lib/vsprintf.c

   1 /*
   2  *  linux/lib/vsprintf.c
   3  *
   4  *  Copyright (C) 1991, 1992  Linus Torvalds
   5  */
   6
   7 /* vsprintf.c -- Lars Wirzenius & Linus Torvalds. */
   8 /*
   9  * Wirzenius wrote this portably, Torvalds fucked it up :-)
  10  */
  11
  12 /*
  13  * Fri Jul 13 2001 Crutcher Dunnavant <crutcher+kernel@datastacks.com>
  14  * - changed to provide snprintf and vsnprintf functions
  15  * So Feb  1 16:51:32 CET 2004 Juergen Quade <quade@hsnr.de>
  16  * - scnprintf and vscnprintf
  17  */
  18
  19 #include <stdarg.h>
  20 #include <linux/module.h>       /* for KSYM_SYMBOL_LEN */
  21 #include <linux/types.h>
  22 #include <linux/string.h>
  23 #include <linux/ctype.h>
  24 #include <linux/kernel.h>
  25 #include <linux/kallsyms.h>
  26 #include <linux/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 #include "kstrtox.h"
  35
  36 /**
  37  * simple_strtoull - convert a string to an unsigned long long
  38  * @cp: The start of the string
  39  * @endp: A pointer to the end of the parsed string will be placed here
  40  * @base: The number base to use
  41  */
  42 unsigned long long simple_strtoull(const char *cp, char **endp, unsigned int base)
  43 {
  44         unsigned long long result;
  45         unsigned int rv;
  46
  47         cp = _parse_integer_fixup_radix(cp, &base);
  48         rv = _parse_integer(cp, base, &result);
  49         /* FIXME */
  50         cp += (rv & ~KSTRTOX_OVERFLOW);
  51
  52         if (endp)
  53                 *endp = (char *)cp;
  54
  55         return result;
  56 }
  57 EXPORT_SYMBOL(simple_strtoull);
  58
  59 /**
  60  * simple_strtoul - convert a string to an unsigned long
  61  * @cp: The start of the string
  62  * @endp: A pointer to the end of the parsed string will be placed here
  63  * @base: The number base to use
  64  */
  65 unsigned long simple_strtoul(const char *cp, char **endp, unsigned int base)
  66 {
  67         return simple_strtoull(cp, endp, base);
  68 }
  69 EXPORT_SYMBOL(simple_strtoul);
  70
  71 /**
  72  * simple_strtol - convert a string to a signed long
  73  * @cp: The start of the string
  74  * @endp: A pointer to the end of the parsed string will be placed here
  75  * @base: The number base to use
  76  */
  77 long simple_strtol(const char *cp, char **endp, unsigned int base)
  78 {
  79         if (*cp == '-')
  80                 return -simple_strtoul(cp + 1, endp, base);
  81
  82         return simple_strtoul(cp, endp, base);
  83 }
  84 EXPORT_SYMBOL(simple_strtol);
  85
  86 /**
  87  * simple_strtoll - convert a string to a signed long long
  88  * @cp: The start of the string
  89  * @endp: A pointer to the end of the parsed string will be placed here
  90  * @base: The number base to use
  91  */
  92 long long simple_strtoll(const char *cp, char **endp, unsigned int base)
  93 {
  94         if (*cp == '-')
  95                 return -simple_strtoull(cp + 1, endp, base);
  96
  97         return simple_strtoull(cp, endp, base);
  98 }
  99 EXPORT_SYMBOL(simple_strtoll);
 100
 101 static noinline_for_stack
 102 int skip_atoi(const char **s)
 103 {
 104         int i = 0;
 105
 106         while (isdigit(**s))
 107                 i = i*10 + *((*s)++) - '0';
 108
 109         return i;
 110 }
 111
 112 /* Decimal conversion is by far the most typical, and is used
 113  * for /proc and /sys data. This directly impacts e.g. top performance
 114  * with many processes running. We optimize it for speed
 115  * using code from
 116  * http://www.cs.uiowa.edu/~jones/bcd/decimal.html
 117  * (with permission from the author, Douglas W. Jones). */
 118
 119 /* Formats correctly any integer in [0,99999].
 120  * Outputs from one to five digits depending on input.
 121  * On i386 gcc 4.1.2 -O2: ~250 bytes of code. */
 122 static noinline_for_stack
 123 char *put_dec_trunc(char *buf, unsigned q)
 124 {
 125         unsigned d3, d2, d1, d0;
 126         d1 = (q>>4) & 0xf;
 127         d2 = (q>>8) & 0xf;
 128         d3 = (q>>12);
 129
 130         d0 = 6*(d3 + d2 + d1) + (q & 0xf);
 131         q = (d0 * 0xcd) >> 11;
 132         d0 = d0 - 10*q;
 133         *buf++ = d0 + '0'; /* least significant digit */
 134         d1 = q + 9*d3 + 5*d2 + d1;
 135         if (d1 != 0) {
 136                 q = (d1 * 0xcd) >> 11;
 137                 d1 = d1 - 10*q;
 138                 *buf++ = d1 + '0'; /* next digit */
 139
 140                 d2 = q + 2*d2;
 141                 if ((d2 != 0) || (d3 != 0)) {
 142                         q = (d2 * 0xd) >> 7;
 143                         d2 = d2 - 10*q;
 144                         *buf++ = d2 + '0'; /* next digit */
 145
 146                         d3 = q + 4*d3;
 147                         if (d3 != 0) {
 148                                 q = (d3 * 0xcd) >> 11;
 149                                 d3 = d3 - 10*q;
 150                                 *buf++ = d3 + '0';  /* next digit */
 151                                 if (q != 0)
 152                                         *buf++ = q + '0'; /* most sign. digit */
 153                         }
 154                 }
 155         }
 156
 157         return buf;
 158 }
 159 /* Same with if's removed. Always emits five digits */
 160 static noinline_for_stack
 161 char *put_dec_full(char *buf, unsigned q)
 162 {
 163         /* BTW, if q is in [0,9999], 8-bit ints will be enough, */
 164         /* but anyway, gcc produces better code with full-sized ints */
 165         unsigned d3, d2, d1, d0;
 166         d1 = (q>>4) & 0xf;
 167         d2 = (q>>8) & 0xf;
 168         d3 = (q>>12);
 169
 170         /*
 171          * Possible ways to approx. divide by 10
 172          * gcc -O2 replaces multiply with shifts and adds
 173          * (x * 0xcd) >> 11: 11001101 - shorter code than * 0x67 (on i386)
 174          * (x * 0x67) >> 10:  1100111
 175          * (x * 0x34) >> 9:    110100 - same
 176          * (x * 0x1a) >> 8:     11010 - same
 177          * (x * 0x0d) >> 7:      1101 - same, shortest code (on i386)
 178          */
 179         d0 = 6*(d3 + d2 + d1) + (q & 0xf);
 180         q = (d0 * 0xcd) >> 11;
 181         d0 = d0 - 10*q;
 182         *buf++ = d0 + '0';
 183         d1 = q + 9*d3 + 5*d2 + d1;
 184                 q = (d1 * 0xcd) >> 11;
 185                 d1 = d1 - 10*q;
 186                 *buf++ = d1 + '0';
 187
 188                 d2 = q + 2*d2;
 189                         q = (d2 * 0xd) >> 7;
 190                         d2 = d2 - 10*q;
 191                         *buf++ = d2 + '0';
 192
 193                         d3 = q + 4*d3;
 194                                 q = (d3 * 0xcd) >> 11; /* - shorter code */
 195                                 /* q = (d3 * 0x67) >> 10; - would also work */
 196                                 d3 = d3 - 10*q;
 197                                 *buf++ = d3 + '0';
 198                                         *buf++ = q + '0';
 199
 200         return buf;
 201 }
 202 /* No inlining helps gcc to use registers better */
 203 static noinline_for_stack
 204 char *put_dec(char *buf, unsigned long long num)
 205 {
 206         while (1) {
 207                 unsigned rem;
 208                 if (num < 100000)
 209                         return put_dec_trunc(buf, num);
 210                 rem = do_div(num, 100000);
 211                 buf = put_dec_full(buf, rem);
 212         }
 213 }
 214
 215 /*
 216  * Convert passed number to decimal string.
