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 <[email protected]> 14 * - changed to provide snprintf and vsnprintf functions 15 * So Feb 1 16:51:32 CET 2004 Juergen Quade <[email protected]> 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 37 static 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 */ 55 unsigned 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 } 79 EXPORT_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 */ 87 unsigned long simple_strtoul(const char *cp, char **endp, unsigned int base) 88 { 89 return simple_strtoull(cp, endp, base); 90 } 91 EXPORT_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 */ 99 long 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 } 106 EXPORT_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 */ 114 long 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 } 121 EXPORT_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 */ 145 int 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 } 168 EXPORT_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 */ 182 int 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 } 195 EXPORT_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 */ 219 int 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 } 241 EXPORT_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 */ 255 int 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 } 268 EXPORT_SYMBOL(strict_strtoll); 269 270 static noinline_for_stack 271 int skip_atoi(const char **s) 272 { 273 int i = 0; 274 275 while (isdigit(**s)) 276 i = i*10 + *((*s)++) - '0'; 277 278 return i; 279 } 280 281 /* Decimal conversion is by far the most typical, and is used 282 * for /proc and /sys data. This directly impacts e.g. top performance 283 * with many processes running. We optimize it for speed 284 * using code from 285 * http://www.cs.uiowa.edu/~jones/bcd/decimal.html 286 * (with permission from the author, Douglas W. Jones). */ 287 288 /* Formats correctly any integer in [0,99999]. 289 * Outputs from one to five digits depending on input. 290 * On i386 gcc 4.1.2 -O2: ~250 bytes of code. */ 291 static noinline_for_stack 292 char *put_dec_trunc(char *buf, unsigned q) 293 { 294 unsigned d3, d2, d1, d0; 295 d1 = (q>>4) & 0xf; 296 d2 = (q>>8) & 0xf; 297 d3 = (q>>12); 298 299 d0 = 6*(d3 + d2 + d1) + (q & 0xf); 300 q = (d0 * 0xcd) >> 11; 301 d0 = d0 - 10*q; 302 *buf++ = d0 + '0'; /* least significant digit */ 303 d1 = q + 9*d3 + 5*d2 + d1; 304 if (d1 != 0) { 305 q = (d1 * 0xcd) >> 11; 306 d1 = d1 - 10*q; 307 *buf++ = d1 + '0'; /* next digit */ 308 309 d2 = q + 2*d2; 310 if ((d2 != 0) || (d3 != 0)) { 311 q = (d2 * 0xd) >> 7; 312 d2 = d2 - 10*q; 313 *buf++ = d2 + '0'; /* next digit */ 314 315 d3 = q + 4*d3; 316 if (d3 != 0) { 317 q = (d3 * 0xcd) >> 11; 318 d3 = d3 - 10*q; 319 *buf++ = d3 + '0'; /* next digit */ 320 if (q != 0) 321 *buf++ = q + '0'; /* most sign. digit */ 322 } 323 } 324 } 325 326 return buf; 327 } 328 /* Same with if's removed. Always emits five digits */ 329 static noinline_for_stack 330 char *put_dec_full(char *buf, unsigned q) 331 { 332 /* BTW, if q is in [0,9999], 8-bit ints will be enough, */ 333 /* but anyway, gcc produces better code with full-sized ints */ 334 unsigned d3, d2, d1, d0; 335 d1 = (q>>4) & 0xf; 336 d2 = (q>>8) & 0xf; 337 d3 = (q>>12); 338 339 /* 340 * Possible ways to approx. divide by 10 341 * gcc -O2 replaces multiply with shifts and adds 342 * (x * 0xcd) >> 11: 11001101 - shorter code than * 0x67 (on i386) 343 * (x * 0x67) >> 10: 1100111 344 * (x * 0x34) >> 9: 110100 - same 345 * (x * 0x1a) >> 8: 11010 - same 346 * (x * 0x0d) >> 7: 1101 - same, shortest code (on i386) 347 */ 348 d0 = 6*(d3 + d2 + d1) + (q & 0xf); 349 q = (d0 * 0xcd) >> 11; 350 d0 = d0 - 10*q; 351 *buf++ = d0 + '0'; 352 d1 = q + 9*d3 + 5*d2 + d1; 353 q = (d1 * 0xcd) >> 11; 354 d1 = d1 - 10*q; 355 *buf++ = d1 + '0'; 356 357 d2 = q + 2*d2; 358 q = (d2 * 0xd) >> 7; 359 d2 = d2 - 10*q; 360 *buf++ = d2 + '0'; 361 362 d3 = q + 4*d3; 363 q = (d3 * 0xcd) >> 11; /* - shorter code */ 364 /* q = (d3 * 0x67) >> 10; - would also work */ 365 d3 = d3 - 10*q; 366 *buf++ = d3 + '0'; 367 *buf++ = q + '0'; 368 369 return buf; 370 } 371 /* No inlining helps gcc to use registers better */ 372 static noinline_for_stack 373 char *put_dec(char *buf, unsigned long long num) 374 { 375 while (1) { 376 unsigned rem; 377 if (num < 100000) 378 return put_dec_trunc(buf, num); 379 rem = do_div(num, 100000); 380 buf = put_dec_full(buf, rem); 381 } 382 } 383 384 #define ZEROPAD 1 /* pad with zero */ 385 #define SIGN 2 /* unsigned/signed long */ 386 #define PLUS 4 /* show plus */ 387 #define SPACE 8 /* space if plus */ 388 #define LEFT 16 /* left justified */ 389 #define SMALL 32 /* use lowercase in hex (must be 32 == 0x20) */ 390 #define SPECIAL 64 /* prefix hex with "0x", octal with "0" */ 391 392 enum format_type { 393 FORMAT_TYPE_NONE, /* Just a string part */ 394 FORMAT_TYPE_WIDTH, 395 FORMAT_TYPE_PRECISION, 396 FORMAT_TYPE_CHAR, 397 FORMAT_TYPE_STR, 398 FORMAT_TYPE_PTR, 399 FORMAT_TYPE_PERCENT_CHAR, 400 FORMAT_TYPE_INVALID, 401 FORMAT_TYPE_LONG_LONG, 402 FORMAT_TYPE_ULONG, 403 FORMAT_TYPE_LONG, 404 FORMAT_TYPE_UBYTE, 405 FORMAT_TYPE_BYTE, 406 FORMAT_TYPE_USHORT, 407 FORMAT_TYPE_SHORT, 408 FORMAT_TYPE_UINT, 409 FORMAT_TYPE_INT, 410 FORMAT_TYPE_NRCHARS, 411 FORMAT_TYPE_SIZE_T, 412 FORMAT_TYPE_PTRDIFF 413 }; 414 415 struct printf_spec { 416 u8 type; /* format_type enum */ 417 u8 flags; /* flags to number() */ 418 u8 base; /* number base, 8, 10 or 16 only */ 419 u8 qualifier; /* number qualifier, one of 'hHlLtzZ' */ 420 s16 field_width; /* width of output field */ 421 s16 precision; /* # of digits/chars */ 422 }; 423 424 static noinline_for_stack 425 char *number(char *buf, char *end, unsigned long long num, 426 struct printf_spec spec) 427 { 428 /* we are called with base 8, 10 or 16, only, thus don't need "G..." */ 429 static const char digits[16] = "0123456789ABCDEF"; /* "GHIJKLMNOPQRSTUVWXYZ"; */ 430 431 char tmp[66]; 432 char sign; 433 char locase; 434 int need_pfx = ((spec.flags & SPECIAL) && spec.base != 10); 435 int i; 436 437 /* locase = 0 or 0x20. ORing digits or letters with 'locase' 438 * produces same digits or (maybe lowercased) letters */ 439 locase = (spec.flags & SMALL); 440 if (spec.flags & LEFT) 441 spec.flags &= ~ZEROPAD; 442 sign = 0; 443 if (spec.flags & SIGN) { 444 if ((signed long long)num < 0) { 445 sign = '-'; 446 num = -(signed long long)num; 447 spec.field_width--; 448 } else if (spec.flags & PLUS) { 449 sign = '+'; 450 spec.field_width--; 451 } else if (spec.flags & SPACE) { 452 sign = ' '; 453 spec.field_width--; 454 } 455 } 456 if (need_pfx) { 457 spec.field_width--; 458 if (spec.base == 16) 459 spec.field_width--; 460 } 461 462 /* generate full string in tmp[], in reverse order */ 463 i = 0; 464 if (num == 0) 465 tmp[i++] = '0'; 466 /* Generic code, for any base: 467 else do { 468 tmp[i++] = (digits[do_div(num,base)] | locase); 469 } while (num != 0); 470 */ 471 else if (spec.base != 10) { /* 8 or 16 */ 472 int mask = spec.base - 1; 473 int shift = 3; 474 475 if (spec.base == 16) 476 shift = 4; 477 do { 478 tmp[i++] = (digits[((unsigned char)num) & mask] | locase); 479 num >>= shift; 480 } while (num); 481 } else { /* base 10 */ 482 i = put_dec(tmp, num) - tmp; 483 } 484 485 /* printing 100 using %2d gives "100", not "00" */ 486 if (i > spec.precision) 487 spec.precision = i; 488 /* leading space padding */ 489 spec.field_width -= spec.precision; 490 if (!(spec.flags & (ZEROPAD+LEFT))) { 491 while (--spec.field_width >= 0) { 492 if (buf < end) 493 *buf = ' '; 494 ++buf; 495 } 496 } 497 /* sign */ 498 if (sign) { 499 if (buf < end) 500 *buf = sign; 501 ++buf; 502 } 503 /* "0x" / "0" prefix */ 504 if (need_pfx) { 505 if (buf < end) 506 *buf = '0'; 507 ++buf; 508 if (spec.base == 16) { 509 if (buf < end) 510 *buf = ('X' | locase); 511 ++buf; 512 } 513 } 514 /* zero or space padding */ 515 if (!(spec.flags & LEFT)) { 516 char c = (spec.flags & ZEROPAD) ? '0' : ' '; 517 while (--spec.field_width >= 0) { 518 if (buf < end) 519 *buf = c; 520 ++buf; 521 } 522 } 523 /* hmm even more zero padding? */ 524 while (i <= --spec.precision) { 525 if (buf < end) 526 *buf = '0'; 527 ++buf; 528 } 529 /* actual digits of result */ 530 while (--i >= 0) { 531 if (buf < end) 532 *buf = tmp[i]; 533 ++buf; 534 } 535 /* trailing space padding */ 536 while (--spec.field_width >= 0) { 537 if (buf < end) 538 *buf = ' '; 539 ++buf; 540 } 541 542 return buf; 543 } 544 545 static noinline_for_stack 546 char *string(char *buf, char *end, const char *s, struct printf_spec spec) 547 { 548 int len, i; 549 550 if ((unsigned long)s < PAGE_SIZE) 551 s = "(null)"; 552 553 len = strnlen(s, spec.precision); 554 555 if (!(spec.flags & LEFT)) { 556 while (len < spec.field_width--) { 557 if (buf < end) 558 *buf = ' '; 559 ++buf; 560 } 561 } 562 for (i = 0; i < len; ++i) { 563 if (buf < end) 564 *buf = *s; 565 ++buf; ++s; 566 } 567 while (len < spec.field_width--) { 568 if (buf < end) 569 *buf = ' '; 570 ++buf; 571 } 572 573 return buf; 574 } 575 576 static noinline_for_stack 577 char *symbol_string(char *buf, char *end, void *ptr, 578 struct printf_spec spec, char ext) 579 { 580 unsigned long value = (unsigned long) ptr; 581 #ifdef CONFIG_KALLSYMS 582 char sym[KSYM_SYMBOL_LEN]; 583 if (ext != 'f' && ext != 's') 584 sprint_symbol(sym, value); 585 else 586 kallsyms_lookup(value, NULL, NULL, NULL, sym); 587 588 return string(buf, end, sym, spec); 589 #else 590 spec.field_width = 2 * sizeof(void *); 591 spec.flags |= SPECIAL | SMALL | ZEROPAD; 592 spec.base = 16; 593 594 return number(buf, end, value, spec); 595 #endif 596 } 597 598 static noinline_for_stack 599 char *resource_string(char *buf, char *end, struct resource *res, 600 struct printf_spec spec, const char *fmt) 601 { 602 #ifndef IO_RSRC_PRINTK_SIZE 603 #define IO_RSRC_PRINTK_SIZE 6 604 #endif 605 606 #ifndef MEM_RSRC_PRINTK_SIZE 607 #define MEM_RSRC_PRINTK_SIZE 10 608 #endif 609 static const struct printf_spec io_spec = { 610 .base = 16, 611 .field_width = IO_RSRC_PRINTK_SIZE, 612 .precision = -1, 613 .flags = SPECIAL | SMALL | ZEROPAD, 614 }; 615 static const struct printf_spec mem_spec = { 616 .base = 16, 617 .field_width = MEM_RSRC_PRINTK_SIZE, 618 .precision = -1, 619 .flags = SPECIAL | SMALL | ZEROPAD, 620 }; 621 static const struct printf_spec bus_spec = { 622 .base = 16, 623 .field_width = 2, 624 .precision = -1, 625 .flags = SMALL | ZEROPAD, 626 }; 627 static const struct printf_spec dec_spec = { 628 .base = 10, 629 .precision = -1, 630 .flags = 0, 631 }; 632 static const struct printf_spec str_spec = { 633 .field_width = -1, 634 .precision = 10, 635 .flags = LEFT, 636 }; 637 static const struct printf_spec flag_spec = { 638 .base = 16, 639 .precision = -1, 640 .flags = SPECIAL | SMALL, 641 }; 642 643 /* 32-bit res (sizeof==4): 10 chars in dec, 10 in hex ("0x" + 8) 644 * 64-bit res (sizeof==8): 20 chars in dec, 18 in hex ("0x" + 16) */ 645 #define RSRC_BUF_SIZE ((2 * sizeof(resource_size_t)) + 4) 646 #define FLAG_BUF_SIZE (2 * sizeof(res->flags)) 647 #define DECODED_BUF_SIZE sizeof("[mem - 64bit pref window disabled]") 648 #define RAW_BUF_SIZE sizeof("[mem - flags 0x]") 649 char sym[max(2*RSRC_BUF_SIZE + DECODED_BUF_SIZE, 650 2*RSRC_BUF_SIZE + FLAG_BUF_SIZE + RAW_BUF_SIZE)]; 651 652 char *p = sym, *pend = sym + sizeof(sym); 653 int decode = (fmt[0] == 'R') ? 1 : 0; 654 const struct printf_spec *specp; 655 656 *p++ = '['; 657 if (res->flags & IORESOURCE_IO) { 658 p = string(p, pend, "io ", str_spec); 659 specp = &io_spec; 660 } else if (res->flags & IORESOURCE_MEM) { 661 p = string(p, pend, "mem ", str_spec); 662 specp = &mem_spec; 663 } else if (res->flags & IORESOURCE_IRQ) { 664 p = string(p, pend, "irq ", str_spec); 665 specp = &dec_spec; 666 } else if (res->flags & IORESOURCE_DMA) { 667 p = string(p, pend, "dma ", str_spec); 668 specp = &dec_spec; 669 } else if (res->flags & IORESOURCE_BUS) { 670 p = string(p, pend, "bus ", str_spec); 671 specp = &bus_spec; 672 } else { 673 p = string(p, pend, "??? ", str_spec); 674 specp = &mem_spec; 675 decode = 0; 676 } 677 p = number(p, pend, res->start, *specp); 678 if (res->start != res->end) { 679 *p++ = '-'; 680 p = number(p, pend, res->end, *specp); 681 } 682 if (decode) { 683 if (res->flags & IORESOURCE_MEM_64) 684 p = string(p, pend, " 64bit", str_spec); 685 if (res->flags & IORESOURCE_PREFETCH) 686 p = string(p, pend, " pref", str_spec); 687 if (res->flags & IORESOURCE_WINDOW) 688 p = string(p, pend, " window", str_spec); 689 if (res->flags & IORESOURCE_DISABLED) 690 p = string(p, pend, " disabled", str_spec); 691 } else { 692 p = string(p, pend, " flags ", str_spec); 693 p = number(p, pend, res->flags, flag_spec); 