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
  28 #include <asm/page.h>           /* for PAGE_SIZE */
  29 #include <asm/div64.h>
  30
  31 /* Works only for digits and letters, but small and fast */
  32 #define TOLOWER(x) ((x) | 0x20)
  33
  34 /**
  35  * simple_strtoul - convert a string to an unsigned long
  36  * @cp: The start of the string
  37  * @endp: A pointer to the end of the parsed string will be placed here
  38  * @base: The number base to use
  39  */
  40 unsigned long simple_strtoul(const char *cp,char **endp,unsigned int base)
  41 {
  42         unsigned long result = 0,value;
  43
  44         if (!base) {
  45                 base = 10;
  46                 if (*cp == '0') {
  47                         base = 8;
  48                         cp++;
  49                         if ((TOLOWER(*cp) == 'x') && isxdigit(cp[1])) {
  50                                 cp++;
  51                                 base = 16;
  52                         }
  53                 }
  54         } else if (base == 16) {
  55                 if (cp[0] == '0' && TOLOWER(cp[1]) == 'x')
  56                         cp += 2;
  57         }
  58         while (isxdigit(*cp) &&
  59                (value = isdigit(*cp) ? *cp-'0' : TOLOWER(*cp)-'a'+10) < base) {
  60                 result = result*base + value;
  61                 cp++;
  62         }
  63         if (endp)
  64                 *endp = (char *)cp;
  65         return result;
  66 }
  67
  68 EXPORT_SYMBOL(simple_strtoul);
  69
  70 /**
  71  * simple_strtol - convert a string to a signed long
  72  * @cp: The start of the string
  73  * @endp: A pointer to the end of the parsed string will be placed here
  74  * @base: The number base to use
  75  */
  76 long simple_strtol(const char *cp,char **endp,unsigned int base)
  77 {
  78         if(*cp=='-')
  79                 return -simple_strtoul(cp+1,endp,base);
  80         return simple_strtoul(cp,endp,base);
  81 }
  82
  83 EXPORT_SYMBOL(simple_strtol);
  84
  85 /**
  86  * simple_strtoull - convert a string to an unsigned long long
  87  * @cp: The start of the string
  88  * @endp: A pointer to the end of the parsed string will be placed here
  89  * @base: The number base to use
  90  */
  91 unsigned long long simple_strtoull(const char *cp,char **endp,unsigned int base)
  92 {
  93         unsigned long long result = 0,value;
  94
  95         if (!base) {
  96                 base = 10;
  97                 if (*cp == '0') {
  98                         base = 8;
  99                         cp++;
 100                         if ((TOLOWER(*cp) == 'x') && isxdigit(cp[1])) {
 101                                 cp++;
 102                                 base = 16;
 103                         }
 104                 }
 105         } else if (base == 16) {
 106                 if (cp[0] == '0' && TOLOWER(cp[1]) == 'x')
 107                         cp += 2;
 108         }
 109         while (isxdigit(*cp)
 110          && (value = isdigit(*cp) ? *cp-'0' : TOLOWER(*cp)-'a'+10) < base) {
 111                 result = result*base + value;
 112                 cp++;
 113         }
 114         if (endp)
 115                 *endp = (char *)cp;
 116         return result;
 117 }
 118
 119 EXPORT_SYMBOL(simple_strtoull);
 120
 121 /**
 122  * simple_strtoll - convert a string to a signed long long
 123  * @cp: The start of the string
 124  * @endp: A pointer to the end of the parsed string will be placed here
 125  * @base: The number base to use
 126  */
 127 long long simple_strtoll(const char *cp,char **endp,unsigned int base)
 128 {
 129         if(*cp=='-')
 130                 return -simple_strtoull(cp+1,endp,base);
 131         return simple_strtoull(cp,endp,base);
 132 }
 133
 134
 135 /**
 136  * strict_strtoul - convert a string to an unsigned long strictly
 137  * @cp: The string to be converted
 138  * @base: The number base to use
 139  * @res: The converted result value
 140  *
 141  * strict_strtoul converts a string to an unsigned long only if the
 142  * string is really an unsigned long string, any string containing
 143  * any invalid char at the tail will be rejected and -EINVAL is returned,
 144  * only a newline char at the tail is acceptible because people generally
 145  * change a module parameter in the following way:
 146  *
 147  *      echo 1024 > /sys/module/e1000/parameters/copybreak
 148  *
 149  * echo will append a newline to the tail.
 150  *
 151  * It returns 0 if conversion is successful and *res is set to the converted
 152  * value, otherwise it returns -EINVAL and *res is set to 0.
 153  *
 154  * simple_strtoul just ignores the successive invalid characters and
 155  * return the converted value of prefix part of the string.
 156  */
 157 int strict_strtoul(const char *cp, unsigned int base, unsigned long *res);
 158
 159 /**
 160  * strict_strtol - convert a string to a long strictly
 161  * @cp: The string to be converted
 162  * @base: The number base to use
 163  * @res: The converted result value
 164  *
 165  * strict_strtol is similiar to strict_strtoul, but it allows the first
 166  * character of a string is '-'.
