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/math64.h>
  27 #include <linux/uaccess.h>
  28 #include <linux/ioport.h>
  29 #include <linux/dcache.h>
  30 #include <linux/cred.h>
  31 #include <net/addrconf.h>
  32
  33 #include <asm/page.h>           /* for PAGE_SIZE */
  34 #include <asm/sections.h>       /* for dereference_function_descriptor() */
  35
  36 #include "kstrtox.h"
  37
  38 /**
  39  * simple_strtoull - convert a string to an unsigned long long
  40  * @cp: The start of the string
  41  * @endp: A pointer to the end of the parsed string will be placed here
  42  * @base: The number base to use
  43  *
  44  * This function is obsolete. Please use kstrtoull instead.
  45  */
  46 unsigned long long simple_strtoull(const char *cp, char **endp, unsigned int base)
  47 {
  48         unsigned long long result;
  49         unsigned int rv;
  50
  51         cp = _parse_integer_fixup_radix(cp, &base);
  52         rv = _parse_integer(cp, base, &result);
  53         /* FIXME */
  54         cp += (rv & ~KSTRTOX_OVERFLOW);
  55
  56         if (endp)
  57                 *endp = (char *)cp;
  58
  59         return result;
  60 }
  61 EXPORT_SYMBOL(simple_strtoull);
  62
  63 /**
  64  * simple_strtoul - convert a string to an unsigned long
  65  * @cp: The start of the string
  66  * @endp: A pointer to the end of the parsed string will be placed here
  67  * @base: The number base to use
  68  *
  69  * This function is obsolete. Please use kstrtoul instead.
  70  */
  71 unsigned long simple_strtoul(const char *cp, char **endp, unsigned int base)
  72 {
  73         return simple_strtoull(cp, endp, base);
  74 }
  75 EXPORT_SYMBOL(simple_strtoul);
  76
  77 /**
  78  * simple_strtol - convert a string to a signed long
  79  * @cp: The start of the string
  80  * @endp: A pointer to the end of the parsed string will be placed here
  81  * @base: The number base to use
  82  *
  83  * This function is obsolete. Please use kstrtol instead.
  84  */
  85 long simple_strtol(const char *cp, char **endp, unsigned int base)
  86 {
  87         if (*cp == '-')
  88                 return -simple_strtoul(cp + 1, endp, base);
  89
  90         return simple_strtoul(cp, endp, base);
  91 }
  92 EXPORT_SYMBOL(simple_strtol);
  93
  94 /**
  95  * simple_strtoll - convert a string to a signed long long
  96  * @cp: The start of the string
  97  * @endp: A pointer to the end of the parsed string will be placed here
  98  * @base: The number base to use
  99  *
 100  * This function is obsolete. Please use kstrtoll instead.
 101  */
 102 long long simple_strtoll(const char *cp, char **endp, unsigned int base)
 103 {
 104         if (*cp == '-')
 105                 return -simple_strtoull(cp + 1, endp, base);
 106
 107         return simple_strtoull(cp, endp, base);
 108 }
 109 EXPORT_SYMBOL(simple_strtoll);
 110
 111 static noinline_for_stack
 112 int skip_atoi(const char **s)
 113 {
 114         int i = 0;
 115
 116         while (isdigit(**s))
 117                 i = i*10 + *((*s)++) - '0';
 118
 119         return i;
 120 }
 121
 122 /* Decimal conversion is by far the most typical, and is used
 123  * for /proc and /sys data. This directly impacts e.g. top performance
 124  * with many processes running. We optimize it for speed
 125  * using ideas described at <http://www.cs.uiowa.edu/~jones/bcd/divide.html>
 126  * (with permission from the author, Douglas W. Jones).
 127  */
 128
 129 #if BITS_PER_LONG != 32 || BITS_PER_LONG_LONG != 64
 130 /* Formats correctly any integer in [0, 999999999] */
 131 static noinline_for_stack
 132 char *put_dec_full9(char *buf, unsigned q)
 133 {
 134         unsigned r;
 135
 136         /*
 137          * Possible ways to approx. divide by 10
 138          * (x * 0x1999999a) >> 32 x < 1073741829 (multiply must be 64-bit)
 139          * (x * 0xcccd) >> 19     x <      81920 (x < 262149 when 64-bit mul)
 140          * (x * 0x6667) >> 18     x <      43699
 141          * (x * 0x3334) >> 17     x <      16389
 142          * (x * 0x199a) >> 16     x <      16389
 143          * (x * 0x0ccd) >> 15     x <      16389
 144          * (x * 0x0667) >> 14     x <       2739
 145          * (x * 0x0334) >> 13     x <       1029
 146          * (x * 0x019a) >> 12     x <       1029
 147          * (x * 0x00cd) >> 11     x <       1029 shorter code than * 0x67 (on i386)
 148          * (x * 0x0067) >> 10     x <        179
 149          * (x * 0x0034) >>  9     x <         69 same
 150          * (x * 0x001a) >>  8     x <         69 same
 151          * (x * 0x000d) >>  7     x <         69 same, shortest code (on i386)
 152          * (x * 0x0007) >>  6     x <         19
 153          * See <http://www.cs.uiowa.edu/~jones/bcd/divide.html>
 154          */
 155         r      = (q * (uint64_t)0x1999999a) >> 32;
 156         *buf++ = (q - 10 * r) + '0'; /* 1 */
 157         q      = (r * (uint64_t)0x1999999a) >> 32;
 158         *buf++ = (r - 10 * q) + '0'; /* 2 */
 159         r      = (q * (uint64_t)0x1999999a) >> 32;
 160         *buf++ = (q - 10 * r) + '0'; /* 3 */
 161         q      = (r * (uint64_t)0x1999999a) >> 32;
 162         *buf++ = (r - 10 * q) + '0'; /* 4 */
 163         r      = (q * (uint64_t)0x1999999a) >> 32;
 164         *buf++ = (q - 10 * r) + '0'; /* 5 */
 165         /* Now value is under 10000, can avoid 64-bit multiply */
 166         q      = (r * 0x199a) >> 16;
 167         *buf++ = (r - 10 * q)  + '0'; /* 6 */
 168         r      = (q * 0xcd) >> 11;
 169         *buf++ = (q - 10 * r)  + '0'; /* 7 */
 170         q      = (r * 0xcd) >> 11;
 171         *buf++ = (r - 10 * q) + '0'; /* 8 */
 172         *buf++ = q + '0'; /* 9 */
 173         return buf;
 174 }
 175 #endif
 176
 177 /* Similar to above but do not pad with zeros.
 178  * Code can be easily arranged to print 9 digits too, but our callers
 179  * always call put_dec_full9() instead when the number has 9 decimal digits.
 180  */
 181 static noinline_for_stack
 182 char *put_dec_trunc8(char *buf, unsigned r)
 183 {
 184         unsigned q;
 185
 186         /* Copy of previous function's body with added early returns */
 187         while (r >= 10000) {
 188                 q = r + '0';
 189                 r  = (r * (uint64_t)0x1999999a) >> 32;
 190                 *buf++ = q - 10*r;
 191         }
 192
 193         q      = (r * 0x199a) >> 16;    /* r <= 9999 */
 194         *buf++ = (r - 10 * q)  + '0';
 195         if (q == 0)
 196                 return buf;
 197         r      = (q * 0xcd) >> 11;      /* q <= 999 */
 198         *buf++ = (q - 10 * r)  + '0';
 199         if (r == 0)
 200                 return buf;
 201         q      = (r * 0xcd) >> 11;      /* r <= 99 */
 202         *buf++ = (r - 10 * q) + '0';
 203         if (q == 0)
 204                 return buf;
 205         *buf++ = q + '0';                /* q <= 9 */
 206         return buf;
 207 }
 208
 209 /* There are two algorithms to print larger numbers.
 210  * One is generic: divide by 1000000000 and repeatedly print
 211  * groups of (up to) 9 digits. It's conceptually simple,
 212  * but requires a (unsigned long long) / 1000000000 division.
 213  *
 214  * Second algorithm splits 64-bit unsigned long long into 16-bit chunks,
 215  * manipulates them cleverly and generates groups of 4 decimal digits.
 216  * It so happens that it does NOT require long long division.
 217  *
 218  * If long is > 32 bits, division of 64-bit values is relatively easy,
 219  * and we will use the first algorithm.
 220  * If long long is > 64 bits (strange architecture with VERY large long long),
 221  * second algorithm can't be used, and we again use the first one.
 222  *
 223  * Else (if long is 32 bits and long long is 64 bits) we use second one.
 224  */
 225
 226 #if BITS_PER_LONG != 32 || BITS_PER_LONG_LONG != 64
 227
 228 /* First algorithm: generic */
 229
 230 static
 231 char *put_dec(char *buf, unsigned long long n)
 232 {
 233         if (n >= 100*1000*1000) {
 234                 while (n >= 1000*1000*1000)
 235                         buf = put_dec_full9(buf, do_div(n, 1000*1000*1000));
 236                 if (n >= 100*1000*1000)
 237                         return put_dec_full9(buf, n);
 238         }
 239         return put_dec_trunc8(buf, n);
 240 }
 241
 242 #else
 243
 244 /* Second algorithm: valid only for 64-bit long longs */
 245
 246 /* See comment in put_dec_full9 for choice of constants */
 247 static noinline_for_stack
 248 void put_dec_full4(char *buf, unsigned q)
 249 {
 250         unsigned r;
 251         r      = (q * 0xccd) >> 15;
 252         buf[0] = (q - 10 * r) + '0';
 253         q      = (r * 0xcd) >> 11;
 254         buf[1] = (r - 10 * q)  + '0';
 255         r      = (q * 0xcd) >> 11;
 256         buf[2] = (q - 10 * r)  + '0';
 257         buf[3] = r + '0';
 258 }
 259
 260 /*
 261  * Call put_dec_full4 on x % 10000, return x / 10000.
 262  * The approximation x/10000 == (x * 0x346DC5D7) >> 43
 263  * holds for all x < 1,128,869,999.  The largest value this
 264  * helper will ever be asked to convert is 1,125,520,955.
 265  * (d1 in the put_dec code, assuming n is all-ones).
 266  */
 267 static
 268 unsigned put_dec_helper4(char *buf, unsigned x)
 269 {
 270         uint32_t q = (x * (uint64_t)0x346DC5D7) >> 43;
 271
 272         put_dec_full4(buf, x - q * 10000);
 273         return q;
 274 }
 275
 276 /* Based on code by Douglas W. Jones found at
 277  * <http://www.cs.uiowa.edu/~jones/bcd/decimal.html#sixtyfour>
 278  * (with permission from the author).
 279  * Performs no 64-bit division and hence should be fast on 32-bit machines.
