/*
   *  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/clk.h>

  #include <linux/clk-provider.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/math64.h>

  #include <linux/uaccess.h>

  #include <linux/ioport.h>

  #include <linux/dcache.h>

  #include <linux/cred.h>

  #include <linux/uuid.h>

  #include <net/addrconf.h>

  #ifdef CONFIG_BLOCK
  #include <linux/blkdev.h>
  #endif

  #include "../mm/internal.h"	/* For the trace_print_flags arrays */

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

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

  #include <asm/byteorder.h>	/* cpu_to_le16 */

  #include <linux/string_helpers.h>

  #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

   *
   * This function is obsolete. Please use kstrtoull instead.

   */

  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

   *
   * This function is obsolete. Please use kstrtoul instead.

   */

  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

   *
   * This function is obsolete. Please use kstrtol instead.

   */

  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

   *
   * This function is obsolete. Please use kstrtoll instead.

   */

  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;

  	do {

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

  	} while (isdigit(**s));

  	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 by emitting
   * two characters at a time, using a 200 byte lookup table. This
   * roughly halves the number of multiplications compared to computing
   * the digits one at a time. Implementation strongly inspired by the
   * previous version, which in turn used ideas described at
   * <http://www.cs.uiowa.edu/~jones/bcd/divide.html> (with permission
   * from the author, Douglas W. Jones).
   *
   * It turns out there is precisely one 26 bit fixed-point
   * approximation a of 64/100 for which x/100 == (x * (u64)a) >> 32
   * holds for all x in [0, 10^8-1], namely a = 0x28f5c29. The actual
   * range happens to be somewhat larger (x <= 1073741898), but that's
   * irrelevant for our purpose.
   *
   * For dividing a number in the range [10^4, 10^6-1] by 100, we still
   * need a 32x32->64 bit multiply, so we simply use the same constant.
   *
   * For dividing a number in the range [100, 10^4-1] by 100, there are
   * several options. The simplest is (x * 0x147b) >> 19, which is valid
   * for all x <= 43698.

   */

  static const u16 decpair[100] = {
  #define _(x) (__force u16) cpu_to_le16(((x % 10) | ((x / 10) << 8)) + 0x3030)
  	_( 0), _( 1), _( 2), _( 3), _( 4), _( 5), _( 6), _( 7), _( 8), _( 9),
  	_(10), _(11), _(12), _(13), _(14), _(15), _(16), _(17), _(18), _(19),
  	_(20), _(21), _(22), _(23), _(24), _(25), _(26), _(27), _(28), _(29),
  	_(30), _(31), _(32), _(33), _(34), _(35), _(36), _(37), _(38), _(39),
  	_(40), _(41), _(42), _(43), _(44), _(45), _(46), _(47), _(48), _(49),
  	_(50), _(51), _(52), _(53), _(54), _(55), _(56), _(57), _(58), _(59),
  	_(60), _(61), _(62), _(63), _(64), _(65), _(66), _(67), _(68), _(69),
  	_(70), _(71), _(72), _(73), _(74), _(75), _(76), _(77), _(78), _(79),
  	_(80), _(81), _(82), _(83), _(84), _(85), _(86), _(87), _(88), _(89),
  	_(90), _(91), _(92), _(93), _(94), _(95), _(96), _(97), _(98), _(99),
  #undef _
  };
  
  /*
   * This will print a single '0' even if r == 0, since we would

   * immediately jump to out_r where two 0s would be written but only
   * one of them accounted for in buf. This is needed by ip4_string
   * below. All other callers pass a non-zero value of r.

  */

  static noinline_for_stack

  char *put_dec_trunc8(char *buf, unsigned r)

  {

  	unsigned q;
  
  	/* 1 <= r < 10^8 */
  	if (r < 100)
  		goto out_r;
  
  	/* 100 <= r < 10^8 */
  	q = (r * (u64)0x28f5c29) >> 32;
  	*((u16 *)buf) = decpair[r - 100*q];
  	buf += 2;
  
  	/* 1 <= q < 10^6 */
  	if (q < 100)
  		goto out_q;
  
  	/*  100 <= q < 10^6 */
  	r = (q * (u64)0x28f5c29) >> 32;
  	*((u16 *)buf) = decpair[q - 100*r];
  	buf += 2;
  
  	/* 1 <= r < 10^4 */
  	if (r < 100)
  		goto out_r;
  
