/*
   *  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>	/* for KSYM_SYMBOL_LEN */

  #include <linux/types.h>
  #include <linux/string.h>
  #include <linux/ctype.h>
  #include <linux/kernel.h>

  #include <linux/kallsyms.h>
  #include <linux/uaccess.h>

  #include <linux/ioport.h>

  #include <net/addrconf.h>

  #include <asm/page.h>		/* for PAGE_SIZE */

  #include <asm/div64.h>

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

  #include "kstrtox.h"

  /**

   * 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;
  	unsigned int rv;

  	cp = _parse_integer_fixup_radix(cp, &base);
  	rv = _parse_integer(cp, base, &result);
  	/* FIXME */
  	cp += (rv & ~KSTRTOX_OVERFLOW);

  	if (endp)
  		*endp = (char *)cp;

  	return result;
  }

  EXPORT_SYMBOL(simple_strtoull);

  
  /**

   * 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)

  {

  	return simple_strtoull(cp, endp, base);

  }

  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_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);

  }

  EXPORT_SYMBOL(simple_strtoll);

  static noinline_for_stack
  int skip_atoi(const char **s)

  {

  	int i = 0;

  
  	while (isdigit(**s))
  		i = i*10 + *((*s)++) - '0';

  	return i;
  }

  /* 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 ideas described at <http://www.cs.uiowa.edu/~jones/bcd/divide.html>
   * (with permission from the author, Douglas W. Jones).
   */

  #if BITS_PER_LONG != 32 || BITS_PER_LONG_LONG != 64
  /* Formats correctly any integer in [0, 999999999] */

  static noinline_for_stack

  char *put_dec_full9(char *buf, unsigned q)

  {

  	unsigned r;

  	/*
  	 * Possible ways to approx. divide by 10
  	 * (x * 0x1999999a) >> 32 x < 1073741829 (multiply must be 64-bit)
  	 * (x * 0xcccd) >> 19     x <      81920 (x < 262149 when 64-bit mul)
  	 * (x * 0x6667) >> 18     x <      43699
  	 * (x * 0x3334) >> 17     x <      16389
  	 * (x * 0x199a) >> 16     x <      16389
  	 * (x * 0x0ccd) >> 15     x <      16389
  	 * (x * 0x0667) >> 14     x <       2739
  	 * (x * 0x0334) >> 13     x <       1029
  	 * (x * 0x019a) >> 12     x <       1029
  	 * (x * 0x00cd) >> 11     x <       1029 shorter code than * 0x67 (on i386)
  	 * (x * 0x0067) >> 10     x <        179
  	 * (x * 0x0034) >>  9     x <         69 same
  	 * (x * 0x001a) >>  8     x <         69 same
  	 * (x * 0x000d) >>  7     x <         69 same, shortest code (on i386)
  	 * (x * 0x0007) >>  6     x <         19
  	 * See <http://www.cs.uiowa.edu/~jones/bcd/divide.html>
  	 */
  	r      = (q * (uint64_t)0x1999999a) >> 32;
  	*buf++ = (q - 10 * r) + '0'; /* 1 */
  	q      = (r * (uint64_t)0x1999999a) >> 32;
  	*buf++ = (r - 10 * q) + '0'; /* 2 */
  	r      = (q * (uint64_t)0x1999999a) >> 32;
  	*buf++ = (q - 10 * r) + '0'; /* 3 */
  	q      = (r * (uint64_t)0x1999999a) >> 32;
  	*buf++ = (r - 10 * q) + '0'; /* 4 */
  	r      = (q * (uint64_t)0x1999999a) >> 32;
  	*buf++ = (q - 10 * r) + '0'; /* 5 */
  	/* Now value is under 10000, can avoid 64-bit multiply */
  	q      = (r * 0x199a) >> 16;
  	*buf++ = (r - 10 * q)  + '0'; /* 6 */
  	r      = (q * 0xcd) >> 11;
  	*buf++ = (q - 10 * r)  + '0'; /* 7 */
  	q      = (r * 0xcd) >> 11;
  	*buf++ = (r - 10 * q) + '0'; /* 8 */
  	*buf++ = q + '0'; /* 9 */

  	return buf;
  }

  #endif
  
  /* Similar to above but do not pad with zeros.
   * Code can be easily arranged to print 9 digits too, but our callers
   * always call put_dec_full9() instead when the number has 9 decimal digits.
   */

  static noinline_for_stack

  char *put_dec_trunc8(char *buf, unsigned r)

  {

  	unsigned q;
  
  	/* Copy of previous function's body with added early returns */
  	q      = (r * (uint64_t)0x1999999a) >> 32;
  	*buf++ = (r - 10 * q) + '0'; /* 2 */
  	if (q == 0)
  		return buf;
  	r      = (q * (uint64_t)0x1999999a) >> 32;
  	*buf++ = (q - 10 * r) + '0'; /* 3 */
  	if (r == 0)
  		return buf;
  	q      = (r * (uint64_t)0x1999999a) >> 32;
  	*buf++ = (r - 10 * q) + '0'; /* 4 */
  	if (q == 0)
  		return buf;
  	r      = (q * (uint64_t)0x1999999a) >> 32;
  	*buf++ = (q - 10 * r) + '0'; /* 5 */
  	if (r == 0)
  		return buf;
  	q      = (r * 0x199a) >> 16;
  	*buf++ = (r - 10 * q)  + '0'; /* 6 */
  	if (q == 0)
  		return buf;
  	r      = (q * 0xcd) >> 11;
  	*buf++ = (q - 10 * r)  + '0'; /* 7 */
  	if (r == 0)
  		return buf;
  	q      = (r * 0xcd) >> 11;
  	*buf++ = (r - 10 * q) + '0'; /* 8 */
  	if (q == 0)
  		return buf;
  	*buf++ = q + '0'; /* 9 */
  	return buf;
  }

  /* There are two algorithms to print larger numbers.
   * One is generic: divide by 1000000000 and repeatedly print
   * groups of (up to) 9 digits. It's conceptually simple,
   * but requires a (unsigned long long) / 1000000000 division.
   *
   * Second algorithm splits 64-bit unsigned long long into 16-bit chunks,
   * manipulates them cleverly and generates groups of 4 decimal digits.
   * It so happens that it does NOT require long long division.
   *
   * If long is > 32 bits, division of 64-bit values is relatively easy,
   * and we will use the first algorithm.
   * If long long is > 64 bits (strange architecture with VERY large long long),
   * second algorithm can't be used, and we again use the first one.
   *
   * Else (if long is 32 bits and long long is 64 bits) we use second one.
   */

  #if BITS_PER_LONG != 32 || BITS_PER_LONG_LONG != 64
  
  /* First algorithm: generic */
  
  static
  char *put_dec(char *buf, unsigned long long n)
  {
  	if (n >= 100*1000*1000) {
  		while (n >= 1000*1000*1000)
  			buf = put_dec_full9(buf, do_div(n, 1000*1000*1000));
  		if (n >= 100*1000*1000)
  			return put_dec_full9(buf, n);
  	}
  	return put_dec_trunc8(buf, n);

