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  42 * This function is obsolete.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  67 * This function is obsolete.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, const char *fmt)
 538{
 539        unsigned long value;
 540#ifdef CONFIG_KALLSYMS
 541        char sym[KSYM_SYMBOL_LEN];
 542#endif
 543
 544        if (fmt[1] == 'R')
 545                ptr = __builtin_extract_return_addr(ptr);
 546        value = (unsigned long)ptr;
 547
 548#ifdef CONFIG_KALLSYMS
 549        if (*fmt == 'B')
 550                sprint_backtrace(sym, value);
 551        else if (*fmt != 'f' && *fmt != 's')
 552                sprint_symbol(sym, value);
 553        else
 554                sprint_symbol_no_offset(sym, value);
 555
 556        return string(buf, end, sym, spec);
 557#else
 558        spec.field_width = 2 * sizeof(void *);
 559        spec.flags |= SPECIAL | SMALL | ZEROPAD;
 560        spec.base = 16;
 561
 562        return number(buf, end, value, spec);
 563#endif
 564}
 565
 566static noinline_for_stack
 567char *resource_string(char *buf, char *end, struct resource *res,
 568                      struct printf_spec spec, const char *fmt)
 569{
 570#ifndef IO_RSRC_PRINTK_SIZE
 571#define IO_RSRC_PRINTK_SIZE     6
 572#endif
 573
 574#ifndef MEM_RSRC_PRINTK_SIZE
 575#define MEM_RSRC_PRINTK_SIZE    10
 576#endif
 577        static const struct printf_spec io_spec = {
 578                .base = 16,
 579                .field_width = IO_RSRC_PRINTK_SIZE,
 580                .precision = -1,
 581                .flags = SPECIAL | SMALL | ZEROPAD,
 582        };
 583        static const struct printf_spec mem_spec = {
 584                .base = 16,
 585                .field_width = MEM_RSRC_PRINTK_SIZE,
 586                .precision = -1,
 587                .flags = SPECIAL | SMALL | ZEROPAD,
 588        };
 589        static const struct printf_spec bus_spec = {
 590                .base = 16,
 591                .field_width = 2,
 592                .precision = -1,
 593                .flags = SMALL | ZEROPAD,
 594        };
 595        static const struct printf_spec dec_spec = {
 596                .base = 10,
 597                .precision = -1,
 598                .flags = 0,
 599        };
 600        static const struct printf_spec str_spec = {
 601                .field_width = -1,
 602                .precision = 10,
 603                .flags = LEFT,
 604        };
 605        static const struct printf_spec flag_spec = {
 606                .base = 16,
 607                .precision = -1,
 608                .flags = SPECIAL | SMALL,
 609        };
 610
 611        /* 32-bit res (sizeof==4): 10 chars in dec, 10 in hex ("0x" + 8)
 612         * 64-bit res (sizeof==8): 20 chars in dec, 18 in hex ("0x" + 16) */
 613#define RSRC_BUF_SIZE           ((2 * sizeof(resource_size_t)) + 4)
 614#define FLAG_BUF_SIZE           (2 * sizeof(res->flags))
 615#define DECODED_BUF_SIZE        sizeof("[mem - 64bit pref window disabled]")
 616#define RAW_BUF_SIZE            sizeof("[mem - flags 0x]")
 617        char sym[max(2*RSRC_BUF_SIZE + DECODED_BUF_SIZE,
 618                     2*RSRC_BUF_SIZE + FLAG_BUF_SIZE + RAW_BUF_SIZE)];
 619
 620        char *p = sym, *pend = sym + sizeof(sym);
 621        int decode = (fmt[0] == 'R') ? 1 : 0;
 622        const struct printf_spec *specp;
 623
 624        *p++ = '[';
 625        if (res->flags & IORESOURCE_IO) {
 626                p = string(p, pend, "io  ", str_spec);
 627                specp = &io_spec;
 628        } else if (res->flags & IORESOURCE_MEM) {
 629                p = string(p, pend, "mem ", str_spec);
 630                specp = &mem_spec;
 631        } else if (res->flags & IORESOURCE_IRQ) {
 632                p = string(p, pend, "irq ", str_spec);
 633                specp = &dec_spec;
 634        } else if (res->flags & IORESOURCE_DMA) {
 635                p = string(p, pend, "dma ", str_spec);
 636                specp = &dec_spec;
 637        } else if (res->flags & IORESOURCE_BUS) {
 638                p = string(p, pend, "bus ", str_spec);
 639                specp = &bus_spec;
 640        } else {
 641                p = string(p, pend, "??? ", str_spec);
 642                specp = &mem_spec;
 643                decode = 0;
 644        }
 645        p = number(p, pend, res->start, *specp);
 646        if (res->start != res->end) {
 647                *p++ = '-';
 648                p = number(p, pend, res->end, *specp);
 649        }
 650        if (decode) {
 651                if (res->flags & IORESOURCE_MEM_64)
 652                        p = string(p, pend, " 64bit", str_spec);
 653                if (res->flags & IORESOURCE_PREFETCH)
 654                        p = string(p, pend, " pref", str_spec);
 655                if (res->flags & IORESOURCE_WINDOW)
 656                        p = string(p, pend, " window", str_spec);
 657                if (res->flags & IORESOURCE_DISABLED)
 658                        p = string(p, pend, " disabled", str_spec);
 659        } else {
 660                p = string(p, pend, " flags ", str_spec);
 661                p = number(p, pend, res->flags, flag_spec);
 662        }
 663        *p++ = ']';
 664        *p = '\0';
 665
 666        return string(buf, end, sym, spec);
 667}
 668
 669static noinline_for_stack
 670char *hex_string(char *buf, char *end, u8 *addr, struct printf_spec spec,
 671                 const char *fmt)
 672{
 673        int i, len = 1;         /* if we pass '%ph[CDN]', field witdh remains
 674                                   negative value, fallback to the default */
 675        char separator;
 676
 677        if (spec.field_width == 0)
 678                /* nothing to print */
 679                return buf;
 680
 681        if (ZERO_OR_NULL_PTR(addr))
 682                /* NULL pointer */
 683                return string(buf, end, NULL, spec);
 684
 685        switch (fmt[1]) {
 686        case 'C':
 687                separator = ':';
 688                break;
 689        case 'D':
 690                separator = '-';
 691                break;
 692        case 'N':
 693                separator = 0;
 694                break;
 695        default:
 696                separator = ' ';
 697                break;
 698        }
 699
 700        if (spec.field_width > 0)
 701                len = min_t(int, spec.field_width, 64);
 702
 703        for (i = 0; i < len && buf < end - 1; i++) {
 704                buf = hex_byte_pack(buf, addr[i]);
 705
 706                if (buf < end && separator && i != len - 1)
 707                        *buf++ = separator;
 708        }
 709
 710        return buf;
 711}
 712
 713static noinline_for_stack
 714char *mac_address_string(char *buf, char *end, u8 *addr,
 715                         struct printf_spec spec, const char *fmt)
 716{
 717        char mac_addr[sizeof("xx:xx:xx:xx:xx:xx")];
 718        char *p = mac_addr;
 719        int i;
 720        char separator;
 721        bool reversed = false;
 722
 723        switch (fmt[1]) {
 724        case 'F':
 725                separator = '-';
 726                break;
 727
 728        case 'R':
 729                reversed = true;
 730                /* fall through */
 731
 732        default:
 733                separator = ':';
 734                break;
 735        }
 736
 737        for (i = 0; i < 6; i++) {
 738                if (reversed)
 739                        p = hex_byte_pack(p, addr[5 - i]);
 740                else
 741                        p = hex_byte_pack(p, addr[i]);
 742
 743                if (fmt[0] == 'M' && i != 5)
 744                        *p++ = separator;
 745        }
 746        *p = '\0';
 747
