vsprintf.c 76.6 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/rtc.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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#include <linux/siphash.h>
#include <linux/compiler.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/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.
 */
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int num_to_str(char *buf, int size, unsigned long long num, unsigned int width)
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{
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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 || width > size)
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		return 0;
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	if (width > len) {
		width = width - len;
		for (idx = 0; idx < width; idx++)
			buf[idx] = ' ';
	} else {
		width = 0;
	}

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	for (idx = 0; idx < len; ++idx)
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		buf[idx + width] = tmp[len - idx - 1];

	return len + width;
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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;
}

595 596 597
static noinline_for_stack
char *string(char *buf, char *end, const char *s, struct printf_spec spec)
{
598 599
	int len = 0;
	size_t lim = spec.precision;
600 601 602 603

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

604 605 606 607
	while (lim--) {
		char c = *s++;
		if (!c)
			break;
608
		if (buf < end)
609
			*buf = c;
610
		++buf;
611
		++len;
612
	}
613
	return widen_string(buf, len, end, spec);
614 615
}

616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718
static noinline_for_stack
char *pointer_string(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;
	}

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

/* Make pointers available for printing early in the boot sequence. */
static int debug_boot_weak_hash __ro_after_init;

static int __init debug_boot_weak_hash_enable(char *str)
{
	debug_boot_weak_hash = 1;
	pr_info("debug_boot_weak_hash enabled\n");
	return 0;
}
early_param("debug_boot_weak_hash", debug_boot_weak_hash_enable);

static DEFINE_STATIC_KEY_TRUE(not_filled_random_ptr_key);
static siphash_key_t ptr_key __read_mostly;

static void enable_ptr_key_workfn(struct work_struct *work)
{
	get_random_bytes(&ptr_key, sizeof(ptr_key));
	/* Needs to run from preemptible context */
	static_branch_disable(&not_filled_random_ptr_key);
}

static DECLARE_WORK(enable_ptr_key_work, enable_ptr_key_workfn);

static void fill_random_ptr_key(struct random_ready_callback *unused)
{
	/* This may be in an interrupt handler. */
	queue_work(system_unbound_wq, &enable_ptr_key_work);
}

static struct random_ready_callback random_ready = {
	.func = fill_random_ptr_key
};

static int __init initialize_ptr_random(void)
{
	int key_size = sizeof(ptr_key);
	int ret;

	/* Use hw RNG if available. */
	if (get_random_bytes_arch(&ptr_key, key_size) == key_size) {
		static_branch_disable(&not_filled_random_ptr_key);
		return 0;
	}

	ret = add_random_ready_callback(&random_ready);
	if (!ret) {
		return 0;
	} else if (ret == -EALREADY) {
		/* This is in preemptible context */
		enable_ptr_key_workfn(&enable_ptr_key_work);
		return 0;
	}

	return ret;
}
early_initcall(initialize_ptr_random);

/* Maps a pointer to a 32 bit unique identifier. */
static char *ptr_to_id(char *buf, char *end, const void *ptr,
		       struct printf_spec spec)
{
	const char *str = sizeof(ptr) == 8 ? "(____ptrval____)" : "(ptrval)";
	unsigned long hashval;

	/* When debugging early boot use non-cryptographically secure hash. */
	if (unlikely(debug_boot_weak_hash)) {
		hashval = hash_long((unsigned long)ptr, 32);
		return pointer_string(buf, end, (const void *)hashval, spec);
	}

	if (static_branch_unlikely(&not_filled_random_ptr_key)) {
		spec.field_width = 2 * sizeof(ptr);
		/* string length must be less than default_width */
		return string(buf, end, str, spec);
	}

#ifdef CONFIG_64BIT
	hashval = (unsigned long)siphash_1u64((u64)ptr, &ptr_key);
	/*
	 * Mask off the first 32 bits, this makes explicit that we have
	 * modified the address (and 32 bits is plenty for a unique ID).
	 */
	hashval = hashval & 0xffffffff;
#else
	hashval = (unsigned long)siphash_1u32((u32)ptr, &ptr_key);
#endif
	return pointer_string(buf, end, (const void *)hashval, spec);
}

719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737
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) {
738 739
		p = READ_ONCE(d->d_parent);
		array[i] = READ_ONCE(d->d_name.name);
740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759
		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();
760
	return widen_string(buf, n, end, spec);
761 762
}

763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782
#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

783 784
static noinline_for_stack
char *symbol_string(char *buf, char *end, void *ptr,
785
		    struct printf_spec spec, const char *fmt)
786
{
787
	unsigned long value;
788 789
#ifdef CONFIG_KALLSYMS
	char sym[KSYM_SYMBOL_LEN];
790 791 792 793 794 795 796 797
#endif