  	/* 100 <= r < 10^4 */
  	q = (r * 0x147b) >> 19;
  	*((u16 *)buf) = decpair[r - 100*q];
  	buf += 2;
  out_q:
  	/* 1 <= q < 100 */
  	r = q;
  out_r:
  	/* 1 <= r < 100 */
  	*((u16 *)buf) = decpair[r];

  	buf += r < 10 ? 1 : 2;

  	return buf;
  }

  #if BITS_PER_LONG == 64 && BITS_PER_LONG_LONG == 64

  static noinline_for_stack

  char *put_dec_full8(char *buf, unsigned r)

  {

  	unsigned q;

  	/* 0 <= r < 10^8 */
  	q = (r * (u64)0x28f5c29) >> 32;
  	*((u16 *)buf) = decpair[r - 100*q];
  	buf += 2;

  	/* 0 <= q < 10^6 */
  	r = (q * (u64)0x28f5c29) >> 32;
  	*((u16 *)buf) = decpair[q - 100*r];
  	buf += 2;

  	/* 0 <= r < 10^4 */
  	q = (r * 0x147b) >> 19;
  	*((u16 *)buf) = decpair[r - 100*q];
  	buf += 2;

  	/* 0 <= q < 100 */
  	*((u16 *)buf) = decpair[q];
  	buf += 2;
  	return buf;
  }

  static noinline_for_stack

  char *put_dec(char *buf, unsigned long long n)
  {

  	if (n >= 100*1000*1000)
  		buf = put_dec_full8(buf, do_div(n, 100*1000*1000));
  	/* 1 <= n <= 1.6e11 */
  	if (n >= 100*1000*1000)
  		buf = put_dec_full8(buf, do_div(n, 100*1000*1000));
  	/* 1 <= n < 1e8 */

  	return put_dec_trunc8(buf, n);

  }

  #elif BITS_PER_LONG == 32 && BITS_PER_LONG_LONG == 64

  static void
  put_dec_full4(char *buf, unsigned r)

  {

  	unsigned q;
  
  	/* 0 <= r < 10^4 */
  	q = (r * 0x147b) >> 19;
  	*((u16 *)buf) = decpair[r - 100*q];
  	buf += 2;
  	/* 0 <= q < 100 */
  	*((u16 *)buf) = decpair[q];

  }
  
  /*
   * Call put_dec_full4 on x % 10000, return x / 10000.
   * The approximation x/10000 == (x * 0x346DC5D7) >> 43
   * holds for all x < 1,128,869,999.  The largest value this
   * helper will ever be asked to convert is 1,125,520,955.

   * (second call in the put_dec code, assuming n is all-ones).

   */

  static noinline_for_stack

  unsigned put_dec_helper4(char *buf, unsigned x)
  {
          uint32_t q = (x * (uint64_t)0x346DC5D7) >> 43;
  
          put_dec_full4(buf, x - q * 10000);
          return q;

  }

  /* 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" */

  	/* n = 2^48 d3 + 2^32 d2 + 2^16 d1 + d0
  	     = 281_4749_7671_0656 d3 + 42_9496_7296 d2 + 6_5536 d1 + d0 */

  	q   = 656 * d3 + 7296 * d2 + 5536 * d1 + ((uint32_t)n & 0xffff);

  	q = put_dec_helper4(buf, q);
  
  	q += 7671 * d3 + 9496 * d2 + 6 * d1;
  	q = put_dec_helper4(buf+4, q);
  
  	q += 4749 * d3 + 42 * d2;
  	q = put_dec_helper4(buf+8, q);

  	q += 281 * d3;
  	buf += 12;
  	if (q)
  		buf = put_dec_trunc8(buf, q);
  	else 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)
  {

  	/* put_dec requires 2-byte alignment of the buffer. */
  	char tmp[sizeof(num) * 3] __aligned(2);

  	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 SIGN	1		/* unsigned/signed, must be 1 */

  #define LEFT	2		/* left justified */

  #define PLUS	4		/* show plus */
  #define SPACE	8		/* space if plus */

  #define ZEROPAD	16		/* pad with zero, must be 16 == '0' - ' ' */

  #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_SIZE_T,
  	FORMAT_TYPE_PTRDIFF
  };
  
  struct printf_spec {

  	unsigned int	type:8;		/* format_type enum */
  	signed int	field_width:24;	/* width of output field */
  	unsigned int	flags:8;	/* flags to number() */
  	unsigned int	base:8;		/* number base, 8, 10 or 16 only */
  	signed int	precision:16;	/* # of digits/chars */
  } __packed;

  #define FIELD_WIDTH_MAX ((1 << 23) - 1)
  #define PRECISION_MAX ((1 << 15) - 1)