 217  * Returns the length of string.  On buffer overflow, returns 0.
 218  *
 219  * If speed is not important, use snprintf(). It's easy to read the code.
 220  */
 221 int num_to_str(char *buf, int size, unsigned long long num)
 222 {
 223         char tmp[21];           /* Enough for 2^64 in decimal */
 224         int idx, len;
 225
 226         len = put_dec(tmp, num) - tmp;
 227
 228         if (len > size)
 229                 return 0;
 230         for (idx = 0; idx < len; ++idx)
 231                 buf[idx] = tmp[len - idx - 1];
 232         return  len;
 233 }
 234
 235 #define ZEROPAD 1               /* pad with zero */
 236 #define SIGN    2               /* unsigned/signed long */
 237 #define PLUS    4               /* show plus */
 238 #define SPACE   8               /* space if plus */
 239 #define LEFT    16              /* left justified */
 240 #define SMALL   32              /* use lowercase in hex (must be 32 == 0x20) */
 241 #define SPECIAL 64              /* prefix hex with "0x", octal with "0" */
 242
 243 enum format_type {
 244         FORMAT_TYPE_NONE, /* Just a string part */
 245         FORMAT_TYPE_WIDTH,
 246         FORMAT_TYPE_PRECISION,
 247         FORMAT_TYPE_CHAR,
 248         FORMAT_TYPE_STR,
 249         FORMAT_TYPE_PTR,
 250         FORMAT_TYPE_PERCENT_CHAR,
 251         FORMAT_TYPE_INVALID,
 252         FORMAT_TYPE_LONG_LONG,
 253         FORMAT_TYPE_ULONG,
 254         FORMAT_TYPE_LONG,
 255         FORMAT_TYPE_UBYTE,
 256         FORMAT_TYPE_BYTE,
 257         FORMAT_TYPE_USHORT,
 258         FORMAT_TYPE_SHORT,
 259         FORMAT_TYPE_UINT,
 260         FORMAT_TYPE_INT,
 261         FORMAT_TYPE_NRCHARS,
 262         FORMAT_TYPE_SIZE_T,
 263         FORMAT_TYPE_PTRDIFF
 264 };
 265
 266 struct printf_spec {
 267         u8      type;           /* format_type enum */
 268         u8      flags;          /* flags to number() */
 269         u8      base;           /* number base, 8, 10 or 16 only */
 270         u8      qualifier;      /* number qualifier, one of 'hHlLtzZ' */
 271         s16     field_width;    /* width of output field */
 272         s16     precision;      /* # of digits/chars */
 273 };
 274
 275 static noinline_for_stack
 276 char *number(char *buf, char *end, unsigned long long num,
 277              struct printf_spec spec)
 278 {
 279         /* we are called with base 8, 10 or 16, only, thus don't need "G..."  */
 280         static const char digits[16] = "0123456789ABCDEF"; /* "GHIJKLMNOPQRSTUVWXYZ"; */
 281
 282         char tmp[66];
 283         char sign;
 284         char locase;
 285         int need_pfx = ((spec.flags & SPECIAL) && spec.base != 10);
 286         int i;
 287
 288         /* locase = 0 or 0x20. ORing digits or letters with 'locase'
 289          * produces same digits or (maybe lowercased) letters */
 290         locase = (spec.flags & SMALL);
 291         if (spec.flags & LEFT)
 292                 spec.flags &= ~ZEROPAD;
 293         sign = 0;
 294         if (spec.flags & SIGN) {
 295                 if ((signed long long)num < 0) {
 296                         sign = '-';
 297                         num = -(signed long long)num;
 298                         spec.field_width--;
 299                 } else if (spec.flags & PLUS) {
 300                         sign = '+';
 301                         spec.field_width--;
 302                 } else if (spec.flags & SPACE) {
 303                         sign = ' ';
 304                         spec.field_width--;
 305                 }
 306         }
 307         if (need_pfx) {
 308                 spec.field_width--;
 309                 if (spec.base == 16)
 310                         spec.field_width--;
 311         }
 312
 313         /* generate full string in tmp[], in reverse order */
 314         i = 0;
 315         if (num == 0)
 316                 tmp[i++] = '0';
 317         /* Generic code, for any base:
 318         else do {
 319                 tmp[i++] = (digits[do_div(num,base)] | locase);
 320         } while (num != 0);
 321         */
 322         else if (spec.base != 10) { /* 8 or 16 */
 323                 int mask = spec.base - 1;
 324                 int shift = 3;
 325
 326                 if (spec.base == 16)
 327                         shift = 4;
 328                 do {
 329                         tmp[i++] = (digits[((unsigned char)num) & mask] | locase);
 330                         num >>= shift;
 331                 } while (num);
 332         } else { /* base 10 */
 333                 i = put_dec(tmp, num) - tmp;
 334         }
 335
 336         /* printing 100 using %2d gives "100", not "00" */
 337         if (i > spec.precision)
 338                 spec.precision = i;
 339         /* leading space padding */
 340         spec.field_width -= spec.precision;
 341         if (!(spec.flags & (ZEROPAD+LEFT))) {
 342                 while (--spec.field_width >= 0) {
 343                         if (buf < end)
 344                                 *buf = ' ';
 345                         ++buf;
 346                 }
 347         }
 348         /* sign */
 349         if (sign) {
 350                 if (buf < end)
 351                         *buf = sign;
 352                 ++buf;
 353         }
 354         /* "0x" / "0" prefix */
 355         if (need_pfx) {
 356                 if (buf < end)
 357                         *buf = '0';
 358                 ++buf;
 359                 if (spec.base == 16) {
 360                         if (buf < end)
 361                                 *buf = ('X' | locase);
 362                         ++buf;
 363                 }
 364         }
 365         /* zero or space padding */
 366         if (!(spec.flags & LEFT)) {
 367                 char c = (spec.flags & ZEROPAD) ? '0' : ' ';
 368                 while (--spec.field_width >= 0) {
 369                         if (buf < end)
 370                                 *buf = c;
 371                         ++buf;
 372                 }
 373         }
 374         /* hmm even more zero padding? */
 375         while (i <= --spec.precision) {
 376                 if (buf < end)
 377                         *buf = '0';
 378                 ++buf;
 379         }
 380         /* actual digits of result */
 381         while (--i >= 0) {
 382                 if (buf < end)
 383                         *buf = tmp[i];
 384                 ++buf;
 385         }
 386         /* trailing space padding */
 387         while (--spec.field_width >= 0) {
 388                 if (buf < end)
 389                         *buf = ' ';
 390                 ++buf;
 391         }
 392
 393         return buf;
 394 }
 395
 396 static noinline_for_stack
 397 char *string(char *buf, char *end, const char *s, struct printf_spec spec)
 398 {
 399         int len, i;
 400
 401         if ((unsigned long)s < PAGE_SIZE)
 402                 s = "(null)";
 403
 404         len = strnlen(s, spec.precision);
 405
 406         if (!(spec.flags & LEFT)) {
 407                 while (len < spec.field_width--) {
 408                         if (buf < end)
 409                                 *buf = ' ';
 410                         ++buf;
 411                 }
 412         }
 413         for (i = 0; i < len; ++i) {
 414                 if (buf < end)
 415                         *buf = *s;
 416                 ++buf; ++s;
 417         }
 418         while (len < spec.field_width--) {
 419                 if (buf < end)
 420                         *buf = ' ';
 421                 ++buf;
 422         }
 423
 424         return buf;
 425 }
 426
 427 static noinline_for_stack
 428 char *symbol_string(char *buf, char *end, void *ptr,
 429                     struct printf_spec spec, char ext)
 430 {
 431         unsigned long value = (unsigned long) ptr;
 432 #ifdef CONFIG_KALLSYMS
 433         char sym[KSYM_SYMBOL_LEN];
 434         if (ext == 'B')
 435                 sprint_backtrace(sym, value);
 436         else 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 = hex_byte_pack(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         if (longest == 1)               /* don't compress a single 0 */
