lib/vsprintf.c

   1 /*
   2  *  linux/lib/vsprintf.c
   3  *
   4  *  Copyright (C) 1991, 1992  Linus Torvalds
   5  */
   6
   7 /* vsprintf.c -- Lars Wirzenius & Linus Torvalds. */
   8 /*
   9  * Wirzenius wrote this portably, Torvalds fucked it up :-)
  10  */
  11
  12 /*
  13  * Fri Jul 13 2001 Crutcher Dunnavant <crutcher+kernel@datastacks.com>
  14  * - changed to provide snprintf and vsnprintf functions
  15  * So Feb  1 16:51:32 CET 2004 Juergen Quade <quade@hsnr.de>
  16  * - scnprintf and vscnprintf
  17  */
  18
  19 #include <stdarg.h>
  20 #include <linux/module.h>
  21 #include <linux/types.h>
  22 #include <linux/string.h>
  23 #include <linux/ctype.h>
  24 #include <linux/kernel.h>
  25 #include <linux/kallsyms.h>
  26 #include <linux/uaccess.h>
  27 #include <linux/ioport.h>
  28 #include <net/addrconf.h>
  29
  30 #include <asm/page.h>           /* for PAGE_SIZE */
  31 #include <asm/div64.h>
  32 #include <asm/sections.h>       /* for dereference_function_descriptor() */
  33
  34 /* Works only for digits and letters, but small and fast */
  35 #define TOLOWER(x) ((x) | 0x20)
  36
  37 static unsigned int simple_guess_base(const char *cp)
  38 {
  39         if (cp[0] == '0') {
  40                 if (TOLOWER(cp[1]) == 'x' && isxdigit(cp[2]))
  41                         return 16;
  42                 else
  43                         return 8;
  44         } else {
  45                 return 10;
  46         }
  47 }
  48
  49 /**
  50  * simple_strtoul - convert a string to an unsigned long
  51  * @cp: The start of the string
  52  * @endp: A pointer to the end of the parsed string will be placed here
  53  * @base: The number base to use
  54  */
  55 unsigned long simple_strtoul(const char *cp, char **endp, unsigned int base)
  56 {
  57         unsigned long result = 0;
  58
  59         if (!base)
  60                 base = simple_guess_base(cp);
  61
  62         if (base == 16 && cp[0] == '0' && TOLOWER(cp[1]) == 'x')
  63                 cp += 2;
  64
  65         while (isxdigit(*cp)) {
  66                 unsigned int value;
  67
  68                 value = isdigit(*cp) ? *cp - '0' : TOLOWER(*cp) - 'a' + 10;
  69                 if (value >= base)
  70                         break;
  71                 result = result * base + value;
  72                 cp++;
  73         }
  74
  75         if (endp)
  76                 *endp = (char *)cp;
  77         return result;
  78 }
  79 EXPORT_SYMBOL(simple_strtoul);
  80
  81 /**
  82  * simple_strtol - convert a string to a signed long
  83  * @cp: The start of the string
  84  * @endp: A pointer to the end of the parsed string will be placed here
  85  * @base: The number base to use
  86  */
  87 long simple_strtol(const char *cp, char **endp, unsigned int base)
  88 {
  89         if(*cp == '-')
  90                 return -simple_strtoul(cp + 1, endp, base);
  91         return simple_strtoul(cp, endp, base);
  92 }
  93 EXPORT_SYMBOL(simple_strtol);
  94
  95 /**
  96  * simple_strtoull - convert a string to an unsigned long long
  97  * @cp: The start of the string
  98  * @endp: A pointer to the end of the parsed string will be placed here
  99  * @base: The number base to use
 100  */
 101 unsigned long long simple_strtoull(const char *cp, char **endp, unsigned int base)
 102 {
 103         unsigned long long result = 0;
 104
 105         if (!base)
 106                 base = simple_guess_base(cp);
 107
 108         if (base == 16 && cp[0] == '0' && TOLOWER(cp[1]) == 'x')
 109                 cp += 2;
 110
 111         while (isxdigit(*cp)) {
 112                 unsigned int value;
 113
 114                 value = isdigit(*cp) ? *cp - '0' : TOLOWER(*cp) - 'a' + 10;
 115                 if (value >= base)
 116                         break;
 117                 result = result * base + value;
 118                 cp++;
 119         }
 120
 121         if (endp)
 122                 *endp = (char *)cp;
 123         return result;
 124 }
 125 EXPORT_SYMBOL(simple_strtoull);
 126
 127 /**
 128  * simple_strtoll - convert a string to a signed long long
 129  * @cp: The start of the string
 130  * @endp: A pointer to the end of the parsed string will be placed here
 131  * @base: The number base to use
 132  */
 133 long long simple_strtoll(const char *cp, char **endp, unsigned int base)
 134 {
 135         if(*cp=='-')
 136                 return -simple_strtoull(cp + 1, endp, base);
 137         return simple_strtoull(cp, endp, base);
 138 }
 139
 140 /**
 141  * strict_strtoul - convert a string to an unsigned long strictly
 142  * @cp: The string to be converted
 143  * @base: The number base to use
 144  * @res: The converted result value
 145  *
 146  * strict_strtoul converts a string to an unsigned long only if the
 147  * string is really an unsigned long string, any string containing
 148  * any invalid char at the tail will be rejected and -EINVAL is returned,
 149  * only a newline char at the tail is acceptible because people generally
 150  * change a module parameter in the following way:
 151  *
 152  *      echo 1024 > /sys/module/e1000/parameters/copybreak
 153  *
 154  * echo will append a newline to the tail.
 155  *
 156  * It returns 0 if conversion is successful and *res is set to the converted
 157  * value, otherwise it returns -EINVAL and *res is set to 0.
 158  *
 159  * simple_strtoul just ignores the successive invalid characters and
 160  * return the converted value of prefix part of the string.
 161  */
 162 int strict_strtoul(const char *cp, unsigned int base, unsigned long *res)
 163 {
 164         char *tail;
 165         unsigned long val;
 166         size_t len;
 167
 168         *res = 0;
 169         len = strlen(cp);
 170         if (len == 0)
 171                 return -EINVAL;
 172
 173         val = simple_strtoul(cp, &tail, base);
 174         if (tail == cp)
 175                 return -EINVAL;
 176         if ((*tail == '\0') ||
 177                 ((len == (size_t)(tail - cp) + 1) && (*tail == '\n'))) {
 178                 *res = val;
 179                 return 0;
 180         }
 181
 182         return -EINVAL;
 183 }
 184 EXPORT_SYMBOL(strict_strtoul);
 185
 186 /**
 187  * strict_strtol - convert a string to a long strictly
 188  * @cp: The string to be converted
 189  * @base: The number base to use
 190  * @res: The converted result value
 191  *
 192  * strict_strtol is similiar to strict_strtoul, but it allows the first
 193  * character of a string is '-'.
 194  *
 195  * It returns 0 if conversion is successful and *res is set to the converted
 196  * value, otherwise it returns -EINVAL and *res is set to 0.
 197  */
 198 int strict_strtol(const char *cp, unsigned int base, long *res)
 199 {
 200         int ret;
 201         if (*cp == '-') {
 202                 ret = strict_strtoul(cp + 1, base, (unsigned long *)res);
 203                 if (!ret)
 204                         *res = -(*res);
 205         } else {
 206                 ret = strict_strtoul(cp, base, (unsigned long *)res);
 207         }
 208
 209         return ret;
 210 }
 211 EXPORT_SYMBOL(strict_strtol);
 212
 213 /**
 214  * strict_strtoull - convert a string to an unsigned long long strictly
 215  * @cp: The string to be converted
 216  * @base: The number base to use
 217  * @res: The converted result value
 218  *
 219  * strict_strtoull converts a string to an unsigned long long only if the
 220  * string is really an unsigned long long string, any string containing
 221  * any invalid char at the tail will be rejected and -EINVAL is returned,
 222  * only a newline char at the tail is acceptible because people generally
 223  * change a module parameter in the following way:
 224  *
 225  *      echo 1024 > /sys/module/e1000/parameters/copybreak
 226  *
 227  * echo will append a newline to the tail of the string.
 228  *
 229  * It returns 0 if conversion is successful and *res is set to the converted
 230  * value, otherwise it returns -EINVAL and *res is set to 0.
 231  *
 232  * simple_strtoull just ignores the successive invalid characters and
 233  * return the converted value of prefix part of the string.
 234  */
 235 int strict_strtoull(const char *cp, unsigned int base, unsigned long long *res)
 236 {
 237         char *tail;
 238         unsigned long long val;
 239         size_t len;
 240
 241         *res = 0;
 242         len = strlen(cp);
 243         if (len == 0)
 244                 return -EINVAL;
 245
 246         val = simple_strtoull(cp, &tail, base);
 247         if (tail == cp)
 248                 return -EINVAL;
 249         if ((*tail == '\0') ||
 250                 ((len == (size_t)(tail - cp) + 1) && (*tail == '\n'))) {
 251                 *res = val;
 252                 return 0;
 253         }
 254
 255         return -EINVAL;
 256 }
 257 EXPORT_SYMBOL(strict_strtoull);
 258
 259 /**
 260  * strict_strtoll - convert a string to a long long strictly
 261  * @cp: The string to be converted
 262  * @base: The number base to use
 263  * @res: The converted result value
 264  *
 265  * strict_strtoll is similiar to strict_strtoull, but it allows the first
 266  * character of a string is '-'.
