linux/lib/vsprintf.c
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   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  44 * This function is obsolete.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  69 * This function is obsolete.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_NRCHARS,
 368        FORMAT_TYPE_SIZE_T,
 369        FORMAT_TYPE_PTRDIFF
 370};
 371
 372struct printf_spec {
 373        u8      type;           /* format_type enum */
 374        u8      flags;          /* flags to number() */
 375        u8      base;           /* number base, 8, 10 or 16 only */
 376        u8      qualifier;      /* number qualifier, one of 'hHlLtzZ' */
 377        s16     field_width;    /* width of output field */
 378        s16     precision;      /* # of digits/chars */
 379};
 380
 381static noinline_for_stack
 382char *number(char *buf, char *end, unsigned long long num,
 383             struct printf_spec spec)
 384{
 385        /* we are called with base 8, 10 or 16, only, thus don't need "G..."  */
 386        static const char digits[16] = "0123456789ABCDEF"; /* "GHIJKLMNOPQRSTUVWXYZ"; */
 387
 388        char tmp[66];
 389        char sign;
 390        char locase;
 391        int need_pfx = ((spec.flags & SPECIAL) && spec.base != 10);
 392        int i;
 393        bool is_zero = num == 0LL;
 394
 395        /* locase = 0 or 0x20. ORing digits or letters with 'locase'
 396         * produces same digits or (maybe lowercased) letters */
 397        locase = (spec.flags & SMALL);
 398        if (spec.flags & LEFT)
 399                spec.flags &= ~ZEROPAD;
 400        sign = 0;
 401        if (spec.flags & SIGN) {
 402                if ((signed long long)num < 0) {
 403                        sign = '-';
 404                        num = -(signed long long)num;
 405                        spec.field_width--;
 406                } else if (spec.flags & PLUS) {
 407                        sign = '+';
 408                        spec.field_width--;
 409                } else if (spec.flags & SPACE) {
 410                        sign = ' ';
 411                        spec.field_width--;
 412                }
 413        }
 414        if (need_pfx) {
 415                if (spec.base == 16)
 416                        spec.field_width -= 2;
 417                else if (!is_zero)
 418                        spec.field_width--;
 419        }
 420
 421        /* generate full string in tmp[], in reverse order */
 422        i = 0;
 423        if (num < spec.base)
 424                tmp[i++] = digits[num] | locase;
 425        /* Generic code, for any base:
 426        else do {
 427                tmp[i++] = (digits[do_div(num,base)] | locase);
 428        } while (num != 0);
 429        */
 430        else if (spec.base != 10) { /* 8 or 16 */
 431                int mask = spec.base - 1;
 432                int shift = 3;
 433
 434                if (spec.base == 16)
 435                        shift = 4;
 436                do {
 437                        tmp[i++] = (digits[((unsigned char)num) & mask] | locase);
 438                        num >>= shift;
 439                } while (num);
 440        } else { /* base 10 */
 441                i = put_dec(tmp, num) - tmp;
 442        }
 443
 444        /* printing 100 using %2d gives "100", not "00" */
 445        if (i > spec.precision)
 446                spec.precision = i;
 447        /* leading space padding */
 448        spec.field_width -= spec.precision;
 449        if (!(spec.flags & (ZEROPAD+LEFT))) {
 450                while (--spec.field_width >= 0) {
 451                        if (buf < end)
 452                                *buf = ' ';
 453                        ++buf;
 454                }
 455        }
 456        /* sign */
 457        if (sign) {
 458                if (buf < end)
 459                        *buf = sign;
 460                ++buf;
 461        }
 462        /* "0x" / "0" prefix */
 463        if (need_pfx) {
 464                if (spec.base == 16 || !is_zero) {
 465                        if (buf < end)
 466                                *buf = '0';
 467                        ++buf;
 468                }
 469                if (spec.base == 16) {
 470                        if (buf < end)
 471                                *buf = ('X' | locase);
 472                        ++buf;
 473                }
 474        }
 475        /* zero or space padding */
 476        if (!(spec.flags & LEFT)) {
 477                char c = (spec.flags & ZEROPAD) ? '0' : ' ';
 478                while (--spec.field_width >= 0) {
 479                        if (buf < end)
 480                                *buf = c;
 481                        ++buf;
 482                }
 483        }
 484        /* hmm even more zero padding? */
 485        while (i <= --spec.precision) {
 486                if (buf < end)
 487                        *buf = '0';
 488                ++buf;
 489        }
 490        /* actual digits of result */
 491        while (--i >= 0) {
 492                if (buf < end)
 493                        *buf = tmp[i];
 494                ++buf;
 495        }
 496        /* trailing space padding */
 497        while (--spec.field_width >= 0) {
 498                if (buf < end)
 499                        *buf = ' ';
 500                ++buf;
 501        }
 502
 503        return buf;
 504}
 505
 506static noinline_for_stack
 507char *string(char *buf, char *end, const char *s, struct printf_spec spec)
 508{
 509        int len, i;
 510
 511        if ((unsigned long)s < PAGE_SIZE)
 512                s = "(null)";
 513
 514        len = strnlen(s, spec.precision);
 515
 516        if (!(spec.flags & LEFT)) {
 517                while (len < spec.field_width--) {
 518                        if (buf < end)
 519                                *buf = ' ';
 520                        ++buf;
 521                }
 522        }
 523        for (i = 0; i < len; ++i) {
 524                if (buf < end)
 525                        *buf = *s;
 526                ++buf; ++s;
 527        }
 528        while (len < spec.field_width--) {
 529                if (buf < end)
 530                        *buf = ' ';
 531                ++buf;
 532        }
 533
 534        return buf;
 535}
 536
 537static void widen(char *buf, char *end, unsigned len, unsigned spaces)
 538{
 539        size_t size;
 540        if (buf >= end) /* nowhere to put anything */
 541                return;
 542        size = end - buf;
 543        if (size <= spaces) {
 544                memset(buf, ' ', size);
 545                return;
 546        }
 547        if (len) {
 548                if (len > size - spaces)
 549                        len = size - spaces;
 550                memmove(buf + spaces, buf, len);
 551        }
 552        memset(buf, ' ', spaces);
 553}
 554
 555static noinline_for_stack
 556char *dentry_name(char *buf, char *end, const struct dentry *d, struct printf_spec spec,
 557                  const char *fmt)
 558{
 559        const char *array[4], *s;
 560        const struct dentry *p;
 561        int depth;
 562        int i, n;
 563
 564        switch (fmt[1]) {
 565                case '2': case '3': case '4':
 566                        depth = fmt[1] - '0';
 567                        break;
 568                default:
 569                        depth = 1;
 570        }
 571
 572        rcu_read_lock();
 573        for (i = 0; i < depth; i++, d = p) {
 574                p = ACCESS_ONCE(d->d_parent);
 575                array[i] = ACCESS_ONCE(d->d_name.name);
 576                if (p == d) {
 577                        if (i)
 578                                array[i] = "";
 579                        i++;
 580                        break;
 581                }
 582        }
 583        s = array[--i];
 584        for (n = 0; n != spec.precision; n++, buf++) {
 585                char c = *s++;
 586                if (!c) {
 587                        if (!i)
 588                                break;
 589                        c = '/';
 590                        s = array[--i];
 591                }
 592                if (buf < end)
 593                        *buf = c;
 594        }
 595        rcu_read_unlock();
 596        if (n < spec.field_width) {
 597                /* we want to pad the sucker */
 598                unsigned spaces = spec.field_width - n;
 599                if (!(spec.flags & LEFT)) {
 600                        widen(buf - n, end, n, spaces);
 601                        return buf + spaces;
 602                }
 603                while (spaces--) {
 604                        if (buf < end)
 605                                *buf = ' ';
 606                        ++buf;
 607                }
 608        }
 609        return buf;
 610}
 611
 612static noinline_for_stack
 613char *symbol_string(char *buf, char *end, void *ptr,
 614                    struct printf_spec spec, const char *fmt)
 615{
 616        unsigned long value;
 617#ifdef CONFIG_KALLSYMS
 618        char sym[KSYM_SYMBOL_LEN];
 619#endif
 620
 621        if (fmt[1] == 'R')
 622                ptr = __builtin_extract_return_addr(ptr);
 623        value = (unsigned long)ptr;
 624
 625#ifdef CONFIG_KALLSYMS
 626        if (*fmt == 'B')
 627                sprint_backtrace(sym, value);
 628        else if (*fmt != 'f' && *fmt != 's')
 629                sprint_symbol(sym, value);
 630        else
