vsprintf.c 70.6 KB
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/*
 *  linux/lib/vsprintf.c
 *
 *  Copyright (C) 1991, 1992  Linus Torvalds
 */

/* vsprintf.c -- Lars Wirzenius & Linus Torvalds. */
/*
 * Wirzenius wrote this portably, Torvalds fucked it up :-)
 */

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/*
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 * 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>
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#include <linux/clk.h>
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#include <linux/clk-provider.h>
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#include <linux/module.h>	/* for KSYM_SYMBOL_LEN */
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#include <linux/types.h>
#include <linux/string.h>
#include <linux/ctype.h>
#include <linux/kernel.h>
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#include <linux/kallsyms.h>
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#include <linux/math64.h>
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#include <linux/uaccess.h>
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#include <linux/ioport.h>
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#include <linux/dcache.h>
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#include <linux/cred.h>
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#include <linux/uuid.h>
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#include <linux/of.h>
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#include <net/addrconf.h>
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#ifdef CONFIG_BLOCK
#include <linux/blkdev.h>
#endif
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#include "../mm/internal.h"	/* For the trace_print_flags arrays */

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#include <asm/page.h>		/* for PAGE_SIZE */
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#include <asm/sections.h>	/* for dereference_function_descriptor() */
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#include <asm/byteorder.h>	/* cpu_to_le16 */
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#include <linux/string_helpers.h>
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#include "kstrtox.h"
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/**
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 * simple_strtoull - convert a string to an unsigned long long
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 * @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
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 *
 * This function is obsolete. Please use kstrtoull instead.
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 */
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unsigned long long simple_strtoull(const char *cp, char **endp, unsigned int base)
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{
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	unsigned long long result;
	unsigned int rv;
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	cp = _parse_integer_fixup_radix(cp, &base);
	rv = _parse_integer(cp, base, &result);
	/* FIXME */
	cp += (rv & ~KSTRTOX_OVERFLOW);
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	if (endp)
		*endp = (char *)cp;
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	return result;
}
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EXPORT_SYMBOL(simple_strtoull);
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/**
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 * simple_strtoul - convert a string to an unsigned long
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 * @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
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 *
 * This function is obsolete. Please use kstrtoul instead.
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 */
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unsigned long simple_strtoul(const char *cp, char **endp, unsigned int base)
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{
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	return simple_strtoull(cp, endp, base);
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}
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EXPORT_SYMBOL(simple_strtoul);
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/**
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 * simple_strtol - convert a string to a signed long
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 * @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
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 *
 * This function is obsolete. Please use kstrtol instead.
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 */
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long simple_strtol(const char *cp, char **endp, unsigned int base)
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{
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	if (*cp == '-')
		return -simple_strtoul(cp + 1, endp, base);
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	return simple_strtoul(cp, endp, base);
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}
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EXPORT_SYMBOL(simple_strtol);
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/**
 * 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
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 *
 * This function is obsolete. Please use kstrtoll instead.
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 */
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long long simple_strtoll(const char *cp, char **endp, unsigned int base)
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{
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	if (*cp == '-')
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		return -simple_strtoull(cp + 1, endp, base);
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	return simple_strtoull(cp, endp, base);
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}
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EXPORT_SYMBOL(simple_strtoll);
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static noinline_for_stack
int skip_atoi(const char **s)
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{
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	int i = 0;
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	do {
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		i = i*10 + *((*s)++) - '0';
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	} while (isdigit(**s));
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	return i;
}

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/*
 * Decimal conversion is by far the most typical, and is used for
 * /proc and /sys data. This directly impacts e.g. top performance
 * with many processes running. We optimize it for speed 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.
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 */
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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
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 * 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.
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*/
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static noinline_for_stack
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char *put_dec_trunc8(char *buf, unsigned r)
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{
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	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];
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	buf += r < 10 ? 1 : 2;
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	return buf;
}
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#if BITS_PER_LONG == 64 && BITS_PER_LONG_LONG == 64
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static noinline_for_stack
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char *put_dec_full8(char *buf, unsigned r)
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{
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	unsigned q;

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	/* 0 <= r < 10^8 */
	q = (r * (u64)0x28f5c29) >> 32;
	*((u16 *)buf) = decpair[r - 100*q];
	buf += 2;
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	/* 0 <= q < 10^6 */
	r = (q * (u64)0x28f5c29) >> 32;
	*((u16 *)buf) = decpair[q - 100*r];
	buf += 2;
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	/* 0 <= r < 10^4 */
	q = (r * 0x147b) >> 19;
	*((u16 *)buf) = decpair[r - 100*q];
	buf += 2;
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	/* 0 <= q < 100 */
	*((u16 *)buf) = decpair[q];
	buf += 2;
	return buf;
}
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static noinline_for_stack
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char *put_dec(char *buf, unsigned long long n)
{
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	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 */
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	return put_dec_trunc8(buf, n);
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}
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#elif BITS_PER_LONG == 32 && BITS_PER_LONG_LONG == 64
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static void
put_dec_full4(char *buf, unsigned r)
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{
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	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];
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}

/*
 * 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.
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 * (second call in the put_dec code, assuming n is all-ones).
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 */
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static noinline_for_stack
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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;
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}

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/* 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" */

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	/* n = 2^48 d3 + 2^32 d2 + 2^16 d1 + d0
	     = 281_4749_7671_0656 d3 + 42_9496_7296 d2 + 6_5536 d1 + d0 */
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	q   = 656 * d3 + 7296 * d2 + 5536 * d1 + ((uint32_t)n & 0xffff);
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	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);
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	q += 281 * d3;
	buf += 12;
	if (q)
		buf = put_dec_trunc8(buf, q);
	else while (buf[-1] == '0')
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		--buf;

	return buf;
}

#endif

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

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

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#define SIGN	1		/* unsigned/signed, must be 1 */
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#define LEFT	2		/* left justified */
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#define PLUS	4		/* show plus */
#define SPACE	8		/* space if plus */
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#define ZEROPAD	16		/* pad with zero, must be 16 == '0' - ' ' */
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#define SMALL	32		/* use lowercase in hex (must be 32 == 0x20) */
#define SPECIAL	64		/* prefix hex with "0x", octal with "0" */
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enum format_type {
	FORMAT_TYPE_NONE, /* Just a string part */
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	FORMAT_TYPE_WIDTH,
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	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,
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	FORMAT_TYPE_UBYTE,
	FORMAT_TYPE_BYTE,
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	FORMAT_TYPE_USHORT,
	FORMAT_TYPE_SHORT,
	FORMAT_TYPE_UINT,
	FORMAT_TYPE_INT,
	FORMAT_TYPE_SIZE_T,
	FORMAT_TYPE_PTRDIFF
};

struct printf_spec {
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	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;
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#define FIELD_WIDTH_MAX ((1 << 23) - 1)
#define PRECISION_MAX ((1 << 15) - 1)
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static noinline_for_stack
char *number(char *buf, char *end, unsigned long long num,
	     struct printf_spec spec)
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{
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	/* put_dec requires 2-byte alignment of the buffer. */
	char tmp[3 * sizeof(num)] __aligned(2);
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	char sign;
	char locase;
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	int need_pfx = ((spec.flags & SPECIAL) && spec.base != 10);
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	int i;
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	bool is_zero = num == 0LL;
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	int field_width = spec.field_width;
	int precision = spec.precision;
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	BUILD_BUG_ON(sizeof(struct printf_spec) != 8);

