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/errname.h>
  25 #include <linux/module.h>       /* for KSYM_SYMBOL_LEN */
  26 #include <linux/types.h>
  27 #include <linux/string.h>
  28 #include <linux/ctype.h>
  29 #include <linux/kernel.h>
  30 #include <linux/kallsyms.h>
  31 #include <linux/math64.h>
  32 #include <linux/uaccess.h>
  33 #include <linux/ioport.h>
  34 #include <linux/dcache.h>
  35 #include <linux/cred.h>
  36 #include <linux/rtc.h>
  37 #include <linux/uuid.h>
  38 #include <linux/of.h>
  39 #include <net/addrconf.h>
  40 #include <linux/siphash.h>
  41 #include <linux/compiler.h>
  42 #include <linux/property.h>
  43 #ifdef CONFIG_BLOCK
  44 #include <linux/blkdev.h>
  45 #endif
  46
  47 #include "../mm/internal.h"     /* For the trace_print_flags arrays */
  48
  49 #include <asm/page.h>           /* for PAGE_SIZE */
  50 #include <asm/byteorder.h>      /* cpu_to_le16 */
  51
  52 #include <linux/string_helpers.h>
  53 #include "kstrtox.h"
  54
  55 /**
  56  * simple_strtoull - convert a string to an unsigned long long
  57  * @cp: The start of the string
  58  * @endp: A pointer to the end of the parsed string will be placed here
  59  * @base: The number base to use
  60  *
  61  * This function is obsolete. Please use kstrtoull instead.
  62  */
  63 unsigned long long simple_strtoull(const char *cp, char **endp, unsigned int base)
  64 {
  65         unsigned long long result;
  66         unsigned int rv;
  67
  68         cp = _parse_integer_fixup_radix(cp, &base);
  69         rv = _parse_integer(cp, base, &result);
  70         /* FIXME */
  71         cp += (rv & ~KSTRTOX_OVERFLOW);
  72
  73         if (endp)
  74                 *endp = (char *)cp;
  75
  76         return result;
  77 }
  78 EXPORT_SYMBOL(simple_strtoull);
  79
  80 /**
  81  * simple_strtoul - convert a string to an unsigned long
  82  * @cp: The start of the string
  83  * @endp: A pointer to the end of the parsed string will be placed here
  84  * @base: The number base to use
  85  *
  86  * This function is obsolete. Please use kstrtoul instead.
  87  */
  88 unsigned long simple_strtoul(const char *cp, char **endp, unsigned int base)
  89 {
  90         return simple_strtoull(cp, endp, base);
  91 }
  92 EXPORT_SYMBOL(simple_strtoul);
  93
  94 /**
  95  * simple_strtol - convert a string to a signed long
  96  * @cp: The start of the string
  97  * @endp: A pointer to the end of the parsed string will be placed here
  98  * @base: The number base to use
  99  *
 100  * This function is obsolete. Please use kstrtol instead.
 101  */
 102 long simple_strtol(const char *cp, char **endp, unsigned int base)
 103 {
 104         if (*cp == '-')
 105                 return -simple_strtoul(cp + 1, endp, base);
 106
 107         return simple_strtoul(cp, endp, base);
 108 }
 109 EXPORT_SYMBOL(simple_strtol);
 110
 111 /**
 112  * simple_strtoll - convert a string to a signed long long
 113  * @cp: The start of the string
 114  * @endp: A pointer to the end of the parsed string will be placed here
 115  * @base: The number base to use
 116  *
 117  * This function is obsolete. Please use kstrtoll instead.
 118  */
 119 long long simple_strtoll(const char *cp, char **endp, unsigned int base)
 120 {
 121         if (*cp == '-')
 122                 return -simple_strtoull(cp + 1, endp, base);
 123
 124         return simple_strtoull(cp, endp, base);
 125 }
 126 EXPORT_SYMBOL(simple_strtoll);
 127
 128 static noinline_for_stack
 129 int skip_atoi(const char **s)
 130 {
 131         int i = 0;
 132
 133         do {
 134                 i = i*10 + *((*s)++) - '0';
 135         } while (isdigit(**s));
 136
 137         return i;
 138 }
 139
 140 /*
 141  * Decimal conversion is by far the most typical, and is used for
 142  * /proc and /sys data. This directly impacts e.g. top performance
 143  * with many processes running. We optimize it for speed by emitting
 144  * two characters at a time, using a 200 byte lookup table. This
 145  * roughly halves the number of multiplications compared to computing
 146  * the digits one at a time. Implementation strongly inspired by the
 147  * previous version, which in turn used ideas described at
 148  * <http://www.cs.uiowa.edu/~jones/bcd/divide.html> (with permission
 149  * from the author, Douglas W. Jones).
 150  *
 151  * It turns out there is precisely one 26 bit fixed-point
 152  * approximation a of 64/100 for which x/100 == (x * (u64)a) >> 32
 153  * holds for all x in [0, 10^8-1], namely a = 0x28f5c29. The actual
 154  * range happens to be somewhat larger (x <= 1073741898), but that's
 155  * irrelevant for our purpose.
 156  *
 157  * For dividing a number in the range [10^4, 10^6-1] by 100, we still
 158  * need a 32x32->64 bit multiply, so we simply use the same constant.
 159  *
 160  * For dividing a number in the range [100, 10^4-1] by 100, there are
 161  * several options. The simplest is (x * 0x147b) >> 19, which is valid
 162  * for all x <= 43698.
 163  */
 164
 165 static const u16 decpair[100] = {
 166 #define _(x) (__force u16) cpu_to_le16(((x % 10) | ((x / 10) << 8)) + 0x3030)
 167         _( 0), _( 1), _( 2), _( 3), _( 4), _( 5), _( 6), _( 7), _( 8), _( 9),
 168         _(10), _(11), _(12), _(13), _(14), _(15), _(16), _(17), _(18), _(19),
 169         _(20), _(21), _(22), _(23), _(24), _(25), _(26), _(27), _(28), _(29),
 170         _(30), _(31), _(32), _(33), _(34), _(35), _(36), _(37), _(38), _(39),
 171         _(40), _(41), _(42), _(43), _(44), _(45), _(46), _(47), _(48), _(49),
 172         _(50), _(51), _(52), _(53), _(54), _(55), _(56), _(57), _(58), _(59),
 173         _(60), _(61), _(62), _(63), _(64), _(65), _(66), _(67), _(68), _(69),
 174         _(70), _(71), _(72), _(73), _(74), _(75), _(76), _(77), _(78), _(79),
 175         _(80), _(81), _(82), _(83), _(84), _(85), _(86), _(87), _(88), _(89),
 176         _(90), _(91), _(92), _(93), _(94), _(95), _(96), _(97), _(98), _(99),
 177 #undef _
 178 };
 179
 180 /*
 181  * This will print a single '0' even if r == 0, since we would
 182  * immediately jump to out_r where two 0s would be written but only
 183  * one of them accounted for in buf. This is needed by ip4_string
 184  * below. All other callers pass a non-zero value of r.
 185 */
 186 static noinline_for_stack
 187 char *put_dec_trunc8(char *buf, unsigned r)
 188 {
 189         unsigned q;
 190
 191         /* 1 <= r < 10^8 */
 192         if (r < 100)
 193                 goto out_r;
 194
 195         /* 100 <= r < 10^8 */
 196         q = (r * (u64)0x28f5c29) >> 32;
 197         *((u16 *)buf) = decpair[r - 100*q];
 198         buf += 2;
 199
 200         /* 1 <= q < 10^6 */
 201         if (q < 100)
 202                 goto out_q;
 203
 204         /*  100 <= q < 10^6 */
 205         r = (q * (u64)0x28f5c29) >> 32;
 206         *((u16 *)buf) = decpair[q - 100*r];
 207         buf += 2;
 208
 209         /* 1 <= r < 10^4 */
 210         if (r < 100)
 211                 goto out_r;
 212
 213         /* 100 <= r < 10^4 */
 214         q = (r * 0x147b) >> 19;
 215         *((u16 *)buf) = decpair[r - 100*q];
 216         buf += 2;
 217 out_q:
 218         /* 1 <= q < 100 */
 219         r = q;
 220 out_r:
 221         /* 1 <= r < 100 */
 222         *((u16 *)buf) = decpair[r];
 223         buf += r < 10 ? 1 : 2;
 224         return buf;
 225 }
 226
 227 #if BITS_PER_LONG == 64 && BITS_PER_LONG_LONG == 64
 228 static noinline_for_stack
 229 char *put_dec_full8(char *buf, unsigned r)
 230 {
 231         unsigned q;
 232
 233         /* 0 <= r < 10^8 */
 234         q = (r * (u64)0x28f5c29) >> 32;
 235         *((u16 *)buf) = decpair[r - 100*q];
 236         buf += 2;
 237
 238         /* 0 <= q < 10^6 */
 239         r = (q * (u64)0x28f5c29) >> 32;
 240         *((u16 *)buf) = decpair[q - 100*r];
 241         buf += 2;
 242
 243         /* 0 <= r < 10^4 */
 244         q = (r * 0x147b) >> 19;
 245         *((u16 *)buf) = decpair[r - 100*q];
 246         buf += 2;
 247
 248         /* 0 <= q < 100 */
 249         *((u16 *)buf) = decpair[q];
 250         buf += 2;
 251         return buf;
 252 }
 253
 254 static noinline_for_stack
 255 char *put_dec(char *buf, unsigned long long n)
 256 {
 257         if (n >= 100*1000*1000)
 258                 buf = put_dec_full8(buf, do_div(n, 100*1000*1000));
 259         /* 1 <= n <= 1.6e11 */
 260         if (n >= 100*1000*1000)
 261                 buf = put_dec_full8(buf, do_div(n, 100*1000*1000));
 262         /* 1 <= n < 1e8 */
 263         return put_dec_trunc8(buf, n);
 264 }
 265
 266 #elif BITS_PER_LONG == 32 && BITS_PER_LONG_LONG == 64
 267
 268 static void
 269 put_dec_full4(char *buf, unsigned r)
 270 {
 271         unsigned q;
 272
 273         /* 0 <= r < 10^4 */
 274         q = (r * 0x147b) >> 19;
 275         *((u16 *)buf) = decpair[r - 100*q];
 276         buf += 2;
 277         /* 0 <= q < 100 */
 278         *((u16 *)buf) = decpair[q];
 279 }
 280
 281 /*
 282  * Call put_dec_full4 on x % 10000, return x / 10000.
 283  * The approximation x/10000 == (x * 0x346DC5D7) >> 43
 284  * holds for all x < 1,128,869,999.  The largest value this
 285  * helper will ever be asked to convert is 1,125,520,955.
 286  * (second call in the put_dec code, assuming n is all-ones).
 287  */
 288 static noinline_for_stack
 289 unsigned put_dec_helper4(char *buf, unsigned x)
 290 {
 291         uint32_t q = (x * (uint64_t)0x346DC5D7) >> 43;
 292
 293         put_dec_full4(buf, x - q * 10000);
 294         return q;
 295 }
 296
 297 /* Based on code by Douglas W. Jones found at
 298  * <http://www.cs.uiowa.edu/~jones/bcd/decimal.html#sixtyfour>
 299  * (with permission from the author).
 300  * Performs no 64-bit division and hence should be fast on 32-bit machines.
 301  */
 302 static
 303 char *put_dec(char *buf, unsigned long long n)
 304 {
 305         uint32_t d3, d2, d1, q, h;
 306
 307         if (n < 100*1000*1000)
 308                 return put_dec_trunc8(buf, n);
 309
 310         d1  = ((uint32_t)n >> 16); /* implicit "& 0xffff" */
 311         h   = (n >> 32);
 312         d2  = (h      ) & 0xffff;
 313         d3  = (h >> 16); /* implicit "& 0xffff" */
 314
 315         /* n = 2^48 d3 + 2^32 d2 + 2^16 d1 + d0
 316              = 281_4749_7671_0656 d3 + 42_9496_7296 d2 + 6_5536 d1 + d0 */
 317         q   = 656 * d3 + 7296 * d2 + 5536 * d1 + ((uint32_t)n & 0xffff);
 318         q = put_dec_helper4(buf, q);
 319
 320         q += 7671 * d3 + 9496 * d2 + 6 * d1;
 321         q = put_dec_helper4(buf+4, q);
 322
 323         q += 4749 * d3 + 42 * d2;
 324         q = put_dec_helper4(buf+8, q);
 325
 326         q += 281 * d3;
 327         buf += 12;
 328         if (q)
 329                 buf = put_dec_trunc8(buf, q);
 330         else while (buf[-1] == '0')
 331                 --buf;
 332
 333         return buf;
 334 }
 335
 336 #endif
 337
 338 /*
 339  * Convert passed number to decimal string.
 340  * Returns the length of string.  On buffer overflow, returns 0.
 341  *
 342  * If speed is not important, use snprintf(). It's easy to read the code.
