1 /* 2 * linux/lib/vsprintf.c 3 * 4 * Copyright (C) 1991, 1992 Linus Torvalds 5 */ 6 7 /* vsprintf.c -- Lars Wirzenius & Linus Torvalds. */ 8 /* 9 * Wirzenius wrote this portably, Torvalds fucked it up :-) 10 */ 11 12 /* 13 * Fri Jul 13 2001 Crutcher Dunnavant <crutcher+kernel@datastacks.com> 14 * - changed to provide snprintf and vsnprintf functions 15 * So Feb 1 16:51:32 CET 2004 Juergen Quade <quade@hsnr.de> 16 * - scnprintf and vscnprintf 17 */ 18 19 #include <stdarg.h> 20 #include <linux/module.h> /* for KSYM_SYMBOL_LEN */ 21 #include <linux/types.h> 22 #include <linux/string.h> 23 #include <linux/ctype.h> 24 #include <linux/kernel.h> 25 #include <linux/kallsyms.h> 26 #include <linux/uaccess.h> 27 #include <linux/ioport.h> 28 #include <net/addrconf.h> 29 30 #include <asm/page.h> /* for PAGE_SIZE */ 31 #include <asm/div64.h> 32 #include <asm/sections.h> /* for dereference_function_descriptor() */ 33 34 #include "kstrtox.h" 35 36 /** 37 * simple_strtoull - convert a string to an unsigned long long 38 * @cp: The start of the string 39 * @endp: A pointer to the end of the parsed string will be placed here 40 * @base: The number base to use 41 */ 42 unsigned long long simple_strtoull(const char *cp, char **endp, unsigned int base) 43 { 44 unsigned long long result; 45 unsigned int rv; 46 47 cp = _parse_integer_fixup_radix(cp, &base); 48 rv = _parse_integer(cp, base, &result); 49 /* FIXME */ 50 cp += (rv & ~KSTRTOX_OVERFLOW); 51 52 if (endp) 53 *endp = (char *)cp; 54 55 return result; 56 } 57 EXPORT_SYMBOL(simple_strtoull); 58 59 /** 60 * simple_strtoul - convert a string to an unsigned long 61 * @cp: The start of the string 62 * @endp: A pointer to the end of the parsed string will be placed here 63 * @base: The number base to use 64 */ 65 unsigned long simple_strtoul(const char *cp, char **endp, unsigned int base) 66 { 67 return simple_strtoull(cp, endp, base); 68 } 69 EXPORT_SYMBOL(simple_strtoul); 70 71 /** 72 * simple_strtol - convert a string to a signed long 73 * @cp: The start of the string 74 * @endp: A pointer to the end of the parsed string will be placed here 75 * @base: The number base to use 76 */ 77 long simple_strtol(const char *cp, char **endp, unsigned int base) 78 { 79 if (*cp == '-') 80 return -simple_strtoul(cp + 1, endp, base); 81 82 return simple_strtoul(cp, endp, base); 83 } 84 EXPORT_SYMBOL(simple_strtol); 85 86 /** 87 * simple_strtoll - convert a string to a signed long long 88 * @cp: The start of the string 89 * @endp: A pointer to the end of the parsed string will be placed here 90 * @base: The number base to use 91 */ 92 long long simple_strtoll(const char *cp, char **endp, unsigned int base) 93 { 94 if (*cp == '-') 95 return -simple_strtoull(cp + 1, endp, base); 96 97 return simple_strtoull(cp, endp, base); 98 } 99 EXPORT_SYMBOL(simple_strtoll); 100 101 static noinline_for_stack 102 int skip_atoi(const char **s) 103 { 104 int i = 0; 105 106 while (isdigit(**s)) 107 i = i*10 + *((*s)++) - '0'; 108 109 return i; 110 } 111 112 /* Decimal conversion is by far the most typical, and is used 113 * for /proc and /sys data. This directly impacts e.g. top performance 114 * with many processes running. We optimize it for speed 115 * using ideas described at <http://www.cs.uiowa.edu/~jones/bcd/divide.html> 116 * (with permission from the author, Douglas W. Jones). 117 */ 118 119 #if BITS_PER_LONG != 32 || BITS_PER_LONG_LONG != 64 120 /* Formats correctly any integer in [0, 999999999] */ 121 static noinline_for_stack 122 char *put_dec_full9(char *buf, unsigned q) 123 { 124 unsigned r; 125 126 /* 127 * Possible ways to approx. divide by 10 128 * (x * 0x1999999a) >> 32 x < 1073741829 (multiply must be 64-bit) 129 * (x * 0xcccd) >> 19 x < 81920 (x < 262149 when 64-bit mul) 130 * (x * 0x6667) >> 18 x < 43699 131 * (x * 0x3334) >> 17 x < 16389 132 * (x * 0x199a) >> 16 x < 16389 133 * (x * 0x0ccd) >> 15 x < 16389 134 * (x * 0x0667) >> 14 x < 2739 135 * (x * 0x0334) >> 13 x < 1029 136 * (x * 0x019a) >> 12 x < 1029 137 * (x * 0x00cd) >> 11 x < 1029 shorter code than * 0x67 (on i386) 138 * (x * 0x0067) >> 10 x < 179 139 * (x * 0x0034) >> 9 x < 69 same 140 * (x * 0x001a) >> 8 x < 69 same 141 * (x * 0x000d) >> 7 x < 69 same, shortest code (on i386) 142 * (x * 0x0007) >> 6 x < 19 143 * See <http://www.cs.uiowa.edu/~jones/bcd/divide.html> 144 */ 145 r = (q * (uint64_t)0x1999999a) >> 32; 146 *buf++ = (q - 10 * r) + '0'; /* 1 */ 147 q = (r * (uint64_t)0x1999999a) >> 32; 148 *buf++ = (r - 10 * q) + '0'; /* 2 */ 149 r = (q * (uint64_t)0x1999999a) >> 32; 150 *buf++ = (q - 10 * r) + '0'; /* 3 */ 151 q = (r * (uint64_t)0x1999999a) >> 32; 152 *buf++ = (r - 10 * q) + '0'; /* 4 */ 153 r = (q * (uint64_t)0x1999999a) >> 32; 154 *buf++ = (q - 10 * r) + '0'; /* 5 */ 155 /* Now value is under 10000, can avoid 64-bit multiply */ 156 q = (r * 0x199a) >> 16; 157 *buf++ = (r - 10 * q) + '0'; /* 6 */ 158 r = (q * 0xcd) >> 11; 159 *buf++ = (q - 10 * r) + '0'; /* 7 */ 160 q = (r * 0xcd) >> 11; 161 *buf++ = (r - 10 * q) + '0'; /* 8 */ 162 *buf++ = q + '0'; /* 9 */ 163 return buf; 164 } 165 #endif 166 167 /* Similar to above but do not pad with zeros. 168 * Code can be easily arranged to print 9 digits too, but our callers 169 * always call put_dec_full9() instead when the number has 9 decimal digits. 170 */ 171 static noinline_for_stack 172 char *put_dec_trunc8(char *buf, unsigned r) 173 { 174 unsigned q; 175 176 /* Copy of previous function's body with added early returns */ 177 q = (r * (uint64_t)0x1999999a) >> 32; 178 *buf++ = (r - 10 * q) + '0'; /* 2 */ 179 if (q == 0) 180 return buf; 181 r = (q * (uint64_t)0x1999999a) >> 32; 182 *buf++ = (q - 10 * r) + '0'; /* 3 */ 183 if (r == 0) 184 return buf; 185 q = (r * (uint64_t)0x1999999a) >> 32; 186 *buf++ = (r - 10 * q) + '0'; /* 4 */ 187 if (q == 0) 188 return buf; 189 r = (q * (uint64_t)0x1999999a) >> 32; 190 *buf++ = (q - 10 * r) + '0'; /* 5 */ 191 if (r == 0) 192 return buf; 193 q = (r * 0x199a) >> 16; 194 *buf++ = (r - 10 * q) + '0'; /* 6 */ 195 if (q == 0) 196 return buf; 197 r = (q * 0xcd) >> 11; 198 *buf++ = (q - 10 * r) + '0'; /* 7 */ 199 if (r == 0) 200 return buf; 201 q = (r * 0xcd) >> 11; 202 *buf++ = (r - 10 * q) + '0'; /* 8 */ 203 if (q == 0) 204 return buf; 205 *buf++ = q + '0'; /* 9 */ 206 return buf; 207 } 208 209 /* There are two algorithms to print larger numbers. 210 * One is generic: divide by 1000000000 and repeatedly print 211 * groups of (up to) 9 digits. It's conceptually simple, 212 * but requires a (unsigned long long) / 1000000000 division. 213 * 214 * Second algorithm splits 64-bit unsigned long long into 16-bit chunks, 215 * manipulates them cleverly and generates groups of 4 decimal digits. 216 * It so happens that it does NOT require long long division. 217 * 218 * If long is > 32 bits, division of 64-bit values is relatively easy, 219 * and we will use the first algorithm. 