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 static unsigned int simple_guess_base(const char *cp)
  35 {
  36         if (cp[0] == '0') {
  37                 if (_tolower(cp[1]) == 'x' && isxdigit(cp[2]))
  38                         return 16;
  39                 else
  40                         return 8;
  41         } else {
  42                 return 10;
  43         }
  44 }
  45
  46 /**
  47  * simple_strtoull - convert a string to an unsigned long long
  48  * @cp: The start of the string
  49  * @endp: A pointer to the end of the parsed string will be placed here
  50  * @base: The number base to use
  51  */
  52 unsigned long long simple_strtoull(const char *cp, char **endp, unsigned int base)
  53 {
  54         unsigned long long result = 0;
  55
  56         if (!base)
  57                 base = simple_guess_base(cp);
  58
  59         if (base == 16 && cp[0] == '0' && _tolower(cp[1]) == 'x')
  60                 cp += 2;
  61
  62         while (isxdigit(*cp)) {
  63                 unsigned int value;
  64
  65                 value = isdigit(*cp) ? *cp - '0' : _tolower(*cp) - 'a' + 10;
  66                 if (value >= base)
  67                         break;
  68                 result = result * base + value;
  69                 cp++;
  70         }
  71         if (endp)
  72                 *endp = (char *)cp;
  73
  74         return result;
  75 }
  76 EXPORT_SYMBOL(simple_strtoull);
  77
  78 /**
  79  * simple_strtoul - convert a string to an unsigned long
  80  * @cp: The start of the string
  81  * @endp: A pointer to the end of the parsed string will be placed here
  82  * @base: The number base to use
  83  */
  84 unsigned long simple_strtoul(const char *cp, char **endp, unsigned int base)
  85 {
  86         return simple_strtoull(cp, endp, base);
  87 }
  88 EXPORT_SYMBOL(simple_strtoul);
  89
  90 /**
  91  * simple_strtol - convert a string to a signed long
  92  * @cp: The start of the string
  93  * @endp: A pointer to the end of the parsed string will be placed here
  94  * @base: The number base to use
  95  */
  96 long simple_strtol(const char *cp, char **endp, unsigned int base)
  97 {
  98         if (*cp == '-')
  99                 return -simple_strtoul(cp + 1, endp, base);
 100
 101         return simple_strtoul(cp, endp, base);
 102 }
 103 EXPORT_SYMBOL(simple_strtol);
 104
 105 /**
 106  * simple_strtoll - convert a string to a signed long long
 107  * @cp: The start of the string
 108  * @endp: A pointer to the end of the parsed string will be placed here
 109  * @base: The number base to use
 110  */
 111 long long simple_strtoll(const char *cp, char **endp, unsigned int base)
 112 {
 113         if (*cp == '-')
 114                 return -simple_strtoull(cp + 1, endp, base);
 115
 116         return simple_strtoull(cp, endp, base);
 117 }
 118 EXPORT_SYMBOL(simple_strtoll);
 119
 120 static noinline_for_stack
 121 int skip_atoi(const char **s)
 122 {
 123         int i = 0;
 124
 125         while (isdigit(**s))
 126                 i = i*10 + *((*s)++) - '0';
 127
 128         return i;
 129 }
 130
 131 /* Decimal conversion is by far the most typical, and is used
 132  * for /proc and /sys data. This directly impacts e.g. top performance
 133  * with many processes running. We optimize it for speed
 134  * using code from
 135  * http://www.cs.uiowa.edu/~jones/bcd/decimal.html
 136  * (with permission from the author, Douglas W. Jones). */
 137
 138 /* Formats correctly any integer in [0,99999].
 139  * Outputs from one to five digits depending on input.
 140  * On i386 gcc 4.1.2 -O2: ~250 bytes of code. */
 141 static noinline_for_stack
 142 char *put_dec_trunc(char *buf, unsigned q)
 143 {
 144         unsigned d3, d2, d1, d0;
 145         d1 = (q>>4) & 0xf;
 146         d2 = (q>>8) & 0xf;
 147         d3 = (q>>12);
 148
 149         d0 = 6*(d3 + d2 + d1) + (q & 0xf);
 150         q = (d0 * 0xcd) >> 11;
 151         d0 = d0 - 10*q;
 152         *buf++ = d0 + '0'; /* least significant digit */
 153         d1 = q + 9*d3 + 5*d2 + d1;
 154         if (d1 != 0) {
 155                 q = (d1 * 0xcd) >> 11;
 156                 d1 = d1 - 10*q;
 157                 *buf++ = d1 + '0'; /* next digit */
 158
 159                 d2 = q + 2*d2;
 160                 if ((d2 != 0) || (d3 != 0)) {
 161                         q = (d2 * 0xd) >> 7;
 162                         d2 = d2 - 10*q;
 163                         *buf++ = d2 + '0'; /* next digit */
 164
 165                         d3 = q + 4*d3;
 166                         if (d3 != 0) {
 167                                 q = (d3 * 0xcd) >> 11;
 168                                 d3 = d3 - 10*q;
 169                                 *buf++ = d3 + '0';  /* next digit */
 170                                 if (q != 0)
 171                                         *buf++ = q + '0'; /* most sign. digit */
 172                         }
 173                 }
 174         }
 175
 176         return buf;
 177 }
 178 /* Same with if's removed. Always emits five digits */
 179 static noinline_for_stack
 180 char *put_dec_full(char *buf, unsigned q)
 181 {
 182         /* BTW, if q is in [0,9999], 8-bit ints will be enough, */
 183         /* but anyway, gcc produces better code with full-sized ints */
 184         unsigned d3, d2, d1, d0;
 185         d1 = (q>>4) & 0xf;
 186         d2 = (q>>8) & 0xf;
 187         d3 = (q>>12);
 188
 189         /*
 190          * Possible ways to approx. divide by 10
 191          * gcc -O2 replaces multiply with shifts and adds
 192          * (x * 0xcd) >> 11: 11001101 - shorter code than * 0x67 (on i386)
 193          * (x * 0x67) >> 10:  1100111
 194          * (x * 0x34) >> 9:    110100 - same
 195          * (x * 0x1a) >> 8:     11010 - same
 196          * (x * 0x0d) >> 7:      1101 - same, shortest code (on i386)
 197          */
 198         d0 = 6*(d3 + d2 + d1) + (q & 0xf);
 199         q = (d0 * 0xcd) >> 11;
 200         d0 = d0 - 10*q;
 201         *buf++ = d0 + '0';
 202         d1 = q + 9*d3 + 5*d2 + d1;
 203                 q = (d1 * 0xcd) >> 11;
 204                 d1 = d1 - 10*q;
