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>
  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/* Works only for digits and letters, but small and fast */
  35#define TOLOWER(x) ((x) | 0x20)
  36
  37static unsigned int simple_guess_base(const char *cp)
  38{
  39        if (cp[0] == '0') {
  40                if (TOLOWER(cp[1]) == 'x' && isxdigit(cp[2]))
  41                        return 16;
  42                else
  43                        return 8;
  44        } else {
  45                return 10;
  46        }
  47}
  48
  49/**
  50 * simple_strtoull - convert a string to an unsigned long long
  51 * @cp: The start of the string
  52 * @endp: A pointer to the end of the parsed string will be placed here
  53 * @base: The number base to use
  54 */
  55unsigned long long simple_strtoull(const char *cp, char **endp, unsigned int base)
  56{
  57        unsigned long long result = 0;
  58
  59        if (!base)
  60                base = simple_guess_base(cp);
  61
  62        if (base == 16 && cp[0] == '0' && TOLOWER(cp[1]) == 'x')
  63                cp += 2;
  64
  65        while (isxdigit(*cp)) {
  66                unsigned int value;
  67
  68                value = isdigit(*cp) ? *cp - '0' : TOLOWER(*cp) - 'a' + 10;
  69                if (value >= base)
  70                        break;
  71                result = result * base + value;
  72                cp++;
  73        }
  74        if (endp)
  75                *endp = (char *)cp;
  76
  77        return result;
  78}
  79EXPORT_SYMBOL(simple_strtoull);
  80
  81/**
  82 * simple_strtoul - convert a string to an unsigned long
  83 * @cp: The start of the string
  84 * @endp: A pointer to the end of the parsed string will be placed here
  85 * @base: The number base to use
  86 */
  87unsigned long simple_strtoul(const char *cp, char **endp, unsigned int base)
  88{
  89        return simple_strtoull(cp, endp, base);
  90}
  91EXPORT_SYMBOL(simple_strtoul);
  92
  93/**
  94 * simple_strtol - convert a string to a signed long
  95 * @cp: The start of the string
  96 * @endp: A pointer to the end of the parsed string will be placed here
  97 * @base: The number base to use
  98 */
  99long simple_strtol(const char *cp, char **endp, unsigned int base)
 100{
 101        if (*cp == '-')
 102                return -simple_strtoul(cp + 1, endp, base);
 103
 104        return simple_strtoul(cp, endp, base);
 105}
 106EXPORT_SYMBOL(simple_strtol);
 107
 108/**
 109 * simple_strtoll - convert a string to a signed long long
 110 * @cp: The start of the string
 111 * @endp: A pointer to the end of the parsed string will be placed here
 112 * @base: The number base to use
 113 */
 114long long simple_strtoll(const char *cp, char **endp, unsigned int base)
 115{
 116        if (*cp == '-')
 117                return -simple_strtoull(cp + 1, endp, base);
 118
 119        return simple_strtoull(cp, endp, base);
 120}
 121EXPORT_SYMBOL(simple_strtoll);
 122
 123/**
 124 * strict_strtoul - convert a string to an unsigned long strictly
 125 * @cp: The string to be converted
 126 * @base: The number base to use
 127 * @res: The converted result value
 128 *
 129 * strict_strtoul converts a string to an unsigned long only if the
 130 * string is really an unsigned long string, any string containing
 131 * any invalid char at the tail will be rejected and -EINVAL is returned,
 132 * only a newline char at the tail is acceptible because people generally
 133 * change a module parameter in the following way:
 134 *
 135 *      echo 1024 > /sys/module/e1000/parameters/copybreak
 136 *
 137 * echo will append a newline to the tail.
 138 *
 139 * It returns 0 if conversion is successful and *res is set to the converted
 140 * value, otherwise it returns -EINVAL and *res is set to 0.
 141 *
 142 * simple_strtoul just ignores the successive invalid characters and
 143 * return the converted value of prefix part of the string.
 144 */
 145int strict_strtoul(const char *cp, unsigned int base, unsigned long *res)
 146{
 147        char *tail;
 148        unsigned long val;
 149        size_t len;
 150
 151        *res = 0;
 152        len = strlen(cp);
 153        if (len == 0)
 154                return -EINVAL;
 155
 156        val = simple_strtoul(cp, &tail, base);
 157        if (tail == cp)
 158                return -EINVAL;
 159
 160        if ((*tail == '\0') ||
 161                ((len == (size_t)(tail - cp) + 1) && (*tail == '\n'))) {
 162                *res = val;
 163                return 0;
 164        }
 165
 166        return -EINVAL;
 167}
 168EXPORT_SYMBOL(strict_strtoul);
 169
 170/**
 171 * strict_strtol - convert a string to a long strictly
 172 * @cp: The string to be converted
 173 * @base: The number base to use
 174 * @res: The converted result value
 175 *
 176 * strict_strtol is similiar to strict_strtoul, but it allows the first
 177 * character of a string is '-'.
 178 *
 179 * It returns 0 if conversion is successful and *res is set to the converted
 180 * value, otherwise it returns -EINVAL and *res is set to 0.
 181 */
 182int strict_strtol(const char *cp, unsigned int base, long *res)
 183{
 184        int ret;
 185        if (*cp == '-') {
 186                ret = strict_strtoul(cp + 1, base, (unsigned long *)res);
 187                if (!ret)
 188                        *res = -(*res);
 189        } else {
 190                ret = strict_strtoul(cp, base, (unsigned long *)res);
 191        }
 192
 193        return ret;
 194}
 195EXPORT_SYMBOL(strict_strtol);
 196
 197/**
 198 * strict_strtoull - convert a string to an unsigned long long strictly
 199 * @cp: The string to be converted
 200 * @base: The number base to use
 201 * @res: The converted result value
 202 *
 203 * strict_strtoull converts a string to an unsigned long long only if the
 204 * string is really an unsigned long long string, any string containing
 205 * any invalid char at the tail will be rejected and -EINVAL is returned,
 206 * only a newline char at the tail is acceptible because people generally
 207 * change a module parameter in the following way:
 208 *
 209 *      echo 1024 > /sys/module/e1000/parameters/copybreak
 210 *
 211 * echo will append a newline to the tail of the string.
 212 *
 213 * It returns 0 if conversion is successful and *res is set to the converted
 214 * value, otherwise it returns -EINVAL and *res is set to 0.
 215 *
 216 * simple_strtoull just ignores the successive invalid characters and
 217 * return the converted value of prefix part of the string.
 218 */
 219int strict_strtoull(const char *cp, unsigned int base, unsigned long long *res)
 220{
 221        char *tail;
 222        unsigned long long val;
 223        size_t len;
 224
 225        *res = 0;
 226        len = strlen(cp);
 227        if (len == 0)
 228                return -EINVAL;
 229
 230        val = simple_strtoull(cp, &tail, base);
 231        if (tail == cp)
 232                return -EINVAL;
 233        if ((*tail == '\0') ||
 234                ((len == (size_t)(tail - cp) + 1) && (*tail == '\n'))) {
 235                *res = val;
 236                return 0;
 237        }
 238
 239        return -EINVAL;
 240}
 241EXPORT_SYMBOL(strict_strtoull);
 242
 243/**
 244 * strict_strtoll - convert a string to a long long strictly
 245 * @cp: The string to be converted
 246 * @base: The number base to use
 247 * @res: The converted result value
 248 *
 249 * strict_strtoll is similiar to strict_strtoull, but it allows the first
 250 * character of a string is '-'.
 251 *
 252 * It returns 0 if conversion is successful and *res is set to the converted
 253 * value, otherwise it returns -EINVAL and *res is set to 0.
 254 */
 255int strict_strtoll(const char *cp, unsigned int base, long long *res)
 256{
 257        int ret;
 258        if (*cp == '-') {
 259                ret = strict_strtoull(cp + 1, base, (unsigned long long *)res);
 260                if (!ret)
 261                        *res = -(*res);
 262        } else {
 263                ret = strict_strtoull(cp, base, (unsigned long long *)res);
 264        }
 265
 266        return ret;
 267}
 268EXPORT_SYMBOL(strict_strtoll);
 269
 270static int skip_atoi(const char **s)
 271{
 272        int i = 0;
 273
 274        while (isdigit(**s))
 275                i = i*10 + *((*s)++) - '0';
 276
 277        return i;
 278}
 279
 280/* Decimal conversion is by far the most typical, and is used
 281 * for /proc and /sys data. This directly impacts e.g. top performance
 282 * with many processes running. We optimize it for speed
 283 * using code from
 284 * http://www.cs.uiowa.edu/~jones/bcd/decimal.html
 285 * (with permission from the author, Douglas W. Jones). */
 286
 287/* Formats correctly any integer in [0,99999].
 288 * Outputs from one to five digits depending on input.