 167  *
 168  * It returns 0 if conversion is successful and *res is set to the converted
 169  * value, otherwise it returns -EINVAL and *res is set to 0.
 170  */
 171 int strict_strtol(const char *cp, unsigned int base, long *res);
 172
 173 /**
 174  * strict_strtoull - convert a string to an unsigned long long strictly
 175  * @cp: The string to be converted
 176  * @base: The number base to use
 177  * @res: The converted result value
 178  *
 179  * strict_strtoull converts a string to an unsigned long long only if the
 180  * string is really an unsigned long long string, any string containing
 181  * any invalid char at the tail will be rejected and -EINVAL is returned,
 182  * only a newline char at the tail is acceptible because people generally
 183  * change a module parameter in the following way:
 184  *
 185  *      echo 1024 > /sys/module/e1000/parameters/copybreak
 186  *
 187  * echo will append a newline to the tail of the string.
 188  *
 189  * It returns 0 if conversion is successful and *res is set to the converted
 190  * value, otherwise it returns -EINVAL and *res is set to 0.
 191  *
 192  * simple_strtoull just ignores the successive invalid characters and
 193  * return the converted value of prefix part of the string.
 194  */
 195 int strict_strtoull(const char *cp, unsigned int base, unsigned long long *res);
 196
 197 /**
 198  * strict_strtoll - convert a string to a 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_strtoll is similiar to strict_strtoull, but it allows the first
 204  * character of a string is '-'.
 205  *
 206  * It returns 0 if conversion is successful and *res is set to the converted
 207  * value, otherwise it returns -EINVAL and *res is set to 0.
 208  */
 209 int strict_strtoll(const char *cp, unsigned int base, long long *res);
 210
 211 #define define_strict_strtoux(type, valtype)                            \
 212 int strict_strtou##type(const char *cp, unsigned int base, valtype *res)\
 213 {                                                                       \
 214         char *tail;                                                     \
 215         valtype val;                                                    \
 216         size_t len;                                                     \
 217                                                                         \
 218         *res = 0;                                                       \
 219         len = strlen(cp);                                               \
 220         if (len == 0)                                                   \
 221                 return -EINVAL;                                         \
 222                                                                         \
 223         val = simple_strtoul(cp, &tail, base);                          \
 224         if ((*tail == '\0') ||                                          \
 225                 ((len == (size_t)(tail - cp) + 1) && (*tail == '\n'))) {\
 226                 *res = val;                                             \
 227                 return 0;                                               \
 228         }                                                               \
 229                                                                         \
 230         return -EINVAL;                                                 \
 231 }                                                                       \
 232
 233 #define define_strict_strtox(type, valtype)                             \
 234 int strict_strto##type(const char *cp, unsigned int base, valtype *res) \
 235 {                                                                       \
 236         int ret;                                                        \
 237         if (*cp == '-') {                                               \
 238                 ret = strict_strtou##type(cp+1, base, res);             \
 239                 if (!ret)                                               \
 240                         *res = -(*res);                                 \
 241         } else                                                          \
 242                 ret = strict_strtou##type(cp, base, res);               \
 243                                                                         \
 244         return ret;                                                     \
 245 }                                                                       \
 246
 247 define_strict_strtoux(l, unsigned long)
 248 define_strict_strtox(l, long)
 249 define_strict_strtoux(ll, unsigned long long)
 250 define_strict_strtox(ll, long long)
 251
 252 EXPORT_SYMBOL(strict_strtoul);
 253 EXPORT_SYMBOL(strict_strtol);
 254 EXPORT_SYMBOL(strict_strtoll);
 255 EXPORT_SYMBOL(strict_strtoull);
 256
 257 static int skip_atoi(const char **s)
 258 {
 259         int i=0;
 260
 261         while (isdigit(**s))
 262                 i = i*10 + *((*s)++) - '0';
 263         return i;
 264 }
 265
 266 /* Decimal conversion is by far the most typical, and is used
 267  * for /proc and /sys data. This directly impacts e.g. top performance
 268  * with many processes running. We optimize it for speed
 269  * using code from
 270  * http://www.cs.uiowa.edu/~jones/bcd/decimal.html
 271  * (with permission from the author, Douglas W. Jones). */
 272
 273 /* Formats correctly any integer in [0,99999].
 274  * Outputs from one to five digits depending on input.