 267  *
 268  * It returns 0 if conversion is successful and *res is set to the converted
 269  * value, otherwise it returns -EINVAL and *res is set to 0.
 270  */
 271 int strict_strtoll(const char *cp, unsigned int base, long long *res)
 272 {
 273         int ret;
 274         if (*cp == '-') {
 275                 ret = strict_strtoull(cp + 1, base, (unsigned long long *)res);
 276                 if (!ret)
 277                         *res = -(*res);
 278         } else {
 279                 ret = strict_strtoull(cp, base, (unsigned long long *)res);
 280         }
 281
 282         return ret;
 283 }
 284 EXPORT_SYMBOL(strict_strtoll);
 285
 286 static int skip_atoi(const char **s)
 287 {
 288         int i=0;
 289
 290         while (isdigit(**s))
 291                 i = i*10 + *((*s)++) - '0';
 292         return i;
 293 }
 294
 295 /* Decimal conversion is by far the most typical, and is used
 296  * for /proc and /sys data. This directly impacts e.g. top performance
 297  * with many processes running. We optimize it for speed
 298  * using code from
 299  * http://www.cs.uiowa.edu/~jones/bcd/decimal.html
 300  * (with permission from the author, Douglas W. Jones). */
 301
 302 /* Formats correctly any integer in [0,99999].
 303  * Outputs from one to five digits depending on input.
 304  * On i386 gcc 4.1.2 -O2: ~250 bytes of code. */
 305 static char* put_dec_trunc(char *buf, unsigned q)
 306 {
 307         unsigned d3, d2, d1, d0;
 308         d1 = (q>>4) & 0xf;
 309         d2 = (q>>8) & 0xf;
 310         d3 = (q>>12);
 311
 312         d0 = 6*(d3 + d2 + d1) + (q & 0xf);
 313         q = (d0 * 0xcd) >> 11;
 314         d0 = d0 - 10*q;
 315         *buf++ = d0 + '0'; /* least significant digit */
 316         d1 = q + 9*d3 + 5*d2 + d1;
 317         if (d1 != 0) {
 318                 q = (d1 * 0xcd) >> 11;
 319                 d1 = d1 - 10*q;
 320                 *buf++ = d1 + '0'; /* next digit */
 321
 322                 d2 = q + 2*d2;
 323                 if ((d2 != 0) || (d3 != 0)) {
 324                         q = (d2 * 0xd) >> 7;
 325                         d2 = d2 - 10*q;
 326                         *buf++ = d2 + '0'; /* next digit */
 327
 328                         d3 = q + 4*d3;
 329                         if (d3 != 0) {
 330                                 q = (d3 * 0xcd) >> 11;
 331                                 d3 = d3 - 10*q;
 332                                 *buf++ = d3 + '0';  /* next digit */
 333                                 if (q != 0)
 334                                         *buf++ = q + '0';  /* most sign. digit */
 335                         }
 336                 }
 337         }
 338         return buf;
 339 }
 340 /* Same with if's removed. Always emits five digits */
 341 static char* put_dec_full(char *buf, unsigned q)
 342 {
 343         /* BTW, if q is in [0,9999], 8-bit ints will be enough, */
 344         /* but anyway, gcc produces better code with full-sized ints */
 345         unsigned d3, d2, d1, d0;
 346         d1 = (q>>4) & 0xf;
 347         d2 = (q>>8) & 0xf;
 348         d3 = (q>>12);
 349
 350         /* Possible ways to approx. divide by 10 */
 351         /* gcc -O2 replaces multiply with shifts and adds */
 352         // (x * 0xcd) >> 11: 11001101 - shorter code than * 0x67 (on i386)
 353         // (x * 0x67) >> 10:  1100111
 354         // (x * 0x34) >> 9:    110100 - same
 355         // (x * 0x1a) >> 8:     11010 - same
 356         // (x * 0x0d) >> 7:      1101 - same, shortest code (on i386)
 357
 358         d0 = 6*(d3 + d2 + d1) + (q & 0xf);
 359         q = (d0 * 0xcd) >> 11;
 360         d0 = d0 - 10*q;
 361         *buf++ = d0 + '0';
 362         d1 = q + 9*d3 + 5*d2 + d1;
 363                 q = (d1 * 0xcd) >> 11;
 364                 d1 = d1 - 10*q;
 365                 *buf++ = d1 + '0';
 366
 367                 d2 = q + 2*d2;
 368                         q = (d2 * 0xd) >> 7;
 369                         d2 = d2 - 10*q;
 370                         *buf++ = d2 + '0';
 371
 372                         d3 = q + 4*d3;
 373                                 q = (d3 * 0xcd) >> 11; /* - shorter code */
 374                                 /* q = (d3 * 0x67) >> 10; - would also work */
 375                                 d3 = d3 - 10*q;
 376                                 *buf++ = d3 + '0';
 377                                         *buf++ = q + '0';
 378         return buf;
 379 }
 380 /* No inlining helps gcc to use registers better */
 381 static noinline char* put_dec(char *buf, unsigned long long num)
 382 {
 383         while (1) {
 384                 unsigned rem;
 385                 if (num < 100000)
 386                         return put_dec_trunc(buf, num);
 387                 rem = do_div(num, 100000);
 388                 buf = put_dec_full(buf, rem);
 389         }
 390 }
 391
 392 #define ZEROPAD 1               /* pad with zero */
 393 #define SIGN    2               /* unsigned/signed long */
 394 #define PLUS    4               /* show plus */
 395 #define SPACE   8               /* space if plus */
 396 #define LEFT    16              /* left justified */
 397 #define SMALL   32              /* Must be 32 == 0x20 */
 398 #define SPECIAL 64              /* 0x */
 399
 400 enum format_type {
 401         FORMAT_TYPE_NONE, /* Just a string part */
 402         FORMAT_TYPE_WIDTH,
 403         FORMAT_TYPE_PRECISION,
 404         FORMAT_TYPE_CHAR,
 405         FORMAT_TYPE_STR,
 406         FORMAT_TYPE_PTR,
 407         FORMAT_TYPE_PERCENT_CHAR,
 408         FORMAT_TYPE_INVALID,
 409         FORMAT_TYPE_LONG_LONG,
 410         FORMAT_TYPE_ULONG,
 411         FORMAT_TYPE_LONG,
 412         FORMAT_TYPE_UBYTE,
 413         FORMAT_TYPE_BYTE,
 414         FORMAT_TYPE_USHORT,
 415         FORMAT_TYPE_SHORT,
 416         FORMAT_TYPE_UINT,
 417         FORMAT_TYPE_INT,
 418         FORMAT_TYPE_NRCHARS,
 419         FORMAT_TYPE_SIZE_T,
 420         FORMAT_TYPE_PTRDIFF
 421 };
 422
 423 struct printf_spec {
 424         enum format_type        type;
 425         int                     flags;          /* flags to number() */
 426         int                     field_width;    /* width of output field */
 427         int                     base;
 428         int                     precision;      /* # of digits/chars */
 429         int                     qualifier;
 430 };
 431
 432 static char *number(char *buf, char *end, unsigned long long num,
 433                         struct printf_spec spec)
 434 {
 435         /* we are called with base 8, 10 or 16, only, thus don't need "G..."  */
 436         static const char digits[16] = "0123456789ABCDEF"; /* "GHIJKLMNOPQRSTUVWXYZ"; */
 437
 438         char tmp[66];
 439         char sign;
 440         char locase;
 441         int need_pfx = ((spec.flags & SPECIAL) && spec.base != 10);
 442         int i;
 443
 444         /* locase = 0 or 0x20. ORing digits or letters with 'locase'
 445          * produces same digits or (maybe lowercased) letters */
 446         locase = (spec.flags & SMALL);
 447         if (spec.flags & LEFT)
 448                 spec.flags &= ~ZEROPAD;
 449         sign = 0;
 450         if (spec.flags & SIGN) {
 451                 if ((signed long long) num < 0) {
 452                         sign = '-';
 453                         num = - (signed long long) num;
 454                         spec.field_width--;
 455                 } else if (spec.flags & PLUS) {
 456                         sign = '+';
 457                         spec.field_width--;
 458                 } else if (spec.flags & SPACE) {
 459                         sign = ' ';
 460                         spec.field_width--;
 461                 }
 462         }
 463         if (need_pfx) {
 464                 spec.field_width--;
 465                 if (spec.base == 16)
 466                         spec.field_width--;
 467         }
 468
 469         /* generate full string in tmp[], in reverse order */
 470         i = 0;
 471         if (num == 0)
 472                 tmp[i++] = '0';
 473         /* Generic code, for any base:
 474         else do {
 475                 tmp[i++] = (digits[do_div(num,base)] | locase);
 476         } while (num != 0);
 477         */
 478         else if (spec.base != 10) { /* 8 or 16 */
 479                 int mask = spec.base - 1;
 480                 int shift = 3;
 481                 if (spec.base == 16) shift = 4;
 482                 do {
 483                         tmp[i++] = (digits[((unsigned char)num) & mask] | locase);
