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 int skip_atoi(const char **s)
 271 {
 272         int i = 0;
 273
 274         while (isdigit(**s))
 275                 i = i*10 + *((*s)++) - '0';
 276
 277         return i;
 278 }
 279
 280 /* Decimal conversion is by far the most typical, and is used
 281  * for /proc and /sys data. This directly impacts e.g. top performance
 282  * with many processes running. We optimize it for speed
 283  * using code from
 284  * http://www.cs.uiowa.edu/~jones/bcd/decimal.html
 285  * (with permission from the author, Douglas W. Jones). */
 286
 287 /* Formats correctly any integer in [0,99999].
 288  * Outputs from one to five digits depending on input.
 289  * On i386 gcc 4.1.2 -O2: ~250 bytes of code. */
 290 static char *put_dec_trunc(char *buf, unsigned q)
 291 {
 292         unsigned d3, d2, d1, d0;
 293         d1 = (q>>4) & 0xf;
 294         d2 = (q>>8) & 0xf;
 295         d3 = (q>>12);
 296
 297         d0 = 6*(d3 + d2 + d1) + (q & 0xf);
 298         q = (d0 * 0xcd) >> 11;
 299         d0 = d0 - 10*q;
 300         *buf++ = d0 + '0'; /* least significant digit */
 301         d1 = q + 9*d3 + 5*d2 + d1;
 302         if (d1 != 0) {
 303                 q = (d1 * 0xcd) >> 11;
 304                 d1 = d1 - 10*q;
 305                 *buf++ = d1 + '0'; /* next digit */
 306
 307                 d2 = q + 2*d2;
 308                 if ((d2 != 0) || (d3 != 0)) {
 309                         q = (d2 * 0xd) >> 7;
 310                         d2 = d2 - 10*q;
 311                         *buf++ = d2 + '0'; /* next digit */
 312
 313                         d3 = q + 4*d3;
 314                         if (d3 != 0) {
 315                                 q = (d3 * 0xcd) >> 11;
 316                                 d3 = d3 - 10*q;
 317                                 *buf++ = d3 + '0';  /* next digit */
 318                                 if (q != 0)
 319                                         *buf++ = q + '0'; /* most sign. digit */
 320                         }
 321                 }
 322         }
 323
 324         return buf;
 325 }
 326 /* Same with if's removed. Always emits five digits */
 327 static char *put_dec_full(char *buf, unsigned q)
 328 {
 329         /* BTW, if q is in [0,9999], 8-bit ints will be enough, */
 330         /* but anyway, gcc produces better code with full-sized ints */
 331         unsigned d3, d2, d1, d0;
 332         d1 = (q>>4) & 0xf;
 333         d2 = (q>>8) & 0xf;
 334         d3 = (q>>12);
 335
 336         /*
 337          * Possible ways to approx. divide by 10
 338          * gcc -O2 replaces multiply with shifts and adds
 339          * (x * 0xcd) >> 11: 11001101 - shorter code than * 0x67 (on i386)
 340          * (x * 0x67) >> 10:  1100111
 341          * (x * 0x34) >> 9:    110100 - same
 342          * (x * 0x1a) >> 8:     11010 - same
 343          * (x * 0x0d) >> 7:      1101 - same, shortest code (on i386)
 344          */
 345         d0 = 6*(d3 + d2 + d1) + (q & 0xf);
 346         q = (d0 * 0xcd) >> 11;
 347         d0 = d0 - 10*q;
 348         *buf++ = d0 + '0';
 349         d1 = q + 9*d3 + 5*d2 + d1;
 350                 q = (d1 * 0xcd) >> 11;
 351                 d1 = d1 - 10*q;
 352                 *buf++ = d1 + '0';
 353
 354                 d2 = q + 2*d2;
 355                         q = (d2 * 0xd) >> 7;
 356                         d2 = d2 - 10*q;
 357                         *buf++ = d2 + '0';
 358
 359                         d3 = q + 4*d3;
 360                                 q = (d3 * 0xcd) >> 11; /* - shorter code */
 361                                 /* q = (d3 * 0x67) >> 10; - would also work */
 362                                 d3 = d3 - 10*q;
 363                                 *buf++ = d3 + '0';
 364                                         *buf++ = q + '0';
 365
 366         return buf;
 367 }
 368 /* No inlining helps gcc to use registers better */
 369 static noinline char *put_dec(char *buf, unsigned long long num)
 370 {
 371         while (1) {
 372                 unsigned rem;
 373                 if (num < 100000)
 374                         return put_dec_trunc(buf, num);
 375                 rem = do_div(num, 100000);
 376                 buf = put_dec_full(buf, rem);
 377         }
 378 }
 379
 380 #define ZEROPAD 1               /* pad with zero */
 381 #define SIGN    2               /* unsigned/signed long */
 382 #define PLUS    4               /* show plus */
 383 #define SPACE   8               /* space if plus */
 384 #define LEFT    16              /* left justified */
 385 #define SMALL   32              /* use lowercase in hex (must be 32 == 0x20) */
 386 #define SPECIAL 64              /* prefix hex with "0x", octal with "0" */
 387
 388 enum format_type {
 389         FORMAT_TYPE_NONE, /* Just a string part */
 390         FORMAT_TYPE_WIDTH,
 391         FORMAT_TYPE_PRECISION,
 392         FORMAT_TYPE_CHAR,
 393         FORMAT_TYPE_STR,
 394         FORMAT_TYPE_PTR,
 395         FORMAT_TYPE_PERCENT_CHAR,
 396         FORMAT_TYPE_INVALID,
 397         FORMAT_TYPE_LONG_LONG,
 398         FORMAT_TYPE_ULONG,
 399         FORMAT_TYPE_LONG,
 400         FORMAT_TYPE_UBYTE,
 401         FORMAT_TYPE_BYTE,
 402         FORMAT_TYPE_USHORT,
 403         FORMAT_TYPE_SHORT,
 404         FORMAT_TYPE_UINT,
 405         FORMAT_TYPE_INT,
 406         FORMAT_TYPE_NRCHARS,
 407         FORMAT_TYPE_SIZE_T,
 408         FORMAT_TYPE_PTRDIFF
 409 };
 410
 411 struct printf_spec {
 412         u8      type;           /* format_type enum */
 413         u8      flags;          /* flags to number() */
 414         u8      base;           /* number base, 8, 10 or 16 only */
 415         u8      qualifier;      /* number qualifier, one of 'hHlLtzZ' */
 416         s16     field_width;    /* width of output field */
 417         s16     precision;      /* # of digits/chars */
 418 };
 419
 420 static char *number(char *buf, char *end, unsigned long long num,
 421                         struct printf_spec spec)
 422 {
 423         /* we are called with base 8, 10 or 16, only, thus don't need "G..."  */
 424         static const char digits[16] = "0123456789ABCDEF"; /* "GHIJKLMNOPQRSTUVWXYZ"; */
 425
 426         char tmp[66];
 427         char sign;
 428         char locase;
 429         int need_pfx = ((spec.flags & SPECIAL) && spec.base != 10);
 430         int i;
 431
 432         /* locase = 0 or 0x20. ORing digits or letters with 'locase'
 433          * produces same digits or (maybe lowercased) letters */
 434         locase = (spec.flags & SMALL);
 435         if (spec.flags & LEFT)
 436                 spec.flags &= ~ZEROPAD;
 437         sign = 0;
 438         if (spec.flags & SIGN) {
 439                 if ((signed long long)num < 0) {
 440                         sign = '-';
 441                         num = -(signed long long)num;
 442                         spec.field_width--;
 443                 } else if (spec.flags & PLUS) {
 444                         sign = '+';
 445                         spec.field_width--;
 446                 } else if (spec.flags & SPACE) {
 447                         sign = ' ';
 448                         spec.field_width--;
 449                 }
 450         }
 451         if (need_pfx) {
 452                 spec.field_width--;
 453                 if (spec.base == 16)
 454                         spec.field_width--;
 455         }
 456
 457         /* generate full string in tmp[], in reverse order */
 458         i = 0;
 459         if (num == 0)
 460                 tmp[i++] = '0';
 461         /* Generic code, for any base:
 462         else do {
 463                 tmp[i++] = (digits[do_div(num,base)] | locase);
 464         } while (num != 0);
 465         */
 466         else if (spec.base != 10) { /* 8 or 16 */
 467                 int mask = spec.base - 1;
 468                 int shift = 3;
 469
 470                 if (spec.base == 16)
 471                         shift = 4;
 472                 do {
 473                         tmp[i++] = (digits[((unsigned char)num) & mask] | locase);
 474                         num >>= shift;
