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/time.h>
  38 #include <linux/uuid.h>
  39 #include <linux/of.h>
  40 #include <net/addrconf.h>
  41 #include <linux/siphash.h>
  42 #include <linux/compiler.h>
  43 #include <linux/property.h>
  44 #ifdef CONFIG_BLOCK
  45 #include <linux/blkdev.h>
  46 #endif
  47
  48 #include "../mm/internal.h"     /* For the trace_print_flags arrays */
  49
  50 #include <asm/page.h>           /* for PAGE_SIZE */
  51 #include <asm/byteorder.h>      /* cpu_to_le16 */
  52
  53 #include <linux/string_helpers.h>
  54 #include "kstrtox.h"
  55
  56 /**
  57  * simple_strtoull - convert a string to an unsigned long long
  58  * @cp: The start of the string
  59  * @endp: A pointer to the end of the parsed string will be placed here
  60  * @base: The number base to use
  61  *
  62  * This function has caveats. Please use kstrtoull instead.
  63  */
  64 unsigned long long simple_strtoull(const char *cp, char **endp, unsigned int base)
  65 {
  66         unsigned long long result;
  67         unsigned int rv;
  68
  69         cp = _parse_integer_fixup_radix(cp, &base);
  70         rv = _parse_integer(cp, base, &result);
  71         /* FIXME */
  72         cp += (rv & ~KSTRTOX_OVERFLOW);
  73
  74         if (endp)
  75                 *endp = (char *)cp;
  76
  77         return result;
  78 }
  79 EXPORT_SYMBOL(simple_strtoull);
  80
  81 /**
  82  * simple_strtoul - convert a string to an unsigned long
  83  * @cp: The start of the string
  84  * @endp: A pointer to the end of the parsed string will be placed here
  85  * @base: The number base to use
  86  *
  87  * This function has caveats. Please use kstrtoul instead.
  88  */
  89 unsigned long simple_strtoul(const char *cp, char **endp, unsigned int base)
  90 {
  91         return simple_strtoull(cp, endp, base);
  92 }
  93 EXPORT_SYMBOL(simple_strtoul);
  94
  95 /**
  96  * simple_strtol - convert a string to a signed long
  97  * @cp: The start of the string
  98  * @endp: A pointer to the end of the parsed string will be placed here
  99  * @base: The number base to use
 100  *
 101  * This function has caveats. Please use kstrtol instead.
 102  */
 103 long simple_strtol(const char *cp, char **endp, unsigned int base)
 104 {
 105         if (*cp == '-')
 106                 return -simple_strtoul(cp + 1, endp, base);
 107
 108         return simple_strtoul(cp, endp, base);
 109 }
 110 EXPORT_SYMBOL(simple_strtol);
 111
 112 /**
 113  * simple_strtoll - convert a string to a signed long long
 114  * @cp: The start of the string
 115  * @endp: A pointer to the end of the parsed string will be placed here
 116  * @base: The number base to use
 117  *
 118  * This function has caveats. Please use kstrtoll instead.
 119  */
 120 long long simple_strtoll(const char *cp, char **endp, unsigned int base)
 121 {
 122         if (*cp == '-')
 123                 return -simple_strtoull(cp + 1, endp, base);
 124
 125         return simple_strtoull(cp, endp, base);
 126 }
 127 EXPORT_SYMBOL(simple_strtoll);
 128
 129 static noinline_for_stack
 130 int skip_atoi(const char **s)
 131 {
 132         int i = 0;
 133
 134         do {
 135                 i = i*10 + *((*s)++) - '0';
 136         } while (isdigit(**s));
 137
 138         return i;
 139 }
 140
 141 /*
 142  * Decimal conversion is by far the most typical, and is used for
 143  * /proc and /sys data. This directly impacts e.g. top performance
 144  * with many processes running. We optimize it for speed by emitting
 145  * two characters at a time, using a 200 byte lookup table. This
 146  * roughly halves the number of multiplications compared to computing
 147  * the digits one at a time. Implementation strongly inspired by the
 148  * previous version, which in turn used ideas described at
 149  * <http://www.cs.uiowa.edu/~jones/bcd/divide.html> (with permission
 150  * from the author, Douglas W. Jones).
 151  *
 152  * It turns out there is precisely one 26 bit fixed-point
 153  * approximation a of 64/100 for which x/100 == (x * (u64)a) >> 32
 154  * holds for all x in [0, 10^8-1], namely a = 0x28f5c29. The actual
 155  * range happens to be somewhat larger (x <= 1073741898), but that's
 156  * irrelevant for our purpose.
 157  *
 158  * For dividing a number in the range [10^4, 10^6-1] by 100, we still
 159  * need a 32x32->64 bit multiply, so we simply use the same constant.
 160  *
 161  * For dividing a number in the range [100, 10^4-1] by 100, there are
 162  * several options. The simplest is (x * 0x147b) >> 19, which is valid
 163  * for all x <= 43698.
 164  */
 165
 166 static const u16 decpair[100] = {
 167 #define _(x) (__force u16) cpu_to_le16(((x % 10) | ((x / 10) << 8)) + 0x3030)
 168         _( 0), _( 1), _( 2), _( 3), _( 4), _( 5), _( 6), _( 7), _( 8), _( 9),
 169         _(10), _(11), _(12), _(13), _(14), _(15), _(16), _(17), _(18), _(19),
 170         _(20), _(21), _(22), _(23), _(24), _(25), _(26), _(27), _(28), _(29),
 171         _(30), _(31), _(32), _(33), _(34), _(35), _(36), _(37), _(38), _(39),
 172         _(40), _(41), _(42), _(43), _(44), _(45), _(46), _(47), _(48), _(49),
 173         _(50), _(51), _(52), _(53), _(54), _(55), _(56), _(57), _(58), _(59),
 174         _(60), _(61), _(62), _(63), _(64), _(65), _(66), _(67), _(68), _(69),
 175         _(70), _(71), _(72), _(73), _(74), _(75), _(76), _(77), _(78), _(79),
 176         _(80), _(81), _(82), _(83), _(84), _(85), _(86), _(87), _(88), _(89),
 177         _(90), _(91), _(92), _(93), _(94), _(95), _(96), _(97), _(98), _(99),
 178 #undef _
 179 };
 180
 181 /*
 182  * This will print a single '0' even if r == 0, since we would
 183  * immediately jump to out_r where two 0s would be written but only
 184  * one of them accounted for in buf. This is needed by ip4_string
 185  * below. All other callers pass a non-zero value of r.
 186 */
 187 static noinline_for_stack
 188 char *put_dec_trunc8(char *buf, unsigned r)
 189 {
 190         unsigned q;
 191
 192         /* 1 <= r < 10^8 */
 193         if (r < 100)
 194                 goto out_r;
 195
 196         /* 100 <= r < 10^8 */
 197         q = (r * (u64)0x28f5c29) >> 32;
 198         *((u16 *)buf) = decpair[r - 100*q];
 199         buf += 2;
 200
 201         /* 1 <= q < 10^6 */
 202         if (q < 100)
 203                 goto out_q;
 204
 205         /*  100 <= q < 10^6 */
 206         r = (q * (u64)0x28f5c29) >> 32;
 207         *((u16 *)buf) = decpair[q - 100*r];
 208         buf += 2;
 209
 210         /* 1 <= r < 10^4 */
 211         if (r < 100)
 212                 goto out_r;
 213
 214         /* 100 <= r < 10^4 */
 215         q = (r * 0x147b) >> 19;
 216         *((u16 *)buf) = decpair[r - 100*q];
 217         buf += 2;
 218 out_q:
 219         /* 1 <= q < 100 */
 220         r = q;
 221 out_r:
 222         /* 1 <= r < 100 */
 223         *((u16 *)buf) = decpair[r];
 224         buf += r < 10 ? 1 : 2;
 225         return buf;
 226 }
 227
 228 #if BITS_PER_LONG == 64 && BITS_PER_LONG_LONG == 64
 229 static noinline_for_stack
 230 char *put_dec_full8(char *buf, unsigned r)
 231 {
 232         unsigned q;
 233
 234         /* 0 <= r < 10^8 */
 235         q = (r * (u64)0x28f5c29) >> 32;
 236         *((u16 *)buf) = decpair[r - 100*q];
 237         buf += 2;
 238
 239         /* 0 <= q < 10^6 */
 240         r = (q * (u64)0x28f5c29) >> 32;
 241         *((u16 *)buf) = decpair[q - 100*r];
 242         buf += 2;
 243
 244         /* 0 <= r < 10^4 */
 245         q = (r * 0x147b) >> 19;
 246         *((u16 *)buf) = decpair[r - 100*q];
 247         buf += 2;
 248
 249         /* 0 <= q < 100 */
 250         *((u16 *)buf) = decpair[q];
 251         buf += 2;
 252         return buf;
 253 }
 254
 255 static noinline_for_stack
 256 char *put_dec(char *buf, unsigned long long n)
 257 {
 258         if (n >= 100*1000*1000)
 259                 buf = put_dec_full8(buf, do_div(n, 100*1000*1000));
 260         /* 1 <= n <= 1.6e11 */
 261         if (n >= 100*1000*1000)
 262                 buf = put_dec_full8(buf, do_div(n, 100*1000*1000));
 263         /* 1 <= n < 1e8 */
 264         return put_dec_trunc8(buf, n);
 265 }
 266
 267 #elif BITS_PER_LONG == 32 && BITS_PER_LONG_LONG == 64
 268
 269 static void
 270 put_dec_full4(char *buf, unsigned r)
 271 {
 272         unsigned q;
 273
 274         /* 0 <= r < 10^4 */
 275         q = (r * 0x147b) >> 19;
 276         *((u16 *)buf) = decpair[r - 100*q];
 277         buf += 2;
 278         /* 0 <= q < 100 */
 279         *((u16 *)buf) = decpair[q];
 280 }
 281
 282 /*
 283  * Call put_dec_full4 on x % 10000, return x / 10000.
 284  * The approximation x/10000 == (x * 0x346DC5D7) >> 43
 285  * holds for all x < 1,128,869,999.  The largest value this
 286  * helper will ever be asked to convert is 1,125,520,955.
 287  * (second call in the put_dec code, assuming n is all-ones).
 288  */
 289 static noinline_for_stack
 290 unsigned put_dec_helper4(char *buf, unsigned x)
 291 {
 292         uint32_t q = (x * (uint64_t)0x346DC5D7) >> 43;
 293
 294         put_dec_full4(buf, x - q * 10000);
 295         return q;
 296 }
 297
 298 /* Based on code by Douglas W. Jones found at
 299  * <http://www.cs.uiowa.edu/~jones/bcd/decimal.html#sixtyfour>
 300  * (with permission from the author).
 301  * Performs no 64-bit division and hence should be fast on 32-bit machines.
 302  */
 303 static
 304 char *put_dec(char *buf, unsigned long long n)
 305 {
 306         uint32_t d3, d2, d1, q, h;
 307
 308         if (n < 100*1000*1000)
 309                 return put_dec_trunc8(buf, n);
 310
 311         d1  = ((uint32_t)n >> 16); /* implicit "& 0xffff" */
 312         h   = (n >> 32);
 313         d2  = (h      ) & 0xffff;
 314         d3  = (h >> 16); /* implicit "& 0xffff" */
 315
 316         /* n = 2^48 d3 + 2^32 d2 + 2^16 d1 + d0
 317              = 281_4749_7671_0656 d3 + 42_9496_7296 d2 + 6_5536 d1 + d0 */
 318         q   = 656 * d3 + 7296 * d2 + 5536 * d1 + ((uint32_t)n & 0xffff);
 319         q = put_dec_helper4(buf, q);
 320
 321         q += 7671 * d3 + 9496 * d2 + 6 * d1;
 322         q = put_dec_helper4(buf+4, q);
 323
 324         q += 4749 * d3 + 42 * d2;
 325         q = put_dec_helper4(buf+8, q);
 326
 327         q += 281 * d3;
 328         buf += 12;
 329         if (q)
 330                 buf = put_dec_trunc8(buf, q);
 331         else while (buf[-1] == '0')
 332                 --buf;
 333
 334         return buf;
 335 }
 336
 337 #endif
 338
 339 /*
 340  * Convert passed number to decimal string.
 341  * Returns the length of string.  On buffer overflow, returns 0.
 342  *
 343  * If speed is not important, use snprintf(). It's easy to read the code.