 748        return string(buf, end, mac_addr, spec);
 749}
 750
 751static noinline_for_stack
 752char *ip4_string(char *p, const u8 *addr, const char *fmt)
 753{
 754        int i;
 755        bool leading_zeros = (fmt[0] == 'i');
 756        int index;
 757        int step;
 758
 759        switch (fmt[2]) {
 760        case 'h':
 761#ifdef __BIG_ENDIAN
 762                index = 0;
 763                step = 1;
 764#else
 765                index = 3;
 766                step = -1;
 767#endif
 768                break;
 769        case 'l':
 770                index = 3;
 771                step = -1;
 772                break;
 773        case 'n':
 774        case 'b':
 775        default:
 776                index = 0;
 777                step = 1;
 778                break;
 779        }
 780        for (i = 0; i < 4; i++) {
 781                char temp[3];   /* hold each IP quad in reverse order */
 782                int digits = put_dec_trunc8(temp, addr[index]) - temp;
 783                if (leading_zeros) {
 784                        if (digits < 3)
 785                                *p++ = '0';
 786                        if (digits < 2)
 787                                *p++ = '0';
 788                }
 789                /* reverse the digits in the quad */
 790                while (digits--)
 791                        *p++ = temp[digits];
 792                if (i < 3)
 793                        *p++ = '.';
 794                index += step;
 795        }
 796        *p = '\0';
 797
 798        return p;
 799}
 800
 801static noinline_for_stack
 802char *ip6_compressed_string(char *p, const char *addr)
 803{
 804        int i, j, range;
 805        unsigned char zerolength[8];
 806        int longest = 1;
 807        int colonpos = -1;
 808        u16 word;
 809        u8 hi, lo;
 810        bool needcolon = false;
 811        bool useIPv4;
 812        struct in6_addr in6;
 813
 814        memcpy(&in6, addr, sizeof(struct in6_addr));
 815
 816        useIPv4 = ipv6_addr_v4mapped(&in6) || ipv6_addr_is_isatap(&in6);
 817
 818        memset(zerolength, 0, sizeof(zerolength));
 819
 820        if (useIPv4)
 821                range = 6;
 822        else
 823                range = 8;
 824
 825        /* find position of longest 0 run */
 826        for (i = 0; i < range; i++) {
 827                for (j = i; j < range; j++) {
 828                        if (in6.s6_addr16[j] != 0)
 829                                break;
 830                        zerolength[i]++;
 831                }
 832        }
 833        for (i = 0; i < range; i++) {
 834                if (zerolength[i] > longest) {
 835                        longest = zerolength[i];
 836                        colonpos = i;
 837                }
 838        }
 839        if (longest == 1)               /* don't compress a single 0 */
 840                colonpos = -1;
 841
 842        /* emit address */
 843        for (i = 0; i < range; i++) {
 844                if (i == colonpos) {
 845                        if (needcolon || i == 0)
 846                                *p++ = ':';
 847                        *p++ = ':';
 848                        needcolon = false;
 849                        i += longest - 1;
 850                        continue;
 851                }
 852                if (needcolon) {
 853                        *p++ = ':';
 854                        needcolon = false;
 855                }
 856                /* hex u16 without leading 0s */
 857                word = ntohs(in6.s6_addr16[i]);
 858                hi = word >> 8;
 859                lo = word & 0xff;
 860                if (hi) {
 861                        if (hi > 0x0f)
 862                                p = hex_byte_pack(p, hi);
 863                        else
 864                                *p++ = hex_asc_lo(hi);
 865                        p = hex_byte_pack(p, lo);
 866                }
 867                else if (lo > 0x0f)
 868                        p = hex_byte_pack(p, lo);
 869                else
 870                        *p++ = hex_asc_lo(lo);
 871                needcolon = true;
 872        }
 873
 874        if (useIPv4) {
 875                if (needcolon)
 876                        *p++ = ':';
 877                p = ip4_string(p, &in6.s6_addr[12], "I4");
 878        }
 879        *p = '\0';
 880
 881        return p;
 882}
 883
 884static noinline_for_stack
 885char *ip6_string(char *p, const char *addr, const char *fmt)
 886{
 887        int i;
 888
 889        for (i = 0; i < 8; i++) {
 890                p = hex_byte_pack(p, *addr++);
 891                p = hex_byte_pack(p, *addr++);
 892                if (fmt[0] == 'I' && i != 7)
 893                        *p++ = ':';
 894        }
 895        *p = '\0';
 896
 897        return p;
 898}
 899
 900static noinline_for_stack
 901char *ip6_addr_string(char *buf, char *end, const u8 *addr,
 902                      struct printf_spec spec, const char *fmt)
 903{
 904        char ip6_addr[sizeof("xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255")];
 905
 906        if (fmt[0] == 'I' && fmt[2] == 'c')
 907                ip6_compressed_string(ip6_addr, addr);
 908        else
 909                ip6_string(ip6_addr, addr, fmt);
 910
 911        return string(buf, end, ip6_addr, spec);
 912}
 913
 914static noinline_for_stack
 915char *ip4_addr_string(char *buf, char *end, const u8 *addr,
 916                      struct printf_spec spec, const char *fmt)
 917{
 918        char ip4_addr[sizeof("255.255.255.255")];
 919
 920        ip4_string(ip4_addr, addr, fmt);
 921
 922        return string(buf, end, ip4_addr, spec);
 923}
 924
 925static noinline_for_stack
 926char *uuid_string(char *buf, char *end, const u8 *addr,
 927                  struct printf_spec spec, const char *fmt)
 928{
 929        char uuid[sizeof("xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx")];
 930        char *p = uuid;
 931        int i;
 932        static const u8 be[16] = {0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15};
 933        static const u8 le[16] = {3,2,1,0,5,4,7,6,8,9,10,11,12,13,14,15};
 934        const u8 *index = be;
 935        bool uc = false;
 936
 937        switch (*(++fmt)) {
 938        case 'L':
 939                uc = true;              /* fall-through */
 940        case 'l':
 941                index = le;
 942                break;
 943        case 'B':
 944                uc = true;
 945                break;
 946        }
 947
 948        for (i = 0; i < 16; i++) {
 949                p = hex_byte_pack(p, addr[index[i]]);
 950                switch (i) {
 951                case 3:
 952                case 5:
 953                case 7:
 954                case 9:
 955                        *p++ = '-';
 956                        break;
 957                }
 958        }
 959
 960        *p = 0;
 961
 962        if (uc) {
 963                p = uuid;
 964                do {
 965                        *p = toupper(*p);
 966                } while (*(++p));
 967        }
 968
 969        return string(buf, end, uuid, spec);
 970}
 971
 972static
 973char *netdev_feature_string(char *buf, char *end, const u8 *addr,
 974                      struct printf_spec spec)
 975{
 976        spec.flags |= SPECIAL | SMALL | ZEROPAD;
 977        if (spec.field_width == -1)
 978                spec.field_width = 2 + 2 * sizeof(netdev_features_t);
 979        spec.base = 16;
 980
 981        return number(buf, end, *(const netdev_features_t *)addr, spec);
 982}
 983
 984int kptr_restrict __read_mostly;
 985
 986/*
 987 * Show a '%p' thing.  A kernel extension is that the '%p' is followed
 988 * by an extra set of alphanumeric characters that are extended format
 989 * specifiers.