  }

  
  #else
  
  /* Second algorithm: valid only for 64-bit long longs */

  static noinline_for_stack

  char *put_dec_full4(char *buf, unsigned q)

  {

  	unsigned r;
  	r      = (q * 0xcccd) >> 19;
  	*buf++ = (q - 10 * r) + '0';
  	q      = (r * 0x199a) >> 16;
  	*buf++ = (r - 10 * q)  + '0';
  	r      = (q * 0xcd) >> 11;
  	*buf++ = (q - 10 * r)  + '0';
  	*buf++ = r + '0';
  	return buf;

  }

  /* Based on code by Douglas W. Jones found at
   * <http://www.cs.uiowa.edu/~jones/bcd/decimal.html#sixtyfour>
   * (with permission from the author).
   * Performs no 64-bit division and hence should be fast on 32-bit machines.
   */
  static
  char *put_dec(char *buf, unsigned long long n)
  {
  	uint32_t d3, d2, d1, q, h;
  
  	if (n < 100*1000*1000)
  		return put_dec_trunc8(buf, n);
  
  	d1  = ((uint32_t)n >> 16); /* implicit "& 0xffff" */
  	h   = (n >> 32);
  	d2  = (h      ) & 0xffff;
  	d3  = (h >> 16); /* implicit "& 0xffff" */
  
  	q   = 656 * d3 + 7296 * d2 + 5536 * d1 + ((uint32_t)n & 0xffff);
  
  	buf = put_dec_full4(buf, q % 10000);
  	q   = q / 10000;
  
  	d1  = q + 7671 * d3 + 9496 * d2 + 6 * d1;
  	buf = put_dec_full4(buf, d1 % 10000);
  	q   = d1 / 10000;
  
  	d2  = q + 4749 * d3 + 42 * d2;
  	buf = put_dec_full4(buf, d2 % 10000);
  	q   = d2 / 10000;
  
  	d3  = q + 281 * d3;
  	if (!d3)
  		goto done;
  	buf = put_dec_full4(buf, d3 % 10000);
  	q   = d3 / 10000;
  	if (!q)
  		goto done;
  	buf = put_dec_full4(buf, q);
   done:
  	while (buf[-1] == '0')
  		--buf;
  
  	return buf;
  }
  
  #endif

  /*
   * Convert passed number to decimal string.
   * Returns the length of string.  On buffer overflow, returns 0.
   *
   * If speed is not important, use snprintf(). It's easy to read the code.
   */
  int num_to_str(char *buf, int size, unsigned long long num)
  {

  	char tmp[sizeof(num) * 3];

  	int idx, len;

  	/* put_dec() may work incorrectly for num = 0 (generate "", not "0") */
  	if (num <= 9) {
  		tmp[0] = '0' + num;
  		len = 1;
  	} else {
  		len = put_dec(tmp, num) - tmp;
  	}

  
  	if (len > size)
  		return 0;
  	for (idx = 0; idx < len; ++idx)
  		buf[idx] = tmp[len - idx - 1];

  	return len;

  }

  #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 */

  #define SMALL	32		/* use lowercase in hex (must be 32 == 0x20) */
  #define SPECIAL	64		/* prefix hex with "0x", octal with "0" */

  enum format_type {
  	FORMAT_TYPE_NONE, /* Just a string part */

  	FORMAT_TYPE_WIDTH,

  	FORMAT_TYPE_PRECISION,
  	FORMAT_TYPE_CHAR,
  	FORMAT_TYPE_STR,
  	FORMAT_TYPE_PTR,
  	FORMAT_TYPE_PERCENT_CHAR,
  	FORMAT_TYPE_INVALID,
  	FORMAT_TYPE_LONG_LONG,
  	FORMAT_TYPE_ULONG,
  	FORMAT_TYPE_LONG,

  	FORMAT_TYPE_UBYTE,
  	FORMAT_TYPE_BYTE,

  	FORMAT_TYPE_USHORT,
  	FORMAT_TYPE_SHORT,
  	FORMAT_TYPE_UINT,
  	FORMAT_TYPE_INT,
  	FORMAT_TYPE_NRCHARS,
  	FORMAT_TYPE_SIZE_T,
  	FORMAT_TYPE_PTRDIFF
  };
  
  struct printf_spec {

  	u8	type;		/* format_type enum */

  	u8	flags;		/* flags to number() */

  	u8	base;		/* number base, 8, 10 or 16 only */
  	u8	qualifier;	/* number qualifier, one of 'hHlLtzZ' */
  	s16	field_width;	/* width of output field */
  	s16	precision;	/* # of digits/chars */

  };

  static noinline_for_stack
  char *number(char *buf, char *end, unsigned long long num,
  	     struct printf_spec spec)

  {

  	/* 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;

  	int need_pfx = ((spec.flags & SPECIAL) && spec.base != 10);

  	int i;

  	bool is_zero = num == 0LL;

  	/* locase = 0 or 0x20. ORing digits or letters with 'locase'
  	 * produces same digits or (maybe lowercased) letters */

  	locase = (spec.flags & SMALL);
  	if (spec.flags & LEFT)
  		spec.flags &= ~ZEROPAD;

  	sign = 0;

  	if (spec.flags & SIGN) {

  		if ((signed long long)num < 0) {

  			sign = '-';

  			num = -(signed long long)num;

  			spec.field_width--;
  		} else if (spec.flags & PLUS) {

  			sign = '+';

  			spec.field_width--;
  		} else if (spec.flags & SPACE) {

  			sign = ' ';

  			spec.field_width--;

  		}
  	}

  	if (need_pfx) {

  		if (spec.base == 16)

  			spec.field_width -= 2;
  		else if (!is_zero)

  			spec.field_width--;

  	}

  
  	/* generate full string in tmp[], in reverse order */

  	i = 0;

  	if (num < spec.base)
  		tmp[i++] = digits[num] | locase;

  	/* Generic code, for any base:
  	else do {

  		tmp[i++] = (digits[do_div(num,base)] | locase);

  	} while (num != 0);
  	*/

  	else if (spec.base != 10) { /* 8 or 16 */
  		int mask = spec.base - 1;

  		int shift = 3;

  
  		if (spec.base == 16)
  			shift = 4;

  		do {

  			tmp[i++] = (digits[((unsigned char)num) & mask] | locase);

  			num >>= shift;
  		} while (num);

  	} else { /* base 10 */
  		i = put_dec(tmp, num) - tmp;
  	}

  
  	/* printing 100 using %2d gives "100", not "00" */

  	if (i > spec.precision)
  		spec.precision = i;

  	/* leading space padding */

  	spec.field_width -= spec.precision;
  	if (!(spec.flags & (ZEROPAD+LEFT))) {

  		while (--spec.field_width >= 0) {

  			if (buf < end)

  				*buf = ' ';
  			++buf;
  		}
  	}

  	/* sign */

  	if (sign) {

  		if (buf < end)