 668                 colonpos = -1;
 669
 670         /* emit address */
 671         for (i = 0; i < range; i++) {
 672                 if (i == colonpos) {
 673                         if (needcolon || i == 0)
 674                                 *p++ = ':';
 675                         *p++ = ':';
 676                         needcolon = false;
 677                         i += longest - 1;
 678                         continue;
 679                 }
 680                 if (needcolon) {
 681                         *p++ = ':';
 682                         needcolon = false;
 683                 }
 684                 /* hex u16 without leading 0s */
 685                 word = ntohs(in6.s6_addr16[i]);
 686                 hi = word >> 8;
 687                 lo = word & 0xff;
 688                 if (hi) {
 689                         if (hi > 0x0f)
 690                                 p = hex_byte_pack(p, hi);
 691                         else
 692                                 *p++ = hex_asc_lo(hi);
 693                         p = hex_byte_pack(p, lo);
 694                 }
 695                 else if (lo > 0x0f)
 696                         p = hex_byte_pack(p, lo);
 697                 else
 698                         *p++ = hex_asc_lo(lo);
 699                 needcolon = true;
 700         }
 701
 702         if (useIPv4) {
 703                 if (needcolon)
 704                         *p++ = ':';
 705                 p = ip4_string(p, &in6.s6_addr[12], "I4");
 706         }
 707         *p = '\0';
 708
 709         return p;
 710 }
 711
 712 static noinline_for_stack
 713 char *ip6_string(char *p, const char *addr, const char *fmt)
 714 {
 715         int i;
 716
 717         for (i = 0; i < 8; i++) {
 718                 p = hex_byte_pack(p, *addr++);
 719                 p = hex_byte_pack(p, *addr++);
 720                 if (fmt[0] == 'I' && i != 7)
 721                         *p++ = ':';
 722         }
 723         *p = '\0';
 724
 725         return p;
 726 }
 727
 728 static noinline_for_stack
 729 char *ip6_addr_string(char *buf, char *end, const u8 *addr,
 730                       struct printf_spec spec, const char *fmt)
 731 {
 732         char ip6_addr[sizeof("xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255")];
 733
 734         if (fmt[0] == 'I' && fmt[2] == 'c')
 735                 ip6_compressed_string(ip6_addr, addr);
 736         else
 737                 ip6_string(ip6_addr, addr, fmt);
 738
 739         return string(buf, end, ip6_addr, spec);
 740 }
 741
 742 static noinline_for_stack
 743 char *ip4_addr_string(char *buf, char *end, const u8 *addr,
 744                       struct printf_spec spec, const char *fmt)
 745 {
 746         char ip4_addr[sizeof("255.255.255.255")];
 747
 748         ip4_string(ip4_addr, addr, fmt);
 749
 750         return string(buf, end, ip4_addr, spec);
 751 }
 752
 753 static noinline_for_stack
 754 char *uuid_string(char *buf, char *end, const u8 *addr,
 755                   struct printf_spec spec, const char *fmt)
 756 {
 757         char uuid[sizeof("xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx")];
 758         char *p = uuid;
 759         int i;
 760         static const u8 be[16] = {0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15};
 761         static const u8 le[16] = {3,2,1,0,5,4,7,6,8,9,10,11,12,13,14,15};
 762         const u8 *index = be;
 763         bool uc = false;
 764
 765         switch (*(++fmt)) {
 766         case 'L':
 767                 uc = true;              /* fall-through */
 768         case 'l':
 769                 index = le;
 770                 break;
 771         case 'B':
 772                 uc = true;
 773                 break;
 774         }
 775
 776         for (i = 0; i < 16; i++) {
 777                 p = hex_byte_pack(p, addr[index[i]]);
 778                 switch (i) {
 779                 case 3:
 780                 case 5:
 781                 case 7:
 782                 case 9:
 783                         *p++ = '-';
 784                         break;
 785                 }
 786         }
 787
 788         *p = 0;
 789
 790         if (uc) {
 791                 p = uuid;
 792                 do {
 793                         *p = toupper(*p);
 794                 } while (*(++p));
 795         }
 796
 797         return string(buf, end, uuid, spec);
 798 }
 799
 800 static
 801 char *netdev_feature_string(char *buf, char *end, const u8 *addr,
 802                       struct printf_spec spec)
 803 {
 804         spec.flags |= SPECIAL | SMALL | ZEROPAD;
 805         if (spec.field_width == -1)
 806                 spec.field_width = 2 + 2 * sizeof(netdev_features_t);
 807         spec.base = 16;
 808
 809         return number(buf, end, *(const netdev_features_t *)addr, spec);
 810 }
 811
 812 int kptr_restrict __read_mostly;
 813
 814 /*
 815  * Show a '%p' thing.  A kernel extension is that the '%p' is followed
 816  * by an extra set of alphanumeric characters that are extended format
 817  * specifiers.
 818  *
 819  * Right now we handle:
 820  *
 821  * - 'F' For symbolic function descriptor pointers with offset
 822  * - 'f' For simple symbolic function names without offset
 823  * - 'S' For symbolic direct pointers with offset
 824  * - 's' For symbolic direct pointers without offset
 825  * - 'B' For backtraced symbolic direct pointers with offset
 826  * - 'R' For decoded struct resource, e.g., [mem 0x0-0x1f 64bit pref]
 827  * - 'r' For raw struct resource, e.g., [mem 0x0-0x1f flags 0x201]
 828  * - 'M' For a 6-byte MAC address, it prints the address in the
 829  *       usual colon-separated hex notation
 830  * - 'm' For a 6-byte MAC address, it prints the hex address without colons
 831  * - 'MF' For a 6-byte MAC FDDI address, it prints the address
 832  *       with a dash-separated hex notation
 833  * - 'I' [46] for IPv4/IPv6 addresses printed in the usual way
 834  *       IPv4 uses dot-separated decimal without leading 0's (1.2.3.4)
 835  *       IPv6 uses colon separated network-order 16 bit hex with leading 0's
 836  * - 'i' [46] for 'raw' IPv4/IPv6 addresses
 837  *       IPv6 omits the colons (01020304...0f)
 838  *       IPv4 uses dot-separated decimal with leading 0's (010.123.045.006)
 839  * - '[Ii]4[hnbl]' IPv4 addresses in host, network, big or little endian order
 840  * - 'I6c' for IPv6 addresses printed as specified by
 841  *       http://tools.ietf.org/html/rfc5952
 842  * - 'U' For a 16 byte UUID/GUID, it prints the UUID/GUID in the form
 843  *       "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx"
 844  *       Options for %pU are:
 845  *         b big endian lower case hex (default)
 846  *         B big endian UPPER case hex
 847  *         l little endian lower case hex
 848  *         L little endian UPPER case hex
 849  *           big endian output byte order is:
 850  *             [0][1][2][3]-[4][5]-[6][7]-[8][9]-[10][11][12][13][14][15]
 851  *           little endian output byte order is:
 852  *             [3][2][1][0]-[5][4]-[7][6]-[8][9]-[10][11][12][13][14][15]
 853  * - 'V' For a struct va_format which contains a format string * and va_list *,
 854  *       call vsnprintf(->format, *->va_list).
 855  *       Implements a "recursive vsnprintf".
 856  *       Do not use this feature without some mechanism to verify the
 857  *       correctness of the format string and va_list arguments.
 858  * - 'K' For a kernel pointer that should be hidden from unprivileged users
 859  * - 'NF' For a netdev_features_t
 860  *
 861  * Note: The difference between 'S' and 'F' is that on ia64 and ppc64
 862  * function pointers are really function descriptors, which contain a
 863  * pointer to the real address.
 864  */
 865 static noinline_for_stack
 866 char *pointer(const char *fmt, char *buf, char *end, void *ptr,
 867               struct printf_spec spec)
 868 {
 869         if (!ptr && *fmt != 'K') {
 870                 /*
 871                  * Print (null) with the same width as a pointer so it makes
 872                  * tabular output look nice.
