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v3.15
 
   1/*
   2 *  linux/lib/vsprintf.c
   3 *
   4 *  Copyright (C) 1991, 1992  Linus Torvalds
   5 */
   6
   7/* vsprintf.c -- Lars Wirzenius & Linus Torvalds. */
   8/*
   9 * Wirzenius wrote this portably, Torvalds fucked it up :-)
  10 */
  11
  12/*
  13 * Fri Jul 13 2001 Crutcher Dunnavant <crutcher+kernel@datastacks.com>
  14 * - changed to provide snprintf and vsnprintf functions
  15 * So Feb  1 16:51:32 CET 2004 Juergen Quade <quade@hsnr.de>
  16 * - scnprintf and vscnprintf
  17 */
  18
  19#include <stdarg.h>
 
 
 
 
  20#include <linux/module.h>	/* for KSYM_SYMBOL_LEN */
  21#include <linux/types.h>
  22#include <linux/string.h>
  23#include <linux/ctype.h>
  24#include <linux/kernel.h>
  25#include <linux/kallsyms.h>
  26#include <linux/math64.h>
  27#include <linux/uaccess.h>
  28#include <linux/ioport.h>
  29#include <linux/dcache.h>
  30#include <linux/cred.h>
 
 
 
 
 
  31#include <net/addrconf.h>
 
 
 
 
 
 
 
 
 
  32
  33#include <asm/page.h>		/* for PAGE_SIZE */
  34#include <asm/sections.h>	/* for dereference_function_descriptor() */
 
  35
 
  36#include "kstrtox.h"
  37
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  38/**
  39 * simple_strtoull - convert a string to an unsigned long long
  40 * @cp: The start of the string
  41 * @endp: A pointer to the end of the parsed string will be placed here
  42 * @base: The number base to use
  43 *
  44 * This function is obsolete. Please use kstrtoull instead.
  45 */
 
  46unsigned long long simple_strtoull(const char *cp, char **endp, unsigned int base)
  47{
  48	unsigned long long result;
  49	unsigned int rv;
  50
  51	cp = _parse_integer_fixup_radix(cp, &base);
  52	rv = _parse_integer(cp, base, &result);
  53	/* FIXME */
  54	cp += (rv & ~KSTRTOX_OVERFLOW);
  55
  56	if (endp)
  57		*endp = (char *)cp;
  58
  59	return result;
  60}
  61EXPORT_SYMBOL(simple_strtoull);
  62
  63/**
  64 * simple_strtoul - convert a string to an unsigned long
  65 * @cp: The start of the string
  66 * @endp: A pointer to the end of the parsed string will be placed here
  67 * @base: The number base to use
  68 *
  69 * This function is obsolete. Please use kstrtoul instead.
  70 */
  71unsigned long simple_strtoul(const char *cp, char **endp, unsigned int base)
  72{
  73	return simple_strtoull(cp, endp, base);
  74}
  75EXPORT_SYMBOL(simple_strtoul);
  76
  77/**
  78 * simple_strtol - convert a string to a signed long
  79 * @cp: The start of the string
  80 * @endp: A pointer to the end of the parsed string will be placed here
  81 * @base: The number base to use
  82 *
  83 * This function is obsolete. Please use kstrtol instead.
  84 */
  85long simple_strtol(const char *cp, char **endp, unsigned int base)
  86{
  87	if (*cp == '-')
  88		return -simple_strtoul(cp + 1, endp, base);
  89
  90	return simple_strtoul(cp, endp, base);
  91}
  92EXPORT_SYMBOL(simple_strtol);
  93
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  94/**
  95 * simple_strtoll - convert a string to a signed long long
  96 * @cp: The start of the string
  97 * @endp: A pointer to the end of the parsed string will be placed here
  98 * @base: The number base to use
  99 *
 100 * This function is obsolete. Please use kstrtoll instead.
 101 */
 102long long simple_strtoll(const char *cp, char **endp, unsigned int base)
 103{
 104	if (*cp == '-')
 105		return -simple_strtoull(cp + 1, endp, base);
 106
 107	return simple_strtoull(cp, endp, base);
 108}
 109EXPORT_SYMBOL(simple_strtoll);
 110
 111static noinline_for_stack
 112int skip_atoi(const char **s)
 113{
 114	int i = 0;
 115
 116	while (isdigit(**s))
 117		i = i*10 + *((*s)++) - '0';
 
 118
 119	return i;
 120}
 121
 122/* Decimal conversion is by far the most typical, and is used
 123 * for /proc and /sys data. This directly impacts e.g. top performance
 124 * with many processes running. We optimize it for speed
 125 * using ideas described at <http://www.cs.uiowa.edu/~jones/bcd/divide.html>
 126 * (with permission from the author, Douglas W. Jones).
 127 */
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 128
 129#if BITS_PER_LONG != 32 || BITS_PER_LONG_LONG != 64
 130/* Formats correctly any integer in [0, 999999999] */
 
 
 
 
 131static noinline_for_stack
 132char *put_dec_full9(char *buf, unsigned q)
 133{
 134	unsigned r;
 135
 136	/*
 137	 * Possible ways to approx. divide by 10
 138	 * (x * 0x1999999a) >> 32 x < 1073741829 (multiply must be 64-bit)
 139	 * (x * 0xcccd) >> 19     x <      81920 (x < 262149 when 64-bit mul)
 140	 * (x * 0x6667) >> 18     x <      43699
 141	 * (x * 0x3334) >> 17     x <      16389
 142	 * (x * 0x199a) >> 16     x <      16389
 143	 * (x * 0x0ccd) >> 15     x <      16389
 144	 * (x * 0x0667) >> 14     x <       2739
 145	 * (x * 0x0334) >> 13     x <       1029
 146	 * (x * 0x019a) >> 12     x <       1029
 147	 * (x * 0x00cd) >> 11     x <       1029 shorter code than * 0x67 (on i386)
 148	 * (x * 0x0067) >> 10     x <        179
 149	 * (x * 0x0034) >>  9     x <         69 same
 150	 * (x * 0x001a) >>  8     x <         69 same
 151	 * (x * 0x000d) >>  7     x <         69 same, shortest code (on i386)
 152	 * (x * 0x0007) >>  6     x <         19
 153	 * See <http://www.cs.uiowa.edu/~jones/bcd/divide.html>
 154	 */
 155	r      = (q * (uint64_t)0x1999999a) >> 32;
 156	*buf++ = (q - 10 * r) + '0'; /* 1 */
 157	q      = (r * (uint64_t)0x1999999a) >> 32;
 158	*buf++ = (r - 10 * q) + '0'; /* 2 */
 159	r      = (q * (uint64_t)0x1999999a) >> 32;
 160	*buf++ = (q - 10 * r) + '0'; /* 3 */
 161	q      = (r * (uint64_t)0x1999999a) >> 32;
 162	*buf++ = (r - 10 * q) + '0'; /* 4 */
 163	r      = (q * (uint64_t)0x1999999a) >> 32;
 164	*buf++ = (q - 10 * r) + '0'; /* 5 */
 165	/* Now value is under 10000, can avoid 64-bit multiply */
 166	q      = (r * 0x199a) >> 16;
 167	*buf++ = (r - 10 * q)  + '0'; /* 6 */
 168	r      = (q * 0xcd) >> 11;
 169	*buf++ = (q - 10 * r)  + '0'; /* 7 */
 170	q      = (r * 0xcd) >> 11;
 171	*buf++ = (r - 10 * q) + '0'; /* 8 */
 172	*buf++ = q + '0'; /* 9 */
 173	return buf;
 174}
 175#endif
 176
 177/* Similar to above but do not pad with zeros.
 178 * Code can be easily arranged to print 9 digits too, but our callers
 179 * always call put_dec_full9() instead when the number has 9 decimal digits.
 180 */
 181static noinline_for_stack
 182char *put_dec_trunc8(char *buf, unsigned r)
 183{
 184	unsigned q;
 185
 186	/* Copy of previous function's body with added early returns */
 187	while (r >= 10000) {
 188		q = r + '0';
 189		r  = (r * (uint64_t)0x1999999a) >> 32;
 190		*buf++ = q - 10*r;
 191	}
 192
 193	q      = (r * 0x199a) >> 16;	/* r <= 9999 */
 194	*buf++ = (r - 10 * q)  + '0';
 195	if (q == 0)
 196		return buf;
 197	r      = (q * 0xcd) >> 11;	/* q <= 999 */
 198	*buf++ = (q - 10 * r)  + '0';
 199	if (r == 0)
 200		return buf;
 201	q      = (r * 0xcd) >> 11;	/* r <= 99 */
 202	*buf++ = (r - 10 * q) + '0';
 203	if (q == 0)
 204		return buf;
 205	*buf++ = q + '0';		 /* q <= 9 */
 206	return buf;
 207}
 208
 209/* There are two algorithms to print larger numbers.
 210 * One is generic: divide by 1000000000 and repeatedly print
 211 * groups of (up to) 9 digits. It's conceptually simple,
 212 * but requires a (unsigned long long) / 1000000000 division.
 213 *
 214 * Second algorithm splits 64-bit unsigned long long into 16-bit chunks,
 215 * manipulates them cleverly and generates groups of 4 decimal digits.
 216 * It so happens that it does NOT require long long division.
 217 *
 218 * If long is > 32 bits, division of 64-bit values is relatively easy,
 219 * and we will use the first algorithm.
 220 * If long long is > 64 bits (strange architecture with VERY large long long),
 221 * second algorithm can't be used, and we again use the first one.
 222 *
 223 * Else (if long is 32 bits and long long is 64 bits) we use second one.
 224 */
 225
 226#if BITS_PER_LONG != 32 || BITS_PER_LONG_LONG != 64
 227
 228/* First algorithm: generic */
 229
 230static
 231char *put_dec(char *buf, unsigned long long n)
 232{
 233	if (n >= 100*1000*1000) {
 234		while (n >= 1000*1000*1000)
 235			buf = put_dec_full9(buf, do_div(n, 1000*1000*1000));
 236		if (n >= 100*1000*1000)
 237			return put_dec_full9(buf, n);
 238	}
 239	return put_dec_trunc8(buf, n);
 240}
 241
 242#else
 243
 244/* Second algorithm: valid only for 64-bit long longs */
 245
 246/* See comment in put_dec_full9 for choice of constants */
 247static noinline_for_stack
 248void put_dec_full4(char *buf, unsigned q)
 249{
 250	unsigned r;
 251	r      = (q * 0xccd) >> 15;
 252	buf[0] = (q - 10 * r) + '0';
 253	q      = (r * 0xcd) >> 11;
 254	buf[1] = (r - 10 * q)  + '0';
 255	r      = (q * 0xcd) >> 11;
 256	buf[2] = (q - 10 * r)  + '0';
 257	buf[3] = r + '0';
 258}
 259
 260/*
 261 * Call put_dec_full4 on x % 10000, return x / 10000.
 262 * The approximation x/10000 == (x * 0x346DC5D7) >> 43
 263 * holds for all x < 1,128,869,999.  The largest value this
 264 * helper will ever be asked to convert is 1,125,520,955.
 265 * (d1 in the put_dec code, assuming n is all-ones).
 266 */
 267static
 268unsigned put_dec_helper4(char *buf, unsigned x)
 269{
 270        uint32_t q = (x * (uint64_t)0x346DC5D7) >> 43;
 271
 272        put_dec_full4(buf, x - q * 10000);
 273        return q;
 274}
 275
 276/* Based on code by Douglas W. Jones found at
 277 * <http://www.cs.uiowa.edu/~jones/bcd/decimal.html#sixtyfour>
 278 * (with permission from the author).
 279 * Performs no 64-bit division and hence should be fast on 32-bit machines.
 280 */
 281static
 282char *put_dec(char *buf, unsigned long long n)
 283{
 284	uint32_t d3, d2, d1, q, h;
 285
 286	if (n < 100*1000*1000)
 287		return put_dec_trunc8(buf, n);
 288
 289	d1  = ((uint32_t)n >> 16); /* implicit "& 0xffff" */
 290	h   = (n >> 32);
 291	d2  = (h      ) & 0xffff;
 292	d3  = (h >> 16); /* implicit "& 0xffff" */
 293
 
 
 294	q   = 656 * d3 + 7296 * d2 + 5536 * d1 + ((uint32_t)n & 0xffff);
 295	q = put_dec_helper4(buf, q);
 296
 297	q += 7671 * d3 + 9496 * d2 + 6 * d1;
 298	q = put_dec_helper4(buf+4, q);
 299
 300	q += 4749 * d3 + 42 * d2;
 301	q = put_dec_helper4(buf+8, q);
 302
 303	q += 281 * d3;
 304	buf += 12;
 305	if (q)
 306		buf = put_dec_trunc8(buf, q);
 307	else while (buf[-1] == '0')
 308		--buf;
 309
 310	return buf;
 311}
 312
 313#endif
 314
 315/*
 316 * Convert passed number to decimal string.
 317 * Returns the length of string.  On buffer overflow, returns 0.
 318 *
 319 * If speed is not important, use snprintf(). It's easy to read the code.
 320 */
 321int num_to_str(char *buf, int size, unsigned long long num)
 322{
 323	char tmp[sizeof(num) * 3];
 
 324	int idx, len;
 325
 326	/* put_dec() may work incorrectly for num = 0 (generate "", not "0") */
 327	if (num <= 9) {
 328		tmp[0] = '0' + num;
 329		len = 1;
 330	} else {
 331		len = put_dec(tmp, num) - tmp;
 332	}
 333
 334	if (len > size)
 335		return 0;
 
 
 
 
 
 
 
 
 
 336	for (idx = 0; idx < len; ++idx)
 337		buf[idx] = tmp[len - idx - 1];
 338	return len;
 
 339}
 340
 341#define ZEROPAD	1		/* pad with zero */
 342#define SIGN	2		/* unsigned/signed long */
 343#define PLUS	4		/* show plus */
 344#define SPACE	8		/* space if plus */
 345#define LEFT	16		/* left justified */
 346#define SMALL	32		/* use lowercase in hex (must be 32 == 0x20) */
 347#define SPECIAL	64		/* prefix hex with "0x", octal with "0" */
 348
 
 
 
 
 349enum format_type {
 350	FORMAT_TYPE_NONE, /* Just a string part */
 351	FORMAT_TYPE_WIDTH,
 352	FORMAT_TYPE_PRECISION,
 353	FORMAT_TYPE_CHAR,
 354	FORMAT_TYPE_STR,
 355	FORMAT_TYPE_PTR,
 356	FORMAT_TYPE_PERCENT_CHAR,
 357	FORMAT_TYPE_INVALID,
 358	FORMAT_TYPE_LONG_LONG,
 359	FORMAT_TYPE_ULONG,
 360	FORMAT_TYPE_LONG,
 361	FORMAT_TYPE_UBYTE,
 362	FORMAT_TYPE_BYTE,
 363	FORMAT_TYPE_USHORT,
 364	FORMAT_TYPE_SHORT,
 365	FORMAT_TYPE_UINT,
 366	FORMAT_TYPE_INT,
 367	FORMAT_TYPE_SIZE_T,
 368	FORMAT_TYPE_PTRDIFF
 369};
 370
 371struct printf_spec {
 372	u8	type;		/* format_type enum */
 373	u8	flags;		/* flags to number() */
 374	u8	base;		/* number base, 8, 10 or 16 only */
 375	u8	qualifier;	/* number qualifier, one of 'hHlLtzZ' */
 376	s16	field_width;	/* width of output field */
 377	s16	precision;	/* # of digits/chars */
 378};
 
 
 
 379
 380static noinline_for_stack
 381char *number(char *buf, char *end, unsigned long long num,
 382	     struct printf_spec spec)
 383{
 384	/* we are called with base 8, 10 or 16, only, thus don't need "G..."  */
 385	static const char digits[16] = "0123456789ABCDEF"; /* "GHIJKLMNOPQRSTUVWXYZ"; */
 386
 387	char tmp[66];
 388	char sign;
 389	char locase;
 390	int need_pfx = ((spec.flags & SPECIAL) && spec.base != 10);
 391	int i;
 392	bool is_zero = num == 0LL;
 
 
 393
 394	/* locase = 0 or 0x20. ORing digits or letters with 'locase'
 395	 * produces same digits or (maybe lowercased) letters */
 396	locase = (spec.flags & SMALL);
 397	if (spec.flags & LEFT)
 398		spec.flags &= ~ZEROPAD;
 399	sign = 0;
 400	if (spec.flags & SIGN) {
 401		if ((signed long long)num < 0) {
 402			sign = '-';
 403			num = -(signed long long)num;
 404			spec.field_width--;
 405		} else if (spec.flags & PLUS) {
 406			sign = '+';
 407			spec.field_width--;
 408		} else if (spec.flags & SPACE) {
 409			sign = ' ';
 410			spec.field_width--;
 411		}
 412	}
 413	if (need_pfx) {
 414		if (spec.base == 16)
 415			spec.field_width -= 2;
 416		else if (!is_zero)
 417			spec.field_width--;
 418	}
 419
 420	/* generate full string in tmp[], in reverse order */
 421	i = 0;
 422	if (num < spec.base)
 423		tmp[i++] = digits[num] | locase;
 424	/* Generic code, for any base:
 425	else do {
 426		tmp[i++] = (digits[do_div(num,base)] | locase);
 427	} while (num != 0);
 428	*/
 429	else if (spec.base != 10) { /* 8 or 16 */
 430		int mask = spec.base - 1;
 431		int shift = 3;
 432
 433		if (spec.base == 16)
 434			shift = 4;
 435		do {
 436			tmp[i++] = (digits[((unsigned char)num) & mask] | locase);
 437			num >>= shift;
 438		} while (num);
 439	} else { /* base 10 */
 440		i = put_dec(tmp, num) - tmp;
 441	}
 442
 443	/* printing 100 using %2d gives "100", not "00" */
 444	if (i > spec.precision)
 445		spec.precision = i;
 446	/* leading space padding */
 447	spec.field_width -= spec.precision;
 448	if (!(spec.flags & (ZEROPAD+LEFT))) {
 449		while (--spec.field_width >= 0) {
 450			if (buf < end)
 451				*buf = ' ';
 452			++buf;
 453		}
 454	}
 455	/* sign */
 456	if (sign) {
 457		if (buf < end)
 458			*buf = sign;
 459		++buf;
 460	}
 461	/* "0x" / "0" prefix */
 462	if (need_pfx) {
 463		if (spec.base == 16 || !is_zero) {
 464			if (buf < end)
 465				*buf = '0';
 466			++buf;
 467		}
 468		if (spec.base == 16) {
 469			if (buf < end)
 470				*buf = ('X' | locase);
 471			++buf;
 472		}
 473	}
 474	/* zero or space padding */
 475	if (!(spec.flags & LEFT)) {
 476		char c = (spec.flags & ZEROPAD) ? '0' : ' ';
 477		while (--spec.field_width >= 0) {
 
 478			if (buf < end)
 479				*buf = c;
 480			++buf;
 481		}
 482	}
 483	/* hmm even more zero padding? */
 484	while (i <= --spec.precision) {
 485		if (buf < end)
 486			*buf = '0';
 487		++buf;
 488	}
 489	/* actual digits of result */
 490	while (--i >= 0) {
 491		if (buf < end)
 492			*buf = tmp[i];
 493		++buf;
 494	}
 495	/* trailing space padding */
 496	while (--spec.field_width >= 0) {
 497		if (buf < end)
 498			*buf = ' ';
 499		++buf;
 500	}
 501
 502	return buf;
 503}
 504
 505static noinline_for_stack
 506char *string(char *buf, char *end, const char *s, struct printf_spec spec)
 507{
 508	int len, i;
 509
 510	if ((unsigned long)s < PAGE_SIZE)
 511		s = "(null)";
 512
 513	len = strnlen(s, spec.precision);
 514
 515	if (!(spec.flags & LEFT)) {
 516		while (len < spec.field_width--) {
 517			if (buf < end)
 518				*buf = ' ';
 519			++buf;
 520		}
 521	}
 522	for (i = 0; i < len; ++i) {
 523		if (buf < end)
 524			*buf = *s;
 525		++buf; ++s;
 526	}
 527	while (len < spec.field_width--) {
 528		if (buf < end)
 529			*buf = ' ';
 530		++buf;
 531	}
 532
 533	return buf;
 534}
 535
 536static void widen(char *buf, char *end, unsigned len, unsigned spaces)
 537{
 538	size_t size;
 539	if (buf >= end)	/* nowhere to put anything */
 540		return;
 541	size = end - buf;
 542	if (size <= spaces) {
 543		memset(buf, ' ', size);
 544		return;
 545	}
 546	if (len) {
 547		if (len > size - spaces)
 548			len = size - spaces;
 549		memmove(buf + spaces, buf, len);
 550	}
 551	memset(buf, ' ', spaces);
 552}
 553
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 554static noinline_for_stack
 555char *dentry_name(char *buf, char *end, const struct dentry *d, struct printf_spec spec,
 556		  const char *fmt)
 557{
 558	const char *array[4], *s;
 559	const struct dentry *p;
 560	int depth;
 561	int i, n;
 562
 563	switch (fmt[1]) {
 564		case '2': case '3': case '4':
 565			depth = fmt[1] - '0';
 566			break;
 567		default:
 568			depth = 1;
 569	}
 570
 571	rcu_read_lock();
 572	for (i = 0; i < depth; i++, d = p) {
 573		p = ACCESS_ONCE(d->d_parent);
 574		array[i] = ACCESS_ONCE(d->d_name.name);
 
 
 
 
 
 575		if (p == d) {
 576			if (i)
 577				array[i] = "";
 578			i++;
 579			break;
 580		}
 581	}
 582	s = array[--i];
 583	for (n = 0; n != spec.precision; n++, buf++) {
 584		char c = *s++;
 585		if (!c) {
 586			if (!i)
 587				break;
 588			c = '/';
 589			s = array[--i];
 590		}
 591		if (buf < end)
 592			*buf = c;
 593	}
 594	rcu_read_unlock();
 595	if (n < spec.field_width) {
 596		/* we want to pad the sucker */
 597		unsigned spaces = spec.field_width - n;
 598		if (!(spec.flags & LEFT)) {
 599			widen(buf - n, end, n, spaces);
 600			return buf + spaces;
 601		}
 602		while (spaces--) {
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 603			if (buf < end)
 604				*buf = ' ';
 605			++buf;
 606		}
 
 607	}
 608	return buf;
 609}
 
 610
 611static noinline_for_stack
 612char *symbol_string(char *buf, char *end, void *ptr,
 613		    struct printf_spec spec, const char *fmt)
 614{
 615	unsigned long value;
 616#ifdef CONFIG_KALLSYMS
 617	char sym[KSYM_SYMBOL_LEN];
 618#endif
 619
 620	if (fmt[1] == 'R')
 621		ptr = __builtin_extract_return_addr(ptr);
 622	value = (unsigned long)ptr;
 623
 624#ifdef CONFIG_KALLSYMS
 625	if (*fmt == 'B')
 
 
 626		sprint_backtrace(sym, value);
 627	else if (*fmt != 'f' && *fmt != 's')
 
 
 628		sprint_symbol(sym, value);
 629	else
 630		sprint_symbol_no_offset(sym, value);
 631
 632	return string(buf, end, sym, spec);
 633#else
 634	spec.field_width = 2 * sizeof(void *);
 635	spec.flags |= SPECIAL | SMALL | ZEROPAD;
 636	spec.base = 16;
 637
 638	return number(buf, end, value, spec);
 639#endif
 640}
 641
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 642static noinline_for_stack
 643char *resource_string(char *buf, char *end, struct resource *res,
 644		      struct printf_spec spec, const char *fmt)
 645{
 646#ifndef IO_RSRC_PRINTK_SIZE
 647#define IO_RSRC_PRINTK_SIZE	6
 648#endif
 649
 650#ifndef MEM_RSRC_PRINTK_SIZE
 651#define MEM_RSRC_PRINTK_SIZE	10
 652#endif
 653	static const struct printf_spec io_spec = {
 654		.base = 16,
 655		.field_width = IO_RSRC_PRINTK_SIZE,
 656		.precision = -1,
 657		.flags = SPECIAL | SMALL | ZEROPAD,
 658	};
 659	static const struct printf_spec mem_spec = {
 660		.base = 16,
 661		.field_width = MEM_RSRC_PRINTK_SIZE,
 662		.precision = -1,
 663		.flags = SPECIAL | SMALL | ZEROPAD,
 664	};
 665	static const struct printf_spec bus_spec = {
 666		.base = 16,
 667		.field_width = 2,
 668		.precision = -1,
 669		.flags = SMALL | ZEROPAD,
 670	};
 671	static const struct printf_spec dec_spec = {
 672		.base = 10,
 673		.precision = -1,
 674		.flags = 0,
 675	};
 676	static const struct printf_spec str_spec = {
 677		.field_width = -1,
 678		.precision = 10,
 679		.flags = LEFT,
 680	};
 681	static const struct printf_spec flag_spec = {
 682		.base = 16,
 683		.precision = -1,
 684		.flags = SPECIAL | SMALL,
 685	};
 686
 687	/* 32-bit res (sizeof==4): 10 chars in dec, 10 in hex ("0x" + 8)
 688	 * 64-bit res (sizeof==8): 20 chars in dec, 18 in hex ("0x" + 16) */
 689#define RSRC_BUF_SIZE		((2 * sizeof(resource_size_t)) + 4)
 690#define FLAG_BUF_SIZE		(2 * sizeof(res->flags))
 691#define DECODED_BUF_SIZE	sizeof("[mem - 64bit pref window disabled]")
 692#define RAW_BUF_SIZE		sizeof("[mem - flags 0x]")
 693	char sym[max(2*RSRC_BUF_SIZE + DECODED_BUF_SIZE,
 694		     2*RSRC_BUF_SIZE + FLAG_BUF_SIZE + RAW_BUF_SIZE)];
 695
 696	char *p = sym, *pend = sym + sizeof(sym);
 697	int decode = (fmt[0] == 'R') ? 1 : 0;
 698	const struct printf_spec *specp;
 699
 
 
 