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

  {

  	/* put_dec requires 2-byte alignment of the buffer. */
  	char tmp[3 * sizeof(num)] __aligned(2);

  	char sign;
  	char locase;

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

  	int i;

  	bool is_zero = num == 0LL;

  	int field_width = spec.field_width;
  	int precision = spec.precision;

  	BUILD_BUG_ON(sizeof(struct printf_spec) != 8);

  	/* 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;

  			field_width--;

  		} else if (spec.flags & PLUS) {

  			sign = '+';

  			field_width--;

  		} else if (spec.flags & SPACE) {

  			sign = ' ';

  			field_width--;

  		}
  	}

  	if (need_pfx) {

  		if (spec.base == 16)

  			field_width -= 2;

  		else if (!is_zero)

  			field_width--;

  	}

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

  	i = 0;

  	if (num < spec.base)

  		tmp[i++] = hex_asc_upper[num] | locase;

  	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++] = (hex_asc_upper[((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 > precision)
  		precision = i;

  	/* leading space padding */

  	field_width -= precision;

  	if (!(spec.flags & (ZEROPAD | LEFT))) {

  		while (--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);
  		BUILD_BUG_ON(' ' + ZEROPAD != '0');

  		while (--field_width >= 0) {

  			if (buf < end)

  				*buf = c;
  			++buf;
  		}
  	}

  	/* hmm even more zero padding? */

  	while (i <= --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 (--field_width >= 0) {

  		if (buf < end)

  			*buf = ' ';
  		++buf;
  	}

  	return buf;
  }

  static noinline_for_stack
  char *special_hex_number(char *buf, char *end, unsigned long long num, int size)
  {
  	struct printf_spec spec;
  
  	spec.type = FORMAT_TYPE_PTR;
  	spec.field_width = 2 + 2 * size;	/* 0x + hex */
  	spec.flags = SPECIAL | SMALL | ZEROPAD;
  	spec.base = 16;
  	spec.precision = -1;
  
  	return number(buf, end, num, spec);
  }

  static void move_right(char *buf, char *end, unsigned len, unsigned spaces)

  {
  	size_t size;
  	if (buf >= end)	/* nowhere to put anything */
  		return;
  	size = end - buf;
  	if (size <= spaces) {
  		memset(buf, ' ', size);
  		return;
  	}
  	if (len) {
  		if (len > size - spaces)
  			len = size - spaces;
  		memmove(buf + spaces, buf, len);
  	}
  	memset(buf, ' ', spaces);
  }

  /*
   * Handle field width padding for a string.
   * @buf: current buffer position
   * @n: length of string
   * @end: end of output buffer
   * @spec: for field width and flags
   * Returns: new buffer position after padding.
   */
  static noinline_for_stack
  char *widen_string(char *buf, int n, char *end, struct printf_spec spec)
  {
  	unsigned spaces;
  
  	if (likely(n >= spec.field_width))
  		return buf;
  	/* we want to pad the sucker */
  	spaces = spec.field_width - n;
  	if (!(spec.flags & LEFT)) {
  		move_right(buf - n, end, n, spaces);
  		return buf + spaces;
  	}
  	while (spaces--) {
  		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 = 0;
  	size_t lim = spec.precision;

  
  	if ((unsigned long)s < PAGE_SIZE)
  		s = "(null)";

  	while (lim--) {
  		char c = *s++;
  		if (!c)
  			break;

  		if (buf < end)

  			*buf = c;

  		++buf;

  		++len;

  	}

  	return widen_string(buf, len, end, spec);

  }
  
  static noinline_for_stack

  char *dentry_name(char *buf, char *end, const struct dentry *d, struct printf_spec spec,
  		  const char *fmt)
  {
  	const char *array[4], *s;
  	const struct dentry *p;
  	int depth;
  	int i, n;
  
  	switch (fmt[1]) {
  		case '2': case '3': case '4':
  			depth = fmt[1] - '0';
  			break;
  		default:
  			depth = 1;
  	}
  
  	rcu_read_lock();
  	for (i = 0; i < depth; i++, d = p) {
  		p = ACCESS_ONCE(d->d_parent);
  		array[i] = ACCESS_ONCE(d->d_name.name);
  		if (p == d) {
  			if (i)
  				array[i] = "";
  			i++;
  			break;
  		}
  	}
  	s = array[--i];
  	for (n = 0; n != spec.precision; n++, buf++) {
  		char c = *s++;
  		if (!c) {
  			if (!i)
  				break;
  			c = '/';
  			s = array[--i];
  		}
  		if (buf < end)
  			*buf = c;
  	}
  	rcu_read_unlock();

  	return widen_string(buf, n, end, spec);

