linux/lib/vsprintf.c
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   1/*
   2 *  linux/lib/vsprintf.c
   3 *
   4 *  Copyright (C) 1991, 1992  Linus Torvalds
   5 */
   6
   7/* vsprintf.c -- Lars Wirzenius & Linus Torvalds. */
   8/*
   9 * Wirzenius wrote this portably, Torvalds fucked it up :-)
  10 */
  11
  12/*
  13 * Fri Jul 13 2001 Crutcher Dunnavant <crutcher+kernel@datastacks.com>
  14 * - changed to provide snprintf and vsnprintf functions
  15 * So Feb  1 16:51:32 CET 2004 Juergen Quade <quade@hsnr.de>
  16 * - scnprintf and vscnprintf
  17 */
  18
  19#include <stdarg.h>
  20#include <linux/module.h>       /* for KSYM_SYMBOL_LEN */
  21#include <linux/types.h>
  22#include <linux/string.h>
  23#include <linux/ctype.h>
  24#include <linux/kernel.h>
  25#include <linux/kallsyms.h>
  26#include <linux/uaccess.h>
  27#include <linux/ioport.h>
  28#include <net/addrconf.h>
  29
  30#include <asm/page.h>           /* for PAGE_SIZE */
  31#include <asm/div64.h>
  32#include <asm/sections.h>       /* for dereference_function_descriptor() */
  33
  34#include "kstrtox.h"
  35
  36/**
  37 * simple_strtoull - convert a string to an unsigned long long
  38 * @cp: The start of the string
  39 * @endp: A pointer to the end of the parsed string will be placed here
  40 * @base: The number base to use
  41 */
  42unsigned long long simple_strtoull(const char *cp, char **endp, unsigned int base)
  43{
  44        unsigned long long result;
  45        unsigned int rv;
  46
  47        cp = _parse_integer_fixup_radix(cp, &base);
  48        rv = _parse_integer(cp, base, &result);
  49        /* FIXME */
  50        cp += (rv & ~KSTRTOX_OVERFLOW);
  51
  52        if (endp)
  53                *endp = (char *)cp;
  54
  55        return result;
  56}
  57EXPORT_SYMBOL(simple_strtoull);
  58
  59/**
  60 * simple_strtoul - convert a string to an unsigned long
  61 * @cp: The start of the string
  62 * @endp: A pointer to the end of the parsed string will be placed here
  63 * @base: The number base to use
  64 */
  65unsigned long simple_strtoul(const char *cp, char **endp, unsigned int base)
  66{
  67        return simple_strtoull(cp, endp, base);
  68}
  69EXPORT_SYMBOL(simple_strtoul);
  70
  71/**
  72 * simple_strtol - convert a string to a signed long
  73 * @cp: The start of the string
  74 * @endp: A pointer to the end of the parsed string will be placed here
  75 * @base: The number base to use
  76 */
  77long simple_strtol(const char *cp, char **endp, unsigned int base)
  78{
  79        if (*cp == '-')
  80                return -simple_strtoul(cp + 1, endp, base);
  81
  82        return simple_strtoul(cp, endp, base);
  83}
  84EXPORT_SYMBOL(simple_strtol);
  85
  86/**
  87 * simple_strtoll - convert a string to a signed long long
  88 * @cp: The start of the string
  89 * @endp: A pointer to the end of the parsed string will be placed here
  90 * @base: The number base to use
  91 */
  92long long simple_strtoll(const char *cp, char **endp, unsigned int base)
  93{
  94        if (*cp == '-')
  95                return -simple_strtoull(cp + 1, endp, base);
  96
  97        return simple_strtoull(cp, endp, base);
  98}
  99EXPORT_SYMBOL(simple_strtoll);
 100
 101static noinline_for_stack
 102int skip_atoi(const char **s)
 103{
 104        int i = 0;
 105
 106        while (isdigit(**s))
 107                i = i*10 + *((*s)++) - '0';
 108
 109        return i;
 110}
 111
 112/* Decimal conversion is by far the most typical, and is used
 113 * for /proc and /sys data. This directly impacts e.g. top performance
 114 * with many processes running. We optimize it for speed
 115 * using ideas described at <http://www.cs.uiowa.edu/~jones/bcd/divide.html>
 116 * (with permission from the author, Douglas W. Jones).
 117 */
 118
 119#if BITS_PER_LONG != 32 || BITS_PER_LONG_LONG != 64
 120/* Formats correctly any integer in [0, 999999999] */
 121static noinline_for_stack
 122char *put_dec_full9(char *buf, unsigned q)
 123{
 124        unsigned r;
 125
 126        /*
 127         * Possible ways to approx. divide by 10
 128         * (x * 0x1999999a) >> 32 x < 1073741829 (multiply must be 64-bit)
 129         * (x * 0xcccd) >> 19     x <      81920 (x < 262149 when 64-bit mul)
 130         * (x * 0x6667) >> 18     x <      43699
 131         * (x * 0x3334) >> 17     x <      16389
 132         * (x * 0x199a) >> 16     x <      16389
 133         * (x * 0x0ccd) >> 15     x <      16389
 134         * (x * 0x0667) >> 14     x <       2739
 135         * (x * 0x0334) >> 13     x <       1029
 136         * (x * 0x019a) >> 12     x <       1029
 137         * (x * 0x00cd) >> 11     x <       1029 shorter code than * 0x67 (on i386)
 138         * (x * 0x0067) >> 10     x <        179
 139         * (x * 0x0034) >>  9     x <         69 same
 140         * (x * 0x001a) >>  8     x <         69 same
 141         * (x * 0x000d) >>  7     x <         69 same, shortest code (on i386)
 142         * (x * 0x0007) >>  6     x <         19
 143         * See <http://www.cs.uiowa.edu/~jones/bcd/divide.html>
 144         */
 145        r      = (q * (uint64_t)0x1999999a) >> 32;
 146        *buf++ = (q - 10 * r) + '0'; /* 1 */
 147        q      = (r * (uint64_t)0x1999999a) >> 32;
 148        *buf++ = (r - 10 * q) + '0'; /* 2 */
 149        r      = (q * (uint64_t)0x1999999a) >> 32;
 150        *buf++ = (q - 10 * r) + '0'; /* 3 */
 151        q      = (r * (uint64_t)0x1999999a) >> 32;
 152        *buf++ = (r - 10 * q) + '0'; /* 4 */
 153        r      = (q * (uint64_t)0x1999999a) >> 32;
 154        *buf++ = (q - 10 * r) + '0'; /* 5 */
 155        /* Now value is under 10000, can avoid 64-bit multiply */
 156        q      = (r * 0x199a) >> 16;
 157        *buf++ = (r - 10 * q)  + '0'; /* 6 */
 158        r      = (q * 0xcd) >> 11;
 159        *buf++ = (q - 10 * r)  + '0'; /* 7 */
 160        q      = (r * 0xcd) >> 11;
 161        *buf++ = (r - 10 * q) + '0'; /* 8 */
 162        *buf++ = q + '0'; /* 9 */
 163        return buf;
 164}
 165#endif
 166
 167/* Similar to above but do not pad with zeros.
 168 * Code can be easily arranged to print 9 digits too, but our callers
 169 * always call put_dec_full9() instead when the number has 9 decimal digits.
 170 */
 171static noinline_for_stack
 172char *put_dec_trunc8(char *buf, unsigned r)
 173{
 174        unsigned q;
 175
 176        /* Copy of previous function's body with added early returns */
 177        q      = (r * (uint64_t)0x1999999a) >> 32;
 178        *buf++ = (r - 10 * q) + '0'; /* 2 */
 179        if (q == 0)
 180                return buf;
 181        r      = (q * (uint64_t)0x1999999a) >> 32;
 182        *buf++ = (q - 10 * r) + '0'; /* 3 */
 183        if (r == 0)
 184                return buf;
 185        q      = (r * (uint64_t)0x1999999a) >> 32;
 186        *buf++ = (r - 10 * q) + '0'; /* 4 */
 187        if (q == 0)
 188                return buf;
 189        r      = (q * (uint64_t)0x1999999a) >> 32;
 190        *buf++ = (q - 10 * r) + '0'; /* 5 */
 191        if (r == 0)
 192                return buf;
 193        q      = (r * 0x199a) >> 16;
 194        *buf++ = (r - 10 * q)  + '0'; /* 6 */
 195        if (q == 0)
 196                return buf;
 197        r      = (q * 0xcd) >> 11;
 198        *buf++ = (q - 10 * r)  + '0'; /* 7 */
 199        if (r == 0)
 200                return buf;
 201        q      = (r * 0xcd) >> 11;
 202        *buf++ = (r - 10 * q) + '0'; /* 8 */
 203        if (q == 0)
 204                return buf;
 205        *buf++ = q + '0'; /* 9 */
 206        return buf;
 207}
 208
 209/* There are two algorithms to print larger numbers.
 210 * One is generic: divide by 1000000000 and repeatedly print
 211 * groups of (up to) 9 digits. It's conceptually simple,
 212 * but requires a (unsigned long long) / 1000000000 division.
 213 *
 214 * Second algorithm splits 64-bit unsigned long long into 16-bit chunks,
 215 * manipulates them cleverly and generates groups of 4 decimal digits.
 216 * It so happens that it does NOT require long long division.
 217 *
 218 * If long is > 32 bits, division of 64-bit values is relatively easy,
 219 * and we will use the first algorithm.
 220 * If long long is > 64 bits (strange architecture with VERY large long long),
 221 * second algorithm can't be used, and we again use the first one.
 222 *
 223 * Else (if long is 32 bits and long long is 64 bits) we use second one.