 205                 *buf++ = d1 + '0';
 206
 207                 d2 = q + 2*d2;
 208                         q = (d2 * 0xd) >> 7;
 209                         d2 = d2 - 10*q;
 210                         *buf++ = d2 + '0';
 211
 212                         d3 = q + 4*d3;
 213                                 q = (d3 * 0xcd) >> 11; /* - shorter code */
 214                                 /* q = (d3 * 0x67) >> 10; - would also work */
 215                                 d3 = d3 - 10*q;
 216                                 *buf++ = d3 + '0';
 217                                         *buf++ = q + '0';
 218
 219         return buf;
 220 }
 221 /* No inlining helps gcc to use registers better */
 222 static noinline_for_stack
 223 char *put_dec(char *buf, unsigned long long num)
 224 {
 225         while (1) {
 226                 unsigned rem;
 227                 if (num < 100000)
 228                         return put_dec_trunc(buf, num);
 229                 rem = do_div(num, 100000);
 230                 buf = put_dec_full(buf, rem);
 231         }
 232 }
 233
 234 #define ZEROPAD 1               /* pad with zero */
 235 #define SIGN    2               /* unsigned/signed long */
 236 #define PLUS    4               /* show plus */
 237 #define SPACE   8               /* space if plus */
 238 #define LEFT    16              /* left justified */
 239 #define SMALL   32              /* use lowercase in hex (must be 32 == 0x20) */
 240 #define SPECIAL 64              /* prefix hex with "0x", octal with "0" */
 241
 242 enum format_type {
 243         FORMAT_TYPE_NONE, /* Just a string part */
 244         FORMAT_TYPE_WIDTH,
 245         FORMAT_TYPE_PRECISION,
 246         FORMAT_TYPE_CHAR,
 247         FORMAT_TYPE_STR,
 248         FORMAT_TYPE_PTR,
 249         FORMAT_TYPE_PERCENT_CHAR,
 250         FORMAT_TYPE_INVALID,
 251         FORMAT_TYPE_LONG_LONG,
 252         FORMAT_TYPE_ULONG,
 253         FORMAT_TYPE_LONG,
 254         FORMAT_TYPE_UBYTE,
 255         FORMAT_TYPE_BYTE,
 256         FORMAT_TYPE_USHORT,
 257         FORMAT_TYPE_SHORT,
 258         FORMAT_TYPE_UINT,
 259         FORMAT_TYPE_INT,
 260         FORMAT_TYPE_NRCHARS,
 261         FORMAT_TYPE_SIZE_T,
 262         FORMAT_TYPE_PTRDIFF
 263 };
 264
 265 struct printf_spec {
 266         u8      type;           /* format_type enum */
 267         u8      flags;          /* flags to number() */
 268         u8      base;           /* number base, 8, 10 or 16 only */
 269         u8      qualifier;      /* number qualifier, one of 'hHlLtzZ' */
 270         s16     field_width;    /* width of output field */
 271         s16     precision;      /* # of digits/chars */
 272 };
 273
 274 static noinline_for_stack
 275 char *number(char *buf, char *end, unsigned long long num,
 276              struct printf_spec spec)
 277 {
 278         /* we are called with base 8, 10 or 16, only, thus don't need "G..."  */
 279         static const char digits[16] = "0123456789ABCDEF"; /* "GHIJKLMNOPQRSTUVWXYZ"; */
 280
 281         char tmp[66];
 282         char sign;
 283         char locase;
 284         int need_pfx = ((spec.flags & SPECIAL) && spec.base != 10);
 285         int i;
 286
 287         /* locase = 0 or 0x20. ORing digits or letters with 'locase'
 288          * produces same digits or (maybe lowercased) letters */
 289         locase = (spec.flags & SMALL);
 290         if (spec.flags & LEFT)
 291                 spec.flags &= ~ZEROPAD;
 292         sign = 0;
 293         if (spec.flags & SIGN) {
 294                 if ((signed long long)num < 0) {
 295                         sign = '-';
 296                         num = -(signed long long)num;
 297                         spec.field_width--;
 298                 } else if (spec.flags & PLUS) {
 299                         sign = '+';
 300                         spec.field_width--;
 301                 } else if (spec.flags & SPACE) {
 302                         sign = ' ';
 303                         spec.field_width--;
 304                 }
 305         }
 306         if (need_pfx) {
 307                 spec.field_width--;
 308                 if (spec.base == 16)
 309                         spec.field_width--;
 310         }
 311
 312         /* generate full string in tmp[], in reverse order */
 313         i = 0;
 314         if (num == 0)
 315                 tmp[i++] = '0';
 316         /* Generic code, for any base:
 317         else do {
 318                 tmp[i++] = (digits[do_div(num,base)] | locase);
 319         } while (num != 0);
 320         */
 321         else if (spec.base != 10) { /* 8 or 16 */
 322                 int mask = spec.base - 1;
 323                 int shift = 3;
 324
 325                 if (spec.base == 16)
 326                         shift = 4;
 327                 do {
 328                         tmp[i++] = (digits[((unsigned char)num) & mask] | locase);
 329                         num >>= shift;
 330                 } while (num);
 331         } else { /* base 10 */
 332                 i = put_dec(tmp, num) - tmp;
 333         }
 334
 335         /* printing 100 using %2d gives "100", not "00" */
 336         if (i > spec.precision)
 337                 spec.precision = i;
 338         /* leading space padding */
 339         spec.field_width -= spec.precision;
 340         if (!(spec.flags & (ZEROPAD+LEFT))) {
 341                 while (--spec.field_width >= 0) {
 342                         if (buf < end)
 343                                 *buf = ' ';
 344                         ++buf;
 345                 }
 346         }
 347         /* sign */
 348         if (sign) {
 349                 if (buf < end)
 350                         *buf = sign;
 351                 ++buf;
 352         }
 353         /* "0x" / "0" prefix */
 354         if (need_pfx) {
 355                 if (buf < end)
 356                         *buf = '0';
 357                 ++buf;
 358                 if (spec.base == 16) {
 359                         if (buf < end)
 360                                 *buf = ('X' | locase);
 361                         ++buf;
 362                 }
 363         }