 631                sprint_symbol_no_offset(sym, value);
 632
 633        return string(buf, end, sym, spec);
 634#else
 635        spec.field_width = 2 * sizeof(void *);
 636        spec.flags |= SPECIAL | SMALL | ZEROPAD;
 637        spec.base = 16;
 638
 639        return number(buf, end, value, spec);
 640#endif
 641}
 642
 643static noinline_for_stack
 644char *resource_string(char *buf, char *end, struct resource *res,
 645                      struct printf_spec spec, const char *fmt)
 646{
 647#ifndef IO_RSRC_PRINTK_SIZE
 648#define IO_RSRC_PRINTK_SIZE     6
 649#endif
 650
 651#ifndef MEM_RSRC_PRINTK_SIZE
 652#define MEM_RSRC_PRINTK_SIZE    10
 653#endif
 654        static const struct printf_spec io_spec = {
 655                .base = 16,
 656                .field_width = IO_RSRC_PRINTK_SIZE,
 657                .precision = -1,
 658                .flags = SPECIAL | SMALL | ZEROPAD,
 659        };
 660        static const struct printf_spec mem_spec = {
 661                .base = 16,
 662                .field_width = MEM_RSRC_PRINTK_SIZE,
 663                .precision = -1,
 664                .flags = SPECIAL | SMALL | ZEROPAD,
 665        };
 666        static const struct printf_spec bus_spec = {
 667                .base = 16,
 668                .field_width = 2,
 669                .precision = -1,
 670                .flags = SMALL | ZEROPAD,
 671        };
 672        static const struct printf_spec dec_spec = {
 673                .base = 10,
 674                .precision = -1,
 675                .flags = 0,
 676        };
 677        static const struct printf_spec str_spec = {
 678                .field_width = -1,
 679                .precision = 10,
 680                .flags = LEFT,
 681        };
 682        static const struct printf_spec flag_spec = {
 683                .base = 16,
 684                .precision = -1,
 685                .flags = SPECIAL | SMALL,
 686        };
 687
 688        /* 32-bit res (sizeof==4): 10 chars in dec, 10 in hex ("0x" + 8)
 689         * 64-bit res (sizeof==8): 20 chars in dec, 18 in hex ("0x" + 16) */
 690#define RSRC_BUF_SIZE           ((2 * sizeof(resource_size_t)) + 4)
 691#define FLAG_BUF_SIZE           (2 * sizeof(res->flags))
 692#define DECODED_BUF_SIZE        sizeof("[mem - 64bit pref window disabled]")
 693#define RAW_BUF_SIZE            sizeof("[mem - flags 0x]")
 694        char sym[max(2*RSRC_BUF_SIZE + DECODED_BUF_SIZE,
 695                     2*RSRC_BUF_SIZE + FLAG_BUF_SIZE + RAW_BUF_SIZE)];
 696
 697        char *p = sym, *pend = sym + sizeof(sym);
 698        int decode = (fmt[0] == 'R') ? 1 : 0;
 699        const struct printf_spec *specp;
 700
 701        *p++ = '[';
 702        if (res->flags & IORESOURCE_IO) {
 703                p = string(p, pend, "io  ", str_spec);
 704                specp = &io_spec;
 705        } else if (res->flags & IORESOURCE_MEM) {
 706                p = string(p, pend, "mem ", str_spec);
 707                specp = &mem_spec;
 708        } else if (res->flags & IORESOURCE_IRQ) {
 709                p = string(p, pend, "irq ", str_spec);
 710                specp = &dec_spec;
 711        } else if (res->flags & IORESOURCE_DMA) {
 712                p = string(p, pend, "dma ", str_spec);
 713                specp = &dec_spec;
 714        } else if (res->flags & IORESOURCE_BUS) {
 715                p = string(p, pend, "bus ", str_spec);
 716                specp = &bus_spec;
 717        } else {
 718                p = string(p, pend, "??? ", str_spec);
 719                specp = &mem_spec;
 720                decode = 0;
 721        }
 722        p = number(p, pend, res->start, *specp);
 723        if (res->start != res->end) {
 724                *p++ = '-';
 725                p = number(p, pend, res->end, *specp);
 726        }
 727        if (decode) {
 728                if (res->flags & IORESOURCE_MEM_64)
 729                        p = string(p, pend, " 64bit", str_spec);
 730                if (res->flags & IORESOURCE_PREFETCH)
 731                        p = string(p, pend, " pref", str_spec);
 732                if (res->flags & IORESOURCE_WINDOW)
 733                        p = string(p, pend, " window", str_spec);
 734                if (res->flags & IORESOURCE_DISABLED)
 735                        p = string(p, pend, " disabled", str_spec);
 736        } else {
 737                p = string(p, pend, " flags ", str_spec);
 738                p = number(p, pend, res->flags, flag_spec);
 739        }
 740        *p++ = ']';
 741        *p = '\0';
 742
 743        return string(buf, end, sym, spec);
 744}
 745
 746static noinline_for_stack
 747char *hex_string(char *buf, char *end, u8 *addr, struct printf_spec spec,
 748                 const char *fmt)
 749{
 750        int i, len = 1;         /* if we pass '%ph[CDN]', field width remains
 751                                   negative value, fallback to the default */
 752        char separator;
 753
 754        if (spec.field_width == 0)
 755                /* nothing to print */
 756                return buf;
 757
 758        if (ZERO_OR_NULL_PTR(addr))
 759                /* NULL pointer */
 760                return string(buf, end, NULL, spec);
 761
 762        switch (fmt[1]) {
 763        case 'C':
 764                separator = ':';
 765                break;
 766        case 'D':
 767                separator = '-';
 768                break;
 769        case 'N':
 770                separator = 0;
 771                break;
 772        default:
 773                separator = ' ';
 774                break;
 775        }
 776
 777        if (spec.field_width > 0)
 778                len = min_t(int, spec.field_width, 64);
 779
 780        for (i = 0; i < len && buf < end - 1; i++) {
 781                buf = hex_byte_pack(buf, addr[i]);
 782
 783                if (buf < end && separator && i != len - 1)
 784                        *buf++ = separator;
 785        }
 786
 787        return buf;
 788}
 789
 790static noinline_for_stack
 791char *mac_address_string(char *buf, char *end, u8 *addr,
 792                         struct printf_spec spec, const char *fmt)
 793{
 794        char mac_addr[sizeof("xx:xx:xx:xx:xx:xx")];
 795        char *p = mac_addr;
 796        int i;
 797        char separator;
 798        bool reversed = false;
 799
 800        switch (fmt[1]) {
 801        case 'F':
 802                separator = '-';
 803                break;
 804
 805        case 'R':
 806                reversed = true;
 807                /* fall through */
 808
 809        default:
 810                separator = ':';
 811                break;
 812        }
 813
 814        for (i = 0; i < 6; i++) {
 815                if (reversed)
 816                        p = hex_byte_pack(p, addr[5 - i]);
 817                else
 818                        p = hex_byte_pack(p, addr[i]);
 819
 820                if (fmt[0] == 'M' && i != 5)
 821                        *p++ = separator;
 822        }
 823        *p = '\0';
 824
 825        return string(buf, end, mac_addr, spec);
 826}
 827
 828static noinline_for_stack
 829char *ip4_string(char *p, const u8 *addr, const char *fmt)
 830{
 831        int i;
 832        bool leading_zeros = (fmt[0] == 'i');
 833        int index;
 834        int step;
 835
 836        switch (fmt[2]) {
 837        case 'h':
 838#ifdef __BIG_ENDIAN
 839                index = 0;
 840                step = 1;
 841#else
 842                index = 3;
 843                step = -1;
 844#endif
 845                break;
 846        case 'l':
 847                index = 3;
 848                step = -1;
 849                break;
 850        case 'n':
 851        case 'b':
 852        default:
 853                index = 0;
 854                step = 1;
 855                break;
 856        }
 857        for (i = 0; i < 4; i++) {
 858                char temp[3];   /* hold each IP quad in reverse order */
 859                int digits = put_dec_trunc8(temp, addr[index]) - temp;
 860                if (leading_zeros) {
 861                        if (digits < 3)
 862                                *p++ = '0';
 863                        if (digits < 2)
 864                                *p++ = '0';
 865                }
 866                /* reverse the digits in the quad */
 867                while (digits--)
 868                        *p++ = temp[digits];
 869                if (i < 3)
 870                        *p++ = '.';
 871                index += step;
 872        }
 873        *p = '\0';
 874
 875        return p;
 876}
 877
 878static noinline_for_stack
 879char *ip6_compressed_string(char *p, const char *addr)
 880{
 881        int i, j, range;
 882        unsigned char zerolength[8];
 883        int longest = 1;
 884        int colonpos = -1;
 885        u16 word;
 886        u8 hi, lo;
 887        bool needcolon = false;
 888        bool useIPv4;
 889        struct in6_addr in6;
 890
 891        memcpy(&in6, addr, sizeof(struct in6_addr));
 892
 893        useIPv4 = ipv6_addr_v4mapped(&in6) || ipv6_addr_is_isatap(&in6);
 894
 895        memset(zerolength, 0, sizeof(zerolength));
 896
 897        if (useIPv4)
 898                range = 6;
 899        else
 900                range = 8;
 901
 902        /* find position of longest 0 run */
 903        for (i = 0; i < range; i++) {
 904                for (j = i; j < range; j++) {
 905                        if (in6.s6_addr16[j] != 0)
 906                                break;