 343  */
 344 int num_to_str(char *buf, int size, unsigned long long num, unsigned int width)
 345 {
 346         /* put_dec requires 2-byte alignment of the buffer. */
 347         char tmp[sizeof(num) * 3] __aligned(2);
 348         int idx, len;
 349
 350         /* put_dec() may work incorrectly for num = 0 (generate "", not "0") */
 351         if (num <= 9) {
 352                 tmp[0] = '0' + num;
 353                 len = 1;
 354         } else {
 355                 len = put_dec(tmp, num) - tmp;
 356         }
 357
 358         if (len > size || width > size)
 359                 return 0;
 360
 361         if (width > len) {
 362                 width = width - len;
 363                 for (idx = 0; idx < width; idx++)
 364                         buf[idx] = ' ';
 365         } else {
 366                 width = 0;
 367         }
 368
 369         for (idx = 0; idx < len; ++idx)
 370                 buf[idx + width] = tmp[len - idx - 1];
 371
 372         return len + width;
 373 }
 374
 375 #define SIGN    1               /* unsigned/signed, must be 1 */
 376 #define LEFT    2               /* left justified */
 377 #define PLUS    4               /* show plus */
 378 #define SPACE   8               /* space if plus */
 379 #define ZEROPAD 16              /* pad with zero, must be 16 == '0' - ' ' */
 380 #define SMALL   32              /* use lowercase in hex (must be 32 == 0x20) */
 381 #define SPECIAL 64              /* prefix hex with "0x", octal with "0" */
 382
 383 enum format_type {
 384         FORMAT_TYPE_NONE, /* Just a string part */
 385         FORMAT_TYPE_WIDTH,
 386         FORMAT_TYPE_PRECISION,
 387         FORMAT_TYPE_CHAR,
 388         FORMAT_TYPE_STR,
 389         FORMAT_TYPE_PTR,
 390         FORMAT_TYPE_PERCENT_CHAR,
 391         FORMAT_TYPE_INVALID,
 392         FORMAT_TYPE_LONG_LONG,
 393         FORMAT_TYPE_ULONG,
 394         FORMAT_TYPE_LONG,
 395         FORMAT_TYPE_UBYTE,
 396         FORMAT_TYPE_BYTE,
 397         FORMAT_TYPE_USHORT,
 398         FORMAT_TYPE_SHORT,
 399         FORMAT_TYPE_UINT,
 400         FORMAT_TYPE_INT,
 401         FORMAT_TYPE_SIZE_T,
 402         FORMAT_TYPE_PTRDIFF
 403 };
 404
 405 struct printf_spec {
 406         unsigned int    type:8;         /* format_type enum */
 407         signed int      field_width:24; /* width of output field */
 408         unsigned int    flags:8;        /* flags to number() */
 409         unsigned int    base:8;         /* number base, 8, 10 or 16 only */
 410         signed int      precision:16;   /* # of digits/chars */
 411 } __packed;
 412 static_assert(sizeof(struct printf_spec) == 8);
 413
 414 #define FIELD_WIDTH_MAX ((1 << 23) - 1)
 415 #define PRECISION_MAX ((1 << 15) - 1)
 416
 417 static noinline_for_stack
 418 char *number(char *buf, char *end, unsigned long long num,
 419              struct printf_spec spec)
 420 {
 421         /* put_dec requires 2-byte alignment of the buffer. */
 422         char tmp[3 * sizeof(num)] __aligned(2);
 423         char sign;
 424         char locase;
 425         int need_pfx = ((spec.flags & SPECIAL) && spec.base != 10);
 426         int i;
 427         bool is_zero = num == 0LL;
 428         int field_width = spec.field_width;
 429         int precision = spec.precision;
 430
 431         /* locase = 0 or 0x20. ORing digits or letters with 'locase'
 432          * produces same digits or (maybe lowercased) letters */
 433         locase = (spec.flags & SMALL);
 434         if (spec.flags & LEFT)
 435                 spec.flags &= ~ZEROPAD;
 436         sign = 0;
 437         if (spec.flags & SIGN) {
 438                 if ((signed long long)num < 0) {
 439                         sign = '-';
 440                         num = -(signed long long)num;
 441                         field_width--;
 442                 } else if (spec.flags & PLUS) {
 443                         sign = '+';
 444                         field_width--;
 445                 } else if (spec.flags & SPACE) {
 446                         sign = ' ';
 447                         field_width--;
 448                 }
 449         }
 450         if (need_pfx) {
 451                 if (spec.base == 16)
 452                         field_width -= 2;
 453                 else if (!is_zero)
 454                         field_width--;
 455         }
 456
 457         /* generate full string in tmp[], in reverse order */
 458         i = 0;
 459         if (num < spec.base)
 460                 tmp[i++] = hex_asc_upper[num] | locase;
 461         else if (spec.base != 10) { /* 8 or 16 */
 462                 int mask = spec.base - 1;
 463                 int shift = 3;
 464
 465                 if (spec.base == 16)
 466                         shift = 4;
 467                 do {
 468                         tmp[i++] = (hex_asc_upper[((unsigned char)num) & mask] | locase);
 469                         num >>= shift;
 470                 } while (num);
 471         } else { /* base 10 */
 472                 i = put_dec(tmp, num) - tmp;
 473         }
 474
 475         /* printing 100 using %2d gives "100", not "00" */
 476         if (i > precision)
 477                 precision = i;
 478         /* leading space padding */
 479         field_width -= precision;
 480         if (!(spec.flags & (ZEROPAD | LEFT))) {
 481                 while (--field_width >= 0) {
 482                         if (buf < end)
 483                                 *buf = ' ';
 484                         ++buf;
 485                 }
 486         }
 487         /* sign */
 488         if (sign) {
 489                 if (buf < end)
 490                         *buf = sign;
 491                 ++buf;
 492         }
 493         /* "0x" / "0" prefix */
 494         if (need_pfx) {
 495                 if (spec.base == 16 || !is_zero) {
 496                         if (buf < end)
 497                                 *buf = '0';
 498                         ++buf;
 499                 }
 500                 if (spec.base == 16) {
 501                         if (buf < end)
 502                                 *buf = ('X' | locase);
 503                         ++buf;
 504                 }
 505         }
 506         /* zero or space padding */
 507         if (!(spec.flags & LEFT)) {
 508                 char c = ' ' + (spec.flags & ZEROPAD);
 509                 BUILD_BUG_ON(' ' + ZEROPAD != '0');
 510                 while (--field_width >= 0) {
 511                         if (buf < end)
 512                                 *buf = c;
 513                         ++buf;
 514                 }
 515         }
 516         /* hmm even more zero padding? */
 517         while (i <= --precision) {
 518                 if (buf < end)
 519                         *buf = '0';
 520                 ++buf;
 521         }
 522         /* actual digits of result */
 523         while (--i >= 0) {
 524                 if (buf < end)
 525                         *buf = tmp[i];
 526                 ++buf;
 527         }
 528         /* trailing space padding */
 529         while (--field_width >= 0) {
 530                 if (buf < end)
 531                         *buf = ' ';
 532                 ++buf;
 533         }
 534
 535         return buf;
 536 }
 537
 538 static noinline_for_stack
 539 char *special_hex_number(char *buf, char *end, unsigned long long num, int size)
 540 {
 541         struct printf_spec spec;
 542
 543         spec.type = FORMAT_TYPE_PTR;
 544         spec.field_width = 2 + 2 * size;        /* 0x + hex */
 545         spec.flags = SPECIAL | SMALL | ZEROPAD;
 546         spec.base = 16;
 547         spec.precision = -1;
 548
 549         return number(buf, end, num, spec);
 550 }
 551
 552 static void move_right(char *buf, char *end, unsigned len, unsigned spaces)
 553 {
 554         size_t size;
 555         if (buf >= end) /* nowhere to put anything */
 556                 return;
 557         size = end - buf;
 558         if (size <= spaces) {
 559                 memset(buf, ' ', size);
 560                 return;
 561         }
 562         if (len) {
 563                 if (len > size - spaces)
 564                         len = size - spaces;
 565                 memmove(buf + spaces, buf, len);
 566         }
 567         memset(buf, ' ', spaces);
 568 }
 569
 570 /*
 571  * Handle field width padding for a string.
 572  * @buf: current buffer position
 573  * @n: length of string
 574  * @end: end of output buffer
 575  * @spec: for field width and flags
 576  * Returns: new buffer position after padding.
 577  */
 578 static noinline_for_stack
 579 char *widen_string(char *buf, int n, char *end, struct printf_spec spec)
 580 {
 581         unsigned spaces;
 582
 583         if (likely(n >= spec.field_width))
 584                 return buf;
 585         /* we want to pad the sucker */
 586         spaces = spec.field_width - n;
 587         if (!(spec.flags & LEFT)) {
 588                 move_right(buf - n, end, n, spaces);
 589                 return buf + spaces;
 590         }
 591         while (spaces--) {
 592                 if (buf < end)
 593                         *buf = ' ';
 594                 ++buf;
 595         }
 596         return buf;
 597 }
 598
 599 /* Handle string from a well known address. */
 600 static char *string_nocheck(char *buf, char *end, const char *s,
 601                             struct printf_spec spec)
 602 {
 603         int len = 0;
 604         int lim = spec.precision;
 605
 606         while (lim--) {
 607                 char c = *s++;
 608                 if (!c)
 609                         break;
 610                 if (buf < end)
 611                         *buf = c;
 612                 ++buf;
 613                 ++len;
 614         }
 615         return widen_string(buf, len, end, spec);
 616 }
 617
 618 static char *err_ptr(char *buf, char *end, void *ptr,
 619                      struct printf_spec spec)
 620 {
 621         int err = PTR_ERR(ptr);
 622         const char *sym = errname(err);
 623
 624         if (sym)
 625                 return string_nocheck(buf, end, sym, spec);
 626
 627         /*
 628          * Somebody passed ERR_PTR(-1234) or some other non-existing
 629          * Efoo - or perhaps CONFIG_SYMBOLIC_ERRNAME=n. Fall back to
 630          * printing it as its decimal representation.
 631          */
 632         spec.flags |= SIGN;
 633         spec.base = 10;
 634         return number(buf, end, err, spec);
 635 }
 636
 637 /* Be careful: error messages must fit into the given buffer. */
 638 static char *error_string(char *buf, char *end, const char *s,
 639                           struct printf_spec spec)
 640 {
 641         /*
 642          * Hard limit to avoid a completely insane messages. It actually
 643          * works pretty well because most error messages are in
 644          * the many pointer format modifiers.
 645          */
 646         if (spec.precision == -1)
 647                 spec.precision = 2 * sizeof(void *);
 648
 649         return string_nocheck(buf, end, s, spec);
 650 }
 651
 652 /*
 653  * Do not call any complex external code here. Nested printk()/vsprintf()
 654  * might cause infinite loops. Failures might break printk() and would
 655  * be hard to debug.
 656  */
 657 static const char *check_pointer_msg(const void *ptr)
 658 {
 659         if (!ptr)
 660                 return "(null)";
 661
 662         if ((unsigned long)ptr < PAGE_SIZE || IS_ERR_VALUE(ptr))
 663                 return "(efault)";
 664
 665         return NULL;
 666 }
 667
 668 static int check_pointer(char **buf, char *end, const void *ptr,
 669                          struct printf_spec spec)
 670 {
 671         const char *err_msg;
 672
 673         err_msg = check_pointer_msg(ptr);
 674         if (err_msg) {
 675                 *buf = error_string(*buf, end, err_msg, spec);
 676                 return -EFAULT;
 677         }
 678
 679         return 0;
 680 }
 681
 682 static noinline_for_stack
 683 char *string(char *buf, char *end, const char *s,
 684              struct printf_spec spec)
 685 {
 686         if (check_pointer(&buf, end, s, spec))
 687                 return buf;
 688
 689         return string_nocheck(buf, end, s, spec);
 690 }
 691
 692 static char *pointer_string(char *buf, char *end,
 693                             const void *ptr,
 694                             struct printf_spec spec)
 695 {
 696         spec.base = 16;
 697         spec.flags |= SMALL;
 698         if (spec.field_width == -1) {
 699                 spec.field_width = 2 * sizeof(ptr);
 700                 spec.flags |= ZEROPAD;
 701         }
 702
 703         return number(buf, end, (unsigned long int)ptr, spec);
 704 }
 705
 706 /* Make pointers available for printing early in the boot sequence. */
 707 static int debug_boot_weak_hash __ro_after_init;
 708
 709 static int __init debug_boot_weak_hash_enable(char *str)
 710 {
 711         debug_boot_weak_hash = 1;
 712         pr_info("debug_boot_weak_hash enabled\n");
 713         return 0;
 714 }
 715 early_param("debug_boot_weak_hash", debug_boot_weak_hash_enable);
 716
 717 static DEFINE_STATIC_KEY_TRUE(not_filled_random_ptr_key);
 718 static siphash_key_t ptr_key __read_mostly;
 719
 720 static void enable_ptr_key_workfn(struct work_struct *work)
 721 {
 722         get_random_bytes(&ptr_key, sizeof(ptr_key));
 723         /* Needs to run from preemptible context */
 724         static_branch_disable(&not_filled_random_ptr_key);
 725 }
 726
 727 static DECLARE_WORK(enable_ptr_key_work, enable_ptr_key_workfn);
 728
 729 static void fill_random_ptr_key(struct random_ready_callback *unused)
 730 {
 731         /* This may be in an interrupt handler. */
 732         queue_work(system_unbound_wq, &enable_ptr_key_work);
 733 }
 734
 735 static struct random_ready_callback random_ready = {
 736         .func = fill_random_ptr_key
 737 };
 738
 739 static int __init initialize_ptr_random(void)
 740 {
 741         int key_size = sizeof(ptr_key);
 742         int ret;
 743
 744         /* Use hw RNG if available. */
 745         if (get_random_bytes_arch(&ptr_key, key_size) == key_size) {
 746                 static_branch_disable(&not_filled_random_ptr_key);
 747                 return 0;
 748         }
 749
 750         ret = add_random_ready_callback(&random_ready);
 751         if (!ret) {
 752                 return 0;
 753         } else if (ret == -EALREADY) {
 754                 /* This is in preemptible context */
 755                 enable_ptr_key_workfn(&enable_ptr_key_work);
 756                 return 0;
 757         }
 758
 759         return ret;
 760 }
 761 early_initcall(initialize_ptr_random);
 762
 763 /* Maps a pointer to a 32 bit unique identifier. */
 764 static inline int __ptr_to_hashval(const void *ptr, unsigned long *hashval_out)
 765 {
 766         unsigned long hashval;
 767
 768         if (static_branch_unlikely(&not_filled_random_ptr_key))
 769                 return -EAGAIN;
 770
 771 #ifdef CONFIG_64BIT
 772         hashval = (unsigned long)siphash_1u64((u64)ptr, &ptr_key);
 773         /*
 774          * Mask off the first 32 bits, this makes explicit that we have
 775          * modified the address (and 32 bits is plenty for a unique ID).
 776          */
 777         hashval = hashval & 0xffffffff;
 778 #else
 779         hashval = (unsigned long)siphash_1u32((u32)ptr, &ptr_key);
 780 #endif
 781         *hashval_out = hashval;
 782         return 0;
 783 }
 784
 785 int ptr_to_hashval(const void *ptr, unsigned long *hashval_out)
 786 {
 787         return __ptr_to_hashval(ptr, hashval_out);
 788 }
 789
 790 static char *ptr_to_id(char *buf, char *end, const void *ptr,
 791                        struct printf_spec spec)
 792 {
 793         const char *str = sizeof(ptr) == 8 ? "(____ptrval____)" : "(ptrval)";
 794         unsigned long hashval;
 795         int ret;
 796
 797         /*
 798          * Print the real pointer value for NULL and error pointers,
 799          * as they are not actual addresses.
 800          */
 801         if (IS_ERR_OR_NULL(ptr))
 802                 return pointer_string(buf, end, ptr, spec);
 803
 804         /* When debugging early boot use non-cryptographically secure hash. */
 805         if (unlikely(debug_boot_weak_hash)) {
 806                 hashval = hash_long((unsigned long)ptr, 32);
 807                 return pointer_string(buf, end, (const void *)hashval, spec);
 808         }
 809
 810         ret = __ptr_to_hashval(ptr, &hashval);
 811         if (ret) {
 812                 spec.field_width = 2 * sizeof(ptr);
 813                 /* string length must be less than default_width */
 814                 return error_string(buf, end, str, spec);
 815         }
 816
 817         return pointer_string(buf, end, (const void *)hashval, spec);
 818 }
 819
 820 int kptr_restrict __read_mostly;
 821
 822 static noinline_for_stack
 823 char *restricted_pointer(char *buf, char *end, const void *ptr,
 824                          struct printf_spec spec)
 825 {
 826         switch (kptr_restrict) {
 827         case 0:
 828                 /* Handle as %p, hash and do _not_ leak addresses. */
 829                 return ptr_to_id(buf, end, ptr, spec);
 830         case 1: {
 831                 const struct cred *cred;
 832
 833                 /*
 834                  * kptr_restrict==1 cannot be used in IRQ context
 835                  * because its test for CAP_SYSLOG would be meaningless.
 836                  */
 837                 if (in_irq() || in_serving_softirq() || in_nmi()) {
 838                         if (spec.field_width == -1)
 839                                 spec.field_width = 2 * sizeof(ptr);
 840                         return error_string(buf, end, "pK-error", spec);
 841                 }
 842
 843                 /*
 844                  * Only print the real pointer value if the current
 845                  * process has CAP_SYSLOG and is running with the
 846                  * same credentials it started with. This is because
 847                  * access to files is checked at open() time, but %pK
 848                  * checks permission at read() time. We don't want to
 849                  * leak pointer values if a binary opens a file using
 850                  * %pK and then elevates privileges before reading it.
