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/module.h>       /* for KSYM_SYMBOL_LEN */
  21#include <linux/types.h>
  22#include <linux/string.h>
  23#include <linux/ctype.h>
  24#include <linux/kernel.h>
  25#include <linux/kallsyms.h>
  26#include <linux/math64.h>
  27#include <linux/uaccess.h>
  28#include <linux/ioport.h>
  29#include <net/addrconf.h>
  30
  31#include <asm/page.h>           /* for PAGE_SIZE */
  32#include <asm/sections.h>       /* for dereference_function_descriptor() */
  33
  34#include "kstrtox.h"
  35
  36/**
  37 * simple_strtoull - convert a string to an unsigned long long
  38 * @cp: The start of the string
  39 * @endp: A pointer to the end of the parsed string will be placed here
  40 * @base: The number base to use
  41 *
  42 * This function is obsolete. Please use kstrtoull instead.
  43 */
  44unsigned long long simple_strtoull(const char *cp, char **endp, unsigned int base)
  45{
  46        unsigned long long result;
  47        unsigned int rv;
  48
  49        cp = _parse_integer_fixup_radix(cp, &base);
  50        rv = _parse_integer(cp, base, &result);
  51        /* FIXME */
  52        cp += (rv & ~KSTRTOX_OVERFLOW);
  53
  54        if (endp)
  55                *endp = (char *)cp;
  56
  57        return result;
  58}
  59EXPORT_SYMBOL(simple_strtoull);
  60
  61/**
  62 * simple_strtoul - convert a string to an unsigned long
  63 * @cp: The start of the string
  64 * @endp: A pointer to the end of the parsed string will be placed here
  65 * @base: The number base to use
  66 *
  67 * This function is obsolete. Please use kstrtoul instead.
  68 */
  69unsigned long simple_strtoul(const char *cp, char **endp, unsigned int base)
  70{
  71        return simple_strtoull(cp, endp, base);
  72}
  73EXPORT_SYMBOL(simple_strtoul);
  74
  75/**
  76 * simple_strtol - convert a string to a signed long
  77 * @cp: The start of the string
  78 * @endp: A pointer to the end of the parsed string will be placed here
  79 * @base: The number base to use
  80 *
  81 * This function is obsolete. Please use kstrtol instead.
  82 */
  83long simple_strtol(const char *cp, char **endp, unsigned int base)
  84{
  85        if (*cp == '-')
  86                return -simple_strtoul(cp + 1, endp, base);
  87
  88        return simple_strtoul(cp, endp, base);
  89}
  90EXPORT_SYMBOL(simple_strtol);
  91
  92/**
  93 * simple_strtoll - convert a string to a signed long long
  94 * @cp: The start of the string
  95 * @endp: A pointer to the end of the parsed string will be placed here
  96 * @base: The number base to use
  97 *
  98 * This function is obsolete. Please use kstrtoll instead.
  99 */
 100long long simple_strtoll(const char *cp, char **endp, unsigned int base)
 101{
 102        if (*cp == '-')
 103                return -simple_strtoull(cp + 1, endp, base);
 104
 105        return simple_strtoull(cp, endp, base);
 106}
 107EXPORT_SYMBOL(simple_strtoll);
 108
 109static noinline_for_stack
 110int skip_atoi(const char **s)
 111{
 112        int i = 0;
 113
 114        while (isdigit(**s))
 115                i = i*10 + *((*s)++) - '0';
 116
 117        return i;
 118}
 119
 120/* Decimal conversion is by far the most typical, and is used
 121 * for /proc and /sys data. This directly impacts e.g. top performance
 122 * with many processes running. We optimize it for speed
 123 * using ideas described at <http://www.cs.uiowa.edu/~jones/bcd/divide.html>
 124 * (with permission from the author, Douglas W. Jones).
 125 */
 126
 127#if BITS_PER_LONG != 32 || BITS_PER_LONG_LONG != 64
 128/* Formats correctly any integer in [0, 999999999] */
 129static noinline_for_stack
 130char *put_dec_full9(char *buf, unsigned q)
 131{
 132        unsigned r;
 133
 134        /*
 135         * Possible ways to approx. divide by 10
 136         * (x * 0x1999999a) >> 32 x < 1073741829 (multiply must be 64-bit)
 137         * (x * 0xcccd) >> 19     x <      81920 (x < 262149 when 64-bit mul)
 138         * (x * 0x6667) >> 18     x <      43699
 139         * (x * 0x3334) >> 17     x <      16389
 140         * (x * 0x199a) >> 16     x <      16389
 141         * (x * 0x0ccd) >> 15     x <      16389
 142         * (x * 0x0667) >> 14     x <       2739
 143         * (x * 0x0334) >> 13     x <       1029
 144         * (x * 0x019a) >> 12     x <       1029
 145         * (x * 0x00cd) >> 11     x <       1029 shorter code than * 0x67 (on i386)
 146         * (x * 0x0067) >> 10     x <        179
 147         * (x * 0x0034) >>  9     x <         69 same
 148         * (x * 0x001a) >>  8     x <         69 same
 149         * (x * 0x000d) >>  7     x <         69 same, shortest code (on i386)
 150         * (x * 0x0007) >>  6     x <         19
 151         * See <http://www.cs.uiowa.edu/~jones/bcd/divide.html>
 152         */
 153        r      = (q * (uint64_t)0x1999999a) >> 32;
 154        *buf++ = (q - 10 * r) + '0'; /* 1 */
 155        q      = (r * (uint64_t)0x1999999a) >> 32;
 156        *buf++ = (r - 10 * q) + '0'; /* 2 */
 157        r      = (q * (uint64_t)0x1999999a) >> 32;
 158        *buf++ = (q - 10 * r) + '0'; /* 3 */
 159        q      = (r * (uint64_t)0x1999999a) >> 32;
 160        *buf++ = (r - 10 * q) + '0'; /* 4 */
 161        r      = (q * (uint64_t)0x1999999a) >> 32;
 162        *buf++ = (q - 10 * r) + '0'; /* 5 */
 163        /* Now value is under 10000, can avoid 64-bit multiply */
 164        q      = (r * 0x199a) >> 16;
 165        *buf++ = (r - 10 * q)  + '0'; /* 6 */
 166        r      = (q * 0xcd) >> 11;
 167        *buf++ = (q - 10 * r)  + '0'; /* 7 */
 168        q      = (r * 0xcd) >> 11;
 169        *buf++ = (r - 10 * q) + '0'; /* 8 */
 170        *buf++ = q + '0'; /* 9 */
 171        return buf;
 172}
 173#endif
 174
 175/* Similar to above but do not pad with zeros.
 176 * Code can be easily arranged to print 9 digits too, but our callers
 177 * always call put_dec_full9() instead when the number has 9 decimal digits.
 178 */
 179static noinline_for_stack
 180char *put_dec_trunc8(char *buf, unsigned r)
 181{
 182        unsigned q;
 183
 184        /* Copy of previous function's body with added early returns */
 185        while (r >= 10000) {
 186                q = r + '0';
 187                r  = (r * (uint64_t)0x1999999a) >> 32;
 188                *buf++ = q - 10*r;
 189        }
 190
 191        q      = (r * 0x199a) >> 16;    /* r <= 9999 */
 192        *buf++ = (r - 10 * q)  + '0';
 193        if (q == 0)
 194                return buf;
 195        r      = (q * 0xcd) >> 11;      /* q <= 999 */
 196        *buf++ = (q - 10 * r)  + '0';
 197        if (r == 0)
 198                return buf;
 199        q      = (r * 0xcd) >> 11;      /* r <= 99 */
 200        *buf++ = (r - 10 * q) + '0';
 201        if (q == 0)
 202                return buf;
 203        *buf++ = q + '0';                /* q <= 9 */
 204        return buf;
 205}
 206
 207/* There are two algorithms to print larger numbers.
 208 * One is generic: divide by 1000000000 and repeatedly print
 209 * groups of (up to) 9 digits. It's conceptually simple,
 210 * but requires a (unsigned long long) / 1000000000 division.
 211 *
 212 * Second algorithm splits 64-bit unsigned long long into 16-bit chunks,
 213 * manipulates them cleverly and generates groups of 4 decimal digits.
 214 * It so happens that it does NOT require long long division.
 215 *
 216 * If long is > 32 bits, division of 64-bit values is relatively easy,
 217 * and we will use the first algorithm.
 218 * If long long is > 64 bits (strange architecture with VERY large long long),
 219 * second algorithm can't be used, and we again use the first one.
 220 *
 221 * Else (if long is 32 bits and long long is 64 bits) we use second one.
 222 */
 223
 224#if BITS_PER_LONG != 32 || BITS_PER_LONG_LONG != 64
 225
 226/* First algorithm: generic */
 227
 228static
 229char *put_dec(char *buf, unsigned long long n)
 230{
 231        if (n >= 100*1000*1000) {
 232                while (n >= 1000*1000*1000)
 233                        buf = put_dec_full9(buf, do_div(n, 1000*1000*1000));
 234                if (n >= 100*1000*1000)
 235                        return put_dec_full9(buf, n);
 236        }
 237        return put_dec_trunc8(buf, n);
 238}
 239
 240#else
 241
 242/* Second algorithm: valid only for 64-bit long longs */
 243
 244/* See comment in put_dec_full9 for choice of constants */
 245static noinline_for_stack
 246void put_dec_full4(char *buf, unsigned q)
 247{
 248        unsigned r;
 249        r      = (q * 0xccd) >> 15;
 250        buf[0] = (q - 10 * r) + '0';
 251        q      = (r * 0xcd) >> 11;
 252        buf[1] = (r - 10 * q)  + '0';
 253        r      = (q * 0xcd) >> 11;
 254        buf[2] = (q - 10 * r)  + '0';
 255        buf[3] = r + '0';
 256}
 257
 258/*
 259 * Call put_dec_full4 on x % 10000, return x / 10000.