 484                         num >>= shift;
 485                 } while (num);
 486         } else { /* base 10 */
 487                 i = put_dec(tmp, num) - tmp;
 488         }
 489
 490         /* printing 100 using %2d gives "100", not "00" */
 491         if (i > spec.precision)
 492                 spec.precision = i;
 493         /* leading space padding */
 494         spec.field_width -= spec.precision;
 495         if (!(spec.flags & (ZEROPAD+LEFT))) {
 496                 while(--spec.field_width >= 0) {
 497                         if (buf < end)
 498                                 *buf = ' ';
 499                         ++buf;
 500                 }
 501         }
 502         /* sign */
 503         if (sign) {
 504                 if (buf < end)
 505                         *buf = sign;
 506                 ++buf;
 507         }
 508         /* "0x" / "0" prefix */
 509         if (need_pfx) {
 510                 if (buf < end)
 511                         *buf = '0';
 512                 ++buf;
 513                 if (spec.base == 16) {
 514                         if (buf < end)
 515                                 *buf = ('X' | locase);
 516                         ++buf;
 517                 }
 518         }
 519         /* zero or space padding */
 520         if (!(spec.flags & LEFT)) {
 521                 char c = (spec.flags & ZEROPAD) ? '0' : ' ';
 522                 while (--spec.field_width >= 0) {
 523                         if (buf < end)
 524                                 *buf = c;
 525                         ++buf;
 526                 }
 527         }
 528         /* hmm even more zero padding? */
 529         while (i <= --spec.precision) {
 530                 if (buf < end)
 531                         *buf = '0';
 532                 ++buf;
 533         }
 534         /* actual digits of result */
 535         while (--i >= 0) {
 536                 if (buf < end)
 537                         *buf = tmp[i];
 538                 ++buf;
 539         }
 540         /* trailing space padding */
 541         while (--spec.field_width >= 0) {
 542                 if (buf < end)
 543                         *buf = ' ';
 544                 ++buf;
 545         }
 546         return buf;
 547 }
 548
 549 static char *string(char *buf, char *end, char *s, struct printf_spec spec)
 550 {
 551         int len, i;
 552
 553         if ((unsigned long)s < PAGE_SIZE)
 554                 s = "<NULL>";
 555
 556         len = strnlen(s, spec.precision);
 557
 558         if (!(spec.flags & LEFT)) {
 559                 while (len < spec.field_width--) {
 560                         if (buf < end)
 561                                 *buf = ' ';
 562                         ++buf;
 563                 }
 564         }
 565         for (i = 0; i < len; ++i) {
 566                 if (buf < end)
 567                         *buf = *s;
 568                 ++buf; ++s;
 569         }
 570         while (len < spec.field_width--) {
 571                 if (buf < end)
 572                         *buf = ' ';
 573                 ++buf;
 574         }
 575         return buf;
 576 }
 577
 578 static char *symbol_string(char *buf, char *end, void *ptr,
 579                                 struct printf_spec spec, char ext)
 580 {
 581         unsigned long value = (unsigned long) ptr;
 582 #ifdef CONFIG_KALLSYMS
 583         char sym[KSYM_SYMBOL_LEN];
 584         if (ext != 'f' && ext != 's')
 585                 sprint_symbol(sym, value);
 586         else
 587                 kallsyms_lookup(value, NULL, NULL, NULL, sym);
 588         return string(buf, end, sym, spec);
 589 #else
 590         spec.field_width = 2*sizeof(void *);
 591         spec.flags |= SPECIAL | SMALL | ZEROPAD;
 592         spec.base = 16;
 593         return number(buf, end, value, spec);
 594 #endif
 595 }
 596
 597 static char *resource_string(char *buf, char *end, struct resource *res,
 598                                 struct printf_spec spec)
 599 {
 600 #ifndef IO_RSRC_PRINTK_SIZE
 601 #define IO_RSRC_PRINTK_SIZE     4
 602 #endif
 603
 604 #ifndef MEM_RSRC_PRINTK_SIZE
 605 #define MEM_RSRC_PRINTK_SIZE    8
 606 #endif
 607         struct printf_spec num_spec = {
 608                 .base = 16,
 609                 .precision = -1,
 610                 .flags = SPECIAL | SMALL | ZEROPAD,
 611         };
 612         /* room for the actual numbers, the two "0x", -, [, ] and the final zero */
 613         char sym[4*sizeof(resource_size_t) + 8];
 614         char *p = sym, *pend = sym + sizeof(sym);
 615         int size = -1;
 616
 617         if (res->flags & IORESOURCE_IO)
 618                 size = IO_RSRC_PRINTK_SIZE;
 619         else if (res->flags & IORESOURCE_MEM)
 620                 size = MEM_RSRC_PRINTK_SIZE;
 621
 622         *p++ = '[';
 623         num_spec.field_width = size;
 624         p = number(p, pend, res->start, num_spec);
 625         *p++ = '-';
 626         p = number(p, pend, res->end, num_spec);
 627         *p++ = ']';
 628         *p = 0;
 629
 630         return string(buf, end, sym, spec);
 631 }
 632
 633 static char *mac_address_string(char *buf, char *end, u8 *addr,
 634                                 struct printf_spec spec, const char *fmt)
 635 {
 636         char mac_addr[sizeof("xx:xx:xx:xx:xx:xx")];
 637         char *p = mac_addr;
 638         int i;
 639
 640         for (i = 0; i < 6; i++) {
 641                 p = pack_hex_byte(p, addr[i]);
 642                 if (fmt[0] == 'M' && i != 5)
 643                         *p++ = ':';
 644         }
 645         *p = '\0';
 646
 647         return string(buf, end, mac_addr, spec);
 648 }
 649
 650 static char *ip4_string(char *p, const u8 *addr, bool leading_zeros)
 651 {
 652         int i;
 653
 654         for (i = 0; i < 4; i++) {
 655                 char temp[3];   /* hold each IP quad in reverse order */
 656                 int digits = put_dec_trunc(temp, addr[i]) - temp;
 657                 if (leading_zeros) {
 658                         if (digits < 3)
 659                                 *p++ = '0';
 660                         if (digits < 2)
 661                                 *p++ = '0';
 662                 }
 663                 /* reverse the digits in the quad */
 664                 while (digits--)
 665                         *p++ = temp[digits];
 666                 if (i < 3)
 667                         *p++ = '.';
 668         }
 669
 670         *p = '\0';
 671         return p;
 672 }
 673
 674 static char *ip6_compressed_string(char *p, const char *addr)
 675 {
 676         int i;
 677         int j;
 678         int range;
 679         unsigned char zerolength[8];
 680         int longest = 1;
 681         int colonpos = -1;
 682         u16 word;
 683         u8 hi;
 684         u8 lo;
 685         bool needcolon = false;
 686         bool useIPv4;
 687         struct in6_addr in6;
 688
 689         memcpy(&in6, addr, sizeof(struct in6_addr));
 690
 691         useIPv4 = ipv6_addr_v4mapped(&in6) || ipv6_addr_is_isatap(&in6);
 692
 693         memset(zerolength, 0, sizeof(zerolength));
 694
 695         if (useIPv4)
 696                 range = 6;
 697         else
 698                 range = 8;
 699
 700         /* find position of longest 0 run */
 701         for (i = 0; i < range; i++) {
 702                 for (j = i; j < range; j++) {
 703                         if (in6.s6_addr16[j] != 0)
 704                                 break;
 705                         zerolength[i]++;
 706                 }
 707         }
 708         for (i = 0; i < range; i++) {
 709                 if (zerolength[i] > longest) {
 710                         longest = zerolength[i];
 711                         colonpos = i;
 712                 }
 713         }
 714
 715         /* emit address */
 716         for (i = 0; i < range; i++) {
 717                 if (i == colonpos) {
 718                         if (needcolon || i == 0)
 719                                 *p++ = ':';
 720                         *p++ = ':';
 721                         needcolon = false;
 722                         i += longest - 1;
 723                         continue;
 724                 }
 725                 if (needcolon) {
 726                         *p++ = ':';
 727                         needcolon = false;
 728                 }
 729                 /* hex u16 without leading 0s */
 730                 word = ntohs(in6.s6_addr16[i]);
 731                 hi = word >> 8;
 732                 lo = word & 0xff;
