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/clk.h>
  21#include <linux/clk-provider.h>
  22#include <linux/module.h>       /* for KSYM_SYMBOL_LEN */
  23#include <linux/types.h>
  24#include <linux/string.h>
  25#include <linux/ctype.h>
  26#include <linux/kernel.h>
  27#include <linux/kallsyms.h>
  28#include <linux/math64.h>
  29#include <linux/uaccess.h>
  30#include <linux/ioport.h>
  31#include <linux/dcache.h>
  32#include <linux/cred.h>
  33#include <linux/uuid.h>
  34#include <linux/of.h>
  35#include <net/addrconf.h>
  36#ifdef CONFIG_BLOCK
  37#include <linux/blkdev.h>
  38#endif
  39
  40#include "../mm/internal.h"     /* For the trace_print_flags arrays */
  41
  42#include <asm/page.h>           /* for PAGE_SIZE */
  43#include <asm/sections.h>       /* for dereference_function_descriptor() */
  44#include <asm/byteorder.h>      /* cpu_to_le16 */
  45
  46#include <linux/string_helpers.h>
  47#include "kstrtox.h"
  48
  49/**
  50 * simple_strtoull - convert a string to an unsigned long long
  51 * @cp: The start of the string
  52 * @endp: A pointer to the end of the parsed string will be placed here
  53 * @base: The number base to use
  54 *
  55 * This function is obsolete. Please use kstrtoull instead.
  56 */
  57unsigned long long simple_strtoull(const char *cp, char **endp, unsigned int base)
  58{
  59        unsigned long long result;
  60        unsigned int rv;
  61
  62        cp = _parse_integer_fixup_radix(cp, &base);
  63        rv = _parse_integer(cp, base, &result);
  64        /* FIXME */
  65        cp += (rv & ~KSTRTOX_OVERFLOW);
  66
  67        if (endp)
  68                *endp = (char *)cp;
  69
  70        return result;
  71}
  72EXPORT_SYMBOL(simple_strtoull);
  73
  74/**
  75 * simple_strtoul - convert a string to an unsigned long
  76 * @cp: The start of the string
  77 * @endp: A pointer to the end of the parsed string will be placed here
  78 * @base: The number base to use
  79 *
  80 * This function is obsolete. Please use kstrtoul instead.
  81 */
  82unsigned long simple_strtoul(const char *cp, char **endp, unsigned int base)
  83{
  84        return simple_strtoull(cp, endp, base);
  85}
  86EXPORT_SYMBOL(simple_strtoul);
  87
  88/**
  89 * simple_strtol - convert a string to a signed long
  90 * @cp: The start of the string
  91 * @endp: A pointer to the end of the parsed string will be placed here
  92 * @base: The number base to use
  93 *
  94 * This function is obsolete. Please use kstrtol instead.
  95 */
  96long simple_strtol(const char *cp, char **endp, unsigned int base)
  97{
  98        if (*cp == '-')
  99                return -simple_strtoul(cp + 1, endp, base);
 100
 101        return simple_strtoul(cp, endp, base);
 102}
 103EXPORT_SYMBOL(simple_strtol);
 104
 105/**
 106 * simple_strtoll - convert a string to a signed long long
 107 * @cp: The start of the string
 108 * @endp: A pointer to the end of the parsed string will be placed here
 109 * @base: The number base to use
 110 *
 111 * This function is obsolete. Please use kstrtoll instead.
 112 */
 113long long simple_strtoll(const char *cp, char **endp, unsigned int base)
 114{
 115        if (*cp == '-')
 116                return -simple_strtoull(cp + 1, endp, base);
 117
 118        return simple_strtoull(cp, endp, base);
 119}
 120EXPORT_SYMBOL(simple_strtoll);
 121
 122static noinline_for_stack
 123int skip_atoi(const char **s)
 124{
 125        int i = 0;
 126
 127        do {
 128                i = i*10 + *((*s)++) - '0';
 129        } while (isdigit(**s));
 130
 131        return i;
 132}
 133
 134/*
 135 * Decimal conversion is by far the most typical, and is used for
 136 * /proc and /sys data. This directly impacts e.g. top performance
 137 * with many processes running. We optimize it for speed by emitting
 138 * two characters at a time, using a 200 byte lookup table. This
 139 * roughly halves the number of multiplications compared to computing
 140 * the digits one at a time. Implementation strongly inspired by the
 141 * previous version, which in turn used ideas described at
 142 * <http://www.cs.uiowa.edu/~jones/bcd/divide.html> (with permission
 143 * from the author, Douglas W. Jones).
 144 *
 145 * It turns out there is precisely one 26 bit fixed-point
 146 * approximation a of 64/100 for which x/100 == (x * (u64)a) >> 32
 147 * holds for all x in [0, 10^8-1], namely a = 0x28f5c29. The actual
 148 * range happens to be somewhat larger (x <= 1073741898), but that's
 149 * irrelevant for our purpose.
 150 *
 151 * For dividing a number in the range [10^4, 10^6-1] by 100, we still
 152 * need a 32x32->64 bit multiply, so we simply use the same constant.
 153 *
 154 * For dividing a number in the range [100, 10^4-1] by 100, there are
 155 * several options. The simplest is (x * 0x147b) >> 19, which is valid
 156 * for all x <= 43698.
 157 */
 158
 159static const u16 decpair[100] = {
 160#define _(x) (__force u16) cpu_to_le16(((x % 10) | ((x / 10) << 8)) + 0x3030)
 161        _( 0), _( 1), _( 2), _( 3), _( 4), _( 5), _( 6), _( 7), _( 8), _( 9),
 162        _(10), _(11), _(12), _(13), _(14), _(15), _(16), _(17), _(18), _(19),
 163        _(20), _(21), _(22), _(23), _(24), _(25), _(26), _(27), _(28), _(29),
 164        _(30), _(31), _(32), _(33), _(34), _(35), _(36), _(37), _(38), _(39),
 165        _(40), _(41), _(42), _(43), _(44), _(45), _(46), _(47), _(48), _(49),
 166        _(50), _(51), _(52), _(53), _(54), _(55), _(56), _(57), _(58), _(59),
 167        _(60), _(61), _(62), _(63), _(64), _(65), _(66), _(67), _(68), _(69),
 168        _(70), _(71), _(72), _(73), _(74), _(75), _(76), _(77), _(78), _(79),
 169        _(80), _(81), _(82), _(83), _(84), _(85), _(86), _(87), _(88), _(89),
 170        _(90), _(91), _(92), _(93), _(94), _(95), _(96), _(97), _(98), _(99),
 171#undef _
 172};
 173
 174/*
 175 * This will print a single '0' even if r == 0, since we would
 176 * immediately jump to out_r where two 0s would be written but only
 177 * one of them accounted for in buf. This is needed by ip4_string
 178 * below. All other callers pass a non-zero value of r.
 179*/
 180static noinline_for_stack
 181char *put_dec_trunc8(char *buf, unsigned r)
 182{
 183        unsigned q;
 184
 185        /* 1 <= r < 10^8 */
 186        if (r < 100)
 187                goto out_r;
 188
 189        /* 100 <= r < 10^8 */
 190        q = (r * (u64)0x28f5c29) >> 32;
 191        *((u16 *)buf) = decpair[r - 100*q];
 192        buf += 2;
 193
 194        /* 1 <= q < 10^6 */
 195        if (q < 100)
 196                goto out_q;
 197
 198        /*  100 <= q < 10^6 */
 199        r = (q * (u64)0x28f5c29) >> 32;
 200        *((u16 *)buf) = decpair[q - 100*r];
 201        buf += 2;
 202
 203        /* 1 <= r < 10^4 */
 204        if (r < 100)
 205                goto out_r;
 206
 207        /* 100 <= r < 10^4 */
 208        q = (r * 0x147b) >> 19;
 209        *((u16 *)buf) = decpair[r - 100*q];
 210        buf += 2;
 211out_q:
 212        /* 1 <= q < 100 */
 213        r = q;
 214out_r:
 215        /* 1 <= r < 100 */
 216        *((u16 *)buf) = decpair[r];
 217        buf += r < 10 ? 1 : 2;
 218        return buf;
 219}
 220
 221#if BITS_PER_LONG == 64 && BITS_PER_LONG_LONG == 64
 222static noinline_for_stack
 223char *put_dec_full8(char *buf, unsigned r)
 224{
 225        unsigned q;
 226
 227        /* 0 <= r < 10^8 */
 228        q = (r * (u64)0x28f5c29) >> 32;
 229        *((u16 *)buf) = decpair[r - 100*q];
 230        buf += 2;
 231
 232        /* 0 <= q < 10^6 */
 233        r = (q * (u64)0x28f5c29) >> 32;
 234        *((u16 *)buf) = decpair[q - 100*r];
 235        buf += 2;
 236
 237        /* 0 <= r < 10^4 */
 238        q = (r * 0x147b) >> 19;
 239        *((u16 *)buf) = decpair[r - 100*q];
 240        buf += 2;
 241
 242        /* 0 <= q < 100 */
 243        *((u16 *)buf) = decpair[q];
 244        buf += 2;
 245        return buf;
 246}
 247
 248static noinline_for_stack
 249char *put_dec(char *buf, unsigned long long n)
 250{
 251        if (n >= 100*1000*1000)
 252                buf = put_dec_full8(buf, do_div(n, 100*1000*1000));
 253        /* 1 <= n <= 1.6e11 */
 254        if (n >= 100*1000*1000)
 255                buf = put_dec_full8(buf, do_div(n, 100*1000*1000));
 256        /* 1 <= n < 1e8 */
 257        return put_dec_trunc8(buf, n);
 258}
 259
 260#elif BITS_PER_LONG == 32 && BITS_PER_LONG_LONG == 64
 261
 262static void
 263put_dec_full4(char *buf, unsigned r)
 264{
 265        unsigned q;
 266
 267        /* 0 <= r < 10^4 */
 268        q = (r * 0x147b) >> 19;
 269        *((u16 *)buf) = decpair[r - 100*q];
 270        buf += 2;
 271        /* 0 <= q < 100 */
 272        *((u16 *)buf) = decpair[q];
 273}
 274
 275/*
 276 * Call put_dec_full4 on x % 10000, return x / 10000.
 277 * The approximation x/10000 == (x * 0x346DC5D7) >> 43
 278 * holds for all x < 1,128,869,999.  The largest value this
 279 * helper will ever be asked to convert is 1,125,520,955.
 280 * (second call in the put_dec code, assuming n is all-ones).
 281 */
 282static noinline_for_stack
 283unsigned put_dec_helper4(char *buf, unsigned x)
 284{
 285        uint32_t q = (x * (uint64_t)0x346DC5D7) >> 43;
 286
 287        put_dec_full4(buf, x - q * 10000);
 288        return q;
 289}
 290
 291/* Based on code by Douglas W. Jones found at
 292 * <http://www.cs.uiowa.edu/~jones/bcd/decimal.html#sixtyfour>
 293 * (with permission from the author).
 294 * Performs no 64-bit division and hence should be fast on 32-bit machines.
 295 */
 296static
 297char *put_dec(char *buf, unsigned long long n)
 298{
 299        uint32_t d3, d2, d1, q, h;
 300
 301        if (n < 100*1000*1000)
 302                return put_dec_trunc8(buf, n);
 303
 304        d1  = ((uint32_t)n >> 16); /* implicit "& 0xffff" */
 305        h   = (n >> 32);
 306        d2  = (h      ) & 0xffff;
 307        d3  = (h >> 16); /* implicit "& 0xffff" */
 308
 309        /* n = 2^48 d3 + 2^32 d2 + 2^16 d1 + d0
 310             = 281_4749_7671_0656 d3 + 42_9496_7296 d2 + 6_5536 d1 + d0 */
 311        q   = 656 * d3 + 7296 * d2 + 5536 * d1 + ((uint32_t)n & 0xffff);
 312        q = put_dec_helper4(buf, q);
 313
 314        q += 7671 * d3 + 9496 * d2 + 6 * d1;
 315        q = put_dec_helper4(buf+4, q);
 316
 317        q += 4749 * d3 + 42 * d2;
 318        q = put_dec_helper4(buf+8, q);
 319
 320        q += 281 * d3;
 321        buf += 12;
 322        if (q)
 323                buf = put_dec_trunc8(buf, q);
 324        else while (buf[-1] == '0')
 325                --buf;
 326
 327        return buf;
 328}
 329
 330#endif
 331
 332/*
 333 * Convert passed number to decimal string.
 334 * Returns the length of string.  On buffer overflow, returns 0.
 335 *
 336 * If speed is not important, use snprintf(). It's easy to read the code.
