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        while (r >= 10000) {
 178                q = r + '0';
 179                r  = (r * (uint64_t)0x1999999a) >> 32;
 180                *buf++ = q - 10*r;
 181        }
 182
 183        q      = (r * 0x199a) >> 16;    /* r <= 9999 */
 184        *buf++ = (r - 10 * q)  + '0';
 185        if (q == 0)
 186                return buf;
 187        r      = (q * 0xcd) >> 11;      /* q <= 999 */
 188        *buf++ = (q - 10 * r)  + '0';
 189        if (r == 0)
 190                return buf;
 191        q      = (r * 0xcd) >> 11;      /* r <= 99 */
 192        *buf++ = (r - 10 * q) + '0';
 193        if (q == 0)
 194                return buf;
 195        *buf++ = q + '0';                /* q <= 9 */
 196        return buf;
 197}
 198
 199/* There are two algorithms to print larger numbers.
 200 * One is generic: divide by 1000000000 and repeatedly print
 201 * groups of (up to) 9 digits. It's conceptually simple,
 202 * but requires a (unsigned long long) / 1000000000 division.
 203 *
 204 * Second algorithm splits 64-bit unsigned long long into 16-bit chunks,
 205 * manipulates them cleverly and generates groups of 4 decimal digits.
 206 * It so happens that it does NOT require long long division.
 207 *
 208 * If long is > 32 bits, division of 64-bit values is relatively easy,
 209 * and we will use the first algorithm.
 210 * If long long is > 64 bits (strange architecture with VERY large long long),
 211 * second algorithm can't be used, and we again use the first one.
 212 *
 213 * Else (if long is 32 bits and long long is 64 bits) we use second one.
 214 */
 215
 216#if BITS_PER_LONG != 32 || BITS_PER_LONG_LONG != 64
 217
 218/* First algorithm: generic */
 219
 220static
 221char *put_dec(char *buf, unsigned long long n)
 222{
 223        if (n >= 100*1000*1000) {
 224                while (n >= 1000*1000*1000)
 225                        buf = put_dec_full9(buf, do_div(n, 1000*1000*1000));
 226                if (n >= 100*1000*1000)
 227                        return put_dec_full9(buf, n);
 228        }
 229        return put_dec_trunc8(buf, n);
 230}
 231
 232#else
 233
 234/* Second algorithm: valid only for 64-bit long longs */
 235
 236/* See comment in put_dec_full9 for choice of constants */
 237static noinline_for_stack
 238void put_dec_full4(char *buf, unsigned q)
 239{
 240        unsigned r;
 241        r      = (q * 0xccd) >> 15;
 242        buf[0] = (q - 10 * r) + '0';
 243        q      = (r * 0xcd) >> 11;
 244        buf[1] = (r - 10 * q)  + '0';
 245        r      = (q * 0xcd) >> 11;
 246        buf[2] = (q - 10 * r)  + '0';
 247        buf[3] = r + '0';
 248}
 249
 250/*
 251 * Call put_dec_full4 on x % 10000, return x / 10000.
 252 * The approximation x/10000 == (x * 0x346DC5D7) >> 43
 253 * holds for all x < 1,128,869,999.  The largest value this
 254 * helper will ever be asked to convert is 1,125,520,955.
 255 * (d1 in the put_dec code, assuming n is all-ones).
 256 */
 257static
 258unsigned put_dec_helper4(char *buf, unsigned x)
 259{
 260        uint32_t q = (x * (uint64_t)0x346DC5D7) >> 43;
 261
 262        put_dec_full4(buf, x - q * 10000);
 263        return q;
 264}
 265
 266/* Based on code by Douglas W. Jones found at
 267 * <http://www.cs.uiowa.edu/~jones/bcd/decimal.html#sixtyfour>
 268 * (with permission from the author).
 269 * Performs no 64-bit division and hence should be fast on 32-bit machines.
 270 */
 271static
 272char *put_dec(char *buf, unsigned long long n)
 273{
 274        uint32_t d3, d2, d1, q, h;
 275
 276        if (n < 100*1000*1000)
 277                return put_dec_trunc8(buf, n);
 278
 279        d1  = ((uint32_t)n >> 16); /* implicit "& 0xffff" */
 280        h   = (n >> 32);
 281        d2  = (h      ) & 0xffff;
 282        d3  = (h >> 16); /* implicit "& 0xffff" */
 283
 284        q   = 656 * d3 + 7296 * d2 + 5536 * d1 + ((uint32_t)n & 0xffff);
 285        q = put_dec_helper4(buf, q);
 286
 287        q += 7671 * d3 + 9496 * d2 + 6 * d1;
 288        q = put_dec_helper4(buf+4, q);
 289
 290        q += 4749 * d3 + 42 * d2;
 291        q = put_dec_helper4(buf+8, q);
 292
 293        q += 281 * d3;
 294        buf += 12;
 295        if (q)
 296                buf = put_dec_trunc8(buf, q);
 297        else while (buf[-1] == '0')
 298                --buf;
 299
 300        return buf;
 301}
 302
 303#endif
 304
 305/*
 306 * Convert passed number to decimal string.
 307 * Returns the length of string.  On buffer overflow, returns 0.
 308 *
 309 * If speed is not important, use snprintf(). It's easy to read the code.
