lib/vsprintf.c

   1 /*
   2  *  linux/lib/vsprintf.c
   3  *
   4  *  Copyright (C) 1991, 1992  Linus Torvalds
   5  */
   6
   7 /* vsprintf.c -- Lars Wirzenius & Linus Torvalds. */
   8 /*
   9  * Wirzenius wrote this portably, Torvalds fucked it up :-)
  10  */
  11
  12 /*
  13  * Fri Jul 13 2001 Crutcher Dunnavant <crutcher+kernel@datastacks.com>
  14  * - changed to provide snprintf and vsnprintf functions
  15  * So Feb  1 16:51:32 CET 2004 Juergen Quade <quade@hsnr.de>
  16  * - scnprintf and vscnprintf
  17  */
  18
  19 #include <stdarg.h>
  20 #include <linux/module.h>
  21 #include <linux/types.h>
  22 #include <linux/string.h>
  23 #include <linux/ctype.h>
  24 #include <linux/kernel.h>
  25 #include <linux/kallsyms.h>
  26 #include <linux/uaccess.h>
  27 #include <linux/ioport.h>
  28 #include <net/addrconf.h>
  29
  30 #include <asm/page.h>           /* for PAGE_SIZE */
  31 #include <asm/div64.h>
  32 #include <asm/sections.h>       /* for dereference_function_descriptor() */
  33
  34 /* Works only for digits and letters, but small and fast */
  35 #define TOLOWER(x) ((x) | 0x20)
  36
  37 static unsigned int simple_guess_base(const char *cp)
  38 {
  39         if (cp[0] == '0') {
  40                 if (TOLOWER(cp[1]) == 'x' && isxdigit(cp[2]))
  41                         return 16;
  42                 else
  43                         return 8;
  44         } else {
  45                 return 10;
  46         }
  47 }
  48
  49 /**
  50  * simple_strtoull - convert a string to an unsigned long long
  51  * @cp: The start of the string
  52  * @endp: A pointer to the end of the parsed string will be placed here
  53  * @base: The number base to use
  54  */
  55 unsigned long long simple_strtoull(const char *cp, char **endp, unsigned int base)
  56 {
  57         unsigned long long result = 0;
  58
  59         if (!base)
  60                 base = simple_guess_base(cp);
  61
  62         if (base == 16 && cp[0] == '0' && TOLOWER(cp[1]) == 'x')
  63                 cp += 2;
  64
  65         while (isxdigit(*cp)) {
  66                 unsigned int value;
  67
  68                 value = isdigit(*cp) ? *cp - '0' : TOLOWER(*cp) - 'a' + 10;
  69                 if (value >= base)
  70                         break;
  71                 result = result * base + value;
  72                 cp++;
  73         }
  74         if (endp)
  75                 *endp = (char *)cp;
  76
  77         return result;
  78 }
  79 EXPORT_SYMBOL(simple_strtoull);
  80
  81 /**
  82  * simple_strtoul - convert a string to an unsigned long
  83  * @cp: The start of the string
  84  * @endp: A pointer to the end of the parsed string will be placed here
  85  * @base: The number base to use
  86  */
  87 unsigned long simple_strtoul(const char *cp, char **endp, unsigned int base)
  88 {
  89         return simple_strtoull(cp, endp, base);
  90 }
  91 EXPORT_SYMBOL(simple_strtoul);
  92
  93 /**
  94  * simple_strtol - convert a string to a signed long
  95  * @cp: The start of the string
  96  * @endp: A pointer to the end of the parsed string will be placed here
  97  * @base: The number base to use
  98  */
  99 long simple_strtol(const char *cp, char **endp, unsigned int base)
 100 {
 101         if (*cp == '-')
 102                 return -simple_strtoul(cp + 1, endp, base);
 103
 104         return simple_strtoul(cp, endp, base);
 105 }
 106 EXPORT_SYMBOL(simple_strtol);
 107
 108 /**
 109  * simple_strtoll - convert a string to a signed long long
 110  * @cp: The start of the string
 111  * @endp: A pointer to the end of the parsed string will be placed here
 112  * @base: The number base to use
 113  */
 114 long long simple_strtoll(const char *cp, char **endp, unsigned int base)
 115 {
 116         if (*cp == '-')
 117                 return -simple_strtoull(cp + 1, endp, base);
 118
 119         return simple_strtoull(cp, endp, base);
 120 }
 121 EXPORT_SYMBOL(simple_strtoll);
 122
 123 static noinline_for_stack
 124 int skip_atoi(const char **s)
 125 {
 126         int i = 0;
 127
 128         while (isdigit(**s))
 129                 i = i*10 + *((*s)++) - '0';
 130
 131         return i;
 132 }
 133
 134 /* Decimal conversion is by far the most typical, and is used
 135  * for /proc and /sys data. This directly impacts e.g. top performance
 136  * with many processes running. We optimize it for speed
 137  * using code from
 138  * http://www.cs.uiowa.edu/~jones/bcd/decimal.html
 139  * (with permission from the author, Douglas W. Jones). */
 140
 141 /* Formats correctly any integer in [0,99999].
 142  * Outputs from one to five digits depending on input.
 143  * On i386 gcc 4.1.2 -O2: ~250 bytes of code. */
 144 static noinline_for_stack
 145 char *put_dec_trunc(char *buf, unsigned q)
 146 {
 147         unsigned d3, d2, d1, d0;
 148         d1 = (q>>4) & 0xf;
 149         d2 = (q>>8) & 0xf;
 150         d3 = (q>>12);
 151
 152         d0 = 6*(d3 + d2 + d1) + (q & 0xf);
 153         q = (d0 * 0xcd) >> 11;
 154         d0 = d0 - 10*q;
 155         *buf++ = d0 + '0'; /* least significant digit */
 156         d1 = q + 9*d3 + 5*d2 + d1;
 157         if (d1 != 0) {
 158                 q = (d1 * 0xcd) >> 11;
 159                 d1 = d1 - 10*q;
 160                 *buf++ = d1 + '0'; /* next digit */
 161
 162                 d2 = q + 2*d2;
 163                 if ((d2 != 0) || (d3 != 0)) {
 164                         q = (d2 * 0xd) >> 7;
 165                         d2 = d2 - 10*q;
 166                         *buf++ = d2 + '0'; /* next digit */
 167
 168                         d3 = q + 4*d3;
 169                         if (d3 != 0) {
 170                                 q = (d3 * 0xcd) >> 11;
 171                                 d3 = d3 - 10*q;
 172                                 *buf++ = d3 + '0';  /* next digit */
 173                                 if (q != 0)
 174                                         *buf++ = q + '0'; /* most sign. digit */
 175                         }
 176                 }
 177         }
 178
 179         return buf;
 180 }
 181 /* Same with if's removed. Always emits five digits */
 182 static noinline_for_stack
 183 char *put_dec_full(char *buf, unsigned q)
 184 {
 185         /* BTW, if q is in [0,9999], 8-bit ints will be enough, */
 186         /* but anyway, gcc produces better code with full-sized ints */
 187         unsigned d3, d2, d1, d0;
 188         d1 = (q>>4) & 0xf;
 189         d2 = (q>>8) & 0xf;
 190         d3 = (q>>12);
 191
 192         /*
 193          * Possible ways to approx. divide by 10
 194          * gcc -O2 replaces multiply with shifts and adds
 195          * (x * 0xcd) >> 11: 11001101 - shorter code than * 0x67 (on i386)
 196          * (x * 0x67) >> 10:  1100111
 197          * (x * 0x34) >> 9:    110100 - same
 198          * (x * 0x1a) >> 8:     11010 - same
 199          * (x * 0x0d) >> 7:      1101 - same, shortest code (on i386)
 200          */
 201         d0 = 6*(d3 + d2 + d1) + (q & 0xf);
 202         q = (d0 * 0xcd) >> 11;
 203         d0 = d0 - 10*q;
 204         *buf++ = d0 + '0';
 205         d1 = q + 9*d3 + 5*d2 + d1;
 206                 q = (d1 * 0xcd) >> 11;
 207                 d1 = d1 - 10*q;
 208                 *buf++ = d1 + '0';
 209
 210                 d2 = q + 2*d2;
 211                         q = (d2 * 0xd) >> 7;
 212                         d2 = d2 - 10*q;
 213                         *buf++ = d2 + '0';
 214
 215                         d3 = q + 4*d3;
 216                                 q = (d3 * 0xcd) >> 11; /* - shorter code */
 217                                 /* q = (d3 * 0x67) >> 10; - would also work */
 218                                 d3 = d3 - 10*q;
 219                                 *buf++ = d3 + '0';
 220                                         *buf++ = q + '0';
 221
 222         return buf;
 223 }
 224 /* No inlining helps gcc to use registers better */
 225 static noinline_for_stack
 226 char *put_dec(char *buf, unsigned long long num)
 227 {
 228         while (1) {
 229                 unsigned rem;
 230                 if (num < 100000)
 231                         return put_dec_trunc(buf, num);
 232                 rem = do_div(num, 100000);
 233                 buf = put_dec_full(buf, rem);
 234         }
 235 }
 236
 237 #define ZEROPAD 1               /* pad with zero */
 238 #define SIGN    2               /* unsigned/signed long */
 239 #define PLUS    4               /* show plus */