 344  */
 345 int num_to_str(char *buf, int size, unsigned long long num, unsigned int width)
 346 {
 347         /* put_dec requires 2-byte alignment of the buffer. */
 348         char tmp[sizeof(num) * 3] __aligned(2);
 349         int idx, len;
 350
 351         /* put_dec() may work incorrectly for num = 0 (generate "", not "0") */
 352         if (num <= 9) {
 353                 tmp[0] = '0' + num;
 354                 len = 1;
 355         } else {
 356                 len = put_dec(tmp, num) - tmp;
 357         }
 358
 359         if (len > size || width > size)
 360                 return 0;
 361
 362         if (width > len) {
 363                 width = width - len;
 364                 for (idx = 0; idx < width; idx++)
 365                         buf[idx] = ' ';
 366         } else {
 367                 width = 0;
 368         }
 369
 370         for (idx = 0; idx < len; ++idx)
 371                 buf[idx + width] = tmp[len - idx - 1];
 372
 373         return len + width;
 374 }
 375
 376 #define SIGN    1               /* unsigned/signed, must be 1 */
 377 #define LEFT    2               /* left justified */
 378 #define PLUS    4               /* show plus */
 379 #define SPACE   8               /* space if plus */
 380 #define ZEROPAD 16              /* pad with zero, must be 16 == '0' - ' ' */
 381 #define SMALL   32              /* use lowercase in hex (must be 32 == 0x20) */
 382 #define SPECIAL 64              /* prefix hex with "0x", octal with "0" */
 383
 384 enum format_type {
 385         FORMAT_TYPE_NONE, /* Just a string part */
 386         FORMAT_TYPE_WIDTH,
 387         FORMAT_TYPE_PRECISION,
 388         FORMAT_TYPE_CHAR,
 389         FORMAT_TYPE_STR,
 390         FORMAT_TYPE_PTR,
 391         FORMAT_TYPE_PERCENT_CHAR,
 392         FORMAT_TYPE_INVALID,
 393         FORMAT_TYPE_LONG_LONG,
 394         FORMAT_TYPE_ULONG,
 395         FORMAT_TYPE_LONG,
 396         FORMAT_TYPE_UBYTE,
 397         FORMAT_TYPE_BYTE,
 398         FORMAT_TYPE_USHORT,
 399         FORMAT_TYPE_SHORT,
 400         FORMAT_TYPE_UINT,
 401         FORMAT_TYPE_INT,
 402         FORMAT_TYPE_SIZE_T,
 403         FORMAT_TYPE_PTRDIFF
 404 };
 405
 406 struct printf_spec {
 407         unsigned int    type:8;         /* format_type enum */
 408         signed int      field_width:24; /* width of output field */
 409         unsigned int    flags:8;        /* flags to number() */
 410         unsigned int    base:8;         /* number base, 8, 10 or 16 only */
 411         signed int      precision:16;   /* # of digits/chars */
 412 } __packed;
 413 static_assert(sizeof(struct printf_spec) == 8);
 414
 415 #define FIELD_WIDTH_MAX ((1 << 23) - 1)
 416 #define PRECISION_MAX ((1 << 15) - 1)
 417
 418 static noinline_for_stack
 419 char *number(char *buf, char *end, unsigned long long num,
 420              struct printf_spec spec)
 421 {
 422         /* put_dec requires 2-byte alignment of the buffer. */
 423         char tmp[3 * sizeof(num)] __aligned(2);
 424         char sign;
 425         char locase;
 426         int need_pfx = ((spec.flags & SPECIAL) && spec.base != 10);
 427         int i;
 428         bool is_zero = num == 0LL;
 429         int field_width = spec.field_width;
 430         int precision = spec.precision;
 431
 432         /* locase = 0 or 0x20. ORing digits or letters with 'locase'
 433          * produces same digits or (maybe lowercased) letters */
 434         locase = (spec.flags & SMALL);
 435         if (spec.flags & LEFT)
 436                 spec.flags &= ~ZEROPAD;
 437         sign = 0;
 438         if (spec.flags & SIGN) {
 439                 if ((signed long long)num < 0) {
 440                         sign = '-';
 441                         num = -(signed long long)num;
 442                         field_width--;
 443                 } else if (spec.flags & PLUS) {
 444                         sign = '+';
 445                         field_width--;
 446                 } else if (spec.flags & SPACE) {
 447                         sign = ' ';
 448                         field_width--;
 449                 }
 450         }
 451         if (need_pfx) {
 452                 if (spec.base == 16)
 453                         field_width -= 2;
 454                 else if (!is_zero)
 455                         field_width--;
 456         }
 457
 458         /* generate full string in tmp[], in reverse order */
 459         i = 0;
 460         if (num < spec.base)
 461                 tmp[i++] = hex_asc_upper[num] | locase;
 462         else if (spec.base != 10) { /* 8 or 16 */
 463                 int mask = spec.base - 1;
 464                 int shift = 3;
 465
 466                 if (spec.base == 16)
 467                         shift = 4;
 468                 do {
 469                         tmp[i++] = (hex_asc_upper[((unsigned char)num) & mask] | locase);
 470                         num >>= shift;
 471                 } while (num);
 472         } else { /* base 10 */
 473                 i = put_dec(tmp, num) - tmp;
 474         }
 475
 476         /* printing 100 using %2d gives "100", not "00" */
 477         if (i > precision)
 478                 precision = i;
 479         /* leading space padding */
 480         field_width -= precision;
 481         if (!(spec.flags & (ZEROPAD | LEFT))) {
 482                 while (--field_width >= 0) {
 483                         if (buf < end)
 484                                 *buf = ' ';
 485                         ++buf;
 486                 }
 487         }
 488         /* sign */
 489         if (sign) {
 490                 if (buf < end)
 491                         *buf = sign;
 492                 ++buf;
 493         }
 494         /* "0x" / "0" prefix */
 495         if (need_pfx) {
 496                 if (spec.base == 16 || !is_zero) {
 497                         if (buf < end)
 498                                 *buf = '0';
 499                         ++buf;
 500                 }
 501                 if (spec.base == 16) {
 502                         if (buf < end)
 503                                 *buf = ('X' | locase);
 504                         ++buf;
 505                 }
 506         }
 507         /* zero or space padding */
 508         if (!(spec.flags & LEFT)) {
 509                 char c = ' ' + (spec.flags & ZEROPAD);
 510                 BUILD_BUG_ON(' ' + ZEROPAD != '0');
 511                 while (--field_width >= 0) {
 512                         if (buf < end)
 513                                 *buf = c;
 514                         ++buf;
 515                 }
 516         }
 517         /* hmm even more zero padding? */
 518         while (i <= --precision) {
 519                 if (buf < end)
 520                         *buf = '0';
 521                 ++buf;
 522         }
 523         /* actual digits of result */
 524         while (--i >= 0) {
 525                 if (buf < end)
 526                         *buf = tmp[i];
 527                 ++buf;
 528         }
 529         /* trailing space padding */
 530         while (--field_width >= 0) {
 531                 if (buf < end)
 532                         *buf = ' ';
 533                 ++buf;
 534         }
 535
 536         return buf;
 537 }
 538
 539 static noinline_for_stack
 540 char *special_hex_number(char *buf, char *end, unsigned long long num, int size)
 541 {
 542         struct printf_spec spec;
 543
 544         spec.type = FORMAT_TYPE_PTR;
 545         spec.field_width = 2 + 2 * size;        /* 0x + hex */
 546         spec.flags = SPECIAL | SMALL | ZEROPAD;
 547         spec.base = 16;
 548         spec.precision = -1;
 549
 550         return number(buf, end, num, spec);
 551 }
 552
 553 static void move_right(char *buf, char *end, unsigned len, unsigned spaces)
 554 {
 555         size_t size;
 556         if (buf >= end) /* nowhere to put anything */
 557                 return;
 558         size = end - buf;
 559         if (size <= spaces) {
 560                 memset(buf, ' ', size);
 561                 return;
 562         }
 563         if (len) {
 564                 if (len > size - spaces)
 565                         len = size - spaces;
 566                 memmove(buf + spaces, buf, len);
 567         }
 568         memset(buf, ' ', spaces);
 569 }
 570
 571 /*
 572  * Handle field width padding for a string.
 573  * @buf: current buffer position
 574  * @n: length of string
 575  * @end: end of output buffer
 576  * @spec: for field width and flags
 577  * Returns: new buffer position after padding.
 578  */
 579 static noinline_for_stack
 580 char *widen_string(char *buf, int n, char *end, struct printf_spec spec)
 581 {
 582         unsigned spaces;
 583
 584         if (likely(n >= spec.field_width))
 585                 return buf;
 586         /* we want to pad the sucker */
 587         spaces = spec.field_width - n;
 588         if (!(spec.flags & LEFT)) {
 589                 move_right(buf - n, end, n, spaces);
 590                 return buf + spaces;
 591         }
 592         while (spaces--) {
 593                 if (buf < end)
 594                         *buf = ' ';
 595                 ++buf;
 596         }
 597         return buf;
 598 }
 599
 600 /* Handle string from a well known address. */
 601 static char *string_nocheck(char *buf, char *end, const char *s,
 602                             struct printf_spec spec)
 603 {
 604         int len = 0;
 605         int lim = spec.precision;
 606
 607         while (lim--) {
 608                 char c = *s++;
 609                 if (!c)
 610                         break;
 611                 if (buf < end)
 612                         *buf = c;
 613                 ++buf;
 614                 ++len;
 615         }
 616         return widen_string(buf, len, end, spec);
 617 }
 618
 619 static char *err_ptr(char *buf, char *end, void *ptr,
 620                      struct printf_spec spec)
 621 {
 622         int err = PTR_ERR(ptr);
 623         const char *sym = errname(err);
 624
 625         if (sym)
 626                 return string_nocheck(buf, end, sym, spec);
 627
 628         /*
 629          * Somebody passed ERR_PTR(-1234) or some other non-existing
 630          * Efoo - or perhaps CONFIG_SYMBOLIC_ERRNAME=n. Fall back to
 631          * printing it as its decimal representation.
 632          */
 633         spec.flags |= SIGN;
 634         spec.base = 10;
 635         return number(buf, end, err, spec);
 636 }
 637
 638 /* Be careful: error messages must fit into the given buffer. */
 639 static char *error_string(char *buf, char *end, const char *s,
 640                           struct printf_spec spec)
 641 {
 642         /*
 643          * Hard limit to avoid a completely insane messages. It actually
 644          * works pretty well because most error messages are in
 645          * the many pointer format modifiers.
 646          */
 647         if (spec.precision == -1)
 648                 spec.precision = 2 * sizeof(void *);
 649
 650         return string_nocheck(buf, end, s, spec);
 651 }
 652
 653 /*
 654  * Do not call any complex external code here. Nested printk()/vsprintf()
 655  * might cause infinite loops. Failures might break printk() and would
 656  * be hard to debug.
 657  */
 658 static const char *check_pointer_msg(const void *ptr)
 659 {
 660         if (!ptr)
 661                 return "(null)";
 662
 663         if ((unsigned long)ptr < PAGE_SIZE || IS_ERR_VALUE(ptr))
 664                 return "(efault)";
 665
 666         return NULL;
 667 }
 668
 669 static int check_pointer(char **buf, char *end, const void *ptr,
 670                          struct printf_spec spec)
 671 {
 672         const char *err_msg;
 673
 674         err_msg = check_pointer_msg(ptr);
 675         if (err_msg) {
 676                 *buf = error_string(*buf, end, err_msg, spec);
 677                 return -EFAULT;
 678         }
 679
 680         return 0;
 681 }
 682
 683 static noinline_for_stack
 684 char *string(char *buf, char *end, const char *s,
 685              struct printf_spec spec)
 686 {
 687         if (check_pointer(&buf, end, s, spec))
 688                 return buf;
 689
 690         return string_nocheck(buf, end, s, spec);
 691 }
 692
 693 static char *pointer_string(char *buf, char *end,
 694                             const void *ptr,
 695                             struct printf_spec spec)
 696 {
 697         spec.base = 16;
 698         spec.flags |= SMALL;
 699         if (spec.field_width == -1) {
 700                 spec.field_width = 2 * sizeof(ptr);
 701                 spec.flags |= ZEROPAD;
 702         }
 703
 704         return number(buf, end, (unsigned long int)ptr, spec);
 705 }
 706
 707 /* Make pointers available for printing early in the boot sequence. */
 708 static int debug_boot_weak_hash __ro_after_init;
 709
 710 static int __init debug_boot_weak_hash_enable(char *str)
 711 {
 712         debug_boot_weak_hash = 1;
 713         pr_info("debug_boot_weak_hash enabled\n");
 714         return 0;
 715 }
 716 early_param("debug_boot_weak_hash", debug_boot_weak_hash_enable);
 717
 718 static DEFINE_STATIC_KEY_TRUE(not_filled_random_ptr_key);
 719 static siphash_key_t ptr_key __read_mostly;
 720
 721 static void enable_ptr_key_workfn(struct work_struct *work)
 722 {
 723         get_random_bytes(&ptr_key, sizeof(ptr_key));
 724         /* Needs to run from preemptible context */
 725         static_branch_disable(&not_filled_random_ptr_key);
 726 }
 727
 728 static DECLARE_WORK(enable_ptr_key_work, enable_ptr_key_workfn);
 729
 730 static void fill_random_ptr_key(struct random_ready_callback *unused)
 731 {
 732         /* This may be in an interrupt handler. */
 733         queue_work(system_unbound_wq, &enable_ptr_key_work);
 734 }
 735
 736 static struct random_ready_callback random_ready = {
 737         .func = fill_random_ptr_key
 738 };
 739
 740 static int __init initialize_ptr_random(void)
 741 {
 742         int key_size = sizeof(ptr_key);
 743         int ret;
 744
 745         /* Use hw RNG if available. */
 746         if (get_random_bytes_arch(&ptr_key, key_size) == key_size) {
 747                 static_branch_disable(&not_filled_random_ptr_key);
 748                 return 0;
 749         }
 750
 751         ret = add_random_ready_callback(&random_ready);
 752         if (!ret) {
 753                 return 0;
 754         } else if (ret == -EALREADY) {
 755                 /* This is in preemptible context */
 756                 enable_ptr_key_workfn(&enable_ptr_key_work);
 757                 return 0;
 758         }
 759
 760         return ret;
 761 }
 762 early_initcall(initialize_ptr_random);
 763
 764 /* Maps a pointer to a 32 bit unique identifier. */
 765 static inline int __ptr_to_hashval(const void *ptr, unsigned long *hashval_out)
 766 {
 767         unsigned long hashval;
 768
 769         if (static_branch_unlikely(&not_filled_random_ptr_key))
 770                 return -EAGAIN;
 771
 772 #ifdef CONFIG_64BIT
 773         hashval = (unsigned long)siphash_1u64((u64)ptr, &ptr_key);
 774         /*
 775          * Mask off the first 32 bits, this makes explicit that we have
 776          * modified the address (and 32 bits is plenty for a unique ID).
 777          */
 778         hashval = hashval & 0xffffffff;
 779 #else
 780         hashval = (unsigned long)siphash_1u32((u32)ptr, &ptr_key);
 781 #endif
 782         *hashval_out = hashval;
 783         return 0;
 784 }
 785
 786 int ptr_to_hashval(const void *ptr, unsigned long *hashval_out)
 787 {
 788         return __ptr_to_hashval(ptr, hashval_out);
 789 }
 790
 791 static char *ptr_to_id(char *buf, char *end, const void *ptr,
 792                        struct printf_spec spec)
 793 {
 794         const char *str = sizeof(ptr) == 8 ? "(____ptrval____)" : "(ptrval)";
 795         unsigned long hashval;
 796         int ret;
 797
 798         /*
 799          * Print the real pointer value for NULL and error pointers,
 800          * as they are not actual addresses.
 801          */
 802         if (IS_ERR_OR_NULL(ptr))
 803                 return pointer_string(buf, end, ptr, spec);
 804
 805         /* When debugging early boot use non-cryptographically secure hash. */
 806         if (unlikely(debug_boot_weak_hash)) {
 807                 hashval = hash_long((unsigned long)ptr, 32);
 808                 return pointer_string(buf, end, (const void *)hashval, spec);
 809         }
 810
 811         ret = __ptr_to_hashval(ptr, &hashval);
 812         if (ret) {
 813                 spec.field_width = 2 * sizeof(ptr);
 814                 /* string length must be less than default_width */
 815                 return error_string(buf, end, str, spec);
 816         }
 817
 818         return pointer_string(buf, end, (const void *)hashval, spec);
 819 }
 820
 821 int kptr_restrict __read_mostly;
 822
 823 static noinline_for_stack
 824 char *restricted_pointer(char *buf, char *end, const void *ptr,
 825                          struct printf_spec spec)
 826 {
 827         switch (kptr_restrict) {
 828         case 0:
 829                 /* Handle as %p, hash and do _not_ leak addresses. */
 830                 return ptr_to_id(buf, end, ptr, spec);
 831         case 1: {
 832                 const struct cred *cred;
 833
 834                 /*
 835                  * kptr_restrict==1 cannot be used in IRQ context
 836                  * because its test for CAP_SYSLOG would be meaningless.
 837                  */
 838                 if (in_irq() || in_serving_softirq() || in_nmi()) {
 839                         if (spec.field_width == -1)
 840                                 spec.field_width = 2 * sizeof(ptr);
 841                         return error_string(buf, end, "pK-error", spec);
 842                 }
 843
 844                 /*
 845                  * Only print the real pointer value if the current
 846                  * process has CAP_SYSLOG and is running with the
 847                  * same credentials it started with. This is because
 848                  * access to files is checked at open() time, but %pK
 849                  * checks permission at read() time. We don't want to
 850                  * leak pointer values if a binary opens a file using
 851                  * %pK and then elevates privileges before reading it.