 700	*p++ = '[';
 701	if (res->flags & IORESOURCE_IO) {
 702		p = string(p, pend, "io  ", str_spec);
 703		specp = &io_spec;
 704	} else if (res->flags & IORESOURCE_MEM) {
 705		p = string(p, pend, "mem ", str_spec);
 706		specp = &mem_spec;
 707	} else if (res->flags & IORESOURCE_IRQ) {
 708		p = string(p, pend, "irq ", str_spec);
 709		specp = &dec_spec;
 710	} else if (res->flags & IORESOURCE_DMA) {
 711		p = string(p, pend, "dma ", str_spec);
 712		specp = &dec_spec;
 713	} else if (res->flags & IORESOURCE_BUS) {
 714		p = string(p, pend, "bus ", str_spec);
 715		specp = &bus_spec;
 716	} else {
 717		p = string(p, pend, "??? ", str_spec);
 718		specp = &mem_spec;
 719		decode = 0;
 720	}
 721	if (decode && res->flags & IORESOURCE_UNSET) {
 722		p = string(p, pend, "size ", str_spec);
 723		p = number(p, pend, resource_size(res), *specp);
 724	} else {
 725		p = number(p, pend, res->start, *specp);
 726		if (res->start != res->end) {
 727			*p++ = '-';
 728			p = number(p, pend, res->end, *specp);
 729		}
 730	}
 731	if (decode) {
 732		if (res->flags & IORESOURCE_MEM_64)
 733			p = string(p, pend, " 64bit", str_spec);
 734		if (res->flags & IORESOURCE_PREFETCH)
 735			p = string(p, pend, " pref", str_spec);
 736		if (res->flags & IORESOURCE_WINDOW)
 737			p = string(p, pend, " window", str_spec);
 738		if (res->flags & IORESOURCE_DISABLED)
 739			p = string(p, pend, " disabled", str_spec);
 740	} else {
 741		p = string(p, pend, " flags ", str_spec);
 742		p = number(p, pend, res->flags, flag_spec);
 743	}
 744	*p++ = ']';
 745	*p = '\0';
 746
 747	return string(buf, end, sym, spec);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 748}
 749
 750static noinline_for_stack
 751char *hex_string(char *buf, char *end, u8 *addr, struct printf_spec spec,
 752		 const char *fmt)
 753{
 754	int i, len = 1;		/* if we pass '%ph[CDN]', field width remains
 755				   negative value, fallback to the default */
 756	char separator;
 757
 758	if (spec.field_width == 0)
 759		/* nothing to print */
 760		return buf;
 761
 762	if (ZERO_OR_NULL_PTR(addr))
 763		/* NULL pointer */
 764		return string(buf, end, NULL, spec);
 765
 766	switch (fmt[1]) {
 767	case 'C':
 768		separator = ':';
 769		break;
 770	case 'D':
 771		separator = '-';
 772		break;
 773	case 'N':
 774		separator = 0;
 775		break;
 776	default:
 777		separator = ' ';
 778		break;
 779	}
 780
 781	if (spec.field_width > 0)
 782		len = min_t(int, spec.field_width, 64);
 783
 784	for (i = 0; i < len && buf < end - 1; i++) {
 785		buf = hex_byte_pack(buf, addr[i]);
 
 
 
 
 
 786
 787		if (buf < end && separator && i != len - 1)
 788			*buf++ = separator;
 
 
 
 789	}
 790
 791	return buf;
 792}
 793
 794static noinline_for_stack
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 795char *mac_address_string(char *buf, char *end, u8 *addr,
 796			 struct printf_spec spec, const char *fmt)
 797{
 798	char mac_addr[sizeof("xx:xx:xx:xx:xx:xx")];
 799	char *p = mac_addr;
 800	int i;
 801	char separator;
 802	bool reversed = false;
 803
 
 
 
 804	switch (fmt[1]) {
 805	case 'F':
 806		separator = '-';
 807		break;
 808
 809	case 'R':
 810		reversed = true;
 811		/* fall through */
 812
 813	default:
 814		separator = ':';
 815		break;
 816	}
 817
 818	for (i = 0; i < 6; i++) {
 819		if (reversed)
 820			p = hex_byte_pack(p, addr[5 - i]);
 821		else
 822			p = hex_byte_pack(p, addr[i]);
 823
 824		if (fmt[0] == 'M' && i != 5)
 825			*p++ = separator;
 826	}
 827	*p = '\0';
 828
 829	return string(buf, end, mac_addr, spec);
 830}
 831
 832static noinline_for_stack
 833char *ip4_string(char *p, const u8 *addr, const char *fmt)
 834{
 835	int i;
 836	bool leading_zeros = (fmt[0] == 'i');
 837	int index;
 838	int step;
 839
 840	switch (fmt[2]) {
 841	case 'h':
 842#ifdef __BIG_ENDIAN
 843		index = 0;
 844		step = 1;
 845#else
 846		index = 3;
 847		step = -1;
 848#endif
 849		break;
 850	case 'l':
 851		index = 3;
 852		step = -1;
 853		break;
 854	case 'n':
 855	case 'b':
 856	default:
 857		index = 0;
 858		step = 1;
 859		break;
 860	}
 861	for (i = 0; i < 4; i++) {
 862		char temp[3];	/* hold each IP quad in reverse order */
 863		int digits = put_dec_trunc8(temp, addr[index]) - temp;
 864		if (leading_zeros) {
 865			if (digits < 3)
 866				*p++ = '0';
 867			if (digits < 2)
 868				*p++ = '0';
 869		}
 870		/* reverse the digits in the quad */
 871		while (digits--)
 872			*p++ = temp[digits];
 873		if (i < 3)
 874			*p++ = '.';
 875		index += step;
 876	}
 877	*p = '\0';
 878
 879	return p;
 880}
 881
 882static noinline_for_stack
 883char *ip6_compressed_string(char *p, const char *addr)
 884{
 885	int i, j, range;
 886	unsigned char zerolength[8];
 887	int longest = 1;
 888	int colonpos = -1;
 889	u16 word;
 890	u8 hi, lo;
 891	bool needcolon = false;
 892	bool useIPv4;
 893	struct in6_addr in6;
 894
 895	memcpy(&in6, addr, sizeof(struct in6_addr));
 896
 897	useIPv4 = ipv6_addr_v4mapped(&in6) || ipv6_addr_is_isatap(&in6);
 898
 899	memset(zerolength, 0, sizeof(zerolength));
 900
 901	if (useIPv4)
 902		range = 6;
 903	else
 904		range = 8;
 905
 906	/* find position of longest 0 run */
 907	for (i = 0; i < range; i++) {
 908		for (j = i; j < range; j++) {
 909			if (in6.s6_addr16[j] != 0)
 910				break;
 911			zerolength[i]++;
 912		}
 913	}
 914	for (i = 0; i < range; i++) {
 915		if (zerolength[i] > longest) {
 916			longest = zerolength[i];
 917			colonpos = i;
 918		}
 919	}
 920	if (longest == 1)		/* don't compress a single 0 */
 921		colonpos = -1;
 922
 923	/* emit address */
 924	for (i = 0; i < range; i++) {
 925		if (i == colonpos) {
 926			if (needcolon || i == 0)
 927				*p++ = ':';
 928			*p++ = ':';
 929			needcolon = false;
 930			i += longest - 1;
 931			continue;
 932		}
 933		if (needcolon) {
 934			*p++ = ':';
 935			needcolon = false;
 936		}
 937		/* hex u16 without leading 0s */
 938		word = ntohs(in6.s6_addr16[i]);
 939		hi = word >> 8;
 940		lo = word & 0xff;
 941		if (hi) {
 942			if (hi > 0x0f)
 943				p = hex_byte_pack(p, hi);
 944			else
 945				*p++ = hex_asc_lo(hi);
 946			p = hex_byte_pack(p, lo);
 947		}
 948		else if (lo > 0x0f)
 949			p = hex_byte_pack(p, lo);
 950		else
 951			*p++ = hex_asc_lo(lo);
 952		needcolon = true;
 953	}
 954
 955	if (useIPv4) {
 956		if (needcolon)
 957			*p++ = ':';
 958		p = ip4_string(p, &in6.s6_addr[12], "I4");
 959	}
 960	*p = '\0';
 961
 962	return p;
 963}
 964
 965static noinline_for_stack
 966char *ip6_string(char *p, const char *addr, const char *fmt)
 967{
 968	int i;
 969
 970	for (i = 0; i < 8; i++) {
 971		p = hex_byte_pack(p, *addr++);
 972		p = hex_byte_pack(p, *addr++);
 973		if (fmt[0] == 'I' && i != 7)
 974			*p++ = ':';
 975	}
 976	*p = '\0';
 977
 978	return p;
 979}
 980
 981static noinline_for_stack
 982char *ip6_addr_string(char *buf, char *end, const u8 *addr,
 983		      struct printf_spec spec, const char *fmt)
 984{
 985	char ip6_addr[sizeof("xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255")];
 986
 987	if (fmt[0] == 'I' && fmt[2] == 'c')
 988		ip6_compressed_string(ip6_addr, addr);
 989	else
 990		ip6_string(ip6_addr, addr, fmt);
 991
 992	return string(buf, end, ip6_addr, spec);
 993}
 994
 995static noinline_for_stack
 996char *ip4_addr_string(char *buf, char *end, const u8 *addr,
 997		      struct printf_spec spec, const char *fmt)
 998{
 999	char ip4_addr[sizeof("255.255.255.255")];
1000
1001	ip4_string(ip4_addr, addr, fmt);
1002
1003	return string(buf, end, ip4_addr, spec);
1004}
1005
1006static noinline_for_stack
1007char *ip6_addr_string_sa(char *buf, char *end, const struct sockaddr_in6 *sa,
1008			 struct printf_spec spec, const char *fmt)
1009{
1010	bool have_p = false, have_s = false, have_f = false, have_c = false;
1011	char ip6_addr[sizeof("[xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255]") +
1012		      sizeof(":12345") + sizeof("/123456789") +
1013		      sizeof("%1234567890")];
1014	char *p = ip6_addr, *pend = ip6_addr + sizeof(ip6_addr);
1015	const u8 *addr = (const u8 *) &sa->sin6_addr;
1016	char fmt6[2] = { fmt[0], '6' };
1017	u8 off = 0;
1018
1019	fmt++;
1020	while (isalpha(*++fmt)) {
1021		switch (*fmt) {
1022		case 'p':
1023			have_p = true;
1024			break;
1025		case 'f':
1026			have_f = true;
1027			break;
1028		case 's':
1029			have_s = true;
1030			break;
1031		case 'c':
1032			have_c = true;
1033			break;
1034		}
1035	}
1036
1037	if (have_p || have_s || have_f) {
1038		*p = '[';
1039		off = 1;
1040	}
1041
1042	if (fmt6[0] == 'I' && have_c)
1043		p = ip6_compressed_string(ip6_addr + off, addr);
1044	else
1045		p = ip6_string(ip6_addr + off, addr, fmt6);
1046
1047	if (have_p || have_s || have_f)
1048		*p++ = ']';
1049
1050	if (have_p) {
1051		*p++ = ':';
1052		p = number(p, pend, ntohs(sa->sin6_port), spec);
1053	}
1054	if (have_f) {
1055		*p++ = '/';
1056		p = number(p, pend, ntohl(sa->sin6_flowinfo &
1057					  IPV6_FLOWINFO_MASK), spec);
1058	}
1059	if (have_s) {
1060		*p++ = '%';
1061		p = number(p, pend, sa->sin6_scope_id, spec);
1062	}
1063	*p = '\0';
1064
1065	return string(buf, end, ip6_addr, spec);
1066}
1067
1068static noinline_for_stack
1069char *ip4_addr_string_sa(char *buf, char *end, const struct sockaddr_in *sa,
1070			 struct printf_spec spec, const char *fmt)
1071{
1072	bool have_p = false;
1073	char *p, ip4_addr[sizeof("255.255.255.255") + sizeof(":12345")];
1074	char *pend = ip4_addr + sizeof(ip4_addr);
1075	const u8 *addr = (const u8 *) &sa->sin_addr.s_addr;
1076	char fmt4[3] = { fmt[0], '4', 0 };
1077
1078	fmt++;
1079	while (isalpha(*++fmt)) {
1080		switch (*fmt) {
1081		case 'p':
1082			have_p = true;
1083			break;
1084		case 'h':
1085		case 'l':
1086		case 'n':
1087		case 'b':
1088			fmt4[2] = *fmt;
1089			break;
1090		}
1091	}
1092
1093	p = ip4_string(ip4_addr, addr, fmt4);
1094	if (have_p) {
1095		*p++ = ':';
1096		p = number(p, pend, ntohs(sa->sin_port), spec);
1097	}
1098	*p = '\0';
1099
1100	return string(buf, end, ip4_addr, spec);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1101}
1102
1103static noinline_for_stack
1104char *uuid_string(char *buf, char *end, const u8 *addr,
1105		  struct printf_spec spec, const char *fmt)
1106{
1107	char uuid[sizeof("xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx")];
1108	char *p = uuid;
1109	int i;
1110	static const u8 be[16] = {0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15};
1111	static const u8 le[16] = {3,2,1,0,5,4,7,6,8,9,10,11,12,13,14,15};
1112	const u8 *index = be;
1113	bool uc = false;
1114
 
 
 
1115	switch (*(++fmt)) {
1116	case 'L':
1117		uc = true;		/* fall-through */
 
1118	case 'l':
1119		index = le;
1120		break;
1121	case 'B':
1122		uc = true;
1123		break;
1124	}
1125
1126	for (i = 0; i < 16; i++) {
1127		p = hex_byte_pack(p, addr[index[i]]);
 
 
 
1128		switch (i) {
1129		case 3:
1130		case 5:
1131		case 7:
1132		case 9:
1133			*p++ = '-';
1134			break;
1135		}
1136	}
1137
1138	*p = 0;
1139
1140	if (uc) {
1141		p = uuid;
1142		do {
1143			*p = toupper(*p);
1144		} while (*(++p));
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1145	}
1146
1147	return string(buf, end, uuid, spec);
1148}
1149
1150static
1151char *netdev_feature_string(char *buf, char *end, const u8 *addr,
1152		      struct printf_spec spec)
1153{
1154	spec.flags |= SPECIAL | SMALL | ZEROPAD;
1155	if (spec.field_width == -1)
1156		spec.field_width = 2 + 2 * sizeof(netdev_features_t);
1157	spec.base = 16;
1158
1159	return number(buf, end, *(const netdev_features_t *)addr, spec);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1160}
1161
1162static noinline_for_stack
1163char *address_val(char *buf, char *end, const void *addr,
1164		  struct printf_spec spec, const char *fmt)
1165{
1166	unsigned long long num;
 
1167
1168	spec.flags |= SPECIAL | SMALL | ZEROPAD;
1169	spec.base = 16;
1170
1171	switch (fmt[1]) {
1172	case 'd':
1173		num = *(const dma_addr_t *)addr;
1174		spec.field_width = sizeof(dma_addr_t) * 2 + 2;
1175		break;
1176	case 'p':
1177	default:
1178		num = *(const phys_addr_t *)addr;
1179		spec.field_width = sizeof(phys_addr_t) * 2 + 2;
1180		break;
1181	}
1182
1183	return number(buf, end, num, spec);
1184}
1185
1186int kptr_restrict __read_mostly;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1187
1188/*
1189 * Show a '%p' thing.  A kernel extension is that the '%p' is followed
1190 * by an extra set of alphanumeric characters that are extended format
1191 * specifiers.
1192 *
 
 
 
1193 * Right now we handle:
1194 *
1195 * - 'F' For symbolic function descriptor pointers with offset
1196 * - 'f' For simple symbolic function names without offset
1197 * - 'S' For symbolic direct pointers with offset
1198 * - 's' For symbolic direct pointers without offset
1199 * - '[FfSs]R' as above with __builtin_extract_return_addr() translation
 
1200 * - 'B' For backtraced symbolic direct pointers with offset
 
1201 * - 'R' For decoded struct resource, e.g., [mem 0x0-0x1f 64bit pref]
1202 * - 'r' For raw struct resource, e.g., [mem 0x0-0x1f flags 0x201]
 
 
 
 
 
1203 * - 'M' For a 6-byte MAC address, it prints the address in the
1204 *       usual colon-separated hex notation
1205 * - 'm' For a 6-byte MAC address, it prints the hex address without colons
1206 * - 'MF' For a 6-byte MAC FDDI address, it prints the address
1207 *       with a dash-separated hex notation
1208 * - '[mM]R' For a 6-byte MAC address, Reverse order (Bluetooth)
1209 * - 'I' [46] for IPv4/IPv6 addresses printed in the usual way
1210 *       IPv4 uses dot-separated decimal without leading 0's (1.2.3.4)
1211 *       IPv6 uses colon separated network-order 16 bit hex with leading 0's
1212 *       [S][pfs]
1213 *       Generic IPv4/IPv6 address (struct sockaddr *) that falls back to
1214 *       [4] or [6] and is able to print port [p], flowinfo [f], scope [s]
1215 * - 'i' [46] for 'raw' IPv4/IPv6 addresses
1216 *       IPv6 omits the colons (01020304...0f)
1217 *       IPv4 uses dot-separated decimal with leading 0's (010.123.045.006)
1218 *       [S][pfs]
1219 *       Generic IPv4/IPv6 address (struct sockaddr *) that falls back to
1220 *       [4] or [6] and is able to print port [p], flowinfo [f], scope [s]
1221 * - '[Ii][4S][hnbl]' IPv4 addresses in host, network, big or little endian order
1222 * - 'I[6S]c' for IPv6 addresses printed as specified by
1223 *       http://tools.ietf.org/html/rfc5952
 
 
 
 
 
 
 
 
 
 
 
1224 * - 'U' For a 16 byte UUID/GUID, it prints the UUID/GUID in the form
1225 *       "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx"
1226 *       Options for %pU are:
1227 *         b big endian lower case hex (default)
1228 *         B big endian UPPER case hex
1229 *         l little endian lower case hex
1230 *         L little endian UPPER case hex
1231 *           big endian output byte order is:
1232 *             [0][1][2][3]-[4][5]-[6][7]-[8][9]-[10][11][12][13][14][15]
1233 *           little endian output byte order is:
1234 *             [3][2][1][0]-[5][4]-[7][6]-[8][9]-[10][11][12][13][14][15]
1235 * - 'V' For a struct va_format which contains a format string * and va_list *,
1236 *       call vsnprintf(->format, *->va_list).
1237 *       Implements a "recursive vsnprintf".
1238 *       Do not use this feature without some mechanism to verify the
1239 *       correctness of the format string and va_list arguments.
1240 * - 'K' For a kernel pointer that should be hidden from unprivileged users
 
 
1241 * - 'NF' For a netdev_features_t
 
1242 * - 'h[CDN]' For a variable-length buffer, it prints it as a hex string with
1243 *            a certain separator (' ' by default):
1244 *              C colon
1245 *              D dash
1246 *              N no separator
1247 *            The maximum supported length is 64 bytes of the input. Consider
1248 *            to use print_hex_dump() for the larger input.
1249 * - 'a[pd]' For address types [p] phys_addr_t, [d] dma_addr_t and derivatives
1250 *           (default assumed to be phys_addr_t, passed by reference)
1251 * - 'd[234]' For a dentry name (optionally 2-4 last components)
1252 * - 'D[234]' Same as 'd' but for a struct file
1253 *
1254 * Note: The difference between 'S' and 'F' is that on ia64 and ppc64
1255 * function pointers are really function descriptors, which contain a
1256 * pointer to the real address.
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1257 */
1258static noinline_for_stack
1259char *pointer(const char *fmt, char *buf, char *end, void *ptr,
1260	      struct printf_spec spec)
1261{
1262	int default_width = 2 * sizeof(void *) + (spec.flags & SPECIAL ? 2 : 0);
1263
1264	if (!ptr && *fmt != 'K') {
1265		/*
1266		 * Print (null) with the same width as a pointer so it makes
1267		 * tabular output look nice.
1268		 */
1269		if (spec.field_width == -1)
1270			spec.field_width = default_width;
1271		return string(buf, end, "(null)", spec);
1272	}
1273
1274	switch (*fmt) {
1275	case 'F':
1276	case 'f':
1277		ptr = dereference_function_descriptor(ptr);
1278		/* Fallthrough */
1279	case 'S':
1280	case 's':
 
 
1281	case 'B':
1282		return symbol_string(buf, end, ptr, spec, fmt);
1283	case 'R':
1284	case 'r':
1285		return resource_string(buf, end, ptr, spec, fmt);
1286	case 'h':
1287		return hex_string(buf, end, ptr, spec, fmt);
 
 
 
 
 
 
 
1288	case 'M':			/* Colon separated: 00:01:02:03:04:05 */
1289	case 'm':			/* Contiguous: 000102030405 */
1290					/* [mM]F (FDDI) */
1291					/* [mM]R (Reverse order; Bluetooth) */
1292		return mac_address_string(buf, end, ptr, spec, fmt);
1293	case 'I':			/* Formatted IP supported
1294					 * 4:	1.2.3.4
1295					 * 6:	0001:0203:...:0708
1296					 * 6c:	1::708 or 1::1.2.3.4
1297					 */
1298	case 'i':			/* Contiguous:
1299					 * 4:	001.002.003.004
1300					 * 6:   000102...0f
1301					 */
1302		switch (fmt[1]) {
1303		case '6':
1304			return ip6_addr_string(buf, end, ptr, spec, fmt);
1305		case '4':
1306			return ip4_addr_string(buf, end, ptr, spec, fmt);
1307		case 'S': {
1308			const union {
1309				struct sockaddr		raw;
1310				struct sockaddr_in	v4;
1311				struct sockaddr_in6	v6;
1312			} *sa = ptr;
1313
1314			switch (sa->raw.sa_family) {
1315			case AF_INET:
1316				return ip4_addr_string_sa(buf, end, &sa->v4, spec, fmt);
1317			case AF_INET6:
1318				return ip6_addr_string_sa(buf, end, &sa->v6, spec, fmt);
1319			default:
1320				return string(buf, end, "(invalid address)", spec);
1321			}}
1322		}
1323		break;
1324	case 'U':
1325		return uuid_string(buf, end, ptr, spec, fmt);
1326	case 'V':
1327		{
1328			va_list va;
1329
1330			va_copy(va, *((struct va_format *)ptr)->va);
1331			buf += vsnprintf(buf, end > buf ? end - buf : 0,
1332					 ((struct va_format *)ptr)->fmt, va);
1333			va_end(va);
1334			return buf;
1335		}
1336	case 'K':
1337		/*
1338		 * %pK cannot be used in IRQ context because its test
1339		 * for CAP_SYSLOG would be meaningless.
1340		 */
1341		if (kptr_restrict && (in_irq() || in_serving_softirq() ||
1342				      in_nmi())) {
1343			if (spec.field_width == -1)
1344				spec.field_width = default_width;
1345			return string(buf, end, "pK-error", spec);
1346		}
1347
1348		switch (kptr_restrict) {
1349		case 0:
1350			/* Always print %pK values */
1351			break;
1352		case 1: {
1353			/*
1354			 * Only print the real pointer value if the current
1355			 * process has CAP_SYSLOG and is running with the
1356			 * same credentials it started with. This is because
1357			 * access to files is checked at open() time, but %pK
1358			 * checks permission at read() time. We don't want to
1359			 * leak pointer values if a binary opens a file using
1360			 * %pK and then elevates privileges before reading it.
1361			 */
1362			const struct cred *cred = current_cred();
1363
1364			if (!has_capability_noaudit(current, CAP_SYSLOG) ||
1365			    !uid_eq(cred->euid, cred->uid) ||
1366			    !gid_eq(cred->egid, cred->gid))
1367				ptr = NULL;
1368			break;
1369		}
1370		case 2:
1371		default:
1372			/* Always print 0's for %pK */
1373			ptr = NULL;
1374			break;
1375		}
1376		break;
1377
1378	case 'N':
1379		switch (fmt[1]) {
1380		case 'F':
1381			return netdev_feature_string(buf, end, ptr, spec);
1382		}
1383		break;
1384	case 'a':
1385		return address_val(buf, end, ptr, spec, fmt);
1386	case 'd':
1387		return dentry_name(buf, end, ptr, spec, fmt);
 
 
 
 
1388	case 'D':
1389		return dentry_name(buf, end,
1390				   ((const struct file *)ptr)->f_path.dentry,
1391				   spec, fmt);
1392	}
1393	spec.flags |= SMALL;
1394	if (spec.field_width == -1) {
1395		spec.field_width = default_width;
1396		spec.flags |= ZEROPAD;
1397	}
1398	spec.base = 16;
1399
1400	return number(buf, end, (unsigned long) ptr, spec);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1401}
1402
1403/*
1404 * Helper function to decode printf style format.
1405 * Each call decode a token from the format and return the
1406 * number of characters read (or likely the delta where it wants
1407 * to go on the next call).
1408 * The decoded token is returned through the parameters
1409 *
1410 * 'h', 'l', or 'L' for integer fields
1411 * 'z' support added 23/7/1999 S.H.
1412 * 'z' changed to 'Z' --davidm 1/25/99
 
1413 * 't' added for ptrdiff_t
1414 *
1415 * @fmt: the format string
1416 * @type of the token returned
1417 * @flags: various flags such as +, -, # tokens..
1418 * @field_width: overwritten width
1419 * @base: base of the number (octal, hex, ...)
1420 * @precision: precision of a number
1421 * @qualifier: qualifier of a number (long, size_t, ...)
1422 */
1423static noinline_for_stack
1424int format_decode(const char *fmt, struct printf_spec *spec)
1425{
1426	const char *start = fmt;
 