220 * If long long is > 64 bits (strange architecture with VERY large long long), 221 * second algorithm can't be used, and we again use the first one. 222 * 223 * Else (if long is 32 bits and long long is 64 bits) we use second one. 224 */ 225 226 #if BITS_PER_LONG != 32 || BITS_PER_LONG_LONG != 64 227 228 /* First algorithm: generic */ 229 230 static 231 char *put_dec(char *buf, unsigned long long n) 232 { 233 if (n >= 100*1000*1000) { 234 while (n >= 1000*1000*1000) 235 buf = put_dec_full9(buf, do_div(n, 1000*1000*1000)); 236 if (n >= 100*1000*1000) 237 return put_dec_full9(buf, n); 238 } 239 return put_dec_trunc8(buf, n); 240 } 241 242 #else 243 244 /* Second algorithm: valid only for 64-bit long longs */ 245 246 static noinline_for_stack 247 char *put_dec_full4(char *buf, unsigned q) 248 { 249 unsigned r; 250 r = (q * 0xcccd) >> 19; 251 *buf++ = (q - 10 * r) + '0'; 252 q = (r * 0x199a) >> 16; 253 *buf++ = (r - 10 * q) + '0'; 254 r = (q * 0xcd) >> 11; 255 *buf++ = (q - 10 * r) + '0'; 256 *buf++ = r + '0'; 257 return buf; 258 } 259 260 /* Based on code by Douglas W. Jones found at 261 * <http://www.cs.uiowa.edu/~jones/bcd/decimal.html#sixtyfour> 262 * (with permission from the author). 263 * Performs no 64-bit division and hence should be fast on 32-bit machines. 264 */ 265 static 266 char *put_dec(char *buf, unsigned long long n) 267 { 268 uint32_t d3, d2, d1, q, h; 269 270 if (n < 100*1000*1000) 271 return put_dec_trunc8(buf, n); 272 273 d1 = ((uint32_t)n >> 16); /* implicit "& 0xffff" */ 274 h = (n >> 32); 275 d2 = (h ) & 0xffff; 276 d3 = (h >> 16); /* implicit "& 0xffff" */ 277 278 q = 656 * d3 + 7296 * d2 + 5536 * d1 + ((uint32_t)n & 0xffff); 279 280 buf = put_dec_full4(buf, q % 10000); 281 q = q / 10000; 282 283 d1 = q + 7671 * d3 + 9496 * d2 + 6 * d1; 284 buf = put_dec_full4(buf, d1 % 10000); 285 q = d1 / 10000; 286 287 d2 = q + 4749 * d3 + 42 * d2; 288 buf = put_dec_full4(buf, d2 % 10000); 289 q = d2 / 10000; 290 291 d3 = q + 281 * d3; 292 if (!d3) 293 goto done; 294 buf = put_dec_full4(buf, d3 % 10000); 295 q = d3 / 10000; 296 if (!q) 297 goto done; 298 buf = put_dec_full4(buf, q); 299 done: 300 while (buf[-1] == '0') 301 --buf; 302 303 return buf; 304 } 305 306 #endif 307 308 /* 309 * Convert passed number to decimal string. 310 * Returns the length of string. On buffer overflow, returns 0. 311 * 312 * If speed is not important, use snprintf(). It's easy to read the code. 313 */ 314 int num_to_str(char *buf, int size, unsigned long long num) 315 { 316 char tmp[sizeof(num) * 3]; 317 int idx, len; 318 319 /* put_dec() may work incorrectly for num = 0 (generate "", not "0") */ 320 if (num <= 9) { 321 tmp[0] = '0' + num; 322 len = 1; 323 } else { 324 len = put_dec(tmp, num) - tmp; 325 } 326 327 if (len > size) 328 return 0; 329 for (idx = 0; idx < len; ++idx) 330 buf[idx] = tmp[len - idx - 1]; 331 return len; 332 } 333 334 #define ZEROPAD 1 /* pad with zero */ 335 #define SIGN 2 /* unsigned/signed long */ 336 #define PLUS 4 /* show plus */ 337 #define SPACE 8 /* space if plus */ 338 #define LEFT 16 /* left justified */ 339 #define SMALL 32 /* use lowercase in hex (must be 32 == 0x20) */ 340 #define SPECIAL 64 /* prefix hex with "0x", octal with "0" */ 341 342 enum format_type { 343 FORMAT_TYPE_NONE, /* Just a string part */ 344 FORMAT_TYPE_WIDTH, 345 FORMAT_TYPE_PRECISION, 346 FORMAT_TYPE_CHAR, 347 FORMAT_TYPE_STR, 348 FORMAT_TYPE_PTR, 349 FORMAT_TYPE_PERCENT_CHAR, 350 FORMAT_TYPE_INVALID, 351 FORMAT_TYPE_LONG_LONG, 352 FORMAT_TYPE_ULONG, 353 FORMAT_TYPE_LONG, 354 FORMAT_TYPE_UBYTE, 355 FORMAT_TYPE_BYTE, 356 FORMAT_TYPE_USHORT, 357 FORMAT_TYPE_SHORT, 358 FORMAT_TYPE_UINT, 359 FORMAT_TYPE_INT, 360 FORMAT_TYPE_NRCHARS, 361 FORMAT_TYPE_SIZE_T, 362 FORMAT_TYPE_PTRDIFF 363 }; 364 365 struct printf_spec { 366 u8 type; /* format_type enum */ 367 u8 flags; /* flags to number() */ 368 u8 base; /* number base, 8, 10 or 16 only */ 369 u8 qualifier; /* number qualifier, one of 'hHlLtzZ' */ 370 s16 field_width; /* width of output field */ 371 s16 precision; /* # of digits/chars */ 372 }; 373 374 static noinline_for_stack 375 char *number(char *buf, char *end, unsigned long long num, 376 struct printf_spec spec) 377 { 378 /* we are called with base 8, 10 or 16, only, thus don't need "G..." */ 379 static const char digits[16] = "0123456789ABCDEF"; /* "GHIJKLMNOPQRSTUVWXYZ"; */ 380 381 char tmp[66]; 382 char sign; 383 char locase; 384 int need_pfx = ((spec.flags & SPECIAL) && spec.base != 10); 385 int i; 386 bool is_zero = num == 0LL; 387 388 /* locase = 0 or 0x20. ORing digits or letters with 'locase' 389 * produces same digits or (maybe lowercased) letters */ 390 locase = (spec.flags & SMALL); 391 if (spec.flags & LEFT) 392 spec.flags &= ~ZEROPAD; 393 sign = 0; 394 if (spec.flags & SIGN) { 395 if ((signed long long)num < 0) { 396 sign = '-'; 397 num = -(signed long long)num; 398 spec.field_width--; 399 } else if (spec.flags & PLUS) { 400 sign = '+'; 401 spec.field_width--; 402 } else if (spec.flags & SPACE) { 403 sign = ' '; 404 spec.field_width--; 405 } 406 } 407 if (need_pfx) { 408 if (spec.base == 16) 409 spec.field_width -= 2; 410 else if (!is_zero) 411 spec.field_width--; 412 } 413 414 /* generate full string in tmp[], in reverse order */ 415 i = 0; 416 if (num < spec.base) 417 tmp[i++] = digits[num] | locase; 418 /* Generic code, for any base: 419 else do { 420 tmp[i++] = (digits[do_div(num,base)] | locase); 421 } while (num != 0); 422 */ 423 else if (spec.base != 10) { /* 8 or 16 */ 424 int mask = spec.base - 1; 425 int shift = 3; 426 427 if (spec.base == 16) 428 shift = 4; 429 do { 430 tmp[i++] = (digits[((unsigned char)num) & mask] | locase); 431 num >>= shift; 432 } while (num); 433 } else { /* base 10 */ 434 i = put_dec(tmp, num) - tmp; 435 } 436 437 /* printing 100 using %2d gives "100", not "00" */ 438 if (i > spec.precision) 439 spec.precision = i; 440 /* leading space padding */ 441 spec.field_width -= spec.precision; 442 if (!(spec.flags & (ZEROPAD+LEFT))) { 443 while (--spec.field_width >= 0) { 444 if (buf < end) 445 *buf = ' '; 446 ++buf; 447 } 448 } 449 /* sign */ 450 if (sign) { 451 if (buf < end) 452 *buf = sign; 453 ++buf; 454 } 455 /* "0x" / "0" prefix */ 456 if (need_pfx) { 457 if (spec.base == 16 || !is_zero) { 458 if (buf < end) 459 *buf = '0'; 460 ++buf; 461 } 462 if (spec.base == 16) { 463 if (buf < end) 464 *buf = ('X' | locase); 465 ++buf; 466 } 467 } 468 /* zero or space padding */ 469 if (!(spec.flags & LEFT)) { 470 char c = (spec.flags & ZEROPAD) ? '0' : ' '; 471 while (--spec.field_width >= 0) { 472 if (buf < end) 473 *buf = c; 474 ++buf; 475 } 476 } 477 /* hmm even more zero padding? */ 478 while (i <= --spec.precision) { 479 if (buf < end) 480 *buf = '0'; 481 ++buf; 482 } 483 /* actual digits of result */ 484 while (--i >= 0) { 485 if (buf < end) 486 *buf = tmp[i]; 487 ++buf; 488 } 489 /* trailing space padding */ 490 while (--spec.field_width >= 0) { 491 if (buf < end) 492 *buf = ' '; 493 ++buf; 494 } 495 496 return buf; 497 } 498 499 static noinline_for_stack 500 char *string(char *buf, char *end, const char *s, struct printf_spec spec) 501 { 502 int len, i; 503 504 if ((unsigned long)s < PAGE_SIZE) 505 s = "(null)"; 506 507 len = strnlen(s, spec.precision); 508 509 if (!