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 ideas described at <http://www.cs.uiowa.edu/~jones/bcd/divide.html>
 116  * (with permission from the author, Douglas W. Jones).
 117  */
 118
 119 #if BITS_PER_LONG != 32 || BITS_PER_LONG_LONG != 64
 120 /* Formats correctly any integer in [0, 999999999] */
 121 static noinline_for_stack
 122 char *put_dec_full9(char *buf, unsigned q)
 123 {
 124         unsigned r;
 125
 126         /*
 127          * Possible ways to approx. divide by 10
 128          * (x * 0x1999999a) >> 32 x < 1073741829 (multiply must be 64-bit)
 129          * (x * 0xcccd) >> 19     x <      81920 (x < 262149 when 64-bit mul)
 130          * (x * 0x6667) >> 18     x <      43699
 131          * (x * 0x3334) >> 17     x <      16389
 132          * (x * 0x199a) >> 16     x <      16389
 133          * (x * 0x0ccd) >> 15     x <      16389
 134          * (x * 0x0667) >> 14     x <       2739
 135          * (x * 0x0334) >> 13     x <       1029
 136          * (x * 0x019a) >> 12     x <       1029
 137          * (x * 0x00cd) >> 11     x <       1029 shorter code than * 0x67 (on i386)
 138          * (x * 0x0067) >> 10     x <        179
 139          * (x * 0x0034) >>  9     x <         69 same
 140          * (x * 0x001a) >>  8     x <         69 same
 141          * (x * 0x000d) >>  7     x <         69 same, shortest code (on i386)
 142          * (x * 0x0007) >>  6     x <         19
 143          * See <http://www.cs.uiowa.edu/~jones/bcd/divide.html>
 144          */
 145         r      = (q * (uint64_t)0x1999999a) >> 32;
 146         *buf++ = (q - 10 * r) + '0'; /* 1 */
 147         q      = (r * (uint64_t)0x1999999a) >> 32;
 148         *buf++ = (r - 10 * q) + '0'; /* 2 */
 149         r      = (q * (uint64_t)0x1999999a) >> 32;
 150         *buf++ = (q - 10 * r) + '0'; /* 3 */
 151         q      = (r * (uint64_t)0x1999999a) >> 32;
 152         *buf++ = (r - 10 * q) + '0'; /* 4 */
 153         r      = (q * (uint64_t)0x1999999a) >> 32;
 154         *buf++ = (q - 10 * r) + '0'; /* 5 */
 155         /* Now value is under 10000, can avoid 64-bit multiply */
 156         q      = (r * 0x199a) >> 16;
 157         *buf++ = (r - 10 * q)  + '0'; /* 6 */
 158         r      = (q * 0xcd) >> 11;
 159         *buf++ = (q - 10 * r)  + '0'; /* 7 */
 160         q      = (r * 0xcd) >> 11;
 161         *buf++ = (r - 10 * q) + '0'; /* 8 */
 162         *buf++ = q + '0'; /* 9 */
 163         return buf;
 164 }
 165 #endif
 166
 167 /* Similar to above but do not pad with zeros.
 168  * Code can be easily arranged to print 9 digits too, but our callers
 169  * always call put_dec_full9() instead when the number has 9 decimal digits.
 170  */
 171 static noinline_for_stack
 172 char *put_dec_trunc8(char *buf, unsigned r)
 173 {
 174         unsigned q;
 175
 176         /* Copy of previous function's body with added early returns */
 177         while (r >= 10000) {
 178                 q = r + '0';
 179                 r  = (r * (uint64_t)0x1999999a) >> 32;
 180                 *buf++ = q - 10*r;
 181         }
 182
 183         q      = (r * 0x199a) >> 16;    /* r <= 9999 */
 184         *buf++ = (r - 10 * q)  + '0';
 185         if (q == 0)
 186                 return buf;
 187         r      = (q * 0xcd) >> 11;      /* q <= 999 */
 188         *buf++ = (q - 10 * r)  + '0';
 189         if (r == 0)
 190                 return buf;
 191         q      = (r * 0xcd) >> 11;      /* r <= 99 */
 192         *buf++ = (r - 10 * q) + '0';
 193         if (q == 0)
 194                 return buf;
 195         *buf++ = q + '0';                /* q <= 9 */
 196         return buf;
 197 }
 198
 199 /* There are two algorithms to print larger numbers.
 200  * One is generic: divide by 1000000000 and repeatedly print
 201  * groups of (up to) 9 digits. It's conceptually simple,
 202  * but requires a (unsigned long long) / 1000000000 division.
 203  *
 204  * Second algorithm splits 64-bit unsigned long long into 16-bit chunks,
 205  * manipulates them cleverly and generates groups of 4 decimal digits.
 206  * It so happens that it does NOT require long long division.
 207  *
 208  * If long is > 32 bits, division of 64-bit values is relatively easy,
 209  * and we will use the first algorithm.
 210  * If long long is > 64 bits (strange architecture with VERY large long long),
 211  * second algorithm can't be used, and we again use the first one.
 212  *
 213  * Else (if long is 32 bits and long long is 64 bits) we use second one.
 214  */
 215
 216 #if BITS_PER_LONG != 32 || BITS_PER_LONG_LONG != 64
 217
 218 /* First algorithm: generic */
 219
 220 static
 221 char *put_dec(char *buf, unsigned long long n)
 222 {
 223         if (n >= 100*1000*1000) {
 224                 while (n >= 1000*1000*1000)
 225                         buf = put_dec_full9(buf, do_div(n, 1000*1000*1000));
 226                 if (n >= 100*1000*1000)
 227                         return put_dec_full9(buf, n);
 228         }
 229         return put_dec_trunc8(buf, n);
 230 }
 231
 232 #else
 233
 234 /* Second algorithm: valid only for 64-bit long longs */
 235
 236 /* See comment in put_dec_full9 for choice of constants */
 237 static noinline_for_stack
 238 void put_dec_full4(char *buf, unsigned q)
 239 {
 240         unsigned r;
 241         r      = (q * 0xccd) >> 15;
 242         buf[0] = (q - 10 * r) + '0';
 243         q      = (r * 0xcd) >> 11;
 244         buf[1] = (r - 10 * q)  + '0';
 245         r      = (q * 0xcd) >> 11;
 246         buf[2] = (q - 10 * r)  + '0';
 247         buf[3] = r + '0';
 248 }
 249
 250 /*
 251  * Call put_dec_full4 on x % 10000, return x / 10000.
 252  * The approximation x/10000 == (x * 0x346DC5D7) >> 43
 253  * holds for all x < 1,128,869,999.  The largest value this
 254  * helper will ever be asked to convert is 1,125,520,955.
 255  * (d1 in the put_dec code, assuming n is all-ones).
 256  */
 257 static
 258 unsigned put_dec_helper4(char *buf, unsigned x)
 259 {
 260         uint32_t q = (x * (uint64_t)0x346DC5D7) >> 43;
 261
 262         put_dec_full4(buf, x - q * 10000);
 263         return q;
 264 }
 265
 266 /* Based on code by Douglas W. Jones found at
 267  * <http://www.cs.uiowa.edu/~jones/bcd/decimal.html#sixtyfour>
 268  * (with permission from the author).
 269  * Performs no 64-bit division and hence should be fast on 32-bit machines.
 270  */
 271 static
 272 char *put_dec(char *buf, unsigned long long n)
 273 {
 274         uint32_t d3, d2, d1, q, h;
 275
 276         if (n < 100*1000*1000)
 277                 return put_dec_trunc8(buf, n);
 278
 279         d1  = ((uint32_t)n >> 16); /* implicit "& 0xffff" */
 280         h   = (n >> 32);
 281         d2  = (h      ) & 0xffff;
 282         d3  = (h >> 16); /* implicit "& 0xffff" */
 283
 284         q   = 656 * d3 + 7296 * d2 + 5536 * d1 + ((uint32_t)n & 0xffff);
 285         q = put_dec_helper4(buf, q);
 286
 287         q += 7671 * d3 + 9496 * d2 + 6 * d1;
 288         q = put_dec_helper4(buf+4, q);
 289
 290         q += 4749 * d3 + 42 * d2;
 291         q = put_dec_helper4(buf+8, q);
 292
 293         q += 281 * d3;
 294         buf += 12;
 295         if (q)
 296                 buf = put_dec_trunc8(buf, q);
 297         else while (buf[-1] == '0')
 298                 --buf;
 299
 300         return buf;
 301 }
 302
 303 #endif
 304
 305 /*
 306  * Convert passed number to decimal string.
 307  * Returns the length of string.  On buffer overflow, returns 0.
 308  *
 309  * If speed is not important, use snprintf(). It's easy to read the code.