 475                 } while (num);
 476         } else { /* base 10 */
 477                 i = put_dec(tmp, num) - tmp;
 478         }
 479
 480         /* printing 100 using %2d gives "100", not "00" */
 481         if (i > spec.precision)
 482                 spec.precision = i;
 483         /* leading space padding */
 484         spec.field_width -= spec.precision;
 485         if (!(spec.flags & (ZEROPAD+LEFT))) {
 486                 while (--spec.field_width >= 0) {
 487                         if (buf < end)
 488                                 *buf = ' ';
 489                         ++buf;
 490                 }
 491         }
 492         /* sign */
 493         if (sign) {
 494                 if (buf < end)
 495                         *buf = sign;
 496                 ++buf;
 497         }
 498         /* "0x" / "0" prefix */
 499         if (need_pfx) {
 500                 if (buf < end)
 501                         *buf = '0';
 502                 ++buf;
 503                 if (spec.base == 16) {
 504                         if (buf < end)
 505                                 *buf = ('X' | locase);
 506                         ++buf;
 507                 }
 508         }
 509         /* zero or space padding */
 510         if (!(spec.flags & LEFT)) {
 511                 char c = (spec.flags & ZEROPAD) ? '0' : ' ';
 512                 while (--spec.field_width >= 0) {
 513                         if (buf < end)
 514                                 *buf = c;
 515                         ++buf;
 516                 }
 517         }
 518         /* hmm even more zero padding? */
 519         while (i <= --spec.precision) {
 520                 if (buf < end)
 521                         *buf = '0';
 522                 ++buf;
 523         }
 524         /* actual digits of result */
 525         while (--i >= 0) {
 526                 if (buf < end)
 527                         *buf = tmp[i];
 528                 ++buf;
 529         }
 530         /* trailing space padding */
 531         while (--spec.field_width >= 0) {
 532                 if (buf < end)
 533                         *buf = ' ';
 534                 ++buf;
 535         }
 536
 537         return buf;
 538 }
 539
 540 static char *string(char *buf, char *end, const char *s, struct printf_spec spec)
 541 {
 542         int len, i;
 543
 544         if ((unsigned long)s < PAGE_SIZE)
 545                 s = "(null)";
 546
 547         len = strnlen(s, spec.precision);
 548
 549         if (!(spec.flags & LEFT)) {
 550                 while (len < spec.field_width--) {
 551                         if (buf < end)
 552                                 *buf = ' ';
 553                         ++buf;
 554                 }
 555         }
 556         for (i = 0; i < len; ++i) {
 557                 if (buf < end)
 558                         *buf = *s;
 559                 ++buf; ++s;
 560         }
 561         while (len < spec.field_width--) {
 562                 if (buf < end)
 563                         *buf = ' ';
 564                 ++buf;
 565         }
 566
 567         return buf;
 568 }
 569
 570 static char *symbol_string(char *buf, char *end, void *ptr,
 571                                 struct printf_spec spec, char ext)
 572 {
 573         unsigned long value = (unsigned long) ptr;
 574 #ifdef CONFIG_KALLSYMS
 575         char sym[KSYM_SYMBOL_LEN];
 576         if (ext != 'f' && ext != 's')
 577                 sprint_symbol(sym, value);
 578         else
 579                 kallsyms_lookup(value, NULL, NULL, NULL, sym);
 580
 581         return string(buf, end, sym, spec);
 582 #else
 583         spec.field_width = 2 * sizeof(void *);
 584         spec.flags |= SPECIAL | SMALL | ZEROPAD;
 585         spec.base = 16;
 586
 587         return number(buf, end, value, spec);
 588 #endif
 589 }
 590
 591 static char *resource_string(char *buf, char *end, struct resource *res,
 592                                 struct printf_spec spec, const char *fmt)
 593 {
 594 #ifndef IO_RSRC_PRINTK_SIZE
 595 #define IO_RSRC_PRINTK_SIZE     6
 596 #endif
 597
 598 #ifndef MEM_RSRC_PRINTK_SIZE
 599 #define MEM_RSRC_PRINTK_SIZE    10
 600 #endif
 601         static const struct printf_spec io_spec = {
 602                 .base = 16,
 603                 .field_width = IO_RSRC_PRINTK_SIZE,
 604                 .precision = -1,
 605                 .flags = SPECIAL | SMALL | ZEROPAD,
 606         };
 607         static const struct printf_spec mem_spec = {
 608                 .base = 16,
 609                 .field_width = MEM_RSRC_PRINTK_SIZE,
 610                 .precision = -1,
 611                 .flags = SPECIAL | SMALL | ZEROPAD,
 612         };
 613         static const struct printf_spec bus_spec = {
 614                 .base = 16,
 615                 .field_width = 2,
 616                 .precision = -1,
 617                 .flags = SMALL | ZEROPAD,
 618         };
 619         static const struct printf_spec dec_spec = {
 620                 .base = 10,
 621                 .precision = -1,
 622                 .flags = 0,
 623         };
 624         static const struct printf_spec str_spec = {
 625                 .field_width = -1,
 626                 .precision = 10,
 627                 .flags = LEFT,
 628         };
 629         static const struct printf_spec flag_spec = {
 630                 .base = 16,
 631                 .precision = -1,
 632                 .flags = SPECIAL | SMALL,
 633         };
 634
 635         /* 32-bit res (sizeof==4): 10 chars in dec, 10 in hex ("0x" + 8)
 636          * 64-bit res (sizeof==8): 20 chars in dec, 18 in hex ("0x" + 16) */
 637 #define RSRC_BUF_SIZE           ((2 * sizeof(resource_size_t)) + 4)
 638 #define FLAG_BUF_SIZE           (2 * sizeof(res->flags))
 639 #define DECODED_BUF_SIZE        sizeof("[mem - 64bit pref window disabled]")
 640 #define RAW_BUF_SIZE            sizeof("[mem - flags 0x]")
 641         char sym[max(2*RSRC_BUF_SIZE + DECODED_BUF_SIZE,
 642                      2*RSRC_BUF_SIZE + FLAG_BUF_SIZE + RAW_BUF_SIZE)];
 643
 644         char *p = sym, *pend = sym + sizeof(sym);
 645         int decode = (fmt[0] == 'R') ? 1 : 0;
 646         const struct printf_spec *specp;
 647
 648         *p++ = '[';
 649         if (res->flags & IORESOURCE_IO) {
 650                 p = string(p, pend, "io  ", str_spec);
 651                 specp = &io_spec;
 652         } else if (res->flags & IORESOURCE_MEM) {
 653                 p = string(p, pend, "mem ", str_spec);
 654                 specp = &mem_spec;
 655         } else if (res->flags & IORESOURCE_IRQ) {
 656                 p = string(p, pend, "irq ", str_spec);
 657                 specp = &dec_spec;
 658         } else if (res->flags & IORESOURCE_DMA) {
 659                 p = string(p, pend, "dma ", str_spec);
 660                 specp = &dec_spec;
 661         } else if (res->flags & IORESOURCE_BUS) {
 662                 p = string(p, pend, "bus ", str_spec);
 663                 specp = &bus_spec;
 664         } else {
 665                 p = string(p, pend, "??? ", str_spec);
 666                 specp = &mem_spec;
 667                 decode = 0;
 668         }
 669         p = number(p, pend, res->start, *specp);
 670         if (res->start != res->end) {
 671                 *p++ = '-';
 672                 p = number(p, pend, res->end, *specp);
 673         }
 674         if (decode) {
 675                 if (res->flags & IORESOURCE_MEM_64)
 676                         p = string(p, pend, " 64bit", str_spec);
 677                 if (res->flags & IORESOURCE_PREFETCH)
 678                         p = string(p, pend, " pref", str_spec);
 679                 if (res->flags & IORESOURCE_WINDOW)
 680                         p = string(p, pend, " window", str_spec);
 681                 if (res->flags & IORESOURCE_DISABLED)
 682                         p = string(p, pend, " disabled", str_spec);
 683         } else {
 684                 p = string(p, pend, " flags ", str_spec);
 685                 p = number(p, pend, res->flags, flag_spec);
 686         }