 337 */
 338int num_to_str(char *buf, int size, unsigned long long num)
 339{
 340        /* put_dec requires 2-byte alignment of the buffer. */
 341        char tmp[sizeof(num) * 3] __aligned(2);
 342        int idx, len;
 343
 344        /* put_dec() may work incorrectly for num = 0 (generate "", not "0") */
 345        if (num <= 9) {
 346                tmp[0] = '0' + num;
 347                len = 1;
 348        } else {
 349                len = put_dec(tmp, num) - tmp;
 350        }
 351
 352        if (len > size)
 353                return 0;
 354        for (idx = 0; idx < len; ++idx)
 355                buf[idx] = tmp[len - idx - 1];
 356        return len;
 357}
 358
 359#define SIGN    1               /* unsigned/signed, must be 1 */
 360#define LEFT    2               /* left justified */
 361#define PLUS    4               /* show plus */
 362#define SPACE   8               /* space if plus */
 363#define ZEROPAD 16              /* pad with zero, must be 16 == '0' - ' ' */
 364#define SMALL   32              /* use lowercase in hex (must be 32 == 0x20) */
 365#define SPECIAL 64              /* prefix hex with "0x", octal with "0" */
 366
 367enum format_type {
 368        FORMAT_TYPE_NONE, /* Just a string part */
 369        FORMAT_TYPE_WIDTH,
 370        FORMAT_TYPE_PRECISION,
 371        FORMAT_TYPE_CHAR,
 372        FORMAT_TYPE_STR,
 373        FORMAT_TYPE_PTR,
 374        FORMAT_TYPE_PERCENT_CHAR,
 375        FORMAT_TYPE_INVALID,
 376        FORMAT_TYPE_LONG_LONG,
 377        FORMAT_TYPE_ULONG,
 378        FORMAT_TYPE_LONG,
 379        FORMAT_TYPE_UBYTE,
 380        FORMAT_TYPE_BYTE,
 381        FORMAT_TYPE_USHORT,
 382        FORMAT_TYPE_SHORT,
 383        FORMAT_TYPE_UINT,
 384        FORMAT_TYPE_INT,
 385        FORMAT_TYPE_SIZE_T,
 386        FORMAT_TYPE_PTRDIFF
 387};
 388
 389struct printf_spec {
 390        unsigned int    type:8;         /* format_type enum */
 391        signed int      field_width:24; /* width of output field */
 392        unsigned int    flags:8;        /* flags to number() */
 393        unsigned int    base:8;         /* number base, 8, 10 or 16 only */
 394        signed int      precision:16;   /* # of digits/chars */
 395} __packed;
 396#define FIELD_WIDTH_MAX ((1 << 23) - 1)
 397#define PRECISION_MAX ((1 << 15) - 1)
 398
 399static noinline_for_stack
 400char *number(char *buf, char *end, unsigned long long num,
 401             struct printf_spec spec)
 402{
 403        /* put_dec requires 2-byte alignment of the buffer. */
 404        char tmp[3 * sizeof(num)] __aligned(2);
 405        char sign;
 406        char locase;
 407        int need_pfx = ((spec.flags & SPECIAL) && spec.base != 10);
 408        int i;
 409        bool is_zero = num == 0LL;
 410        int field_width = spec.field_width;
 411        int precision = spec.precision;
 412
 413        BUILD_BUG_ON(sizeof(struct printf_spec) != 8);
 414
 415        /* locase = 0 or 0x20. ORing digits or letters with 'locase'
 416         * produces same digits or (maybe lowercased) letters */
 417        locase = (spec.flags & SMALL);
 418        if (spec.flags & LEFT)
 419                spec.flags &= ~ZEROPAD;
 420        sign = 0;
 421        if (spec.flags & SIGN) {
 422                if ((signed long long)num < 0) {
 423                        sign = '-';
 424                        num = -(signed long long)num;
 425                        field_width--;
 426                } else if (spec.flags & PLUS) {
 427                        sign = '+';
 428                        field_width--;
 429                } else if (spec.flags & SPACE) {
 430                        sign = ' ';
 431                        field_width--;
 432                }
 433        }
 434        if (need_pfx) {
 435                if (spec.base == 16)
 436                        field_width -= 2;
 437                else if (!is_zero)
 438                        field_width--;
 439        }
 440
 441        /* generate full string in tmp[], in reverse order */
 442        i = 0;
 443        if (num < spec.base)
 444                tmp[i++] = hex_asc_upper[num] | locase;
 445        else if (spec.base != 10) { /* 8 or 16 */
 446                int mask = spec.base - 1;
 447                int shift = 3;
 448
 449                if (spec.base == 16)
 450                        shift = 4;
 451                do {
 452                        tmp[i++] = (hex_asc_upper[((unsigned char)num) & mask] | locase);
 453                        num >>= shift;
 454                } while (num);
 455        } else { /* base 10 */
 456                i = put_dec(tmp, num) - tmp;
 457        }
 458
 459        /* printing 100 using %2d gives "100", not "00" */
 460        if (i > precision)
 461                precision = i;
 462        /* leading space padding */
 463        field_width -= precision;
 464        if (!(spec.flags & (ZEROPAD | LEFT))) {
 465                while (--field_width >= 0) {
 466                        if (buf < end)
 467                                *buf = ' ';
 468                        ++buf;
 469                }
 470        }
 471        /* sign */
 472        if (sign) {
 473                if (buf < end)
 474                        *buf = sign;
 475                ++buf;
 476        }
 477        /* "0x" / "0" prefix */
 478        if (need_pfx) {
 479                if (spec.base == 16 || !is_zero) {
 480                        if (buf < end)
 481                                *buf = '0';
 482                        ++buf;
 483                }
 484                if (spec.base == 16) {
 485                        if (buf < end)
 486                                *buf = ('X' | locase);
 487                        ++buf;
 488                }
 489        }
 490        /* zero or space padding */
 491        if (!(spec.flags & LEFT)) {
 492                char c = ' ' + (spec.flags & ZEROPAD);
 493                BUILD_BUG_ON(' ' + ZEROPAD != '0');
 494                while (--field_width >= 0) {
 495                        if (buf < end)
 496                                *buf = c;
 497                        ++buf;
 498                }
 499        }
 500        /* hmm even more zero padding? */
 501        while (i <= --precision) {
 502                if (buf < end)
 503                        *buf = '0';
 504                ++buf;
 505        }
 506        /* actual digits of result */
 507        while (--i >= 0) {
 508                if (buf < end)
 509                        *buf = tmp[i];
 510                ++buf;
 511        }
 512        /* trailing space padding */
 513        while (--field_width >= 0) {
 514                if (buf < end)
 515                        *buf = ' ';
 516                ++buf;
 517        }
 518
 519        return buf;
 520}
 521
 522static noinline_for_stack
 523char *special_hex_number(char *buf, char *end, unsigned long long num, int size)
 524{
 525        struct printf_spec spec;
 526
 527        spec.type = FORMAT_TYPE_PTR;
 528        spec.field_width = 2 + 2 * size;        /* 0x + hex */
 529        spec.flags = SPECIAL | SMALL | ZEROPAD;
 530        spec.base = 16;
 531        spec.precision = -1;
 532
 533        return number(buf, end, num, spec);
 534}
 535
 536static void move_right(char *buf, char *end, unsigned len, unsigned spaces)
 537{
 538        size_t size;
 539        if (buf >= end) /* nowhere to put anything */
 540                return;
 541        size = end - buf;
 542        if (size <= spaces) {
 543                memset(buf, ' ', size);
 544                return;
 545        }
 546        if (len) {
 547                if (len > size - spaces)
 548                        len = size - spaces;
 549                memmove(buf + spaces, buf, len);
 550        }
 551        memset(buf, ' ', spaces);
 552}
 553
 554/*
 555 * Handle field width padding for a string.
 556 * @buf: current buffer position
 557 * @n: length of string
 558 * @end: end of output buffer
 559 * @spec: for field width and flags
 560 * Returns: new buffer position after padding.
 561 */
 562static noinline_for_stack
 563char *widen_string(char *buf, int n, char *end, struct printf_spec spec)
 564{
 565        unsigned spaces;
 566
 567        if (likely(n >= spec.field_width))
 568                return buf;
 569        /* we want to pad the sucker */
 570        spaces = spec.field_width - n;
 571        if (!(spec.flags & LEFT)) {
 572                move_right(buf - n, end, n, spaces);
 573                return buf + spaces;
 574        }
 575        while (spaces--) {
 576                if (buf < end)
 577                        *buf = ' ';
 578                ++buf;
 579        }
 580        return buf;
 581}
 582
 583static noinline_for_stack
 584char *string(char *buf, char *end, const char *s, struct printf_spec spec)
 585{
 586        int len = 0;
 587        size_t lim = spec.precision;
 588
 589        if ((unsigned long)s < PAGE_SIZE)
 590                s = "(null)";
 591
 592        while (lim--) {
 593                char c = *s++;
 594                if (!c)
 595                        break;
 596                if (buf < end)
 597                        *buf = c;
 598                ++buf;
 599                ++len;
 600        }
 601        return widen_string(buf, len, end, spec);
 602}
 603
 604static noinline_for_stack
 605char *dentry_name(char *buf, char *end, const struct dentry *d, struct printf_spec spec,
 606                  const char *fmt)
 607{
 608        const char *array[4], *s;
 609        const struct dentry *p;
 610        int depth;
 611        int i, n;
 612
 613        switch (fmt[1]) {
 614                case '2': case '3': case '4':
 615                        depth = fmt[1] - '0';
 616                        break;
 617                default:
 618                        depth = 1;
 619        }
 620
 621        rcu_read_lock();
 622        for (i = 0; i < depth; i++, d = p) {
 623                p = ACCESS_ONCE(d->d_parent);
 624                array[i] = ACCESS_ONCE(d->d_name.name);
 625                if (p == d) {
 626                        if (i)
 627                                array[i] = "";
 628                        i++;
 629                        break;
 630                }
 631        }
 632        s = array[--i];
 633        for (n = 0; n != spec.precision; n++, buf++) {
 634                char c = *s++;
 635                if (!c) {
 636                        if (!i)
 637                                break;
 638                        c = '/';
 639                        s = array[--i];
 640                }
 641                if (buf < end)
 642                        *buf = c;
 643        }
 644        rcu_read_unlock();
 645        return widen_string(buf, n, end, spec);
 646}
 647
 648#ifdef CONFIG_BLOCK
 649static noinline_for_stack
 650char *bdev_name(char *buf, char *end, struct block_device *bdev,
 651                struct printf_spec spec, const char *fmt)
 652{
 653        struct gendisk *hd = bdev->bd_disk;
 654        
 655        buf = string(buf, end, hd->disk_name, spec);
 656        if (bdev->bd_part->partno) {
 657                if (isdigit(hd->disk_name[strlen(hd->disk_name)-1])) {
 658                        if (buf < end)
 659                                *buf = 'p';
 660                        buf++;
 661                }
 662                buf = number(buf, end, bdev->bd_part->partno, spec);
 663        }
 664        return buf;
 665}
 666#endif
 667
 668static noinline_for_stack
 669char *symbol_string(char *buf, char *end, void *ptr,
 670                    struct printf_spec spec, const char *fmt)
 671{
 672        unsigned long value;
 673#ifdef CONFIG_KALLSYMS
 674        char sym[KSYM_SYMBOL_LEN];
 675#endif
 676
 677        if (fmt[1] == 'R')
 678                ptr = __builtin_extract_return_addr(ptr);
 679        value = (unsigned long)ptr;
 680
 681#ifdef CONFIG_KALLSYMS
 682        if (*fmt == 'B')
 683                sprint_backtrace(sym, value);
 684        else if (*fmt != 'f' && *fmt != 's')
 685                sprint_symbol(sym, value);
 686        else
 687                sprint_symbol_no_offset(sym, value);
 688
 689        return string(buf, end, sym, spec);
 690#else
 691        return special_hex_number(buf, end, value, sizeof(void *));
 692#endif
 693}
 694
 695static noinline_for_stack
 696char *resource_string(char *buf, char *end, struct resource *res,
 697                      struct printf_spec spec, const char *fmt)
 698{
 699#ifndef IO_RSRC_PRINTK_SIZE
 700#define IO_RSRC_PRINTK_SIZE     6
 701#endif
 702
 703#ifndef MEM_RSRC_PRINTK_SIZE
 704#define MEM_RSRC_PRINTK_SIZE    10
 705#endif
 706        static const struct printf_spec io_spec = {
 707                .base = 16,
 708                .field_width = IO_RSRC_PRINTK_SIZE,
 709                .precision = -1,
 710                .flags = SPECIAL | SMALL | ZEROPAD,
 711        };
 712        static const struct printf_spec mem_spec = {
 713                .base = 16,
 714                .field_width = MEM_RSRC_PRINTK_SIZE,
 715                .precision = -1,
 716                .flags = SPECIAL | SMALL | ZEROPAD,
 717        };
 718        static const struct printf_spec bus_spec = {
 719                .base = 16,
 720                .field_width = 2,
 721                .precision = -1,
 722                .flags = SMALL | ZEROPAD,
 723        };
 724        static const struct printf_spec dec_spec = {
 725                .base = 10,
 726                .precision = -1,
 727                .flags = 0,
 728        };
 729        static const struct printf_spec str_spec = {
 730                .field_width = -1,
 731                .precision = 10,
 732                .flags = LEFT,
 733        };
 734        static const struct printf_spec flag_spec = {
 735                .base = 16,
 736                .precision = -1,
 737                .flags = SPECIAL | SMALL,
 738        };
 739
 740        /* 32-bit res (sizeof==4): 10 chars in dec, 10 in hex ("0x" + 8)
 741         * 64-bit res (sizeof==8): 20 chars in dec, 18 in hex ("0x" + 16) */
 742#define RSRC_BUF_SIZE           ((2 * sizeof(resource_size_t)) + 4)
 743#define FLAG_BUF_SIZE           (2 * sizeof(res->flags))
 744#define DECODED_BUF_SIZE        sizeof("[mem - 64bit pref window disabled]")
 745#define RAW_BUF_SIZE            sizeof("[mem - flags 0x]")
 746        char sym[max(2*RSRC_BUF_SIZE + DECODED_BUF_SIZE,
 747                     2*RSRC_BUF_SIZE + FLAG_BUF_SIZE + RAW_BUF_SIZE)];
 748
 749        char *p = sym, *pend = sym + sizeof(sym);
 750        int decode = (fmt[0] == 'R') ? 1 : 0;
 751        const struct printf_spec *specp;