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	/* locase = 0 or 0x20. ORing digits or letters with 'locase'
	 * produces same digits or (maybe lowercased) letters */
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	locase = (spec.flags & SMALL);
	if (spec.flags & LEFT)
		spec.flags &= ~ZEROPAD;
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	sign = 0;
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	if (spec.flags & SIGN) {
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		if ((signed long long)num < 0) {
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			sign = '-';
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			num = -(signed long long)num;
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			field_width--;
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		} else if (spec.flags & PLUS) {
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			sign = '+';
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			field_width--;
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		} else if (spec.flags & SPACE) {
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			sign = ' ';
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			field_width--;
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		}
	}
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	if (need_pfx) {
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		if (spec.base == 16)
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			field_width -= 2;
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		else if (!is_zero)
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			field_width--;
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	}
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	/* generate full string in tmp[], in reverse order */
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	i = 0;
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	if (num < spec.base)
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		tmp[i++] = hex_asc_upper[num] | locase;
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	else if (spec.base != 10) { /* 8 or 16 */
		int mask = spec.base - 1;
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		int shift = 3;
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		if (spec.base == 16)
			shift = 4;
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		do {
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			tmp[i++] = (hex_asc_upper[((unsigned char)num) & mask] | locase);
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			num >>= shift;
		} while (num);
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	} else { /* base 10 */
		i = put_dec(tmp, num) - tmp;
	}
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	/* printing 100 using %2d gives "100", not "00" */
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	if (i > precision)
		precision = i;
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	/* leading space padding */
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	field_width -= precision;
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	if (!(spec.flags & (ZEROPAD | LEFT))) {
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		while (--field_width >= 0) {
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			if (buf < end)
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				*buf = ' ';
			++buf;
		}
	}
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	/* sign */
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	if (sign) {
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		if (buf < end)
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			*buf = sign;
		++buf;
	}
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	/* "0x" / "0" prefix */
	if (need_pfx) {
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		if (spec.base == 16 || !is_zero) {
			if (buf < end)
				*buf = '0';
			++buf;
		}
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		if (spec.base == 16) {
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			if (buf < end)
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				*buf = ('X' | locase);
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			++buf;
		}
	}
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	/* zero or space padding */
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	if (!(spec.flags & LEFT)) {
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		char c = ' ' + (spec.flags & ZEROPAD);
		BUILD_BUG_ON(' ' + ZEROPAD != '0');
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		while (--field_width >= 0) {
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			if (buf < end)
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				*buf = c;
			++buf;
		}
	}
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	/* hmm even more zero padding? */
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	while (i <= --precision) {
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		if (buf < end)
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			*buf = '0';
		++buf;
	}
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	/* actual digits of result */
	while (--i >= 0) {
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		if (buf < end)
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			*buf = tmp[i];
		++buf;
	}
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	/* trailing space padding */
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	while (--field_width >= 0) {
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		if (buf < end)
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			*buf = ' ';
		++buf;
	}
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	return buf;
}

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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);
}

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

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/*
 * 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;
}

583 584 585
static noinline_for_stack
char *string(char *buf, char *end, const char *s, struct printf_spec spec)
{
586 587
	int len = 0;
	size_t lim = spec.precision;
588 589 590 591

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

592 593 594 595
	while (lim--) {
		char c = *s++;
		if (!c)
			break;
596
		if (buf < end)
597
			*buf = c;
598
		++buf;
599
		++len;
600
	}
601
	return widen_string(buf, len, end, spec);
602 603
}

A
Al Viro 已提交
604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622
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) {
623 624
		p = READ_ONCE(d->d_parent);
		array[i] = READ_ONCE(d->d_name.name);
A
Al Viro 已提交
625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644
		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();
645
	return widen_string(buf, n, end, spec);
A
Al Viro 已提交
646 647
}

648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667
#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

J
Joe Perches 已提交
668 669
static noinline_for_stack
char *symbol_string(char *buf, char *end, void *ptr,
670
		    struct printf_spec spec, const char *fmt)
671
{
672
	unsigned long value;
673 674
#ifdef CONFIG_KALLSYMS
	char sym[KSYM_SYMBOL_LEN];
675 676 677 678 679 680 681 682
#endif

	if (fmt[1] == 'R')
		ptr = __builtin_extract_return_addr(ptr);
	value = (unsigned long)ptr;

#ifdef CONFIG_KALLSYMS
	if (*fmt == 'B')
683
		sprint_backtrace(sym, value);
684
	else if (*fmt != 'f' && *fmt != 's')
685 686
		sprint_symbol(sym, value);
	else
687
		sprint_symbol_no_offset(sym, value);
688

689
	return string(buf, end, sym, spec);
690
#else
691
	return special_hex_number(buf, end, value, sizeof(void *));
692 693 694
#endif
}

J
Joe Perches 已提交
695 696 697
static noinline_for_stack
char *resource_string(char *buf, char *end, struct resource *res,
		      struct printf_spec spec, const char *fmt)
698 699
{
#ifndef IO_RSRC_PRINTK_SIZE
700
#define IO_RSRC_PRINTK_SIZE	6
701 702 703
#endif

#ifndef MEM_RSRC_PRINTK_SIZE
704
#define MEM_RSRC_PRINTK_SIZE	10
705
#endif
706
	static const struct printf_spec io_spec = {
707
		.base = 16,
708
		.field_width = IO_RSRC_PRINTK_SIZE,
709 710 711
		.precision = -1,
		.flags = SPECIAL | SMALL | ZEROPAD,
	};
712 713 714 715 716 717
	static const struct printf_spec mem_spec = {
		.base = 16,
		.field_width = MEM_RSRC_PRINTK_SIZE,
		.precision = -1,
		.flags = SPECIAL | SMALL | ZEROPAD,
	};
B
Bjorn Helgaas 已提交
718 719 720 721 722 723
	static const struct printf_spec bus_spec = {
		.base = 16,
		.field_width = 2,
		.precision = -1,
		.flags = SMALL | ZEROPAD,
	};
724
	static const struct printf_spec dec_spec = {
725 726 727 728
		.base = 10,
		.precision = -1,
		.flags = 0,
	};
729
	static const struct printf_spec str_spec = {
730 731 732 733
		.field_width = -1,
		.precision = 10,
		.flags = LEFT,
	};
734
	static const struct printf_spec flag_spec = {
735 736 737 738
		.base = 16,
		.precision = -1,
		.flags = SPECIAL | SMALL,
	};
739 740 741 742 743

	/* 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))
B
Bjorn Helgaas 已提交
744
#define DECODED_BUF_SIZE	sizeof("[mem - 64bit pref window disabled]")
745 746 747 748
#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)];

749
	char *p = sym, *pend = sym + sizeof(sym);
750
	int decode = (fmt[0] == 'R') ? 1 : 0;
751
	const struct printf_spec *specp;
752 753

	*p++ = '[';
754
	if (res->flags & IORESOURCE_IO) {
755
		p = string(p, pend, "io  ", str_spec);
756 757
		specp = &io_spec;
	} else if (res->flags & IORESOURCE_MEM) {
758
		p = string(p, pend, "mem ", str_spec);
759 760
		specp = &mem_spec;
	} else if (res->flags & IORESOURCE_IRQ) {
761
		p = string(p, pend, "irq ", str_spec);
762 763
		specp = &dec_spec;
	} else if (res->flags & IORESOURCE_DMA) {
764
		p = string(p, pend, "dma ", str_spec);
765
		specp = &dec_spec;
B
Bjorn Helgaas 已提交
766 767 768
	} else if (res->flags & IORESOURCE_BUS) {
		p = string(p, pend, "bus ", str_spec);
		specp = &bus_spec;
769
	} else {
770
		p = string(p, pend, "??? ", str_spec);
771
		specp = &mem_spec;
772
		decode = 0;
773
	}
774 775 776 777 778 779 780 781 782
	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);
		}
783
	}
784
	if (decode) {
785 786 787 788
		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);
B
Bjorn Helgaas 已提交
789 790
		if (res->flags & IORESOURCE_WINDOW)
			p = string(p, pend, " window", str_spec);
791 792
		if (res->flags & IORESOURCE_DISABLED)
			p = string(p, pend, " disabled", str_spec);
793 794 795
	} else {
		p = string(p, pend, " flags ", str_spec);
		p = number(p, pend, res->flags, flag_spec);
796
	}
797
	*p++ = ']';
798
	*p = '\0';
799

800
	return string(buf, end, sym, spec);
801 802
}

803 804 805 806
static noinline_for_stack
char *hex_string(char *buf, char *end, u8 *addr, struct printf_spec spec,
		 const char *fmt)
{
807
	int i, len = 1;		/* if we pass '%ph[CDN]', field width remains
808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836
				   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);

837 838 839 840 841 842 843
	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;
844

845 846 847 848 849
		if (separator && i != len - 1) {
			if (buf < end)
				*buf = separator;
			++buf;
		}
850 851 852 853 854
	}

	return buf;
}

855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935
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;
}

J
Joe Perches 已提交
936 937 938
static noinline_for_stack
char *mac_address_string(char *buf, char *end, u8 *addr,
			 struct printf_spec spec, const char *fmt)
939
{
940
	char mac_addr[sizeof("xx:xx:xx:xx:xx:xx")];
941 942
	char *p = mac_addr;
	int i;
943
	char separator;
944
	bool reversed = false;
945

946 947
	switch (fmt[1]) {
	case 'F':
948
		separator = '-';
949 950 951 952 953 954 955
		break;

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

	default:
956
		separator = ':';
957
		break;
958
	}
959 960

	for (i = 0; i < 6; i++) {
961 962 963 964 965
		if (reversed)
			p = hex_byte_pack(p, addr[5 - i]);
		else
			p = hex_byte_pack(p, addr[i]);

966
		if (fmt[0] == 'M' && i != 5)
967
			*p++ = separator;
968 969 970
	}
	*p = '\0';

