linux/lib/vsprintf.c
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   1/*
   2 *  linux/lib/vsprintf.c
   3 *
   4 *  Copyright (C) 1991, 1992  Linus Torvalds
   5 */
   6
   7/* vsprintf.c -- Lars Wirzenius & Linus Torvalds. */
   8/*
   9 * Wirzenius wrote this portably, Torvalds fucked it up :-)
  10 */
  11
  12/*
  13 * Fri Jul 13 2001 Crutcher Dunnavant <crutcher+kernel@datastacks.com>
  14 * - changed to provide snprintf and vsnprintf functions
  15 * So Feb  1 16:51:32 CET 2004 Juergen Quade <quade@hsnr.de>
  16 * - scnprintf and vscnprintf
  17 */
  18
  19#include <stdarg.h>
  20#include <linux/clk.h>
  21#include <linux/clk-provider.h>
  22#include <linux/module.h>       /* for KSYM_SYMBOL_LEN */
  23#include <linux/types.h>
  24#include <linux/string.h>
  25#include <linux/ctype.h>
  26#include <linux/kernel.h>
  27#include <linux/kallsyms.h>
  28#include <linux/math64.h>
  29#include <linux/uaccess.h>
  30#include <linux/ioport.h>
  31#include <linux/dcache.h>
  32#include <linux/cred.h>
  33#include <linux/uuid.h>
  34#include <linux/of.h>
  35#include <net/addrconf.h>
  36#include <linux/siphash.h>
  37#include <linux/compiler.h>
  38#ifdef CONFIG_BLOCK
  39#include <linux/blkdev.h>
  40#endif
  41
  42#include "../mm/internal.h"     /* For the trace_print_flags arrays */
  43
  44#include <asm/page.h>           /* for PAGE_SIZE */
  45#include <asm/byteorder.h>      /* cpu_to_le16 */
  46
  47#include <linux/string_helpers.h>
  48#include "kstrtox.h"
  49
  50/**
  51 * simple_strtoull - convert a string to an unsigned long long
  52 * @cp: The start of the string
  53 * @endp: A pointer to the end of the parsed string will be placed here
  54 * @base: The number base to use
  55 *
  56 * This function is obsolete. Please use kstrtoull instead.
  57 */
  58unsigned long long simple_strtoull(const char *cp, char **endp, unsigned int base)
  59{
  60        unsigned long long result;
  61        unsigned int rv;
  62
  63        cp = _parse_integer_fixup_radix(cp, &base);
  64        rv = _parse_integer(cp, base, &result);
  65        /* FIXME */
  66        cp += (rv & ~KSTRTOX_OVERFLOW);
  67
  68        if (endp)
  69                *endp = (char *)cp;
  70
  71        return result;
  72}
  73EXPORT_SYMBOL(simple_strtoull);
  74
  75/**
  76 * simple_strtoul - convert a string to an unsigned long
  77 * @cp: The start of the string
  78 * @endp: A pointer to the end of the parsed string will be placed here
  79 * @base: The number base to use
  80 *
  81 * This function is obsolete. Please use kstrtoul instead.
  82 */
  83unsigned long simple_strtoul(const char *cp, char **endp, unsigned int base)
  84{
  85        return simple_strtoull(cp, endp, base);
  86}
  87EXPORT_SYMBOL(simple_strtoul);
  88
  89/**
  90 * simple_strtol - convert a string to a signed long
  91 * @cp: The start of the string
  92 * @endp: A pointer to the end of the parsed string will be placed here
  93 * @base: The number base to use
  94 *
  95 * This function is obsolete. Please use kstrtol instead.
  96 */
  97long simple_strtol(const char *cp, char **endp, unsigned int base)
  98{
  99        if (*cp == '-')
 100                return -simple_strtoul(cp + 1, endp, base);
 101
 102        return simple_strtoul(cp, endp, base);
 103}
 104EXPORT_SYMBOL(simple_strtol);
 105
 106/**
 107 * simple_strtoll - convert a string to a signed long long
 108 * @cp: The start of the string
 109 * @endp: A pointer to the end of the parsed string will be placed here
 110 * @base: The number base to use
 111 *
 112 * This function is obsolete. Please use kstrtoll instead.
 113 */
 114long long simple_strtoll(const char *cp, char **endp, unsigned int base)
 115{
 116        if (*cp == '-')
 117                return -simple_strtoull(cp + 1, endp, base);
 118
 119        return simple_strtoull(cp, endp, base);
 120}
 121EXPORT_SYMBOL(simple_strtoll);
 122
 123static noinline_for_stack
 124int skip_atoi(const char **s)
 125{
 126        int i = 0;
 127
 128        do {
 129                i = i*10 + *((*s)++) - '0';
 130        } while (isdigit(**s));
 131
 132        return i;
 133}
 134
 135/*
 136 * Decimal conversion is by far the most typical, and is used for
 137 * /proc and /sys data. This directly impacts e.g. top performance
 138 * with many processes running. We optimize it for speed by emitting
 139 * two characters at a time, using a 200 byte lookup table. This
 140 * roughly halves the number of multiplications compared to computing
 141 * the digits one at a time. Implementation strongly inspired by the
 142 * previous version, which in turn used ideas described at
 143 * <http://www.cs.uiowa.edu/~jones/bcd/divide.html> (with permission
 144 * from the author, Douglas W. Jones).
 145 *
 146 * It turns out there is precisely one 26 bit fixed-point
 147 * approximation a of 64/100 for which x/100 == (x * (u64)a) >> 32
 148 * holds for all x in [0, 10^8-1], namely a = 0x28f5c29. The actual
 149 * range happens to be somewhat larger (x <= 1073741898), but that's
 150 * irrelevant for our purpose.
 151 *
 152 * For dividing a number in the range [10^4, 10^6-1] by 100, we still
 153 * need a 32x32->64 bit multiply, so we simply use the same constant.
 154 *
 155 * For dividing a number in the range [100, 10^4-1] by 100, there are
 156 * several options. The simplest is (x * 0x147b) >> 19, which is valid
 157 * for all x <= 43698.
 158 */
 159
 160static const u16 decpair[100] = {
 161#define _(x) (__force u16) cpu_to_le16(((x % 10) | ((x / 10) << 8)) + 0x3030)
 162        _( 0), _( 1), _( 2), _( 3), _( 4), _( 5), _( 6), _( 7), _( 8), _( 9),
 163        _(10), _(11), _(12), _(13), _(14), _(15), _(16), _(17), _(18), _(19),
 164        _(20), _(21), _(22), _(23), _(24), _(25), _(26), _(27), _(28), _(29),
 165        _(30), _(31), _(32), _(33), _(34), _(35), _(36), _(37), _(38), _(39),
 166        _(40), _(41), _(42), _(43), _(44), _(45), _(46), _(47), _(48), _(49),
 167        _(50), _(51), _(52), _(53), _(54), _(55), _(56), _(57), _(58), _(59),
 168        _(60), _(61), _(62), _(63), _(64), _(65), _(66), _(67), _(68), _(69),
 169        _(70), _(71), _(72), _(73), _(74), _(75), _(76), _(77), _(78), _(79),
 170        _(80), _(81), _(82), _(83), _(84), _(85), _(86), _(87), _(88), _(89),
 171        _(90), _(91), _(92), _(93), _(94), _(95), _(96), _(97), _(98), _(99),
 172#undef _
 173};
 174
 175/*
 176 * This will print a single '0' even if r == 0, since we would
 177 * immediately jump to out_r where two 0s would be written but only
 178 * one of them accounted for in buf. This is needed by ip4_string
 179 * below. All other callers pass a non-zero value of r.
 180*/
 181static noinline_for_stack
 182char *put_dec_trunc8(char *buf, unsigned r)
 183{
 184        unsigned q;
 185
 186        /* 1 <= r < 10^8 */
 187        if (r < 100)
 188                goto out_r;
 189
 190        /* 100 <= r < 10^8 */
 191        q = (r * (u64)0x28f5c29) >> 32;
 192        *((u16 *)buf) = decpair[r - 100*q];
 193        buf += 2;
 194
 195        /* 1 <= q < 10^6 */
 196        if (q < 100)
 197                goto out_q;
 198
 199        /*  100 <= q < 10^6 */
 200        r = (q * (u64)0x28f5c29) >> 32;
 201        *((u16 *)buf) = decpair[q - 100*r];
 202        buf += 2;
 203
 204        /* 1 <= r < 10^4 */
 205        if (r < 100)
 206                goto out_r;
 207
 208        /* 100 <= r < 10^4 */
 209        q = (r * 0x147b) >> 19;
 210        *((u16 *)buf) = decpair[r - 100*q];
 211        buf += 2;
 212out_q:
 213        /* 1 <= q < 100 */
 214        r = q;
 215out_r:
 216        /* 1 <= r < 100 */
 217        *((u16 *)buf) = decpair[r];
 218        buf += r < 10 ? 1 : 2;
 219        return buf;
 220}
 221
 222#if BITS_PER_LONG == 64 && BITS_PER_LONG_LONG == 64
 223static noinline_for_stack
 224char *put_dec_full8(char *buf, unsigned r)
 225{
 226        unsigned q;
 227
 228        /* 0 <= r < 10^8 */
 229        q = (r * (u64)0x28f5c29) >> 32;
 230        *((u16 *)buf) = decpair[r - 100*q];
 231        buf += 2;
 232
 233        /* 0 <= q < 10^6 */
 234        r = (q * (u64)0x28f5c29) >> 32;
 235        *((u16 *)buf) = decpair[q - 100*r];
 236        buf += 2;
 237
 238        /* 0 <= r < 10^4 */
 239        q = (r * 0x147b) >> 19;
 240        *((u16 *)buf) = decpair[r - 100*q];
 241        buf += 2;
 242
 243        /* 0 <= q < 100 */
 244        *((u16 *)buf) = decpair[q];
 245        buf += 2;
 246        return buf;
 247}
 248
 249static noinline_for_stack
 250char *put_dec(char *buf, unsigned long long n)
 251{
 252        if (n >= 100*1000*1000)
 253                buf = put_dec_full8(buf, do_div(n, 100*1000*1000));
 254        /* 1 <= n <= 1.6e11 */
 255        if (n >= 100*1000*1000)
 256                buf = put_dec_full8(buf, do_div(n, 100*1000*1000));
 257        /* 1 <= n < 1e8 */
 258        return put_dec_trunc8(buf, n);
 259}
 260
 261#elif BITS_PER_LONG == 32 && BITS_PER_LONG_LONG == 64
 262
 263static void
 264put_dec_full4(char *buf, unsigned r)
 265{
 266        unsigned q;
 267
 268        /* 0 <= r < 10^4 */
 269        q = (r * 0x147b) >> 19;
 270        *((u16 *)buf) = decpair[r - 100*q];
 271        buf += 2;
 272        /* 0 <= q < 100 */
 273        *((u16 *)buf) = decpair[q];
 274}
 275
 276/*
 277 * Call put_dec_full4 on x % 10000, return x / 10000.
 278 * The approximation x/10000 == (x * 0x346DC5D7) >> 43
 279 * holds for all x < 1,128,869,999.  The largest value this
 280 * helper will ever be asked to convert is 1,125,520,955.
 281 * (second call in the put_dec code, assuming n is all-ones).
 282 */
 283static noinline_for_stack
 284unsigned put_dec_helper4(char *buf, unsigned x)
 285{
 286        uint32_t q = (x * (uint64_t)0x346DC5D7) >> 43;
 287
 288        put_dec_full4(buf, x - q * 10000);
 289        return q;
 290}
 291
 292/* Based on code by Douglas W. Jones found at
 293 * <http://www.cs.uiowa.edu/~jones/bcd/decimal.html#sixtyfour>
 294 * (with permission from the author).
 295 * Performs no 64-bit division and hence should be fast on 32-bit machines.
 296 */
 297static
 298char *put_dec(char *buf, unsigned long long n)
 299{
 300        uint32_t d3, d2, d1, q, h;
 301
 302        if (n < 100*1000*1000)
 303                return put_dec_trunc8(buf, n);
 304
 305        d1  = ((uint32_t)n >> 16); /* implicit "& 0xffff" */
 306        h   = (n >> 32);
 307        d2  = (h      ) & 0xffff;
 308        d3  = (h >> 16); /* implicit "& 0xffff" */
 309
 310        /* n = 2^48 d3 + 2^32 d2 + 2^16 d1 + d0
 311             = 281_4749_7671_0656 d3 + 42_9496_7296 d2 + 6_5536 d1 + d0 */
 312        q   = 656 * d3 + 7296 * d2 + 5536 * d1 + ((uint32_t)n & 0xffff);
 313        q = put_dec_helper4(buf, q);
 314
 315        q += 7671 * d3 + 9496 * d2 + 6 * d1;
 316        q = put_dec_helper4(buf+4, q);
 317
 318        q += 4749 * d3 + 42 * d2;
 319        q = put_dec_helper4(buf+8, q);
 320
 321        q += 281 * d3;
 322        buf += 12;
 323        if (q)
 324                buf = put_dec_trunc8(buf, q);
 325        else while (buf[-1] == '0')
 326                --buf;
 327
 328        return buf;
 329}
 330
 331#endif
 332
 333/*
 334 * Convert passed number to decimal string.
 335 * Returns the length of string.  On buffer overflow, returns 0.
 336 *
 337 * If speed is not important, use snprintf(). It's easy to read the code.