(spec.flags & LEFT)) { 510 while (len < spec.field_width--) { 511 if (buf < end) 512 *buf = ' '; 513 ++buf; 514 } 515 } 516 for (i = 0; i < len; ++i) { 517 if (buf < end) 518 *buf = *s; 519 ++buf; ++s; 520 } 521 while (len < spec.field_width--) { 522 if (buf < end) 523 *buf = ' '; 524 ++buf; 525 } 526 527 return buf; 528 } 529 530 static noinline_for_stack 531 char *symbol_string(char *buf, char *end, void *ptr, 532 struct printf_spec spec, char ext) 533 { 534 unsigned long value = (unsigned long) ptr; 535 #ifdef CONFIG_KALLSYMS 536 char sym[KSYM_SYMBOL_LEN]; 537 if (ext == 'B') 538 sprint_backtrace(sym, value); 539 else if (ext != 'f' && ext != 's') 540 sprint_symbol(sym, value); 541 else 542 sprint_symbol_no_offset(sym, value); 543 544 return string(buf, end, sym, spec); 545 #else 546 spec.field_width = 2 * sizeof(void *); 547 spec.flags |= SPECIAL | SMALL | ZEROPAD; 548 spec.base = 16; 549 550 return number(buf, end, value, spec); 551 #endif 552 } 553 554 static noinline_for_stack 555 char *resource_string(char *buf, char *end, struct resource *res, 556 struct printf_spec spec, const char *fmt) 557 { 558 #ifndef IO_RSRC_PRINTK_SIZE 559 #define IO_RSRC_PRINTK_SIZE 6 560 #endif 561 562 #ifndef MEM_RSRC_PRINTK_SIZE 563 #define MEM_RSRC_PRINTK_SIZE 10 564 #endif 565 static const struct printf_spec io_spec = { 566 .base = 16, 567 .field_width = IO_RSRC_PRINTK_SIZE, 568 .precision = -1, 569 .flags = SPECIAL | SMALL | ZEROPAD, 570 }; 571 static const struct printf_spec mem_spec = { 572 .base = 16, 573 .field_width = MEM_RSRC_PRINTK_SIZE, 574 .precision = -1, 575 .flags = SPECIAL | SMALL | ZEROPAD, 576 }; 577 static const struct printf_spec bus_spec = { 578 .base = 16, 579 .field_width = 2, 580 .precision = -1, 581 .flags = SMALL | ZEROPAD, 582 }; 583 static const struct printf_spec dec_spec = { 584 .base = 10, 585 .precision = -1, 586 .flags = 0, 587 }; 588 static const struct printf_spec str_spec = { 589 .field_width = -1, 590 .precision = 10, 591 .flags = LEFT, 592 }; 593 static const struct printf_spec flag_spec = { 594 .base = 16, 595 .precision = -1, 596 .flags = SPECIAL | SMALL, 597 }; 598 599 /* 32-bit res (sizeof==4): 10 chars in dec, 10 in hex ("0x" + 8) 600 * 64-bit res (sizeof==8): 20 chars in dec, 18 in hex ("0x" + 16) */ 601 #define RSRC_BUF_SIZE ((2 * sizeof(resource_size_t)) + 4) 602 #define FLAG_BUF_SIZE (2 * sizeof(res->flags)) 603 #define DECODED_BUF_SIZE sizeof("[mem - 64bit pref window disabled]") 604 #define RAW_BUF_SIZE sizeof("[mem - flags 0x]") 605 char sym[max(2*RSRC_BUF_SIZE + DECODED_BUF_SIZE, 606 2*RSRC_BUF_SIZE + FLAG_BUF_SIZE + RAW_BUF_SIZE)]; 607 608 char *p = sym, *pend = sym + sizeof(sym); 609 int decode = (fmt[0] == 'R') ? 1 : 0; 610 const struct printf_spec *specp; 611 612 *p++ = '['; 613 if (res->flags & IORESOURCE_IO) { 614 p = string(p, pend, "io ", str_spec); 615 specp = &io_spec; 616 } else if (res->flags & IORESOURCE_MEM) { 617 p = string(p, pend, "mem ", str_spec); 618 specp = &mem_spec; 619 } else if (res->flags & IORESOURCE_IRQ) { 620 p = string(p, pend, "irq ", str_spec); 621 specp = &dec_spec; 622 } else if (res->flags & IORESOURCE_DMA) { 623 p = string(p, pend, "dma ", str_spec); 624 specp = &dec_spec; 625 } else if (res->flags & IORESOURCE_BUS) { 626 p = string(p, pend, "bus ", str_spec); 627 specp = &bus_spec; 628 } else { 629 p = string(p, pend, "??? ", str_spec); 630 specp = &mem_spec; 631 decode = 0; 632 } 633 p = number(p, pend, res->start, *specp); 634 if (res->start != res->end) { 635 *p++ = '-'; 636 p = number(p, pend, res->end, *specp); 637 } 638 if (decode) { 639 if (res->flags & IORESOURCE_MEM_64) 640 p = string(p, pend, " 64bit", str_spec); 641 if (res->flags & IORESOURCE_PREFETCH) 642 p = string(p, pend, " pref", str_spec); 643 if (res->flags & IORESOURCE_WINDOW) 644 p = string(p, pend, " window", str_spec); 645 if (res->flags & IORESOURCE_DISABLED) 646 p = string(p, pend, " disabled", str_spec); 647 } else { 648 p = string(p, pend, " flags ", str_spec); 649 p = number(p, pend, res->flags, flag_spec); 650 } 651 *p++ = ']'; 652 *p = '\0'; 653 654 return string(buf, end, sym, spec); 655 } 656 657 static noinline_for_stack 658 char *hex_string(char *buf, char *end, u8 *addr, struct printf_spec spec, 659 const char *fmt) 660 { 661 int i, len = 1; /* if we pass '%ph[CDN]', field witdh remains 662 negative value, fallback to the default */ 663 char separator; 664 665 if (spec.field_width == 0) 666 /* nothing to print */ 667 return buf; 668 669 if (ZERO_OR_NULL_PTR(addr)) 670 /* NULL pointer */ 671 return string(buf, end, NULL, spec); 672 673 switch (fmt[1]) { 674 case 'C': 675 separator = ':'; 676 break; 677 case 'D': 678 separator = '-'; 679 break; 680 case 'N': 681 separator = 0; 682 break; 683 default: 684 separator = ' '; 685 break; 686 } 687 688 if (spec.field_width > 0) 689 len = min_t(int, spec.field_width, 64); 690 691 for (i = 0; i < len && buf < end - 1; i++) { 692 buf = hex_byte_pack(buf, addr[i]); 693 694 if (buf < end && separator && i != len - 1) 695 *buf++ = separator; 696 } 697 698 return buf; 699 } 700 701 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 bool reversed = false; 710 711 switch (fmt[1]) { 712 case 'F': 713 separator = '-'; 714 break; 715 716 case 'R': 717 reversed = true; 718 /* fall through */ 719 720 default: 721 separator = ':'; 722 break; 723 } 724 725 for (i = 0; i < 6; i++) { 726 if (reversed) 727 p = hex_byte_pack(p, addr[5 - i]); 728 else 729 p = hex_byte_pack(p, addr[i]); 730 731 if (fmt[0] == 'M' && i != 5) 732 *p++ = separator; 733 } 734 *p = '\0'; 735 736 return string(buf, end, mac_addr, spec); 737 } 738 739 static noinline_for_stack 740 char *ip4_string(char *p, const u8 *addr, const char *fmt) 741 { 742 int i; 743 bool leading_zeros = (fmt[0] == 'i'); 744 int index; 745 int step; 746 747 switch (fmt[2]) { 748 case 'h': 749 #ifdef __BIG_ENDIAN 750 index = 0; 751 step = 1; 752 #else 753 index = 3; 754 step = -1; 755 #endif 756 break; 757 case 'l': 758 index = 3; 759 step = -1; 760 break; 761 case 'n': 762 case 'b': 763 default: 764 index = 0; 765 step = 1; 766 break; 767 } 768 for (i = 0; i < 4; i++) { 769 char temp[3]; /* hold each IP quad in reverse order */ 770 int digits = put_dec_trunc8(temp, addr[index]) - temp; 771 if (leading_zeros) { 772 if (digits < 3) 773 *p++ = '0'; 774 if (digits < 2) 775 *p++ = '0'; 776 } 777 /* reverse the digits in the quad */ 778 while (digits--) 779 *p++ = temp[digits]; 780 if (i < 3) 781 *p++ = '.'; 782 index += step; 783 } 784 *p = '\0'; 785 786 return p; 787 } 788 789 static noinline_for_stack 790 char *ip6_compressed_string(char *p, const char *addr) 791 { 792 int i, j, range; 793 unsigned char zerolength[8]; 794 int longest = 1; 795 int colonpos = -1; 796 u16 word; 797 u8 hi, lo; 798 bool needcolon = false; 799 bool useIPv4; 800 struct in6_addr in6; 801 802 memcpy(&in6, addr, sizeof(struct in6_addr)); 803 804 useIPv4 = ipv6_addr_v4mapped(&in6) || ipv6_addr_is_isatap(&in6); 805 806 memset(zerolength, 0, sizeof(zerolength)); 807 808 if (useIPv4) 809 range = 6; 810 else 811 range = 8; 812 813 /* find position of longest 0 run */ 814 for (i = 0; i < range; i++) { 815 for (j = i; j < range; j++) { 816 if (in6.s6_addr16[j] != 0) 817 break; 818 zerolength[i]++; 819 } 820 } 821 for (i = 0; i < range; i++) { 822 if (zerolength[i] > longest) { 823 longest = zerolength[i]; 824 colonpos = i; 825 } 826 } 827 if (longest == 1) /* don't compress a single 0 */ 828 colonpos = -1; 829 830 /* emit address */ 831 for (i = 0; i < range; i++) { 832 if (i == colonpos) { 833 if (needcolon || i == 0) 834 *p++ = ':'; 835 *p++ = ':'; 836 needcolon = false; 837 i += longest - 1; 838 continue; 839 } 840 if (needcolon) { 841 *p++ = ':'; 842 needcolon = false; 843 } 844 /* hex u16 without leading 0s */ 845 word = ntohs(in6.s6_addr16[i]); 846 hi = word >> 8; 847 lo = word & 0xff; 848 if (hi) { 849 if (hi > 0x0f) 850 p = hex_byte_pack(p, hi); 851 else 852 *p++ = hex_asc_lo(hi); 853 p = hex_byte_pack(p, lo); 854 } 855 else if (lo > 0x0f) 856 p = hex_byte_pack(p, lo); 857 else 858 *p++ = hex_asc_lo(lo); 859 needcolon = true; 860 } 861 862 if (useIPv4) { 863 if (needcolon) 864 *p++ = ':'; 865 p = ip4_string(p, &in6.s6_addr[12], "I4"); 866 } 867 *p = '\0'; 