lib/vsprintf.c

   1 /*
   2  *  linux/lib/vsprintf.c
   3  *
   4  *  Copyright (C) 1991, 1992  Linus Torvalds
   5  */
   6
   7 /* vsprintf.c -- Lars Wirzenius & Linus Torvalds. */
   8 /*
   9  * Wirzenius wrote this portably, Torvalds fucked it up :-)
  10  */
  11
  12 /*
  13  * Fri Jul 13 2001 Crutcher Dunnavant <crutcher+kernel@datastacks.com>
  14  * - changed to provide snprintf and vsnprintf functions
  15  * So Feb  1 16:51:32 CET 2004 Juergen Quade <quade@hsnr.de>
  16  * - scnprintf and vscnprintf
  17  */
  18
  19 #include <stdarg.h>
  20 #include <linux/module.h>
  21 #include <linux/types.h>
  22 #include <linux/string.h>
  23 #include <linux/ctype.h>
  24 #include <linux/kernel.h>
  25 #include <linux/kallsyms.h>
  26 #include <linux/uaccess.h>
  27 #include <linux/ioport.h>
  28 #include <net/addrconf.h>
  29
  30 #include <asm/page.h>           /* for PAGE_SIZE */
  31 #include <asm/div64.h>
  32 #include <asm/sections.h>       /* for dereference_function_descriptor() */
  33
  34 /* Works only for digits and letters, but small and fast */
  35 #define TOLOWER(x) ((x) | 0x20)
  36
  37 static unsigned int simple_guess_base(const char *cp)
  38 {
  39         if (cp[0] == '0') {
  40                 if (TOLOWER(cp[1]) == 'x' && isxdigit(cp[2]))
  41                         return 16;
  42                 else
  43                         return 8;
  44         } else {
  45                 return 10;
  46         }
  47 }
  48
  49 /**
  50  * simple_strtoull - convert a string to an unsigned long long
  51  * @cp: The start of the string
  52  * @endp: A pointer to the end of the parsed string will be placed here
  53  * @base: The number base to use
  54  */
  55 unsigned long long simple_strtoull(const char *cp, char **endp, unsigned int base)
  56 {
  57         unsigned long long result = 0;
  58
  59         if (!base)
  60                 base = simple_guess_base(cp);
  61
  62         if (base == 16 && cp[0] == '0' && TOLOWER(cp[1]) == 'x')
  63                 cp += 2;
  64
  65         while (isxdigit(*cp)) {
  66                 unsigned int value;
  67
  68                 value = isdigit(*cp) ? *cp - '0' : TOLOWER(*cp) - 'a' + 10;
  69                 if (value >= base)
  70                         break;
  71                 result = result * base + value;
  72                 cp++;
  73         }
  74         if (endp)
  75                 *endp = (char *)cp;
  76
  77         return result;
  78 }
  79 EXPORT_SYMBOL(simple_strtoull);
  80
  81 /**
  82  * simple_strtoul - convert a string to an unsigned long
  83  * @cp: The start of the string
  84  * @endp: A pointer to the end of the parsed string will be placed here
  85  * @base: The number base to use
  86  */
  87 unsigned long simple_strtoul(const char *cp, char **endp, unsigned int base)
  88 {
  89         return simple_strtoull(cp, endp, base);
  90 }
  91 EXPORT_SYMBOL(simple_strtoul);
  92
  93 /**
  94  * simple_strtol - convert a string to a signed long
  95  * @cp: The start of the string
  96  * @endp: A pointer to the end of the parsed string will be placed here
  97  * @base: The number base to use
  98  */
  99 long simple_strtol(const char *cp, char **endp, unsigned int base)
 100 {
 101         if (*cp == '-')
 102                 return -simple_strtoul(cp + 1, endp, base);
 103
 104         return simple_strtoul(cp, endp, base);
 105 }
 106 EXPORT_SYMBOL(simple_strtol);
 107
 108 /**
 109  * simple_strtoll - convert a string to a signed long long
 110  * @cp: The start of the string
 111  * @endp: A pointer to the end of the parsed string will be placed here
 112  * @base: The number base to use
 113  */
 114 long long simple_strtoll(const char *cp, char **endp, unsigned int base)
 115 {
 116         if (*cp == '-')
 117                 return -simple_strtoull(cp + 1, endp, base);
 118
 119         return simple_strtoull(cp, endp, base);
 120 }
 121
 122 /**
 123  * strict_strtoul - convert a string to an unsigned long strictly
 124  * @cp: The string to be converted
 125  * @base: The number base to use
 126  * @res: The converted result value
 127  *
 128  * strict_strtoul converts a string to an unsigned long only if the
 129  * string is really an unsigned long string, any string containing
 130  * any invalid char at the tail will be rejected and -EINVAL is returned,
 131  * only a newline char at the tail is acceptible because people generally
 132  * change a module parameter in the following way:
 133  *
 134  *      echo 1024 > /sys/module/e1000/parameters/copybreak
 135  *
 136  * echo will append a newline to the tail.
 137  *
 138  * It returns 0 if conversion is successful and *res is set to the converted
 139  * value, otherwise it returns -EINVAL and *res is set to 0.
 140  *
 141  * simple_strtoul just ignores the successive invalid characters and
 142  * return the converted value of prefix part of the string.
 143  */
 144 int strict_strtoul(const char *cp, unsigned int base, unsigned long *res)
 145 {
 146         char *tail;
 147         unsigned long val;
 148         size_t len;
 149
 150         *res = 0;
 151         len = strlen(cp);
 152         if (len == 0)
 153                 return -EINVAL;
 154
 155         val = simple_strtoul(cp, &tail, base);
 156         if (tail == cp)
 157                 return -EINVAL;
 158
 159         if ((*tail == '\0') ||
 160                 ((len == (size_t)(tail - cp) + 1) && (*tail == '\n'))) {
 161                 *res = val;
 162                 return 0;
 163         }
 164
 165         return -EINVAL;
 166 }
 167 EXPORT_SYMBOL(strict_strtoul);
 168
 169 /**
 170  * strict_strtol - convert a string to a long strictly
 171  * @cp: The string to be converted
 172  * @base: The number base to use
 173  * @res: The converted result value
 174  *
 175  * strict_strtol is similiar to strict_strtoul, but it allows the first
 176  * character of a string is '-'.
 177  *
 178  * It returns 0 if conversion is successful and *res is set to the converted
 179  * value, otherwise it returns -EINVAL and *res is set to 0.
 180  */
 181 int strict_strtol(const char *cp, unsigned int base, long *res)
 182 {
 183         int ret;
 184         if (*cp == '-') {
 185                 ret = strict_strtoul(cp + 1, base, (unsigned long *)res);
 186                 if (!ret)
 187                         *res = -(*res);
 188         } else {
 189                 ret = strict_strtoul(cp, base, (unsigned long *)res);
 190         }
 191
 192         return ret;
 193 }
 194 EXPORT_SYMBOL(strict_strtol);
 195
 196 /**
 197  * strict_strtoull - convert a string to an unsigned long long strictly
 198  * @cp: The string to be converted
 199  * @base: The number base to use
 200  * @res: The converted result value
 201  *
 202  * strict_strtoull converts a string to an unsigned long long only if the
 203  * string is really an unsigned long long string, any string containing
 204  * any invalid char at the tail will be rejected and -EINVAL is returned,
 205  * only a newline char at the tail is acceptible because people generally
 206  * change a module parameter in the following way:
 207  *
 208  *      echo 1024 > /sys/module/e1000/parameters/copybreak
 209  *
 210  * echo will append a newline to the tail of the string.
 211  *
 212  * It returns 0 if conversion is successful and *res is set to the converted
 213  * value, otherwise it returns -EINVAL and *res is set to 0.
 214  *
 215  * simple_strtoull just ignores the successive invalid characters and
 216  * return the converted value of prefix part of the string.
 217  */
 218 int strict_strtoull(const char *cp, unsigned int base, unsigned long long *res)
 219 {
 220         char *tail;
 221         unsigned long long val;
 222         size_t len;
 223
 224         *res = 0;
 225         len = strlen(cp);
 226         if (len == 0)
 227                 return -EINVAL;
 228
 229         val = simple_strtoull(cp, &tail, base);
 230         if (tail == cp)
 231                 return -EINVAL;
 232         if ((*tail == '\0') ||
 233                 ((len == (size_t)(tail - cp) + 1) && (*tail == '\n'))) {
 234                 *res = val;
 235                 return 0;
 236         }
 237
 238         return -EINVAL;
 239 }
 240 EXPORT_SYMBOL(strict_strtoull);
 241
 242 /**
 243  * strict_strtoll - convert a string to a long long strictly
 244  * @cp: The string to be converted
 245  * @base: The number base to use
 246  * @res: The converted result value
 247  *
 248  * strict_strtoll is similiar to strict_strtoull, but it allows the first
 249  * character of a string is '-'.
 250  *
 251  * It returns 0 if conversion is successful and *res is set to the converted
 252  * value, otherwise it returns -EINVAL and *res is set to 0.