 907                        zerolength[i]++;
 908                }
 909        }
 910        for (i = 0; i < range; i++) {
 911                if (zerolength[i] > longest) {
 912                        longest = zerolength[i];
 913                        colonpos = i;
 914                }
 915        }
 916        if (longest == 1)               /* don't compress a single 0 */
 917                colonpos = -1;
 918
 919        /* emit address */
 920        for (i = 0; i < range; i++) {
 921                if (i == colonpos) {
 922                        if (needcolon || i == 0)
 923                                *p++ = ':';
 924                        *p++ = ':';
 925                        needcolon = false;
 926                        i += longest - 1;
 927                        continue;
 928                }
 929                if (needcolon) {
 930                        *p++ = ':';
 931                        needcolon = false;
 932                }
 933                /* hex u16 without leading 0s */
 934                word = ntohs(in6.s6_addr16[i]);
 935                hi = word >> 8;
 936                lo = word & 0xff;
 937                if (hi) {
 938                        if (hi > 0x0f)
 939                                p = hex_byte_pack(p, hi);
 940                        else
 941                                *p++ = hex_asc_lo(hi);
 942                        p = hex_byte_pack(p, lo);
 943                }
 944                else if (lo > 0x0f)
 945                        p = hex_byte_pack(p, lo);
 946                else
 947                        *p++ = hex_asc_lo(lo);
 948                needcolon = true;
 949        }
 950
 951        if (useIPv4) {
 952                if (needcolon)
 953                        *p++ = ':';
 954                p = ip4_string(p, &in6.s6_addr[12], "I4");
 955        }
 956        *p = '\0';
 957
 958        return p;
 959}
 960
 961static noinline_for_stack
 962char *ip6_string(char *p, const char *addr, const char *fmt)
 963{
 964        int i;
 965
 966        for (i = 0; i < 8; i++) {
 967                p = hex_byte_pack(p, *addr++);
 968                p = hex_byte_pack(p, *addr++);
 969                if (fmt[0] == 'I' && i != 7)
 970                        *p++ = ':';
 971        }
 972        *p = '\0';
 973
 974        return p;
 975}
 976
 977static noinline_for_stack
 978char *ip6_addr_string(char *buf, char *end, const u8 *addr,
 979                      struct printf_spec spec, const char *fmt)
 980{
 981        char ip6_addr[sizeof("xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255")];
 982
 983        if (fmt[0] == 'I' && fmt[2] == 'c')
 984                ip6_compressed_string(ip6_addr, addr);
 985        else
 986                ip6_string(ip6_addr, addr, fmt);
 987
 988        return string(buf, end, ip6_addr, spec);
 989}
 990
 991static noinline_for_stack
 992char *ip4_addr_string(char *buf, char *end, const u8 *addr,
 993                      struct printf_spec spec, const char *fmt)
 994{
 995        char ip4_addr[sizeof("255.255.255.255")];
 996
 997        ip4_string(ip4_addr, addr, fmt);
 998
 999        return string(buf, end, ip4_addr, spec);
1000}
1001
1002static noinline_for_stack
1003char *ip6_addr_string_sa(char *buf, char *end, const struct sockaddr_in6 *sa,
1004                         struct printf_spec spec, const char *fmt)
1005{
1006        bool have_p = false, have_s = false, have_f = false, have_c = false;
1007        char ip6_addr[sizeof("[xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255]") +
1008                      sizeof(":12345") + sizeof("/123456789") +
1009                      sizeof("%1234567890")];
1010        char *p = ip6_addr, *pend = ip6_addr + sizeof(ip6_addr);
1011        const u8 *addr = (const u8 *) &sa->sin6_addr;
1012        char fmt6[2] = { fmt[0], '6' };
1013        u8 off = 0;
1014
1015        fmt++;
1016        while (isalpha(*++fmt)) {
1017                switch (*fmt) {
1018                case 'p':
1019                        have_p = true;
1020                        break;
1021                case 'f':
1022                        have_f = true;
1023                        break;
1024                case 's':
1025                        have_s = true;
1026                        break;
1027                case 'c':
1028                        have_c = true;
1029                        break;
1030                }
1031        }
1032
1033        if (have_p || have_s || have_f) {
1034                *p = '[';
1035                off = 1;
1036        }
1037
1038        if (fmt6[0] == 'I' && have_c)
1039                p = ip6_compressed_string(ip6_addr + off, addr);
1040        else
1041                p = ip6_string(ip6_addr + off, addr, fmt6);
1042
1043        if (have_p || have_s || have_f)
1044                *p++ = ']';
1045
1046        if (have_p) {
1047                *p++ = ':';
1048                p = number(p, pend, ntohs(sa->sin6_port), spec);
1049        }
1050        if (have_f) {
1051                *p++ = '/';
1052                p = number(p, pend, ntohl(sa->sin6_flowinfo &
1053                                          IPV6_FLOWINFO_MASK), spec);
1054        }
1055        if (have_s) {
1056                *p++ = '%';
1057                p = number(p, pend, sa->sin6_scope_id, spec);
1058        }
1059        *p = '\0';
1060
1061        return string(buf, end, ip6_addr, spec);
1062}
1063
1064static noinline_for_stack
1065char *ip4_addr_string_sa(char *buf, char *end, const struct sockaddr_in *sa,
1066                         struct printf_spec spec, const char *fmt)
1067{
1068        bool have_p = false;
1069        char *p, ip4_addr[sizeof("255.255.255.255") + sizeof(":12345")];
1070        char *pend = ip4_addr + sizeof(ip4_addr);
1071        const u8 *addr = (const u8 *) &sa->sin_addr.s_addr;
1072        char fmt4[3] = { fmt[0], '4', 0 };
1073
1074        fmt++;
1075        while (isalpha(*++fmt)) {
1076                switch (*fmt) {
1077                case 'p':
1078                        have_p = true;
1079                        break;
1080                case 'h':
1081                case 'l':
1082                case 'n':
1083                case 'b':
1084                        fmt4[2] = *fmt;
1085                        break;
1086                }
1087        }
1088
1089        p = ip4_string(ip4_addr, addr, fmt4);
1090        if (have_p) {
1091                *p++ = ':';
1092                p = number(p, pend, ntohs(sa->sin_port), spec);
1093        }
1094        *p = '\0';
1095
1096        return string(buf, end, ip4_addr, spec);
1097}
1098
1099static noinline_for_stack
1100char *uuid_string(char *buf, char *end, const u8 *addr,
1101                  struct printf_spec spec, const char *fmt)
1102{
1103        char uuid[sizeof("xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx")];
1104        char *p = uuid;
1105        int i;
1106        static const u8 be[16] = {0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15};
1107        static const u8 le[16] = {3,2,1,0,5,4,7,6,8,9,10,11,12,13,14,15};
1108        const u8 *index = be;
1109        bool uc = false;
1110
1111        switch (*(++fmt)) {
1112        case 'L':
1113                uc = true;              /* fall-through */
1114        case 'l':
1115                index = le;
1116                break;
1117        case 'B':
1118                uc = true;
1119                break;
1120        }
1121
1122        for (i = 0; i < 16; i++) {
1123                p = hex_byte_pack(p, addr[index[i]]);
1124                switch (i) {
1125                case 3:
1126                case 5:
1127                case 7:
1128                case 9:
1129                        *p++ = '-';
1130                        break;
1131                }
1132        }
1133
1134        *p = 0;
1135
1136        if (uc) {
1137                p = uuid;
1138                do {
1139                        *p = toupper(*p);
1140                } while (*(++p));
1141        }
1142
1143        return string(buf, end, uuid, spec);
1144}
1145
1146static
1147char *netdev_feature_string(char *buf, char *end, const u8 *addr,
1148                      struct printf_spec spec)
1149{
1150        spec.flags |= SPECIAL | SMALL | ZEROPAD;
1151        if (spec.field_width == -1)
1152                spec.field_width = 2 + 2 * sizeof(netdev_features_t);
1153        spec.base = 16;
1154
1155        return number(buf, end, *(const netdev_features_t *)addr, spec);
1156}
1157
1158static noinline_for_stack
1159char *address_val(char *buf, char *end, const void *addr,
1160                  struct printf_spec spec, const char *fmt)
1161{
1162        unsigned long long num;
1163
1164        spec.flags |= SPECIAL | SMALL | ZEROPAD;
1165        spec.base = 16;
1166
1167        switch (fmt[1]) {
1168        case 'd':
1169                num = *(const dma_addr_t *)addr;
1170                spec.field_width = sizeof(dma_addr_t) * 2 + 2;
1171                break;
1172        case 'p':
1173        default:
1174                num = *(const phys_addr_t *)addr;
1175                spec.field_width = sizeof(phys_addr_t) * 2 + 2;
1176                break;
1177        }
1178
1179        return number(buf, end, num, spec);
1180}
1181
1182int kptr_restrict __read_mostly;
1183
1184/*
1185 * Show a '%p' thing.  A kernel extension is that the '%p' is followed
1186 * by an extra set of alphanumeric characters that are extended format
1187 * specifiers.
