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>       /* for KSYM_SYMBOL_LEN */
  21 #include <linux/types.h>
  22 #include <linux/string.h>
  23 #include <linux/ctype.h>
  24 #include <linux/kernel.h>
  25 #include <linux/kallsyms.h>
  26 #include <linux/math64.h>
  27 #include <linux/uaccess.h>
  28 #include <linux/ioport.h>
  29 #include <net/addrconf.h>
  30
  31 #include <asm/page.h>           /* for PAGE_SIZE */
  32 #include <asm/sections.h>       /* for dereference_function_descriptor() */
  33
  34 #include "kstrtox.h"
  35
  36 /**
  37  * simple_strtoull - convert a string to an unsigned long long
  38  * @cp: The start of the string
  39  * @endp: A pointer to the end of the parsed string will be placed here
  40  * @base: The number base to use
  41  *
  42  * This function is obsolete. Please use kstrtoull instead.
  43  */
  44 unsigned long long simple_strtoull(const char *cp, char **endp, unsigned int base)
  45 {
  46         unsigned long long result;
  47         unsigned int rv;
  48
  49         cp = _parse_integer_fixup_radix(cp, &base);
  50         rv = _parse_integer(cp, base, &result);
  51         /* FIXME */
  52         cp += (rv & ~KSTRTOX_OVERFLOW);
  53
  54         if (endp)
  55                 *endp = (char *)cp;
  56
  57         return result;
  58 }
  59 EXPORT_SYMBOL(simple_strtoull);
  60
  61 /**
  62  * simple_strtoul - convert a string to an unsigned long
  63  * @cp: The start of the string
  64  * @endp: A pointer to the end of the parsed string will be placed here
  65  * @base: The number base to use
  66  *
  67  * This function is obsolete. Please use kstrtoul instead.
  68  */
  69 unsigned long simple_strtoul(const char *cp, char **endp, unsigned int base)
  70 {
  71         return simple_strtoull(cp, endp, base);
  72 }
  73 EXPORT_SYMBOL(simple_strtoul);
  74
  75 /**
  76  * simple_strtol - convert a string to a signed long
  77  * @cp: The start of the string
  78  * @endp: A pointer to the end of the parsed string will be placed here
  79  * @base: The number base to use
  80  *
  81  * This function is obsolete. Please use kstrtol instead.
  82  */
  83 long simple_strtol(const char *cp, char **endp, unsigned int base)
  84 {
  85         if (*cp == '-')
  86                 return -simple_strtoul(cp + 1, endp, base);
  87
  88         return simple_strtoul(cp, endp, base);
  89 }
  90 EXPORT_SYMBOL(simple_strtol);
  91
  92 /**
  93  * simple_strtoll - convert a string to a signed long long
  94  * @cp: The start of the string
  95  * @endp: A pointer to the end of the parsed string will be placed here
  96  * @base: The number base to use
  97  *
  98  * This function is obsolete. Please use kstrtoll instead.
  99  */
 100 long long simple_strtoll(const char *cp, char **endp, unsigned int base)
 101 {
 102         if (*cp == '-')
 103                 return -simple_strtoull(cp + 1, endp, base);
 104
 105         return simple_strtoull(cp, endp, base);
 106 }
 107 EXPORT_SYMBOL(simple_strtoll);
 108
 109 static noinline_for_stack
 110 int skip_atoi(const char **s)
 111 {
 112         int i = 0;
 113
 114         while (isdigit(**s))
 115                 i = i*10 + *((*s)++) - '0';
 116
 117         return i;
 118 }
 119
 120 /* Decimal conversion is by far the most typical, and is used
 121  * for /proc and /sys data. This directly impacts e.g. top performance
 122  * with many processes running. We optimize it for speed
 123  * using ideas described at <http://www.cs.uiowa.edu/~jones/bcd/divide.html>
 124  * (with permission from the author, Douglas W. Jones).
 125  */
 126
 127 #if BITS_PER_LONG != 32 || BITS_PER_LONG_LONG != 64
 128 /* Formats correctly any integer in [0, 999999999] */
 129 static noinline_for_stack
 130 char *put_dec_full9(char *buf, unsigned q)
 131 {
 132         unsigned r;
 133
 134         /*
 135          * Possible ways to approx. divide by 10
 136          * (x * 0x1999999a) >> 32 x < 1073741829 (multiply must be 64-bit)
 137          * (x * 0xcccd) >> 19     x <      81920 (x < 262149 when 64-bit mul)
 138          * (x * 0x6667) >> 18     x <      43699
 139          * (x * 0x3334) >> 17     x <      16389
 140          * (x * 0x199a) >> 16     x <      16389
 141          * (x * 0x0ccd) >> 15     x <      16389
 142          * (x * 0x0667) >> 14     x <       2739
 143          * (x * 0x0334) >> 13     x <       1029
 144          * (x * 0x019a) >> 12     x <       1029
 145          * (x * 0x00cd) >> 11     x <       1029 shorter code than * 0x67 (on i386)
 146          * (x * 0x0067) >> 10     x <        179
 147          * (x * 0x0034) >>  9     x <         69 same
 148          * (x * 0x001a) >>  8     x <         69 same
 149          * (x * 0x000d) >>  7     x <         69 same, shortest code (on i386)
 150          * (x * 0x0007) >>  6     x <         19
 151          * See <http://www.cs.uiowa.edu/~jones/bcd/divide.html>
 152          */
 153         r      = (q * (uint64_t)0x1999999a) >> 32;
 154         *buf++ = (q - 10 * r) + '0'; /* 1 */
 155         q      = (r * (uint64_t)0x1999999a) >> 32;
 156         *buf++ = (r - 10 * q) + '0'; /* 2 */
 157         r      = (q * (uint64_t)0x1999999a) >> 32;
 158         *buf++ = (q - 10 * r) + '0'; /* 3 */
 159         q      = (r * (uint64_t)0x1999999a) >> 32;
 160         *buf++ = (r - 10 * q) + '0'; /* 4 */
 161         r      = (q * (uint64_t)0x1999999a) >> 32;
 162         *buf++ = (q - 10 * r) + '0'; /* 5 */
 163         /* Now value is under 10000, can avoid 64-bit multiply */
 164         q      = (r * 0x199a) >> 16;
 165         *buf++ = (r - 10 * q)  + '0'; /* 6 */
 166         r      = (q * 0xcd) >> 11;
 167         *buf++ = (q - 10 * r)  + '0'; /* 7 */
 168         q      = (r * 0xcd) >> 11;
 169         *buf++ = (r - 10 * q) + '0'; /* 8 */
 170         *buf++ = q + '0'; /* 9 */
 171         return buf;
 172 }
 173 #endif
 174
 175 /* Similar to above but do not pad with zeros.
 176  * Code can be easily arranged to print 9 digits too, but our callers
 177  * always call put_dec_full9() instead when the number has 9 decimal digits.
 178  */
 179 static noinline_for_stack
 180 char *put_dec_trunc8(char *buf, unsigned r)
 181 {
 182         unsigned q;
 183
 184         /* Copy of previous function's body with added early returns */
 185         while (r >= 10000) {
 186                 q = r + '0';
 187                 r  = (r * (uint64_t)0x1999999a) >> 32;
 188                 *buf++ = q - 10*r;
 189         }
 190
 191         q      = (r * 0x199a) >> 16;    /* r <= 9999 */
 192         *buf++ = (r - 10 * q)  + '0';
 193         if (q == 0)
 194                 return buf;
 195         r      = (q * 0xcd) >> 11;      /* q <= 999 */
 196         *buf++ = (q - 10 * r)  + '0';
 197         if (r == 0)
 198                 return buf;
 199         q      = (r * 0xcd) >> 11;      /* r <= 99 */
 200         *buf++ = (r - 10 * q) + '0';
 201         if (q == 0)
 202                 return buf;
 203         *buf++ = q + '0';                /* q <= 9 */
 204         return buf;
 205 }
 206
 207 /* There are two algorithms to print larger numbers.
 208  * One is generic: divide by 1000000000 and repeatedly print
 209  * groups of (up to) 9 digits. It's conceptually simple,
 210  * but requires a (unsigned long long) / 1000000000 division.
 211  *
 212  * Second algorithm splits 64-bit unsigned long long into 16-bit chunks,
 213  * manipulates them cleverly and generates groups of 4 decimal digits.
 214  * It so happens that it does NOT require long long division.
 215  *
 216  * If long is > 32 bits, division of 64-bit values is relatively easy,
 217  * and we will use the first algorithm.
 218  * If long long is > 64 bits (strange architecture with VERY large long long),
 219  * second algorithm can't be used, and we again use the first one.
 220  *
 221  * Else (if long is 32 bits and long long is 64 bits) we use second one.
 222  */
 223
 224 #if BITS_PER_LONG != 32 || BITS_PER_LONG_LONG != 64
 225
 226 /* First algorithm: generic */
 227
 228 static
 229 char *put_dec(char *buf, unsigned long long n)
 230 {
 231         if (n >= 100*1000*1000) {
 232                 while (n >= 1000*1000*1000)
 233                         buf = put_dec_full9(buf, do_div(n, 1000*1000*1000));
 234                 if (n >= 100*1000*1000)
 235                         return put_dec_full9(buf, n);
 236         }
 237         return put_dec_trunc8(buf, n);
 238 }
 239
 240 #else
 241
 242 /* Second algorithm: valid only for 64-bit long longs */
 243
 244 /* See comment in put_dec_full9 for choice of constants */
 245 static noinline_for_stack
 246 void put_dec_full4(char *buf, unsigned q)
 247 {
 248         unsigned r;
 249         r      = (q * 0xccd) >> 15;
 250         buf[0] = (q - 10 * r) + '0';
 251         q      = (r * 0xcd) >> 11;
 252         buf[1] = (r - 10 * q)  + '0';
 253         r      = (q * 0xcd) >> 11;
 254         buf[2] = (q - 10 * r)  + '0';
 255         buf[3] = r + '0';
 256 }
 257
 258 /*
 259  * Call put_dec_full4 on x % 10000, return x / 10000.