 310  */
 311 int num_to_str(char *buf, int size, unsigned long long num)
 312 {
 313         char tmp[sizeof(num) * 3];
 314         int idx, len;
 315
 316         /* put_dec() may work incorrectly for num = 0 (generate "", not "0") */
 317         if (num <= 9) {
 318                 tmp[0] = '0' + num;
 319                 len = 1;
 320         } else {
 321                 len = put_dec(tmp, num) - tmp;
 322         }
 323
 324         if (len > size)
 325                 return 0;
 326         for (idx = 0; idx < len; ++idx)
 327                 buf[idx] = tmp[len - idx - 1];
 328         return len;
 329 }
 330
 331 #define ZEROPAD 1               /* pad with zero */
 332 #define SIGN    2               /* unsigned/signed long */
 333 #define PLUS    4               /* show plus */
 334 #define SPACE   8               /* space if plus */
 335 #define LEFT    16              /* left justified */
 336 #define SMALL   32              /* use lowercase in hex (must be 32 == 0x20) */
 337 #define SPECIAL 64              /* prefix hex with "0x", octal with "0" */
 338
 339 enum format_type {
 340         FORMAT_TYPE_NONE, /* Just a string part */
 341         FORMAT_TYPE_WIDTH,
 342         FORMAT_TYPE_PRECISION,
 343         FORMAT_TYPE_CHAR,
 344         FORMAT_TYPE_STR,
 345         FORMAT_TYPE_PTR,
 346         FORMAT_TYPE_PERCENT_CHAR,
 347         FORMAT_TYPE_INVALID,
 348         FORMAT_TYPE_LONG_LONG,
 349         FORMAT_TYPE_ULONG,
 350         FORMAT_TYPE_LONG,
 351         FORMAT_TYPE_UBYTE,
 352         FORMAT_TYPE_BYTE,
 353         FORMAT_TYPE_USHORT,
 354         FORMAT_TYPE_SHORT,
 355         FORMAT_TYPE_UINT,
 356         FORMAT_TYPE_INT,
 357         FORMAT_TYPE_NRCHARS,
 358         FORMAT_TYPE_SIZE_T,
 359         FORMAT_TYPE_PTRDIFF
 360 };
 361
 362 struct printf_spec {
 363         u8      type;           /* format_type enum */
 364         u8      flags;          /* flags to number() */
 365         u8      base;           /* number base, 8, 10 or 16 only */
 366         u8      qualifier;      /* number qualifier, one of 'hHlLtzZ' */
 367         s16     field_width;    /* width of output field */
 368         s16     precision;      /* # of digits/chars */
 369 };
 370
 371 static noinline_for_stack
 372 char *number(char *buf, char *end, unsigned long long num,
 373              struct printf_spec spec)
 374 {
 375         /* we are called with base 8, 10 or 16, only, thus don't need "G..."  */
 376         static const char digits[16] = "0123456789ABCDEF"; /* "GHIJKLMNOPQRSTUVWXYZ"; */
 377
 378         char tmp[66];
 379         char sign;
 380         char locase;
 381         int need_pfx = ((spec.flags & SPECIAL) && spec.base != 10);
 382         int i;
 383         bool is_zero = num == 0LL;
 384
 385         /* locase = 0 or 0x20. ORing digits or letters with 'locase'
 386          * produces same digits or (maybe lowercased) letters */
 387         locase = (spec.flags & SMALL);
 388         if (spec.flags & LEFT)
 389                 spec.flags &= ~ZEROPAD;
 390         sign = 0;
 391         if (spec.flags & SIGN) {
 392                 if ((signed long long)num < 0) {
 393                         sign = '-';
 394                         num = -(signed long long)num;
 395                         spec.field_width--;
 396                 } else if (spec.flags & PLUS) {
 397                         sign = '+';
 398                         spec.field_width--;
 399                 } else if (spec.flags & SPACE) {
 400                         sign = ' ';
 401                         spec.field_width--;
 402                 }
 403         }
 404         if (need_pfx) {
 405                 if (spec.base == 16)
 406                         spec.field_width -= 2;
 407                 else if (!is_zero)
 408                         spec.field_width--;
 409         }
 410
 411         /* generate full string in tmp[], in reverse order */
 412         i = 0;
 413         if (num < spec.base)
 414                 tmp[i++] = digits[num] | locase;
 415         /* Generic code, for any base:
 416         else do {
 417                 tmp[i++] = (digits[do_div(num,base)] | locase);
 418         } while (num != 0);
 419         */
 420         else if (spec.base != 10) { /* 8 or 16 */
 421                 int mask = spec.base - 1;
 422                 int shift = 3;
 423
 424                 if (spec.base == 16)
 425                         shift = 4;
 426                 do {
 427                         tmp[i++] = (digits[((unsigned char)num) & mask] | locase);
 428                         num >>= shift;
 429                 } while (num);
 430         } else { /* base 10 */
 431                 i = put_dec(tmp, num) - tmp;
 432         }
 433
 434         /* printing 100 using %2d gives "100", not "00" */
 435         if (i > spec.precision)
 436                 spec.precision = i;
 437         /* leading space padding */
 438         spec.field_width -= spec.precision;
 439         if (!(spec.flags & (ZEROPAD+LEFT))) {
 440                 while (--spec.field_width >= 0) {
 441                         if (buf < end)
 442                                 *buf = ' ';
 443                         ++buf;
 444                 }
 445         }
 446         /* sign */
 447         if (sign) {
 448                 if (buf < end)
 449                         *buf = sign;
 450                 ++buf;
 451         }
 452         /* "0x" / "0" prefix */
 453         if (need_pfx) {
 454                 if (spec.base == 16 || !is_zero) {
 455                         if (buf < end)
 456                                 *buf = '0';
 457                         ++buf;
 458                 }
 459                 if (spec.base == 16) {
 460                         if (buf < end)
 461                                 *buf = ('X' | locase);
 462                         ++buf;
 463                 }
 464         }
 465         /* zero or space padding */
 466         if (!(spec.flags & LEFT)) {
 467                 char c = (spec.flags & ZEROPAD) ? '0' : ' ';
 468                 while (--spec.field_width >= 0) {
 469                         if (buf < end)
 470                                 *buf = c;
 471                         ++buf;
 472                 }
 473         }
 474         /* hmm even more zero padding? */
 475         while (i <= --spec.precision) {
 476                 if (buf < end)
 477                         *buf = '0';
 478                 ++buf;
 479         }
 480         /* actual digits of result */
 481         while (--i >= 0) {
 482                 if (buf < end)
 483                         *buf = tmp[i];
 484                 ++buf;
 485         }
 486         /* trailing space padding */
 487         while (--spec.field_width >= 0) {
 488                 if (buf < end)
 489                         *buf = ' ';
 490                 ++buf;
 491         }
 492
 493         return buf;
 494 }
 495
 496 static noinline_for_stack
 497 char *string(char *buf, char *end, const char *s, struct printf_spec spec)
 498 {
 499         int len, i;
 500
 501         if ((unsigned long)s < PAGE_SIZE)
 502                 s = "(null)";
 503
 504         len = strnlen(s, spec.precision);
 505
 506         if (!(spec.flags & LEFT)) {
 507                 while (len < spec.field_width--) {
 508                         if (buf < end)
 509                                 *buf = ' ';
 510                         ++buf;
 511                 }
 512         }
 513         for (i = 0; i < len; ++i) {
 514                 if (buf < end)
 515                         *buf = *s;
 516                 ++buf; ++s;
 517         }
 518         while (len < spec.field_width--) {
 519                 if (buf < end)
 520                         *buf = ' ';
 521                 ++buf;
 522         }
 523
 524         return buf;
 525 }
 526
 527 static noinline_for_stack
 528 char *symbol_string(char *buf, char *end, void *ptr,
 529                     struct printf_spec spec, char ext)
 530 {
 531         unsigned long value = (unsigned long) ptr;
 532 #ifdef CONFIG_KALLSYMS
 533         char sym[KSYM_SYMBOL_LEN];
 534         if (ext == 'B')
 535                 sprint_backtrace(sym, value);
 536         else if (ext != 'f' && ext != 's')
 537                 sprint_symbol(sym, value);
 538         else
 539                 sprint_symbol_no_offset(sym, value);
 540
 541         return string(buf, end, sym, spec);
 542 #else
 543         spec.field_width = 2 * sizeof(void *);
 544         spec.flags |= SPECIAL | SMALL | ZEROPAD;
 545         spec.base = 16;
 546
 547         return number(buf, end, value, spec);
 548 #endif
 549 }
 550
 551 static noinline_for_stack
 552 char *resource_string(char *buf, char *end, struct resource *res,
 553                       struct printf_spec spec, const char *fmt)
 554 {
 555 #ifndef IO_RSRC_PRINTK_SIZE
 556 #define IO_RSRC_PRINTK_SIZE     6
 557 #endif
 558
 559 #ifndef MEM_RSRC_PRINTK_SIZE
 560 #define MEM_RSRC_PRINTK_SIZE    10
 561 #endif
 562         static const struct printf_spec io_spec = {
 563                 .base = 16,
 564                 .field_width = IO_RSRC_PRINTK_SIZE,
 565                 .precision = -1,
 566                 .flags = SPECIAL | SMALL | ZEROPAD,
 567         };
 568         static const struct printf_spec mem_spec = {
 569                 .base = 16,
 570                 .field_width = MEM_RSRC_PRINTK_SIZE,
 571                 .precision = -1,
 572                 .flags = SPECIAL | SMALL | ZEROPAD,
 573         };
 574         static const struct printf_spec bus_spec = {
 575                 .base = 16,
 576                 .field_width = 2,
 577                 .precision = -1,
 578                 .flags = SMALL | ZEROPAD,
 579         };
 580         static const struct printf_spec dec_spec = {
 581                 .base = 10,
 582                 .precision = -1,
 583                 .flags = 0,
 584         };
 585         static const struct printf_spec str_spec = {
 586                 .field_width = -1,
 587                 .precision = 10,
 588                 .flags = LEFT,
 589         };
 590         static const struct printf_spec flag_spec = {
 591                 .base = 16,
 592                 .precision = -1,
 593                 .flags = SPECIAL | SMALL,
 594         };
 595