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

#ifdef CONFIG_KALLSYMS
	if (*fmt == 'B')
798
		sprint_backtrace(sym, value);
799
	else if (*fmt != 'f' && *fmt != 's')
800 801
		sprint_symbol(sym, value);
	else
802
		sprint_symbol_no_offset(sym, value);
803

804
	return string(buf, end, sym, spec);
805
#else
806
	return special_hex_number(buf, end, value, sizeof(void *));
807 808 809
#endif
}

810 811 812 813 814
static const struct printf_spec default_str_spec = {
	.field_width = -1,
	.precision = -1,
};

815 816 817 818 819 820
static const struct printf_spec default_flag_spec = {
	.base = 16,
	.precision = -1,
	.flags = SPECIAL | SMALL,
};

821 822 823 824 825
static const struct printf_spec default_dec_spec = {
	.base = 10,
	.precision = -1,
};

826 827 828 829 830 831 832 833 834 835 836 837 838 839
static const struct printf_spec default_dec02_spec = {
	.base = 10,
	.field_width = 2,
	.precision = -1,
	.flags = ZEROPAD,
};

static const struct printf_spec default_dec04_spec = {
	.base = 10,
	.field_width = 4,
	.precision = -1,
	.flags = ZEROPAD,
};

840 841 842
static noinline_for_stack
char *resource_string(char *buf, char *end, struct resource *res,
		      struct printf_spec spec, const char *fmt)
843 844
{
#ifndef IO_RSRC_PRINTK_SIZE
845
#define IO_RSRC_PRINTK_SIZE	6
846 847 848
#endif

#ifndef MEM_RSRC_PRINTK_SIZE
849
#define MEM_RSRC_PRINTK_SIZE	10
850
#endif
851
	static const struct printf_spec io_spec = {
852
		.base = 16,
853
		.field_width = IO_RSRC_PRINTK_SIZE,
854 855 856
		.precision = -1,
		.flags = SPECIAL | SMALL | ZEROPAD,
	};
857 858 859 860 861 862
	static const struct printf_spec mem_spec = {
		.base = 16,
		.field_width = MEM_RSRC_PRINTK_SIZE,
		.precision = -1,
		.flags = SPECIAL | SMALL | ZEROPAD,
	};
863 864 865 866 867 868
	static const struct printf_spec bus_spec = {
		.base = 16,
		.field_width = 2,
		.precision = -1,
		.flags = SMALL | ZEROPAD,
	};
869
	static const struct printf_spec str_spec = {
870 871 872 873
		.field_width = -1,
		.precision = 10,
		.flags = LEFT,
	};
874 875 876 877 878

	/* 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))
879
#define DECODED_BUF_SIZE	sizeof("[mem - 64bit pref window disabled]")
880 881 882 883
#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)];

884
	char *p = sym, *pend = sym + sizeof(sym);
885
	int decode = (fmt[0] == 'R') ? 1 : 0;
886
	const struct printf_spec *specp;
887 888

	*p++ = '[';
889
	if (res->flags & IORESOURCE_IO) {
890
		p = string(p, pend, "io  ", str_spec);
891 892
		specp = &io_spec;
	} else if (res->flags & IORESOURCE_MEM) {
893
		p = string(p, pend, "mem ", str_spec);
894 895
		specp = &mem_spec;
	} else if (res->flags & IORESOURCE_IRQ) {
896
		p = string(p, pend, "irq ", str_spec);
897
		specp = &default_dec_spec;
898
	} else if (res->flags & IORESOURCE_DMA) {
899
		p = string(p, pend, "dma ", str_spec);
900
		specp = &default_dec_spec;
901 902 903
	} else if (res->flags & IORESOURCE_BUS) {
		p = string(p, pend, "bus ", str_spec);
		specp = &bus_spec;
904
	} else {
905
		p = string(p, pend, "??? ", str_spec);
906
		specp = &mem_spec;
907
		decode = 0;
908
	}
909 910 911 912 913 914 915 916 917
	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);
		}
918
	}
919
	if (decode) {
920 921 922 923
		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);
924 925
		if (res->flags & IORESOURCE_WINDOW)
			p = string(p, pend, " window", str_spec);
926 927
		if (res->flags & IORESOURCE_DISABLED)
			p = string(p, pend, " disabled", str_spec);
928 929
	} else {
		p = string(p, pend, " flags ", str_spec);
930
		p = number(p, pend, res->flags, default_flag_spec);
931
	}
932
	*p++ = ']';
933
	*p = '\0';
934