 224 */
 225
 226#if BITS_PER_LONG != 32 || BITS_PER_LONG_LONG != 64
 227
 228/* First algorithm: generic */
 229
 230static
 231char *put_dec(char *buf, unsigned long long n)
 232{
 233        if (n >= 100*1000*1000) {
 234                while (n >= 1000*1000*1000)
 235                        buf = put_dec_full9(buf, do_div(n, 1000*1000*1000));
 236                if (n >= 100*1000*1000)
 237                        return put_dec_full9(buf, n);
 238        }
 239        return put_dec_trunc8(buf, n);
 240}
 241
 242#else
 243
 244/* Second algorithm: valid only for 64-bit long longs */
 245
 246static noinline_for_stack
 247char *put_dec_full4(char *buf, unsigned q)
 248{
 249        unsigned r;
 250        r      = (q * 0xcccd) >> 19;
 251        *buf++ = (q - 10 * r) + '0';
 252        q      = (r * 0x199a) >> 16;
 253        *buf++ = (r - 10 * q)  + '0';
 254        r      = (q * 0xcd) >> 11;
 255        *buf++ = (q - 10 * r)  + '0';
 256        *buf++ = r + '0';
 257        return buf;
 258}
 259
 260/* Based on code by Douglas W. Jones found at
 261 * <http://www.cs.uiowa.edu/~jones/bcd/decimal.html#sixtyfour>
 262 * (with permission from the author).
 263 * Performs no 64-bit division and hence should be fast on 32-bit machines.
 264 */
 265static
 266char *put_dec(char *buf, unsigned long long n)
 267{
 268        uint32_t d3, d2, d1, q, h;
 269
 270        if (n < 100*1000*1000)
 271                return put_dec_trunc8(buf, n);
 272
 273        d1  = ((uint32_t)n >> 16); /* implicit "& 0xffff" */
 274        h   = (n >> 32);
 275        d2  = (h      ) & 0xffff;
 276        d3  = (h >> 16); /* implicit "& 0xffff" */
 277
 278        q   = 656 * d3 + 7296 * d2 + 5536 * d1 + ((uint32_t)n & 0xffff);
 279
 280        buf = put_dec_full4(buf, q % 10000);
 281        q   = q / 10000;
 282
 283        d1  = q + 7671 * d3 + 9496 * d2 + 6 * d1;
 284        buf = put_dec_full4(buf, d1 % 10000);
 285        q   = d1 / 10000;
 286
 287        d2  = q + 4749 * d3 + 42 * d2;
 288        buf = put_dec_full4(buf, d2 % 10000);
 289        q   = d2 / 10000;
 290
 291        d3  = q + 281 * d3;
 292        if (!d3)
 293                goto done;
 294        buf = put_dec_full4(buf, d3 % 10000);
 295        q   = d3 / 10000;
 296        if (!q)
 297                goto done;
 298        buf = put_dec_full4(buf, q);
 299 done:
 300        while (buf[-1] == '0')
 301                --buf;
 302
 303        return buf;
 304}
 305
 306#endif
 307
 308/*
 309 * Convert passed number to decimal string.
 310 * Returns the length of string.  On buffer overflow, returns 0.
 311 *
 312 * If speed is not important, use snprintf(). It's easy to read the code.
 313 */
 314int num_to_str(char *buf, int size, unsigned long long num)
 315{
 316        char tmp[sizeof(num) * 3];
 317        int idx, len;
 318
 319        /* put_dec() may work incorrectly for num = 0 (generate "", not "0") */
 320        if (num <= 9) {
 321                tmp[0] = '0' + num;
 322                len = 1;
 323        } else {
 324                len = put_dec(tmp, num) - tmp;
 325        }
 326
 327        if (len > size)
 328                return 0;
 329        for (idx = 0; idx < len; ++idx)
 330                buf[idx] = tmp[len - idx - 1];
 331        return len;
 332}
 333
 334#define ZEROPAD 1               /* pad with zero */
 335#define SIGN    2               /* unsigned/signed long */
 336#define PLUS    4               /* show plus */
 337#define SPACE   8               /* space if plus */
 338#define LEFT    16              /* left justified */
 339#define SMALL   32              /* use lowercase in hex (must be 32 == 0x20) */
 340#define SPECIAL 64              /* prefix hex with "0x", octal with "0" */
 341
 342enum format_type {
 343        FORMAT_TYPE_NONE, /* Just a string part */
 344        FORMAT_TYPE_WIDTH,
 345        FORMAT_TYPE_PRECISION,
 346        FORMAT_TYPE_CHAR,
 347        FORMAT_TYPE_STR,
 348        FORMAT_TYPE_PTR,
 349        FORMAT_TYPE_PERCENT_CHAR,
 350        FORMAT_TYPE_INVALID,
 351        FORMAT_TYPE_LONG_LONG,
 352        FORMAT_TYPE_ULONG,
 353        FORMAT_TYPE_LONG,
 354        FORMAT_TYPE_UBYTE,
 355        FORMAT_TYPE_BYTE,
 356        FORMAT_TYPE_USHORT,
 357        FORMAT_TYPE_SHORT,
 358        FORMAT_TYPE_UINT,
 359        FORMAT_TYPE_INT,
 360        FORMAT_TYPE_NRCHARS,
 361        FORMAT_TYPE_SIZE_T,
 362        FORMAT_TYPE_PTRDIFF
 363};
 364
 365struct printf_spec {
 366        u8      type;           /* format_type enum */
 367        u8      flags;          /* flags to number() */
 368        u8      base;           /* number base, 8, 10 or 16 only */
 369        u8      qualifier;      /* number qualifier, one of 'hHlLtzZ' */
 370        s16     field_width;    /* width of output field */
 371        s16     precision;      /* # of digits/chars */
 372};
 373
 374static noinline_for_stack
 375char *number(char *buf, char *end, unsigned long long num,
 376             struct printf_spec spec)
 377{
 378        /* we are called with base 8, 10 or 16, only, thus don't need "G..."  */
 379        static const char digits[16] = "0123456789ABCDEF"; /* "GHIJKLMNOPQRSTUVWXYZ"; */
 380
 381        char tmp[66];
 382        char sign;
 383        char locase;
 384        int need_pfx = ((spec.flags & SPECIAL) && spec.base != 10);
 385        int i;
 386        bool is_zero = num == 0LL;
 387
 388        /* locase = 0 or 0x20. ORing digits or letters with 'locase'
 389         * produces same digits or (maybe lowercased) letters */
 390        locase = (spec.flags & SMALL);
 391        if (spec.flags & LEFT)
 392                spec.flags &= ~ZEROPAD;
 393        sign = 0;
 394        if (spec.flags & SIGN) {
 395                if ((signed long long)num < 0) {
 396                        sign = '-';
 397                        num = -(signed long long)num;
 398                        spec.field_width--;
 399                } else if (spec.flags & PLUS) {
 400                        sign = '+';
 401                        spec.field_width--;
 402                } else if (spec.flags & SPACE) {
 403                        sign = ' ';
 404                        spec.field_width--;
 405                }
 406        }
 407        if (need_pfx) {
 408                if (spec.base == 16)
 409                        spec.field_width -= 2;
 410                else if (!is_zero)
 411                        spec.field_width--;
 412        }
 413
 414        /* generate full string in tmp[], in reverse order */
 415        i = 0;
 416        if (num < spec.base)
 417                tmp[i++] = digits[num] | locase;
 418        /* Generic code, for any base:
 419        else do {
 420                tmp[i++] = (digits[do_div(num,base)] | locase);
 421        } while (num != 0);
 422        */
 423        else if (spec.base != 10) { /* 8 or 16 */
 424                int mask = spec.base - 1;
 425                int shift = 3;
 426
 427                if (spec.base == 16)
 428                        shift = 4;
 429                do {
 430                        tmp[i++] = (digits[((unsigned char)num) & mask] | locase);
 431                        num >>= shift;
 432                } while (num);
 433        } else { /* base 10 */
 434                i = put_dec(tmp, num) - tmp;
 435        }
 436
 437        /* printing 100 using %2d gives "100", not "00" */
 438        if (i > spec.precision)
 439                spec.precision = i;
 440        /* leading space padding */
 441        spec.field_width -= spec.precision;
 442        if (!(spec.flags & (ZEROPAD+LEFT))) {
 443                while (--spec.field_width >= 0) {
 444                        if (buf < end)
 445                                *buf = ' ';
 446                        ++buf;
 447                }
 448        }
 449        /* sign */
 450        if (sign) {
 451                if (buf < end)
 452                        *buf = sign;
 453                ++buf;
 454        }
 455        /* "0x" / "0" prefix */
 456        if (need_pfx) {
 457                if (spec.base == 16 || !is_zero) {
 458                        if (buf < end)
 459                                *buf = '0';
 460                        ++buf;
 461                }
 462                if (spec.base == 16) {
 463                        if (buf < end)
 464                                *buf = ('X' | locase);
 465                        ++buf;
 466                }
 467        }
 468        /* zero or space padding */
 469        if (!(spec.flags & LEFT)) {
 470                char c = (spec.flags & ZEROPAD) ? '0' : ' ';
 471                while (--spec.field_width >= 0) {
 472                        if (buf < end)
 473                                *buf = c;
 474                        ++buf;
 475                }
 476        }
 477        /* hmm even more zero padding? */
 478        while (i <= --spec.precision) {
 479                if (buf < end)
 480                        *buf = '0';
 481                ++buf;
 482        }
 483        /* actual digits of result */
 484        while (--i >= 0) {
 485                if (buf < end)
 486                        *buf = tmp[i];
 487                ++buf;
 488        }
 489        /* trailing space padding */
 490        while (--spec.field_width >= 0) {
 491                if (buf < end)
 492                        *buf = ' ';
 493                ++buf;
 494        }
 495
 496        return buf;
 497}
 498
 499static noinline_for_stack
 500char *string(char *buf, char *end, const char *s, struct printf_spec spec)
 501{
 502        int len, i;
 503
 504        if ((unsigned long)s < PAGE_SIZE)
 505                s = "(null)";
 506
 507        len = strnlen(s, spec.precision);
 508
 509        if (!(spec.flags & LEFT)) {
 510                while (len < spec.field_width--) {