 596         /* 32-bit res (sizeof==4): 10 chars in dec, 10 in hex ("0x" + 8)
 597          * 64-bit res (sizeof==8): 20 chars in dec, 18 in hex ("0x" + 16) */
 598 #define RSRC_BUF_SIZE           ((2 * sizeof(resource_size_t)) + 4)
 599 #define FLAG_BUF_SIZE           (2 * sizeof(res->flags))
 600 #define DECODED_BUF_SIZE        sizeof("[mem - 64bit pref window disabled]")
 601 #define RAW_BUF_SIZE            sizeof("[mem - flags 0x]")
 602         char sym[max(2*RSRC_BUF_SIZE + DECODED_BUF_SIZE,
 603                      2*RSRC_BUF_SIZE + FLAG_BUF_SIZE + RAW_BUF_SIZE)];
 604
 605         char *p = sym, *pend = sym + sizeof(sym);
 606         int decode = (fmt[0] == 'R') ? 1 : 0;
 607         const struct printf_spec *specp;
 608
 609         *p++ = '[';
 610         if (res->flags & IORESOURCE_IO) {
 611                 p = string(p, pend, "io  ", str_spec);
 612                 specp = &io_spec;
 613         } else if (res->flags & IORESOURCE_MEM) {
 614                 p = string(p, pend, "mem ", str_spec);
 615                 specp = &mem_spec;
 616         } else if (res->flags & IORESOURCE_IRQ) {
 617                 p = string(p, pend, "irq ", str_spec);
 618                 specp = &dec_spec;
 619         } else if (res->flags & IORESOURCE_DMA) {
 620                 p = string(p, pend, "dma ", str_spec);
 621                 specp = &dec_spec;
 622         } else if (res->flags & IORESOURCE_BUS) {
 623                 p = string(p, pend, "bus ", str_spec);
 624                 specp = &bus_spec;
 625         } else {
 626                 p = string(p, pend, "??? ", str_spec);
 627                 specp = &mem_spec;
 628                 decode = 0;
 629         }
 630         p = number(p, pend, res->start, *specp);
 631         if (res->start != res->end) {
 632                 *p++ = '-';
 633                 p = number(p, pend, res->end, *specp);
 634         }
 635         if (decode) {
 636                 if (res->flags & IORESOURCE_MEM_64)
 637                         p = string(p, pend, " 64bit", str_spec);
 638                 if (res->flags & IORESOURCE_PREFETCH)
 639                         p = string(p, pend, " pref", str_spec);
 640                 if (res->flags & IORESOURCE_WINDOW)
 641                         p = string(p, pend, " window", str_spec);
 642                 if (res->flags & IORESOURCE_DISABLED)
 643                         p = string(p, pend, " disabled", str_spec);
 644         } else {
 645                 p = string(p, pend, " flags ", str_spec);
 646                 p = number(p, pend, res->flags, flag_spec);
 647         }
 648         *p++ = ']';
 649         *p = '\0';
 650
 651         return string(buf, end, sym, spec);
 652 }
 653
 654 static noinline_for_stack
 655 char *hex_string(char *buf, char *end, u8 *addr, struct printf_spec spec,
 656                  const char *fmt)
 657 {
 658         int i, len = 1;         /* if we pass '%ph[CDN]', field witdh remains
 659                                    negative value, fallback to the default */
 660         char separator;
 661
 662         if (spec.field_width == 0)
 663                 /* nothing to print */
 664                 return buf;
 665
 666         if (ZERO_OR_NULL_PTR(addr))
 667                 /* NULL pointer */
 668                 return string(buf, end, NULL, spec);
 669
 670         switch (fmt[1]) {
 671         case 'C':
 672                 separator = ':';
 673                 break;
 674         case 'D':
 675                 separator = '-';
 676                 break;
 677         case 'N':
 678                 separator = 0;
 679                 break;
 680         default:
 681                 separator = ' ';
 682                 break;
 683         }
 684
 685         if (spec.field_width > 0)
 686                 len = min_t(int, spec.field_width, 64);
 687
 688         for (i = 0; i < len && buf < end - 1; i++) {
 689                 buf = hex_byte_pack(buf, addr[i]);
 690
 691                 if (buf < end && separator && i != len - 1)
 692                         *buf++ = separator;
 693         }
 694
 695         return buf;
 696 }
 697
 698 static noinline_for_stack
 699 char *mac_address_string(char *buf, char *end, u8 *addr,
 700                          struct printf_spec spec, const char *fmt)
 701 {
 702         char mac_addr[sizeof("xx:xx:xx:xx:xx:xx")];
 703         char *p = mac_addr;
 704         int i;
 705         char separator;
 706         bool reversed = false;
 707
 708         switch (fmt[1]) {
 709         case 'F':
 710                 separator = '-';
 711                 break;
 712
 713         case 'R':
 714                 reversed = true;
 715                 /* fall through */
 716
 717         default:
 718                 separator = ':';
 719                 break;
 720         }
 721
 722         for (i = 0; i < 6; i++) {
 723                 if (reversed)
 724                         p = hex_byte_pack(p, addr[5 - i]);
 725                 else
 726                         p = hex_byte_pack(p, addr[i]);
 727
 728                 if (fmt[0] == 'M' && i != 5)
 729                         *p++ = separator;
 730         }
 731         *p = '\0';
 732
 733         return string(buf, end, mac_addr, spec);
 734 }
 735
 736 static noinline_for_stack
 737 char *ip4_string(char *p, const u8 *addr, const char *fmt)
 738 {
 739         int i;
 740         bool leading_zeros = (fmt[0] == 'i');
 741         int index;
 742         int step;
 743
 744         switch (fmt[2]) {
 745         case 'h':
 746 #ifdef __BIG_ENDIAN
 747                 index = 0;
 748                 step = 1;
 749 #else
 750                 index = 3;
 751                 step = -1;
 752 #endif
 753                 break;
 754         case 'l':
 755                 index = 3;
 756                 step = -1;
 757                 break;
 758         case 'n':
 759         case 'b':
 760         default:
 761                 index = 0;
 762                 step = 1;
 763                 break;
 764         }
 765         for (i = 0; i < 4; i++) {
 766                 char temp[3];   /* hold each IP quad in reverse order */
 767                 int digits = put_dec_trunc8(temp, addr[index]) - temp;
 768                 if (leading_zeros) {
 769                         if (digits < 3)
 770                                 *p++ = '0';
 771                         if (digits < 2)
 772                                 *p++ = '0';
 773                 }
 774                 /* reverse the digits in the quad */
 775                 while (digits--)
 776                         *p++ = temp[digits];
 777                 if (i < 3)
 778                         *p++ = '.';
 779                 index += step;
 780         }
 781         *p = '\0';
 782
 783         return p;
 784 }
 785
 786 static noinline_for_stack
 787 char *ip6_compressed_string(char *p, const char *addr)
 788 {
 789         int i, j, range;
 790         unsigned char zerolength[8];
 791         int longest = 1;
 792         int colonpos = -1;
 793         u16 word;
 794         u8 hi, lo;
 795         bool needcolon = false;
 796         bool useIPv4;
 797         struct in6_addr in6;
 798
 799         memcpy(&in6, addr, sizeof(struct in6_addr));
 800
 801         useIPv4 = ipv6_addr_v4mapped(&in6) || ipv6_addr_is_isatap(&in6);
 802
 803         memset(zerolength, 0, sizeof(zerolength));
 804
 805         if (useIPv4)
 806                 range = 6;
 807         else
 808                 range = 8;
 809
 810         /* find position of longest 0 run */
 811         for (i = 0; i < range; i++) {
 812                 for (j = i; j < range; j++) {
 813                         if (in6.s6_addr16[j] != 0)
 814                                 break;
 815                         zerolength[i]++;
 816                 }
 817         }
 818         for (i = 0; i < range; i++) {
 819                 if (zerolength[i] > longest) {
 820                         longest = zerolength[i];
 821                         colonpos = i;
 822                 }
 823         }
 824         if (longest == 1)               /* don't compress a single 0 */
 825                 colonpos = -1;
 826
 827         /* emit address */
 828         for (i = 0; i < range; i++) {
 829                 if (i == colonpos) {
 830                         if (needcolon || i == 0)
 831                                 *p++ = ':';
 832                         *p++ = ':';
 833                         needcolon = false;
 834                         i += longest - 1;
 835                         continue;
 836                 }
 837                 if (needcolon) {
 838                         *p++ = ':';
 839                         needcolon = false;
 840                 }
 841                 /* hex u16 without leading 0s */
 842                 word = ntohs(in6.s6_addr16[i]);
 843                 hi = word >> 8;
 844                 lo = word & 0xff;
 845                 if (hi) {
 846                         if (hi > 0x0f)
 847                                 p = hex_byte_pack(p, hi);
 848                         else
 849                                 *p++ = hex_asc_lo(hi);
 850                         p = hex_byte_pack(p, lo);
 851                 }
 852                 else if (lo > 0x0f)
 853                         p = hex_byte_pack(p, lo);
 854                 else
 855                         *p++ = hex_asc_lo(lo);
 856                 needcolon = true;
 857         }
 858
 859         if (useIPv4) {
 860                 if (needcolon)
 861                         *p++ = ':';
 862                 p = ip4_string(p, &in6.s6_addr[12], "I4");
 863         }
 864         *p = '\0';
 865
 866         return p;
 867 }
 868
 869 static noinline_for_stack
 870 char *ip6_string(char *p, const char *addr, const char *fmt)
 871 {
 872         int i;
 873
 874         for (i = 0; i < 8; i++) {
 875                 p = hex_byte_pack(p, *addr++);
 876                 p = hex_byte_pack(p, *addr++);
 877                 if (fmt[0] == 'I' && i != 7)
 878                         *p++ = ':';
 879         }
 880         *p = '\0';
 881
 882         return p;
 883 }
 884
 885 static noinline_for_stack
 886 char *ip6_addr_string(char *buf, char *end, const u8 *addr,
 887                       struct printf_spec spec, const char *fmt)
 888 {