 338 */
 339int num_to_str(char *buf, int size, unsigned long long num, unsigned int width)
 340{
 341        /* put_dec requires 2-byte alignment of the buffer. */
 342        char tmp[sizeof(num) * 3] __aligned(2);
 343        int idx, len;
 344
 345        /* put_dec() may work incorrectly for num = 0 (generate "", not "0") */
 346        if (num <= 9) {
 347                tmp[0] = '0' + num;
 348                len = 1;
 349        } else {
 350                len = put_dec(tmp, num) - tmp;
 351        }
 352
 353        if (len > size || width > size)
 354                return 0;
 355
 356        if (width > len) {
 357                width = width - len;
 358                for (idx = 0; idx < width; idx++)
 359                        buf[idx] = ' ';
 360        } else {
 361                width = 0;
 362        }
 363
 364        for (idx = 0; idx < len; ++idx)
 365                buf[idx + width] = tmp[len - idx - 1];
 366
 367        return len + width;
 368}
 369
 370#define SIGN    1               /* unsigned/signed, must be 1 */
 371#define LEFT    2               /* left justified */
 372#define PLUS    4               /* show plus */
 373#define SPACE   8               /* space if plus */
 374#define ZEROPAD 16              /* pad with zero, must be 16 == '0' - ' ' */
 375#define SMALL   32              /* use lowercase in hex (must be 32 == 0x20) */
 376#define SPECIAL 64              /* prefix hex with "0x", octal with "0" */
 377
 378enum format_type {
 379        FORMAT_TYPE_NONE, /* Just a string part */
 380        FORMAT_TYPE_WIDTH,
 381        FORMAT_TYPE_PRECISION,
 382        FORMAT_TYPE_CHAR,
 383        FORMAT_TYPE_STR,
 384        FORMAT_TYPE_PTR,
 385        FORMAT_TYPE_PERCENT_CHAR,
 386        FORMAT_TYPE_INVALID,
 387        FORMAT_TYPE_LONG_LONG,
 388        FORMAT_TYPE_ULONG,
 389        FORMAT_TYPE_LONG,
 390        FORMAT_TYPE_UBYTE,
 391        FORMAT_TYPE_BYTE,
 392        FORMAT_TYPE_USHORT,
 393        FORMAT_TYPE_SHORT,
 394        FORMAT_TYPE_UINT,
 395        FORMAT_TYPE_INT,
 396        FORMAT_TYPE_SIZE_T,
 397        FORMAT_TYPE_PTRDIFF
 398};
 399
 400struct printf_spec {
 401        unsigned int    type:8;         /* format_type enum */
 402        signed int      field_width:24; /* width of output field */
 403        unsigned int    flags:8;        /* flags to number() */
 404        unsigned int    base:8;         /* number base, 8, 10 or 16 only */
 405        signed int      precision:16;   /* # of digits/chars */
 406} __packed;
 407#define FIELD_WIDTH_MAX ((1 << 23) - 1)
 408#define PRECISION_MAX ((1 << 15) - 1)
 409
 410static noinline_for_stack
 411char *number(char *buf, char *end, unsigned long long num,
 412             struct printf_spec spec)
 413{
 414        /* put_dec requires 2-byte alignment of the buffer. */
 415        char tmp[3 * sizeof(num)] __aligned(2);
 416        char sign;
 417        char locase;
 418        int need_pfx = ((spec.flags & SPECIAL) && spec.base != 10);
 419        int i;
 420        bool is_zero = num == 0LL;
 421        int field_width = spec.field_width;
 422        int precision = spec.precision;
 423
 424        BUILD_BUG_ON(sizeof(struct printf_spec) != 8);
 425
 426        /* locase = 0 or 0x20. ORing digits or letters with 'locase'
 427         * produces same digits or (maybe lowercased) letters */
 428        locase = (spec.flags & SMALL);
 429        if (spec.flags & LEFT)
 430                spec.flags &= ~ZEROPAD;
 431        sign = 0;
 432        if (spec.flags & SIGN) {
 433                if ((signed long long)num < 0) {
 434                        sign = '-';
 435                        num = -(signed long long)num;
 436                        field_width--;
 437                } else if (spec.flags & PLUS) {
 438                        sign = '+';
 439                        field_width--;
 440                } else if (spec.flags & SPACE) {
 441                        sign = ' ';
 442                        field_width--;
 443                }
 444        }
 445        if (need_pfx) {
 446                if (spec.base == 16)
 447                        field_width -= 2;
 448                else if (!is_zero)
 449                        field_width--;
 450        }
 451
 452        /* generate full string in tmp[], in reverse order */
 453        i = 0;
 454        if (num < spec.base)
 455                tmp[i++] = hex_asc_upper[num] | locase;
 456        else if (spec.base != 10) { /* 8 or 16 */
 457                int mask = spec.base - 1;
 458                int shift = 3;
 459
 460                if (spec.base == 16)
 461                        shift = 4;
 462                do {
 463                        tmp[i++] = (hex_asc_upper[((unsigned char)num) & mask] | locase);
 464                        num >>= shift;
 465                } while (num);
 466        } else { /* base 10 */
 467                i = put_dec(tmp, num) - tmp;
 468        }
 469
 470        /* printing 100 using %2d gives "100", not "00" */
 471        if (i > precision)
 472                precision = i;
 473        /* leading space padding */
 474        field_width -= precision;
 475        if (!(spec.flags & (ZEROPAD | LEFT))) {
 476                while (--field_width >= 0) {
 477                        if (buf < end)
 478                                *buf = ' ';
 479                        ++buf;
 480                }
 481        }
 482        /* sign */
 483        if (sign) {
 484                if (buf < end)
 485                        *buf = sign;
 486                ++buf;
 487        }
 488        /* "0x" / "0" prefix */
 489        if (need_pfx) {
 490                if (spec.base == 16 || !is_zero) {
 491                        if (buf < end)
 492                                *buf = '0';
 493                        ++buf;
 494                }
 495                if (spec.base == 16) {
 496                        if (buf < end)
 497                                *buf = ('X' | locase);
 498                        ++buf;
 499                }
 500        }
 501        /* zero or space padding */
 502        if (!(spec.flags & LEFT)) {
 503                char c = ' ' + (spec.flags & ZEROPAD);
 504                BUILD_BUG_ON(' ' + ZEROPAD != '0');
 505                while (--field_width >= 0) {
 506                        if (buf < end)
 507                                *buf = c;
 508                        ++buf;
 509                }
 510        }
 511        /* hmm even more zero padding? */
 512        while (i <= --precision) {
 513                if (buf < end)
 514                        *buf = '0';
 515                ++buf;
 516        }
 517        /* actual digits of result */
 518        while (--i >= 0) {
 519                if (buf < end)
 520                        *buf = tmp[i];
 521                ++buf;
 522        }
 523        /* trailing space padding */
 524        while (--field_width >= 0) {
 525                if (buf < end)
 526                        *buf = ' ';
 527                ++buf;
 528        }
 529
 530        return buf;
 531}
 532
 533static noinline_for_stack
 534char *special_hex_number(char *buf, char *end, unsigned long long num, int size)
 535{
 536        struct printf_spec spec;
 537
 538        spec.type = FORMAT_TYPE_PTR;
 539        spec.field_width = 2 + 2 * size;        /* 0x + hex */
 540        spec.flags = SPECIAL | SMALL | ZEROPAD;
 541        spec.base = 16;
 542        spec.precision = -1;
 543
 544        return number(buf, end, num, spec);
 545}
 546
 547static void move_right(char *buf, char *end, unsigned len, unsigned spaces)
 548{
 549        size_t size;
 550        if (buf >= end) /* nowhere to put anything */
 551                return;
 552        size = end - buf;
 553        if (size <= spaces) {
 554                memset(buf, ' ', size);
 555                return;
 556        }
 557        if (len) {
 558                if (len > size - spaces)
 559                        len = size - spaces;
 560                memmove(buf + spaces, buf, len);
 561        }
 562        memset(buf, ' ', spaces);
 563}
 564
 565/*
 566 * Handle field width padding for a string.
 567 * @buf: current buffer position
 568 * @n: length of string
 569 * @end: end of output buffer
 570 * @spec: for field width and flags
 571 * Returns: new buffer position after padding.
 572 */
 573static noinline_for_stack
 574char *widen_string(char *buf, int n, char *end, struct printf_spec spec)
 575{
 576        unsigned spaces;
 577
 578        if (likely(n >= spec.field_width))
 579                return buf;
 580        /* we want to pad the sucker */
 581        spaces = spec.field_width - n;
 582        if (!(spec.flags & LEFT)) {
 583                move_right(buf - n, end, n, spaces);
 584                return buf + spaces;
 585        }
 586        while (spaces--) {
 587                if (buf < end)
 588                        *buf = ' ';
 589                ++buf;
 590        }
 591        return buf;
 592}
 593
 594static noinline_for_stack
 595char *string(char *buf, char *end, const char *s, struct printf_spec spec)
 596{
 597        int len = 0;
 598        size_t lim = spec.precision;
 599
 600        if ((unsigned long)s < PAGE_SIZE)
 601                s = "(null)";
 602
 603        while (lim--) {
 604                char c = *s++;
 605                if (!c)
 606                        break;
 607                if (buf < end)
 608                        *buf = c;
 609                ++buf;
 610                ++len;
 611        }
 612        return widen_string(buf, len, end, spec);
 613}
 614
 615static noinline_for_stack
 616char *dentry_name(char *buf, char *end, const struct dentry *d, struct printf_spec spec,
 617                  const char *fmt)
 618{
 619        const char *array[4], *s;
 620        const struct dentry *p;
 621        int depth;
 622        int i, n;
 623
 624        switch (fmt[1]) {
 625                case '2': case '3': case '4':
 626                        depth = fmt[1] - '0';
 627                        break;
 628                default:
 629                        depth = 1;
 630        }
 631
 632        rcu_read_lock();
 633        for (i = 0; i < depth; i++, d = p) {
 634                p = READ_ONCE(d->d_parent);
 635                array[i] = READ_ONCE(d->d_name.name);
 636                if (p == d) {
 637                        if (i)
 638                                array[i] = "";
 639                        i++;
 640                        break;
 641                }
 642        }
 643        s = array[--i];
 644        for (n = 0; n != spec.precision; n++, buf++) {
 645                char c = *s++;
 646                if (!c) {
 647                        if (!i)
 648                                break;
 649                        c = '/';
 650                        s = array[--i];
 651                }
 652                if (buf < end)
 653                        *buf = c;
 654        }
 655        rcu_read_unlock();
 656        return widen_string(buf, n, end, spec);
 657}
 658
 659#ifdef CONFIG_BLOCK
 660static noinline_for_stack
 661char *bdev_name(char *buf, char *end, struct block_device *bdev,
 662                struct printf_spec spec, const char *fmt)
 663{
 664        struct gendisk *hd = bdev->bd_disk;
 665        
 666        buf = string(buf, end, hd->disk_name, spec);
 667        if (bdev->bd_part->partno) {
 668                if (isdigit(hd->disk_name[strlen(hd->disk_name)-1])) {
 669                        if (buf < end)
 670                                *buf = 'p';
 671                        buf++;
 672                }
 673                buf = number(buf, end, bdev->bd_part->partno, spec);
 674        }
 675        return buf;
 676}
 677#endif
 678
 679static noinline_for_stack
 680char *symbol_string(char *buf, char *end, void *ptr,
 681                    struct printf_spec spec, const char *fmt)
 682{
 683        unsigned long value;
 684#ifdef CONFIG_KALLSYMS
 685        char sym[KSYM_SYMBOL_LEN];
 686#endif
 687
 688        if (fmt[1] == 'R')
 689                ptr = __builtin_extract_return_addr(ptr);
 690        value = (unsigned long)ptr;
 691
 692#ifdef CONFIG_KALLSYMS
 693        if (*fmt == 'B')
 694                sprint_backtrace(sym, value);
 695        else if (*fmt != 'f' && *fmt != 's')
 696                sprint_symbol(sym, value);
 697        else
 698                sprint_symbol_no_offset(sym, value);
 699
 700        return string(buf, end, sym, spec);
 701#else
 702        return special_hex_number(buf, end, value, sizeof(void *));
 703#endif
 704}
 705
 706static noinline_for_stack
 707char *resource_string(char *buf, char *end, struct resource *res,
 708                      struct printf_spec spec, const char *fmt)
 709{
 710#ifndef IO_RSRC_PRINTK_SIZE
 711#define IO_RSRC_PRINTK_SIZE     6
 712#endif
 713
 714#ifndef MEM_RSRC_PRINTK_SIZE
 715#define MEM_RSRC_PRINTK_SIZE    10
 716#endif
 717        static const struct printf_spec io_spec = {
 718                .base = 16,
 719                .field_width = IO_RSRC_PRINTK_SIZE,
 720                .precision = -1,
 721                .flags = SPECIAL | SMALL | ZEROPAD,
 722        };
 723        static const struct printf_spec mem_spec = {
 724                .base = 16,
 725                .field_width = MEM_RSRC_PRINTK_SIZE,
 726                .precision = -1,
 727                .flags = SPECIAL | SMALL | ZEROPAD,
 728        };
 729        static const struct printf_spec bus_spec = {
 730                .base = 16,
 731                .field_width = 2,
 732                .precision = -1,
 733                .flags = SMALL | ZEROPAD,
 734        };
 735        static const struct printf_spec dec_spec = {
 736                .base = 10,
 737                .precision = -1,
 738                .flags = 0,
 739        };
 740        static const struct printf_spec str_spec = {
 741                .field_width = -1,
 742                .precision = 10,
 743                .flags = LEFT,
 744        };
 745        static const struct printf_spec flag_spec = {
 746                .base = 16,
 747                .precision = -1,
 748                .flags = SPECIAL | SMALL,
 749        };
 750
 751        /* 32-bit res (sizeof==4): 10 chars in dec, 10 in hex ("0x" + 8)
 752         * 64-bit res (sizeof==8): 20 chars in dec, 18 in hex ("0x" + 16) */
 753#define RSRC_BUF_SIZE           ((2 * sizeof(resource_size_t)) + 4)
 754#define FLAG_BUF_SIZE           (2 * sizeof(res->flags))
 755#define DECODED_BUF_SIZE        sizeof("[mem - 64bit pref window disabled]")
 756#define RAW_BUF_SIZE            sizeof("[mem - flags 0x]")
 757        char sym[max(2*RSRC_BUF_SIZE + DECODED_BUF_SIZE,
 758                     2*RSRC_BUF_SIZE + FLAG_BUF_SIZE + RAW_BUF_SIZE)];
 759
 760        char *p = sym, *pend = sym + sizeof(sym);
 761        int decode = (fmt[0] == 'R') ? 1 : 0;
 762        const struct printf_spec *specp;
 763
 764        *p++ = '[';
 765        if (res->flags & IORESOURCE_IO) {
 766                p = string(p, pend, "io  ", str_spec);
 767                specp = &io_spec;
 768        } else if (res->flags & IORESOURCE_MEM) {
 769                p = string(p, pend, "mem ", str_spec);
 770                specp = &mem_spec;
 771        } else if (res->flags & IORESOURCE_IRQ) {
 772                p = string(p, pend, "irq ", str_spec);
 773                specp = &dec_spec;
 774        } else if (res->flags & IORESOURCE_DMA) {
 775                p = string(p, pend, "dma ", str_spec);
 776                specp = &dec_spec;
 777        } else if (res->flags & IORESOURCE_BUS) {
 778                p = string(p, pend, "bus ", str_spec);
 779                specp = &bus_spec;
 780        } else {
 781                p = string(p, pend, "??? ", str_spec);
 782                specp = &mem_spec;
 783                decode = 0;
 784        }
 785        if (decode && res->flags & IORESOURCE_UNSET) {
 786                p = string(p, pend, "size ", str_spec);
 787                p = number(p, pend, resource_size(res), *specp);
 788        } else {
 789                p = number(p, pend, res->start, *specp);
 790                if (res->start != res->end) {
 791                        *p++ = '-';
 792                        p = number(p, pend, res->end, *specp);
 793                }
 794        }
 795        if (decode) {
 796                if (res->flags & IORESOURCE_MEM_64)
 797                        p = string(p, pend, " 64bit", str_spec);
 798                if (res->flags & IORESOURCE_PREFETCH)
 799                        p = string(p, pend, " pref", str_spec);
 800                if (res->flags & IORESOURCE_WINDOW)
 801                        p = string(p, pend, " window", str_spec);
 802                if (res->flags & IORESOURCE_DISABLED)