 364         /* zero or space padding */
 365         if (!(spec.flags & LEFT)) {
 366                 char c = (spec.flags & ZEROPAD) ? '0' : ' ';
 367                 while (--spec.field_width >= 0) {
 368                         if (buf < end)
 369                                 *buf = c;
 370                         ++buf;
 371                 }
 372         }
 373         /* hmm even more zero padding? */
 374         while (i <= --spec.precision) {
 375                 if (buf < end)
 376                         *buf = '0';
 377                 ++buf;
 378         }
 379         /* actual digits of result */
 380         while (--i >= 0) {
 381                 if (buf < end)
 382                         *buf = tmp[i];
 383                 ++buf;
 384         }
 385         /* trailing space padding */
 386         while (--spec.field_width >= 0) {
 387                 if (buf < end)
 388                         *buf = ' ';
 389                 ++buf;
 390         }
 391
 392         return buf;
 393 }
 394
 395 static noinline_for_stack
 396 char *string(char *buf, char *end, const char *s, struct printf_spec spec)
 397 {
 398         int len, i;
 399
 400         if ((unsigned long)s < PAGE_SIZE)
 401                 s = "(null)";
 402
 403         len = strnlen(s, spec.precision);
 404
 405         if (!(spec.flags & LEFT)) {
 406                 while (len < spec.field_width--) {
 407                         if (buf < end)
 408                                 *buf = ' ';
 409                         ++buf;
 410                 }
 411         }
 412         for (i = 0; i < len; ++i) {
 413                 if (buf < end)
 414                         *buf = *s;
 415                 ++buf; ++s;
 416         }
 417         while (len < spec.field_width--) {
 418                 if (buf < end)
 419                         *buf = ' ';
 420                 ++buf;
 421         }
 422
 423         return buf;
 424 }
 425
 426 static noinline_for_stack
 427 char *symbol_string(char *buf, char *end, void *ptr,
 428                     struct printf_spec spec, char ext)
 429 {
 430         unsigned long value = (unsigned long) ptr;
 431 #ifdef CONFIG_KALLSYMS
 432         char sym[KSYM_SYMBOL_LEN];
 433         if (ext == 'B')
 434                 sprint_backtrace(sym, value);
 435         else if (ext != 'f' && ext != 's')
 436                 sprint_symbol(sym, value);
 437         else
 438                 kallsyms_lookup(value, NULL, NULL, NULL, sym);
 439
 440         return string(buf, end, sym, spec);
 441 #else
 442         spec.field_width = 2 * sizeof(void *);
 443         spec.flags |= SPECIAL | SMALL | ZEROPAD;
 444         spec.base = 16;
 445
 446         return number(buf, end, value, spec);
 447 #endif
 448 }
 449
 450 static noinline_for_stack
 451 char *resource_string(char *buf, char *end, struct resource *res,
 452                       struct printf_spec spec, const char *fmt)
 453 {
 454 #ifndef IO_RSRC_PRINTK_SIZE
 455 #define IO_RSRC_PRINTK_SIZE     6
 456 #endif
 457
 458 #ifndef MEM_RSRC_PRINTK_SIZE
 459 #define MEM_RSRC_PRINTK_SIZE    10
 460 #endif
 461         static const struct printf_spec io_spec = {
 462                 .base = 16,
 463                 .field_width = IO_RSRC_PRINTK_SIZE,
 464                 .precision = -1,
 465                 .flags = SPECIAL | SMALL | ZEROPAD,
 466         };
 467         static const struct printf_spec mem_spec = {
 468                 .base = 16,
 469                 .field_width = MEM_RSRC_PRINTK_SIZE,
 470                 .precision = -1,
 471                 .flags = SPECIAL | SMALL | ZEROPAD,
 472         };
 473         static const struct printf_spec bus_spec = {
 474                 .base = 16,
 475                 .field_width = 2,
 476                 .precision = -1,
 477                 .flags = SMALL | ZEROPAD,
 478         };
 479         static const struct printf_spec dec_spec = {
 480                 .base = 10,
 481                 .precision = -1,
 482                 .flags = 0,
 483         };
 484         static const struct printf_spec str_spec = {
 485                 .field_width = -1,
 486                 .precision = 10,
 487                 .flags = LEFT,
 488         };
 489         static const struct printf_spec flag_spec = {
 490                 .base = 16,
 491                 .precision = -1,
 492                 .flags = SPECIAL | SMALL,
 493         };
 494
 495         /* 32-bit res (sizeof==4): 10 chars in dec, 10 in hex ("0x" + 8)
 496          * 64-bit res (sizeof==8): 20 chars in dec, 18 in hex ("0x" + 16) */
 497 #define RSRC_BUF_SIZE           ((2 * sizeof(resource_size_t)) + 4)
 498 #define FLAG_BUF_SIZE           (2 * sizeof(res->flags))
 499 #define DECODED_BUF_SIZE        sizeof("[mem - 64bit pref window disabled]")
 500 #define RAW_BUF_SIZE            sizeof("[mem - flags 0x]")
 501         char sym[max(2*RSRC_BUF_SIZE + DECODED_BUF_SIZE,
 502                      2*RSRC_BUF_SIZE + FLAG_BUF_SIZE + RAW_BUF_SIZE)];
 503
 504         char *p = sym, *pend = sym + sizeof(sym);
 505         int decode = (fmt[0] == 'R') ? 1 : 0;
 506         const struct printf_spec *specp;
 507
 508         *p++ = '[';
 509         if (res->flags & IORESOURCE_IO) {
 510                 p = string(p, pend, "io  ", str_spec);
 511                 specp = &io_spec;
 512         } else if (res->flags & IORESOURCE_MEM) {
 513                 p = string(p, pend, "mem ", str_spec);
 514                 specp = &mem_spec;
 515         } else if (res->flags & IORESOURCE_IRQ) {
 516                 p = string(p, pend, "irq ", str_spec);
 517                 specp = &dec_spec;
 518         } else if (res->flags & IORESOURCE_DMA) {
 519                 p = string(p, pend, "dma ", str_spec);
 520                 specp = &dec_spec;
 521         } else if (res->flags & IORESOURCE_BUS) {
 522                 p = string(p, pend, "bus ", str_spec);
 523                 specp = &bus_spec;
 524         } else {
 525                 p = string(p, pend, "??? ", str_spec);
 526                 specp = &mem_spec;
 527                 decode = 0;
 528         }
 529         p = number(p, pend, res->start, *specp);
