lib/vsprintf.c

   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>
  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 /* Works only for digits and letters, but small and fast */
  35 #define TOLOWER(x) ((x) | 0x20)
  36
  37 static unsigned int simple_guess_base(const char *cp)
  38 {
  39         if (cp[0] == '0') {
  40                 if (TOLOWER(cp[1]) == 'x' && isxdigit(cp[2]))
  41                         return 16;
  42                 else
  43                         return 8;
  44         } else {
  45                 return 10;
  46         }
  47 }
  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 unsigned long long simple_strtoull(const char *cp, char **endp, unsigned int base)
  56 {
  57         unsigned long long result = 0;
  58
  59         if (!base)
  60                 base = simple_guess_base(cp);
  61
  62         if (base == 16 && cp[0] == '0' && TOLOWER(cp[1]) == 'x')
  63                 cp += 2;
  64
  65         while (isxdigit(*cp)) {
  66                 unsigned int value;
  67
  68                 value = isdigit(*cp) ? *cp - '0' : TOLOWER(*cp) - 'a' + 10;
  69                 if (value >= base)
  70                         break;
  71                 result = result * base + value;
  72                 cp++;
  73         }
  74         if (endp)
  75                 *endp = (char *)cp;
  76
  77         return result;
  78 }
  79 EXPORT_SYMBOL(simple_strtoull);
  80
  81 /**
  82  * simple_strtoul - convert a string to an unsigned long
  83  * @cp: The start of the string
  84  * @endp: A pointer to the end of the parsed string will be placed here
  85  * @base: The number base to use
  86  */
  87 unsigned long simple_strtoul(const char *cp, char **endp, unsigned int base)
  88 {
  89         return simple_strtoull(cp, endp, base);
  90 }
  91 EXPORT_SYMBOL(simple_strtoul);
  92
  93 /**
  94  * simple_strtol - convert a string to a signed long
  95  * @cp: The start of the string
  96  * @endp: A pointer to the end of the parsed string will be placed here
  97  * @base: The number base to use
  98  */
  99 long simple_strtol(const char *cp, char **endp, unsigned int base)
 100 {
 101         if (*cp == '-')
 102                 return -simple_strtoul(cp + 1, endp, base);
 103
 104         return simple_strtoul(cp, endp, base);
 105 }
 106 EXPORT_SYMBOL(simple_strtol);
 107
 108 /**
 109  * simple_strtoll - convert a string to a signed long long
 110  * @cp: The start of the string
 111  * @endp: A pointer to the end of the parsed string will be placed here
 112  * @base: The number base to use
 113  */
 114 long long simple_strtoll(const char *cp, char **endp, unsigned int base)
 115 {
 116         if (*cp == '-')
 117                 return -simple_strtoull(cp + 1, endp, base);
 118
 119         return simple_strtoull(cp, endp, base);
 120 }
 121 EXPORT_SYMBOL(simple_strtoll);
 122
 123 /**
 124  * strict_strtoul - convert a string to an unsigned long strictly
 125  * @cp: The string to be converted
 126  * @base: The number base to use
 127  * @res: The converted result value
 128  *
 129  * strict_strtoul converts a string to an unsigned long only if the
 130  * string is really an unsigned long string, any string containing
 131  * any invalid char at the tail will be rejected and -EINVAL is returned,
 132  * only a newline char at the tail is acceptible because people generally
 133  * change a module parameter in the following way:
 134  *
 135  *      echo 1024 > /sys/module/e1000/parameters/copybreak
 136  *
 137  * echo will append a newline to the tail.
 138  *
 139  * It returns 0 if conversion is successful and *res is set to the converted
 140  * value, otherwise it returns -EINVAL and *res is set to 0.
 141  *
 142  * simple_strtoul just ignores the successive invalid characters and
 143  * return the converted value of prefix part of the string.
 144  */
 145 int strict_strtoul(const char *cp, unsigned int base, unsigned long *res)
 146 {
 147         char *tail;
 148         unsigned long val;
 149         size_t len;
 150
 151         *res = 0;
 152         len = strlen(cp);
 153         if (len == 0)
 154                 return -EINVAL;
 155
 156         val = simple_strtoul(cp, &tail, base);
 157         if (tail == cp)
 158                 return -EINVAL;
 159
 160         if ((*tail == '\0') ||
 161                 ((len == (size_t)(tail - cp) + 1) && (*tail == '\n'))) {
 162                 *res = val;
 163                 return 0;
 164         }
 165
 166         return -EINVAL;
 167 }
 168 EXPORT_SYMBOL(strict_strtoul);
 169
 170 /**
 171  * strict_strtol - convert a string to a long strictly
 172  * @cp: The string to be converted
 173  * @base: The number base to use
 174  * @res: The converted result value
 175  *
 176  * strict_strtol is similiar to strict_strtoul, but it allows the first
 177  * character of a string is '-'.
 178  *
 179  * It returns 0 if conversion is successful and *res is set to the converted
 180  * value, otherwise it returns -EINVAL and *res is set to 0.
 181  */
 182 int strict_strtol(const char *cp, unsigned int base, long *res)
 183 {
 184         int ret;
 185         if (*cp == '-') {
 186                 ret = strict_strtoul(cp + 1, base, (unsigned long *)res);
 187                 if (!ret)
 188                         *res = -(*res);
 189         } else {
 190                 ret = strict_strtoul(cp, base, (unsigned long *)res);
 191         }
 192
 193         return ret;
 194 }
 195 EXPORT_SYMBOL(strict_strtol);
 196
 197 /**
 198  * strict_strtoull - convert a string to an unsigned long long strictly
 199  * @cp: The string to be converted
 200  * @base: The number base to use
 201  * @res: The converted result value
 202  *
 203  * strict_strtoull converts a string to an unsigned long long only if the
 204  * string is really an unsigned long long string, any string containing
 205  * any invalid char at the tail will be rejected and -EINVAL is returned,
 206  * only a newline char at the tail is acceptible because people generally
 207  * change a module parameter in the following way:
 208  *
 209  *      echo 1024 > /sys/module/e1000/parameters/copybreak
 210  *
 211  * echo will append a newline to the tail of the string.
 212  *
 213  * It returns 0 if conversion is successful and *res is set to the converted
 214  * value, otherwise it returns -EINVAL and *res is set to 0.
 215  *
 216  * simple_strtoull just ignores the successive invalid characters and
 217  * return the converted value of prefix part of the string.
 218  */
 219 int strict_strtoull(const char *cp, unsigned int base, unsigned long long *res)
 220 {
 221         char *tail;
 222         unsigned long long val;
 223         size_t len;
 224
 225         *res = 0;
 226         len = strlen(cp);
 227         if (len == 0)
 228                 return -EINVAL;
 229
 230         val = simple_strtoull(cp, &tail, base);
 231         if (tail == cp)
 232                 return -EINVAL;
 233         if ((*tail == '\0') ||
 234                 ((len == (size_t)(tail - cp) + 1) && (*tail == '\n'))) {
 235                 *res = val;
 236                 return 0;
 237         }
 238
 239         return -EINVAL;
 240 }
 241 EXPORT_SYMBOL(strict_strtoull);
 242
 243 /**
 244  * strict_strtoll - convert a string to a long long strictly
 245  * @cp: The string to be converted
 246  * @base: The number base to use
 247  * @res: The converted result value
 248  *
 249  * strict_strtoll is similiar to strict_strtoull, but it allows the first
 250  * character of a string is '-'.
 251  *
 252  * It returns 0 if conversion is successful and *res is set to the converted
 253  * value, otherwise it returns -EINVAL and *res is set to 0.
 254  */
 255 int strict_strtoll(const char *cp, unsigned int base, long long *res)
 256 {
 257         int ret;
 258         if (*cp == '-') {
 259                 ret = strict_strtoull(cp + 1, base, (unsigned long long *)res);
 260                 if (!ret)
 261                         *res = -(*res);
 262         } else {
 263                 ret = strict_strtoull(cp, base, (unsigned long long *)res);
 264         }
 265
 266         return ret;
 267 }
 268 EXPORT_SYMBOL(strict_strtoll);
 269
 270 static noinline_for_stack
 271 int skip_atoi(const char **s)
 272 {
 273         int i = 0;
 274
 275         while (isdigit(**s))
 276                 i = i*10 + *((*s)++) - '0';
 277
 278         return i;
 279 }
 280
 281 /* Decimal conversion is by far the most typical, and is used
 282  * for /proc and /sys data. This directly impacts e.g. top performance
 283  * with many processes running. We optimize it for speed
 284  * using code from
 285  * http://www.cs.uiowa.edu/~jones/bcd/decimal.html
 286  * (with permission from the author, Douglas W. Jones). */
 287
 288 /* Formats correctly any integer in [0,99999].
 289  * Outputs from one to five digits depending on input.