 280  */
 281 static
 282 char *put_dec(char *buf, unsigned long long n)
 283 {
 284         uint32_t d3, d2, d1, q, h;
 285
 286         if (n < 100*1000*1000)
 287                 return put_dec_trunc8(buf, n);
 288
 289         d1  = ((uint32_t)n >> 16); /* implicit "& 0xffff" */
 290         h   = (n >> 32);
 291         d2  = (h      ) & 0xffff;
 292         d3  = (h >> 16); /* implicit "& 0xffff" */
 293
 294         q   = 656 * d3 + 7296 * d2 + 5536 * d1 + ((uint32_t)n & 0xffff);
 295         q = put_dec_helper4(buf, q);
 296
 297         q += 7671 * d3 + 9496 * d2 + 6 * d1;
 298         q = put_dec_helper4(buf+4, q);
 299
 300         q += 4749 * d3 + 42 * d2;
 301         q = put_dec_helper4(buf+8, q);
 302
 303         q += 281 * d3;
 304         buf += 12;
 305         if (q)
 306                 buf = put_dec_trunc8(buf, q);
 307         else while (buf[-1] == '0')
 308                 --buf;
 309
 310         return buf;
 311 }
 312
 313 #endif
 314
 315 /*
 316  * Convert passed number to decimal string.
 317  * Returns the length of string.  On buffer overflow, returns 0.
 318  *
 319  * If speed is not important, use snprintf(). It's easy to read the code.
 320  */
 321 int num_to_str(char *buf, int size, unsigned long long num)
 322 {
 323         char tmp[sizeof(num) * 3];
 324         int idx, len;
 325
 326         /* put_dec() may work incorrectly for num = 0 (generate "", not "0") */
 327         if (num <= 9) {
 328                 tmp[0] = '0' + num;
 329                 len = 1;
 330         } else {
 331                 len = put_dec(tmp, num) - tmp;
 332         }
 333
 334         if (len > size)
 335                 return 0;
 336         for (idx = 0; idx < len; ++idx)
 337                 buf[idx] = tmp[len - idx - 1];
 338         return len;
 339 }
 340
 341 #define ZEROPAD 1               /* pad with zero */
 342 #define SIGN    2               /* unsigned/signed long */
 343 #define PLUS    4               /* show plus */
 344 #define SPACE   8               /* space if plus */
 345 #define LEFT    16              /* left justified */
 346 #define SMALL   32              /* use lowercase in hex (must be 32 == 0x20) */
 347 #define SPECIAL 64              /* prefix hex with "0x", octal with "0" */
 348
 349 enum format_type {
 350         FORMAT_TYPE_NONE, /* Just a string part */
 351         FORMAT_TYPE_WIDTH,
 352         FORMAT_TYPE_PRECISION,
 353         FORMAT_TYPE_CHAR,
 354         FORMAT_TYPE_STR,
 355         FORMAT_TYPE_PTR,
 356         FORMAT_TYPE_PERCENT_CHAR,
 357         FORMAT_TYPE_INVALID,
 358         FORMAT_TYPE_LONG_LONG,
 359         FORMAT_TYPE_ULONG,
 360         FORMAT_TYPE_LONG,
 361         FORMAT_TYPE_UBYTE,
 362         FORMAT_TYPE_BYTE,
 363         FORMAT_TYPE_USHORT,
 364         FORMAT_TYPE_SHORT,
 365         FORMAT_TYPE_UINT,
 366         FORMAT_TYPE_INT,
 367         FORMAT_TYPE_SIZE_T,
 368         FORMAT_TYPE_PTRDIFF
 369 };
 370
 371 struct printf_spec {
 372         u8      type;           /* format_type enum */
 373         u8      flags;          /* flags to number() */
 374         u8      base;           /* number base, 8, 10 or 16 only */
 375         u8      qualifier;      /* number qualifier, one of 'hHlLtzZ' */
 376         s16     field_width;    /* width of output field */
 377         s16     precision;      /* # of digits/chars */
 378 };
 379
 380 static noinline_for_stack
 381 char *number(char *buf, char *end, unsigned long long num,
 382              struct printf_spec spec)
 383 {
 384         /* we are called with base 8, 10 or 16, only, thus don't need "G..."  */
 385         static const char digits[16] = "0123456789ABCDEF"; /* "GHIJKLMNOPQRSTUVWXYZ"; */
 386
 387         char tmp[66];
 388         char sign;
 389         char locase;
 390         int need_pfx = ((spec.flags & SPECIAL) && spec.base != 10);
 391         int i;
 392         bool is_zero = num == 0LL;
 393
 394         /* locase = 0 or 0x20. ORing digits or letters with 'locase'
 395          * produces same digits or (maybe lowercased) letters */
 396         locase = (spec.flags & SMALL);
 397         if (spec.flags & LEFT)
 398                 spec.flags &= ~ZEROPAD;
 399         sign = 0;
 400         if (spec.flags & SIGN) {
 401                 if ((signed long long)num < 0) {
 402                         sign = '-';
 403                         num = -(signed long long)num;
 404                         spec.field_width--;
 405                 } else if (spec.flags & PLUS) {
 406                         sign = '+';
 407                         spec.field_width--;
 408                 } else if (spec.flags & SPACE) {
 409                         sign = ' ';
 410                         spec.field_width--;
 411                 }
 412         }
 413         if (need_pfx) {
 414                 if (spec.base == 16)
 415                         spec.field_width -= 2;
 416                 else if (!is_zero)
 417                         spec.field_width--;
 418         }
 419
 420         /* generate full string in tmp[], in reverse order */
 421         i = 0;
 422         if (num < spec.base)
 423                 tmp[i++] = digits[num] | locase;
 424         /* Generic code, for any base:
 425         else do {
 426                 tmp[i++] = (digits[do_div(num,base)] | locase);
 427         } while (num != 0);
 428         */
 429         else if (spec.base != 10) { /* 8 or 16 */
 430                 int mask = spec.base - 1;
 431                 int shift = 3;
 432
 433                 if (spec.base == 16)
 434                         shift = 4;
 435                 do {
 436                         tmp[i++] = (digits[((unsigned char)num) & mask] | locase);
 437                         num >>= shift;
 438                 } while (num);
 439         } else { /* base 10 */
 440                 i = put_dec(tmp, num) - tmp;
 441         }
 442
 443         /* printing 100 using %2d gives "100", not "00" */
 444         if (i > spec.precision)
 445                 spec.precision = i;
 446         /* leading space padding */
 447         spec.field_width -= spec.precision;
 448         if (!(spec.flags & (ZEROPAD+LEFT))) {
 449                 while (--spec.field_width >= 0) {
 450                         if (buf < end)
 451                                 *buf = ' ';
 452                         ++buf;
 453                 }
 454         }
 455         /* sign */
 456         if (sign) {
 457                 if (buf < end)
 458                         *buf = sign;
 459                 ++buf;
 460         }
 461         /* "0x" / "0" prefix */
 462         if (need_pfx) {
 463                 if (spec.base == 16 || !is_zero) {
 464                         if (buf < end)
 465                                 *buf = '0';
 466                         ++buf;
 467                 }
 468                 if (spec.base == 16) {
 469                         if (buf < end)
 470                                 *buf = ('X' | locase);
 471                         ++buf;
 472                 }
 473         }
 474         /* zero or space padding */
 475         if (!(spec.flags & LEFT)) {
 476                 char c = (spec.flags & ZEROPAD) ? '0' : ' ';
 477                 while (--spec.field_width >= 0) {
 478                         if (buf < end)
 479                                 *buf = c;
 480                         ++buf;
 481                 }
 482         }
 483         /* hmm even more zero padding? */
 484         while (i <= --spec.precision) {
 485                 if (buf < end)
 486                         *buf = '0';
 487                 ++buf;
 488         }
 489         /* actual digits of result */
 490         while (--i >= 0) {
 491                 if (buf < end)
 492                         *buf = tmp[i];
 493                 ++buf;
 494         }
 495         /* trailing space padding */
 496         while (--spec.field_width >= 0) {
 497                 if (buf < end)
 498                         *buf = ' ';
 499                 ++buf;
 500         }
 501
 502         return buf;
 503 }
 504
 505 static noinline_for_stack
 506 char *string(char *buf, char *end, const char *s, struct printf_spec spec)
 507 {
 508         int len, i;
 509
 510         if ((unsigned long)s < PAGE_SIZE)
 511                 s = "(null)";
 512
 513         len = strnlen(s, spec.precision);
 514
 515         if (!(spec.flags & LEFT)) {
 516                 while (len < spec.field_width--) {
 517                         if (buf < end)
 518                                 *buf = ' ';
 519                         ++buf;
 520                 }
 521         }
 522         for (i = 0; i < len; ++i) {
 523                 if (buf < end)
 524                         *buf = *s;
 525                 ++buf; ++s;
 526         }
 527         while (len < spec.field_width--) {
 528                 if (buf < end)
 529                         *buf = ' ';
 530                 ++buf;
 531         }
 532
 533         return buf;
 534 }
 535
 536 static void widen(char *buf, char *end, unsigned len, unsigned spaces)
 537 {
 538         size_t size;
 539         if (buf >= end) /* nowhere to put anything */
 540                 return;
 541         size = end - buf;
 542         if (size <= spaces) {
 543                 memset(buf, ' ', size);
 544                 return;
 545         }
 546         if (len) {
 547                 if (len > size - spaces)
 548                         len = size - spaces;
 549                 memmove(buf + spaces, buf, len);
 550         }
 551         memset(buf, ' ', spaces);
 552 }
 553
 554 static noinline_for_stack
 555 char *dentry_name(char *buf, char *end, const struct dentry *d, struct printf_spec spec,
 556                   const char *fmt)
 557 {
 558         const char *array[4], *s;
 559         const struct dentry *p;
 560         int depth;
 561         int i, n;
 562
 563         switch (fmt[1]) {
 564                 case '2': case '3': case '4':
 565                         depth = fmt[1] - '0';
 566                         break;
 567                 default:
 568                         depth = 1;
 569         }
 570
 571         rcu_read_lock();
 572         for (i = 0; i < depth; i++, d = p) {
 573                 p = ACCESS_ONCE(d->d_parent);
 574                 array[i] = ACCESS_ONCE(d->d_name.name);
 575                 if (p == d) {
 576                         if (i)
 577                                 array[i] = "";
 578                         i++;
 579                         break;
 580                 }
 581         }
 582         s = array[--i];
 583         for (n = 0; n != spec.precision; n++, buf++) {
 584                 char c = *s++;
 585                 if (!c) {
 586                         if (!i)
 587                                 break;
 588                         c = '/';
 589                         s = array[--i];
 590                 }
 591                 if (buf < end)
 592                         *buf = c;
 593         }
 594         rcu_read_unlock();
 595         if (n < spec.field_width) {
 596                 /* we want to pad the sucker */
 597                 unsigned spaces = spec.field_width - n;
 598                 if (!(spec.flags & LEFT)) {
 599                         widen(buf - n, end, n, spaces);
 600                         return buf + spaces;
 601                 }
 602                 while (spaces--) {
 603                         if (buf < end)
 604                                 *buf = ' ';
 605                         ++buf;
 606                 }
