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 <linux/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/sprintf.h>
  38 #include <linux/time.h>
  39 #include <linux/uuid.h>
  40 #include <linux/of.h>
  41 #include <net/addrconf.h>
  42 #include <linux/siphash.h>
  43 #include <linux/compiler.h>
  44 #include <linux/property.h>
  45 #include <linux/notifier.h>
  46 #ifdef CONFIG_BLOCK
  47 #include <linux/blkdev.h>
  48 #endif
  49
  50 #include "../mm/internal.h"     /* For the trace_print_flags arrays */
  51
  52 #include <asm/page.h>           /* for PAGE_SIZE */
  53 #include <asm/byteorder.h>      /* cpu_to_le16 */
  54 #include <linux/unaligned.h>
  55
  56 #include <linux/string_helpers.h>
  57 #include "kstrtox.h"
  58
  59 /* Disable pointer hashing if requested */
  60 bool no_hash_pointers __ro_after_init;
  61 EXPORT_SYMBOL_GPL(no_hash_pointers);
  62
  63 noinline
  64 static unsigned long long simple_strntoull(const char *startp, char **endp, unsigned int base, size_t max_chars)
  65 {
  66         const char *cp;
  67         unsigned long long result = 0ULL;
  68         size_t prefix_chars;
  69         unsigned int rv;
  70
  71         cp = _parse_integer_fixup_radix(startp, &base);
  72         prefix_chars = cp - startp;
  73         if (prefix_chars < max_chars) {
  74                 rv = _parse_integer_limit(cp, base, &result, max_chars - prefix_chars);
  75                 /* FIXME */
  76                 cp += (rv & ~KSTRTOX_OVERFLOW);
  77         } else {
  78                 /* Field too short for prefix + digit, skip over without converting */
  79                 cp = startp + max_chars;
  80         }
  81
  82         if (endp)
  83                 *endp = (char *)cp;
  84
  85         return result;
  86 }
  87
  88 /**
  89  * simple_strtoull - convert a string to an unsigned long long
  90  * @cp: The start of the string
  91  * @endp: A pointer to the end of the parsed string will be placed here
  92  * @base: The number base to use
  93  *
  94  * This function has caveats. Please use kstrtoull instead.
  95  */
  96 noinline
  97 unsigned long long simple_strtoull(const char *cp, char **endp, unsigned int base)
  98 {
  99         return simple_strntoull(cp, endp, base, INT_MAX);
 100 }
 101 EXPORT_SYMBOL(simple_strtoull);
 102
 103 /**
 104  * simple_strtoul - convert a string to an unsigned long
 105  * @cp: The start of the string
 106  * @endp: A pointer to the end of the parsed string will be placed here
 107  * @base: The number base to use
 108  *
 109  * This function has caveats. Please use kstrtoul instead.
 110  */
 111 unsigned long simple_strtoul(const char *cp, char **endp, unsigned int base)
 112 {
 113         return simple_strtoull(cp, endp, base);
 114 }
 115 EXPORT_SYMBOL(simple_strtoul);
 116
 117 /**
 118  * simple_strtol - convert a string to a signed long
 119  * @cp: The start of the string
 120  * @endp: A pointer to the end of the parsed string will be placed here
 121  * @base: The number base to use
 122  *
 123  * This function has caveats. Please use kstrtol instead.
 124  */
 125 long simple_strtol(const char *cp, char **endp, unsigned int base)
 126 {
 127         if (*cp == '-')
 128                 return -simple_strtoul(cp + 1, endp, base);
 129
 130         return simple_strtoul(cp, endp, base);
 131 }
 132 EXPORT_SYMBOL(simple_strtol);
 133
 134 noinline
 135 static long long simple_strntoll(const char *cp, char **endp, unsigned int base, size_t max_chars)
 136 {
 137         /*
 138          * simple_strntoull() safely handles receiving max_chars==0 in the
 139          * case cp[0] == '-' && max_chars == 1.
 140          * If max_chars == 0 we can drop through and pass it to simple_strntoull()
 141          * and the content of *cp is irrelevant.
 142          */
 143         if (*cp == '-' && max_chars > 0)
 144                 return -simple_strntoull(cp + 1, endp, base, max_chars - 1);
 145
 146         return simple_strntoull(cp, endp, base, max_chars);
 147 }
 148
 149 /**
 150  * simple_strtoll - convert a string to a signed long long
 151  * @cp: The start of the string
 152  * @endp: A pointer to the end of the parsed string will be placed here
 153  * @base: The number base to use
 154  *
 155  * This function has caveats. Please use kstrtoll instead.
 156  */
 157 long long simple_strtoll(const char *cp, char **endp, unsigned int base)
 158 {
 159         return simple_strntoll(cp, endp, base, INT_MAX);
 160 }
 161 EXPORT_SYMBOL(simple_strtoll);
 162
 163 static noinline_for_stack
 164 int skip_atoi(const char **s)
 165 {
 166         int i = 0;
 167
 168         do {
 169                 i = i*10 + *((*s)++) - '0';
 170         } while (isdigit(**s));
 171
 172         return i;
 173 }
 174
 175 /*
 176  * Decimal conversion is by far the most typical, and is used for
 177  * /proc and /sys data. This directly impacts e.g. top performance
 178  * with many processes running. We optimize it for speed by emitting
 179  * two characters at a time, using a 200 byte lookup table. This
 180  * roughly halves the number of multiplications compared to computing
 181  * the digits one at a time. Implementation strongly inspired by the
 182  * previous version, which in turn used ideas described at
 183  * <http://www.cs.uiowa.edu/~jones/bcd/divide.html> (with permission
 184  * from the author, Douglas W. Jones).
 185  *
 186  * It turns out there is precisely one 26 bit fixed-point
 187  * approximation a of 64/100 for which x/100 == (x * (u64)a) >> 32
 188  * holds for all x in [0, 10^8-1], namely a = 0x28f5c29. The actual
 189  * range happens to be somewhat larger (x <= 1073741898), but that's
 190  * irrelevant for our purpose.
 191  *
 192  * For dividing a number in the range [10^4, 10^6-1] by 100, we still
 193  * need a 32x32->64 bit multiply, so we simply use the same constant.
 194  *
 195  * For dividing a number in the range [100, 10^4-1] by 100, there are
 196  * several options. The simplest is (x * 0x147b) >> 19, which is valid
 197  * for all x <= 43698.
 198  */
 199
 200 static const u16 decpair[100] = {
 201 #define _(x) (__force u16) cpu_to_le16(((x % 10) | ((x / 10) << 8)) + 0x3030)
 202         _( 0), _( 1), _( 2), _( 3), _( 4), _( 5), _( 6), _( 7), _( 8), _( 9),
 203         _(10), _(11), _(12), _(13), _(14), _(15), _(16), _(17), _(18), _(19),
 204         _(20), _(21), _(22), _(23), _(24), _(25), _(26), _(27), _(28), _(29),
 205         _(30), _(31), _(32), _(33), _(34), _(35), _(36), _(37), _(38), _(39),
 206         _(40), _(41), _(42), _(43), _(44), _(45), _(46), _(47), _(48), _(49),
 207         _(50), _(51), _(52), _(53), _(54), _(55), _(56), _(57), _(58), _(59),
 208         _(60), _(61), _(62), _(63), _(64), _(65), _(66), _(67), _(68), _(69),
 209         _(70), _(71), _(72), _(73), _(74), _(75), _(76), _(77), _(78), _(79),
 210         _(80), _(81), _(82), _(83), _(84), _(85), _(86), _(87), _(88), _(89),
 211         _(90), _(91), _(92), _(93), _(94), _(95), _(96), _(97), _(98), _(99),
 212 #undef _
 213 };
 214
 215 /*
 216  * This will print a single '0' even if r == 0, since we would
 217  * immediately jump to out_r where two 0s would be written but only
 218  * one of them accounted for in buf. This is needed by ip4_string
 219  * below. All other callers pass a non-zero value of r.
 220 */
 221 static noinline_for_stack
 222 char *put_dec_trunc8(char *buf, unsigned r)
 223 {
 224         unsigned q;
 225
 226         /* 1 <= r < 10^8 */
 227         if (r < 100)
 228                 goto out_r;
 229
 230         /* 100 <= r < 10^8 */
 231         q = (r * (u64)0x28f5c29) >> 32;
 232         *((u16 *)buf) = decpair[r - 100*q];
 233         buf += 2;
 234
 235         /* 1 <= q < 10^6 */
 236         if (q < 100)
 237                 goto out_q;
 238
 239         /*  100 <= q < 10^6 */
 240         r = (q * (u64)0x28f5c29) >> 32;
 241         *((u16 *)buf) = decpair[q - 100*r];
 242         buf += 2;
 243
 244         /* 1 <= r < 10^4 */
 245         if (r < 100)
 246                 goto out_r;
 247
 248         /* 100 <= r < 10^4 */
 249         q = (r * 0x147b) >> 19;
 250         *((u16 *)buf) = decpair[r - 100*q];
 251         buf += 2;
 252 out_q:
 253         /* 1 <= q < 100 */
 254         r = q;
 255 out_r:
 256         /* 1 <= r < 100 */
 257         *((u16 *)buf) = decpair[r];
 258         buf += r < 10 ? 1 : 2;
 259         return buf;
 260 }
 261
 262 #if BITS_PER_LONG == 64 && BITS_PER_LONG_LONG == 64
 263 static noinline_for_stack
 264 char *put_dec_full8(char *buf, unsigned r)
 265 {
 266         unsigned q;
 267
 268         /* 0 <= r < 10^8 */
 269         q = (r * (u64)0x28f5c29) >> 32;
 270         *((u16 *)buf) = decpair[r - 100*q];
 271         buf += 2;
 272
 273         /* 0 <= q < 10^6 */
 274         r = (q * (u64)0x28f5c29) >> 32;
 275         *((u16 *)buf) = decpair[q - 100*r];
 276         buf += 2;
 277
 278         /* 0 <= r < 10^4 */
 279         q = (r * 0x147b) >> 19;
 280         *((u16 *)buf) = decpair[r - 100*q];
 281         buf += 2;
 282
 283         /* 0 <= q < 100 */
 284         *((u16 *)buf) = decpair[q];
 285         buf += 2;
 286         return buf;
 287 }
 288
 289 static noinline_for_stack
 290 char *put_dec(char *buf, unsigned long long n)
 291 {
 292         if (n >= 100*1000*1000)
 293                 buf = put_dec_full8(buf, do_div(n, 100*1000*1000));
 294         /* 1 <= n <= 1.6e11 */
 295         if (n >= 100*1000*1000)
 296                 buf = put_dec_full8(buf, do_div(n, 100*1000*1000));
 297         /* 1 <= n < 1e8 */
 298         return put_dec_trunc8(buf, n);
 299 }
 300
 301 #elif BITS_PER_LONG == 32 && BITS_PER_LONG_LONG == 64
 302
 303 static void
 304 put_dec_full4(char *buf, unsigned r)
 305 {
 306         unsigned q;
 307
 308         /* 0 <= r < 10^4 */
 309         q = (r * 0x147b) >> 19;
 310         *((u16 *)buf) = decpair[r - 100*q];
 311         buf += 2;
 312         /* 0 <= q < 100 */
 313         *((u16 *)buf) = decpair[q];
 314 }
 315
 316 /*
 317  * Call put_dec_full4 on x % 10000, return x / 10000.
 318  * The approximation x/10000 == (x * 0x346DC5D7) >> 43
 319  * holds for all x < 1,128,869,999.  The largest value this
 320  * helper will ever be asked to convert is 1,125,520,955.
 321  * (second call in the put_dec code, assuming n is all-ones).
 322  */
 323 static noinline_for_stack
 324 unsigned put_dec_helper4(char *buf, unsigned x)
 325 {
 326         uint32_t q = (x * (uint64_t)0x346DC5D7) >> 43;
 327
 328         put_dec_full4(buf, x - q * 10000);
 329         return q;
 330 }
 331
 332 /* Based on code by Douglas W. Jones found at
 333  * <http://www.cs.uiowa.edu/~jones/bcd/decimal.html#sixtyfour>
 334  * (with permission from the author).
 335  * Performs no 64-bit division and hence should be fast on 32-bit machines.
 336  */
 337 static
 338 char *put_dec(char *buf, unsigned long long n)
 339 {
 340         uint32_t d3, d2, d1, q, h;
 341
 342         if (n < 100*1000*1000)
 343                 return put_dec_trunc8(buf, n);
 344
 345         d1  = ((uint32_t)n >> 16); /* implicit "& 0xffff" */
 346         h   = (n >> 32);
 347         d2  = (h      ) & 0xffff;
 348         d3  = (h >> 16); /* implicit "& 0xffff" */
 349
 350         /* n = 2^48 d3 + 2^32 d2 + 2^16 d1 + d0
 351              = 281_4749_7671_0656 d3 + 42_9496_7296 d2 + 6_5536 d1 + d0 */
 352         q   = 656 * d3 + 7296 * d2 + 5536 * d1 + ((uint32_t)n & 0xffff);
 353         q = put_dec_helper4(buf, q);
 354
 355         q += 7671 * d3 + 9496 * d2 + 6 * d1;
 356         q = put_dec_helper4(buf+4, q);
 357
 358         q += 4749 * d3 + 42 * d2;
 359         q = put_dec_helper4(buf+8, q);
 360
 361         q += 281 * d3;
 362         buf += 12;
 363         if (q)
 364                 buf = put_dec_trunc8(buf, q);
 365         else while (buf[-1] == '0')
 366                 --buf;
 367
 368         return buf;
 369 }
 370
 371 #endif
 372
 373 /*
 374  * Convert passed number to decimal string.
 375  * Returns the length of string.  On buffer overflow, returns 0.
 376  *
 377  * If speed is not important, use snprintf(). It's easy to read the code.