971
	return string(buf, end, mac_addr, spec);
972 973
}

J
Joe Perches 已提交
974 975
static noinline_for_stack
char *ip4_string(char *p, const u8 *addr, const char *fmt)
976 977
{
	int i;
978 979 980 981 982 983 984 985 986 987 988 989 990 991 992 993 994 995 996 997 998 999 1000 1001 1002
	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;
	}
1003
	for (i = 0; i < 4; i++) {
1004
		char temp[4] __aligned(2);	/* hold each IP quad in reverse order */
1005
		int digits = put_dec_trunc8(temp, addr[index]) - temp;
1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016
		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++ = '.';
1017
		index += step;
1018 1019
	}
	*p = '\0';
1020

1021 1022 1023
	return p;
}

J
Joe Perches 已提交
1024 1025
static noinline_for_stack
char *ip6_compressed_string(char *p, const char *addr)
1026
{
1027
	int i, j, range;
1028 1029 1030 1031
	unsigned char zerolength[8];
	int longest = 1;
	int colonpos = -1;
	u16 word;
1032
	u8 hi, lo;
1033
	bool needcolon = false;
1034 1035 1036 1037 1038 1039
	bool useIPv4;
	struct in6_addr in6;

	memcpy(&in6, addr, sizeof(struct in6_addr));

	useIPv4 = ipv6_addr_v4mapped(&in6) || ipv6_addr_is_isatap(&in6);
1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050

	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++) {
1051
			if (in6.s6_addr16[j] != 0)
1052 1053 1054 1055 1056 1057 1058 1059 1060 1061
				break;
			zerolength[i]++;
		}
	}
	for (i = 0; i < range; i++) {
		if (zerolength[i] > longest) {
			longest = zerolength[i];
			colonpos = i;
		}
	}
1062 1063
	if (longest == 1)		/* don't compress a single 0 */
		colonpos = -1;
1064

1065 1066 1067 1068 1069 1070 1071 1072 1073 1074 1075 1076 1077 1078 1079
	/* 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 */
1080
		word = ntohs(in6.s6_addr16[i]);
1081 1082 1083 1084
		hi = word >> 8;
		lo = word & 0xff;
		if (hi) {
			if (hi > 0x0f)
1085
				p = hex_byte_pack(p, hi);
1086 1087
			else
				*p++ = hex_asc_lo(hi);
1088
			p = hex_byte_pack(p, lo);
1089
		}
1090
		else if (lo > 0x0f)
1091
			p = hex_byte_pack(p, lo);
1092 1093 1094 1095 1096 1097 1098 1099
		else
			*p++ = hex_asc_lo(lo);
		needcolon = true;
	}

	if (useIPv4) {
		if (needcolon)
			*p++ = ':';
1100
		p = ip4_string(p, &in6.s6_addr[12], "I4");
1101 1102
	}
	*p = '\0';
1103

1104 1105 1106
	return p;
}

J
Joe Perches 已提交
1107 1108
static noinline_for_stack
char *ip6_string(char *p, const char *addr, const char *fmt)
1109 1110
{
	int i;
1111

1112
	for (i = 0; i < 8; i++) {
1113 1114
		p = hex_byte_pack(p, *addr++);
		p = hex_byte_pack(p, *addr++);
1115
		if (fmt[0] == 'I' && i != 7)
1116 1117 1118
			*p++ = ':';
	}
	*p = '\0';
1119

1120 1121 1122
	return p;
}

J
Joe Perches 已提交
1123 1124 1125
static noinline_for_stack
char *ip6_addr_string(char *buf, char *end, const u8 *addr,
		      struct printf_spec spec, const char *fmt)
1126 1127 1128 1129
{
	char ip6_addr[sizeof("xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255")];

	if (fmt[0] == 'I' && fmt[2] == 'c')
1130
		ip6_compressed_string(ip6_addr, addr);
1131
	else
1132
		ip6_string(ip6_addr, addr, fmt);
1133

1134
	return string(buf, end, ip6_addr, spec);
1135 1136
}

J
Joe Perches 已提交
1137 1138 1139
static noinline_for_stack
char *ip4_addr_string(char *buf, char *end, const u8 *addr,
		      struct printf_spec spec, const char *fmt)
1140
{
1141
	char ip4_addr[sizeof("255.255.255.255")];
1142

1143
	ip4_string(ip4_addr, addr, fmt);
1144

1145
	return string(buf, end, ip4_addr, spec);
1146 1147
}

1148 1149 1150 1151 1152 1153 1154 1155 1156 1157 1158 1159 1160 1161 1162 1163 1164 1165 1166 1167 1168 1169 1170 1171 1172 1173 1174 1175 1176 1177 1178 1179 1180 1181 1182 1183 1184 1185 1186 1187 1188 1189 1190 1191 1192 1193 1194 1195 1196 1197 1198 1199 1200 1201 1202 1203 1204 1205 1206 1207 1208 1209 1210 1211 1212 1213 1214 1215 1216 1217 1218 1219 1220 1221 1222 1223 1224 1225 1226 1227 1228 1229 1230 1231 1232 1233 1234 1235 1236 1237 1238 1239 1240 1241 1242 1243 1244
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);
}

1245 1246 1247 1248 1249 1250 1251 1252 1253 1254 1255 1256 1257 1258 1259 1260 1261 1262 1263 1264 1265 1266 1267 1268 1269 1270 1271 1272 1273 1274 1275 1276 1277 1278 1279 1280 1281 1282 1283 1284 1285 1286 1287 1288 1289 1290 1291 1292 1293 1294
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;

1295 1296 1297 1298 1299 1300
	/*
	 * 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);
1301 1302 1303 1304

	return buf;
}

J
Joe Perches 已提交
1305 1306 1307
static noinline_for_stack
char *uuid_string(char *buf, char *end, const u8 *addr,
		  struct printf_spec spec, const char *fmt)
1308
{
1309
	char uuid[UUID_STRING_LEN + 1];
1310 1311
	char *p = uuid;
	int i;
C
Christoph Hellwig 已提交
1312
	const u8 *index = uuid_index;
1313 1314 1315 1316 1317 1318
	bool uc = false;

	switch (*(++fmt)) {
	case 'L':
		uc = true;		/* fall-through */
	case 'l':
C
Christoph Hellwig 已提交
1319
		index = guid_index;
1320 1321 1322 1323 1324 1325 1326
		break;
	case 'B':
		uc = true;
		break;
	}

	for (i = 0; i < 16; i++) {
1327 1328 1329 1330
		if (uc)
			p = hex_byte_pack_upper(p, addr[index[i]]);
		else
			p = hex_byte_pack(p, addr[index[i]]);
1331 1332 1333 1334 1335 1336 1337 1338 1339 1340 1341 1342 1343 1344 1345
		switch (i) {
		case 3:
		case 5:
		case 7:
		case 9:
			*p++ = '-';
			break;
		}
	}

	*p = 0;

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

1346 1347 1348 1349 1350 1351 1352 1353 1354 1355 1356 1357 1358 1359 1360 1361 1362 1363 1364 1365 1366 1367 1368 1369 1370 1371 1372 1373 1374 1375 1376 1377 1378 1379 1380 1381 1382 1383 1384 1385 1386 1387 1388 1389 1390 1391 1392 1393 1394 1395 1396 1397 1398
int kptr_restrict __read_mostly;

static noinline_for_stack
char *restricted_pointer(char *buf, char *end, const void *ptr,
			 struct printf_spec spec)
{
	spec.base = 16;
	spec.flags |= SMALL;
	if (spec.field_width == -1) {
		spec.field_width = 2 * sizeof(ptr);
		spec.flags |= ZEROPAD;
	}

	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())
			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;
	}

	return number(buf, end, (unsigned long)ptr, spec);
}

1399 1400
static noinline_for_stack
char *netdev_bits(char *buf, char *end, const void *addr, const char *fmt)
1401
{
1402 1403 1404 1405 1406 1407 1408 1409 1410 1411 1412 1413 1414
	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;
	}
1415

1416
	return special_hex_number(buf, end, num, size);
1417 1418
}

1419
static noinline_for_stack
1420
char *address_val(char *buf, char *end, const void *addr, const char *fmt)
1421 1422
{
	unsigned long long num;
1423
	int size;
1424 1425 1426 1427

	switch (fmt[1]) {
	case 'd':
		num = *(const dma_addr_t *)addr;
1428
		size = sizeof(dma_addr_t);
1429 1430 1431 1432
		break;
	case 'p':
	default:
		num = *(const phys_addr_t *)addr;
1433
		size = sizeof(phys_addr_t);
1434 1435 1436
		break;
	}

1437
	return special_hex_number(buf, end, num, size);
1438 1439
}

1440 1441 1442 1443 1444 1445 1446 1447 1448 1449 1450 1451 1452 1453 1454 1455
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
1456
		return special_hex_number(buf, end, (unsigned long)clk, sizeof(unsigned long));
1457 1458 1459 1460
#endif
	}
}