 289 * On i386 gcc 4.1.2 -O2: ~250 bytes of code. */
 290static char *put_dec_trunc(char *buf, unsigned q)
 291{
 292        unsigned d3, d2, d1, d0;
 293        d1 = (q>>4) & 0xf;
 294        d2 = (q>>8) & 0xf;
 295        d3 = (q>>12);
 296
 297        d0 = 6*(d3 + d2 + d1) + (q & 0xf);
 298        q = (d0 * 0xcd) >> 11;
 299        d0 = d0 - 10*q;
 300        *buf++ = d0 + '0'; /* least significant digit */
 301        d1 = q + 9*d3 + 5*d2 + d1;
 302        if (d1 != 0) {
 303                q = (d1 * 0xcd) >> 11;
 304                d1 = d1 - 10*q;
 305                *buf++ = d1 + '0'; /* next digit */
 306
 307                d2 = q + 2*d2;
 308                if ((d2 != 0) || (d3 != 0)) {
 309                        q = (d2 * 0xd) >> 7;
 310                        d2 = d2 - 10*q;
 311                        *buf++ = d2 + '0'; /* next digit */
 312
 313                        d3 = q + 4*d3;
 314                        if (d3 != 0) {
 315                                q = (d3 * 0xcd) >> 11;
 316                                d3 = d3 - 10*q;
 317                                *buf++ = d3 + '0';  /* next digit */
 318                                if (q != 0)
 319                                        *buf++ = q + '0'; /* most sign. digit */
 320                        }
 321                }
 322        }
 323
 324        return buf;
 325}
 326/* Same with if's removed. Always emits five digits */
 327static char *put_dec_full(char *buf, unsigned q)
 328{
 329        /* BTW, if q is in [0,9999], 8-bit ints will be enough, */
 330        /* but anyway, gcc produces better code with full-sized ints */
 331        unsigned d3, d2, d1, d0;
 332        d1 = (q>>4) & 0xf;
 333        d2 = (q>>8) & 0xf;
 334        d3 = (q>>12);
 335
 336        /*
 337         * Possible ways to approx. divide by 10
 338         * gcc -O2 replaces multiply with shifts and adds
 339         * (x * 0xcd) >> 11: 11001101 - shorter code than * 0x67 (on i386)
 340         * (x * 0x67) >> 10:  1100111
 341         * (x * 0x34) >> 9:    110100 - same
 342         * (x * 0x1a) >> 8:     11010 - same
 343         * (x * 0x0d) >> 7:      1101 - same, shortest code (on i386)
 344         */
 345        d0 = 6*(d3 + d2 + d1) + (q & 0xf);
 346        q = (d0 * 0xcd) >> 11;
 347        d0 = d0 - 10*q;
 348        *buf++ = d0 + '0';
 349        d1 = q + 9*d3 + 5*d2 + d1;
 350                q = (d1 * 0xcd) >> 11;
 351                d1 = d1 - 10*q;
 352                *buf++ = d1 + '0';
 353
 354                d2 = q + 2*d2;
 355                        q = (d2 * 0xd) >> 7;
 356                        d2 = d2 - 10*q;
 357                        *buf++ = d2 + '0';
 358
 359                        d3 = q + 4*d3;
 360                                q = (d3 * 0xcd) >> 11; /* - shorter code */
 361                                /* q = (d3 * 0x67) >> 10; - would also work */
 362                                d3 = d3 - 10*q;
 363                                *buf++ = d3 + '0';
 364                                        *buf++ = q + '0';
 365
 366        return buf;
 367}
 368/* No inlining helps gcc to use registers better */
 369static noinline char *put_dec(char *buf, unsigned long long num)
 370{
 371        while (1) {
 372                unsigned rem;
 373                if (num < 100000)
 374                        return put_dec_trunc(buf, num);
 375                rem = do_div(num, 100000);
 376                buf = put_dec_full(buf, rem);
 377        }
 378}
 379
 380#define ZEROPAD 1               /* pad with zero */
 381#define SIGN    2               /* unsigned/signed long */
 382#define PLUS    4               /* show plus */
 383#define SPACE   8               /* space if plus */
 384#define LEFT    16              /* left justified */
 385#define SMALL   32              /* use lowercase in hex (must be 32 == 0x20) */
 386#define SPECIAL 64              /* prefix hex with "0x", octal with "0" */
 387
 388enum format_type {
 389        FORMAT_TYPE_NONE, /* Just a string part */
 390        FORMAT_TYPE_WIDTH,
 391        FORMAT_TYPE_PRECISION,
 392        FORMAT_TYPE_CHAR,
 393        FORMAT_TYPE_STR,
 394        FORMAT_TYPE_PTR,
 395        FORMAT_TYPE_PERCENT_CHAR,
 396        FORMAT_TYPE_INVALID,
 397        FORMAT_TYPE_LONG_LONG,
 398        FORMAT_TYPE_ULONG,
 399        FORMAT_TYPE_LONG,
 400        FORMAT_TYPE_UBYTE,
 401        FORMAT_TYPE_BYTE,
 402        FORMAT_TYPE_USHORT,
 403        FORMAT_TYPE_SHORT,
 404        FORMAT_TYPE_UINT,
 405        FORMAT_TYPE_INT,
 406        FORMAT_TYPE_NRCHARS,
 407        FORMAT_TYPE_SIZE_T,
 408        FORMAT_TYPE_PTRDIFF
 409};
 410
 411struct printf_spec {
 412        u8      type;           /* format_type enum */
 413        u8      flags;          /* flags to number() */
 414        u8      base;           /* number base, 8, 10 or 16 only */
 415        u8      qualifier;      /* number qualifier, one of 'hHlLtzZ' */
 416        s16     field_width;    /* width of output field */
 417        s16     precision;      /* # of digits/chars */
 418};
 419
 420static char *number(char *buf, char *end, unsigned long long num,
 421                        struct printf_spec spec)
 422{
 423        /* we are called with base 8, 10 or 16, only, thus don't need "G..."  */
 424        static const char digits[16] = "0123456789ABCDEF"; /* "GHIJKLMNOPQRSTUVWXYZ"; */
 425
 426        char tmp[66];
 427        char sign;
 428        char locase;
 429        int need_pfx = ((spec.flags & SPECIAL) && spec.base != 10);
 430        int i;
 431
 432        /* locase = 0 or 0x20. ORing digits or letters with 'locase'
 433         * produces same digits or (maybe lowercased) letters */
 434        locase = (spec.flags & SMALL);
 435        if (spec.flags & LEFT)
 436                spec.flags &= ~ZEROPAD;
 437        sign = 0;
 438        if (spec.flags & SIGN) {
 439                if ((signed long long)num < 0) {
 440                        sign = '-';
 441                        num = -(signed long long)num;
 442                        spec.field_width--;
 443                } else if (spec.flags & PLUS) {
 444                        sign = '+';
 445                        spec.field_width--;
 446                } else if (spec.flags & SPACE) {
 447                        sign = ' ';
 448                        spec.field_width--;
 449                }
 450        }
 451        if (need_pfx) {
 452                spec.field_width--;
 453                if (spec.base == 16)
 454                        spec.field_width--;
 455        }
 456
 457        /* generate full string in tmp[], in reverse order */
 458        i = 0;
 459        if (num == 0)
 460                tmp[i++] = '0';
 461        /* Generic code, for any base:
 462        else do {
 463                tmp[i++] = (digits[do_div(num,base)] | locase);
 464        } while (num != 0);
 465        */
 466        else if (spec.base != 10) { /* 8 or 16 */
 467                int mask = spec.base - 1;
 468                int shift = 3;
 469
 470                if (spec.base == 16)
 471                        shift = 4;
 472                do {
 473                        tmp[i++] = (digits[((unsigned char)num) & mask] | locase);
 474                        num >>= shift;
 475                } while (num);
 476        } else { /* base 10 */
 477                i = put_dec(tmp, num) - tmp;
 478        }
 479
 480        /* printing 100 using %2d gives "100", not "00" */
 481        if (i > spec.precision)
 482                spec.precision = i;
 483        /* leading space padding */
 484        spec.field_width -= spec.precision;
 485        if (!(spec.flags & (ZEROPAD+LEFT))) {
 486                while (--spec.field_width >= 0) {
 487                        if (buf < end)
 488                                *buf = ' ';
 489                        ++buf;
 490                }
 491        }
 492        /* sign */
 493        if (sign) {
 494                if (buf < end)
 495                        *buf = sign;
 496                ++buf;
 497        }
 498        /* "0x" / "0" prefix */
 499        if (need_pfx) {
 500                if (buf < end)
 501                        *buf = '0';
 502                ++buf;
 503                if (spec.base == 16) {
 504                        if (buf < end)
 505                                *buf = ('X' | locase);
 506                        ++buf;
 507                }
 508        }
 509        /* zero or space padding */
 510        if (!(spec.flags & LEFT)) {
 511                char c = (spec.flags & ZEROPAD) ? '0' : ' ';
 512                while (--spec.field_width >= 0) {
 513                        if (buf < end)
 514                                *buf = c;
 515                        ++buf;
 516                }
 517        }
 518        /* hmm even more zero padding? */
 519        while (i <= --spec.precision) {
 520                if (buf < end)
 521                        *buf = '0';
 522                ++buf;
 523        }
 524        /* actual digits of result */
 525        while (--i >= 0) {
 526                if (buf < end)
 527                        *buf = tmp[i];
 528                ++buf;
 529        }
 530        /* trailing space padding */
 531        while (--spec.field_width >= 0) {
 532                if (buf < end)
 533                        *buf = ' ';