 378  */
 379 int num_to_str(char *buf, int size, unsigned long long num, unsigned int width)
 380 {
 381         /* put_dec requires 2-byte alignment of the buffer. */
 382         char tmp[sizeof(num) * 3] __aligned(2);
 383         int idx, len;
 384
 385         /* put_dec() may work incorrectly for num = 0 (generate "", not "0") */
 386         if (num <= 9) {
 387                 tmp[0] = '0' + num;
 388                 len = 1;
 389         } else {
 390                 len = put_dec(tmp, num) - tmp;
 391         }
 392
 393         if (len > size || width > size)
 394                 return 0;
 395
 396         if (width > len) {
 397                 width = width - len;
 398                 for (idx = 0; idx < width; idx++)
 399                         buf[idx] = ' ';
 400         } else {
 401                 width = 0;
 402         }
 403
 404         for (idx = 0; idx < len; ++idx)
 405                 buf[idx + width] = tmp[len - idx - 1];
 406
 407         return len + width;
 408 }
 409
 410 #define SIGN    1               /* unsigned/signed, must be 1 */
 411 #define LEFT    2               /* left justified */
 412 #define PLUS    4               /* show plus */
 413 #define SPACE   8               /* space if plus */
 414 #define ZEROPAD 16              /* pad with zero, must be 16 == '0' - ' ' */
 415 #define SMALL   32              /* use lowercase in hex (must be 32 == 0x20) */
 416 #define SPECIAL 64              /* prefix hex with "0x", octal with "0" */
 417
 418 static_assert(SIGN == 1);
 419 static_assert(ZEROPAD == ('0' - ' '));
 420 static_assert(SMALL == ('a' ^ 'A'));
 421
 422 enum format_type {
 423         FORMAT_TYPE_NONE, /* Just a string part */
 424         FORMAT_TYPE_WIDTH,
 425         FORMAT_TYPE_PRECISION,
 426         FORMAT_TYPE_CHAR,
 427         FORMAT_TYPE_STR,
 428         FORMAT_TYPE_PTR,
 429         FORMAT_TYPE_PERCENT_CHAR,
 430         FORMAT_TYPE_INVALID,
 431         FORMAT_TYPE_LONG_LONG,
 432         FORMAT_TYPE_ULONG,
 433         FORMAT_TYPE_LONG,
 434         FORMAT_TYPE_UBYTE,
 435         FORMAT_TYPE_BYTE,
 436         FORMAT_TYPE_USHORT,
 437         FORMAT_TYPE_SHORT,
 438         FORMAT_TYPE_UINT,
 439         FORMAT_TYPE_INT,
 440         FORMAT_TYPE_SIZE_T,
 441         FORMAT_TYPE_PTRDIFF
 442 };
 443
 444 struct printf_spec {
 445         unsigned int    type:8;         /* format_type enum */
 446         signed int      field_width:24; /* width of output field */
 447         unsigned int    flags:8;        /* flags to number() */
 448         unsigned int    base:8;         /* number base, 8, 10 or 16 only */
 449         signed int      precision:16;   /* # of digits/chars */
 450 } __packed;
 451 static_assert(sizeof(struct printf_spec) == 8);
 452
 453 #define FIELD_WIDTH_MAX ((1 << 23) - 1)
 454 #define PRECISION_MAX ((1 << 15) - 1)
 455
 456 static noinline_for_stack
 457 char *number(char *buf, char *end, unsigned long long num,
 458              struct printf_spec spec)
 459 {
 460         /* put_dec requires 2-byte alignment of the buffer. */
 461         char tmp[3 * sizeof(num)] __aligned(2);
 462         char sign;
 463         char locase;
 464         int need_pfx = ((spec.flags & SPECIAL) && spec.base != 10);
 465         int i;
 466         bool is_zero = num == 0LL;
 467         int field_width = spec.field_width;
 468         int precision = spec.precision;
 469
 470         /* locase = 0 or 0x20. ORing digits or letters with 'locase'
 471          * produces same digits or (maybe lowercased) letters */
 472         locase = (spec.flags & SMALL);
 473         if (spec.flags & LEFT)
 474                 spec.flags &= ~ZEROPAD;
 475         sign = 0;
 476         if (spec.flags & SIGN) {
 477                 if ((signed long long)num < 0) {
 478                         sign = '-';
 479                         num = -(signed long long)num;
 480                         field_width--;
 481                 } else if (spec.flags & PLUS) {
 482                         sign = '+';
 483                         field_width--;
 484                 } else if (spec.flags & SPACE) {
 485                         sign = ' ';
 486                         field_width--;
 487                 }
 488         }
 489         if (need_pfx) {
 490                 if (spec.base == 16)
 491                         field_width -= 2;
 492                 else if (!is_zero)
 493                         field_width--;
 494         }
 495
 496         /* generate full string in tmp[], in reverse order */
 497         i = 0;
 498         if (num < spec.base)
 499                 tmp[i++] = hex_asc_upper[num] | locase;
 500         else if (spec.base != 10) { /* 8 or 16 */
 501                 int mask = spec.base - 1;
 502                 int shift = 3;
 503
 504                 if (spec.base == 16)
 505                         shift = 4;
 506                 do {
 507                         tmp[i++] = (hex_asc_upper[((unsigned char)num) & mask] | locase);
 508                         num >>= shift;
 509                 } while (num);
 510         } else { /* base 10 */
 511                 i = put_dec(tmp, num) - tmp;
 512         }
 513
 514         /* printing 100 using %2d gives "100", not "00" */
 515         if (i > precision)
 516                 precision = i;
 517         /* leading space padding */
 518         field_width -= precision;
 519         if (!(spec.flags & (ZEROPAD | LEFT))) {
 520                 while (--field_width >= 0) {
 521                         if (buf < end)
 522                                 *buf = ' ';
 523                         ++buf;
 524                 }
 525         }
 526         /* sign */
 527         if (sign) {
 528                 if (buf < end)
 529                         *buf = sign;
 530                 ++buf;
 531         }
 532         /* "0x" / "0" prefix */
 533         if (need_pfx) {
 534                 if (spec.base == 16 || !is_zero) {
 535                         if (buf < end)
 536                                 *buf = '0';
 537                         ++buf;
 538                 }
 539                 if (spec.base == 16) {
 540                         if (buf < end)
 541                                 *buf = ('X' | locase);
 542                         ++buf;
 543                 }
 544         }
 545         /* zero or space padding */
 546         if (!(spec.flags & LEFT)) {
 547                 char c = ' ' + (spec.flags & ZEROPAD);
 548
 549                 while (--field_width >= 0) {
 550                         if (buf < end)
 551                                 *buf = c;
 552                         ++buf;
 553                 }
 554         }
 555         /* hmm even more zero padding? */
 556         while (i <= --precision) {
 557                 if (buf < end)
 558                         *buf = '0';
 559                 ++buf;
 560         }
 561         /* actual digits of result */
 562         while (--i >= 0) {
 563                 if (buf < end)
 564                         *buf = tmp[i];
 565                 ++buf;
 566         }
 567         /* trailing space padding */
 568         while (--field_width >= 0) {
 569                 if (buf < end)
 570                         *buf = ' ';
 571                 ++buf;
 572         }
 573
 574         return buf;
 575 }
 576
 577 static noinline_for_stack
 578 char *special_hex_number(char *buf, char *end, unsigned long long num, int size)
 579 {
 580         struct printf_spec spec;
 581
 582         spec.type = FORMAT_TYPE_PTR;
 583         spec.field_width = 2 + 2 * size;        /* 0x + hex */
 584         spec.flags = SPECIAL | SMALL | ZEROPAD;
 585         spec.base = 16;
 586         spec.precision = -1;
 587
 588         return number(buf, end, num, spec);
 589 }
 590
 591 static void move_right(char *buf, char *end, unsigned len, unsigned spaces)
 592 {
 593         size_t size;
 594         if (buf >= end) /* nowhere to put anything */
 595                 return;
 596         size = end - buf;
 597         if (size <= spaces) {
 598                 memset(buf, ' ', size);
 599                 return;
 600         }
 601         if (len) {
 602                 if (len > size - spaces)
 603                         len = size - spaces;
 604                 memmove(buf + spaces, buf, len);
 605         }
 606         memset(buf, ' ', spaces);
 607 }
 608
 609 /*
 610  * Handle field width padding for a string.
 611  * @buf: current buffer position
 612  * @n: length of string
 613  * @end: end of output buffer
 614  * @spec: for field width and flags
 615  * Returns: new buffer position after padding.
 616  */
 617 static noinline_for_stack
 618 char *widen_string(char *buf, int n, char *end, struct printf_spec spec)
 619 {
 620         unsigned spaces;
 621
 622         if (likely(n >= spec.field_width))
 623                 return buf;
 624         /* we want to pad the sucker */
 625         spaces = spec.field_width - n;
 626         if (!(spec.flags & LEFT)) {
 627                 move_right(buf - n, end, n, spaces);
 628                 return buf + spaces;
 629         }
 630         while (spaces--) {
 631                 if (buf < end)
 632                         *buf = ' ';
 633                 ++buf;
 634         }
 635         return buf;
 636 }
 637
 638 /* Handle string from a well known address. */
 639 static char *string_nocheck(char *buf, char *end, const char *s,
 640                             struct printf_spec spec)
 641 {
 642         int len = 0;
 643         int lim = spec.precision;
 644
 645         while (lim--) {
 646                 char c = *s++;
 647                 if (!c)
 648                         break;
 649                 if (buf < end)
 650                         *buf = c;
 651                 ++buf;
 652                 ++len;
 653         }
 654         return widen_string(buf, len, end, spec);
 655 }
 656
 657 static char *err_ptr(char *buf, char *end, void *ptr,
 658                      struct printf_spec spec)
 659 {
 660         int err = PTR_ERR(ptr);
 661         const char *sym = errname(err);
 662
 663         if (sym)
 664                 return string_nocheck(buf, end, sym, spec);
 665
 666         /*
 667          * Somebody passed ERR_PTR(-1234) or some other non-existing
 668          * Efoo - or perhaps CONFIG_SYMBOLIC_ERRNAME=n. Fall back to
 669          * printing it as its decimal representation.
 670          */
 671         spec.flags |= SIGN;
 672         spec.base = 10;
 673         return number(buf, end, err, spec);
 674 }
 675
 676 /* Be careful: error messages must fit into the given buffer. */
 677 static char *error_string(char *buf, char *end, const char *s,
 678                           struct printf_spec spec)
 679 {
 680         /*
 681          * Hard limit to avoid a completely insane messages. It actually
 682          * works pretty well because most error messages are in
 683          * the many pointer format modifiers.
 684          */
 685         if (spec.precision == -1)
 686                 spec.precision = 2 * sizeof(void *);
 687
 688         return string_nocheck(buf, end, s, spec);
 689 }
 690
 691 /*
 692  * Do not call any complex external code here. Nested printk()/vsprintf()
 693  * might cause infinite loops. Failures might break printk() and would
 694  * be hard to debug.
 695  */
 696 static const char *check_pointer_msg(const void *ptr)
 697 {
 698         if (!ptr)
 699                 return "(null)";
 700
 701         if ((unsigned long)ptr < PAGE_SIZE || IS_ERR_VALUE(ptr))
 702                 return "(efault)";
 703
 704         return NULL;
 705 }
 706
 707 static int check_pointer(char **buf, char *end, const void *ptr,
 708                          struct printf_spec spec)
 709 {
 710         const char *err_msg;
 711
 712         err_msg = check_pointer_msg(ptr);
 713         if (err_msg) {
 714                 *buf = error_string(*buf, end, err_msg, spec);
 715                 return -EFAULT;
 716         }
 717
 718         return 0;
 719 }
 720
 721 static noinline_for_stack
 722 char *string(char *buf, char *end, const char *s,
 723              struct printf_spec spec)
 724 {
 725         if (check_pointer(&buf, end, s, spec))
 726                 return buf;
 727
 728         return string_nocheck(buf, end, s, spec);
 729 }
 730
 731 static char *pointer_string(char *buf, char *end,
 732                             const void *ptr,
 733                             struct printf_spec spec)
 734 {
 735         spec.base = 16;
 736         spec.flags |= SMALL;
 737         if (spec.field_width == -1) {
 738                 spec.field_width = 2 * sizeof(ptr);
 739                 spec.flags |= ZEROPAD;
 740         }
 741
 742         return number(buf, end, (unsigned long int)ptr, spec);
 743 }
 744
 745 /* Make pointers available for printing early in the boot sequence. */
 746 static int debug_boot_weak_hash __ro_after_init;
 747
 748 static int __init debug_boot_weak_hash_enable(char *str)
 749 {
 750         debug_boot_weak_hash = 1;
 751         pr_info("debug_boot_weak_hash enabled\n");
 752         return 0;
 753 }
 754 early_param("debug_boot_weak_hash", debug_boot_weak_hash_enable);
 755
 756 static bool filled_random_ptr_key __read_mostly;
 757 static siphash_key_t ptr_key __read_mostly;
 758
 759 static int fill_ptr_key(struct notifier_block *nb, unsigned long action, void *data)
 760 {
 761         get_random_bytes(&ptr_key, sizeof(ptr_key));
 762
 763         /* Pairs with smp_rmb() before reading ptr_key. */
 764         smp_wmb();
 765         WRITE_ONCE(filled_random_ptr_key, true);
 766         return NOTIFY_DONE;
 767 }
 768
 769 static int __init vsprintf_init_hashval(void)
 770 {
 771         static struct notifier_block fill_ptr_key_nb = { .notifier_call = fill_ptr_key };
 772         execute_with_initialized_rng(&fill_ptr_key_nb);
 773         return 0;
 774 }
 775 subsys_initcall(vsprintf_init_hashval)
 776
 777 /* Maps a pointer to a 32 bit unique identifier. */
 778 static inline int __ptr_to_hashval(const void *ptr, unsigned long *hashval_out)
 779 {
 780         unsigned long hashval;
 781
 782         if (!READ_ONCE(filled_random_ptr_key))
 783                 return -EBUSY;
 784
 785         /* Pairs with smp_wmb() after writing ptr_key. */
 786         smp_rmb();
 787
 788 #ifdef CONFIG_64BIT
 789         hashval = (unsigned long)siphash_1u64((u64)ptr, &ptr_key);
 790         /*
 791          * Mask off the first 32 bits, this makes explicit that we have
 792          * modified the address (and 32 bits is plenty for a unique ID).
 793          */
 794         hashval = hashval & 0xffffffff;
 795 #else
 796         hashval = (unsigned long)siphash_1u32((u32)ptr, &ptr_key);
 797 #endif
 798         *hashval_out = hashval;
 799         return 0;
 800 }
 801
 802 int ptr_to_hashval(const void *ptr, unsigned long *hashval_out)
 803 {
 804         return __ptr_to_hashval(ptr, hashval_out);
 805 }
 806
 807 static char *ptr_to_id(char *buf, char *end, const void *ptr,
 808                        struct printf_spec spec)
 809 {
 810         const char *str = sizeof(ptr) == 8 ? "(____ptrval____)" : "(ptrval)";
 811         unsigned long hashval;
 812         int ret;
 813
 814         /*
 815          * Print the real pointer value for NULL and error pointers,
 816          * as they are not actual addresses.
 817          */
 818         if (IS_ERR_OR_NULL(ptr))
 819                 return pointer_string(buf, end, ptr, spec);
 820
 821         /* When debugging early boot use non-cryptographically secure hash. */
 822         if (unlikely(debug_boot_weak_hash)) {
 823                 hashval = hash_long((unsigned long)ptr, 32);
 824                 return pointer_string(buf, end, (const void *)hashval, spec);
 825         }
 826
 827         ret = __ptr_to_hashval(ptr, &hashval);
 828         if (ret) {
 829                 spec.field_width = 2 * sizeof(ptr);
 830                 /* string length must be less than default_width */
 831                 return error_string(buf, end, str, spec);
 832         }
 833
 834         return pointer_string(buf, end, (const void *)hashval, spec);
 835 }
 836
 837 static char *default_pointer(char *buf, char *end, const void *ptr,
 838                              struct printf_spec spec)
 839 {
 840         /*
 841          * default is to _not_ leak addresses, so hash before printing,
 842          * unless no_hash_pointers is specified on the command line.
 843          */
 844         if (unlikely(no_hash_pointers))
 845                 return pointer_string(buf, end, ptr, spec);
 846
 847         return ptr_to_id(buf, end, ptr, spec);
 848 }
 849
 850 int kptr_restrict __read_mostly;
 851
 852 static noinline_for_stack
 853 char *restricted_pointer(char *buf, char *end, const void *ptr,
 854                          struct printf_spec spec)
 855 {
 856         switch (kptr_restrict) {
 857         case 0:
 858                 /* Handle as %p, hash and do _not_ leak addresses. */
 859                 return default_pointer(buf, end, ptr, spec);
 860         case 1: {
 861                 const struct cred *cred;
 862
 863                 /*
 864                  * kptr_restrict==1 cannot be used in IRQ context
 865                  * because its test for CAP_SYSLOG would be meaningless.
 866                  */
 867                 if (in_hardirq() || in_serving_softirq() || in_nmi()) {
 868                         if (spec.field_width == -1)
 869                                 spec.field_width = 2 * sizeof(ptr);
 870                         return error_string(buf, end, "pK-error", spec);
 871                 }
 872
 873                 /*
 874                  * Only print the real pointer value if the current
 875                  * process has CAP_SYSLOG and is running with the
 876                  * same credentials it started with. This is because
 877                  * access to files is checked at open() time, but %pK
 878                  * checks permission at read() time. We don't want to
 879                  * leak pointer values if a binary opens a file using
 880                  * %pK and then elevates privileges before reading it.