1427
1428	/* we finished early by reading the field width */
1429	if (spec->type == FORMAT_TYPE_WIDTH) {
1430		if (spec->field_width < 0) {
1431			spec->field_width = -spec->field_width;
1432			spec->flags |= LEFT;
1433		}
1434		spec->type = FORMAT_TYPE_NONE;
1435		goto precision;
1436	}
1437
1438	/* we finished early by reading the precision */
1439	if (spec->type == FORMAT_TYPE_PRECISION) {
1440		if (spec->precision < 0)
1441			spec->precision = 0;
1442
1443		spec->type = FORMAT_TYPE_NONE;
1444		goto qualifier;
1445	}
1446
1447	/* By default */
1448	spec->type = FORMAT_TYPE_NONE;
1449
1450	for (; *fmt ; ++fmt) {
1451		if (*fmt == '%')
1452			break;
1453	}
1454
1455	/* Return the current non-format string */
1456	if (fmt != start || !*fmt)
1457		return fmt - start;
1458
1459	/* Process flags */
1460	spec->flags = 0;
1461
1462	while (1) { /* this also skips first '%' */
1463		bool found = true;
1464
1465		++fmt;
1466
1467		switch (*fmt) {
1468		case '-': spec->flags |= LEFT;    break;
1469		case '+': spec->flags |= PLUS;    break;
1470		case ' ': spec->flags |= SPACE;   break;
1471		case '#': spec->flags |= SPECIAL; break;
1472		case '0': spec->flags |= ZEROPAD; break;
1473		default:  found = false;
1474		}
1475
1476		if (!found)
1477			break;
1478	}
1479
1480	/* get field width */
1481	spec->field_width = -1;
1482
1483	if (isdigit(*fmt))
1484		spec->field_width = skip_atoi(&fmt);
1485	else if (*fmt == '*') {
1486		/* it's the next argument */
1487		spec->type = FORMAT_TYPE_WIDTH;
1488		return ++fmt - start;
1489	}
1490
1491precision:
1492	/* get the precision */
1493	spec->precision = -1;
1494	if (*fmt == '.') {
1495		++fmt;
1496		if (isdigit(*fmt)) {
1497			spec->precision = skip_atoi(&fmt);
1498			if (spec->precision < 0)
1499				spec->precision = 0;
1500		} else if (*fmt == '*') {
1501			/* it's the next argument */
1502			spec->type = FORMAT_TYPE_PRECISION;
1503			return ++fmt - start;
1504		}
1505	}
1506
1507qualifier:
1508	/* get the conversion qualifier */
1509	spec->qualifier = -1;
1510	if (*fmt == 'h' || _tolower(*fmt) == 'l' ||
1511	    _tolower(*fmt) == 'z' || *fmt == 't') {
1512		spec->qualifier = *fmt++;
1513		if (unlikely(spec->qualifier == *fmt)) {
1514			if (spec->qualifier == 'l') {
1515				spec->qualifier = 'L';
1516				++fmt;
1517			} else if (spec->qualifier == 'h') {
1518				spec->qualifier = 'H';
1519				++fmt;
1520			}
1521		}
1522	}
1523
1524	/* default base */
1525	spec->base = 10;
1526	switch (*fmt) {
1527	case 'c':
1528		spec->type = FORMAT_TYPE_CHAR;
1529		return ++fmt - start;
1530
1531	case 's':
1532		spec->type = FORMAT_TYPE_STR;
1533		return ++fmt - start;
1534
1535	case 'p':
1536		spec->type = FORMAT_TYPE_PTR;
1537		return fmt - start;
1538		/* skip alnum */
1539
1540	case '%':
1541		spec->type = FORMAT_TYPE_PERCENT_CHAR;
1542		return ++fmt - start;
1543
1544	/* integer number formats - set up the flags and "break" */
1545	case 'o':
1546		spec->base = 8;
1547		break;
1548
1549	case 'x':
1550		spec->flags |= SMALL;
 
1551
1552	case 'X':
1553		spec->base = 16;
1554		break;
1555
1556	case 'd':
1557	case 'i':
1558		spec->flags |= SIGN;
 
1559	case 'u':
1560		break;
1561
1562	case 'n':
1563		/*
1564		 * Since %n poses a greater security risk than utility, treat
1565		 * it as an invalid format specifier. Warn about its use so
1566		 * that new instances don't get added.
1567		 */
1568		WARN_ONCE(1, "Please remove ignored %%n in '%s'\n", fmt);
1569		/* Fall-through */
1570
1571	default:
 
1572		spec->type = FORMAT_TYPE_INVALID;
1573		return fmt - start;
1574	}
1575
1576	if (spec->qualifier == 'L')
1577		spec->type = FORMAT_TYPE_LONG_LONG;
1578	else if (spec->qualifier == 'l') {
1579		if (spec->flags & SIGN)
1580			spec->type = FORMAT_TYPE_LONG;
1581		else
1582			spec->type = FORMAT_TYPE_ULONG;
1583	} else if (_tolower(spec->qualifier) == 'z') {
1584		spec->type = FORMAT_TYPE_SIZE_T;
1585	} else if (spec->qualifier == 't') {
1586		spec->type = FORMAT_TYPE_PTRDIFF;
1587	} else if (spec->qualifier == 'H') {
1588		if (spec->flags & SIGN)
1589			spec->type = FORMAT_TYPE_BYTE;
1590		else
1591			spec->type = FORMAT_TYPE_UBYTE;
1592	} else if (spec->qualifier == 'h') {
1593		if (spec->flags & SIGN)
1594			spec->type = FORMAT_TYPE_SHORT;
1595		else
1596			spec->type = FORMAT_TYPE_USHORT;
1597	} else {
1598		if (spec->flags & SIGN)
1599			spec->type = FORMAT_TYPE_INT;
1600		else
1601			spec->type = FORMAT_TYPE_UINT;
1602	}
1603
1604	return ++fmt - start;
1605}
1606
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1607/**
1608 * vsnprintf - Format a string and place it in a buffer
1609 * @buf: The buffer to place the result into
1610 * @size: The size of the buffer, including the trailing null space
1611 * @fmt: The format string to use
1612 * @args: Arguments for the format string
1613 *
1614 * This function follows C99 vsnprintf, but has some extensions:
1615 * %pS output the name of a text symbol with offset
1616 * %ps output the name of a text symbol without offset
1617 * %pF output the name of a function pointer with its offset
1618 * %pf output the name of a function pointer without its offset
1619 * %pB output the name of a backtrace symbol with its offset
1620 * %pR output the address range in a struct resource with decoded flags
1621 * %pr output the address range in a struct resource with raw flags
1622 * %pM output a 6-byte MAC address with colons
1623 * %pMR output a 6-byte MAC address with colons in reversed order
1624 * %pMF output a 6-byte MAC address with dashes
1625 * %pm output a 6-byte MAC address without colons
1626 * %pmR output a 6-byte MAC address without colons in reversed order
1627 * %pI4 print an IPv4 address without leading zeros
1628 * %pi4 print an IPv4 address with leading zeros
1629 * %pI6 print an IPv6 address with colons
1630 * %pi6 print an IPv6 address without colons
1631 * %pI6c print an IPv6 address as specified by RFC 5952
1632 * %pIS depending on sa_family of 'struct sockaddr *' print IPv4/IPv6 address
1633 * %piS depending on sa_family of 'struct sockaddr *' print IPv4/IPv6 address
1634 * %pU[bBlL] print a UUID/GUID in big or little endian using lower or upper
1635 *   case.
1636 * %*ph[CDN] a variable-length hex string with a separator (supports up to 64
1637 *           bytes of the input)
1638 * %n is ignored
1639 *
1640 * ** Please update Documentation/printk-formats.txt when making changes **
 
 
 
1641 *
1642 * The return value is the number of characters which would
1643 * be generated for the given input, excluding the trailing
1644 * '\0', as per ISO C99. If you want to have the exact
1645 * number of characters written into @buf as return value
1646 * (not including the trailing '\0'), use vscnprintf(). If the
1647 * return is greater than or equal to @size, the resulting
1648 * string is truncated.
1649 *
1650 * If you're not already dealing with a va_list consider using snprintf().
1651 */
1652int vsnprintf(char *buf, size_t size, const char *fmt, va_list args)
1653{
1654	unsigned long long num;
1655	char *str, *end;
1656	struct printf_spec spec = {0};
1657
1658	/* Reject out-of-range values early.  Large positive sizes are
1659	   used for unknown buffer sizes. */
1660	if (WARN_ON_ONCE((int) size < 0))
1661		return 0;
1662
1663	str = buf;
1664	end = buf + size;
1665
1666	/* Make sure end is always >= buf */
1667	if (end < buf) {
1668		end = ((void *)-1);
1669		size = end - buf;
1670	}
1671
1672	while (*fmt) {
1673		const char *old_fmt = fmt;
1674		int read = format_decode(fmt, &spec);
1675
1676		fmt += read;
1677
1678		switch (spec.type) {
1679		case FORMAT_TYPE_NONE: {
1680			int copy = read;
1681			if (str < end) {
1682				if (copy > end - str)
1683					copy = end - str;
1684				memcpy(str, old_fmt, copy);
1685			}
1686			str += read;
1687			break;
1688		}
1689
1690		case FORMAT_TYPE_WIDTH:
1691			spec.field_width = va_arg(args, int);
1692			break;
1693
1694		case FORMAT_TYPE_PRECISION:
1695			spec.precision = va_arg(args, int);
1696			break;
1697
1698		case FORMAT_TYPE_CHAR: {
1699			char c;
1700
1701			if (!(spec.flags & LEFT)) {
1702				while (--spec.field_width > 0) {
1703					if (str < end)
1704						*str = ' ';
1705					++str;
1706
1707				}
1708			}
1709			c = (unsigned char) va_arg(args, int);
1710			if (str < end)
1711				*str = c;
1712			++str;
1713			while (--spec.field_width > 0) {
1714				if (str < end)
1715					*str = ' ';
1716				++str;
1717			}
1718			break;
1719		}
1720
1721		case FORMAT_TYPE_STR:
1722			str = string(str, end, va_arg(args, char *), spec);
1723			break;
1724
1725		case FORMAT_TYPE_PTR:
1726			str = pointer(fmt+1, str, end, va_arg(args, void *),
1727				      spec);
1728			while (isalnum(*fmt))
1729				fmt++;
1730			break;
1731
1732		case FORMAT_TYPE_PERCENT_CHAR:
1733			if (str < end)
1734				*str = '%';
1735			++str;
1736			break;
1737
1738		case FORMAT_TYPE_INVALID:
1739			if (str < end)
1740				*str = '%';
1741			++str;
1742			break;
 
 
 
 
 
1743
1744		default:
1745			switch (spec.type) {
1746			case FORMAT_TYPE_LONG_LONG:
1747				num = va_arg(args, long long);
1748				break;
1749			case FORMAT_TYPE_ULONG:
1750				num = va_arg(args, unsigned long);
1751				break;
1752			case FORMAT_TYPE_LONG:
1753				num = va_arg(args, long);
1754				break;
1755			case FORMAT_TYPE_SIZE_T:
1756				if (spec.flags & SIGN)
1757					num = va_arg(args, ssize_t);
1758				else
1759					num = va_arg(args, size_t);
1760				break;
1761			case FORMAT_TYPE_PTRDIFF:
1762				num = va_arg(args, ptrdiff_t);
1763				break;
1764			case FORMAT_TYPE_UBYTE:
1765				num = (unsigned char) va_arg(args, int);
1766				break;
1767			case FORMAT_TYPE_BYTE:
1768				num = (signed char) va_arg(args, int);
1769				break;
1770			case FORMAT_TYPE_USHORT:
1771				num = (unsigned short) va_arg(args, int);
1772				break;
1773			case FORMAT_TYPE_SHORT:
1774				num = (short) va_arg(args, int);
1775				break;
1776			case FORMAT_TYPE_INT:
1777				num = (int) va_arg(args, int);
1778				break;
1779			default:
1780				num = va_arg(args, unsigned int);
1781			}
1782
1783			str = number(str, end, num, spec);
1784		}
1785	}
1786
 
1787	if (size > 0) {
1788		if (str < end)
1789			*str = '\0';
1790		else
1791			end[-1] = '\0';
1792	}
1793
1794	/* the trailing null byte doesn't count towards the total */
1795	return str-buf;
1796
1797}
1798EXPORT_SYMBOL(vsnprintf);
1799
1800/**
1801 * vscnprintf - Format a string and place it in a buffer
1802 * @buf: The buffer to place the result into
1803 * @size: The size of the buffer, including the trailing null space
1804 * @fmt: The format string to use
1805 * @args: Arguments for the format string
1806 *
1807 * The return value is the number of characters which have been written into
1808 * the @buf not including the trailing '\0'. If @size is == 0 the function
1809 * returns 0.
1810 *
1811 * If you're not already dealing with a va_list consider using scnprintf().
1812 *
1813 * See the vsnprintf() documentation for format string extensions over C99.
1814 */
1815int vscnprintf(char *buf, size_t size, const char *fmt, va_list args)
1816{
1817	int i;
1818
 
 
 
1819	i = vsnprintf(buf, size, fmt, args);
1820
1821	if (likely(i < size))
1822		return i;
1823	if (size != 0)
1824		return size - 1;
1825	return 0;
1826}
1827EXPORT_SYMBOL(vscnprintf);
1828
1829/**
1830 * snprintf - Format a string and place it in a buffer
1831 * @buf: The buffer to place the result into
1832 * @size: The size of the buffer, including the trailing null space
1833 * @fmt: The format string to use
1834 * @...: Arguments for the format string
1835 *
1836 * The return value is the number of characters which would be
1837 * generated for the given input, excluding the trailing null,
1838 * as per ISO C99.  If the return is greater than or equal to
1839 * @size, the resulting string is truncated.
1840 *
1841 * See the vsnprintf() documentation for format string extensions over C99.
1842 */
1843int snprintf(char *buf, size_t size, const char *fmt, ...)
1844{
1845	va_list args;
1846	int i;
1847
1848	va_start(args, fmt);
1849	i = vsnprintf(buf, size, fmt, args);
1850	va_end(args);
1851
1852	return i;
1853}
1854EXPORT_SYMBOL(snprintf);
1855
1856/**
1857 * scnprintf - Format a string and place it in a buffer
1858 * @buf: The buffer to place the result into
1859 * @size: The size of the buffer, including the trailing null space
1860 * @fmt: The format string to use
1861 * @...: Arguments for the format string
1862 *
1863 * The return value is the number of characters written into @buf not including
1864 * the trailing '\0'. If @size is == 0 the function returns 0.
1865 */
1866
1867int scnprintf(char *buf, size_t size, const char *fmt, ...)
1868{
1869	va_list args;
1870	int i;
1871
1872	va_start(args, fmt);
1873	i = vscnprintf(buf, size, fmt, args);
1874	va_end(args);
1875
1876	return i;
1877}
1878EXPORT_SYMBOL(scnprintf);
1879
1880/**
1881 * vsprintf - Format a string and place it in a buffer
1882 * @buf: The buffer to place the result into
1883 * @fmt: The format string to use
1884 * @args: Arguments for the format string
1885 *
1886 * The function returns the number of characters written
1887 * into @buf. Use vsnprintf() or vscnprintf() in order to avoid
1888 * buffer overflows.
1889 *
1890 * If you're not already dealing with a va_list consider using sprintf().
1891 *
1892 * See the vsnprintf() documentation for format string extensions over C99.
1893 */
1894int vsprintf(char *buf, const char *fmt, va_list args)
1895{
1896	return vsnprintf(buf, INT_MAX, fmt, args);
1897}
1898EXPORT_SYMBOL(vsprintf);
1899
1900/**
1901 * sprintf - Format a string and place it in a buffer
1902 * @buf: The buffer to place the result into
1903 * @fmt: The format string to use
1904 * @...: Arguments for the format string
1905 *
1906 * The function returns the number of characters written
1907 * into @buf. Use snprintf() or scnprintf() in order to avoid
1908 * buffer overflows.
1909 *
1910 * See the vsnprintf() documentation for format string extensions over C99.
1911 */
1912int sprintf(char *buf, const char *fmt, ...)
1913{
1914	va_list args;
1915	int i;
1916
1917	va_start(args, fmt);
1918	i = vsnprintf(buf, INT_MAX, fmt, args);
1919	va_end(args);
1920
1921	return i;
1922}
1923EXPORT_SYMBOL(sprintf);
1924
1925#ifdef CONFIG_BINARY_PRINTF
1926/*
1927 * bprintf service:
1928 * vbin_printf() - VA arguments to binary data
1929 * bstr_printf() - Binary data to text string
1930 */
1931
1932/**
1933 * vbin_printf - Parse a format string and place args' binary value in a buffer
1934 * @bin_buf: The buffer to place args' binary value
1935 * @size: The size of the buffer(by words(32bits), not characters)
1936 * @fmt: The format string to use
1937 * @args: Arguments for the format string
1938 *
1939 * The format follows C99 vsnprintf, except %n is ignored, and its argument
1940 * is skiped.
1941 *
1942 * The return value is the number of words(32bits) which would be generated for
1943 * the given input.
1944 *
1945 * NOTE:
1946 * If the return value is greater than @size, the resulting bin_buf is NOT
1947 * valid for bstr_printf().
1948 */
1949int vbin_printf(u32 *bin_buf, size_t size, const char *fmt, va_list args)
1950{
1951	struct printf_spec spec = {0};
1952	char *str, *end;
 
1953
1954	str = (char *)bin_buf;
1955	end = (char *)(bin_buf + size);
1956
1957#define save_arg(type)							\
1958do {									\
 
1959	if (sizeof(type) == 8) {					\
1960		unsigned long long value;				\
1961		str = PTR_ALIGN(str, sizeof(u32));			\
1962		value = va_arg(args, unsigned long long);		\
1963		if (str + sizeof(type) <= end) {			\
1964			*(u32 *)str = *(u32 *)&value;			\
1965			*(u32 *)(str + 4) = *((u32 *)&value + 1);	\
1966		}							\
 
1967	} else {							\
1968		unsigned long value;					\
1969		str = PTR_ALIGN(str, sizeof(type));			\
1970		value = va_arg(args, int);				\
1971		if (str + sizeof(type) <= end)				\
1972			*(typeof(type) *)str = (type)value;		\
 
1973	}								\
1974	str += sizeof(type);						\
1975} while (0)
 
1976
1977	while (*fmt) {
1978		int read = format_decode(fmt, &spec);
1979
1980		fmt += read;
1981
1982		switch (spec.type) {
1983		case FORMAT_TYPE_NONE:
1984		case FORMAT_TYPE_INVALID:
1985		case FORMAT_TYPE_PERCENT_CHAR:
1986			break;
 
 
1987
1988		case FORMAT_TYPE_WIDTH:
1989		case FORMAT_TYPE_PRECISION:
1990			save_arg(int);
 
 
 
1991			break;
1992
1993		case FORMAT_TYPE_CHAR:
1994			save_arg(char);
1995			break;
1996
1997		case FORMAT_TYPE_STR: {
1998			const char *save_str = va_arg(args, char *);
 
1999			size_t len;
2000
2001			if ((unsigned long)save_str > (unsigned long)-PAGE_SIZE
2002					|| (unsigned long)save_str < PAGE_SIZE)
2003				save_str = "(null)";
 
2004			len = strlen(save_str) + 1;
2005			if (str + len < end)
2006				memcpy(str, save_str, len);
2007			str += len;
2008			break;
2009		}
2010
2011		case FORMAT_TYPE_PTR:
2012			save_arg(void *);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2013			/* skip all alphanumeric pointer suffixes */
2014			while (isalnum(*fmt))
2015				fmt++;
2016			break;
2017
2018		default:
2019			switch (spec.type) {
2020
2021			case FORMAT_TYPE_LONG_LONG:
2022				save_arg(long long);
2023				break;
2024			case FORMAT_TYPE_ULONG:
2025			case FORMAT_TYPE_LONG:
2026				save_arg(unsigned long);
2027				break;
2028			case FORMAT_TYPE_SIZE_T:
2029				save_arg(size_t);
2030				break;
2031			case FORMAT_TYPE_PTRDIFF:
2032				save_arg(ptrdiff_t);
2033				break;
2034			case FORMAT_TYPE_UBYTE:
2035			case FORMAT_TYPE_BYTE:
2036				save_arg(char);
2037				break;
2038			case FORMAT_TYPE_USHORT:
2039			case FORMAT_TYPE_SHORT:
2040				save_arg(short);
2041				break;
2042			default:
2043				save_arg(int);
2044			}
2045		}
2046	}
2047
 
2048	return (u32 *)(PTR_ALIGN(str, sizeof(u32))) - bin_buf;
2049#undef save_arg
2050}
2051EXPORT_SYMBOL_GPL(vbin_printf);
2052
2053/**
2054 * bstr_printf - Format a string from binary arguments and place it in a buffer
2055 * @buf: The buffer to place the result into
2056 * @size: The size of the buffer, including the trailing null space
2057 * @fmt: The format string to use
2058 * @bin_buf: Binary arguments for the format string
2059 *
2060 * This function like C99 vsnprintf, but the difference is that vsnprintf gets
2061 * arguments from stack, and bstr_printf gets arguments from @bin_buf which is
2062 * a binary buffer that generated by vbin_printf.
2063 *
2064 * The format follows C99 vsnprintf, but has some extensions:
2065 *  see vsnprintf comment for details.
2066 *
2067 * The return value is the number of characters which would
2068 * be generated for the given input, excluding the trailing
2069 * '\0', as per ISO C99. If you want to have the exact
2070 * number of characters written into @buf as return value
2071 * (not including the trailing '\0'), use vscnprintf(). If the
2072 * return is greater than or equal to @size, the resulting
2073 * string is truncated.
2074 */
2075int bstr_printf(char *buf, size_t size, const char *fmt, const u32 *bin_buf)
2076{
2077	struct printf_spec spec = {0};
2078	char *str, *end;
2079	const char *args = (const char *)bin_buf;
2080
2081	if (WARN_ON_ONCE((int) size < 0))
2082		return 0;
2083
2084	str = buf;
2085	end = buf + size;
2086
2087#define get_arg(type)							\
2088({									\
2089	typeof(type) value;						\
2090	if (sizeof(type) == 8) {					\
2091		args = PTR_ALIGN(args, sizeof(u32));			\
2092		*(u32 *)&value = *(u32 *)args;				\
2093		*((u32 *)&value + 1) = *(u32 *)(args + 4);		\
2094	} else {							\
2095		args = PTR_ALIGN(args, sizeof(type));			\
2096		value = *(typeof(type) *)args;				\
2097	}								\
2098	args += sizeof(type);						\
2099	value;								\
2100})
2101
2102	/* Make sure end is always >= buf */
2103	if (end < buf) {
2104		end = ((void *)-1);
2105		size = end - buf;
2106	}
2107
2108	while (*fmt) {
2109		const char *old_fmt = fmt;
2110		int read = format_decode(fmt, &spec);
2111
2112		fmt += read;
2113
2114		switch (spec.type) {
2115		case FORMAT_TYPE_NONE: {
2116			int copy = read;
2117			if (str < end) {
2118				if (copy > end - str)
2119					copy = end - str;
2120				memcpy(str, old_fmt, copy);
2121			}
2122			str += read;
2123			break;
2124		}
2125
2126		case FORMAT_TYPE_WIDTH:
2127			spec.field_width = get_arg(int);
2128			break;
2129
2130		case FORMAT_TYPE_PRECISION:
2131			spec.precision = get_arg(int);
2132			break;
2133
2134		case FORMAT_TYPE_CHAR: {
2135			char c;
2136
2137			if (!(spec.flags & LEFT)) {
2138				while (--spec.field_width > 0) {
2139					if (str < end)
2140						*str = ' ';
2141					++str;
2142				}
2143			}
2144			c = (unsigned char) get_arg(char);
2145			if (str < end)
2146				*str = c;
2147			++str;
2148			while (--spec.field_width > 0) {
2149				if (str < end)
2150					*str = ' ';
2151				++str;
2152			}
2153			break;
2154		}
2155
2156		case FORMAT_TYPE_STR: {
2157			const char *str_arg = args;
2158			args += strlen(str_arg) + 1;
2159			str = string(str, end, (char *)str_arg, spec);
2160			break;
2161		}
2162
2163		case FORMAT_TYPE_PTR:
2164			str = pointer(fmt+1, str, end, get_arg(void *), spec);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2165			while (isalnum(*fmt))
2166				fmt++;
2167			break;
 
2168
2169		case FORMAT_TYPE_PERCENT_CHAR:
2170		case FORMAT_TYPE_INVALID:
2171			if (str < end)
2172				*str = '%';
2173			++str;
2174			break;
2175
 
 
 
2176		default: {
2177			unsigned long long num;
2178
2179			switch (spec.type) {
2180
2181			case FORMAT_TYPE_LONG_LONG:
2182				num = get_arg(long long);
2183				break;
2184			case FORMAT_TYPE_ULONG:
2185			case FORMAT_TYPE_LONG:
2186				num = get_arg(unsigned long);
2187				break;
2188			case FORMAT_TYPE_SIZE_T:
2189				num = get_arg(size_t);
2190				break;
2191			case FORMAT_TYPE_PTRDIFF:
2192				num = get_arg(ptrdiff_t);
2193				break;
2194			case FORMAT_TYPE_UBYTE:
2195				num = get_arg(unsigned char);
2196				break;
2197			case FORMAT_TYPE_BYTE:
2198				num = get_arg(signed char);
2199				break;
2200			case FORMAT_TYPE_USHORT:
2201				num = get_arg(unsigned short);
2202				break;
2203			case FORMAT_TYPE_SHORT:
2204				num = get_arg(short);
2205				break;
2206			case FORMAT_TYPE_UINT:
2207				num = get_arg(unsigned int);
2208				break;
2209			default:
2210				num = get_arg(int);
2211			}
2212
2213			str = number(str, end, num, spec);
2214		} /* default: */
2215		} /* switch(spec.type) */
2216	} /* while(*fmt) */
2217
 
2218	if (size > 0) {
2219		if (str < end)
2220			*str = '\0';
2221		else
2222			end[-1] = '\0';
2223	}
2224
2225#undef get_arg
2226
2227	/* the trailing null byte doesn't count towards the total */
2228	return str - buf;
2229}
2230EXPORT_SYMBOL_GPL(bstr_printf);
2231
2232/**
2233 * bprintf - Parse a format string and place args' binary value in a buffer
2234 * @bin_buf: The buffer to place args' binary value
2235 * @size: The size of the buffer(by words(32bits), not characters)
2236 * @fmt: The format string to use
2237 * @...: Arguments for the format string
2238 *
2239 * The function returns the number of words(u32) written
2240 * into @bin_buf.
2241 */
2242int bprintf(u32 *bin_buf, size_t size, const char *fmt, ...)
2243{
2244	va_list args;
2245	int ret;
2246
2247	va_start(args, fmt);
2248	ret = vbin_printf(bin_buf, size, fmt, args);
2249	va_end(args);
2250
2251	return ret;
2252}
2253EXPORT_SYMBOL_GPL(bprintf);
2254
2255#endif /* CONFIG_BINARY_PRINTF */
2256
2257/**
2258 * vsscanf - Unformat a buffer into a list of arguments
2259 * @buf:	input buffer
2260 * @fmt:	format of buffer
2261 * @args:	arguments
2262 */
2263int vsscanf(const char *buf, const char *fmt, va_list args)
2264{
2265	const char *str = buf;
2266	char *next;
2267	char digit;
2268	int num = 0;
2269	u8 qualifier;
2270	unsigned int base;
2271	union {
2272		long long s;
2273		unsigned long long u;
2274	} val;
2275	s16 field_width;
2276	bool is_sign;
2277
2278	while (*fmt) {
2279		/* skip any white space in format */
2280		/* white space in format matchs any amount of
2281		 * white space, including none, in the input.
2282		 */
2283		if (isspace(*fmt)) {
2284			fmt = skip_spaces(++fmt);
2285			str = skip_spaces(str);
2286		}
2287
2288		/* anything that is not a conversion must match exactly */
2289		if (*fmt != '%' && *fmt) {
2290			if (*fmt++ != *str++)
2291				break;
2292			continue;
2293		}
2294
2295		if (!*fmt)
2296			break;
2297		++fmt;
2298
2299		/* skip this conversion.
2300		 * advance both strings to next white space
2301		 */
2302		if (*fmt == '*') {
2303			if (!*str)
2304				break;
2305			while (!isspace(*fmt) && *fmt != '%' && *fmt)
 