 534                ++buf;
 535        }
 536
 537        return buf;
 538}
 539
 540static char *string(char *buf, char *end, const char *s, struct printf_spec spec)
 541{
 542        int len, i;
 543
 544        if ((unsigned long)s < PAGE_SIZE)
 545                s = "(null)";
 546
 547        len = strnlen(s, spec.precision);
 548
 549        if (!(spec.flags & LEFT)) {
 550                while (len < spec.field_width--) {
 551                        if (buf < end)
 552                                *buf = ' ';
 553                        ++buf;
 554                }
 555        }
 556        for (i = 0; i < len; ++i) {
 557                if (buf < end)
 558                        *buf = *s;
 559                ++buf; ++s;
 560        }
 561        while (len < spec.field_width--) {
 562                if (buf < end)
 563                        *buf = ' ';
 564                ++buf;
 565        }
 566
 567        return buf;
 568}
 569
 570static char *symbol_string(char *buf, char *end, void *ptr,
 571                                struct printf_spec spec, char ext)
 572{
 573        unsigned long value = (unsigned long) ptr;
 574#ifdef CONFIG_KALLSYMS
 575        char sym[KSYM_SYMBOL_LEN];
 576        if (ext != 'f' && ext != 's')
 577                sprint_symbol(sym, value);
 578        else
 579                kallsyms_lookup(value, NULL, NULL, NULL, sym);
 580
 581        return string(buf, end, sym, spec);
 582#else
 583        spec.field_width = 2 * sizeof(void *);
 584        spec.flags |= SPECIAL | SMALL | ZEROPAD;
 585        spec.base = 16;
 586
 587        return number(buf, end, value, spec);
 588#endif
 589}
 590
 591static char *resource_string(char *buf, char *end, struct resource *res,
 592                                struct printf_spec spec, const char *fmt)
 593{
 594#ifndef IO_RSRC_PRINTK_SIZE
 595#define IO_RSRC_PRINTK_SIZE     6
 596#endif
 597
 598#ifndef MEM_RSRC_PRINTK_SIZE
 599#define MEM_RSRC_PRINTK_SIZE    10
 600#endif
 601        static const struct printf_spec io_spec = {
 602                .base = 16,
 603                .field_width = IO_RSRC_PRINTK_SIZE,
 604                .precision = -1,
 605                .flags = SPECIAL | SMALL | ZEROPAD,
 606        };
 607        static const struct printf_spec mem_spec = {
 608                .base = 16,
 609                .field_width = MEM_RSRC_PRINTK_SIZE,
 610                .precision = -1,
 611                .flags = SPECIAL | SMALL | ZEROPAD,
 612        };
 613        static const struct printf_spec bus_spec = {
 614                .base = 16,
 615                .field_width = 2,
 616                .precision = -1,
 617                .flags = SMALL | ZEROPAD,
 618        };
 619        static const struct printf_spec dec_spec = {
 620                .base = 10,
 621                .precision = -1,
 622                .flags = 0,
 623        };
 624        static const struct printf_spec str_spec = {
 625                .field_width = -1,
 626                .precision = 10,
 627                .flags = LEFT,
 628        };
 629        static const struct printf_spec flag_spec = {
 630                .base = 16,
 631                .precision = -1,
 632                .flags = SPECIAL | SMALL,
 633        };
 634
 635        /* 32-bit res (sizeof==4): 10 chars in dec, 10 in hex ("0x" + 8)
 636         * 64-bit res (sizeof==8): 20 chars in dec, 18 in hex ("0x" + 16) */
 637#define RSRC_BUF_SIZE           ((2 * sizeof(resource_size_t)) + 4)
 638#define FLAG_BUF_SIZE           (2 * sizeof(res->flags))
 639#define DECODED_BUF_SIZE        sizeof("[mem - 64bit pref window disabled]")
 640#define RAW_BUF_SIZE            sizeof("[mem - flags 0x]")
 641        char sym[max(2*RSRC_BUF_SIZE + DECODED_BUF_SIZE,
 642                     2*RSRC_BUF_SIZE + FLAG_BUF_SIZE + RAW_BUF_SIZE)];
 643
 644        char *p = sym, *pend = sym + sizeof(sym);
 645        int decode = (fmt[0] == 'R') ? 1 : 0;
 646        const struct printf_spec *specp;
 647
 648        *p++ = '[';
 649        if (res->flags & IORESOURCE_IO) {
 650                p = string(p, pend, "io  ", str_spec);
 651                specp = &io_spec;
 652        } else if (res->flags & IORESOURCE_MEM) {
 653                p = string(p, pend, "mem ", str_spec);
 654                specp = &mem_spec;
 655        } else if (res->flags & IORESOURCE_IRQ) {
 656                p = string(p, pend, "irq ", str_spec);
 657                specp = &dec_spec;
 658        } else if (res->flags & IORESOURCE_DMA) {
 659                p = string(p, pend, "dma ", str_spec);
 660                specp = &dec_spec;
 661        } else if (res->flags & IORESOURCE_BUS) {
 662                p = string(p, pend, "bus ", str_spec);
 663                specp = &bus_spec;
 664        } else {
 665                p = string(p, pend, "??? ", str_spec);
 666                specp = &mem_spec;
 667                decode = 0;
 668        }
 669        p = number(p, pend, res->start, *specp);
 670        if (res->start != res->end) {
 671                *p++ = '-';
 672                p = number(p, pend, res->end, *specp);
 673        }
 674        if (decode) {
 675                if (res->flags & IORESOURCE_MEM_64)
 676                        p = string(p, pend, " 64bit", str_spec);
 677                if (res->flags & IORESOURCE_PREFETCH)
 678                        p = string(p, pend, " pref", str_spec);
 679                if (res->flags & IORESOURCE_WINDOW)
 680                        p = string(p, pend, " window", str_spec);
 681                if (res->flags & IORESOURCE_DISABLED)
 682                        p = string(p, pend, " disabled", str_spec);
 683        } else {
 684                p = string(p, pend, " flags ", str_spec);
 685                p = number(p, pend, res->flags, flag_spec);
 686        }
 687        *p++ = ']';
 688        *p = '\0';
 689
 690        return string(buf, end, sym, spec);
 691}
 692
 693static char *mac_address_string(char *buf, char *end, u8 *addr,
 694                                struct printf_spec spec, const char *fmt)
 695{
 696        char mac_addr[sizeof("xx:xx:xx:xx:xx:xx")];
 697        char *p = mac_addr;
 698        int i;
 699        char separator;
 700
 701        if (fmt[1] == 'F') {            /* FDDI canonical format */
 702                separator = '-';
 703        } else {
 704                separator = ':';
 705        }
 706
 707        for (i = 0; i < 6; i++) {
 708                p = pack_hex_byte(p, addr[i]);
 709                if (fmt[0] == 'M' && i != 5)
 710                        *p++ = separator;
 711        }
 712        *p = '\0';
 713
 714        return string(buf, end, mac_addr, spec);
 715}
 716
 717static char *ip4_string(char *p, const u8 *addr, const char *fmt)
 718{
 719        int i;
 720        bool leading_zeros = (fmt[0] == 'i');
 721        int index;
 722        int step;
 723
 724        switch (fmt[2]) {
 725        case 'h':
 726#ifdef __BIG_ENDIAN
 727                index = 0;
 728                step = 1;
 729#else
 730                index = 3;
 731                step = -1;
 732#endif
 733                break;
 734        case 'l':
 735                index = 3;
 736                step = -1;
 737                break;
 738        case 'n':
 739        case 'b':
 740        default:
 741                index = 0;
 742                step = 1;
 743                break;
 744        }
 745        for (i = 0; i < 4; i++) {
 746                char temp[3];   /* hold each IP quad in reverse order */
 747                int digits = put_dec_trunc(temp, addr[index]) - temp;
 748                if (leading_zeros) {
 749                        if (digits < 3)
 750                                *p++ = '0';
 751                        if (digits < 2)
 752                                *p++ = '0';
 753                }
 754                /* reverse the digits in the quad */
 755                while (digits--)
 756                        *p++ = temp[digits];
 757                if (i < 3)
 758                        *p++ = '.';
 759                index += step;
 760        }
 761        *p = '\0';
 762
 763        return p;
 764}
 765
 766static char *ip6_compressed_string(char *p, const char *addr)
 767{
 768        int i, j, range;
 769        unsigned char zerolength[8];
 770        int longest = 1;
 771        int colonpos = -1;
 772        u16 word;
 773        u8 hi, lo;
 774        bool needcolon = false;
 775        bool useIPv4;
 776        struct in6_addr in6;
 777
 778        memcpy(&in6, addr, sizeof(struct in6_addr));
 779
 780        useIPv4 = ipv6_addr_v4mapped(&in6) || ipv6_addr_is_isatap(&in6);
 781
 782        memset(zerolength, 0, sizeof(zerolength));
 783
 784        if (useIPv4)
 785                range = 6;
 786        else
 787                range = 8;
 788
 789        /* find position of longest 0 run */
 790        for (i = 0; i < range; i++) {
 791                for (j = i; j < range; j++) {
 792                        if (in6.s6_addr16[j] != 0)
 793                                break;
 794                        zerolength[i]++;
 795                }
 796        }
 797        for (i = 0; i < range; i++) {
 798                if (zerolength[i] > longest) {
 799                        longest = zerolength[i];
 800                        colonpos = i;