 881                  */
 882                 cred = current_cred();
 883                 if (!has_capability_noaudit(current, CAP_SYSLOG) ||
 884                     !uid_eq(cred->euid, cred->uid) ||
 885                     !gid_eq(cred->egid, cred->gid))
 886                         ptr = NULL;
 887                 break;
 888         }
 889         case 2:
 890         default:
 891                 /* Always print 0's for %pK */
 892                 ptr = NULL;
 893                 break;
 894         }
 895
 896         return pointer_string(buf, end, ptr, spec);
 897 }
 898
 899 static noinline_for_stack
 900 char *dentry_name(char *buf, char *end, const struct dentry *d, struct printf_spec spec,
 901                   const char *fmt)
 902 {
 903         const char *array[4], *s;
 904         const struct dentry *p;
 905         int depth;
 906         int i, n;
 907
 908         switch (fmt[1]) {
 909                 case '2': case '3': case '4':
 910                         depth = fmt[1] - '0';
 911                         break;
 912                 default:
 913                         depth = 1;
 914         }
 915
 916         rcu_read_lock();
 917         for (i = 0; i < depth; i++, d = p) {
 918                 if (check_pointer(&buf, end, d, spec)) {
 919                         rcu_read_unlock();
 920                         return buf;
 921                 }
 922
 923                 p = READ_ONCE(d->d_parent);
 924                 array[i] = READ_ONCE(d->d_name.name);
 925                 if (p == d) {
 926                         if (i)
 927                                 array[i] = "";
 928                         i++;
 929                         break;
 930                 }
 931         }
 932         s = array[--i];
 933         for (n = 0; n != spec.precision; n++, buf++) {
 934                 char c = *s++;
 935                 if (!c) {
 936                         if (!i)
 937                                 break;
 938                         c = '/';
 939                         s = array[--i];
 940                 }
 941                 if (buf < end)
 942                         *buf = c;
 943         }
 944         rcu_read_unlock();
 945         return widen_string(buf, n, end, spec);
 946 }
 947
 948 static noinline_for_stack
 949 char *file_dentry_name(char *buf, char *end, const struct file *f,
 950                         struct printf_spec spec, const char *fmt)
 951 {
 952         if (check_pointer(&buf, end, f, spec))
 953                 return buf;
 954
 955         return dentry_name(buf, end, f->f_path.dentry, spec, fmt);
 956 }
 957 #ifdef CONFIG_BLOCK
 958 static noinline_for_stack
 959 char *bdev_name(char *buf, char *end, struct block_device *bdev,
 960                 struct printf_spec spec, const char *fmt)
 961 {
 962         struct gendisk *hd;
 963
 964         if (check_pointer(&buf, end, bdev, spec))
 965                 return buf;
 966
 967         hd = bdev->bd_disk;
 968         buf = string(buf, end, hd->disk_name, spec);
 969         if (bdev_is_partition(bdev)) {
 970                 if (isdigit(hd->disk_name[strlen(hd->disk_name)-1])) {
 971                         if (buf < end)
 972                                 *buf = 'p';
 973                         buf++;
 974                 }
 975                 buf = number(buf, end, bdev_partno(bdev), spec);
 976         }
 977         return buf;
 978 }
 979 #endif
 980
 981 static noinline_for_stack
 982 char *symbol_string(char *buf, char *end, void *ptr,
 983                     struct printf_spec spec, const char *fmt)
 984 {
 985         unsigned long value;
 986 #ifdef CONFIG_KALLSYMS
 987         char sym[KSYM_SYMBOL_LEN];
 988 #endif
 989
 990         if (fmt[1] == 'R')
 991                 ptr = __builtin_extract_return_addr(ptr);
 992         value = (unsigned long)ptr;
 993
 994 #ifdef CONFIG_KALLSYMS
 995         if (*fmt == 'B' && fmt[1] == 'b')
 996                 sprint_backtrace_build_id(sym, value);
 997         else if (*fmt == 'B')
 998                 sprint_backtrace(sym, value);
 999         else if (*fmt == 'S' && (fmt[1] == 'b' || (fmt[1] == 'R' && fmt[2] == 'b')))
1000                 sprint_symbol_build_id(sym, value);
1001         else if (*fmt != 's')
1002                 sprint_symbol(sym, value);
1003         else
1004                 sprint_symbol_no_offset(sym, value);
1005
1006         return string_nocheck(buf, end, sym, spec);
1007 #else
1008         return special_hex_number(buf, end, value, sizeof(void *));
1009 #endif
1010 }
1011
1012 static const struct printf_spec default_str_spec = {
1013         .field_width = -1,
1014         .precision = -1,
1015 };
1016
1017 static const struct printf_spec default_flag_spec = {
1018         .base = 16,
1019         .precision = -1,
1020         .flags = SPECIAL | SMALL,
1021 };
1022
1023 static const struct printf_spec default_dec_spec = {
1024         .base = 10,
1025         .precision = -1,
1026 };
1027
1028 static const struct printf_spec default_dec02_spec = {
1029         .base = 10,
1030         .field_width = 2,
1031         .precision = -1,
1032         .flags = ZEROPAD,
1033 };
1034
1035 static const struct printf_spec default_dec04_spec = {
1036         .base = 10,
1037         .field_width = 4,
1038         .precision = -1,
1039         .flags = ZEROPAD,
1040 };
1041
1042 static noinline_for_stack
1043 char *hex_range(char *buf, char *end, u64 start_val, u64 end_val,
1044                 struct printf_spec spec)
1045 {
1046         buf = number(buf, end, start_val, spec);
1047         if (start_val == end_val)
1048                 return buf;
1049
1050         if (buf < end)
1051                 *buf = '-';
1052         ++buf;
1053         return number(buf, end, end_val, spec);
1054 }
1055
1056 static noinline_for_stack
1057 char *resource_string(char *buf, char *end, struct resource *res,
1058                       struct printf_spec spec, const char *fmt)
1059 {
1060 #ifndef IO_RSRC_PRINTK_SIZE
1061 #define IO_RSRC_PRINTK_SIZE     6
1062 #endif
1063
1064 #ifndef MEM_RSRC_PRINTK_SIZE
1065 #define MEM_RSRC_PRINTK_SIZE    10
1066 #endif
1067         static const struct printf_spec io_spec = {
1068                 .base = 16,
1069                 .field_width = IO_RSRC_PRINTK_SIZE,
1070                 .precision = -1,
1071                 .flags = SPECIAL | SMALL | ZEROPAD,
1072         };
1073         static const struct printf_spec mem_spec = {
1074                 .base = 16,
1075                 .field_width = MEM_RSRC_PRINTK_SIZE,
1076                 .precision = -1,
1077                 .flags = SPECIAL | SMALL | ZEROPAD,
1078         };
1079         static const struct printf_spec bus_spec = {
1080                 .base = 16,
1081                 .field_width = 2,
1082                 .precision = -1,
1083                 .flags = SMALL | ZEROPAD,
1084         };
1085         static const struct printf_spec str_spec = {
1086                 .field_width = -1,
1087                 .precision = 10,
1088                 .flags = LEFT,
1089         };
1090
1091         /* 32-bit res (sizeof==4): 10 chars in dec, 10 in hex ("0x" + 8)
1092          * 64-bit res (sizeof==8): 20 chars in dec, 18 in hex ("0x" + 16) */
1093 #define RSRC_BUF_SIZE           ((2 * sizeof(resource_size_t)) + 4)
1094 #define FLAG_BUF_SIZE           (2 * sizeof(res->flags))
1095 #define DECODED_BUF_SIZE        sizeof("[mem - 64bit pref window disabled]")
1096 #define RAW_BUF_SIZE            sizeof("[mem - flags 0x]")
1097         char sym[MAX(2*RSRC_BUF_SIZE + DECODED_BUF_SIZE,
1098                      2*RSRC_BUF_SIZE + FLAG_BUF_SIZE + RAW_BUF_SIZE)];
1099
1100         char *p = sym, *pend = sym + sizeof(sym);
1101         int decode = (fmt[0] == 'R') ? 1 : 0;
1102         const struct printf_spec *specp;
1103
1104         if (check_pointer(&buf, end, res, spec))
1105                 return buf;
1106
1107         *p++ = '[';
1108         if (res->flags & IORESOURCE_IO) {
1109                 p = string_nocheck(p, pend, "io  ", str_spec);
1110                 specp = &io_spec;
1111         } else if (res->flags & IORESOURCE_MEM) {
1112                 p = string_nocheck(p, pend, "mem ", str_spec);
1113                 specp = &mem_spec;
1114         } else if (res->flags & IORESOURCE_IRQ) {
1115                 p = string_nocheck(p, pend, "irq ", str_spec);
1116                 specp = &default_dec_spec;
1117         } else if (res->flags & IORESOURCE_DMA) {
1118                 p = string_nocheck(p, pend, "dma ", str_spec);
1119                 specp = &default_dec_spec;
1120         } else if (res->flags & IORESOURCE_BUS) {
1121                 p = string_nocheck(p, pend, "bus ", str_spec);
1122                 specp = &bus_spec;
1123         } else {
1124                 p = string_nocheck(p, pend, "??? ", str_spec);
1125                 specp = &mem_spec;
1126                 decode = 0;
1127         }
1128         if (decode && res->flags & IORESOURCE_UNSET) {
1129                 p = string_nocheck(p, pend, "size ", str_spec);
1130                 p = number(p, pend, resource_size(res), *specp);
1131         } else {
1132                 p = hex_range(p, pend, res->start, res->end, *specp);
1133         }
1134         if (decode) {
1135                 if (res->flags & IORESOURCE_MEM_64)
1136                         p = string_nocheck(p, pend, " 64bit", str_spec);
1137                 if (res->flags & IORESOURCE_PREFETCH)
1138                         p = string_nocheck(p, pend, " pref", str_spec);
1139                 if (res->flags & IORESOURCE_WINDOW)
1140                         p = string_nocheck(p, pend, " window", str_spec);
1141                 if (res->flags & IORESOURCE_DISABLED)
1142                         p = string_nocheck(p, pend, " disabled", str_spec);
1143         } else {
1144                 p = string_nocheck(p, pend, " flags ", str_spec);
1145                 p = number(p, pend, res->flags, default_flag_spec);
1146         }
1147         *p++ = ']';
1148         *p = '\0';
1149
1150         return string_nocheck(buf, end, sym, spec);
1151 }
1152
1153 static noinline_for_stack
1154 char *range_string(char *buf, char *end, const struct range *range,
1155                    struct printf_spec spec, const char *fmt)
1156 {
1157         char sym[sizeof("[range 0x0123456789abcdef-0x0123456789abcdef]")];
1158         char *p = sym, *pend = sym + sizeof(sym);
1159
1160         struct printf_spec range_spec = {
1161                 .field_width = 2 + 2 * sizeof(range->start), /* 0x + 2 * 8 */
1162                 .flags = SPECIAL | SMALL | ZEROPAD,
1163                 .base = 16,
1164                 .precision = -1,
1165         };
1166
1167         if (check_pointer(&buf, end, range, spec))
1168                 return buf;
1169
1170         p = string_nocheck(p, pend, "[range ", default_str_spec);
1171         p = hex_range(p, pend, range->start, range->end, range_spec);
1172         *p++ = ']';
1173         *p = '\0';
1174
1175         return string_nocheck(buf, end, sym, spec);
1176 }
1177
1178 static noinline_for_stack
1179 char *hex_string(char *buf, char *end, u8 *addr, struct printf_spec spec,
1180                  const char *fmt)
1181 {
1182         int i, len = 1;         /* if we pass '%ph[CDN]', field width remains
1183                                    negative value, fallback to the default */
1184         char separator;
1185
1186         if (spec.field_width == 0)
1187                 /* nothing to print */
1188                 return buf;
1189
1190         if (check_pointer(&buf, end, addr, spec))
1191                 return buf;
1192
1193         switch (fmt[1]) {
1194         case 'C':
1195                 separator = ':';
1196                 break;
1197         case 'D':
1198                 separator = '-';
1199                 break;
1200         case 'N':
1201                 separator = 0;
1202                 break;
1203         default:
1204                 separator = ' ';
1205                 break;
1206         }
1207
1208         if (spec.field_width > 0)
1209                 len = min_t(int, spec.field_width, 64);
1210
1211         for (i = 0; i < len; ++i) {
1212                 if (buf < end)
1213                         *buf = hex_asc_hi(addr[i]);
1214                 ++buf;
1215                 if (buf < end)
1216                         *buf = hex_asc_lo(addr[i]);
1217                 ++buf;
1218
1219                 if (separator && i != len - 1) {
1220                         if (buf < end)
1221                                 *buf = separator;
1222                         ++buf;
1223                 }
1224         }
1225
1226         return buf;
1227 }
1228
1229 static noinline_for_stack
1230 char *bitmap_string(char *buf, char *end, const unsigned long *bitmap,
1231                     struct printf_spec spec, const char *fmt)
1232 {
1233         const int CHUNKSZ = 32;
1234         int nr_bits = max_t(int, spec.field_width, 0);
1235         int i, chunksz;
1236         bool first = true;
1237
1238         if (check_pointer(&buf, end, bitmap, spec))
1239                 return buf;
1240
1241         /* reused to print numbers */
1242         spec = (struct printf_spec){ .flags = SMALL | ZEROPAD, .base = 16 };
1243
1244         chunksz = nr_bits & (CHUNKSZ - 1);
1245         if (chunksz == 0)
1246                 chunksz = CHUNKSZ;
1247
1248         i = ALIGN(nr_bits, CHUNKSZ) - CHUNKSZ;
1249         for (; i >= 0; i -= CHUNKSZ) {
1250                 u32 chunkmask, val;
1251                 int word, bit;
1252
1253                 chunkmask = ((1ULL << chunksz) - 1);
1254                 word = i / BITS_PER_LONG;
1255                 bit = i % BITS_PER_LONG;
1256                 val = (bitmap[word] >> bit) & chunkmask;
1257
1258                 if (!first) {
1259                         if (buf < end)
1260                                 *buf = ',';
1261                         buf++;
1262                 }
1263                 first = false;
1264
1265                 spec.field_width = DIV_ROUND_UP(chunksz, 4);
1266                 buf = number(buf, end, val, spec);
1267
1268                 chunksz = CHUNKSZ;
1269         }
1270         return buf;
1271 }
1272
1273 static noinline_for_stack
1274 char *bitmap_list_string(char *buf, char *end, const unsigned long *bitmap,
1275                          struct printf_spec spec, const char *fmt)
1276 {
1277         int nr_bits = max_t(int, spec.field_width, 0);
1278         bool first = true;
1279         int rbot, rtop;
1280
1281         if (check_pointer(&buf, end, bitmap, spec))
1282                 return buf;
1283
1284         for_each_set_bitrange(rbot, rtop, bitmap, nr_bits) {
1285                 if (!first) {
1286                         if (buf < end)
1287                                 *buf = ',';
1288                         buf++;
1289                 }
1290                 first = false;
1291
1292                 buf = number(buf, end, rbot, default_dec_spec);
1293                 if (rtop == rbot + 1)
1294                         continue;
1295
1296                 if (buf < end)
1297                         *buf = '-';
1298                 buf = number(++buf, end, rtop - 1, default_dec_spec);
1299         }
1300         return buf;
1301 }
1302
1303 static noinline_for_stack
1304 char *mac_address_string(char *buf, char *end, u8 *addr,
1305                          struct printf_spec spec, const char *fmt)
1306 {
1307         char mac_addr[sizeof("xx:xx:xx:xx:xx:xx")];
1308         char *p = mac_addr;
1309         int i;
1310         char separator;
1311         bool reversed = false;
1312
1313         if (check_pointer(&buf, end, addr, spec))
1314                 return buf;
1315
1316         switch (fmt[1]) {
1317         case 'F':
1318                 separator = '-';
1319                 break;
1320
1321         case 'R':
1322                 reversed = true;
1323                 fallthrough;
1324
1325         default:
1326                 separator = ':';
1327                 break;
1328         }
1329
1330         for (i = 0; i < 6; i++) {
1331                 if (reversed)
1332                         p = hex_byte_pack(p, addr[5 - i]);
1333                 else
1334                         p = hex_byte_pack(p, addr[i]);
1335
1336                 if (fmt[0] == 'M' && i != 5)
1337                         *p++ = separator;
1338         }
1339         *p = '\0';
1340
1341         return string_nocheck(buf, end, mac_addr, spec);
1342 }
1343
1344 static noinline_for_stack
1345 char *ip4_string(char *p, const u8 *addr, const char *fmt)
1346 {
1347         int i;
1348         bool leading_zeros = (fmt[0] == 'i');
1349         int index;
1350         int step;
1351
1352         switch (fmt[2]) {
1353         case 'h':
1354 #ifdef __BIG_ENDIAN
1355                 index = 0;
1356                 step = 1;
1357 #else
1358                 index = 3;
1359                 step = -1;
1360 #endif
1361                 break;
1362         case 'l':
1363                 index = 3;
1364                 step = -1;
1365                 break;
1366         case 'n':
1367         case 'b':
1368         default:
1369                 index = 0;