 240 #define SPACE   8               /* space if plus */
 241 #define LEFT    16              /* left justified */
 242 #define SMALL   32              /* use lowercase in hex (must be 32 == 0x20) */
 243 #define SPECIAL 64              /* prefix hex with "0x", octal with "0" */
 244
 245 enum format_type {
 246         FORMAT_TYPE_NONE, /* Just a string part */
 247         FORMAT_TYPE_WIDTH,
 248         FORMAT_TYPE_PRECISION,
 249         FORMAT_TYPE_CHAR,
 250         FORMAT_TYPE_STR,
 251         FORMAT_TYPE_PTR,
 252         FORMAT_TYPE_PERCENT_CHAR,
 253         FORMAT_TYPE_INVALID,
 254         FORMAT_TYPE_LONG_LONG,
 255         FORMAT_TYPE_ULONG,
 256         FORMAT_TYPE_LONG,
 257         FORMAT_TYPE_UBYTE,
 258         FORMAT_TYPE_BYTE,
 259         FORMAT_TYPE_USHORT,
 260         FORMAT_TYPE_SHORT,
 261         FORMAT_TYPE_UINT,
 262         FORMAT_TYPE_INT,
 263         FORMAT_TYPE_NRCHARS,
 264         FORMAT_TYPE_SIZE_T,
 265         FORMAT_TYPE_PTRDIFF
 266 };
 267
 268 struct printf_spec {
 269         u8      type;           /* format_type enum */
 270         u8      flags;          /* flags to number() */
 271         u8      base;           /* number base, 8, 10 or 16 only */
 272         u8      qualifier;      /* number qualifier, one of 'hHlLtzZ' */
 273         s16     field_width;    /* width of output field */
 274         s16     precision;      /* # of digits/chars */
 275 };
 276
 277 static noinline_for_stack
 278 char *number(char *buf, char *end, unsigned long long num,
 279              struct printf_spec spec)
 280 {
 281         /* we are called with base 8, 10 or 16, only, thus don't need "G..."  */
 282         static const char digits[16] = "0123456789ABCDEF"; /* "GHIJKLMNOPQRSTUVWXYZ"; */
 283
 284         char tmp[66];
 285         char sign;
 286         char locase;
 287         int need_pfx = ((spec.flags & SPECIAL) && spec.base != 10);
 288         int i;
 289
 290         /* locase = 0 or 0x20. ORing digits or letters with 'locase'
 291          * produces same digits or (maybe lowercased) letters */
 292         locase = (spec.flags & SMALL);
 293         if (spec.flags & LEFT)
 294                 spec.flags &= ~ZEROPAD;
 295         sign = 0;
 296         if (spec.flags & SIGN) {
 297                 if ((signed long long)num < 0) {
 298                         sign = '-';
 299                         num = -(signed long long)num;
 300                         spec.field_width--;
 301                 } else if (spec.flags & PLUS) {
 302                         sign = '+';
 303                         spec.field_width--;
 304                 } else if (spec.flags & SPACE) {
 305                         sign = ' ';
 306                         spec.field_width--;
 307                 }
 308         }
 309         if (need_pfx) {
 310                 spec.field_width--;
 311                 if (spec.base == 16)
 312                         spec.field_width--;
 313         }
 314
 315         /* generate full string in tmp[], in reverse order */
 316         i = 0;
 317         if (num == 0)
 318                 tmp[i++] = '0';
 319         /* Generic code, for any base:
 320         else do {
 321                 tmp[i++] = (digits[do_div(num,base)] | locase);
 322         } while (num != 0);
 323         */
 324         else if (spec.base != 10) { /* 8 or 16 */
 325                 int mask = spec.base - 1;
 326                 int shift = 3;
 327
 328                 if (spec.base == 16)
 329                         shift = 4;
 330                 do {
 331                         tmp[i++] = (digits[((unsigned char)num) & mask] | locase);
 332                         num >>= shift;
 333                 } while (num);
 334         } else { /* base 10 */
 335                 i = put_dec(tmp, num) - tmp;
 336         }
 337
 338         /* printing 100 using %2d gives "100", not "00" */
 339         if (i > spec.precision)
 340                 spec.precision = i;
 341         /* leading space padding */
 342         spec.field_width -= spec.precision;
 343         if (!(spec.flags & (ZEROPAD+LEFT))) {
 344                 while (--spec.field_width >= 0) {
 345                         if (buf < end)
 346                                 *buf = ' ';
 347                         ++buf;
 348                 }
 349         }
 350         /* sign */
 351         if (sign) {
 352                 if (buf < end)
 353                         *buf = sign;
 354                 ++buf;
 355         }
 356         /* "0x" / "0" prefix */
 357         if (need_pfx) {
 358                 if (buf < end)
 359                         *buf = '0';
 360                 ++buf;
 361                 if (spec.base == 16) {
 362                         if (buf < end)
 363                                 *buf = ('X' | locase);
 364                         ++buf;
 365                 }
 366         }
 367         /* zero or space padding */
 368         if (!(spec.flags & LEFT)) {
 369                 char c = (spec.flags & ZEROPAD) ? '0' : ' ';
 370                 while (--spec.field_width >= 0) {
 371                         if (buf < end)
 372                                 *buf = c;
 373                         ++buf;
 374                 }
 375         }
 376         /* hmm even more zero padding? */
 377         while (i <= --spec.precision) {
 378                 if (buf < end)
 379                         *buf = '0';
 380                 ++buf;
 381         }
 382         /* actual digits of result */
 383         while (--i >= 0) {
 384                 if (buf < end)
 385                         *buf = tmp[i];
 386                 ++buf;
 387         }
 388         /* trailing space padding */
 389         while (--spec.field_width >= 0) {
 390                 if (buf < end)
 391                         *buf = ' ';
 392                 ++buf;
 393         }
 394
 395         return buf;
 396 }
 397
 398 static noinline_for_stack
 399 char *string(char *buf, char *end, const char *s, struct printf_spec spec)
 400 {
 401         int len, i;
 402
 403         if ((unsigned long)s < PAGE_SIZE)
 404                 s = "(null)";
 405
 406         len = strnlen(s, spec.precision);
 407
 408         if (!(spec.flags & LEFT)) {
 409                 while (len < spec.field_width--) {
 410                         if (buf < end)
 411                                 *buf = ' ';
 412                         ++buf;
 413                 }
 414         }
 415         for (i = 0; i < len; ++i) {
 416                 if (buf < end)
 417                         *buf = *s;
 418                 ++buf; ++s;
 419         }
 420         while (len < spec.field_width--) {
 421                 if (buf < end)
 422                         *buf = ' ';
 423                 ++buf;
 424         }
 425
 426         return buf;
 427 }
 428
 429 static noinline_for_stack
 430 char *symbol_string(char *buf, char *end, void *ptr,
 431                     struct printf_spec spec, char ext)
 432 {
 433         unsigned long value = (unsigned long) ptr;
 434 #ifdef CONFIG_KALLSYMS
 435         char sym[KSYM_SYMBOL_LEN];
 436         if (ext != 'f' && ext != 's')
 437                 sprint_symbol(sym, value);
 438         else
 439                 kallsyms_lookup(value, NULL, NULL, NULL, sym);
 440
 441         return string(buf, end, sym, spec);
 442 #else
 443         spec.field_width = 2 * sizeof(void *);
 444         spec.flags |= SPECIAL | SMALL | ZEROPAD;
 445         spec.base = 16;
 446
 447         return number(buf, end, value, spec);
 448 #endif
 449 }
 450
 451 static noinline_for_stack
 452 char *resource_string(char *buf, char *end, struct resource *res,
 453                       struct printf_spec spec, const char *fmt)
 454 {
 455 #ifndef IO_RSRC_PRINTK_SIZE
 456 #define IO_RSRC_PRINTK_SIZE     6
 457 #endif
 458
 459 #ifndef MEM_RSRC_PRINTK_SIZE
 460 #define MEM_RSRC_PRINTK_SIZE    10
 461 #endif
 462         static const struct printf_spec io_spec = {
 463                 .base = 16,
 464                 .field_width = IO_RSRC_PRINTK_SIZE,
 465                 .precision = -1,
 466                 .flags = SPECIAL | SMALL | ZEROPAD,
 467         };
 468         static const struct printf_spec mem_spec = {
 469                 .base = 16,
 470                 .field_width = MEM_RSRC_PRINTK_SIZE,
 471                 .precision = -1,
 472                 .flags = SPECIAL | SMALL | ZEROPAD,
 473         };
 474         static const struct printf_spec bus_spec = {
