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  54 * This function is obsolete.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  79 * This function is obsolete.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  93 * This function is obsolete.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