 
 
2306				fmt++;
 
2307			while (!isspace(*str) && *str)
2308				str++;
2309			continue;
2310		}
2311
2312		/* get field width */
2313		field_width = -1;
2314		if (isdigit(*fmt)) {
2315			field_width = skip_atoi(&fmt);
2316			if (field_width <= 0)
2317				break;
2318		}
2319
2320		/* get conversion qualifier */
2321		qualifier = -1;
2322		if (*fmt == 'h' || _tolower(*fmt) == 'l' ||
2323		    _tolower(*fmt) == 'z') {
2324			qualifier = *fmt++;
2325			if (unlikely(qualifier == *fmt)) {
2326				if (qualifier == 'h') {
2327					qualifier = 'H';
2328					fmt++;
2329				} else if (qualifier == 'l') {
2330					qualifier = 'L';
2331					fmt++;
2332				}
2333			}
2334		}
2335
2336		if (!*fmt)
2337			break;
2338
2339		if (*fmt == 'n') {
2340			/* return number of characters read so far */
2341			*va_arg(args, int *) = str - buf;
2342			++fmt;
2343			continue;
2344		}
2345
2346		if (!*str)
2347			break;
2348
2349		base = 10;
2350		is_sign = 0;
2351
2352		switch (*fmt++) {
2353		case 'c':
2354		{
2355			char *s = (char *)va_arg(args, char*);
2356			if (field_width == -1)
2357				field_width = 1;
2358			do {
2359				*s++ = *str++;
2360			} while (--field_width > 0 && *str);
2361			num++;
2362		}
2363		continue;
2364		case 's':
2365		{
2366			char *s = (char *)va_arg(args, char *);
2367			if (field_width == -1)
2368				field_width = SHRT_MAX;
2369			/* first, skip leading white space in buffer */
2370			str = skip_spaces(str);
2371
2372			/* now copy until next white space */
2373			while (*str && !isspace(*str) && field_width--)
2374				*s++ = *str++;
2375			*s = '\0';
2376			num++;
2377		}
2378		continue;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2379		case 'o':
2380			base = 8;
2381			break;
2382		case 'x':
2383		case 'X':
2384			base = 16;
2385			break;
2386		case 'i':
2387			base = 0;
 
2388		case 'd':
2389			is_sign = 1;
 
2390		case 'u':
2391			break;
2392		case '%':
2393			/* looking for '%' in str */
2394			if (*str++ != '%')
2395				return num;
2396			continue;
2397		default:
2398			/* invalid format; stop here */
2399			return num;
2400		}
2401
2402		/* have some sort of integer conversion.
2403		 * first, skip white space in buffer.
2404		 */
2405		str = skip_spaces(str);
2406
2407		digit = *str;
2408		if (is_sign && digit == '-')
 
 
 
2409			digit = *(str + 1);
 
2410
2411		if (!digit
2412		    || (base == 16 && !isxdigit(digit))
2413		    || (base == 10 && !isdigit(digit))
2414		    || (base == 8 && (!isdigit(digit) || digit > '7'))
2415		    || (base == 0 && !isdigit(digit)))
2416			break;
2417
2418		if (is_sign)
2419			val.s = qualifier != 'L' ?
2420				simple_strtol(str, &next, base) :
2421				simple_strtoll(str, &next, base);
2422		else
2423			val.u = qualifier != 'L' ?
2424				simple_strtoul(str, &next, base) :
2425				simple_strtoull(str, &next, base);
2426
2427		if (field_width > 0 && next - str > field_width) {
2428			if (base == 0)
2429				_parse_integer_fixup_radix(str, &base);
2430			while (next - str > field_width) {
2431				if (is_sign)
2432					val.s = div_s64(val.s, base);
2433				else
2434					val.u = div_u64(val.u, base);
2435				--next;
2436			}
2437		}
2438
2439		switch (qualifier) {
2440		case 'H':	/* that's 'hh' in format */
2441			if (is_sign)
2442				*va_arg(args, signed char *) = val.s;
2443			else
2444				*va_arg(args, unsigned char *) = val.u;
2445			break;
2446		case 'h':
2447			if (is_sign)
2448				*va_arg(args, short *) = val.s;
2449			else
2450				*va_arg(args, unsigned short *) = val.u;
2451			break;
2452		case 'l':
2453			if (is_sign)
2454				*va_arg(args, long *) = val.s;
2455			else
2456				*va_arg(args, unsigned long *) = val.u;
2457			break;
2458		case 'L':
2459			if (is_sign)
2460				*va_arg(args, long long *) = val.s;
2461			else
2462				*va_arg(args, unsigned long long *) = val.u;
2463			break;
2464		case 'Z':
2465		case 'z':
2466			*va_arg(args, size_t *) = val.u;
2467			break;
2468		default:
2469			if (is_sign)
2470				*va_arg(args, int *) = val.s;
2471			else
2472				*va_arg(args, unsigned int *) = val.u;
2473			break;
2474		}
2475		num++;
2476
2477		if (!next)
2478			break;
2479		str = next;
2480	}
2481
2482	return num;
2483}
2484EXPORT_SYMBOL(vsscanf);
2485
2486/**
2487 * sscanf - Unformat a buffer into a list of arguments
2488 * @buf:	input buffer
2489 * @fmt:	formatting of buffer
2490 * @...:	resulting arguments
2491 */
2492int sscanf(const char *buf, const char *fmt, ...)
2493{
2494	va_list args;
2495	int i;
2496
2497	va_start(args, fmt);
2498	i = vsscanf(buf, fmt, args);
2499	va_end(args);
2500
2501	return i;
2502}
2503EXPORT_SYMBOL(sscanf);
v6.13.7
   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 *  linux/lib/vsprintf.c
   4 *
   5 *  Copyright (C) 1991, 1992  Linus Torvalds
   6 */
   7
   8/* vsprintf.c -- Lars Wirzenius & Linus Torvalds. */
   9/*
  10 * Wirzenius wrote this portably, Torvalds fucked it up :-)
  11 */
  12
  13/*
  14 * Fri Jul 13 2001 Crutcher Dunnavant <crutcher+kernel@datastacks.com>
  15 * - changed to provide snprintf and vsnprintf functions
  16 * So Feb  1 16:51:32 CET 2004 Juergen Quade <quade@hsnr.de>
  17 * - scnprintf and vscnprintf
  18 */
  19
  20#include <linux/stdarg.h>
  21#include <linux/build_bug.h>
  22#include <linux/clk.h>
  23#include <linux/clk-provider.h>
  24#include <linux/errname.h>
  25#include <linux/module.h>	/* for KSYM_SYMBOL_LEN */
  26#include <linux/types.h>
  27#include <linux/string.h>
  28#include <linux/ctype.h>
  29#include <linux/kernel.h>
  30#include <linux/kallsyms.h>
  31#include <linux/math64.h>
  32#include <linux/uaccess.h>
  33#include <linux/ioport.h>
  34#include <linux/dcache.h>
  35#include <linux/cred.h>
  36#include <linux/rtc.h>
  37#include <linux/sprintf.h>
  38#include <linux/time.h>
  39#include <linux/uuid.h>
  40#include <linux/of.h>
  41#include <net/addrconf.h>
  42#include <linux/siphash.h>
  43#include <linux/compiler.h>
  44#include <linux/property.h>
  45#include <linux/notifier.h>
  46#ifdef CONFIG_BLOCK
  47#include <linux/blkdev.h>
  48#endif
  49
  50#include "../mm/internal.h"	/* For the trace_print_flags arrays */
  51
  52#include <asm/page.h>		/* for PAGE_SIZE */
  53#include <asm/byteorder.h>	/* cpu_to_le16 */
  54#include <linux/unaligned.h>
  55
  56#include <linux/string_helpers.h>
  57#include "kstrtox.h"
  58
  59/* Disable pointer hashing if requested */
  60bool no_hash_pointers __ro_after_init;
  61EXPORT_SYMBOL_GPL(no_hash_pointers);
  62
  63noinline
  64static unsigned long long simple_strntoull(const char *startp, char **endp, unsigned int base, size_t max_chars)
  65{
  66	const char *cp;
  67	unsigned long long result = 0ULL;
  68	size_t prefix_chars;
  69	unsigned int rv;
  70
  71	cp = _parse_integer_fixup_radix(startp, &base);
  72	prefix_chars = cp - startp;
  73	if (prefix_chars < max_chars) {
  74		rv = _parse_integer_limit(cp, base, &result, max_chars - prefix_chars);
  75		/* FIXME */
  76		cp += (rv & ~KSTRTOX_OVERFLOW);
  77	} else {
  78		/* Field too short for prefix + digit, skip over without converting */
  79		cp = startp + max_chars;
  80	}
  81
  82	if (endp)
  83		*endp = (char *)cp;
  84
  85	return result;
  86}
  87
  88/**
  89 * simple_strtoull - convert a string to an unsigned long long
  90 * @cp: The start of the string
  91 * @endp: A pointer to the end of the parsed string will be placed here
  92 * @base: The number base to use
  93 *
  94 * This function has caveats. Please use kstrtoull instead.
  95 */
  96noinline
  97unsigned long long simple_strtoull(const char *cp, char **endp, unsigned int base)
  98{
  99	return simple_strntoull(cp, endp, base, INT_MAX);
 
 
 
 
 
 
 
 
 
 
 
 100}
 101EXPORT_SYMBOL(simple_strtoull);
 102
 103/**
 104 * simple_strtoul - convert a string to an unsigned long
 105 * @cp: The start of the string
 106 * @endp: A pointer to the end of the parsed string will be placed here
 107 * @base: The number base to use
 108 *
 109 * This function has caveats. Please use kstrtoul instead.
 110 */
 111unsigned long simple_strtoul(const char *cp, char **endp, unsigned int base)
 112{
 113	return simple_strtoull(cp, endp, base);
 114}
 115EXPORT_SYMBOL(simple_strtoul);
 116
 117/**
 118 * simple_strtol - convert a string to a signed long
 119 * @cp: The start of the string
 120 * @endp: A pointer to the end of the parsed string will be placed here
 121 * @base: The number base to use
 122 *
 123 * This function has caveats. Please use kstrtol instead.
 124 */
 125long simple_strtol(const char *cp, char **endp, unsigned int base)
 126{
 127	if (*cp == '-')
 128		return -simple_strtoul(cp + 1, endp, base);
 129
 130	return simple_strtoul(cp, endp, base);
 131}
 132EXPORT_SYMBOL(simple_strtol);
 133
 134noinline
 135static long long simple_strntoll(const char *cp, char **endp, unsigned int base, size_t max_chars)
 136{
 137	/*
 138	 * simple_strntoull() safely handles receiving max_chars==0 in the
 139	 * case cp[0] == '-' && max_chars == 1.
 140	 * If max_chars == 0 we can drop through and pass it to simple_strntoull()
 141	 * and the content of *cp is irrelevant.
 142	 */
 143	if (*cp == '-' && max_chars > 0)
 144		return -simple_strntoull(cp + 1, endp, base, max_chars - 1);
 145
 146	return simple_strntoull(cp, endp, base, max_chars);
 147}
 148
 149/**
 150 * simple_strtoll - convert a string to a signed long long
 151 * @cp: The start of the string
 152 * @endp: A pointer to the end of the parsed string will be placed here
 153 * @base: The number base to use
 154 *
 155 * This function has caveats. Please use kstrtoll instead.
 156 */
 157long long simple_strtoll(const char *cp, char **endp, unsigned int base)
 158{
 159	return simple_strntoll(cp, endp, base, INT_MAX);
 
 
 
 160}
 161EXPORT_SYMBOL(simple_strtoll);
 162
 163static noinline_for_stack
 164int skip_atoi(const char **s)
 165{
 166	int i = 0;
 167
 168	do {
 169		i = i*10 + *((*s)++) - '0';
 170	} while (isdigit(**s));
 171
 172	return i;
 173}
 174
 175/*
 176 * Decimal conversion is by far the most typical, and is used for
 177 * /proc and /sys data. This directly impacts e.g. top performance
 178 * with many processes running. We optimize it for speed by emitting
 179 * two characters at a time, using a 200 byte lookup table. This
 180 * roughly halves the number of multiplications compared to computing
 181 * the digits one at a time. Implementation strongly inspired by the
 182 * previous version, which in turn used ideas described at
 183 * <http://www.cs.uiowa.edu/~jones/bcd/divide.html> (with permission
 184 * from the author, Douglas W. Jones).
 185 *
 186 * It turns out there is precisely one 26 bit fixed-point
 187 * approximation a of 64/100 for which x/100 == (x * (u64)a) >> 32
 188 * holds for all x in [0, 10^8-1], namely a = 0x28f5c29. The actual
 189 * range happens to be somewhat larger (x <= 1073741898), but that's
 190 * irrelevant for our purpose.
 191 *
 192 * For dividing a number in the range [10^4, 10^6-1] by 100, we still
 193 * need a 32x32->64 bit multiply, so we simply use the same constant.
 194 *
 195 * For dividing a number in the range [100, 10^4-1] by 100, there are
 196 * several options. The simplest is (x * 0x147b) >> 19, which is valid
 197 * for all x <= 43698.
 198 */
 199
 200static const u16 decpair[100] = {
 201#define _(x) (__force u16) cpu_to_le16(((x % 10) | ((x / 10) << 8)) + 0x3030)
 202	_( 0), _( 1), _( 2), _( 3), _( 4), _( 5), _( 6), _( 7), _( 8), _( 9),
 203	_(10), _(11), _(12), _(13), _(14), _(15), _(16), _(17), _(18), _(19),
 204	_(20), _(21), _(22), _(23), _(24), _(25), _(26), _(27), _(28), _(29),
 205	_(30), _(31), _(32), _(33), _(34), _(35), _(36), _(37), _(38), _(39),
 206	_(40), _(41), _(42), _(43), _(44), _(45), _(46), _(47), _(48), _(49),
 207	_(50), _(51), _(52), _(53), _(54), _(55), _(56), _(57), _(58), _(59),
 208	_(60), _(61), _(62), _(63), _(64), _(65), _(66), _(67), _(68), _(69),
 209	_(70), _(71), _(72), _(73), _(74), _(75), _(76), _(77), _(78), _(79),
 210	_(80), _(81), _(82), _(83), _(84), _(85), _(86), _(87), _(88), _(89),
 211	_(90), _(91), _(92), _(93), _(94), _(95), _(96), _(97), _(98), _(99),
 212#undef _
 213};
 214
 215/*
 216 * This will print a single '0' even if r == 0, since we would
 217 * immediately jump to out_r where two 0s would be written but only
 218 * one of them accounted for in buf. This is needed by ip4_string
 219 * below. All other callers pass a non-zero value of r.
 220*/
 221static noinline_for_stack
 222char *put_dec_trunc8(char *buf, unsigned r)
 223{
 224	unsigned q;
 225
 226	/* 1 <= r < 10^8 */
 227	if (r < 100)
 228		goto out_r;
 229
 230	/* 100 <= r < 10^8 */
 231	q = (r * (u64)0x28f5c29) >> 32;
 232	*((u16 *)buf) = decpair[r - 100*q];
 233	buf += 2;
 234
 235	/* 1 <= q < 10^6 */
 236	if (q < 100)
 237		goto out_q;
 238
 239	/*  100 <= q < 10^6 */
 240	r = (q * (u64)0x28f5c29) >> 32;
 241	*((u16 *)buf) = decpair[q - 100*r];
 242	buf += 2;
 243
 244	/* 1 <= r < 10^4 */
 245	if (r < 100)
 246		goto out_r;
 247
 248	/* 100 <= r < 10^4 */
 249	q = (r * 0x147b) >> 19;
 250	*((u16 *)buf) = decpair[r - 100*q];
 251	buf += 2;
 252out_q:
 253	/* 1 <= q < 100 */
 254	r = q;
 255out_r:
 256	/* 1 <= r < 100 */
 257	*((u16 *)buf) = decpair[r];
 258	buf += r < 10 ? 1 : 2;
 
 
 
 
 259	return buf;
 260}
 
 261
 262#if BITS_PER_LONG == 64 && BITS_PER_LONG_LONG == 64
 
 
 
 263static noinline_for_stack
 264char *put_dec_full8(char *buf, unsigned r)
 265{
 266	unsigned q;
 267
 268	/* 0 <= r < 10^8 */
 269	q = (r * (u64)0x28f5c29) >> 32;
 270	*((u16 *)buf) = decpair[r - 100*q];
 271	buf += 2;
 272
 273	/* 0 <= q < 10^6 */
 274	r = (q * (u64)0x28f5c29) >> 32;
 275	*((u16 *)buf) = decpair[q - 100*r];
 276	buf += 2;
 277
 278	/* 0 <= r < 10^4 */
 279	q = (r * 0x147b) >> 19;
 280	*((u16 *)buf) = decpair[r - 100*q];
 281	buf += 2;
 282
 283	/* 0 <= q < 100 */
 284	*((u16 *)buf) = decpair[q];
 285	buf += 2;
 
 
 286	return buf;
 287}
 288
 289static noinline_for_stack
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 290char *put_dec(char *buf, unsigned long long n)
 291{
 292	if (n >= 100*1000*1000)
 293		buf = put_dec_full8(buf, do_div(n, 100*1000*1000));
 294	/* 1 <= n <= 1.6e11 */
 295	if (n >= 100*1000*1000)
 296		buf = put_dec_full8(buf, do_div(n, 100*1000*1000));
 297	/* 1 <= n < 1e8 */
 298	return put_dec_trunc8(buf, n);
 299}
 300
 301#elif BITS_PER_LONG == 32 && BITS_PER_LONG_LONG == 64
 
 
 302
 303static void
 304put_dec_full4(char *buf, unsigned r)
 
 305{
 306	unsigned q;
 307
 308	/* 0 <= r < 10^4 */
 309	q = (r * 0x147b) >> 19;
 310	*((u16 *)buf) = decpair[r - 100*q];
 311	buf += 2;
 312	/* 0 <= q < 100 */
 313	*((u16 *)buf) = decpair[q];
 314}
 315
 316/*
 317 * Call put_dec_full4 on x % 10000, return x / 10000.
 318 * The approximation x/10000 == (x * 0x346DC5D7) >> 43
 319 * holds for all x < 1,128,869,999.  The largest value this
 320 * helper will ever be asked to convert is 1,125,520,955.
 321 * (second call in the put_dec code, assuming n is all-ones).
 322 */
 323static noinline_for_stack
 324unsigned put_dec_helper4(char *buf, unsigned x)
 325{
 326        uint32_t q = (x * (uint64_t)0x346DC5D7) >> 43;
 327
 328        put_dec_full4(buf, x - q * 10000);
 329        return q;
 330}
 331
 332/* Based on code by Douglas W. Jones found at
 333 * <http://www.cs.uiowa.edu/~jones/bcd/decimal.html#sixtyfour>
 334 * (with permission from the author).
 335 * Performs no 64-bit division and hence should be fast on 32-bit machines.
 336 */
 337static
 338char *put_dec(char *buf, unsigned long long n)
 339{
 340	uint32_t d3, d2, d1, q, h;
 341
 342	if (n < 100*1000*1000)
 343		return put_dec_trunc8(buf, n);
 344
 345	d1  = ((uint32_t)n >> 16); /* implicit "& 0xffff" */
 346	h   = (n >> 32);
 347	d2  = (h      ) & 0xffff;
 348	d3  = (h >> 16); /* implicit "& 0xffff" */
 349
 350	/* n = 2^48 d3 + 2^32 d2 + 2^16 d1 + d0
 351	     = 281_4749_7671_0656 d3 + 42_9496_7296 d2 + 6_5536 d1 + d0 */
 352	q   = 656 * d3 + 7296 * d2 + 5536 * d1 + ((uint32_t)n & 0xffff);
 353	q = put_dec_helper4(buf, q);
 354
 355	q += 7671 * d3 + 9496 * d2 + 6 * d1;
 356	q = put_dec_helper4(buf+4, q);
 357
 358	q += 4749 * d3 + 42 * d2;
 359	q = put_dec_helper4(buf+8, q);
 360
 361	q += 281 * d3;
 362	buf += 12;
 363	if (q)
 364		buf = put_dec_trunc8(buf, q);
 365	else while (buf[-1] == '0')
 366		--buf;
 367
 368	return buf;
 369}
 370
 371#endif
 372
 373/*
 374 * Convert passed number to decimal string.
 375 * Returns the length of string.  On buffer overflow, returns 0.
 376 *
 377 * If speed is not important, use snprintf(). It's easy to read the code.
 378 */
 379int num_to_str(char *buf, int size, unsigned long long num, unsigned int width)
 380{
 381	/* put_dec requires 2-byte alignment of the buffer. */
 382	char tmp[sizeof(num) * 3] __aligned(2);
 383	int idx, len;
 384
 385	/* put_dec() may work incorrectly for num = 0 (generate "", not "0") */
 386	if (num <= 9) {
 387		tmp[0] = '0' + num;
 388		len = 1;
 389	} else {
 390		len = put_dec(tmp, num) - tmp;
 391	}
 392
 393	if (len > size || width > size)
 394		return 0;
 395
 396	if (width > len) {
 397		width = width - len;
 398		for (idx = 0; idx < width; idx++)
 399			buf[idx] = ' ';
 400	} else {
 401		width = 0;
 402	}
 403
 404	for (idx = 0; idx < len; ++idx)
 405		buf[idx + width] = tmp[len - idx - 1];
 406
 407	return len + width;
 408}
 409
 410#define SIGN	1		/* unsigned/signed, must be 1 */
 411#define LEFT	2		/* left justified */
 412#define PLUS	4		/* show plus */
 413#define SPACE	8		/* space if plus */
 414#define ZEROPAD	16		/* pad with zero, must be 16 == '0' - ' ' */
 415#define SMALL	32		/* use lowercase in hex (must be 32 == 0x20) */
 416#define SPECIAL	64		/* prefix hex with "0x", octal with "0" */
 417
 418static_assert(SIGN == 1);
 419static_assert(ZEROPAD == ('0' - ' '));
 420static_assert(SMALL == ('a' ^ 'A'));
 421
 422enum format_type {
 423	FORMAT_TYPE_NONE, /* Just a string part */
 424	FORMAT_TYPE_WIDTH,
 425	FORMAT_TYPE_PRECISION,
 426	FORMAT_TYPE_CHAR,
 427	FORMAT_TYPE_STR,
 428	FORMAT_TYPE_PTR,
 429	FORMAT_TYPE_PERCENT_CHAR,
 430	FORMAT_TYPE_INVALID,
 431	FORMAT_TYPE_LONG_LONG,
 432	FORMAT_TYPE_ULONG,
 433	FORMAT_TYPE_LONG,
 434	FORMAT_TYPE_UBYTE,
 435	FORMAT_TYPE_BYTE,
 436	FORMAT_TYPE_USHORT,
 437	FORMAT_TYPE_SHORT,
 438	FORMAT_TYPE_UINT,
 439	FORMAT_TYPE_INT,
 440	FORMAT_TYPE_SIZE_T,
 441	FORMAT_TYPE_PTRDIFF
 442};
 443
 444struct printf_spec {
 445	unsigned int	type:8;		/* format_type enum */
 446	signed int	field_width:24;	/* width of output field */
 447	unsigned int	flags:8;	/* flags to number() */
 448	unsigned int	base:8;		/* number base, 8, 10 or 16 only */
 449	signed int	precision:16;	/* # of digits/chars */
 450} __packed;
 451static_assert(sizeof(struct printf_spec) == 8);
 452
 453#define FIELD_WIDTH_MAX ((1 << 23) - 1)
 454#define PRECISION_MAX ((1 << 15) - 1)
 455
 456static noinline_for_stack
 457char *number(char *buf, char *end, unsigned long long num,
 458	     struct printf_spec spec)
 459{
 460	/* put_dec requires 2-byte alignment of the buffer. */
 461	char tmp[3 * sizeof(num)] __aligned(2);
 
 
 462	char sign;
 463	char locase;
 464	int need_pfx = ((spec.flags & SPECIAL) && spec.base != 10);
 465	int i;
 466	bool is_zero = num == 0LL;
 467	int field_width = spec.field_width;
 468	int precision = spec.precision;
 469
 470	/* locase = 0 or 0x20. ORing digits or letters with 'locase'
 471	 * produces same digits or (maybe lowercased) letters */
 472	locase = (spec.flags & SMALL);
 473	if (spec.flags & LEFT)
 474		spec.flags &= ~ZEROPAD;
 475	sign = 0;
 476	if (spec.flags & SIGN) {
 477		if ((signed long long)num < 0) {
 478			sign = '-';
 479			num = -(signed long long)num;
 480			field_width--;
 481		} else if (spec.flags & PLUS) {
 482			sign = '+';
 483			field_width--;
 484		} else if (spec.flags & SPACE) {
 485			sign = ' ';
 486			field_width--;
 487		}
 488	}
 489	if (need_pfx) {
 490		if (spec.base == 16)
 491			field_width -= 2;
 492		else if (!is_zero)
 493			field_width--;
 494	}
 495
 496	/* generate full string in tmp[], in reverse order */
 497	i = 0;
 498	if (num < spec.base)
 499		tmp[i++] = hex_asc_upper[num] | locase;
 
 
 
 
 