 851                  */
 852                 cred = current_cred();
 853                 if (!has_capability_noaudit(current, CAP_SYSLOG) ||
 854                     !uid_eq(cred->euid, cred->uid) ||
 855                     !gid_eq(cred->egid, cred->gid))
 856                         ptr = NULL;
 857                 break;
 858         }
 859         case 2:
 860         default:
 861                 /* Always print 0's for %pK */
 862                 ptr = NULL;
 863                 break;
 864         }
 865
 866         return pointer_string(buf, end, ptr, spec);
 867 }
 868
 869 static noinline_for_stack
 870 char *dentry_name(char *buf, char *end, const struct dentry *d, struct printf_spec spec,
 871                   const char *fmt)
 872 {
 873         const char *array[4], *s;
 874         const struct dentry *p;
 875         int depth;
 876         int i, n;
 877
 878         switch (fmt[1]) {
 879                 case '2': case '3': case '4':
 880                         depth = fmt[1] - '0';
 881                         break;
 882                 default:
 883                         depth = 1;
 884         }
 885
 886         rcu_read_lock();
 887         for (i = 0; i < depth; i++, d = p) {
 888                 if (check_pointer(&buf, end, d, spec)) {
 889                         rcu_read_unlock();
 890                         return buf;
 891                 }
 892
 893                 p = READ_ONCE(d->d_parent);
 894                 array[i] = READ_ONCE(d->d_name.name);
 895                 if (p == d) {
 896                         if (i)
 897                                 array[i] = "";
 898                         i++;
 899                         break;
 900                 }
 901         }
 902         s = array[--i];
 903         for (n = 0; n != spec.precision; n++, buf++) {
 904                 char c = *s++;
 905                 if (!c) {
 906                         if (!i)
 907                                 break;
 908                         c = '/';
 909                         s = array[--i];
 910                 }
 911                 if (buf < end)
 912                         *buf = c;
 913         }
 914         rcu_read_unlock();
 915         return widen_string(buf, n, end, spec);
 916 }
 917
 918 static noinline_for_stack
 919 char *file_dentry_name(char *buf, char *end, const struct file *f,
 920                         struct printf_spec spec, const char *fmt)
 921 {
 922         if (check_pointer(&buf, end, f, spec))
 923                 return buf;
 924
 925         return dentry_name(buf, end, f->f_path.dentry, spec, fmt);
 926 }
 927 #ifdef CONFIG_BLOCK
 928 static noinline_for_stack
 929 char *bdev_name(char *buf, char *end, struct block_device *bdev,
 930                 struct printf_spec spec, const char *fmt)
 931 {
 932         struct gendisk *hd;
 933
 934         if (check_pointer(&buf, end, bdev, spec))
 935                 return buf;
 936
 937         hd = bdev->bd_disk;
 938         buf = string(buf, end, hd->disk_name, spec);
 939         if (bdev->bd_part->partno) {
 940                 if (isdigit(hd->disk_name[strlen(hd->disk_name)-1])) {
 941                         if (buf < end)
 942                                 *buf = 'p';
 943                         buf++;
 944                 }
 945                 buf = number(buf, end, bdev->bd_part->partno, spec);
 946         }
 947         return buf;
 948 }
 949 #endif
 950
 951 static noinline_for_stack
 952 char *symbol_string(char *buf, char *end, void *ptr,
 953                     struct printf_spec spec, const char *fmt)
 954 {
 955         unsigned long value;
 956 #ifdef CONFIG_KALLSYMS
 957         char sym[KSYM_SYMBOL_LEN];
 958 #endif
 959
 960         if (fmt[1] == 'R')
 961                 ptr = __builtin_extract_return_addr(ptr);
 962         value = (unsigned long)ptr;
 963
 964 #ifdef CONFIG_KALLSYMS
 965         if (*fmt == 'B')
 966                 sprint_backtrace(sym, value);
 967         else if (*fmt != 's')
 968                 sprint_symbol(sym, value);
 969         else
 970                 sprint_symbol_no_offset(sym, value);
 971
 972         return string_nocheck(buf, end, sym, spec);
 973 #else
 974         return special_hex_number(buf, end, value, sizeof(void *));
 975 #endif
 976 }
 977
 978 static const struct printf_spec default_str_spec = {
 979         .field_width = -1,
 980         .precision = -1,
 981 };
 982
 983 static const struct printf_spec default_flag_spec = {
 984         .base = 16,
 985         .precision = -1,
 986         .flags = SPECIAL | SMALL,
 987 };
 988
 989 static const struct printf_spec default_dec_spec = {
 990         .base = 10,
 991         .precision = -1,
 992 };
 993
 994 static const struct printf_spec default_dec02_spec = {
 995         .base = 10,
 996         .field_width = 2,
 997         .precision = -1,
 998         .flags = ZEROPAD,
 999 };
1000
1001 static const struct printf_spec default_dec04_spec = {
1002         .base = 10,
1003         .field_width = 4,
1004         .precision = -1,
1005         .flags = ZEROPAD,
1006 };
1007
1008 static noinline_for_stack
1009 char *resource_string(char *buf, char *end, struct resource *res,
1010                       struct printf_spec spec, const char *fmt)
1011 {
1012 #ifndef IO_RSRC_PRINTK_SIZE
1013 #define IO_RSRC_PRINTK_SIZE     6
1014 #endif
1015
1016 #ifndef MEM_RSRC_PRINTK_SIZE
1017 #define MEM_RSRC_PRINTK_SIZE    10
1018 #endif
1019         static const struct printf_spec io_spec = {
1020                 .base = 16,
1021                 .field_width = IO_RSRC_PRINTK_SIZE,
1022                 .precision = -1,
1023                 .flags = SPECIAL | SMALL | ZEROPAD,
1024         };
1025         static const struct printf_spec mem_spec = {
1026                 .base = 16,
1027                 .field_width = MEM_RSRC_PRINTK_SIZE,
1028                 .precision = -1,
1029                 .flags = SPECIAL | SMALL | ZEROPAD,
1030         };
1031         static const struct printf_spec bus_spec = {
1032                 .base = 16,
1033                 .field_width = 2,
1034                 .precision = -1,
1035                 .flags = SMALL | ZEROPAD,
1036         };
1037         static const struct printf_spec str_spec = {
1038                 .field_width = -1,
1039                 .precision = 10,
1040                 .flags = LEFT,
1041         };
1042
1043         /* 32-bit res (sizeof==4): 10 chars in dec, 10 in hex ("0x" + 8)
1044          * 64-bit res (sizeof==8): 20 chars in dec, 18 in hex ("0x" + 16) */
1045 #define RSRC_BUF_SIZE           ((2 * sizeof(resource_size_t)) + 4)
1046 #define FLAG_BUF_SIZE           (2 * sizeof(res->flags))
1047 #define DECODED_BUF_SIZE        sizeof("[mem - 64bit pref window disabled]")
1048 #define RAW_BUF_SIZE            sizeof("[mem - flags 0x]")
1049         char sym[max(2*RSRC_BUF_SIZE + DECODED_BUF_SIZE,
1050                      2*RSRC_BUF_SIZE + FLAG_BUF_SIZE + RAW_BUF_SIZE)];
1051
1052         char *p = sym, *pend = sym + sizeof(sym);
1053         int decode = (fmt[0] == 'R') ? 1 : 0;
1054         const struct printf_spec *specp;
1055
1056         if (check_pointer(&buf, end, res, spec))
1057                 return buf;
1058
1059         *p++ = '[';
1060         if (res->flags & IORESOURCE_IO) {
1061                 p = string_nocheck(p, pend, "io  ", str_spec);
1062                 specp = &io_spec;
1063         } else if (res->flags & IORESOURCE_MEM) {
1064                 p = string_nocheck(p, pend, "mem ", str_spec);
1065                 specp = &mem_spec;
1066         } else if (res->flags & IORESOURCE_IRQ) {
1067                 p = string_nocheck(p, pend, "irq ", str_spec);
1068                 specp = &default_dec_spec;
1069         } else if (res->flags & IORESOURCE_DMA) {
1070                 p = string_nocheck(p, pend, "dma ", str_spec);
1071                 specp = &default_dec_spec;
1072         } else if (res->flags & IORESOURCE_BUS) {
1073                 p = string_nocheck(p, pend, "bus ", str_spec);
1074                 specp = &bus_spec;
1075         } else {
1076                 p = string_nocheck(p, pend, "??? ", str_spec);
1077                 specp = &mem_spec;
1078                 decode = 0;
1079         }
1080         if (decode && res->flags & IORESOURCE_UNSET) {
1081                 p = string_nocheck(p, pend, "size ", str_spec);
1082                 p = number(p, pend, resource_size(res), *specp);
1083         } else {
1084                 p = number(p, pend, res->start, *specp);
1085                 if (res->start != res->end) {
1086                         *p++ = '-';
1087                         p = number(p, pend, res->end, *specp);
1088                 }
1089         }
1090         if (decode) {
1091                 if (res->flags & IORESOURCE_MEM_64)
1092                         p = string_nocheck(p, pend, " 64bit", str_spec);
1093                 if (res->flags & IORESOURCE_PREFETCH)
1094                         p = string_nocheck(p, pend, " pref", str_spec);
1095                 if (res->flags & IORESOURCE_WINDOW)
1096                         p = string_nocheck(p, pend, " window", str_spec);
1097                 if (res->flags & IORESOURCE_DISABLED)
1098                         p = string_nocheck(p, pend, " disabled", str_spec);
1099         } else {
1100                 p = string_nocheck(p, pend, " flags ", str_spec);
1101                 p = number(p, pend, res->flags, default_flag_spec);
1102         }
1103         *p++ = ']';
1104         *p = '\0';
1105
1106         return string_nocheck(buf, end, sym, spec);
1107 }
1108
1109 static noinline_for_stack
1110 char *hex_string(char *buf, char *end, u8 *addr, struct printf_spec spec,
1111                  const char *fmt)
1112 {
1113         int i, len = 1;         /* if we pass '%ph[CDN]', field width remains
1114                                    negative value, fallback to the default */
1115         char separator;
1116
1117         if (spec.field_width == 0)
1118                 /* nothing to print */
1119                 return buf;
1120
1121         if (check_pointer(&buf, end, addr, spec))
1122                 return buf;
1123
1124         switch (fmt[1]) {
1125         case 'C':
1126                 separator = ':';
1127                 break;
1128         case 'D':
1129                 separator = '-';
1130                 break;
1131         case 'N':
1132                 separator = 0;
1133                 break;
1134         default:
1135                 separator = ' ';
1136                 break;
1137         }
1138
1139         if (spec.field_width > 0)
1140                 len = min_t(int, spec.field_width, 64);
1141
1142         for (i = 0; i < len; ++i) {
1143                 if (buf < end)
1144                         *buf = hex_asc_hi(addr[i]);
1145                 ++buf;
1146                 if (buf < end)
1147                         *buf = hex_asc_lo(addr[i]);
1148                 ++buf;
1149
1150                 if (separator && i != len - 1) {
1151                         if (buf < end)
1152                                 *buf = separator;
1153                         ++buf;
1154                 }
1155         }
1156
1157         return buf;
1158 }
1159
1160 static noinline_for_stack
1161 char *bitmap_string(char *buf, char *end, unsigned long *bitmap,
1162                     struct printf_spec spec, const char *fmt)
1163 {
1164         const int CHUNKSZ = 32;
1165         int nr_bits = max_t(int, spec.field_width, 0);
1166         int i, chunksz;
1167         bool first = true;
1168
1169         if (check_pointer(&buf, end, bitmap, spec))
1170                 return buf;
1171
1172         /* reused to print numbers */
1173         spec = (struct printf_spec){ .flags = SMALL | ZEROPAD, .base = 16 };
1174
1175         chunksz = nr_bits & (CHUNKSZ - 1);
1176         if (chunksz == 0)
1177                 chunksz = CHUNKSZ;
1178
1179         i = ALIGN(nr_bits, CHUNKSZ) - CHUNKSZ;
1180         for (; i >= 0; i -= CHUNKSZ) {
1181                 u32 chunkmask, val;
1182                 int word, bit;
1183
1184                 chunkmask = ((1ULL << chunksz) - 1);
1185                 word = i / BITS_PER_LONG;
1186                 bit = i % BITS_PER_LONG;
1187                 val = (bitmap[word] >> bit) & chunkmask;
1188
1189                 if (!first) {
1190                         if (buf < end)
1191                                 *buf = ',';
1192                         buf++;
1193                 }
1194                 first = false;
1195
1196                 spec.field_width = DIV_ROUND_UP(chunksz, 4);
1197                 buf = number(buf, end, val, spec);
1198
1199                 chunksz = CHUNKSZ;
1200         }
1201         return buf;
1202 }
1203
1204 static noinline_for_stack
1205 char *bitmap_list_string(char *buf, char *end, unsigned long *bitmap,
1206                          struct printf_spec spec, const char *fmt)
1207 {
1208         int nr_bits = max_t(int, spec.field_width, 0);
1209         /* current bit is 'cur', most recently seen range is [rbot, rtop] */
1210         int cur, rbot, rtop;
1211         bool first = true;
1212
1213         if (check_pointer(&buf, end, bitmap, spec))
1214                 return buf;
1215
1216         rbot = cur = find_first_bit(bitmap, nr_bits);
1217         while (cur < nr_bits) {
1218                 rtop = cur;
1219                 cur = find_next_bit(bitmap, nr_bits, cur + 1);
1220                 if (cur < nr_bits && cur <= rtop + 1)
1221                         continue;
1222
1223                 if (!first) {
1224                         if (buf < end)
1225                                 *buf = ',';
1226                         buf++;
1227                 }
1228                 first = false;
1229
1230                 buf = number(buf, end, rbot, default_dec_spec);
1231                 if (rbot < rtop) {
1232                         if (buf < end)
1233                                 *buf = '-';
1234                         buf++;
1235