 290  * On i386 gcc 4.1.2 -O2: ~250 bytes of code. */
 291 static noinline_for_stack
 292 char *put_dec_trunc(char *buf, unsigned q)
 293 {
 294         unsigned d3, d2, d1, d0;
 295         d1 = (q>>4) & 0xf;
 296         d2 = (q>>8) & 0xf;
 297         d3 = (q>>12);
 298
 299         d0 = 6*(d3 + d2 + d1) + (q & 0xf);
 300         q = (d0 * 0xcd) >> 11;
 301         d0 = d0 - 10*q;
 302         *buf++ = d0 + '0'; /* least significant digit */
 303         d1 = q + 9*d3 + 5*d2 + d1;
 304         if (d1 != 0) {
 305                 q = (d1 * 0xcd) >> 11;
 306                 d1 = d1 - 10*q;
 307                 *buf++ = d1 + '0'; /* next digit */
 308
 309                 d2 = q + 2*d2;
 310                 if ((d2 != 0) || (d3 != 0)) {
 311                         q = (d2 * 0xd) >> 7;
 312                         d2 = d2 - 10*q;
 313                         *buf++ = d2 + '0'; /* next digit */
 314
 315                         d3 = q + 4*d3;
 316                         if (d3 != 0) {
 317                                 q = (d3 * 0xcd) >> 11;
 318                                 d3 = d3 - 10*q;
 319                                 *buf++ = d3 + '0';  /* next digit */
 320                                 if (q != 0)
 321                                         *buf++ = q + '0'; /* most sign. digit */
 322                         }
 323                 }
 324         }
 325
 326         return buf;
 327 }
 328 /* Same with if's removed. Always emits five digits */
 329 static noinline_for_stack
 330 char *put_dec_full(char *buf, unsigned q)
 331 {
 332         /* BTW, if q is in [0,9999], 8-bit ints will be enough, */
 333         /* but anyway, gcc produces better code with full-sized ints */
 334         unsigned d3, d2, d1, d0;
 335         d1 = (q>>4) & 0xf;
 336         d2 = (q>>8) & 0xf;
 337         d3 = (q>>12);
 338
 339         /*
 340          * Possible ways to approx. divide by 10
 341          * gcc -O2 replaces multiply with shifts and adds
 342          * (x * 0xcd) >> 11: 11001101 - shorter code than * 0x67 (on i386)
 343          * (x * 0x67) >> 10:  1100111
 344          * (x * 0x34) >> 9:    110100 - same
 345          * (x * 0x1a) >> 8:     11010 - same
 346          * (x * 0x0d) >> 7:      1101 - same, shortest code (on i386)
 347          */
 348         d0 = 6*(d3 + d2 + d1) + (q & 0xf);
 349         q = (d0 * 0xcd) >> 11;
 350         d0 = d0 - 10*q;
 351         *buf++ = d0 + '0';
 352         d1 = q + 9*d3 + 5*d2 + d1;
 353                 q = (d1 * 0xcd) >> 11;
 354                 d1 = d1 - 10*q;
 355                 *buf++ = d1 + '0';
 356
 357                 d2 = q + 2*d2;
 358                         q = (d2 * 0xd) >> 7;
 359                         d2 = d2 - 10*q;
 360                         *buf++ = d2 + '0';
 361
 362                         d3 = q + 4*d3;
 363                                 q = (d3 * 0xcd) >> 11; /* - shorter code */
 364                                 /* q = (d3 * 0x67) >> 10; - would also work */
 365                                 d3 = d3 - 10*q;
 366                                 *buf++ = d3 + '0';
 367                                         *buf++ = q + '0';
 368
 369         return buf;
 370 }
 371 /* No inlining helps gcc to use registers better */
 372 static noinline_for_stack
 373 char *put_dec(char *buf, unsigned long long num)
 374 {
 375         while (1) {
 376                 unsigned rem;
 377                 if (num < 100000)
 378                         return put_dec_trunc(buf, num);
 379                 rem = do_div(num, 100000);
 380                 buf = put_dec_full(buf, rem);
 381         }
 382 }
 383
 384 #define ZEROPAD 1               /* pad with zero */
 385 #define SIGN    2               /* unsigned/signed long */
 386 #define PLUS    4               /* show plus */
 387 #define SPACE   8               /* space if plus */
 388 #define LEFT    16              /* left justified */
 389 #define SMALL   32              /* use lowercase in hex (must be 32 == 0x20) */
 390 #define SPECIAL 64              /* prefix hex with "0x", octal with "0" */
 391
 392 enum format_type {
 393         FORMAT_TYPE_NONE, /* Just a string part */
 394         FORMAT_TYPE_WIDTH,
 395         FORMAT_TYPE_PRECISION,
 396         FORMAT_TYPE_CHAR,
 397         FORMAT_TYPE_STR,
 398         FORMAT_TYPE_PTR,
 399         FORMAT_TYPE_PERCENT_CHAR,
 400         FORMAT_TYPE_INVALID,
 401         FORMAT_TYPE_LONG_LONG,
 402         FORMAT_TYPE_ULONG,
 403         FORMAT_TYPE_LONG,
 404         FORMAT_TYPE_UBYTE,
 405         FORMAT_TYPE_BYTE,
 406         FORMAT_TYPE_USHORT,
 407         FORMAT_TYPE_SHORT,
 408         FORMAT_TYPE_UINT,
 409         FORMAT_TYPE_INT,
 410         FORMAT_TYPE_NRCHARS,
 411         FORMAT_TYPE_SIZE_T,
 412         FORMAT_TYPE_PTRDIFF
 413 };
 414
 415 struct printf_spec {
 416         u8      type;           /* format_type enum */
 417         u8      flags;          /* flags to number() */
 418         u8      base;           /* number base, 8, 10 or 16 only */
 419         u8      qualifier;      /* number qualifier, one of 'hHlLtzZ' */
 420         s16     field_width;    /* width of output field */
 421         s16     precision;      /* # of digits/chars */
 422 };
 423
 424 static noinline_for_stack
 425 char *number(char *buf, char *end, unsigned long long num,
 426              struct printf_spec spec)
 427 {
 428         /* we are called with base 8, 10 or 16, only, thus don't need "G..."  */
 429         static const char digits[16] = "0123456789ABCDEF"; /* "GHIJKLMNOPQRSTUVWXYZ"; */
 430
 431         char tmp[66];
 432         char sign;
 433         char locase;
 434         int need_pfx = ((spec.flags & SPECIAL) && spec.base != 10);
 435         int i;
 436
 437         /* locase = 0 or 0x20. ORing digits or letters with 'locase'
 438          * produces same digits or (maybe lowercased) letters */
 439         locase = (spec.flags & SMALL);
 440         if (spec.flags & LEFT)
 441                 spec.flags &= ~ZEROPAD;
 442         sign = 0;
 443         if (spec.flags & SIGN) {
 444                 if ((signed long long)num < 0) {
 445                         sign = '-';
 446                         num = -(signed long long)num;
 447                         spec.field_width--;
 448                 } else if (spec.flags & PLUS) {
 449                         sign = '+';
 450                         spec.field_width--;
 451                 } else if (spec.flags & SPACE) {
 452                         sign = ' ';
 453                         spec.field_width--;
 454                 }
 455         }
 456         if (need_pfx) {
 457                 spec.field_width--;
 458                 if (spec.base == 16)
 459                         spec.field_width--;
 460         }
 461
 462         /* generate full string in tmp[], in reverse order */
 463         i = 0;
 464         if (num == 0)
 465                 tmp[i++] = '0';
 466         /* Generic code, for any base:
 467         else do {
 468                 tmp[i++] = (digits[do_div(num,base)] | locase);
 469         } while (num != 0);
 470         */
 471         else if (spec.base != 10) { /* 8 or 16 */
 472                 int mask = spec.base - 1;
 473                 int shift = 3;
 474
 475                 if (spec.base == 16)
 476                         shift = 4;
 477                 do {
 478                         tmp[i++] = (digits[((unsigned char)num) & mask] | locase);
 479                         num >>= shift;
 480                 } while (num);
 481         } else { /* base 10 */
 482                 i = put_dec(tmp, num) - tmp;
 483         }
 484
 485         /* printing 100 using %2d gives "100", not "00" */
 486         if (i > spec.precision)
 487                 spec.precision = i;
 488         /* leading space padding */
 489         spec.field_width -= spec.precision;
 490         if (!(spec.flags & (ZEROPAD+LEFT))) {
 491                 while (--spec.field_width >= 0) {
 492                         if (buf < end)
 493                                 *buf = ' ';
 494                         ++buf;
 495                 }
 496         }
 497         /* sign */
 498         if (sign) {
 499                 if (buf < end)
 500                         *buf = sign;
 501                 ++buf;
 502         }
 503         /* "0x" / "0" prefix */
 504         if (need_pfx) {
 505                 if (buf < end)
 506                         *buf = '0';
 507                 ++buf;
 508                 if (spec.base == 16) {
 509                         if (buf < end)
 510                                 *buf = ('X' | locase);
 511                         ++buf;
 512                 }
 513         }
 514         /* zero or space padding */
 515         if (!(spec.flags & LEFT)) {
 516                 char c = (spec.flags & ZEROPAD) ? '0' : ' ';
 517                 while (--spec.field_width >= 0) {
 518                         if (buf < end)
 519                                 *buf = c;
 520                         ++buf;
 521                 }
 522         }
 523         /* hmm even more zero padding? */
 524         while (i <= --spec.precision) {
 525                 if (buf < end)
 526                         *buf = '0';
 527                 ++buf;
 528         }
 529         /* actual digits of result */
 530         while (--i >= 0) {
 531                 if (buf < end)
 532                         *buf = tmp[i];
 533                 ++buf;
 534         }
 535         /* trailing space padding */
 536         while (--spec.field_width >= 0) {