 475                 .base = 16,
 476                 .field_width = 2,
 477                 .precision = -1,
 478                 .flags = SMALL | ZEROPAD,
 479         };
 480         static const struct printf_spec dec_spec = {
 481                 .base = 10,
 482                 .precision = -1,
 483                 .flags = 0,
 484         };
 485         static const struct printf_spec str_spec = {
 486                 .field_width = -1,
 487                 .precision = 10,
 488                 .flags = LEFT,
 489         };
 490         static const struct printf_spec flag_spec = {
 491                 .base = 16,
 492                 .precision = -1,
 493                 .flags = SPECIAL | SMALL,
 494         };
 495
 496         /* 32-bit res (sizeof==4): 10 chars in dec, 10 in hex ("0x" + 8)
 497          * 64-bit res (sizeof==8): 20 chars in dec, 18 in hex ("0x" + 16) */
 498 #define RSRC_BUF_SIZE           ((2 * sizeof(resource_size_t)) + 4)
 499 #define FLAG_BUF_SIZE           (2 * sizeof(res->flags))
 500 #define DECODED_BUF_SIZE        sizeof("[mem - 64bit pref window disabled]")
 501 #define RAW_BUF_SIZE            sizeof("[mem - flags 0x]")
 502         char sym[max(2*RSRC_BUF_SIZE + DECODED_BUF_SIZE,
 503                      2*RSRC_BUF_SIZE + FLAG_BUF_SIZE + RAW_BUF_SIZE)];
 504
 505         char *p = sym, *pend = sym + sizeof(sym);
 506         int decode = (fmt[0] == 'R') ? 1 : 0;
 507         const struct printf_spec *specp;
 508
 509         *p++ = '[';
 510         if (res->flags & IORESOURCE_IO) {
 511                 p = string(p, pend, "io  ", str_spec);
 512                 specp = &io_spec;
 513         } else if (res->flags & IORESOURCE_MEM) {
 514                 p = string(p, pend, "mem ", str_spec);
 515                 specp = &mem_spec;
 516         } else if (res->flags & IORESOURCE_IRQ) {
 517                 p = string(p, pend, "irq ", str_spec);
 518                 specp = &dec_spec;
 519         } else if (res->flags & IORESOURCE_DMA) {
 520                 p = string(p, pend, "dma ", str_spec);
 521                 specp = &dec_spec;
 522         } else if (res->flags & IORESOURCE_BUS) {
 523                 p = string(p, pend, "bus ", str_spec);
 524                 specp = &bus_spec;
 525         } else {
 526                 p = string(p, pend, "??? ", str_spec);
 527                 specp = &mem_spec;
 528                 decode = 0;
 529         }
 530         p = number(p, pend, res->start, *specp);
 531         if (res->start != res->end) {
 532                 *p++ = '-';
 533                 p = number(p, pend, res->end, *specp);
 534         }
 535         if (decode) {
 536                 if (res->flags & IORESOURCE_MEM_64)
 537                         p = string(p, pend, " 64bit", str_spec);
 538                 if (res->flags & IORESOURCE_PREFETCH)
 539                         p = string(p, pend, " pref", str_spec);
 540                 if (res->flags & IORESOURCE_WINDOW)
 541                         p = string(p, pend, " window", str_spec);
 542                 if (res->flags & IORESOURCE_DISABLED)
 543                         p = string(p, pend, " disabled", str_spec);
 544         } else {
 545                 p = string(p, pend, " flags ", str_spec);
 546                 p = number(p, pend, res->flags, flag_spec);
 547         }
 548         *p++ = ']';
 549         *p = '\0';
 550
 551         return string(buf, end, sym, spec);
 552 }
 553
 554 static noinline_for_stack
 555 char *mac_address_string(char *buf, char *end, u8 *addr,
 556                          struct printf_spec spec, const char *fmt)
 557 {
 558         char mac_addr[sizeof("xx:xx:xx:xx:xx:xx")];
 559         char *p = mac_addr;
 560         int i;
 561         char separator;
 562
 563         if (fmt[1] == 'F') {            /* FDDI canonical format */
 564                 separator = '-';
 565         } else {
 566                 separator = ':';
 567         }
 568
 569         for (i = 0; i < 6; i++) {
 570                 p = pack_hex_byte(p, addr[i]);
 571                 if (fmt[0] == 'M' && i != 5)
 572                         *p++ = separator;
 573         }
 574         *p = '\0';
 575
 576         return string(buf, end, mac_addr, spec);
 577 }
 578
 579 static noinline_for_stack
 580 char *ip4_string(char *p, const u8 *addr, const char *fmt)
 581 {
 582         int i;
 583         bool leading_zeros = (fmt[0] == 'i');
 584         int index;
 585         int step;
 586
 587         switch (fmt[2]) {
 588         case 'h':
 589 #ifdef __BIG_ENDIAN
 590                 index = 0;
 591                 step = 1;
 592 #else
 593                 index = 3;
 594                 step = -1;
 595 #endif
 596                 break;
 597         case 'l':
 598                 index = 3;
 599                 step = -1;
 600                 break;
 601         case 'n':
 602         case 'b':
 603         default:
 604                 index = 0;
 605                 step = 1;
 606                 break;
 607         }
 608         for (i = 0; i < 4; i++) {
 609                 char temp[3];   /* hold each IP quad in reverse order */
 610                 int digits = put_dec_trunc(temp, addr[index]) - temp;
 611                 if (leading_zeros) {
 612                         if (digits < 3)
 613                                 *p++ = '0';
 614                         if (digits < 2)
 615                                 *p++ = '0';
 616                 }
 617                 /* reverse the digits in the quad */
 618                 while (digits--)
 619                         *p++ = temp[digits];
 620                 if (i < 3)
 621                         *p++ = '.';
 622                 index += step;
 623         }
 624         *p = '\0';
 625
 626         return p;
 627 }
 628
 629 static noinline_for_stack
 630 char *ip6_compressed_string(char *p, const char *addr)
 631 {
 632         int i, j, range;
 633         unsigned char zerolength[8];
 634         int longest = 1;
 635         int colonpos = -1;
 636         u16 word;
 637         u8 hi, lo;
 638         bool needcolon = false;
 639         bool useIPv4;
 640         struct in6_addr in6;
 641
 642         memcpy(&in6, addr, sizeof(struct in6_addr));
 643
 644         useIPv4 = ipv6_addr_v4mapped(&in6) || ipv6_addr_is_isatap(&in6);
 645
 646         memset(zerolength, 0, sizeof(zerolength));
 647
 648         if (useIPv4)
 649                 range = 6;
 650         else
 651                 range = 8;
 652
 653         /* find position of longest 0 run */
 654         for (i = 0; i < range; i++) {
 655                 for (j = i; j < range; j++) {
 656                         if (in6.s6_addr16[j] != 0)
 657                                 break;
 658                         zerolength[i]++;
 659                 }
 660         }
 661         for (i = 0; i < range; i++) {
 662                 if (zerolength[i] > longest) {
 663                         longest = zerolength[i];
 664                         colonpos = i;
 665                 }
 666         }
 667
 668         /* emit address */
 669         for (i = 0; i < range; i++) {
 670                 if (i == colonpos) {
 671                         if (needcolon || i == 0)
 672                                 *p++ = ':';
 673                         *p++ = ':';
 674                         needcolon = false;
 675                         i += longest - 1;
 676                         continue;
 677                 }
 678                 if (needcolon) {
 679                         *p++ = ':';
 680                         needcolon = false;
 681                 }
 682                 /* hex u16 without leading 0s */
 683                 word = ntohs(in6.s6_addr16[i]);
 684                 hi = word >> 8;
 685                 lo = word & 0xff;
 686                 if (hi) {
 687                         if (hi > 0x0f)
 688                                 p = pack_hex_byte(p, hi);
 689                         else
 690                                 *p++ = hex_asc_lo(hi);
 691                         p = pack_hex_byte(p, lo);
 692                 }
 693                 else if (lo > 0x0f)
 694                         p = pack_hex_byte(p, lo);
 695                 else
 696                         *p++ = hex_asc_lo(lo);
 697                 needcolon = true;
 698         }
 699
 700         if (useIPv4) {
 701                 if (needcolon)
 702                         *p++ = ':';