694 } 695 *p++ = ']'; 696 *p = '\0'; 697 698 return string(buf, end, sym, spec); 699 } 700 701 static noinline_for_stack 702 char *mac_address_string(char *buf, char *end, u8 *addr, 703 struct printf_spec spec, const char *fmt) 704 { 705 char mac_addr[sizeof("xx:xx:xx:xx:xx:xx")]; 706 char *p = mac_addr; 707 int i; 708 char separator; 709 710 if (fmt[1] == 'F') { /* FDDI canonical format */ 711 separator = '-'; 712 } else { 713 separator = ':'; 714 } 715 716 for (i = 0; i < 6; i++) { 717 p = pack_hex_byte(p, addr[i]); 718 if (fmt[0] == 'M' && i != 5) 719 *p++ = separator; 720 } 721 *p = '\0'; 722 723 return string(buf, end, mac_addr, spec); 724 } 725 726 static noinline_for_stack 727 char *ip4_string(char *p, const u8 *addr, const char *fmt) 728 { 729 int i; 730 bool leading_zeros = (fmt[0] == 'i'); 731 int index; 732 int step; 733 734 switch (fmt[2]) { 735 case 'h': 736 #ifdef __BIG_ENDIAN 737 index = 0; 738 step = 1; 739 #else 740 index = 3; 741 step = -1; 742 #endif 743 break; 744 case 'l': 745 index = 3; 746 step = -1; 747 break; 748 case 'n': 749 case 'b': 750 default: 751 index = 0; 752 step = 1; 753 break; 754 } 755 for (i = 0; i < 4; i++) { 756 char temp[3]; /* hold each IP quad in reverse order */ 757 int digits = put_dec_trunc(temp, addr[index]) - temp; 758 if (leading_zeros) { 759 if (digits < 3) 760 *p++ = '0'; 761 if (digits < 2) 762 *p++ = '0'; 763 } 764 /* reverse the digits in the quad */ 765 while (digits--) 766 *p++ = temp[digits]; 767 if (i < 3) 768 *p++ = '.'; 769 index += step; 770 } 771 *p = '\0'; 772 773 return p; 774 } 775 776 static noinline_for_stack 777 char *ip6_compressed_string(char *p, const char *addr) 778 { 779 int i, j, range; 780 unsigned char zerolength[8]; 781 int longest = 1; 782 int colonpos = -1; 783 u16 word; 784 u8 hi, lo; 785 bool needcolon = false; 786 bool useIPv4; 787 struct in6_addr in6; 788 789 memcpy(&in6, addr, sizeof(struct in6_addr)); 790 791 useIPv4 = ipv6_addr_v4mapped(&in6) || ipv6_addr_is_isatap(&in6); 792 793 memset(zerolength, 0, sizeof(zerolength)); 794 795 if (useIPv4) 796 range = 6; 797 else 798 range = 8; 799 800 /* find position of longest 0 run */ 801 for (i = 0; i < range; i++) { 802 for (j = i; j < range; j++) { 803 if (in6.s6_addr16[j] != 0) 804 break; 805 zerolength[i]++; 806 } 807 } 808 for (i = 0; i < range; i++) { 809 if (zerolength[i] > longest) { 810 longest = zerolength[i]; 811 colonpos = i; 812 } 813 } 814 815 /* emit address */ 816 for (i = 0; i < range; i++) { 817 if (i == colonpos) { 818 if (needcolon || i == 0) 819 *p++ = ':'; 820 *p++ = ':'; 821 needcolon = false; 822 i += longest - 1; 823 continue; 824 } 825 if (needcolon) { 826 *p++ = ':'; 827 needcolon = false; 828 } 829 /* hex u16 without leading 0s */ 830 word = ntohs(in6.s6_addr16[i]); 831 hi = word >> 8; 832 lo = word & 0xff; 833 if (hi) { 834 if (hi > 0x0f) 835 p = pack_hex_byte(p, hi); 836 else 837 *p++ = hex_asc_lo(hi); 838 p = pack_hex_byte(p, lo); 839 } 840 else if (lo > 0x0f) 841 p = pack_hex_byte(p, lo); 842 else 843 *p++ = hex_asc_lo(lo); 844 needcolon = true; 845 } 846 847 if (useIPv4) { 848 if (needcolon) 849 *p++ = ':'; 850 p = ip4_string(p, &in6.s6_addr[12], "I4"); 851 } 852 *p = '\0'; 853 854 return p; 855 } 856 857 static noinline_for_stack 858 char *ip6_string(char *p, const char *addr, const char *fmt) 859 { 860 int i; 861 862 for (i = 0; i < 8; i++) { 863 p = pack_hex_byte(p, *addr++); 864 p = pack_hex_byte(p, *addr++); 865 if (fmt[0] == 'I' && i != 7) 866 *p++ = ':'; 867 } 868 *p = '\0'; 869 870 return p; 871 } 872 873 static noinline_for_stack 874 char *ip6_addr_string(char *buf, char *end, const u8 *addr, 875 struct printf_spec spec, const char *fmt) 876 { 877 char ip6_addr[sizeof("xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255")]; 878 879 if (fmt[0] == 'I' && fmt[2] == 'c') 880 ip6_compressed_string(ip6_addr, addr); 881 else 882 ip6_string(ip6_addr, addr, fmt); 883 884 return string(buf, end, ip6_addr, spec); 885 } 886 887 static noinline_for_stack 888 char *ip4_addr_string(char *buf, char *end, const u8 *addr, 889 struct printf_spec spec, const char *fmt) 890 { 891 char ip4_addr[sizeof("255.255.255.255")]; 892 893 ip4_string(ip4_addr, addr, fmt); 894 895 return string(buf, end, ip4_addr, spec); 896 } 897 898 static noinline_for_stack 899 char *uuid_string(char *buf, char *end, const u8 *addr, 900 struct printf_spec spec, const char *fmt) 901 { 902 char uuid[sizeof("xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx")]; 903 char *p = uuid; 904 int i; 905 static const u8 be[16] = {0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15}; 906 static const u8 le[16] = {3,2,1,0,5,4,7,6,8,9,10,11,12,13,14,15}; 907 const u8 *index = be; 908 bool uc = false; 909 910 switch (*(++fmt)) { 911 case 'L': 912 uc = true; /* fall-through */ 913 case 'l': 914 index = le; 915 break; 916 case 'B': 917 uc = true; 918 break; 919 } 920 921 for (i = 0; i < 16; i++) { 922 p = pack_hex_byte(p, addr[index[i]]); 923 switch (i) { 924 case 3: 925 case 5: 926 case 7: 927 case 9: 928 *p++ = '-'; 929 break; 930 } 931 } 932 933 *p = 0; 934 935 if (uc) { 936 p = uuid; 937 do { 938 *p = toupper(*p); 939 } while (*(++p)); 940 } 941 942 return string(buf, end, uuid, spec); 943 } 944 945 /* 946 * Show a '%p' thing. A kernel extension is that the '%p' is followed 947 * by an extra set of alphanumeric characters that are extended format 948 * specifiers. 949 * 950 * Right now we handle: 951 * 952 * - 'F' For symbolic function descriptor pointers with offset 953 * - 'f' For simple symbolic function names without offset 954 * - 'S' For symbolic direct pointers with offset 955 * - 's' For symbolic direct pointers without offset 956 * - 'R' For decoded struct resource, e.g., [mem 0x0-0x1f 64bit pref] 957 * - 'r' For raw struct resource, e.g., [mem 0x0-0x1f flags 0x201] 958 * - 'M' For a 6-byte MAC address, it prints the address in the 959 * usual colon-separated hex notation 960 * - 'm' For a 6-byte MAC address, it prints the hex address without colons 961 * - 'MF' For a 6-byte MAC FDDI address, it prints the address 962 * with a dash-separated hex notation 963 * - 'I' [46] for IPv4/IPv6 addresses printed in the usual way 964 * IPv4 uses dot-separated decimal without leading 0's (1.2.3.4) 965 * IPv6 uses colon separated network-order 16 bit hex with leading 0's 966 * - 'i' [46] for 'raw' IPv4/IPv6 