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 #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 #define ZEROPAD 1               /* pad with zero */
 216 #define SIGN    2               /* unsigned/signed long */
 217 #define PLUS    4               /* show plus */
 218 #define SPACE   8               /* space if plus */
 219 #define LEFT    16              /* left justified */
 220 #define SMALL   32              /* use lowercase in hex (must be 32 == 0x20) */
 221 #define SPECIAL 64              /* prefix hex with "0x", octal with "0" */
 222
 223 enum format_type {
 224         FORMAT_TYPE_NONE, /* Just a string part */
 225         FORMAT_TYPE_WIDTH,
 226         FORMAT_TYPE_PRECISION,
 227         FORMAT_TYPE_CHAR,
 228         FORMAT_TYPE_STR,
 229         FORMAT_TYPE_PTR,
 230         FORMAT_TYPE_PERCENT_CHAR,
 231         FORMAT_TYPE_INVALID,
 232         FORMAT_TYPE_LONG_LONG,
 233         FORMAT_TYPE_ULONG,
 234         FORMAT_TYPE_LONG,
 235         FORMAT_TYPE_UBYTE,
 236         FORMAT_TYPE_BYTE,
 237         FORMAT_TYPE_USHORT,
 238         FORMAT_TYPE_SHORT,
 239         FORMAT_TYPE_UINT,
 240         FORMAT_TYPE_INT,
 241         FORMAT_TYPE_NRCHARS,
 242         FORMAT_TYPE_SIZE_T,
 243         FORMAT_TYPE_PTRDIFF
 244 };
 245
 246 struct printf_spec {
 247         u8      type;           /* format_type enum */
 248         u8      flags;          /* flags to number() */
 249         u8      base;           /* number base, 8, 10 or 16 only */
 250         u8      qualifier;      /* number qualifier, one of 'hHlLtzZ' */
 251         s16     field_width;    /* width of output field */
 252         s16     precision;      /* # of digits/chars */
 253 };
 254
 255 static noinline_for_stack
 256 char *number(char *buf, char *end, unsigned long long num,
 257              struct printf_spec spec)
 258 {
 259         /* we are called with base 8, 10 or 16, only, thus don't need "G..."  */
 260         static const char digits[16] = "0123456789ABCDEF"; /* "GHIJKLMNOPQRSTUVWXYZ"; */
 261
 262         char tmp[66];
 263         char sign;
 264         char locase;
 265         int need_pfx = ((spec.flags & SPECIAL) && spec.base != 10);
 266         int i;
 267
 268         /* locase = 0 or 0x20. ORing digits or letters with 'locase'
 269          * produces same digits or (maybe lowercased) letters */
 270         locase = (spec.flags & SMALL);
 271         if (spec.flags & LEFT)
 272                 spec.flags &= ~ZEROPAD;
 273         sign = 0;
 274         if (spec.flags & SIGN) {
 275                 if ((signed long long)num < 0) {
 276                         sign = '-';
 277                         num = -(signed long long)num;
 278                         spec.field_width--;
 279                 } else if (spec.flags & PLUS) {
 280                         sign = '+';
 281                         spec.field_width--;
 282                 } else if (spec.flags & SPACE) {
 283                         sign = ' ';
 284                         spec.field_width--;
 285                 }
 286         }
 287         if (need_pfx) {
 288                 spec.field_width--;
 289                 if (spec.base == 16)
 290                         spec.field_width--;
 291         }
 292
 293         /* generate full string in tmp[], in reverse order */
 294         i = 0;
 295         if (num == 0)
 296                 tmp[i++] = '0';
 297         /* Generic code, for any base:
 298         else do {
 299                 tmp[i++] = (digits[do_div(num,base)] | locase);
 300         } while (num != 0);
 301         */
 302         else if (spec.base != 10) { /* 8 or 16 */
 303                 int mask = spec.base - 1;
 304                 int shift = 3;
 305
 306                 if (spec.base == 16)
 307                         shift = 4;
 308                 do {
 309                         tmp[i++] = (digits[((unsigned char)num) & mask] | locase);
 310                         num >>= shift;
 311                 } while (num);
 312         } else { /* base 10 */
 313                 i = put_dec(tmp, num) - tmp;
 314         }
 315
 316         /* printing 100 using %2d gives "100", not "00" */
 317         if (i > spec.precision)
 318                 spec.precision = i;
 319         /* leading space padding */
 320         spec.field_width -= spec.precision;
 321         if (!(spec.flags & (ZEROPAD+LEFT))) {
 322                 while (--spec.field_width >= 0) {
 323                         if (buf < end)
 324                                 *buf = ' ';
 325                         ++buf;
 326                 }
 327         }
 328         /* sign */
 329         if (sign) {
 330                 if (buf < end)
 331                         *buf = sign;
 332                 ++buf;
 333         }
 334         /* "0x" / "0" prefix */
 335         if (need_pfx) {
 336                 if (buf < end)
 337                         *buf = '0';
 338                 ++buf;
 339                 if (spec.base == 16) {
 340                         if (buf < end)
 341                                 *buf = ('X' | locase);
 342                         ++buf;
 343                 }
 344         }
 345         /* zero or space padding */
 346         if (!(spec.flags & LEFT)) {
 347                 char c = (spec.flags & ZEROPAD) ? '0' : ' ';
 348                 while (--spec.field_width >= 0) {
 349                         if (buf < end)
 350                                 *buf = c;
 351                         ++buf;
 352                 }
 353         }
 354         /* hmm even more zero padding? */
 355         while (i <= --spec.precision) {
 356                 if (buf < end)
 357                         *buf = '0';
 358                 ++buf;
 359         }
 360         /* actual digits of result */
 361         while (--i >= 0) {
 362                 if (buf < end)
 363                         *buf = tmp[i];
 364                 ++buf;
 365         }
 366         /* trailing space padding */
 367         while (--spec.field_width >= 0) {
 368                 if (buf < end)
 369                         *buf = ' ';
 370                 ++buf;
 371         }
 372
 373         return buf;
 374 }
 375
 376 static noinline_for_stack
 377 char *string(char *buf, char *end, const char *s, struct printf_spec spec)
 378 {
 379         int len, i;
 380
 381         if ((unsigned long)s < PAGE_SIZE)
 382                 s = "(null)";
 383
 384         len = strnlen(s, spec.precision);
 385
 386         if (!(spec.flags & LEFT)) {
 387                 while (len < spec.field_width--) {
 388                         if (buf < end)
 389                                 *buf = ' ';
 390                         ++buf;
 391                 }
 392         }
 393         for (i = 0; i < len; ++i) {
 394                 if (buf < end)
 395                         *buf = *s;
 396                 ++buf; ++s;
 397         }
 398         while (len < spec.field_width--) {
 399                 if (buf < end)
 400                         *buf = ' ';
 401                 ++buf;
 402         }
 403
 404         return buf;
 405 }
 406
 407 static noinline_for_stack
 408 char *symbol_string(char *buf, char *end, void *ptr,
 409                     struct printf_spec spec, char ext)
 410 {
 411         unsigned long value = (unsigned long) ptr;
 412 #ifdef CONFIG_KALLSYMS
 413         char sym[KSYM_SYMBOL_LEN];
 414         if (ext == 'B')
 415                 sprint_backtrace(sym, value);
 416         else if (ext != 'f' && ext != 's')
 417                 sprint_symbol(sym, value);
 418         else
 419                 kallsyms_lookup(value, NULL, NULL, NULL, sym);
 420
 421         return string(buf, end, sym, spec);
 422 #else
 423         spec.field_width = 2 * sizeof(void *);
 424         spec.flags |= SPECIAL | SMALL | ZEROPAD;
 425         spec.base = 16;
 426