 873                  */
 874                 if (spec.field_width == -1)
 875                         spec.field_width = 2 * sizeof(void *);
 876                 return string(buf, end, "(null)", spec);
 877         }
 878
 879         switch (*fmt) {
 880         case 'F':
 881         case 'f':
 882                 ptr = dereference_function_descriptor(ptr);
 883                 /* Fallthrough */
 884         case 'S':
 885         case 's':
 886         case 'B':
 887                 return symbol_string(buf, end, ptr, spec, *fmt);
 888         case 'R':
 889         case 'r':
 890                 return resource_string(buf, end, ptr, spec, fmt);
 891         case 'M':                       /* Colon separated: 00:01:02:03:04:05 */
 892         case 'm':                       /* Contiguous: 000102030405 */
 893                                         /* [mM]F (FDDI, bit reversed) */
 894                 return mac_address_string(buf, end, ptr, spec, fmt);
 895         case 'I':                       /* Formatted IP supported
 896                                          * 4:   1.2.3.4
 897                                          * 6:   0001:0203:...:0708
 898                                          * 6c:  1::708 or 1::1.2.3.4
 899                                          */
 900         case 'i':                       /* Contiguous:
 901                                          * 4:   001.002.003.004
 902                                          * 6:   000102...0f
 903                                          */
 904                 switch (fmt[1]) {
 905                 case '6':
 906                         return ip6_addr_string(buf, end, ptr, spec, fmt);
 907                 case '4':
 908                         return ip4_addr_string(buf, end, ptr, spec, fmt);
 909                 }
 910                 break;
 911         case 'U':
 912                 return uuid_string(buf, end, ptr, spec, fmt);
 913         case 'V':
 914                 {
 915                         va_list va;
 916
 917                         va_copy(va, *((struct va_format *)ptr)->va);
 918                         buf += vsnprintf(buf, end > buf ? end - buf : 0,
 919                                          ((struct va_format *)ptr)->fmt, va);
 920                         va_end(va);
 921                         return buf;
 922                 }
 923         case 'K':
 924                 /*
 925                  * %pK cannot be used in IRQ context because its test
 926                  * for CAP_SYSLOG would be meaningless.
 927                  */
 928                 if (in_irq() || in_serving_softirq() || in_nmi()) {
 929                         if (spec.field_width == -1)
 930                                 spec.field_width = 2 * sizeof(void *);
 931                         return string(buf, end, "pK-error", spec);
 932                 }
 933                 if (!((kptr_restrict == 0) ||
 934                       (kptr_restrict == 1 &&
 935                        has_capability_noaudit(current, CAP_SYSLOG))))
 936                         ptr = NULL;
 937                 break;
 938         case 'N':
 939                 switch (fmt[1]) {
 940                 case 'F':
 941                         return netdev_feature_string(buf, end, ptr, spec);
 942                 }
 943                 break;
 944         }
 945         spec.flags |= SMALL;
 946         if (spec.field_width == -1) {
 947                 spec.field_width = 2 * sizeof(void *);
 948                 spec.flags |= ZEROPAD;
 949         }
 950         spec.base = 16;
 951
 952         return number(buf, end, (unsigned long) ptr, spec);
 953 }
 954
 955 /*
 956  * Helper function to decode printf style format.
 957  * Each call decode a token from the format and return the
 958  * number of characters read (or likely the delta where it wants
 959  * to go on the next call).
 960  * The decoded token is returned through the parameters
 961  *
 962  * 'h', 'l', or 'L' for integer fields
 963  * 'z' support added 23/7/1999 S.H.
 964  * 'z' changed to 'Z' --davidm 1/25/99
 965  * 't' added for ptrdiff_t
 966  *
 967  * @fmt: the format string
 968  * @type of the token returned
 969  * @flags: various flags such as +, -, # tokens..
 970  * @field_width: overwritten width
 971  * @base: base of the number (octal, hex, ...)
 972  * @precision: precision of a number
 973  * @qualifier: qualifier of a number (long, size_t, ...)
 974  */
 975 static noinline_for_stack
 976 int format_decode(const char *fmt, struct printf_spec *spec)
 977 {
 978         const char *start = fmt;
 979
 980         /* we finished early by reading the field width */
 981         if (spec->type == FORMAT_TYPE_WIDTH) {
 982                 if (spec->field_width < 0) {
 983                         spec->field_width = -spec->field_width;
 984                         spec->flags |= LEFT;
 985                 }
 986                 spec->type = FORMAT_TYPE_NONE;
 987                 goto precision;
 988         }
 989
 990         /* we finished early by reading the precision */
 991         if (spec->type == FORMAT_TYPE_PRECISION) {
 992                 if (spec->precision < 0)
 993                         spec->precision = 0;
 994
 995                 spec->type = FORMAT_TYPE_NONE;
 996                 goto qualifier;
 997         }
 998
 999         /* By default */
1000         spec->type = FORMAT_TYPE_NONE;
1001
1002         for (; *fmt ; ++fmt) {
1003                 if (*fmt == '%')
1004                         break;
1005         }
1006
1007         /* Return the current non-format string */
1008         if (fmt != start || !*fmt)
1009                 return fmt - start;
1010
1011         /* Process flags */
1012         spec->flags = 0;
1013
1014         while (1) { /* this also skips first '%' */
1015                 bool found = true;
1016
1017                 ++fmt;
1018
1019                 switch (*fmt) {
1020                 case '-': spec->flags |= LEFT;    break;
1021                 case '+': spec->flags |= PLUS;    break;
1022                 case ' ': spec->flags |= SPACE;   break;
1023                 case '#': spec->flags |= SPECIAL; break;
1024                 case '0': spec->flags |= ZEROPAD; break;
1025                 default:  found = false;
1026                 }
1027
1028                 if (!found)
1029                         break;
1030         }
1031
1032         /* get field width */
1033         spec->field_width = -1;
1034
1035         if (isdigit(*fmt))
1036                 spec->field_width = skip_atoi(&fmt);
1037         else if (*fmt == '*') {
1038                 /* it's the next argument */
1039                 spec->type = FORMAT_TYPE_WIDTH;
1040                 return ++fmt - start;
1041         }
1042
1043 precision:
1044         /* get the precision */
1045         spec->precision = -1;
1046         if (*fmt == '.') {
1047                 ++fmt;
1048                 if (isdigit(*fmt)) {
1049                         spec->precision = skip_atoi(&fmt);
1050                         if (spec->precision < 0)
1051                                 spec->precision = 0;
1052                 } else if (*fmt == '*') {
1053                         /* it's the next argument */
1054                         spec->type = FORMAT_TYPE_PRECISION;
1055                         return ++fmt - start;
1056                 }
1057         }
1058
1059 qualifier:
1060         /* get the conversion qualifier */
1061         spec->qualifier = -1;
1062         if (*fmt == 'h' || _tolower(*fmt) == 'l' ||
1063             _tolower(*fmt) == 'z' || *fmt == 't') {
1064                 spec->qualifier = *fmt++;
1065                 if (unlikely(spec->qualifier == *fmt)) {
1066                         if (spec->qualifier == 'l') {
1067                                 spec->qualifier = 'L';
1068                                 ++fmt;
1069                         } else if (spec->qualifier == 'h') {
1070                                 spec->qualifier = 'H';
1071                                 ++fmt;
1072                         }
1073                 }
1074         }
1075
1076         /* default base */
1077         spec->base = 10;
1078         switch (*fmt) {
1079         case 'c':
1080                 spec->type = FORMAT_TYPE_CHAR;
1081                 return ++fmt - start;
1082
1083         case 's':
1084                 spec->type = FORMAT_TYPE_STR;
1085                 return ++fmt - start;
1086
1087         case 'p':
1088                 spec->type = FORMAT_TYPE_PTR;
1089                 return fmt - start;
1090                 /* skip alnum */
1091
1092         case 'n':
1093                 spec->type = FORMAT_TYPE_NRCHARS;
1094                 return ++fmt - start;
1095
1096         case '%':
1097                 spec->type = FORMAT_TYPE_PERCENT_CHAR;
1098                 return ++fmt - start;
1099
1100         /* integer number formats - set up the flags and "break" */
1101         case 'o':
1102                 spec->base = 8;
1103                 break;
1104
1105         case 'x':
1106                 spec->flags |= SMALL;
1107
1108         case 'X':
1109                 spec->base = 16;
1110                 break;
1111
1112         case 'd':
1113         case 'i':
1114                 spec->flags |= SIGN;
1115         case 'u':
1116                 break;
1117
1118         default:
1119                 spec->type = FORMAT_TYPE_INVALID;
1120                 return fmt - start;
1121         }
1122
1123         if (spec->qualifier == 'L')
1124                 spec->type = FORMAT_TYPE_LONG_LONG;
1125         else if (spec->qualifier == 'l') {
1126                 if (spec->flags & SIGN)
1127                         spec->type = FORMAT_TYPE_LONG;
1128                 else
1129                         spec->type = FORMAT_TYPE_ULONG;
1130         } else if (_tolower(spec->qualifier) == 'z') {