addresses 967 * IPv6 omits the colons (01020304...0f) 968 * IPv4 uses dot-separated decimal with leading 0's (010.123.045.006) 969 * - '[Ii]4[hnbl]' IPv4 addresses in host, network, big or little endian order 970 * - 'I6c' for IPv6 addresses printed as specified by 971 * http://tools.ietf.org/html/draft-ietf-6man-text-addr-representation-00 972 * - 'U' For a 16 byte UUID/GUID, it prints the UUID/GUID in the form 973 * "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx" 974 * Options for %pU are: 975 * b big endian lower case hex (default) 976 * B big endian UPPER case hex 977 * l little endian lower case hex 978 * L little endian UPPER case hex 979 * big endian output byte order is: 980 * [0][1][2][3]-[4][5]-[6][7]-[8][9]-[10][11][12][13][14][15] 981 * little endian output byte order is: 982 * [3][2][1][0]-[5][4]-[7][6]-[8][9]-[10][11][12][13][14][15] 983 * - 'V' For a struct va_format which contains a format string * and va_list *, 984 * call vsnprintf(->format, *->va_list). 985 * Implements a "recursive vsnprintf". 986 * Do not use this feature without some mechanism to verify the 987 * correctness of the format string and va_list arguments. 988 * 989 * Note: The difference between 'S' and 'F' is that on ia64 and ppc64 990 * function pointers are really function descriptors, which contain a 991 * pointer to the real address. 992 */ 993 static noinline_for_stack 994 char *pointer(const char *fmt, char *buf, char *end, void *ptr, 995 struct printf_spec spec) 996 { 997 if (!ptr) 998 return string(buf, end, "(null)", spec); 999 1000 switch (*fmt) { 1001 case 'F': 1002 case 'f': 1003 ptr = dereference_function_descriptor(ptr); 1004 /* Fallthrough */ 1005 case 'S': 1006 case 's': 1007 return symbol_string(buf, end, ptr, spec, *fmt); 1008 case 'R': 1009 case 'r': 1010 return resource_string(buf, end, ptr, spec, fmt); 1011 case 'M': /* Colon separated: 00:01:02:03:04:05 */ 1012 case 'm': /* Contiguous: 000102030405 */ 1013 /* [mM]F (FDDI, bit reversed) */ 1014 return mac_address_string(buf, end, ptr, spec, fmt); 1015 case 'I': /* Formatted IP supported 1016 * 4: 1.2.3.4 1017 * 6: 0001:0203:...:0708 1018 * 6c: 1::708 or 1::1.2.3.4 1019 */ 1020 case 'i': /* Contiguous: 1021 * 4: 001.002.003.004 1022 * 6: 000102...0f 1023 */ 1024 switch (fmt[1]) { 1025 case '6': 1026 return ip6_addr_string(buf, end, ptr, spec, fmt); 1027 case '4': 1028 return ip4_addr_string(buf, end, ptr, spec, fmt); 1029 } 1030 break; 1031 case 'U': 1032 return uuid_string(buf, end, ptr, spec, fmt); 1033 case 'V': 1034 return buf + vsnprintf(buf, end - buf, 1035 ((struct va_format *)ptr)->fmt, 1036 *(((struct va_format *)ptr)->va)); 1037 } 1038 spec.flags |= SMALL; 1039 if (spec.field_width == -1) { 1040 spec.field_width = 2*sizeof(void *); 1041 spec.flags |= ZEROPAD; 1042 } 1043 spec.base = 16; 1044 1045 return number(buf, end, (unsigned long) ptr, spec); 1046 } 1047 1048 /* 1049 * Helper function to decode printf style format. 1050 * Each call decode a token from the format and return the 1051 * number of characters read (or likely the delta where it wants 1052 * to go on the next call). 1053 * The decoded token is returned through the parameters 1054 * 1055 * 'h', 'l', or 'L' for integer fields 1056 * 'z' support added 23/7/1999 S.H. 1057 * 'z' changed to 'Z' --davidm 1/25/99 1058 * 't' added for ptrdiff_t 1059 * 1060 * @fmt: the format string 1061 * @type of the token returned 1062 * @flags: various flags such as +, -, # tokens.. 1063 * @field_width: overwritten width 1064 * @base: base of the number (octal, hex, ...) 1065 * @precision: precision of a number 1066 * @qualifier: qualifier of a number (long, size_t, ...) 1067 */ 1068 static noinline_for_stack 1069 int format_decode(const char *fmt, struct printf_spec *spec) 1070 { 1071 const char *start = fmt; 1072 1073 /* we finished early by reading the field width */ 1074 if (spec->type == FORMAT_TYPE_WIDTH) { 1075 if (spec->field_width < 0) { 1076 spec->field_width = -spec->field_width; 1077 spec->flags |= LEFT; 1078 } 1079 spec->type = FORMAT_TYPE_NONE; 1080 goto precision; 1081 } 1082 1083 /* we finished early by reading the precision */ 1084 if (spec->type == FORMAT_TYPE_PRECISION) { 1085 if (spec->precision < 0) 1086 spec->precision = 0; 1087 1088 spec->type = FORMAT_TYPE_NONE; 1089 goto qualifier; 1090 } 1091 1092 /* By default */ 1093 spec->type = FORMAT_TYPE_NONE; 1094 1095 for (; *fmt ; ++fmt) { 1096 if (*fmt == '%') 1097 break; 1098 } 1099 1100 /* Return the current non-format string */ 1101 if (fmt != start || !*fmt) 1102 return fmt - start; 1103 1104 /* Process flags */ 1105 spec->flags = 0; 1106 1107 while (1) { /* this also skips first '%' */ 1108 bool found = true; 1109 1110 ++fmt; 1111 1112 switch (*fmt) { 1113 case '-': spec->flags |= LEFT; break; 1114 case '+': spec->flags |= PLUS; break; 1115 case ' ': spec->flags |= SPACE; break; 1116 case '#': spec->flags |= SPECIAL; break; 1117 case '0': spec->flags |= ZEROPAD; break; 1118 default: found = false; 1119 } 1120 1121 if (!found) 1122 break; 1123 } 1124 1125 /* get field width */ 1126 spec->field_width = -1; 1127 1128 if (isdigit(*fmt)) 1129 spec->field_width = skip_atoi(&fmt); 1130 else if (*fmt == '*') { 1131 /* it's the next argument */ 1132 spec->type = FORMAT_TYPE_WIDTH; 1133 return ++fmt - start; 1134 } 1135 1136 precision: 1137 /* get the precision */ 1138 spec->precision = -1; 1139 if (*fmt == '.') { 1140 ++fmt; 1141 if (isdigit(*fmt)) { 1142 spec->precision = skip_atoi(&fmt); 1143 if (spec->precision < 0) 1144 spec->precision = 0; 1145 } else if (*fmt == '*') { 1146 /* it's the next argument */ 1147 spec->type = FORMAT_TYPE_PRECISION; 1148 return ++fmt - start; 1149 } 1150 } 1151 1152 qualifier: 1153 /* get the conversion qualifier */ 1154 spec->qualifier = -1; 1155 if (*fmt == 'h' || TOLOWER(*fmt) == 'l' || 1156 TOLOWER(*fmt) == 'z' || *fmt == 't') { 1157 spec->qualifier = *fmt++; 1158 if (unlikely(spec->qualifier == *fmt)) { 1159 if (spec->qualifier == 'l') { 1160 spec->qualifier = 'L'; 1161 ++fmt; 1162 } else if (spec->qualifier == 'h') { 1163 spec->qualifier = 'H'; 1164 ++fmt; 1165 } 1166 } 1167 } 1168 1169 /* default base */ 1170 spec->base = 10; 1171 switch (*fmt) { 1172 case 'c': 1173 spec->type = FORMAT_TYPE_CHAR; 1174 return ++fmt - start; 1175 1176 case 's': 1177 spec->type = FORMAT_TYPE_STR; 1178 return ++fmt - start; 