 253  */
 254 int strict_strtoll(const char *cp, unsigned int base, long long *res)
 255 {
 256         int ret;
 257         if (*cp == '-') {
 258                 ret = strict_strtoull(cp + 1, base, (unsigned long long *)res);
 259                 if (!ret)
 260                         *res = -(*res);
 261         } else {
 262                 ret = strict_strtoull(cp, base, (unsigned long long *)res);
 263         }
 264
 265         return ret;
 266 }
 267 EXPORT_SYMBOL(strict_strtoll);
 268
 269 static int skip_atoi(const char **s)
 270 {
 271         int i = 0;
 272
 273         while (isdigit(**s))
 274                 i = i*10 + *((*s)++) - '0';
 275
 276         return i;
 277 }
 278
 279 /* Decimal conversion is by far the most typical, and is used
 280  * for /proc and /sys data. This directly impacts e.g. top performance
 281  * with many processes running. We optimize it for speed
 282  * using code from
 283  * http://www.cs.uiowa.edu/~jones/bcd/decimal.html
 284  * (with permission from the author, Douglas W. Jones). */
 285
 286 /* Formats correctly any integer in [0,99999].
 287  * Outputs from one to five digits depending on input.
 288  * On i386 gcc 4.1.2 -O2: ~250 bytes of code. */
 289 static char *put_dec_trunc(char *buf, unsigned q)
 290 {
 291         unsigned d3, d2, d1, d0;
 292         d1 = (q>>4) & 0xf;
 293         d2 = (q>>8) & 0xf;
 294         d3 = (q>>12);
 295
 296         d0 = 6*(d3 + d2 + d1) + (q & 0xf);
 297         q = (d0 * 0xcd) >> 11;
 298         d0 = d0 - 10*q;
 299         *buf++ = d0 + '0'; /* least significant digit */
 300         d1 = q + 9*d3 + 5*d2 + d1;
 301         if (d1 != 0) {
 302                 q = (d1 * 0xcd) >> 11;
 303                 d1 = d1 - 10*q;
 304                 *buf++ = d1 + '0'; /* next digit */
 305
 306                 d2 = q + 2*d2;
 307                 if ((d2 != 0) || (d3 != 0)) {
 308                         q = (d2 * 0xd) >> 7;
 309                         d2 = d2 - 10*q;
 310                         *buf++ = d2 + '0'; /* next digit */
 311
 312                         d3 = q + 4*d3;
 313                         if (d3 != 0) {
 314                                 q = (d3 * 0xcd) >> 11;
 315                                 d3 = d3 - 10*q;
 316                                 *buf++ = d3 + '0';  /* next digit */
 317                                 if (q != 0)
 318                                         *buf++ = q + '0'; /* most sign. digit */
 319                         }
 320                 }
 321         }
 322
 323         return buf;
 324 }
 325 /* Same with if's removed. Always emits five digits */
 326 static char *put_dec_full(char *buf, unsigned q)
 327 {
 328         /* BTW, if q is in [0,9999], 8-bit ints will be enough, */
 329         /* but anyway, gcc produces better code with full-sized ints */
 330         unsigned d3, d2, d1, d0;
 331         d1 = (q>>4) & 0xf;
 332         d2 = (q>>8) & 0xf;
 333         d3 = (q>>12);
 334
 335         /*
 336          * Possible ways to approx. divide by 10
 337          * gcc -O2 replaces multiply with shifts and adds
 338          * (x * 0xcd) >> 11: 11001101 - shorter code than * 0x67 (on i386)
 339          * (x * 0x67) >> 10:  1100111
 340          * (x * 0x34) >> 9:    110100 - same
 341          * (x * 0x1a) >> 8:     11010 - same
 342          * (x * 0x0d) >> 7:      1101 - same, shortest code (on i386)
 343          */
 344         d0 = 6*(d3 + d2 + d1) + (q & 0xf);
 345         q = (d0 * 0xcd) >> 11;
 346         d0 = d0 - 10*q;
 347         *buf++ = d0 + '0';
 348         d1 = q + 9*d3 + 5*d2 + d1;
 349                 q = (d1 * 0xcd) >> 11;
 350                 d1 = d1 - 10*q;
 351                 *buf++ = d1 + '0';
 352
 353                 d2 = q + 2*d2;
 354                         q = (d2 * 0xd) >> 7;
 355                         d2 = d2 - 10*q;
 356                         *buf++ = d2 + '0';
 357
 358                         d3 = q + 4*d3;
 359                                 q = (d3 * 0xcd) >> 11; /* - shorter code */
 360                                 /* q = (d3 * 0x67) >> 10; - would also work */
 361                                 d3 = d3 - 10*q;
 362                                 *buf++ = d3 + '0';
 363                                         *buf++ = q + '0';
 364
 365         return buf;
 366 }
 367 /* No inlining helps gcc to use registers better */
 368 static noinline char *put_dec(char *buf, unsigned long long num)
 369 {
 370         while (1) {
 371                 unsigned rem;
 372                 if (num < 100000)
 373                         return put_dec_trunc(buf, num);
 374                 rem = do_div(num, 100000);
 375                 buf = put_dec_full(buf, rem);
 376         }
 377 }
 378
 379 #define ZEROPAD 1               /* pad with zero */
 380 #define SIGN    2               /* unsigned/signed long */
 381 #define PLUS    4               /* show plus */
 382 #define SPACE   8               /* space if plus */
 383 #define LEFT    16              /* left justified */
 384 #define SMALL   32              /* Must be 32 == 0x20 */
 385 #define SPECIAL 64              /* 0x */
 386
 387 enum format_type {
 388         FORMAT_TYPE_NONE, /* Just a string part */
 389         FORMAT_TYPE_WIDTH,
 390         FORMAT_TYPE_PRECISION,
 391         FORMAT_TYPE_CHAR,
 392         FORMAT_TYPE_STR,
 393         FORMAT_TYPE_PTR,
 394         FORMAT_TYPE_PERCENT_CHAR,
 395         FORMAT_TYPE_INVALID,
 396         FORMAT_TYPE_LONG_LONG,
 397         FORMAT_TYPE_ULONG,
 398         FORMAT_TYPE_LONG,
 399         FORMAT_TYPE_UBYTE,
 400         FORMAT_TYPE_BYTE,
 401         FORMAT_TYPE_USHORT,
 402         FORMAT_TYPE_SHORT,
 403         FORMAT_TYPE_UINT,
 404         FORMAT_TYPE_INT,
 405         FORMAT_TYPE_NRCHARS,
 406         FORMAT_TYPE_SIZE_T,
 407         FORMAT_TYPE_PTRDIFF
 408 };
 409
 410 struct printf_spec {
 411         enum format_type        type;
 412         int                     flags;          /* flags to number() */
 413         int                     field_width;    /* width of output field */
 414         int                     base;
 415         int                     precision;      /* # of digits/chars */
 416         int                     qualifier;
 417 };
 418
 419 static char *number(char *buf, char *end, unsigned long long num,
 420                         struct printf_spec spec)
 421 {
 422         /* we are called with base 8, 10 or 16, only, thus don't need "G..."  */
 423         static const char digits[16] = "0123456789ABCDEF"; /* "GHIJKLMNOPQRSTUVWXYZ"; */
 424
 425         char tmp[66];
 426         char sign;
 427         char locase;
 428         int need_pfx = ((spec.flags & SPECIAL) && spec.base != 10);
 429         int i;
 430
 431         /* locase = 0 or 0x20. ORing digits or letters with 'locase'
 432          * produces same digits or (maybe lowercased) letters */
 433         locase = (spec.flags & SMALL);
 434         if (spec.flags & LEFT)
 435                 spec.flags &= ~ZEROPAD;
 436         sign = 0;
 437         if (spec.flags & SIGN) {
 438                 if ((signed long long)num < 0) {
 439                         sign = '-';
 440                         num = -(signed long long)num;
 441                         spec.field_width--;
 442                 } else if (spec.flags & PLUS) {
 443                         sign = '+';
 444                         spec.field_width--;
 445                 } else if (spec.flags & SPACE) {
 446                         sign = ' ';
 447                         spec.field_width--;
 448                 }
 449         }
 450         if (need_pfx) {
 451                 spec.field_width--;
 452                 if (spec.base == 16)
 453                         spec.field_width--;
 454         }
 455
 456         /* generate full string in tmp[], in reverse order */
 457         i = 0;
 458         if (num == 0)
 459                 tmp[i++] = '0';
 460         /* Generic code, for any base:
 461         else do {
 462                 tmp[i++] = (digits[do_div(num,base)] | locase);
 463         } while (num != 0);
 464         */
 465         else if (spec.base != 10) { /* 8 or 16 */
 466                 int mask = spec.base - 1;
 467                 int shift = 3;
 468
 469                 if (spec.base == 16)
 470                         shift = 4;
 471                 do {
 472                         tmp[i++] = (digits[((unsigned char)num) & mask] | locase);
 473                         num >>= shift;
 474                 } while (num);
 475         } else { /* base 10 */
 476                 i = put_dec(tmp, num) - tmp;
 477         }
 478
 479         /* printing 100 using %2d gives "100", not "00" */
 480         if (i > spec.precision)
 481                 spec.precision = i;
 482         /* leading space padding */
 483         spec.field_width -= spec.precision;
 484         if (!(spec.flags & (ZEROPAD+LEFT))) {
 485                 while (--spec.field_width >= 0) {
 486                         if (buf < end)
 487                                 *buf = ' ';
 488                         ++buf;
 489                 }
 490         }
 491         /* sign */
 492         if (sign) {
 493                 if (buf < end)
 494                         *buf = sign;