 310 */
 311int num_to_str(char *buf, int size, unsigned long long num)
 312{
 313        char tmp[sizeof(num) * 3];
 314        int idx, len;
 315
 316        /* put_dec() may work incorrectly for num = 0 (generate "", not "0") */
 317        if (num <= 9) {
 318                tmp[0] = '0' + num;
 319                len = 1;
 320        } else {
 321                len = put_dec(tmp, num) - tmp;
 322        }
 323
 324        if (len > size)
 325                return 0;
 326        for (idx = 0; idx < len; ++idx)
 327                buf[idx] = tmp[len - idx - 1];
 328        return len;
 329}
 330
 331#define ZEROPAD 1               /* pad with zero */
 332#define SIGN    2               /* unsigned/signed long */
 333#define PLUS    4               /* show plus */
 334#define SPACE   8               /* space if plus */
 335#define LEFT    16              /* left justified */
 336#define SMALL   32              /* use lowercase in hex (must be 32 == 0x20) */
 337#define SPECIAL 64              /* prefix hex with "0x", octal with "0" */
 338
 339enum format_type {
 340        FORMAT_TYPE_NONE, /* Just a string part */
 341        FORMAT_TYPE_WIDTH,
 342        FORMAT_TYPE_PRECISION,
 343        FORMAT_TYPE_CHAR,
 344        FORMAT_TYPE_STR,
 345        FORMAT_TYPE_PTR,
 346        FORMAT_TYPE_PERCENT_CHAR,
 347        FORMAT_TYPE_INVALID,
 348        FORMAT_TYPE_LONG_LONG,
 349        FORMAT_TYPE_ULONG,
 350        FORMAT_TYPE_LONG,
 351        FORMAT_TYPE_UBYTE,
 352        FORMAT_TYPE_BYTE,
 353        FORMAT_TYPE_USHORT,
 354        FORMAT_TYPE_SHORT,
 355        FORMAT_TYPE_UINT,
 356        FORMAT_TYPE_INT,
 357        FORMAT_TYPE_NRCHARS,
 358        FORMAT_TYPE_SIZE_T,
 359        FORMAT_TYPE_PTRDIFF
 360};
 361
 362struct printf_spec {
 363        u8      type;           /* format_type enum */
 364        u8      flags;          /* flags to number() */
 365        u8      base;           /* number base, 8, 10 or 16 only */
 366        u8      qualifier;      /* number qualifier, one of 'hHlLtzZ' */
 367        s16     field_width;    /* width of output field */
 368        s16     precision;      /* # of digits/chars */
 369};
 370
 371static noinline_for_stack
 372char *number(char *buf, char *end, unsigned long long num,
 373             struct printf_spec spec)
 374{
 375        /* we are called with base 8, 10 or 16, only, thus don't need "G..."  */
 376        static const char digits[16] = "0123456789ABCDEF"; /* "GHIJKLMNOPQRSTUVWXYZ"; */
 377
 378        char tmp[66];
 379        char sign;
 380        char locase;
 381        int need_pfx = ((spec.flags & SPECIAL) && spec.base != 10);
 382        int i;
 383        bool is_zero = num == 0LL;
 384
 385        /* locase = 0 or 0x20. ORing digits or letters with 'locase'
 386         * produces same digits or (maybe lowercased) letters */
 387        locase = (spec.flags & SMALL);
 388        if (spec.flags & LEFT)
 389                spec.flags &= ~ZEROPAD;
 390        sign = 0;
 391        if (spec.flags & SIGN) {
 392                if ((signed long long)num < 0) {
 393                        sign = '-';
 394                        num = -(signed long long)num;
 395                        spec.field_width--;
 396                } else if (spec.flags & PLUS) {
 397                        sign = '+';
 398                        spec.field_width--;
 399                } else if (spec.flags & SPACE) {
 400                        sign = ' ';
 401                        spec.field_width--;
 402                }
 403        }
 404        if (need_pfx) {
 405                if (spec.base == 16)
 406                        spec.field_width -= 2;
 407                else if (!is_zero)
 408                        spec.field_width--;
 409        }
 410
 411        /* generate full string in tmp[], in reverse order */
 412        i = 0;
 413        if (num < spec.base)
 414                tmp[i++] = digits[num] | locase;
 415        /* Generic code, for any base:
 416        else do {
 417                tmp[i++] = (digits[do_div(num,base)] | locase);
 418        } while (num != 0);
 419        */
 420        else if (spec.base != 10) { /* 8 or 16 */
 421                int mask = spec.base - 1;
 422                int shift = 3;
 423
 424                if (spec.base == 16)
 425                        shift = 4;
 426                do {
 427                        tmp[i++] = (digits[((unsigned char)num) & mask] | locase);
 428                        num >>= shift;
 429                } while (num);
 430        } else { /* base 10 */
 431                i = put_dec(tmp, num) - tmp;
 432        }
 433
 434        /* printing 100 using %2d gives "100", not "00" */
 435        if (i > spec.precision)
 436                spec.precision = i;
 437        /* leading space padding */
 438        spec.field_width -= spec.precision;
 439        if (!(spec.flags & (ZEROPAD+LEFT))) {
 440                while (--spec.field_width >= 0) {
 441                        if (buf < end)
 442                                *buf = ' ';
 443                        ++buf;
 444                }
 445        }
 446        /* sign */
 447        if (sign) {
 448                if (buf < end)
 449                        *buf = sign;
 450                ++buf;
 451        }
 452        /* "0x" / "0" prefix */
 453        if (need_pfx) {
 454                if (spec.base == 16 || !is_zero) {
 455                        if (buf < end)
 456                                *buf = '0';
 457                        ++buf;
 458                }
 459                if (spec.base == 16) {
 460                        if (buf < end)
 461                                *buf = ('X' | locase);
 462                        ++buf;
 463                }
 464        }
 465        /* zero or space padding */
 466        if (!(spec.flags & LEFT)) {
 467                char c = (spec.flags & ZEROPAD) ? '0' : ' ';
 468                while (--spec.field_width >= 0) {
 469                        if (buf < end)
 470                                *buf = c;
 471                        ++buf;
 472                }
 473        }
 474        /* hmm even more zero padding? */
 475        while (i <= --spec.precision) {
 476                if (buf < end)
 477                        *buf = '0';
 478                ++buf;
 479        }
