char *fmt, va_list args)
  {
  	int i;
  
  	i=vsnprintf(buf,size,fmt,args);
  	return (i >= size) ? (size - 1) : i;
  }
  
  EXPORT_SYMBOL(vscnprintf);
  
  /**
   * snprintf - Format a string and place it in a buffer
   * @buf: The buffer to place the result into
   * @size: The size of the buffer, including the trailing null space
   * @fmt: The format string to use
   * @...: Arguments for the format string
   *
   * The return value is the number of characters which would be
   * generated for the given input, excluding the trailing null,
   * as per ISO C99.  If the return is greater than or equal to
   * @size, the resulting string is truncated.
   */
  int snprintf(char * buf, size_t size, const char *fmt, ...)
  {
  	va_list args;
  	int i;
  
  	va_start(args, fmt);
  	i=vsnprintf(buf,size,fmt,args);
  	va_end(args);
  	return i;
  }
  
  EXPORT_SYMBOL(snprintf);
  
  /**
   * scnprintf - Format a string and place it in a buffer
   * @buf: The buffer to place the result into
   * @size: The size of the buffer, including the trailing null space
   * @fmt: The format string to use
   * @...: Arguments for the format string
   *
   * The return value is the number of characters written into @buf not including
ea6f3281a   Martin Peschke   [PATCH] scnprintf...
796
   * the trailing '\0'. If @size is <= 0 the function returns 0.
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
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   */
  
  int scnprintf(char * buf, size_t size, const char *fmt, ...)
  {
  	va_list args;
  	int i;
  
  	va_start(args, fmt);
  	i = vsnprintf(buf, size, fmt, args);
  	va_end(args);
  	return (i >= size) ? (size - 1) : i;
  }
  EXPORT_SYMBOL(scnprintf);
  
  /**
   * vsprintf - Format a string and place it in a buffer
   * @buf: The buffer to place the result into
   * @fmt: The format string to use
   * @args: Arguments for the format string
   *
   * The function returns the number of characters written
72fd4a35a   Robert P. J. Day   [PATCH] Numerous ...
818
   * into @buf. Use vsnprintf() or vscnprintf() in order to avoid
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
819
820
821
   * buffer overflows.
   *
   * Call this function if you are already dealing with a va_list.
72fd4a35a   Robert P. J. Day   [PATCH] Numerous ...
822
   * You probably want sprintf() instead.
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
823
824
825
826
827
828
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830
831
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834
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836
837
   */
  int vsprintf(char *buf, const char *fmt, va_list args)
  {
  	return vsnprintf(buf, INT_MAX, fmt, args);
  }
  
  EXPORT_SYMBOL(vsprintf);
  
  /**
   * sprintf - Format a string and place it in a buffer
   * @buf: The buffer to place the result into
   * @fmt: The format string to use
   * @...: Arguments for the format string
   *
   * The function returns the number of characters written
72fd4a35a   Robert P. J. Day   [PATCH] Numerous ...
838
   * into @buf. Use snprintf() or scnprintf() in order to avoid
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
839
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1060
1061
1062
1063
1064
1065
1066
   * buffer overflows.
   */
  int sprintf(char * buf, const char *fmt, ...)
  {
  	va_list args;
  	int i;
  
  	va_start(args, fmt);
  	i=vsnprintf(buf, INT_MAX, fmt, args);
  	va_end(args);
  	return i;
  }
  
  EXPORT_SYMBOL(sprintf);
  
  /**
   * vsscanf - Unformat a buffer into a list of arguments
   * @buf:	input buffer
   * @fmt:	format of buffer
   * @args:	arguments
   */
  int vsscanf(const char * buf, const char * fmt, va_list args)
  {
  	const char *str = buf;
  	char *next;
  	char digit;
  	int num = 0;
  	int qualifier;
  	int base;
  	int field_width;
  	int is_sign = 0;
  
  	while(*fmt && *str) {
  		/* skip any white space in format */
  		/* white space in format matchs any amount of
  		 * white space, including none, in the input.
  		 */
  		if (isspace(*fmt)) {
  			while (isspace(*fmt))
  				++fmt;
  			while (isspace(*str))
  				++str;
  		}
  
  		/* anything that is not a conversion must match exactly */
  		if (*fmt != '%' && *fmt) {
  			if (*fmt++ != *str++)
  				break;
  			continue;
  		}
  
  		if (!*fmt)
  			break;
  		++fmt;
  		
  		/* skip this conversion.
  		 * advance both strings to next white space
  		 */
  		if (*fmt == '*') {
  			while (!isspace(*fmt) && *fmt)
  				fmt++;
  			while (!isspace(*str) && *str)
  				str++;
  			continue;
  		}
  
  		/* get field width */
  		field_width = -1;
  		if (isdigit(*fmt))
  			field_width = skip_atoi(&fmt);
  