 530         if (res->start != res->end) {
 531                 *p++ = '-';
 532                 p = number(p, pend, res->end, *specp);
 533         }
 534         if (decode) {
 535                 if (res->flags & IORESOURCE_MEM_64)
 536                         p = string(p, pend, " 64bit", str_spec);
 537                 if (res->flags & IORESOURCE_PREFETCH)
 538                         p = string(p, pend, " pref", str_spec);
 539                 if (res->flags & IORESOURCE_WINDOW)
 540                         p = string(p, pend, " window", str_spec);
 541                 if (res->flags & IORESOURCE_DISABLED)
 542                         p = string(p, pend, " disabled", str_spec);
 543         } else {
 544                 p = string(p, pend, " flags ", str_spec);
 545                 p = number(p, pend, res->flags, flag_spec);
 546         }
 547         *p++ = ']';
 548         *p = '\0';
 549
 550         return string(buf, end, sym, spec);
 551 }
 552
 553 static noinline_for_stack
 554 char *mac_address_string(char *buf, char *end, u8 *addr,
 555                          struct printf_spec spec, const char *fmt)
 556 {
 557         char mac_addr[sizeof("xx:xx:xx:xx:xx:xx")];
 558         char *p = mac_addr;
 559         int i;
 560         char separator;
 561
 562         if (fmt[1] == 'F') {            /* FDDI canonical format */
 563                 separator = '-';
 564         } else {
 565                 separator = ':';
 566         }
 567
 568         for (i = 0; i < 6; i++) {
 569                 p = pack_hex_byte(p, addr[i]);
 570                 if (fmt[0] == 'M' && i != 5)
 571                         *p++ = separator;
 572         }
 573         *p = '\0';
 574
 575         return string(buf, end, mac_addr, spec);
 576 }
 577
 578 static noinline_for_stack
 579 char *ip4_string(char *p, const u8 *addr, const char *fmt)
 580 {
 581         int i;
 582         bool leading_zeros = (fmt[0] == 'i');
 583         int index;
 584         int step;
 585
 586         switch (fmt[2]) {
 587         case 'h':
 588 #ifdef __BIG_ENDIAN
 589                 index = 0;
 590                 step = 1;
 591 #else
 592                 index = 3;
 593                 step = -1;
 594 #endif
 595                 break;
 596         case 'l':
 597                 index = 3;
 598                 step = -1;
 599                 break;
 600         case 'n':
 601         case 'b':
 602         default:
 603                 index = 0;
 604                 step = 1;
 605                 break;
 606         }
 607         for (i = 0; i < 4; i++) {
 608                 char temp[3];   /* hold each IP quad in reverse order */
 609                 int digits = put_dec_trunc(temp, addr[index]) - temp;
 610                 if (leading_zeros) {
 611                         if (digits < 3)
 612                                 *p++ = '0';
 613                         if (digits < 2)
 614                                 *p++ = '0';
 615                 }
 616                 /* reverse the digits in the quad */
 617                 while (digits--)
 618                         *p++ = temp[digits];
 619                 if (i < 3)
 620                         *p++ = '.';
 621                 index += step;
 622         }
 623         *p = '\0';
 624
 625         return p;
 626 }
 627
 628 static noinline_for_stack
 629 char *ip6_compressed_string(char *p, const char *addr)
 630 {
 631         int i, j, range;
 632         unsigned char zerolength[8];
 633         int longest = 1;
 634         int colonpos = -1;
 635         u16 word;
 636         u8 hi, lo;
 637         bool needcolon = false;
 638         bool useIPv4;
 639         struct in6_addr in6;
 640
 641         memcpy(&in6, addr, sizeof(struct in6_addr));
 642
 643         useIPv4 = ipv6_addr_v4mapped(&in6) || ipv6_addr_is_isatap(&in6);
 644
 645         memset(zerolength, 0, sizeof(zerolength));
 646
 647         if (useIPv4)
 648                 range = 6;
 649         else
 650                 range = 8;
 651
 652         /* find position of longest 0 run */
 653         for (i = 0; i < range; i++) {
 654                 for (j = i; j < range; j++) {
 655                         if (in6.s6_addr16[j] != 0)
 656                                 break;
 657                         zerolength[i]++;
 658                 }
 659         }
 660         for (i = 0; i < range; i++) {
 661                 if (zerolength[i] > longest) {
 662                         longest = zerolength[i];
 663                         colonpos = i;
 664                 }
 665         }
 666         if (longest == 1)               /* don't compress a single 0 */
 667                 colonpos = -1;
 668
 669         /* emit address */
 670         for (i = 0; i < range; i++) {
 671                 if (i == colonpos) {
 672                         if (needcolon || i == 0)
 673                                 *p++ = ':';
 674                         *p++ = ':';
 675                         needcolon = false;
 676                         i += longest - 1;
 677                         continue;
 678                 }
 679                 if (needcolon) {
 680                         *p++ = ':';
 681                         needcolon = false;
 682                 }
 683                 /* hex u16 without leading 0s */
 684                 word = ntohs(in6.s6_addr16[i]);
 685                 hi = word >> 8;
 686                 lo = word & 0xff;
 687                 if (hi) {
 688                         if (hi > 0x0f)
 689                                 p = pack_hex_byte(p, hi);
 690                         else
 691                                 *p++ = hex_asc_lo(hi);
 692                         p = pack_hex_byte(p, lo);
 693                 }
 694                 else if (lo > 0x0f)
 695                         p = pack_hex_byte(p, lo);
 696                 else
 697                         *p++ = hex_asc_lo(lo);
 698                 needcolon = true;
 699         }
 700
 701         if (useIPv4) {
 702                 if (needcolon)
 703                         *p++ = ':';
 704                 p = ip4_string(p, &in6.s6_addr[12], "I4");