 889         char ip6_addr[sizeof("xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255")];
 890
 891         if (fmt[0] == 'I' && fmt[2] == 'c')
 892                 ip6_compressed_string(ip6_addr, addr);
 893         else
 894                 ip6_string(ip6_addr, addr, fmt);
 895
 896         return string(buf, end, ip6_addr, spec);
 897 }
 898
 899 static noinline_for_stack
 900 char *ip4_addr_string(char *buf, char *end, const u8 *addr,
 901                       struct printf_spec spec, const char *fmt)
 902 {
 903         char ip4_addr[sizeof("255.255.255.255")];
 904
 905         ip4_string(ip4_addr, addr, fmt);
 906
 907         return string(buf, end, ip4_addr, spec);
 908 }
 909
 910 static noinline_for_stack
 911 char *uuid_string(char *buf, char *end, const u8 *addr,
 912                   struct printf_spec spec, const char *fmt)
 913 {
 914         char uuid[sizeof("xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx")];
 915         char *p = uuid;
 916         int i;
 917         static const u8 be[16] = {0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15};
 918         static const u8 le[16] = {3,2,1,0,5,4,7,6,8,9,10,11,12,13,14,15};
 919         const u8 *index = be;
 920         bool uc = false;
 921
 922         switch (*(++fmt)) {
 923         case 'L':
 924                 uc = true;              /* fall-through */
 925         case 'l':
 926                 index = le;
 927                 break;
 928         case 'B':
 929                 uc = true;
 930                 break;
 931         }
 932
 933         for (i = 0; i < 16; i++) {
 934                 p = hex_byte_pack(p, addr[index[i]]);
 935                 switch (i) {
 936                 case 3:
 937                 case 5:
 938                 case 7:
 939                 case 9:
 940                         *p++ = '-';
 941                         break;
 942                 }
 943         }
 944
 945         *p = 0;
 946
 947         if (uc) {
 948                 p = uuid;
 949                 do {
 950                         *p = toupper(*p);
 951                 } while (*(++p));
 952         }
 953
 954         return string(buf, end, uuid, spec);
 955 }
 956
 957 static
 958 char *netdev_feature_string(char *buf, char *end, const u8 *addr,
 959                       struct printf_spec spec)
 960 {
 961         spec.flags |= SPECIAL | SMALL | ZEROPAD;
 962         if (spec.field_width == -1)
 963                 spec.field_width = 2 + 2 * sizeof(netdev_features_t);
 964         spec.base = 16;
 965
 966         return number(buf, end, *(const netdev_features_t *)addr, spec);
 967 }
 968
 969 int kptr_restrict __read_mostly;
 970
 971 /*
 972  * Show a '%p' thing.  A kernel extension is that the '%p' is followed
 973  * by an extra set of alphanumeric characters that are extended format
 974  * specifiers.
 975  *
 976  * Right now we handle:
 977  *
 978  * - 'F' For symbolic function descriptor pointers with offset
 979  * - 'f' For simple symbolic function names without offset
 980  * - 'S' For symbolic direct pointers with offset
 981  * - 's' For symbolic direct pointers without offset
 982  * - 'B' For backtraced symbolic direct pointers with offset
 983  * - 'R' For decoded struct resource, e.g., [mem 0x0-0x1f 64bit pref]
 984  * - 'r' For raw struct resource, e.g., [mem 0x0-0x1f flags 0x201]
 985  * - 'M' For a 6-byte MAC address, it prints the address in the
 986  *       usual colon-separated hex notation
 987  * - 'm' For a 6-byte MAC address, it prints the hex address without colons
 988  * - 'MF' For a 6-byte MAC FDDI address, it prints the address
 989  *       with a dash-separated hex notation
 990  * - '[mM]R' For a 6-byte MAC address, Reverse order (Bluetooth)
 991  * - 'I' [46] for IPv4/IPv6 addresses printed in the usual way
 992  *       IPv4 uses dot-separated decimal without leading 0's (1.2.3.4)
 993  *       IPv6 uses colon separated network-order 16 bit hex with leading 0's
 994  * - 'i' [46] for 'raw' IPv4/IPv6 addresses
 995  *       IPv6 omits the colons (01020304...0f)
 996  *       IPv4 uses dot-separated decimal with leading 0's (010.123.045.006)
 997  * - '[Ii]4[hnbl]' IPv4 addresses in host, network, big or little endian order
 998  * - 'I6c' for IPv6 addresses printed as specified by
 999  *       http://tools.ietf.org/html/rfc5952
1000  * - 'U' For a 16 byte UUID/GUID, it prints the UUID/GUID in the form
1001  *       "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx"
1002  *       Options for %pU are:
1003  *         b big endian lower case hex (default)
1004  *         B big endian UPPER case hex
1005  *         l little endian lower case hex
1006  *         L little endian UPPER case hex
1007  *           big endian output byte order is:
1008  *             [0][1][2][3]-[4][5]-[6][7]-[8][9]-[10][11][12][13][14][15]
1009  *           little endian output byte order is:
1010  *             [3][2][1][0]-[5][4]-[7][6]-[8][9]-[10][11][12][13][14][15]
1011  * - 'V' For a struct va_format which contains a format string * and va_list *,
1012  *       call vsnprintf(->format, *->va_list).
1013  *       Implements a "recursive vsnprintf".
1014  *       Do not use this feature without some mechanism to verify the
1015  *       correctness of the format string and va_list arguments.
1016  * - 'K' For a kernel pointer that should be hidden from unprivileged users
1017  * - 'NF' For a netdev_features_t
1018  * - 'h[CDN]' For a variable-length buffer, it prints it as a hex string with
1019  *            a certain separator (' ' by default):
1020  *              C colon
1021  *              D dash
1022  *              N no separator
1023  *            The maximum supported length is 64 bytes of the input. Consider
1024  *            to use print_hex_dump() for the larger input.
1025  *
1026  * Note: The difference between 'S' and 'F' is that on ia64 and ppc64
1027  * function pointers are really function descriptors, which contain a
1028  * pointer to the real address.
1029  */
1030 static noinline_for_stack
1031 char *pointer(const char *fmt, char *buf, char *end, void *ptr,
1032               struct printf_spec spec)
1033 {
1034         int default_width = 2 * sizeof(void *) + (spec.flags & SPECIAL ? 2 : 0);
1035
1036         if (!ptr && *fmt != 'K') {
1037                 /*
1038                  * Print (null) with the same width as a pointer so it makes
1039                  * tabular output look nice.
1040                  */
1041                 if (spec.field_width == -1)
1042                         spec.field_width = default_width;
1043                 return string(buf, end, "(null)", spec);
1044         }
1045
1046         switch (*fmt) {
1047         case 'F':
1048         case 'f':
1049                 ptr = dereference_function_descriptor(ptr);
1050                 /* Fallthrough */
1051         case 'S':
1052         case 's':
1053         case 'B':
1054                 return symbol_string(buf, end, ptr, spec, *fmt);
1055         case 'R':
1056         case 'r':
1057                 return resource_string(buf, end, ptr, spec, fmt);
1058         case 'h':
1059                 return hex_string(buf, end, ptr, spec, fmt);
1060         case 'M':                       /* Colon separated: 00:01:02:03:04:05 */
1061         case 'm':                       /* Contiguous: 000102030405 */
1062                                         /* [mM]F (FDDI) */
1063                                         /* [mM]R (Reverse order; Bluetooth) */
1064                 return mac_address_string(buf, end, ptr, spec, fmt);
1065         case 'I':                       /* Formatted IP supported
1066                                          * 4:   1.2.3.4
1067                                          * 6:   0001:0203:...:0708
1068                                          * 6c:  1::708 or 1::1.2.3.4
1069                                          */
1070         case 'i':                       /* Contiguous:
1071                                          * 4:   001.002.003.004
1072                                          * 6:   000102...0f
1073                                          */
1074                 switch (fmt[1]) {
1075                 case '6':
1076                         return ip6_addr_string(buf, end, ptr, spec, fmt);
1077                 case '4':
1078                         return ip4_addr_string(buf, end, ptr, spec, fmt);
1079                 }
1080                 break;
1081         case 'U':
1082                 return uuid_string(buf, end, ptr, spec, fmt);
1083         case 'V':
1084                 {
1085                         va_list va;
1086
1087                         va_copy(va, *((struct va_format *)ptr)->va);
1088                         buf += vsnprintf(buf, end > buf ? end - buf : 0,
1089                                          ((struct va_format *)ptr)->fmt, va);
1090                         va_end(va);
1091                         return buf;
1092                 }
1093         case 'K':
1094                 /*
1095                  * %pK cannot be used in IRQ context because its test
1096                  * for CAP_SYSLOG would be meaningless.
1097                  */
1098                 if (kptr_restrict && (in_irq() || in_serving_softirq() ||
1099                                       in_nmi())) {
1100                         if (spec.field_width == -1)
1101                                 spec.field_width = default_width;
1102                         return string(buf, end, "pK-error", spec);
1103                 }
1104                 if (!((kptr_restrict == 0) ||
1105                       (kptr_restrict == 1 &&
1106                        has_capability_noaudit(current, CAP_SYSLOG))))
1107                         ptr = NULL;
1108                 break;
1109         case 'N':
1110                 switch (fmt[1]) {
1111                 case 'F':
1112                         return netdev_feature_string(buf, end, ptr, spec);
1113                 }
1114                 break;
1115         }
1116         spec.flags |= SMALL;
1117         if (spec.field_width == -1) {
1118                 spec.field_width = default_width;
1119                 spec.flags |= ZEROPAD;
1120         }
1121         spec.base = 16;
1122
1123         return number(buf, end, (unsigned long) ptr, spec);
1124 }
1125
1126 /*
1127  * Helper function to decode printf style format.