935
	return string(buf, end, sym, spec);
936 937
}

938 939 940 941
static noinline_for_stack
char *hex_string(char *buf, char *end, u8 *addr, struct printf_spec spec,
		 const char *fmt)
{
942
	int i, len = 1;		/* if we pass '%ph[CDN]', field width remains
943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971
				   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);

972 973 974 975 976 977 978
	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;
979

980 981 982 983 984
		if (separator && i != len - 1) {
			if (buf < end)
				*buf = separator;
			++buf;
		}
985 986 987 988 989
	}

	return buf;
}

990 991 992 993 994 995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053
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;

	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;

1054
		buf = number(buf, end, rbot, default_dec_spec);
1055 1056 1057 1058 1059
		if (rbot < rtop) {
			if (buf < end)
				*buf = '-';
			buf++;

1060
			buf = number(buf, end, rtop, default_dec_spec);
1061 1062 1063 1064 1065 1066 1067
		}

		rbot = cur;
	}
	return buf;
}

1068 1069 1070
static noinline_for_stack
char *mac_address_string(char *buf, char *end, u8 *addr,
			 struct printf_spec spec, const char *fmt)
1071
{
1072
	char mac_addr[sizeof("xx:xx:xx:xx:xx:xx")];
1073 1074
	char *p = mac_addr;
	int i;
1075
	char separator;
1076
	bool reversed = false;
1077

1078 1079
	switch (fmt[1]) {
	case 'F':
1080
		separator = '-';
1081 1082 1083 1084 1085 1086 1087
		break;

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

	default:
1088
		separator = ':';
1089
		break;
1090
	}
1091 1092

	for (i = 0; i < 6; i++) {
1093 1094 1095 1096 1097
		if (reversed)
			p = hex_byte_pack(p, addr[5 - i]);
		else
			p = hex_byte_pack(p, addr[i]);

1098
		if (fmt[0] == 'M' && i != 5)
1099
			*p++ = separator;
1100 1101 1102
	}
	*p = '\0';

1103
	return string(buf, end, mac_addr, spec);
1104 1105
}

1106 1107
static noinline_for_stack
char *ip4_string(char *p, const u8 *addr, const char *fmt)
1108 1109
{
	int i;
1110 1111 1112 1113 1114 1115 1116 1117 1118 1119 1120 1121 1122 1123 1124 1125 1126 1127 1128 1129 1130 1131 1132 1133 1134
	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;
	}
1135
	for (i = 0; i < 4; i++) {
1136
		char temp[4] __aligned(2);	/* hold each IP quad in reverse order */
1137
		int digits = put_dec_trunc8(temp, addr[index]) - temp;
1138 1139 1140 1141 1142 1143 1144 1145 1146 1147 1148
		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++ = '.';
1149
		index += step;
1150 1151
	}
	*p = '\0';
1152

1153 1154 1155
	return p;
}

1156 1157
static noinline_for_stack
char *ip6_compressed_string(char *p, const char *addr)
1158
{
1159
	int i, j, range;
1160 1161 1162 1163
	unsigned char zerolength[8];
	int longest = 1;
	int colonpos = -1;
	u16 word;
1164
	u8 hi, lo;
1165
	bool needcolon = false;
1166 1167 1168 1169 1170 1171
	bool useIPv4;
	struct in6_addr in6;

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

	useIPv4 = ipv6_addr_v4mapped(&in6) || ipv6_addr_is_isatap(&in6);
1172 1173 1174 1175 1176 1177 1178 1179 1180 1181 1182

	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++) {
1183
			if (in6.s6_addr16[j] != 0)
1184 1185 1186 1187 1188 1189 1190 1191 1192 1193
				break;
			zerolength[i]++;
		}
	}
	for (i = 0; i < range; i++) {
		if (zerolength[i] > longest) {
			longest = zerolength[i];
			colonpos = i;
		}
	}
1194 1195
	if (longest == 1)		/* don't compress a single 0 */
		colonpos = -1;
1196

1197 1198 1199 1200 1201 1202 1203 1204 1205 1206 1207 1208 1209 1210 1211
	/* 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 */
1212
		word = ntohs(in6.s6_addr16[i]);
1213 1214 1215 1216
		hi = word >> 8;
		lo = word & 0xff;
		if (hi) {
			if (hi > 0x0f)
1217
				p = hex_byte_pack(p, hi);
1218 1219
			else
				*p++ = hex_asc_lo(hi);
1220
			p = hex_byte_pack(p, lo);
1221
		}
1222
		else if (lo > 0x0f)
1223
			p = hex_byte_pack(p, lo);
1224 1225 1226 1227 1228 1229 1230 1231
		else
			*p++ = hex_asc_lo(lo);
		needcolon = true;
	}

	if (useIPv4) {
		if (needcolon)
			*p++ = ':';
1232
		p = ip4_string(p, &in6.s6_addr[12], "I4");
1233 1234
	}
	*p = '\0';
1235