1370                 step = 1;
1371                 break;
1372         }
1373         for (i = 0; i < 4; i++) {
1374                 char temp[4] __aligned(2);      /* hold each IP quad in reverse order */
1375                 int digits = put_dec_trunc8(temp, addr[index]) - temp;
1376                 if (leading_zeros) {
1377                         if (digits < 3)
1378                                 *p++ = '0';
1379                         if (digits < 2)
1380                                 *p++ = '0';
1381                 }
1382                 /* reverse the digits in the quad */
1383                 while (digits--)
1384                         *p++ = temp[digits];
1385                 if (i < 3)
1386                         *p++ = '.';
1387                 index += step;
1388         }
1389         *p = '\0';
1390
1391         return p;
1392 }
1393
1394 static noinline_for_stack
1395 char *ip6_compressed_string(char *p, const char *addr)
1396 {
1397         int i, j, range;
1398         unsigned char zerolength[8];
1399         int longest = 1;
1400         int colonpos = -1;
1401         u16 word;
1402         u8 hi, lo;
1403         bool needcolon = false;
1404         bool useIPv4;
1405         struct in6_addr in6;
1406
1407         memcpy(&in6, addr, sizeof(struct in6_addr));
1408
1409         useIPv4 = ipv6_addr_v4mapped(&in6) || ipv6_addr_is_isatap(&in6);
1410
1411         memset(zerolength, 0, sizeof(zerolength));
1412
1413         if (useIPv4)
1414                 range = 6;
1415         else
1416                 range = 8;
1417
1418         /* find position of longest 0 run */
1419         for (i = 0; i < range; i++) {
1420                 for (j = i; j < range; j++) {
1421                         if (in6.s6_addr16[j] != 0)
1422                                 break;
1423                         zerolength[i]++;
1424                 }
1425         }
1426         for (i = 0; i < range; i++) {
1427                 if (zerolength[i] > longest) {
1428                         longest = zerolength[i];
1429                         colonpos = i;
1430                 }
1431         }
1432         if (longest == 1)               /* don't compress a single 0 */
1433                 colonpos = -1;
1434
1435         /* emit address */
1436         for (i = 0; i < range; i++) {
1437                 if (i == colonpos) {
1438                         if (needcolon || i == 0)
1439                                 *p++ = ':';
1440                         *p++ = ':';
1441                         needcolon = false;
1442                         i += longest - 1;
1443                         continue;
1444                 }
1445                 if (needcolon) {
1446                         *p++ = ':';
1447                         needcolon = false;
1448                 }
1449                 /* hex u16 without leading 0s */
1450                 word = ntohs(in6.s6_addr16[i]);
1451                 hi = word >> 8;
1452                 lo = word & 0xff;
1453                 if (hi) {
1454                         if (hi > 0x0f)
1455                                 p = hex_byte_pack(p, hi);
1456                         else
1457                                 *p++ = hex_asc_lo(hi);
1458                         p = hex_byte_pack(p, lo);
1459                 }
1460                 else if (lo > 0x0f)
1461                         p = hex_byte_pack(p, lo);
1462                 else
1463                         *p++ = hex_asc_lo(lo);
1464                 needcolon = true;
1465         }
1466
1467         if (useIPv4) {
1468                 if (needcolon)
1469                         *p++ = ':';
1470                 p = ip4_string(p, &in6.s6_addr[12], "I4");
1471         }
1472         *p = '\0';
1473
1474         return p;
1475 }
1476
1477 static noinline_for_stack
1478 char *ip6_string(char *p, const char *addr, const char *fmt)
1479 {
1480         int i;
1481
1482         for (i = 0; i < 8; i++) {
1483                 p = hex_byte_pack(p, *addr++);
1484                 p = hex_byte_pack(p, *addr++);
1485                 if (fmt[0] == 'I' && i != 7)
1486                         *p++ = ':';
1487         }
1488         *p = '\0';
1489
1490         return p;
1491 }
1492
1493 static noinline_for_stack
1494 char *ip6_addr_string(char *buf, char *end, const u8 *addr,
1495                       struct printf_spec spec, const char *fmt)
1496 {
1497         char ip6_addr[sizeof("xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255")];
1498
1499         if (fmt[0] == 'I' && fmt[2] == 'c')
1500                 ip6_compressed_string(ip6_addr, addr);
1501         else
1502                 ip6_string(ip6_addr, addr, fmt);
1503
1504         return string_nocheck(buf, end, ip6_addr, spec);
1505 }
1506
1507 static noinline_for_stack
1508 char *ip4_addr_string(char *buf, char *end, const u8 *addr,
1509                       struct printf_spec spec, const char *fmt)
1510 {
1511         char ip4_addr[sizeof("255.255.255.255")];
1512
1513         ip4_string(ip4_addr, addr, fmt);
1514
1515         return string_nocheck(buf, end, ip4_addr, spec);
1516 }
1517
1518 static noinline_for_stack
1519 char *ip6_addr_string_sa(char *buf, char *end, const struct sockaddr_in6 *sa,
1520                          struct printf_spec spec, const char *fmt)
1521 {
1522         bool have_p = false, have_s = false, have_f = false, have_c = false;
1523         char ip6_addr[sizeof("[xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255]") +
1524                       sizeof(":12345") + sizeof("/123456789") +
1525                       sizeof("%1234567890")];
1526         char *p = ip6_addr, *pend = ip6_addr + sizeof(ip6_addr);
1527         const u8 *addr = (const u8 *) &sa->sin6_addr;
1528         char fmt6[2] = { fmt[0], '6' };
1529         u8 off = 0;
1530
1531         fmt++;
1532         while (isalpha(*++fmt)) {
1533                 switch (*fmt) {
1534                 case 'p':
1535                         have_p = true;
1536                         break;
1537                 case 'f':
1538                         have_f = true;
1539                         break;
1540                 case 's':
1541                         have_s = true;
1542                         break;
1543                 case 'c':
1544                         have_c = true;
1545                         break;
1546                 }
1547         }
1548
1549         if (have_p || have_s || have_f) {
1550                 *p = '[';
1551                 off = 1;
1552         }
1553
1554         if (fmt6[0] == 'I' && have_c)
1555                 p = ip6_compressed_string(ip6_addr + off, addr);
1556         else
1557                 p = ip6_string(ip6_addr + off, addr, fmt6);
1558
1559         if (have_p || have_s || have_f)
1560                 *p++ = ']';
1561
1562         if (have_p) {
1563                 *p++ = ':';
1564                 p = number(p, pend, ntohs(sa->sin6_port), spec);
1565         }
1566         if (have_f) {
1567                 *p++ = '/';
1568                 p = number(p, pend, ntohl(sa->sin6_flowinfo &
1569                                           IPV6_FLOWINFO_MASK), spec);
1570         }
1571         if (have_s) {
1572                 *p++ = '%';
1573                 p = number(p, pend, sa->sin6_scope_id, spec);
1574         }
1575         *p = '\0';
1576
1577         return string_nocheck(buf, end, ip6_addr, spec);
1578 }
1579
1580 static noinline_for_stack
1581 char *ip4_addr_string_sa(char *buf, char *end, const struct sockaddr_in *sa,
1582                          struct printf_spec spec, const char *fmt)
1583 {
1584         bool have_p = false;
1585         char *p, ip4_addr[sizeof("255.255.255.255") + sizeof(":12345")];
1586         char *pend = ip4_addr + sizeof(ip4_addr);
1587         const u8 *addr = (const u8 *) &sa->sin_addr.s_addr;
1588         char fmt4[3] = { fmt[0], '4', 0 };
1589
1590         fmt++;
1591         while (isalpha(*++fmt)) {
1592                 switch (*fmt) {
1593                 case 'p':
1594                         have_p = true;
1595                         break;
1596                 case 'h':
1597                 case 'l':
1598                 case 'n':
1599                 case 'b':
1600                         fmt4[2] = *fmt;
1601                         break;
1602                 }
1603         }
1604
1605         p = ip4_string(ip4_addr, addr, fmt4);
1606         if (have_p) {
1607                 *p++ = ':';
1608                 p = number(p, pend, ntohs(sa->sin_port), spec);
1609         }
1610         *p = '\0';
1611
1612         return string_nocheck(buf, end, ip4_addr, spec);
1613 }
1614
1615 static noinline_for_stack
1616 char *ip_addr_string(char *buf, char *end, const void *ptr,
1617                      struct printf_spec spec, const char *fmt)
1618 {
1619         char *err_fmt_msg;
1620
1621         if (check_pointer(&buf, end, ptr, spec))
1622                 return buf;
1623
1624         switch (fmt[1]) {
1625         case '6':
1626                 return ip6_addr_string(buf, end, ptr, spec, fmt);
1627         case '4':
1628                 return ip4_addr_string(buf, end, ptr, spec, fmt);
1629         case 'S': {
1630                 const union {
1631                         struct sockaddr         raw;
1632                         struct sockaddr_in      v4;
1633                         struct sockaddr_in6     v6;
1634                 } *sa = ptr;
1635
1636                 switch (sa->raw.sa_family) {
1637                 case AF_INET:
1638                         return ip4_addr_string_sa(buf, end, &sa->v4, spec, fmt);
1639                 case AF_INET6:
1640                         return ip6_addr_string_sa(buf, end, &sa->v6, spec, fmt);
1641                 default:
1642                         return error_string(buf, end, "(einval)", spec);
1643                 }}
1644         }
1645
1646         err_fmt_msg = fmt[0] == 'i' ? "(%pi?)" : "(%pI?)";
1647         return error_string(buf, end, err_fmt_msg, spec);
1648 }
1649
1650 static noinline_for_stack
1651 char *escaped_string(char *buf, char *end, u8 *addr, struct printf_spec spec,
1652                      const char *fmt)
1653 {
1654         bool found = true;
1655         int count = 1;
1656         unsigned int flags = 0;
1657         int len;
1658
1659         if (spec.field_width == 0)
1660                 return buf;                             /* nothing to print */
1661
1662         if (check_pointer(&buf, end, addr, spec))
1663                 return buf;
1664
1665         do {
1666                 switch (fmt[count++]) {
1667                 case 'a':
1668                         flags |= ESCAPE_ANY;
1669                         break;
1670                 case 'c':
1671                         flags |= ESCAPE_SPECIAL;
1672                         break;
1673                 case 'h':
1674                         flags |= ESCAPE_HEX;
1675                         break;
1676                 case 'n':
1677                         flags |= ESCAPE_NULL;
1678                         break;
1679                 case 'o':
1680                         flags |= ESCAPE_OCTAL;
1681                         break;
1682                 case 'p':
1683                         flags |= ESCAPE_NP;
1684                         break;
1685                 case 's':
1686                         flags |= ESCAPE_SPACE;
1687                         break;
1688                 default:
1689                         found = false;
1690                         break;
1691                 }
1692         } while (found);
1693
1694         if (!flags)
1695                 flags = ESCAPE_ANY_NP;
1696
1697         len = spec.field_width < 0 ? 1 : spec.field_width;
1698
1699         /*
1700          * string_escape_mem() writes as many characters as it can to
1701          * the given buffer, and returns the total size of the output
1702          * had the buffer been big enough.
1703          */
1704         buf += string_escape_mem(addr, len, buf, buf < end ? end - buf : 0, flags, NULL);
1705
1706         return buf;
1707 }
1708
1709 static char *va_format(char *buf, char *end, struct va_format *va_fmt,
1710                        struct printf_spec spec, const char *fmt)
1711 {
1712         va_list va;
1713
1714         if (check_pointer(&buf, end, va_fmt, spec))
1715                 return buf;
1716
1717         va_copy(va, *va_fmt->va);
1718         buf += vsnprintf(buf, end > buf ? end - buf : 0, va_fmt->fmt, va);
1719         va_end(va);
1720
1721         return buf;
1722 }
1723
1724 static noinline_for_stack
1725 char *uuid_string(char *buf, char *end, const u8 *addr,
1726                   struct printf_spec spec, const char *fmt)
1727 {
1728         char uuid[UUID_STRING_LEN + 1];
1729         char *p = uuid;
1730         int i;
1731         const u8 *index = uuid_index;
1732         bool uc = false;
1733
1734         if (check_pointer(&buf, end, addr, spec))
1735                 return buf;
1736
1737         switch (*(++fmt)) {
1738         case 'L':
1739                 uc = true;
1740                 fallthrough;
1741         case 'l':
1742                 index = guid_index;
1743                 break;
1744         case 'B':
1745                 uc = true;
1746                 break;
1747         }
1748
1749         for (i = 0; i < 16; i++) {
1750                 if (uc)
1751                         p = hex_byte_pack_upper(p, addr[index[i]]);
1752                 else
1753                         p = hex_byte_pack(p, addr[index[i]]);
1754                 switch (i) {
1755                 case 3:
1756                 case 5:
1757                 case 7:
1758                 case 9:
1759                         *p++ = '-';
1760                         break;
1761                 }
1762         }
1763
1764         *p = 0;
1765
1766         return string_nocheck(buf, end, uuid, spec);
1767 }
1768
1769 static noinline_for_stack
1770 char *netdev_bits(char *buf, char *end, const void *addr,
1771                   struct printf_spec spec,  const char *fmt)
1772 {
1773         unsigned long long num;
1774         int size;
1775
1776         if (check_pointer(&buf, end, addr, spec))
1777                 return buf;
1778
1779         switch (fmt[1]) {
1780         case 'F':
1781                 num = *(const netdev_features_t *)addr;
1782                 size = sizeof(netdev_features_t);
1783                 break;
1784         default:
1785                 return error_string(buf, end, "(%pN?)", spec);
1786         }
1787
1788         return special_hex_number(buf, end, num, size);
1789 }
1790
1791 static noinline_for_stack
1792 char *fourcc_string(char *buf, char *end, const u32 *fourcc,
1793                     struct printf_spec spec, const char *fmt)
1794 {
1795         char output[sizeof("0123 little-endian (0x01234567)")];
1796         char *p = output;
1797         unsigned int i;
1798         u32 orig, val;
1799
1800         if (fmt[1] != 'c' || fmt[2] != 'c')
1801                 return error_string(buf, end, "(%p4?)", spec);
1802
1803         if (check_pointer(&buf, end, fourcc, spec))
1804                 return buf;
1805
1806         orig = get_unaligned(fourcc);
1807         val = orig & ~BIT(31);
1808
1809         for (i = 0; i < sizeof(u32); i++) {
1810                 unsigned char c = val >> (i * 8);
1811
1812                 /* Print non-control ASCII characters as-is, dot otherwise */
1813                 *p++ = isascii(c) && isprint(c) ? c : '.';
1814         }
1815
1816         *p++ = ' ';
1817         strcpy(p, orig & BIT(31) ? "big-endian" : "little-endian");
1818         p += strlen(p);
1819
1820         *p++ = ' ';
1821         *p++ = '(';
1822         p = special_hex_number(p, output + sizeof(output) - 2, orig, sizeof(u32));
1823         *p++ = ')';
1824         *p = '\0';
1825
1826         return string(buf, end, output, spec);
1827 }
1828
1829 static noinline_for_stack
1830 char *address_val(char *buf, char *end, const void *addr,
1831                   struct printf_spec spec, const char *fmt)
1832 {
1833         unsigned long long num;
1834         int size;
1835
1836         if (check_pointer(&buf, end, addr, spec))
1837                 return buf;
1838
1839         switch (fmt[1]) {
1840         case 'd':
1841                 num = *(const dma_addr_t *)addr;
1842                 size = sizeof(dma_addr_t);
1843                 break;
1844         case 'p':
1845         default:
1846                 num = *(const phys_addr_t *)addr;
1847                 size = sizeof(phys_addr_t);
1848                 break;
1849         }
1850
1851         return special_hex_number(buf, end, num, size);
1852 }
1853
1854 static noinline_for_stack
1855 char *date_str(char *buf, char *end, const struct rtc_time *tm, bool r)
1856 {
1857         int year = tm->tm_year + (r ? 0 : 1900);
1858         int mon = tm->tm_mon + (r ? 0 : 1);
1859
1860         buf = number(buf, end, year, default_dec04_spec);
1861         if (buf < end)
1862                 *buf = '-';
1863         buf++;
1864
1865         buf = number(buf, end, mon, default_dec02_spec);
1866         if (buf < end)
1867                 *buf = '-';
1868         buf++;
1869
1870         return number(buf, end, tm->tm_mday, default_dec02_spec);