 480        /* actual digits of result */
 481        while (--i >= 0) {
 482                if (buf < end)
 483                        *buf = tmp[i];
 484                ++buf;
 485        }
 486        /* trailing space padding */
 487        while (--spec.field_width >= 0) {
 488                if (buf < end)
 489                        *buf = ' ';
 490                ++buf;
 491        }
 492
 493        return buf;
 494}
 495
 496static noinline_for_stack
 497char *string(char *buf, char *end, const char *s, struct printf_spec spec)
 498{
 499        int len, i;
 500
 501        if ((unsigned long)s < PAGE_SIZE)
 502                s = "(null)";
 503
 504        len = strnlen(s, spec.precision);
 505
 506        if (!(spec.flags & LEFT)) {
 507                while (len < spec.field_width--) {
 508                        if (buf < end)
 509                                *buf = ' ';
 510                        ++buf;
 511                }
 512        }
 513        for (i = 0; i < len; ++i) {
 514                if (buf < end)
 515                        *buf = *s;
 516                ++buf; ++s;
 517        }
 518        while (len < spec.field_width--) {
 519                if (buf < end)
 520                        *buf = ' ';
 521                ++buf;
 522        }
 523
 524        return buf;
 525}
 526
 527static noinline_for_stack
 528char *symbol_string(char *buf, char *end, void *ptr,
 529                    struct printf_spec spec, char ext)
 530{
 531        unsigned long value = (unsigned long) ptr;
 532#ifdef CONFIG_KALLSYMS
 533        char sym[KSYM_SYMBOL_LEN];
 534        if (ext == 'B')
 535                sprint_backtrace(sym, value);
 536        else if (ext != 'f' && ext != 's')
 537                sprint_symbol(sym, value);
 538        else
 539                sprint_symbol_no_offset(sym, value);
 540
 541        return string(buf, end, sym, spec);
 542#else
 543        spec.field_width = 2 * sizeof(void *);
 544        spec.flags |= SPECIAL | SMALL | ZEROPAD;
 545        spec.base = 16;
 546
 547        return number(buf, end, value, spec);
 548#endif
 549}
 550
 551static noinline_for_stack
 552char *resource_string(char *buf, char *end, struct resource *res,
 553                      struct printf_spec spec, const char *fmt)
 554{
 555#ifndef IO_RSRC_PRINTK_SIZE
 556#define IO_RSRC_PRINTK_SIZE     6
 557#endif
 558
 559#ifndef MEM_RSRC_PRINTK_SIZE
 560#define MEM_RSRC_PRINTK_SIZE    10
 561#endif
 562        static const struct printf_spec io_spec = {
 563                .base = 16,
 564                .field_width = IO_RSRC_PRINTK_SIZE,
 565                .precision = -1,
 566                .flags = SPECIAL | SMALL | ZEROPAD,
 567        };
 568        static const struct printf_spec mem_spec = {
 569                .base = 16,
 570                .field_width = MEM_RSRC_PRINTK_SIZE,
 571                .precision = -1,
 572                .flags = SPECIAL | SMALL | ZEROPAD,
 573        };
 574        static const struct printf_spec bus_spec = {
 575                .base = 16,
 576                .field_width = 2,
 577                .precision = -1,
 578                .flags = SMALL | ZEROPAD,
 579        };
 580        static const struct printf_spec dec_spec = {
 581                .base = 10,
 582                .precision = -1,
 583                .flags = 0,
 584        };
 585        static const struct printf_spec str_spec = {
 586                .field_width = -1,
 587                .precision = 10,
 588                .flags = LEFT,
 589        };
 590        static const struct printf_spec flag_spec = {
 591                .base = 16,
 592                .precision = -1,
 593                .flags = SPECIAL | SMALL,
 594        };
 595
 596        /* 32-bit res (sizeof==4): 10 chars in dec, 10 in hex ("0x" + 8)
 597         * 64-bit res (sizeof==8): 20 chars in dec, 18 in hex ("0x" + 16) */
 598#define RSRC_BUF_SIZE           ((2 * sizeof(resource_size_t)) + 4)
 599#define FLAG_BUF_SIZE           (2 * sizeof(res->flags))
 600#define DECODED_BUF_SIZE        sizeof("[mem - 64bit pref window disabled]")
 601#define RAW_BUF_SIZE            sizeof("[mem - flags 0x]")
 602        char sym[max(2*RSRC_BUF_SIZE + DECODED_BUF_SIZE,
 603                     2*RSRC_BUF_SIZE + FLAG_BUF_SIZE + RAW_BUF_SIZE)];
 604
 605        char *p = sym, *pend = sym + sizeof(sym);
 606        int decode = (fmt[0] == 'R') ? 1 : 0;
 607        const struct printf_spec *specp;
 608
 609        *p++ = '[';
 610        if (res->flags & IORESOURCE_IO) {
 611                p = string(p, pend, "io  ", str_spec);
 612                specp = &io_spec;
 613        } else if (res->flags & IORESOURCE_MEM) {
 614                p = string(p, pend, "mem ", str_spec);
 615                specp = &mem_spec;
 616        } else if (res->flags & IORESOURCE_IRQ) {
 617                p = string(p, pend, "irq ", str_spec);
 618                specp = &dec_spec;
 619        } else if (res->flags & IORESOURCE_DMA) {
 620                p = string(p, pend, "dma ", str_spec);
 621                specp = &dec_spec;
 622        } else if (res->flags & IORESOURCE_BUS) {
 623                p = string(p, pend, "bus ", str_spec);
 624                specp = &bus_spec;
 625        } else {
 626                p = string(p, pend, "??? ", str_spec);
 627                specp = &mem_spec;
 628                decode = 0;
 629        }
 630        p = number(p, pend, res->start, *specp);
 631        if (res->start != res->end) {
 632                *p++ = '-';
 633                p = number(p, pend, res->end, *specp);
 634        }
 635        if (decode) {
 636                if (res->flags & IORESOURCE_MEM_64)
 637                        p = string(p, pend, " 64bit", str_spec);
 638                if (res->flags & IORESOURCE_PREFETCH)
 639                        p = string(p, pend, " pref", str_spec);
 640                if (res->flags & IORESOURCE_WINDOW)
 641                        p = string(p, pend, " window", str_spec);
 642                if (res->flags & IORESOURCE_DISABLED)
 643                        p = string(p, pend, " disabled", str_spec);
 644        } else {
 645                p = string(p, pend, " flags ", str_spec);
 646                p = number(p, pend, res->flags, flag_spec);
 647        }
 648        *p++ = ']';
 649        *p = '\0';
