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/math64.h> 27 #include <linux/uaccess.h> 28 #include <linux/ioport.h> 29 #include <net/addrconf.h> 30 31 #include <asm/page.h> /* for PAGE_SIZE */ 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pointer to the end of the parsed string will be placed here 40 * @base: The number base to use 41 * 42 * This function is obsolete. Please use kstrtoull instead. 43 */ 44 unsigned long long simple_strtoull(const char *cp, char **endp, unsigned int base) 45 { 46 unsigned long long result; 47 unsigned int rv; 48 49 cp = _parse_integer_fixup_radix(cp, &base); 50 rv = _parse_integer(cp, base, &result); 51 /* FIXME */ 52 cp += (rv & ~KSTRTOX_OVERFLOW); 53 54 if (endp) 55 *endp = (char *)cp; 56 57 return result; 58 } 59 EXPORT_SYMBOL(simple_strtoull); 60 61 /** 62 * simple_strtoul - convert a string to an unsigned long 63 * @cp: The start of the string 64 * @endp: A pointer to the end of the parsed string will be placed here 65 * @base: The number base to use 66 * 67 * This function is obsolete. Please use kstrtoul instead. 68 */ 69 unsigned long simple_strtoul(const char *cp, char **endp, unsigned int base) 70 { 71 return simple_strtoull(cp, endp, base); 72 } 73 EXPORT_SYMBOL(simple_strtoul); 74 75 /** 76 * simple_strtol - convert a string to a signed long 77 * @cp: The start of the string 78 * @endp: A pointer to the end of the parsed string will be placed here 79 * @base: The number base to use 80 * 81 * This function is obsolete. Please use kstrtol instead. 82 */ 83 long simple_strtol(const char *cp, char **endp, unsigned int base) 84 { 85 if (*cp == '-') 86 return -simple_strtoul(cp + 1, endp, base); 87 88 return simple_strtoul(cp, endp, base); 89 } 90 EXPORT_SYMBOL(simple_strtol); 91 92 /** 93 * simple_strtoll - convert a string to a signed long long 94 * @cp: The start of the string 95 * @endp: A pointer to the end of the parsed string will be placed here 96 * @base: The number base to use 97 * 98 * This function is obsolete. Please use kstrtoll instead. 99 */ 100 long long simple_strtoll(const char *cp, char **endp, unsigned int base) 101 { 102 if (*cp == '-') 103 return -simple_strtoull(cp + 1, endp, base); 104 105 return simple_strtoull(cp, endp, base); 106 } 107 EXPORT_SYMBOL(simple_strtoll); 108 109 static noinline_for_stack 110 int skip_atoi(const char **s) 111 { 112 int i = 0; 113 114 while (isdigit(**s)) 115 i = i*10 + *((*s)++) - '0'; 116 117 return i; 118 } 119 120 /* Decimal conversion is by far the most typical, and is used 121 * for /proc and /sys data. This directly impacts e.g. top performance 122 * with many processes running. We optimize it for speed 123 * using ideas described at <http://www.cs.uiowa.edu/~jones/bcd/divide.html> 124 * (with permission from the author, Douglas W. Jones). 