1179 1180 case 'p': 1181 spec->type = FORMAT_TYPE_PTR; 1182 return fmt - start; 1183 /* skip alnum */ 1184 1185 case 'n': 1186 spec->type = FORMAT_TYPE_NRCHARS; 1187 return ++fmt - start; 1188 1189 case '%': 1190 spec->type = FORMAT_TYPE_PERCENT_CHAR; 1191 return ++fmt - start; 1192 1193 /* integer number formats - set up the flags and "break" */ 1194 case 'o': 1195 spec->base = 8; 1196 break; 1197 1198 case 'x': 1199 spec->flags |= SMALL; 1200 1201 case 'X': 1202 spec->base = 16; 1203 break; 1204 1205 case 'd': 1206 case 'i': 1207 spec->flags |= SIGN; 1208 case 'u': 1209 break; 1210 1211 default: 1212 spec->type = FORMAT_TYPE_INVALID; 1213 return fmt - start; 1214 } 1215 1216 if (spec->qualifier == 'L') 1217 spec->type = FORMAT_TYPE_LONG_LONG; 1218 else if (spec->qualifier == 'l') { 1219 if (spec->flags & SIGN) 1220 spec->type = FORMAT_TYPE_LONG; 1221 else 1222 spec->type = FORMAT_TYPE_ULONG; 1223 } else if (TOLOWER(spec->qualifier) == 'z') { 1224 spec->type = FORMAT_TYPE_SIZE_T; 1225 } else if (spec->qualifier == 't') { 1226 spec->type = FORMAT_TYPE_PTRDIFF; 1227 } else if (spec->qualifier == 'H') { 1228 if (spec->flags & SIGN) 1229 spec->type = FORMAT_TYPE_BYTE; 1230 else 1231 spec->type = FORMAT_TYPE_UBYTE; 1232 } else if (spec->qualifier == 'h') { 1233 if (spec->flags & SIGN) 1234 spec->type = FORMAT_TYPE_SHORT; 1235 else 1236 spec->type = FORMAT_TYPE_USHORT; 1237 } else { 1238 if (spec->flags & SIGN) 1239 spec->type = FORMAT_TYPE_INT; 1240 else 1241 spec->type = FORMAT_TYPE_UINT; 1242 } 1243 1244 return ++fmt - start; 1245 } 1246 1247 /** 1248 * vsnprintf - Format a string and place it in a buffer 1249 * @buf: The buffer to place the result into 1250 * @size: The size of the buffer, including the trailing null space 1251 * @fmt: The format string to use 1252 * @args: Arguments for the format string 1253 * 1254 * This function follows C99 vsnprintf, but has some extensions: 1255 * %pS output the name of a text symbol with offset 1256 * %ps output the name of a text symbol without offset 1257 * %pF output the name of a function pointer with its offset 1258 * %pf output the name of a function pointer without its offset 1259 * %pR output the address range in a struct resource with decoded flags 1260 * %pr output the address range in a struct resource with raw flags 1261 * %pM output a 6-byte MAC address with colons 1262 * %pm output a 6-byte MAC address without colons 1263 * %pI4 print an IPv4 address without leading zeros 1264 * %pi4 print an IPv4 address with leading zeros 1265 * %pI6 print an IPv6 address with colons 1266 * %pi6 print an IPv6 address without colons 1267 * %pI6c print an IPv6 address as specified by 1268 * http://tools.ietf.org/html/draft-ietf-6man-text-addr-representation-00 1269 * %pU[bBlL] print a UUID/GUID in big or little endian using lower or upper 1270 * case. 1271 * %n is ignored 1272 * 1273 * The return value is the number of characters which would 1274 * be generated for the given input, excluding the trailing 1275 * '\0', as per ISO C99. If you want to have the exact 1276 * number of characters written into @buf as return value 1277 * (not including the trailing '\0'), use vscnprintf(). If the 1278 * return is greater than or equal to @size, the resulting 1279 * string is truncated. 1280 * 1281 * Call this function if you are already dealing with a va_list. 1282 * You probably want snprintf() instead. 1283 */ 1284 int vsnprintf(char *buf, size_t size, const char *fmt, va_list args) 1285 { 1286 unsigned long long num; 1287 char *str, *end; 1288 struct printf_spec spec = {0}; 1289 1290 /* Reject out-of-range values early. Large positive sizes are 1291 used for unknown buffer sizes. */ 1292 if (WARN_ON_ONCE((int) size < 0)) 1293 return 0; 1294 1295 str = buf; 1296 end = buf + size; 1297 1298 /* Make sure end is always >= buf */ 1299 if (end < buf) { 1300 end = ((void *)-1); 1301 size = end - buf; 1302 } 1303 1304 while (*fmt) { 1305 const char *old_fmt = fmt; 1306 int read = format_decode(fmt, &spec); 1307 1308 fmt += read; 1309 1310 switch (spec.type) { 1311 case FORMAT_TYPE_NONE: { 1312 int copy = read; 1313 if (str < end) { 1314 if (copy > end - str) 1315 copy = end - str; 1316 memcpy(str, old_fmt, copy); 1317 } 1318 str += read; 1319 break; 1320 } 1321 1322 case FORMAT_TYPE_WIDTH: 1323 spec.field_width = va_arg(args, int); 1324 break; 1325 1326 case FORMAT_TYPE_PRECISION: 1327 spec.precision = va_arg(args, int); 1328 break; 1329 1330 case FORMAT_TYPE_CHAR: { 1331 char c; 1332 1333 if (!(spec.flags & LEFT)) { 1334 while (--spec.field_width > 0) { 1335 if (str < end) 1336 *str = ' '; 1337 ++str; 1338 1339 } 1340 } 1341 c = (unsigned char) va_arg(args, int); 1342 if (str < end) 1343 *str = c; 1344 ++str; 1345 while (--spec.field_width > 0) { 1346 if (str < end) 1347 *str = ' '; 1348 ++str; 1349 } 1350 break; 1351 } 1352 1353 case FORMAT_TYPE_STR: 1354 str = string(str, end, va_arg(args, char *), spec); 1355 break; 1356 1357 case FORMAT_TYPE_PTR: 1358 str = pointer(fmt+1, str, end, va_arg(args, void *), 1359 spec); 1360 while (isalnum(*fmt)) 1361 fmt++; 1362 break; 1363 1364 case FORMAT_TYPE_PERCENT_CHAR: 1365 if (str < end) 1366 *str = '%'; 1367 ++str; 1368 break; 1369 1370 case FORMAT_TYPE_INVALID: 1371 if (str < end) 1372 *str = '%'; 1373 ++str; 1374 break; 1375 1376 case FORMAT_TYPE_NRCHARS: { 1377 u8 qualifier = spec.qualifier; 1378 1379 if (qualifier == 'l') { 1380 long *ip = va_arg(args, long *); 1381 *ip = (str - buf); 1382 } else if (TOLOWER(qualifier) == 'z') { 1383 size_t *ip = va_arg(args, size_t *); 1384 *ip = (str - buf); 1385 } else { 1386 int *ip = va_arg(args, int *); 1387 *ip = (str - buf); 1388 } 1389 break; 1390 } 1391 1392 default: 1393 switch (spec.type) { 1394 case FORMAT_TYPE_LONG_LONG: 1395 num = va_arg(args, long long); 1396 break; 1397 case FORMAT_TYPE_ULONG: 1398 num = va_arg(args, unsigned long); 1399 break; 1400 case FORMAT_TYPE_LONG: 1401 num = va_arg(args, long); 1402 break; 1403 case FORMAT_TYPE_SIZE_T: 1404 num = va_arg(args, size_t); 1405 break; 1406 case FORMAT_TYPE_PTRDIFF: 1407 num = va_arg(args, ptrdiff_t); 1408 break; 1409 case FORMAT_TYPE_UBYTE: 1410 num = (unsigned char) va_arg(args, int); 1411 break; 1412 case FORMAT_TYPE_BYTE: 1413 num = (signed char) va_arg(args, int); 1414 break; 1415 case FORMAT_TYPE_USHORT: 1416 num = (unsigned short) va_arg(args, int); 1417 break; 1418 case FORMAT_TYPE_SHORT: 1419 num = (short) va_arg(args, int); 1420 break; 1421 case FORMAT_TYPE_INT: 1422 num = (int) va_arg(args, int); 1423 break; 1424 default: 1425 num = va_arg(args, unsigned int); 1426 } 1427 1428 str = number(str, end, num, spec); 1429 } 1430 } 1431 1432 if (size > 0) { 1433 if (str < end) 1434 *str = '\0'; 1435 else 1436 end[-1] = '\0'; 1437 } 1438 1439 /* the trailing null byte doesn't count towards the total */ 1440 return str-buf; 1441 1442 } 1443 EXPORT_SYMBOL(vsnprintf); 1444 1445 /** 1446 * vscnprintf - 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 * @args: Arguments for the format string 1451 * 1452 * The return value is the number of characters which have been written into 1453 * the @buf not including the trailing '\0'. If @size is <= 0 the function 1454 * returns 0. 