 260  * The approximation x/10000 == (x * 0x346DC5D7) >> 43
 261  * holds for all x < 1,128,869,999.  The largest value this
 262  * helper will ever be asked to convert is 1,125,520,955.
 263  * (d1 in the put_dec code, assuming n is all-ones).
 264  */
 265 static
 266 unsigned put_dec_helper4(char *buf, unsigned x)
 267 {
 268         uint32_t q = (x * (uint64_t)0x346DC5D7) >> 43;
 269
 270         put_dec_full4(buf, x - q * 10000);
 271         return q;
 272 }
 273
 274 /* Based on code by Douglas W. Jones found at
 275  * <http://www.cs.uiowa.edu/~jones/bcd/decimal.html#sixtyfour>
 276  * (with permission from the author).
 277  * Performs no 64-bit division and hence should be fast on 32-bit machines.
 278  */
 279 static
 280 char *put_dec(char *buf, unsigned long long n)
 281 {
 282         uint32_t d3, d2, d1, q, h;
 283
 284         if (n < 100*1000*1000)
 285                 return put_dec_trunc8(buf, n);
 286
 287         d1  = ((uint32_t)n >> 16); /* implicit "& 0xffff" */
 288         h   = (n >> 32);
 289         d2  = (h      ) & 0xffff;
 290         d3  = (h >> 16); /* implicit "& 0xffff" */
 291
 292         q   = 656 * d3 + 7296 * d2 + 5536 * d1 + ((uint32_t)n & 0xffff);
 293         q = put_dec_helper4(buf, q);
 294
 295         q += 7671 * d3 + 9496 * d2 + 6 * d1;
 296         q = put_dec_helper4(buf+4, q);
 297
 298         q += 4749 * d3 + 42 * d2;
 299         q = put_dec_helper4(buf+8, q);
 300
 301         q += 281 * d3;
 302         buf += 12;
 303         if (q)
 304                 buf = put_dec_trunc8(buf, q);
 305         else while (buf[-1] == '0')
 306                 --buf;
 307
 308         return buf;
 309 }
 310
 311 #endif
 312
 313 /*
 314  * Convert passed number to decimal string.
 315  * Returns the length of string.  On buffer overflow, returns 0.
 316  *
 317  * If speed is not important, use snprintf(). It's easy to read the code.
 318  */
 319 int num_to_str(char *buf, int size, unsigned long long num)
 320 {
 321         char tmp[sizeof(num) * 3];
 322         int idx, len;
 323
 324         /* put_dec() may work incorrectly for num = 0 (generate "", not "0") */
 325         if (num <= 9) {
 326                 tmp[0] = '0' + num;
 327                 len = 1;
 328         } else {
 329                 len = put_dec(tmp, num) - tmp;
 330         }
 331
 332         if (len > size)
 333                 return 0;
 334         for (idx = 0; idx < len; ++idx)
 335                 buf[idx] = tmp[len - idx - 1];
 336         return len;
 337 }
 338
 339 #define ZEROPAD 1               /* pad with zero */
 340 #define SIGN    2               /* unsigned/signed long */
 341 #define PLUS    4               /* show plus */
 342 #define SPACE   8               /* space if plus */
 343 #define LEFT    16              /* left justified */
 344 #define SMALL   32              /* use lowercase in hex (must be 32 == 0x20) */
 345 #define SPECIAL 64              /* prefix hex with "0x", octal with "0" */
 346
 347 enum format_type {
 348         FORMAT_TYPE_NONE, /* Just a string part */
 349         FORMAT_TYPE_WIDTH,
 350         FORMAT_TYPE_PRECISION,
 351         FORMAT_TYPE_CHAR,
 352         FORMAT_TYPE_STR,
 353         FORMAT_TYPE_PTR,
 354         FORMAT_TYPE_PERCENT_CHAR,
 355         FORMAT_TYPE_INVALID,
 356         FORMAT_TYPE_LONG_LONG,
 357         FORMAT_TYPE_ULONG,
 358         FORMAT_TYPE_LONG,
 359         FORMAT_TYPE_UBYTE,
 360         FORMAT_TYPE_BYTE,
 361         FORMAT_TYPE_USHORT,
 362         FORMAT_TYPE_SHORT,
 363         FORMAT_TYPE_UINT,
 364         FORMAT_TYPE_INT,
 365         FORMAT_TYPE_NRCHARS,
 366         FORMAT_TYPE_SIZE_T,
 367         FORMAT_TYPE_PTRDIFF
 368 };
 369
 370 struct printf_spec {
 371         u8      type;           /* format_type enum */
 372         u8      flags;          /* flags to number() */
 373         u8      base;           /* number base, 8, 10 or 16 only */
 374         u8      qualifier;      /* number qualifier, one of 'hHlLtzZ' */
 375         s16     field_width;    /* width of output field */
 376         s16     precision;      /* # of digits/chars */
 377 };
 378
 379 static noinline_for_stack
 380 char *number(char *buf, char *end, unsigned long long num,
 381              struct printf_spec spec)
 382 {
 383         /* we are called with base 8, 10 or 16, only, thus don't need "G..."  */
 384         static const char digits[16] = "0123456789ABCDEF"; /* "GHIJKLMNOPQRSTUVWXYZ"; */
 385
 386         char tmp[66];
 387         char sign;
 388         char locase;
 389         int need_pfx = ((spec.flags & SPECIAL) && spec.base != 10);
 390         int i;
 391         bool is_zero = num == 0LL;
 392
 393         /* locase = 0 or 0x20. ORing digits or letters with 'locase'
 394          * produces same digits or (maybe lowercased) letters */
 395         locase = (spec.flags & SMALL);
 396         if (spec.flags & LEFT)
 397                 spec.flags &= ~ZEROPAD;
 398         sign = 0;
 399         if (spec.flags & SIGN) {
 400                 if ((signed long long)num < 0) {
 401                         sign = '-';
 402                         num = -(signed long long)num;
 403                         spec.field_width--;
 404                 } else if (spec.flags & PLUS) {
 405                         sign = '+';
 406                         spec.field_width--;
 407                 } else if (spec.flags & SPACE) {
 408                         sign = ' ';
 409                         spec.field_width--;
 410                 }
 411         }
 412         if (need_pfx) {
 413                 if (spec.base == 16)
 414                         spec.field_width -= 2;
 415                 else if (!is_zero)
 416                         spec.field_width--;
 417         }
 418
 419         /* generate full string in tmp[], in reverse order */
 420         i = 0;
 421         if (num < spec.base)
 422                 tmp[i++] = digits[num] | locase;
 423         /* Generic code, for any base:
 424         else do {
 425                 tmp[i++] = (digits[do_div(num,base)] | locase);
 426         } while (num != 0);
 427         */
 428         else if (spec.base != 10) { /* 8 or 16 */
 429                 int mask = spec.base - 1;
 430                 int shift = 3;
 431
 432                 if (spec.base == 16)
 433                         shift = 4;
 434                 do {
 435                         tmp[i++] = (digits[((unsigned char)num) & mask] | locase);
 436                         num >>= shift;
 437                 } while (num);
 438         } else { /* base 10 */
 439                 i = put_dec(tmp, num) - tmp;
 440         }
 441
 442         /* printing 100 using %2d gives "100", not "00" */
 443         if (i > spec.precision)
 444                 spec.precision = i;
 445         /* leading space padding */
 446         spec.field_width -= spec.precision;
 447         if (!(spec.flags & (ZEROPAD+LEFT))) {
 448                 while (--spec.field_width >= 0) {
 449                         if (buf < end)
 450                                 *buf = ' ';
 451                         ++buf;
 452                 }
 453         }
 454         /* sign */
 455         if (sign) {
 456                 if (buf < end)
 457                         *buf = sign;
 458                 ++buf;
 459         }
 460         /* "0x" / "0" prefix */
 461         if (need_pfx) {
 462                 if (spec.base == 16 || !is_zero) {
 463                         if (buf < end)
 464                                 *buf = '0';
 465                         ++buf;
 466                 }
 467                 if (spec.base == 16) {
 468                         if (buf < end)
 469                                 *buf = ('X' | locase);
 470                         ++buf;
 471                 }
 472         }
 473         /* zero or space padding */
 474         if (!(spec.flags & LEFT)) {
 475                 char c = (spec.flags & ZEROPAD) ? '0' : ' ';
 476                 while (--spec.field_width >= 0) {
 477                         if (buf < end)
 478                                 *buf = c;
 479                         ++buf;
 480                 }
 481         }
 482         /* hmm even more zero padding? */
 483         while (i <= --spec.precision) {
 484                 if (buf < end)
 485                         *buf = '0';
 486                 ++buf;
 487         }
 488         /* actual digits of result */
 489         while (--i >= 0) {
 490                 if (buf < end)
 491                         *buf = tmp[i];
 492                 ++buf;
 493         }
 494         /* trailing space padding */
 495         while (--spec.field_width >= 0) {
 496                 if (buf < end)
 497                         *buf = ' ';
 498                 ++buf;
 499         }
 500
 501         return buf;
 502 }
 503
 504 static noinline_for_stack
 505 char *string(char *buf, char *end, const char *s, struct printf_spec spec)
 506 {
 507         int len, i;
 508
 509         if ((unsigned long)s < PAGE_SIZE)
 510                 s = "(null)";
 511
 512         len = strnlen(s, spec.precision);
 513
 514         if (!(spec.flags & LEFT)) {
 515                 while (len < spec.field_width--) {
 516                         if (buf < end)
 517                                 *buf = ' ';
 518                         ++buf;
 519                 }
 520         }
 521         for (i = 0; i < len; ++i) {
 522                 if (buf < end)
 523                         *buf = *s;
 524                 ++buf; ++s;
 525         }
 526         while (len < spec.field_width--) {
 527                 if (buf < end)
 528                         *buf = ' ';
 529                 ++buf;
 530         }
 531
 532         return buf;
 533 }
 534
 535 static noinline_for_stack
 536 char *symbol_string(char *buf, char *end, void *ptr,
 537                     struct printf_spec spec, char ext)
 538 {
 539         unsigned long value = (unsigned long) ptr;
 540 #ifdef CONFIG_KALLSYMS
 541         char sym[KSYM_SYMBOL_LEN];
 542         if (ext == 'B')
 543                 sprint_backtrace(sym, value);
 544         else if (ext != 'f' && ext != 's')
 545                 sprint_symbol(sym, value);
 546         else
 547                 sprint_symbol_no_offset(sym, value);
 548
 549         return string(buf, end, sym, spec);
 550 #else
 551         spec.field_width = 2 * sizeof(void *);
 552         spec.flags |= SPECIAL | SMALL | ZEROPAD;
 553         spec.base = 16;
 554
 555         return number(buf, end, value, spec);
 556 #endif
 557 }
 558
 559 static noinline_for_stack