 537                 if (buf < end)
 538                         *buf = ' ';
 539                 ++buf;
 540         }
 541
 542         return buf;
 543 }
 544
 545 static noinline_for_stack
 546 char *string(char *buf, char *end, const char *s, struct printf_spec spec)
 547 {
 548         int len, i;
 549
 550         if ((unsigned long)s < PAGE_SIZE)
 551                 s = "(null)";
 552
 553         len = strnlen(s, spec.precision);
 554
 555         if (!(spec.flags & LEFT)) {
 556                 while (len < spec.field_width--) {
 557                         if (buf < end)
 558                                 *buf = ' ';
 559                         ++buf;
 560                 }
 561         }
 562         for (i = 0; i < len; ++i) {
 563                 if (buf < end)
 564                         *buf = *s;
 565                 ++buf; ++s;
 566         }
 567         while (len < spec.field_width--) {
 568                 if (buf < end)
 569                         *buf = ' ';
 570                 ++buf;
 571         }
 572
 573         return buf;
 574 }
 575
 576 static noinline_for_stack
 577 char *symbol_string(char *buf, char *end, void *ptr,
 578                     struct printf_spec spec, char ext)
 579 {
 580         unsigned long value = (unsigned long) ptr;
 581 #ifdef CONFIG_KALLSYMS
 582         char sym[KSYM_SYMBOL_LEN];
 583         if (ext != 'f' && ext != 's')
 584                 sprint_symbol(sym, value);
 585         else
 586                 kallsyms_lookup(value, NULL, NULL, NULL, sym);
 587
 588         return string(buf, end, sym, spec);
 589 #else
 590         spec.field_width = 2 * sizeof(void *);
 591         spec.flags |= SPECIAL | SMALL | ZEROPAD;
 592         spec.base = 16;
 593
 594         return number(buf, end, value, spec);
 595 #endif
 596 }
 597
 598 static noinline_for_stack
 599 char *resource_string(char *buf, char *end, struct resource *res,
 600                       struct printf_spec spec, const char *fmt)
 601 {
 602 #ifndef IO_RSRC_PRINTK_SIZE
 603 #define IO_RSRC_PRINTK_SIZE     6
 604 #endif
 605
 606 #ifndef MEM_RSRC_PRINTK_SIZE
 607 #define MEM_RSRC_PRINTK_SIZE    10
 608 #endif
 609         static const struct printf_spec io_spec = {
 610                 .base = 16,
 611                 .field_width = IO_RSRC_PRINTK_SIZE,
 612                 .precision = -1,
 613                 .flags = SPECIAL | SMALL | ZEROPAD,
 614         };
 615         static const struct printf_spec mem_spec = {
 616                 .base = 16,
 617                 .field_width = MEM_RSRC_PRINTK_SIZE,
 618                 .precision = -1,
 619                 .flags = SPECIAL | SMALL | ZEROPAD,
 620         };
 621         static const struct printf_spec bus_spec = {
 622                 .base = 16,
 623                 .field_width = 2,
 624                 .precision = -1,
 625                 .flags = SMALL | ZEROPAD,
 626         };
 627         static const struct printf_spec dec_spec = {
 628                 .base = 10,
 629                 .precision = -1,
 630                 .flags = 0,
 631         };
 632         static const struct printf_spec str_spec = {
 633                 .field_width = -1,
 634                 .precision = 10,
 635                 .flags = LEFT,
 636         };
 637         static const struct printf_spec flag_spec = {
 638                 .base = 16,
 639                 .precision = -1,
 640                 .flags = SPECIAL | SMALL,
 641         };
 642
 643         /* 32-bit res (sizeof==4): 10 chars in dec, 10 in hex ("0x" + 8)
 644          * 64-bit res (sizeof==8): 20 chars in dec, 18 in hex ("0x" + 16) */
 645 #define RSRC_BUF_SIZE           ((2 * sizeof(resource_size_t)) + 4)
 646 #define FLAG_BUF_SIZE           (2 * sizeof(res->flags))
 647 #define DECODED_BUF_SIZE        sizeof("[mem - 64bit pref window disabled]")
 648 #define RAW_BUF_SIZE            sizeof("[mem - flags 0x]")
 649         char sym[max(2*RSRC_BUF_SIZE + DECODED_BUF_SIZE,
 650                      2*RSRC_BUF_SIZE + FLAG_BUF_SIZE + RAW_BUF_SIZE)];
 651
 652         char *p = sym, *pend = sym + sizeof(sym);
 653         int decode = (fmt[0] == 'R') ? 1 : 0;
 654         const struct printf_spec *specp;
 655
 656         *p++ = '[';
 657         if (res->flags & IORESOURCE_IO) {
 658                 p = string(p, pend, "io  ", str_spec);
 659                 specp = &io_spec;
 660         } else if (res->flags & IORESOURCE_MEM) {
 661                 p = string(p, pend, "mem ", str_spec);
 662                 specp = &mem_spec;
 663         } else if (res->flags & IORESOURCE_IRQ) {
 664                 p = string(p, pend, "irq ", str_spec);
 665                 specp = &dec_spec;
 666         } else if (res->flags & IORESOURCE_DMA) {
 667                 p = string(p, pend, "dma ", str_spec);
 668                 specp = &dec_spec;
 669         } else if (res->flags & IORESOURCE_BUS) {
 670                 p = string(p, pend, "bus ", str_spec);
 671                 specp = &bus_spec;
 672         } else {
 673                 p = string(p, pend, "??? ", str_spec);
 674                 specp = &mem_spec;
 675                 decode = 0;
 676         }
 677         p = number(p, pend, res->start, *specp);
 678         if (res->start != res->end) {
 679                 *p++ = '-';
 680                 p = number(p, pend, res->end, *specp);
 681         }
 682         if (decode) {
 683                 if (res->flags & IORESOURCE_MEM_64)
 684                         p = string(p, pend, " 64bit", str_spec);
 685                 if (res->flags & IORESOURCE_PREFETCH)
 686                         p = string(p, pend, " pref", str_spec);
 687                 if (res->flags & IORESOURCE_WINDOW)
 688                         p = string(p, pend, " window", str_spec);
 689                 if (res->flags & IORESOURCE_DISABLED)
 690                         p = string(p, pend, " disabled", str_spec);
 691         } else {
 692                 p = string(p, pend, " flags ", str_spec);
 693                 p = number(p, pend, res->flags, flag_spec);
 694         }
 695         *p++ = ']';
 696         *p = '\0';
 697
 698         return string(buf, end, sym, spec);
 699 }
 700
 701 static noinline_for_stack
 702 char *mac_address_string(char *buf, char *end, u8 *addr,
 703                          struct printf_spec spec, const char *fmt)
 704 {
 705         char mac_addr[sizeof("xx:xx:xx:xx:xx:xx")];
 706         char *p = mac_addr;
 707         int i;
 708         char separator;
 709
 710         if (fmt[1] == 'F') {            /* FDDI canonical format */
 711                 separator = '-';
 712         } else {
 713                 separator = ':';
 714         }
 715
 716         for (i = 0; i < 6; i++) {
 717                 p = pack_hex_byte(p, addr[i]);
 718                 if (fmt[0] == 'M' && i != 5)
 719                         *p++ = separator;
 720         }
 721         *p = '\0';
 722
 723         return string(buf, end, mac_addr, spec);
 724 }
 725
 726 static noinline_for_stack
 727 char *ip4_string(char *p, const u8 *addr, const char *fmt)
 728 {
 729         int i;
 730         bool leading_zeros = (fmt[0] == 'i');
 731         int index;
 732         int step;
 733
 734         switch (fmt[2]) {
 735         case 'h':
 736 #ifdef __BIG_ENDIAN
 737                 index = 0;
 738                 step = 1;
 739 #else
 740                 index = 3;
 741                 step = -1;
 742 #endif
 743                 break;
 744         case 'l':
 745                 index = 3;
 746                 step = -1;
 747                 break;
 748         case 'n':
 749         case 'b':
 750         default:
 751                 index = 0;
 752                 step = 1;
 753                 break;
 754         }
 755         for (i = 0; i < 4; i++) {
 756                 char temp[3];   /* hold each IP quad in reverse order */
 757                 int digits = put_dec_trunc(temp, addr[index]) - temp;
 758                 if (leading_zeros) {
 759                         if (digits < 3)
 760                                 *p++ = '0';
 761                         if (digits < 2)
 762                                 *p++ = '0';
 763                 }
 764                 /* reverse the digits in the quad */
 765                 while (digits--)
 766                         *p++ = temp[digits];
 767                 if (i < 3)
 768                         *p++ = '.';
 769                 index += step;
 770         }
 771         *p = '\0';
 772
 773         return p;
 774 }
 775
 776 static noinline_for_stack
 777 char *ip6_compressed_string(char *p, const char *addr)
 778 {
 779         int i, j, range;
 780         unsigned char zerolength[8];
 781         int longest = 1;
 782         int colonpos = -1;
 783         u16 word;
 784         u8 hi, lo;
 785         bool needcolon = false;
 786         bool useIPv4;
 787         struct in6_addr in6;
 788
 789         memcpy(&in6, addr, sizeof(struct in6_addr));
 790
 791         useIPv4 = ipv6_addr_v4mapped(&in6) || ipv6_addr_is_isatap(&in6);
 792
 793         memset(zerolength, 0, sizeof(zerolength));
 794
 795         if (useIPv4)
 796                 range = 6;
 797         else
 798                 range = 8;
 799
 800         /* find position of longest 0 run */
 801         for (i = 0; i < range; i++) {
 802                 for (j = i; j < range; j++) {
 803                         if (in6.s6_addr16[j] != 0)
 804                                 break;
 805                         zerolength[i]++;
 806                 }
 807         }
 808         for (i = 0; i < range; i++) {