1131                 spec->type = FORMAT_TYPE_SIZE_T;
1132         } else if (spec->qualifier == 't') {
1133                 spec->type = FORMAT_TYPE_PTRDIFF;
1134         } else if (spec->qualifier == 'H') {
1135                 if (spec->flags & SIGN)
1136                         spec->type = FORMAT_TYPE_BYTE;
1137                 else
1138                         spec->type = FORMAT_TYPE_UBYTE;
1139         } else if (spec->qualifier == 'h') {
1140                 if (spec->flags & SIGN)
1141                         spec->type = FORMAT_TYPE_SHORT;
1142                 else
1143                         spec->type = FORMAT_TYPE_USHORT;
1144         } else {
1145                 if (spec->flags & SIGN)
1146                         spec->type = FORMAT_TYPE_INT;
1147                 else
1148                         spec->type = FORMAT_TYPE_UINT;
1149         }
1150
1151         return ++fmt - start;
1152 }
1153
1154 /**
1155  * vsnprintf - Format a string and place it in a buffer
1156  * @buf: The buffer to place the result into
1157  * @size: The size of the buffer, including the trailing null space
1158  * @fmt: The format string to use
1159  * @args: Arguments for the format string
1160  *
1161  * This function follows C99 vsnprintf, but has some extensions:
1162  * %pS output the name of a text symbol with offset
1163  * %ps output the name of a text symbol without offset
1164  * %pF output the name of a function pointer with its offset
1165  * %pf output the name of a function pointer without its offset
1166  * %pB output the name of a backtrace symbol with its offset
1167  * %pR output the address range in a struct resource with decoded flags
1168  * %pr output the address range in a struct resource with raw flags
1169  * %pM output a 6-byte MAC address with colons
1170  * %pm output a 6-byte MAC address without colons
1171  * %pI4 print an IPv4 address without leading zeros
1172  * %pi4 print an IPv4 address with leading zeros
1173  * %pI6 print an IPv6 address with colons
1174  * %pi6 print an IPv6 address without colons
1175  * %pI6c print an IPv6 address as specified by RFC 5952
1176  * %pU[bBlL] print a UUID/GUID in big or little endian using lower or upper
1177  *   case.
1178  * %n is ignored
1179  *
1180  * The return value is the number of characters which would
1181  * be generated for the given input, excluding the trailing
1182  * '\0', as per ISO C99. If you want to have the exact
1183  * number of characters written into @buf as return value
1184  * (not including the trailing '\0'), use vscnprintf(). If the
1185  * return is greater than or equal to @size, the resulting
1186  * string is truncated.
1187  *
1188  * If you're not already dealing with a va_list consider using snprintf().
1189  */
1190 int vsnprintf(char *buf, size_t size, const char *fmt, va_list args)
1191 {
1192         unsigned long long num;
1193         char *str, *end;
1194         struct printf_spec spec = {0};
1195
1196         /* Reject out-of-range values early.  Large positive sizes are
1197            used for unknown buffer sizes. */
1198         if (WARN_ON_ONCE((int) size < 0))
1199                 return 0;
1200
1201         str = buf;
1202         end = buf + size;
1203
1204         /* Make sure end is always >= buf */
1205         if (end < buf) {
1206                 end = ((void *)-1);
1207                 size = end - buf;
1208         }
1209
1210         while (*fmt) {
1211                 const char *old_fmt = fmt;
1212                 int read = format_decode(fmt, &spec);
1213
1214                 fmt += read;
1215
1216                 switch (spec.type) {
1217                 case FORMAT_TYPE_NONE: {
1218                         int copy = read;
1219                         if (str < end) {
1220                                 if (copy > end - str)
1221                                         copy = end - str;
1222                                 memcpy(str, old_fmt, copy);
1223                         }
1224                         str += read;
1225                         break;
1226                 }
1227
1228                 case FORMAT_TYPE_WIDTH:
1229                         spec.field_width = va_arg(args, int);
1230                         break;
1231
1232                 case FORMAT_TYPE_PRECISION:
1233                         spec.precision = va_arg(args, int);
1234                         break;
1235
1236                 case FORMAT_TYPE_CHAR: {
1237                         char c;
1238
1239                         if (!(spec.flags & LEFT)) {
1240                                 while (--spec.field_width > 0) {
1241                                         if (str < end)
1242                                                 *str = ' ';
1243                                         ++str;
1244
1245                                 }
1246                         }
1247                         c = (unsigned char) va_arg(args, int);
1248                         if (str < end)
1249                                 *str = c;
1250                         ++str;
1251                         while (--spec.field_width > 0) {
1252                                 if (str < end)
1253                                         *str = ' ';
1254                                 ++str;
1255                         }
1256                         break;
1257                 }
1258
1259                 case FORMAT_TYPE_STR:
1260                         str = string(str, end, va_arg(args, char *), spec);
1261                         break;
1262
1263                 case FORMAT_TYPE_PTR:
1264                         str = pointer(fmt+1, str, end, va_arg(args, void *),
1265                                       spec);
1266                         while (isalnum(*fmt))
1267                                 fmt++;
1268                         break;
1269
1270                 case FORMAT_TYPE_PERCENT_CHAR:
1271                         if (str < end)
1272                                 *str = '%';
1273                         ++str;
1274                         break;
1275
1276                 case FORMAT_TYPE_INVALID:
1277                         if (str < end)
1278                                 *str = '%';
1279                         ++str;
1280                         break;
1281
1282                 case FORMAT_TYPE_NRCHARS: {
1283                         u8 qualifier = spec.qualifier;
1284
1285                         if (qualifier == 'l') {
1286                                 long *ip = va_arg(args, long *);
1287                                 *ip = (str - buf);
1288                         } else if (_tolower(qualifier) == 'z') {
1289                                 size_t *ip = va_arg(args, size_t *);
1290                                 *ip = (str - buf);
1291                         } else {
1292                                 int *ip = va_arg(args, int *);
1293                                 *ip = (str - buf);
1294                         }
1295                         break;
1296                 }
1297
1298                 default:
1299                         switch (spec.type) {
1300                         case FORMAT_TYPE_LONG_LONG:
1301                                 num = va_arg(args, long long);
1302                                 break;
1303                         case FORMAT_TYPE_ULONG:
1304                                 num = va_arg(args, unsigned long);
1305                                 break;
1306                         case FORMAT_TYPE_LONG:
1307                                 num = va_arg(args, long);
1308                                 break;
1309                         case FORMAT_TYPE_SIZE_T:
1310                                 num = va_arg(args, size_t);
1311                                 break;
1312                         case FORMAT_TYPE_PTRDIFF:
1313                                 num = va_arg(args, ptrdiff_t);
1314                                 break;
1315                         case FORMAT_TYPE_UBYTE:
1316                                 num = (unsigned char) va_arg(args, int);
1317                                 break;
1318                         case FORMAT_TYPE_BYTE:
1319                                 num = (signed char) va_arg(args, int);
1320                                 break;
1321                         case FORMAT_TYPE_USHORT:
1322                                 num = (unsigned short) va_arg(args, int);
1323                                 break;
1324                         case FORMAT_TYPE_SHORT:
1325                                 num = (short) va_arg(args, int);
1326                                 break;
1327                         case FORMAT_TYPE_INT:
1328                                 num = (int) va_arg(args, int);
1329                                 break;
1330                         default:
1331                                 num = va_arg(args, unsigned int);
1332                         }
1333
1334                         str = number(str, end, num, spec);
1335                 }
1336         }
1337
1338         if (size > 0) {
1339                 if (str < end)
1340                         *str = '\0';
1341                 else
1342                         end[-1] = '\0';
1343         }
1344
1345         /* the trailing null byte doesn't count towards the total */
1346         return str-buf;
1347
1348 }
1349 EXPORT_SYMBOL(vsnprintf);
1350
1351 /**
1352  * vscnprintf - Format a string and place it in a buffer
1353  * @buf: The buffer to place the result into
1354  * @size: The size of the buffer, including the trailing null space
1355  * @fmt: The format string to use
1356  * @args: Arguments for the format string
1357  *
1358  * The return value is the number of characters which have been written into
1359  * the @buf not including the trailing '\0'. If @size is == 0 the function
1360  * returns 0.