 427         return number(buf, end, value, spec);
 428 #endif
 429 }
 430
 431 static noinline_for_stack
 432 char *resource_string(char *buf, char *end, struct resource *res,
 433                       struct printf_spec spec, const char *fmt)
 434 {
 435 #ifndef IO_RSRC_PRINTK_SIZE
 436 #define IO_RSRC_PRINTK_SIZE     6
 437 #endif
 438
 439 #ifndef MEM_RSRC_PRINTK_SIZE
 440 #define MEM_RSRC_PRINTK_SIZE    10
 441 #endif
 442         static const struct printf_spec io_spec = {
 443                 .base = 16,
 444                 .field_width = IO_RSRC_PRINTK_SIZE,
 445                 .precision = -1,
 446                 .flags = SPECIAL | SMALL | ZEROPAD,
 447         };
 448         static const struct printf_spec mem_spec = {
 449                 .base = 16,
 450                 .field_width = MEM_RSRC_PRINTK_SIZE,
 451                 .precision = -1,
 452                 .flags = SPECIAL | SMALL | ZEROPAD,
 453         };
 454         static const struct printf_spec bus_spec = {
 455                 .base = 16,
 456                 .field_width = 2,
 457                 .precision = -1,
 458                 .flags = SMALL | ZEROPAD,
 459         };
 460         static const struct printf_spec dec_spec = {
 461                 .base = 10,
 462                 .precision = -1,
 463                 .flags = 0,
 464         };
 465         static const struct printf_spec str_spec = {
 466                 .field_width = -1,
 467                 .precision = 10,
 468                 .flags = LEFT,
 469         };
 470         static const struct printf_spec flag_spec = {
 471                 .base = 16,
 472                 .precision = -1,
 473                 .flags = SPECIAL | SMALL,
 474         };
 475
 476         /* 32-bit res (sizeof==4): 10 chars in dec, 10 in hex ("0x" + 8)
 477          * 64-bit res (sizeof==8): 20 chars in dec, 18 in hex ("0x" + 16) */
 478 #define RSRC_BUF_SIZE           ((2 * sizeof(resource_size_t)) + 4)
 479 #define FLAG_BUF_SIZE           (2 * sizeof(res->flags))
 480 #define DECODED_BUF_SIZE        sizeof("[mem - 64bit pref window disabled]")
 481 #define RAW_BUF_SIZE            sizeof("[mem - flags 0x]")
 482         char sym[max(2*RSRC_BUF_SIZE + DECODED_BUF_SIZE,
 483                      2*RSRC_BUF_SIZE + FLAG_BUF_SIZE + RAW_BUF_SIZE)];
 484
 485         char *p = sym, *pend = sym + sizeof(sym);
 486         int decode = (fmt[0] == 'R') ? 1 : 0;
 487         const struct printf_spec *specp;
 488
 489         *p++ = '[';
 490         if (res->flags & IORESOURCE_IO) {
 491                 p = string(p, pend, "io  ", str_spec);
 492                 specp = &io_spec;
 493         } else if (res->flags & IORESOURCE_MEM) {
 494                 p = string(p, pend, "mem ", str_spec);
 495                 specp = &mem_spec;
 496         } else if (res->flags & IORESOURCE_IRQ) {
 497                 p = string(p, pend, "irq ", str_spec);
 498                 specp = &dec_spec;
 499         } else if (res->flags & IORESOURCE_DMA) {
 500                 p = string(p, pend, "dma ", str_spec);
 501                 specp = &dec_spec;
 502         } else if (res->flags & IORESOURCE_BUS) {
 503                 p = string(p, pend, "bus ", str_spec);
 504                 specp = &bus_spec;
 505         } else {
 506                 p = string(p, pend, "??? ", str_spec);
 507                 specp = &mem_spec;
 508                 decode = 0;
 509         }
 510         p = number(p, pend, res->start, *specp);
 511         if (res->start != res->end) {
 512                 *p++ = '-';
 513                 p = number(p, pend, res->end, *specp);
 514         }
 515         if (decode) {
 516                 if (res->flags & IORESOURCE_MEM_64)
 517                         p = string(p, pend, " 64bit", str_spec);
 518                 if (res->flags & IORESOURCE_PREFETCH)
 519                         p = string(p, pend, " pref", str_spec);
 520                 if (res->flags & IORESOURCE_WINDOW)
 521                         p = string(p, pend, " window", str_spec);
 522                 if (res->flags & IORESOURCE_DISABLED)
 523                         p = string(p, pend, " disabled", str_spec);
 524         } else {
 525                 p = string(p, pend, " flags ", str_spec);
 526                 p = number(p, pend, res->flags, flag_spec);
 527         }
 528         *p++ = ']';
 529         *p = '\0';
 530
 531         return string(buf, end, sym, spec);
 532 }
 533
 534 static noinline_for_stack
 535 char *mac_address_string(char *buf, char *end, u8 *addr,
 536                          struct printf_spec spec, const char *fmt)
 537 {
 538         char mac_addr[sizeof("xx:xx:xx:xx:xx:xx")];
 539         char *p = mac_addr;
 540         int i;
 541         char separator;
 542
 543         if (fmt[1] == 'F') {            /* FDDI canonical format */
 544                 separator = '-';
 545         } else {
 546                 separator = ':';
 547         }
 548
 549         for (i = 0; i < 6; i++) {
 550                 p = hex_byte_pack(p, addr[i]);
 551                 if (fmt[0] == 'M' && i != 5)
 552                         *p++ = separator;
 553         }
 554         *p = '\0';
 555
 556         return string(buf, end, mac_addr, spec);
 557 }
 558
 559 static noinline_for_stack
 560 char *ip4_string(char *p, const u8 *addr, const char *fmt)
 561 {
 562         int i;
 563         bool leading_zeros = (fmt[0] == 'i');
 564         int index;
 565         int step;
 566
 567         switch (fmt[2]) {
 568         case 'h':
 569 #ifdef __BIG_ENDIAN
 570                 index = 0;
 571                 step = 1;
 572 #else
 573                 index = 3;
 574                 step = -1;
 575 #endif
 576                 break;
 577         case 'l':
 578                 index = 3;
 579                 step = -1;
 580                 break;
 581         case 'n':
 582         case 'b':
 583         default:
 584                 index = 0;
 585                 step = 1;
 586                 break;
 587         }
 588         for (i = 0; i < 4; i++) {
 589                 char temp[3];   /* hold each IP quad in reverse order */
 590                 int digits = put_dec_trunc(temp, addr[index]) - temp;
 591                 if (leading_zeros) {
 592                         if (digits < 3)
 593                                 *p++ = '0';
 594                         if (digits < 2)
 595                                 *p++ = '0';
 596                 }
 597                 /* reverse the digits in the quad */
 598                 while (digits--)
 599                         *p++ = temp[digits];
 600                 if (i < 3)
 601                         *p++ = '.';
 602                 index += step;
 603         }
 604         *p = '\0';
 605
 606         return p;
 607 }
 608
 609 static noinline_for_stack
 610 char *ip6_compressed_string(char *p, const char *addr)
 611 {
 612         int i, j, range;
 613         unsigned char zerolength[8];
 614         int longest = 1;
 615         int colonpos = -1;
 616         u16 word;
 617         u8 hi, lo;
 618         bool needcolon = false;
 619         bool useIPv4;
 620         struct in6_addr in6;
 621
 622         memcpy(&in6, addr, sizeof(struct in6_addr));
 623
 624         useIPv4 = ipv6_addr_v4mapped(&in6) || ipv6_addr_is_isatap(&in6);
 625
 626         memset(zerolength, 0, sizeof(zerolength));
 627
 628         if (useIPv4)
 629                 range = 6;
 630         else
 631                 range = 8;
 632
 633         /* find position of longest 0 run */
 634         for (i = 0; i < range; i++) {
 635                 for (j = i; j < range; j++) {
 636                         if (in6.s6_addr16[j] != 0)
 637                                 break;
 638                         zerolength[i]++;
 639                 }
 640         }
 641         for (i = 0; i < range; i++) {