1236                         buf = number(buf, end, rtop, default_dec_spec);
1237                 }
1238
1239                 rbot = cur;
1240         }
1241         return buf;
1242 }
1243
1244 static noinline_for_stack
1245 char *mac_address_string(char *buf, char *end, u8 *addr,
1246                          struct printf_spec spec, const char *fmt)
1247 {
1248         char mac_addr[sizeof("xx:xx:xx:xx:xx:xx")];
1249         char *p = mac_addr;
1250         int i;
1251         char separator;
1252         bool reversed = false;
1253
1254         if (check_pointer(&buf, end, addr, spec))
1255                 return buf;
1256
1257         switch (fmt[1]) {
1258         case 'F':
1259                 separator = '-';
1260                 break;
1261
1262         case 'R':
1263                 reversed = true;
1264                 /* fall through */
1265
1266         default:
1267                 separator = ':';
1268                 break;
1269         }
1270
1271         for (i = 0; i < 6; i++) {
1272                 if (reversed)
1273                         p = hex_byte_pack(p, addr[5 - i]);
1274                 else
1275                         p = hex_byte_pack(p, addr[i]);
1276
1277                 if (fmt[0] == 'M' && i != 5)
1278                         *p++ = separator;
1279         }
1280         *p = '\0';
1281
1282         return string_nocheck(buf, end, mac_addr, spec);
1283 }
1284
1285 static noinline_for_stack
1286 char *ip4_string(char *p, const u8 *addr, const char *fmt)
1287 {
1288         int i;
1289         bool leading_zeros = (fmt[0] == 'i');
1290         int index;
1291         int step;
1292
1293         switch (fmt[2]) {
1294         case 'h':
1295 #ifdef __BIG_ENDIAN
1296                 index = 0;
1297                 step = 1;
1298 #else
1299                 index = 3;
1300                 step = -1;
1301 #endif
1302                 break;
1303         case 'l':
1304                 index = 3;
1305                 step = -1;
1306                 break;
1307         case 'n':
1308         case 'b':
1309         default:
1310                 index = 0;
1311                 step = 1;
1312                 break;
1313         }
1314         for (i = 0; i < 4; i++) {
1315                 char temp[4] __aligned(2);      /* hold each IP quad in reverse order */
1316                 int digits = put_dec_trunc8(temp, addr[index]) - temp;
1317                 if (leading_zeros) {
1318                         if (digits < 3)
1319                                 *p++ = '0';
1320                         if (digits < 2)
1321                                 *p++ = '0';
1322                 }
1323                 /* reverse the digits in the quad */
1324                 while (digits--)
1325                         *p++ = temp[digits];
1326                 if (i < 3)
1327                         *p++ = '.';
1328                 index += step;
1329         }
1330         *p = '\0';
1331
1332         return p;
1333 }
1334
1335 static noinline_for_stack
1336 char *ip6_compressed_string(char *p, const char *addr)
1337 {
1338         int i, j, range;
1339         unsigned char zerolength[8];
1340         int longest = 1;
1341         int colonpos = -1;
1342         u16 word;
1343         u8 hi, lo;
1344         bool needcolon = false;
1345         bool useIPv4;
1346         struct in6_addr in6;
1347
1348         memcpy(&in6, addr, sizeof(struct in6_addr));
1349
1350         useIPv4 = ipv6_addr_v4mapped(&in6) || ipv6_addr_is_isatap(&in6);
1351
1352         memset(zerolength, 0, sizeof(zerolength));
1353
1354         if (useIPv4)
1355                 range = 6;
1356         else
1357                 range = 8;
1358
1359         /* find position of longest 0 run */
1360         for (i = 0; i < range; i++) {
1361                 for (j = i; j < range; j++) {
1362                         if (in6.s6_addr16[j] != 0)
1363                                 break;
1364                         zerolength[i]++;
1365                 }
1366         }
1367         for (i = 0; i < range; i++) {
1368                 if (zerolength[i] > longest) {
1369                         longest = zerolength[i];
1370                         colonpos = i;
1371                 }
1372         }
1373         if (longest == 1)               /* don't compress a single 0 */
1374                 colonpos = -1;
1375
1376         /* emit address */
1377         for (i = 0; i < range; i++) {
1378                 if (i == colonpos) {
1379                         if (needcolon || i == 0)
1380                                 *p++ = ':';
1381                         *p++ = ':';
1382                         needcolon = false;
1383                         i += longest - 1;
1384                         continue;
1385                 }
1386                 if (needcolon) {
1387                         *p++ = ':';
1388                         needcolon = false;
1389                 }
1390                 /* hex u16 without leading 0s */
1391                 word = ntohs(in6.s6_addr16[i]);
1392                 hi = word >> 8;
1393                 lo = word & 0xff;
1394                 if (hi) {
1395                         if (hi > 0x0f)
1396                                 p = hex_byte_pack(p, hi);
1397                         else
1398                                 *p++ = hex_asc_lo(hi);
1399                         p = hex_byte_pack(p, lo);
1400                 }
1401                 else if (lo > 0x0f)
1402                         p = hex_byte_pack(p, lo);
1403                 else
1404                         *p++ = hex_asc_lo(lo);
1405                 needcolon = true;
1406         }
1407
1408         if (useIPv4) {
1409                 if (needcolon)
1410                         *p++ = ':';
1411                 p = ip4_string(p, &in6.s6_addr[12], "I4");
1412         }
1413         *p = '\0';
1414
1415         return p;
1416 }
1417
1418 static noinline_for_stack
1419 char *ip6_string(char *p, const char *addr, const char *fmt)
1420 {
1421         int i;
1422
1423         for (i = 0; i < 8; i++) {
1424                 p = hex_byte_pack(p, *addr++);
1425                 p = hex_byte_pack(p, *addr++);
1426                 if (fmt[0] == 'I' && i != 7)
1427                         *p++ = ':';
1428         }
1429         *p = '\0';
1430
1431         return p;
1432 }
1433
1434 static noinline_for_stack
1435 char *ip6_addr_string(char *buf, char *end, const u8 *addr,
1436                       struct printf_spec spec, const char *fmt)
1437 {
1438         char ip6_addr[sizeof("xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255")];
1439
1440         if (fmt[0] == 'I' && fmt[2] == 'c')
1441                 ip6_compressed_string(ip6_addr, addr);
1442         else
1443                 ip6_string(ip6_addr, addr, fmt);
1444
1445         return string_nocheck(buf, end, ip6_addr, spec);
1446 }
1447
1448 static noinline_for_stack
1449 char *ip4_addr_string(char *buf, char *end, const u8 *addr,
1450                       struct printf_spec spec, const char *fmt)
1451 {
1452         char ip4_addr[sizeof("255.255.255.255")];
1453
1454         ip4_string(ip4_addr, addr, fmt);
1455
1456         return string_nocheck(buf, end, ip4_addr, spec);
1457 }
1458
1459 static noinline_for_stack
1460 char *ip6_addr_string_sa(char *buf, char *end, const struct sockaddr_in6 *sa,
1461                          struct printf_spec spec, const char *fmt)
1462 {
1463         bool have_p = false, have_s = false, have_f = false, have_c = false;
1464         char ip6_addr[sizeof("[xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255]") +
1465                       sizeof(":12345") + sizeof("/123456789") +
1466                       sizeof("%1234567890")];
1467         char *p = ip6_addr, *pend = ip6_addr + sizeof(ip6_addr);
1468         const u8 *addr = (const u8 *) &sa->sin6_addr;
1469         char fmt6[2] = { fmt[0], '6' };
1470         u8 off = 0;
1471
1472         fmt++;
1473         while (isalpha(*++fmt)) {
1474                 switch (*fmt) {
1475                 case 'p':
1476                         have_p = true;
1477                         break;
1478                 case 'f':
1479                         have_f = true;
1480                         break;
1481                 case 's':
1482                         have_s = true;
1483                         break;
1484                 case 'c':
1485                         have_c = true;
1486                         break;
1487                 }
1488         }
1489
1490         if (have_p || have_s || have_f) {
1491                 *p = '[';
1492                 off = 1;
1493         }
1494
1495         if (fmt6[0] == 'I' && have_c)
1496                 p = ip6_compressed_string(ip6_addr + off, addr);
1497         else
1498                 p = ip6_string(ip6_addr + off, addr, fmt6);
1499
1500         if (have_p || have_s || have_f)
1501                 *p++ = ']';
1502
1503         if (have_p) {
1504                 *p++ = ':';
1505                 p = number(p, pend, ntohs(sa->sin6_port), spec);
1506         }
1507         if (have_f) {
1508                 *p++ = '/';
1509                 p = number(p, pend, ntohl(sa->sin6_flowinfo &
1510                                           IPV6_FLOWINFO_MASK), spec);
1511         }
1512         if (have_s) {
1513                 *p++ = '%';
1514                 p = number(p, pend, sa->sin6_scope_id, spec);
1515         }
1516         *p = '\0';
1517
1518         return string_nocheck(buf, end, ip6_addr, spec);
1519 }
1520
1521 static noinline_for_stack
1522 char *ip4_addr_string_sa(char *buf, char *end, const struct sockaddr_in *sa,
1523                          struct printf_spec spec, const char *fmt)
1524 {
1525         bool have_p = false;
1526         char *p, ip4_addr[sizeof("255.255.255.255") + sizeof(":12345")];
1527         char *pend = ip4_addr + sizeof(ip4_addr);
1528         const u8 *addr = (const u8 *) &sa->sin_addr.s_addr;
1529         char fmt4[3] = { fmt[0], '4', 0 };
1530
1531         fmt++;
1532         while (isalpha(*++fmt)) {
1533                 switch (*fmt) {
1534                 case 'p':
1535                         have_p = true;
1536                         break;
1537                 case 'h':
1538                 case 'l':
1539                 case 'n':
1540                 case 'b':
1541                         fmt4[2] = *fmt;
1542                         break;
1543                 }
1544         }
1545
1546         p = ip4_string(ip4_addr, addr, fmt4);
1547         if (have_p) {
1548                 *p++ = ':';
1549                 p = number(p, pend, ntohs(sa->sin_port), spec);
1550         }
1551         *p = '\0';
1552
1553         return string_nocheck(buf, end, ip4_addr, spec);
1554 }
1555
1556 static noinline_for_stack
1557 char *ip_addr_string(char *buf, char *end, const void *ptr,
1558                      struct printf_spec spec, const char *fmt)
1559 {
1560         char *err_fmt_msg;
1561
1562         if (check_pointer(&buf, end, ptr, spec))
1563                 return buf;
1564
1565         switch (fmt[1]) {
1566         case '6':
1567                 return ip6_addr_string(buf, end, ptr, spec, fmt);
1568         case '4':
1569                 return ip4_addr_string(buf, end, ptr, spec, fmt);
1570         case 'S': {
1571                 const union {
1572                         struct sockaddr         raw;
1573                         struct sockaddr_in      v4;
1574                         struct sockaddr_in6     v6;
1575                 } *sa = ptr;
1576
1577                 switch (sa->raw.sa_family) {
1578                 case AF_INET:
1579                         return ip4_addr_string_sa(buf, end, &sa->v4, spec, fmt);
1580                 case AF_INET6:
1581                         return ip6_addr_string_sa(buf, end, &sa->v6, spec, fmt);
1582                 default:
1583                         return error_string(buf, end, "(einval)", spec);
1584                 }}
1585         }
1586
1587         err_fmt_msg = fmt[0] == 'i' ? "(%pi?)" : "(%pI?)";
1588         return error_string(buf, end, err_fmt_msg, spec);
1589 }
1590
1591 static noinline_for_stack
1592 char *escaped_string(char *buf, char *end, u8 *addr, struct printf_spec spec,
1593                      const char *fmt)
1594 {
1595         bool found = true;
1596         int count = 1;
1597         unsigned int flags = 0;
1598         int len;
1599
1600         if (spec.field_width == 0)
1601                 return buf;                             /* nothing to print */
1602
1603         if (check_pointer(&buf, end, addr, spec))
1604                 return buf;
1605
1606         do {
1607                 switch (fmt[count++]) {
1608                 case 'a':
1609                         flags |= ESCAPE_ANY;
1610                         break;
1611                 case 'c':
1612                         flags |= ESCAPE_SPECIAL;
1613                         break;
1614                 case 'h':
1615                         flags |= ESCAPE_HEX;
1616                         break;
1617                 case 'n':
1618                         flags |= ESCAPE_NULL;
1619                         break;
1620                 case 'o':
1621                         flags |= ESCAPE_OCTAL;
1622                         break;
1623                 case 'p':
1624                         flags |= ESCAPE_NP;
1625                         break;
1626                 case 's':
1627                         flags |= ESCAPE_SPACE;
1628                         break;
1629                 default:
1630                         found = false;
1631                         break;
1632                 }
1633         } while (found);
1634
1635         if (!flags)
1636                 flags = ESCAPE_ANY_NP;
1637
1638         len = spec.field_width < 0 ? 1 : spec.field_width;
1639
1640         /*
1641          * string_escape_mem() writes as many characters as it can to
1642          * the given buffer, and returns the total size of the output
1643          * had the buffer been big enough.