 705         }
 706         *p = '\0';
 707
 708         return p;
 709 }
 710
 711 static noinline_for_stack
 712 char *ip6_string(char *p, const char *addr, const char *fmt)
 713 {
 714         int i;
 715
 716         for (i = 0; i < 8; i++) {
 717                 p = pack_hex_byte(p, *addr++);
 718                 p = pack_hex_byte(p, *addr++);
 719                 if (fmt[0] == 'I' && i != 7)
 720                         *p++ = ':';
 721         }
 722         *p = '\0';
 723
 724         return p;
 725 }
 726
 727 static noinline_for_stack
 728 char *ip6_addr_string(char *buf, char *end, const u8 *addr,
 729                       struct printf_spec spec, const char *fmt)
 730 {
 731         char ip6_addr[sizeof("xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255")];
 732
 733         if (fmt[0] == 'I' && fmt[2] == 'c')
 734                 ip6_compressed_string(ip6_addr, addr);
 735         else
 736                 ip6_string(ip6_addr, addr, fmt);
 737
 738         return string(buf, end, ip6_addr, spec);
 739 }
 740
 741 static noinline_for_stack
 742 char *ip4_addr_string(char *buf, char *end, const u8 *addr,
 743                       struct printf_spec spec, const char *fmt)
 744 {
 745         char ip4_addr[sizeof("255.255.255.255")];
 746
 747         ip4_string(ip4_addr, addr, fmt);
 748
 749         return string(buf, end, ip4_addr, spec);
 750 }
 751
 752 static noinline_for_stack
 753 char *uuid_string(char *buf, char *end, const u8 *addr,
 754                   struct printf_spec spec, const char *fmt)
 755 {
 756         char uuid[sizeof("xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx")];
 757         char *p = uuid;
 758         int i;
 759         static const u8 be[16] = {0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15};
 760         static const u8 le[16] = {3,2,1,0,5,4,7,6,8,9,10,11,12,13,14,15};
 761         const u8 *index = be;
 762         bool uc = false;
 763
 764         switch (*(++fmt)) {
 765         case 'L':
 766                 uc = true;              /* fall-through */
 767         case 'l':
 768                 index = le;
 769                 break;
 770         case 'B':
 771                 uc = true;
 772                 break;
 773         }
 774
 775         for (i = 0; i < 16; i++) {
 776                 p = pack_hex_byte(p, addr[index[i]]);
 777                 switch (i) {
 778                 case 3:
 779                 case 5:
 780                 case 7:
 781                 case 9:
 782                         *p++ = '-';
 783                         break;
 784                 }
 785         }
 786
 787         *p = 0;
 788
 789         if (uc) {
 790                 p = uuid;
 791                 do {
 792                         *p = toupper(*p);
 793                 } while (*(++p));
 794         }
 795
 796         return string(buf, end, uuid, spec);
 797 }
 798
 799 int kptr_restrict __read_mostly;
 800
 801 /*
 802  * Show a '%p' thing.  A kernel extension is that the '%p' is followed
 803  * by an extra set of alphanumeric characters that are extended format
 804  * specifiers.
 805  *
 806  * Right now we handle:
 807  *
 808  * - 'F' For symbolic function descriptor pointers with offset
 809  * - 'f' For simple symbolic function names without offset
 810  * - 'S' For symbolic direct pointers with offset
 811  * - 's' For symbolic direct pointers without offset
 812  * - 'B' For backtraced symbolic direct pointers with offset
 813  * - 'R' For decoded struct resource, e.g., [mem 0x0-0x1f 64bit pref]
 814  * - 'r' For raw struct resource, e.g., [mem 0x0-0x1f flags 0x201]
 815  * - 'M' For a 6-byte MAC address, it prints the address in the
 816  *       usual colon-separated hex notation
 817  * - 'm' For a 6-byte MAC address, it prints the hex address without colons
 818  * - 'MF' For a 6-byte MAC FDDI address, it prints the address
 819  *       with a dash-separated hex notation
 820  * - 'I' [46] for IPv4/IPv6 addresses printed in the usual way
 821  *       IPv4 uses dot-separated decimal without leading 0's (1.2.3.4)
 822  *       IPv6 uses colon separated network-order 16 bit hex with leading 0's
 823  * - 'i' [46] for 'raw' IPv4/IPv6 addresses
 824  *       IPv6 omits the colons (01020304...0f)
 825  *       IPv4 uses dot-separated decimal with leading 0's (010.123.045.006)
 826  * - '[Ii]4[hnbl]' IPv4 addresses in host, network, big or little endian order
 827  * - 'I6c' for IPv6 addresses printed as specified by
 828  *       http://tools.ietf.org/html/rfc5952
 829  * - 'U' For a 16 byte UUID/GUID, it prints the UUID/GUID in the form
 830  *       "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx"
 831  *       Options for %pU are:
 832  *         b big endian lower case hex (default)
 833  *         B big endian UPPER case hex
 834  *         l little endian lower case hex
 835  *         L little endian UPPER case hex
 836  *           big endian output byte order is:
 837  *             [0][1][2][3]-[4][5]-[6][7]-[8][9]-[10][11][12][13][14][15]
 838  *           little endian output byte order is:
 839  *             [3][2][1][0]-[5][4]-[7][6]-[8][9]-[10][11][12][13][14][15]
 840  * - 'V' For a struct va_format which contains a format string * and va_list *,
 841  *       call vsnprintf(->format, *->va_list).
 842  *       Implements a "recursive vsnprintf".
 843  *       Do not use this feature without some mechanism to verify the
 844  *       correctness of the format string and va_list arguments.
 845  * - 'K' For a kernel pointer that should be hidden from unprivileged users
 846  *
 847  * Note: The difference between 'S' and 'F' is that on ia64 and ppc64
 848  * function pointers are really function descriptors, which contain a
 849  * pointer to the real address.
 850  */
 851 static noinline_for_stack
 852 char *pointer(const char *fmt, char *buf, char *end, void *ptr,
 853               struct printf_spec spec)
 854 {
 855         if (!ptr && *fmt != 'K') {
 856                 /*
 857                  * Print (null) with the same width as a pointer so it makes
 858                  * tabular output look nice.