  			*buf = sign;
  		++buf;
  	}

  	/* "0x" / "0" prefix */
  	if (need_pfx) {

  		if (spec.base == 16 || !is_zero) {
  			if (buf < end)
  				*buf = '0';
  			++buf;
  		}

  		if (spec.base == 16) {

  			if (buf < end)

  				*buf = ('X' | locase);

  			++buf;
  		}
  	}

  	/* zero or space padding */

  	if (!(spec.flags & LEFT)) {
  		char c = (spec.flags & ZEROPAD) ? '0' : ' ';
  		while (--spec.field_width >= 0) {

  			if (buf < end)

  				*buf = c;
  			++buf;
  		}
  	}

  	/* hmm even more zero padding? */

  	while (i <= --spec.precision) {

  		if (buf < end)

  			*buf = '0';
  		++buf;
  	}

  	/* actual digits of result */
  	while (--i >= 0) {

  		if (buf < end)

  			*buf = tmp[i];
  		++buf;
  	}

  	/* trailing space padding */

  	while (--spec.field_width >= 0) {

  		if (buf < end)

  			*buf = ' ';
  		++buf;
  	}

  	return buf;
  }

  static noinline_for_stack
  char *string(char *buf, char *end, const char *s, struct printf_spec spec)

  {
  	int len, i;
  
  	if ((unsigned long)s < PAGE_SIZE)

  		s = "(null)";

  	len = strnlen(s, spec.precision);

  	if (!(spec.flags & LEFT)) {
  		while (len < spec.field_width--) {

  			if (buf < end)
  				*buf = ' ';
  			++buf;
  		}
  	}
  	for (i = 0; i < len; ++i) {
  		if (buf < end)
  			*buf = *s;
  		++buf; ++s;
  	}

  	while (len < spec.field_width--) {

  		if (buf < end)
  			*buf = ' ';
  		++buf;
  	}

  	return buf;
  }

  static noinline_for_stack
  char *symbol_string(char *buf, char *end, void *ptr,
  		    struct printf_spec spec, char ext)

  {
  	unsigned long value = (unsigned long) ptr;
  #ifdef CONFIG_KALLSYMS
  	char sym[KSYM_SYMBOL_LEN];

  	if (ext == 'B')
  		sprint_backtrace(sym, value);
  	else if (ext != 'f' && ext != 's')

  		sprint_symbol(sym, value);
  	else

  		sprint_symbol_no_offset(sym, value);

  	return string(buf, end, sym, spec);

  #else

  	spec.field_width = 2 * sizeof(void *);

  	spec.flags |= SPECIAL | SMALL | ZEROPAD;
  	spec.base = 16;

  	return number(buf, end, value, spec);

  #endif
  }

  static noinline_for_stack
  char *resource_string(char *buf, char *end, struct resource *res,
  		      struct printf_spec spec, const char *fmt)

  {
  #ifndef IO_RSRC_PRINTK_SIZE

  #define IO_RSRC_PRINTK_SIZE	6

  #endif
  
  #ifndef MEM_RSRC_PRINTK_SIZE

  #define MEM_RSRC_PRINTK_SIZE	10

  #endif

  	static const struct printf_spec io_spec = {

  		.base = 16,

  		.field_width = IO_RSRC_PRINTK_SIZE,

  		.precision = -1,
  		.flags = SPECIAL | SMALL | ZEROPAD,
  	};

  	static const struct printf_spec mem_spec = {
  		.base = 16,
  		.field_width = MEM_RSRC_PRINTK_SIZE,
  		.precision = -1,
  		.flags = SPECIAL | SMALL | ZEROPAD,
  	};

  	static const struct printf_spec bus_spec = {
  		.base = 16,
  		.field_width = 2,
  		.precision = -1,
  		.flags = SMALL | ZEROPAD,
  	};

  	static const struct printf_spec dec_spec = {

  		.base = 10,
  		.precision = -1,
  		.flags = 0,
  	};

  	static const struct printf_spec str_spec = {

  		.field_width = -1,
  		.precision = 10,
  		.flags = LEFT,
  	};

  	static const struct printf_spec flag_spec = {

  		.base = 16,
  		.precision = -1,
  		.flags = SPECIAL | SMALL,
  	};

  
  	/* 32-bit res (sizeof==4): 10 chars in dec, 10 in hex ("0x" + 8)
  	 * 64-bit res (sizeof==8): 20 chars in dec, 18 in hex ("0x" + 16) */
  #define RSRC_BUF_SIZE		((2 * sizeof(resource_size_t)) + 4)
  #define FLAG_BUF_SIZE		(2 * sizeof(res->flags))

  #define DECODED_BUF_SIZE	sizeof("[mem - 64bit pref window disabled]")

  #define RAW_BUF_SIZE		sizeof("[mem - flags 0x]")
  	char sym[max(2*RSRC_BUF_SIZE + DECODED_BUF_SIZE,
  		     2*RSRC_BUF_SIZE + FLAG_BUF_SIZE + RAW_BUF_SIZE)];

  	char *p = sym, *pend = sym + sizeof(sym);

  	int decode = (fmt[0] == 'R') ? 1 : 0;

  	const struct printf_spec *specp;

  
  	*p++ = '[';

  	if (res->flags & IORESOURCE_IO) {

  		p = string(p, pend, "io  ", str_spec);

  		specp = &io_spec;
  	} else if (res->flags & IORESOURCE_MEM) {

  		p = string(p, pend, "mem ", str_spec);

  		specp = &mem_spec;
  	} else if (res->flags & IORESOURCE_IRQ) {

  		p = string(p, pend, "irq ", str_spec);

  		specp = &dec_spec;
  	} else if (res->flags & IORESOURCE_DMA) {

  		p = string(p, pend, "dma ", str_spec);

  		specp = &dec_spec;

  	} else if (res->flags & IORESOURCE_BUS) {
  		p = string(p, pend, "bus ", str_spec);
  		specp = &bus_spec;

  	} else {

  		p = string(p, pend, "??? ", str_spec);

  		specp = &mem_spec;

  		decode = 0;

  	}

  	p = number(p, pend, res->start, *specp);

  	if (res->start != res->end) {
  		*p++ = '-';

  		p = number(p, pend, res->end, *specp);

  	}

  	if (decode) {

  		if (res->flags & IORESOURCE_MEM_64)
  			p = string(p, pend, " 64bit", str_spec);
  		if (res->flags & IORESOURCE_PREFETCH)
  			p = string(p, pend, " pref", str_spec);

  		if (res->flags & IORESOURCE_WINDOW)
  			p = string(p, pend, " window", str_spec);

  		if (res->flags & IORESOURCE_DISABLED)
  			p = string(p, pend, " disabled", str_spec);

  	} else {
  		p = string(p, pend, " flags ", str_spec);
  		p = number(p, pend, res->flags, flag_spec);

  	}

  	*p++ = ']';

  	*p = '\0';

  	return string(buf, end, sym, spec);