1461 1462 1463 1464 1465 1466 1467 1468 1469 1470 1471 1472 1473 1474 1475 1476 1477 1478 1479 1480 1481 1482 1483 1484 1485 1486 1487 1488 1489 1490 1491 1492 1493 1494 1495 1496 1497 1498 1499 1500 1501 1502 1503 1504 1505 1506 1507 1508 1509 1510 1511 1512 1513 1514 1515 1516 1517 1518 1519 1520 1521 1522 1523 1524 1525 1526
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\n", fmt[1]);
		return buf;
	}

	return format_flags(buf, end, flags, names);
}

1527 1528 1529 1530 1531 1532 1533 1534 1535 1536 1537 1538 1539 1540 1541 1542 1543 1544 1545 1546 1547 1548 1549 1550 1551 1552 1553 1554 1555 1556 1557 1558 1559 1560 1561 1562 1563 1564 1565 1566 1567 1568 1569 1570 1571 1572 1573 1574 1575 1576 1577 1578 1579 1580 1581 1582 1583 1584 1585 1586 1587 1588 1589 1590 1591 1592 1593 1594 1595 1596 1597 1598 1599 1600 1601 1602 1603 1604 1605 1606 1607 1608 1609 1610 1611 1612 1613 1614 1615 1616 1617 1618 1619 1620 1621 1622 1623 1624 1625 1626 1627 1628 1629 1630 1631 1632 1633 1634 1635 1636 1637 1638 1639 1640 1641 1642 1643 1644 1645 1646
static const char *device_node_name_for_depth(const struct device_node *np, int depth)
{
	for ( ; np && depth; depth--)
		np = np->parent;

	return kbasename(np->full_name);
}

static noinline_for_stack
char *device_node_gen_full_name(const struct device_node *np, char *buf, char *end)
{
	int depth;
	const struct device_node *parent = np->parent;
	static const struct printf_spec strspec = {
		.field_width = -1,
		.precision = -1,
	};

	/* special case for root node */
	if (!parent)
		return string(buf, end, "/", strspec);

	for (depth = 0; parent->parent; depth++)
		parent = parent->parent;

	for ( ; depth >= 0; depth--) {
		buf = string(buf, end, "/", strspec);
		buf = string(buf, end, device_node_name_for_depth(np, depth),
			     strspec);
	}
	return buf;
}

static noinline_for_stack
char *device_node_string(char *buf, char *end, struct device_node *dn,
			 struct printf_spec spec, const char *fmt)
{
	char tbuf[sizeof("xxxx") + 1];
	const char *p;
	int ret;
	char *buf_start = buf;
	struct property *prop;
	bool has_mult, pass;
	static const struct printf_spec num_spec = {
		.flags = SMALL,
		.field_width = -1,
		.precision = -1,
		.base = 10,
	};

	struct printf_spec str_spec = spec;
	str_spec.field_width = -1;

	if (!IS_ENABLED(CONFIG_OF))
		return string(buf, end, "(!OF)", spec);

	if ((unsigned long)dn < PAGE_SIZE)
		return string(buf, end, "(null)", spec);

	/* simple case without anything any more format specifiers */
	fmt++;
	if (fmt[0] == '\0' || strcspn(fmt,"fnpPFcC") > 0)
		fmt = "f";

	for (pass = false; strspn(fmt,"fnpPFcC"); fmt++, pass = true) {
		if (pass) {
			if (buf < end)
				*buf = ':';
			buf++;
		}

		switch (*fmt) {
		case 'f':	/* full_name */
			buf = device_node_gen_full_name(dn, buf, end);
			break;
		case 'n':	/* name */
			buf = string(buf, end, dn->name, str_spec);
			break;
		case 'p':	/* phandle */
			buf = number(buf, end, (unsigned int)dn->phandle, num_spec);
			break;
		case 'P':	/* path-spec */
			p = kbasename(of_node_full_name(dn));
			if (!p[1])
				p = "/";
			buf = string(buf, end, p, str_spec);
			break;
		case 'F':	/* flags */
			tbuf[0] = of_node_check_flag(dn, OF_DYNAMIC) ? 'D' : '-';
			tbuf[1] = of_node_check_flag(dn, OF_DETACHED) ? 'd' : '-';
			tbuf[2] = of_node_check_flag(dn, OF_POPULATED) ? 'P' : '-';
			tbuf[3] = of_node_check_flag(dn, OF_POPULATED_BUS) ? 'B' : '-';
			tbuf[4] = 0;
			buf = string(buf, end, tbuf, str_spec);
			break;
		case 'c':	/* major compatible string */
			ret = of_property_read_string(dn, "compatible", &p);
			if (!ret)
				buf = string(buf, end, p, str_spec);
			break;
		case 'C':	/* full compatible string */
			has_mult = false;
			of_property_for_each_string(dn, "compatible", prop, p) {
				if (has_mult)
					buf = string(buf, end, ",", str_spec);
				buf = string(buf, end, "\"", str_spec);
				buf = string(buf, end, p, str_spec);
				buf = string(buf, end, "\"", str_spec);

				has_mult = true;
			}
			break;
		default:
			break;
		}
	}

	return widen_string(buf, buf - buf_start, end, spec);
}

1647 1648 1649 1650 1651
/*
 * 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.
 *
1652 1653 1654
 * Please update scripts/checkpatch.pl when adding/removing conversion
 * characters.  (Search for "check for vsprintf extension").
 *
1655 1656
 * Right now we handle:
 *
1657 1658
 * - 'F' For symbolic function descriptor pointers with offset
 * - 'f' For simple symbolic function names without offset
1659 1660
 * - 'S' For symbolic direct pointers with offset
 * - 's' For symbolic direct pointers without offset
1661
 * - '[FfSs]R' as above with __builtin_extract_return_addr() translation
1662
 * - 'B' For backtraced symbolic direct pointers with offset
1663 1664
 * - 'R' For decoded struct resource, e.g., [mem 0x0-0x1f 64bit pref]
 * - 'r' For raw struct resource, e.g., [mem 0x0-0x1f flags 0x201]
1665 1666 1667 1668
 * - '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
1669 1670
 * - 'M' For a 6-byte MAC address, it prints the address in the
 *       usual colon-separated hex notation
1671
 * - 'm' For a 6-byte MAC address, it prints the hex address without colons
1672
 * - 'MF' For a 6-byte MAC FDDI address, it prints the address
1673
 *       with a dash-separated hex notation
1674
 * - '[mM]R' For a 6-byte MAC address, Reverse order (Bluetooth)
1675 1676 1677
 * - '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
1678 1679 1680
 *       [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]
1681 1682 1683
 * - '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)
1684 1685 1686 1687 1688
 *       [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
1689
 *       http://tools.ietf.org/html/rfc5952
1690 1691 1692 1693 1694 1695 1696 1697 1698 1699 1700
 * - '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.
1701 1702 1703 1704 1705 1706 1707 1708 1709 1710 1711
 * - '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]
1712 1713 1714 1715 1716
 * - '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.
1717
 * - 'K' For a kernel pointer that should be hidden from unprivileged users
1718
 * - 'NF' For a netdev_features_t
1719 1720 1721 1722 1723 1724 1725
 * - '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.
1726 1727
 * - '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)
1728 1729
 * - 'd[234]' For a dentry name (optionally 2-4 last components)
 * - 'D[234]' Same as 'd' but for a struct file
1730
 * - 'g' For block_device name (gendisk + partition number)
1731 1732 1733 1734 1735
 * - '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
1736 1737 1738 1739 1740
 * - '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
1741 1742 1743 1744 1745 1746 1747 1748 1749 1750
 * - 'O' For a kobject based struct. Must be one of the following:
 *       - 'OF[fnpPcCF]'  For a device tree object
 *                        Without any optional arguments prints the full_name
 *                        f device node full_name
 *                        n device node name
 *                        p device node phandle
 *                        P device node path spec (name + @unit)
 *                        F device node flags
 *                        c major compatible string
 *                        C full compatible string
1751 1752
 *
 * ** Please update also Documentation/printk-formats.txt when making changes **
1753
 *
1754 1755 1756
 * 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.
1757
 */
J
Joe Perches 已提交
1758 1759 1760
static noinline_for_stack
char *pointer(const char *fmt, char *buf, char *end, void *ptr,
	      struct printf_spec spec)
1761
{
1762
	const int default_width = 2 * sizeof(void *);
1763

1764
	if (!ptr && *fmt != 'K') {
1765 1766 1767 1768 1769
		/*
		 * Print (null) with the same width as a pointer so it makes
		 * tabular output look nice.
		 */
		if (spec.field_width == -1)
1770
			spec.field_width = default_width;
1771
		return string(buf, end, "(null)", spec);
1772
	}
1773