 511                        if (buf < end)
 512                                *buf = ' ';
 513                        ++buf;
 514                }
 515        }
 516        for (i = 0; i < len; ++i) {
 517                if (buf < end)
 518                        *buf = *s;
 519                ++buf; ++s;
 520        }
 521        while (len < spec.field_width--) {
 522                if (buf < end)
 523                        *buf = ' ';
 524                ++buf;
 525        }
 526
 527        return buf;
 528}
 529
 530static noinline_for_stack
 531char *symbol_string(char *buf, char *end, void *ptr,
 532                    struct printf_spec spec, char ext)
 533{
 534        unsigned long value = (unsigned long) ptr;
 535#ifdef CONFIG_KALLSYMS
 536        char sym[KSYM_SYMBOL_LEN];
 537        if (ext == 'B')
 538                sprint_backtrace(sym, value);
 539        else if (ext != 'f' && ext != 's')
 540                sprint_symbol(sym, value);
 541        else
 542                sprint_symbol_no_offset(sym, value);
 543
 544        return string(buf, end, sym, spec);
 545#else
 546        spec.field_width = 2 * sizeof(void *);
 547        spec.flags |= SPECIAL | SMALL | ZEROPAD;
 548        spec.base = 16;
 549
 550        return number(buf, end, value, spec);
 551#endif
 552}
 553
 554static noinline_for_stack
 555char *resource_string(char *buf, char *end, struct resource *res,
 556                      struct printf_spec spec, const char *fmt)
 557{
 558#ifndef IO_RSRC_PRINTK_SIZE
 559#define IO_RSRC_PRINTK_SIZE     6
 560#endif
 561
 562#ifndef MEM_RSRC_PRINTK_SIZE
 563#define MEM_RSRC_PRINTK_SIZE    10
 564#endif
 565        static const struct printf_spec io_spec = {
 566                .base = 16,
 567                .field_width = IO_RSRC_PRINTK_SIZE,
 568                .precision = -1,
 569                .flags = SPECIAL | SMALL | ZEROPAD,
 570        };
 571        static const struct printf_spec mem_spec = {
 572                .base = 16,
 573                .field_width = MEM_RSRC_PRINTK_SIZE,
 574                .precision = -1,
 575                .flags = SPECIAL | SMALL | ZEROPAD,
 576        };
 577        static const struct printf_spec bus_spec = {
 578                .base = 16,
 579                .field_width = 2,
 580                .precision = -1,
 581                .flags = SMALL | ZEROPAD,
 582        };
 583        static const struct printf_spec dec_spec = {
 584                .base = 10,
 585                .precision = -1,
 586                .flags = 0,
 587        };
 588        static const struct printf_spec str_spec = {
 589                .field_width = -1,
 590                .precision = 10,
 591                .flags = LEFT,
 592        };
 593        static const struct printf_spec flag_spec = {
 594                .base = 16,
 595                .precision = -1,
 596                .flags = SPECIAL | SMALL,
 597        };
 598
 599        /* 32-bit res (sizeof==4): 10 chars in dec, 10 in hex ("0x" + 8)
 600         * 64-bit res (sizeof==8): 20 chars in dec, 18 in hex ("0x" + 16) */
 601#define RSRC_BUF_SIZE           ((2 * sizeof(resource_size_t)) + 4)
 602#define FLAG_BUF_SIZE           (2 * sizeof(res->flags))
 603#define DECODED_BUF_SIZE        sizeof("[mem - 64bit pref window disabled]")
 604#define RAW_BUF_SIZE            sizeof("[mem - flags 0x]")
 605        char sym[max(2*RSRC_BUF_SIZE + DECODED_BUF_SIZE,
 606                     2*RSRC_BUF_SIZE + FLAG_BUF_SIZE + RAW_BUF_SIZE)];
 607
 608        char *p = sym, *pend = sym + sizeof(sym);
 609        int decode = (fmt[0] == 'R') ? 1 : 0;
 610        const struct printf_spec *specp;
 611
 612        *p++ = '[';
 613        if (res->flags & IORESOURCE_IO) {
 614                p = string(p, pend, "io  ", str_spec);
 615                specp = &io_spec;
 616        } else if (res->flags & IORESOURCE_MEM) {
 617                p = string(p, pend, "mem ", str_spec);
 618                specp = &mem_spec;
 619        } else if (res->flags & IORESOURCE_IRQ) {
 620                p = string(p, pend, "irq ", str_spec);
 621                specp = &dec_spec;
 622        } else if (res->flags & IORESOURCE_DMA) {
 623                p = string(p, pend, "dma ", str_spec);
 624                specp = &dec_spec;
 625        } else if (res->flags & IORESOURCE_BUS) {
 626                p = string(p, pend, "bus ", str_spec);
 627                specp = &bus_spec;
 628        } else {
 629                p = string(p, pend, "??? ", str_spec);
 630                specp = &mem_spec;
 631                decode = 0;
 632        }
 633        p = number(p, pend, res->start, *specp);
 634        if (res->start != res->end) {
 635                *p++ = '-';
 636                p = number(p, pend, res->end, *specp);
 637        }
 638        if (decode) {
 639                if (res->flags & IORESOURCE_MEM_64)
 640                        p = string(p, pend, " 64bit", str_spec);
 641                if (res->flags & IORESOURCE_PREFETCH)
 642                        p = string(p, pend, " pref", str_spec);
 643                if (res->flags & IORESOURCE_WINDOW)
 644                        p = string(p, pend, " window", str_spec);
 645                if (res->flags & IORESOURCE_DISABLED)
 646                        p = string(p, pend, " disabled", str_spec);
 647        } else {
 648                p = string(p, pend, " flags ", str_spec);
 649                p = number(p, pend, res->flags, flag_spec);
 650        }
 651        *p++ = ']';
 652        *p = '\0';
 653
 654        return string(buf, end, sym, spec);
 655}
 656
 657static noinline_for_stack
 658char *mac_address_string(char *buf, char *end, u8 *addr,
 659                         struct printf_spec spec, const char *fmt)
 660{
 661        char mac_addr[sizeof("xx:xx:xx:xx:xx:xx")];
 662        char *p = mac_addr;
 663        int i;
 664        char separator;
 665
 666        if (fmt[1] == 'F') {            /* FDDI canonical format */
 667                separator = '-';
 668        } else {
 669                separator = ':';
 670        }
 671
 672        for (i = 0; i < 6; i++) {
 673                p = hex_byte_pack(p, addr[i]);
 674                if (fmt[0] == 'M' && i != 5)
 675                        *p++ = separator;
 676        }
 677        *p = '\0';
 678
 679        return string(buf, end, mac_addr, spec);
 680}
 681
 682static noinline_for_stack
 683char *ip4_string(char *p, const u8 *addr, const char *fmt)
 684{
 685        int i;
 686        bool leading_zeros = (fmt[0] == 'i');
 687        int index;
 688        int step;
 689
 690        switch (fmt[2]) {
 691        case 'h':
 692#ifdef __BIG_ENDIAN
 693                index = 0;
 694                step = 1;
 695#else
 696                index = 3;
 697                step = -1;
 698#endif
 699                break;
 700        case 'l':
 701                index = 3;
 702                step = -1;
 703                break;
 704        case 'n':
 705        case 'b':
 706        default:
 707                index = 0;
 708                step = 1;
 709                break;
 710        }
 711        for (i = 0; i < 4; i++) {
 712                char temp[3];   /* hold each IP quad in reverse order */
 713                int digits = put_dec_trunc8(temp, addr[index]) - temp;
 714                if (leading_zeros) {
 715                        if (digits < 3)
 716                                *p++ = '0';
 717                        if (digits < 2)
 718                                *p++ = '0';
 719                }
 720                /* reverse the digits in the quad */
 721                while (digits--)
 722                        *p++ = temp[digits];
 723                if (i < 3)
 724                        *p++ = '.';
 725                index += step;
 726        }
 727        *p = '\0';
 728
 729        return p;
 730}
 731
 732static noinline_for_stack
 733char *ip6_compressed_string(char *p, const char *addr)
 734{
 735        int i, j, range;
 736        unsigned char zerolength[8];
 737        int longest = 1;
 738        int colonpos = -1;
 739        u16 word;
 740        u8 hi, lo;
 741        bool needcolon = false;
 742        bool useIPv4;
 743        struct in6_addr in6;
 744
 745        memcpy(&in6, addr, sizeof(struct in6_addr));
 746
 747        useIPv4 = ipv6_addr_v4mapped(&in6) || ipv6_addr_is_isatap(&in6);
 748
 749        memset(zerolength, 0, sizeof(zerolength));
 750
 751        if (useIPv4)
 752                range = 6;
 753        else
 754                range = 8;
 755
 756        /* find position of longest 0 run */
 757        for (i = 0; i < range; i++) {
 758                for (j = i; j < range; j++) {
 759                        if (in6.s6_addr16[j] != 0)
 760                                break;
 761                        zerolength[i]++;
 762                }
 763        }
 764        for (i = 0; i < range; i++) {
 765                if (zerolength[i] > longest) {
 766                        longest = zerolength[i];
 767                        colonpos = i;
 768                }
 769        }
 770        if (longest == 1)               /* don't compress a single 0 */
 771                colonpos = -1;
 772
 773        /* emit address */
 774        for (i = 0; i < range; i++) {
 775                if (i == colonpos) {
 776                        if (needcolon || i == 0)
 777                                *p++ = ':';
 778                        *p++ = ':';
 779                        needcolon = false;
 780                        i += longest - 1;
 781                        continue;
 782                }
 783                if (needcolon) {
 784                        *p++ = ':';
 785                        needcolon = false;
 786                }
 787                /* hex u16 without leading 0s */