1455 * 1456 * Call this function if you are already dealing with a va_list. 1457 * You probably want scnprintf() instead. 1458 * 1459 * See the vsnprintf() documentation for format string extensions over C99. 1460 */ 1461 int vscnprintf(char *buf, size_t size, const char *fmt, va_list args) 1462 { 1463 int i; 1464 1465 i = vsnprintf(buf, size, fmt, args); 1466 1467 return (i >= size) ? (size - 1) : i; 1468 } 1469 EXPORT_SYMBOL(vscnprintf); 1470 1471 /** 1472 * snprintf - Format a string and place it in a buffer 1473 * @buf: The buffer to place the result into 1474 * @size: The size of the buffer, including the trailing null space 1475 * @fmt: The format string to use 1476 * @...: Arguments for the format string 1477 * 1478 * The return value is the number of characters which would be 1479 * generated for the given input, excluding the trailing null, 1480 * as per ISO C99. If the return is greater than or equal to 1481 * @size, the resulting string is truncated. 1482 * 1483 * See the vsnprintf() documentation for format string extensions over C99. 1484 */ 1485 int snprintf(char *buf, size_t size, const char *fmt, ...) 1486 { 1487 va_list args; 1488 int i; 1489 1490 va_start(args, fmt); 1491 i = vsnprintf(buf, size, fmt, args); 1492 va_end(args); 1493 1494 return i; 1495 } 1496 EXPORT_SYMBOL(snprintf); 1497 1498 /** 1499 * scnprintf - Format a string and place it in a buffer 1500 * @buf: The buffer to place the result into 1501 * @size: The size of the buffer, including the trailing null space 1502 * @fmt: The format string to use 1503 * @...: Arguments for the format string 1504 * 1505 * The return value is the number of characters written into @buf not including 1506 * the trailing '\0'. If @size is <= 0 the function returns 0. 1507 */ 1508 1509 int scnprintf(char *buf, size_t size, const char *fmt, ...) 1510 { 1511 va_list args; 1512 int i; 1513 1514 va_start(args, fmt); 1515 i = vsnprintf(buf, size, fmt, args); 1516 va_end(args); 1517 1518 return (i >= size) ? (size - 1) : i; 1519 } 1520 EXPORT_SYMBOL(scnprintf); 1521 1522 /** 1523 * vsprintf - Format a string and place it in a buffer 1524 * @buf: The buffer to place the result into 1525 * @fmt: The format string to use 1526 * @args: Arguments for the format string 1527 * 1528 * The function returns the number of characters written 1529 * into @buf. Use vsnprintf() or vscnprintf() in order to avoid 1530 * buffer overflows. 1531 * 1532 * Call this function if you are already dealing with a va_list. 1533 * You probably want sprintf() instead. 1534 * 1535 * See the vsnprintf() documentation for format string extensions over C99. 1536 */ 1537 int vsprintf(char *buf, const char *fmt, va_list args) 1538 { 1539 return vsnprintf(buf, INT_MAX, fmt, args); 1540 } 1541 EXPORT_SYMBOL(vsprintf); 1542 1543 /** 1544 * sprintf - Format a string and place it in a buffer 1545 * @buf: The buffer to place the result into 1546 * @fmt: The format string to use 1547 * @...: Arguments for the format string 1548 * 1549 * The function returns the number of characters written 1550 * into @buf. Use snprintf() or scnprintf() in order to avoid 1551 * buffer overflows. 1552 * 1553 * See the vsnprintf() documentation for format string extensions over C99. 1554 */ 1555 int sprintf(char *buf, const char *fmt, ...) 1556 { 1557 va_list args; 1558 int i; 1559 1560 va_start(args, fmt); 1561 i = vsnprintf(buf, INT_MAX, fmt, args); 1562 va_end(args); 1563 1564 return i; 1565 } 1566 EXPORT_SYMBOL(sprintf); 1567 1568 #ifdef CONFIG_BINARY_PRINTF 1569 /* 1570 * bprintf service: 1571 * vbin_printf() - VA arguments to binary data 1572 * bstr_printf() - Binary data to text string 1573 */ 1574 1575 /** 1576 * vbin_printf - Parse a format string and place args' binary value in a buffer 1577 * @bin_buf: The buffer to place args' binary value 1578 * @size: The size of the buffer(by words(32bits), not characters) 1579 * @fmt: The format string to use 1580 * @args: Arguments for the format string 1581 * 1582 * The format follows C99 vsnprintf, except %n is ignored, and its argument 1583 * is skiped. 1584 * 1585 * The return value is the number of words(32bits) which would be generated for 1586 * the given input. 1587 * 1588 * NOTE: 1589 * If the return value is greater than @size, the resulting bin_buf is NOT 1590 * valid for bstr_printf(). 1591 */ 1592 int vbin_printf(u32 *bin_buf, size_t size, const char *fmt, va_list args) 1593 { 1594 struct printf_spec spec = {0}; 1595 char *str, *end; 1596 1597 str = (char *)bin_buf; 1598 end = (char *)(bin_buf + size); 1599 1600 #define save_arg(type) \ 1601 do { \ 1602 if (sizeof(type) == 8) { \ 1603 unsigned long long value; \ 1604 str = PTR_ALIGN(str, sizeof(u32)); \ 1605 value = va_arg(args, unsigned long long); \ 1606 if (str + sizeof(type) <= end) { \ 1607 *(u32 *)str = *(u32 *)&value; \ 1608 *(u32 *)(str + 4) = *((u32 *)&value + 1); \ 1609 } \ 1610 } else { \ 1611 unsigned long value; \ 1612 str = PTR_ALIGN(str, sizeof(type)); \ 1613 value = va_arg(args, int); \ 1614 if (str + sizeof(type) <= end) \ 1615 *(typeof(type) *)str = (type)value; \ 1616 } \ 1617 str += sizeof(type); \ 1618 } while (0) 1619 1620 while (*fmt) { 1621 int read = format_decode(fmt, &spec); 1622 1623 fmt += read; 1624 1625 switch (spec.type) { 1626 case FORMAT_TYPE_NONE: 1627 case FORMAT_TYPE_INVALID: 1628 case FORMAT_TYPE_PERCENT_CHAR: 1629 break; 1630 1631 case FORMAT_TYPE_WIDTH: 1632 case FORMAT_TYPE_PRECISION: 1633 save_arg(int); 1634 break; 1635 1636 case FORMAT_TYPE_CHAR: 1637 