lib/vsprintf.c

   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 #include <stdarg.h>
  13 #include <linux/types.h>
  14 #include <linux/string.h>
  15 #include <linux/ctype.h>
  16
  17 #include <common.h>
  18 #if !defined (CONFIG_PANIC_HANG)
  19 #include <command.h>
  20 #endif
  21
  22 #include <div64.h>
  23 # define NUM_TYPE long long
  24 #define noinline __attribute__((noinline))
  25
  26 const char hex_asc[] = "0123456789abcdef";
  27 #define hex_asc_lo(x)   hex_asc[((x) & 0x0f)]
  28 #define hex_asc_hi(x)   hex_asc[((x) & 0xf0) >> 4]
  29
  30 static inline char *pack_hex_byte(char *buf, u8 byte)
  31 {
  32         *buf++ = hex_asc_hi(byte);
  33         *buf++ = hex_asc_lo(byte);
  34         return buf;
  35 }
  36
  37 unsigned long simple_strtoul(const char *cp,char **endp,unsigned int base)
  38 {
  39         unsigned long result = 0,value;
  40
  41         if (*cp == '0') {
  42                 cp++;
  43                 if ((*cp == 'x') && isxdigit(cp[1])) {
  44                         base = 16;
  45                         cp++;
  46                 }
  47                 if (!base) {
  48                         base = 8;
  49                 }
  50         }
  51         if (!base) {
  52                 base = 10;
  53         }
  54         while (isxdigit(*cp) && (value = isdigit(*cp) ? *cp-'0' : (islower(*cp)
  55             ? toupper(*cp) : *cp)-'A'+10) < base) {
  56                 result = result*base + value;
  57                 cp++;
  58         }
  59         if (endp)
  60                 *endp = (char *)cp;
  61         return result;
  62 }
  63
  64 long simple_strtol(const char *cp,char **endp,unsigned int base)
  65 {
  66         if(*cp=='-')
  67                 return -simple_strtoul(cp+1,endp,base);
  68         return simple_strtoul(cp,endp,base);
  69 }
  70
  71 int ustrtoul(const char *cp, char **endp, unsigned int base)
  72 {
  73         unsigned long result = simple_strtoul(cp, endp, base);
  74         switch (**endp) {
  75         case 'G' :
  76                 result *= 1024;
  77                 /* fall through */
  78         case 'M':
  79                 result *= 1024;
  80                 /* fall through */
  81         case 'K':
  82         case 'k':
  83                 result *= 1024;
  84                 if ((*endp)[1] == 'i') {
  85                         if ((*endp)[2] == 'B')
  86                                 (*endp) += 3;
  87                         else
  88                                 (*endp) += 2;
  89                 }
  90         }
  91         return result;
  92 }
  93
  94 unsigned long long simple_strtoull (const char *cp, char **endp, unsigned int base)
  95 {
  96         unsigned long long result = 0, value;
  97
  98         if (*cp == '0') {
  99                 cp++;
 100                 if ((*cp == 'x') && isxdigit (cp[1])) {
 101                         base = 16;
 102                         cp++;
 103                 }
 104                 if (!base) {
 105                         base = 8;
 106                 }
 107         }
 108         if (!base) {
 109                 base = 10;
 110         }
 111         while (isxdigit (*cp) && (value = isdigit (*cp)
 112                                 ? *cp - '0'
 113                                 : (islower (*cp) ? toupper (*cp) : *cp) - 'A' + 10) < base) {
 114                 result = result * base + value;
 115                 cp++;
 116         }
 117         if (endp)
 118                 *endp = (char *) cp;
 119         return result;
 120 }
 121
 122 /* we use this so that we can do without the ctype library */
 123 #define is_digit(c)     ((c) >= '0' && (c) <= '9')
 124
 125 static int skip_atoi(const char **s)
 126 {
 127         int i=0;
 128
 129         while (is_digit(**s))
 130                 i = i*10 + *((*s)++) - '0';
 131         return i;
 132 }
 133
 134 /* Decimal conversion is by far the most typical, and is used
 135  * for /proc and /sys data. This directly impacts e.g. top performance
 136  * with many processes running. We optimize it for speed
 137  * using code from
 138  * http://www.cs.uiowa.edu/~jones/bcd/decimal.html
 139  * (with permission from the author, Douglas W. Jones). */
 140
 141 /* Formats correctly any integer in [0,99999].
