lib/vsprintf.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  *  linux/lib/vsprintf.c
   4  *
   5  *  Copyright (C) 1991, 1992  Linus Torvalds
   6  */
   7
   8 /* vsprintf.c -- Lars Wirzenius & Linus Torvalds. */
   9 /*
  10  * Wirzenius wrote this portably, Torvalds fucked it up :-)
  11  */
  12
  13 /*
  14  * Fri Jul 13 2001 Crutcher Dunnavant <crutcher+kernel@datastacks.com>
  15  * - changed to provide snprintf and vsnprintf functions
  16  * So Feb  1 16:51:32 CET 2004 Juergen Quade <quade@hsnr.de>
  17  * - scnprintf and vscnprintf
  18  */
  19
  20 #include <stdarg.h>
  21 #include <linux/build_bug.h>
  22 #include <linux/clk.h>
  23 #include <linux/clk-provider.h>
  24 #include <linux/module.h>       /* for KSYM_SYMBOL_LEN */
  25 #include <linux/types.h>
  26 #include <linux/string.h>
  27 #include <linux/ctype.h>
  28 #include <linux/kernel.h>
  29 #include <linux/kallsyms.h>
  30 #include <linux/math64.h>
  31 #include <linux/uaccess.h>
  32 #include <linux/ioport.h>
  33 #include <linux/dcache.h>
  34 #include <linux/cred.h>
  35 #include <linux/rtc.h>
  36 #include <linux/uuid.h>
  37 #include <linux/of.h>
  38 #include <net/addrconf.h>
  39 #include <linux/siphash.h>
  40 #include <linux/compiler.h>
  41 #ifdef CONFIG_BLOCK
  42 #include <linux/blkdev.h>
  43 #endif
  44
  45 #include "../mm/internal.h"     /* For the trace_print_flags arrays */
  46
  47 #include <asm/page.h>           /* for PAGE_SIZE */
  48 #include <asm/byteorder.h>      /* cpu_to_le16 */
  49
  50 #include <linux/string_helpers.h>
  51 #include "kstrtox.h"
  52
  53 /**
  54  * simple_strtoull - convert a string to an unsigned long long
  55  * @cp: The start of the string
  56  * @endp: A pointer to the end of the parsed string will be placed here
  57  * @base: The number base to use
  58  *
  59  * This function is obsolete. Please use kstrtoull instead.
  60  */
  61 unsigned long long simple_strtoull(const char *cp, char **endp, unsigned int base)
  62 {
  63         unsigned long long result;
  64         unsigned int rv;
  65
  66         cp = _parse_integer_fixup_radix(cp, &base);
  67         rv = _parse_integer(cp, base, &result);
  68         /* FIXME */
  69         cp += (rv & ~KSTRTOX_OVERFLOW);
  70
  71         if (endp)
  72                 *endp = (char *)cp;
  73
  74         return result;
  75 }
  76 EXPORT_SYMBOL(simple_strtoull);
  77
  78 /**
  79  * simple_strtoul - convert a string to an unsigned long
  80  * @cp: The start of the string
  81  * @endp: A pointer to the end of the parsed string will be placed here
  82  * @base: The number base to use
  83  *
  84  * This function is obsolete. Please use kstrtoul instead.
  85  */
  86 unsigned long simple_strtoul(const char *cp, char **endp, unsigned int base)
  87 {
  88         return simple_strtoull(cp, endp, base);
  89 }
  90 EXPORT_SYMBOL(simple_strtoul);
  91
  92 /**
  93  * simple_strtol - convert a string to a signed long
  94  * @cp: The start of the string
  95  * @endp: A pointer to the end of the parsed string will be placed here
  96  * @base: The number base to use
  97  *
  98  * This function is obsolete. Please use kstrtol instead.
  99  */
 100 long simple_strtol(const char *cp, char **endp, unsigned int base)
 101 {
 102         if (*cp == '-')
 103                 return -simple_strtoul(cp + 1, endp, base);
 104
 105         return simple_strtoul(cp, endp, base);
 106 }
 107 EXPORT_SYMBOL(simple_strtol);
 108
 109 /**
 110  * simple_strtoll - convert a string to a signed long long
 111  * @cp: The start of the string
 112  * @endp: A pointer to the end of the parsed string will be placed here
 113  * @base: The number base to use
 114  *
 115  * This function is obsolete. Please use kstrtoll instead.
 116  */
 117 long long simple_strtoll(const char *cp, char **endp, unsigned int base)
 118 {
 119         if (*cp == '-')
 120                 return -simple_strtoull(cp + 1, endp, base);
 121
 122         return simple_strtoull(cp, endp, base);
 123 }
 124 EXPORT_SYMBOL(simple_strtoll);
 125
 126 static noinline_for_stack
 127 int skip_atoi(const char **s)
 128 {
 129         int i = 0;
 130
 131         do {
 132                 i = i*10 + *((*s)++) - '0';
 133         } while (isdigit(**s));
 134
 135         return i;
 136 }
 137
 138 /*
 139  * Decimal conversion is by far the most typical, and is used for
 140  * /proc and /sys data. This directly impacts e.g. top performance
 141  * with many processes running. We optimize it for speed by emitting
 142  * two characters at a time, using a 200 byte lookup table. This
 143  * roughly halves the number of multiplications compared to computing
 144  * the digits one at a time. Implementation strongly inspired by the
 145  * previous version, which in turn used ideas described at
 146  * <http://www.cs.uiowa.edu/~jones/bcd/divide.html> (with permission
 147  * from the author, Douglas W. Jones).
 148  *
 149  * It turns out there is precisely one 26 bit fixed-point
 150  * approximation a of 64/100 for which x/100 == (x * (u64)a) >> 32
 151  * holds for all x in [0, 10^8-1], namely a = 0x28f5c29. The actual
 152  * range happens to be somewhat larger (x <= 1073741898), but that's
 153  * irrelevant for our purpose.
 154  *
 155  * For dividing a number in the range [10^4, 10^6-1] by 100, we still
 156  * need a 32x32->64 bit multiply, so we simply use the same constant.
 157  *
 158  * For dividing a number in the range [100, 10^4-1] by 100, there are
 159  * several options. The simplest is (x * 0x147b) >> 19, which is valid
 160  * for all x <= 43698.
 161  */
 162
 163 static const u16 decpair[100] = {
 164 #define _(x) (__force u16) cpu_to_le16(((x % 10) | ((x / 10) << 8)) + 0x3030)
 165         _( 0), _( 1), _( 2), _( 3), _( 4), _( 5), _( 6), _( 7), _( 8), _( 9),
 166         _(10), _(11), _(12), _(13), _(14), _(15), _(16), _(17), _(18), _(19),
 167         _(20), _(21), _(22), _(23), _(24), _(25), _(26), _(27), _(28), _(29),
 168         _(30), _(31), _(32), _(33), _(34), _(35), _(36), _(37), _(38), _(39),
 169         _(40), _(41), _(42), _(43), _(44), _(45), _(46), _(47), _(48), _(49),
 170         _(50), _(51), _(52), _(53), _(54), _(55), _(56), _(57), _(58), _(59),
 171         _(60), _(61), _(62), _(63), _(64), _(65), _(66), _(67), _(68), _(69),
 172         _(70), _(71), _(72), _(73), _(74), _(75), _(76), _(77), _(78), _(79),
 173         _(80), _(81), _(82), _(83), _(84), _(85), _(86), _(87), _(88), _(89),
 174         _(90), _(91), _(92), _(93), _(94), _(95), _(96), _(97), _(98), _(99),
 175 #undef _
 176 };
 177
 178 /*
 179  * This will print a single '0' even if r == 0, since we would
 180  * immediately jump to out_r where two 0s would be written but only
 181  * one of them accounted for in buf. This is needed by ip4_string
 182  * below. All other callers pass a non-zero value of r.
 183 */
 184 static noinline_for_stack
 185 char *put_dec_trunc8(char *buf, unsigned r)
 186 {
 187         unsigned q;
 188
 189         /* 1 <= r < 10^8 */
 190         if (r < 100)
 191                 goto out_r;
 192
 193         /* 100 <= r < 10^8 */
 194         q = (r * (u64)0x28f5c29) >> 32;
 195         *((u16 *)buf) = decpair[r - 100*q];
 196         buf += 2;
 197
 198         /* 1 <= q < 10^6 */
 199         if (q < 100)
 200                 goto out_q;
 201
 202         /*  100 <= q < 10^6 */
 203         r = (q * (u64)0x28f5c29) >> 32;
 204         *((u16 *)buf) = decpair[q - 100*r];
 205         buf += 2;
 206
 207         /* 1 <= r < 10^4 */
 208         if (r < 100)
 209                 goto out_r;
 210
 211         /* 100 <= r < 10^4 */
 212         q = (r * 0x147b) >> 19;
 213         *((u16 *)buf) = decpair[r - 100*q];
 214         buf += 2;
 215 out_q:
 216         /* 1 <= q < 100 */
 217         r = q;
 218 out_r:
 219         /* 1 <= r < 100 */
 220         *((u16 *)buf) = decpair[r];
 221         buf += r < 10 ? 1 : 2;
 222         return buf;
 223 }
 224
 225 #if BITS_PER_LONG == 64 && BITS_PER_LONG_LONG == 64
 226 static noinline_for_stack
 227 char *put_dec_full8(char *buf, unsigned r)
 228 {
 229         unsigned q;
 230
 231         /* 0 <= r < 10^8 */
 232         q = (r * (u64)0x28f5c29) >> 32;
 233         *((u16 *)buf) = decpair[r - 100*q];
 234         buf += 2;
 235
 236         /* 0 <= q < 10^6 */
 237         r = (q * (u64)0x28f5c29) >> 32;
 238         *((u16 *)buf) = decpair[q - 100*r];
 239         buf += 2;
 240
 241         /* 0 <= r < 10^4 */
 242         q = (r * 0x147b) >> 19;
 243         *((u16 *)buf) = decpair[r - 100*q];
 244         buf += 2;
 245
 246         /* 0 <= q < 100 */
 247         *((u16 *)buf) = decpair[q];
 248         buf += 2;
 249         return buf;
 250 }
 251
 252 static noinline_for_stack
 253 char *put_dec(char *buf, unsigned long long n)
 254 {
 255         if (n >= 100*1000*1000)
 256                 buf = put_dec_full8(buf, do_div(n, 100*1000*1000));
 257         /* 1 <= n <= 1.6e11 */
 258         if (n >= 100*1000*1000)
 259                 buf = put_dec_full8(buf, do_div(n, 100*1000*1000));
 260         /* 1 <= n < 1e8 */
 261         return put_dec_trunc8(buf, n);
 262 }
 263
 264 #elif BITS_PER_LONG == 32 && BITS_PER_LONG_LONG == 64
 265
 266 static void
 267 put_dec_full4(char *buf, unsigned r)
 268 {
 269         unsigned q;
 270
 271         /* 0 <= r < 10^4 */
 272         q = (r * 0x147b) >> 19;
 273         *((u16 *)buf) = decpair[r - 100*q];
 274         buf += 2;
 275         /* 0 <= q < 100 */
 276         *((u16 *)buf) = decpair[q];
 277 }
 278
 279 /*
 280  * Call put_dec_full4 on x % 10000, return x / 10000.
 281  * The approximation x/10000 == (x * 0x346DC5D7) >> 43
 282  * holds for all x < 1,128,869,999.  The largest value this
 283  * helper will ever be asked to convert is 1,125,520,955.
 284  * (second call in the put_dec code, assuming n is all-ones).
 285  */
 286 static noinline_for_stack
 287 unsigned put_dec_helper4(char *buf, unsigned x)
 288 {
 289         uint32_t q = (x * (uint64_t)0x346DC5D7) >> 43;
 290
 291         put_dec_full4(buf, x - q * 10000);
 292         return q;
 293 }
 294
 295 /* Based on code by Douglas W. Jones found at
 296  * <http://www.cs.uiowa.edu/~jones/bcd/decimal.html#sixtyfour>
 297  * (with permission from the author).
 298  * Performs no 64-bit division and hence should be fast on 32-bit machines.
 299  */
 300 static
 301 char *put_dec(char *buf, unsigned long long n)
 302 {
 303         uint32_t d3, d2, d1, q, h;
 304
 305         if (n < 100*1000*1000)
 306                 return put_dec_trunc8(buf, n);
 307
 308         d1  = ((uint32_t)n >> 16); /* implicit "& 0xffff" */
 309         h   = (n >> 32);
 310         d2  = (h      ) & 0xffff;
 311         d3  = (h >> 16); /* implicit "& 0xffff" */
 312
 313         /* n = 2^48 d3 + 2^32 d2 + 2^16 d1 + d0
 314              = 281_4749_7671_0656 d3 + 42_9496_7296 d2 + 6_5536 d1 + d0 */
 315         q   = 656 * d3 + 7296 * d2 + 5536 * d1 + ((uint32_t)n & 0xffff);
 316         q = put_dec_helper4(buf, q);
 317
 318         q += 7671 * d3 + 9496 * d2 + 6 * d1;
 319         q = put_dec_helper4(buf+4, q);
 320
 321         q += 4749 * d3 + 42 * d2;
 322         q = put_dec_helper4(buf+8, q);
 323
 324         q += 281 * d3;
 325         buf += 12;
 326         if (q)
 327                 buf = put_dec_trunc8(buf, q);
 328         else while (buf[-1] == '0')
 329                 --buf;
 330
 331         return buf;
 332 }
 333
 334 #endif
 335
 336 /*
 337  * Convert passed number to decimal string.
 338  * Returns the length of string.  On buffer overflow, returns 0.
 339  *
 340  * If speed is not important, use snprintf(). It's easy to read the code.