 809                 if (zerolength[i] > longest) {
 810                         longest = zerolength[i];
 811                         colonpos = i;
 812                 }
 813         }
 814
 815         /* emit address */
 816         for (i = 0; i < range; i++) {
 817                 if (i == colonpos) {
 818                         if (needcolon || i == 0)
 819                                 *p++ = ':';
 820                         *p++ = ':';
 821                         needcolon = false;
 822                         i += longest - 1;
 823                         continue;
 824                 }
 825                 if (needcolon) {
 826                         *p++ = ':';
 827                         needcolon = false;
 828                 }
 829                 /* hex u16 without leading 0s */
 830                 word = ntohs(in6.s6_addr16[i]);
 831                 hi = word >> 8;
 832                 lo = word & 0xff;
 833                 if (hi) {
 834                         if (hi > 0x0f)
 835                                 p = pack_hex_byte(p, hi);
 836                         else
 837                                 *p++ = hex_asc_lo(hi);
 838                         p = pack_hex_byte(p, lo);
 839                 }
 840                 else if (lo > 0x0f)
 841                         p = pack_hex_byte(p, lo);
 842                 else
 843                         *p++ = hex_asc_lo(lo);
 844                 needcolon = true;
 845         }
 846
 847         if (useIPv4) {
 848                 if (needcolon)
 849                         *p++ = ':';
 850                 p = ip4_string(p, &in6.s6_addr[12], "I4");
 851         }
 852         *p = '\0';
 853
 854         return p;
 855 }
 856
 857 static noinline_for_stack
 858 char *ip6_string(char *p, const char *addr, const char *fmt)
 859 {
 860         int i;
 861
 862         for (i = 0; i < 8; i++) {
 863                 p = pack_hex_byte(p, *addr++);
 864                 p = pack_hex_byte(p, *addr++);
 865                 if (fmt[0] == 'I' && i != 7)
 866                         *p++ = ':';
 867         }
 868         *p = '\0';
 869
 870         return p;
 871 }
 872
 873 static noinline_for_stack
 874 char *ip6_addr_string(char *buf, char *end, const u8 *addr,
 875                       struct printf_spec spec, const char *fmt)
 876 {
 877         char ip6_addr[sizeof("xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255")];
 878
 879         if (fmt[0] == 'I' && fmt[2] == 'c')
 880                 ip6_compressed_string(ip6_addr, addr);
 881         else
 882                 ip6_string(ip6_addr, addr, fmt);
 883
 884         return string(buf, end, ip6_addr, spec);
 885 }
 886
 887 static noinline_for_stack
 888 char *ip4_addr_string(char *buf, char *end, const u8 *addr,
 889                       struct printf_spec spec, const char *fmt)
 890 {
 891         char ip4_addr[sizeof("255.255.255.255")];
 892
 893         ip4_string(ip4_addr, addr, fmt);
 894
 895         return string(buf, end, ip4_addr, spec);
 896 }
 897
 898 static noinline_for_stack
 899 char *uuid_string(char *buf, char *end, const u8 *addr,
 900                   struct printf_spec spec, const char *fmt)
 901 {
 902         char uuid[sizeof("xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx")];
 903         char *p = uuid;
 904         int i;
 905         static const u8 be[16] = {0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15};
 906         static const u8 le[16] = {3,2,1,0,5,4,7,6,8,9,10,11,12,13,14,15};
 907         const u8 *index = be;
 908         bool uc = false;
 909
 910         switch (*(++fmt)) {
 911         case 'L':
 912                 uc = true;              /* fall-through */
 913         case 'l':
 914                 index = le;
 915                 break;
 916         case 'B':
 917                 uc = true;
 918                 break;
 919         }
 920
 921         for (i = 0; i < 16; i++) {
 922                 p = pack_hex_byte(p, addr[index[i]]);
 923                 switch (i) {
 924                 case 3:
 925                 case 5:
 926                 case 7:
 927                 case 9:
 928                         *p++ = '-';
 929                         break;
 930                 }
 931         }
 932
 933         *p = 0;
 934
 935         if (uc) {
 936                 p = uuid;
 937                 do {
 938                         *p = toupper(*p);
 939                 } while (*(++p));
 940         }
 941
 942         return string(buf, end, uuid, spec);
 943 }
 944
 945 /*
 946  * Show a '%p' thing.  A kernel extension is that the '%p' is followed
 947  * by an extra set of alphanumeric characters that are extended format
 948  * specifiers.
 949  *
 950  * Right now we handle:
 951  *
 952  * - 'F' For symbolic function descriptor pointers with offset
 953  * - 'f' For simple symbolic function names without offset
 954  * - 'S' For symbolic direct pointers with offset
 955  * - 's' For symbolic direct pointers without offset
 956  * - 'R' For decoded struct resource, e.g., [mem 0x0-0x1f 64bit pref]
 957  * - 'r' For raw struct resource, e.g., [mem 0x0-0x1f flags 0x201]
 958  * - 'M' For a 6-byte MAC address, it prints the address in the
 959  *       usual colon-separated hex notation
 960  * - 'm' For a 6-byte MAC address, it prints the hex address without colons
 961  * - 'MF' For a 6-byte MAC FDDI address, it prints the address
 962  *       with a dash-separated hex notation
 963  * - 'I' [46] for IPv4/IPv6 addresses printed in the usual way
 964  *       IPv4 uses dot-separated decimal without leading 0's (1.2.3.4)
 965  *       IPv6 uses colon separated network-order 16 bit hex with leading 0's
 966  * - 'i' [46] for 'raw' IPv4/IPv6 addresses
 967  *       IPv6 omits the colons (01020304...0f)
 968  *       IPv4 uses dot-separated decimal with leading 0's (010.123.045.006)
 969  * - '[Ii]4[hnbl]' IPv4 addresses in host, network, big or little endian order
 970  * - 'I6c' for IPv6 addresses printed as specified by
 971  *       http://tools.ietf.org/html/draft-ietf-6man-text-addr-representation-00
 972  * - 'U' For a 16 byte UUID/GUID, it prints the UUID/GUID in the form
 973  *       "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx"
 974  *       Options for %pU are:
 975  *         b big endian lower case hex (default)
 976  *         B big endian UPPER case hex
 977  *         l little endian lower case hex
 978  *         L little endian UPPER case hex
 979  *           big endian output byte order is:
 980  *             [0][1][2][3]-[4][5]-[6][7]-[8][9]-[10][11][12][13][14][15]
 981  *           little endian output byte order is:
 982  *             [3][2][1][0]-[5][4]-[7][6]-[8][9]-[10][11][12][13][14][15]
 983  *
 984  * Note: The difference between 'S' and 'F' is that on ia64 and ppc64
 985  * function pointers are really function descriptors, which contain a
 986  * pointer to the real address.
 987  */
 988 static noinline_for_stack
 989 char *pointer(const char *fmt, char *buf, char *end, void *ptr,
 990               struct printf_spec spec)
 991 {
 992         if (!ptr)
 993                 return string(buf, end, "(null)", spec);
 994
 995         switch (*fmt) {
 996         case 'F':
 997         case 'f':
 998                 ptr = dereference_function_descriptor(ptr);
 999                 /* Fallthrough */
1000         case 'S':
1001         case 's':
1002                 return symbol_string(buf, end, ptr, spec, *fmt);
1003         case 'R':
1004         case 'r':
1005                 return resource_string(buf, end, ptr, spec, fmt);
1006         case 'M':                       /* Colon separated: 00:01:02:03:04:05 */
1007         case 'm':                       /* Contiguous: 000102030405 */
1008                                         /* [mM]F (FDDI, bit reversed) */
1009                 return mac_address_string(buf, end, ptr, spec, fmt);
1010         case 'I':                       /* Formatted IP supported
1011                                          * 4:   1.2.3.4
1012                                          * 6:   0001:0203:...:0708
1013                                          * 6c:  1::708 or 1::1.2.3.4
1014                                          */
1015         case 'i':                       /* Contiguous:
1016                                          * 4:   001.002.003.004
1017                                          * 6:   000102...0f
1018                                          */
1019                 switch (fmt[1]) {
1020                 case '6':
1021                         return ip6_addr_string(buf, end, ptr, spec, fmt);
1022                 case '4':
1023                         return ip4_addr_string(buf, end, ptr, spec, fmt);
1024                 }
1025                 break;
1026         case 'U':
1027                 return uuid_string(buf, end, ptr, spec, fmt);
1028         }
1029         spec.flags |= SMALL;
1030         if (spec.field_width == -1) {
1031                 spec.field_width = 2*sizeof(void *);
1032                 spec.flags |= ZEROPAD;
1033         }
1034         spec.base = 16;
1035
1036         return number(buf, end, (unsigned long) ptr, spec);
1037 }
1038
1039 /*
1040  * Helper function to decode printf style format.
1041  * Each call decode a token from the format and return the
1042  * number of characters read (or likely the delta where it wants
1043  * to go on the next call).
1044  * The decoded token is returned through the parameters
1045  *
1046  * 'h', 'l', or 'L' for integer fields
1047  * 'z' support added 23/7/1999 S.H.