 607         }
 608         return buf;
 609 }
 610
 611 static noinline_for_stack
 612 char *symbol_string(char *buf, char *end, void *ptr,
 613                     struct printf_spec spec, const char *fmt)
 614 {
 615         unsigned long value;
 616 #ifdef CONFIG_KALLSYMS
 617         char sym[KSYM_SYMBOL_LEN];
 618 #endif
 619
 620         if (fmt[1] == 'R')
 621                 ptr = __builtin_extract_return_addr(ptr);
 622         value = (unsigned long)ptr;
 623
 624 #ifdef CONFIG_KALLSYMS
 625         if (*fmt == 'B')
 626                 sprint_backtrace(sym, value);
 627         else if (*fmt != 'f' && *fmt != 's')
 628                 sprint_symbol(sym, value);
 629         else
 630                 sprint_symbol_no_offset(sym, value);
 631
 632         return string(buf, end, sym, spec);
 633 #else
 634         spec.field_width = 2 * sizeof(void *);
 635         spec.flags |= SPECIAL | SMALL | ZEROPAD;
 636         spec.base = 16;
 637
 638         return number(buf, end, value, spec);
 639 #endif
 640 }
 641
 642 static noinline_for_stack
 643 char *resource_string(char *buf, char *end, struct resource *res,
 644                       struct printf_spec spec, const char *fmt)
 645 {
 646 #ifndef IO_RSRC_PRINTK_SIZE
 647 #define IO_RSRC_PRINTK_SIZE     6
 648 #endif
 649
 650 #ifndef MEM_RSRC_PRINTK_SIZE
 651 #define MEM_RSRC_PRINTK_SIZE    10
 652 #endif
 653         static const struct printf_spec io_spec = {
 654                 .base = 16,
 655                 .field_width = IO_RSRC_PRINTK_SIZE,
 656                 .precision = -1,
 657                 .flags = SPECIAL | SMALL | ZEROPAD,
 658         };
 659         static const struct printf_spec mem_spec = {
 660                 .base = 16,
 661                 .field_width = MEM_RSRC_PRINTK_SIZE,
 662                 .precision = -1,
 663                 .flags = SPECIAL | SMALL | ZEROPAD,
 664         };
 665         static const struct printf_spec bus_spec = {
 666                 .base = 16,
 667                 .field_width = 2,
 668                 .precision = -1,
 669                 .flags = SMALL | ZEROPAD,
 670         };
 671         static const struct printf_spec dec_spec = {
 672                 .base = 10,
 673                 .precision = -1,
 674                 .flags = 0,
 675         };
 676         static const struct printf_spec str_spec = {
 677                 .field_width = -1,
 678                 .precision = 10,
 679                 .flags = LEFT,
 680         };
 681         static const struct printf_spec flag_spec = {
 682                 .base = 16,
 683                 .precision = -1,
 684                 .flags = SPECIAL | SMALL,
 685         };
 686
 687         /* 32-bit res (sizeof==4): 10 chars in dec, 10 in hex ("0x" + 8)
 688          * 64-bit res (sizeof==8): 20 chars in dec, 18 in hex ("0x" + 16) */
 689 #define RSRC_BUF_SIZE           ((2 * sizeof(resource_size_t)) + 4)
 690 #define FLAG_BUF_SIZE           (2 * sizeof(res->flags))
 691 #define DECODED_BUF_SIZE        sizeof("[mem - 64bit pref window disabled]")
 692 #define RAW_BUF_SIZE            sizeof("[mem - flags 0x]")
 693         char sym[max(2*RSRC_BUF_SIZE + DECODED_BUF_SIZE,
 694                      2*RSRC_BUF_SIZE + FLAG_BUF_SIZE + RAW_BUF_SIZE)];
 695
 696         char *p = sym, *pend = sym + sizeof(sym);
 697         int decode = (fmt[0] == 'R') ? 1 : 0;
 698         const struct printf_spec *specp;
 699
 700         *p++ = '[';
 701         if (res->flags & IORESOURCE_IO) {
 702                 p = string(p, pend, "io  ", str_spec);
 703                 specp = &io_spec;
 704         } else if (res->flags & IORESOURCE_MEM) {
 705                 p = string(p, pend, "mem ", str_spec);
 706                 specp = &mem_spec;
 707         } else if (res->flags & IORESOURCE_IRQ) {
 708                 p = string(p, pend, "irq ", str_spec);
 709                 specp = &dec_spec;
 710         } else if (res->flags & IORESOURCE_DMA) {
 711                 p = string(p, pend, "dma ", str_spec);
 712                 specp = &dec_spec;
 713         } else if (res->flags & IORESOURCE_BUS) {
 714                 p = string(p, pend, "bus ", str_spec);
 715                 specp = &bus_spec;
 716         } else {
 717                 p = string(p, pend, "??? ", str_spec);
 718                 specp = &mem_spec;
 719                 decode = 0;
 720         }
 721         if (decode && res->flags & IORESOURCE_UNSET) {
 722                 p = string(p, pend, "size ", str_spec);
 723                 p = number(p, pend, resource_size(res), *specp);
 724         } else {
 725                 p = number(p, pend, res->start, *specp);
 726                 if (res->start != res->end) {
 727                         *p++ = '-';
 728                         p = number(p, pend, res->end, *specp);
 729                 }
 730         }
 731         if (decode) {
 732                 if (res->flags & IORESOURCE_MEM_64)
 733                         p = string(p, pend, " 64bit", str_spec);
 734                 if (res->flags & IORESOURCE_PREFETCH)
 735                         p = string(p, pend, " pref", str_spec);
 736                 if (res->flags & IORESOURCE_WINDOW)
 737                         p = string(p, pend, " window", str_spec);
 738                 if (res->flags & IORESOURCE_DISABLED)
 739                         p = string(p, pend, " disabled", str_spec);
 740         } else {
 741                 p = string(p, pend, " flags ", str_spec);
 742                 p = number(p, pend, res->flags, flag_spec);
 743         }
 744         *p++ = ']';
 745         *p = '\0';
 746
 747         return string(buf, end, sym, spec);
 748 }
 749
 750 static noinline_for_stack
 751 char *hex_string(char *buf, char *end, u8 *addr, struct printf_spec spec,
 752                  const char *fmt)
 753 {
 754         int i, len = 1;         /* if we pass '%ph[CDN]', field width remains
 755                                    negative value, fallback to the default */
 756         char separator;
 757
 758         if (spec.field_width == 0)
 759                 /* nothing to print */
 760                 return buf;
 761
 762         if (ZERO_OR_NULL_PTR(addr))
 763                 /* NULL pointer */
 764                 return string(buf, end, NULL, spec);
 765
 766         switch (fmt[1]) {
 767         case 'C':
 768                 separator = ':';
 769                 break;
 770         case 'D':
 771                 separator = '-';
 772                 break;
 773         case 'N':
 774                 separator = 0;
 775                 break;
 776         default:
 777                 separator = ' ';
 778                 break;
 779         }
 780
 781         if (spec.field_width > 0)
 782                 len = min_t(int, spec.field_width, 64);
 783
 784         for (i = 0; i < len && buf < end - 1; i++) {
 785                 buf = hex_byte_pack(buf, addr[i]);
 786
 787                 if (buf < end && separator && i != len - 1)
 788                         *buf++ = separator;
 789         }
 790
 791         return buf;
 792 }
 793
 794 static noinline_for_stack
 795 char *mac_address_string(char *buf, char *end, u8 *addr,
 796                          struct printf_spec spec, const char *fmt)
 797 {
 798         char mac_addr[sizeof("xx:xx:xx:xx:xx:xx")];
 799         char *p = mac_addr;
 800         int i;
 801         char separator;
 802         bool reversed = false;
 803
 804         switch (fmt[1]) {
 805         case 'F':
 806                 separator = '-';
 807                 break;
 808
 809         case 'R':
 810                 reversed = true;
 811                 /* fall through */
 812
 813         default:
 814                 separator = ':';
 815                 break;
 816         }
 817
 818         for (i = 0; i < 6; i++) {
 819                 if (reversed)
 820                         p = hex_byte_pack(p, addr[5 - i]);
 821                 else
 822                         p = hex_byte_pack(p, addr[i]);
 823
 824                 if (fmt[0] == 'M' && i != 5)
 825                         *p++ = separator;
 826         }
 827         *p = '\0';
 828
 829         return string(buf, end, mac_addr, spec);
 830 }
 831
 832 static noinline_for_stack
 833 char *ip4_string(char *p, const u8 *addr, const char *fmt)
 834 {
 835         int i;
 836         bool leading_zeros = (fmt[0] == 'i');
 837         int index;
 838         int step;
 839
 840         switch (fmt[2]) {
 841         case 'h':
 842 #ifdef __BIG_ENDIAN
 843                 index = 0;
 844                 step = 1;
 845 #else
 846                 index = 3;
 847                 step = -1;
 848 #endif
 849                 break;
 850         case 'l':
 851                 index = 3;
 852                 step = -1;
 853                 break;
 854         case 'n':
 855         case 'b':
 856         default:
 857                 index = 0;
 858                 step = 1;
 859                 break;
 860         }
 861         for (i = 0; i < 4; i++) {
 862                 char temp[3];   /* hold each IP quad in reverse order */
 863                 int digits = put_dec_trunc8(temp, addr[index]) - temp;
 864                 if (leading_zeros) {
 865                         if (digits < 3)
 866                                 *p++ = '0';
 867                         if (digits < 2)
 868                                 *p++ = '0';
 869                 }
 870                 /* reverse the digits in the quad */
 871                 while (digits--)
 872                         *p++ = temp[digits];
 873                 if (i < 3)
 874                         *p++ = '.';
 875                 index += step;
 876         }
 877         *p = '\0';
 878
 879         return p;
 880 }
 881
 882 static noinline_for_stack
 883 char *ip6_compressed_string(char *p, const char *addr)
 884 {
 885         int i, j, range;
 886         unsigned char zerolength[8];
 887         int longest = 1;
 888         int colonpos = -1;
 889         u16 word;
 890         u8 hi, lo;
 891         bool needcolon = false;
 892         bool useIPv4;
 893         struct in6_addr in6;
 894
 895         memcpy(&in6, addr, sizeof(struct in6_addr));
 896
 897         useIPv4 = ipv6_addr_v4mapped(&in6) || ipv6_addr_is_isatap(&in6);
 898
 899         memset(zerolength, 0, sizeof(zerolength));
 900
 901         if (useIPv4)
 902                 range = 6;
 903         else
 904                 range = 8;
 905
 906         /* find position of longest 0 run */
 907         for (i = 0; i < range; i++) {
 908                 for (j = i; j < range; j++) {
 909                         if (in6.s6_addr16[j] != 0)
 910                                 break;
 911                         zerolength[i]++;
 912                 }
 913         }
 914         for (i = 0; i < range; i++) {
 915                 if (zerolength[i] > longest) {
 916                         longest = zerolength[i];
 917                         colonpos = i;
 918                 }
 919         }
 920         if (longest == 1)               /* don't compress a single 0 */
 921                 colonpos = -1;
 922
 923         /* emit address */
 924         for (i = 0; i < range; i++) {
 925                 if (i == colonpos) {
 926                         if (needcolon || i == 0)
 927                                 *p++ = ':';
 928                         *p++ = ':';
 929                         needcolon = false;
 930                         i += longest - 1;
 931                         continue;
 932                 }