 275  * On i386 gcc 4.1.2 -O2: ~250 bytes of code. */
 276 static char* put_dec_trunc(char *buf, unsigned q)
 277 {
 278         unsigned d3, d2, d1, d0;
 279         d1 = (q>>4) & 0xf;
 280         d2 = (q>>8) & 0xf;
 281         d3 = (q>>12);
 282
 283         d0 = 6*(d3 + d2 + d1) + (q & 0xf);
 284         q = (d0 * 0xcd) >> 11;
 285         d0 = d0 - 10*q;
 286         *buf++ = d0 + '0'; /* least significant digit */
 287         d1 = q + 9*d3 + 5*d2 + d1;
 288         if (d1 != 0) {
 289                 q = (d1 * 0xcd) >> 11;
 290                 d1 = d1 - 10*q;
 291                 *buf++ = d1 + '0'; /* next digit */
 292
 293                 d2 = q + 2*d2;
 294                 if ((d2 != 0) || (d3 != 0)) {
 295                         q = (d2 * 0xd) >> 7;
 296                         d2 = d2 - 10*q;
 297                         *buf++ = d2 + '0'; /* next digit */
 298
 299                         d3 = q + 4*d3;
 300                         if (d3 != 0) {
 301                                 q = (d3 * 0xcd) >> 11;
 302                                 d3 = d3 - 10*q;
 303                                 *buf++ = d3 + '0';  /* next digit */
 304                                 if (q != 0)
 305                                         *buf++ = q + '0';  /* most sign. digit */
 306                         }
 307                 }
 308         }
 309         return buf;
 310 }
 311 /* Same with if's removed. Always emits five digits */
 312 static char* put_dec_full(char *buf, unsigned q)
 313 {
 314         /* BTW, if q is in [0,9999], 8-bit ints will be enough, */
 315         /* but anyway, gcc produces better code with full-sized ints */
 316         unsigned d3, d2, d1, d0;
 317         d1 = (q>>4) & 0xf;
 318         d2 = (q>>8) & 0xf;
 319         d3 = (q>>12);
 320
 321         /* Possible ways to approx. divide by 10 */
 322         /* gcc -O2 replaces multiply with shifts and adds */
 323         // (x * 0xcd) >> 11: 11001101 - shorter code than * 0x67 (on i386)
 324         // (x * 0x67) >> 10:  1100111
 325         // (x * 0x34) >> 9:    110100 - same
 326         // (x * 0x1a) >> 8:     11010 - same
 327         // (x * 0x0d) >> 7:      1101 - same, shortest code (on i386)
 328
 329         d0 = 6*(d3 + d2 + d1) + (q & 0xf);
 330         q = (d0 * 0xcd) >> 11;
 331         d0 = d0 - 10*q;
 332         *buf++ = d0 + '0';
 333         d1 = q + 9*d3 + 5*d2 + d1;
 334                 q = (d1 * 0xcd) >> 11;
 335                 d1 = d1 - 10*q;
 336                 *buf++ = d1 + '0';
 337
 338                 d2 = q + 2*d2;
 339                         q = (d2 * 0xd) >> 7;
 340                         d2 = d2 - 10*q;
 341                         *buf++ = d2 + '0';
 342
 343                         d3 = q + 4*d3;
 344                                 q = (d3 * 0xcd) >> 11; /* - shorter code */
 345                                 /* q = (d3 * 0x67) >> 10; - would also work */
 346                                 d3 = d3 - 10*q;
 347                                 *buf++ = d3 + '0';
 348                                         *buf++ = q + '0';
 349         return buf;
 350 }
 351 /* No inlining helps gcc to use registers better */
 352 static noinline char* put_dec(char *buf, unsigned long long num)
 353 {
 354         while (1) {
 355                 unsigned rem;
 356                 if (num < 100000)
 357                         return put_dec_trunc(buf, num);
 358                 rem = do_div(num, 100000);
 359                 buf = put_dec_full(buf, rem);
 360         }
 361 }
 362
 363 #define ZEROPAD 1               /* pad with zero */
 364 #define SIGN    2               /* unsigned/signed long */
 365 #define PLUS    4               /* show plus */
 366 #define SPACE   8               /* space if plus */
 367 #define LEFT    16              /* left justified */
 368 #define SMALL   32              /* Must be 32 == 0x20 */
 369 #define SPECIAL 64              /* 0x */
 370
 371 static char *number(char *buf, char *end, unsigned long long num, int base, int size, int precision, int type)
 372 {
 373         /* we are called with base 8, 10 or 16, only, thus don't need "G..."  */
 374         static const char digits[16] = "0123456789ABCDEF"; /* "GHIJKLMNOPQRSTUVWXYZ"; */
 375
 376         char tmp[66];
 377         char sign;
 378         char locase;
 379         int need_pfx = ((type & SPECIAL) && base != 10);
 380         int i;
 381
 382         /* locase = 0 or 0x20. ORing digits or letters with 'locase'
 383          * produces same digits or (maybe lowercased) letters */
 384         locase = (type & SMALL);
 385         if (type & LEFT)
 386                 type &= ~ZEROPAD;
 387         sign = 0;
 388         if (type & SIGN) {
 389                 if ((signed long long) num < 0) {
 390                         sign = '-';
 391                         num = - (signed long long) num;
 392                         size--;
 393                 } else if (type & PLUS) {
 394                         sign = '+';
 395                         size--;
 396                 } else if (type & SPACE) {
 397                         sign = ' ';
 398                         size--;
 399                 }
 400         }
 401         if (need_pfx) {