1774 1775
	switch (*fmt) {
	case 'F':
1776
	case 'f':
1777 1778 1779
		ptr = dereference_function_descriptor(ptr);
		/* Fallthrough */
	case 'S':
1780
	case 's':
1781
	case 'B':
1782
		return symbol_string(buf, end, ptr, spec, fmt);
1783
	case 'R':
1784
	case 'r':
1785
		return resource_string(buf, end, ptr, spec, fmt);
1786 1787
	case 'h':
		return hex_string(buf, end, ptr, spec, fmt);
1788 1789 1790 1791 1792 1793 1794
	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);
		}
1795 1796
	case 'M':			/* Colon separated: 00:01:02:03:04:05 */
	case 'm':			/* Contiguous: 000102030405 */
1797 1798
					/* [mM]F (FDDI) */
					/* [mM]R (Reverse order; Bluetooth) */
1799 1800 1801 1802 1803 1804 1805 1806 1807 1808 1809 1810 1811 1812 1813
		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);
1814 1815 1816 1817 1818 1819 1820 1821 1822 1823 1824 1825 1826 1827 1828
		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);
			}}
1829
		}
1830
		break;
1831 1832
	case 'E':
		return escaped_string(buf, end, ptr, spec, fmt);
1833 1834
	case 'U':
		return uuid_string(buf, end, ptr, spec, fmt);
1835
	case 'V':
1836 1837 1838 1839 1840 1841 1842 1843 1844
		{
			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;
		}
1845
	case 'K':
1846
		return restricted_pointer(buf, end, ptr, spec);
1847
	case 'N':
1848
		return netdev_bits(buf, end, ptr, fmt);
1849
	case 'a':
1850
		return address_val(buf, end, ptr, fmt);
A
Al Viro 已提交
1851 1852
	case 'd':
		return dentry_name(buf, end, ptr, spec, fmt);
1853 1854
	case 'C':
		return clock(buf, end, ptr, spec, fmt);
A
Al Viro 已提交
1855 1856 1857 1858
	case 'D':
		return dentry_name(buf, end,
				   ((const struct file *)ptr)->f_path.dentry,
				   spec, fmt);
1859 1860 1861 1862 1863
#ifdef CONFIG_BLOCK
	case 'g':
		return bdev_name(buf, end, ptr, spec, fmt);
#endif

1864 1865
	case 'G':
		return flags_string(buf, end, ptr, fmt);
1866 1867 1868 1869 1870
	case 'O':
		switch (fmt[1]) {
		case 'F':
			return device_node_string(buf, end, ptr, spec, fmt + 1);
		}
1871 1872 1873
	}
	spec.flags |= SMALL;
	if (spec.field_width == -1) {
1874
		spec.field_width = default_width;
1875 1876 1877 1878 1879 1880 1881 1882 1883 1884 1885 1886 1887 1888 1889 1890 1891
		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
1892
 * 'Z' changed to 'z' --adobriyan 2017-01-25
1893 1894 1895 1896 1897 1898 1899 1900 1901 1902
 * '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, ...)
 */
J
Joe Perches 已提交
1903 1904
static noinline_for_stack
int format_decode(const char *fmt, struct printf_spec *spec)
1905 1906
{
	const char *start = fmt;
1907
	char qualifier;
1908 1909

	/* we finished early by reading the field width */
1910
	if (spec->type == FORMAT_TYPE_WIDTH) {
1911 1912 1913 1914 1915 1916 1917 1918 1919 1920 1921 1922 1923 1924 1925 1926 1927 1928 1929 1930 1931 1932 1933 1934 1935 1936 1937 1938 1939 1940 1941 1942 1943 1944 1945 1946 1947 1948 1949 1950 1951 1952 1953 1954 1955 1956 1957 1958 1959 1960 1961 1962 1963 1964 1965 1966 1967
		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 */
1968
		spec->type = FORMAT_TYPE_WIDTH;
1969 1970 1971 1972 1973 1974 1975 1976 1977 1978 1979 1980 1981 1982
		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 */
1983
			spec->type = FORMAT_TYPE_PRECISION;
1984 1985 1986 1987 1988 1989
			return ++fmt - start;
		}
	}

qualifier:
	/* get the conversion qualifier */
1990
	qualifier = 0;
A
Andy Shevchenko 已提交
1991
	if (*fmt == 'h' || _tolower(*fmt) == 'l' ||
1992
	    *fmt == 'z' || *fmt == 't') {
1993 1994 1995 1996
		qualifier = *fmt++;
		if (unlikely(qualifier == *fmt)) {
			if (qualifier == 'l') {
				qualifier = 'L';
1997
				++fmt;
1998 1999
			} else if (qualifier == 'h') {
				qualifier = 'H';
2000 2001
				++fmt;
			}
2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017
		}
	}

	/* 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;
2018
		return ++fmt - start;
2019 2020 2021 2022 2023 2024 2025 2026 2027 2028 2029 2030 2031 2032 2033 2034 2035 2036 2037

	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':
2038
		spec->flags |= SIGN;
2039
	case 'u':
2040
		break;
2041

R
Ryan Mallon 已提交
2042 2043
	case 'n':
		/*
2044 2045 2046
		 * Since %n poses a greater security risk than
		 * utility, treat it as any other invalid or
		 * unsupported format specifier.
R
Ryan Mallon 已提交
2047 2048 2049
		 */
		/* Fall-through */

2050
	default:
2051
		WARN_ONCE(1, "Please remove unsupported %%%c in format string\n", *fmt);
2052 2053
		spec->type = FORMAT_TYPE_INVALID;
		return fmt - start;
2054
	}
2055

2056
	if (qualifier == 'L')
2057
		spec->type = FORMAT_TYPE_LONG_LONG;
2058
	else if (qualifier == 'l') {
2059 2060
		BUILD_BUG_ON(FORMAT_TYPE_ULONG + SIGN != FORMAT_TYPE_LONG);
		spec->type = FORMAT_TYPE_ULONG + (spec->flags & SIGN);
2061
	} else if (qualifier == 'z') {
2062
		spec->type = FORMAT_TYPE_SIZE_T;
2063
	} else if (qualifier == 't') {
2064
		spec->type = FORMAT_TYPE_PTRDIFF;
2065
	} else if (qualifier == 'H') {
2066 2067
		BUILD_BUG_ON(FORMAT_TYPE_UBYTE + SIGN != FORMAT_TYPE_BYTE);
		spec->type = FORMAT_TYPE_UBYTE + (spec->flags & SIGN);
2068
	} else if (qualifier == 'h') {
2069 2070
		BUILD_BUG_ON(FORMAT_TYPE_USHORT + SIGN != FORMAT_TYPE_SHORT);
		spec->type = FORMAT_TYPE_USHORT + (spec->flags & SIGN);
2071
	} else {
2072 2073
		BUILD_BUG_ON(FORMAT_TYPE_UINT + SIGN != FORMAT_TYPE_INT);
		spec->type = FORMAT_TYPE_UINT + (spec->flags & SIGN);
2074
	}
2075 2076

	return ++fmt - start;
2077 2078
}

2079 2080 2081 2082 2083 2084 2085 2086 2087 2088 2089 2090 2091 2092 2093 2094 2095 2096
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);
	}
}

L
Linus Torvalds 已提交
2097 2098 2099 2100 2101 2102 2103
/**
 * 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
 *
2104 2105 2106
 * This function generally follows C99 vsnprintf, but has some
 * extensions and a few limitations:
 *
2107 2108
 *  - ``%n`` is unsupported
 *  - ``%p*`` is handled by pointer()
2109 2110 2111
 *
 * See pointer() or Documentation/printk-formats.txt for more
 * extensive description.
2112
 *
2113
 * **Please update the documentation in both places when making changes**
2114
 *
L
Linus Torvalds 已提交
2115 2116 2117 2118
 * 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
2119
 * (not including the trailing '\0'), use vscnprintf(). If the
L
Linus Torvalds 已提交
2120 2121 2122
 * return is greater than or equal to @size, the resulting
 * string is truncated.
 *
2123
 * If you're not already dealing with a va_list consider using snprintf().
L
Linus Torvalds 已提交
2124 2125 2126 2127
 */
int vsnprintf(char *buf, size_t size, const char *fmt, va_list args)
{
	unsigned long long num;
2128
	char *str, *end;
2129
	struct printf_spec spec = {0};
L
Linus Torvalds 已提交
2130