 933                 if (needcolon) {
 934                         *p++ = ':';
 935                         needcolon = false;
 936                 }
 937                 /* hex u16 without leading 0s */
 938                 word = ntohs(in6.s6_addr16[i]);
 939                 hi = word >> 8;
 940                 lo = word & 0xff;
 941                 if (hi) {
 942                         if (hi > 0x0f)
 943                                 p = hex_byte_pack(p, hi);
 944                         else
 945                                 *p++ = hex_asc_lo(hi);
 946                         p = hex_byte_pack(p, lo);
 947                 }
 948                 else if (lo > 0x0f)
 949                         p = hex_byte_pack(p, lo);
 950                 else
 951                         *p++ = hex_asc_lo(lo);
 952                 needcolon = true;
 953         }
 954
 955         if (useIPv4) {
 956                 if (needcolon)
 957                         *p++ = ':';
 958                 p = ip4_string(p, &in6.s6_addr[12], "I4");
 959         }
 960         *p = '\0';
 961
 962         return p;
 963 }
 964
 965 static noinline_for_stack
 966 char *ip6_string(char *p, const char *addr, const char *fmt)
 967 {
 968         int i;
 969
 970         for (i = 0; i < 8; i++) {
 971                 p = hex_byte_pack(p, *addr++);
 972                 p = hex_byte_pack(p, *addr++);
 973                 if (fmt[0] == 'I' && i != 7)
 974                         *p++ = ':';
 975         }
 976         *p = '\0';
 977
 978         return p;
 979 }
 980
 981 static noinline_for_stack
 982 char *ip6_addr_string(char *buf, char *end, const u8 *addr,
 983                       struct printf_spec spec, const char *fmt)
 984 {
 985         char ip6_addr[sizeof("xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255")];
 986
 987         if (fmt[0] == 'I' && fmt[2] == 'c')
 988                 ip6_compressed_string(ip6_addr, addr);
 989         else
 990                 ip6_string(ip6_addr, addr, fmt);
 991
 992         return string(buf, end, ip6_addr, spec);
 993 }
 994
 995 static noinline_for_stack
 996 char *ip4_addr_string(char *buf, char *end, const u8 *addr,
 997                       struct printf_spec spec, const char *fmt)
 998 {
 999         char ip4_addr[sizeof("255.255.255.255")];
1000
1001         ip4_string(ip4_addr, addr, fmt);
1002
1003         return string(buf, end, ip4_addr, spec);
1004 }
1005
1006 static noinline_for_stack
1007 char *ip6_addr_string_sa(char *buf, char *end, const struct sockaddr_in6 *sa,
1008                          struct printf_spec spec, const char *fmt)
1009 {
1010         bool have_p = false, have_s = false, have_f = false, have_c = false;
1011         char ip6_addr[sizeof("[xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255]") +
1012                       sizeof(":12345") + sizeof("/123456789") +
1013                       sizeof("%1234567890")];
1014         char *p = ip6_addr, *pend = ip6_addr + sizeof(ip6_addr);
1015         const u8 *addr = (const u8 *) &sa->sin6_addr;
1016         char fmt6[2] = { fmt[0], '6' };
1017         u8 off = 0;
1018
1019         fmt++;
1020         while (isalpha(*++fmt)) {
1021                 switch (*fmt) {
1022                 case 'p':
1023                         have_p = true;
1024                         break;
1025                 case 'f':
1026                         have_f = true;
1027                         break;
1028                 case 's':
1029                         have_s = true;
1030                         break;
1031                 case 'c':
1032                         have_c = true;
1033                         break;
1034                 }
1035         }
1036
1037         if (have_p || have_s || have_f) {
1038                 *p = '[';
1039                 off = 1;
1040         }
1041
1042         if (fmt6[0] == 'I' && have_c)
1043                 p = ip6_compressed_string(ip6_addr + off, addr);
1044         else
1045                 p = ip6_string(ip6_addr + off, addr, fmt6);
1046
1047         if (have_p || have_s || have_f)
1048                 *p++ = ']';
1049
1050         if (have_p) {
1051                 *p++ = ':';
1052                 p = number(p, pend, ntohs(sa->sin6_port), spec);
1053         }
1054         if (have_f) {
1055                 *p++ = '/';
1056                 p = number(p, pend, ntohl(sa->sin6_flowinfo &
1057                                           IPV6_FLOWINFO_MASK), spec);
1058         }
1059         if (have_s) {
1060                 *p++ = '%';
1061                 p = number(p, pend, sa->sin6_scope_id, spec);
1062         }
1063         *p = '\0';
1064
1065         return string(buf, end, ip6_addr, spec);
1066 }
1067
1068 static noinline_for_stack
1069 char *ip4_addr_string_sa(char *buf, char *end, const struct sockaddr_in *sa,
1070                          struct printf_spec spec, const char *fmt)
1071 {
1072         bool have_p = false;
1073         char *p, ip4_addr[sizeof("255.255.255.255") + sizeof(":12345")];
1074         char *pend = ip4_addr + sizeof(ip4_addr);
1075         const u8 *addr = (const u8 *) &sa->sin_addr.s_addr;
1076         char fmt4[3] = { fmt[0], '4', 0 };
1077
1078         fmt++;
1079         while (isalpha(*++fmt)) {
1080                 switch (*fmt) {
1081                 case 'p':
1082                         have_p = true;
1083                         break;
1084                 case 'h':
1085                 case 'l':
1086                 case 'n':
1087                 case 'b':
1088                         fmt4[2] = *fmt;
1089                         break;
1090                 }
1091         }
1092
1093         p = ip4_string(ip4_addr, addr, fmt4);
1094         if (have_p) {
1095                 *p++ = ':';
1096                 p = number(p, pend, ntohs(sa->sin_port), spec);
1097         }
1098         *p = '\0';
1099
1100         return string(buf, end, ip4_addr, spec);
1101 }
1102
1103 static noinline_for_stack
1104 char *uuid_string(char *buf, char *end, const u8 *addr,
1105                   struct printf_spec spec, const char *fmt)
1106 {
1107         char uuid[sizeof("xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx")];
1108         char *p = uuid;
1109         int i;
1110         static const u8 be[16] = {0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15};
1111         static const u8 le[16] = {3,2,1,0,5,4,7,6,8,9,10,11,12,13,14,15};
1112         const u8 *index = be;
1113         bool uc = false;
1114
1115         switch (*(++fmt)) {
1116         case 'L':
1117                 uc = true;              /* fall-through */
1118         case 'l':
1119                 index = le;
1120                 break;
1121         case 'B':
1122                 uc = true;
1123                 break;
1124         }
1125
1126         for (i = 0; i < 16; i++) {
1127                 p = hex_byte_pack(p, addr[index[i]]);
1128                 switch (i) {
1129                 case 3:
1130                 case 5:
1131                 case 7:
1132                 case 9:
1133                         *p++ = '-';
1134                         break;
1135                 }
1136         }
1137
1138         *p = 0;
1139
1140         if (uc) {
1141                 p = uuid;
1142                 do {
1143                         *p = toupper(*p);
1144                 } while (*(++p));
1145         }
1146
1147         return string(buf, end, uuid, spec);
1148 }
1149
1150 static
1151 char *netdev_feature_string(char *buf, char *end, const u8 *addr,
1152                       struct printf_spec spec)
1153 {
1154         spec.flags |= SPECIAL | SMALL | ZEROPAD;
1155         if (spec.field_width == -1)
1156                 spec.field_width = 2 + 2 * sizeof(netdev_features_t);
1157         spec.base = 16;
1158
1159         return number(buf, end, *(const netdev_features_t *)addr, spec);
1160 }
1161
1162 static noinline_for_stack
1163 char *address_val(char *buf, char *end, const void *addr,
1164                   struct printf_spec spec, const char *fmt)
1165 {
1166         unsigned long long num;
1167
1168         spec.flags |= SPECIAL | SMALL | ZEROPAD;
1169         spec.base = 16;
1170
1171         switch (fmt[1]) {
1172         case 'd':
1173                 num = *(const dma_addr_t *)addr;
1174                 spec.field_width = sizeof(dma_addr_t) * 2 + 2;
1175                 break;
1176         case 'p':
1177         default:
1178                 num = *(const phys_addr_t *)addr;
1179                 spec.field_width = sizeof(phys_addr_t) * 2 + 2;
1180                 break;
1181         }
1182
1183         return number(buf, end, num, spec);
1184 }
1185
1186 int kptr_restrict __read_mostly;
1187
1188 /*
1189  * Show a '%p' thing.  A kernel extension is that the '%p' is followed
1190  * by an extra set of alphanumeric characters that are extended format
1191  * specifiers.
1192  *
1193  * Right now we handle:
1194  *
1195  * - 'F' For symbolic function descriptor pointers with offset
1196  * - 'f' For simple symbolic function names without offset
1197  * - 'S' For symbolic direct pointers with offset
1198  * - 's' For symbolic direct pointers without offset
1199  * - '[FfSs]R' as above with __builtin_extract_return_addr() translation
1200  * - 'B' For backtraced symbolic direct pointers with offset
1201  * - 'R' For decoded struct resource, e.g., [mem 0x0-0x1f 64bit pref]
1202  * - 'r' For raw struct resource, e.g., [mem 0x0-0x1f flags 0x201]
1203  * - 'M' For a 6-byte MAC address, it prints the address in the
1204  *       usual colon-separated hex notation
1205  * - 'm' For a 6-byte MAC address, it prints the hex address without colons
1206  * - 'MF' For a 6-byte MAC FDDI address, it prints the address
1207  *       with a dash-separated hex notation
1208  * - '[mM]R' For a 6-byte MAC address, Reverse order (Bluetooth)
1209  * - 'I' [46] for IPv4/IPv6 addresses printed in the usual way
1210  *       IPv4 uses dot-separated decimal without leading 0's (1.2.3.4)
1211  *       IPv6 uses colon separated network-order 16 bit hex with leading 0's
1212  *       [S][pfs]
1213  *       Generic IPv4/IPv6 address (struct sockaddr *) that falls back to
1214  *       [4] or [6] and is able to print port [p], flowinfo [f], scope [s]
1215  * - 'i' [46] for 'raw' IPv4/IPv6 addresses
1216  *       IPv6 omits the colons (01020304...0f)
1217  *       IPv4 uses dot-separated decimal with leading 0's (010.123.045.006)
1218  *       [S][pfs]
1219  *       Generic IPv4/IPv6 address (struct sockaddr *) that falls back to
1220  *       [4] or [6] and is able to print port [p], flowinfo [f], scope [s]
1221  * - '[Ii][4S][hnbl]' IPv4 addresses in host, network, big or little endian order
1222  * - 'I[6S]c' for IPv6 addresses printed as specified by
1223  *       http://tools.ietf.org/html/rfc5952
1224  * - 'U' For a 16 byte UUID/GUID, it prints the UUID/GUID in the form
1225  *       "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx"
1226  *       Options for %pU are:
1227  *         b big endian lower case hex (default)
1228  *         B big endian UPPER case hex
1229  *         l little endian lower case hex
1230  *         L little endian UPPER case hex
1231  *           big endian output byte order is:
1232  *             [0][1][2][3]-[4][5]-[6][7]-[8][9]-[10][11][12][13][14][15]
1233  *           little endian output byte order is:
1234  *             [3][2][1][0]-[5][4]-[7][6]-[8][9]-[10][11][12][13][14][15]
1235  * - 'V' For a struct va_format which contains a format string * and va_list *,
1236  *       call vsnprintf(->format, *->va_list).