1128  * Each call decode a token from the format and return the
1129  * number of characters read (or likely the delta where it wants
1130  * to go on the next call).
1131  * The decoded token is returned through the parameters
1132  *
1133  * 'h', 'l', or 'L' for integer fields
1134  * 'z' support added 23/7/1999 S.H.
1135  * 'z' changed to 'Z' --davidm 1/25/99
1136  * 't' added for ptrdiff_t
1137  *
1138  * @fmt: the format string
1139  * @type of the token returned
1140  * @flags: various flags such as +, -, # tokens..
1141  * @field_width: overwritten width
1142  * @base: base of the number (octal, hex, ...)
1143  * @precision: precision of a number
1144  * @qualifier: qualifier of a number (long, size_t, ...)
1145  */
1146 static noinline_for_stack
1147 int format_decode(const char *fmt, struct printf_spec *spec)
1148 {
1149         const char *start = fmt;
1150
1151         /* we finished early by reading the field width */
1152         if (spec->type == FORMAT_TYPE_WIDTH) {
1153                 if (spec->field_width < 0) {
1154                         spec->field_width = -spec->field_width;
1155                         spec->flags |= LEFT;
1156                 }
1157                 spec->type = FORMAT_TYPE_NONE;
1158                 goto precision;
1159         }
1160
1161         /* we finished early by reading the precision */
1162         if (spec->type == FORMAT_TYPE_PRECISION) {
1163                 if (spec->precision < 0)
1164                         spec->precision = 0;
1165
1166                 spec->type = FORMAT_TYPE_NONE;
1167                 goto qualifier;
1168         }
1169
1170         /* By default */
1171         spec->type = FORMAT_TYPE_NONE;
1172
1173         for (; *fmt ; ++fmt) {
1174                 if (*fmt == '%')
1175                         break;
1176         }
1177
1178         /* Return the current non-format string */
1179         if (fmt != start || !*fmt)
1180                 return fmt - start;
1181
1182         /* Process flags */
1183         spec->flags = 0;
1184
1185         while (1) { /* this also skips first '%' */
1186                 bool found = true;
1187
1188                 ++fmt;
1189
1190                 switch (*fmt) {
1191                 case '-': spec->flags |= LEFT;    break;
1192                 case '+': spec->flags |= PLUS;    break;
1193                 case ' ': spec->flags |= SPACE;   break;
1194                 case '#': spec->flags |= SPECIAL; break;
1195                 case '0': spec->flags |= ZEROPAD; break;
1196                 default:  found = false;
1197                 }
1198
1199                 if (!found)
1200                         break;
1201         }
1202
1203         /* get field width */
1204         spec->field_width = -1;
1205
1206         if (isdigit(*fmt))
1207                 spec->field_width = skip_atoi(&fmt);
1208         else if (*fmt == '*') {
1209                 /* it's the next argument */
1210                 spec->type = FORMAT_TYPE_WIDTH;
1211                 return ++fmt - start;
1212         }
1213
1214 precision:
1215         /* get the precision */
1216         spec->precision = -1;
1217         if (*fmt == '.') {
1218                 ++fmt;
1219                 if (isdigit(*fmt)) {
1220                         spec->precision = skip_atoi(&fmt);
1221                         if (spec->precision < 0)
1222                                 spec->precision = 0;
1223                 } else if (*fmt == '*') {
1224                         /* it's the next argument */
1225                         spec->type = FORMAT_TYPE_PRECISION;
1226                         return ++fmt - start;
1227                 }
1228         }
1229
1230 qualifier:
1231         /* get the conversion qualifier */
1232         spec->qualifier = -1;
1233         if (*fmt == 'h' || _tolower(*fmt) == 'l' ||
1234             _tolower(*fmt) == 'z' || *fmt == 't') {
1235                 spec->qualifier = *fmt++;
1236                 if (unlikely(spec->qualifier == *fmt)) {
1237                         if (spec->qualifier == 'l') {
1238                                 spec->qualifier = 'L';
1239                                 ++fmt;
1240                         } else if (spec->qualifier == 'h') {
1241                                 spec->qualifier = 'H';
1242                                 ++fmt;
1243                         }
1244                 }
1245         }
1246
1247         /* default base */
1248         spec->base = 10;
1249         switch (*fmt) {
1250         case 'c':
1251                 spec->type = FORMAT_TYPE_CHAR;
1252                 return ++fmt - start;
1253
1254         case 's':
1255                 spec->type = FORMAT_TYPE_STR;
1256                 return ++fmt - start;
1257
1258         case 'p':
1259                 spec->type = FORMAT_TYPE_PTR;
1260                 return fmt - start;
1261                 /* skip alnum */
1262
1263         case 'n':
1264                 spec->type = FORMAT_TYPE_NRCHARS;
1265                 return ++fmt - start;
1266
1267         case '%':
1268                 spec->type = FORMAT_TYPE_PERCENT_CHAR;
1269                 return ++fmt - start;
1270
1271         /* integer number formats - set up the flags and "break" */
1272         case 'o':
1273                 spec->base = 8;
1274                 break;
1275
1276         case 'x':
1277                 spec->flags |= SMALL;
1278
1279         case 'X':
1280                 spec->base = 16;
1281                 break;
1282
1283         case 'd':
1284         case 'i':
1285                 spec->flags |= SIGN;
1286         case 'u':
1287                 break;
1288
1289         default:
1290                 spec->type = FORMAT_TYPE_INVALID;
1291                 return fmt - start;
1292         }
1293
1294         if (spec->qualifier == 'L')
1295                 spec->type = FORMAT_TYPE_LONG_LONG;
1296         else if (spec->qualifier == 'l') {
1297                 if (spec->flags & SIGN)
1298                         spec->type = FORMAT_TYPE_LONG;
1299                 else
1300                         spec->type = FORMAT_TYPE_ULONG;
1301         } else if (_tolower(spec->qualifier) == 'z') {
1302                 spec->type = FORMAT_TYPE_SIZE_T;
1303         } else if (spec->qualifier == 't') {
1304                 spec->type = FORMAT_TYPE_PTRDIFF;
1305         } else if (spec->qualifier == 'H') {
1306                 if (spec->flags & SIGN)
1307                         spec->type = FORMAT_TYPE_BYTE;
1308                 else
1309                         spec->type = FORMAT_TYPE_UBYTE;
1310         } else if (spec->qualifier == 'h') {
1311                 if (spec->flags & SIGN)
1312                         spec->type = FORMAT_TYPE_SHORT;
1313                 else
1314                         spec->type = FORMAT_TYPE_USHORT;
1315         } else {
1316                 if (spec->flags & SIGN)
1317                         spec->type = FORMAT_TYPE_INT;
1318                 else
1319                         spec->type = FORMAT_TYPE_UINT;
1320         }
1321
1322         return ++fmt - start;
1323 }
1324
1325 /**
1326  * vsnprintf - Format a string and place it in a buffer
1327  * @buf: The buffer to place the result into
1328  * @size: The size of the buffer, including the trailing null space
1329  * @fmt: The format string to use
1330  * @args: Arguments for the format string
1331  *
1332  * This function follows C99 vsnprintf, but has some extensions:
1333  * %pS output the name of a text symbol with offset
1334  * %ps output the name of a text symbol without offset
1335  * %pF output the name of a function pointer with its offset
1336  * %pf output the name of a function pointer without its offset
1337  * %pB output the name of a backtrace symbol with its offset
1338  * %pR output the address range in a struct resource with decoded flags
1339  * %pr output the address range in a struct resource with raw flags
1340  * %pM output a 6-byte MAC address with colons
1341  * %pMR output a 6-byte MAC address with colons in reversed order
1342  * %pMF output a 6-byte MAC address with dashes
1343  * %pm output a 6-byte MAC address without colons
1344  * %pmR output a 6-byte MAC address without colons in reversed order
1345  * %pI4 print an IPv4 address without leading zeros
1346  * %pi4 print an IPv4 address with leading zeros
1347  * %pI6 print an IPv6 address with colons
1348  * %pi6 print an IPv6 address without colons
1349  * %pI6c print an IPv6 address as specified by RFC 5952
1350  * %pU[bBlL] print a UUID/GUID in big or little endian using lower or upper
1351  *   case.
1352  * %*ph[CDN] a variable-length hex string with a separator (supports up to 64
1353  *           bytes of the input)
1354  * %n is ignored
1355  *
1356  * ** Please update Documentation/printk-formats.txt when making changes **
1357  *
1358  * The return value is the number of characters which would
1359  * be generated for the given input, excluding the trailing
1360  * '\0', as per ISO C99. If you want to have the exact
1361  * number of characters written into @buf as return value
1362  * (not including the trailing '\0'), use vscnprintf(). If the
1363  * return is greater than or equal to @size, the resulting
1364  * string is truncated.
1365  *
1366  * If you're not already dealing with a va_list consider using snprintf().