1048  * 'z' changed to 'Z' --davidm 1/25/99
1049  * 't' added for ptrdiff_t
1050  *
1051  * @fmt: the format string
1052  * @type of the token returned
1053  * @flags: various flags such as +, -, # tokens..
1054  * @field_width: overwritten width
1055  * @base: base of the number (octal, hex, ...)
1056  * @precision: precision of a number
1057  * @qualifier: qualifier of a number (long, size_t, ...)
1058  */
1059 static noinline_for_stack
1060 int format_decode(const char *fmt, struct printf_spec *spec)
1061 {
1062         const char *start = fmt;
1063
1064         /* we finished early by reading the field width */
1065         if (spec->type == FORMAT_TYPE_WIDTH) {
1066                 if (spec->field_width < 0) {
1067                         spec->field_width = -spec->field_width;
1068                         spec->flags |= LEFT;
1069                 }
1070                 spec->type = FORMAT_TYPE_NONE;
1071                 goto precision;
1072         }
1073
1074         /* we finished early by reading the precision */
1075         if (spec->type == FORMAT_TYPE_PRECISION) {
1076                 if (spec->precision < 0)
1077                         spec->precision = 0;
1078
1079                 spec->type = FORMAT_TYPE_NONE;
1080                 goto qualifier;
1081         }
1082
1083         /* By default */
1084         spec->type = FORMAT_TYPE_NONE;
1085
1086         for (; *fmt ; ++fmt) {
1087                 if (*fmt == '%')
1088                         break;
1089         }
1090
1091         /* Return the current non-format string */
1092         if (fmt != start || !*fmt)
1093                 return fmt - start;
1094
1095         /* Process flags */
1096         spec->flags = 0;
1097
1098         while (1) { /* this also skips first '%' */
1099                 bool found = true;
1100
1101                 ++fmt;
1102
1103                 switch (*fmt) {
1104                 case '-': spec->flags |= LEFT;    break;
1105                 case '+': spec->flags |= PLUS;    break;
1106                 case ' ': spec->flags |= SPACE;   break;
1107                 case '#': spec->flags |= SPECIAL; break;
1108                 case '0': spec->flags |= ZEROPAD; break;
1109                 default:  found = false;
1110                 }
1111
1112                 if (!found)
1113                         break;
1114         }
1115
1116         /* get field width */
1117         spec->field_width = -1;
1118
1119         if (isdigit(*fmt))
1120                 spec->field_width = skip_atoi(&fmt);
1121         else if (*fmt == '*') {
1122                 /* it's the next argument */
1123                 spec->type = FORMAT_TYPE_WIDTH;
1124                 return ++fmt - start;
1125         }
1126
1127 precision:
1128         /* get the precision */
1129         spec->precision = -1;
1130         if (*fmt == '.') {
1131                 ++fmt;
1132                 if (isdigit(*fmt)) {
1133                         spec->precision = skip_atoi(&fmt);
1134                         if (spec->precision < 0)
1135                                 spec->precision = 0;
1136                 } else if (*fmt == '*') {
1137                         /* it's the next argument */
1138                         spec->type = FORMAT_TYPE_PRECISION;
1139                         return ++fmt - start;
1140                 }
1141         }
1142
1143 qualifier:
1144         /* get the conversion qualifier */
1145         spec->qualifier = -1;
1146         if (*fmt == 'h' || TOLOWER(*fmt) == 'l' ||
1147             TOLOWER(*fmt) == 'z' || *fmt == 't') {
1148                 spec->qualifier = *fmt++;
1149                 if (unlikely(spec->qualifier == *fmt)) {
1150                         if (spec->qualifier == 'l') {
1151                                 spec->qualifier = 'L';
1152                                 ++fmt;
1153                         } else if (spec->qualifier == 'h') {
1154                                 spec->qualifier = 'H';
1155                                 ++fmt;
1156                         }
1157                 }
1158         }
1159
1160         /* default base */
1161         spec->base = 10;
1162         switch (*fmt) {
1163         case 'c':
1164                 spec->type = FORMAT_TYPE_CHAR;
1165                 return ++fmt - start;
1166
1167         case 's':
1168                 spec->type = FORMAT_TYPE_STR;
1169                 return ++fmt - start;
1170
1171         case 'p':
1172                 spec->type = FORMAT_TYPE_PTR;
1173                 return fmt - start;
1174                 /* skip alnum */
1175
1176         case 'n':
1177                 spec->type = FORMAT_TYPE_NRCHARS;
1178                 return ++fmt - start;
1179
1180         case '%':
1181                 spec->type = FORMAT_TYPE_PERCENT_CHAR;
1182                 return ++fmt - start;
1183
1184         /* integer number formats - set up the flags and "break" */
1185         case 'o':
1186                 spec->base = 8;
1187                 break;
1188
1189         case 'x':
1190                 spec->flags |= SMALL;
1191
1192         case 'X':
1193                 spec->base = 16;
1194                 break;
1195
1196         case 'd':
1197         case 'i':
1198                 spec->flags |= SIGN;
1199         case 'u':
1200                 break;
1201
1202         default:
1203                 spec->type = FORMAT_TYPE_INVALID;
1204                 return fmt - start;
1205         }
1206
1207         if (spec->qualifier == 'L')
1208                 spec->type = FORMAT_TYPE_LONG_LONG;
1209         else if (spec->qualifier == 'l') {
1210                 if (spec->flags & SIGN)
1211                         spec->type = FORMAT_TYPE_LONG;
1212                 else
1213                         spec->type = FORMAT_TYPE_ULONG;
1214         } else if (TOLOWER(spec->qualifier) == 'z') {
1215                 spec->type = FORMAT_TYPE_SIZE_T;
1216         } else if (spec->qualifier == 't') {
1217                 spec->type = FORMAT_TYPE_PTRDIFF;
1218         } else if (spec->qualifier == 'H') {
1219                 if (spec->flags & SIGN)
1220                         spec->type = FORMAT_TYPE_BYTE;
1221                 else
1222                         spec->type = FORMAT_TYPE_UBYTE;
1223         } else if (spec->qualifier == 'h') {
1224                 if (spec->flags & SIGN)
1225                         spec->type = FORMAT_TYPE_SHORT;
1226                 else
1227                         spec->type = FORMAT_TYPE_USHORT;
1228         } else {
1229                 if (spec->flags & SIGN)
1230                         spec->type = FORMAT_TYPE_INT;
1231                 else
1232                         spec->type = FORMAT_TYPE_UINT;
1233         }
1234
1235         return ++fmt - start;
1236 }
1237
1238 /**
1239  * vsnprintf - Format a string and place it in a buffer
1240  * @buf: The buffer to place the result into
1241  * @size: The size of the buffer, including the trailing null space
1242  * @fmt: The format string to use
1243  * @args: Arguments for the format string
1244  *
1245  * This function follows C99 vsnprintf, but has some extensions:
1246  * %pS output the name of a text symbol with offset
1247  * %ps output the name of a text symbol without offset
1248  * %pF output the name of a function pointer with its offset
1249  * %pf output the name of a function pointer without its offset
1250  * %pR output the address range in a struct resource with decoded flags
1251  * %pr output the address range in a struct resource with raw flags
1252  * %pM output a 6-byte MAC address with colons
1253  * %pm output a 6-byte MAC address without colons
1254  * %pI4 print an IPv4 address without leading zeros
1255  * %pi4 print an IPv4 address with leading zeros
1256  * %pI6 print an IPv6 address with colons
1257  * %pi6 print an IPv6 address without colons
1258  * %pI6c print an IPv6 address as specified by
1259  *   http://tools.ietf.org/html/draft-ietf-6man-text-addr-representation-00
1260  * %pU[bBlL] print a UUID/GUID in big or little endian using lower or upper
1261  *   case.
1262  * %n is ignored
1263  *
1264  * The return value is the number of characters which would
1265  * be generated for the given input, excluding the trailing
1266  * '\0', as per ISO C99. If you want to have the exact
1267  * number of characters written into @buf as return value
1268  * (not including the trailing '\0'), use vscnprintf(). If the
1269  * return is greater than or equal to @size, the resulting
1270  * string is truncated.
1271  *
1272  * Call this function if you are already dealing with a va_list.
1273  * You probably want snprintf() instead.