1871 }
1872
1873 static noinline_for_stack
1874 char *time_str(char *buf, char *end, const struct rtc_time *tm, bool r)
1875 {
1876         buf = number(buf, end, tm->tm_hour, default_dec02_spec);
1877         if (buf < end)
1878                 *buf = ':';
1879         buf++;
1880
1881         buf = number(buf, end, tm->tm_min, default_dec02_spec);
1882         if (buf < end)
1883                 *buf = ':';
1884         buf++;
1885
1886         return number(buf, end, tm->tm_sec, default_dec02_spec);
1887 }
1888
1889 static noinline_for_stack
1890 char *rtc_str(char *buf, char *end, const struct rtc_time *tm,
1891               struct printf_spec spec, const char *fmt)
1892 {
1893         bool have_t = true, have_d = true;
1894         bool raw = false, iso8601_separator = true;
1895         bool found = true;
1896         int count = 2;
1897
1898         if (check_pointer(&buf, end, tm, spec))
1899                 return buf;
1900
1901         switch (fmt[count]) {
1902         case 'd':
1903                 have_t = false;
1904                 count++;
1905                 break;
1906         case 't':
1907                 have_d = false;
1908                 count++;
1909                 break;
1910         }
1911
1912         do {
1913                 switch (fmt[count++]) {
1914                 case 'r':
1915                         raw = true;
1916                         break;
1917                 case 's':
1918                         iso8601_separator = false;
1919                         break;
1920                 default:
1921                         found = false;
1922                         break;
1923                 }
1924         } while (found);
1925
1926         if (have_d)
1927                 buf = date_str(buf, end, tm, raw);
1928         if (have_d && have_t) {
1929                 if (buf < end)
1930                         *buf = iso8601_separator ? 'T' : ' ';
1931                 buf++;
1932         }
1933         if (have_t)
1934                 buf = time_str(buf, end, tm, raw);
1935
1936         return buf;
1937 }
1938
1939 static noinline_for_stack
1940 char *time64_str(char *buf, char *end, const time64_t time,
1941                  struct printf_spec spec, const char *fmt)
1942 {
1943         struct rtc_time rtc_time;
1944         struct tm tm;
1945
1946         time64_to_tm(time, 0, &tm);
1947
1948         rtc_time.tm_sec = tm.tm_sec;
1949         rtc_time.tm_min = tm.tm_min;
1950         rtc_time.tm_hour = tm.tm_hour;
1951         rtc_time.tm_mday = tm.tm_mday;
1952         rtc_time.tm_mon = tm.tm_mon;
1953         rtc_time.tm_year = tm.tm_year;
1954         rtc_time.tm_wday = tm.tm_wday;
1955         rtc_time.tm_yday = tm.tm_yday;
1956
1957         rtc_time.tm_isdst = 0;
1958
1959         return rtc_str(buf, end, &rtc_time, spec, fmt);
1960 }
1961
1962 static noinline_for_stack
1963 char *time_and_date(char *buf, char *end, void *ptr, struct printf_spec spec,
1964                     const char *fmt)
1965 {
1966         switch (fmt[1]) {
1967         case 'R':
1968                 return rtc_str(buf, end, (const struct rtc_time *)ptr, spec, fmt);
1969         case 'T':
1970                 return time64_str(buf, end, *(const time64_t *)ptr, spec, fmt);
1971         default:
1972                 return error_string(buf, end, "(%pt?)", spec);
1973         }
1974 }
1975
1976 static noinline_for_stack
1977 char *clock(char *buf, char *end, struct clk *clk, struct printf_spec spec,
1978             const char *fmt)
1979 {
1980         if (!IS_ENABLED(CONFIG_HAVE_CLK))
1981                 return error_string(buf, end, "(%pC?)", spec);
1982
1983         if (check_pointer(&buf, end, clk, spec))
1984                 return buf;
1985
1986         switch (fmt[1]) {
1987         case 'n':
1988         default:
1989 #ifdef CONFIG_COMMON_CLK
1990                 return string(buf, end, __clk_get_name(clk), spec);
1991 #else
1992                 return ptr_to_id(buf, end, clk, spec);
1993 #endif
1994         }
1995 }
1996
1997 static
1998 char *format_flags(char *buf, char *end, unsigned long flags,
1999                                         const struct trace_print_flags *names)
2000 {
2001         unsigned long mask;
2002
2003         for ( ; flags && names->name; names++) {
2004                 mask = names->mask;
2005                 if ((flags & mask) != mask)
2006                         continue;
2007
2008                 buf = string(buf, end, names->name, default_str_spec);
2009
2010                 flags &= ~mask;
2011                 if (flags) {
2012                         if (buf < end)
2013                                 *buf = '|';
2014                         buf++;
2015                 }
2016         }
2017
2018         if (flags)
2019                 buf = number(buf, end, flags, default_flag_spec);
2020
2021         return buf;
2022 }
2023
2024 struct page_flags_fields {
2025         int width;
2026         int shift;
2027         int mask;
2028         const struct printf_spec *spec;
2029         const char *name;
2030 };
2031
2032 static const struct page_flags_fields pff[] = {
2033         {SECTIONS_WIDTH, SECTIONS_PGSHIFT, SECTIONS_MASK,
2034          &default_dec_spec, "section"},
2035         {NODES_WIDTH, NODES_PGSHIFT, NODES_MASK,
2036          &default_dec_spec, "node"},
2037         {ZONES_WIDTH, ZONES_PGSHIFT, ZONES_MASK,
2038          &default_dec_spec, "zone"},
2039         {LAST_CPUPID_WIDTH, LAST_CPUPID_PGSHIFT, LAST_CPUPID_MASK,
2040          &default_flag_spec, "lastcpupid"},
2041         {KASAN_TAG_WIDTH, KASAN_TAG_PGSHIFT, KASAN_TAG_MASK,
2042          &default_flag_spec, "kasantag"},
2043 };
2044
2045 static
2046 char *format_page_flags(char *buf, char *end, unsigned long flags)
2047 {
2048         unsigned long main_flags = flags & PAGEFLAGS_MASK;
2049         bool append = false;
2050         int i;
2051
2052         buf = number(buf, end, flags, default_flag_spec);
2053         if (buf < end)
2054                 *buf = '(';
2055         buf++;
2056
2057         /* Page flags from the main area. */
2058         if (main_flags) {
2059                 buf = format_flags(buf, end, main_flags, pageflag_names);
2060                 append = true;
2061         }
2062
2063         /* Page flags from the fields area */
2064         for (i = 0; i < ARRAY_SIZE(pff); i++) {
2065                 /* Skip undefined fields. */
2066                 if (!pff[i].width)
2067                         continue;
2068
2069                 /* Format: Flag Name + '=' (equals sign) + Number + '|' (separator) */
2070                 if (append) {
2071                         if (buf < end)
2072                                 *buf = '|';
2073                         buf++;
2074                 }
2075
2076                 buf = string(buf, end, pff[i].name, default_str_spec);
2077                 if (buf < end)
2078                         *buf = '=';
2079                 buf++;
2080                 buf = number(buf, end, (flags >> pff[i].shift) & pff[i].mask,
2081                              *pff[i].spec);
2082
2083                 append = true;
2084         }
2085         if (buf < end)
2086                 *buf = ')';
2087         buf++;
2088
2089         return buf;
2090 }
2091
2092 static noinline_for_stack
2093 char *flags_string(char *buf, char *end, void *flags_ptr,
2094                    struct printf_spec spec, const char *fmt)
2095 {
2096         unsigned long flags;
2097         const struct trace_print_flags *names;
2098
2099         if (check_pointer(&buf, end, flags_ptr, spec))
2100                 return buf;
2101
2102         switch (fmt[1]) {
2103         case 'p':
2104                 return format_page_flags(buf, end, *(unsigned long *)flags_ptr);
2105         case 'v':
2106                 flags = *(unsigned long *)flags_ptr;
2107                 names = vmaflag_names;
2108                 break;
2109         case 'g':
2110                 flags = (__force unsigned long)(*(gfp_t *)flags_ptr);
2111                 names = gfpflag_names;
2112                 break;
2113         default:
2114                 return error_string(buf, end, "(%pG?)", spec);
2115         }
2116
2117         return format_flags(buf, end, flags, names);
2118 }
2119
2120 static noinline_for_stack
2121 char *fwnode_full_name_string(struct fwnode_handle *fwnode, char *buf,
2122                               char *end)
2123 {
2124         int depth;
2125
2126         /* Loop starting from the root node to the current node. */
2127         for (depth = fwnode_count_parents(fwnode); depth >= 0; depth--) {
2128                 /*
2129                  * Only get a reference for other nodes (i.e. parent nodes).
2130                  * fwnode refcount may be 0 here.
2131                  */
2132                 struct fwnode_handle *__fwnode = depth ?
2133                         fwnode_get_nth_parent(fwnode, depth) : fwnode;
2134
2135                 buf = string(buf, end, fwnode_get_name_prefix(__fwnode),
2136                              default_str_spec);
2137                 buf = string(buf, end, fwnode_get_name(__fwnode),
2138                              default_str_spec);
2139
2140                 if (depth)
2141                         fwnode_handle_put(__fwnode);
2142         }
2143
2144         return buf;
2145 }
2146
2147 static noinline_for_stack
2148 char *device_node_string(char *buf, char *end, struct device_node *dn,
2149                          struct printf_spec spec, const char *fmt)
2150 {
2151         char tbuf[sizeof("xxxx") + 1];
2152         const char *p;
2153         int ret;
2154         char *buf_start = buf;
2155         struct property *prop;
2156         bool has_mult, pass;
2157
2158         struct printf_spec str_spec = spec;
2159         str_spec.field_width = -1;
2160
2161         if (fmt[0] != 'F')
2162                 return error_string(buf, end, "(%pO?)", spec);
2163
2164         if (!IS_ENABLED(CONFIG_OF))
2165                 return error_string(buf, end, "(%pOF?)", spec);
2166
2167         if (check_pointer(&buf, end, dn, spec))
2168                 return buf;
2169
2170         /* simple case without anything any more format specifiers */
2171         fmt++;
2172         if (fmt[0] == '\0' || strcspn(fmt,"fnpPFcC") > 0)
2173                 fmt = "f";
2174
2175         for (pass = false; strspn(fmt,"fnpPFcC"); fmt++, pass = true) {
2176                 int precision;
2177                 if (pass) {
2178                         if (buf < end)
2179                                 *buf = ':';
2180                         buf++;
2181                 }
2182
2183                 switch (*fmt) {
2184                 case 'f':       /* full_name */
2185                         buf = fwnode_full_name_string(of_fwnode_handle(dn), buf,
2186                                                       end);
2187                         break;
2188                 case 'n':       /* name */
2189                         p = fwnode_get_name(of_fwnode_handle(dn));
2190                         precision = str_spec.precision;
2191                         str_spec.precision = strchrnul(p, '@') - p;
2192                         buf = string(buf, end, p, str_spec);
2193                         str_spec.precision = precision;
2194                         break;
2195                 case 'p':       /* phandle */
2196                         buf = number(buf, end, (unsigned int)dn->phandle, default_dec_spec);
2197                         break;
2198                 case 'P':       /* path-spec */
2199                         p = fwnode_get_name(of_fwnode_handle(dn));
2200                         if (!p[1])
2201                                 p = "/";
2202                         buf = string(buf, end, p, str_spec);
2203                         break;
2204                 case 'F':       /* flags */
2205                         tbuf[0] = of_node_check_flag(dn, OF_DYNAMIC) ? 'D' : '-';
2206                         tbuf[1] = of_node_check_flag(dn, OF_DETACHED) ? 'd' : '-';
2207                         tbuf[2] = of_node_check_flag(dn, OF_POPULATED) ? 'P' : '-';
2208                         tbuf[3] = of_node_check_flag(dn, OF_POPULATED_BUS) ? 'B' : '-';
2209                         tbuf[4] = 0;
2210                         buf = string_nocheck(buf, end, tbuf, str_spec);
2211                         break;
2212                 case 'c':       /* major compatible string */
2213                         ret = of_property_read_string(dn, "compatible", &p);
2214                         if (!ret)
2215                                 buf = string(buf, end, p, str_spec);
2216                         break;
2217                 case 'C':       /* full compatible string */
2218                         has_mult = false;
2219                         of_property_for_each_string(dn, "compatible", prop, p) {
2220                                 if (has_mult)
2221                                         buf = string_nocheck(buf, end, ",", str_spec);
2222                                 buf = string_nocheck(buf, end, "\"", str_spec);
2223                                 buf = string(buf, end, p, str_spec);
2224                                 buf = string_nocheck(buf, end, "\"", str_spec);
2225
2226                                 has_mult = true;
2227                         }
2228                         break;
2229                 default:
2230                         break;
2231                 }
2232         }
2233
2234         return widen_string(buf, buf - buf_start, end, spec);
2235 }
2236
2237 static noinline_for_stack
2238 char *fwnode_string(char *buf, char *end, struct fwnode_handle *fwnode,
2239                     struct printf_spec spec, const char *fmt)
2240 {
2241         struct printf_spec str_spec = spec;
2242         char *buf_start = buf;
2243
2244         str_spec.field_width = -1;
2245
2246         if (*fmt != 'w')
2247                 return error_string(buf, end, "(%pf?)", spec);
2248
2249         if (check_pointer(&buf, end, fwnode, spec))
2250                 return buf;
2251
2252         fmt++;
2253
2254         switch (*fmt) {
2255         case 'P':       /* name */
2256                 buf = string(buf, end, fwnode_get_name(fwnode), str_spec);
2257                 break;
2258         case 'f':       /* full_name */
2259         default:
2260                 buf = fwnode_full_name_string(fwnode, buf, end);
2261                 break;
2262         }
2263
2264         return widen_string(buf, buf - buf_start, end, spec);
2265 }
2266
2267 static noinline_for_stack
2268 char *resource_or_range(const char *fmt, char *buf, char *end, void *ptr,
2269                         struct printf_spec spec)
2270 {
2271         if (*fmt == 'r' && fmt[1] == 'a')
2272                 return range_string(buf, end, ptr, spec, fmt);
2273         return resource_string(buf, end, ptr, spec, fmt);
2274 }
2275
2276 int __init no_hash_pointers_enable(char *str)
2277 {
2278         if (no_hash_pointers)
2279                 return 0;
2280
2281         no_hash_pointers = true;
2282
2283         pr_warn("**********************************************************\n");
2284         pr_warn("**   NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE   **\n");
2285         pr_warn("**                                                      **\n");
2286         pr_warn("** This system shows unhashed kernel memory addresses   **\n");
2287         pr_warn("** via the console, logs, and other interfaces. This    **\n");
2288         pr_warn("** might reduce the security of your system.            **\n");
2289         pr_warn("**                                                      **\n");
2290         pr_warn("** If you see this message and you are not debugging    **\n");
2291         pr_warn("** the kernel, report this immediately to your system   **\n");
2292         pr_warn("** administrator!                                       **\n");
2293         pr_warn("**                                                      **\n");
2294         pr_warn("**   NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE   **\n");
2295         pr_warn("**********************************************************\n");
2296
2297         return 0;
2298 }
2299 early_param("no_hash_pointers", no_hash_pointers_enable);
2300
2301 /* Used for Rust formatting ('%pA'). */
2302 char *rust_fmt_argument(char *buf, char *end, void *ptr);
2303
2304 /*
2305  * Show a '%p' thing.  A kernel extension is that the '%p' is followed
2306  * by an extra set of alphanumeric characters that are extended format
2307  * specifiers.
2308  *
2309  * Please update scripts/checkpatch.pl when adding/removing conversion
2310  * characters.  (Search for "check for vsprintf extension").
2311  *
2312  * Right now we handle:
2313  *
2314  * - 'S' For symbolic direct pointers (or function descriptors) with offset
2315  * - 's' For symbolic direct pointers (or function descriptors) without offset
2316  * - '[Ss]R' as above with __builtin_extract_return_addr() translation
2317  * - 'S[R]b' as above with module build ID (for use in backtraces)
2318  * - '[Ff]' %pf and %pF were obsoleted and later removed in favor of
2319  *          %ps and %pS. Be careful when re-using these specifiers.
