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  61  * This function is obsolete.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         /* When debugging early boot use non-cryptographically secure hash. */
 798         if (unlikely(debug_boot_weak_hash)) {
 799                 hashval = hash_long((unsigned long)ptr, 32);
 800                 return pointer_string(buf, end, (const void *)hashval, spec);
 801         }
 802
 803         ret = __ptr_to_hashval(ptr, &hashval);
 804         if (ret) {
 805                 spec.field_width = 2 * sizeof(ptr);
 806                 /* string length must be less than default_width */
 807                 return error_string(buf, end, str, spec);
 808         }
 809
 810         return pointer_string(buf, end, (const void *)hashval, spec);
 811 }
 812
 813 int kptr_restrict __read_mostly;
 814
 815 static noinline_for_stack
 816 char *restricted_pointer(char *buf, char *end, const void *ptr,
 817                          struct printf_spec spec)
 818 {
 819         switch (kptr_restrict) {
 820         case 0:
 821                 /* Handle as %p, hash and do _not_ leak addresses. */
 822                 return ptr_to_id(buf, end, ptr, spec);
 823         case 1: {
 824                 const struct cred *cred;
 825
 826                 /*
 827                  * kptr_restrict==1 cannot be used in IRQ context
 828                  * because its test for CAP_SYSLOG would be meaningless.
 829                  */
 830                 if (in_irq() || in_serving_softirq() || in_nmi()) {
 831                         if (spec.field_width == -1)
 832                                 spec.field_width = 2 * sizeof(ptr);
 833                         return error_string(buf, end, "pK-error", spec);
 834                 }
 835
 836                 /*
 837                  * Only print the real pointer value if the current
 838                  * process has CAP_SYSLOG and is running with the
 839                  * same credentials it started with. This is because
 840                  * access to files is checked at open() time, but %pK
 841                  * checks permission at read() time. We don't want to
 842                  * leak pointer values if a binary opens a file using
 843                  * %pK and then elevates privileges before reading it.
 844                  */
 845                 cred = current_cred();
 846                 if (!has_capability_noaudit(current, CAP_SYSLOG) ||
 847                     !uid_eq(cred->euid, cred->uid) ||
 848                     !gid_eq(cred->egid, cred->gid))
 849                         ptr = NULL;
 850                 break;
 851         }
 852         case 2:
 853         default:
 854                 /* Always print 0's for %pK */
 855                 ptr = NULL;
 856                 break;
 857         }
 858
 859         return pointer_string(buf, end, ptr, spec);
 860 }
 861
 862 static noinline_for_stack
 863 char *dentry_name(char *buf, char *end, const struct dentry *d, struct printf_spec spec,
 864                   const char *fmt)
 865 {
 866         const char *array[4], *s;
 867         const struct dentry *p;
 868         int depth;
 869         int i, n;
 870
 871         switch (fmt[1]) {
 872                 case '2': case '3': case '4':
 873                         depth = fmt[1] - '0';
 874                         break;
 875                 default:
 876                         depth = 1;
 877         }
 878
 879         rcu_read_lock();
 880         for (i = 0; i < depth; i++, d = p) {
 881                 if (check_pointer(&buf, end, d, spec)) {
 882                         rcu_read_unlock();
 883                         return buf;
 884                 }
 885
 886                 p = READ_ONCE(d->d_parent);
 887                 array[i] = READ_ONCE(d->d_name.name);
 888                 if (p == d) {
 889                         if (i)
 890                                 array[i] = "";
 891                         i++;
 892                         break;
 893                 }
 894         }
 895         s = array[--i];
 896         for (n = 0; n != spec.precision; n++, buf++) {
 897                 char c = *s++;
 898                 if (!c) {
 899                         if (!i)
 900                                 break;
 901                         c = '/';
 902                         s = array[--i];
 903                 }
 904                 if (buf < end)
 905                         *buf = c;
 906         }
 907         rcu_read_unlock();
 908         return widen_string(buf, n, end, spec);
 909 }
 910
 911 static noinline_for_stack
 912 char *file_dentry_name(char *buf, char *end, const struct file *f,
 913                         struct printf_spec spec, const char *fmt)
 914 {
 915         if (check_pointer(&buf, end, f, spec))
 916                 return buf;
 917
 918         return dentry_name(buf, end, f->f_path.dentry, spec, fmt);
 919 }
 920 #ifdef CONFIG_BLOCK
 921 static noinline_for_stack
 922 char *bdev_name(char *buf, char *end, struct block_device *bdev,
 923                 struct printf_spec spec, const char *fmt)
 924 {
 925         struct gendisk *hd;
 926
 927         if (check_pointer(&buf, end, bdev, spec))
 928                 return buf;
 929
 930         hd = bdev->bd_disk;
 931         buf = string(buf, end, hd->disk_name, spec);
 932         if (bdev->bd_part->partno) {
 933                 if (isdigit(hd->disk_name[strlen(hd->disk_name)-1])) {
 934                         if (buf < end)
 935                                 *buf = 'p';
 936                         buf++;
 937                 }
 938                 buf = number(buf, end, bdev->bd_part->partno, spec);
 939         }
 940         return buf;
 941 }
 942 #endif
 943
 944 static noinline_for_stack
 945 char *symbol_string(char *buf, char *end, void *ptr,
 946                     struct printf_spec spec, const char *fmt)
 947 {
 948         unsigned long value;
 949 #ifdef CONFIG_KALLSYMS
 950         char sym[KSYM_SYMBOL_LEN];
 951 #endif
 952
 953         if (fmt[1] == 'R')
 954                 ptr = __builtin_extract_return_addr(ptr);
 955         value = (unsigned long)ptr;
 956
 957 #ifdef CONFIG_KALLSYMS
 958         if (*fmt == 'B')
 959                 sprint_backtrace(sym, value);
 960         else if (*fmt != 's')
 961                 sprint_symbol(sym, value);
 962         else
 963                 sprint_symbol_no_offset(sym, value);
 964
 965         return string_nocheck(buf, end, sym, spec);
 966 #else
 967         return special_hex_number(buf, end, value, sizeof(void *));
 968 #endif
 969 }
 970
 971 static const struct printf_spec default_str_spec = {
 972         .field_width = -1,
 973         .precision = -1,
 974 };
 975
 976 static const struct printf_spec default_flag_spec = {
 977         .base = 16,
 978         .precision = -1,
 979         .flags = SPECIAL | SMALL,
 980 };
 981
 982 static const struct printf_spec default_dec_spec = {
 983         .base = 10,
 984         .precision = -1,
 985 };
 986
 987 static const struct printf_spec default_dec02_spec = {
 988         .base = 10,
 989         .field_width = 2,
 990         .precision = -1,
 991         .flags = ZEROPAD,
 992 };
 993
 994 static const struct printf_spec default_dec04_spec = {
 995         .base = 10,
 996         .field_width = 4,
 997         .precision = -1,
 998         .flags = ZEROPAD,
 999 };
1000
1001 static noinline_for_stack
1002 char *resource_string(char *buf, char *end, struct resource *res,
1003                       struct printf_spec spec, const char *fmt)
1004 {
1005 #ifndef IO_RSRC_PRINTK_SIZE
1006 #define IO_RSRC_PRINTK_SIZE     6
1007 #endif
1008
1009 #ifndef MEM_RSRC_PRINTK_SIZE
1010 #define MEM_RSRC_PRINTK_SIZE    10
1011 #endif
1012         static const struct printf_spec io_spec = {
1013                 .base = 16,
1014                 .field_width = IO_RSRC_PRINTK_SIZE,
1015                 .precision = -1,
1016                 .flags = SPECIAL | SMALL | ZEROPAD,
1017         };
1018         static const struct printf_spec mem_spec = {
1019                 .base = 16,
1020                 .field_width = MEM_RSRC_PRINTK_SIZE,
1021                 .precision = -1,
1022                 .flags = SPECIAL | SMALL | ZEROPAD,
1023         };
1024         static const struct printf_spec bus_spec = {
1025                 .base = 16,
1026                 .field_width = 2,
1027                 .precision = -1,
1028                 .flags = SMALL | ZEROPAD,
1029         };
1030         static const struct printf_spec str_spec = {
1031                 .field_width = -1,
1032                 .precision = 10,
1033                 .flags = LEFT,
1034         };
1035
1036         /* 32-bit res (sizeof==4): 10 chars in dec, 10 in hex ("0x" + 8)
1037          * 64-bit res (sizeof==8): 20 chars in dec, 18 in hex ("0x" + 16) */
1038 #define RSRC_BUF_SIZE           ((2 * sizeof(resource_size_t)) + 4)
1039 #define FLAG_BUF_SIZE           (2 * sizeof(res->flags))
1040 #define DECODED_BUF_SIZE        sizeof("[mem - 64bit pref window disabled]")
1041 #define RAW_BUF_SIZE            sizeof("[mem - flags 0x]")
1042         char sym[max(2*RSRC_BUF_SIZE + DECODED_BUF_SIZE,
1043                      2*RSRC_BUF_SIZE + FLAG_BUF_SIZE + RAW_BUF_SIZE)];
1044
1045         char *p = sym, *pend = sym + sizeof(sym);
1046         int decode = (fmt[0] == 'R') ? 1 : 0;
1047         const struct printf_spec *specp;
1048
1049         if (check_pointer(&buf, end, res, spec))
1050                 return buf;
1051
1052         *p++ = '[';
1053         if (res->flags & IORESOURCE_IO) {
1054                 p = string_nocheck(p, pend, "io  ", str_spec);
1055                 specp = &io_spec;
1056         } else if (res->flags & IORESOURCE_MEM) {
1057                 p = string_nocheck(p, pend, "mem ", str_spec);
1058                 specp = &mem_spec;
1059         } else if (res->flags & IORESOURCE_IRQ) {
1060                 p = string_nocheck(p, pend, "irq ", str_spec);
1061                 specp = &default_dec_spec;
1062         } else if (res->flags & IORESOURCE_DMA) {
1063                 p = string_nocheck(p, pend, "dma ", str_spec);
1064                 specp = &default_dec_spec;
1065         } else if (res->flags & IORESOURCE_BUS) {
1066                 p = string_nocheck(p, pend, "bus ", str_spec);
1067                 specp = &bus_spec;
1068         } else {
1069                 p = string_nocheck(p, pend, "??? ", str_spec);
1070                 specp = &mem_spec;
1071                 decode = 0;
1072         }
1073         if (decode && res->flags & IORESOURCE_UNSET) {
1074                 p = string_nocheck(p, pend, "size ", str_spec);
1075                 p = number(p, pend, resource_size(res), *specp);
1076         } else {
1077                 p = number(p, pend, res->start, *specp);
1078                 if (res->start != res->end) {
1079                         *p++ = '-';
1080                         p = number(p, pend, res->end, *specp);
1081                 }
1082         }
1083         if (decode) {
1084                 if (res->flags & IORESOURCE_MEM_64)
1085                         p = string_nocheck(p, pend, " 64bit", str_spec);
1086                 if (res->flags & IORESOURCE_PREFETCH)
1087                         p = string_nocheck(p, pend, " pref", str_spec);
1088                 if (res->flags & IORESOURCE_WINDOW)
1089                         p = string_nocheck(p, pend, " window", str_spec);
1090                 if (res->flags & IORESOURCE_DISABLED)
1091                         p = string_nocheck(p, pend, " disabled", str_spec);
1092         } else {
1093                 p = string_nocheck(p, pend, " flags ", str_spec);
1094                 p = number(p, pend, res->flags, default_flag_spec);
1095         }
1096         *p++ = ']';
1097         *p = '\0';
1098
1099         return string_nocheck(buf, end, sym, spec);
1100 }
1101
1102 static noinline_for_stack
1103 char *hex_string(char *buf, char *end, u8 *addr, struct printf_spec spec,
1104                  const char *fmt)
1105 {
1106         int i, len = 1;         /* if we pass '%ph[CDN]', field width remains
1107                                    negative value, fallback to the default */
1108         char separator;
1109
1110         if (spec.field_width == 0)