 642                 if (zerolength[i] > longest) {
 643                         longest = zerolength[i];
 644                         colonpos = i;
 645                 }
 646         }
 647         if (longest == 1)               /* don't compress a single 0 */
 648                 colonpos = -1;
 649
 650         /* emit address */
 651         for (i = 0; i < range; i++) {
 652                 if (i == colonpos) {
 653                         if (needcolon || i == 0)
 654                                 *p++ = ':';
 655                         *p++ = ':';
 656                         needcolon = false;
 657                         i += longest - 1;
 658                         continue;
 659                 }
 660                 if (needcolon) {
 661                         *p++ = ':';
 662                         needcolon = false;
 663                 }
 664                 /* hex u16 without leading 0s */
 665                 word = ntohs(in6.s6_addr16[i]);
 666                 hi = word >> 8;
 667                 lo = word & 0xff;
 668                 if (hi) {
 669                         if (hi > 0x0f)
 670                                 p = hex_byte_pack(p, hi);
 671                         else
 672                                 *p++ = hex_asc_lo(hi);
 673                         p = hex_byte_pack(p, lo);
 674                 }
 675                 else if (lo > 0x0f)
 676                         p = hex_byte_pack(p, lo);
 677                 else
 678                         *p++ = hex_asc_lo(lo);
 679                 needcolon = true;
 680         }
 681
 682         if (useIPv4) {
 683                 if (needcolon)
 684                         *p++ = ':';
 685                 p = ip4_string(p, &in6.s6_addr[12], "I4");
 686         }
 687         *p = '\0';
 688
 689         return p;
 690 }
 691
 692 static noinline_for_stack
 693 char *ip6_string(char *p, const char *addr, const char *fmt)
 694 {
 695         int i;
 696
 697         for (i = 0; i < 8; i++) {
 698                 p = hex_byte_pack(p, *addr++);
 699                 p = hex_byte_pack(p, *addr++);
 700                 if (fmt[0] == 'I' && i != 7)
 701                         *p++ = ':';
 702         }
 703         *p = '\0';
 704
 705         return p;
 706 }
 707
 708 static noinline_for_stack
 709 char *ip6_addr_string(char *buf, char *end, const u8 *addr,
 710                       struct printf_spec spec, const char *fmt)
 711 {
 712         char ip6_addr[sizeof("xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255")];
 713
 714         if (fmt[0] == 'I' && fmt[2] == 'c')
 715                 ip6_compressed_string(ip6_addr, addr);
 716         else
 717                 ip6_string(ip6_addr, addr, fmt);
 718
 719         return string(buf, end, ip6_addr, spec);
 720 }
 721
 722 static noinline_for_stack
 723 char *ip4_addr_string(char *buf, char *end, const u8 *addr,
 724                       struct printf_spec spec, const char *fmt)
 725 {
 726         char ip4_addr[sizeof("255.255.255.255")];
 727
 728         ip4_string(ip4_addr, addr, fmt);
 729
 730         return string(buf, end, ip4_addr, spec);
 731 }
 732
 733 static noinline_for_stack
 734 char *uuid_string(char *buf, char *end, const u8 *addr,
 735                   struct printf_spec spec, const char *fmt)
 736 {
 737         char uuid[sizeof("xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx")];
 738         char *p = uuid;
 739         int i;
 740         static const u8 be[16] = {0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15};
 741         static const u8 le[16] = {3,2,1,0,5,4,7,6,8,9,10,11,12,13,14,15};
 742         const u8 *index = be;
 743         bool uc = false;
 744
 745         switch (*(++fmt)) {
 746         case 'L':
 747                 uc = true;              /* fall-through */
 748         case 'l':
 749                 index = le;
 750                 break;
 751         case 'B':
 752                 uc = true;
 753                 break;
 754         }
 755
 756         for (i = 0; i < 16; i++) {
 757                 p = hex_byte_pack(p, addr[index[i]]);
 758                 switch (i) {
 759                 case 3:
 760                 case 5:
 761                 case 7:
 762                 case 9:
 763                         *p++ = '-';
 764                         break;
 765                 }
 766         }
 767
 768         *p = 0;
 769
 770         if (uc) {
 771                 p = uuid;
 772                 do {
 773                         *p = toupper(*p);
 774                 } while (*(++p));
 775         }
 776
 777         return string(buf, end, uuid, spec);
 778 }
 779
 780 int kptr_restrict __read_mostly;
 781
 782 /*
 783  * Show a '%p' thing.  A kernel extension is that the '%p' is followed
 784  * by an extra set of alphanumeric characters that are extended format
 785  * specifiers.
 786  *
 787  * Right now we handle:
 788  *
 789  * - 'F' For symbolic function descriptor pointers with offset
 790  * - 'f' For simple symbolic function names without offset
 791  * - 'S' For symbolic direct pointers with offset
 792  * - 's' For symbolic direct pointers without offset
 793  * - 'B' For backtraced symbolic direct pointers with offset
 794  * - 'R' For decoded struct resource, e.g., [mem 0x0-0x1f 64bit pref]
 795  * - 'r' For raw struct resource, e.g., [mem 0x0-0x1f flags 0x201]
 796  * - 'M' For a 6-byte MAC address, it prints the address in the
 797  *       usual colon-separated hex notation
 798  * - 'm' For a 6-byte MAC address, it prints the hex address without colons
 799  * - 'MF' For a 6-byte MAC FDDI address, it prints the address
 800  *       with a dash-separated hex notation
 801  * - 'I' [46] for IPv4/IPv6 addresses printed in the usual way
 802  *       IPv4 uses dot-separated decimal without leading 0's (1.2.3.4)
 803  *       IPv6 uses colon separated network-order 16 bit hex with leading 0's
 804  * - 'i' [46] for 'raw' IPv4/IPv6 addresses
 805  *       IPv6 omits the colons (01020304...0f)
 806  *       IPv4 uses dot-separated decimal with leading 0's (010.123.045.006)
 807  * - '[Ii]4[hnbl]' IPv4 addresses in host, network, big or little endian order
 808  * - 'I6c' for IPv6 addresses printed as specified by
 809  *       http://tools.ietf.org/html/rfc5952
 810  * - 'U' For a 16 byte UUID/GUID, it prints the UUID/GUID in the form
 811  *       "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx"
 812  *       Options for %pU are:
 813  *         b big endian lower case hex (default)
 814  *         B big endian UPPER case hex
 815  *         l little endian lower case hex
 816  *         L little endian UPPER case hex
 817  *           big endian output byte order is:
 818  *             [0][1][2][3]-[4][5]-[6][7]-[8][9]-[10][11][12][13][14][15]
 819  *           little endian output byte order is:
 820  *             [3][2][1][0]-[5][4]-[7][6]-[8][9]-[10][11][12][13][14][15]
 821  * - 'V' For a struct va_format which contains a format string * and va_list *,
 822  *       call vsnprintf(->format, *->va_list).
 823  *       Implements a "recursive vsnprintf".
 824  *       Do not use this feature without some mechanism to verify the
 825  *       correctness of the format string and va_list arguments.
 826  * - 'K' For a kernel pointer that should be hidden from unprivileged users
 827  *
 828  * Note: The difference between 'S' and 'F' is that on ia64 and ppc64
 829  * function pointers are really function descriptors, which contain a
 830  * pointer to the real address.
 831  */
 832 static noinline_for_stack
 833 char *pointer(const char *fmt, char *buf, char *end, void *ptr,
 834               struct printf_spec spec)
 835 {
 836         if (!ptr && *fmt != 'K') {
 837                 /*
 838                  * Print (null) with the same width as a pointer so it makes
 839                  * tabular output look nice.