  }

  static noinline_for_stack

  char *hex_string(char *buf, char *end, u8 *addr, struct printf_spec spec,
  		 const char *fmt)
  {
  	int i, len = 1;		/* if we pass '%ph[CDN]', field witdh remains
  				   negative value, fallback to the default */
  	char separator;
  
  	if (spec.field_width == 0)
  		/* nothing to print */
  		return buf;
  
  	if (ZERO_OR_NULL_PTR(addr))
  		/* NULL pointer */
  		return string(buf, end, NULL, spec);
  
  	switch (fmt[1]) {
  	case 'C':
  		separator = ':';
  		break;
  	case 'D':
  		separator = '-';
  		break;
  	case 'N':
  		separator = 0;
  		break;
  	default:
  		separator = ' ';
  		break;
  	}
  
  	if (spec.field_width > 0)
  		len = min_t(int, spec.field_width, 64);
  
  	for (i = 0; i < len && buf < end - 1; i++) {
  		buf = hex_byte_pack(buf, addr[i]);
  
  		if (buf < end && separator && i != len - 1)
  			*buf++ = separator;
  	}
  
  	return buf;
  }
  
  static noinline_for_stack

  char *mac_address_string(char *buf, char *end, u8 *addr,
  			 struct printf_spec spec, const char *fmt)

  {

  	char mac_addr[sizeof("xx:xx:xx:xx:xx:xx")];

  	char *p = mac_addr;
  	int i;

  	char separator;

  	bool reversed = false;

  	switch (fmt[1]) {
  	case 'F':

  		separator = '-';

  		break;
  
  	case 'R':
  		reversed = true;
  		/* fall through */
  
  	default:

  		separator = ':';

  		break;

  	}

  
  	for (i = 0; i < 6; i++) {

  		if (reversed)
  			p = hex_byte_pack(p, addr[5 - i]);
  		else
  			p = hex_byte_pack(p, addr[i]);

  		if (fmt[0] == 'M' && i != 5)

  			*p++ = separator;

  	}
  	*p = '\0';

  	return string(buf, end, mac_addr, spec);

  }

  static noinline_for_stack
  char *ip4_string(char *p, const u8 *addr, const char *fmt)

  {
  	int i;

  	bool leading_zeros = (fmt[0] == 'i');
  	int index;
  	int step;
  
  	switch (fmt[2]) {
  	case 'h':
  #ifdef __BIG_ENDIAN
  		index = 0;
  		step = 1;
  #else
  		index = 3;
  		step = -1;
  #endif
  		break;
  	case 'l':
  		index = 3;
  		step = -1;
  		break;
  	case 'n':
  	case 'b':
  	default:
  		index = 0;
  		step = 1;
  		break;
  	}

  	for (i = 0; i < 4; i++) {
  		char temp[3];	/* hold each IP quad in reverse order */

  		int digits = put_dec_trunc8(temp, addr[index]) - temp;

  		if (leading_zeros) {
  			if (digits < 3)
  				*p++ = '0';
  			if (digits < 2)
  				*p++ = '0';
  		}
  		/* reverse the digits in the quad */
  		while (digits--)
  			*p++ = temp[digits];
  		if (i < 3)
  			*p++ = '.';

  		index += step;

  	}

  	*p = '\0';

  	return p;
  }

  static noinline_for_stack
  char *ip6_compressed_string(char *p, const char *addr)

  {

  	int i, j, range;

  	unsigned char zerolength[8];
  	int longest = 1;
  	int colonpos = -1;
  	u16 word;

  	u8 hi, lo;

  	bool needcolon = false;

  	bool useIPv4;
  	struct in6_addr in6;
  
  	memcpy(&in6, addr, sizeof(struct in6_addr));
  
  	useIPv4 = ipv6_addr_v4mapped(&in6) || ipv6_addr_is_isatap(&in6);

  
  	memset(zerolength, 0, sizeof(zerolength));
  
  	if (useIPv4)
  		range = 6;
  	else
  		range = 8;
  
  	/* find position of longest 0 run */
  	for (i = 0; i < range; i++) {
  		for (j = i; j < range; j++) {

  			if (in6.s6_addr16[j] != 0)

  				break;
  			zerolength[i]++;
  		}
  	}
  	for (i = 0; i < range; i++) {
  		if (zerolength[i] > longest) {
  			longest = zerolength[i];
  			colonpos = i;
  		}
  	}

  	if (longest == 1)		/* don't compress a single 0 */
  		colonpos = -1;

  	/* emit address */
  	for (i = 0; i < range; i++) {
  		if (i == colonpos) {
  			if (needcolon || i == 0)
  				*p++ = ':';
  			*p++ = ':';
  			needcolon = false;
  			i += longest - 1;
  			continue;
  		}
  		if (needcolon) {
  			*p++ = ':';
  			needcolon = false;
  		}
  		/* hex u16 without leading 0s */

  		word = ntohs(in6.s6_addr16[i]);

  		hi = word >> 8;
  		lo = word & 0xff;
  		if (hi) {
  			if (hi > 0x0f)

  				p = hex_byte_pack(p, hi);

  			else
  				*p++ = hex_asc_lo(hi);

  			p = hex_byte_pack(p, lo);

  		}

  		else if (lo > 0x0f)

  			p = hex_byte_pack(p, lo);

  		else
  			*p++ = hex_asc_lo(lo);
  		needcolon = true;
  	}
  
  	if (useIPv4) {
  		if (needcolon)
  			*p++ = ':';

  		p = ip4_string(p, &in6.s6_addr[12], "I4");

  	}

  	*p = '\0';

  	return p;
  }

  static noinline_for_stack
  char *ip6_string(char *p, const char *addr, const char *fmt)

  {
  	int i;

  	for (i = 0; i < 8; i++) {

  		p = hex_byte_pack(p, *addr++);
  		p = hex_byte_pack(p, *addr++);

  		if (fmt[0] == 'I' && i != 7)

  			*p++ = ':';
  	}
  	*p = '\0';

  	return p;
  }

  static noinline_for_stack
  char *ip6_addr_string(char *buf, char *end, const u8 *addr,
  		      struct printf_spec spec, const char *fmt)

  {
  	char ip6_addr[sizeof("xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255")];
  
  	if (fmt[0] == 'I' && fmt[2] == 'c')

  		ip6_compressed_string(ip6_addr, addr);

  	else

  		ip6_string(ip6_addr, addr, fmt);

  	return string(buf, end, ip6_addr, spec);

  }

  static noinline_for_stack
  char *ip4_addr_string(char *buf, char *end, const u8 *addr,
  		      struct printf_spec spec, const char *fmt)

  {

  	char ip4_addr[sizeof("255.255.255.255")];

  	ip4_string(ip4_addr, addr, fmt);

  	return string(buf, end, ip4_addr, spec);

  }

  static noinline_for_stack
  char *uuid_string(char *buf, char *end, const u8 *addr,
  		  struct printf_spec spec, const char *fmt)