 852                  */
 853                 cred = current_cred();
 854                 if (!has_capability_noaudit(current, CAP_SYSLOG) ||
 855                     !uid_eq(cred->euid, cred->uid) ||
 856                     !gid_eq(cred->egid, cred->gid))
 857                         ptr = NULL;
 858                 break;
 859         }
 860         case 2:
 861         default:
 862                 /* Always print 0's for %pK */
 863                 ptr = NULL;
 864                 break;
 865         }
 866
 867         return pointer_string(buf, end, ptr, spec);
 868 }
 869
 870 static noinline_for_stack
 871 char *dentry_name(char *buf, char *end, const struct dentry *d, struct printf_spec spec,
 872                   const char *fmt)
 873 {
 874         const char *array[4], *s;
 875         const struct dentry *p;
 876         int depth;
 877         int i, n;
 878
 879         switch (fmt[1]) {
 880                 case '2': case '3': case '4':
 881                         depth = fmt[1] - '0';
 882                         break;
 883                 default:
 884                         depth = 1;
 885         }
 886
 887         rcu_read_lock();
 888         for (i = 0; i < depth; i++, d = p) {
 889                 if (check_pointer(&buf, end, d, spec)) {
 890                         rcu_read_unlock();
 891                         return buf;
 892                 }
 893
 894                 p = READ_ONCE(d->d_parent);
 895                 array[i] = READ_ONCE(d->d_name.name);
 896                 if (p == d) {
 897                         if (i)
 898                                 array[i] = "";
 899                         i++;
 900                         break;
 901                 }
 902         }
 903         s = array[--i];
 904         for (n = 0; n != spec.precision; n++, buf++) {
 905                 char c = *s++;
 906                 if (!c) {
 907                         if (!i)
 908                                 break;
 909                         c = '/';
 910                         s = array[--i];
 911                 }
 912                 if (buf < end)
 913                         *buf = c;
 914         }
 915         rcu_read_unlock();
 916         return widen_string(buf, n, end, spec);
 917 }
 918
 919 static noinline_for_stack
 920 char *file_dentry_name(char *buf, char *end, const struct file *f,
 921                         struct printf_spec spec, const char *fmt)
 922 {
 923         if (check_pointer(&buf, end, f, spec))
 924                 return buf;
 925
 926         return dentry_name(buf, end, f->f_path.dentry, spec, fmt);
 927 }
 928 #ifdef CONFIG_BLOCK
 929 static noinline_for_stack
 930 char *bdev_name(char *buf, char *end, struct block_device *bdev,
 931                 struct printf_spec spec, const char *fmt)
 932 {
 933         struct gendisk *hd;
 934
 935         if (check_pointer(&buf, end, bdev, spec))
 936                 return buf;
 937
 938         hd = bdev->bd_disk;
 939         buf = string(buf, end, hd->disk_name, spec);
 940         if (bdev->bd_part->partno) {
 941                 if (isdigit(hd->disk_name[strlen(hd->disk_name)-1])) {
 942                         if (buf < end)
 943                                 *buf = 'p';
 944                         buf++;
 945                 }
 946                 buf = number(buf, end, bdev->bd_part->partno, spec);
 947         }
 948         return buf;
 949 }
 950 #endif
 951
 952 static noinline_for_stack
 953 char *symbol_string(char *buf, char *end, void *ptr,
 954                     struct printf_spec spec, const char *fmt)
 955 {
 956         unsigned long value;
 957 #ifdef CONFIG_KALLSYMS
 958         char sym[KSYM_SYMBOL_LEN];
 959 #endif
 960
 961         if (fmt[1] == 'R')
 962                 ptr = __builtin_extract_return_addr(ptr);
 963         value = (unsigned long)ptr;
 964
 965 #ifdef CONFIG_KALLSYMS
 966         if (*fmt == 'B')
 967                 sprint_backtrace(sym, value);
 968         else if (*fmt != 's')
 969                 sprint_symbol(sym, value);
 970         else
 971                 sprint_symbol_no_offset(sym, value);
 972
 973         return string_nocheck(buf, end, sym, spec);
 974 #else
 975         return special_hex_number(buf, end, value, sizeof(void *));
 976 #endif
 977 }
 978
 979 static const struct printf_spec default_str_spec = {
 980         .field_width = -1,
 981         .precision = -1,
 982 };
 983
 984 static const struct printf_spec default_flag_spec = {
 985         .base = 16,
 986         .precision = -1,
 987         .flags = SPECIAL | SMALL,
 988 };
 989
 990 static const struct printf_spec default_dec_spec = {
 991         .base = 10,
 992         .precision = -1,
 993 };
 994
 995 static const struct printf_spec default_dec02_spec = {
 996         .base = 10,
 997         .field_width = 2,
 998         .precision = -1,
 999         .flags = ZEROPAD,
1000 };
1001
1002 static const struct printf_spec default_dec04_spec = {
1003         .base = 10,
1004         .field_width = 4,
1005         .precision = -1,
1006         .flags = ZEROPAD,
1007 };
1008
1009 static noinline_for_stack
1010 char *resource_string(char *buf, char *end, struct resource *res,
1011                       struct printf_spec spec, const char *fmt)
1012 {
1013 #ifndef IO_RSRC_PRINTK_SIZE
1014 #define IO_RSRC_PRINTK_SIZE     6
1015 #endif
1016
1017 #ifndef MEM_RSRC_PRINTK_SIZE
1018 #define MEM_RSRC_PRINTK_SIZE    10
1019 #endif
1020         static const struct printf_spec io_spec = {
1021                 .base = 16,
1022                 .field_width = IO_RSRC_PRINTK_SIZE,
1023                 .precision = -1,
1024                 .flags = SPECIAL | SMALL | ZEROPAD,
1025         };
1026         static const struct printf_spec mem_spec = {
1027                 .base = 16,
1028                 .field_width = MEM_RSRC_PRINTK_SIZE,
1029                 .precision = -1,
1030                 .flags = SPECIAL | SMALL | ZEROPAD,
1031         };
1032         static const struct printf_spec bus_spec = {
1033                 .base = 16,
1034                 .field_width = 2,
1035                 .precision = -1,
1036                 .flags = SMALL | ZEROPAD,
1037         };
1038         static const struct printf_spec str_spec = {
1039                 .field_width = -1,
1040                 .precision = 10,
1041                 .flags = LEFT,
1042         };
1043
1044         /* 32-bit res (sizeof==4): 10 chars in dec, 10 in hex ("0x" + 8)
1045          * 64-bit res (sizeof==8): 20 chars in dec, 18 in hex ("0x" + 16) */
1046 #define RSRC_BUF_SIZE           ((2 * sizeof(resource_size_t)) + 4)
1047 #define FLAG_BUF_SIZE           (2 * sizeof(res->flags))
1048 #define DECODED_BUF_SIZE        sizeof("[mem - 64bit pref window disabled]")
1049 #define RAW_BUF_SIZE            sizeof("[mem - flags 0x]")
1050         char sym[max(2*RSRC_BUF_SIZE + DECODED_BUF_SIZE,
1051                      2*RSRC_BUF_SIZE + FLAG_BUF_SIZE + RAW_BUF_SIZE)];
1052
1053         char *p = sym, *pend = sym + sizeof(sym);
1054         int decode = (fmt[0] == 'R') ? 1 : 0;
1055         const struct printf_spec *specp;
1056
1057         if (check_pointer(&buf, end, res, spec))
1058                 return buf;
1059
1060         *p++ = '[';
1061         if (res->flags & IORESOURCE_IO) {
1062                 p = string_nocheck(p, pend, "io  ", str_spec);
1063                 specp = &io_spec;
1064         } else if (res->flags & IORESOURCE_MEM) {
1065                 p = string_nocheck(p, pend, "mem ", str_spec);
1066                 specp = &mem_spec;
1067         } else if (res->flags & IORESOURCE_IRQ) {
1068                 p = string_nocheck(p, pend, "irq ", str_spec);
1069                 specp = &default_dec_spec;
1070         } else if (res->flags & IORESOURCE_DMA) {
1071                 p = string_nocheck(p, pend, "dma ", str_spec);
1072                 specp = &default_dec_spec;
1073         } else if (res->flags & IORESOURCE_BUS) {
1074                 p = string_nocheck(p, pend, "bus ", str_spec);
1075                 specp = &bus_spec;
1076         } else {
1077                 p = string_nocheck(p, pend, "??? ", str_spec);
1078                 specp = &mem_spec;
1079                 decode = 0;
1080         }
1081         if (decode && res->flags & IORESOURCE_UNSET) {
1082                 p = string_nocheck(p, pend, "size ", str_spec);
1083                 p = number(p, pend, resource_size(res), *specp);
1084         } else {
1085                 p = number(p, pend, res->start, *specp);
1086                 if (res->start != res->end) {
1087                         *p++ = '-';
1088                         p = number(p, pend, res->end, *specp);
1089                 }
1090         }
1091         if (decode) {
1092                 if (res->flags & IORESOURCE_MEM_64)
1093                         p = string_nocheck(p, pend, " 64bit", str_spec);
1094                 if (res->flags & IORESOURCE_PREFETCH)
1095                         p = string_nocheck(p, pend, " pref", str_spec);
1096                 if (res->flags & IORESOURCE_WINDOW)
1097                         p = string_nocheck(p, pend, " window", str_spec);
1098                 if (res->flags & IORESOURCE_DISABLED)
1099                         p = string_nocheck(p, pend, " disabled", str_spec);
1100         } else {
1101                 p = string_nocheck(p, pend, " flags ", str_spec);
1102                 p = number(p, pend, res->flags, default_flag_spec);
1103         }
1104         *p++ = ']';
1105         *p = '\0';
1106
1107         return string_nocheck(buf, end, sym, spec);
1108 }
1109
1110 static noinline_for_stack
1111 char *hex_string(char *buf, char *end, u8 *addr, struct printf_spec spec,
1112                  const char *fmt)
1113 {
1114         int i, len = 1;         /* if we pass '%ph[CDN]', field width remains
1115                                    negative value, fallback to the default */
1116         char separator;
1117
1118         if (spec.field_width == 0)
1119                 /* nothing to print */
1120                 return buf;
1121
1122         if (check_pointer(&buf, end, addr, spec))
1123                 return buf;
1124
1125         switch (fmt[1]) {
1126         case 'C':
1127                 separator = ':';
1128                 break;
1129         case 'D':
1130                 separator = '-';
1131                 break;
1132         case 'N':
1133                 separator = 0;
1134                 break;
1135         default:
1136                 separator = ' ';
1137                 break;
1138         }
1139
1140         if (spec.field_width > 0)
1141                 len = min_t(int, spec.field_width, 64);
1142
1143         for (i = 0; i < len; ++i) {
1144                 if (buf < end)
1145                         *buf = hex_asc_hi(addr[i]);
1146                 ++buf;
1147                 if (buf < end)
1148                         *buf = hex_asc_lo(addr[i]);
1149                 ++buf;
1150
1151                 if (separator && i != len - 1) {
1152                         if (buf < end)
1153                                 *buf = separator;
1154                         ++buf;
1155                 }
1156         }
1157
1158         return buf;
1159 }
1160
1161 static noinline_for_stack
1162 char *bitmap_string(char *buf, char *end, unsigned long *bitmap,
1163                     struct printf_spec spec, const char *fmt)
1164 {
1165         const int CHUNKSZ = 32;
1166         int nr_bits = max_t(int, spec.field_width, 0);
1167         int i, chunksz;
1168         bool first = true;
1169
1170         if (check_pointer(&buf, end, bitmap, spec))
1171                 return buf;
1172
1173         /* reused to print numbers */
1174         spec = (struct printf_spec){ .flags = SMALL | ZEROPAD, .base = 16 };
1175
1176         chunksz = nr_bits & (CHUNKSZ - 1);
1177         if (chunksz == 0)
1178                 chunksz = CHUNKSZ;
1179
1180         i = ALIGN(nr_bits, CHUNKSZ) - CHUNKSZ;
1181         for (; i >= 0; i -= CHUNKSZ) {
1182                 u32 chunkmask, val;
1183                 int word, bit;
1184
1185                 chunkmask = ((1ULL << chunksz) - 1);
1186                 word = i / BITS_PER_LONG;
1187                 bit = i % BITS_PER_LONG;
1188                 val = (bitmap[word] >> bit) & chunkmask;
1189
1190                 if (!first) {
1191                         if (buf < end)
1192                                 *buf = ',';
1193                         buf++;
1194                 }
1195                 first = false;
1196
1197                 spec.field_width = DIV_ROUND_UP(chunksz, 4);
1198                 buf = number(buf, end, val, spec);
1199
1200                 chunksz = CHUNKSZ;
1201         }
1202         return buf;
1203 }
1204
1205 static noinline_for_stack
1206 char *bitmap_list_string(char *buf, char *end, unsigned long *bitmap,
1207                          struct printf_spec spec, const char *fmt)
1208 {
1209         int nr_bits = max_t(int, spec.field_width, 0);
1210         /* current bit is 'cur', most recently seen range is [rbot, rtop] */
1211         int cur, rbot, rtop;
1212         bool first = true;
1213
1214         if (check_pointer(&buf, end, bitmap, spec))
1215                 return buf;
1216
1217         rbot = cur = find_first_bit(bitmap, nr_bits);
1218         while (cur < nr_bits) {
1219                 rtop = cur;
1220                 cur = find_next_bit(bitmap, nr_bits, cur + 1);
1221                 if (cur < nr_bits && cur <= rtop + 1)
1222                         continue;
1223
1224                 if (!first) {
1225                         if (buf < end)
1226                                 *buf = ',';
1227                         buf++;
1228                 }
1229                 first = false;
1230
1231                 buf = number(buf, end, rbot, default_dec_spec);
1232                 if (rbot < rtop) {
1233                         if (buf < end)
1234                                 *buf = '-';
1235                         buf++;
1236
1237                         buf = number(buf, end, rtop, default_dec_spec);
1238                 }
1239
1240                 rbot = cur;
1241         }
1242         return buf;
1243 }
1244
1245 static noinline_for_stack
1246 char *mac_address_string(char *buf, char *end, u8 *addr,
1247                          struct printf_spec spec, const char *fmt)
1248 {
1249         char mac_addr[sizeof("xx:xx:xx:xx:xx:xx")];
1250         char *p = mac_addr;
1251         int i;
1252         char separator;
1253         bool reversed = false;
1254
1255         if (check_pointer(&buf, end, addr, spec))
1256                 return buf;
1257
1258         switch (fmt[1]) {
1259         case 'F':
1260                 separator = '-';
1261                 break;
1262
1263         case 'R':
1264                 reversed = true;
1265                 /* fall through */
1266
1267         default:
1268                 separator = ':';
1269                 break;
1270         }
1271
1272         for (i = 0; i < 6; i++) {
1273                 if (reversed)
1274                         p = hex_byte_pack(p, addr[5 - i]);
1275                 else
1276                         p = hex_byte_pack(p, addr[i]);
1277
1278                 if (fmt[0] == 'M' && i != 5)
1279                         *p++ = separator;
1280         }
1281         *p = '\0';
1282
1283         return string_nocheck(buf, end, mac_addr, spec);
1284 }
1285
1286 static noinline_for_stack
1287 char *ip4_string(char *p, const u8 *addr, const char *fmt)
1288 {
1289         int i;
1290         bool leading_zeros = (fmt[0] == 'i');
1291         int index;
1292         int step;
1293
1294         switch (fmt[2]) {
1295         case 'h':
1296 #ifdef __BIG_ENDIAN
1297                 index = 0;
1298                 step = 1;
1299 #else
1300                 index = 3;
1301                 step = -1;
1302 #endif
1303                 break;
1304         case 'l':
1305                 index = 3;
1306                 step = -1;
1307                 break;
1308         case 'n':
1309         case 'b':
1310         default:
1311                 index = 0;
1312                 step = 1;
