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/clk.h>
  21 #include <linux/clk-provider.h>
  22 #include <linux/module.h>       /* for KSYM_SYMBOL_LEN */
  23 #include <linux/types.h>
  24 #include <linux/string.h>
  25 #include <linux/ctype.h>
  26 #include <linux/kernel.h>
  27 #include <linux/kallsyms.h>
  28 #include <linux/math64.h>
  29 #include <linux/uaccess.h>
  30 #include <linux/ioport.h>
  31 #include <linux/dcache.h>
  32 #include <linux/cred.h>
  33 #include <linux/uuid.h>
  34 #include <linux/of.h>
  35 #include <net/addrconf.h>
  36 #include <linux/siphash.h>
  37 #include <linux/compiler.h>
  38 #ifdef CONFIG_BLOCK
  39 #include <linux/blkdev.h>
  40 #endif
  41
  42 #include "../mm/internal.h"     /* For the trace_print_flags arrays */
  43
  44 #include <asm/page.h>           /* for PAGE_SIZE */
  45 #include <asm/byteorder.h>      /* cpu_to_le16 */
  46
  47 #include <linux/string_helpers.h>
  48 #include "kstrtox.h"
  49
  50 /**
  51  * simple_strtoull - convert a string to an unsigned long long
  52  * @cp: The start of the string
  53  * @endp: A pointer to the end of the parsed string will be placed here
  54  * @base: The number base to use
  55  *
  56  * This function is obsolete. Please use kstrtoull instead.
  57  */
  58 unsigned long long simple_strtoull(const char *cp, char **endp, unsigned int base)
  59 {
  60         unsigned long long result;
  61         unsigned int rv;
  62
  63         cp = _parse_integer_fixup_radix(cp, &base);
  64         rv = _parse_integer(cp, base, &result);
  65         /* FIXME */
  66         cp += (rv & ~KSTRTOX_OVERFLOW);
  67
  68         if (endp)
  69                 *endp = (char *)cp;
  70
  71         return result;
  72 }
  73 EXPORT_SYMBOL(simple_strtoull);
  74
  75 /**
  76  * simple_strtoul - convert a string to an unsigned long
  77  * @cp: The start of the string
  78  * @endp: A pointer to the end of the parsed string will be placed here
  79  * @base: The number base to use
  80  *
  81  * This function is obsolete. Please use kstrtoul instead.
  82  */
  83 unsigned long simple_strtoul(const char *cp, char **endp, unsigned int base)
  84 {
  85         return simple_strtoull(cp, endp, base);
  86 }
  87 EXPORT_SYMBOL(simple_strtoul);
  88
  89 /**
  90  * simple_strtol - convert a string to a signed long
  91  * @cp: The start of the string
  92  * @endp: A pointer to the end of the parsed string will be placed here
  93  * @base: The number base to use
  94  *
  95  * This function is obsolete. Please use kstrtol instead.
  96  */
  97 long simple_strtol(const char *cp, char **endp, unsigned int base)
  98 {
  99         if (*cp == '-')
 100                 return -simple_strtoul(cp + 1, endp, base);
 101
 102         return simple_strtoul(cp, endp, base);
 103 }
 104 EXPORT_SYMBOL(simple_strtol);
 105
 106 /**
 107  * simple_strtoll - convert a string to a signed long long
 108  * @cp: The start of the string
 109  * @endp: A pointer to the end of the parsed string will be placed here
 110  * @base: The number base to use
 111  *
 112  * This function is obsolete. Please use kstrtoll instead.
 113  */
 114 long long simple_strtoll(const char *cp, char **endp, unsigned int base)
 115 {
 116         if (*cp == '-')
 117                 return -simple_strtoull(cp + 1, endp, base);
 118
 119         return simple_strtoull(cp, endp, base);
 120 }
 121 EXPORT_SYMBOL(simple_strtoll);
 122
 123 static noinline_for_stack
 124 int skip_atoi(const char **s)
 125 {
 126         int i = 0;
 127
 128         do {
 129                 i = i*10 + *((*s)++) - '0';
 130         } while (isdigit(**s));
 131
 132         return i;
 133 }
 134
 135 /*
 136  * Decimal conversion is by far the most typical, and is used for
 137  * /proc and /sys data. This directly impacts e.g. top performance
 138  * with many processes running. We optimize it for speed by emitting
 139  * two characters at a time, using a 200 byte lookup table. This
 140  * roughly halves the number of multiplications compared to computing
 141  * the digits one at a time. Implementation strongly inspired by the
 142  * previous version, which in turn used ideas described at
 143  * <http://www.cs.uiowa.edu/~jones/bcd/divide.html> (with permission
 144  * from the author, Douglas W. Jones).
 145  *
 146  * It turns out there is precisely one 26 bit fixed-point
 147  * approximation a of 64/100 for which x/100 == (x * (u64)a) >> 32
 148  * holds for all x in [0, 10^8-1], namely a = 0x28f5c29. The actual
 149  * range happens to be somewhat larger (x <= 1073741898), but that's
 150  * irrelevant for our purpose.
 151  *
 152  * For dividing a number in the range [10^4, 10^6-1] by 100, we still
 153  * need a 32x32->64 bit multiply, so we simply use the same constant.
 154  *
 155  * For dividing a number in the range [100, 10^4-1] by 100, there are
 156  * several options. The simplest is (x * 0x147b) >> 19, which is valid
 157  * for all x <= 43698.
 158  */
 159
 160 static const u16 decpair[100] = {
 161 #define _(x) (__force u16) cpu_to_le16(((x % 10) | ((x / 10) << 8)) + 0x3030)
 162         _( 0), _( 1), _( 2), _( 3), _( 4), _( 5), _( 6), _( 7), _( 8), _( 9),
 163         _(10), _(11), _(12), _(13), _(14), _(15), _(16), _(17), _(18), _(19),
 164         _(20), _(21), _(22), _(23), _(24), _(25), _(26), _(27), _(28), _(29),
 165         _(30), _(31), _(32), _(33), _(34), _(35), _(36), _(37), _(38), _(39),
 166         _(40), _(41), _(42), _(43), _(44), _(45), _(46), _(47), _(48), _(49),
 167         _(50), _(51), _(52), _(53), _(54), _(55), _(56), _(57), _(58), _(59),
 168         _(60), _(61), _(62), _(63), _(64), _(65), _(66), _(67), _(68), _(69),
 169         _(70), _(71), _(72), _(73), _(74), _(75), _(76), _(77), _(78), _(79),
 170         _(80), _(81), _(82), _(83), _(84), _(85), _(86), _(87), _(88), _(89),
 171         _(90), _(91), _(92), _(93), _(94), _(95), _(96), _(97), _(98), _(99),
 172 #undef _
 173 };
 174
 175 /*
 176  * This will print a single '0' even if r == 0, since we would
 177  * immediately jump to out_r where two 0s would be written but only
 178  * one of them accounted for in buf. This is needed by ip4_string
 179  * below. All other callers pass a non-zero value of r.
 180 */
 181 static noinline_for_stack
 182 char *put_dec_trunc8(char *buf, unsigned r)
 183 {
 184         unsigned q;
 185
 186         /* 1 <= r < 10^8 */
 187         if (r < 100)
 188                 goto out_r;
 189
 190         /* 100 <= r < 10^8 */
 191         q = (r * (u64)0x28f5c29) >> 32;
 192         *((u16 *)buf) = decpair[r - 100*q];
 193         buf += 2;
 194
 195         /* 1 <= q < 10^6 */
 196         if (q < 100)
 197                 goto out_q;
 198
 199         /*  100 <= q < 10^6 */
 200         r = (q * (u64)0x28f5c29) >> 32;
 201         *((u16 *)buf) = decpair[q - 100*r];
 202         buf += 2;
 203
 204         /* 1 <= r < 10^4 */
 205         if (r < 100)
 206                 goto out_r;
 207
 208         /* 100 <= r < 10^4 */
 209         q = (r * 0x147b) >> 19;
 210         *((u16 *)buf) = decpair[r - 100*q];
 211         buf += 2;
 212 out_q:
 213         /* 1 <= q < 100 */
 214         r = q;
 215 out_r:
 216         /* 1 <= r < 100 */
 217         *((u16 *)buf) = decpair[r];
 218         buf += r < 10 ? 1 : 2;
 219         return buf;
 220 }
 221
 222 #if BITS_PER_LONG == 64 && BITS_PER_LONG_LONG == 64
 223 static noinline_for_stack
 224 char *put_dec_full8(char *buf, unsigned r)
 225 {
 226         unsigned q;
 227
 228         /* 0 <= r < 10^8 */
 229         q = (r * (u64)0x28f5c29) >> 32;
 230         *((u16 *)buf) = decpair[r - 100*q];
 231         buf += 2;
 232
 233         /* 0 <= q < 10^6 */
 234         r = (q * (u64)0x28f5c29) >> 32;
 235         *((u16 *)buf) = decpair[q - 100*r];
 236         buf += 2;
 237
 238         /* 0 <= r < 10^4 */
 239         q = (r * 0x147b) >> 19;
 240         *((u16 *)buf) = decpair[r - 100*q];
 241         buf += 2;
 242
 243         /* 0 <= q < 100 */
 244         *((u16 *)buf) = decpair[q];
 245         buf += 2;
 246         return buf;
 247 }
 248
 249 static noinline_for_stack
 250 char *put_dec(char *buf, unsigned long long n)
 251 {
 252         if (n >= 100*1000*1000)
 253                 buf = put_dec_full8(buf, do_div(n, 100*1000*1000));
 254         /* 1 <= n <= 1.6e11 */
 255         if (n >= 100*1000*1000)
 256                 buf = put_dec_full8(buf, do_div(n, 100*1000*1000));
 257         /* 1 <= n < 1e8 */
 258         return put_dec_trunc8(buf, n);
 259 }
 260
 261 #elif BITS_PER_LONG == 32 && BITS_PER_LONG_LONG == 64
 262
 263 static void
 264 put_dec_full4(char *buf, unsigned r)
 265 {
 266         unsigned q;
 267
 268         /* 0 <= r < 10^4 */
 269         q = (r * 0x147b) >> 19;
 270         *((u16 *)buf) = decpair[r - 100*q];
 271         buf += 2;
 272         /* 0 <= q < 100 */
 273         *((u16 *)buf) = decpair[q];
 274 }
 275
 276 /*
 277  * Call put_dec_full4 on x % 10000, return x / 10000.
 278  * The approximation x/10000 == (x * 0x346DC5D7) >> 43
 279  * holds for all x < 1,128,869,999.  The largest value this
 280  * helper will ever be asked to convert is 1,125,520,955.
 281  * (second call in the put_dec code, assuming n is all-ones).
 282  */
 283 static noinline_for_stack
 284 unsigned put_dec_helper4(char *buf, unsigned x)
 285 {
 286         uint32_t q = (x * (uint64_t)0x346DC5D7) >> 43;
 287
 288         put_dec_full4(buf, x - q * 10000);
 289         return q;
 290 }
 291
 292 /* Based on code by Douglas W. Jones found at
 293  * <http://www.cs.uiowa.edu/~jones/bcd/decimal.html#sixtyfour>
 294  * (with permission from the author).
 295  * Performs no 64-bit division and hence should be fast on 32-bit machines.
 296  */
 297 static
 298 char *put_dec(char *buf, unsigned long long n)
 299 {
 300         uint32_t d3, d2, d1, q, h;
 301
 302         if (n < 100*1000*1000)
 303                 return put_dec_trunc8(buf, n);
 304
 305         d1  = ((uint32_t)n >> 16); /* implicit "& 0xffff" */
 306         h   = (n >> 32);
 307         d2  = (h      ) & 0xffff;
 308         d3  = (h >> 16); /* implicit "& 0xffff" */
 309
 310         /* n = 2^48 d3 + 2^32 d2 + 2^16 d1 + d0
 311              = 281_4749_7671_0656 d3 + 42_9496_7296 d2 + 6_5536 d1 + d0 */
 312         q   = 656 * d3 + 7296 * d2 + 5536 * d1 + ((uint32_t)n & 0xffff);
 313         q = put_dec_helper4(buf, q);
 314
 315         q += 7671 * d3 + 9496 * d2 + 6 * d1;
 316         q = put_dec_helper4(buf+4, q);
 317
 318         q += 4749 * d3 + 42 * d2;
 319         q = put_dec_helper4(buf+8, q);
 320
 321         q += 281 * d3;
 322         buf += 12;
 323         if (q)
 324                 buf = put_dec_trunc8(buf, q);
 325         else while (buf[-1] == '0')
 326                 --buf;
 327
 328         return buf;
 329 }
 330
 331 #endif
 332
 333 /*
 334  * Convert passed number to decimal string.
 335  * Returns the length of string.  On buffer overflow, returns 0.
 336  *
 337  * If speed is not important, use snprintf(). It's easy to read the code.