 341  */
 342 int num_to_str(char *buf, int size, unsigned long long num, unsigned int width)
 343 {
 344         /* put_dec requires 2-byte alignment of the buffer. */
 345         char tmp[sizeof(num) * 3] __aligned(2);
 346         int idx, len;
 347
 348         /* put_dec() may work incorrectly for num = 0 (generate "", not "0") */
 349         if (num <= 9) {
 350                 tmp[0] = '0' + num;
 351                 len = 1;
 352         } else {
 353                 len = put_dec(tmp, num) - tmp;
 354         }
 355
 356         if (len > size || width > size)
 357                 return 0;
 358
 359         if (width > len) {
 360                 width = width - len;
 361                 for (idx = 0; idx < width; idx++)
 362                         buf[idx] = ' ';
 363         } else {
 364                 width = 0;
 365         }
 366
 367         for (idx = 0; idx < len; ++idx)
 368                 buf[idx + width] = tmp[len - idx - 1];
 369
 370         return len + width;
 371 }
 372
 373 #define SIGN    1               /* unsigned/signed, must be 1 */
 374 #define LEFT    2               /* left justified */
 375 #define PLUS    4               /* show plus */
 376 #define SPACE   8               /* space if plus */
 377 #define ZEROPAD 16              /* pad with zero, must be 16 == '0' - ' ' */
 378 #define SMALL   32              /* use lowercase in hex (must be 32 == 0x20) */
 379 #define SPECIAL 64              /* prefix hex with "0x", octal with "0" */
 380
 381 enum format_type {
 382         FORMAT_TYPE_NONE, /* Just a string part */
 383         FORMAT_TYPE_WIDTH,
 384         FORMAT_TYPE_PRECISION,
 385         FORMAT_TYPE_CHAR,
 386         FORMAT_TYPE_STR,
 387         FORMAT_TYPE_PTR,
 388         FORMAT_TYPE_PERCENT_CHAR,
 389         FORMAT_TYPE_INVALID,
 390         FORMAT_TYPE_LONG_LONG,
 391         FORMAT_TYPE_ULONG,
 392         FORMAT_TYPE_LONG,
 393         FORMAT_TYPE_UBYTE,
 394         FORMAT_TYPE_BYTE,
 395         FORMAT_TYPE_USHORT,
 396         FORMAT_TYPE_SHORT,
 397         FORMAT_TYPE_UINT,
 398         FORMAT_TYPE_INT,
 399         FORMAT_TYPE_SIZE_T,
 400         FORMAT_TYPE_PTRDIFF
 401 };
 402
 403 struct printf_spec {
 404         unsigned int    type:8;         /* format_type enum */
 405         signed int      field_width:24; /* width of output field */
 406         unsigned int    flags:8;        /* flags to number() */
 407         unsigned int    base:8;         /* number base, 8, 10 or 16 only */
 408         signed int      precision:16;   /* # of digits/chars */
 409 } __packed;
 410 static_assert(sizeof(struct printf_spec) == 8);
 411
 412 #define FIELD_WIDTH_MAX ((1 << 23) - 1)
 413 #define PRECISION_MAX ((1 << 15) - 1)
 414
 415 static noinline_for_stack
 416 char *number(char *buf, char *end, unsigned long long num,
 417              struct printf_spec spec)
 418 {
 419         /* put_dec requires 2-byte alignment of the buffer. */
 420         char tmp[3 * sizeof(num)] __aligned(2);
 421         char sign;
 422         char locase;
 423         int need_pfx = ((spec.flags & SPECIAL) && spec.base != 10);
 424         int i;
 425         bool is_zero = num == 0LL;
 426         int field_width = spec.field_width;
 427         int precision = spec.precision;
 428
 429         /* locase = 0 or 0x20. ORing digits or letters with 'locase'
 430          * produces same digits or (maybe lowercased) letters */
 431         locase = (spec.flags & SMALL);
 432         if (spec.flags & LEFT)
 433                 spec.flags &= ~ZEROPAD;
 434         sign = 0;
 435         if (spec.flags & SIGN) {
 436                 if ((signed long long)num < 0) {
 437                         sign = '-';
 438                         num = -(signed long long)num;
 439                         field_width--;
 440                 } else if (spec.flags & PLUS) {
 441                         sign = '+';
 442                         field_width--;
 443                 } else if (spec.flags & SPACE) {
 444                         sign = ' ';
 445                         field_width--;
 446                 }
 447         }
 448         if (need_pfx) {
 449                 if (spec.base == 16)
 450                         field_width -= 2;
 451                 else if (!is_zero)
 452                         field_width--;
 453         }
 454
 455         /* generate full string in tmp[], in reverse order */
 456         i = 0;
 457         if (num < spec.base)
 458                 tmp[i++] = hex_asc_upper[num] | locase;
 459         else if (spec.base != 10) { /* 8 or 16 */
 460                 int mask = spec.base - 1;
 461                 int shift = 3;
 462
 463                 if (spec.base == 16)
 464                         shift = 4;
 465                 do {
 466                         tmp[i++] = (hex_asc_upper[((unsigned char)num) & mask] | locase);
 467                         num >>= shift;
 468                 } while (num);
 469         } else { /* base 10 */
 470                 i = put_dec(tmp, num) - tmp;
 471         }
 472
 473         /* printing 100 using %2d gives "100", not "00" */
 474         if (i > precision)
 475                 precision = i;
 476         /* leading space padding */
 477         field_width -= precision;
 478         if (!(spec.flags & (ZEROPAD | LEFT))) {
 479                 while (--field_width >= 0) {
 480                         if (buf < end)
 481                                 *buf = ' ';
 482                         ++buf;
 483                 }
 484         }
 485         /* sign */
 486         if (sign) {
 487                 if (buf < end)
 488                         *buf = sign;
 489                 ++buf;
 490         }
 491         /* "0x" / "0" prefix */
 492         if (need_pfx) {
 493                 if (spec.base == 16 || !is_zero) {
 494                         if (buf < end)
 495                                 *buf = '0';
 496                         ++buf;
 497                 }
 498                 if (spec.base == 16) {
 499                         if (buf < end)
 500                                 *buf = ('X' | locase);
 501                         ++buf;
 502                 }
 503         }
 504         /* zero or space padding */
 505         if (!(spec.flags & LEFT)) {
 506                 char c = ' ' + (spec.flags & ZEROPAD);
 507                 BUILD_BUG_ON(' ' + ZEROPAD != '0');
 508                 while (--field_width >= 0) {
 509                         if (buf < end)
 510                                 *buf = c;
 511                         ++buf;
 512                 }
 513         }
 514         /* hmm even more zero padding? */
 515         while (i <= --precision) {
 516                 if (buf < end)
 517                         *buf = '0';
 518                 ++buf;
 519         }
 520         /* actual digits of result */
 521         while (--i >= 0) {
 522                 if (buf < end)
 523                         *buf = tmp[i];
 524                 ++buf;
 525         }
 526         /* trailing space padding */
 527         while (--field_width >= 0) {
 528                 if (buf < end)
 529                         *buf = ' ';
 530                 ++buf;
 531         }
 532
 533         return buf;
 534 }
 535
 536 static noinline_for_stack
 537 char *special_hex_number(char *buf, char *end, unsigned long long num, int size)
 538 {
 539         struct printf_spec spec;
 540
 541         spec.type = FORMAT_TYPE_PTR;
 542         spec.field_width = 2 + 2 * size;        /* 0x + hex */
 543         spec.flags = SPECIAL | SMALL | ZEROPAD;
 544         spec.base = 16;
 545         spec.precision = -1;
 546
 547         return number(buf, end, num, spec);
 548 }
 549
 550 static void move_right(char *buf, char *end, unsigned len, unsigned spaces)
 551 {
 552         size_t size;
 553         if (buf >= end) /* nowhere to put anything */
 554                 return;
 555         size = end - buf;
 556         if (size <= spaces) {
 557                 memset(buf, ' ', size);
 558                 return;
 559         }
 560         if (len) {
 561                 if (len > size - spaces)
 562                         len = size - spaces;
 563                 memmove(buf + spaces, buf, len);
 564         }
 565         memset(buf, ' ', spaces);
 566 }
 567
 568 /*
 569  * Handle field width padding for a string.
 570  * @buf: current buffer position
 571  * @n: length of string
 572  * @end: end of output buffer
 573  * @spec: for field width and flags
 574  * Returns: new buffer position after padding.
 575  */
 576 static noinline_for_stack
 577 char *widen_string(char *buf, int n, char *end, struct printf_spec spec)
 578 {
 579         unsigned spaces;
 580
 581         if (likely(n >= spec.field_width))
 582                 return buf;
 583         /* we want to pad the sucker */
 584         spaces = spec.field_width - n;
 585         if (!(spec.flags & LEFT)) {
 586                 move_right(buf - n, end, n, spaces);
 587                 return buf + spaces;
 588         }
 589         while (spaces--) {
 590                 if (buf < end)
 591                         *buf = ' ';
 592                 ++buf;
 593         }
 594         return buf;
 595 }
 596
 597 /* Handle string from a well known address. */
 598 static char *string_nocheck(char *buf, char *end, const char *s,
 599                             struct printf_spec spec)
 600 {
 601         int len = 0;
 602         size_t lim = spec.precision;
 603
 604         while (lim--) {
 605                 char c = *s++;
 606                 if (!c)
 607                         break;
 608                 if (buf < end)
 609                         *buf = c;
 610                 ++buf;
 611                 ++len;
 612         }
 613         return widen_string(buf, len, end, spec);
 614 }
 615
 616 /* Be careful: error messages must fit into the given buffer. */
 617 static char *error_string(char *buf, char *end, const char *s,
 618                           struct printf_spec spec)
 619 {
 620         /*
 621          * Hard limit to avoid a completely insane messages. It actually
 622          * works pretty well because most error messages are in
 623          * the many pointer format modifiers.
 624          */
 625         if (spec.precision == -1)
 626                 spec.precision = 2 * sizeof(void *);
 627
 628         return string_nocheck(buf, end, s, spec);
 629 }
 630
 631 /*
 632  * Do not call any complex external code here. Nested printk()/vsprintf()
 633  * might cause infinite loops. Failures might break printk() and would
 634  * be hard to debug.
 635  */
 636 static const char *check_pointer_msg(const void *ptr)
 637 {
 638         if (!ptr)
 639                 return "(null)";
 640
 641         if ((unsigned long)ptr < PAGE_SIZE || IS_ERR_VALUE(ptr))
 642                 return "(efault)";
 643
 644         return NULL;
 645 }
 646
 647 static int check_pointer(char **buf, char *end, const void *ptr,
 648                          struct printf_spec spec)
 649 {
 650         const char *err_msg;
 651
 652         err_msg = check_pointer_msg(ptr);
 653         if (err_msg) {
 654                 *buf = error_string(*buf, end, err_msg, spec);
 655                 return -EFAULT;
 656         }
 657
 658         return 0;
 659 }
 660
 661 static noinline_for_stack
 662 char *string(char *buf, char *end, const char *s,
 663              struct printf_spec spec)
 664 {
 665         if (check_pointer(&buf, end, s, spec))
 666                 return buf;
 667
 668         return string_nocheck(buf, end, s, spec);
 669 }
 670
 671 static char *pointer_string(char *buf, char *end,
 672                             const void *ptr,
 673                             struct printf_spec spec)
 674 {
 675         spec.base = 16;
 676         spec.flags |= SMALL;
 677         if (spec.field_width == -1) {
 678                 spec.field_width = 2 * sizeof(ptr);
 679                 spec.flags |= ZEROPAD;
 680         }
 681
 682         return number(buf, end, (unsigned long int)ptr, spec);
 683 }
 684
 685 /* Make pointers available for printing early in the boot sequence. */
 686 static int debug_boot_weak_hash __ro_after_init;
 687
 688 static int __init debug_boot_weak_hash_enable(char *str)
 689 {
 690         debug_boot_weak_hash = 1;
 691         pr_info("debug_boot_weak_hash enabled\n");
 692         return 0;
 693 }
 694 early_param("debug_boot_weak_hash", debug_boot_weak_hash_enable);
 695
 696 static DEFINE_STATIC_KEY_TRUE(not_filled_random_ptr_key);
 697 static siphash_key_t ptr_key __read_mostly;
 698
 699 static void enable_ptr_key_workfn(struct work_struct *work)
 700 {
 701         get_random_bytes(&ptr_key, sizeof(ptr_key));
 702         /* Needs to run from preemptible context */
 703         static_branch_disable(&not_filled_random_ptr_key);
 704 }
 705
 706 static DECLARE_WORK(enable_ptr_key_work, enable_ptr_key_workfn);
 707
 708 static void fill_random_ptr_key(struct random_ready_callback *unused)
 709 {
 710         /* This may be in an interrupt handler. */
 711         queue_work(system_unbound_wq, &enable_ptr_key_work);
 712 }
 713
 714 static struct random_ready_callback random_ready = {
 715         .func = fill_random_ptr_key
 716 };
 717
 718 static int __init initialize_ptr_random(void)
 719 {
 720         int key_size = sizeof(ptr_key);
 721         int ret;
 722
 723         /* Use hw RNG if available. */
 724         if (get_random_bytes_arch(&ptr_key, key_size) == key_size) {
 725                 static_branch_disable(&not_filled_random_ptr_key);
 726                 return 0;
 727         }
 728
 729         ret = add_random_ready_callback(&random_ready);
 730         if (!ret) {
 731                 return 0;
 732         } else if (ret == -EALREADY) {
 733                 /* This is in preemptible context */
 734                 enable_ptr_key_workfn(&enable_ptr_key_work);
 735                 return 0;
 736         }
 737
 738         return ret;
 739 }
 740 early_initcall(initialize_ptr_random);
 741
 742 /* Maps a pointer to a 32 bit unique identifier. */
 743 static char *ptr_to_id(char *buf, char *end, const void *ptr,
 744                        struct printf_spec spec)
 745 {
 746         const char *str = sizeof(ptr) == 8 ? "(____ptrval____)" : "(ptrval)";
 747         unsigned long hashval;
 748
 749         /* When debugging early boot use non-cryptographically secure hash. */
 750         if (unlikely(debug_boot_weak_hash)) {
 751                 hashval = hash_long((unsigned long)ptr, 32);
 752                 return pointer_string(buf, end, (const void *)hashval, spec);
 753         }
 754
 755         if (static_branch_unlikely(&not_filled_random_ptr_key)) {
 756                 spec.field_width = 2 * sizeof(ptr);
 757                 /* string length must be less than default_width */
 758                 return error_string(buf, end, str, spec);
 759         }
 760
 761 #ifdef CONFIG_64BIT
 762         hashval = (unsigned long)siphash_1u64((u64)ptr, &ptr_key);
 763         /*
 764          * Mask off the first 32 bits, this makes explicit that we have
 765          * modified the address (and 32 bits is plenty for a unique ID).
 766          */
 767         hashval = hashval & 0xffffffff;
 768 #else
 769         hashval = (unsigned long)siphash_1u32((u32)ptr, &ptr_key);
 770 #endif
 771         return pointer_string(buf, end, (const void *)hashval, spec);
 772 }
 773
 774 int kptr_restrict __read_mostly;
 775
 776 static noinline_for_stack
 777 char *restricted_pointer(char *buf, char *end, const void *ptr,
 778                          struct printf_spec spec)
 779 {
 780         switch (kptr_restrict) {
 781         case 0:
 782                 /* Handle as %p, hash and do _not_ leak addresses. */
 783                 return ptr_to_id(buf, end, ptr, spec);
 784         case 1: {
 785                 const struct cred *cred;
 786
 787                 /*
 788                  * kptr_restrict==1 cannot be used in IRQ context
 789                  * because its test for CAP_SYSLOG would be meaningless.
 790                  */
 791                 if (in_irq() || in_serving_softirq() || in_nmi()) {
 792                         if (spec.field_width == -1)
 793                                 spec.field_width = 2 * sizeof(ptr);
 794                         return error_string(buf, end, "pK-error", spec);
 795                 }
 796
 797                 /*
 798                  * Only print the real pointer value if the current
 799                  * process has CAP_SYSLOG and is running with the
 800                  * same credentials it started with. This is because
 801                  * access to files is checked at open() time, but %pK
 802                  * checks permission at read() time. We don't want to
 803                  * leak pointer values if a binary opens a file using
 804                  * %pK and then elevates privileges before reading it.