2320  * - 'B' For backtraced symbolic direct pointers with offset
2321  * - 'Bb' as above with module build ID (for use in backtraces)
2322  * - 'R' For decoded struct resource, e.g., [mem 0x0-0x1f 64bit pref]
2323  * - 'r' For raw struct resource, e.g., [mem 0x0-0x1f flags 0x201]
2324  * - 'ra' For struct ranges, e.g., [range 0x0000000000000000 - 0x00000000000000ff]
2325  * - 'b[l]' For a bitmap, the number of bits is determined by the field
2326  *       width which must be explicitly specified either as part of the
2327  *       format string '%32b[l]' or through '%*b[l]', [l] selects
2328  *       range-list format instead of hex format
2329  * - 'M' For a 6-byte MAC address, it prints the address in the
2330  *       usual colon-separated hex notation
2331  * - 'm' For a 6-byte MAC address, it prints the hex address without colons
2332  * - 'MF' For a 6-byte MAC FDDI address, it prints the address
2333  *       with a dash-separated hex notation
2334  * - '[mM]R' For a 6-byte MAC address, Reverse order (Bluetooth)
2335  * - 'I' [46] for IPv4/IPv6 addresses printed in the usual way
2336  *       IPv4 uses dot-separated decimal without leading 0's (1.2.3.4)
2337  *       IPv6 uses colon separated network-order 16 bit hex with leading 0's
2338  *       [S][pfs]
2339  *       Generic IPv4/IPv6 address (struct sockaddr *) that falls back to
2340  *       [4] or [6] and is able to print port [p], flowinfo [f], scope [s]
2341  * - 'i' [46] for 'raw' IPv4/IPv6 addresses
2342  *       IPv6 omits the colons (01020304...0f)
2343  *       IPv4 uses dot-separated decimal with leading 0's (010.123.045.006)
2344  *       [S][pfs]
2345  *       Generic IPv4/IPv6 address (struct sockaddr *) that falls back to
2346  *       [4] or [6] and is able to print port [p], flowinfo [f], scope [s]
2347  * - '[Ii][4S][hnbl]' IPv4 addresses in host, network, big or little endian order
2348  * - 'I[6S]c' for IPv6 addresses printed as specified by
2349  *       https://tools.ietf.org/html/rfc5952
2350  * - 'E[achnops]' For an escaped buffer, where rules are defined by combination
2351  *                of the following flags (see string_escape_mem() for the
2352  *                details):
2353  *                  a - ESCAPE_ANY
2354  *                  c - ESCAPE_SPECIAL
2355  *                  h - ESCAPE_HEX
2356  *                  n - ESCAPE_NULL
2357  *                  o - ESCAPE_OCTAL
2358  *                  p - ESCAPE_NP
2359  *                  s - ESCAPE_SPACE
2360  *                By default ESCAPE_ANY_NP is used.
2361  * - 'U' For a 16 byte UUID/GUID, it prints the UUID/GUID in the form
2362  *       "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx"
2363  *       Options for %pU are:
2364  *         b big endian lower case hex (default)
2365  *         B big endian UPPER case hex
2366  *         l little endian lower case hex
2367  *         L little endian UPPER case hex
2368  *           big endian output byte order is:
2369  *             [0][1][2][3]-[4][5]-[6][7]-[8][9]-[10][11][12][13][14][15]
2370  *           little endian output byte order is:
2371  *             [3][2][1][0]-[5][4]-[7][6]-[8][9]-[10][11][12][13][14][15]
2372  * - 'V' For a struct va_format which contains a format string * and va_list *,
2373  *       call vsnprintf(->format, *->va_list).
2374  *       Implements a "recursive vsnprintf".
2375  *       Do not use this feature without some mechanism to verify the
2376  *       correctness of the format string and va_list arguments.
2377  * - 'K' For a kernel pointer that should be hidden from unprivileged users.
2378  *       Use only for procfs, sysfs and similar files, not printk(); please
2379  *       read the documentation (path below) first.
2380  * - 'NF' For a netdev_features_t
2381  * - '4cc' V4L2 or DRM FourCC code, with endianness and raw numerical value.
2382  * - 'h[CDN]' For a variable-length buffer, it prints it as a hex string with
2383  *            a certain separator (' ' by default):
2384  *              C colon
2385  *              D dash
2386  *              N no separator
2387  *            The maximum supported length is 64 bytes of the input. Consider
2388  *            to use print_hex_dump() for the larger input.
2389  * - 'a[pd]' For address types [p] phys_addr_t, [d] dma_addr_t and derivatives
2390  *           (default assumed to be phys_addr_t, passed by reference)
2391  * - 'd[234]' For a dentry name (optionally 2-4 last components)
2392  * - 'D[234]' Same as 'd' but for a struct file
2393  * - 'g' For block_device name (gendisk + partition number)
2394  * - 't[RT][dt][r][s]' For time and date as represented by:
2395  *      R    struct rtc_time
2396  *      T    time64_t
2397  * - 'C' For a clock, it prints the name (Common Clock Framework) or address
2398  *       (legacy clock framework) of the clock
2399  * - 'Cn' For a clock, it prints the name (Common Clock Framework) or address
2400  *        (legacy clock framework) of the clock
2401  * - 'G' For flags to be printed as a collection of symbolic strings that would
2402  *       construct the specific value. Supported flags given by option:
2403  *       p page flags (see struct page) given as pointer to unsigned long
2404  *       g gfp flags (GFP_* and __GFP_*) given as pointer to gfp_t
2405  *       v vma flags (VM_*) given as pointer to unsigned long
2406  * - 'OF[fnpPcCF]'  For a device tree object
2407  *                  Without any optional arguments prints the full_name
2408  *                  f device node full_name
2409  *                  n device node name
2410  *                  p device node phandle
2411  *                  P device node path spec (name + @unit)
2412  *                  F device node flags
2413  *                  c major compatible string
2414  *                  C full compatible string
2415  * - 'fw[fP]'   For a firmware node (struct fwnode_handle) pointer
2416  *              Without an option prints the full name of the node
2417  *              f full name
2418  *              P node name, including a possible unit address
2419  * - 'x' For printing the address unmodified. Equivalent to "%lx".
2420  *       Please read the documentation (path below) before using!
2421  * - '[ku]s' For a BPF/tracing related format specifier, e.g. used out of
2422  *           bpf_trace_printk() where [ku] prefix specifies either kernel (k)
2423  *           or user (u) memory to probe, and:
2424  *              s a string, equivalent to "%s" on direct vsnprintf() use
2425  *
2426  * ** When making changes please also update:
2427  *      Documentation/core-api/printk-formats.rst
2428  *
2429  * Note: The default behaviour (unadorned %p) is to hash the address,
2430  * rendering it useful as a unique identifier.
2431  *
2432  * There is also a '%pA' format specifier, but it is only intended to be used
2433  * from Rust code to format core::fmt::Arguments. Do *not* use it from C.
2434  * See rust/kernel/print.rs for details.
2435  */
2436 static noinline_for_stack
2437 char *pointer(const char *fmt, char *buf, char *end, void *ptr,
2438               struct printf_spec spec)
2439 {
2440         switch (*fmt) {
2441         case 'S':
2442         case 's':
2443                 ptr = dereference_symbol_descriptor(ptr);
2444                 fallthrough;
2445         case 'B':
2446                 return symbol_string(buf, end, ptr, spec, fmt);
2447         case 'R':
2448         case 'r':
2449                 return resource_or_range(fmt, buf, end, ptr, spec);
2450         case 'h':
2451                 return hex_string(buf, end, ptr, spec, fmt);
2452         case 'b':
2453                 switch (fmt[1]) {
2454                 case 'l':
2455                         return bitmap_list_string(buf, end, ptr, spec, fmt);
2456                 default:
2457                         return bitmap_string(buf, end, ptr, spec, fmt);
2458                 }
2459         case 'M':                       /* Colon separated: 00:01:02:03:04:05 */
2460         case 'm':                       /* Contiguous: 000102030405 */
2461                                         /* [mM]F (FDDI) */
2462                                         /* [mM]R (Reverse order; Bluetooth) */
2463                 return mac_address_string(buf, end, ptr, spec, fmt);
2464         case 'I':                       /* Formatted IP supported
2465                                          * 4:   1.2.3.4
2466                                          * 6:   0001:0203:...:0708
2467                                          * 6c:  1::708 or 1::1.2.3.4
2468                                          */
2469         case 'i':                       /* Contiguous:
2470                                          * 4:   001.002.003.004
2471                                          * 6:   000102...0f
2472                                          */
2473                 return ip_addr_string(buf, end, ptr, spec, fmt);
2474         case 'E':
2475                 return escaped_string(buf, end, ptr, spec, fmt);
2476         case 'U':
2477                 return uuid_string(buf, end, ptr, spec, fmt);
2478         case 'V':
2479                 return va_format(buf, end, ptr, spec, fmt);
2480         case 'K':
2481                 return restricted_pointer(buf, end, ptr, spec);
2482         case 'N':
2483                 return netdev_bits(buf, end, ptr, spec, fmt);
2484         case '4':
2485                 return fourcc_string(buf, end, ptr, spec, fmt);
2486         case 'a':
2487                 return address_val(buf, end, ptr, spec, fmt);
2488         case 'd':
2489                 return dentry_name(buf, end, ptr, spec, fmt);
2490         case 't':
2491                 return time_and_date(buf, end, ptr, spec, fmt);
2492         case 'C':
2493                 return clock(buf, end, ptr, spec, fmt);
2494         case 'D':
2495                 return file_dentry_name(buf, end, ptr, spec, fmt);
2496 #ifdef CONFIG_BLOCK
2497         case 'g':
2498                 return bdev_name(buf, end, ptr, spec, fmt);
2499 #endif
2500
2501         case 'G':
2502                 return flags_string(buf, end, ptr, spec, fmt);
2503         case 'O':
2504                 return device_node_string(buf, end, ptr, spec, fmt + 1);
2505         case 'f':
2506                 return fwnode_string(buf, end, ptr, spec, fmt + 1);
2507         case 'A':
2508                 if (!IS_ENABLED(CONFIG_RUST)) {
2509                         WARN_ONCE(1, "Please remove %%pA from non-Rust code\n");
2510                         return error_string(buf, end, "(%pA?)", spec);
2511                 }
2512                 return rust_fmt_argument(buf, end, ptr);
2513         case 'x':
2514                 return pointer_string(buf, end, ptr, spec);
2515         case 'e':
2516                 /* %pe with a non-ERR_PTR gets treated as plain %p */
2517                 if (!IS_ERR(ptr))
2518                         return default_pointer(buf, end, ptr, spec);
2519                 return err_ptr(buf, end, ptr, spec);
2520         case 'u':
2521         case 'k':
2522                 switch (fmt[1]) {
2523                 case 's':
2524                         return string(buf, end, ptr, spec);
2525                 default:
2526                         return error_string(buf, end, "(einval)", spec);
2527                 }
2528         default:
2529                 return default_pointer(buf, end, ptr, spec);
2530         }
2531 }
2532
2533 /*
2534  * Helper function to decode printf style format.
2535  * Each call decode a token from the format and return the
2536  * number of characters read (or likely the delta where it wants
2537  * to go on the next call).
2538  * The decoded token is returned through the parameters
2539  *
2540  * 'h', 'l', or 'L' for integer fields
2541  * 'z' support added 23/7/1999 S.H.
2542  * 'z' changed to 'Z' --davidm 1/25/99
2543  * 'Z' changed to 'z' --adobriyan 2017-01-25
2544  * 't' added for ptrdiff_t
2545  *
2546  * @fmt: the format string
2547  * @type of the token returned
2548  * @flags: various flags such as +, -, # tokens..
2549  * @field_width: overwritten width
2550  * @base: base of the number (octal, hex, ...)
2551  * @precision: precision of a number
2552  * @qualifier: qualifier of a number (long, size_t, ...)
2553  */
2554 static noinline_for_stack
2555 int format_decode(const char *fmt, struct printf_spec *spec)
2556 {
2557         const char *start = fmt;
2558         char qualifier;
2559
2560         /* we finished early by reading the field width */
2561         if (spec->type == FORMAT_TYPE_WIDTH) {
2562                 if (spec->field_width < 0) {
2563                         spec->field_width = -spec->field_width;
2564                         spec->flags |= LEFT;
2565                 }
2566                 spec->type = FORMAT_TYPE_NONE;
2567                 goto precision;
2568         }
2569
2570         /* we finished early by reading the precision */
2571         if (spec->type == FORMAT_TYPE_PRECISION) {
2572                 if (spec->precision < 0)
2573                         spec->precision = 0;
2574
2575                 spec->type = FORMAT_TYPE_NONE;
2576                 goto qualifier;
2577         }
2578
2579         /* By default */
2580         spec->type = FORMAT_TYPE_NONE;
2581
2582         for (; *fmt ; ++fmt) {
2583                 if (*fmt == '%')
2584                         break;
2585         }
2586
2587         /* Return the current non-format string */
2588         if (fmt != start || !*fmt)
2589                 return fmt - start;
2590
2591         /* Process flags */
2592         spec->flags = 0;
2593
2594         while (1) { /* this also skips first '%' */
2595                 bool found = true;
2596
2597                 ++fmt;
2598
2599                 switch (*fmt) {
2600                 case '-': spec->flags |= LEFT;    break;
2601                 case '+': spec->flags |= PLUS;    break;
2602                 case ' ': spec->flags |= SPACE;   break;
2603                 case '#': spec->flags |= SPECIAL; break;
2604                 case '0': spec->flags |= ZEROPAD; break;
2605                 default:  found = false;
2606                 }
2607
2608                 if (!found)
2609                         break;
2610         }
2611
2612         /* get field width */
2613         spec->field_width = -1;
2614
2615         if (isdigit(*fmt))
2616                 spec->field_width = skip_atoi(&fmt);
2617         else if (*fmt == '*') {
2618                 /* it's the next argument */
2619                 spec->type = FORMAT_TYPE_WIDTH;
2620                 return ++fmt - start;
2621         }
2622
2623 precision:
2624         /* get the precision */
2625         spec->precision = -1;
2626         if (*fmt == '.') {
2627                 ++fmt;
2628                 if (isdigit(*fmt)) {
2629                         spec->precision = skip_atoi(&fmt);
2630                         if (spec->precision < 0)
2631                                 spec->precision = 0;
2632                 } else if (*fmt == '*') {
2633                         /* it's the next argument */
2634                         spec->type = FORMAT_TYPE_PRECISION;
2635                         return ++fmt - start;
2636                 }
2637         }
2638
2639 qualifier:
2640         /* get the conversion qualifier */
2641         qualifier = 0;
2642         if (*fmt == 'h' || _tolower(*fmt) == 'l' ||
2643             *fmt == 'z' || *fmt == 't') {
2644                 qualifier = *fmt++;
2645                 if (unlikely(qualifier == *fmt)) {
2646                         if (qualifier == 'l') {
2647                                 qualifier = 'L';
2648                                 ++fmt;
2649                         } else if (qualifier == 'h') {
2650                                 qualifier = 'H';
2651                                 ++fmt;
2652                         }
2653                 }
2654         }
2655
2656         /* default base */
2657         spec->base = 10;
2658         switch (*fmt) {
2659         case 'c':
2660                 spec->type = FORMAT_TYPE_CHAR;
2661                 return ++fmt - start;
2662
2663         case 's':
2664                 spec->type = FORMAT_TYPE_STR;
2665                 return ++fmt - start;
2666
2667         case 'p':
2668                 spec->type = FORMAT_TYPE_PTR;
2669                 return ++fmt - start;
2670
2671         case '%':
2672                 spec->type = FORMAT_TYPE_PERCENT_CHAR;
2673                 return ++fmt - start;
2674
2675         /* integer number formats - set up the flags and "break" */
2676         case 'o':
2677                 spec->base = 8;
2678                 break;
2679
2680         case 'x':
2681                 spec->flags |= SMALL;
2682                 fallthrough;
2683
2684         case 'X':
2685                 spec->base = 16;
2686                 break;
2687
2688         case 'd':
2689         case 'i':
2690                 spec->flags |= SIGN;
2691                 break;
2692         case 'u':
2693                 break;
2694
2695         case 'n':
2696                 /*
2697                  * Since %n poses a greater security risk than
2698                  * utility, treat it as any other invalid or
2699                  * unsupported format specifier.