 338  */
 339 int num_to_str(char *buf, int size, unsigned long long num, unsigned int width)
 340 {
 341         /* put_dec requires 2-byte alignment of the buffer. */
 342         char tmp[sizeof(num) * 3] __aligned(2);
 343         int idx, len;
 344
 345         /* put_dec() may work incorrectly for num = 0 (generate "", not "0") */
 346         if (num <= 9) {
 347                 tmp[0] = '0' + num;
 348                 len = 1;
 349         } else {
 350                 len = put_dec(tmp, num) - tmp;
 351         }
 352
 353         if (len > size || width > size)
 354                 return 0;
 355
 356         if (width > len) {
 357                 width = width - len;
 358                 for (idx = 0; idx < width; idx++)
 359                         buf[idx] = ' ';
 360         } else {
 361                 width = 0;
 362         }
 363
 364         for (idx = 0; idx < len; ++idx)
 365                 buf[idx + width] = tmp[len - idx - 1];
 366
 367         return len + width;
 368 }
 369
 370 #define SIGN    1               /* unsigned/signed, must be 1 */
 371 #define LEFT    2               /* left justified */
 372 #define PLUS    4               /* show plus */
 373 #define SPACE   8               /* space if plus */
 374 #define ZEROPAD 16              /* pad with zero, must be 16 == '0' - ' ' */
 375 #define SMALL   32              /* use lowercase in hex (must be 32 == 0x20) */
 376 #define SPECIAL 64              /* prefix hex with "0x", octal with "0" */
 377
 378 enum format_type {
 379         FORMAT_TYPE_NONE, /* Just a string part */
 380         FORMAT_TYPE_WIDTH,
 381         FORMAT_TYPE_PRECISION,
 382         FORMAT_TYPE_CHAR,
 383         FORMAT_TYPE_STR,
 384         FORMAT_TYPE_PTR,
 385         FORMAT_TYPE_PERCENT_CHAR,
 386         FORMAT_TYPE_INVALID,
 387         FORMAT_TYPE_LONG_LONG,
 388         FORMAT_TYPE_ULONG,
 389         FORMAT_TYPE_LONG,
 390         FORMAT_TYPE_UBYTE,
 391         FORMAT_TYPE_BYTE,
 392         FORMAT_TYPE_USHORT,
 393         FORMAT_TYPE_SHORT,
 394         FORMAT_TYPE_UINT,
 395         FORMAT_TYPE_INT,
 396         FORMAT_TYPE_SIZE_T,
 397         FORMAT_TYPE_PTRDIFF
 398 };
 399
 400 struct printf_spec {
 401         unsigned int    type:8;         /* format_type enum */
 402         signed int      field_width:24; /* width of output field */
 403         unsigned int    flags:8;        /* flags to number() */
 404         unsigned int    base:8;         /* number base, 8, 10 or 16 only */
 405         signed int      precision:16;   /* # of digits/chars */
 406 } __packed;
 407 #define FIELD_WIDTH_MAX ((1 << 23) - 1)
 408 #define PRECISION_MAX ((1 << 15) - 1)
 409
 410 static noinline_for_stack
 411 char *number(char *buf, char *end, unsigned long long num,
 412              struct printf_spec spec)
 413 {
 414         /* put_dec requires 2-byte alignment of the buffer. */
 415         char tmp[3 * sizeof(num)] __aligned(2);
 416         char sign;
 417         char locase;
 418         int need_pfx = ((spec.flags & SPECIAL) && spec.base != 10);
 419         int i;
 420         bool is_zero = num == 0LL;
 421         int field_width = spec.field_width;
 422         int precision = spec.precision;
 423
 424         BUILD_BUG_ON(sizeof(struct printf_spec) != 8);
 425
 426         /* locase = 0 or 0x20. ORing digits or letters with 'locase'
 427          * produces same digits or (maybe lowercased) letters */
 428         locase = (spec.flags & SMALL);
 429         if (spec.flags & LEFT)
 430                 spec.flags &= ~ZEROPAD;
 431         sign = 0;
 432         if (spec.flags & SIGN) {
 433                 if ((signed long long)num < 0) {
 434                         sign = '-';
 435                         num = -(signed long long)num;
 436                         field_width--;
 437                 } else if (spec.flags & PLUS) {
 438                         sign = '+';
 439                         field_width--;
 440                 } else if (spec.flags & SPACE) {
 441                         sign = ' ';
 442                         field_width--;
 443                 }
 444         }
 445         if (need_pfx) {
 446                 if (spec.base == 16)
 447                         field_width -= 2;
 448                 else if (!is_zero)
 449                         field_width--;
 450         }
 451
 452         /* generate full string in tmp[], in reverse order */
 453         i = 0;
 454         if (num < spec.base)
 455                 tmp[i++] = hex_asc_upper[num] | locase;
 456         else if (spec.base != 10) { /* 8 or 16 */
 457                 int mask = spec.base - 1;
 458                 int shift = 3;
 459
 460                 if (spec.base == 16)
 461                         shift = 4;
 462                 do {
 463                         tmp[i++] = (hex_asc_upper[((unsigned char)num) & mask] | locase);
 464                         num >>= shift;
 465                 } while (num);
 466         } else { /* base 10 */
 467                 i = put_dec(tmp, num) - tmp;
 468         }
 469
 470         /* printing 100 using %2d gives "100", not "00" */
 471         if (i > precision)
 472                 precision = i;
 473         /* leading space padding */
 474         field_width -= precision;
 475         if (!(spec.flags & (ZEROPAD | LEFT))) {
 476                 while (--field_width >= 0) {
 477                         if (buf < end)
 478                                 *buf = ' ';
 479                         ++buf;
 480                 }
 481         }
 482         /* sign */
 483         if (sign) {
 484                 if (buf < end)
 485                         *buf = sign;
 486                 ++buf;
 487         }
 488         /* "0x" / "0" prefix */
 489         if (need_pfx) {
 490                 if (spec.base == 16 || !is_zero) {
 491                         if (buf < end)
 492                                 *buf = '0';
 493                         ++buf;
 494                 }
 495                 if (spec.base == 16) {
 496                         if (buf < end)
 497                                 *buf = ('X' | locase);
 498                         ++buf;
 499                 }
 500         }
 501         /* zero or space padding */
 502         if (!(spec.flags & LEFT)) {
 503                 char c = ' ' + (spec.flags & ZEROPAD);
 504                 BUILD_BUG_ON(' ' + ZEROPAD != '0');
 505                 while (--field_width >= 0) {
 506                         if (buf < end)
 507                                 *buf = c;
 508                         ++buf;
 509                 }
 510         }
 511         /* hmm even more zero padding? */
 512         while (i <= --precision) {
 513                 if (buf < end)
 514                         *buf = '0';
 515                 ++buf;
 516         }
 517         /* actual digits of result */
 518         while (--i >= 0) {
 519                 if (buf < end)
 520                         *buf = tmp[i];
 521                 ++buf;
 522         }
 523         /* trailing space padding */
 524         while (--field_width >= 0) {
 525                 if (buf < end)
 526                         *buf = ' ';
 527                 ++buf;
 528         }
 529
 530         return buf;
 531 }
 532
 533 static noinline_for_stack
 534 char *special_hex_number(char *buf, char *end, unsigned long long num, int size)
 535 {
 536         struct printf_spec spec;
 537
 538         spec.type = FORMAT_TYPE_PTR;
 539         spec.field_width = 2 + 2 * size;        /* 0x + hex */
 540         spec.flags = SPECIAL | SMALL | ZEROPAD;
 541         spec.base = 16;
 542         spec.precision = -1;
 543
 544         return number(buf, end, num, spec);
 545 }
 546
 547 static void move_right(char *buf, char *end, unsigned len, unsigned spaces)
 548 {
 549         size_t size;
 550         if (buf >= end) /* nowhere to put anything */
 551                 return;
 552         size = end - buf;
 553         if (size <= spaces) {
 554                 memset(buf, ' ', size);
 555                 return;
 556         }
 557         if (len) {
 558                 if (len > size - spaces)
 559                         len = size - spaces;
 560                 memmove(buf + spaces, buf, len);
 561         }
 562         memset(buf, ' ', spaces);
 563 }
 564
 565 /*
 566  * Handle field width padding for a string.
 567  * @buf: current buffer position
 568  * @n: length of string
 569  * @end: end of output buffer
 570  * @spec: for field width and flags
 571  * Returns: new buffer position after padding.
 572  */
 573 static noinline_for_stack
 574 char *widen_string(char *buf, int n, char *end, struct printf_spec spec)
 575 {
 576         unsigned spaces;
 577
 578         if (likely(n >= spec.field_width))
 579                 return buf;
 580         /* we want to pad the sucker */
 581         spaces = spec.field_width - n;
 582         if (!(spec.flags & LEFT)) {
 583                 move_right(buf - n, end, n, spaces);
 584                 return buf + spaces;
 585         }
 586         while (spaces--) {
 587                 if (buf < end)
 588                         *buf = ' ';
 589                 ++buf;
 590         }
 591         return buf;
 592 }
 593
 594 static noinline_for_stack
 595 char *string(char *buf, char *end, const char *s, struct printf_spec spec)
 596 {
 597         int len = 0;
 598         size_t lim = spec.precision;
 599
 600         if ((unsigned long)s < PAGE_SIZE)
 601                 s = "(null)";
 602
 603         while (lim--) {
 604                 char c = *s++;
 605                 if (!c)
 606                         break;
 607                 if (buf < end)
 608                         *buf = c;
 609                 ++buf;
 610                 ++len;
 611         }
 612         return widen_string(buf, len, end, spec);
 613 }
 614
 615 static noinline_for_stack
 616 char *dentry_name(char *buf, char *end, const struct dentry *d, struct printf_spec spec,
 617                   const char *fmt)
 618 {
 619         const char *array[4], *s;
 620         const struct dentry *p;
 621         int depth;
 622         int i, n;
 623
 624         switch (fmt[1]) {
 625                 case '2': case '3': case '4':
 626                         depth = fmt[1] - '0';
 627                         break;
 628                 default:
 629                         depth = 1;
 630         }
 631
 632         rcu_read_lock();
 633         for (i = 0; i < depth; i++, d = p) {
 634                 p = READ_ONCE(d->d_parent);
 635                 array[i] = READ_ONCE(d->d_name.name);
 636                 if (p == d) {
 637                         if (i)
 638                                 array[i] = "";
 639                         i++;
 640                         break;
 641                 }
 642         }
 643         s = array[--i];
 644         for (n = 0; n != spec.precision; n++, buf++) {
 645                 char c = *s++;
 646                 if (!c) {
 647                         if (!i)
 648                                 break;
 649                         c = '/';
 650                         s = array[--i];
 651                 }
 652                 if (buf < end)
 653                         *buf = c;
 654         }
 655         rcu_read_unlock();
 656         return widen_string(buf, n, end, spec);
 657 }
 658
 659 #ifdef CONFIG_BLOCK
 660 static noinline_for_stack
 661 char *bdev_name(char *buf, char *end, struct block_device *bdev,
 662                 struct printf_spec spec, const char *fmt)
 663 {
 664         struct gendisk *hd = bdev->bd_disk;
 665
 666         buf = string(buf, end, hd->disk_name, spec);
 667         if (bdev->bd_part->partno) {
 668                 if (isdigit(hd->disk_name[strlen(hd->disk_name)-1])) {
 669                         if (buf < end)
 670                                 *buf = 'p';
 671                         buf++;
 672                 }
 673                 buf = number(buf, end, bdev->bd_part->partno, spec);
 674         }
 675         return buf;
 676 }
 677 #endif
 678
 679 static noinline_for_stack
 680 char *symbol_string(char *buf, char *end, void *ptr,
 681                     struct printf_spec spec, const char *fmt)
 682 {
 683         unsigned long value;
 684 #ifdef CONFIG_KALLSYMS
 685         char sym[KSYM_SYMBOL_LEN];
 686 #endif
 687
 688         if (fmt[1] == 'R')
 689                 ptr = __builtin_extract_return_addr(ptr);
 690         value = (unsigned long)ptr;
 691
 692 #ifdef CONFIG_KALLSYMS
 693         if (*fmt == 'B')
 694                 sprint_backtrace(sym, value);
 695         else if (*fmt != 'f' && *fmt != 's')
 696                 sprint_symbol(sym, value);
 697         else
 698                 sprint_symbol_no_offset(sym, value);
 699
 700         return string(buf, end, sym, spec);
 701 #else
 702         return special_hex_number(buf, end, value, sizeof(void *));
 703 #endif
 704 }
 705
 706 static const struct printf_spec default_str_spec = {
 707         .field_width = -1,
 708         .precision = -1,
 709 };
 710
 711 static const struct printf_spec default_flag_spec = {
 712         .base = 16,
 713         .precision = -1,
 714         .flags = SPECIAL | SMALL,
 715 };
 716
 717 static const struct printf_spec default_dec_spec = {
 718         .base = 10,
 719         .precision = -1,
 720 };
 721
 722 static noinline_for_stack
 723 char *resource_string(char *buf, char *end, struct resource *res,
 724                       struct printf_spec spec, const char *fmt)
 725 {
 726 #ifndef IO_RSRC_PRINTK_SIZE
 727 #define IO_RSRC_PRINTK_SIZE     6
 728 #endif
 729
 730 #ifndef MEM_RSRC_PRINTK_SIZE
 731 #define MEM_RSRC_PRINTK_SIZE    10
 732 #endif
 733         static const struct printf_spec io_spec = {
 734                 .base = 16,
 735                 .field_width = IO_RSRC_PRINTK_SIZE,
 736                 .precision = -1,
 737                 .flags = SPECIAL | SMALL | ZEROPAD,
 738         };
 739         static const struct printf_spec mem_spec = {
 740                 .base = 16,
 741                 .field_width = MEM_RSRC_PRINTK_SIZE,
 742                 .precision = -1,
 743                 .flags = SPECIAL | SMALL | ZEROPAD,
 744         };
 745         static const struct printf_spec bus_spec = {
 746                 .base = 16,
 747                 .field_width = 2,
 748                 .precision = -1,
 749                 .flags = SMALL | ZEROPAD,
 750         };
 751         static const struct printf_spec str_spec = {
 752                 .field_width = -1,
 753                 .precision = 10,
 754                 .flags = LEFT,
 755         };
 756
 757         /* 32-bit res (sizeof==4): 10 chars in dec, 10 in hex ("0x" + 8)
 758          * 64-bit res (sizeof==8): 20 chars in dec, 18 in hex ("0x" + 16) */
 759 #define RSRC_BUF_SIZE           ((2 * sizeof(resource_size_t)) + 4)
 760 #define FLAG_BUF_SIZE           (2 * sizeof(res->flags))
 761 #define DECODED_BUF_SIZE        sizeof("[mem - 64bit pref window disabled]")
 762 #define RAW_BUF_SIZE            sizeof("[mem - flags 0x]")
 763         char sym[max(2*RSRC_BUF_SIZE + DECODED_BUF_SIZE,
 764                      2*RSRC_BUF_SIZE + FLAG_BUF_SIZE + RAW_BUF_SIZE)];
 765
 766         char *p = sym, *pend = sym + sizeof(sym);
 767         int decode = (fmt[0] == 'R') ? 1 : 0;
 768         const struct printf_spec *specp;
 769
 770         *p++ = '[';
 771         if (res->flags & IORESOURCE_IO) {
 772                 p = string(p, pend, "io  ", str_spec);
 773                 specp = &io_spec;
 774         } else if (res->flags & IORESOURCE_MEM) {
 775                 p = string(p, pend, "mem ", str_spec);
 776                 specp = &mem_spec;
 777         } else if (res->flags & IORESOURCE_IRQ) {
 778                 p = string(p, pend, "irq ", str_spec);
 779                 specp = &default_dec_spec;
 780         } else if (res->flags & IORESOURCE_DMA) {
 781                 p = string(p, pend, "dma ", str_spec);
 782                 specp = &default_dec_spec;
 783         } else if (res->flags & IORESOURCE_BUS) {
 784                 p = string(p, pend, "bus ", str_spec);
 785                 specp = &bus_spec;
 786         } else {
 787                 p = string(p, pend, "??? ", str_spec);
 788                 specp = &mem_spec;
 789                 decode = 0;
 790         }
 791         if (decode && res->flags & IORESOURCE_UNSET) {
 792                 p = string(p, pend, "size ", str_spec);
 793                 p = number(p, pend, resource_size(res), *specp);
 794         } else {
 795                 p = number(p, pend, res->start, *specp);
 796                 if (res->start != res->end) {
 797                         *p++ = '-';
 798                         p = number(p, pend, res->end, *specp);
 799                 }
 800         }
 801         if (decode) {
 802                 if (res->flags & IORESOURCE_MEM_64)
 803                         p = string(p, pend, " 64bit", str_spec);
 804                 if (res->flags & IORESOURCE_PREFETCH)
 805                         p = string(p, pend, " pref", str_spec);
 806                 if (res->flags & IORESOURCE_WINDOW)
 807                         p = string(p, pend, " window", str_spec);