 990 *
 991 * Right now we handle:
 992 *
 993 * - 'F' For symbolic function descriptor pointers with offset
 994 * - 'f' For simple symbolic function names without offset
 995 * - 'S' For symbolic direct pointers with offset
 996 * - 's' For symbolic direct pointers without offset
 997 * - '[FfSs]R' as above with __builtin_extract_return_addr() translation
 998 * - 'B' For backtraced symbolic direct pointers with offset
 999 * - 'R' For decoded struct resource, e.g., [mem 0x0-0x1f 64bit pref]
1000 * - 'r' For raw struct resource, e.g., [mem 0x0-0x1f flags 0x201]
1001 * - 'M' For a 6-byte MAC address, it prints the address in the
1002 *       usual colon-separated hex notation
1003 * - 'm' For a 6-byte MAC address, it prints the hex address without colons
1004 * - 'MF' For a 6-byte MAC FDDI address, it prints the address
1005 *       with a dash-separated hex notation
1006 * - '[mM]R' For a 6-byte MAC address, Reverse order (Bluetooth)
1007 * - 'I' [46] for IPv4/IPv6 addresses printed in the usual way
1008 *       IPv4 uses dot-separated decimal without leading 0's (1.2.3.4)
1009 *       IPv6 uses colon separated network-order 16 bit hex with leading 0's
1010 * - 'i' [46] for 'raw' IPv4/IPv6 addresses
1011 *       IPv6 omits the colons (01020304...0f)
1012 *       IPv4 uses dot-separated decimal with leading 0's (010.123.045.006)
1013 * - '[Ii]4[hnbl]' IPv4 addresses in host, network, big or little endian order
1014 * - 'I6c' for IPv6 addresses printed as specified by
1015 *       http://tools.ietf.org/html/rfc5952
1016 * - 'U' For a 16 byte UUID/GUID, it prints the UUID/GUID in the form
1017 *       "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx"
1018 *       Options for %pU are:
1019 *         b big endian lower case hex (default)
1020 *         B big endian UPPER case hex
1021 *         l little endian lower case hex
1022 *         L little endian UPPER case hex
1023 *           big endian output byte order is:
1024 *             [0][1][2][3]-[4][5]-[6][7]-[8][9]-[10][11][12][13][14][15]
1025 *           little endian output byte order is:
1026 *             [3][2][1][0]-[5][4]-[7][6]-[8][9]-[10][11][12][13][14][15]
1027 * - 'V' For a struct va_format which contains a format string * and va_list *,
1028 *       call vsnprintf(->format, *->va_list).
1029 *       Implements a "recursive vsnprintf".
1030 *       Do not use this feature without some mechanism to verify the
1031 *       correctness of the format string and va_list arguments.
1032 * - 'K' For a kernel pointer that should be hidden from unprivileged users
1033 * - 'NF' For a netdev_features_t
1034 * - 'h[CDN]' For a variable-length buffer, it prints it as a hex string with
1035 *            a certain separator (' ' by default):
1036 *              C colon
1037 *              D dash
1038 *              N no separator
1039 *            The maximum supported length is 64 bytes of the input. Consider
1040 *            to use print_hex_dump() for the larger input.
1041 * - 'a' For a phys_addr_t type and its derivative types (passed by reference)
1042 *
1043 * Note: The difference between 'S' and 'F' is that on ia64 and ppc64
1044 * function pointers are really function descriptors, which contain a
1045 * pointer to the real address.
1046 */
1047static noinline_for_stack
1048char *pointer(const char *fmt, char *buf, char *end, void *ptr,
1049              struct printf_spec spec)
1050{
1051        int default_width = 2 * sizeof(void *) + (spec.flags & SPECIAL ? 2 : 0);
1052
1053        if (!ptr && *fmt != 'K') {
1054                /*
1055                 * Print (null) with the same width as a pointer so it makes
1056                 * tabular output look nice.
1057                 */
1058                if (spec.field_width == -1)
1059                        spec.field_width = default_width;
1060                return string(buf, end, "(null)", spec);
1061        }
1062
1063        switch (*fmt) {
1064        case 'F':
1065        case 'f':
1066                ptr = dereference_function_descriptor(ptr);
1067                /* Fallthrough */
1068        case 'S':
1069        case 's':
1070        case 'B':
1071                return symbol_string(buf, end, ptr, spec, fmt);
1072        case 'R':
1073        case 'r':
1074                return resource_string(buf, end, ptr, spec, fmt);
1075        case 'h':
1076                return hex_string(buf, end, ptr, spec, fmt);
1077        case 'M':                       /* Colon separated: 00:01:02:03:04:05 */
1078        case 'm':                       /* Contiguous: 000102030405 */
1079                                        /* [mM]F (FDDI) */
1080                                        /* [mM]R (Reverse order; Bluetooth) */
1081                return mac_address_string(buf, end, ptr, spec, fmt);
1082        case 'I':                       /* Formatted IP supported
1083                                         * 4:   1.2.3.4
1084                                         * 6:   0001:0203:...:0708
1085                                         * 6c:  1::708 or 1::1.2.3.4
1086                                         */
1087        case 'i':                       /* Contiguous:
1088                                         * 4:   001.002.003.004
1089                                         * 6:   000102...0f
1090                                         */
1091                switch (fmt[1]) {
1092                case '6':
1093                        return ip6_addr_string(buf, end, ptr, spec, fmt);
1094                case '4':
1095                        return ip4_addr_string(buf, end, ptr, spec, fmt);
1096                }
1097                break;
1098        case 'U':
1099                return uuid_string(buf, end, ptr, spec, fmt);
1100        case 'V':
1101                {
1102                        va_list va;
1103
1104                        va_copy(va, *((struct va_format *)ptr)->va);
1105                        buf += vsnprintf(buf, end > buf ? end - buf : 0,
1106                                         ((struct va_format *)ptr)->fmt, va);
1107                        va_end(va);
1108                        return buf;
1109                }
1110        case 'K':
1111                /*
1112                 * %pK cannot be used in IRQ context because its test
1113                 * for CAP_SYSLOG would be meaningless.
1114                 */
1115                if (kptr_restrict && (in_irq() || in_serving_softirq() ||
1116                                      in_nmi())) {
1117                        if (spec.field_width == -1)
1118                                spec.field_width = default_width;
1119                        return string(buf, end, "pK-error", spec);
1120                }
1121                if (!((kptr_restrict == 0) ||
1122                      (kptr_restrict == 1 &&
1123                       has_capability_noaudit(current, CAP_SYSLOG))))
1124                        ptr = NULL;
1125                break;
1126        case 'N':
1127                switch (fmt[1]) {
1128                case 'F':
1129                        return netdev_feature_string(buf, end, ptr, spec);
1130                }
1131                break;
1132        case 'a':
1133                spec.flags |= SPECIAL | SMALL | ZEROPAD;
1134                spec.field_width = sizeof(phys_addr_t) * 2 + 2;
1135                spec.base = 16;
1136                return number(buf, end,
1137                              (unsigned long long) *((phys_addr_t *)ptr), spec);
1138        }
1139        spec.flags |= SMALL;
1140        if (spec.field_width == -1) {
1141                spec.field_width = default_width;
1142                spec.flags |= ZEROPAD;
1143        }
1144        spec.base = 16;
1145
1146        return number(buf, end, (unsigned long) ptr, spec);
1147}
1148
1149/*
1150 * Helper function to decode printf style format.