 703                 p = ip4_string(p, &in6.s6_addr[12], "I4");
 704         }
 705         *p = '\0';
 706
 707         return p;
 708 }
 709
 710 static noinline_for_stack
 711 char *ip6_string(char *p, const char *addr, const char *fmt)
 712 {
 713         int i;
 714
 715         for (i = 0; i < 8; i++) {
 716                 p = pack_hex_byte(p, *addr++);
 717                 p = pack_hex_byte(p, *addr++);
 718                 if (fmt[0] == 'I' && i != 7)
 719                         *p++ = ':';
 720         }
 721         *p = '\0';
 722
 723         return p;
 724 }
 725
 726 static noinline_for_stack
 727 char *ip6_addr_string(char *buf, char *end, const u8 *addr,
 728                       struct printf_spec spec, const char *fmt)
 729 {
 730         char ip6_addr[sizeof("xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255")];
 731
 732         if (fmt[0] == 'I' && fmt[2] == 'c')
 733                 ip6_compressed_string(ip6_addr, addr);
 734         else
 735                 ip6_string(ip6_addr, addr, fmt);
 736
 737         return string(buf, end, ip6_addr, spec);
 738 }
 739
 740 static noinline_for_stack
 741 char *ip4_addr_string(char *buf, char *end, const u8 *addr,
 742                       struct printf_spec spec, const char *fmt)
 743 {
 744         char ip4_addr[sizeof("255.255.255.255")];
 745
 746         ip4_string(ip4_addr, addr, fmt);
 747
 748         return string(buf, end, ip4_addr, spec);
 749 }
 750
 751 static noinline_for_stack
 752 char *uuid_string(char *buf, char *end, const u8 *addr,
 753                   struct printf_spec spec, const char *fmt)
 754 {
 755         char uuid[sizeof("xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx")];
 756         char *p = uuid;
 757         int i;
 758         static const u8 be[16] = {0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15};
 759         static const u8 le[16] = {3,2,1,0,5,4,7,6,8,9,10,11,12,13,14,15};
 760         const u8 *index = be;
 761         bool uc = false;
 762
 763         switch (*(++fmt)) {
 764         case 'L':
 765                 uc = true;              /* fall-through */
 766         case 'l':
 767                 index = le;
 768                 break;
 769         case 'B':
 770                 uc = true;
 771                 break;
 772         }
 773
 774         for (i = 0; i < 16; i++) {
 775                 p = pack_hex_byte(p, addr[index[i]]);
 776                 switch (i) {
 777                 case 3:
 778                 case 5:
 779                 case 7:
 780                 case 9:
 781                         *p++ = '-';
 782                         break;
 783                 }
 784         }
 785
 786         *p = 0;
 787
 788         if (uc) {
 789                 p = uuid;
 790                 do {
 791                         *p = toupper(*p);
 792                 } while (*(++p));
 793         }
 794
 795         return string(buf, end, uuid, spec);
 796 }
 797
 798 int kptr_restrict = 1;
 799
 800 /*
 801  * Show a '%p' thing.  A kernel extension is that the '%p' is followed
 802  * by an extra set of alphanumeric characters that are extended format
 803  * specifiers.
 804  *
 805  * Right now we handle:
 806  *
 807  * - 'F' For symbolic function descriptor pointers with offset
 808  * - 'f' For simple symbolic function names without offset
 809  * - 'S' For symbolic direct pointers with offset
 810  * - 's' For symbolic direct pointers without offset
 811  * - 'R' For decoded struct resource, e.g., [mem 0x0-0x1f 64bit pref]
 812  * - 'r' For raw struct resource, e.g., [mem 0x0-0x1f flags 0x201]
 813  * - 'M' For a 6-byte MAC address, it prints the address in the
 814  *       usual colon-separated hex notation
 815  * - 'm' For a 6-byte MAC address, it prints the hex address without colons
 816  * - 'MF' For a 6-byte MAC FDDI address, it prints the address
 817  *       with a dash-separated hex notation
 818  * - 'I' [46] for IPv4/IPv6 addresses printed in the usual way
 819  *       IPv4 uses dot-separated decimal without leading 0's (1.2.3.4)
 820  *       IPv6 uses colon separated network-order 16 bit hex with leading 0's
 821  * - 'i' [46] for 'raw' IPv4/IPv6 addresses
 822  *       IPv6 omits the colons (01020304...0f)
 823  *       IPv4 uses dot-separated decimal with leading 0's (010.123.045.006)
 824  * - '[Ii]4[hnbl]' IPv4 addresses in host, network, big or little endian order
 825  * - 'I6c' for IPv6 addresses printed as specified by
 826  *       http://tools.ietf.org/html/draft-ietf-6man-text-addr-representation-00
 827  * - 'U' For a 16 byte UUID/GUID, it prints the UUID/GUID in the form
 828  *       "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx"
 829  *       Options for %pU are:
 830  *         b big endian lower case hex (default)
 831  *         B big endian UPPER case hex
 832  *         l little endian lower case hex
 833  *         L little endian UPPER case hex
 834  *           big endian output byte order is:
 835  *             [0][1][2][3]-[4][5]-[6][7]-[8][9]-[10][11][12][13][14][15]
 836  *           little endian output byte order is:
 837  *             [3][2][1][0]-[5][4]-[7][6]-[8][9]-[10][11][12][13][14][15]
 838  * - 'V' For a struct va_format which contains a format string * and va_list *,
 839  *       call vsnprintf(->format, *->va_list).
 840  *       Implements a "recursive vsnprintf".
 841  *       Do not use this feature without some mechanism to verify the
 842  *       correctness of the format string and va_list arguments.
 843  * - 'K' For a kernel pointer that should be hidden from unprivileged users
 844  *
 845  * Note: The difference between 'S' and 'F' is that on ia64 and ppc64
 846  * function pointers are really function descriptors, which contain a
 847  * pointer to the real address.
 848  */
 849 static noinline_for_stack
 850 char *pointer(const char *fmt, char *buf, char *end, void *ptr,
 851               struct printf_spec spec)
 852 {
 853         if (!ptr && *fmt != 'K') {
 854                 /*
 855                  * Print (null) with the same width as a pointer so it makes
 856                  * tabular output look nice.
 857                  */
 858                 if (spec.field_width == -1)
 859                         spec.field_width = 2 * sizeof(void *);
 860                 return string(buf, end, "(null)", spec);
 861         }
 862
 863         switch (*fmt) {
 864         case 'F':
 865         case 'f':
 866                 ptr = dereference_function_descriptor(ptr);
 867                 /* Fallthrough */
 868         case 'S':
 869         case 's':
 870                 return symbol_string(buf, end, ptr, spec, *fmt);
 871         case 'R':
 872         case 'r':
 873                 return resource_string(buf, end, ptr, spec, fmt);
 874         case 'M':                       /* Colon separated: 00:01:02:03:04:05 */
 875         case 'm':                       /* Contiguous: 000102030405 */
 876                                         /* [mM]F (FDDI, bit reversed) */
 877                 return mac_address_string(buf, end, ptr, spec, fmt);
 878         case 'I':                       /* Formatted IP supported
 879                                          * 4:   1.2.3.4
 880                                          * 6:   0001:0203:...:0708
 881                                          * 6c:  1::708 or 1::1.2.3.4
 882                                          */
 883         case 'i':                       /* Contiguous:
 884                                          * 4:   001.002.003.004
 885                                          * 6:   000102...0f
 886                                          */
 887                 switch (fmt[1]) {
 888                 case '6':
 889                         return ip6_addr_string(buf, end, ptr, spec, fmt);
 890                 case '4':
 891                         return ip4_addr_string(buf, end, ptr, spec, fmt);
 892                 }
 893                 break;
 894         case 'U':
 895                 return uuid_string(buf, end, ptr, spec, fmt);
 896         case 'V':
 897                 return buf + vsnprintf(buf, end - buf,
 898                                        ((struct va_format *)ptr)->fmt,
 899                                        *(((struct va_format *)ptr)->va));
 900         case 'K':
 901                 /*
 902                  * %pK cannot be used in IRQ context because its test
 903                  * for CAP_SYSLOG would be meaningless.