 859                  */
 860                 if (spec.field_width == -1)
 861                         spec.field_width = 2 * sizeof(void *);
 862                 return string(buf, end, "(null)", spec);
 863         }
 864
 865         switch (*fmt) {
 866         case 'F':
 867         case 'f':
 868                 ptr = dereference_function_descriptor(ptr);
 869                 /* Fallthrough */
 870         case 'S':
 871         case 's':
 872         case 'B':
 873                 return symbol_string(buf, end, ptr, spec, *fmt);
 874         case 'R':
 875         case 'r':
 876                 return resource_string(buf, end, ptr, spec, fmt);
 877         case 'M':                       /* Colon separated: 00:01:02:03:04:05 */
 878         case 'm':                       /* Contiguous: 000102030405 */
 879                                         /* [mM]F (FDDI, bit reversed) */
 880                 return mac_address_string(buf, end, ptr, spec, fmt);
 881         case 'I':                       /* Formatted IP supported
 882                                          * 4:   1.2.3.4
 883                                          * 6:   0001:0203:...:0708
 884                                          * 6c:  1::708 or 1::1.2.3.4
 885                                          */
 886         case 'i':                       /* Contiguous:
 887                                          * 4:   001.002.003.004
 888                                          * 6:   000102...0f
 889                                          */
 890                 switch (fmt[1]) {
 891                 case '6':
 892                         return ip6_addr_string(buf, end, ptr, spec, fmt);
 893                 case '4':
 894                         return ip4_addr_string(buf, end, ptr, spec, fmt);
 895                 }
 896                 break;
 897         case 'U':
 898                 return uuid_string(buf, end, ptr, spec, fmt);
 899         case 'V':
 900                 return buf + vsnprintf(buf, end > buf ? end - buf : 0,
 901                                        ((struct va_format *)ptr)->fmt,
 902                                        *(((struct va_format *)ptr)->va));
 903         case 'K':
 904                 /*
 905                  * %pK cannot be used in IRQ context because its test
 906                  * for CAP_SYSLOG would be meaningless.
 907                  */
 908                 if (in_irq() || in_serving_softirq() || in_nmi()) {
 909                         if (spec.field_width == -1)
 910                                 spec.field_width = 2 * sizeof(void *);
 911                         return string(buf, end, "pK-error", spec);
 912                 }
 913                 if (!((kptr_restrict == 0) ||
 914                       (kptr_restrict == 1 &&
 915                        has_capability_noaudit(current, CAP_SYSLOG))))
 916                         ptr = NULL;
 917                 break;
 918         }
 919         spec.flags |= SMALL;
 920         if (spec.field_width == -1) {
 921                 spec.field_width = 2 * sizeof(void *);
 922                 spec.flags |= ZEROPAD;
 923         }
 924         spec.base = 16;
 925
 926         return number(buf, end, (unsigned long) ptr, spec);
 927 }
 928
 929 /*
 930  * Helper function to decode printf style format.
 931  * Each call decode a token from the format and return the
 932  * number of characters read (or likely the delta where it wants
 933  * to go on the next call).
 934  * The decoded token is returned through the parameters
 935  *
 936  * 'h', 'l', or 'L' for integer fields
 937  * 'z' support added 23/7/1999 S.H.
 938  * 'z' changed to 'Z' --davidm 1/25/99
 939  * 't' added for ptrdiff_t
 940  *
 941  * @fmt: the format string
 942  * @type of the token returned
 943  * @flags: various flags such as +, -, # tokens..
 944  * @field_width: overwritten width
 945  * @base: base of the number (octal, hex, ...)
 946  * @precision: precision of a number
 947  * @qualifier: qualifier of a number (long, size_t, ...)
 948  */
 949 static noinline_for_stack
 950 int format_decode(const char *fmt, struct printf_spec *spec)
 951 {
 952         const char *start = fmt;
 953
 954         /* we finished early by reading the field width */
 955         if (spec->type == FORMAT_TYPE_WIDTH) {
 956                 if (spec->field_width < 0) {
 957                         spec->field_width = -spec->field_width;
 958                         spec->flags |= LEFT;
 959                 }
 960                 spec->type = FORMAT_TYPE_NONE;
 961                 goto precision;
 962         }
 963
 964         /* we finished early by reading the precision */
 965         if (spec->type == FORMAT_TYPE_PRECISION) {
 966                 if (spec->precision < 0)
 967                         spec->precision = 0;
 968
 969                 spec->type = FORMAT_TYPE_NONE;
 970                 goto qualifier;
 971         }
 972
 973         /* By default */
 974         spec->type = FORMAT_TYPE_NONE;
 975
 976         for (; *fmt ; ++fmt) {
 977                 if (*fmt == '%')
 978                         break;
 979         }
 980
 981         /* Return the current non-format string */
 982         if (fmt != start || !*fmt)
 983                 return fmt - start;
 984
 985         /* Process flags */
 986         spec->flags = 0;
 987
 988         while (1) { /* this also skips first '%' */
 989                 bool found = true;
 990
 991                 ++fmt;
 992
 993                 switch (*fmt) {
 994                 case '-': spec->flags |= LEFT;    break;
 995                 case '+': spec->flags |= PLUS;    break;
 996                 case ' ': spec->flags |= SPACE;   break;
 997                 case '#': spec->flags |= SPECIAL; break;
 998                 case '0': spec->flags |= ZEROPAD; break;
 999                 default:  found = false;
1000                 }
1001
1002                 if (!found)
1003                         break;
1004         }
1005
1006         /* get field width */
1007         spec->field_width = -1;
1008
1009         if (isdigit(*fmt))
1010                 spec->field_width = skip_atoi(&fmt);
1011         else if (*fmt == '*') {
1012                 /* it's the next argument */
1013                 spec->type = FORMAT_TYPE_WIDTH;
1014                 return ++fmt - start;
1015         }
1016
1017 precision:
1018         /* get the precision */
1019         spec->precision = -1;
1020         if (*fmt == '.') {
1021                 ++fmt;
1022                 if (isdigit(*fmt)) {
1023                         spec->precision = skip_atoi(&fmt);
1024                         if (spec->precision < 0)
1025                                 spec->precision = 0;
1026                 } else if (*fmt == '*') {
1027                         /* it's the next argument */
1028                         spec->type = FORMAT_TYPE_PRECISION;
1029                         return ++fmt - start;
1030                 }
1031         }
1032
1033 qualifier:
1034         /* get the conversion qualifier */
1035         spec->qualifier = -1;
1036         if (*fmt == 'h' || _tolower(*fmt) == 'l' ||
1037             _tolower(*fmt) == 'z' || *fmt == 't') {
1038                 spec->qualifier = *fmt++;
1039                 if (unlikely(spec->qualifier == *fmt)) {
1040                         if (spec->qualifier == 'l') {