1111                 /* nothing to print */
1112                 return buf;
1113
1114         if (check_pointer(&buf, end, addr, spec))
1115                 return buf;
1116
1117         switch (fmt[1]) {
1118         case 'C':
1119                 separator = ':';
1120                 break;
1121         case 'D':
1122                 separator = '-';
1123                 break;
1124         case 'N':
1125                 separator = 0;
1126                 break;
1127         default:
1128                 separator = ' ';
1129                 break;
1130         }
1131
1132         if (spec.field_width > 0)
1133                 len = min_t(int, spec.field_width, 64);
1134
1135         for (i = 0; i < len; ++i) {
1136                 if (buf < end)
1137                         *buf = hex_asc_hi(addr[i]);
1138                 ++buf;
1139                 if (buf < end)
1140                         *buf = hex_asc_lo(addr[i]);
1141                 ++buf;
1142
1143                 if (separator && i != len - 1) {
1144                         if (buf < end)
1145                                 *buf = separator;
1146                         ++buf;
1147                 }
1148         }
1149
1150         return buf;
1151 }
1152
1153 static noinline_for_stack
1154 char *bitmap_string(char *buf, char *end, unsigned long *bitmap,
1155                     struct printf_spec spec, const char *fmt)
1156 {
1157         const int CHUNKSZ = 32;
1158         int nr_bits = max_t(int, spec.field_width, 0);
1159         int i, chunksz;
1160         bool first = true;
1161
1162         if (check_pointer(&buf, end, bitmap, spec))
1163                 return buf;
1164
1165         /* reused to print numbers */
1166         spec = (struct printf_spec){ .flags = SMALL | ZEROPAD, .base = 16 };
1167
1168         chunksz = nr_bits & (CHUNKSZ - 1);
1169         if (chunksz == 0)
1170                 chunksz = CHUNKSZ;
1171
1172         i = ALIGN(nr_bits, CHUNKSZ) - CHUNKSZ;
1173         for (; i >= 0; i -= CHUNKSZ) {
1174                 u32 chunkmask, val;
1175                 int word, bit;
1176
1177                 chunkmask = ((1ULL << chunksz) - 1);
1178                 word = i / BITS_PER_LONG;
1179                 bit = i % BITS_PER_LONG;
1180                 val = (bitmap[word] >> bit) & chunkmask;
1181
1182                 if (!first) {
1183                         if (buf < end)
1184                                 *buf = ',';
1185                         buf++;
1186                 }
1187                 first = false;
1188
1189                 spec.field_width = DIV_ROUND_UP(chunksz, 4);
1190                 buf = number(buf, end, val, spec);
1191
1192                 chunksz = CHUNKSZ;
1193         }
1194         return buf;
1195 }
1196
1197 static noinline_for_stack
1198 char *bitmap_list_string(char *buf, char *end, unsigned long *bitmap,
1199                          struct printf_spec spec, const char *fmt)
1200 {
1201         int nr_bits = max_t(int, spec.field_width, 0);
1202         /* current bit is 'cur', most recently seen range is [rbot, rtop] */
1203         int cur, rbot, rtop;
1204         bool first = true;
1205
1206         if (check_pointer(&buf, end, bitmap, spec))
1207                 return buf;
1208
1209         rbot = cur = find_first_bit(bitmap, nr_bits);
1210         while (cur < nr_bits) {
1211                 rtop = cur;
1212                 cur = find_next_bit(bitmap, nr_bits, cur + 1);
1213                 if (cur < nr_bits && cur <= rtop + 1)
1214                         continue;
1215
1216                 if (!first) {
1217                         if (buf < end)
1218                                 *buf = ',';
1219                         buf++;
1220                 }
1221                 first = false;
1222
1223                 buf = number(buf, end, rbot, default_dec_spec);
1224                 if (rbot < rtop) {
1225                         if (buf < end)
1226                                 *buf = '-';
1227                         buf++;
1228
1229                         buf = number(buf, end, rtop, default_dec_spec);
1230                 }
1231
1232                 rbot = cur;
1233         }
1234         return buf;
1235 }
1236
1237 static noinline_for_stack
1238 char *mac_address_string(char *buf, char *end, u8 *addr,
1239                          struct printf_spec spec, const char *fmt)
1240 {
1241         char mac_addr[sizeof("xx:xx:xx:xx:xx:xx")];
1242         char *p = mac_addr;
1243         int i;
1244         char separator;
1245         bool reversed = false;
1246
1247         if (check_pointer(&buf, end, addr, spec))
1248                 return buf;
1249
1250         switch (fmt[1]) {
1251         case 'F':
1252                 separator = '-';
1253                 break;
1254
1255         case 'R':
1256                 reversed = true;
1257                 /* fall through */
1258
1259         default:
1260                 separator = ':';
1261                 break;
1262         }
1263
1264         for (i = 0; i < 6; i++) {
1265                 if (reversed)
1266                         p = hex_byte_pack(p, addr[5 - i]);
1267                 else
1268                         p = hex_byte_pack(p, addr[i]);
1269
1270                 if (fmt[0] == 'M' && i != 5)
1271                         *p++ = separator;
1272         }
1273         *p = '\0';
1274
1275         return string_nocheck(buf, end, mac_addr, spec);
1276 }
1277
1278 static noinline_for_stack
1279 char *ip4_string(char *p, const u8 *addr, const char *fmt)
1280 {
1281         int i;
1282         bool leading_zeros = (fmt[0] == 'i');
1283         int index;
1284         int step;
1285
1286         switch (fmt[2]) {
1287         case 'h':
1288 #ifdef __BIG_ENDIAN
1289                 index = 0;
1290                 step = 1;
1291 #else
1292                 index = 3;
1293                 step = -1;
1294 #endif
1295                 break;
1296         case 'l':
1297                 index = 3;
1298                 step = -1;
1299                 break;
1300         case 'n':
1301         case 'b':
1302         default:
1303                 index = 0;
1304                 step = 1;
1305                 break;
1306         }
1307         for (i = 0; i < 4; i++) {
1308                 char temp[4] __aligned(2);      /* hold each IP quad in reverse order */
1309                 int digits = put_dec_trunc8(temp, addr[index]) - temp;
1310                 if (leading_zeros) {
1311                         if (digits < 3)
1312                                 *p++ = '0';
1313                         if (digits < 2)
1314                                 *p++ = '0';
1315                 }
1316                 /* reverse the digits in the quad */
1317                 while (digits--)
1318                         *p++ = temp[digits];
1319                 if (i < 3)
1320                         *p++ = '.';
1321                 index += step;
1322         }
1323         *p = '\0';
1324
1325         return p;
1326 }
1327
1328 static noinline_for_stack
1329 char *ip6_compressed_string(char *p, const char *addr)
1330 {
1331         int i, j, range;
1332         unsigned char zerolength[8];
1333         int longest = 1;
1334         int colonpos = -1;
1335         u16 word;
1336         u8 hi, lo;
1337         bool needcolon = false;
1338         bool useIPv4;
1339         struct in6_addr in6;
1340
1341         memcpy(&in6, addr, sizeof(struct in6_addr));
1342
1343         useIPv4 = ipv6_addr_v4mapped(&in6) || ipv6_addr_is_isatap(&in6);
1344
1345         memset(zerolength, 0, sizeof(zerolength));
1346
1347         if (useIPv4)
1348                 range = 6;
1349         else
1350                 range = 8;
1351
1352         /* find position of longest 0 run */
1353         for (i = 0; i < range; i++) {
1354                 for (j = i; j < range; j++) {
1355                         if (in6.s6_addr16[j] != 0)
1356                                 break;
1357                         zerolength[i]++;
1358                 }
1359         }
1360         for (i = 0; i < range; i++) {
1361                 if (zerolength[i] > longest) {
1362                         longest = zerolength[i];
1363                         colonpos = i;
1364                 }
1365         }
1366         if (longest == 1)               /* don't compress a single 0 */
1367                 colonpos = -1;
1368
1369         /* emit address */
1370         for (i = 0; i < range; i++) {
1371                 if (i == colonpos) {
1372                         if (needcolon || i == 0)
1373                                 *p++ = ':';
1374                         *p++ = ':';
1375                         needcolon = false;
1376                         i += longest - 1;
1377                         continue;
1378                 }
1379                 if (needcolon) {
1380                         *p++ = ':';
1381                         needcolon = false;
1382                 }
1383                 /* hex u16 without leading 0s */
1384                 word = ntohs(in6.s6_addr16[i]);
1385                 hi = word >> 8;
1386                 lo = word & 0xff;
1387                 if (hi) {
1388                         if (hi > 0x0f)
1389                                 p = hex_byte_pack(p, hi);
1390                         else
1391                                 *p++ = hex_asc_lo(hi);
1392                         p = hex_byte_pack(p, lo);
1393                 }
1394                 else if (lo > 0x0f)
1395                         p = hex_byte_pack(p, lo);
1396                 else
1397                         *p++ = hex_asc_lo(lo);
1398                 needcolon = true;
1399         }
1400
1401         if (useIPv4) {
1402                 if (needcolon)
1403                         *p++ = ':';
1404                 p = ip4_string(p, &in6.s6_addr[12], "I4");
1405         }
1406         *p = '\0';
1407
1408         return p;
1409 }
1410
1411 static noinline_for_stack
1412 char *ip6_string(char *p, const char *addr, const char *fmt)
1413 {
1414         int i;
1415
1416         for (i = 0; i < 8; i++) {
1417                 p = hex_byte_pack(p, *addr++);
1418                 p = hex_byte_pack(p, *addr++);
1419                 if (fmt[0] == 'I' && i != 7)
1420                         *p++ = ':';
1421         }
1422         *p = '\0';
1423
1424         return p;
1425 }
1426
1427 static noinline_for_stack
1428 char *ip6_addr_string(char *buf, char *end, const u8 *addr,
1429                       struct printf_spec spec, const char *fmt)
1430 {
1431         char ip6_addr[sizeof("xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255")];
1432
1433         if (fmt[0] == 'I' && fmt[2] == 'c')
1434                 ip6_compressed_string(ip6_addr, addr);
1435         else
1436                 ip6_string(ip6_addr, addr, fmt);
1437
1438         return string_nocheck(buf, end, ip6_addr, spec);
1439 }
1440
1441 static noinline_for_stack
1442 char *ip4_addr_string(char *buf, char *end, const u8 *addr,
1443                       struct printf_spec spec, const char *fmt)
1444 {
1445         char ip4_addr[sizeof("255.255.255.255")];
1446
1447         ip4_string(ip4_addr, addr, fmt);
1448
1449         return string_nocheck(buf, end, ip4_addr, spec);
1450 }
1451
1452 static noinline_for_stack
1453 char *ip6_addr_string_sa(char *buf, char *end, const struct sockaddr_in6 *sa,
1454                          struct printf_spec spec, const char *fmt)
1455 {
1456         bool have_p = false, have_s = false, have_f = false, have_c = false;
1457         char ip6_addr[sizeof("[xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255]") +
1458                       sizeof(":12345") + sizeof("/123456789") +
1459                       sizeof("%1234567890")];
1460         char *p = ip6_addr, *pend = ip6_addr + sizeof(ip6_addr);
1461         const u8 *addr = (const u8 *) &sa->sin6_addr;
1462         char fmt6[2] = { fmt[0], '6' };
1463         u8 off = 0;
1464
1465         fmt++;
1466         while (isalpha(*++fmt)) {
1467                 switch (*fmt) {
1468                 case 'p':
1469                         have_p = true;
1470                         break;
1471                 case 'f':
1472                         have_f = true;
1473                         break;
1474                 case 's':