1644          */
1645         buf += string_escape_mem(addr, len, buf, buf < end ? end - buf : 0, flags, NULL);
1646
1647         return buf;
1648 }
1649
1650 static char *va_format(char *buf, char *end, struct va_format *va_fmt,
1651                        struct printf_spec spec, const char *fmt)
1652 {
1653         va_list va;
1654
1655         if (check_pointer(&buf, end, va_fmt, spec))
1656                 return buf;
1657
1658         va_copy(va, *va_fmt->va);
1659         buf += vsnprintf(buf, end > buf ? end - buf : 0, va_fmt->fmt, va);
1660         va_end(va);
1661
1662         return buf;
1663 }
1664
1665 static noinline_for_stack
1666 char *uuid_string(char *buf, char *end, const u8 *addr,
1667                   struct printf_spec spec, const char *fmt)
1668 {
1669         char uuid[UUID_STRING_LEN + 1];
1670         char *p = uuid;
1671         int i;
1672         const u8 *index = uuid_index;
1673         bool uc = false;
1674
1675         if (check_pointer(&buf, end, addr, spec))
1676                 return buf;
1677
1678         switch (*(++fmt)) {
1679         case 'L':
1680                 uc = true;              /* fall-through */
1681         case 'l':
1682                 index = guid_index;
1683                 break;
1684         case 'B':
1685                 uc = true;
1686                 break;
1687         }
1688
1689         for (i = 0; i < 16; i++) {
1690                 if (uc)
1691                         p = hex_byte_pack_upper(p, addr[index[i]]);
1692                 else
1693                         p = hex_byte_pack(p, addr[index[i]]);
1694                 switch (i) {
1695                 case 3:
1696                 case 5:
1697                 case 7:
1698                 case 9:
1699                         *p++ = '-';
1700                         break;
1701                 }
1702         }
1703
1704         *p = 0;
1705
1706         return string_nocheck(buf, end, uuid, spec);
1707 }
1708
1709 static noinline_for_stack
1710 char *netdev_bits(char *buf, char *end, const void *addr,
1711                   struct printf_spec spec,  const char *fmt)
1712 {
1713         unsigned long long num;
1714         int size;
1715
1716         if (check_pointer(&buf, end, addr, spec))
1717                 return buf;
1718
1719         switch (fmt[1]) {
1720         case 'F':
1721                 num = *(const netdev_features_t *)addr;
1722                 size = sizeof(netdev_features_t);
1723                 break;
1724         default:
1725                 return error_string(buf, end, "(%pN?)", spec);
1726         }
1727
1728         return special_hex_number(buf, end, num, size);
1729 }
1730
1731 static noinline_for_stack
1732 char *address_val(char *buf, char *end, const void *addr,
1733                   struct printf_spec spec, const char *fmt)
1734 {
1735         unsigned long long num;
1736         int size;
1737
1738         if (check_pointer(&buf, end, addr, spec))
1739                 return buf;
1740
1741         switch (fmt[1]) {
1742         case 'd':
1743                 num = *(const dma_addr_t *)addr;
1744                 size = sizeof(dma_addr_t);
1745                 break;
1746         case 'p':
1747         default:
1748                 num = *(const phys_addr_t *)addr;
1749                 size = sizeof(phys_addr_t);
1750                 break;
1751         }
1752
1753         return special_hex_number(buf, end, num, size);
1754 }
1755
1756 static noinline_for_stack
1757 char *date_str(char *buf, char *end, const struct rtc_time *tm, bool r)
1758 {
1759         int year = tm->tm_year + (r ? 0 : 1900);
1760         int mon = tm->tm_mon + (r ? 0 : 1);
1761
1762         buf = number(buf, end, year, default_dec04_spec);
1763         if (buf < end)
1764                 *buf = '-';
1765         buf++;
1766
1767         buf = number(buf, end, mon, default_dec02_spec);
1768         if (buf < end)
1769                 *buf = '-';
1770         buf++;
1771
1772         return number(buf, end, tm->tm_mday, default_dec02_spec);
1773 }
1774
1775 static noinline_for_stack
1776 char *time_str(char *buf, char *end, const struct rtc_time *tm, bool r)
1777 {
1778         buf = number(buf, end, tm->tm_hour, default_dec02_spec);
1779         if (buf < end)
1780                 *buf = ':';
1781         buf++;
1782
1783         buf = number(buf, end, tm->tm_min, default_dec02_spec);
1784         if (buf < end)
1785                 *buf = ':';
1786         buf++;
1787
1788         return number(buf, end, tm->tm_sec, default_dec02_spec);
1789 }
1790
1791 static noinline_for_stack
1792 char *rtc_str(char *buf, char *end, const struct rtc_time *tm,
1793               struct printf_spec spec, const char *fmt)
1794 {
1795         bool have_t = true, have_d = true;
1796         bool raw = false;
1797         int count = 2;
1798
1799         if (check_pointer(&buf, end, tm, spec))
1800                 return buf;
1801
1802         switch (fmt[count]) {
1803         case 'd':
1804                 have_t = false;
1805                 count++;
1806                 break;
1807         case 't':
1808                 have_d = false;
1809                 count++;
1810                 break;
1811         }
1812
1813         raw = fmt[count] == 'r';
1814
1815         if (have_d)
1816                 buf = date_str(buf, end, tm, raw);
1817         if (have_d && have_t) {
1818                 /* Respect ISO 8601 */
1819                 if (buf < end)
1820                         *buf = 'T';
1821                 buf++;
1822         }
1823         if (have_t)
1824                 buf = time_str(buf, end, tm, raw);
1825
1826         return buf;
1827 }
1828
1829 static noinline_for_stack
1830 char *time_and_date(char *buf, char *end, void *ptr, struct printf_spec spec,
1831                     const char *fmt)
1832 {
1833         switch (fmt[1]) {
1834         case 'R':
1835                 return rtc_str(buf, end, (const struct rtc_time *)ptr, spec, fmt);
1836         default:
1837                 return error_string(buf, end, "(%ptR?)", spec);
1838         }
1839 }
1840
1841 static noinline_for_stack
1842 char *clock(char *buf, char *end, struct clk *clk, struct printf_spec spec,
1843             const char *fmt)
1844 {
1845         if (!IS_ENABLED(CONFIG_HAVE_CLK))
1846                 return error_string(buf, end, "(%pC?)", spec);
1847
1848         if (check_pointer(&buf, end, clk, spec))
1849                 return buf;
1850
1851         switch (fmt[1]) {
1852         case 'n':
1853         default:
1854 #ifdef CONFIG_COMMON_CLK
1855                 return string(buf, end, __clk_get_name(clk), spec);
1856 #else
1857                 return ptr_to_id(buf, end, clk, spec);
1858 #endif
1859         }
1860 }
1861
1862 static
1863 char *format_flags(char *buf, char *end, unsigned long flags,
1864                                         const struct trace_print_flags *names)
1865 {
1866         unsigned long mask;
1867
1868         for ( ; flags && names->name; names++) {
1869                 mask = names->mask;
1870                 if ((flags & mask) != mask)
1871                         continue;
1872
1873                 buf = string(buf, end, names->name, default_str_spec);
1874
1875                 flags &= ~mask;
1876                 if (flags) {
1877                         if (buf < end)
1878                                 *buf = '|';
1879                         buf++;
1880                 }
1881         }
1882
1883         if (flags)
1884                 buf = number(buf, end, flags, default_flag_spec);
1885
1886         return buf;
1887 }
1888
1889 static noinline_for_stack
1890 char *flags_string(char *buf, char *end, void *flags_ptr,
1891                    struct printf_spec spec, const char *fmt)
1892 {
1893         unsigned long flags;
1894         const struct trace_print_flags *names;
1895
1896         if (check_pointer(&buf, end, flags_ptr, spec))
1897                 return buf;
1898
1899         switch (fmt[1]) {
1900         case 'p':
1901                 flags = *(unsigned long *)flags_ptr;
1902                 /* Remove zone id */
1903                 flags &= (1UL << NR_PAGEFLAGS) - 1;
1904                 names = pageflag_names;
1905                 break;
1906         case 'v':
1907                 flags = *(unsigned long *)flags_ptr;
1908                 names = vmaflag_names;
1909                 break;
1910         case 'g':
1911                 flags = *(gfp_t *)flags_ptr;
1912                 names = gfpflag_names;
1913                 break;
1914         default:
1915                 return error_string(buf, end, "(%pG?)", spec);
1916         }
1917
1918         return format_flags(buf, end, flags, names);
1919 }
1920
1921 static noinline_for_stack
1922 char *fwnode_full_name_string(struct fwnode_handle *fwnode, char *buf,
1923                               char *end)
1924 {
1925         int depth;
1926
1927         /* Loop starting from the root node to the current node. */
1928         for (depth = fwnode_count_parents(fwnode); depth >= 0; depth--) {
1929                 struct fwnode_handle *__fwnode =
1930                         fwnode_get_nth_parent(fwnode, depth);
1931
1932                 buf = string(buf, end, fwnode_get_name_prefix(__fwnode),
1933                              default_str_spec);
1934                 buf = string(buf, end, fwnode_get_name(__fwnode),
1935                              default_str_spec);
1936
1937                 fwnode_handle_put(__fwnode);
1938         }
1939
1940         return buf;
1941 }
1942
1943 static noinline_for_stack
1944 char *device_node_string(char *buf, char *end, struct device_node *dn,
1945                          struct printf_spec spec, const char *fmt)
1946 {
1947         char tbuf[sizeof("xxxx") + 1];
1948         const char *p;
1949         int ret;
1950         char *buf_start = buf;
1951         struct property *prop;
1952         bool has_mult, pass;
1953         static const struct printf_spec num_spec = {
1954                 .flags = SMALL,
1955                 .field_width = -1,
1956                 .precision = -1,
1957                 .base = 10,
1958         };
1959
1960         struct printf_spec str_spec = spec;
1961         str_spec.field_width = -1;
1962
1963         if (fmt[0] != 'F')
1964                 return error_string(buf, end, "(%pO?)", spec);
1965
1966         if (!IS_ENABLED(CONFIG_OF))
1967                 return error_string(buf, end, "(%pOF?)", spec);
1968
1969         if (check_pointer(&buf, end, dn, spec))
1970                 return buf;
1971
1972         /* simple case without anything any more format specifiers */
1973         fmt++;
1974         if (fmt[0] == '\0' || strcspn(fmt,"fnpPFcC") > 0)
1975                 fmt = "f";
1976
1977         for (pass = false; strspn(fmt,"fnpPFcC"); fmt++, pass = true) {
1978                 int precision;
1979                 if (pass) {
1980                         if (buf < end)
1981                                 *buf = ':';
1982                         buf++;
1983                 }
1984
1985                 switch (*fmt) {
1986                 case 'f':       /* full_name */
1987                         buf = fwnode_full_name_string(of_fwnode_handle(dn), buf,
1988                                                       end);
1989                         break;
1990                 case 'n':       /* name */
1991                         p = fwnode_get_name(of_fwnode_handle(dn));
1992                         precision = str_spec.precision;
1993                         str_spec.precision = strchrnul(p, '@') - p;
1994                         buf = string(buf, end, p, str_spec);
1995                         str_spec.precision = precision;
1996                         break;
1997                 case 'p':       /* phandle */
1998                         buf = number(buf, end, (unsigned int)dn->phandle, num_spec);
1999                         break;
2000                 case 'P':       /* path-spec */
2001                         p = fwnode_get_name(of_fwnode_handle(dn));
2002                         if (!p[1])
2003                                 p = "/";
2004                         buf = string(buf, end, p, str_spec);
2005                         break;
2006                 case 'F':       /* flags */
2007                         tbuf[0] = of_node_check_flag(dn, OF_DYNAMIC) ? 'D' : '-';
2008                         tbuf[1] = of_node_check_flag(dn, OF_DETACHED) ? 'd' : '-';
2009                         tbuf[2] = of_node_check_flag(dn, OF_POPULATED) ? 'P' : '-';
2010                         tbuf[3] = of_node_check_flag(dn, OF_POPULATED_BUS) ? 'B' : '-';
2011                         tbuf[4] = 0;
2012                         buf = string_nocheck(buf, end, tbuf, str_spec);
2013                         break;
2014                 case 'c':       /* major compatible string */
2015                         ret = of_property_read_string(dn, "compatible", &p);
2016                         if (!ret)
2017                                 buf = string(buf, end, p, str_spec);
2018                         break;
2019                 case 'C':       /* full compatible string */
2020                         has_mult = false;
2021                         of_property_for_each_string(dn, "compatible", prop, p) {
2022                                 if (has_mult)
2023                                         buf = string_nocheck(buf, end, ",", str_spec);
2024                                 buf = string_nocheck(buf, end, "\"", str_spec);
2025                                 buf = string(buf, end, p, str_spec);
2026                                 buf = string_nocheck(buf, end, "\"", str_spec);
2027
2028                                 has_mult = true;
2029                         }
2030                         break;
2031                 default:
2032                         break;
2033                 }
2034         }
2035
2036         return widen_string(buf, buf - buf_start, end, spec);
2037 }
2038
2039 static noinline_for_stack
2040 char *fwnode_string(char *buf, char *end, struct fwnode_handle *fwnode,
2041                     struct printf_spec spec, const char *fmt)
2042 {
2043         struct printf_spec str_spec = spec;
2044         char *buf_start = buf;
2045
2046         str_spec.field_width = -1;
2047
2048         if (*fmt != 'w')
2049                 return error_string(buf, end, "(%pf?)", spec);
2050
2051         if (check_pointer(&buf, end, fwnode, spec))
2052                 return buf;
2053
2054         fmt++;
2055
2056         switch (*fmt) {
2057         case 'P':       /* name */
2058                 buf = string(buf, end, fwnode_get_name(fwnode), str_spec);
2059                 break;
2060         case 'f':       /* full_name */
2061         default:
2062                 buf = fwnode_full_name_string(fwnode, buf, end);
2063                 break;
2064         }
2065
2066         return widen_string(buf, buf - buf_start, end, spec);
2067 }
2068
2069 /*
2070  * Show a '%p' thing.  A kernel extension is that the '%p' is followed
2071  * by an extra set of alphanumeric characters that are extended format
2072  * specifiers.
2073  *
2074  * Please update scripts/checkpatch.pl when adding/removing conversion
2075  * characters.  (Search for "check for vsprintf extension").
2076  *
2077  * Right now we handle:
2078  *
2079  * - 'S' For symbolic direct pointers (or function descriptors) with offset
2080  * - 's' For symbolic direct pointers (or function descriptors) without offset
2081  * - '[Ss]R' as above with __builtin_extract_return_addr() translation
2082  * - '[Ff]' %pf and %pF were obsoleted and later removed in favor of
2083  *          %ps and %pS. Be careful when re-using these specifiers.
2084  * - 'B' For backtraced symbolic direct pointers with offset
2085  * - 'R' For decoded struct resource, e.g., [mem 0x0-0x1f 64bit pref]
2086  * - 'r' For raw struct resource, e.g., [mem 0x0-0x1f flags 0x201]
2087  * - 'b[l]' For a bitmap, the number of bits is determined by the field
2088  *       width which must be explicitly specified either as part of the
2089  *       format string '%32b[l]' or through '%*b[l]', [l] selects
2090  *       range-list format instead of hex format
2091  * - 'M' For a 6-byte MAC address, it prints the address in the
2092  *       usual colon-separated hex notation
2093  * - 'm' For a 6-byte MAC address, it prints the hex address without colons
2094  * - 'MF' For a 6-byte MAC FDDI address, it prints the address
2095  *       with a dash-separated hex notation
2096  * - '[mM]R' For a 6-byte MAC address, Reverse order (Bluetooth)
2097  * - 'I' [46] for IPv4/IPv6 addresses printed in the usual way
2098  *       IPv4 uses dot-separated decimal without leading 0's (1.2.3.4)
2099  *       IPv6 uses colon separated network-order 16 bit hex with leading 0's
2100  *       [S][pfs]
2101  *       Generic IPv4/IPv6 address (struct sockaddr *) that falls back to
2102  *       [4] or [6] and is able to print port [p], flowinfo [f], scope [s]
2103  * - 'i' [46] for 'raw' IPv4/IPv6 addresses
2104  *       IPv6 omits the colons (01020304...0f)
2105  *       IPv4 uses dot-separated decimal with leading 0's (010.123.045.006)
2106  *       [S][pfs]
2107  *       Generic IPv4/IPv6 address (struct sockaddr *) that falls back to
2108  *       [4] or [6] and is able to print port [p], flowinfo [f], scope [s]
2109  * - '[Ii][4S][hnbl]' IPv4 addresses in host, network, big or little endian order
2110  * - 'I[6S]c' for IPv6 addresses printed as specified by
2111  *       http://tools.ietf.org/html/rfc5952
2112  * - 'E[achnops]' For an escaped buffer, where rules are defined by combination
2113  *                of the following flags (see string_escape_mem() for the
2114  *                details):
2115  *                  a - ESCAPE_ANY
2116  *                  c - ESCAPE_SPECIAL
2117  *                  h - ESCAPE_HEX
2118  *                  n - ESCAPE_NULL
2119  *                  o - ESCAPE_OCTAL
2120  *                  p - ESCAPE_NP
2121  *                  s - ESCAPE_SPACE
2122  *                By default ESCAPE_ANY_NP is used.
2123  * - 'U' For a 16 byte UUID/GUID, it prints the UUID/GUID in the form
2124  *       "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx"
2125  *       Options for %pU are:
2126  *         b big endian lower case hex (default)
2127  *         B big endian UPPER case hex
2128  *         l little endian lower case hex
2129  *         L little endian UPPER case hex
2130  *           big endian output byte order is:
2131  *             [0][1][2][3]-[4][5]-[6][7]-[8][9]-[10][11][12][13][14][15]
2132  *           little endian output byte order is:
2133  *             [3][2][1][0]-[5][4]-[7][6]-[8][9]-[10][11][12][13][14][15]
2134  * - 'V' For a struct va_format which contains a format string * and va_list *,
2135  *       call vsnprintf(->format, *->va_list).
2136  *       Implements a "recursive vsnprintf".
2137  *       Do not use this feature without some mechanism to verify the
2138  *       correctness of the format string and va_list arguments.
2139  * - 'K' For a kernel pointer that should be hidden from unprivileged users
2140  * - 'NF' For a netdev_features_t
2141  * - 'h[CDN]' For a variable-length buffer, it prints it as a hex string with
2142  *            a certain separator (' ' by default):
2143  *              C colon
2144  *              D dash
2145  *              N no separator
2146  *            The maximum supported length is 64 bytes of the input. Consider
2147  *            to use print_hex_dump() for the larger input.