 752
 753        *p++ = '[';
 754        if (res->flags & IORESOURCE_IO) {
 755                p = string(p, pend, "io  ", str_spec);
 756                specp = &io_spec;
 757        } else if (res->flags & IORESOURCE_MEM) {
 758                p = string(p, pend, "mem ", str_spec);
 759                specp = &mem_spec;
 760        } else if (res->flags & IORESOURCE_IRQ) {
 761                p = string(p, pend, "irq ", str_spec);
 762                specp = &dec_spec;
 763        } else if (res->flags & IORESOURCE_DMA) {
 764                p = string(p, pend, "dma ", str_spec);
 765                specp = &dec_spec;
 766        } else if (res->flags & IORESOURCE_BUS) {
 767                p = string(p, pend, "bus ", str_spec);
 768                specp = &bus_spec;
 769        } else {
 770                p = string(p, pend, "??? ", str_spec);
 771                specp = &mem_spec;
 772                decode = 0;
 773        }
 774        if (decode && res->flags & IORESOURCE_UNSET) {
 775                p = string(p, pend, "size ", str_spec);
 776                p = number(p, pend, resource_size(res), *specp);
 777        } else {
 778                p = number(p, pend, res->start, *specp);
 779                if (res->start != res->end) {
 780                        *p++ = '-';
 781                        p = number(p, pend, res->end, *specp);
 782                }
 783        }
 784        if (decode) {
 785                if (res->flags & IORESOURCE_MEM_64)
 786                        p = string(p, pend, " 64bit", str_spec);
 787                if (res->flags & IORESOURCE_PREFETCH)
 788                        p = string(p, pend, " pref", str_spec);
 789                if (res->flags & IORESOURCE_WINDOW)
 790                        p = string(p, pend, " window", str_spec);
 791                if (res->flags & IORESOURCE_DISABLED)
 792                        p = string(p, pend, " disabled", str_spec);
 793        } else {
 794                p = string(p, pend, " flags ", str_spec);
 795                p = number(p, pend, res->flags, flag_spec);
 796        }
 797        *p++ = ']';
 798        *p = '\0';
 799
 800        return string(buf, end, sym, spec);
 801}
 802
 803static noinline_for_stack
 804char *hex_string(char *buf, char *end, u8 *addr, struct printf_spec spec,
 805                 const char *fmt)
 806{
 807        int i, len = 1;         /* if we pass '%ph[CDN]', field width remains
 808                                   negative value, fallback to the default */
 809        char separator;
 810
 811        if (spec.field_width == 0)
 812                /* nothing to print */
 813                return buf;
 814
 815        if (ZERO_OR_NULL_PTR(addr))
 816                /* NULL pointer */
 817                return string(buf, end, NULL, spec);
 818
 819        switch (fmt[1]) {
 820        case 'C':
 821                separator = ':';
 822                break;
 823        case 'D':
 824                separator = '-';
 825                break;
 826        case 'N':
 827                separator = 0;
 828                break;
 829        default:
 830                separator = ' ';
 831                break;
 832        }
 833
 834        if (spec.field_width > 0)
 835                len = min_t(int, spec.field_width, 64);
 836
 837        for (i = 0; i < len; ++i) {
 838                if (buf < end)
 839                        *buf = hex_asc_hi(addr[i]);
 840                ++buf;
 841                if (buf < end)
 842                        *buf = hex_asc_lo(addr[i]);
 843                ++buf;
 844
 845                if (separator && i != len - 1) {
 846                        if (buf < end)
 847                                *buf = separator;
 848                        ++buf;
 849                }
 850        }
 851
 852        return buf;
 853}
 854
 855static noinline_for_stack
 856char *bitmap_string(char *buf, char *end, unsigned long *bitmap,
 857                    struct printf_spec spec, const char *fmt)
 858{
 859        const int CHUNKSZ = 32;
 860        int nr_bits = max_t(int, spec.field_width, 0);
 861        int i, chunksz;
 862        bool first = true;
 863
 864        /* reused to print numbers */
 865        spec = (struct printf_spec){ .flags = SMALL | ZEROPAD, .base = 16 };
 866
 867        chunksz = nr_bits & (CHUNKSZ - 1);
 868        if (chunksz == 0)
 869                chunksz = CHUNKSZ;
 870
 871        i = ALIGN(nr_bits, CHUNKSZ) - CHUNKSZ;
 872        for (; i >= 0; i -= CHUNKSZ) {
 873                u32 chunkmask, val;
 874                int word, bit;
 875
 876                chunkmask = ((1ULL << chunksz) - 1);
 877                word = i / BITS_PER_LONG;
 878                bit = i % BITS_PER_LONG;
 879                val = (bitmap[word] >> bit) & chunkmask;
 880
 881                if (!first) {
 882                        if (buf < end)
 883                                *buf = ',';
 884                        buf++;
 885                }
 886                first = false;
 887
 888                spec.field_width = DIV_ROUND_UP(chunksz, 4);
 889                buf = number(buf, end, val, spec);
 890
 891                chunksz = CHUNKSZ;
 892        }
 893        return buf;
 894}
 895
 896static noinline_for_stack
 897char *bitmap_list_string(char *buf, char *end, unsigned long *bitmap,
 898                         struct printf_spec spec, const char *fmt)
 899{
 900        int nr_bits = max_t(int, spec.field_width, 0);
 901        /* current bit is 'cur', most recently seen range is [rbot, rtop] */
 902        int cur, rbot, rtop;
 903        bool first = true;
 904
 905        /* reused to print numbers */
 906        spec = (struct printf_spec){ .base = 10 };
 907
 908        rbot = cur = find_first_bit(bitmap, nr_bits);
 909        while (cur < nr_bits) {
 910                rtop = cur;
 911                cur = find_next_bit(bitmap, nr_bits, cur + 1);
 912                if (cur < nr_bits && cur <= rtop + 1)
 913                        continue;
 914
 915                if (!first) {
 916                        if (buf < end)
 917                                *buf = ',';
 918                        buf++;
 919                }
 920                first = false;
 921
 922                buf = number(buf, end, rbot, spec);
 923                if (rbot < rtop) {
 924                        if (buf < end)
 925                                *buf = '-';
 926                        buf++;
 927
 928                        buf = number(buf, end, rtop, spec);
 929                }
 930
 931                rbot = cur;
 932        }
 933        return buf;
 934}
 935
 936static noinline_for_stack
 937char *mac_address_string(char *buf, char *end, u8 *addr,
 938                         struct printf_spec spec, const char *fmt)
 939{
 940        char mac_addr[sizeof("xx:xx:xx:xx:xx:xx")];
 941        char *p = mac_addr;
 942        int i;
 943        char separator;
 944        bool reversed = false;
 945
 946        switch (fmt[1]) {
 947        case 'F':
 948                separator = '-';
 949                break;
 950
 951        case 'R':
 952                reversed = true;
 953                /* fall through */
 954
 955        default:
 956                separator = ':';
 957                break;
 958        }
 959
 960        for (i = 0; i < 6; i++) {
 961                if (reversed)
 962                        p = hex_byte_pack(p, addr[5 - i]);
 963                else
 964                        p = hex_byte_pack(p, addr[i]);
 965
 966                if (fmt[0] == 'M' && i != 5)
 967                        *p++ = separator;
 968        }
 969        *p = '\0';
 970
 971        return string(buf, end, mac_addr, spec);
 972}
 973
 974static noinline_for_stack
 975char *ip4_string(char *p, const u8 *addr, const char *fmt)
 976{
 977        int i;
 978        bool leading_zeros = (fmt[0] == 'i');
 979        int index;
 980        int step;
 981
 982        switch (fmt[2]) {
 983        case 'h':
 984#ifdef __BIG_ENDIAN
 985                index = 0;
 986                step = 1;
 987#else
 988                index = 3;
 989                step = -1;
 990#endif
 991                break;
 992        case 'l':
 993                index = 3;
 994                step = -1;
 995                break;
 996        case 'n':
 997        case 'b':
 998        default:
 999                index = 0;
1000                step = 1;
1001                break;
1002        }
1003        for (i = 0; i < 4; i++) {
1004                char temp[4] __aligned(2);      /* hold each IP quad in reverse order */
1005                int digits = put_dec_trunc8(temp, addr[index]) - temp;
1006                if (leading_zeros) {
1007                        if (digits < 3)
1008                                *p++ = '0';
1009                        if (digits < 2)
1010                                *p++ = '0';
1011                }
1012                /* reverse the digits in the quad */
1013                while (digits--)
1014                        *p++ = temp[digits];
1015                if (i < 3)
1016                        *p++ = '.';
1017                index += step;
1018        }
1019        *p = '\0';
1020
1021        return p;
1022}
1023
1024static noinline_for_stack
1025char *ip6_compressed_string(char *p, const char *addr)
1026{
1027        int i, j, range;
1028        unsigned char zerolength[8];
1029        int longest = 1;
1030        int colonpos = -1;
1031        u16 word;
1032        u8 hi, lo;
1033        bool needcolon = false;
1034        bool useIPv4;
1035        struct in6_addr in6;
1036
1037        memcpy(&in6, addr, sizeof(struct in6_addr));
1038
1039        useIPv4 = ipv6_addr_v4mapped(&in6) || ipv6_addr_is_isatap(&in6);
1040
1041        memset(zerolength, 0, sizeof(zerolength));
1042
1043        if (useIPv4)
1044                range = 6;
1045        else
1046                range = 8;
1047
1048        /* find position of longest 0 run */
1049        for (i = 0; i < range; i++) {
1050                for (j = i; j < range; j++) {
1051                        if (in6.s6_addr16[j] != 0)
1052                                break;
1053                        zerolength[i]++;
1054                }
1055        }
1056        for (i = 0; i < range; i++) {
1057                if (zerolength[i] > longest) {
1058                        longest = zerolength[i];
1059                        colonpos = i;
1060                }
1061        }
1062        if (longest == 1)               /* don't compress a single 0 */
1063                colonpos = -1;
1064
1065        /* emit address */
1066        for (i = 0; i < range; i++) {
1067                if (i == colonpos) {
1068                        if (needcolon || i == 0)
1069                                *p++ = ':';
1070                        *p++ = ':';
1071                        needcolon = false;
1072                        i += longest - 1;
1073                        continue;
1074                }
1075                if (needcolon) {
1076                        *p++ = ':';
1077                        needcolon = false;
1078                }
1079                /* hex u16 without leading 0s */
1080                word = ntohs(in6.s6_addr16[i]);
1081                hi = word >> 8;
1082                lo = word & 0xff;
1083                if (hi) {
1084                        if (hi > 0x0f)
1085                                p = hex_byte_pack(p, hi);
1086                        else
1087                                *p++ = hex_asc_lo(hi);
1088                        p = hex_byte_pack(p, lo);
1089                }
1090                else if (lo > 0x0f)
1091                        p = hex_byte_pack(p, lo);
1092                else
1093                        *p++ = hex_asc_lo(lo);
1094                needcolon = true;
1095        }
1096
1097        if (useIPv4) {
1098                if (needcolon)
1099                        *p++ = ':';
1100                p = ip4_string(p, &in6.s6_addr[12], "I4");
1101        }
1102        *p = '\0';
1103
1104        return p;
1105}
1106
1107static noinline_for_stack
1108char *ip6_string(char *p, const char *addr, const char *fmt)
1109{
1110        int i;
1111
1112        for (i = 0; i < 8; i++) {
1113                p = hex_byte_pack(p, *addr++);
1114                p = hex_byte_pack(p, *addr++);
1115                if (fmt[0] == 'I' && i != 7)
1116                        *p++ = ':';
1117        }
1118        *p = '\0';
1119
1120        return p;
1121}
1122
1123static noinline_for_stack
1124char *ip6_addr_string(char *buf, char *end, const u8 *addr,
1125                      struct printf_spec spec, const char *fmt)
1126{
1127        char ip6_addr[sizeof("xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255")];
1128
1129        if (fmt[0] == 'I' && fmt[2] == 'c')
1130                ip6_compressed_string(ip6_addr, addr);
1131        else
1132                ip6_string(ip6_addr, addr, fmt);
1133
1134        return string(buf, end, ip6_addr, spec);
1135}
1136
1137static noinline_for_stack
1138char *ip4_addr_string(char *buf, char *end, const u8 *addr,
1139                      struct printf_spec spec, const char *fmt)
1140{
1141        char ip4_addr[sizeof("255.255.255.255")];
1142
1143        ip4_string(ip4_addr, addr, fmt);
1144
1145        return string(buf, end, ip4_addr, spec);
1146}
1147
1148static noinline_for_stack
1149char *ip6_addr_string_sa(char *buf, char *end, const struct sockaddr_in6 *sa,
1150                         struct printf_spec spec, const char *fmt)
1151{
1152        bool have_p = false, have_s = false, have_f = false, have_c = false;
1153        char ip6_addr[sizeof("[xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255]") +
1154                      sizeof(":12345") + sizeof("/123456789") +
1155                      sizeof("%1234567890")];
1156        char *p = ip6_addr, *pend = ip6_addr + sizeof(ip6_addr);
1157        const u8 *addr = (const u8 *) &sa->sin6_addr;
1158        char fmt6[2] = { fmt[0], '6' };
1159        u8 off = 0;
1160
1161        fmt++;
1162        while (isalpha(*++fmt)) {
1163                switch (*fmt) {
1164                case 'p':
1165                        have_p = true;
1166                        break;
1167                case 'f':
1168                        have_f = true;
1169                        break;
1170                case 's':
1171                        have_s = true;
1172                        break;
1173                case 'c':
1174                        have_c = true;
1175                        break;
1176                }
1177        }
1178
1179        if (have_p || have_s || have_f) {