1188 *
1189 * Right now we handle:
1190 *
1191 * - 'F' For symbolic function descriptor pointers with offset
1192 * - 'f' For simple symbolic function names without offset
1193 * - 'S' For symbolic direct pointers with offset
1194 * - 's' For symbolic direct pointers without offset
1195 * - '[FfSs]R' as above with __builtin_extract_return_addr() translation
1196 * - 'B' For backtraced symbolic direct pointers with offset
1197 * - 'R' For decoded struct resource, e.g., [mem 0x0-0x1f 64bit pref]
1198 * - 'r' For raw struct resource, e.g., [mem 0x0-0x1f flags 0x201]
1199 * - 'M' For a 6-byte MAC address, it prints the address in the
1200 *       usual colon-separated hex notation
1201 * - 'm' For a 6-byte MAC address, it prints the hex address without colons
1202 * - 'MF' For a 6-byte MAC FDDI address, it prints the address
1203 *       with a dash-separated hex notation
1204 * - '[mM]R' For a 6-byte MAC address, Reverse order (Bluetooth)
1205 * - 'I' [46] for IPv4/IPv6 addresses printed in the usual way
1206 *       IPv4 uses dot-separated decimal without leading 0's (1.2.3.4)
1207 *       IPv6 uses colon separated network-order 16 bit hex with leading 0's
1208 *       [S][pfs]
1209 *       Generic IPv4/IPv6 address (struct sockaddr *) that falls back to
1210 *       [4] or [6] and is able to print port [p], flowinfo [f], scope [s]
1211 * - 'i' [46] for 'raw' IPv4/IPv6 addresses
1212 *       IPv6 omits the colons (01020304...0f)
1213 *       IPv4 uses dot-separated decimal with leading 0's (010.123.045.006)
1214 *       [S][pfs]
1215 *       Generic IPv4/IPv6 address (struct sockaddr *) that falls back to
1216 *       [4] or [6] and is able to print port [p], flowinfo [f], scope [s]
1217 * - '[Ii][4S][hnbl]' IPv4 addresses in host, network, big or little endian order
1218 * - 'I[6S]c' for IPv6 addresses printed as specified by
1219 *       http://tools.ietf.org/html/rfc5952
1220 * - 'U' For a 16 byte UUID/GUID, it prints the UUID/GUID in the form
1221 *       "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx"
1222 *       Options for %pU are:
1223 *         b big endian lower case hex (default)
1224 *         B big endian UPPER case hex
1225 *         l little endian lower case hex
1226 *         L little endian UPPER case hex
1227 *           big endian output byte order is:
1228 *             [0][1][2][3]-[4][5]-[6][7]-[8][9]-[10][11][12][13][14][15]
1229 *           little endian output byte order is:
1230 *             [3][2][1][0]-[5][4]-[7][6]-[8][9]-[10][11][12][13][14][15]
1231 * - 'V' For a struct va_format which contains a format string * and va_list *,
1232 *       call vsnprintf(->format, *->va_list).
1233 *       Implements a "recursive vsnprintf".
1234 *       Do not use this feature without some mechanism to verify the
1235 *       correctness of the format string and va_list arguments.
1236 * - 'K' For a kernel pointer that should be hidden from unprivileged users
1237 * - 'NF' For a netdev_features_t
1238 * - 'h[CDN]' For a variable-length buffer, it prints it as a hex string with
1239 *            a certain separator (' ' by default):
1240 *              C colon
1241 *              D dash
1242 *              N no separator
1243 *            The maximum supported length is 64 bytes of the input. Consider
1244 *            to use print_hex_dump() for the larger input.
1245 * - 'a[pd]' For address types [p] phys_addr_t, [d] dma_addr_t and derivatives
1246 *           (default assumed to be phys_addr_t, passed by reference)
1247 * - 'd[234]' For a dentry name (optionally 2-4 last components)
1248 * - 'D[234]' Same as 'd' but for a struct file
1249 *
1250 * Note: The difference between 'S' and 'F' is that on ia64 and ppc64
1251 * function pointers are really function descriptors, which contain a
1252 * pointer to the real address.
1253 */
1254static noinline_for_stack
1255char *pointer(const char *fmt, char *buf, char *end, void *ptr,
1256              struct printf_spec spec)
1257{
1258        int default_width = 2 * sizeof(void *) + (spec.flags & SPECIAL ? 2 : 0);
1259
1260        if (!ptr && *fmt != 'K') {
1261                /*
1262                 * Print (null) with the same width as a pointer so it makes
1263                 * tabular output look nice.
1264                 */
1265                if (spec.field_width == -1)
1266                        spec.field_width = default_width;
1267                return string(buf, end, "(null)", spec);
1268        }
1269
1270        switch (*fmt) {
1271        case 'F':
1272        case 'f':
1273                ptr = dereference_function_descriptor(ptr);
1274                /* Fallthrough */
1275        case 'S':
1276        case 's':
1277        case 'B':
1278                return symbol_string(buf, end, ptr, spec, fmt);
1279        case 'R':
1280        case 'r':
1281                return resource_string(buf, end, ptr, spec, fmt);
1282        case 'h':
1283                return hex_string(buf, end, ptr, spec, fmt);
1284        case 'M':                       /* Colon separated: 00:01:02:03:04:05 */
1285        case 'm':                       /* Contiguous: 000102030405 */
1286                                        /* [mM]F (FDDI) */
1287                                        /* [mM]R (Reverse order; Bluetooth) */
1288                return mac_address_string(buf, end, ptr, spec, fmt);
1289        case 'I':                       /* Formatted IP supported
1290                                         * 4:   1.2.3.4
1291                                         * 6:   0001:0203:...:0708
1292                                         * 6c:  1::708 or 1::1.2.3.4
1293                                         */
1294        case 'i':                       /* Contiguous:
1295                                         * 4:   001.002.003.004
1296                                         * 6:   000102...0f
1297                                         */
1298                switch (fmt[1]) {
1299                case '6':
1300                        return ip6_addr_string(buf, end, ptr, spec, fmt);
1301                case '4':
1302                        return ip4_addr_string(buf, end, ptr, spec, fmt);
1303                case 'S': {
1304                        const union {
1305                                struct sockaddr         raw;
1306                                struct sockaddr_in      v4;
1307                                struct sockaddr_in6     v6;
1308                        } *sa = ptr;
1309
1310                        switch (sa->raw.sa_family) {
1311                        case AF_INET:
1312                                return ip4_addr_string_sa(buf, end, &sa->v4, spec, fmt);
1313                        case AF_INET6:
1314                                return ip6_addr_string_sa(buf, end, &sa->v6, spec, fmt);
1315                        default:
1316                                return string(buf, end, "(invalid address)", spec);
1317                        }}
1318                }
1319                break;
1320        case 'U':
1321                return uuid_string(buf, end, ptr, spec, fmt);
1322        case 'V':
1323                {
1324                        va_list va;
1325
1326                        va_copy(va, *((struct va_format *)ptr)->va);
1327                        buf += vsnprintf(buf, end > buf ? end - buf : 0,
1328                                         ((struct va_format *)ptr)->fmt, va);
1329                        va_end(va);
1330                        return buf;
1331                }
1332        case 'K':
1333                /*
1334                 * %pK cannot be used in IRQ context because its test
1335                 * for CAP_SYSLOG would be meaningless.
1336                 */
1337                if (kptr_restrict && (in_irq() || in_serving_softirq() ||
1338                                      in_nmi())) {
1339                        if (spec.field_width == -1)
1340                                spec.field_width = default_width;
1341                        return string(buf, end, "pK-error", spec);
1342                }
1343
1344                switch (kptr_restrict) {
1345                case 0:
1346                        /* Always print %pK values */
1347                        break;
1348                case 1: {
1349                        /*
1350                         * Only print the real pointer value if the current
1351                         * process has CAP_SYSLOG and is running with the
1352                         * same credentials it started with. This is because
1353                         * access to files is checked at open() time, but %pK
1354                         * checks permission at read() time. We don't want to
1355                         * leak pointer values if a binary opens a file using
1356                         * %pK and then elevates privileges before reading it.
1357                         */
1358                        const struct cred *cred = current_cred();
1359
1360                        if (!has_capability_noaudit(current, CAP_SYSLOG) ||
1361                            !uid_eq(cred->euid, cred->uid) ||
1362                            !gid_eq(cred->egid, cred->gid))
1363                                ptr = NULL;
1364                        break;
1365                }
1366                case 2:
1367                default:
1368                        /* Always print 0's for %pK */
1369                        ptr = NULL;
1370                        break;
1371                }
1372                break;
1373
1374        case 'N':
1375                switch (fmt[1]) {
1376                case 'F':
1377                        return netdev_feature_string(buf, end, ptr, spec);
1378                }
1379                break;
1380        case 'a':
1381                return address_val(buf, end, ptr, spec, fmt);
1382        case 'd':
1383                return dentry_name(buf, end, ptr, spec, fmt);
1384        case 'D':
1385                return dentry_name(buf, end,
1386                                   ((const struct file *)ptr)->f_path.dentry,
1387                                   spec, fmt);
1388        }
1389        spec.flags |= SMALL;
1390        if (spec.field_width == -1) {
1391                spec.field_width = default_width;
1392                spec.flags |= ZEROPAD;
1393        }
1394        spec.base = 16;
1395
1396        return number(buf, end, (unsigned long) ptr, spec);
1397}
1398
1399/*
1400 * Helper function to decode printf style format.
1401 * Each call decode a token from the format and return the
1402 * number of characters read (or likely the delta where it wants
1403 * to go on the next call).
