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/uaccess.h>
  27#include <linux/ioport.h>
  28#include <net/addrconf.h>
  29
  30#include <asm/page.h>           /* for PAGE_SIZE */
  31#include <asm/div64.h>
  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 */
  42unsigned long long simple_strtoull(const char *cp, char **endp, unsigned int base)
  43{
  44        unsigned long long result;
  45        unsigned int rv;
  46
  47        cp = _parse_integer_fixup_radix(cp, &base);
  48        rv = _parse_integer(cp, base, &result);
  49        /* FIXME */
  50        cp += (rv & ~KSTRTOX_OVERFLOW);
  51
  52        if (endp)
  53                *endp = (char *)cp;
  54
  55        return result;
  56}
  57EXPORT_SYMBOL(simple_strtoull);
  58
  59/**
  60 * simple_strtoul - convert a string to an unsigned long
  61 * @cp: The start of the string
  62 * @endp: A pointer to the end of the parsed string will be placed here
  63 * @base: The number base to use
  64 */
  65unsigned long simple_strtoul(const char *cp, char **endp, unsigned int base)
  66{
  67        return simple_strtoull(cp, endp, base);
  68}
  69EXPORT_SYMBOL(simple_strtoul);
  70
  71/**
  72 * simple_strtol - convert a string to a signed long
  73 * @cp: The start of the string
  74 * @endp: A pointer to the end of the parsed string will be placed here
  75 * @base: The number base to use
  76 */
  77long simple_strtol(const char *cp, char **endp, unsigned int base)
  78{
  79        if (*cp == '-')
  80                return -simple_strtoul(cp + 1, endp, base);
  81
  82        return simple_strtoul(cp, endp, base);
  83}
  84EXPORT_SYMBOL(simple_strtol);
  85
  86/**
  87 * simple_strtoll - convert a string to a signed long long
  88 * @cp: The start of the string
  89 * @endp: A pointer to the end of the parsed string will be placed here
  90 * @base: The number base to use
  91 */
  92long long simple_strtoll(const char *cp, char **endp, unsigned int base)
  93{
  94        if (*cp == '-')
  95                return -simple_strtoull(cp + 1, endp, base);
  96
  97        return simple_strtoull(cp, endp, base);
  98}
  99EXPORT_SYMBOL(simple_strtoll);
 100
 101static noinline_for_stack
 102int skip_atoi(const char **s)
 103{
 104        int i = 0;
 105
 106        while (isdigit(**s))
 107                i = i*10 + *((*s)++) - '0';
 108
 109        return i;
 110}
 111
 112/* Decimal conversion is by far the most typical, and is used
 113 * for /proc and /sys data. This directly impacts e.g. top performance
 114 * with many processes running. We optimize it for speed
 115 * using ideas described at <http://www.cs.uiowa.edu/~jones/bcd/divide.html>
 116 * (with permission from the author, Douglas W. Jones).
 117 */
 118
 119#if BITS_PER_LONG != 32 || BITS_PER_LONG_LONG != 64
 120/* Formats correctly any integer in [0, 999999999] */
 121static noinline_for_stack
 122char *put_dec_full9(char *buf, unsigned q)
 123{
 124        unsigned r;
 125
 126        /*
 127         * Possible ways to approx. divide by 10
 128         * (x * 0x1999999a) >> 32 x < 1073741829 (multiply must be 64-bit)
 129         * (x * 0xcccd) >> 19     x <      81920 (x < 262149 when 64-bit mul)
 130         * (x * 0x6667) >> 18     x <      43699
 131         * (x * 0x3334) >> 17     x <      16389
 132         * (x * 0x199a) >> 16     x <      16389
 133         * (x * 0x0ccd) >> 15     x <      16389
 134         * (x * 0x0667) >> 14     x <       2739
 135         * (x * 0x0334) >> 13     x <       1029
 136         * (x * 0x019a) >> 12     x <       1029
 137         * (x * 0x00cd) >> 11     x <       1029 shorter code than * 0x67 (on i386)
 138         * (x * 0x0067) >> 10     x <        179
 139         * (x * 0x0034) >>  9     x <         69 same
 140         * (x * 0x001a) >>  8     x <         69 same
 141         * (x * 0x000d) >>  7     x <         69 same, shortest code (on i386)
 142         * (x * 0x0007) >>  6     x <         19
 143         * See <http://www.cs.uiowa.edu/~jones/bcd/divide.html>
 144         */
 145        r      = (q * (uint64_t)0x1999999a) >> 32;
 146        *buf++ = (q - 10 * r) + '0'; /* 1 */
 147        q      = (r * (uint64_t)0x1999999a) >> 32;
 148        *buf++ = (r - 10 * q) + '0'; /* 2 */
 149        r      = (q * (uint64_t)0x1999999a) >> 32;
 150        *buf++ = (q - 10 * r) + '0'; /* 3 */
 151        q      = (r * (uint64_t)0x1999999a) >> 32;
 152        *buf++ = (r - 10 * q) + '0'; /* 4 */
 153        r      = (q * (uint64_t)0x1999999a) >> 32;
 154        *buf++ = (q - 10 * r) + '0'; /* 5 */
 155        /* Now value is under 10000, can avoid 64-bit multiply */
 156        q      = (r * 0x199a) >> 16;
 157        *buf++ = (r - 10 * q)  + '0'; /* 6 */
 158        r      = (q * 0xcd) >> 11;
 159        *buf++ = (q - 10 * r)  + '0'; /* 7 */
 160        q      = (r * 0xcd) >> 11;
 161        *buf++ = (r - 10 * q) + '0'; /* 8 */
 162        *buf++ = q + '0'; /* 9 */
 163        return buf;
 164}
 165#endif
 166
 167/* Similar to above but do not pad with zeros.
 168 * Code can be easily arranged to print 9 digits too, but our callers
 169 * always call put_dec_full9() instead when the number has 9 decimal digits.
 170 */
 171static noinline_for_stack
 172char *put_dec_trunc8(char *buf, unsigned r)
 173{
 174        unsigned q;
 175
 176        /* Copy of previous function's body with added early returns */
 177        q      = (r * (uint64_t)0x1999999a) >> 32;
 178        *buf++ = (r - 10 * q) + '0'; /* 2 */
 179        if (q == 0)
 180                return buf;
 181        r      = (q * (uint64_t)0x1999999a) >> 32;
 182        *buf++ = (q - 10 * r) + '0'; /* 3 */
 183        if (r == 0)
 184                return buf;
 185        q      = (r * (uint64_t)0x1999999a) >> 32;
 186        *buf++ = (r - 10 * q) + '0'; /* 4 */
 187        if (q == 0)
 188                return buf;
 189        r      = (q * (uint64_t)0x1999999a) >> 32;
 190        *buf++ = (q - 10 * r) + '0'; /* 5 */
 191        if (r == 0)
 192                return buf;
 193        q      = (r * 0x199a) >> 16;
 194        *buf++ = (r - 10 * q)  + '0'; /* 6 */
 195        if (q == 0)
 196                return buf;
 197        r      = (q * 0xcd) >> 11;
 198        *buf++ = (q - 10 * r)  + '0'; /* 7 */
 199        if (r == 0)
 200                return buf;
 201        q      = (r * 0xcd) >> 11;
 202        *buf++ = (r - 10 * q) + '0'; /* 8 */
 203        if (q == 0)
 204                return buf;
 205        *buf++ = q + '0'; /* 9 */
 206        return buf;
 207}
 208
 209/* There are two algorithms to print larger numbers.
 210 * One is generic: divide by 1000000000 and repeatedly print
 211 * groups of (up to) 9 digits. It's conceptually simple,
 212 * but requires a (unsigned long long) / 1000000000 division.
 213 *
 214 * Second algorithm splits 64-bit unsigned long long into 16-bit chunks,
 215 * manipulates them cleverly and generates groups of 4 decimal digits.
 216 * It so happens that it does NOT require long long division.
 217 *
 218 * If long is > 32 bits, division of 64-bit values is relatively easy,
 219 * and we will use the first algorithm.
 220 * If long long is > 64 bits (strange architecture with VERY large long long),
 221 * second algorithm can't be used, and we again use the first one.
 222 *
 223 * Else (if long is 32 bits and long long is 64 bits) we use second one.
 224 */
 225
 226#if BITS_PER_LONG != 32 || BITS_PER_LONG_LONG != 64
 227
 228/* First algorithm: generic */
 229
 230static
 231char *put_dec(char *buf, unsigned long long n)
 232{
 233        if (n >= 100*1000*1000) {
 234                while (n >= 1000*1000*1000)
 235                        buf = put_dec_full9(buf, do_div(n, 1000*1000*1000));
 236                if (n >= 100*1000*1000)
 237                        return put_dec_full9(buf, n);
 238        }
 239        return put_dec_trunc8(buf, n);
 240}
 241
 242#else
 243
 244/* Second algorithm: valid only for 64-bit long longs */
 245
 246static noinline_for_stack
 247char *put_dec_full4(char *buf, unsigned q)
 248{
 249        unsigned r;
 250        r      = (q * 0xcccd) >> 19;
 251        *buf++ = (q - 10 * r) + '0';
 252        q      = (r * 0x199a) >> 16;
 253        *buf++ = (r - 10 * q)  + '0';
 254        r      = (q * 0xcd) >> 11;
 255        *buf++ = (q - 10 * r)  + '0';
 256        *buf++ = r + '0';
 257        return buf;
 258}
 259
 260/* Based on code by Douglas W. Jones found at
 261 * <http://www.cs.uiowa.edu/~jones/bcd/decimal.html#sixtyfour>
 262 * (with permission from the author).
 263 * Performs no 64-bit division and hence should be fast on 32-bit machines.