 801                }
 802        }
 803
 804        /* emit address */
 805        for (i = 0; i < range; i++) {
 806                if (i == colonpos) {
 807                        if (needcolon || i == 0)
 808                                *p++ = ':';
 809                        *p++ = ':';
 810                        needcolon = false;
 811                        i += longest - 1;
 812                        continue;
 813                }
 814                if (needcolon) {
 815                        *p++ = ':';
 816                        needcolon = false;
 817                }
 818                /* hex u16 without leading 0s */
 819                word = ntohs(in6.s6_addr16[i]);
 820                hi = word >> 8;
 821                lo = word & 0xff;
 822                if (hi) {
 823                        if (hi > 0x0f)
 824                                p = pack_hex_byte(p, hi);
 825                        else
 826                                *p++ = hex_asc_lo(hi);
 827                        p = pack_hex_byte(p, lo);
 828                }
 829                else if (lo > 0x0f)
 830                        p = pack_hex_byte(p, lo);
 831                else
 832                        *p++ = hex_asc_lo(lo);
 833                needcolon = true;
 834        }
 835
 836        if (useIPv4) {
 837                if (needcolon)
 838                        *p++ = ':';
 839                p = ip4_string(p, &in6.s6_addr[12], "I4");
 840        }
 841        *p = '\0';
 842
 843        return p;
 844}
 845
 846static char *ip6_string(char *p, const char *addr, const char *fmt)
 847{
 848        int i;
 849
 850        for (i = 0; i < 8; i++) {
 851                p = pack_hex_byte(p, *addr++);
 852                p = pack_hex_byte(p, *addr++);
 853                if (fmt[0] == 'I' && i != 7)
 854                        *p++ = ':';
 855        }
 856        *p = '\0';
 857
 858        return p;
 859}
 860
 861static char *ip6_addr_string(char *buf, char *end, const u8 *addr,
 862                             struct printf_spec spec, const char *fmt)
 863{
 864        char ip6_addr[sizeof("xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255")];
 865
 866        if (fmt[0] == 'I' && fmt[2] == 'c')
 867                ip6_compressed_string(ip6_addr, addr);
 868        else
 869                ip6_string(ip6_addr, addr, fmt);
 870
 871        return string(buf, end, ip6_addr, spec);
 872}
 873
 874static char *ip4_addr_string(char *buf, char *end, const u8 *addr,
 875                             struct printf_spec spec, const char *fmt)
 876{
 877        char ip4_addr[sizeof("255.255.255.255")];
 878
 879        ip4_string(ip4_addr, addr, fmt);
 880
 881        return string(buf, end, ip4_addr, spec);
 882}
 883
 884static char *uuid_string(char *buf, char *end, const u8 *addr,
 885                         struct printf_spec spec, const char *fmt)
 886{
 887        char uuid[sizeof("xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx")];
 888        char *p = uuid;
 889        int i;
 890        static const u8 be[16] = {0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15};
 891        static const u8 le[16] = {3,2,1,0,5,4,7,6,8,9,10,11,12,13,14,15};
 892        const u8 *index = be;
 893        bool uc = false;
 894
 895        switch (*(++fmt)) {
 896        case 'L':
 897                uc = true;              /* fall-through */
 898        case 'l':
 899                index = le;
 900                break;
 901        case 'B':
 902                uc = true;
 903                break;
 904        }
 905
 906        for (i = 0; i < 16; i++) {
 907                p = pack_hex_byte(p, addr[index[i]]);
 908                switch (i) {
 909                case 3:
 910                case 5:
 911                case 7:
 912                case 9:
 913                        *p++ = '-';
 914                        break;
 915                }
 916        }
 917
 918        *p = 0;
 919
 920        if (uc) {
 921                p = uuid;
 922                do {
 923                        *p = toupper(*p);
 924                } while (*(++p));
 925        }
 926
 927        return string(buf, end, uuid, spec);
 928}
 929
 930/*
 931 * Show a '%p' thing.  A kernel extension is that the '%p' is followed
 932 * by an extra set of alphanumeric characters that are extended format
 933 * specifiers.
 934 *
 935 * Right now we handle:
 936 *
 937 * - 'F' For symbolic function descriptor pointers with offset
 938 * - 'f' For simple symbolic function names without offset
 939 * - 'S' For symbolic direct pointers with offset
 940 * - 's' For symbolic direct pointers without offset
 941 * - 'R' For decoded struct resource, e.g., [mem 0x0-0x1f 64bit pref]
 942 * - 'r' For raw struct resource, e.g., [mem 0x0-0x1f flags 0x201]
 943 * - 'M' For a 6-byte MAC address, it prints the address in the
 944 *       usual colon-separated hex notation
 945 * - 'm' For a 6-byte MAC address, it prints the hex address without colons
 946 * - 'MF' For a 6-byte MAC FDDI address, it prints the address
 947 *       with a dash-separated hex notation
 948 * - 'I' [46] for IPv4/IPv6 addresses printed in the usual way
 949 *       IPv4 uses dot-separated decimal without leading 0's (1.2.3.4)
 950 *       IPv6 uses colon separated network-order 16 bit hex with leading 0's
 951 * - 'i' [46] for 'raw' IPv4/IPv6 addresses
 952 *       IPv6 omits the colons (01020304...0f)
 953 *       IPv4 uses dot-separated decimal with leading 0's (010.123.045.006)
 954 * - '[Ii]4[hnbl]' IPv4 addresses in host, network, big or little endian order
 955 * - 'I6c' for IPv6 addresses printed as specified by
 956 *       http://tools.ietf.org/html/draft-ietf-6man-text-addr-representation-00
 957 * - 'U' For a 16 byte UUID/GUID, it prints the UUID/GUID in the form
 958 *       "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx"
 959 *       Options for %pU are:
 960 *         b big endian lower case hex (default)
 961 *         B big endian UPPER case hex
 962 *         l little endian lower case hex
 963 *         L little endian UPPER case hex
 964 *           big endian output byte order is:
 965 *             [0][1][2][3]-[4][5]-[6][7]-[8][9]-[10][11][12][13][14][15]
 966 *           little endian output byte order is:
 967 *             [3][2][1][0]-[5][4]-[7][6]-[8][9]-[10][11][12][13][14][15]
 968 *
 969 * Note: The difference between 'S' and 'F' is that on ia64 and ppc64
 970 * function pointers are really function descriptors, which contain a
 971 * pointer to the real address.
 972 */
 973static char *pointer(const char *fmt, char *buf, char *end, void *ptr,
 974                        struct printf_spec spec)
 975{
 976        if (!ptr)
 977                return string(buf, end, "(null)", spec);
 978
 979        switch (*fmt) {
 980        case 'F':
 981        case 'f':
 982                ptr = dereference_function_descriptor(ptr);
 983                /* Fallthrough */
 984        case 'S':
 985        case 's':
 986                return symbol_string(buf, end, ptr, spec, *fmt);
 987        case 'R':
 988        case 'r':
 989                return resource_string(buf, end, ptr, spec, fmt);
 990        case 'M':                       /* Colon separated: 00:01:02:03:04:05 */
 991        case 'm':                       /* Contiguous: 000102030405 */
 992                                        /* [mM]F (FDDI, bit reversed) */
 993                return mac_address_string(buf, end, ptr, spec, fmt);
 994        case 'I':                       /* Formatted IP supported
 995                                         * 4:   1.2.3.4
 996                                         * 6:   0001:0203:...:0708
 997                                         * 6c:  1::708 or 1::1.2.3.4
 998                                         */
 999        case 'i':                       /* Contiguous:
1000                                         * 4:   001.002.003.004
1001                                         * 6:   000102...0f
1002                                         */
1003                switch (fmt[1]) {
1004                case '6':
1005                        return ip6_addr_string(buf, end, ptr, spec, fmt);
1006                case '4':
1007                        return ip4_addr_string(buf, end, ptr, spec, fmt);
1008                }
1009                break;
1010        case 'U':
1011                return uuid_string(buf, end, ptr, spec, fmt);
1012        }
1013        spec.flags |= SMALL;
1014        if (spec.field_width == -1) {
1015                spec.field_width = 2*sizeof(void *);
1016                spec.flags |= ZEROPAD;
1017        }
1018        spec.base = 16;
1019
1020        return number(buf, end, (unsigned long) ptr, spec);
1021}
1022
1023/*
1024 * Helper function to decode printf style format.
1025 * Each call decode a token from the format and return the
1026 * number of characters read (or likely the delta where it wants
1027 * to go on the next call).
1028 * The decoded token is returned through the parameters
1029 *
1030 * 'h', 'l', or 'L' for integer fields
1031 * 'z' support added 23/7/1999 S.H.
1032 * 'z' changed to 'Z' --davidm 1/25/99
1033 * 't' added for ptrdiff_t
1034 *
1035 * @fmt: the format string
1036 * @type of the token returned
1037 * @flags: various flags such as +, -, # tokens..