 560 char *resource_string(char *buf, char *end, struct resource *res,
 561                       struct printf_spec spec, const char *fmt)
 562 {
 563 #ifndef IO_RSRC_PRINTK_SIZE
 564 #define IO_RSRC_PRINTK_SIZE     6
 565 #endif
 566
 567 #ifndef MEM_RSRC_PRINTK_SIZE
 568 #define MEM_RSRC_PRINTK_SIZE    10
 569 #endif
 570         static const struct printf_spec io_spec = {
 571                 .base = 16,
 572                 .field_width = IO_RSRC_PRINTK_SIZE,
 573                 .precision = -1,
 574                 .flags = SPECIAL | SMALL | ZEROPAD,
 575         };
 576         static const struct printf_spec mem_spec = {
 577                 .base = 16,
 578                 .field_width = MEM_RSRC_PRINTK_SIZE,
 579                 .precision = -1,
 580                 .flags = SPECIAL | SMALL | ZEROPAD,
 581         };
 582         static const struct printf_spec bus_spec = {
 583                 .base = 16,
 584                 .field_width = 2,
 585                 .precision = -1,
 586                 .flags = SMALL | ZEROPAD,
 587         };
 588         static const struct printf_spec dec_spec = {
 589                 .base = 10,
 590                 .precision = -1,
 591                 .flags = 0,
 592         };
 593         static const struct printf_spec str_spec = {
 594                 .field_width = -1,
 595                 .precision = 10,
 596                 .flags = LEFT,
 597         };
 598         static const struct printf_spec flag_spec = {
 599                 .base = 16,
 600                 .precision = -1,
 601                 .flags = SPECIAL | SMALL,
 602         };
 603
 604         /* 32-bit res (sizeof==4): 10 chars in dec, 10 in hex ("0x" + 8)
 605          * 64-bit res (sizeof==8): 20 chars in dec, 18 in hex ("0x" + 16) */
 606 #define RSRC_BUF_SIZE           ((2 * sizeof(resource_size_t)) + 4)
 607 #define FLAG_BUF_SIZE           (2 * sizeof(res->flags))
 608 #define DECODED_BUF_SIZE        sizeof("[mem - 64bit pref window disabled]")
 609 #define RAW_BUF_SIZE            sizeof("[mem - flags 0x]")
 610         char sym[max(2*RSRC_BUF_SIZE + DECODED_BUF_SIZE,
 611                      2*RSRC_BUF_SIZE + FLAG_BUF_SIZE + RAW_BUF_SIZE)];
 612
 613         char *p = sym, *pend = sym + sizeof(sym);
 614         int decode = (fmt[0] == 'R') ? 1 : 0;
 615         const struct printf_spec *specp;
 616
 617         *p++ = '[';
 618         if (res->flags & IORESOURCE_IO) {
 619                 p = string(p, pend, "io  ", str_spec);
 620                 specp = &io_spec;
 621         } else if (res->flags & IORESOURCE_MEM) {
 622                 p = string(p, pend, "mem ", str_spec);
 623                 specp = &mem_spec;
 624         } else if (res->flags & IORESOURCE_IRQ) {
 625                 p = string(p, pend, "irq ", str_spec);
 626                 specp = &dec_spec;
 627         } else if (res->flags & IORESOURCE_DMA) {
 628                 p = string(p, pend, "dma ", str_spec);
 629                 specp = &dec_spec;
 630         } else if (res->flags & IORESOURCE_BUS) {
 631                 p = string(p, pend, "bus ", str_spec);
 632                 specp = &bus_spec;
 633         } else {
 634                 p = string(p, pend, "??? ", str_spec);
 635                 specp = &mem_spec;
 636                 decode = 0;
 637         }
 638         p = number(p, pend, res->start, *specp);
 639         if (res->start != res->end) {
 640                 *p++ = '-';
 641                 p = number(p, pend, res->end, *specp);
 642         }
 643         if (decode) {
 644                 if (res->flags & IORESOURCE_MEM_64)
 645                         p = string(p, pend, " 64bit", str_spec);
 646                 if (res->flags & IORESOURCE_PREFETCH)
 647                         p = string(p, pend, " pref", str_spec);
 648                 if (res->flags & IORESOURCE_WINDOW)
 649                         p = string(p, pend, " window", str_spec);
 650                 if (res->flags & IORESOURCE_DISABLED)
 651                         p = string(p, pend, " disabled", str_spec);
 652         } else {
 653                 p = string(p, pend, " flags ", str_spec);
 654                 p = number(p, pend, res->flags, flag_spec);
 655         }
 656         *p++ = ']';
 657         *p = '\0';
 658
 659         return string(buf, end, sym, spec);
 660 }
 661
 662 static noinline_for_stack
 663 char *hex_string(char *buf, char *end, u8 *addr, struct printf_spec spec,
 664                  const char *fmt)
 665 {
 666         int i, len = 1;         /* if we pass '%ph[CDN]', field witdh remains
 667                                    negative value, fallback to the default */
 668         char separator;
 669
 670         if (spec.field_width == 0)
 671                 /* nothing to print */
 672                 return buf;
 673
 674         if (ZERO_OR_NULL_PTR(addr))
 675                 /* NULL pointer */
 676                 return string(buf, end, NULL, spec);
 677
 678         switch (fmt[1]) {
 679         case 'C':
 680                 separator = ':';
 681                 break;
 682         case 'D':
 683                 separator = '-';
 684                 break;
 685         case 'N':
 686                 separator = 0;
 687                 break;
 688         default:
 689                 separator = ' ';
 690                 break;
 691         }
 692
 693         if (spec.field_width > 0)
 694                 len = min_t(int, spec.field_width, 64);
 695
 696         for (i = 0; i < len && buf < end - 1; i++) {
 697                 buf = hex_byte_pack(buf, addr[i]);
 698
 699                 if (buf < end && separator && i != len - 1)
 700                         *buf++ = separator;
 701         }
 702
 703         return buf;
 704 }
 705
 706 static noinline_for_stack
 707 char *mac_address_string(char *buf, char *end, u8 *addr,
 708                          struct printf_spec spec, const char *fmt)
 709 {
 710         char mac_addr[sizeof("xx:xx:xx:xx:xx:xx")];
 711         char *p = mac_addr;
 712         int i;
 713         char separator;
 714         bool reversed = false;
 715
 716         switch (fmt[1]) {
 717         case 'F':
 718                 separator = '-';
 719                 break;
 720
 721         case 'R':
 722                 reversed = true;
 723                 /* fall through */
 724
 725         default:
 726                 separator = ':';
 727                 break;
 728         }
 729
 730         for (i = 0; i < 6; i++) {
 731                 if (reversed)
 732                         p = hex_byte_pack(p, addr[5 - i]);
 733                 else
 734                         p = hex_byte_pack(p, addr[i]);
 735
 736                 if (fmt[0] == 'M' && i != 5)
 737                         *p++ = separator;
 738         }
 739         *p = '\0';
 740
 741         return string(buf, end, mac_addr, spec);
 742 }
 743
 744 static noinline_for_stack
 745 char *ip4_string(char *p, const u8 *addr, const char *fmt)
 746 {
 747         int i;
 748         bool leading_zeros = (fmt[0] == 'i');
 749         int index;
 750         int step;
 751
 752         switch (fmt[2]) {
 753         case 'h':
 754 #ifdef __BIG_ENDIAN
 755                 index = 0;
 756                 step = 1;
 757 #else
 758                 index = 3;
 759                 step = -1;
 760 #endif
 761                 break;
 762         case 'l':
 763                 index = 3;
 764                 step = -1;
 765                 break;
 766         case 'n':
 767         case 'b':
 768         default:
 769                 index = 0;
 770                 step = 1;
 771                 break;
 772         }
 773         for (i = 0; i < 4; i++) {
 774                 char temp[3];   /* hold each IP quad in reverse order */
 775                 int digits = put_dec_trunc8(temp, addr[index]) - temp;
 776                 if (leading_zeros) {
 777                         if (digits < 3)
 778                                 *p++ = '0';
 779                         if (digits < 2)
 780                                 *p++ = '0';
 781                 }
 782                 /* reverse the digits in the quad */
 783                 while (digits--)
 784                         *p++ = temp[digits];
 785                 if (i < 3)
 786                         *p++ = '.';
 787                 index += step;
 788         }
 789         *p = '\0';
 790
 791         return p;
 792 }
 793
 794 static noinline_for_stack
 795 char *ip6_compressed_string(char *p, const char *addr)
 796 {
 797         int i, j, range;
 798         unsigned char zerolength[8];
 799         int longest = 1;
 800         int colonpos = -1;
 801         u16 word;
 802         u8 hi, lo;
 803         bool needcolon = false;
 804         bool useIPv4;
 805         struct in6_addr in6;
 806
 807         memcpy(&in6, addr, sizeof(struct in6_addr));
 808
 809         useIPv4 = ipv6_addr_v4mapped(&in6) || ipv6_addr_is_isatap(&in6);
 810
 811         memset(zerolength, 0, sizeof(zerolength));
 812
 813         if (useIPv4)
 814                 range = 6;
 815         else
 816                 range = 8;
 817
 818         /* find position of longest 0 run */
 819         for (i = 0; i < range; i++) {
 820                 for (j = i; j < range; j++) {
 821                         if (in6.s6_addr16[j] != 0)
 822                                 break;
 823                         zerolength[i]++;
 824                 }
 825         }
 826         for (i = 0; i < range; i++) {
 827                 if (zerolength[i] > longest) {
 828                         longest = zerolength[i];
 829                         colonpos = i;
 830                 }
 831         }
 832         if (longest == 1)               /* don't compress a single 0 */
 833                 colonpos = -1;
 834
 835         /* emit address */
 836         for (i = 0; i < range; i++) {
 837                 if (i == colonpos) {
 838                         if (needcolon || i == 0)
 839                                 *p++ = ':';
 840                         *p++ = ':';
 841                         needcolon = false;
 842                         i += longest - 1;
 843                         continue;
 844                 }
 845                 if (needcolon) {
 846                         *p++ = ':';
 847                         needcolon = false;
 848                 }
 849                 /* hex u16 without leading 0s */
 850                 word = ntohs(in6.s6_addr16[i]);
 851                 hi = word >> 8;
 852                 lo = word & 0xff;
 853                 if (hi) {