 142  * Outputs from one to five digits depending on input.
 143  * On i386 gcc 4.1.2 -O2: ~250 bytes of code. */
 144 static char* put_dec_trunc(char *buf, unsigned q)
 145 {
 146         unsigned d3, d2, d1, d0;
 147         d1 = (q>>4) & 0xf;
 148         d2 = (q>>8) & 0xf;
 149         d3 = (q>>12);
 150
 151         d0 = 6*(d3 + d2 + d1) + (q & 0xf);
 152         q = (d0 * 0xcd) >> 11;
 153         d0 = d0 - 10*q;
 154         *buf++ = d0 + '0'; /* least significant digit */
 155         d1 = q + 9*d3 + 5*d2 + d1;
 156         if (d1 != 0) {
 157                 q = (d1 * 0xcd) >> 11;
 158                 d1 = d1 - 10*q;
 159                 *buf++ = d1 + '0'; /* next digit */
 160
 161                 d2 = q + 2*d2;
 162                 if ((d2 != 0) || (d3 != 0)) {
 163                         q = (d2 * 0xd) >> 7;
 164                         d2 = d2 - 10*q;
 165                         *buf++ = d2 + '0'; /* next digit */
 166
 167                         d3 = q + 4*d3;
 168                         if (d3 != 0) {
 169                                 q = (d3 * 0xcd) >> 11;
 170                                 d3 = d3 - 10*q;
 171                                 *buf++ = d3 + '0';  /* next digit */
 172                                 if (q != 0)
 173                                         *buf++ = q + '0';  /* most sign. digit */
 174                         }
 175                 }
 176         }
 177         return buf;
 178 }
 179 /* Same with if's removed. Always emits five digits */
 180 static char* put_dec_full(char *buf, unsigned q)
 181 {
 182         /* BTW, if q is in [0,9999], 8-bit ints will be enough, */
 183         /* but anyway, gcc produces better code with full-sized ints */
 184         unsigned d3, d2, d1, d0;
 185         d1 = (q>>4) & 0xf;
 186         d2 = (q>>8) & 0xf;
 187         d3 = (q>>12);
 188
 189         /*
 190          * Possible ways to approx. divide by 10
 191          * gcc -O2 replaces multiply with shifts and adds
 192          * (x * 0xcd) >> 11: 11001101 - shorter code than * 0x67 (on i386)
 193          * (x * 0x67) >> 10:  1100111
 194          * (x * 0x34) >> 9:    110100 - same
 195          * (x * 0x1a) >> 8:     11010 - same
 196          * (x * 0x0d) >> 7:      1101 - same, shortest code (on i386)
 197          */
 198
 199         d0 = 6*(d3 + d2 + d1) + (q & 0xf);
 200         q = (d0 * 0xcd) >> 11;
 201         d0 = d0 - 10*q;
 202         *buf++ = d0 + '0';
 203         d1 = q + 9*d3 + 5*d2 + d1;
 204                 q = (d1 * 0xcd) >> 11;
 205                 d1 = d1 - 10*q;
 206                 *buf++ = d1 + '0';
 207
 208                 d2 = q + 2*d2;
 209                         q = (d2 * 0xd) >> 7;
 210                         d2 = d2 - 10*q;
 211                         *buf++ = d2 + '0';
 212
 213                         d3 = q + 4*d3;
 214                                 q = (d3 * 0xcd) >> 11; /* - shorter code */
 215                                 /* q = (d3 * 0x67) >> 10; - would also work */
 216                                 d3 = d3 - 10*q;
 217                                 *buf++ = d3 + '0';
 218                                         *buf++ = q + '0';
 219         return buf;
 220 }
 221 /* No inlining helps gcc to use registers better */
 222 static noinline char* put_dec(char *buf, unsigned NUM_TYPE num)
 223 {
 224         while (1) {
 225                 unsigned rem;
 226                 if (num < 100000)
 227                         return put_dec_trunc(buf, num);
 228                 rem = do_div(num, 100000);
 229                 buf = put_dec_full(buf, rem);
 230         }
 231 }
 232