1475                         have_s = true;
1476                         break;
1477                 case 'c':
1478                         have_c = true;
1479                         break;
1480                 }
1481         }
1482
1483         if (have_p || have_s || have_f) {
1484                 *p = '[';
1485                 off = 1;
1486         }
1487
1488         if (fmt6[0] == 'I' && have_c)
1489                 p = ip6_compressed_string(ip6_addr + off, addr);
1490         else
1491                 p = ip6_string(ip6_addr + off, addr, fmt6);
1492
1493         if (have_p || have_s || have_f)
1494                 *p++ = ']';
1495
1496         if (have_p) {
1497                 *p++ = ':';
1498                 p = number(p, pend, ntohs(sa->sin6_port), spec);
1499         }
1500         if (have_f) {
1501                 *p++ = '/';
1502                 p = number(p, pend, ntohl(sa->sin6_flowinfo &
1503                                           IPV6_FLOWINFO_MASK), spec);
1504         }
1505         if (have_s) {
1506                 *p++ = '%';
1507                 p = number(p, pend, sa->sin6_scope_id, spec);
1508         }
1509         *p = '\0';
1510
1511         return string_nocheck(buf, end, ip6_addr, spec);
1512 }
1513
1514 static noinline_for_stack
1515 char *ip4_addr_string_sa(char *buf, char *end, const struct sockaddr_in *sa,
1516                          struct printf_spec spec, const char *fmt)
1517 {
1518         bool have_p = false;
1519         char *p, ip4_addr[sizeof("255.255.255.255") + sizeof(":12345")];
1520         char *pend = ip4_addr + sizeof(ip4_addr);
1521         const u8 *addr = (const u8 *) &sa->sin_addr.s_addr;
1522         char fmt4[3] = { fmt[0], '4', 0 };
1523
1524         fmt++;
1525         while (isalpha(*++fmt)) {
1526                 switch (*fmt) {
1527                 case 'p':
1528                         have_p = true;
1529                         break;
1530                 case 'h':
1531                 case 'l':
1532                 case 'n':
1533                 case 'b':
1534                         fmt4[2] = *fmt;
1535                         break;
1536                 }
1537         }
1538
1539         p = ip4_string(ip4_addr, addr, fmt4);
1540         if (have_p) {
1541                 *p++ = ':';
1542                 p = number(p, pend, ntohs(sa->sin_port), spec);
1543         }
1544         *p = '\0';
1545
1546         return string_nocheck(buf, end, ip4_addr, spec);
1547 }
1548
1549 static noinline_for_stack
1550 char *ip_addr_string(char *buf, char *end, const void *ptr,
1551                      struct printf_spec spec, const char *fmt)
1552 {
1553         char *err_fmt_msg;
1554
1555         if (check_pointer(&buf, end, ptr, spec))
1556                 return buf;
1557
1558         switch (fmt[1]) {
1559         case '6':
1560                 return ip6_addr_string(buf, end, ptr, spec, fmt);
1561         case '4':
1562                 return ip4_addr_string(buf, end, ptr, spec, fmt);
1563         case 'S': {
1564                 const union {
1565                         struct sockaddr         raw;
1566                         struct sockaddr_in      v4;
1567                         struct sockaddr_in6     v6;
1568                 } *sa = ptr;
1569
1570                 switch (sa->raw.sa_family) {
1571                 case AF_INET:
1572                         return ip4_addr_string_sa(buf, end, &sa->v4, spec, fmt);
1573                 case AF_INET6:
1574                         return ip6_addr_string_sa(buf, end, &sa->v6, spec, fmt);
1575                 default:
1576                         return error_string(buf, end, "(einval)", spec);
1577                 }}
1578         }
1579
1580         err_fmt_msg = fmt[0] == 'i' ? "(%pi?)" : "(%pI?)";
1581         return error_string(buf, end, err_fmt_msg, spec);
1582 }
1583
1584 static noinline_for_stack
1585 char *escaped_string(char *buf, char *end, u8 *addr, struct printf_spec spec,
1586                      const char *fmt)
1587 {
1588         bool found = true;
1589         int count = 1;
1590         unsigned int flags = 0;
1591         int len;
1592
1593         if (spec.field_width == 0)
1594                 return buf;                             /* nothing to print */
1595
1596         if (check_pointer(&buf, end, addr, spec))
1597                 return buf;
1598
1599         do {
1600                 switch (fmt[count++]) {
1601                 case 'a':
1602                         flags |= ESCAPE_ANY;
1603                         break;
1604                 case 'c':
1605                         flags |= ESCAPE_SPECIAL;
1606                         break;
1607                 case 'h':
1608                         flags |= ESCAPE_HEX;
1609                         break;
1610                 case 'n':
1611                         flags |= ESCAPE_NULL;
1612                         break;
1613                 case 'o':
1614                         flags |= ESCAPE_OCTAL;
1615                         break;
1616                 case 'p':
1617                         flags |= ESCAPE_NP;
1618                         break;
1619                 case 's':
1620                         flags |= ESCAPE_SPACE;
1621                         break;
1622                 default:
1623                         found = false;
1624                         break;
1625                 }
1626         } while (found);
1627
1628         if (!flags)
1629                 flags = ESCAPE_ANY_NP;
1630
1631         len = spec.field_width < 0 ? 1 : spec.field_width;
1632
1633         /*
1634          * string_escape_mem() writes as many characters as it can to
1635          * the given buffer, and returns the total size of the output
1636          * had the buffer been big enough.
1637          */
1638         buf += string_escape_mem(addr, len, buf, buf < end ? end - buf : 0, flags, NULL);
1639
1640         return buf;
1641 }
1642
1643 static char *va_format(char *buf, char *end, struct va_format *va_fmt,
1644                        struct printf_spec spec, const char *fmt)
1645 {
1646         va_list va;
1647
1648         if (check_pointer(&buf, end, va_fmt, spec))
1649                 return buf;
1650
1651         va_copy(va, *va_fmt->va);
1652         buf += vsnprintf(buf, end > buf ? end - buf : 0, va_fmt->fmt, va);
1653         va_end(va);
1654
1655         return buf;
1656 }
1657
1658 static noinline_for_stack
1659 char *uuid_string(char *buf, char *end, const u8 *addr,
1660                   struct printf_spec spec, const char *fmt)
1661 {
1662         char uuid[UUID_STRING_LEN + 1];
1663         char *p = uuid;
1664         int i;
1665         const u8 *index = uuid_index;
1666         bool uc = false;
1667
1668         if (check_pointer(&buf, end, addr, spec))
1669                 return buf;
1670
1671         switch (*(++fmt)) {
1672         case 'L':
1673                 uc = true;              /* fall-through */
1674         case 'l':
1675                 index = guid_index;
1676                 break;
1677         case 'B':
1678                 uc = true;
1679                 break;
1680         }
1681
1682         for (i = 0; i < 16; i++) {
1683                 if (uc)
1684                         p = hex_byte_pack_upper(p, addr[index[i]]);
1685                 else
1686                         p = hex_byte_pack(p, addr[index[i]]);
1687                 switch (i) {
1688                 case 3:
1689                 case 5:
1690                 case 7:
1691                 case 9:
1692                         *p++ = '-';
1693                         break;
1694                 }
1695         }
1696
1697         *p = 0;
1698
1699         return string_nocheck(buf, end, uuid, spec);
1700 }
1701
1702 static noinline_for_stack
1703 char *netdev_bits(char *buf, char *end, const void *addr,
1704                   struct printf_spec spec,  const char *fmt)
1705 {
1706         unsigned long long num;
1707         int size;
1708
1709         if (check_pointer(&buf, end, addr, spec))
1710                 return buf;
1711
1712         switch (fmt[1]) {
1713         case 'F':
1714                 num = *(const netdev_features_t *)addr;
1715                 size = sizeof(netdev_features_t);
1716                 break;
1717         default:
1718                 return error_string(buf, end, "(%pN?)", spec);
1719         }
1720
1721         return special_hex_number(buf, end, num, size);
1722 }
1723
1724 static noinline_for_stack
1725 char *address_val(char *buf, char *end, const void *addr,
1726                   struct printf_spec spec, const char *fmt)
1727 {
1728         unsigned long long num;
1729         int size;
1730
1731         if (check_pointer(&buf, end, addr, spec))
1732                 return buf;
1733
1734         switch (fmt[1]) {
1735         case 'd':
1736                 num = *(const dma_addr_t *)addr;
1737                 size = sizeof(dma_addr_t);
1738                 break;
1739         case 'p':
1740         default:
1741                 num = *(const phys_addr_t *)addr;
1742                 size = sizeof(phys_addr_t);
1743                 break;
1744         }
1745
1746         return special_hex_number(buf, end, num, size);
1747 }
1748
1749 static noinline_for_stack
1750 char *date_str(char *buf, char *end, const struct rtc_time *tm, bool r)
1751 {
1752         int year = tm->tm_year + (r ? 0 : 1900);
1753         int mon = tm->tm_mon + (r ? 0 : 1);
1754
1755         buf = number(buf, end, year, default_dec04_spec);
1756         if (buf < end)
1757                 *buf = '-';
1758         buf++;
1759
1760         buf = number(buf, end, mon, default_dec02_spec);
1761         if (buf < end)
1762                 *buf = '-';
1763         buf++;
1764
1765         return number(buf, end, tm->tm_mday, default_dec02_spec);
1766 }
1767
1768 static noinline_for_stack
1769 char *time_str(char *buf, char *end, const struct rtc_time *tm, bool r)
1770 {
1771         buf = number(buf, end, tm->tm_hour, default_dec02_spec);
1772         if (buf < end)
1773                 *buf = ':';
1774         buf++;
1775
1776         buf = number(buf, end, tm->tm_min, default_dec02_spec);
1777         if (buf < end)
1778                 *buf = ':';
1779         buf++;
1780
1781         return number(buf, end, tm->tm_sec, default_dec02_spec);
1782 }
1783
1784 static noinline_for_stack
1785 char *rtc_str(char *buf, char *end, const struct rtc_time *tm,
1786               struct printf_spec spec, const char *fmt)
1787 {
1788         bool have_t = true, have_d = true;
1789         bool raw = false;
1790         int count = 2;
1791
1792         if (check_pointer(&buf, end, tm, spec))
1793                 return buf;
1794
1795         switch (fmt[count]) {
1796         case 'd':
1797                 have_t = false;
1798                 count++;
1799                 break;
1800         case 't':
1801                 have_d = false;
1802                 count++;
1803                 break;
1804         }
1805
1806         raw = fmt[count] == 'r';
1807
1808         if (have_d)
1809                 buf = date_str(buf, end, tm, raw);
1810         if (have_d && have_t) {
1811                 /* Respect ISO 8601 */
1812                 if (buf < end)
1813                         *buf = 'T';
1814                 buf++;
1815         }
1816         if (have_t)
1817                 buf = time_str(buf, end, tm, raw);
1818
1819         return buf;
1820 }
1821
1822 static noinline_for_stack
1823 char *time_and_date(char *buf, char *end, void *ptr, struct printf_spec spec,
1824                     const char *fmt)
1825 {
1826         switch (fmt[1]) {
1827         case 'R':
1828                 return rtc_str(buf, end, (const struct rtc_time *)ptr, spec, fmt);
1829         default:
1830                 return error_string(buf, end, "(%ptR?)", spec);
1831         }
1832 }
1833
1834 static noinline_for_stack
1835 char *clock(char *buf, char *end, struct clk *clk, struct printf_spec spec,
1836             const char *fmt)
1837 {
1838         if (!IS_ENABLED(CONFIG_HAVE_CLK))
1839                 return error_string(buf, end, "(%pC?)", spec);
1840
1841         if (check_pointer(&buf, end, clk, spec))
1842                 return buf;
1843
1844         switch (fmt[1]) {
1845         case 'n':
1846         default:
1847 #ifdef CONFIG_COMMON_CLK