 687         *p++ = ']';
 688         *p = '\0';
 689
 690         return string(buf, end, sym, spec);
 691 }
 692
 693 static char *mac_address_string(char *buf, char *end, u8 *addr,
 694                                 struct printf_spec spec, const char *fmt)
 695 {
 696         char mac_addr[sizeof("xx:xx:xx:xx:xx:xx")];
 697         char *p = mac_addr;
 698         int i;
 699         char separator;
 700
 701         if (fmt[1] == 'F') {            /* FDDI canonical format */
 702                 separator = '-';
 703         } else {
 704                 separator = ':';
 705         }
 706
 707         for (i = 0; i < 6; i++) {
 708                 p = pack_hex_byte(p, addr[i]);
 709                 if (fmt[0] == 'M' && i != 5)
 710                         *p++ = separator;
 711         }
 712         *p = '\0';
 713
 714         return string(buf, end, mac_addr, spec);
 715 }
 716
 717 static char *ip4_string(char *p, const u8 *addr, const char *fmt)
 718 {
 719         int i;
 720         bool leading_zeros = (fmt[0] == 'i');
 721         int index;
 722         int step;
 723
 724         switch (fmt[2]) {
 725         case 'h':
 726 #ifdef __BIG_ENDIAN
 727                 index = 0;
 728                 step = 1;
 729 #else
 730                 index = 3;
 731                 step = -1;
 732 #endif
 733                 break;
 734         case 'l':
 735                 index = 3;
 736                 step = -1;
 737                 break;
 738         case 'n':
 739         case 'b':
 740         default:
 741                 index = 0;
 742                 step = 1;
 743                 break;
 744         }
 745         for (i = 0; i < 4; i++) {
 746                 char temp[3];   /* hold each IP quad in reverse order */
 747                 int digits = put_dec_trunc(temp, addr[index]) - temp;
 748                 if (leading_zeros) {
 749                         if (digits < 3)
 750                                 *p++ = '0';
 751                         if (digits < 2)
 752                                 *p++ = '0';
 753                 }
 754                 /* reverse the digits in the quad */
 755                 while (digits--)
 756                         *p++ = temp[digits];
 757                 if (i < 3)
 758                         *p++ = '.';
 759                 index += step;
 760         }
 761         *p = '\0';
 762
 763         return p;
 764 }
 765
 766 static char *ip6_compressed_string(char *p, const char *addr)
 767 {
 768         int i, j, range;
 769         unsigned char zerolength[8];
 770         int longest = 1;
 771         int colonpos = -1;
 772         u16 word;
 773         u8 hi, lo;
 774         bool needcolon = false;
 775         bool useIPv4;
 776         struct in6_addr in6;
 777
 778         memcpy(&in6, addr, sizeof(struct in6_addr));
 779
 780         useIPv4 = ipv6_addr_v4mapped(&in6) || ipv6_addr_is_isatap(&in6);
 781
 782         memset(zerolength, 0, sizeof(zerolength));
 783
 784         if (useIPv4)
 785                 range = 6;
 786         else
 787                 range = 8;
 788
 789         /* find position of longest 0 run */
 790         for (i = 0; i < range; i++) {
 791                 for (j = i; j < range; j++) {
 792                         if (in6.s6_addr16[j] != 0)
 793                                 break;
 794                         zerolength[i]++;
 795                 }
 796         }
 797         for (i = 0; i < range; i++) {
 798                 if (zerolength[i] > longest) {
 799                         longest = zerolength[i];
 800                         colonpos = i;
 801                 }
 802         }
 803
 804         /* emit address */
 805         for (i = 0; i < range; i++) {
 806                 if (i == colonpos) {
 807                         if (needcolon || i == 0)
 808                                 *p++ = ':';
 809                         *p++ = ':';
 810                         needcolon = false;
 811                         i += longest - 1;
 812                         continue;
 813                 }
 814                 if (needcolon) {
 815                         *p++ = ':';
 816                         needcolon = false;
 817                 }
 818                 /* hex u16 without leading 0s */
 819                 word = ntohs(in6.s6_addr16[i]);
 820                 hi = word >> 8;
 821                 lo = word & 0xff;
 822                 if (hi) {
 823                         if (hi > 0x0f)
 824                                 p = pack_hex_byte(p, hi);
 825                         else
 826                                 *p++ = hex_asc_lo(hi);
 827                         p = pack_hex_byte(p, lo);
 828                 }
 829                 else if (lo > 0x0f)
 830                         p = pack_hex_byte(p, lo);
 831                 else
 832                         *p++ = hex_asc_lo(lo);
 833                 needcolon = true;
 834         }
 835
 836         if (useIPv4) {
 837                 if (needcolon)
 838                         *p++ = ':';
 839                 p = ip4_string(p, &in6.s6_addr[12], "I4");
 840         }
 841         *p = '\0';
 842
 843         return p;
 844 }
 845
 846 static char *ip6_string(char *p, const char *addr, const char *fmt)
 847 {
 848         int i;
 849
 850         for (i = 0; i < 8; i++) {
 851                 p = pack_hex_byte(p, *addr++);
 852                 p = pack_hex_byte(p, *addr++);
 853                 if (fmt[0] == 'I' && i != 7)
 854                         *p++ = ':';
 855         }
 856         *p = '\0';
 857
 858         return p;
 859 }
 860
 861 static char *ip6_addr_string(char *buf, char *end, const u8 *addr,
 862                              struct printf_spec spec, const char *fmt)
 863 {
 864         char ip6_addr[sizeof("xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255")];
 865
 866         if (fmt[0] == 'I' && fmt[2] == 'c')
 867                 ip6_compressed_string(ip6_addr, addr);
 868         else
 869                 ip6_string(ip6_addr, addr, fmt);
 870
 871         return string(buf, end, ip6_addr, spec);
 872 }
 873
 874 static char *ip4_addr_string(char *buf, char *end, const u8 *addr,
 875                              struct printf_spec spec, const char *fmt)
 876 {
 877         char ip4_addr[sizeof("255.255.255.255")];
 878
 879         ip4_string(ip4_addr, addr, fmt);
 880
 881         return string(buf, end, ip4_addr, spec);
 882 }
 883
 884 static char *uuid_string(char *buf, char *end, const u8 *addr,
 885                          struct printf_spec spec, const char *fmt)
 886 {
 887         char uuid[sizeof("xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx")];
 888         char *p = uuid;
 889         int i;
 890         static const u8 be[16] = {0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15};
 891         static const u8 le[16] = {3,2,1,0,5,4,7,6,8,9,10,11,12,13,14,15};
 892         const u8 *index = be;
 893         bool uc = false;
 894
 895         switch (*(++fmt)) {
 896         case 'L':
 897                 uc = true;              /* fall-through */
 898         case 'l':
 899                 index = le;
 900                 break;
 901         case 'B':
 902                 uc = true;
 903                 break;
 904         }
 905
 906         for (i = 0; i < 16; i++) {
 907                 p = pack_hex_byte(p, addr[index[i]]);
 908                 switch (i) {
 909                 case 3:
 910                 case 5:
 911                 case 7:
 912                 case 9:
 913                         *p++ = '-';
 914                         break;
 915                 }
 916         }
 917
 918         *p = 0;
 919
 920         if (uc) {
 921                 p = uuid;
 922                 do {
 923                         *p = toupper(*p);
 924                 } while (*(++p));
 925         }
 926
 927         return string(buf, end, uuid, spec);
 928 }
 929
 930 /*
 931  * Show a '%p' thing.  A kernel extension is that the '%p' is followed
 932  * by an extra set of alphanumeric characters that are extended format
 933  * specifiers.