 808                 if (res->flags & IORESOURCE_DISABLED)
 809                         p = string(p, pend, " disabled", str_spec);
 810         } else {
 811                 p = string(p, pend, " flags ", str_spec);
 812                 p = number(p, pend, res->flags, default_flag_spec);
 813         }
 814         *p++ = ']';
 815         *p = '\0';
 816
 817         return string(buf, end, sym, spec);
 818 }
 819
 820 static noinline_for_stack
 821 char *hex_string(char *buf, char *end, u8 *addr, struct printf_spec spec,
 822                  const char *fmt)
 823 {
 824         int i, len = 1;         /* if we pass '%ph[CDN]', field width remains
 825                                    negative value, fallback to the default */
 826         char separator;
 827
 828         if (spec.field_width == 0)
 829                 /* nothing to print */
 830                 return buf;
 831
 832         if (ZERO_OR_NULL_PTR(addr))
 833                 /* NULL pointer */
 834                 return string(buf, end, NULL, spec);
 835
 836         switch (fmt[1]) {
 837         case 'C':
 838                 separator = ':';
 839                 break;
 840         case 'D':
 841                 separator = '-';
 842                 break;
 843         case 'N':
 844                 separator = 0;
 845                 break;
 846         default:
 847                 separator = ' ';
 848                 break;
 849         }
 850
 851         if (spec.field_width > 0)
 852                 len = min_t(int, spec.field_width, 64);
 853
 854         for (i = 0; i < len; ++i) {
 855                 if (buf < end)
 856                         *buf = hex_asc_hi(addr[i]);
 857                 ++buf;
 858                 if (buf < end)
 859                         *buf = hex_asc_lo(addr[i]);
 860                 ++buf;
 861
 862                 if (separator && i != len - 1) {
 863                         if (buf < end)
 864                                 *buf = separator;
 865                         ++buf;
 866                 }
 867         }
 868
 869         return buf;
 870 }
 871
 872 static noinline_for_stack
 873 char *bitmap_string(char *buf, char *end, unsigned long *bitmap,
 874                     struct printf_spec spec, const char *fmt)
 875 {
 876         const int CHUNKSZ = 32;
 877         int nr_bits = max_t(int, spec.field_width, 0);
 878         int i, chunksz;
 879         bool first = true;
 880
 881         /* reused to print numbers */
 882         spec = (struct printf_spec){ .flags = SMALL | ZEROPAD, .base = 16 };
 883
 884         chunksz = nr_bits & (CHUNKSZ - 1);
 885         if (chunksz == 0)
 886                 chunksz = CHUNKSZ;
 887
 888         i = ALIGN(nr_bits, CHUNKSZ) - CHUNKSZ;
 889         for (; i >= 0; i -= CHUNKSZ) {
 890                 u32 chunkmask, val;
 891                 int word, bit;
 892
 893                 chunkmask = ((1ULL << chunksz) - 1);
 894                 word = i / BITS_PER_LONG;
 895                 bit = i % BITS_PER_LONG;
 896                 val = (bitmap[word] >> bit) & chunkmask;
 897
 898                 if (!first) {
 899                         if (buf < end)
 900                                 *buf = ',';
 901                         buf++;
 902                 }
 903                 first = false;
 904
 905                 spec.field_width = DIV_ROUND_UP(chunksz, 4);
 906                 buf = number(buf, end, val, spec);
 907
 908                 chunksz = CHUNKSZ;
 909         }
 910         return buf;
 911 }
 912
 913 static noinline_for_stack
 914 char *bitmap_list_string(char *buf, char *end, unsigned long *bitmap,
 915                          struct printf_spec spec, const char *fmt)
 916 {
 917         int nr_bits = max_t(int, spec.field_width, 0);
 918         /* current bit is 'cur', most recently seen range is [rbot, rtop] */
 919         int cur, rbot, rtop;
 920         bool first = true;
 921
 922         rbot = cur = find_first_bit(bitmap, nr_bits);
 923         while (cur < nr_bits) {
 924                 rtop = cur;
 925                 cur = find_next_bit(bitmap, nr_bits, cur + 1);
 926                 if (cur < nr_bits && cur <= rtop + 1)
 927                         continue;
 928
 929                 if (!first) {
 930                         if (buf < end)
 931                                 *buf = ',';
 932                         buf++;
 933                 }
 934                 first = false;
 935
 936                 buf = number(buf, end, rbot, default_dec_spec);
 937                 if (rbot < rtop) {
 938                         if (buf < end)
 939                                 *buf = '-';
 940                         buf++;
 941
 942                         buf = number(buf, end, rtop, default_dec_spec);
 943                 }
 944
 945                 rbot = cur;
 946         }
 947         return buf;
 948 }
 949
 950 static noinline_for_stack
 951 char *mac_address_string(char *buf, char *end, u8 *addr,
 952                          struct printf_spec spec, const char *fmt)
 953 {
 954         char mac_addr[sizeof("xx:xx:xx:xx:xx:xx")];
 955         char *p = mac_addr;
 956         int i;
 957         char separator;
 958         bool reversed = false;
 959
 960         switch (fmt[1]) {
 961         case 'F':
 962                 separator = '-';
 963                 break;
 964
 965         case 'R':
 966                 reversed = true;
 967                 /* fall through */
 968
 969         default:
 970                 separator = ':';
 971                 break;
 972         }
 973
 974         for (i = 0; i < 6; i++) {
 975                 if (reversed)
 976                         p = hex_byte_pack(p, addr[5 - i]);
 977                 else
 978                         p = hex_byte_pack(p, addr[i]);
 979
 980                 if (fmt[0] == 'M' && i != 5)
 981                         *p++ = separator;
 982         }
 983         *p = '\0';
 984
 985         return string(buf, end, mac_addr, spec);
 986 }
 987
 988 static noinline_for_stack
 989 char *ip4_string(char *p, const u8 *addr, const char *fmt)
 990 {
 991         int i;
 992         bool leading_zeros = (fmt[0] == 'i');
 993         int index;
 994         int step;
 995
 996         switch (fmt[2]) {
 997         case 'h':
 998 #ifdef __BIG_ENDIAN
 999                 index = 0;
1000                 step = 1;
1001 #else
1002                 index = 3;
1003                 step = -1;
1004 #endif
1005                 break;
1006         case 'l':
1007                 index = 3;
1008                 step = -1;
1009                 break;
1010         case 'n':
1011         case 'b':
1012         default:
1013                 index = 0;
1014                 step = 1;
1015                 break;
1016         }
1017         for (i = 0; i < 4; i++) {
1018                 char temp[4] __aligned(2);      /* hold each IP quad in reverse order */
1019                 int digits = put_dec_trunc8(temp, addr[index]) - temp;
1020                 if (leading_zeros) {
1021                         if (digits < 3)
1022                                 *p++ = '0';
1023                         if (digits < 2)
1024                                 *p++ = '0';
1025                 }
1026                 /* reverse the digits in the quad */
1027                 while (digits--)
1028                         *p++ = temp[digits];
1029                 if (i < 3)
1030                         *p++ = '.';
1031                 index += step;
1032         }
1033         *p = '\0';
1034
1035         return p;
1036 }
1037
1038 static noinline_for_stack
1039 char *ip6_compressed_string(char *p, const char *addr)
1040 {
1041         int i, j, range;
1042         unsigned char zerolength[8];
1043         int longest = 1;
1044         int colonpos = -1;
1045         u16 word;
1046         u8 hi, lo;
1047         bool needcolon = false;
1048         bool useIPv4;
1049         struct in6_addr in6;
1050
1051         memcpy(&in6, addr, sizeof(struct in6_addr));
1052
1053         useIPv4 = ipv6_addr_v4mapped(&in6) || ipv6_addr_is_isatap(&in6);
1054
1055         memset(zerolength, 0, sizeof(zerolength));
1056
1057         if (useIPv4)
1058                 range = 6;
1059         else
1060                 range = 8;
1061
1062         /* find position of longest 0 run */
1063         for (i = 0; i < range; i++) {
1064                 for (j = i; j < range; j++) {
1065                         if (in6.s6_addr16[j] != 0)
1066                                 break;
1067                         zerolength[i]++;
1068                 }
1069         }
1070         for (i = 0; i < range; i++) {
1071                 if (zerolength[i] > longest) {
1072                         longest = zerolength[i];
1073                         colonpos = i;
1074                 }
1075         }
1076         if (longest == 1)               /* don't compress a single 0 */
1077                 colonpos = -1;
1078
1079         /* emit address */
1080         for (i = 0; i < range; i++) {
1081                 if (i == colonpos) {
1082                         if (needcolon || i == 0)
1083                                 *p++ = ':';
1084                         *p++ = ':';
1085                         needcolon = false;
1086                         i += longest - 1;
1087                         continue;
1088                 }
1089                 if (needcolon) {
1090                         *p++ = ':';
1091                         needcolon = false;
1092                 }
1093                 /* hex u16 without leading 0s */
1094                 word = ntohs(in6.s6_addr16[i]);
1095                 hi = word >> 8;
1096                 lo = word & 0xff;
1097                 if (hi) {
1098                         if (hi > 0x0f)
1099                                 p = hex_byte_pack(p, hi);
1100                         else
1101                                 *p++ = hex_asc_lo(hi);
1102                         p = hex_byte_pack(p, lo);
1103                 }
1104                 else if (lo > 0x0f)
1105                         p = hex_byte_pack(p, lo);
1106                 else
1107                         *p++ = hex_asc_lo(lo);
1108                 needcolon = true;
1109         }
1110
1111         if (useIPv4) {
1112                 if (needcolon)
1113                         *p++ = ':';
1114                 p = ip4_string(p, &in6.s6_addr[12], "I4");
1115         }
1116         *p = '\0';
1117
1118         return p;
1119 }
1120
1121 static noinline_for_stack
1122 char *ip6_string(char *p, const char *addr, const char *fmt)
1123 {
1124         int i;
1125
1126         for (i = 0; i < 8; i++) {
1127                 p = hex_byte_pack(p, *addr++);
1128                 p = hex_byte_pack(p, *addr++);
1129                 if (fmt[0] == 'I' && i != 7)
1130                         *p++ = ':';
1131         }
1132         *p = '\0';
1133
1134         return p;
1135 }
1136
1137 static noinline_for_stack
1138 char *ip6_addr_string(char *buf, char *end, const u8 *addr,
1139                       struct printf_spec spec, const char *fmt)
1140 {
1141         char ip6_addr[sizeof("xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255")];
1142
1143         if (fmt[0] == 'I' && fmt[2] == 'c')
1144                 ip6_compressed_string(ip6_addr, addr);
1145         else
1146                 ip6_string(ip6_addr, addr, fmt);
1147
1148         return string(buf, end, ip6_addr, spec);
1149 }
1150
1151 static noinline_for_stack
1152 char *ip4_addr_string(char *buf, char *end, const u8 *addr,
1153                       struct printf_spec spec, const char *fmt)
1154 {
1155         char ip4_addr[sizeof("255.255.255.255")];
1156
1157         ip4_string(ip4_addr, addr, fmt);
1158
1159         return string(buf, end, ip4_addr, spec);
1160 }
1161
1162 static noinline_for_stack
1163 char *ip6_addr_string_sa(char *buf, char *end, const struct sockaddr_in6 *sa,
1164                          struct printf_spec spec, const char *fmt)
1165 {
1166         bool have_p = false, have_s = false, have_f = false, have_c = false;
1167         char ip6_addr[sizeof("[xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255]") +
1168                       sizeof(":12345") + sizeof("/123456789") +
1169                       sizeof("%1234567890")];
1170         char *p = ip6_addr, *pend = ip6_addr + sizeof(ip6_addr);
1171         const u8 *addr = (const u8 *) &sa->sin6_addr;
1172         char fmt6[2] = { fmt[0], '6' };
1173         u8 off = 0;
1174
1175         fmt++;
1176         while (isalpha(*++fmt)) {
1177                 switch (*fmt) {
1178                 case 'p':
1179                         have_p = true;
1180                         break;
1181                 case 'f':
1182                         have_f = true;
1183                         break;
1184                 case 's':
1185                         have_s = true;
1186                         break;
1187                 case 'c':
1188                         have_c = true;
1189                         break;
1190                 }
1191         }
1192
1193         if (have_p || have_s || have_f) {
1194                 *p = '[';
1195                 off = 1;
1196         }
1197
1198         if (fmt6[0] == 'I' && have_c)
1199                 p = ip6_compressed_string(ip6_addr + off, addr);
1200         else
1201                 p = ip6_string(ip6_addr + off, addr, fmt6);
1202
1203         if (have_p || have_s || have_f)
1204                 *p++ = ']';
1205
1206         if (have_p) {
1207                 *p++ = ':';
1208                 p = number(p, pend, ntohs(sa->sin6_port), spec);
1209         }
1210         if (have_f) {
1211                 *p++ = '/';
1212                 p = number(p, pend, ntohl(sa->sin6_flowinfo &
1213                                           IPV6_FLOWINFO_MASK), spec);
1214         }
1215         if (have_s) {
1216                 *p++ = '%';
1217                 p = number(p, pend, sa->sin6_scope_id, spec);
1218         }
1219         *p = '\0';
1220
1221         return string(buf, end, ip6_addr, spec);
1222 }
1223
1224 static noinline_for_stack
1225 char *ip4_addr_string_sa(char *buf, char *end, const struct sockaddr_in *sa,
1226                          struct printf_spec spec, const char *fmt)
1227 {
1228         bool have_p = false;
1229         char *p, ip4_addr[sizeof("255.255.255.255") + sizeof(":12345")];
1230         char *pend = ip4_addr + sizeof(ip4_addr);
1231         const u8 *addr = (const u8 *) &sa->sin_addr.s_addr;
1232         char fmt4[3] = { fmt[0], '4', 0 };
1233
1234         fmt++;
1235         while (isalpha(*++fmt)) {
1236                 switch (*fmt) {
1237                 case 'p':
1238                         have_p = true;
1239                         break;
1240                 case 'h':
1241                 case 'l':
1242                 case 'n':
1243                 case 'b':
1244                         fmt4[2] = *fmt;
1245                         break;
1246                 }
1247         }
1248
1249         p = ip4_string(ip4_addr, addr, fmt4);
1250         if (have_p) {
1251                 *p++ = ':';
1252                 p = number(p, pend, ntohs(sa->sin_port), spec);
1253         }
1254         *p = '\0';
1255
1256         return string(buf, end, ip4_addr, spec);
1257 }
1258
1259 static noinline_for_stack
1260 char *escaped_string(char *buf, char *end, u8 *addr, struct printf_spec spec,
1261                      const char *fmt)
1262 {
1263         bool found = true;
1264         int count = 1;
1265         unsigned int flags = 0;
1266         int len;
1267
1268         if (spec.field_width == 0)
1269                 return buf;                             /* nothing to print */
1270
1271         if (ZERO_OR_NULL_PTR(addr))
1272                 return string(buf, end, NULL, spec);    /* NULL pointer */
1273
1274
1275         do {
1276                 switch (fmt[count++]) {
1277                 case 'a':
1278                         flags |= ESCAPE_ANY;
1279                         break;
1280                 case 'c':
1281                         flags |= ESCAPE_SPECIAL;
1282                         break;
1283                 case 'h':
1284                         flags |= ESCAPE_HEX;
1285                         break;
1286                 case 'n':
1287                         flags |= ESCAPE_NULL;
1288                         break;
1289                 case 'o':
1290                         flags |= ESCAPE_OCTAL;
1291                         break;
1292                 case 'p':
1293                         flags |= ESCAPE_NP;
1294                         break;
1295                 case 's':
1296                         flags |= ESCAPE_SPACE;
1297                         break;
1298                 default:
1299                         found = false;
1300                         break;
1301                 }
1302         } while (found);
1303
1304         if (!flags)
1305                 flags = ESCAPE_ANY_NP;
1306
1307         len = spec.field_width < 0 ? 1 : spec.field_width;
1308
1309         /*
1310          * string_escape_mem() writes as many characters as it can to
1311          * the given buffer, and returns the total size of the output
1312          * had the buffer been big enough.