2131 2132
	/* Reject out-of-range values early.  Large positive sizes are
	   used for unknown buffer sizes. */
2133
	if (WARN_ON_ONCE(size > INT_MAX))
L
Linus Torvalds 已提交
2134 2135 2136
		return 0;

	str = buf;
2137
	end = buf + size;
L
Linus Torvalds 已提交
2138

2139 2140 2141 2142
	/* Make sure end is always >= buf */
	if (end < buf) {
		end = ((void *)-1);
		size = end - buf;
L
Linus Torvalds 已提交
2143 2144
	}

2145 2146
	while (*fmt) {
		const char *old_fmt = fmt;
2147
		int read = format_decode(fmt, &spec);
L
Linus Torvalds 已提交
2148

2149
		fmt += read;
L
Linus Torvalds 已提交
2150

2151 2152 2153 2154 2155 2156 2157
		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);
L
Linus Torvalds 已提交
2158
			}
2159 2160
			str += read;
			break;
L
Linus Torvalds 已提交
2161 2162
		}

2163
		case FORMAT_TYPE_WIDTH:
2164
			set_field_width(&spec, va_arg(args, int));
2165
			break;
L
Linus Torvalds 已提交
2166

2167
		case FORMAT_TYPE_PRECISION:
2168
			set_precision(&spec, va_arg(args, int));
2169
			break;
L
Linus Torvalds 已提交
2170

2171 2172 2173
		case FORMAT_TYPE_CHAR: {
			char c;

2174 2175
			if (!(spec.flags & LEFT)) {
				while (--spec.field_width > 0) {
2176
					if (str < end)
L
Linus Torvalds 已提交
2177 2178 2179
						*str = ' ';
					++str;

2180 2181 2182 2183 2184 2185 2186
				}
			}
			c = (unsigned char) va_arg(args, int);
			if (str < end)
				*str = c;
			++str;
			while (--spec.field_width > 0) {
2187
				if (str < end)
2188
					*str = ' ';
L
Linus Torvalds 已提交
2189
				++str;
2190 2191
			}
			break;
2192
		}
L
Linus Torvalds 已提交
2193

2194 2195 2196
		case FORMAT_TYPE_STR:
			str = string(str, end, va_arg(args, char *), spec);
			break;
L
Linus Torvalds 已提交
2197

2198
		case FORMAT_TYPE_PTR:
2199
			str = pointer(fmt, str, end, va_arg(args, void *),
2200 2201 2202 2203
				      spec);
			while (isalnum(*fmt))
				fmt++;
			break;
L
Linus Torvalds 已提交
2204

2205 2206 2207 2208 2209
		case FORMAT_TYPE_PERCENT_CHAR:
			if (str < end)
				*str = '%';
			++str;
			break;
L
Linus Torvalds 已提交
2210

2211
		case FORMAT_TYPE_INVALID:
2212 2213 2214 2215 2216 2217 2218 2219 2220
			/*
			 * 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;
2221 2222 2223 2224 2225 2226 2227 2228 2229 2230 2231 2232 2233

		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:
2234 2235 2236 2237
				if (spec.flags & SIGN)
					num = va_arg(args, ssize_t);
				else
					num = va_arg(args, size_t);
2238 2239 2240 2241
				break;
			case FORMAT_TYPE_PTRDIFF:
				num = va_arg(args, ptrdiff_t);
				break;
2242 2243 2244 2245 2246 2247
			case FORMAT_TYPE_UBYTE:
				num = (unsigned char) va_arg(args, int);
				break;
			case FORMAT_TYPE_BYTE:
				num = (signed char) va_arg(args, int);
				break;
2248 2249 2250 2251 2252 2253
			case FORMAT_TYPE_USHORT:
				num = (unsigned short) va_arg(args, int);
				break;
			case FORMAT_TYPE_SHORT:
				num = (short) va_arg(args, int);
				break;
2254 2255
			case FORMAT_TYPE_INT:
				num = (int) va_arg(args, int);
2256 2257 2258 2259 2260 2261
				break;
			default:
				num = va_arg(args, unsigned int);
			}

			str = number(str, end, num, spec);
L
Linus Torvalds 已提交
2262 2263
		}
	}
2264

2265
out:
2266 2267 2268 2269
	if (size > 0) {
		if (str < end)
			*str = '\0';
		else
L
Linus Torvalds 已提交
2270
			end[-1] = '\0';
2271
	}
2272

2273
	/* the trailing null byte doesn't count towards the total */
L
Linus Torvalds 已提交
2274
	return str-buf;
2275

L
Linus Torvalds 已提交
2276 2277 2278 2279 2280 2281 2282 2283 2284 2285 2286
}
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
2287
 * the @buf not including the trailing '\0'. If @size is == 0 the function
L
Linus Torvalds 已提交
2288 2289
 * returns 0.
 *
2290
 * If you're not already dealing with a va_list consider using scnprintf().
2291 2292
 *
 * See the vsnprintf() documentation for format string extensions over C99.
L
Linus Torvalds 已提交
2293 2294 2295 2296 2297
 */
int vscnprintf(char *buf, size_t size, const char *fmt, va_list args)
{
	int i;

2298 2299
	i = vsnprintf(buf, size, fmt, args);

2300 2301 2302 2303 2304
	if (likely(i < size))
		return i;
	if (size != 0)
		return size - 1;
	return 0;
L
Linus Torvalds 已提交
2305 2306 2307 2308 2309 2310 2311 2312 2313 2314 2315 2316 2317 2318
}
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.
2319 2320
 *
 * See the vsnprintf() documentation for format string extensions over C99.
L
Linus Torvalds 已提交
2321
 */
2322
int snprintf(char *buf, size_t size, const char *fmt, ...)
L
Linus Torvalds 已提交
2323 2324 2325 2326 2327
{
	va_list args;
	int i;

	va_start(args, fmt);
2328
	i = vsnprintf(buf, size, fmt, args);
L
Linus Torvalds 已提交
2329
	va_end(args);
2330

L
Linus Torvalds 已提交
2331 2332 2333 2334 2335 2336 2337 2338 2339 2340 2341 2342
	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
2343
 * the trailing '\0'. If @size is == 0 the function returns 0.
L
Linus Torvalds 已提交
2344 2345
 */

2346
int scnprintf(char *buf, size_t size, const char *fmt, ...)
L
Linus Torvalds 已提交
2347 2348 2349 2350 2351
{
	va_list args;
	int i;

	va_start(args, fmt);
2352
	i = vscnprintf(buf, size, fmt, args);
L
Linus Torvalds 已提交
2353
	va_end(args);
2354

2355
	return i;
L
Linus Torvalds 已提交
2356 2357 2358 2359 2360 2361 2362 2363 2364 2365
}
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
2366
 * into @buf. Use vsnprintf() or vscnprintf() in order to avoid
L
Linus Torvalds 已提交
2367 2368
 * buffer overflows.
 *
2369
 * If you're not already dealing with a va_list consider using sprintf().
2370 2371
 *
 * See the vsnprintf() documentation for format string extensions over C99.
L
Linus Torvalds 已提交
2372 2373 2374 2375 2376 2377 2378 2379 2380 2381 2382 2383 2384 2385
 */
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
2386
 * into @buf. Use snprintf() or scnprintf() in order to avoid
L
Linus Torvalds 已提交
2387
 * buffer overflows.
2388 2389
 *
 * See the vsnprintf() documentation for format string extensions over C99.
L
Linus Torvalds 已提交
2390
 */
2391
int sprintf(char *buf, const char *fmt, ...)
L
Linus Torvalds 已提交
2392 2393 2394 2395 2396
{
	va_list args;
	int i;

	va_start(args, fmt);
2397
	i = vsnprintf(buf, INT_MAX, fmt, args);
L
Linus Torvalds 已提交
2398
	va_end(args);
2399

L
Linus Torvalds 已提交
2400 2401 2402 2403
	return i;
}
EXPORT_SYMBOL(sprintf);

L
Lai Jiangshan 已提交
2404 2405 2406 2407 2408 2409 2410 2411 2412 2413 2414 2415 2416 2417 2418
#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
2419
 * is skipped.
L
Lai Jiangshan 已提交
2420 2421 2422 2423 2424 2425 2426 2427 2428 2429
 *
 * 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)
{
2430
	struct printf_spec spec = {0};
L
Lai Jiangshan 已提交
2431 2432 2433 2434 2435 2436 2437 2438 2439 2440 2441 2442 2443 2444 2445 2446 2447 2448 2449 2450 2451 2452 2453 2454 2455
	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)

2456
	while (*fmt) {
2457
		int read = format_decode(fmt, &spec);
L
Lai Jiangshan 已提交
2458

2459
		fmt += read;
L
Lai Jiangshan 已提交
2460

2461 2462
		switch (spec.type) {
		case FORMAT_TYPE_NONE:
2463
		case FORMAT_TYPE_PERCENT_CHAR:
2464
			break;
2465 2466
		case FORMAT_TYPE_INVALID:
			goto out;
2467