 264 */
 265static
 266char *put_dec(char *buf, unsigned long long n)
 267{
 268        uint32_t d3, d2, d1, q, h;
 269
 270        if (n < 100*1000*1000)
 271                return put_dec_trunc8(buf, n);
 272
 273        d1  = ((uint32_t)n >> 16); /* implicit "& 0xffff" */
 274        h   = (n >> 32);
 275        d2  = (h      ) & 0xffff;
 276        d3  = (h >> 16); /* implicit "& 0xffff" */
 277
 278        q   = 656 * d3 + 7296 * d2 + 5536 * d1 + ((uint32_t)n & 0xffff);
 279
 280        buf = put_dec_full4(buf, q % 10000);
 281        q   = q / 10000;
 282
 283        d1  = q + 7671 * d3 + 9496 * d2 + 6 * d1;
 284        buf = put_dec_full4(buf, d1 % 10000);
 285        q   = d1 / 10000;
 286
 287        d2  = q + 4749 * d3 + 42 * d2;
 288        buf = put_dec_full4(buf, d2 % 10000);
 289        q   = d2 / 10000;
 290
 291        d3  = q + 281 * d3;
 292        if (!d3)
 293                goto done;
 294        buf = put_dec_full4(buf, d3 % 10000);
 295        q   = d3 / 10000;
 296        if (!q)
 297                goto done;
 298        buf = put_dec_full4(buf, q);
 299 done:
 300        while (buf[-1] == '0')
 301                --buf;
 302
 303        return buf;
 304}
 305
 306#endif
 307
 308/*
 309 * Convert passed number to decimal string.
 310 * Returns the length of string.  On buffer overflow, returns 0.
 311 *
 312 * If speed is not important, use snprintf(). It's easy to read the code.
 313 */
 314int num_to_str(char *buf, int size, unsigned long long num)
 315{
 316        char tmp[sizeof(num) * 3];
 317        int idx, len;
 318
 319        /* put_dec() may work incorrectly for num = 0 (generate "", not "0") */
 320        if (num <= 9) {
 321                tmp[0] = '0' + num;
 322                len = 1;
 323        } else {
 324                len = put_dec(tmp, num) - tmp;
 325        }
 326
 327        if (len > size)
 328                return 0;
 329        for (idx = 0; idx < len; ++idx)
 330                buf[idx] = tmp[len - idx - 1];
 331        return len;
 332}
 333
 334#define ZEROPAD 1               /* pad with zero */
 335#define SIGN    2               /* unsigned/signed long */
 336#define PLUS    4               /* show plus */
 337#define SPACE   8               /* space if plus */
 338#define LEFT    16              /* left justified */
 339#define SMALL   32              /* use lowercase in hex (must be 32 == 0x20) */
 340#define SPECIAL 64              /* prefix hex with "0x", octal with "0" */
 341
 342enum format_type {
 343        FORMAT_TYPE_NONE, /* Just a string part */
 344        FORMAT_TYPE_WIDTH,
 345        FORMAT_TYPE_PRECISION,
 346        FORMAT_TYPE_CHAR,
 347        FORMAT_TYPE_STR,
 348        FORMAT_TYPE_PTR,
 349        FORMAT_TYPE_PERCENT_CHAR,
 350        FORMAT_TYPE_INVALID,
 351        FORMAT_TYPE_LONG_LONG,
 352        FORMAT_TYPE_ULONG,
 353        FORMAT_TYPE_LONG,
 354        FORMAT_TYPE_UBYTE,
 355        FORMAT_TYPE_BYTE,
 356        FORMAT_TYPE_USHORT,
 357        FORMAT_TYPE_SHORT,
 358        FORMAT_TYPE_UINT,
 359        FORMAT_TYPE_INT,
 360        FORMAT_TYPE_NRCHARS,
 361        FORMAT_TYPE_SIZE_T,
 362        FORMAT_TYPE_PTRDIFF
 363};
 364
 365struct printf_spec {
 366        u8      type;           /* format_type enum */
 367        u8      flags;          /* flags to number() */
 368        u8      base;           /* number base, 8, 10 or 16 only */
 369        u8      qualifier;      /* number qualifier, one of 'hHlLtzZ' */
 370        s16     field_width;    /* width of output field */
 371        s16     precision;      /* # of digits/chars */
 372};
 373
 374static noinline_for_stack
 375char *number(char *buf, char *end, unsigned long long num,
 376             struct printf_spec spec)
 377{
 378        /* we are called with base 8, 10 or 16, only, thus don't need "G..."  */
 379        static const char digits[16] = "0123456789ABCDEF"; /* "GHIJKLMNOPQRSTUVWXYZ"; */
 380
 381        char tmp[66];
 382        char sign;
 383        char locase;
 384        int need_pfx = ((spec.flags & SPECIAL) && spec.base != 10);
 385        int i;
 386        bool is_zero = num == 0LL;
 387
 388        /* locase = 0 or 0x20. ORing digits or letters with 'locase'
 389         * produces same digits or (maybe lowercased) letters */
 390        locase = (spec.flags & SMALL);
 391        if (spec.flags & LEFT)
 392                spec.flags &= ~ZEROPAD;
 393        sign = 0;
 394        if (spec.flags & SIGN) {
 395                if ((signed long long)num < 0) {
 396                        sign = '-';
 397                        num = -(signed long long)num;
 398                        spec.field_width--;
 399                } else if (spec.flags & PLUS) {
 400                        sign = '+';
 401                        spec.field_width--;
 402                } else if (spec.flags & SPACE) {
 403                        sign = ' ';
 404                        spec.field_width--;
 405                }
 406        }
 407        if (need_pfx) {
 408                if (spec.base == 16)
 409                        spec.field_width -= 2;
 410                else if (!is_zero)
 411                        spec.field_width--;
 412        }
 413
 414        /* generate full string in tmp[], in reverse order */
 415        i = 0;
 416        if (num < spec.base)
 417                tmp[i++] = digits[num] | locase;
 418        /* Generic code, for any base:
 419        else do {
 420                tmp[i++] = (digits[do_div(num,base)] | locase);
 421        } while (num != 0);
 422        */
 423        else if (spec.base != 10) { /* 8 or 16 */
 424                int mask = spec.base - 1;
 425                int shift = 3;
 426
 427                if (spec.base == 16)
 428                        shift = 4;
 429                do {
 430                        tmp[i++] = (digits[((unsigned char)num) & mask] | locase);
 431                        num >>= shift;
 432                } while (num);
 433        } else { /* base 10 */
 434                i = put_dec(tmp, num) - tmp;
 435        }
 436
 437        /* printing 100 using %2d gives "100", not "00" */
 438        if (i > spec.precision)
 439                spec.precision = i;
 440        /* leading space padding */
 441        spec.field_width -= spec.precision;
 442        if (!(spec.flags & (ZEROPAD+LEFT))) {
 443                while (--spec.field_width >= 0) {
 444                        if (buf < end)
 445                                *buf = ' ';
 446                        ++buf;
 447                }
 448        }
 449        /* sign */
 450        if (sign) {
 451                if (buf < end)
 452                        *buf = sign;
 453                ++buf;
 454        }
 455        /* "0x" / "0" prefix */
 456        if (need_pfx) {
 457                if (spec.base == 16 || !is_zero) {
 458                        if (buf < end)
 459                                *buf = '0';
 460                        ++buf;
 461                }
 462                if (spec.base == 16) {
 463                        if (buf < end)
 464                                *buf = ('X' | locase);
 465                        ++buf;
 466                }
 467        }
 468        /* zero or space padding */
 469        if (!(spec.flags & LEFT)) {
 470                char c = (spec.flags & ZEROPAD) ? '0' : ' ';
 471                while (--spec.field_width >= 0) {
 472                        if (buf < end)
 473                                *buf = c;
 474                        ++buf;
 475                }
 476        }
 477        /* hmm even more zero padding? */
 478        while (i <= --spec.precision) {
 479                if (buf < end)
 480                        *buf = '0';
 481                ++buf;
 482        }
 483        /* actual digits of result */
 484        while (--i >= 0) {
 485                if (buf < end)
 486                        *buf = tmp[i];
 487                ++buf;
 488        }
 489        /* trailing space padding */
 490        while (--spec.field_width >= 0) {
 491                if (buf < end)
 492                        *buf = ' ';
 493                ++buf;
 494        }
 495
 496        return buf;
 497}
 498
 499static noinline_for_stack
 500char *string(char *buf, char *end, const char *s, struct printf_spec spec)
 501{
 502        int len, i;
 503
 504        if ((unsigned long)s < PAGE_SIZE)
 505                s = "(null)";
 506
 507        len = strnlen(s, spec.precision);
 508
 509        if (!(spec.flags & LEFT)) {
 510                while (len < spec.field_width--) {
 511                        if (buf < end)
 512                                *buf = ' ';
 513                        ++buf;
 514                }
 515        }
 516        for (i = 0; i < len; ++i) {
 517                if (buf < end)
 518                        *buf = *s;
 519                ++buf; ++s;
 520        }
 521        while (len < spec.field_width--) {
 522                if (buf < end)
 523                        *buf = ' ';
 524                ++buf;
 525        }
 526
 527        return buf;
 528}
 529
 530static noinline_for_stack
 531char *symbol_string(char *buf, char *end, void *ptr,
 532                    struct printf_spec spec, char ext)
 533{
 534        unsigned long value = (unsigned long) ptr;
 535#ifdef CONFIG_KALLSYMS
 536        char sym[KSYM_SYMBOL_LEN];
 537        if (ext == 'B')
 538                sprint_backtrace(sym, value);
 539        else if (ext != 'f' && ext != 's')
 540                sprint_symbol(sym, value);
 541        else
 542                sprint_symbol_no_offset(sym, value);
 543
 544        return string(buf, end, sym, spec);
 545#else
 546        spec.field_width = 2 * sizeof(void *);
 547        spec.flags |= SPECIAL | SMALL | ZEROPAD;
 548        spec.base = 16;
 549
 550        return number(buf, end, value, spec);
 551#endif
 552}
 553
 554static noinline_for_stack
 555char *resource_string(char *buf, char *end, struct resource *res,
 556                      struct printf_spec spec, const char *fmt)
 557{
 558#ifndef IO_RSRC_PRINTK_SIZE
 559#define IO_RSRC_PRINTK_SIZE     6
 560#endif
 561
 562#ifndef MEM_RSRC_PRINTK_SIZE