1180                *p = '[';
1181                off = 1;
1182        }
1183
1184        if (fmt6[0] == 'I' && have_c)
1185                p = ip6_compressed_string(ip6_addr + off, addr);
1186        else
1187                p = ip6_string(ip6_addr + off, addr, fmt6);
1188
1189        if (have_p || have_s || have_f)
1190                *p++ = ']';
1191
1192        if (have_p) {
1193                *p++ = ':';
1194                p = number(p, pend, ntohs(sa->sin6_port), spec);
1195        }
1196        if (have_f) {
1197                *p++ = '/';
1198                p = number(p, pend, ntohl(sa->sin6_flowinfo &
1199                                          IPV6_FLOWINFO_MASK), spec);
1200        }
1201        if (have_s) {
1202                *p++ = '%';
1203                p = number(p, pend, sa->sin6_scope_id, spec);
1204        }
1205        *p = '\0';
1206
1207        return string(buf, end, ip6_addr, spec);
1208}
1209
1210static noinline_for_stack
1211char *ip4_addr_string_sa(char *buf, char *end, const struct sockaddr_in *sa,
1212                         struct printf_spec spec, const char *fmt)
1213{
1214        bool have_p = false;
1215        char *p, ip4_addr[sizeof("255.255.255.255") + sizeof(":12345")];
1216        char *pend = ip4_addr + sizeof(ip4_addr);
1217        const u8 *addr = (const u8 *) &sa->sin_addr.s_addr;
1218        char fmt4[3] = { fmt[0], '4', 0 };
1219
1220        fmt++;
1221        while (isalpha(*++fmt)) {
1222                switch (*fmt) {
1223                case 'p':
1224                        have_p = true;
1225                        break;
1226                case 'h':
1227                case 'l':
1228                case 'n':
1229                case 'b':
1230                        fmt4[2] = *fmt;
1231                        break;
1232                }
1233        }
1234
1235        p = ip4_string(ip4_addr, addr, fmt4);
1236        if (have_p) {
1237                *p++ = ':';
1238                p = number(p, pend, ntohs(sa->sin_port), spec);
1239        }
1240        *p = '\0';
1241
1242        return string(buf, end, ip4_addr, spec);
1243}
1244
1245static noinline_for_stack
1246char *escaped_string(char *buf, char *end, u8 *addr, struct printf_spec spec,
1247                     const char *fmt)
1248{
1249        bool found = true;
1250        int count = 1;
1251        unsigned int flags = 0;
1252        int len;
1253
1254        if (spec.field_width == 0)
1255                return buf;                             /* nothing to print */
1256
1257        if (ZERO_OR_NULL_PTR(addr))
1258                return string(buf, end, NULL, spec);    /* NULL pointer */
1259
1260
1261        do {
1262                switch (fmt[count++]) {
1263                case 'a':
1264                        flags |= ESCAPE_ANY;
1265                        break;
1266                case 'c':
1267                        flags |= ESCAPE_SPECIAL;
1268                        break;
1269                case 'h':
1270                        flags |= ESCAPE_HEX;
1271                        break;
1272                case 'n':
1273                        flags |= ESCAPE_NULL;
1274                        break;
1275                case 'o':
1276                        flags |= ESCAPE_OCTAL;
1277                        break;
1278                case 'p':
1279                        flags |= ESCAPE_NP;
1280                        break;
1281                case 's':
1282                        flags |= ESCAPE_SPACE;
1283                        break;
1284                default:
1285                        found = false;
1286                        break;
1287                }
1288        } while (found);
1289
1290        if (!flags)
1291                flags = ESCAPE_ANY_NP;
1292
1293        len = spec.field_width < 0 ? 1 : spec.field_width;
1294
1295        /*
1296         * string_escape_mem() writes as many characters as it can to
1297         * the given buffer, and returns the total size of the output
1298         * had the buffer been big enough.
1299         */
1300        buf += string_escape_mem(addr, len, buf, buf < end ? end - buf : 0, flags, NULL);
1301
1302        return buf;
1303}
1304
1305static noinline_for_stack
1306char *uuid_string(char *buf, char *end, const u8 *addr,
1307                  struct printf_spec spec, const char *fmt)
1308{
1309        char uuid[UUID_STRING_LEN + 1];
1310        char *p = uuid;
1311        int i;
1312        const u8 *index = uuid_index;
1313        bool uc = false;
1314
1315        switch (*(++fmt)) {
1316        case 'L':
1317                uc = true;              /* fall-through */
1318        case 'l':
1319                index = guid_index;
1320                break;
1321        case 'B':
1322                uc = true;
1323                break;
1324        }
1325
1326        for (i = 0; i < 16; i++) {
1327                if (uc)
1328                        p = hex_byte_pack_upper(p, addr[index[i]]);
1329                else
1330                        p = hex_byte_pack(p, addr[index[i]]);
1331                switch (i) {
1332                case 3:
1333                case 5:
1334                case 7:
1335                case 9:
1336                        *p++ = '-';
1337                        break;
1338                }
1339        }
1340
1341        *p = 0;
1342
1343        return string(buf, end, uuid, spec);
1344}
1345
1346static noinline_for_stack
1347char *netdev_bits(char *buf, char *end, const void *addr, const char *fmt)
1348{
1349        unsigned long long num;
1350        int size;
1351
1352        switch (fmt[1]) {
1353        case 'F':
1354                num = *(const netdev_features_t *)addr;
1355                size = sizeof(netdev_features_t);
1356                break;
1357        default:
1358                num = (unsigned long)addr;
1359                size = sizeof(unsigned long);
1360                break;
1361        }
1362
1363        return special_hex_number(buf, end, num, size);
1364}
1365
1366static noinline_for_stack
1367char *address_val(char *buf, char *end, const void *addr, const char *fmt)
1368{
1369        unsigned long long num;
1370        int size;
1371
1372        switch (fmt[1]) {
1373        case 'd':
1374                num = *(const dma_addr_t *)addr;
1375                size = sizeof(dma_addr_t);
1376                break;
1377        case 'p':
1378        default:
1379                num = *(const phys_addr_t *)addr;
1380                size = sizeof(phys_addr_t);
1381                break;
1382        }
1383
1384        return special_hex_number(buf, end, num, size);
1385}
1386
1387static noinline_for_stack
1388char *clock(char *buf, char *end, struct clk *clk, struct printf_spec spec,
1389            const char *fmt)
1390{
1391        if (!IS_ENABLED(CONFIG_HAVE_CLK) || !clk)
1392                return string(buf, end, NULL, spec);
1393
1394        switch (fmt[1]) {
1395        case 'r':
1396                return number(buf, end, clk_get_rate(clk), spec);
1397
1398        case 'n':
1399        default:
1400#ifdef CONFIG_COMMON_CLK
1401                return string(buf, end, __clk_get_name(clk), spec);
1402#else
1403                return special_hex_number(buf, end, (unsigned long)clk, sizeof(unsigned long));
1404#endif
1405        }
1406}
1407
1408static
1409char *format_flags(char *buf, char *end, unsigned long flags,
1410                                        const struct trace_print_flags *names)
1411{
1412        unsigned long mask;
1413        const struct printf_spec strspec = {
1414                .field_width = -1,
1415                .precision = -1,
1416        };
1417        const struct printf_spec numspec = {
1418                .flags = SPECIAL|SMALL,
1419                .field_width = -1,
1420                .precision = -1,
1421                .base = 16,
1422        };
1423
1424        for ( ; flags && names->name; names++) {
1425                mask = names->mask;
1426                if ((flags & mask) != mask)
1427                        continue;
1428
1429                buf = string(buf, end, names->name, strspec);
1430
1431                flags &= ~mask;
1432                if (flags) {
1433                        if (buf < end)
1434                                *buf = '|';
1435                        buf++;
1436                }
1437        }
1438
1439        if (flags)
1440                buf = number(buf, end, flags, numspec);
1441
1442        return buf;
1443}
1444
1445static noinline_for_stack
1446char *flags_string(char *buf, char *end, void *flags_ptr, const char *fmt)
1447{
1448        unsigned long flags;
1449        const struct trace_print_flags *names;
1450
1451        switch (fmt[1]) {
1452        case 'p':
1453                flags = *(unsigned long *)flags_ptr;
1454                /* Remove zone id */
1455                flags &= (1UL << NR_PAGEFLAGS) - 1;
1456                names = pageflag_names;
1457                break;
1458        case 'v':
1459                flags = *(unsigned long *)flags_ptr;
1460                names = vmaflag_names;
1461                break;
1462        case 'g':
1463                flags = *(gfp_t *)flags_ptr;
1464                names = gfpflag_names;
1465                break;
1466        default:
1467                WARN_ONCE(1, "Unsupported flags modifier: %c\n", fmt[1]);
1468                return buf;
1469        }
1470
1471        return format_flags(buf, end, flags, names);
1472}
1473
1474static const char *device_node_name_for_depth(const struct device_node *np, int depth)
1475{
1476        for ( ; np && depth; depth--)
1477                np = np->parent;
1478
1479        return kbasename(np->full_name);
1480}
1481
1482static noinline_for_stack
1483char *device_node_gen_full_name(const struct device_node *np, char *buf, char *end)
1484{
1485        int depth;
1486        const struct device_node *parent = np->parent;
1487        static const struct printf_spec strspec = {
1488                .field_width = -1,
1489                .precision = -1,
1490        };
1491
1492        /* special case for root node */
1493        if (!parent)
1494                return string(buf, end, "/", strspec);
1495
1496        for (depth = 0; parent->parent; depth++)
1497                parent = parent->parent;
1498
1499        for ( ; depth >= 0; depth--) {
1500                buf = string(buf, end, "/", strspec);
1501                buf = string(buf, end, device_node_name_for_depth(np, depth),
1502                             strspec);
1503        }
1504        return buf;
1505}
1506
1507static noinline_for_stack
1508char *device_node_string(char *buf, char *end, struct device_node *dn,
1509                         struct printf_spec spec, const char *fmt)
1510{
1511        char tbuf[sizeof("xxxx") + 1];
1512        const char *p;
1513        int ret;
1514        char *buf_start = buf;
1515        struct property *prop;
1516        bool has_mult, pass;
1517        static const struct printf_spec num_spec = {
1518                .flags = SMALL,
1519                .field_width = -1,
1520                .precision = -1,
1521                .base = 10,
1522        };
1523
1524        struct printf_spec str_spec = spec;
1525        str_spec.field_width = -1;
1526
1527        if (!IS_ENABLED(CONFIG_OF))
1528                return string(buf, end, "(!OF)", spec);
1529
1530        if ((unsigned long)dn < PAGE_SIZE)
1531                return string(buf, end, "(null)", spec);
1532
1533        /* simple case without anything any more format specifiers */
1534        fmt++;
1535        if (fmt[0] == '\0' || strcspn(fmt,"fnpPFcC") > 0)
1536                fmt = "f";
1537
1538        for (pass = false; strspn(fmt,"fnpPFcC"); fmt++, pass = true) {
1539                if (pass) {
1540                        if (buf < end)
1541                                *buf = ':';
1542                        buf++;
1543                }
1544
1545                switch (*fmt) {
1546                case 'f':       /* full_name */
1547                        buf = device_node_gen_full_name(dn, buf, end);
1548                        break;
1549                case 'n':       /* name */
1550                        buf = string(buf, end, dn->name, str_spec);
1551                        break;
1552                case 'p':       /* phandle */
1553                        buf = number(buf, end, (unsigned int)dn->phandle, num_spec);
1554                        break;
1555                case 'P':       /* path-spec */
1556                        p = kbasename(of_node_full_name(dn));
1557                        if (!p[1])
1558                                p = "/";
1559                        buf = string(buf, end, p, str_spec);
1560                        break;
1561                case 'F':       /* flags */
1562                        tbuf[0] = of_node_check_flag(dn, OF_DYNAMIC) ? 'D' : '-';
1563                        tbuf[1] = of_node_check_flag(dn, OF_DETACHED) ? 'd' : '-';
1564                        tbuf[2] = of_node_check_flag(dn, OF_POPULATED) ? 'P' : '-';
1565                        tbuf[3] = of_node_check_flag(dn, OF_POPULATED_BUS) ? 'B' : '-';
1566                        tbuf[4] = 0;
1567                        buf = string(buf, end, tbuf, str_spec);
1568                        break;
1569                case 'c':       /* major compatible string */
1570                        ret = of_property_read_string(dn, "compatible", &p);
1571                        if (!ret)
1572                                buf = string(buf, end, p, str_spec);
1573                        break;
1574                case 'C':       /* full compatible string */
1575                        has_mult = false;
1576                        of_property_for_each_string(dn, "compatible", prop, p) {
1577                                if (has_mult)
1578                                        buf = string(buf, end, ",", str_spec);
1579                                buf = string(buf, end, "\"", str_spec);
1580                                buf = string(buf, end, p, str_spec);
1581                                buf = string(buf, end, "\"", str_spec);
1582
1583                                has_mult = true;
1584                        }
1585                        break;
1586                default:
1587                        break;
1588                }
1589        }
1590
1591        return widen_string(buf, buf - buf_start, end, spec);
1592}
1593
1594int kptr_restrict __read_mostly;
1595
1596/*
1597 * Show a '%p' thing.  A kernel extension is that the '%p' is followed
1598 * by an extra set of alphanumeric characters that are extended format
1599 * specifiers.