868 869 return p; 870 } 871 872 static noinline_for_stack 873 char *ip6_string(char *p, const char *addr, const char *fmt) 874 { 875 int i; 876 877 for (i = 0; i < 8; i++) { 878 p = hex_byte_pack(p, *addr++); 879 p = hex_byte_pack(p, *addr++); 880 if (fmt[0] == 'I' && i != 7) 881 *p++ = ':'; 882 } 883 *p = '\0'; 884 885 return p; 886 } 887 888 static noinline_for_stack 889 char *ip6_addr_string(char *buf, char *end, const u8 *addr, 890 struct printf_spec spec, const char *fmt) 891 { 892 char ip6_addr[sizeof("xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255")]; 893 894 if (fmt[0] == 'I' && fmt[2] == 'c') 895 ip6_compressed_string(ip6_addr, addr); 896 else 897 ip6_string(ip6_addr, addr, fmt); 898 899 return string(buf, end, ip6_addr, spec); 900 } 901 902 static noinline_for_stack 903 char *ip4_addr_string(char *buf, char *end, const u8 *addr, 904 struct printf_spec spec, const char *fmt) 905 { 906 char ip4_addr[sizeof("255.255.255.255")]; 907 908 ip4_string(ip4_addr, addr, fmt); 909 910 return string(buf, end, ip4_addr, spec); 911 } 912 913 static noinline_for_stack 914 char *uuid_string(char *buf, char *end, const u8 *addr, 915 struct printf_spec spec, const char *fmt) 916 { 917 char uuid[sizeof("xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx")]; 918 char *p = uuid; 919 int i; 920 static const u8 be[16] = {0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15}; 921 static const u8 le[16] = {3,2,1,0,5,4,7,6,8,9,10,11,12,13,14,15}; 922 const u8 *index = be; 923 bool uc = false; 924 925 switch (*(++fmt)) { 926 case 'L': 927 uc = true; /* fall-through */ 928 case 'l': 929 index = le; 930 break; 931 case 'B': 932 uc = true; 933 break; 934 } 935 936 for (i = 0; i < 16; i++) { 937 p = hex_byte_pack(p, addr[index[i]]); 938 switch (i) { 939 case 3: 940 case 5: 941 case 7: 942 case 9: 943 *p++ = '-'; 944 break; 945 } 946 } 947 948 *p = 0; 949 950 if (uc) { 951 p = uuid; 952 do { 953 *p = toupper(*p); 954 } while (*(++p)); 955 } 956 957 return string(buf, end, uuid, spec); 958 } 959 960 static 961 char *netdev_feature_string(char *buf, char *end, const u8 *addr, 962 struct printf_spec spec) 963 { 964 spec.flags |= SPECIAL | SMALL | ZEROPAD; 965 if (spec.field_width == -1) 966 spec.field_width = 2 + 2 * sizeof(netdev_features_t); 967 spec.base = 16; 968 969 return number(buf, end, *(const netdev_features_t *)addr, spec); 970 } 971 972 int kptr_restrict __read_mostly; 973 974 /* 975 * Show a '%p' thing. A kernel extension is that the '%p' is followed 976 * by an extra set of alphanumeric characters that are extended format 977 * specifiers. 978 * 979 * Right now we handle: 980 * 981 * - 'F' For symbolic function descriptor pointers with offset 982 * - 'f' For simple symbolic function names without offset 983 * - 'S' For symbolic direct pointers with offset 984 * - 's' For symbolic direct pointers without offset 985 * - 'B' For backtraced symbolic direct pointers with offset 986 * - 'R' For decoded struct resource, e.g., [mem 0x0-0x1f 64bit pref] 987 * - 'r' For raw struct resource, e.g., [mem 0x0-0x1f flags 0x201] 988 * - 'M' For a 6-byte MAC address, it prints the address in the 989 * usual colon-separated hex notation 990 * - 'm' For a 6-byte MAC address, it prints the hex address without colons 991 * - 'MF' For a 6-byte MAC FDDI address, it prints the address 992 * with a dash-separated hex notation 993 * - '[mM]R For a 6-byte MAC address, Reverse order (Bluetooth) 994 * - 'I' [46] for IPv4/IPv6 addresses printed in the usual way 995 * IPv4 uses dot-separated decimal without leading 0's (1.2.3.4) 996 * IPv6 uses colon separated network-order 16 bit hex with leading 0's 997 * - 'i' [46] for 'raw' IPv4/IPv6 addresses 998 * IPv6 omits the colons (01020304...0f) 999 * IPv4 uses dot-separated decimal with leading 0's (010.123.045.006) 1000 * - '[Ii]4[hnbl]' IPv4 addresses in host, network, big or little endian order 1001 * - 'I6c' for IPv6 addresses printed as specified by 1002 * http://tools.ietf.org/html/rfc5952 1003 * - 'U' For a 16 byte UUID/GUID, it prints the UUID/GUID in the form 1004 * "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx" 1005 * Options for %pU are: 1006 * b big endian lower case hex (default) 1007 * B big endian UPPER case hex 1008 * l little endian lower case hex 1009 * L little endian UPPER case hex 1010 * big endian output byte order is: 1011 * [0][1][2][3]-[4][5]-[6][7]-[8][9]-[10][11][12][13][14][15] 1012 * little endian output byte order is: 1013 * [3][2][1][0]-[5][4]-[7][6]-[8][9]-[10][11][12][13][14][15] 1014 * - 'V' For a struct va_format which contains a format string * and va_list *, 1015 * call vsnprintf(->format, *->va_list). 1016 * Implements a "recursive vsnprintf". 1017 * Do not use this feature without some mechanism to verify the 1018 * correctness of the format string and va_list arguments. 1019 * - 'K' For a kernel pointer that should be hidden from unprivileged users 1020 * - 'NF' For a netdev_features_t 1021 * - 'h[CDN]' For a variable-length buffer, it prints it as a hex string with 1022 * a certain separator (' ' by default): 1023 * C colon 1024 * D dash 1025 * N no separator 1026 * The maximum supported length is 64 bytes of the input. Consider 1027 * to use print_hex_dump() for the larger input. 1028 * 1029 * Note: The difference between 'S' and 'F' is that on ia64 and ppc64 1030 * function pointers are really function descriptors, which contain a 1031 * pointer to the real address. 1032 */ 1033 static noinline_for_stack 1034 char *pointer(const char *fmt, char *buf, char *end, void *ptr, 1035 struct printf_spec spec) 1036 { 1037 int default_width = 2 * sizeof(void *) + (spec.flags & SPECIAL ? 2 : 0); 1038 1039 if (!ptr && *fmt != 'K') { 1040 /* 1041 * Print (null) with the same width as a pointer so it makes 1042 * tabular output look nice. 1043 */ 1044 if (spec.field_width == -1) 1045 spec.field_width = default_width; 1046 return string(buf, end, "(null)", spec); 1047 } 1048 1049 switch (*fmt) { 1050 case 'F': 1051 case 'f': 1052 ptr = dereference_function_descriptor(ptr); 1053 /* Fallthrough */ 1054 case 'S': 1055 case 's': 1056 case 'B': 1057 return symbol_string(buf, end, ptr, spec, *fmt); 1058 case 'R': 1059 case 'r': 1060 return resource_string(buf, end, ptr, spec, fmt); 1061 case 'h': 1062 return hex_string(buf, end, ptr, spec, fmt); 1063 case 'M': /* Colon separated: 00:01:02:03:04:05 */ 1064 case 'm': /* Contiguous: 000102030405 */ 1065 /* [mM]F (FDDI) */ 1066 /* [mM]R (Reverse order; Bluetooth) */ 1067 return mac_address_string(buf, end, ptr, spec, fmt); 1068 case 'I': /* Formatted IP supported 1069 * 4: 1.2.3.4 1070 * 6: 0001:0203:...:0708 1071 * 6c: 1::708 or 1::1.2.3.4 1072 */ 1073 case 'i': /* Contiguous: 1074 * 4: 001.002.003.004 1075 * 6: 000102...0f 1076 */ 1077 switch (fmt[1]) { 1078 case '6': 1079 return ip6_addr_string(buf, end, ptr, spec, fmt); 1080 case '4': 1081 return ip4_addr_string(buf, end, ptr, spec, fmt); 1082 } 1083 break; 1084 case 'U': 1085 return uuid_string(buf, end, ptr, spec, fmt); 1086 case 'V': 1087 { 1088 va_list va; 1089 1090 va_copy(va, *((struct va_format *)ptr)->va); 1091 buf += vsnprintf(buf, end > buf ? end - buf : 0, 1092 ((struct va_format *)ptr)->fmt, va); 1093 va_end(va); 1094 return buf; 1095 } 1096 case 'K': 1097 /* 1098 * %pK cannot be used in IRQ context because its test 1099 * for CAP_SYSLOG would be meaningless. 