 854                         if (hi > 0x0f)
 855                                 p = hex_byte_pack(p, hi);
 856                         else
 857                                 *p++ = hex_asc_lo(hi);
 858                         p = hex_byte_pack(p, lo);
 859                 }
 860                 else if (lo > 0x0f)
 861                         p = hex_byte_pack(p, lo);
 862                 else
 863                         *p++ = hex_asc_lo(lo);
 864                 needcolon = true;
 865         }
 866
 867         if (useIPv4) {
 868                 if (needcolon)
 869                         *p++ = ':';
 870                 p = ip4_string(p, &in6.s6_addr[12], "I4");
 871         }
 872         *p = '\0';
 873
 874         return p;
 875 }
 876
 877 static noinline_for_stack
 878 char *ip6_string(char *p, const char *addr, const char *fmt)
 879 {
 880         int i;
 881
 882         for (i = 0; i < 8; i++) {
 883                 p = hex_byte_pack(p, *addr++);
 884                 p = hex_byte_pack(p, *addr++);
 885                 if (fmt[0] == 'I' && i != 7)
 886                         *p++ = ':';
 887         }
 888         *p = '\0';
 889
 890         return p;
 891 }
 892
 893 static noinline_for_stack
 894 char *ip6_addr_string(char *buf, char *end, const u8 *addr,
 895                       struct printf_spec spec, const char *fmt)
 896 {
 897         char ip6_addr[sizeof("xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255")];
 898
 899         if (fmt[0] == 'I' && fmt[2] == 'c')
 900                 ip6_compressed_string(ip6_addr, addr);
 901         else
 902                 ip6_string(ip6_addr, addr, fmt);
 903
 904         return string(buf, end, ip6_addr, spec);
 905 }
 906
 907 static noinline_for_stack
 908 char *ip4_addr_string(char *buf, char *end, const u8 *addr,
 909                       struct printf_spec spec, const char *fmt)
 910 {
 911         char ip4_addr[sizeof("255.255.255.255")];
 912
 913         ip4_string(ip4_addr, addr, fmt);
 914
 915         return string(buf, end, ip4_addr, spec);
 916 }
 917
 918 static noinline_for_stack
 919 char *uuid_string(char *buf, char *end, const u8 *addr,
 920                   struct printf_spec spec, const char *fmt)
 921 {
 922         char uuid[sizeof("xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx")];
 923         char *p = uuid;
 924         int i;
 925         static const u8 be[16] = {0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15};
 926         static const u8 le[16] = {3,2,1,0,5,4,7,6,8,9,10,11,12,13,14,15};
 927         const u8 *index = be;
 928         bool uc = false;
 929
 930         switch (*(++fmt)) {
 931         case 'L':
 932                 uc = true;              /* fall-through */
 933         case 'l':
 934                 index = le;
 935                 break;
 936         case 'B':
 937                 uc = true;
 938                 break;
 939         }
 940
 941         for (i = 0; i < 16; i++) {
 942                 p = hex_byte_pack(p, addr[index[i]]);
 943                 switch (i) {
 944                 case 3:
 945                 case 5:
 946                 case 7:
 947                 case 9:
 948                         *p++ = '-';
 949                         break;
 950                 }
 951         }
 952
 953         *p = 0;
 954
 955         if (uc) {
 956                 p = uuid;
 957                 do {
 958                         *p = toupper(*p);
 959                 } while (*(++p));
 960         }
 961
 962         return string(buf, end, uuid, spec);
 963 }
 964
 965 static
 966 char *netdev_feature_string(char *buf, char *end, const u8 *addr,
 967                       struct printf_spec spec)
 968 {
 969         spec.flags |= SPECIAL | SMALL | ZEROPAD;
 970         if (spec.field_width == -1)
 971                 spec.field_width = 2 + 2 * sizeof(netdev_features_t);
 972         spec.base = 16;
 973
 974         return number(buf, end, *(const netdev_features_t *)addr, spec);
 975 }
 976
 977 int kptr_restrict __read_mostly;
 978
 979 /*
 980  * Show a '%p' thing.  A kernel extension is that the '%p' is followed
 981  * by an extra set of alphanumeric characters that are extended format
 982  * specifiers.
 983  *
 984  * Right now we handle:
 985  *
 986  * - 'F' For symbolic function descriptor pointers with offset
 987  * - 'f' For simple symbolic function names without offset
 988  * - 'S' For symbolic direct pointers with offset
 989  * - 's' For symbolic direct pointers without offset
 990  * - 'B' For backtraced symbolic direct pointers with offset
 991  * - 'R' For decoded struct resource, e.g., [mem 0x0-0x1f 64bit pref]
 992  * - 'r' For raw struct resource, e.g., [mem 0x0-0x1f flags 0x201]
 993  * - 'M' For a 6-byte MAC address, it prints the address in the
 994  *       usual colon-separated hex notation
 995  * - 'm' For a 6-byte MAC address, it prints the hex address without colons
 996  * - 'MF' For a 6-byte MAC FDDI address, it prints the address
 997  *       with a dash-separated hex notation
 998  * - '[mM]R' For a 6-byte MAC address, Reverse order (Bluetooth)
 999  * - 'I' [46] for IPv4/IPv6 addresses printed in the usual way
1000  *       IPv4 uses dot-separated decimal without leading 0's (1.2.3.4)
1001  *       IPv6 uses colon separated network-order 16 bit hex with leading 0's
1002  * - 'i' [46] for 'raw' IPv4/IPv6 addresses
1003  *       IPv6 omits the colons (01020304...0f)
1004  *       IPv4 uses dot-separated decimal with leading 0's (010.123.045.006)
1005  * - '[Ii]4[hnbl]' IPv4 addresses in host, network, big or little endian order
1006  * - 'I6c' for IPv6 addresses printed as specified by
1007  *       http://tools.ietf.org/html/rfc5952
1008  * - 'U' For a 16 byte UUID/GUID, it prints the UUID/GUID in the form
1009  *       "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx"
1010  *       Options for %pU are:
1011  *         b big endian lower case hex (default)
1012  *         B big endian UPPER case hex
1013  *         l little endian lower case hex
1014  *         L little endian UPPER case hex
1015  *           big endian output byte order is:
1016  *             [0][1][2][3]-[4][5]-[6][7]-[8][9]-[10][11][12][13][14][15]
1017  *           little endian output byte order is:
1018  *             [3][2][1][0]-[5][4]-[7][6]-[8][9]-[10][11][12][13][14][15]
1019  * - 'V' For a struct va_format which contains a format string * and va_list *,
1020  *       call vsnprintf(->format, *->va_list).
1021  *       Implements a "recursive vsnprintf".
1022  *       Do not use this feature without some mechanism to verify the
1023  *       correctness of the format string and va_list arguments.
1024  * - 'K' For a kernel pointer that should be hidden from unprivileged users
1025  * - 'NF' For a netdev_features_t
1026  * - 'h[CDN]' For a variable-length buffer, it prints it as a hex string with
1027  *            a certain separator (' ' by default):
1028  *              C colon
1029  *              D dash
1030  *              N no separator
1031  *            The maximum supported length is 64 bytes of the input. Consider
1032  *            to use print_hex_dump() for the larger input.
1033  * - 'a' For a phys_addr_t type and its derivative types (passed by reference)
1034  *
1035  * Note: The difference between 'S' and 'F' is that on ia64 and ppc64
1036  * function pointers are really function descriptors, which contain a
1037  * pointer to the real address.
1038  */
1039 static noinline_for_stack
1040 char *pointer(const char *fmt, char *buf, char *end, void *ptr,
1041               struct printf_spec spec)
1042 {
1043         int default_width = 2 * sizeof(void *) + (spec.flags & SPECIAL ? 2 : 0);
1044
1045         if (!ptr && *fmt != 'K') {
1046                 /*
1047                  * Print (null) with the same width as a pointer so it makes
1048                  * tabular output look nice.
1049                  */
1050                 if (spec.field_width == -1)
1051                         spec.field_width = default_width;
1052                 return string(buf, end, "(null)", spec);
1053         }
1054
1055         switch (*fmt) {
1056         case 'F':
1057         case 'f':
1058                 ptr = dereference_function_descriptor(ptr);
1059                 /* Fallthrough */
1060         case 'S':
1061         case 's':
1062         case 'B':
1063                 return symbol_string(buf, end, ptr, spec, *fmt);
1064         case 'R':
1065         case 'r':
1066                 return resource_string(buf, end, ptr, spec, fmt);
1067         case 'h':
1068                 return hex_string(buf, end, ptr, spec, fmt);
1069         case 'M':                       /* Colon separated: 00:01:02:03:04:05 */
1070         case 'm':                       /* Contiguous: 000102030405 */
1071                                         /* [mM]F (FDDI) */
1072                                         /* [mM]R (Reverse order; Bluetooth) */
1073                 return mac_address_string(buf, end, ptr, spec, fmt);
1074         case 'I':                       /* Formatted IP supported
1075                                          * 4:   1.2.3.4
1076                                          * 6:   0001:0203:...:0708
1077                                          * 6c:  1::708 or 1::1.2.3.4
1078                                          */
1079         case 'i':                       /* Contiguous:
1080                                          * 4:   001.002.003.004
1081                                          * 6:   000102...0f
1082                                          */
1083                 switch (fmt[1]) {
1084                 case '6':
1085                         return ip6_addr_string(buf, end, ptr, spec, fmt);
1086                 case '4':
1087                         return ip4_addr_string(buf, end, ptr, spec, fmt);
1088                 }
1089                 break;
1090         case 'U':
1091                 return uuid_string(buf, end, ptr, spec, fmt);
1092         case 'V':
1093                 {
1094                         va_list va;
1095
1096                         va_copy(va, *((struct va_format *)ptr)->va);
1097                         buf += vsnprintf(buf, end > buf ? end - buf : 0,
1098                                          ((struct va_format *)ptr)->fmt, va);
1099                         va_end(va);
1100                         return buf;
1101                 }
1102         case 'K':
1103                 /*
1104                  * %pK cannot be used in IRQ context because its test
1105                  * for CAP_SYSLOG would be meaningless.