 563#define MEM_RSRC_PRINTK_SIZE    10
 564#endif
 565        static const struct printf_spec io_spec = {
 566                .base = 16,
 567                .field_width = IO_RSRC_PRINTK_SIZE,
 568                .precision = -1,
 569                .flags = SPECIAL | SMALL | ZEROPAD,
 570        };
 571        static const struct printf_spec mem_spec = {
 572                .base = 16,
 573                .field_width = MEM_RSRC_PRINTK_SIZE,
 574                .precision = -1,
 575                .flags = SPECIAL | SMALL | ZEROPAD,
 576        };
 577        static const struct printf_spec bus_spec = {
 578                .base = 16,
 579                .field_width = 2,
 580                .precision = -1,
 581                .flags = SMALL | ZEROPAD,
 582        };
 583        static const struct printf_spec dec_spec = {
 584                .base = 10,
 585                .precision = -1,
 586                .flags = 0,
 587        };
 588        static const struct printf_spec str_spec = {
 589                .field_width = -1,
 590                .precision = 10,
 591                .flags = LEFT,
 592        };
 593        static const struct printf_spec flag_spec = {
 594                .base = 16,
 595                .precision = -1,
 596                .flags = SPECIAL | SMALL,
 597        };
 598
 599        /* 32-bit res (sizeof==4): 10 chars in dec, 10 in hex ("0x" + 8)
 600         * 64-bit res (sizeof==8): 20 chars in dec, 18 in hex ("0x" + 16) */
 601#define RSRC_BUF_SIZE           ((2 * sizeof(resource_size_t)) + 4)
 602#define FLAG_BUF_SIZE           (2 * sizeof(res->flags))
 603#define DECODED_BUF_SIZE        sizeof("[mem - 64bit pref window disabled]")
 604#define RAW_BUF_SIZE            sizeof("[mem - flags 0x]")
 605        char sym[max(2*RSRC_BUF_SIZE + DECODED_BUF_SIZE,
 606                     2*RSRC_BUF_SIZE + FLAG_BUF_SIZE + RAW_BUF_SIZE)];
 607
 608        char *p = sym, *pend = sym + sizeof(sym);
 609        int decode = (fmt[0] == 'R') ? 1 : 0;
 610        const struct printf_spec *specp;
 611
 612        *p++ = '[';
 613        if (res->flags & IORESOURCE_IO) {
 614                p = string(p, pend, "io  ", str_spec);
 615                specp = &io_spec;
 616        } else if (res->flags & IORESOURCE_MEM) {
 617                p = string(p, pend, "mem ", str_spec);
 618                specp = &mem_spec;
 619        } else if (res->flags & IORESOURCE_IRQ) {
 620                p = string(p, pend, "irq ", str_spec);
 621                specp = &dec_spec;
 622        } else if (res->flags & IORESOURCE_DMA) {
 623                p = string(p, pend, "dma ", str_spec);
 624                specp = &dec_spec;
 625        } else if (res->flags & IORESOURCE_BUS) {
 626                p = string(p, pend, "bus ", str_spec);
 627                specp = &bus_spec;
 628        } else {
 629                p = string(p, pend, "??? ", str_spec);
 630                specp = &mem_spec;
 631                decode = 0;
 632        }
 633        p = number(p, pend, res->start, *specp);
 634        if (res->start != res->end) {
 635                *p++ = '-';
 636                p = number(p, pend, res->end, *specp);
 637        }
 638        if (decode) {
 639                if (res->flags & IORESOURCE_MEM_64)
 640                        p = string(p, pend, " 64bit", str_spec);
 641                if (res->flags & IORESOURCE_PREFETCH)
 642                        p = string(p, pend, " pref", str_spec);
 643                if (res->flags & IORESOURCE_WINDOW)
 644                        p = string(p, pend, " window", str_spec);
 645                if (res->flags & IORESOURCE_DISABLED)
 646                        p = string(p, pend, " disabled", str_spec);
 647        } else {
 648                p = string(p, pend, " flags ", str_spec);
 649                p = number(p, pend, res->flags, flag_spec);
 650        }
 651        *p++ = ']';
 652        *p = '\0';
 653
 654        return string(buf, end, sym, spec);
 655}
 656
 657static noinline_for_stack
 658char *hex_string(char *buf, char *end, u8 *addr, struct printf_spec spec,
 659                 const char *fmt)
 660{
 661        int i, len = 1;         /* if we pass '%ph[CDN]', field witdh remains
 662                                   negative value, fallback to the default */
 663        char separator;
 664
 665        if (spec.field_width == 0)
 666                /* nothing to print */
 667                return buf;
 668
 669        if (ZERO_OR_NULL_PTR(addr))
 670                /* NULL pointer */
 671                return string(buf, end, NULL, spec);
 672
 673        switch (fmt[1]) {
 674        case 'C':
 675                separator = ':';
 676                break;
 677        case 'D':
 678                separator = '-';
 679                break;
 680        case 'N':
 681                separator = 0;
 682                break;
 683        default:
 684                separator = ' ';
 685                break;
 686        }
 687
 688        if (spec.field_width > 0)
 689                len = min_t(int, spec.field_width, 64);
 690
 691        for (i = 0; i < len && buf < end - 1; i++) {
 692                buf = hex_byte_pack(buf, addr[i]);
 693
 694                if (buf < end && separator && i != len - 1)
 695                        *buf++ = separator;
 696        }
 697
 698        return buf;
 699}
 700
 701static noinline_for_stack
 702char *mac_address_string(char *buf, char *end, u8 *addr,
 703                         struct printf_spec spec, const char *fmt)
 704{
 705        char mac_addr[sizeof("xx:xx:xx:xx:xx:xx")];
 706        char *p = mac_addr;
 707        int i;
 708        char separator;
 709        bool reversed = false;
 710
 711        switch (fmt[1]) {
 712        case 'F':
 713                separator = '-';
 714                break;
 715
 716        case 'R':
 717                reversed = true;
 718                /* fall through */
 719
 720        default:
 721                separator = ':';
 722                break;
 723        }
 724
 725        for (i = 0; i < 6; i++) {
 726                if (reversed)
 727                        p = hex_byte_pack(p, addr[5 - i]);
 728                else
 729                        p = hex_byte_pack(p, addr[i]);
 730
 731                if (fmt[0] == 'M' && i != 5)
 732                        *p++ = separator;
 733        }
 734        *p = '\0';
 735
 736        return string(buf, end, mac_addr, spec);
 737}
 738
 739static noinline_for_stack
 740char *ip4_string(char *p, const u8 *addr, const char *fmt)
 741{
 742        int i;
 743        bool leading_zeros = (fmt[0] == 'i');
 744        int index;
 745        int step;
 746
 747        switch (fmt[2]) {
 748        case 'h':
 749#ifdef __BIG_ENDIAN
 750                index = 0;
 751                step = 1;
 752#else
 753                index = 3;
 754                step = -1;
 755#endif
 756                break;
 757        case 'l':
 758                index = 3;
 759                step = -1;
 760                break;
 761        case 'n':
 762        case 'b':
 763        default:
 764                index = 0;
 765                step = 1;
 766                break;
 767        }
 768        for (i = 0; i < 4; i++) {
 769                char temp[3];   /* hold each IP quad in reverse order */
 770                int digits = put_dec_trunc8(temp, addr[index]) - temp;
 771                if (leading_zeros) {
 772                        if (digits < 3)
 773                                *p++ = '0';
 774                        if (digits < 2)
 775                                *p++ = '0';
 776                }
 777                /* reverse the digits in the quad */
 778                while (digits--)
 779                        *p++ = temp[digits];
 780                if (i < 3)
 781                        *p++ = '.';
 782                index += step;
 783        }
 784        *p = '\0';
 785
 786        return p;
 787}
 788
 789static noinline_for_stack
 790char *ip6_compressed_string(char *p, const char *addr)
 791{
 792        int i, j, range;
 793        unsigned char zerolength[8];
 794        int longest = 1;
 795        int colonpos = -1;
 796        u16 word;
 797        u8 hi, lo;
 798        bool needcolon = false;
 799        bool useIPv4;
 800        struct in6_addr in6;
 801
 802        memcpy(&in6, addr, sizeof(struct in6_addr));
 803
 804        useIPv4 = ipv6_addr_v4mapped(&in6) || ipv6_addr_is_isatap(&in6);
 805
 806        memset(zerolength, 0, sizeof(zerolength));
 807
 808        if (useIPv4)
 809                range = 6;
 810        else
 811                range = 8;
 812
 813        /* find position of longest 0 run */
 814        for (i = 0; i < range; i++) {
 815                for (j = i; j < range; j++) {
 816                        if (in6.s6_addr16[j] != 0)
 817                                break;
 818                        zerolength[i]++;
 819                }
 820        }
 821        for (i = 0; i < range; i++) {
 822                if (zerolength[i] > longest) {
 823                        longest = zerolength[i];
 824                        colonpos = i;
 825                }
 826        }
 827        if (longest == 1)               /* don't compress a single 0 */
 828                colonpos = -1;
 829
 830        /* emit address */
 831        for (i = 0; i < range; i++) {
 832                if (i == colonpos) {
 833                        if (needcolon || i == 0)
 834                                *p++ = ':';
 835                        *p++ = ':';
 836                        needcolon = false;
 837                        i += longest - 1;
 838                        continue;
 839                }
 840                if (needcolon) {
 841                        *p++ = ':';
 842                        needcolon = false;
 843                }
 844                /* hex u16 without leading 0s */
 845                word = ntohs(in6.s6_addr16[i]);
 846                hi = word >> 8;
 847                lo = word & 0xff;
 848                if (hi) {
 849                        if (hi > 0x0f)
 850                                p = hex_byte_pack(p, hi);