 934  *
 935  * Right now we handle:
 936  *
 937  * - 'F' For symbolic function descriptor pointers with offset
 938  * - 'f' For simple symbolic function names without offset
 939  * - 'S' For symbolic direct pointers with offset
 940  * - 's' For symbolic direct pointers without offset
 941  * - 'R' For decoded struct resource, e.g., [mem 0x0-0x1f 64bit pref]
 942  * - 'r' For raw struct resource, e.g., [mem 0x0-0x1f flags 0x201]
 943  * - 'M' For a 6-byte MAC address, it prints the address in the
 944  *       usual colon-separated hex notation
 945  * - 'm' For a 6-byte MAC address, it prints the hex address without colons
 946  * - 'MF' For a 6-byte MAC FDDI address, it prints the address
 947  *       with a dash-separated hex notation
 948  * - 'I' [46] for IPv4/IPv6 addresses printed in the usual way
 949  *       IPv4 uses dot-separated decimal without leading 0's (1.2.3.4)
 950  *       IPv6 uses colon separated network-order 16 bit hex with leading 0's
 951  * - 'i' [46] for 'raw' IPv4/IPv6 addresses
 952  *       IPv6 omits the colons (01020304...0f)
 953  *       IPv4 uses dot-separated decimal with leading 0's (010.123.045.006)
 954  * - '[Ii]4[hnbl]' IPv4 addresses in host, network, big or little endian order
 955  * - 'I6c' for IPv6 addresses printed as specified by
 956  *       http://tools.ietf.org/html/draft-ietf-6man-text-addr-representation-00
 957  * - 'U' For a 16 byte UUID/GUID, it prints the UUID/GUID in the form
 958  *       "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx"
 959  *       Options for %pU are:
 960  *         b big endian lower case hex (default)
 961  *         B big endian UPPER case hex
 962  *         l little endian lower case hex
 963  *         L little endian UPPER case hex
 964  *           big endian output byte order is:
 965  *             [0][1][2][3]-[4][5]-[6][7]-[8][9]-[10][11][12][13][14][15]
 966  *           little endian output byte order is:
 967  *             [3][2][1][0]-[5][4]-[7][6]-[8][9]-[10][11][12][13][14][15]
 968  *
 969  * Note: The difference between 'S' and 'F' is that on ia64 and ppc64
 970  * function pointers are really function descriptors, which contain a
 971  * pointer to the real address.
 972  */
 973 static char *pointer(const char *fmt, char *buf, char *end, void *ptr,
 974                         struct printf_spec spec)
 975 {
 976         if (!ptr)
 977                 return string(buf, end, "(null)", spec);
 978
 979         switch (*fmt) {
 980         case 'F':
 981         case 'f':
 982                 ptr = dereference_function_descriptor(ptr);
 983                 /* Fallthrough */
 984         case 'S':
 985         case 's':
 986                 return symbol_string(buf, end, ptr, spec, *fmt);
 987         case 'R':
 988         case 'r':
 989                 return resource_string(buf, end, ptr, spec, fmt);
 990         case 'M':                       /* Colon separated: 00:01:02:03:04:05 */
 991         case 'm':                       /* Contiguous: 000102030405 */
 992                                         /* [mM]F (FDDI, bit reversed) */
 993                 return mac_address_string(buf, end, ptr, spec, fmt);
 994         case 'I':                       /* Formatted IP supported
 995                                          * 4:   1.2.3.4
 996                                          * 6:   0001:0203:...:0708
 997                                          * 6c:  1::708 or 1::1.2.3.4
 998                                          */
 999         case 'i':                       /* Contiguous:
1000                                          * 4:   001.002.003.004
1001                                          * 6:   000102...0f
1002                                          */
1003                 switch (fmt[1]) {
1004                 case '6':
1005                         return ip6_addr_string(buf, end, ptr, spec, fmt);
1006                 case '4':
1007                         return ip4_addr_string(buf, end, ptr, spec, fmt);
1008                 }
1009                 break;
1010         case 'U':
1011                 return uuid_string(buf, end, ptr, spec, fmt);
1012         }
1013         spec.flags |= SMALL;
1014         if (spec.field_width == -1) {
1015                 spec.field_width = 2*sizeof(void *);
1016                 spec.flags |= ZEROPAD;
1017         }
1018         spec.base = 16;
1019
1020         return number(buf, end, (unsigned long) ptr, spec);
1021 }
1022
1023 /*
1024  * Helper function to decode printf style format.
1025  * Each call decode a token from the format and return the
1026  * number of characters read (or likely the delta where it wants
1027  * to go on the next call).
1028  * The decoded token is returned through the parameters
1029  *
1030  * 'h', 'l', or 'L' for integer fields
1031  * 'z' support added 23/7/1999 S.H.
1032  * 'z' changed to 'Z' --davidm 1/25/99
1033  * 't' added for ptrdiff_t
1034  *
1035  * @fmt: the format string
1036  * @type of the token returned
1037  * @flags: various flags such as +, -, # tokens..
1038  * @field_width: overwritten width
1039  * @base: base of the number (octal, hex, ...)
1040  * @precision: precision of a number
1041  * @qualifier: qualifier of a number (long, size_t, ...)
1042  */
1043 static int format_decode(const char *fmt, struct printf_spec *spec)
1044 {
1045         const char *start = fmt;
1046
1047         /* we finished early by reading the field width */
1048         if (spec->type == FORMAT_TYPE_WIDTH) {
1049                 if (spec->field_width < 0) {
1050                         spec->field_width = -spec->field_width;
1051                         spec->flags |= LEFT;
1052                 }
1053                 spec->type = FORMAT_TYPE_NONE;
1054                 goto precision;
1055         }
1056
1057         /* we finished early by reading the precision */
1058         if (spec->type == FORMAT_TYPE_PRECISION) {
1059                 if (spec->precision < 0)
1060                         spec->precision = 0;
1061
1062                 spec->type = FORMAT_TYPE_NONE;
1063                 goto qualifier;
1064         }
1065
1066         /* By default */
1067         spec->type = FORMAT_TYPE_NONE;
1068
1069         for (; *fmt ; ++fmt) {
1070                 if (*fmt == '%')
1071                         break;
1072         }
1073
1074         /* Return the current non-format string */
1075         if (fmt != start || !*fmt)
1076                 return fmt - start;
1077
1078         /* Process flags */
1079         spec->flags = 0;
1080
1081         while (1) { /* this also skips first '%' */
1082                 bool found = true;
1083
1084                 ++fmt;
1085
1086                 switch (*fmt) {
1087                 case '-': spec->flags |= LEFT;    break;
1088                 case '+': spec->flags |= PLUS;    break;
1089                 case ' ': spec->flags |= SPACE;   break;
1090                 case '#': spec->flags |= SPECIAL; break;
1091                 case '0': spec->flags |= ZEROPAD; break;
1092                 default:  found = false;
1093                 }
1094
1095                 if (!found)
1096                         break;
1097         }
1098
1099         /* get field width */
1100         spec->field_width = -1;
1101
1102         if (isdigit(*fmt))
1103                 spec->field_width = skip_atoi(&fmt);
1104         else if (*fmt == '*') {
1105                 /* it's the next argument */
1106                 spec->type = FORMAT_TYPE_WIDTH;
1107                 return ++fmt - start;
1108         }
1109
1110 precision:
1111         /* get the precision */
1112         spec->precision = -1;
1113         if (*fmt == '.') {
1114                 ++fmt;
1115                 if (isdigit(*fmt)) {
1116                         spec->precision = skip_atoi(&fmt);
1117                         if (spec->precision < 0)
1118                                 spec->precision = 0;
1119                 } else if (*fmt == '*') {
1120                         /* it's the next argument */
1121                         spec->type = FORMAT_TYPE_PRECISION;
1122                         return ++fmt - start;
1123                 }
1124         }
1125
1126 qualifier:
1127         /* get the conversion qualifier */
1128         spec->qualifier = -1;
1129         if (*fmt == 'h' || TOLOWER(*fmt) == 'l' ||
1130             TOLOWER(*fmt) == 'z' || *fmt == 't') {
1131                 spec->qualifier = *fmt++;
1132                 if (unlikely(spec->qualifier == *fmt)) {
1133                         if (spec->qualifier == 'l') {
1134                                 spec->qualifier = 'L';
1135                                 ++fmt;
1136                         } else if (spec->qualifier == 'h') {
1137                                 spec->qualifier = 'H';
1138                                 ++fmt;
1139                         }
1140                 }
1141         }
1142
1143         /* default base */
1144         spec->base = 10;
1145         switch (*fmt) {
1146         case 'c':
1147                 spec->type = FORMAT_TYPE_CHAR;
1148                 return ++fmt - start;
1149
1150         case 's':
1151                 spec->type = FORMAT_TYPE_STR;
1152                 return ++fmt - start;
1153
1154         case 'p':
1155                 spec->type = FORMAT_TYPE_PTR;
1156                 return fmt - start;
1157                 /* skip alnum */
1158
1159         case 'n':
1160                 spec->type = FORMAT_TYPE_NRCHARS;
1161                 return ++fmt - start;
1162
1163         case '%':
1164                 spec->type = FORMAT_TYPE_PERCENT_CHAR;
1165                 return ++fmt - start;
1166
1167         /* integer number formats - set up the flags and "break" */
1168         case 'o':
1169                 spec->base = 8;
1170                 break;
1171
1172         case 'x':
1173                 spec->flags |= SMALL;
1174
1175         case 'X':
1176                 spec->base = 16;
1177                 break;
1178
1179         case 'd':
1180         case 'i':
1181                 spec->flags |= SIGN;
1182         case 'u':
1183                 break;
1184
1185         default:
1186                 spec->type = FORMAT_TYPE_INVALID;
1187                 return fmt - start;
1188         }
1189