  		/* get conversion qualifier */
  		qualifier = -1;
  		if (*fmt == 'h' || *fmt == 'l' || *fmt == 'L' ||
  		    *fmt == 'Z' || *fmt == 'z') {
  			qualifier = *fmt++;
  			if (unlikely(qualifier == *fmt)) {
  				if (qualifier == 'h') {
  					qualifier = 'H';
  					fmt++;
  				} else if (qualifier == 'l') {
  					qualifier = 'L';
  					fmt++;
  				}
  			}
  		}
  		base = 10;
  		is_sign = 0;
  
  		if (!*fmt || !*str)
  			break;
  
  		switch(*fmt++) {
  		case 'c':
  		{
  			char *s = (char *) va_arg(args,char*);
  			if (field_width == -1)
  				field_width = 1;
  			do {
  				*s++ = *str++;
  			} while (--field_width > 0 && *str);
  			num++;
  		}
  		continue;
  		case 's':
  		{
  			char *s = (char *) va_arg(args, char *);
  			if(field_width == -1)
  				field_width = INT_MAX;
  			/* first, skip leading white space in buffer */
  			while (isspace(*str))
  				str++;
  
  			/* now copy until next white space */
  			while (*str && !isspace(*str) && field_width--) {
  				*s++ = *str++;
  			}
  			*s = '\0';
  			num++;
  		}
  		continue;
  		case 'n':
  			/* return number of characters read so far */
  		{
  			int *i = (int *)va_arg(args,int*);
  			*i = str - buf;
  		}
  		continue;
  		case 'o':
  			base = 8;
  			break;
  		case 'x':
  		case 'X':
  			base = 16;
  			break;
  		case 'i':
                          base = 0;
  		case 'd':
  			is_sign = 1;
  		case 'u':
  			break;
  		case '%':
  			/* looking for '%' in str */
  			if (*str++ != '%') 
  				return num;
  			continue;
  		default:
  			/* invalid format; stop here */
  			return num;
  		}
  
  		/* have some sort of integer conversion.
  		 * first, skip white space in buffer.
  		 */
  		while (isspace(*str))
  			str++;
  
  		digit = *str;
  		if (is_sign && digit == '-')
  			digit = *(str + 1);
  
  		if (!digit
                      || (base == 16 && !isxdigit(digit))
                      || (base == 10 && !isdigit(digit))
                      || (base == 8 && (!isdigit(digit) || digit > '7'))
                      || (base == 0 && !isdigit(digit)))
  				break;
  
  		switch(qualifier) {
  		case 'H':	/* that's 'hh' in format */
  			if (is_sign) {
  				signed char *s = (signed char *) va_arg(args,signed char *);
  				*s = (signed char) simple_strtol(str,&next,base);
  			} else {
  				unsigned char *s = (unsigned char *) va_arg(args, unsigned char *);
  				*s = (unsigned char) simple_strtoul(str, &next, base);
  			}
  			break;
  		case 'h':
  			if (is_sign) {
  				short *s = (short *) va_arg(args,short *);
  				*s = (short) simple_strtol(str,&next,base);
  			} else {
  				unsigned short *s = (unsigned short *) va_arg(args, unsigned short *);
  				*s = (unsigned short) simple_strtoul(str, &next, base);
  			}
  			break;
  		case 'l':
  			if (is_sign) {
  				long *l = (long *) va_arg(args,long *);
  				*l = simple_strtol(str,&next,base);
  			} else {
  				unsigned long *l = (unsigned long*) va_arg(args,unsigned long*);
  				*l = simple_strtoul(str,&next,base);
  			}
  			break;
  		case 'L':
  			if (is_sign) {
  				long long *l = (long long*) va_arg(args,long long *);
  				*l = simple_strtoll(str,&next,base);
  			} else {
  				unsigned long long *l = (unsigned long long*) va_arg(args,unsigned long long*);
  				*l = simple_strtoull(str,&next,base);
  			}
  			break;
  		case 'Z':
  		case 'z':
  		{
  			size_t *s = (size_t*) va_arg(args,size_t*);
  			*s = (size_t) simple_strtoul(str,&next,base);
  		}
  		break;
  		default:
  			if (is_sign) {
  				int *i = (int *) va_arg(args, int*);
  				*i = (int) simple_strtol(str,&next,base);
  			} else {
  				unsigned int *i = (unsigned int*) va_arg(args, unsigned int*);
  				*i = (unsigned int) simple_strtoul(str,&next,base);
  			}
  			break;
  		}
  		num++;
  
  		if (!next)
  			break;
  		str = next;
  	}
c6b40d16d   Johannes Berg   fix sscanf %n mat...
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  	/*
  	 * Now we've come all the way through so either the input string or the
  	 * format ended. In the former case, there can be a %n at the current
  	 * position in the format that needs to be filled.
  	 */
  	if (*fmt == '%' && *(fmt + 1) == 'n') {
  		int *p = (int *)va_arg(args, int *);
  		*p = str - buf;
  	}
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2
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  	return num;
  }
  
  EXPORT_SYMBOL(vsscanf);
  
  /**
   * sscanf - Unformat a buffer into a list of arguments
   * @buf:	input buffer
   * @fmt:	formatting of buffer
   * @...:	resulting arguments
   */
  int sscanf(const char * buf, const char * fmt, ...)
  {
  	va_list args;
  	int i;
  
  	va_start(args,fmt);
  	i = vsscanf(buf,fmt,args);
  	va_end(args);
  	return i;
  }
  
  EXPORT_SYMBOL(sscanf);