 851                        else
 852                                *p++ = hex_asc_lo(hi);
 853                        p = hex_byte_pack(p, lo);
 854                }
 855                else if (lo > 0x0f)
 856                        p = hex_byte_pack(p, lo);
 857                else
 858                        *p++ = hex_asc_lo(lo);
 859                needcolon = true;
 860        }
 861
 862        if (useIPv4) {
 863                if (needcolon)
 864                        *p++ = ':';
 865                p = ip4_string(p, &in6.s6_addr[12], "I4");
 866        }
 867        *p = '\0';
 868
 869        return p;
 870}
 871
 872static noinline_for_stack
 873char *ip6_string(char *p, const char *addr, const char *fmt)
 874{
 875        int i;
 876
 877        for (i = 0; i < 8; i++) {
 878                p = hex_byte_pack(p, *addr++);
 879                p = hex_byte_pack(p, *addr++);
 880                if (fmt[0] == 'I' && i != 7)
 881                        *p++ = ':';
 882        }
 883        *p = '\0';
 884
 885        return p;
 886}
 887
 888static noinline_for_stack
 889char *ip6_addr_string(char *buf, char *end, const u8 *addr,
 890                      struct printf_spec spec, const char *fmt)
 891{
 892        char ip6_addr[sizeof("xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255")];
 893
 894        if (fmt[0] == 'I' && fmt[2] == 'c')
 895                ip6_compressed_string(ip6_addr, addr);
 896        else
 897                ip6_string(ip6_addr, addr, fmt);
 898
 899        return string(buf, end, ip6_addr, spec);
 900}
 901
 902static noinline_for_stack
 903char *ip4_addr_string(char *buf, char *end, const u8 *addr,
 904                      struct printf_spec spec, const char *fmt)
 905{
 906        char ip4_addr[sizeof("255.255.255.255")];
 907
 908        ip4_string(ip4_addr, addr, fmt);
 909
 910        return string(buf, end, ip4_addr, spec);
 911}
 912
 913static noinline_for_stack
 914char *uuid_string(char *buf, char *end, const u8 *addr,
 915                  struct printf_spec spec, const char *fmt)
 916{
 917        char uuid[sizeof("xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx")];
 918        char *p = uuid;
 919        int i;
 920        static const u8 be[16] = {0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15};
 921        static const u8 le[16] = {3,2,1,0,5,4,7,6,8,9,10,11,12,13,14,15};
 922        const u8 *index = be;
 923        bool uc = false;
 924
 925        switch (*(++fmt)) {
 926        case 'L':
 927                uc = true;              /* fall-through */
 928        case 'l':
 929                index = le;
 930                break;
 931        case 'B':
 932                uc = true;
 933                break;
 934        }
 935
 936        for (i = 0; i < 16; i++) {
 937                p = hex_byte_pack(p, addr[index[i]]);
 938                switch (i) {
 939                case 3:
 940                case 5:
 941                case 7:
 942                case 9:
 943                        *p++ = '-';
 944                        break;
 945                }
 946        }
 947
 948        *p = 0;
 949
 950        if (uc) {
 951                p = uuid;
 952                do {
 953                        *p = toupper(*p);
 954                } while (*(++p));
 955        }
 956
 957        return string(buf, end, uuid, spec);
 958}
 959
 960static
 961char *netdev_feature_string(char *buf, char *end, const u8 *addr,
 962                      struct printf_spec spec)
 963{
 964        spec.flags |= SPECIAL | SMALL | ZEROPAD;
 965        if (spec.field_width == -1)
 966                spec.field_width = 2 + 2 * sizeof(netdev_features_t);
 967        spec.base = 16;
 968
 969        return number(buf, end, *(const netdev_features_t *)addr, spec);
 970}
 971
 972int kptr_restrict __read_mostly;
 973
 974/*
 975 * Show a '%p' thing.  A kernel extension is that the '%p' is followed
 976 * by an extra set of alphanumeric characters that are extended format
 977 * specifiers.
 978 *
 979 * Right now we handle:
 980 *
 981 * - 'F' For symbolic function descriptor pointers with offset
 982 * - 'f' For simple symbolic function names without offset
 983 * - 'S' For symbolic direct pointers with offset
 984 * - 's' For symbolic direct pointers without offset
 985 * - 'B' For backtraced symbolic direct pointers with offset
 986 * - 'R' For decoded struct resource, e.g., [mem 0x0-0x1f 64bit pref]
 987 * - 'r' For raw struct resource, e.g., [mem 0x0-0x1f flags 0x201]
 988 * - 'M' For a 6-byte MAC address, it prints the address in the
 989 *       usual colon-separated hex notation
 990 * - 'm' For a 6-byte MAC address, it prints the hex address without colons
 991 * - 'MF' For a 6-byte MAC FDDI address, it prints the address
 992 *       with a dash-separated hex notation
 993 * - '[mM]R For a 6-byte MAC address, Reverse order (Bluetooth)
 994 * - 'I' [46] for IPv4/IPv6 addresses printed in the usual way
 995 *       IPv4 uses dot-separated decimal without leading 0's (1.2.3.4)
 996 *       IPv6 uses colon separated network-order 16 bit hex with leading 0's
 997 * - 'i' [46] for 'raw' IPv4/IPv6 addresses
 998 *       IPv6 omits the colons (01020304...0f)
 999 *       IPv4 uses dot-separated decimal with leading 0's (010.123.045.006)
1000 * - '[Ii]4[hnbl]' IPv4 addresses in host, network, big or little endian order
1001 * - 'I6c' for IPv6 addresses printed as specified by
1002 *       http://tools.ietf.org/html/rfc5952
1003 * - 'U' For a 16 byte UUID/GUID, it prints the UUID/GUID in the form
1004 *       "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx"
1005 *       Options for %pU are:
1006 *         b big endian lower case hex (default)
1007 *         B big endian UPPER case hex
1008 *         l little endian lower case hex
1009 *         L little endian UPPER case hex
1010 *           big endian output byte order is:
1011 *             [0][1][2][3]-[4][5]-[6][7]-[8][9]-[10][11][12][13][14][15]
1012 *           little endian output byte order is:
1013 *             [3][2][1][0]-[5][4]-[7][6]-[8][9]-[10][11][12][13][14][15]
1014 * - 'V' For a struct va_format which contains a format string * and va_list *,
1015 *       call vsnprintf(->format, *->va_list).
1016 *       Implements a "recursive vsnprintf".
1017 *       Do not use this feature without some mechanism to verify the
1018 *       correctness of the format string and va_list arguments.
1019 * - 'K' For a kernel pointer that should be hidden from unprivileged users
1020 * - 'NF' For a netdev_features_t
1021 * - 'h[CDN]' For a variable-length buffer, it prints it as a hex string with
1022 *            a certain separator (' ' by default):
1023 *              C colon
1024 *              D dash
1025 *              N no separator
1026 *            The maximum supported length is 64 bytes of the input. Consider
1027 *            to use print_hex_dump() for the larger input.
1028 *
1029 * Note: The difference between 'S' and 'F' is that on ia64 and ppc64
1030 * function pointers are really function descriptors, which contain a
1031 * pointer to the real address.
1032 */
1033static noinline_for_stack
1034char *pointer(const char *fmt, char *buf, char *end, void *ptr,
1035              struct printf_spec spec)
1036{
1037        int default_width = 2 * sizeof(void *) + (spec.flags & SPECIAL ? 2 : 0);
1038
1039        if (!ptr && *fmt != 'K') {
1040                /*
1041                 * Print (null) with the same width as a pointer so it makes
1042                 * tabular output look nice.
1043                 */
1044                if (spec.field_width == -1)
1045                        spec.field_width = default_width;
1046                return string(buf, end, "(null)", spec);
1047        }
1048
1049        switch (*fmt) {
1050        case 'F':
1051        case 'f':
1052                ptr = dereference_function_descriptor(ptr);
1053                /* Fallthrough */
1054        case 'S':
1055        case 's':
1056        case 'B':
1057                return symbol_string(buf, end, ptr, spec, *fmt);
1058        case 'R':
1059        case 'r':
1060                return resource_string(buf, end, ptr, spec, fmt);
1061        case 'h':
1062                return hex_string(buf, end, ptr, spec, fmt);
1063        case 'M':                       /* Colon separated: 00:01:02:03:04:05 */
1064        case 'm':                       /* Contiguous: 000102030405 */
1065                                        /* [mM]F (FDDI) */
1066                                        /* [mM]R (Reverse order; Bluetooth) */
1067                return mac_address_string(buf, end, ptr, spec, fmt);
1068        case 'I':                       /* Formatted IP supported
1069                                         * 4:   1.2.3.4
1070                                         * 6:   0001:0203:...:0708
1071                                         * 6c:  1::708 or 1::1.2.3.4
1072                                         */
1073        case 'i':                       /* Contiguous:
1074                                         * 4:   001.002.003.004
1075                                         * 6:   000102...0f
1076                                         */
1077                switch (fmt[1]) {
1078                case '6':
1079                        return ip6_addr_string(buf, end, ptr, spec, fmt);
1080                case '4':
1081                        return ip4_addr_string(buf, end, ptr, spec, fmt);
1082                }
1083                break;
1084        case 'U':
1085                return uuid_string(buf, end, ptr, spec, fmt);
1086        case 'V':
1087                {
1088                        va_list va;
1089
1090                        va_copy(va, *((struct va_format *)ptr)->va);
1091                        buf += vsnprintf(buf, end > buf ? end - buf : 0,
1092                                         ((struct va_format *)ptr)->fmt, va);
1093                        va_end(va);
1094                        return buf;
1095                }
1096        case 'K':
1097                /*
1098                 * %pK cannot be used in IRQ context because its test
1099                 * for CAP_SYSLOG would be meaningless.