2700                  */
2701                 fallthrough;
2702
2703         default:
2704                 WARN_ONCE(1, "Please remove unsupported %%%c in format string\n", *fmt);
2705                 spec->type = FORMAT_TYPE_INVALID;
2706                 return fmt - start;
2707         }
2708
2709         if (qualifier == 'L')
2710                 spec->type = FORMAT_TYPE_LONG_LONG;
2711         else if (qualifier == 'l') {
2712                 BUILD_BUG_ON(FORMAT_TYPE_ULONG + SIGN != FORMAT_TYPE_LONG);
2713                 spec->type = FORMAT_TYPE_ULONG + (spec->flags & SIGN);
2714         } else if (qualifier == 'z') {
2715                 spec->type = FORMAT_TYPE_SIZE_T;
2716         } else if (qualifier == 't') {
2717                 spec->type = FORMAT_TYPE_PTRDIFF;
2718         } else if (qualifier == 'H') {
2719                 BUILD_BUG_ON(FORMAT_TYPE_UBYTE + SIGN != FORMAT_TYPE_BYTE);
2720                 spec->type = FORMAT_TYPE_UBYTE + (spec->flags & SIGN);
2721         } else if (qualifier == 'h') {
2722                 BUILD_BUG_ON(FORMAT_TYPE_USHORT + SIGN != FORMAT_TYPE_SHORT);
2723                 spec->type = FORMAT_TYPE_USHORT + (spec->flags & SIGN);
2724         } else {
2725                 BUILD_BUG_ON(FORMAT_TYPE_UINT + SIGN != FORMAT_TYPE_INT);
2726                 spec->type = FORMAT_TYPE_UINT + (spec->flags & SIGN);
2727         }
2728
2729         return ++fmt - start;
2730 }
2731
2732 static void
2733 set_field_width(struct printf_spec *spec, int width)
2734 {
2735         spec->field_width = width;
2736         if (WARN_ONCE(spec->field_width != width, "field width %d too large", width)) {
2737                 spec->field_width = clamp(width, -FIELD_WIDTH_MAX, FIELD_WIDTH_MAX);
2738         }
2739 }
2740
2741 static void
2742 set_precision(struct printf_spec *spec, int prec)
2743 {
2744         spec->precision = prec;
2745         if (WARN_ONCE(spec->precision != prec, "precision %d too large", prec)) {
2746                 spec->precision = clamp(prec, 0, PRECISION_MAX);
2747         }
2748 }
2749
2750 /**
2751  * vsnprintf - Format a string and place it in a buffer
2752  * @buf: The buffer to place the result into
2753  * @size: The size of the buffer, including the trailing null space
2754  * @fmt: The format string to use
2755  * @args: Arguments for the format string
2756  *
2757  * This function generally follows C99 vsnprintf, but has some
2758  * extensions and a few limitations:
2759  *
2760  *  - ``%n`` is unsupported
2761  *  - ``%p*`` is handled by pointer()
2762  *
2763  * See pointer() or Documentation/core-api/printk-formats.rst for more
2764  * extensive description.
2765  *
2766  * **Please update the documentation in both places when making changes**
2767  *
2768  * The return value is the number of characters which would
2769  * be generated for the given input, excluding the trailing
2770  * '\0', as per ISO C99. If you want to have the exact
2771  * number of characters written into @buf as return value
2772  * (not including the trailing '\0'), use vscnprintf(). If the
2773  * return is greater than or equal to @size, the resulting
2774  * string is truncated.
2775  *
2776  * If you're not already dealing with a va_list consider using snprintf().
2777  */
2778 int vsnprintf(char *buf, size_t size, const char *fmt, va_list args)
2779 {
2780         unsigned long long num;
2781         char *str, *end;
2782         struct printf_spec spec = {0};
2783
2784         /* Reject out-of-range values early.  Large positive sizes are
2785            used for unknown buffer sizes. */
2786         if (WARN_ON_ONCE(size > INT_MAX))
2787                 return 0;
2788
2789         str = buf;
2790         end = buf + size;
2791
2792         /* Make sure end is always >= buf */
2793         if (end < buf) {
2794                 end = ((void *)-1);
2795                 size = end - buf;
2796         }
2797
2798         while (*fmt) {
2799                 const char *old_fmt = fmt;
2800                 int read = format_decode(fmt, &spec);
2801
2802                 fmt += read;
2803
2804                 switch (spec.type) {
2805                 case FORMAT_TYPE_NONE: {
2806                         int copy = read;
2807                         if (str < end) {
2808                                 if (copy > end - str)
2809                                         copy = end - str;
2810                                 memcpy(str, old_fmt, copy);
2811                         }
2812                         str += read;
2813                         break;
2814                 }
2815
2816                 case FORMAT_TYPE_WIDTH:
2817                         set_field_width(&spec, va_arg(args, int));
2818                         break;
2819
2820                 case FORMAT_TYPE_PRECISION:
2821                         set_precision(&spec, va_arg(args, int));
2822                         break;
2823
2824                 case FORMAT_TYPE_CHAR: {
2825                         char c;
2826
2827                         if (!(spec.flags & LEFT)) {
2828                                 while (--spec.field_width > 0) {
2829                                         if (str < end)
2830                                                 *str = ' ';
2831                                         ++str;
2832
2833                                 }
2834                         }
2835                         c = (unsigned char) va_arg(args, int);
2836                         if (str < end)
2837                                 *str = c;
2838                         ++str;
2839                         while (--spec.field_width > 0) {
2840                                 if (str < end)
2841                                         *str = ' ';
2842                                 ++str;
2843                         }
2844                         break;
2845                 }
2846
2847                 case FORMAT_TYPE_STR:
2848                         str = string(str, end, va_arg(args, char *), spec);
2849                         break;
2850
2851                 case FORMAT_TYPE_PTR:
2852                         str = pointer(fmt, str, end, va_arg(args, void *),
2853                                       spec);
2854                         while (isalnum(*fmt))
2855                                 fmt++;
2856                         break;
2857
2858                 case FORMAT_TYPE_PERCENT_CHAR:
2859                         if (str < end)
2860                                 *str = '%';
2861                         ++str;
2862                         break;
2863
2864                 case FORMAT_TYPE_INVALID:
2865                         /*
2866                          * Presumably the arguments passed gcc's type
2867                          * checking, but there is no safe or sane way
2868                          * for us to continue parsing the format and
2869                          * fetching from the va_list; the remaining
2870                          * specifiers and arguments would be out of
2871                          * sync.
2872                          */
2873                         goto out;
2874
2875                 default:
2876                         switch (spec.type) {
2877                         case FORMAT_TYPE_LONG_LONG:
2878                                 num = va_arg(args, long long);
2879                                 break;
2880                         case FORMAT_TYPE_ULONG:
2881                                 num = va_arg(args, unsigned long);
2882                                 break;
2883                         case FORMAT_TYPE_LONG:
2884                                 num = va_arg(args, long);
2885                                 break;
2886                         case FORMAT_TYPE_SIZE_T:
2887                                 if (spec.flags & SIGN)
2888                                         num = va_arg(args, ssize_t);
2889                                 else
2890                                         num = va_arg(args, size_t);
2891                                 break;
2892                         case FORMAT_TYPE_PTRDIFF:
2893                                 num = va_arg(args, ptrdiff_t);
2894                                 break;
2895                         case FORMAT_TYPE_UBYTE:
2896                                 num = (unsigned char) va_arg(args, int);
2897                                 break;
2898                         case FORMAT_TYPE_BYTE:
2899                                 num = (signed char) va_arg(args, int);
2900                                 break;
2901                         case FORMAT_TYPE_USHORT:
2902                                 num = (unsigned short) va_arg(args, int);
2903                                 break;
2904                         case FORMAT_TYPE_SHORT:
2905                                 num = (short) va_arg(args, int);
2906                                 break;
2907                         case FORMAT_TYPE_INT:
2908                                 num = (int) va_arg(args, int);
2909                                 break;
2910                         default:
2911                                 num = va_arg(args, unsigned int);
2912                         }
2913
2914                         str = number(str, end, num, spec);
2915                 }
2916         }
2917
2918 out:
2919         if (size > 0) {
2920                 if (str < end)
2921                         *str = '\0';
2922                 else
2923                         end[-1] = '\0';
2924         }
2925
2926         /* the trailing null byte doesn't count towards the total */
2927         return str-buf;
2928
2929 }
2930 EXPORT_SYMBOL(vsnprintf);
2931
2932 /**
2933  * vscnprintf - Format a string and place it in a buffer
2934  * @buf: The buffer to place the result into
2935  * @size: The size of the buffer, including the trailing null space
2936  * @fmt: The format string to use
2937  * @args: Arguments for the format string
2938  *
2939  * The return value is the number of characters which have been written into
2940  * the @buf not including the trailing '\0'. If @size is == 0 the function
2941  * returns 0.
2942  *
2943  * If you're not already dealing with a va_list consider using scnprintf().
2944  *
2945  * See the vsnprintf() documentation for format string extensions over C99.
2946  */
2947 int vscnprintf(char *buf, size_t size, const char *fmt, va_list args)
2948 {
2949         int i;
2950
2951         if (unlikely(!size))
2952                 return 0;
2953
2954         i = vsnprintf(buf, size, fmt, args);
2955
2956         if (likely(i < size))
2957                 return i;
2958
2959         return size - 1;
2960 }
2961 EXPORT_SYMBOL(vscnprintf);
2962
2963 /**
2964  * snprintf - Format a string and place it in a buffer
2965  * @buf: The buffer to place the result into
2966  * @size: The size of the buffer, including the trailing null space
2967  * @fmt: The format string to use
2968  * @...: Arguments for the format string
2969  *
2970  * The return value is the number of characters which would be
2971  * generated for the given input, excluding the trailing null,
2972  * as per ISO C99.  If the return is greater than or equal to
2973  * @size, the resulting string is truncated.
2974  *
2975  * See the vsnprintf() documentation for format string extensions over C99.
2976  */
2977 int snprintf(char *buf, size_t size, const char *fmt, ...)
2978 {
2979         va_list args;
2980         int i;
2981
2982         va_start(args, fmt);
2983         i = vsnprintf(buf, size, fmt, args);
2984         va_end(args);
2985
2986         return i;
2987 }
2988 EXPORT_SYMBOL(snprintf);
2989
2990 /**
2991  * scnprintf - Format a string 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  * @...: Arguments for the format string
2996  *
2997  * The return value is the number of characters written into @buf not including
2998  * the trailing '\0'. If @size is == 0 the function returns 0.
2999  */
3000
3001 int scnprintf(char *buf, size_t size, const char *fmt, ...)
3002 {
3003         va_list args;
3004         int i;
3005
3006         va_start(args, fmt);
3007         i = vscnprintf(buf, size, fmt, args);
3008         va_end(args);
3009
3010         return i;
3011 }
3012 EXPORT_SYMBOL(scnprintf);
3013
3014 /**
3015  * vsprintf - Format a string and place it in a buffer
3016  * @buf: The buffer to place the result into
3017  * @fmt: The format string to use
3018  * @args: Arguments for the format string
3019  *
3020  * The function returns the number of characters written
3021  * into @buf. Use vsnprintf() or vscnprintf() in order to avoid
3022  * buffer overflows.
3023  *
3024  * If you're not already dealing with a va_list consider using sprintf().
3025  *
3026  * See the vsnprintf() documentation for format string extensions over C99.
3027  */
3028 int vsprintf(char *buf, const char *fmt, va_list args)
3029 {
3030         return vsnprintf(buf, INT_MAX, fmt, args);
3031 }
3032 EXPORT_SYMBOL(vsprintf);
3033
3034 /**
3035  * sprintf - Format a string and place it in a buffer
3036  * @buf: The buffer to place the result into
3037  * @fmt: The format string to use
3038  * @...: Arguments for the format string
3039  *
3040  * The function returns the number of characters written
3041  * into @buf. Use snprintf() or scnprintf() in order to avoid
3042  * buffer overflows.
3043  *
3044  * See the vsnprintf() documentation for format string extensions over C99.
3045  */
3046 int sprintf(char *buf, const char *fmt, ...)
3047 {
3048         va_list args;
3049         int i;
3050
3051         va_start(args, fmt);
3052         i = vsnprintf(buf, INT_MAX, fmt, args);
3053         va_end(args);
3054
3055         return i;
3056 }
3057 EXPORT_SYMBOL(sprintf);
3058
3059 #ifdef CONFIG_BINARY_PRINTF
3060 /*
3061  * bprintf service:
3062  * vbin_printf() - VA arguments to binary data
3063  * bstr_printf() - Binary data to text string
3064  */
3065
3066 /**
3067  * vbin_printf - Parse a format string and place args' binary value in a buffer
3068  * @bin_buf: The buffer to place args' binary value
3069  * @size: The size of the buffer(by words(32bits), not characters)
3070  * @fmt: The format string to use
3071  * @args: Arguments for the format string
3072  *
3073  * The format follows C99 vsnprintf, except %n is ignored, and its argument
3074  * is skipped.
3075  *
3076  * The return value is the number of words(32bits) which would be generated for
3077  * the given input.
3078  *
3079  * NOTE:
3080  * If the return value is greater than @size, the resulting bin_buf is NOT
3081  * valid for bstr_printf().
3082  */
3083 int vbin_printf(u32 *bin_buf, size_t size, const char *fmt, va_list args)
3084 {
3085         struct printf_spec spec = {0};
3086         char *str, *end;
3087         int width;
3088
3089         str = (char *)bin_buf;
3090         end = (char *)(bin_buf + size);
3091
3092 #define save_arg(type)                                                  \
3093 ({                                                                      \
3094         unsigned long long value;                                       \
3095         if (sizeof(type) == 8) {                                        \
3096                 unsigned long long val8;                                \
3097                 str = PTR_ALIGN(str, sizeof(u32));                      \
3098                 val8 = va_arg(args, unsigned long long);                \
3099                 if (str + sizeof(type) <= end) {                        \
3100                         *(u32 *)str = *(u32 *)&val8;                    \
3101                         *(u32 *)(str + 4) = *((u32 *)&val8 + 1);        \
3102                 }                                                       \
3103                 value = val8;                                           \
3104         } else {                                                        \
3105                 unsigned int val4;                                      \
3106                 str = PTR_ALIGN(str, sizeof(type));                     \
3107                 val4 = va_arg(args, int);                               \
3108                 if (str + sizeof(type) <= end)                          \
3109                         *(typeof(type) *)str = (type)(long)val4;        \
3110                 value = (unsigned long long)val4;                       \
3111         }                                                               \
3112         str += sizeof(type);                                            \
3113         value;                                                          \
3114 })
3115
3116         while (*fmt) {
3117                 int read = format_decode(fmt, &spec);
3118
3119                 fmt += read;
3120
3121                 switch (spec.type) {
3122                 case FORMAT_TYPE_NONE:
3123                 case FORMAT_TYPE_PERCENT_CHAR:
3124                         break;
3125                 case FORMAT_TYPE_INVALID:
3126                         goto out;
3127
3128                 case FORMAT_TYPE_WIDTH:
3129                 case FORMAT_TYPE_PRECISION:
3130                         width = (int)save_arg(int);
3131                         /* Pointers may require the width */
3132                         if (*fmt == 'p')
3133                                 set_field_width(&spec, width);
3134                         break;
3135
3136                 case FORMAT_TYPE_CHAR:
3137                         save_arg(char);
3138                         break;
3139
3140                 case FORMAT_TYPE_STR: {
3141                         const char *save_str = va_arg(args, char *);
3142                         const char *err_msg;
3143                         size_t len;
3144
3145                         err_msg = check_pointer_msg(save_str);
3146                         if (err_msg)
3147                                 save_str = err_msg;
3148
3149                         len = strlen(save_str) + 1;
3150                         if (str + len < end)
3151                                 memcpy(str, save_str, len);
3152                         str += len;
3153                         break;
3154                 }
3155
3156                 case FORMAT_TYPE_PTR:
3157                         /* Dereferenced pointers must be done now */
3158                         switch (*fmt) {
3159                         /* Dereference of functions is still OK */
3160                         case 'S':
3161                         case 's':
3162                         case 'x':
3163                         case 'K':
3164                         case 'e':
3165                                 save_arg(void *);
3166                                 break;
3167                         default:
3168                                 if (!isalnum(*fmt)) {
3169                                         save_arg(void *);
3170                                         break;
3171                                 }
3172                                 str = pointer(fmt, str, end, va_arg(args, void *),
3173                                               spec);
3174                                 if (str + 1 < end)
3175                                         *str++ = '\0';
3176                                 else
3177                                         end[-1] = '\0'; /* Must be nul terminated */
3178                         }
3179                         /* skip all alphanumeric pointer suffixes */
3180                         while (isalnum(*fmt))
3181                                 fmt++;
3182                         break;
3183
3184                 default:
3185                         switch (spec.type) {
3186
3187                         case FORMAT_TYPE_LONG_LONG:
3188                                 save_arg(long long);
3189                                 break;
3190                         case FORMAT_TYPE_ULONG:
3191                         case FORMAT_TYPE_LONG:
3192                                 save_arg(unsigned long);
3193                                 break;
3194                         case FORMAT_TYPE_SIZE_T:
3195                                 save_arg(size_t);
3196                                 break;
3197                         case FORMAT_TYPE_PTRDIFF:
3198                                 save_arg(ptrdiff_t);
3199                                 break;
3200                         case FORMAT_TYPE_UBYTE:
3201                         case FORMAT_TYPE_BYTE:
3202                                 save_arg(char);
3203                                 break;
3204                         case FORMAT_TYPE_USHORT:
3205                         case FORMAT_TYPE_SHORT:
3206                                 save_arg(short);
3207                                 break;
3208                         default:
3209                                 save_arg(int);
3210                         }
3211                 }
3212         }
3213
3214 out:
3215         return (u32 *)(PTR_ALIGN(str, sizeof(u32))) - bin_buf;
3216 #undef save_arg
3217 }
3218 EXPORT_SYMBOL_GPL(vbin_printf);
3219
3220 /**
3221  * bstr_printf - Format a string from binary arguments and place it in a buffer
3222  * @buf: The buffer to place the result into
3223  * @size: The size of the buffer, including the trailing null space
3224  * @fmt: The format string to use
3225  * @bin_buf: Binary arguments for the format string
3226  *
3227  * This function like C99 vsnprintf, but the difference is that vsnprintf gets
3228  * arguments from stack, and bstr_printf gets arguments from @bin_buf which is
3229  * a binary buffer that generated by vbin_printf.