1237  *       Implements a "recursive vsnprintf".
1238  *       Do not use this feature without some mechanism to verify the
1239  *       correctness of the format string and va_list arguments.
1240  * - 'K' For a kernel pointer that should be hidden from unprivileged users
1241  * - 'NF' For a netdev_features_t
1242  * - 'h[CDN]' For a variable-length buffer, it prints it as a hex string with
1243  *            a certain separator (' ' by default):
1244  *              C colon
1245  *              D dash
1246  *              N no separator
1247  *            The maximum supported length is 64 bytes of the input. Consider
1248  *            to use print_hex_dump() for the larger input.
1249  * - 'a[pd]' For address types [p] phys_addr_t, [d] dma_addr_t and derivatives
1250  *           (default assumed to be phys_addr_t, passed by reference)
1251  * - 'd[234]' For a dentry name (optionally 2-4 last components)
1252  * - 'D[234]' Same as 'd' but for a struct file
1253  *
1254  * Note: The difference between 'S' and 'F' is that on ia64 and ppc64
1255  * function pointers are really function descriptors, which contain a
1256  * pointer to the real address.
1257  */
1258 static noinline_for_stack
1259 char *pointer(const char *fmt, char *buf, char *end, void *ptr,
1260               struct printf_spec spec)
1261 {
1262         int default_width = 2 * sizeof(void *) + (spec.flags & SPECIAL ? 2 : 0);
1263
1264         if (!ptr && *fmt != 'K') {
1265                 /*
1266                  * Print (null) with the same width as a pointer so it makes
1267                  * tabular output look nice.
1268                  */
1269                 if (spec.field_width == -1)
1270                         spec.field_width = default_width;
1271                 return string(buf, end, "(null)", spec);
1272         }
1273
1274         switch (*fmt) {
1275         case 'F':
1276         case 'f':
1277                 ptr = dereference_function_descriptor(ptr);
1278                 /* Fallthrough */
1279         case 'S':
1280         case 's':
1281         case 'B':
1282                 return symbol_string(buf, end, ptr, spec, fmt);
1283         case 'R':
1284         case 'r':
1285                 return resource_string(buf, end, ptr, spec, fmt);
1286         case 'h':
1287                 return hex_string(buf, end, ptr, spec, fmt);
1288         case 'M':                       /* Colon separated: 00:01:02:03:04:05 */
1289         case 'm':                       /* Contiguous: 000102030405 */
1290                                         /* [mM]F (FDDI) */
1291                                         /* [mM]R (Reverse order; Bluetooth) */
1292                 return mac_address_string(buf, end, ptr, spec, fmt);
1293         case 'I':                       /* Formatted IP supported
1294                                          * 4:   1.2.3.4
1295                                          * 6:   0001:0203:...:0708
1296                                          * 6c:  1::708 or 1::1.2.3.4
1297                                          */
1298         case 'i':                       /* Contiguous:
1299                                          * 4:   001.002.003.004
1300                                          * 6:   000102...0f
1301                                          */
1302                 switch (fmt[1]) {
1303                 case '6':
1304                         return ip6_addr_string(buf, end, ptr, spec, fmt);
1305                 case '4':
1306                         return ip4_addr_string(buf, end, ptr, spec, fmt);
1307                 case 'S': {
1308                         const union {
1309                                 struct sockaddr         raw;
1310                                 struct sockaddr_in      v4;
1311                                 struct sockaddr_in6     v6;
1312                         } *sa = ptr;
1313
1314                         switch (sa->raw.sa_family) {
1315                         case AF_INET:
1316                                 return ip4_addr_string_sa(buf, end, &sa->v4, spec, fmt);
1317                         case AF_INET6:
1318                                 return ip6_addr_string_sa(buf, end, &sa->v6, spec, fmt);
1319                         default:
1320                                 return string(buf, end, "(invalid address)", spec);
1321                         }}
1322                 }
1323                 break;
1324         case 'U':
1325                 return uuid_string(buf, end, ptr, spec, fmt);
1326         case 'V':
1327                 {
1328                         va_list va;
1329
1330                         va_copy(va, *((struct va_format *)ptr)->va);
1331                         buf += vsnprintf(buf, end > buf ? end - buf : 0,
1332                                          ((struct va_format *)ptr)->fmt, va);
1333                         va_end(va);
1334                         return buf;
1335                 }
1336         case 'K':
1337                 /*
1338                  * %pK cannot be used in IRQ context because its test
1339                  * for CAP_SYSLOG would be meaningless.
1340                  */
1341                 if (kptr_restrict && (in_irq() || in_serving_softirq() ||
1342                                       in_nmi())) {
1343                         if (spec.field_width == -1)
1344                                 spec.field_width = default_width;
1345                         return string(buf, end, "pK-error", spec);
1346                 }
1347
1348                 switch (kptr_restrict) {
1349                 case 0:
1350                         /* Always print %pK values */
1351                         break;
1352                 case 1: {
1353                         /*
1354                          * Only print the real pointer value if the current
1355                          * process has CAP_SYSLOG and is running with the
1356                          * same credentials it started with. This is because
1357                          * access to files is checked at open() time, but %pK
1358                          * checks permission at read() time. We don't want to
1359                          * leak pointer values if a binary opens a file using
1360                          * %pK and then elevates privileges before reading it.
1361                          */
1362                         const struct cred *cred = current_cred();
1363
1364                         if (!has_capability_noaudit(current, CAP_SYSLOG) ||
1365                             !uid_eq(cred->euid, cred->uid) ||
1366                             !gid_eq(cred->egid, cred->gid))
1367                                 ptr = NULL;
1368                         break;
1369                 }
1370                 case 2:
1371                 default:
1372                         /* Always print 0's for %pK */
1373                         ptr = NULL;
1374                         break;
1375                 }
1376                 break;
1377
1378         case 'N':
1379                 switch (fmt[1]) {
1380                 case 'F':
1381                         return netdev_feature_string(buf, end, ptr, spec);
1382                 }
1383                 break;
1384         case 'a':
1385                 return address_val(buf, end, ptr, spec, fmt);
1386         case 'd':
1387                 return dentry_name(buf, end, ptr, spec, fmt);
1388         case 'D':
1389                 return dentry_name(buf, end,
1390                                    ((const struct file *)ptr)->f_path.dentry,
1391                                    spec, fmt);
1392         }
1393         spec.flags |= SMALL;
1394         if (spec.field_width == -1) {
1395                 spec.field_width = default_width;
1396                 spec.flags |= ZEROPAD;
1397         }
1398         spec.base = 16;
1399
1400         return number(buf, end, (unsigned long) ptr, spec);
1401 }
1402
1403 /*
1404  * Helper function to decode printf style format.
1405  * Each call decode a token from the format and return the
1406  * number of characters read (or likely the delta where it wants
1407  * to go on the next call).
1408  * The decoded token is returned through the parameters
1409  *
1410  * 'h', 'l', or 'L' for integer fields
1411  * 'z' support added 23/7/1999 S.H.
1412  * 'z' changed to 'Z' --davidm 1/25/99
1413  * 't' added for ptrdiff_t
1414  *
1415  * @fmt: the format string
1416  * @type of the token returned
1417  * @flags: various flags such as +, -, # tokens..
1418  * @field_width: overwritten width
1419  * @base: base of the number (octal, hex, ...)
1420  * @precision: precision of a number
1421  * @qualifier: qualifier of a number (long, size_t, ...)
1422  */
1423 static noinline_for_stack
1424 int format_decode(const char *fmt, struct printf_spec *spec)
1425 {
1426         const char *start = fmt;
1427
1428         /* we finished early by reading the field width */
1429         if (spec->type == FORMAT_TYPE_WIDTH) {
1430                 if (spec->field_width < 0) {
1431                         spec->field_width = -spec->field_width;
1432                         spec->flags |= LEFT;
1433                 }
1434                 spec->type = FORMAT_TYPE_NONE;
1435                 goto precision;
1436         }
1437
1438         /* we finished early by reading the precision */
1439         if (spec->type == FORMAT_TYPE_PRECISION) {
1440                 if (spec->precision < 0)
1441                         spec->precision = 0;
1442
1443                 spec->type = FORMAT_TYPE_NONE;
1444                 goto qualifier;
1445         }
1446
1447         /* By default */
1448         spec->type = FORMAT_TYPE_NONE;
1449
1450         for (; *fmt ; ++fmt) {
1451                 if (*fmt == '%')
1452                         break;
1453         }
1454
1455         /* Return the current non-format string */
1456         if (fmt != start || !*fmt)
1457                 return fmt - start;
1458
1459         /* Process flags */
1460         spec->flags = 0;
1461
1462         while (1) { /* this also skips first '%' */
1463                 bool found = true;
1464
1465                 ++fmt;
1466
1467                 switch (*fmt) {
1468                 case '-': spec->flags |= LEFT;    break;
1469                 case '+': spec->flags |= PLUS;    break;
1470                 case ' ': spec->flags |= SPACE;   break;
1471                 case '#': spec->flags |= SPECIAL; break;
1472                 case '0': spec->flags |= ZEROPAD; break;
1473                 default:  found = false;
1474                 }
1475
1476                 if (!found)
1477                         break;
1478         }
1479
1480         /* get field width */
1481         spec->field_width = -1;
1482
1483         if (isdigit(*fmt))
1484                 spec->field_width = skip_atoi(&fmt);
1485         else if (*fmt == '*') {
1486                 /* it's the next argument */
1487                 spec->type = FORMAT_TYPE_WIDTH;
1488                 return ++fmt - start;
1489         }
1490
1491 precision:
1492         /* get the precision */
1493         spec->precision = -1;
1494         if (*fmt == '.') {
1495                 ++fmt;
1496                 if (isdigit(*fmt)) {
1497                         spec->precision = skip_atoi(&fmt);
1498                         if (spec->precision < 0)
1499                                 spec->precision = 0;
1500                 } else if (*fmt == '*') {
1501                         /* it's the next argument */
1502                         spec->type = FORMAT_TYPE_PRECISION;
1503                         return ++fmt - start;
1504                 }
1505         }
1506
1507 qualifier:
1508         /* get the conversion qualifier */
1509         spec->qualifier = -1;
1510         if (*fmt == 'h' || _tolower(*fmt) == 'l' ||
1511             _tolower(*fmt) == 'z' || *fmt == 't') {
1512                 spec->qualifier = *fmt++;
1513                 if (unlikely(spec->qualifier == *fmt)) {
1514                         if (spec->qualifier == 'l') {
1515                                 spec->qualifier = 'L';
1516                                 ++fmt;
1517                         } else if (spec->qualifier == 'h') {
1518                                 spec->qualifier = 'H';
1519                                 ++fmt;
1520                         }
1521                 }
1522         }
1523
1524         /* default base */
1525         spec->base = 10;
1526         switch (*fmt) {
1527         case 'c':
1528                 spec->type = FORMAT_TYPE_CHAR;
1529                 return ++fmt - start;
1530
1531         case 's':
1532                 spec->type = FORMAT_TYPE_STR;
1533                 return ++fmt - start;
1534
1535         case 'p':
1536                 spec->type = FORMAT_TYPE_PTR;
1537                 return fmt - start;
1538                 /* skip alnum */
1539
1540         case '%':
1541                 spec->type = FORMAT_TYPE_PERCENT_CHAR;
1542                 return ++fmt - start;
1543
1544         /* integer number formats - set up the flags and "break" */
1545         case 'o':
1546                 spec->base = 8;
1547                 break;
1548
1549         case 'x':
1550                 spec->flags |= SMALL;
1551
1552         case 'X':
1553                 spec->base = 16;
1554                 break;
1555
1556         case 'd':
1557         case 'i':
1558                 spec->flags |= SIGN;
1559         case 'u':
1560                 break;
1561
1562         case 'n':
1563                 /*
1564                  * Since %n poses a greater security risk than utility, treat
1565                  * it as an invalid format specifier. Warn about its use so
1566                  * that new instances don't get added.