1100 */ 1101 if (kptr_restrict && (in_irq() || in_serving_softirq() || 1102 in_nmi())) { 1103 if (spec.field_width == -1) 1104 spec.field_width = default_width; 1105 return string(buf, end, "pK-error", spec); 1106 } 1107 if (!((kptr_restrict == 0) || 1108 (kptr_restrict == 1 && 1109 has_capability_noaudit(current, CAP_SYSLOG)))) 1110 ptr = NULL; 1111 break; 1112 case 'N': 1113 switch (fmt[1]) { 1114 case 'F': 1115 return netdev_feature_string(buf, end, ptr, spec); 1116 } 1117 break; 1118 } 1119 spec.flags |= SMALL; 1120 if (spec.field_width == -1) { 1121 spec.field_width = default_width; 1122 spec.flags |= ZEROPAD; 1123 } 1124 spec.base = 16; 1125 1126 return number(buf, end, (unsigned long) ptr, spec); 1127 } 1128 1129 /* 1130 * Helper function to decode printf style format. 1131 * Each call decode a token from the format and return the 1132 * number of characters read (or likely the delta where it wants 1133 * to go on the next call). 1134 * The decoded token is returned through the parameters 1135 * 1136 * 'h', 'l', or 'L' for integer fields 1137 * 'z' support added 23/7/1999 S.H. 1138 * 'z' changed to 'Z' --davidm 1/25/99 1139 * 't' added for ptrdiff_t 1140 * 1141 * @fmt: the format string 1142 * @type of the token returned 1143 * @flags: various flags such as +, -, # tokens.. 1144 * @field_width: overwritten width 1145 * @base: base of the number (octal, hex, ...) 1146 * @precision: precision of a number 1147 * @qualifier: qualifier of a number (long, size_t, ...) 1148 */ 1149 static noinline_for_stack 1150 int format_decode(const char *fmt, struct printf_spec *spec) 1151 { 1152 const char *start = fmt; 1153 1154 /* we finished early by reading the field width */ 1155 if (spec->type == FORMAT_TYPE_WIDTH) { 1156 if (spec->field_width < 0) { 1157 spec->field_width = -spec->field_width; 1158 spec->flags |= LEFT; 1159 } 1160 spec->type = FORMAT_TYPE_NONE; 1161 goto precision; 1162 } 1163 1164 /* we finished early by reading the precision */ 1165 if (spec->type == FORMAT_TYPE_PRECISION) { 1166 if (spec->precision < 0) 1167 spec->precision = 0; 1168 1169 spec->type = FORMAT_TYPE_NONE; 1170 goto qualifier; 1171 } 1172 1173 /* By default */ 1174 spec->type = FORMAT_TYPE_NONE; 1175 1176 for (; *fmt ; ++fmt) { 1177 if (*fmt == '%') 1178 break; 1179 } 1180 1181 /* Return the current non-format string */ 1182 if (fmt != start || !*fmt) 1183 return fmt - start; 1184 1185 /* Process flags */ 1186 spec->flags = 0; 1187 1188 while (1) { /* this also skips first '%' */ 1189 bool found = true; 1190 1191 ++fmt; 1192 1193 switch (*fmt) { 1194 case '-': spec->flags |= LEFT; break; 1195 case '+': spec->flags |= PLUS; break; 1196 case ' ': spec->flags |= SPACE; break; 1197 case '#': spec->flags |= SPECIAL; break; 1198 case '0': spec->flags |= ZEROPAD; break; 1199 default: found = false; 1200 } 1201 1202 if (!found) 1203 break; 1204 } 1205 1206 /* get field width */ 1207 spec->field_width = -1; 1208 1209 if (isdigit(*fmt)) 1210 spec->field_width = skip_atoi(&fmt); 1211 else if (*fmt == '*') { 1212 /* it's the next argument */ 1213 spec->type = FORMAT_TYPE_WIDTH; 1214 return ++fmt - start; 1215 } 1216 1217 precision: 1218 /* get the precision */ 1219 spec->precision = -1; 1220 if (*fmt == '.') { 1221 ++fmt; 1222 if (isdigit(*fmt)) { 1223 spec->precision = skip_atoi(&fmt); 1224 if (spec->precision < 0) 1225 spec->precision = 0; 1226 } else if (*fmt == '*') { 1227 /* it's the next argument */ 1228 spec->type = FORMAT_TYPE_PRECISION; 1229 return ++fmt - start; 1230 } 1231 } 1232 1233 qualifier: 1234 /* get the conversion qualifier */ 1235 spec->qualifier = -1; 1236 if (*fmt == 'h' || _tolower(*fmt) == 'l' || 1237 _tolower(*fmt) == 'z' || *fmt == 't') { 1238 spec->qualifier = *fmt++; 1239 if (unlikely(spec->qualifier == *fmt)) { 1240 if (spec->qualifier == 'l') { 1241 spec->qualifier = 'L'; 1242 ++fmt; 1243 } else if (spec->qualifier == 'h') { 1244 spec->qualifier = 'H'; 1245 ++fmt; 1246 } 1247 } 1248 } 1249 1250 /* default base */ 1251 spec->base = 10; 1252 switch (*fmt) { 1253 case 'c': 1254 spec->type = FORMAT_TYPE_CHAR; 1255 return ++fmt - start; 1256 1257 case 's': 1258 spec->type = FORMAT_TYPE_STR; 1259 return ++fmt - start; 1260 1261 case 'p': 1262 spec->type = FORMAT_TYPE_PTR; 1263 return fmt - start; 1264 /* skip alnum */ 1265 1266 case 'n': 1267 spec->type = FORMAT_TYPE_NRCHARS; 1268 return ++fmt - start; 1269 1270 case '%': 1271 spec->type = FORMAT_TYPE_PERCENT_CHAR; 1272 return ++fmt - start; 1273 1274 /* integer number formats - set up the flags and "break" */ 1275 case 'o': 1276 spec->base = 8; 1277 break; 1278 1279 case 'x': 1280 spec->flags |= SMALL; 1281 1282 case 'X': 1283 spec->base = 16; 1284 break; 1285 1286 case 'd': 1287 case 'i': 1288 spec->flags |= SIGN; 1289 case 'u': 1290 break; 1291 1292 default: 1293 spec->type = FORMAT_TYPE_INVALID; 1294 return fmt - start; 1295 } 1296 1297 if (spec->qualifier == 'L') 1298 spec->type = FORMAT_TYPE_LONG_LONG; 1299 else if (spec->qualifier == 'l') { 1300 if (spec->flags & SIGN) 1301 spec->type = FORMAT_TYPE_LONG; 1302 else 1303 spec->type = FORMAT_TYPE_ULONG; 1304 } else if (_tolower(spec->qualifier) == 'z') { 1305 spec->type = FORMAT_TYPE_SIZE_T; 1306 } else if (spec->qualifier == 't') { 1307 spec->type = FORMAT_TYPE_PTRDIFF; 1308 } else if (spec->qualifier == 'H') { 1309 if (spec->flags & SIGN) 1310 spec->type = FORMAT_TYPE_BYTE; 1311 else 1312 spec->type = FORMAT_TYPE_UBYTE; 1313 } else if (spec->qualifier == 'h') { 1314 if (spec->flags & SIGN) 1315 spec->type = FORMAT_TYPE_SHORT; 1316 else 1317 spec->type = FORMAT_TYPE_USHORT; 1318 } else { 1319 if (spec->flags & SIGN) 1320 spec->type = FORMAT_TYPE_INT; 1321 else 1322 spec->type = FORMAT_TYPE_UINT; 1323 } 1324 1325 return ++fmt - start; 1326 } 1327 1328 /** 1329 * vsnprintf - Format a string and place it in a buffer 1330 * @buf: The buffer to place the result into 1331 * @size: The size of the buffer, including the trailing null space 1332 * @fmt: The format string to use 1333 * @args: Arguments for the format string 1334 * 1335 * This function follows C99 vsnprintf, but has some extensions: 1336 * %pS output the name of a text symbol with offset 1337 * %ps output the name of a text symbol without offset 1338 * %pF output the name of a function pointer with its offset 1339 * %pf output the name of a function pointer without its offset 1340 * %pB output the name of a backtrace symbol with its offset 1341 * %pR output the address range in a struct resource with decoded flags 1342 * %pr output the address range in a struct resource with raw flags 1343 * %pM output a 6-byte MAC address with colons 1344 * %pm output a 6-byte MAC address without colons 1345 * %pI4 print an IPv4 address without leading zeros 1346 * %pi4 print an IPv4 address with leading zeros 1347 * %pI6 print an IPv6 address with colons 1348 * %pi6 print an IPv6 address without colons 1349 * %pI6c print an IPv6 address as specified by RFC 5952 1350 * %pU[bBlL] print a UUID/GUID in big or little endian using lower or upper 1351 * case. 1352 * %*ph[CDN] a variable-length hex string with a separator (supports up to 64 1353 * bytes of the input) 1354 * %n is ignored 1355 * 1356 * ** Please update Documentation/printk-formats.txt when making changes ** 1357 * 1358 * The return value is the number of characters which would 1359 * be generated for the given input, excluding the trailing 1360 * '\0', as per ISO C99. If you want to have the exact 1361 * number of characters written into @buf as return value 1362 * (not including the trailing '\0'), use vscnprintf(). If the 1363 * return is greater than or equal to @size, the resulting 1364 * string is truncated. 