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32 results

intel_engine_cs.c

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  • vsprintf.c 63.44 KiB
    /*
     *  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-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 <net/addrconf.h>
    
    #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     * This function is obsolete.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     * This function is obsolete.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 and one of
     * them then discarded. 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 += 2;
    	if (buf[-1] == '0')
    		buf--;
    	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 {
    	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)
    {
    	/* 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;
    
    	/* 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++] = 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 > 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);
    		BUILD_BUG_ON(' ' + 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 void widen(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);
    }
    
    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();
    	if (n < spec.field_width) {
    		/* we want to pad the sucker */
    		unsigned spaces = spec.field_width - n;
    		if (!(spec.flags & LEFT)) {
    			widen(buf - n, end, n, spaces);
    			return buf + spaces;
    		}
    		while (spaces--) {
    			if (buf < end)
    				*buf = ' ';
    			++buf;
    		}
    	}
    	return buf;
    }
    
    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
    	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;
    	}
    	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[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);
    }
    
    static noinline_for_stack
    char *address_val(char *buf, char *end, const void *addr,
    		  struct printf_spec spec, const char *fmt)
    {
    	unsigned long long num;
    
    	spec.flags |= SPECIAL | SMALL | ZEROPAD;
    	spec.base = 16;
    
    	switch (fmt[1]) {
    	case 'd':
    		num = *(const dma_addr_t *)addr;
    		spec.field_width = sizeof(dma_addr_t) * 2 + 2;
    		break;
    	case 'p':
    	default:
    		num = *(const phys_addr_t *)addr;
    		spec.field_width = sizeof(phys_addr_t) * 2 + 2;
    		break;
    	}
    
    	return number(buf, end, num, spec);
    }
    
    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
    		spec.base = 16;
    		spec.field_width = sizeof(unsigned long) * 2 + 2;
    		spec.flags |= SPECIAL | SMALL | ZEROPAD;
    		return number(buf, end, (unsigned long)clk, spec);
    #endif
    	}
    }
    
    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
     * - '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
     *
     * 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 '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':
    		/*
    		 * %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);
    		}
    
    		switch (kptr_restrict) {
    		case 0:
    			/* Always print %pK values */
    			break;
    		case 1: {
    			/*
    			 * 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.
    			 */
    			const struct cred *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':
    		switch (fmt[1]) {
    		case 'F':
    			return netdev_feature_string(buf, end, ptr, spec);
    		}
    		break;
    	case 'a':
    		return address_val(buf, end, ptr, spec, 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);
    	}
    	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;
    
    	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 an invalid format specifier. Warn about its use so
    		 * that new instances don't get added.
    		 */
    		WARN_ONCE(1, "Please remove ignored %%n in '%s'\n", fmt);
    		/* Fall-through */
    
    	default:
    		spec->type = FORMAT_TYPE_INVALID;
    		return fmt - start;
    	}
    
    	if (spec->qualifier == 'L')
    		spec->type = FORMAT_TYPE_LONG_LONG;
    	else if (spec->qualifier == 'l') {
    		BUILD_BUG_ON(FORMAT_TYPE_ULONG + SIGN != FORMAT_TYPE_LONG);
    		spec->type = FORMAT_TYPE_ULONG + (spec->flags & SIGN);
    	} 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') {
    		BUILD_BUG_ON(FORMAT_TYPE_UBYTE + SIGN != FORMAT_TYPE_BYTE);
    		spec->type = FORMAT_TYPE_UBYTE + (spec->flags & SIGN);
    	} else if (spec->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;
    }
    
    /**
     * 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
     * %pb output the bitmap with field width as the number of bits
     * %pbl output the bitmap as range list with field width as the number of bits
     * %pM output a 6-byte MAC address with colons
     * %pMR output a 6-byte MAC address with colons in reversed order
     * %pMF output a 6-byte MAC address with dashes
     * %pm output a 6-byte MAC address without colons
     * %pmR output a 6-byte MAC address without colons in reversed order
     * %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
     * %pIS depending on sa_family of 'struct sockaddr *' print IPv4/IPv6 address
     * %piS depending on sa_family of 'struct sockaddr *' print IPv4/IPv6 address
     * %pU[bBlL] print a UUID/GUID in big or little endian using lower or upper
     *   case.
     * %*pE[achnops] print an escaped buffer
     * %*ph[CDN] a variable-length hex string with a separator (supports up to 64
     *           bytes of the input)
     * %pC output the name (Common Clock Framework) or address (legacy clock
     *     framework) of a clock
     * %pCn output the name (Common Clock Framework) or address (legacy clock
     *      framework) of a clock
     * %pCr output the current rate of a clock
     * %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(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:
    			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, 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;
    