 840                  */
 841                 if (spec.field_width == -1)
 842                         spec.field_width = 2 * sizeof(void *);
 843                 return string(buf, end, "(null)", spec);
 844         }
 845
 846         switch (*fmt) {
 847         case 'F':
 848         case 'f':
 849                 ptr = dereference_function_descriptor(ptr);
 850                 /* Fallthrough */
 851         case 'S':
 852         case 's':
 853         case 'B':
 854                 return symbol_string(buf, end, ptr, spec, *fmt);
 855         case 'R':
 856         case 'r':
 857                 return resource_string(buf, end, ptr, spec, fmt);
 858         case 'M':                       /* Colon separated: 00:01:02:03:04:05 */
 859         case 'm':                       /* Contiguous: 000102030405 */
 860                                         /* [mM]F (FDDI, bit reversed) */
 861                 return mac_address_string(buf, end, ptr, spec, fmt);
 862         case 'I':                       /* Formatted IP supported
 863                                          * 4:   1.2.3.4
 864                                          * 6:   0001:0203:...:0708
 865                                          * 6c:  1::708 or 1::1.2.3.4
 866                                          */
 867         case 'i':                       /* Contiguous:
 868                                          * 4:   001.002.003.004
 869                                          * 6:   000102...0f
 870                                          */
 871                 switch (fmt[1]) {
 872                 case '6':
 873                         return ip6_addr_string(buf, end, ptr, spec, fmt);
 874                 case '4':
 875                         return ip4_addr_string(buf, end, ptr, spec, fmt);
 876                 }
 877                 break;
 878         case 'U':
 879                 return uuid_string(buf, end, ptr, spec, fmt);
 880         case 'V':
 881                 return buf + vsnprintf(buf, end > buf ? end - buf : 0,
 882                                        ((struct va_format *)ptr)->fmt,
 883                                        *(((struct va_format *)ptr)->va));
 884         case 'K':
 885                 /*
 886                  * %pK cannot be used in IRQ context because its test
 887                  * for CAP_SYSLOG would be meaningless.
 888                  */
 889                 if (in_irq() || in_serving_softirq() || in_nmi()) {
 890                         if (spec.field_width == -1)
 891                                 spec.field_width = 2 * sizeof(void *);
 892                         return string(buf, end, "pK-error", spec);
 893                 }
 894                 if (!((kptr_restrict == 0) ||
 895                       (kptr_restrict == 1 &&
 896                        has_capability_noaudit(current, CAP_SYSLOG))))
 897                         ptr = NULL;
 898                 break;
 899         }
 900         spec.flags |= SMALL;
 901         if (spec.field_width == -1) {
 902                 spec.field_width = 2 * sizeof(void *);
 903                 spec.flags |= ZEROPAD;
 904         }
 905         spec.base = 16;
 906
 907         return number(buf, end, (unsigned long) ptr, spec);
 908 }
 909
 910 /*
 911  * Helper function to decode printf style format.
 912  * Each call decode a token from the format and return the
 913  * number of characters read (or likely the delta where it wants
 914  * to go on the next call).
 915  * The decoded token is returned through the parameters
 916  *
 917  * 'h', 'l', or 'L' for integer fields
 918  * 'z' support added 23/7/1999 S.H.
 919  * 'z' changed to 'Z' --davidm 1/25/99
 920  * 't' added for ptrdiff_t
 921  *
 922  * @fmt: the format string
 923  * @type of the token returned
 924  * @flags: various flags such as +, -, # tokens..
 925  * @field_width: overwritten width
 926  * @base: base of the number (octal, hex, ...)
 927  * @precision: precision of a number
 928  * @qualifier: qualifier of a number (long, size_t, ...)
 929  */
 930 static noinline_for_stack
 931 int format_decode(const char *fmt, struct printf_spec *spec)
 932 {
 933         const char *start = fmt;
 934
 935         /* we finished early by reading the field width */
 936         if (spec->type == FORMAT_TYPE_WIDTH) {
 937                 if (spec->field_width < 0) {
 938                         spec->field_width = -spec->field_width;
 939                         spec->flags |= LEFT;
 940                 }
 941                 spec->type = FORMAT_TYPE_NONE;
 942                 goto precision;
 943         }
 944
 945         /* we finished early by reading the precision */
 946         if (spec->type == FORMAT_TYPE_PRECISION) {
 947                 if (spec->precision < 0)
 948                         spec->precision = 0;
 949
 950                 spec->type = FORMAT_TYPE_NONE;
 951                 goto qualifier;
 952         }
 953
 954         /* By default */
 955         spec->type = FORMAT_TYPE_NONE;
 956
 957         for (; *fmt ; ++fmt) {
 958                 if (*fmt == '%')
 959                         break;
 960         }
 961
 962         /* Return the current non-format string */
 963         if (fmt != start || !*fmt)
 964                 return fmt - start;
 965
 966         /* Process flags */
 967         spec->flags = 0;
 968
 969         while (1) { /* this also skips first '%' */
 970                 bool found = true;
 971
 972                 ++fmt;
 973
 974                 switch (*fmt) {
 975                 case '-': spec->flags |= LEFT;    break;
 976                 case '+': spec->flags |= PLUS;    break;
 977                 case ' ': spec->flags |= SPACE;   break;
 978                 case '#': spec->flags |= SPECIAL; break;
 979                 case '0': spec->flags |= ZEROPAD; break;
 980                 default:  found = false;
 981                 }
 982
 983                 if (!found)
 984                         break;
 985         }
 986
 987         /* get field width */
 988         spec->field_width = -1;
 989
 990         if (isdigit(*fmt))
 991                 spec->field_width = skip_atoi(&fmt);
 992         else if (*fmt == '*') {
 993                 /* it's the next argument */
 994                 spec->type = FORMAT_TYPE_WIDTH;
 995                 return ++fmt - start;
 996         }
 997
 998 precision:
 999         /* get the precision */
1000         spec->precision = -1;
1001         if (*fmt == '.') {
1002                 ++fmt;
1003                 if (isdigit(*fmt)) {
1004                         spec->precision = skip_atoi(&fmt);
1005                         if (spec->precision < 0)
1006                                 spec->precision = 0;
1007                 } else if (*fmt == '*') {
1008                         /* it's the next argument */
1009                         spec->type = FORMAT_TYPE_PRECISION;
1010                         return ++fmt - start;
1011                 }
1012         }
1013
1014 qualifier:
1015         /* get the conversion qualifier */
1016         spec->qualifier = -1;
1017         if (*fmt == 'h' || _tolower(*fmt) == 'l' ||
1018             _tolower(*fmt) == 'z' || *fmt == 't') {
1019                 spec->qualifier = *fmt++;
1020                 if (unlikely(spec->qualifier == *fmt)) {
1021                         if (spec->qualifier == 'l') {
1022                                 spec->qualifier = 'L';
1023                                 ++fmt;
1024                         } else if (spec->qualifier == 'h') {
1025                                 spec->qualifier = 'H';
1026                                 ++fmt;
1027                         }
1028                 }
1029         }
1030
1031         /* default base */
1032         spec->base = 10;
1033         switch (*fmt) {
1034         case 'c':
1035                 spec->type = FORMAT_TYPE_CHAR;
1036                 return ++fmt - start;
1037
1038         case 's':
1039                 spec->type = FORMAT_TYPE_STR;
1040                 return ++fmt - start;
1041
1042         case 'p':
1043                 spec->type = FORMAT_TYPE_PTR;
1044                 return fmt - start;
1045                 /* skip alnum */
1046
1047         case 'n':
1048                 spec->type = FORMAT_TYPE_NRCHARS;
1049                 return ++fmt - start;
1050
1051         case '%':
1052                 spec->type = FORMAT_TYPE_PERCENT_CHAR;
1053                 return ++fmt - start;
1054
1055         /* integer number formats - set up the flags and "break" */
1056         case 'o':
1057                 spec->base = 8;
1058                 break;
1059
1060         case 'x':
1061                 spec->flags |= SMALL;
1062
1063         case 'X':
1064                 spec->base = 16;
1065                 break;
1066
1067         case 'd':
1068         case 'i':
1069                 spec->flags |= SIGN;
1070         case 'u':
1071                 break;
1072
1073         default:
1074                 spec->type = FORMAT_TYPE_INVALID;
1075                 return fmt - start;
1076         }
1077
1078         if (spec->qualifier == 'L')
1079                 spec->type = FORMAT_TYPE_LONG_LONG;
1080         else if (spec->qualifier == 'l') {
1081                 if (spec->flags & SIGN)
1082                         spec->type = FORMAT_TYPE_LONG;
1083                 else
1084                         spec->type = FORMAT_TYPE_ULONG;
1085         } else if (_tolower(spec->qualifier) == 'z') {
1086                 spec->type = FORMAT_TYPE_SIZE_T;
1087         } else if (spec->qualifier == 't') {
1088                 spec->type = FORMAT_TYPE_PTRDIFF;
1089         } else if (spec->qualifier == 'H') {
1090                 if (spec->flags & SIGN)
1091                         spec->type = FORMAT_TYPE_BYTE;
1092                 else
1093                         spec->type = FORMAT_TYPE_UBYTE;
1094         } else if (spec->qualifier == 'h') {
1095                 if (spec->flags & SIGN)
1096                         spec->type = FORMAT_TYPE_SHORT;
1097                 else
1098                         spec->type = FORMAT_TYPE_USHORT;
1099         } else {
1100                 if (spec->flags & SIGN)
1101                         spec->type = FORMAT_TYPE_INT;
1102                 else
1103                         spec->type = FORMAT_TYPE_UINT;
1104         }
1105
1106         return ++fmt - start;
1107 }
1108
1109 /**
1110  * vsnprintf - Format a string and place it in a buffer
1111  * @buf: The buffer to place the result into
1112  * @size: The size of the buffer, including the trailing null space
1113  * @fmt: The format string to use
1114  * @args: Arguments for the format string
1115  *
1116  * This function follows C99 vsnprintf, but has some extensions:
1117  * %pS output the name of a text symbol with offset
1118  * %ps output the name of a text symbol without offset
1119  * %pF output the name of a function pointer with its offset
1120  * %pf output the name of a function pointer without its offset
1121  * %pB output the name of a backtrace symbol with its offset
1122  * %pR output the address range in a struct resource with decoded flags
1123  * %pr output the address range in a struct resource with raw flags
1124  * %pM output a 6-byte MAC address with colons
1125  * %pm output a 6-byte MAC address without colons
1126  * %pI4 print an IPv4 address without leading zeros
1127  * %pi4 print an IPv4 address with leading zeros
1128  * %pI6 print an IPv6 address with colons
1129  * %pi6 print an IPv6 address without colons
1130  * %pI6c print an IPv6 address as specified by RFC 5952
1131  * %pU[bBlL] print a UUID/GUID in big or little endian using lower or upper
1132  *   case.