1100                 */
1101                if (kptr_restrict && (in_irq() || in_serving_softirq() ||
1102                                      in_nmi())) {
1103                        if (spec.field_width == -1)
1104                                spec.field_width = default_width;
1105                        return string(buf, end, "pK-error", spec);
1106                }
1107                if (!((kptr_restrict == 0) ||
1108                      (kptr_restrict == 1 &&
1109                       has_capability_noaudit(current, CAP_SYSLOG))))
1110                        ptr = NULL;
1111                break;
1112        case 'N':
1113                switch (fmt[1]) {
1114                case 'F':
1115                        return netdev_feature_string(buf, end, ptr, spec);
1116                }
1117                break;
1118        }
1119        spec.flags |= SMALL;
1120        if (spec.field_width == -1) {
1121                spec.field_width = default_width;
1122                spec.flags |= ZEROPAD;
1123        }
1124        spec.base = 16;
1125
1126        return number(buf, end, (unsigned long) ptr, spec);
1127}
1128
1129/*
1130 * Helper function to decode printf style format.
1131 * Each call decode a token from the format and return the
1132 * number of characters read (or likely the delta where it wants
1133 * to go on the next call).
1134 * The decoded token is returned through the parameters
1135 *
1136 * 'h', 'l', or 'L' for integer fields
1137 * 'z' support added 23/7/1999 S.H.
1138 * 'z' changed to 'Z' --davidm 1/25/99
1139 * 't' added for ptrdiff_t
1140 *
1141 * @fmt: the format string
1142 * @type of the token returned
1143 * @flags: various flags such as +, -, # tokens..
1144 * @field_width: overwritten width
1145 * @base: base of the number (octal, hex, ...)
1146 * @precision: precision of a number
1147 * @qualifier: qualifier of a number (long, size_t, ...)
1148 */
1149static noinline_for_stack
1150int format_decode(const char *fmt, struct printf_spec *spec)
1151{
1152        const char *start = fmt;
1153
1154        /* we finished early by reading the field width */
1155        if (spec->type == FORMAT_TYPE_WIDTH) {
1156                if (spec->field_width < 0) {
1157                        spec->field_width = -spec->field_width;
1158                        spec->flags |= LEFT;
1159                }
1160                spec->type = FORMAT_TYPE_NONE;
1161                goto precision;
1162        }
1163
1164        /* we finished early by reading the precision */
1165        if (spec->type == FORMAT_TYPE_PRECISION) {
1166                if (spec->precision < 0)
1167                        spec->precision = 0;
1168
1169                spec->type = FORMAT_TYPE_NONE;
1170                goto qualifier;
1171        }
1172
1173        /* By default */
1174        spec->type = FORMAT_TYPE_NONE;
1175
1176        for (; *fmt ; ++fmt) {
1177                if (*fmt == '%')
1178                        break;
1179        }
1180
1181        /* Return the current non-format string */
1182        if (fmt != start || !*fmt)
1183                return fmt - start;
1184
1185        /* Process flags */
1186        spec->flags = 0;
1187
1188        while (1) { /* this also skips first '%' */
1189                bool found = true;
1190
1191                ++fmt;
1192
1193                switch (*fmt) {
1194                case '-': spec->flags |= LEFT;    break;
1195                case '+': spec->flags |= PLUS;    break;
1196                case ' ': spec->flags |= SPACE;   break;
1197                case '#': spec->flags |= SPECIAL; break;
1198                case '0': spec->flags |= ZEROPAD; break;
1199                default:  found = false;
1200                }
1201
1202                if (!found)
1203                        break;
1204        }
1205
1206        /* get field width */
1207        spec->field_width = -1;
1208
1209        if (isdigit(*fmt))
1210                spec->field_width = skip_atoi(&fmt);
1211        else if (*fmt == '*') {
1212                /* it's the next argument */
1213                spec->type = FORMAT_TYPE_WIDTH;
1214                return ++fmt - start;
1215        }
1216
1217precision:
1218        /* get the precision */
1219        spec->precision = -1;
1220        if (*fmt == '.') {
1221                ++fmt;
1222                if (isdigit(*fmt)) {
1223                        spec->precision = skip_atoi(&fmt);
1224                        if (spec->precision < 0)
1225                                spec->precision = 0;
1226                } else if (*fmt == '*') {
1227                        /* it's the next argument */
1228                        spec->type = FORMAT_TYPE_PRECISION;
1229                        return ++fmt - start;
1230                }
1231        }
1232
1233qualifier:
1234        /* get the conversion qualifier */
1235        spec->qualifier = -1;
1236        if (*fmt == 'h' || _tolower(*fmt) == 'l' ||
1237            _tolower(*fmt) == 'z' || *fmt == 't') {
1238                spec->qualifier = *fmt++;
1239                if (unlikely(spec->qualifier == *fmt)) {
1240                        if (spec->qualifier == 'l') {
1241                                spec->qualifier = 'L';
1242                                ++fmt;
1243                        } else if (spec->qualifier == 'h') {
1244                                spec->qualifier = 'H';
1245                                ++fmt;
1246                        }
1247                }
1248        }
1249
1250        /* default base */
1251        spec->base = 10;
1252        switch (*fmt) {
1253        case 'c':
1254                spec->type = FORMAT_TYPE_CHAR;
1255                return ++fmt - start;
1256
1257        case 's':
1258                spec->type = FORMAT_TYPE_STR;
1259                return ++fmt - start;
1260
1261        case 'p':
1262                spec->type = FORMAT_TYPE_PTR;
1263                return fmt - start;
1264                /* skip alnum */
1265
1266        case 'n':
1267                spec->type = FORMAT_TYPE_NRCHARS;
1268                return ++fmt - start;
1269
1270        case '%':
1271                spec->type = FORMAT_TYPE_PERCENT_CHAR;
1272                return ++fmt - start;
1273
1274        /* integer number formats - set up the flags and "break" */
1275        case 'o':
1276                spec->base = 8;
1277                break;
1278
1279        case 'x':
1280                spec->flags |= SMALL;
1281
1282        case 'X':
1283                spec->base = 16;
1284                break;
1285
1286        case 'd':
1287        case 'i':
1288                spec->flags |= SIGN;
1289        case 'u':
1290                break;
1291
1292        default:
1293                spec->type = FORMAT_TYPE_INVALID;
1294                return fmt - start;
1295        }
1296
1297        if (spec->qualifier == 'L')
1298                spec->type = FORMAT_TYPE_LONG_LONG;
1299        else if (spec->qualifier == 'l') {
1300                if (spec->flags & SIGN)
1301                        spec->type = FORMAT_TYPE_LONG;
1302                else
1303                        spec->type = FORMAT_TYPE_ULONG;
1304        } else if (_tolower(spec->qualifier) == 'z') {
1305                spec->type = FORMAT_TYPE_SIZE_T;
1306        } else if (spec->qualifier == 't') {
1307                spec->type = FORMAT_TYPE_PTRDIFF;
1308        } else if (spec->qualifier == 'H') {
1309                if (spec->flags & SIGN)
1310                        spec->type = FORMAT_TYPE_BYTE;
1311                else
1312                        spec->type = FORMAT_TYPE_UBYTE;
1313        } else if (spec->qualifier == 'h') {
1314                if (spec->flags & SIGN)
1315                        spec->type = FORMAT_TYPE_SHORT;
1316                else
1317                        spec->type = FORMAT_TYPE_USHORT;
1318        } else {
1319                if (spec->flags & SIGN)
1320                        spec->type = FORMAT_TYPE_INT;
1321                else
1322                        spec->type = FORMAT_TYPE_UINT;
1323        }
1324
1325        return ++fmt - start;
1326}
1327
1328/**
1329 * vsnprintf - Format a string and place it in a buffer
1330 * @buf: The buffer to place the result into
1331 * @size: The size of the buffer, including the trailing null space
1332 * @fmt: The format string to use
1333 * @args: Arguments for the format string
1334 *
1335 * This function follows C99 vsnprintf, but has some extensions:
1336 * %pS output the name of a text symbol with offset
1337 * %ps output the name of a text symbol without offset
1338 * %pF output the name of a function pointer with its offset
1339 * %pf output the name of a function pointer without its offset
1340 * %pB output the name of a backtrace symbol with its offset
1341 * %pR output the address range in a struct resource with decoded flags
1342 * %pr output the address range in a struct resource with raw flags
1343 * %pM output a 6-byte MAC address with colons
1344 * %pm output a 6-byte MAC address without colons
1345 * %pI4 print an IPv4 address without leading zeros
1346 * %pi4 print an IPv4 address with leading zeros
1347 * %pI6 print an IPv6 address with colons
1348 * %pi6 print an IPv6 address without colons
1349 * %pI6c print an IPv6 address as specified by RFC 5952
1350 * %pU[bBlL] print a UUID/GUID in big or little endian using lower or upper
1351 *   case.