1848                 return string(buf, end, __clk_get_name(clk), spec);
1849 #else
1850                 return ptr_to_id(buf, end, clk, spec);
1851 #endif
1852         }
1853 }
1854
1855 static
1856 char *format_flags(char *buf, char *end, unsigned long flags,
1857                                         const struct trace_print_flags *names)
1858 {
1859         unsigned long mask;
1860
1861         for ( ; flags && names->name; names++) {
1862                 mask = names->mask;
1863                 if ((flags & mask) != mask)
1864                         continue;
1865
1866                 buf = string(buf, end, names->name, default_str_spec);
1867
1868                 flags &= ~mask;
1869                 if (flags) {
1870                         if (buf < end)
1871                                 *buf = '|';
1872                         buf++;
1873                 }
1874         }
1875
1876         if (flags)
1877                 buf = number(buf, end, flags, default_flag_spec);
1878
1879         return buf;
1880 }
1881
1882 static noinline_for_stack
1883 char *flags_string(char *buf, char *end, void *flags_ptr,
1884                    struct printf_spec spec, const char *fmt)
1885 {
1886         unsigned long flags;
1887         const struct trace_print_flags *names;
1888
1889         if (check_pointer(&buf, end, flags_ptr, spec))
1890                 return buf;
1891
1892         switch (fmt[1]) {
1893         case 'p':
1894                 flags = *(unsigned long *)flags_ptr;
1895                 /* Remove zone id */
1896                 flags &= (1UL << NR_PAGEFLAGS) - 1;
1897                 names = pageflag_names;
1898                 break;
1899         case 'v':
1900                 flags = *(unsigned long *)flags_ptr;
1901                 names = vmaflag_names;
1902                 break;
1903         case 'g':
1904                 flags = *(gfp_t *)flags_ptr;
1905                 names = gfpflag_names;
1906                 break;
1907         default:
1908                 return error_string(buf, end, "(%pG?)", spec);
1909         }
1910
1911         return format_flags(buf, end, flags, names);
1912 }
1913
1914 static noinline_for_stack
1915 char *fwnode_full_name_string(struct fwnode_handle *fwnode, char *buf,
1916                               char *end)
1917 {
1918         int depth;
1919
1920         /* Loop starting from the root node to the current node. */
1921         for (depth = fwnode_count_parents(fwnode); depth >= 0; depth--) {
1922                 struct fwnode_handle *__fwnode =
1923                         fwnode_get_nth_parent(fwnode, depth);
1924
1925                 buf = string(buf, end, fwnode_get_name_prefix(__fwnode),
1926                              default_str_spec);
1927                 buf = string(buf, end, fwnode_get_name(__fwnode),
1928                              default_str_spec);
1929
1930                 fwnode_handle_put(__fwnode);
1931         }
1932
1933         return buf;
1934 }
1935
1936 static noinline_for_stack
1937 char *device_node_string(char *buf, char *end, struct device_node *dn,
1938                          struct printf_spec spec, const char *fmt)
1939 {
1940         char tbuf[sizeof("xxxx") + 1];
1941         const char *p;
1942         int ret;
1943         char *buf_start = buf;
1944         struct property *prop;
1945         bool has_mult, pass;
1946         static const struct printf_spec num_spec = {
1947                 .flags = SMALL,
1948                 .field_width = -1,
1949                 .precision = -1,
1950                 .base = 10,
1951         };
1952
1953         struct printf_spec str_spec = spec;
1954         str_spec.field_width = -1;
1955
1956         if (fmt[0] != 'F')
1957                 return error_string(buf, end, "(%pO?)", spec);
1958
1959         if (!IS_ENABLED(CONFIG_OF))
1960                 return error_string(buf, end, "(%pOF?)", spec);
1961
1962         if (check_pointer(&buf, end, dn, spec))
1963                 return buf;
1964
1965         /* simple case without anything any more format specifiers */
1966         fmt++;
1967         if (fmt[0] == '\0' || strcspn(fmt,"fnpPFcC") > 0)
1968                 fmt = "f";
1969
1970         for (pass = false; strspn(fmt,"fnpPFcC"); fmt++, pass = true) {
1971                 int precision;
1972                 if (pass) {
1973                         if (buf < end)
1974                                 *buf = ':';
1975                         buf++;
1976                 }
1977
1978                 switch (*fmt) {
1979                 case 'f':       /* full_name */
1980                         buf = fwnode_full_name_string(of_fwnode_handle(dn), buf,
1981                                                       end);
1982                         break;
1983                 case 'n':       /* name */
1984                         p = fwnode_get_name(of_fwnode_handle(dn));
1985                         precision = str_spec.precision;
1986                         str_spec.precision = strchrnul(p, '@') - p;
1987                         buf = string(buf, end, p, str_spec);
1988                         str_spec.precision = precision;
1989                         break;
1990                 case 'p':       /* phandle */
1991                         buf = number(buf, end, (unsigned int)dn->phandle, num_spec);
1992                         break;
1993                 case 'P':       /* path-spec */
1994                         p = fwnode_get_name(of_fwnode_handle(dn));
1995                         if (!p[1])
1996                                 p = "/";
1997                         buf = string(buf, end, p, str_spec);
1998                         break;
1999                 case 'F':       /* flags */
2000                         tbuf[0] = of_node_check_flag(dn, OF_DYNAMIC) ? 'D' : '-';
2001                         tbuf[1] = of_node_check_flag(dn, OF_DETACHED) ? 'd' : '-';
2002                         tbuf[2] = of_node_check_flag(dn, OF_POPULATED) ? 'P' : '-';
2003                         tbuf[3] = of_node_check_flag(dn, OF_POPULATED_BUS) ? 'B' : '-';
2004                         tbuf[4] = 0;
2005                         buf = string_nocheck(buf, end, tbuf, str_spec);
2006                         break;
2007                 case 'c':       /* major compatible string */
2008                         ret = of_property_read_string(dn, "compatible", &p);
2009                         if (!ret)
2010                                 buf = string(buf, end, p, str_spec);
2011                         break;
2012                 case 'C':       /* full compatible string */
2013                         has_mult = false;
2014                         of_property_for_each_string(dn, "compatible", prop, p) {
2015                                 if (has_mult)
2016                                         buf = string_nocheck(buf, end, ",", str_spec);
2017                                 buf = string_nocheck(buf, end, "\"", str_spec);
2018                                 buf = string(buf, end, p, str_spec);
2019                                 buf = string_nocheck(buf, end, "\"", str_spec);
2020
2021                                 has_mult = true;
2022                         }
2023                         break;
2024                 default:
2025                         break;
2026                 }
2027         }
2028
2029         return widen_string(buf, buf - buf_start, end, spec);
2030 }
2031
2032 static noinline_for_stack
2033 char *fwnode_string(char *buf, char *end, struct fwnode_handle *fwnode,
2034                     struct printf_spec spec, const char *fmt)
2035 {
2036         struct printf_spec str_spec = spec;
2037         char *buf_start = buf;
2038
2039         str_spec.field_width = -1;
2040
2041         if (*fmt != 'w')
2042                 return error_string(buf, end, "(%pf?)", spec);
2043
2044         if (check_pointer(&buf, end, fwnode, spec))
2045                 return buf;
2046
2047         fmt++;
2048
2049         switch (*fmt) {
2050         case 'P':       /* name */
2051                 buf = string(buf, end, fwnode_get_name(fwnode), str_spec);
2052                 break;
2053         case 'f':       /* full_name */
2054         default:
2055                 buf = fwnode_full_name_string(fwnode, buf, end);
2056                 break;
2057         }
2058
2059         return widen_string(buf, buf - buf_start, end, spec);
2060 }
2061
2062 /*
2063  * Show a '%p' thing.  A kernel extension is that the '%p' is followed
2064  * by an extra set of alphanumeric characters that are extended format
2065  * specifiers.
2066  *
2067  * Please update scripts/checkpatch.pl when adding/removing conversion
2068  * characters.  (Search for "check for vsprintf extension").
2069  *
2070  * Right now we handle:
2071  *
2072  * - 'S' For symbolic direct pointers (or function descriptors) with offset
2073  * - 's' For symbolic direct pointers (or function descriptors) without offset
2074  * - '[Ss]R' as above with __builtin_extract_return_addr() translation
2075  * - '[Ff]' %pf and %pF were obsoleted and later removed in favor of
2076  *          %ps and %pS. Be careful when re-using these specifiers.
2077  * - 'B' For backtraced symbolic direct pointers with offset
2078  * - 'R' For decoded struct resource, e.g., [mem 0x0-0x1f 64bit pref]
2079  * - 'r' For raw struct resource, e.g., [mem 0x0-0x1f flags 0x201]
2080  * - 'b[l]' For a bitmap, the number of bits is determined by the field
2081  *       width which must be explicitly specified either as part of the
2082  *       format string '%32b[l]' or through '%*b[l]', [l] selects
2083  *       range-list format instead of hex format
2084  * - 'M' For a 6-byte MAC address, it prints the address in the
2085  *       usual colon-separated hex notation
2086  * - 'm' For a 6-byte MAC address, it prints the hex address without colons
2087  * - 'MF' For a 6-byte MAC FDDI address, it prints the address
2088  *       with a dash-separated hex notation
2089  * - '[mM]R' For a 6-byte MAC address, Reverse order (Bluetooth)
2090  * - 'I' [46] for IPv4/IPv6 addresses printed in the usual way
2091  *       IPv4 uses dot-separated decimal without leading 0's (1.2.3.4)
2092  *       IPv6 uses colon separated network-order 16 bit hex with leading 0's
2093  *       [S][pfs]
2094  *       Generic IPv4/IPv6 address (struct sockaddr *) that falls back to
2095  *       [4] or [6] and is able to print port [p], flowinfo [f], scope [s]
2096  * - 'i' [46] for 'raw' IPv4/IPv6 addresses
2097  *       IPv6 omits the colons (01020304...0f)
2098  *       IPv4 uses dot-separated decimal with leading 0's (010.123.045.006)
2099  *       [S][pfs]
2100  *       Generic IPv4/IPv6 address (struct sockaddr *) that falls back to
2101  *       [4] or [6] and is able to print port [p], flowinfo [f], scope [s]
2102  * - '[Ii][4S][hnbl]' IPv4 addresses in host, network, big or little endian order
2103  * - 'I[6S]c' for IPv6 addresses printed as specified by
2104  *       http://tools.ietf.org/html/rfc5952
2105  * - 'E[achnops]' For an escaped buffer, where rules are defined by combination
2106  *                of the following flags (see string_escape_mem() for the
2107  *                details):
2108  *                  a - ESCAPE_ANY
2109  *                  c - ESCAPE_SPECIAL
2110  *                  h - ESCAPE_HEX
2111  *                  n - ESCAPE_NULL
2112  *                  o - ESCAPE_OCTAL
2113  *                  p - ESCAPE_NP
2114  *                  s - ESCAPE_SPACE
2115  *                By default ESCAPE_ANY_NP is used.
2116  * - 'U' For a 16 byte UUID/GUID, it prints the UUID/GUID in the form
2117  *       "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx"
2118  *       Options for %pU are:
2119  *         b big endian lower case hex (default)
2120  *         B big endian UPPER case hex
2121  *         l little endian lower case hex
2122  *         L little endian UPPER case hex
2123  *           big endian output byte order is:
2124  *             [0][1][2][3]-[4][5]-[6][7]-[8][9]-[10][11][12][13][14][15]
2125  *           little endian output byte order is:
2126  *             [3][2][1][0]-[5][4]-[7][6]-[8][9]-[10][11][12][13][14][15]
2127  * - 'V' For a struct va_format which contains a format string * and va_list *,
2128  *       call vsnprintf(->format, *->va_list).