 650
 651        return string(buf, end, sym, spec);
 652}
 653
 654static noinline_for_stack
 655char *hex_string(char *buf, char *end, u8 *addr, struct printf_spec spec,
 656                 const char *fmt)
 657{
 658        int i, len = 1;         /* if we pass '%ph[CDN]', field witdh remains
 659                                   negative value, fallback to the default */
 660        char separator;
 661
 662        if (spec.field_width == 0)
 663                /* nothing to print */
 664                return buf;
 665
 666        if (ZERO_OR_NULL_PTR(addr))
 667                /* NULL pointer */
 668                return string(buf, end, NULL, spec);
 669
 670        switch (fmt[1]) {
 671        case 'C':
 672                separator = ':';
 673                break;
 674        case 'D':
 675                separator = '-';
 676                break;
 677        case 'N':
 678                separator = 0;
 679                break;
 680        default:
 681                separator = ' ';
 682                break;
 683        }
 684
 685        if (spec.field_width > 0)
 686                len = min_t(int, spec.field_width, 64);
 687
 688        for (i = 0; i < len && buf < end - 1; i++) {
 689                buf = hex_byte_pack(buf, addr[i]);
 690
 691                if (buf < end && separator && i != len - 1)
 692                        *buf++ = separator;
 693        }
 694
 695        return buf;
 696}
 697
 698static noinline_for_stack
 699char *mac_address_string(char *buf, char *end, u8 *addr,
 700                         struct printf_spec spec, const char *fmt)
 701{
 702        char mac_addr[sizeof("xx:xx:xx:xx:xx:xx")];
 703        char *p = mac_addr;
 704        int i;
 705        char separator;
 706        bool reversed = false;
 707
 708        switch (fmt[1]) {
 709        case 'F':
 710                separator = '-';
 711                break;
 712
 713        case 'R':
 714                reversed = true;
 715                /* fall through */
 716
 717        default:
 718                separator = ':';
 719                break;
 720        }
 721
 722        for (i = 0; i < 6; i++) {
 723                if (reversed)
 724                        p = hex_byte_pack(p, addr[5 - i]);
 725                else
 726                        p = hex_byte_pack(p, addr[i]);
 727
 728                if (fmt[0] == 'M' && i != 5)
 729                        *p++ = separator;
 730        }
 731        *p = '\0';
 732
 733        return string(buf, end, mac_addr, spec);
 734}
 735
 736static noinline_for_stack
 737char *ip4_string(char *p, const u8 *addr, const char *fmt)
 738{
 739        int i;
 740        bool leading_zeros = (fmt[0] == 'i');
 741        int index;
 742        int step;
 743
 744        switch (fmt[2]) {
 745        case 'h':
 746#ifdef __BIG_ENDIAN
 747                index = 0;
 748                step = 1;
 749#else
 750                index = 3;
 751                step = -1;
 752#endif
 753                break;
 754        case 'l':
 755                index = 3;
 756                step = -1;
 757                break;
 758        case 'n':
 759        case 'b':
 760        default:
 761                index = 0;
 762                step = 1;
 763                break;
 764        }
 765        for (i = 0; i < 4; i++) {
 766                char temp[3];   /* hold each IP quad in reverse order */
 767                int digits = put_dec_trunc8(temp, addr[index]) - temp;
 768                if (leading_zeros) {
 769                        if (digits < 3)
 770                                *p++ = '0';
 771                        if (digits < 2)
 772                                *p++ = '0';
 773                }
 774                /* reverse the digits in the quad */
 775                while (digits--)
 776                        *p++ = temp[digits];
 777                if (i < 3)
 778                        *p++ = '.';
 779                index += step;
 780        }
 781        *p = '\0';
 782
 783        return p;
 784}
 785
 786static noinline_for_stack
 787char *ip6_compressed_string(char *p, const char *addr)
 788{
 789        int i, j, range;
 790        unsigned char zerolength[8];
 791        int longest = 1;
 792        int colonpos = -1;
 793        u16 word;
 794        u8 hi, lo;
 795        bool needcolon = false;
 796        bool useIPv4;
 797        struct in6_addr in6;
 798
 799        memcpy(&in6, addr, sizeof(struct in6_addr));
 800
 801        useIPv4 = ipv6_addr_v4mapped(&in6) || ipv6_addr_is_isatap(&in6);
 802
 803        memset(zerolength, 0, sizeof(zerolength));
 804
 805        if (useIPv4)
 806                range = 6;
 807        else
 808                range = 8;
 809
 810        /* find position of longest 0 run */
 811        for (i = 0; i < range; i++) {
 812                for (j = i; j < range; j++) {
 813                        if (in6.s6_addr16[j] != 0)
 814                                break;
 815                        zerolength[i]++;
 816                }
 817        }
 818        for (i = 0; i < range; i++) {
 819                if (zerolength[i] > longest) {
 820                        longest = zerolength[i];
 821                        colonpos = i;
 822                }
 823        }
 824        if (longest == 1)               /* don't compress a single 0 */
 825                colonpos = -1;
 826
 827        /* emit address */
 828        for (i = 0; i < range; i++) {
 829                if (i == colonpos) {
 830                        if (needcolon || i == 0)
 831                                *p++ = ':';
 832                        *p++ = ':';
 833                        needcolon = false;
 834                        i += longest - 1;
 835                        continue;
 836                }
 837                if (needcolon) {
 838                        *p++ = ':';
 839                        needcolon = false;
 840                }
 841                /* hex u16 without leading 0s */
 842                word = ntohs(in6.s6_addr16[i]);
 843                hi = word >> 8;
 844                lo = word & 0xff;
 845                if (hi) {
 846                        if (hi > 0x0f)
 847                                p = hex_byte_pack(p, hi);
 848                        else
 849                                *p++ = hex_asc_lo(hi);