 495                 ++buf;
 496         }
 497         /* "0x" / "0" prefix */
 498         if (need_pfx) {
 499                 if (buf < end)
 500                         *buf = '0';
 501                 ++buf;
 502                 if (spec.base == 16) {
 503                         if (buf < end)
 504                                 *buf = ('X' | locase);
 505                         ++buf;
 506                 }
 507         }
 508         /* zero or space padding */
 509         if (!(spec.flags & LEFT)) {
 510                 char c = (spec.flags & ZEROPAD) ? '0' : ' ';
 511                 while (--spec.field_width >= 0) {
 512                         if (buf < end)
 513                                 *buf = c;
 514                         ++buf;
 515                 }
 516         }
 517         /* hmm even more zero padding? */
 518         while (i <= --spec.precision) {
 519                 if (buf < end)
 520                         *buf = '0';
 521                 ++buf;
 522         }
 523         /* actual digits of result */
 524         while (--i >= 0) {
 525                 if (buf < end)
 526                         *buf = tmp[i];
 527                 ++buf;
 528         }
 529         /* trailing space padding */
 530         while (--spec.field_width >= 0) {
 531                 if (buf < end)
 532                         *buf = ' ';
 533                 ++buf;
 534         }
 535
 536         return buf;
 537 }
 538
 539 static char *string(char *buf, char *end, const char *s, struct printf_spec spec)
 540 {
 541         int len, i;
 542
 543         if ((unsigned long)s < PAGE_SIZE)
 544                 s = "(null)";
 545
 546         len = strnlen(s, spec.precision);
 547
 548         if (!(spec.flags & LEFT)) {
 549                 while (len < spec.field_width--) {
 550                         if (buf < end)
 551                                 *buf = ' ';
 552                         ++buf;
 553                 }
 554         }
 555         for (i = 0; i < len; ++i) {
 556                 if (buf < end)
 557                         *buf = *s;
 558                 ++buf; ++s;
 559         }
 560         while (len < spec.field_width--) {
 561                 if (buf < end)
 562                         *buf = ' ';
 563                 ++buf;
 564         }
 565
 566         return buf;
 567 }
 568
 569 static char *symbol_string(char *buf, char *end, void *ptr,
 570                                 struct printf_spec spec, char ext)
 571 {
 572         unsigned long value = (unsigned long) ptr;
 573 #ifdef CONFIG_KALLSYMS
 574         char sym[KSYM_SYMBOL_LEN];
 575         if (ext != 'f' && ext != 's')
 576                 sprint_symbol(sym, value);
 577         else
 578                 kallsyms_lookup(value, NULL, NULL, NULL, sym);
 579
 580         return string(buf, end, sym, spec);
 581 #else
 582         spec.field_width = 2 * sizeof(void *);
 583         spec.flags |= SPECIAL | SMALL | ZEROPAD;
 584         spec.base = 16;
 585
 586         return number(buf, end, value, spec);
 587 #endif
 588 }
 589
 590 static char *resource_string(char *buf, char *end, struct resource *res,
 591                                 struct printf_spec spec, const char *fmt)
 592 {
 593 #ifndef IO_RSRC_PRINTK_SIZE
 594 #define IO_RSRC_PRINTK_SIZE     6
 595 #endif
 596
 597 #ifndef MEM_RSRC_PRINTK_SIZE
 598 #define MEM_RSRC_PRINTK_SIZE    10
 599 #endif
 600         struct printf_spec hex_spec = {
 601                 .base = 16,
 602                 .precision = -1,
 603                 .flags = SPECIAL | SMALL | ZEROPAD,
 604         };
 605         struct printf_spec dec_spec = {
 606                 .base = 10,
 607                 .precision = -1,
 608                 .flags = 0,
 609         };
 610         struct printf_spec str_spec = {
 611                 .field_width = -1,
 612                 .precision = 10,
 613                 .flags = LEFT,
 614         };
 615         struct printf_spec flag_spec = {
 616                 .base = 16,
 617                 .precision = -1,
 618                 .flags = SPECIAL | SMALL,
 619         };
 620
 621         /* 32-bit res (sizeof==4): 10 chars in dec, 10 in hex ("0x" + 8)
 622          * 64-bit res (sizeof==8): 20 chars in dec, 18 in hex ("0x" + 16) */
 623 #define RSRC_BUF_SIZE           ((2 * sizeof(resource_size_t)) + 4)
 624 #define FLAG_BUF_SIZE           (2 * sizeof(res->flags))
 625 #define DECODED_BUF_SIZE        sizeof("[mem - 64bit pref disabled]")
 626 #define RAW_BUF_SIZE            sizeof("[mem - flags 0x]")
 627         char sym[max(2*RSRC_BUF_SIZE + DECODED_BUF_SIZE,
 628                      2*RSRC_BUF_SIZE + FLAG_BUF_SIZE + RAW_BUF_SIZE)];
 629
 630         char *p = sym, *pend = sym + sizeof(sym);
 631         int size = -1, addr = 0;
 632         int decode = (fmt[0] == 'R') ? 1 : 0;
 633
 634         if (res->flags & IORESOURCE_IO) {
 635                 size = IO_RSRC_PRINTK_SIZE;
 636                 addr = 1;
 637         } else if (res->flags & IORESOURCE_MEM) {
 638                 size = MEM_RSRC_PRINTK_SIZE;
 639                 addr = 1;
 640         }
 641
 642         *p++ = '[';
 643         if (res->flags & IORESOURCE_IO)
 644                 p = string(p, pend, "io  ", str_spec);
 645         else if (res->flags & IORESOURCE_MEM)
 646                 p = string(p, pend, "mem ", str_spec);
 647         else if (res->flags & IORESOURCE_IRQ)
 648                 p = string(p, pend, "irq ", str_spec);
 649         else if (res->flags & IORESOURCE_DMA)
 650                 p = string(p, pend, "dma ", str_spec);
 651         else {
 652                 p = string(p, pend, "??? ", str_spec);
 653                 decode = 0;
 654         }
 655         hex_spec.field_width = size;
 656         p = number(p, pend, res->start, addr ? hex_spec : dec_spec);
 657         if (res->start != res->end) {
 658                 *p++ = '-';
 659                 p = number(p, pend, res->end, addr ? hex_spec : dec_spec);
 660         }
 661         if (decode) {
 662                 if (res->flags & IORESOURCE_MEM_64)
 663                         p = string(p, pend, " 64bit", str_spec);
 664                 if (res->flags & IORESOURCE_PREFETCH)
 665                         p = string(p, pend, " pref", str_spec);
 666                 if (res->flags & IORESOURCE_DISABLED)
 667                         p = string(p, pend, " disabled", str_spec);
 668         } else {
 669                 p = string(p, pend, " flags ", str_spec);
 670                 p = number(p, pend, res->flags, flag_spec);
 671         }
 672         *p++ = ']';
 673         *p = '\0';
 674
 675         return string(buf, end, sym, spec);
 676 }
 677
 678 static char *mac_address_string(char *buf, char *end, u8 *addr,
 679                                 struct printf_spec spec, const char *fmt)
 680 {
 681         char mac_addr[sizeof("xx:xx:xx:xx:xx:xx")];
 682         char *p = mac_addr;
 683         int i;
 684
 685         for (i = 0; i < 6; i++) {
 686                 p = pack_hex_byte(p, addr[i]);
 687                 if (fmt[0] == 'M' && i != 5)
 688                         *p++ = ':';
 689         }
 690         *p = '\0';
 691
 692         return string(buf, end, mac_addr, spec);
 693 }
 694
 695 static char *ip4_string(char *p, const u8 *addr, bool leading_zeros)
 696 {
 697         int i;
 698
 699         for (i = 0; i < 4; i++) {
 700                 char temp[3];   /* hold each IP quad in reverse order */
 701                 int digits = put_dec_trunc(temp, addr[i]) - temp;
 702                 if (leading_zeros) {
 703                         if (digits < 3)
 704                                 *p++ = '0';
 705                         if (digits < 2)
 706                                 *p++ = '0';
 707                 }
 708                 /* reverse the digits in the quad */
 709                 while (digits--)
 710                         *p++ = temp[digits];
 711                 if (i < 3)
 712                         *p++ = '.';
 713         }
 714         *p = '\0';
 715
 716         return p;
 717 }
 718
 719 static char *ip6_compressed_string(char *p, const char *addr)
 720 {
 721         int i, j, range;
 722         unsigned char zerolength[8];
 723         int longest = 1;
 724         int colonpos = -1;
 725         u16 word;
 726         u8 hi, lo;
 727         bool needcolon = false;
 728         bool useIPv4;
 729         struct in6_addr in6;
 730
 731         memcpy(&in6, addr, sizeof(struct in6_addr));
 732
 733         useIPv4 = ipv6_addr_v4mapped(&in6) || ipv6_addr_is_isatap(&in6);
 734
 735         memset(zerolength, 0, sizeof(zerolength));
 736
 737         if (useIPv4)
 738                 range = 6;
 739         else
 740                 range = 8;
 741
 742         /* find position of longest 0 run */
 743         for (i = 0; i < range; i++) {
 744                 for (j = i; j < range; j++) {
 745                         if (in6.s6_addr16[j] != 0)
 746                                 break;
 747                         zerolength[i]++;
 748                 }
 749         }
 750         for (i = 0; i < range; i++) {
 751                 if (zerolength[i] > longest) {
 752                         longest = zerolength[i];
 753                         colonpos = i;