125 */ 126 127 #if BITS_PER_LONG != 32 || BITS_PER_LONG_LONG != 64 128 /* Formats correctly any integer in [0, 999999999] */ 129 static noinline_for_stack 130 char *put_dec_full9(char *buf, unsigned q) 131 { 132 unsigned r; 133 134 /* 135 * Possible ways to approx. divide by 10 136 * (x * 0x1999999a) >> 32 x < 1073741829 (multiply must be 64-bit) 137 * (x * 0xcccd) >> 19 x < 81920 (x < 262149 when 64-bit mul) 138 * (x * 0x6667) >> 18 x < 43699 139 * (x * 0x3334) >> 17 x < 16389 140 * (x * 0x199a) >> 16 x < 16389 141 * (x * 0x0ccd) >> 15 x < 16389 142 * (x * 0x0667) >> 14 x < 2739 143 * (x * 0x0334) >> 13 x < 1029 144 * (x * 0x019a) >> 12 x < 1029 145 * (x * 0x00cd) >> 11 x < 1029 shorter code than * 0x67 (on i386) 146 * (x * 0x0067) >> 10 x < 179 147 * (x * 0x0034) >> 9 x < 69 same 148 * (x * 0x001a) >> 8 x < 69 same 149 * (x * 0x000d) >> 7 x < 69 same, shortest code (on i386) 150 * (x * 0x0007) >> 6 x < 19 151 * See <http://www.cs.uiowa.edu/~jones/bcd/divide.html> 152 */ 153 r = (q * (uint64_t)0x1999999a) >> 32; 154 *buf++ = (q - 10 * r) + '0'; /* 1 */ 155 q = (r * (uint64_t)0x1999999a) >> 32; 156 *buf++ = (r - 10 * q) + '0'; /* 2 */ 157 r = (q * (uint64_t)0x1999999a) >> 32; 158 *buf++ = (q - 10 * r) + '0'; /* 3 */ 159 q = (r * (uint64_t)0x1999999a) >> 32; 160 *buf++ = (r - 10 * q) + '0'; /* 4 */ 161 r = (q * (uint64_t)0x1999999a) >> 32; 162 *buf++ = (q - 10 * r) + '0'; /* 5 */ 163 /* Now value is under 10000, can avoid 64-bit multiply */ 164 q = (r * 0x199a) >> 16; 165 *buf++ = (r - 10 * q) + '0'; /* 6 */ 166 r = (q * 0xcd) >> 11; 167 *buf++ = (q - 10 * r) + '0'; /* 7 */ 168 q = (r * 0xcd) >> 11; 169 *buf++ = (r - 10 * q) + '0'; /* 8 */ 170 *buf++ = q + '0'; /* 9 */ 171 return buf; 172 } 173 #endif 174 175 /* Similar to above but do not pad with zeros. 176 * Code can be easily arranged to print 9 digits too, but our callers 177 * always call put_dec_full9() instead when the number has 9 decimal digits. 178 */ 179 static noinline_for_stack 180 char *put_dec_trunc8(char *buf, unsigned r) 181 { 182 unsigned q; 183 184 /* Copy of previous function's body with added early returns */ 185 while (r >= 10000) { 186 q = r + '0'; 187 r = (r * (uint64_t)0x1999999a) >> 32; 188 *buf++ = q - 10*r; 189 } 190 191 q = (r * 0x199a) >> 16; /* r <= 9999 */ 192 *buf++ = (r - 10 * q) + '0'; 193 if (q == 0) 194 return buf; 195 r = (q * 0xcd) >> 11; /* q <= 999 */ 196 *buf++ = (q - 10 * r) + '0'; 197 if (r == 0) 198 return buf; 199 q = (r * 0xcd) >> 11; /* r <= 99 */ 200 *buf++ = (r - 10 * q) + '0'; 201 if (q == 0) 202 return buf; 203 *buf++ = q + '0'; /* q <= 9 */ 204 return buf; 205 } 206 207 /* There are two algorithms to print larger numbers. 208 * One is generic: divide by 1000000000 and repeatedly print 209 * groups of (up to) 9 digits. It's conceptually simple, 210 * but requires a (unsigned long long) / 1000000000 division. 211 * 212 * Second algorithm splits 64-bit unsigned long long into 16-bit chunks, 213 * manipulates them cleverly and generates groups of 4 decimal digits. 214 * It so happens that it does NOT require long long division. 215 * 216 * If long is > 32 bits, division of 64-bit values is relatively easy, 217 * and we will use the first algorithm. 