2468
		case FORMAT_TYPE_WIDTH:
2469 2470 2471 2472 2473
		case FORMAT_TYPE_PRECISION:
			save_arg(int);
			break;

		case FORMAT_TYPE_CHAR:
L
Lai Jiangshan 已提交
2474
			save_arg(char);
2475 2476 2477
			break;

		case FORMAT_TYPE_STR: {
L
Lai Jiangshan 已提交
2478 2479
			const char *save_str = va_arg(args, char *);
			size_t len;
2480

L
Lai Jiangshan 已提交
2481 2482
			if ((unsigned long)save_str > (unsigned long)-PAGE_SIZE
					|| (unsigned long)save_str < PAGE_SIZE)
2483
				save_str = "(null)";
2484 2485 2486 2487
			len = strlen(save_str) + 1;
			if (str + len < end)
				memcpy(str, save_str, len);
			str += len;
2488
			break;
L
Lai Jiangshan 已提交
2489
		}
2490 2491

		case FORMAT_TYPE_PTR:
L
Lai Jiangshan 已提交
2492 2493
			save_arg(void *);
			/* skip all alphanumeric pointer suffixes */
2494
			while (isalnum(*fmt))
L
Lai Jiangshan 已提交
2495
				fmt++;
2496 2497 2498 2499 2500 2501
			break;

		default:
			switch (spec.type) {

			case FORMAT_TYPE_LONG_LONG:
L
Lai Jiangshan 已提交
2502
				save_arg(long long);
2503 2504 2505
				break;
			case FORMAT_TYPE_ULONG:
			case FORMAT_TYPE_LONG:
L
Lai Jiangshan 已提交
2506
				save_arg(unsigned long);
2507 2508
				break;
			case FORMAT_TYPE_SIZE_T:
L
Lai Jiangshan 已提交
2509
				save_arg(size_t);
2510 2511
				break;
			case FORMAT_TYPE_PTRDIFF:
L
Lai Jiangshan 已提交
2512
				save_arg(ptrdiff_t);
2513
				break;
2514 2515 2516 2517
			case FORMAT_TYPE_UBYTE:
			case FORMAT_TYPE_BYTE:
				save_arg(char);
				break;
2518 2519
			case FORMAT_TYPE_USHORT:
			case FORMAT_TYPE_SHORT:
L
Lai Jiangshan 已提交
2520
				save_arg(short);
2521 2522
				break;
			default:
L
Lai Jiangshan 已提交
2523
				save_arg(int);
2524
			}
L
Lai Jiangshan 已提交
2525 2526
		}
	}
2527

2528
out:
2529
	return (u32 *)(PTR_ALIGN(str, sizeof(u32))) - bin_buf;
2530
#undef save_arg
L
Lai Jiangshan 已提交
2531 2532 2533 2534 2535 2536 2537 2538 2539 2540 2541 2542 2543 2544 2545
}
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:
2546
 *  see vsnprintf comment for details.
L
Lai Jiangshan 已提交
2547 2548 2549 2550 2551 2552 2553 2554 2555 2556 2557
 *
 * 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)
{
2558
	struct printf_spec spec = {0};
2559 2560
	char *str, *end;
	const char *args = (const char *)bin_buf;
L
Lai Jiangshan 已提交
2561

2562
	if (WARN_ON_ONCE(size > INT_MAX))
L
Lai Jiangshan 已提交
2563 2564 2565 2566 2567 2568 2569 2570 2571 2572 2573 2574 2575 2576 2577 2578 2579 2580 2581 2582 2583 2584 2585 2586 2587 2588
		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;
	}

2589 2590
	while (*fmt) {
		const char *old_fmt = fmt;
2591
		int read = format_decode(fmt, &spec);
L
Lai Jiangshan 已提交
2592

2593
		fmt += read;
L
Lai Jiangshan 已提交
2594

2595 2596 2597 2598 2599 2600 2601
		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);
L
Lai Jiangshan 已提交
2602
			}
2603 2604
			str += read;
			break;
L
Lai Jiangshan 已提交
2605 2606
		}

2607
		case FORMAT_TYPE_WIDTH:
2608
			set_field_width(&spec, get_arg(int));
2609
			break;
L
Lai Jiangshan 已提交
2610

2611
		case FORMAT_TYPE_PRECISION:
2612
			set_precision(&spec, get_arg(int));
2613
			break;
L
Lai Jiangshan 已提交
2614

2615 2616 2617
		case FORMAT_TYPE_CHAR: {
			char c;

2618 2619
			if (!(spec.flags & LEFT)) {
				while (--spec.field_width > 0) {
L
Lai Jiangshan 已提交
2620 2621 2622 2623 2624 2625 2626 2627 2628
					if (str < end)
						*str = ' ';
					++str;
				}
			}
			c = (unsigned char) get_arg(char);
			if (str < end)
				*str = c;
			++str;
2629
			while (--spec.field_width > 0) {
L
Lai Jiangshan 已提交
2630 2631 2632 2633
				if (str < end)
					*str = ' ';
				++str;
			}
2634
			break;
2635
		}
L
Lai Jiangshan 已提交
2636

2637
		case FORMAT_TYPE_STR: {
L
Lai Jiangshan 已提交
2638
			const char *str_arg = args;
2639
			args += strlen(str_arg) + 1;
2640 2641
			str = string(str, end, (char *)str_arg, spec);
			break;
L
Lai Jiangshan 已提交
2642 2643
		}

2644
		case FORMAT_TYPE_PTR:
2645
			str = pointer(fmt, str, end, get_arg(void *), spec);
2646
			while (isalnum(*fmt))
L
Lai Jiangshan 已提交
2647
				fmt++;
2648
			break;
L
Lai Jiangshan 已提交
2649

2650
		case FORMAT_TYPE_PERCENT_CHAR:
L
Lai Jiangshan 已提交
2651 2652 2653
			if (str < end)
				*str = '%';
			++str;
2654 2655
			break;

2656 2657 2658
		case FORMAT_TYPE_INVALID:
			goto out;

2659 2660 2661
		default: {
			unsigned long long num;

2662 2663 2664 2665 2666 2667 2668 2669 2670 2671 2672 2673 2674 2675 2676
			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;
2677 2678 2679 2680 2681 2682
			case FORMAT_TYPE_UBYTE:
				num = get_arg(unsigned char);
				break;
			case FORMAT_TYPE_BYTE:
				num = get_arg(signed char);
				break;
2683 2684 2685 2686 2687 2688 2689 2690 2691 2692 2693 2694 2695 2696
			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);
2697 2698 2699
		} /* default: */
		} /* switch(spec.type) */
	} /* while(*fmt) */
2700

2701
out:
L
Lai Jiangshan 已提交
2702 2703 2704 2705 2706 2707
	if (size > 0) {
		if (str < end)
			*str = '\0';
		else
			end[-1] = '\0';
	}
2708

L
Lai Jiangshan 已提交
2709 2710 2711 2712 2713 2714 2715 2716 2717 2718 2719 2720 2721 2722 2723 2724 2725 2726 2727 2728 2729 2730 2731 2732 2733
#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);
2734

L
Lai Jiangshan 已提交
2735 2736 2737 2738 2739 2740
	return ret;
}
EXPORT_SYMBOL_GPL(bprintf);

#endif /* CONFIG_BINARY_PRINTF */

L
Linus Torvalds 已提交
2741 2742 2743 2744 2745 2746
/**
 * vsscanf - Unformat a buffer into a list of arguments
 * @buf:	input buffer
 * @fmt:	format of buffer
 * @args:	arguments
 */
2747
int vsscanf(const char *buf, const char *fmt, va_list args)
L
Linus Torvalds 已提交
2748 2749 2750 2751 2752
{
	const char *str = buf;
	char *next;
	char digit;
	int num = 0;
2753
	u8 qualifier;
2754 2755 2756 2757 2758
	unsigned int base;
	union {
		long long s;
		unsigned long long u;
	} val;
2759
	s16 field_width;
2760
	bool is_sign;
L
Linus Torvalds 已提交
2761

2762
	while (*fmt) {
L
Linus Torvalds 已提交
2763 2764 2765 2766 2767
		/* skip any white space in format */
		/* white space in format matchs any amount of
		 * white space, including none, in the input.
		 */
		if (isspace(*fmt)) {
2768 2769
			fmt = skip_spaces(++fmt);
			str = skip_spaces(str);
L
Linus Torvalds 已提交
2770 2771 2772 2773 2774 2775 2776 2777 2778 2779 2780 2781
		}