 754                 }
 755         }
 756
 757         /* emit address */
 758         for (i = 0; i < range; i++) {
 759                 if (i == colonpos) {
 760                         if (needcolon || i == 0)
 761                                 *p++ = ':';
 762                         *p++ = ':';
 763                         needcolon = false;
 764                         i += longest - 1;
 765                         continue;
 766                 }
 767                 if (needcolon) {
 768                         *p++ = ':';
 769                         needcolon = false;
 770                 }
 771                 /* hex u16 without leading 0s */
 772                 word = ntohs(in6.s6_addr16[i]);
 773                 hi = word >> 8;
 774                 lo = word & 0xff;
 775                 if (hi) {
 776                         if (hi > 0x0f)
 777                                 p = pack_hex_byte(p, hi);
 778                         else
 779                                 *p++ = hex_asc_lo(hi);
 780                         p = pack_hex_byte(p, lo);
 781                 }
 782                 else if (lo > 0x0f)
 783                         p = pack_hex_byte(p, lo);
 784                 else
 785                         *p++ = hex_asc_lo(lo);
 786                 needcolon = true;
 787         }
 788
 789         if (useIPv4) {
 790                 if (needcolon)
 791                         *p++ = ':';
 792                 p = ip4_string(p, &in6.s6_addr[12], false);
 793         }
 794         *p = '\0';
 795
 796         return p;
 797 }
 798
 799 static char *ip6_string(char *p, const char *addr, const char *fmt)
 800 {
 801         int i;
 802
 803         for (i = 0; i < 8; i++) {
 804                 p = pack_hex_byte(p, *addr++);
 805                 p = pack_hex_byte(p, *addr++);
 806                 if (fmt[0] == 'I' && i != 7)
 807                         *p++ = ':';
 808         }
 809         *p = '\0';
 810
 811         return p;
 812 }
 813
 814 static char *ip6_addr_string(char *buf, char *end, const u8 *addr,
 815                              struct printf_spec spec, const char *fmt)
 816 {
 817         char ip6_addr[sizeof("xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255")];
 818
 819         if (fmt[0] == 'I' && fmt[2] == 'c')
 820                 ip6_compressed_string(ip6_addr, addr);
 821         else
 822                 ip6_string(ip6_addr, addr, fmt);
 823
 824         return string(buf, end, ip6_addr, spec);
 825 }
 826
 827 static char *ip4_addr_string(char *buf, char *end, const u8 *addr,
 828                              struct printf_spec spec, const char *fmt)
 829 {
 830         char ip4_addr[sizeof("255.255.255.255")];
 831
 832         ip4_string(ip4_addr, addr, fmt[0] == 'i');
 833
 834         return string(buf, end, ip4_addr, spec);
 835 }
 836
 837 static char *uuid_string(char *buf, char *end, const u8 *addr,
 838                          struct printf_spec spec, const char *fmt)
 839 {
 840         char uuid[sizeof("xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx")];
 841         char *p = uuid;
 842         int i;
 843         static const u8 be[16] = {0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15};
 844         static const u8 le[16] = {3,2,1,0,5,4,7,6,8,9,10,11,12,13,14,15};
 845         const u8 *index = be;
 846         bool uc = false;
 847
 848         switch (*(++fmt)) {
 849         case 'L':
 850                 uc = true;              /* fall-through */
 851         case 'l':
 852                 index = le;
 853                 break;
 854         case 'B':
 855                 uc = true;
 856                 break;
 857         }
 858
 859         for (i = 0; i < 16; i++) {
 860                 p = pack_hex_byte(p, addr[index[i]]);
 861                 switch (i) {
 862                 case 3:
 863                 case 5:
 864                 case 7:
 865                 case 9:
 866                         *p++ = '-';
 867                         break;
 868                 }
 869         }
 870
 871         *p = 0;
 872
 873         if (uc) {
 874                 p = uuid;
 875                 do {
 876                         *p = toupper(*p);
 877                 } while (*(++p));
 878         }
 879
 880         return string(buf, end, uuid, spec);
 881 }
 882
 883 /*
 884  * Show a '%p' thing.  A kernel extension is that the '%p' is followed
 885  * by an extra set of alphanumeric characters that are extended format
 886  * specifiers.
 887  *
 888  * Right now we handle:
 889  *
 890  * - 'F' For symbolic function descriptor pointers with offset
 891  * - 'f' For simple symbolic function names without offset
 892  * - 'S' For symbolic direct pointers with offset
 893  * - 's' For symbolic direct pointers without offset
 894  * - 'R' For decoded struct resource, e.g., [mem 0x0-0x1f 64bit pref]
 895  * - 'r' For raw struct resource, e.g., [mem 0x0-0x1f flags 0x201]
 896  * - 'M' For a 6-byte MAC address, it prints the address in the
 897  *       usual colon-separated hex notation
 898  * - 'm' For a 6-byte MAC address, it prints the hex address without colons
 899  * - 'I' [46] for IPv4/IPv6 addresses printed in the usual way
 900  *       IPv4 uses dot-separated decimal without leading 0's (1.2.3.4)
 901  *       IPv6 uses colon separated network-order 16 bit hex with leading 0's
 902  * - 'i' [46] for 'raw' IPv4/IPv6 addresses
 903  *       IPv6 omits the colons (01020304...0f)
 904  *       IPv4 uses dot-separated decimal with leading 0's (010.123.045.006)
 905  * - 'I6c' for IPv6 addresses printed as specified by
 906  *       http://www.ietf.org/id/draft-kawamura-ipv6-text-representation-03.txt
 907  * - 'U' For a 16 byte UUID/GUID, it prints the UUID/GUID in the form
 908  *       "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx"
 909  *       Options for %pU are:
 910  *         b big endian lower case hex (default)
 911  *         B big endian UPPER case hex
 912  *         l little endian lower case hex
 913  *         L little endian UPPER case hex
 914  *           big endian output byte order is:
 915  *             [0][1][2][3]-[4][5]-[6][7]-[8][9]-[10][11][12][13][14][15]
 916  *           little endian output byte order is:
 917  *             [3][2][1][0]-[5][4]-[7][6]-[8][9]-[10][11][12][13][14][15]
 918  *
 919  * Note: The difference between 'S' and 'F' is that on ia64 and ppc64
 920  * function pointers are really function descriptors, which contain a
 921  * pointer to the real address.
 922  */
 923 static char *pointer(const char *fmt, char *buf, char *end, void *ptr,
 924                         struct printf_spec spec)
 925 {
 926         if (!ptr)
 927                 return string(buf, end, "(null)", spec);
 928
 929         switch (*fmt) {
 930         case 'F':
 931         case 'f':
 932                 ptr = dereference_function_descriptor(ptr);
 933                 /* Fallthrough */
 934         case 'S':
 935         case 's':
 936                 return symbol_string(buf, end, ptr, spec, *fmt);
 937         case 'R':
 938         case 'r':
 939                 return resource_string(buf, end, ptr, spec, fmt);
 940         case 'M':                       /* Colon separated: 00:01:02:03:04:05 */
 941         case 'm':                       /* Contiguous: 000102030405 */
 942                 return mac_address_string(buf, end, ptr, spec, fmt);
 943         case 'I':                       /* Formatted IP supported
 944                                          * 4:   1.2.3.4
 945                                          * 6:   0001:0203:...:0708
 946                                          * 6c:  1::708 or 1::1.2.3.4
 947                                          */
 948         case 'i':                       /* Contiguous:
 949                                          * 4:   001.002.003.004
 950                                          * 6:   000102...0f
 951                                          */
 952                 switch (fmt[1]) {
 953                 case '6':
 954                         return ip6_addr_string(buf, end, ptr, spec, fmt);
 955                 case '4':
 956                         return ip4_addr_string(buf, end, ptr, spec, fmt);
 957                 }
 958                 break;
 959         case 'U':
 960                 return uuid_string(buf, end, ptr, spec, fmt);
 961         }
 962         spec.flags |= SMALL;
 963         if (spec.field_width == -1) {
 964                 spec.field_width = 2*sizeof(void *);
 965                 spec.flags |= ZEROPAD;
 966         }
 967         spec.base = 16;
 968
 969         return number(buf, end, (unsigned long) ptr, spec);
 970 }
 971
 972 /*
 973  * Helper function to decode printf style format.
 974  * Each call decode a token from the format and return the
 975  * number of characters read (or likely the delta where it wants
 976  * to go on the next call).
 977  * The decoded token is returned through the parameters
 978  *
 979  * 'h', 'l', or 'L' for integer fields
 980  * 'z' support added 23/7/1999 S.H.
 981  * 'z' changed to 'Z' --davidm 1/25/99
 982  * 't' added for ptrdiff_t
 983  *
 984  * @fmt: the format string
 985  * @type of the token returned
 986  * @flags: various flags such as +, -, # tokens..