 803                        p = string(p, pend, " disabled", str_spec);
 804        } else {
 805                p = string(p, pend, " flags ", str_spec);
 806                p = number(p, pend, res->flags, flag_spec);
 807        }
 808        *p++ = ']';
 809        *p = '\0';
 810
 811        return string(buf, end, sym, spec);
 812}
 813
 814static noinline_for_stack
 815char *hex_string(char *buf, char *end, u8 *addr, struct printf_spec spec,
 816                 const char *fmt)
 817{
 818        int i, len = 1;         /* if we pass '%ph[CDN]', field width remains
 819                                   negative value, fallback to the default */
 820        char separator;
 821
 822        if (spec.field_width == 0)
 823                /* nothing to print */
 824                return buf;
 825
 826        if (ZERO_OR_NULL_PTR(addr))
 827                /* NULL pointer */
 828                return string(buf, end, NULL, spec);
 829
 830        switch (fmt[1]) {
 831        case 'C':
 832                separator = ':';
 833                break;
 834        case 'D':
 835                separator = '-';
 836                break;
 837        case 'N':
 838                separator = 0;
 839                break;
 840        default:
 841                separator = ' ';
 842                break;
 843        }
 844
 845        if (spec.field_width > 0)
 846                len = min_t(int, spec.field_width, 64);
 847
 848        for (i = 0; i < len; ++i) {
 849                if (buf < end)
 850                        *buf = hex_asc_hi(addr[i]);
 851                ++buf;
 852                if (buf < end)
 853                        *buf = hex_asc_lo(addr[i]);
 854                ++buf;
 855
 856                if (separator && i != len - 1) {
 857                        if (buf < end)
 858                                *buf = separator;
 859                        ++buf;
 860                }
 861        }
 862
 863        return buf;
 864}
 865
 866static noinline_for_stack
 867char *bitmap_string(char *buf, char *end, unsigned long *bitmap,
 868                    struct printf_spec spec, const char *fmt)
 869{
 870        const int CHUNKSZ = 32;
 871        int nr_bits = max_t(int, spec.field_width, 0);
 872        int i, chunksz;
 873        bool first = true;
 874
 875        /* reused to print numbers */
 876        spec = (struct printf_spec){ .flags = SMALL | ZEROPAD, .base = 16 };
 877
 878        chunksz = nr_bits & (CHUNKSZ - 1);
 879        if (chunksz == 0)
 880                chunksz = CHUNKSZ;
 881
 882        i = ALIGN(nr_bits, CHUNKSZ) - CHUNKSZ;
 883        for (; i >= 0; i -= CHUNKSZ) {
 884                u32 chunkmask, val;
 885                int word, bit;
 886
 887                chunkmask = ((1ULL << chunksz) - 1);
 888                word = i / BITS_PER_LONG;
 889                bit = i % BITS_PER_LONG;
 890                val = (bitmap[word] >> bit) & chunkmask;
 891
 892                if (!first) {
 893                        if (buf < end)
 894                                *buf = ',';
 895                        buf++;
 896                }
 897                first = false;
 898
 899                spec.field_width = DIV_ROUND_UP(chunksz, 4);
 900                buf = number(buf, end, val, spec);
 901
 902                chunksz = CHUNKSZ;
 903        }
 904        return buf;
 905}
 906
 907static noinline_for_stack
 908char *bitmap_list_string(char *buf, char *end, unsigned long *bitmap,
 909                         struct printf_spec spec, const char *fmt)
 910{
 911        int nr_bits = max_t(int, spec.field_width, 0);
 912        /* current bit is 'cur', most recently seen range is [rbot, rtop] */
 913        int cur, rbot, rtop;
 914        bool first = true;
 915
 916        /* reused to print numbers */
 917        spec = (struct printf_spec){ .base = 10 };
 918
 919        rbot = cur = find_first_bit(bitmap, nr_bits);
 920        while (cur < nr_bits) {
 921                rtop = cur;
 922                cur = find_next_bit(bitmap, nr_bits, cur + 1);
 923                if (cur < nr_bits && cur <= rtop + 1)
 924                        continue;
 925
 926                if (!first) {
 927                        if (buf < end)
 928                                *buf = ',';
 929                        buf++;
 930                }
 931                first = false;
 932
 933                buf = number(buf, end, rbot, spec);
 934                if (rbot < rtop) {
 935                        if (buf < end)
 936                                *buf = '-';
 937                        buf++;
 938
 939                        buf = number(buf, end, rtop, spec);
 940                }
 941
 942                rbot = cur;
 943        }
 944        return buf;
 945}
 946
 947static noinline_for_stack
 948char *mac_address_string(char *buf, char *end, u8 *addr,
 949                         struct printf_spec spec, const char *fmt)
 950{
 951        char mac_addr[sizeof("xx:xx:xx:xx:xx:xx")];
 952        char *p = mac_addr;
 953        int i;
 954        char separator;
 955        bool reversed = false;
 956
 957        switch (fmt[1]) {
 958        case 'F':
 959                separator = '-';
 960                break;
 961
 962        case 'R':
 963                reversed = true;
 964                /* fall through */
 965
 966        default:
 967                separator = ':';
 968                break;
 969        }
 970
 971        for (i = 0; i < 6; i++) {
 972                if (reversed)
 973                        p = hex_byte_pack(p, addr[5 - i]);
 974                else
 975                        p = hex_byte_pack(p, addr[i]);
 976
 977                if (fmt[0] == 'M' && i != 5)
 978                        *p++ = separator;
 979        }
 980        *p = '\0';
 981
 982        return string(buf, end, mac_addr, spec);
 983}
 984
 985static noinline_for_stack
 986char *ip4_string(char *p, const u8 *addr, const char *fmt)
 987{
 988        int i;
 989        bool leading_zeros = (fmt[0] == 'i');
 990        int index;
 991        int step;
 992
 993        switch (fmt[2]) {
 994        case 'h':
 995#ifdef __BIG_ENDIAN
 996                index = 0;
 997                step = 1;
 998#else
 999                index = 3;
1000                step = -1;
1001#endif
1002                break;
1003        case 'l':
1004                index = 3;
1005                step = -1;
1006                break;
1007        case 'n':
1008        case 'b':
1009        default:
1010                index = 0;
1011                step = 1;
1012                break;
1013        }
1014        for (i = 0; i < 4; i++) {
1015                char temp[4] __aligned(2);      /* hold each IP quad in reverse order */
1016                int digits = put_dec_trunc8(temp, addr[index]) - temp;
1017                if (leading_zeros) {
1018                        if (digits < 3)
1019                                *p++ = '0';
1020                        if (digits < 2)
1021                                *p++ = '0';
1022                }
1023                /* reverse the digits in the quad */
1024                while (digits--)
1025                        *p++ = temp[digits];
1026                if (i < 3)
1027                        *p++ = '.';
1028                index += step;
1029        }
1030        *p = '\0';
1031
1032        return p;
1033}
1034
1035static noinline_for_stack
1036char *ip6_compressed_string(char *p, const char *addr)
1037{
1038        int i, j, range;
1039        unsigned char zerolength[8];
1040        int longest = 1;
1041        int colonpos = -1;
1042        u16 word;
1043        u8 hi, lo;
1044        bool needcolon = false;
1045        bool useIPv4;
1046        struct in6_addr in6;
1047
1048        memcpy(&in6, addr, sizeof(struct in6_addr));
1049
1050        useIPv4 = ipv6_addr_v4mapped(&in6) || ipv6_addr_is_isatap(&in6);
1051
1052        memset(zerolength, 0, sizeof(zerolength));
1053
1054        if (useIPv4)
1055                range = 6;
1056        else
1057                range = 8;
1058
1059        /* find position of longest 0 run */
1060        for (i = 0; i < range; i++) {
1061                for (j = i; j < range; j++) {
1062                        if (in6.s6_addr16[j] != 0)
1063                                break;
1064                        zerolength[i]++;
1065                }
1066        }
1067        for (i = 0; i < range; i++) {
1068                if (zerolength[i] > longest) {
1069                        longest = zerolength[i];
1070                        colonpos = i;
1071                }
1072        }
1073        if (longest == 1)               /* don't compress a single 0 */
1074                colonpos = -1;
1075
1076        /* emit address */
1077        for (i = 0; i < range; i++) {
1078                if (i == colonpos) {
1079                        if (needcolon || i == 0)
1080                                *p++ = ':';
1081                        *p++ = ':';
1082                        needcolon = false;
1083                        i += longest - 1;
1084                        continue;
1085                }
1086                if (needcolon) {
1087                        *p++ = ':';
1088                        needcolon = false;
1089                }
1090                /* hex u16 without leading 0s */
1091                word = ntohs(in6.s6_addr16[i]);
1092                hi = word >> 8;
1093                lo = word & 0xff;
1094                if (hi) {
1095                        if (hi > 0x0f)
1096                                p = hex_byte_pack(p, hi);
1097                        else
1098                                *p++ = hex_asc_lo(hi);
1099                        p = hex_byte_pack(p, lo);
1100                }
1101                else if (lo > 0x0f)
1102                        p = hex_byte_pack(p, lo);
1103                else
1104                        *p++ = hex_asc_lo(lo);
1105                needcolon = true;
1106        }
1107
1108        if (useIPv4) {
1109                if (needcolon)
1110                        *p++ = ':';
1111                p = ip4_string(p, &in6.s6_addr[12], "I4");
1112        }
1113        *p = '\0';
1114
1115        return p;
1116}
1117
1118static noinline_for_stack
1119char *ip6_string(char *p, const char *addr, const char *fmt)
1120{
1121        int i;
1122
1123        for (i = 0; i < 8; i++) {
1124                p = hex_byte_pack(p, *addr++);
1125                p = hex_byte_pack(p, *addr++);
1126                if (fmt[0] == 'I' && i != 7)
1127                        *p++ = ':';
1128        }
1129        *p = '\0';
1130
1131        return p;
1132}
1133
1134static noinline_for_stack
1135char *ip6_addr_string(char *buf, char *end, const u8 *addr,
1136                      struct printf_spec spec, const char *fmt)
1137{
1138        char ip6_addr[sizeof("xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255")];
1139
1140        if (fmt[0] == 'I' && fmt[2] == 'c')
1141                ip6_compressed_string(ip6_addr, addr);
1142        else
1143                ip6_string(ip6_addr, addr, fmt);
1144
1145        return string(buf, end, ip6_addr, spec);
1146}
1147
1148static noinline_for_stack
1149char *ip4_addr_string(char *buf, char *end, const u8 *addr,
1150                      struct printf_spec spec, const char *fmt)
1151{
1152        char ip4_addr[sizeof("255.255.255.255")];
1153
1154        ip4_string(ip4_addr, addr, fmt);
1155
1156        return string(buf, end, ip4_addr, spec);
1157}
1158
1159static noinline_for_stack
1160char *ip6_addr_string_sa(char *buf, char *end, const struct sockaddr_in6 *sa,
1161                         struct printf_spec spec, const char *fmt)
1162{
1163        bool have_p = false, have_s = false, have_f = false, have_c = false;
1164        char ip6_addr[sizeof("[xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255]") +
1165                      sizeof(":12345") + sizeof("/123456789") +
1166                      sizeof("%1234567890")];
1167        char *p = ip6_addr, *pend = ip6_addr + sizeof(ip6_addr);
1168        const u8 *addr = (const u8 *) &sa->sin6_addr;
1169        char fmt6[2] = { fmt[0], '6' };
1170        u8 off = 0;
1171
1172        fmt++;
1173        while (isalpha(*++fmt)) {
1174                switch (*fmt) {
1175                case 'p':
1176                        have_p = true;
1177                        break;
1178                case 'f':
1179                        have_f = true;
1180                        break;
1181                case 's':
1182                        have_s = true;
1183                        break;
1184                case 'c':
1185                        have_c = true;
1186                        break;
1187                }
1188        }
1189
1190        if (have_p || have_s || have_f) {
1191                *p = '[';
1192                off = 1;
1193        }
1194
1195        if (fmt6[0] == 'I' && have_c)
1196                p = ip6_compressed_string(ip6_addr + off, addr);
1197        else
1198                p = ip6_string(ip6_addr + off, addr, fmt6);
1199
1200        if (have_p || have_s || have_f)
1201                *p++ = ']';
1202
1203        if (have_p) {
1204                *p++ = ':';
1205                p = number(p, pend, ntohs(sa->sin6_port), spec);
1206        }
1207        if (have_f) {
1208                *p++ = '/';
1209                p = number(p, pend, ntohl(sa->sin6_flowinfo &
1210                                          IPV6_FLOWINFO_MASK), spec);
1211        }
1212        if (have_s) {
1213                *p++ = '%';
1214                p = number(p, pend, sa->sin6_scope_id, spec);
1215        }
1216        *p = '\0';
1217
1218        return string(buf, end, ip6_addr, spec);
1219}
1220
1221static noinline_for_stack
1222char *ip4_addr_string_sa(char *buf, char *end, const struct sockaddr_in *sa,
1223                         struct printf_spec spec, const char *fmt)
1224{
1225        bool have_p = false;
1226        char *p, ip4_addr[sizeof("255.255.255.255") + sizeof(":12345")];
1227        char *pend = ip4_addr + sizeof(ip4_addr);
1228        const u8 *addr = (const u8 *) &sa->sin_addr.s_addr;
1229        char fmt4[3] = { fmt[0], '4', 0 };
1230
1231        fmt++;
1232        while (isalpha(*++fmt)) {
1233                switch (*fmt) {
1234                case 'p':
1235                        have_p = true;
1236                        break;
1237                case 'h':
1238                case 'l':
1239                case 'n':
1240                case 'b':
1241                        fmt4[2] = *fmt;
1242                        break;
1243                }
1244        }
1245
1246        p = ip4_string(ip4_addr, addr, fmt4);
1247        if (have_p) {
1248                *p++ = ':';
1249                p = number(p, pend, ntohs(sa->sin_port), spec);
1250        }
1251        *p = '\0';
1252
1253        return string(buf, end, ip4_addr, spec);
1254}
1255
1256static noinline_for_stack
1257char *escaped_string(char *buf, char *end, u8 *addr, struct printf_spec spec,
1258                     const char *fmt)
1259{
1260        bool found = true;
1261        int count = 1;
1262        unsigned int flags = 0;
1263        int len;
1264
1265        if (spec.field_width == 0)
1266                return buf;                             /* nothing to print */
1267
1268        if (ZERO_OR_NULL_PTR(addr))
1269                return string(buf, end, NULL, spec);    /* NULL pointer */
1270
1271
1272        do {
1273                switch (fmt[count++]) {
1274                case 'a':
1275                        flags |= ESCAPE_ANY;
1276                        break;
1277                case 'c':
1278                        flags |= ESCAPE_SPECIAL;
1279                        break;
1280                case 'h':
1281                        flags |= ESCAPE_HEX;
1282                        break;
1283                case 'n':
1284                        flags |= ESCAPE_NULL;
1285                        break;
1286                case 'o':
1287                        flags |= ESCAPE_OCTAL;
1288                        break;
1289                case 'p':
1290                        flags |= ESCAPE_NP;
1291                        break;
1292                case 's':
1293                        flags |= ESCAPE_SPACE;
1294                        break;
1295                default:
1296                        found = false;
1297                        break;
1298                }
1299        } while (found);
1300
1301        if (!flags)
1302                flags = ESCAPE_ANY_NP;
1303
1304        len = spec.field_width < 0 ? 1 : spec.field_width;
1305
1306        /*
1307         * string_escape_mem() writes as many characters as it can to
1308         * the given buffer, and returns the total size of the output
1309         * had the buffer been big enough.