2148  * - 'a[pd]' For address types [p] phys_addr_t, [d] dma_addr_t and derivatives
2149  *           (default assumed to be phys_addr_t, passed by reference)
2150  * - 'd[234]' For a dentry name (optionally 2-4 last components)
2151  * - 'D[234]' Same as 'd' but for a struct file
2152  * - 'g' For block_device name (gendisk + partition number)
2153  * - 't[R][dt][r]' For time and date as represented:
2154  *      R    struct rtc_time
2155  * - 'C' For a clock, it prints the name (Common Clock Framework) or address
2156  *       (legacy clock framework) of the clock
2157  * - 'Cn' For a clock, it prints the name (Common Clock Framework) or address
2158  *        (legacy clock framework) of the clock
2159  * - 'G' For flags to be printed as a collection of symbolic strings that would
2160  *       construct the specific value. Supported flags given by option:
2161  *       p page flags (see struct page) given as pointer to unsigned long
2162  *       g gfp flags (GFP_* and __GFP_*) given as pointer to gfp_t
2163  *       v vma flags (VM_*) given as pointer to unsigned long
2164  * - 'OF[fnpPcCF]'  For a device tree object
2165  *                  Without any optional arguments prints the full_name
2166  *                  f device node full_name
2167  *                  n device node name
2168  *                  p device node phandle
2169  *                  P device node path spec (name + @unit)
2170  *                  F device node flags
2171  *                  c major compatible string
2172  *                  C full compatible string
2173  * - 'fw[fP]'   For a firmware node (struct fwnode_handle) pointer
2174  *              Without an option prints the full name of the node
2175  *              f full name
2176  *              P node name, including a possible unit address
2177  * - 'x' For printing the address. Equivalent to "%lx".
2178  * - '[ku]s' For a BPF/tracing related format specifier, e.g. used out of
2179  *           bpf_trace_printk() where [ku] prefix specifies either kernel (k)
2180  *           or user (u) memory to probe, and:
2181  *              s a string, equivalent to "%s" on direct vsnprintf() use
2182  *
2183  * ** When making changes please also update:
2184  *      Documentation/core-api/printk-formats.rst
2185  *
2186  * Note: The default behaviour (unadorned %p) is to hash the address,
2187  * rendering it useful as a unique identifier.
2188  */
2189 static noinline_for_stack
2190 char *pointer(const char *fmt, char *buf, char *end, void *ptr,
2191               struct printf_spec spec)
2192 {
2193         switch (*fmt) {
2194         case 'S':
2195         case 's':
2196                 ptr = dereference_symbol_descriptor(ptr);
2197                 /* Fallthrough */
2198         case 'B':
2199                 return symbol_string(buf, end, ptr, spec, fmt);
2200         case 'R':
2201         case 'r':
2202                 return resource_string(buf, end, ptr, spec, fmt);
2203         case 'h':
2204                 return hex_string(buf, end, ptr, spec, fmt);
2205         case 'b':
2206                 switch (fmt[1]) {
2207                 case 'l':
2208                         return bitmap_list_string(buf, end, ptr, spec, fmt);
2209                 default:
2210                         return bitmap_string(buf, end, ptr, spec, fmt);
2211                 }
2212         case 'M':                       /* Colon separated: 00:01:02:03:04:05 */
2213         case 'm':                       /* Contiguous: 000102030405 */
2214                                         /* [mM]F (FDDI) */
2215                                         /* [mM]R (Reverse order; Bluetooth) */
2216                 return mac_address_string(buf, end, ptr, spec, fmt);
2217         case 'I':                       /* Formatted IP supported
2218                                          * 4:   1.2.3.4
2219                                          * 6:   0001:0203:...:0708
2220                                          * 6c:  1::708 or 1::1.2.3.4
2221                                          */
2222         case 'i':                       /* Contiguous:
2223                                          * 4:   001.002.003.004
2224                                          * 6:   000102...0f
2225                                          */
2226                 return ip_addr_string(buf, end, ptr, spec, fmt);
2227         case 'E':
2228                 return escaped_string(buf, end, ptr, spec, fmt);
2229         case 'U':
2230                 return uuid_string(buf, end, ptr, spec, fmt);
2231         case 'V':
2232                 return va_format(buf, end, ptr, spec, fmt);
2233         case 'K':
2234                 return restricted_pointer(buf, end, ptr, spec);
2235         case 'N':
2236                 return netdev_bits(buf, end, ptr, spec, fmt);
2237         case 'a':
2238                 return address_val(buf, end, ptr, spec, fmt);
2239         case 'd':
2240                 return dentry_name(buf, end, ptr, spec, fmt);
2241         case 't':
2242                 return time_and_date(buf, end, ptr, spec, fmt);
2243         case 'C':
2244                 return clock(buf, end, ptr, spec, fmt);
2245         case 'D':
2246                 return file_dentry_name(buf, end, ptr, spec, fmt);
2247 #ifdef CONFIG_BLOCK
2248         case 'g':
2249                 return bdev_name(buf, end, ptr, spec, fmt);
2250 #endif
2251
2252         case 'G':
2253                 return flags_string(buf, end, ptr, spec, fmt);
2254         case 'O':
2255                 return device_node_string(buf, end, ptr, spec, fmt + 1);
2256         case 'f':
2257                 return fwnode_string(buf, end, ptr, spec, fmt + 1);
2258         case 'x':
2259                 return pointer_string(buf, end, ptr, spec);
2260         case 'e':
2261                 /* %pe with a non-ERR_PTR gets treated as plain %p */
2262                 if (!IS_ERR(ptr))
2263                         break;
2264                 return err_ptr(buf, end, ptr, spec);
2265         case 'u':
2266         case 'k':
2267                 switch (fmt[1]) {
2268                 case 's':
2269                         return string(buf, end, ptr, spec);
2270                 default:
2271                         return error_string(buf, end, "(einval)", spec);
2272                 }
2273         }
2274
2275         /* default is to _not_ leak addresses, hash before printing */
2276         return ptr_to_id(buf, end, ptr, spec);
2277 }
2278
2279 /*
2280  * Helper function to decode printf style format.
2281  * Each call decode a token from the format and return the
2282  * number of characters read (or likely the delta where it wants
2283  * to go on the next call).
2284  * The decoded token is returned through the parameters
2285  *
2286  * 'h', 'l', or 'L' for integer fields
2287  * 'z' support added 23/7/1999 S.H.
2288  * 'z' changed to 'Z' --davidm 1/25/99
2289  * 'Z' changed to 'z' --adobriyan 2017-01-25
2290  * 't' added for ptrdiff_t
2291  *
2292  * @fmt: the format string
2293  * @type of the token returned
2294  * @flags: various flags such as +, -, # tokens..
2295  * @field_width: overwritten width
2296  * @base: base of the number (octal, hex, ...)
2297  * @precision: precision of a number
2298  * @qualifier: qualifier of a number (long, size_t, ...)
2299  */
2300 static noinline_for_stack
2301 int format_decode(const char *fmt, struct printf_spec *spec)
2302 {
2303         const char *start = fmt;
2304         char qualifier;
2305
2306         /* we finished early by reading the field width */
2307         if (spec->type == FORMAT_TYPE_WIDTH) {
2308                 if (spec->field_width < 0) {
2309                         spec->field_width = -spec->field_width;
2310                         spec->flags |= LEFT;
2311                 }
2312                 spec->type = FORMAT_TYPE_NONE;
2313                 goto precision;
2314         }
2315
2316         /* we finished early by reading the precision */
2317         if (spec->type == FORMAT_TYPE_PRECISION) {
2318                 if (spec->precision < 0)
2319                         spec->precision = 0;
2320
2321                 spec->type = FORMAT_TYPE_NONE;
2322                 goto qualifier;
2323         }
2324
2325         /* By default */
2326         spec->type = FORMAT_TYPE_NONE;
2327
2328         for (; *fmt ; ++fmt) {
2329                 if (*fmt == '%')
2330                         break;
2331         }
2332
2333         /* Return the current non-format string */
2334         if (fmt != start || !*fmt)
2335                 return fmt - start;
2336
2337         /* Process flags */
2338         spec->flags = 0;
2339
2340         while (1) { /* this also skips first '%' */
2341                 bool found = true;
2342
2343                 ++fmt;
2344
2345                 switch (*fmt) {
2346                 case '-': spec->flags |= LEFT;    break;
2347                 case '+': spec->flags |= PLUS;    break;
2348                 case ' ': spec->flags |= SPACE;   break;
2349                 case '#': spec->flags |= SPECIAL; break;
2350                 case '0': spec->flags |= ZEROPAD; break;
2351                 default:  found = false;
2352                 }
2353
2354                 if (!found)
2355                         break;
2356         }
2357
2358         /* get field width */
2359         spec->field_width = -1;
2360
2361         if (isdigit(*fmt))
2362                 spec->field_width = skip_atoi(&fmt);
2363         else if (*fmt == '*') {
2364                 /* it's the next argument */
2365                 spec->type = FORMAT_TYPE_WIDTH;
2366                 return ++fmt - start;
2367         }
2368
2369 precision:
2370         /* get the precision */
2371         spec->precision = -1;
2372         if (*fmt == '.') {
2373                 ++fmt;
2374                 if (isdigit(*fmt)) {
2375                         spec->precision = skip_atoi(&fmt);
2376                         if (spec->precision < 0)
2377                                 spec->precision = 0;
2378                 } else if (*fmt == '*') {
2379                         /* it's the next argument */
2380                         spec->type = FORMAT_TYPE_PRECISION;
2381                         return ++fmt - start;
2382                 }
2383         }
2384
2385 qualifier:
2386         /* get the conversion qualifier */
2387         qualifier = 0;
2388         if (*fmt == 'h' || _tolower(*fmt) == 'l' ||
2389             *fmt == 'z' || *fmt == 't') {
2390                 qualifier = *fmt++;
2391                 if (unlikely(qualifier == *fmt)) {
2392                         if (qualifier == 'l') {
2393                                 qualifier = 'L';
2394                                 ++fmt;
2395                         } else if (qualifier == 'h') {
2396                                 qualifier = 'H';
2397                                 ++fmt;
2398                         }
2399                 }
2400         }
2401
2402         /* default base */
2403         spec->base = 10;
2404         switch (*fmt) {
2405         case 'c':
2406                 spec->type = FORMAT_TYPE_CHAR;
2407                 return ++fmt - start;
2408
2409         case 's':
2410                 spec->type = FORMAT_TYPE_STR;
2411                 return ++fmt - start;
2412
2413         case 'p':
2414                 spec->type = FORMAT_TYPE_PTR;
2415                 return ++fmt - start;
2416
2417         case '%':
2418                 spec->type = FORMAT_TYPE_PERCENT_CHAR;
2419                 return ++fmt - start;
2420
2421         /* integer number formats - set up the flags and "break" */
2422         case 'o':
2423                 spec->base = 8;
2424                 break;
2425
2426         case 'x':
2427                 spec->flags |= SMALL;
2428                 /* fall through */
2429
2430         case 'X':
2431                 spec->base = 16;
2432                 break;
2433
2434         case 'd':
2435         case 'i':
2436                 spec->flags |= SIGN;
2437         case 'u':
2438                 break;
2439
2440         case 'n':
2441                 /*
2442                  * Since %n poses a greater security risk than
2443                  * utility, treat it as any other invalid or
2444                  * unsupported format specifier.
2445                  */
2446                 /* Fall-through */
2447
2448         default:
2449                 WARN_ONCE(1, "Please remove unsupported %%%c in format string\n", *fmt);
2450                 spec->type = FORMAT_TYPE_INVALID;
2451                 return fmt - start;
2452         }
2453
2454         if (qualifier == 'L')
2455                 spec->type = FORMAT_TYPE_LONG_LONG;
2456         else if (qualifier == 'l') {
2457                 BUILD_BUG_ON(FORMAT_TYPE_ULONG + SIGN != FORMAT_TYPE_LONG);
2458                 spec->type = FORMAT_TYPE_ULONG + (spec->flags & SIGN);
2459         } else if (qualifier == 'z') {
2460                 spec->type = FORMAT_TYPE_SIZE_T;
2461         } else if (qualifier == 't') {
2462                 spec->type = FORMAT_TYPE_PTRDIFF;
2463         } else if (qualifier == 'H') {
2464                 BUILD_BUG_ON(FORMAT_TYPE_UBYTE + SIGN != FORMAT_TYPE_BYTE);
2465                 spec->type = FORMAT_TYPE_UBYTE + (spec->flags & SIGN);
2466         } else if (qualifier == 'h') {
2467                 BUILD_BUG_ON(FORMAT_TYPE_USHORT + SIGN != FORMAT_TYPE_SHORT);
2468                 spec->type = FORMAT_TYPE_USHORT + (spec->flags & SIGN);
2469         } else {
2470                 BUILD_BUG_ON(FORMAT_TYPE_UINT + SIGN != FORMAT_TYPE_INT);
2471                 spec->type = FORMAT_TYPE_UINT + (spec->flags & SIGN);
2472         }
2473
2474         return ++fmt - start;
2475 }
2476
2477 static void
2478 set_field_width(struct printf_spec *spec, int width)
2479 {
2480         spec->field_width = width;
2481         if (WARN_ONCE(spec->field_width != width, "field width %d too large", width)) {
2482                 spec->field_width = clamp(width, -FIELD_WIDTH_MAX, FIELD_WIDTH_MAX);
2483         }
2484 }
2485
2486 static void
2487 set_precision(struct printf_spec *spec, int prec)
2488 {
2489         spec->precision = prec;
2490         if (WARN_ONCE(spec->precision != prec, "precision %d too large", prec)) {
2491                 spec->precision = clamp(prec, 0, PRECISION_MAX);
2492         }
2493 }
2494
2495 /**
2496  * vsnprintf - Format a string and place it in a buffer
2497  * @buf: The buffer to place the result into
2498  * @size: The size of the buffer, including the trailing null space
2499  * @fmt: The format string to use
2500  * @args: Arguments for the format string
2501  *
2502  * This function generally follows C99 vsnprintf, but has some
2503  * extensions and a few limitations:
2504  *
2505  *  - ``%n`` is unsupported
2506  *  - ``%p*`` is handled by pointer()
2507  *
2508  * See pointer() or Documentation/core-api/printk-formats.rst for more
2509  * extensive description.
2510  *
2511  * **Please update the documentation in both places when making changes**
2512  *
2513  * The return value is the number of characters which would
2514  * be generated for the given input, excluding the trailing
2515  * '\0', as per ISO C99. If you want to have the exact
2516  * number of characters written into @buf as return value
2517  * (not including the trailing '\0'), use vscnprintf(). If the
2518  * return is greater than or equal to @size, the resulting
2519  * string is truncated.
2520  *
2521  * If you're not already dealing with a va_list consider using snprintf().