1151 * Each call decode a token from the format and return the
1152 * number of characters read (or likely the delta where it wants
1153 * to go on the next call).
1154 * The decoded token is returned through the parameters
1155 *
1156 * 'h', 'l', or 'L' for integer fields
1157 * 'z' support added 23/7/1999 S.H.
1158 * 'z' changed to 'Z' --davidm 1/25/99
1159 * 't' added for ptrdiff_t
1160 *
1161 * @fmt: the format string
1162 * @type of the token returned
1163 * @flags: various flags such as +, -, # tokens..
1164 * @field_width: overwritten width
1165 * @base: base of the number (octal, hex, ...)
1166 * @precision: precision of a number
1167 * @qualifier: qualifier of a number (long, size_t, ...)
1168 */
1169static noinline_for_stack
1170int format_decode(const char *fmt, struct printf_spec *spec)
1171{
1172        const char *start = fmt;
1173
1174        /* we finished early by reading the field width */
1175        if (spec->type == FORMAT_TYPE_WIDTH) {
1176                if (spec->field_width < 0) {
1177                        spec->field_width = -spec->field_width;
1178                        spec->flags |= LEFT;
1179                }
1180                spec->type = FORMAT_TYPE_NONE;
1181                goto precision;
1182        }
1183
1184        /* we finished early by reading the precision */
1185        if (spec->type == FORMAT_TYPE_PRECISION) {
1186                if (spec->precision < 0)
1187                        spec->precision = 0;
1188
1189                spec->type = FORMAT_TYPE_NONE;
1190                goto qualifier;
1191        }
1192
1193        /* By default */
1194        spec->type = FORMAT_TYPE_NONE;
1195
1196        for (; *fmt ; ++fmt) {
1197                if (*fmt == '%')
1198                        break;
1199        }
1200
1201        /* Return the current non-format string */
1202        if (fmt != start || !*fmt)
1203                return fmt - start;
1204
1205        /* Process flags */
1206        spec->flags = 0;
1207
1208        while (1) { /* this also skips first '%' */
1209                bool found = true;
1210
1211                ++fmt;
1212
1213                switch (*fmt) {
1214                case '-': spec->flags |= LEFT;    break;
1215                case '+': spec->flags |= PLUS;    break;
1216                case ' ': spec->flags |= SPACE;   break;
1217                case '#': spec->flags |= SPECIAL; break;
1218                case '0': spec->flags |= ZEROPAD; break;
1219                default:  found = false;
1220                }
1221
1222                if (!found)
1223                        break;
1224        }
1225
1226        /* get field width */
1227        spec->field_width = -1;
1228
1229        if (isdigit(*fmt))
1230                spec->field_width = skip_atoi(&fmt);
1231        else if (*fmt == '*') {
1232                /* it's the next argument */
1233                spec->type = FORMAT_TYPE_WIDTH;
1234                return ++fmt - start;
1235        }
1236
1237precision:
1238        /* get the precision */
1239        spec->precision = -1;
1240        if (*fmt == '.') {
1241                ++fmt;
1242                if (isdigit(*fmt)) {
1243                        spec->precision = skip_atoi(&fmt);
1244                        if (spec->precision < 0)
1245                                spec->precision = 0;
1246                } else if (*fmt == '*') {
1247                        /* it's the next argument */
1248                        spec->type = FORMAT_TYPE_PRECISION;
1249                        return ++fmt - start;
1250                }
1251        }
1252
1253qualifier:
1254        /* get the conversion qualifier */
1255        spec->qualifier = -1;
1256        if (*fmt == 'h' || _tolower(*fmt) == 'l' ||
1257            _tolower(*fmt) == 'z' || *fmt == 't') {
1258                spec->qualifier = *fmt++;
1259                if (unlikely(spec->qualifier == *fmt)) {
1260                        if (spec->qualifier == 'l') {
1261                                spec->qualifier = 'L';
1262                                ++fmt;
1263                        } else if (spec->qualifier == 'h') {
1264                                spec->qualifier = 'H';
1265                                ++fmt;
1266                        }
1267                }
1268        }
1269
1270        /* default base */
1271        spec->base = 10;
1272        switch (*fmt) {
1273        case 'c':
1274                spec->type = FORMAT_TYPE_CHAR;
1275                return ++fmt - start;
1276
1277        case 's':
1278                spec->type = FORMAT_TYPE_STR;
1279                return ++fmt - start;
1280
1281        case 'p':
1282                spec->type = FORMAT_TYPE_PTR;
1283                return fmt - start;
1284                /* skip alnum */
1285
1286        case 'n':
1287                spec->type = FORMAT_TYPE_NRCHARS;
1288                return ++fmt - start;
1289
1290        case '%':
1291                spec->type = FORMAT_TYPE_PERCENT_CHAR;
1292                return ++fmt - start;
1293
1294        /* integer number formats - set up the flags and "break" */
1295        case 'o':
1296                spec->base = 8;
1297                break;
1298
1299        case 'x':
1300                spec->flags |= SMALL;
1301
1302        case 'X':
1303                spec->base = 16;
1304                break;
1305
1306        case 'd':
1307        case 'i':
1308                spec->flags |= SIGN;
1309        case 'u':
1310                break;
1311
1312        default:
1313                spec->type = FORMAT_TYPE_INVALID;
1314                return fmt - start;
1315        }
1316
1317        if (spec->qualifier == 'L')
1318                spec->type = FORMAT_TYPE_LONG_LONG;
1319        else if (spec->qualifier == 'l') {
1320                if (spec->flags & SIGN)
1321                        spec->type = FORMAT_TYPE_LONG;
1322                else
1323                        spec->type = FORMAT_TYPE_ULONG;
1324        } else if (_tolower(spec->qualifier) == 'z') {
1325                spec->type = FORMAT_TYPE_SIZE_T;
1326        } else if (spec->qualifier == 't') {
1327                spec->type = FORMAT_TYPE_PTRDIFF;
1328        } else if (spec->qualifier == 'H') {
1329                if (spec->flags & SIGN)
1330                        spec->type = FORMAT_TYPE_BYTE;
1331                else
1332                        spec->type = FORMAT_TYPE_UBYTE;
1333        } else if (spec->qualifier == 'h') {
1334                if (spec->flags & SIGN)
1335                        spec->type = FORMAT_TYPE_SHORT;
1336                else
1337                        spec->type = FORMAT_TYPE_USHORT;
1338        } else {
1339                if (spec->flags & SIGN)
1340                        spec->type = FORMAT_TYPE_INT;
1341                else
1342                        spec->type = FORMAT_TYPE_UINT;
1343        }
1344
1345        return ++fmt - start;
1346}
1347
1348/**
1349 * vsnprintf - Format a string and place it in a buffer
1350 * @buf: The buffer to place the result into
1351 * @size: The size of the buffer, including the trailing null space
1352 * @fmt: The format string to use
1353 * @args: Arguments for the format string
1354 *
1355 * This function follows C99 vsnprintf, but has some extensions:
1356 * %pS output the name of a text symbol with offset
1357 * %ps output the name of a text symbol without offset
1358 * %pF output the name of a function pointer with its offset
1359 * %pf output the name of a function pointer without its offset
1360 * %pB output the name of a backtrace symbol with its offset
1361 * %pR output the address range in a struct resource with decoded flags
1362 * %pr output the address range in a struct resource with raw flags
1363 * %pM output a 6-byte MAC address with colons
1364 * %pMR output a 6-byte MAC address with colons in reversed order
1365 * %pMF output a 6-byte MAC address with dashes
1366 * %pm output a 6-byte MAC address without colons
1367 * %pmR output a 6-byte MAC address without colons in reversed order
1368 * %pI4 print an IPv4 address without leading zeros
1369 * %pi4 print an IPv4 address with leading zeros
1370 * %pI6 print an IPv6 address with colons
1371 * %pi6 print an IPv6 address without colons
1372 * %pI6c print an IPv6 address as specified by RFC 5952
1373 * %pU[bBlL] print a UUID/GUID in big or little endian using lower or upper
1374 *   case.