  }

  #ifdef CONFIG_BLOCK
  static noinline_for_stack
  char *bdev_name(char *buf, char *end, struct block_device *bdev,
  		struct printf_spec spec, const char *fmt)
  {
  	struct gendisk *hd = bdev->bd_disk;
  	
  	buf = string(buf, end, hd->disk_name, spec);
  	if (bdev->bd_part->partno) {
  		if (isdigit(hd->disk_name[strlen(hd->disk_name)-1])) {
  			if (buf < end)
  				*buf = 'p';
  			buf++;
  		}
  		buf = number(buf, end, bdev->bd_part->partno, spec);
  	}
  	return buf;
  }
  #endif

  static noinline_for_stack
  char *symbol_string(char *buf, char *end, void *ptr,

  		    struct printf_spec spec, const char *fmt)

  {

  	unsigned long value;

  #ifdef CONFIG_KALLSYMS
  	char sym[KSYM_SYMBOL_LEN];

  #endif
  
  	if (fmt[1] == 'R')
  		ptr = __builtin_extract_return_addr(ptr);
  	value = (unsigned long)ptr;
  
  #ifdef CONFIG_KALLSYMS
  	if (*fmt == 'B')

  		sprint_backtrace(sym, value);

  	else if (*fmt != 'f' && *fmt != 's')

  		sprint_symbol(sym, value);
  	else

  		sprint_symbol_no_offset(sym, value);

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

  #else

  	return special_hex_number(buf, end, value, sizeof(void *));

  #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;

  	}

  	if (decode && res->flags & IORESOURCE_UNSET) {
  		p = string(p, pend, "size ", str_spec);
  		p = number(p, pend, resource_size(res), *specp);
  	} else {
  		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 width 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; ++i) {
  		if (buf < end)
  			*buf = hex_asc_hi(addr[i]);
  		++buf;
  		if (buf < end)
  			*buf = hex_asc_lo(addr[i]);
  		++buf;

  		if (separator && i != len - 1) {
  			if (buf < end)
  				*buf = separator;
  			++buf;
  		}

  	}
  
  	return buf;
  }
  
  static noinline_for_stack

  char *bitmap_string(char *buf, char *end, unsigned long *bitmap,
  		    struct printf_spec spec, const char *fmt)
  {
  	const int CHUNKSZ = 32;
  	int nr_bits = max_t(int, spec.field_width, 0);
  	int i, chunksz;
  	bool first = true;
  
  	/* reused to print numbers */
  	spec = (struct printf_spec){ .flags = SMALL | ZEROPAD, .base = 16 };
  
  	chunksz = nr_bits & (CHUNKSZ - 1);
  	if (chunksz == 0)
  		chunksz = CHUNKSZ;
  
  	i = ALIGN(nr_bits, CHUNKSZ) - CHUNKSZ;
  	for (; i >= 0; i -= CHUNKSZ) {
  		u32 chunkmask, val;
  		int word, bit;
  
  		chunkmask = ((1ULL << chunksz) - 1);
  		word = i / BITS_PER_LONG;
  		bit = i % BITS_PER_LONG;
  		val = (bitmap[word] >> bit) & chunkmask;
  
  		if (!first) {
  			if (buf < end)
  				*buf = ',';
  			buf++;
  		}
  		first = false;
  
  		spec.field_width = DIV_ROUND_UP(chunksz, 4);
  		buf = number(buf, end, val, spec);
  
  		chunksz = CHUNKSZ;
  	}
  	return buf;
  }
  
  static noinline_for_stack
  char *bitmap_list_string(char *buf, char *end, unsigned long *bitmap,
  			 struct printf_spec spec, const char *fmt)
  {
  	int nr_bits = max_t(int, spec.field_width, 0);
  	/* current bit is 'cur', most recently seen range is [rbot, rtop] */
  	int cur, rbot, rtop;
  	bool first = true;
  