1106                  */
1107                 if (kptr_restrict && (in_irq() || in_serving_softirq() ||
1108                                       in_nmi())) {
1109                         if (spec.field_width == -1)
1110                                 spec.field_width = default_width;
1111                         return string(buf, end, "pK-error", spec);
1112                 }
1113                 if (!((kptr_restrict == 0) ||
1114                       (kptr_restrict == 1 &&
1115                        has_capability_noaudit(current, CAP_SYSLOG))))
1116                         ptr = NULL;
1117                 break;
1118         case 'N':
1119                 switch (fmt[1]) {
1120                 case 'F':
1121                         return netdev_feature_string(buf, end, ptr, spec);
1122                 }
1123                 break;
1124         case 'a':
1125                 spec.flags |= SPECIAL | SMALL | ZEROPAD;
1126                 spec.field_width = sizeof(phys_addr_t) * 2 + 2;
1127                 spec.base = 16;
1128                 return number(buf, end,
1129                               (unsigned long long) *((phys_addr_t *)ptr), spec);
1130         }
1131         spec.flags |= SMALL;
1132         if (spec.field_width == -1) {
1133                 spec.field_width = default_width;
1134                 spec.flags |= ZEROPAD;
1135         }
1136         spec.base = 16;
1137
1138         return number(buf, end, (unsigned long) ptr, spec);
1139 }
1140
1141 /*
1142  * Helper function to decode printf style format.
1143  * Each call decode a token from the format and return the
1144  * number of characters read (or likely the delta where it wants
1145  * to go on the next call).
1146  * The decoded token is returned through the parameters
1147  *
1148  * 'h', 'l', or 'L' for integer fields
1149  * 'z' support added 23/7/1999 S.H.
1150  * 'z' changed to 'Z' --davidm 1/25/99
1151  * 't' added for ptrdiff_t
1152  *
1153  * @fmt: the format string
1154  * @type of the token returned
1155  * @flags: various flags such as +, -, # tokens..
1156  * @field_width: overwritten width
1157  * @base: base of the number (octal, hex, ...)
1158  * @precision: precision of a number
1159  * @qualifier: qualifier of a number (long, size_t, ...)
1160  */
1161 static noinline_for_stack
1162 int format_decode(const char *fmt, struct printf_spec *spec)
1163 {
1164         const char *start = fmt;
1165
1166         /* we finished early by reading the field width */
1167         if (spec->type == FORMAT_TYPE_WIDTH) {
1168                 if (spec->field_width < 0) {
1169                         spec->field_width = -spec->field_width;
1170                         spec->flags |= LEFT;
1171                 }
1172                 spec->type = FORMAT_TYPE_NONE;
1173                 goto precision;
1174         }
1175
1176         /* we finished early by reading the precision */
1177         if (spec->type == FORMAT_TYPE_PRECISION) {
1178                 if (spec->precision < 0)
1179                         spec->precision = 0;
1180
1181                 spec->type = FORMAT_TYPE_NONE;
1182                 goto qualifier;
1183         }
1184
1185         /* By default */
1186         spec->type = FORMAT_TYPE_NONE;
1187
1188         for (; *fmt ; ++fmt) {
1189                 if (*fmt == '%')
1190                         break;
1191         }
1192
1193         /* Return the current non-format string */
1194         if (fmt != start || !*fmt)
1195                 return fmt - start;
1196
1197         /* Process flags */
1198         spec->flags = 0;
1199
1200         while (1) { /* this also skips first '%' */
1201                 bool found = true;
1202
1203                 ++fmt;
1204
1205                 switch (*fmt) {
1206                 case '-': spec->flags |= LEFT;    break;
1207                 case '+': spec->flags |= PLUS;    break;
1208                 case ' ': spec->flags |= SPACE;   break;
1209                 case '#': spec->flags |= SPECIAL; break;
1210                 case '0': spec->flags |= ZEROPAD; break;
1211                 default:  found = false;
1212                 }
1213
1214                 if (!found)
1215                         break;
1216         }
1217
1218         /* get field width */
1219         spec->field_width = -1;
1220
1221         if (isdigit(*fmt))
1222                 spec->field_width = skip_atoi(&fmt);
1223         else if (*fmt == '*') {
1224                 /* it's the next argument */
1225                 spec->type = FORMAT_TYPE_WIDTH;
1226                 return ++fmt - start;
1227         }
1228
1229 precision:
1230         /* get the precision */
1231         spec->precision = -1;
1232         if (*fmt == '.') {
1233                 ++fmt;
1234                 if (isdigit(*fmt)) {
1235                         spec->precision = skip_atoi(&fmt);
1236                         if (spec->precision < 0)
1237                                 spec->precision = 0;
1238                 } else if (*fmt == '*') {
1239                         /* it's the next argument */
1240                         spec->type = FORMAT_TYPE_PRECISION;
1241                         return ++fmt - start;
1242                 }
1243         }
1244
1245 qualifier:
1246         /* get the conversion qualifier */
1247         spec->qualifier = -1;
1248         if (*fmt == 'h' || _tolower(*fmt) == 'l' ||
1249             _tolower(*fmt) == 'z' || *fmt == 't') {
1250                 spec->qualifier = *fmt++;
1251                 if (unlikely(spec->qualifier == *fmt)) {
1252                         if (spec->qualifier == 'l') {
1253                                 spec->qualifier = 'L';
1254                                 ++fmt;
1255                         } else if (spec->qualifier == 'h') {
1256                                 spec->qualifier = 'H';
1257                                 ++fmt;
1258                         }
1259                 }
1260         }
1261
1262         /* default base */
1263         spec->base = 10;
1264         switch (*fmt) {
1265         case 'c':
1266                 spec->type = FORMAT_TYPE_CHAR;
1267                 return ++fmt - start;
1268
1269         case 's':
1270                 spec->type = FORMAT_TYPE_STR;
1271                 return ++fmt - start;
1272
1273         case 'p':
1274                 spec->type = FORMAT_TYPE_PTR;
1275                 return fmt - start;
1276                 /* skip alnum */
1277
1278         case 'n':
1279                 spec->type = FORMAT_TYPE_NRCHARS;
1280                 return ++fmt - start;
1281
1282         case '%':
1283                 spec->type = FORMAT_TYPE_PERCENT_CHAR;
1284                 return ++fmt - start;
1285
1286         /* integer number formats - set up the flags and "break" */
1287         case 'o':
1288                 spec->base = 8;
1289                 break;
1290
1291         case 'x':
1292                 spec->flags |= SMALL;
1293
1294         case 'X':
1295                 spec->base = 16;
1296                 break;
1297
1298         case 'd':
1299         case 'i':
1300                 spec->flags |= SIGN;
1301         case 'u':
1302                 break;
1303
1304         default:
1305                 spec->type = FORMAT_TYPE_INVALID;
1306                 return fmt - start;
1307         }
1308
1309         if (spec->qualifier == 'L')
1310                 spec->type = FORMAT_TYPE_LONG_LONG;
1311         else if (spec->qualifier == 'l') {
1312                 if (spec->flags & SIGN)
1313                         spec->type = FORMAT_TYPE_LONG;
1314                 else
1315                         spec->type = FORMAT_TYPE_ULONG;
1316         } else if (_tolower(spec->qualifier) == 'z') {
1317                 spec->type = FORMAT_TYPE_SIZE_T;
1318         } else if (spec->qualifier == 't') {
1319                 spec->type = FORMAT_TYPE_PTRDIFF;
1320         } else if (spec->qualifier == 'H') {
1321                 if (spec->flags & SIGN)
1322                         spec->type = FORMAT_TYPE_BYTE;
1323                 else
1324                         spec->type = FORMAT_TYPE_UBYTE;
1325         } else if (spec->qualifier == 'h') {
1326                 if (spec->flags & SIGN)
1327                         spec->type = FORMAT_TYPE_SHORT;
1328                 else
1329                         spec->type = FORMAT_TYPE_USHORT;
1330         } else {
1331                 if (spec->flags & SIGN)
1332                         spec->type = FORMAT_TYPE_INT;
1333                 else
1334                         spec->type = FORMAT_TYPE_UINT;
1335         }
1336
1337         return ++fmt - start;
1338 }
1339
1340 /**
1341  * vsnprintf - Format a string and place it in a buffer
1342  * @buf: The buffer to place the result into
1343  * @size: The size of the buffer, including the trailing null space
1344  * @fmt: The format string to use
1345  * @args: Arguments for the format string
1346  *
1347  * This function follows C99 vsnprintf, but has some extensions:
1348  * %pS output the name of a text symbol with offset
1349  * %ps output the name of a text symbol without offset
1350  * %pF output the name of a function pointer with its offset
1351  * %pf output the name of a function pointer without its offset
1352  * %pB output the name of a backtrace symbol with its offset
1353  * %pR output the address range in a struct resource with decoded flags
1354  * %pr output the address range in a struct resource with raw flags
1355  * %pM output a 6-byte MAC address with colons
1356  * %pMR output a 6-byte MAC address with colons in reversed order
1357  * %pMF output a 6-byte MAC address with dashes
1358  * %pm output a 6-byte MAC address without colons
1359  * %pmR output a 6-byte MAC address without colons in reversed order
1360  * %pI4 print an IPv4 address without leading zeros
1361  * %pi4 print an IPv4 address with leading zeros
1362  * %pI6 print an IPv6 address with colons
1363  * %pi6 print an IPv6 address without colons
1364  * %pI6c print an IPv6 address as specified by RFC 5952
1365  * %pU[bBlL] print a UUID/GUID in big or little endian using lower or upper
1366  *   case.