 788                word = ntohs(in6.s6_addr16[i]);
 789                hi = word >> 8;
 790                lo = word & 0xff;
 791                if (hi) {
 792                        if (hi > 0x0f)
 793                                p = hex_byte_pack(p, hi);
 794                        else
 795                                *p++ = hex_asc_lo(hi);
 796                        p = hex_byte_pack(p, lo);
 797                }
 798                else if (lo > 0x0f)
 799                        p = hex_byte_pack(p, lo);
 800                else
 801                        *p++ = hex_asc_lo(lo);
 802                needcolon = true;
 803        }
 804
 805        if (useIPv4) {
 806                if (needcolon)
 807                        *p++ = ':';
 808                p = ip4_string(p, &in6.s6_addr[12], "I4");
 809        }
 810        *p = '\0';
 811
 812        return p;
 813}
 814
 815static noinline_for_stack
 816char *ip6_string(char *p, const char *addr, const char *fmt)
 817{
 818        int i;
 819
 820        for (i = 0; i < 8; i++) {
 821                p = hex_byte_pack(p, *addr++);
 822                p = hex_byte_pack(p, *addr++);
 823                if (fmt[0] == 'I' && i != 7)
 824                        *p++ = ':';
 825        }
 826        *p = '\0';
 827
 828        return p;
 829}
 830
 831static noinline_for_stack
 832char *ip6_addr_string(char *buf, char *end, const u8 *addr,
 833                      struct printf_spec spec, const char *fmt)
 834{
 835        char ip6_addr[sizeof("xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255")];
 836
 837        if (fmt[0] == 'I' && fmt[2] == 'c')
 838                ip6_compressed_string(ip6_addr, addr);
 839        else
 840                ip6_string(ip6_addr, addr, fmt);
 841
 842        return string(buf, end, ip6_addr, spec);
 843}
 844
 845static noinline_for_stack
 846char *ip4_addr_string(char *buf, char *end, const u8 *addr,
 847                      struct printf_spec spec, const char *fmt)
 848{
 849        char ip4_addr[sizeof("255.255.255.255")];
 850
 851        ip4_string(ip4_addr, addr, fmt);
 852
 853        return string(buf, end, ip4_addr, spec);
 854}
 855
 856static noinline_for_stack
 857char *uuid_string(char *buf, char *end, const u8 *addr,
 858                  struct printf_spec spec, const char *fmt)
 859{
 860        char uuid[sizeof("xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx")];
 861        char *p = uuid;
 862        int i;
 863        static const u8 be[16] = {0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15};
 864        static const u8 le[16] = {3,2,1,0,5,4,7,6,8,9,10,11,12,13,14,15};
 865        const u8 *index = be;
 866        bool uc = false;
 867
 868        switch (*(++fmt)) {
 869        case 'L':
 870                uc = true;              /* fall-through */
 871        case 'l':
 872                index = le;
 873                break;
 874        case 'B':
 875                uc = true;
 876                break;
 877        }
 878
 879        for (i = 0; i < 16; i++) {
 880                p = hex_byte_pack(p, addr[index[i]]);
 881                switch (i) {
 882                case 3:
 883                case 5:
 884                case 7:
 885                case 9:
 886                        *p++ = '-';
 887                        break;
 888                }
 889        }
 890
 891        *p = 0;
 892
 893        if (uc) {
 894                p = uuid;
 895                do {
 896                        *p = toupper(*p);
 897                } while (*(++p));
 898        }
 899
 900        return string(buf, end, uuid, spec);
 901}
 902
 903static
 904char *netdev_feature_string(char *buf, char *end, const u8 *addr,
 905                      struct printf_spec spec)
 906{
 907        spec.flags |= SPECIAL | SMALL | ZEROPAD;
 908        if (spec.field_width == -1)
 909                spec.field_width = 2 + 2 * sizeof(netdev_features_t);
 910        spec.base = 16;
 911
 912        return number(buf, end, *(const netdev_features_t *)addr, spec);
 913}
 914
 915int kptr_restrict __read_mostly;
 916
 917/*
 918 * Show a '%p' thing.  A kernel extension is that the '%p' is followed
 919 * by an extra set of alphanumeric characters that are extended format
 920 * specifiers.
 921 *
 922 * Right now we handle:
 923 *
 924 * - 'F' For symbolic function descriptor pointers with offset
 925 * - 'f' For simple symbolic function names without offset
 926 * - 'S' For symbolic direct pointers with offset
 927 * - 's' For symbolic direct pointers without offset
 928 * - 'B' For backtraced symbolic direct pointers with offset
 929 * - 'R' For decoded struct resource, e.g., [mem 0x0-0x1f 64bit pref]
 930 * - 'r' For raw struct resource, e.g., [mem 0x0-0x1f flags 0x201]
 931 * - 'M' For a 6-byte MAC address, it prints the address in the
 932 *       usual colon-separated hex notation
 933 * - 'm' For a 6-byte MAC address, it prints the hex address without colons
 934 * - 'MF' For a 6-byte MAC FDDI address, it prints the address
 935 *       with a dash-separated hex notation
 936 * - 'I' [46] for IPv4/IPv6 addresses printed in the usual way
 937 *       IPv4 uses dot-separated decimal without leading 0's (1.2.3.4)
 938 *       IPv6 uses colon separated network-order 16 bit hex with leading 0's
 939 * - 'i' [46] for 'raw' IPv4/IPv6 addresses
 940 *       IPv6 omits the colons (01020304...0f)
 941 *       IPv4 uses dot-separated decimal with leading 0's (010.123.045.006)
 942 * - '[Ii]4[hnbl]' IPv4 addresses in host, network, big or little endian order
 943 * - 'I6c' for IPv6 addresses printed as specified by
 944 *       http://tools.ietf.org/html/rfc5952
 945 * - 'U' For a 16 byte UUID/GUID, it prints the UUID/GUID in the form
 946 *       "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx"
 947 *       Options for %pU are:
 948 *         b big endian lower case hex (default)
 949 *         B big endian UPPER case hex
 950 *         l little endian lower case hex
 951 *         L little endian UPPER case hex
 952 *           big endian output byte order is:
 953 *             [0][1][2][3]-[4][5]-[6][7]-[8][9]-[10][11][12][13][14][15]
 954 *           little endian output byte order is:
 955 *             [3][2][1][0]-[5][4]-[7][6]-[8][9]-[10][11][12][13][14][15]
 956 * - 'V' For a struct va_format which contains a format string * and va_list *,
 957 *       call vsnprintf(->format, *->va_list).
 958 *       Implements a "recursive vsnprintf".
 959 *       Do not use this feature without some mechanism to verify the
 960 *       correctness of the format string and va_list arguments.
 961 * - 'K' For a kernel pointer that should be hidden from unprivileged users
 962 * - 'NF' For a netdev_features_t
 963 *
 964 * Note: The difference between 'S' and 'F' is that on ia64 and ppc64
 965 * function pointers are really function descriptors, which contain a
 966 * pointer to the real address.
 967 */
 968static noinline_for_stack
 969char *pointer(const char *fmt, char *buf, char *end, void *ptr,
 970              struct printf_spec spec)
 971{
 972        int default_width = 2 * sizeof(void *) + (spec.flags & SPECIAL ? 2 : 0);
 973
 974        if (!ptr && *fmt != 'K') {
 975                /*
 976                 * Print (null) with the same width as a pointer so it makes
 977                 * tabular output look nice.
 978                 */
 979                if (spec.field_width == -1)
 980                        spec.field_width = default_width;
 981                return string(buf, end, "(null)", spec);
 982        }
 983
 984        switch (*fmt) {
 985        case 'F':
 986        case 'f':
 987                ptr = dereference_function_descriptor(ptr);
 988                /* Fallthrough */
 989        case 'S':
 990        case 's':
 991        case 'B':
 992                return symbol_string(buf, end, ptr, spec, *fmt);
 993        case 'R':
 994        case 'r':
 995                return resource_string(buf, end, ptr, spec, fmt);
 996        case 'M':                       /* Colon separated: 00:01:02:03:04:05 */
 997        case 'm':                       /* Contiguous: 000102030405 */
 998                                        /* [mM]F (FDDI, bit reversed) */
 999                return mac_address_string(buf, end, ptr, spec, fmt);
1000        case 'I':                       /* Formatted IP supported
1001                                         * 4:   1.2.3.4
1002                                         * 6:   0001:0203:...:0708
1003                                         * 6c:  1::708 or 1::1.2.3.4
1004                                         */
1005        case 'i':                       /* Contiguous:
1006                                         * 4:   001.002.003.004
1007                                         * 6:   000102...0f
1008                                         */
1009                switch (fmt[1]) {
1010                case '6':
1011                        return ip6_addr_string(buf, end, ptr, spec, fmt);
1012                case '4':
1013                        return ip4_addr_string(buf, end, ptr, spec, fmt);
1014                }
1015                break;
1016        case 'U':
1017                return uuid_string(buf, end, ptr, spec, fmt);
1018        case 'V':
1019                {
1020                        va_list va;
1021
1022                        va_copy(va, *((struct va_format *)ptr)->va);
1023                        buf += vsnprintf(buf, end > buf ? end - buf : 0,
1024                                         ((struct va_format *)ptr)->fmt, va);
1025                        va_end(va);
1026                        return buf;
1027                }
1028        case 'K':
1029                /*
1030                 * %pK cannot be used in IRQ context because its test
1031                 * for CAP_SYSLOG would be meaningless.