  {
  	char uuid[sizeof("xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx")];
  	char *p = uuid;
  	int i;
  	static const u8 be[16] = {0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15};
  	static const u8 le[16] = {3,2,1,0,5,4,7,6,8,9,10,11,12,13,14,15};
  	const u8 *index = be;
  	bool uc = false;
  
  	switch (*(++fmt)) {
  	case 'L':
  		uc = true;		/* fall-through */
  	case 'l':
  		index = le;
  		break;
  	case 'B':
  		uc = true;
  		break;
  	}
  
  	for (i = 0; i < 16; i++) {

  		p = hex_byte_pack(p, addr[index[i]]);

  		switch (i) {
  		case 3:
  		case 5:
  		case 7:
  		case 9:
  			*p++ = '-';
  			break;
  		}
  	}
  
  	*p = 0;
  
  	if (uc) {
  		p = uuid;
  		do {
  			*p = toupper(*p);
  		} while (*(++p));
  	}
  
  	return string(buf, end, uuid, spec);
  }

  static
  char *netdev_feature_string(char *buf, char *end, const u8 *addr,
  		      struct printf_spec spec)
  {
  	spec.flags |= SPECIAL | SMALL | ZEROPAD;
  	if (spec.field_width == -1)
  		spec.field_width = 2 + 2 * sizeof(netdev_features_t);
  	spec.base = 16;
  
  	return number(buf, end, *(const netdev_features_t *)addr, spec);
  }

  int kptr_restrict __read_mostly;

  /*
   * Show a '%p' thing.  A kernel extension is that the '%p' is followed
   * by an extra set of alphanumeric characters that are extended format
   * specifiers.
   *

   * Right now we handle:
   *

   * - 'F' For symbolic function descriptor pointers with offset
   * - 'f' For simple symbolic function names without offset

   * - 'S' For symbolic direct pointers with offset
   * - 's' For symbolic direct pointers without offset

   * - 'B' For backtraced symbolic direct pointers with offset

   * - 'R' For decoded struct resource, e.g., [mem 0x0-0x1f 64bit pref]
   * - 'r' For raw struct resource, e.g., [mem 0x0-0x1f flags 0x201]

   * - 'M' For a 6-byte MAC address, it prints the address in the
   *       usual colon-separated hex notation

   * - 'm' For a 6-byte MAC address, it prints the hex address without colons

   * - 'MF' For a 6-byte MAC FDDI address, it prints the address

   *       with a dash-separated hex notation

   * - '[mM]R For a 6-byte MAC address, Reverse order (Bluetooth)

   * - 'I' [46] for IPv4/IPv6 addresses printed in the usual way
   *       IPv4 uses dot-separated decimal without leading 0's (1.2.3.4)
   *       IPv6 uses colon separated network-order 16 bit hex with leading 0's
   * - 'i' [46] for 'raw' IPv4/IPv6 addresses
   *       IPv6 omits the colons (01020304...0f)
   *       IPv4 uses dot-separated decimal with leading 0's (010.123.045.006)

   * - '[Ii]4[hnbl]' IPv4 addresses in host, network, big or little endian order

   * - 'I6c' for IPv6 addresses printed as specified by

   *       http://tools.ietf.org/html/rfc5952

   * - 'U' For a 16 byte UUID/GUID, it prints the UUID/GUID in the form
   *       "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx"
   *       Options for %pU are:
   *         b big endian lower case hex (default)
   *         B big endian UPPER case hex
   *         l little endian lower case hex
   *         L little endian UPPER case hex
   *           big endian output byte order is:
   *             [0][1][2][3]-[4][5]-[6][7]-[8][9]-[10][11][12][13][14][15]
   *           little endian output byte order is:
   *             [3][2][1][0]-[5][4]-[7][6]-[8][9]-[10][11][12][13][14][15]

   * - 'V' For a struct va_format which contains a format string * and va_list *,
   *       call vsnprintf(->format, *->va_list).
   *       Implements a "recursive vsnprintf".
   *       Do not use this feature without some mechanism to verify the
   *       correctness of the format string and va_list arguments.

   * - 'K' For a kernel pointer that should be hidden from unprivileged users

   * - 'NF' For a netdev_features_t

   * - 'h[CDN]' For a variable-length buffer, it prints it as a hex string with
   *            a certain separator (' ' by default):
   *              C colon
   *              D dash
   *              N no separator
   *            The maximum supported length is 64 bytes of the input. Consider
   *            to use print_hex_dump() for the larger input.

   *

   * Note: The difference between 'S' and 'F' is that on ia64 and ppc64
   * function pointers are really function descriptors, which contain a
   * pointer to the real address.

   */

  static noinline_for_stack
  char *pointer(const char *fmt, char *buf, char *end, void *ptr,
  	      struct printf_spec spec)

  {

  	int default_width = 2 * sizeof(void *) + (spec.flags & SPECIAL ? 2 : 0);

  	if (!ptr && *fmt != 'K') {

  		/*
  		 * Print (null) with the same width as a pointer so it makes
  		 * tabular output look nice.
  		 */
  		if (spec.field_width == -1)

  			spec.field_width = default_width;

  		return string(buf, end, "(null)", spec);

  	}

  	switch (*fmt) {
  	case 'F':

  	case 'f':

  		ptr = dereference_function_descriptor(ptr);
  		/* Fallthrough */
  	case 'S':

  	case 's':

  	case 'B':

  		return symbol_string(buf, end, ptr, spec, *fmt);

  	case 'R':

  	case 'r':

  		return resource_string(buf, end, ptr, spec, fmt);

  	case 'h':
  		return hex_string(buf, end, ptr, spec, fmt);

  	case 'M':			/* Colon separated: 00:01:02:03:04:05 */
  	case 'm':			/* Contiguous: 000102030405 */

  					/* [mM]F (FDDI) */
  					/* [mM]R (Reverse order; Bluetooth) */

  		return mac_address_string(buf, end, ptr, spec, fmt);
  	case 'I':			/* Formatted IP supported
  					 * 4:	1.2.3.4
  					 * 6:	0001:0203:...:0708
  					 * 6c:	1::708 or 1::1.2.3.4
  					 */
  	case 'i':			/* Contiguous:
  					 * 4:	001.002.003.004
  					 * 6:   000102...0f
  					 */
  		switch (fmt[1]) {
  		case '6':
  			return ip6_addr_string(buf, end, ptr, spec, fmt);
  		case '4':
  			return ip4_addr_string(buf, end, ptr, spec, fmt);
  		}

  		break;

  	case 'U':
  		return uuid_string(buf, end, ptr, spec, fmt);

  	case 'V':

  		{
  			va_list va;
  
  			va_copy(va, *((struct va_format *)ptr)->va);
  			buf += vsnprintf(buf, end > buf ? end - buf : 0,
  					 ((struct va_format *)ptr)->fmt, va);
  			va_end(va);
  			return buf;
  		}

  	case 'K':
  		/*
  		 * %pK cannot be used in IRQ context because its test
  		 * for CAP_SYSLOG would be meaningless.
  		 */

  		if (kptr_restrict && (in_irq() || in_serving_softirq() ||
  				      in_nmi())) {

  			if (spec.field_width == -1)

  				spec.field_width = default_width;

  			return string(buf, end, "pK-error", spec);