1600 *
1601 * Please update scripts/checkpatch.pl when adding/removing conversion
1602 * characters.  (Search for "check for vsprintf extension").
1603 *
1604 * Right now we handle:
1605 *
1606 * - 'F' For symbolic function descriptor pointers with offset
1607 * - 'f' For simple symbolic function names without offset
1608 * - 'S' For symbolic direct pointers with offset
1609 * - 's' For symbolic direct pointers without offset
1610 * - '[FfSs]R' as above with __builtin_extract_return_addr() translation
1611 * - 'B' For backtraced symbolic direct pointers with offset
1612 * - 'R' For decoded struct resource, e.g., [mem 0x0-0x1f 64bit pref]
1613 * - 'r' For raw struct resource, e.g., [mem 0x0-0x1f flags 0x201]
1614 * - 'b[l]' For a bitmap, the number of bits is determined by the field
1615 *       width which must be explicitly specified either as part of the
1616 *       format string '%32b[l]' or through '%*b[l]', [l] selects
1617 *       range-list format instead of hex format
1618 * - 'M' For a 6-byte MAC address, it prints the address in the
1619 *       usual colon-separated hex notation
1620 * - 'm' For a 6-byte MAC address, it prints the hex address without colons
1621 * - 'MF' For a 6-byte MAC FDDI address, it prints the address
1622 *       with a dash-separated hex notation
1623 * - '[mM]R' For a 6-byte MAC address, Reverse order (Bluetooth)
1624 * - 'I' [46] for IPv4/IPv6 addresses printed in the usual way
1625 *       IPv4 uses dot-separated decimal without leading 0's (1.2.3.4)
1626 *       IPv6 uses colon separated network-order 16 bit hex with leading 0's
1627 *       [S][pfs]
1628 *       Generic IPv4/IPv6 address (struct sockaddr *) that falls back to
1629 *       [4] or [6] and is able to print port [p], flowinfo [f], scope [s]
1630 * - 'i' [46] for 'raw' IPv4/IPv6 addresses
1631 *       IPv6 omits the colons (01020304...0f)
1632 *       IPv4 uses dot-separated decimal with leading 0's (010.123.045.006)
1633 *       [S][pfs]
1634 *       Generic IPv4/IPv6 address (struct sockaddr *) that falls back to
1635 *       [4] or [6] and is able to print port [p], flowinfo [f], scope [s]
1636 * - '[Ii][4S][hnbl]' IPv4 addresses in host, network, big or little endian order
1637 * - 'I[6S]c' for IPv6 addresses printed as specified by
1638 *       http://tools.ietf.org/html/rfc5952
1639 * - 'E[achnops]' For an escaped buffer, where rules are defined by combination
1640 *                of the following flags (see string_escape_mem() for the
1641 *                details):
1642 *                  a - ESCAPE_ANY
1643 *                  c - ESCAPE_SPECIAL
1644 *                  h - ESCAPE_HEX
1645 *                  n - ESCAPE_NULL
1646 *                  o - ESCAPE_OCTAL
1647 *                  p - ESCAPE_NP
1648 *                  s - ESCAPE_SPACE
1649 *                By default ESCAPE_ANY_NP is used.
1650 * - 'U' For a 16 byte UUID/GUID, it prints the UUID/GUID in the form
1651 *       "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx"
1652 *       Options for %pU are:
1653 *         b big endian lower case hex (default)
1654 *         B big endian UPPER case hex
1655 *         l little endian lower case hex
1656 *         L little endian UPPER case hex
1657 *           big endian output byte order is:
1658 *             [0][1][2][3]-[4][5]-[6][7]-[8][9]-[10][11][12][13][14][15]
1659 *           little endian output byte order is:
1660 *             [3][2][1][0]-[5][4]-[7][6]-[8][9]-[10][11][12][13][14][15]
1661 * - 'V' For a struct va_format which contains a format string * and va_list *,
1662 *       call vsnprintf(->format, *->va_list).
1663 *       Implements a "recursive vsnprintf".
1664 *       Do not use this feature without some mechanism to verify the
1665 *       correctness of the format string and va_list arguments.
1666 * - 'K' For a kernel pointer that should be hidden from unprivileged users
1667 * - 'NF' For a netdev_features_t
1668 * - 'h[CDN]' For a variable-length buffer, it prints it as a hex string with
1669 *            a certain separator (' ' by default):
1670 *              C colon
1671 *              D dash
1672 *              N no separator
1673 *            The maximum supported length is 64 bytes of the input. Consider
1674 *            to use print_hex_dump() for the larger input.
1675 * - 'a[pd]' For address types [p] phys_addr_t, [d] dma_addr_t and derivatives
1676 *           (default assumed to be phys_addr_t, passed by reference)
1677 * - 'd[234]' For a dentry name (optionally 2-4 last components)
1678 * - 'D[234]' Same as 'd' but for a struct file
1679 * - 'g' For block_device name (gendisk + partition number)
1680 * - 'C' For a clock, it prints the name (Common Clock Framework) or address
1681 *       (legacy clock framework) of the clock
1682 * - 'Cn' For a clock, it prints the name (Common Clock Framework) or address
1683 *        (legacy clock framework) of the clock
1684 * - 'Cr' For a clock, it prints the current rate of the clock
1685 * - 'G' For flags to be printed as a collection of symbolic strings that would
1686 *       construct the specific value. Supported flags given by option:
1687 *       p page flags (see struct page) given as pointer to unsigned long
1688 *       g gfp flags (GFP_* and __GFP_*) given as pointer to gfp_t
1689 *       v vma flags (VM_*) given as pointer to unsigned long
1690 * - 'O' For a kobject based struct. Must be one of the following:
1691 *       - 'OF[fnpPcCF]'  For a device tree object
1692 *                        Without any optional arguments prints the full_name
1693 *                        f device node full_name
1694 *                        n device node name
1695 *                        p device node phandle
1696 *                        P device node path spec (name + @unit)
1697 *                        F device node flags
1698 *                        c major compatible string
1699 *                        C full compatible string
1700 *
1701 * ** Please update also Documentation/printk-formats.txt when making changes **
1702 *
1703 * Note: The difference between 'S' and 'F' is that on ia64 and ppc64
1704 * function pointers are really function descriptors, which contain a
1705 * pointer to the real address.
1706 */
1707static noinline_for_stack
1708char *pointer(const char *fmt, char *buf, char *end, void *ptr,
1709              struct printf_spec spec)
1710{
1711        const int default_width = 2 * sizeof(void *);
1712
1713        if (!ptr && *fmt != 'K') {
1714                /*
1715                 * Print (null) with the same width as a pointer so it makes
1716                 * tabular output look nice.
1717                 */
1718                if (spec.field_width == -1)
1719                        spec.field_width = default_width;
1720                return string(buf, end, "(null)", spec);
1721        }
1722
1723        switch (*fmt) {
1724        case 'F':
1725        case 'f':
1726                ptr = dereference_function_descriptor(ptr);
1727                /* Fallthrough */
1728        case 'S':
1729        case 's':
1730        case 'B':
1731                return symbol_string(buf, end, ptr, spec, fmt);
1732        case 'R':
1733        case 'r':
1734                return resource_string(buf, end, ptr, spec, fmt);
1735        case 'h':
1736                return hex_string(buf, end, ptr, spec, fmt);
1737        case 'b':
1738                switch (fmt[1]) {
1739                case 'l':
1740                        return bitmap_list_string(buf, end, ptr, spec, fmt);
1741                default:
1742                        return bitmap_string(buf, end, ptr, spec, fmt);
1743                }
1744        case 'M':                       /* Colon separated: 00:01:02:03:04:05 */
1745        case 'm':                       /* Contiguous: 000102030405 */
1746                                        /* [mM]F (FDDI) */
1747                                        /* [mM]R (Reverse order; Bluetooth) */
1748                return mac_address_string(buf, end, ptr, spec, fmt);
1749        case 'I':                       /* Formatted IP supported
1750                                         * 4:   1.2.3.4
1751                                         * 6:   0001:0203:...:0708
1752                                         * 6c:  1::708 or 1::1.2.3.4
1753                                         */
1754        case 'i':                       /* Contiguous:
1755                                         * 4:   001.002.003.004
1756                                         * 6:   000102...0f
1757                                         */
1758                switch (fmt[1]) {
1759                case '6':
1760                        return ip6_addr_string(buf, end, ptr, spec, fmt);
1761                case '4':
1762                        return ip4_addr_string(buf, end, ptr, spec, fmt);
1763                case 'S': {
1764                        const union {
1765                                struct sockaddr         raw;
1766                                struct sockaddr_in      v4;
1767                                struct sockaddr_in6     v6;
1768                        } *sa = ptr;
1769
1770                        switch (sa->raw.sa_family) {
1771                        case AF_INET:
1772                                return ip4_addr_string_sa(buf, end, &sa->v4, spec, fmt);
1773                        case AF_INET6:
1774                                return ip6_addr_string_sa(buf, end, &sa->v6, spec, fmt);
1775                        default:
1776                                return string(buf, end, "(invalid address)", spec);
1777                        }}
1778                }
1779                break;
1780        case 'E':
1781                return escaped_string(buf, end, ptr, spec, fmt);
1782        case 'U':
1783                return uuid_string(buf, end, ptr, spec, fmt);
1784        case 'V':
1785                {
1786                        va_list va;
1787
1788                        va_copy(va, *((struct va_format *)ptr)->va);
1789                        buf += vsnprintf(buf, end > buf ? end - buf : 0,
1790                                         ((struct va_format *)ptr)->fmt, va);
1791                        va_end(va);
1792                        return buf;
1793                }
1794        case 'K':
1795                switch (kptr_restrict) {
1796                case 0:
1797                        /* Always print %pK values */
1798                        break;
1799                case 1: {
1800                        const struct cred *cred;
1801
1802                        /*
1803                         * kptr_restrict==1 cannot be used in IRQ context
1804                         * because its test for CAP_SYSLOG would be meaningless.
1805                         */
1806                        if (in_irq() || in_serving_softirq() || in_nmi()) {
1807                                if (spec.field_width == -1)
1808                                        spec.field_width = default_width;
1809                                return string(buf, end, "pK-error", spec);
1810                        }
1811
1812                        /*
1813                         * Only print the real pointer value if the current
1814                         * process has CAP_SYSLOG and is running with the
1815                         * same credentials it started with. This is because
1816                         * access to files is checked at open() time, but %pK
1817                         * checks permission at read() time. We don't want to
1818                         * leak pointer values if a binary opens a file using
1819                         * %pK and then elevates privileges before reading it.