 805                  */
 806                 cred = current_cred();
 807                 if (!has_capability_noaudit(current, CAP_SYSLOG) ||
 808                     !uid_eq(cred->euid, cred->uid) ||
 809                     !gid_eq(cred->egid, cred->gid))
 810                         ptr = NULL;
 811                 break;
 812         }
 813         case 2:
 814         default:
 815                 /* Always print 0's for %pK */
 816                 ptr = NULL;
 817                 break;
 818         }
 819
 820         return pointer_string(buf, end, ptr, spec);
 821 }
 822
 823 static noinline_for_stack
 824 char *dentry_name(char *buf, char *end, const struct dentry *d, struct printf_spec spec,
 825                   const char *fmt)
 826 {
 827         const char *array[4], *s;
 828         const struct dentry *p;
 829         int depth;
 830         int i, n;
 831
 832         switch (fmt[1]) {
 833                 case '2': case '3': case '4':
 834                         depth = fmt[1] - '0';
 835                         break;
 836                 default:
 837                         depth = 1;
 838         }
 839
 840         rcu_read_lock();
 841         for (i = 0; i < depth; i++, d = p) {
 842                 if (check_pointer(&buf, end, d, spec)) {
 843                         rcu_read_unlock();
 844                         return buf;
 845                 }
 846
 847                 p = READ_ONCE(d->d_parent);
 848                 array[i] = READ_ONCE(d->d_name.name);
 849                 if (p == d) {
 850                         if (i)
 851                                 array[i] = "";
 852                         i++;
 853                         break;
 854                 }
 855         }
 856         s = array[--i];
 857         for (n = 0; n != spec.precision; n++, buf++) {
 858                 char c = *s++;
 859                 if (!c) {
 860                         if (!i)
 861                                 break;
 862                         c = '/';
 863                         s = array[--i];
 864                 }
 865                 if (buf < end)
 866                         *buf = c;
 867         }
 868         rcu_read_unlock();
 869         return widen_string(buf, n, end, spec);
 870 }
 871
 872 #ifdef CONFIG_BLOCK
 873 static noinline_for_stack
 874 char *bdev_name(char *buf, char *end, struct block_device *bdev,
 875                 struct printf_spec spec, const char *fmt)
 876 {
 877         struct gendisk *hd;
 878
 879         if (check_pointer(&buf, end, bdev, spec))
 880                 return buf;
 881
 882         hd = bdev->bd_disk;
 883         buf = string(buf, end, hd->disk_name, spec);
 884         if (bdev->bd_part->partno) {
 885                 if (isdigit(hd->disk_name[strlen(hd->disk_name)-1])) {
 886                         if (buf < end)
 887                                 *buf = 'p';
 888                         buf++;
 889                 }
 890                 buf = number(buf, end, bdev->bd_part->partno, spec);
 891         }
 892         return buf;
 893 }
 894 #endif
 895
 896 static noinline_for_stack
 897 char *symbol_string(char *buf, char *end, void *ptr,
 898                     struct printf_spec spec, const char *fmt)
 899 {
 900         unsigned long value;
 901 #ifdef CONFIG_KALLSYMS
 902         char sym[KSYM_SYMBOL_LEN];
 903 #endif
 904
 905         if (fmt[1] == 'R')
 906                 ptr = __builtin_extract_return_addr(ptr);
 907         value = (unsigned long)ptr;
 908
 909 #ifdef CONFIG_KALLSYMS
 910         if (*fmt == 'B')
 911                 sprint_backtrace(sym, value);
 912         else if (*fmt != 'f' && *fmt != 's')
 913                 sprint_symbol(sym, value);
 914         else
 915                 sprint_symbol_no_offset(sym, value);
 916
 917         return string_nocheck(buf, end, sym, spec);
 918 #else
 919         return special_hex_number(buf, end, value, sizeof(void *));
 920 #endif
 921 }
 922
 923 static const struct printf_spec default_str_spec = {
 924         .field_width = -1,
 925         .precision = -1,
 926 };
 927
 928 static const struct printf_spec default_flag_spec = {
 929         .base = 16,
 930         .precision = -1,
 931         .flags = SPECIAL | SMALL,
 932 };
 933
 934 static const struct printf_spec default_dec_spec = {
 935         .base = 10,
 936         .precision = -1,
 937 };
 938
 939 static const struct printf_spec default_dec02_spec = {
 940         .base = 10,
 941         .field_width = 2,
 942         .precision = -1,
 943         .flags = ZEROPAD,
 944 };
 945
 946 static const struct printf_spec default_dec04_spec = {
 947         .base = 10,
 948         .field_width = 4,
 949         .precision = -1,
 950         .flags = ZEROPAD,
 951 };
 952
 953 static noinline_for_stack
 954 char *resource_string(char *buf, char *end, struct resource *res,
 955                       struct printf_spec spec, const char *fmt)
 956 {
 957 #ifndef IO_RSRC_PRINTK_SIZE
 958 #define IO_RSRC_PRINTK_SIZE     6
 959 #endif
 960
 961 #ifndef MEM_RSRC_PRINTK_SIZE
 962 #define MEM_RSRC_PRINTK_SIZE    10
 963 #endif
 964         static const struct printf_spec io_spec = {
 965                 .base = 16,
 966                 .field_width = IO_RSRC_PRINTK_SIZE,
 967                 .precision = -1,
 968                 .flags = SPECIAL | SMALL | ZEROPAD,
 969         };
 970         static const struct printf_spec mem_spec = {
 971                 .base = 16,
 972                 .field_width = MEM_RSRC_PRINTK_SIZE,
 973                 .precision = -1,
 974                 .flags = SPECIAL | SMALL | ZEROPAD,
 975         };
 976         static const struct printf_spec bus_spec = {
 977                 .base = 16,
 978                 .field_width = 2,
 979                 .precision = -1,
 980                 .flags = SMALL | ZEROPAD,
 981         };
 982         static const struct printf_spec str_spec = {
 983                 .field_width = -1,
 984                 .precision = 10,
 985                 .flags = LEFT,
 986         };
 987
 988         /* 32-bit res (sizeof==4): 10 chars in dec, 10 in hex ("0x" + 8)
 989          * 64-bit res (sizeof==8): 20 chars in dec, 18 in hex ("0x" + 16) */
 990 #define RSRC_BUF_SIZE           ((2 * sizeof(resource_size_t)) + 4)
 991 #define FLAG_BUF_SIZE           (2 * sizeof(res->flags))
 992 #define DECODED_BUF_SIZE        sizeof("[mem - 64bit pref window disabled]")
 993 #define RAW_BUF_SIZE            sizeof("[mem - flags 0x]")
 994         char sym[max(2*RSRC_BUF_SIZE + DECODED_BUF_SIZE,
 995                      2*RSRC_BUF_SIZE + FLAG_BUF_SIZE + RAW_BUF_SIZE)];
 996
 997         char *p = sym, *pend = sym + sizeof(sym);
 998         int decode = (fmt[0] == 'R') ? 1 : 0;
 999         const struct printf_spec *specp;
1000
1001         if (check_pointer(&buf, end, res, spec))
1002                 return buf;
1003
1004         *p++ = '[';
1005         if (res->flags & IORESOURCE_IO) {
1006                 p = string_nocheck(p, pend, "io  ", str_spec);
1007                 specp = &io_spec;
1008         } else if (res->flags & IORESOURCE_MEM) {
1009                 p = string_nocheck(p, pend, "mem ", str_spec);
1010                 specp = &mem_spec;
1011         } else if (res->flags & IORESOURCE_IRQ) {
1012                 p = string_nocheck(p, pend, "irq ", str_spec);
1013                 specp = &default_dec_spec;
1014         } else if (res->flags & IORESOURCE_DMA) {
1015                 p = string_nocheck(p, pend, "dma ", str_spec);
1016                 specp = &default_dec_spec;
1017         } else if (res->flags & IORESOURCE_BUS) {
1018                 p = string_nocheck(p, pend, "bus ", str_spec);
1019                 specp = &bus_spec;
1020         } else {
1021                 p = string_nocheck(p, pend, "??? ", str_spec);
1022                 specp = &mem_spec;
1023                 decode = 0;
1024         }
1025         if (decode && res->flags & IORESOURCE_UNSET) {
1026                 p = string_nocheck(p, pend, "size ", str_spec);
1027                 p = number(p, pend, resource_size(res), *specp);
1028         } else {
1029                 p = number(p, pend, res->start, *specp);
1030                 if (res->start != res->end) {
1031                         *p++ = '-';
1032                         p = number(p, pend, res->end, *specp);
1033                 }
1034         }
1035         if (decode) {
1036                 if (res->flags & IORESOURCE_MEM_64)
1037                         p = string_nocheck(p, pend, " 64bit", str_spec);
1038                 if (res->flags & IORESOURCE_PREFETCH)
1039                         p = string_nocheck(p, pend, " pref", str_spec);
1040                 if (res->flags & IORESOURCE_WINDOW)
1041                         p = string_nocheck(p, pend, " window", str_spec);
1042                 if (res->flags & IORESOURCE_DISABLED)
1043                         p = string_nocheck(p, pend, " disabled", str_spec);
1044         } else {
1045                 p = string_nocheck(p, pend, " flags ", str_spec);
1046                 p = number(p, pend, res->flags, default_flag_spec);
1047         }
1048         *p++ = ']';
1049         *p = '\0';
1050
1051         return string_nocheck(buf, end, sym, spec);
1052 }
1053
1054 static noinline_for_stack
1055 char *hex_string(char *buf, char *end, u8 *addr, struct printf_spec spec,
1056                  const char *fmt)
1057 {
1058         int i, len = 1;         /* if we pass '%ph[CDN]', field width remains
1059                                    negative value, fallback to the default */
1060         char separator;
1061
1062         if (spec.field_width == 0)
1063                 /* nothing to print */
1064                 return buf;
1065
1066         if (check_pointer(&buf, end, addr, spec))
1067                 return buf;
1068
1069         switch (fmt[1]) {
1070         case 'C':
1071                 separator = ':';
1072                 break;
1073         case 'D':
1074                 separator = '-';
1075                 break;
1076         case 'N':
1077                 separator = 0;
1078                 break;
1079         default:
1080                 separator = ' ';
1081                 break;
1082         }
1083
1084         if (spec.field_width > 0)
1085                 len = min_t(int, spec.field_width, 64);
1086
1087         for (i = 0; i < len; ++i) {
1088                 if (buf < end)
1089                         *buf = hex_asc_hi(addr[i]);
1090                 ++buf;
1091                 if (buf < end)
1092                         *buf = hex_asc_lo(addr[i]);
1093                 ++buf;
1094
1095                 if (separator && i != len - 1) {
1096                         if (buf < end)
1097                                 *buf = separator;
1098                         ++buf;
1099                 }
1100         }
1101
1102         return buf;
1103 }
1104
1105 static noinline_for_stack
1106 char *bitmap_string(char *buf, char *end, unsigned long *bitmap,
1107                     struct printf_spec spec, const char *fmt)
1108 {
1109         const int CHUNKSZ = 32;
1110         int nr_bits = max_t(int, spec.field_width, 0);
1111         int i, chunksz;
1112         bool first = true;
1113
1114         if (check_pointer(&buf, end, bitmap, spec))
1115                 return buf;
1116
1117         /* reused to print numbers */
1118         spec = (struct printf_spec){ .flags = SMALL | ZEROPAD, .base = 16 };
1119
1120         chunksz = nr_bits & (CHUNKSZ - 1);
1121         if (chunksz == 0)
1122                 chunksz = CHUNKSZ;
1123
1124         i = ALIGN(nr_bits, CHUNKSZ) - CHUNKSZ;
1125         for (; i >= 0; i -= CHUNKSZ) {
1126                 u32 chunkmask, val;
1127                 int word, bit;
1128
1129                 chunkmask = ((1ULL << chunksz) - 1);
1130                 word = i / BITS_PER_LONG;
1131                 bit = i % BITS_PER_LONG;
1132                 val = (bitmap[word] >> bit) & chunkmask;
1133
1134                 if (!first) {
1135                         if (buf < end)
1136                                 *buf = ',';
1137                         buf++;
1138                 }
1139                 first = false;
1140
1141                 spec.field_width = DIV_ROUND_UP(chunksz, 4);
1142                 buf = number(buf, end, val, spec);
1143
1144                 chunksz = CHUNKSZ;
1145         }
1146         return buf;
1147 }
1148
1149 static noinline_for_stack
1150 char *bitmap_list_string(char *buf, char *end, unsigned long *bitmap,
1151                          struct printf_spec spec, const char *fmt)
1152 {
1153         int nr_bits = max_t(int, spec.field_width, 0);
1154         /* current bit is 'cur', most recently seen range is [rbot, rtop] */
1155         int cur, rbot, rtop;
1156         bool first = true;
1157
1158         if (check_pointer(&buf, end, bitmap, spec))
1159                 return buf;
1160
1161         rbot = cur = find_first_bit(bitmap, nr_bits);
1162         while (cur < nr_bits) {
1163                 rtop = cur;
1164                 cur = find_next_bit(bitmap, nr_bits, cur + 1);
1165                 if (cur < nr_bits && cur <= rtop + 1)
1166                         continue;
1167
1168                 if (!first) {
1169                         if (buf < end)
1170                                 *buf = ',';
1171                         buf++;
1172                 }
1173                 first = false;
1174
1175                 buf = number(buf, end, rbot, default_dec_spec);
1176                 if (rbot < rtop) {
1177                         if (buf < end)
1178                                 *buf = '-';
1179                         buf++;
1180
1181                         buf = number(buf, end, rtop, default_dec_spec);
1182                 }
1183
1184                 rbot = cur;
1185         }
1186         return buf;