		/* anything that is not a conversion must match exactly */
		if (*fmt != '%' && *fmt) {
			if (*fmt++ != *str++)
				break;
			continue;
		}

		if (!*fmt)
			break;
		++fmt;
2782

L
Linus Torvalds 已提交
2783 2784 2785 2786
		/* skip this conversion.
		 * advance both strings to next white space
		 */
		if (*fmt == '*') {
2787 2788
			if (!*str)
				break;
2789 2790 2791 2792
			while (!isspace(*fmt) && *fmt != '%' && *fmt) {
				/* '%*[' not yet supported, invalid format */
				if (*fmt == '[')
					return num;
L
Linus Torvalds 已提交
2793
				fmt++;
2794
			}
L
Linus Torvalds 已提交
2795 2796 2797 2798 2799 2800 2801
			while (!isspace(*str) && *str)
				str++;
			continue;
		}

		/* get field width */
		field_width = -1;
2802
		if (isdigit(*fmt)) {
L
Linus Torvalds 已提交
2803
			field_width = skip_atoi(&fmt);
2804 2805 2806
			if (field_width <= 0)
				break;
		}
L
Linus Torvalds 已提交
2807 2808 2809

		/* get conversion qualifier */
		qualifier = -1;
A
Andy Shevchenko 已提交
2810
		if (*fmt == 'h' || _tolower(*fmt) == 'l' ||
2811
		    *fmt == 'z') {
L
Linus Torvalds 已提交
2812 2813 2814 2815 2816 2817 2818 2819 2820 2821 2822 2823
			qualifier = *fmt++;
			if (unlikely(qualifier == *fmt)) {
				if (qualifier == 'h') {
					qualifier = 'H';
					fmt++;
				} else if (qualifier == 'l') {
					qualifier = 'L';
					fmt++;
				}
			}
		}

2824 2825 2826 2827 2828 2829 2830 2831 2832 2833 2834
		if (!*fmt)
			break;

		if (*fmt == 'n') {
			/* return number of characters read so far */
			*va_arg(args, int *) = str - buf;
			++fmt;
			continue;
		}

		if (!*str)
L
Linus Torvalds 已提交
2835 2836
			break;

2837
		base = 10;
2838
		is_sign = false;
2839

2840
		switch (*fmt++) {
L
Linus Torvalds 已提交
2841 2842
		case 'c':
		{
2843
			char *s = (char *)va_arg(args, char*);
L
Linus Torvalds 已提交
2844 2845 2846 2847 2848 2849 2850 2851 2852 2853
			if (field_width == -1)
				field_width = 1;
			do {
				*s++ = *str++;
			} while (--field_width > 0 && *str);
			num++;
		}
		continue;
		case 's':
		{
2854 2855
			char *s = (char *)va_arg(args, char *);
			if (field_width == -1)
2856
				field_width = SHRT_MAX;
L
Linus Torvalds 已提交
2857
			/* first, skip leading white space in buffer */
2858
			str = skip_spaces(str);
L
Linus Torvalds 已提交
2859 2860

			/* now copy until next white space */
2861
			while (*str && !isspace(*str) && field_width--)
L
Linus Torvalds 已提交
2862 2863 2864 2865 2866
				*s++ = *str++;
			*s = '\0';
			num++;
		}
		continue;
2867 2868 2869 2870 2871 2872 2873 2874 2875 2876 2877 2878 2879 2880 2881 2882 2883 2884 2885 2886 2887 2888 2889 2890 2891 2892 2893 2894 2895 2896 2897 2898 2899 2900 2901 2902 2903 2904 2905 2906 2907 2908 2909 2910 2911 2912 2913 2914 2915 2916 2917 2918 2919
		/*
		 * Warning: This implementation of the '[' conversion specifier
		 * deviates from its glibc counterpart in the following ways:
		 * (1) It does NOT support ranges i.e. '-' is NOT a special
		 *     character
		 * (2) It cannot match the closing bracket ']' itself
		 * (3) A field width is required
		 * (4) '%*[' (discard matching input) is currently not supported
		 *
		 * Example usage:
		 * ret = sscanf("00:0a:95","%2[^:]:%2[^:]:%2[^:]",
		 *		buf1, buf2, buf3);
		 * if (ret < 3)
		 *    // etc..
		 */
		case '[':
		{
			char *s = (char *)va_arg(args, char *);
			DECLARE_BITMAP(set, 256) = {0};
			unsigned int len = 0;
			bool negate = (*fmt == '^');

			/* field width is required */
			if (field_width == -1)
				return num;

			if (negate)
				++fmt;

			for ( ; *fmt && *fmt != ']'; ++fmt, ++len)
				set_bit((u8)*fmt, set);

			/* no ']' or no character set found */
			if (!*fmt || !len)
				return num;
			++fmt;

			if (negate) {
				bitmap_complement(set, set, 256);
				/* exclude null '\0' byte */
				clear_bit(0, set);
			}

			/* match must be non-empty */
			if (!test_bit((u8)*str, set))
				return num;

			while (test_bit((u8)*str, set) && field_width--)
				*s++ = *str++;
			*s = '\0';
			++num;
		}
		continue;
L
Linus Torvalds 已提交
2920 2921 2922 2923 2924 2925 2926 2927
		case 'o':
			base = 8;
			break;
		case 'x':
		case 'X':
			base = 16;
			break;
		case 'i':
2928
			base = 0;
L
Linus Torvalds 已提交
2929
		case 'd':
2930
			is_sign = true;
L
Linus Torvalds 已提交
2931 2932 2933 2934
		case 'u':
			break;
		case '%':
			/* looking for '%' in str */
2935
			if (*str++ != '%')
L
Linus Torvalds 已提交
2936 2937 2938 2939 2940 2941 2942 2943 2944 2945
				return num;
			continue;
		default:
			/* invalid format; stop here */
			return num;
		}

		/* have some sort of integer conversion.
		 * first, skip white space in buffer.
		 */
2946
		str = skip_spaces(str);
L
Linus Torvalds 已提交
2947 2948 2949 2950 2951 2952

		digit = *str;
		if (is_sign && digit == '-')
			digit = *(str + 1);

		if (!digit
2953 2954 2955 2956 2957
		    || (base == 16 && !isxdigit(digit))
		    || (base == 10 && !isdigit(digit))
		    || (base == 8 && (!isdigit(digit) || digit > '7'))
		    || (base == 0 && !isdigit(digit)))
			break;
L
Linus Torvalds 已提交
2958

2959 2960 2961 2962 2963 2964 2965 2966 2967 2968 2969 2970 2971 2972 2973 2974 2975 2976 2977 2978 2979
		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;
			}
		}

2980
		switch (qualifier) {
L
Linus Torvalds 已提交
2981
		case 'H':	/* that's 'hh' in format */
2982 2983 2984 2985
			if (is_sign)
				*va_arg(args, signed char *) = val.s;
			else
				*va_arg(args, unsigned char *) = val.u;
L
Linus Torvalds 已提交
2986 2987
			break;
		case 'h':
2988 2989 2990 2991
			if (is_sign)
				*va_arg(args, short *) = val.s;
			else
				*va_arg(args, unsigned short *) = val.u;
L
Linus Torvalds 已提交
2992 2993
			break;
		case 'l':
2994 2995 2996 2997
			if (is_sign)
				*va_arg(args, long *) = val.s;
			else
				*va_arg(args, unsigned long *) = val.u;
L
Linus Torvalds 已提交
2998 2999
			break;
		case 'L':
3000 3001 3002 3003
			if (is_sign)
				*va_arg(args, long long *) = val.s;
			else
				*va_arg(args, unsigned long long *) = val.u;
L
Linus Torvalds 已提交
3004 3005
			break;
		case 'z':
3006 3007
			*va_arg(args, size_t *) = val.u;
			break;
L
Linus Torvalds 已提交
3008
		default:
3009 3010 3011 3012
			if (is_sign)
				*va_arg(args, int *) = val.s;
			else
				*va_arg(args, unsigned int *) = val.u;
L
Linus Torvalds 已提交
3013 3014 3015 3016 3017 3018 3019 3020
			break;
		}
		num++;

		if (!next)
			break;
		str = next;
	}
3021

L
Linus Torvalds 已提交
3022 3023 3024 3025 3026 3027 3028 3029 3030 3031
	return num;
}
EXPORT_SYMBOL(vsscanf);

/**
 * sscanf - Unformat a buffer into a list of arguments
 * @buf:	input buffer
 * @fmt:	formatting of buffer
 * @...:	resulting arguments
 */
3032
int sscanf(const char *buf, const char *fmt, ...)
L
Linus Torvalds 已提交
3033 3034 3035 3036
{
	va_list args;
	int i;

3037 3038
	va_start(args, fmt);
	i = vsscanf(buf, fmt, args);
L
Linus Torvalds 已提交
3039
	va_end(args);
3040

L
Linus Torvalds 已提交
3041 3042 3043
	return i;
}
EXPORT_SYMBOL(sscanf);