1820                         */
1821                        cred = current_cred();
1822                        if (!has_capability_noaudit(current, CAP_SYSLOG) ||
1823                            !uid_eq(cred->euid, cred->uid) ||
1824                            !gid_eq(cred->egid, cred->gid))
1825                                ptr = NULL;
1826                        break;
1827                }
1828                case 2:
1829                default:
1830                        /* Always print 0's for %pK */
1831                        ptr = NULL;
1832                        break;
1833                }
1834                break;
1835
1836        case 'N':
1837                return netdev_bits(buf, end, ptr, fmt);
1838        case 'a':
1839                return address_val(buf, end, ptr, fmt);
1840        case 'd':
1841                return dentry_name(buf, end, ptr, spec, fmt);
1842        case 'C':
1843                return clock(buf, end, ptr, spec, fmt);
1844        case 'D':
1845                return dentry_name(buf, end,
1846                                   ((const struct file *)ptr)->f_path.dentry,
1847                                   spec, fmt);
1848#ifdef CONFIG_BLOCK
1849        case 'g':
1850                return bdev_name(buf, end, ptr, spec, fmt);
1851#endif
1852
1853        case 'G':
1854                return flags_string(buf, end, ptr, fmt);
1855        case 'O':
1856                switch (fmt[1]) {
1857                case 'F':
1858                        return device_node_string(buf, end, ptr, spec, fmt + 1);
1859                }
1860        }
1861        spec.flags |= SMALL;
1862        if (spec.field_width == -1) {
1863                spec.field_width = default_width;
1864                spec.flags |= ZEROPAD;
1865        }
1866        spec.base = 16;
1867
1868        return number(buf, end, (unsigned long) ptr, spec);
1869}
1870
1871/*
1872 * Helper function to decode printf style format.
1873 * Each call decode a token from the format and return the
1874 * number of characters read (or likely the delta where it wants
1875 * to go on the next call).
1876 * The decoded token is returned through the parameters
1877 *
1878 * 'h', 'l', or 'L' for integer fields
1879 * 'z' support added 23/7/1999 S.H.
1880 * 'z' changed to 'Z' --davidm 1/25/99
1881 * 'Z' changed to 'z' --adobriyan 2017-01-25
1882 * 't' added for ptrdiff_t
1883 *
1884 * @fmt: the format string
1885 * @type of the token returned
1886 * @flags: various flags such as +, -, # tokens..
1887 * @field_width: overwritten width
1888 * @base: base of the number (octal, hex, ...)
1889 * @precision: precision of a number
1890 * @qualifier: qualifier of a number (long, size_t, ...)
1891 */
1892static noinline_for_stack
1893int format_decode(const char *fmt, struct printf_spec *spec)
1894{
1895        const char *start = fmt;
1896        char qualifier;
1897
1898        /* we finished early by reading the field width */
1899        if (spec->type == FORMAT_TYPE_WIDTH) {
1900                if (spec->field_width < 0) {
1901                        spec->field_width = -spec->field_width;
1902                        spec->flags |= LEFT;
1903                }
1904                spec->type = FORMAT_TYPE_NONE;
1905                goto precision;
1906        }
1907
1908        /* we finished early by reading the precision */
1909        if (spec->type == FORMAT_TYPE_PRECISION) {
1910                if (spec->precision < 0)
1911                        spec->precision = 0;
1912
1913                spec->type = FORMAT_TYPE_NONE;
1914                goto qualifier;
1915        }
1916
1917        /* By default */
1918        spec->type = FORMAT_TYPE_NONE;
1919
1920        for (; *fmt ; ++fmt) {
1921                if (*fmt == '%')
1922                        break;
1923        }
1924
1925        /* Return the current non-format string */
1926        if (fmt != start || !*fmt)
1927                return fmt - start;
1928
1929        /* Process flags */
1930        spec->flags = 0;
1931
1932        while (1) { /* this also skips first '%' */
1933                bool found = true;
1934
1935                ++fmt;
1936
1937                switch (*fmt) {
1938                case '-': spec->flags |= LEFT;    break;
1939                case '+': spec->flags |= PLUS;    break;
1940                case ' ': spec->flags |= SPACE;   break;
1941                case '#': spec->flags |= SPECIAL; break;
1942                case '0': spec->flags |= ZEROPAD; break;
1943                default:  found = false;
1944                }
1945
1946                if (!found)
1947                        break;
1948        }
1949
1950        /* get field width */
1951        spec->field_width = -1;
1952
1953        if (isdigit(*fmt))
1954                spec->field_width = skip_atoi(&fmt);
1955        else if (*fmt == '*') {
1956                /* it's the next argument */
1957                spec->type = FORMAT_TYPE_WIDTH;
1958                return ++fmt - start;
1959        }
1960
1961precision:
1962        /* get the precision */
1963        spec->precision = -1;
1964        if (*fmt == '.') {
1965                ++fmt;
1966                if (isdigit(*fmt)) {
1967                        spec->precision = skip_atoi(&fmt);
1968                        if (spec->precision < 0)
1969                                spec->precision = 0;
1970                } else if (*fmt == '*') {
1971                        /* it's the next argument */
1972                        spec->type = FORMAT_TYPE_PRECISION;
1973                        return ++fmt - start;
1974                }
1975        }
1976
1977qualifier:
1978        /* get the conversion qualifier */
1979        qualifier = 0;
1980        if (*fmt == 'h' || _tolower(*fmt) == 'l' ||
1981            *fmt == 'z' || *fmt == 't') {
1982                qualifier = *fmt++;
1983                if (unlikely(qualifier == *fmt)) {
1984                        if (qualifier == 'l') {
1985                                qualifier = 'L';
1986                                ++fmt;
1987                        } else if (qualifier == 'h') {
1988                                qualifier = 'H';
1989                                ++fmt;
1990                        }
1991                }
1992        }
1993
1994        /* default base */
1995        spec->base = 10;
1996        switch (*fmt) {
1997        case 'c':
1998                spec->type = FORMAT_TYPE_CHAR;
1999                return ++fmt - start;
2000
2001        case 's':
2002                spec->type = FORMAT_TYPE_STR;
2003                return ++fmt - start;
2004
2005        case 'p':
2006                spec->type = FORMAT_TYPE_PTR;
2007                return ++fmt - start;
2008
2009        case '%':
2010                spec->type = FORMAT_TYPE_PERCENT_CHAR;
2011                return ++fmt - start;
2012
2013        /* integer number formats - set up the flags and "break" */
2014        case 'o':
2015                spec->base = 8;
2016                break;
2017
2018        case 'x':
2019                spec->flags |= SMALL;
2020
2021        case 'X':
2022                spec->base = 16;
2023                break;
2024
2025        case 'd':
2026        case 'i':
2027                spec->flags |= SIGN;
2028        case 'u':
2029                break;
2030
2031        case 'n':
2032                /*
2033                 * Since %n poses a greater security risk than
2034                 * utility, treat it as any other invalid or
2035                 * unsupported format specifier.
2036                 */
2037                /* Fall-through */
2038
2039        default:
2040                WARN_ONCE(1, "Please remove unsupported %%%c in format string\n", *fmt);
2041                spec->type = FORMAT_TYPE_INVALID;
2042                return fmt - start;
2043        }
2044
2045        if (qualifier == 'L')
2046                spec->type = FORMAT_TYPE_LONG_LONG;
2047        else if (qualifier == 'l') {
2048                BUILD_BUG_ON(FORMAT_TYPE_ULONG + SIGN != FORMAT_TYPE_LONG);
2049                spec->type = FORMAT_TYPE_ULONG + (spec->flags & SIGN);
2050        } else if (qualifier == 'z') {
2051                spec->type = FORMAT_TYPE_SIZE_T;
2052        } else if (qualifier == 't') {
2053                spec->type = FORMAT_TYPE_PTRDIFF;
2054        } else if (qualifier == 'H') {
2055                BUILD_BUG_ON(FORMAT_TYPE_UBYTE + SIGN != FORMAT_TYPE_BYTE);
2056                spec->type = FORMAT_TYPE_UBYTE + (spec->flags & SIGN);
2057        } else if (qualifier == 'h') {
2058                BUILD_BUG_ON(FORMAT_TYPE_USHORT + SIGN != FORMAT_TYPE_SHORT);
2059                spec->type = FORMAT_TYPE_USHORT + (spec->flags & SIGN);
2060        } else {
2061                BUILD_BUG_ON(FORMAT_TYPE_UINT + SIGN != FORMAT_TYPE_INT);
2062                spec->type = FORMAT_TYPE_UINT + (spec->flags & SIGN);
2063        }
2064
2065        return ++fmt - start;
2066}
2067
2068static void
2069set_field_width(struct printf_spec *spec, int width)
2070{
2071        spec->field_width = width;
2072        if (WARN_ONCE(spec->field_width != width, "field width %d too large", width)) {
2073                spec->field_width = clamp(width, -FIELD_WIDTH_MAX, FIELD_WIDTH_MAX);
2074        }
2075}
2076
2077static void
2078set_precision(struct printf_spec *spec, int prec)
2079{
2080        spec->precision = prec;
2081        if (WARN_ONCE(spec->precision != prec, "precision %d too large", prec)) {
2082                spec->precision = clamp(prec, 0, PRECISION_MAX);
2083        }
2084}
2085
2086/**
2087 * vsnprintf - Format a string and place it in a buffer
2088 * @buf: The buffer to place the result into
2089 * @size: The size of the buffer, including the trailing null space
2090 * @fmt: The format string to use
2091 * @args: Arguments for the format string
2092 *
2093 * This function generally follows C99 vsnprintf, but has some
2094 * extensions and a few limitations:
2095 *
2096 *  - ``%n`` is unsupported
2097 *  - ``%p*`` is handled by pointer()
2098 *
2099 * See pointer() or Documentation/printk-formats.txt for more
2100 * extensive description.
2101 *
2102 * **Please update the documentation in both places when making changes**
2103 *
2104 * The return value is the number of characters which would
2105 * be generated for the given input, excluding the trailing
2106 * '\0', as per ISO C99. If you want to have the exact
2107 * number of characters written into @buf as return value
2108 * (not including the trailing '\0'), use vscnprintf(). If the
2109 * return is greater than or equal to @size, the resulting
2110 * string is truncated.
2111 *
2112 * If you're not already dealing with a va_list consider using snprintf().
2113 */
2114int vsnprintf(char *buf, size_t size, const char *fmt, va_list args)
2115{
2116        unsigned long long num;
2117        char *str, *end;
2118        struct printf_spec spec = {0};
2119
2120        /* Reject out-of-range values early.  Large positive sizes are
2121           used for unknown buffer sizes. */
2122        if (WARN_ON_ONCE(size > INT_MAX))
2123                return 0;
2124
2125        str = buf;
2126        end = buf + size;
2127
2128        /* Make sure end is always >= buf */
2129        if (end < buf) {
2130                end = ((void *)-1);
2131                size = end - buf;
2132        }
2133
2134        while (*fmt) {
2135                const char *old_fmt = fmt;
2136                int read = format_decode(fmt, &spec);
2137
2138                fmt += read;
2139
2140                switch (spec.type) {
2141                case FORMAT_TYPE_NONE: {
2142                        int copy = read;
2143                        if (str < end) {
2144                                if (copy > end - str)
2145                                        copy = end - str;
2146                                memcpy(str, old_fmt, copy);
2147                        }
2148                        str += read;
2149                        break;
2150                }
2151
2152                case FORMAT_TYPE_WIDTH:
2153                        set_field_width(&spec, va_arg(args, int));
2154                        break;
2155
2156                case FORMAT_TYPE_PRECISION:
2157                        set_precision(&spec, va_arg(args, int));
2158                        break;
2159
2160                case FORMAT_TYPE_CHAR: {
2161                        char c;
2162
2163                        if (!(spec.flags & LEFT)) {
2164                                while (--spec.field_width > 0) {
2165                                        if (str < end)
2166                                                *str = ' ';
2167                                        ++str;
2168
2169                                }
2170                        }
2171                        c = (unsigned char) va_arg(args, int);
2172                        if (str < end)
2173                                *str = c;
2174                        ++str;
2175                        while (--spec.field_width > 0) {
2176                                if (str < end)
2177                                        *str = ' ';
2178                                ++str;
2179                        }
2180                        break;
2181                }
2182
2183                case FORMAT_TYPE_STR:
2184                        str = string(str, end, va_arg(args, char *), spec);
2185                        break;
2186
2187                case FORMAT_TYPE_PTR:
2188                        str = pointer(fmt, str, end, va_arg(args, void *),
2189                                      spec);
2190                        while (isalnum(*fmt))
2191                                fmt++;
2192                        break;
2193
2194                case FORMAT_TYPE_PERCENT_CHAR:
2195                        if (str < end)
2196                                *str = '%';
2197                        ++str;
2198                        break;
2199
2200                case FORMAT_TYPE_INVALID:
2201                        /*
2202                         * Presumably the arguments passed gcc's type
2203                         * checking, but there is no safe or sane way
2204                         * for us to continue parsing the format and
2205                         * fetching from the va_list; the remaining
2206                         * specifiers and arguments would be out of
2207                         * sync.