1187 }
1188
1189 static noinline_for_stack
1190 char *mac_address_string(char *buf, char *end, u8 *addr,
1191                          struct printf_spec spec, const char *fmt)
1192 {
1193         char mac_addr[sizeof("xx:xx:xx:xx:xx:xx")];
1194         char *p = mac_addr;
1195         int i;
1196         char separator;
1197         bool reversed = false;
1198
1199         if (check_pointer(&buf, end, addr, spec))
1200                 return buf;
1201
1202         switch (fmt[1]) {
1203         case 'F':
1204                 separator = '-';
1205                 break;
1206
1207         case 'R':
1208                 reversed = true;
1209                 /* fall through */
1210
1211         default:
1212                 separator = ':';
1213                 break;
1214         }
1215
1216         for (i = 0; i < 6; i++) {
1217                 if (reversed)
1218                         p = hex_byte_pack(p, addr[5 - i]);
1219                 else
1220                         p = hex_byte_pack(p, addr[i]);
1221
1222                 if (fmt[0] == 'M' && i != 5)
1223                         *p++ = separator;
1224         }
1225         *p = '\0';
1226
1227         return string_nocheck(buf, end, mac_addr, spec);
1228 }
1229
1230 static noinline_for_stack
1231 char *ip4_string(char *p, const u8 *addr, const char *fmt)
1232 {
1233         int i;
1234         bool leading_zeros = (fmt[0] == 'i');
1235         int index;
1236         int step;
1237
1238         switch (fmt[2]) {
1239         case 'h':
1240 #ifdef __BIG_ENDIAN
1241                 index = 0;
1242                 step = 1;
1243 #else
1244                 index = 3;
1245                 step = -1;
1246 #endif
1247                 break;
1248         case 'l':
1249                 index = 3;
1250                 step = -1;
1251                 break;
1252         case 'n':
1253         case 'b':
1254         default:
1255                 index = 0;
1256                 step = 1;
1257                 break;
1258         }
1259         for (i = 0; i < 4; i++) {
1260                 char temp[4] __aligned(2);      /* hold each IP quad in reverse order */
1261                 int digits = put_dec_trunc8(temp, addr[index]) - temp;
1262                 if (leading_zeros) {
1263                         if (digits < 3)
1264                                 *p++ = '0';
1265                         if (digits < 2)
1266                                 *p++ = '0';
1267                 }
1268                 /* reverse the digits in the quad */
1269                 while (digits--)
1270                         *p++ = temp[digits];
1271                 if (i < 3)
1272                         *p++ = '.';
1273                 index += step;
1274         }
1275         *p = '\0';
1276
1277         return p;
1278 }
1279
1280 static noinline_for_stack
1281 char *ip6_compressed_string(char *p, const char *addr)
1282 {
1283         int i, j, range;
1284         unsigned char zerolength[8];
1285         int longest = 1;
1286         int colonpos = -1;
1287         u16 word;
1288         u8 hi, lo;
1289         bool needcolon = false;
1290         bool useIPv4;
1291         struct in6_addr in6;
1292
1293         memcpy(&in6, addr, sizeof(struct in6_addr));
1294
1295         useIPv4 = ipv6_addr_v4mapped(&in6) || ipv6_addr_is_isatap(&in6);
1296
1297         memset(zerolength, 0, sizeof(zerolength));
1298
1299         if (useIPv4)
1300                 range = 6;
1301         else
1302                 range = 8;
1303
1304         /* find position of longest 0 run */
1305         for (i = 0; i < range; i++) {
1306                 for (j = i; j < range; j++) {
1307                         if (in6.s6_addr16[j] != 0)
1308                                 break;
1309                         zerolength[i]++;
1310                 }
1311         }
1312         for (i = 0; i < range; i++) {
1313                 if (zerolength[i] > longest) {
1314                         longest = zerolength[i];
1315                         colonpos = i;
1316                 }
1317         }
1318         if (longest == 1)               /* don't compress a single 0 */
1319                 colonpos = -1;
1320
1321         /* emit address */
1322         for (i = 0; i < range; i++) {
1323                 if (i == colonpos) {
1324                         if (needcolon || i == 0)
1325                                 *p++ = ':';
1326                         *p++ = ':';
1327                         needcolon = false;
1328                         i += longest - 1;
1329                         continue;
1330                 }
1331                 if (needcolon) {
1332                         *p++ = ':';
1333                         needcolon = false;
1334                 }
1335                 /* hex u16 without leading 0s */
1336                 word = ntohs(in6.s6_addr16[i]);
1337                 hi = word >> 8;
1338                 lo = word & 0xff;
1339                 if (hi) {
1340                         if (hi > 0x0f)
1341                                 p = hex_byte_pack(p, hi);
1342                         else
1343                                 *p++ = hex_asc_lo(hi);
1344                         p = hex_byte_pack(p, lo);
1345                 }
1346                 else if (lo > 0x0f)
1347                         p = hex_byte_pack(p, lo);
1348                 else
1349                         *p++ = hex_asc_lo(lo);
1350                 needcolon = true;
1351         }
1352
1353         if (useIPv4) {
1354                 if (needcolon)
1355                         *p++ = ':';
1356                 p = ip4_string(p, &in6.s6_addr[12], "I4");
1357         }
1358         *p = '\0';
1359
1360         return p;
1361 }
1362
1363 static noinline_for_stack
1364 char *ip6_string(char *p, const char *addr, const char *fmt)
1365 {
1366         int i;
1367
1368         for (i = 0; i < 8; i++) {
1369                 p = hex_byte_pack(p, *addr++);
1370                 p = hex_byte_pack(p, *addr++);
1371                 if (fmt[0] == 'I' && i != 7)
1372                         *p++ = ':';
1373         }
1374         *p = '\0';
1375
1376         return p;
1377 }
1378
1379 static noinline_for_stack
1380 char *ip6_addr_string(char *buf, char *end, const u8 *addr,
1381                       struct printf_spec spec, const char *fmt)
1382 {
1383         char ip6_addr[sizeof("xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255")];
1384
1385         if (fmt[0] == 'I' && fmt[2] == 'c')
1386                 ip6_compressed_string(ip6_addr, addr);
1387         else
1388                 ip6_string(ip6_addr, addr, fmt);
1389
1390         return string_nocheck(buf, end, ip6_addr, spec);
1391 }
1392
1393 static noinline_for_stack
1394 char *ip4_addr_string(char *buf, char *end, const u8 *addr,
1395                       struct printf_spec spec, const char *fmt)
1396 {
1397         char ip4_addr[sizeof("255.255.255.255")];
1398
1399         ip4_string(ip4_addr, addr, fmt);
1400
1401         return string_nocheck(buf, end, ip4_addr, spec);
1402 }
1403
1404 static noinline_for_stack
1405 char *ip6_addr_string_sa(char *buf, char *end, const struct sockaddr_in6 *sa,
1406                          struct printf_spec spec, const char *fmt)
1407 {
1408         bool have_p = false, have_s = false, have_f = false, have_c = false;
1409         char ip6_addr[sizeof("[xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255]") +
1410                       sizeof(":12345") + sizeof("/123456789") +
1411                       sizeof("%1234567890")];
1412         char *p = ip6_addr, *pend = ip6_addr + sizeof(ip6_addr);
1413         const u8 *addr = (const u8 *) &sa->sin6_addr;
1414         char fmt6[2] = { fmt[0], '6' };
1415         u8 off = 0;
1416
1417         fmt++;
1418         while (isalpha(*++fmt)) {
1419                 switch (*fmt) {
1420                 case 'p':
1421                         have_p = true;
1422                         break;
1423                 case 'f':
1424                         have_f = true;
1425                         break;
1426                 case 's':
1427                         have_s = true;
1428                         break;
1429                 case 'c':
1430                         have_c = true;
1431                         break;
1432                 }
1433         }
1434
1435         if (have_p || have_s || have_f) {
1436                 *p = '[';
1437                 off = 1;
1438         }
1439
1440         if (fmt6[0] == 'I' && have_c)
1441                 p = ip6_compressed_string(ip6_addr + off, addr);
1442         else
1443                 p = ip6_string(ip6_addr + off, addr, fmt6);
1444
1445         if (have_p || have_s || have_f)
1446                 *p++ = ']';
1447
1448         if (have_p) {
1449                 *p++ = ':';
1450                 p = number(p, pend, ntohs(sa->sin6_port), spec);
1451         }
1452         if (have_f) {
1453                 *p++ = '/';
1454                 p = number(p, pend, ntohl(sa->sin6_flowinfo &
1455                                           IPV6_FLOWINFO_MASK), spec);
1456         }
1457         if (have_s) {
1458                 *p++ = '%';
1459                 p = number(p, pend, sa->sin6_scope_id, spec);
1460         }
1461         *p = '\0';
1462
1463         return string_nocheck(buf, end, ip6_addr, spec);
1464 }
1465
1466 static noinline_for_stack
1467 char *ip4_addr_string_sa(char *buf, char *end, const struct sockaddr_in *sa,
1468                          struct printf_spec spec, const char *fmt)
1469 {
1470         bool have_p = false;
1471         char *p, ip4_addr[sizeof("255.255.255.255") + sizeof(":12345")];
1472         char *pend = ip4_addr + sizeof(ip4_addr);
1473         const u8 *addr = (const u8 *) &sa->sin_addr.s_addr;
1474         char fmt4[3] = { fmt[0], '4', 0 };
1475
1476         fmt++;
1477         while (isalpha(*++fmt)) {
1478                 switch (*fmt) {
1479                 case 'p':
1480                         have_p = true;
1481                         break;
1482                 case 'h':
1483                 case 'l':
1484                 case 'n':
1485                 case 'b':
1486                         fmt4[2] = *fmt;
1487                         break;
1488                 }
1489         }
1490
1491         p = ip4_string(ip4_addr, addr, fmt4);
1492         if (have_p) {
1493                 *p++ = ':';
1494                 p = number(p, pend, ntohs(sa->sin_port), spec);
1495         }
1496         *p = '\0';
1497
1498         return string_nocheck(buf, end, ip4_addr, spec);
1499 }
1500
1501 static noinline_for_stack
1502 char *ip_addr_string(char *buf, char *end, const void *ptr,
1503                      struct printf_spec spec, const char *fmt)
1504 {
1505         char *err_fmt_msg;
1506
1507         if (check_pointer(&buf, end, ptr, spec))
1508                 return buf;
1509
1510         switch (fmt[1]) {
1511         case '6':
1512                 return ip6_addr_string(buf, end, ptr, spec, fmt);
1513         case '4':
1514                 return ip4_addr_string(buf, end, ptr, spec, fmt);
1515         case 'S': {
1516                 const union {
1517                         struct sockaddr         raw;
1518                         struct sockaddr_in      v4;
1519                         struct sockaddr_in6     v6;
1520                 } *sa = ptr;
1521
1522                 switch (sa->raw.sa_family) {
1523                 case AF_INET:
1524                         return ip4_addr_string_sa(buf, end, &sa->v4, spec, fmt);
1525                 case AF_INET6:
1526                         return ip6_addr_string_sa(buf, end, &sa->v6, spec, fmt);
1527                 default:
1528                         return error_string(buf, end, "(einval)", spec);
1529                 }}
1530         }
1531
1532         err_fmt_msg = fmt[0] == 'i' ? "(%pi?)" : "(%pI?)";
1533         return error_string(buf, end, err_fmt_msg, spec);
1534 }
1535
1536 static noinline_for_stack
1537 char *escaped_string(char *buf, char *end, u8 *addr, struct printf_spec spec,
1538                      const char *fmt)
1539 {
1540         bool found = true;
1541         int count = 1;
1542         unsigned int flags = 0;
1543         int len;
1544
1545         if (spec.field_width == 0)
1546                 return buf;                             /* nothing to print */
1547
1548         if (check_pointer(&buf, end, addr, spec))
1549                 return buf;
1550
1551         do {
1552                 switch (fmt[count++]) {
1553                 case 'a':
1554                         flags |= ESCAPE_ANY;
1555                         break;
1556                 case 'c':
1557                         flags |= ESCAPE_SPECIAL;
1558                         break;
1559                 case 'h':
1560                         flags |= ESCAPE_HEX;
1561                         break;
1562                 case 'n':
1563                         flags |= ESCAPE_NULL;
1564                         break;
1565                 case 'o':
1566                         flags |= ESCAPE_OCTAL;
1567                         break;
1568                 case 'p':
1569                         flags |= ESCAPE_NP;
1570                         break;
1571                 case 's':
1572                         flags |= ESCAPE_SPACE;
1573                         break;
1574                 default:
1575                         found = false;
1576                         break;
1577                 }
1578         } while (found);
1579
1580         if (!flags)
1581                 flags = ESCAPE_ANY_NP;
1582
1583         len = spec.field_width < 0 ? 1 : spec.field_width;
1584
1585         /*
1586          * string_escape_mem() writes as many characters as it can to
1587          * the given buffer, and returns the total size of the output
1588          * had the buffer been big enough.