1375 * %*ph[CDN] a variable-length hex string with a separator (supports up to 64
1376 *           bytes of the input)
1377 * %n is ignored
1378 *
1379 * ** Please update Documentation/printk-formats.txt when making changes **
1380 *
1381 * The return value is the number of characters which would
1382 * be generated for the given input, excluding the trailing
1383 * '\0', as per ISO C99. If you want to have the exact
1384 * number of characters written into @buf as return value
1385 * (not including the trailing '\0'), use vscnprintf(). If the
1386 * return is greater than or equal to @size, the resulting
1387 * string is truncated.
1388 *
1389 * If you're not already dealing with a va_list consider using snprintf().
1390 */
1391int vsnprintf(char *buf, size_t size, const char *fmt, va_list args)
1392{
1393        unsigned long long num;
1394        char *str, *end;
1395        struct printf_spec spec = {0};
1396
1397        /* Reject out-of-range values early.  Large positive sizes are
1398           used for unknown buffer sizes. */
1399        if (WARN_ON_ONCE((int) size < 0))
1400                return 0;
1401
1402        str = buf;
1403        end = buf + size;
1404
1405        /* Make sure end is always >= buf */
1406        if (end < buf) {
1407                end = ((void *)-1);
1408                size = end - buf;
1409        }
1410
1411        while (*fmt) {
1412                const char *old_fmt = fmt;
1413                int read = format_decode(fmt, &spec);
1414
1415                fmt += read;
1416
1417                switch (spec.type) {
1418                case FORMAT_TYPE_NONE: {
1419                        int copy = read;
1420                        if (str < end) {
1421                                if (copy > end - str)
1422                                        copy = end - str;
1423                                memcpy(str, old_fmt, copy);
1424                        }
1425                        str += read;
1426                        break;
1427                }
1428
1429                case FORMAT_TYPE_WIDTH:
1430                        spec.field_width = va_arg(args, int);
1431                        break;
1432
1433                case FORMAT_TYPE_PRECISION:
1434                        spec.precision = va_arg(args, int);
1435                        break;
1436
1437                case FORMAT_TYPE_CHAR: {
1438                        char c;
1439
1440                        if (!(spec.flags & LEFT)) {
1441                                while (--spec.field_width > 0) {
1442                                        if (str < end)
1443                                                *str = ' ';
1444                                        ++str;
1445
1446                                }
1447                        }
1448                        c = (unsigned char) va_arg(args, int);
1449                        if (str < end)
1450                                *str = c;
1451                        ++str;
1452                        while (--spec.field_width > 0) {
1453                                if (str < end)
1454                                        *str = ' ';
1455                                ++str;
1456                        }
1457                        break;
1458                }
1459
1460                case FORMAT_TYPE_STR:
1461                        str = string(str, end, va_arg(args, char *), spec);
1462                        break;
1463
1464                case FORMAT_TYPE_PTR:
1465                        str = pointer(fmt+1, str, end, va_arg(args, void *),
1466                                      spec);
1467                        while (isalnum(*fmt))
1468                                fmt++;
1469                        break;
1470
1471                case FORMAT_TYPE_PERCENT_CHAR:
1472                        if (str < end)
1473                                *str = '%';
1474                        ++str;
1475                        break;
1476
1477                case FORMAT_TYPE_INVALID:
1478                        if (str < end)
1479                                *str = '%';
1480                        ++str;
1481                        break;
1482
1483                case FORMAT_TYPE_NRCHARS: {
1484                        u8 qualifier = spec.qualifier;
1485
1486                        if (qualifier == 'l') {
1487                                long *ip = va_arg(args, long *);
1488                                *ip = (str - buf);
1489                        } else if (_tolower(qualifier) == 'z') {
1490                                size_t *ip = va_arg(args, size_t *);
1491                                *ip = (str - buf);
1492                        } else {
1493                                int *ip = va_arg(args, int *);
1494                                *ip = (str - buf);
1495                        }
1496                        break;
1497                }
1498
1499                default:
1500                        switch (spec.type) {
1501                        case FORMAT_TYPE_LONG_LONG:
1502                                num = va_arg(args, long long);
1503                                break;
1504                        case FORMAT_TYPE_ULONG:
1505                                num = va_arg(args, unsigned long);
1506                                break;
1507                        case FORMAT_TYPE_LONG:
1508                                num = va_arg(args, long);
1509                                break;
1510                        case FORMAT_TYPE_SIZE_T:
1511                                if (spec.flags & SIGN)
1512                                        num = va_arg(args, ssize_t);
1513                                else
1514                                        num = va_arg(args, size_t);
1515                                break;
1516                        case FORMAT_TYPE_PTRDIFF:
1517                                num = va_arg(args, ptrdiff_t);
1518                                break;
1519                        case FORMAT_TYPE_UBYTE:
1520                                num = (unsigned char) va_arg(args, int);
1521                                break;
1522                        case FORMAT_TYPE_BYTE:
1523                                num = (signed char) va_arg(args, int);
1524                                break;
1525                        case FORMAT_TYPE_USHORT:
1526                                num = (unsigned short) va_arg(args, int);
1527                                break;
1528                        case FORMAT_TYPE_SHORT:
1529                                num = (short) va_arg(args, int);
1530                                break;
1531                        case FORMAT_TYPE_INT:
1532                                num = (int) va_arg(args, int);
1533                                break;
1534                        default:
1535                                num = va_arg(args, unsigned int);
1536                        }
1537
1538                        str = number(str, end, num, spec);
1539                }
1540        }
1541
1542        if (size > 0) {
1543                if (str < end)
1544                        *str = '\0';
1545                else
1546                        end[-1] = '\0';
1547        }
1548
1549        /* the trailing null byte doesn't count towards the total */
1550        return str-buf;
1551
1552}
1553EXPORT_SYMBOL(vsnprintf);
1554
1555/**
1556 * vscnprintf - Format a string and place it in a buffer
1557 * @buf: The buffer to place the result into
1558 * @size: The size of the buffer, including the trailing null space
1559 * @fmt: The format string to use
1560 * @args: Arguments for the format string
1561 *
1562 * The return value is the number of characters which have been written into
1563 * the @buf not including the trailing '\0'. If @size is == 0 the function
1564 * returns 0.
1565 *
1566 * If you're not already dealing with a va_list consider using scnprintf().
1567 *
1568 * See the vsnprintf() documentation for format string extensions over C99.
1569 */
1570int vscnprintf(char *buf, size_t size, const char *fmt, va_list args)
1571{
1572        int i;
1573
1574        i = vsnprintf(buf, size, fmt, args);
1575
1576        if (likely(i < size))
1577                return i;
1578        if (size != 0)
1579                return size - 1;
1580        return 0;
1581}
1582EXPORT_SYMBOL(vscnprintf);
1583
1584/**
1585 * snprintf - Format a string and place it in a buffer
1586 * @buf: The buffer to place the result into
1587 * @size: The size of the buffer, including the trailing null space
1588 * @fmt: The format string to use
1589 * @...: Arguments for the format string
1590 *
1591 * The return value is the number of characters which would be
1592 * generated for the given input, excluding the trailing null,
1593 * as per ISO C99.  If the return is greater than or equal to
1594 * @size, the resulting string is truncated.