1041                                 spec->qualifier = 'L';
1042                                 ++fmt;
1043                         } else if (spec->qualifier == 'h') {
1044                                 spec->qualifier = 'H';
1045                                 ++fmt;
1046                         }
1047                 }
1048         }
1049
1050         /* default base */
1051         spec->base = 10;
1052         switch (*fmt) {
1053         case 'c':
1054                 spec->type = FORMAT_TYPE_CHAR;
1055                 return ++fmt - start;
1056
1057         case 's':
1058                 spec->type = FORMAT_TYPE_STR;
1059                 return ++fmt - start;
1060
1061         case 'p':
1062                 spec->type = FORMAT_TYPE_PTR;
1063                 return fmt - start;
1064                 /* skip alnum */
1065
1066         case 'n':
1067                 spec->type = FORMAT_TYPE_NRCHARS;
1068                 return ++fmt - start;
1069
1070         case '%':
1071                 spec->type = FORMAT_TYPE_PERCENT_CHAR;
1072                 return ++fmt - start;
1073
1074         /* integer number formats - set up the flags and "break" */
1075         case 'o':
1076                 spec->base = 8;
1077                 break;
1078
1079         case 'x':
1080                 spec->flags |= SMALL;
1081
1082         case 'X':
1083                 spec->base = 16;
1084                 break;
1085
1086         case 'd':
1087         case 'i':
1088                 spec->flags |= SIGN;
1089         case 'u':
1090                 break;
1091
1092         default:
1093                 spec->type = FORMAT_TYPE_INVALID;
1094                 return fmt - start;
1095         }
1096
1097         if (spec->qualifier == 'L')
1098                 spec->type = FORMAT_TYPE_LONG_LONG;
1099         else if (spec->qualifier == 'l') {
1100                 if (spec->flags & SIGN)
1101                         spec->type = FORMAT_TYPE_LONG;
1102                 else
1103                         spec->type = FORMAT_TYPE_ULONG;
1104         } else if (_tolower(spec->qualifier) == 'z') {
1105                 spec->type = FORMAT_TYPE_SIZE_T;
1106         } else if (spec->qualifier == 't') {
1107                 spec->type = FORMAT_TYPE_PTRDIFF;
1108         } else if (spec->qualifier == 'H') {
1109                 if (spec->flags & SIGN)
1110                         spec->type = FORMAT_TYPE_BYTE;
1111                 else
1112                         spec->type = FORMAT_TYPE_UBYTE;
1113         } else if (spec->qualifier == 'h') {
1114                 if (spec->flags & SIGN)
1115                         spec->type = FORMAT_TYPE_SHORT;
1116                 else
1117                         spec->type = FORMAT_TYPE_USHORT;
1118         } else {
1119                 if (spec->flags & SIGN)
1120                         spec->type = FORMAT_TYPE_INT;
1121                 else
1122                         spec->type = FORMAT_TYPE_UINT;
1123         }
1124
1125         return ++fmt - start;
1126 }
1127
1128 /**
1129  * vsnprintf - Format a string and place it in a buffer
1130  * @buf: The buffer to place the result into
1131  * @size: The size of the buffer, including the trailing null space
1132  * @fmt: The format string to use
1133  * @args: Arguments for the format string
1134  *
1135  * This function follows C99 vsnprintf, but has some extensions:
1136  * %pS output the name of a text symbol with offset
1137  * %ps output the name of a text symbol without offset
1138  * %pF output the name of a function pointer with its offset
1139  * %pf output the name of a function pointer without its offset
1140  * %pB output the name of a backtrace symbol with its offset
1141  * %pR output the address range in a struct resource with decoded flags
1142  * %pr output the address range in a struct resource with raw flags
1143  * %pM output a 6-byte MAC address with colons
1144  * %pm output a 6-byte MAC address without colons
1145  * %pI4 print an IPv4 address without leading zeros
1146  * %pi4 print an IPv4 address with leading zeros
1147  * %pI6 print an IPv6 address with colons
1148  * %pi6 print an IPv6 address without colons
1149  * %pI6c print an IPv6 address as specified by RFC 5952
1150  * %pU[bBlL] print a UUID/GUID in big or little endian using lower or upper
1151  *   case.
1152  * %n is ignored
1153  *
1154  * The return value is the number of characters which would
1155  * be generated for the given input, excluding the trailing
1156  * '\0', as per ISO C99. If you want to have the exact
1157  * number of characters written into @buf as return value
1158  * (not including the trailing '\0'), use vscnprintf(). If the
1159  * return is greater than or equal to @size, the resulting
1160  * string is truncated.
1161  *
1162  * If you're not already dealing with a va_list consider using snprintf().
1163  */
1164 int vsnprintf(char *buf, size_t size, const char *fmt, va_list args)
1165 {
1166         unsigned long long num;
1167         char *str, *end;
1168         struct printf_spec spec = {0};
1169
1170         /* Reject out-of-range values early.  Large positive sizes are
1171            used for unknown buffer sizes. */
1172         if (WARN_ON_ONCE((int) size < 0))
1173                 return 0;
1174
1175         str = buf;
1176         end = buf + size;
1177
1178         /* Make sure end is always >= buf */
1179         if (end < buf) {
1180                 end = ((void *)-1);
1181                 size = end - buf;
1182         }
1183
1184         while (*fmt) {
1185                 const char *old_fmt = fmt;
1186                 int read = format_decode(fmt, &spec);
1187
1188                 fmt += read;
1189
1190                 switch (spec.type) {
1191                 case FORMAT_TYPE_NONE: {
1192                         int copy = read;
1193                         if (str < end) {
1194                                 if (copy > end - str)
1195                                         copy = end - str;
1196                                 memcpy(str, old_fmt, copy);
1197                         }
1198                         str += read;
1199                         break;
1200                 }
1201
1202                 case FORMAT_TYPE_WIDTH:
1203                         spec.field_width = va_arg(args, int);
1204                         break;
1205
1206                 case FORMAT_TYPE_PRECISION:
1207                         spec.precision = va_arg(args, int);
1208                         break;
1209
1210                 case FORMAT_TYPE_CHAR: {
1211                         char c;
1212
1213                         if (!(spec.flags & LEFT)) {
1214                                 while (--spec.field_width > 0) {
1215                                         if (str < end)
1216                                                 *str = ' ';
1217                                         ++str;
1218
1219                                 }
1220                         }
1221                         c = (unsigned char) va_arg(args, int);
1222                         if (str < end)
1223                                 *str = c;
1224                         ++str;
1225                         while (--spec.field_width > 0) {
1226                                 if (str < end)
1227                                         *str = ' ';