1313          */
1314         buf += string_escape_mem(addr, len, buf, buf < end ? end - buf : 0, flags, NULL);
1315
1316         return buf;
1317 }
1318
1319 static noinline_for_stack
1320 char *uuid_string(char *buf, char *end, const u8 *addr,
1321                   struct printf_spec spec, const char *fmt)
1322 {
1323         char uuid[UUID_STRING_LEN + 1];
1324         char *p = uuid;
1325         int i;
1326         const u8 *index = uuid_index;
1327         bool uc = false;
1328
1329         switch (*(++fmt)) {
1330         case 'L':
1331                 uc = true;              /* fall-through */
1332         case 'l':
1333                 index = guid_index;
1334                 break;
1335         case 'B':
1336                 uc = true;
1337                 break;
1338         }
1339
1340         for (i = 0; i < 16; i++) {
1341                 if (uc)
1342                         p = hex_byte_pack_upper(p, addr[index[i]]);
1343                 else
1344                         p = hex_byte_pack(p, addr[index[i]]);
1345                 switch (i) {
1346                 case 3:
1347                 case 5:
1348                 case 7:
1349                 case 9:
1350                         *p++ = '-';
1351                         break;
1352                 }
1353         }
1354
1355         *p = 0;
1356
1357         return string(buf, end, uuid, spec);
1358 }
1359
1360 static noinline_for_stack
1361 char *pointer_string(char *buf, char *end, const void *ptr,
1362                      struct printf_spec spec)
1363 {
1364         spec.base = 16;
1365         spec.flags |= SMALL;
1366         if (spec.field_width == -1) {
1367                 spec.field_width = 2 * sizeof(ptr);
1368                 spec.flags |= ZEROPAD;
1369         }
1370
1371         return number(buf, end, (unsigned long int)ptr, spec);
1372 }
1373
1374 int kptr_restrict __read_mostly;
1375
1376 static noinline_for_stack
1377 char *restricted_pointer(char *buf, char *end, const void *ptr,
1378                          struct printf_spec spec)
1379 {
1380         switch (kptr_restrict) {
1381         case 0:
1382                 /* Always print %pK values */
1383                 break;
1384         case 1: {
1385                 const struct cred *cred;
1386
1387                 /*
1388                  * kptr_restrict==1 cannot be used in IRQ context
1389                  * because its test for CAP_SYSLOG would be meaningless.
1390                  */
1391                 if (in_irq() || in_serving_softirq() || in_nmi()) {
1392                         if (spec.field_width == -1)
1393                                 spec.field_width = 2 * sizeof(ptr);
1394                         return string(buf, end, "pK-error", spec);
1395                 }
1396
1397                 /*
1398                  * Only print the real pointer value if the current
1399                  * process has CAP_SYSLOG and is running with the
1400                  * same credentials it started with. This is because
1401                  * access to files is checked at open() time, but %pK
1402                  * checks permission at read() time. We don't want to
1403                  * leak pointer values if a binary opens a file using
1404                  * %pK and then elevates privileges before reading it.
1405                  */
1406                 cred = current_cred();
1407                 if (!has_capability_noaudit(current, CAP_SYSLOG) ||
1408                     !uid_eq(cred->euid, cred->uid) ||
1409                     !gid_eq(cred->egid, cred->gid))
1410                         ptr = NULL;
1411                 break;
1412         }
1413         case 2:
1414         default:
1415                 /* Always print 0's for %pK */
1416                 ptr = NULL;
1417                 break;
1418         }
1419
1420         return pointer_string(buf, end, ptr, spec);
1421 }
1422
1423 static noinline_for_stack
1424 char *netdev_bits(char *buf, char *end, const void *addr, const char *fmt)
1425 {
1426         unsigned long long num;
1427         int size;
1428
1429         switch (fmt[1]) {
1430         case 'F':
1431                 num = *(const netdev_features_t *)addr;
1432                 size = sizeof(netdev_features_t);
1433                 break;
1434         default:
1435                 num = (unsigned long)addr;
1436                 size = sizeof(unsigned long);
1437                 break;
1438         }
1439
1440         return special_hex_number(buf, end, num, size);
1441 }
1442
1443 static noinline_for_stack
1444 char *address_val(char *buf, char *end, const void *addr, const char *fmt)
1445 {
1446         unsigned long long num;
1447         int size;
1448
1449         switch (fmt[1]) {
1450         case 'd':
1451                 num = *(const dma_addr_t *)addr;
1452                 size = sizeof(dma_addr_t);
1453                 break;
1454         case 'p':
1455         default:
1456                 num = *(const phys_addr_t *)addr;
1457                 size = sizeof(phys_addr_t);
1458                 break;
1459         }
1460
1461         return special_hex_number(buf, end, num, size);
1462 }
1463
1464 static noinline_for_stack
1465 char *clock(char *buf, char *end, struct clk *clk, struct printf_spec spec,
1466             const char *fmt)
1467 {
1468         if (!IS_ENABLED(CONFIG_HAVE_CLK) || !clk)
1469                 return string(buf, end, NULL, spec);
1470
1471         switch (fmt[1]) {
1472         case 'n':
1473         default:
1474 #ifdef CONFIG_COMMON_CLK
1475                 return string(buf, end, __clk_get_name(clk), spec);
1476 #else
1477                 return special_hex_number(buf, end, (unsigned long)clk, sizeof(unsigned long));
1478 #endif
1479         }
1480 }
1481
1482 static
1483 char *format_flags(char *buf, char *end, unsigned long flags,
1484                                         const struct trace_print_flags *names)
1485 {
1486         unsigned long mask;
1487
1488         for ( ; flags && names->name; names++) {
1489                 mask = names->mask;
1490                 if ((flags & mask) != mask)
1491                         continue;
1492
1493                 buf = string(buf, end, names->name, default_str_spec);
1494
1495                 flags &= ~mask;
1496                 if (flags) {
1497                         if (buf < end)
1498                                 *buf = '|';
1499                         buf++;
1500                 }
1501         }
1502
1503         if (flags)
1504                 buf = number(buf, end, flags, default_flag_spec);
1505
1506         return buf;
1507 }
1508
1509 static noinline_for_stack
1510 char *flags_string(char *buf, char *end, void *flags_ptr, const char *fmt)
1511 {
1512         unsigned long flags;
1513         const struct trace_print_flags *names;
1514
1515         switch (fmt[1]) {
1516         case 'p':
1517                 flags = *(unsigned long *)flags_ptr;
1518                 /* Remove zone id */
1519                 flags &= (1UL << NR_PAGEFLAGS) - 1;
1520                 names = pageflag_names;
1521                 break;
1522         case 'v':
1523                 flags = *(unsigned long *)flags_ptr;
1524                 names = vmaflag_names;
1525                 break;
1526         case 'g':
1527                 flags = *(gfp_t *)flags_ptr;
1528                 names = gfpflag_names;
1529                 break;
1530         default:
1531                 WARN_ONCE(1, "Unsupported flags modifier: %c\n", fmt[1]);
1532                 return buf;
1533         }
1534
1535         return format_flags(buf, end, flags, names);
1536 }
1537
1538 static const char *device_node_name_for_depth(const struct device_node *np, int depth)
1539 {
1540         for ( ; np && depth; depth--)
1541                 np = np->parent;
1542
1543         return kbasename(np->full_name);
1544 }
1545
1546 static noinline_for_stack
1547 char *device_node_gen_full_name(const struct device_node *np, char *buf, char *end)
1548 {
1549         int depth;
1550         const struct device_node *parent = np->parent;
1551
1552         /* special case for root node */
1553         if (!parent)
1554                 return string(buf, end, "/", default_str_spec);
1555
1556         for (depth = 0; parent->parent; depth++)
1557                 parent = parent->parent;
1558
1559         for ( ; depth >= 0; depth--) {
1560                 buf = string(buf, end, "/", default_str_spec);
1561                 buf = string(buf, end, device_node_name_for_depth(np, depth),
1562                              default_str_spec);
1563         }
1564         return buf;
1565 }
1566
1567 static noinline_for_stack
1568 char *device_node_string(char *buf, char *end, struct device_node *dn,
1569                          struct printf_spec spec, const char *fmt)
1570 {
1571         char tbuf[sizeof("xxxx") + 1];
1572         const char *p;
1573         int ret;
1574         char *buf_start = buf;
1575         struct property *prop;
1576         bool has_mult, pass;
1577         static const struct printf_spec num_spec = {
1578                 .flags = SMALL,
1579                 .field_width = -1,
1580                 .precision = -1,
1581                 .base = 10,
1582         };
1583
1584         struct printf_spec str_spec = spec;
1585         str_spec.field_width = -1;
1586
1587         if (!IS_ENABLED(CONFIG_OF))
1588                 return string(buf, end, "(!OF)", spec);
1589
1590         if ((unsigned long)dn < PAGE_SIZE)
1591                 return string(buf, end, "(null)", spec);
1592
1593         /* simple case without anything any more format specifiers */
1594         fmt++;
1595         if (fmt[0] == '\0' || strcspn(fmt,"fnpPFcC") > 0)
1596                 fmt = "f";
1597
1598         for (pass = false; strspn(fmt,"fnpPFcC"); fmt++, pass = true) {
1599                 if (pass) {
1600                         if (buf < end)
1601                                 *buf = ':';
1602                         buf++;
1603                 }
1604
1605                 switch (*fmt) {
1606                 case 'f':       /* full_name */
1607                         buf = device_node_gen_full_name(dn, buf, end);
1608                         break;
1609                 case 'n':       /* name */
1610                         buf = string(buf, end, dn->name, str_spec);
1611                         break;
1612                 case 'p':       /* phandle */
1613                         buf = number(buf, end, (unsigned int)dn->phandle, num_spec);
1614                         break;
1615                 case 'P':       /* path-spec */
1616                         p = kbasename(of_node_full_name(dn));
1617                         if (!p[1])
1618                                 p = "/";
1619                         buf = string(buf, end, p, str_spec);
1620                         break;
1621                 case 'F':       /* flags */
1622                         tbuf[0] = of_node_check_flag(dn, OF_DYNAMIC) ? 'D' : '-';
1623                         tbuf[1] = of_node_check_flag(dn, OF_DETACHED) ? 'd' : '-';
1624                         tbuf[2] = of_node_check_flag(dn, OF_POPULATED) ? 'P' : '-';
1625                         tbuf[3] = of_node_check_flag(dn, OF_POPULATED_BUS) ? 'B' : '-';
1626                         tbuf[4] = 0;
1627                         buf = string(buf, end, tbuf, str_spec);
1628                         break;
1629                 case 'c':       /* major compatible string */
1630                         ret = of_property_read_string(dn, "compatible", &p);
1631                         if (!ret)
1632                                 buf = string(buf, end, p, str_spec);
1633                         break;
1634                 case 'C':       /* full compatible string */
1635                         has_mult = false;
1636                         of_property_for_each_string(dn, "compatible", prop, p) {
1637                                 if (has_mult)
1638                                         buf = string(buf, end, ",", str_spec);
1639                                 buf = string(buf, end, "\"", str_spec);
1640                                 buf = string(buf, end, p, str_spec);
1641                                 buf = string(buf, end, "\"", str_spec);
1642
1643                                 has_mult = true;
1644                         }
1645                         break;
1646                 default:
1647                         break;
1648                 }
1649         }
1650
1651         return widen_string(buf, buf - buf_start, end, spec);
1652 }
1653
1654 /* Make pointers available for printing early in the boot sequence. */
1655 static int debug_boot_weak_hash __ro_after_init;
1656
1657 static int __init debug_boot_weak_hash_enable(char *str)
1658 {
1659         debug_boot_weak_hash = 1;
1660         pr_info("debug_boot_weak_hash enabled\n");
1661         return 0;
1662 }
1663 early_param("debug_boot_weak_hash", debug_boot_weak_hash_enable);
1664
1665 static DEFINE_STATIC_KEY_TRUE(not_filled_random_ptr_key);
1666 static siphash_key_t ptr_key __read_mostly;
1667
1668 static void enable_ptr_key_workfn(struct work_struct *work)
1669 {
1670         get_random_bytes(&ptr_key, sizeof(ptr_key));
1671         /* Needs to run from preemptible context */
1672         static_branch_disable(&not_filled_random_ptr_key);
1673 }
1674
1675 static DECLARE_WORK(enable_ptr_key_work, enable_ptr_key_workfn);
1676
1677 static void fill_random_ptr_key(struct random_ready_callback *unused)
1678 {
1679         /* This may be in an interrupt handler. */
1680         queue_work(system_unbound_wq, &enable_ptr_key_work);
1681 }
1682
1683 static struct random_ready_callback random_ready = {
1684         .func = fill_random_ptr_key
1685 };
1686
1687 static int __init initialize_ptr_random(void)
1688 {
1689         int key_size = sizeof(ptr_key);
1690         int ret;
1691
1692         /* Use hw RNG if available. */
1693         if (get_random_bytes_arch(&ptr_key, key_size) == key_size) {
1694                 static_branch_disable(&not_filled_random_ptr_key);
1695                 return 0;
1696         }
1697
1698         ret = add_random_ready_callback(&random_ready);
1699         if (!ret) {
1700                 return 0;
1701         } else if (ret == -EALREADY) {
1702                 /* This is in preemptible context */
1703                 enable_ptr_key_workfn(&enable_ptr_key_work);
1704                 return 0;
1705         }
1706
1707         return ret;
1708 }
1709 early_initcall(initialize_ptr_random);
1710
1711 /* Maps a pointer to a 32 bit unique identifier. */
1712 static char *ptr_to_id(char *buf, char *end, void *ptr, struct printf_spec spec)
1713 {
1714         const char *str = sizeof(ptr) == 8 ? "(____ptrval____)" : "(ptrval)";
1715         unsigned long hashval;
1716
1717         /* When debugging early boot use non-cryptographically secure hash. */
1718         if (unlikely(debug_boot_weak_hash)) {
1719                 hashval = hash_long((unsigned long)ptr, 32);
1720                 return pointer_string(buf, end, (const void *)hashval, spec);
1721         }
1722
1723         if (static_branch_unlikely(&not_filled_random_ptr_key)) {
1724                 spec.field_width = 2 * sizeof(ptr);
1725                 /* string length must be less than default_width */
1726                 return string(buf, end, str, spec);
1727         }
1728
1729 #ifdef CONFIG_64BIT
1730         hashval = (unsigned long)siphash_1u64((u64)ptr, &ptr_key);
1731         /*
1732          * Mask off the first 32 bits, this makes explicit that we have
1733          * modified the address (and 32 bits is plenty for a unique ID).