1190         if (spec->qualifier == 'L')
1191                 spec->type = FORMAT_TYPE_LONG_LONG;
1192         else if (spec->qualifier == 'l') {
1193                 if (spec->flags & SIGN)
1194                         spec->type = FORMAT_TYPE_LONG;
1195                 else
1196                         spec->type = FORMAT_TYPE_ULONG;
1197         } else if (TOLOWER(spec->qualifier) == 'z') {
1198                 spec->type = FORMAT_TYPE_SIZE_T;
1199         } else if (spec->qualifier == 't') {
1200                 spec->type = FORMAT_TYPE_PTRDIFF;
1201         } else if (spec->qualifier == 'H') {
1202                 if (spec->flags & SIGN)
1203                         spec->type = FORMAT_TYPE_BYTE;
1204                 else
1205                         spec->type = FORMAT_TYPE_UBYTE;
1206         } else if (spec->qualifier == 'h') {
1207                 if (spec->flags & SIGN)
1208                         spec->type = FORMAT_TYPE_SHORT;
1209                 else
1210                         spec->type = FORMAT_TYPE_USHORT;
1211         } else {
1212                 if (spec->flags & SIGN)
1213                         spec->type = FORMAT_TYPE_INT;
1214                 else
1215                         spec->type = FORMAT_TYPE_UINT;
1216         }
1217
1218         return ++fmt - start;
1219 }
1220
1221 /**
1222  * vsnprintf - Format a string and place it in a buffer
1223  * @buf: The buffer to place the result into
1224  * @size: The size of the buffer, including the trailing null space
1225  * @fmt: The format string to use
1226  * @args: Arguments for the format string
1227  *
1228  * This function follows C99 vsnprintf, but has some extensions:
1229  * %pS output the name of a text symbol with offset
1230  * %ps output the name of a text symbol without offset
1231  * %pF output the name of a function pointer with its offset
1232  * %pf output the name of a function pointer without its offset
1233  * %pR output the address range in a struct resource with decoded flags
1234  * %pr output the address range in a struct resource with raw flags
1235  * %pM output a 6-byte MAC address with colons
1236  * %pm output a 6-byte MAC address without colons
1237  * %pI4 print an IPv4 address without leading zeros
1238  * %pi4 print an IPv4 address with leading zeros
1239  * %pI6 print an IPv6 address with colons
1240  * %pi6 print an IPv6 address without colons
1241  * %pI6c print an IPv6 address as specified by
1242  *   http://tools.ietf.org/html/draft-ietf-6man-text-addr-representation-00
1243  * %pU[bBlL] print a UUID/GUID in big or little endian using lower or upper
1244  *   case.
1245  * %n is ignored
1246  *
1247  * The return value is the number of characters which would
1248  * be generated for the given input, excluding the trailing
1249  * '\0', as per ISO C99. If you want to have the exact
1250  * number of characters written into @buf as return value
1251  * (not including the trailing '\0'), use vscnprintf(). If the
1252  * return is greater than or equal to @size, the resulting
1253  * string is truncated.
1254  *
1255  * Call this function if you are already dealing with a va_list.
1256  * You probably want snprintf() instead.
1257  */
1258 int vsnprintf(char *buf, size_t size, const char *fmt, va_list args)
1259 {
1260         unsigned long long num;
1261         char *str, *end;
1262         struct printf_spec spec = {0};
1263
1264         /* Reject out-of-range values early.  Large positive sizes are
1265            used for unknown buffer sizes. */
1266         if (WARN_ON_ONCE((int) size < 0))
1267                 return 0;
1268
1269         str = buf;
1270         end = buf + size;
1271
1272         /* Make sure end is always >= buf */
1273         if (end < buf) {
1274                 end = ((void *)-1);
1275                 size = end - buf;
1276         }
1277
1278         while (*fmt) {
1279                 const char *old_fmt = fmt;
1280                 int read = format_decode(fmt, &spec);
1281
1282                 fmt += read;
1283
1284                 switch (spec.type) {
1285                 case FORMAT_TYPE_NONE: {
1286                         int copy = read;
1287                         if (str < end) {
1288                                 if (copy > end - str)
1289                                         copy = end - str;
1290                                 memcpy(str, old_fmt, copy);
1291                         }
1292                         str += read;
1293                         break;
1294                 }
1295
1296                 case FORMAT_TYPE_WIDTH:
1297                         spec.field_width = va_arg(args, int);
1298                         break;
1299
1300                 case FORMAT_TYPE_PRECISION:
1301                         spec.precision = va_arg(args, int);
1302                         break;
1303
1304                 case FORMAT_TYPE_CHAR: {
1305                         char c;
1306
1307                         if (!(spec.flags & LEFT)) {
1308                                 while (--spec.field_width > 0) {
1309                                         if (str < end)
1310                                                 *str = ' ';
1311                                         ++str;
1312
1313                                 }
1314                         }
1315                         c = (unsigned char) va_arg(args, int);
1316                         if (str < end)
1317                                 *str = c;
1318                         ++str;
1319                         while (--spec.field_width > 0) {
1320                                 if (str < end)
1321                                         *str = ' ';
1322                                 ++str;
1323                         }
1324                         break;
1325                 }
1326
1327                 case FORMAT_TYPE_STR:
1328                         str = string(str, end, va_arg(args, char *), spec);
1329                         break;
1330
1331                 case FORMAT_TYPE_PTR:
1332                         str = pointer(fmt+1, str, end, va_arg(args, void *),
1333                                       spec);
1334                         while (isalnum(*fmt))
1335                                 fmt++;
1336                         break;
1337
1338                 case FORMAT_TYPE_PERCENT_CHAR:
1339                         if (str < end)
1340                                 *str = '%';
1341                         ++str;
1342                         break;
1343
1344                 case FORMAT_TYPE_INVALID:
1345                         if (str < end)
1346                                 *str = '%';
1347                         ++str;
1348                         break;
1349
1350                 case FORMAT_TYPE_NRCHARS: {
1351                         u8 qualifier = spec.qualifier;
1352
1353                         if (qualifier == 'l') {
1354                                 long *ip = va_arg(args, long *);
1355                                 *ip = (str - buf);
1356                         } else if (TOLOWER(qualifier) == 'z') {
1357                                 size_t *ip = va_arg(args, size_t *);
1358                                 *ip = (str - buf);
1359                         } else {
1360                                 int *ip = va_arg(args, int *);
1361                                 *ip = (str - buf);
1362                         }
1363                         break;
1364                 }
1365
1366                 default:
1367                         switch (spec.type) {
1368                         case FORMAT_TYPE_LONG_LONG:
1369                                 num = va_arg(args, long long);
1370                                 break;
1371                         case FORMAT_TYPE_ULONG:
1372                                 num = va_arg(args, unsigned long);
1373                                 break;
1374                         case FORMAT_TYPE_LONG:
1375                                 num = va_arg(args, long);
1376                                 break;
1377                         case FORMAT_TYPE_SIZE_T:
1378                                 num = va_arg(args, size_t);
1379                                 break;
1380                         case FORMAT_TYPE_PTRDIFF:
1381                                 num = va_arg(args, ptrdiff_t);
1382                                 break;
1383                         case FORMAT_TYPE_UBYTE:
1384                                 num = (unsigned char) va_arg(args, int);
1385                                 break;
1386                         case FORMAT_TYPE_BYTE:
1387                                 num = (signed char) va_arg(args, int);
1388                                 break;
1389                         case FORMAT_TYPE_USHORT:
1390                                 num = (unsigned short) va_arg(args, int);
1391                                 break;
1392                         case FORMAT_TYPE_SHORT:
1393                                 num = (short) va_arg(args, int);
1394                                 break;
1395                         case FORMAT_TYPE_INT:
1396                                 num = (int) va_arg(args, int);
1397                                 break;
1398                         default:
1399                                 num = va_arg(args, unsigned int);
1400                         }
1401
1402                         str = number(str, end, num, spec);
1403                 }
1404         }
1405
1406         if (size > 0) {
1407                 if (str < end)
1408                         *str = '\0';
1409                 else
1410                         end[-1] = '\0';
1411         }
1412
1413         /* the trailing null byte doesn't count towards the total */
1414         return str-buf;
1415
1416 }
1417 EXPORT_SYMBOL(vsnprintf);
1418
1419 /**
1420  * vscnprintf - Format a string and place it in a buffer
1421  * @buf: The buffer to place the result into
1422  * @size: The size of the buffer, including the trailing null space
1423  * @fmt: The format string to use
1424  * @args: Arguments for the format string
1425  *
1426  * The return value is the number of characters which have been written into
1427  * the @buf not including the trailing '\0'. If @size is <= 0 the function
1428  * returns 0.