 500	else if (spec.base != 10) { /* 8 or 16 */
 501		int mask = spec.base - 1;
 502		int shift = 3;
 503
 504		if (spec.base == 16)
 505			shift = 4;
 506		do {
 507			tmp[i++] = (hex_asc_upper[((unsigned char)num) & mask] | locase);
 508			num >>= shift;
 509		} while (num);
 510	} else { /* base 10 */
 511		i = put_dec(tmp, num) - tmp;
 512	}
 513
 514	/* printing 100 using %2d gives "100", not "00" */
 515	if (i > precision)
 516		precision = i;
 517	/* leading space padding */
 518	field_width -= precision;
 519	if (!(spec.flags & (ZEROPAD | LEFT))) {
 520		while (--field_width >= 0) {
 521			if (buf < end)
 522				*buf = ' ';
 523			++buf;
 524		}
 525	}
 526	/* sign */
 527	if (sign) {
 528		if (buf < end)
 529			*buf = sign;
 530		++buf;
 531	}
 532	/* "0x" / "0" prefix */
 533	if (need_pfx) {
 534		if (spec.base == 16 || !is_zero) {
 535			if (buf < end)
 536				*buf = '0';
 537			++buf;
 538		}
 539		if (spec.base == 16) {
 540			if (buf < end)
 541				*buf = ('X' | locase);
 542			++buf;
 543		}
 544	}
 545	/* zero or space padding */
 546	if (!(spec.flags & LEFT)) {
 547		char c = ' ' + (spec.flags & ZEROPAD);
 548
 549		while (--field_width >= 0) {
 550			if (buf < end)
 551				*buf = c;
 552			++buf;
 553		}
 554	}
 555	/* hmm even more zero padding? */
 556	while (i <= --precision) {
 557		if (buf < end)
 558			*buf = '0';
 559		++buf;
 560	}
 561	/* actual digits of result */
 562	while (--i >= 0) {
 563		if (buf < end)
 564			*buf = tmp[i];
 565		++buf;
 566	}
 567	/* trailing space padding */
 568	while (--field_width >= 0) {
 569		if (buf < end)
 570			*buf = ' ';
 571		++buf;
 572	}
 573
 574	return buf;
 575}
 576
 577static noinline_for_stack
 578char *special_hex_number(char *buf, char *end, unsigned long long num, int size)
 579{
 580	struct printf_spec spec;
 581
 582	spec.type = FORMAT_TYPE_PTR;
 583	spec.field_width = 2 + 2 * size;	/* 0x + hex */
 584	spec.flags = SPECIAL | SMALL | ZEROPAD;
 585	spec.base = 16;
 586	spec.precision = -1;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 587
 588	return number(buf, end, num, spec);
 589}
 590
 591static void move_right(char *buf, char *end, unsigned len, unsigned spaces)
 592{
 593	size_t size;
 594	if (buf >= end)	/* nowhere to put anything */
 595		return;
 596	size = end - buf;
 597	if (size <= spaces) {
 598		memset(buf, ' ', size);
 599		return;
 600	}
 601	if (len) {
 602		if (len > size - spaces)
 603			len = size - spaces;
 604		memmove(buf + spaces, buf, len);
 605	}
 606	memset(buf, ' ', spaces);
 607}
 608
 609/*
 610 * Handle field width padding for a string.
 611 * @buf: current buffer position
 612 * @n: length of string
 613 * @end: end of output buffer
 614 * @spec: for field width and flags
 615 * Returns: new buffer position after padding.
 616 */
 617static noinline_for_stack
 618char *widen_string(char *buf, int n, char *end, struct printf_spec spec)
 619{
 620	unsigned spaces;
 621
 622	if (likely(n >= spec.field_width))
 623		return buf;
 624	/* we want to pad the sucker */
 625	spaces = spec.field_width - n;
 626	if (!(spec.flags & LEFT)) {
 627		move_right(buf - n, end, n, spaces);
 628		return buf + spaces;
 629	}
 630	while (spaces--) {
 631		if (buf < end)
 632			*buf = ' ';
 633		++buf;
 634	}
 635	return buf;
 636}
 637
 638/* Handle string from a well known address. */
 639static char *string_nocheck(char *buf, char *end, const char *s,
 640			    struct printf_spec spec)
 641{
 642	int len = 0;
 643	int lim = spec.precision;
 644
 645	while (lim--) {
 646		char c = *s++;
 647		if (!c)
 648			break;
 649		if (buf < end)
 650			*buf = c;
 651		++buf;
 652		++len;
 653	}
 654	return widen_string(buf, len, end, spec);
 655}
 656
 657static char *err_ptr(char *buf, char *end, void *ptr,
 658		     struct printf_spec spec)
 659{
 660	int err = PTR_ERR(ptr);
 661	const char *sym = errname(err);
 662
 663	if (sym)
 664		return string_nocheck(buf, end, sym, spec);
 665
 666	/*
 667	 * Somebody passed ERR_PTR(-1234) or some other non-existing
 668	 * Efoo - or perhaps CONFIG_SYMBOLIC_ERRNAME=n. Fall back to
 669	 * printing it as its decimal representation.
 670	 */
 671	spec.flags |= SIGN;
 672	spec.base = 10;
 673	return number(buf, end, err, spec);
 674}
 675
 676/* Be careful: error messages must fit into the given buffer. */
 677static char *error_string(char *buf, char *end, const char *s,
 678			  struct printf_spec spec)
 679{
 680	/*
 681	 * Hard limit to avoid a completely insane messages. It actually
 682	 * works pretty well because most error messages are in
 683	 * the many pointer format modifiers.
 684	 */
 685	if (spec.precision == -1)
 686		spec.precision = 2 * sizeof(void *);
 687
 688	return string_nocheck(buf, end, s, spec);
 689}
 690
 691/*
 692 * Do not call any complex external code here. Nested printk()/vsprintf()
 693 * might cause infinite loops. Failures might break printk() and would
 694 * be hard to debug.
 695 */
 696static const char *check_pointer_msg(const void *ptr)
 697{
 698	if (!ptr)
 699		return "(null)";
 700
 701	if ((unsigned long)ptr < PAGE_SIZE || IS_ERR_VALUE(ptr))
 702		return "(efault)";
 703
 704	return NULL;
 705}
 706
 707static int check_pointer(char **buf, char *end, const void *ptr,
 708			 struct printf_spec spec)
 709{
 710	const char *err_msg;
 711
 712	err_msg = check_pointer_msg(ptr);
 713	if (err_msg) {
 714		*buf = error_string(*buf, end, err_msg, spec);
 715		return -EFAULT;
 716	}
 717
 718	return 0;
 719}
 720
 721static noinline_for_stack
 722char *string(char *buf, char *end, const char *s,
 723	     struct printf_spec spec)
 724{
 725	if (check_pointer(&buf, end, s, spec))
 726		return buf;
 727
 728	return string_nocheck(buf, end, s, spec);
 729}
 730
 731static char *pointer_string(char *buf, char *end,
 732			    const void *ptr,
 733			    struct printf_spec spec)
 734{
 735	spec.base = 16;
 736	spec.flags |= SMALL;
 737	if (spec.field_width == -1) {
 738		spec.field_width = 2 * sizeof(ptr);
 739		spec.flags |= ZEROPAD;
 740	}
 741
 742	return number(buf, end, (unsigned long int)ptr, spec);
 743}
 744
 745/* Make pointers available for printing early in the boot sequence. */
 746static int debug_boot_weak_hash __ro_after_init;
 747
 748static int __init debug_boot_weak_hash_enable(char *str)
 749{
 750	debug_boot_weak_hash = 1;
 751	pr_info("debug_boot_weak_hash enabled\n");
 752	return 0;
 753}
 754early_param("debug_boot_weak_hash", debug_boot_weak_hash_enable);
 755
 756static bool filled_random_ptr_key __read_mostly;
 757static siphash_key_t ptr_key __read_mostly;
 758
 759static int fill_ptr_key(struct notifier_block *nb, unsigned long action, void *data)
 760{
 761	get_random_bytes(&ptr_key, sizeof(ptr_key));
 762
 763	/* Pairs with smp_rmb() before reading ptr_key. */
 764	smp_wmb();
 765	WRITE_ONCE(filled_random_ptr_key, true);
 766	return NOTIFY_DONE;
 767}
 768
 769static int __init vsprintf_init_hashval(void)
 770{
 771	static struct notifier_block fill_ptr_key_nb = { .notifier_call = fill_ptr_key };
 772	execute_with_initialized_rng(&fill_ptr_key_nb);
 773	return 0;
 774}
 775subsys_initcall(vsprintf_init_hashval)
 776
 777/* Maps a pointer to a 32 bit unique identifier. */
 778static inline int __ptr_to_hashval(const void *ptr, unsigned long *hashval_out)
 779{
 780	unsigned long hashval;
 781
 782	if (!READ_ONCE(filled_random_ptr_key))
 783		return -EBUSY;
 784
 785	/* Pairs with smp_wmb() after writing ptr_key. */
 786	smp_rmb();
 787
 788#ifdef CONFIG_64BIT
 789	hashval = (unsigned long)siphash_1u64((u64)ptr, &ptr_key);
 790	/*
 791	 * Mask off the first 32 bits, this makes explicit that we have
 792	 * modified the address (and 32 bits is plenty for a unique ID).
 793	 */
 794	hashval = hashval & 0xffffffff;
 795#else
 796	hashval = (unsigned long)siphash_1u32((u32)ptr, &ptr_key);
 797#endif
 798	*hashval_out = hashval;
 799	return 0;
 800}
 801
 802int ptr_to_hashval(const void *ptr, unsigned long *hashval_out)
 803{
 804	return __ptr_to_hashval(ptr, hashval_out);
 805}
 806
 807static char *ptr_to_id(char *buf, char *end, const void *ptr,
 808		       struct printf_spec spec)
 809{
 810	const char *str = sizeof(ptr) == 8 ? "(____ptrval____)" : "(ptrval)";
 811	unsigned long hashval;
 812	int ret;
 813
 814	/*
 815	 * Print the real pointer value for NULL and error pointers,
 816	 * as they are not actual addresses.
 817	 */
 818	if (IS_ERR_OR_NULL(ptr))
 819		return pointer_string(buf, end, ptr, spec);
 820
 821	/* When debugging early boot use non-cryptographically secure hash. */
 822	if (unlikely(debug_boot_weak_hash)) {
 823		hashval = hash_long((unsigned long)ptr, 32);
 824		return pointer_string(buf, end, (const void *)hashval, spec);
 825	}
 826
 827	ret = __ptr_to_hashval(ptr, &hashval);
 828	if (ret) {
 829		spec.field_width = 2 * sizeof(ptr);
 830		/* string length must be less than default_width */
 831		return error_string(buf, end, str, spec);
 832	}
 833
 834	return pointer_string(buf, end, (const void *)hashval, spec);
 835}
 836
 837static char *default_pointer(char *buf, char *end, const void *ptr,
 838			     struct printf_spec spec)
 839{
 840	/*
 841	 * default is to _not_ leak addresses, so hash before printing,
 842	 * unless no_hash_pointers is specified on the command line.
 843	 */
 844	if (unlikely(no_hash_pointers))
 845		return pointer_string(buf, end, ptr, spec);
 846
 847	return ptr_to_id(buf, end, ptr, spec);
 848}
 849
 850int kptr_restrict __read_mostly;
 851
 852static noinline_for_stack
 853char *restricted_pointer(char *buf, char *end, const void *ptr,
 854			 struct printf_spec spec)
 855{
 856	switch (kptr_restrict) {
 857	case 0:
 858		/* Handle as %p, hash and do _not_ leak addresses. */
 859		return default_pointer(buf, end, ptr, spec);
 860	case 1: {
 861		const struct cred *cred;
 862
 863		/*
 864		 * kptr_restrict==1 cannot be used in IRQ context
 865		 * because its test for CAP_SYSLOG would be meaningless.
 866		 */
 867		if (in_hardirq() || in_serving_softirq() || in_nmi()) {
 868			if (spec.field_width == -1)
 869				spec.field_width = 2 * sizeof(ptr);
 870			return error_string(buf, end, "pK-error", spec);
 871		}
 872
 873		/*
 874		 * Only print the real pointer value if the current
 875		 * process has CAP_SYSLOG and is running with the
 876		 * same credentials it started with. This is because
 877		 * access to files is checked at open() time, but %pK
 878		 * checks permission at read() time. We don't want to
 879		 * leak pointer values if a binary opens a file using
 880		 * %pK and then elevates privileges before reading it.
 881		 */
 882		cred = current_cred();
 883		if (!has_capability_noaudit(current, CAP_SYSLOG) ||
 884		    !uid_eq(cred->euid, cred->uid) ||
 885		    !gid_eq(cred->egid, cred->gid))
 886			ptr = NULL;
 887		break;
 888	}
 889	case 2:
 890	default:
 891		/* Always print 0's for %pK */
 892		ptr = NULL;
 893		break;
 894	}
 895
 896	return pointer_string(buf, end, ptr, spec);
 897}
 898
 899static noinline_for_stack
 900char *dentry_name(char *buf, char *end, const struct dentry *d, struct printf_spec spec,
 901		  const char *fmt)
 902{
 903	const char *array[4], *s;
 904	const struct dentry *p;
 905	int depth;
 906	int i, n;
 907
 908	switch (fmt[1]) {
 909		case '2': case '3': case '4':
 910			depth = fmt[1] - '0';
 911			break;
 912		default:
 913			depth = 1;
 914	}
 915
 916	rcu_read_lock();
 917	for (i = 0; i < depth; i++, d = p) {
 918		if (check_pointer(&buf, end, d, spec)) {
 919			rcu_read_unlock();
 920			return buf;
 921		}
 922
 923		p = READ_ONCE(d->d_parent);
 924		array[i] = READ_ONCE(d->d_name.name);
 925		if (p == d) {
 926			if (i)
 927				array[i] = "";
 928			i++;
 929			break;
 930		}
 931	}
 932	s = array[--i];
 933	for (n = 0; n != spec.precision; n++, buf++) {
 934		char c = *s++;
 935		if (!c) {
 936			if (!i)
 937				break;
 938			c = '/';
 939			s = array[--i];
 940		}
 941		if (buf < end)
 942			*buf = c;
 943	}
 944	rcu_read_unlock();
 945	return widen_string(buf, n, end, spec);
 946}
 947
 948static noinline_for_stack
 949char *file_dentry_name(char *buf, char *end, const struct file *f,
 950			struct printf_spec spec, const char *fmt)
 951{
 952	if (check_pointer(&buf, end, f, spec))
 953		return buf;
 954
 955	return dentry_name(buf, end, f->f_path.dentry, spec, fmt);
 956}
 957#ifdef CONFIG_BLOCK
 958static noinline_for_stack
 959char *bdev_name(char *buf, char *end, struct block_device *bdev,
 960		struct printf_spec spec, const char *fmt)
 961{
 962	struct gendisk *hd;
 963
 964	if (check_pointer(&buf, end, bdev, spec))
 965		return buf;
 966
 967	hd = bdev->bd_disk;
 968	buf = string(buf, end, hd->disk_name, spec);
 969	if (bdev_is_partition(bdev)) {
 970		if (isdigit(hd->disk_name[strlen(hd->disk_name)-1])) {
 971			if (buf < end)
 972				*buf = 'p';
 973			buf++;
 974		}
 975		buf = number(buf, end, bdev_partno(bdev), spec);
 976	}
 977	return buf;
 978}
 979#endif
 980
 981static noinline_for_stack
 982char *symbol_string(char *buf, char *end, void *ptr,
 983		    struct printf_spec spec, const char *fmt)
 984{
 985	unsigned long value;
 986#ifdef CONFIG_KALLSYMS
 987	char sym[KSYM_SYMBOL_LEN];
 988#endif
 989
 990	if (fmt[1] == 'R')
 991		ptr = __builtin_extract_return_addr(ptr);
 992	value = (unsigned long)ptr;
 993
 994#ifdef CONFIG_KALLSYMS
 995	if (*fmt == 'B' && fmt[1] == 'b')
 996		sprint_backtrace_build_id(sym, value);
 997	else if (*fmt == 'B')
 998		sprint_backtrace(sym, value);
 999	else if (*fmt == 'S' && (fmt[1] == 'b' || (fmt[1] == 'R' && fmt[2] == 'b')))
1000		sprint_symbol_build_id(sym, value);
1001	else if (*fmt != 's')
1002		sprint_symbol(sym, value);
1003	else
1004		sprint_symbol_no_offset(sym, value);
1005
1006	return string_nocheck(buf, end, sym, spec);
1007#else
1008	return special_hex_number(buf, end, value, sizeof(void *));
 
 
 
 
1009#endif
1010}
1011
1012static const struct printf_spec default_str_spec = {
1013	.field_width = -1,
1014	.precision = -1,
1015};
1016
1017static const struct printf_spec default_flag_spec = {
1018	.base = 16,
1019	.precision = -1,
1020	.flags = SPECIAL | SMALL,
1021};
1022
1023static const struct printf_spec default_dec_spec = {
1024	.base = 10,
1025	.precision = -1,
1026};
1027
1028static const struct printf_spec default_dec02_spec = {
1029	.base = 10,
1030	.field_width = 2,
1031	.precision = -1,
1032	.flags = ZEROPAD,
1033};
1034
1035static const struct printf_spec default_dec04_spec = {
1036	.base = 10,
1037	.field_width = 4,
1038	.precision = -1,
1039	.flags = ZEROPAD,
1040};
1041
1042static noinline_for_stack
1043char *hex_range(char *buf, char *end, u64 start_val, u64 end_val,
1044		struct printf_spec spec)
1045{
1046	buf = number(buf, end, start_val, spec);
1047	if (start_val == end_val)
1048		return buf;
1049
1050	if (buf < end)
1051		*buf = '-';
1052	++buf;
1053	return number(buf, end, end_val, spec);
1054}
1055
1056static noinline_for_stack
1057char *resource_string(char *buf, char *end, struct resource *res,
1058		      struct printf_spec spec, const char *fmt)
1059{
1060#ifndef IO_RSRC_PRINTK_SIZE
1061#define IO_RSRC_PRINTK_SIZE	6
1062#endif
1063
1064#ifndef MEM_RSRC_PRINTK_SIZE
1065#define MEM_RSRC_PRINTK_SIZE	10
1066#endif
1067	static const struct printf_spec io_spec = {
1068		.base = 16,
1069		.field_width = IO_RSRC_PRINTK_SIZE,
1070		.precision = -1,
1071		.flags = SPECIAL | SMALL | ZEROPAD,
1072	};
1073	static const struct printf_spec mem_spec = {
1074		.base = 16,
1075		.field_width = MEM_RSRC_PRINTK_SIZE,
1076		.precision = -1,
1077		.flags = SPECIAL | SMALL | ZEROPAD,
1078	};
1079	static const struct printf_spec bus_spec = {
1080		.base = 16,
1081		.field_width = 2,
1082		.precision = -1,
1083		.flags = SMALL | ZEROPAD,
1084	};
 
 
 
 
 
1085	static const struct printf_spec str_spec = {
1086		.field_width = -1,
1087		.precision = 10,
1088		.flags = LEFT,
1089	};
 
 
 
 
 
1090
1091	/* 32-bit res (sizeof==4): 10 chars in dec, 10 in hex ("0x" + 8)
1092	 * 64-bit res (sizeof==8): 20 chars in dec, 18 in hex ("0x" + 16) */
1093#define RSRC_BUF_SIZE		((2 * sizeof(resource_size_t)) + 4)
1094#define FLAG_BUF_SIZE		(2 * sizeof(res->flags))
1095#define DECODED_BUF_SIZE	sizeof("[mem - 64bit pref window disabled]")
1096#define RAW_BUF_SIZE		sizeof("[mem - flags 0x]")
1097	char sym[MAX(2*RSRC_BUF_SIZE + DECODED_BUF_SIZE,
1098		     2*RSRC_BUF_SIZE + FLAG_BUF_SIZE + RAW_BUF_SIZE)];
1099
1100	char *p = sym, *pend = sym + sizeof(sym);
1101	int decode = (fmt[0] == 'R') ? 1 : 0;
1102	const struct printf_spec *specp;
1103
1104	if (check_pointer(&buf, end, res, spec))
1105		return buf;
1106
1107	*p++ = '[';
1108	if (res->flags & IORESOURCE_IO) {
1109		p = string_nocheck(p, pend, "io  ", str_spec);
1110		specp = &io_spec;
1111	} else if (res->flags & IORESOURCE_MEM) {
1112		p = string_nocheck(p, pend, "mem ", str_spec);
1113		specp = &mem_spec;
1114	} else if (res->flags & IORESOURCE_IRQ) {
1115		p = string_nocheck(p, pend, "irq ", str_spec);
1116		specp = &default_dec_spec;
1117	} else if (res->flags & IORESOURCE_DMA) {
1118		p = string_nocheck(p, pend, "dma ", str_spec);
1119		specp = &default_dec_spec;
1120	} else if (res->flags & IORESOURCE_BUS) {
1121		p = string_nocheck(p, pend, "bus ", str_spec);
1122		specp = &bus_spec;
1123	} else {
1124		p = string_nocheck(p, pend, "??? ", str_spec);
1125		specp = &mem_spec;
1126		decode = 0;
1127	}
1128	if (decode && res->flags & IORESOURCE_UNSET) {
1129		p = string_nocheck(p, pend, "size ", str_spec);
1130		p = number(p, pend, resource_size(res), *specp);
1131	} else {
1132		p = hex_range(p, pend, res->start, res->end, *specp);
 
 
 
 
1133	}
1134	if (decode) {
1135		if (res->flags & IORESOURCE_MEM_64)
1136			p = string_nocheck(p, pend, " 64bit", str_spec);
1137		if (res->flags & IORESOURCE_PREFETCH)
1138			p = string_nocheck(p, pend, " pref", str_spec);
1139		if (res->flags & IORESOURCE_WINDOW)
1140			p = string_nocheck(p, pend, " window", str_spec);
1141		if (res->flags & IORESOURCE_DISABLED)
1142			p = string_nocheck(p, pend, " disabled", str_spec);
1143	} else {
1144		p = string_nocheck(p, pend, " flags ", str_spec);
1145		p = number(p, pend, res->flags, default_flag_spec);
1146	}
1147	*p++ = ']';
1148	*p = '\0';
1149
1150	return string_nocheck(buf, end, sym, spec);
1151}
1152
1153static noinline_for_stack
1154char *range_string(char *buf, char *end, const struct range *range,
1155		   struct printf_spec spec, const char *fmt)
1156{
1157	char sym[sizeof("[range 0x0123456789abcdef-0x0123456789abcdef]")];
1158	char *p = sym, *pend = sym + sizeof(sym);
1159
1160	struct printf_spec range_spec = {
1161		.field_width = 2 + 2 * sizeof(range->start), /* 0x + 2 * 8 */
1162		.flags = SPECIAL | SMALL | ZEROPAD,
1163		.base = 16,
1164		.precision = -1,
1165	};
1166
1167	if (check_pointer(&buf, end, range, spec))
1168		return buf;
1169
1170	p = string_nocheck(p, pend, "[range ", default_str_spec);
1171	p = hex_range(p, pend, range->start, range->end, range_spec);
1172	*p++ = ']';
1173	*p = '\0';
1174
1175	return string_nocheck(buf, end, sym, spec);
1176}
1177
1178static noinline_for_stack
1179char *hex_string(char *buf, char *end, u8 *addr, struct printf_spec spec,
1180		 const char *fmt)
1181{
1182	int i, len = 1;		/* if we pass '%ph[CDN]', field width remains
1183				   negative value, fallback to the default */
1184	char separator;
1185
1186	if (spec.field_width == 0)
1187		/* nothing to print */
1188		return buf;
1189
1190	if (check_pointer(&buf, end, addr, spec))
1191		return buf;
 