2129  *       Implements a "recursive vsnprintf".
2130  *       Do not use this feature without some mechanism to verify the
2131  *       correctness of the format string and va_list arguments.
2132  * - 'K' For a kernel pointer that should be hidden from unprivileged users
2133  * - 'NF' For a netdev_features_t
2134  * - 'h[CDN]' For a variable-length buffer, it prints it as a hex string with
2135  *            a certain separator (' ' by default):
2136  *              C colon
2137  *              D dash
2138  *              N no separator
2139  *            The maximum supported length is 64 bytes of the input. Consider
2140  *            to use print_hex_dump() for the larger input.
2141  * - 'a[pd]' For address types [p] phys_addr_t, [d] dma_addr_t and derivatives
2142  *           (default assumed to be phys_addr_t, passed by reference)
2143  * - 'd[234]' For a dentry name (optionally 2-4 last components)
2144  * - 'D[234]' Same as 'd' but for a struct file
2145  * - 'g' For block_device name (gendisk + partition number)
2146  * - 't[R][dt][r]' For time and date as represented:
2147  *      R    struct rtc_time
2148  * - 'C' For a clock, it prints the name (Common Clock Framework) or address
2149  *       (legacy clock framework) of the clock
2150  * - 'Cn' For a clock, it prints the name (Common Clock Framework) or address
2151  *        (legacy clock framework) of the clock
2152  * - 'G' For flags to be printed as a collection of symbolic strings that would
2153  *       construct the specific value. Supported flags given by option:
2154  *       p page flags (see struct page) given as pointer to unsigned long
2155  *       g gfp flags (GFP_* and __GFP_*) given as pointer to gfp_t
2156  *       v vma flags (VM_*) given as pointer to unsigned long
2157  * - 'OF[fnpPcCF]'  For a device tree object
2158  *                  Without any optional arguments prints the full_name
2159  *                  f device node full_name
2160  *                  n device node name
2161  *                  p device node phandle
2162  *                  P device node path spec (name + @unit)
2163  *                  F device node flags
2164  *                  c major compatible string
2165  *                  C full compatible string
2166  * - 'fw[fP]'   For a firmware node (struct fwnode_handle) pointer
2167  *              Without an option prints the full name of the node
2168  *              f full name
2169  *              P node name, including a possible unit address
2170  * - 'x' For printing the address. Equivalent to "%lx".
2171  *
2172  * ** When making changes please also update:
2173  *      Documentation/core-api/printk-formats.rst
2174  *
2175  * Note: The default behaviour (unadorned %p) is to hash the address,
2176  * rendering it useful as a unique identifier.
2177  */
2178 static noinline_for_stack
2179 char *pointer(const char *fmt, char *buf, char *end, void *ptr,
2180               struct printf_spec spec)
2181 {
2182         switch (*fmt) {
2183         case 'S':
2184         case 's':
2185                 ptr = dereference_symbol_descriptor(ptr);
2186                 /* Fallthrough */
2187         case 'B':
2188                 return symbol_string(buf, end, ptr, spec, fmt);
2189         case 'R':
2190         case 'r':
2191                 return resource_string(buf, end, ptr, spec, fmt);
2192         case 'h':
2193                 return hex_string(buf, end, ptr, spec, fmt);
2194         case 'b':
2195                 switch (fmt[1]) {
2196                 case 'l':
2197                         return bitmap_list_string(buf, end, ptr, spec, fmt);
2198                 default:
2199                         return bitmap_string(buf, end, ptr, spec, fmt);
2200                 }
2201         case 'M':                       /* Colon separated: 00:01:02:03:04:05 */
2202         case 'm':                       /* Contiguous: 000102030405 */
2203                                         /* [mM]F (FDDI) */
2204                                         /* [mM]R (Reverse order; Bluetooth) */
2205                 return mac_address_string(buf, end, ptr, spec, fmt);
2206         case 'I':                       /* Formatted IP supported
2207                                          * 4:   1.2.3.4
2208                                          * 6:   0001:0203:...:0708
2209                                          * 6c:  1::708 or 1::1.2.3.4
2210                                          */
2211         case 'i':                       /* Contiguous:
2212                                          * 4:   001.002.003.004
2213                                          * 6:   000102...0f
2214                                          */
2215                 return ip_addr_string(buf, end, ptr, spec, fmt);
2216         case 'E':
2217                 return escaped_string(buf, end, ptr, spec, fmt);
2218         case 'U':
2219                 return uuid_string(buf, end, ptr, spec, fmt);
2220         case 'V':
2221                 return va_format(buf, end, ptr, spec, fmt);
2222         case 'K':
2223                 return restricted_pointer(buf, end, ptr, spec);
2224         case 'N':
2225                 return netdev_bits(buf, end, ptr, spec, fmt);
2226         case 'a':
2227                 return address_val(buf, end, ptr, spec, fmt);
2228         case 'd':
2229                 return dentry_name(buf, end, ptr, spec, fmt);
2230         case 't':
2231                 return time_and_date(buf, end, ptr, spec, fmt);
2232         case 'C':
2233                 return clock(buf, end, ptr, spec, fmt);
2234         case 'D':
2235                 return file_dentry_name(buf, end, ptr, spec, fmt);
2236 #ifdef CONFIG_BLOCK
2237         case 'g':
2238                 return bdev_name(buf, end, ptr, spec, fmt);
2239 #endif
2240
2241         case 'G':
2242                 return flags_string(buf, end, ptr, spec, fmt);
2243         case 'O':
2244                 return device_node_string(buf, end, ptr, spec, fmt + 1);
2245         case 'f':
2246                 return fwnode_string(buf, end, ptr, spec, fmt + 1);
2247         case 'x':
2248                 return pointer_string(buf, end, ptr, spec);
2249         case 'e':
2250                 /* %pe with a non-ERR_PTR gets treated as plain %p */
2251                 if (!IS_ERR(ptr))
2252                         break;
2253                 return err_ptr(buf, end, ptr, spec);
2254         }
2255
2256         /* default is to _not_ leak addresses, hash before printing */
2257         return ptr_to_id(buf, end, ptr, spec);
2258 }
2259
2260 /*
2261  * Helper function to decode printf style format.
2262  * Each call decode a token from the format and return the
2263  * number of characters read (or likely the delta where it wants
2264  * to go on the next call).
2265  * The decoded token is returned through the parameters
2266  *
2267  * 'h', 'l', or 'L' for integer fields
2268  * 'z' support added 23/7/1999 S.H.
2269  * 'z' changed to 'Z' --davidm 1/25/99
2270  * 'Z' changed to 'z' --adobriyan 2017-01-25
2271  * 't' added for ptrdiff_t
2272  *
2273  * @fmt: the format string
2274  * @type of the token returned
2275  * @flags: various flags such as +, -, # tokens..
2276  * @field_width: overwritten width
2277  * @base: base of the number (octal, hex, ...)
2278  * @precision: precision of a number
2279  * @qualifier: qualifier of a number (long, size_t, ...)
2280  */
2281 static noinline_for_stack
2282 int format_decode(const char *fmt, struct printf_spec *spec)
2283 {
2284         const char *start = fmt;
2285         char qualifier;
2286
2287         /* we finished early by reading the field width */
2288         if (spec->type == FORMAT_TYPE_WIDTH) {
2289                 if (spec->field_width < 0) {
2290                         spec->field_width = -spec->field_width;
2291                         spec->flags |= LEFT;
2292                 }
2293                 spec->type = FORMAT_TYPE_NONE;
2294                 goto precision;
2295         }
2296
2297         /* we finished early by reading the precision */
2298         if (spec->type == FORMAT_TYPE_PRECISION) {
2299                 if (spec->precision < 0)
2300                         spec->precision = 0;
2301
2302                 spec->type = FORMAT_TYPE_NONE;
2303                 goto qualifier;
2304         }
2305
2306         /* By default */
2307         spec->type = FORMAT_TYPE_NONE;
2308
2309         for (; *fmt ; ++fmt) {
2310                 if (*fmt == '%')
2311                         break;
2312         }
2313
2314         /* Return the current non-format string */
2315         if (fmt != start || !*fmt)
2316                 return fmt - start;
2317
2318         /* Process flags */
2319         spec->flags = 0;
2320
2321         while (1) { /* this also skips first '%' */
2322                 bool found = true;
2323
2324                 ++fmt;
2325
2326                 switch (*fmt) {
2327                 case '-': spec->flags |= LEFT;    break;
2328                 case '+': spec->flags |= PLUS;    break;
2329                 case ' ': spec->flags |= SPACE;   break;
2330                 case '#': spec->flags |= SPECIAL; break;
2331                 case '0': spec->flags |= ZEROPAD; break;
2332                 default:  found = false;
2333                 }
2334
2335                 if (!found)
2336                         break;
2337         }
2338
2339         /* get field width */
2340         spec->field_width = -1;
2341
2342         if (isdigit(*fmt))
2343                 spec->field_width = skip_atoi(&fmt);
2344         else if (*fmt == '*') {
2345                 /* it's the next argument */
2346                 spec->type = FORMAT_TYPE_WIDTH;
2347                 return ++fmt - start;
2348         }
2349
2350 precision:
2351         /* get the precision */
2352         spec->precision = -1;
2353         if (*fmt == '.') {
2354                 ++fmt;
2355                 if (isdigit(*fmt)) {
2356                         spec->precision = skip_atoi(&fmt);
2357                         if (spec->precision < 0)
2358                                 spec->precision = 0;
2359                 } else if (*fmt == '*') {
2360                         /* it's the next argument */
2361                         spec->type = FORMAT_TYPE_PRECISION;
2362                         return ++fmt - start;
2363                 }
2364         }
2365
2366 qualifier:
2367         /* get the conversion qualifier */
2368         qualifier = 0;
2369         if (*fmt == 'h' || _tolower(*fmt) == 'l' ||
2370             *fmt == 'z' || *fmt == 't') {
2371                 qualifier = *fmt++;
2372                 if (unlikely(qualifier == *fmt)) {
2373                         if (qualifier == 'l') {
2374                                 qualifier = 'L';
2375                                 ++fmt;
2376                         } else if (qualifier == 'h') {
2377                                 qualifier = 'H';
2378                                 ++fmt;
2379                         }
2380                 }
2381         }
2382
2383         /* default base */
2384         spec->base = 10;
2385         switch (*fmt) {
2386         case 'c':
2387                 spec->type = FORMAT_TYPE_CHAR;
2388                 return ++fmt - start;
2389
2390         case 's':
2391                 spec->type = FORMAT_TYPE_STR;
2392                 return ++fmt - start;
2393
2394         case 'p':
2395                 spec->type = FORMAT_TYPE_PTR;
2396                 return ++fmt - start;
2397
2398         case '%':
2399                 spec->type = FORMAT_TYPE_PERCENT_CHAR;
2400                 return ++fmt - start;
2401
2402         /* integer number formats - set up the flags and "break" */
2403         case 'o':
2404                 spec->base = 8;
2405                 break;
2406
2407         case 'x':
2408                 spec->flags |= SMALL;
2409                 /* fall through */
2410
2411         case 'X':
2412                 spec->base = 16;
2413                 break;
2414
2415         case 'd':
2416         case 'i':
2417                 spec->flags |= SIGN;
2418         case 'u':
2419                 break;
2420
2421         case 'n':
2422                 /*
2423                  * Since %n poses a greater security risk than
2424                  * utility, treat it as any other invalid or
2425                  * unsupported format specifier.