1734          */
1735         hashval = hashval & 0xffffffff;
1736 #else
1737         hashval = (unsigned long)siphash_1u32((u32)ptr, &ptr_key);
1738 #endif
1739         return pointer_string(buf, end, (const void *)hashval, spec);
1740 }
1741
1742 /*
1743  * Show a '%p' thing.  A kernel extension is that the '%p' is followed
1744  * by an extra set of alphanumeric characters that are extended format
1745  * specifiers.
1746  *
1747  * Please update scripts/checkpatch.pl when adding/removing conversion
1748  * characters.  (Search for "check for vsprintf extension").
1749  *
1750  * Right now we handle:
1751  *
1752  * - 'S' For symbolic direct pointers (or function descriptors) with offset
1753  * - 's' For symbolic direct pointers (or function descriptors) without offset
1754  * - 'F' Same as 'S'
1755  * - 'f' Same as 's'
1756  * - '[FfSs]R' as above with __builtin_extract_return_addr() translation
1757  * - 'B' For backtraced symbolic direct pointers with offset
1758  * - 'R' For decoded struct resource, e.g., [mem 0x0-0x1f 64bit pref]
1759  * - 'r' For raw struct resource, e.g., [mem 0x0-0x1f flags 0x201]
1760  * - 'b[l]' For a bitmap, the number of bits is determined by the field
1761  *       width which must be explicitly specified either as part of the
1762  *       format string '%32b[l]' or through '%*b[l]', [l] selects
1763  *       range-list format instead of hex format
1764  * - 'M' For a 6-byte MAC address, it prints the address in the
1765  *       usual colon-separated hex notation
1766  * - 'm' For a 6-byte MAC address, it prints the hex address without colons
1767  * - 'MF' For a 6-byte MAC FDDI address, it prints the address
1768  *       with a dash-separated hex notation
1769  * - '[mM]R' For a 6-byte MAC address, Reverse order (Bluetooth)
1770  * - 'I' [46] for IPv4/IPv6 addresses printed in the usual way
1771  *       IPv4 uses dot-separated decimal without leading 0's (1.2.3.4)
1772  *       IPv6 uses colon separated network-order 16 bit hex with leading 0's
1773  *       [S][pfs]
1774  *       Generic IPv4/IPv6 address (struct sockaddr *) that falls back to
1775  *       [4] or [6] and is able to print port [p], flowinfo [f], scope [s]
1776  * - 'i' [46] for 'raw' IPv4/IPv6 addresses
1777  *       IPv6 omits the colons (01020304...0f)
1778  *       IPv4 uses dot-separated decimal with leading 0's (010.123.045.006)
1779  *       [S][pfs]
1780  *       Generic IPv4/IPv6 address (struct sockaddr *) that falls back to
1781  *       [4] or [6] and is able to print port [p], flowinfo [f], scope [s]
1782  * - '[Ii][4S][hnbl]' IPv4 addresses in host, network, big or little endian order
1783  * - 'I[6S]c' for IPv6 addresses printed as specified by
1784  *       http://tools.ietf.org/html/rfc5952
1785  * - 'E[achnops]' For an escaped buffer, where rules are defined by combination
1786  *                of the following flags (see string_escape_mem() for the
1787  *                details):
1788  *                  a - ESCAPE_ANY
1789  *                  c - ESCAPE_SPECIAL
1790  *                  h - ESCAPE_HEX
1791  *                  n - ESCAPE_NULL
1792  *                  o - ESCAPE_OCTAL
1793  *                  p - ESCAPE_NP
1794  *                  s - ESCAPE_SPACE
1795  *                By default ESCAPE_ANY_NP is used.
1796  * - 'U' For a 16 byte UUID/GUID, it prints the UUID/GUID in the form
1797  *       "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx"
1798  *       Options for %pU are:
1799  *         b big endian lower case hex (default)
1800  *         B big endian UPPER case hex
1801  *         l little endian lower case hex
1802  *         L little endian UPPER case hex
1803  *           big endian output byte order is:
1804  *             [0][1][2][3]-[4][5]-[6][7]-[8][9]-[10][11][12][13][14][15]
1805  *           little endian output byte order is:
1806  *             [3][2][1][0]-[5][4]-[7][6]-[8][9]-[10][11][12][13][14][15]
1807  * - 'V' For a struct va_format which contains a format string * and va_list *,
1808  *       call vsnprintf(->format, *->va_list).
1809  *       Implements a "recursive vsnprintf".
1810  *       Do not use this feature without some mechanism to verify the
1811  *       correctness of the format string and va_list arguments.
1812  * - 'K' For a kernel pointer that should be hidden from unprivileged users
1813  * - 'NF' For a netdev_features_t
1814  * - 'h[CDN]' For a variable-length buffer, it prints it as a hex string with
1815  *            a certain separator (' ' by default):
1816  *              C colon
1817  *              D dash
1818  *              N no separator
1819  *            The maximum supported length is 64 bytes of the input. Consider
1820  *            to use print_hex_dump() for the larger input.
1821  * - 'a[pd]' For address types [p] phys_addr_t, [d] dma_addr_t and derivatives
1822  *           (default assumed to be phys_addr_t, passed by reference)
1823  * - 'd[234]' For a dentry name (optionally 2-4 last components)
1824  * - 'D[234]' Same as 'd' but for a struct file
1825  * - 'g' For block_device name (gendisk + partition number)
1826  * - 'C' For a clock, it prints the name (Common Clock Framework) or address
1827  *       (legacy clock framework) of the clock
1828  * - 'Cn' For a clock, it prints the name (Common Clock Framework) or address
1829  *        (legacy clock framework) of the clock
1830  * - 'Cr' For a clock, it prints the current rate of the clock
1831  * - 'G' For flags to be printed as a collection of symbolic strings that would
1832  *       construct the specific value. Supported flags given by option:
1833  *       p page flags (see struct page) given as pointer to unsigned long
1834  *       g gfp flags (GFP_* and __GFP_*) given as pointer to gfp_t
1835  *       v vma flags (VM_*) given as pointer to unsigned long
1836  * - 'O' For a kobject based struct. Must be one of the following:
1837  *       - 'OF[fnpPcCF]'  For a device tree object
1838  *                        Without any optional arguments prints the full_name
1839  *                        f device node full_name
1840  *                        n device node name
1841  *                        p device node phandle
1842  *                        P device node path spec (name + @unit)
1843  *                        F device node flags
1844  *                        c major compatible string
1845  *                        C full compatible string
1846  *
1847  * - 'x' For printing the address. Equivalent to "%lx".
1848  *
1849  * ** When making changes please also update:
1850  *      Documentation/core-api/printk-formats.rst
1851  *
1852  * Note: The default behaviour (unadorned %p) is to hash the address,
1853  * rendering it useful as a unique identifier.
1854  */
1855 static noinline_for_stack
1856 char *pointer(const char *fmt, char *buf, char *end, void *ptr,
1857               struct printf_spec spec)
1858 {
1859         const int default_width = 2 * sizeof(void *);
1860
1861         if (!ptr && *fmt != 'K' && *fmt != 'x') {
1862                 /*
1863                  * Print (null) with the same width as a pointer so it makes
1864                  * tabular output look nice.
1865                  */
1866                 if (spec.field_width == -1)
1867                         spec.field_width = default_width;
1868                 return string(buf, end, "(null)", spec);
1869         }
1870
1871         switch (*fmt) {
1872         case 'F':
1873         case 'f':
1874         case 'S':
1875         case 's':
1876                 ptr = dereference_symbol_descriptor(ptr);
1877                 /* Fallthrough */
1878         case 'B':
1879                 return symbol_string(buf, end, ptr, spec, fmt);
1880         case 'R':
1881         case 'r':
1882                 return resource_string(buf, end, ptr, spec, fmt);
1883         case 'h':
1884                 return hex_string(buf, end, ptr, spec, fmt);
1885         case 'b':
1886                 switch (fmt[1]) {
1887                 case 'l':
1888                         return bitmap_list_string(buf, end, ptr, spec, fmt);
1889                 default:
1890                         return bitmap_string(buf, end, ptr, spec, fmt);
1891                 }
1892         case 'M':                       /* Colon separated: 00:01:02:03:04:05 */
1893         case 'm':                       /* Contiguous: 000102030405 */
1894                                         /* [mM]F (FDDI) */
1895                                         /* [mM]R (Reverse order; Bluetooth) */
1896                 return mac_address_string(buf, end, ptr, spec, fmt);
1897         case 'I':                       /* Formatted IP supported
1898                                          * 4:   1.2.3.4
1899                                          * 6:   0001:0203:...:0708
1900                                          * 6c:  1::708 or 1::1.2.3.4
1901                                          */
1902         case 'i':                       /* Contiguous:
1903                                          * 4:   001.002.003.004
1904                                          * 6:   000102...0f
1905                                          */
1906                 switch (fmt[1]) {
1907                 case '6':
1908                         return ip6_addr_string(buf, end, ptr, spec, fmt);
1909                 case '4':
1910                         return ip4_addr_string(buf, end, ptr, spec, fmt);
1911                 case 'S': {
1912                         const union {
1913                                 struct sockaddr         raw;
1914                                 struct sockaddr_in      v4;
1915                                 struct sockaddr_in6     v6;
1916                         } *sa = ptr;
1917
1918                         switch (sa->raw.sa_family) {
1919                         case AF_INET:
1920                                 return ip4_addr_string_sa(buf, end, &sa->v4, spec, fmt);
1921                         case AF_INET6:
1922                                 return ip6_addr_string_sa(buf, end, &sa->v6, spec, fmt);
1923                         default:
1924                                 return string(buf, end, "(invalid address)", spec);
1925                         }}
1926                 }
1927                 break;
1928         case 'E':
1929                 return escaped_string(buf, end, ptr, spec, fmt);
1930         case 'U':
1931                 return uuid_string(buf, end, ptr, spec, fmt);
1932         case 'V':
1933                 {
1934                         va_list va;
1935
1936                         va_copy(va, *((struct va_format *)ptr)->va);
1937                         buf += vsnprintf(buf, end > buf ? end - buf : 0,
1938                                          ((struct va_format *)ptr)->fmt, va);
1939                         va_end(va);
1940                         return buf;
1941                 }
1942         case 'K':
1943                 if (!kptr_restrict)
1944                         break;
1945                 return restricted_pointer(buf, end, ptr, spec);
1946         case 'N':
1947                 return netdev_bits(buf, end, ptr, fmt);
1948         case 'a':
1949                 return address_val(buf, end, ptr, fmt);
1950         case 'd':
1951                 return dentry_name(buf, end, ptr, spec, fmt);
1952         case 'C':
1953                 return clock(buf, end, ptr, spec, fmt);
1954         case 'D':
1955                 return dentry_name(buf, end,
1956                                    ((const struct file *)ptr)->f_path.dentry,
1957                                    spec, fmt);
1958 #ifdef CONFIG_BLOCK
1959         case 'g':
1960                 return bdev_name(buf, end, ptr, spec, fmt);
1961 #endif
1962
1963         case 'G':
1964                 return flags_string(buf, end, ptr, fmt);
1965         case 'O':
1966                 switch (fmt[1]) {
1967                 case 'F':
1968                         return device_node_string(buf, end, ptr, spec, fmt + 1);
1969                 }
1970                 break;
1971         case 'x':
1972                 return pointer_string(buf, end, ptr, spec);
1973         }
1974
1975         /* default is to _not_ leak addresses, hash before printing */
1976         return ptr_to_id(buf, end, ptr, spec);
1977 }
1978
1979 /*
1980  * Helper function to decode printf style format.