1192
1193	switch (fmt[1]) {
1194	case 'C':
1195		separator = ':';
1196		break;
1197	case 'D':
1198		separator = '-';
1199		break;
1200	case 'N':
1201		separator = 0;
1202		break;
1203	default:
1204		separator = ' ';
1205		break;
1206	}
1207
1208	if (spec.field_width > 0)
1209		len = min_t(int, spec.field_width, 64);
1210
1211	for (i = 0; i < len; ++i) {
1212		if (buf < end)
1213			*buf = hex_asc_hi(addr[i]);
1214		++buf;
1215		if (buf < end)
1216			*buf = hex_asc_lo(addr[i]);
1217		++buf;
1218
1219		if (separator && i != len - 1) {
1220			if (buf < end)
1221				*buf = separator;
1222			++buf;
1223		}
1224	}
1225
1226	return buf;
1227}
1228
1229static noinline_for_stack
1230char *bitmap_string(char *buf, char *end, const unsigned long *bitmap,
1231		    struct printf_spec spec, const char *fmt)
1232{
1233	const int CHUNKSZ = 32;
1234	int nr_bits = max_t(int, spec.field_width, 0);
1235	int i, chunksz;
1236	bool first = true;
1237
1238	if (check_pointer(&buf, end, bitmap, spec))
1239		return buf;
1240
1241	/* reused to print numbers */
1242	spec = (struct printf_spec){ .flags = SMALL | ZEROPAD, .base = 16 };
1243
1244	chunksz = nr_bits & (CHUNKSZ - 1);
1245	if (chunksz == 0)
1246		chunksz = CHUNKSZ;
1247
1248	i = ALIGN(nr_bits, CHUNKSZ) - CHUNKSZ;
1249	for (; i >= 0; i -= CHUNKSZ) {
1250		u32 chunkmask, val;
1251		int word, bit;
1252
1253		chunkmask = ((1ULL << chunksz) - 1);
1254		word = i / BITS_PER_LONG;
1255		bit = i % BITS_PER_LONG;
1256		val = (bitmap[word] >> bit) & chunkmask;
1257
1258		if (!first) {
1259			if (buf < end)
1260				*buf = ',';
1261			buf++;
1262		}
1263		first = false;
1264
1265		spec.field_width = DIV_ROUND_UP(chunksz, 4);
1266		buf = number(buf, end, val, spec);
1267
1268		chunksz = CHUNKSZ;
1269	}
1270	return buf;
1271}
1272
1273static noinline_for_stack
1274char *bitmap_list_string(char *buf, char *end, const unsigned long *bitmap,
1275			 struct printf_spec spec, const char *fmt)
1276{
1277	int nr_bits = max_t(int, spec.field_width, 0);
1278	bool first = true;
1279	int rbot, rtop;
1280
1281	if (check_pointer(&buf, end, bitmap, spec))
1282		return buf;
1283
1284	for_each_set_bitrange(rbot, rtop, bitmap, nr_bits) {
1285		if (!first) {
1286			if (buf < end)
1287				*buf = ',';
1288			buf++;
1289		}
1290		first = false;
1291
1292		buf = number(buf, end, rbot, default_dec_spec);
1293		if (rtop == rbot + 1)
1294			continue;
1295
1296		if (buf < end)
1297			*buf = '-';
1298		buf = number(++buf, end, rtop - 1, default_dec_spec);
1299	}
1300	return buf;
1301}
1302
1303static noinline_for_stack
1304char *mac_address_string(char *buf, char *end, u8 *addr,
1305			 struct printf_spec spec, const char *fmt)
1306{
1307	char mac_addr[sizeof("xx:xx:xx:xx:xx:xx")];
1308	char *p = mac_addr;
1309	int i;
1310	char separator;
1311	bool reversed = false;
1312
1313	if (check_pointer(&buf, end, addr, spec))
1314		return buf;
1315
1316	switch (fmt[1]) {
1317	case 'F':
1318		separator = '-';
1319		break;
1320
1321	case 'R':
1322		reversed = true;
1323		fallthrough;
1324
1325	default:
1326		separator = ':';
1327		break;
1328	}
1329
1330	for (i = 0; i < 6; i++) {
1331		if (reversed)
1332			p = hex_byte_pack(p, addr[5 - i]);
1333		else
1334			p = hex_byte_pack(p, addr[i]);
1335
1336		if (fmt[0] == 'M' && i != 5)
1337			*p++ = separator;
1338	}
1339	*p = '\0';
1340
1341	return string_nocheck(buf, end, mac_addr, spec);
1342}
1343
1344static noinline_for_stack
1345char *ip4_string(char *p, const u8 *addr, const char *fmt)
1346{
1347	int i;
1348	bool leading_zeros = (fmt[0] == 'i');
1349	int index;
1350	int step;
1351
1352	switch (fmt[2]) {
1353	case 'h':
1354#ifdef __BIG_ENDIAN
1355		index = 0;
1356		step = 1;
1357#else
1358		index = 3;
1359		step = -1;
1360#endif
1361		break;
1362	case 'l':
1363		index = 3;
1364		step = -1;
1365		break;
1366	case 'n':
1367	case 'b':
1368	default:
1369		index = 0;
1370		step = 1;
1371		break;
1372	}
1373	for (i = 0; i < 4; i++) {
1374		char temp[4] __aligned(2);	/* hold each IP quad in reverse order */
1375		int digits = put_dec_trunc8(temp, addr[index]) - temp;
1376		if (leading_zeros) {
1377			if (digits < 3)
1378				*p++ = '0';
1379			if (digits < 2)
1380				*p++ = '0';
1381		}
1382		/* reverse the digits in the quad */
1383		while (digits--)
1384			*p++ = temp[digits];
1385		if (i < 3)
1386			*p++ = '.';
1387		index += step;
1388	}
1389	*p = '\0';
1390
1391	return p;
1392}
1393
1394static noinline_for_stack
1395char *ip6_compressed_string(char *p, const char *addr)
1396{
1397	int i, j, range;
1398	unsigned char zerolength[8];
1399	int longest = 1;
1400	int colonpos = -1;
1401	u16 word;
1402	u8 hi, lo;
1403	bool needcolon = false;
1404	bool useIPv4;
1405	struct in6_addr in6;
1406
1407	memcpy(&in6, addr, sizeof(struct in6_addr));
1408
1409	useIPv4 = ipv6_addr_v4mapped(&in6) || ipv6_addr_is_isatap(&in6);
1410
1411	memset(zerolength, 0, sizeof(zerolength));
1412
1413	if (useIPv4)
1414		range = 6;
1415	else
1416		range = 8;
1417
1418	/* find position of longest 0 run */
1419	for (i = 0; i < range; i++) {
1420		for (j = i; j < range; j++) {
1421			if (in6.s6_addr16[j] != 0)
1422				break;
1423			zerolength[i]++;
1424		}
1425	}
1426	for (i = 0; i < range; i++) {
1427		if (zerolength[i] > longest) {
1428			longest = zerolength[i];
1429			colonpos = i;
1430		}
1431	}
1432	if (longest == 1)		/* don't compress a single 0 */
1433		colonpos = -1;
1434
1435	/* emit address */
1436	for (i = 0; i < range; i++) {
1437		if (i == colonpos) {
1438			if (needcolon || i == 0)
1439				*p++ = ':';
1440			*p++ = ':';
1441			needcolon = false;
1442			i += longest - 1;
1443			continue;
1444		}
1445		if (needcolon) {
1446			*p++ = ':';
1447			needcolon = false;
1448		}
1449		/* hex u16 without leading 0s */
1450		word = ntohs(in6.s6_addr16[i]);
1451		hi = word >> 8;
1452		lo = word & 0xff;
1453		if (hi) {
1454			if (hi > 0x0f)
1455				p = hex_byte_pack(p, hi);
1456			else
1457				*p++ = hex_asc_lo(hi);
1458			p = hex_byte_pack(p, lo);
1459		}
1460		else if (lo > 0x0f)
1461			p = hex_byte_pack(p, lo);
1462		else
1463			*p++ = hex_asc_lo(lo);
1464		needcolon = true;
1465	}
1466
1467	if (useIPv4) {
1468		if (needcolon)
1469			*p++ = ':';
1470		p = ip4_string(p, &in6.s6_addr[12], "I4");
1471	}
1472	*p = '\0';
1473
1474	return p;
1475}
1476
1477static noinline_for_stack
1478char *ip6_string(char *p, const char *addr, const char *fmt)
1479{
1480	int i;
1481
1482	for (i = 0; i < 8; i++) {
1483		p = hex_byte_pack(p, *addr++);
1484		p = hex_byte_pack(p, *addr++);
1485		if (fmt[0] == 'I' && i != 7)
1486			*p++ = ':';
1487	}
1488	*p = '\0';
1489
1490	return p;
1491}
1492
1493static noinline_for_stack
1494char *ip6_addr_string(char *buf, char *end, const u8 *addr,
1495		      struct printf_spec spec, const char *fmt)
1496{
1497	char ip6_addr[sizeof("xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255")];
1498
1499	if (fmt[0] == 'I' && fmt[2] == 'c')
1500		ip6_compressed_string(ip6_addr, addr);
1501	else
1502		ip6_string(ip6_addr, addr, fmt);
1503
1504	return string_nocheck(buf, end, ip6_addr, spec);
1505}
1506
1507static noinline_for_stack
1508char *ip4_addr_string(char *buf, char *end, const u8 *addr,
1509		      struct printf_spec spec, const char *fmt)
1510{
1511	char ip4_addr[sizeof("255.255.255.255")];
1512
1513	ip4_string(ip4_addr, addr, fmt);
1514
1515	return string_nocheck(buf, end, ip4_addr, spec);
1516}
1517
1518static noinline_for_stack
1519char *ip6_addr_string_sa(char *buf, char *end, const struct sockaddr_in6 *sa,
1520			 struct printf_spec spec, const char *fmt)
1521{
1522	bool have_p = false, have_s = false, have_f = false, have_c = false;
1523	char ip6_addr[sizeof("[xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255]") +
1524		      sizeof(":12345") + sizeof("/123456789") +
1525		      sizeof("%1234567890")];
1526	char *p = ip6_addr, *pend = ip6_addr + sizeof(ip6_addr);
1527	const u8 *addr = (const u8 *) &sa->sin6_addr;
1528	char fmt6[2] = { fmt[0], '6' };
1529	u8 off = 0;
1530
1531	fmt++;
1532	while (isalpha(*++fmt)) {
1533		switch (*fmt) {
1534		case 'p':
1535			have_p = true;
1536			break;
1537		case 'f':
1538			have_f = true;
1539			break;
1540		case 's':
1541			have_s = true;
1542			break;
1543		case 'c':
1544			have_c = true;
1545			break;
1546		}
1547	}
1548
1549	if (have_p || have_s || have_f) {
1550		*p = '[';
1551		off = 1;
1552	}
1553
1554	if (fmt6[0] == 'I' && have_c)
1555		p = ip6_compressed_string(ip6_addr + off, addr);
1556	else
1557		p = ip6_string(ip6_addr + off, addr, fmt6);
1558
1559	if (have_p || have_s || have_f)
1560		*p++ = ']';
1561
1562	if (have_p) {
1563		*p++ = ':';
1564		p = number(p, pend, ntohs(sa->sin6_port), spec);
1565	}
1566	if (have_f) {
1567		*p++ = '/';
1568		p = number(p, pend, ntohl(sa->sin6_flowinfo &
1569					  IPV6_FLOWINFO_MASK), spec);
1570	}
1571	if (have_s) {
1572		*p++ = '%';
1573		p = number(p, pend, sa->sin6_scope_id, spec);
1574	}
1575	*p = '\0';
1576
1577	return string_nocheck(buf, end, ip6_addr, spec);
1578}
1579
1580static noinline_for_stack
1581char *ip4_addr_string_sa(char *buf, char *end, const struct sockaddr_in *sa,
1582			 struct printf_spec spec, const char *fmt)
1583{
1584	bool have_p = false;
1585	char *p, ip4_addr[sizeof("255.255.255.255") + sizeof(":12345")];
1586	char *pend = ip4_addr + sizeof(ip4_addr);
1587	const u8 *addr = (const u8 *) &sa->sin_addr.s_addr;
1588	char fmt4[3] = { fmt[0], '4', 0 };
1589
1590	fmt++;
1591	while (isalpha(*++fmt)) {
1592		switch (*fmt) {
1593		case 'p':
1594			have_p = true;
1595			break;
1596		case 'h':
1597		case 'l':
1598		case 'n':
1599		case 'b':
1600			fmt4[2] = *fmt;
1601			break;
1602		}
1603	}
1604
1605	p = ip4_string(ip4_addr, addr, fmt4);
1606	if (have_p) {
1607		*p++ = ':';
1608		p = number(p, pend, ntohs(sa->sin_port), spec);
1609	}
1610	*p = '\0';
1611
1612	return string_nocheck(buf, end, ip4_addr, spec);
1613}
1614
1615static noinline_for_stack
1616char *ip_addr_string(char *buf, char *end, const void *ptr,
1617		     struct printf_spec spec, const char *fmt)
1618{
1619	char *err_fmt_msg;
1620
1621	if (check_pointer(&buf, end, ptr, spec))
1622		return buf;
1623
1624	switch (fmt[1]) {
1625	case '6':
1626		return ip6_addr_string(buf, end, ptr, spec, fmt);
1627	case '4':
1628		return ip4_addr_string(buf, end, ptr, spec, fmt);
1629	case 'S': {
1630		const union {
1631			struct sockaddr		raw;
1632			struct sockaddr_in	v4;
1633			struct sockaddr_in6	v6;
1634		} *sa = ptr;
1635
1636		switch (sa->raw.sa_family) {
1637		case AF_INET:
1638			return ip4_addr_string_sa(buf, end, &sa->v4, spec, fmt);
1639		case AF_INET6:
1640			return ip6_addr_string_sa(buf, end, &sa->v6, spec, fmt);
1641		default:
1642			return error_string(buf, end, "(einval)", spec);
1643		}}
1644	}
1645
1646	err_fmt_msg = fmt[0] == 'i' ? "(%pi?)" : "(%pI?)";
1647	return error_string(buf, end, err_fmt_msg, spec);
1648}
1649
1650static noinline_for_stack
1651char *escaped_string(char *buf, char *end, u8 *addr, struct printf_spec spec,
1652		     const char *fmt)
1653{
1654	bool found = true;
1655	int count = 1;
1656	unsigned int flags = 0;
1657	int len;
1658
1659	if (spec.field_width == 0)
1660		return buf;				/* nothing to print */
1661
1662	if (check_pointer(&buf, end, addr, spec))
1663		return buf;
1664
1665	do {
1666		switch (fmt[count++]) {
1667		case 'a':
1668			flags |= ESCAPE_ANY;
1669			break;
1670		case 'c':
1671			flags |= ESCAPE_SPECIAL;
1672			break;
1673		case 'h':
1674			flags |= ESCAPE_HEX;
1675			break;
1676		case 'n':
1677			flags |= ESCAPE_NULL;
1678			break;
1679		case 'o':
1680			flags |= ESCAPE_OCTAL;
1681			break;
1682		case 'p':
1683			flags |= ESCAPE_NP;
1684			break;
1685		case 's':
1686			flags |= ESCAPE_SPACE;
1687			break;
1688		default:
1689			found = false;
1690			break;
1691		}
1692	} while (found);
1693
1694	if (!flags)
1695		flags = ESCAPE_ANY_NP;
1696
1697	len = spec.field_width < 0 ? 1 : spec.field_width;
1698
1699	/*
1700	 * string_escape_mem() writes as many characters as it can to
1701	 * the given buffer, and returns the total size of the output
1702	 * had the buffer been big enough.
1703	 */
1704	buf += string_escape_mem(addr, len, buf, buf < end ? end - buf : 0, flags, NULL);
1705
1706	return buf;
1707}
1708
1709static char *va_format(char *buf, char *end, struct va_format *va_fmt,
1710		       struct printf_spec spec, const char *fmt)
1711{
1712	va_list va;
1713
1714	if (check_pointer(&buf, end, va_fmt, spec))
1715		return buf;
1716
1717	va_copy(va, *va_fmt->va);
1718	buf += vsnprintf(buf, end > buf ? end - buf : 0, va_fmt->fmt, va);
1719	va_end(va);
1720
1721	return buf;
1722}
1723
1724static noinline_for_stack
1725char *uuid_string(char *buf, char *end, const u8 *addr,
1726		  struct printf_spec spec, const char *fmt)
1727{
1728	char uuid[UUID_STRING_LEN + 1];
1729	char *p = uuid;
1730	int i;
1731	const u8 *index = uuid_index;
 
 
1732	bool uc = false;
1733
1734	if (check_pointer(&buf, end, addr, spec))
1735		return buf;
1736
1737	switch (*(++fmt)) {
1738	case 'L':
1739		uc = true;
1740		fallthrough;
1741	case 'l':
1742		index = guid_index;
1743		break;
1744	case 'B':
1745		uc = true;
1746		break;
1747	}
1748
1749	for (i = 0; i < 16; i++) {
1750		if (uc)
1751			p = hex_byte_pack_upper(p, addr[index[i]]);
1752		else
1753			p = hex_byte_pack(p, addr[index[i]]);
1754		switch (i) {
1755		case 3:
1756		case 5:
1757		case 7:
1758		case 9:
1759			*p++ = '-';
1760			break;
1761		}
1762	}
1763
1764	*p = 0;
1765
1766	return string_nocheck(buf, end, uuid, spec);
1767}
1768
1769static noinline_for_stack
1770char *netdev_bits(char *buf, char *end, const void *addr,
1771		  struct printf_spec spec,  const char *fmt)
1772{
1773	unsigned long long num;
1774	int size;
1775
1776	if (check_pointer(&buf, end, addr, spec))
1777		return buf;
1778
1779	switch (fmt[1]) {
1780	case 'F':
1781		num = *(const netdev_features_t *)addr;
1782		size = sizeof(netdev_features_t);
1783		break;
1784	default:
1785		return error_string(buf, end, "(%pN?)", spec);
1786	}
1787
1788	return special_hex_number(buf, end, num, size);
1789}
1790
1791static noinline_for_stack
1792char *fourcc_string(char *buf, char *end, const u32 *fourcc,
1793		    struct printf_spec spec, const char *fmt)
1794{
1795	char output[sizeof("0123 little-endian (0x01234567)")];
1796	char *p = output;
1797	unsigned int i;
1798	u32 orig, val;
1799
1800	if (fmt[1] != 'c' || fmt[2] != 'c')
1801		return error_string(buf, end, "(%p4?)", spec);
1802
1803	if (check_pointer(&buf, end, fourcc, spec))
1804		return buf;
1805
1806	orig = get_unaligned(fourcc);
1807	val = orig & ~BIT(31);
1808
1809	for (i = 0; i < sizeof(u32); i++) {
1810		unsigned char c = val >> (i * 8);
1811
1812		/* Print non-control ASCII characters as-is, dot otherwise */
1813		*p++ = isascii(c) && isprint(c) ? c : '.';
1814	}
1815
1816	*p++ = ' ';
1817	strcpy(p, orig & BIT(31) ? "big-endian" : "little-endian");
1818	p += strlen(p);
1819
1820	*p++ = ' ';
1821	*p++ = '(';
1822	p = special_hex_number(p, output + sizeof(output) - 2, orig, sizeof(u32));
1823	*p++ = ')';
1824	*p = '\0';
1825
1826	return string(buf, end, output, spec);
1827}
1828
1829static noinline_for_stack
1830char *address_val(char *buf, char *end, const void *addr,
1831		  struct printf_spec spec, const char *fmt)
1832{
1833	unsigned long long num;
1834	int size;
1835
1836	if (check_pointer(&buf, end, addr, spec))
1837		return buf;
1838
1839	switch (fmt[1]) {
1840	case 'd':
1841		num = *(const dma_addr_t *)addr;
1842		size = sizeof(dma_addr_t);
1843		break;
1844	case 'p':
1845	default:
1846		num = *(const phys_addr_t *)addr;
1847		size = sizeof(phys_addr_t);
1848		break;
1849	}
1850
1851	return special_hex_number(buf, end, num, size);
1852}
1853
1854static noinline_for_stack
1855char *date_str(char *buf, char *end, const struct rtc_time *tm, bool r)
1856{
1857	int year = tm->tm_year + (r ? 0 : 1900);
1858	int mon = tm->tm_mon + (r ? 0 : 1);
1859
1860	buf = number(buf, end, year, default_dec04_spec);
1861	if (buf < end)
1862		*buf = '-';
1863	buf++;
1864
1865	buf = number(buf, end, mon, default_dec02_spec);
1866	if (buf < end)
1867		*buf = '-';
1868	buf++;
1869
1870	return number(buf, end, tm->tm_mday, default_dec02_spec);
1871}
1872
1873static noinline_for_stack
1874char *time_str(char *buf, char *end, const struct rtc_time *tm, bool r)
1875{
1876	buf = number(buf, end, tm->tm_hour, default_dec02_spec);
1877	if (buf < end)
1878		*buf = ':';
1879	buf++;
1880
1881	buf = number(buf, end, tm->tm_min, default_dec02_spec);
1882	if (buf < end)
1883		*buf = ':';
1884	buf++;
1885
1886	return number(buf, end, tm->tm_sec, default_dec02_spec);
1887}
1888
1889static noinline_for_stack
1890char *rtc_str(char *buf, char *end, const struct rtc_time *tm,
1891	      struct printf_spec spec, const char *fmt)
1892{
1893	bool have_t = true, have_d = true;
1894	bool raw = false, iso8601_separator = true;
1895	bool found = true;
1896	int count = 2;
1897
1898	if (check_pointer(&buf, end, tm, spec))
1899		return buf;
1900
1901	switch (fmt[count]) {
1902	case 'd':
1903		have_t = false;
1904		count++;
1905		break;
1906	case 't':
1907		have_d = false;
1908		count++;
1909		break;
1910	}
1911
1912	do {
1913		switch (fmt[count++]) {
1914		case 'r':
1915			raw = true;
1916			break;
1917		case 's':
1918			iso8601_separator = false;
1919			break;
1920		default:
1921			found = false;
1922			break;
1923		}
1924	} while (found);
1925
1926	if (have_d)
1927		buf = date_str(buf, end, tm, raw);
1928	if (have_d && have_t) {
1929		if (buf < end)
1930			*buf = iso8601_separator ? 'T' : ' ';
1931		buf++;
1932	}
1933	if (have_t)
1934		buf = time_str(buf, end, tm, raw);
1935
1936	return buf;
1937}
1938
1939static noinline_for_stack
1940char *time64_str(char *buf, char *end, const time64_t time,
1941		 struct printf_spec spec, const char *fmt)
1942{
1943	struct rtc_time rtc_time;
1944	struct tm tm;
1945
1946	time64_to_tm(time, 0, &tm);
1947
1948	rtc_time.tm_sec = tm.tm_sec;
1949	rtc_time.tm_min = tm.tm_min;
1950	rtc_time.tm_hour = tm.tm_hour;
1951	rtc_time.tm_mday = tm.tm_mday;
1952	rtc_time.tm_mon = tm.tm_mon;
1953	rtc_time.tm_year = tm.tm_year;
1954	rtc_time.tm_wday = tm.tm_wday;
1955	rtc_time.tm_yday = tm.tm_yday;
1956
1957	rtc_time.tm_isdst = 0;
1958
1959	return rtc_str(buf, end, &rtc_time, spec, fmt);
1960}
1961
1962static noinline_for_stack
1963char *time_and_date(char *buf, char *end, void *ptr, struct printf_spec spec,
1964		    const char *fmt)
1965{
1966	switch (fmt[1]) {
1967	case 'R':
1968		return rtc_str(buf, end, (const struct rtc_time *)ptr, spec, fmt);
1969	case 'T':
1970		return time64_str(buf, end, *(const time64_t *)ptr, spec, fmt);
1971	default:
1972		return error_string(buf, end, "(%pt?)", spec);
1973	}
1974}
1975
1976static noinline_for_stack
1977char *clock(char *buf, char *end, struct clk *clk, struct printf_spec spec,
1978	    const char *fmt)
1979{
1980	if (!IS_ENABLED(CONFIG_HAVE_CLK))
1981		return error_string(buf, end, "(%pC?)", spec);
1982
1983	if (check_pointer(&buf, end, clk, spec))
1984		return buf;
1985
1986	switch (fmt[1]) {
1987	case 'n':
1988	default:
1989#ifdef CONFIG_COMMON_CLK
1990		return string(buf, end, __clk_get_name(clk), spec);
1991#else
1992		return ptr_to_id(buf, end, clk, spec);
1993#endif
1994	}
1995}
1996
1997static
1998char *format_flags(char *buf, char *end, unsigned long flags,
1999					const struct trace_print_flags *names)
2000{
2001	unsigned long mask;
2002
2003	for ( ; flags && names->name; names++) {
2004		mask = names->mask;
2005		if ((flags & mask) != mask)
2006			continue;
2007
2008		buf = string(buf, end, names->name, default_str_spec);
2009
2010		flags &= ~mask;
2011		if (flags) {
2012			if (buf < end)
2013				*buf = '|';
2014			buf++;
2015		}
2016	}
2017
2018	if (flags)
2019		buf = number(buf, end, flags, default_flag_spec);
2020
2021	return buf;
2022}
2023
2024struct page_flags_fields {
2025	int width;
2026	int shift;
2027	int mask;
2028	const struct printf_spec *spec;
2029	const char *name;
2030};
2031
2032static const struct page_flags_fields pff[] = {
2033	{SECTIONS_WIDTH, SECTIONS_PGSHIFT, SECTIONS_MASK,
2034	 &default_dec_spec, "section"},
2035	{NODES_WIDTH, NODES_PGSHIFT, NODES_MASK,
2036	 &default_dec_spec, "node"},
2037	{ZONES_WIDTH, ZONES_PGSHIFT, ZONES_MASK,
2038	 &default_dec_spec, "zone"},
2039	{LAST_CPUPID_WIDTH, LAST_CPUPID_PGSHIFT, LAST_CPUPID_MASK,
2040	 &default_flag_spec, "lastcpupid"},
2041	{KASAN_TAG_WIDTH, KASAN_TAG_PGSHIFT, KASAN_TAG_MASK,
2042	 &default_flag_spec, "kasantag"},
2043};
2044
2045static
2046char *format_page_flags(char *buf, char *end, unsigned long flags)
2047{
2048	unsigned long main_flags = flags & PAGEFLAGS_MASK;
2049	bool append = false;
2050	int i;
2051
2052	buf = number(buf, end, flags, default_flag_spec);
2053	if (buf < end)
2054		*buf = '(';
2055	buf++;
2056
2057	/* Page flags from the main area. */
2058	if (main_flags) {
2059		buf = format_flags(buf, end, main_flags, pageflag_names);
2060		append = true;
2061	}
2062
2063	/* Page flags from the fields area */
2064	for (i = 0; i < ARRAY_SIZE(pff); i++) {
2065		/* Skip undefined fields. */
2066		if (!pff[i].width)
2067			continue;
2068
2069		/* Format: Flag Name + '=' (equals sign) + Number + '|' (separator) */
2070		if (append) {
2071			if (buf < end)
2072				*buf = '|';
2073			buf++;
2074		}
2075
2076		buf = string(buf, end, pff[i].name, default_str_spec);
2077		if (buf < end)
2078			*buf = '=';
2079		buf++;
2080		buf = number(buf, end, (flags >> pff[i].shift) & pff[i].mask,
2081			     *pff[i].spec);
2082
2083		append = true;
2084	}
2085	if (buf < end)
2086		*buf = ')';
2087	buf++;
2088
2089	return buf;
2090}
2091
2092static noinline_for_stack
2093char *flags_string(char *buf, char *end, void *flags_ptr,
2094		   struct printf_spec spec, const char *fmt)
2095{
2096	unsigned long flags;
2097	const struct trace_print_flags *names;
2098
2099	if (check_pointer(&buf, end, flags_ptr, spec))
2100		return buf;
2101
2102	switch (fmt[1]) {
2103	case 'p':
2104		return format_page_flags(buf, end, *(unsigned long *)flags_ptr);
2105	case 'v':
2106		flags = *(unsigned long *)flags_ptr;
2107		names = vmaflag_names;
2108		break;
2109	case 'g':
2110		flags = (__force unsigned long)(*(gfp_t *)flags_ptr);
2111		names = gfpflag_names;
2112		break;
2113	default:
2114		return error_string(buf, end, "(%pG?)", spec);
2115	}
2116
2117	return format_flags(buf, end, flags, names);
2118}
2119
2120static noinline_for_stack
2121char *fwnode_full_name_string(struct fwnode_handle *fwnode, char *buf,
2122			      char *end)
2123{
2124	int depth;
2125
2126	/* Loop starting from the root node to the current node. */
2127	for (depth = fwnode_count_parents(fwnode); depth >= 0; depth--) {
2128		/*
2129		 * Only get a reference for other nodes (i.e. parent nodes).
2130		 * fwnode refcount may be 0 here.
2131		 */
2132		struct fwnode_handle *__fwnode = depth ?
2133			fwnode_get_nth_parent(fwnode, depth) : fwnode;
2134
2135		buf = string(buf, end, fwnode_get_name_prefix(__fwnode),
2136			     default_str_spec);
2137		buf = string(buf, end, fwnode_get_name(__fwnode),
2138			     default_str_spec);
2139
2140		if (depth)
2141			fwnode_handle_put(__fwnode);
2142	}
2143
2144	return buf;
2145}
2146
2147static noinline_for_stack
2148char *device_node_string(char *buf, char *end, struct device_node *dn,
2149			 struct printf_spec spec, const char *fmt)
2150{
2151	char tbuf[sizeof("xxxx") + 1];
2152	const char *p;
2153	int ret;
2154	char *buf_start = buf;
2155	struct property *prop;
2156	bool has_mult, pass;
2157
2158	struct printf_spec str_spec = spec;
2159	str_spec.field_width = -1;
2160
2161	if (fmt[0] != 'F')
2162		return error_string(buf, end, "(%pO?)", spec);
2163
2164	if (!IS_ENABLED(CONFIG_OF))
2165		return error_string(buf, end, "(%pOF?)", spec);
2166
2167	if (check_pointer(&buf, end, dn, spec))
2168		return buf;
2169
2170	/* simple case without anything any more format specifiers */
2171	fmt++;
2172	if (fmt[0] == '\0' || strcspn(fmt,"fnpPFcC") > 0)
2173		fmt = "f";
2174
2175	for (pass = false; strspn(fmt,"fnpPFcC"); fmt++, pass = true) {
2176		int precision;
2177		if (pass) {
2178			if (buf < end)
2179				*buf = ':';
2180			buf++;
2181		}
2182
2183		switch (*fmt) {
2184		case 'f':	/* full_name */
2185			buf = fwnode_full_name_string(of_fwnode_handle(dn), buf,
2186						      end);
2187			break;
2188		case 'n':	/* name */
2189			p = fwnode_get_name(of_fwnode_handle(dn));
2190			precision = str_spec.precision;
2191			str_spec.precision = strchrnul(p, '@') - p;
2192			buf = string(buf, end, p, str_spec);
2193			str_spec.precision = precision;
2194			break;
2195		case 'p':	/* phandle */
2196			buf = number(buf, end, (unsigned int)dn->phandle, default_dec_spec);
2197			break;
2198		case 'P':	/* path-spec */
2199			p = fwnode_get_name(of_fwnode_handle(dn));
2200			if (!p[1])
2201				p = "/";
2202			buf = string(buf, end, p, str_spec);
2203			break;
2204		case 'F':	/* flags */
2205			tbuf[0] = of_node_check_flag(dn, OF_DYNAMIC) ? 'D' : '-';
2206			tbuf[1] = of_node_check_flag(dn, OF_DETACHED) ? 'd' : '-';
2207			tbuf[2] = of_node_check_flag(dn, OF_POPULATED) ? 'P' : '-';
2208			tbuf[3] = of_node_check_flag(dn, OF_POPULATED_BUS) ? 'B' : '-';
2209			tbuf[4] = 0;
2210			buf = string_nocheck(buf, end, tbuf, str_spec);
2211			break;
2212		case 'c':	/* major compatible string */
2213			ret = of_property_read_string(dn, "compatible", &p);
2214			if (!ret)
2215				buf = string(buf, end, p, str_spec);
2216			break;
2217		case 'C':	/* full compatible string */
2218			has_mult = false;
2219			of_property_for_each_string(dn, "compatible", prop, p) {
2220				if (has_mult)
2221					buf = string_nocheck(buf, end, ",", str_spec);
2222				buf = string_nocheck(buf, end, "\"", str_spec);
2223				buf = string(buf, end, p, str_spec);
2224				buf = string_nocheck(buf, end, "\"", str_spec);
2225
2226				has_mult = true;
2227			}
2228			break;
2229		default:
2230			break;
2231		}
2232	}
2233
2234	return widen_string(buf, buf - buf_start, end, spec);
2235}
2236
2237static noinline_for_stack
2238char *fwnode_string(char *buf, char *end, struct fwnode_handle *fwnode,
2239		    struct printf_spec spec, const char *fmt)
2240{
2241	struct printf_spec str_spec = spec;
2242	char *buf_start = buf;
2243
2244	str_spec.field_width = -1;
2245
2246	if (*fmt != 'w')
2247		return error_string(buf, end, "(%pf?)", spec);
2248
2249	if (check_pointer(&buf, end, fwnode, spec))
2250		return buf;
2251
2252	fmt++;
2253
2254	switch (*fmt) {
2255	case 'P':	/* name */
2256		buf = string(buf, end, fwnode_get_name(fwnode), str_spec);
2257		break;
2258	case 'f':	/* full_name */
2259	default:
2260		buf = fwnode_full_name_string(fwnode, buf, end);
2261		break;
2262	}
2263
2264	return widen_string(buf, buf - buf_start, end, spec);
2265}
2266
2267static noinline_for_stack
2268char *resource_or_range(const char *fmt, char *buf, char *end, void *ptr,
2269			struct printf_spec spec)
2270{
2271	if (*fmt == 'r' && fmt[1] == 'a')
2272		return range_string(buf, end, ptr, spec, fmt);
2273	return resource_string(buf, end, ptr, spec, fmt);
2274}
2275
2276int __init no_hash_pointers_enable(char *str)
2277{
2278	if (no_hash_pointers)
2279		return 0;
2280
2281	no_hash_pointers = true;
2282
2283	pr_warn("**********************************************************\n");
2284	pr_warn("**   NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE   **\n");
2285	pr_warn("**                                                      **\n");
2286	pr_warn("** This system shows unhashed kernel memory addresses   **\n");
2287	pr_warn("** via the console, logs, and other interfaces. This    **\n");
2288	pr_warn("** might reduce the security of your system.            **\n");
2289	pr_warn("**                                                      **\n");
2290	pr_warn("** If you see this message and you are not debugging    **\n");
2291	pr_warn("** the kernel, report this immediately to your system   **\n");
2292	pr_warn("** administrator!                                       **\n");
2293	pr_warn("**                                                      **\n");
2294	pr_warn("**   NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE   **\n");
2295	pr_warn("**********************************************************\n");
2296
2297	return 0;
2298}
2299early_param("no_hash_pointers", no_hash_pointers_enable);
2300
2301/* Used for Rust formatting ('%pA'). */
2302char *rust_fmt_argument(char *buf, char *end, void *ptr);
2303
2304/*
2305 * Show a '%p' thing.  A kernel extension is that the '%p' is followed
2306 * by an extra set of alphanumeric characters that are extended format
2307 * specifiers.
2308 *
2309 * Please update scripts/checkpatch.pl when adding/removing conversion
2310 * characters.  (Search for "check for vsprintf extension").
2311 *
2312 * Right now we handle:
2313 *
2314 * - 'S' For symbolic direct pointers (or function descriptors) with offset
2315 * - 's' For symbolic direct pointers (or function descriptors) without offset
2316 * - '[Ss]R' as above with __builtin_extract_return_addr() translation
2317 * - 'S[R]b' as above with module build ID (for use in backtraces)
2318 * - '[Ff]' %pf and %pF were obsoleted and later removed in favor of
2319 *	    %ps and %pS. Be careful when re-using these specifiers.
2320 * - 'B' For backtraced symbolic direct pointers with offset
2321 * - 'Bb' as above with module build ID (for use in backtraces)
2322 * - 'R' For decoded struct resource, e.g., [mem 0x0-0x1f 64bit pref]
2323 * - 'r' For raw struct resource, e.g., [mem 0x0-0x1f flags 0x201]
2324 * - 'ra' For struct ranges, e.g., [range 0x0000000000000000 - 0x00000000000000ff]
2325 * - 'b[l]' For a bitmap, the number of bits is determined by the field
2326 *       width which must be explicitly specified either as part of the
2327 *       format string '%32b[l]' or through '%*b[l]', [l] selects
2328 *       range-list format instead of hex format
2329 * - 'M' For a 6-byte MAC address, it prints the address in the
2330 *       usual colon-separated hex notation
2331 * - 'm' For a 6-byte MAC address, it prints the hex address without colons
2332 * - 'MF' For a 6-byte MAC FDDI address, it prints the address
2333 *       with a dash-separated hex notation
2334 * - '[mM]R' For a 6-byte MAC address, Reverse order (Bluetooth)
2335 * - 'I' [46] for IPv4/IPv6 addresses printed in the usual way
2336 *       IPv4 uses dot-separated decimal without leading 0's (1.2.3.4)
2337 *       IPv6 uses colon separated network-order 16 bit hex with leading 0's
2338 *       [S][pfs]
2339 *       Generic IPv4/IPv6 address (struct sockaddr *) that falls back to
2340 *       [4] or [6] and is able to print port [p], flowinfo [f], scope [s]
2341 * - 'i' [46] for 'raw' IPv4/IPv6 addresses
2342 *       IPv6 omits the colons (01020304...0f)
2343 *       IPv4 uses dot-separated decimal with leading 0's (010.123.045.006)
2344 *       [S][pfs]
2345 *       Generic IPv4/IPv6 address (struct sockaddr *) that falls back to
2346 *       [4] or [6] and is able to print port [p], flowinfo [f], scope [s]
2347 * - '[Ii][4S][hnbl]' IPv4 addresses in host, network, big or little endian order
2348 * - 'I[6S]c' for IPv6 addresses printed as specified by
2349 *       https://tools.ietf.org/html/rfc5952
2350 * - 'E[achnops]' For an escaped buffer, where rules are defined by combination
2351 *                of the following flags (see string_escape_mem() for the
2352 *                details):
2353 *                  a - ESCAPE_ANY
2354 *                  c - ESCAPE_SPECIAL
2355 *                  h - ESCAPE_HEX
2356 *                  n - ESCAPE_NULL
2357 *                  o - ESCAPE_OCTAL
2358 *                  p - ESCAPE_NP
2359 *                  s - ESCAPE_SPACE
2360 *                By default ESCAPE_ANY_NP is used.
2361 * - 'U' For a 16 byte UUID/GUID, it prints the UUID/GUID in the form
2362 *       "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx"
2363 *       Options for %pU are:
2364 *         b big endian lower case hex (default)
2365 *         B big endian UPPER case hex
2366 *         l little endian lower case hex
2367 *         L little endian UPPER case hex
2368 *           big endian output byte order is:
2369 *             [0][1][2][3]-[4][5]-[6][7]-[8][9]-[10][11][12][13][14][15]
2370 *           little endian output byte order is:
2371 *             [3][2][1][0]-[5][4]-[7][6]-[8][9]-[10][11][12][13][14][15]
2372 * - 'V' For a struct va_format which contains a format string * and va_list *,
2373 *       call vsnprintf(->format, *->va_list).
2374 *       Implements a "recursive vsnprintf".
2375 *       Do not use this feature without some mechanism to verify the
2376 *       correctness of the format string and va_list arguments.
2377 * - 'K' For a kernel pointer that should be hidden from unprivileged users.
2378 *       Use only for procfs, sysfs and similar files, not printk(); please
2379 *       read the documentation (path below) first.
2380 * - 'NF' For a netdev_features_t
2381 * - '4cc' V4L2 or DRM FourCC code, with endianness and raw numerical value.
2382 * - 'h[CDN]' For a variable-length buffer, it prints it as a hex string with
2383 *            a certain separator (' ' by default):
2384 *              C colon
2385 *              D dash
2386 *              N no separator
2387 *            The maximum supported length is 64 bytes of the input. Consider
2388 *            to use print_hex_dump() for the larger input.
2389 * - 'a[pd]' For address types [p] phys_addr_t, [d] dma_addr_t and derivatives
2390 *           (default assumed to be phys_addr_t, passed by reference)
2391 * - 'd[234]' For a dentry name (optionally 2-4 last components)
2392 * - 'D[234]' Same as 'd' but for a struct file
2393 * - 'g' For block_device name (gendisk + partition number)
2394 * - 't[RT][dt][r][s]' For time and date as represented by:
2395 *      R    struct rtc_time
2396 *      T    time64_t
2397 * - 'C' For a clock, it prints the name (Common Clock Framework) or address
2398 *       (legacy clock framework) of the clock
2399 * - 'Cn' For a clock, it prints the name (Common Clock Framework) or address
2400 *        (legacy clock framework) of the clock
2401 * - 'G' For flags to be printed as a collection of symbolic strings that would
2402 *       construct the specific value. Supported flags given by option:
2403 *       p page flags (see struct page) given as pointer to unsigned long
2404 *       g gfp flags (GFP_* and __GFP_*) given as pointer to gfp_t
2405 *       v vma flags (VM_*) given as pointer to unsigned long
2406 * - 'OF[fnpPcCF]'  For a device tree object
2407 *                  Without any optional arguments prints the full_name
2408 *                  f device node full_name
2409 *                  n device node name
2410 *                  p device node phandle
2411 *                  P device node path spec (name + @unit)
2412 *                  F device node flags
2413 *                  c major compatible string
2414 *                  C full compatible string
2415 * - 'fw[fP]'	For a firmware node (struct fwnode_handle) pointer
2416 *		Without an option prints the full name of the node
2417 *		f full name
2418 *		P node name, including a possible unit address
2419 * - 'x' For printing the address unmodified. Equivalent to "%lx".
2420 *       Please read the documentation (path below) before using!
2421 * - '[ku]s' For a BPF/tracing related format specifier, e.g. used out of
2422 *           bpf_trace_printk() where [ku] prefix specifies either kernel (k)
2423 *           or user (u) memory to probe, and:
2424 *              s a string, equivalent to "%s" on direct vsnprintf() use
2425 *
2426 * ** When making changes please also update:
2427 *	Documentation/core-api/printk-formats.rst
2428 *
2429 * Note: The default behaviour (unadorned %p) is to hash the address,
2430 * rendering it useful as a unique identifier.
2431 *
2432 * There is also a '%pA' format specifier, but it is only intended to be used
2433 * from Rust code to format core::fmt::Arguments. Do *not* use it from C.
2434 * See rust/kernel/print.rs for details.
2435 */
2436static noinline_for_stack
2437char *pointer(const char *fmt, char *buf, char *end, void *ptr,
2438	      struct printf_spec spec)
2439{
 