 260 * The approximation x/10000 == (x * 0x346DC5D7) >> 43
 261 * holds for all x < 1,128,869,999.  The largest value this
 262 * helper will ever be asked to convert is 1,125,520,955.
 263 * (d1 in the put_dec code, assuming n is all-ones).
 264 */
 265static
 266unsigned put_dec_helper4(char *buf, unsigned x)
 267{
 268        uint32_t q = (x * (uint64_t)0x346DC5D7) >> 43;
 269
 270        put_dec_full4(buf, x - q * 10000);
 271        return q;
 272}
 273
 274/* Based on code by Douglas W. Jones found at
 275 * <http://www.cs.uiowa.edu/~jones/bcd/decimal.html#sixtyfour>
 276 * (with permission from the author).
 277 * Performs no 64-bit division and hence should be fast on 32-bit machines.
 278 */
 279static
 280char *put_dec(char *buf, unsigned long long n)
 281{
 282        uint32_t d3, d2, d1, q, h;
 283
 284        if (n < 100*1000*1000)
 285                return put_dec_trunc8(buf, n);
 286
 287        d1  = ((uint32_t)n >> 16); /* implicit "& 0xffff" */
 288        h   = (n >> 32);
 289        d2  = (h      ) & 0xffff;
 290        d3  = (h >> 16); /* implicit "& 0xffff" */
 291
 292        q   = 656 * d3 + 7296 * d2 + 5536 * d1 + ((uint32_t)n & 0xffff);
 293        q = put_dec_helper4(buf, q);
 294
 295        q += 7671 * d3 + 9496 * d2 + 6 * d1;
 296        q = put_dec_helper4(buf+4, q);
 297
 298        q += 4749 * d3 + 42 * d2;
 299        q = put_dec_helper4(buf+8, q);
 300
 301        q += 281 * d3;
 302        buf += 12;
 303        if (q)
 304                buf = put_dec_trunc8(buf, q);
 305        else while (buf[-1] == '0')
 306                --buf;
 307
 308        return buf;
 309}
 310
 311#endif
 312
 313/*
 314 * Convert passed number to decimal string.
 315 * Returns the length of string.  On buffer overflow, returns 0.
 316 *
 317 * If speed is not important, use snprintf(). It's easy to read the code.
 318 */
 319int num_to_str(char *buf, int size, unsigned long long num)
 320{
 321        char tmp[sizeof(num) * 3];
 322        int idx, len;
 323
 324        /* put_dec() may work incorrectly for num = 0 (generate "", not "0") */
 325        if (num <= 9) {
 326                tmp[0] = '0' + num;
 327                len = 1;
 328        } else {
 329                len = put_dec(tmp, num) - tmp;
 330        }
 331
 332        if (len > size)
 333                return 0;
 334        for (idx = 0; idx < len; ++idx)
 335                buf[idx] = tmp[len - idx - 1];
 336        return len;
 337}
 338
 339#define ZEROPAD 1               /* pad with zero */
 340#define SIGN    2               /* unsigned/signed long */
 341#define PLUS    4               /* show plus */
 342#define SPACE   8               /* space if plus */
 343#define LEFT    16              /* left justified */
 344#define SMALL   32              /* use lowercase in hex (must be 32 == 0x20) */
 345#define SPECIAL 64              /* prefix hex with "0x", octal with "0" */
 346
 347enum format_type {
 348        FORMAT_TYPE_NONE, /* Just a string part */
 349        FORMAT_TYPE_WIDTH,
 350        FORMAT_TYPE_PRECISION,
 351        FORMAT_TYPE_CHAR,
 352        FORMAT_TYPE_STR,
 353        FORMAT_TYPE_PTR,
 354        FORMAT_TYPE_PERCENT_CHAR,
 355        FORMAT_TYPE_INVALID,
 356        FORMAT_TYPE_LONG_LONG,
 357        FORMAT_TYPE_ULONG,
 358        FORMAT_TYPE_LONG,
 359        FORMAT_TYPE_UBYTE,
 360        FORMAT_TYPE_BYTE,
 361        FORMAT_TYPE_USHORT,
 362        FORMAT_TYPE_SHORT,
 363        FORMAT_TYPE_UINT,
 364        FORMAT_TYPE_INT,
 365        FORMAT_TYPE_NRCHARS,
 366        FORMAT_TYPE_SIZE_T,
 367        FORMAT_TYPE_PTRDIFF
 368};
 369
 370struct printf_spec {
 371        u8      type;           /* format_type enum */
 372        u8      flags;          /* flags to number() */
 373        u8      base;           /* number base, 8, 10 or 16 only */
 374        u8      qualifier;      /* number qualifier, one of 'hHlLtzZ' */
 375        s16     field_width;    /* width of output field */
 376        s16     precision;      /* # of digits/chars */
 377};
 378
 379static noinline_for_stack
 380char *number(char *buf, char *end, unsigned long long num,
 381             struct printf_spec spec)
 382{
 383        /* we are called with base 8, 10 or 16, only, thus don't need "G..."  */
 384        static const char digits[16] = "0123456789ABCDEF"; /* "GHIJKLMNOPQRSTUVWXYZ"; */
 385
 386        char tmp[66];
 387        char sign;
 388        char locase;
 389        int need_pfx = ((spec.flags & SPECIAL) && spec.base != 10);
 390        int i;
 391        bool is_zero = num == 0LL;
 392
 393        /* locase = 0 or 0x20. ORing digits or letters with 'locase'
 394         * produces same digits or (maybe lowercased) letters */
 395        locase = (spec.flags & SMALL);
 396        if (spec.flags & LEFT)
 397                spec.flags &= ~ZEROPAD;
 398        sign = 0;
 399        if (spec.flags & SIGN) {
 400                if ((signed long long)num < 0) {
 401                        sign = '-';
 402                        num = -(signed long long)num;
 403                        spec.field_width--;
 404                } else if (spec.flags & PLUS) {
 405                        sign = '+';
 406                        spec.field_width--;
 407                } else if (spec.flags & SPACE) {
 408                        sign = ' ';
 409                        spec.field_width--;
 410                }
 411        }
 412        if (need_pfx) {
 413                if (spec.base == 16)
 414                        spec.field_width -= 2;
 415                else if (!is_zero)
 416                        spec.field_width--;
 417        }
 418
 419        /* generate full string in tmp[], in reverse order */
 420        i = 0;
 421        if (num < spec.base)
 422                tmp[i++] = digits[num] | locase;
 423        /* Generic code, for any base:
 424        else do {
 425                tmp[i++] = (digits[do_div(num,base)] | locase);
 426        } while (num != 0);
 427        */
 428        else if (spec.base != 10) { /* 8 or 16 */
 429                int mask = spec.base - 1;
 430                int shift = 3;
 431
 432                if (spec.base == 16)
 433                        shift = 4;
 434                do {
 435                        tmp[i++] = (digits[((unsigned char)num) & mask] | locase);
 436                        num >>= shift;
 437                } while (num);
 438        } else { /* base 10 */
 439                i = put_dec(tmp, num) - tmp;
 440        }
 441
 442        /* printing 100 using %2d gives "100", not "00" */
 443        if (i > spec.precision)
 444                spec.precision = i;
 445        /* leading space padding */
 446        spec.field_width -= spec.precision;
 447        if (!(spec.flags & (ZEROPAD+LEFT))) {
 448                while (--spec.field_width >= 0) {
 449                        if (buf < end)
 450                                *buf = ' ';
 451                        ++buf;
 452                }
 453        }
 454        /* sign */
 455        if (sign) {
 456                if (buf < end)
 457                        *buf = sign;
 458                ++buf;
 459        }
 460        /* "0x" / "0" prefix */
 461        if (need_pfx) {
 462                if (spec.base == 16 || !is_zero) {
 463                        if (buf < end)
 464                                *buf = '0';
 465                        ++buf;
 466                }
 467                if (spec.base == 16) {
 468                        if (buf < end)
 469                                *buf = ('X' | locase);
 470                        ++buf;
 471                }
 472        }
 473        /* zero or space padding */
 474        if (!(spec.flags & LEFT)) {
 475                char c = (spec.flags & ZEROPAD) ? '0' : ' ';
 476                while (--spec.field_width >= 0) {
 477                        if (buf < end)
 478                                *buf = c;
 479                        ++buf;
 480                }
 481        }
 482        /* hmm even more zero padding? */
 483        while (i <= --spec.precision) {
 484                if (buf < end)
 485                        *buf = '0';
 486                ++buf;
 487        }
 488        /* actual digits of result */
 489        while (--i >= 0) {
 490                if (buf < end)
 491                        *buf = tmp[i];
 492                ++buf;
 493        }
 494        /* trailing space padding */
 495        while (--spec.field_width >= 0) {
 496                if (buf < end)
 497                        *buf = ' ';
 498                ++buf;
 499        }
 500
 501        return buf;
 502}
 503
 504static noinline_for_stack
 505char *string(char *buf, char *end, const char *s, struct printf_spec spec)
 506{
 507        int len, i;
 508
 509        if ((unsigned long)s < PAGE_SIZE)
 510                s = "(null)";
 511
 512        len = strnlen(s, spec.precision);
 513
 514        if (!(spec.flags & LEFT)) {
 515                while (len < spec.field_width--) {
 516                        if (buf < end)
 517                                *buf = ' ';
 518                        ++buf;
 519                }
 520        }
 521        for (i = 0; i < len; ++i) {
 522                if (buf < end)
 523                        *buf = *s;
 524                ++buf; ++s;
 525        }
 526        while (len < spec.field_width--) {
 527                if (buf < end)
 528                        *buf = ' ';
 529                ++buf;
 530        }
 531
 532        return buf;
 533}
 534
 535static noinline_for_stack
 536char *symbol_string(char *buf, char *end, void *ptr,
 537                    struct printf_spec spec, char ext)
 538{
 539        unsigned long value = (unsigned long) ptr;
 540#ifdef CONFIG_KALLSYMS
 541        char sym[KSYM_SYMBOL_LEN];
 542        if (ext == 'B')
 543                sprint_backtrace(sym, value);
 544        else if (ext != 'f' && ext != 's')
 545                sprint_symbol(sym, value);
 546        else
 547                sprint_symbol_no_offset(sym, value);
 548
 549        return string(buf, end, sym, spec);
 550#else
 551        spec.field_width = 2 * sizeof(void *);
 552        spec.flags |= SPECIAL | SMALL | ZEROPAD;
 553        spec.base = 16;
 554
 555        return number(buf, end, value, spec);
 556#endif
 557}
 558