1352 * %*ph[CDN] a variable-length hex string with a separator (supports up to 64
1353 *           bytes of the input)
1354 * %n is ignored
1355 *
1356 * ** Please update Documentation/printk-formats.txt when making changes **
1357 *
1358 * The return value is the number of characters which would
1359 * be generated for the given input, excluding the trailing
1360 * '\0', as per ISO C99. If you want to have the exact
1361 * number of characters written into @buf as return value
1362 * (not including the trailing '\0'), use vscnprintf(). If the
1363 * return is greater than or equal to @size, the resulting
1364 * string is truncated.
1365 *
1366 * If you're not already dealing with a va_list consider using snprintf().
1367 */
1368int vsnprintf(char *buf, size_t size, const char *fmt, va_list args)
1369{
1370        unsigned long long num;
1371        char *str, *end;
1372        struct printf_spec spec = {0};
1373
1374        /* Reject out-of-range values early.  Large positive sizes are
1375           used for unknown buffer sizes. */
1376        if (WARN_ON_ONCE((int) size < 0))
1377                return 0;
1378
1379        str = buf;
1380        end = buf + size;
1381
1382        /* Make sure end is always >= buf */
1383        if (end < buf) {
1384                end = ((void *)-1);
1385                size = end - buf;
1386        }
1387
1388        while (*fmt) {
1389                const char *old_fmt = fmt;
1390                int read = format_decode(fmt, &spec);
1391
1392                fmt += read;
1393
1394                switch (spec.type) {
1395                case FORMAT_TYPE_NONE: {
1396                        int copy = read;
1397                        if (str < end) {
1398                                if (copy > end - str)
1399                                        copy = end - str;
1400                                memcpy(str, old_fmt, copy);
1401                        }
1402                        str += read;
1403                        break;
1404                }
1405
1406                case FORMAT_TYPE_WIDTH:
1407                        spec.field_width = va_arg(args, int);
1408                        break;
1409
1410                case FORMAT_TYPE_PRECISION:
1411                        spec.precision = va_arg(args, int);
1412                        break;
1413
1414                case FORMAT_TYPE_CHAR: {
1415                        char c;
1416
1417                        if (!(spec.flags & LEFT)) {
1418                                while (--spec.field_width > 0) {
1419                                        if (str < end)
1420                                                *str = ' ';
1421                                        ++str;
1422
1423                                }
1424                        }
1425                        c = (unsigned char) va_arg(args, int);
1426                        if (str < end)
1427                                *str = c;
1428                        ++str;
1429                        while (--spec.field_width > 0) {
1430                                if (str < end)
1431                                        *str = ' ';
1432                                ++str;
1433                        }
1434                        break;
1435                }
1436
1437                case FORMAT_TYPE_STR:
1438                        str = string(str, end, va_arg(args, char *), spec);
1439                        break;
1440
1441                case FORMAT_TYPE_PTR:
1442                        str = pointer(fmt+1, str, end, va_arg(args, void *),
1443                                      spec);
1444                        while (isalnum(*fmt))
1445                                fmt++;
1446                        break;
1447
1448                case FORMAT_TYPE_PERCENT_CHAR:
1449                        if (str < end)
1450                                *str = '%';
1451                        ++str;
1452                        break;
1453
1454                case FORMAT_TYPE_INVALID:
1455                        if (str < end)
1456                                *str = '%';
1457                        ++str;
1458                        break;
1459
1460                case FORMAT_TYPE_NRCHARS: {
1461                        u8 qualifier = spec.qualifier;
1462
1463                        if (qualifier == 'l') {
1464                                long *ip = va_arg(args, long *);
1465                                *ip = (str - buf);
1466                        } else if (_tolower(qualifier) == 'z') {
1467                                size_t *ip = va_arg(args, size_t *);
1468                                *ip = (str - buf);
1469                        } else {
1470                                int *ip = va_arg(args, int *);
1471                                *ip = (str - buf);
1472                        }
1473                        break;
1474                }
1475
1476                default:
1477                        switch (spec.type) {
1478                        case FORMAT_TYPE_LONG_LONG:
1479                                num = va_arg(args, long long);
1480                                break;
1481                        case FORMAT_TYPE_ULONG:
1482                                num = va_arg(args, unsigned long);
1483                                break;
1484                        case FORMAT_TYPE_LONG:
1485                                num = va_arg(args, long);
1486                                break;
1487                        case FORMAT_TYPE_SIZE_T:
1488                                num = va_arg(args, size_t);
1489                                break;
1490                        case FORMAT_TYPE_PTRDIFF:
1491                                num = va_arg(args, ptrdiff_t);
1492                                break;
1493                        case FORMAT_TYPE_UBYTE:
1494                                num = (unsigned char) va_arg(args, int);
1495                                break;
1496                        case FORMAT_TYPE_BYTE:
1497                                num = (signed char) va_arg(args, int);
1498                                break;
1499                        case FORMAT_TYPE_USHORT:
1500                                num = (unsigned short) va_arg(args, int);
1501                                break;
1502                        case FORMAT_TYPE_SHORT:
1503                                num = (short) va_arg(args, int);
1504                                break;
1505                        case FORMAT_TYPE_INT:
1506                                num = (int) va_arg(args, int);
1507                                break;
1508                        default:
1509                                num = va_arg(args, unsigned int);
1510                        }
1511
1512                        str = number(str, end, num, spec);
1513                }
1514        }
1515
1516        if (size > 0) {
1517                if (str < end)
1518                        *str = '\0';
1519                else
1520                        end[-1] = '\0';
1521        }
1522
1523        /* the trailing null byte doesn't count towards the total */
1524        return str-buf;
1525
1526}
1527EXPORT_SYMBOL(vsnprintf);
1528
1529/**
1530 * vscnprintf - Format a string and place it in a buffer
1531 * @buf: The buffer to place the result into
1532 * @size: The size of the buffer, including the trailing null space
1533 * @fmt: The format string to use
1534 * @args: Arguments for the format string
1535 *
1536 * The return value is the number of characters which have been written into
1537 * the @buf not including the trailing '\0'. If @size is == 0 the function
1538 * returns 0.
1539 *
1540 * If you're not already dealing with a va_list consider using scnprintf().
1541 *
1542 * See the vsnprintf() documentation for format string extensions over C99.
1543 */
1544int vscnprintf(char *buf, size_t size, const char *fmt, va_list args)
1545{
1546        int i;
1547
1548        i = vsnprintf(buf, size, fmt, args);
1549
1550        if (likely(i < size))
1551                return i;
1552        if (size != 0)
1553                return size - 1;
1554        return 0;
1555}
1556EXPORT_SYMBOL(vscnprintf);
1557
1558/**
1559 * snprintf - Format a string and place it in a buffer
1560 * @buf: The buffer to place the result into
1561 * @size: The size of the buffer, including the trailing null space
1562 * @fmt: The format string to use
1563 * @...: Arguments for the format string
1564 *
1565 * The return value is the number of characters which would be
1566 * generated for the given input, excluding the trailing null,
1567 * as per ISO C99.  If the return is greater than or equal to
1568 * @size, the resulting string is truncated.
1569 *
1570 * See the vsnprintf() documentation for format string extensions over C99.
1571 */
1572int snprintf(char *buf, size_t size, const char *fmt, ...)
1573{
1574        va_list args;
1575        int i;
1576
1577        va_start(args, fmt);
1578        i = vsnprintf(buf, size, fmt, args);
1579        va_end(args);
1580
1581        return i;
1582}
1583EXPORT_SYMBOL(snprintf);
1584
1585/**
1586 * scnprintf - Format a string and place it in a buffer
1587 * @buf: The buffer to place the result into
1588 * @size: The size of the buffer, including the trailing null space
1589 * @fmt: The format string to use
1590 * @...: Arguments for the format string
1591 *
1592 * The return value is the number of characters written into @buf not including
1593 * the trailing '\0'. If @size is == 0 the function returns 0.
1594 */
1595
1596int scnprintf(char *buf, size_t size, const char *fmt, ...)
1597{
1598        va_list args;
1599        int i;
1600
1601        va_start(args, fmt);
1602        i = vscnprintf(buf, size, fmt, args);
1603        va_end(args);
1604
1605        return i;
1606}
1607EXPORT_SYMBOL(scnprintf);
1608
1609/**
1610 * vsprintf - Format a string and place it in a buffer
1611 * @buf: The buffer to place the result into
1612 * @fmt: The format string to use
1613 * @args: Arguments for the format string
1614 *
1615 * The function returns the number of characters written
1616 * into @buf. Use vsnprintf() or vscnprintf() in order to avoid
1617 * buffer overflows.
1618 *
1619 * If you're not already dealing with a va_list consider using sprintf().
1620 *
1621 * See the vsnprintf() documentation for format string extensions over C99.
1622 */
1623int vsprintf(char *buf, const char *fmt, va_list args)
1624{
1625        return vsnprintf(buf, INT_MAX, fmt, args);
1626}
1627EXPORT_SYMBOL(vsprintf);
1628
1629/**
1630 * sprintf - Format a string and place it in a buffer
1631 * @buf: The buffer to place the result into
1632 * @fmt: The format string to use
1633 * @...: Arguments for the format string
1634 *
1635 * The function returns the number of characters written
1636 * into @buf. Use snprintf() or scnprintf() in order to avoid
1637 * buffer overflows.
1638 *
1639 * See the vsnprintf() documentation for format string extensions over C99.
1640 */
1641int sprintf(char *buf, const char *fmt, ...)