2426                  */
2427                 /* Fall-through */
2428
2429         default:
2430                 WARN_ONCE(1, "Please remove unsupported %%%c in format string\n", *fmt);
2431                 spec->type = FORMAT_TYPE_INVALID;
2432                 return fmt - start;
2433         }
2434
2435         if (qualifier == 'L')
2436                 spec->type = FORMAT_TYPE_LONG_LONG;
2437         else if (qualifier == 'l') {
2438                 BUILD_BUG_ON(FORMAT_TYPE_ULONG + SIGN != FORMAT_TYPE_LONG);
2439                 spec->type = FORMAT_TYPE_ULONG + (spec->flags & SIGN);
2440         } else if (qualifier == 'z') {
2441                 spec->type = FORMAT_TYPE_SIZE_T;
2442         } else if (qualifier == 't') {
2443                 spec->type = FORMAT_TYPE_PTRDIFF;
2444         } else if (qualifier == 'H') {
2445                 BUILD_BUG_ON(FORMAT_TYPE_UBYTE + SIGN != FORMAT_TYPE_BYTE);
2446                 spec->type = FORMAT_TYPE_UBYTE + (spec->flags & SIGN);
2447         } else if (qualifier == 'h') {
2448                 BUILD_BUG_ON(FORMAT_TYPE_USHORT + SIGN != FORMAT_TYPE_SHORT);
2449                 spec->type = FORMAT_TYPE_USHORT + (spec->flags & SIGN);
2450         } else {
2451                 BUILD_BUG_ON(FORMAT_TYPE_UINT + SIGN != FORMAT_TYPE_INT);
2452                 spec->type = FORMAT_TYPE_UINT + (spec->flags & SIGN);
2453         }
2454
2455         return ++fmt - start;
2456 }
2457
2458 static void
2459 set_field_width(struct printf_spec *spec, int width)
2460 {
2461         spec->field_width = width;
2462         if (WARN_ONCE(spec->field_width != width, "field width %d too large", width)) {
2463                 spec->field_width = clamp(width, -FIELD_WIDTH_MAX, FIELD_WIDTH_MAX);
2464         }
2465 }
2466
2467 static void
2468 set_precision(struct printf_spec *spec, int prec)
2469 {
2470         spec->precision = prec;
2471         if (WARN_ONCE(spec->precision != prec, "precision %d too large", prec)) {
2472                 spec->precision = clamp(prec, 0, PRECISION_MAX);
2473         }
2474 }
2475
2476 /**
2477  * vsnprintf - Format a string and place it in a buffer
2478  * @buf: The buffer to place the result into
2479  * @size: The size of the buffer, including the trailing null space
2480  * @fmt: The format string to use
2481  * @args: Arguments for the format string
2482  *
2483  * This function generally follows C99 vsnprintf, but has some
2484  * extensions and a few limitations:
2485  *
2486  *  - ``%n`` is unsupported
2487  *  - ``%p*`` is handled by pointer()
2488  *
2489  * See pointer() or Documentation/core-api/printk-formats.rst for more
2490  * extensive description.
2491  *
2492  * **Please update the documentation in both places when making changes**
2493  *
2494  * The return value is the number of characters which would
2495  * be generated for the given input, excluding the trailing
2496  * '\0', as per ISO C99. If you want to have the exact
2497  * number of characters written into @buf as return value
2498  * (not including the trailing '\0'), use vscnprintf(). If the
2499  * return is greater than or equal to @size, the resulting
2500  * string is truncated.
2501  *
2502  * If you're not already dealing with a va_list consider using snprintf().
2503  */
2504 int vsnprintf(char *buf, size_t size, const char *fmt, va_list args)
2505 {
2506         unsigned long long num;
2507         char *str, *end;
2508         struct printf_spec spec = {0};
2509
2510         /* Reject out-of-range values early.  Large positive sizes are
2511            used for unknown buffer sizes. */
2512         if (WARN_ON_ONCE(size > INT_MAX))
2513                 return 0;
2514
2515         str = buf;
2516         end = buf + size;
2517
2518         /* Make sure end is always >= buf */
2519         if (end < buf) {
2520                 end = ((void *)-1);
2521                 size = end - buf;
2522         }
2523
2524         while (*fmt) {
2525                 const char *old_fmt = fmt;
2526                 int read = format_decode(fmt, &spec);
2527
2528                 fmt += read;
2529
2530                 switch (spec.type) {
2531                 case FORMAT_TYPE_NONE: {
2532                         int copy = read;
2533                         if (str < end) {
2534                                 if (copy > end - str)
2535                                         copy = end - str;
2536                                 memcpy(str, old_fmt, copy);
2537                         }
2538                         str += read;
2539                         break;
2540                 }
2541
2542                 case FORMAT_TYPE_WIDTH:
2543                         set_field_width(&spec, va_arg(args, int));
2544                         break;
2545
2546                 case FORMAT_TYPE_PRECISION:
2547                         set_precision(&spec, va_arg(args, int));
2548                         break;
2549
2550                 case FORMAT_TYPE_CHAR: {
2551                         char c;
2552
2553                         if (!(spec.flags & LEFT)) {
2554                                 while (--spec.field_width > 0) {
2555                                         if (str < end)
2556                                                 *str = ' ';
2557                                         ++str;
2558
2559                                 }
2560                         }
2561                         c = (unsigned char) va_arg(args, int);
2562                         if (str < end)
2563                                 *str = c;
2564                         ++str;
2565                         while (--spec.field_width > 0) {
2566                                 if (str < end)
2567                                         *str = ' ';
2568                                 ++str;
2569                         }
2570                         break;
2571                 }
2572
2573                 case FORMAT_TYPE_STR:
2574                         str = string(str, end, va_arg(args, char *), spec);
2575                         break;
2576
2577                 case FORMAT_TYPE_PTR:
2578                         str = pointer(fmt, str, end, va_arg(args, void *),
2579                                       spec);
2580                         while (isalnum(*fmt))
2581                                 fmt++;
2582                         break;
2583
2584                 case FORMAT_TYPE_PERCENT_CHAR:
2585                         if (str < end)
2586                                 *str = '%';
2587                         ++str;
2588                         break;
2589
2590                 case FORMAT_TYPE_INVALID:
2591                         /*
2592                          * Presumably the arguments passed gcc's type
2593                          * checking, but there is no safe or sane way
2594                          * for us to continue parsing the format and
2595                          * fetching from the va_list; the remaining
2596                          * specifiers and arguments would be out of
2597                          * sync.
2598                          */
2599                         goto out;
2600
2601                 default:
2602                         switch (spec.type) {
2603                         case FORMAT_TYPE_LONG_LONG:
2604                                 num = va_arg(args, long long);
2605                                 break;
2606                         case FORMAT_TYPE_ULONG:
2607                                 num = va_arg(args, unsigned long);
2608                                 break;
2609                         case FORMAT_TYPE_LONG:
2610                                 num = va_arg(args, long);
2611                                 break;
2612                         case FORMAT_TYPE_SIZE_T:
2613                                 if (spec.flags & SIGN)
2614                                         num = va_arg(args, ssize_t);
2615                                 else
2616                                         num = va_arg(args, size_t);
2617                                 break;
2618                         case FORMAT_TYPE_PTRDIFF:
2619                                 num = va_arg(args, ptrdiff_t);
2620                                 break;
2621                         case FORMAT_TYPE_UBYTE:
2622                                 num = (unsigned char) va_arg(args, int);
2623                                 break;
2624                         case FORMAT_TYPE_BYTE:
2625                                 num = (signed char) va_arg(args, int);
2626                                 break;
2627                         case FORMAT_TYPE_USHORT:
2628                                 num = (unsigned short) va_arg(args, int);
2629                                 break;
2630                         case FORMAT_TYPE_SHORT:
2631                                 num = (short) va_arg(args, int);
2632                                 break;
2633                         case FORMAT_TYPE_INT:
2634                                 num = (int) va_arg(args, int);
2635                                 break;
2636                         default:
2637                                 num = va_arg(args, unsigned int);
2638                         }
2639
2640                         str = number(str, end, num, spec);
2641                 }
2642         }
2643
2644 out:
2645         if (size > 0) {
2646                 if (str < end)
2647                         *str = '\0';
2648                 else
2649                         end[-1] = '\0';
2650         }
2651
2652         /* the trailing null byte doesn't count towards the total */
2653         return str-buf;
2654
2655 }
2656 EXPORT_SYMBOL(vsnprintf);
2657
2658 /**
2659  * vscnprintf - Format a string and place it in a buffer
2660  * @buf: The buffer to place the result into
2661  * @size: The size of the buffer, including the trailing null space
2662  * @fmt: The format string to use
2663  * @args: Arguments for the format string
2664  *
2665  * The return value is the number of characters which have been written into
2666  * the @buf not including the trailing '\0'. If @size is == 0 the function
2667  * returns 0.
2668  *
2669  * If you're not already dealing with a va_list consider using scnprintf().
2670  *
2671  * See the vsnprintf() documentation for format string extensions over C99.
2672  */
2673 int vscnprintf(char *buf, size_t size, const char *fmt, va_list args)
2674 {
2675         int i;
2676
2677         i = vsnprintf(buf, size, fmt, args);
2678
2679         if (likely(i < size))
2680                 return i;
2681         if (size != 0)
2682                 return size - 1;
2683         return 0;
2684 }
2685 EXPORT_SYMBOL(vscnprintf);
2686
2687 /**
2688  * snprintf - Format a string and place it in a buffer
2689  * @buf: The buffer to place the result into
2690  * @size: The size of the buffer, including the trailing null space
2691  * @fmt: The format string to use
2692  * @...: Arguments for the format string
2693  *
2694  * The return value is the number of characters which would be
2695  * generated for the given input, excluding the trailing null,
2696  * as per ISO C99.  If the return is greater than or equal to
2697  * @size, the resulting string is truncated.
2698  *
2699  * See the vsnprintf() documentation for format string extensions over C99.
2700  */
2701 int snprintf(char *buf, size_t size, const char *fmt, ...)
2702 {
2703         va_list args;
2704         int i;
2705
2706         va_start(args, fmt);
2707         i = vsnprintf(buf, size, fmt, args);
2708         va_end(args);
2709
2710         return i;
2711 }
2712 EXPORT_SYMBOL(snprintf);
2713
2714 /**
2715  * scnprintf - Format a string and place it in a buffer
2716  * @buf: The buffer to place the result into
2717  * @size: The size of the buffer, including the trailing null space
2718  * @fmt: The format string to use
2719  * @...: Arguments for the format string
2720  *
2721  * The return value is the number of characters written into @buf not including
2722  * the trailing '\0'. If @size is == 0 the function returns 0.
2723  */
2724
2725 int scnprintf(char *buf, size_t size, const char *fmt, ...)
2726 {
2727         va_list args;
2728         int i;
2729
2730         va_start(args, fmt);
2731         i = vscnprintf(buf, size, fmt, args);
2732         va_end(args);
2733
2734         return i;
2735 }
2736 EXPORT_SYMBOL(scnprintf);
2737
2738 /**
2739  * vsprintf - Format a string and place it in a buffer
2740  * @buf: The buffer to place the result into
2741  * @fmt: The format string to use
2742  * @args: Arguments for the format string
2743  *
2744  * The function returns the number of characters written
2745  * into @buf. Use vsnprintf() or vscnprintf() in order to avoid
2746  * buffer overflows.
2747  *
2748  * If you're not already dealing with a va_list consider using sprintf().
2749  *
2750  * See the vsnprintf() documentation for format string extensions over C99.
2751  */
2752 int vsprintf(char *buf, const char *fmt, va_list args)
2753 {
2754         return vsnprintf(buf, INT_MAX, fmt, args);
2755 }
2756 EXPORT_SYMBOL(vsprintf);
2757
2758 /**
2759  * sprintf - Format a string and place it in a buffer
2760  * @buf: The buffer to place the result into
2761  * @fmt: The format string to use
2762  * @...: Arguments for the format string
2763  *
2764  * The function returns the number of characters written
2765  * into @buf. Use snprintf() or scnprintf() in order to avoid
2766  * buffer overflows.