  		}

  		if (!((kptr_restrict == 0) ||
  		      (kptr_restrict == 1 &&
  		       has_capability_noaudit(current, CAP_SYSLOG))))
  			ptr = NULL;
  		break;

  	case 'N':
  		switch (fmt[1]) {
  		case 'F':
  			return netdev_feature_string(buf, end, ptr, spec);
  		}
  		break;

  	}
  	spec.flags |= SMALL;
  	if (spec.field_width == -1) {

  		spec.field_width = default_width;

  		spec.flags |= ZEROPAD;
  	}
  	spec.base = 16;
  
  	return number(buf, end, (unsigned long) ptr, spec);
  }
  
  /*
   * Helper function to decode printf style format.
   * Each call decode a token from the format and return the
   * number of characters read (or likely the delta where it wants
   * to go on the next call).
   * The decoded token is returned through the parameters
   *
   * 'h', 'l', or 'L' for integer fields
   * 'z' support added 23/7/1999 S.H.
   * 'z' changed to 'Z' --davidm 1/25/99
   * 't' added for ptrdiff_t
   *
   * @fmt: the format string
   * @type of the token returned
   * @flags: various flags such as +, -, # tokens..
   * @field_width: overwritten width
   * @base: base of the number (octal, hex, ...)
   * @precision: precision of a number
   * @qualifier: qualifier of a number (long, size_t, ...)
   */

  static noinline_for_stack
  int format_decode(const char *fmt, struct printf_spec *spec)

  {
  	const char *start = fmt;

  
  	/* we finished early by reading the field width */

  	if (spec->type == FORMAT_TYPE_WIDTH) {

  		if (spec->field_width < 0) {
  			spec->field_width = -spec->field_width;
  			spec->flags |= LEFT;
  		}
  		spec->type = FORMAT_TYPE_NONE;
  		goto precision;
  	}
  
  	/* we finished early by reading the precision */
  	if (spec->type == FORMAT_TYPE_PRECISION) {
  		if (spec->precision < 0)
  			spec->precision = 0;
  
  		spec->type = FORMAT_TYPE_NONE;
  		goto qualifier;
  	}
  
  	/* By default */
  	spec->type = FORMAT_TYPE_NONE;
  
  	for (; *fmt ; ++fmt) {
  		if (*fmt == '%')
  			break;
  	}
  
  	/* Return the current non-format string */
  	if (fmt != start || !*fmt)
  		return fmt - start;
  
  	/* Process flags */
  	spec->flags = 0;
  
  	while (1) { /* this also skips first '%' */
  		bool found = true;
  
  		++fmt;
  
  		switch (*fmt) {
  		case '-': spec->flags |= LEFT;    break;
  		case '+': spec->flags |= PLUS;    break;
  		case ' ': spec->flags |= SPACE;   break;
  		case '#': spec->flags |= SPECIAL; break;
  		case '0': spec->flags |= ZEROPAD; break;
  		default:  found = false;
  		}
  
  		if (!found)
  			break;
  	}
  
  	/* get field width */
  	spec->field_width = -1;
  
  	if (isdigit(*fmt))
  		spec->field_width = skip_atoi(&fmt);
  	else if (*fmt == '*') {
  		/* it's the next argument */

  		spec->type = FORMAT_TYPE_WIDTH;

  		return ++fmt - start;
  	}
  
  precision:
  	/* get the precision */
  	spec->precision = -1;
  	if (*fmt == '.') {
  		++fmt;
  		if (isdigit(*fmt)) {
  			spec->precision = skip_atoi(&fmt);
  			if (spec->precision < 0)
  				spec->precision = 0;
  		} else if (*fmt == '*') {
  			/* it's the next argument */

  			spec->type = FORMAT_TYPE_PRECISION;

  			return ++fmt - start;
  		}
  	}
  
  qualifier:
  	/* get the conversion qualifier */
  	spec->qualifier = -1;

  	if (*fmt == 'h' || _tolower(*fmt) == 'l' ||
  	    _tolower(*fmt) == 'z' || *fmt == 't') {

  		spec->qualifier = *fmt++;
  		if (unlikely(spec->qualifier == *fmt)) {
  			if (spec->qualifier == 'l') {
  				spec->qualifier = 'L';
  				++fmt;
  			} else if (spec->qualifier == 'h') {
  				spec->qualifier = 'H';
  				++fmt;
  			}

  		}
  	}
  
  	/* default base */
  	spec->base = 10;
  	switch (*fmt) {
  	case 'c':
  		spec->type = FORMAT_TYPE_CHAR;
  		return ++fmt - start;
  
  	case 's':
  		spec->type = FORMAT_TYPE_STR;
  		return ++fmt - start;
  
  	case 'p':
  		spec->type = FORMAT_TYPE_PTR;
  		return fmt - start;
  		/* skip alnum */
  
  	case 'n':
  		spec->type = FORMAT_TYPE_NRCHARS;
  		return ++fmt - start;
  
  	case '%':
  		spec->type = FORMAT_TYPE_PERCENT_CHAR;
  		return ++fmt - start;
  
  	/* integer number formats - set up the flags and "break" */
  	case 'o':
  		spec->base = 8;
  		break;
  
  	case 'x':
  		spec->flags |= SMALL;
  
  	case 'X':
  		spec->base = 16;
  		break;
  
  	case 'd':
  	case 'i':

  		spec->flags |= SIGN;

  	case 'u':

  		break;

  
  	default:
  		spec->type = FORMAT_TYPE_INVALID;
  		return fmt - start;

  	}

  
  	if (spec->qualifier == 'L')
  		spec->type = FORMAT_TYPE_LONG_LONG;
  	else if (spec->qualifier == 'l') {

  		if (spec->flags & SIGN)

  			spec->type = FORMAT_TYPE_LONG;
  		else
  			spec->type = FORMAT_TYPE_ULONG;

  	} else if (_tolower(spec->qualifier) == 'z') {

  		spec->type = FORMAT_TYPE_SIZE_T;
  	} else if (spec->qualifier == 't') {
  		spec->type = FORMAT_TYPE_PTRDIFF;

  	} else if (spec->qualifier == 'H') {
  		if (spec->flags & SIGN)
  			spec->type = FORMAT_TYPE_BYTE;
  		else
  			spec->type = FORMAT_TYPE_UBYTE;

  	} else if (spec->qualifier == 'h') {

  		if (spec->flags & SIGN)

  			spec->type = FORMAT_TYPE_SHORT;
  		else
  			spec->type = FORMAT_TYPE_USHORT;
  	} else {

  		if (spec->flags & SIGN)

  			spec->type = FORMAT_TYPE_INT;
  		else
  			spec->type = FORMAT_TYPE_UINT;

  	}

  
  	return ++fmt - start;

  }

  /**
   * 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
   *

   * This function follows C99 vsnprintf, but has some extensions:

   * %pS output the name of a text symbol with offset
   * %ps output the name of a text symbol without offset

   * %pF output the name of a function pointer with its offset
   * %pf output the name of a function pointer without its offset

   * %pB output the name of a backtrace symbol with its offset

   * %pR output the address range in a struct resource with decoded flags
   * %pr output the address range in a struct resource with raw flags
   * %pM output a 6-byte MAC address with colons
   * %pm output a 6-byte MAC address without colons
   * %pI4 print an IPv4 address without leading zeros
   * %pi4 print an IPv4 address with leading zeros
   * %pI6 print an IPv6 address with colons
   * %pi6 print an IPv6 address without colons

   * %pI6c print an IPv6 address as specified by RFC 5952

   * %pU[bBlL] print a UUID/GUID in big or little endian using lower or upper
   *   case.