 559static noinline_for_stack
 560char *resource_string(char *buf, char *end, struct resource *res,
 561                      struct printf_spec spec, const char *fmt)
 562{
 563#ifndef IO_RSRC_PRINTK_SIZE
 564#define IO_RSRC_PRINTK_SIZE     6
 565#endif
 566
 567#ifndef MEM_RSRC_PRINTK_SIZE
 568#define MEM_RSRC_PRINTK_SIZE    10
 569#endif
 570        static const struct printf_spec io_spec = {
 571                .base = 16,
 572                .field_width = IO_RSRC_PRINTK_SIZE,
 573                .precision = -1,
 574                .flags = SPECIAL | SMALL | ZEROPAD,
 575        };
 576        static const struct printf_spec mem_spec = {
 577                .base = 16,
 578                .field_width = MEM_RSRC_PRINTK_SIZE,
 579                .precision = -1,
 580                .flags = SPECIAL | SMALL | ZEROPAD,
 581        };
 582        static const struct printf_spec bus_spec = {
 583                .base = 16,
 584                .field_width = 2,
 585                .precision = -1,
 586                .flags = SMALL | ZEROPAD,
 587        };
 588        static const struct printf_spec dec_spec = {
 589                .base = 10,
 590                .precision = -1,
 591                .flags = 0,
 592        };
 593        static const struct printf_spec str_spec = {
 594                .field_width = -1,
 595                .precision = 10,
 596                .flags = LEFT,
 597        };
 598        static const struct printf_spec flag_spec = {
 599                .base = 16,
 600                .precision = -1,
 601                .flags = SPECIAL | SMALL,
 602        };
 603
 604        /* 32-bit res (sizeof==4): 10 chars in dec, 10 in hex ("0x" + 8)
 605         * 64-bit res (sizeof==8): 20 chars in dec, 18 in hex ("0x" + 16) */
 606#define RSRC_BUF_SIZE           ((2 * sizeof(resource_size_t)) + 4)
 607#define FLAG_BUF_SIZE           (2 * sizeof(res->flags))
 608#define DECODED_BUF_SIZE        sizeof("[mem - 64bit pref window disabled]")
 609#define RAW_BUF_SIZE            sizeof("[mem - flags 0x]")
 610        char sym[max(2*RSRC_BUF_SIZE + DECODED_BUF_SIZE,
 611                     2*RSRC_BUF_SIZE + FLAG_BUF_SIZE + RAW_BUF_SIZE)];
 612
 613        char *p = sym, *pend = sym + sizeof(sym);
 614        int decode = (fmt[0] == 'R') ? 1 : 0;
 615        const struct printf_spec *specp;
 616
 617        *p++ = '[';
 618        if (res->flags & IORESOURCE_IO) {
 619                p = string(p, pend, "io  ", str_spec);
 620                specp = &io_spec;
 621        } else if (res->flags & IORESOURCE_MEM) {
 622                p = string(p, pend, "mem ", str_spec);
 623                specp = &mem_spec;
 624        } else if (res->flags & IORESOURCE_IRQ) {
 625                p = string(p, pend, "irq ", str_spec);
 626                specp = &dec_spec;
 627        } else if (res->flags & IORESOURCE_DMA) {
 628                p = string(p, pend, "dma ", str_spec);
 629                specp = &dec_spec;
 630        } else if (res->flags & IORESOURCE_BUS) {
 631                p = string(p, pend, "bus ", str_spec);
 632                specp = &bus_spec;
 633        } else {
 634                p = string(p, pend, "??? ", str_spec);
 635                specp = &mem_spec;
 636                decode = 0;
 637        }
 638        p = number(p, pend, res->start, *specp);
 639        if (res->start != res->end) {
 640                *p++ = '-';
 641                p = number(p, pend, res->end, *specp);
 642        }
 643        if (decode) {
 644                if (res->flags & IORESOURCE_MEM_64)
 645                        p = string(p, pend, " 64bit", str_spec);
 646                if (res->flags & IORESOURCE_PREFETCH)
 647                        p = string(p, pend, " pref", str_spec);
 648                if (res->flags & IORESOURCE_WINDOW)
 649                        p = string(p, pend, " window", str_spec);
 650                if (res->flags & IORESOURCE_DISABLED)
 651                        p = string(p, pend, " disabled", str_spec);
 652        } else {
 653                p = string(p, pend, " flags ", str_spec);
 654                p = number(p, pend, res->flags, flag_spec);
 655        }
 656        *p++ = ']';
 657        *p = '\0';
 658
 659        return string(buf, end, sym, spec);
 660}
 661
 662static noinline_for_stack
 663char *hex_string(char *buf, char *end, u8 *addr, struct printf_spec spec,
 664                 const char *fmt)
 665{
 666        int i, len = 1;         /* if we pass '%ph[CDN]', field witdh remains
 667                                   negative value, fallback to the default */
 668        char separator;
 669
 670        if (spec.field_width == 0)
 671                /* nothing to print */
 672                return buf;
 673
 674        if (ZERO_OR_NULL_PTR(addr))
 675                /* NULL pointer */
 676                return string(buf, end, NULL, spec);
 677
 678        switch (fmt[1]) {
 679        case 'C':
 680                separator = ':';
 681                break;
 682        case 'D':
 683                separator = '-';
 684                break;
 685        case 'N':
 686                separator = 0;
 687                break;
 688        default:
 689                separator = ' ';
 690                break;
 691        }
 692
 693        if (spec.field_width > 0)
 694                len = min_t(int, spec.field_width, 64);
 695
 696        for (i = 0; i < len && buf < end - 1; i++) {
 697                buf = hex_byte_pack(buf, addr[i]);
 698
 699                if (buf < end && separator && i != len - 1)
 700                        *buf++ = separator;
 701        }
 702
 703        return buf;
 704}
 705
 706static noinline_for_stack
 707char *mac_address_string(char *buf, char *end, u8 *addr,
 708                         struct printf_spec spec, const char *fmt)
 709{
 710        char mac_addr[sizeof("xx:xx:xx:xx:xx:xx")];
 711        char *p = mac_addr;
 712        int i;
 713        char separator;
 714        bool reversed = false;
 715
 716        switch (fmt[1]) {
 717        case 'F':
 718                separator = '-';
 719                break;
 720
 721        case 'R':
 722                reversed = true;
 723                /* fall through */
 724
 725        default:
 726                separator = ':';
 727                break;
 728        }
 729
 730        for (i = 0; i < 6; i++) {
 731                if (reversed)
 732                        p = hex_byte_pack(p, addr[5 - i]);
 733                else
 734                        p = hex_byte_pack(p, addr[i]);
 735
 736                if (fmt[0] == 'M' && i != 5)
 737                        *p++ = separator;
 738        }
 739        *p = '\0';
 740
 741        return string(buf, end, mac_addr, spec);
 742}
 743
 744static noinline_for_stack
 745char *ip4_string(char *p, const u8 *addr, const char *fmt)
 746{
 747        int i;
 748        bool leading_zeros = (fmt[0] == 'i');
 749        int index;
 750        int step;
 751
 752        switch (fmt[2]) {
 753        case 'h':
 754#ifdef __BIG_ENDIAN
 755                index = 0;
 756                step = 1;
 757#else
 758                index = 3;
 759                step = -1;
 760#endif
 761                break;
 762        case 'l':
 763                index = 3;
 764                step = -1;
 765                break;
 766        case 'n':
 767        case 'b':
 768        default:
 769                index = 0;
 770                step = 1;
 771                break;
 772        }
 773        for (i = 0; i < 4; i++) {
 774                char temp[3];   /* hold each IP quad in reverse order */
 775                int digits = put_dec_trunc8(temp, addr[index]) - temp;
 776                if (leading_zeros) {
 777                        if (digits < 3)
 778                                *p++ = '0';
 779                        if (digits < 2)
 780                                *p++ = '0';
 781                }
 782                /* reverse the digits in the quad */
 783                while (digits--)
 784                        *p++ = temp[digits];
 785                if (i < 3)
 786                        *p++ = '.';
 787                index += step;
 788        }
 789        *p = '\0';
 790
 791        return p;
 792}
 793
 794static noinline_for_stack
 795char *ip6_compressed_string(char *p, const char *addr)
 796{
 797        int i, j, range;
 798        unsigned char zerolength[8];
 799        int longest = 1;
 800        int colonpos = -1;
 801        u16 word;
 802        u8 hi, lo;
 803        bool needcolon = false;
 804        bool useIPv4;
 805        struct in6_addr in6;
 806
 807        memcpy(&in6, addr, sizeof(struct in6_addr));
 808
 809        useIPv4 = ipv6_addr_v4mapped(&in6) || ipv6_addr_is_isatap(&in6);
 810
 811        memset(zerolength, 0, sizeof(zerolength));
 812
 813        if (useIPv4)
 814                range = 6;
 815        else
 816                range = 8;
 817
 818        /* find position of longest 0 run */
 819        for (i = 0; i < range; i++) {
 820                for (j = i; j < range; j++) {
 821                        if (in6.s6_addr16[j] != 0)
 822                                break;
 823                        zerolength[i]++;
 824                }
 825        }
 826        for (i = 0; i < range; i++) {
 827                if (zerolength[i] > longest) {
 828                        longest = zerolength[i];
 829                        colonpos = i;
 830                }
 831        }
 832        if (longest == 1)               /* don't compress a single 0 */
 833                colonpos = -1;
 834
 835        /* emit address */
 836        for (i = 0; i < range; i++) {
 837                if (i == colonpos) {
 838                        if (needcolon || i == 0)
 839                                *p++ = ':';
 840                        *p++ = ':';
 841                        needcolon = false;
 842                        i += longest - 1;
 843                        continue;
 844                }
 845                if (needcolon) {
 846                        *p++ = ':';
 847                        needcolon = false;
 848                }
 849                /* hex u16 without leading 0s */
 850                word = ntohs(in6.s6_addr16[i]);
 851                hi = word >> 8;
 852                lo = word & 0xff;