1032                 */
1033                if (kptr_restrict && (in_irq() || in_serving_softirq() ||
1034                                      in_nmi())) {
1035                        if (spec.field_width == -1)
1036                                spec.field_width = default_width;
1037                        return string(buf, end, "pK-error", spec);
1038                }
1039                if (!((kptr_restrict == 0) ||
1040                      (kptr_restrict == 1 &&
1041                       has_capability_noaudit(current, CAP_SYSLOG))))
1042                        ptr = NULL;
1043                break;
1044        case 'N':
1045                switch (fmt[1]) {
1046                case 'F':
1047                        return netdev_feature_string(buf, end, ptr, spec);
1048                }
1049                break;
1050        }
1051        spec.flags |= SMALL;
1052        if (spec.field_width == -1) {
1053                spec.field_width = default_width;
1054                spec.flags |= ZEROPAD;
1055        }
1056        spec.base = 16;
1057
1058        return number(buf, end, (unsigned long) ptr, spec);
1059}
1060
1061/*
1062 * Helper function to decode printf style format.
1063 * Each call decode a token from the format and return the
1064 * number of characters read (or likely the delta where it wants
1065 * to go on the next call).
1066 * The decoded token is returned through the parameters
1067 *
1068 * 'h', 'l', or 'L' for integer fields
1069 * 'z' support added 23/7/1999 S.H.
1070 * 'z' changed to 'Z' --davidm 1/25/99
1071 * 't' added for ptrdiff_t
1072 *
1073 * @fmt: the format string
1074 * @type of the token returned
1075 * @flags: various flags such as +, -, # tokens..
1076 * @field_width: overwritten width
1077 * @base: base of the number (octal, hex, ...)
1078 * @precision: precision of a number
1079 * @qualifier: qualifier of a number (long, size_t, ...)
1080 */
1081static noinline_for_stack
1082int format_decode(const char *fmt, struct printf_spec *spec)
1083{
1084        const char *start = fmt;
1085
1086        /* we finished early by reading the field width */
1087        if (spec->type == FORMAT_TYPE_WIDTH) {
1088                if (spec->field_width < 0) {
1089                        spec->field_width = -spec->field_width;
1090                        spec->flags |= LEFT;
1091                }
1092                spec->type = FORMAT_TYPE_NONE;
1093                goto precision;
1094        }
1095
1096        /* we finished early by reading the precision */
1097        if (spec->type == FORMAT_TYPE_PRECISION) {
1098                if (spec->precision < 0)
1099                        spec->precision = 0;
1100
1101                spec->type = FORMAT_TYPE_NONE;
1102                goto qualifier;
1103        }
1104
1105        /* By default */
1106        spec->type = FORMAT_TYPE_NONE;
1107
1108        for (; *fmt ; ++fmt) {
1109                if (*fmt == '%')
1110                        break;
1111        }
1112
1113        /* Return the current non-format string */
1114        if (fmt != start || !*fmt)
1115                return fmt - start;
1116
1117        /* Process flags */
1118        spec->flags = 0;
1119
1120        while (1) { /* this also skips first '%' */
1121                bool found = true;
1122
1123                ++fmt;
1124
1125                switch (*fmt) {
1126                case '-': spec->flags |= LEFT;    break;
1127                case '+': spec->flags |= PLUS;    break;
1128                case ' ': spec->flags |= SPACE;   break;
1129                case '#': spec->flags |= SPECIAL; break;
1130                case '0': spec->flags |= ZEROPAD; break;
1131                default:  found = false;
1132                }
1133
1134                if (!found)
1135                        break;
1136        }
1137
1138        /* get field width */
1139        spec->field_width = -1;
1140
1141        if (isdigit(*fmt))
1142                spec->field_width = skip_atoi(&fmt);
1143        else if (*fmt == '*') {
1144                /* it's the next argument */
1145                spec->type = FORMAT_TYPE_WIDTH;
1146                return ++fmt - start;
1147        }
1148
1149precision:
1150        /* get the precision */
1151        spec->precision = -1;
1152        if (*fmt == '.') {
1153                ++fmt;
1154                if (isdigit(*fmt)) {
1155                        spec->precision = skip_atoi(&fmt);
1156                        if (spec->precision < 0)
1157                                spec->precision = 0;
1158                } else if (*fmt == '*') {
1159                        /* it's the next argument */
1160                        spec->type = FORMAT_TYPE_PRECISION;
1161                        return ++fmt - start;
1162                }
1163        }
1164
1165qualifier:
1166        /* get the conversion qualifier */
1167        spec->qualifier = -1;
1168        if (*fmt == 'h' || _tolower(*fmt) == 'l' ||
1169            _tolower(*fmt) == 'z' || *fmt == 't') {
1170                spec->qualifier = *fmt++;
1171                if (unlikely(spec->qualifier == *fmt)) {
1172                        if (spec->qualifier == 'l') {
1173                                spec->qualifier = 'L';
1174                                ++fmt;
1175                        } else if (spec->qualifier == 'h') {
1176                                spec->qualifier = 'H';
1177                                ++fmt;
1178                        }
1179                }
1180        }
1181
1182        /* default base */
1183        spec->base = 10;
1184        switch (*fmt) {
1185        case 'c':
1186                spec->type = FORMAT_TYPE_CHAR;
1187                return ++fmt - start;
1188
1189        case 's':
1190                spec->type = FORMAT_TYPE_STR;
1191                return ++fmt - start;
1192
1193        case 'p':
1194                spec->type = FORMAT_TYPE_PTR;
1195                return fmt - start;
1196                /* skip alnum */
1197
1198        case 'n':
1199                spec->type = FORMAT_TYPE_NRCHARS;
1200                return ++fmt - start;
1201
1202        case '%':
1203                spec->type = FORMAT_TYPE_PERCENT_CHAR;
1204                return ++fmt - start;
1205
1206        /* integer number formats - set up the flags and "break" */
1207        case 'o':
1208                spec->base = 8;
1209                break;
1210
1211        case 'x':
1212                spec->flags |= SMALL;
1213
1214        case 'X':
1215                spec->base = 16;
1216                break;
1217
1218        case 'd':
1219        case 'i':
1220                spec->flags |= SIGN;
1221        case 'u':
1222                break;
1223
1224        default:
1225                spec->type = FORMAT_TYPE_INVALID;
1226                return fmt - start;
1227        }
1228
1229        if (spec->qualifier == 'L')
1230                spec->type = FORMAT_TYPE_LONG_LONG;
1231        else if (spec->qualifier == 'l') {
1232                if (spec->flags & SIGN)
1233                        spec->type = FORMAT_TYPE_LONG;
1234                else
1235                        spec->type = FORMAT_TYPE_ULONG;
1236        } else if (_tolower(spec->qualifier) == 'z') {
1237                spec->type = FORMAT_TYPE_SIZE_T;
1238        } else if (spec->qualifier == 't') {
1239                spec->type = FORMAT_TYPE_PTRDIFF;
1240        } else if (spec->qualifier == 'H') {
1241                if (spec->flags & SIGN)
1242                        spec->type = FORMAT_TYPE_BYTE;
1243                else
1244                        spec->type = FORMAT_TYPE_UBYTE;
1245        } else if (spec->qualifier == 'h') {
1246                if (spec->flags & SIGN)
1247                        spec->type = FORMAT_TYPE_SHORT;
1248                else
1249                        spec->type = FORMAT_TYPE_USHORT;
1250        } else {
1251                if (spec->flags & SIGN)
1252                        spec->type = FORMAT_TYPE_INT;
1253                else
1254                        spec->type = FORMAT_TYPE_UINT;
1255        }
1256
1257        return ++fmt - start;
1258}
1259
1260/**
1261 * vsnprintf - Format a string and place it in a buffer
1262 * @buf: The buffer to place the result into
1263 * @size: The size of the buffer, including the trailing null space
1264 * @fmt: The format string to use
1265 * @args: Arguments for the format string
1266 *
1267 * This function follows C99 vsnprintf, but has some extensions:
1268 * %pS output the name of a text symbol with offset
1269 * %ps output the name of a text symbol without offset
1270 * %pF output the name of a function pointer with its offset
1271 * %pf output the name of a function pointer without its offset
1272 * %pB output the name of a backtrace symbol with its offset
1273 * %pR output the address range in a struct resource with decoded flags
1274 * %pr output the address range in a struct resource with raw flags
1275 * %pM output a 6-byte MAC address with colons
1276 * %pm output a 6-byte MAC address without colons
1277 * %pI4 print an IPv4 address without leading zeros
1278 * %pi4 print an IPv4 address with leading zeros
1279 * %pI6 print an IPv6 address with colons
1280 * %pi6 print an IPv6 address without colons
1281 * %pI6c print an IPv6 address as specified by RFC 5952
1282 * %pU[bBlL] print a UUID/GUID in big or little endian using lower or upper
1283 *   case.
1284 * %n is ignored
1285 *
1286 * The return value is the number of characters which would
1287 * be generated for the given input, excluding the trailing
1288 * '\0', as per ISO C99. If you want to have the exact
1289 * number of characters written into @buf as return value
1290 * (not including the trailing '\0'), use vscnprintf(). If the
1291 * return is greater than or equal to @size, the resulting
1292 * string is truncated.