1313                 break;
1314         }
1315         for (i = 0; i < 4; i++) {
1316                 char temp[4] __aligned(2);      /* hold each IP quad in reverse order */
1317                 int digits = put_dec_trunc8(temp, addr[index]) - temp;
1318                 if (leading_zeros) {
1319                         if (digits < 3)
1320                                 *p++ = '0';
1321                         if (digits < 2)
1322                                 *p++ = '0';
1323                 }
1324                 /* reverse the digits in the quad */
1325                 while (digits--)
1326                         *p++ = temp[digits];
1327                 if (i < 3)
1328                         *p++ = '.';
1329                 index += step;
1330         }
1331         *p = '\0';
1332
1333         return p;
1334 }
1335
1336 static noinline_for_stack
1337 char *ip6_compressed_string(char *p, const char *addr)
1338 {
1339         int i, j, range;
1340         unsigned char zerolength[8];
1341         int longest = 1;
1342         int colonpos = -1;
1343         u16 word;
1344         u8 hi, lo;
1345         bool needcolon = false;
1346         bool useIPv4;
1347         struct in6_addr in6;
1348
1349         memcpy(&in6, addr, sizeof(struct in6_addr));
1350
1351         useIPv4 = ipv6_addr_v4mapped(&in6) || ipv6_addr_is_isatap(&in6);
1352
1353         memset(zerolength, 0, sizeof(zerolength));
1354
1355         if (useIPv4)
1356                 range = 6;
1357         else
1358                 range = 8;
1359
1360         /* find position of longest 0 run */
1361         for (i = 0; i < range; i++) {
1362                 for (j = i; j < range; j++) {
1363                         if (in6.s6_addr16[j] != 0)
1364                                 break;
1365                         zerolength[i]++;
1366                 }
1367         }
1368         for (i = 0; i < range; i++) {
1369                 if (zerolength[i] > longest) {
1370                         longest = zerolength[i];
1371                         colonpos = i;
1372                 }
1373         }
1374         if (longest == 1)               /* don't compress a single 0 */
1375                 colonpos = -1;
1376
1377         /* emit address */
1378         for (i = 0; i < range; i++) {
1379                 if (i == colonpos) {
1380                         if (needcolon || i == 0)
1381                                 *p++ = ':';
1382                         *p++ = ':';
1383                         needcolon = false;
1384                         i += longest - 1;
1385                         continue;
1386                 }
1387                 if (needcolon) {
1388                         *p++ = ':';
1389                         needcolon = false;
1390                 }
1391                 /* hex u16 without leading 0s */
1392                 word = ntohs(in6.s6_addr16[i]);
1393                 hi = word >> 8;
1394                 lo = word & 0xff;
1395                 if (hi) {
1396                         if (hi > 0x0f)
1397                                 p = hex_byte_pack(p, hi);
1398                         else
1399                                 *p++ = hex_asc_lo(hi);
1400                         p = hex_byte_pack(p, lo);
1401                 }
1402                 else if (lo > 0x0f)
1403                         p = hex_byte_pack(p, lo);
1404                 else
1405                         *p++ = hex_asc_lo(lo);
1406                 needcolon = true;
1407         }
1408
1409         if (useIPv4) {
1410                 if (needcolon)
1411                         *p++ = ':';
1412                 p = ip4_string(p, &in6.s6_addr[12], "I4");
1413         }
1414         *p = '\0';
1415
1416         return p;
1417 }
1418
1419 static noinline_for_stack
1420 char *ip6_string(char *p, const char *addr, const char *fmt)
1421 {
1422         int i;
1423
1424         for (i = 0; i < 8; i++) {
1425                 p = hex_byte_pack(p, *addr++);
1426                 p = hex_byte_pack(p, *addr++);
1427                 if (fmt[0] == 'I' && i != 7)
1428                         *p++ = ':';
1429         }
1430         *p = '\0';
1431
1432         return p;
1433 }
1434
1435 static noinline_for_stack
1436 char *ip6_addr_string(char *buf, char *end, const u8 *addr,
1437                       struct printf_spec spec, const char *fmt)
1438 {
1439         char ip6_addr[sizeof("xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255")];
1440
1441         if (fmt[0] == 'I' && fmt[2] == 'c')
1442                 ip6_compressed_string(ip6_addr, addr);
1443         else
1444                 ip6_string(ip6_addr, addr, fmt);
1445
1446         return string_nocheck(buf, end, ip6_addr, spec);
1447 }
1448
1449 static noinline_for_stack
1450 char *ip4_addr_string(char *buf, char *end, const u8 *addr,
1451                       struct printf_spec spec, const char *fmt)
1452 {
1453         char ip4_addr[sizeof("255.255.255.255")];
1454
1455         ip4_string(ip4_addr, addr, fmt);
1456
1457         return string_nocheck(buf, end, ip4_addr, spec);
1458 }
1459
1460 static noinline_for_stack
1461 char *ip6_addr_string_sa(char *buf, char *end, const struct sockaddr_in6 *sa,
1462                          struct printf_spec spec, const char *fmt)
1463 {
1464         bool have_p = false, have_s = false, have_f = false, have_c = false;
1465         char ip6_addr[sizeof("[xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255]") +
1466                       sizeof(":12345") + sizeof("/123456789") +
1467                       sizeof("%1234567890")];
1468         char *p = ip6_addr, *pend = ip6_addr + sizeof(ip6_addr);
1469         const u8 *addr = (const u8 *) &sa->sin6_addr;
1470         char fmt6[2] = { fmt[0], '6' };
1471         u8 off = 0;
1472
1473         fmt++;
1474         while (isalpha(*++fmt)) {
1475                 switch (*fmt) {
1476                 case 'p':
1477                         have_p = true;
1478                         break;
1479                 case 'f':
1480                         have_f = true;
1481                         break;
1482                 case 's':
1483                         have_s = true;
1484                         break;
1485                 case 'c':
1486                         have_c = true;
1487                         break;
1488                 }
1489         }
1490
1491         if (have_p || have_s || have_f) {
1492                 *p = '[';
1493                 off = 1;
1494         }
1495
1496         if (fmt6[0] == 'I' && have_c)
1497                 p = ip6_compressed_string(ip6_addr + off, addr);
1498         else
1499                 p = ip6_string(ip6_addr + off, addr, fmt6);
1500
1501         if (have_p || have_s || have_f)
1502                 *p++ = ']';
1503
1504         if (have_p) {
1505                 *p++ = ':';
1506                 p = number(p, pend, ntohs(sa->sin6_port), spec);
1507         }
1508         if (have_f) {
1509                 *p++ = '/';
1510                 p = number(p, pend, ntohl(sa->sin6_flowinfo &
1511                                           IPV6_FLOWINFO_MASK), spec);
1512         }
1513         if (have_s) {
1514                 *p++ = '%';
1515                 p = number(p, pend, sa->sin6_scope_id, spec);
1516         }
1517         *p = '\0';
1518
1519         return string_nocheck(buf, end, ip6_addr, spec);
1520 }
1521
1522 static noinline_for_stack
1523 char *ip4_addr_string_sa(char *buf, char *end, const struct sockaddr_in *sa,
1524                          struct printf_spec spec, const char *fmt)
1525 {
1526         bool have_p = false;
1527         char *p, ip4_addr[sizeof("255.255.255.255") + sizeof(":12345")];
1528         char *pend = ip4_addr + sizeof(ip4_addr);
1529         const u8 *addr = (const u8 *) &sa->sin_addr.s_addr;
1530         char fmt4[3] = { fmt[0], '4', 0 };
1531
1532         fmt++;
1533         while (isalpha(*++fmt)) {
1534                 switch (*fmt) {
1535                 case 'p':
1536                         have_p = true;
1537                         break;
1538                 case 'h':
1539                 case 'l':
1540                 case 'n':
1541                 case 'b':
1542                         fmt4[2] = *fmt;
1543                         break;
1544                 }
1545         }
1546
1547         p = ip4_string(ip4_addr, addr, fmt4);
1548         if (have_p) {
1549                 *p++ = ':';
1550                 p = number(p, pend, ntohs(sa->sin_port), spec);
1551         }
1552         *p = '\0';
1553
1554         return string_nocheck(buf, end, ip4_addr, spec);
1555 }
1556
1557 static noinline_for_stack
1558 char *ip_addr_string(char *buf, char *end, const void *ptr,
1559                      struct printf_spec spec, const char *fmt)
1560 {
1561         char *err_fmt_msg;
1562
1563         if (check_pointer(&buf, end, ptr, spec))
1564                 return buf;
1565
1566         switch (fmt[1]) {
1567         case '6':
1568                 return ip6_addr_string(buf, end, ptr, spec, fmt);
1569         case '4':
1570                 return ip4_addr_string(buf, end, ptr, spec, fmt);
1571         case 'S': {
1572                 const union {
1573                         struct sockaddr         raw;
1574                         struct sockaddr_in      v4;
1575                         struct sockaddr_in6     v6;
1576                 } *sa = ptr;
1577
1578                 switch (sa->raw.sa_family) {
1579                 case AF_INET:
1580                         return ip4_addr_string_sa(buf, end, &sa->v4, spec, fmt);
1581                 case AF_INET6:
1582                         return ip6_addr_string_sa(buf, end, &sa->v6, spec, fmt);
1583                 default:
1584                         return error_string(buf, end, "(einval)", spec);
1585                 }}
1586         }
1587
1588         err_fmt_msg = fmt[0] == 'i' ? "(%pi?)" : "(%pI?)";
1589         return error_string(buf, end, err_fmt_msg, spec);
1590 }
1591
1592 static noinline_for_stack
1593 char *escaped_string(char *buf, char *end, u8 *addr, struct printf_spec spec,
1594                      const char *fmt)
1595 {
1596         bool found = true;
1597         int count = 1;
1598         unsigned int flags = 0;
1599         int len;
1600
1601         if (spec.field_width == 0)
1602                 return buf;                             /* nothing to print */
1603
1604         if (check_pointer(&buf, end, addr, spec))
1605                 return buf;
1606
1607         do {
1608                 switch (fmt[count++]) {
1609                 case 'a':
1610                         flags |= ESCAPE_ANY;
1611                         break;
1612                 case 'c':
1613                         flags |= ESCAPE_SPECIAL;
1614                         break;
1615                 case 'h':
1616                         flags |= ESCAPE_HEX;
1617                         break;
1618                 case 'n':
1619                         flags |= ESCAPE_NULL;
1620                         break;
1621                 case 'o':
1622                         flags |= ESCAPE_OCTAL;
1623                         break;
1624                 case 'p':
1625                         flags |= ESCAPE_NP;
1626                         break;
1627                 case 's':
1628                         flags |= ESCAPE_SPACE;
1629                         break;
1630                 default:
1631                         found = false;
1632                         break;
1633                 }
1634         } while (found);
1635
1636         if (!flags)
1637                 flags = ESCAPE_ANY_NP;
1638
1639         len = spec.field_width < 0 ? 1 : spec.field_width;
1640
1641         /*
1642          * string_escape_mem() writes as many characters as it can to
1643          * the given buffer, and returns the total size of the output
1644          * had the buffer been big enough.
1645          */
1646         buf += string_escape_mem(addr, len, buf, buf < end ? end - buf : 0, flags, NULL);
1647
1648         return buf;
1649 }
1650
1651 static char *va_format(char *buf, char *end, struct va_format *va_fmt,
1652                        struct printf_spec spec, const char *fmt)
1653 {
1654         va_list va;
1655
1656         if (check_pointer(&buf, end, va_fmt, spec))
1657                 return buf;
1658
1659         va_copy(va, *va_fmt->va);
1660         buf += vsnprintf(buf, end > buf ? end - buf : 0, va_fmt->fmt, va);
1661         va_end(va);
1662
1663         return buf;
1664 }
1665
1666 static noinline_for_stack
1667 char *uuid_string(char *buf, char *end, const u8 *addr,
1668                   struct printf_spec spec, const char *fmt)
1669 {
1670         char uuid[UUID_STRING_LEN + 1];
1671         char *p = uuid;
1672         int i;
1673         const u8 *index = uuid_index;
1674         bool uc = false;
1675
1676         if (check_pointer(&buf, end, addr, spec))
1677                 return buf;
1678
1679         switch (*(++fmt)) {
1680         case 'L':
1681                 uc = true;              /* fall-through */
1682         case 'l':
1683                 index = guid_index;
1684                 break;
1685         case 'B':
1686                 uc = true;
1687                 break;
1688         }
1689
1690         for (i = 0; i < 16; i++) {
1691                 if (uc)
1692                         p = hex_byte_pack_upper(p, addr[index[i]]);
1693                 else
1694                         p = hex_byte_pack(p, addr[index[i]]);
1695                 switch (i) {
1696                 case 3:
1697                 case 5:
1698                 case 7:
1699                 case 9:
1700                         *p++ = '-';
1701                         break;
1702                 }
1703         }
1704
1705         *p = 0;
1706
1707         return string_nocheck(buf, end, uuid, spec);
1708 }
1709
1710 static noinline_for_stack
1711 char *netdev_bits(char *buf, char *end, const void *addr,
1712                   struct printf_spec spec,  const char *fmt)
1713 {
1714         unsigned long long num;
1715         int size;
1716
1717         if (check_pointer(&buf, end, addr, spec))
1718                 return buf;
1719
1720         switch (fmt[1]) {
1721         case 'F':
1722                 num = *(const netdev_features_t *)addr;
1723                 size = sizeof(netdev_features_t);
1724                 break;
1725         default:
1726                 return error_string(buf, end, "(%pN?)", spec);
1727         }
1728
1729         return special_hex_number(buf, end, num, size);
1730 }
1731
1732 static noinline_for_stack
1733 char *address_val(char *buf, char *end, const void *addr,
1734                   struct printf_spec spec, const char *fmt)
1735 {
1736         unsigned long long num;
1737         int size;
1738
1739         if (check_pointer(&buf, end, addr, spec))
1740                 return buf;
1741
1742         switch (fmt[1]) {
1743         case 'd':
1744                 num = *(const dma_addr_t *)addr;
1745                 size = sizeof(dma_addr_t);
1746                 break;
1747         case 'p':
1748         default:
1749                 num = *(const phys_addr_t *)addr;
1750                 size = sizeof(phys_addr_t);
1751                 break;
1752         }
1753
1754         return special_hex_number(buf, end, num, size);
1755 }
1756
1757 static noinline_for_stack
1758 char *date_str(char *buf, char *end, const struct rtc_time *tm, bool r)
1759 {
1760         int year = tm->tm_year + (r ? 0 : 1900);
1761         int mon = tm->tm_mon + (r ? 0 : 1);
1762
1763         buf = number(buf, end, year, default_dec04_spec);
1764         if (buf < end)
1765                 *buf = '-';
1766         buf++;
1767
1768         buf = number(buf, end, mon, default_dec02_spec);
1769         if (buf < end)
1770                 *buf = '-';
1771         buf++;
1772
1773         return number(buf, end, tm->tm_mday, default_dec02_spec);
1774 }
1775
1776 static noinline_for_stack
1777 char *time_str(char *buf, char *end, const struct rtc_time *tm, bool r)
1778 {
1779         buf = number(buf, end, tm->tm_hour, default_dec02_spec);
1780         if (buf < end)