 987  * @field_width: overwritten width
 988  * @base: base of the number (octal, hex, ...)
 989  * @precision: precision of a number
 990  * @qualifier: qualifier of a number (long, size_t, ...)
 991  */
 992 static int format_decode(const char *fmt, struct printf_spec *spec)
 993 {
 994         const char *start = fmt;
 995
 996         /* we finished early by reading the field width */
 997         if (spec->type == FORMAT_TYPE_WIDTH) {
 998                 if (spec->field_width < 0) {
 999                         spec->field_width = -spec->field_width;
1000                         spec->flags |= LEFT;
1001                 }
1002                 spec->type = FORMAT_TYPE_NONE;
1003                 goto precision;
1004         }
1005
1006         /* we finished early by reading the precision */
1007         if (spec->type == FORMAT_TYPE_PRECISION) {
1008                 if (spec->precision < 0)
1009                         spec->precision = 0;
1010
1011                 spec->type = FORMAT_TYPE_NONE;
1012                 goto qualifier;
1013         }
1014
1015         /* By default */
1016         spec->type = FORMAT_TYPE_NONE;
1017
1018         for (; *fmt ; ++fmt) {
1019                 if (*fmt == '%')
1020                         break;
1021         }
1022
1023         /* Return the current non-format string */
1024         if (fmt != start || !*fmt)
1025                 return fmt - start;
1026
1027         /* Process flags */
1028         spec->flags = 0;
1029
1030         while (1) { /* this also skips first '%' */
1031                 bool found = true;
1032
1033                 ++fmt;
1034
1035                 switch (*fmt) {
1036                 case '-': spec->flags |= LEFT;    break;
1037                 case '+': spec->flags |= PLUS;    break;
1038                 case ' ': spec->flags |= SPACE;   break;
1039                 case '#': spec->flags |= SPECIAL; break;
1040                 case '0': spec->flags |= ZEROPAD; break;
1041                 default:  found = false;
1042                 }
1043
1044                 if (!found)
1045                         break;
1046         }
1047
1048         /* get field width */
1049         spec->field_width = -1;
1050
1051         if (isdigit(*fmt))
1052                 spec->field_width = skip_atoi(&fmt);
1053         else if (*fmt == '*') {
1054                 /* it's the next argument */
1055                 spec->type = FORMAT_TYPE_WIDTH;
1056                 return ++fmt - start;
1057         }
1058
1059 precision:
1060         /* get the precision */
1061         spec->precision = -1;
1062         if (*fmt == '.') {
1063                 ++fmt;
1064                 if (isdigit(*fmt)) {
1065                         spec->precision = skip_atoi(&fmt);
1066                         if (spec->precision < 0)
1067                                 spec->precision = 0;
1068                 } else if (*fmt == '*') {
1069                         /* it's the next argument */
1070                         spec->type = FORMAT_TYPE_PRECISION;
1071                         return ++fmt - start;
1072                 }
1073         }
1074
1075 qualifier:
1076         /* get the conversion qualifier */
1077         spec->qualifier = -1;
1078         if (*fmt == 'h' || TOLOWER(*fmt) == 'l' ||
1079             TOLOWER(*fmt) == 'z' || *fmt == 't') {
1080                 spec->qualifier = *fmt++;
1081                 if (unlikely(spec->qualifier == *fmt)) {
1082                         if (spec->qualifier == 'l') {
1083                                 spec->qualifier = 'L';
1084                                 ++fmt;
1085                         } else if (spec->qualifier == 'h') {
1086                                 spec->qualifier = 'H';
1087                                 ++fmt;
1088                         }
1089                 }
1090         }
1091
1092         /* default base */
1093         spec->base = 10;
1094         switch (*fmt) {
1095         case 'c':
1096                 spec->type = FORMAT_TYPE_CHAR;
1097                 return ++fmt - start;
1098
1099         case 's':
1100                 spec->type = FORMAT_TYPE_STR;
1101                 return ++fmt - start;
1102
1103         case 'p':
1104                 spec->type = FORMAT_TYPE_PTR;
1105                 return fmt - start;
1106                 /* skip alnum */
1107
1108         case 'n':
1109                 spec->type = FORMAT_TYPE_NRCHARS;
1110                 return ++fmt - start;
1111
1112         case '%':
1113                 spec->type = FORMAT_TYPE_PERCENT_CHAR;
1114                 return ++fmt - start;
1115
1116         /* integer number formats - set up the flags and "break" */
1117         case 'o':
1118                 spec->base = 8;
1119                 break;
1120
1121         case 'x':
1122                 spec->flags |= SMALL;
1123
1124         case 'X':
1125                 spec->base = 16;
1126                 break;
1127
1128         case 'd':
1129         case 'i':
1130                 spec->flags |= SIGN;
1131         case 'u':
1132                 break;
1133
1134         default:
1135                 spec->type = FORMAT_TYPE_INVALID;
1136                 return fmt - start;
1137         }
1138
1139         if (spec->qualifier == 'L')
1140                 spec->type = FORMAT_TYPE_LONG_LONG;
1141         else if (spec->qualifier == 'l') {
1142                 if (spec->flags & SIGN)
1143                         spec->type = FORMAT_TYPE_LONG;
1144                 else
1145                         spec->type = FORMAT_TYPE_ULONG;
1146         } else if (TOLOWER(spec->qualifier) == 'z') {
1147                 spec->type = FORMAT_TYPE_SIZE_T;
1148         } else if (spec->qualifier == 't') {
1149                 spec->type = FORMAT_TYPE_PTRDIFF;
1150         } else if (spec->qualifier == 'H') {
1151                 if (spec->flags & SIGN)
1152                         spec->type = FORMAT_TYPE_BYTE;
1153                 else
1154                         spec->type = FORMAT_TYPE_UBYTE;
1155         } else if (spec->qualifier == 'h') {
1156                 if (spec->flags & SIGN)
1157                         spec->type = FORMAT_TYPE_SHORT;
1158                 else
1159                         spec->type = FORMAT_TYPE_USHORT;
1160         } else {
1161                 if (spec->flags & SIGN)
1162                         spec->type = FORMAT_TYPE_INT;
1163                 else
1164                         spec->type = FORMAT_TYPE_UINT;
1165         }
1166
1167         return ++fmt - start;
1168 }
1169
1170 /**
1171  * vsnprintf - Format a string and place it in a buffer
1172  * @buf: The buffer to place the result into
1173  * @size: The size of the buffer, including the trailing null space
1174  * @fmt: The format string to use
1175  * @args: Arguments for the format string
1176  *
1177  * This function follows C99 vsnprintf, but has some extensions:
1178  * %pS output the name of a text symbol with offset
1179  * %ps output the name of a text symbol without offset
1180  * %pF output the name of a function pointer with its offset
1181  * %pf output the name of a function pointer without its offset
1182  * %pR output the address range in a struct resource
1183  * %n is ignored
1184  *
1185  * The return value is the number of characters which would
1186  * be generated for the given input, excluding the trailing
1187  * '\0', as per ISO C99. If you want to have the exact
1188  * number of characters written into @buf as return value
1189  * (not including the trailing '\0'), use vscnprintf(). If the
1190  * return is greater than or equal to @size, the resulting
1191  * string is truncated.
1192  *
1193  * Call this function if you are already dealing with a va_list.
1194  * You probably want snprintf() instead.