1293 *
1294 * If you're not already dealing with a va_list consider using snprintf().
1295 */
1296int vsnprintf(char *buf, size_t size, const char *fmt, va_list args)
1297{
1298        unsigned long long num;
1299        char *str, *end;
1300        struct printf_spec spec = {0};
1301
1302        /* Reject out-of-range values early.  Large positive sizes are
1303           used for unknown buffer sizes. */
1304        if (WARN_ON_ONCE((int) size < 0))
1305                return 0;
1306
1307        str = buf;
1308        end = buf + size;
1309
1310        /* Make sure end is always >= buf */
1311        if (end < buf) {
1312                end = ((void *)-1);
1313                size = end - buf;
1314        }
1315
1316        while (*fmt) {
1317                const char *old_fmt = fmt;
1318                int read = format_decode(fmt, &spec);
1319
1320                fmt += read;
1321
1322                switch (spec.type) {
1323                case FORMAT_TYPE_NONE: {
1324                        int copy = read;
1325                        if (str < end) {
1326                                if (copy > end - str)
1327                                        copy = end - str;
1328                                memcpy(str, old_fmt, copy);
1329                        }
1330                        str += read;
1331                        break;
1332                }
1333
1334                case FORMAT_TYPE_WIDTH:
1335                        spec.field_width = va_arg(args, int);
1336                        break;
1337
1338                case FORMAT_TYPE_PRECISION:
1339                        spec.precision = va_arg(args, int);
1340                        break;
1341
1342                case FORMAT_TYPE_CHAR: {
1343                        char c;
1344
1345                        if (!(spec.flags & LEFT)) {
1346                                while (--spec.field_width > 0) {
1347                                        if (str < end)
1348                                                *str = ' ';
1349                                        ++str;
1350
1351                                }
1352                        }
1353                        c = (unsigned char) va_arg(args, int);
1354                        if (str < end)
1355                                *str = c;
1356                        ++str;
1357                        while (--spec.field_width > 0) {
1358                                if (str < end)
1359                                        *str = ' ';
1360                                ++str;
1361                        }
1362                        break;
1363                }
1364
1365                case FORMAT_TYPE_STR:
1366                        str = string(str, end, va_arg(args, char *), spec);
1367                        break;
1368
1369                case FORMAT_TYPE_PTR:
1370                        str = pointer(fmt+1, str, end, va_arg(args, void *),
1371                                      spec);
1372                        while (isalnum(*fmt))
1373                                fmt++;
1374                        break;
1375
1376                case FORMAT_TYPE_PERCENT_CHAR:
1377                        if (str < end)
1378                                *str = '%';
1379                        ++str;
1380                        break;
1381
1382                case FORMAT_TYPE_INVALID:
1383                        if (str < end)
1384                                *str = '%';
1385                        ++str;
1386                        break;
1387
1388                case FORMAT_TYPE_NRCHARS: {
1389                        u8 qualifier = spec.qualifier;
1390
1391                        if (qualifier == 'l') {
1392                                long *ip = va_arg(args, long *);
1393                                *ip = (str - buf);
1394                        } else if (_tolower(qualifier) == 'z') {
1395                                size_t *ip = va_arg(args, size_t *);
1396                                *ip = (str - buf);
1397                        } else {
1398                                int *ip = va_arg(args, int *);
1399                                *ip = (str - buf);
1400                        }
1401                        break;
1402                }
1403
1404                default:
1405                        switch (spec.type) {
1406                        case FORMAT_TYPE_LONG_LONG:
1407                                num = va_arg(args, long long);
1408                                break;
1409                        case FORMAT_TYPE_ULONG:
1410                                num = va_arg(args, unsigned long);
1411                                break;
1412                        case FORMAT_TYPE_LONG:
1413                                num = va_arg(args, long);
1414                                break;
1415                        case FORMAT_TYPE_SIZE_T:
1416                                num = va_arg(args, size_t);
1417                                break;
1418                        case FORMAT_TYPE_PTRDIFF:
1419                                num = va_arg(args, ptrdiff_t);
1420                                break;
1421                        case FORMAT_TYPE_UBYTE:
1422                                num = (unsigned char) va_arg(args, int);
1423                                break;
1424                        case FORMAT_TYPE_BYTE:
1425                                num = (signed char) va_arg(args, int);
1426                                break;
1427                        case FORMAT_TYPE_USHORT:
1428                                num = (unsigned short) va_arg(args, int);
1429                                break;
1430                        case FORMAT_TYPE_SHORT:
1431                                num = (short) va_arg(args, int);
1432                                break;
1433                        case FORMAT_TYPE_INT:
1434                                num = (int) va_arg(args, int);
1435                                break;
1436                        default:
1437                                num = va_arg(args, unsigned int);
1438                        }
1439
1440                        str = number(str, end, num, spec);
1441                }
1442        }
1443
1444        if (size > 0) {
1445                if (str < end)
1446                        *str = '\0';
1447                else
1448                        end[-1] = '\0';
1449        }
1450
1451        /* the trailing null byte doesn't count towards the total */
1452        return str-buf;
1453
1454}
1455EXPORT_SYMBOL(vsnprintf);
1456
1457/**
1458 * vscnprintf - Format a string and place it in a buffer
1459 * @buf: The buffer to place the result into
1460 * @size: The size of the buffer, including the trailing null space
1461 * @fmt: The format string to use
1462 * @args: Arguments for the format string
1463 *
1464 * The return value is the number of characters which have been written into
1465 * the @buf not including the trailing '\0'. If @size is == 0 the function
1466 * returns 0.
1467 *
1468 * If you're not already dealing with a va_list consider using scnprintf().
1469 *
1470 * See the vsnprintf() documentation for format string extensions over C99.
1471 */
1472int vscnprintf(char *buf, size_t size, const char *fmt, va_list args)
1473{
1474        int i;
1475
1476        i = vsnprintf(buf, size, fmt, args);
1477
1478        if (likely(i < size))
1479                return i;
1480        if (size != 0)
1481                return size - 1;
1482        return 0;
1483}
1484EXPORT_SYMBOL(vscnprintf);
1485
1486/**
1487 * snprintf - Format a string and place it in a buffer
1488 * @buf: The buffer to place the result into
1489 * @size: The size of the buffer, including the trailing null space
1490 * @fmt: The format string to use
1491 * @...: Arguments for the format string
1492 *
1493 * The return value is the number of characters which would be
1494 * generated for the given input, excluding the trailing null,
1495 * as per ISO C99.  If the return is greater than or equal to
1496 * @size, the resulting string is truncated.
1497 *
1498 * See the vsnprintf() documentation for format string extensions over C99.
1499 */
1500int snprintf(char *buf, size_t size, const char *fmt, ...)
1501{
1502        va_list args;
1503        int i;
1504
1505        va_start(args, fmt);
1506        i = vsnprintf(buf, size, fmt, args);
1507        va_end(args);
1508
1509        return i;
1510}
1511EXPORT_SYMBOL(snprintf);
1512
1513/**
1514 * scnprintf - Format a string and place it in a buffer
1515 * @buf: The buffer to place the result into
1516 * @size: The size of the buffer, including the trailing null space
1517 * @fmt: The format string to use
1518 * @...: Arguments for the format string
1519 *
1520 * The return value is the number of characters written into @buf not including
1521 * the trailing '\0'. If @size is == 0 the function returns 0.
1522 */
1523
1524int scnprintf(char *buf, size_t size, const char *fmt, ...)
1525{
1526        va_list args;
1527        int i;
1528
1529        va_start(args, fmt);
1530        i = vscnprintf(buf, size, fmt, args);
1531        va_end(args);
1532
1533        return i;
1534}
1535EXPORT_SYMBOL(scnprintf);
1536
1537/**
1538 * vsprintf - Format a string and place it in a buffer
1539 * @buf: The buffer to place the result into
1540 * @fmt: The format string to use
1541 * @args: Arguments for the format string
1542 *
1543 * The function returns the number of characters written
1544 * into @buf. Use vsnprintf() or vscnprintf() in order to avoid
1545 * buffer overflows.
1546 *
1547 * If you're not already dealing with a va_list consider using sprintf().
1548 *
1549 * See the vsnprintf() documentation for format string extensions over C99.
1550 */
1551int vsprintf(char *buf, const char *fmt, va_list args)
1552{
1553        return vsnprintf(buf, INT_MAX, fmt, args);
1554}
1555EXPORT_SYMBOL(vsprintf);
1556
1557/**
1558 * sprintf - Format a string and place it in a buffer
1559 * @buf: The buffer to place the result into
1560 * @fmt: The format string to use
1561 * @...: Arguments for the format string
1562 *
1563 * The function returns the number of characters written
1564 * into @buf. Use snprintf() or scnprintf() in order to avoid
1565 * buffer overflows.
1566 *
1567 * See the vsnprintf() documentation for format string extensions over C99.
1568 */
1569int sprintf(char *buf, const char *fmt, ...)
1570{
1571        va_list args;
1572        int i;
1573
1574        va_start(args, fmt);
1575        i = vsnprintf(buf, INT_MAX, fmt, args);
1576        va_end(args);
1577
1578        return i;
1579}
1580EXPORT_SYMBOL(sprintf);
1581
1582#ifdef CONFIG_BINARY_PRINTF
1583/*
1584 * bprintf service:
1585 * vbin_printf() - VA arguments to binary data
1586 * bstr_printf() - Binary data to text string
1587 */
1588
1589/**
1590 * vbin_printf - Parse a format string and place args' binary value in a buffer
1591 * @bin_buf: The buffer to place args' binary value
1592 * @size: The size of the buffer(by words(32bits), not characters)
1593 * @fmt: The format string to use
1594 * @args: Arguments for the format string
1595 *
1596 * The format follows C99 vsnprintf, except %n is ignored, and its argument
1597 * is skiped.