  	/* reused to print numbers */
  	spec = (struct printf_spec){ .base = 10 };
  
  	rbot = cur = find_first_bit(bitmap, nr_bits);
  	while (cur < nr_bits) {
  		rtop = cur;
  		cur = find_next_bit(bitmap, nr_bits, cur + 1);
  		if (cur < nr_bits && cur <= rtop + 1)
  			continue;
  
  		if (!first) {
  			if (buf < end)
  				*buf = ',';
  			buf++;
  		}
  		first = false;
  
  		buf = number(buf, end, rbot, spec);
  		if (rbot < rtop) {
  			if (buf < end)
  				*buf = '-';
  			buf++;
  
  			buf = number(buf, end, rtop, spec);
  		}
  
  		rbot = cur;
  	}
  	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[4] __aligned(2);	/* 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 *ip6_addr_string_sa(char *buf, char *end, const struct sockaddr_in6 *sa,
  			 struct printf_spec spec, const char *fmt)
  {
  	bool have_p = false, have_s = false, have_f = false, have_c = false;
  	char ip6_addr[sizeof("[xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255]") +
  		      sizeof(":12345") + sizeof("/123456789") +
  		      sizeof("%1234567890")];
  	char *p = ip6_addr, *pend = ip6_addr + sizeof(ip6_addr);
  	const u8 *addr = (const u8 *) &sa->sin6_addr;
  	char fmt6[2] = { fmt[0], '6' };
  	u8 off = 0;
  
  	fmt++;
  	while (isalpha(*++fmt)) {
  		switch (*fmt) {
  		case 'p':
  			have_p = true;
  			break;
  		case 'f':
  			have_f = true;
  			break;
  		case 's':
  			have_s = true;
  			break;
  		case 'c':
  			have_c = true;
  			break;
  		}
  	}
  
  	if (have_p || have_s || have_f) {
  		*p = '[';
  		off = 1;
  	}
  
  	if (fmt6[0] == 'I' && have_c)
  		p = ip6_compressed_string(ip6_addr + off, addr);
  	else
  		p = ip6_string(ip6_addr + off, addr, fmt6);
  
  	if (have_p || have_s || have_f)
  		*p++ = ']';
  
  	if (have_p) {
  		*p++ = ':';
  		p = number(p, pend, ntohs(sa->sin6_port), spec);
  	}
  	if (have_f) {
  		*p++ = '/';
  		p = number(p, pend, ntohl(sa->sin6_flowinfo &
  					  IPV6_FLOWINFO_MASK), spec);
  	}
  	if (have_s) {
  		*p++ = '%';
  		p = number(p, pend, sa->sin6_scope_id, spec);
  	}
  	*p = '\0';
  
  	return string(buf, end, ip6_addr, spec);
  }
  
  static noinline_for_stack
  char *ip4_addr_string_sa(char *buf, char *end, const struct sockaddr_in *sa,
  			 struct printf_spec spec, const char *fmt)
  {
  	bool have_p = false;
  	char *p, ip4_addr[sizeof("255.255.255.255") + sizeof(":12345")];
  	char *pend = ip4_addr + sizeof(ip4_addr);
  	const u8 *addr = (const u8 *) &sa->sin_addr.s_addr;
  	char fmt4[3] = { fmt[0], '4', 0 };
  
  	fmt++;
  	while (isalpha(*++fmt)) {
  		switch (*fmt) {
  		case 'p':
  			have_p = true;
  			break;
  		case 'h':
  		case 'l':
  		case 'n':
  		case 'b':
  			fmt4[2] = *fmt;
  			break;
  		}
  	}
  
  	p = ip4_string(ip4_addr, addr, fmt4);
  	if (have_p) {
  		*p++ = ':';
  		p = number(p, pend, ntohs(sa->sin_port), spec);
  	}
  	*p = '\0';
  
  	return string(buf, end, ip4_addr, spec);
  }
  
  static noinline_for_stack

  char *escaped_string(char *buf, char *end, u8 *addr, struct printf_spec spec,
  		     const char *fmt)
  {
  	bool found = true;
  	int count = 1;
  	unsigned int flags = 0;
  	int len;
  
  	if (spec.field_width == 0)
  		return buf;				/* nothing to print */
  
  	if (ZERO_OR_NULL_PTR(addr))
  		return string(buf, end, NULL, spec);	/* NULL pointer */
  
  
  	do {
  		switch (fmt[count++]) {
  		case 'a':
  			flags |= ESCAPE_ANY;
  			break;
  		case 'c':
  			flags |= ESCAPE_SPECIAL;
  			break;
  		case 'h':
  			flags |= ESCAPE_HEX;
  			break;
  		case 'n':
  			flags |= ESCAPE_NULL;
  			break;
  		case 'o':
  			flags |= ESCAPE_OCTAL;
  			break;
  		case 'p':
  			flags |= ESCAPE_NP;
  			break;
  		case 's':
  			flags |= ESCAPE_SPACE;
  			break;
  		default:
  			found = false;
  			break;
  		}
  	} while (found);
  
  	if (!flags)
  		flags = ESCAPE_ANY_NP;
  
  	len = spec.field_width < 0 ? 1 : spec.field_width;