1038 * @field_width: overwritten width
1039 * @base: base of the number (octal, hex, ...)
1040 * @precision: precision of a number
1041 * @qualifier: qualifier of a number (long, size_t, ...)
1042 */
1043static int format_decode(const char *fmt, struct printf_spec *spec)
1044{
1045        const char *start = fmt;
1046
1047        /* we finished early by reading the field width */
1048        if (spec->type == FORMAT_TYPE_WIDTH) {
1049                if (spec->field_width < 0) {
1050                        spec->field_width = -spec->field_width;
1051                        spec->flags |= LEFT;
1052                }
1053                spec->type = FORMAT_TYPE_NONE;
1054                goto precision;
1055        }
1056
1057        /* we finished early by reading the precision */
1058        if (spec->type == FORMAT_TYPE_PRECISION) {
1059                if (spec->precision < 0)
1060                        spec->precision = 0;
1061
1062                spec->type = FORMAT_TYPE_NONE;
1063                goto qualifier;
1064        }
1065
1066        /* By default */
1067        spec->type = FORMAT_TYPE_NONE;
1068
1069        for (; *fmt ; ++fmt) {
1070                if (*fmt == '%')
1071                        break;
1072        }
1073
1074        /* Return the current non-format string */
1075        if (fmt != start || !*fmt)
1076                return fmt - start;
1077
1078        /* Process flags */
1079        spec->flags = 0;
1080
1081        while (1) { /* this also skips first '%' */
1082                bool found = true;
1083
1084                ++fmt;
1085
1086                switch (*fmt) {
1087                case '-': spec->flags |= LEFT;    break;
1088                case '+': spec->flags |= PLUS;    break;
1089                case ' ': spec->flags |= SPACE;   break;
1090                case '#': spec->flags |= SPECIAL; break;
1091                case '0': spec->flags |= ZEROPAD; break;
1092                default:  found = false;
1093                }
1094
1095                if (!found)
1096                        break;
1097        }
1098
1099        /* get field width */
1100        spec->field_width = -1;
1101
1102        if (isdigit(*fmt))
1103                spec->field_width = skip_atoi(&fmt);
1104        else if (*fmt == '*') {
1105                /* it's the next argument */
1106                spec->type = FORMAT_TYPE_WIDTH;
1107                return ++fmt - start;
1108        }
1109
1110precision:
1111        /* get the precision */
1112        spec->precision = -1;
1113        if (*fmt == '.') {
1114                ++fmt;
1115                if (isdigit(*fmt)) {
1116                        spec->precision = skip_atoi(&fmt);
1117                        if (spec->precision < 0)
1118                                spec->precision = 0;
1119                } else if (*fmt == '*') {
1120                        /* it's the next argument */
1121                        spec->type = FORMAT_TYPE_PRECISION;
1122                        return ++fmt - start;
1123                }
1124        }
1125
1126qualifier:
1127        /* get the conversion qualifier */
1128        spec->qualifier = -1;
1129        if (*fmt == 'h' || TOLOWER(*fmt) == 'l' ||
1130            TOLOWER(*fmt) == 'z' || *fmt == 't') {
1131                spec->qualifier = *fmt++;
1132                if (unlikely(spec->qualifier == *fmt)) {
1133                        if (spec->qualifier == 'l') {
1134                                spec->qualifier = 'L';
1135                                ++fmt;
1136                        } else if (spec->qualifier == 'h') {
1137                                spec->qualifier = 'H';
1138                                ++fmt;
1139                        }
1140                }
1141        }
1142
1143        /* default base */
1144        spec->base = 10;
1145        switch (*fmt) {
1146        case 'c':
1147                spec->type = FORMAT_TYPE_CHAR;
1148                return ++fmt - start;
1149
1150        case 's':
1151                spec->type = FORMAT_TYPE_STR;
1152                return ++fmt - start;
1153
1154        case 'p':
1155                spec->type = FORMAT_TYPE_PTR;
1156                return fmt - start;
1157                /* skip alnum */
1158
1159        case 'n':
1160                spec->type = FORMAT_TYPE_NRCHARS;
1161                return ++fmt - start;
1162
1163        case '%':
1164                spec->type = FORMAT_TYPE_PERCENT_CHAR;
1165                return ++fmt - start;
1166
1167        /* integer number formats - set up the flags and "break" */
1168        case 'o':
1169                spec->base = 8;
1170                break;
1171
1172        case 'x':
1173                spec->flags |= SMALL;
1174
1175        case 'X':
1176                spec->base = 16;
1177                break;
1178
1179        case 'd':
1180        case 'i':
1181                spec->flags |= SIGN;
1182        case 'u':
1183                break;
1184
1185        default:
1186                spec->type = FORMAT_TYPE_INVALID;
1187                return fmt - start;
1188        }
1189
1190        if (spec->qualifier == 'L')
1191                spec->type = FORMAT_TYPE_LONG_LONG;
1192        else if (spec->qualifier == 'l') {
1193                if (spec->flags & SIGN)
1194                        spec->type = FORMAT_TYPE_LONG;
1195                else
1196                        spec->type = FORMAT_TYPE_ULONG;
1197        } else if (TOLOWER(spec->qualifier) == 'z') {
1198                spec->type = FORMAT_TYPE_SIZE_T;
1199        } else if (spec->qualifier == 't') {
1200                spec->type = FORMAT_TYPE_PTRDIFF;
1201        } else if (spec->qualifier == 'H') {
1202                if (spec->flags & SIGN)
1203                        spec->type = FORMAT_TYPE_BYTE;
1204                else
1205                        spec->type = FORMAT_TYPE_UBYTE;
1206        } else if (spec->qualifier == 'h') {
1207                if (spec->flags & SIGN)
1208                        spec->type = FORMAT_TYPE_SHORT;
1209                else
1210                        spec->type = FORMAT_TYPE_USHORT;
1211        } else {
1212                if (spec->flags & SIGN)
1213                        spec->type = FORMAT_TYPE_INT;
1214                else
1215                        spec->type = FORMAT_TYPE_UINT;
1216        }
1217
1218        return ++fmt - start;
1219}
1220
1221/**
1222 * vsnprintf - Format a string and place it in a buffer
1223 * @buf: The buffer to place the result into
1224 * @size: The size of the buffer, including the trailing null space
1225 * @fmt: The format string to use
1226 * @args: Arguments for the format string
1227 *
1228 * This function follows C99 vsnprintf, but has some extensions:
1229 * %pS output the name of a text symbol with offset
1230 * %ps output the name of a text symbol without offset
1231 * %pF output the name of a function pointer with its offset
1232 * %pf output the name of a function pointer without its offset
1233 * %pR output the address range in a struct resource with decoded flags
1234 * %pr output the address range in a struct resource with raw flags
1235 * %pM output a 6-byte MAC address with colons
1236 * %pm output a 6-byte MAC address without colons
1237 * %pI4 print an IPv4 address without leading zeros
1238 * %pi4 print an IPv4 address with leading zeros
1239 * %pI6 print an IPv6 address with colons
1240 * %pi6 print an IPv6 address without colons
1241 * %pI6c print an IPv6 address as specified by
1242 *   http://tools.ietf.org/html/draft-ietf-6man-text-addr-representation-00
1243 * %pU[bBlL] print a UUID/GUID in big or little endian using lower or upper
1244 *   case.
1245 * %n is ignored
1246 *
1247 * The return value is the number of characters which would
1248 * be generated for the given input, excluding the trailing
1249 * '\0', as per ISO C99. If you want to have the exact
1250 * number of characters written into @buf as return value
1251 * (not including the trailing '\0'), use vscnprintf(). If the
1252 * return is greater than or equal to @size, the resulting
1253 * string is truncated.
1254 *
1255 * Call this function if you are already dealing with a va_list.
1256 * You probably want snprintf() instead.