1781                 *buf = ':';
1782         buf++;
1783
1784         buf = number(buf, end, tm->tm_min, default_dec02_spec);
1785         if (buf < end)
1786                 *buf = ':';
1787         buf++;
1788
1789         return number(buf, end, tm->tm_sec, default_dec02_spec);
1790 }
1791
1792 static noinline_for_stack
1793 char *rtc_str(char *buf, char *end, const struct rtc_time *tm,
1794               struct printf_spec spec, const char *fmt)
1795 {
1796         bool have_t = true, have_d = true;
1797         bool raw = false;
1798         int count = 2;
1799
1800         if (check_pointer(&buf, end, tm, spec))
1801                 return buf;
1802
1803         switch (fmt[count]) {
1804         case 'd':
1805                 have_t = false;
1806                 count++;
1807                 break;
1808         case 't':
1809                 have_d = false;
1810                 count++;
1811                 break;
1812         }
1813
1814         raw = fmt[count] == 'r';
1815
1816         if (have_d)
1817                 buf = date_str(buf, end, tm, raw);
1818         if (have_d && have_t) {
1819                 /* Respect ISO 8601 */
1820                 if (buf < end)
1821                         *buf = 'T';
1822                 buf++;
1823         }
1824         if (have_t)
1825                 buf = time_str(buf, end, tm, raw);
1826
1827         return buf;
1828 }
1829
1830 static noinline_for_stack
1831 char *time64_str(char *buf, char *end, const time64_t time,
1832                  struct printf_spec spec, const char *fmt)
1833 {
1834         struct rtc_time rtc_time;
1835         struct tm tm;
1836
1837         time64_to_tm(time, 0, &tm);
1838
1839         rtc_time.tm_sec = tm.tm_sec;
1840         rtc_time.tm_min = tm.tm_min;
1841         rtc_time.tm_hour = tm.tm_hour;
1842         rtc_time.tm_mday = tm.tm_mday;
1843         rtc_time.tm_mon = tm.tm_mon;
1844         rtc_time.tm_year = tm.tm_year;
1845         rtc_time.tm_wday = tm.tm_wday;
1846         rtc_time.tm_yday = tm.tm_yday;
1847
1848         rtc_time.tm_isdst = 0;
1849
1850         return rtc_str(buf, end, &rtc_time, spec, fmt);
1851 }
1852
1853 static noinline_for_stack
1854 char *time_and_date(char *buf, char *end, void *ptr, struct printf_spec spec,
1855                     const char *fmt)
1856 {
1857         switch (fmt[1]) {
1858         case 'R':
1859                 return rtc_str(buf, end, (const struct rtc_time *)ptr, spec, fmt);
1860         case 'T':
1861                 return time64_str(buf, end, *(const time64_t *)ptr, spec, fmt);
1862         default:
1863                 return error_string(buf, end, "(%pt?)", spec);
1864         }
1865 }
1866
1867 static noinline_for_stack
1868 char *clock(char *buf, char *end, struct clk *clk, struct printf_spec spec,
1869             const char *fmt)
1870 {
1871         if (!IS_ENABLED(CONFIG_HAVE_CLK))
1872                 return error_string(buf, end, "(%pC?)", spec);
1873
1874         if (check_pointer(&buf, end, clk, spec))
1875                 return buf;
1876
1877         switch (fmt[1]) {
1878         case 'n':
1879         default:
1880 #ifdef CONFIG_COMMON_CLK
1881                 return string(buf, end, __clk_get_name(clk), spec);
1882 #else
1883                 return ptr_to_id(buf, end, clk, spec);
1884 #endif
1885         }
1886 }
1887
1888 static
1889 char *format_flags(char *buf, char *end, unsigned long flags,
1890                                         const struct trace_print_flags *names)
1891 {
1892         unsigned long mask;
1893
1894         for ( ; flags && names->name; names++) {
1895                 mask = names->mask;
1896                 if ((flags & mask) != mask)
1897                         continue;
1898
1899                 buf = string(buf, end, names->name, default_str_spec);
1900
1901                 flags &= ~mask;
1902                 if (flags) {
1903                         if (buf < end)
1904                                 *buf = '|';
1905                         buf++;
1906                 }
1907         }
1908
1909         if (flags)
1910                 buf = number(buf, end, flags, default_flag_spec);
1911
1912         return buf;
1913 }
1914
1915 static noinline_for_stack
1916 char *flags_string(char *buf, char *end, void *flags_ptr,
1917                    struct printf_spec spec, const char *fmt)
1918 {
1919         unsigned long flags;
1920         const struct trace_print_flags *names;
1921
1922         if (check_pointer(&buf, end, flags_ptr, spec))
1923                 return buf;
1924
1925         switch (fmt[1]) {
1926         case 'p':
1927                 flags = *(unsigned long *)flags_ptr;
1928                 /* Remove zone id */
1929                 flags &= (1UL << NR_PAGEFLAGS) - 1;
1930                 names = pageflag_names;
1931                 break;
1932         case 'v':
1933                 flags = *(unsigned long *)flags_ptr;
1934                 names = vmaflag_names;
1935                 break;
1936         case 'g':
1937                 flags = *(gfp_t *)flags_ptr;
1938                 names = gfpflag_names;
1939                 break;
1940         default:
1941                 return error_string(buf, end, "(%pG?)", spec);
1942         }
1943
1944         return format_flags(buf, end, flags, names);
1945 }
1946
1947 static noinline_for_stack
1948 char *fwnode_full_name_string(struct fwnode_handle *fwnode, char *buf,
1949                               char *end)
1950 {
1951         int depth;
1952
1953         /* Loop starting from the root node to the current node. */
1954         for (depth = fwnode_count_parents(fwnode); depth >= 0; depth--) {
1955                 struct fwnode_handle *__fwnode =
1956                         fwnode_get_nth_parent(fwnode, depth);
1957
1958                 buf = string(buf, end, fwnode_get_name_prefix(__fwnode),
1959                              default_str_spec);
1960                 buf = string(buf, end, fwnode_get_name(__fwnode),
1961                              default_str_spec);
1962
1963                 fwnode_handle_put(__fwnode);
1964         }
1965
1966         return buf;
1967 }
1968
1969 static noinline_for_stack
1970 char *device_node_string(char *buf, char *end, struct device_node *dn,
1971                          struct printf_spec spec, const char *fmt)
1972 {
1973         char tbuf[sizeof("xxxx") + 1];
1974         const char *p;
1975         int ret;
1976         char *buf_start = buf;
1977         struct property *prop;
1978         bool has_mult, pass;
1979         static const struct printf_spec num_spec = {
1980                 .flags = SMALL,
1981                 .field_width = -1,
1982                 .precision = -1,
1983                 .base = 10,
1984         };
1985
1986         struct printf_spec str_spec = spec;
1987         str_spec.field_width = -1;
1988
1989         if (fmt[0] != 'F')
1990                 return error_string(buf, end, "(%pO?)", spec);
1991
1992         if (!IS_ENABLED(CONFIG_OF))
1993                 return error_string(buf, end, "(%pOF?)", spec);
1994
1995         if (check_pointer(&buf, end, dn, spec))
1996                 return buf;
1997
1998         /* simple case without anything any more format specifiers */
1999         fmt++;
2000         if (fmt[0] == '\0' || strcspn(fmt,"fnpPFcC") > 0)
2001                 fmt = "f";
2002
2003         for (pass = false; strspn(fmt,"fnpPFcC"); fmt++, pass = true) {
2004                 int precision;
2005                 if (pass) {
2006                         if (buf < end)
2007                                 *buf = ':';
2008                         buf++;
2009                 }
2010
2011                 switch (*fmt) {
2012                 case 'f':       /* full_name */
2013                         buf = fwnode_full_name_string(of_fwnode_handle(dn), buf,
2014                                                       end);
2015                         break;
2016                 case 'n':       /* name */
2017                         p = fwnode_get_name(of_fwnode_handle(dn));
2018                         precision = str_spec.precision;
2019                         str_spec.precision = strchrnul(p, '@') - p;
2020                         buf = string(buf, end, p, str_spec);
2021                         str_spec.precision = precision;
2022                         break;
2023                 case 'p':       /* phandle */
2024                         buf = number(buf, end, (unsigned int)dn->phandle, num_spec);
2025                         break;
2026                 case 'P':       /* path-spec */
2027                         p = fwnode_get_name(of_fwnode_handle(dn));
2028                         if (!p[1])
2029                                 p = "/";
2030                         buf = string(buf, end, p, str_spec);
2031                         break;
2032                 case 'F':       /* flags */
2033                         tbuf[0] = of_node_check_flag(dn, OF_DYNAMIC) ? 'D' : '-';
2034                         tbuf[1] = of_node_check_flag(dn, OF_DETACHED) ? 'd' : '-';
2035                         tbuf[2] = of_node_check_flag(dn, OF_POPULATED) ? 'P' : '-';
2036                         tbuf[3] = of_node_check_flag(dn, OF_POPULATED_BUS) ? 'B' : '-';
2037                         tbuf[4] = 0;
2038                         buf = string_nocheck(buf, end, tbuf, str_spec);
2039                         break;
2040                 case 'c':       /* major compatible string */
2041                         ret = of_property_read_string(dn, "compatible", &p);
2042                         if (!ret)
2043                                 buf = string(buf, end, p, str_spec);
2044                         break;
2045                 case 'C':       /* full compatible string */
2046                         has_mult = false;
2047                         of_property_for_each_string(dn, "compatible", prop, p) {
2048                                 if (has_mult)
2049                                         buf = string_nocheck(buf, end, ",", str_spec);
2050                                 buf = string_nocheck(buf, end, "\"", str_spec);
2051                                 buf = string(buf, end, p, str_spec);
2052                                 buf = string_nocheck(buf, end, "\"", str_spec);
2053
2054                                 has_mult = true;
2055                         }
2056                         break;
2057                 default:
2058                         break;
2059                 }
2060         }
2061
2062         return widen_string(buf, buf - buf_start, end, spec);
2063 }
2064
2065 static noinline_for_stack
2066 char *fwnode_string(char *buf, char *end, struct fwnode_handle *fwnode,
2067                     struct printf_spec spec, const char *fmt)
2068 {
2069         struct printf_spec str_spec = spec;
2070         char *buf_start = buf;
2071
2072         str_spec.field_width = -1;
2073
2074         if (*fmt != 'w')
2075                 return error_string(buf, end, "(%pf?)", spec);
2076
2077         if (check_pointer(&buf, end, fwnode, spec))
2078                 return buf;
2079
2080         fmt++;
2081
2082         switch (*fmt) {
2083         case 'P':       /* name */
2084                 buf = string(buf, end, fwnode_get_name(fwnode), str_spec);
2085                 break;
2086         case 'f':       /* full_name */
2087         default:
2088                 buf = fwnode_full_name_string(fwnode, buf, end);
2089                 break;
2090         }
2091
2092         return widen_string(buf, buf - buf_start, end, spec);
2093 }
2094
2095 /*
2096  * Show a '%p' thing.  A kernel extension is that the '%p' is followed
2097  * by an extra set of alphanumeric characters that are extended format
2098  * specifiers.
2099  *
2100  * Please update scripts/checkpatch.pl when adding/removing conversion
2101  * characters.  (Search for "check for vsprintf extension").
2102  *
2103  * Right now we handle:
2104  *
2105  * - 'S' For symbolic direct pointers (or function descriptors) with offset
2106  * - 's' For symbolic direct pointers (or function descriptors) without offset
2107  * - '[Ss]R' as above with __builtin_extract_return_addr() translation
2108  * - '[Ff]' %pf and %pF were obsoleted and later removed in favor of
2109  *          %ps and %pS. Be careful when re-using these specifiers.
2110  * - 'B' For backtraced symbolic direct pointers with offset
2111  * - 'R' For decoded struct resource, e.g., [mem 0x0-0x1f 64bit pref]
2112  * - 'r' For raw struct resource, e.g., [mem 0x0-0x1f flags 0x201]
2113  * - 'b[l]' For a bitmap, the number of bits is determined by the field
2114  *       width which must be explicitly specified either as part of the
2115  *       format string '%32b[l]' or through '%*b[l]', [l] selects
2116  *       range-list format instead of hex format
2117  * - 'M' For a 6-byte MAC address, it prints the address in the
2118  *       usual colon-separated hex notation
2119  * - 'm' For a 6-byte MAC address, it prints the hex address without colons
2120  * - 'MF' For a 6-byte MAC FDDI address, it prints the address
2121  *       with a dash-separated hex notation
2122  * - '[mM]R' For a 6-byte MAC address, Reverse order (Bluetooth)
2123  * - 'I' [46] for IPv4/IPv6 addresses printed in the usual way
2124  *       IPv4 uses dot-separated decimal without leading 0's (1.2.3.4)
2125  *       IPv6 uses colon separated network-order 16 bit hex with leading 0's
2126  *       [S][pfs]
2127  *       Generic IPv4/IPv6 address (struct sockaddr *) that falls back to
2128  *       [4] or [6] and is able to print port [p], flowinfo [f], scope [s]
2129  * - 'i' [46] for 'raw' IPv4/IPv6 addresses
2130  *       IPv6 omits the colons (01020304...0f)
2131  *       IPv4 uses dot-separated decimal with leading 0's (010.123.045.006)
2132  *       [S][pfs]
2133  *       Generic IPv4/IPv6 address (struct sockaddr *) that falls back to
2134  *       [4] or [6] and is able to print port [p], flowinfo [f], scope [s]
2135  * - '[Ii][4S][hnbl]' IPv4 addresses in host, network, big or little endian order
2136  * - 'I[6S]c' for IPv6 addresses printed as specified by
2137  *       http://tools.ietf.org/html/rfc5952
2138  * - 'E[achnops]' For an escaped buffer, where rules are defined by combination
2139  *                of the following flags (see string_escape_mem() for the
2140  *                details):
2141  *                  a - ESCAPE_ANY
2142  *                  c - ESCAPE_SPECIAL
2143  *                  h - ESCAPE_HEX
2144  *                  n - ESCAPE_NULL
2145  *                  o - ESCAPE_OCTAL
2146  *                  p - ESCAPE_NP
2147  *                  s - ESCAPE_SPACE
2148  *                By default ESCAPE_ANY_NP is used.
2149  * - 'U' For a 16 byte UUID/GUID, it prints the UUID/GUID in the form
2150  *       "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx"
2151  *       Options for %pU are:
2152  *         b big endian lower case hex (default)
2153  *         B big endian UPPER case hex
2154  *         l little endian lower case hex
2155  *         L little endian UPPER case hex
2156  *           big endian output byte order is:
2157  *             [0][1][2][3]-[4][5]-[6][7]-[8][9]-[10][11][12][13][14][15]
2158  *           little endian output byte order is:
2159  *             [3][2][1][0]-[5][4]-[7][6]-[8][9]-[10][11][12][13][14][15]
2160  * - 'V' For a struct va_format which contains a format string * and va_list *,
2161  *       call vsnprintf(->format, *->va_list).
2162  *       Implements a "recursive vsnprintf".
2163  *       Do not use this feature without some mechanism to verify the
2164  *       correctness of the format string and va_list arguments.
2165  * - 'K' For a kernel pointer that should be hidden from unprivileged users
2166  * - 'NF' For a netdev_features_t
2167  * - 'h[CDN]' For a variable-length buffer, it prints it as a hex string with
2168  *            a certain separator (' ' by default):
2169  *              C colon
2170  *              D dash
2171  *              N no separator
2172  *            The maximum supported length is 64 bytes of the input. Consider
2173  *            to use print_hex_dump() for the larger input.