 850                        p = hex_byte_pack(p, lo);
 851                }
 852                else if (lo > 0x0f)
 853                        p = hex_byte_pack(p, lo);
 854                else
 855                        *p++ = hex_asc_lo(lo);
 856                needcolon = true;
 857        }
 858
 859        if (useIPv4) {
 860                if (needcolon)
 861                        *p++ = ':';
 862                p = ip4_string(p, &in6.s6_addr[12], "I4");
 863        }
 864        *p = '\0';
 865
 866        return p;
 867}
 868
 869static noinline_for_stack
 870char *ip6_string(char *p, const char *addr, const char *fmt)
 871{
 872        int i;
 873
 874        for (i = 0; i < 8; i++) {
 875                p = hex_byte_pack(p, *addr++);
 876                p = hex_byte_pack(p, *addr++);
 877                if (fmt[0] == 'I' && i != 7)
 878                        *p++ = ':';
 879        }
 880        *p = '\0';
 881
 882        return p;
 883}
 884
 885static noinline_for_stack
 886char *ip6_addr_string(char *buf, char *end, const u8 *addr,
 887                      struct printf_spec spec, const char *fmt)
 888{
 889        char ip6_addr[sizeof("xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255")];
 890
 891        if (fmt[0] == 'I' && fmt[2] == 'c')
 892                ip6_compressed_string(ip6_addr, addr);
 893        else
 894                ip6_string(ip6_addr, addr, fmt);
 895
 896        return string(buf, end, ip6_addr, spec);
 897}
 898
 899static noinline_for_stack
 900char *ip4_addr_string(char *buf, char *end, const u8 *addr,
 901                      struct printf_spec spec, const char *fmt)
 902{
 903        char ip4_addr[sizeof("255.255.255.255")];
 904
 905        ip4_string(ip4_addr, addr, fmt);
 906
 907        return string(buf, end, ip4_addr, spec);
 908}
 909
 910static noinline_for_stack
 911char *uuid_string(char *buf, char *end, const u8 *addr,
 912                  struct printf_spec spec, const char *fmt)
 913{
 914        char uuid[sizeof("xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx")];
 915        char *p = uuid;
 916        int i;
 917        static const u8 be[16] = {0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15};
 918        static const u8 le[16] = {3,2,1,0,5,4,7,6,8,9,10,11,12,13,14,15};
 919        const u8 *index = be;
 920        bool uc = false;
 921
 922        switch (*(++fmt)) {
 923        case 'L':
 924                uc = true;              /* fall-through */
 925        case 'l':
 926                index = le;
 927                break;
 928        case 'B':
 929                uc = true;
 930                break;
 931        }
 932
 933        for (i = 0; i < 16; i++) {
 934                p = hex_byte_pack(p, addr[index[i]]);
 935                switch (i) {
 936                case 3:
 937                case 5:
 938                case 7:
 939                case 9:
 940                        *p++ = '-';
 941                        break;
 942                }
 943        }
 944
 945        *p = 0;
 946
 947        if (uc) {
 948                p = uuid;
 949                do {
 950                        *p = toupper(*p);
 951                } while (*(++p));
 952        }
 953
 954        return string(buf, end, uuid, spec);
 955}
 956
 957static
 958char *netdev_feature_string(char *buf, char *end, const u8 *addr,
 959                      struct printf_spec spec)
 960{
 961        spec.flags |= SPECIAL | SMALL | ZEROPAD;
 962        if (spec.field_width == -1)
 963                spec.field_width = 2 + 2 * sizeof(netdev_features_t);
 964        spec.base = 16;
 965
 966        return number(buf, end, *(const netdev_features_t *)addr, spec);
 967}
 968
 969int kptr_restrict __read_mostly;
 970
 971/*
 972 * Show a '%p' thing.  A kernel extension is that the '%p' is followed
 973 * by an extra set of alphanumeric characters that are extended format
 974 * specifiers.
 975 *
 976 * Right now we handle:
 977 *
 978 * - 'F' For symbolic function descriptor pointers with offset
 979 * - 'f' For simple symbolic function names without offset
 980 * - 'S' For symbolic direct pointers with offset
 981 * - 's' For symbolic direct pointers without offset
 982 * - 'B' For backtraced symbolic direct pointers with offset
 983 * - 'R' For decoded struct resource, e.g., [mem 0x0-0x1f 64bit pref]
 984 * - 'r' For raw struct resource, e.g., [mem 0x0-0x1f flags 0x201]
 985 * - 'M' For a 6-byte MAC address, it prints the address in the
 986 *       usual colon-separated hex notation
 987 * - 'm' For a 6-byte MAC address, it prints the hex address without colons
 988 * - 'MF' For a 6-byte MAC FDDI address, it prints the address
 989 *       with a dash-separated hex notation
 990 * - '[mM]R' For a 6-byte MAC address, Reverse order (Bluetooth)
 991 * - 'I' [46] for IPv4/IPv6 addresses printed in the usual way
 992 *       IPv4 uses dot-separated decimal without leading 0's (1.2.3.4)
 993 *       IPv6 uses colon separated network-order 16 bit hex with leading 0's
 994 * - 'i' [46] for 'raw' IPv4/IPv6 addresses
 995 *       IPv6 omits the colons (01020304...0f)
 996 *       IPv4 uses dot-separated decimal with leading 0's (010.123.045.006)
 997 * - '[Ii]4[hnbl]' IPv4 addresses in host, network, big or little endian order
 998 * - 'I6c' for IPv6 addresses printed as specified by
 999 *       http://tools.ietf.org/html/rfc5952
1000 * - 'U' For a 16 byte UUID/GUID, it prints the UUID/GUID in the form
1001 *       "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx"
1002 *       Options for %pU are:
1003 *         b big endian lower case hex (default)
1004 *         B big endian UPPER case hex
1005 *         l little endian lower case hex
1006 *         L little endian UPPER case hex
1007 *           big endian output byte order is:
1008 *             [0][1][2][3]-[4][5]-[6][7]-[8][9]-[10][11][12][13][14][15]
1009 *           little endian output byte order is:
1010 *             [3][2][1][0]-[5][4]-[7][6]-[8][9]-[10][11][12][13][14][15]
1011 * - 'V' For a struct va_format which contains a format string * and va_list *,
1012 *       call vsnprintf(->format, *->va_list).
1013 *       Implements a "recursive vsnprintf".
1014 *       Do not use this feature without some mechanism to verify the
1015 *       correctness of the format string and va_list arguments.