 733                 if (hi) {
 734                         if (hi > 0x0f)
 735                                 p = pack_hex_byte(p, hi);
 736                         else
 737                                 *p++ = hex_asc_lo(hi);
 738                 }
 739                 if (hi || lo > 0x0f)
 740                         p = pack_hex_byte(p, lo);
 741                 else
 742                         *p++ = hex_asc_lo(lo);
 743                 needcolon = true;
 744         }
 745
 746         if (useIPv4) {
 747                 if (needcolon)
 748                         *p++ = ':';
 749                 p = ip4_string(p, &in6.s6_addr[12], false);
 750         }
 751
 752         *p = '\0';
 753         return p;
 754 }
 755
 756 static char *ip6_string(char *p, const char *addr, const char *fmt)
 757 {
 758         int i;
 759         for (i = 0; i < 8; i++) {
 760                 p = pack_hex_byte(p, *addr++);
 761                 p = pack_hex_byte(p, *addr++);
 762                 if (fmt[0] == 'I' && i != 7)
 763                         *p++ = ':';
 764         }
 765
 766         *p = '\0';
 767         return p;
 768 }
 769
 770 static char *ip6_addr_string(char *buf, char *end, const u8 *addr,
 771                              struct printf_spec spec, const char *fmt)
 772 {
 773         char ip6_addr[sizeof("xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255")];
 774
 775         if (fmt[0] == 'I' && fmt[2] == 'c')
 776                 ip6_compressed_string(ip6_addr, addr);
 777         else
 778                 ip6_string(ip6_addr, addr, fmt);
 779
 780         return string(buf, end, ip6_addr, spec);
 781 }
 782
 783 static char *ip4_addr_string(char *buf, char *end, const u8 *addr,
 784                              struct printf_spec spec, const char *fmt)
 785 {
 786         char ip4_addr[sizeof("255.255.255.255")];
 787
 788         ip4_string(ip4_addr, addr, fmt[0] == 'i');
 789
 790         return string(buf, end, ip4_addr, spec);
 791 }
 792
 793 static char *uuid_string(char *buf, char *end, const u8 *addr,
 794                          struct printf_spec spec, const char *fmt)
 795 {
 796         char uuid[sizeof("xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx")];
 797         char *p = uuid;
 798         int i;
 799         static const u8 be[16] = {0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15};
 800         static const u8 le[16] = {3,2,1,0,5,4,7,6,8,9,10,11,12,13,14,15};
 801         const u8 *index = be;
 802         bool uc = false;
 803
 804         switch (*(++fmt)) {
 805         case 'L':
 806                 uc = true;              /* fall-through */
 807         case 'l':
 808                 index = le;
 809                 break;
 810         case 'B':
 811                 uc = true;
 812                 break;
 813         }
 814
 815         for (i = 0; i < 16; i++) {
 816                 p = pack_hex_byte(p, addr[index[i]]);
 817                 switch (i) {
 818                 case 3:
 819                 case 5:
 820                 case 7:
 821                 case 9:
 822                         *p++ = '-';
 823                         break;
 824                 }
 825         }
 826
 827         *p = 0;
 828
 829         if (uc) {
 830                 p = uuid;
 831                 do {
 832                         *p = toupper(*p);
 833                 } while (*(++p));
 834         }
 835
 836         return string(buf, end, uuid, spec);
 837 }
 838
 839 /*
 840  * Show a '%p' thing.  A kernel extension is that the '%p' is followed
 841  * by an extra set of alphanumeric characters that are extended format
 842  * specifiers.
 843  *
 844  * Right now we handle:
 845  *
 846  * - 'F' For symbolic function descriptor pointers with offset
 847  * - 'f' For simple symbolic function names without offset
 848  * - 'S' For symbolic direct pointers with offset
 849  * - 's' For symbolic direct pointers without offset
 850  * - 'R' For a struct resource pointer, it prints the range of
 851  *       addresses (not the name nor the flags)
 852  * - 'M' For a 6-byte MAC address, it prints the address in the
 853  *       usual colon-separated hex notation
 854  * - 'm' For a 6-byte MAC address, it prints the hex address without colons
 855  * - 'I' [46] for IPv4/IPv6 addresses printed in the usual way
 856  *       IPv4 uses dot-separated decimal without leading 0's (1.2.3.4)
 857  *       IPv6 uses colon separated network-order 16 bit hex with leading 0's
 858  * - 'i' [46] for 'raw' IPv4/IPv6 addresses
 859  *       IPv6 omits the colons (01020304...0f)
 860  *       IPv4 uses dot-separated decimal with leading 0's (010.123.045.006)
 861  * - 'I6c' for IPv6 addresses printed as specified by
 862  *       http://www.ietf.org/id/draft-kawamura-ipv6-text-representation-03.txt
 863  * - 'U' For a 16 byte UUID/GUID, it prints the UUID/GUID in the form
 864  *       "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx"
 865  *       Options for %pU are:
 866  *         b big endian lower case hex (default)
 867  *         B big endian UPPER case hex
 868  *         l little endian lower case hex
 869  *         L little endian UPPER case hex
 870  *           big endian output byte order is:
 871  *             [0][1][2][3]-[4][5]-[6][7]-[8][9]-[10][11][12][13][14][15]
 872  *           little endian output byte order is:
 873  *             [3][2][1][0]-[5][4]-[7][6]-[8][9]-[10][11][12][13][14][15]
 874  *
 875  * Note: The difference between 'S' and 'F' is that on ia64 and ppc64
 876  * function pointers are really function descriptors, which contain a
 877  * pointer to the real address.
 878  */
 879 static char *pointer(const char *fmt, char *buf, char *end, void *ptr,
 880                         struct printf_spec spec)
 881 {
 882         if (!ptr)
 883                 return string(buf, end, "(null)", spec);
 884
 885         switch (*fmt) {
 886         case 'F':
 887         case 'f':
 888                 ptr = dereference_function_descriptor(ptr);
 889                 /* Fallthrough */
 890         case 'S':
 891         case 's':
 892                 return symbol_string(buf, end, ptr, spec, *fmt);
 893         case 'R':
 894                 return resource_string(buf, end, ptr, spec);
 895         case 'M':                       /* Colon separated: 00:01:02:03:04:05 */
 896         case 'm':                       /* Contiguous: 000102030405 */
 897                 return mac_address_string(buf, end, ptr, spec, fmt);
 898         case 'I':                       /* Formatted IP supported
 899                                          * 4:   1.2.3.4
 900                                          * 6:   0001:0203:...:0708
 901                                          * 6c:  1::708 or 1::1.2.3.4
 902                                          */
 903         case 'i':                       /* Contiguous:
 904                                          * 4:   001.002.003.004
 905                                          * 6:   000102...0f
 906                                          */
 907                 switch (fmt[1]) {
 908                 case '6':
 909                         return ip6_addr_string(buf, end, ptr, spec, fmt);
 910                 case '4':
 911                         return ip4_addr_string(buf, end, ptr, spec, fmt);
 912                 }
 913                 break;
 914         case 'U':
 915                 return uuid_string(buf, end, ptr, spec, fmt);
 916         }
 917         spec.flags |= SMALL;
 918         if (spec.field_width == -1) {
 919                 spec.field_width = 2*sizeof(void *);
 920                 spec.flags |= ZEROPAD;
 921         }
 922         spec.base = 16;
 923
 924         return number(buf, end, (unsigned long) ptr, spec);
 925 }
 926
 927 /*
 928  * Helper function to decode printf style format.
 929  * Each call decode a token from the format and return the
 930  * number of characters read (or likely the delta where it wants
 931  * to go on the next call).
 932  * The decoded token is returned through the parameters
 933  *
 934  * 'h', 'l', or 'L' for integer fields
 935  * 'z' support added 23/7/1999 S.H.
 936  * 'z' changed to 'Z' --davidm 1/25/99
 937  * 't' added for ptrdiff_t
 938  *
 939  * @fmt: the format string
 940  * @type of the token returned
 941  * @flags: various flags such as +, -, # tokens..
 942  * @field_width: overwritten width
 943  * @base: base of the number (octal, hex, ...)
 944  * @precision: precision of a number
 945  * @qualifier: qualifier of a number (long, size_t, ...)