1361  *
1362  * If you're not already dealing with a va_list consider using scnprintf().
1363  *
1364  * See the vsnprintf() documentation for format string extensions over C99.
1365  */
1366 int vscnprintf(char *buf, size_t size, const char *fmt, va_list args)
1367 {
1368         int i;
1369
1370         i = vsnprintf(buf, size, fmt, args);
1371
1372         if (likely(i < size))
1373                 return i;
1374         if (size != 0)
1375                 return size - 1;
1376         return 0;
1377 }
1378 EXPORT_SYMBOL(vscnprintf);
1379
1380 /**
1381  * snprintf - 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 which would be
1388  * generated for the given input, excluding the trailing null,
1389  * as per ISO C99.  If the return is greater than or equal to
1390  * @size, the resulting string is truncated.
1391  *
1392  * See the vsnprintf() documentation for format string extensions over C99.
1393  */
1394 int snprintf(char *buf, size_t size, const char *fmt, ...)
1395 {
1396         va_list args;
1397         int i;
1398
1399         va_start(args, fmt);
1400         i = vsnprintf(buf, size, fmt, args);
1401         va_end(args);
1402
1403         return i;
1404 }
1405 EXPORT_SYMBOL(snprintf);
1406
1407 /**
1408  * scnprintf - Format a string and place it in a buffer
1409  * @buf: The buffer to place the result into
1410  * @size: The size of the buffer, including the trailing null space
1411  * @fmt: The format string to use
1412  * @...: Arguments for the format string
1413  *
1414  * The return value is the number of characters written into @buf not including
1415  * the trailing '\0'. If @size is == 0 the function returns 0.
1416  */
1417
1418 int scnprintf(char *buf, size_t size, const char *fmt, ...)
1419 {
1420         va_list args;
1421         int i;
1422
1423         va_start(args, fmt);
1424         i = vscnprintf(buf, size, fmt, args);
1425         va_end(args);
1426
1427         return i;
1428 }
1429 EXPORT_SYMBOL(scnprintf);
1430
1431 /**
1432  * vsprintf - Format a string and place it in a buffer
1433  * @buf: The buffer to place the result into
1434  * @fmt: The format string to use
1435  * @args: Arguments for the format string
1436  *
1437  * The function returns the number of characters written
1438  * into @buf. Use vsnprintf() or vscnprintf() in order to avoid
1439  * buffer overflows.
1440  *
1441  * If you're not already dealing with a va_list consider using sprintf().
1442  *
1443  * See the vsnprintf() documentation for format string extensions over C99.
1444  */
1445 int vsprintf(char *buf, const char *fmt, va_list args)
1446 {
1447         return vsnprintf(buf, INT_MAX, fmt, args);
1448 }
1449 EXPORT_SYMBOL(vsprintf);
1450
1451 /**
1452  * sprintf - Format a string and place it in a buffer
1453  * @buf: The buffer to place the result into
1454  * @fmt: The format string to use
1455  * @...: Arguments for the format string
1456  *
1457  * The function returns the number of characters written
1458  * into @buf. Use snprintf() or scnprintf() in order to avoid
1459  * buffer overflows.
1460  *
1461  * See the vsnprintf() documentation for format string extensions over C99.
1462  */
1463 int sprintf(char *buf, const char *fmt, ...)
1464 {
1465         va_list args;
1466         int i;
1467
1468         va_start(args, fmt);
1469         i = vsnprintf(buf, INT_MAX, fmt, args);
1470         va_end(args);
1471
1472         return i;
1473 }
1474 EXPORT_SYMBOL(sprintf);
1475
1476 #ifdef CONFIG_BINARY_PRINTF
1477 /*
1478  * bprintf service:
1479  * vbin_printf() - VA arguments to binary data
1480  * bstr_printf() - Binary data to text string
1481  */
1482
1483 /**
1484  * vbin_printf - Parse a format string and place args' binary value in a buffer
1485  * @bin_buf: The buffer to place args' binary value
1486  * @size: The size of the buffer(by words(32bits), not characters)
1487  * @fmt: The format string to use
1488  * @args: Arguments for the format string
1489  *
1490  * The format follows C99 vsnprintf, except %n is ignored, and its argument
1491  * is skiped.
1492  *
1493  * The return value is the number of words(32bits) which would be generated for
1494  * the given input.
1495  *
1496  * NOTE:
1497  * If the return value is greater than @size, the resulting bin_buf is NOT
1498  * valid for bstr_printf().
1499  */
1500 int vbin_printf(u32 *bin_buf, size_t size, const char *fmt, va_list args)
1501 {
1502         struct printf_spec spec = {0};
1503         char *str, *end;
1504
1505         str = (char *)bin_buf;
1506         end = (char *)(bin_buf + size);
1507
1508 #define save_arg(type)                                                  \
1509 do {                                                                    \
1510         if (sizeof(type) == 8) {                                        \
1511                 unsigned long long value;                               \
1512                 str = PTR_ALIGN(str, sizeof(u32));                      \
1513                 value = va_arg(args, unsigned long long);               \
1514                 if (str + sizeof(type) <= end) {                        \
1515                         *(u32 *)str = *(u32 *)&value;                   \
1516                         *(u32 *)(str + 4) = *((u32 *)&value + 1);       \
1517                 }                                                       \
1518         } else {                                                        \
1519                 unsigned long value;                                    \
1520                 str = PTR_ALIGN(str, sizeof(type));                     \
1521                 value = va_arg(args, int);                              \
1522                 if (str + sizeof(type) <= end)                          \
1523                         *(typeof(type) *)str = (type)value;             \
1524         }                                                               \
1525         str += sizeof(type);                                            \
1526 } while (0)
1527
1528         while (*fmt) {
1529                 int read = format_decode(fmt, &spec);
1530
1531                 fmt += read;
1532
1533                 switch (spec.type) {
1534                 case FORMAT_TYPE_NONE:
1535                 case FORMAT_TYPE_INVALID:
1536                 case FORMAT_TYPE_PERCENT_CHAR:
1537                         break;
1538
1539                 case FORMAT_TYPE_WIDTH:
1540                 case FORMAT_TYPE_PRECISION:
1541                         save_arg(int);
1542                         break;
1543
1544                 case FORMAT_TYPE_CHAR:
1545                         save_arg(char);
1546                         break;
1547
1548                 case FORMAT_TYPE_STR: {
1549                         const char *save_str = va_arg(args, char *);
1550                         size_t len;
1551
1552                         if ((unsigned long)save_str > (unsigned long)-PAGE_SIZE
1553                                         || (unsigned long)save_str < PAGE_SIZE)
1554                                 save_str = "(null)";
1555                         len = strlen(save_str) + 1;
1556                         if (str + len < end)
1557                                 memcpy(str, save_str, len);
1558                         str += len;
1559                         break;
1560                 }
1561
1562                 case FORMAT_TYPE_PTR:
1563                         save_arg(void *);
1564                         /* skip all alphanumeric pointer suffixes */
1565                         while (isalnum(*fmt))
1566                                 fmt++;
1567                         break;
1568
1569                 case FORMAT_TYPE_NRCHARS: {
1570                         /* skip %n 's argument */
1571                         u8 qualifier = spec.qualifier;
1572                         void *skip_arg;
1573                         if (qualifier == 'l')
1574                                 skip_arg = va_arg(args, long *);
1575                         else if (_tolower(qualifier) == 'z')
1576                                 skip_arg = va_arg(args, size_t *);
1577                         else
1578                                 skip_arg = va_arg(args, int *);
1579                         break;
1580                 }
1581
1582                 default:
1583                         switch (spec.type) {
1584
1585                         case FORMAT_TYPE_LONG_LONG:
1586                                 save_arg(long long);
1587                                 break;
1588                         case FORMAT_TYPE_ULONG:
1589                         case FORMAT_TYPE_LONG:
1590                                 save_arg(unsigned long);
1591                                 break;
1592                         case FORMAT_TYPE_SIZE_T:
1593                                 save_arg(size_t);
1594                                 break;
1595                         case FORMAT_TYPE_PTRDIFF:
1596                                 save_arg(ptrdiff_t);
1597                                 break;
1598                         case FORMAT_TYPE_UBYTE:
1599                         case FORMAT_TYPE_BYTE:
1600                                 save_arg(char);
1601                                 break;
1602                         case FORMAT_TYPE_USHORT:
1603                         case FORMAT_TYPE_SHORT:
1604                                 save_arg(short);
1605                                 break;
1606                         default:
1607                                 save_arg(int);
1608                         }
1609                 }
1610         }
1611
1612         return (u32 *)(PTR_ALIGN(str, sizeof(u32))) - bin_buf;
1613 #undef save_arg
1614 }
1615 EXPORT_SYMBOL_GPL(vbin_printf);
1616
1617 /**
1618  * bstr_printf - Format a string from binary arguments and place it in a buffer
1619  * @buf: The buffer to place the result into
1620  * @size: The size of the buffer, including the trailing null space
1621  * @fmt: The format string to use
1622  * @bin_buf: Binary arguments for the format string
1623  *
1624  * This function like C99 vsnprintf, but the difference is that vsnprintf gets
1625  * arguments from stack, and bstr_printf gets arguments from @bin_buf which is
1626  * a binary buffer that generated by vbin_printf.
