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  43  * This function is obsolete.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  68  * This function is obsolete.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  82  * This function is obsolete.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  99  * This function is obsolete.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