1589          */
1590         buf += string_escape_mem(addr, len, buf, buf < end ? end - buf : 0, flags, NULL);
1591
1592         return buf;
1593 }
1594
1595 static char *va_format(char *buf, char *end, struct va_format *va_fmt,
1596                        struct printf_spec spec, const char *fmt)
1597 {
1598         va_list va;
1599
1600         if (check_pointer(&buf, end, va_fmt, spec))
1601                 return buf;
1602
1603         va_copy(va, *va_fmt->va);
1604         buf += vsnprintf(buf, end > buf ? end - buf : 0, va_fmt->fmt, va);
1605         va_end(va);
1606
1607         return buf;
1608 }
1609
1610 static noinline_for_stack
1611 char *uuid_string(char *buf, char *end, const u8 *addr,
1612                   struct printf_spec spec, const char *fmt)
1613 {
1614         char uuid[UUID_STRING_LEN + 1];
1615         char *p = uuid;
1616         int i;
1617         const u8 *index = uuid_index;
1618         bool uc = false;
1619
1620         if (check_pointer(&buf, end, addr, spec))
1621                 return buf;
1622
1623         switch (*(++fmt)) {
1624         case 'L':
1625                 uc = true;              /* fall-through */
1626         case 'l':
1627                 index = guid_index;
1628                 break;
1629         case 'B':
1630                 uc = true;
1631                 break;
1632         }
1633
1634         for (i = 0; i < 16; i++) {
1635                 if (uc)
1636                         p = hex_byte_pack_upper(p, addr[index[i]]);
1637                 else
1638                         p = hex_byte_pack(p, addr[index[i]]);
1639                 switch (i) {
1640                 case 3:
1641                 case 5:
1642                 case 7:
1643                 case 9:
1644                         *p++ = '-';
1645                         break;
1646                 }
1647         }
1648
1649         *p = 0;
1650
1651         return string_nocheck(buf, end, uuid, spec);
1652 }
1653
1654 static noinline_for_stack
1655 char *netdev_bits(char *buf, char *end, const void *addr,
1656                   struct printf_spec spec,  const char *fmt)
1657 {
1658         unsigned long long num;
1659         int size;
1660
1661         if (check_pointer(&buf, end, addr, spec))
1662                 return buf;
1663
1664         switch (fmt[1]) {
1665         case 'F':
1666                 num = *(const netdev_features_t *)addr;
1667                 size = sizeof(netdev_features_t);
1668                 break;
1669         default:
1670                 return error_string(buf, end, "(%pN?)", spec);
1671         }
1672
1673         return special_hex_number(buf, end, num, size);
1674 }
1675
1676 static noinline_for_stack
1677 char *address_val(char *buf, char *end, const void *addr,
1678                   struct printf_spec spec, const char *fmt)
1679 {
1680         unsigned long long num;
1681         int size;
1682
1683         if (check_pointer(&buf, end, addr, spec))
1684                 return buf;
1685
1686         switch (fmt[1]) {
1687         case 'd':
1688                 num = *(const dma_addr_t *)addr;
1689                 size = sizeof(dma_addr_t);
1690                 break;
1691         case 'p':
1692         default:
1693                 num = *(const phys_addr_t *)addr;
1694                 size = sizeof(phys_addr_t);
1695                 break;
1696         }
1697
1698         return special_hex_number(buf, end, num, size);
1699 }
1700
1701 static noinline_for_stack
1702 char *date_str(char *buf, char *end, const struct rtc_time *tm, bool r)
1703 {
1704         int year = tm->tm_year + (r ? 0 : 1900);
1705         int mon = tm->tm_mon + (r ? 0 : 1);
1706
1707         buf = number(buf, end, year, default_dec04_spec);
1708         if (buf < end)
1709                 *buf = '-';
1710         buf++;
1711
1712         buf = number(buf, end, mon, default_dec02_spec);
1713         if (buf < end)
1714                 *buf = '-';
1715         buf++;
1716
1717         return number(buf, end, tm->tm_mday, default_dec02_spec);
1718 }
1719
1720 static noinline_for_stack
1721 char *time_str(char *buf, char *end, const struct rtc_time *tm, bool r)
1722 {
1723         buf = number(buf, end, tm->tm_hour, default_dec02_spec);
1724         if (buf < end)
1725                 *buf = ':';
1726         buf++;
1727
1728         buf = number(buf, end, tm->tm_min, default_dec02_spec);
1729         if (buf < end)
1730                 *buf = ':';
1731         buf++;
1732
1733         return number(buf, end, tm->tm_sec, default_dec02_spec);
1734 }
1735
1736 static noinline_for_stack
1737 char *rtc_str(char *buf, char *end, const struct rtc_time *tm,
1738               struct printf_spec spec, const char *fmt)
1739 {
1740         bool have_t = true, have_d = true;
1741         bool raw = false;
1742         int count = 2;
1743
1744         if (check_pointer(&buf, end, tm, spec))
1745                 return buf;
1746
1747         switch (fmt[count]) {
1748         case 'd':
1749                 have_t = false;
1750                 count++;
1751                 break;
1752         case 't':
1753                 have_d = false;
1754                 count++;
1755                 break;
1756         }
1757
1758         raw = fmt[count] == 'r';
1759
1760         if (have_d)
1761                 buf = date_str(buf, end, tm, raw);
1762         if (have_d && have_t) {
1763                 /* Respect ISO 8601 */
1764                 if (buf < end)
1765                         *buf = 'T';
1766                 buf++;
1767         }
1768         if (have_t)
1769                 buf = time_str(buf, end, tm, raw);
1770
1771         return buf;
1772 }
1773
1774 static noinline_for_stack
1775 char *time_and_date(char *buf, char *end, void *ptr, struct printf_spec spec,
1776                     const char *fmt)
1777 {
1778         switch (fmt[1]) {
1779         case 'R':
1780                 return rtc_str(buf, end, (const struct rtc_time *)ptr, spec, fmt);
1781         default:
1782                 return error_string(buf, end, "(%ptR?)", spec);
1783         }
1784 }
1785
1786 static noinline_for_stack
1787 char *clock(char *buf, char *end, struct clk *clk, struct printf_spec spec,
1788             const char *fmt)
1789 {
1790         if (!IS_ENABLED(CONFIG_HAVE_CLK))
1791                 return error_string(buf, end, "(%pC?)", spec);
1792
1793         if (check_pointer(&buf, end, clk, spec))
1794                 return buf;
1795
1796         switch (fmt[1]) {
1797         case 'n':
1798         default:
1799 #ifdef CONFIG_COMMON_CLK
1800                 return string(buf, end, __clk_get_name(clk), spec);
1801 #else
1802                 return error_string(buf, end, "(%pC?)", spec);
1803 #endif
1804         }
1805 }
1806
1807 static
1808 char *format_flags(char *buf, char *end, unsigned long flags,
1809                                         const struct trace_print_flags *names)
1810 {
1811         unsigned long mask;
1812
1813         for ( ; flags && names->name; names++) {
1814                 mask = names->mask;
1815                 if ((flags & mask) != mask)
1816                         continue;
1817
1818                 buf = string(buf, end, names->name, default_str_spec);
1819
1820                 flags &= ~mask;
1821                 if (flags) {
1822                         if (buf < end)
1823                                 *buf = '|';
1824                         buf++;
1825                 }
1826         }
1827
1828         if (flags)
1829                 buf = number(buf, end, flags, default_flag_spec);
1830
1831         return buf;
1832 }
1833
1834 static noinline_for_stack
1835 char *flags_string(char *buf, char *end, void *flags_ptr,
1836                    struct printf_spec spec, const char *fmt)
1837 {
1838         unsigned long flags;
1839         const struct trace_print_flags *names;
1840
1841         if (check_pointer(&buf, end, flags_ptr, spec))
1842                 return buf;
1843
1844         switch (fmt[1]) {
1845         case 'p':
1846                 flags = *(unsigned long *)flags_ptr;
1847                 /* Remove zone id */
1848                 flags &= (1UL << NR_PAGEFLAGS) - 1;
1849                 names = pageflag_names;
1850                 break;
1851         case 'v':
1852                 flags = *(unsigned long *)flags_ptr;
1853                 names = vmaflag_names;
1854                 break;
1855         case 'g':
1856                 flags = *(gfp_t *)flags_ptr;
1857                 names = gfpflag_names;
1858                 break;
1859         default:
1860                 return error_string(buf, end, "(%pG?)", spec);
1861         }
1862
1863         return format_flags(buf, end, flags, names);
1864 }
1865
1866 static const char *device_node_name_for_depth(const struct device_node *np, int depth)
1867 {
1868         for ( ; np && depth; depth--)
1869                 np = np->parent;
1870
1871         return kbasename(np->full_name);
1872 }
1873
1874 static noinline_for_stack
1875 char *device_node_gen_full_name(const struct device_node *np, char *buf, char *end)
1876 {
1877         int depth;
1878         const struct device_node *parent = np->parent;
1879
1880         /* special case for root node */
1881         if (!parent)
1882                 return string_nocheck(buf, end, "/", default_str_spec);
1883
1884         for (depth = 0; parent->parent; depth++)
1885                 parent = parent->parent;
1886
1887         for ( ; depth >= 0; depth--) {
1888                 buf = string_nocheck(buf, end, "/", default_str_spec);
1889                 buf = string(buf, end, device_node_name_for_depth(np, depth),
1890                              default_str_spec);
1891         }
1892         return buf;
1893 }
1894
1895 static noinline_for_stack
1896 char *device_node_string(char *buf, char *end, struct device_node *dn,
1897                          struct printf_spec spec, const char *fmt)
1898 {
1899         char tbuf[sizeof("xxxx") + 1];
1900         const char *p;
1901         int ret;
1902         char *buf_start = buf;
1903         struct property *prop;
1904         bool has_mult, pass;
1905         static const struct printf_spec num_spec = {
1906                 .flags = SMALL,
1907                 .field_width = -1,
1908                 .precision = -1,
1909                 .base = 10,
1910         };
1911
1912         struct printf_spec str_spec = spec;
1913         str_spec.field_width = -1;
1914
1915         if (!IS_ENABLED(CONFIG_OF))
1916                 return error_string(buf, end, "(%pOF?)", spec);
1917
1918         if (check_pointer(&buf, end, dn, spec))
1919                 return buf;
1920
1921         /* simple case without anything any more format specifiers */
1922         fmt++;
1923         if (fmt[0] == '\0' || strcspn(fmt,"fnpPFcC") > 0)
1924                 fmt = "f";
1925
1926         for (pass = false; strspn(fmt,"fnpPFcC"); fmt++, pass = true) {
1927                 int precision;
1928                 if (pass) {
1929                         if (buf < end)
1930                                 *buf = ':';
1931                         buf++;
1932                 }
1933
1934                 switch (*fmt) {
1935                 case 'f':       /* full_name */
1936                         buf = device_node_gen_full_name(dn, buf, end);
1937                         break;
1938                 case 'n':       /* name */
1939                         p = kbasename(of_node_full_name(dn));
1940                         precision = str_spec.precision;
1941                         str_spec.precision = strchrnul(p, '@') - p;
1942                         buf = string(buf, end, p, str_spec);
1943                         str_spec.precision = precision;
1944                         break;
1945                 case 'p':       /* phandle */
1946                         buf = number(buf, end, (unsigned int)dn->phandle, num_spec);
1947                         break;
1948                 case 'P':       /* path-spec */
1949                         p = kbasename(of_node_full_name(dn));
1950                         if (!p[1])
1951                                 p = "/";
1952                         buf = string(buf, end, p, str_spec);
1953                         break;
1954                 case 'F':       /* flags */
1955                         tbuf[0] = of_node_check_flag(dn, OF_DYNAMIC) ? 'D' : '-';
1956                         tbuf[1] = of_node_check_flag(dn, OF_DETACHED) ? 'd' : '-';
1957                         tbuf[2] = of_node_check_flag(dn, OF_POPULATED) ? 'P' : '-';
1958                         tbuf[3] = of_node_check_flag(dn, OF_POPULATED_BUS) ? 'B' : '-';
1959                         tbuf[4] = 0;
1960                         buf = string_nocheck(buf, end, tbuf, str_spec);
1961                         break;
1962                 case 'c':       /* major compatible string */
1963                         ret = of_property_read_string(dn, "compatible", &p);
1964                         if (!ret)
1965                                 buf = string(buf, end, p, str_spec);
1966                         break;
1967                 case 'C':       /* full compatible string */
1968                         has_mult = false;
1969                         of_property_for_each_string(dn, "compatible", prop, p) {
1970                                 if (has_mult)
1971                                         buf = string_nocheck(buf, end, ",", str_spec);
1972                                 buf = string_nocheck(buf, end, "\"", str_spec);
1973                                 buf = string(buf, end, p, str_spec);
1974                                 buf = string_nocheck(buf, end, "\"", str_spec);
1975
1976                                 has_mult = true;
1977                         }
1978                         break;
1979                 default:
1980                         break;
1981                 }
1982         }
1983
1984         return widen_string(buf, buf - buf_start, end, spec);
1985 }
1986
1987 static char *kobject_string(char *buf, char *end, void *ptr,
1988                             struct printf_spec spec, const char *fmt)
1989 {
1990         switch (fmt[1]) {
1991         case 'F':
1992                 return device_node_string(buf, end, ptr, spec, fmt + 1);
1993         }
1994
1995         return error_string(buf, end, "(%pO?)", spec);
1996 }
1997
1998 /*
1999  * Show a '%p' thing.  A kernel extension is that the '%p' is followed
2000  * by an extra set of alphanumeric characters that are extended format
2001  * specifiers.
2002  *
2003  * Please update scripts/checkpatch.pl when adding/removing conversion
2004  * characters.  (Search for "check for vsprintf extension").
2005  *
2006  * Right now we handle:
2007  *
2008  * - 'S' For symbolic direct pointers (or function descriptors) with offset
2009  * - 's' For symbolic direct pointers (or function descriptors) without offset
2010  * - 'F' Same as 'S'
2011  * - 'f' Same as 's'
2012  * - '[FfSs]R' as above with __builtin_extract_return_addr() translation
2013  * - 'B' For backtraced symbolic direct pointers with offset
2014  * - 'R' For decoded struct resource, e.g., [mem 0x0-0x1f 64bit pref]
2015  * - 'r' For raw struct resource, e.g., [mem 0x0-0x1f flags 0x201]
2016  * - 'b[l]' For a bitmap, the number of bits is determined by the field
2017  *       width which must be explicitly specified either as part of the
2018  *       format string '%32b[l]' or through '%*b[l]', [l] selects
2019  *       range-list format instead of hex format
2020  * - 'M' For a 6-byte MAC address, it prints the address in the
2021  *       usual colon-separated hex notation
2022  * - 'm' For a 6-byte MAC address, it prints the hex address without colons
2023  * - 'MF' For a 6-byte MAC FDDI address, it prints the address
2024  *       with a dash-separated hex notation
2025  * - '[mM]R' For a 6-byte MAC address, Reverse order (Bluetooth)
2026  * - 'I' [46] for IPv4/IPv6 addresses printed in the usual way
2027  *       IPv4 uses dot-separated decimal without leading 0's (1.2.3.4)
2028  *       IPv6 uses colon separated network-order 16 bit hex with leading 0's
2029  *       [S][pfs]
2030  *       Generic IPv4/IPv6 address (struct sockaddr *) that falls back to
2031  *       [4] or [6] and is able to print port [p], flowinfo [f], scope [s]
2032  * - 'i' [46] for 'raw' IPv4/IPv6 addresses
2033  *       IPv6 omits the colons (01020304...0f)
2034  *       IPv4 uses dot-separated decimal with leading 0's (010.123.045.006)
2035  *       [S][pfs]
2036  *       Generic IPv4/IPv6 address (struct sockaddr *) that falls back to
2037  *       [4] or [6] and is able to print port [p], flowinfo [f], scope [s]
2038  * - '[Ii][4S][hnbl]' IPv4 addresses in host, network, big or little endian order
2039  * - 'I[6S]c' for IPv6 addresses printed as specified by
2040  *       http://tools.ietf.org/html/rfc5952
2041  * - 'E[achnops]' For an escaped buffer, where rules are defined by combination
2042  *                of the following flags (see string_escape_mem() for the
2043  *                details):
2044  *                  a - ESCAPE_ANY
2045  *                  c - ESCAPE_SPECIAL
2046  *                  h - ESCAPE_HEX
2047  *                  n - ESCAPE_NULL
2048  *                  o - ESCAPE_OCTAL
2049  *                  p - ESCAPE_NP
2050  *                  s - ESCAPE_SPACE
2051  *                By default ESCAPE_ANY_NP is used.
2052  * - 'U' For a 16 byte UUID/GUID, it prints the UUID/GUID in the form
2053  *       "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx"
2054  *       Options for %pU are:
2055  *         b big endian lower case hex (default)
2056  *         B big endian UPPER case hex
2057  *         l little endian lower case hex
2058  *         L little endian UPPER case hex
2059  *           big endian output byte order is:
2060  *             [0][1][2][3]-[4][5]-[6][7]-[8][9]-[10][11][12][13][14][15]
2061  *           little endian output byte order is:
2062  *             [3][2][1][0]-[5][4]-[7][6]-[8][9]-[10][11][12][13][14][15]
2063  * - 'V' For a struct va_format which contains a format string * and va_list *,
2064  *       call vsnprintf(->format, *->va_list).
2065  *       Implements a "recursive vsnprintf".
2066  *       Do not use this feature without some mechanism to verify the
2067  *       correctness of the format string and va_list arguments.
2068  * - 'K' For a kernel pointer that should be hidden from unprivileged users
2069  * - 'NF' For a netdev_features_t
2070  * - 'h[CDN]' For a variable-length buffer, it prints it as a hex string with
2071  *            a certain separator (' ' by default):
2072  *              C colon
2073  *              D dash
2074  *              N no separator
2075  *            The maximum supported length is 64 bytes of the input. Consider
2076  *            to use print_hex_dump() for the larger input.