 402                 size--;
 403                 if (base == 16)
 404                         size--;
 405         }
 406
 407         /* generate full string in tmp[], in reverse order */
 408         i = 0;
 409         if (num == 0)
 410                 tmp[i++] = '0';
 411         /* Generic code, for any base:
 412         else do {
 413                 tmp[i++] = (digits[do_div(num,base)] | locase);
 414         } while (num != 0);
 415         */
 416         else if (base != 10) { /* 8 or 16 */
 417                 int mask = base - 1;
 418                 int shift = 3;
 419                 if (base == 16) shift = 4;
 420                 do {
 421                         tmp[i++] = (digits[((unsigned char)num) & mask] | locase);
 422                         num >>= shift;
 423                 } while (num);
 424         } else { /* base 10 */
 425                 i = put_dec(tmp, num) - tmp;
 426         }
 427
 428         /* printing 100 using %2d gives "100", not "00" */
 429         if (i > precision)
 430                 precision = i;
 431         /* leading space padding */
 432         size -= precision;
 433         if (!(type & (ZEROPAD+LEFT))) {
 434                 while(--size >= 0) {
 435                         if (buf < end)
 436                                 *buf = ' ';
 437                         ++buf;
 438                 }
 439         }
 440         /* sign */
 441         if (sign) {
 442                 if (buf < end)
 443                         *buf = sign;
 444                 ++buf;
 445         }
 446         /* "0x" / "0" prefix */
 447         if (need_pfx) {
 448                 if (buf < end)
 449                         *buf = '0';
 450                 ++buf;
 451                 if (base == 16) {
 452                         if (buf < end)
 453                                 *buf = ('X' | locase);
 454                         ++buf;
 455                 }
 456         }
 457         /* zero or space padding */
 458         if (!(type & LEFT)) {
 459                 char c = (type & ZEROPAD) ? '0' : ' ';
 460                 while (--size >= 0) {
 461                         if (buf < end)
 462                                 *buf = c;
 463                         ++buf;
 464                 }
 465         }
 466         /* hmm even more zero padding? */
 467         while (i <= --precision) {
 468                 if (buf < end)
 469                         *buf = '0';
 470                 ++buf;
 471         }
 472         /* actual digits of result */
 473         while (--i >= 0) {
 474                 if (buf < end)
 475                         *buf = tmp[i];
 476                 ++buf;
 477         }
 478         /* trailing space padding */
 479         while (--size >= 0) {
 480                 if (buf < end)
 481                         *buf = ' ';
 482                 ++buf;
 483         }
 484         return buf;
 485 }
 486
 487 static char *string(char *buf, char *end, char *s, int field_width, int precision, int flags)
 488 {
 489         int len, i;
 490
 491         if ((unsigned long)s < PAGE_SIZE)
 492                 s = "<NULL>";
 493
 494         len = strnlen(s, precision);
 495
 496         if (!(flags & LEFT)) {
 497                 while (len < field_width--) {
 498                         if (buf < end)
 499                                 *buf = ' ';
 500                         ++buf;
 501                 }
 502         }
 503         for (i = 0; i < len; ++i) {
 504                 if (buf < end)
 505                         *buf = *s;
 506                 ++buf; ++s;
 507         }
 508         while (len < field_width--) {
 509                 if (buf < end)
 510                         *buf = ' ';
 511                 ++buf;
 512         }
 513         return buf;
 514 }
 515
 516 static inline void *dereference_function_descriptor(void *ptr)
 517 {
 518 #if defined(CONFIG_IA64) || defined(CONFIG_PPC64)
 519         void *p;
 520         if (!probe_kernel_address(ptr, p))
 521                 ptr = p;
 522 #endif
 523         return ptr;
 524 }
 525
 526 static char *symbol_string(char *buf, char *end, void *ptr, int field_width, int precision, int flags)
 527 {
 528         unsigned long value = (unsigned long) ptr;
 529 #ifdef CONFIG_KALLSYMS
 530         char sym[KSYM_SYMBOL_LEN];
 531         sprint_symbol(sym, value);
 532         return string(buf, end, sym, field_width, precision, flags);
 533 #else
 534         field_width = 2*sizeof(void *);
 535         flags |= SPECIAL | SMALL | ZEROPAD;
 536         return number(buf, end, value, 16, field_width, precision, flags);
 537 #endif
 538 }
 539
 540 /*
 541  * Show a '%p' thing.  A kernel extension is that the '%p' is followed
 542  * by an extra set of alphanumeric characters that are extended format
 543  * specifiers.
 544  *
 545  * Right now we just handle 'F' (for symbolic Function descriptor pointers)
 546  * and 'S' (for Symbolic direct pointers), but this can easily be
 547  * extended in the future (network address types etc).
 548  *
 549  * The difference between 'S' and 'F' is that on ia64 and ppc64 function
 550  * pointers are really function descriptors, which contain a pointer the
 551  * real address.