 233 #define ZEROPAD 1               /* pad with zero */
 234 #define SIGN    2               /* unsigned/signed long */
 235 #define PLUS    4               /* show plus */
 236 #define SPACE   8               /* space if plus */
 237 #define LEFT    16              /* left justified */
 238 #define SMALL   32              /* Must be 32 == 0x20 */
 239 #define SPECIAL 64              /* 0x */
 240
 241 static char *number(char *buf, unsigned NUM_TYPE num, int base, int size, int precision, int type)
 242 {
 243         /* we are called with base 8, 10 or 16, only, thus don't need "G..."  */
 244         static const char digits[16] = "0123456789ABCDEF"; /* "GHIJKLMNOPQRSTUVWXYZ"; */
 245
 246         char tmp[66];
 247         char sign;
 248         char locase;
 249         int need_pfx = ((type & SPECIAL) && base != 10);
 250         int i;
 251
 252         /* locase = 0 or 0x20. ORing digits or letters with 'locase'
 253          * produces same digits or (maybe lowercased) letters */
 254         locase = (type & SMALL);
 255         if (type & LEFT)
 256                 type &= ~ZEROPAD;
 257         sign = 0;
 258         if (type & SIGN) {
 259                 if ((signed NUM_TYPE) num < 0) {
 260                         sign = '-';
 261                         num = - (signed NUM_TYPE) num;
 262                         size--;
 263                 } else if (type & PLUS) {
 264                         sign = '+';
 265                         size--;
 266                 } else if (type & SPACE) {
 267                         sign = ' ';
 268                         size--;
 269                 }
 270         }
 271         if (need_pfx) {
 272                 size--;
 273                 if (base == 16)
 274                         size--;
 275         }
 276
 277         /* generate full string in tmp[], in reverse order */
 278         i = 0;
 279         if (num == 0)
 280                 tmp[i++] = '0';
 281         /* Generic code, for any base:
 282         else do {
 283                 tmp[i++] = (digits[do_div(num,base)] | locase);
 284         } while (num != 0);
 285         */
 286         else if (base != 10) { /* 8 or 16 */
 287                 int mask = base - 1;
 288                 int shift = 3;
 289                 if (base == 16) shift = 4;
 290                 do {
 291                         tmp[i++] = (digits[((unsigned char)num) & mask] | locase);
 292                         num >>= shift;
 293                 } while (num);
 294         } else { /* base 10 */
 295                 i = put_dec(tmp, num) - tmp;
 296         }
 297
 298         /* printing 100 using %2d gives "100", not "00" */
 299         if (i > precision)
 300                 precision = i;
 301         /* leading space padding */
 302         size -= precision;
 303         if (!(type & (ZEROPAD+LEFT)))
 304                 while(--size >= 0)
 305                         *buf++ = ' ';
 306         /* sign */
 307         if (sign)
 308                 *buf++ = sign;
 309         /* "0x" / "0" prefix */
 310         if (need_pfx) {
 311                 *buf++ = '0';
 312                 if (base == 16)
 313                         *buf++ = ('X' | locase);
 314         }
 315         /* zero or space padding */
 316         if (!(type & LEFT)) {
 317                 char c = (type & ZEROPAD) ? '0' : ' ';
 318                 while (--size >= 0)
 319                         *buf++ = c;
 320         }
 321         /* hmm even more zero padding? */
 322         while (i <= --precision)
 323                 *buf++ = '0';
 324         /* actual digits of result */
 325         while (--i >= 0)
 326                 *buf++ = tmp[i];