2077  * - 'a[pd]' For address types [p] phys_addr_t, [d] dma_addr_t and derivatives
2078  *           (default assumed to be phys_addr_t, passed by reference)
2079  * - 'd[234]' For a dentry name (optionally 2-4 last components)
2080  * - 'D[234]' Same as 'd' but for a struct file
2081  * - 'g' For block_device name (gendisk + partition number)
2082  * - 't[R][dt][r]' For time and date as represented:
2083  *      R    struct rtc_time
2084  * - 'C' For a clock, it prints the name (Common Clock Framework) or address
2085  *       (legacy clock framework) of the clock
2086  * - 'Cn' For a clock, it prints the name (Common Clock Framework) or address
2087  *        (legacy clock framework) of the clock
2088  * - 'G' For flags to be printed as a collection of symbolic strings that would
2089  *       construct the specific value. Supported flags given by option:
2090  *       p page flags (see struct page) given as pointer to unsigned long
2091  *       g gfp flags (GFP_* and __GFP_*) given as pointer to gfp_t
2092  *       v vma flags (VM_*) given as pointer to unsigned long
2093  * - 'OF[fnpPcCF]'  For a device tree object
2094  *                  Without any optional arguments prints the full_name
2095  *                  f device node full_name
2096  *                  n device node name
2097  *                  p device node phandle
2098  *                  P device node path spec (name + @unit)
2099  *                  F device node flags
2100  *                  c major compatible string
2101  *                  C full compatible string
2102  * - 'x' For printing the address. Equivalent to "%lx".
2103  *
2104  * ** When making changes please also update:
2105  *      Documentation/core-api/printk-formats.rst
2106  *
2107  * Note: The default behaviour (unadorned %p) is to hash the address,
2108  * rendering it useful as a unique identifier.
2109  */
2110 static noinline_for_stack
2111 char *pointer(const char *fmt, char *buf, char *end, void *ptr,
2112               struct printf_spec spec)
2113 {
2114         switch (*fmt) {
2115         case 'F':
2116         case 'f':
2117         case 'S':
2118         case 's':
2119                 ptr = dereference_symbol_descriptor(ptr);
2120                 /* Fallthrough */
2121         case 'B':
2122                 return symbol_string(buf, end, ptr, spec, fmt);
2123         case 'R':
2124         case 'r':
2125                 return resource_string(buf, end, ptr, spec, fmt);
2126         case 'h':
2127                 return hex_string(buf, end, ptr, spec, fmt);
2128         case 'b':
2129                 switch (fmt[1]) {
2130                 case 'l':
2131                         return bitmap_list_string(buf, end, ptr, spec, fmt);
2132                 default:
2133                         return bitmap_string(buf, end, ptr, spec, fmt);
2134                 }
2135         case 'M':                       /* Colon separated: 00:01:02:03:04:05 */
2136         case 'm':                       /* Contiguous: 000102030405 */
2137                                         /* [mM]F (FDDI) */
2138                                         /* [mM]R (Reverse order; Bluetooth) */
2139                 return mac_address_string(buf, end, ptr, spec, fmt);
2140         case 'I':                       /* Formatted IP supported
2141                                          * 4:   1.2.3.4
2142                                          * 6:   0001:0203:...:0708
2143                                          * 6c:  1::708 or 1::1.2.3.4
2144                                          */
2145         case 'i':                       /* Contiguous:
2146                                          * 4:   001.002.003.004
2147                                          * 6:   000102...0f
2148                                          */
2149                 return ip_addr_string(buf, end, ptr, spec, fmt);
2150         case 'E':
2151                 return escaped_string(buf, end, ptr, spec, fmt);
2152         case 'U':
2153                 return uuid_string(buf, end, ptr, spec, fmt);
2154         case 'V':
2155                 return va_format(buf, end, ptr, spec, fmt);
2156         case 'K':
2157                 return restricted_pointer(buf, end, ptr, spec);
2158         case 'N':
2159                 return netdev_bits(buf, end, ptr, spec, fmt);
2160         case 'a':
2161                 return address_val(buf, end, ptr, spec, fmt);
2162         case 'd':
2163                 return dentry_name(buf, end, ptr, spec, fmt);
2164         case 't':
2165                 return time_and_date(buf, end, ptr, spec, fmt);
2166         case 'C':
2167                 return clock(buf, end, ptr, spec, fmt);
2168         case 'D':
2169                 return dentry_name(buf, end,
2170                                    ((const struct file *)ptr)->f_path.dentry,
2171                                    spec, fmt);
2172 #ifdef CONFIG_BLOCK
2173         case 'g':
2174                 return bdev_name(buf, end, ptr, spec, fmt);
2175 #endif
2176
2177         case 'G':
2178                 return flags_string(buf, end, ptr, spec, fmt);
2179         case 'O':
2180                 return kobject_string(buf, end, ptr, spec, fmt);
2181         case 'x':
2182                 return pointer_string(buf, end, ptr, spec);
2183         }
2184
2185         /* default is to _not_ leak addresses, hash before printing */
2186         return ptr_to_id(buf, end, ptr, spec);
2187 }
2188
2189 /*
2190  * Helper function to decode printf style format.
2191  * Each call decode a token from the format and return the
2192  * number of characters read (or likely the delta where it wants
2193  * to go on the next call).
2194  * The decoded token is returned through the parameters
2195  *
2196  * 'h', 'l', or 'L' for integer fields
2197  * 'z' support added 23/7/1999 S.H.
2198  * 'z' changed to 'Z' --davidm 1/25/99
2199  * 'Z' changed to 'z' --adobriyan 2017-01-25
2200  * 't' added for ptrdiff_t
2201  *
2202  * @fmt: the format string
2203  * @type of the token returned
2204  * @flags: various flags such as +, -, # tokens..
2205  * @field_width: overwritten width
2206  * @base: base of the number (octal, hex, ...)
2207  * @precision: precision of a number
2208  * @qualifier: qualifier of a number (long, size_t, ...)
2209  */
2210 static noinline_for_stack
2211 int format_decode(const char *fmt, struct printf_spec *spec)
2212 {
2213         const char *start = fmt;
2214         char qualifier;
2215
2216         /* we finished early by reading the field width */
2217         if (spec->type == FORMAT_TYPE_WIDTH) {
2218                 if (spec->field_width < 0) {
2219                         spec->field_width = -spec->field_width;
2220                         spec->flags |= LEFT;
2221                 }
2222                 spec->type = FORMAT_TYPE_NONE;
2223                 goto precision;
2224         }
2225
2226         /* we finished early by reading the precision */
2227         if (spec->type == FORMAT_TYPE_PRECISION) {
2228                 if (spec->precision < 0)
2229                         spec->precision = 0;
2230
2231                 spec->type = FORMAT_TYPE_NONE;
2232                 goto qualifier;
2233         }
2234
2235         /* By default */
2236         spec->type = FORMAT_TYPE_NONE;
2237
2238         for (; *fmt ; ++fmt) {
2239                 if (*fmt == '%')
2240                         break;
2241         }
2242
2243         /* Return the current non-format string */
2244         if (fmt != start || !*fmt)
2245                 return fmt - start;
2246
2247         /* Process flags */
2248         spec->flags = 0;
2249
2250         while (1) { /* this also skips first '%' */
2251                 bool found = true;
2252
2253                 ++fmt;
2254
2255                 switch (*fmt) {
2256                 case '-': spec->flags |= LEFT;    break;
2257                 case '+': spec->flags |= PLUS;    break;
2258                 case ' ': spec->flags |= SPACE;   break;
2259                 case '#': spec->flags |= SPECIAL; break;
2260                 case '0': spec->flags |= ZEROPAD; break;
2261                 default:  found = false;
2262                 }
2263
2264                 if (!found)
2265                         break;
2266         }
2267
2268         /* get field width */
2269         spec->field_width = -1;
2270
2271         if (isdigit(*fmt))
2272                 spec->field_width = skip_atoi(&fmt);
2273         else if (*fmt == '*') {
2274                 /* it's the next argument */
2275                 spec->type = FORMAT_TYPE_WIDTH;
2276                 return ++fmt - start;
2277         }
2278
2279 precision:
2280         /* get the precision */
2281         spec->precision = -1;
2282         if (*fmt == '.') {
2283                 ++fmt;
2284                 if (isdigit(*fmt)) {
2285                         spec->precision = skip_atoi(&fmt);
2286                         if (spec->precision < 0)
2287                                 spec->precision = 0;
2288                 } else if (*fmt == '*') {
2289                         /* it's the next argument */
2290                         spec->type = FORMAT_TYPE_PRECISION;
2291                         return ++fmt - start;
2292                 }
2293         }
2294
2295 qualifier:
2296         /* get the conversion qualifier */
2297         qualifier = 0;
2298         if (*fmt == 'h' || _tolower(*fmt) == 'l' ||
2299             *fmt == 'z' || *fmt == 't') {
2300                 qualifier = *fmt++;
2301                 if (unlikely(qualifier == *fmt)) {
2302                         if (qualifier == 'l') {
2303                                 qualifier = 'L';
2304                                 ++fmt;
2305                         } else if (qualifier == 'h') {
2306                                 qualifier = 'H';
2307                                 ++fmt;
2308                         }
2309                 }
2310         }
2311
2312         /* default base */
2313         spec->base = 10;
2314         switch (*fmt) {
2315         case 'c':
2316                 spec->type = FORMAT_TYPE_CHAR;
2317                 return ++fmt - start;
2318
2319         case 's':
2320                 spec->type = FORMAT_TYPE_STR;
2321                 return ++fmt - start;
2322
2323         case 'p':
2324                 spec->type = FORMAT_TYPE_PTR;
2325                 return ++fmt - start;
2326
2327         case '%':
2328                 spec->type = FORMAT_TYPE_PERCENT_CHAR;
2329                 return ++fmt - start;
2330
2331         /* integer number formats - set up the flags and "break" */
2332         case 'o':
2333                 spec->base = 8;
2334                 break;
2335
2336         case 'x':
2337                 spec->flags |= SMALL;
2338                 /* fall through */
2339
2340         case 'X':
2341                 spec->base = 16;
2342                 break;
2343
2344         case 'd':
2345         case 'i':
2346                 spec->flags |= SIGN;
2347         case 'u':
2348                 break;
2349
2350         case 'n':
2351                 /*
2352                  * Since %n poses a greater security risk than
2353                  * utility, treat it as any other invalid or
2354                  * unsupported format specifier.
2355                  */
2356                 /* Fall-through */
2357
2358         default:
2359                 WARN_ONCE(1, "Please remove unsupported %%%c in format string\n", *fmt);
2360                 spec->type = FORMAT_TYPE_INVALID;
2361                 return fmt - start;
2362         }
2363
2364         if (qualifier == 'L')
2365                 spec->type = FORMAT_TYPE_LONG_LONG;
2366         else if (qualifier == 'l') {
2367                 BUILD_BUG_ON(FORMAT_TYPE_ULONG + SIGN != FORMAT_TYPE_LONG);
2368                 spec->type = FORMAT_TYPE_ULONG + (spec->flags & SIGN);
2369         } else if (qualifier == 'z') {
2370                 spec->type = FORMAT_TYPE_SIZE_T;
2371         } else if (qualifier == 't') {
2372                 spec->type = FORMAT_TYPE_PTRDIFF;
2373         } else if (qualifier == 'H') {
2374                 BUILD_BUG_ON(FORMAT_TYPE_UBYTE + SIGN != FORMAT_TYPE_BYTE);
2375                 spec->type = FORMAT_TYPE_UBYTE + (spec->flags & SIGN);
2376         } else if (qualifier == 'h') {
2377                 BUILD_BUG_ON(FORMAT_TYPE_USHORT + SIGN != FORMAT_TYPE_SHORT);
2378                 spec->type = FORMAT_TYPE_USHORT + (spec->flags & SIGN);
2379         } else {
2380                 BUILD_BUG_ON(FORMAT_TYPE_UINT + SIGN != FORMAT_TYPE_INT);
2381                 spec->type = FORMAT_TYPE_UINT + (spec->flags & SIGN);
2382         }
2383
2384         return ++fmt - start;
2385 }
2386
2387 static void
2388 set_field_width(struct printf_spec *spec, int width)
2389 {
2390         spec->field_width = width;
2391         if (WARN_ONCE(spec->field_width != width, "field width %d too large", width)) {
2392                 spec->field_width = clamp(width, -FIELD_WIDTH_MAX, FIELD_WIDTH_MAX);
2393         }
2394 }
2395
2396 static void
2397 set_precision(struct printf_spec *spec, int prec)
2398 {
2399         spec->precision = prec;
2400         if (WARN_ONCE(spec->precision != prec, "precision %d too large", prec)) {
2401                 spec->precision = clamp(prec, 0, PRECISION_MAX);
2402         }
2403 }
2404
2405 /**
2406  * vsnprintf - Format a string and place it in a buffer
2407  * @buf: The buffer to place the result into
2408  * @size: The size of the buffer, including the trailing null space
2409  * @fmt: The format string to use
2410  * @args: Arguments for the format string
2411  *
2412  * This function generally follows C99 vsnprintf, but has some
2413  * extensions and a few limitations:
2414  *
2415  *  - ``%n`` is unsupported
2416  *  - ``%p*`` is handled by pointer()
2417  *
2418  * See pointer() or Documentation/core-api/printk-formats.rst for more
2419  * extensive description.
2420  *
2421  * **Please update the documentation in both places when making changes**
2422  *
2423  * The return value is the number of characters which would
2424  * be generated for the given input, excluding the trailing
2425  * '\0', as per ISO C99. If you want to have the exact
2426  * number of characters written into @buf as return value
2427  * (not including the trailing '\0'), use vscnprintf(). If the
2428  * return is greater than or equal to @size, the resulting
2429  * string is truncated.
2430  *
2431  * If you're not already dealing with a va_list consider using snprintf().
2432  */
2433 int vsnprintf(char *buf, size_t size, const char *fmt, va_list args)
2434 {
2435         unsigned long long num;
2436         char *str, *end;
2437         struct printf_spec spec = {0};
2438
2439         /* Reject out-of-range values early.  Large positive sizes are
2440            used for unknown buffer sizes. */
2441         if (WARN_ON_ONCE(size > INT_MAX))
2442                 return 0;
2443
2444         str = buf;
2445         end = buf + size;
2446
2447         /* Make sure end is always >= buf */
2448         if (end < buf) {
2449                 end = ((void *)-1);
2450                 size = end - buf;
2451         }
2452
2453         while (*fmt) {
2454                 const char *old_fmt = fmt;
2455                 int read = format_decode(fmt, &spec);
2456
2457                 fmt += read;
2458
2459                 switch (spec.type) {
2460                 case FORMAT_TYPE_NONE: {
2461                         int copy = read;
2462                         if (str < end) {
2463                                 if (copy > end - str)
2464                                         copy = end - str;
2465                                 memcpy(str, old_fmt, copy);
2466                         }
2467                         str += read;
2468                         break;
2469                 }
2470
2471                 case FORMAT_TYPE_WIDTH:
2472                         set_field_width(&spec, va_arg(args, int));
2473                         break;
2474
2475                 case FORMAT_TYPE_PRECISION:
2476                         set_precision(&spec, va_arg(args, int));
2477                         break;
2478
2479                 case FORMAT_TYPE_CHAR: {
2480                         char c;
2481
2482                         if (!(spec.flags & LEFT)) {
2483                                 while (--spec.field_width > 0) {
2484                                         if (str < end)
2485                                                 *str = ' ';
2486                                         ++str;
2487
2488                                 }
2489                         }
2490                         c = (unsigned char) va_arg(args, int);
2491                         if (str < end)
2492                                 *str = c;
2493                         ++str;
2494                         while (--spec.field_width > 0) {
2495                                 if (str < end)
2496                                         *str = ' ';
2497                                 ++str;
2498                         }
2499                         break;
2500                 }
2501
2502                 case FORMAT_TYPE_STR:
2503                         str = string(str, end, va_arg(args, char *), spec);
2504                         break;
2505
2506                 case FORMAT_TYPE_PTR:
2507                         str = pointer(fmt, str, end, va_arg(args, void *),
2508                                       spec);
2509                         while (isalnum(*fmt))
2510                                 fmt++;
2511                         break;
2512
2513                 case FORMAT_TYPE_PERCENT_CHAR:
2514                         if (str < end)
2515                                 *str = '%';
2516                         ++str;
2517                         break;
2518
2519                 case FORMAT_TYPE_INVALID:
2520                         /*
2521                          * Presumably the arguments passed gcc's type
2522                          * checking, but there is no safe or sane way
2523                          * for us to continue parsing the format and
2524                          * fetching from the va_list; the remaining
2525                          * specifiers and arguments would be out of
2526                          * sync.