1133  * %n is ignored
1134  *
1135  * The return value is the number of characters which would
1136  * be generated for the given input, excluding the trailing
1137  * '\0', as per ISO C99. If you want to have the exact
1138  * number of characters written into @buf as return value
1139  * (not including the trailing '\0'), use vscnprintf(). If the
1140  * return is greater than or equal to @size, the resulting
1141  * string is truncated.
1142  *
1143  * If you're not already dealing with a va_list consider using snprintf().
1144  */
1145 int vsnprintf(char *buf, size_t size, const char *fmt, va_list args)
1146 {
1147         unsigned long long num;
1148         char *str, *end;
1149         struct printf_spec spec = {0};
1150
1151         /* Reject out-of-range values early.  Large positive sizes are
1152            used for unknown buffer sizes. */
1153         if (WARN_ON_ONCE((int) size < 0))
1154                 return 0;
1155
1156         str = buf;
1157         end = buf + size;
1158
1159         /* Make sure end is always >= buf */
1160         if (end < buf) {
1161                 end = ((void *)-1);
1162                 size = end - buf;
1163         }
1164
1165         while (*fmt) {
1166                 const char *old_fmt = fmt;
1167                 int read = format_decode(fmt, &spec);
1168
1169                 fmt += read;
1170
1171                 switch (spec.type) {
1172                 case FORMAT_TYPE_NONE: {
1173                         int copy = read;
1174                         if (str < end) {
1175                                 if (copy > end - str)
1176                                         copy = end - str;
1177                                 memcpy(str, old_fmt, copy);
1178                         }
1179                         str += read;
1180                         break;
1181                 }
1182
1183                 case FORMAT_TYPE_WIDTH:
1184                         spec.field_width = va_arg(args, int);
1185                         break;
1186
1187                 case FORMAT_TYPE_PRECISION:
1188                         spec.precision = va_arg(args, int);
1189                         break;
1190
1191                 case FORMAT_TYPE_CHAR: {
1192                         char c;
1193
1194                         if (!(spec.flags & LEFT)) {
1195                                 while (--spec.field_width > 0) {
1196                                         if (str < end)
1197                                                 *str = ' ';
1198                                         ++str;
1199
1200                                 }
1201                         }
1202                         c = (unsigned char) va_arg(args, int);
1203                         if (str < end)
1204                                 *str = c;
1205                         ++str;
1206                         while (--spec.field_width > 0) {
1207                                 if (str < end)
1208                                         *str = ' ';
1209                                 ++str;
1210                         }
1211                         break;
1212                 }
1213
1214                 case FORMAT_TYPE_STR:
1215                         str = string(str, end, va_arg(args, char *), spec);
1216                         break;
1217
1218                 case FORMAT_TYPE_PTR:
1219                         str = pointer(fmt+1, str, end, va_arg(args, void *),
1220                                       spec);
1221                         while (isalnum(*fmt))
1222                                 fmt++;
1223                         break;
1224
1225                 case FORMAT_TYPE_PERCENT_CHAR:
1226                         if (str < end)
1227                                 *str = '%';
1228                         ++str;
1229                         break;
1230
1231                 case FORMAT_TYPE_INVALID:
1232                         if (str < end)
1233                                 *str = '%';
1234                         ++str;
1235                         break;
1236
1237                 case FORMAT_TYPE_NRCHARS: {
1238                         u8 qualifier = spec.qualifier;
1239
1240                         if (qualifier == 'l') {
1241                                 long *ip = va_arg(args, long *);
1242                                 *ip = (str - buf);
1243                         } else if (_tolower(qualifier) == 'z') {
1244                                 size_t *ip = va_arg(args, size_t *);
1245                                 *ip = (str - buf);
1246                         } else {
1247                                 int *ip = va_arg(args, int *);
1248                                 *ip = (str - buf);
1249                         }
1250                         break;
1251                 }
1252
1253                 default:
1254                         switch (spec.type) {
1255                         case FORMAT_TYPE_LONG_LONG:
1256                                 num = va_arg(args, long long);
1257                                 break;
1258                         case FORMAT_TYPE_ULONG:
1259                                 num = va_arg(args, unsigned long);
1260                                 break;
1261                         case FORMAT_TYPE_LONG:
1262                                 num = va_arg(args, long);
1263                                 break;
1264                         case FORMAT_TYPE_SIZE_T:
1265                                 num = va_arg(args, size_t);
1266                                 break;
1267                         case FORMAT_TYPE_PTRDIFF:
1268                                 num = va_arg(args, ptrdiff_t);
1269                                 break;
1270                         case FORMAT_TYPE_UBYTE:
1271                                 num = (unsigned char) va_arg(args, int);
1272                                 break;
1273                         case FORMAT_TYPE_BYTE:
1274                                 num = (signed char) va_arg(args, int);
1275                                 break;
1276                         case FORMAT_TYPE_USHORT:
1277                                 num = (unsigned short) va_arg(args, int);
1278                                 break;
1279                         case FORMAT_TYPE_SHORT:
1280                                 num = (short) va_arg(args, int);
1281                                 break;
1282                         case FORMAT_TYPE_INT:
1283                                 num = (int) va_arg(args, int);
1284                                 break;
1285                         default:
1286                                 num = va_arg(args, unsigned int);
1287                         }
1288
1289                         str = number(str, end, num, spec);
1290                 }
1291         }
1292
1293         if (size > 0) {
1294                 if (str < end)
1295                         *str = '\0';
1296                 else
1297                         end[-1] = '\0';
1298         }
1299
1300         /* the trailing null byte doesn't count towards the total */
1301         return str-buf;
1302
1303 }
1304 EXPORT_SYMBOL(vsnprintf);
1305
1306 /**
1307  * vscnprintf - Format a string and place it in a buffer
1308  * @buf: The buffer to place the result into
1309  * @size: The size of the buffer, including the trailing null space
1310  * @fmt: The format string to use
1311  * @args: Arguments for the format string
1312  *
1313  * The return value is the number of characters which have been written into
1314  * the @buf not including the trailing '\0'. If @size is == 0 the function
1315  * returns 0.