1627  *
1628  * The format follows C99 vsnprintf, but has some extensions:
1629  *  see vsnprintf comment for details.
1630  *
1631  * The return value is the number of characters which would
1632  * be generated for the given input, excluding the trailing
1633  * '\0', as per ISO C99. If you want to have the exact
1634  * number of characters written into @buf as return value
1635  * (not including the trailing '\0'), use vscnprintf(). If the
1636  * return is greater than or equal to @size, the resulting
1637  * string is truncated.
1638  */
1639 int bstr_printf(char *buf, size_t size, const char *fmt, const u32 *bin_buf)
1640 {
1641         struct printf_spec spec = {0};
1642         char *str, *end;
1643         const char *args = (const char *)bin_buf;
1644
1645         if (WARN_ON_ONCE((int) size < 0))
1646                 return 0;
1647
1648         str = buf;
1649         end = buf + size;
1650
1651 #define get_arg(type)                                                   \
1652 ({                                                                      \
1653         typeof(type) value;                                             \
1654         if (sizeof(type) == 8) {                                        \
1655                 args = PTR_ALIGN(args, sizeof(u32));                    \
1656                 *(u32 *)&value = *(u32 *)args;                          \
1657                 *((u32 *)&value + 1) = *(u32 *)(args + 4);              \
1658         } else {                                                        \
1659                 args = PTR_ALIGN(args, sizeof(type));                   \
1660                 value = *(typeof(type) *)args;                          \
1661         }                                                               \
1662         args += sizeof(type);                                           \
1663         value;                                                          \
1664 })
1665
1666         /* Make sure end is always >= buf */
1667         if (end < buf) {
1668                 end = ((void *)-1);
1669                 size = end - buf;
1670         }
1671
1672         while (*fmt) {
1673                 const char *old_fmt = fmt;
1674                 int read = format_decode(fmt, &spec);
1675
1676                 fmt += read;
1677
1678                 switch (spec.type) {
1679                 case FORMAT_TYPE_NONE: {
1680                         int copy = read;
1681                         if (str < end) {
1682                                 if (copy > end - str)
1683                                         copy = end - str;
1684                                 memcpy(str, old_fmt, copy);
1685                         }
1686                         str += read;
1687                         break;
1688                 }
1689
1690                 case FORMAT_TYPE_WIDTH:
1691                         spec.field_width = get_arg(int);
1692                         break;
1693
1694                 case FORMAT_TYPE_PRECISION:
1695                         spec.precision = get_arg(int);
1696                         break;
1697
1698                 case FORMAT_TYPE_CHAR: {
1699                         char c;
1700
1701                         if (!(spec.flags & LEFT)) {
1702                                 while (--spec.field_width > 0) {
1703                                         if (str < end)
1704                                                 *str = ' ';
1705                                         ++str;
1706                                 }
1707                         }
1708                         c = (unsigned char) get_arg(char);
1709                         if (str < end)
1710                                 *str = c;
1711                         ++str;
1712                         while (--spec.field_width > 0) {
1713                                 if (str < end)
1714                                         *str = ' ';
1715                                 ++str;
1716                         }
1717                         break;
1718                 }
1719
1720                 case FORMAT_TYPE_STR: {
1721                         const char *str_arg = args;
1722                         args += strlen(str_arg) + 1;
1723                         str = string(str, end, (char *)str_arg, spec);
1724                         break;
1725                 }
1726
1727                 case FORMAT_TYPE_PTR:
1728                         str = pointer(fmt+1, str, end, get_arg(void *), spec);
1729                         while (isalnum(*fmt))
1730                                 fmt++;
1731                         break;
1732
1733                 case FORMAT_TYPE_PERCENT_CHAR:
1734                 case FORMAT_TYPE_INVALID:
1735                         if (str < end)
1736                                 *str = '%';
1737                         ++str;
1738                         break;
1739
1740                 case FORMAT_TYPE_NRCHARS:
1741                         /* skip */
1742                         break;
1743
1744                 default: {
1745                         unsigned long long num;
1746
1747                         switch (spec.type) {
1748
1749                         case FORMAT_TYPE_LONG_LONG:
1750                                 num = get_arg(long long);
1751                                 break;
1752                         case FORMAT_TYPE_ULONG:
1753                         case FORMAT_TYPE_LONG:
1754                                 num = get_arg(unsigned long);
1755                                 break;
1756                         case FORMAT_TYPE_SIZE_T:
1757                                 num = get_arg(size_t);
1758                                 break;
1759                         case FORMAT_TYPE_PTRDIFF:
1760                                 num = get_arg(ptrdiff_t);
1761                                 break;
1762                         case FORMAT_TYPE_UBYTE:
1763                                 num = get_arg(unsigned char);
1764                                 break;
1765                         case FORMAT_TYPE_BYTE:
1766                                 num = get_arg(signed char);
1767                                 break;
1768                         case FORMAT_TYPE_USHORT:
1769                                 num = get_arg(unsigned short);
1770                                 break;
1771                         case FORMAT_TYPE_SHORT:
1772                                 num = get_arg(short);
1773                                 break;
1774                         case FORMAT_TYPE_UINT:
1775                                 num = get_arg(unsigned int);
1776                                 break;
1777                         default:
1778                                 num = get_arg(int);
1779                         }
1780
1781                         str = number(str, end, num, spec);
1782                 } /* default: */
1783                 } /* switch(spec.type) */
1784         } /* while(*fmt) */
1785
1786         if (size > 0) {
1787                 if (str < end)
1788                         *str = '\0';
1789                 else
1790                         end[-1] = '\0';
1791         }
1792
1793 #undef get_arg
1794
1795         /* the trailing null byte doesn't count towards the total */
1796         return str - buf;
1797 }
1798 EXPORT_SYMBOL_GPL(bstr_printf);
1799
1800 /**
1801  * bprintf - Parse a format string and place args' binary value in a buffer
1802  * @bin_buf: The buffer to place args' binary value
1803  * @size: The size of the buffer(by words(32bits), not characters)
1804  * @fmt: The format string to use
1805  * @...: Arguments for the format string
1806  *
1807  * The function returns the number of words(u32) written
1808  * into @bin_buf.
1809  */
1810 int bprintf(u32 *bin_buf, size_t size, const char *fmt, ...)