1567                  */
1568                 WARN_ONCE(1, "Please remove ignored %%n in '%s'\n", fmt);
1569                 /* Fall-through */
1570
1571         default:
1572                 spec->type = FORMAT_TYPE_INVALID;
1573                 return fmt - start;
1574         }
1575
1576         if (spec->qualifier == 'L')
1577                 spec->type = FORMAT_TYPE_LONG_LONG;
1578         else if (spec->qualifier == 'l') {
1579                 if (spec->flags & SIGN)
1580                         spec->type = FORMAT_TYPE_LONG;
1581                 else
1582                         spec->type = FORMAT_TYPE_ULONG;
1583         } else if (_tolower(spec->qualifier) == 'z') {
1584                 spec->type = FORMAT_TYPE_SIZE_T;
1585         } else if (spec->qualifier == 't') {
1586                 spec->type = FORMAT_TYPE_PTRDIFF;
1587         } else if (spec->qualifier == 'H') {
1588                 if (spec->flags & SIGN)
1589                         spec->type = FORMAT_TYPE_BYTE;
1590                 else
1591                         spec->type = FORMAT_TYPE_UBYTE;
1592         } else if (spec->qualifier == 'h') {
1593                 if (spec->flags & SIGN)
1594                         spec->type = FORMAT_TYPE_SHORT;
1595                 else
1596                         spec->type = FORMAT_TYPE_USHORT;
1597         } else {
1598                 if (spec->flags & SIGN)
1599                         spec->type = FORMAT_TYPE_INT;
1600                 else
1601                         spec->type = FORMAT_TYPE_UINT;
1602         }
1603
1604         return ++fmt - start;
1605 }
1606
1607 /**
1608  * vsnprintf - Format a string and place it in a buffer
1609  * @buf: The buffer to place the result into
1610  * @size: The size of the buffer, including the trailing null space
1611  * @fmt: The format string to use
1612  * @args: Arguments for the format string
1613  *
1614  * This function follows C99 vsnprintf, but has some extensions:
1615  * %pS output the name of a text symbol with offset
1616  * %ps output the name of a text symbol without offset
1617  * %pF output the name of a function pointer with its offset
1618  * %pf output the name of a function pointer without its offset
1619  * %pB output the name of a backtrace symbol with its offset
1620  * %pR output the address range in a struct resource with decoded flags
1621  * %pr output the address range in a struct resource with raw flags
1622  * %pM output a 6-byte MAC address with colons
1623  * %pMR output a 6-byte MAC address with colons in reversed order
1624  * %pMF output a 6-byte MAC address with dashes
1625  * %pm output a 6-byte MAC address without colons
1626  * %pmR output a 6-byte MAC address without colons in reversed order
1627  * %pI4 print an IPv4 address without leading zeros
1628  * %pi4 print an IPv4 address with leading zeros
1629  * %pI6 print an IPv6 address with colons
1630  * %pi6 print an IPv6 address without colons
1631  * %pI6c print an IPv6 address as specified by RFC 5952
1632  * %pIS depending on sa_family of 'struct sockaddr *' print IPv4/IPv6 address
1633  * %piS depending on sa_family of 'struct sockaddr *' print IPv4/IPv6 address
1634  * %pU[bBlL] print a UUID/GUID in big or little endian using lower or upper
1635  *   case.
1636  * %*ph[CDN] a variable-length hex string with a separator (supports up to 64
1637  *           bytes of the input)
1638  * %n is ignored
1639  *
1640  * ** Please update Documentation/printk-formats.txt when making changes **
1641  *
1642  * The return value is the number of characters which would
1643  * be generated for the given input, excluding the trailing
1644  * '\0', as per ISO C99. If you want to have the exact
1645  * number of characters written into @buf as return value
1646  * (not including the trailing '\0'), use vscnprintf(). If the
1647  * return is greater than or equal to @size, the resulting
1648  * string is truncated.
1649  *
1650  * If you're not already dealing with a va_list consider using snprintf().
1651  */
1652 int vsnprintf(char *buf, size_t size, const char *fmt, va_list args)
1653 {
1654         unsigned long long num;
1655         char *str, *end;
1656         struct printf_spec spec = {0};
1657
1658         /* Reject out-of-range values early.  Large positive sizes are
1659            used for unknown buffer sizes. */
1660         if (WARN_ON_ONCE((int) size < 0))
1661                 return 0;
1662
1663         str = buf;
1664         end = buf + size;
1665
1666         /* Make sure end is always >= buf */
1667         if (end < buf) {
1668                 end = ((void *)-1);
1669                 size = end - buf;
1670         }
1671
1672         while (*fmt) {
1673                 const char *old_fmt = fmt;
1674                 int read = format_decode(fmt, &spec);
1675
1676                 fmt += read;
1677
1678                 switch (spec.type) {
1679                 case FORMAT_TYPE_NONE: {
1680                         int copy = read;
1681                         if (str < end) {
1682                                 if (copy > end - str)
1683                                         copy = end - str;
1684                                 memcpy(str, old_fmt, copy);
1685                         }
1686                         str += read;
1687                         break;
1688                 }
1689
1690                 case FORMAT_TYPE_WIDTH:
1691                         spec.field_width = va_arg(args, int);
1692                         break;
1693
1694                 case FORMAT_TYPE_PRECISION:
1695                         spec.precision = va_arg(args, int);
1696                         break;
1697
1698                 case FORMAT_TYPE_CHAR: {
1699                         char c;
1700
1701                         if (!(spec.flags & LEFT)) {
1702                                 while (--spec.field_width > 0) {
1703                                         if (str < end)
1704                                                 *str = ' ';
1705                                         ++str;
1706
1707                                 }
1708                         }
1709                         c = (unsigned char) va_arg(args, int);
1710                         if (str < end)
1711                                 *str = c;
1712                         ++str;
1713                         while (--spec.field_width > 0) {
1714                                 if (str < end)
1715                                         *str = ' ';
1716                                 ++str;
1717                         }
1718                         break;
1719                 }
1720
1721                 case FORMAT_TYPE_STR:
1722                         str = string(str, end, va_arg(args, char *), spec);
1723                         break;
1724
1725                 case FORMAT_TYPE_PTR:
1726                         str = pointer(fmt+1, str, end, va_arg(args, void *),
1727                                       spec);
1728                         while (isalnum(*fmt))
1729                                 fmt++;
1730                         break;
1731
1732                 case FORMAT_TYPE_PERCENT_CHAR:
1733                         if (str < end)
1734                                 *str = '%';
1735                         ++str;
1736                         break;
1737
1738                 case FORMAT_TYPE_INVALID:
1739                         if (str < end)
1740                                 *str = '%';
1741                         ++str;
1742                         break;
1743
1744                 default:
1745                         switch (spec.type) {
1746                         case FORMAT_TYPE_LONG_LONG:
1747                                 num = va_arg(args, long long);
1748                                 break;
1749                         case FORMAT_TYPE_ULONG:
1750                                 num = va_arg(args, unsigned long);
1751                                 break;
1752                         case FORMAT_TYPE_LONG:
1753                                 num = va_arg(args, long);
1754                                 break;
1755                         case FORMAT_TYPE_SIZE_T:
1756                                 if (spec.flags & SIGN)
1757                                         num = va_arg(args, ssize_t);
1758                                 else
1759                                         num = va_arg(args, size_t);
1760                                 break;
1761                         case FORMAT_TYPE_PTRDIFF:
1762                                 num = va_arg(args, ptrdiff_t);
1763                                 break;
1764                         case FORMAT_TYPE_UBYTE:
1765                                 num = (unsigned char) va_arg(args, int);
1766                                 break;
1767                         case FORMAT_TYPE_BYTE:
1768                                 num = (signed char) va_arg(args, int);
1769                                 break;
1770                         case FORMAT_TYPE_USHORT:
1771                                 num = (unsigned short) va_arg(args, int);
1772                                 break;
1773                         case FORMAT_TYPE_SHORT:
1774                                 num = (short) va_arg(args, int);
1775                                 break;
1776                         case FORMAT_TYPE_INT:
1777                                 num = (int) va_arg(args, int);
1778                                 break;
1779                         default:
1780                                 num = va_arg(args, unsigned int);
1781                         }
1782
1783                         str = number(str, end, num, spec);
1784                 }
1785         }
1786
1787         if (size > 0) {
1788                 if (str < end)
1789                         *str = '\0';
1790                 else
1791                         end[-1] = '\0';
1792         }
1793
1794         /* the trailing null byte doesn't count towards the total */
1795         return str-buf;
1796
1797 }
1798 EXPORT_SYMBOL(vsnprintf);
1799
1800 /**
1801  * vscnprintf - Format a string and place it in a buffer
1802  * @buf: The buffer to place the result into
1803  * @size: The size of the buffer, including the trailing null space
1804  * @fmt: The format string to use
1805  * @args: Arguments for the format string
1806  *
1807  * The return value is the number of characters which have been written into
1808  * the @buf not including the trailing '\0'. If @size is == 0 the function
1809  * returns 0.
1810  *
1811  * If you're not already dealing with a va_list consider using scnprintf().
1812  *
1813  * See the vsnprintf() documentation for format string extensions over C99.
1814  */
1815 int vscnprintf(char *buf, size_t size, const char *fmt, va_list args)
1816 {
1817         int i;
1818
1819         i = vsnprintf(buf, size, fmt, args);
1820
1821         if (likely(i < size))
1822                 return i;
1823         if (size != 0)
1824                 return size - 1;
1825         return 0;
1826 }
1827 EXPORT_SYMBOL(vscnprintf);
1828
1829 /**
1830  * snprintf - Format a string and place it in a buffer
1831  * @buf: The buffer to place the result into
1832  * @size: The size of the buffer, including the trailing null space
1833  * @fmt: The format string to use
1834  * @...: Arguments for the format string
1835  *
1836  * The return value is the number of characters which would be
1837  * generated for the given input, excluding the trailing null,
1838  * as per ISO C99.  If the return is greater than or equal to
1839  * @size, the resulting string is truncated.