1016 * - 'K' For a kernel pointer that should be hidden from unprivileged users
1017 * - 'NF' For a netdev_features_t
1018 * - 'h[CDN]' For a variable-length buffer, it prints it as a hex string with
1019 *            a certain separator (' ' by default):
1020 *              C colon
1021 *              D dash
1022 *              N no separator
1023 *            The maximum supported length is 64 bytes of the input. Consider
1024 *            to use print_hex_dump() for the larger input.
1025 *
1026 * Note: The difference between 'S' and 'F' is that on ia64 and ppc64
1027 * function pointers are really function descriptors, which contain a
1028 * pointer to the real address.
1029 */
1030static noinline_for_stack
1031char *pointer(const char *fmt, char *buf, char *end, void *ptr,
1032              struct printf_spec spec)
1033{
1034        int default_width = 2 * sizeof(void *) + (spec.flags & SPECIAL ? 2 : 0);
1035
1036        if (!ptr && *fmt != 'K') {
1037                /*
1038                 * Print (null) with the same width as a pointer so it makes
1039                 * tabular output look nice.
1040                 */
1041                if (spec.field_width == -1)
1042                        spec.field_width = default_width;
1043                return string(buf, end, "(null)", spec);
1044        }
1045
1046        switch (*fmt) {
1047        case 'F':
1048        case 'f':
1049                ptr = dereference_function_descriptor(ptr);
1050                /* Fallthrough */
1051        case 'S':
1052        case 's':
1053        case 'B':
1054                return symbol_string(buf, end, ptr, spec, *fmt);
1055        case 'R':
1056        case 'r':
1057                return resource_string(buf, end, ptr, spec, fmt);
1058        case 'h':
1059                return hex_string(buf, end, ptr, spec, fmt);
1060        case 'M':                       /* Colon separated: 00:01:02:03:04:05 */
1061        case 'm':                       /* Contiguous: 000102030405 */
1062                                        /* [mM]F (FDDI) */
1063                                        /* [mM]R (Reverse order; Bluetooth) */
1064                return mac_address_string(buf, end, ptr, spec, fmt);
1065        case 'I':                       /* Formatted IP supported
1066                                         * 4:   1.2.3.4
1067                                         * 6:   0001:0203:...:0708
1068                                         * 6c:  1::708 or 1::1.2.3.4
1069                                         */
1070        case 'i':                       /* Contiguous:
1071                                         * 4:   001.002.003.004
1072                                         * 6:   000102...0f
1073                                         */
1074                switch (fmt[1]) {
1075                case '6':
1076                        return ip6_addr_string(buf, end, ptr, spec, fmt);
1077                case '4':
1078                        return ip4_addr_string(buf, end, ptr, spec, fmt);
1079                }
1080                break;
1081        case 'U':
1082                return uuid_string(buf, end, ptr, spec, fmt);
1083        case 'V':
1084                {
1085                        va_list va;
1086
1087                        va_copy(va, *((struct va_format *)ptr)->va);
1088                        buf += vsnprintf(buf, end > buf ? end - buf : 0,
1089                                         ((struct va_format *)ptr)->fmt, va);
1090                        va_end(va);
1091                        return buf;
1092                }
1093        case 'K':
1094                /*
1095                 * %pK cannot be used in IRQ context because its test
1096                 * for CAP_SYSLOG would be meaningless.
1097                 */
1098                if (kptr_restrict && (in_irq() || in_serving_softirq() ||
1099                                      in_nmi())) {
1100                        if (spec.field_width == -1)
1101                                spec.field_width = default_width;
1102                        return string(buf, end, "pK-error", spec);
1103                }
1104                if (!((kptr_restrict == 0) ||
1105                      (kptr_restrict == 1 &&
1106                       has_capability_noaudit(current, CAP_SYSLOG))))
1107                        ptr = NULL;
1108                break;
1109        case 'N':
1110                switch (fmt[1]) {
1111                case 'F':
1112                        return netdev_feature_string(buf, end, ptr, spec);
1113                }
1114                break;
1115        }
1116        spec.flags |= SMALL;
1117        if (spec.field_width == -1) {
1118                spec.field_width = default_width;
1119                spec.flags |= ZEROPAD;
1120        }
1121        spec.base = 16;
1122
1123        return number(buf, end, (unsigned long) ptr, spec);
1124}
1125
1126/*
1127 * Helper function to decode printf style format.
1128 * Each call decode a token from the format and return the
1129 * number of characters read (or likely the delta where it wants
1130 * to go on the next call).
1131 * The decoded token is returned through the parameters
1132 *
1133 * 'h', 'l', or 'L' for integer fields
1134 * 'z' support added 23/7/1999 S.H.
1135 * 'z' changed to 'Z' --davidm 1/25/99
1136 * 't' added for ptrdiff_t
1137 *
1138 * @fmt: the format string
1139 * @type of the token returned
1140 * @flags: various flags such as +, -, # tokens..
1141 * @field_width: overwritten width
1142 * @base: base of the number (octal, hex, ...)
1143 * @precision: precision of a number
1144 * @qualifier: qualifier of a number (long, size_t, ...)