1367  */
1368 int vsnprintf(char *buf, size_t size, const char *fmt, va_list args)
1369 {
1370         unsigned long long num;
1371         char *str, *end;
1372         struct printf_spec spec = {0};
1373
1374         /* Reject out-of-range values early.  Large positive sizes are
1375            used for unknown buffer sizes. */
1376         if (WARN_ON_ONCE((int) size < 0))
1377                 return 0;
1378
1379         str = buf;
1380         end = buf + size;
1381
1382         /* Make sure end is always >= buf */
1383         if (end < buf) {
1384                 end = ((void *)-1);
1385                 size = end - buf;
1386         }
1387
1388         while (*fmt) {
1389                 const char *old_fmt = fmt;
1390                 int read = format_decode(fmt, &spec);
1391
1392                 fmt += read;
1393
1394                 switch (spec.type) {
1395                 case FORMAT_TYPE_NONE: {
1396                         int copy = read;
1397                         if (str < end) {
1398                                 if (copy > end - str)
1399                                         copy = end - str;
1400                                 memcpy(str, old_fmt, copy);
1401                         }
1402                         str += read;
1403                         break;
1404                 }
1405
1406                 case FORMAT_TYPE_WIDTH:
1407                         spec.field_width = va_arg(args, int);
1408                         break;
1409
1410                 case FORMAT_TYPE_PRECISION:
1411                         spec.precision = va_arg(args, int);
1412                         break;
1413
1414                 case FORMAT_TYPE_CHAR: {
1415                         char c;
1416
1417                         if (!(spec.flags & LEFT)) {
1418                                 while (--spec.field_width > 0) {
1419                                         if (str < end)
1420                                                 *str = ' ';
1421                                         ++str;
1422
1423                                 }
1424                         }
1425                         c = (unsigned char) va_arg(args, int);
1426                         if (str < end)
1427                                 *str = c;
1428                         ++str;
1429                         while (--spec.field_width > 0) {
1430                                 if (str < end)
1431                                         *str = ' ';
1432                                 ++str;
1433                         }
1434                         break;
1435                 }
1436
1437                 case FORMAT_TYPE_STR:
1438                         str = string(str, end, va_arg(args, char *), spec);
1439                         break;
1440
1441                 case FORMAT_TYPE_PTR:
1442                         str = pointer(fmt+1, str, end, va_arg(args, void *),
1443                                       spec);
1444                         while (isalnum(*fmt))
1445                                 fmt++;
1446                         break;
1447
1448                 case FORMAT_TYPE_PERCENT_CHAR:
1449                         if (str < end)
1450                                 *str = '%';
1451                         ++str;
1452                         break;
1453
1454                 case FORMAT_TYPE_INVALID:
1455                         if (str < end)
1456                                 *str = '%';
1457                         ++str;
1458                         break;
1459
1460                 case FORMAT_TYPE_NRCHARS: {
1461                         u8 qualifier = spec.qualifier;
1462
1463                         if (qualifier == 'l') {
1464                                 long *ip = va_arg(args, long *);
1465                                 *ip = (str - buf);
1466                         } else if (_tolower(qualifier) == 'z') {
1467                                 size_t *ip = va_arg(args, size_t *);
1468                                 *ip = (str - buf);
1469                         } else {
1470                                 int *ip = va_arg(args, int *);
1471                                 *ip = (str - buf);
1472                         }
1473                         break;
1474                 }
1475
1476                 default:
1477                         switch (spec.type) {
1478                         case FORMAT_TYPE_LONG_LONG:
1479                                 num = va_arg(args, long long);
1480                                 break;
1481                         case FORMAT_TYPE_ULONG:
1482                                 num = va_arg(args, unsigned long);
1483                                 break;
1484                         case FORMAT_TYPE_LONG:
1485                                 num = va_arg(args, long);
1486                                 break;
1487                         case FORMAT_TYPE_SIZE_T:
1488                                 num = va_arg(args, size_t);
1489                                 break;
1490                         case FORMAT_TYPE_PTRDIFF:
1491                                 num = va_arg(args, ptrdiff_t);
1492                                 break;
1493                         case FORMAT_TYPE_UBYTE:
1494                                 num = (unsigned char) va_arg(args, int);
1495                                 break;
1496                         case FORMAT_TYPE_BYTE:
1497                                 num = (signed char) va_arg(args, int);
1498                                 break;
1499                         case FORMAT_TYPE_USHORT:
1500                                 num = (unsigned short) va_arg(args, int);
1501                                 break;
1502                         case FORMAT_TYPE_SHORT:
1503                                 num = (short) va_arg(args, int);
1504                                 break;
1505                         case FORMAT_TYPE_INT:
1506                                 num = (int) va_arg(args, int);
1507                                 break;
1508                         default:
1509                                 num = va_arg(args, unsigned int);
1510                         }
1511
1512                         str = number(str, end, num, spec);
1513                 }
1514         }
1515
1516         if (size > 0) {
1517                 if (str < end)
1518                         *str = '\0';
1519                 else
1520                         end[-1] = '\0';
1521         }
1522
1523         /* the trailing null byte doesn't count towards the total */
1524         return str-buf;
1525
1526 }
1527 EXPORT_SYMBOL(vsnprintf);
1528
1529 /**
1530  * vscnprintf - Format a string and place it in a buffer
1531  * @buf: The buffer to place the result into
1532  * @size: The size of the buffer, including the trailing null space
1533  * @fmt: The format string to use
1534  * @args: Arguments for the format string
1535  *
1536  * The return value is the number of characters which have been written into
1537  * the @buf not including the trailing '\0'. If @size is == 0 the function
1538  * returns 0.
1539  *
1540  * If you're not already dealing with a va_list consider using scnprintf().
1541  *
1542  * See the vsnprintf() documentation for format string extensions over C99.
1543  */
1544 int vscnprintf(char *buf, size_t size, const char *fmt, va_list args)
1545 {
1546         int i;
1547
1548         i = vsnprintf(buf, size, fmt, args);
1549
1550         if (likely(i < size))
1551                 return i;
1552         if (size != 0)
1553                 return size - 1;
1554         return 0;
1555 }
1556 EXPORT_SYMBOL(vscnprintf);
1557
1558 /**
1559  * snprintf - Format a string and place it in a buffer
1560  * @buf: The buffer to place the result into
1561  * @size: The size of the buffer, including the trailing null space
1562  * @fmt: The format string to use
1563  * @...: Arguments for the format string
1564  *
1565  * The return value is the number of characters which would be
1566  * generated for the given input, excluding the trailing null,
1567  * as per ISO C99.  If the return is greater than or equal to
1568  * @size, the resulting string is truncated.
1569  *
1570  * See the vsnprintf() documentation for format string extensions over C99.
1571  */
1572 int snprintf(char *buf, size_t size, const char *fmt, ...)
1573 {
1574         va_list args;
1575         int i;
1576
1577         va_start(args, fmt);
1578         i = vsnprintf(buf, size, fmt, args);
1579         va_end(args);
1580
1581         return i;
1582 }
1583 EXPORT_SYMBOL(snprintf);
1584
1585 /**
1586  * scnprintf - Format a string and place it in a buffer
1587  * @buf: The buffer to place the result into
1588  * @size: The size of the buffer, including the trailing null space
1589  * @fmt: The format string to use
1590  * @...: Arguments for the format string
1591  *
1592  * The return value is the number of characters written into @buf not including
1593  * the trailing '\0'. If @size is == 0 the function returns 0.
1594  */
1595
1596 int scnprintf(char *buf, size_t size, const char *fmt, ...)
1597 {
1598         va_list args;
1599         int i;
1600
1601         va_start(args, fmt);
1602         i = vscnprintf(buf, size, fmt, args);
1603         va_end(args);
1604
1605         return i;
1606 }
1607 EXPORT_SYMBOL(scnprintf);
1608
1609 /**
1610  * vsprintf - Format a string and place it in a buffer
1611  * @buf: The buffer to place the result into
1612  * @fmt: The format string to use
1613  * @args: Arguments for the format string
1614  *
1615  * The function returns the number of characters written
1616  * into @buf. Use vsnprintf() or vscnprintf() in order to avoid
1617  * buffer overflows.
1618  *
1619  * If you're not already dealing with a va_list consider using sprintf().
1620  *
1621  * See the vsnprintf() documentation for format string extensions over C99.
1622  */
1623 int vsprintf(char *buf, const char *fmt, va_list args)
1624 {
1625         return vsnprintf(buf, INT_MAX, fmt, args);
1626 }
1627 EXPORT_SYMBOL(vsprintf);
1628
1629 /**
1630  * sprintf - Format a string and place it in a buffer
1631  * @buf: The buffer to place the result into
1632  * @fmt: The format string to use
1633  * @...: Arguments for the format string
1634  *
1635  * The function returns the number of characters written
1636  * into @buf. Use snprintf() or scnprintf() in order to avoid
1637  * buffer overflows.
1638  *
1639  * See the vsnprintf() documentation for format string extensions over C99.
1640  */
1641 int sprintf(char *buf, const char *fmt, ...)
1642 {
1643         va_list args;
1644         int i;
1645
1646         va_start(args, fmt);
1647         i = vsnprintf(buf, INT_MAX, fmt, args);
1648         va_end(args);
1649
1650         return i;
1651 }
1652 EXPORT_SYMBOL(sprintf);
1653
1654 #ifdef CONFIG_BINARY_PRINTF
1655 /*
1656  * bprintf service:
1657  * vbin_printf() - VA arguments to binary data
1658  * bstr_printf() - Binary data to text string
1659  */
1660
1661 /**
1662  * vbin_printf - Parse a format string and place args' binary value in a buffer
1663  * @bin_buf: The buffer to place args' binary value
1664  * @size: The size of the buffer(by words(32bits), not characters)
1665  * @fmt: The format string to use
1666  * @args: Arguments for the format string
1667  *
1668  * The format follows C99 vsnprintf, except %n is ignored, and its argument
1669  * is skiped.
1670  *
1671  * The return value is the number of words(32bits) which would be generated for
1672  * the given input.