2208                         */
2209                        goto out;
2210
2211                default:
2212                        switch (spec.type) {
2213                        case FORMAT_TYPE_LONG_LONG:
2214                                num = va_arg(args, long long);
2215                                break;
2216                        case FORMAT_TYPE_ULONG:
2217                                num = va_arg(args, unsigned long);
2218                                break;
2219                        case FORMAT_TYPE_LONG:
2220                                num = va_arg(args, long);
2221                                break;
2222                        case FORMAT_TYPE_SIZE_T:
2223                                if (spec.flags & SIGN)
2224                                        num = va_arg(args, ssize_t);
2225                                else
2226                                        num = va_arg(args, size_t);
2227                                break;
2228                        case FORMAT_TYPE_PTRDIFF:
2229                                num = va_arg(args, ptrdiff_t);
2230                                break;
2231                        case FORMAT_TYPE_UBYTE:
2232                                num = (unsigned char) va_arg(args, int);
2233                                break;
2234                        case FORMAT_TYPE_BYTE:
2235                                num = (signed char) va_arg(args, int);
2236                                break;
2237                        case FORMAT_TYPE_USHORT:
2238                                num = (unsigned short) va_arg(args, int);
2239                                break;
2240                        case FORMAT_TYPE_SHORT:
2241                                num = (short) va_arg(args, int);
2242                                break;
2243                        case FORMAT_TYPE_INT:
2244                                num = (int) va_arg(args, int);
2245                                break;
2246                        default:
2247                                num = va_arg(args, unsigned int);
2248                        }
2249
2250                        str = number(str, end, num, spec);
2251                }
2252        }
2253
2254out:
2255        if (size > 0) {
2256                if (str < end)
2257                        *str = '\0';
2258                else
2259                        end[-1] = '\0';
2260        }
2261
2262        /* the trailing null byte doesn't count towards the total */
2263        return str-buf;
2264
2265}
2266EXPORT_SYMBOL(vsnprintf);
2267
2268/**
2269 * vscnprintf - Format a string and place it in a buffer
2270 * @buf: The buffer to place the result into
2271 * @size: The size of the buffer, including the trailing null space
2272 * @fmt: The format string to use
2273 * @args: Arguments for the format string
2274 *
2275 * The return value is the number of characters which have been written into
2276 * the @buf not including the trailing '\0'. If @size is == 0 the function
2277 * returns 0.
2278 *
2279 * If you're not already dealing with a va_list consider using scnprintf().
2280 *
2281 * See the vsnprintf() documentation for format string extensions over C99.
2282 */
2283int vscnprintf(char *buf, size_t size, const char *fmt, va_list args)
2284{
2285        int i;
2286
2287        i = vsnprintf(buf, size, fmt, args);
2288
2289        if (likely(i < size))
2290                return i;
2291        if (size != 0)
2292                return size - 1;
2293        return 0;
2294}
2295EXPORT_SYMBOL(vscnprintf);
2296
2297/**
2298 * snprintf - Format a string and place it in a buffer
2299 * @buf: The buffer to place the result into
2300 * @size: The size of the buffer, including the trailing null space
2301 * @fmt: The format string to use
2302 * @...: Arguments for the format string
2303 *
2304 * The return value is the number of characters which would be
2305 * generated for the given input, excluding the trailing null,
2306 * as per ISO C99.  If the return is greater than or equal to
2307 * @size, the resulting string is truncated.
2308 *
2309 * See the vsnprintf() documentation for format string extensions over C99.
2310 */
2311int snprintf(char *buf, size_t size, const char *fmt, ...)
2312{
2313        va_list args;
2314        int i;
2315
2316        va_start(args, fmt);
2317        i = vsnprintf(buf, size, fmt, args);
2318        va_end(args);
2319
2320        return i;
2321}
2322EXPORT_SYMBOL(snprintf);
2323
2324/**
2325 * scnprintf - Format a string and place it in a buffer
2326 * @buf: The buffer to place the result into
2327 * @size: The size of the buffer, including the trailing null space
2328 * @fmt: The format string to use
2329 * @...: Arguments for the format string
2330 *
2331 * The return value is the number of characters written into @buf not including
2332 * the trailing '\0'. If @size is == 0 the function returns 0.
2333 */
2334
2335int scnprintf(char *buf, size_t size, const char *fmt, ...)
2336{
2337        va_list args;
2338        int i;
2339
2340        va_start(args, fmt);
2341        i = vscnprintf(buf, size, fmt, args);
2342        va_end(args);
2343
2344        return i;
2345}
2346EXPORT_SYMBOL(scnprintf);
2347
2348/**
2349 * vsprintf - Format a string and place it in a buffer
2350 * @buf: The buffer to place the result into
2351 * @fmt: The format string to use
2352 * @args: Arguments for the format string
2353 *
2354 * The function returns the number of characters written
2355 * into @buf. Use vsnprintf() or vscnprintf() in order to avoid
2356 * buffer overflows.
2357 *
2358 * If you're not already dealing with a va_list consider using sprintf().
2359 *
2360 * See the vsnprintf() documentation for format string extensions over C99.
2361 */
2362int vsprintf(char *buf, const char *fmt, va_list args)
2363{
2364        return vsnprintf(buf, INT_MAX, fmt, args);
2365}
2366EXPORT_SYMBOL(vsprintf);
2367
2368/**
2369 * sprintf - Format a string and place it in a buffer
2370 * @buf: The buffer to place the result into
2371 * @fmt: The format string to use
2372 * @...: Arguments for the format string
2373 *
2374 * The function returns the number of characters written
2375 * into @buf. Use snprintf() or scnprintf() in order to avoid
2376 * buffer overflows.
2377 *
2378 * See the vsnprintf() documentation for format string extensions over C99.
2379 */
2380int sprintf(char *buf, const char *fmt, ...)
2381{
2382        va_list args;
2383        int i;
2384
2385        va_start(args, fmt);
2386        i = vsnprintf(buf, INT_MAX, fmt, args);
2387        va_end(args);
2388
2389        return i;
2390}
2391EXPORT_SYMBOL(sprintf);
2392
2393#ifdef CONFIG_BINARY_PRINTF
2394/*
2395 * bprintf service:
2396 * vbin_printf() - VA arguments to binary data
2397 * bstr_printf() - Binary data to text string
2398 */
2399
2400/**
2401 * vbin_printf - Parse a format string and place args' binary value in a buffer
2402 * @bin_buf: The buffer to place args' binary value
2403 * @size: The size of the buffer(by words(32bits), not characters)
2404 * @fmt: The format string to use
2405 * @args: Arguments for the format string
2406 *
2407 * The format follows C99 vsnprintf, except %n is ignored, and its argument
2408 * is skipped.
2409 *
2410 * The return value is the number of words(32bits) which would be generated for
2411 * the given input.
2412 *
2413 * NOTE:
2414 * If the return value is greater than @size, the resulting bin_buf is NOT
2415 * valid for bstr_printf().
2416 */
2417int vbin_printf(u32 *bin_buf, size_t size, const char *fmt, va_list args)
2418{
2419        struct printf_spec spec = {0};
2420        char *str, *end;
2421
2422        str = (char *)bin_buf;
2423        end = (char *)(bin_buf + size);
2424
2425#define save_arg(type)                                                  \
2426do {                                                                    \
2427        if (sizeof(type) == 8) {                                        \
2428                unsigned long long value;                               \
2429                str = PTR_ALIGN(str, sizeof(u32));                      \
2430                value = va_arg(args, unsigned long long);               \
2431                if (str + sizeof(type) <= end) {                        \
2432                        *(u32 *)str = *(u32 *)&value;                   \
2433                        *(u32 *)(str + 4) = *((u32 *)&value + 1);       \
2434                }                                                       \
2435        } else {                                                        \
2436                unsigned long value;                                    \
2437                str = PTR_ALIGN(str, sizeof(type));                     \
2438                value = va_arg(args, int);                              \
2439                if (str + sizeof(type) <= end)                          \
2440                        *(typeof(type) *)str = (type)value;             \
2441        }                                                               \
2442        str += sizeof(type);                                            \
2443} while (0)
2444
2445        while (*fmt) {
2446                int read = format_decode(fmt, &spec);
2447
2448                fmt += read;
2449
2450                switch (spec.type) {
2451                case FORMAT_TYPE_NONE:
2452                case FORMAT_TYPE_PERCENT_CHAR:
2453                        break;
2454                case FORMAT_TYPE_INVALID:
2455                        goto out;
2456
2457                case FORMAT_TYPE_WIDTH:
2458                case FORMAT_TYPE_PRECISION:
2459                        save_arg(int);
2460                        break;
2461
2462                case FORMAT_TYPE_CHAR:
2463                        save_arg(char);
2464                        break;
2465
2466                case FORMAT_TYPE_STR: {
2467                        const char *save_str = va_arg(args, char *);
2468                        size_t len;
2469
2470                        if ((unsigned long)save_str > (unsigned long)-PAGE_SIZE
2471                                        || (unsigned long)save_str < PAGE_SIZE)
2472                                save_str = "(null)";
2473                        len = strlen(save_str) + 1;
2474                        if (str + len < end)
2475                                memcpy(str, save_str, len);
2476                        str += len;
2477                        break;
2478                }
2479
2480                case FORMAT_TYPE_PTR:
2481                        save_arg(void *);
2482                        /* skip all alphanumeric pointer suffixes */
2483                        while (isalnum(*fmt))
2484                                fmt++;
2485                        break;
2486
2487                default:
2488                        switch (spec.type) {
2489
2490                        case FORMAT_TYPE_LONG_LONG:
2491                                save_arg(long long);
2492                                break;
2493                        case FORMAT_TYPE_ULONG:
2494                        case FORMAT_TYPE_LONG:
2495                                save_arg(unsigned long);
2496                                break;
2497                        case FORMAT_TYPE_SIZE_T:
2498                                save_arg(size_t);
2499                                break;
2500                        case FORMAT_TYPE_PTRDIFF:
2501                                save_arg(ptrdiff_t);
2502                                break;
2503                        case FORMAT_TYPE_UBYTE:
2504                        case FORMAT_TYPE_BYTE:
2505                                save_arg(char);
2506                                break;
2507                        case FORMAT_TYPE_USHORT:
2508                        case FORMAT_TYPE_SHORT:
2509                                save_arg(short);
2510                                break;
2511                        default:
2512                                save_arg(int);
2513                        }
2514                }
2515        }
2516
2517out:
2518        return (u32 *)(PTR_ALIGN(str, sizeof(u32))) - bin_buf;
2519#undef save_arg
2520}
2521EXPORT_SYMBOL_GPL(vbin_printf);
2522
2523/**
2524 * bstr_printf - Format a string from binary arguments and place it in a buffer
2525 * @buf: The buffer to place the result into
2526 * @size: The size of the buffer, including the trailing null space
2527 * @fmt: The format string to use
2528 * @bin_buf: Binary arguments for the format string
2529 *
2530 * This function like C99 vsnprintf, but the difference is that vsnprintf gets
2531 * arguments from stack, and bstr_printf gets arguments from @bin_buf which is
2532 * a binary buffer that generated by vbin_printf.
2533 *
2534 * The format follows C99 vsnprintf, but has some extensions:
2535 *  see vsnprintf comment for details.
2536 *
2537 * The return value is the number of characters which would
2538 * be generated for the given input, excluding the trailing
2539 * '\0', as per ISO C99. If you want to have the exact
2540 * number of characters written into @buf as return value
2541 * (not including the trailing '\0'), use vscnprintf(). If the
2542 * return is greater than or equal to @size, the resulting
2543 * string is truncated.