2527                          */
2528                         goto out;
2529
2530                 default:
2531                         switch (spec.type) {
2532                         case FORMAT_TYPE_LONG_LONG:
2533                                 num = va_arg(args, long long);
2534                                 break;
2535                         case FORMAT_TYPE_ULONG:
2536                                 num = va_arg(args, unsigned long);
2537                                 break;
2538                         case FORMAT_TYPE_LONG:
2539                                 num = va_arg(args, long);
2540                                 break;
2541                         case FORMAT_TYPE_SIZE_T:
2542                                 if (spec.flags & SIGN)
2543                                         num = va_arg(args, ssize_t);
2544                                 else
2545                                         num = va_arg(args, size_t);
2546                                 break;
2547                         case FORMAT_TYPE_PTRDIFF:
2548                                 num = va_arg(args, ptrdiff_t);
2549                                 break;
2550                         case FORMAT_TYPE_UBYTE:
2551                                 num = (unsigned char) va_arg(args, int);
2552                                 break;
2553                         case FORMAT_TYPE_BYTE:
2554                                 num = (signed char) va_arg(args, int);
2555                                 break;
2556                         case FORMAT_TYPE_USHORT:
2557                                 num = (unsigned short) va_arg(args, int);
2558                                 break;
2559                         case FORMAT_TYPE_SHORT:
2560                                 num = (short) va_arg(args, int);
2561                                 break;
2562                         case FORMAT_TYPE_INT:
2563                                 num = (int) va_arg(args, int);
2564                                 break;
2565                         default:
2566                                 num = va_arg(args, unsigned int);
2567                         }
2568
2569                         str = number(str, end, num, spec);
2570                 }
2571         }
2572
2573 out:
2574         if (size > 0) {
2575                 if (str < end)
2576                         *str = '\0';
2577                 else
2578                         end[-1] = '\0';
2579         }
2580
2581         /* the trailing null byte doesn't count towards the total */
2582         return str-buf;
2583
2584 }
2585 EXPORT_SYMBOL(vsnprintf);
2586
2587 /**
2588  * vscnprintf - Format a string and place it in a buffer
2589  * @buf: The buffer to place the result into
2590  * @size: The size of the buffer, including the trailing null space
2591  * @fmt: The format string to use
2592  * @args: Arguments for the format string
2593  *
2594  * The return value is the number of characters which have been written into
2595  * the @buf not including the trailing '\0'. If @size is == 0 the function
2596  * returns 0.
2597  *
2598  * If you're not already dealing with a va_list consider using scnprintf().
2599  *
2600  * See the vsnprintf() documentation for format string extensions over C99.
2601  */
2602 int vscnprintf(char *buf, size_t size, const char *fmt, va_list args)
2603 {
2604         int i;
2605
2606         i = vsnprintf(buf, size, fmt, args);
2607
2608         if (likely(i < size))
2609                 return i;
2610         if (size != 0)
2611                 return size - 1;
2612         return 0;
2613 }
2614 EXPORT_SYMBOL(vscnprintf);
2615
2616 /**
2617  * snprintf - Format a string and place it in a buffer
2618  * @buf: The buffer to place the result into
2619  * @size: The size of the buffer, including the trailing null space
2620  * @fmt: The format string to use
2621  * @...: Arguments for the format string
2622  *
2623  * The return value is the number of characters which would be
2624  * generated for the given input, excluding the trailing null,
2625  * as per ISO C99.  If the return is greater than or equal to
2626  * @size, the resulting string is truncated.
2627  *
2628  * See the vsnprintf() documentation for format string extensions over C99.
2629  */
2630 int snprintf(char *buf, size_t size, const char *fmt, ...)
2631 {
2632         va_list args;
2633         int i;
2634
2635         va_start(args, fmt);
2636         i = vsnprintf(buf, size, fmt, args);
2637         va_end(args);
2638
2639         return i;
2640 }
2641 EXPORT_SYMBOL(snprintf);
2642
2643 /**
2644  * scnprintf - Format a string and place it in a buffer
2645  * @buf: The buffer to place the result into
2646  * @size: The size of the buffer, including the trailing null space
2647  * @fmt: The format string to use
2648  * @...: Arguments for the format string
2649  *
2650  * The return value is the number of characters written into @buf not including
2651  * the trailing '\0'. If @size is == 0 the function returns 0.
2652  */
2653
2654 int scnprintf(char *buf, size_t size, const char *fmt, ...)
2655 {
2656         va_list args;
2657         int i;
2658
2659         va_start(args, fmt);
2660         i = vscnprintf(buf, size, fmt, args);
2661         va_end(args);
2662
2663         return i;
2664 }
2665 EXPORT_SYMBOL(scnprintf);
2666
2667 /**
2668  * vsprintf - Format a string and place it in a buffer
2669  * @buf: The buffer to place the result into
2670  * @fmt: The format string to use
2671  * @args: Arguments for the format string
2672  *
2673  * The function returns the number of characters written
2674  * into @buf. Use vsnprintf() or vscnprintf() in order to avoid
2675  * buffer overflows.
2676  *
2677  * If you're not already dealing with a va_list consider using sprintf().
2678  *
2679  * See the vsnprintf() documentation for format string extensions over C99.
2680  */
2681 int vsprintf(char *buf, const char *fmt, va_list args)
2682 {
2683         return vsnprintf(buf, INT_MAX, fmt, args);
2684 }
2685 EXPORT_SYMBOL(vsprintf);
2686
2687 /**
2688  * sprintf - Format a string and place it in a buffer
2689  * @buf: The buffer to place the result into
2690  * @fmt: The format string to use
2691  * @...: Arguments for the format string
2692  *
2693  * The function returns the number of characters written
2694  * into @buf. Use snprintf() or scnprintf() in order to avoid
2695  * buffer overflows.
2696  *
2697  * See the vsnprintf() documentation for format string extensions over C99.
2698  */
2699 int sprintf(char *buf, const char *fmt, ...)
2700 {
2701         va_list args;
2702         int i;
2703
2704         va_start(args, fmt);
2705         i = vsnprintf(buf, INT_MAX, fmt, args);
2706         va_end(args);
2707
2708         return i;
2709 }
2710 EXPORT_SYMBOL(sprintf);
2711
2712 #ifdef CONFIG_BINARY_PRINTF
2713 /*
2714  * bprintf service:
2715  * vbin_printf() - VA arguments to binary data
2716  * bstr_printf() - Binary data to text string
2717  */
2718
2719 /**
2720  * vbin_printf - Parse a format string and place args' binary value in a buffer
2721  * @bin_buf: The buffer to place args' binary value
2722  * @size: The size of the buffer(by words(32bits), not characters)
2723  * @fmt: The format string to use
2724  * @args: Arguments for the format string
2725  *
2726  * The format follows C99 vsnprintf, except %n is ignored, and its argument
2727  * is skipped.
2728  *
2729  * The return value is the number of words(32bits) which would be generated for
2730  * the given input.
2731  *
2732  * NOTE:
2733  * If the return value is greater than @size, the resulting bin_buf is NOT
2734  * valid for bstr_printf().
2735  */
2736 int vbin_printf(u32 *bin_buf, size_t size, const char *fmt, va_list args)
2737 {
2738         struct printf_spec spec = {0};
2739         char *str, *end;
2740         int width;
2741
2742         str = (char *)bin_buf;
2743         end = (char *)(bin_buf + size);
2744
2745 #define save_arg(type)                                                  \
2746 ({                                                                      \
2747         unsigned long long value;                                       \
2748         if (sizeof(type) == 8) {                                        \
2749                 unsigned long long val8;                                \
2750                 str = PTR_ALIGN(str, sizeof(u32));                      \
2751                 val8 = va_arg(args, unsigned long long);                \
2752                 if (str + sizeof(type) <= end) {                        \
2753                         *(u32 *)str = *(u32 *)&val8;                    \
2754                         *(u32 *)(str + 4) = *((u32 *)&val8 + 1);        \
2755                 }                                                       \
2756                 value = val8;                                           \
2757         } else {                                                        \
2758                 unsigned int val4;                                      \
2759                 str = PTR_ALIGN(str, sizeof(type));                     \
2760                 val4 = va_arg(args, int);                               \
2761                 if (str + sizeof(type) <= end)                          \
2762                         *(typeof(type) *)str = (type)(long)val4;        \
2763                 value = (unsigned long long)val4;                       \
2764         }                                                               \
2765         str += sizeof(type);                                            \
2766         value;                                                          \
2767 })
2768
2769         while (*fmt) {
2770                 int read = format_decode(fmt, &spec);
2771
2772                 fmt += read;
2773
2774                 switch (spec.type) {
2775                 case FORMAT_TYPE_NONE:
2776                 case FORMAT_TYPE_PERCENT_CHAR:
2777                         break;
2778                 case FORMAT_TYPE_INVALID:
2779                         goto out;
2780
2781                 case FORMAT_TYPE_WIDTH:
2782                 case FORMAT_TYPE_PRECISION:
2783                         width = (int)save_arg(int);
2784                         /* Pointers may require the width */
2785                         if (*fmt == 'p')
2786                                 set_field_width(&spec, width);
2787                         break;
2788
2789                 case FORMAT_TYPE_CHAR:
2790                         save_arg(char);
2791                         break;
2792
2793                 case FORMAT_TYPE_STR: {
2794                         const char *save_str = va_arg(args, char *);
2795                         const char *err_msg;
2796                         size_t len;
2797
2798                         err_msg = check_pointer_msg(save_str);
2799                         if (err_msg)
2800                                 save_str = err_msg;
2801
2802                         len = strlen(save_str) + 1;
2803                         if (str + len < end)
2804                                 memcpy(str, save_str, len);
2805                         str += len;
2806                         break;
2807                 }
2808
2809                 case FORMAT_TYPE_PTR:
2810                         /* Dereferenced pointers must be done now */
2811                         switch (*fmt) {
2812                         /* Dereference of functions is still OK */
2813                         case 'S':
2814                         case 's':
2815                         case 'F':
2816                         case 'f':
2817                         case 'x':
2818                         case 'K':
2819                                 save_arg(void *);
2820                                 break;
2821                         default:
2822                                 if (!isalnum(*fmt)) {
2823                                         save_arg(void *);
2824                                         break;
2825                                 }
2826                                 str = pointer(fmt, str, end, va_arg(args, void *),
2827                                               spec);
2828                                 if (str + 1 < end)
2829                                         *str++ = '\0';
2830                                 else
2831                                         end[-1] = '\0'; /* Must be nul terminated */
2832                         }
2833                         /* skip all alphanumeric pointer suffixes */
2834                         while (isalnum(*fmt))
2835                                 fmt++;
2836                         break;
2837
2838                 default:
2839                         switch (spec.type) {
2840
2841                         case FORMAT_TYPE_LONG_LONG:
2842                                 save_arg(long long);
2843                                 break;
2844                         case FORMAT_TYPE_ULONG:
2845                         case FORMAT_TYPE_LONG:
2846                                 save_arg(unsigned long);
2847                                 break;
2848                         case FORMAT_TYPE_SIZE_T:
2849                                 save_arg(size_t);
2850                                 break;
2851                         case FORMAT_TYPE_PTRDIFF:
2852                                 save_arg(ptrdiff_t);
2853                                 break;
2854                         case FORMAT_TYPE_UBYTE:
2855                         case FORMAT_TYPE_BYTE:
2856                                 save_arg(char);
2857                                 break;
2858                         case FORMAT_TYPE_USHORT:
2859                         case FORMAT_TYPE_SHORT:
2860                                 save_arg(short);
2861                                 break;
2862                         default:
2863                                 save_arg(int);
2864                         }
2865                 }
2866         }
2867
2868 out:
2869         return (u32 *)(PTR_ALIGN(str, sizeof(u32))) - bin_buf;
2870 #undef save_arg
2871 }
2872 EXPORT_SYMBOL_GPL(vbin_printf);
2873
2874 /**
2875  * bstr_printf - Format a string from binary arguments and place it in a buffer
2876  * @buf: The buffer to place the result into
2877  * @size: The size of the buffer, including the trailing null space
2878  * @fmt: The format string to use
2879  * @bin_buf: Binary arguments for the format string
2880  *
2881  * This function like C99 vsnprintf, but the difference is that vsnprintf gets
2882  * arguments from stack, and bstr_printf gets arguments from @bin_buf which is
2883  * a binary buffer that generated by vbin_printf.
2884  *
2885  * The format follows C99 vsnprintf, but has some extensions:
2886  *  see vsnprintf comment for details.
2887  *
2888  * The return value is the number of characters which would
2889  * be generated for the given input, excluding the trailing
2890  * '\0', as per ISO C99. If you want to have the exact
2891  * number of characters written into @buf as return value
2892  * (not including the trailing '\0'), use vscnprintf(). If the
2893  * return is greater than or equal to @size, the resulting
2894  * string is truncated.