1236 1237 1238
	return p;
}

1239 1240
static noinline_for_stack
char *ip6_string(char *p, const char *addr, const char *fmt)
1241 1242
{
	int i;
1243

1244
	for (i = 0; i < 8; i++) {
1245 1246
		p = hex_byte_pack(p, *addr++);
		p = hex_byte_pack(p, *addr++);
1247
		if (fmt[0] == 'I' && i != 7)
1248 1249 1250
			*p++ = ':';
	}
	*p = '\0';
1251

1252 1253 1254
	return p;
}

1255 1256 1257
static noinline_for_stack
char *ip6_addr_string(char *buf, char *end, const u8 *addr,
		      struct printf_spec spec, const char *fmt)
1258 1259 1260 1261
{
	char ip6_addr[sizeof("xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255")];

	if (fmt[0] == 'I' && fmt[2] == 'c')
1262
		ip6_compressed_string(ip6_addr, addr);
1263
	else
1264
		ip6_string(ip6_addr, addr, fmt);
1265

1266
	return string(buf, end, ip6_addr, spec);
1267 1268
}

1269 1270 1271
static noinline_for_stack
char *ip4_addr_string(char *buf, char *end, const u8 *addr,
		      struct printf_spec spec, const char *fmt)
1272
{
1273
	char ip4_addr[sizeof("255.255.255.255")];
1274

1275
	ip4_string(ip4_addr, addr, fmt);
1276

1277
	return string(buf, end, ip4_addr, spec);
1278 1279
}

1280 1281 1282 1283 1284 1285 1286 1287 1288 1289 1290 1291 1292 1293 1294 1295 1296 1297 1298 1299 1300 1301 1302 1303 1304 1305 1306 1307 1308 1309 1310 1311 1312 1313 1314 1315 1316 1317 1318 1319 1320 1321 1322 1323 1324 1325 1326 1327 1328 1329 1330 1331 1332 1333 1334 1335 1336 1337 1338 1339 1340 1341 1342 1343 1344 1345 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
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);
}

1377 1378 1379 1380 1381 1382 1383 1384 1385 1386 1387 1388 1389 1390 1391 1392 1393 1394 1395 1396 1397 1398 1399 1400 1401 1402 1403 1404 1405 1406 1407 1408 1409 1410 1411 1412 1413 1414 1415 1416 1417 1418 1419 1420 1421 1422 1423 1424 1425 1426
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;

1427 1428 1429 1430 1431 1432
	/*
	 * 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);
1433 1434 1435 1436

	return buf;
}

1437 1438 1439
static noinline_for_stack
char *uuid_string(char *buf, char *end, const u8 *addr,
		  struct printf_spec spec, const char *fmt)
1440
{
1441
	char uuid[UUID_STRING_LEN + 1];
1442 1443
	char *p = uuid;
	int i;
1444
	const u8 *index = uuid_index;
1445 1446 1447 1448 1449 1450
	bool uc = false;

	switch (*(++fmt)) {
	case 'L':
		uc = true;		/* fall-through */
	case 'l':
1451
		index = guid_index;
1452 1453 1454 1455 1456 1457 1458
		break;
	case 'B':
		uc = true;
		break;
	}

	for (i = 0; i < 16; i++) {
1459 1460 1461 1462
		if (uc)
			p = hex_byte_pack_upper(p, addr[index[i]]);
		else
			p = hex_byte_pack(p, addr[index[i]]);
1463 1464 1465 1466 1467 1468 1469 1470 1471 1472 1473 1474 1475 1476 1477
		switch (i) {
		case 3:
		case 5:
		case 7:
		case 9:
			*p++ = '-';
			break;
		}
	}

	*p = 0;

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

1478 1479 1480 1481 1482 1483 1484 1485 1486 1487 1488 1489 1490 1491 1492 1493 1494
int kptr_restrict __read_mostly;

static noinline_for_stack
char *restricted_pointer(char *buf, char *end, const void *ptr,
			 struct printf_spec spec)
{
	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.
		 */
1495 1496 1497
		if (in_irq() || in_serving_softirq() || in_nmi()) {
			if (spec.field_width == -1)
				spec.field_width = 2 * sizeof(ptr);
1498
			return string(buf, end, "pK-error", spec);
1499
		}
1500 1501