1310         */
1311        buf += string_escape_mem(addr, len, buf, buf < end ? end - buf : 0, flags, NULL);
1312
1313        return buf;
1314}
1315
1316static noinline_for_stack
1317char *uuid_string(char *buf, char *end, const u8 *addr,
1318                  struct printf_spec spec, const char *fmt)
1319{
1320        char uuid[UUID_STRING_LEN + 1];
1321        char *p = uuid;
1322        int i;
1323        const u8 *index = uuid_index;
1324        bool uc = false;
1325
1326        switch (*(++fmt)) {
1327        case 'L':
1328                uc = true;              /* fall-through */
1329        case 'l':
1330                index = guid_index;
1331                break;
1332        case 'B':
1333                uc = true;
1334                break;
1335        }
1336
1337        for (i = 0; i < 16; i++) {
1338                if (uc)
1339                        p = hex_byte_pack_upper(p, addr[index[i]]);
1340                else
1341                        p = hex_byte_pack(p, addr[index[i]]);
1342                switch (i) {
1343                case 3:
1344                case 5:
1345                case 7:
1346                case 9:
1347                        *p++ = '-';
1348                        break;
1349                }
1350        }
1351
1352        *p = 0;
1353
1354        return string(buf, end, uuid, spec);
1355}
1356
1357int kptr_restrict __read_mostly;
1358
1359static noinline_for_stack
1360char *restricted_pointer(char *buf, char *end, const void *ptr,
1361                         struct printf_spec spec)
1362{
1363        spec.base = 16;
1364        spec.flags |= SMALL;
1365        if (spec.field_width == -1) {
1366                spec.field_width = 2 * sizeof(ptr);
1367                spec.flags |= ZEROPAD;
1368        }
1369
1370        switch (kptr_restrict) {
1371        case 0:
1372                /* Always print %pK values */
1373                break;
1374        case 1: {
1375                const struct cred *cred;
1376
1377                /*
1378                 * kptr_restrict==1 cannot be used in IRQ context
1379                 * because its test for CAP_SYSLOG would be meaningless.
1380                 */
1381                if (in_irq() || in_serving_softirq() || in_nmi())
1382                        return string(buf, end, "pK-error", spec);
1383
1384                /*
1385                 * Only print the real pointer value if the current
1386                 * process has CAP_SYSLOG and is running with the
1387                 * same credentials it started with. This is because
1388                 * access to files is checked at open() time, but %pK
1389                 * checks permission at read() time. We don't want to
1390                 * leak pointer values if a binary opens a file using
1391                 * %pK and then elevates privileges before reading it.
1392                 */
1393                cred = current_cred();
1394                if (!has_capability_noaudit(current, CAP_SYSLOG) ||
1395                    !uid_eq(cred->euid, cred->uid) ||
1396                    !gid_eq(cred->egid, cred->gid))
1397                        ptr = NULL;
1398                break;
1399        }
1400        case 2:
1401        default:
1402                /* Always print 0's for %pK */
1403                ptr = NULL;
1404                break;
1405        }
1406
1407        return number(buf, end, (unsigned long)ptr, spec);
1408}
1409
1410static noinline_for_stack
1411char *netdev_bits(char *buf, char *end, const void *addr, const char *fmt)
1412{
1413        unsigned long long num;
1414        int size;
1415
1416        switch (fmt[1]) {
1417        case 'F':
1418                num = *(const netdev_features_t *)addr;
1419                size = sizeof(netdev_features_t);
1420                break;
1421        default:
1422                num = (unsigned long)addr;
1423                size = sizeof(unsigned long);
1424                break;
1425        }
1426
1427        return special_hex_number(buf, end, num, size);
1428}
1429
1430static noinline_for_stack
1431char *address_val(char *buf, char *end, const void *addr, const char *fmt)
1432{
1433        unsigned long long num;
1434        int size;
1435
1436        switch (fmt[1]) {
1437        case 'd':
1438                num = *(const dma_addr_t *)addr;
1439                size = sizeof(dma_addr_t);
1440                break;
1441        case 'p':
1442        default:
1443                num = *(const phys_addr_t *)addr;
1444                size = sizeof(phys_addr_t);
1445                break;
1446        }
1447
1448        return special_hex_number(buf, end, num, size);
1449}
1450
1451static noinline_for_stack
1452char *clock(char *buf, char *end, struct clk *clk, struct printf_spec spec,
1453            const char *fmt)
1454{
1455        if (!IS_ENABLED(CONFIG_HAVE_CLK) || !clk)
1456                return string(buf, end, NULL, spec);
1457
1458        switch (fmt[1]) {
1459        case 'r':
1460                return number(buf, end, clk_get_rate(clk), spec);
1461
1462        case 'n':
1463        default:
1464#ifdef CONFIG_COMMON_CLK
1465                return string(buf, end, __clk_get_name(clk), spec);
1466#else
1467                return special_hex_number(buf, end, (unsigned long)clk, sizeof(unsigned long));
1468#endif
1469        }
1470}
1471
1472static
1473char *format_flags(char *buf, char *end, unsigned long flags,
1474                                        const struct trace_print_flags *names)
1475{
1476        unsigned long mask;
1477        const struct printf_spec strspec = {
1478                .field_width = -1,
1479                .precision = -1,
1480        };
1481        const struct printf_spec numspec = {
1482                .flags = SPECIAL|SMALL,
1483                .field_width = -1,
1484                .precision = -1,
1485                .base = 16,
1486        };
1487
1488        for ( ; flags && names->name; names++) {
1489                mask = names->mask;
1490                if ((flags & mask) != mask)
1491                        continue;
1492
1493                buf = string(buf, end, names->name, strspec);
1494
1495                flags &= ~mask;
1496                if (flags) {
1497                        if (buf < end)
1498                                *buf = '|';
1499                        buf++;
1500                }
1501        }
1502
1503        if (flags)
1504                buf = number(buf, end, flags, numspec);
1505
1506        return buf;
1507}
1508
1509static noinline_for_stack
1510char *flags_string(char *buf, char *end, void *flags_ptr, const char *fmt)
1511{
1512        unsigned long flags;
1513        const struct trace_print_flags *names;
1514
1515        switch (fmt[1]) {
1516        case 'p':
1517                flags = *(unsigned long *)flags_ptr;
1518                /* Remove zone id */
1519                flags &= (1UL << NR_PAGEFLAGS) - 1;
1520                names = pageflag_names;
1521                break;
1522        case 'v':
1523                flags = *(unsigned long *)flags_ptr;
1524                names = vmaflag_names;
1525                break;
1526        case 'g':
1527                flags = *(gfp_t *)flags_ptr;
1528                names = gfpflag_names;
1529                break;
1530        default:
1531                WARN_ONCE(1, "Unsupported flags modifier: %c\n", fmt[1]);
1532                return buf;
1533        }
1534
1535        return format_flags(buf, end, flags, names);
1536}
1537
1538static const char *device_node_name_for_depth(const struct device_node *np, int depth)
1539{
1540        for ( ; np && depth; depth--)
1541                np = np->parent;
1542
1543        return kbasename(np->full_name);
1544}
1545
1546static noinline_for_stack
1547char *device_node_gen_full_name(const struct device_node *np, char *buf, char *end)
1548{
1549        int depth;
1550        const struct device_node *parent = np->parent;
1551        static const struct printf_spec strspec = {
1552                .field_width = -1,
1553                .precision = -1,
1554        };
1555
1556        /* special case for root node */
1557        if (!parent)
1558                return string(buf, end, "/", strspec);
1559
1560        for (depth = 0; parent->parent; depth++)
1561                parent = parent->parent;
1562
1563        for ( ; depth >= 0; depth--) {
1564                buf = string(buf, end, "/", strspec);
1565                buf = string(buf, end, device_node_name_for_depth(np, depth),
1566                             strspec);
1567        }
1568        return buf;
1569}
1570
1571static noinline_for_stack
1572char *device_node_string(char *buf, char *end, struct device_node *dn,
1573                         struct printf_spec spec, const char *fmt)
1574{
1575        char tbuf[sizeof("xxxx") + 1];
1576        const char *p;
1577        int ret;
1578        char *buf_start = buf;
1579        struct property *prop;
1580        bool has_mult, pass;
1581        static const struct printf_spec num_spec = {
1582                .flags = SMALL,
1583                .field_width = -1,
1584                .precision = -1,
1585                .base = 10,
1586        };
1587
1588        struct printf_spec str_spec = spec;
1589        str_spec.field_width = -1;
1590
1591        if (!IS_ENABLED(CONFIG_OF))
1592                return string(buf, end, "(!OF)", spec);
1593
1594        if ((unsigned long)dn < PAGE_SIZE)
1595                return string(buf, end, "(null)", spec);
1596
1597        /* simple case without anything any more format specifiers */
1598        fmt++;
1599        if (fmt[0] == '\0' || strcspn(fmt,"fnpPFcC") > 0)
1600                fmt = "f";
1601
1602        for (pass = false; strspn(fmt,"fnpPFcC"); fmt++, pass = true) {
1603                if (pass) {
1604                        if (buf < end)
1605                                *buf = ':';
1606                        buf++;
1607                }
1608
1609                switch (*fmt) {
1610                case 'f':       /* full_name */
1611                        buf = device_node_gen_full_name(dn, buf, end);
1612                        break;
1613                case 'n':       /* name */
1614                        buf = string(buf, end, dn->name, str_spec);
1615                        break;
1616                case 'p':       /* phandle */
1617                        buf = number(buf, end, (unsigned int)dn->phandle, num_spec);
1618                        break;
1619                case 'P':       /* path-spec */
1620                        p = kbasename(of_node_full_name(dn));
1621                        if (!p[1])
1622                                p = "/";
1623                        buf = string(buf, end, p, str_spec);
1624                        break;
1625                case 'F':       /* flags */
1626                        tbuf[0] = of_node_check_flag(dn, OF_DYNAMIC) ? 'D' : '-';
1627                        tbuf[1] = of_node_check_flag(dn, OF_DETACHED) ? 'd' : '-';
1628                        tbuf[2] = of_node_check_flag(dn, OF_POPULATED) ? 'P' : '-';
1629                        tbuf[3] = of_node_check_flag(dn, OF_POPULATED_BUS) ? 'B' : '-';
1630                        tbuf[4] = 0;
1631                        buf = string(buf, end, tbuf, str_spec);
1632                        break;
1633                case 'c':       /* major compatible string */
1634                        ret = of_property_read_string(dn, "compatible", &p);
1635                        if (!ret)
1636                                buf = string(buf, end, p, str_spec);
1637                        break;
1638                case 'C':       /* full compatible string */
1639                        has_mult = false;
1640                        of_property_for_each_string(dn, "compatible", prop, p) {
1641                                if (has_mult)
1642                                        buf = string(buf, end, ",", str_spec);
1643                                buf = string(buf, end, "\"", str_spec);
1644                                buf = string(buf, end, p, str_spec);
1645                                buf = string(buf, end, "\"", str_spec);
1646
1647                                has_mult = true;
1648                        }
1649                        break;
1650                default:
1651                        break;
1652                }
1653        }
1654
1655        return widen_string(buf, buf - buf_start, end, spec);
1656}
1657
1658static noinline_for_stack
1659char *pointer_string(char *buf, char *end, const void *ptr,
1660                     struct printf_spec spec)
1661{
1662        spec.base = 16;
1663        spec.flags |= SMALL;
1664        if (spec.field_width == -1) {
1665                spec.field_width = 2 * sizeof(ptr);
1666                spec.flags |= ZEROPAD;
1667        }
1668
1669        return number(buf, end, (unsigned long int)ptr, spec);
1670}
1671
1672static DEFINE_STATIC_KEY_TRUE(not_filled_random_ptr_key);
1673static siphash_key_t ptr_key __read_mostly;
1674
1675static void enable_ptr_key_workfn(struct work_struct *work)
1676{
1677        get_random_bytes(&ptr_key, sizeof(ptr_key));
1678        /* Needs to run from preemptible context */
1679        static_branch_disable(&not_filled_random_ptr_key);
1680}
1681
1682static DECLARE_WORK(enable_ptr_key_work, enable_ptr_key_workfn);
1683
1684static void fill_random_ptr_key(struct random_ready_callback *unused)
1685{
1686        /* This may be in an interrupt handler. */
1687        queue_work(system_unbound_wq, &enable_ptr_key_work);
1688}
1689
1690static struct random_ready_callback random_ready = {
1691        .func = fill_random_ptr_key
1692};
1693
1694static int __init initialize_ptr_random(void)
1695{
1696        int ret = add_random_ready_callback(&random_ready);
1697
1698        if (!ret) {
1699                return 0;
1700        } else if (ret == -EALREADY) {
1701                /* This is in preemptible context */
1702                enable_ptr_key_workfn(&enable_ptr_key_work);
1703                return 0;
1704        }
1705
1706        return ret;
1707}
1708early_initcall(initialize_ptr_random);
1709
1710/* Maps a pointer to a 32 bit unique identifier. */
1711static char *ptr_to_id(char *buf, char *end, void *ptr, struct printf_spec spec)
1712{
1713        unsigned long hashval;
1714        const int default_width = 2 * sizeof(ptr);
1715
1716        if (static_branch_unlikely(&not_filled_random_ptr_key)) {
1717                spec.field_width = default_width;
1718                /* string length must be less than default_width */
1719                return string(buf, end, "(ptrval)", spec);
1720        }
1721
1722#ifdef CONFIG_64BIT
1723        hashval = (unsigned long)siphash_1u64((u64)ptr, &ptr_key);
1724        /*
1725         * Mask off the first 32 bits, this makes explicit that we have
1726         * modified the address (and 32 bits is plenty for a unique ID).