    		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);
    		}
    	}
    
    	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 skipped.
     *
     * 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;
    
    		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;
    			str = string(str, end, (char *)str_arg, spec);
    			break;
    		}
    
    		case FORMAT_TYPE_PTR:
    			str = pointer(fmt, str, end, get_arg(void *), spec);
    			while (isalnum(*fmt))
    				fmt++;
    			break;
    
    		case FORMAT_TYPE_PERCENT_CHAR:
    		case FORMAT_TYPE_INVALID:
    			if (str < end)
    				*str = '%';
    			++str;
    			break;
    
    		default: {
    			unsigned long long num;
    
    			switch (spec.type) {
    
    			case FORMAT_TYPE_LONG_LONG:
    				num = get_arg(long long);
    				break;
    			case FORMAT_TYPE_ULONG:
    			case FORMAT_TYPE_LONG:
    				num = get_arg(unsigned long);
    				break;
    			case FORMAT_TYPE_SIZE_T:
    				num = get_arg(size_t);
    				break;
    			case FORMAT_TYPE_PTRDIFF:
    				num = get_arg(ptrdiff_t);
    				break;
    			case FORMAT_TYPE_UBYTE:
    				num = get_arg(unsigned char);
    				break;
    			case FORMAT_TYPE_BYTE:
    				num = get_arg(signed char);
    				break;
    			case FORMAT_TYPE_USHORT:
    				num = get_arg(unsigned short);
    				break;
    			case FORMAT_TYPE_SHORT:
    				num = get_arg(short);
    				break;
    			case FORMAT_TYPE_UINT:
    				num = get_arg(unsigned int);
    				break;
    			default:
    				num = get_arg(int);
    			}
    
    			str = number(str, end, num, spec);
    		} /* default: */
    		} /* switch(spec.type) */
    	} /* while(*fmt) */
    
    	if (size > 0) {
    		if (str < end)
    			*str = '\0';
    		else
    			end[-1] = '\0';
    	}
    
    #undef get_arg
    
    	/* the trailing null byte doesn't count towards the total */
    	return str - buf;
    }
    EXPORT_SYMBOL_GPL(bstr_printf);
    
    /**
     * bprintf - 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
     * @...: Arguments for the format string
     *
     * The function returns the number of words(u32) written
     * into @bin_buf.
     */
    int bprintf(u32 *bin_buf, size_t size, const char *fmt, ...)
    {
    	va_list args;
    	int ret;
    
    	va_start(args, fmt);
    	ret = vbin_printf(bin_buf, size, fmt, args);
    	va_end(args);
    
    	return ret;
    }
    EXPORT_SYMBOL_GPL(bprintf);
    
    #endif /* CONFIG_BINARY_PRINTF */
    
    /**
     * vsscanf - Unformat a buffer into a list of arguments
     * @buf:	input buffer
     * @fmt:	format of buffer
     * @args:	arguments
     */
    int vsscanf(const char *buf, const char *fmt, va_list args)
    {
    	const char *str = buf;
    	char *next;
    	char digit;
    	int num = 0;
    	u8 qualifier;
    	unsigned int base;
    	union {
    		long long s;
    		unsigned long long u;
    	} val;
    	s16 field_width;
    	bool is_sign;
    
    	while (*fmt) {
    		/* skip any white space in format */
    		/* white space in format matchs any amount of
    		 * white space, including none, in the input.
    		 */
    		if (isspace(*fmt)) {
    			fmt = skip_spaces(++fmt);
    			str = skip_spaces(str);
    		}
    
    		/* anything that is not a conversion must match exactly */
    		if (*fmt != '%' && *fmt) {
    			if (*fmt++ != *str++)
    				break;
    			continue;
    		}
    
    		if (!*fmt)
    			break;
    		++fmt;
    
    		/* skip this conversion.
    		 * advance both strings to next white space
    		 */
    		if (*fmt == '*') {
    			if (!*str)
    				break;
    			while (!isspace(*fmt) && *fmt != '%' && *fmt)
    				fmt++;
    			while (!isspace(*str) && *str)
    				str++;
    			continue;
    		}
    
    		/* get field width */
    		field_width = -1;
    		if (isdigit(*fmt)) {
    			field_width = skip_atoi(&fmt);
    			if (field_width <= 0)
    				break;
    		}
    