 946  */
 947 static int format_decode(const char *fmt, struct printf_spec *spec)
 948 {
 949         const char *start = fmt;
 950
 951         /* we finished early by reading the field width */
 952         if (spec->type == FORMAT_TYPE_WIDTH) {
 953                 if (spec->field_width < 0) {
 954                         spec->field_width = -spec->field_width;
 955                         spec->flags |= LEFT;
 956                 }
 957                 spec->type = FORMAT_TYPE_NONE;
 958                 goto precision;
 959         }
 960
 961         /* we finished early by reading the precision */
 962         if (spec->type == FORMAT_TYPE_PRECISION) {
 963                 if (spec->precision < 0)
 964                         spec->precision = 0;
 965
 966                 spec->type = FORMAT_TYPE_NONE;
 967                 goto qualifier;
 968         }
 969
 970         /* By default */
 971         spec->type = FORMAT_TYPE_NONE;
 972
 973         for (; *fmt ; ++fmt) {
 974                 if (*fmt == '%')
 975                         break;
 976         }
 977
 978         /* Return the current non-format string */
 979         if (fmt != start || !*fmt)
 980                 return fmt - start;
 981
 982         /* Process flags */
 983         spec->flags = 0;
 984
 985         while (1) { /* this also skips first '%' */
 986                 bool found = true;
 987
 988                 ++fmt;
 989
 990                 switch (*fmt) {
 991                 case '-': spec->flags |= LEFT;    break;
 992                 case '+': spec->flags |= PLUS;    break;
 993                 case ' ': spec->flags |= SPACE;   break;
 994                 case '#': spec->flags |= SPECIAL; break;
 995                 case '0': spec->flags |= ZEROPAD; break;
 996                 default:  found = false;
 997                 }
 998
 999                 if (!found)
1000                         break;
1001         }
1002
1003         /* get field width */
1004         spec->field_width = -1;
1005
1006         if (isdigit(*fmt))
1007                 spec->field_width = skip_atoi(&fmt);
1008         else if (*fmt == '*') {
1009                 /* it's the next argument */
1010                 spec->type = FORMAT_TYPE_WIDTH;
1011                 return ++fmt - start;
1012         }
1013
1014 precision:
1015         /* get the precision */
1016         spec->precision = -1;
1017         if (*fmt == '.') {
1018                 ++fmt;
1019                 if (isdigit(*fmt)) {
1020                         spec->precision = skip_atoi(&fmt);
1021                         if (spec->precision < 0)
1022                                 spec->precision = 0;
1023                 } else if (*fmt == '*') {
1024                         /* it's the next argument */
1025                         spec->type = FORMAT_TYPE_PRECISION;
1026                         return ++fmt - start;
1027                 }
1028         }
1029
1030 qualifier:
1031         /* get the conversion qualifier */
1032         spec->qualifier = -1;
1033         if (*fmt == 'h' || *fmt == 'l' || *fmt == 'L' ||
1034             *fmt == 'Z' || *fmt == 'z' || *fmt == 't') {
1035                 spec->qualifier = *fmt++;
1036                 if (unlikely(spec->qualifier == *fmt)) {
1037                         if (spec->qualifier == 'l') {
1038                                 spec->qualifier = 'L';
1039                                 ++fmt;
1040                         } else if (spec->qualifier == 'h') {
1041                                 spec->qualifier = 'H';
1042                                 ++fmt;
1043                         }
1044                 }
1045         }
1046
1047         /* default base */
1048         spec->base = 10;
1049         switch (*fmt) {
1050         case 'c':
1051                 spec->type = FORMAT_TYPE_CHAR;
1052                 return ++fmt - start;
1053
1054         case 's':
1055                 spec->type = FORMAT_TYPE_STR;
1056                 return ++fmt - start;
1057
1058         case 'p':
1059                 spec->type = FORMAT_TYPE_PTR;
1060                 return fmt - start;
1061                 /* skip alnum */
1062
1063         case 'n':
1064                 spec->type = FORMAT_TYPE_NRCHARS;
1065                 return ++fmt - start;
1066
1067         case '%':
1068                 spec->type = FORMAT_TYPE_PERCENT_CHAR;
1069                 return ++fmt - start;
1070
1071         /* integer number formats - set up the flags and "break" */
1072         case 'o':
1073                 spec->base = 8;
1074                 break;
1075
1076         case 'x':
1077                 spec->flags |= SMALL;
1078
1079         case 'X':
1080                 spec->base = 16;
1081                 break;
1082
1083         case 'd':
1084         case 'i':
1085                 spec->flags |= SIGN;
1086         case 'u':
1087                 break;
1088
1089         default:
1090                 spec->type = FORMAT_TYPE_INVALID;
1091                 return fmt - start;
1092         }
1093
1094         if (spec->qualifier == 'L')
1095                 spec->type = FORMAT_TYPE_LONG_LONG;
1096         else if (spec->qualifier == 'l') {
1097                 if (spec->flags & SIGN)
1098                         spec->type = FORMAT_TYPE_LONG;
1099                 else
1100                         spec->type = FORMAT_TYPE_ULONG;
1101         } else if (spec->qualifier == 'Z' || spec->qualifier == 'z') {
1102                 spec->type = FORMAT_TYPE_SIZE_T;
1103         } else if (spec->qualifier == 't') {
1104                 spec->type = FORMAT_TYPE_PTRDIFF;
1105         } else if (spec->qualifier == 'H') {
1106                 if (spec->flags & SIGN)
1107                         spec->type = FORMAT_TYPE_BYTE;
1108                 else
1109                         spec->type = FORMAT_TYPE_UBYTE;
1110         } else if (spec->qualifier == 'h') {
1111                 if (spec->flags & SIGN)
1112                         spec->type = FORMAT_TYPE_SHORT;
1113                 else
1114                         spec->type = FORMAT_TYPE_USHORT;
1115         } else {
1116                 if (spec->flags & SIGN)
1117                         spec->type = FORMAT_TYPE_INT;
1118                 else
1119                         spec->type = FORMAT_TYPE_UINT;
1120         }
1121
1122         return ++fmt - start;
1123 }
1124
1125 /**
1126  * vsnprintf - Format a string and place it in a buffer
1127  * @buf: The buffer to place the result into
1128  * @size: The size of the buffer, including the trailing null space
1129  * @fmt: The format string to use
1130  * @args: Arguments for the format string
1131  *
1132  * This function follows C99 vsnprintf, but has some extensions:
1133  * %pS output the name of a text symbol with offset
1134  * %ps output the name of a text symbol without offset
1135  * %pF output the name of a function pointer with its offset
1136  * %pf output the name of a function pointer without its offset
1137  * %pR output the address range in a struct resource
1138  * %n is ignored
1139  *
1140  * The return value is the number of characters which would
1141  * be generated for the given input, excluding the trailing
1142  * '\0', as per ISO C99. If you want to have the exact
1143  * number of characters written into @buf as return value
1144  * (not including the trailing '\0'), use vscnprintf(). If the
1145  * return is greater than or equal to @size, the resulting
1146  * string is truncated.
1147  *
1148  * Call this function if you are already dealing with a va_list.
1149  * You probably want snprintf() instead.
1150  */
1151 int vsnprintf(char *buf, size_t size, const char *fmt, va_list args)
1152 {
1153         unsigned long long num;
1154         char *str, *end, c;
1155         int read;
1156         struct printf_spec spec = {0};
1157
1158         /* Reject out-of-range values early.  Large positive sizes are
1159            used for unknown buffer sizes. */
1160         if (WARN_ON_ONCE((int) size < 0))
1161                 return 0;
1162
1163         str = buf;
1164         end = buf + size;
1165
1166         /* Make sure end is always >= buf */
1167         if (end < buf) {
1168                 end = ((void *)-1);
1169                 size = end - buf;
1170         }
1171
1172         while (*fmt) {
1173                 const char *old_fmt = fmt;
1174
1175                 read = format_decode(fmt, &spec);
1176
1177                 fmt += read;
1178
1179                 switch (spec.type) {
1180                 case FORMAT_TYPE_NONE: {
1181                         int copy = read;
1182                         if (str < end) {
1183                                 if (copy > end - str)
1184                                         copy = end - str;
1185                                 memcpy(str, old_fmt, copy);
1186                         }
1187                         str += read;
1188                         break;
1189                 }
1190
1191                 case FORMAT_TYPE_WIDTH:
1192                         spec.field_width = va_arg(args, int);
1193                         break;
1194
1195                 case FORMAT_TYPE_PRECISION:
1196                         spec.precision = va_arg(args, int);
1197                         break;
1198
1199                 case FORMAT_TYPE_CHAR:
1200                         if (!(spec.flags & LEFT)) {
1201                                 while (--spec.field_width > 0) {
1202                                         if (str < end)
1203                                                 *str = ' ';
1204                                         ++str;
1205