  	/*
  	 * string_escape_mem() writes as many characters as it can to
  	 * the given buffer, and returns the total size of the output
  	 * had the buffer been big enough.
  	 */
  	buf += string_escape_mem(addr, len, buf, buf < end ? end - buf : 0, flags, NULL);

  
  	return buf;
  }
  
  static noinline_for_stack

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

  {

  	char uuid[UUID_STRING_LEN + 1];

  	char *p = uuid;
  	int i;

  	const u8 *index = uuid_be_index;

  	bool uc = false;
  
  	switch (*(++fmt)) {
  	case 'L':
  		uc = true;		/* fall-through */
  	case 'l':

  		index = uuid_le_index;

  		break;
  	case 'B':
  		uc = true;
  		break;
  	}
  
  	for (i = 0; i < 16; i++) {

  		if (uc)
  			p = hex_byte_pack_upper(p, addr[index[i]]);
  		else
  			p = hex_byte_pack(p, addr[index[i]]);

  		switch (i) {
  		case 3:
  		case 5:
  		case 7:
  		case 9:
  			*p++ = '-';
  			break;
  		}
  	}
  
  	*p = 0;

  	return string(buf, end, uuid, spec);
  }

  static noinline_for_stack
  char *netdev_bits(char *buf, char *end, const void *addr, const char *fmt)

  {

  	unsigned long long num;
  	int size;
  
  	switch (fmt[1]) {
  	case 'F':
  		num = *(const netdev_features_t *)addr;
  		size = sizeof(netdev_features_t);
  		break;
  	default:
  		num = (unsigned long)addr;
  		size = sizeof(unsigned long);
  		break;
  	}

  	return special_hex_number(buf, end, num, size);

  }

  static noinline_for_stack

  char *address_val(char *buf, char *end, const void *addr, const char *fmt)

  {
  	unsigned long long num;

  	int size;

  
  	switch (fmt[1]) {
  	case 'd':
  		num = *(const dma_addr_t *)addr;

  		size = sizeof(dma_addr_t);

  		break;
  	case 'p':
  	default:
  		num = *(const phys_addr_t *)addr;

  		size = sizeof(phys_addr_t);

  		break;
  	}

  	return special_hex_number(buf, end, num, size);

  }

  static noinline_for_stack
  char *clock(char *buf, char *end, struct clk *clk, struct printf_spec spec,
  	    const char *fmt)
  {
  	if (!IS_ENABLED(CONFIG_HAVE_CLK) || !clk)
  		return string(buf, end, NULL, spec);
  
  	switch (fmt[1]) {
  	case 'r':
  		return number(buf, end, clk_get_rate(clk), spec);
  
  	case 'n':
  	default:
  #ifdef CONFIG_COMMON_CLK
  		return string(buf, end, __clk_get_name(clk), spec);
  #else

  		return special_hex_number(buf, end, (unsigned long)clk, sizeof(unsigned long));

  #endif
  	}
  }

  static
  char *format_flags(char *buf, char *end, unsigned long flags,
  					const struct trace_print_flags *names)
  {
  	unsigned long mask;
  	const struct printf_spec strspec = {
  		.field_width = -1,
  		.precision = -1,
  	};
  	const struct printf_spec numspec = {
  		.flags = SPECIAL|SMALL,
  		.field_width = -1,
  		.precision = -1,
  		.base = 16,
  	};
  
  	for ( ; flags && names->name; names++) {
  		mask = names->mask;
  		if ((flags & mask) != mask)
  			continue;
  
  		buf = string(buf, end, names->name, strspec);
  
  		flags &= ~mask;
  		if (flags) {
  			if (buf < end)
  				*buf = '|';
  			buf++;
  		}
  	}
  
  	if (flags)
  		buf = number(buf, end, flags, numspec);
  
  	return buf;
  }
  
  static noinline_for_stack
  char *flags_string(char *buf, char *end, void *flags_ptr, const char *fmt)
  {
  	unsigned long flags;
  	const struct trace_print_flags *names;
  
  	switch (fmt[1]) {
  	case 'p':
  		flags = *(unsigned long *)flags_ptr;
  		/* Remove zone id */
  		flags &= (1UL << NR_PAGEFLAGS) - 1;
  		names = pageflag_names;
  		break;
  	case 'v':
  		flags = *(unsigned long *)flags_ptr;
  		names = vmaflag_names;
  		break;
  	case 'g':
  		flags = *(gfp_t *)flags_ptr;
  		names = gfpflag_names;
  		break;
  	default:
  		WARN_ONCE(1, "Unsupported flags modifier: %c
  ", fmt[1]);
  		return buf;
  	}
  
  	return format_flags(buf, end, flags, names);
  }

  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

   * - '[FfSs]R' as above with __builtin_extract_return_addr() translation

   * - '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]