3230  *
3231  * The format follows C99 vsnprintf, but has some extensions:
3232  *  see vsnprintf comment for details.
3233  *
3234  * The return value is the number of characters which would
3235  * be generated for the given input, excluding the trailing
3236  * '\0', as per ISO C99. If you want to have the exact
3237  * number of characters written into @buf as return value
3238  * (not including the trailing '\0'), use vscnprintf(). If the
3239  * return is greater than or equal to @size, the resulting
3240  * string is truncated.
3241  */
3242 int bstr_printf(char *buf, size_t size, const char *fmt, const u32 *bin_buf)
3243 {
3244         struct printf_spec spec = {0};
3245         char *str, *end;
3246         const char *args = (const char *)bin_buf;
3247
3248         if (WARN_ON_ONCE(size > INT_MAX))
3249                 return 0;
3250
3251         str = buf;
3252         end = buf + size;
3253
3254 #define get_arg(type)                                                   \
3255 ({                                                                      \
3256         typeof(type) value;                                             \
3257         if (sizeof(type) == 8) {                                        \
3258                 args = PTR_ALIGN(args, sizeof(u32));                    \
3259                 *(u32 *)&value = *(u32 *)args;                          \
3260                 *((u32 *)&value + 1) = *(u32 *)(args + 4);              \
3261         } else {                                                        \
3262                 args = PTR_ALIGN(args, sizeof(type));                   \
3263                 value = *(typeof(type) *)args;                          \
3264         }                                                               \
3265         args += sizeof(type);                                           \
3266         value;                                                          \
3267 })
3268
3269         /* Make sure end is always >= buf */
3270         if (end < buf) {
3271                 end = ((void *)-1);
3272                 size = end - buf;
3273         }
3274
3275         while (*fmt) {
3276                 const char *old_fmt = fmt;
3277                 int read = format_decode(fmt, &spec);
3278
3279                 fmt += read;
3280
3281                 switch (spec.type) {
3282                 case FORMAT_TYPE_NONE: {
3283                         int copy = read;
3284                         if (str < end) {
3285                                 if (copy > end - str)
3286                                         copy = end - str;
3287                                 memcpy(str, old_fmt, copy);
3288                         }
3289                         str += read;
3290                         break;
3291                 }
3292
3293                 case FORMAT_TYPE_WIDTH:
3294                         set_field_width(&spec, get_arg(int));
3295                         break;
3296
3297                 case FORMAT_TYPE_PRECISION:
3298                         set_precision(&spec, get_arg(int));
3299                         break;
3300
3301                 case FORMAT_TYPE_CHAR: {
3302                         char c;
3303
3304                         if (!(spec.flags & LEFT)) {
3305                                 while (--spec.field_width > 0) {
3306                                         if (str < end)
3307                                                 *str = ' ';
3308                                         ++str;
3309                                 }
3310                         }
3311                         c = (unsigned char) get_arg(char);
3312                         if (str < end)
3313                                 *str = c;
3314                         ++str;
3315                         while (--spec.field_width > 0) {
3316                                 if (str < end)
3317                                         *str = ' ';
3318                                 ++str;
3319                         }
3320                         break;
3321                 }
3322
3323                 case FORMAT_TYPE_STR: {
3324                         const char *str_arg = args;
3325                         args += strlen(str_arg) + 1;
3326                         str = string(str, end, (char *)str_arg, spec);
3327                         break;
3328                 }
3329
3330                 case FORMAT_TYPE_PTR: {
3331                         bool process = false;
3332                         int copy, len;
3333                         /* Non function dereferences were already done */
3334                         switch (*fmt) {
3335                         case 'S':
3336                         case 's':
3337                         case 'x':
3338                         case 'K':
3339                         case 'e':
3340                                 process = true;
3341                                 break;
3342                         default:
3343                                 if (!isalnum(*fmt)) {
3344                                         process = true;
3345                                         break;
3346                                 }
3347                                 /* Pointer dereference was already processed */
3348                                 if (str < end) {
3349                                         len = copy = strlen(args);
3350                                         if (copy > end - str)
3351                                                 copy = end - str;
3352                                         memcpy(str, args, copy);
3353                                         str += len;
3354                                         args += len + 1;
3355                                 }
3356                         }
3357                         if (process)
3358                                 str = pointer(fmt, str, end, get_arg(void *), spec);
3359
3360                         while (isalnum(*fmt))
3361                                 fmt++;
3362                         break;
3363                 }
3364
3365                 case FORMAT_TYPE_PERCENT_CHAR:
3366                         if (str < end)
3367                                 *str = '%';
3368                         ++str;
3369                         break;
3370
3371                 case FORMAT_TYPE_INVALID:
3372                         goto out;
3373
3374                 default: {
3375                         unsigned long long num;
3376
3377                         switch (spec.type) {
3378
3379                         case FORMAT_TYPE_LONG_LONG:
3380                                 num = get_arg(long long);
3381                                 break;
3382                         case FORMAT_TYPE_ULONG:
3383                         case FORMAT_TYPE_LONG:
3384                                 num = get_arg(unsigned long);
3385                                 break;
3386                         case FORMAT_TYPE_SIZE_T:
3387                                 num = get_arg(size_t);
3388                                 break;
3389                         case FORMAT_TYPE_PTRDIFF:
3390                                 num = get_arg(ptrdiff_t);
3391                                 break;
3392                         case FORMAT_TYPE_UBYTE:
3393                                 num = get_arg(unsigned char);
3394                                 break;
3395                         case FORMAT_TYPE_BYTE:
3396                                 num = get_arg(signed char);
3397                                 break;
3398                         case FORMAT_TYPE_USHORT:
3399                                 num = get_arg(unsigned short);
3400                                 break;
3401                         case FORMAT_TYPE_SHORT:
3402                                 num = get_arg(short);
3403                                 break;
3404                         case FORMAT_TYPE_UINT:
3405                                 num = get_arg(unsigned int);
3406                                 break;
3407                         default:
3408                                 num = get_arg(int);
3409                         }
3410
3411                         str = number(str, end, num, spec);
3412                 } /* default: */
3413                 } /* switch(spec.type) */
3414         } /* while(*fmt) */
3415
3416 out:
3417         if (size > 0) {
3418                 if (str < end)
3419                         *str = '\0';
3420                 else
3421                         end[-1] = '\0';
3422         }
3423
3424 #undef get_arg
3425
3426         /* the trailing null byte doesn't count towards the total */
3427         return str - buf;
3428 }
3429 EXPORT_SYMBOL_GPL(bstr_printf);
3430
3431 #endif /* CONFIG_BINARY_PRINTF */
3432
3433 /**
3434  * vsscanf - Unformat a buffer into a list of arguments
3435  * @buf:        input buffer
3436  * @fmt:        format of buffer
3437  * @args:       arguments
3438  */
3439 int vsscanf(const char *buf, const char *fmt, va_list args)
3440 {
3441         const char *str = buf;
3442         char *next;
3443         char digit;
3444         int num = 0;
3445         u8 qualifier;
3446         unsigned int base;
3447         union {
3448                 long long s;
3449                 unsigned long long u;
3450         } val;
3451         s16 field_width;
3452         bool is_sign;
3453
3454         while (*fmt) {
3455                 /* skip any white space in format */
3456                 /* white space in format matches any amount of
3457                  * white space, including none, in the input.
3458                  */
3459                 if (isspace(*fmt)) {
3460                         fmt = skip_spaces(++fmt);
3461                         str = skip_spaces(str);
3462                 }
3463
3464                 /* anything that is not a conversion must match exactly */
3465                 if (*fmt != '%' && *fmt) {
3466                         if (*fmt++ != *str++)
3467                                 break;
3468                         continue;
3469                 }
3470
3471                 if (!*fmt)
3472                         break;
3473                 ++fmt;
3474
3475                 /* skip this conversion.
3476                  * advance both strings to next white space
3477                  */
3478                 if (*fmt == '*') {
3479                         if (!*str)
3480                                 break;
3481                         while (!isspace(*fmt) && *fmt != '%' && *fmt) {
3482                                 /* '%*[' not yet supported, invalid format */
3483                                 if (*fmt == '[')
3484                                         return num;
3485                                 fmt++;
3486                         }
3487                         while (!isspace(*str) && *str)
3488                                 str++;
3489                         continue;
3490                 }
3491
3492                 /* get field width */
3493                 field_width = -1;
3494                 if (isdigit(*fmt)) {
3495                         field_width = skip_atoi(&fmt);
3496                         if (field_width <= 0)
3497                                 break;
3498                 }
3499
3500                 /* get conversion qualifier */
3501                 qualifier = -1;
3502                 if (*fmt == 'h' || _tolower(*fmt) == 'l' ||
3503                     *fmt == 'z') {
3504                         qualifier = *fmt++;
3505                         if (unlikely(qualifier == *fmt)) {
3506                                 if (qualifier == 'h') {
3507                                         qualifier = 'H';
3508                                         fmt++;
3509                                 } else if (qualifier == 'l') {
3510                                         qualifier = 'L';
3511                                         fmt++;
3512                                 }
3513                         }
3514                 }
3515
3516                 if (!*fmt)
3517                         break;
3518
3519                 if (*fmt == 'n') {
3520                         /* return number of characters read so far */
3521                         *va_arg(args, int *) = str - buf;
3522                         ++fmt;
3523                         continue;
3524                 }
3525
3526                 if (!*str)
3527                         break;
3528
3529                 base = 10;
3530                 is_sign = false;
3531
3532                 switch (*fmt++) {
3533                 case 'c':
3534                 {
3535                         char *s = (char *)va_arg(args, char*);
3536                         if (field_width == -1)
3537                                 field_width = 1;
3538                         do {
3539                                 *s++ = *str++;
3540                         } while (--field_width > 0 && *str);
3541                         num++;
3542                 }
3543                 continue;
3544                 case 's':
3545                 {
3546                         char *s = (char *)va_arg(args, char *);
3547                         if (field_width == -1)
3548                                 field_width = SHRT_MAX;
3549                         /* first, skip leading white space in buffer */
3550                         str = skip_spaces(str);
3551
3552                         /* now copy until next white space */
3553                         while (*str && !isspace(*str) && field_width--)
3554                                 *s++ = *str++;
3555                         *s = '\0';
3556                         num++;
3557                 }
3558                 continue;
3559                 /*
3560                  * Warning: This implementation of the '[' conversion specifier
3561                  * deviates from its glibc counterpart in the following ways:
3562                  * (1) It does NOT support ranges i.e. '-' is NOT a special
3563                  *     character
3564                  * (2) It cannot match the closing bracket ']' itself
3565                  * (3) A field width is required
3566                  * (4) '%*[' (discard matching input) is currently not supported
3567                  *
3568                  * Example usage:
3569                  * ret = sscanf("00:0a:95","%2[^:]:%2[^:]:%2[^:]",
3570                  *              buf1, buf2, buf3);
3571                  * if (ret < 3)
3572                  *    // etc..
3573                  */
3574                 case '[':
3575                 {
3576                         char *s = (char *)va_arg(args, char *);
3577                         DECLARE_BITMAP(set, 256) = {0};
3578                         unsigned int len = 0;
3579                         bool negate = (*fmt == '^');
3580
3581                         /* field width is required */
3582                         if (field_width == -1)
3583                                 return num;
3584
3585                         if (negate)
3586                                 ++fmt;
3587
3588                         for ( ; *fmt && *fmt != ']'; ++fmt, ++len)
3589                                 __set_bit((u8)*fmt, set);
3590
3591                         /* no ']' or no character set found */
3592                         if (!*fmt || !len)
3593                                 return num;
3594                         ++fmt;
3595
3596                         if (negate) {
3597                                 bitmap_complement(set, set, 256);
3598                                 /* exclude null '\0' byte */
3599                                 __clear_bit(0, set);
3600                         }
3601
3602                         /* match must be non-empty */
3603                         if (!test_bit((u8)*str, set))
3604                                 return num;
3605
3606                         while (test_bit((u8)*str, set) && field_width--)
3607                                 *s++ = *str++;
3608                         *s = '\0';
3609                         ++num;
3610                 }
3611                 continue;
3612                 case 'o':
3613                         base = 8;
3614                         break;
3615                 case 'x':
3616                 case 'X':
3617                         base = 16;
3618                         break;
3619                 case 'i':
3620                         base = 0;
3621                         fallthrough;
3622                 case 'd':
3623                         is_sign = true;
3624                         fallthrough;
3625                 case 'u':
3626                         break;
3627                 case '%':
3628                         /* looking for '%' in str */
3629                         if (*str++ != '%')
3630                                 return num;
3631                         continue;
3632                 default:
3633                         /* invalid format; stop here */
3634                         return num;
3635                 }
3636
3637                 /* have some sort of integer conversion.
3638                  * first, skip white space in buffer.
3639                  */
3640                 str = skip_spaces(str);
3641
3642                 digit = *str;
3643                 if (is_sign && digit == '-') {
3644                         if (field_width == 1)
3645                                 break;
3646
3647                         digit = *(str + 1);
3648                 }
3649
3650                 if (!digit
3651                     || (base == 16 && !isxdigit(digit))
3652                     || (base == 10 && !isdigit(digit))
3653                     || (base == 8 && !isodigit(digit))
3654                     || (base == 0 && !isdigit(digit)))
3655                         break;
3656
3657                 if (is_sign)
3658                         val.s = simple_strntoll(str, &next, base,
3659                                                 field_width >= 0 ? field_width : INT_MAX);
3660                 else
3661                         val.u = simple_strntoull(str, &next, base,
3662                                                  field_width >= 0 ? field_width : INT_MAX);
3663
3664                 switch (qualifier) {
3665                 case 'H':       /* that's 'hh' in format */
3666                         if (is_sign)
3667                                 *va_arg(args, signed char *) = val.s;
3668                         else
3669                                 *va_arg(args, unsigned char *) = val.u;
3670                         break;
3671                 case 'h':
3672                         if (is_sign)
3673                                 *va_arg(args, short *) = val.s;
3674                         else
3675                                 *va_arg(args, unsigned short *) = val.u;
3676                         break;
3677                 case 'l':
3678                         if (is_sign)
3679                                 *va_arg(args, long *) = val.s;
3680                         else
3681                                 *va_arg(args, unsigned long *) = val.u;
3682                         break;
3683                 case 'L':
3684                         if (is_sign)
3685                                 *va_arg(args, long long *) = val.s;
3686                         else
3687                                 *va_arg(args, unsigned long long *) = val.u;
3688                         break;
3689                 case 'z':
3690                         *va_arg(args, size_t *) = val.u;
3691                         break;
3692                 default:
3693                         if (is_sign)
3694                                 *va_arg(args, int *) = val.s;
3695                         else
3696                                 *va_arg(args, unsigned int *) = val.u;
3697                         break;
3698                 }
3699                 num++;
3700
3701                 if (!next)
3702                         break;
3703                 str = next;
3704         }
3705
3706         return num;
3707 }
3708 EXPORT_SYMBOL(vsscanf);
3709
3710 /**
3711  * sscanf - Unformat a buffer into a list of arguments
3712  * @buf:        input buffer
3713  * @fmt:        formatting of buffer
3714  * @...:        resulting arguments
3715  */
3716 int sscanf(const char *buf, const char *fmt, ...)
3717 {
3718         va_list args;
3719         int i;
3720
3721         va_start(args, fmt);
3722         i = vsscanf(buf, fmt, args);
3723         va_end(args);
3724
3725         return i;
3726 }
3727 EXPORT_SYMBOL(sscanf);