218 * If long long is > 64 bits (strange architecture with VERY large long long), 219 * second algorithm can't be used, and we again use the first one. 220 * 221 * Else (if long is 32 bits and long long is 64 bits) we use second one. 222 */ 223 224 #if BITS_PER_LONG != 32 || BITS_PER_LONG_LONG != 64 225 226 /* First algorithm: generic */ 227 228 static 229 char *put_dec(char *buf, unsigned long long n) 230 { 231 if (n >= 100*1000*1000) { 232 while (n >= 1000*1000*1000) 233 buf = put_dec_full9(buf, do_div(n, 1000*1000*1000)); 234 if (n >= 100*1000*1000) 235 return put_dec_full9(buf, n); 236 } 237 return put_dec_trunc8(buf, n); 238 } 239 240 #else 241 242 /* Second algorithm: valid only for 64-bit long longs */ 243 244 /* See comment in put_dec_full9 for choice of constants */ 245 static noinline_for_stack 246 void put_dec_full4(char *buf, unsigned q) 247 { 248 unsigned r; 249 r = (q * 0xccd) >> 15; 250 buf[0] = (q - 10 * r) + '0'; 251 q = (r * 0xcd) >> 11; 252 buf[1] = (r - 10 * q) + '0'; 253 r = (q * 0xcd) >> 11; 254 buf[2] = (q - 10 * r) + '0'; 255 buf[3] = r + '0'; 256 } 257 258 /* 259 * Call put_dec_full4 on x % 10000, return x / 10000. 260 * The approximation x/10000 == (x * 0x346DC5D7) >> 43 261 * holds for all x < 1,128,869,999. The largest value this 262 * helper will ever be asked to convert is 1,125,520,955. 263 * (d1 in the put_dec code, assuming n is all-ones). 264 */ 265 static 266 unsigned put_dec_helper4(char *buf, unsigned x) 267 { 268 uint32_t q = (x * (uint64_t)0x346DC5D7) >> 43; 269 270 put_dec_full4(buf, x - q * 10000); 271 return q; 272 } 273 274 /* Based on code by Douglas W. Jones found at 275 * <http://www.cs.uiowa.edu/~jones/bcd/decimal.html#sixtyfour> 276 * (with permission from the author). 277 * Performs no 64-bit division and hence should be fast on 32-bit machines. 278 */ 279 static 280 char *put_dec(char *buf, unsigned long long n) 281 { 282 uint32_t d3, d2, d1, q, h; 283 284 if (n < 100*1000*1000) 285 return put_dec_trunc8(buf, n); 286 287 d1 = ((uint32_t)n >> 16); /* implicit "& 0xffff" */ 288 h = (n >> 32); 289 d2 = (h ) & 0xffff; 290 d3 = (h >> 16); /* implicit "& 0xffff" */ 291 292 q = 656 * d3 + 7296 * d2 + 5536 * d1 + ((uint32_t)n & 0xffff); 293 q = put_dec_helper4(buf, q); 294 295 q += 7671 * d3 + 9496 * d2 + 6 * d1; 296 q = put_dec_helper4(buf+4, q); 297 298 q += 4749 * d3 + 42 * d2; 299 q = put_dec_helper4(buf+8, q); 300 301 q += 281 * d3; 302 buf += 12; 303 if (q) 304 buf = put_dec_trunc8(buf, q); 305 else while (buf[-1] == '0') 306 --buf; 307 308 return buf; 309 } 310 311 #endif 312 313 /* 314 * Convert passed number to decimal string. 315 * Returns the length of string. On buffer overflow, returns 0. 