2767  *
2768  * See the vsnprintf() documentation for format string extensions over C99.
2769  */
2770 int sprintf(char *buf, const char *fmt, ...)
2771 {
2772         va_list args;
2773         int i;
2774
2775         va_start(args, fmt);
2776         i = vsnprintf(buf, INT_MAX, fmt, args);
2777         va_end(args);
2778
2779         return i;
2780 }
2781 EXPORT_SYMBOL(sprintf);
2782
2783 #ifdef CONFIG_BINARY_PRINTF
2784 /*
2785  * bprintf service:
2786  * vbin_printf() - VA arguments to binary data
2787  * bstr_printf() - Binary data to text string
2788  */
2789
2790 /**
2791  * vbin_printf - Parse a format string and place args' binary value in a buffer
2792  * @bin_buf: The buffer to place args' binary value
2793  * @size: The size of the buffer(by words(32bits), not characters)
2794  * @fmt: The format string to use
2795  * @args: Arguments for the format string
2796  *
2797  * The format follows C99 vsnprintf, except %n is ignored, and its argument
2798  * is skipped.
2799  *
2800  * The return value is the number of words(32bits) which would be generated for
2801  * the given input.
2802  *
2803  * NOTE:
2804  * If the return value is greater than @size, the resulting bin_buf is NOT
2805  * valid for bstr_printf().
2806  */
2807 int vbin_printf(u32 *bin_buf, size_t size, const char *fmt, va_list args)
2808 {
2809         struct printf_spec spec = {0};
2810         char *str, *end;
2811         int width;
2812
2813         str = (char *)bin_buf;
2814         end = (char *)(bin_buf + size);
2815
2816 #define save_arg(type)                                                  \
2817 ({                                                                      \
2818         unsigned long long value;                                       \
2819         if (sizeof(type) == 8) {                                        \
2820                 unsigned long long val8;                                \
2821                 str = PTR_ALIGN(str, sizeof(u32));                      \
2822                 val8 = va_arg(args, unsigned long long);                \
2823                 if (str + sizeof(type) <= end) {                        \
2824                         *(u32 *)str = *(u32 *)&val8;                    \
2825                         *(u32 *)(str + 4) = *((u32 *)&val8 + 1);        \
2826                 }                                                       \
2827                 value = val8;                                           \
2828         } else {                                                        \
2829                 unsigned int val4;                                      \
2830                 str = PTR_ALIGN(str, sizeof(type));                     \
2831                 val4 = va_arg(args, int);                               \
2832                 if (str + sizeof(type) <= end)                          \
2833                         *(typeof(type) *)str = (type)(long)val4;        \
2834                 value = (unsigned long long)val4;                       \
2835         }                                                               \
2836         str += sizeof(type);                                            \
2837         value;                                                          \
2838 })
2839
2840         while (*fmt) {
2841                 int read = format_decode(fmt, &spec);
2842
2843                 fmt += read;
2844
2845                 switch (spec.type) {
2846                 case FORMAT_TYPE_NONE:
2847                 case FORMAT_TYPE_PERCENT_CHAR:
2848                         break;
2849                 case FORMAT_TYPE_INVALID:
2850                         goto out;
2851
2852                 case FORMAT_TYPE_WIDTH:
2853                 case FORMAT_TYPE_PRECISION:
2854                         width = (int)save_arg(int);
2855                         /* Pointers may require the width */
2856                         if (*fmt == 'p')
2857                                 set_field_width(&spec, width);
2858                         break;
2859
2860                 case FORMAT_TYPE_CHAR:
2861                         save_arg(char);
2862                         break;
2863
2864                 case FORMAT_TYPE_STR: {
2865                         const char *save_str = va_arg(args, char *);
2866                         const char *err_msg;
2867                         size_t len;
2868
2869                         err_msg = check_pointer_msg(save_str);
2870                         if (err_msg)
2871                                 save_str = err_msg;
2872
2873                         len = strlen(save_str) + 1;
2874                         if (str + len < end)
2875                                 memcpy(str, save_str, len);
2876                         str += len;
2877                         break;
2878                 }
2879
2880                 case FORMAT_TYPE_PTR:
2881                         /* Dereferenced pointers must be done now */
2882                         switch (*fmt) {
2883                         /* Dereference of functions is still OK */
2884                         case 'S':
2885                         case 's':
2886                         case 'x':
2887                         case 'K':
2888                         case 'e':
2889                                 save_arg(void *);
2890                                 break;
2891                         default:
2892                                 if (!isalnum(*fmt)) {
2893                                         save_arg(void *);
2894                                         break;
2895                                 }
2896                                 str = pointer(fmt, str, end, va_arg(args, void *),
2897                                               spec);
2898                                 if (str + 1 < end)
2899                                         *str++ = '\0';
2900                                 else
2901                                         end[-1] = '\0'; /* Must be nul terminated */
2902                         }
2903                         /* skip all alphanumeric pointer suffixes */
2904                         while (isalnum(*fmt))
2905                                 fmt++;
2906                         break;
2907
2908                 default:
2909                         switch (spec.type) {
2910
2911                         case FORMAT_TYPE_LONG_LONG:
2912                                 save_arg(long long);
2913                                 break;
2914                         case FORMAT_TYPE_ULONG:
2915                         case FORMAT_TYPE_LONG:
2916                                 save_arg(unsigned long);
2917                                 break;
2918                         case FORMAT_TYPE_SIZE_T:
2919                                 save_arg(size_t);
2920                                 break;
2921                         case FORMAT_TYPE_PTRDIFF:
2922                                 save_arg(ptrdiff_t);
2923                                 break;
2924                         case FORMAT_TYPE_UBYTE:
2925                         case FORMAT_TYPE_BYTE:
2926                                 save_arg(char);
2927                                 break;
2928                         case FORMAT_TYPE_USHORT:
2929                         case FORMAT_TYPE_SHORT:
2930                                 save_arg(short);
2931                                 break;
2932                         default:
2933                                 save_arg(int);
2934                         }
2935                 }
2936         }
2937
2938 out:
2939         return (u32 *)(PTR_ALIGN(str, sizeof(u32))) - bin_buf;
2940 #undef save_arg
2941 }
2942 EXPORT_SYMBOL_GPL(vbin_printf);
2943
2944 /**
2945  * bstr_printf - Format a string from binary arguments and place it in a buffer
2946  * @buf: The buffer to place the result into
2947  * @size: The size of the buffer, including the trailing null space
2948  * @fmt: The format string to use
2949  * @bin_buf: Binary arguments for the format string
2950  *
2951  * This function like C99 vsnprintf, but the difference is that vsnprintf gets
2952  * arguments from stack, and bstr_printf gets arguments from @bin_buf which is
2953  * a binary buffer that generated by vbin_printf.
2954  *
2955  * The format follows C99 vsnprintf, but has some extensions:
2956  *  see vsnprintf comment for details.
2957  *
2958  * The return value is the number of characters which would
2959  * be generated for the given input, excluding the trailing
2960  * '\0', as per ISO C99. If you want to have the exact
2961  * number of characters written into @buf as return value
2962  * (not including the trailing '\0'), use vscnprintf(). If the
2963  * return is greater than or equal to @size, the resulting
2964  * string is truncated.
2965  */
2966 int bstr_printf(char *buf, size_t size, const char *fmt, const u32 *bin_buf)
2967 {
2968         struct printf_spec spec = {0};
2969         char *str, *end;
2970         const char *args = (const char *)bin_buf;
2971
2972         if (WARN_ON_ONCE(size > INT_MAX))
2973                 return 0;
2974
2975         str = buf;
2976         end = buf + size;
2977
2978 #define get_arg(type)                                                   \
2979 ({                                                                      \
2980         typeof(type) value;                                             \
2981         if (sizeof(type) == 8) {                                        \
2982                 args = PTR_ALIGN(args, sizeof(u32));                    \
2983                 *(u32 *)&value = *(u32 *)args;                          \
2984                 *((u32 *)&value + 1) = *(u32 *)(args + 4);              \
2985         } else {                                                        \
2986                 args = PTR_ALIGN(args, sizeof(type));                   \
2987                 value = *(typeof(type) *)args;                          \
2988         }                                                               \
2989         args += sizeof(type);                                           \
2990         value;                                                          \
2991 })
2992
2993         /* Make sure end is always >= buf */
2994         if (end < buf) {
2995                 end = ((void *)-1);
2996                 size = end - buf;
2997         }
2998
2999         while (*fmt) {
3000                 const char *old_fmt = fmt;
3001                 int read = format_decode(fmt, &spec);
3002
3003                 fmt += read;
3004
3005                 switch (spec.type) {
3006                 case FORMAT_TYPE_NONE: {
3007                         int copy = read;
3008                         if (str < end) {
3009                                 if (copy > end - str)
3010                                         copy = end - str;
3011                                 memcpy(str, old_fmt, copy);
3012                         }
3013                         str += read;
3014                         break;
3015                 }
3016
3017                 case FORMAT_TYPE_WIDTH:
3018                         set_field_width(&spec, get_arg(int));
3019                         break;
3020
3021                 case FORMAT_TYPE_PRECISION:
3022                         set_precision(&spec, get_arg(int));
3023                         break;
3024
3025                 case FORMAT_TYPE_CHAR: {
3026                         char c;
3027
3028                         if (!(spec.flags & LEFT)) {
3029                                 while (--spec.field_width > 0) {
3030                                         if (str < end)
3031                                                 *str = ' ';
3032                                         ++str;
3033                                 }
3034                         }
3035                         c = (unsigned char) get_arg(char);
3036                         if (str < end)
3037                                 *str = c;
3038                         ++str;
3039                         while (--spec.field_width > 0) {
3040                                 if (str < end)
3041                                         *str = ' ';
3042                                 ++str;
3043                         }
3044                         break;
3045                 }
3046
3047                 case FORMAT_TYPE_STR: {
3048                         const char *str_arg = args;
3049                         args += strlen(str_arg) + 1;
3050                         str = string(str, end, (char *)str_arg, spec);
3051                         break;
3052                 }
3053
3054                 case FORMAT_TYPE_PTR: {
3055                         bool process = false;
3056                         int copy, len;
3057                         /* Non function dereferences were already done */
3058                         switch (*fmt) {
3059                         case 'S':
3060                         case 's':
3061                         case 'F':
3062                         case 'f':
3063                         case 'x':
3064                         case 'K':
3065                         case 'e':
3066                                 process = true;
3067                                 break;
3068                         default:
3069                                 if (!isalnum(*fmt)) {
3070                                         process = true;
3071                                         break;
3072                                 }
3073                                 /* Pointer dereference was already processed */
3074                                 if (str < end) {
3075                                         len = copy = strlen(args);
3076                                         if (copy > end - str)
3077                                                 copy = end - str;
3078                                         memcpy(str, args, copy);
3079                                         str += len;
3080                                         args += len + 1;
3081                                 }
3082                         }
3083                         if (process)
3084                                 str = pointer(fmt, str, end, get_arg(void *), spec);
3085
3086                         while (isalnum(*fmt))
3087                                 fmt++;
3088                         break;
3089                 }
3090
3091                 case FORMAT_TYPE_PERCENT_CHAR:
3092                         if (str < end)
3093                                 *str = '%';
3094                         ++str;
3095                         break;
3096
3097                 case FORMAT_TYPE_INVALID:
3098                         goto out;
3099
3100                 default: {
3101                         unsigned long long num;
3102
3103                         switch (spec.type) {
3104
3105                         case FORMAT_TYPE_LONG_LONG:
3106                                 num = get_arg(long long);
3107                                 break;
3108                         case FORMAT_TYPE_ULONG:
3109                         case FORMAT_TYPE_LONG:
3110                                 num = get_arg(unsigned long);
3111                                 break;
3112                         case FORMAT_TYPE_SIZE_T:
3113                                 num = get_arg(size_t);
3114                                 break;
3115                         case FORMAT_TYPE_PTRDIFF:
3116                                 num = get_arg(ptrdiff_t);
3117                                 break;
3118                         case FORMAT_TYPE_UBYTE:
3119                                 num = get_arg(unsigned char);
3120                                 break;
3121                         case FORMAT_TYPE_BYTE:
3122                                 num = get_arg(signed char);
3123                                 break;
3124                         case FORMAT_TYPE_USHORT:
3125                                 num = get_arg(unsigned short);
3126                                 break;
3127                         case FORMAT_TYPE_SHORT:
3128                                 num = get_arg(short);
3129                                 break;
3130                         case FORMAT_TYPE_UINT:
3131                                 num = get_arg(unsigned int);
3132                                 break;
3133                         default:
3134                                 num = get_arg(int);
3135                         }
3136
3137                         str = number(str, end, num, spec);
3138                 } /* default: */
3139                 } /* switch(spec.type) */
3140         } /* while(*fmt) */
3141
3142 out:
3143         if (size > 0) {
3144                 if (str < end)
3145                         *str = '\0';
3146                 else
3147                         end[-1] = '\0';
3148         }
3149
3150 #undef get_arg
3151
3152         /* the trailing null byte doesn't count towards the total */
3153         return str - buf;
3154 }
3155 EXPORT_SYMBOL_GPL(bstr_printf);
3156
3157 /**
3158  * bprintf - Parse a format string and place args' binary value in a buffer
3159  * @bin_buf: The buffer to place args' binary value
3160  * @size: The size of the buffer(by words(32bits), not characters)
3161  * @fmt: The format string to use
3162  * @...: Arguments for the format string
3163  *
3164  * The function returns the number of words(u32) written
3165  * into @bin_buf.