1404 * The decoded token is returned through the parameters
1405 *
1406 * 'h', 'l', or 'L' for integer fields
1407 * 'z' support added 23/7/1999 S.H.
1408 * 'z' changed to 'Z' --davidm 1/25/99
1409 * 't' added for ptrdiff_t
1410 *
1411 * @fmt: the format string
1412 * @type of the token returned
1413 * @flags: various flags such as +, -, # tokens..
1414 * @field_width: overwritten width
1415 * @base: base of the number (octal, hex, ...)
1416 * @precision: precision of a number
1417 * @qualifier: qualifier of a number (long, size_t, ...)
1418 */
1419static noinline_for_stack
1420int format_decode(const char *fmt, struct printf_spec *spec)
1421{
1422        const char *start = fmt;
1423
1424        /* we finished early by reading the field width */
1425        if (spec->type == FORMAT_TYPE_WIDTH) {
1426                if (spec->field_width < 0) {
1427                        spec->field_width = -spec->field_width;
1428                        spec->flags |= LEFT;
1429                }
1430                spec->type = FORMAT_TYPE_NONE;
1431                goto precision;
1432        }
1433
1434        /* we finished early by reading the precision */
1435        if (spec->type == FORMAT_TYPE_PRECISION) {
1436                if (spec->precision < 0)
1437                        spec->precision = 0;
1438
1439                spec->type = FORMAT_TYPE_NONE;
1440                goto qualifier;
1441        }
1442
1443        /* By default */
1444        spec->type = FORMAT_TYPE_NONE;
1445
1446        for (; *fmt ; ++fmt) {
1447                if (*fmt == '%')
1448                        break;
1449        }
1450
1451        /* Return the current non-format string */
1452        if (fmt != start || !*fmt)
1453                return fmt - start;
1454
1455        /* Process flags */
1456        spec->flags = 0;
1457
1458        while (1) { /* this also skips first '%' */
1459                bool found = true;
1460
1461                ++fmt;
1462
1463                switch (*fmt) {
1464                case '-': spec->flags |= LEFT;    break;
1465                case '+': spec->flags |= PLUS;    break;
1466                case ' ': spec->flags |= SPACE;   break;
1467                case '#': spec->flags |= SPECIAL; break;
1468                case '0': spec->flags |= ZEROPAD; break;
1469                default:  found = false;
1470                }
1471
1472                if (!found)
1473                        break;
1474        }
1475
1476        /* get field width */
1477        spec->field_width = -1;
1478
1479        if (isdigit(*fmt))
1480                spec->field_width = skip_atoi(&fmt);
1481        else if (*fmt == '*') {
1482                /* it's the next argument */
1483                spec->type = FORMAT_TYPE_WIDTH;
1484                return ++fmt - start;
1485        }
1486
1487precision:
1488        /* get the precision */
1489        spec->precision = -1;
1490        if (*fmt == '.') {
1491                ++fmt;
1492                if (isdigit(*fmt)) {
1493                        spec->precision = skip_atoi(&fmt);
1494                        if (spec->precision < 0)
1495                                spec->precision = 0;
1496                } else if (*fmt == '*') {
1497                        /* it's the next argument */
1498                        spec->type = FORMAT_TYPE_PRECISION;
1499                        return ++fmt - start;
1500                }
1501        }
1502
1503qualifier:
1504        /* get the conversion qualifier */
1505        spec->qualifier = -1;
1506        if (*fmt == 'h' || _tolower(*fmt) == 'l' ||
1507            _tolower(*fmt) == 'z' || *fmt == 't') {
1508                spec->qualifier = *fmt++;
1509                if (unlikely(spec->qualifier == *fmt)) {
1510                        if (spec->qualifier == 'l') {
1511                                spec->qualifier = 'L';
1512                                ++fmt;
1513                        } else if (spec->qualifier == 'h') {
1514                                spec->qualifier = 'H';
1515                                ++fmt;
1516                        }
1517                }
1518        }
1519
1520        /* default base */
1521        spec->base = 10;
1522        switch (*fmt) {
1523        case 'c':
1524                spec->type = FORMAT_TYPE_CHAR;
1525                return ++fmt - start;
1526
1527        case 's':
1528                spec->type = FORMAT_TYPE_STR;
1529                return ++fmt - start;
1530
1531        case 'p':
1532                spec->type = FORMAT_TYPE_PTR;
1533                return fmt - start;
1534                /* skip alnum */
1535
1536        case 'n':
1537                spec->type = FORMAT_TYPE_NRCHARS;
1538                return ++fmt - start;
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        default:
1563                spec->type = FORMAT_TYPE_INVALID;
1564                return fmt - start;
1565        }
1566
1567        if (spec->qualifier == 'L')
1568                spec->type = FORMAT_TYPE_LONG_LONG;
1569        else if (spec->qualifier == 'l') {
1570                if (spec->flags & SIGN)
1571                        spec->type = FORMAT_TYPE_LONG;
1572                else
1573                        spec->type = FORMAT_TYPE_ULONG;
1574        } else if (_tolower(spec->qualifier) == 'z') {
1575                spec->type = FORMAT_TYPE_SIZE_T;
1576        } else if (spec->qualifier == 't') {
1577                spec->type = FORMAT_TYPE_PTRDIFF;
1578        } else if (spec->qualifier == 'H') {
1579                if (spec->flags & SIGN)
1580                        spec->type = FORMAT_TYPE_BYTE;
1581                else
1582                        spec->type = FORMAT_TYPE_UBYTE;
1583        } else if (spec->qualifier == 'h') {
1584                if (spec->flags & SIGN)
1585                        spec->type = FORMAT_TYPE_SHORT;
1586                else
1587                        spec->type = FORMAT_TYPE_USHORT;
1588        } else {
1589                if (spec->flags & SIGN)
1590                        spec->type = FORMAT_TYPE_INT;
1591                else
1592                        spec->type = FORMAT_TYPE_UINT;
1593        }
1594
1595        return ++fmt - start;
1596}
1597
1598/**
1599 * vsnprintf - Format a string and place it in a buffer
1600 * @buf: The buffer to place the result into
1601 * @size: The size of the buffer, including the trailing null space
1602 * @fmt: The format string to use
1603 * @args: Arguments for the format string
1604 *
1605 * This function follows C99 vsnprintf, but has some extensions:
1606 * %pS output the name of a text symbol with offset
1607 * %ps output the name of a text symbol without offset
1608 * %pF output the name of a function pointer with its offset
1609 * %pf output the name of a function pointer without its offset
1610 * %pB output the name of a backtrace symbol with its offset
1611 * %pR output the address range in a struct resource with decoded flags
1612 * %pr output the address range in a struct resource with raw flags
1613 * %pM output a 6-byte MAC address with colons
1614 * %pMR output a 6-byte MAC address with colons in reversed order
1615 * %pMF output a 6-byte MAC address with dashes
1616 * %pm output a 6-byte MAC address without colons
1617 * %pmR output a 6-byte MAC address without colons in reversed order
1618 * %pI4 print an IPv4 address without leading zeros
1619 * %pi4 print an IPv4 address with leading zeros
1620 * %pI6 print an IPv6 address with colons
1621 * %pi6 print an IPv6 address without colons
1622 * %pI6c print an IPv6 address as specified by RFC 5952
1623 * %pIS depending on sa_family of 'struct sockaddr *' print IPv4/IPv6 address
1624 * %piS depending on sa_family of 'struct sockaddr *' print IPv4/IPv6 address
1625 * %pU[bBlL] print a UUID/GUID in big or little endian using lower or upper
1626 *   case.
1627 * %*ph[CDN] a variable-length hex string with a separator (supports up to 64
1628 *           bytes of the input)
1629 * %n is ignored
1630 *
1631 * ** Please update Documentation/printk-formats.txt when making changes **
1632 *
1633 * The return value is the number of characters which would
1634 * be generated for the given input, excluding the trailing
1635 * '\0', as per ISO C99. If you want to have the exact
1636 * number of characters written into @buf as return value
1637 * (not including the trailing '\0'), use vscnprintf(). If the
1638 * return is greater than or equal to @size, the resulting
1639 * string is truncated.
1640 *
1641 * If you're not already dealing with a va_list consider using snprintf().