1365 * 1366 * If you're not already dealing with a va_list consider using snprintf(). 1367 */ 1368 int vsnprintf(char *buf, size_t size, const char *fmt, va_list args) 1369 { 1370 unsigned long long num; 1371 char *str, *end; 1372 struct printf_spec spec = {0}; 1373 1374 /* Reject out-of-range values early. Large positive sizes are 1375 used for unknown buffer sizes. */ 1376 if (WARN_ON_ONCE((int) size < 0)) 1377 return 0; 1378 1379 str = buf; 1380 end = buf + size; 1381 1382 /* Make sure end is always >= buf */ 1383 if (end < buf) { 1384 end = ((void *)-1); 1385 size = end - buf; 1386 } 1387 1388 while (*fmt) { 1389 const char *old_fmt = fmt; 1390 int read = format_decode(fmt, &spec); 1391 1392 fmt += read; 1393 1394 switch (spec.type) { 1395 case FORMAT_TYPE_NONE: { 1396 int copy = read; 1397 if (str < end) { 1398 if (copy > end - str) 1399 copy = end - str; 1400 memcpy(str, old_fmt, copy); 1401 } 1402 str += read; 1403 break; 1404 } 1405 1406 case FORMAT_TYPE_WIDTH: 1407 spec.field_width = va_arg(args, int); 1408 break; 1409 1410 case FORMAT_TYPE_PRECISION: 1411 spec.precision = va_arg(args, int); 1412 break; 1413 1414 case FORMAT_TYPE_CHAR: { 1415 char c; 1416 1417 if (!(spec.flags & LEFT)) { 1418 while (--spec.field_width > 0) { 1419 if (str < end) 1420 *str = ' '; 1421 ++str; 1422 1423 } 1424 } 1425 c = (unsigned char) va_arg(args, int); 1426 if (str < end) 1427 *str = c; 1428 ++str; 1429 while (--spec.field_width > 0) { 1430 if (str < end) 1431 *str = ' '; 1432 ++str; 1433 } 1434 break; 1435 } 1436 1437 case FORMAT_TYPE_STR: 1438 str = string(str, end, va_arg(args, char *), spec); 1439 break; 1440 1441 case FORMAT_TYPE_PTR: 1442 str = pointer(fmt+1, str, end, va_arg(args, void *), 1443 spec); 1444 while (isalnum(*fmt)) 1445 fmt++; 1446 break; 1447 1448 case FORMAT_TYPE_PERCENT_CHAR: 1449 if (str < end) 1450 *str = '%'; 1451 ++str; 1452 break; 1453 1454 case FORMAT_TYPE_INVALID: 1455 if (str < end) 1456 *str = '%'; 1457 ++str; 1458 break; 1459 1460 case FORMAT_TYPE_NRCHARS: { 1461 u8 qualifier = spec.qualifier; 1462 1463 if (qualifier == 'l') { 1464 long *ip = va_arg(args, long *); 1465 *ip = (str - buf); 1466 } else if (_tolower(qualifier) == 'z') { 1467 size_t *ip = va_arg(args, size_t *); 1468 *ip = (str - buf); 1469 } else { 1470 int *ip = va_arg(args, int *); 1471 *ip = (str - buf); 1472 } 1473 break; 1474 } 1475 1476 default: 1477 switch (spec.type) { 1478 case FORMAT_TYPE_LONG_LONG: 1479 num = va_arg(args, long long); 1480 break; 1481 case FORMAT_TYPE_ULONG: 1482 num = va_arg(args, unsigned long); 1483 break; 1484 case FORMAT_TYPE_LONG: 1485 num = va_arg(args, long); 1486 break; 1487 case FORMAT_TYPE_SIZE_T: 1488 num = va_arg(args, size_t); 1489 break; 1490 case FORMAT_TYPE_PTRDIFF: 1491 num = va_arg(args, ptrdiff_t); 1492 break; 1493 case FORMAT_TYPE_UBYTE: 1494 num = (unsigned char) va_arg(args, int); 1495 break; 1496 case FORMAT_TYPE_BYTE: 1497 num = (signed char) va_arg(args, int); 1498 break; 1499 case FORMAT_TYPE_USHORT: 1500 num = (unsigned short) va_arg(args, int); 1501 break; 1502 case FORMAT_TYPE_SHORT: 1503 num = (short) va_arg(args, int); 1504 break; 1505 case FORMAT_TYPE_INT: 1506 num = (int) va_arg(args, int); 1507 break; 1508 default: 1509 num = va_arg(args, unsigned int); 1510 } 1511 1512 str = number(str, end, num, spec); 1513 } 1514 } 1515 1516 if (size > 0) { 1517 if (str < end) 1518 *str = '\0'; 1519 else 1520 end[-1] = '\0'; 1521 } 1522 1523 /* the trailing null byte doesn't count towards the total */ 1524 return str-buf; 1525 1526 } 1527 EXPORT_SYMBOL(vsnprintf); 1528 1529 /** 1530 * vscnprintf - Format a string and place it in a buffer 1531 * @buf: The buffer to place the result into 1532 * @size: The size of the buffer, including the trailing null space 1533 * @fmt: The format string to use 1534 * @args: Arguments for the format string 1535 * 1536 * The return value is the number of characters which have been written into 1537 * the @buf not including the trailing '\0'. If @size is == 0 the function 1538 * returns 0. 1539 * 1540 * If you're not already dealing with a va_list consider using scnprintf(). 1541 * 1542 * See the vsnprintf() documentation for format string extensions over C99. 1543 */ 1544 int vscnprintf(char *buf, size_t size, const char *fmt, va_list args) 1545 { 1546 int i; 1547 1548 i = vsnprintf(buf, size, fmt, args); 1549 1550 if (likely(i < size)) 1551 return i; 1552 if (size != 0) 1553 return size - 1; 1554 return 0; 1555 } 1556 EXPORT_SYMBOL(vscnprintf); 1557 1558 /** 1559 * snprintf - Format a string and place it in a buffer 1560 * @buf: The buffer to place the result into 1561 * @size: The size of the buffer, including the trailing null space 1562 * @fmt: The format string to use 1563 * @...: Arguments for the format string 1564 * 1565 * The return value is the number of characters which would be 1566 * generated for the given input, excluding the trailing null, 1567 * as per ISO C99. If the return is greater than or equal to 1568 * @size, the resulting string is truncated. 1569 * 1570 * See the vsnprintf() documentation for format string extensions over C99. 1571 */ 1572 int snprintf(char *buf, size_t size, const char *fmt, ...) 1573 { 1574 va_list args; 1575 int i; 1576 1577 va_start(args, fmt); 1578 i = vsnprintf(buf, size, fmt, args); 1579 va_end(args); 1580 1581 return i; 1582 } 1583 EXPORT_SYMBOL(snprintf); 1584 1585 /** 1586 * scnprintf - Format a string and place it in a buffer 1587 * @buf: The buffer to place the result into 1588 * @size: The size of the buffer, including the trailing null space 1589 * @fmt: The format string to use 1590 * @...: Arguments for the format string 1591 * 1592 * The return value is the number of characters written into @buf not including 1593 * the trailing '\0'. If @size is == 0 the function returns 0. 1594 */ 1595 1596 int scnprintf(char *buf, size_t size, const char *fmt, ...) 1597 { 1598 va_list args; 1599 int i; 1600 1601 va_start(args, fmt); 1602 i = vscnprintf(buf, size, fmt, args); 1603 va_end(args); 1604 1605 return i; 1606 } 1607 EXPORT_SYMBOL(scnprintf); 1608 1609 /** 1610 * vsprintf - Format a string and place it in a buffer 1611 * @buf: The buffer to place the result into 1612 * @fmt: The format string to use 1613 * @args: Arguments for the format string 1614 * 1615 * The function returns the number of characters written 1616 * into @buf. Use vsnprintf() or vscnprintf() in order to avoid 1617 * buffer overflows. 1618 * 1619 * If you're not already dealing with a va_list consider using sprintf(). 1620 * 1621 * See the vsnprintf() documentation for format string extensions over C99. 1622 */ 1623 int vsprintf(char *buf, const char *fmt, va_list args) 1624 { 1625 return vsnprintf(buf, INT_MAX, fmt, args); 1626 } 1627 EXPORT_SYMBOL(vsprintf); 1628 1629 /** 1630 * sprintf - Format a string and place it in a buffer 1631 * @buf: The buffer to place the result into 1632 * @fmt: The format string to use 1633 * @...: Arguments for the format string 1634 * 1635 * The function returns the number of characters written 1636 * into @buf. Use snprintf() or scnprintf() in order to avoid 1637 * buffer overflows. 1638 * 1639 * See the vsnprintf() documentation for format string extensions over C99. 1640 */ 1641 int sprintf(char *buf, const char *fmt, ...) 