 327         /* trailing space padding */
 328         while (--size >= 0)
 329                 *buf++ = ' ';
 330         return buf;
 331 }
 332
 333 static char *string(char *buf, char *s, int field_width, int precision, int flags)
 334 {
 335         int len, i;
 336
 337         if (s == 0)
 338                 s = "<NULL>";
 339
 340         len = strnlen(s, precision);
 341
 342         if (!(flags & LEFT))
 343                 while (len < field_width--)
 344                         *buf++ = ' ';
 345         for (i = 0; i < len; ++i)
 346                 *buf++ = *s++;
 347         while (len < field_width--)
 348                 *buf++ = ' ';
 349         return buf;
 350 }
 351
 352 #ifdef CONFIG_CMD_NET
 353 static char *mac_address_string(char *buf, u8 *addr, int field_width,
 354                                 int precision, int flags)
 355 {
 356         char mac_addr[6 * 3]; /* (6 * 2 hex digits), 5 colons and trailing zero */
 357         char *p = mac_addr;
 358         int i;
 359
 360         for (i = 0; i < 6; i++) {
 361                 p = pack_hex_byte(p, addr[i]);
 362                 if (!(flags & SPECIAL) && i != 5)
 363                         *p++ = ':';
 364         }
 365         *p = '\0';
 366
 367         return string(buf, mac_addr, field_width, precision, flags & ~SPECIAL);
 368 }
 369
 370 static char *ip6_addr_string(char *buf, u8 *addr, int field_width,
 371                          int precision, int flags)
 372 {
 373         char ip6_addr[8 * 5]; /* (8 * 4 hex digits), 7 colons and trailing zero */
 374         char *p = ip6_addr;
 375         int i;
 376
 377         for (i = 0; i < 8; i++) {
 378                 p = pack_hex_byte(p, addr[2 * i]);
 379                 p = pack_hex_byte(p, addr[2 * i + 1]);
 380                 if (!(flags & SPECIAL) && i != 7)
 381                         *p++ = ':';
 382         }
 383         *p = '\0';
 384
 385         return string(buf, ip6_addr, field_width, precision, flags & ~SPECIAL);
 386 }
 387
 388 static char *ip4_addr_string(char *buf, u8 *addr, int field_width,
 389                          int precision, int flags)
 390 {
 391         char ip4_addr[4 * 4]; /* (4 * 3 decimal digits), 3 dots and trailing zero */
 392         char temp[3];   /* hold each IP quad in reverse order */
 393         char *p = ip4_addr;
 394         int i, digits;
 395
 396         for (i = 0; i < 4; i++) {
 397                 digits = put_dec_trunc(temp, addr[i]) - temp;
 398                 /* reverse the digits in the quad */
 399                 while (digits--)
 400                         *p++ = temp[digits];
 401                 if (i != 3)
 402                         *p++ = '.';
 403         }
 404         *p = '\0';
 405
 406         return string(buf, ip4_addr, field_width, precision, flags & ~SPECIAL);
 407 }
 408 #endif
 409
 410 /*
 411  * Show a '%p' thing.  A kernel extension is that the '%p' is followed
 412  * by an extra set of alphanumeric characters that are extended format
 413  * specifiers.
 414  *
 415  * Right now we handle:
 416  *
 417  * - 'M' For a 6-byte MAC address, it prints the address in the
 418  *       usual colon-separated hex notation
 419  * - 'I' [46] for IPv4/IPv6 addresses printed in the usual way (dot-separated
 420  *       decimal for v4 and colon separated network-order 16 bit hex for v6)
 421  * - 'i' [46] for 'raw' IPv4/IPv6 addresses, IPv6 omits the colons, IPv4 is
 422  *       currently the same
 423  *
 424  * Note: The difference between 'S' and 'F' is that on ia64 and ppc64
 425  * function pointers are really function descriptors, which contain a
 426  * pointer to the real address.