1195  */
1196 int vsnprintf(char *buf, size_t size, const char *fmt, va_list args)
1197 {
1198         unsigned long long num;
1199         char *str, *end;
1200         struct printf_spec spec = {0};
1201
1202         /* Reject out-of-range values early.  Large positive sizes are
1203            used for unknown buffer sizes. */
1204         if (WARN_ON_ONCE((int) size < 0))
1205                 return 0;
1206
1207         str = buf;
1208         end = buf + size;
1209
1210         /* Make sure end is always >= buf */
1211         if (end < buf) {
1212                 end = ((void *)-1);
1213                 size = end - buf;
1214         }
1215
1216         while (*fmt) {
1217                 const char *old_fmt = fmt;
1218                 int read = format_decode(fmt, &spec);
1219
1220                 fmt += read;
1221
1222                 switch (spec.type) {
1223                 case FORMAT_TYPE_NONE: {
1224                         int copy = read;
1225                         if (str < end) {
1226                                 if (copy > end - str)
1227                                         copy = end - str;
1228                                 memcpy(str, old_fmt, copy);
1229                         }
1230                         str += read;
1231                         break;
1232                 }
1233
1234                 case FORMAT_TYPE_WIDTH:
1235                         spec.field_width = va_arg(args, int);
1236                         break;
1237
1238                 case FORMAT_TYPE_PRECISION:
1239                         spec.precision = va_arg(args, int);
1240                         break;
1241
1242                 case FORMAT_TYPE_CHAR: {
1243                         char c;
1244
1245                         if (!(spec.flags & LEFT)) {
1246                                 while (--spec.field_width > 0) {
1247                                         if (str < end)
1248                                                 *str = ' ';
1249                                         ++str;
1250
1251                                 }
1252                         }
1253                         c = (unsigned char) va_arg(args, int);
1254                         if (str < end)
1255                                 *str = c;
1256                         ++str;
1257                         while (--spec.field_width > 0) {
1258                                 if (str < end)
1259                                         *str = ' ';
1260                                 ++str;
1261                         }
1262                         break;
1263                 }
1264
1265                 case FORMAT_TYPE_STR:
1266                         str = string(str, end, va_arg(args, char *), spec);
1267                         break;
1268
1269                 case FORMAT_TYPE_PTR:
1270                         str = pointer(fmt+1, str, end, va_arg(args, void *),
1271                                       spec);
1272                         while (isalnum(*fmt))
1273                                 fmt++;
1274                         break;
1275
1276                 case FORMAT_TYPE_PERCENT_CHAR:
1277                         if (str < end)
1278                                 *str = '%';
1279                         ++str;
1280                         break;
1281
1282                 case FORMAT_TYPE_INVALID:
1283                         if (str < end)
1284                                 *str = '%';
1285                         ++str;
1286                         break;
1287
1288                 case FORMAT_TYPE_NRCHARS: {
1289                         int qualifier = spec.qualifier;
1290
1291                         if (qualifier == 'l') {
1292                                 long *ip = va_arg(args, long *);
1293                                 *ip = (str - buf);
1294                         } else if (TOLOWER(qualifier) == 'z') {
1295                                 size_t *ip = va_arg(args, size_t *);
1296                                 *ip = (str - buf);
1297                         } else {
1298                                 int *ip = va_arg(args, int *);
1299                                 *ip = (str - buf);
1300                         }
1301                         break;
1302                 }
1303
1304                 default:
1305                         switch (spec.type) {
1306                         case FORMAT_TYPE_LONG_LONG:
1307                                 num = va_arg(args, long long);
1308                                 break;
1309                         case FORMAT_TYPE_ULONG:
1310                                 num = va_arg(args, unsigned long);
1311                                 break;
1312                         case FORMAT_TYPE_LONG:
1313                                 num = va_arg(args, long);
1314                                 break;
1315                         case FORMAT_TYPE_SIZE_T:
1316                                 num = va_arg(args, size_t);
1317                                 break;
1318                         case FORMAT_TYPE_PTRDIFF:
1319                                 num = va_arg(args, ptrdiff_t);
1320                                 break;
1321                         case FORMAT_TYPE_UBYTE:
1322                                 num = (unsigned char) va_arg(args, int);
1323                                 break;
1324                         case FORMAT_TYPE_BYTE:
1325                                 num = (signed char) va_arg(args, int);
1326                                 break;
1327                         case FORMAT_TYPE_USHORT:
1328                                 num = (unsigned short) va_arg(args, int);
1329                                 break;
1330                         case FORMAT_TYPE_SHORT:
1331                                 num = (short) va_arg(args, int);
1332                                 break;
1333                         case FORMAT_TYPE_INT:
1334                                 num = (int) va_arg(args, int);
1335                                 break;
1336                         default:
1337                                 num = va_arg(args, unsigned int);
1338                         }
1339
1340                         str = number(str, end, num, spec);
1341                 }
1342         }
1343
1344         if (size > 0) {
1345                 if (str < end)
1346                         *str = '\0';
1347                 else
1348                         end[-1] = '\0';
1349         }
1350
1351         /* the trailing null byte doesn't count towards the total */
1352         return str-buf;
1353
1354 }
1355 EXPORT_SYMBOL(vsnprintf);
1356
1357 /**
1358  * vscnprintf - Format a string and place it in a buffer
1359  * @buf: The buffer to place the result into
1360  * @size: The size of the buffer, including the trailing null space
1361  * @fmt: The format string to use
1362  * @args: Arguments for the format string
1363  *
1364  * The return value is the number of characters which have been written into
1365  * the @buf not including the trailing '\0'. If @size is <= 0 the function
1366  * returns 0.
1367  *
1368  * Call this function if you are already dealing with a va_list.
1369  * You probably want scnprintf() instead.
1370  *
1371  * See the vsnprintf() documentation for format string extensions over C99.
1372  */
1373 int vscnprintf(char *buf, size_t size, const char *fmt, va_list args)
1374 {
1375         int i;
1376
1377         i = vsnprintf(buf, size, fmt, args);
1378
1379         return (i >= size) ? (size - 1) : i;
1380 }
1381 EXPORT_SYMBOL(vscnprintf);
1382
1383 /**
1384  * snprintf - Format a string and place it in a buffer
1385  * @buf: The buffer to place the result into
1386  * @size: The size of the buffer, including the trailing null space
1387  * @fmt: The format string to use
1388  * @...: Arguments for the format string
1389  *
1390  * The return value is the number of characters which would be
1391  * generated for the given input, excluding the trailing null,
1392  * as per ISO C99.  If the return is greater than or equal to
1393  * @size, the resulting string is truncated.
1394  *
1395  * See the vsnprintf() documentation for format string extensions over C99.
1396  */
1397 int snprintf(char *buf, size_t size, const char *fmt, ...)
1398 {
1399         va_list args;
1400         int i;
1401
1402         va_start(args, fmt);
1403         i = vsnprintf(buf, size, fmt, args);
1404         va_end(args);
1405
1406         return i;
1407 }
1408 EXPORT_SYMBOL(snprintf);
1409
1410 /**
1411  * scnprintf - Format a string and place it in a buffer
1412  * @buf: The buffer to place the result into
1413  * @size: The size of the buffer, including the trailing null space
1414  * @fmt: The format string to use
1415  * @...: Arguments for the format string
1416  *
1417  * The return value is the number of characters written into @buf not including
1418  * the trailing '\0'. If @size is <= 0 the function returns 0.
1419  */
1420
1421 int scnprintf(char *buf, size_t size, const char *fmt, ...)
1422 {
1423         va_list args;
1424         int i;
1425
1426         va_start(args, fmt);
1427         i = vsnprintf(buf, size, fmt, args);
1428         va_end(args);
1429
1430         return (i >= size) ? (size - 1) : i;
1431 }
1432 EXPORT_SYMBOL(scnprintf);
1433
1434 /**
1435  * vsprintf - Format a string and place it in a buffer
1436  * @buf: The buffer to place the result into
1437  * @fmt: The format string to use
1438  * @args: Arguments for the format string
1439  *
1440  * The function returns the number of characters written
1441  * into @buf. Use vsnprintf() or vscnprintf() in order to avoid
1442  * buffer overflows.
1443  *
1444  * Call this function if you are already dealing with a va_list.
1445  * You probably want sprintf() instead.
1446  *
1447  * See the vsnprintf() documentation for format string extensions over C99.
1448  */
1449 int vsprintf(char *buf, const char *fmt, va_list args)
1450 {
1451         return vsnprintf(buf, INT_MAX, fmt, args);
1452 }
1453 EXPORT_SYMBOL(vsprintf);
1454
1455 /**
1456  * sprintf - Format a string and place it in a buffer
1457  * @buf: The buffer to place the result into
1458  * @fmt: The format string to use
1459  * @...: Arguments for the format string
1460  *
1461  * The function returns the number of characters written
1462  * into @buf. Use snprintf() or scnprintf() in order to avoid
1463  * buffer overflows.
1464  *
1465  * See the vsnprintf() documentation for format string extensions over C99.
1466  */
1467 int sprintf(char *buf, const char *fmt, ...)
1468 {
1469         va_list args;
1470         int i;
1471
1472         va_start(args, fmt);
1473         i = vsnprintf(buf, INT_MAX, fmt, args);
1474         va_end(args);
1475
1476         return i;
1477 }
1478 EXPORT_SYMBOL(sprintf);
1479
1480 #ifdef CONFIG_BINARY_PRINTF
1481 /*
1482  * bprintf service:
1483  * vbin_printf() - VA arguments to binary data
1484  * bstr_printf() - Binary data to text string
1485  */
1486
1487 /**
1488  * vbin_printf - Parse a format string and place args' binary value in a buffer
1489  * @bin_buf: The buffer to place args' binary value
1490  * @size: The size of the buffer(by words(32bits), not characters)
1491  * @fmt: The format string to use
1492  * @args: Arguments for the format string
1493  *
1494  * The format follows C99 vsnprintf, except %n is ignored, and its argument
1495  * is skiped.
1496  *
1497  * The return value is the number of words(32bits) which would be generated for
1498  * the given input.
1499  *
1500  * NOTE:
1501  * If the return value is greater than @size, the resulting bin_buf is NOT
1502  * valid for bstr_printf().