1206                                 }
1207                         }
1208                         c = (unsigned char) va_arg(args, int);
1209                         if (str < end)
1210                                 *str = c;
1211                         ++str;
1212                         while (--spec.field_width > 0) {
1213                                 if (str < end)
1214                                         *str = ' ';
1215                                 ++str;
1216                         }
1217                         break;
1218
1219                 case FORMAT_TYPE_STR:
1220                         str = string(str, end, va_arg(args, char *), spec);
1221                         break;
1222
1223                 case FORMAT_TYPE_PTR:
1224                         str = pointer(fmt+1, str, end, va_arg(args, void *),
1225                                       spec);
1226                         while (isalnum(*fmt))
1227                                 fmt++;
1228                         break;
1229
1230                 case FORMAT_TYPE_PERCENT_CHAR:
1231                         if (str < end)
1232                                 *str = '%';
1233                         ++str;
1234                         break;
1235
1236                 case FORMAT_TYPE_INVALID:
1237                         if (str < end)
1238                                 *str = '%';
1239                         ++str;
1240                         break;
1241
1242                 case FORMAT_TYPE_NRCHARS: {
1243                         int qualifier = spec.qualifier;
1244
1245                         if (qualifier == 'l') {
1246                                 long *ip = va_arg(args, long *);
1247                                 *ip = (str - buf);
1248                         } else if (qualifier == 'Z' ||
1249                                         qualifier == 'z') {
1250                                 size_t *ip = va_arg(args, size_t *);
1251                                 *ip = (str - buf);
1252                         } else {
1253                                 int *ip = va_arg(args, int *);
1254                                 *ip = (str - buf);
1255                         }
1256                         break;
1257                 }
1258
1259                 default:
1260                         switch (spec.type) {
1261                         case FORMAT_TYPE_LONG_LONG:
1262                                 num = va_arg(args, long long);
1263                                 break;
1264                         case FORMAT_TYPE_ULONG:
1265                                 num = va_arg(args, unsigned long);
1266                                 break;
1267                         case FORMAT_TYPE_LONG:
1268                                 num = va_arg(args, long);
1269                                 break;
1270                         case FORMAT_TYPE_SIZE_T:
1271                                 num = va_arg(args, size_t);
1272                                 break;
1273                         case FORMAT_TYPE_PTRDIFF:
1274                                 num = va_arg(args, ptrdiff_t);
1275                                 break;
1276                         case FORMAT_TYPE_UBYTE:
1277                                 num = (unsigned char) va_arg(args, int);
1278                                 break;
1279                         case FORMAT_TYPE_BYTE:
1280                                 num = (signed char) va_arg(args, int);
1281                                 break;
1282                         case FORMAT_TYPE_USHORT:
1283                                 num = (unsigned short) va_arg(args, int);
1284                                 break;
1285                         case FORMAT_TYPE_SHORT:
1286                                 num = (short) va_arg(args, int);
1287                                 break;
1288                         case FORMAT_TYPE_INT:
1289                                 num = (int) va_arg(args, int);
1290                                 break;
1291                         default:
1292                                 num = va_arg(args, unsigned int);
1293                         }
1294
1295                         str = number(str, end, num, spec);
1296                 }
1297         }
1298
1299         if (size > 0) {
1300                 if (str < end)
1301                         *str = '\0';
1302                 else
1303                         end[-1] = '\0';
1304         }
1305
1306         /* the trailing null byte doesn't count towards the total */
1307         return str-buf;
1308
1309 }
1310 EXPORT_SYMBOL(vsnprintf);
1311
1312 /**
1313  * vscnprintf - Format a string and place it in a buffer
1314  * @buf: The buffer to place the result into
1315  * @size: The size of the buffer, including the trailing null space
1316  * @fmt: The format string to use
1317  * @args: Arguments for the format string
1318  *
1319  * The return value is the number of characters which have been written into
1320  * the @buf not including the trailing '\0'. If @size is <= 0 the function
1321  * returns 0.
1322  *
1323  * Call this function if you are already dealing with a va_list.
1324  * You probably want scnprintf() instead.
1325  *
1326  * See the vsnprintf() documentation for format string extensions over C99.
1327  */
1328 int vscnprintf(char *buf, size_t size, const char *fmt, va_list args)
1329 {
1330         int i;
1331
1332         i=vsnprintf(buf,size,fmt,args);
1333         return (i >= size) ? (size - 1) : i;
1334 }
1335 EXPORT_SYMBOL(vscnprintf);
1336
1337 /**
1338  * snprintf - Format a string and place it in a buffer
1339  * @buf: The buffer to place the result into
1340  * @size: The size of the buffer, including the trailing null space
1341  * @fmt: The format string to use
1342  * @...: Arguments for the format string
1343  *
1344  * The return value is the number of characters which would be
1345  * generated for the given input, excluding the trailing null,
1346  * as per ISO C99.  If the return is greater than or equal to
1347  * @size, the resulting string is truncated.
1348  *
1349  * See the vsnprintf() documentation for format string extensions over C99.
1350  */
1351 int snprintf(char * buf, size_t size, const char *fmt, ...)
1352 {
1353         va_list args;
1354         int i;
1355
1356         va_start(args, fmt);
1357         i=vsnprintf(buf,size,fmt,args);
1358         va_end(args);
1359         return i;
1360 }
1361 EXPORT_SYMBOL(snprintf);
1362
1363 /**
1364  * scnprintf - Format a string and place it in a buffer
1365  * @buf: The buffer to place the result into
1366  * @size: The size of the buffer, including the trailing null space
1367  * @fmt: The format string to use
1368  * @...: Arguments for the format string
1369  *
1370  * The return value is the number of characters written into @buf not including
1371  * the trailing '\0'. If @size is <= 0 the function returns 0.
1372  */
1373
1374 int scnprintf(char * buf, size_t size, const char *fmt, ...)
1375 {
1376         va_list args;
1377         int i;
1378
1379         va_start(args, fmt);
1380         i = vsnprintf(buf, size, fmt, args);
1381         va_end(args);
1382         return (i >= size) ? (size - 1) : i;
1383 }
1384 EXPORT_SYMBOL(scnprintf);
1385
1386 /**
1387  * vsprintf - Format a string and place it in a buffer
1388  * @buf: The buffer to place the result into
1389  * @fmt: The format string to use
1390  * @args: Arguments for the format string
1391  *
1392  * The function returns the number of characters written
1393  * into @buf. Use vsnprintf() or vscnprintf() in order to avoid
1394  * buffer overflows.
1395  *
1396  * Call this function if you are already dealing with a va_list.
1397  * You probably want sprintf() instead.
1398  *
1399  * See the vsnprintf() documentation for format string extensions over C99.
1400  */
1401 int vsprintf(char *buf, const char *fmt, va_list args)
1402 {
1403         return vsnprintf(buf, INT_MAX, fmt, args);
1404 }
1405 EXPORT_SYMBOL(vsprintf);
1406
1407 /**
1408  * sprintf - Format a string and place it in a buffer
1409  * @buf: The buffer to place the result into
1410  * @fmt: The format string to use
1411  * @...: Arguments for the format string
1412  *
1413  * The function returns the number of characters written
1414  * into @buf. Use snprintf() or scnprintf() in order to avoid
1415  * buffer overflows.
1416  *
1417  * See the vsnprintf() documentation for format string extensions over C99.
1418  */
1419 int sprintf(char * buf, const char *fmt, ...)
1420 {
1421         va_list args;
1422         int i;
1423
1424         va_start(args, fmt);
1425         i=vsnprintf(buf, INT_MAX, fmt, args);
1426         va_end(args);
1427         return i;
1428 }
1429 EXPORT_SYMBOL(sprintf);
1430
1431 #ifdef CONFIG_BINARY_PRINTF
1432 /*
1433  * bprintf service:
1434  * vbin_printf() - VA arguments to binary data
1435  * bstr_printf() - Binary data to text string
1436  */
1437
1438 /**
1439  * vbin_printf - Parse a format string and place args' binary value in a buffer
1440  * @bin_buf: The buffer to place args' binary value
1441  * @size: The size of the buffer(by words(32bits), not characters)
1442  * @fmt: The format string to use
1443  * @args: Arguments for the format string
1444  *
1445  * The format follows C99 vsnprintf, except %n is ignored, and its argument
1446  * is skiped.
1447  *
1448  * The return value is the number of words(32bits) which would be generated for
1449  * the given input.
1450  *
1451  * NOTE:
1452  * If the return value is greater than @size, the resulting bin_buf is NOT
1453  * valid for bstr_printf().