1274  */
1275 int vsnprintf(char *buf, size_t size, const char *fmt, va_list args)
1276 {
1277         unsigned long long num;
1278         char *str, *end;
1279         struct printf_spec spec = {0};
1280
1281         /* Reject out-of-range values early.  Large positive sizes are
1282            used for unknown buffer sizes. */
1283         if (WARN_ON_ONCE((int) size < 0))
1284                 return 0;
1285
1286         str = buf;
1287         end = buf + size;
1288
1289         /* Make sure end is always >= buf */
1290         if (end < buf) {
1291                 end = ((void *)-1);
1292                 size = end - buf;
1293         }
1294
1295         while (*fmt) {
1296                 const char *old_fmt = fmt;
1297                 int read = format_decode(fmt, &spec);
1298
1299                 fmt += read;
1300
1301                 switch (spec.type) {
1302                 case FORMAT_TYPE_NONE: {
1303                         int copy = read;
1304                         if (str < end) {
1305                                 if (copy > end - str)
1306                                         copy = end - str;
1307                                 memcpy(str, old_fmt, copy);
1308                         }
1309                         str += read;
1310                         break;
1311                 }
1312
1313                 case FORMAT_TYPE_WIDTH:
1314                         spec.field_width = va_arg(args, int);
1315                         break;
1316
1317                 case FORMAT_TYPE_PRECISION:
1318                         spec.precision = va_arg(args, int);
1319                         break;
1320
1321                 case FORMAT_TYPE_CHAR: {
1322                         char c;
1323
1324                         if (!(spec.flags & LEFT)) {
1325                                 while (--spec.field_width > 0) {
1326                                         if (str < end)
1327                                                 *str = ' ';
1328                                         ++str;
1329
1330                                 }
1331                         }
1332                         c = (unsigned char) va_arg(args, int);
1333                         if (str < end)
1334                                 *str = c;
1335                         ++str;
1336                         while (--spec.field_width > 0) {
1337                                 if (str < end)
1338                                         *str = ' ';
1339                                 ++str;
1340                         }
1341                         break;
1342                 }
1343
1344                 case FORMAT_TYPE_STR:
1345                         str = string(str, end, va_arg(args, char *), spec);
1346                         break;
1347
1348                 case FORMAT_TYPE_PTR:
1349                         str = pointer(fmt+1, str, end, va_arg(args, void *),
1350                                       spec);
1351                         while (isalnum(*fmt))
1352                                 fmt++;
1353                         break;
1354
1355                 case FORMAT_TYPE_PERCENT_CHAR:
1356                         if (str < end)
1357                                 *str = '%';
1358                         ++str;
1359                         break;
1360
1361                 case FORMAT_TYPE_INVALID:
1362                         if (str < end)
1363                                 *str = '%';
1364                         ++str;
1365                         break;
1366
1367                 case FORMAT_TYPE_NRCHARS: {
1368                         u8 qualifier = spec.qualifier;
1369
1370                         if (qualifier == 'l') {
1371                                 long *ip = va_arg(args, long *);
1372                                 *ip = (str - buf);
1373                         } else if (TOLOWER(qualifier) == 'z') {
1374                                 size_t *ip = va_arg(args, size_t *);
1375                                 *ip = (str - buf);
1376                         } else {
1377                                 int *ip = va_arg(args, int *);
1378                                 *ip = (str - buf);
1379                         }
1380                         break;
1381                 }
1382
1383                 default:
1384                         switch (spec.type) {
1385                         case FORMAT_TYPE_LONG_LONG:
1386                                 num = va_arg(args, long long);
1387                                 break;
1388                         case FORMAT_TYPE_ULONG:
1389                                 num = va_arg(args, unsigned long);
1390                                 break;
1391                         case FORMAT_TYPE_LONG:
1392                                 num = va_arg(args, long);
1393                                 break;
1394                         case FORMAT_TYPE_SIZE_T:
1395                                 num = va_arg(args, size_t);
1396                                 break;
1397                         case FORMAT_TYPE_PTRDIFF:
1398                                 num = va_arg(args, ptrdiff_t);
1399                                 break;
1400                         case FORMAT_TYPE_UBYTE:
1401                                 num = (unsigned char) va_arg(args, int);
1402                                 break;
1403                         case FORMAT_TYPE_BYTE:
1404                                 num = (signed char) va_arg(args, int);
1405                                 break;
1406                         case FORMAT_TYPE_USHORT:
1407                                 num = (unsigned short) va_arg(args, int);
1408                                 break;
1409                         case FORMAT_TYPE_SHORT:
1410                                 num = (short) va_arg(args, int);
1411                                 break;
1412                         case FORMAT_TYPE_INT:
1413                                 num = (int) va_arg(args, int);
1414                                 break;
1415                         default:
1416                                 num = va_arg(args, unsigned int);
1417                         }
1418
1419                         str = number(str, end, num, spec);
1420                 }
1421         }
1422
1423         if (size > 0) {
1424                 if (str < end)
1425                         *str = '\0';
1426                 else
1427                         end[-1] = '\0';
1428         }
1429
1430         /* the trailing null byte doesn't count towards the total */
1431         return str-buf;
1432
1433 }
1434 EXPORT_SYMBOL(vsnprintf);
1435
1436 /**
1437  * vscnprintf - Format a string and place it in a buffer
1438  * @buf: The buffer to place the result into
1439  * @size: The size of the buffer, including the trailing null space
1440  * @fmt: The format string to use
1441  * @args: Arguments for the format string
1442  *
1443  * The return value is the number of characters which have been written into
1444  * the @buf not including the trailing '\0'. If @size is <= 0 the function
1445  * returns 0.
1446  *
1447  * Call this function if you are already dealing with a va_list.
1448  * You probably want scnprintf() instead.
1449  *
1450  * See the vsnprintf() documentation for format string extensions over C99.
1451  */
1452 int vscnprintf(char *buf, size_t size, const char *fmt, va_list args)
1453 {
1454         int i;
1455
1456         i = vsnprintf(buf, size, fmt, args);
1457
1458         return (i >= size) ? (size - 1) : i;
1459 }
1460 EXPORT_SYMBOL(vscnprintf);
1461
1462 /**
1463  * snprintf - Format a string and place it in a buffer
1464  * @buf: The buffer to place the result into
1465  * @size: The size of the buffer, including the trailing null space
1466  * @fmt: The format string to use
1467  * @...: Arguments for the format string
1468  *
1469  * The return value is the number of characters which would be
1470  * generated for the given input, excluding the trailing null,
1471  * as per ISO C99.  If the return is greater than or equal to
1472  * @size, the resulting string is truncated.
1473  *
1474  * See the vsnprintf() documentation for format string extensions over C99.
1475  */
1476 int snprintf(char *buf, size_t size, const char *fmt, ...)
1477 {
1478         va_list args;
1479         int i;
1480
1481         va_start(args, fmt);
1482         i = vsnprintf(buf, size, fmt, args);
1483         va_end(args);
1484
1485         return i;
1486 }
1487 EXPORT_SYMBOL(snprintf);
1488
1489 /**
1490  * scnprintf - Format a string and place it in a buffer
1491  * @buf: The buffer to place the result into
1492  * @size: The size of the buffer, including the trailing null space
1493  * @fmt: The format string to use
1494  * @...: Arguments for the format string
1495  *
1496  * The return value is the number of characters written into @buf not including
1497  * the trailing '\0'. If @size is <= 0 the function returns 0.
1498  */
1499
1500 int scnprintf(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 >= size) ? (size - 1) : i;
1510 }
1511 EXPORT_SYMBOL(scnprintf);
1512
1513 /**
1514  * vsprintf - Format a string and place it in a buffer
1515  * @buf: The buffer to place the result into
1516  * @fmt: The format string to use
1517  * @args: Arguments for the format string
1518  *
1519  * The function returns the number of characters written
1520  * into @buf. Use vsnprintf() or vscnprintf() in order to avoid
1521  * buffer overflows.
1522  *
1523  * Call this function if you are already dealing with a va_list.
1524  * You probably want sprintf() instead.
1525  *
1526  * See the vsnprintf() documentation for format string extensions over C99.
1527  */
1528 int vsprintf(char *buf, const char *fmt, va_list args)
1529 {
1530         return vsnprintf(buf, INT_MAX, fmt, args);
1531 }
1532 EXPORT_SYMBOL(vsprintf);
1533
1534 /**
1535  * sprintf - Format a string and place it in a buffer
1536  * @buf: The buffer to place the result into
1537  * @fmt: The format string to use
1538  * @...: Arguments for the format string
1539  *
1540  * The function returns the number of characters written
1541  * into @buf. Use snprintf() or scnprintf() in order to avoid
1542  * buffer overflows.
1543  *
1544  * See the vsnprintf() documentation for format string extensions over C99.
1545  */
1546 int sprintf(char *buf, const char *fmt, ...)
1547 {
1548         va_list args;
1549         int i;
1550
1551         va_start(args, fmt);
1552         i = vsnprintf(buf, INT_MAX, fmt, args);
1553         va_end(args);
1554
1555         return i;
1556 }
1557 EXPORT_SYMBOL(sprintf);
1558
1559 #ifdef CONFIG_BINARY_PRINTF
1560 /*
1561  * bprintf service:
1562  * vbin_printf() - VA arguments to binary data
1563  * bstr_printf() - Binary data to text string
1564  */
1565
1566 /**
1567  * vbin_printf - Parse a format string and place args' binary value in a buffer
1568  * @bin_buf: The buffer to place args' binary value
1569  * @size: The size of the buffer(by words(32bits), not characters)
1570  * @fmt: The format string to use
1571  * @args: Arguments for the format string
1572  *
1573  * The format follows C99 vsnprintf, except %n is ignored, and its argument
1574  * is skiped.
1575  *
1576  * The return value is the number of words(32bits) which would be generated for
1577  * the given input.
1578  *
1579  * NOTE:
1580  * If the return value is greater than @size, the resulting bin_buf is NOT
1581  * valid for bstr_printf().