1642{
1643        va_list args;
1644        int i;
1645
1646        va_start(args, fmt);
1647        i = vsnprintf(buf, INT_MAX, fmt, args);
1648        va_end(args);
1649
1650        return i;
1651}
1652EXPORT_SYMBOL(sprintf);
1653
1654#ifdef CONFIG_BINARY_PRINTF
1655/*
1656 * bprintf service:
1657 * vbin_printf() - VA arguments to binary data
1658 * bstr_printf() - Binary data to text string
1659 */
1660
1661/**
1662 * vbin_printf - Parse a format string and place args' binary value in a buffer
1663 * @bin_buf: The buffer to place args' binary value
1664 * @size: The size of the buffer(by words(32bits), not characters)
1665 * @fmt: The format string to use
1666 * @args: Arguments for the format string
1667 *
1668 * The format follows C99 vsnprintf, except %n is ignored, and its argument
1669 * is skiped.
1670 *
1671 * The return value is the number of words(32bits) which would be generated for
1672 * the given input.
1673 *
1674 * NOTE:
1675 * If the return value is greater than @size, the resulting bin_buf is NOT
1676 * valid for bstr_printf().
1677 */
1678int vbin_printf(u32 *bin_buf, size_t size, const char *fmt, va_list args)
1679{
1680        struct printf_spec spec = {0};
1681        char *str, *end;
1682
1683        str = (char *)bin_buf;
1684        end = (char *)(bin_buf + size);
1685
1686#define save_arg(type)                                                  \
1687do {                                                                    \
1688        if (sizeof(type) == 8) {                                        \
1689                unsigned long long value;                               \
1690                str = PTR_ALIGN(str, sizeof(u32));                      \
1691                value = va_arg(args, unsigned long long);               \
1692                if (str + sizeof(type) <= end) {                        \
1693                        *(u32 *)str = *(u32 *)&value;                   \
1694                        *(u32 *)(str + 4) = *((u32 *)&value + 1);       \
1695                }                                                       \
1696        } else {                                                        \
1697                unsigned long value;                                    \
1698                str = PTR_ALIGN(str, sizeof(type));                     \
1699                value = va_arg(args, int);                              \
1700                if (str + sizeof(type) <= end)                          \
1701                        *(typeof(type) *)str = (type)value;             \
1702        }                                                               \
1703        str += sizeof(type);                                            \
1704} while (0)
1705
1706        while (*fmt) {
1707                int read = format_decode(fmt, &spec);
1708
1709                fmt += read;
1710
1711                switch (spec.type) {
1712                case FORMAT_TYPE_NONE:
1713                case FORMAT_TYPE_INVALID:
1714                case FORMAT_TYPE_PERCENT_CHAR:
1715                        break;
1716
1717                case FORMAT_TYPE_WIDTH:
1718                case FORMAT_TYPE_PRECISION:
1719                        save_arg(int);
1720                        break;
1721
1722                case FORMAT_TYPE_CHAR:
1723                        save_arg(char);
1724                        break;
1725
1726                case FORMAT_TYPE_STR: {
1727                        const char *save_str = va_arg(args, char *);
1728                        size_t len;
1729
1730                        if ((unsigned long)save_str > (unsigned long)-PAGE_SIZE
1731                                        || (unsigned long)save_str < PAGE_SIZE)
1732                                save_str = "(null)";
1733                        len = strlen(save_str) + 1;
1734                        if (str + len < end)
1735                                memcpy(str, save_str, len);
1736                        str += len;
1737                        break;
1738                }
1739
1740                case FORMAT_TYPE_PTR:
1741                        save_arg(void *);
1742                        /* skip all alphanumeric pointer suffixes */
1743                        while (isalnum(*fmt))
1744                                fmt++;
1745                        break;
1746
1747                case FORMAT_TYPE_NRCHARS: {
1748                        /* skip %n 's argument */
1749                        u8 qualifier = spec.qualifier;
1750                        void *skip_arg;
1751                        if (qualifier == 'l')
1752                                skip_arg = va_arg(args, long *);
1753                        else if (_tolower(qualifier) == 'z')
1754                                skip_arg = va_arg(args, size_t *);
1755                        else
1756                                skip_arg = va_arg(args, int *);
1757                        break;
1758                }
1759
1760                default:
1761                        switch (spec.type) {
1762
1763                        case FORMAT_TYPE_LONG_LONG:
1764                                save_arg(long long);
1765                                break;
1766                        case FORMAT_TYPE_ULONG:
1767                        case FORMAT_TYPE_LONG:
1768                                save_arg(unsigned long);
1769                                break;
1770                        case FORMAT_TYPE_SIZE_T:
1771                                save_arg(size_t);
1772                                break;
1773                        case FORMAT_TYPE_PTRDIFF:
1774                                save_arg(ptrdiff_t);
1775                                break;
1776                        case FORMAT_TYPE_UBYTE:
1777                        case FORMAT_TYPE_BYTE:
1778                                save_arg(char);
1779                                break;
1780                        case FORMAT_TYPE_USHORT:
1781                        case FORMAT_TYPE_SHORT:
1782                                save_arg(short);
1783                                break;
1784                        default:
1785                                save_arg(int);
1786                        }
1787                }
1788        }
1789
1790        return (u32 *)(PTR_ALIGN(str, sizeof(u32))) - bin_buf;
1791#undef save_arg
1792}
1793EXPORT_SYMBOL_GPL(vbin_printf);
1794
1795/**
1796 * bstr_printf - Format a string from binary arguments and place it in a buffer
1797 * @buf: The buffer to place the result into
1798 * @size: The size of the buffer, including the trailing null space
1799 * @fmt: The format string to use
1800 * @bin_buf: Binary arguments for the format string
1801 *
1802 * This function like C99 vsnprintf, but the difference is that vsnprintf gets
1803 * arguments from stack, and bstr_printf gets arguments from @bin_buf which is
1804 * a binary buffer that generated by vbin_printf.
1805 *
1806 * The format follows C99 vsnprintf, but has some extensions:
1807 *  see vsnprintf comment for details.
1808 *
1809 * The return value is the number of characters which would
1810 * be generated for the given input, excluding the trailing
1811 * '\0', as per ISO C99. If you want to have the exact
1812 * number of characters written into @buf as return value
1813 * (not including the trailing '\0'), use vscnprintf(). If the
1814 * return is greater than or equal to @size, the resulting
1815 * string is truncated.
1816 */
1817int bstr_printf(char *buf, size_t size, const char *fmt, const u32 *bin_buf)
1818{
1819        struct printf_spec spec = {0};
1820        char *str, *end;
1821        const char *args = (const char *)bin_buf;
1822
1823        if (WARN_ON_ONCE((int) size < 0))
1824                return 0;
1825
1826        str = buf;
1827        end = buf + size;
1828
1829#define get_arg(type)                                                   \
1830({                                                                      \
1831        typeof(type) value;                                             \
1832        if (sizeof(type) == 8) {                                        \
1833                args = PTR_ALIGN(args, sizeof(u32));                    \
1834                *(u32 *)&value = *(u32 *)args;                          \
1835                *((u32 *)&value + 1) = *(u32 *)(args + 4);              \
1836        } else {                                                        \
1837                args = PTR_ALIGN(args, sizeof(type));                   \
1838                value = *(typeof(type) *)args;                          \
1839        }                                                               \
1840        args += sizeof(type);                                           \
1841        value;                                                          \
1842})
1843
1844        /* Make sure end is always >= buf */
1845        if (end < buf) {
1846                end = ((void *)-1);
1847                size = end - buf;
1848        }
1849
1850        while (*fmt) {
1851                const char *old_fmt = fmt;
1852                int read = format_decode(fmt, &spec);
1853
1854                fmt += read;
1855
1856                switch (spec.type) {
1857                case FORMAT_TYPE_NONE: {
1858                        int copy = read;
1859                        if (str < end) {
1860                                if (copy > end - str)
1861                                        copy = end - str;
1862                                memcpy(str, old_fmt, copy);
1863                        }
1864                        str += read;
1865                        break;
1866                }
1867
1868                case FORMAT_TYPE_WIDTH:
1869                        spec.field_width = get_arg(int);
1870                        break;
1871
1872                case FORMAT_TYPE_PRECISION:
1873                        spec.precision = get_arg(int);
1874                        break;
1875
1876                case FORMAT_TYPE_CHAR: {
1877                        char c;
1878
1879                        if (!(spec.flags & LEFT)) {
1880                                while (--spec.field_width > 0) {
1881                                        if (str < end)
1882                                                *str = ' ';
1883                                        ++str;
1884                                }
1885                        }
1886                        c = (unsigned char) get_arg(char);
1887                        if (str < end)
1888                                *str = c;
1889                        ++str;
1890                        while (--spec.field_width > 0) {
1891                                if (str < end)
1892                                        *str = ' ';
1893                                ++str;
1894                        }
1895                        break;
1896                }
1897
1898                case FORMAT_TYPE_STR: {
1899                        const char *str_arg = args;
1900                        args += strlen(str_arg) + 1;
1901                        str = string(str, end, (char *)str_arg, spec);
1902                        break;
1903                }
1904
1905                case FORMAT_TYPE_PTR:
1906                        str = pointer(fmt+1, str, end, get_arg(void *), spec);
1907                        while (isalnum(*fmt))
1908                                fmt++;
1909                        break;
1910
1911                case FORMAT_TYPE_PERCENT_CHAR:
1912                case FORMAT_TYPE_INVALID:
1913                        if (str < end)
1914                                *str = '%';
1915                        ++str;
1916                        break;
1917
1918                case FORMAT_TYPE_NRCHARS:
1919                        /* skip */
1920                        break;
1921
1922                default: {
1923                        unsigned long long num;
1924
1925                        switch (spec.type) {
1926
1927                        case FORMAT_TYPE_LONG_LONG:
1928                                num = get_arg(long long);
1929                                break;
1930                        case FORMAT_TYPE_ULONG:
1931                        case FORMAT_TYPE_LONG:
1932                                num = get_arg(unsigned long);
1933                                break;
1934                        case FORMAT_TYPE_SIZE_T:
1935                                num = get_arg(size_t);
1936                                break;
1937                        case FORMAT_TYPE_PTRDIFF:
1938                                num = get_arg(ptrdiff_t);
1939                                break;
1940                        case FORMAT_TYPE_UBYTE:
1941                                num = get_arg(unsigned char);
1942                                break;
1943                        case FORMAT_TYPE_BYTE:
1944                                num = get_arg(signed char);
1945                                break;
1946                        case FORMAT_TYPE_USHORT:
1947                                num = get_arg(unsigned short);
1948                                break;
1949                        case FORMAT_TYPE_SHORT:
1950                                num = get_arg(short);
1951                                break;
1952                        case FORMAT_TYPE_UINT:
1953                                num = get_arg(unsigned int);
1954                                break;
1955                        default:
1956                                num = get_arg(int);
1957                        }
1958
1959                        str = number(str, end, num, spec);
1960                } /* default: */
1961                } /* switch(spec.type) */
1962        } /* while(*fmt) */
1963
1964        if (size > 0) {
1965                if (str < end)
1966                        *str = '\0';
1967                else
1968                        end[-1] = '\0';
1969        }
1970
1971#undef get_arg
1972
1973        /* the trailing null byte doesn't count towards the total */
1974        return str - buf;
1975}
1976EXPORT_SYMBOL_GPL(bstr_printf);
1977
1978/**
1979 * bprintf - Parse a format string and place args' binary value in a buffer
1980 * @bin_buf: The buffer to place args' binary value
1981 * @size: The size of the buffer(by words(32bits), not characters)
1982 * @fmt: The format string to use
1983 * @...: Arguments for the format string
1984 *
1985 * The function returns the number of words(u32) written
1986 * into @bin_buf.