1429  *
1430  * Call this function if you are already dealing with a va_list.
1431  * You probably want scnprintf() instead.
1432  *
1433  * See the vsnprintf() documentation for format string extensions over C99.
1434  */
1435 int vscnprintf(char *buf, size_t size, const char *fmt, va_list args)
1436 {
1437         int i;
1438
1439         i = vsnprintf(buf, size, fmt, args);
1440
1441         return (i >= size) ? (size - 1) : i;
1442 }
1443 EXPORT_SYMBOL(vscnprintf);
1444
1445 /**
1446  * snprintf - Format a string and place it in a buffer
1447  * @buf: The buffer to place the result into
1448  * @size: The size of the buffer, including the trailing null space
1449  * @fmt: The format string to use
1450  * @...: Arguments for the format string
1451  *
1452  * The return value is the number of characters which would be
1453  * generated for the given input, excluding the trailing null,
1454  * as per ISO C99.  If the return is greater than or equal to
1455  * @size, the resulting string is truncated.
1456  *
1457  * See the vsnprintf() documentation for format string extensions over C99.
1458  */
1459 int snprintf(char *buf, size_t size, const char *fmt, ...)
1460 {
1461         va_list args;
1462         int i;
1463
1464         va_start(args, fmt);
1465         i = vsnprintf(buf, size, fmt, args);
1466         va_end(args);
1467
1468         return i;
1469 }
1470 EXPORT_SYMBOL(snprintf);
1471
1472 /**
1473  * scnprintf - Format a string and place it in a buffer
1474  * @buf: The buffer to place the result into
1475  * @size: The size of the buffer, including the trailing null space
1476  * @fmt: The format string to use
1477  * @...: Arguments for the format string
1478  *
1479  * The return value is the number of characters written into @buf not including
1480  * the trailing '\0'. If @size is <= 0 the function returns 0.
1481  */
1482
1483 int scnprintf(char *buf, size_t size, const char *fmt, ...)
1484 {
1485         va_list args;
1486         int i;
1487
1488         va_start(args, fmt);
1489         i = vsnprintf(buf, size, fmt, args);
1490         va_end(args);
1491
1492         return (i >= size) ? (size - 1) : i;
1493 }
1494 EXPORT_SYMBOL(scnprintf);
1495
1496 /**
1497  * vsprintf - Format a string and place it in a buffer
1498  * @buf: The buffer to place the result into
1499  * @fmt: The format string to use
1500  * @args: Arguments for the format string
1501  *
1502  * The function returns the number of characters written
1503  * into @buf. Use vsnprintf() or vscnprintf() in order to avoid
1504  * buffer overflows.
1505  *
1506  * Call this function if you are already dealing with a va_list.
1507  * You probably want sprintf() instead.
1508  *
1509  * See the vsnprintf() documentation for format string extensions over C99.
1510  */
1511 int vsprintf(char *buf, const char *fmt, va_list args)
1512 {
1513         return vsnprintf(buf, INT_MAX, fmt, args);
1514 }
1515 EXPORT_SYMBOL(vsprintf);
1516
1517 /**
1518  * sprintf - Format a string and place it in a buffer
1519  * @buf: The buffer to place the result into
1520  * @fmt: The format string to use
1521  * @...: Arguments for the format string
1522  *
1523  * The function returns the number of characters written
1524  * into @buf. Use snprintf() or scnprintf() in order to avoid
1525  * buffer overflows.
1526  *
1527  * See the vsnprintf() documentation for format string extensions over C99.
1528  */
1529 int sprintf(char *buf, const char *fmt, ...)
1530 {
1531         va_list args;
1532         int i;
1533
1534         va_start(args, fmt);
1535         i = vsnprintf(buf, INT_MAX, fmt, args);
1536         va_end(args);
1537
1538         return i;
1539 }
1540 EXPORT_SYMBOL(sprintf);
1541
1542 #ifdef CONFIG_BINARY_PRINTF
1543 /*
1544  * bprintf service:
1545  * vbin_printf() - VA arguments to binary data
1546  * bstr_printf() - Binary data to text string
1547  */
1548
1549 /**
1550  * vbin_printf - Parse a format string and place args' binary value in a buffer
1551  * @bin_buf: The buffer to place args' binary value
1552  * @size: The size of the buffer(by words(32bits), not characters)
1553  * @fmt: The format string to use
1554  * @args: Arguments for the format string
1555  *
1556  * The format follows C99 vsnprintf, except %n is ignored, and its argument
1557  * is skiped.
1558  *
1559  * The return value is the number of words(32bits) which would be generated for
1560  * the given input.
1561  *
1562  * NOTE:
1563  * If the return value is greater than @size, the resulting bin_buf is NOT
1564  * valid for bstr_printf().
1565  */
1566 int vbin_printf(u32 *bin_buf, size_t size, const char *fmt, va_list args)
1567 {
1568         struct printf_spec spec = {0};
1569         char *str, *end;
1570
1571         str = (char *)bin_buf;
1572         end = (char *)(bin_buf + size);
1573
1574 #define save_arg(type)                                                  \
1575 do {                                                                    \
1576         if (sizeof(type) == 8) {                                        \
1577                 unsigned long long value;                               \
1578                 str = PTR_ALIGN(str, sizeof(u32));                      \
1579                 value = va_arg(args, unsigned long long);               \
1580                 if (str + sizeof(type) <= end) {                        \
1581                         *(u32 *)str = *(u32 *)&value;                   \
1582                         *(u32 *)(str + 4) = *((u32 *)&value + 1);       \
1583                 }                                                       \
1584         } else {                                                        \
1585                 unsigned long value;                                    \
1586                 str = PTR_ALIGN(str, sizeof(type));                     \
1587                 value = va_arg(args, int);                              \
1588                 if (str + sizeof(type) <= end)                          \
1589                         *(typeof(type) *)str = (type)value;             \
1590         }                                                               \
1591         str += sizeof(type);                                            \
1592 } while (0)
1593
1594         while (*fmt) {
1595                 int read = format_decode(fmt, &spec);
1596
1597                 fmt += read;
1598
1599                 switch (spec.type) {
1600                 case FORMAT_TYPE_NONE:
1601                 case FORMAT_TYPE_INVALID:
1602                 case FORMAT_TYPE_PERCENT_CHAR:
1603                         break;
1604
1605                 case FORMAT_TYPE_WIDTH:
1606                 case FORMAT_TYPE_PRECISION:
1607                         save_arg(int);
1608                         break;
1609
1610                 case FORMAT_TYPE_CHAR:
1611                         save_arg(char);
1612                         break;
1613
1614                 case FORMAT_TYPE_STR: {
1615                         const char *save_str = va_arg(args, char *);
1616                         size_t len;
1617
1618                         if ((unsigned long)save_str > (unsigned long)-PAGE_SIZE
1619                                         || (unsigned long)save_str < PAGE_SIZE)
1620                                 save_str = "(null)";
1621                         len = strlen(save_str) + 1;
1622                         if (str + len < end)
1623                                 memcpy(str, save_str, len);
1624                         str += len;
1625                         break;
1626                 }
1627
1628                 case FORMAT_TYPE_PTR:
1629                         save_arg(void *);
1630                         /* skip all alphanumeric pointer suffixes */
1631                         while (isalnum(*fmt))
1632                                 fmt++;
1633                         break;
1634
1635                 case FORMAT_TYPE_NRCHARS: {
1636                         /* skip %n 's argument */
1637                         u8 qualifier = spec.qualifier;
1638                         void *skip_arg;
1639                         if (qualifier == 'l')
1640                                 skip_arg = va_arg(args, long *);
1641                         else if (TOLOWER(qualifier) == 'z')
1642                                 skip_arg = va_arg(args, size_t *);
1643                         else
1644                                 skip_arg = va_arg(args, int *);
1645                         break;
1646                 }
1647
1648                 default:
1649                         switch (spec.type) {
1650
1651                         case FORMAT_TYPE_LONG_LONG:
1652                                 save_arg(long long);
1653                                 break;
1654                         case FORMAT_TYPE_ULONG:
1655                         case FORMAT_TYPE_LONG:
1656                                 save_arg(unsigned long);
1657                                 break;
1658                         case FORMAT_TYPE_SIZE_T:
1659                                 save_arg(size_t);
1660                                 break;
1661                         case FORMAT_TYPE_PTRDIFF:
1662                                 save_arg(ptrdiff_t);
1663                                 break;
1664                         case FORMAT_TYPE_UBYTE:
1665                         case FORMAT_TYPE_BYTE:
1666                                 save_arg(char);
1667                                 break;
1668                         case FORMAT_TYPE_USHORT:
1669                         case FORMAT_TYPE_SHORT:
1670                                 save_arg(short);
1671                                 break;
1672                         default:
1673                                 save_arg(int);
1674                         }
1675                 }
1676         }
1677
1678         return (u32 *)(PTR_ALIGN(str, sizeof(u32))) - bin_buf;
1679 #undef save_arg
1680 }
1681 EXPORT_SYMBOL_GPL(vbin_printf);
1682
1683 /**
1684  * bstr_printf - Format a string from binary arguments and place it in a buffer
1685  * @buf: The buffer to place the result into
1686  * @size: The size of the buffer, including the trailing null space
1687  * @fmt: The format string to use
1688  * @bin_buf: Binary arguments for the format string
1689  *
1690  * This function like C99 vsnprintf, but the difference is that vsnprintf gets
1691  * arguments from stack, and bstr_printf gets arguments from @bin_buf which is
1692  * a binary buffer that generated by vbin_printf.