1257 */
1258int vsnprintf(char *buf, size_t size, const char *fmt, va_list args)
1259{
1260        unsigned long long num;
1261        char *str, *end;
1262        struct printf_spec spec = {0};
1263
1264        /* Reject out-of-range values early.  Large positive sizes are
1265           used for unknown buffer sizes. */
1266        if (WARN_ON_ONCE((int) size < 0))
1267                return 0;
1268
1269        str = buf;
1270        end = buf + size;
1271
1272        /* Make sure end is always >= buf */
1273        if (end < buf) {
1274                end = ((void *)-1);
1275                size = end - buf;
1276        }
1277
1278        while (*fmt) {
1279                const char *old_fmt = fmt;
1280                int read = format_decode(fmt, &spec);
1281
1282                fmt += read;
1283
1284                switch (spec.type) {
1285                case FORMAT_TYPE_NONE: {
1286                        int copy = read;
1287                        if (str < end) {
1288                                if (copy > end - str)
1289                                        copy = end - str;
1290                                memcpy(str, old_fmt, copy);
1291                        }
1292                        str += read;
1293                        break;
1294                }
1295
1296                case FORMAT_TYPE_WIDTH:
1297                        spec.field_width = va_arg(args, int);
1298                        break;
1299
1300                case FORMAT_TYPE_PRECISION:
1301                        spec.precision = va_arg(args, int);
1302                        break;
1303
1304                case FORMAT_TYPE_CHAR: {
1305                        char c;
1306
1307                        if (!(spec.flags & LEFT)) {
1308                                while (--spec.field_width > 0) {
1309                                        if (str < end)
1310                                                *str = ' ';
1311                                        ++str;
1312
1313                                }
1314                        }
1315                        c = (unsigned char) va_arg(args, int);
1316                        if (str < end)
1317                                *str = c;
1318                        ++str;
1319                        while (--spec.field_width > 0) {
1320                                if (str < end)
1321                                        *str = ' ';
1322                                ++str;
1323                        }
1324                        break;
1325                }
1326
1327                case FORMAT_TYPE_STR:
1328                        str = string(str, end, va_arg(args, char *), spec);
1329                        break;
1330
1331                case FORMAT_TYPE_PTR:
1332                        str = pointer(fmt+1, str, end, va_arg(args, void *),
1333                                      spec);
1334                        while (isalnum(*fmt))
1335                                fmt++;
1336                        break;
1337
1338                case FORMAT_TYPE_PERCENT_CHAR:
1339                        if (str < end)
1340                                *str = '%';
1341                        ++str;
1342                        break;
1343
1344                case FORMAT_TYPE_INVALID:
1345                        if (str < end)
1346                                *str = '%';
1347                        ++str;
1348                        break;
1349
1350                case FORMAT_TYPE_NRCHARS: {
1351                        u8 qualifier = spec.qualifier;
1352
1353                        if (qualifier == 'l') {
1354                                long *ip = va_arg(args, long *);
1355                                *ip = (str - buf);
1356                        } else if (TOLOWER(qualifier) == 'z') {
1357                                size_t *ip = va_arg(args, size_t *);
1358                                *ip = (str - buf);
1359                        } else {
1360                                int *ip = va_arg(args, int *);
1361                                *ip = (str - buf);
1362                        }
1363                        break;
1364                }
1365
1366                default:
1367                        switch (spec.type) {
1368                        case FORMAT_TYPE_LONG_LONG:
1369                                num = va_arg(args, long long);
1370                                break;
1371                        case FORMAT_TYPE_ULONG:
1372                                num = va_arg(args, unsigned long);
1373                                break;
1374                        case FORMAT_TYPE_LONG:
1375                                num = va_arg(args, long);
1376                                break;
1377                        case FORMAT_TYPE_SIZE_T:
1378                                num = va_arg(args, size_t);
1379                                break;
1380                        case FORMAT_TYPE_PTRDIFF:
1381                                num = va_arg(args, ptrdiff_t);
1382                                break;
1383                        case FORMAT_TYPE_UBYTE:
1384                                num = (unsigned char) va_arg(args, int);
1385                                break;
1386                        case FORMAT_TYPE_BYTE:
1387                                num = (signed char) va_arg(args, int);
1388                                break;
1389                        case FORMAT_TYPE_USHORT:
1390                                num = (unsigned short) va_arg(args, int);
1391                                break;
1392                        case FORMAT_TYPE_SHORT:
1393                                num = (short) va_arg(args, int);
1394                                break;
1395                        case FORMAT_TYPE_INT:
1396                                num = (int) va_arg(args, int);
1397                                break;
1398                        default:
1399                                num = va_arg(args, unsigned int);
1400                        }
1401
1402                        str = number(str, end, num, spec);
1403                }
1404        }
1405
1406        if (size > 0) {
1407                if (str < end)
1408                        *str = '\0';
1409                else
1410                        end[-1] = '\0';
1411        }
1412
1413        /* the trailing null byte doesn't count towards the total */
1414        return str-buf;
1415
1416}
1417EXPORT_SYMBOL(vsnprintf);
1418
1419/**
1420 * vscnprintf - Format a string and place it in a buffer
1421 * @buf: The buffer to place the result into
1422 * @size: The size of the buffer, including the trailing null space
1423 * @fmt: The format string to use
1424 * @args: Arguments for the format string
1425 *
1426 * The return value is the number of characters which have been written into
1427 * the @buf not including the trailing '\0'. If @size is <= 0 the function
1428 * returns 0.
1429 *
1430 * Call this function if you are already dealing with a va_list.
1431 * You probably want scnprintf() instead.
1432 *
1433 * See the vsnprintf() documentation for format string extensions over C99.
1434 */
1435int vscnprintf(char *buf, size_t size, const char *fmt, va_list args)
1436{
1437        int i;
1438
1439        i = vsnprintf(buf, size, fmt, args);
1440
1441        return (i >= size) ? (size - 1) : i;
1442}
1443EXPORT_SYMBOL(vscnprintf);
1444
1445/**
1446 * snprintf - Format a string and place it in a buffer
1447 * @buf: The buffer to place the result into
1448 * @size: The size of the buffer, including the trailing null space
1449 * @fmt: The format string to use
1450 * @...: Arguments for the format string
1451 *
1452 * The return value is the number of characters which would be
1453 * generated for the given input, excluding the trailing null,
1454 * as per ISO C99.  If the return is greater than or equal to
1455 * @size, the resulting string is truncated.
1456 *
1457 * See the vsnprintf() documentation for format string extensions over C99.
1458 */
1459int snprintf(char *buf, size_t size, const char *fmt, ...)
1460{
1461        va_list args;
1462        int i;
1463
1464        va_start(args, fmt);
1465        i = vsnprintf(buf, size, fmt, args);
1466        va_end(args);
1467
1468        return i;
1469}
1470EXPORT_SYMBOL(snprintf);
1471
1472/**
1473 * scnprintf - Format a string and place it in a buffer
1474 * @buf: The buffer to place the result into
1475 * @size: The size of the buffer, including the trailing null space
1476 * @fmt: The format string to use
1477 * @...: Arguments for the format string
1478 *
1479 * The return value is the number of characters written into @buf not including
1480 * the trailing '\0'. If @size is <= 0 the function returns 0.
1481 */
1482
1483int scnprintf(char *buf, size_t size, const char *fmt, ...)
1484{
1485        va_list args;
1486        int i;
1487
1488        va_start(args, fmt);
1489        i = vsnprintf(buf, size, fmt, args);
1490        va_end(args);
1491
1492        return (i >= size) ? (size - 1) : i;
1493}
1494EXPORT_SYMBOL(scnprintf);
1495
1496/**
1497 * vsprintf - Format a string and place it in a buffer
1498 * @buf: The buffer to place the result into
1499 * @fmt: The format string to use
1500 * @args: Arguments for the format string
1501 *
1502 * The function returns the number of characters written
1503 * into @buf. Use vsnprintf() or vscnprintf() in order to avoid
1504 * buffer overflows.
1505 *
1506 * Call this function if you are already dealing with a va_list.
1507 * You probably want sprintf() instead.
1508 *
1509 * See the vsnprintf() documentation for format string extensions over C99.
1510 */
1511int vsprintf(char *buf, const char *fmt, va_list args)
1512{
1513        return vsnprintf(buf, INT_MAX, fmt, args);
1514}
1515EXPORT_SYMBOL(vsprintf);
1516
1517/**
1518 * sprintf - Format a string and place it in a buffer
1519 * @buf: The buffer to place the result into
1520 * @fmt: The format string to use
1521 * @...: Arguments for the format string
1522 *
1523 * The function returns the number of characters written
1524 * into @buf. Use snprintf() or scnprintf() in order to avoid
1525 * buffer overflows.
1526 *
1527 * See the vsnprintf() documentation for format string extensions over C99.
1528 */
1529int sprintf(char *buf, const char *fmt, ...)
1530{
1531        va_list args;
1532        int i;
1533
1534        va_start(args, fmt);
1535        i = vsnprintf(buf, INT_MAX, fmt, args);
1536        va_end(args);
1537
1538        return i;
1539}
1540EXPORT_SYMBOL(sprintf);
1541
1542#ifdef CONFIG_BINARY_PRINTF
1543/*
1544 * bprintf service:
1545 * vbin_printf() - VA arguments to binary data
1546 * bstr_printf() - Binary data to text string
1547 */
1548
1549/**
1550 * vbin_printf - Parse a format string and place args' binary value in a buffer
1551 * @bin_buf: The buffer to place args' binary value
1552 * @size: The size of the buffer(by words(32bits), not characters)
1553 * @fmt: The format string to use
1554 * @args: Arguments for the format string
1555 *
1556 * The format follows C99 vsnprintf, except %n is ignored, and its argument
1557 * is skiped.
1558 *
1559 * The return value is the number of words(32bits) which would be generated for
1560 * the given input.
1561 *
1562 * NOTE:
1563 * If the return value is greater than @size, the resulting bin_buf is NOT
1564 * valid for bstr_printf().