1981  * Each call decode a token from the format and return the
1982  * number of characters read (or likely the delta where it wants
1983  * to go on the next call).
1984  * The decoded token is returned through the parameters
1985  *
1986  * 'h', 'l', or 'L' for integer fields
1987  * 'z' support added 23/7/1999 S.H.
1988  * 'z' changed to 'Z' --davidm 1/25/99
1989  * 'Z' changed to 'z' --adobriyan 2017-01-25
1990  * 't' added for ptrdiff_t
1991  *
1992  * @fmt: the format string
1993  * @type of the token returned
1994  * @flags: various flags such as +, -, # tokens..
1995  * @field_width: overwritten width
1996  * @base: base of the number (octal, hex, ...)
1997  * @precision: precision of a number
1998  * @qualifier: qualifier of a number (long, size_t, ...)
1999  */
2000 static noinline_for_stack
2001 int format_decode(const char *fmt, struct printf_spec *spec)
2002 {
2003         const char *start = fmt;
2004         char qualifier;
2005
2006         /* we finished early by reading the field width */
2007         if (spec->type == FORMAT_TYPE_WIDTH) {
2008                 if (spec->field_width < 0) {
2009                         spec->field_width = -spec->field_width;
2010                         spec->flags |= LEFT;
2011                 }
2012                 spec->type = FORMAT_TYPE_NONE;
2013                 goto precision;
2014         }
2015
2016         /* we finished early by reading the precision */
2017         if (spec->type == FORMAT_TYPE_PRECISION) {
2018                 if (spec->precision < 0)
2019                         spec->precision = 0;
2020
2021                 spec->type = FORMAT_TYPE_NONE;
2022                 goto qualifier;
2023         }
2024
2025         /* By default */
2026         spec->type = FORMAT_TYPE_NONE;
2027
2028         for (; *fmt ; ++fmt) {
2029                 if (*fmt == '%')
2030                         break;
2031         }
2032
2033         /* Return the current non-format string */
2034         if (fmt != start || !*fmt)
2035                 return fmt - start;
2036
2037         /* Process flags */
2038         spec->flags = 0;
2039
2040         while (1) { /* this also skips first '%' */
2041                 bool found = true;
2042
2043                 ++fmt;
2044
2045                 switch (*fmt) {
2046                 case '-': spec->flags |= LEFT;    break;
2047                 case '+': spec->flags |= PLUS;    break;
2048                 case ' ': spec->flags |= SPACE;   break;
2049                 case '#': spec->flags |= SPECIAL; break;
2050                 case '0': spec->flags |= ZEROPAD; break;
2051                 default:  found = false;
2052                 }
2053
2054                 if (!found)
2055                         break;
2056         }
2057
2058         /* get field width */
2059         spec->field_width = -1;
2060
2061         if (isdigit(*fmt))
2062                 spec->field_width = skip_atoi(&fmt);
2063         else if (*fmt == '*') {
2064                 /* it's the next argument */
2065                 spec->type = FORMAT_TYPE_WIDTH;
2066                 return ++fmt - start;
2067         }
2068
2069 precision:
2070         /* get the precision */
2071         spec->precision = -1;
2072         if (*fmt == '.') {
2073                 ++fmt;
2074                 if (isdigit(*fmt)) {
2075                         spec->precision = skip_atoi(&fmt);
2076                         if (spec->precision < 0)
2077                                 spec->precision = 0;
2078                 } else if (*fmt == '*') {
2079                         /* it's the next argument */
2080                         spec->type = FORMAT_TYPE_PRECISION;
2081                         return ++fmt - start;
2082                 }
2083         }
2084
2085 qualifier:
2086         /* get the conversion qualifier */
2087         qualifier = 0;
2088         if (*fmt == 'h' || _tolower(*fmt) == 'l' ||
2089             *fmt == 'z' || *fmt == 't') {
2090                 qualifier = *fmt++;
2091                 if (unlikely(qualifier == *fmt)) {
2092                         if (qualifier == 'l') {
2093                                 qualifier = 'L';
2094                                 ++fmt;
2095                         } else if (qualifier == 'h') {
2096                                 qualifier = 'H';
2097                                 ++fmt;
2098                         }
2099                 }
2100         }
2101
2102         /* default base */
2103         spec->base = 10;
2104         switch (*fmt) {
2105         case 'c':
2106                 spec->type = FORMAT_TYPE_CHAR;
2107                 return ++fmt - start;
2108
2109         case 's':
2110                 spec->type = FORMAT_TYPE_STR;
2111                 return ++fmt - start;
2112
2113         case 'p':
2114                 spec->type = FORMAT_TYPE_PTR;
2115                 return ++fmt - start;
2116
2117         case '%':
2118                 spec->type = FORMAT_TYPE_PERCENT_CHAR;
2119                 return ++fmt - start;
2120
2121         /* integer number formats - set up the flags and "break" */
2122         case 'o':
2123                 spec->base = 8;
2124                 break;
2125
2126         case 'x':
2127                 spec->flags |= SMALL;
2128                 /* fall through */
2129
2130         case 'X':
2131                 spec->base = 16;
2132                 break;
2133
2134         case 'd':
2135         case 'i':
2136                 spec->flags |= SIGN;
2137         case 'u':
2138                 break;
2139
2140         case 'n':
2141                 /*
2142                  * Since %n poses a greater security risk than
2143                  * utility, treat it as any other invalid or
2144                  * unsupported format specifier.
2145                  */
2146                 /* Fall-through */
2147
2148         default:
2149                 WARN_ONCE(1, "Please remove unsupported %%%c in format string\n", *fmt);
2150                 spec->type = FORMAT_TYPE_INVALID;
2151                 return fmt - start;
2152         }
2153
2154         if (qualifier == 'L')
2155                 spec->type = FORMAT_TYPE_LONG_LONG;
2156         else if (qualifier == 'l') {
2157                 BUILD_BUG_ON(FORMAT_TYPE_ULONG + SIGN != FORMAT_TYPE_LONG);
2158                 spec->type = FORMAT_TYPE_ULONG + (spec->flags & SIGN);
2159         } else if (qualifier == 'z') {
2160                 spec->type = FORMAT_TYPE_SIZE_T;
2161         } else if (qualifier == 't') {
2162                 spec->type = FORMAT_TYPE_PTRDIFF;
2163         } else if (qualifier == 'H') {
2164                 BUILD_BUG_ON(FORMAT_TYPE_UBYTE + SIGN != FORMAT_TYPE_BYTE);
2165                 spec->type = FORMAT_TYPE_UBYTE + (spec->flags & SIGN);
2166         } else if (qualifier == 'h') {
2167                 BUILD_BUG_ON(FORMAT_TYPE_USHORT + SIGN != FORMAT_TYPE_SHORT);
2168                 spec->type = FORMAT_TYPE_USHORT + (spec->flags & SIGN);
2169         } else {
2170                 BUILD_BUG_ON(FORMAT_TYPE_UINT + SIGN != FORMAT_TYPE_INT);
2171                 spec->type = FORMAT_TYPE_UINT + (spec->flags & SIGN);
2172         }
2173
2174         return ++fmt - start;
2175 }
2176
2177 static void
2178 set_field_width(struct printf_spec *spec, int width)
2179 {
2180         spec->field_width = width;
2181         if (WARN_ONCE(spec->field_width != width, "field width %d too large", width)) {
2182                 spec->field_width = clamp(width, -FIELD_WIDTH_MAX, FIELD_WIDTH_MAX);
2183         }
2184 }
2185
2186 static void
2187 set_precision(struct printf_spec *spec, int prec)
2188 {
2189         spec->precision = prec;
2190         if (WARN_ONCE(spec->precision != prec, "precision %d too large", prec)) {
2191                 spec->precision = clamp(prec, 0, PRECISION_MAX);
2192         }
2193 }
2194
2195 /**
2196  * vsnprintf - Format a string and place it in a buffer
2197  * @buf: The buffer to place the result into
2198  * @size: The size of the buffer, including the trailing null space
2199  * @fmt: The format string to use
2200  * @args: Arguments for the format string
2201  *
2202  * This function generally follows C99 vsnprintf, but has some
2203  * extensions and a few limitations:
2204  *
2205  *  - ``%n`` is unsupported
2206  *  - ``%p*`` is handled by pointer()
2207  *
2208  * See pointer() or Documentation/core-api/printk-formats.rst for more
2209  * extensive description.
2210  *
2211  * **Please update the documentation in both places when making changes**
2212  *
2213  * The return value is the number of characters which would
2214  * be generated for the given input, excluding the trailing
2215  * '\0', as per ISO C99. If you want to have the exact
2216  * number of characters written into @buf as return value
2217  * (not including the trailing '\0'), use vscnprintf(). If the
2218  * return is greater than or equal to @size, the resulting
2219  * string is truncated.
2220  *
2221  * If you're not already dealing with a va_list consider using snprintf().
2222  */
2223 int vsnprintf(char *buf, size_t size, const char *fmt, va_list args)
2224 {
2225         unsigned long long num;
2226         char *str, *end;
2227         struct printf_spec spec = {0};
2228
2229         /* Reject out-of-range values early.  Large positive sizes are
2230            used for unknown buffer sizes. */
2231         if (WARN_ON_ONCE(size > INT_MAX))
2232                 return 0;
2233
2234         str = buf;
2235         end = buf + size;
2236
2237         /* Make sure end is always >= buf */
2238         if (end < buf) {
2239                 end = ((void *)-1);
2240                 size = end - buf;
2241         }
2242
2243         while (*fmt) {
2244                 const char *old_fmt = fmt;
2245                 int read = format_decode(fmt, &spec);
2246
2247                 fmt += read;
2248
2249                 switch (spec.type) {
2250                 case FORMAT_TYPE_NONE: {
2251                         int copy = read;
2252                         if (str < end) {
2253                                 if (copy > end - str)
2254                                         copy = end - str;
2255                                 memcpy(str, old_fmt, copy);
2256                         }
2257                         str += read;
2258                         break;
2259                 }
2260
2261                 case FORMAT_TYPE_WIDTH:
2262                         set_field_width(&spec, va_arg(args, int));
2263                         break;
2264
2265                 case FORMAT_TYPE_PRECISION:
2266                         set_precision(&spec, va_arg(args, int));
2267                         break;
2268
2269                 case FORMAT_TYPE_CHAR: {
2270                         char c;
2271
2272                         if (!(spec.flags & LEFT)) {
2273                                 while (--spec.field_width > 0) {
2274                                         if (str < end)
2275                                                 *str = ' ';
2276                                         ++str;
2277
2278                                 }
2279                         }
2280                         c = (unsigned char) va_arg(args, int);
2281                         if (str < end)
2282                                 *str = c;
2283                         ++str;
2284                         while (--spec.field_width > 0) {
2285                                 if (str < end)
2286                                         *str = ' ';
2287                                 ++str;
2288                         }
2289                         break;
2290                 }
2291
2292                 case FORMAT_TYPE_STR:
2293                         str = string(str, end, va_arg(args, char *), spec);
2294                         break;
2295
2296                 case FORMAT_TYPE_PTR:
2297                         str = pointer(fmt, str, end, va_arg(args, void *),
2298                                       spec);
2299                         while (isalnum(*fmt))
2300                                 fmt++;
2301                         break;
2302
2303                 case FORMAT_TYPE_PERCENT_CHAR:
2304                         if (str < end)
2305                                 *str = '%';
2306                         ++str;
2307                         break;
2308
2309                 case FORMAT_TYPE_INVALID:
2310                         /*
2311                          * Presumably the arguments passed gcc's type
2312                          * checking, but there is no safe or sane way
2313                          * for us to continue parsing the format and
2314                          * fetching from the va_list; the remaining
2315                          * specifiers and arguments would be out of
2316                          * sync.