1840  *
1841  * See the vsnprintf() documentation for format string extensions over C99.
1842  */
1843 int snprintf(char *buf, size_t size, const char *fmt, ...)
1844 {
1845         va_list args;
1846         int i;
1847
1848         va_start(args, fmt);
1849         i = vsnprintf(buf, size, fmt, args);
1850         va_end(args);
1851
1852         return i;
1853 }
1854 EXPORT_SYMBOL(snprintf);
1855
1856 /**
1857  * scnprintf - Format a string and place it in a buffer
1858  * @buf: The buffer to place the result into
1859  * @size: The size of the buffer, including the trailing null space
1860  * @fmt: The format string to use
1861  * @...: Arguments for the format string
1862  *
1863  * The return value is the number of characters written into @buf not including
1864  * the trailing '\0'. If @size is == 0 the function returns 0.
1865  */
1866
1867 int scnprintf(char *buf, size_t size, const char *fmt, ...)
1868 {
1869         va_list args;
1870         int i;
1871
1872         va_start(args, fmt);
1873         i = vscnprintf(buf, size, fmt, args);
1874         va_end(args);
1875
1876         return i;
1877 }
1878 EXPORT_SYMBOL(scnprintf);
1879
1880 /**
1881  * vsprintf - Format a string and place it in a buffer
1882  * @buf: The buffer to place the result into
1883  * @fmt: The format string to use
1884  * @args: Arguments for the format string
1885  *
1886  * The function returns the number of characters written
1887  * into @buf. Use vsnprintf() or vscnprintf() in order to avoid
1888  * buffer overflows.
1889  *
1890  * If you're not already dealing with a va_list consider using sprintf().
1891  *
1892  * See the vsnprintf() documentation for format string extensions over C99.
1893  */
1894 int vsprintf(char *buf, const char *fmt, va_list args)
1895 {
1896         return vsnprintf(buf, INT_MAX, fmt, args);
1897 }
1898 EXPORT_SYMBOL(vsprintf);
1899
1900 /**
1901  * sprintf - Format a string and place it in a buffer
1902  * @buf: The buffer to place the result into
1903  * @fmt: The format string to use
1904  * @...: Arguments for the format string
1905  *
1906  * The function returns the number of characters written
1907  * into @buf. Use snprintf() or scnprintf() in order to avoid
1908  * buffer overflows.
1909  *
1910  * See the vsnprintf() documentation for format string extensions over C99.
1911  */
1912 int sprintf(char *buf, const char *fmt, ...)
1913 {
1914         va_list args;
1915         int i;
1916
1917         va_start(args, fmt);
1918         i = vsnprintf(buf, INT_MAX, fmt, args);
1919         va_end(args);
1920
1921         return i;
1922 }
1923 EXPORT_SYMBOL(sprintf);
1924
1925 #ifdef CONFIG_BINARY_PRINTF
1926 /*
1927  * bprintf service:
1928  * vbin_printf() - VA arguments to binary data
1929  * bstr_printf() - Binary data to text string
1930  */
1931
1932 /**
1933  * vbin_printf - Parse a format string and place args' binary value in a buffer
1934  * @bin_buf: The buffer to place args' binary value
1935  * @size: The size of the buffer(by words(32bits), not characters)
1936  * @fmt: The format string to use
1937  * @args: Arguments for the format string
1938  *
1939  * The format follows C99 vsnprintf, except %n is ignored, and its argument
1940  * is skiped.
1941  *
1942  * The return value is the number of words(32bits) which would be generated for
1943  * the given input.
1944  *
1945  * NOTE:
1946  * If the return value is greater than @size, the resulting bin_buf is NOT
1947  * valid for bstr_printf().
1948  */
1949 int vbin_printf(u32 *bin_buf, size_t size, const char *fmt, va_list args)
1950 {
1951         struct printf_spec spec = {0};
1952         char *str, *end;
1953
1954         str = (char *)bin_buf;
1955         end = (char *)(bin_buf + size);
1956
1957 #define save_arg(type)                                                  \
1958 do {                                                                    \
1959         if (sizeof(type) == 8) {                                        \
1960                 unsigned long long value;                               \
1961                 str = PTR_ALIGN(str, sizeof(u32));                      \
1962                 value = va_arg(args, unsigned long long);               \
1963                 if (str + sizeof(type) <= end) {                        \
1964                         *(u32 *)str = *(u32 *)&value;                   \
1965                         *(u32 *)(str + 4) = *((u32 *)&value + 1);       \
1966                 }                                                       \
1967         } else {                                                        \
1968                 unsigned long value;                                    \
1969                 str = PTR_ALIGN(str, sizeof(type));                     \
1970                 value = va_arg(args, int);                              \
1971                 if (str + sizeof(type) <= end)                          \
1972                         *(typeof(type) *)str = (type)value;             \
1973         }                                                               \
1974         str += sizeof(type);                                            \
1975 } while (0)
1976
1977         while (*fmt) {
1978                 int read = format_decode(fmt, &spec);
1979
1980                 fmt += read;
1981
1982                 switch (spec.type) {
1983                 case FORMAT_TYPE_NONE:
1984                 case FORMAT_TYPE_INVALID:
1985                 case FORMAT_TYPE_PERCENT_CHAR:
1986                         break;
1987
1988                 case FORMAT_TYPE_WIDTH:
1989                 case FORMAT_TYPE_PRECISION:
1990                         save_arg(int);
1991                         break;
1992
1993                 case FORMAT_TYPE_CHAR:
1994                         save_arg(char);
1995                         break;
1996
1997                 case FORMAT_TYPE_STR: {
1998                         const char *save_str = va_arg(args, char *);
1999                         size_t len;
2000
2001                         if ((unsigned long)save_str > (unsigned long)-PAGE_SIZE
2002                                         || (unsigned long)save_str < PAGE_SIZE)
2003                                 save_str = "(null)";
2004                         len = strlen(save_str) + 1;
2005                         if (str + len < end)
2006                                 memcpy(str, save_str, len);
2007                         str += len;
2008                         break;
2009                 }
2010
2011                 case FORMAT_TYPE_PTR:
2012                         save_arg(void *);
2013                         /* skip all alphanumeric pointer suffixes */
2014                         while (isalnum(*fmt))
2015                                 fmt++;
2016                         break;
2017
2018                 default:
2019                         switch (spec.type) {
2020
2021                         case FORMAT_TYPE_LONG_LONG:
2022                                 save_arg(long long);
2023                                 break;
2024                         case FORMAT_TYPE_ULONG:
2025                         case FORMAT_TYPE_LONG:
2026                                 save_arg(unsigned long);
2027                                 break;
2028                         case FORMAT_TYPE_SIZE_T:
2029                                 save_arg(size_t);
2030                                 break;
2031                         case FORMAT_TYPE_PTRDIFF:
2032                                 save_arg(ptrdiff_t);
2033                                 break;
2034                         case FORMAT_TYPE_UBYTE:
2035                         case FORMAT_TYPE_BYTE:
2036                                 save_arg(char);
2037                                 break;
2038                         case FORMAT_TYPE_USHORT:
2039                         case FORMAT_TYPE_SHORT:
2040                                 save_arg(short);
2041                                 break;
2042                         default:
2043                                 save_arg(int);
2044                         }
2045                 }
2046         }
2047
2048         return (u32 *)(PTR_ALIGN(str, sizeof(u32))) - bin_buf;
2049 #undef save_arg
2050 }
2051 EXPORT_SYMBOL_GPL(vbin_printf);
2052
2053 /**
2054  * bstr_printf - Format a string from binary arguments and place it in a buffer
2055  * @buf: The buffer to place the result into
2056  * @size: The size of the buffer, including the trailing null space
2057  * @fmt: The format string to use
2058  * @bin_buf: Binary arguments for the format string
2059  *
2060  * This function like C99 vsnprintf, but the difference is that vsnprintf gets
2061  * arguments from stack, and bstr_printf gets arguments from @bin_buf which is
2062  * a binary buffer that generated by vbin_printf.
2063  *
2064  * The format follows C99 vsnprintf, but has some extensions:
2065  *  see vsnprintf comment for details.
2066  *
2067  * The return value is the number of characters which would
2068  * be generated for the given input, excluding the trailing
2069  * '\0', as per ISO C99. If you want to have the exact
2070  * number of characters written into @buf as return value
2071  * (not including the trailing '\0'), use vscnprintf(). If the
2072  * return is greater than or equal to @size, the resulting
2073  * string is truncated.