1642 */
1643int vsnprintf(char *buf, size_t size, const char *fmt, va_list args)
1644{
1645        unsigned long long num;
1646        char *str, *end;
1647        struct printf_spec spec = {0};
1648
1649        /* Reject out-of-range values early.  Large positive sizes are
1650           used for unknown buffer sizes. */
1651        if (WARN_ON_ONCE((int) size < 0))
1652                return 0;
1653
1654        str = buf;
1655        end = buf + size;
1656
1657        /* Make sure end is always >= buf */
1658        if (end < buf) {
1659                end = ((void *)-1);
1660                size = end - buf;
1661        }
1662
1663        while (*fmt) {
1664                const char *old_fmt = fmt;
1665                int read = format_decode(fmt, &spec);
1666
1667                fmt += read;
1668
1669                switch (spec.type) {
1670                case FORMAT_TYPE_NONE: {
1671                        int copy = read;
1672                        if (str < end) {
1673                                if (copy > end - str)
1674                                        copy = end - str;
1675                                memcpy(str, old_fmt, copy);
1676                        }
1677                        str += read;
1678                        break;
1679                }
1680
1681                case FORMAT_TYPE_WIDTH:
1682                        spec.field_width = va_arg(args, int);
1683                        break;
1684
1685                case FORMAT_TYPE_PRECISION:
1686                        spec.precision = va_arg(args, int);
1687                        break;
1688
1689                case FORMAT_TYPE_CHAR: {
1690                        char c;
1691
1692                        if (!(spec.flags & LEFT)) {
1693                                while (--spec.field_width > 0) {
1694                                        if (str < end)
1695                                                *str = ' ';
1696                                        ++str;
1697
1698                                }
1699                        }
1700                        c = (unsigned char) va_arg(args, int);
1701                        if (str < end)
1702                                *str = c;
1703                        ++str;
1704                        while (--spec.field_width > 0) {
1705                                if (str < end)
1706                                        *str = ' ';
1707                                ++str;
1708                        }
1709                        break;
1710                }
1711
1712                case FORMAT_TYPE_STR:
1713                        str = string(str, end, va_arg(args, char *), spec);
1714                        break;
1715
1716                case FORMAT_TYPE_PTR:
1717                        str = pointer(fmt+1, str, end, va_arg(args, void *),
1718                                      spec);
1719                        while (isalnum(*fmt))
1720                                fmt++;
1721                        break;
1722
1723                case FORMAT_TYPE_PERCENT_CHAR:
1724                        if (str < end)
1725                                *str = '%';
1726                        ++str;
1727                        break;
1728
1729                case FORMAT_TYPE_INVALID:
1730                        if (str < end)
1731                                *str = '%';
1732                        ++str;
1733                        break;
1734
1735                case FORMAT_TYPE_NRCHARS: {
1736                        /*
1737                         * Since %n poses a greater security risk than
1738                         * utility, ignore %n and skip its argument.
1739                         */
1740                        void *skip_arg;
1741
1742                        WARN_ONCE(1, "Please remove ignored %%n in '%s'\n",
1743                                        old_fmt);
1744
1745                        skip_arg = va_arg(args, void *);
1746                        break;
1747                }
1748
1749                default:
1750                        switch (spec.type) {
1751                        case FORMAT_TYPE_LONG_LONG:
1752                                num = va_arg(args, long long);
1753                                break;
1754                        case FORMAT_TYPE_ULONG:
1755                                num = va_arg(args, unsigned long);
1756                                break;
1757                        case FORMAT_TYPE_LONG:
1758                                num = va_arg(args, long);
1759                                break;
1760                        case FORMAT_TYPE_SIZE_T:
1761                                if (spec.flags & SIGN)
1762                                        num = va_arg(args, ssize_t);
1763                                else
1764                                        num = va_arg(args, size_t);
1765                                break;
1766                        case FORMAT_TYPE_PTRDIFF:
1767                                num = va_arg(args, ptrdiff_t);
1768                                break;
1769                        case FORMAT_TYPE_UBYTE:
1770                                num = (unsigned char) va_arg(args, int);
1771                                break;
1772                        case FORMAT_TYPE_BYTE:
1773                                num = (signed char) va_arg(args, int);
1774                                break;
1775                        case FORMAT_TYPE_USHORT:
1776                                num = (unsigned short) va_arg(args, int);
1777                                break;
1778                        case FORMAT_TYPE_SHORT:
1779                                num = (short) va_arg(args, int);
1780                                break;
1781                        case FORMAT_TYPE_INT:
1782                                num = (int) va_arg(args, int);
1783                                break;
1784                        default:
1785                                num = va_arg(args, unsigned int);
1786                        }
1787
1788                        str = number(str, end, num, spec);
1789                }
1790        }
1791
1792        if (size > 0) {
1793                if (str < end)
1794                        *str = '\0';
1795                else
1796                        end[-1] = '\0';
1797        }
1798
1799        /* the trailing null byte doesn't count towards the total */
1800        return str-buf;
1801
1802}
1803EXPORT_SYMBOL(vsnprintf);
1804
1805/**
1806 * vscnprintf - Format a string and place it in a buffer
1807 * @buf: The buffer to place the result into
1808 * @size: The size of the buffer, including the trailing null space
1809 * @fmt: The format string to use
1810 * @args: Arguments for the format string
1811 *
1812 * The return value is the number of characters which have been written into
1813 * the @buf not including the trailing '\0'. If @size is == 0 the function
1814 * returns 0.
1815 *
1816 * If you're not already dealing with a va_list consider using scnprintf().
1817 *
1818 * See the vsnprintf() documentation for format string extensions over C99.
1819 */
1820int vscnprintf(char *buf, size_t size, const char *fmt, va_list args)
1821{
1822        int i;
1823
1824        i = vsnprintf(buf, size, fmt, args);
1825
1826        if (likely(i < size))
1827                return i;
1828        if (size != 0)
1829                return size - 1;
1830        return 0;
1831}
1832EXPORT_SYMBOL(vscnprintf);
1833
1834/**
1835 * snprintf - Format a string and place it in a buffer
1836 * @buf: The buffer to place the result into
1837 * @size: The size of the buffer, including the trailing null space
1838 * @fmt: The format string to use
1839 * @...: Arguments for the format string
1840 *
1841 * The return value is the number of characters which would be
1842 * generated for the given input, excluding the trailing null,
1843 * as per ISO C99.  If the return is greater than or equal to
1844 * @size, the resulting string is truncated.
1845 *
1846 * See the vsnprintf() documentation for format string extensions over C99.
1847 */
1848int snprintf(char *buf, size_t size, const char *fmt, ...)
1849{
1850        va_list args;
1851        int i;
1852
1853        va_start(args, fmt);
1854        i = vsnprintf(buf, size, fmt, args);
1855        va_end(args);
1856
1857        return i;
1858}
1859EXPORT_SYMBOL(snprintf);
1860
1861/**
1862 * scnprintf - Format a string and place it in a buffer
1863 * @buf: The buffer to place the result into
1864 * @size: The size of the buffer, including the trailing null space
1865 * @fmt: The format string to use
1866 * @...: Arguments for the format string
1867 *
1868 * The return value is the number of characters written into @buf not including
1869 * the trailing '\0'. If @size is == 0 the function returns 0.
1870 */
1871
1872int scnprintf(char *buf, size_t size, const char *fmt, ...)
1873{
1874        va_list args;
1875        int i;
1876
1877        va_start(args, fmt);
1878        i = vscnprintf(buf, size, fmt, args);
1879        va_end(args);
1880
1881        return i;
1882}
1883EXPORT_SYMBOL(scnprintf);
1884
1885/**
1886 * vsprintf - Format a string and place it in a buffer
1887 * @buf: The buffer to place the result into
1888 * @fmt: The format string to use
1889 * @args: Arguments for the format string
1890 *
1891 * The function returns the number of characters written
1892 * into @buf. Use vsnprintf() or vscnprintf() in order to avoid
1893 * buffer overflows.
1894 *
1895 * If you're not already dealing with a va_list consider using sprintf().
1896 *
1897 * See the vsnprintf() documentation for format string extensions over C99.
1898 */
1899int vsprintf(char *buf, const char *fmt, va_list args)
1900{
1901        return vsnprintf(buf, INT_MAX, fmt, args);
1902}
1903EXPORT_SYMBOL(vsprintf);
1904
1905/**
1906 * sprintf - Format a string and place it in a buffer
1907 * @buf: The buffer to place the result into
1908 * @fmt: The format string to use
1909 * @...: Arguments for the format string
1910 *
1911 * The function returns the number of characters written
1912 * into @buf. Use snprintf() or scnprintf() in order to avoid
1913 * buffer overflows.
1914 *
1915 * See the vsnprintf() documentation for format string extensions over C99.
1916 */
1917int sprintf(char *buf, const char *fmt, ...)
1918{
1919        va_list args;
1920        int i;
1921
1922        va_start(args, fmt);
1923        i = vsnprintf(buf, INT_MAX, fmt, args);
1924        va_end(args);
1925
1926        return i;
1927}
1928EXPORT_SYMBOL(sprintf);
1929
1930#ifdef CONFIG_BINARY_PRINTF
1931/*
1932 * bprintf service:
1933 * vbin_printf() - VA arguments to binary data
1934 * bstr_printf() - Binary data to text string
1935 */
1936
1937/**
1938 * vbin_printf - Parse a format string and place args' binary value in a buffer
1939 * @bin_buf: The buffer to place args' binary value
1940 * @size: The size of the buffer(by words(32bits), not characters)
1941 * @fmt: The format string to use
1942 * @args: Arguments for the format string
1943 *
1944 * The format follows C99 vsnprintf, except %n is ignored, and its argument
1945 * is skiped.
1946 *
1947 * The return value is the number of words(32bits) which would be generated for
1948 * the given input.
1949 *
1950 * NOTE:
1951 * If the return value is greater than @size, the resulting bin_buf is NOT
1952 * valid for bstr_printf().