316 * 317 * If speed is not important, use snprintf(). It's easy to read the code. 318 */ 319 int num_to_str(char *buf, int size, unsigned long long num) 320 { 321 char tmp[sizeof(num) * 3]; 322 int idx, len; 323 324 /* put_dec() may work incorrectly for num = 0 (generate "", not "0") */ 325 if (num <= 9) { 326 tmp[0] = '0' + num; 327 len = 1; 328 } else { 329 len = put_dec(tmp, num) - tmp; 330 } 331 332 if (len > size) 333 return 0; 334 for (idx = 0; idx < len; ++idx) 335 buf[idx] = tmp[len - idx - 1]; 336 return len; 337 } 338 339 #define ZEROPAD 1 /* pad with zero */ 340 #define SIGN 2 /* unsigned/signed long */ 341 #define PLUS 4 /* show plus */ 342 #define SPACE 8 /* space if plus */ 343 #define LEFT 16 /* left justified */ 344 #define SMALL 32 /* use lowercase in hex (must be 32 == 0x20) */ 345 #define SPECIAL 64 /* prefix hex with "0x", octal with "0" */ 346 347 enum format_type { 348 FORMAT_TYPE_NONE, /* Just a string part */ 349 FORMAT_TYPE_WIDTH, 350 FORMAT_TYPE_PRECISION, 351 FORMAT_TYPE_CHAR, 352 FORMAT_TYPE_STR, 353 FORMAT_TYPE_PTR, 354 FORMAT_TYPE_PERCENT_CHAR, 355 FORMAT_TYPE_INVALID, 356 FORMAT_TYPE_LONG_LONG, 357 FORMAT_TYPE_ULONG, 358 FORMAT_TYPE_LONG, 359 FORMAT_TYPE_UBYTE, 360 FORMAT_TYPE_BYTE, 361 FORMAT_TYPE_USHORT, 362 FORMAT_TYPE_SHORT, 363 FORMAT_TYPE_UINT, 364 FORMAT_TYPE_INT, 365 FORMAT_TYPE_NRCHARS, 366 FORMAT_TYPE_SIZE_T, 367 FORMAT_TYPE_PTRDIFF 368 }; 369 370 struct printf_spec { 371 u8 type; /* format_type enum */ 372 u8 flags; /* flags to number() */ 373 u8 base; /* number base, 8, 10 or 16 only */ 374 u8 qualifier; /* number qualifier, one of 'hHlLtzZ' */ 375 s16 field_width; /* width of output field */ 376 s16 precision; /* # of digits/chars */ 377 }; 378 379 static noinline_for_stack 380 char *number(char *buf, char *end, unsigned long long num, 381 struct printf_spec spec) 382 { 383 /* we are called with base 8, 10 or 16, only, thus don't need "G..." */ 384 static const char digits[16] = "0123456789ABCDEF"; /* "GHIJKLMNOPQRSTUVWXYZ"; */ 385 386 char tmp[66]; 387 char sign; 388 char locase; 389 int need_pfx = ((spec.flags & SPECIAL) && spec.base != 10); 390 int i; 391 bool is_zero = num == 0LL; 392 393 /* locase = 0 or 0x20. ORing digits or letters with 'locase' 394 * produces same digits or (maybe lowercased) letters */ 395 locase = (spec.flags & SMALL); 396 if (spec.flags & LEFT) 397 spec.flags &= ~ZEROPAD; 398 sign = 0; 399 if (spec.flags & SIGN) { 400 if ((signed long long)num < 0) { 401 sign = '-'; 402 num = -(signed long long)num; 403 spec.field_width--; 404 } else if (spec.flags & PLUS) { 405 sign = '+'; 406 spec.field_width--; 407 } else if (spec.flags & SPACE) { 408 sign = ' '; 409 spec.field_width--; 410 } 411 } 412 if (need_pfx) { 413 if (spec.base == 16) 414 spec.field_width -= 2; 415 else if (!is_zero) 416 spec.field_width--; 417 } 418 419 /* generate full string in tmp[], in reverse order */ 420 i = 0; 421 if (num < spec.base) 422 tmp[i++] = digits[num] | locase; 423 /* Generic code, for any base: 424 else do { 425 tmp[i++] = (digits[do_div(num,base)] | locase); 426 } while (num != 0); 427 */ 428 else if (spec.base != 10) { /* 8 or 16 */ 429 int mask = spec.base - 1; 430 int shift = 3; 431 432 if (spec.base == 16) 433 shift = 4; 434 do { 435 tmp[i++] = (digits[((unsigned char)num) & mask] | locase); 436 num >>= shift; 437 } while (num); 438 } else { /* base 10 */ 439 i = put_dec(tmp, num) - tmp; 440 } 441 442 /* printing 100 using %2d gives "100", not "00" */ 443 if (i > spec.precision) 444 spec.precision = i; 445 /* leading space padding */ 446 spec.field_width -= spec.precision; 447 if (!