2317                          */
2318                         goto out;
2319
2320                 default:
2321                         switch (spec.type) {
2322                         case FORMAT_TYPE_LONG_LONG:
2323                                 num = va_arg(args, long long);
2324                                 break;
2325                         case FORMAT_TYPE_ULONG:
2326                                 num = va_arg(args, unsigned long);
2327                                 break;
2328                         case FORMAT_TYPE_LONG:
2329                                 num = va_arg(args, long);
2330                                 break;
2331                         case FORMAT_TYPE_SIZE_T:
2332                                 if (spec.flags & SIGN)
2333                                         num = va_arg(args, ssize_t);
2334                                 else
2335                                         num = va_arg(args, size_t);
2336                                 break;
2337                         case FORMAT_TYPE_PTRDIFF:
2338                                 num = va_arg(args, ptrdiff_t);
2339                                 break;
2340                         case FORMAT_TYPE_UBYTE:
2341                                 num = (unsigned char) va_arg(args, int);
2342                                 break;
2343                         case FORMAT_TYPE_BYTE:
2344                                 num = (signed char) va_arg(args, int);
2345                                 break;
2346                         case FORMAT_TYPE_USHORT:
2347                                 num = (unsigned short) va_arg(args, int);
2348                                 break;
2349                         case FORMAT_TYPE_SHORT:
2350                                 num = (short) va_arg(args, int);
2351                                 break;
2352                         case FORMAT_TYPE_INT:
2353                                 num = (int) va_arg(args, int);
2354                                 break;
2355                         default:
2356                                 num = va_arg(args, unsigned int);
2357                         }
2358
2359                         str = number(str, end, num, spec);
2360                 }
2361         }
2362
2363 out:
2364         if (size > 0) {
2365                 if (str < end)
2366                         *str = '\0';
2367                 else
2368                         end[-1] = '\0';
2369         }
2370
2371         /* the trailing null byte doesn't count towards the total */
2372         return str-buf;
2373
2374 }
2375 EXPORT_SYMBOL(vsnprintf);
2376
2377 /**
2378  * vscnprintf - Format a string and place it in a buffer
2379  * @buf: The buffer to place the result into
2380  * @size: The size of the buffer, including the trailing null space
2381  * @fmt: The format string to use
2382  * @args: Arguments for the format string
2383  *
2384  * The return value is the number of characters which have been written into
2385  * the @buf not including the trailing '\0'. If @size is == 0 the function
2386  * returns 0.
2387  *
2388  * If you're not already dealing with a va_list consider using scnprintf().
2389  *
2390  * See the vsnprintf() documentation for format string extensions over C99.
2391  */
2392 int vscnprintf(char *buf, size_t size, const char *fmt, va_list args)
2393 {
2394         int i;
2395
2396         i = vsnprintf(buf, size, fmt, args);
2397
2398         if (likely(i < size))
2399                 return i;
2400         if (size != 0)
2401                 return size - 1;
2402         return 0;
2403 }
2404 EXPORT_SYMBOL(vscnprintf);
2405
2406 /**
2407  * snprintf - Format a string and place it in a buffer
2408  * @buf: The buffer to place the result into
2409  * @size: The size of the buffer, including the trailing null space
2410  * @fmt: The format string to use
2411  * @...: Arguments for the format string
2412  *
2413  * The return value is the number of characters which would be
2414  * generated for the given input, excluding the trailing null,
2415  * as per ISO C99.  If the return is greater than or equal to
2416  * @size, the resulting string is truncated.
2417  *
2418  * See the vsnprintf() documentation for format string extensions over C99.
2419  */
2420 int snprintf(char *buf, size_t size, const char *fmt, ...)
2421 {
2422         va_list args;
2423         int i;
2424
2425         va_start(args, fmt);
2426         i = vsnprintf(buf, size, fmt, args);
2427         va_end(args);
2428
2429         return i;
2430 }
2431 EXPORT_SYMBOL(snprintf);
2432
2433 /**
2434  * scnprintf - Format a string and place it in a buffer
2435  * @buf: The buffer to place the result into
2436  * @size: The size of the buffer, including the trailing null space
2437  * @fmt: The format string to use
2438  * @...: Arguments for the format string
2439  *
2440  * The return value is the number of characters written into @buf not including
2441  * the trailing '\0'. If @size is == 0 the function returns 0.
2442  */
2443
2444 int scnprintf(char *buf, size_t size, const char *fmt, ...)
2445 {
2446         va_list args;
2447         int i;
2448
2449         va_start(args, fmt);
2450         i = vscnprintf(buf, size, fmt, args);
2451         va_end(args);
2452
2453         return i;
2454 }
2455 EXPORT_SYMBOL(scnprintf);
2456
2457 /**
2458  * vsprintf - Format a string and place it in a buffer
2459  * @buf: The buffer to place the result into
2460  * @fmt: The format string to use
2461  * @args: Arguments for the format string
2462  *
2463  * The function returns the number of characters written
2464  * into @buf. Use vsnprintf() or vscnprintf() in order to avoid
2465  * buffer overflows.
2466  *
2467  * If you're not already dealing with a va_list consider using sprintf().
2468  *
2469  * See the vsnprintf() documentation for format string extensions over C99.
2470  */
2471 int vsprintf(char *buf, const char *fmt, va_list args)
2472 {
2473         return vsnprintf(buf, INT_MAX, fmt, args);
2474 }
2475 EXPORT_SYMBOL(vsprintf);
2476
2477 /**
2478  * sprintf - Format a string and place it in a buffer
2479  * @buf: The buffer to place the result into
2480  * @fmt: The format string to use
2481  * @...: Arguments for the format string
2482  *
2483  * The function returns the number of characters written
2484  * into @buf. Use snprintf() or scnprintf() in order to avoid
2485  * buffer overflows.
2486  *
2487  * See the vsnprintf() documentation for format string extensions over C99.
2488  */
2489 int sprintf(char *buf, const char *fmt, ...)
2490 {
2491         va_list args;
2492         int i;
2493
2494         va_start(args, fmt);
2495         i = vsnprintf(buf, INT_MAX, fmt, args);
2496         va_end(args);
2497
2498         return i;
2499 }
2500 EXPORT_SYMBOL(sprintf);
2501
2502 #ifdef CONFIG_BINARY_PRINTF
2503 /*
2504  * bprintf service:
2505  * vbin_printf() - VA arguments to binary data
2506  * bstr_printf() - Binary data to text string
2507  */
2508
2509 /**
2510  * vbin_printf - Parse a format string and place args' binary value in a buffer
2511  * @bin_buf: The buffer to place args' binary value
2512  * @size: The size of the buffer(by words(32bits), not characters)
2513  * @fmt: The format string to use
2514  * @args: Arguments for the format string
2515  *
2516  * The format follows C99 vsnprintf, except %n is ignored, and its argument
2517  * is skipped.
2518  *
2519  * The return value is the number of words(32bits) which would be generated for
2520  * the given input.
2521  *
2522  * NOTE:
2523  * If the return value is greater than @size, the resulting bin_buf is NOT
2524  * valid for bstr_printf().
2525  */
2526 int vbin_printf(u32 *bin_buf, size_t size, const char *fmt, va_list args)
2527 {
2528         struct printf_spec spec = {0};
2529         char *str, *end;
2530         int width;
2531
2532         str = (char *)bin_buf;
2533         end = (char *)(bin_buf + size);
2534
2535 #define save_arg(type)                                                  \
2536 ({                                                                      \
2537         unsigned long long value;                                       \
2538         if (sizeof(type) == 8) {                                        \
2539                 unsigned long long val8;                                \
2540                 str = PTR_ALIGN(str, sizeof(u32));                      \
2541                 val8 = va_arg(args, unsigned long long);                \
2542                 if (str + sizeof(type) <= end) {                        \
2543                         *(u32 *)str = *(u32 *)&val8;                    \
2544                         *(u32 *)(str + 4) = *((u32 *)&val8 + 1);        \
2545                 }                                                       \
2546                 value = val8;                                           \
2547         } else {                                                        \
2548                 unsigned int val4;                                      \
2549                 str = PTR_ALIGN(str, sizeof(type));                     \
2550                 val4 = va_arg(args, int);                               \
2551                 if (str + sizeof(type) <= end)                          \
2552                         *(typeof(type) *)str = (type)(long)val4;        \
2553                 value = (unsigned long long)val4;                       \
2554         }                                                               \
2555         str += sizeof(type);                                            \
2556         value;                                                          \
2557 })
2558
2559         while (*fmt) {
2560                 int read = format_decode(fmt, &spec);
2561
2562                 fmt += read;
2563
2564                 switch (spec.type) {
2565                 case FORMAT_TYPE_NONE:
2566                 case FORMAT_TYPE_PERCENT_CHAR:
2567                         break;
2568                 case FORMAT_TYPE_INVALID:
2569                         goto out;
2570
2571                 case FORMAT_TYPE_WIDTH:
2572                 case FORMAT_TYPE_PRECISION:
2573                         width = (int)save_arg(int);
2574                         /* Pointers may require the width */
2575                         if (*fmt == 'p')
2576                                 set_field_width(&spec, width);
2577                         break;
2578
2579                 case FORMAT_TYPE_CHAR:
2580                         save_arg(char);
2581                         break;
2582
2583                 case FORMAT_TYPE_STR: {
2584                         const char *save_str = va_arg(args, char *);
2585                         size_t len;
2586
2587                         if ((unsigned long)save_str > (unsigned long)-PAGE_SIZE
2588                                         || (unsigned long)save_str < PAGE_SIZE)
2589                                 save_str = "(null)";
2590                         len = strlen(save_str) + 1;
2591                         if (str + len < end)
2592                                 memcpy(str, save_str, len);
2593                         str += len;
2594                         break;
2595                 }
2596
2597                 case FORMAT_TYPE_PTR:
2598                         /* Dereferenced pointers must be done now */
2599                         switch (*fmt) {
2600                         /* Dereference of functions is still OK */
2601                         case 'S':
2602                         case 's':
2603                         case 'F':
2604                         case 'f':
2605                         case 'x':
2606                         case 'K':
2607                                 save_arg(void *);
2608                                 break;
2609                         default:
2610                                 if (!isalnum(*fmt)) {
2611                                         save_arg(void *);
2612                                         break;
2613                                 }
2614                                 str = pointer(fmt, str, end, va_arg(args, void *),
2615                                               spec);
2616                                 if (str + 1 < end)
2617                                         *str++ = '\0';
2618                                 else
2619                                         end[-1] = '\0'; /* Must be nul terminated */
2620                         }
2621                         /* skip all alphanumeric pointer suffixes */
2622                         while (isalnum(*fmt))
2623                                 fmt++;
2624                         break;
2625
2626                 default:
2627                         switch (spec.type) {
2628
2629                         case FORMAT_TYPE_LONG_LONG:
2630                                 save_arg(long long);
2631                                 break;
2632                         case FORMAT_TYPE_ULONG:
2633                         case FORMAT_TYPE_LONG:
2634                                 save_arg(unsigned long);
2635                                 break;
2636                         case FORMAT_TYPE_SIZE_T:
2637                                 save_arg(size_t);
2638                                 break;
2639                         case FORMAT_TYPE_PTRDIFF:
2640                                 save_arg(ptrdiff_t);
2641                                 break;
2642                         case FORMAT_TYPE_UBYTE:
2643                         case FORMAT_TYPE_BYTE:
2644                                 save_arg(char);
2645                                 break;
2646                         case FORMAT_TYPE_USHORT:
2647                         case FORMAT_TYPE_SHORT:
2648                                 save_arg(short);
2649                                 break;
2650                         default:
2651                                 save_arg(int);
2652                         }
2653                 }
2654         }
2655
2656 out:
2657         return (u32 *)(PTR_ALIGN(str, sizeof(u32))) - bin_buf;
2658 #undef save_arg
2659 }
2660 EXPORT_SYMBOL_GPL(vbin_printf);
2661
2662 /**
2663  * bstr_printf - Format a string from binary arguments and place it in a buffer
2664  * @buf: The buffer to place the result into
2665  * @size: The size of the buffer, including the trailing null space
2666  * @fmt: The format string to use
2667  * @bin_buf: Binary arguments for the format string
2668  *
2669  * This function like C99 vsnprintf, but the difference is that vsnprintf gets
2670  * arguments from stack, and bstr_printf gets arguments from @bin_buf which is
2671  * a binary buffer that generated by vbin_printf.
2672  *
2673  * The format follows C99 vsnprintf, but has some extensions:
2674  *  see vsnprintf comment for details.
2675  *
2676  * The return value is the number of characters which would
2677  * be generated for the given input, excluding the trailing
2678  * '\0', as per ISO C99. If you want to have the exact
2679  * number of characters written into @buf as return value
2680  * (not including the trailing '\0'), use vscnprintf(). If the
2681  * return is greater than or equal to @size, the resulting
2682  * string is truncated.