1811 {
1812         va_list args;
1813         int ret;
1814
1815         va_start(args, fmt);
1816         ret = vbin_printf(bin_buf, size, fmt, args);
1817         va_end(args);
1818
1819         return ret;
1820 }
1821 EXPORT_SYMBOL_GPL(bprintf);
1822
1823 #endif /* CONFIG_BINARY_PRINTF */
1824
1825 /**
1826  * vsscanf - Unformat a buffer into a list of arguments
1827  * @buf:        input buffer
1828  * @fmt:        format of buffer
1829  * @args:       arguments
1830  */
1831 int vsscanf(const char *buf, const char *fmt, va_list args)
1832 {
1833         const char *str = buf;
1834         char *next;
1835         char digit;
1836         int num = 0;
1837         u8 qualifier;
1838         u8 base;
1839         s16 field_width;
1840         bool is_sign;
1841
1842         while (*fmt && *str) {
1843                 /* skip any white space in format */
1844                 /* white space in format matchs any amount of
1845                  * white space, including none, in the input.
1846                  */
1847                 if (isspace(*fmt)) {
1848                         fmt = skip_spaces(++fmt);
1849                         str = skip_spaces(str);
1850                 }
1851
1852                 /* anything that is not a conversion must match exactly */
1853                 if (*fmt != '%' && *fmt) {
1854                         if (*fmt++ != *str++)
1855                                 break;
1856                         continue;
1857                 }
1858
1859                 if (!*fmt)
1860                         break;
1861                 ++fmt;
1862
1863                 /* skip this conversion.
1864                  * advance both strings to next white space
1865                  */
1866                 if (*fmt == '*') {
1867                         while (!isspace(*fmt) && *fmt != '%' && *fmt)
1868                                 fmt++;
1869                         while (!isspace(*str) && *str)
1870                                 str++;
1871                         continue;
1872                 }
1873
1874                 /* get field width */
1875                 field_width = -1;
1876                 if (isdigit(*fmt))
1877                         field_width = skip_atoi(&fmt);
1878
1879                 /* get conversion qualifier */
1880                 qualifier = -1;
1881                 if (*fmt == 'h' || _tolower(*fmt) == 'l' ||
1882                     _tolower(*fmt) == 'z') {
1883                         qualifier = *fmt++;
1884                         if (unlikely(qualifier == *fmt)) {
1885                                 if (qualifier == 'h') {
1886                                         qualifier = 'H';
1887                                         fmt++;
1888                                 } else if (qualifier == 'l') {
1889                                         qualifier = 'L';
1890                                         fmt++;
1891                                 }
1892                         }
1893                 }
1894
1895                 if (!*fmt || !*str)
1896                         break;
1897
1898                 base = 10;
1899                 is_sign = 0;
1900
1901                 switch (*fmt++) {
1902                 case 'c':
1903                 {
1904                         char *s = (char *)va_arg(args, char*);
1905                         if (field_width == -1)
1906                                 field_width = 1;
1907                         do {
1908                                 *s++ = *str++;
1909                         } while (--field_width > 0 && *str);
1910                         num++;
1911                 }
1912                 continue;
1913                 case 's':
1914                 {
1915                         char *s = (char *)va_arg(args, char *);
1916                         if (field_width == -1)
1917                                 field_width = SHRT_MAX;
1918                         /* first, skip leading white space in buffer */
1919                         str = skip_spaces(str);
1920
1921                         /* now copy until next white space */
1922                         while (*str && !isspace(*str) && field_width--)
1923                                 *s++ = *str++;
1924                         *s = '\0';
1925                         num++;
1926                 }
1927                 continue;
1928                 case 'n':
1929                         /* return number of characters read so far */
1930                 {
1931                         int *i = (int *)va_arg(args, int*);
1932                         *i = str - buf;
1933                 }
1934                 continue;
1935                 case 'o':
1936                         base = 8;
1937                         break;
1938                 case 'x':
1939                 case 'X':
1940                         base = 16;
1941                         break;
1942                 case 'i':
1943                         base = 0;
1944                 case 'd':
1945                         is_sign = 1;
1946                 case 'u':
1947                         break;
1948                 case '%':
1949                         /* looking for '%' in str */
1950                         if (*str++ != '%')
1951                                 return num;
1952                         continue;
1953                 default:
1954                         /* invalid format; stop here */
1955                         return num;
1956                 }
1957
1958                 /* have some sort of integer conversion.
1959                  * first, skip white space in buffer.
1960                  */
1961                 str = skip_spaces(str);
1962
1963                 digit = *str;
1964                 if (is_sign && digit == '-')
1965                         digit = *(str + 1);
1966
1967                 if (!digit
1968                     || (base == 16 && !isxdigit(digit))
1969                     || (base == 10 && !isdigit(digit))
1970                     || (base == 8 && (!isdigit(digit) || digit > '7'))
1971                     || (base == 0 && !isdigit(digit)))
1972                         break;
1973
1974                 switch (qualifier) {
1975                 case 'H':       /* that's 'hh' in format */
1976                         if (is_sign) {
1977                                 signed char *s = (signed char *)va_arg(args, signed char *);
1978                                 *s = (signed char)simple_strtol(str, &next, base);
1979                         } else {
1980                                 unsigned char *s = (unsigned char *)va_arg(args, unsigned char *);
1981                                 *s = (unsigned char)simple_strtoul(str, &next, base);
1982                         }
1983                         break;
1984                 case 'h':
1985                         if (is_sign) {
1986                                 short *s = (short *)va_arg(args, short *);
1987                                 *s = (short)simple_strtol(str, &next, base);
1988                         } else {
1989                                 unsigned short *s = (unsigned short *)va_arg(args, unsigned short *);
1990                                 *s = (unsigned short)simple_strtoul(str, &next, base);
1991                         }
1992                         break;
1993                 case 'l':
1994                         if (is_sign) {
1995                                 long *l = (long *)va_arg(args, long *);
1996                                 *l = simple_strtol(str, &next, base);
1997                         } else {
1998                                 unsigned long *l = (unsigned long *)va_arg(args, unsigned long *);
1999                                 *l = simple_strtoul(str, &next, base);
2000                         }
2001                         break;
2002                 case 'L':
2003                         if (is_sign) {
2004                                 long long *l = (long long *)va_arg(args, long long *);
2005                                 *l = simple_strtoll(str, &next, base);
2006                         } else {
2007                                 unsigned long long *l = (unsigned long long *)va_arg(args, unsigned long long *);
2008                                 *l = simple_strtoull(str, &next, base);
2009                         }
2010                         break;
2011                 case 'Z':
2012                 case 'z':
2013                 {
2014                         size_t *s = (size_t *)va_arg(args, size_t *);
2015                         *s = (size_t)simple_strtoul(str, &next, base);
2016                 }
2017                 break;
2018                 default:
2019                         if (is_sign) {
2020                                 int *i = (int *)va_arg(args, int *);
2021                                 *i = (int)simple_strtol(str, &next, base);
2022                         } else {
2023                                 unsigned int *i = (unsigned int *)va_arg(args, unsigned int*);
2024                                 *i = (unsigned int)simple_strtoul(str, &next, base);
2025                         }
2026                         break;
2027                 }
2028                 num++;
2029
2030                 if (!next)
2031                         break;
2032                 str = next;
2033         }
2034
2035         /*
2036          * Now we've come all the way through so either the input string or the
2037          * format ended. In the former case, there can be a %n at the current
2038          * position in the format that needs to be filled.
2039          */
2040         if (*fmt == '%' && *(fmt + 1) == 'n') {
2041                 int *p = (int *)va_arg(args, int *);
2042                 *p = str - buf;
2043         }
2044
2045         return num;
2046 }
2047 EXPORT_SYMBOL(vsscanf);
2048
2049 /**
2050  * sscanf - Unformat a buffer into a list of arguments
2051  * @buf:        input buffer
2052  * @fmt:        formatting of buffer
2053  * @...:        resulting arguments
2054  */
2055 int sscanf(const char *buf, const char *fmt, ...)
2056 {
2057         va_list args;
2058         int i;
2059
2060         va_start(args, fmt);
2061         i = vsscanf(buf, fmt, args);
2062         va_end(args);
2063
2064         return i;
2065 }
2066 EXPORT_SYMBOL(sscanf);