(spec.flags & (ZEROPAD+LEFT))) { 448 while (--spec.field_width >= 0) { 449 if (buf < end) 450 *buf = ' '; 451 ++buf; 452 } 453 } 454 /* sign */ 455 if (sign) { 456 if (buf < end) 457 *buf = sign; 458 ++buf; 459 } 460 /* "0x" / "0" prefix */ 461 if (need_pfx) { 462 if (spec.base == 16 || !is_zero) { 463 if (buf < end) 464 *buf = '0'; 465 ++buf; 466 } 467 if (spec.base == 16) { 468 if (buf < end) 469 *buf = ('X' | locase); 470 ++buf; 471 } 472 } 473 /* zero or space padding */ 474 if (!(spec.flags & LEFT)) { 475 char c = (spec.flags & ZEROPAD) ? '0' : ' '; 476 while (--spec.field_width >= 0) { 477 if (buf < end) 478 *buf = c; 479 ++buf; 480 } 481 } 482 /* hmm even more zero padding? */ 483 while (i <= --spec.precision) { 484 if (buf < end) 485 *buf = '0'; 486 ++buf; 487 } 488 /* actual digits of result */ 489 while (--i >= 0) { 490 if (buf < end) 491 *buf = tmp[i]; 492 ++buf; 493 } 494 /* trailing space padding */ 495 while (--spec.field_width >= 0) { 496 if (buf < end) 497 *buf = ' '; 498 ++buf; 499 } 500 501 return buf; 502 } 503 504 static noinline_for_stack 505 char *string(char *buf, char *end, const char *s, struct printf_spec spec) 506 { 507 int len, i; 508 509 if ((unsigned long)s < PAGE_SIZE) 510 s = "(null)"; 511 512 len = strnlen(s, spec.precision); 513 514 if (!(spec.flags & LEFT)) { 515 while (len < spec.field_width--) { 516 if (buf < end) 517 *buf = ' '; 518 ++buf; 519 } 520 } 521 for (i = 0; i < len; ++i) { 522 if (buf < end) 523 *buf = *s; 524 ++buf; ++s; 525 } 526 while (len < spec.field_width--) { 527 if (buf < end) 528 *buf = ' '; 529 ++buf; 530 } 531 532 return buf; 533 } 534 535 static noinline_for_stack 536 char *symbol_string(char *buf, char *end, void *ptr, 537 struct printf_spec spec, char ext) 538 { 539 unsigned long value = (unsigned long) ptr; 540 #ifdef CONFIG_KALLSYMS 541 char sym[KSYM_SYMBOL_LEN]; 542 if (ext == 'B') 543 sprint_backtrace(sym, value); 544 else if (ext != 'f' && ext != 's') 545 sprint_symbol(sym, value); 546 else 547 sprint_symbol_no_offset(sym, value); 548 549 return string(buf, end, sym, spec); 550 #else 551 spec.field_width = 2 * sizeof(void *); 552 spec.flags |= SPECIAL | SMALL | ZEROPAD; 553 spec.base = 16; 554 555 return number(buf, end, value, spec); 556 #endif 557 } 558 559 static noinline_for_stack 560 char *resource_string(char *buf, char *end, struct resource *res, 561 struct printf_spec spec, const char *fmt) 562 { 563 #ifndef IO_RSRC_PRINTK_SIZE 564 #define IO_RSRC_PRINTK_SIZE 6 565 #endif 566 567 #ifndef MEM_RSRC_PRINTK_SIZE 568 #define MEM_RSRC_PRINTK_SIZE 10 569 #endif 570 static const struct printf_spec io_spec = { 571 .base = 16, 572 .field_width = IO_RSRC_PRINTK_SIZE, 