2174  * - 'a[pd]' For address types [p] phys_addr_t, [d] dma_addr_t and derivatives
2175  *           (default assumed to be phys_addr_t, passed by reference)
2176  * - 'd[234]' For a dentry name (optionally 2-4 last components)
2177  * - 'D[234]' Same as 'd' but for a struct file
2178  * - 'g' For block_device name (gendisk + partition number)
2179  * - 't[RT][dt][r]' For time and date as represented by:
2180  *      R    struct rtc_time
2181  *      T    time64_t
2182  * - 'C' For a clock, it prints the name (Common Clock Framework) or address
2183  *       (legacy clock framework) of the clock
2184  * - 'Cn' For a clock, it prints the name (Common Clock Framework) or address
2185  *        (legacy clock framework) of the clock
2186  * - 'G' For flags to be printed as a collection of symbolic strings that would
2187  *       construct the specific value. Supported flags given by option:
2188  *       p page flags (see struct page) given as pointer to unsigned long
2189  *       g gfp flags (GFP_* and __GFP_*) given as pointer to gfp_t
2190  *       v vma flags (VM_*) given as pointer to unsigned long
2191  * - 'OF[fnpPcCF]'  For a device tree object
2192  *                  Without any optional arguments prints the full_name
2193  *                  f device node full_name
2194  *                  n device node name
2195  *                  p device node phandle
2196  *                  P device node path spec (name + @unit)
2197  *                  F device node flags
2198  *                  c major compatible string
2199  *                  C full compatible string
2200  * - 'fw[fP]'   For a firmware node (struct fwnode_handle) pointer
2201  *              Without an option prints the full name of the node
2202  *              f full name
2203  *              P node name, including a possible unit address
2204  * - 'x' For printing the address. Equivalent to "%lx".
2205  * - '[ku]s' For a BPF/tracing related format specifier, e.g. used out of
2206  *           bpf_trace_printk() where [ku] prefix specifies either kernel (k)
2207  *           or user (u) memory to probe, and:
2208  *              s a string, equivalent to "%s" on direct vsnprintf() use
2209  *
2210  * ** When making changes please also update:
2211  *      Documentation/core-api/printk-formats.rst
2212  *
2213  * Note: The default behaviour (unadorned %p) is to hash the address,
2214  * rendering it useful as a unique identifier.
2215  */
2216 static noinline_for_stack
2217 char *pointer(const char *fmt, char *buf, char *end, void *ptr,
2218               struct printf_spec spec)
2219 {
2220         switch (*fmt) {
2221         case 'S':
2222         case 's':
2223                 ptr = dereference_symbol_descriptor(ptr);
2224                 /* Fallthrough */
2225         case 'B':
2226                 return symbol_string(buf, end, ptr, spec, fmt);
2227         case 'R':
2228         case 'r':
2229                 return resource_string(buf, end, ptr, spec, fmt);
2230         case 'h':
2231                 return hex_string(buf, end, ptr, spec, fmt);
2232         case 'b':
2233                 switch (fmt[1]) {
2234                 case 'l':
2235                         return bitmap_list_string(buf, end, ptr, spec, fmt);
2236                 default:
2237                         return bitmap_string(buf, end, ptr, spec, fmt);
2238                 }
2239         case 'M':                       /* Colon separated: 00:01:02:03:04:05 */
2240         case 'm':                       /* Contiguous: 000102030405 */
2241                                         /* [mM]F (FDDI) */
2242                                         /* [mM]R (Reverse order; Bluetooth) */
2243                 return mac_address_string(buf, end, ptr, spec, fmt);
2244         case 'I':                       /* Formatted IP supported
2245                                          * 4:   1.2.3.4
2246                                          * 6:   0001:0203:...:0708
2247                                          * 6c:  1::708 or 1::1.2.3.4
2248                                          */
2249         case 'i':                       /* Contiguous:
2250                                          * 4:   001.002.003.004
2251                                          * 6:   000102...0f
2252                                          */
2253                 return ip_addr_string(buf, end, ptr, spec, fmt);
2254         case 'E':
2255                 return escaped_string(buf, end, ptr, spec, fmt);
2256         case 'U':
2257                 return uuid_string(buf, end, ptr, spec, fmt);
2258         case 'V':
2259                 return va_format(buf, end, ptr, spec, fmt);
2260         case 'K':
2261                 return restricted_pointer(buf, end, ptr, spec);
2262         case 'N':
2263                 return netdev_bits(buf, end, ptr, spec, fmt);
2264         case 'a':
2265                 return address_val(buf, end, ptr, spec, fmt);
2266         case 'd':
2267                 return dentry_name(buf, end, ptr, spec, fmt);
2268         case 't':
2269                 return time_and_date(buf, end, ptr, spec, fmt);
2270         case 'C':
2271                 return clock(buf, end, ptr, spec, fmt);
2272         case 'D':
2273                 return file_dentry_name(buf, end, ptr, spec, fmt);
2274 #ifdef CONFIG_BLOCK
2275         case 'g':
2276                 return bdev_name(buf, end, ptr, spec, fmt);
2277 #endif
2278
2279         case 'G':
2280                 return flags_string(buf, end, ptr, spec, fmt);
2281         case 'O':
2282                 return device_node_string(buf, end, ptr, spec, fmt + 1);
2283         case 'f':
2284                 return fwnode_string(buf, end, ptr, spec, fmt + 1);
2285         case 'x':
2286                 return pointer_string(buf, end, ptr, spec);
2287         case 'e':
2288                 /* %pe with a non-ERR_PTR gets treated as plain %p */
2289                 if (!IS_ERR(ptr))
2290                         break;
2291                 return err_ptr(buf, end, ptr, spec);
2292         case 'u':
2293         case 'k':
2294                 switch (fmt[1]) {
2295                 case 's':
2296                         return string(buf, end, ptr, spec);
2297                 default:
2298                         return error_string(buf, end, "(einval)", spec);
2299                 }
2300         }
2301
2302         /* default is to _not_ leak addresses, hash before printing */
2303         return ptr_to_id(buf, end, ptr, spec);
2304 }
2305
2306 /*
2307  * Helper function to decode printf style format.
2308  * Each call decode a token from the format and return the
2309  * number of characters read (or likely the delta where it wants
2310  * to go on the next call).
2311  * The decoded token is returned through the parameters
2312  *
2313  * 'h', 'l', or 'L' for integer fields
2314  * 'z' support added 23/7/1999 S.H.
2315  * 'z' changed to 'Z' --davidm 1/25/99
2316  * 'Z' changed to 'z' --adobriyan 2017-01-25
2317  * 't' added for ptrdiff_t
2318  *
2319  * @fmt: the format string
2320  * @type of the token returned
2321  * @flags: various flags such as +, -, # tokens..
2322  * @field_width: overwritten width
2323  * @base: base of the number (octal, hex, ...)
2324  * @precision: precision of a number
2325  * @qualifier: qualifier of a number (long, size_t, ...)
2326  */
2327 static noinline_for_stack
2328 int format_decode(const char *fmt, struct printf_spec *spec)
2329 {
2330         const char *start = fmt;
2331         char qualifier;
2332
2333         /* we finished early by reading the field width */
2334         if (spec->type == FORMAT_TYPE_WIDTH) {
2335                 if (spec->field_width < 0) {
2336                         spec->field_width = -spec->field_width;
2337                         spec->flags |= LEFT;
2338                 }
2339                 spec->type = FORMAT_TYPE_NONE;
2340                 goto precision;
2341         }
2342
2343         /* we finished early by reading the precision */
2344         if (spec->type == FORMAT_TYPE_PRECISION) {
2345                 if (spec->precision < 0)
2346                         spec->precision = 0;
2347
2348                 spec->type = FORMAT_TYPE_NONE;
2349                 goto qualifier;
2350         }
2351
2352         /* By default */
2353         spec->type = FORMAT_TYPE_NONE;
2354
2355         for (; *fmt ; ++fmt) {
2356                 if (*fmt == '%')
2357                         break;
2358         }
2359
2360         /* Return the current non-format string */
2361         if (fmt != start || !*fmt)
2362                 return fmt - start;
2363
2364         /* Process flags */
2365         spec->flags = 0;
2366
2367         while (1) { /* this also skips first '%' */
2368                 bool found = true;
2369
2370                 ++fmt;
2371
2372                 switch (*fmt) {
2373                 case '-': spec->flags |= LEFT;    break;
2374                 case '+': spec->flags |= PLUS;    break;
2375                 case ' ': spec->flags |= SPACE;   break;
2376                 case '#': spec->flags |= SPECIAL; break;
2377                 case '0': spec->flags |= ZEROPAD; break;
2378                 default:  found = false;
2379                 }
2380
2381                 if (!found)
2382                         break;
2383         }
2384
2385         /* get field width */
2386         spec->field_width = -1;
2387
2388         if (isdigit(*fmt))
2389                 spec->field_width = skip_atoi(&fmt);
2390         else if (*fmt == '*') {
2391                 /* it's the next argument */
2392                 spec->type = FORMAT_TYPE_WIDTH;
2393                 return ++fmt - start;
2394         }
2395
2396 precision:
2397         /* get the precision */
2398         spec->precision = -1;
2399         if (*fmt == '.') {
2400                 ++fmt;
2401                 if (isdigit(*fmt)) {
2402                         spec->precision = skip_atoi(&fmt);
2403                         if (spec->precision < 0)
2404                                 spec->precision = 0;
2405                 } else if (*fmt == '*') {
2406                         /* it's the next argument */
2407                         spec->type = FORMAT_TYPE_PRECISION;
2408                         return ++fmt - start;
2409                 }
2410         }
2411
2412 qualifier:
2413         /* get the conversion qualifier */
2414         qualifier = 0;
2415         if (*fmt == 'h' || _tolower(*fmt) == 'l' ||
2416             *fmt == 'z' || *fmt == 't') {
2417                 qualifier = *fmt++;
2418                 if (unlikely(qualifier == *fmt)) {
2419                         if (qualifier == 'l') {
2420                                 qualifier = 'L';
2421                                 ++fmt;
2422                         } else if (qualifier == 'h') {
2423                                 qualifier = 'H';
2424                                 ++fmt;
2425                         }
2426                 }
2427         }
2428
2429         /* default base */
2430         spec->base = 10;
2431         switch (*fmt) {
2432         case 'c':
2433                 spec->type = FORMAT_TYPE_CHAR;
2434                 return ++fmt - start;
2435
2436         case 's':
2437                 spec->type = FORMAT_TYPE_STR;
2438                 return ++fmt - start;
2439
2440         case 'p':
2441                 spec->type = FORMAT_TYPE_PTR;
2442                 return ++fmt - start;
2443
2444         case '%':
2445                 spec->type = FORMAT_TYPE_PERCENT_CHAR;
2446                 return ++fmt - start;
2447
2448         /* integer number formats - set up the flags and "break" */
2449         case 'o':
2450                 spec->base = 8;
2451                 break;
2452
2453         case 'x':
2454                 spec->flags |= SMALL;
2455                 /* fall through */
2456
2457         case 'X':
2458                 spec->base = 16;
2459                 break;
2460
2461         case 'd':
2462         case 'i':
2463                 spec->flags |= SIGN;
2464         case 'u':
2465                 break;
2466
2467         case 'n':
2468                 /*
2469                  * Since %n poses a greater security risk than
2470                  * utility, treat it as any other invalid or
2471                  * unsupported format specifier.
2472                  */
2473                 /* Fall-through */
2474
2475         default:
2476                 WARN_ONCE(1, "Please remove unsupported %%%c in format string\n", *fmt);
2477                 spec->type = FORMAT_TYPE_INVALID;
2478                 return fmt - start;
2479         }
2480
2481         if (qualifier == 'L')
2482                 spec->type = FORMAT_TYPE_LONG_LONG;
2483         else if (qualifier == 'l') {
2484                 BUILD_BUG_ON(FORMAT_TYPE_ULONG + SIGN != FORMAT_TYPE_LONG);
2485                 spec->type = FORMAT_TYPE_ULONG + (spec->flags & SIGN);
2486         } else if (qualifier == 'z') {
2487                 spec->type = FORMAT_TYPE_SIZE_T;
2488         } else if (qualifier == 't') {
2489                 spec->type = FORMAT_TYPE_PTRDIFF;
2490         } else if (qualifier == 'H') {
2491                 BUILD_BUG_ON(FORMAT_TYPE_UBYTE + SIGN != FORMAT_TYPE_BYTE);
2492                 spec->type = FORMAT_TYPE_UBYTE + (spec->flags & SIGN);
2493         } else if (qualifier == 'h') {
2494                 BUILD_BUG_ON(FORMAT_TYPE_USHORT + SIGN != FORMAT_TYPE_SHORT);
2495                 spec->type = FORMAT_TYPE_USHORT + (spec->flags & SIGN);
2496         } else {
2497                 BUILD_BUG_ON(FORMAT_TYPE_UINT + SIGN != FORMAT_TYPE_INT);
2498                 spec->type = FORMAT_TYPE_UINT + (spec->flags & SIGN);
2499         }
2500
2501         return ++fmt - start;
2502 }
2503
2504 static void
2505 set_field_width(struct printf_spec *spec, int width)
2506 {
2507         spec->field_width = width;
2508         if (WARN_ONCE(spec->field_width != width, "field width %d too large", width)) {
2509                 spec->field_width = clamp(width, -FIELD_WIDTH_MAX, FIELD_WIDTH_MAX);
2510         }
2511 }
2512
2513 static void
2514 set_precision(struct printf_spec *spec, int prec)
2515 {
2516         spec->precision = prec;
2517         if (WARN_ONCE(spec->precision != prec, "precision %d too large", prec)) {
2518                 spec->precision = clamp(prec, 0, PRECISION_MAX);
2519         }
2520 }
2521
2522 /**
2523  * vsnprintf - Format a string and place it in a buffer
2524  * @buf: The buffer to place the result into
2525  * @size: The size of the buffer, including the trailing null space
2526  * @fmt: The format string to use
2527  * @args: Arguments for the format string
2528  *
2529  * This function generally follows C99 vsnprintf, but has some
2530  * extensions and a few limitations:
2531  *
2532  *  - ``%n`` is unsupported
2533  *  - ``%p*`` is handled by pointer()
2534  *
2535  * See pointer() or Documentation/core-api/printk-formats.rst for more
2536  * extensive description.
2537  *
2538  * **Please update the documentation in both places when making changes**
2539  *
2540  * The return value is the number of characters which would
2541  * be generated for the given input, excluding the trailing
2542  * '\0', as per ISO C99. If you want to have the exact
2543  * number of characters written into @buf as return value
2544  * (not including the trailing '\0'), use vscnprintf(). If the
2545  * return is greater than or equal to @size, the resulting
2546  * string is truncated.
2547  *
2548  * If you're not already dealing with a va_list consider using snprintf().