1727         */
1728        hashval = hashval & 0xffffffff;
1729#else
1730        hashval = (unsigned long)siphash_1u32((u32)ptr, &ptr_key);
1731#endif
1732
1733        spec.flags |= SMALL;
1734        if (spec.field_width == -1) {
1735                spec.field_width = default_width;
1736                spec.flags |= ZEROPAD;
1737        }
1738        spec.base = 16;
1739
1740        return number(buf, end, hashval, spec);
1741}
1742
1743/*
1744 * Show a '%p' thing.  A kernel extension is that the '%p' is followed
1745 * by an extra set of alphanumeric characters that are extended format
1746 * specifiers.
1747 *
1748 * Please update scripts/checkpatch.pl when adding/removing conversion
1749 * characters.  (Search for "check for vsprintf extension").
1750 *
1751 * Right now we handle:
1752 *
1753 * - 'F' For symbolic function descriptor pointers with offset
1754 * - 'f' For simple symbolic function names without offset
1755 * - 'S' For symbolic direct pointers with offset
1756 * - 's' For symbolic direct pointers without offset
1757 * - '[FfSs]R' as above with __builtin_extract_return_addr() translation
1758 * - 'B' For backtraced symbolic direct pointers with offset
1759 * - 'R' For decoded struct resource, e.g., [mem 0x0-0x1f 64bit pref]
1760 * - 'r' For raw struct resource, e.g., [mem 0x0-0x1f flags 0x201]
1761 * - 'b[l]' For a bitmap, the number of bits is determined by the field
1762 *       width which must be explicitly specified either as part of the
1763 *       format string '%32b[l]' or through '%*b[l]', [l] selects
1764 *       range-list format instead of hex format
1765 * - 'M' For a 6-byte MAC address, it prints the address in the
1766 *       usual colon-separated hex notation
1767 * - 'm' For a 6-byte MAC address, it prints the hex address without colons
1768 * - 'MF' For a 6-byte MAC FDDI address, it prints the address
1769 *       with a dash-separated hex notation
1770 * - '[mM]R' For a 6-byte MAC address, Reverse order (Bluetooth)
1771 * - 'I' [46] for IPv4/IPv6 addresses printed in the usual way
1772 *       IPv4 uses dot-separated decimal without leading 0's (1.2.3.4)
1773 *       IPv6 uses colon separated network-order 16 bit hex with leading 0's
1774 *       [S][pfs]
1775 *       Generic IPv4/IPv6 address (struct sockaddr *) that falls back to
1776 *       [4] or [6] and is able to print port [p], flowinfo [f], scope [s]
1777 * - 'i' [46] for 'raw' IPv4/IPv6 addresses
1778 *       IPv6 omits the colons (01020304...0f)
1779 *       IPv4 uses dot-separated decimal with leading 0's (010.123.045.006)
1780 *       [S][pfs]
1781 *       Generic IPv4/IPv6 address (struct sockaddr *) that falls back to
1782 *       [4] or [6] and is able to print port [p], flowinfo [f], scope [s]
1783 * - '[Ii][4S][hnbl]' IPv4 addresses in host, network, big or little endian order
1784 * - 'I[6S]c' for IPv6 addresses printed as specified by
1785 *       http://tools.ietf.org/html/rfc5952
1786 * - 'E[achnops]' For an escaped buffer, where rules are defined by combination
1787 *                of the following flags (see string_escape_mem() for the
1788 *                details):
1789 *                  a - ESCAPE_ANY
1790 *                  c - ESCAPE_SPECIAL
1791 *                  h - ESCAPE_HEX
1792 *                  n - ESCAPE_NULL
1793 *                  o - ESCAPE_OCTAL
1794 *                  p - ESCAPE_NP
1795 *                  s - ESCAPE_SPACE
1796 *                By default ESCAPE_ANY_NP is used.
1797 * - 'U' For a 16 byte UUID/GUID, it prints the UUID/GUID in the form
1798 *       "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx"
1799 *       Options for %pU are:
1800 *         b big endian lower case hex (default)
1801 *         B big endian UPPER case hex
1802 *         l little endian lower case hex
1803 *         L little endian UPPER case hex
1804 *           big endian output byte order is:
1805 *             [0][1][2][3]-[4][5]-[6][7]-[8][9]-[10][11][12][13][14][15]
1806 *           little endian output byte order is:
1807 *             [3][2][1][0]-[5][4]-[7][6]-[8][9]-[10][11][12][13][14][15]
1808 * - 'V' For a struct va_format which contains a format string * and va_list *,
1809 *       call vsnprintf(->format, *->va_list).
1810 *       Implements a "recursive vsnprintf".
1811 *       Do not use this feature without some mechanism to verify the
1812 *       correctness of the format string and va_list arguments.
1813 * - 'K' For a kernel pointer that should be hidden from unprivileged users
1814 * - 'NF' For a netdev_features_t
1815 * - 'h[CDN]' For a variable-length buffer, it prints it as a hex string with
1816 *            a certain separator (' ' by default):
1817 *              C colon
1818 *              D dash
1819 *              N no separator
1820 *            The maximum supported length is 64 bytes of the input. Consider
1821 *            to use print_hex_dump() for the larger input.
1822 * - 'a[pd]' For address types [p] phys_addr_t, [d] dma_addr_t and derivatives
1823 *           (default assumed to be phys_addr_t, passed by reference)
1824 * - 'd[234]' For a dentry name (optionally 2-4 last components)
1825 * - 'D[234]' Same as 'd' but for a struct file
1826 * - 'g' For block_device name (gendisk + partition number)
1827 * - 'C' For a clock, it prints the name (Common Clock Framework) or address
1828 *       (legacy clock framework) of the clock
1829 * - 'Cn' For a clock, it prints the name (Common Clock Framework) or address
1830 *        (legacy clock framework) of the clock
1831 * - 'Cr' For a clock, it prints the current rate of the clock
1832 * - 'G' For flags to be printed as a collection of symbolic strings that would
1833 *       construct the specific value. Supported flags given by option:
1834 *       p page flags (see struct page) given as pointer to unsigned long
1835 *       g gfp flags (GFP_* and __GFP_*) given as pointer to gfp_t
1836 *       v vma flags (VM_*) given as pointer to unsigned long
1837 * - 'O' For a kobject based struct. Must be one of the following:
1838 *       - 'OF[fnpPcCF]'  For a device tree object
1839 *                        Without any optional arguments prints the full_name
1840 *                        f device node full_name
1841 *                        n device node name
1842 *                        p device node phandle
1843 *                        P device node path spec (name + @unit)
1844 *                        F device node flags
1845 *                        c major compatible string
1846 *                        C full compatible string
1847 *
1848 * - 'x' For printing the address. Equivalent to "%lx".
1849 *
1850 * ** When making changes please also update:
1851 *      Documentation/core-api/printk-formats.rst
1852 *
1853 * Note: The difference between 'S' and 'F' is that on ia64 and ppc64
1854 * function pointers are really function descriptors, which contain a
1855 * pointer to the real address.
1856 *
1857 * Note: The default behaviour (unadorned %p) is to hash the address,
1858 * rendering it useful as a unique identifier.
1859 */
1860static noinline_for_stack
1861char *pointer(const char *fmt, char *buf, char *end, void *ptr,
1862              struct printf_spec spec)
1863{
1864        const int default_width = 2 * sizeof(void *);
1865
1866        if (!ptr && *fmt != 'K' && *fmt != 'x') {
1867                /*
1868                 * Print (null) with the same width as a pointer so it makes
1869                 * tabular output look nice.
1870                 */
1871                if (spec.field_width == -1)
1872                        spec.field_width = default_width;
1873                return string(buf, end, "(null)", spec);
1874        }
1875
1876        switch (*fmt) {
1877        case 'F':
1878        case 'f':
1879        case 'S':
1880        case 's':
1881                ptr = dereference_symbol_descriptor(ptr);
1882                /* Fallthrough */
1883        case 'B':
1884                return symbol_string(buf, end, ptr, spec, fmt);
1885        case 'R':
1886        case 'r':
1887                return resource_string(buf, end, ptr, spec, fmt);
1888        case 'h':
1889                return hex_string(buf, end, ptr, spec, fmt);
1890        case 'b':
1891                switch (fmt[1]) {
1892                case 'l':
1893                        return bitmap_list_string(buf, end, ptr, spec, fmt);
1894                default:
1895                        return bitmap_string(buf, end, ptr, spec, fmt);
1896                }
1897        case 'M':                       /* Colon separated: 00:01:02:03:04:05 */
1898        case 'm':                       /* Contiguous: 000102030405 */
1899                                        /* [mM]F (FDDI) */
1900                                        /* [mM]R (Reverse order; Bluetooth) */
1901                return mac_address_string(buf, end, ptr, spec, fmt);
1902        case 'I':                       /* Formatted IP supported
1903                                         * 4:   1.2.3.4
1904                                         * 6:   0001:0203:...:0708
1905                                         * 6c:  1::708 or 1::1.2.3.4
1906                                         */
1907        case 'i':                       /* Contiguous:
1908                                         * 4:   001.002.003.004
1909                                         * 6:   000102...0f
1910                                         */
1911                switch (fmt[1]) {
1912                case '6':
1913                        return ip6_addr_string(buf, end, ptr, spec, fmt);
1914                case '4':
1915                        return ip4_addr_string(buf, end, ptr, spec, fmt);
1916                case 'S': {
1917                        const union {
1918                                struct sockaddr         raw;
1919                                struct sockaddr_in      v4;
1920                                struct sockaddr_in6     v6;
1921                        } *sa = ptr;
1922
1923                        switch (sa->raw.sa_family) {
1924                        case AF_INET:
1925                                return ip4_addr_string_sa(buf, end, &sa->v4, spec, fmt);
1926                        case AF_INET6:
1927                                return ip6_addr_string_sa(buf, end, &sa->v6, spec, fmt);
1928                        default:
1929                                return string(buf, end, "(invalid address)", spec);
1930                        }}
1931                }
1932                break;
1933        case 'E':
1934                return escaped_string(buf, end, ptr, spec, fmt);
1935        case 'U':
1936                return uuid_string(buf, end, ptr, spec, fmt);
1937        case 'V':
1938                {
1939                        va_list va;
1940
1941                        va_copy(va, *((struct va_format *)ptr)->va);
1942                        buf += vsnprintf(buf, end > buf ? end - buf : 0,
1943                                         ((struct va_format *)ptr)->fmt, va);
1944                        va_end(va);
1945                        return buf;
1946                }
1947        case 'K':
1948                if (!kptr_restrict)
1949                        break;
1950                return restricted_pointer(buf, end, ptr, spec);
1951        case 'N':
1952                return netdev_bits(buf, end, ptr, fmt);
1953        case 'a':
1954                return address_val(buf, end, ptr, fmt);
1955        case 'd':
1956                return dentry_name(buf, end, ptr, spec, fmt);
1957        case 'C':
1958                return clock(buf, end, ptr, spec, fmt);
1959        case 'D':
1960                return dentry_name(buf, end,
1961                                   ((const struct file *)ptr)->f_path.dentry,
1962                                   spec, fmt);
1963#ifdef CONFIG_BLOCK
1964        case 'g':
1965                return bdev_name(buf, end, ptr, spec, fmt);
1966#endif
1967
1968        case 'G':
1969                return flags_string(buf, end, ptr, fmt);
1970        case 'O':
1971                switch (fmt[1]) {
1972                case 'F':
1973                        return device_node_string(buf, end, ptr, spec, fmt + 1);
1974                }
1975        case 'x':
1976                return pointer_string(buf, end, ptr, spec);
1977        }
1978
1979        /* default is to _not_ leak addresses, hash before printing */
1980        return ptr_to_id(buf, end, ptr, spec);
1981}
1982
1983/*
1984 * Helper function to decode printf style format.