 427  */
 428 static char *pointer(const char *fmt, char *buf, void *ptr, int field_width, int precision, int flags)
 429 {
 430         if (!ptr)
 431                 return string(buf, "(null)", field_width, precision, flags);
 432
 433 #ifdef CONFIG_CMD_NET
 434         switch (*fmt) {
 435         case 'm':
 436                 flags |= SPECIAL;
 437                 /* Fallthrough */
 438         case 'M':
 439                 return mac_address_string(buf, ptr, field_width, precision, flags);
 440         case 'i':
 441                 flags |= SPECIAL;
 442                 /* Fallthrough */
 443         case 'I':
 444                 if (fmt[1] == '6')
 445                         return ip6_addr_string(buf, ptr, field_width, precision, flags);
 446                 if (fmt[1] == '4')
 447                         return ip4_addr_string(buf, ptr, field_width, precision, flags);
 448                 flags &= ~SPECIAL;
 449                 break;
 450         }
 451 #endif
 452         flags |= SMALL;
 453         if (field_width == -1) {
 454                 field_width = 2*sizeof(void *);
 455                 flags |= ZEROPAD;
 456         }
 457         return number(buf, (unsigned long) ptr, 16, field_width, precision, flags);
 458 }
 459
 460 /**
 461  * vsprintf - Format a string and place it in a buffer
 462  * @buf: The buffer to place the result into
 463  * @fmt: The format string to use
 464  * @args: Arguments for the format string
 465  *
 466  * This function follows C99 vsprintf, but has some extensions:
 467  * %pS output the name of a text symbol
 468  * %pF output the name of a function pointer
 469  * %pR output the address range in a struct resource
 470  *
 471  * The function returns the number of characters written
 472  * into @buf.
 473  *
 474  * Call this function if you are already dealing with a va_list.
 475  * You probably want sprintf() instead.
 476  */
 477 int vsprintf(char *buf, const char *fmt, va_list args)
 478 {
 479         unsigned NUM_TYPE num;
 480         int base;
 481         char *str;
 482
 483         int flags;              /* flags to number() */
 484
 485         int field_width;        /* width of output field */
 486         int precision;          /* min. # of digits for integers; max
 487                                    number of chars for from string */
 488         int qualifier;          /* 'h', 'l', or 'L' for integer fields */
 489                                 /* 'z' support added 23/7/1999 S.H.    */
 490                                 /* 'z' changed to 'Z' --davidm 1/25/99 */
 491                                 /* 't' added for ptrdiff_t */
 492
 493         str = buf;
 494
 495         for (; *fmt ; ++fmt) {
 496                 if (*fmt != '%') {
 497                         *str++ = *fmt;
 498                         continue;
 499                 }
 500
 501                 /* process flags */
 502                 flags = 0;
 503                 repeat:
 504                         ++fmt;          /* this also skips first '%' */
 505                         switch (*fmt) {
 506                                 case '-': flags |= LEFT; goto repeat;
 507                                 case '+': flags |= PLUS; goto repeat;
 508                                 case ' ': flags |= SPACE; goto repeat;
 509                                 case '#': flags |= SPECIAL; goto repeat;
 510                                 case '0': flags |= ZEROPAD; goto repeat;
 511                         }
 512
 513                 /* get field width */
 514                 field_width = -1;
 515                 if (is_digit(*fmt))
 516                         field_width = skip_atoi(&fmt);
 517                 else if (*fmt == '*') {
 518                         ++fmt;
 519                         /* it's the next argument */
 520                         field_width = va_arg(args, int);
 521                         if (field_width < 0) {
 522                                 field_width = -field_width;
 523                                 flags |= LEFT;
 524                         }
 525                 }
 526
 527                 /* get the precision */
 528                 precision = -1;
 529                 if (*fmt == '.') {
 530                         ++fmt;
 531                         if (is_digit(*fmt))
 532                                 precision = skip_atoi(&fmt);
 533                         else if (*fmt == '*') {
 534                                 ++fmt;
 535                                 /* it's the next argument */
 536                                 precision = va_arg(args, int);
 537                         }
 538                         if (precision < 0)
 539                                 precision = 0;
 540                 }
 541
 542                 /* get the conversion qualifier */
 543                 qualifier = -1;
 544                 if (*fmt == 'h' || *fmt == 'l' || *fmt == 'L' ||
 545                     *fmt == 'Z' || *fmt == 'z' || *fmt == 't') {
 546                         qualifier = *fmt;