1228                                 ++str;
1229                         }
1230                         break;
1231                 }
1232
1233                 case FORMAT_TYPE_STR:
1234                         str = string(str, end, va_arg(args, char *), spec);
1235                         break;
1236
1237                 case FORMAT_TYPE_PTR:
1238                         str = pointer(fmt+1, str, end, va_arg(args, void *),
1239                                       spec);
1240                         while (isalnum(*fmt))
1241                                 fmt++;
1242                         break;
1243
1244                 case FORMAT_TYPE_PERCENT_CHAR:
1245                         if (str < end)
1246                                 *str = '%';
1247                         ++str;
1248                         break;
1249
1250                 case FORMAT_TYPE_INVALID:
1251                         if (str < end)
1252                                 *str = '%';
1253                         ++str;
1254                         break;
1255
1256                 case FORMAT_TYPE_NRCHARS: {
1257                         u8 qualifier = spec.qualifier;
1258
1259                         if (qualifier == 'l') {
1260                                 long *ip = va_arg(args, long *);
1261                                 *ip = (str - buf);
1262                         } else if (_tolower(qualifier) == 'z') {
1263                                 size_t *ip = va_arg(args, size_t *);
1264                                 *ip = (str - buf);
1265                         } else {
1266                                 int *ip = va_arg(args, int *);
1267                                 *ip = (str - buf);
1268                         }
1269                         break;
1270                 }
1271
1272                 default:
1273                         switch (spec.type) {
1274                         case FORMAT_TYPE_LONG_LONG:
1275                                 num = va_arg(args, long long);
1276                                 break;
1277                         case FORMAT_TYPE_ULONG:
1278                                 num = va_arg(args, unsigned long);
1279                                 break;
1280                         case FORMAT_TYPE_LONG:
1281                                 num = va_arg(args, long);
1282                                 break;
1283                         case FORMAT_TYPE_SIZE_T:
1284                                 num = va_arg(args, size_t);
1285                                 break;
1286                         case FORMAT_TYPE_PTRDIFF:
1287                                 num = va_arg(args, ptrdiff_t);
1288                                 break;
1289                         case FORMAT_TYPE_UBYTE:
1290                                 num = (unsigned char) va_arg(args, int);
1291                                 break;
1292                         case FORMAT_TYPE_BYTE:
1293                                 num = (signed char) va_arg(args, int);
1294                                 break;
1295                         case FORMAT_TYPE_USHORT:
1296                                 num = (unsigned short) va_arg(args, int);
1297                                 break;
1298                         case FORMAT_TYPE_SHORT:
1299                                 num = (short) va_arg(args, int);
1300                                 break;
1301                         case FORMAT_TYPE_INT:
1302                                 num = (int) va_arg(args, int);
1303                                 break;
1304                         default:
1305                                 num = va_arg(args, unsigned int);
1306                         }
1307
1308                         str = number(str, end, num, spec);
1309                 }
1310         }
1311
1312         if (size > 0) {
1313                 if (str < end)
1314                         *str = '\0';
1315                 else
1316                         end[-1] = '\0';
1317         }
1318
1319         /* the trailing null byte doesn't count towards the total */
1320         return str-buf;
1321
1322 }
1323 EXPORT_SYMBOL(vsnprintf);
1324
1325 /**
1326  * vscnprintf - Format a string and place it in a buffer
1327  * @buf: The buffer to place the result into
1328  * @size: The size of the buffer, including the trailing null space
1329  * @fmt: The format string to use
1330  * @args: Arguments for the format string
1331  *
1332  * The return value is the number of characters which have been written into
1333  * the @buf not including the trailing '\0'. If @size is == 0 the function
1334  * returns 0.
1335  *
1336  * If you're not already dealing with a va_list consider using scnprintf().
1337  *
1338  * See the vsnprintf() documentation for format string extensions over C99.
1339  */
1340 int vscnprintf(char *buf, size_t size, const char *fmt, va_list args)
1341 {
1342         int i;
1343
1344         i = vsnprintf(buf, size, fmt, args);
1345
1346         if (likely(i < size))
1347                 return i;
1348         if (size != 0)
1349                 return size - 1;
1350         return 0;
1351 }
1352 EXPORT_SYMBOL(vscnprintf);
1353
1354 /**
1355  * snprintf - Format a string and place it in a buffer
1356  * @buf: The buffer to place the result into
1357  * @size: The size of the buffer, including the trailing null space
1358  * @fmt: The format string to use
1359  * @...: Arguments for the format string
1360  *
1361  * The return value is the number of characters which would be
1362  * generated for the given input, excluding the trailing null,
1363  * as per ISO C99.  If the return is greater than or equal to
1364  * @size, the resulting string is truncated.
1365  *
1366  * See the vsnprintf() documentation for format string extensions over C99.
1367  */
1368 int snprintf(char *buf, size_t size, const char *fmt, ...)
1369 {
1370         va_list args;
1371         int i;
1372
1373         va_start(args, fmt);
1374         i = vsnprintf(buf, size, fmt, args);
1375         va_end(args);
1376
1377         return i;
1378 }
1379 EXPORT_SYMBOL(snprintf);
1380
1381 /**
1382  * scnprintf - Format a string and place it in a buffer
1383  * @buf: The buffer to place the result into
1384  * @size: The size of the buffer, including the trailing null space
1385  * @fmt: The format string to use
1386  * @...: Arguments for the format string
1387  *
1388  * The return value is the number of characters written into @buf not including
1389  * the trailing '\0'. If @size is == 0 the function returns 0.
1390  */
1391
1392 int scnprintf(char *buf, size_t size, const char *fmt, ...)
1393 {
1394         va_list args;
1395         int i;
1396
1397         va_start(args, fmt);
1398         i = vscnprintf(buf, size, fmt, args);
1399         va_end(args);
1400
1401         return i;
1402 }
1403 EXPORT_SYMBOL(scnprintf);
1404
1405 /**
1406  * vsprintf - Format a string and place it in a buffer
1407  * @buf: The buffer to place the result into
1408  * @fmt: The format string to use
1409  * @args: Arguments for the format string
1410  *
1411  * The function returns the number of characters written
1412  * into @buf. Use vsnprintf() or vscnprintf() in order to avoid
1413  * buffer overflows.
1414  *
1415  * If you're not already dealing with a va_list consider using sprintf().
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);