 904                  */
 905                 if (in_irq() || in_serving_softirq() || in_nmi()) {
 906                         if (spec.field_width == -1)
 907                                 spec.field_width = 2 * sizeof(void *);
 908                         return string(buf, end, "pK-error", spec);
 909                 }
 910                 if (!((kptr_restrict == 0) ||
 911                       (kptr_restrict == 1 &&
 912                        has_capability_noaudit(current, CAP_SYSLOG))))
 913                         ptr = NULL;
 914                 break;
 915         }
 916         spec.flags |= SMALL;
 917         if (spec.field_width == -1) {
 918                 spec.field_width = 2 * sizeof(void *);
 919                 spec.flags |= ZEROPAD;
 920         }
 921         spec.base = 16;
 922
 923         return number(buf, end, (unsigned long) ptr, spec);
 924 }
 925
 926 /*
 927  * Helper function to decode printf style format.
 928  * Each call decode a token from the format and return the
 929  * number of characters read (or likely the delta where it wants
 930  * to go on the next call).
 931  * The decoded token is returned through the parameters
 932  *
 933  * 'h', 'l', or 'L' for integer fields
 934  * 'z' support added 23/7/1999 S.H.
 935  * 'z' changed to 'Z' --davidm 1/25/99
 936  * 't' added for ptrdiff_t
 937  *
 938  * @fmt: the format string
 939  * @type of the token returned
 940  * @flags: various flags such as +, -, # tokens..
 941  * @field_width: overwritten width
 942  * @base: base of the number (octal, hex, ...)
 943  * @precision: precision of a number
 944  * @qualifier: qualifier of a number (long, size_t, ...)
 945  */
 946 static noinline_for_stack
 947 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' || TOLOWER(*fmt) == 'l' ||
1034             TOLOWER(*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 (TOLOWER(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 with decoded flags
1138  * %pr output the address range in a struct resource with raw flags
1139  * %pM output a 6-byte MAC address with colons
1140  * %pm output a 6-byte MAC address without colons
1141  * %pI4 print an IPv4 address without leading zeros
1142  * %pi4 print an IPv4 address with leading zeros
1143  * %pI6 print an IPv6 address with colons
1144  * %pi6 print an IPv6 address without colons
1145  * %pI6c print an IPv6 address as specified by
1146  *   http://tools.ietf.org/html/draft-ietf-6man-text-addr-representation-00
1147  * %pU[bBlL] print a UUID/GUID in big or little endian using lower or upper
1148  *   case.
1149  * %n is ignored
1150  *
1151  * The return value is the number of characters which would
1152  * be generated for the given input, excluding the trailing
1153  * '\0', as per ISO C99. If you want to have the exact
1154  * number of characters written into @buf as return value
1155  * (not including the trailing '\0'), use vscnprintf(). If the
1156  * return is greater than or equal to @size, the resulting
1157  * string is truncated.
1158  *
1159  * Call this function if you are already dealing with a va_list.
1160  * You probably want snprintf() instead.
1161  */
1162 int vsnprintf(char *buf, size_t size, const char *fmt, va_list args)
1163 {
1164         unsigned long long num;
1165         char *str, *end;
1166         struct printf_spec spec = {0};
1167
1168         /* Reject out-of-range values early.  Large positive sizes are
1169            used for unknown buffer sizes. */
1170         if (WARN_ON_ONCE((int) size < 0))
1171                 return 0;
1172
1173         str = buf;
1174         end = buf + size;
1175
1176         /* Make sure end is always >= buf */
1177         if (end < buf) {
1178                 end = ((void *)-1);
1179                 size = end - buf;
1180         }
1181
1182         while (*fmt) {
1183                 const char *old_fmt = fmt;
1184                 int read = format_decode(fmt, &spec);
1185
1186                 fmt += read;
1187
1188                 switch (spec.type) {
1189                 case FORMAT_TYPE_NONE: {
1190                         int copy = read;
1191                         if (str < end) {
1192                                 if (copy > end - str)
1193                                         copy = end - str;
1194                                 memcpy(str, old_fmt, copy);
1195                         }
1196                         str += read;
1197                         break;
1198                 }
1199
1200                 case FORMAT_TYPE_WIDTH:
1201                         spec.field_width = va_arg(args, int);
1202                         break;
1203
1204                 case FORMAT_TYPE_PRECISION:
1205                         spec.precision = va_arg(args, int);
1206                         break;
1207
1208                 case FORMAT_TYPE_CHAR: {
1209                         char c;
1210
1211                         if (!(spec.flags & LEFT)) {
1212                                 while (--spec.field_width > 0) {
1213                                         if (str < end)
1214                                                 *str = ' ';
1215                                         ++str;
1216
1217                                 }
1218                         }
1219                         c = (unsigned char) va_arg(args, int);
1220                         if (str < end)
1221                                 *str = c;
1222                         ++str;
1223                         while (--spec.field_width > 0) {
1224                                 if (str < end)
1225                                         *str = ' ';
1226                                 ++str;
1227                         }
1228                         break;
1229                 }
1230
1231                 case FORMAT_TYPE_STR:
1232                         str = string(str, end, va_arg(args, char *), spec);
1233                         break;
1234
1235                 case FORMAT_TYPE_PTR:
1236                         str = pointer(fmt+1, str, end, va_arg(args, void *),
1237                                       spec);
1238                         while (isalnum(*fmt))
1239                                 fmt++;
1240                         break;
1241
1242                 case FORMAT_TYPE_PERCENT_CHAR:
1243                         if (str < end)
1244                                 *str = '%';
1245                         ++str;
1246                         break;
1247
1248                 case FORMAT_TYPE_INVALID:
1249                         if (str < end)
1250                                 *str = '%';
1251                         ++str;
1252                         break;
1253
1254                 case FORMAT_TYPE_NRCHARS: {
1255                         u8 qualifier = spec.qualifier;
1256
1257                         if (qualifier == 'l') {
1258                                 long *ip = va_arg(args, long *);
1259                                 *ip = (str - buf);
1260                         } else if (TOLOWER(qualifier) == 'z') {
1261                                 size_t *ip = va_arg(args, size_t *);
1262                                 *ip = (str - buf);
1263                         } else {
1264                                 int *ip = va_arg(args, int *);
1265                                 *ip = (str - buf);
1266                         }
1267                         break;
1268                 }
1269
1270                 default:
1271                         switch (spec.type) {
1272                         case FORMAT_TYPE_LONG_LONG:
1273                                 num = va_arg(args, long long);
1274                                 break;
1275                         case FORMAT_TYPE_ULONG:
1276                                 num = va_arg(args, unsigned long);
1277                                 break;
1278                         case FORMAT_TYPE_LONG:
1279                                 num = va_arg(args, long);
1280                                 break;
1281                         case FORMAT_TYPE_SIZE_T:
1282                                 num = va_arg(args, size_t);
1283                                 break;
1284                         case FORMAT_TYPE_PTRDIFF:
1285                                 num = va_arg(args, ptrdiff_t);
1286                                 break;
1287                         case FORMAT_TYPE_UBYTE:
1288                                 num = (unsigned char) va_arg(args, int);
1289                                 break;
1290                         case FORMAT_TYPE_BYTE:
1291                                 num = (signed char) va_arg(args, int);
1292                                 break;
1293                         case FORMAT_TYPE_USHORT:
1294                                 num = (unsigned short) va_arg(args, int);
1295                                 break;
1296                         case FORMAT_TYPE_SHORT:
1297                                 num = (short) va_arg(args, int);
1298                                 break;
1299                         case FORMAT_TYPE_INT:
1300                                 num = (int) va_arg(args, int);
1301                                 break;
1302                         default:
1303                                 num = va_arg(args, unsigned int);
1304                         }
1305
1306                         str = number(str, end, num, spec);
1307                 }
1308         }
1309
1310         if (size > 0) {
1311                 if (str < end)
1312                         *str = '\0';
1313                 else
1314                         end[-1] = '\0';
1315         }
1316
1317         /* the trailing null byte doesn't count towards the total */
1318         return str-buf;
1319
1320 }
1321 EXPORT_SYMBOL(vsnprintf);
1322
1323 /**
1324  * vscnprintf - Format a string and place it in a buffer
1325  * @buf: The buffer to place the result into
1326  * @size: The size of the buffer, including the trailing null space
1327  * @fmt: The format string to use
1328  * @args: Arguments for the format string
1329  *
1330  * The return value is the number of characters which have been written into
1331  * the @buf not including the trailing '\0'. If @size is == 0 the function
1332  * returns 0.