1503  */
1504 int vbin_printf(u32 *bin_buf, size_t size, const char *fmt, va_list args)
1505 {
1506         struct printf_spec spec = {0};
1507         char *str, *end;
1508
1509         str = (char *)bin_buf;
1510         end = (char *)(bin_buf + size);
1511
1512 #define save_arg(type)                                                  \
1513 do {                                                                    \
1514         if (sizeof(type) == 8) {                                        \
1515                 unsigned long long value;                               \
1516                 str = PTR_ALIGN(str, sizeof(u32));                      \
1517                 value = va_arg(args, unsigned long long);               \
1518                 if (str + sizeof(type) <= end) {                        \
1519                         *(u32 *)str = *(u32 *)&value;                   \
1520                         *(u32 *)(str + 4) = *((u32 *)&value + 1);       \
1521                 }                                                       \
1522         } else {                                                        \
1523                 unsigned long value;                                    \
1524                 str = PTR_ALIGN(str, sizeof(type));                     \
1525                 value = va_arg(args, int);                              \
1526                 if (str + sizeof(type) <= end)                          \
1527                         *(typeof(type) *)str = (type)value;             \
1528         }                                                               \
1529         str += sizeof(type);                                            \
1530 } while (0)
1531
1532         while (*fmt) {
1533                 int read = format_decode(fmt, &spec);
1534
1535                 fmt += read;
1536
1537                 switch (spec.type) {
1538                 case FORMAT_TYPE_NONE:
1539                 case FORMAT_TYPE_INVALID:
1540                 case FORMAT_TYPE_PERCENT_CHAR:
1541                         break;
1542
1543                 case FORMAT_TYPE_WIDTH:
1544                 case FORMAT_TYPE_PRECISION:
1545                         save_arg(int);
1546                         break;
1547
1548                 case FORMAT_TYPE_CHAR:
1549                         save_arg(char);
1550                         break;
1551
1552                 case FORMAT_TYPE_STR: {
1553                         const char *save_str = va_arg(args, char *);
1554                         size_t len;
1555
1556                         if ((unsigned long)save_str > (unsigned long)-PAGE_SIZE
1557                                         || (unsigned long)save_str < PAGE_SIZE)
1558                                 save_str = "(null)";
1559                         len = strlen(save_str) + 1;
1560                         if (str + len < end)
1561                                 memcpy(str, save_str, len);
1562                         str += len;
1563                         break;
1564                 }
1565
1566                 case FORMAT_TYPE_PTR:
1567                         save_arg(void *);
1568                         /* skip all alphanumeric pointer suffixes */
1569                         while (isalnum(*fmt))
1570                                 fmt++;
1571                         break;
1572
1573                 case FORMAT_TYPE_NRCHARS: {
1574                         /* skip %n 's argument */
1575                         int qualifier = spec.qualifier;
1576                         void *skip_arg;
1577                         if (qualifier == 'l')
1578                                 skip_arg = va_arg(args, long *);
1579                         else if (TOLOWER(qualifier) == 'z')
1580                                 skip_arg = va_arg(args, size_t *);
1581                         else
1582                                 skip_arg = va_arg(args, int *);
1583                         break;
1584                 }
1585
1586                 default:
1587                         switch (spec.type) {
1588
1589                         case FORMAT_TYPE_LONG_LONG:
1590                                 save_arg(long long);
1591                                 break;
1592                         case FORMAT_TYPE_ULONG:
1593                         case FORMAT_TYPE_LONG:
1594                                 save_arg(unsigned long);
1595                                 break;
1596                         case FORMAT_TYPE_SIZE_T:
1597                                 save_arg(size_t);
1598                                 break;
1599                         case FORMAT_TYPE_PTRDIFF:
1600                                 save_arg(ptrdiff_t);
1601                                 break;
1602                         case FORMAT_TYPE_UBYTE:
1603                         case FORMAT_TYPE_BYTE:
1604                                 save_arg(char);
1605                                 break;
1606                         case FORMAT_TYPE_USHORT:
1607                         case FORMAT_TYPE_SHORT:
1608                                 save_arg(short);
1609                                 break;
1610                         default:
1611                                 save_arg(int);
1612                         }
1613                 }
1614         }
1615
1616         return (u32 *)(PTR_ALIGN(str, sizeof(u32))) - bin_buf;
1617 #undef save_arg
1618 }
1619 EXPORT_SYMBOL_GPL(vbin_printf);
1620
1621 /**
1622  * bstr_printf - Format a string from binary arguments and place it in a buffer
1623  * @buf: The buffer to place the result into
1624  * @size: The size of the buffer, including the trailing null space
1625  * @fmt: The format string to use
1626  * @bin_buf: Binary arguments for the format string
1627  *
1628  * This function like C99 vsnprintf, but the difference is that vsnprintf gets
1629  * arguments from stack, and bstr_printf gets arguments from @bin_buf which is
1630  * a binary buffer that generated by vbin_printf.
1631  *
1632  * The format follows C99 vsnprintf, but has some extensions:
1633  *  see vsnprintf comment for details.
1634  *
1635  * The return value is the number of characters which would
1636  * be generated for the given input, excluding the trailing
1637  * '\0', as per ISO C99. If you want to have the exact
1638  * number of characters written into @buf as return value
1639  * (not including the trailing '\0'), use vscnprintf(). If the
1640  * return is greater than or equal to @size, the resulting
1641  * string is truncated.
1642  */
1643 int bstr_printf(char *buf, size_t size, const char *fmt, const u32 *bin_buf)
1644 {
1645         struct printf_spec spec = {0};
1646         char *str, *end;
1647         const char *args = (const char *)bin_buf;
1648
1649         if (WARN_ON_ONCE((int) size < 0))
1650                 return 0;
1651
1652         str = buf;
1653         end = buf + size;
1654
1655 #define get_arg(type)                                                   \
1656 ({                                                                      \
1657         typeof(type) value;                                             \
1658         if (sizeof(type) == 8) {                                        \
1659                 args = PTR_ALIGN(args, sizeof(u32));                    \
1660                 *(u32 *)&value = *(u32 *)args;                          \
1661                 *((u32 *)&value + 1) = *(u32 *)(args + 4);              \
1662         } else {                                                        \
1663                 args = PTR_ALIGN(args, sizeof(type));                   \
1664                 value = *(typeof(type) *)args;                          \
1665         }                                                               \
1666         args += sizeof(type);                                           \
1667         value;                                                          \
1668 })
1669
1670         /* Make sure end is always >= buf */
1671         if (end < buf) {
1672                 end = ((void *)-1);
1673                 size = end - buf;
1674         }
1675
1676         while (*fmt) {
1677                 const char *old_fmt = fmt;
1678                 int read = format_decode(fmt, &spec);
1679
1680                 fmt += read;
1681
1682                 switch (spec.type) {
1683                 case FORMAT_TYPE_NONE: {
1684                         int copy = read;
1685                         if (str < end) {
1686                                 if (copy > end - str)
1687                                         copy = end - str;
1688                                 memcpy(str, old_fmt, copy);
1689                         }
1690                         str += read;
1691                         break;
1692                 }
1693
1694                 case FORMAT_TYPE_WIDTH:
1695                         spec.field_width = get_arg(int);
1696                         break;
1697
1698                 case FORMAT_TYPE_PRECISION:
1699                         spec.precision = get_arg(int);
1700                         break;
1701
1702                 case FORMAT_TYPE_CHAR: {
1703                         char c;
1704
1705                         if (!(spec.flags & LEFT)) {
1706                                 while (--spec.field_width > 0) {
1707                                         if (str < end)
1708                                                 *str = ' ';
1709                                         ++str;
1710                                 }
1711                         }
1712                         c = (unsigned char) get_arg(char);
1713                         if (str < end)
1714                                 *str = c;
1715                         ++str;
1716                         while (--spec.field_width > 0) {
1717                                 if (str < end)
1718                                         *str = ' ';
1719                                 ++str;
1720                         }
1721                         break;
1722                 }
1723
1724                 case FORMAT_TYPE_STR: {
1725                         const char *str_arg = args;
1726                         args += strlen(str_arg) + 1;
1727                         str = string(str, end, (char *)str_arg, spec);
1728                         break;
1729                 }
1730
1731                 case FORMAT_TYPE_PTR:
1732                         str = pointer(fmt+1, str, end, get_arg(void *), spec);
1733                         while (isalnum(*fmt))
1734                                 fmt++;
1735                         break;
1736
1737                 case FORMAT_TYPE_PERCENT_CHAR:
1738                 case FORMAT_TYPE_INVALID:
1739                         if (str < end)
1740                                 *str = '%';
1741                         ++str;
1742                         break;
1743
1744                 case FORMAT_TYPE_NRCHARS:
1745                         /* skip */
1746                         break;
1747
1748                 default: {
1749                         unsigned long long num;
1750
1751                         switch (spec.type) {
1752
1753                         case FORMAT_TYPE_LONG_LONG:
1754                                 num = get_arg(long long);
1755                                 break;
1756                         case FORMAT_TYPE_ULONG:
1757                         case FORMAT_TYPE_LONG:
1758                                 num = get_arg(unsigned long);
1759                                 break;
1760                         case FORMAT_TYPE_SIZE_T:
1761                                 num = get_arg(size_t);
1762                                 break;
1763                         case FORMAT_TYPE_PTRDIFF:
1764                                 num = get_arg(ptrdiff_t);
1765                                 break;
1766                         case FORMAT_TYPE_UBYTE:
1767                                 num = get_arg(unsigned char);
1768                                 break;
1769                         case FORMAT_TYPE_BYTE:
1770                                 num = get_arg(signed char);
1771                                 break;
1772                         case FORMAT_TYPE_USHORT:
1773                                 num = get_arg(unsigned short);
1774                                 break;
1775                         case FORMAT_TYPE_SHORT:
1776                                 num = get_arg(short);
1777                                 break;
1778                         case FORMAT_TYPE_UINT:
1779                                 num = get_arg(unsigned int);
1780                                 break;
1781                         default:
1782                                 num = get_arg(int);
1783                         }
1784
1785                         str = number(str, end, num, spec);
1786                 } /* default: */
1787                 } /* switch(spec.type) */
1788         } /* while(*fmt) */
1789
1790         if (size > 0) {
1791                 if (str < end)
1792                         *str = '\0';
1793                 else
1794                         end[-1] = '\0';
1795         }
1796
1797 #undef get_arg
1798
1799         /* the trailing null byte doesn't count towards the total */
1800         return str - buf;
1801 }
1802 EXPORT_SYMBOL_GPL(bstr_printf);
1803
1804 /**
1805  * bprintf - Parse a format string and place args' binary value in a buffer
1806  * @bin_buf: The buffer to place args' binary value
1807  * @size: The size of the buffer(by words(32bits), not characters)
1808  * @fmt: The format string to use
1809  * @...: Arguments for the format string
1810  *
1811  * The function returns the number of words(u32) written
1812  * into @bin_buf.