 853                if (hi) {
 854                        if (hi > 0x0f)
 855                                p = hex_byte_pack(p, hi);
 856                        else
 857                                *p++ = hex_asc_lo(hi);
 858                        p = hex_byte_pack(p, lo);
 859                }
 860                else if (lo > 0x0f)
 861                        p = hex_byte_pack(p, lo);
 862                else
 863                        *p++ = hex_asc_lo(lo);
 864                needcolon = true;
 865        }
 866
 867        if (useIPv4) {
 868                if (needcolon)
 869                        *p++ = ':';
 870                p = ip4_string(p, &in6.s6_addr[12], "I4");
 871        }
 872        *p = '\0';
 873
 874        return p;
 875}
 876
 877static noinline_for_stack
 878char *ip6_string(char *p, const char *addr, const char *fmt)
 879{
 880        int i;
 881
 882        for (i = 0; i < 8; i++) {
 883                p = hex_byte_pack(p, *addr++);
 884                p = hex_byte_pack(p, *addr++);
 885                if (fmt[0] == 'I' && i != 7)
 886                        *p++ = ':';
 887        }
 888        *p = '\0';
 889
 890        return p;
 891}
 892
 893static noinline_for_stack
 894char *ip6_addr_string(char *buf, char *end, const u8 *addr,
 895                      struct printf_spec spec, const char *fmt)
 896{
 897        char ip6_addr[sizeof("xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255")];
 898
 899        if (fmt[0] == 'I' && fmt[2] == 'c')
 900                ip6_compressed_string(ip6_addr, addr);
 901        else
 902                ip6_string(ip6_addr, addr, fmt);
 903
 904        return string(buf, end, ip6_addr, spec);
 905}
 906
 907static noinline_for_stack
 908char *ip4_addr_string(char *buf, char *end, const u8 *addr,
 909                      struct printf_spec spec, const char *fmt)
 910{
 911        char ip4_addr[sizeof("255.255.255.255")];
 912
 913        ip4_string(ip4_addr, addr, fmt);
 914
 915        return string(buf, end, ip4_addr, spec);
 916}
 917
 918static noinline_for_stack
 919char *uuid_string(char *buf, char *end, const u8 *addr,
 920                  struct printf_spec spec, const char *fmt)
 921{
 922        char uuid[sizeof("xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx")];
 923        char *p = uuid;
 924        int i;
 925        static const u8 be[16] = {0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15};
 926        static const u8 le[16] = {3,2,1,0,5,4,7,6,8,9,10,11,12,13,14,15};
 927        const u8 *index = be;
 928        bool uc = false;
 929
 930        switch (*(++fmt)) {
 931        case 'L':
 932                uc = true;              /* fall-through */
 933        case 'l':
 934                index = le;
 935                break;
 936        case 'B':
 937                uc = true;
 938                break;
 939        }
 940
 941        for (i = 0; i < 16; i++) {
 942                p = hex_byte_pack(p, addr[index[i]]);
 943                switch (i) {
 944                case 3:
 945                case 5:
 946                case 7:
 947                case 9:
 948                        *p++ = '-';
 949                        break;
 950                }
 951        }
 952
 953        *p = 0;
 954
 955        if (uc) {
 956                p = uuid;
 957                do {
 958                        *p = toupper(*p);
 959                } while (*(++p));
 960        }
 961
 962        return string(buf, end, uuid, spec);
 963}
 964
 965static
 966char *netdev_feature_string(char *buf, char *end, const u8 *addr,
 967                      struct printf_spec spec)
 968{
 969        spec.flags |= SPECIAL | SMALL | ZEROPAD;
 970        if (spec.field_width == -1)
 971                spec.field_width = 2 + 2 * sizeof(netdev_features_t);
 972        spec.base = 16;
 973
 974        return number(buf, end, *(const netdev_features_t *)addr, spec);
 975}
 976
 977int kptr_restrict __read_mostly;
 978
 979/*
 980 * Show a '%p' thing.  A kernel extension is that the '%p' is followed
 981 * by an extra set of alphanumeric characters that are extended format
 982 * specifiers.
 983 *
 984 * Right now we handle:
 985 *
 986 * - 'F' For symbolic function descriptor pointers with offset
 987 * - 'f' For simple symbolic function names without offset
 988 * - 'S' For symbolic direct pointers with offset
 989 * - 's' For symbolic direct pointers without offset
 990 * - 'B' For backtraced symbolic direct pointers with offset
 991 * - 'R' For decoded struct resource, e.g., [mem 0x0-0x1f 64bit pref]
 992 * - 'r' For raw struct resource, e.g., [mem 0x0-0x1f flags 0x201]
 993 * - 'M' For a 6-byte MAC address, it prints the address in the
 994 *       usual colon-separated hex notation
 995 * - 'm' For a 6-byte MAC address, it prints the hex address without colons
 996 * - 'MF' For a 6-byte MAC FDDI address, it prints the address
 997 *       with a dash-separated hex notation
 998 * - '[mM]R' For a 6-byte MAC address, Reverse order (Bluetooth)
 999 * - 'I' [46] for IPv4/IPv6 addresses printed in the usual way
1000 *       IPv4 uses dot-separated decimal without leading 0's (1.2.3.4)
1001 *       IPv6 uses colon separated network-order 16 bit hex with leading 0's
1002 * - 'i' [46] for 'raw' IPv4/IPv6 addresses
1003 *       IPv6 omits the colons (01020304...0f)
1004 *       IPv4 uses dot-separated decimal with leading 0's (010.123.045.006)
1005 * - '[Ii]4[hnbl]' IPv4 addresses in host, network, big or little endian order
1006 * - 'I6c' for IPv6 addresses printed as specified by
1007 *       http://tools.ietf.org/html/rfc5952
1008 * - 'U' For a 16 byte UUID/GUID, it prints the UUID/GUID in the form
1009 *       "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx"
1010 *       Options for %pU are:
1011 *         b big endian lower case hex (default)
1012 *         B big endian UPPER case hex
1013 *         l little endian lower case hex
1014 *         L little endian UPPER case hex
1015 *           big endian output byte order is:
1016 *             [0][1][2][3]-[4][5]-[6][7]-[8][9]-[10][11][12][13][14][15]
1017 *           little endian output byte order is:
1018 *             [3][2][1][0]-[5][4]-[7][6]-[8][9]-[10][11][12][13][14][15]
1019 * - 'V' For a struct va_format which contains a format string * and va_list *,
1020 *       call vsnprintf(->format, *->va_list).
1021 *       Implements a "recursive vsnprintf".
1022 *       Do not use this feature without some mechanism to verify the
1023 *       correctness of the format string and va_list arguments.
1024 * - 'K' For a kernel pointer that should be hidden from unprivileged users
1025 * - 'NF' For a netdev_features_t
1026 * - 'h[CDN]' For a variable-length buffer, it prints it as a hex string with
1027 *            a certain separator (' ' by default):
1028 *              C colon
1029 *              D dash
1030 *              N no separator
1031 *            The maximum supported length is 64 bytes of the input. Consider
1032 *            to use print_hex_dump() for the larger input.
1033 *
1034 * Note: The difference between 'S' and 'F' is that on ia64 and ppc64
1035 * function pointers are really function descriptors, which contain a
1036 * pointer to the real address.
1037 */
1038static noinline_for_stack
1039char *pointer(const char *fmt, char *buf, char *end, void *ptr,
1040              struct printf_spec spec)
1041{
1042        int default_width = 2 * sizeof(void *) + (spec.flags & SPECIAL ? 2 : 0);
1043
1044        if (!ptr && *fmt != 'K') {
1045                /*
1046                 * Print (null) with the same width as a pointer so it makes
1047                 * tabular output look nice.
1048                 */
1049                if (spec.field_width == -1)
1050                        spec.field_width = default_width;
1051                return string(buf, end, "(null)", spec);
1052        }
1053
1054        switch (*fmt) {
1055        case 'F':
1056        case 'f':
1057                ptr = dereference_function_descriptor(ptr);
1058                /* Fallthrough */
1059        case 'S':
1060        case 's':
1061        case 'B':
1062                return symbol_string(buf, end, ptr, spec, *fmt);
1063        case 'R':
1064        case 'r':
1065                return resource_string(buf, end, ptr, spec, fmt);
1066        case 'h':
1067                return hex_string(buf, end, ptr, spec, fmt);
1068        case 'M':                       /* Colon separated: 00:01:02:03:04:05 */
1069        case 'm':                       /* Contiguous: 000102030405 */
1070                                        /* [mM]F (FDDI) */
1071                                        /* [mM]R (Reverse order; Bluetooth) */
1072                return mac_address_string(buf, end, ptr, spec, fmt);
1073        case 'I':                       /* Formatted IP supported
1074                                         * 4:   1.2.3.4
1075                                         * 6:   0001:0203:...:0708
1076                                         * 6c:  1::708 or 1::1.2.3.4
1077                                         */
1078        case 'i':                       /* Contiguous:
1079                                         * 4:   001.002.003.004
1080                                         * 6:   000102...0f
1081                                         */
1082                switch (fmt[1]) {
1083                case '6':
1084                        return ip6_addr_string(buf, end, ptr, spec, fmt);
1085                case '4':
1086                        return ip4_addr_string(buf, end, ptr, spec, fmt);
1087                }
1088                break;
1089        case 'U':
1090                return uuid_string(buf, end, ptr, spec, fmt);
1091        case 'V':
1092                {
1093                        va_list va;
1094
1095                        va_copy(va, *((struct va_format *)ptr)->va);
1096                        buf += vsnprintf(buf, end > buf ? end - buf : 0,
1097                                         ((struct va_format *)ptr)->fmt, va);
1098                        va_end(va);
1099                        return buf;
1100                }
1101        case 'K':
1102                /*
1103                 * %pK cannot be used in IRQ context because its test
1104                 * for CAP_SYSLOG would be meaningless.