1987 */
1988int bprintf(u32 *bin_buf, size_t size, const char *fmt, ...)
1989{
1990        va_list args;
1991        int ret;
1992
1993        va_start(args, fmt);
1994        ret = vbin_printf(bin_buf, size, fmt, args);
1995        va_end(args);
1996
1997        return ret;
1998}
1999EXPORT_SYMBOL_GPL(bprintf);
2000
2001#endif /* CONFIG_BINARY_PRINTF */
2002
2003/**
2004 * vsscanf - Unformat a buffer into a list of arguments
2005 * @buf:        input buffer
2006 * @fmt:        format of buffer
2007 * @args:       arguments
2008 */
2009int vsscanf(const char *buf, const char *fmt, va_list args)
2010{
2011        const char *str = buf;
2012        char *next;
2013        char digit;
2014        int num = 0;
2015        u8 qualifier;
2016        u8 base;
2017        s16 field_width;
2018        bool is_sign;
2019
2020        while (*fmt && *str) {
2021                /* skip any white space in format */
2022                /* white space in format matchs any amount of
2023                 * white space, including none, in the input.
2024                 */
2025                if (isspace(*fmt)) {
2026                        fmt = skip_spaces(++fmt);
2027                        str = skip_spaces(str);
2028                }
2029
2030                /* anything that is not a conversion must match exactly */
2031                if (*fmt != '%' && *fmt) {
2032                        if (*fmt++ != *str++)
2033                                break;
2034                        continue;
2035                }
2036
2037                if (!*fmt)
2038                        break;
2039                ++fmt;
2040
2041                /* skip this conversion.
2042                 * advance both strings to next white space
2043                 */
2044                if (*fmt == '*') {
2045                        while (!isspace(*fmt) && *fmt != '%' && *fmt)
2046                                fmt++;
2047                        while (!isspace(*str) && *str)
2048                                str++;
2049                        continue;
2050                }
2051
2052                /* get field width */
2053                field_width = -1;
2054                if (isdigit(*fmt))
2055                        field_width = skip_atoi(&fmt);
2056
2057                /* get conversion qualifier */
2058                qualifier = -1;
2059                if (*fmt == 'h' || _tolower(*fmt) == 'l' ||
2060                    _tolower(*fmt) == 'z') {
2061                        qualifier = *fmt++;
2062                        if (unlikely(qualifier == *fmt)) {
2063                                if (qualifier == 'h') {
2064                                        qualifier = 'H';
2065                                        fmt++;
2066                                } else if (qualifier == 'l') {
2067                                        qualifier = 'L';
2068                                        fmt++;
2069                                }
2070                        }
2071                }
2072
2073                if (!*fmt || !*str)
2074                        break;
2075
2076                base = 10;
2077                is_sign = 0;
2078
2079                switch (*fmt++) {
2080                case 'c':
2081                {
2082                        char *s = (char *)va_arg(args, char*);
2083                        if (field_width == -1)
2084                                field_width = 1;
2085                        do {
2086                                *s++ = *str++;
2087                        } while (--field_width > 0 && *str);
2088                        num++;
2089                }
2090                continue;
2091                case 's':
2092                {
2093                        char *s = (char *)va_arg(args, char *);
2094                        if (field_width == -1)
2095                                field_width = SHRT_MAX;
2096                        /* first, skip leading white space in buffer */
2097                        str = skip_spaces(str);
2098
2099                        /* now copy until next white space */
2100                        while (*str && !isspace(*str) && field_width--)
2101                                *s++ = *str++;
2102                        *s = '\0';
2103                        num++;
2104                }
2105                continue;
2106                case 'n':
2107                        /* return number of characters read so far */
2108                {
2109                        int *i = (int *)va_arg(args, int*);
2110                        *i = str - buf;
2111                }
2112                continue;
2113                case 'o':
2114                        base = 8;
2115                        break;
2116                case 'x':
2117                case 'X':
2118                        base = 16;
2119                        break;
2120                case 'i':
2121                        base = 0;
2122                case 'd':
2123                        is_sign = 1;
2124                case 'u':
2125                        break;
2126                case '%':
2127                        /* looking for '%' in str */
2128                        if (*str++ != '%')
2129                                return num;
2130                        continue;
2131                default:
2132                        /* invalid format; stop here */
2133                        return num;
2134                }
2135
2136                /* have some sort of integer conversion.
2137                 * first, skip white space in buffer.
2138                 */
2139                str = skip_spaces(str);
2140
2141                digit = *str;
2142                if (is_sign && digit == '-')
2143                        digit = *(str + 1);
2144
2145                if (!digit
2146                    || (base == 16 && !isxdigit(digit))
2147                    || (base == 10 && !isdigit(digit))
2148                    || (base == 8 && (!isdigit(digit) || digit > '7'))
2149                    || (base == 0 && !isdigit(digit)))
2150                        break;
2151
2152                switch (qualifier) {
2153                case 'H':       /* that's 'hh' in format */
2154                        if (is_sign) {
2155                                signed char *s = (signed char *)va_arg(args, signed char *);
2156                                *s = (signed char)simple_strtol(str, &next, base);
2157                        } else {
2158                                unsigned char *s = (unsigned char *)va_arg(args, unsigned char *);
2159                                *s = (unsigned char)simple_strtoul(str, &next, base);
2160                        }
2161                        break;
2162                case 'h':
2163                        if (is_sign) {
2164                                short *s = (short *)va_arg(args, short *);
2165                                *s = (short)simple_strtol(str, &next, base);
2166                        } else {
2167                                unsigned short *s = (unsigned short *)va_arg(args, unsigned short *);
2168                                *s = (unsigned short)simple_strtoul(str, &next, base);
2169                        }
2170                        break;
2171                case 'l':
2172                        if (is_sign) {
2173                                long *l = (long *)va_arg(args, long *);
2174                                *l = simple_strtol(str, &next, base);
2175                        } else {
2176                                unsigned long *l = (unsigned long *)va_arg(args, unsigned long *);
2177                                *l = simple_strtoul(str, &next, base);
2178                        }
2179                        break;
2180                case 'L':
2181                        if (is_sign) {
2182                                long long *l = (long long *)va_arg(args, long long *);
2183                                *l = simple_strtoll(str, &next, base);
2184                        } else {
2185                                unsigned long long *l = (unsigned long long *)va_arg(args, unsigned long long *);
2186                                *l = simple_strtoull(str, &next, base);
2187                        }
2188                        break;
2189                case 'Z':
2190                case 'z':
2191                {
2192                        size_t *s = (size_t *)va_arg(args, size_t *);
2193                        *s = (size_t)simple_strtoul(str, &next, base);
2194                }
2195                break;
2196                default:
2197                        if (is_sign) {
2198                                int *i = (int *)va_arg(args, int *);
2199                                *i = (int)simple_strtol(str, &next, base);
2200                        } else {
2201                                unsigned int *i = (unsigned int *)va_arg(args, unsigned int*);
2202                                *i = (unsigned int)simple_strtoul(str, &next, base);
2203                        }
2204                        break;
2205                }
2206                num++;
2207
2208                if (!next)
2209                        break;
2210                str = next;
2211        }
2212
2213        /*
2214         * Now we've come all the way through so either the input string or the
2215         * format ended. In the former case, there can be a %n at the current
2216         * position in the format that needs to be filled.
2217         */
2218        if (*fmt == '%' && *(fmt + 1) == 'n') {
2219                int *p = (int *)va_arg(args, int *);
2220                *p = str - buf;
2221        }
2222
2223        return num;
2224}
2225EXPORT_SYMBOL(vsscanf);
2226
2227/**
2228 * sscanf - Unformat a buffer into a list of arguments
2229 * @buf:        input buffer
2230 * @fmt:        formatting of buffer
2231 * @...:        resulting arguments
2232 */
2233int sscanf(const char *buf, const char *fmt, ...)
2234{
2235        va_list args;
2236        int i;
2237
2238        va_start(args, fmt);
2239        i = vsscanf(buf, fmt, args);
2240        va_end(args);
2241
2242        return i;
2243}
2244EXPORT_SYMBOL(sscanf);
2245
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