1953 */
1954int vbin_printf(u32 *bin_buf, size_t size, const char *fmt, va_list args)
1955{
1956        struct printf_spec spec = {0};
1957        char *str, *end;
1958
1959        str = (char *)bin_buf;
1960        end = (char *)(bin_buf + size);
1961
1962#define save_arg(type)                                                  \
1963do {                                                                    \
1964        if (sizeof(type) == 8) {                                        \
1965                unsigned long long value;                               \
1966                str = PTR_ALIGN(str, sizeof(u32));                      \
1967                value = va_arg(args, unsigned long long);               \
1968                if (str + sizeof(type) <= end) {                        \
1969                        *(u32 *)str = *(u32 *)&value;                   \
1970                        *(u32 *)(str + 4) = *((u32 *)&value + 1);       \
1971                }                                                       \
1972        } else {                                                        \
1973                unsigned long value;                                    \
1974                str = PTR_ALIGN(str, sizeof(type));                     \
1975                value = va_arg(args, int);                              \
1976                if (str + sizeof(type) <= end)                          \
1977                        *(typeof(type) *)str = (type)value;             \
1978        }                                                               \
1979        str += sizeof(type);                                            \
1980} while (0)
1981
1982        while (*fmt) {
1983                int read = format_decode(fmt, &spec);
1984
1985                fmt += read;
1986
1987                switch (spec.type) {
1988                case FORMAT_TYPE_NONE:
1989                case FORMAT_TYPE_INVALID:
1990                case FORMAT_TYPE_PERCENT_CHAR:
1991                        break;
1992
1993                case FORMAT_TYPE_WIDTH:
1994                case FORMAT_TYPE_PRECISION:
1995                        save_arg(int);
1996                        break;
1997
1998                case FORMAT_TYPE_CHAR:
1999                        save_arg(char);
2000                        break;
2001
2002                case FORMAT_TYPE_STR: {
2003                        const char *save_str = va_arg(args, char *);
2004                        size_t len;
2005
2006                        if ((unsigned long)save_str > (unsigned long)-PAGE_SIZE
2007                                        || (unsigned long)save_str < PAGE_SIZE)
2008                                save_str = "(null)";
2009                        len = strlen(save_str) + 1;
2010                        if (str + len < end)
2011                                memcpy(str, save_str, len);
2012                        str += len;
2013                        break;
2014                }
2015
2016                case FORMAT_TYPE_PTR:
2017                        save_arg(void *);
2018                        /* skip all alphanumeric pointer suffixes */
2019                        while (isalnum(*fmt))
2020                                fmt++;
2021                        break;
2022
2023                case FORMAT_TYPE_NRCHARS: {
2024                        /* skip %n 's argument */
2025                        u8 qualifier = spec.qualifier;
2026                        void *skip_arg;
2027                        if (qualifier == 'l')
2028                                skip_arg = va_arg(args, long *);
2029                        else if (_tolower(qualifier) == 'z')
2030                                skip_arg = va_arg(args, size_t *);
2031                        else
2032                                skip_arg = va_arg(args, int *);
2033                        break;
2034                }
2035
2036                default:
2037                        switch (spec.type) {
2038
2039                        case FORMAT_TYPE_LONG_LONG:
2040                                save_arg(long long);
2041                                break;
2042                        case FORMAT_TYPE_ULONG:
2043                        case FORMAT_TYPE_LONG:
2044                                save_arg(unsigned long);
2045                                break;
2046                        case FORMAT_TYPE_SIZE_T:
2047                                save_arg(size_t);
2048                                break;
2049                        case FORMAT_TYPE_PTRDIFF:
2050                                save_arg(ptrdiff_t);
2051                                break;
2052                        case FORMAT_TYPE_UBYTE:
2053                        case FORMAT_TYPE_BYTE:
2054                                save_arg(char);
2055                                break;
2056                        case FORMAT_TYPE_USHORT:
2057                        case FORMAT_TYPE_SHORT:
2058                                save_arg(short);
2059                                break;
2060                        default:
2061                                save_arg(int);
2062                        }
2063                }
2064        }
2065
2066        return (u32 *)(PTR_ALIGN(str, sizeof(u32))) - bin_buf;
2067#undef save_arg
2068}
2069EXPORT_SYMBOL_GPL(vbin_printf);
2070
2071/**
2072 * bstr_printf - Format a string from binary arguments and place it in a buffer
2073 * @buf: The buffer to place the result into
2074 * @size: The size of the buffer, including the trailing null space
2075 * @fmt: The format string to use
2076 * @bin_buf: Binary arguments for the format string
2077 *
2078 * This function like C99 vsnprintf, but the difference is that vsnprintf gets
2079 * arguments from stack, and bstr_printf gets arguments from @bin_buf which is
2080 * a binary buffer that generated by vbin_printf.
2081 *
2082 * The format follows C99 vsnprintf, but has some extensions:
2083 *  see vsnprintf comment for details.
2084 *
2085 * The return value is the number of characters which would
2086 * be generated for the given input, excluding the trailing
2087 * '\0', as per ISO C99. If you want to have the exact
2088 * number of characters written into @buf as return value
2089 * (not including the trailing '\0'), use vscnprintf(). If the
2090 * return is greater than or equal to @size, the resulting
2091 * string is truncated.
2092 */
2093int bstr_printf(char *buf, size_t size, const char *fmt, const u32 *bin_buf)
2094{
2095        struct printf_spec spec = {0};
2096        char *str, *end;
2097        const char *args = (const char *)bin_buf;
2098
2099        if (WARN_ON_ONCE((int) size < 0))
2100                return 0;
2101
2102        str = buf;
2103        end = buf + size;
2104
2105#define get_arg(type)                                                   \
2106({                                                                      \
2107        typeof(type) value;                                             \
2108        if (sizeof(type) == 8) {                                        \
2109                args = PTR_ALIGN(args, sizeof(u32));                    \
2110                *(u32 *)&value = *(u32 *)args;                          \
2111                *((u32 *)&value + 1) = *(u32 *)(args + 4);              \
2112        } else {                                                        \
2113                args = PTR_ALIGN(args, sizeof(type));                   \
2114                value = *(typeof(type) *)args;                          \
2115        }                                                               \
2116        args += sizeof(type);                                           \
2117        value;                                                          \
2118})
2119
2120        /* Make sure end is always >= buf */
2121        if (end < buf) {
2122                end = ((void *)-1);
2123                size = end - buf;
2124        }
2125
2126        while (*fmt) {
2127                const char *old_fmt = fmt;
2128                int read = format_decode(fmt, &spec);
2129
2130                fmt += read;
2131
2132                switch (spec.type) {
2133                case FORMAT_TYPE_NONE: {
2134                        int copy = read;
2135                        if (str < end) {
2136                                if (copy > end - str)
2137                                        copy = end - str;
2138                                memcpy(str, old_fmt, copy);
2139                        }
2140                        str += read;
2141                        break;
2142                }
2143
2144                case FORMAT_TYPE_WIDTH:
2145                        spec.field_width = get_arg(int);
2146                        break;
2147
2148                case FORMAT_TYPE_PRECISION:
2149                        spec.precision = get_arg(int);
2150                        break;
2151
2152                case FORMAT_TYPE_CHAR: {
2153                        char c;
2154
2155                        if (!(spec.flags & LEFT)) {
2156                                while (--spec.field_width > 0) {
2157                                        if (str < end)
2158                                                *str = ' ';
2159                                        ++str;
2160                                }
2161                        }
2162                        c = (unsigned char) get_arg(char);
2163                        if (str < end)
2164                                *str = c;
2165                        ++str;
2166                        while (--spec.field_width > 0) {
2167                                if (str < end)
2168                                        *str = ' ';
2169                                ++str;
2170                        }
2171                        break;
2172                }
2173
2174                case FORMAT_TYPE_STR: {
2175                        const char *str_arg = args;
2176                        args += strlen(str_arg) + 1;
2177                        str = string(str, end, (char *)str_arg, spec);
2178                        break;
2179                }
2180
2181                case FORMAT_TYPE_PTR:
2182                        str = pointer(fmt+1, str, end, get_arg(void *), spec);
2183                        while (isalnum(*fmt))
2184                                fmt++;
2185                        break;
2186
2187                case FORMAT_TYPE_PERCENT_CHAR:
2188                case FORMAT_TYPE_INVALID:
2189                        if (str < end)
2190                                *str = '%';
2191                        ++str;
2192                        break;
2193
2194                case FORMAT_TYPE_NRCHARS:
2195                        /* skip */
2196                        break;
2197
2198                default: {
2199                        unsigned long long num;
2200
2201                        switch (spec.type) {
2202
2203                        case FORMAT_TYPE_LONG_LONG:
2204                                num = get_arg(long long);
2205                                break;
2206                        case FORMAT_TYPE_ULONG:
2207                        case FORMAT_TYPE_LONG:
2208                                num = get_arg(unsigned long);
2209                                break;
2210                        case FORMAT_TYPE_SIZE_T:
2211                                num = get_arg(size_t);
2212                                break;
2213                        case FORMAT_TYPE_PTRDIFF:
2214                                num = get_arg(ptrdiff_t);
2215                                break;
2216                        case FORMAT_TYPE_UBYTE:
2217                                num = get_arg(unsigned char);
2218                                break;
2219                        case FORMAT_TYPE_BYTE:
2220                                num = get_arg(signed char);
2221                                break;
2222                        case FORMAT_TYPE_USHORT:
2223                                num = get_arg(unsigned short);
2224                                break;
2225                        case FORMAT_TYPE_SHORT:
2226                                num = get_arg(short);
2227                                break;
2228                        case FORMAT_TYPE_UINT:
2229                                num = get_arg(unsigned int);
2230                                break;
2231                        default:
2232                                num = get_arg(int);
2233                        }
2234
2235                        str = number(str, end, num, spec);
2236                } /* default: */
2237                } /* switch(spec.type) */
2238        } /* while(*fmt) */
2239
2240        if (size > 0) {
2241                if (str < end)
2242                        *str = '\0';
2243                else
2244                        end[-1] = '\0';
2245        }
2246
2247#undef get_arg
2248
2249        /* the trailing null byte doesn't count towards the total */
2250        return str - buf;
2251}
2252EXPORT_SYMBOL_GPL(bstr_printf);
2253
2254/**
2255 * bprintf - Parse a format string and place args' binary value in a buffer
2256 * @bin_buf: The buffer to place args' binary value
2257 * @size: The size of the buffer(by words(32bits), not characters)
2258 * @fmt: The format string to use
2259 * @...: Arguments for the format string
2260 *
2261 * The function returns the number of words(u32) written
2262 * into @bin_buf.