1105                 */
1106                if (kptr_restrict && (in_irq() || in_serving_softirq() ||
1107                                      in_nmi())) {
1108                        if (spec.field_width == -1)
1109                                spec.field_width = default_width;
1110                        return string(buf, end, "pK-error", spec);
1111                }
1112                if (!((kptr_restrict == 0) ||
1113                      (kptr_restrict == 1 &&
1114                       has_capability_noaudit(current, CAP_SYSLOG))))
1115                        ptr = NULL;
1116                break;
1117        case 'N':
1118                switch (fmt[1]) {
1119                case 'F':
1120                        return netdev_feature_string(buf, end, ptr, spec);
1121                }
1122                break;
1123        }
1124        spec.flags |= SMALL;
1125        if (spec.field_width == -1) {
1126                spec.field_width = default_width;
1127                spec.flags |= ZEROPAD;
1128        }
1129        spec.base = 16;
1130
1131        return number(buf, end, (unsigned long) ptr, spec);
1132}
1133
1134/*
1135 * Helper function to decode printf style format.
1136 * Each call decode a token from the format and return the
1137 * number of characters read (or likely the delta where it wants
1138 * to go on the next call).
1139 * The decoded token is returned through the parameters
1140 *
1141 * 'h', 'l', or 'L' for integer fields
1142 * 'z' support added 23/7/1999 S.H.
1143 * 'z' changed to 'Z' --davidm 1/25/99
1144 * 't' added for ptrdiff_t
1145 *
1146 * @fmt: the format string
1147 * @type of the token returned
1148 * @flags: various flags such as +, -, # tokens..
1149 * @field_width: overwritten width
1150 * @base: base of the number (octal, hex, ...)
1151 * @precision: precision of a number
1152 * @qualifier: qualifier of a number (long, size_t, ...)
1153 */
1154static noinline_for_stack
1155int format_decode(const char *fmt, struct printf_spec *spec)
1156{
1157        const char *start = fmt;
1158
1159        /* we finished early by reading the field width */
1160        if (spec->type == FORMAT_TYPE_WIDTH) {
1161                if (spec->field_width < 0) {
1162                        spec->field_width = -spec->field_width;
1163                        spec->flags |= LEFT;
1164                }
1165                spec->type = FORMAT_TYPE_NONE;
1166                goto precision;
1167        }
1168
1169        /* we finished early by reading the precision */
1170        if (spec->type == FORMAT_TYPE_PRECISION) {
1171                if (spec->precision < 0)
1172                        spec->precision = 0;
1173
1174                spec->type = FORMAT_TYPE_NONE;
1175                goto qualifier;
1176        }
1177
1178        /* By default */
1179        spec->type = FORMAT_TYPE_NONE;
1180
1181        for (; *fmt ; ++fmt) {
1182                if (*fmt == '%')
1183                        break;
1184        }
1185
1186        /* Return the current non-format string */
1187        if (fmt != start || !*fmt)
1188                return fmt - start;
1189
1190        /* Process flags */
1191        spec->flags = 0;
1192
1193        while (1) { /* this also skips first '%' */
1194                bool found = true;
1195
1196                ++fmt;
1197
1198                switch (*fmt) {
1199                case '-': spec->flags |= LEFT;    break;
1200                case '+': spec->flags |= PLUS;    break;
1201                case ' ': spec->flags |= SPACE;   break;
1202                case '#': spec->flags |= SPECIAL; break;
1203                case '0': spec->flags |= ZEROPAD; break;
1204                default:  found = false;
1205                }
1206
1207                if (!found)
1208                        break;
1209        }
1210
1211        /* get field width */
1212        spec->field_width = -1;
1213
1214        if (isdigit(*fmt))
1215                spec->field_width = skip_atoi(&fmt);
1216        else if (*fmt == '*') {
1217                /* it's the next argument */
1218                spec->type = FORMAT_TYPE_WIDTH;
1219                return ++fmt - start;
1220        }
1221
1222precision:
1223        /* get the precision */
1224        spec->precision = -1;
1225        if (*fmt == '.') {
1226                ++fmt;
1227                if (isdigit(*fmt)) {
1228                        spec->precision = skip_atoi(&fmt);
1229                        if (spec->precision < 0)
1230                                spec->precision = 0;
1231                } else if (*fmt == '*') {
1232                        /* it's the next argument */
1233                        spec->type = FORMAT_TYPE_PRECISION;
1234                        return ++fmt - start;
1235                }
1236        }
1237
1238qualifier:
1239        /* get the conversion qualifier */
1240        spec->qualifier = -1;
1241        if (*fmt == 'h' || _tolower(*fmt) == 'l' ||
1242            _tolower(*fmt) == 'z' || *fmt == 't') {
1243                spec->qualifier = *fmt++;
1244                if (unlikely(spec->qualifier == *fmt)) {
1245                        if (spec->qualifier == 'l') {
1246                                spec->qualifier = 'L';
1247                                ++fmt;
1248                        } else if (spec->qualifier == 'h') {
1249                                spec->qualifier = 'H';
1250                                ++fmt;
1251                        }
1252                }
1253        }
1254
1255        /* default base */
1256        spec->base = 10;
1257        switch (*fmt) {
1258        case 'c':
1259                spec->type = FORMAT_TYPE_CHAR;
1260                return ++fmt - start;
1261
1262        case 's':
1263                spec->type = FORMAT_TYPE_STR;
1264                return ++fmt - start;
1265
1266        case 'p':
1267                spec->type = FORMAT_TYPE_PTR;
1268                return fmt - start;
1269                /* skip alnum */
1270
1271        case 'n':
1272                spec->type = FORMAT_TYPE_NRCHARS;
1273                return ++fmt - start;
1274
1275        case '%':
1276                spec->type = FORMAT_TYPE_PERCENT_CHAR;
1277                return ++fmt - start;
1278
1279        /* integer number formats - set up the flags and "break" */
1280        case 'o':
1281                spec->base = 8;
1282                break;
1283
1284        case 'x':
1285                spec->flags |= SMALL;
1286
1287        case 'X':
1288                spec->base = 16;
1289                break;
1290
1291        case 'd':
1292        case 'i':
1293                spec->flags |= SIGN;
1294        case 'u':
1295                break;
1296
1297        default:
1298                spec->type = FORMAT_TYPE_INVALID;
1299                return fmt - start;
1300        }
1301
1302        if (spec->qualifier == 'L')
1303                spec->type = FORMAT_TYPE_LONG_LONG;
1304        else if (spec->qualifier == 'l') {
1305                if (spec->flags & SIGN)
1306                        spec->type = FORMAT_TYPE_LONG;
1307                else
1308                        spec->type = FORMAT_TYPE_ULONG;
1309        } else if (_tolower(spec->qualifier) == 'z') {
1310                spec->type = FORMAT_TYPE_SIZE_T;
1311        } else if (spec->qualifier == 't') {
1312                spec->type = FORMAT_TYPE_PTRDIFF;
1313        } else if (spec->qualifier == 'H') {
1314                if (spec->flags & SIGN)
1315                        spec->type = FORMAT_TYPE_BYTE;
1316                else
1317                        spec->type = FORMAT_TYPE_UBYTE;
1318        } else if (spec->qualifier == 'h') {
1319                if (spec->flags & SIGN)
1320                        spec->type = FORMAT_TYPE_SHORT;
1321                else
1322                        spec->type = FORMAT_TYPE_USHORT;
1323        } else {
1324                if (spec->flags & SIGN)
1325                        spec->type = FORMAT_TYPE_INT;
1326                else
1327                        spec->type = FORMAT_TYPE_UINT;
1328        }
1329
1330        return ++fmt - start;
1331}
1332
1333/**
1334 * vsnprintf - Format a string and place it in a buffer
1335 * @buf: The buffer to place the result into
1336 * @size: The size of the buffer, including the trailing null space
1337 * @fmt: The format string to use
1338 * @args: Arguments for the format string
1339 *
1340 * This function follows C99 vsnprintf, but has some extensions:
1341 * %pS output the name of a text symbol with offset
1342 * %ps output the name of a text symbol without offset
1343 * %pF output the name of a function pointer with its offset
1344 * %pf output the name of a function pointer without its offset
1345 * %pB output the name of a backtrace symbol with its offset
1346 * %pR output the address range in a struct resource with decoded flags
1347 * %pr output the address range in a struct resource with raw flags
1348 * %pM output a 6-byte MAC address with colons
1349 * %pMR output a 6-byte MAC address with colons in reversed order
1350 * %pMF output a 6-byte MAC address with dashes
1351 * %pm output a 6-byte MAC address without colons
1352 * %pmR output a 6-byte MAC address without colons in reversed order
1353 * %pI4 print an IPv4 address without leading zeros
1354 * %pi4 print an IPv4 address with leading zeros
1355 * %pI6 print an IPv6 address with colons
1356 * %pi6 print an IPv6 address without colons
1357 * %pI6c print an IPv6 address as specified by RFC 5952
1358 * %pU[bBlL] print a UUID/GUID in big or little endian using lower or upper
1359 *   case.