2549  */
2550 int vsnprintf(char *buf, size_t size, const char *fmt, va_list args)
2551 {
2552         unsigned long long num;
2553         char *str, *end;
2554         struct printf_spec spec = {0};
2555
2556         /* Reject out-of-range values early.  Large positive sizes are
2557            used for unknown buffer sizes. */
2558         if (WARN_ON_ONCE(size > INT_MAX))
2559                 return 0;
2560
2561         str = buf;
2562         end = buf + size;
2563
2564         /* Make sure end is always >= buf */
2565         if (end < buf) {
2566                 end = ((void *)-1);
2567                 size = end - buf;
2568         }
2569
2570         while (*fmt) {
2571                 const char *old_fmt = fmt;
2572                 int read = format_decode(fmt, &spec);
2573
2574                 fmt += read;
2575
2576                 switch (spec.type) {
2577                 case FORMAT_TYPE_NONE: {
2578                         int copy = read;
2579                         if (str < end) {
2580                                 if (copy > end - str)
2581                                         copy = end - str;
2582                                 memcpy(str, old_fmt, copy);
2583                         }
2584                         str += read;
2585                         break;
2586                 }
2587
2588                 case FORMAT_TYPE_WIDTH:
2589                         set_field_width(&spec, va_arg(args, int));
2590                         break;
2591
2592                 case FORMAT_TYPE_PRECISION:
2593                         set_precision(&spec, va_arg(args, int));
2594                         break;
2595
2596                 case FORMAT_TYPE_CHAR: {
2597                         char c;
2598
2599                         if (!(spec.flags & LEFT)) {
2600                                 while (--spec.field_width > 0) {
2601                                         if (str < end)
2602                                                 *str = ' ';
2603                                         ++str;
2604
2605                                 }
2606                         }
2607                         c = (unsigned char) va_arg(args, int);
2608                         if (str < end)
2609                                 *str = c;
2610                         ++str;
2611                         while (--spec.field_width > 0) {
2612                                 if (str < end)
2613                                         *str = ' ';
2614                                 ++str;
2615                         }
2616                         break;
2617                 }
2618
2619                 case FORMAT_TYPE_STR:
2620                         str = string(str, end, va_arg(args, char *), spec);
2621                         break;
2622
2623                 case FORMAT_TYPE_PTR:
2624                         str = pointer(fmt, str, end, va_arg(args, void *),
2625                                       spec);
2626                         while (isalnum(*fmt))
2627                                 fmt++;
2628                         break;
2629
2630                 case FORMAT_TYPE_PERCENT_CHAR:
2631                         if (str < end)
2632                                 *str = '%';
2633                         ++str;
2634                         break;
2635
2636                 case FORMAT_TYPE_INVALID:
2637                         /*
2638                          * Presumably the arguments passed gcc's type
2639                          * checking, but there is no safe or sane way
2640                          * for us to continue parsing the format and
2641                          * fetching from the va_list; the remaining
2642                          * specifiers and arguments would be out of
2643                          * sync.
2644                          */
2645                         goto out;
2646
2647                 default:
2648                         switch (spec.type) {
2649                         case FORMAT_TYPE_LONG_LONG:
2650                                 num = va_arg(args, long long);
2651                                 break;
2652                         case FORMAT_TYPE_ULONG:
2653                                 num = va_arg(args, unsigned long);
2654                                 break;
2655                         case FORMAT_TYPE_LONG:
2656                                 num = va_arg(args, long);
2657                                 break;
2658                         case FORMAT_TYPE_SIZE_T:
2659                                 if (spec.flags & SIGN)
2660                                         num = va_arg(args, ssize_t);
2661                                 else
2662                                         num = va_arg(args, size_t);
2663                                 break;
2664                         case FORMAT_TYPE_PTRDIFF:
2665                                 num = va_arg(args, ptrdiff_t);
2666                                 break;
2667                         case FORMAT_TYPE_UBYTE:
2668                                 num = (unsigned char) va_arg(args, int);
2669                                 break;
2670                         case FORMAT_TYPE_BYTE:
2671                                 num = (signed char) va_arg(args, int);
2672                                 break;
2673                         case FORMAT_TYPE_USHORT:
2674                                 num = (unsigned short) va_arg(args, int);
2675                                 break;
2676                         case FORMAT_TYPE_SHORT:
2677                                 num = (short) va_arg(args, int);
2678                                 break;
2679                         case FORMAT_TYPE_INT:
2680                                 num = (int) va_arg(args, int);
2681                                 break;
2682                         default:
2683                                 num = va_arg(args, unsigned int);
2684                         }
2685
2686                         str = number(str, end, num, spec);
2687                 }
2688         }
2689
2690 out:
2691         if (size > 0) {
2692                 if (str < end)
2693                         *str = '\0';
2694                 else
2695                         end[-1] = '\0';
2696         }
2697
2698         /* the trailing null byte doesn't count towards the total */
2699         return str-buf;
2700
2701 }
2702 EXPORT_SYMBOL(vsnprintf);
2703
2704 /**
2705  * vscnprintf - Format a string and place it in a buffer
2706  * @buf: The buffer to place the result into
2707  * @size: The size of the buffer, including the trailing null space
2708  * @fmt: The format string to use
2709  * @args: Arguments for the format string
2710  *
2711  * The return value is the number of characters which have been written into
2712  * the @buf not including the trailing '\0'. If @size is == 0 the function
2713  * returns 0.
2714  *
2715  * If you're not already dealing with a va_list consider using scnprintf().
2716  *
2717  * See the vsnprintf() documentation for format string extensions over C99.
2718  */
2719 int vscnprintf(char *buf, size_t size, const char *fmt, va_list args)
2720 {
2721         int i;
2722
2723         i = vsnprintf(buf, size, fmt, args);
2724
2725         if (likely(i < size))
2726                 return i;
2727         if (size != 0)
2728                 return size - 1;
2729         return 0;
2730 }
2731 EXPORT_SYMBOL(vscnprintf);
2732
2733 /**
2734  * snprintf - Format a string and place it in a buffer
2735  * @buf: The buffer to place the result into
2736  * @size: The size of the buffer, including the trailing null space
2737  * @fmt: The format string to use
2738  * @...: Arguments for the format string
2739  *
2740  * The return value is the number of characters which would be
2741  * generated for the given input, excluding the trailing null,
2742  * as per ISO C99.  If the return is greater than or equal to
2743  * @size, the resulting string is truncated.
2744  *
2745  * See the vsnprintf() documentation for format string extensions over C99.
2746  */
2747 int snprintf(char *buf, size_t size, const char *fmt, ...)
2748 {
2749         va_list args;
2750         int i;
2751
2752         va_start(args, fmt);
2753         i = vsnprintf(buf, size, fmt, args);
2754         va_end(args);
2755
2756         return i;
2757 }
2758 EXPORT_SYMBOL(snprintf);
2759
2760 /**
2761  * scnprintf - Format a string and place it in a buffer
2762  * @buf: The buffer to place the result into
2763  * @size: The size of the buffer, including the trailing null space
2764  * @fmt: The format string to use
2765  * @...: Arguments for the format string
2766  *
2767  * The return value is the number of characters written into @buf not including
2768  * the trailing '\0'. If @size is == 0 the function returns 0.
2769  */
2770
2771 int scnprintf(char *buf, size_t size, const char *fmt, ...)
2772 {
2773         va_list args;
2774         int i;
2775
2776         va_start(args, fmt);
2777         i = vscnprintf(buf, size, fmt, args);
2778         va_end(args);
2779
2780         return i;
2781 }
2782 EXPORT_SYMBOL(scnprintf);
2783
2784 /**
2785  * vsprintf - Format a string and place it in a buffer
2786  * @buf: The buffer to place the result into
2787  * @fmt: The format string to use
2788  * @args: Arguments for the format string
2789  *
2790  * The function returns the number of characters written
2791  * into @buf. Use vsnprintf() or vscnprintf() in order to avoid
2792  * buffer overflows.
2793  *
2794  * If you're not already dealing with a va_list consider using sprintf().
2795  *
2796  * See the vsnprintf() documentation for format string extensions over C99.
2797  */
2798 int vsprintf(char *buf, const char *fmt, va_list args)
2799 {
2800         return vsnprintf(buf, INT_MAX, fmt, args);
2801 }
2802 EXPORT_SYMBOL(vsprintf);
2803
2804 /**
2805  * sprintf - Format a string and place it in a buffer
2806  * @buf: The buffer to place the result into
2807  * @fmt: The format string to use
2808  * @...: Arguments for the format string
2809  *
2810  * The function returns the number of characters written
2811  * into @buf. Use snprintf() or scnprintf() in order to avoid
2812  * buffer overflows.
2813  *
2814  * See the vsnprintf() documentation for format string extensions over C99.
2815  */
2816 int sprintf(char *buf, const char *fmt, ...)
2817 {
2818         va_list args;
2819         int i;
2820
2821         va_start(args, fmt);
2822         i = vsnprintf(buf, INT_MAX, fmt, args);
2823         va_end(args);
2824
2825         return i;
2826 }
2827 EXPORT_SYMBOL(sprintf);
2828
2829 #ifdef CONFIG_BINARY_PRINTF
2830 /*
2831  * bprintf service:
2832  * vbin_printf() - VA arguments to binary data
2833  * bstr_printf() - Binary data to text string
2834  */
2835
2836 /**
2837  * vbin_printf - Parse a format string and place args' binary value in a buffer
2838  * @bin_buf: The buffer to place args' binary value
2839  * @size: The size of the buffer(by words(32bits), not characters)
2840  * @fmt: The format string to use
2841  * @args: Arguments for the format string
2842  *
2843  * The format follows C99 vsnprintf, except %n is ignored, and its argument
2844  * is skipped.
2845  *
2846  * The return value is the number of words(32bits) which would be generated for
2847  * the given input.
2848  *
2849  * NOTE:
2850  * If the return value is greater than @size, the resulting bin_buf is NOT
2851  * valid for bstr_printf().
2852  */
2853 int vbin_printf(u32 *bin_buf, size_t size, const char *fmt, va_list args)
2854 {
2855         struct printf_spec spec = {0};
2856         char *str, *end;
2857         int width;
2858
2859         str = (char *)bin_buf;
2860         end = (char *)(bin_buf + size);
2861
2862 #define save_arg(type)                                                  \
2863 ({                                                                      \
2864         unsigned long long value;                                       \
2865         if (sizeof(type) == 8) {                                        \
2866                 unsigned long long val8;                                \
2867                 str = PTR_ALIGN(str, sizeof(u32));                      \
2868                 val8 = va_arg(args, unsigned long long);                \
2869                 if (str + sizeof(type) <= end) {                        \
2870                         *(u32 *)str = *(u32 *)&val8;                    \
2871                         *(u32 *)(str + 4) = *((u32 *)&val8 + 1);        \
2872                 }                                                       \
2873                 value = val8;                                           \
2874         } else {                                                        \
2875                 unsigned int val4;                                      \
2876                 str = PTR_ALIGN(str, sizeof(type));                     \
2877                 val4 = va_arg(args, int);                               \
2878                 if (str + sizeof(type) <= end)                          \
2879                         *(typeof(type) *)str = (type)(long)val4;        \
2880                 value = (unsigned long long)val4;                       \
2881         }                                                               \
2882         str += sizeof(type);                                            \
2883         value;                                                          \
2884 })
2885
2886         while (*fmt) {
2887                 int read = format_decode(fmt, &spec);
2888
2889                 fmt += read;
2890
2891                 switch (spec.type) {
2892                 case FORMAT_TYPE_NONE:
2893                 case FORMAT_TYPE_PERCENT_CHAR:
2894                         break;
2895                 case FORMAT_TYPE_INVALID:
2896                         goto out;
2897
2898                 case FORMAT_TYPE_WIDTH:
2899                 case FORMAT_TYPE_PRECISION:
2900                         width = (int)save_arg(int);
2901                         /* Pointers may require the width */
2902                         if (*fmt == 'p')
2903                                 set_field_width(&spec, width);
2904                         break;
2905
2906                 case FORMAT_TYPE_CHAR:
2907                         save_arg(char);
2908                         break;
2909
2910                 case FORMAT_TYPE_STR: {
2911                         const char *save_str = va_arg(args, char *);
2912                         const char *err_msg;
2913                         size_t len;
2914
2915                         err_msg = check_pointer_msg(save_str);
2916                         if (err_msg)
2917                                 save_str = err_msg;
2918
2919                         len = strlen(save_str) + 1;
2920                         if (str + len < end)
2921                                 memcpy(str, save_str, len);
2922                         str += len;
2923                         break;
2924                 }
2925
2926                 case FORMAT_TYPE_PTR:
2927                         /* Dereferenced pointers must be done now */
2928                         switch (*fmt) {
2929                         /* Dereference of functions is still OK */
2930                         case 'S':
2931                         case 's':
2932                         case 'x':
2933                         case 'K':
2934                         case 'e':
2935                                 save_arg(void *);
2936                                 break;
2937                         default:
2938                                 if (!isalnum(*fmt)) {
2939                                         save_arg(void *);
2940                                         break;
2941                                 }
2942                                 str = pointer(fmt, str, end, va_arg(args, void *),
2943                                               spec);
2944                                 if (str + 1 < end)
2945                                         *str++ = '\0';
2946                                 else
2947                                         end[-1] = '\0'; /* Must be nul terminated */
2948                         }
2949                         /* skip all alphanumeric pointer suffixes */
2950                         while (isalnum(*fmt))
2951                                 fmt++;
2952                         break;
2953
2954                 default:
2955                         switch (spec.type) {
2956
2957                         case FORMAT_TYPE_LONG_LONG:
2958                                 save_arg(long long);
2959                                 break;
2960                         case FORMAT_TYPE_ULONG:
2961                         case FORMAT_TYPE_LONG:
2962                                 save_arg(unsigned long);
2963                                 break;
2964                         case FORMAT_TYPE_SIZE_T:
2965                                 save_arg(size_t);
2966                                 break;
2967                         case FORMAT_TYPE_PTRDIFF:
2968                                 save_arg(ptrdiff_t);
2969                                 break;
2970                         case FORMAT_TYPE_UBYTE:
2971                         case FORMAT_TYPE_BYTE:
2972                                 save_arg(char);
2973                                 break;
2974                         case FORMAT_TYPE_USHORT:
2975                         case FORMAT_TYPE_SHORT:
2976                                 save_arg(short);
2977                                 break;
2978                         default:
2979                                 save_arg(int);
2980                         }
2981                 }
2982         }
2983
2984 out:
2985         return (u32 *)(PTR_ALIGN(str, sizeof(u32))) - bin_buf;
2986 #undef save_arg
2987 }
2988 EXPORT_SYMBOL_GPL(vbin_printf);
2989
2990 /**
2991  * bstr_printf - Format a string from binary arguments and place it in a buffer
2992  * @buf: The buffer to place the result into
2993  * @size: The size of the buffer, including the trailing null space
2994  * @fmt: The format string to use
2995  * @bin_buf: Binary arguments for the format string
2996  *
2997  * This function like C99 vsnprintf, but the difference is that vsnprintf gets
2998  * arguments from stack, and bstr_printf gets arguments from @bin_buf which is
2999  * a binary buffer that generated by vbin_printf.
3000  *
3001  * The format follows C99 vsnprintf, but has some extensions:
3002  *  see vsnprintf comment for details.
3003  *
3004  * The return value is the number of characters which would
3005  * be generated for the given input, excluding the trailing
3006  * '\0', as per ISO C99. If you want to have the exact
3007  * number of characters written into @buf as return value
3008  * (not including the trailing '\0'), use vscnprintf(). If the
3009  * return is greater than or equal to @size, the resulting
3010  * string is truncated.