1145 */
1146static noinline_for_stack
1147int format_decode(const char *fmt, struct printf_spec *spec)
1148{
1149        const char *start = fmt;
1150
1151        /* we finished early by reading the field width */
1152        if (spec->type == FORMAT_TYPE_WIDTH) {
1153                if (spec->field_width < 0) {
1154                        spec->field_width = -spec->field_width;
1155                        spec->flags |= LEFT;
1156                }
1157                spec->type = FORMAT_TYPE_NONE;
1158                goto precision;
1159        }
1160
1161        /* we finished early by reading the precision */
1162        if (spec->type == FORMAT_TYPE_PRECISION) {
1163                if (spec->precision < 0)
1164                        spec->precision = 0;
1165
1166                spec->type = FORMAT_TYPE_NONE;
1167                goto qualifier;
1168        }
1169
1170        /* By default */
1171        spec->type = FORMAT_TYPE_NONE;
1172
1173        for (; *fmt ; ++fmt) {
1174                if (*fmt == '%')
1175                        break;
1176        }
1177
1178        /* Return the current non-format string */
1179        if (fmt != start || !*fmt)
1180                return fmt - start;
1181
1182        /* Process flags */
1183        spec->flags = 0;
1184
1185        while (1) { /* this also skips first '%' */
1186                bool found = true;
1187
1188                ++fmt;
1189
1190                switch (*fmt) {
1191                case '-': spec->flags |= LEFT;    break;
1192                case '+': spec->flags |= PLUS;    break;
1193                case ' ': spec->flags |= SPACE;   break;
1194                case '#': spec->flags |= SPECIAL; break;
1195                case '0': spec->flags |= ZEROPAD; break;
1196                default:  found = false;
1197                }
1198
1199                if (!found)
1200                        break;
1201        }
1202
1203        /* get field width */
1204        spec->field_width = -1;
1205
1206        if (isdigit(*fmt))
1207                spec->field_width = skip_atoi(&fmt);
1208        else if (*fmt == '*') {
1209                /* it's the next argument */
1210                spec->type = FORMAT_TYPE_WIDTH;
1211                return ++fmt - start;
1212        }
1213
1214precision:
1215        /* get the precision */
1216        spec->precision = -1;
1217        if (*fmt == '.') {
1218                ++fmt;
1219                if (isdigit(*fmt)) {
1220                        spec->precision = skip_atoi(&fmt);
1221                        if (spec->precision < 0)
1222                                spec->precision = 0;
1223                } else if (*fmt == '*') {
1224                        /* it's the next argument */
1225                        spec->type = FORMAT_TYPE_PRECISION;
1226                        return ++fmt - start;
1227                }
1228        }
1229
1230qualifier:
1231        /* get the conversion qualifier */
1232        spec->qualifier = -1;
1233        if (*fmt == 'h' || _tolower(*fmt) == 'l' ||
1234            _tolower(*fmt) == 'z' || *fmt == 't') {
1235                spec->qualifier = *fmt++;
1236                if (unlikely(spec->qualifier == *fmt)) {
1237                        if (spec->qualifier == 'l') {
1238                                spec->qualifier = 'L';
1239                                ++fmt;
1240                        } else if (spec->qualifier == 'h') {
1241                                spec->qualifier = 'H';
1242                                ++fmt;
1243                        }
1244                }
1245        }
1246
1247        /* default base */
1248        spec->base = 10;
1249        switch (*fmt) {
1250        case 'c':
1251                spec->type = FORMAT_TYPE_CHAR;
1252                return ++fmt - start;
1253
1254        case 's':
1255                spec->type = FORMAT_TYPE_STR;
1256                return ++fmt - start;
1257
1258        case 'p':
1259                spec->type = FORMAT_TYPE_PTR;
1260                return fmt - start;
1261                /* skip alnum */
1262
1263        case 'n':
1264                spec->type = FORMAT_TYPE_NRCHARS;
1265                return ++fmt - start;
1266
1267        case '%':
1268                spec->type = FORMAT_TYPE_PERCENT_CHAR;
1269                return ++fmt - start;
1270
1271        /* integer number formats - set up the flags and "break" */
1272        case 'o':
1273                spec->base = 8;
1274                break;
1275
1276        case 'x':
1277                spec->flags |= SMALL;
1278
1279        case 'X':
1280                spec->base = 16;
1281                break;
1282
1283        case 'd':
1284        case 'i':
1285                spec->flags |= SIGN;
1286        case 'u':
1287                break;
1288
1289        default:
1290                spec->type = FORMAT_TYPE_INVALID;
1291                return fmt - start;
1292        }
1293
1294        if (spec->qualifier == 'L')
1295                spec->type = FORMAT_TYPE_LONG_LONG;
1296        else if (spec->qualifier == 'l') {
1297                if (spec->flags & SIGN)
1298                        spec->type = FORMAT_TYPE_LONG;
1299                else
1300                        spec->type = FORMAT_TYPE_ULONG;
1301        } else if (_tolower(spec->qualifier) == 'z') {
1302                spec->type = FORMAT_TYPE_SIZE_T;
1303        } else if (spec->qualifier == 't') {
1304                spec->type = FORMAT_TYPE_PTRDIFF;
1305        } else if (spec->qualifier == 'H') {
1306                if (spec->flags & SIGN)
1307                        spec->type = FORMAT_TYPE_BYTE;
1308                else
1309                        spec->type = FORMAT_TYPE_UBYTE;
1310        } else if (spec->qualifier == 'h') {
1311                if (spec->flags & SIGN)
1312                        spec->type = FORMAT_TYPE_SHORT;
1313                else
1314                        spec->type = FORMAT_TYPE_USHORT;
1315        } else {
1316                if (spec->flags & SIGN)
1317                        spec->type = FORMAT_TYPE_INT;
1318                else
1319                        spec->type = FORMAT_TYPE_UINT;
1320        }
1321
1322        return ++fmt - start;
1323}
1324
1325/**
1326 * vsnprintf - Format a string and place it in a buffer
1327 * @buf: The buffer to place the result into
1328 * @size: The size of the buffer, including the trailing null space
1329 * @fmt: The format string to use
1330 * @args: Arguments for the format string
1331 *
1332 * This function follows C99 vsnprintf, but has some extensions:
1333 * %pS output the name of a text symbol with offset
1334 * %ps output the name of a text symbol without offset
1335 * %pF output the name of a function pointer with its offset
1336 * %pf output the name of a function pointer without its offset
1337 * %pB output the name of a backtrace symbol with its offset
1338 * %pR output the address range in a struct resource with decoded flags
1339 * %pr output the address range in a struct resource with raw flags
1340 * %pM output a 6-byte MAC address with colons
1341 * %pMR output a 6-byte MAC address with colons in reversed order
1342 * %pMF output a 6-byte MAC address with dashes
1343 * %pm output a 6-byte MAC address without colons
1344 * %pmR output a 6-byte MAC address without colons in reversed order
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) {
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                        if (!*str)
2046                                break;
2047                        while (!isspace(*fmt) && *fmt != '%' && *fmt)
2048                                fmt++;
2049                        while (!isspace(*str) && *str)
2050                                str++;
2051                        continue;
2052                }
2053