1813  */
1814 int bprintf(u32 *bin_buf, size_t size, const char *fmt, ...)
1815 {
1816         va_list args;
1817         int ret;
1818
1819         va_start(args, fmt);
1820         ret = vbin_printf(bin_buf, size, fmt, args);
1821         va_end(args);
1822
1823         return ret;
1824 }
1825 EXPORT_SYMBOL_GPL(bprintf);
1826
1827 #endif /* CONFIG_BINARY_PRINTF */
1828
1829 /**
1830  * vsscanf - Unformat a buffer into a list of arguments
1831  * @buf:        input buffer
1832  * @fmt:        format of buffer
1833  * @args:       arguments
1834  */
1835 int vsscanf(const char *buf, const char *fmt, va_list args)
1836 {
1837         const char *str = buf;
1838         char *next;
1839         char digit;
1840         int num = 0;
1841         int qualifier, base, field_width;
1842         bool is_sign;
1843
1844         while (*fmt && *str) {
1845                 /* skip any white space in format */
1846                 /* white space in format matchs any amount of
1847                  * white space, including none, in the input.
1848                  */
1849                 if (isspace(*fmt)) {
1850                         fmt = skip_spaces(++fmt);
1851                         str = skip_spaces(str);
1852                 }
1853
1854                 /* anything that is not a conversion must match exactly */
1855                 if (*fmt != '%' && *fmt) {
1856                         if (*fmt++ != *str++)
1857                                 break;
1858                         continue;
1859                 }
1860
1861                 if (!*fmt)
1862                         break;
1863                 ++fmt;
1864
1865                 /* skip this conversion.
1866                  * advance both strings to next white space
1867                  */
1868                 if (*fmt == '*') {
1869                         while (!isspace(*fmt) && *fmt != '%' && *fmt)
1870                                 fmt++;
1871                         while (!isspace(*str) && *str)
1872                                 str++;
1873                         continue;
1874                 }
1875
1876                 /* get field width */
1877                 field_width = -1;
1878                 if (isdigit(*fmt))
1879                         field_width = skip_atoi(&fmt);
1880
1881                 /* get conversion qualifier */
1882                 qualifier = -1;
1883                 if (*fmt == 'h' || TOLOWER(*fmt) == 'l' ||
1884                     TOLOWER(*fmt) == 'z') {
1885                         qualifier = *fmt++;
1886                         if (unlikely(qualifier == *fmt)) {
1887                                 if (qualifier == 'h') {
1888                                         qualifier = 'H';
1889                                         fmt++;
1890                                 } else if (qualifier == 'l') {
1891                                         qualifier = 'L';
1892                                         fmt++;
1893                                 }
1894                         }
1895                 }
1896
1897                 if (!*fmt || !*str)
1898                         break;
1899
1900                 base = 10;
1901                 is_sign = 0;
1902
1903                 switch (*fmt++) {
1904                 case 'c':
1905                 {
1906                         char *s = (char *)va_arg(args, char*);
1907                         if (field_width == -1)
1908                                 field_width = 1;
1909                         do {
1910                                 *s++ = *str++;
1911                         } while (--field_width > 0 && *str);
1912                         num++;
1913                 }
1914                 continue;
1915                 case 's':
1916                 {
1917                         char *s = (char *)va_arg(args, char *);
1918                         if (field_width == -1)
1919                                 field_width = INT_MAX;
1920                         /* first, skip leading white space in buffer */
1921                         str = skip_spaces(str);
1922
1923                         /* now copy until next white space */
1924                         while (*str && !isspace(*str) && field_width--)
1925                                 *s++ = *str++;
1926                         *s = '\0';
1927                         num++;
1928                 }
1929                 continue;
1930                 case 'n':
1931                         /* return number of characters read so far */
1932                 {
1933                         int *i = (int *)va_arg(args, int*);
1934                         *i = str - buf;
1935                 }
1936                 continue;
1937                 case 'o':
1938                         base = 8;
1939                         break;
1940                 case 'x':
1941                 case 'X':
1942                         base = 16;
1943                         break;
1944                 case 'i':
1945                         base = 0;
1946                 case 'd':
1947                         is_sign = 1;
1948                 case 'u':
1949                         break;
1950                 case '%':
1951                         /* looking for '%' in str */
1952                         if (*str++ != '%')
1953                                 return num;
1954                         continue;
1955                 default:
1956                         /* invalid format; stop here */
1957                         return num;
1958                 }
1959
1960                 /* have some sort of integer conversion.
1961                  * first, skip white space in buffer.
1962                  */
1963                 str = skip_spaces(str);
1964
1965                 digit = *str;
1966                 if (is_sign && digit == '-')
1967                         digit = *(str + 1);
1968
1969                 if (!digit
1970                     || (base == 16 && !isxdigit(digit))
1971                     || (base == 10 && !isdigit(digit))
1972                     || (base == 8 && (!isdigit(digit) || digit > '7'))
1973                     || (base == 0 && !isdigit(digit)))
1974                         break;
1975
1976                 switch (qualifier) {
1977                 case 'H':       /* that's 'hh' in format */
1978                         if (is_sign) {
1979                                 signed char *s = (signed char *)va_arg(args, signed char *);
1980                                 *s = (signed char)simple_strtol(str, &next, base);
1981                         } else {
1982                                 unsigned char *s = (unsigned char *)va_arg(args, unsigned char *);
1983                                 *s = (unsigned char)simple_strtoul(str, &next, base);
1984                         }
1985                         break;
1986                 case 'h':
1987                         if (is_sign) {
1988                                 short *s = (short *)va_arg(args, short *);
1989                                 *s = (short)simple_strtol(str, &next, base);
1990                         } else {
1991                                 unsigned short *s = (unsigned short *)va_arg(args, unsigned short *);
1992                                 *s = (unsigned short)simple_strtoul(str, &next, base);
1993                         }
1994                         break;
1995                 case 'l':
1996                         if (is_sign) {
1997                                 long *l = (long *)va_arg(args, long *);
1998                                 *l = simple_strtol(str, &next, base);
1999                         } else {
2000                                 unsigned long *l = (unsigned long *)va_arg(args, unsigned long *);
2001                                 *l = simple_strtoul(str, &next, base);
2002                         }
2003                         break;
2004                 case 'L':
2005                         if (is_sign) {
2006                                 long long *l = (long long *)va_arg(args, long long *);
2007                                 *l = simple_strtoll(str, &next, base);
2008                         } else {
2009                                 unsigned long long *l = (unsigned long long *)va_arg(args, unsigned long long *);
2010                                 *l = simple_strtoull(str, &next, base);
2011                         }
2012                         break;
2013                 case 'Z':
2014                 case 'z':
2015                 {
2016                         size_t *s = (size_t *)va_arg(args, size_t *);
2017                         *s = (size_t)simple_strtoul(str, &next, base);
2018                 }
2019                 break;
2020                 default:
2021                         if (is_sign) {
2022                                 int *i = (int *)va_arg(args, int *);
2023                                 *i = (int)simple_strtol(str, &next, base);
2024                         } else {
2025                                 unsigned int *i = (unsigned int *)va_arg(args, unsigned int*);
2026                                 *i = (unsigned int)simple_strtoul(str, &next, base);
2027                         }
2028                         break;
2029                 }
2030                 num++;
2031
2032                 if (!next)
2033                         break;
2034                 str = next;
2035         }
2036
2037         /*
2038          * Now we've come all the way through so either the input string or the
2039          * format ended. In the former case, there can be a %n at the current
2040          * position in the format that needs to be filled.
2041          */
2042         if (*fmt == '%' && *(fmt + 1) == 'n') {
2043                 int *p = (int *)va_arg(args, int *);
2044                 *p = str - buf;
2045         }
2046
2047         return num;
2048 }
2049 EXPORT_SYMBOL(vsscanf);
2050
2051 /**
2052  * sscanf - Unformat a buffer into a list of arguments
2053  * @buf:        input buffer
2054  * @fmt:        formatting of buffer
2055  * @...:        resulting arguments
2056  */
2057 int sscanf(const char *buf, const char *fmt, ...)
2058 {
2059         va_list args;
2060         int i;
2061
2062         va_start(args, fmt);
2063         i = vsscanf(buf, fmt, args);
2064         va_end(args);
2065
2066         return i;
2067 }
2068 EXPORT_SYMBOL(sscanf);