 552  */
 553 static char *pointer(const char *fmt, char *buf, char *end, void *ptr, int field_width, int precision, int flags)
 554 {
 555         switch (*fmt) {
 556         case 'F':
 557                 ptr = dereference_function_descriptor(ptr);
 558                 /* Fallthrough */
 559         case 'S':
 560                 return symbol_string(buf, end, ptr, field_width, precision, flags);
 561         }
 562         flags |= SMALL;
 563         if (field_width == -1) {
 564                 field_width = 2*sizeof(void *);
 565                 flags |= ZEROPAD;
 566         }
 567         return number(buf, end, (unsigned long) ptr, 16, field_width, precision, flags);
 568 }
 569
 570 /**
 571  * vsnprintf - Format a string and place it in a buffer
 572  * @buf: The buffer to place the result into
 573  * @size: The size of the buffer, including the trailing null space
 574  * @fmt: The format string to use
 575  * @args: Arguments for the format string
 576  *
 577  * The return value is the number of characters which would
 578  * be generated for the given input, excluding the trailing
 579  * '\0', as per ISO C99. If you want to have the exact
 580  * number of characters written into @buf as return value
 581  * (not including the trailing '\0'), use vscnprintf(). If the
 582  * return is greater than or equal to @size, the resulting
 583  * string is truncated.
 584  *
 585  * Call this function if you are already dealing with a va_list.
 586  * You probably want snprintf() instead.
 587  */
 588 int vsnprintf(char *buf, size_t size, const char *fmt, va_list args)
 589 {
 590         unsigned long long num;
 591         int base;
 592         char *str, *end, c;
 593
 594         int flags;              /* flags to number() */
 595
 596         int field_width;        /* width of output field */
 597         int precision;          /* min. # of digits for integers; max
 598                                    number of chars for from string */
 599         int qualifier;          /* 'h', 'l', or 'L' for integer fields */
 600                                 /* 'z' support added 23/7/1999 S.H.    */
 601                                 /* 'z' changed to 'Z' --davidm 1/25/99 */
 602                                 /* 't' added for ptrdiff_t */
 603
 604         /* Reject out-of-range values early.  Large positive sizes are
 605            used for unknown buffer sizes. */
 606         if (unlikely((int) size < 0)) {
 607                 /* There can be only one.. */
 608                 static char warn = 1;
 609                 WARN_ON(warn);
 610                 warn = 0;
 611                 return 0;
 612         }
 613
 614         str = buf;
 615         end = buf + size;
 616
 617         /* Make sure end is always >= buf */
 618         if (end < buf) {
 619                 end = ((void *)-1);
 620                 size = end - buf;
 621         }
 622
 623         for (; *fmt ; ++fmt) {
 624                 if (*fmt != '%') {
 625                         if (str < end)
 626                                 *str = *fmt;
 627                         ++str;
 628                         continue;
 629                 }
 630
 631                 /* process flags */
 632                 flags = 0;
 633                 repeat:
 634                         ++fmt;          /* this also skips first '%' */
 635                         switch (*fmt) {
 636                                 case '-': flags |= LEFT; goto repeat;
 637                                 case '+': flags |= PLUS; goto repeat;
 638                                 case ' ': flags |= SPACE; goto repeat;
 639                                 case '#': flags |= SPECIAL; goto repeat;
 640                                 case '0': flags |= ZEROPAD; goto repeat;
 641                         }
 642
 643                 /* get field width */
 644                 field_width = -1;
 645                 if (isdigit(*fmt))
 646                         field_width = skip_atoi(&fmt);
 647                 else if (*fmt == '*') {
 648                         ++fmt;
 649                         /* it's the next argument */
 650                         field_width = va_arg(args, int);
 651                         if (field_width < 0) {
 652                                 field_width = -field_width;
 653                                 flags |= LEFT;
 654                         }
 655                 }
 656
 657                 /* get the precision */
 658                 precision = -1;
 659                 if (*fmt == '.') {
 660                         ++fmt;
 661                         if (isdigit(*fmt))
 662                                 precision = skip_atoi(&fmt);
 663                         else if (*fmt == '*') {
 664                                 ++fmt;
 665                                 /* it's the next argument */
 666                                 precision = va_arg(args, int);
 667                         }
 668                         if (precision < 0)
 669                                 precision = 0;
 670                 }
 671
 672                 /* get the conversion qualifier */
 673                 qualifier = -1;
 674                 if (*fmt == 'h' || *fmt == 'l' || *fmt == 'L' ||
 675                     *fmt =='Z' || *fmt == 'z' || *fmt == 't') {
 676                         qualifier = *fmt;
 677                         ++fmt;
 678                         if (qualifier == 'l' && *fmt == 'l') {
 679                                 qualifier = 'L';
 680                                 ++fmt;
 681                         }
 682                 }
 683
 684                 /* default base */
 685                 base = 10;
 686
 687                 switch (*fmt) {
 688                         case 'c':
 689                                 if (!(flags & LEFT)) {
 690                                         while (--field_width > 0) {
 691                                                 if (str < end)
 692                                                         *str = ' ';
 693                                                 ++str;
 694                                         }
 695                                 }
 696                                 c = (unsigned char) va_arg(args, int);
 697                                 if (str < end)
 698                                         *str = c;
 699                                 ++str;
 700                                 while (--field_width > 0) {
 701                                         if (str < end)
 702                                                 *str = ' ';
 703                                         ++str;
 704                                 }
 705                                 continue;
 706