1642 { 1643 va_list args; 1644 int i; 1645 1646 va_start(args, fmt); 1647 i = vsnprintf(buf, INT_MAX, fmt, args); 1648 va_end(args); 1649 1650 return i; 1651 } 1652 EXPORT_SYMBOL(sprintf); 1653 1654 #ifdef CONFIG_BINARY_PRINTF 1655 /* 1656 * bprintf service: 1657 * vbin_printf() - VA arguments to binary data 1658 * bstr_printf() - Binary data to text string 1659 */ 1660 1661 /** 1662 * vbin_printf - Parse a format string and place args' binary value in a buffer 1663 * @bin_buf: The buffer to place args' binary value 1664 * @size: The size of the buffer(by words(32bits), not characters) 1665 * @fmt: The format string to use 1666 * @args: Arguments for the format string 1667 * 1668 * The format follows C99 vsnprintf, except %n is ignored, and its argument 1669 * is skiped. 1670 * 1671 * The return value is the number of words(32bits) which would be generated for 1672 * the given input. 1673 * 1674 * NOTE: 1675 * If the return value is greater than @size, the resulting bin_buf is NOT 1676 * valid for bstr_printf(). 1677 */ 1678 int vbin_printf(u32 *bin_buf, size_t size, const char *fmt, va_list args) 1679 { 1680 struct printf_spec spec = {0}; 1681 char *str, *end; 1682 1683 str = (char *)bin_buf; 1684 end = (char *)(bin_buf + size); 1685 1686 #define save_arg(type) \ 1687 do { \ 1688 if (sizeof(type) == 8) { \ 1689 unsigned long long value; \ 1690 str = PTR_ALIGN(str, sizeof(u32)); \ 1691 value = va_arg(args, unsigned long long); \ 1692 if (str + sizeof(type) <= end) { \ 1693 *(u32 *)str = *(u32 *)&value; \ 1694 *(u32 *)(str + 4) = *((u32 *)&value + 1); \ 1695 } \ 1696 } else { \ 1697 unsigned long value; \ 1698 str = PTR_ALIGN(str, sizeof(type)); \ 1699 value = va_arg(args, int); \ 1700 if (str + sizeof(type) <= end) \ 1701 *(typeof(type) *)str = (type)value; \ 1702 } \ 1703 str += sizeof(type); \ 1704 } while (0) 1705 1706 while (*fmt) { 1707 int read = format_decode(fmt, &spec); 1708 1709 fmt += read; 1710 1711 switch (spec.type) { 1712 case FORMAT_TYPE_NONE: 1713 case FORMAT_TYPE_INVALID: 1714 case FORMAT_TYPE_PERCENT_CHAR: 1715 break; 1716 1717 case FORMAT_TYPE_WIDTH: 1718 case FORMAT_TYPE_PRECISION: 1719 save_arg(int); 1720 break; 1721 1722 case FORMAT_TYPE_CHAR: 1723 save_arg(char); 1724 break; 1725 1726 case FORMAT_TYPE_STR: { 1727 const char *save_str = va_arg(args, char *); 1728 size_t len; 1729 1730 if ((unsigned long)save_str > (unsigned long)-PAGE_SIZE 1731 || (unsigned long)save_str < PAGE_SIZE) 1732 save_str = "(null)"; 1733 len = strlen(save_str) + 1; 1734 if (str + len < end) 1735 memcpy(str, save_str, len); 1736 str += len; 1737 break; 1738 } 1739 1740 case FORMAT_TYPE_PTR: 1741 save_arg(void *); 1742 /* skip all alphanumeric pointer suffixes */ 1743 while (isalnum(*fmt)) 1744 fmt++; 1745 break; 1746 1747 case FORMAT_TYPE_NRCHARS: { 1748 /* skip %n 's argument */ 1749 u8 qualifier = spec.qualifier; 1750 void *skip_arg; 1751 if (qualifier == 'l') 1752 skip_arg = va_arg(args, long *); 1753 else if (_tolower(qualifier) == 'z') 1754 skip_arg = va_arg(args, size_t *); 1755 else 1756 skip_arg = va_arg(args, int *); 1757 break; 1758 } 1759 1760 default: 1761 switch (spec.type) { 1762 1763 case FORMAT_TYPE_LONG_LONG: 1764 save_arg(long long); 1765 break; 1766 case FORMAT_TYPE_ULONG: 1767 case FORMAT_TYPE_LONG: 1768 save_arg(unsigned long); 1769 break; 1770 case FORMAT_TYPE_SIZE_T: 1771 save_arg(size_t); 1772 break; 1773 case FORMAT_TYPE_PTRDIFF: 1774 save_arg(ptrdiff_t); 1775 break; 1776 case FORMAT_TYPE_UBYTE: 1777 case FORMAT_TYPE_BYTE: 1778 save_arg(char); 1779 break; 1780 case FORMAT_TYPE_USHORT: 1781 case FORMAT_TYPE_SHORT: 1782 save_arg(short); 1783 break; 1784 default: 1785 save_arg(int); 1786 } 1787 } 1788 } 1789 1790 return (u32 *)(PTR_ALIGN(str, sizeof(u32))) - bin_buf; 1791 #undef save_arg 1792 } 1793 EXPORT_SYMBOL_GPL(vbin_printf); 1794 1795 /** 1796 * bstr_printf - Format a string from binary arguments and place it in a buffer 1797 * @buf: The buffer to place the result into 1798 * @size: The size of the buffer, including the trailing null space 1799 * @fmt: The format string to use 1800 * @bin_buf: Binary arguments for the format string 1801 * 1802 * This function like C99 vsnprintf, but the difference is that vsnprintf gets 1803 * arguments from stack, and bstr_printf gets arguments from @bin_buf which is 1804 * a binary buffer that generated by vbin_printf. 1805 * 1806 * The format follows C99 vsnprintf, but has some extensions: 1807 * see vsnprintf comment for details. 1808 * 1809 * The return value is the number of characters which would 1810 * be generated for the given input, excluding the trailing 1811 * '\0', as per ISO C99. If you want to have the exact 1812 * number of characters written into @buf as return value 1813 * (not including the trailing '\0'), use vscnprintf(). If the 1814 * return is greater than or equal to @size, the resulting 1815 * string is truncated. 1816 */ 1817 int bstr_printf(char *buf, size_t size, const char *fmt, const u32 *bin_buf) 1818 { 1819 struct printf_spec spec = {0}; 1820 char *str, *end; 1821 const char *args = (const char *)bin_buf; 1822 1823 if (WARN_ON_ONCE((int) size < 0)) 1824 return 0; 1825 1826 str = buf; 1827 end = buf + size; 1828 1829 #define get_arg(type) \ 1830 ({ \ 1831 typeof(type) value; \ 1832 if (sizeof(type) == 8) { \ 1833 args = PTR_ALIGN(args, sizeof(u32)); \ 1834 *(u32 *)&value = *(u32 *)args; \ 1835 *((u32 *)&value + 1) = *(u32 *)(args + 4); \ 1836 } else { \ 1837 args = PTR_ALIGN(args, sizeof(type)); \ 1838 value = *(typeof(type) *)args; \ 1839 } \ 1840 args += sizeof(type); \ 1841 value; \ 1842 }) 1843 1844 /* Make sure end is always >= buf */ 1845 if (end < buf) { 1846 end = ((void *)-1); 1847 size = end - buf; 1848 } 1849 1850 while (*fmt) { 1851 const char *old_fmt = fmt; 1852 int read = format_decode(fmt, &spec); 1853 1854 fmt += read; 1855 1856 switch (spec.type) { 1857 case FORMAT_TYPE_NONE: { 1858 int copy = read; 1859 if (str < end) { 1860 if (copy > end - str) 1861 copy = end - str; 1862 memcpy(str, old_fmt, copy); 1863 } 1864 str += read; 1865 break; 1866 } 1867 1868 case FORMAT_TYPE_WIDTH: 1869 spec.field_width = get_arg(int); 1870 break; 1871 1872 case FORMAT_TYPE_PRECISION: 1873 spec.precision = get_arg(int); 1874 break; 1875 1876 case FORMAT_TYPE_CHAR: { 1877 char c; 1878 1879 if (!(spec.flags & LEFT)) { 1880 while (--spec.field_width > 0) { 1881 if (str < end) 1882 *str = ' '; 1883 ++str; 1884 } 1885 } 1886 c = (unsigned char) get_arg(char); 1887 if (str < end) 1888 *str = c; 1889 ++str; 1890 while (--spec.field_width > 0) { 1891 if (str < end) 1892 *str = ' '; 1893 ++str; 1894 } 1895 break; 1896 } 1897 1898 case FORMAT_TYPE_STR: { 1899 const char *str_arg = args; 1900 args += strlen(str_arg) + 1; 1901 str = string(str, end, (char *)str_arg, spec); 1902 break; 1903 } 1904 1905 case FORMAT_TYPE_PTR: 1906 str = pointer(fmt+1, str, end, get_arg(void *), spec); 1907 while (isalnum(*fmt)) 1908 fmt++; 1909 break; 1910 1911 case FORMAT_TYPE_PERCENT_CHAR: 1912 case FORMAT_TYPE_INVALID: 1913 if (str < end) 1914 *str = '%'; 1915 ++str; 1916 break; 1917 1918 case FORMAT_TYPE_NRCHARS: 1919 /* skip */ 1920 break; 1921 1922 default: { 1923 unsigned long long num; 1924 1925 switch (spec.type) { 1926 1927 case FORMAT_TYPE_LONG_LONG: 1928 num = get_arg(long long); 1929 break; 1930 case FORMAT_TYPE_ULONG: 1931 case FORMAT_TYPE_LONG: 1932 num = get_arg(unsigned long); 1933 break; 1934 case FORMAT_TYPE_SIZE_T: 1935 num = get_arg(size_t); 