1582  */
1583 int vbin_printf(u32 *bin_buf, size_t size, const char *fmt, va_list args)
1584 {
1585         struct printf_spec spec = {0};
1586         char *str, *end;
1587
1588         str = (char *)bin_buf;
1589         end = (char *)(bin_buf + size);
1590
1591 #define save_arg(type)                                                  \
1592 do {                                                                    \
1593         if (sizeof(type) == 8) {                                        \
1594                 unsigned long long value;                               \
1595                 str = PTR_ALIGN(str, sizeof(u32));                      \
1596                 value = va_arg(args, unsigned long long);               \
1597                 if (str + sizeof(type) <= end) {                        \
1598                         *(u32 *)str = *(u32 *)&value;                   \
1599                         *(u32 *)(str + 4) = *((u32 *)&value + 1);       \
1600                 }                                                       \
1601         } else {                                                        \
1602                 unsigned long value;                                    \
1603                 str = PTR_ALIGN(str, sizeof(type));                     \
1604                 value = va_arg(args, int);                              \
1605                 if (str + sizeof(type) <= end)                          \
1606                         *(typeof(type) *)str = (type)value;             \
1607         }                                                               \
1608         str += sizeof(type);                                            \
1609 } while (0)
1610
1611         while (*fmt) {
1612                 int read = format_decode(fmt, &spec);
1613
1614                 fmt += read;
1615
1616                 switch (spec.type) {
1617                 case FORMAT_TYPE_NONE:
1618                 case FORMAT_TYPE_INVALID:
1619                 case FORMAT_TYPE_PERCENT_CHAR:
1620                         break;
1621
1622                 case FORMAT_TYPE_WIDTH:
1623                 case FORMAT_TYPE_PRECISION:
1624                         save_arg(int);
1625                         break;
1626
1627                 case FORMAT_TYPE_CHAR:
1628                         save_arg(char);
1629                         break;
1630
1631                 case FORMAT_TYPE_STR: {
1632                         const char *save_str = va_arg(args, char *);
1633                         size_t len;
1634
1635                         if ((unsigned long)save_str > (unsigned long)-PAGE_SIZE
1636                                         || (unsigned long)save_str < PAGE_SIZE)
1637                                 save_str = "(null)";
1638                         len = strlen(save_str) + 1;
1639                         if (str + len < end)
1640                                 memcpy(str, save_str, len);
1641                         str += len;
1642                         break;
1643                 }
1644
1645                 case FORMAT_TYPE_PTR:
1646                         save_arg(void *);
1647                         /* skip all alphanumeric pointer suffixes */
1648                         while (isalnum(*fmt))
1649                                 fmt++;
1650                         break;
1651
1652                 case FORMAT_TYPE_NRCHARS: {
1653                         /* skip %n 's argument */
1654                         u8 qualifier = spec.qualifier;
1655                         void *skip_arg;
1656                         if (qualifier == 'l')
1657                                 skip_arg = va_arg(args, long *);
1658                         else if (TOLOWER(qualifier) == 'z')
1659                                 skip_arg = va_arg(args, size_t *);
1660                         else
1661                                 skip_arg = va_arg(args, int *);
1662                         break;
1663                 }
1664
1665                 default:
1666                         switch (spec.type) {
1667
1668                         case FORMAT_TYPE_LONG_LONG:
1669                                 save_arg(long long);
1670                                 break;
1671                         case FORMAT_TYPE_ULONG:
1672                         case FORMAT_TYPE_LONG:
1673                                 save_arg(unsigned long);
1674                                 break;
1675                         case FORMAT_TYPE_SIZE_T:
1676                                 save_arg(size_t);
1677                                 break;
1678                         case FORMAT_TYPE_PTRDIFF:
1679                                 save_arg(ptrdiff_t);
1680                                 break;
1681                         case FORMAT_TYPE_UBYTE:
1682                         case FORMAT_TYPE_BYTE:
1683                                 save_arg(char);
1684                                 break;
1685                         case FORMAT_TYPE_USHORT:
1686                         case FORMAT_TYPE_SHORT:
1687                                 save_arg(short);
1688                                 break;
1689                         default:
1690                                 save_arg(int);
1691                         }
1692                 }
1693         }
1694
1695         return (u32 *)(PTR_ALIGN(str, sizeof(u32))) - bin_buf;
1696 #undef save_arg
1697 }
1698 EXPORT_SYMBOL_GPL(vbin_printf);
1699
1700 /**
1701  * bstr_printf - Format a string from binary arguments and place it in a buffer
1702  * @buf: The buffer to place the result into
1703  * @size: The size of the buffer, including the trailing null space
1704  * @fmt: The format string to use
1705  * @bin_buf: Binary arguments for the format string
1706  *
1707  * This function like C99 vsnprintf, but the difference is that vsnprintf gets
1708  * arguments from stack, and bstr_printf gets arguments from @bin_buf which is
1709  * a binary buffer that generated by vbin_printf.
1710  *
1711  * The format follows C99 vsnprintf, but has some extensions:
1712  *  see vsnprintf comment for details.
1713  *
1714  * The return value is the number of characters which would
1715  * be generated for the given input, excluding the trailing
1716  * '\0', as per ISO C99. If you want to have the exact
1717  * number of characters written into @buf as return value
1718  * (not including the trailing '\0'), use vscnprintf(). If the
1719  * return is greater than or equal to @size, the resulting
1720  * string is truncated.
1721  */
1722 int bstr_printf(char *buf, size_t size, const char *fmt, const u32 *bin_buf)
1723 {
1724         struct printf_spec spec = {0};
1725         char *str, *end;
1726         const char *args = (const char *)bin_buf;
1727
1728         if (WARN_ON_ONCE((int) size < 0))
1729                 return 0;
1730
1731         str = buf;
1732         end = buf + size;
1733
1734 #define get_arg(type)                                                   \
1735 ({                                                                      \
1736         typeof(type) value;                                             \
1737         if (sizeof(type) == 8) {                                        \
1738                 args = PTR_ALIGN(args, sizeof(u32));                    \
1739                 *(u32 *)&value = *(u32 *)args;                          \
1740                 *((u32 *)&value + 1) = *(u32 *)(args + 4);              \
1741         } else {                                                        \
1742                 args = PTR_ALIGN(args, sizeof(type));                   \
1743                 value = *(typeof(type) *)args;                          \
1744         }                                                               \
1745         args += sizeof(type);                                           \
1746         value;                                                          \
1747 })
1748
1749         /* Make sure end is always >= buf */
1750         if (end < buf) {
1751                 end = ((void *)-1);
1752                 size = end - buf;
1753         }
1754
1755         while (*fmt) {
1756                 const char *old_fmt = fmt;
1757                 int read = format_decode(fmt, &spec);
1758
1759                 fmt += read;
1760
1761                 switch (spec.type) {
1762                 case FORMAT_TYPE_NONE: {
1763                         int copy = read;
1764                         if (str < end) {
1765                                 if (copy > end - str)
1766                                         copy = end - str;
1767                                 memcpy(str, old_fmt, copy);
1768                         }
1769                         str += read;
1770                         break;
1771                 }
1772
1773                 case FORMAT_TYPE_WIDTH:
1774                         spec.field_width = get_arg(int);
1775                         break;
1776
1777                 case FORMAT_TYPE_PRECISION:
1778                         spec.precision = get_arg(int);
1779                         break;
1780
1781                 case FORMAT_TYPE_CHAR: {
1782                         char c;
1783
1784                         if (!(spec.flags & LEFT)) {
1785                                 while (--spec.field_width > 0) {
1786                                         if (str < end)
1787                                                 *str = ' ';
1788                                         ++str;
1789                                 }
1790                         }
1791                         c = (unsigned char) get_arg(char);
1792                         if (str < end)
1793                                 *str = c;
1794                         ++str;
1795                         while (--spec.field_width > 0) {
1796                                 if (str < end)
1797                                         *str = ' ';
1798                                 ++str;
1799                         }
1800                         break;
1801                 }
1802
1803                 case FORMAT_TYPE_STR: {
1804                         const char *str_arg = args;
1805                         args += strlen(str_arg) + 1;
1806                         str = string(str, end, (char *)str_arg, spec);
1807                         break;
1808                 }
1809
1810                 case FORMAT_TYPE_PTR:
1811                         str = pointer(fmt+1, str, end, get_arg(void *), spec);
1812                         while (isalnum(*fmt))
1813                                 fmt++;
1814                         break;
1815
1816                 case FORMAT_TYPE_PERCENT_CHAR:
1817                 case FORMAT_TYPE_INVALID:
1818                         if (str < end)
1819                                 *str = '%';
1820                         ++str;
1821                         break;
1822
1823                 case FORMAT_TYPE_NRCHARS:
1824                         /* skip */
1825                         break;
1826
1827                 default: {
1828                         unsigned long long num;
1829
1830                         switch (spec.type) {
1831
1832                         case FORMAT_TYPE_LONG_LONG:
1833                                 num = get_arg(long long);
1834                                 break;
1835                         case FORMAT_TYPE_ULONG:
1836                         case FORMAT_TYPE_LONG:
1837                                 num = get_arg(unsigned long);
1838                                 break;
1839                         case FORMAT_TYPE_SIZE_T:
1840                                 num = get_arg(size_t);
1841                                 break;
1842                         case FORMAT_TYPE_PTRDIFF:
1843                                 num = get_arg(ptrdiff_t);
1844                                 break;
1845                         case FORMAT_TYPE_UBYTE:
1846                                 num = get_arg(unsigned char);
1847                                 break;
1848                         case FORMAT_TYPE_BYTE:
1849                                 num = get_arg(signed char);
1850                                 break;
1851                         case FORMAT_TYPE_USHORT:
1852                                 num = get_arg(unsigned short);
1853                                 break;
1854                         case FORMAT_TYPE_SHORT:
1855                                 num = get_arg(short);
1856                                 break;
1857                         case FORMAT_TYPE_UINT:
1858                                 num = get_arg(unsigned int);
1859                                 break;
1860                         default:
1861                                 num = get_arg(int);
1862                         }
1863
1864                         str = number(str, end, num, spec);
1865                 } /* default: */
1866                 } /* switch(spec.type) */
1867         } /* while(*fmt) */
1868
1869         if (size > 0) {
1870                 if (str < end)
1871                         *str = '\0';
1872                 else
1873                         end[-1] = '\0';
1874         }
1875
1876 #undef get_arg
1877
1878         /* the trailing null byte doesn't count towards the total */
1879         return str - buf;
1880 }
1881 EXPORT_SYMBOL_GPL(bstr_printf);
1882
1883 /**
1884  * bprintf - Parse a format string and place args' binary value in a buffer
1885  * @bin_buf: The buffer to place args' binary value
1886  * @size: The size of the buffer(by words(32bits), not characters)
1887  * @fmt: The format string to use
1888  * @...: Arguments for the format string
1889  *
1890  * The function returns the number of words(u32) written
1891  * into @bin_buf.