1595 *
1596 * See the vsnprintf() documentation for format string extensions over C99.
1597 */
1598int snprintf(char *buf, size_t size, const char *fmt, ...)
1599{
1600        va_list args;
1601        int i;
1602
1603        va_start(args, fmt);
1604        i = vsnprintf(buf, size, fmt, args);
1605        va_end(args);
1606
1607        return i;
1608}
1609EXPORT_SYMBOL(snprintf);
1610
1611/**
1612 * scnprintf - Format a string and place it in a buffer
1613 * @buf: The buffer to place the result into
1614 * @size: The size of the buffer, including the trailing null space
1615 * @fmt: The format string to use
1616 * @...: Arguments for the format string
1617 *
1618 * The return value is the number of characters written into @buf not including
1619 * the trailing '\0'. If @size is == 0 the function returns 0.
1620 */
1621
1622int scnprintf(char *buf, size_t size, const char *fmt, ...)
1623{
1624        va_list args;
1625        int i;
1626
1627        va_start(args, fmt);
1628        i = vscnprintf(buf, size, fmt, args);
1629        va_end(args);
1630
1631        return i;
1632}
1633EXPORT_SYMBOL(scnprintf);
1634
1635/**
1636 * vsprintf - Format a string and place it in a buffer
1637 * @buf: The buffer to place the result into
1638 * @fmt: The format string to use
1639 * @args: Arguments for the format string
1640 *
1641 * The function returns the number of characters written
1642 * into @buf. Use vsnprintf() or vscnprintf() in order to avoid
1643 * buffer overflows.
1644 *
1645 * If you're not already dealing with a va_list consider using sprintf().
1646 *
1647 * See the vsnprintf() documentation for format string extensions over C99.
1648 */
1649int vsprintf(char *buf, const char *fmt, va_list args)
1650{
1651        return vsnprintf(buf, INT_MAX, fmt, args);
1652}
1653EXPORT_SYMBOL(vsprintf);
1654
1655/**
1656 * sprintf - Format a string and place it in a buffer
1657 * @buf: The buffer to place the result into
1658 * @fmt: The format string to use
1659 * @...: Arguments for the format string
1660 *
1661 * The function returns the number of characters written
1662 * into @buf. Use snprintf() or scnprintf() in order to avoid
1663 * buffer overflows.
1664 *
1665 * See the vsnprintf() documentation for format string extensions over C99.
1666 */
1667int sprintf(char *buf, const char *fmt, ...)
1668{
1669        va_list args;
1670        int i;
1671
1672        va_start(args, fmt);
1673        i = vsnprintf(buf, INT_MAX, fmt, args);
1674        va_end(args);
1675
1676        return i;
1677}
1678EXPORT_SYMBOL(sprintf);
1679
1680#ifdef CONFIG_BINARY_PRINTF
1681/*
1682 * bprintf service:
1683 * vbin_printf() - VA arguments to binary data
1684 * bstr_printf() - Binary data to text string
1685 */
1686
1687/**
1688 * vbin_printf - Parse a format string and place args' binary value in a buffer
1689 * @bin_buf: The buffer to place args' binary value
1690 * @size: The size of the buffer(by words(32bits), not characters)
1691 * @fmt: The format string to use
1692 * @args: Arguments for the format string
1693 *
1694 * The format follows C99 vsnprintf, except %n is ignored, and its argument
1695 * is skiped.
1696 *
1697 * The return value is the number of words(32bits) which would be generated for
1698 * the given input.
1699 *
1700 * NOTE:
1701 * If the return value is greater than @size, the resulting bin_buf is NOT
1702 * valid for bstr_printf().
1703 */
1704int vbin_printf(u32 *bin_buf, size_t size, const char *fmt, va_list args)
1705{
1706        struct printf_spec spec = {0};
1707        char *str, *end;
1708
1709        str = (char *)bin_buf;
1710        end = (char *)(bin_buf + size);
1711
1712#define save_arg(type)                                                  \
1713do {                                                                    \
1714        if (sizeof(type) == 8) {                                        \
1715                unsigned long long value;                               \
1716                str = PTR_ALIGN(str, sizeof(u32));                      \
1717                value = va_arg(args, unsigned long long);               \
1718                if (str + sizeof(type) <= end) {                        \
1719                        *(u32 *)str = *(u32 *)&value;                   \
1720                        *(u32 *)(str + 4) = *((u32 *)&value + 1);       \
1721                }                                                       \
1722        } else {                                                        \
1723                unsigned long value;                                    \
1724                str = PTR_ALIGN(str, sizeof(type));                     \
1725                value = va_arg(args, int);                              \
1726                if (str + sizeof(type) <= end)                          \
1727                        *(typeof(type) *)str = (type)value;             \
1728        }                                                               \
1729        str += sizeof(type);                                            \
1730} while (0)
1731
1732        while (*fmt) {
1733                int read = format_decode(fmt, &spec);
1734
1735                fmt += read;
1736
1737                switch (spec.type) {
1738                case FORMAT_TYPE_NONE:
1739                case FORMAT_TYPE_INVALID:
1740                case FORMAT_TYPE_PERCENT_CHAR:
1741                        break;
1742
1743                case FORMAT_TYPE_WIDTH:
1744                case FORMAT_TYPE_PRECISION:
1745                        save_arg(int);
1746                        break;
1747
1748                case FORMAT_TYPE_CHAR:
1749                        save_arg(char);
1750                        break;
1751
1752                case FORMAT_TYPE_STR: {
1753                        const char *save_str = va_arg(args, char *);
1754                        size_t len;
1755
1756                        if ((unsigned long)save_str > (unsigned long)-PAGE_SIZE
1757                                        || (unsigned long)save_str < PAGE_SIZE)
1758                                save_str = "(null)";
1759                        len = strlen(save_str) + 1;
1760                        if (str + len < end)
1761                                memcpy(str, save_str, len);
1762                        str += len;
1763                        break;
1764                }
1765
1766                case FORMAT_TYPE_PTR:
1767                        save_arg(void *);
1768                        /* skip all alphanumeric pointer suffixes */
1769                        while (isalnum(*fmt))
1770                                fmt++;
1771                        break;
1772
1773                case FORMAT_TYPE_NRCHARS: {
1774                        /* skip %n 's argument */
1775                        u8 qualifier = spec.qualifier;
1776                        void *skip_arg;
1777                        if (qualifier == 'l')
1778                                skip_arg = va_arg(args, long *);
1779                        else if (_tolower(qualifier) == 'z')
1780                                skip_arg = va_arg(args, size_t *);
1781                        else
1782                                skip_arg = va_arg(args, int *);
1783                        break;
1784                }
1785
1786                default:
1787                        switch (spec.type) {
1788
1789                        case FORMAT_TYPE_LONG_LONG:
1790                                save_arg(long long);
1791                                break;
1792                        case FORMAT_TYPE_ULONG:
1793                        case FORMAT_TYPE_LONG:
1794                                save_arg(unsigned long);
1795                                break;
1796                        case FORMAT_TYPE_SIZE_T:
1797                                save_arg(size_t);
1798                                break;
1799                        case FORMAT_TYPE_PTRDIFF:
1800                                save_arg(ptrdiff_t);
1801                                break;
1802                        case FORMAT_TYPE_UBYTE:
1803                        case FORMAT_TYPE_BYTE:
1804                                save_arg(char);
1805                                break;
1806                        case FORMAT_TYPE_USHORT:
1807                        case FORMAT_TYPE_SHORT:
1808                                save_arg(short);
1809                                break;
1810                        default:
1811                                save_arg(int);
1812                        }
1813                }
1814        }
1815
1816        return (u32 *)(PTR_ALIGN(str, sizeof(u32))) - bin_buf;
1817#undef save_arg
1818}
1819EXPORT_SYMBOL_GPL(vbin_printf);
1820
1821/**
1822 * bstr_printf - Format a string from binary arguments and place it in a buffer
1823 * @buf: The buffer to place the result into
1824 * @size: The size of the buffer, including the trailing null space
1825 * @fmt: The format string to use
1826 * @bin_buf: Binary arguments for the format string
1827 *
1828 * This function like C99 vsnprintf, but the difference is that vsnprintf gets
1829 * arguments from stack, and bstr_printf gets arguments from @bin_buf which is
1830 * a binary buffer that generated by vbin_printf.