2263 */
2264int bprintf(u32 *bin_buf, size_t size, const char *fmt, ...)
2265{
2266        va_list args;
2267        int ret;
2268
2269        va_start(args, fmt);
2270        ret = vbin_printf(bin_buf, size, fmt, args);
2271        va_end(args);
2272
2273        return ret;
2274}
2275EXPORT_SYMBOL_GPL(bprintf);
2276
2277#endif /* CONFIG_BINARY_PRINTF */
2278
2279/**
2280 * vsscanf - Unformat a buffer into a list of arguments
2281 * @buf:        input buffer
2282 * @fmt:        format of buffer
2283 * @args:       arguments
2284 */
2285int vsscanf(const char *buf, const char *fmt, va_list args)
2286{
2287        const char *str = buf;
2288        char *next;
2289        char digit;
2290        int num = 0;
2291        u8 qualifier;
2292        unsigned int base;
2293        union {
2294                long long s;
2295                unsigned long long u;
2296        } val;
2297        s16 field_width;
2298        bool is_sign;
2299
2300        while (*fmt) {
2301                /* skip any white space in format */
2302                /* white space in format matchs any amount of
2303                 * white space, including none, in the input.
2304                 */
2305                if (isspace(*fmt)) {
2306                        fmt = skip_spaces(++fmt);
2307                        str = skip_spaces(str);
2308                }
2309
2310                /* anything that is not a conversion must match exactly */
2311                if (*fmt != '%' && *fmt) {
2312                        if (*fmt++ != *str++)
2313                                break;
2314                        continue;
2315                }
2316
2317                if (!*fmt)
2318                        break;
2319                ++fmt;
2320
2321                /* skip this conversion.
2322                 * advance both strings to next white space
2323                 */
2324                if (*fmt == '*') {
2325                        if (!*str)
2326                                break;
2327                        while (!isspace(*fmt) && *fmt != '%' && *fmt)
2328                                fmt++;
2329                        while (!isspace(*str) && *str)
2330                                str++;
2331                        continue;
2332                }
2333
2334                /* get field width */
2335                field_width = -1;
2336                if (isdigit(*fmt)) {
2337                        field_width = skip_atoi(&fmt);
2338                        if (field_width <= 0)
2339                                break;
2340                }
2341
2342                /* get conversion qualifier */
2343                qualifier = -1;
2344                if (*fmt == 'h' || _tolower(*fmt) == 'l' ||
2345                    _tolower(*fmt) == 'z') {
2346                        qualifier = *fmt++;
2347                        if (unlikely(qualifier == *fmt)) {
2348                                if (qualifier == 'h') {
2349                                        qualifier = 'H';
2350                                        fmt++;
2351                                } else if (qualifier == 'l') {
2352                                        qualifier = 'L';
2353                                        fmt++;
2354                                }
2355                        }
2356                }
2357
2358                if (!*fmt)
2359                        break;
2360
2361                if (*fmt == 'n') {
2362                        /* return number of characters read so far */
2363                        *va_arg(args, int *) = str - buf;
2364                        ++fmt;
2365                        continue;
2366                }
2367
2368                if (!*str)
2369                        break;
2370
2371                base = 10;
2372                is_sign = 0;
2373
2374                switch (*fmt++) {
2375                case 'c':
2376                {
2377                        char *s = (char *)va_arg(args, char*);
2378                        if (field_width == -1)
2379                                field_width = 1;
2380                        do {
2381                                *s++ = *str++;
2382                        } while (--field_width > 0 && *str);
2383                        num++;
2384                }
2385                continue;
2386                case 's':
2387                {
2388                        char *s = (char *)va_arg(args, char *);
2389                        if (field_width == -1)
2390                                field_width = SHRT_MAX;
2391                        /* first, skip leading white space in buffer */
2392                        str = skip_spaces(str);
2393
2394                        /* now copy until next white space */
2395                        while (*str && !isspace(*str) && field_width--)
2396                                *s++ = *str++;
2397                        *s = '\0';
2398                        num++;
2399                }
2400                continue;
2401                case 'o':
2402                        base = 8;
2403                        break;
2404                case 'x':
2405                case 'X':
2406                        base = 16;
2407                        break;
2408                case 'i':
2409                        base = 0;
2410                case 'd':
2411                        is_sign = 1;
2412                case 'u':
2413                        break;
2414                case '%':
2415                        /* looking for '%' in str */
2416                        if (*str++ != '%')
2417                                return num;
2418                        continue;
2419                default:
2420                        /* invalid format; stop here */
2421                        return num;
2422                }
2423
2424                /* have some sort of integer conversion.
2425                 * first, skip white space in buffer.
2426                 */
2427                str = skip_spaces(str);
2428
2429                digit = *str;
2430                if (is_sign && digit == '-')
2431                        digit = *(str + 1);
2432
2433                if (!digit
2434                    || (base == 16 && !isxdigit(digit))
2435                    || (base == 10 && !isdigit(digit))
2436                    || (base == 8 && (!isdigit(digit) || digit > '7'))
2437                    || (base == 0 && !isdigit(digit)))
2438                        break;
2439
2440                if (is_sign)
2441                        val.s = qualifier != 'L' ?
2442                                simple_strtol(str, &next, base) :
2443                                simple_strtoll(str, &next, base);
2444                else
2445                        val.u = qualifier != 'L' ?
2446                                simple_strtoul(str, &next, base) :
2447                                simple_strtoull(str, &next, base);
2448
2449                if (field_width > 0 && next - str > field_width) {
2450                        if (base == 0)
2451                                _parse_integer_fixup_radix(str, &base);
2452                        while (next - str > field_width) {
2453                                if (is_sign)
2454                                        val.s = div_s64(val.s, base);
2455                                else
2456                                        val.u = div_u64(val.u, base);
2457                                --next;
2458                        }
2459                }
2460
2461                switch (qualifier) {
2462                case 'H':       /* that's 'hh' in format */
2463                        if (is_sign)
2464                                *va_arg(args, signed char *) = val.s;
2465                        else
2466                                *va_arg(args, unsigned char *) = val.u;
2467                        break;
2468                case 'h':
2469                        if (is_sign)
2470                                *va_arg(args, short *) = val.s;
2471                        else
2472                                *va_arg(args, unsigned short *) = val.u;
2473                        break;
2474                case 'l':
2475                        if (is_sign)
2476                                *va_arg(args, long *) = val.s;
2477                        else
2478                                *va_arg(args, unsigned long *) = val.u;
2479                        break;
2480                case 'L':
2481                        if (is_sign)
2482                                *va_arg(args, long long *) = val.s;
2483                        else
2484                                *va_arg(args, unsigned long long *) = val.u;
2485                        break;
2486                case 'Z':
2487                case 'z':
2488                        *va_arg(args, size_t *) = val.u;
2489                        break;
2490                default:
2491                        if (is_sign)
2492                                *va_arg(args, int *) = val.s;
2493                        else
2494                                *va_arg(args, unsigned int *) = val.u;
2495                        break;
2496                }
2497                num++;
2498
2499                if (!next)
2500                        break;
2501                str = next;
2502        }
2503
2504        return num;
2505}
2506EXPORT_SYMBOL(vsscanf);
2507
2508/**
2509 * sscanf - Unformat a buffer into a list of arguments
2510 * @buf:        input buffer
2511 * @fmt:        formatting of buffer
2512 * @...:        resulting arguments
2513 */
2514int sscanf(const char *buf, const char *fmt, ...)
2515{
2516        va_list args;
2517        int i;
2518
2519        va_start(args, fmt);
2520        i = vsscanf(buf, fmt, args);
2521        va_end(args);
2522
2523        return i;
2524}
2525EXPORT_SYMBOL(sscanf);
2526
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