1367  * %*ph[CDN] a variable-length hex string with a separator (supports up to 64
1368  *           bytes of the input)
1369  * %n is ignored
1370  *
1371  * ** Please update Documentation/printk-formats.txt when making changes **
1372  *
1373  * The return value is the number of characters which would
1374  * be generated for the given input, excluding the trailing
1375  * '\0', as per ISO C99. If you want to have the exact
1376  * number of characters written into @buf as return value
1377  * (not including the trailing '\0'), use vscnprintf(). If the
1378  * return is greater than or equal to @size, the resulting
1379  * string is truncated.
1380  *
1381  * If you're not already dealing with a va_list consider using snprintf().
1382  */
1383 int vsnprintf(char *buf, size_t size, const char *fmt, va_list args)
1384 {
1385         unsigned long long num;
1386         char *str, *end;
1387         struct printf_spec spec = {0};
1388
1389         /* Reject out-of-range values early.  Large positive sizes are
1390            used for unknown buffer sizes. */
1391         if (WARN_ON_ONCE((int) size < 0))
1392                 return 0;
1393
1394         str = buf;
1395         end = buf + size;
1396
1397         /* Make sure end is always >= buf */
1398         if (end < buf) {
1399                 end = ((void *)-1);
1400                 size = end - buf;
1401         }
1402
1403         while (*fmt) {
1404                 const char *old_fmt = fmt;
1405                 int read = format_decode(fmt, &spec);
1406
1407                 fmt += read;
1408
1409                 switch (spec.type) {
1410                 case FORMAT_TYPE_NONE: {
1411                         int copy = read;
1412                         if (str < end) {
1413                                 if (copy > end - str)
1414                                         copy = end - str;
1415                                 memcpy(str, old_fmt, copy);
1416                         }
1417                         str += read;
1418                         break;
1419                 }
1420
1421                 case FORMAT_TYPE_WIDTH:
1422                         spec.field_width = va_arg(args, int);
1423                         break;
1424
1425                 case FORMAT_TYPE_PRECISION:
1426                         spec.precision = va_arg(args, int);
1427                         break;
1428
1429                 case FORMAT_TYPE_CHAR: {
1430                         char c;
1431
1432                         if (!(spec.flags & LEFT)) {
1433                                 while (--spec.field_width > 0) {
1434                                         if (str < end)
1435                                                 *str = ' ';
1436                                         ++str;
1437
1438                                 }
1439                         }
1440                         c = (unsigned char) va_arg(args, int);
1441                         if (str < end)
1442                                 *str = c;
1443                         ++str;
1444                         while (--spec.field_width > 0) {
1445                                 if (str < end)
1446                                         *str = ' ';
1447                                 ++str;
1448                         }
1449                         break;
1450                 }
1451
1452                 case FORMAT_TYPE_STR:
1453                         str = string(str, end, va_arg(args, char *), spec);
1454                         break;
1455
1456                 case FORMAT_TYPE_PTR:
1457                         str = pointer(fmt+1, str, end, va_arg(args, void *),
1458                                       spec);
1459                         while (isalnum(*fmt))
1460                                 fmt++;
1461                         break;
1462
1463                 case FORMAT_TYPE_PERCENT_CHAR:
1464                         if (str < end)
1465                                 *str = '%';
1466                         ++str;
1467                         break;
1468
1469                 case FORMAT_TYPE_INVALID:
1470                         if (str < end)
1471                                 *str = '%';
1472                         ++str;
1473                         break;
1474
1475                 case FORMAT_TYPE_NRCHARS: {
1476                         u8 qualifier = spec.qualifier;
1477
1478                         if (qualifier == 'l') {
1479                                 long *ip = va_arg(args, long *);
1480                                 *ip = (str - buf);
1481                         } else if (_tolower(qualifier) == 'z') {
1482                                 size_t *ip = va_arg(args, size_t *);
1483                                 *ip = (str - buf);
1484                         } else {
1485                                 int *ip = va_arg(args, int *);
1486                                 *ip = (str - buf);
1487                         }
1488                         break;
1489                 }
1490
1491                 default:
1492                         switch (spec.type) {
1493                         case FORMAT_TYPE_LONG_LONG:
1494                                 num = va_arg(args, long long);
1495                                 break;
1496                         case FORMAT_TYPE_ULONG:
1497                                 num = va_arg(args, unsigned long);
1498                                 break;
1499                         case FORMAT_TYPE_LONG:
1500                                 num = va_arg(args, long);
1501                                 break;
1502                         case FORMAT_TYPE_SIZE_T:
1503                                 if (spec.flags & SIGN)
1504                                         num = va_arg(args, ssize_t);
1505                                 else
1506                                         num = va_arg(args, size_t);
1507                                 break;
1508                         case FORMAT_TYPE_PTRDIFF:
1509                                 num = va_arg(args, ptrdiff_t);
1510                                 break;
1511                         case FORMAT_TYPE_UBYTE:
1512                                 num = (unsigned char) va_arg(args, int);
1513                                 break;
1514                         case FORMAT_TYPE_BYTE:
1515                                 num = (signed char) va_arg(args, int);
1516                                 break;
1517                         case FORMAT_TYPE_USHORT:
1518                                 num = (unsigned short) va_arg(args, int);
1519                                 break;
1520                         case FORMAT_TYPE_SHORT:
1521                                 num = (short) va_arg(args, int);
1522                                 break;
1523                         case FORMAT_TYPE_INT:
1524                                 num = (int) va_arg(args, int);
1525                                 break;
1526                         default:
1527                                 num = va_arg(args, unsigned int);
1528                         }
1529
1530                         str = number(str, end, num, spec);
1531                 }
1532         }
1533
1534         if (size > 0) {
1535                 if (str < end)
1536                         *str = '\0';
1537                 else
1538                         end[-1] = '\0';
1539         }
1540
1541         /* the trailing null byte doesn't count towards the total */
1542         return str-buf;
1543
1544 }
1545 EXPORT_SYMBOL(vsnprintf);
1546
1547 /**
1548  * vscnprintf - Format a string and place it in a buffer
1549  * @buf: The buffer to place the result into
1550  * @size: The size of the buffer, including the trailing null space
1551  * @fmt: The format string to use
1552  * @args: Arguments for the format string
1553  *
1554  * The return value is the number of characters which have been written into
1555  * the @buf not including the trailing '\0'. If @size is == 0 the function
1556  * returns 0.
1557  *
1558  * If you're not already dealing with a va_list consider using scnprintf().
1559  *
1560  * See the vsnprintf() documentation for format string extensions over C99.
1561  */
1562 int vscnprintf(char *buf, size_t size, const char *fmt, va_list args)
1563 {
1564         int i;
1565
1566         i = vsnprintf(buf, size, fmt, args);
1567
1568         if (likely(i < size))
1569                 return i;
1570         if (size != 0)
1571                 return size - 1;
1572         return 0;
1573 }
1574 EXPORT_SYMBOL(vscnprintf);
1575
1576 /**
1577  * snprintf - Format a string and place it in a buffer
1578  * @buf: The buffer to place the result into
1579  * @size: The size of the buffer, including the trailing null space
1580  * @fmt: The format string to use
1581  * @...: Arguments for the format string
1582  *
1583  * The return value is the number of characters which would be
1584  * generated for the given input, excluding the trailing null,
1585  * as per ISO C99.  If the return is greater than or equal to
1586  * @size, the resulting string is truncated.
1587  *
1588  * See the vsnprintf() documentation for format string extensions over C99.
1589  */
1590 int snprintf(char *buf, size_t size, const char *fmt, ...)
1591 {
1592         va_list args;
1593         int i;
1594
1595         va_start(args, fmt);
1596         i = vsnprintf(buf, size, fmt, args);
1597         va_end(args);
1598
1599         return i;
1600 }
1601 EXPORT_SYMBOL(snprintf);
1602
1603 /**
1604  * scnprintf - Format a string and place it in a buffer
1605  * @buf: The buffer to place the result into
1606  * @size: The size of the buffer, including the trailing null space
1607  * @fmt: The format string to use
1608  * @...: Arguments for the format string
1609  *
1610  * The return value is the number of characters written into @buf not including
1611  * the trailing '\0'. If @size is == 0 the function returns 0.
1612  */
1613
1614 int scnprintf(char *buf, size_t size, const char *fmt, ...)
1615 {
1616         va_list args;
1617         int i;
1618
1619         va_start(args, fmt);
1620         i = vscnprintf(buf, size, fmt, args);
1621         va_end(args);
1622
1623         return i;
1624 }
1625 EXPORT_SYMBOL(scnprintf);
1626
1627 /**
1628  * vsprintf - Format a string and place it in a buffer
1629  * @buf: The buffer to place the result into
1630  * @fmt: The format string to use
1631  * @args: Arguments for the format string
1632  *
1633  * The function returns the number of characters written
1634  * into @buf. Use vsnprintf() or vscnprintf() in order to avoid
1635  * buffer overflows.
1636  *
1637  * If you're not already dealing with a va_list consider using sprintf().
1638  *
1639  * See the vsnprintf() documentation for format string extensions over C99.
1640  */
1641 int vsprintf(char *buf, const char *fmt, va_list args)
1642 {
1643         return vsnprintf(buf, INT_MAX, fmt, args);
1644 }
1645 EXPORT_SYMBOL(vsprintf);
1646
1647 /**
1648  * sprintf - Format a string and place it in a buffer
1649  * @buf: The buffer to place the result into
1650  * @fmt: The format string to use
1651  * @...: Arguments for the format string
1652  *
1653  * The function returns the number of characters written
1654  * into @buf. Use snprintf() or scnprintf() in order to avoid
1655  * buffer overflows.