 
 
 
 
 
 
 
 
 
 
 
2440	switch (*fmt) {
 
 
 
 
2441	case 'S':
2442	case 's':
2443		ptr = dereference_symbol_descriptor(ptr);
2444		fallthrough;
2445	case 'B':
2446		return symbol_string(buf, end, ptr, spec, fmt);
2447	case 'R':
2448	case 'r':
2449		return resource_or_range(fmt, buf, end, ptr, spec);
2450	case 'h':
2451		return hex_string(buf, end, ptr, spec, fmt);
2452	case 'b':
2453		switch (fmt[1]) {
2454		case 'l':
2455			return bitmap_list_string(buf, end, ptr, spec, fmt);
2456		default:
2457			return bitmap_string(buf, end, ptr, spec, fmt);
2458		}
2459	case 'M':			/* Colon separated: 00:01:02:03:04:05 */
2460	case 'm':			/* Contiguous: 000102030405 */
2461					/* [mM]F (FDDI) */
2462					/* [mM]R (Reverse order; Bluetooth) */
2463		return mac_address_string(buf, end, ptr, spec, fmt);
2464	case 'I':			/* Formatted IP supported
2465					 * 4:	1.2.3.4
2466					 * 6:	0001:0203:...:0708
2467					 * 6c:	1::708 or 1::1.2.3.4
2468					 */
2469	case 'i':			/* Contiguous:
2470					 * 4:	001.002.003.004
2471					 * 6:   000102...0f
2472					 */
2473		return ip_addr_string(buf, end, ptr, spec, fmt);
2474	case 'E':
2475		return escaped_string(buf, end, ptr, spec, fmt);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2476	case 'U':
2477		return uuid_string(buf, end, ptr, spec, fmt);
2478	case 'V':
2479		return va_format(buf, end, ptr, spec, fmt);
 
 
 
 
 
 
 
 
2480	case 'K':
2481		return restricted_pointer(buf, end, ptr, spec);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2482	case 'N':
2483		return netdev_bits(buf, end, ptr, spec, fmt);
2484	case '4':
2485		return fourcc_string(buf, end, ptr, spec, fmt);
 
 
2486	case 'a':
2487		return address_val(buf, end, ptr, spec, fmt);
2488	case 'd':
2489		return dentry_name(buf, end, ptr, spec, fmt);
2490	case 't':
2491		return time_and_date(buf, end, ptr, spec, fmt);
2492	case 'C':
2493		return clock(buf, end, ptr, spec, fmt);
2494	case 'D':
2495		return file_dentry_name(buf, end, ptr, spec, fmt);
2496#ifdef CONFIG_BLOCK
2497	case 'g':
2498		return bdev_name(buf, end, ptr, spec, fmt);
2499#endif
 
 
 
 
 
2500
2501	case 'G':
2502		return flags_string(buf, end, ptr, spec, fmt);
2503	case 'O':
2504		return device_node_string(buf, end, ptr, spec, fmt + 1);
2505	case 'f':
2506		return fwnode_string(buf, end, ptr, spec, fmt + 1);
2507	case 'A':
2508		if (!IS_ENABLED(CONFIG_RUST)) {
2509			WARN_ONCE(1, "Please remove %%pA from non-Rust code\n");
2510			return error_string(buf, end, "(%pA?)", spec);
2511		}
2512		return rust_fmt_argument(buf, end, ptr);
2513	case 'x':
2514		return pointer_string(buf, end, ptr, spec);
2515	case 'e':
2516		/* %pe with a non-ERR_PTR gets treated as plain %p */
2517		if (!IS_ERR(ptr))
2518			return default_pointer(buf, end, ptr, spec);
2519		return err_ptr(buf, end, ptr, spec);
2520	case 'u':
2521	case 'k':
2522		switch (fmt[1]) {
2523		case 's':
2524			return string(buf, end, ptr, spec);
2525		default:
2526			return error_string(buf, end, "(einval)", spec);
2527		}
2528	default:
2529		return default_pointer(buf, end, ptr, spec);
2530	}
2531}
2532
2533/*
2534 * Helper function to decode printf style format.
2535 * Each call decode a token from the format and return the
2536 * number of characters read (or likely the delta where it wants
2537 * to go on the next call).
2538 * The decoded token is returned through the parameters
2539 *
2540 * 'h', 'l', or 'L' for integer fields
2541 * 'z' support added 23/7/1999 S.H.
2542 * 'z' changed to 'Z' --davidm 1/25/99
2543 * 'Z' changed to 'z' --adobriyan 2017-01-25
2544 * 't' added for ptrdiff_t
2545 *
2546 * @fmt: the format string
2547 * @type of the token returned
2548 * @flags: various flags such as +, -, # tokens..
2549 * @field_width: overwritten width
2550 * @base: base of the number (octal, hex, ...)
2551 * @precision: precision of a number
2552 * @qualifier: qualifier of a number (long, size_t, ...)
2553 */
2554static noinline_for_stack
2555int format_decode(const char *fmt, struct printf_spec *spec)
2556{
2557	const char *start = fmt;
2558	char qualifier;
2559
2560	/* we finished early by reading the field width */
2561	if (spec->type == FORMAT_TYPE_WIDTH) {
2562		if (spec->field_width < 0) {
2563			spec->field_width = -spec->field_width;
2564			spec->flags |= LEFT;
2565		}
2566		spec->type = FORMAT_TYPE_NONE;
2567		goto precision;
2568	}
2569
2570	/* we finished early by reading the precision */
2571	if (spec->type == FORMAT_TYPE_PRECISION) {
2572		if (spec->precision < 0)
2573			spec->precision = 0;
2574
2575		spec->type = FORMAT_TYPE_NONE;
2576		goto qualifier;
2577	}
2578
2579	/* By default */
2580	spec->type = FORMAT_TYPE_NONE;
2581
2582	for (; *fmt ; ++fmt) {
2583		if (*fmt == '%')
2584			break;
2585	}
2586
2587	/* Return the current non-format string */
2588	if (fmt != start || !*fmt)
2589		return fmt - start;
2590
2591	/* Process flags */
2592	spec->flags = 0;
2593
2594	while (1) { /* this also skips first '%' */
2595		bool found = true;
2596
2597		++fmt;
2598
2599		switch (*fmt) {
2600		case '-': spec->flags |= LEFT;    break;
2601		case '+': spec->flags |= PLUS;    break;
2602		case ' ': spec->flags |= SPACE;   break;
2603		case '#': spec->flags |= SPECIAL; break;
2604		case '0': spec->flags |= ZEROPAD; break;
2605		default:  found = false;
2606		}
2607
2608		if (!found)
2609			break;
2610	}
2611
2612	/* get field width */
2613	spec->field_width = -1;
2614
2615	if (isdigit(*fmt))
2616		spec->field_width = skip_atoi(&fmt);
2617	else if (*fmt == '*') {
2618		/* it's the next argument */
2619		spec->type = FORMAT_TYPE_WIDTH;
2620		return ++fmt - start;
2621	}
2622
2623precision:
2624	/* get the precision */
2625	spec->precision = -1;
2626	if (*fmt == '.') {
2627		++fmt;
2628		if (isdigit(*fmt)) {
2629			spec->precision = skip_atoi(&fmt);
2630			if (spec->precision < 0)
2631				spec->precision = 0;
2632		} else if (*fmt == '*') {
2633			/* it's the next argument */
2634			spec->type = FORMAT_TYPE_PRECISION;
2635			return ++fmt - start;
2636		}
2637	}
2638
2639qualifier:
2640	/* get the conversion qualifier */
2641	qualifier = 0;
2642	if (*fmt == 'h' || _tolower(*fmt) == 'l' ||
2643	    *fmt == 'z' || *fmt == 't') {
2644		qualifier = *fmt++;
2645		if (unlikely(qualifier == *fmt)) {
2646			if (qualifier == 'l') {
2647				qualifier = 'L';
2648				++fmt;
2649			} else if (qualifier == 'h') {
2650				qualifier = 'H';
2651				++fmt;
2652			}
2653		}
2654	}
2655
2656	/* default base */
2657	spec->base = 10;
2658	switch (*fmt) {
2659	case 'c':
2660		spec->type = FORMAT_TYPE_CHAR;
2661		return ++fmt - start;
2662
2663	case 's':
2664		spec->type = FORMAT_TYPE_STR;
2665		return ++fmt - start;
2666
2667	case 'p':
2668		spec->type = FORMAT_TYPE_PTR;
2669		return ++fmt - start;
 
2670
2671	case '%':
2672		spec->type = FORMAT_TYPE_PERCENT_CHAR;
2673		return ++fmt - start;
2674
2675	/* integer number formats - set up the flags and "break" */
2676	case 'o':
2677		spec->base = 8;
2678		break;
2679
2680	case 'x':
2681		spec->flags |= SMALL;
2682		fallthrough;
2683
2684	case 'X':
2685		spec->base = 16;
2686		break;
2687
2688	case 'd':
2689	case 'i':
2690		spec->flags |= SIGN;
2691		break;
2692	case 'u':
2693		break;
2694
2695	case 'n':
2696		/*
2697		 * Since %n poses a greater security risk than
2698		 * utility, treat it as any other invalid or
2699		 * unsupported format specifier.
2700		 */
2701		fallthrough;
 
2702
2703	default:
2704		WARN_ONCE(1, "Please remove unsupported %%%c in format string\n", *fmt);
2705		spec->type = FORMAT_TYPE_INVALID;
2706		return fmt - start;
2707	}
2708
2709	if (qualifier == 'L')
2710		spec->type = FORMAT_TYPE_LONG_LONG;
2711	else if (qualifier == 'l') {
2712		BUILD_BUG_ON(FORMAT_TYPE_ULONG + SIGN != FORMAT_TYPE_LONG);
2713		spec->type = FORMAT_TYPE_ULONG + (spec->flags & SIGN);
2714	} else if (qualifier == 'z') {
 
 
2715		spec->type = FORMAT_TYPE_SIZE_T;
2716	} else if (qualifier == 't') {
2717		spec->type = FORMAT_TYPE_PTRDIFF;
2718	} else if (qualifier == 'H') {
2719		BUILD_BUG_ON(FORMAT_TYPE_UBYTE + SIGN != FORMAT_TYPE_BYTE);
2720		spec->type = FORMAT_TYPE_UBYTE + (spec->flags & SIGN);
2721	} else if (qualifier == 'h') {
2722		BUILD_BUG_ON(FORMAT_TYPE_USHORT + SIGN != FORMAT_TYPE_SHORT);
2723		spec->type = FORMAT_TYPE_USHORT + (spec->flags & SIGN);
 
 
 
 
2724	} else {
2725		BUILD_BUG_ON(FORMAT_TYPE_UINT + SIGN != FORMAT_TYPE_INT);
2726		spec->type = FORMAT_TYPE_UINT + (spec->flags & SIGN);
 
 
2727	}
2728
2729	return ++fmt - start;
2730}
2731
2732static void
2733set_field_width(struct printf_spec *spec, int width)
2734{
2735	spec->field_width = width;
2736	if (WARN_ONCE(spec->field_width != width, "field width %d too large", width)) {
2737		spec->field_width = clamp(width, -FIELD_WIDTH_MAX, FIELD_WIDTH_MAX);
2738	}
2739}
2740
2741static void
2742set_precision(struct printf_spec *spec, int prec)
2743{
2744	spec->precision = prec;
2745	if (WARN_ONCE(spec->precision != prec, "precision %d too large", prec)) {
2746		spec->precision = clamp(prec, 0, PRECISION_MAX);
2747	}
2748}
2749
2750/**
2751 * vsnprintf - Format a string and place it in a buffer
2752 * @buf: The buffer to place the result into
2753 * @size: The size of the buffer, including the trailing null space
2754 * @fmt: The format string to use
2755 * @args: Arguments for the format string
2756 *
2757 * This function generally follows C99 vsnprintf, but has some
2758 * extensions and a few limitations:
2759 *
2760 *  - ``%n`` is unsupported
2761 *  - ``%p*`` is handled by pointer()
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2762 *
2763 * See pointer() or Documentation/core-api/printk-formats.rst for more
2764 * extensive description.
2765 *
2766 * **Please update the documentation in both places when making changes**
2767 *
2768 * The return value is the number of characters which would
2769 * be generated for the given input, excluding the trailing
2770 * '\0', as per ISO C99. If you want to have the exact
2771 * number of characters written into @buf as return value
2772 * (not including the trailing '\0'), use vscnprintf(). If the
2773 * return is greater than or equal to @size, the resulting
2774 * string is truncated.
2775 *
2776 * If you're not already dealing with a va_list consider using snprintf().
2777 */
2778int vsnprintf(char *buf, size_t size, const char *fmt, va_list args)
2779{
2780	unsigned long long num;
2781	char *str, *end;
2782	struct printf_spec spec = {0};
2783
2784	/* Reject out-of-range values early.  Large positive sizes are
2785	   used for unknown buffer sizes. */
2786	if (WARN_ON_ONCE(size > INT_MAX))
2787		return 0;
2788
2789	str = buf;
2790	end = buf + size;
2791
2792	/* Make sure end is always >= buf */
2793	if (end < buf) {
2794		end = ((void *)-1);
2795		size = end - buf;
2796	}
2797
2798	while (*fmt) {
2799		const char *old_fmt = fmt;
2800		int read = format_decode(fmt, &spec);
2801
2802		fmt += read;
2803
2804		switch (spec.type) {
2805		case FORMAT_TYPE_NONE: {
2806			int copy = read;
2807			if (str < end) {
2808				if (copy > end - str)
2809					copy = end - str;
2810				memcpy(str, old_fmt, copy);
2811			}
2812			str += read;
2813			break;
2814		}
2815
2816		case FORMAT_TYPE_WIDTH:
2817			set_field_width(&spec, va_arg(args, int));
2818			break;
2819
2820		case FORMAT_TYPE_PRECISION:
2821			set_precision(&spec, va_arg(args, int));
2822			break;
2823
2824		case FORMAT_TYPE_CHAR: {
2825			char c;
2826
2827			if (!(spec.flags & LEFT)) {
2828				while (--spec.field_width > 0) {
2829					if (str < end)
2830						*str = ' ';
2831					++str;
2832
2833				}
2834			}
2835			c = (unsigned char) va_arg(args, int);
2836			if (str < end)
2837				*str = c;
2838			++str;
2839			while (--spec.field_width > 0) {
2840				if (str < end)
2841					*str = ' ';
2842				++str;
2843			}
2844			break;
2845		}
2846
2847		case FORMAT_TYPE_STR:
2848			str = string(str, end, va_arg(args, char *), spec);
2849			break;
2850
2851		case FORMAT_TYPE_PTR:
2852			str = pointer(fmt, str, end, va_arg(args, void *),
2853				      spec);
2854			while (isalnum(*fmt))
2855				fmt++;
2856			break;
2857
2858		case FORMAT_TYPE_PERCENT_CHAR:
2859			if (str < end)
2860				*str = '%';
2861			++str;
2862			break;
2863
2864		case FORMAT_TYPE_INVALID:
2865			/*
2866			 * Presumably the arguments passed gcc's type
2867			 * checking, but there is no safe or sane way
2868			 * for us to continue parsing the format and
2869			 * fetching from the va_list; the remaining
2870			 * specifiers and arguments would be out of
2871			 * sync.
2872			 */
2873			goto out;
2874
2875		default:
2876			switch (spec.type) {
2877			case FORMAT_TYPE_LONG_LONG:
2878				num = va_arg(args, long long);
2879				break;
2880			case FORMAT_TYPE_ULONG:
2881				num = va_arg(args, unsigned long);
2882				break;
2883			case FORMAT_TYPE_LONG:
2884				num = va_arg(args, long);
2885				break;
2886			case FORMAT_TYPE_SIZE_T:
2887				if (spec.flags & SIGN)
2888					num = va_arg(args, ssize_t);
2889				else
2890					num = va_arg(args, size_t);
2891				break;
2892			case FORMAT_TYPE_PTRDIFF:
2893				num = va_arg(args, ptrdiff_t);
2894				break;
2895			case FORMAT_TYPE_UBYTE:
2896				num = (unsigned char) va_arg(args, int);
2897				break;
2898			case FORMAT_TYPE_BYTE:
2899				num = (signed char) va_arg(args, int);
2900				break;
2901			case FORMAT_TYPE_USHORT:
2902				num = (unsigned short) va_arg(args, int);
2903				break;
2904			case FORMAT_TYPE_SHORT:
2905				num = (short) va_arg(args, int);
2906				break;
2907			case FORMAT_TYPE_INT:
2908				num = (int) va_arg(args, int);
2909				break;
2910			default:
2911				num = va_arg(args, unsigned int);
2912			}
2913
2914			str = number(str, end, num, spec);
2915		}
2916	}
2917
2918out:
2919	if (size > 0) {
2920		if (str < end)
2921			*str = '\0';
2922		else
2923			end[-1] = '\0';
2924	}
2925
2926	/* the trailing null byte doesn't count towards the total */
2927	return str-buf;
2928
2929}
2930EXPORT_SYMBOL(vsnprintf);
2931
2932/**
2933 * vscnprintf - Format a string and place it in a buffer
2934 * @buf: The buffer to place the result into
2935 * @size: The size of the buffer, including the trailing null space
2936 * @fmt: The format string to use
2937 * @args: Arguments for the format string
2938 *
2939 * The return value is the number of characters which have been written into
2940 * the @buf not including the trailing '\0'. If @size is == 0 the function
2941 * returns 0.
2942 *
2943 * If you're not already dealing with a va_list consider using scnprintf().
2944 *
2945 * See the vsnprintf() documentation for format string extensions over C99.
2946 */
2947int vscnprintf(char *buf, size_t size, const char *fmt, va_list args)
2948{
2949	int i;
2950
2951	if (unlikely(!size))
2952		return 0;
2953
2954	i = vsnprintf(buf, size, fmt, args);
2955
2956	if (likely(i < size))
2957		return i;
2958
2959	return size - 1;
 