 707                         case 's':
 708                                 str = string(str, end, va_arg(args, char *), field_width, precision, flags);
 709                                 continue;
 710
 711                         case 'p':
 712                                 str = pointer(fmt+1, str, end,
 713                                                 va_arg(args, void *),
 714                                                 field_width, precision, flags);
 715                                 /* Skip all alphanumeric pointer suffixes */
 716                                 while (isalnum(fmt[1]))
 717                                         fmt++;
 718                                 continue;
 719
 720                         case 'n':
 721                                 /* FIXME:
 722                                 * What does C99 say about the overflow case here? */
 723                                 if (qualifier == 'l') {
 724                                         long * ip = va_arg(args, long *);
 725                                         *ip = (str - buf);
 726                                 } else if (qualifier == 'Z' || qualifier == 'z') {
 727                                         size_t * ip = va_arg(args, size_t *);
 728                                         *ip = (str - buf);
 729                                 } else {
 730                                         int * ip = va_arg(args, int *);
 731                                         *ip = (str - buf);
 732                                 }
 733                                 continue;
 734
 735                         case '%':
 736                                 if (str < end)
 737                                         *str = '%';
 738                                 ++str;
 739                                 continue;
 740
 741                                 /* integer number formats - set up the flags and "break" */
 742                         case 'o':
 743                                 base = 8;
 744                                 break;
 745
 746                         case 'x':
 747                                 flags |= SMALL;
 748                         case 'X':
 749                                 base = 16;
 750                                 break;
 751
 752                         case 'd':
 753                         case 'i':
 754                                 flags |= SIGN;
 755                         case 'u':
 756                                 break;
 757
 758                         default:
 759                                 if (str < end)
 760                                         *str = '%';
 761                                 ++str;
 762                                 if (*fmt) {
 763                                         if (str < end)
 764                                                 *str = *fmt;
 765                                         ++str;
 766                                 } else {
 767                                         --fmt;
 768                                 }
 769                                 continue;
 770                 }
 771                 if (qualifier == 'L')
 772                         num = va_arg(args, long long);
 773                 else if (qualifier == 'l') {
 774                         num = va_arg(args, unsigned long);
 775                         if (flags & SIGN)
 776                                 num = (signed long) num;
 777                 } else if (qualifier == 'Z' || qualifier == 'z') {
 778                         num = va_arg(args, size_t);
 779                 } else if (qualifier == 't') {
 780                         num = va_arg(args, ptrdiff_t);
 781                 } else if (qualifier == 'h') {
 782                         num = (unsigned short) va_arg(args, int);
 783                         if (flags & SIGN)
 784                                 num = (signed short) num;
 785                 } else {
 786                         num = va_arg(args, unsigned int);
 787                         if (flags & SIGN)
 788                                 num = (signed int) num;
 789                 }
 790                 str = number(str, end, num, base,
 791                                 field_width, precision, flags);
 792         }
 793         if (size > 0) {
 794                 if (str < end)
 795                         *str = '\0';
 796                 else
 797                         end[-1] = '\0';
 798         }
 799         /* the trailing null byte doesn't count towards the total */
 800         return str-buf;
 801 }
 802
 803 EXPORT_SYMBOL(vsnprintf);
 804
 805 /**
 806  * vscnprintf - Format a string and place it in a buffer
 807  * @buf: The buffer to place the result into
 808  * @size: The size of the buffer, including the trailing null space
 809  * @fmt: The format string to use
 810  * @args: Arguments for the format string
 811  *
 812  * The return value is the number of characters which have been written into
 813  * the @buf not including the trailing '\0'. If @size is <= 0 the function
 814  * returns 0.
 815  *
 816  * Call this function if you are already dealing with a va_list.
 817  * You probably want scnprintf() instead.
 818  */
 819 int vscnprintf(char *buf, size_t size, const char *fmt, va_list args)
 820 {
 821         int i;
 822
 823         i=vsnprintf(buf,size,fmt,args);
 824         return (i >= size) ? (size - 1) : i;
 825 }
 826
 827 EXPORT_SYMBOL(vscnprintf);
 828
 829 /**
 830  * snprintf - Format a string and place it in a buffer
 831  * @buf: The buffer to place the result into
 832  * @size: The size of the buffer, including the trailing null space
 833  * @fmt: The format string to use
 834  * @...: Arguments for the format string
 835  *
 836  * The return value is the number of characters which would be
 837  * generated for the given input, excluding the trailing null,
 838  * as per ISO C99.  If the return is greater than or equal to
 839  * @size, the resulting string is truncated.
 840  */
 841 int snprintf(char * buf, size_t size, const char *fmt, ...)
 842 {
 843         va_list args;
 844         int i;
 845
 846         va_start(args, fmt);
 847         i=vsnprintf(buf,size,fmt,args);
 848         va_end(args);
 849         return i;
 850 }
 851
 852 EXPORT_SYMBOL(snprintf);
 853
 854 /**
 855  * scnprintf - Format a string and place it in a buffer
 856  * @buf: The buffer to place the result into
 857  * @size: The size of the buffer, including the trailing null space
 858  * @fmt: The format string to use
 859  * @...: Arguments for the format string
 860  *
 861  * The return value is the number of characters written into @buf not including
 862  * the trailing '\0'. If @size is <= 0 the function returns 0.