1360 * %*ph[CDN] a variable-length hex string with a separator (supports up to 64
1361 *           bytes of the input)
1362 * %n is ignored
1363 *
1364 * ** Please update Documentation/printk-formats.txt when making changes **
1365 *
1366 * The return value is the number of characters which would
1367 * be generated for the given input, excluding the trailing
1368 * '\0', as per ISO C99. If you want to have the exact
1369 * number of characters written into @buf as return value
1370 * (not including the trailing '\0'), use vscnprintf(). If the
1371 * return is greater than or equal to @size, the resulting
1372 * string is truncated.
1373 *
1374 * If you're not already dealing with a va_list consider using snprintf().
1375 */
1376int vsnprintf(char *buf, size_t size, const char *fmt, va_list args)
1377{
1378        unsigned long long num;
1379        char *str, *end;
1380        struct printf_spec spec = {0};
1381
1382        /* Reject out-of-range values early.  Large positive sizes are
1383           used for unknown buffer sizes. */
1384        if (WARN_ON_ONCE((int) size < 0))
1385                return 0;
1386
1387        str = buf;
1388        end = buf + size;
1389
1390        /* Make sure end is always >= buf */
1391        if (end < buf) {
1392                end = ((void *)-1);
1393                size = end - buf;
1394        }
1395
1396        while (*fmt) {
1397                const char *old_fmt = fmt;
1398                int read = format_decode(fmt, &spec);
1399
1400                fmt += read;
1401
1402                switch (spec.type) {
1403                case FORMAT_TYPE_NONE: {
1404                        int copy = read;
1405                        if (str < end) {
1406                                if (copy > end - str)
1407                                        copy = end - str;
1408                                memcpy(str, old_fmt, copy);
1409                        }
1410                        str += read;
1411                        break;
1412                }
1413
1414                case FORMAT_TYPE_WIDTH:
1415                        spec.field_width = va_arg(args, int);
1416                        break;
1417
1418                case FORMAT_TYPE_PRECISION:
1419                        spec.precision = va_arg(args, int);
1420                        break;
1421
1422                case FORMAT_TYPE_CHAR: {
1423                        char c;
1424
1425                        if (!(spec.flags & LEFT)) {
1426                                while (--spec.field_width > 0) {
1427                                        if (str < end)
1428                                                *str = ' ';
1429                                        ++str;
1430
1431                                }
1432                        }
1433                        c = (unsigned char) va_arg(args, int);
1434                        if (str < end)
1435                                *str = c;
1436                        ++str;
1437                        while (--spec.field_width > 0) {
1438                                if (str < end)
1439                                        *str = ' ';
1440                                ++str;
1441                        }
1442                        break;
1443                }
1444
1445                case FORMAT_TYPE_STR:
1446                        str = string(str, end, va_arg(args, char *), spec);
1447                        break;
1448
1449                case FORMAT_TYPE_PTR:
1450                        str = pointer(fmt+1, str, end, va_arg(args, void *),
1451                                      spec);
1452                        while (isalnum(*fmt))
1453                                fmt++;
1454                        break;
1455
1456                case FORMAT_TYPE_PERCENT_CHAR:
1457                        if (str < end)
1458                                *str = '%';
1459                        ++str;
1460                        break;
1461
1462                case FORMAT_TYPE_INVALID:
1463                        if (str < end)
1464                                *str = '%';
1465                        ++str;
1466                        break;
1467
1468                case FORMAT_TYPE_NRCHARS: {
1469                        u8 qualifier = spec.qualifier;
1470
1471                        if (qualifier == 'l') {
1472                                long *ip = va_arg(args, long *);
1473                                *ip = (str - buf);
1474                        } else if (_tolower(qualifier) == 'z') {
1475                                size_t *ip = va_arg(args, size_t *);
1476                                *ip = (str - buf);
1477                        } else {
1478                                int *ip = va_arg(args, int *);
1479                                *ip = (str - buf);
1480                        }
1481                        break;
1482                }
1483
1484                default:
1485                        switch (spec.type) {
1486                        case FORMAT_TYPE_LONG_LONG:
1487                                num = va_arg(args, long long);
1488                                break;
1489                        case FORMAT_TYPE_ULONG:
1490                                num = va_arg(args, unsigned long);
1491                                break;
1492                        case FORMAT_TYPE_LONG:
1493                                num = va_arg(args, long);
1494                                break;
1495                        case FORMAT_TYPE_SIZE_T:
1496                                if (spec.flags & SIGN)
1497                                        num = va_arg(args, ssize_t);
1498                                else
1499                                        num = va_arg(args, size_t);
1500                                break;
1501                        case FORMAT_TYPE_PTRDIFF:
1502                                num = va_arg(args, ptrdiff_t);
1503                                break;
1504                        case FORMAT_TYPE_UBYTE:
1505                                num = (unsigned char) va_arg(args, int);
1506                                break;
1507                        case FORMAT_TYPE_BYTE:
1508                                num = (signed char) va_arg(args, int);
1509                                break;
1510                        case FORMAT_TYPE_USHORT:
1511                                num = (unsigned short) va_arg(args, int);
1512                                break;
1513                        case FORMAT_TYPE_SHORT:
1514                                num = (short) va_arg(args, int);
1515                                break;
1516                        case FORMAT_TYPE_INT:
1517                                num = (int) va_arg(args, int);
1518                                break;
1519                        default:
1520                                num = va_arg(args, unsigned int);
1521                        }
1522
1523                        str = number(str, end, num, spec);
1524                }
1525        }
1526
1527        if (size > 0) {
1528                if (str < end)
1529                        *str = '\0';
1530                else
1531                        end[-1] = '\0';
1532        }
1533
1534        /* the trailing null byte doesn't count towards the total */
1535        return str-buf;
1536
1537}
1538EXPORT_SYMBOL(vsnprintf);
1539
1540/**
1541 * vscnprintf - Format a string and place it in a buffer
1542 * @buf: The buffer to place the result into
1543 * @size: The size of the buffer, including the trailing null space
1544 * @fmt: The format string to use
1545 * @args: Arguments for the format string
1546 *
1547 * The return value is the number of characters which have been written into
1548 * the @buf not including the trailing '\0'. If @size is == 0 the function
1549 * returns 0.
1550 *
1551 * If you're not already dealing with a va_list consider using scnprintf().
1552 *
1553 * See the vsnprintf() documentation for format string extensions over C99.
1554 */
1555int vscnprintf(char *buf, size_t size, const char *fmt, va_list args)
1556{
1557        int i;
1558
1559        i = vsnprintf(buf, size, fmt, args);
1560
1561        if (likely(i < size))
1562                return i;
1563        if (size != 0)
1564                return size - 1;
1565        return 0;
1566}
1567EXPORT_SYMBOL(vscnprintf);
1568
1569/**
1570 * snprintf - Format a string and place it in a buffer
1571 * @buf: The buffer to place the result into
1572 * @size: The size of the buffer, including the trailing null space
1573 * @fmt: The format string to use
1574 * @...: Arguments for the format string
1575 *
1576 * The return value is the number of characters which would be
1577 * generated for the given input, excluding the trailing null,
1578 * as per ISO C99.  If the return is greater than or equal to
1579 * @size, the resulting string is truncated.
1580 *
1581 * See the vsnprintf() documentation for format string extensions over C99.
1582 */
1583int snprintf(char *buf, size_t size, const char *fmt, ...)
1584{
1585        va_list args;
1586        int i;
1587
1588        va_start(args, fmt);
1589        i = vsnprintf(buf, size, fmt, args);
1590        va_end(args);
1591
1592        return i;
1593}
1594EXPORT_SYMBOL(snprintf);
1595
1596/**
1597 * scnprintf - Format a string and place it in a buffer
1598 * @buf: The buffer to place the result into
1599 * @size: The size of the buffer, including the trailing null space
1600 * @fmt: The format string to use
1601 * @...: Arguments for the format string
1602 *
1603 * The return value is the number of characters written into @buf not including
1604 * the trailing '\0'. If @size is == 0 the function returns 0.
1605 */
1606
1607int scnprintf(char *buf, size_t size, const char *fmt, ...)
1608{
1609        va_list args;
1610        int i;
1611
1612        va_start(args, fmt);
1613        i = vscnprintf(buf, size, fmt, args);
1614        va_end(args);
1615
1616        return i;
1617}
1618EXPORT_SYMBOL(scnprintf);
1619
1620/**
1621 * vsprintf - Format a string and place it in a buffer
1622 * @buf: The buffer to place the result into
1623 * @fmt: The format string to use
1624 * @args: Arguments for the format string
1625 *
1626 * The function returns the number of characters written
1627 * into @buf. Use vsnprintf() or vscnprintf() in order to avoid
1628 * buffer overflows.
1629 *
1630 * If you're not already dealing with a va_list consider using sprintf().
1631 *
1632 * See the vsnprintf() documentation for format string extensions over C99.
1633 */
1634int vsprintf(char *buf, const char *fmt, va_list args)
1635{
1636        return vsnprintf(buf, INT_MAX, fmt, args);
1637}
1638EXPORT_SYMBOL(vsprintf);
1639
1640/**
1641 * sprintf - Format a string and place it in a buffer
1642 * @buf: The buffer to place the result into
1643 * @fmt: The format string to use
1644 * @...: Arguments for the format string
1645 *
1646 * The function returns the number of characters written
1647 * into @buf. Use snprintf() or scnprintf() in order to avoid
1648 * buffer overflows.