1693  *
1694  * The format follows C99 vsnprintf, but has some extensions:
1695  *  see vsnprintf comment for details.
1696  *
1697  * The return value is the number of characters which would
1698  * be generated for the given input, excluding the trailing
1699  * '\0', as per ISO C99. If you want to have the exact
1700  * number of characters written into @buf as return value
1701  * (not including the trailing '\0'), use vscnprintf(). If the
1702  * return is greater than or equal to @size, the resulting
1703  * string is truncated.
1704  */
1705 int bstr_printf(char *buf, size_t size, const char *fmt, const u32 *bin_buf)
1706 {
1707         struct printf_spec spec = {0};
1708         char *str, *end;
1709         const char *args = (const char *)bin_buf;
1710
1711         if (WARN_ON_ONCE((int) size < 0))
1712                 return 0;
1713
1714         str = buf;
1715         end = buf + size;
1716
1717 #define get_arg(type)                                                   \
1718 ({                                                                      \
1719         typeof(type) value;                                             \
1720         if (sizeof(type) == 8) {                                        \
1721                 args = PTR_ALIGN(args, sizeof(u32));                    \
1722                 *(u32 *)&value = *(u32 *)args;                          \
1723                 *((u32 *)&value + 1) = *(u32 *)(args + 4);              \
1724         } else {                                                        \
1725                 args = PTR_ALIGN(args, sizeof(type));                   \
1726                 value = *(typeof(type) *)args;                          \
1727         }                                                               \
1728         args += sizeof(type);                                           \
1729         value;                                                          \
1730 })
1731
1732         /* Make sure end is always >= buf */
1733         if (end < buf) {
1734                 end = ((void *)-1);
1735                 size = end - buf;
1736         }
1737
1738         while (*fmt) {
1739                 const char *old_fmt = fmt;
1740                 int read = format_decode(fmt, &spec);
1741
1742                 fmt += read;
1743
1744                 switch (spec.type) {
1745                 case FORMAT_TYPE_NONE: {
1746                         int copy = read;
1747                         if (str < end) {
1748                                 if (copy > end - str)
1749                                         copy = end - str;
1750                                 memcpy(str, old_fmt, copy);
1751                         }
1752                         str += read;
1753                         break;
1754                 }
1755
1756                 case FORMAT_TYPE_WIDTH:
1757                         spec.field_width = get_arg(int);
1758                         break;
1759
1760                 case FORMAT_TYPE_PRECISION:
1761                         spec.precision = get_arg(int);
1762                         break;
1763
1764                 case FORMAT_TYPE_CHAR: {
1765                         char c;
1766
1767                         if (!(spec.flags & LEFT)) {
1768                                 while (--spec.field_width > 0) {
1769                                         if (str < end)
1770                                                 *str = ' ';
1771                                         ++str;
1772                                 }
1773                         }
1774                         c = (unsigned char) get_arg(char);
1775                         if (str < end)
1776                                 *str = c;
1777                         ++str;
1778                         while (--spec.field_width > 0) {
1779                                 if (str < end)
1780                                         *str = ' ';
1781                                 ++str;
1782                         }
1783                         break;
1784                 }
1785
1786                 case FORMAT_TYPE_STR: {
1787                         const char *str_arg = args;
1788                         args += strlen(str_arg) + 1;
1789                         str = string(str, end, (char *)str_arg, spec);
1790                         break;
1791                 }
1792
1793                 case FORMAT_TYPE_PTR:
1794                         str = pointer(fmt+1, str, end, get_arg(void *), spec);
1795                         while (isalnum(*fmt))
1796                                 fmt++;
1797                         break;
1798
1799                 case FORMAT_TYPE_PERCENT_CHAR:
1800                 case FORMAT_TYPE_INVALID:
1801                         if (str < end)
1802                                 *str = '%';
1803                         ++str;
1804                         break;
1805
1806                 case FORMAT_TYPE_NRCHARS:
1807                         /* skip */
1808                         break;
1809
1810                 default: {
1811                         unsigned long long num;
1812
1813                         switch (spec.type) {
1814
1815                         case FORMAT_TYPE_LONG_LONG:
1816                                 num = get_arg(long long);
1817                                 break;
1818                         case FORMAT_TYPE_ULONG:
1819                         case FORMAT_TYPE_LONG:
1820                                 num = get_arg(unsigned long);
1821                                 break;
1822                         case FORMAT_TYPE_SIZE_T:
1823                                 num = get_arg(size_t);
1824                                 break;
1825                         case FORMAT_TYPE_PTRDIFF:
1826                                 num = get_arg(ptrdiff_t);
1827                                 break;
1828                         case FORMAT_TYPE_UBYTE:
1829                                 num = get_arg(unsigned char);
1830                                 break;
1831                         case FORMAT_TYPE_BYTE:
1832                                 num = get_arg(signed char);
1833                                 break;
1834                         case FORMAT_TYPE_USHORT:
1835                                 num = get_arg(unsigned short);
1836                                 break;
1837                         case FORMAT_TYPE_SHORT:
1838                                 num = get_arg(short);
1839                                 break;
1840                         case FORMAT_TYPE_UINT:
1841                                 num = get_arg(unsigned int);
1842                                 break;
1843                         default:
1844                                 num = get_arg(int);
1845                         }
1846
1847                         str = number(str, end, num, spec);
1848                 } /* default: */
1849                 } /* switch(spec.type) */
1850         } /* while(*fmt) */
1851
1852         if (size > 0) {
1853                 if (str < end)
1854                         *str = '\0';
1855                 else
1856                         end[-1] = '\0';
1857         }
1858
1859 #undef get_arg
1860
1861         /* the trailing null byte doesn't count towards the total */
1862         return str - buf;
1863 }
1864 EXPORT_SYMBOL_GPL(bstr_printf);
1865
1866 /**
1867  * bprintf - Parse a format string and place args' binary value in a buffer
1868  * @bin_buf: The buffer to place args' binary value
1869  * @size: The size of the buffer(by words(32bits), not characters)
1870  * @fmt: The format string to use
1871  * @...: Arguments for the format string
1872  *
1873  * The function returns the number of words(u32) written
1874  * into @bin_buf.