 863  */
 864
 865 int scnprintf(char * buf, size_t size, const char *fmt, ...)
 866 {
 867         va_list args;
 868         int i;
 869
 870         va_start(args, fmt);
 871         i = vsnprintf(buf, size, fmt, args);
 872         va_end(args);
 873         return (i >= size) ? (size - 1) : i;
 874 }
 875 EXPORT_SYMBOL(scnprintf);
 876
 877 /**
 878  * vsprintf - Format a string and place it in a buffer
 879  * @buf: The buffer to place the result into
 880  * @fmt: The format string to use
 881  * @args: Arguments for the format string
 882  *
 883  * The function returns the number of characters written
 884  * into @buf. Use vsnprintf() or vscnprintf() in order to avoid
 885  * buffer overflows.
 886  *
 887  * Call this function if you are already dealing with a va_list.
 888  * You probably want sprintf() instead.
 889  */
 890 int vsprintf(char *buf, const char *fmt, va_list args)
 891 {
 892         return vsnprintf(buf, INT_MAX, fmt, args);
 893 }
 894
 895 EXPORT_SYMBOL(vsprintf);
 896
 897 /**
 898  * sprintf - Format a string and place it in a buffer
 899  * @buf: The buffer to place the result into
 900  * @fmt: The format string to use
 901  * @...: Arguments for the format string
 902  *
 903  * The function returns the number of characters written
 904  * into @buf. Use snprintf() or scnprintf() in order to avoid
 905  * buffer overflows.
 906  */
 907 int sprintf(char * buf, const char *fmt, ...)
 908 {
 909         va_list args;
 910         int i;
 911
 912         va_start(args, fmt);
 913         i=vsnprintf(buf, INT_MAX, fmt, args);
 914         va_end(args);
 915         return i;
 916 }
 917
 918 EXPORT_SYMBOL(sprintf);
 919
 920 /**
 921  * vsscanf - Unformat a buffer into a list of arguments
 922  * @buf:        input buffer
 923  * @fmt:        format of buffer
 924  * @args:       arguments
 925  */
 926 int vsscanf(const char * buf, const char * fmt, va_list args)
 927 {
 928         const char *str = buf;
 929         char *next;
 930         char digit;
 931         int num = 0;
 932         int qualifier;
 933         int base;
 934         int field_width;
 935         int is_sign = 0;
 936
 937         while(*fmt && *str) {
 938                 /* skip any white space in format */
 939                 /* white space in format matchs any amount of
 940                  * white space, including none, in the input.
 941                  */
 942                 if (isspace(*fmt)) {
 943                         while (isspace(*fmt))
 944                                 ++fmt;
 945                         while (isspace(*str))
 946                                 ++str;
 947                 }
 948
 949                 /* anything that is not a conversion must match exactly */
 950                 if (*fmt != '%' && *fmt) {
 951                         if (*fmt++ != *str++)
 952                                 break;
 953                         continue;
 954                 }
 955
 956                 if (!*fmt)
 957                         break;
 958                 ++fmt;
 959
 960                 /* skip this conversion.
 961                  * advance both strings to next white space
 962                  */
 963                 if (*fmt == '*') {
 964                         while (!isspace(*fmt) && *fmt)
 965                                 fmt++;
 966                         while (!isspace(*str) && *str)
 967                                 str++;
 968                         continue;
 969                 }
 970
 971                 /* get field width */
 972                 field_width = -1;
 973                 if (isdigit(*fmt))
 974                         field_width = skip_atoi(&fmt);
 975
 976                 /* get conversion qualifier */
 977                 qualifier = -1;
 978                 if (*fmt == 'h' || *fmt == 'l' || *fmt == 'L' ||
 979                     *fmt == 'Z' || *fmt == 'z') {
 980                         qualifier = *fmt++;
 981                         if (unlikely(qualifier == *fmt)) {
 982                                 if (qualifier == 'h') {
 983                                         qualifier = 'H';
 984                                         fmt++;
 985                                 } else if (qualifier == 'l') {
 986                                         qualifier = 'L';
 987                                         fmt++;
 988                                 }
 989                         }
 990                 }
 991                 base = 10;
 992                 is_sign = 0;
 993
 994                 if (!*fmt || !*str)
 995                         break;
 996
 997                 switch(*fmt++) {
 998                 case 'c':
 999                 {
1000                         char *s = (char *) va_arg(args,char*);
1001                         if (field_width == -1)
1002                                 field_width = 1;
1003                         do {
1004                                 *s++ = *str++;
1005                         } while (--field_width > 0 && *str);
1006                         num++;
1007                 }
1008                 continue;
1009                 case 's':
1010                 {
1011                         char *s = (char *) va_arg(args, char *);
1012                         if(field_width == -1)
1013                                 field_width = INT_MAX;
1014                         /* first, skip leading white space in buffer */
1015                         while (isspace(*str))
1016                                 str++;
1017
1018                         /* now copy until next white space */
1019                         while (*str && !isspace(*str) && field_width--) {
1020                                 *s++ = *str++;
1021                         }
1022                         *s = '\0';
1023                         num++;
1024                 }
1025                 continue;
1026                 case 'n':
1027                         /* return number of characters read so far */
1028                 {
1029                         int *i = (int *)va_arg(args,int*);
1030                         *i = str - buf;
1031                 }
1032                 continue;
1033                 case 'o':
1034                         base = 8;
1035                         break;
1036                 case 'x':
1037                 case 'X':
1038                         base = 16;
1039                         break;
1040                 case 'i':
1041                         base = 0;
1042                 case 'd':
1043                         is_sign = 1;
1044                 case 'u':
1045                         break;
1046                 case '%':
1047                         /* looking for '%' in str */
1048                         if (*str++ != '%')
1049                                 return num;
1050                         continue;
1051                 default:
1052                         /* invalid format; stop here */
1053                         return num;
1054                 }
1055
1056                 /* have some sort of integer conversion.