1333  *
1334  * Call this function if you are already dealing with a va_list.
1335  * You probably want scnprintf() instead.
1336  *
1337  * See the vsnprintf() documentation for format string extensions over C99.
1338  */
1339 int vscnprintf(char *buf, size_t size, const char *fmt, va_list args)
1340 {
1341         int i;
1342
1343         i = vsnprintf(buf, size, fmt, args);
1344
1345         if (likely(i < size))
1346                 return i;
1347         if (size != 0)
1348                 return size - 1;
1349         return 0;
1350 }
1351 EXPORT_SYMBOL(vscnprintf);
1352
1353 /**
1354  * snprintf - Format a string and place it in a buffer
1355  * @buf: The buffer to place the result into
1356  * @size: The size of the buffer, including the trailing null space
1357  * @fmt: The format string to use
1358  * @...: Arguments for the format string
1359  *
1360  * The return value is the number of characters which would be
1361  * generated for the given input, excluding the trailing null,
1362  * as per ISO C99.  If the return is greater than or equal to
1363  * @size, the resulting string is truncated.
1364  *
1365  * See the vsnprintf() documentation for format string extensions over C99.
1366  */
1367 int snprintf(char *buf, size_t size, const char *fmt, ...)
1368 {
1369         va_list args;
1370         int i;
1371
1372         va_start(args, fmt);
1373         i = vsnprintf(buf, size, fmt, args);
1374         va_end(args);
1375
1376         return i;
1377 }
1378 EXPORT_SYMBOL(snprintf);
1379
1380 /**
1381  * scnprintf - Format a string and place it in a buffer
1382  * @buf: The buffer to place the result into
1383  * @size: The size of the buffer, including the trailing null space
1384  * @fmt: The format string to use
1385  * @...: Arguments for the format string
1386  *
1387  * The return value is the number of characters written into @buf not including
1388  * the trailing '\0'. If @size is == 0 the function returns 0.
1389  */
1390
1391 int scnprintf(char *buf, size_t size, const char *fmt, ...)
1392 {
1393         va_list args;
1394         int i;
1395
1396         va_start(args, fmt);
1397         i = vscnprintf(buf, size, fmt, args);
1398         va_end(args);
1399
1400         return i;
1401 }
1402 EXPORT_SYMBOL(scnprintf);
1403
1404 /**
1405  * vsprintf - Format a string and place it in a buffer
1406  * @buf: The buffer to place the result into
1407  * @fmt: The format string to use
1408  * @args: Arguments for the format string
1409  *
1410  * The function returns the number of characters written
1411  * into @buf. Use vsnprintf() or vscnprintf() in order to avoid
1412  * buffer overflows.
1413  *
1414  * Call this function if you are already dealing with a va_list.
1415  * You probably want sprintf() instead.
1416  *
1417  * See the vsnprintf() documentation for format string extensions over C99.
1418  */
1419 int vsprintf(char *buf, const char *fmt, va_list args)
1420 {
1421         return vsnprintf(buf, INT_MAX, fmt, args);
1422 }
1423 EXPORT_SYMBOL(vsprintf);
1424
1425 /**
1426  * sprintf - Format a string and place it in a buffer
1427  * @buf: The buffer to place the result into
1428  * @fmt: The format string to use
1429  * @...: Arguments for the format string
1430  *
1431  * The function returns the number of characters written
1432  * into @buf. Use snprintf() or scnprintf() in order to avoid
1433  * buffer overflows.
1434  *
1435  * See the vsnprintf() documentation for format string extensions over C99.
1436  */
1437 int sprintf(char *buf, const char *fmt, ...)
1438 {
1439         va_list args;
1440         int i;
1441
1442         va_start(args, fmt);
1443         i = vsnprintf(buf, INT_MAX, fmt, args);
1444         va_end(args);
1445
1446         return i;
1447 }
1448 EXPORT_SYMBOL(sprintf);
1449
1450 #ifdef CONFIG_BINARY_PRINTF
1451 /*
1452  * bprintf service:
1453  * vbin_printf() - VA arguments to binary data
1454  * bstr_printf() - Binary data to text string
1455  */
1456
1457 /**
1458  * vbin_printf - Parse a format string and place args' binary value in a buffer
1459  * @bin_buf: The buffer to place args' binary value
1460  * @size: The size of the buffer(by words(32bits), not characters)
1461  * @fmt: The format string to use
1462  * @args: Arguments for the format string
1463  *
1464  * The format follows C99 vsnprintf, except %n is ignored, and its argument
1465  * is skiped.
1466  *
1467  * The return value is the number of words(32bits) which would be generated for
1468  * the given input.
1469  *
1470  * NOTE:
1471  * If the return value is greater than @size, the resulting bin_buf is NOT
1472  * valid for bstr_printf().
1473  */
1474 int vbin_printf(u32 *bin_buf, size_t size, const char *fmt, va_list args)
1475 {
1476         struct printf_spec spec = {0};
1477         char *str, *end;
1478
1479         str = (char *)bin_buf;
1480         end = (char *)(bin_buf + size);
1481
1482 #define save_arg(type)                                                  \
1483 do {                                                                    \
1484         if (sizeof(type) == 8) {                                        \
1485                 unsigned long long value;                               \
1486                 str = PTR_ALIGN(str, sizeof(u32));                      \
1487                 value = va_arg(args, unsigned long long);               \
1488                 if (str + sizeof(type) <= end) {                        \
1489                         *(u32 *)str = *(u32 *)&value;                   \
1490                         *(u32 *)(str + 4) = *((u32 *)&value + 1);       \
1491                 }                                                       \
1492         } else {                                                        \
1493                 unsigned long value;                                    \
1494                 str = PTR_ALIGN(str, sizeof(type));                     \
1495                 value = va_arg(args, int);                              \
1496                 if (str + sizeof(type) <= end)                          \
1497                         *(typeof(type) *)str = (type)value;             \
1498         }                                                               \
1499         str += sizeof(type);                                            \
1500 } while (0)
1501
1502         while (*fmt) {
1503                 int read = format_decode(fmt, &spec);
1504
1505                 fmt += read;
1506
1507                 switch (spec.type) {
1508                 case FORMAT_TYPE_NONE:
1509                 case FORMAT_TYPE_INVALID:
1510                 case FORMAT_TYPE_PERCENT_CHAR:
1511                         break;
1512
1513                 case FORMAT_TYPE_WIDTH:
1514                 case FORMAT_TYPE_PRECISION:
1515                         save_arg(int);
1516                         break;
1517
1518                 case FORMAT_TYPE_CHAR:
1519                         save_arg(char);
1520                         break;
1521
1522                 case FORMAT_TYPE_STR: {
1523                         const char *save_str = va_arg(args, char *);
1524                         size_t len;
1525
1526                         if ((unsigned long)save_str > (unsigned long)-PAGE_SIZE
1527                                         || (unsigned long)save_str < PAGE_SIZE)
1528                                 save_str = "(null)";
1529                         len = strlen(save_str) + 1;
1530                         if (str + len < end)
1531                                 memcpy(str, save_str, len);
1532                         str += len;
1533                         break;
1534                 }
1535
1536                 case FORMAT_TYPE_PTR:
1537                         save_arg(void *);
1538                         /* skip all alphanumeric pointer suffixes */
1539                         while (isalnum(*fmt))
1540                                 fmt++;
1541                         break;
1542
1543                 case FORMAT_TYPE_NRCHARS: {
1544                         /* skip %n 's argument */
1545                         u8 qualifier = spec.qualifier;
1546                         void *skip_arg;
1547                         if (qualifier == 'l')
1548                                 skip_arg = va_arg(args, long *);
1549                         else if (TOLOWER(qualifier) == 'z')
1550                                 skip_arg = va_arg(args, size_t *);
1551                         else
1552                                 skip_arg = va_arg(args, int *);
1553                         break;
1554                 }
1555
1556                 default:
1557                         switch (spec.type) {
1558
1559                         case FORMAT_TYPE_LONG_LONG:
1560                                 save_arg(long long);
1561                                 break;
1562                         case FORMAT_TYPE_ULONG:
1563                         case FORMAT_TYPE_LONG:
1564                                 save_arg(unsigned long);
1565                                 break;
1566                         case FORMAT_TYPE_SIZE_T:
1567                                 save_arg(size_t);
1568                                 break;
1569                         case FORMAT_TYPE_PTRDIFF:
1570                                 save_arg(ptrdiff_t);
1571                                 break;
1572                         case FORMAT_TYPE_UBYTE:
1573                         case FORMAT_TYPE_BYTE:
1574                                 save_arg(char);
1575                                 break;
1576                         case FORMAT_TYPE_USHORT:
1577                         case FORMAT_TYPE_SHORT:
1578                                 save_arg(short);
1579                                 break;
1580                         default:
1581                                 save_arg(int);
1582                         }
1583                 }
1584         }
1585
1586         return (u32 *)(PTR_ALIGN(str, sizeof(u32))) - bin_buf;
1587 #undef save_arg
1588 }
1589 EXPORT_SYMBOL_GPL(vbin_printf);
1590
1591 /**
1592  * bstr_printf - Format a string from binary arguments and place it in a buffer
1593  * @buf: The buffer to place the result into
1594  * @size: The size of the buffer, including the trailing null space
1595  * @fmt: The format string to use
1596  * @bin_buf: Binary arguments for the format string
1597  *
1598  * This function like C99 vsnprintf, but the difference is that vsnprintf gets
1599  * arguments from stack, and bstr_printf gets arguments from @bin_buf which is
1600  * a binary buffer that generated by vbin_printf.