    		/* get conversion qualifier */
    		qualifier = -1;
    		if (*fmt == 'h' || _tolower(*fmt) == 'l' ||
    		    _tolower(*fmt) == 'z') {
    			qualifier = *fmt++;
    			if (unlikely(qualifier == *fmt)) {
    				if (qualifier == 'h') {
    					qualifier = 'H';
    					fmt++;
    				} else if (qualifier == 'l') {
    					qualifier = 'L';
    					fmt++;
    				}
    			}
    		}
    
    		if (!*fmt)
    			break;
    
    		if (*fmt == 'n') {
    			/* return number of characters read so far */
    			*va_arg(args, int *) = str - buf;
    			++fmt;
    			continue;
    		}
    
    		if (!*str)
    			break;
    
    		base = 10;
    		is_sign = false;
    
    		switch (*fmt++) {
    		case 'c':
    		{
    			char *s = (char *)va_arg(args, char*);
    			if (field_width == -1)
    				field_width = 1;
    			do {
    				*s++ = *str++;
    			} while (--field_width > 0 && *str);
    			num++;
    		}
    		continue;
    		case 's':
    		{
    			char *s = (char *)va_arg(args, char *);
    			if (field_width == -1)
    				field_width = SHRT_MAX;
    			/* first, skip leading white space in buffer */
    			str = skip_spaces(str);
    
    			/* now copy until next white space */
    			while (*str && !isspace(*str) && field_width--)
    				*s++ = *str++;
    			*s = '\0';
    			num++;
    		}
    		continue;
    		case 'o':
    			base = 8;
    			break;
    		case 'x':
    		case 'X':
    			base = 16;
    			break;
    		case 'i':
    			base = 0;
    		case 'd':
    			is_sign = true;
    		case 'u':
    			break;
    		case '%':
    			/* looking for '%' in str */
    			if (*str++ != '%')
    				return num;
    			continue;
    		default:
    			/* invalid format; stop here */
    			return num;
    		}
    
    		/* have some sort of integer conversion.
    		 * first, skip white space in buffer.
    		 */
    		str = skip_spaces(str);
    
    		digit = *str;
    		if (is_sign && digit == '-')
    			digit = *(str + 1);
    
    		if (!digit
    		    || (base == 16 && !isxdigit(digit))
    		    || (base == 10 && !isdigit(digit))
    		    || (base == 8 && (!isdigit(digit) || digit > '7'))
    		    || (base == 0 && !isdigit(digit)))
    			break;
    
    		if (is_sign)
    			val.s = qualifier != 'L' ?
    				simple_strtol(str, &next, base) :
    				simple_strtoll(str, &next, base);
    		else
    			val.u = qualifier != 'L' ?
    				simple_strtoul(str, &next, base) :
    				simple_strtoull(str, &next, base);
    
    		if (field_width > 0 && next - str > field_width) {
    			if (base == 0)
    				_parse_integer_fixup_radix(str, &base);
    			while (next - str > field_width) {
    				if (is_sign)
    					val.s = div_s64(val.s, base);
    				else
    					val.u = div_u64(val.u, base);
    				--next;
    			}
    		}
    
    		switch (qualifier) {
    		case 'H':	/* that's 'hh' in format */
    			if (is_sign)
    				*va_arg(args, signed char *) = val.s;
    			else
    				*va_arg(args, unsigned char *) = val.u;
    			break;
    		case 'h':
    			if (is_sign)
    				*va_arg(args, short *) = val.s;
    			else
    				*va_arg(args, unsigned short *) = val.u;
    			break;
    		case 'l':
    			if (is_sign)
    				*va_arg(args, long *) = val.s;
    			else
    				*va_arg(args, unsigned long *) = val.u;
    			break;
    		case 'L':
    			if (is_sign)
    				*va_arg(args, long long *) = val.s;
    			else
    				*va_arg(args, unsigned long long *) = val.u;
    			break;
    		case 'Z':
    		case 'z':
    			*va_arg(args, size_t *) = val.u;
    			break;
    		default:
    			if (is_sign)
    				*va_arg(args, int *) = val.s;
    			else
    				*va_arg(args, unsigned int *) = val.u;
    			break;
    		}
    		num++;
    
    		if (!next)
    			break;
    		str = next;
    	}
    
    	return num;
    }
    EXPORT_SYMBOL(vsscanf);
    
    /**
     * sscanf - Unformat a buffer into a list of arguments
     * @buf:	input buffer
     * @fmt:	formatting of buffer
     * @...:	resulting arguments
     */
    int sscanf(const char *buf, const char *fmt, ...)
    {
    	va_list args;
    	int i;
    
    	va_start(args, fmt);
    	i = vsscanf(buf, fmt, args);
    	va_end(args);
    
    	return i;
    }
    EXPORT_SYMBOL(sscanf);