3166  */
3167 int bprintf(u32 *bin_buf, size_t size, const char *fmt, ...)
3168 {
3169         va_list args;
3170         int ret;
3171
3172         va_start(args, fmt);
3173         ret = vbin_printf(bin_buf, size, fmt, args);
3174         va_end(args);
3175
3176         return ret;
3177 }
3178 EXPORT_SYMBOL_GPL(bprintf);
3179
3180 #endif /* CONFIG_BINARY_PRINTF */
3181
3182 /**
3183  * vsscanf - Unformat a buffer into a list of arguments
3184  * @buf:        input buffer
3185  * @fmt:        format of buffer
3186  * @args:       arguments
3187  */
3188 int vsscanf(const char *buf, const char *fmt, va_list args)
3189 {
3190         const char *str = buf;
3191         char *next;
3192         char digit;
3193         int num = 0;
3194         u8 qualifier;
3195         unsigned int base;
3196         union {
3197                 long long s;
3198                 unsigned long long u;
3199         } val;
3200         s16 field_width;
3201         bool is_sign;
3202
3203         while (*fmt) {
3204                 /* skip any white space in format */
3205                 /* white space in format matchs any amount of
3206                  * white space, including none, in the input.
3207                  */
3208                 if (isspace(*fmt)) {
3209                         fmt = skip_spaces(++fmt);
3210                         str = skip_spaces(str);
3211                 }
3212
3213                 /* anything that is not a conversion must match exactly */
3214                 if (*fmt != '%' && *fmt) {
3215                         if (*fmt++ != *str++)
3216                                 break;
3217                         continue;
3218                 }
3219
3220                 if (!*fmt)
3221                         break;
3222                 ++fmt;
3223
3224                 /* skip this conversion.
3225                  * advance both strings to next white space
3226                  */
3227                 if (*fmt == '*') {
3228                         if (!*str)
3229                                 break;
3230                         while (!isspace(*fmt) && *fmt != '%' && *fmt) {
3231                                 /* '%*[' not yet supported, invalid format */
3232                                 if (*fmt == '[')
3233                                         return num;
3234                                 fmt++;
3235                         }
3236                         while (!isspace(*str) && *str)
3237                                 str++;
3238                         continue;
3239                 }
3240
3241                 /* get field width */
3242                 field_width = -1;
3243                 if (isdigit(*fmt)) {
3244                         field_width = skip_atoi(&fmt);
3245                         if (field_width <= 0)
3246                                 break;
3247                 }
3248
3249                 /* get conversion qualifier */
3250                 qualifier = -1;
3251                 if (*fmt == 'h' || _tolower(*fmt) == 'l' ||
3252                     *fmt == 'z') {
3253                         qualifier = *fmt++;
3254                         if (unlikely(qualifier == *fmt)) {
3255                                 if (qualifier == 'h') {
3256                                         qualifier = 'H';
3257                                         fmt++;
3258                                 } else if (qualifier == 'l') {
3259                                         qualifier = 'L';
3260                                         fmt++;
3261                                 }
3262                         }
3263                 }
3264
3265                 if (!*fmt)
3266                         break;
3267
3268                 if (*fmt == 'n') {
3269                         /* return number of characters read so far */
3270                         *va_arg(args, int *) = str - buf;
3271                         ++fmt;
3272                         continue;
3273                 }
3274
3275                 if (!*str)
3276                         break;
3277
3278                 base = 10;
3279                 is_sign = false;
3280
3281                 switch (*fmt++) {
3282                 case 'c':
3283                 {
3284                         char *s = (char *)va_arg(args, char*);
3285                         if (field_width == -1)
3286                                 field_width = 1;
3287                         do {
3288                                 *s++ = *str++;
3289                         } while (--field_width > 0 && *str);
3290                         num++;
3291                 }
3292                 continue;
3293                 case 's':
3294                 {
3295                         char *s = (char *)va_arg(args, char *);
3296                         if (field_width == -1)
3297                                 field_width = SHRT_MAX;
3298                         /* first, skip leading white space in buffer */
3299                         str = skip_spaces(str);
3300
3301                         /* now copy until next white space */
3302                         while (*str && !isspace(*str) && field_width--)
3303                                 *s++ = *str++;
3304                         *s = '\0';
3305                         num++;
3306                 }
3307                 continue;
3308                 /*
3309                  * Warning: This implementation of the '[' conversion specifier
3310                  * deviates from its glibc counterpart in the following ways:
3311                  * (1) It does NOT support ranges i.e. '-' is NOT a special
3312                  *     character
3313                  * (2) It cannot match the closing bracket ']' itself
3314                  * (3) A field width is required
3315                  * (4) '%*[' (discard matching input) is currently not supported
3316                  *
3317                  * Example usage:
3318                  * ret = sscanf("00:0a:95","%2[^:]:%2[^:]:%2[^:]",
3319                  *              buf1, buf2, buf3);
3320                  * if (ret < 3)
3321                  *    // etc..
3322                  */
3323                 case '[':
3324                 {
3325                         char *s = (char *)va_arg(args, char *);
3326                         DECLARE_BITMAP(set, 256) = {0};
3327                         unsigned int len = 0;
3328                         bool negate = (*fmt == '^');
3329
3330                         /* field width is required */
3331                         if (field_width == -1)
3332                                 return num;
3333
3334                         if (negate)
3335                                 ++fmt;
3336
3337                         for ( ; *fmt && *fmt != ']'; ++fmt, ++len)
3338                                 set_bit((u8)*fmt, set);
3339
3340                         /* no ']' or no character set found */
3341                         if (!*fmt || !len)
3342                                 return num;
3343                         ++fmt;
3344
3345                         if (negate) {
3346                                 bitmap_complement(set, set, 256);
3347                                 /* exclude null '\0' byte */
3348                                 clear_bit(0, set);
3349                         }
3350
3351                         /* match must be non-empty */
3352                         if (!test_bit((u8)*str, set))
3353                                 return num;
3354
3355                         while (test_bit((u8)*str, set) && field_width--)
3356                                 *s++ = *str++;
3357                         *s = '\0';
3358                         ++num;
3359                 }
3360                 continue;
3361                 case 'o':
3362                         base = 8;
3363                         break;
3364                 case 'x':
3365                 case 'X':
3366                         base = 16;
3367                         break;
3368                 case 'i':
3369                         base = 0;
3370                         /* fall through */
3371                 case 'd':
3372                         is_sign = true;
3373                         /* fall through */
3374                 case 'u':
3375                         break;
3376                 case '%':
3377                         /* looking for '%' in str */
3378                         if (*str++ != '%')
3379                                 return num;
3380                         continue;
3381                 default:
3382                         /* invalid format; stop here */
3383                         return num;
3384                 }
3385
3386                 /* have some sort of integer conversion.
3387                  * first, skip white space in buffer.
3388                  */
3389                 str = skip_spaces(str);
3390
3391                 digit = *str;
3392                 if (is_sign && digit == '-')
3393                         digit = *(str + 1);
3394
3395                 if (!digit
3396                     || (base == 16 && !isxdigit(digit))
3397                     || (base == 10 && !isdigit(digit))
3398                     || (base == 8 && (!isdigit(digit) || digit > '7'))
3399                     || (base == 0 && !isdigit(digit)))
3400                         break;
3401
3402                 if (is_sign)
3403                         val.s = qualifier != 'L' ?
3404                                 simple_strtol(str, &next, base) :
3405                                 simple_strtoll(str, &next, base);
3406                 else
3407                         val.u = qualifier != 'L' ?
3408                                 simple_strtoul(str, &next, base) :
3409                                 simple_strtoull(str, &next, base);
3410
3411                 if (field_width > 0 && next - str > field_width) {
3412                         if (base == 0)
3413                                 _parse_integer_fixup_radix(str, &base);
3414                         while (next - str > field_width) {
3415                                 if (is_sign)
3416                                         val.s = div_s64(val.s, base);
3417                                 else
3418                                         val.u = div_u64(val.u, base);
3419                                 --next;
3420                         }
3421                 }
3422
3423                 switch (qualifier) {
3424                 case 'H':       /* that's 'hh' in format */
3425                         if (is_sign)
3426                                 *va_arg(args, signed char *) = val.s;
3427                         else
3428                                 *va_arg(args, unsigned char *) = val.u;
3429                         break;
3430                 case 'h':
3431                         if (is_sign)
3432                                 *va_arg(args, short *) = val.s;
3433                         else
3434                                 *va_arg(args, unsigned short *) = val.u;
3435                         break;
3436                 case 'l':
3437                         if (is_sign)
3438                                 *va_arg(args, long *) = val.s;
3439                         else
3440                                 *va_arg(args, unsigned long *) = val.u;
3441                         break;
3442                 case 'L':
3443                         if (is_sign)
3444                                 *va_arg(args, long long *) = val.s;
3445                         else
3446                                 *va_arg(args, unsigned long long *) = val.u;
3447                         break;
3448                 case 'z':
3449                         *va_arg(args, size_t *) = val.u;
3450                         break;
3451                 default:
3452                         if (is_sign)
3453                                 *va_arg(args, int *) = val.s;
3454                         else
3455                                 *va_arg(args, unsigned int *) = val.u;
3456                         break;
3457                 }
3458                 num++;
3459
3460                 if (!next)
3461                         break;
3462                 str = next;
3463         }
3464
3465         return num;
3466 }
3467 EXPORT_SYMBOL(vsscanf);
3468
3469 /**
3470  * sscanf - Unformat a buffer into a list of arguments
3471  * @buf:        input buffer
3472  * @fmt:        formatting of buffer
3473  * @...:        resulting arguments
3474  */
3475 int sscanf(const char *buf, const char *fmt, ...)
3476 {
3477         va_list args;
3478         int i;
3479
3480         va_start(args, fmt);
3481         i = vsscanf(buf, fmt, args);
3482         va_end(args);
3483
3484         return i;
3485 }
3486 EXPORT_SYMBOL(sscanf);