1316  *
1317  * If you're not already dealing with a va_list consider using scnprintf().
1318  *
1319  * See the vsnprintf() documentation for format string extensions over C99.
1320  */
1321 int vscnprintf(char *buf, size_t size, const char *fmt, va_list args)
1322 {
1323         int i;
1324
1325         i = vsnprintf(buf, size, fmt, args);
1326
1327         if (likely(i < size))
1328                 return i;
1329         if (size != 0)
1330                 return size - 1;
1331         return 0;
1332 }
1333 EXPORT_SYMBOL(vscnprintf);
1334
1335 /**
1336  * snprintf - Format a string and place it in a buffer
1337  * @buf: The buffer to place the result into
1338  * @size: The size of the buffer, including the trailing null space
1339  * @fmt: The format string to use
1340  * @...: Arguments for the format string
1341  *
1342  * The return value is the number of characters which would be
1343  * generated for the given input, excluding the trailing null,
1344  * as per ISO C99.  If the return is greater than or equal to
1345  * @size, the resulting string is truncated.
1346  *
1347  * See the vsnprintf() documentation for format string extensions over C99.
1348  */
1349 int snprintf(char *buf, size_t size, const char *fmt, ...)
1350 {
1351         va_list args;
1352         int i;
1353
1354         va_start(args, fmt);
1355         i = vsnprintf(buf, size, fmt, args);
1356         va_end(args);
1357
1358         return i;
1359 }
1360 EXPORT_SYMBOL(snprintf);
1361
1362 /**
1363  * scnprintf - Format a string and place it in a buffer
1364  * @buf: The buffer to place the result into
1365  * @size: The size of the buffer, including the trailing null space
1366  * @fmt: The format string to use
1367  * @...: Arguments for the format string
1368  *
1369  * The return value is the number of characters written into @buf not including
1370  * the trailing '\0'. If @size is == 0 the function returns 0.
1371  */
1372
1373 int scnprintf(char *buf, size_t size, const char *fmt, ...)
1374 {
1375         va_list args;
1376         int i;
1377
1378         va_start(args, fmt);
1379         i = vscnprintf(buf, size, fmt, args);
1380         va_end(args);
1381
1382         return i;
1383 }
1384 EXPORT_SYMBOL(scnprintf);
1385
1386 /**
1387  * vsprintf - Format a string and place it in a buffer
1388  * @buf: The buffer to place the result into
1389  * @fmt: The format string to use
1390  * @args: Arguments for the format string
1391  *
1392  * The function returns the number of characters written
1393  * into @buf. Use vsnprintf() or vscnprintf() in order to avoid
1394  * buffer overflows.
1395  *
1396  * If you're not already dealing with a va_list consider using sprintf().
1397  *
1398  * See the vsnprintf() documentation for format string extensions over C99.
1399  */
1400 int vsprintf(char *buf, const char *fmt, va_list args)
1401 {
1402         return vsnprintf(buf, INT_MAX, fmt, args);
1403 }
1404 EXPORT_SYMBOL(vsprintf);
1405
1406 /**
1407  * sprintf - Format a string and place it in a buffer
1408  * @buf: The buffer to place the result into
1409  * @fmt: The format string to use
1410  * @...: Arguments for the format string
1411  *
1412  * The function returns the number of characters written
1413  * into @buf. Use snprintf() or scnprintf() in order to avoid
1414  * buffer overflows.
1415  *
1416  * See the vsnprintf() documentation for format string extensions over C99.
1417  */
1418 int sprintf(char *buf, const char *fmt, ...)
1419 {
1420         va_list args;
1421         int i;
1422
1423         va_start(args, fmt);
1424         i = vsnprintf(buf, INT_MAX, fmt, args);
1425         va_end(args);
1426
1427         return i;
1428 }
1429 EXPORT_SYMBOL(sprintf);
1430
1431 #ifdef CONFIG_BINARY_PRINTF
1432 /*
1433  * bprintf service:
1434  * vbin_printf() - VA arguments to binary data
1435  * bstr_printf() - Binary data to text string
1436  */
1437
1438 /**
1439  * vbin_printf - Parse a format string and place args' binary value in a buffer
1440  * @bin_buf: The buffer to place args' binary value
1441  * @size: The size of the buffer(by words(32bits), not characters)
1442  * @fmt: The format string to use
1443  * @args: Arguments for the format string
1444  *
1445  * The format follows C99 vsnprintf, except %n is ignored, and its argument
1446  * is skiped.
1447  *
1448  * The return value is the number of words(32bits) which would be generated for
1449  * the given input.
1450  *
1451  * NOTE:
1452  * If the return value is greater than @size, the resulting bin_buf is NOT
1453  * valid for bstr_printf().
1454  */
1455 int vbin_printf(u32 *bin_buf, size_t size, const char *fmt, va_list args)
1456 {
1457         struct printf_spec spec = {0};
1458         char *str, *end;
1459
1460         str = (char *)bin_buf;
1461         end = (char *)(bin_buf + size);
1462
1463 #define save_arg(type)                                                  \
1464 do {                                                                    \
1465         if (sizeof(type) == 8) {                                        \
1466                 unsigned long long value;                               \
1467                 str = PTR_ALIGN(str, sizeof(u32));                      \
1468                 value = va_arg(args, unsigned long long);               \
1469                 if (str + sizeof(type) <= end) {                        \
1470                         *(u32 *)str = *(u32 *)&value;                   \
1471                         *(u32 *)(str + 4) = *((u32 *)&value + 1);       \
1472                 }                                                       \
1473         } else {                                                        \
1474                 unsigned long value;                                    \
1475                 str = PTR_ALIGN(str, sizeof(type));                     \
1476                 value = va_arg(args, int);                              \
1477                 if (str + sizeof(type) <= end)                          \
1478                         *(typeof(type) *)str = (type)value;             \
1479         }                                                               \
1480         str += sizeof(type);                                            \
1481 } while (0)
1482
1483         while (*fmt) {
1484                 int read = format_decode(fmt, &spec);
1485
1486                 fmt += read;
1487
1488                 switch (spec.type) {
1489                 case FORMAT_TYPE_NONE:
1490                 case FORMAT_TYPE_INVALID:
1491                 case FORMAT_TYPE_PERCENT_CHAR:
1492                         break;
1493
1494                 case FORMAT_TYPE_WIDTH:
1495                 case FORMAT_TYPE_PRECISION:
1496                         save_arg(int);
1497                         break;
1498
1499                 case FORMAT_TYPE_CHAR:
1500                         save_arg(char);
1501                         break;
1502
1503                 case FORMAT_TYPE_STR: {
1504                         const char *save_str = va_arg(args, char *);
1505                         size_t len;
1506
1507                         if ((unsigned long)save_str > (unsigned long)-PAGE_SIZE
1508                                         || (unsigned long)save_str < PAGE_SIZE)
1509                                 save_str = "(null)";
1510                         len = strlen(save_str) + 1;
1511                         if (str + len < end)
1512                                 memcpy(str, save_str, len);
1513                         str += len;
1514                         break;
1515                 }
1516
1517                 case FORMAT_TYPE_PTR:
1518                         save_arg(void *);
1519                         /* skip all alphanumeric pointer suffixes */
1520                         while (isalnum(*fmt))
1521                                 fmt++;
1522                         break;
1523
1524                 case FORMAT_TYPE_NRCHARS: {
1525                         /* skip %n 's argument */
1526                         u8 qualifier = spec.qualifier;
1527                         void *skip_arg;
1528                         if (qualifier == 'l')
1529                                 skip_arg = va_arg(args, long *);
1530                         else if (_tolower(qualifier) == 'z')
1531                                 skip_arg = va_arg(args, size_t *);
1532                         else
1533                                 skip_arg = va_arg(args, int *);
1534                         break;
1535                 }
1536
1537                 default:
1538                         switch (spec.type) {
1539
1540                         case FORMAT_TYPE_LONG_LONG:
1541                                 save_arg(long long);
1542                                 break;
1543                         case FORMAT_TYPE_ULONG:
1544                         case FORMAT_TYPE_LONG:
1545                                 save_arg(unsigned long);
1546                                 break;
1547                         case FORMAT_TYPE_SIZE_T:
1548                                 save_arg(size_t);
1549                                 break;
1550                         case FORMAT_TYPE_PTRDIFF:
1551                                 save_arg(ptrdiff_t);
1552                                 break;
1553                         case FORMAT_TYPE_UBYTE:
1554                         case FORMAT_TYPE_BYTE:
1555                                 save_arg(char);
1556                                 break;
1557                         case FORMAT_TYPE_USHORT:
1558                         case FORMAT_TYPE_SHORT:
1559                                 save_arg(short);
1560                                 break;
1561                         default:
1562                                 save_arg(int);
1563                         }
1564                 }
1565         }
1566
1567         return (u32 *)(PTR_ALIGN(str, sizeof(u32))) - bin_buf;
1568 #undef save_arg
1569 }
1570 EXPORT_SYMBOL_GPL(vbin_printf);
1571
1572 /**
1573  * bstr_printf - Format a string from binary arguments and place it in a buffer
1574  * @buf: The buffer to place the result into
1575  * @size: The size of the buffer, including the trailing null space
1576  * @fmt: The format string to use
1577  * @bin_buf: Binary arguments for the format string
1578  *
1579  * This function like C99 vsnprintf, but the difference is that vsnprintf gets
1580  * arguments from stack, and bstr_printf gets arguments from @bin_buf which is
1581  * a binary buffer that generated by vbin_printf.