1892  */
1893 int bprintf(u32 *bin_buf, size_t size, const char *fmt, ...)
1894 {
1895         va_list args;
1896         int ret;
1897
1898         va_start(args, fmt);
1899         ret = vbin_printf(bin_buf, size, fmt, args);
1900         va_end(args);
1901
1902         return ret;
1903 }
1904 EXPORT_SYMBOL_GPL(bprintf);
1905
1906 #endif /* CONFIG_BINARY_PRINTF */
1907
1908 /**
1909  * vsscanf - Unformat a buffer into a list of arguments
1910  * @buf:        input buffer
1911  * @fmt:        format of buffer
1912  * @args:       arguments
1913  */
1914 int vsscanf(const char *buf, const char *fmt, va_list args)
1915 {
1916         const char *str = buf;
1917         char *next;
1918         char digit;
1919         int num = 0;
1920         u8 qualifier;
1921         u8 base;
1922         s16 field_width;
1923         bool is_sign;
1924
1925         while (*fmt && *str) {
1926                 /* skip any white space in format */
1927                 /* white space in format matchs any amount of
1928                  * white space, including none, in the input.
1929                  */
1930                 if (isspace(*fmt)) {
1931                         fmt = skip_spaces(++fmt);
1932                         str = skip_spaces(str);
1933                 }
1934
1935                 /* anything that is not a conversion must match exactly */
1936                 if (*fmt != '%' && *fmt) {
1937                         if (*fmt++ != *str++)
1938                                 break;
1939                         continue;
1940                 }
1941
1942                 if (!*fmt)
1943                         break;
1944                 ++fmt;
1945
1946                 /* skip this conversion.
1947                  * advance both strings to next white space
1948                  */
1949                 if (*fmt == '*') {
1950                         while (!isspace(*fmt) && *fmt != '%' && *fmt)
1951                                 fmt++;
1952                         while (!isspace(*str) && *str)
1953                                 str++;
1954                         continue;
1955                 }
1956
1957                 /* get field width */
1958                 field_width = -1;
1959                 if (isdigit(*fmt))
1960                         field_width = skip_atoi(&fmt);
1961
1962                 /* get conversion qualifier */
1963                 qualifier = -1;
1964                 if (*fmt == 'h' || TOLOWER(*fmt) == 'l' ||
1965                     TOLOWER(*fmt) == 'z') {
1966                         qualifier = *fmt++;
1967                         if (unlikely(qualifier == *fmt)) {
1968                                 if (qualifier == 'h') {
1969                                         qualifier = 'H';
1970                                         fmt++;
1971                                 } else if (qualifier == 'l') {
1972                                         qualifier = 'L';
1973                                         fmt++;
1974                                 }
1975                         }
1976                 }
1977
1978                 if (!*fmt || !*str)
1979                         break;
1980
1981                 base = 10;
1982                 is_sign = 0;
1983
1984                 switch (*fmt++) {
1985                 case 'c':
1986                 {
1987                         char *s = (char *)va_arg(args, char*);
1988                         if (field_width == -1)
1989                                 field_width = 1;
1990                         do {
1991                                 *s++ = *str++;
1992                         } while (--field_width > 0 && *str);
1993                         num++;
1994                 }
1995                 continue;
1996                 case 's':
1997                 {
1998                         char *s = (char *)va_arg(args, char *);
1999                         if (field_width == -1)
2000                                 field_width = SHRT_MAX;
2001                         /* first, skip leading white space in buffer */
2002                         str = skip_spaces(str);
2003
2004                         /* now copy until next white space */
2005                         while (*str && !isspace(*str) && field_width--)
2006                                 *s++ = *str++;
2007                         *s = '\0';
2008                         num++;
2009                 }
2010                 continue;
2011                 case 'n':
2012                         /* return number of characters read so far */
2013                 {
2014                         int *i = (int *)va_arg(args, int*);
2015                         *i = str - buf;
2016                 }
2017                 continue;
2018                 case 'o':
2019                         base = 8;
2020                         break;
2021                 case 'x':
2022                 case 'X':
2023                         base = 16;
2024                         break;
2025                 case 'i':
2026                         base = 0;
2027                 case 'd':
2028                         is_sign = 1;
2029                 case 'u':
2030                         break;
2031                 case '%':
2032                         /* looking for '%' in str */
2033                         if (*str++ != '%')
2034                                 return num;
2035                         continue;
2036                 default:
2037                         /* invalid format; stop here */
2038                         return num;
2039                 }
2040
2041                 /* have some sort of integer conversion.
2042                  * first, skip white space in buffer.
2043                  */
2044                 str = skip_spaces(str);
2045
2046                 digit = *str;
2047                 if (is_sign && digit == '-')
2048                         digit = *(str + 1);
2049
2050                 if (!digit
2051                     || (base == 16 && !isxdigit(digit))
2052                     || (base == 10 && !isdigit(digit))
2053                     || (base == 8 && (!isdigit(digit) || digit > '7'))
2054                     || (base == 0 && !isdigit(digit)))
2055                         break;
2056
2057                 switch (qualifier) {
2058                 case 'H':       /* that's 'hh' in format */
2059                         if (is_sign) {
2060                                 signed char *s = (signed char *)va_arg(args, signed char *);
2061                                 *s = (signed char)simple_strtol(str, &next, base);
2062                         } else {
2063                                 unsigned char *s = (unsigned char *)va_arg(args, unsigned char *);
2064                                 *s = (unsigned char)simple_strtoul(str, &next, base);
2065                         }
2066                         break;
2067                 case 'h':
2068                         if (is_sign) {
2069                                 short *s = (short *)va_arg(args, short *);
2070                                 *s = (short)simple_strtol(str, &next, base);
2071                         } else {
2072                                 unsigned short *s = (unsigned short *)va_arg(args, unsigned short *);
2073                                 *s = (unsigned short)simple_strtoul(str, &next, base);
2074                         }
2075                         break;
2076                 case 'l':
2077                         if (is_sign) {
2078                                 long *l = (long *)va_arg(args, long *);
2079                                 *l = simple_strtol(str, &next, base);
2080                         } else {
2081                                 unsigned long *l = (unsigned long *)va_arg(args, unsigned long *);
2082                                 *l = simple_strtoul(str, &next, base);
2083                         }
2084                         break;
2085                 case 'L':
2086                         if (is_sign) {
2087                                 long long *l = (long long *)va_arg(args, long long *);
2088                                 *l = simple_strtoll(str, &next, base);
2089                         } else {
2090                                 unsigned long long *l = (unsigned long long *)va_arg(args, unsigned long long *);
2091                                 *l = simple_strtoull(str, &next, base);
2092                         }
2093                         break;
2094                 case 'Z':
2095                 case 'z':
2096                 {
2097                         size_t *s = (size_t *)va_arg(args, size_t *);
2098                         *s = (size_t)simple_strtoul(str, &next, base);
2099                 }
2100                 break;
2101                 default:
2102                         if (is_sign) {
2103                                 int *i = (int *)va_arg(args, int *);
2104                                 *i = (int)simple_strtol(str, &next, base);
2105                         } else {
2106                                 unsigned int *i = (unsigned int *)va_arg(args, unsigned int*);
2107                                 *i = (unsigned int)simple_strtoul(str, &next, base);
2108                         }
2109                         break;
2110                 }
2111                 num++;
2112
2113                 if (!next)
2114                         break;
2115                 str = next;
2116         }
2117
2118         /*
2119          * Now we've come all the way through so either the input string or the
2120          * format ended. In the former case, there can be a %n at the current
2121          * position in the format that needs to be filled.
2122          */
2123         if (*fmt == '%' && *(fmt + 1) == 'n') {
2124                 int *p = (int *)va_arg(args, int *);
2125                 *p = str - buf;
2126         }
2127
2128         return num;
2129 }
2130 EXPORT_SYMBOL(vsscanf);
2131
2132 /**
2133  * sscanf - Unformat a buffer into a list of arguments
2134  * @buf:        input buffer
2135  * @fmt:        formatting of buffer
2136  * @...:        resulting arguments
2137  */
2138 int sscanf(const char *buf, const char *fmt, ...)
2139 {
2140         va_list args;
2141         int i;
2142
2143         va_start(args, fmt);
2144         i = vsscanf(buf, fmt, args);
2145         va_end(args);
2146
2147         return i;
2148 }
2149 EXPORT_SYMBOL(sscanf);