1454  */
1455 int vbin_printf(u32 *bin_buf, size_t size, const char *fmt, va_list args)
1456 {
1457         struct printf_spec spec = {0};
1458         char *str, *end;
1459         int read;
1460
1461         str = (char *)bin_buf;
1462         end = (char *)(bin_buf + size);
1463
1464 #define save_arg(type)                                                  \
1465 do {                                                                    \
1466         if (sizeof(type) == 8) {                                        \
1467                 unsigned long long value;                               \
1468                 str = PTR_ALIGN(str, sizeof(u32));                      \
1469                 value = va_arg(args, unsigned long long);               \
1470                 if (str + sizeof(type) <= end) {                        \
1471                         *(u32 *)str = *(u32 *)&value;                   \
1472                         *(u32 *)(str + 4) = *((u32 *)&value + 1);       \
1473                 }                                                       \
1474         } else {                                                        \
1475                 unsigned long value;                                    \
1476                 str = PTR_ALIGN(str, sizeof(type));                     \
1477                 value = va_arg(args, int);                              \
1478                 if (str + sizeof(type) <= end)                          \
1479                         *(typeof(type) *)str = (type)value;             \
1480         }                                                               \
1481         str += sizeof(type);                                            \
1482 } while (0)
1483
1484
1485         while (*fmt) {
1486                 read = format_decode(fmt, &spec);
1487
1488                 fmt += read;
1489
1490                 switch (spec.type) {
1491                 case FORMAT_TYPE_NONE:
1492                         break;
1493
1494                 case FORMAT_TYPE_WIDTH:
1495                 case FORMAT_TYPE_PRECISION:
1496                         save_arg(int);
1497                         break;
1498
1499                 case FORMAT_TYPE_CHAR:
1500                         save_arg(char);
1501                         break;
1502
1503                 case FORMAT_TYPE_STR: {
1504                         const char *save_str = va_arg(args, char *);
1505                         size_t len;
1506                         if ((unsigned long)save_str > (unsigned long)-PAGE_SIZE
1507                                         || (unsigned long)save_str < PAGE_SIZE)
1508                                 save_str = "<NULL>";
1509                         len = strlen(save_str);
1510                         if (str + len + 1 < end)
1511                                 memcpy(str, save_str, len + 1);
1512                         str += len + 1;
1513                         break;
1514                 }
1515
1516                 case FORMAT_TYPE_PTR:
1517                         save_arg(void *);
1518                         /* skip all alphanumeric pointer suffixes */
1519                         while (isalnum(*fmt))
1520                                 fmt++;
1521                         break;
1522
1523                 case FORMAT_TYPE_PERCENT_CHAR:
1524                         break;
1525
1526                 case FORMAT_TYPE_INVALID:
1527                         break;
1528
1529                 case FORMAT_TYPE_NRCHARS: {
1530                         /* skip %n 's argument */
1531                         int qualifier = spec.qualifier;
1532                         void *skip_arg;
1533                         if (qualifier == 'l')
1534                                 skip_arg = va_arg(args, long *);
1535                         else if (qualifier == 'Z' || qualifier == 'z')
1536                                 skip_arg = va_arg(args, size_t *);
1537                         else
1538                                 skip_arg = va_arg(args, int *);
1539                         break;
1540                 }
1541
1542                 default:
1543                         switch (spec.type) {
1544
1545                         case FORMAT_TYPE_LONG_LONG:
1546                                 save_arg(long long);
1547                                 break;
1548                         case FORMAT_TYPE_ULONG:
1549                         case FORMAT_TYPE_LONG:
1550                                 save_arg(unsigned long);
1551                                 break;
1552                         case FORMAT_TYPE_SIZE_T:
1553                                 save_arg(size_t);
1554                                 break;
1555                         case FORMAT_TYPE_PTRDIFF:
1556                                 save_arg(ptrdiff_t);
1557                                 break;
1558                         case FORMAT_TYPE_UBYTE:
1559                         case FORMAT_TYPE_BYTE:
1560                                 save_arg(char);
1561                                 break;
1562                         case FORMAT_TYPE_USHORT:
1563                         case FORMAT_TYPE_SHORT:
1564                                 save_arg(short);
1565                                 break;
1566                         default:
1567                                 save_arg(int);
1568                         }
1569                 }
1570         }
1571         return (u32 *)(PTR_ALIGN(str, sizeof(u32))) - bin_buf;
1572
1573 #undef save_arg
1574 }
1575 EXPORT_SYMBOL_GPL(vbin_printf);
1576
1577 /**
1578  * bstr_printf - Format a string from binary arguments and place it in a buffer
1579  * @buf: The buffer to place the result into
1580  * @size: The size of the buffer, including the trailing null space
1581  * @fmt: The format string to use
1582  * @bin_buf: Binary arguments for the format string
1583  *
1584  * This function like C99 vsnprintf, but the difference is that vsnprintf gets
1585  * arguments from stack, and bstr_printf gets arguments from @bin_buf which is
1586  * a binary buffer that generated by vbin_printf.
1587  *
1588  * The format follows C99 vsnprintf, but has some extensions:
1589  *  see vsnprintf comment for details.
1590  *
1591  * The return value is the number of characters which would
1592  * be generated for the given input, excluding the trailing
1593  * '\0', as per ISO C99. If you want to have the exact
1594  * number of characters written into @buf as return value
1595  * (not including the trailing '\0'), use vscnprintf(). If the
1596  * return is greater than or equal to @size, the resulting
1597  * string is truncated.
1598  */
1599 int bstr_printf(char *buf, size_t size, const char *fmt, const u32 *bin_buf)
1600 {
1601         unsigned long long num;
1602         char *str, *end, c;
1603         const char *args = (const char *)bin_buf;
1604
1605         struct printf_spec spec = {0};
1606
1607         if (WARN_ON_ONCE((int) size < 0))
1608                 return 0;
1609
1610         str = buf;
1611         end = buf + size;
1612
1613 #define get_arg(type)                                                   \
1614 ({                                                                      \
1615         typeof(type) value;                                             \
1616         if (sizeof(type) == 8) {                                        \
1617                 args = PTR_ALIGN(args, sizeof(u32));                    \
1618                 *(u32 *)&value = *(u32 *)args;                          \
1619                 *((u32 *)&value + 1) = *(u32 *)(args + 4);              \
1620         } else {                                                        \
1621                 args = PTR_ALIGN(args, sizeof(type));                   \
1622                 value = *(typeof(type) *)args;                          \
1623         }                                                               \
1624         args += sizeof(type);                                           \
1625         value;                                                          \
1626 })
1627
1628         /* Make sure end is always >= buf */
1629         if (end < buf) {
1630                 end = ((void *)-1);
1631                 size = end - buf;
1632         }
1633
1634         while (*fmt) {
1635                 int read;
1636                 const char *old_fmt = fmt;
1637
1638                 read = format_decode(fmt, &spec);
1639
1640                 fmt += read;
1641
1642                 switch (spec.type) {
1643                 case FORMAT_TYPE_NONE: {
1644                         int copy = read;
1645                         if (str < end) {
1646                                 if (copy > end - str)
1647                                         copy = end - str;
1648                                 memcpy(str, old_fmt, copy);
1649                         }
1650                         str += read;
1651                         break;
1652                 }
1653
1654                 case FORMAT_TYPE_WIDTH:
1655                         spec.field_width = get_arg(int);
1656                         break;
1657
1658                 case FORMAT_TYPE_PRECISION:
1659                         spec.precision = get_arg(int);
1660                         break;
1661
1662                 case FORMAT_TYPE_CHAR:
1663                         if (!(spec.flags & LEFT)) {
1664                                 while (--spec.field_width > 0) {
1665                                         if (str < end)
1666                                                 *str = ' ';
1667                                         ++str;
1668                                 }
1669                         }
1670                         c = (unsigned char) get_arg(char);
1671                         if (str < end)
1672                                 *str = c;
1673                         ++str;
1674                         while (--spec.field_width > 0) {
1675                                 if (str < end)
1676                                         *str = ' ';
1677                                 ++str;
1678                         }
1679                         break;
1680
1681                 case FORMAT_TYPE_STR: {
1682                         const char *str_arg = args;
1683                         size_t len = strlen(str_arg);
1684                         args += len + 1;
1685                         str = string(str, end, (char *)str_arg, spec);
1686                         break;
1687                 }
1688
1689                 case FORMAT_TYPE_PTR:
1690                         str = pointer(fmt+1, str, end, get_arg(void *), spec);
1691                         while (isalnum(*fmt))
1692                                 fmt++;
1693                         break;
1694
1695                 case FORMAT_TYPE_PERCENT_CHAR:
1696                         if (str < end)
1697                                 *str = '%';
1698                         ++str;
1699                         break;
1700
1701                 case FORMAT_TYPE_INVALID:
1702                         if (str < end)
1703                                 *str = '%';
1704                         ++str;
1705                         break;
1706
1707                 case FORMAT_TYPE_NRCHARS:
1708                         /* skip */
1709                         break;
1710
1711                 default:
1712                         switch (spec.type) {
1713
1714                         case FORMAT_TYPE_LONG_LONG:
1715                                 num = get_arg(long long);
1716                                 break;
1717                         case FORMAT_TYPE_ULONG:
1718                                 num = get_arg(unsigned long);
1719                                 break;
1720                         case FORMAT_TYPE_LONG:
1721                                 num = get_arg(unsigned long);
1722                                 break;
1723                         case FORMAT_TYPE_SIZE_T:
1724                                 num = get_arg(size_t);
1725                                 break;
1726                         case FORMAT_TYPE_PTRDIFF:
1727                                 num = get_arg(ptrdiff_t);
1728                                 break;
1729                         case FORMAT_TYPE_UBYTE:
1730                                 num = get_arg(unsigned char);
1731                                 break;
1732                         case FORMAT_TYPE_BYTE:
1733                                 num = get_arg(signed char);
1734                                 break;
1735                         case FORMAT_TYPE_USHORT:
1736                                 num = get_arg(unsigned short);
1737                                 break;
1738                         case FORMAT_TYPE_SHORT:
1739                                 num = get_arg(short);
1740                                 break;
1741                         case FORMAT_TYPE_UINT:
1742                                 num = get_arg(unsigned int);
1743                                 break;
1744                         default:
1745                                 num = get_arg(int);
1746                         }
1747
1748                         str = number(str, end, num, spec);
1749                 }
1750         }
1751
1752         if (size > 0) {
1753                 if (str < end)
1754                         *str = '\0';
1755                 else
1756                         end[-1] = '\0';
1757         }
1758
1759 #undef get_arg
1760
1761         /* the trailing null byte doesn't count towards the total */
1762         return str - buf;
1763 }
1764 EXPORT_SYMBOL_GPL(bstr_printf);
1765
1766 /**
1767  * bprintf - Parse a format string and place args' binary value in a buffer
1768  * @bin_buf: The buffer to place args' binary value
1769  * @size: The size of the buffer(by words(32bits), not characters)
1770  * @fmt: The format string to use
1771  * @...: Arguments for the format string
1772  *
1773  * The function returns the number of words(u32) written
1774  * into @bin_buf.