1985 * Each call decode a token from the format and return the
1986 * number of characters read (or likely the delta where it wants
1987 * to go on the next call).
1988 * The decoded token is returned through the parameters
1989 *
1990 * 'h', 'l', or 'L' for integer fields
1991 * 'z' support added 23/7/1999 S.H.
1992 * 'z' changed to 'Z' --davidm 1/25/99
1993 * 'Z' changed to 'z' --adobriyan 2017-01-25
1994 * 't' added for ptrdiff_t
1995 *
1996 * @fmt: the format string
1997 * @type of the token returned
1998 * @flags: various flags such as +, -, # tokens..
1999 * @field_width: overwritten width
2000 * @base: base of the number (octal, hex, ...)
2001 * @precision: precision of a number
2002 * @qualifier: qualifier of a number (long, size_t, ...)
2003 */
2004static noinline_for_stack
2005int format_decode(const char *fmt, struct printf_spec *spec)
2006{
2007        const char *start = fmt;
2008        char qualifier;
2009
2010        /* we finished early by reading the field width */
2011        if (spec->type == FORMAT_TYPE_WIDTH) {
2012                if (spec->field_width < 0) {
2013                        spec->field_width = -spec->field_width;
2014                        spec->flags |= LEFT;
2015                }
2016                spec->type = FORMAT_TYPE_NONE;
2017                goto precision;
2018        }
2019
2020        /* we finished early by reading the precision */
2021        if (spec->type == FORMAT_TYPE_PRECISION) {
2022                if (spec->precision < 0)
2023                        spec->precision = 0;
2024
2025                spec->type = FORMAT_TYPE_NONE;
2026                goto qualifier;
2027        }
2028
2029        /* By default */
2030        spec->type = FORMAT_TYPE_NONE;
2031
2032        for (; *fmt ; ++fmt) {
2033                if (*fmt == '%')
2034                        break;
2035        }
2036
2037        /* Return the current non-format string */
2038        if (fmt != start || !*fmt)
2039                return fmt - start;
2040
2041        /* Process flags */
2042        spec->flags = 0;
2043
2044        while (1) { /* this also skips first '%' */
2045                bool found = true;
2046
2047                ++fmt;
2048
2049                switch (*fmt) {
2050                case '-': spec->flags |= LEFT;    break;
2051                case '+': spec->flags |= PLUS;    break;
2052                case ' ': spec->flags |= SPACE;   break;
2053                case '#': spec->flags |= SPECIAL; break;
2054                case '0': spec->flags |= ZEROPAD; break;
2055                default:  found = false;
2056                }
2057
2058                if (!found)
2059                        break;
2060        }
2061
2062        /* get field width */
2063        spec->field_width = -1;
2064
2065        if (isdigit(*fmt))
2066                spec->field_width = skip_atoi(&fmt);
2067        else if (*fmt == '*') {
2068                /* it's the next argument */
2069                spec->type = FORMAT_TYPE_WIDTH;
2070                return ++fmt - start;
2071        }
2072
2073precision:
2074        /* get the precision */
2075        spec->precision = -1;
2076        if (*fmt == '.') {
2077                ++fmt;
2078                if (isdigit(*fmt)) {
2079                        spec->precision = skip_atoi(&fmt);
2080                        if (spec->precision < 0)
2081                                spec->precision = 0;
2082                } else if (*fmt == '*') {
2083                        /* it's the next argument */
2084                        spec->type = FORMAT_TYPE_PRECISION;
2085                        return ++fmt - start;
2086                }
2087        }
2088
2089qualifier:
2090        /* get the conversion qualifier */
2091        qualifier = 0;
2092        if (*fmt == 'h' || _tolower(*fmt) == 'l' ||
2093            *fmt == 'z' || *fmt == 't') {
2094                qualifier = *fmt++;
2095                if (unlikely(qualifier == *fmt)) {
2096                        if (qualifier == 'l') {
2097                                qualifier = 'L';
2098                                ++fmt;
2099                        } else if (qualifier == 'h') {
2100                                qualifier = 'H';
2101                                ++fmt;
2102                        }
2103                }
2104        }
2105
2106        /* default base */
2107        spec->base = 10;
2108        switch (*fmt) {
2109        case 'c':
2110                spec->type = FORMAT_TYPE_CHAR;
2111                return ++fmt - start;
2112
2113        case 's':
2114                spec->type = FORMAT_TYPE_STR;
2115                return ++fmt - start;
2116
2117        case 'p':
2118                spec->type = FORMAT_TYPE_PTR;
2119                return ++fmt - start;
2120
2121        case '%':
2122                spec->type = FORMAT_TYPE_PERCENT_CHAR;
2123                return ++fmt - start;
2124
2125        /* integer number formats - set up the flags and "break" */
2126        case 'o':
2127                spec->base = 8;
2128                break;
2129
2130        case 'x':
2131                spec->flags |= SMALL;
2132
2133        case 'X':
2134                spec->base = 16;
2135                break;
2136
2137        case 'd':
2138        case 'i':
2139                spec->flags |= SIGN;
2140        case 'u':
2141                break;
2142
2143        case 'n':
2144                /*
2145                 * Since %n poses a greater security risk than
2146                 * utility, treat it as any other invalid or
2147                 * unsupported format specifier.
2148                 */
2149                /* Fall-through */
2150
2151        default:
2152                WARN_ONCE(1, "Please remove unsupported %%%c in format string\n", *fmt);
2153                spec->type = FORMAT_TYPE_INVALID;
2154                return fmt - start;
2155        }
2156
2157        if (qualifier == 'L')
2158                spec->type = FORMAT_TYPE_LONG_LONG;
2159        else if (qualifier == 'l') {
2160                BUILD_BUG_ON(FORMAT_TYPE_ULONG + SIGN != FORMAT_TYPE_LONG);
2161                spec->type = FORMAT_TYPE_ULONG + (spec->flags & SIGN);
2162        } else if (qualifier == 'z') {
2163                spec->type = FORMAT_TYPE_SIZE_T;
2164        } else if (qualifier == 't') {
2165                spec->type = FORMAT_TYPE_PTRDIFF;
2166        } else if (qualifier == 'H') {
2167                BUILD_BUG_ON(FORMAT_TYPE_UBYTE + SIGN != FORMAT_TYPE_BYTE);
2168                spec->type = FORMAT_TYPE_UBYTE + (spec->flags & SIGN);
2169        } else if (qualifier == 'h') {
2170                BUILD_BUG_ON(FORMAT_TYPE_USHORT + SIGN != FORMAT_TYPE_SHORT);
2171                spec->type = FORMAT_TYPE_USHORT + (spec->flags & SIGN);
2172        } else {
2173                BUILD_BUG_ON(FORMAT_TYPE_UINT + SIGN != FORMAT_TYPE_INT);
2174                spec->type = FORMAT_TYPE_UINT + (spec->flags & SIGN);
2175        }
2176
2177        return ++fmt - start;
2178}
2179
2180static void
2181set_field_width(struct printf_spec *spec, int width)
2182{
2183        spec->field_width = width;
2184        if (WARN_ONCE(spec->field_width != width, "field width %d too large", width)) {
2185                spec->field_width = clamp(width, -FIELD_WIDTH_MAX, FIELD_WIDTH_MAX);
2186        }
2187}
2188
2189static void
2190set_precision(struct printf_spec *spec, int prec)
2191{
2192        spec->precision = prec;
2193        if (WARN_ONCE(spec->precision != prec, "precision %d too large", prec)) {
2194                spec->precision = clamp(prec, 0, PRECISION_MAX);
2195        }
2196}
2197
2198/**
2199 * vsnprintf - Format a string and place it in a buffer
2200 * @buf: The buffer to place the result into
2201 * @size: The size of the buffer, including the trailing null space
2202 * @fmt: The format string to use
2203 * @args: Arguments for the format string
2204 *
2205 * This function generally follows C99 vsnprintf, but has some
2206 * extensions and a few limitations:
2207 *
2208 *  - ``%n`` is unsupported
2209 *  - ``%p*`` is handled by pointer()
2210 *
2211 * See pointer() or Documentation/core-api/printk-formats.rst for more
2212 * extensive description.
2213 *
2214 * **Please update the documentation in both places when making changes**
2215 *
2216 * The return value is the number of characters which would
2217 * be generated for the given input, excluding the trailing
2218 * '\0', as per ISO C99. If you want to have the exact
2219 * number of characters written into @buf as return value
2220 * (not including the trailing '\0'), use vscnprintf(). If the
2221 * return is greater than or equal to @size, the resulting
2222 * string is truncated.
2223 *
2224 * If you're not already dealing with a va_list consider using snprintf().
2225 */
2226int vsnprintf(char *buf, size_t size, const char *fmt, va_list args)
2227{
2228        unsigned long long num;
2229        char *str, *end;
2230        struct printf_spec spec = {0};
2231
2232        /* Reject out-of-range values early.  Large positive sizes are
2233           used for unknown buffer sizes. */
2234        if (WARN_ON_ONCE(size > INT_MAX))
2235                return 0;
2236
2237        str = buf;
2238        end = buf + size;
2239
2240        /* Make sure end is always >= buf */
2241        if (end < buf) {
2242                end = ((void *)-1);
2243                size = end - buf;
2244        }
2245
2246        while (*fmt) {
2247                const char *old_fmt = fmt;
2248                int read = format_decode(fmt, &spec);
2249
2250                fmt += read;
2251
2252                switch (spec.type) {
2253                case FORMAT_TYPE_NONE: {
2254                        int copy = read;
2255                        if (str < end) {
2256                                if (copy > end - str)
2257                                        copy = end - str;
2258                                memcpy(str, old_fmt, copy);
2259                        }
2260                        str += read;
2261                        break;
2262                }
2263
2264                case FORMAT_TYPE_WIDTH:
2265                        set_field_width(&spec, va_arg(args, int));
2266                        break;
2267
2268                case FORMAT_TYPE_PRECISION:
2269                        set_precision(&spec, va_arg(args, int));
2270                        break;
2271
2272                case FORMAT_TYPE_CHAR: {
2273                        char c;
2274
2275                        if (!(spec.flags & LEFT)) {
2276                                while (--spec.field_width > 0) {
2277                                        if (str < end)
2278                                                *str = ' ';
2279                                        ++str;
2280
2281                                }
2282                        }
2283                        c = (unsigned char) va_arg(args, int);
2284                        if (str < end)
2285                                *str = c;
2286                        ++str;
2287                        while (--spec.field_width > 0) {
2288                                if (str < end)
2289                                        *str = ' ';
2290                                ++str;
2291                        }
2292                        break;
2293                }
2294
2295                case FORMAT_TYPE_STR:
2296                        str = string(str, end, va_arg(args, char *), spec);
2297                        break;
2298
2299                case FORMAT_TYPE_PTR:
2300                        str = pointer(fmt, str, end, va_arg(args, void *),
2301                                      spec);
2302                        while (isalnum(*fmt))
2303                                fmt++;
2304                        break;
2305
2306                case FORMAT_TYPE_PERCENT_CHAR:
2307                        if (str < end)
2308                                *str = '%';
2309                        ++str;
2310                        break;
2311
2312                case FORMAT_TYPE_INVALID:
2313                        /*
2314                         * Presumably the arguments passed gcc's type
2315                         * checking, but there is no safe or sane way
2316                         * for us to continue parsing the format and
2317                         * fetching from the va_list; the remaining
2318                         * specifiers and arguments would be out of
2319                         * sync.