1598 *
1599 * The return value is the number of words(32bits) which would be generated for
1600 * the given input.
1601 *
1602 * NOTE:
1603 * If the return value is greater than @size, the resulting bin_buf is NOT
1604 * valid for bstr_printf().
1605 */
1606int vbin_printf(u32 *bin_buf, size_t size, const char *fmt, va_list args)
1607{
1608        struct printf_spec spec = {0};
1609        char *str, *end;
1610
1611        str = (char *)bin_buf;
1612        end = (char *)(bin_buf + size);
1613
1614#define save_arg(type)                                                  \
1615do {                                                                    \
1616        if (sizeof(type) == 8) {                                        \
1617                unsigned long long value;                               \
1618                str = PTR_ALIGN(str, sizeof(u32));                      \
1619                value = va_arg(args, unsigned long long);               \
1620                if (str + sizeof(type) <= end) {                        \
1621                        *(u32 *)str = *(u32 *)&value;                   \
1622                        *(u32 *)(str + 4) = *((u32 *)&value + 1);       \
1623                }                                                       \
1624        } else {                                                        \
1625                unsigned long value;                                    \
1626                str = PTR_ALIGN(str, sizeof(type));                     \
1627                value = va_arg(args, int);                              \
1628                if (str + sizeof(type) <= end)                          \
1629                        *(typeof(type) *)str = (type)value;             \
1630        }                                                               \
1631        str += sizeof(type);                                            \
1632} while (0)
1633
1634        while (*fmt) {
1635                int read = format_decode(fmt, &spec);
1636
1637                fmt += read;
1638
1639                switch (spec.type) {
1640                case FORMAT_TYPE_NONE:
1641                case FORMAT_TYPE_INVALID:
1642                case FORMAT_TYPE_PERCENT_CHAR:
1643                        break;
1644
1645                case FORMAT_TYPE_WIDTH:
1646                case FORMAT_TYPE_PRECISION:
1647                        save_arg(int);
1648                        break;
1649
1650                case FORMAT_TYPE_CHAR:
1651                        save_arg(char);
1652                        break;
1653
1654                case FORMAT_TYPE_STR: {
1655                        const char *save_str = va_arg(args, char *);
1656                        size_t len;
1657
1658                        if ((unsigned long)save_str > (unsigned long)-PAGE_SIZE
1659                                        || (unsigned long)save_str < PAGE_SIZE)
1660                                save_str = "(null)";
1661                        len = strlen(save_str) + 1;
1662                        if (str + len < end)
1663                                memcpy(str, save_str, len);
1664                        str += len;
1665                        break;
1666                }
1667
1668                case FORMAT_TYPE_PTR:
1669                        save_arg(void *);
1670                        /* skip all alphanumeric pointer suffixes */
1671                        while (isalnum(*fmt))
1672                                fmt++;
1673                        break;
1674
1675                case FORMAT_TYPE_NRCHARS: {
1676                        /* skip %n 's argument */
1677                        u8 qualifier = spec.qualifier;
1678                        void *skip_arg;
1679                        if (qualifier == 'l')
1680                                skip_arg = va_arg(args, long *);
1681                        else if (_tolower(qualifier) == 'z')
1682                                skip_arg = va_arg(args, size_t *);
1683                        else
1684                                skip_arg = va_arg(args, int *);
1685                        break;
1686                }
1687
1688                default:
1689                        switch (spec.type) {
1690
1691                        case FORMAT_TYPE_LONG_LONG:
1692                                save_arg(long long);
1693                                break;
1694                        case FORMAT_TYPE_ULONG:
1695                        case FORMAT_TYPE_LONG:
1696                                save_arg(unsigned long);
1697                                break;
1698                        case FORMAT_TYPE_SIZE_T:
1699                                save_arg(size_t);
1700                                break;
1701                        case FORMAT_TYPE_PTRDIFF:
1702                                save_arg(ptrdiff_t);
1703                                break;
1704                        case FORMAT_TYPE_UBYTE:
1705                        case FORMAT_TYPE_BYTE:
1706                                save_arg(char);
1707                                break;
1708                        case FORMAT_TYPE_USHORT:
1709                        case FORMAT_TYPE_SHORT:
1710                                save_arg(short);
1711                                break;
1712                        default:
1713                                save_arg(int);
1714                        }
1715                }
1716        }
1717
1718        return (u32 *)(PTR_ALIGN(str, sizeof(u32))) - bin_buf;
1719#undef save_arg
1720}
1721EXPORT_SYMBOL_GPL(vbin_printf);
1722
1723/**
1724 * bstr_printf - Format a string from binary arguments and place it in a buffer
1725 * @buf: The buffer to place the result into
1726 * @size: The size of the buffer, including the trailing null space
1727 * @fmt: The format string to use
1728 * @bin_buf: Binary arguments for the format string
1729 *
1730 * This function like C99 vsnprintf, but the difference is that vsnprintf gets
1731 * arguments from stack, and bstr_printf gets arguments from @bin_buf which is
1732 * a binary buffer that generated by vbin_printf.
1733 *
1734 * The format follows C99 vsnprintf, but has some extensions:
1735 *  see vsnprintf comment for details.
1736 *
1737 * The return value is the number of characters which would
1738 * be generated for the given input, excluding the trailing
1739 * '\0', as per ISO C99. If you want to have the exact
1740 * number of characters written into @buf as return value
1741 * (not including the trailing '\0'), use vscnprintf(). If the
1742 * return is greater than or equal to @size, the resulting
1743 * string is truncated.
1744 */
1745int bstr_printf(char *buf, size_t size, const char *fmt, const u32 *bin_buf)
1746{
1747        struct printf_spec spec = {0};
1748        char *str, *end;
1749        const char *args = (const char *)bin_buf;
1750
1751        if (WARN_ON_ONCE((int) size < 0))
1752                return 0;
1753
1754        str = buf;
1755        end = buf + size;
1756
1757#define get_arg(type)                                                   \
1758({                                                                      \
1759        typeof(type) value;                                             \
1760        if (sizeof(type) == 8) {                                        \
1761                args = PTR_ALIGN(args, sizeof(u32));                    \
1762                *(u32 *)&value = *(u32 *)args;                          \
1763                *((u32 *)&value + 1) = *(u32 *)(args + 4);              \
1764        } else {                                                        \
1765                args = PTR_ALIGN(args, sizeof(type));                   \
1766                value = *(typeof(type) *)args;                          \
1767        }                                                               \
1768        args += sizeof(type);                                           \
1769        value;                                                          \
1770})
1771
1772        /* Make sure end is always >= buf */
1773        if (end < buf) {
1774                end = ((void *)-1);
1775                size = end - buf;
1776        }
1777
1778        while (*fmt) {
1779                const char *old_fmt = fmt;
1780                int read = format_decode(fmt, &spec);
1781
1782                fmt += read;
1783
1784                switch (spec.type) {
1785                case FORMAT_TYPE_NONE: {
1786                        int copy = read;
1787                        if (str < end) {
1788                                if (copy > end - str)
1789                                        copy = end - str;
1790                                memcpy(str, old_fmt, copy);
1791                        }
1792                        str += read;
1793                        break;
1794                }
1795
1796                case FORMAT_TYPE_WIDTH:
1797                        spec.field_width = get_arg(int);
1798                        break;
1799
1800                case FORMAT_TYPE_PRECISION:
1801                        spec.precision = get_arg(int);
1802                        break;
1803
1804                case FORMAT_TYPE_CHAR: {
1805                        char c;
1806
1807                        if (!(spec.flags & LEFT)) {
1808                                while (--spec.field_width > 0) {
1809                                        if (str < end)
1810                                                *str = ' ';
1811                                        ++str;
1812                                }
1813                        }
1814                        c = (unsigned char) get_arg(char);
1815                        if (str < end)
1816                                *str = c;
1817                        ++str;
1818                        while (--spec.field_width > 0) {
1819                                if (str < end)
1820                                        *str = ' ';
1821                                ++str;
1822                        }
1823                        break;
1824                }
1825
1826                case FORMAT_TYPE_STR: {
1827                        const char *str_arg = args;
1828                        args += strlen(str_arg) + 1;
1829                        str = string(str, end, (char *)str_arg, spec);
1830                        break;
1831                }
1832
1833                case FORMAT_TYPE_PTR:
1834                        str = pointer(fmt+1, str, end, get_arg(void *), spec);
1835                        while (isalnum(*fmt))
1836                                fmt++;
1837                        break;
1838
1839                case FORMAT_TYPE_PERCENT_CHAR:
1840                case FORMAT_TYPE_INVALID:
1841                        if (str < end)
1842                                *str = '%';
1843                        ++str;
1844                        break;
1845
1846                case FORMAT_TYPE_NRCHARS:
1847                        /* skip */
1848                        break;
1849
1850                default: {
1851                        unsigned long long num;
1852
1853                        switch (spec.type) {
1854
1855                        case FORMAT_TYPE_LONG_LONG:
1856                                num = get_arg(long long);
1857                                break;
1858                        case FORMAT_TYPE_ULONG:
1859                        case FORMAT_TYPE_LONG:
1860                                num = get_arg(unsigned long);
1861                                break;
1862                        case FORMAT_TYPE_SIZE_T:
1863                                num = get_arg(size_t);
1864                                break;
1865                        case FORMAT_TYPE_PTRDIFF:
1866                                num = get_arg(ptrdiff_t);
1867                                break;
1868                        case FORMAT_TYPE_UBYTE:
1869                                num = get_arg(unsigned char);
1870                                break;
1871                        case FORMAT_TYPE_BYTE:
1872                                num = get_arg(signed char);
1873                                break;
1874                        case FORMAT_TYPE_USHORT:
1875                                num = get_arg(unsigned short);
1876                                break;
1877                        case FORMAT_TYPE_SHORT:
1878                                num = get_arg(short);
1879                                break;
1880                        case FORMAT_TYPE_UINT:
1881                                num = get_arg(unsigned int);
1882                                break;
1883                        default:
1884                                num = get_arg(int);
1885                        }
1886
1887                        str = number(str, end, num, spec);
1888                } /* default: */
1889                } /* switch(spec.type) */
1890        } /* while(*fmt) */
1891
1892        if (size > 0) {
1893                if (str < end)
1894                        *str = '\0';
1895                else
1896                        end[-1] = '\0';
1897        }
1898
1899#undef get_arg
1900
1901        /* the trailing null byte doesn't count towards the total */
1902        return str - buf;
1903}
1904EXPORT_SYMBOL_GPL(bstr_printf);
1905
1906/**
1907 * bprintf - Parse a format string and place args' binary value in a buffer
1908 * @bin_buf: The buffer to place args' binary value
1909 * @size: The size of the buffer(by words(32bits), not characters)
1910 * @fmt: The format string to use
1911 * @...: Arguments for the format string
1912 *
1913 * The function returns the number of words(u32) written
1914 * into @bin_buf.