1649 *
1650 * See the vsnprintf() documentation for format string extensions over C99.
1651 */
1652int sprintf(char *buf, const char *fmt, ...)
1653{
1654        va_list args;
1655        int i;
1656
1657        va_start(args, fmt);
1658        i = vsnprintf(buf, INT_MAX, fmt, args);
1659        va_end(args);
1660
1661        return i;
1662}
1663EXPORT_SYMBOL(sprintf);
1664
1665#ifdef CONFIG_BINARY_PRINTF
1666/*
1667 * bprintf service:
1668 * vbin_printf() - VA arguments to binary data
1669 * bstr_printf() - Binary data to text string
1670 */
1671
1672/**
1673 * vbin_printf - Parse a format string and place args' binary value in a buffer
1674 * @bin_buf: The buffer to place args' binary value
1675 * @size: The size of the buffer(by words(32bits), not characters)
1676 * @fmt: The format string to use
1677 * @args: Arguments for the format string
1678 *
1679 * The format follows C99 vsnprintf, except %n is ignored, and its argument
1680 * is skiped.
1681 *
1682 * The return value is the number of words(32bits) which would be generated for
1683 * the given input.
1684 *
1685 * NOTE:
1686 * If the return value is greater than @size, the resulting bin_buf is NOT
1687 * valid for bstr_printf().
1688 */
1689int vbin_printf(u32 *bin_buf, size_t size, const char *fmt, va_list args)
1690{
1691        struct printf_spec spec = {0};
1692        char *str, *end;
1693
1694        str = (char *)bin_buf;
1695        end = (char *)(bin_buf + size);
1696
1697#define save_arg(type)                                                  \
1698do {                                                                    \
1699        if (sizeof(type) == 8) {                                        \
1700                unsigned long long value;                               \
1701                str = PTR_ALIGN(str, sizeof(u32));                      \
1702                value = va_arg(args, unsigned long long);               \
1703                if (str + sizeof(type) <= end) {                        \
1704                        *(u32 *)str = *(u32 *)&value;                   \
1705                        *(u32 *)(str + 4) = *((u32 *)&value + 1);       \
1706                }                                                       \
1707        } else {                                                        \
1708                unsigned long value;                                    \
1709                str = PTR_ALIGN(str, sizeof(type));                     \
1710                value = va_arg(args, int);                              \
1711                if (str + sizeof(type) <= end)                          \
1712                        *(typeof(type) *)str = (type)value;             \
1713        }                                                               \
1714        str += sizeof(type);                                            \
1715} while (0)
1716
1717        while (*fmt) {
1718                int read = format_decode(fmt, &spec);
1719
1720                fmt += read;
1721
1722                switch (spec.type) {
1723                case FORMAT_TYPE_NONE:
1724                case FORMAT_TYPE_INVALID:
1725                case FORMAT_TYPE_PERCENT_CHAR:
1726                        break;
1727
1728                case FORMAT_TYPE_WIDTH:
1729                case FORMAT_TYPE_PRECISION:
1730                        save_arg(int);
1731                        break;
1732
1733                case FORMAT_TYPE_CHAR:
1734                        save_arg(char);
1735                        break;
1736
1737                case FORMAT_TYPE_STR: {
1738                        const char *save_str = va_arg(args, char *);
1739                        size_t len;
1740
1741                        if ((unsigned long)save_str > (unsigned long)-PAGE_SIZE
1742                                        || (unsigned long)save_str < PAGE_SIZE)
1743                                save_str = "(null)";
1744                        len = strlen(save_str) + 1;
1745                        if (str + len < end)
1746                                memcpy(str, save_str, len);
1747                        str += len;
1748                        break;
1749                }
1750
1751                case FORMAT_TYPE_PTR:
1752                        save_arg(void *);
1753                        /* skip all alphanumeric pointer suffixes */
1754                        while (isalnum(*fmt))
1755                                fmt++;
1756                        break;
1757
1758                case FORMAT_TYPE_NRCHARS: {
1759                        /* skip %n 's argument */
1760                        u8 qualifier = spec.qualifier;
1761                        void *skip_arg;
1762                        if (qualifier == 'l')
1763                                skip_arg = va_arg(args, long *);
1764                        else if (_tolower(qualifier) == 'z')
1765                                skip_arg = va_arg(args, size_t *);
1766                        else
1767                                skip_arg = va_arg(args, int *);
1768                        break;
1769                }
1770
1771                default:
1772                        switch (spec.type) {
1773
1774                        case FORMAT_TYPE_LONG_LONG:
1775                                save_arg(long long);
1776                                break;
1777                        case FORMAT_TYPE_ULONG:
1778                        case FORMAT_TYPE_LONG:
1779                                save_arg(unsigned long);
1780                                break;
1781                        case FORMAT_TYPE_SIZE_T:
1782                                save_arg(size_t);
1783                                break;
1784                        case FORMAT_TYPE_PTRDIFF:
1785                                save_arg(ptrdiff_t);
1786                                break;
1787                        case FORMAT_TYPE_UBYTE:
1788                        case FORMAT_TYPE_BYTE:
1789                                save_arg(char);
1790                                break;
1791                        case FORMAT_TYPE_USHORT:
1792                        case FORMAT_TYPE_SHORT:
1793                                save_arg(short);
1794                                break;
1795                        default:
1796                                save_arg(int);
1797                        }
1798                }
1799        }
1800
1801        return (u32 *)(PTR_ALIGN(str, sizeof(u32))) - bin_buf;
1802#undef save_arg
1803}
1804EXPORT_SYMBOL_GPL(vbin_printf);
1805
1806/**
1807 * bstr_printf - Format a string from binary arguments and place it in a buffer
1808 * @buf: The buffer to place the result into
1809 * @size: The size of the buffer, including the trailing null space
1810 * @fmt: The format string to use
1811 * @bin_buf: Binary arguments for the format string
1812 *
1813 * This function like C99 vsnprintf, but the difference is that vsnprintf gets
1814 * arguments from stack, and bstr_printf gets arguments from @bin_buf which is
1815 * a binary buffer that generated by vbin_printf.
1816 *
1817 * The format follows C99 vsnprintf, but has some extensions:
1818 *  see vsnprintf comment for details.
1819 *
1820 * The return value is the number of characters which would
1821 * be generated for the given input, excluding the trailing
1822 * '\0', as per ISO C99. If you want to have the exact
1823 * number of characters written into @buf as return value
1824 * (not including the trailing '\0'), use vscnprintf(). If the
1825 * return is greater than or equal to @size, the resulting
1826 * string is truncated.
1827 */
1828int bstr_printf(char *buf, size_t size, const char *fmt, const u32 *bin_buf)
1829{
1830        struct printf_spec spec = {0};
1831        char *str, *end;
1832        const char *args = (const char *)bin_buf;
1833
1834        if (WARN_ON_ONCE((int) size < 0))
1835                return 0;
1836
1837        str = buf;
1838        end = buf + size;
1839
1840#define get_arg(type)                                                   \
1841({                                                                      \
1842        typeof(type) value;                                             \
1843        if (sizeof(type) == 8) {                                        \
1844                args = PTR_ALIGN(args, sizeof(u32));                    \
1845                *(u32 *)&value = *(u32 *)args;                          \
1846                *((u32 *)&value + 1) = *(u32 *)(args + 4);              \
1847        } else {                                                        \
1848                args = PTR_ALIGN(args, sizeof(type));                   \
1849                value = *(typeof(type) *)args;                          \
1850        }                                                               \
1851        args += sizeof(type);                                           \
1852        value;                                                          \
1853})
1854
1855        /* Make sure end is always >= buf */
1856        if (end < buf) {
1857                end = ((void *)-1);
1858                size = end - buf;
1859        }
1860
1861        while (*fmt) {
1862                const char *old_fmt = fmt;
1863                int read = format_decode(fmt, &spec);
1864
1865                fmt += read;
1866
1867                switch (spec.type) {
1868                case FORMAT_TYPE_NONE: {
1869                        int copy = read;
1870                        if (str < end) {
1871                                if (copy > end - str)
1872                                        copy = end - str;
1873                                memcpy(str, old_fmt, copy);
1874                        }
1875                        str += read;
1876                        break;
1877                }
1878
1879                case FORMAT_TYPE_WIDTH:
1880                        spec.field_width = get_arg(int);
1881                        break;
1882
1883                case FORMAT_TYPE_PRECISION:
1884                        spec.precision = get_arg(int);
1885                        break;
1886
1887                case FORMAT_TYPE_CHAR: {
1888                        char c;
1889
1890                        if (!(spec.flags & LEFT)) {
1891                                while (--spec.field_width > 0) {
1892                                        if (str < end)
1893                                                *str = ' ';
1894                                        ++str;
1895                                }
1896                        }
1897                        c = (unsigned char) get_arg(char);
1898                        if (str < end)
1899                                *str = c;
1900                        ++str;
1901                        while (--spec.field_width > 0) {
1902                                if (str < end)
1903                                        *str = ' ';
1904                                ++str;
1905                        }
1906                        break;
1907                }
1908
1909                case FORMAT_TYPE_STR: {
1910                        const char *str_arg = args;
1911                        args += strlen(str_arg) + 1;
1912                        str = string(str, end, (char *)str_arg, spec);
1913                        break;
1914                }
1915
1916                case FORMAT_TYPE_PTR:
1917                        str = pointer(fmt+1, str, end, get_arg(void *), spec);
1918                        while (isalnum(*fmt))
1919                                fmt++;
1920                        break;
1921
1922                case FORMAT_TYPE_PERCENT_CHAR:
1923                case FORMAT_TYPE_INVALID:
1924                        if (str < end)
1925                                *str = '%';
1926                        ++str;
1927                        break;
1928
1929                case FORMAT_TYPE_NRCHARS:
1930                        /* skip */
1931                        break;
1932
1933                default: {
1934                        unsigned long long num;
1935
1936                        switch (spec.type) {
1937
1938                        case FORMAT_TYPE_LONG_LONG:
1939                                num = get_arg(long long);
1940                                break;
1941                        case FORMAT_TYPE_ULONG:
1942                        case FORMAT_TYPE_LONG:
1943                                num = get_arg(unsigned long);
1944                                break;
1945                        case FORMAT_TYPE_SIZE_T:
1946                                num = get_arg(size_t);
1947                                break;
1948                        case FORMAT_TYPE_PTRDIFF:
1949                                num = get_arg(ptrdiff_t);
1950                                break;
1951                        case FORMAT_TYPE_UBYTE:
1952                                num = get_arg(unsigned char);
1953                                break;
1954                        case FORMAT_TYPE_BYTE:
1955                                num = get_arg(signed char);
1956                                break;
1957                        case FORMAT_TYPE_USHORT:
1958                                num = get_arg(unsigned short);
1959                                break;
1960                        case FORMAT_TYPE_SHORT:
1961                                num = get_arg(short);
1962                                break;
1963                        case FORMAT_TYPE_UINT:
1964                                num = get_arg(unsigned int);
1965                                break;
1966                        default:
1967                                num = get_arg(int);
1968                        }
1969
1970                        str = number(str, end, num, spec);
1971                } /* default: */
1972                } /* switch(spec.type) */
1973        } /* while(*fmt) */
1974
1975        if (size > 0) {
1976                if (str < end)
1977                        *str = '\0';
1978                else
1979                        end[-1] = '\0';
1980        }
1981
1982#undef get_arg
1983
1984        /* the trailing null byte doesn't count towards the total */
1985        return str - buf;
1986}
1987EXPORT_SYMBOL_GPL(bstr_printf);
1988
1989/**
1990 * bprintf - Parse a format string and place args' binary value in a buffer
1991 * @bin_buf: The buffer to place args' binary value
1992 * @size: The size of the buffer(by words(32bits), not characters)
1993 * @fmt: The format string to use
1994 * @...: Arguments for the format string
1995 *
1996 * The function returns the number of words(u32) written
1997 * into @bin_buf.