1656  *
1657  * See the vsnprintf() documentation for format string extensions over C99.
1658  */
1659 int sprintf(char *buf, const char *fmt, ...)
1660 {
1661         va_list args;
1662         int i;
1663
1664         va_start(args, fmt);
1665         i = vsnprintf(buf, INT_MAX, fmt, args);
1666         va_end(args);
1667
1668         return i;
1669 }
1670 EXPORT_SYMBOL(sprintf);
1671
1672 #ifdef CONFIG_BINARY_PRINTF
1673 /*
1674  * bprintf service:
1675  * vbin_printf() - VA arguments to binary data
1676  * bstr_printf() - Binary data to text string
1677  */
1678
1679 /**
1680  * vbin_printf - Parse a format string and place args' binary value in a buffer
1681  * @bin_buf: The buffer to place args' binary value
1682  * @size: The size of the buffer(by words(32bits), not characters)
1683  * @fmt: The format string to use
1684  * @args: Arguments for the format string
1685  *
1686  * The format follows C99 vsnprintf, except %n is ignored, and its argument
1687  * is skiped.
1688  *
1689  * The return value is the number of words(32bits) which would be generated for
1690  * the given input.
1691  *
1692  * NOTE:
1693  * If the return value is greater than @size, the resulting bin_buf is NOT
1694  * valid for bstr_printf().
1695  */
1696 int vbin_printf(u32 *bin_buf, size_t size, const char *fmt, va_list args)
1697 {
1698         struct printf_spec spec = {0};
1699         char *str, *end;
1700
1701         str = (char *)bin_buf;
1702         end = (char *)(bin_buf + size);
1703
1704 #define save_arg(type)                                                  \
1705 do {                                                                    \
1706         if (sizeof(type) == 8) {                                        \
1707                 unsigned long long value;                               \
1708                 str = PTR_ALIGN(str, sizeof(u32));                      \
1709                 value = va_arg(args, unsigned long long);               \
1710                 if (str + sizeof(type) <= end) {                        \
1711                         *(u32 *)str = *(u32 *)&value;                   \
1712                         *(u32 *)(str + 4) = *((u32 *)&value + 1);       \
1713                 }                                                       \
1714         } else {                                                        \
1715                 unsigned long value;                                    \
1716                 str = PTR_ALIGN(str, sizeof(type));                     \
1717                 value = va_arg(args, int);                              \
1718                 if (str + sizeof(type) <= end)                          \
1719                         *(typeof(type) *)str = (type)value;             \
1720         }                                                               \
1721         str += sizeof(type);                                            \
1722 } while (0)
1723
1724         while (*fmt) {
1725                 int read = format_decode(fmt, &spec);
1726
1727                 fmt += read;
1728
1729                 switch (spec.type) {
1730                 case FORMAT_TYPE_NONE:
1731                 case FORMAT_TYPE_INVALID:
1732                 case FORMAT_TYPE_PERCENT_CHAR:
1733                         break;
1734
1735                 case FORMAT_TYPE_WIDTH:
1736                 case FORMAT_TYPE_PRECISION:
1737                         save_arg(int);
1738                         break;
1739
1740                 case FORMAT_TYPE_CHAR:
1741                         save_arg(char);
1742                         break;
1743
1744                 case FORMAT_TYPE_STR: {
1745                         const char *save_str = va_arg(args, char *);
1746                         size_t len;
1747
1748                         if ((unsigned long)save_str > (unsigned long)-PAGE_SIZE
1749                                         || (unsigned long)save_str < PAGE_SIZE)
1750                                 save_str = "(null)";
1751                         len = strlen(save_str) + 1;
1752                         if (str + len < end)
1753                                 memcpy(str, save_str, len);
1754                         str += len;
1755                         break;
1756                 }
1757
1758                 case FORMAT_TYPE_PTR:
1759                         save_arg(void *);
1760                         /* skip all alphanumeric pointer suffixes */
1761                         while (isalnum(*fmt))
1762                                 fmt++;
1763                         break;
1764
1765                 case FORMAT_TYPE_NRCHARS: {
1766                         /* skip %n 's argument */
1767                         u8 qualifier = spec.qualifier;
1768                         void *skip_arg;
1769                         if (qualifier == 'l')
1770                                 skip_arg = va_arg(args, long *);
1771                         else if (_tolower(qualifier) == 'z')
1772                                 skip_arg = va_arg(args, size_t *);
1773                         else
1774                                 skip_arg = va_arg(args, int *);
1775                         break;
1776                 }
1777
1778                 default:
1779                         switch (spec.type) {
1780
1781                         case FORMAT_TYPE_LONG_LONG:
1782                                 save_arg(long long);
1783                                 break;
1784                         case FORMAT_TYPE_ULONG:
1785                         case FORMAT_TYPE_LONG:
1786                                 save_arg(unsigned long);
1787                                 break;
1788                         case FORMAT_TYPE_SIZE_T:
1789                                 save_arg(size_t);
1790                                 break;
1791                         case FORMAT_TYPE_PTRDIFF:
1792                                 save_arg(ptrdiff_t);
1793                                 break;
1794                         case FORMAT_TYPE_UBYTE:
1795                         case FORMAT_TYPE_BYTE:
1796                                 save_arg(char);
1797                                 break;
1798                         case FORMAT_TYPE_USHORT:
1799                         case FORMAT_TYPE_SHORT:
1800                                 save_arg(short);
1801                                 break;
1802                         default:
1803                                 save_arg(int);
1804                         }
1805                 }
1806         }
1807
1808         return (u32 *)(PTR_ALIGN(str, sizeof(u32))) - bin_buf;
1809 #undef save_arg
1810 }
1811 EXPORT_SYMBOL_GPL(vbin_printf);
1812
1813 /**
1814  * bstr_printf - Format a string from binary arguments and place it in a buffer
1815  * @buf: The buffer to place the result into
1816  * @size: The size of the buffer, including the trailing null space
1817  * @fmt: The format string to use
1818  * @bin_buf: Binary arguments for the format string
1819  *
1820  * This function like C99 vsnprintf, but the difference is that vsnprintf gets
1821  * arguments from stack, and bstr_printf gets arguments from @bin_buf which is
1822  * a binary buffer that generated by vbin_printf.
1823  *
1824  * The format follows C99 vsnprintf, but has some extensions:
1825  *  see vsnprintf comment for details.
1826  *
1827  * The return value is the number of characters which would
1828  * be generated for the given input, excluding the trailing
1829  * '\0', as per ISO C99. If you want to have the exact
1830  * number of characters written into @buf as return value
1831  * (not including the trailing '\0'), use vscnprintf(). If the
1832  * return is greater than or equal to @size, the resulting
1833  * string is truncated.
1834  */
1835 int bstr_printf(char *buf, size_t size, const char *fmt, const u32 *bin_buf)
1836 {
1837         struct printf_spec spec = {0};
1838         char *str, *end;
1839         const char *args = (const char *)bin_buf;
1840
1841         if (WARN_ON_ONCE((int) size < 0))
1842                 return 0;
1843
1844         str = buf;
1845         end = buf + size;
1846
1847 #define get_arg(type)                                                   \
1848 ({                                                                      \
1849         typeof(type) value;                                             \
1850         if (sizeof(type) == 8) {                                        \
1851                 args = PTR_ALIGN(args, sizeof(u32));                    \
1852                 *(u32 *)&value = *(u32 *)args;                          \
1853                 *((u32 *)&value + 1) = *(u32 *)(args + 4);              \
1854         } else {                                                        \
1855                 args = PTR_ALIGN(args, sizeof(type));                   \
1856                 value = *(typeof(type) *)args;                          \
1857         }                                                               \
1858         args += sizeof(type);                                           \
1859         value;                                                          \
1860 })
1861
1862         /* Make sure end is always >= buf */
1863         if (end < buf) {
1864                 end = ((void *)-1);
1865                 size = end - buf;
1866         }
1867
1868         while (*fmt) {
1869                 const char *old_fmt = fmt;
1870                 int read = format_decode(fmt, &spec);
1871
1872                 fmt += read;
1873
1874                 switch (spec.type) {
1875                 case FORMAT_TYPE_NONE: {
1876                         int copy = read;
1877                         if (str < end) {
1878                                 if (copy > end - str)
1879                                         copy = end - str;
1880                                 memcpy(str, old_fmt, copy);
1881                         }
1882                         str += read;
1883                         break;
1884                 }
1885
1886                 case FORMAT_TYPE_WIDTH:
1887                         spec.field_width = get_arg(int);
1888                         break;
1889
1890                 case FORMAT_TYPE_PRECISION:
1891                         spec.precision = get_arg(int);
1892                         break;
1893
1894                 case FORMAT_TYPE_CHAR: {
1895                         char c;
1896
1897                         if (!(spec.flags & LEFT)) {
1898                                 while (--spec.field_width > 0) {
1899                                         if (str < end)
1900                                                 *str = ' ';
1901                                         ++str;
1902                                 }
1903                         }
1904                         c = (unsigned char) get_arg(char);
1905                         if (str < end)
1906                                 *str = c;
1907                         ++str;
1908                         while (--spec.field_width > 0) {
1909                                 if (str < end)
1910                                         *str = ' ';
1911                                 ++str;
1912                         }
1913                         break;
1914                 }
1915
1916                 case FORMAT_TYPE_STR: {
1917                         const char *str_arg = args;
1918                         args += strlen(str_arg) + 1;
1919                         str = string(str, end, (char *)str_arg, spec);
1920                         break;
1921                 }
1922
1923                 case FORMAT_TYPE_PTR:
1924                         str = pointer(fmt+1, str, end, get_arg(void *), spec);
1925                         while (isalnum(*fmt))
1926                                 fmt++;
1927                         break;
1928
1929                 case FORMAT_TYPE_PERCENT_CHAR:
1930                 case FORMAT_TYPE_INVALID:
1931                         if (str < end)
1932                                 *str = '%';
1933                         ++str;
1934                         break;
1935
1936                 case FORMAT_TYPE_NRCHARS:
1937                         /* skip */
1938                         break;
1939
1940                 default: {
1941                         unsigned long long num;
1942
1943                         switch (spec.type) {
1944
1945                         case FORMAT_TYPE_LONG_LONG:
1946                                 num = get_arg(long long);
1947                                 break;
1948                         case FORMAT_TYPE_ULONG:
1949                         case FORMAT_TYPE_LONG:
1950                                 num = get_arg(unsigned long);
1951                                 break;
1952                         case FORMAT_TYPE_SIZE_T:
1953                                 num = get_arg(size_t);
1954                                 break;
1955                         case FORMAT_TYPE_PTRDIFF:
1956                                 num = get_arg(ptrdiff_t);
1957                                 break;
1958                         case FORMAT_TYPE_UBYTE:
1959                                 num = get_arg(unsigned char);
1960                                 break;
1961                         case FORMAT_TYPE_BYTE:
1962                                 num = get_arg(signed char);
1963                                 break;
1964                         case FORMAT_TYPE_USHORT:
1965                                 num = get_arg(unsigned short);
1966                                 break;
1967                         case FORMAT_TYPE_SHORT:
1968                                 num = get_arg(short);
1969                                 break;
1970                         case FORMAT_TYPE_UINT:
1971                                 num = get_arg(unsigned int);
1972                                 break;
1973                         default:
1974                                 num = get_arg(int);
1975                         }
1976
1977                         str = number(str, end, num, spec);
1978                 } /* default: */
1979                 } /* switch(spec.type) */
1980         } /* while(*fmt) */
1981
1982         if (size > 0) {
1983                 if (str < end)
1984                         *str = '\0';
1985                 else
1986                         end[-1] = '\0';
1987         }
1988
1989 #undef get_arg
1990
1991         /* the trailing null byte doesn't count towards the total */
1992         return str - buf;
1993 }
1994 EXPORT_SYMBOL_GPL(bstr_printf);
1995
1996 /**
1997  * bprintf - Parse a format string and place args' binary value in a buffer
1998  * @bin_buf: The buffer to place args' binary value
1999  * @size: The size of the buffer(by words(32bits), not characters)
2000  * @fmt: The format string to use
2001  * @...: Arguments for the format string
2002  *
2003  * The function returns the number of words(u32) written
2004  * into @bin_buf.