1915 */
1916int bprintf(u32 *bin_buf, size_t size, const char *fmt, ...)
1917{
1918        va_list args;
1919        int ret;
1920
1921        va_start(args, fmt);
1922        ret = vbin_printf(bin_buf, size, fmt, args);
1923        va_end(args);
1924
1925        return ret;
1926}
1927EXPORT_SYMBOL_GPL(bprintf);
1928
1929#endif /* CONFIG_BINARY_PRINTF */
1930
1931/**
1932 * vsscanf - Unformat a buffer into a list of arguments
1933 * @buf:        input buffer
1934 * @fmt:        format of buffer
1935 * @args:       arguments
1936 */
1937int vsscanf(const char *buf, const char *fmt, va_list args)
1938{
1939        const char *str = buf;
1940        char *next;
1941        char digit;
1942        int num = 0;
1943        u8 qualifier;
1944        u8 base;
1945        s16 field_width;
1946        bool is_sign;
1947
1948        while (*fmt && *str) {
1949                /* skip any white space in format */
1950                /* white space in format matchs any amount of
1951                 * white space, including none, in the input.
1952                 */
1953                if (isspace(*fmt)) {
1954                        fmt = skip_spaces(++fmt);
1955                        str = skip_spaces(str);
1956                }
1957
1958                /* anything that is not a conversion must match exactly */
1959                if (*fmt != '%' && *fmt) {
1960                        if (*fmt++ != *str++)
1961                                break;
1962                        continue;
1963                }
1964
1965                if (!*fmt)
1966                        break;
1967                ++fmt;
1968
1969                /* skip this conversion.
1970                 * advance both strings to next white space
1971                 */
1972                if (*fmt == '*') {
1973                        while (!isspace(*fmt) && *fmt != '%' && *fmt)
1974                                fmt++;
1975                        while (!isspace(*str) && *str)
1976                                str++;
1977                        continue;
1978                }
1979
1980                /* get field width */
1981                field_width = -1;
1982                if (isdigit(*fmt))
1983                        field_width = skip_atoi(&fmt);
1984
1985                /* get conversion qualifier */
1986                qualifier = -1;
1987                if (*fmt == 'h' || _tolower(*fmt) == 'l' ||
1988                    _tolower(*fmt) == 'z') {
1989                        qualifier = *fmt++;
1990                        if (unlikely(qualifier == *fmt)) {
1991                                if (qualifier == 'h') {
1992                                        qualifier = 'H';
1993                                        fmt++;
1994                                } else if (qualifier == 'l') {
1995                                        qualifier = 'L';
1996                                        fmt++;
1997                                }
1998                        }
1999                }
2000
2001                if (!*fmt || !*str)
2002                        break;
2003
2004                base = 10;
2005                is_sign = 0;
2006
2007                switch (*fmt++) {
2008                case 'c':
2009                {
2010                        char *s = (char *)va_arg(args, char*);
2011                        if (field_width == -1)
2012                                field_width = 1;
2013                        do {
2014                                *s++ = *str++;
2015                        } while (--field_width > 0 && *str);
2016                        num++;
2017                }
2018                continue;
2019                case 's':
2020                {
2021                        char *s = (char *)va_arg(args, char *);
2022                        if (field_width == -1)
2023                                field_width = SHRT_MAX;
2024                        /* first, skip leading white space in buffer */
2025                        str = skip_spaces(str);
2026
2027                        /* now copy until next white space */
2028                        while (*str && !isspace(*str) && field_width--)
2029                                *s++ = *str++;
2030                        *s = '\0';
2031                        num++;
2032                }
2033                continue;
2034                case 'n':
2035                        /* return number of characters read so far */
2036                {
2037                        int *i = (int *)va_arg(args, int*);
2038                        *i = str - buf;
2039                }
2040                continue;
2041                case 'o':
2042                        base = 8;
2043                        break;
2044                case 'x':
2045                case 'X':
2046                        base = 16;
2047                        break;
2048                case 'i':
2049                        base = 0;
2050                case 'd':
2051                        is_sign = 1;
2052                case 'u':
2053                        break;
2054                case '%':
2055                        /* looking for '%' in str */
2056                        if (*str++ != '%')
2057                                return num;
2058                        continue;
2059                default:
2060                        /* invalid format; stop here */
2061                        return num;
2062                }
2063
2064                /* have some sort of integer conversion.
2065                 * first, skip white space in buffer.
2066                 */
2067                str = skip_spaces(str);
2068
2069                digit = *str;
2070                if (is_sign && digit == '-')
2071                        digit = *(str + 1);
2072
2073                if (!digit
2074                    || (base == 16 && !isxdigit(digit))
2075                    || (base == 10 && !isdigit(digit))
2076                    || (base == 8 && (!isdigit(digit) || digit > '7'))
2077                    || (base == 0 && !isdigit(digit)))
2078                        break;
2079
2080                switch (qualifier) {
2081                case 'H':       /* that's 'hh' in format */
2082                        if (is_sign) {
2083                                signed char *s = (signed char *)va_arg(args, signed char *);
2084                                *s = (signed char)simple_strtol(str, &next, base);
2085                        } else {
2086                                unsigned char *s = (unsigned char *)va_arg(args, unsigned char *);
2087                                *s = (unsigned char)simple_strtoul(str, &next, base);
2088                        }
2089                        break;
2090                case 'h':
2091                        if (is_sign) {
2092                                short *s = (short *)va_arg(args, short *);
2093                                *s = (short)simple_strtol(str, &next, base);
2094                        } else {
2095                                unsigned short *s = (unsigned short *)va_arg(args, unsigned short *);
2096                                *s = (unsigned short)simple_strtoul(str, &next, base);
2097                        }
2098                        break;
2099                case 'l':
2100                        if (is_sign) {
2101                                long *l = (long *)va_arg(args, long *);
2102                                *l = simple_strtol(str, &next, base);
2103                        } else {
2104                                unsigned long *l = (unsigned long *)va_arg(args, unsigned long *);
2105                                *l = simple_strtoul(str, &next, base);
2106                        }
2107                        break;
2108                case 'L':
2109                        if (is_sign) {
2110                                long long *l = (long long *)va_arg(args, long long *);
2111                                *l = simple_strtoll(str, &next, base);
2112                        } else {
2113                                unsigned long long *l = (unsigned long long *)va_arg(args, unsigned long long *);
2114                                *l = simple_strtoull(str, &next, base);
2115                        }
2116                        break;
2117                case 'Z':
2118                case 'z':
2119                {
2120                        size_t *s = (size_t *)va_arg(args, size_t *);
2121                        *s = (size_t)simple_strtoul(str, &next, base);
2122                }
2123                break;
2124                default:
2125                        if (is_sign) {
2126                                int *i = (int *)va_arg(args, int *);
2127                                *i = (int)simple_strtol(str, &next, base);
2128                        } else {
2129                                unsigned int *i = (unsigned int *)va_arg(args, unsigned int*);
2130                                *i = (unsigned int)simple_strtoul(str, &next, base);
2131                        }
2132                        break;
2133                }
2134                num++;
2135
2136                if (!next)
2137                        break;
2138                str = next;
2139        }
2140
2141        /*
2142         * Now we've come all the way through so either the input string or the
2143         * format ended. In the former case, there can be a %n at the current
2144         * position in the format that needs to be filled.
2145         */
2146        if (*fmt == '%' && *(fmt + 1) == 'n') {
2147                int *p = (int *)va_arg(args, int *);
2148                *p = str - buf;
2149        }
2150
2151        return num;
2152}
2153EXPORT_SYMBOL(vsscanf);
2154
2155/**
2156 * sscanf - Unformat a buffer into a list of arguments
2157 * @buf:        input buffer
2158 * @fmt:        formatting of buffer
2159 * @...:        resulting arguments
2160 */
2161int sscanf(const char *buf, const char *fmt, ...)
2162{
2163        va_list args;
2164        int i;
2165
2166        va_start(args, fmt);
2167        i = vsscanf(buf, fmt, args);
2168        va_end(args);
2169
2170        return i;
2171}
2172EXPORT_SYMBOL(sscanf);
2173
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