2683  */
2684 int bstr_printf(char *buf, size_t size, const char *fmt, const u32 *bin_buf)
2685 {
2686         struct printf_spec spec = {0};
2687         char *str, *end;
2688         const char *args = (const char *)bin_buf;
2689
2690         if (WARN_ON_ONCE(size > INT_MAX))
2691                 return 0;
2692
2693         str = buf;
2694         end = buf + size;
2695
2696 #define get_arg(type)                                                   \
2697 ({                                                                      \
2698         typeof(type) value;                                             \
2699         if (sizeof(type) == 8) {                                        \
2700                 args = PTR_ALIGN(args, sizeof(u32));                    \
2701                 *(u32 *)&value = *(u32 *)args;                          \
2702                 *((u32 *)&value + 1) = *(u32 *)(args + 4);              \
2703         } else {                                                        \
2704                 args = PTR_ALIGN(args, sizeof(type));                   \
2705                 value = *(typeof(type) *)args;                          \
2706         }                                                               \
2707         args += sizeof(type);                                           \
2708         value;                                                          \
2709 })
2710
2711         /* Make sure end is always >= buf */
2712         if (end < buf) {
2713                 end = ((void *)-1);
2714                 size = end - buf;
2715         }
2716
2717         while (*fmt) {
2718                 const char *old_fmt = fmt;
2719                 int read = format_decode(fmt, &spec);
2720
2721                 fmt += read;
2722
2723                 switch (spec.type) {
2724                 case FORMAT_TYPE_NONE: {
2725                         int copy = read;
2726                         if (str < end) {
2727                                 if (copy > end - str)
2728                                         copy = end - str;
2729                                 memcpy(str, old_fmt, copy);
2730                         }
2731                         str += read;
2732                         break;
2733                 }
2734
2735                 case FORMAT_TYPE_WIDTH:
2736                         set_field_width(&spec, get_arg(int));
2737                         break;
2738
2739                 case FORMAT_TYPE_PRECISION:
2740                         set_precision(&spec, get_arg(int));
2741                         break;
2742
2743                 case FORMAT_TYPE_CHAR: {
2744                         char c;
2745
2746                         if (!(spec.flags & LEFT)) {
2747                                 while (--spec.field_width > 0) {
2748                                         if (str < end)
2749                                                 *str = ' ';
2750                                         ++str;
2751                                 }
2752                         }
2753                         c = (unsigned char) get_arg(char);
2754                         if (str < end)
2755                                 *str = c;
2756                         ++str;
2757                         while (--spec.field_width > 0) {
2758                                 if (str < end)
2759                                         *str = ' ';
2760                                 ++str;
2761                         }
2762                         break;
2763                 }
2764
2765                 case FORMAT_TYPE_STR: {
2766                         const char *str_arg = args;
2767                         args += strlen(str_arg) + 1;
2768                         str = string(str, end, (char *)str_arg, spec);
2769                         break;
2770                 }
2771
2772                 case FORMAT_TYPE_PTR: {
2773                         bool process = false;
2774                         int copy, len;
2775                         /* Non function dereferences were already done */
2776                         switch (*fmt) {
2777                         case 'S':
2778                         case 's':
2779                         case 'F':
2780                         case 'f':
2781                         case 'x':
2782                         case 'K':
2783                                 process = true;
2784                                 break;
2785                         default:
2786                                 if (!isalnum(*fmt)) {
2787                                         process = true;
2788                                         break;
2789                                 }
2790                                 /* Pointer dereference was already processed */
2791                                 if (str < end) {
2792                                         len = copy = strlen(args);
2793                                         if (copy > end - str)
2794                                                 copy = end - str;
2795                                         memcpy(str, args, copy);
2796                                         str += len;
2797                                         args += len;
2798                                 }
2799                         }
2800                         if (process)
2801                                 str = pointer(fmt, str, end, get_arg(void *), spec);
2802
2803                         while (isalnum(*fmt))
2804                                 fmt++;
2805                         break;
2806                 }
2807
2808                 case FORMAT_TYPE_PERCENT_CHAR:
2809                         if (str < end)
2810                                 *str = '%';
2811                         ++str;
2812                         break;
2813
2814                 case FORMAT_TYPE_INVALID:
2815                         goto out;
2816
2817                 default: {
2818                         unsigned long long num;
2819
2820                         switch (spec.type) {
2821
2822                         case FORMAT_TYPE_LONG_LONG:
2823                                 num = get_arg(long long);
2824                                 break;
2825                         case FORMAT_TYPE_ULONG:
2826                         case FORMAT_TYPE_LONG:
2827                                 num = get_arg(unsigned long);
2828                                 break;
2829                         case FORMAT_TYPE_SIZE_T:
2830                                 num = get_arg(size_t);
2831                                 break;
2832                         case FORMAT_TYPE_PTRDIFF:
2833                                 num = get_arg(ptrdiff_t);
2834                                 break;
2835                         case FORMAT_TYPE_UBYTE:
2836                                 num = get_arg(unsigned char);
2837                                 break;
2838                         case FORMAT_TYPE_BYTE:
2839                                 num = get_arg(signed char);
2840                                 break;
2841                         case FORMAT_TYPE_USHORT:
2842                                 num = get_arg(unsigned short);
2843                                 break;
2844                         case FORMAT_TYPE_SHORT:
2845                                 num = get_arg(short);
2846                                 break;
2847                         case FORMAT_TYPE_UINT:
2848                                 num = get_arg(unsigned int);
2849                                 break;
2850                         default:
2851                                 num = get_arg(int);
2852                         }
2853
2854                         str = number(str, end, num, spec);
2855                 } /* default: */
2856                 } /* switch(spec.type) */
2857         } /* while(*fmt) */
2858
2859 out:
2860         if (size > 0) {
2861                 if (str < end)
2862                         *str = '\0';
2863                 else
2864                         end[-1] = '\0';
2865         }
2866
2867 #undef get_arg
2868
2869         /* the trailing null byte doesn't count towards the total */
2870         return str - buf;
2871 }
2872 EXPORT_SYMBOL_GPL(bstr_printf);
2873
2874 /**
2875  * bprintf - Parse a format string and place args' binary value in a buffer
2876  * @bin_buf: The buffer to place args' binary value
2877  * @size: The size of the buffer(by words(32bits), not characters)
2878  * @fmt: The format string to use
2879  * @...: Arguments for the format string
2880  *
2881  * The function returns the number of words(u32) written
2882  * into @bin_buf.
2883  */
2884 int bprintf(u32 *bin_buf, size_t size, const char *fmt, ...)
2885 {
2886         va_list args;
2887         int ret;
2888
2889         va_start(args, fmt);
2890         ret = vbin_printf(bin_buf, size, fmt, args);
2891         va_end(args);
2892
2893         return ret;
2894 }
2895 EXPORT_SYMBOL_GPL(bprintf);
2896
2897 #endif /* CONFIG_BINARY_PRINTF */
2898
2899 /**
2900  * vsscanf - Unformat a buffer into a list of arguments
2901  * @buf:        input buffer
2902  * @fmt:        format of buffer
2903  * @args:       arguments
2904  */
2905 int vsscanf(const char *buf, const char *fmt, va_list args)
2906 {
2907         const char *str = buf;
2908         char *next;
2909         char digit;
2910         int num = 0;
2911         u8 qualifier;
2912         unsigned int base;
2913         union {
2914                 long long s;
2915                 unsigned long long u;
2916         } val;
2917         s16 field_width;
2918         bool is_sign;
2919
2920         while (*fmt) {
2921                 /* skip any white space in format */
2922                 /* white space in format matchs any amount of
2923                  * white space, including none, in the input.
2924                  */
2925                 if (isspace(*fmt)) {
2926                         fmt = skip_spaces(++fmt);
2927                         str = skip_spaces(str);
2928                 }
2929
2930                 /* anything that is not a conversion must match exactly */
2931                 if (*fmt != '%' && *fmt) {
2932                         if (*fmt++ != *str++)
2933                                 break;
2934                         continue;
2935                 }
2936
2937                 if (!*fmt)
2938                         break;
2939                 ++fmt;
2940
2941                 /* skip this conversion.
2942                  * advance both strings to next white space
2943                  */
2944                 if (*fmt == '*') {
2945                         if (!*str)
2946                                 break;
2947                         while (!isspace(*fmt) && *fmt != '%' && *fmt) {
2948                                 /* '%*[' not yet supported, invalid format */
2949                                 if (*fmt == '[')
2950                                         return num;
2951                                 fmt++;
2952                         }
2953                         while (!isspace(*str) && *str)
2954                                 str++;
2955                         continue;
2956                 }
2957
2958                 /* get field width */
2959                 field_width = -1;
2960                 if (isdigit(*fmt)) {
2961                         field_width = skip_atoi(&fmt);
2962                         if (field_width <= 0)
2963                                 break;
2964                 }
2965
2966                 /* get conversion qualifier */
2967                 qualifier = -1;
2968                 if (*fmt == 'h' || _tolower(*fmt) == 'l' ||
2969                     *fmt == 'z') {
2970                         qualifier = *fmt++;
2971                         if (unlikely(qualifier == *fmt)) {
2972                                 if (qualifier == 'h') {
2973                                         qualifier = 'H';
2974                                         fmt++;
2975                                 } else if (qualifier == 'l') {
2976                                         qualifier = 'L';
2977                                         fmt++;
2978                                 }
2979                         }
2980                 }
2981
2982                 if (!*fmt)
2983                         break;
2984
2985                 if (*fmt == 'n') {
2986                         /* return number of characters read so far */
2987                         *va_arg(args, int *) = str - buf;
2988                         ++fmt;
2989                         continue;
2990                 }
2991
2992                 if (!*str)
2993                         break;
2994
2995                 base = 10;
2996                 is_sign = false;
2997
2998                 switch (*fmt++) {
2999                 case 'c':
3000                 {
3001                         char *s = (char *)va_arg(args, char*);
3002                         if (field_width == -1)
3003                                 field_width = 1;
3004                         do {
3005                                 *s++ = *str++;
3006                         } while (--field_width > 0 && *str);
3007                         num++;
3008                 }
3009                 continue;
3010                 case 's':
3011                 {
3012                         char *s = (char *)va_arg(args, char *);
3013                         if (field_width == -1)
3014                                 field_width = SHRT_MAX;
3015                         /* first, skip leading white space in buffer */
3016                         str = skip_spaces(str);
3017
3018                         /* now copy until next white space */
3019                         while (*str && !isspace(*str) && field_width--)
3020                                 *s++ = *str++;
3021                         *s = '\0';
3022                         num++;
3023                 }
3024                 continue;
3025                 /*
3026                  * Warning: This implementation of the '[' conversion specifier
3027                  * deviates from its glibc counterpart in the following ways:
3028                  * (1) It does NOT support ranges i.e. '-' is NOT a special
3029                  *     character
3030                  * (2) It cannot match the closing bracket ']' itself
3031                  * (3) A field width is required
3032                  * (4) '%*[' (discard matching input) is currently not supported
3033                  *
3034                  * Example usage:
3035                  * ret = sscanf("00:0a:95","%2[^:]:%2[^:]:%2[^:]",
3036                  *              buf1, buf2, buf3);
3037                  * if (ret < 3)
3038                  *    // etc..
3039                  */
3040                 case '[':
3041                 {
3042                         char *s = (char *)va_arg(args, char *);
3043                         DECLARE_BITMAP(set, 256) = {0};
3044                         unsigned int len = 0;
3045                         bool negate = (*fmt == '^');
3046
3047                         /* field width is required */
3048                         if (field_width == -1)
3049                                 return num;
3050
3051                         if (negate)
3052                                 ++fmt;
3053
3054                         for ( ; *fmt && *fmt != ']'; ++fmt, ++len)
3055                                 set_bit((u8)*fmt, set);
3056
3057                         /* no ']' or no character set found */
3058                         if (!*fmt || !len)
3059                                 return num;
3060                         ++fmt;
3061
3062                         if (negate) {
3063                                 bitmap_complement(set, set, 256);
3064                                 /* exclude null '\0' byte */
3065                                 clear_bit(0, set);
3066                         }
3067
3068                         /* match must be non-empty */
3069                         if (!test_bit((u8)*str, set))
3070                                 return num;
3071
3072                         while (test_bit((u8)*str, set) && field_width--)
3073                                 *s++ = *str++;
3074                         *s = '\0';
3075                         ++num;
3076                 }
3077                 continue;
3078                 case 'o':
3079                         base = 8;
3080                         break;
3081                 case 'x':
3082                 case 'X':
3083                         base = 16;
3084                         break;
3085                 case 'i':
3086                         base = 0;
3087                         /* fall through */
3088                 case 'd':
3089                         is_sign = true;
3090                         /* fall through */
3091                 case 'u':
3092                         break;
3093                 case '%':
3094                         /* looking for '%' in str */
3095                         if (*str++ != '%')
3096                                 return num;
3097                         continue;
3098                 default:
3099                         /* invalid format; stop here */
3100                         return num;
3101                 }
3102
3103                 /* have some sort of integer conversion.
3104                  * first, skip white space in buffer.
3105                  */
3106                 str = skip_spaces(str);
3107
3108                 digit = *str;
3109                 if (is_sign && digit == '-')
3110                         digit = *(str + 1);
3111
3112                 if (!digit
3113                     || (base == 16 && !isxdigit(digit))
3114                     || (base == 10 && !isdigit(digit))
3115                     || (base == 8 && (!isdigit(digit) || digit > '7'))
3116                     || (base == 0 && !isdigit(digit)))
3117                         break;
3118
3119                 if (is_sign)
3120                         val.s = qualifier != 'L' ?
3121                                 simple_strtol(str, &next, base) :
3122                                 simple_strtoll(str, &next, base);
3123                 else
3124                         val.u = qualifier != 'L' ?
3125                                 simple_strtoul(str, &next, base) :
3126                                 simple_strtoull(str, &next, base);
3127
3128                 if (field_width > 0 && next - str > field_width) {
3129                         if (base == 0)
3130                                 _parse_integer_fixup_radix(str, &base);
3131                         while (next - str > field_width) {
3132                                 if (is_sign)
3133                                         val.s = div_s64(val.s, base);
3134                                 else
3135                                         val.u = div_u64(val.u, base);
3136                                 --next;
3137                         }
3138                 }
3139
3140                 switch (qualifier) {
3141                 case 'H':       /* that's 'hh' in format */
3142                         if (is_sign)
3143                                 *va_arg(args, signed char *) = val.s;
3144                         else
3145                                 *va_arg(args, unsigned char *) = val.u;
3146                         break;
3147                 case 'h':
3148                         if (is_sign)
3149                                 *va_arg(args, short *) = val.s;
3150                         else
3151                                 *va_arg(args, unsigned short *) = val.u;
3152                         break;
3153                 case 'l':
3154                         if (is_sign)
3155                                 *va_arg(args, long *) = val.s;
3156                         else
3157                                 *va_arg(args, unsigned long *) = val.u;
3158                         break;
3159                 case 'L':
3160                         if (is_sign)
3161                                 *va_arg(args, long long *) = val.s;
3162                         else
3163                                 *va_arg(args, unsigned long long *) = val.u;
3164                         break;
3165                 case 'z':
3166                         *va_arg(args, size_t *) = val.u;
3167                         break;
3168                 default:
3169                         if (is_sign)
3170                                 *va_arg(args, int *) = val.s;
3171                         else
3172                                 *va_arg(args, unsigned int *) = val.u;
3173                         break;
3174                 }
3175                 num++;
3176
3177                 if (!next)
3178                         break;
3179                 str = next;
3180         }
3181
3182         return num;
3183 }
3184 EXPORT_SYMBOL(vsscanf);
3185
3186 /**
3187  * sscanf - Unformat a buffer into a list of arguments
3188  * @buf:        input buffer
3189  * @fmt:        formatting of buffer
3190  * @...:        resulting arguments
3191  */
3192 int sscanf(const char *buf, const char *fmt, ...)
3193 {
3194         va_list args;
3195         int i;
3196
3197         va_start(args, fmt);
3198         i = vsscanf(buf, fmt, args);
3199         va_end(args);
3200
3201         return i;
3202 }
3203 EXPORT_SYMBOL(sscanf);