1831 *
1832 * The format follows C99 vsnprintf, but has some extensions:
1833 *  see vsnprintf comment for details.
1834 *
1835 * The return value is the number of characters which would
1836 * be generated for the given input, excluding the trailing
1837 * '\0', as per ISO C99. If you want to have the exact
1838 * number of characters written into @buf as return value
1839 * (not including the trailing '\0'), use vscnprintf(). If the
1840 * return is greater than or equal to @size, the resulting
1841 * string is truncated.
1842 */
1843int bstr_printf(char *buf, size_t size, const char *fmt, const u32 *bin_buf)
1844{
1845        struct printf_spec spec = {0};
1846        char *str, *end;
1847        const char *args = (const char *)bin_buf;
1848
1849        if (WARN_ON_ONCE((int) size < 0))
1850                return 0;
1851
1852        str = buf;
1853        end = buf + size;
1854
1855#define get_arg(type)                                                   \
1856({                                                                      \
1857        typeof(type) value;                                             \
1858        if (sizeof(type) == 8) {                                        \
1859                args = PTR_ALIGN(args, sizeof(u32));                    \
1860                *(u32 *)&value = *(u32 *)args;                          \
1861                *((u32 *)&value + 1) = *(u32 *)(args + 4);              \
1862        } else {                                                        \
1863                args = PTR_ALIGN(args, sizeof(type));                   \
1864                value = *(typeof(type) *)args;                          \
1865        }                                                               \
1866        args += sizeof(type);                                           \
1867        value;                                                          \
1868})
1869
1870        /* Make sure end is always >= buf */
1871        if (end < buf) {
1872                end = ((void *)-1);
1873                size = end - buf;
1874        }
1875
1876        while (*fmt) {
1877                const char *old_fmt = fmt;
1878                int read = format_decode(fmt, &spec);
1879
1880                fmt += read;
1881
1882                switch (spec.type) {
1883                case FORMAT_TYPE_NONE: {
1884                        int copy = read;
1885                        if (str < end) {
1886                                if (copy > end - str)
1887                                        copy = end - str;
1888                                memcpy(str, old_fmt, copy);
1889                        }
1890                        str += read;
1891                        break;
1892                }
1893
1894                case FORMAT_TYPE_WIDTH:
1895                        spec.field_width = get_arg(int);
1896                        break;
1897
1898                case FORMAT_TYPE_PRECISION:
1899                        spec.precision = get_arg(int);
1900                        break;
1901
1902                case FORMAT_TYPE_CHAR: {
1903                        char c;
1904
1905                        if (!(spec.flags & LEFT)) {
1906                                while (--spec.field_width > 0) {
1907                                        if (str < end)
1908                                                *str = ' ';
1909                                        ++str;
1910                                }
1911                        }
1912                        c = (unsigned char) get_arg(char);
1913                        if (str < end)
1914                                *str = c;
1915                        ++str;
1916                        while (--spec.field_width > 0) {
1917                                if (str < end)
1918                                        *str = ' ';
1919                                ++str;
1920                        }
1921                        break;
1922                }
1923
1924                case FORMAT_TYPE_STR: {
1925                        const char *str_arg = args;
1926                        args += strlen(str_arg) + 1;
1927                        str = string(str, end, (char *)str_arg, spec);
1928                        break;
1929                }
1930
1931                case FORMAT_TYPE_PTR:
1932                        str = pointer(fmt+1, str, end, get_arg(void *), spec);
1933                        while (isalnum(*fmt))
1934                                fmt++;
1935                        break;
1936
1937                case FORMAT_TYPE_PERCENT_CHAR:
1938                case FORMAT_TYPE_INVALID:
1939                        if (str < end)
1940                                *str = '%';
1941                        ++str;
1942                        break;
1943
1944                case FORMAT_TYPE_NRCHARS:
1945                        /* skip */
1946                        break;
1947
1948                default: {
1949                        unsigned long long num;
1950
1951                        switch (spec.type) {
1952
1953                        case FORMAT_TYPE_LONG_LONG:
1954                                num = get_arg(long long);
1955                                break;
1956                        case FORMAT_TYPE_ULONG:
1957                        case FORMAT_TYPE_LONG:
1958                                num = get_arg(unsigned long);
1959                                break;
1960                        case FORMAT_TYPE_SIZE_T:
1961                                num = get_arg(size_t);
1962                                break;
1963                        case FORMAT_TYPE_PTRDIFF:
1964                                num = get_arg(ptrdiff_t);
1965                                break;
1966                        case FORMAT_TYPE_UBYTE:
1967                                num = get_arg(unsigned char);
1968                                break;
1969                        case FORMAT_TYPE_BYTE:
1970                                num = get_arg(signed char);
1971                                break;
1972                        case FORMAT_TYPE_USHORT:
1973                                num = get_arg(unsigned short);
1974                                break;
1975                        case FORMAT_TYPE_SHORT:
1976                                num = get_arg(short);
1977                                break;
1978                        case FORMAT_TYPE_UINT:
1979                                num = get_arg(unsigned int);
1980                                break;
1981                        default:
1982                                num = get_arg(int);
1983                        }
1984
1985                        str = number(str, end, num, spec);
1986                } /* default: */
1987                } /* switch(spec.type) */
1988        } /* while(*fmt) */
1989
1990        if (size > 0) {
1991                if (str < end)
1992                        *str = '\0';
1993                else
1994                        end[-1] = '\0';
1995        }
1996
1997#undef get_arg
1998
1999        /* the trailing null byte doesn't count towards the total */
2000        return str - buf;
2001}
2002EXPORT_SYMBOL_GPL(bstr_printf);
2003
2004/**
2005 * bprintf - Parse a format string and place args' binary value in a buffer
2006 * @bin_buf: The buffer to place args' binary value
2007 * @size: The size of the buffer(by words(32bits), not characters)
2008 * @fmt: The format string to use
2009 * @...: Arguments for the format string
2010 *
2011 * The function returns the number of words(u32) written
2012 * into @bin_buf.
2013 */
2014int bprintf(u32 *bin_buf, size_t size, const char *fmt, ...)