1565 */
1566int vbin_printf(u32 *bin_buf, size_t size, const char *fmt, va_list args)
1567{
1568        struct printf_spec spec = {0};
1569        char *str, *end;
1570
1571        str = (char *)bin_buf;
1572        end = (char *)(bin_buf + size);
1573
1574#define save_arg(type)                                                  \
1575do {                                                                    \
1576        if (sizeof(type) == 8) {                                        \
1577                unsigned long long value;                               \
1578                str = PTR_ALIGN(str, sizeof(u32));                      \
1579                value = va_arg(args, unsigned long long);               \
1580                if (str + sizeof(type) <= end) {                        \
1581                        *(u32 *)str = *(u32 *)&value;                   \
1582                        *(u32 *)(str + 4) = *((u32 *)&value + 1);       \
1583                }                                                       \
1584        } else {                                                        \
1585                unsigned long value;                                    \
1586                str = PTR_ALIGN(str, sizeof(type));                     \
1587                value = va_arg(args, int);                              \
1588                if (str + sizeof(type) <= end)                          \
1589                        *(typeof(type) *)str = (type)value;             \
1590        }                                                               \
1591        str += sizeof(type);                                            \
1592} while (0)
1593
1594        while (*fmt) {
1595                int read = format_decode(fmt, &spec);
1596
1597                fmt += read;
1598
1599                switch (spec.type) {
1600                case FORMAT_TYPE_NONE:
1601                case FORMAT_TYPE_INVALID:
1602                case FORMAT_TYPE_PERCENT_CHAR:
1603                        break;
1604
1605                case FORMAT_TYPE_WIDTH:
1606                case FORMAT_TYPE_PRECISION:
1607                        save_arg(int);
1608                        break;
1609
1610                case FORMAT_TYPE_CHAR:
1611                        save_arg(char);
1612                        break;
1613
1614                case FORMAT_TYPE_STR: {
1615                        const char *save_str = va_arg(args, char *);
1616                        size_t len;
1617
1618                        if ((unsigned long)save_str > (unsigned long)-PAGE_SIZE
1619                                        || (unsigned long)save_str < PAGE_SIZE)
1620                                save_str = "(null)";
1621                        len = strlen(save_str) + 1;
1622                        if (str + len < end)
1623                                memcpy(str, save_str, len);
1624                        str += len;
1625                        break;
1626                }
1627
1628                case FORMAT_TYPE_PTR:
1629                        save_arg(void *);
1630                        /* skip all alphanumeric pointer suffixes */
1631                        while (isalnum(*fmt))
1632                                fmt++;
1633                        break;
1634
1635                case FORMAT_TYPE_NRCHARS: {
1636                        /* skip %n 's argument */
1637                        u8 qualifier = spec.qualifier;
1638                        void *skip_arg;
1639                        if (qualifier == 'l')
1640                                skip_arg = va_arg(args, long *);
1641                        else if (TOLOWER(qualifier) == 'z')
1642                                skip_arg = va_arg(args, size_t *);
1643                        else
1644                                skip_arg = va_arg(args, int *);
1645                        break;
1646                }
1647
1648                default:
1649                        switch (spec.type) {
1650
1651                        case FORMAT_TYPE_LONG_LONG:
1652                                save_arg(long long);
1653                                break;
1654                        case FORMAT_TYPE_ULONG:
1655                        case FORMAT_TYPE_LONG:
1656                                save_arg(unsigned long);
1657                                break;
1658                        case FORMAT_TYPE_SIZE_T:
1659                                save_arg(size_t);
1660                                break;
1661                        case FORMAT_TYPE_PTRDIFF:
1662                                save_arg(ptrdiff_t);
1663                                break;
1664                        case FORMAT_TYPE_UBYTE:
1665                        case FORMAT_TYPE_BYTE:
1666                                save_arg(char);
1667                                break;
1668                        case FORMAT_TYPE_USHORT:
1669                        case FORMAT_TYPE_SHORT:
1670                                save_arg(short);
1671                                break;
1672                        default:
1673                                save_arg(int);
1674                        }
1675                }
1676        }
1677
1678        return (u32 *)(PTR_ALIGN(str, sizeof(u32))) - bin_buf;
1679#undef save_arg
1680}
1681EXPORT_SYMBOL_GPL(vbin_printf);
1682
1683/**
1684 * bstr_printf - Format a string from binary arguments and place it in a buffer
1685 * @buf: The buffer to place the result into
1686 * @size: The size of the buffer, including the trailing null space
1687 * @fmt: The format string to use
1688 * @bin_buf: Binary arguments for the format string
1689 *
1690 * This function like C99 vsnprintf, but the difference is that vsnprintf gets
1691 * arguments from stack, and bstr_printf gets arguments from @bin_buf which is
1692 * a binary buffer that generated by vbin_printf.
1693 *
1694 * The format follows C99 vsnprintf, but has some extensions:
1695 *  see vsnprintf comment for details.
1696 *
1697 * The return value is the number of characters which would
1698 * be generated for the given input, excluding the trailing
1699 * '\0', as per ISO C99. If you want to have the exact
1700 * number of characters written into @buf as return value
1701 * (not including the trailing '\0'), use vscnprintf(). If the
1702 * return is greater than or equal to @size, the resulting
1703 * string is truncated.
1704 */
1705int bstr_printf(char *buf, size_t size, const char *fmt, const u32 *bin_buf)
1706{
1707        struct printf_spec spec = {0};
1708        char *str, *end;
1709        const char *args = (const char *)bin_buf;
1710
1711        if (WARN_ON_ONCE((int) size < 0))
1712                return 0;
1713
1714        str = buf;
1715        end = buf + size;
1716
1717#define get_arg(type)                                                   \
1718({                                                                      \
1719        typeof(type) value;                                             \
1720        if (sizeof(type) == 8) {                                        \
1721                args = PTR_ALIGN(args, sizeof(u32));                    \
1722                *(u32 *)&value = *(u32 *)args;                          \
1723                *((u32 *)&value + 1) = *(u32 *)(args + 4);              \
1724        } else {                                                        \
1725                args = PTR_ALIGN(args, sizeof(type));                   \
1726                value = *(typeof(type) *)args;                          \
1727        }                                                               \
1728        args += sizeof(type);                                           \
1729        value;                                                          \
1730})
1731
1732        /* Make sure end is always >= buf */
1733        if (end < buf) {
1734                end = ((void *)-1);
1735                size = end - buf;
1736        }
1737
1738        while (*fmt) {
1739                const char *old_fmt = fmt;
1740                int read = format_decode(fmt, &spec);
1741
1742                fmt += read;
1743
1744                switch (spec.type) {
1745                case FORMAT_TYPE_NONE: {
1746                        int copy = read;
1747                        if (str < end) {
1748                                if (copy > end - str)
1749                                        copy = end - str;
1750                                memcpy(str, old_fmt, copy);
1751                        }
1752                        str += read;
1753                        break;
1754                }
1755
1756                case FORMAT_TYPE_WIDTH:
1757                        spec.field_width = get_arg(int);
1758                        break;
1759
1760                case FORMAT_TYPE_PRECISION:
1761                        spec.precision = get_arg(int);
1762                        break;
1763
1764                case FORMAT_TYPE_CHAR: {
1765                        char c;
1766
1767                        if (!(spec.flags & LEFT)) {
1768                                while (--spec.field_width > 0) {
1769                                        if (str < end)
1770                                                *str = ' ';
1771                                        ++str;
1772                                }
1773                        }
1774                        c = (unsigned char) get_arg(char);
1775                        if (str < end)
1776                                *str = c;
1777                        ++str;
1778                        while (--spec.field_width > 0) {
1779                                if (str < end)
1780                                        *str = ' ';
1781                                ++str;
1782                        }
1783                        break;
1784                }
1785
1786                case FORMAT_TYPE_STR: {
1787                        const char *str_arg = args;
1788                        args += strlen(str_arg) + 1;
1789                        str = string(str, end, (char *)str_arg, spec);
1790                        break;
1791                }
1792
1793                case FORMAT_TYPE_PTR:
1794                        str = pointer(fmt+1, str, end, get_arg(void *), spec);
1795                        while (isalnum(*fmt))
1796                                fmt++;
1797                        break;
1798
1799                case FORMAT_TYPE_PERCENT_CHAR:
1800                case FORMAT_TYPE_INVALID:
1801                        if (str < end)
1802                                *str = '%';
1803                        ++str;
1804                        break;
1805
1806                case FORMAT_TYPE_NRCHARS:
1807                        /* skip */
1808                        break;
1809
1810                default: {
1811                        unsigned long long num;
1812
1813                        switch (spec.type) {
1814
1815                        case FORMAT_TYPE_LONG_LONG:
1816                                num = get_arg(long long);
1817                                break;
1818                        case FORMAT_TYPE_ULONG:
1819                        case FORMAT_TYPE_LONG:
1820                                num = get_arg(unsigned long);
1821                                break;
1822                        case FORMAT_TYPE_SIZE_T:
1823                                num = get_arg(size_t);
1824                                break;
1825                        case FORMAT_TYPE_PTRDIFF:
1826                                num = get_arg(ptrdiff_t);
1827                                break;
1828                        case FORMAT_TYPE_UBYTE:
1829                                num = get_arg(unsigned char);
1830                                break;
1831                        case FORMAT_TYPE_BYTE:
1832                                num = get_arg(signed char);
1833                                break;
1834                        case FORMAT_TYPE_USHORT:
1835                                num = get_arg(unsigned short);
1836                                break;
1837                        case FORMAT_TYPE_SHORT:
1838                                num = get_arg(short);
1839                                break;
1840                        case FORMAT_TYPE_UINT:
1841                                num = get_arg(unsigned int);
1842                                break;
1843                        default:
1844                                num = get_arg(int);
1845                        }
1846
1847                        str = number(str, end, num, spec);
1848                } /* default: */
1849                } /* switch(spec.type) */
1850        } /* while(*fmt) */
1851
1852        if (size > 0) {
1853                if (str < end)
1854                        *str = '\0';
1855                else
1856                        end[-1] = '\0';
1857        }
1858
1859#undef get_arg
1860
1861        /* the trailing null byte doesn't count towards the total */
1862        return str - buf;
1863}
1864EXPORT_SYMBOL_GPL(bstr_printf);
1865
1866/**
1867 * bprintf - Parse a format string and place args' binary value in a buffer
1868 * @bin_buf: The buffer to place args' binary value
1869 * @size: The size of the buffer(by words(32bits), not characters)
1870 * @fmt: The format string to use
1871 * @...: Arguments for the format string
1872 *
1873 * The function returns the number of words(u32) written
1874 * into @bin_buf.