1601  *
1602  * The format follows C99 vsnprintf, but has some extensions:
1603  *  see vsnprintf comment for details.
1604  *
1605  * The return value is the number of characters which would
1606  * be generated for the given input, excluding the trailing
1607  * '\0', as per ISO C99. If you want to have the exact
1608  * number of characters written into @buf as return value
1609  * (not including the trailing '\0'), use vscnprintf(). If the
1610  * return is greater than or equal to @size, the resulting
1611  * string is truncated.
1612  */
1613 int bstr_printf(char *buf, size_t size, const char *fmt, const u32 *bin_buf)
1614 {
1615         struct printf_spec spec = {0};
1616         char *str, *end;
1617         const char *args = (const char *)bin_buf;
1618
1619         if (WARN_ON_ONCE((int) size < 0))
1620                 return 0;
1621
1622         str = buf;
1623         end = buf + size;
1624
1625 #define get_arg(type)                                                   \
1626 ({                                                                      \
1627         typeof(type) value;                                             \
1628         if (sizeof(type) == 8) {                                        \
1629                 args = PTR_ALIGN(args, sizeof(u32));                    \
1630                 *(u32 *)&value = *(u32 *)args;                          \
1631                 *((u32 *)&value + 1) = *(u32 *)(args + 4);              \
1632         } else {                                                        \
1633                 args = PTR_ALIGN(args, sizeof(type));                   \
1634                 value = *(typeof(type) *)args;                          \
1635         }                                                               \
1636         args += sizeof(type);                                           \
1637         value;                                                          \
1638 })
1639
1640         /* Make sure end is always >= buf */
1641         if (end < buf) {
1642                 end = ((void *)-1);
1643                 size = end - buf;
1644         }
1645
1646         while (*fmt) {
1647                 const char *old_fmt = fmt;
1648                 int read = format_decode(fmt, &spec);
1649
1650                 fmt += read;
1651
1652                 switch (spec.type) {
1653                 case FORMAT_TYPE_NONE: {
1654                         int copy = read;
1655                         if (str < end) {
1656                                 if (copy > end - str)
1657                                         copy = end - str;
1658                                 memcpy(str, old_fmt, copy);
1659                         }
1660                         str += read;
1661                         break;
1662                 }
1663
1664                 case FORMAT_TYPE_WIDTH:
1665                         spec.field_width = get_arg(int);
1666                         break;
1667
1668                 case FORMAT_TYPE_PRECISION:
1669                         spec.precision = get_arg(int);
1670                         break;
1671
1672                 case FORMAT_TYPE_CHAR: {
1673                         char c;
1674
1675                         if (!(spec.flags & LEFT)) {
1676                                 while (--spec.field_width > 0) {
1677                                         if (str < end)
1678                                                 *str = ' ';
1679                                         ++str;
1680                                 }
1681                         }
1682                         c = (unsigned char) get_arg(char);
1683                         if (str < end)
1684                                 *str = c;
1685                         ++str;
1686                         while (--spec.field_width > 0) {
1687                                 if (str < end)
1688                                         *str = ' ';
1689                                 ++str;
1690                         }
1691                         break;
1692                 }
1693
1694                 case FORMAT_TYPE_STR: {
1695                         const char *str_arg = args;
1696                         args += strlen(str_arg) + 1;
1697                         str = string(str, end, (char *)str_arg, spec);
1698                         break;
1699                 }
1700
1701                 case FORMAT_TYPE_PTR:
1702                         str = pointer(fmt+1, str, end, get_arg(void *), spec);
1703                         while (isalnum(*fmt))
1704                                 fmt++;
1705                         break;
1706
1707                 case FORMAT_TYPE_PERCENT_CHAR:
1708                 case FORMAT_TYPE_INVALID:
1709                         if (str < end)
1710                                 *str = '%';
1711                         ++str;
1712                         break;
1713
1714                 case FORMAT_TYPE_NRCHARS:
1715                         /* skip */
1716                         break;
1717
1718                 default: {
1719                         unsigned long long num;
1720
1721                         switch (spec.type) {
1722
1723                         case FORMAT_TYPE_LONG_LONG:
1724                                 num = get_arg(long long);
1725                                 break;
1726                         case FORMAT_TYPE_ULONG:
1727                         case FORMAT_TYPE_LONG:
1728                                 num = get_arg(unsigned long);
1729                                 break;
1730                         case FORMAT_TYPE_SIZE_T:
1731                                 num = get_arg(size_t);
1732                                 break;
1733                         case FORMAT_TYPE_PTRDIFF:
1734                                 num = get_arg(ptrdiff_t);
1735                                 break;
1736                         case FORMAT_TYPE_UBYTE:
1737                                 num = get_arg(unsigned char);
1738                                 break;
1739                         case FORMAT_TYPE_BYTE:
1740                                 num = get_arg(signed char);
1741                                 break;
1742                         case FORMAT_TYPE_USHORT:
1743                                 num = get_arg(unsigned short);
1744                                 break;
1745                         case FORMAT_TYPE_SHORT:
1746                                 num = get_arg(short);
1747                                 break;
1748                         case FORMAT_TYPE_UINT:
1749                                 num = get_arg(unsigned int);
1750                                 break;
1751                         default:
1752                                 num = get_arg(int);
1753                         }
1754
1755                         str = number(str, end, num, spec);
1756                 } /* default: */
1757                 } /* switch(spec.type) */
1758         } /* while(*fmt) */
1759
1760         if (size > 0) {
1761                 if (str < end)
1762                         *str = '\0';
1763                 else
1764                         end[-1] = '\0';
1765         }
1766
1767 #undef get_arg
1768
1769         /* the trailing null byte doesn't count towards the total */
1770         return str - buf;
1771 }
1772 EXPORT_SYMBOL_GPL(bstr_printf);
1773
1774 /**
1775  * bprintf - Parse a format string and place args' binary value in a buffer
1776  * @bin_buf: The buffer to place args' binary value
1777  * @size: The size of the buffer(by words(32bits), not characters)
1778  * @fmt: The format string to use
1779  * @...: Arguments for the format string
1780  *
1781  * The function returns the number of words(u32) written
1782  * into @bin_buf.