save_arg(char); 1638 break; 1639 1640 case FORMAT_TYPE_STR: { 1641 const char *save_str = va_arg(args, char *); 1642 size_t len; 1643 1644 if ((unsigned long)save_str > (unsigned long)-PAGE_SIZE 1645 || (unsigned long)save_str < PAGE_SIZE) 1646 save_str = "(null)"; 1647 len = strlen(save_str) + 1; 1648 if (str + len < end) 1649 memcpy(str, save_str, len); 1650 str += len; 1651 break; 1652 } 1653 1654 case FORMAT_TYPE_PTR: 1655 save_arg(void *); 1656 /* skip all alphanumeric pointer suffixes */ 1657 while (isalnum(*fmt)) 1658 fmt++; 1659 break; 1660 1661 case FORMAT_TYPE_NRCHARS: { 1662 /* skip %n 's argument */ 1663 u8 qualifier = spec.qualifier; 1664 void *skip_arg; 1665 if (qualifier == 'l') 1666 skip_arg = va_arg(args, long *); 1667 else if (TOLOWER(qualifier) == 'z') 1668 skip_arg = va_arg(args, size_t *); 1669 else 1670 skip_arg = va_arg(args, int *); 1671 break; 1672 } 1673 1674 default: 1675 switch (spec.type) { 1676 1677 case FORMAT_TYPE_LONG_LONG: 1678 save_arg(long long); 1679 break; 1680 case FORMAT_TYPE_ULONG: 1681 case FORMAT_TYPE_LONG: 1682 save_arg(unsigned long); 1683 break; 1684 case FORMAT_TYPE_SIZE_T: 1685 save_arg(size_t); 1686 break; 1687 case FORMAT_TYPE_PTRDIFF: 1688 save_arg(ptrdiff_t); 1689 break; 1690 case FORMAT_TYPE_UBYTE: 1691 case FORMAT_TYPE_BYTE: 1692 save_arg(char); 1693 break; 1694 case FORMAT_TYPE_USHORT: 1695 case FORMAT_TYPE_SHORT: 1696 save_arg(short); 1697 break; 1698 default: 1699 save_arg(int); 1700 } 1701 } 1702 } 1703 1704 return (u32 *)(PTR_ALIGN(str, sizeof(u32))) - bin_buf; 1705 #undef save_arg 1706 } 1707 EXPORT_SYMBOL_GPL(vbin_printf); 1708 1709 /** 1710 * bstr_printf - Format a string from binary arguments and place it in a buffer 1711 * @buf: The buffer to place the result into 1712 * @size: The size of the buffer, including the trailing null space 1713 * @fmt: The format string to use 1714 * @bin_buf: Binary arguments for the format string 1715 * 1716 * This function like C99 vsnprintf, but the difference is that vsnprintf gets 1717 * arguments from stack, and bstr_printf gets arguments from @bin_buf which is 1718 * a binary buffer that generated by vbin_printf. 1719 * 1720 * The format follows C99 vsnprintf, but has some extensions: 1721 * see vsnprintf comment for details. 1722 * 1723 * The return value is the number of characters which would 1724 * be generated for the given input, excluding the trailing 1725 * '\0', as per ISO C99. If you want to have the exact 1726 * number of characters written into @buf as return value 1727 * (not including the trailing '\0'), use vscnprintf(). If the 1728 * return is greater than or equal to @size, the resulting 1729 * string is truncated. 1730 */ 1731 int bstr_printf(char *buf, size_t size, const char *fmt, const u32 *bin_buf) 1732 { 1733 struct printf_spec spec = {0}; 1734 char *str, *end; 1735 const char *args = (const char *)bin_buf; 1736 1737 if (WARN_ON_ONCE((int) size < 0)) 1738 return 0; 1739 1740 str = buf; 1741 end = buf + size; 1742 1743 #define get_arg(type) \ 1744 ({ \ 1745 typeof(type) value; \ 1746 if (sizeof(type) == 8) { \ 1747 args = PTR_ALIGN(args, sizeof(u32)); \ 1748 *(u32 *)&value = *(u32 *)args; \ 1749 *((u32 *)&value + 1) = *(u32 *)(args + 4); \ 1750 } else { \ 1751 args = PTR_ALIGN(args, sizeof(type)); \ 1752 value = *(typeof(type) *)args; \ 1753 } \ 1754 args += sizeof(type); \ 1755 value; \ 1756 }) 1757 1758 /* Make sure end is always >= buf */ 1759 if (end < buf) { 1760 end = ((void *)-1); 1761 size = end - buf; 1762 } 1763 1764 while (*fmt) { 1765 const char *old_fmt = fmt; 1766 int read = format_decode(fmt, &spec); 1767 1768 fmt += read; 1769 1770 switch (spec.type) { 1771 case FORMAT_TYPE_NONE: { 1772 int copy = read; 1773 if (str < end) { 1774 if (copy > end - str) 1775 copy = end - str; 1776 memcpy(str, old_fmt, copy); 1777 } 1778 str += read; 1779 break; 1780 } 1781 1782 case FORMAT_TYPE_WIDTH: 1783 spec.field_width = get_arg(int); 1784 break; 1785 1786 case FORMAT_TYPE_PRECISION: 1787 spec.precision = get_arg(int); 1788 break; 1789 1790 case FORMAT_TYPE_CHAR: { 1791 char c; 1792 1793 if (!(spec.flags & LEFT)) { 1794 while (--spec.field_width > 0) { 1795 if (str < end) 1796 *str = ' '; 1797 ++str; 1798 } 1799 } 1800 c = (unsigned char) get_arg(char); 1801 if (str < end) 1802 *str = c; 1803 ++str; 1804 while (--spec.field_width > 0) { 1805 if (str < end) 1806 *str = ' '; 1807 ++str; 1808 } 1809 break; 1810 } 1811 1812 case FORMAT_TYPE_STR: { 1813 const char *str_arg = args; 1814 args += strlen(str_arg) + 1; 1815 str = string(str, end, (char *)str_arg, spec); 1816 break; 1817 } 1818 1819 case FORMAT_TYPE_PTR: 1820 str = pointer(fmt+1, str, end, get_arg(void *), spec); 1821 while (isalnum(*fmt)) 1822 fmt++; 1823 break; 1824 1825 case FORMAT_TYPE_PERCENT_CHAR: 1826 case FORMAT_TYPE_INVALID: 1827 if (str < end) 1828 *str = '%'; 1829 ++str; 1830 break; 1831 1832 case FORMAT_TYPE_NRCHARS: 1833 /* skip */ 1834 break; 1835 1836 default: { 1837 unsigned long long num; 1838 1839 switch (spec.type) { 1840 1841 case FORMAT_TYPE_LONG_LONG: 1842 num = get_arg(long long); 1843 break; 1844 case FORMAT_TYPE_ULONG: 1845 case FORMAT_TYPE_LONG: 1846 num = get_arg(unsigned long); 1847 break; 1848 case FORMAT_TYPE_SIZE_T: 1849 num = get_arg(size_t); 1850 break; 1851 case FORMAT_TYPE_PTRDIFF: 1852 num = get_arg(ptrdiff_t); 1853 break; 1854 case FORMAT_TYPE_UBYTE: 1855 num = get_arg(unsigned char); 1856 break; 1857 case FORMAT_TYPE_BYTE: 1858 num = get_arg(signed char); 1859 break; 1860 case FORMAT_TYPE_USHORT: 1861 num = get_arg(unsigned short); 1862 break; 1863 case FORMAT_TYPE_SHORT: 1864 num = get_arg(short); 1865 break; 1866 case FORMAT_TYPE_UINT: 1867 num = get_arg(unsigned int); 1868 break; 1869 default: 1870 num = get_arg(int); 1871 } 1872 1873 str = number(str, end, num, spec); 1874 } /* default: */ 1875 } /* switch(spec.type) */ 1876 } /* while(*fmt) */ 1877 1878 if (size > 0) { 1879 if (str < end) 1880 *str = '\0'; 1881 else 1882 end[-1] = '\0'; 1883 } 1884 1885 #undef get_arg 1886 1887 /* the trailing null byte doesn't count towards the total */ 1888 return str - buf; 1889 } 1890 EXPORT_SYMBOL_GPL(bstr_printf); 1891 1892 /** 1893 * bprintf - Parse a format string and place args' binary value in a buffer 1894 * @bin_buf: The buffer to place args' binary value 1895 * @size: The size of the buffer(by words(32bits), not characters) 1896 * @fmt: The format string to use 1897 * @...: Arguments for the format string 1898 * 1899 * The function returns the number of words(u32) written 1900 * into @bin_buf. 1901 */ 1902 int bprintf(u32 *bin_buf, size_t size, const char *fmt, ...) 