2960}
2961EXPORT_SYMBOL(vscnprintf);
2962
2963/**
2964 * snprintf - Format a string and place it in a buffer
2965 * @buf: The buffer to place the result into
2966 * @size: The size of the buffer, including the trailing null space
2967 * @fmt: The format string to use
2968 * @...: Arguments for the format string
2969 *
2970 * The return value is the number of characters which would be
2971 * generated for the given input, excluding the trailing null,
2972 * as per ISO C99.  If the return is greater than or equal to
2973 * @size, the resulting string is truncated.
2974 *
2975 * See the vsnprintf() documentation for format string extensions over C99.
2976 */
2977int snprintf(char *buf, size_t size, const char *fmt, ...)
2978{
2979	va_list args;
2980	int i;
2981
2982	va_start(args, fmt);
2983	i = vsnprintf(buf, size, fmt, args);
2984	va_end(args);
2985
2986	return i;
2987}
2988EXPORT_SYMBOL(snprintf);
2989
2990/**
2991 * scnprintf - Format a string and place it in a buffer
2992 * @buf: The buffer to place the result into
2993 * @size: The size of the buffer, including the trailing null space
2994 * @fmt: The format string to use
2995 * @...: Arguments for the format string
2996 *
2997 * The return value is the number of characters written into @buf not including
2998 * the trailing '\0'. If @size is == 0 the function returns 0.
2999 */
3000
3001int scnprintf(char *buf, size_t size, const char *fmt, ...)
3002{
3003	va_list args;
3004	int i;
3005
3006	va_start(args, fmt);
3007	i = vscnprintf(buf, size, fmt, args);
3008	va_end(args);
3009
3010	return i;
3011}
3012EXPORT_SYMBOL(scnprintf);
3013
3014/**
3015 * vsprintf - Format a string and place it in a buffer
3016 * @buf: The buffer to place the result into
3017 * @fmt: The format string to use
3018 * @args: Arguments for the format string
3019 *
3020 * The function returns the number of characters written
3021 * into @buf. Use vsnprintf() or vscnprintf() in order to avoid
3022 * buffer overflows.
3023 *
3024 * If you're not already dealing with a va_list consider using sprintf().
3025 *
3026 * See the vsnprintf() documentation for format string extensions over C99.
3027 */
3028int vsprintf(char *buf, const char *fmt, va_list args)
3029{
3030	return vsnprintf(buf, INT_MAX, fmt, args);
3031}
3032EXPORT_SYMBOL(vsprintf);
3033
3034/**
3035 * sprintf - Format a string and place it in a buffer
3036 * @buf: The buffer to place the result into
3037 * @fmt: The format string to use
3038 * @...: Arguments for the format string
3039 *
3040 * The function returns the number of characters written
3041 * into @buf. Use snprintf() or scnprintf() in order to avoid
3042 * buffer overflows.
3043 *
3044 * See the vsnprintf() documentation for format string extensions over C99.
3045 */
3046int sprintf(char *buf, const char *fmt, ...)
3047{
3048	va_list args;
3049	int i;
3050
3051	va_start(args, fmt);
3052	i = vsnprintf(buf, INT_MAX, fmt, args);
3053	va_end(args);
3054
3055	return i;
3056}
3057EXPORT_SYMBOL(sprintf);
3058
3059#ifdef CONFIG_BINARY_PRINTF
3060/*
3061 * bprintf service:
3062 * vbin_printf() - VA arguments to binary data
3063 * bstr_printf() - Binary data to text string
3064 */
3065
3066/**
3067 * vbin_printf - Parse a format string and place args' binary value in a buffer
3068 * @bin_buf: The buffer to place args' binary value
3069 * @size: The size of the buffer(by words(32bits), not characters)
3070 * @fmt: The format string to use
3071 * @args: Arguments for the format string
3072 *
3073 * The format follows C99 vsnprintf, except %n is ignored, and its argument
3074 * is skipped.
3075 *
3076 * The return value is the number of words(32bits) which would be generated for
3077 * the given input.
3078 *
3079 * NOTE:
3080 * If the return value is greater than @size, the resulting bin_buf is NOT
3081 * valid for bstr_printf().
3082 */
3083int vbin_printf(u32 *bin_buf, size_t size, const char *fmt, va_list args)
3084{
3085	struct printf_spec spec = {0};
3086	char *str, *end;
3087	int width;
3088
3089	str = (char *)bin_buf;
3090	end = (char *)(bin_buf + size);
3091
3092#define save_arg(type)							\
3093({									\
3094	unsigned long long value;					\
3095	if (sizeof(type) == 8) {					\
3096		unsigned long long val8;				\
3097		str = PTR_ALIGN(str, sizeof(u32));			\
3098		val8 = va_arg(args, unsigned long long);		\
3099		if (str + sizeof(type) <= end) {			\
3100			*(u32 *)str = *(u32 *)&val8;			\
3101			*(u32 *)(str + 4) = *((u32 *)&val8 + 1);	\
3102		}							\
3103		value = val8;						\
3104	} else {							\
3105		unsigned int val4;					\
3106		str = PTR_ALIGN(str, sizeof(type));			\
3107		val4 = va_arg(args, int);				\
3108		if (str + sizeof(type) <= end)				\
3109			*(typeof(type) *)str = (type)(long)val4;	\
3110		value = (unsigned long long)val4;			\
3111	}								\
3112	str += sizeof(type);						\
3113	value;								\
3114})
3115
3116	while (*fmt) {
3117		int read = format_decode(fmt, &spec);
3118
3119		fmt += read;
3120
3121		switch (spec.type) {
3122		case FORMAT_TYPE_NONE:
 
3123		case FORMAT_TYPE_PERCENT_CHAR:
3124			break;
3125		case FORMAT_TYPE_INVALID:
3126			goto out;
3127
3128		case FORMAT_TYPE_WIDTH:
3129		case FORMAT_TYPE_PRECISION:
3130			width = (int)save_arg(int);
3131			/* Pointers may require the width */
3132			if (*fmt == 'p')
3133				set_field_width(&spec, width);
3134			break;
3135
3136		case FORMAT_TYPE_CHAR:
3137			save_arg(char);
3138			break;
3139
3140		case FORMAT_TYPE_STR: {
3141			const char *save_str = va_arg(args, char *);
3142			const char *err_msg;
3143			size_t len;
3144
3145			err_msg = check_pointer_msg(save_str);
3146			if (err_msg)
3147				save_str = err_msg;
3148
3149			len = strlen(save_str) + 1;
3150			if (str + len < end)
3151				memcpy(str, save_str, len);
3152			str += len;
3153			break;
3154		}
3155
3156		case FORMAT_TYPE_PTR:
3157			/* Dereferenced pointers must be done now */
3158			switch (*fmt) {
3159			/* Dereference of functions is still OK */
3160			case 'S':
3161			case 's':
3162			case 'x':
3163			case 'K':
3164			case 'e':
3165				save_arg(void *);
3166				break;
3167			default:
3168				if (!isalnum(*fmt)) {
3169					save_arg(void *);
3170					break;
3171				}
3172				str = pointer(fmt, str, end, va_arg(args, void *),
3173					      spec);
3174				if (str + 1 < end)
3175					*str++ = '\0';
3176				else
3177					end[-1] = '\0'; /* Must be nul terminated */
3178			}
3179			/* skip all alphanumeric pointer suffixes */
3180			while (isalnum(*fmt))
3181				fmt++;
3182			break;
3183
3184		default:
3185			switch (spec.type) {
3186
3187			case FORMAT_TYPE_LONG_LONG:
3188				save_arg(long long);
3189				break;
3190			case FORMAT_TYPE_ULONG:
3191			case FORMAT_TYPE_LONG:
3192				save_arg(unsigned long);
3193				break;
3194			case FORMAT_TYPE_SIZE_T:
3195				save_arg(size_t);
3196				break;
3197			case FORMAT_TYPE_PTRDIFF:
3198				save_arg(ptrdiff_t);
3199				break;
3200			case FORMAT_TYPE_UBYTE:
3201			case FORMAT_TYPE_BYTE:
3202				save_arg(char);
3203				break;
3204			case FORMAT_TYPE_USHORT:
3205			case FORMAT_TYPE_SHORT:
3206				save_arg(short);
3207				break;
3208			default:
3209				save_arg(int);
3210			}
3211		}
3212	}
3213
3214out:
3215	return (u32 *)(PTR_ALIGN(str, sizeof(u32))) - bin_buf;
3216#undef save_arg
3217}
3218EXPORT_SYMBOL_GPL(vbin_printf);
3219
3220/**
3221 * bstr_printf - Format a string from binary arguments and place it in a buffer
3222 * @buf: The buffer to place the result into
3223 * @size: The size of the buffer, including the trailing null space
3224 * @fmt: The format string to use
3225 * @bin_buf: Binary arguments for the format string
3226 *
3227 * This function like C99 vsnprintf, but the difference is that vsnprintf gets
3228 * arguments from stack, and bstr_printf gets arguments from @bin_buf which is
3229 * a binary buffer that generated by vbin_printf.
3230 *
3231 * The format follows C99 vsnprintf, but has some extensions:
3232 *  see vsnprintf comment for details.
3233 *
3234 * The return value is the number of characters which would
3235 * be generated for the given input, excluding the trailing
3236 * '\0', as per ISO C99. If you want to have the exact
3237 * number of characters written into @buf as return value
3238 * (not including the trailing '\0'), use vscnprintf(). If the
3239 * return is greater than or equal to @size, the resulting
3240 * string is truncated.
3241 */
3242int bstr_printf(char *buf, size_t size, const char *fmt, const u32 *bin_buf)
3243{
3244	struct printf_spec spec = {0};
3245	char *str, *end;
3246	const char *args = (const char *)bin_buf;
3247
3248	if (WARN_ON_ONCE(size > INT_MAX))
3249		return 0;
3250
3251	str = buf;
3252	end = buf + size;
3253
3254#define get_arg(type)							\
3255({									\
3256	typeof(type) value;						\
3257	if (sizeof(type) == 8) {					\
3258		args = PTR_ALIGN(args, sizeof(u32));			\
3259		*(u32 *)&value = *(u32 *)args;				\
3260		*((u32 *)&value + 1) = *(u32 *)(args + 4);		\
3261	} else {							\
3262		args = PTR_ALIGN(args, sizeof(type));			\
3263		value = *(typeof(type) *)args;				\
3264	}								\
3265	args += sizeof(type);						\
3266	value;								\
3267})
3268
3269	/* Make sure end is always >= buf */
3270	if (end < buf) {
3271		end = ((void *)-1);
3272		size = end - buf;
3273	}
3274
3275	while (*fmt) {
3276		const char *old_fmt = fmt;
3277		int read = format_decode(fmt, &spec);
3278
3279		fmt += read;
3280
3281		switch (spec.type) {
3282		case FORMAT_TYPE_NONE: {
3283			int copy = read;
3284			if (str < end) {
3285				if (copy > end - str)
3286					copy = end - str;
3287				memcpy(str, old_fmt, copy);
3288			}
3289			str += read;
3290			break;
3291		}
3292
3293		case FORMAT_TYPE_WIDTH:
3294			set_field_width(&spec, get_arg(int));
3295			break;
3296
3297		case FORMAT_TYPE_PRECISION:
3298			set_precision(&spec, get_arg(int));
3299			break;
3300
3301		case FORMAT_TYPE_CHAR: {
3302			char c;
3303
3304			if (!(spec.flags & LEFT)) {
3305				while (--spec.field_width > 0) {
3306					if (str < end)
3307						*str = ' ';
3308					++str;
3309				}
3310			}
3311			c = (unsigned char) get_arg(char);
3312			if (str < end)
3313				*str = c;
3314			++str;
3315			while (--spec.field_width > 0) {
3316				if (str < end)
3317					*str = ' ';
3318				++str;
3319			}
3320			break;
3321		}
3322
3323		case FORMAT_TYPE_STR: {
3324			const char *str_arg = args;
3325			args += strlen(str_arg) + 1;
3326			str = string(str, end, (char *)str_arg, spec);
3327			break;
3328		}
3329
3330		case FORMAT_TYPE_PTR: {
3331			bool process = false;
3332			int copy, len;
3333			/* Non function dereferences were already done */
3334			switch (*fmt) {
3335			case 'S':
3336			case 's':
3337			case 'x':
3338			case 'K':
3339			case 'e':
3340				process = true;
3341				break;
3342			default:
3343				if (!isalnum(*fmt)) {
3344					process = true;
3345					break;
3346				}
3347				/* Pointer dereference was already processed */
3348				if (str < end) {
3349					len = copy = strlen(args);
3350					if (copy > end - str)
3351						copy = end - str;
3352					memcpy(str, args, copy);
3353					str += len;
3354					args += len + 1;
3355				}
3356			}
3357			if (process)
3358				str = pointer(fmt, str, end, get_arg(void *), spec);
3359
3360			while (isalnum(*fmt))
3361				fmt++;
3362			break;
3363		}
3364
3365		case FORMAT_TYPE_PERCENT_CHAR:
 
3366			if (str < end)
3367				*str = '%';
3368			++str;
3369			break;
3370
3371		case FORMAT_TYPE_INVALID:
3372			goto out;
3373
3374		default: {
3375			unsigned long long num;
3376
3377			switch (spec.type) {
3378
3379			case FORMAT_TYPE_LONG_LONG:
3380				num = get_arg(long long);
3381				break;
3382			case FORMAT_TYPE_ULONG:
3383			case FORMAT_TYPE_LONG:
3384				num = get_arg(unsigned long);
3385				break;
3386			case FORMAT_TYPE_SIZE_T:
3387				num = get_arg(size_t);
3388				break;
3389			case FORMAT_TYPE_PTRDIFF:
3390				num = get_arg(ptrdiff_t);
3391				break;
3392			case FORMAT_TYPE_UBYTE:
3393				num = get_arg(unsigned char);
3394				break;
3395			case FORMAT_TYPE_BYTE:
3396				num = get_arg(signed char);
3397				break;
3398			case FORMAT_TYPE_USHORT:
3399				num = get_arg(unsigned short);
3400				break;
3401			case FORMAT_TYPE_SHORT:
3402				num = get_arg(short);
3403				break;
3404			case FORMAT_TYPE_UINT:
3405				num = get_arg(unsigned int);
3406				break;
3407			default:
3408				num = get_arg(int);
3409			}
3410
3411			str = number(str, end, num, spec);
3412		} /* default: */
3413		} /* switch(spec.type) */
3414	} /* while(*fmt) */
3415
3416out:
3417	if (size > 0) {
3418		if (str < end)
3419			*str = '\0';
3420		else
3421			end[-1] = '\0';
3422	}
3423
3424#undef get_arg
3425
3426	/* the trailing null byte doesn't count towards the total */
3427	return str - buf;
3428}
3429EXPORT_SYMBOL_GPL(bstr_printf);
3430
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
3431#endif /* CONFIG_BINARY_PRINTF */
3432
3433/**
3434 * vsscanf - Unformat a buffer into a list of arguments
3435 * @buf:	input buffer
3436 * @fmt:	format of buffer
3437 * @args:	arguments
3438 */
3439int vsscanf(const char *buf, const char *fmt, va_list args)
3440{
3441	const char *str = buf;
3442	char *next;
3443	char digit;
3444	int num = 0;
3445	u8 qualifier;
3446	unsigned int base;
3447	union {
3448		long long s;
3449		unsigned long long u;
3450	} val;
3451	s16 field_width;
3452	bool is_sign;
3453
3454	while (*fmt) {
3455		/* skip any white space in format */
3456		/* white space in format matches any amount of
3457		 * white space, including none, in the input.
3458		 */
3459		if (isspace(*fmt)) {
3460			fmt = skip_spaces(++fmt);
3461			str = skip_spaces(str);
3462		}
3463
3464		/* anything that is not a conversion must match exactly */
3465		if (*fmt != '%' && *fmt) {
3466			if (*fmt++ != *str++)
3467				break;
3468			continue;
3469		}
3470
3471		if (!*fmt)
3472			break;
3473		++fmt;
3474
3475		/* skip this conversion.
3476		 * advance both strings to next white space
3477		 */
3478		if (*fmt == '*') {
3479			if (!*str)
3480				break;
3481			while (!isspace(*fmt) && *fmt != '%' && *fmt) {
3482				/* '%*[' not yet supported, invalid format */
3483				if (*fmt == '[')
3484					return num;
3485				fmt++;
3486			}
3487			while (!isspace(*str) && *str)
3488				str++;
3489			continue;
3490		}
3491
3492		/* get field width */
3493		field_width = -1;
3494		if (isdigit(*fmt)) {
3495			field_width = skip_atoi(&fmt);
3496			if (field_width <= 0)
3497				break;
3498		}
3499
3500		/* get conversion qualifier */
3501		qualifier = -1;
3502		if (*fmt == 'h' || _tolower(*fmt) == 'l' ||
3503		    *fmt == 'z') {
3504			qualifier = *fmt++;
3505			if (unlikely(qualifier == *fmt)) {
3506				if (qualifier == 'h') {
3507					qualifier = 'H';
3508					fmt++;
3509				} else if (qualifier == 'l') {
3510					qualifier = 'L';
3511					fmt++;
3512				}
3513			}
3514		}
3515
3516		if (!*fmt)
3517			break;
3518
3519		if (*fmt == 'n') {
3520			/* return number of characters read so far */
3521			*va_arg(args, int *) = str - buf;
3522			++fmt;
3523			continue;
3524		}
3525
3526		if (!*str)
3527			break;
3528
3529		base = 10;
3530		is_sign = false;
3531
3532		switch (*fmt++) {
3533		case 'c':
3534		{
3535			char *s = (char *)va_arg(args, char*);
3536			if (field_width == -1)
3537				field_width = 1;
3538			do {
3539				*s++ = *str++;
3540			} while (--field_width > 0 && *str);
3541			num++;
3542		}
3543		continue;
3544		case 's':
3545		{
3546			char *s = (char *)va_arg(args, char *);
3547			if (field_width == -1)
3548				field_width = SHRT_MAX;
3549			/* first, skip leading white space in buffer */
3550			str = skip_spaces(str);
3551
3552			/* now copy until next white space */
3553			while (*str && !isspace(*str) && field_width--)
3554				*s++ = *str++;
3555			*s = '\0';
3556			num++;
3557		}
3558		continue;
3559		/*
3560		 * Warning: This implementation of the '[' conversion specifier
3561		 * deviates from its glibc counterpart in the following ways:
3562		 * (1) It does NOT support ranges i.e. '-' is NOT a special
3563		 *     character
3564		 * (2) It cannot match the closing bracket ']' itself
3565		 * (3) A field width is required
3566		 * (4) '%*[' (discard matching input) is currently not supported
3567		 *
3568		 * Example usage:
3569		 * ret = sscanf("00:0a:95","%2[^:]:%2[^:]:%2[^:]",
3570		 *		buf1, buf2, buf3);
3571		 * if (ret < 3)
3572		 *    // etc..
3573		 */
3574		case '[':
3575		{
3576			char *s = (char *)va_arg(args, char *);
3577			DECLARE_BITMAP(set, 256) = {0};
3578			unsigned int len = 0;
3579			bool negate = (*fmt == '^');
3580
3581			/* field width is required */
3582			if (field_width == -1)
3583				return num;
3584
3585			if (negate)
3586				++fmt;
3587
3588			for ( ; *fmt && *fmt != ']'; ++fmt, ++len)
3589				__set_bit((u8)*fmt, set);
3590
3591			/* no ']' or no character set found */
3592			if (!*fmt || !len)
3593				return num;
3594			++fmt;
3595
3596			if (negate) {
3597				bitmap_complement(set, set, 256);
3598				/* exclude null '\0' byte */
3599				__clear_bit(0, set);
3600			}
3601
3602			/* match must be non-empty */
3603			if (!test_bit((u8)*str, set))
3604				return num;
3605
3606			while (test_bit((u8)*str, set) && field_width--)
3607				*s++ = *str++;
3608			*s = '\0';
3609			++num;
3610		}
3611		continue;
3612		case 'o':
3613			base = 8;
3614			break;
3615		case 'x':
3616		case 'X':
3617			base = 16;
3618			break;
3619		case 'i':
3620			base = 0;
3621			fallthrough;
3622		case 'd':
3623			is_sign = true;
3624			fallthrough;
3625		case 'u':
3626			break;
3627		case '%':
3628			/* looking for '%' in str */
3629			if (*str++ != '%')
3630				return num;
3631			continue;
3632		default:
3633			/* invalid format; stop here */
3634			return num;
3635		}
3636
3637		/* have some sort of integer conversion.
3638		 * first, skip white space in buffer.
3639		 */
3640		str = skip_spaces(str);
3641
3642		digit = *str;
3643		if (is_sign && digit == '-') {
3644			if (field_width == 1)
3645				break;
3646
3647			digit = *(str + 1);
3648		}
3649
3650		if (!digit
3651		    || (base == 16 && !isxdigit(digit))
3652		    || (base == 10 && !isdigit(digit))
3653		    || (base == 8 && !isodigit(digit))
3654		    || (base == 0 && !isdigit(digit)))
3655			break;
3656
3657		if (is_sign)
3658			val.s = simple_strntoll(str, &next, base,
3659						field_width >= 0 ? field_width : INT_MAX);
 
3660		else
3661			val.u = simple_strntoull(str, &next, base,
3662						 field_width >= 0 ? field_width : INT_MAX);
 
 
 
 
 
 
 
 
 
 
 
 
 
3663
3664		switch (qualifier) {
3665		case 'H':	/* that's 'hh' in format */
3666			if (is_sign)
3667				*va_arg(args, signed char *) = val.s;
3668			else
3669				*va_arg(args, unsigned char *) = val.u;
3670			break;
3671		case 'h':
3672			if (is_sign)
3673				*va_arg(args, short *) = val.s;
3674			else
3675				*va_arg(args, unsigned short *) = val.u;
3676			break;
3677		case 'l':
3678			if (is_sign)
3679				*va_arg(args, long *) = val.s;
3680			else
3681				*va_arg(args, unsigned long *) = val.u;
3682			break;
3683		case 'L':
3684			if (is_sign)
3685				*va_arg(args, long long *) = val.s;
3686			else
3687				*va_arg(args, unsigned long long *) = val.u;
3688			break;
 
3689		case 'z':
3690			*va_arg(args, size_t *) = val.u;
3691			break;
3692		default:
3693			if (is_sign)
3694				*va_arg(args, int *) = val.s;
3695			else
3696				*va_arg(args, unsigned int *) = val.u;
3697			break;
3698		}
3699		num++;
3700
3701		if (!next)
3702			break;
3703		str = next;
3704	}
3705
3706	return num;
3707}
3708EXPORT_SYMBOL(vsscanf);
3709
3710/**
3711 * sscanf - Unformat a buffer into a list of arguments
3712 * @buf:	input buffer
3713 * @fmt:	formatting of buffer
3714 * @...:	resulting arguments
3715 */
3716int sscanf(const char *buf, const char *fmt, ...)
3717{
3718	va_list args;
3719	int i;
3720
3721	va_start(args, fmt);
3722	i = vsscanf(buf, fmt, args);
3723	va_end(args);
3724
3725	return i;
3726}
3727EXPORT_SYMBOL(sscanf);