573 .precision = -1, 574 .flags = SPECIAL | SMALL | ZEROPAD, 575 }; 576 static const struct printf_spec mem_spec = { 577 .base = 16, 578 .field_width = MEM_RSRC_PRINTK_SIZE, 579 .precision = -1, 580 .flags = SPECIAL | SMALL | ZEROPAD, 581 }; 582 static const struct printf_spec bus_spec = { 583 .base = 16, 584 .field_width = 2, 585 .precision = -1, 586 .flags = SMALL | ZEROPAD, 587 }; 588 static const struct printf_spec dec_spec = { 589 .base = 10, 590 .precision = -1, 591 .flags = 0, 592 }; 593 static const struct printf_spec str_spec = { 594 .field_width = -1, 595 .precision = 10, 596 .flags = LEFT, 597 }; 598 static const struct printf_spec flag_spec = { 599 .base = 16, 600 .precision = -1, 601 .flags = SPECIAL | SMALL, 602 }; 603 604 /* 32-bit res (sizeof==4): 10 chars in dec, 10 in hex ("0x" + 8) 605 * 64-bit res (sizeof==8): 20 chars in dec, 18 in hex ("0x" + 16) */ 606 #define RSRC_BUF_SIZE ((2 * sizeof(resource_size_t)) + 4) 607 #define FLAG_BUF_SIZE (2 * sizeof(res->flags)) 608 #define DECODED_BUF_SIZE sizeof("[mem - 64bit pref window disabled]") 609 #define RAW_BUF_SIZE sizeof("[mem - flags 0x]") 610 char sym[max(2*RSRC_BUF_SIZE + DECODED_BUF_SIZE, 611 2*RSRC_BUF_SIZE + FLAG_BUF_SIZE + RAW_BUF_SIZE)]; 612 613 char *p = sym, *pend = sym + sizeof(sym); 614 int decode = (fmt[0] == 'R') ? 1 : 0; 615 const struct printf_spec *specp; 616 617 *p++ = '['; 618 if (res->flags & IORESOURCE_IO) { 619 p = string(p, pend, "io ", str_spec); 620 specp = &io_spec; 621 } else if (res->flags & IORESOURCE_MEM) { 622 p = string(p, pend, "mem ", str_spec); 623 specp = &mem_spec; 624 } else if (res->flags & IORESOURCE_IRQ) { 625 p = string(p, pend, "irq ", str_spec); 626 specp = &dec_spec; 627 } else if (res->flags & IORESOURCE_DMA) { 628 p = string(p, pend, "dma ", str_spec); 629 specp = &dec_spec; 630 } else if (res->flags & IORESOURCE_BUS) { 631 p = string(p, pend, "bus ", str_spec); 632 specp = &bus_spec; 633 } else { 634 p = string(p, pend, "??? ", str_spec); 635 specp = &mem_spec; 636 decode = 0; 637 } 638 p = number(p, pend, res->start, *specp); 639 if (res->start != res->end) { 640 *p++ = '-'; 641 p = number(p, pend, res->end, *specp); 642 } 643 if (decode) { 644 if (res->flags & IORESOURCE_MEM_64) 645 p = string(p, pend, " 64bit", str_spec); 646 if (res->flags & IORESOURCE_PREFETCH) 647 p = string(p, pend, " pref", str_spec); 648 if (res->flags & IORESOURCE_WINDOW) 649 p = string(p, pend, " window", str_spec); 650 if (res->flags & IORESOURCE_DISABLED) 651 p = string(p, pend, " disabled", str_spec); 652 } else { 653 p = string(p, pend, " flags ", str_spec); 654 p = number(p, pend, res->flags, flag_spec); 655 } 656 *p++ = ']'; 657 *p = '\0'; 658 659 return string(buf, end, sym, spec); 660 } 661 662 static noinline_for_stack 663 char *hex_string(char *buf, char *end, u8 *addr, struct printf_spec spec, 664 const char *fmt) 665 { 666 int i, len = 1; /* if we pass '%ph[CDN]', field witdh remains 667 negative value, fallback to the default */ 668 