1582  *
1583  * The format follows C99 vsnprintf, but has some extensions:
1584  *  see vsnprintf comment for details.
1585  *
1586  * The return value is the number of characters which would
1587  * be generated for the given input, excluding the trailing
1588  * '\0', as per ISO C99. If you want to have the exact
1589  * number of characters written into @buf as return value
1590  * (not including the trailing '\0'), use vscnprintf(). If the
1591  * return is greater than or equal to @size, the resulting
1592  * string is truncated.
1593  */
1594 int bstr_printf(char *buf, size_t size, const char *fmt, const u32 *bin_buf)
1595 {
1596         struct printf_spec spec = {0};
1597         char *str, *end;
1598         const char *args = (const char *)bin_buf;
1599
1600         if (WARN_ON_ONCE((int) size < 0))
1601                 return 0;
1602
1603         str = buf;
1604         end = buf + size;
1605
1606 #define get_arg(type)                                                   \
1607 ({                                                                      \
1608         typeof(type) value;                                             \
1609         if (sizeof(type) == 8) {                                        \
1610                 args = PTR_ALIGN(args, sizeof(u32));                    \
1611                 *(u32 *)&value = *(u32 *)args;                          \
1612                 *((u32 *)&value + 1) = *(u32 *)(args + 4);              \
1613         } else {                                                        \
1614                 args = PTR_ALIGN(args, sizeof(type));                   \
1615                 value = *(typeof(type) *)args;                          \
1616         }                                                               \
1617         args += sizeof(type);                                           \
1618         value;                                                          \
1619 })
1620
1621         /* Make sure end is always >= buf */
1622         if (end < buf) {
1623                 end = ((void *)-1);
1624                 size = end - buf;
1625         }
1626
1627         while (*fmt) {
1628                 const char *old_fmt = fmt;
1629                 int read = format_decode(fmt, &spec);
1630
1631                 fmt += read;
1632
1633                 switch (spec.type) {
1634                 case FORMAT_TYPE_NONE: {
1635                         int copy = read;
1636                         if (str < end) {
1637                                 if (copy > end - str)
1638                                         copy = end - str;
1639                                 memcpy(str, old_fmt, copy);
1640                         }
1641                         str += read;
1642                         break;
1643                 }
1644
1645                 case FORMAT_TYPE_WIDTH:
1646                         spec.field_width = get_arg(int);
1647                         break;
1648
1649                 case FORMAT_TYPE_PRECISION:
1650                         spec.precision = get_arg(int);
1651                         break;
1652
1653                 case FORMAT_TYPE_CHAR: {
1654                         char c;
1655
1656                         if (!(spec.flags & LEFT)) {
1657                                 while (--spec.field_width > 0) {
1658                                         if (str < end)
1659                                                 *str = ' ';
1660                                         ++str;
1661                                 }
1662                         }
1663                         c = (unsigned char) get_arg(char);
1664                         if (str < end)
1665                                 *str = c;
1666                         ++str;
1667                         while (--spec.field_width > 0) {
1668                                 if (str < end)
1669                                         *str = ' ';
1670                                 ++str;
1671                         }
1672                         break;
1673                 }
1674
1675                 case FORMAT_TYPE_STR: {
1676                         const char *str_arg = args;
1677                         args += strlen(str_arg) + 1;
1678                         str = string(str, end, (char *)str_arg, spec);
1679                         break;
1680                 }
1681
1682                 case FORMAT_TYPE_PTR:
1683                         str = pointer(fmt+1, str, end, get_arg(void *), spec);
1684                         while (isalnum(*fmt))
1685                                 fmt++;
1686                         break;
1687
1688                 case FORMAT_TYPE_PERCENT_CHAR:
1689                 case FORMAT_TYPE_INVALID:
1690                         if (str < end)
1691                                 *str = '%';
1692                         ++str;
1693                         break;
1694
1695                 case FORMAT_TYPE_NRCHARS:
1696                         /* skip */
1697                         break;
1698
1699                 default: {
1700                         unsigned long long num;
1701
1702                         switch (spec.type) {
1703
1704                         case FORMAT_TYPE_LONG_LONG:
1705                                 num = get_arg(long long);
1706                                 break;
1707                         case FORMAT_TYPE_ULONG:
1708                         case FORMAT_TYPE_LONG:
1709                                 num = get_arg(unsigned long);
1710                                 break;
1711                         case FORMAT_TYPE_SIZE_T:
1712                                 num = get_arg(size_t);
1713                                 break;
1714                         case FORMAT_TYPE_PTRDIFF:
1715                                 num = get_arg(ptrdiff_t);
1716                                 break;
1717                         case FORMAT_TYPE_UBYTE:
1718                                 num = get_arg(unsigned char);
1719                                 break;
1720                         case FORMAT_TYPE_BYTE:
1721                                 num = get_arg(signed char);
1722                                 break;
1723                         case FORMAT_TYPE_USHORT:
1724                                 num = get_arg(unsigned short);
1725                                 break;
1726                         case FORMAT_TYPE_SHORT:
1727                                 num = get_arg(short);
1728                                 break;
1729                         case FORMAT_TYPE_UINT:
1730                                 num = get_arg(unsigned int);
1731                                 break;
1732                         default:
1733                                 num = get_arg(int);
1734                         }
1735
1736                         str = number(str, end, num, spec);
1737                 } /* default: */
1738                 } /* switch(spec.type) */
1739         } /* while(*fmt) */
1740
1741         if (size > 0) {
1742                 if (str < end)
1743                         *str = '\0';
1744                 else
1745                         end[-1] = '\0';
1746         }
1747
1748 #undef get_arg
1749
1750         /* the trailing null byte doesn't count towards the total */
1751         return str - buf;
1752 }
1753 EXPORT_SYMBOL_GPL(bstr_printf);
1754
1755 /**
1756  * bprintf - Parse a format string and place args' binary value in a buffer
1757  * @bin_buf: The buffer to place args' binary value
1758  * @size: The size of the buffer(by words(32bits), not characters)
1759  * @fmt: The format string to use
1760  * @...: Arguments for the format string
1761  *
1762  * The function returns the number of words(u32) written
1763  * into @bin_buf.
1764  */
1765 int bprintf(u32 *bin_buf, size_t size, const char *fmt, ...)