2320                         */
2321                        goto out;
2322
2323                default:
2324                        switch (spec.type) {
2325                        case FORMAT_TYPE_LONG_LONG:
2326                                num = va_arg(args, long long);
2327                                break;
2328                        case FORMAT_TYPE_ULONG:
2329                                num = va_arg(args, unsigned long);
2330                                break;
2331                        case FORMAT_TYPE_LONG:
2332                                num = va_arg(args, long);
2333                                break;
2334                        case FORMAT_TYPE_SIZE_T:
2335                                if (spec.flags & SIGN)
2336                                        num = va_arg(args, ssize_t);
2337                                else
2338                                        num = va_arg(args, size_t);
2339                                break;
2340                        case FORMAT_TYPE_PTRDIFF:
2341                                num = va_arg(args, ptrdiff_t);
2342                                break;
2343                        case FORMAT_TYPE_UBYTE:
2344                                num = (unsigned char) va_arg(args, int);
2345                                break;
2346                        case FORMAT_TYPE_BYTE:
2347                                num = (signed char) va_arg(args, int);
2348                                break;
2349                        case FORMAT_TYPE_USHORT:
2350                                num = (unsigned short) va_arg(args, int);
2351                                break;
2352                        case FORMAT_TYPE_SHORT:
2353                                num = (short) va_arg(args, int);
2354                                break;
2355                        case FORMAT_TYPE_INT:
2356                                num = (int) va_arg(args, int);
2357                                break;
2358                        default:
2359                                num = va_arg(args, unsigned int);
2360                        }
2361
2362                        str = number(str, end, num, spec);
2363                }
2364        }
2365
2366out:
2367        if (size > 0) {
2368                if (str < end)
2369                        *str = '\0';
2370                else
2371                        end[-1] = '\0';
2372        }
2373
2374        /* the trailing null byte doesn't count towards the total */
2375        return str-buf;
2376
2377}
2378EXPORT_SYMBOL(vsnprintf);
2379
2380/**
2381 * vscnprintf - Format a string and place it in a buffer
2382 * @buf: The buffer to place the result into
2383 * @size: The size of the buffer, including the trailing null space
2384 * @fmt: The format string to use
2385 * @args: Arguments for the format string
2386 *
2387 * The return value is the number of characters which have been written into
2388 * the @buf not including the trailing '\0'. If @size is == 0 the function
2389 * returns 0.
2390 *
2391 * If you're not already dealing with a va_list consider using scnprintf().
2392 *
2393 * See the vsnprintf() documentation for format string extensions over C99.
2394 */
2395int vscnprintf(char *buf, size_t size, const char *fmt, va_list args)
2396{
2397        int i;
2398
2399        i = vsnprintf(buf, size, fmt, args);
2400
2401        if (likely(i < size))
2402                return i;
2403        if (size != 0)
2404                return size - 1;
2405        return 0;
2406}
2407EXPORT_SYMBOL(vscnprintf);
2408
2409/**
2410 * snprintf - Format a string and place it in a buffer
2411 * @buf: The buffer to place the result into
2412 * @size: The size of the buffer, including the trailing null space
2413 * @fmt: The format string to use
2414 * @...: Arguments for the format string
2415 *
2416 * The return value is the number of characters which would be
2417 * generated for the given input, excluding the trailing null,
2418 * as per ISO C99.  If the return is greater than or equal to
2419 * @size, the resulting string is truncated.
2420 *
2421 * See the vsnprintf() documentation for format string extensions over C99.
2422 */
2423int snprintf(char *buf, size_t size, const char *fmt, ...)
2424{
2425        va_list args;
2426        int i;
2427
2428        va_start(args, fmt);
2429        i = vsnprintf(buf, size, fmt, args);
2430        va_end(args);
2431
2432        return i;
2433}
2434EXPORT_SYMBOL(snprintf);
2435
2436/**
2437 * scnprintf - Format a string and place it in a buffer
2438 * @buf: The buffer to place the result into
2439 * @size: The size of the buffer, including the trailing null space
2440 * @fmt: The format string to use
2441 * @...: Arguments for the format string
2442 *
2443 * The return value is the number of characters written into @buf not including
2444 * the trailing '\0'. If @size is == 0 the function returns 0.
2445 */
2446
2447int scnprintf(char *buf, size_t size, const char *fmt, ...)
2448{
2449        va_list args;
2450        int i;
2451
2452        va_start(args, fmt);
2453        i = vscnprintf(buf, size, fmt, args);
2454        va_end(args);
2455
2456        return i;
2457}
2458EXPORT_SYMBOL(scnprintf);
2459
2460/**
2461 * vsprintf - Format a string and place it in a buffer
2462 * @buf: The buffer to place the result into
2463 * @fmt: The format string to use
2464 * @args: Arguments for the format string
2465 *
2466 * The function returns the number of characters written
2467 * into @buf. Use vsnprintf() or vscnprintf() in order to avoid
2468 * buffer overflows.
2469 *
2470 * If you're not already dealing with a va_list consider using sprintf().
2471 *
2472 * See the vsnprintf() documentation for format string extensions over C99.
2473 */
2474int vsprintf(char *buf, const char *fmt, va_list args)
2475{
2476        return vsnprintf(buf, INT_MAX, fmt, args);
2477}
2478EXPORT_SYMBOL(vsprintf);
2479
2480/**
2481 * sprintf - Format a string and place it in a buffer
2482 * @buf: The buffer to place the result into
2483 * @fmt: The format string to use
2484 * @...: Arguments for the format string
2485 *
2486 * The function returns the number of characters written
2487 * into @buf. Use snprintf() or scnprintf() in order to avoid
2488 * buffer overflows.
2489 *
2490 * See the vsnprintf() documentation for format string extensions over C99.
2491 */
2492int sprintf(char *buf, const char *fmt, ...)
2493{
2494        va_list args;
2495        int i;
2496
2497        va_start(args, fmt);
2498        i = vsnprintf(buf, INT_MAX, fmt, args);
2499        va_end(args);
2500
2501        return i;
2502}
2503EXPORT_SYMBOL(sprintf);
2504
2505#ifdef CONFIG_BINARY_PRINTF
2506/*
2507 * bprintf service:
2508 * vbin_printf() - VA arguments to binary data
2509 * bstr_printf() - Binary data to text string
2510 */
2511
2512/**
2513 * vbin_printf - Parse a format string and place args' binary value in a buffer
2514 * @bin_buf: The buffer to place args' binary value
2515 * @size: The size of the buffer(by words(32bits), not characters)
2516 * @fmt: The format string to use
2517 * @args: Arguments for the format string
2518 *
2519 * The format follows C99 vsnprintf, except %n is ignored, and its argument
2520 * is skipped.
2521 *
2522 * The return value is the number of words(32bits) which would be generated for
2523 * the given input.
2524 *
2525 * NOTE:
2526 * If the return value is greater than @size, the resulting bin_buf is NOT
2527 * valid for bstr_printf().
2528 */
2529int vbin_printf(u32 *bin_buf, size_t size, const char *fmt, va_list args)
2530{
2531        struct printf_spec spec = {0};
2532        char *str, *end;
2533        int width;
2534
2535        str = (char *)bin_buf;
2536        end = (char *)(bin_buf + size);
2537
2538#define save_arg(type)                                                  \
2539({                                                                      \
2540        unsigned long long value;                                       \
2541        if (sizeof(type) == 8) {                                        \
2542                unsigned long long val8;                                \
2543                str = PTR_ALIGN(str, sizeof(u32));                      \
2544                val8 = va_arg(args, unsigned long long);                \
2545                if (str + sizeof(type) <= end) {                        \
2546                        *(u32 *)str = *(u32 *)&val8;                    \
2547                        *(u32 *)(str + 4) = *((u32 *)&val8 + 1);        \
2548                }                                                       \
2549                value = val8;                                           \
2550        } else {                                                        \
2551                unsigned int val4;                                      \
2552                str = PTR_ALIGN(str, sizeof(type));                     \
2553                val4 = va_arg(args, int);                               \
2554                if (str + sizeof(type) <= end)                          \
2555                        *(typeof(type) *)str = (type)(long)val4;        \
2556                value = (unsigned long long)val4;                       \
2557        }                                                               \
2558        str += sizeof(type);                                            \
2559        value;                                                          \
2560})
2561
2562        while (*fmt) {
2563                int read = format_decode(fmt, &spec);
2564
2565                fmt += read;
2566
2567                switch (spec.type) {
2568                case FORMAT_TYPE_NONE:
2569                case FORMAT_TYPE_PERCENT_CHAR:
2570                        break;
2571                case FORMAT_TYPE_INVALID:
2572                        goto out;
2573
2574                case FORMAT_TYPE_WIDTH:
2575                case FORMAT_TYPE_PRECISION:
2576                        width = (int)save_arg(int);
2577                        /* Pointers may require the width */
2578                        if (*fmt == 'p')
2579                                set_field_width(&spec, width);
2580                        break;
2581
2582                case FORMAT_TYPE_CHAR:
2583                        save_arg(char);
2584                        break;
2585
2586                case FORMAT_TYPE_STR: {
2587                        const char *save_str = va_arg(args, char *);
2588                        size_t len;
2589
2590                        if ((unsigned long)save_str > (unsigned long)-PAGE_SIZE
2591                                        || (unsigned long)save_str < PAGE_SIZE)
2592                                save_str = "(null)";
2593                        len = strlen(save_str) + 1;
2594                        if (str + len < end)
2595                                memcpy(str, save_str, len);
2596                        str += len;
2597                        break;
2598                }
2599
2600                case FORMAT_TYPE_PTR:
2601                        /* Dereferenced pointers must be done now */
2602                        switch (*fmt) {
2603                        /* Dereference of functions is still OK */
2604                        case 'S':
2605                        case 's':
2606                        case 'F':
2607                        case 'f':
2608                        case 'x':
2609                        case 'K':
2610                                save_arg(void *);
2611                                break;
2612                        default:
2613                                if (!isalnum(*fmt)) {
2614                                        save_arg(void *);
2615                                        break;
2616                                }
2617                                str = pointer(fmt, str, end, va_arg(args, void *),
2618                                              spec);
2619                                if (str + 1 < end)
2620                                        *str++ = '\0';
2621                                else
2622                                        end[-1] = '\0'; /* Must be nul terminated */
2623                        }
2624                        /* skip all alphanumeric pointer suffixes */
2625                        while (isalnum(*fmt))
2626                                fmt++;
2627                        break;
2628
2629                default:
2630                        switch (spec.type) {
2631
2632                        case FORMAT_TYPE_LONG_LONG:
2633                                save_arg(long long);
2634                                break;
2635                        case FORMAT_TYPE_ULONG:
2636                        case FORMAT_TYPE_LONG:
2637                                save_arg(unsigned long);
2638                                break;
2639                        case FORMAT_TYPE_SIZE_T:
2640                                save_arg(size_t);
2641                                break;
2642                        case FORMAT_TYPE_PTRDIFF:
2643                                save_arg(ptrdiff_t);
2644                                break;
2645                        case FORMAT_TYPE_UBYTE:
2646                        case FORMAT_TYPE_BYTE:
2647                                save_arg(char);
2648                                break;
2649                        case FORMAT_TYPE_USHORT:
2650                        case FORMAT_TYPE_SHORT:
2651                                save_arg(short);
2652                                break;
2653                        default:
2654                                save_arg(int);
2655                        }
2656                }
2657        }
2658
2659out:
2660        return (u32 *)(PTR_ALIGN(str, sizeof(u32))) - bin_buf;
2661#undef save_arg
2662}
2663EXPORT_SYMBOL_GPL(vbin_printf);
2664
2665/**
2666 * bstr_printf - Format a string from binary arguments and place it in a buffer
2667 * @buf: The buffer to place the result into
2668 * @size: The size of the buffer, including the trailing null space
2669 * @fmt: The format string to use
2670 * @bin_buf: Binary arguments for the format string
2671 *
2672 * This function like C99 vsnprintf, but the difference is that vsnprintf gets
2673 * arguments from stack, and bstr_printf gets arguments from @bin_buf which is
2674 * a binary buffer that generated by vbin_printf.
2675 *
2676 * The format follows C99 vsnprintf, but has some extensions:
2677 *  see vsnprintf comment for details.
2678 *
2679 * The return value is the number of characters which would
2680 * be generated for the given input, excluding the trailing
2681 * '\0', as per ISO C99. If you want to have the exact
2682 * number of characters written into @buf as return value
2683 * (not including the trailing '\0'), use vscnprintf(). If the
2684 * return is greater than or equal to @size, the resulting
2685 * string is truncated.