   * - 'b[l]' For a bitmap, the number of bits is determined by the field
   *       width which must be explicitly specified either as part of the
   *       format string '%32b[l]' or through '%*b[l]', [l] selects
   *       range-list format instead of hex format

   * - '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

   *       [S][pfs]
   *       Generic IPv4/IPv6 address (struct sockaddr *) that falls back to
   *       [4] or [6] and is able to print port [p], flowinfo [f], scope [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)

   *       [S][pfs]
   *       Generic IPv4/IPv6 address (struct sockaddr *) that falls back to
   *       [4] or [6] and is able to print port [p], flowinfo [f], scope [s]
   * - '[Ii][4S][hnbl]' IPv4 addresses in host, network, big or little endian order
   * - 'I[6S]c' for IPv6 addresses printed as specified by

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

   * - 'E[achnops]' For an escaped buffer, where rules are defined by combination
   *                of the following flags (see string_escape_mem() for the
   *                details):
   *                  a - ESCAPE_ANY
   *                  c - ESCAPE_SPECIAL
   *                  h - ESCAPE_HEX
   *                  n - ESCAPE_NULL
   *                  o - ESCAPE_OCTAL
   *                  p - ESCAPE_NP
   *                  s - ESCAPE_SPACE
   *                By default ESCAPE_ANY_NP is used.

   * - '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.

   * - 'a[pd]' For address types [p] phys_addr_t, [d] dma_addr_t and derivatives
   *           (default assumed to be phys_addr_t, passed by reference)

   * - 'd[234]' For a dentry name (optionally 2-4 last components)
   * - 'D[234]' Same as 'd' but for a struct file

   * - 'g' For block_device name (gendisk + partition number)

   * - 'C' For a clock, it prints the name (Common Clock Framework) or address
   *       (legacy clock framework) of the clock
   * - 'Cn' For a clock, it prints the name (Common Clock Framework) or address
   *        (legacy clock framework) of the clock
   * - 'Cr' For a clock, it prints the current rate of the clock

   * - 'G' For flags to be printed as a collection of symbolic strings that would
   *       construct the specific value. Supported flags given by option:
   *       p page flags (see struct page) given as pointer to unsigned long
   *       g gfp flags (GFP_* and __GFP_*) given as pointer to gfp_t
   *       v vma flags (VM_*) given as pointer to unsigned long

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

   *

   * 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)

  {

  	const int default_width = 2 * sizeof(void *);

  	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 'b':
  		switch (fmt[1]) {
  		case 'l':
  			return bitmap_list_string(buf, end, ptr, spec, fmt);
  		default:
  			return bitmap_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);

  		case 'S': {
  			const union {
  				struct sockaddr		raw;
  				struct sockaddr_in	v4;
  				struct sockaddr_in6	v6;
  			} *sa = ptr;
  
  			switch (sa->raw.sa_family) {
  			case AF_INET:
  				return ip4_addr_string_sa(buf, end, &sa->v4, spec, fmt);
  			case AF_INET6:
  				return ip6_addr_string_sa(buf, end, &sa->v6, spec, fmt);
  			default:
  				return string(buf, end, "(invalid address)", spec);
  			}}

  		}

  		break;

  	case 'E':
  		return escaped_string(buf, end, ptr, spec, fmt);

  	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':

  		switch (kptr_restrict) {
  		case 0:
  			/* Always print %pK values */
  			break;
  		case 1: {

  			const struct cred *cred;
  
  			/*
  			 * kptr_restrict==1 cannot be used in IRQ context
  			 * because its test for CAP_SYSLOG would be meaningless.
  			 */
  			if (in_irq() || in_serving_softirq() || in_nmi()) {
  				if (spec.field_width == -1)
  					spec.field_width = default_width;
  				return string(buf, end, "pK-error", spec);
  			}