2005  */
2006 int bprintf(u32 *bin_buf, size_t size, const char *fmt, ...)
2007 {
2008         va_list args;
2009         int ret;
2010
2011         va_start(args, fmt);
2012         ret = vbin_printf(bin_buf, size, fmt, args);
2013         va_end(args);
2014
2015         return ret;
2016 }
2017 EXPORT_SYMBOL_GPL(bprintf);
2018
2019 #endif /* CONFIG_BINARY_PRINTF */
2020
2021 /**
2022  * vsscanf - Unformat a buffer into a list of arguments
2023  * @buf:        input buffer
2024  * @fmt:        format of buffer
2025  * @args:       arguments
2026  */
2027 int vsscanf(const char *buf, const char *fmt, va_list args)
2028 {
2029         const char *str = buf;
2030         char *next;
2031         char digit;
2032         int num = 0;
2033         u8 qualifier;
2034         unsigned int base;
2035         union {
2036                 long long s;
2037                 unsigned long long u;
2038         } val;
2039         s16 field_width;
2040         bool is_sign;
2041
2042         while (*fmt) {
2043                 /* skip any white space in format */
2044                 /* white space in format matchs any amount of
2045                  * white space, including none, in the input.
2046                  */
2047                 if (isspace(*fmt)) {
2048                         fmt = skip_spaces(++fmt);
2049                         str = skip_spaces(str);
2050                 }
2051
2052                 /* anything that is not a conversion must match exactly */
2053                 if (*fmt != '%' && *fmt) {
2054                         if (*fmt++ != *str++)
2055                                 break;
2056                         continue;
2057                 }
2058
2059                 if (!*fmt)
2060                         break;
2061                 ++fmt;
2062
2063                 /* skip this conversion.
2064                  * advance both strings to next white space
2065                  */
2066                 if (*fmt == '*') {
2067                         if (!*str)
2068                                 break;
2069                         while (!isspace(*fmt) && *fmt != '%' && *fmt)
2070                                 fmt++;
2071                         while (!isspace(*str) && *str)
2072                                 str++;
2073                         continue;
2074                 }
2075
2076                 /* get field width */
2077                 field_width = -1;
2078                 if (isdigit(*fmt)) {
2079                         field_width = skip_atoi(&fmt);
2080                         if (field_width <= 0)
2081                                 break;
2082                 }
2083
2084                 /* get conversion qualifier */
2085                 qualifier = -1;
2086                 if (*fmt == 'h' || _tolower(*fmt) == 'l' ||
2087                     _tolower(*fmt) == 'z') {
2088                         qualifier = *fmt++;
2089                         if (unlikely(qualifier == *fmt)) {
2090                                 if (qualifier == 'h') {
2091                                         qualifier = 'H';
2092                                         fmt++;
2093                                 } else if (qualifier == 'l') {
2094                                         qualifier = 'L';
2095                                         fmt++;
2096                                 }
2097                         }
2098                 }
2099
2100                 if (!*fmt)
2101                         break;
2102
2103                 if (*fmt == 'n') {
2104                         /* return number of characters read so far */
2105                         *va_arg(args, int *) = str - buf;
2106                         ++fmt;
2107                         continue;
2108                 }
2109
2110                 if (!*str)
2111                         break;
2112
2113                 base = 10;
2114                 is_sign = 0;
2115
2116                 switch (*fmt++) {
2117                 case 'c':
2118                 {
2119                         char *s = (char *)va_arg(args, char*);
2120                         if (field_width == -1)
2121                                 field_width = 1;
2122                         do {
2123                                 *s++ = *str++;
2124                         } while (--field_width > 0 && *str);
2125                         num++;
2126                 }
2127                 continue;
2128                 case 's':
2129                 {
2130                         char *s = (char *)va_arg(args, char *);
2131                         if (field_width == -1)
2132                                 field_width = SHRT_MAX;
2133                         /* first, skip leading white space in buffer */
2134                         str = skip_spaces(str);
2135
2136                         /* now copy until next white space */
2137                         while (*str && !isspace(*str) && field_width--)
2138                                 *s++ = *str++;
2139                         *s = '\0';
2140                         num++;
2141                 }
2142                 continue;
2143                 case 'o':
2144                         base = 8;
2145                         break;
2146                 case 'x':
2147                 case 'X':
2148                         base = 16;
2149                         break;
2150                 case 'i':
2151                         base = 0;
2152                 case 'd':
2153                         is_sign = 1;
2154                 case 'u':
2155                         break;
2156                 case '%':
2157                         /* looking for '%' in str */
2158                         if (*str++ != '%')
2159                                 return num;
2160                         continue;
2161                 default:
2162                         /* invalid format; stop here */
2163                         return num;
2164                 }
2165
2166                 /* have some sort of integer conversion.
2167                  * first, skip white space in buffer.
2168                  */
2169                 str = skip_spaces(str);
2170
2171                 digit = *str;
2172                 if (is_sign && digit == '-')
2173                         digit = *(str + 1);
2174
2175                 if (!digit
2176                     || (base == 16 && !isxdigit(digit))
2177                     || (base == 10 && !isdigit(digit))
2178                     || (base == 8 && (!isdigit(digit) || digit > '7'))
2179                     || (base == 0 && !isdigit(digit)))
2180                         break;
2181
2182                 if (is_sign)
2183                         val.s = qualifier != 'L' ?
2184                                 simple_strtol(str, &next, base) :
2185                                 simple_strtoll(str, &next, base);
2186                 else
2187                         val.u = qualifier != 'L' ?
2188                                 simple_strtoul(str, &next, base) :
2189                                 simple_strtoull(str, &next, base);
2190
2191                 if (field_width > 0 && next - str > field_width) {
2192                         if (base == 0)
2193                                 _parse_integer_fixup_radix(str, &base);
2194                         while (next - str > field_width) {
2195                                 if (is_sign)
2196                                         val.s = div_s64(val.s, base);
2197                                 else
2198                                         val.u = div_u64(val.u, base);
2199                                 --next;
2200                         }
2201                 }
2202
2203                 switch (qualifier) {
2204                 case 'H':       /* that's 'hh' in format */
2205                         if (is_sign)
2206                                 *va_arg(args, signed char *) = val.s;
2207                         else
2208                                 *va_arg(args, unsigned char *) = val.u;
2209                         break;
2210                 case 'h':
2211                         if (is_sign)
2212                                 *va_arg(args, short *) = val.s;
2213                         else
2214                                 *va_arg(args, unsigned short *) = val.u;
2215                         break;
2216                 case 'l':
2217                         if (is_sign)
2218                                 *va_arg(args, long *) = val.s;
2219                         else
2220                                 *va_arg(args, unsigned long *) = val.u;
2221                         break;
2222                 case 'L':
2223                         if (is_sign)
2224                                 *va_arg(args, long long *) = val.s;
2225                         else
2226                                 *va_arg(args, unsigned long long *) = val.u;
2227                         break;
2228                 case 'Z':
2229                 case 'z':
2230                         *va_arg(args, size_t *) = val.u;
2231                         break;
2232                 default:
2233                         if (is_sign)
2234                                 *va_arg(args, int *) = val.s;
2235                         else
2236                                 *va_arg(args, unsigned int *) = val.u;
2237                         break;
2238                 }
2239                 num++;
2240
2241                 if (!next)
2242                         break;
2243                 str = next;
2244         }
2245
2246         return num;
2247 }
2248 EXPORT_SYMBOL(vsscanf);
2249
2250 /**
2251  * sscanf - Unformat a buffer into a list of arguments
2252  * @buf:        input buffer
2253  * @fmt:        formatting of buffer
2254  * @...:        resulting arguments
2255  */
2256 int sscanf(const char *buf, const char *fmt, ...)
2257 {
2258         va_list args;
2259         int i;
2260
2261         va_start(args, fmt);
2262         i = vsscanf(buf, fmt, args);
2263         va_end(args);
2264
2265         return i;
2266 }
2267 EXPORT_SYMBOL(sscanf);