2895  */
2896 int bstr_printf(char *buf, size_t size, const char *fmt, const u32 *bin_buf)
2897 {
2898         struct printf_spec spec = {0};
2899         char *str, *end;
2900         const char *args = (const char *)bin_buf;
2901
2902         if (WARN_ON_ONCE(size > INT_MAX))
2903                 return 0;
2904
2905         str = buf;
2906         end = buf + size;
2907
2908 #define get_arg(type)                                                   \
2909 ({                                                                      \
2910         typeof(type) value;                                             \
2911         if (sizeof(type) == 8) {                                        \
2912                 args = PTR_ALIGN(args, sizeof(u32));                    \
2913                 *(u32 *)&value = *(u32 *)args;                          \
2914                 *((u32 *)&value + 1) = *(u32 *)(args + 4);              \
2915         } else {                                                        \
2916                 args = PTR_ALIGN(args, sizeof(type));                   \
2917                 value = *(typeof(type) *)args;                          \
2918         }                                                               \
2919         args += sizeof(type);                                           \
2920         value;                                                          \
2921 })
2922
2923         /* Make sure end is always >= buf */
2924         if (end < buf) {
2925                 end = ((void *)-1);
2926                 size = end - buf;
2927         }
2928
2929         while (*fmt) {
2930                 const char *old_fmt = fmt;
2931                 int read = format_decode(fmt, &spec);
2932
2933                 fmt += read;
2934
2935                 switch (spec.type) {
2936                 case FORMAT_TYPE_NONE: {
2937                         int copy = read;
2938                         if (str < end) {
2939                                 if (copy > end - str)
2940                                         copy = end - str;
2941                                 memcpy(str, old_fmt, copy);
2942                         }
2943                         str += read;
2944                         break;
2945                 }
2946
2947                 case FORMAT_TYPE_WIDTH:
2948                         set_field_width(&spec, get_arg(int));
2949                         break;
2950
2951                 case FORMAT_TYPE_PRECISION:
2952                         set_precision(&spec, get_arg(int));
2953                         break;
2954
2955                 case FORMAT_TYPE_CHAR: {
2956                         char c;
2957
2958                         if (!(spec.flags & LEFT)) {
2959                                 while (--spec.field_width > 0) {
2960                                         if (str < end)
2961                                                 *str = ' ';
2962                                         ++str;
2963                                 }
2964                         }
2965                         c = (unsigned char) get_arg(char);
2966                         if (str < end)
2967                                 *str = c;
2968                         ++str;
2969                         while (--spec.field_width > 0) {
2970                                 if (str < end)
2971                                         *str = ' ';
2972                                 ++str;
2973                         }
2974                         break;
2975                 }
2976
2977                 case FORMAT_TYPE_STR: {
2978                         const char *str_arg = args;
2979                         args += strlen(str_arg) + 1;
2980                         str = string(str, end, (char *)str_arg, spec);
2981                         break;
2982                 }
2983
2984                 case FORMAT_TYPE_PTR: {
2985                         bool process = false;
2986                         int copy, len;
2987                         /* Non function dereferences were already done */
2988                         switch (*fmt) {
2989                         case 'S':
2990                         case 's':
2991                         case 'F':
2992                         case 'f':
2993                         case 'x':
2994                         case 'K':
2995                                 process = true;
2996                                 break;
2997                         default:
2998                                 if (!isalnum(*fmt)) {
2999                                         process = true;
3000                                         break;
3001                                 }
3002                                 /* Pointer dereference was already processed */
3003                                 if (str < end) {
3004                                         len = copy = strlen(args);
3005                                         if (copy > end - str)
3006                                                 copy = end - str;
3007                                         memcpy(str, args, copy);
3008                                         str += len;
3009                                         args += len + 1;
3010                                 }
3011                         }
3012                         if (process)
3013                                 str = pointer(fmt, str, end, get_arg(void *), spec);
3014
3015                         while (isalnum(*fmt))
3016                                 fmt++;
3017                         break;
3018                 }
3019
3020                 case FORMAT_TYPE_PERCENT_CHAR:
3021                         if (str < end)
3022                                 *str = '%';
3023                         ++str;
3024                         break;
3025
3026                 case FORMAT_TYPE_INVALID:
3027                         goto out;
3028
3029                 default: {
3030                         unsigned long long num;
3031
3032                         switch (spec.type) {
3033
3034                         case FORMAT_TYPE_LONG_LONG:
3035                                 num = get_arg(long long);
3036                                 break;
3037                         case FORMAT_TYPE_ULONG:
3038                         case FORMAT_TYPE_LONG:
3039                                 num = get_arg(unsigned long);
3040                                 break;
3041                         case FORMAT_TYPE_SIZE_T:
3042                                 num = get_arg(size_t);
3043                                 break;
3044                         case FORMAT_TYPE_PTRDIFF:
3045                                 num = get_arg(ptrdiff_t);
3046                                 break;
3047                         case FORMAT_TYPE_UBYTE:
3048                                 num = get_arg(unsigned char);
3049                                 break;
3050                         case FORMAT_TYPE_BYTE:
3051                                 num = get_arg(signed char);
3052                                 break;
3053                         case FORMAT_TYPE_USHORT:
3054                                 num = get_arg(unsigned short);
3055                                 break;
3056                         case FORMAT_TYPE_SHORT:
3057                                 num = get_arg(short);
3058                                 break;
3059                         case FORMAT_TYPE_UINT:
3060                                 num = get_arg(unsigned int);
3061                                 break;
3062                         default:
3063                                 num = get_arg(int);
3064                         }
3065
3066                         str = number(str, end, num, spec);
3067                 } /* default: */
3068                 } /* switch(spec.type) */
3069         } /* while(*fmt) */
3070
3071 out:
3072         if (size > 0) {
3073                 if (str < end)
3074                         *str = '\0';
3075                 else
3076                         end[-1] = '\0';
3077         }
3078
3079 #undef get_arg
3080
3081         /* the trailing null byte doesn't count towards the total */
3082         return str - buf;
3083 }
3084 EXPORT_SYMBOL_GPL(bstr_printf);
3085
3086 /**
3087  * bprintf - Parse a format string and place args' binary value in a buffer
3088  * @bin_buf: The buffer to place args' binary value
3089  * @size: The size of the buffer(by words(32bits), not characters)
3090  * @fmt: The format string to use
3091  * @...: Arguments for the format string
3092  *
3093  * The function returns the number of words(u32) written
3094  * into @bin_buf.
3095  */
3096 int bprintf(u32 *bin_buf, size_t size, const char *fmt, ...)
3097 {
3098         va_list args;
3099         int ret;
3100
3101         va_start(args, fmt);
3102         ret = vbin_printf(bin_buf, size, fmt, args);
3103         va_end(args);
3104
3105         return ret;
3106 }
3107 EXPORT_SYMBOL_GPL(bprintf);
3108
3109 #endif /* CONFIG_BINARY_PRINTF */
3110
3111 /**
3112  * vsscanf - Unformat a buffer into a list of arguments
3113  * @buf:        input buffer
3114  * @fmt:        format of buffer
3115  * @args:       arguments
3116  */
3117 int vsscanf(const char *buf, const char *fmt, va_list args)
3118 {
3119         const char *str = buf;
3120         char *next;
3121         char digit;
3122         int num = 0;
3123         u8 qualifier;
3124         unsigned int base;
3125         union {
3126                 long long s;
3127                 unsigned long long u;
3128         } val;
3129         s16 field_width;
3130         bool is_sign;
3131
3132         while (*fmt) {
3133                 /* skip any white space in format */
3134                 /* white space in format matchs any amount of
3135                  * white space, including none, in the input.
3136                  */
3137                 if (isspace(*fmt)) {
3138                         fmt = skip_spaces(++fmt);
3139                         str = skip_spaces(str);
3140                 }
3141
3142                 /* anything that is not a conversion must match exactly */
3143                 if (*fmt != '%' && *fmt) {
3144                         if (*fmt++ != *str++)
3145                                 break;
3146                         continue;
3147                 }
3148
3149                 if (!*fmt)
3150                         break;
3151                 ++fmt;
3152
3153                 /* skip this conversion.
3154                  * advance both strings to next white space
3155                  */
3156                 if (*fmt == '*') {
3157                         if (!*str)
3158                                 break;
3159                         while (!isspace(*fmt) && *fmt != '%' && *fmt) {
3160                                 /* '%*[' not yet supported, invalid format */
3161                                 if (*fmt == '[')
3162                                         return num;
3163                                 fmt++;
3164                         }
3165                         while (!isspace(*str) && *str)
3166                                 str++;
3167                         continue;
3168                 }
3169
3170                 /* get field width */
3171                 field_width = -1;
3172                 if (isdigit(*fmt)) {
3173                         field_width = skip_atoi(&fmt);
3174                         if (field_width <= 0)
3175                                 break;
3176                 }
3177
3178                 /* get conversion qualifier */
3179                 qualifier = -1;
3180                 if (*fmt == 'h' || _tolower(*fmt) == 'l' ||
3181                     *fmt == 'z') {
3182                         qualifier = *fmt++;
3183                         if (unlikely(qualifier == *fmt)) {
3184                                 if (qualifier == 'h') {
3185                                         qualifier = 'H';
3186                                         fmt++;
3187                                 } else if (qualifier == 'l') {
3188                                         qualifier = 'L';
3189                                         fmt++;
3190                                 }
3191                         }
3192                 }
3193
3194                 if (!*fmt)
3195                         break;
3196
3197                 if (*fmt == 'n') {
3198                         /* return number of characters read so far */
3199                         *va_arg(args, int *) = str - buf;
3200                         ++fmt;
3201                         continue;
3202                 }
3203
3204                 if (!*str)
3205                         break;
3206
3207                 base = 10;
3208                 is_sign = false;
3209
3210                 switch (*fmt++) {
3211                 case 'c':
3212                 {
3213                         char *s = (char *)va_arg(args, char*);
3214                         if (field_width == -1)
3215                                 field_width = 1;
3216                         do {
3217                                 *s++ = *str++;
3218                         } while (--field_width > 0 && *str);
3219                         num++;
3220                 }
3221                 continue;
3222                 case 's':
3223                 {
3224                         char *s = (char *)va_arg(args, char *);
3225                         if (field_width == -1)
3226                                 field_width = SHRT_MAX;
3227                         /* first, skip leading white space in buffer */
3228                         str = skip_spaces(str);
3229
3230                         /* now copy until next white space */
3231                         while (*str && !isspace(*str) && field_width--)
3232                                 *s++ = *str++;
3233                         *s = '\0';
3234                         num++;
3235                 }
3236                 continue;
3237                 /*
3238                  * Warning: This implementation of the '[' conversion specifier
3239                  * deviates from its glibc counterpart in the following ways:
3240                  * (1) It does NOT support ranges i.e. '-' is NOT a special
3241                  *     character
3242                  * (2) It cannot match the closing bracket ']' itself
3243                  * (3) A field width is required
3244                  * (4) '%*[' (discard matching input) is currently not supported
3245                  *
3246                  * Example usage:
3247                  * ret = sscanf("00:0a:95","%2[^:]:%2[^:]:%2[^:]",
3248                  *              buf1, buf2, buf3);
3249                  * if (ret < 3)
3250                  *    // etc..
3251                  */
3252                 case '[':
3253                 {
3254                         char *s = (char *)va_arg(args, char *);
3255                         DECLARE_BITMAP(set, 256) = {0};
3256                         unsigned int len = 0;
3257                         bool negate = (*fmt == '^');
3258
3259                         /* field width is required */
3260                         if (field_width == -1)
3261                                 return num;
3262
3263                         if (negate)
3264                                 ++fmt;
3265
3266                         for ( ; *fmt && *fmt != ']'; ++fmt, ++len)
3267                                 set_bit((u8)*fmt, set);
3268
3269                         /* no ']' or no character set found */
3270                         if (!*fmt || !len)
3271                                 return num;
3272                         ++fmt;
3273
3274                         if (negate) {
3275                                 bitmap_complement(set, set, 256);
3276                                 /* exclude null '\0' byte */
3277                                 clear_bit(0, set);
3278                         }
3279
3280                         /* match must be non-empty */
3281                         if (!test_bit((u8)*str, set))
3282                                 return num;
3283
3284                         while (test_bit((u8)*str, set) && field_width--)
3285                                 *s++ = *str++;
3286                         *s = '\0';
3287                         ++num;
3288                 }
3289                 continue;
3290                 case 'o':
3291                         base = 8;
3292                         break;
3293                 case 'x':
3294                 case 'X':
3295                         base = 16;
3296                         break;
3297                 case 'i':
3298                         base = 0;
3299                         /* fall through */
3300                 case 'd':
3301                         is_sign = true;
3302                         /* fall through */
3303                 case 'u':
3304                         break;
3305                 case '%':
3306                         /* looking for '%' in str */
3307                         if (*str++ != '%')
3308                                 return num;
3309                         continue;
3310                 default:
3311                         /* invalid format; stop here */
3312                         return num;
3313                 }
3314
3315                 /* have some sort of integer conversion.
3316                  * first, skip white space in buffer.
3317                  */
3318                 str = skip_spaces(str);
3319
3320                 digit = *str;
3321                 if (is_sign && digit == '-')
3322                         digit = *(str + 1);
3323
3324                 if (!digit
3325                     || (base == 16 && !isxdigit(digit))
3326                     || (base == 10 && !isdigit(digit))
3327                     || (base == 8 && (!isdigit(digit) || digit > '7'))
3328                     || (base == 0 && !isdigit(digit)))
3329                         break;
3330
3331                 if (is_sign)
3332                         val.s = qualifier != 'L' ?
3333                                 simple_strtol(str, &next, base) :
3334                                 simple_strtoll(str, &next, base);
3335                 else
3336                         val.u = qualifier != 'L' ?
3337                                 simple_strtoul(str, &next, base) :
3338                                 simple_strtoull(str, &next, base);
3339
3340                 if (field_width > 0 && next - str > field_width) {
3341                         if (base == 0)
3342                                 _parse_integer_fixup_radix(str, &base);
3343                         while (next - str > field_width) {
3344                                 if (is_sign)
3345                                         val.s = div_s64(val.s, base);
3346                                 else
3347                                         val.u = div_u64(val.u, base);
3348                                 --next;
3349                         }
3350                 }
3351
3352                 switch (qualifier) {
3353                 case 'H':       /* that's 'hh' in format */
3354                         if (is_sign)
3355                                 *va_arg(args, signed char *) = val.s;
3356                         else
3357                                 *va_arg(args, unsigned char *) = val.u;
3358                         break;
3359                 case 'h':
3360                         if (is_sign)
3361                                 *va_arg(args, short *) = val.s;
3362                         else
3363                                 *va_arg(args, unsigned short *) = val.u;
3364                         break;
3365                 case 'l':
3366                         if (is_sign)
3367                                 *va_arg(args, long *) = val.s;
3368                         else
3369                                 *va_arg(args, unsigned long *) = val.u;
3370                         break;
3371                 case 'L':
3372                         if (is_sign)
3373                                 *va_arg(args, long long *) = val.s;
3374                         else
3375                                 *va_arg(args, unsigned long long *) = val.u;
3376                         break;
3377                 case 'z':
3378                         *va_arg(args, size_t *) = val.u;
3379                         break;
3380                 default:
3381                         if (is_sign)
3382                                 *va_arg(args, int *) = val.s;
3383                         else
3384                                 *va_arg(args, unsigned int *) = val.u;
3385                         break;
3386                 }
3387                 num++;
3388
3389                 if (!next)
3390                         break;
3391                 str = next;
3392         }
3393
3394         return num;
3395 }
3396 EXPORT_SYMBOL(vsscanf);
3397
3398 /**
3399  * sscanf - Unformat a buffer into a list of arguments
3400  * @buf:        input buffer
3401  * @fmt:        formatting of buffer
3402  * @...:        resulting arguments
3403  */
3404 int sscanf(const char *buf, const char *fmt, ...)
3405 {
3406         va_list args;
3407         int i;
3408
3409         va_start(args, fmt);
3410         i = vsscanf(buf, fmt, args);
3411         va_end(args);
3412
3413         return i;
3414 }
3415 EXPORT_SYMBOL(sscanf);