1057                  * first, skip white space in buffer.
1058                  */
1059                 while (isspace(*str))
1060                         str++;
1061
1062                 digit = *str;
1063                 if (is_sign && digit == '-')
1064                         digit = *(str + 1);
1065
1066                 if (!digit
1067                     || (base == 16 && !isxdigit(digit))
1068                     || (base == 10 && !isdigit(digit))
1069                     || (base == 8 && (!isdigit(digit) || digit > '7'))
1070                     || (base == 0 && !isdigit(digit)))
1071                                 break;
1072
1073                 switch(qualifier) {
1074                 case 'H':       /* that's 'hh' in format */
1075                         if (is_sign) {
1076                                 signed char *s = (signed char *) va_arg(args,signed char *);
1077                                 *s = (signed char) simple_strtol(str,&next,base);
1078                         } else {
1079                                 unsigned char *s = (unsigned char *) va_arg(args, unsigned char *);
1080                                 *s = (unsigned char) simple_strtoul(str, &next, base);
1081                         }
1082                         break;
1083                 case 'h':
1084                         if (is_sign) {
1085                                 short *s = (short *) va_arg(args,short *);
1086                                 *s = (short) simple_strtol(str,&next,base);
1087                         } else {
1088                                 unsigned short *s = (unsigned short *) va_arg(args, unsigned short *);
1089                                 *s = (unsigned short) simple_strtoul(str, &next, base);
1090                         }
1091                         break;
1092                 case 'l':
1093                         if (is_sign) {
1094                                 long *l = (long *) va_arg(args,long *);
1095                                 *l = simple_strtol(str,&next,base);
1096                         } else {
1097                                 unsigned long *l = (unsigned long*) va_arg(args,unsigned long*);
1098                                 *l = simple_strtoul(str,&next,base);
1099                         }
1100                         break;
1101                 case 'L':
1102                         if (is_sign) {
1103                                 long long *l = (long long*) va_arg(args,long long *);
1104                                 *l = simple_strtoll(str,&next,base);
1105                         } else {
1106                                 unsigned long long *l = (unsigned long long*) va_arg(args,unsigned long long*);
1107                                 *l = simple_strtoull(str,&next,base);
1108                         }
1109                         break;
1110                 case 'Z':
1111                 case 'z':
1112                 {
1113                         size_t *s = (size_t*) va_arg(args,size_t*);
1114                         *s = (size_t) simple_strtoul(str,&next,base);
1115                 }
1116                 break;
1117                 default:
1118                         if (is_sign) {
1119                                 int *i = (int *) va_arg(args, int*);
1120                                 *i = (int) simple_strtol(str,&next,base);
1121                         } else {
1122                                 unsigned int *i = (unsigned int*) va_arg(args, unsigned int*);
1123                                 *i = (unsigned int) simple_strtoul(str,&next,base);
1124                         }
1125                         break;
1126                 }
1127                 num++;
1128
1129                 if (!next)
1130                         break;
1131                 str = next;
1132         }
1133
1134         /*
1135          * Now we've come all the way through so either the input string or the
1136          * format ended. In the former case, there can be a %n at the current
1137          * position in the format that needs to be filled.
1138          */
1139         if (*fmt == '%' && *(fmt + 1) == 'n') {
1140                 int *p = (int *)va_arg(args, int *);
1141                 *p = str - buf;
1142         }
1143
1144         return num;
1145 }
1146
1147 EXPORT_SYMBOL(vsscanf);
1148
1149 /**
1150  * sscanf - Unformat a buffer into a list of arguments
1151  * @buf:        input buffer
1152  * @fmt:        formatting of buffer
1153  * @...:        resulting arguments
1154  */
1155 int sscanf(const char * buf, const char * fmt, ...)
1156 {
1157         va_list args;
1158         int i;
1159
1160         va_start(args,fmt);
1161         i = vsscanf(buf,fmt,args);
1162         va_end(args);
1163         return i;
1164 }
1165
1166 EXPORT_SYMBOL(sscanf);