1936 break; 1937 case FORMAT_TYPE_PTRDIFF: 1938 num = get_arg(ptrdiff_t); 1939 break; 1940 case FORMAT_TYPE_UBYTE: 1941 num = get_arg(unsigned char); 1942 break; 1943 case FORMAT_TYPE_BYTE: 1944 num = get_arg(signed char); 1945 break; 1946 case FORMAT_TYPE_USHORT: 1947 num = get_arg(unsigned short); 1948 break; 1949 case FORMAT_TYPE_SHORT: 1950 num = get_arg(short); 1951 break; 1952 case FORMAT_TYPE_UINT: 1953 num = get_arg(unsigned int); 1954 break; 1955 default: 1956 num = get_arg(int); 1957 } 1958 1959 str = number(str, end, num, spec); 1960 } /* default: */ 1961 } /* switch(spec.type) */ 1962 } /* while(*fmt) */ 1963 1964 if (size > 0) { 1965 if (str < end) 1966 *str = '\0'; 1967 else 1968 end[-1] = '\0'; 1969 } 1970 1971 #undef get_arg 1972 1973 /* the trailing null byte doesn't count towards the total */ 1974 return str - buf; 1975 } 1976 EXPORT_SYMBOL_GPL(bstr_printf); 1977 1978 /** 1979 * bprintf - Parse a format string and place args' binary value in a buffer 1980 * @bin_buf: The buffer to place args' binary value 1981 * @size: The size of the buffer(by words(32bits), not characters) 1982 * @fmt: The format string to use 1983 * @...: Arguments for the format string 1984 * 1985 * The function returns the number of words(u32) written 1986 * into @bin_buf. 1987 */ 1988 int bprintf(u32 *bin_buf, size_t size, const char *fmt, ...) 1989 { 1990 va_list args; 1991 int ret; 1992 1993 va_start(args, fmt); 1994 ret = vbin_printf(bin_buf, size, fmt, args); 1995 va_end(args); 1996 1997 return ret; 1998 } 1999 EXPORT_SYMBOL_GPL(bprintf); 2000 2001 #endif /* CONFIG_BINARY_PRINTF */ 2002 2003 /** 2004 * vsscanf - Unformat a buffer into a list of arguments 2005 * @buf: input buffer 2006 * @fmt: format of buffer 2007 * @args: arguments 2008 */ 2009 int vsscanf(const char *buf, const char *fmt, va_list args) 2010 { 2011 const char *str = buf; 2012 char *next; 2013 char digit; 2014 int num = 0; 2015 u8 qualifier; 2016 u8 base; 2017 s16 field_width; 2018 bool is_sign; 2019 2020 while (*fmt && *str) { 2021 /* skip any white space in format */ 2022 /* white space in format matchs any amount of 2023 * white space, including none, in the input. 2024 */ 2025 if (isspace(*fmt)) { 2026 fmt = skip_spaces(++fmt); 2027 str = skip_spaces(str); 2028 } 2029 2030 /* anything that is not a conversion must match exactly */ 2031 if (*fmt != '%' && *fmt) { 2032 if (*fmt++ != *str++) 2033 break; 2034 continue; 2035 } 2036 2037 if (!*fmt) 2038 break; 2039 ++fmt; 2040 2041 /* skip this conversion. 2042 * advance both strings to next white space 2043 */ 2044 if (*fmt == '*') { 2045 while (!isspace(*fmt) && *fmt != '%' && *fmt) 2046 fmt++; 2047 while (!isspace(*str) && *str) 2048 str++; 2049 continue; 2050 } 2051 2052 /* get field width */ 2053 field_width = -1; 2054 if (isdigit(*fmt)) 2055 field_width = skip_atoi(&fmt); 2056 2057 /* get conversion qualifier */ 2058 qualifier = -1; 2059 if (*fmt == 'h' || _tolower(*fmt) == 'l' || 2060 _tolower(*fmt) == 'z') { 2061 qualifier = *fmt++; 2062 if (unlikely(qualifier == *fmt)) { 2063 if (qualifier == 'h') { 2064 qualifier = 'H'; 2065 fmt++; 2066 } else if (qualifier == 'l') { 2067 qualifier = 'L'; 2068 fmt++; 2069 } 2070 } 2071 } 2072 2073 if (!*fmt || !*str) 2074 break; 2075 2076 base = 10; 2077 is_sign = 0; 2078 2079 switch (*fmt++) { 2080 case 'c': 2081 { 2082 char *s = (char *)va_arg(args, char*); 2083 if (field_width == -1) 2084 field_width = 1; 2085 do { 2086 *s++ = *str++; 2087 } while (--field_width > 0 && *str); 2088 num++; 2089 } 2090 continue; 2091 case 's': 2092 { 2093 char *s = (char *)va_arg(args, char *); 2094 if (field_width == -1) 2095 field_width = SHRT_MAX; 2096 /* first, skip leading white space in buffer */ 2097 str = skip_spaces(str); 2098 2099 /* now copy until next white space */ 2100 while (*str && !isspace(*str) && field_width--) 2101 *s++ = *str++; 2102 *s = '\0'; 2103 num++; 2104 } 2105 continue; 2106 case 'n': 2107 /* return number of characters read so far */ 2108 { 2109 int *i = (int *)va_arg(args, int*); 2110 *i = str - buf; 2111 } 2112 continue; 2113 case 'o': 2114 base = 8; 2115 break; 2116 case 'x': 2117 case 'X': 2118 base = 16; 2119 break; 2120 case 'i': 2121 base = 0; 2122 case 'd': 2123 is_sign = 1; 2124 case 'u': 2125 break; 2126 case '%': 2127 /* looking for '%' in str */ 2128 if (*str++ != '%') 2129 return num; 2130 continue; 2131 default: 2132 /* invalid format; stop here */ 2133 return num; 2134 } 2135 2136 /* have some sort of integer conversion. 2137 * first, skip white space in buffer. 2138 */ 2139 str = skip_spaces(str); 2140 2141 digit = *str; 2142 if (is_sign && digit == '-') 2143 digit = *(str + 1); 2144 2145 if (!digit 2146 || (base == 16 && !isxdigit(digit)) 2147 || (base == 10 && !isdigit(digit)) 2148 || (base == 8 && (!isdigit(digit) || digit > '7')) 2149 || (base == 0 && !isdigit(digit))) 2150 break; 2151 2152 switch (qualifier) { 2153 case 'H': /* that's 'hh' in format */ 2154 if (is_sign) { 2155 signed char *s = (signed char *)va_arg(args, signed char *); 2156 *s = (signed char)simple_strtol(str, &next, base); 2157 } else { 2158 unsigned char *s = (unsigned char *)va_arg(args, unsigned char *); 2159 *s = (unsigned char)simple_strtoul(str, &next, base); 2160 } 2161 break; 2162 case 'h': 2163 if (is_sign) { 2164 short *s = (short *)va_arg(args, short *); 2165 *s = (short)simple_strtol(str, &next, base); 2166 } else { 2167 unsigned short *s = (unsigned short *)va_arg(args, unsigned short *); 2168 *s = (unsigned short)simple_strtoul(str, &next, base); 2169 } 2170 break; 2171 case 'l': 2172 if (is_sign) { 2173 long *l = (long *)va_arg(args, long *); 2174 *l = simple_strtol(str, &next, base); 2175 } else { 2176 unsigned long *l = (unsigned long *)va_arg(args, unsigned long *); 2177 *l = simple_strtoul(str, &next, base); 2178 } 2179 break; 2180 case 'L': 2181 if (is_sign) { 2182 long long *l = (long long *)va_arg(args, long long *); 2183 *l = simple_strtoll(str, &next, base); 2184 } else { 2185 unsigned long long *l = (unsigned long long *)va_arg(args, unsigned long long *); 2186 *l = simple_strtoull(str, &next, base); 2187 } 2188 break; 2189 case 'Z': 2190 case 'z': 2191 { 2192 size_t *s = (size_t *)va_arg(args, size_t *); 2193 *s = (size_t)simple_strtoul(str, &next, base); 2194 } 2195 break; 2196 default: 2197 if (is_sign) { 2198 int *i = (int *)va_arg(args, int *); 2199 *i = (int)simple_strtol(str, &next, base); 2200 } else { 2201 unsigned int *i = (unsigned int *)va_arg(args, unsigned int*); 2202 *i = (unsigned int)simple_strtoul(str, &next, base); 2203 } 2204 break; 2205 } 2206 num++; 2207 2208 if (!next) 2209 break; 2210 str = next; 2211 } 2212 2213 /* 2214 * Now we've come all the way through so either the input string or the 2215 * format ended. In the former case, there can be a %n at the current 2216 * position in the format that needs to be filled. 2217 */ 2218 if (*fmt == '%' && *(fmt + 1) == 'n') { 2219 int *p = (int *)va_arg(args, int *); 2220 *p = str - buf; 2221 } 2222 2223 return num; 2224 } 2225 EXPORT_SYMBOL(vsscanf); 2226 2227 /** 2228 * sscanf - Unformat a buffer into a list of arguments 2229 * @buf: input buffer 2230 * @fmt: formatting of buffer 2231 * @...: resulting arguments 2232 */ 2233 int sscanf(const char *buf, const char *fmt, ...) 2234 { 2235 va_list args; 2236 int i; 2237 2238 va_start(args, fmt); 2239 i = vsscanf(buf, fmt, args); 2240 va_end(args); 2241 2242 return i; 2243 } 2244 EXPORT_SYMBOL(sscanf); 2245