1775  */
1776 int bprintf(u32 *bin_buf, size_t size, const char *fmt, ...)
1777 {
1778         va_list args;
1779         int ret;
1780
1781         va_start(args, fmt);
1782         ret = vbin_printf(bin_buf, size, fmt, args);
1783         va_end(args);
1784         return ret;
1785 }
1786 EXPORT_SYMBOL_GPL(bprintf);
1787
1788 #endif /* CONFIG_BINARY_PRINTF */
1789
1790 /**
1791  * vsscanf - Unformat a buffer into a list of arguments
1792  * @buf:        input buffer
1793  * @fmt:        format of buffer
1794  * @args:       arguments
1795  */
1796 int vsscanf(const char * buf, const char * fmt, va_list args)
1797 {
1798         const char *str = buf;
1799         char *next;
1800         char digit;
1801         int num = 0;
1802         int qualifier;
1803         int base;
1804         int field_width;
1805         int is_sign = 0;
1806
1807         while(*fmt && *str) {
1808                 /* skip any white space in format */
1809                 /* white space in format matchs any amount of
1810                  * white space, including none, in the input.
1811                  */
1812                 if (isspace(*fmt)) {
1813                         while (isspace(*fmt))
1814                                 ++fmt;
1815                         while (isspace(*str))
1816                                 ++str;
1817                 }
1818
1819                 /* anything that is not a conversion must match exactly */
1820                 if (*fmt != '%' && *fmt) {
1821                         if (*fmt++ != *str++)
1822                                 break;
1823                         continue;
1824                 }
1825
1826                 if (!*fmt)
1827                         break;
1828                 ++fmt;
1829
1830                 /* skip this conversion.
1831                  * advance both strings to next white space
1832                  */
1833                 if (*fmt == '*') {
1834                         while (!isspace(*fmt) && *fmt != '%' && *fmt)
1835                                 fmt++;
1836                         while (!isspace(*str) && *str)
1837                                 str++;
1838                         continue;
1839                 }
1840
1841                 /* get field width */
1842                 field_width = -1;
1843                 if (isdigit(*fmt))
1844                         field_width = skip_atoi(&fmt);
1845
1846                 /* get conversion qualifier */
1847                 qualifier = -1;
1848                 if (*fmt == 'h' || *fmt == 'l' || *fmt == 'L' ||
1849                     *fmt == 'Z' || *fmt == 'z') {
1850                         qualifier = *fmt++;
1851                         if (unlikely(qualifier == *fmt)) {
1852                                 if (qualifier == 'h') {
1853                                         qualifier = 'H';
1854                                         fmt++;
1855                                 } else if (qualifier == 'l') {
1856                                         qualifier = 'L';
1857                                         fmt++;
1858                                 }
1859                         }
1860                 }
1861                 base = 10;
1862                 is_sign = 0;
1863
1864                 if (!*fmt || !*str)
1865                         break;
1866
1867                 switch(*fmt++) {
1868                 case 'c':
1869                 {
1870                         char *s = (char *) va_arg(args,char*);
1871                         if (field_width == -1)
1872                                 field_width = 1;
1873                         do {
1874                                 *s++ = *str++;
1875                         } while (--field_width > 0 && *str);
1876                         num++;
1877                 }
1878                 continue;
1879                 case 's':
1880                 {
1881                         char *s = (char *) va_arg(args, char *);
1882                         if(field_width == -1)
1883                                 field_width = INT_MAX;
1884                         /* first, skip leading white space in buffer */
1885                         while (isspace(*str))
1886                                 str++;
1887
1888                         /* now copy until next white space */
1889                         while (*str && !isspace(*str) && field_width--) {
1890                                 *s++ = *str++;
1891                         }
1892                         *s = '\0';
1893                         num++;
1894                 }
1895                 continue;
1896                 case 'n':
1897                         /* return number of characters read so far */
1898                 {
1899                         int *i = (int *)va_arg(args,int*);
1900                         *i = str - buf;
1901                 }
1902                 continue;
1903                 case 'o':
1904                         base = 8;
1905                         break;
1906                 case 'x':
1907                 case 'X':
1908                         base = 16;
1909                         break;
1910                 case 'i':
1911                         base = 0;
1912                 case 'd':
1913                         is_sign = 1;
1914                 case 'u':
1915                         break;
1916                 case '%':
1917                         /* looking for '%' in str */
1918                         if (*str++ != '%')
1919                                 return num;
1920                         continue;
1921                 default:
1922                         /* invalid format; stop here */
1923                         return num;
1924                 }
1925
1926                 /* have some sort of integer conversion.
1927                  * first, skip white space in buffer.
1928                  */
1929                 while (isspace(*str))
1930                         str++;
1931
1932                 digit = *str;
1933                 if (is_sign && digit == '-')
1934                         digit = *(str + 1);
1935
1936                 if (!digit
1937                     || (base == 16 && !isxdigit(digit))
1938                     || (base == 10 && !isdigit(digit))
1939                     || (base == 8 && (!isdigit(digit) || digit > '7'))
1940                     || (base == 0 && !isdigit(digit)))
1941                                 break;
1942
1943                 switch(qualifier) {
1944                 case 'H':       /* that's 'hh' in format */
1945                         if (is_sign) {
1946                                 signed char *s = (signed char *) va_arg(args,signed char *);
1947                                 *s = (signed char) simple_strtol(str,&next,base);
1948                         } else {
1949                                 unsigned char *s = (unsigned char *) va_arg(args, unsigned char *);
1950                                 *s = (unsigned char) simple_strtoul(str, &next, base);
1951                         }
1952                         break;
1953                 case 'h':
1954                         if (is_sign) {
1955                                 short *s = (short *) va_arg(args,short *);
1956                                 *s = (short) simple_strtol(str,&next,base);
1957                         } else {
1958                                 unsigned short *s = (unsigned short *) va_arg(args, unsigned short *);
1959                                 *s = (unsigned short) simple_strtoul(str, &next, base);
1960                         }
1961                         break;
1962                 case 'l':
1963                         if (is_sign) {
1964                                 long *l = (long *) va_arg(args,long *);
1965                                 *l = simple_strtol(str,&next,base);
1966                         } else {
1967                                 unsigned long *l = (unsigned long*) va_arg(args,unsigned long*);
1968                                 *l = simple_strtoul(str,&next,base);
1969                         }
1970                         break;
1971                 case 'L':
1972                         if (is_sign) {
1973                                 long long *l = (long long*) va_arg(args,long long *);
1974                                 *l = simple_strtoll(str,&next,base);
1975                         } else {
1976                                 unsigned long long *l = (unsigned long long*) va_arg(args,unsigned long long*);
1977                                 *l = simple_strtoull(str,&next,base);
1978                         }
1979                         break;
1980                 case 'Z':
1981                 case 'z':
1982                 {
1983                         size_t *s = (size_t*) va_arg(args,size_t*);
1984                         *s = (size_t) simple_strtoul(str,&next,base);
1985                 }
1986                 break;
1987                 default:
1988                         if (is_sign) {
1989                                 int *i = (int *) va_arg(args, int*);
1990                                 *i = (int) simple_strtol(str,&next,base);
1991                         } else {
1992                                 unsigned int *i = (unsigned int*) va_arg(args, unsigned int*);
1993                                 *i = (unsigned int) simple_strtoul(str,&next,base);
1994                         }
1995                         break;
1996                 }
1997                 num++;
1998
1999                 if (!next)
2000                         break;
2001                 str = next;
2002         }
2003
2004         /*
2005          * Now we've come all the way through so either the input string or the
2006          * format ended. In the former case, there can be a %n at the current
2007          * position in the format that needs to be filled.
2008          */
2009         if (*fmt == '%' && *(fmt + 1) == 'n') {
2010                 int *p = (int *)va_arg(args, int *);
2011                 *p = str - buf;
2012         }
2013
2014         return num;
2015 }
2016 EXPORT_SYMBOL(vsscanf);
2017
2018 /**
2019  * sscanf - Unformat a buffer into a list of arguments
2020  * @buf:        input buffer
2021  * @fmt:        formatting of buffer
2022  * @...:        resulting arguments
2023  */
2024 int sscanf(const char * buf, const char * fmt, ...)
2025 {
2026         va_list args;
2027         int i;
2028
2029         va_start(args,fmt);
2030         i = vsscanf(buf,fmt,args);
2031         va_end(args);
2032         return i;
2033 }
2034 EXPORT_SYMBOL(sscanf);