1998 */
1999int bprintf(u32 *bin_buf, size_t size, const char *fmt, ...)
2000{
2001        va_list args;
2002        int ret;
2003
2004        va_start(args, fmt);
2005        ret = vbin_printf(bin_buf, size, fmt, args);
2006        va_end(args);
2007
2008        return ret;
2009}
2010EXPORT_SYMBOL_GPL(bprintf);
2011
2012#endif /* CONFIG_BINARY_PRINTF */
2013
2014/**
2015 * vsscanf - Unformat a buffer into a list of arguments
2016 * @buf:        input buffer
2017 * @fmt:        format of buffer
2018 * @args:       arguments
2019 */
2020int vsscanf(const char *buf, const char *fmt, va_list args)
2021{
2022        const char *str = buf;
2023        char *next;
2024        char digit;
2025        int num = 0;
2026        u8 qualifier;
2027        unsigned int base;
2028        union {
2029                long long s;
2030                unsigned long long u;
2031        } val;
2032        s16 field_width;
2033        bool is_sign;
2034
2035        while (*fmt) {
2036                /* skip any white space in format */
2037                /* white space in format matchs any amount of
2038                 * white space, including none, in the input.
2039                 */
2040                if (isspace(*fmt)) {
2041                        fmt = skip_spaces(++fmt);
2042                        str = skip_spaces(str);
2043                }
2044
2045                /* anything that is not a conversion must match exactly */
2046                if (*fmt != '%' && *fmt) {
2047                        if (*fmt++ != *str++)
2048                                break;
2049                        continue;
2050                }
2051
2052                if (!*fmt)
2053                        break;
2054                ++fmt;
2055
2056                /* skip this conversion.
2057                 * advance both strings to next white space
2058                 */
2059                if (*fmt == '*') {
2060                        if (!*str)
2061                                break;
2062                        while (!isspace(*fmt) && *fmt != '%' && *fmt)
2063                                fmt++;
2064                        while (!isspace(*str) && *str)
2065                                str++;
2066                        continue;
2067                }
2068
2069                /* get field width */
2070                field_width = -1;
2071                if (isdigit(*fmt)) {
2072                        field_width = skip_atoi(&fmt);
2073                        if (field_width <= 0)
2074                                break;
2075                }
2076
2077                /* get conversion qualifier */
2078                qualifier = -1;
2079                if (*fmt == 'h' || _tolower(*fmt) == 'l' ||
2080                    _tolower(*fmt) == 'z') {
2081                        qualifier = *fmt++;
2082                        if (unlikely(qualifier == *fmt)) {
2083                                if (qualifier == 'h') {
2084                                        qualifier = 'H';
2085                                        fmt++;
2086                                } else if (qualifier == 'l') {
2087                                        qualifier = 'L';
2088                                        fmt++;
2089                                }
2090                        }
2091                }
2092
2093                if (!*fmt)
2094                        break;
2095
2096                if (*fmt == 'n') {
2097                        /* return number of characters read so far */
2098                        *va_arg(args, int *) = str - buf;
2099                        ++fmt;
2100                        continue;
2101                }
2102
2103                if (!*str)
2104                        break;
2105
2106                base = 10;
2107                is_sign = 0;
2108
2109                switch (*fmt++) {
2110                case 'c':
2111                {
2112                        char *s = (char *)va_arg(args, char*);
2113                        if (field_width == -1)
2114                                field_width = 1;
2115                        do {
2116                                *s++ = *str++;
2117                        } while (--field_width > 0 && *str);
2118                        num++;
2119                }
2120                continue;
2121                case 's':
2122                {
2123                        char *s = (char *)va_arg(args, char *);
2124                        if (field_width == -1)
2125                                field_width = SHRT_MAX;
2126                        /* first, skip leading white space in buffer */
2127                        str = skip_spaces(str);
2128
2129                        /* now copy until next white space */
2130                        while (*str && !isspace(*str) && field_width--)
2131                                *s++ = *str++;
2132                        *s = '\0';
2133                        num++;
2134                }
2135                continue;
2136                case 'o':
2137                        base = 8;
2138                        break;
2139                case 'x':
2140                case 'X':
2141                        base = 16;
2142                        break;
2143                case 'i':
2144                        base = 0;
2145                case 'd':
2146                        is_sign = 1;
2147                case 'u':
2148                        break;
2149                case '%':
2150                        /* looking for '%' in str */
2151                        if (*str++ != '%')
2152                                return num;
2153                        continue;
2154                default:
2155                        /* invalid format; stop here */
2156                        return num;
2157                }
2158
2159                /* have some sort of integer conversion.
2160                 * first, skip white space in buffer.
2161                 */
2162                str = skip_spaces(str);
2163
2164                digit = *str;
2165                if (is_sign && digit == '-')
2166                        digit = *(str + 1);
2167
2168                if (!digit
2169                    || (base == 16 && !isxdigit(digit))
2170                    || (base == 10 && !isdigit(digit))
2171                    || (base == 8 && (!isdigit(digit) || digit > '7'))
2172                    || (base == 0 && !isdigit(digit)))
2173                        break;
2174
2175                if (is_sign)
2176                        val.s = qualifier != 'L' ?
2177                                simple_strtol(str, &next, base) :
2178                                simple_strtoll(str, &next, base);
2179                else
2180                        val.u = qualifier != 'L' ?
2181                                simple_strtoul(str, &next, base) :
2182                                simple_strtoull(str, &next, base);
2183
2184                if (field_width > 0 && next - str > field_width) {
2185                        if (base == 0)
2186                                _parse_integer_fixup_radix(str, &base);
2187                        while (next - str > field_width) {
2188                                if (is_sign)
2189                                        val.s = div_s64(val.s, base);
2190                                else
2191                                        val.u = div_u64(val.u, base);
2192                                --next;
2193                        }
2194                }
2195
2196                switch (qualifier) {
2197                case 'H':       /* that's 'hh' in format */
2198                        if (is_sign)
2199                                *va_arg(args, signed char *) = val.s;
2200                        else
2201                                *va_arg(args, unsigned char *) = val.u;
2202                        break;
2203                case 'h':
2204                        if (is_sign)
2205                                *va_arg(args, short *) = val.s;
2206                        else
2207                                *va_arg(args, unsigned short *) = val.u;
2208                        break;
2209                case 'l':
2210                        if (is_sign)
2211                                *va_arg(args, long *) = val.s;
2212                        else
2213                                *va_arg(args, unsigned long *) = val.u;
2214                        break;
2215                case 'L':
2216                        if (is_sign)
2217                                *va_arg(args, long long *) = val.s;
2218                        else
2219                                *va_arg(args, unsigned long long *) = val.u;
2220                        break;
2221                case 'Z':
2222                case 'z':
2223                        *va_arg(args, size_t *) = val.u;
2224                        break;
2225                default:
2226                        if (is_sign)
2227                                *va_arg(args, int *) = val.s;
2228                        else
2229                                *va_arg(args, unsigned int *) = val.u;
2230                        break;
2231                }
2232                num++;
2233
2234                if (!next)
2235                        break;
2236                str = next;
2237        }
2238
2239        return num;
2240}
2241EXPORT_SYMBOL(vsscanf);
2242
2243/**
2244 * sscanf - Unformat a buffer into a list of arguments
2245 * @buf:        input buffer
2246 * @fmt:        formatting of buffer
2247 * @...:        resulting arguments
2248 */
2249int sscanf(const char *buf, const char *fmt, ...)
2250{
2251        va_list args;
2252        int i;
2253
2254        va_start(args, fmt);
2255        i = vsscanf(buf, fmt, args);
2256        va_end(args);
2257
2258        return i;
2259}
2260EXPORT_SYMBOL(sscanf);
2261
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