3011  */
3012 int bstr_printf(char *buf, size_t size, const char *fmt, const u32 *bin_buf)
3013 {
3014         struct printf_spec spec = {0};
3015         char *str, *end;
3016         const char *args = (const char *)bin_buf;
3017
3018         if (WARN_ON_ONCE(size > INT_MAX))
3019                 return 0;
3020
3021         str = buf;
3022         end = buf + size;
3023
3024 #define get_arg(type)                                                   \
3025 ({                                                                      \
3026         typeof(type) value;                                             \
3027         if (sizeof(type) == 8) {                                        \
3028                 args = PTR_ALIGN(args, sizeof(u32));                    \
3029                 *(u32 *)&value = *(u32 *)args;                          \
3030                 *((u32 *)&value + 1) = *(u32 *)(args + 4);              \
3031         } else {                                                        \
3032                 args = PTR_ALIGN(args, sizeof(type));                   \
3033                 value = *(typeof(type) *)args;                          \
3034         }                                                               \
3035         args += sizeof(type);                                           \
3036         value;                                                          \
3037 })
3038
3039         /* Make sure end is always >= buf */
3040         if (end < buf) {
3041                 end = ((void *)-1);
3042                 size = end - buf;
3043         }
3044
3045         while (*fmt) {
3046                 const char *old_fmt = fmt;
3047                 int read = format_decode(fmt, &spec);
3048
3049                 fmt += read;
3050
3051                 switch (spec.type) {
3052                 case FORMAT_TYPE_NONE: {
3053                         int copy = read;
3054                         if (str < end) {
3055                                 if (copy > end - str)
3056                                         copy = end - str;
3057                                 memcpy(str, old_fmt, copy);
3058                         }
3059                         str += read;
3060                         break;
3061                 }
3062
3063                 case FORMAT_TYPE_WIDTH:
3064                         set_field_width(&spec, get_arg(int));
3065                         break;
3066
3067                 case FORMAT_TYPE_PRECISION:
3068                         set_precision(&spec, get_arg(int));
3069                         break;
3070
3071                 case FORMAT_TYPE_CHAR: {
3072                         char c;
3073
3074                         if (!(spec.flags & LEFT)) {
3075                                 while (--spec.field_width > 0) {
3076                                         if (str < end)
3077                                                 *str = ' ';
3078                                         ++str;
3079                                 }
3080                         }
3081                         c = (unsigned char) get_arg(char);
3082                         if (str < end)
3083                                 *str = c;
3084                         ++str;
3085                         while (--spec.field_width > 0) {
3086                                 if (str < end)
3087                                         *str = ' ';
3088                                 ++str;
3089                         }
3090                         break;
3091                 }
3092
3093                 case FORMAT_TYPE_STR: {
3094                         const char *str_arg = args;
3095                         args += strlen(str_arg) + 1;
3096                         str = string(str, end, (char *)str_arg, spec);
3097                         break;
3098                 }
3099
3100                 case FORMAT_TYPE_PTR: {
3101                         bool process = false;
3102                         int copy, len;
3103                         /* Non function dereferences were already done */
3104                         switch (*fmt) {
3105                         case 'S':
3106                         case 's':
3107                         case 'F':
3108                         case 'f':
3109                         case 'x':
3110                         case 'K':
3111                         case 'e':
3112                                 process = true;
3113                                 break;
3114                         default:
3115                                 if (!isalnum(*fmt)) {
3116                                         process = true;
3117                                         break;
3118                                 }
3119                                 /* Pointer dereference was already processed */
3120                                 if (str < end) {
3121                                         len = copy = strlen(args);
3122                                         if (copy > end - str)
3123                                                 copy = end - str;
3124                                         memcpy(str, args, copy);
3125                                         str += len;
3126                                         args += len + 1;
3127                                 }
3128                         }
3129                         if (process)
3130                                 str = pointer(fmt, str, end, get_arg(void *), spec);
3131
3132                         while (isalnum(*fmt))
3133                                 fmt++;
3134                         break;
3135                 }
3136
3137                 case FORMAT_TYPE_PERCENT_CHAR:
3138                         if (str < end)
3139                                 *str = '%';
3140                         ++str;
3141                         break;
3142
3143                 case FORMAT_TYPE_INVALID:
3144                         goto out;
3145
3146                 default: {
3147                         unsigned long long num;
3148
3149                         switch (spec.type) {
3150
3151                         case FORMAT_TYPE_LONG_LONG:
3152                                 num = get_arg(long long);
3153                                 break;
3154                         case FORMAT_TYPE_ULONG:
3155                         case FORMAT_TYPE_LONG:
3156                                 num = get_arg(unsigned long);
3157                                 break;
3158                         case FORMAT_TYPE_SIZE_T:
3159                                 num = get_arg(size_t);
3160                                 break;
3161                         case FORMAT_TYPE_PTRDIFF:
3162                                 num = get_arg(ptrdiff_t);
3163                                 break;
3164                         case FORMAT_TYPE_UBYTE:
3165                                 num = get_arg(unsigned char);
3166                                 break;
3167                         case FORMAT_TYPE_BYTE:
3168                                 num = get_arg(signed char);
3169                                 break;
3170                         case FORMAT_TYPE_USHORT:
3171                                 num = get_arg(unsigned short);
3172                                 break;
3173                         case FORMAT_TYPE_SHORT:
3174                                 num = get_arg(short);
3175                                 break;
3176                         case FORMAT_TYPE_UINT:
3177                                 num = get_arg(unsigned int);
3178                                 break;
3179                         default:
3180                                 num = get_arg(int);
3181                         }
3182
3183                         str = number(str, end, num, spec);
3184                 } /* default: */
3185                 } /* switch(spec.type) */
3186         } /* while(*fmt) */
3187
3188 out:
3189         if (size > 0) {
3190                 if (str < end)
3191                         *str = '\0';
3192                 else
3193                         end[-1] = '\0';
3194         }
3195
3196 #undef get_arg
3197
3198         /* the trailing null byte doesn't count towards the total */
3199         return str - buf;
3200 }
3201 EXPORT_SYMBOL_GPL(bstr_printf);
3202
3203 /**
3204  * bprintf - Parse a format string and place args' binary value in a buffer
3205  * @bin_buf: The buffer to place args' binary value
3206  * @size: The size of the buffer(by words(32bits), not characters)
3207  * @fmt: The format string to use
3208  * @...: Arguments for the format string
3209  *
3210  * The function returns the number of words(u32) written
3211  * into @bin_buf.
3212  */
3213 int bprintf(u32 *bin_buf, size_t size, const char *fmt, ...)
3214 {
3215         va_list args;
3216         int ret;
3217
3218         va_start(args, fmt);
3219         ret = vbin_printf(bin_buf, size, fmt, args);
3220         va_end(args);
3221
3222         return ret;
3223 }
3224 EXPORT_SYMBOL_GPL(bprintf);
3225
3226 #endif /* CONFIG_BINARY_PRINTF */
3227
3228 /**
3229  * vsscanf - Unformat a buffer into a list of arguments
3230  * @buf:        input buffer
3231  * @fmt:        format of buffer
3232  * @args:       arguments
3233  */
3234 int vsscanf(const char *buf, const char *fmt, va_list args)
3235 {
3236         const char *str = buf;
3237         char *next;
3238         char digit;
3239         int num = 0;
3240         u8 qualifier;
3241         unsigned int base;
3242         union {
3243                 long long s;
3244                 unsigned long long u;
3245         } val;
3246         s16 field_width;
3247         bool is_sign;
3248
3249         while (*fmt) {
3250                 /* skip any white space in format */
3251                 /* white space in format matchs any amount of
3252                  * white space, including none, in the input.
3253                  */
3254                 if (isspace(*fmt)) {
3255                         fmt = skip_spaces(++fmt);
3256                         str = skip_spaces(str);
3257                 }
3258
3259                 /* anything that is not a conversion must match exactly */
3260                 if (*fmt != '%' && *fmt) {
3261                         if (*fmt++ != *str++)
3262                                 break;
3263                         continue;
3264                 }
3265
3266                 if (!*fmt)
3267                         break;
3268                 ++fmt;
3269
3270                 /* skip this conversion.
3271                  * advance both strings to next white space
3272                  */
3273                 if (*fmt == '*') {
3274                         if (!*str)
3275                                 break;
3276                         while (!isspace(*fmt) && *fmt != '%' && *fmt) {
3277                                 /* '%*[' not yet supported, invalid format */
3278                                 if (*fmt == '[')
3279                                         return num;
3280                                 fmt++;
3281                         }
3282                         while (!isspace(*str) && *str)
3283                                 str++;
3284                         continue;
3285                 }
3286
3287                 /* get field width */
3288                 field_width = -1;
3289                 if (isdigit(*fmt)) {
3290                         field_width = skip_atoi(&fmt);
3291                         if (field_width <= 0)
3292                                 break;
3293                 }
3294
3295                 /* get conversion qualifier */
3296                 qualifier = -1;
3297                 if (*fmt == 'h' || _tolower(*fmt) == 'l' ||
3298                     *fmt == 'z') {
3299                         qualifier = *fmt++;
3300                         if (unlikely(qualifier == *fmt)) {
3301                                 if (qualifier == 'h') {
3302                                         qualifier = 'H';
3303                                         fmt++;
3304                                 } else if (qualifier == 'l') {
3305                                         qualifier = 'L';
3306                                         fmt++;
3307                                 }
3308                         }
3309                 }
3310
3311                 if (!*fmt)
3312                         break;
3313
3314                 if (*fmt == 'n') {
3315                         /* return number of characters read so far */
3316                         *va_arg(args, int *) = str - buf;
3317                         ++fmt;
3318                         continue;
3319                 }
3320
3321                 if (!*str)
3322                         break;
3323
3324                 base = 10;
3325                 is_sign = false;
3326
3327                 switch (*fmt++) {
3328                 case 'c':
3329                 {
3330                         char *s = (char *)va_arg(args, char*);
3331                         if (field_width == -1)
3332                                 field_width = 1;
3333                         do {
3334                                 *s++ = *str++;
3335                         } while (--field_width > 0 && *str);
3336                         num++;
3337                 }
3338                 continue;
3339                 case 's':
3340                 {
3341                         char *s = (char *)va_arg(args, char *);
3342                         if (field_width == -1)
3343                                 field_width = SHRT_MAX;
3344                         /* first, skip leading white space in buffer */
3345                         str = skip_spaces(str);
3346
3347                         /* now copy until next white space */
3348                         while (*str && !isspace(*str) && field_width--)
3349                                 *s++ = *str++;
3350                         *s = '\0';
3351                         num++;
3352                 }
3353                 continue;
3354                 /*
3355                  * Warning: This implementation of the '[' conversion specifier
3356                  * deviates from its glibc counterpart in the following ways:
3357                  * (1) It does NOT support ranges i.e. '-' is NOT a special
3358                  *     character
3359                  * (2) It cannot match the closing bracket ']' itself
3360                  * (3) A field width is required
3361                  * (4) '%*[' (discard matching input) is currently not supported
3362                  *
3363                  * Example usage:
3364                  * ret = sscanf("00:0a:95","%2[^:]:%2[^:]:%2[^:]",
3365                  *              buf1, buf2, buf3);
3366                  * if (ret < 3)
3367                  *    // etc..
3368                  */
3369                 case '[':
3370                 {
3371                         char *s = (char *)va_arg(args, char *);
3372                         DECLARE_BITMAP(set, 256) = {0};
3373                         unsigned int len = 0;
3374                         bool negate = (*fmt == '^');
3375
3376                         /* field width is required */
3377                         if (field_width == -1)
3378                                 return num;
3379
3380                         if (negate)
3381                                 ++fmt;
3382
3383                         for ( ; *fmt && *fmt != ']'; ++fmt, ++len)
3384                                 set_bit((u8)*fmt, set);
3385
3386                         /* no ']' or no character set found */
3387                         if (!*fmt || !len)
3388                                 return num;
3389                         ++fmt;
3390
3391                         if (negate) {
3392                                 bitmap_complement(set, set, 256);
3393                                 /* exclude null '\0' byte */
3394                                 clear_bit(0, set);
3395                         }
3396
3397                         /* match must be non-empty */
3398                         if (!test_bit((u8)*str, set))
3399                                 return num;
3400
3401                         while (test_bit((u8)*str, set) && field_width--)
3402                                 *s++ = *str++;
3403                         *s = '\0';
3404                         ++num;
3405                 }
3406                 continue;
3407                 case 'o':
3408                         base = 8;
3409                         break;
3410                 case 'x':
3411                 case 'X':
3412                         base = 16;
3413                         break;
3414                 case 'i':
3415                         base = 0;
3416                         /* fall through */
3417                 case 'd':
3418                         is_sign = true;
3419                         /* fall through */
3420                 case 'u':
3421                         break;
3422                 case '%':
3423                         /* looking for '%' in str */
3424                         if (*str++ != '%')
3425                                 return num;
3426                         continue;
3427                 default:
3428                         /* invalid format; stop here */
3429                         return num;
3430                 }
3431
3432                 /* have some sort of integer conversion.
3433                  * first, skip white space in buffer.
3434                  */
3435                 str = skip_spaces(str);
3436
3437                 digit = *str;
3438                 if (is_sign && digit == '-')
3439                         digit = *(str + 1);
3440
3441                 if (!digit
3442                     || (base == 16 && !isxdigit(digit))
3443                     || (base == 10 && !isdigit(digit))
3444                     || (base == 8 && (!isdigit(digit) || digit > '7'))
3445                     || (base == 0 && !isdigit(digit)))
3446                         break;
3447
3448                 if (is_sign)
3449                         val.s = qualifier != 'L' ?
3450                                 simple_strtol(str, &next, base) :
3451                                 simple_strtoll(str, &next, base);
3452                 else
3453                         val.u = qualifier != 'L' ?
3454                                 simple_strtoul(str, &next, base) :
3455                                 simple_strtoull(str, &next, base);
3456
3457                 if (field_width > 0 && next - str > field_width) {
3458                         if (base == 0)
3459                                 _parse_integer_fixup_radix(str, &base);
3460                         while (next - str > field_width) {
3461                                 if (is_sign)
3462                                         val.s = div_s64(val.s, base);
3463                                 else
3464                                         val.u = div_u64(val.u, base);
3465                                 --next;
3466                         }
3467                 }
3468
3469                 switch (qualifier) {
3470                 case 'H':       /* that's 'hh' in format */
3471                         if (is_sign)
3472                                 *va_arg(args, signed char *) = val.s;
3473                         else
3474                                 *va_arg(args, unsigned char *) = val.u;
3475                         break;
3476                 case 'h':
3477                         if (is_sign)
3478                                 *va_arg(args, short *) = val.s;
3479                         else
3480                                 *va_arg(args, unsigned short *) = val.u;
3481                         break;
3482                 case 'l':
3483                         if (is_sign)
3484                                 *va_arg(args, long *) = val.s;
3485                         else
3486                                 *va_arg(args, unsigned long *) = val.u;
3487                         break;
3488                 case 'L':
3489                         if (is_sign)
3490                                 *va_arg(args, long long *) = val.s;
3491                         else
3492                                 *va_arg(args, unsigned long long *) = val.u;
3493                         break;
3494                 case 'z':
3495                         *va_arg(args, size_t *) = val.u;
3496                         break;
3497                 default:
3498                         if (is_sign)
3499                                 *va_arg(args, int *) = val.s;
3500                         else
3501                                 *va_arg(args, unsigned int *) = val.u;
3502                         break;
3503                 }
3504                 num++;
3505
3506                 if (!next)
3507                         break;
3508                 str = next;
3509         }
3510
3511         return num;
3512 }
3513 EXPORT_SYMBOL(vsscanf);
3514
3515 /**
3516  * sscanf - Unformat a buffer into a list of arguments
3517  * @buf:        input buffer
3518  * @fmt:        formatting of buffer
3519  * @...:        resulting arguments
3520  */
3521 int sscanf(const char *buf, const char *fmt, ...)
3522 {
3523         va_list args;
3524         int i;
3525
3526         va_start(args, fmt);
3527         i = vsscanf(buf, fmt, args);
3528         va_end(args);
3529
3530         return i;
3531 }
3532 EXPORT_SYMBOL(sscanf);