1673  *
1674  * NOTE:
1675  * If the return value is greater than @size, the resulting bin_buf is NOT
1676  * valid for bstr_printf().
1677  */
1678 int vbin_printf(u32 *bin_buf, size_t size, const char *fmt, va_list args)
1679 {
1680         struct printf_spec spec = {0};
1681         char *str, *end;
1682
1683         str = (char *)bin_buf;
1684         end = (char *)(bin_buf + size);
1685
1686 #define save_arg(type)                                                  \
1687 do {                                                                    \
1688         if (sizeof(type) == 8) {                                        \
1689                 unsigned long long value;                               \
1690                 str = PTR_ALIGN(str, sizeof(u32));                      \
1691                 value = va_arg(args, unsigned long long);               \
1692                 if (str + sizeof(type) <= end) {                        \
1693                         *(u32 *)str = *(u32 *)&value;                   \
1694                         *(u32 *)(str + 4) = *((u32 *)&value + 1);       \
1695                 }                                                       \
1696         } else {                                                        \
1697                 unsigned long value;                                    \
1698                 str = PTR_ALIGN(str, sizeof(type));                     \
1699                 value = va_arg(args, int);                              \
1700                 if (str + sizeof(type) <= end)                          \
1701                         *(typeof(type) *)str = (type)value;             \
1702         }                                                               \
1703         str += sizeof(type);                                            \
1704 } while (0)
1705
1706         while (*fmt) {
1707                 int read = format_decode(fmt, &spec);
1708
1709                 fmt += read;
1710
1711                 switch (spec.type) {
1712                 case FORMAT_TYPE_NONE:
1713                 case FORMAT_TYPE_INVALID:
1714                 case FORMAT_TYPE_PERCENT_CHAR:
1715                         break;
1716
1717                 case FORMAT_TYPE_WIDTH:
1718                 case FORMAT_TYPE_PRECISION:
1719                         save_arg(int);
1720                         break;
1721
1722                 case FORMAT_TYPE_CHAR:
1723                         save_arg(char);
1724                         break;
1725
1726                 case FORMAT_TYPE_STR: {
1727                         const char *save_str = va_arg(args, char *);
1728                         size_t len;
1729
1730                         if ((unsigned long)save_str > (unsigned long)-PAGE_SIZE
1731                                         || (unsigned long)save_str < PAGE_SIZE)
1732                                 save_str = "(null)";
1733                         len = strlen(save_str) + 1;
1734                         if (str + len < end)
1735                                 memcpy(str, save_str, len);
1736                         str += len;
1737                         break;
1738                 }
1739
1740                 case FORMAT_TYPE_PTR:
1741                         save_arg(void *);
1742                         /* skip all alphanumeric pointer suffixes */
1743                         while (isalnum(*fmt))
1744                                 fmt++;
1745                         break;
1746
1747                 case FORMAT_TYPE_NRCHARS: {
1748                         /* skip %n 's argument */
1749                         u8 qualifier = spec.qualifier;
1750                         void *skip_arg;
1751                         if (qualifier == 'l')
1752                                 skip_arg = va_arg(args, long *);
1753                         else if (_tolower(qualifier) == 'z')
1754                                 skip_arg = va_arg(args, size_t *);
1755                         else
1756                                 skip_arg = va_arg(args, int *);
1757                         break;
1758                 }
1759
1760                 default:
1761                         switch (spec.type) {
1762
1763                         case FORMAT_TYPE_LONG_LONG:
1764                                 save_arg(long long);
1765                                 break;
1766                         case FORMAT_TYPE_ULONG:
1767                         case FORMAT_TYPE_LONG:
1768                                 save_arg(unsigned long);
1769                                 break;
1770                         case FORMAT_TYPE_SIZE_T:
1771                                 save_arg(size_t);
1772                                 break;
1773                         case FORMAT_TYPE_PTRDIFF:
1774                                 save_arg(ptrdiff_t);
1775                                 break;
1776                         case FORMAT_TYPE_UBYTE:
1777                         case FORMAT_TYPE_BYTE:
1778                                 save_arg(char);
1779                                 break;
1780                         case FORMAT_TYPE_USHORT:
1781                         case FORMAT_TYPE_SHORT:
1782                                 save_arg(short);
1783                                 break;
1784                         default:
1785                                 save_arg(int);
1786                         }
1787                 }
1788         }
1789
1790         return (u32 *)(PTR_ALIGN(str, sizeof(u32))) - bin_buf;
1791 #undef save_arg
1792 }
1793 EXPORT_SYMBOL_GPL(vbin_printf);
1794
1795 /**
1796  * bstr_printf - Format a string from binary arguments and place it in a buffer
1797  * @buf: The buffer to place the result into
1798  * @size: The size of the buffer, including the trailing null space
1799  * @fmt: The format string to use
1800  * @bin_buf: Binary arguments for the format string
1801  *
1802  * This function like C99 vsnprintf, but the difference is that vsnprintf gets
1803  * arguments from stack, and bstr_printf gets arguments from @bin_buf which is
1804  * a binary buffer that generated by vbin_printf.
1805  *
1806  * The format follows C99 vsnprintf, but has some extensions:
1807  *  see vsnprintf comment for details.
1808  *
1809  * The return value is the number of characters which would
1810  * be generated for the given input, excluding the trailing
1811  * '\0', as per ISO C99. If you want to have the exact
1812  * number of characters written into @buf as return value
1813  * (not including the trailing '\0'), use vscnprintf(). If the
1814  * return is greater than or equal to @size, the resulting
1815  * string is truncated.
1816  */
1817 int bstr_printf(char *buf, size_t size, const char *fmt, const u32 *bin_buf)
1818 {
1819         struct printf_spec spec = {0};
1820         char *str, *end;
1821         const char *args = (const char *)bin_buf;
1822
1823         if (WARN_ON_ONCE((int) size < 0))
1824                 return 0;
1825
1826         str = buf;
1827         end = buf + size;
1828
1829 #define get_arg(type)                                                   \
1830 ({                                                                      \
1831         typeof(type) value;                                             \
1832         if (sizeof(type) == 8) {                                        \
1833                 args = PTR_ALIGN(args, sizeof(u32));                    \
1834                 *(u32 *)&value = *(u32 *)args;                          \
1835                 *((u32 *)&value + 1) = *(u32 *)(args + 4);              \
1836         } else {                                                        \
1837                 args = PTR_ALIGN(args, sizeof(type));                   \
1838                 value = *(typeof(type) *)args;                          \
1839         }                                                               \
1840         args += sizeof(type);                                           \
1841         value;                                                          \
1842 })
1843
1844         /* Make sure end is always >= buf */
1845         if (end < buf) {
1846                 end = ((void *)-1);
1847                 size = end - buf;
1848         }
1849
1850         while (*fmt) {
1851                 const char *old_fmt = fmt;
1852                 int read = format_decode(fmt, &spec);
1853
1854                 fmt += read;
1855
1856                 switch (spec.type) {
1857                 case FORMAT_TYPE_NONE: {
1858                         int copy = read;
1859                         if (str < end) {
1860                                 if (copy > end - str)
1861                                         copy = end - str;
1862                                 memcpy(str, old_fmt, copy);
1863                         }
1864                         str += read;
1865                         break;
1866                 }
1867
1868                 case FORMAT_TYPE_WIDTH:
1869                         spec.field_width = get_arg(int);
1870                         break;
1871
1872                 case FORMAT_TYPE_PRECISION:
1873                         spec.precision = get_arg(int);
1874                         break;
1875
1876                 case FORMAT_TYPE_CHAR: {
1877                         char c;
1878
1879                         if (!(spec.flags & LEFT)) {
1880                                 while (--spec.field_width > 0) {
1881                                         if (str < end)
1882                                                 *str = ' ';
1883                                         ++str;
1884                                 }
1885                         }
1886                         c = (unsigned char) get_arg(char);
1887                         if (str < end)
1888                                 *str = c;
1889                         ++str;
1890                         while (--spec.field_width > 0) {
1891                                 if (str < end)
1892                                         *str = ' ';
1893                                 ++str;
1894                         }
1895                         break;
1896                 }
1897
1898                 case FORMAT_TYPE_STR: {
1899                         const char *str_arg = args;
1900                         args += strlen(str_arg) + 1;
1901                         str = string(str, end, (char *)str_arg, spec);
1902                         break;
1903                 }
1904
1905                 case FORMAT_TYPE_PTR:
1906                         str = pointer(fmt+1, str, end, get_arg(void *), spec);
1907                         while (isalnum(*fmt))
1908                                 fmt++;
1909                         break;
1910
1911                 case FORMAT_TYPE_PERCENT_CHAR:
1912                 case FORMAT_TYPE_INVALID:
1913                         if (str < end)
1914                                 *str = '%';
1915                         ++str;
1916                         break;
1917
1918                 case FORMAT_TYPE_NRCHARS:
1919                         /* skip */
1920                         break;
1921
1922                 default: {
1923                         unsigned long long num;
1924
1925                         switch (spec.type) {
1926
1927                         case FORMAT_TYPE_LONG_LONG:
1928                                 num = get_arg(long long);
1929                                 break;
1930                         case FORMAT_TYPE_ULONG:
1931                         case FORMAT_TYPE_LONG:
1932                                 num = get_arg(unsigned long);
1933                                 break;
1934                         case FORMAT_TYPE_SIZE_T:
1935                                 num = get_arg(size_t);
1936                                 break;
1937                         case FORMAT_TYPE_PTRDIFF:
1938                                 num = get_arg(ptrdiff_t);
1939                                 break;
1940                         case FORMAT_TYPE_UBYTE:
1941                                 num = get_arg(unsigned char);
1942                                 break;
1943                         case FORMAT_TYPE_BYTE:
1944                                 num = get_arg(signed char);
1945                                 break;
1946                         case FORMAT_TYPE_USHORT:
1947                                 num = get_arg(unsigned short);
1948                                 break;
1949                         case FORMAT_TYPE_SHORT:
1950                                 num = get_arg(short);
1951                                 break;
1952                         case FORMAT_TYPE_UINT:
1953                                 num = get_arg(unsigned int);
1954                                 break;
1955                         default:
1956                                 num = get_arg(int);
1957                         }
1958
1959                         str = number(str, end, num, spec);
1960                 } /* default: */
1961                 } /* switch(spec.type) */
1962         } /* while(*fmt) */
1963
1964         if (size > 0) {
1965                 if (str < end)
1966                         *str = '\0';
1967                 else
1968                         end[-1] = '\0';
1969         }
1970
1971 #undef get_arg
1972
1973         /* the trailing null byte doesn't count towards the total */
1974         return str - buf;
1975 }
1976 EXPORT_SYMBOL_GPL(bstr_printf);
1977
1978 /**
1979  * bprintf - Parse a format string and place args' binary value in a buffer
1980  * @bin_buf: The buffer to place args' binary value
1981  * @size: The size of the buffer(by words(32bits), not characters)
1982  * @fmt: The format string to use
1983  * @...: Arguments for the format string
1984  *
1985  * The function returns the number of words(u32) written
1986  * into @bin_buf.