2686 */
2687int bstr_printf(char *buf, size_t size, const char *fmt, const u32 *bin_buf)
2688{
2689        struct printf_spec spec = {0};
2690        char *str, *end;
2691        const char *args = (const char *)bin_buf;
2692
2693        if (WARN_ON_ONCE(size > INT_MAX))
2694                return 0;
2695
2696        str = buf;
2697        end = buf + size;
2698
2699#define get_arg(type)                                                   \
2700({                                                                      \
2701        typeof(type) value;                                             \
2702        if (sizeof(type) == 8) {                                        \
2703                args = PTR_ALIGN(args, sizeof(u32));                    \
2704                *(u32 *)&value = *(u32 *)args;                          \
2705                *((u32 *)&value + 1) = *(u32 *)(args + 4);              \
2706        } else {                                                        \
2707                args = PTR_ALIGN(args, sizeof(type));                   \
2708                value = *(typeof(type) *)args;                          \
2709        }                                                               \
2710        args += sizeof(type);                                           \
2711        value;                                                          \
2712})
2713
2714        /* Make sure end is always >= buf */
2715        if (end < buf) {
2716                end = ((void *)-1);
2717                size = end - buf;
2718        }
2719
2720        while (*fmt) {
2721                const char *old_fmt = fmt;
2722                int read = format_decode(fmt, &spec);
2723
2724                fmt += read;
2725
2726                switch (spec.type) {
2727                case FORMAT_TYPE_NONE: {
2728                        int copy = read;
2729                        if (str < end) {
2730                                if (copy > end - str)
2731                                        copy = end - str;
2732                                memcpy(str, old_fmt, copy);
2733                        }
2734                        str += read;
2735                        break;
2736                }
2737
2738                case FORMAT_TYPE_WIDTH:
2739                        set_field_width(&spec, get_arg(int));
2740                        break;
2741
2742                case FORMAT_TYPE_PRECISION:
2743                        set_precision(&spec, get_arg(int));
2744                        break;
2745
2746                case FORMAT_TYPE_CHAR: {
2747                        char c;
2748
2749                        if (!(spec.flags & LEFT)) {
2750                                while (--spec.field_width > 0) {
2751                                        if (str < end)
2752                                                *str = ' ';
2753                                        ++str;
2754                                }
2755                        }
2756                        c = (unsigned char) get_arg(char);
2757                        if (str < end)
2758                                *str = c;
2759                        ++str;
2760                        while (--spec.field_width > 0) {
2761                                if (str < end)
2762                                        *str = ' ';
2763                                ++str;
2764                        }
2765                        break;
2766                }
2767
2768                case FORMAT_TYPE_STR: {
2769                        const char *str_arg = args;
2770                        args += strlen(str_arg) + 1;
2771                        str = string(str, end, (char *)str_arg, spec);
2772                        break;
2773                }
2774
2775                case FORMAT_TYPE_PTR: {
2776                        bool process = false;
2777                        int copy, len;
2778                        /* Non function dereferences were already done */
2779                        switch (*fmt) {
2780                        case 'S':
2781                        case 's':
2782                        case 'F':
2783                        case 'f':
2784                        case 'x':
2785                        case 'K':
2786                                process = true;
2787                                break;
2788                        default:
2789                                if (!isalnum(*fmt)) {
2790                                        process = true;
2791                                        break;
2792                                }
2793                                /* Pointer dereference was already processed */
2794                                if (str < end) {
2795                                        len = copy = strlen(args);
2796                                        if (copy > end - str)
2797                                                copy = end - str;
2798                                        memcpy(str, args, copy);
2799                                        str += len;
2800                                        args += len;
2801                                }
2802                        }
2803                        if (process)
2804                                str = pointer(fmt, str, end, get_arg(void *), spec);
2805
2806                        while (isalnum(*fmt))
2807                                fmt++;
2808                        break;
2809                }
2810
2811                case FORMAT_TYPE_PERCENT_CHAR:
2812                        if (str < end)
2813                                *str = '%';
2814                        ++str;
2815                        break;
2816
2817                case FORMAT_TYPE_INVALID:
2818                        goto out;
2819
2820                default: {
2821                        unsigned long long num;
2822
2823                        switch (spec.type) {
2824
2825                        case FORMAT_TYPE_LONG_LONG:
2826                                num = get_arg(long long);
2827                                break;
2828                        case FORMAT_TYPE_ULONG:
2829                        case FORMAT_TYPE_LONG:
2830                                num = get_arg(unsigned long);
2831                                break;
2832                        case FORMAT_TYPE_SIZE_T:
2833                                num = get_arg(size_t);
2834                                break;
2835                        case FORMAT_TYPE_PTRDIFF:
2836                                num = get_arg(ptrdiff_t);
2837                                break;
2838                        case FORMAT_TYPE_UBYTE:
2839                                num = get_arg(unsigned char);
2840                                break;
2841                        case FORMAT_TYPE_BYTE:
2842                                num = get_arg(signed char);
2843                                break;
2844                        case FORMAT_TYPE_USHORT:
2845                                num = get_arg(unsigned short);
2846                                break;
2847                        case FORMAT_TYPE_SHORT:
2848                                num = get_arg(short);
2849                                break;
2850                        case FORMAT_TYPE_UINT:
2851                                num = get_arg(unsigned int);
2852                                break;
2853                        default:
2854                                num = get_arg(int);
2855                        }
2856
2857                        str = number(str, end, num, spec);
2858                } /* default: */
2859                } /* switch(spec.type) */
2860        } /* while(*fmt) */
2861
2862out:
2863        if (size > 0) {
2864                if (str < end)
2865                        *str = '\0';
2866                else
2867                        end[-1] = '\0';
2868        }
2869
2870#undef get_arg
2871
2872        /* the trailing null byte doesn't count towards the total */
2873        return str - buf;
2874}
2875EXPORT_SYMBOL_GPL(bstr_printf);
2876
2877/**
2878 * bprintf - Parse a format string and place args' binary value in a buffer
2879 * @bin_buf: The buffer to place args' binary value
2880 * @size: The size of the buffer(by words(32bits), not characters)
2881 * @fmt: The format string to use
2882 * @...: Arguments for the format string
2883 *
2884 * The function returns the number of words(u32) written
2885 * into @bin_buf.
2886 */
2887int bprintf(u32 *bin_buf, size_t size, const char *fmt, ...)
2888{
2889        va_list args;
2890        int ret;
2891
2892        va_start(args, fmt);
2893        ret = vbin_printf(bin_buf, size, fmt, args);
2894        va_end(args);
2895
2896        return ret;
2897}
2898EXPORT_SYMBOL_GPL(bprintf);
2899
2900#endif /* CONFIG_BINARY_PRINTF */
2901
2902/**
2903 * vsscanf - Unformat a buffer into a list of arguments
2904 * @buf:        input buffer
2905 * @fmt:        format of buffer
2906 * @args:       arguments
2907 */
2908int vsscanf(const char *buf, const char *fmt, va_list args)
2909{
2910        const char *str = buf;
2911        char *next;
2912        char digit;
2913        int num = 0;
2914        u8 qualifier;
2915        unsigned int base;
2916        union {
2917                long long s;
2918                unsigned long long u;
2919        } val;
2920        s16 field_width;
2921        bool is_sign;
2922
2923        while (*fmt) {
2924                /* skip any white space in format */
2925                /* white space in format matchs any amount of
2926                 * white space, including none, in the input.
2927                 */
2928                if (isspace(*fmt)) {
2929                        fmt = skip_spaces(++fmt);
2930                        str = skip_spaces(str);
2931                }
2932
2933                /* anything that is not a conversion must match exactly */
2934                if (*fmt != '%' && *fmt) {
2935                        if (*fmt++ != *str++)
2936                                break;
2937                        continue;
2938                }
2939
2940                if (!*fmt)
2941                        break;
2942                ++fmt;
2943
2944                /* skip this conversion.
2945                 * advance both strings to next white space
2946                 */
2947                if (*fmt == '*') {
2948                        if (!*str)
2949                                break;
2950                        while (!isspace(*fmt) && *fmt != '%' && *fmt) {
2951                                /* '%*[' not yet supported, invalid format */
2952                                if (*fmt == '[')
2953                                        return num;
2954                                fmt++;
2955                        }
2956                        while (!isspace(*str) && *str)
2957                                str++;
2958                        continue;
2959                }
2960
2961                /* get field width */
2962                field_width = -1;
2963                if (isdigit(*fmt)) {
2964                        field_width = skip_atoi(&fmt);
2965                        if (field_width <= 0)
2966                                break;
2967                }
2968
2969                /* get conversion qualifier */
2970                qualifier = -1;
2971                if (*fmt == 'h' || _tolower(*fmt) == 'l' ||
2972                    *fmt == 'z') {
2973                        qualifier = *fmt++;
2974                        if (unlikely(qualifier == *fmt)) {
2975                                if (qualifier == 'h') {
2976                                        qualifier = 'H';
2977                                        fmt++;
2978                                } else if (qualifier == 'l') {
2979                                        qualifier = 'L';
2980                                        fmt++;
2981                                }
2982                        }
2983                }
2984
2985                if (!*fmt)
2986                        break;
2987
2988                if (*fmt == 'n') {
2989                        /* return number of characters read so far */
2990                        *va_arg(args, int *) = str - buf;
2991                        ++fmt;
2992                        continue;
2993                }
2994
2995                if (!*str)
2996                        break;
2997
2998                base = 10;
2999                is_sign = false;
3000
3001                switch (*fmt++) {
3002                case 'c':
3003                {
3004                        char *s = (char *)va_arg(args, char*);
3005                        if (field_width == -1)
3006                                field_width = 1;
3007                        do {
3008                                *s++ = *str++;
3009                        } while (--field_width > 0 && *str);
3010                        num++;
3011                }
3012                continue;
3013                case 's':
3014                {
3015                        char *s = (char *)va_arg(args, char *);
3016                        if (field_width == -1)
3017                                field_width = SHRT_MAX;
3018                        /* first, skip leading white space in buffer */
3019                        str = skip_spaces(str);
3020
3021                        /* now copy until next white space */
3022                        while (*str && !isspace(*str) && field_width--)
3023                                *s++ = *str++;
3024                        *s = '\0';
3025                        num++;
3026                }
3027                continue;
3028                /*
3029                 * Warning: This implementation of the '[' conversion specifier
3030                 * deviates from its glibc counterpart in the following ways:
3031                 * (1) It does NOT support ranges i.e. '-' is NOT a special
3032                 *     character
3033                 * (2) It cannot match the closing bracket ']' itself
3034                 * (3) A field width is required
3035                 * (4) '%*[' (discard matching input) is currently not supported
3036                 *
3037                 * Example usage:
3038                 * ret = sscanf("00:0a:95","%2[^:]:%2[^:]:%2[^:]",
3039                 *              buf1, buf2, buf3);
3040                 * if (ret < 3)
3041                 *    // etc..
3042                 */
3043                case '[':
3044                {
3045                        char *s = (char *)va_arg(args, char *);
3046                        DECLARE_BITMAP(set, 256) = {0};
3047                        unsigned int len = 0;
3048                        bool negate = (*fmt == '^');
3049
3050                        /* field width is required */
3051                        if (field_width == -1)
3052                                return num;
3053
3054                        if (negate)
3055                                ++fmt;
3056
3057                        for ( ; *fmt && *fmt != ']'; ++fmt, ++len)
3058                                set_bit((u8)*fmt, set);
3059
3060                        /* no ']' or no character set found */
3061                        if (!*fmt || !len)
3062                                return num;
3063                        ++fmt;
3064
3065                        if (negate) {
3066                                bitmap_complement(set, set, 256);
3067                                /* exclude null '\0' byte */
3068                                clear_bit(0, set);
3069                        }
3070
3071                        /* match must be non-empty */
3072                        if (!test_bit((u8)*str, set))
3073                                return num;
3074
3075                        while (test_bit((u8)*str, set) && field_width--)
3076                                *s++ = *str++;
3077                        *s = '\0';
3078                        ++num;
3079                }
3080                continue;
3081                case 'o':
3082                        base = 8;
3083                        break;
3084                case 'x':
3085                case 'X':
3086                        base = 16;
3087                        break;
3088                case 'i':
3089                        base = 0;
3090                case 'd':
3091                        is_sign = true;
3092                case 'u':
3093                        break;
3094                case '%':
3095                        /* looking for '%' in str */
3096                        if (*str++ != '%')
3097                                return num;
3098                        continue;
3099                default:
3100                        /* invalid format; stop here */
3101                        return num;
3102                }
3103
3104                /* have some sort of integer conversion.
3105                 * first, skip white space in buffer.
3106                 */
3107                str = skip_spaces(str);
3108
3109                digit = *str;
3110                if (is_sign && digit == '-')
3111                        digit = *(str + 1);
3112
3113                if (!digit
3114                    || (base == 16 && !isxdigit(digit))
3115                    || (base == 10 && !isdigit(digit))
3116                    || (base == 8 && (!isdigit(digit) || digit > '7'))
3117                    || (base == 0 && !isdigit(digit)))
3118                        break;
3119
3120                if (is_sign)
3121                        val.s = qualifier != 'L' ?
3122                                simple_strtol(str, &next, base) :
3123                                simple_strtoll(str, &next, base);
3124                else
3125                        val.u = qualifier != 'L' ?
3126                                simple_strtoul(str, &next, base) :
3127                                simple_strtoull(str, &next, base);
3128
3129                if (field_width > 0 && next - str > field_width) {
3130                        if (base == 0)
3131                                _parse_integer_fixup_radix(str, &base);
3132                        while (next - str > field_width) {
3133                                if (is_sign)
3134                                        val.s = div_s64(val.s, base);
3135                                else
3136                                        val.u = div_u64(val.u, base);
3137                                --next;
3138                        }
3139                }
3140
3141                switch (qualifier) {
3142                case 'H':       /* that's 'hh' in format */
3143                        if (is_sign)
3144                                *va_arg(args, signed char *) = val.s;
3145                        else
3146                                *va_arg(args, unsigned char *) = val.u;
3147                        break;
3148                case 'h':
3149                        if (is_sign)
3150                                *va_arg(args, short *) = val.s;
3151                        else
3152                                *va_arg(args, unsigned short *) = val.u;
3153                        break;
3154                case 'l':
3155                        if (is_sign)
3156                                *va_arg(args, long *) = val.s;
3157                        else
3158                                *va_arg(args, unsigned long *) = val.u;
3159                        break;
3160                case 'L':
3161                        if (is_sign)
3162                                *va_arg(args, long long *) = val.s;
3163                        else
3164                                *va_arg(args, unsigned long long *) = val.u;
3165                        break;
3166                case 'z':
3167                        *va_arg(args, size_t *) = val.u;
3168                        break;
3169                default:
3170                        if (is_sign)
3171                                *va_arg(args, int *) = val.s;
3172                        else
3173                                *va_arg(args, unsigned int *) = val.u;
3174                        break;
3175                }
3176                num++;
3177
3178                if (!next)
3179                        break;
3180                str = next;
3181        }
3182
3183        return num;
3184}
3185EXPORT_SYMBOL(vsscanf);
3186
3187/**
3188 * sscanf - Unformat a buffer into a list of arguments
3189 * @buf:        input buffer
3190 * @fmt:        formatting of buffer
3191 * @...:        resulting arguments
3192 */
3193int sscanf(const char *buf, const char *fmt, ...)
3194{
3195        va_list args;
3196        int i;
3197
3198        va_start(args, fmt);
3199        i = vsscanf(buf, fmt, args);
3200        va_end(args);
3201
3202        return i;
3203}
3204EXPORT_SYMBOL(sscanf);
3205