  			/*
  			 * Only print the real pointer value if the current
  			 * process has CAP_SYSLOG and is running with the
  			 * same credentials it started with. This is because
  			 * access to files is checked at open() time, but %pK
  			 * checks permission at read() time. We don't want to
  			 * leak pointer values if a binary opens a file using
  			 * %pK and then elevates privileges before reading it.
  			 */

  			cred = current_cred();

  			if (!has_capability_noaudit(current, CAP_SYSLOG) ||
  			    !uid_eq(cred->euid, cred->uid) ||
  			    !gid_eq(cred->egid, cred->gid))
  				ptr = NULL;
  			break;
  		}
  		case 2:
  		default:
  			/* Always print 0's for %pK */

  			ptr = NULL;

  			break;
  		}

  		break;

  	case 'N':

  		return netdev_bits(buf, end, ptr, fmt);

  	case 'a':

  		return address_val(buf, end, ptr, fmt);

  	case 'd':
  		return dentry_name(buf, end, ptr, spec, fmt);

  	case 'C':
  		return clock(buf, end, ptr, spec, fmt);

  	case 'D':
  		return dentry_name(buf, end,
  				   ((const struct file *)ptr)->f_path.dentry,
  				   spec, fmt);

  #ifdef CONFIG_BLOCK
  	case 'g':
  		return bdev_name(buf, end, ptr, spec, fmt);
  #endif

  	case 'G':
  		return flags_string(buf, end, ptr, fmt);

  	}
  	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;

  	char qualifier;

  
  	/* 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 */

  	qualifier = 0;

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

  		qualifier = *fmt++;
  		if (unlikely(qualifier == *fmt)) {
  			if (qualifier == 'l') {
  				qualifier = 'L';

  				++fmt;

  			} else if (qualifier == 'h') {
  				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;

  	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;

  	case 'n':
  		/*

  		 * Since %n poses a greater security risk than
  		 * utility, treat it as any other invalid or
  		 * unsupported format specifier.

  		 */

  		/* Fall-through */

  	default:

  		WARN_ONCE(1, "Please remove unsupported %%%c in format string
  ", *fmt);

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

  	}

  	if (qualifier == 'L')

  		spec->type = FORMAT_TYPE_LONG_LONG;

  	else if (qualifier == 'l') {

  		BUILD_BUG_ON(FORMAT_TYPE_ULONG + SIGN != FORMAT_TYPE_LONG);
  		spec->type = FORMAT_TYPE_ULONG + (spec->flags & SIGN);

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

  		spec->type = FORMAT_TYPE_SIZE_T;

  	} else if (qualifier == 't') {

  		spec->type = FORMAT_TYPE_PTRDIFF;

  	} else if (qualifier == 'H') {

  		BUILD_BUG_ON(FORMAT_TYPE_UBYTE + SIGN != FORMAT_TYPE_BYTE);
  		spec->type = FORMAT_TYPE_UBYTE + (spec->flags & SIGN);

  	} else if (qualifier == 'h') {

  		BUILD_BUG_ON(FORMAT_TYPE_USHORT + SIGN != FORMAT_TYPE_SHORT);
  		spec->type = FORMAT_TYPE_USHORT + (spec->flags & SIGN);

  	} else {

  		BUILD_BUG_ON(FORMAT_TYPE_UINT + SIGN != FORMAT_TYPE_INT);
  		spec->type = FORMAT_TYPE_UINT + (spec->flags & SIGN);

  	}

  
  	return ++fmt - start;

  }

  static void
  set_field_width(struct printf_spec *spec, int width)
  {
  	spec->field_width = width;
  	if (WARN_ONCE(spec->field_width != width, "field width %d too large", width)) {
  		spec->field_width = clamp(width, -FIELD_WIDTH_MAX, FIELD_WIDTH_MAX);
  	}
  }
  
  static void
  set_precision(struct printf_spec *spec, int prec)
  {
  	spec->precision = prec;
  	if (WARN_ONCE(spec->precision != prec, "precision %d too large", prec)) {
  		spec->precision = clamp(prec, 0, PRECISION_MAX);
  	}
  }

  /**
   * 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 generally follows C99 vsnprintf, but has some
   * extensions and a few limitations:
   *
   * %n is unsupported

   * %p* is handled by pointer()
   *
   * See pointer() or Documentation/printk-formats.txt for more
   * extensive description.

   *

   * ** Please update the documentation in both places 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(size > INT_MAX))

  		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:

  			set_field_width(&spec, va_arg(args, int));

  			break;

  		case FORMAT_TYPE_PRECISION:

  			set_precision(&spec, 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, 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:

  			/*
  			 * Presumably the arguments passed gcc's type
  			 * checking, but there is no safe or sane way
  			 * for us to continue parsing the format and
  			 * fetching from the va_list; the remaining
  			 * specifiers and arguments would be out of
  			 * sync.
  			 */
  			goto out;

  		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:

  				if (spec.flags & SIGN)
  					num = va_arg(args, ssize_t);
  				else
  					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);

  		}

  	}