   * %*ph[CDN] a variable-length hex string with a separator (supports up to 64
   *           bytes of the input)

   * %n is ignored

   *

   * ** Please update Documentation/printk-formats.txt when making changes **
   *

   * 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

   * (not including the trailing '\0'), use vscnprintf(). If the

   * return is greater than or equal to @size, the resulting
   * string is truncated.
   *

   * If you're not already dealing with a va_list consider using snprintf().

   */
  int vsnprintf(char *buf, size_t size, const char *fmt, va_list args)
  {

  	unsigned long long num;

  	char *str, *end;

  	struct printf_spec spec = {0};

  	/* Reject out-of-range values early.  Large positive sizes are
  	   used for unknown buffer sizes. */

  	if (WARN_ON_ONCE((int) size < 0))

  		return 0;

  
  	str = buf;

  	end = buf + size;

  	/* Make sure end is always >= buf */
  	if (end < buf) {
  		end = ((void *)-1);
  		size = end - buf;

  	}

  	while (*fmt) {
  		const char *old_fmt = fmt;

  		int read = format_decode(fmt, &spec);

  		fmt += read;

  		switch (spec.type) {
  		case FORMAT_TYPE_NONE: {
  			int copy = read;
  			if (str < end) {
  				if (copy > end - str)
  					copy = end - str;
  				memcpy(str, old_fmt, copy);

  			}

  			str += read;
  			break;

  		}

  		case FORMAT_TYPE_WIDTH:

  			spec.field_width = va_arg(args, int);
  			break;

  		case FORMAT_TYPE_PRECISION:
  			spec.precision = va_arg(args, int);
  			break;

  		case FORMAT_TYPE_CHAR: {
  			char c;

  			if (!(spec.flags & LEFT)) {
  				while (--spec.field_width > 0) {

  					if (str < end)

  						*str = ' ';
  					++str;

  				}
  			}
  			c = (unsigned char) va_arg(args, int);
  			if (str < end)
  				*str = c;
  			++str;
  			while (--spec.field_width > 0) {

  				if (str < end)

  					*str = ' ';

  				++str;

  			}
  			break;

  		}

  		case FORMAT_TYPE_STR:
  			str = string(str, end, va_arg(args, char *), spec);
  			break;

  		case FORMAT_TYPE_PTR:
  			str = pointer(fmt+1, str, end, va_arg(args, void *),
  				      spec);
  			while (isalnum(*fmt))
  				fmt++;
  			break;

  		case FORMAT_TYPE_PERCENT_CHAR:
  			if (str < end)
  				*str = '%';
  			++str;
  			break;

  		case FORMAT_TYPE_INVALID:
  			if (str < end)
  				*str = '%';
  			++str;

  			break;
  
  		case FORMAT_TYPE_NRCHARS: {

  			u8 qualifier = spec.qualifier;

  
  			if (qualifier == 'l') {
  				long *ip = va_arg(args, long *);
  				*ip = (str - buf);

  			} else if (_tolower(qualifier) == 'z') {

  				size_t *ip = va_arg(args, size_t *);
  				*ip = (str - buf);
  			} else {
  				int *ip = va_arg(args, int *);
  				*ip = (str - buf);
  			}
  			break;

  		}

  
  		default:
  			switch (spec.type) {
  			case FORMAT_TYPE_LONG_LONG:
  				num = va_arg(args, long long);
  				break;
  			case FORMAT_TYPE_ULONG:
  				num = va_arg(args, unsigned long);
  				break;
  			case FORMAT_TYPE_LONG:
  				num = va_arg(args, long);
  				break;
  			case FORMAT_TYPE_SIZE_T:
  				num = va_arg(args, size_t);
  				break;
  			case FORMAT_TYPE_PTRDIFF:
  				num = va_arg(args, ptrdiff_t);
  				break;

  			case FORMAT_TYPE_UBYTE:
  				num = (unsigned char) va_arg(args, int);
  				break;
  			case FORMAT_TYPE_BYTE:
  				num = (signed char) va_arg(args, int);
  				break;

  			case FORMAT_TYPE_USHORT:
  				num = (unsigned short) va_arg(args, int);
  				break;
  			case FORMAT_TYPE_SHORT:
  				num = (short) va_arg(args, int);
  				break;

  			case FORMAT_TYPE_INT:
  				num = (int) va_arg(args, int);

  				break;
  			default:
  				num = va_arg(args, unsigned int);
  			}
  
  			str = number(str, end, num, spec);

  		}

  	}

  	if (size > 0) {
  		if (str < end)
  			*str = '\0';
  		else

  			end[-1] = '\0';

  	}

  	/* the trailing null byte doesn't count towards the total */

  	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.
   *

   * If you're not already dealing with a va_list consider using scnprintf().

   *
   * See the vsnprintf() documentation for format string extensions over C99.

   */
  int vscnprintf(char *buf, size_t size, const char *fmt, va_list args)
  {
  	int i;

  	i = vsnprintf(buf, size, fmt, args);

  	if (likely(i < size))
  		return i;
  	if (size != 0)
  		return size - 1;
  	return 0;

  }

  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.

   *
   * See the vsnprintf() documentation for format string extensions over C99.

   */

  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

   * the trailing '\0'. If @size is == 0 the function returns 0.

   */

  int scnprintf(char *buf, size_t size, const char *fmt, ...)

  {
  	va_list args;
  	int i;
  
  	va_start(args, fmt);

  	i = vscnprintf(buf, size, fmt, args);

  	va_end(args);

  	return 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

   * into @buf. Use vsnprintf() or vscnprintf() in order to avoid

   * buffer overflows.
   *

   * If you're not already dealing with a va_list consider using sprintf().

   *
   * See the vsnprintf() documentation for format string extensions over C99.

   */
  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

   * into @buf. Use snprintf() or scnprintf() in order to avoid

   * buffer overflows.

   *
   * See the vsnprintf() documentation for format string extensions over C99.