2054                /* get field width */
2055                field_width = -1;
2056                if (isdigit(*fmt))
2057                        field_width = skip_atoi(&fmt);
2058
2059                /* get conversion qualifier */
2060                qualifier = -1;
2061                if (*fmt == 'h' || _tolower(*fmt) == 'l' ||
2062                    _tolower(*fmt) == 'z') {
2063                        qualifier = *fmt++;
2064                        if (unlikely(qualifier == *fmt)) {
2065                                if (qualifier == 'h') {
2066                                        qualifier = 'H';
2067                                        fmt++;
2068                                } else if (qualifier == 'l') {
2069                                        qualifier = 'L';
2070                                        fmt++;
2071                                }
2072                        }
2073                }
2074
2075                if (!*fmt)
2076                        break;
2077
2078                if (*fmt == 'n') {
2079                        /* return number of characters read so far */
2080                        *va_arg(args, int *) = str - buf;
2081                        ++fmt;
2082                        continue;
2083                }
2084
2085                if (!*str)
2086                        break;
2087
2088                base = 10;
2089                is_sign = 0;
2090
2091                switch (*fmt++) {
2092                case 'c':
2093                {
2094                        char *s = (char *)va_arg(args, char*);
2095                        if (field_width == -1)
2096                                field_width = 1;
2097                        do {
2098                                *s++ = *str++;
2099                        } while (--field_width > 0 && *str);
2100                        num++;
2101                }
2102                continue;
2103                case 's':
2104                {
2105                        char *s = (char *)va_arg(args, char *);
2106                        if (field_width == -1)
2107                                field_width = SHRT_MAX;
2108                        /* first, skip leading white space in buffer */
2109                        str = skip_spaces(str);
2110
2111                        /* now copy until next white space */
2112                        while (*str && !isspace(*str) && field_width--)
2113                                *s++ = *str++;
2114                        *s = '\0';
2115                        num++;
2116                }
2117                continue;
2118                case 'o':
2119                        base = 8;
2120                        break;
2121                case 'x':
2122                case 'X':
2123                        base = 16;
2124                        break;
2125                case 'i':
2126                        base = 0;
2127                case 'd':
2128                        is_sign = 1;
2129                case 'u':
2130                        break;
2131                case '%':
2132                        /* looking for '%' in str */
2133                        if (*str++ != '%')
2134                                return num;
2135                        continue;
2136                default:
2137                        /* invalid format; stop here */
2138                        return num;
2139                }
2140
2141                /* have some sort of integer conversion.
2142                 * first, skip white space in buffer.
2143                 */
2144                str = skip_spaces(str);
2145
2146                digit = *str;
2147                if (is_sign && digit == '-')
2148                        digit = *(str + 1);
2149
2150                if (!digit
2151                    || (base == 16 && !isxdigit(digit))
2152                    || (base == 10 && !isdigit(digit))
2153                    || (base == 8 && (!isdigit(digit) || digit > '7'))
2154                    || (base == 0 && !isdigit(digit)))
2155                        break;
2156
2157                switch (qualifier) {
2158                case 'H':       /* that's 'hh' in format */
2159                        if (is_sign) {
2160                                signed char *s = (signed char *)va_arg(args, signed char *);
2161                                *s = (signed char)simple_strtol(str, &next, base);
2162                        } else {
2163                                unsigned char *s = (unsigned char *)va_arg(args, unsigned char *);
2164                                *s = (unsigned char)simple_strtoul(str, &next, base);
2165                        }
2166                        break;
2167                case 'h':
2168                        if (is_sign) {
2169                                short *s = (short *)va_arg(args, short *);
2170                                *s = (short)simple_strtol(str, &next, base);
2171                        } else {
2172                                unsigned short *s = (unsigned short *)va_arg(args, unsigned short *);
2173                                *s = (unsigned short)simple_strtoul(str, &next, base);
2174                        }
2175                        break;
2176                case 'l':
2177                        if (is_sign) {
2178                                long *l = (long *)va_arg(args, long *);
2179                                *l = simple_strtol(str, &next, base);
2180                        } else {
2181                                unsigned long *l = (unsigned long *)va_arg(args, unsigned long *);
2182                                *l = simple_strtoul(str, &next, base);
2183                        }
2184                        break;
2185                case 'L':
2186                        if (is_sign) {
2187                                long long *l = (long long *)va_arg(args, long long *);
2188                                *l = simple_strtoll(str, &next, base);
2189                        } else {
2190                                unsigned long long *l = (unsigned long long *)va_arg(args, unsigned long long *);
2191                                *l = simple_strtoull(str, &next, base);
2192                        }
2193                        break;
2194                case 'Z':
2195                case 'z':
2196                {
2197                        size_t *s = (size_t *)va_arg(args, size_t *);
2198                        *s = (size_t)simple_strtoul(str, &next, base);
2199                }
2200                break;
2201                default:
2202                        if (is_sign) {
2203                                int *i = (int *)va_arg(args, int *);
2204                                *i = (int)simple_strtol(str, &next, base);
2205                        } else {
2206                                unsigned int *i = (unsigned int *)va_arg(args, unsigned int*);
2207                                *i = (unsigned int)simple_strtoul(str, &next, base);
2208                        }
2209                        break;
2210                }
2211                num++;
2212
2213                if (!next)
2214                        break;
2215                str = next;
2216        }
2217
2218        return num;
2219}
2220EXPORT_SYMBOL(vsscanf);
2221
2222/**
2223 * sscanf - Unformat a buffer into a list of arguments
2224 * @buf:        input buffer
2225 * @fmt:        formatting of buffer
2226 * @...:        resulting arguments
2227 */
2228int sscanf(const char *buf, const char *fmt, ...)
2229{
2230        va_list args;
2231        int i;
2232
2233        va_start(args, fmt);
2234        i = vsscanf(buf, fmt, args);
2235        va_end(args);
2236
2237        return i;
2238}
2239EXPORT_SYMBOL(sscanf);
2240
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