2544 */
2545int bstr_printf(char *buf, size_t size, const char *fmt, const u32 *bin_buf)
2546{
2547        struct printf_spec spec = {0};
2548        char *str, *end;
2549        const char *args = (const char *)bin_buf;
2550
2551        if (WARN_ON_ONCE(size > INT_MAX))
2552                return 0;
2553
2554        str = buf;
2555        end = buf + size;
2556
2557#define get_arg(type)                                                   \
2558({                                                                      \
2559        typeof(type) value;                                             \
2560        if (sizeof(type) == 8) {                                        \
2561                args = PTR_ALIGN(args, sizeof(u32));                    \
2562                *(u32 *)&value = *(u32 *)args;                          \
2563                *((u32 *)&value + 1) = *(u32 *)(args + 4);              \
2564        } else {                                                        \
2565                args = PTR_ALIGN(args, sizeof(type));                   \
2566                value = *(typeof(type) *)args;                          \
2567        }                                                               \
2568        args += sizeof(type);                                           \
2569        value;                                                          \
2570})
2571
2572        /* Make sure end is always >= buf */
2573        if (end < buf) {
2574                end = ((void *)-1);
2575                size = end - buf;
2576        }
2577
2578        while (*fmt) {
2579                const char *old_fmt = fmt;
2580                int read = format_decode(fmt, &spec);
2581
2582                fmt += read;
2583
2584                switch (spec.type) {
2585                case FORMAT_TYPE_NONE: {
2586                        int copy = read;
2587                        if (str < end) {
2588                                if (copy > end - str)
2589                                        copy = end - str;
2590                                memcpy(str, old_fmt, copy);
2591                        }
2592                        str += read;
2593                        break;
2594                }
2595
2596                case FORMAT_TYPE_WIDTH:
2597                        set_field_width(&spec, get_arg(int));
2598                        break;
2599
2600                case FORMAT_TYPE_PRECISION:
2601                        set_precision(&spec, get_arg(int));
2602                        break;
2603
2604                case FORMAT_TYPE_CHAR: {
2605                        char c;
2606
2607                        if (!(spec.flags & LEFT)) {
2608                                while (--spec.field_width > 0) {
2609                                        if (str < end)
2610                                                *str = ' ';
2611                                        ++str;
2612                                }
2613                        }
2614                        c = (unsigned char) get_arg(char);
2615                        if (str < end)
2616                                *str = c;
2617                        ++str;
2618                        while (--spec.field_width > 0) {
2619                                if (str < end)
2620                                        *str = ' ';
2621                                ++str;
2622                        }
2623                        break;
2624                }
2625
2626                case FORMAT_TYPE_STR: {
2627                        const char *str_arg = args;
2628                        args += strlen(str_arg) + 1;
2629                        str = string(str, end, (char *)str_arg, spec);
2630                        break;
2631                }
2632
2633                case FORMAT_TYPE_PTR:
2634                        str = pointer(fmt, str, end, get_arg(void *), spec);
2635                        while (isalnum(*fmt))
2636                                fmt++;
2637                        break;
2638
2639                case FORMAT_TYPE_PERCENT_CHAR:
2640                        if (str < end)
2641                                *str = '%';
2642                        ++str;
2643                        break;
2644
2645                case FORMAT_TYPE_INVALID:
2646                        goto out;
2647
2648                default: {
2649                        unsigned long long num;
2650
2651                        switch (spec.type) {
2652
2653                        case FORMAT_TYPE_LONG_LONG:
2654                                num = get_arg(long long);
2655                                break;
2656                        case FORMAT_TYPE_ULONG:
2657                        case FORMAT_TYPE_LONG:
2658                                num = get_arg(unsigned long);
2659                                break;
2660                        case FORMAT_TYPE_SIZE_T:
2661                                num = get_arg(size_t);
2662                                break;
2663                        case FORMAT_TYPE_PTRDIFF:
2664                                num = get_arg(ptrdiff_t);
2665                                break;
2666                        case FORMAT_TYPE_UBYTE:
2667                                num = get_arg(unsigned char);
2668                                break;
2669                        case FORMAT_TYPE_BYTE:
2670                                num = get_arg(signed char);
2671                                break;
2672                        case FORMAT_TYPE_USHORT:
2673                                num = get_arg(unsigned short);
2674                                break;
2675                        case FORMAT_TYPE_SHORT:
2676                                num = get_arg(short);
2677                                break;
2678                        case FORMAT_TYPE_UINT:
2679                                num = get_arg(unsigned int);
2680                                break;
2681                        default:
2682                                num = get_arg(int);
2683                        }
2684
2685                        str = number(str, end, num, spec);
2686                } /* default: */
2687                } /* switch(spec.type) */
2688        } /* while(*fmt) */
2689
2690out:
2691        if (size > 0) {
2692                if (str < end)
2693                        *str = '\0';
2694                else
2695                        end[-1] = '\0';
2696        }
2697
2698#undef get_arg
2699
2700        /* the trailing null byte doesn't count towards the total */
2701        return str - buf;
2702}
2703EXPORT_SYMBOL_GPL(bstr_printf);
2704
2705/**
2706 * bprintf - Parse a format string and place args' binary value in a buffer
2707 * @bin_buf: The buffer to place args' binary value
2708 * @size: The size of the buffer(by words(32bits), not characters)
2709 * @fmt: The format string to use
2710 * @...: Arguments for the format string
2711 *
2712 * The function returns the number of words(u32) written
2713 * into @bin_buf.
2714 */
2715int bprintf(u32 *bin_buf, size_t size, const char *fmt, ...)
2716{
2717        va_list args;
2718        int ret;
2719
2720        va_start(args, fmt);
2721        ret = vbin_printf(bin_buf, size, fmt, args);
2722        va_end(args);
2723
2724        return ret;
2725}
2726EXPORT_SYMBOL_GPL(bprintf);
2727
2728#endif /* CONFIG_BINARY_PRINTF */
2729
2730/**
2731 * vsscanf - Unformat a buffer into a list of arguments
2732 * @buf:        input buffer
2733 * @fmt:        format of buffer
2734 * @args:       arguments
2735 */
2736int vsscanf(const char *buf, const char *fmt, va_list args)
2737{
2738        const char *str = buf;
2739        char *next;
2740        char digit;
2741        int num = 0;
2742        u8 qualifier;
2743        unsigned int base;
2744        union {
2745                long long s;
2746                unsigned long long u;
2747        } val;
2748        s16 field_width;
2749        bool is_sign;
2750
2751        while (*fmt) {
2752                /* skip any white space in format */
2753                /* white space in format matchs any amount of
2754                 * white space, including none, in the input.
2755                 */
2756                if (isspace(*fmt)) {
2757                        fmt = skip_spaces(++fmt);
2758                        str = skip_spaces(str);
2759                }
2760
2761                /* anything that is not a conversion must match exactly */
2762                if (*fmt != '%' && *fmt) {
2763                        if (*fmt++ != *str++)
2764                                break;
2765                        continue;
2766                }
2767
2768                if (!*fmt)
2769                        break;
2770                ++fmt;
2771
2772                /* skip this conversion.
2773                 * advance both strings to next white space
2774                 */
2775                if (*fmt == '*') {
2776                        if (!*str)
2777                                break;
2778                        while (!isspace(*fmt) && *fmt != '%' && *fmt) {
2779                                /* '%*[' not yet supported, invalid format */
2780                                if (*fmt == '[')
2781                                        return num;
2782                                fmt++;
2783                        }
2784                        while (!isspace(*str) && *str)
2785                                str++;
2786                        continue;
2787                }
2788
2789                /* get field width */
2790                field_width = -1;
2791                if (isdigit(*fmt)) {
2792                        field_width = skip_atoi(&fmt);
2793                        if (field_width <= 0)
2794                                break;
2795                }
2796
2797                /* get conversion qualifier */
2798                qualifier = -1;
2799                if (*fmt == 'h' || _tolower(*fmt) == 'l' ||
2800                    *fmt == 'z') {
2801                        qualifier = *fmt++;
2802                        if (unlikely(qualifier == *fmt)) {
2803                                if (qualifier == 'h') {
2804                                        qualifier = 'H';
2805                                        fmt++;
2806                                } else if (qualifier == 'l') {
2807                                        qualifier = 'L';
2808                                        fmt++;
2809                                }
2810                        }
2811                }
2812
2813                if (!*fmt)
2814                        break;
2815
2816                if (*fmt == 'n') {
2817                        /* return number of characters read so far */
2818                        *va_arg(args, int *) = str - buf;
2819                        ++fmt;
2820                        continue;
2821                }
2822
2823                if (!*str)
2824                        break;
2825
2826                base = 10;
2827                is_sign = false;
2828
2829                switch (*fmt++) {
2830                case 'c':
2831                {
2832                        char *s = (char *)va_arg(args, char*);
2833                        if (field_width == -1)
2834                                field_width = 1;
2835                        do {
2836                                *s++ = *str++;
2837                        } while (--field_width > 0 && *str);
2838                        num++;
2839                }
2840                continue;
2841                case 's':
2842                {
2843                        char *s = (char *)va_arg(args, char *);
2844                        if (field_width == -1)
2845                                field_width = SHRT_MAX;
2846                        /* first, skip leading white space in buffer */
2847                        str = skip_spaces(str);
2848
2849                        /* now copy until next white space */
2850                        while (*str && !isspace(*str) && field_width--)
2851                                *s++ = *str++;
2852                        *s = '\0';
2853                        num++;
2854                }
2855                continue;
2856                /*
2857                 * Warning: This implementation of the '[' conversion specifier
2858                 * deviates from its glibc counterpart in the following ways:
2859                 * (1) It does NOT support ranges i.e. '-' is NOT a special
2860                 *     character
2861                 * (2) It cannot match the closing bracket ']' itself
2862                 * (3) A field width is required
2863                 * (4) '%*[' (discard matching input) is currently not supported
2864                 *
2865                 * Example usage:
2866                 * ret = sscanf("00:0a:95","%2[^:]:%2[^:]:%2[^:]",
2867                 *              buf1, buf2, buf3);
2868                 * if (ret < 3)
2869                 *    // etc..
2870                 */
2871                case '[':
2872                {
2873                        char *s = (char *)va_arg(args, char *);
2874                        DECLARE_BITMAP(set, 256) = {0};
2875                        unsigned int len = 0;
2876                        bool negate = (*fmt == '^');
2877
2878                        /* field width is required */
2879                        if (field_width == -1)
2880                                return num;
2881
2882                        if (negate)
2883                                ++fmt;
2884
2885                        for ( ; *fmt && *fmt != ']'; ++fmt, ++len)
2886                                set_bit((u8)*fmt, set);
2887
2888                        /* no ']' or no character set found */
2889                        if (!*fmt || !len)
2890                                return num;
2891                        ++fmt;
2892
2893                        if (negate) {
2894                                bitmap_complement(set, set, 256);
2895                                /* exclude null '\0' byte */
2896                                clear_bit(0, set);
2897                        }
2898
2899                        /* match must be non-empty */
2900                        if (!test_bit((u8)*str, set))
2901                                return num;
2902
2903                        while (test_bit((u8)*str, set) && field_width--)
2904                                *s++ = *str++;
2905                        *s = '\0';
2906                        ++num;
2907                }
2908                continue;
2909                case 'o':
2910                        base = 8;
2911                        break;
2912                case 'x':
2913                case 'X':
2914                        base = 16;
2915                        break;
2916                case 'i':
2917                        base = 0;
2918                case 'd':
2919                        is_sign = true;
2920                case 'u':
2921                        break;
2922                case '%':
2923                        /* looking for '%' in str */
2924                        if (*str++ != '%')
2925                                return num;
2926                        continue;
2927                default:
2928                        /* invalid format; stop here */
2929                        return num;
2930                }
2931
2932                /* have some sort of integer conversion.
2933                 * first, skip white space in buffer.
2934                 */
2935                str = skip_spaces(str);
2936
2937                digit = *str;
2938                if (is_sign && digit == '-')
2939                        digit = *(str + 1);
2940
2941                if (!digit
2942                    || (base == 16 && !isxdigit(digit))
2943                    || (base == 10 && !isdigit(digit))
2944                    || (base == 8 && (!isdigit(digit) || digit > '7'))
2945                    || (base == 0 && !isdigit(digit)))
2946                        break;
2947
2948                if (is_sign)
2949                        val.s = qualifier != 'L' ?
2950                                simple_strtol(str, &next, base) :
2951                                simple_strtoll(str, &next, base);
2952                else
2953                        val.u = qualifier != 'L' ?
2954                                simple_strtoul(str, &next, base) :
2955                                simple_strtoull(str, &next, base);
2956
2957                if (field_width > 0 && next - str > field_width) {
2958                        if (base == 0)
2959                                _parse_integer_fixup_radix(str, &base);
2960                        while (next - str > field_width) {
2961                                if (is_sign)
2962                                        val.s = div_s64(val.s, base);
2963                                else
2964                                        val.u = div_u64(val.u, base);
2965                                --next;
2966                        }
2967                }
2968
2969                switch (qualifier) {
2970                case 'H':       /* that's 'hh' in format */
2971                        if (is_sign)
2972                                *va_arg(args, signed char *) = val.s;
2973                        else
2974                                *va_arg(args, unsigned char *) = val.u;
2975                        break;
2976                case 'h':
2977                        if (is_sign)
2978                                *va_arg(args, short *) = val.s;
2979                        else
2980                                *va_arg(args, unsigned short *) = val.u;
2981                        break;
2982                case 'l':
2983                        if (is_sign)
2984                                *va_arg(args, long *) = val.s;
2985                        else
2986                                *va_arg(args, unsigned long *) = val.u;
2987                        break;
2988                case 'L':
2989                        if (is_sign)
2990                                *va_arg(args, long long *) = val.s;
2991                        else
2992                                *va_arg(args, unsigned long long *) = val.u;
2993                        break;
2994                case 'z':
2995                        *va_arg(args, size_t *) = val.u;
2996                        break;
2997                default:
2998                        if (is_sign)
2999                                *va_arg(args, int *) = val.s;
3000                        else
3001                                *va_arg(args, unsigned int *) = val.u;
3002                        break;
3003                }
3004                num++;
3005
3006                if (!next)
3007                        break;
3008                str = next;
3009        }
3010
3011        return num;
3012}
3013EXPORT_SYMBOL(vsscanf);
3014
3015/**
3016 * sscanf - Unformat a buffer into a list of arguments
3017 * @buf:        input buffer
3018 * @fmt:        formatting of buffer
3019 * @...:        resulting arguments
3020 */
3021int sscanf(const char *buf, const char *fmt, ...)
3022{
3023        va_list args;
3024        int i;
3025
3026        va_start(args, fmt);
3027        i = vsscanf(buf, fmt, args);
3028        va_end(args);
3029
3030        return i;
3031}
3032EXPORT_SYMBOL(sscanf);
3033