1875  */
1876 int bprintf(u32 *bin_buf, size_t size, const char *fmt, ...)
1877 {
1878         va_list args;
1879         int ret;
1880
1881         va_start(args, fmt);
1882         ret = vbin_printf(bin_buf, size, fmt, args);
1883         va_end(args);
1884
1885         return ret;
1886 }
1887 EXPORT_SYMBOL_GPL(bprintf);
1888
1889 #endif /* CONFIG_BINARY_PRINTF */
1890
1891 /**
1892  * vsscanf - Unformat a buffer into a list of arguments
1893  * @buf:        input buffer
1894  * @fmt:        format of buffer
1895  * @args:       arguments
1896  */
1897 int vsscanf(const char *buf, const char *fmt, va_list args)
1898 {
1899         const char *str = buf;
1900         char *next;
1901         char digit;
1902         int num = 0;
1903         u8 qualifier;
1904         u8 base;
1905         s16 field_width;
1906         bool is_sign;
1907
1908         while (*fmt && *str) {
1909                 /* skip any white space in format */
1910                 /* white space in format matchs any amount of
1911                  * white space, including none, in the input.
1912                  */
1913                 if (isspace(*fmt)) {
1914                         fmt = skip_spaces(++fmt);
1915                         str = skip_spaces(str);
1916                 }
1917
1918                 /* anything that is not a conversion must match exactly */
1919                 if (*fmt != '%' && *fmt) {
1920                         if (*fmt++ != *str++)
1921                                 break;
1922                         continue;
1923                 }
1924
1925                 if (!*fmt)
1926                         break;
1927                 ++fmt;
1928
1929                 /* skip this conversion.
1930                  * advance both strings to next white space
1931                  */
1932                 if (*fmt == '*') {
1933                         while (!isspace(*fmt) && *fmt != '%' && *fmt)
1934                                 fmt++;
1935                         while (!isspace(*str) && *str)
1936                                 str++;
1937                         continue;
1938                 }
1939
1940                 /* get field width */
1941                 field_width = -1;
1942                 if (isdigit(*fmt))
1943                         field_width = skip_atoi(&fmt);
1944
1945                 /* get conversion qualifier */
1946                 qualifier = -1;
1947                 if (*fmt == 'h' || TOLOWER(*fmt) == 'l' ||
1948                     TOLOWER(*fmt) == 'z') {
1949                         qualifier = *fmt++;
1950                         if (unlikely(qualifier == *fmt)) {
1951                                 if (qualifier == 'h') {
1952                                         qualifier = 'H';
1953                                         fmt++;
1954                                 } else if (qualifier == 'l') {
1955                                         qualifier = 'L';
1956                                         fmt++;
1957                                 }
1958                         }
1959                 }
1960
1961                 if (!*fmt || !*str)
1962                         break;
1963
1964                 base = 10;
1965                 is_sign = 0;
1966
1967                 switch (*fmt++) {
1968                 case 'c':
1969                 {
1970                         char *s = (char *)va_arg(args, char*);
1971                         if (field_width == -1)
1972                                 field_width = 1;
1973                         do {
1974                                 *s++ = *str++;
1975                         } while (--field_width > 0 && *str);
1976                         num++;
1977                 }
1978                 continue;
1979                 case 's':
1980                 {
1981                         char *s = (char *)va_arg(args, char *);
1982                         if (field_width == -1)
1983                                 field_width = SHORT_MAX;
1984                         /* first, skip leading white space in buffer */
1985                         str = skip_spaces(str);
1986
1987                         /* now copy until next white space */
1988                         while (*str && !isspace(*str) && field_width--)
1989                                 *s++ = *str++;
1990                         *s = '\0';
1991                         num++;
1992                 }
1993                 continue;
1994                 case 'n':
1995                         /* return number of characters read so far */
1996                 {
1997                         int *i = (int *)va_arg(args, int*);
1998                         *i = str - buf;
1999                 }
2000                 continue;
2001                 case 'o':
2002                         base = 8;
2003                         break;
2004                 case 'x':
2005                 case 'X':
2006                         base = 16;
2007                         break;
2008                 case 'i':
2009                         base = 0;
2010                 case 'd':
2011                         is_sign = 1;
2012                 case 'u':
2013                         break;
2014                 case '%':
2015                         /* looking for '%' in str */
2016                         if (*str++ != '%')
2017                                 return num;
2018                         continue;
2019                 default:
2020                         /* invalid format; stop here */
2021                         return num;
2022                 }
2023
2024                 /* have some sort of integer conversion.
2025                  * first, skip white space in buffer.
2026                  */
2027                 str = skip_spaces(str);
2028
2029                 digit = *str;
2030                 if (is_sign && digit == '-')
2031                         digit = *(str + 1);
2032
2033                 if (!digit
2034                     || (base == 16 && !isxdigit(digit))
2035                     || (base == 10 && !isdigit(digit))
2036                     || (base == 8 && (!isdigit(digit) || digit > '7'))
2037                     || (base == 0 && !isdigit(digit)))
2038                         break;
2039
2040                 switch (qualifier) {
2041                 case 'H':       /* that's 'hh' in format */
2042                         if (is_sign) {
2043                                 signed char *s = (signed char *)va_arg(args, signed char *);
2044                                 *s = (signed char)simple_strtol(str, &next, base);
2045                         } else {
2046                                 unsigned char *s = (unsigned char *)va_arg(args, unsigned char *);
2047                                 *s = (unsigned char)simple_strtoul(str, &next, base);
2048                         }
2049                         break;
2050                 case 'h':
2051                         if (is_sign) {
2052                                 short *s = (short *)va_arg(args, short *);
2053                                 *s = (short)simple_strtol(str, &next, base);
2054                         } else {
2055                                 unsigned short *s = (unsigned short *)va_arg(args, unsigned short *);
2056                                 *s = (unsigned short)simple_strtoul(str, &next, base);
2057                         }
2058                         break;
2059                 case 'l':
2060                         if (is_sign) {
2061                                 long *l = (long *)va_arg(args, long *);
2062                                 *l = simple_strtol(str, &next, base);
2063                         } else {
2064                                 unsigned long *l = (unsigned long *)va_arg(args, unsigned long *);
2065                                 *l = simple_strtoul(str, &next, base);
2066                         }
2067                         break;
2068                 case 'L':
2069                         if (is_sign) {
2070                                 long long *l = (long long *)va_arg(args, long long *);
2071                                 *l = simple_strtoll(str, &next, base);
2072                         } else {
2073                                 unsigned long long *l = (unsigned long long *)va_arg(args, unsigned long long *);
2074                                 *l = simple_strtoull(str, &next, base);
2075                         }
2076                         break;
2077                 case 'Z':
2078                 case 'z':
2079                 {
2080                         size_t *s = (size_t *)va_arg(args, size_t *);
2081                         *s = (size_t)simple_strtoul(str, &next, base);
2082                 }
2083                 break;
2084                 default:
2085                         if (is_sign) {
2086                                 int *i = (int *)va_arg(args, int *);
2087                                 *i = (int)simple_strtol(str, &next, base);
2088                         } else {
2089                                 unsigned int *i = (unsigned int *)va_arg(args, unsigned int*);
2090                                 *i = (unsigned int)simple_strtoul(str, &next, base);
2091                         }
2092                         break;
2093                 }
2094                 num++;
2095
2096                 if (!next)
2097                         break;
2098                 str = next;
2099         }
2100
2101         /*
2102          * Now we've come all the way through so either the input string or the
2103          * format ended. In the former case, there can be a %n at the current
2104          * position in the format that needs to be filled.
2105          */
2106         if (*fmt == '%' && *(fmt + 1) == 'n') {
2107                 int *p = (int *)va_arg(args, int *);
2108                 *p = str - buf;
2109         }
2110
2111         return num;
2112 }
2113 EXPORT_SYMBOL(vsscanf);
2114
2115 /**
2116  * sscanf - Unformat a buffer into a list of arguments
2117  * @buf:        input buffer
2118  * @fmt:        formatting of buffer
2119  * @...:        resulting arguments
2120  */
2121 int sscanf(const char *buf, const char *fmt, ...)
2122 {
2123         va_list args;
2124         int i;
2125
2126         va_start(args, fmt);
2127         i = vsscanf(buf, fmt, args);
2128         va_end(args);
2129
2130         return i;
2131 }
2132 EXPORT_SYMBOL(sscanf);