2074  */
2075 int bstr_printf(char *buf, size_t size, const char *fmt, const u32 *bin_buf)
2076 {
2077         struct printf_spec spec = {0};
2078         char *str, *end;
2079         const char *args = (const char *)bin_buf;
2080
2081         if (WARN_ON_ONCE((int) size < 0))
2082                 return 0;
2083
2084         str = buf;
2085         end = buf + size;
2086
2087 #define get_arg(type)                                                   \
2088 ({                                                                      \
2089         typeof(type) value;                                             \
2090         if (sizeof(type) == 8) {                                        \
2091                 args = PTR_ALIGN(args, sizeof(u32));                    \
2092                 *(u32 *)&value = *(u32 *)args;                          \
2093                 *((u32 *)&value + 1) = *(u32 *)(args + 4);              \
2094         } else {                                                        \
2095                 args = PTR_ALIGN(args, sizeof(type));                   \
2096                 value = *(typeof(type) *)args;                          \
2097         }                                                               \
2098         args += sizeof(type);                                           \
2099         value;                                                          \
2100 })
2101
2102         /* Make sure end is always >= buf */
2103         if (end < buf) {
2104                 end = ((void *)-1);
2105                 size = end - buf;
2106         }
2107
2108         while (*fmt) {
2109                 const char *old_fmt = fmt;
2110                 int read = format_decode(fmt, &spec);
2111
2112                 fmt += read;
2113
2114                 switch (spec.type) {
2115                 case FORMAT_TYPE_NONE: {
2116                         int copy = read;
2117                         if (str < end) {
2118                                 if (copy > end - str)
2119                                         copy = end - str;
2120                                 memcpy(str, old_fmt, copy);
2121                         }
2122                         str += read;
2123                         break;
2124                 }
2125
2126                 case FORMAT_TYPE_WIDTH:
2127                         spec.field_width = get_arg(int);
2128                         break;
2129
2130                 case FORMAT_TYPE_PRECISION:
2131                         spec.precision = get_arg(int);
2132                         break;
2133
2134                 case FORMAT_TYPE_CHAR: {
2135                         char c;
2136
2137                         if (!(spec.flags & LEFT)) {
2138                                 while (--spec.field_width > 0) {
2139                                         if (str < end)
2140                                                 *str = ' ';
2141                                         ++str;
2142                                 }
2143                         }
2144                         c = (unsigned char) get_arg(char);
2145                         if (str < end)
2146                                 *str = c;
2147                         ++str;
2148                         while (--spec.field_width > 0) {
2149                                 if (str < end)
2150                                         *str = ' ';
2151                                 ++str;
2152                         }
2153                         break;
2154                 }
2155
2156                 case FORMAT_TYPE_STR: {
2157                         const char *str_arg = args;
2158                         args += strlen(str_arg) + 1;
2159                         str = string(str, end, (char *)str_arg, spec);
2160                         break;
2161                 }
2162
2163                 case FORMAT_TYPE_PTR:
2164                         str = pointer(fmt+1, str, end, get_arg(void *), spec);
2165                         while (isalnum(*fmt))
2166                                 fmt++;
2167                         break;
2168
2169                 case FORMAT_TYPE_PERCENT_CHAR:
2170                 case FORMAT_TYPE_INVALID:
2171                         if (str < end)
2172                                 *str = '%';
2173                         ++str;
2174                         break;
2175
2176                 default: {
2177                         unsigned long long num;
2178
2179                         switch (spec.type) {
2180
2181                         case FORMAT_TYPE_LONG_LONG:
2182                                 num = get_arg(long long);
2183                                 break;
2184                         case FORMAT_TYPE_ULONG:
2185                         case FORMAT_TYPE_LONG:
2186                                 num = get_arg(unsigned long);
2187                                 break;
2188                         case FORMAT_TYPE_SIZE_T:
2189                                 num = get_arg(size_t);
2190                                 break;
2191                         case FORMAT_TYPE_PTRDIFF:
2192                                 num = get_arg(ptrdiff_t);
2193                                 break;
2194                         case FORMAT_TYPE_UBYTE:
2195                                 num = get_arg(unsigned char);
2196                                 break;
2197                         case FORMAT_TYPE_BYTE:
2198                                 num = get_arg(signed char);
2199                                 break;
2200                         case FORMAT_TYPE_USHORT:
2201                                 num = get_arg(unsigned short);
2202                                 break;
2203                         case FORMAT_TYPE_SHORT:
2204                                 num = get_arg(short);
2205                                 break;
2206                         case FORMAT_TYPE_UINT:
2207                                 num = get_arg(unsigned int);
2208                                 break;
2209                         default:
2210                                 num = get_arg(int);
2211                         }
2212
2213                         str = number(str, end, num, spec);
2214                 } /* default: */
2215                 } /* switch(spec.type) */
2216         } /* while(*fmt) */
2217
2218         if (size > 0) {
2219                 if (str < end)
2220                         *str = '\0';
2221                 else
2222                         end[-1] = '\0';
2223         }
2224
2225 #undef get_arg
2226
2227         /* the trailing null byte doesn't count towards the total */
2228         return str - buf;
2229 }
2230 EXPORT_SYMBOL_GPL(bstr_printf);
2231
2232 /**
2233  * bprintf - Parse a format string and place args' binary value in a buffer
2234  * @bin_buf: The buffer to place args' binary value
2235  * @size: The size of the buffer(by words(32bits), not characters)
2236  * @fmt: The format string to use
2237  * @...: Arguments for the format string
2238  *
2239  * The function returns the number of words(u32) written
2240  * into @bin_buf.
2241  */
2242 int bprintf(u32 *bin_buf, size_t size, const char *fmt, ...)
2243 {
2244         va_list args;
2245         int ret;
2246
2247         va_start(args, fmt);
2248         ret = vbin_printf(bin_buf, size, fmt, args);
2249         va_end(args);
2250
2251         return ret;
2252 }
2253 EXPORT_SYMBOL_GPL(bprintf);
2254
2255 #endif /* CONFIG_BINARY_PRINTF */
2256
2257 /**
2258  * vsscanf - Unformat a buffer into a list of arguments
2259  * @buf:        input buffer
2260  * @fmt:        format of buffer
2261  * @args:       arguments
2262  */
2263 int vsscanf(const char *buf, const char *fmt, va_list args)
2264 {
2265         const char *str = buf;
2266         char *next;
2267         char digit;
2268         int num = 0;
2269         u8 qualifier;
2270         unsigned int base;
2271         union {
2272                 long long s;
2273                 unsigned long long u;
2274         } val;
2275         s16 field_width;
2276         bool is_sign;
2277
2278         while (*fmt) {
2279                 /* skip any white space in format */
2280                 /* white space in format matchs any amount of
2281                  * white space, including none, in the input.
2282                  */
2283                 if (isspace(*fmt)) {
2284                         fmt = skip_spaces(++fmt);
2285                         str = skip_spaces(str);
2286                 }
2287
2288                 /* anything that is not a conversion must match exactly */
2289                 if (*fmt != '%' && *fmt) {
2290                         if (*fmt++ != *str++)
2291                                 break;
2292                         continue;
2293                 }
2294
2295                 if (!*fmt)
2296                         break;
2297                 ++fmt;
2298
2299                 /* skip this conversion.
2300                  * advance both strings to next white space
2301                  */
2302                 if (*fmt == '*') {
2303                         if (!*str)
2304                                 break;
2305                         while (!isspace(*fmt) && *fmt != '%' && *fmt)
2306                                 fmt++;
2307                         while (!isspace(*str) && *str)
2308                                 str++;
2309                         continue;
2310                 }
2311
2312                 /* get field width */
2313                 field_width = -1;
2314                 if (isdigit(*fmt)) {
2315                         field_width = skip_atoi(&fmt);
2316                         if (field_width <= 0)
2317                                 break;
2318                 }
2319
2320                 /* get conversion qualifier */
2321                 qualifier = -1;
2322                 if (*fmt == 'h' || _tolower(*fmt) == 'l' ||
2323                     _tolower(*fmt) == 'z') {
2324                         qualifier = *fmt++;
2325                         if (unlikely(qualifier == *fmt)) {
2326                                 if (qualifier == 'h') {
2327                                         qualifier = 'H';
2328                                         fmt++;
2329                                 } else if (qualifier == 'l') {
2330                                         qualifier = 'L';
2331                                         fmt++;
2332                                 }
2333                         }
2334                 }
2335
2336                 if (!*fmt)
2337                         break;
2338
2339                 if (*fmt == 'n') {
2340                         /* return number of characters read so far */
2341                         *va_arg(args, int *) = str - buf;
2342                         ++fmt;
2343                         continue;
2344                 }
2345
2346                 if (!*str)
2347                         break;
2348
2349                 base = 10;
2350                 is_sign = false;
2351
2352                 switch (*fmt++) {
2353                 case 'c':
2354                 {
2355                         char *s = (char *)va_arg(args, char*);
2356                         if (field_width == -1)
2357                                 field_width = 1;
2358                         do {
2359                                 *s++ = *str++;
2360                         } while (--field_width > 0 && *str);
2361                         num++;
2362                 }
2363                 continue;
2364                 case 's':
2365                 {
2366                         char *s = (char *)va_arg(args, char *);
2367                         if (field_width == -1)
2368                                 field_width = SHRT_MAX;
2369                         /* first, skip leading white space in buffer */
2370                         str = skip_spaces(str);
2371
2372                         /* now copy until next white space */
2373                         while (*str && !isspace(*str) && field_width--)
2374                                 *s++ = *str++;
2375                         *s = '\0';
2376                         num++;
2377                 }
2378                 continue;
2379                 case 'o':
2380                         base = 8;
2381                         break;
2382                 case 'x':
2383                 case 'X':
2384                         base = 16;
2385                         break;
2386                 case 'i':
2387                         base = 0;
2388                 case 'd':
2389                         is_sign = true;
2390                 case 'u':
2391                         break;
2392                 case '%':
2393                         /* looking for '%' in str */
2394                         if (*str++ != '%')
2395                                 return num;
2396                         continue;
2397                 default:
2398                         /* invalid format; stop here */
2399                         return num;
2400                 }
2401
2402                 /* have some sort of integer conversion.
2403                  * first, skip white space in buffer.
2404                  */
2405                 str = skip_spaces(str);
2406
2407                 digit = *str;
2408                 if (is_sign && digit == '-')
2409                         digit = *(str + 1);
2410
2411                 if (!digit
2412                     || (base == 16 && !isxdigit(digit))
2413                     || (base == 10 && !isdigit(digit))
2414                     || (base == 8 && (!isdigit(digit) || digit > '7'))
2415                     || (base == 0 && !isdigit(digit)))
2416                         break;
2417
2418                 if (is_sign)
2419                         val.s = qualifier != 'L' ?
2420                                 simple_strtol(str, &next, base) :
2421                                 simple_strtoll(str, &next, base);
2422                 else
2423                         val.u = qualifier != 'L' ?
2424                                 simple_strtoul(str, &next, base) :
2425                                 simple_strtoull(str, &next, base);
2426
2427                 if (field_width > 0 && next - str > field_width) {
2428                         if (base == 0)
2429                                 _parse_integer_fixup_radix(str, &base);
2430                         while (next - str > field_width) {
2431                                 if (is_sign)
2432                                         val.s = div_s64(val.s, base);
2433                                 else
2434                                         val.u = div_u64(val.u, base);
2435                                 --next;
2436                         }
2437                 }
2438
2439                 switch (qualifier) {
2440                 case 'H':       /* that's 'hh' in format */
2441                         if (is_sign)
2442                                 *va_arg(args, signed char *) = val.s;
2443                         else
2444                                 *va_arg(args, unsigned char *) = val.u;
2445                         break;
2446                 case 'h':
2447                         if (is_sign)
2448                                 *va_arg(args, short *) = val.s;
2449                         else
2450                                 *va_arg(args, unsigned short *) = val.u;
2451                         break;
2452                 case 'l':
2453                         if (is_sign)
2454                                 *va_arg(args, long *) = val.s;
2455                         else
2456                                 *va_arg(args, unsigned long *) = val.u;
2457                         break;
2458                 case 'L':
2459                         if (is_sign)
2460                                 *va_arg(args, long long *) = val.s;
2461                         else
2462                                 *va_arg(args, unsigned long long *) = val.u;
2463                         break;
2464                 case 'Z':
2465                 case 'z':
2466                         *va_arg(args, size_t *) = val.u;
2467                         break;
2468                 default:
2469                         if (is_sign)
2470                                 *va_arg(args, int *) = val.s;
2471                         else
2472                                 *va_arg(args, unsigned int *) = val.u;
2473                         break;
2474                 }
2475                 num++;
2476
2477                 if (!next)
2478                         break;
2479                 str = next;
2480         }
2481
2482         return num;
2483 }
2484 EXPORT_SYMBOL(vsscanf);
2485
2486 /**
2487  * sscanf - Unformat a buffer into a list of arguments
2488  * @buf:        input buffer
2489  * @fmt:        formatting of buffer
2490  * @...:        resulting arguments
2491  */
2492 int sscanf(const char *buf, const char *fmt, ...)
2493 {
2494         va_list args;
2495         int i;
2496
2497         va_start(args, fmt);
2498         i = vsscanf(buf, fmt, args);
2499         va_end(args);
2500
2501         return i;
2502 }
2503 EXPORT_SYMBOL(sscanf);