   */

  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);

  #ifdef CONFIG_BINARY_PRINTF
  /*
   * bprintf service:
   * vbin_printf() - VA arguments to binary data
   * bstr_printf() - Binary data to text string
   */
  
  /**
   * vbin_printf - Parse a format string and place args' binary value in a buffer
   * @bin_buf: The buffer to place args' binary value
   * @size: The size of the buffer(by words(32bits), not characters)
   * @fmt: The format string to use
   * @args: Arguments for the format string
   *
   * The format follows C99 vsnprintf, except %n is ignored, and its argument
   * is skiped.
   *
   * The return value is the number of words(32bits) which would be generated for
   * the given input.
   *
   * NOTE:
   * If the return value is greater than @size, the resulting bin_buf is NOT
   * valid for bstr_printf().
   */
  int vbin_printf(u32 *bin_buf, size_t size, const char *fmt, va_list args)
  {

  	struct printf_spec spec = {0};

  	char *str, *end;

  
  	str = (char *)bin_buf;
  	end = (char *)(bin_buf + size);
  
  #define save_arg(type)							\
  do {									\
  	if (sizeof(type) == 8) {					\
  		unsigned long long value;				\
  		str = PTR_ALIGN(str, sizeof(u32));			\
  		value = va_arg(args, unsigned long long);		\
  		if (str + sizeof(type) <= end) {			\
  			*(u32 *)str = *(u32 *)&value;			\
  			*(u32 *)(str + 4) = *((u32 *)&value + 1);	\
  		}							\
  	} else {							\
  		unsigned long value;					\
  		str = PTR_ALIGN(str, sizeof(type));			\
  		value = va_arg(args, int);				\
  		if (str + sizeof(type) <= end)				\
  			*(typeof(type) *)str = (type)value;		\
  	}								\
  	str += sizeof(type);						\
  } while (0)

  	while (*fmt) {

  		int read = format_decode(fmt, &spec);

  		fmt += read;

  		switch (spec.type) {
  		case FORMAT_TYPE_NONE:

  		case FORMAT_TYPE_INVALID:
  		case FORMAT_TYPE_PERCENT_CHAR:

  			break;

  		case FORMAT_TYPE_WIDTH:

  		case FORMAT_TYPE_PRECISION:
  			save_arg(int);
  			break;
  
  		case FORMAT_TYPE_CHAR:

  			save_arg(char);

  			break;
  
  		case FORMAT_TYPE_STR: {

  			const char *save_str = va_arg(args, char *);
  			size_t len;

  			if ((unsigned long)save_str > (unsigned long)-PAGE_SIZE
  					|| (unsigned long)save_str < PAGE_SIZE)

  				save_str = "(null)";

  			len = strlen(save_str) + 1;
  			if (str + len < end)
  				memcpy(str, save_str, len);
  			str += len;

  			break;

  		}

  
  		case FORMAT_TYPE_PTR:

  			save_arg(void *);
  			/* skip all alphanumeric pointer suffixes */

  			while (isalnum(*fmt))

  				fmt++;

  			break;

  		case FORMAT_TYPE_NRCHARS: {

  			/* skip %n 's argument */

  			u8 qualifier = spec.qualifier;

  			void *skip_arg;
  			if (qualifier == 'l')
  				skip_arg = va_arg(args, long *);

  			else if (_tolower(qualifier) == 'z')

  				skip_arg = va_arg(args, size_t *);
  			else
  				skip_arg = va_arg(args, int *);

  			break;

  		}

  
  		default:
  			switch (spec.type) {
  
  			case FORMAT_TYPE_LONG_LONG:

  				save_arg(long long);

  				break;
  			case FORMAT_TYPE_ULONG:
  			case FORMAT_TYPE_LONG:

  				save_arg(unsigned long);

  				break;
  			case FORMAT_TYPE_SIZE_T:

  				save_arg(size_t);

  				break;
  			case FORMAT_TYPE_PTRDIFF:

  				save_arg(ptrdiff_t);

  				break;

  			case FORMAT_TYPE_UBYTE:
  			case FORMAT_TYPE_BYTE:
  				save_arg(char);
  				break;

  			case FORMAT_TYPE_USHORT:
  			case FORMAT_TYPE_SHORT:

  				save_arg(short);

  				break;
  			default:

  				save_arg(int);

  			}

  		}
  	}

  	return (u32 *)(PTR_ALIGN(str, sizeof(u32))) - bin_buf;

  #undef save_arg

  }
  EXPORT_SYMBOL_GPL(vbin_printf);
  
  /**
   * bstr_printf - Format a string from binary arguments 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
   * @bin_buf: Binary arguments for the format string
   *
   * This function like C99 vsnprintf, but the difference is that vsnprintf gets
   * arguments from stack, and bstr_printf gets arguments from @bin_buf which is
   * a binary buffer that generated by vbin_printf.
   *
   * The format follows C99 vsnprintf, but has some extensions:

   *  see vsnprintf comment for details.

   *
   * 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
   * (not including the trailing '\0'), use vscnprintf(). If the
   * return is greater than or equal to @size, the resulting
   * string is truncated.
   */
  int bstr_printf(char *buf, size_t size, const char *fmt, const u32 *bin_buf)
  {

  	struct printf_spec spec = {0};

  	char *str, *end;
  	const char *args = (const char *)bin_buf;

  	if (WARN_ON_ONCE((int) size < 0))

  		return 0;

  
  	str = buf;
  	end = buf + size;
  
  #define get_arg(type)							\
  ({									\
  	typeof(type) value;						\
  	if (sizeof(type) == 8) {					\
  		args = PTR_ALIGN(args, sizeof(u32));			\
  		*(u32 *)&value = *(u32 *)args;				\
  		*((u32 *)&value + 1) = *(u32 *)(args + 4);		\
  	} else {							\
  		args = PTR_ALIGN(args, sizeof(type));			\
  		value = *(typeof(type) *)args;				\
  	}								\
  	args += sizeof(type);						\
  	value;								\
  })
  
  	/* Make sure end is always >= buf */
  	if (end < buf) {
  		end = ((void *)-1);
  		size = end - buf;
  	}

  	while (*fmt) {

  		const char *old_fmt = fmt;

  		int read = format_decode(fmt, &spec);

  		fmt += read;

  		switch (spec.type) {
  		case FORMAT_TYPE_NONE: {
  			int copy = read;
  			if (str < end) {
  				if (copy > end - str)
  					copy = end - str;
  				memcpy(str, old_fmt, copy);

  			}

  			str += read;
  			break;

  		}

  		case FORMAT_TYPE_WIDTH:

  			spec.field_width = get_arg(int);
  			break;

  		case FORMAT_TYPE_PRECISION:
  			spec.precision = get_arg(int);
  			break;

  		case FORMAT_TYPE_CHAR: {
  			char c;

  			if (!(spec.flags & LEFT)) {
  				while (--spec.field_width > 0) {

  					if (str < end)
  						*str = ' ';
  					++str;
  				}
  			}
  			c = (unsigned char) get_arg(char);
  			if (str < end)
  				*str = c;
  			++str;

  			while (--spec.field_width > 0) {

  				if (str < end)
  					*str = ' ';
  				++str;
  			}

  			break;

  		}

  		case FORMAT_TYPE_STR: {

  			const char *str_arg = args;

  			args += strlen(str_arg) + 1;