1783  */
1784 int bprintf(u32 *bin_buf, size_t size, const char *fmt, ...)
1785 {
1786         va_list args;
1787         int ret;
1788
1789         va_start(args, fmt);
1790         ret = vbin_printf(bin_buf, size, fmt, args);
1791         va_end(args);
1792
1793         return ret;
1794 }
1795 EXPORT_SYMBOL_GPL(bprintf);
1796
1797 #endif /* CONFIG_BINARY_PRINTF */
1798
1799 /**
1800  * vsscanf - Unformat a buffer into a list of arguments
1801  * @buf:        input buffer
1802  * @fmt:        format of buffer
1803  * @args:       arguments
1804  */
1805 int vsscanf(const char *buf, const char *fmt, va_list args)
1806 {
1807         const char *str = buf;
1808         char *next;
1809         char digit;
1810         int num = 0;
1811         u8 qualifier;
1812         u8 base;
1813         s16 field_width;
1814         bool is_sign;
1815
1816         while (*fmt && *str) {
1817                 /* skip any white space in format */
1818                 /* white space in format matchs any amount of
1819                  * white space, including none, in the input.
1820                  */
1821                 if (isspace(*fmt)) {
1822                         fmt = skip_spaces(++fmt);
1823                         str = skip_spaces(str);
1824                 }
1825
1826                 /* anything that is not a conversion must match exactly */
1827                 if (*fmt != '%' && *fmt) {
1828                         if (*fmt++ != *str++)
1829                                 break;
1830                         continue;
1831                 }
1832
1833                 if (!*fmt)
1834                         break;
1835                 ++fmt;
1836
1837                 /* skip this conversion.
1838                  * advance both strings to next white space
1839                  */
1840                 if (*fmt == '*') {
1841                         while (!isspace(*fmt) && *fmt != '%' && *fmt)
1842                                 fmt++;
1843                         while (!isspace(*str) && *str)
1844                                 str++;
1845                         continue;
1846                 }
1847
1848                 /* get field width */
1849                 field_width = -1;
1850                 if (isdigit(*fmt))
1851                         field_width = skip_atoi(&fmt);
1852
1853                 /* get conversion qualifier */
1854                 qualifier = -1;
1855                 if (*fmt == 'h' || TOLOWER(*fmt) == 'l' ||
1856                     TOLOWER(*fmt) == 'z') {
1857                         qualifier = *fmt++;
1858                         if (unlikely(qualifier == *fmt)) {
1859                                 if (qualifier == 'h') {
1860                                         qualifier = 'H';
1861                                         fmt++;
1862                                 } else if (qualifier == 'l') {
1863                                         qualifier = 'L';
1864                                         fmt++;
1865                                 }
1866                         }
1867                 }
1868
1869                 if (!*fmt || !*str)
1870                         break;
1871
1872                 base = 10;
1873                 is_sign = 0;
1874
1875                 switch (*fmt++) {
1876                 case 'c':
1877                 {
1878                         char *s = (char *)va_arg(args, char*);
1879                         if (field_width == -1)
1880                                 field_width = 1;
1881                         do {
1882                                 *s++ = *str++;
1883                         } while (--field_width > 0 && *str);
1884                         num++;
1885                 }
1886                 continue;
1887                 case 's':
1888                 {
1889                         char *s = (char *)va_arg(args, char *);
1890                         if (field_width == -1)
1891                                 field_width = SHRT_MAX;
1892                         /* first, skip leading white space in buffer */
1893                         str = skip_spaces(str);
1894
1895                         /* now copy until next white space */
1896                         while (*str && !isspace(*str) && field_width--)
1897                                 *s++ = *str++;
1898                         *s = '\0';
1899                         num++;
1900                 }
1901                 continue;
1902                 case 'n':
1903                         /* return number of characters read so far */
1904                 {
1905                         int *i = (int *)va_arg(args, int*);
1906                         *i = str - buf;
1907                 }
1908                 continue;
1909                 case 'o':
1910                         base = 8;
1911                         break;
1912                 case 'x':
1913                 case 'X':
1914                         base = 16;
1915                         break;
1916                 case 'i':
1917                         base = 0;
1918                 case 'd':
1919                         is_sign = 1;
1920                 case 'u':
1921                         break;
1922                 case '%':
1923                         /* looking for '%' in str */
1924                         if (*str++ != '%')
1925                                 return num;
1926                         continue;
1927                 default:
1928                         /* invalid format; stop here */
1929                         return num;
1930                 }
1931
1932                 /* have some sort of integer conversion.
1933                  * first, skip white space in buffer.
1934                  */
1935                 str = skip_spaces(str);
1936
1937                 digit = *str;
1938                 if (is_sign && digit == '-')
1939                         digit = *(str + 1);
1940
1941                 if (!digit
1942                     || (base == 16 && !isxdigit(digit))
1943                     || (base == 10 && !isdigit(digit))
1944                     || (base == 8 && (!isdigit(digit) || digit > '7'))
1945                     || (base == 0 && !isdigit(digit)))
1946                         break;
1947
1948                 switch (qualifier) {
1949                 case 'H':       /* that's 'hh' in format */
1950                         if (is_sign) {
1951                                 signed char *s = (signed char *)va_arg(args, signed char *);
1952                                 *s = (signed char)simple_strtol(str, &next, base);
1953                         } else {
1954                                 unsigned char *s = (unsigned char *)va_arg(args, unsigned char *);
1955                                 *s = (unsigned char)simple_strtoul(str, &next, base);
1956                         }
1957                         break;
1958                 case 'h':
1959                         if (is_sign) {
1960                                 short *s = (short *)va_arg(args, short *);
1961                                 *s = (short)simple_strtol(str, &next, base);
1962                         } else {
1963                                 unsigned short *s = (unsigned short *)va_arg(args, unsigned short *);
1964                                 *s = (unsigned short)simple_strtoul(str, &next, base);
1965                         }
1966                         break;
1967                 case 'l':
1968                         if (is_sign) {
1969                                 long *l = (long *)va_arg(args, long *);
1970                                 *l = simple_strtol(str, &next, base);
1971                         } else {
1972                                 unsigned long *l = (unsigned long *)va_arg(args, unsigned long *);
1973                                 *l = simple_strtoul(str, &next, base);
1974                         }
1975                         break;
1976                 case 'L':
1977                         if (is_sign) {
1978                                 long long *l = (long long *)va_arg(args, long long *);
1979                                 *l = simple_strtoll(str, &next, base);
1980                         } else {
1981                                 unsigned long long *l = (unsigned long long *)va_arg(args, unsigned long long *);
1982                                 *l = simple_strtoull(str, &next, base);
1983                         }
1984                         break;
1985                 case 'Z':
1986                 case 'z':
1987                 {
1988                         size_t *s = (size_t *)va_arg(args, size_t *);
1989                         *s = (size_t)simple_strtoul(str, &next, base);
1990                 }
1991                 break;
1992                 default:
1993                         if (is_sign) {
1994                                 int *i = (int *)va_arg(args, int *);
1995                                 *i = (int)simple_strtol(str, &next, base);
1996                         } else {
1997                                 unsigned int *i = (unsigned int *)va_arg(args, unsigned int*);
1998                                 *i = (unsigned int)simple_strtoul(str, &next, base);
1999                         }
2000                         break;
2001                 }
2002                 num++;
2003
2004                 if (!next)
2005                         break;
2006                 str = next;
2007         }
2008
2009         /*
2010          * Now we've come all the way through so either the input string or the
2011          * format ended. In the former case, there can be a %n at the current
2012          * position in the format that needs to be filled.
2013          */
2014         if (*fmt == '%' && *(fmt + 1) == 'n') {
2015                 int *p = (int *)va_arg(args, int *);
2016                 *p = str - buf;
2017         }
2018
2019         return num;
2020 }
2021 EXPORT_SYMBOL(vsscanf);
2022
2023 /**
2024  * sscanf - Unformat a buffer into a list of arguments
2025  * @buf:        input buffer
2026  * @fmt:        formatting of buffer
2027  * @...:        resulting arguments
2028  */
2029 int sscanf(const char *buf, const char *fmt, ...)
2030 {
2031         va_list args;
2032         int i;
2033
2034         va_start(args, fmt);
2035         i = vsscanf(buf, fmt, args);
2036         va_end(args);
2037
2038         return i;
2039 }
2040 EXPORT_SYMBOL(sscanf);