 547                         ++fmt;
 548                         if (qualifier == 'l' && *fmt == 'l') {
 549                                 qualifier = 'L';
 550                                 ++fmt;
 551                         }
 552                 }
 553
 554                 /* default base */
 555                 base = 10;
 556
 557                 switch (*fmt) {
 558                 case 'c':
 559                         if (!(flags & LEFT))
 560                                 while (--field_width > 0)
 561                                         *str++ = ' ';
 562                         *str++ = (unsigned char) va_arg(args, int);
 563                         while (--field_width > 0)
 564                                 *str++ = ' ';
 565                         continue;
 566
 567                 case 's':
 568                         str = string(str, va_arg(args, char *), field_width, precision, flags);
 569                         continue;
 570
 571                 case 'p':
 572                         str = pointer(fmt+1, str,
 573                                         va_arg(args, void *),
 574                                         field_width, precision, flags);
 575                         /* Skip all alphanumeric pointer suffixes */
 576                         while (isalnum(fmt[1]))
 577                                 fmt++;
 578                         continue;
 579
 580                 case 'n':
 581                         if (qualifier == 'l') {
 582                                 long * ip = va_arg(args, long *);
 583                                 *ip = (str - buf);
 584                         } else {
 585                                 int * ip = va_arg(args, int *);
 586                                 *ip = (str - buf);
 587                         }
 588                         continue;
 589
 590                 case '%':
 591                         *str++ = '%';
 592                         continue;
 593
 594                 /* integer number formats - set up the flags and "break" */
 595                 case 'o':
 596                         base = 8;
 597                         break;
 598
 599                 case 'x':
 600                         flags |= SMALL;
 601                 case 'X':
 602                         base = 16;
 603                         break;
 604
 605                 case 'd':
 606                 case 'i':
 607                         flags |= SIGN;
 608                 case 'u':
 609                         break;
 610
 611                 default:
 612                         *str++ = '%';
 613                         if (*fmt)
 614                                 *str++ = *fmt;
 615                         else
 616                                 --fmt;
 617                         continue;
 618                 }
 619                 if (qualifier == 'L')  /* "quad" for 64 bit variables */
 620                         num = va_arg(args, unsigned long long);
 621                 else if (qualifier == 'l') {
 622                         num = va_arg(args, unsigned long);
 623                         if (flags & SIGN)
 624                                 num = (signed long) num;
 625                 } else if (qualifier == 'Z' || qualifier == 'z') {
 626                         num = va_arg(args, size_t);
 627                 } else if (qualifier == 't') {
 628                         num = va_arg(args, ptrdiff_t);
 629                 } else if (qualifier == 'h') {
 630                         num = (unsigned short) va_arg(args, int);
 631                         if (flags & SIGN)
 632                                 num = (signed short) num;
 633                 } else {
 634                         num = va_arg(args, unsigned int);
 635                         if (flags & SIGN)
 636                                 num = (signed int) num;
 637                 }
 638                 str = number(str, num, base, field_width, precision, flags);
 639         }
 640         *str = '\0';
 641         return str-buf;
 642 }
 643
 644 /**
 645  * sprintf - Format a string and place it in a buffer
 646  * @buf: The buffer to place the result into
 647  * @fmt: The format string to use
 648  * @...: Arguments for the format string
 649  *
 650  * The function returns the number of characters written
 651  * into @buf.
 652  *
 653  * See the vsprintf() documentation for format string extensions over C99.
 654  */
 655 int sprintf(char * buf, const char *fmt, ...)
 656 {
 657         va_list args;
 658         int i;
 659
 660         va_start(args, fmt);
 661         i=vsprintf(buf,fmt,args);
 662         va_end(args);
 663         return i;
 664 }
 665
 666 void panic(const char *fmt, ...)
 667 {
 668         va_list args;
 669         va_start(args, fmt);
 670         vprintf(fmt, args);
 671         putc('\n');
 672         va_end(args);
 673 #if defined (CONFIG_PANIC_HANG)
 674         hang();
 675 #else
 676         udelay (100000);        /* allow messages to go out */
 677         do_reset (NULL, 0, 0, NULL);
 678 #endif
 679 }