1766 {
1767         va_list args;
1768         int ret;
1769
1770         va_start(args, fmt);
1771         ret = vbin_printf(bin_buf, size, fmt, args);
1772         va_end(args);
1773
1774         return ret;
1775 }
1776 EXPORT_SYMBOL_GPL(bprintf);
1777
1778 #endif /* CONFIG_BINARY_PRINTF */
1779
1780 /**
1781  * vsscanf - Unformat a buffer into a list of arguments
1782  * @buf:        input buffer
1783  * @fmt:        format of buffer
1784  * @args:       arguments
1785  */
1786 int vsscanf(const char *buf, const char *fmt, va_list args)
1787 {
1788         const char *str = buf;
1789         char *next;
1790         char digit;
1791         int num = 0;
1792         u8 qualifier;
1793         u8 base;
1794         s16 field_width;
1795         bool is_sign;
1796
1797         while (*fmt && *str) {
1798                 /* skip any white space in format */
1799                 /* white space in format matchs any amount of
1800                  * white space, including none, in the input.
1801                  */
1802                 if (isspace(*fmt)) {
1803                         fmt = skip_spaces(++fmt);
1804                         str = skip_spaces(str);
1805                 }
1806
1807                 /* anything that is not a conversion must match exactly */
1808                 if (*fmt != '%' && *fmt) {
1809                         if (*fmt++ != *str++)
1810                                 break;
1811                         continue;
1812                 }
1813
1814                 if (!*fmt)
1815                         break;
1816                 ++fmt;
1817
1818                 /* skip this conversion.
1819                  * advance both strings to next white space
1820                  */
1821                 if (*fmt == '*') {
1822                         while (!isspace(*fmt) && *fmt != '%' && *fmt)
1823                                 fmt++;
1824                         while (!isspace(*str) && *str)
1825                                 str++;
1826                         continue;
1827                 }
1828
1829                 /* get field width */
1830                 field_width = -1;
1831                 if (isdigit(*fmt))
1832                         field_width = skip_atoi(&fmt);
1833
1834                 /* get conversion qualifier */
1835                 qualifier = -1;
1836                 if (*fmt == 'h' || _tolower(*fmt) == 'l' ||
1837                     _tolower(*fmt) == 'z') {
1838                         qualifier = *fmt++;
1839                         if (unlikely(qualifier == *fmt)) {
1840                                 if (qualifier == 'h') {
1841                                         qualifier = 'H';
1842                                         fmt++;
1843                                 } else if (qualifier == 'l') {
1844                                         qualifier = 'L';
1845                                         fmt++;
1846                                 }
1847                         }
1848                 }
1849
1850                 if (!*fmt || !*str)
1851                         break;
1852
1853                 base = 10;
1854                 is_sign = 0;
1855
1856                 switch (*fmt++) {
1857                 case 'c':
1858                 {
1859                         char *s = (char *)va_arg(args, char*);
1860                         if (field_width == -1)
1861                                 field_width = 1;
1862                         do {
1863                                 *s++ = *str++;
1864                         } while (--field_width > 0 && *str);
1865                         num++;
1866                 }
1867                 continue;
1868                 case 's':
1869                 {
1870                         char *s = (char *)va_arg(args, char *);
1871                         if (field_width == -1)
1872                                 field_width = SHRT_MAX;
1873                         /* first, skip leading white space in buffer */
1874                         str = skip_spaces(str);
1875
1876                         /* now copy until next white space */
1877                         while (*str && !isspace(*str) && field_width--)
1878                                 *s++ = *str++;
1879                         *s = '\0';
1880                         num++;
1881                 }
1882                 continue;
1883                 case 'n':
1884                         /* return number of characters read so far */
1885                 {
1886                         int *i = (int *)va_arg(args, int*);
1887                         *i = str - buf;
1888                 }
1889                 continue;
1890                 case 'o':
1891                         base = 8;
1892                         break;
1893                 case 'x':
1894                 case 'X':
1895                         base = 16;
1896                         break;
1897                 case 'i':
1898                         base = 0;
1899                 case 'd':
1900                         is_sign = 1;
1901                 case 'u':
1902                         break;
1903                 case '%':
1904                         /* looking for '%' in str */
1905                         if (*str++ != '%')
1906                                 return num;
1907                         continue;
1908                 default:
1909                         /* invalid format; stop here */
1910                         return num;
1911                 }
1912
1913                 /* have some sort of integer conversion.
1914                  * first, skip white space in buffer.
1915                  */
1916                 str = skip_spaces(str);
1917
1918                 digit = *str;
1919                 if (is_sign && digit == '-')
1920                         digit = *(str + 1);
1921
1922                 if (!digit
1923                     || (base == 16 && !isxdigit(digit))
1924                     || (base == 10 && !isdigit(digit))
1925                     || (base == 8 && (!isdigit(digit) || digit > '7'))
1926                     || (base == 0 && !isdigit(digit)))
1927                         break;
1928
1929                 switch (qualifier) {
1930                 case 'H':       /* that's 'hh' in format */
1931                         if (is_sign) {
1932                                 signed char *s = (signed char *)va_arg(args, signed char *);
1933                                 *s = (signed char)simple_strtol(str, &next, base);
1934                         } else {
1935                                 unsigned char *s = (unsigned char *)va_arg(args, unsigned char *);
1936                                 *s = (unsigned char)simple_strtoul(str, &next, base);
1937                         }
1938                         break;
1939                 case 'h':
1940                         if (is_sign) {
1941                                 short *s = (short *)va_arg(args, short *);
1942                                 *s = (short)simple_strtol(str, &next, base);
1943                         } else {
1944                                 unsigned short *s = (unsigned short *)va_arg(args, unsigned short *);
1945                                 *s = (unsigned short)simple_strtoul(str, &next, base);
1946                         }
1947                         break;
1948                 case 'l':
1949                         if (is_sign) {
1950                                 long *l = (long *)va_arg(args, long *);
1951                                 *l = simple_strtol(str, &next, base);
1952                         } else {
1953                                 unsigned long *l = (unsigned long *)va_arg(args, unsigned long *);
1954                                 *l = simple_strtoul(str, &next, base);
1955                         }
1956                         break;
1957                 case 'L':
1958                         if (is_sign) {
1959                                 long long *l = (long long *)va_arg(args, long long *);
1960                                 *l = simple_strtoll(str, &next, base);
1961                         } else {
1962                                 unsigned long long *l = (unsigned long long *)va_arg(args, unsigned long long *);
1963                                 *l = simple_strtoull(str, &next, base);
1964                         }
1965                         break;
1966                 case 'Z':
1967                 case 'z':
1968                 {
1969                         size_t *s = (size_t *)va_arg(args, size_t *);
1970                         *s = (size_t)simple_strtoul(str, &next, base);
1971                 }
1972                 break;
1973                 default:
1974                         if (is_sign) {
1975                                 int *i = (int *)va_arg(args, int *);
1976                                 *i = (int)simple_strtol(str, &next, base);
1977                         } else {
1978                                 unsigned int *i = (unsigned int *)va_arg(args, unsigned int*);
1979                                 *i = (unsigned int)simple_strtoul(str, &next, base);
1980                         }
1981                         break;
1982                 }
1983                 num++;
1984
1985                 if (!next)
1986                         break;
1987                 str = next;
1988         }
1989
1990         /*
1991          * Now we've come all the way through so either the input string or the
1992          * format ended. In the former case, there can be a %n at the current
1993          * position in the format that needs to be filled.
1994          */
1995         if (*fmt == '%' && *(fmt + 1) == 'n') {
1996                 int *p = (int *)va_arg(args, int *);
1997                 *p = str - buf;
1998         }
1999
2000         return num;
2001 }
2002 EXPORT_SYMBOL(vsscanf);
2003
2004 /**
2005  * sscanf - Unformat a buffer into a list of arguments
2006  * @buf:        input buffer
2007  * @fmt:        formatting of buffer
2008  * @...:        resulting arguments
2009  */
2010 int sscanf(const char *buf, const char *fmt, ...)
2011 {
2012         va_list args;
2013         int i;
2014
2015         va_start(args, fmt);
2016         i = vsscanf(buf, fmt, args);
2017         va_end(args);
2018
2019         return i;
2020 }
2021 EXPORT_SYMBOL(sscanf);