2522  */
2523 int vsnprintf(char *buf, size_t size, const char *fmt, va_list args)
2524 {
2525         unsigned long long num;
2526         char *str, *end;
2527         struct printf_spec spec = {0};
2528
2529         /* Reject out-of-range values early.  Large positive sizes are
2530            used for unknown buffer sizes. */
2531         if (WARN_ON_ONCE(size > INT_MAX))
2532                 return 0;
2533
2534         str = buf;
2535         end = buf + size;
2536
2537         /* Make sure end is always >= buf */
2538         if (end < buf) {
2539                 end = ((void *)-1);
2540                 size = end - buf;
2541         }
2542
2543         while (*fmt) {
2544                 const char *old_fmt = fmt;
2545                 int read = format_decode(fmt, &spec);
2546
2547                 fmt += read;
2548
2549                 switch (spec.type) {
2550                 case FORMAT_TYPE_NONE: {
2551                         int copy = read;
2552                         if (str < end) {
2553                                 if (copy > end - str)
2554                                         copy = end - str;
2555                                 memcpy(str, old_fmt, copy);
2556                         }
2557                         str += read;
2558                         break;
2559                 }
2560
2561                 case FORMAT_TYPE_WIDTH:
2562                         set_field_width(&spec, va_arg(args, int));
2563                         break;
2564
2565                 case FORMAT_TYPE_PRECISION:
2566                         set_precision(&spec, va_arg(args, int));
2567                         break;
2568
2569                 case FORMAT_TYPE_CHAR: {
2570                         char c;
2571
2572                         if (!(spec.flags & LEFT)) {
2573                                 while (--spec.field_width > 0) {
2574                                         if (str < end)
2575                                                 *str = ' ';
2576                                         ++str;
2577
2578                                 }
2579                         }
2580                         c = (unsigned char) va_arg(args, int);
2581                         if (str < end)
2582                                 *str = c;
2583                         ++str;
2584                         while (--spec.field_width > 0) {
2585                                 if (str < end)
2586                                         *str = ' ';
2587                                 ++str;
2588                         }
2589                         break;
2590                 }
2591
2592                 case FORMAT_TYPE_STR:
2593                         str = string(str, end, va_arg(args, char *), spec);
2594                         break;
2595
2596                 case FORMAT_TYPE_PTR:
2597                         str = pointer(fmt, str, end, va_arg(args, void *),
2598                                       spec);
2599                         while (isalnum(*fmt))
2600                                 fmt++;
2601                         break;
2602
2603                 case FORMAT_TYPE_PERCENT_CHAR:
2604                         if (str < end)
2605                                 *str = '%';
2606                         ++str;
2607                         break;
2608
2609                 case FORMAT_TYPE_INVALID:
2610                         /*
2611                          * Presumably the arguments passed gcc's type
2612                          * checking, but there is no safe or sane way
2613                          * for us to continue parsing the format and
2614                          * fetching from the va_list; the remaining
2615                          * specifiers and arguments would be out of
2616                          * sync.
2617                          */
2618                         goto out;
2619
2620                 default:
2621                         switch (spec.type) {
2622                         case FORMAT_TYPE_LONG_LONG:
2623                                 num = va_arg(args, long long);
2624                                 break;
2625                         case FORMAT_TYPE_ULONG:
2626                                 num = va_arg(args, unsigned long);
2627                                 break;
2628                         case FORMAT_TYPE_LONG:
2629                                 num = va_arg(args, long);
2630                                 break;
2631                         case FORMAT_TYPE_SIZE_T:
2632                                 if (spec.flags & SIGN)
2633                                         num = va_arg(args, ssize_t);
2634                                 else
2635                                         num = va_arg(args, size_t);
2636                                 break;
2637                         case FORMAT_TYPE_PTRDIFF:
2638                                 num = va_arg(args, ptrdiff_t);
2639                                 break;
2640                         case FORMAT_TYPE_UBYTE:
2641                                 num = (unsigned char) va_arg(args, int);
2642                                 break;
2643                         case FORMAT_TYPE_BYTE:
2644                                 num = (signed char) va_arg(args, int);
2645                                 break;
2646                         case FORMAT_TYPE_USHORT:
2647                                 num = (unsigned short) va_arg(args, int);
2648                                 break;
2649                         case FORMAT_TYPE_SHORT:
2650                                 num = (short) va_arg(args, int);
2651                                 break;
2652                         case FORMAT_TYPE_INT:
2653                                 num = (int) va_arg(args, int);
2654                                 break;
2655                         default:
2656                                 num = va_arg(args, unsigned int);
2657                         }
2658
2659                         str = number(str, end, num, spec);
2660                 }
2661         }
2662
2663 out:
2664         if (size > 0) {
2665                 if (str < end)
2666                         *str = '\0';
2667                 else
2668                         end[-1] = '\0';
2669         }
2670
2671         /* the trailing null byte doesn't count towards the total */
2672         return str-buf;
2673
2674 }
2675 EXPORT_SYMBOL(vsnprintf);
2676
2677 /**
2678  * vscnprintf - Format a string and place it in a buffer
2679  * @buf: The buffer to place the result into
2680  * @size: The size of the buffer, including the trailing null space
2681  * @fmt: The format string to use
2682  * @args: Arguments for the format string
2683  *
2684  * The return value is the number of characters which have been written into
2685  * the @buf not including the trailing '\0'. If @size is == 0 the function
2686  * returns 0.
2687  *
2688  * If you're not already dealing with a va_list consider using scnprintf().
2689  *
2690  * See the vsnprintf() documentation for format string extensions over C99.
2691  */
2692 int vscnprintf(char *buf, size_t size, const char *fmt, va_list args)
2693 {
2694         int i;
2695
2696         i = vsnprintf(buf, size, fmt, args);
2697
2698         if (likely(i < size))
2699                 return i;
2700         if (size != 0)
2701                 return size - 1;
2702         return 0;
2703 }
2704 EXPORT_SYMBOL(vscnprintf);
2705
2706 /**
2707  * snprintf - Format a string and place it in a buffer
2708  * @buf: The buffer to place the result into
2709  * @size: The size of the buffer, including the trailing null space
2710  * @fmt: The format string to use
2711  * @...: Arguments for the format string
2712  *
2713  * The return value is the number of characters which would be
2714  * generated for the given input, excluding the trailing null,
2715  * as per ISO C99.  If the return is greater than or equal to
2716  * @size, the resulting string is truncated.
2717  *
2718  * See the vsnprintf() documentation for format string extensions over C99.
2719  */
2720 int snprintf(char *buf, size_t size, const char *fmt, ...)
2721 {
2722         va_list args;
2723         int i;
2724
2725         va_start(args, fmt);
2726         i = vsnprintf(buf, size, fmt, args);
2727         va_end(args);
2728
2729         return i;
2730 }
2731 EXPORT_SYMBOL(snprintf);
2732
2733 /**
2734  * scnprintf - Format a string and place it in a buffer
2735  * @buf: The buffer to place the result into
2736  * @size: The size of the buffer, including the trailing null space
2737  * @fmt: The format string to use
2738  * @...: Arguments for the format string
2739  *
2740  * The return value is the number of characters written into @buf not including
2741  * the trailing '\0'. If @size is == 0 the function returns 0.
2742  */
2743
2744 int scnprintf(char *buf, size_t size, const char *fmt, ...)
2745 {
2746         va_list args;
2747         int i;
2748
2749         va_start(args, fmt);
2750         i = vscnprintf(buf, size, fmt, args);
2751         va_end(args);
2752
2753         return i;
2754 }
2755 EXPORT_SYMBOL(scnprintf);
2756
2757 /**
2758  * vsprintf - Format a string and place it in a buffer
2759  * @buf: The buffer to place the result into
2760  * @fmt: The format string to use
2761  * @args: Arguments for the format string
2762  *
2763  * The function returns the number of characters written
2764  * into @buf. Use vsnprintf() or vscnprintf() in order to avoid
2765  * buffer overflows.
2766  *
2767  * If you're not already dealing with a va_list consider using sprintf().
2768  *
2769  * See the vsnprintf() documentation for format string extensions over C99.
2770  */
2771 int vsprintf(char *buf, const char *fmt, va_list args)
2772 {
2773         return vsnprintf(buf, INT_MAX, fmt, args);
2774 }
2775 EXPORT_SYMBOL(vsprintf);
2776
2777 /**
2778  * sprintf - Format a string and place it in a buffer
2779  * @buf: The buffer to place the result into
2780  * @fmt: The format string to use
2781  * @...: Arguments for the format string
2782  *
2783  * The function returns the number of characters written
2784  * into @buf. Use snprintf() or scnprintf() in order to avoid
2785  * buffer overflows.
2786  *
2787  * See the vsnprintf() documentation for format string extensions over C99.
2788  */
2789 int sprintf(char *buf, const char *fmt, ...)
2790 {
2791         va_list args;
2792         int i;
2793
2794         va_start(args, fmt);
2795         i = vsnprintf(buf, INT_MAX, fmt, args);
2796         va_end(args);
2797
2798         return i;
2799 }
2800 EXPORT_SYMBOL(sprintf);
2801
2802 #ifdef CONFIG_BINARY_PRINTF
2803 /*
2804  * bprintf service:
2805  * vbin_printf() - VA arguments to binary data
2806  * bstr_printf() - Binary data to text string
2807  */
2808
2809 /**
2810  * vbin_printf - Parse a format string and place args' binary value in a buffer
2811  * @bin_buf: The buffer to place args' binary value
2812  * @size: The size of the buffer(by words(32bits), not characters)
2813  * @fmt: The format string to use
2814  * @args: Arguments for the format string
2815  *
2816  * The format follows C99 vsnprintf, except %n is ignored, and its argument
2817  * is skipped.
2818  *
2819  * The return value is the number of words(32bits) which would be generated for
2820  * the given input.
2821  *
2822  * NOTE:
2823  * If the return value is greater than @size, the resulting bin_buf is NOT
2824  * valid for bstr_printf().
2825  */
2826 int vbin_printf(u32 *bin_buf, size_t size, const char *fmt, va_list args)
2827 {
2828         struct printf_spec spec = {0};
2829         char *str, *end;
2830         int width;
2831
2832         str = (char *)bin_buf;
2833         end = (char *)(bin_buf + size);
2834
2835 #define save_arg(type)                                                  \
2836 ({                                                                      \
2837         unsigned long long value;                                       \
2838         if (sizeof(type) == 8) {                                        \
2839                 unsigned long long val8;                                \
2840                 str = PTR_ALIGN(str, sizeof(u32));                      \
2841                 val8 = va_arg(args, unsigned long long);                \
2842                 if (str + sizeof(type) <= end) {                        \
2843                         *(u32 *)str = *(u32 *)&val8;                    \
2844                         *(u32 *)(str + 4) = *((u32 *)&val8 + 1);        \
2845                 }                                                       \
2846                 value = val8;                                           \
2847         } else {                                                        \
2848                 unsigned int val4;                                      \
2849                 str = PTR_ALIGN(str, sizeof(type));                     \
2850                 val4 = va_arg(args, int);                               \
2851                 if (str + sizeof(type) <= end)                          \
2852                         *(typeof(type) *)str = (type)(long)val4;        \
2853                 value = (unsigned long long)val4;                       \
2854         }                                                               \
2855         str += sizeof(type);                                            \
2856         value;                                                          \
2857 })
2858
2859         while (*fmt) {
2860                 int read = format_decode(fmt, &spec);
2861
2862                 fmt += read;
2863
2864                 switch (spec.type) {
2865                 case FORMAT_TYPE_NONE:
2866                 case FORMAT_TYPE_PERCENT_CHAR:
2867                         break;
2868                 case FORMAT_TYPE_INVALID:
2869                         goto out;
2870
2871                 case FORMAT_TYPE_WIDTH:
2872                 case FORMAT_TYPE_PRECISION:
2873                         width = (int)save_arg(int);
2874                         /* Pointers may require the width */
2875                         if (*fmt == 'p')
2876                                 set_field_width(&spec, width);
2877                         break;
2878
2879                 case FORMAT_TYPE_CHAR:
2880                         save_arg(char);
2881                         break;
2882
2883                 case FORMAT_TYPE_STR: {
2884                         const char *save_str = va_arg(args, char *);
2885                         const char *err_msg;
2886                         size_t len;
2887
2888                         err_msg = check_pointer_msg(save_str);
2889                         if (err_msg)
2890                                 save_str = err_msg;
2891
2892                         len = strlen(save_str) + 1;
2893                         if (str + len < end)
2894                                 memcpy(str, save_str, len);
2895                         str += len;
2896                         break;
2897                 }
2898
2899                 case FORMAT_TYPE_PTR:
2900                         /* Dereferenced pointers must be done now */
2901                         switch (*fmt) {
2902                         /* Dereference of functions is still OK */
2903                         case 'S':
2904                         case 's':
2905                         case 'x':
2906                         case 'K':
2907                         case 'e':
2908                                 save_arg(void *);
2909                                 break;
2910                         default:
2911                                 if (!isalnum(*fmt)) {
2912                                         save_arg(void *);
2913                                         break;
2914                                 }
2915                                 str = pointer(fmt, str, end, va_arg(args, void *),
2916                                               spec);
2917                                 if (str + 1 < end)
2918                                         *str++ = '\0';
2919                                 else
2920                                         end[-1] = '\0'; /* Must be nul terminated */
2921                         }
2922                         /* skip all alphanumeric pointer suffixes */
2923                         while (isalnum(*fmt))
2924                                 fmt++;
2925                         break;
2926
2927                 default:
2928                         switch (spec.type) {
2929
2930                         case FORMAT_TYPE_LONG_LONG:
2931                                 save_arg(long long);
2932                                 break;
2933                         case FORMAT_TYPE_ULONG:
2934                         case FORMAT_TYPE_LONG:
2935                                 save_arg(unsigned long);
2936                                 break;
2937                         case FORMAT_TYPE_SIZE_T:
2938                                 save_arg(size_t);
2939                                 break;
2940                         case FORMAT_TYPE_PTRDIFF:
2941                                 save_arg(ptrdiff_t);
2942                                 break;
2943                         case FORMAT_TYPE_UBYTE:
2944                         case FORMAT_TYPE_BYTE:
2945                                 save_arg(char);
2946                                 break;
2947                         case FORMAT_TYPE_USHORT:
2948                         case FORMAT_TYPE_SHORT:
2949                                 save_arg(short);
2950                                 break;
2951                         default:
2952                                 save_arg(int);
2953                         }
2954                 }
2955         }
2956
2957 out:
2958         return (u32 *)(PTR_ALIGN(str, sizeof(u32))) - bin_buf;
2959 #undef save_arg
2960 }
2961 EXPORT_SYMBOL_GPL(vbin_printf);
2962
2963 /**
2964  * bstr_printf - Format a string from binary arguments and place it in a buffer
2965  * @buf: The buffer to place the result into
2966  * @size: The size of the buffer, including the trailing null space
2967  * @fmt: The format string to use
2968  * @bin_buf: Binary arguments for the format string
2969  *
2970  * This function like C99 vsnprintf, but the difference is that vsnprintf gets
2971  * arguments from stack, and bstr_printf gets arguments from @bin_buf which is
2972  * a binary buffer that generated by vbin_printf.
2973  *
2974  * The format follows C99 vsnprintf, but has some extensions:
2975  *  see vsnprintf comment for details.
2976  *
2977  * The return value is the number of characters which would
2978  * be generated for the given input, excluding the trailing
2979  * '\0', as per ISO C99. If you want to have the exact
2980  * number of characters written into @buf as return value
2981  * (not including the trailing '\0'), use vscnprintf(). If the
2982  * return is greater than or equal to @size, the resulting
2983  * string is truncated.