1987  */
1988 int bprintf(u32 *bin_buf, size_t size, const char *fmt, ...)
1989 {
1990         va_list args;
1991         int ret;
1992
1993         va_start(args, fmt);
1994         ret = vbin_printf(bin_buf, size, fmt, args);
1995         va_end(args);
1996
1997         return ret;
1998 }
1999 EXPORT_SYMBOL_GPL(bprintf);
2000
2001 #endif /* CONFIG_BINARY_PRINTF */
2002
2003 /**
2004  * vsscanf - Unformat a buffer into a list of arguments
2005  * @buf:        input buffer
2006  * @fmt:        format of buffer
2007  * @args:       arguments
2008  */
2009 int vsscanf(const char *buf, const char *fmt, va_list args)
2010 {
2011         const char *str = buf;
2012         char *next;
2013         char digit;
2014         int num = 0;
2015         u8 qualifier;
2016         u8 base;
2017         s16 field_width;
2018         bool is_sign;
2019
2020         while (*fmt) {
2021                 /* skip any white space in format */
2022                 /* white space in format matchs any amount of
2023                  * white space, including none, in the input.
2024                  */
2025                 if (isspace(*fmt)) {
2026                         fmt = skip_spaces(++fmt);
2027                         str = skip_spaces(str);
2028                 }
2029
2030                 /* anything that is not a conversion must match exactly */
2031                 if (*fmt != '%' && *fmt) {
2032                         if (*fmt++ != *str++)
2033                                 break;
2034                         continue;
2035                 }
2036
2037                 if (!*fmt)
2038                         break;
2039                 ++fmt;
2040
2041                 /* skip this conversion.
2042                  * advance both strings to next white space
2043                  */
2044                 if (*fmt == '*') {
2045                         if (!*str)
2046                                 break;
2047                         while (!isspace(*fmt) && *fmt != '%' && *fmt)
2048                                 fmt++;
2049                         while (!isspace(*str) && *str)
2050                                 str++;
2051                         continue;
2052                 }
2053
2054                 /* get field width */
2055                 field_width = -1;
2056                 if (isdigit(*fmt))
2057                         field_width = skip_atoi(&fmt);
2058
2059                 /* get conversion qualifier */
2060                 qualifier = -1;
2061                 if (*fmt == 'h' || _tolower(*fmt) == 'l' ||
2062                     _tolower(*fmt) == 'z') {
2063                         qualifier = *fmt++;
2064                         if (unlikely(qualifier == *fmt)) {
2065                                 if (qualifier == 'h') {
2066                                         qualifier = 'H';
2067                                         fmt++;
2068                                 } else if (qualifier == 'l') {
2069                                         qualifier = 'L';
2070                                         fmt++;
2071                                 }
2072                         }
2073                 }
2074
2075                 if (!*fmt)
2076                         break;
2077
2078                 if (*fmt == 'n') {
2079                         /* return number of characters read so far */
2080                         *va_arg(args, int *) = str - buf;
2081                         ++fmt;
2082                         continue;
2083                 }
2084
2085                 if (!*str)
2086                         break;
2087
2088                 base = 10;
2089                 is_sign = 0;
2090
2091                 switch (*fmt++) {
2092                 case 'c':
2093                 {
2094                         char *s = (char *)va_arg(args, char*);
2095                         if (field_width == -1)
2096                                 field_width = 1;
2097                         do {
2098                                 *s++ = *str++;
2099                         } while (--field_width > 0 && *str);
2100                         num++;
2101                 }
2102                 continue;
2103                 case 's':
2104                 {
2105                         char *s = (char *)va_arg(args, char *);
2106                         if (field_width == -1)
2107                                 field_width = SHRT_MAX;
2108                         /* first, skip leading white space in buffer */
2109                         str = skip_spaces(str);
2110
2111                         /* now copy until next white space */
2112                         while (*str && !isspace(*str) && field_width--)
2113                                 *s++ = *str++;
2114                         *s = '\0';
2115                         num++;
2116                 }
2117                 continue;
2118                 case 'o':
2119                         base = 8;
2120                         break;
2121                 case 'x':
2122                 case 'X':
2123                         base = 16;
2124                         break;
2125                 case 'i':
2126                         base = 0;
2127                 case 'd':
2128                         is_sign = 1;
2129                 case 'u':
2130                         break;
2131                 case '%':
2132                         /* looking for '%' in str */
2133                         if (*str++ != '%')
2134                                 return num;
2135                         continue;
2136                 default:
2137                         /* invalid format; stop here */
2138                         return num;
2139                 }
2140
2141                 /* have some sort of integer conversion.
2142                  * first, skip white space in buffer.
2143                  */
2144                 str = skip_spaces(str);
2145
2146                 digit = *str;
2147                 if (is_sign && digit == '-')
2148                         digit = *(str + 1);
2149
2150                 if (!digit
2151                     || (base == 16 && !isxdigit(digit))
2152                     || (base == 10 && !isdigit(digit))
2153                     || (base == 8 && (!isdigit(digit) || digit > '7'))
2154                     || (base == 0 && !isdigit(digit)))
2155                         break;
2156
2157                 switch (qualifier) {
2158                 case 'H':       /* that's 'hh' in format */
2159                         if (is_sign) {
2160                                 signed char *s = (signed char *)va_arg(args, signed char *);
2161                                 *s = (signed char)simple_strtol(str, &next, base);
2162                         } else {
2163                                 unsigned char *s = (unsigned char *)va_arg(args, unsigned char *);
2164                                 *s = (unsigned char)simple_strtoul(str, &next, base);
2165                         }
2166                         break;
2167                 case 'h':
2168                         if (is_sign) {
2169                                 short *s = (short *)va_arg(args, short *);
2170                                 *s = (short)simple_strtol(str, &next, base);
2171                         } else {
2172                                 unsigned short *s = (unsigned short *)va_arg(args, unsigned short *);
2173                                 *s = (unsigned short)simple_strtoul(str, &next, base);
2174                         }
2175                         break;
2176                 case 'l':
2177                         if (is_sign) {
2178                                 long *l = (long *)va_arg(args, long *);
2179                                 *l = simple_strtol(str, &next, base);
2180                         } else {
2181                                 unsigned long *l = (unsigned long *)va_arg(args, unsigned long *);
2182                                 *l = simple_strtoul(str, &next, base);
2183                         }
2184                         break;
2185                 case 'L':
2186                         if (is_sign) {
2187                                 long long *l = (long long *)va_arg(args, long long *);
2188                                 *l = simple_strtoll(str, &next, base);
2189                         } else {
2190                                 unsigned long long *l = (unsigned long long *)va_arg(args, unsigned long long *);
2191                                 *l = simple_strtoull(str, &next, base);
2192                         }
2193                         break;
2194                 case 'Z':
2195                 case 'z':
2196                 {
2197                         size_t *s = (size_t *)va_arg(args, size_t *);
2198                         *s = (size_t)simple_strtoul(str, &next, base);
2199                 }
2200                 break;
2201                 default:
2202                         if (is_sign) {
2203                                 int *i = (int *)va_arg(args, int *);
2204                                 *i = (int)simple_strtol(str, &next, base);
2205                         } else {
2206                                 unsigned int *i = (unsigned int *)va_arg(args, unsigned int*);
2207                                 *i = (unsigned int)simple_strtoul(str, &next, base);
2208                         }
2209                         break;
2210                 }
2211                 num++;
2212
2213                 if (!next)
2214                         break;
2215                 str = next;
2216         }
2217
2218         return num;
2219 }
2220 EXPORT_SYMBOL(vsscanf);
2221
2222 /**
2223  * sscanf - Unformat a buffer into a list of arguments
2224  * @buf:        input buffer
2225  * @fmt:        formatting of buffer
2226  * @...:        resulting arguments
2227  */
2228 int sscanf(const char *buf, const char *fmt, ...)
2229 {
2230         va_list args;
2231         int i;
2232
2233         va_start(args, fmt);
2234         i = vsscanf(buf, fmt, args);
2235         va_end(args);
2236
2237         return i;
2238 }
2239 EXPORT_SYMBOL(sscanf);