1903 { 1904 va_list args; 1905 int ret; 1906 1907 va_start(args, fmt); 1908 ret = vbin_printf(bin_buf, size, fmt, args); 1909 va_end(args); 1910 1911 return ret; 1912 } 1913 EXPORT_SYMBOL_GPL(bprintf); 1914 1915 #endif /* CONFIG_BINARY_PRINTF */ 1916 1917 /** 1918 * vsscanf - Unformat a buffer into a list of arguments 1919 * @buf: input buffer 1920 * @fmt: format of buffer 1921 * @args: arguments 1922 */ 1923 int vsscanf(const char *buf, const char *fmt, va_list args) 1924 { 1925 const char *str = buf; 1926 char *next; 1927 char digit; 1928 int num = 0; 1929 u8 qualifier; 1930 u8 base; 1931 s16 field_width; 1932 bool is_sign; 1933 1934 while (*fmt && *str) { 1935 /* skip any white space in format */ 1936 /* white space in format matchs any amount of 1937 * white space, including none, in the input. 1938 */ 1939 if (isspace(*fmt)) { 1940 fmt = skip_spaces(++fmt); 1941 str = skip_spaces(str); 1942 } 1943 1944 /* anything that is not a conversion must match exactly */ 1945 if (*fmt != '%' && *fmt) { 1946 if (*fmt++ != *str++) 1947 break; 1948 continue; 1949 } 1950 1951 if (!*fmt) 1952 break; 1953 ++fmt; 1954 1955 /* skip this conversion. 1956 * advance both strings to next white space 1957 */ 1958 if (*fmt == '*') { 1959 while (!isspace(*fmt) && *fmt != '%' && *fmt) 1960 fmt++; 1961 while (!isspace(*str) && *str) 1962 str++; 1963 continue; 1964 } 1965 1966 /* get field width */ 1967 field_width = -1; 1968 if (isdigit(*fmt)) 1969 field_width = skip_atoi(&fmt); 1970 1971 /* get conversion qualifier */ 1972 qualifier = -1; 1973 if (*fmt == 'h' || TOLOWER(*fmt) == 'l' || 1974 TOLOWER(*fmt) == 'z') { 1975 qualifier = *fmt++; 1976 if (unlikely(qualifier == *fmt)) { 1977 if (qualifier == 'h') { 1978 qualifier = 'H'; 1979 fmt++; 1980 } else if (qualifier == 'l') { 1981 qualifier = 'L'; 1982 fmt++; 1983 } 1984 } 1985 } 1986 1987 if (!*fmt || !*str) 1988 break; 1989 1990 base = 10; 1991 is_sign = 0; 1992 1993 switch (*fmt++) { 1994 case 'c': 1995 { 1996 char *s = (char *)va_arg(args, char*); 1997 if (field_width == -1) 1998 field_width = 1; 1999 do { 2000 *s++ = *str++; 2001 } while (--field_width > 0 && *str); 2002 num++; 2003 } 2004 continue; 2005 case 's': 2006 { 2007 char *s = (char *)va_arg(args, char *); 2008 if (field_width == -1) 2009 field_width = SHRT_MAX; 2010 /* first, skip leading white space in buffer */ 2011 str = skip_spaces(str); 2012 2013 /* now copy until next white space */ 2014 while (*str && !isspace(*str) && field_width--) 2015 *s++ = *str++; 2016 *s = '\0'; 2017 num++; 2018 } 2019 continue; 2020 case 'n': 2021 /* return number of characters read so far */ 2022 { 2023 int *i = (int *)va_arg(args, int*); 2024 *i = str - buf; 2025 } 2026 continue; 2027 case 'o': 2028 base = 8; 2029 break; 2030 case 'x': 2031 case 'X': 2032 base = 16; 2033 break; 2034 case 'i': 2035 base = 0; 2036 case 'd': 2037 is_sign = 1; 2038 case 'u': 2039 break; 2040 case '%': 2041 /* looking for '%' in str */ 2042 if (*str++ != '%') 2043 return num; 2044 continue; 2045 default: 2046 /* invalid format; stop here */ 2047 return num; 2048 } 2049 2050 /* have some sort of integer conversion. 2051 * first, skip white space in buffer. 2052 */ 2053 str = skip_spaces(str); 2054 2055 digit = *str; 2056 if (is_sign && digit == '-') 2057 digit = *(str + 1); 2058 2059 if (!digit 2060 || (base == 16 && !isxdigit(digit)) 2061 || (base == 10 && !isdigit(digit)) 2062 || (base == 8 && (!isdigit(digit) || digit > '7')) 2063 || (base == 0 && !isdigit(digit))) 2064 break; 2065 2066 switch (qualifier) { 2067 case 'H': /* that's 'hh' in format */ 2068 if (is_sign) { 2069 signed char *s = (signed char *)va_arg(args, signed char *); 2070 *s = (signed char)simple_strtol(str, &next, base); 2071 } else { 2072 unsigned char *s = (unsigned char *)va_arg(args, unsigned char *); 2073 *s = (unsigned char)simple_strtoul(str, &next, base); 2074 } 2075 break; 2076 case 'h': 2077 if (is_sign) { 2078 short *s = (short *)va_arg(args, short *); 2079 *s = (short)simple_strtol(str, &next, base); 2080 } else { 2081 unsigned short *s = (unsigned short *)va_arg(args, unsigned short *); 2082 *s = (unsigned short)simple_strtoul(str, &next, base); 2083 } 2084 break; 2085 case 'l': 2086 if (is_sign) { 2087 long *l = (long *)va_arg(args, long *); 2088 *l = simple_strtol(str, &next, base); 2089 } else { 2090 unsigned long *l = (unsigned long *)va_arg(args, unsigned long *); 2091 *l = simple_strtoul(str, &next, base); 2092 } 2093 break; 2094 case 'L': 2095 if (is_sign) { 2096 long long *l = (long long *)va_arg(args, long long *); 2097 *l = simple_strtoll(str, &next, base); 2098 } else { 2099 unsigned long long *l = (unsigned long long *)va_arg(args, unsigned long long *); 2100 *l = simple_strtoull(str, &next, base); 2101 } 2102 break; 2103 case 'Z': 2104 case 'z': 2105 { 2106 size_t *s = (size_t *)va_arg(args, size_t *); 2107 *s = (size_t)simple_strtoul(str, &next, base); 2108 } 2109 break; 2110 default: 2111 if (is_sign) { 2112 int *i = (int *)va_arg(args, int *); 2113 *i = (int)simple_strtol(str, &next, base); 2114 } else { 2115 unsigned int *i = (unsigned int *)va_arg(args, unsigned int*); 2116 *i = (unsigned int)simple_strtoul(str, &next, base); 2117 } 2118 break; 2119 } 2120 num++; 2121 2122 if (!next) 2123 break; 2124 str = next; 2125 } 2126 2127 /* 2128 * Now we've come all the way through so either the input string or the 2129 * format ended. In the former case, there can be a %n at the current 2130 * position in the format that needs to be filled. 2131 */ 2132 if (*fmt == '%' && *(fmt + 1) == 'n') { 2133 int *p = (int *)va_arg(args, int *); 2134 *p = str - buf; 2135 } 2136 2137 return num; 2138 } 2139 EXPORT_SYMBOL(vsscanf); 2140 2141 /** 2142 * sscanf - Unformat a buffer into a list of arguments 2143 * @buf: input buffer 2144 * @fmt: formatting of buffer 2145 * @...: resulting arguments 2146 */ 2147 int sscanf(const char *buf, const char *fmt, ...) 2148 { 2149 va_list args; 2150 int i; 2151 2152 va_start(args, fmt); 2153 i = vsscanf(buf, fmt, args); 2154 va_end(args); 2155 2156 return i; 2157 } 2158 EXPORT_SYMBOL(sscanf); 2159