2984  */
2985 int bstr_printf(char *buf, size_t size, const char *fmt, const u32 *bin_buf)
2986 {
2987         struct printf_spec spec = {0};
2988         char *str, *end;
2989         const char *args = (const char *)bin_buf;
2990
2991         if (WARN_ON_ONCE(size > INT_MAX))
2992                 return 0;
2993
2994         str = buf;
2995         end = buf + size;
2996
2997 #define get_arg(type)                                                   \
2998 ({                                                                      \
2999         typeof(type) value;                                             \
3000         if (sizeof(type) == 8) {                                        \
3001                 args = PTR_ALIGN(args, sizeof(u32));                    \
3002                 *(u32 *)&value = *(u32 *)args;                          \
3003                 *((u32 *)&value + 1) = *(u32 *)(args + 4);              \
3004         } else {                                                        \
3005                 args = PTR_ALIGN(args, sizeof(type));                   \
3006                 value = *(typeof(type) *)args;                          \
3007         }                                                               \
3008         args += sizeof(type);                                           \
3009         value;                                                          \
3010 })
3011
3012         /* Make sure end is always >= buf */
3013         if (end < buf) {
3014                 end = ((void *)-1);
3015                 size = end - buf;
3016         }
3017
3018         while (*fmt) {
3019                 const char *old_fmt = fmt;
3020                 int read = format_decode(fmt, &spec);
3021
3022                 fmt += read;
3023
3024                 switch (spec.type) {
3025                 case FORMAT_TYPE_NONE: {
3026                         int copy = read;
3027                         if (str < end) {
3028                                 if (copy > end - str)
3029                                         copy = end - str;
3030                                 memcpy(str, old_fmt, copy);
3031                         }
3032                         str += read;
3033                         break;
3034                 }
3035
3036                 case FORMAT_TYPE_WIDTH:
3037                         set_field_width(&spec, get_arg(int));
3038                         break;
3039
3040                 case FORMAT_TYPE_PRECISION:
3041                         set_precision(&spec, get_arg(int));
3042                         break;
3043
3044                 case FORMAT_TYPE_CHAR: {
3045                         char c;
3046
3047                         if (!(spec.flags & LEFT)) {
3048                                 while (--spec.field_width > 0) {
3049                                         if (str < end)
3050                                                 *str = ' ';
3051                                         ++str;
3052                                 }
3053                         }
3054                         c = (unsigned char) get_arg(char);
3055                         if (str < end)
3056                                 *str = c;
3057                         ++str;
3058                         while (--spec.field_width > 0) {
3059                                 if (str < end)
3060                                         *str = ' ';
3061                                 ++str;
3062                         }
3063                         break;
3064                 }
3065
3066                 case FORMAT_TYPE_STR: {
3067                         const char *str_arg = args;
3068                         args += strlen(str_arg) + 1;
3069                         str = string(str, end, (char *)str_arg, spec);
3070                         break;
3071                 }
3072
3073                 case FORMAT_TYPE_PTR: {
3074                         bool process = false;
3075                         int copy, len;
3076                         /* Non function dereferences were already done */
3077                         switch (*fmt) {
3078                         case 'S':
3079                         case 's':
3080                         case 'F':
3081                         case 'f':
3082                         case 'x':
3083                         case 'K':
3084                         case 'e':
3085                                 process = true;
3086                                 break;
3087                         default:
3088                                 if (!isalnum(*fmt)) {
3089                                         process = true;
3090                                         break;
3091                                 }
3092                                 /* Pointer dereference was already processed */
3093                                 if (str < end) {
3094                                         len = copy = strlen(args);
3095                                         if (copy > end - str)
3096                                                 copy = end - str;
3097                                         memcpy(str, args, copy);
3098                                         str += len;
3099                                         args += len + 1;
3100                                 }
3101                         }
3102                         if (process)
3103                                 str = pointer(fmt, str, end, get_arg(void *), spec);
3104
3105                         while (isalnum(*fmt))
3106                                 fmt++;
3107                         break;
3108                 }
3109
3110                 case FORMAT_TYPE_PERCENT_CHAR:
3111                         if (str < end)
3112                                 *str = '%';
3113                         ++str;
3114                         break;
3115
3116                 case FORMAT_TYPE_INVALID:
3117                         goto out;
3118
3119                 default: {
3120                         unsigned long long num;
3121
3122                         switch (spec.type) {
3123
3124                         case FORMAT_TYPE_LONG_LONG:
3125                                 num = get_arg(long long);
3126                                 break;
3127                         case FORMAT_TYPE_ULONG:
3128                         case FORMAT_TYPE_LONG:
3129                                 num = get_arg(unsigned long);
3130                                 break;
3131                         case FORMAT_TYPE_SIZE_T:
3132                                 num = get_arg(size_t);
3133                                 break;
3134                         case FORMAT_TYPE_PTRDIFF:
3135                                 num = get_arg(ptrdiff_t);
3136                                 break;
3137                         case FORMAT_TYPE_UBYTE:
3138                                 num = get_arg(unsigned char);
3139                                 break;
3140                         case FORMAT_TYPE_BYTE:
3141                                 num = get_arg(signed char);
3142                                 break;
3143                         case FORMAT_TYPE_USHORT:
3144                                 num = get_arg(unsigned short);
3145                                 break;
3146                         case FORMAT_TYPE_SHORT:
3147                                 num = get_arg(short);
3148                                 break;
3149                         case FORMAT_TYPE_UINT:
3150                                 num = get_arg(unsigned int);
3151                                 break;
3152                         default:
3153                                 num = get_arg(int);
3154                         }
3155
3156                         str = number(str, end, num, spec);
3157                 } /* default: */
3158                 } /* switch(spec.type) */
3159         } /* while(*fmt) */
3160
3161 out:
3162         if (size > 0) {
3163                 if (str < end)
3164                         *str = '\0';
3165                 else
3166                         end[-1] = '\0';
3167         }
3168
3169 #undef get_arg
3170
3171         /* the trailing null byte doesn't count towards the total */
3172         return str - buf;
3173 }
3174 EXPORT_SYMBOL_GPL(bstr_printf);
3175
3176 /**
3177  * bprintf - Parse a format string and place args' binary value in a buffer
3178  * @bin_buf: The buffer to place args' binary value
3179  * @size: The size of the buffer(by words(32bits), not characters)
3180  * @fmt: The format string to use
3181  * @...: Arguments for the format string
3182  *
3183  * The function returns the number of words(u32) written
3184  * into @bin_buf.
3185  */
3186 int bprintf(u32 *bin_buf, size_t size, const char *fmt, ...)
3187 {
3188         va_list args;
3189         int ret;
3190
3191         va_start(args, fmt);
3192         ret = vbin_printf(bin_buf, size, fmt, args);
3193         va_end(args);
3194
3195         return ret;
3196 }
3197 EXPORT_SYMBOL_GPL(bprintf);
3198
3199 #endif /* CONFIG_BINARY_PRINTF */
3200
3201 /**
3202  * vsscanf - Unformat a buffer into a list of arguments
3203  * @buf:        input buffer
3204  * @fmt:        format of buffer
3205  * @args:       arguments
3206  */
3207 int vsscanf(const char *buf, const char *fmt, va_list args)
3208 {
3209         const char *str = buf;
3210         char *next;
3211         char digit;
3212         int num = 0;
3213         u8 qualifier;
3214         unsigned int base;
3215         union {
3216                 long long s;
3217                 unsigned long long u;
3218         } val;
3219         s16 field_width;
3220         bool is_sign;
3221
3222         while (*fmt) {
3223                 /* skip any white space in format */
3224                 /* white space in format matchs any amount of
3225                  * white space, including none, in the input.
3226                  */
3227                 if (isspace(*fmt)) {
3228                         fmt = skip_spaces(++fmt);
3229                         str = skip_spaces(str);
3230                 }
3231
3232                 /* anything that is not a conversion must match exactly */
3233                 if (*fmt != '%' && *fmt) {
3234                         if (*fmt++ != *str++)
3235                                 break;
3236                         continue;
3237                 }
3238
3239                 if (!*fmt)
3240                         break;
3241                 ++fmt;
3242
3243                 /* skip this conversion.
3244                  * advance both strings to next white space
3245                  */
3246                 if (*fmt == '*') {
3247                         if (!*str)
3248                                 break;
3249                         while (!isspace(*fmt) && *fmt != '%' && *fmt) {
3250                                 /* '%*[' not yet supported, invalid format */
3251                                 if (*fmt == '[')
3252                                         return num;
3253                                 fmt++;
3254                         }
3255                         while (!isspace(*str) && *str)
3256                                 str++;
3257                         continue;
3258                 }
3259
3260                 /* get field width */
3261                 field_width = -1;
3262                 if (isdigit(*fmt)) {
3263                         field_width = skip_atoi(&fmt);
3264                         if (field_width <= 0)
3265                                 break;
3266                 }
3267
3268                 /* get conversion qualifier */
3269                 qualifier = -1;
3270                 if (*fmt == 'h' || _tolower(*fmt) == 'l' ||
3271                     *fmt == 'z') {
3272                         qualifier = *fmt++;
3273                         if (unlikely(qualifier == *fmt)) {
3274                                 if (qualifier == 'h') {
3275                                         qualifier = 'H';
3276                                         fmt++;
3277                                 } else if (qualifier == 'l') {
3278                                         qualifier = 'L';
3279                                         fmt++;
3280                                 }
3281                         }
3282                 }
3283
3284                 if (!*fmt)
3285                         break;
3286
3287                 if (*fmt == 'n') {
3288                         /* return number of characters read so far */
3289                         *va_arg(args, int *) = str - buf;
3290                         ++fmt;
3291                         continue;
3292                 }
3293
3294                 if (!*str)
3295                         break;
3296
3297                 base = 10;
3298                 is_sign = false;
3299
3300                 switch (*fmt++) {
3301                 case 'c':
3302                 {
3303                         char *s = (char *)va_arg(args, char*);
3304                         if (field_width == -1)
3305                                 field_width = 1;
3306                         do {
3307                                 *s++ = *str++;
3308                         } while (--field_width > 0 && *str);
3309                         num++;
3310                 }
3311                 continue;
3312                 case 's':
3313                 {
3314                         char *s = (char *)va_arg(args, char *);
3315                         if (field_width == -1)
3316                                 field_width = SHRT_MAX;
3317                         /* first, skip leading white space in buffer */
3318                         str = skip_spaces(str);
3319
3320                         /* now copy until next white space */
3321                         while (*str && !isspace(*str) && field_width--)
3322                                 *s++ = *str++;
3323                         *s = '\0';
3324                         num++;
3325                 }
3326                 continue;
3327                 /*
3328                  * Warning: This implementation of the '[' conversion specifier
3329                  * deviates from its glibc counterpart in the following ways:
3330                  * (1) It does NOT support ranges i.e. '-' is NOT a special
3331                  *     character
3332                  * (2) It cannot match the closing bracket ']' itself
3333                  * (3) A field width is required
3334                  * (4) '%*[' (discard matching input) is currently not supported
3335                  *
3336                  * Example usage:
3337                  * ret = sscanf("00:0a:95","%2[^:]:%2[^:]:%2[^:]",
3338                  *              buf1, buf2, buf3);
3339                  * if (ret < 3)
3340                  *    // etc..
3341                  */
3342                 case '[':
3343                 {
3344                         char *s = (char *)va_arg(args, char *);
3345                         DECLARE_BITMAP(set, 256) = {0};
3346                         unsigned int len = 0;
3347                         bool negate = (*fmt == '^');
3348
3349                         /* field width is required */
3350                         if (field_width == -1)
3351                                 return num;
3352
3353                         if (negate)
3354                                 ++fmt;
3355
3356                         for ( ; *fmt && *fmt != ']'; ++fmt, ++len)
3357                                 set_bit((u8)*fmt, set);
3358
3359                         /* no ']' or no character set found */
3360                         if (!*fmt || !len)
3361                                 return num;
3362                         ++fmt;
3363
3364                         if (negate) {
3365                                 bitmap_complement(set, set, 256);
3366                                 /* exclude null '\0' byte */
3367                                 clear_bit(0, set);
3368                         }
3369
3370                         /* match must be non-empty */
3371                         if (!test_bit((u8)*str, set))
3372                                 return num;
3373
3374                         while (test_bit((u8)*str, set) && field_width--)
3375                                 *s++ = *str++;
3376                         *s = '\0';
3377                         ++num;
3378                 }
3379                 continue;
3380                 case 'o':
3381                         base = 8;
3382                         break;
3383                 case 'x':
3384                 case 'X':
3385                         base = 16;
3386                         break;
3387                 case 'i':
3388                         base = 0;
3389                         /* fall through */
3390                 case 'd':
3391                         is_sign = true;
3392                         /* fall through */
3393                 case 'u':
3394                         break;
3395                 case '%':
3396                         /* looking for '%' in str */
3397                         if (*str++ != '%')
3398                                 return num;
3399                         continue;
3400                 default:
3401                         /* invalid format; stop here */
3402                         return num;
3403                 }
3404
3405                 /* have some sort of integer conversion.
3406                  * first, skip white space in buffer.
3407                  */
3408                 str = skip_spaces(str);
3409
3410                 digit = *str;
3411                 if (is_sign && digit == '-')
3412                         digit = *(str + 1);
3413
3414                 if (!digit
3415                     || (base == 16 && !isxdigit(digit))
3416                     || (base == 10 && !isdigit(digit))
3417                     || (base == 8 && (!isdigit(digit) || digit > '7'))
3418                     || (base == 0 && !isdigit(digit)))
3419                         break;
3420
3421                 if (is_sign)
3422                         val.s = qualifier != 'L' ?
3423                                 simple_strtol(str, &next, base) :
3424                                 simple_strtoll(str, &next, base);
3425                 else
3426                         val.u = qualifier != 'L' ?
3427                                 simple_strtoul(str, &next, base) :
3428                                 simple_strtoull(str, &next, base);
3429
3430                 if (field_width > 0 && next - str > field_width) {
3431                         if (base == 0)
3432                                 _parse_integer_fixup_radix(str, &base);
3433                         while (next - str > field_width) {
3434                                 if (is_sign)
3435                                         val.s = div_s64(val.s, base);
3436                                 else
3437                                         val.u = div_u64(val.u, base);
3438                                 --next;
3439                         }
3440                 }
3441
3442                 switch (qualifier) {
3443                 case 'H':       /* that's 'hh' in format */
3444                         if (is_sign)
3445                                 *va_arg(args, signed char *) = val.s;
3446                         else
3447                                 *va_arg(args, unsigned char *) = val.u;
3448                         break;
3449                 case 'h':
3450                         if (is_sign)
3451                                 *va_arg(args, short *) = val.s;
3452                         else
3453                                 *va_arg(args, unsigned short *) = val.u;
3454                         break;
3455                 case 'l':
3456                         if (is_sign)
3457                                 *va_arg(args, long *) = val.s;
3458                         else
3459                                 *va_arg(args, unsigned long *) = val.u;
3460                         break;
3461                 case 'L':
3462                         if (is_sign)
3463                                 *va_arg(args, long long *) = val.s;
3464                         else
3465                                 *va_arg(args, unsigned long long *) = val.u;
3466                         break;
3467                 case 'z':
3468                         *va_arg(args, size_t *) = val.u;
3469                         break;
3470                 default:
3471                         if (is_sign)
3472                                 *va_arg(args, int *) = val.s;
3473                         else
3474                                 *va_arg(args, unsigned int *) = val.u;
3475                         break;
3476                 }
3477                 num++;
3478
3479                 if (!next)
3480                         break;
3481                 str = next;
3482         }
3483
3484         return num;
3485 }
3486 EXPORT_SYMBOL(vsscanf);
3487
3488 /**
3489  * sscanf - Unformat a buffer into a list of arguments
3490  * @buf:        input buffer
3491  * @fmt:        formatting of buffer
3492  * @...:        resulting arguments
3493  */
3494 int sscanf(const char *buf, const char *fmt, ...)
3495 {
3496         va_list args;
3497         int i;
3498
3499         va_start(args, fmt);
3500         i = vsscanf(buf, fmt, args);
3501         va_end(args);
3502
3503         return i;
3504 }
3505 EXPORT_SYMBOL(sscanf);