1875 */
1876int bprintf(u32 *bin_buf, size_t size, const char *fmt, ...)
1877{
1878        va_list args;
1879        int ret;
1880
1881        va_start(args, fmt);
1882        ret = vbin_printf(bin_buf, size, fmt, args);
1883        va_end(args);
1884
1885        return ret;
1886}
1887EXPORT_SYMBOL_GPL(bprintf);
1888
1889#endif /* CONFIG_BINARY_PRINTF */
1890
1891/**
1892 * vsscanf - Unformat a buffer into a list of arguments
1893 * @buf:        input buffer
1894 * @fmt:        format of buffer
1895 * @args:       arguments
1896 */
1897int vsscanf(const char *buf, const char *fmt, va_list args)
1898{
1899        const char *str = buf;
1900        char *next;
1901        char digit;
1902        int num = 0;
1903        u8 qualifier;
1904        u8 base;
1905        s16 field_width;
1906        bool is_sign;
1907
1908        while (*fmt && *str) {
1909                /* skip any white space in format */
1910                /* white space in format matchs any amount of
1911                 * white space, including none, in the input.
1912                 */
1913                if (isspace(*fmt)) {
1914                        fmt = skip_spaces(++fmt);
1915                        str = skip_spaces(str);
1916                }
1917
1918                /* anything that is not a conversion must match exactly */
1919                if (*fmt != '%' && *fmt) {
1920                        if (*fmt++ != *str++)
1921                                break;
1922                        continue;
1923                }
1924
1925                if (!*fmt)
1926                        break;
1927                ++fmt;
1928
1929                /* skip this conversion.
1930                 * advance both strings to next white space
1931                 */
1932                if (*fmt == '*') {
1933                        while (!isspace(*fmt) && *fmt != '%' && *fmt)
1934                                fmt++;
1935                        while (!isspace(*str) && *str)
1936                                str++;
1937                        continue;
1938                }
1939
1940                /* get field width */
1941                field_width = -1;
1942                if (isdigit(*fmt))
1943                        field_width = skip_atoi(&fmt);
1944
1945                /* get conversion qualifier */
1946                qualifier = -1;
1947                if (*fmt == 'h' || TOLOWER(*fmt) == 'l' ||
1948                    TOLOWER(*fmt) == 'z') {
1949                        qualifier = *fmt++;
1950                        if (unlikely(qualifier == *fmt)) {
1951                                if (qualifier == 'h') {
1952                                        qualifier = 'H';
1953                                        fmt++;
1954                                } else if (qualifier == 'l') {
1955                                        qualifier = 'L';
1956                                        fmt++;
1957                                }
1958                        }
1959                }
1960
1961                if (!*fmt || !*str)
1962                        break;
1963
1964                base = 10;
1965                is_sign = 0;
1966
1967                switch (*fmt++) {
1968                case 'c':
1969                {
1970                        char *s = (char *)va_arg(args, char*);
1971                        if (field_width == -1)
1972                                field_width = 1;
1973                        do {
1974                                *s++ = *str++;
1975                        } while (--field_width > 0 && *str);
1976                        num++;
1977                }
1978                continue;
1979                case 's':
1980                {
1981                        char *s = (char *)va_arg(args, char *);
1982                        if (field_width == -1)
1983                                field_width = SHORT_MAX;
1984                        /* first, skip leading white space in buffer */
1985                        str = skip_spaces(str);
1986
1987                        /* now copy until next white space */
1988                        while (*str && !isspace(*str) && field_width--)
1989                                *s++ = *str++;
1990                        *s = '\0';
1991                        num++;
1992                }
1993                continue;
1994                case 'n':
1995                        /* return number of characters read so far */
1996                {
1997                        int *i = (int *)va_arg(args, int*);
1998                        *i = str - buf;
1999                }
2000                continue;
2001                case 'o':
2002                        base = 8;
2003                        break;
2004                case 'x':
2005                case 'X':
2006                        base = 16;
2007                        break;
2008                case 'i':
2009                        base = 0;
2010                case 'd':
2011                        is_sign = 1;
2012                case 'u':
2013                        break;
2014                case '%':
2015                        /* looking for '%' in str */
2016                        if (*str++ != '%')
2017                                return num;
2018                        continue;
2019                default:
2020                        /* invalid format; stop here */
2021                        return num;
2022                }
2023
2024                /* have some sort of integer conversion.
2025                 * first, skip white space in buffer.
2026                 */
2027                str = skip_spaces(str);
2028
2029                digit = *str;
2030                if (is_sign && digit == '-')
2031                        digit = *(str + 1);
2032
2033                if (!digit
2034                    || (base == 16 && !isxdigit(digit))
2035                    || (base == 10 && !isdigit(digit))
2036                    || (base == 8 && (!isdigit(digit) || digit > '7'))
2037                    || (base == 0 && !isdigit(digit)))
2038                        break;
2039
2040                switch (qualifier) {
2041                case 'H':       /* that's 'hh' in format */
2042                        if (is_sign) {
2043                                signed char *s = (signed char *)va_arg(args, signed char *);
2044                                *s = (signed char)simple_strtol(str, &next, base);
2045                        } else {
2046                                unsigned char *s = (unsigned char *)va_arg(args, unsigned char *);
2047                                *s = (unsigned char)simple_strtoul(str, &next, base);
2048                        }
2049                        break;
2050                case 'h':
2051                        if (is_sign) {
2052                                short *s = (short *)va_arg(args, short *);
2053                                *s = (short)simple_strtol(str, &next, base);
2054                        } else {
2055                                unsigned short *s = (unsigned short *)va_arg(args, unsigned short *);
2056                                *s = (unsigned short)simple_strtoul(str, &next, base);
2057                        }
2058                        break;
2059                case 'l':
2060                        if (is_sign) {
2061                                long *l = (long *)va_arg(args, long *);
2062                                *l = simple_strtol(str, &next, base);
2063                        } else {
2064                                unsigned long *l = (unsigned long *)va_arg(args, unsigned long *);
2065                                *l = simple_strtoul(str, &next, base);
2066                        }
2067                        break;
2068                case 'L':
2069                        if (is_sign) {
2070                                long long *l = (long long *)va_arg(args, long long *);
2071                                *l = simple_strtoll(str, &next, base);
2072                        } else {
2073                                unsigned long long *l = (unsigned long long *)va_arg(args, unsigned long long *);
2074                                *l = simple_strtoull(str, &next, base);
2075                        }
2076                        break;
2077                case 'Z':
2078                case 'z':
2079                {
2080                        size_t *s = (size_t *)va_arg(args, size_t *);
2081                        *s = (size_t)simple_strtoul(str, &next, base);
2082                }
2083                break;
2084                default:
2085                        if (is_sign) {
2086                                int *i = (int *)va_arg(args, int *);
2087                                *i = (int)simple_strtol(str, &next, base);
2088                        } else {
2089                                unsigned int *i = (unsigned int *)va_arg(args, unsigned int*);
2090                                *i = (unsigned int)simple_strtoul(str, &next, base);
2091                        }
2092                        break;
2093                }
2094                num++;
2095
2096                if (!next)
2097                        break;
2098                str = next;
2099        }
2100
2101        /*
2102         * Now we've come all the way through so either the input string or the
2103         * format ended. In the former case, there can be a %n at the current
2104         * position in the format that needs to be filled.
2105         */
2106        if (*fmt == '%' && *(fmt + 1) == 'n') {
2107                int *p = (int *)va_arg(args, int *);
2108                *p = str - buf;
2109        }
2110
2111        return num;
2112}
2113EXPORT_SYMBOL(vsscanf);
2114
2115/**
2116 * sscanf - Unformat a buffer into a list of arguments
2117 * @buf:        input buffer
2118 * @fmt:        formatting of buffer
2119 * @...:        resulting arguments
2120 */
2121int sscanf(const char *buf, const char *fmt, ...)
2122{
2123        va_list args;
2124        int i;
2125
2126        va_start(args, fmt);
2127        i = vsscanf(buf, fmt, args);
2128        va_end(args);
2129
2130        return i;
2131}
2132EXPORT_SYMBOL(sscanf);
2133
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