2015{
2016        va_list args;
2017        int ret;
2018
2019        va_start(args, fmt);
2020        ret = vbin_printf(bin_buf, size, fmt, args);
2021        va_end(args);
2022
2023        return ret;
2024}
2025EXPORT_SYMBOL_GPL(bprintf);
2026
2027#endif /* CONFIG_BINARY_PRINTF */
2028
2029/**
2030 * vsscanf - Unformat a buffer into a list of arguments
2031 * @buf:        input buffer
2032 * @fmt:        format of buffer
2033 * @args:       arguments
2034 */
2035int vsscanf(const char *buf, const char *fmt, va_list args)
2036{
2037        const char *str = buf;
2038        char *next;
2039        char digit;
2040        int num = 0;
2041        u8 qualifier;
2042        unsigned int base;
2043        union {
2044                long long s;
2045                unsigned long long u;
2046        } val;
2047        s16 field_width;
2048        bool is_sign;
2049
2050        while (*fmt) {
2051                /* skip any white space in format */
2052                /* white space in format matchs any amount of
2053                 * white space, including none, in the input.
2054                 */
2055                if (isspace(*fmt)) {
2056                        fmt = skip_spaces(++fmt);
2057                        str = skip_spaces(str);
2058                }
2059
2060                /* anything that is not a conversion must match exactly */
2061                if (*fmt != '%' && *fmt) {
2062                        if (*fmt++ != *str++)
2063                                break;
2064                        continue;
2065                }
2066
2067                if (!*fmt)
2068                        break;
2069                ++fmt;
2070
2071                /* skip this conversion.
2072                 * advance both strings to next white space
2073                 */
2074                if (*fmt == '*') {
2075                        if (!*str)
2076                                break;
2077                        while (!isspace(*fmt) && *fmt != '%' && *fmt)
2078                                fmt++;
2079                        while (!isspace(*str) && *str)
2080                                str++;
2081                        continue;
2082                }
2083
2084                /* get field width */
2085                field_width = -1;
2086                if (isdigit(*fmt)) {
2087                        field_width = skip_atoi(&fmt);
2088                        if (field_width <= 0)
2089                                break;
2090                }
2091
2092                /* get conversion qualifier */
2093                qualifier = -1;
2094                if (*fmt == 'h' || _tolower(*fmt) == 'l' ||
2095                    _tolower(*fmt) == 'z') {
2096                        qualifier = *fmt++;
2097                        if (unlikely(qualifier == *fmt)) {
2098                                if (qualifier == 'h') {
2099                                        qualifier = 'H';
2100                                        fmt++;
2101                                } else if (qualifier == 'l') {
2102                                        qualifier = 'L';
2103                                        fmt++;
2104                                }
2105                        }
2106                }
2107
2108                if (!*fmt)
2109                        break;
2110
2111                if (*fmt == 'n') {
2112                        /* return number of characters read so far */
2113                        *va_arg(args, int *) = str - buf;
2114                        ++fmt;
2115                        continue;
2116                }
2117
2118                if (!*str)
2119                        break;
2120
2121                base = 10;
2122                is_sign = 0;
2123
2124                switch (*fmt++) {
2125                case 'c':
2126                {
2127                        char *s = (char *)va_arg(args, char*);
2128                        if (field_width == -1)
2129                                field_width = 1;
2130                        do {
2131                                *s++ = *str++;
2132                        } while (--field_width > 0 && *str);
2133                        num++;
2134                }
2135                continue;
2136                case 's':
2137                {
2138                        char *s = (char *)va_arg(args, char *);
2139                        if (field_width == -1)
2140                                field_width = SHRT_MAX;
2141                        /* first, skip leading white space in buffer */
2142                        str = skip_spaces(str);
2143
2144                        /* now copy until next white space */
2145                        while (*str && !isspace(*str) && field_width--)
2146                                *s++ = *str++;
2147                        *s = '\0';
2148                        num++;
2149                }
2150                continue;
2151                case 'o':
2152                        base = 8;
2153                        break;
2154                case 'x':
2155                case 'X':
2156                        base = 16;
2157                        break;
2158                case 'i':
2159                        base = 0;
2160                case 'd':
2161                        is_sign = 1;
2162                case 'u':
2163                        break;
2164                case '%':
2165                        /* looking for '%' in str */
2166                        if (*str++ != '%')
2167                                return num;
2168                        continue;
2169                default:
2170                        /* invalid format; stop here */
2171                        return num;
2172                }
2173
2174                /* have some sort of integer conversion.
2175                 * first, skip white space in buffer.
2176                 */
2177                str = skip_spaces(str);
2178
2179                digit = *str;
2180                if (is_sign && digit == '-')
2181                        digit = *(str + 1);
2182
2183                if (!digit
2184                    || (base == 16 && !isxdigit(digit))
2185                    || (base == 10 && !isdigit(digit))
2186                    || (base == 8 && (!isdigit(digit) || digit > '7'))
2187                    || (base == 0 && !isdigit(digit)))
2188                        break;
2189
2190                if (is_sign)
2191                        val.s = qualifier != 'L' ?
2192                                simple_strtol(str, &next, base) :
2193                                simple_strtoll(str, &next, base);
2194                else
2195                        val.u = qualifier != 'L' ?
2196                                simple_strtoul(str, &next, base) :
2197                                simple_strtoull(str, &next, base);
2198
2199                if (field_width > 0 && next - str > field_width) {
2200                        if (base == 0)
2201                                _parse_integer_fixup_radix(str, &base);
2202                        while (next - str > field_width) {
2203                                if (is_sign)
2204                                        val.s = div_s64(val.s, base);
2205                                else
2206                                        val.u = div_u64(val.u, base);
2207                                --next;
2208                        }
2209                }
2210
2211                switch (qualifier) {
2212                case 'H':       /* that's 'hh' in format */
2213                        if (is_sign)
2214                                *va_arg(args, signed char *) = val.s;
2215                        else
2216                                *va_arg(args, unsigned char *) = val.u;
2217                        break;
2218                case 'h':
2219                        if (is_sign)
2220                                *va_arg(args, short *) = val.s;
2221                        else
2222                                *va_arg(args, unsigned short *) = val.u;
2223                        break;
2224                case 'l':
2225                        if (is_sign)
2226                                *va_arg(args, long *) = val.s;
2227                        else
2228                                *va_arg(args, unsigned long *) = val.u;
2229                        break;
2230                case 'L':
2231                        if (is_sign)
2232                                *va_arg(args, long long *) = val.s;
2233                        else
2234                                *va_arg(args, unsigned long long *) = val.u;
2235                        break;
2236                case 'Z':
2237                case 'z':
2238                        *va_arg(args, size_t *) = val.u;
2239                        break;
2240                default:
2241                        if (is_sign)
2242                                *va_arg(args, int *) = val.s;
2243                        else
2244                                *va_arg(args, unsigned int *) = val.u;
2245                        break;
2246                }
2247                num++;
2248
2249                if (!next)
2250                        break;
2251                str = next;
2252        }
2253
2254        return num;
2255}
2256EXPORT_SYMBOL(vsscanf);
2257
2258/**
2259 * sscanf - Unformat a buffer into a list of arguments
2260 * @buf:        input buffer
2261 * @fmt:        formatting of buffer
2262 * @...:        resulting arguments
2263 */
2264int sscanf(const char *buf, const char *fmt, ...)
2265{
2266        va_list args;
2267        int i;
2268
2269        va_start(args, fmt);
2270        i = vsscanf(buf, fmt, args);
2271        va_end(args);
2272
2273        return i;
2274}
2275EXPORT_SYMBOL(sscanf);
2276
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