char separator; 669 670 if (spec.field_width == 0) 671 /* nothing to print */ 672 return buf; 673 674 if (ZERO_OR_NULL_PTR(addr)) 675 /* NULL pointer */ 676 return string(buf, end, NULL, spec); 677 678 switch (fmt[1]) { 679 case 'C': 680 separator = ':'; 681 break; 682 case 'D': 683 separator = '-'; 684 break; 685 case 'N': 686 separator = 0; 687 break; 688 default: 689 separator = ' '; 690 break; 691 } 692 693 if (spec.field_width > 0) 694 len = min_t(int, spec.field_width, 64); 695 696 for (i = 0; i < len && buf < end - 1; i++) { 697 buf = hex_byte_pack(buf, addr[i]); 698 699 if (buf < end && separator && i != len - 1) 700 *buf++ = separator; 701 } 702 703 return buf; 704 } 705 706 static noinline_for_stack 707 char *mac_address_string(char *buf, char *end, u8 *addr, 708 struct printf_spec spec, const char *fmt) 709 { 710 char mac_addr[sizeof("xx:xx:xx:xx:xx:xx")]; 711 char *p = mac_addr; 712 int i; 713 char separator; 714 bool reversed = false; 715 716 switch (fmt[1]) { 717 case 'F': 718 separator = '-'; 719 break; 720 721 case 'R': 722 reversed = true; 723 /* fall through */ 724 725 default: 726 separator = ':'; 727 break; 728 } 729 730 for (i = 0; i < 6; i++) { 731 if (reversed) 732 p = hex_byte_pack(p, addr[5 - i]); 733 else 734 p = hex_byte_pack(p, addr[i]); 735 736 if (fmt[0] == 'M' && i != 5) 737 *p++ = separator; 738 } 739 *p = '\0'; 740 741 return string(buf, end, mac_addr, spec); 742 } 743 744 static noinline_for_stack 745 char *ip4_string(char *p, const u8 *addr, const char *fmt) 746 { 747 int i; 748 bool leading_zeros = (fmt[0] == 'i'); 749 int index; 750 int step; 751 752 switch (fmt[2]) { 753 case 'h': 754 #ifdef __BIG_ENDIAN 755 index = 0; 756 step = 1; 757 #else 758 index = 3; 759 step = -1; 760 #endif 761 break; 762 case 'l': 763 index = 3; 764 step = -1; 765 break; 766 case 'n': 767 case 'b': 768 default: 769 index = 0; 770 step = 1; 771 break; 772 } 773 for (i = 0; i < 4; i++) { 774 char temp[3]; /* hold each IP quad in reverse order */ 775 int digits = put_dec_trunc8(temp, addr[index]) - temp; 776 if (leading_zeros) { 777 if (digits < 3) 778 *p++ = '0'; 779 if (digits < 2) 780 *p++ = '0'; 781 } 782 /* reverse the digits in the quad */ 783 while (digits--) 784 *p++ = temp[digits]; 785 if (i < 3) 786 *p++ = '.'; 787 index += step; 788 } 789 *p = '\0'; 790 791 return p; 792 } 793 794 static noinline_for_stack 795 char *ip6_compressed_string(char *p, const char *addr) 796 { 797 int i, j, range; 798 unsigned char zerolength[8]; 799 int longest = 1; 800 int colonpos = -1; 801 u16 word; 802 u8 hi, lo; 803 bool needcolon = false; 804 bool useIPv4; 805 struct in6_addr in6; 806 807 memcpy(&in6, addr, sizeof(struct in6_addr)); 808 809 useIPv4 = ipv6_addr_v4mapped(&in6) || ipv6_addr_is_isatap(&in6); 810 811 memset(zerolength, 0, sizeof(zerolength)); 812 813 if (useIPv4) 814 range = 6; 815 else 816 range = 8; 817 818 /* find position of longest 0 run */ 819 for (i = 0; i < range; i++) { 820 for (j = i; j < range; j++) { 821 if (in6.s6_addr16[j] != 0) 822 break; 823 zerolength[i]++; 824 } 825 } 826 for (i = 0; i < range; i++) { 827 if (zerolength[i] > longest) { 828 longest = zerolength[i]; 829 colonpos = i; 830 } 831 } 832 if (longest == 1) /* don't compress a single 0 */ 833 colonpos = -1; 834 835 /* emit address */ 836 for (i = 0; i < range; i++) { 837 if (i == colonpos) { 838 if (needcolon || i == 0) 839 *p++ = ':'; 840 *p++ = ':'; 841 needcolon = false; 842 i += longest - 1; 843 continue; 844 } 845 if (needcolon) { 846 *p++ = ':'; 847 needcolon = false; 848 } 849 /* hex u16 without leading 0s */ 850 word = ntohs(in6.s6_addr16[i]); 851 hi = word >> 8; 852 lo = word & 0xff; 853 if (hi) { 854 if (hi > 0x0f) 855 p = hex_byte_pack(p, hi); 856 else 857 *p++ = hex_asc_lo(hi); 858 p = hex_byte_pack(p, lo); 859 } 860 else if (lo > 0x0f) 861 p = hex_byte_pack(p, lo); 862 else 863 *p++ = hex_asc_lo(lo); 864 needcolon = true; 865 } 866 867 if (useIPv4) { 868 if (needcolon) 869 *p++ = ':'; 870 p = ip4_string(p, &in6.s6_addr[12], "I4"); 871 } 872 *p = '\0'; 873 874 return p; 875 } 876 877 static noinline_for_stack 878 char *ip6_string(char *p, const char *addr, const char *fmt) 879 { 880 int i; 881 882 for (i = 0; i < 8; i++) { 883 p = hex_byte_pack(p, *addr++); 884 p = hex_byte_pack(p, *addr++); 885 if (fmt[0] == 'I' && i != 7) 886 *p++ = ':'; 887 } 888 *p = '\0'; 889 890 return p; 891 } 892 893 static noinline_for_stack 894 char *ip6_addr_string(char *buf, char *end, const u8 *addr, 895 struct printf_spec spec, const char *fmt) 896 { 897 char ip6_addr[sizeof("xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255")]; 898 899 if (fmt[0] == 'I' && fmt[2] == 'c') 900 ip6_compressed_string(ip6_addr, addr); 901 else 902 ip6_string(ip6_addr, addr, fmt); 903 904 return string(buf, end, ip6_addr, spec); 905 } 906 907 static noinline_for_stack 908 char *ip4_addr_string(char *buf, char *end, const u8 *addr, 909 struct printf_spec spec, const char *fmt) 910 { 911 char ip4_addr[sizeof("255.255.255.255")]; 912 913 ip4_string(ip4_addr, addr, fmt); 914 915 return string(buf, end, ip4_addr, spec); 916 } 917 918 static noinline_for_stack 919 char *uuid_string(char *buf, char *end, const u8 *addr, 920 struct printf_spec spec, const char *fmt) 921 { 922 char uuid[sizeof("xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx")]; 923 char *p = uuid; 924 int i; 925 static const u8 be[16] = {0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15}; 926 static const u8 le[16] = {3,2,1,0,5,4,7,6,8,9,10,11,12,13,14,15}; 927 const u8 *index = be; 928 bool uc = false; 929 930 switch (*(++fmt)) { 931 case 'L': 932 uc = true; /* fall-through */ 933 case 'l': 934 index = le; 935 break; 936 case 'B': 937 uc = true; 938 break; 939 } 940 941 for (i = 0; i < 16; i++) { 942 p = hex_byte_pack(p, addr[index[i]]); 943 switch (i) { 944 case 3: 945 case 5: 946 case 7: 947 case 9: 948 *p++ = '-'; 949 break; 950 } 951 } 952 953 *p = 0; 954 955 if (uc) { 956 p = uuid; 957 do { 958 *p = toupper(*p); 959 } while (*(++p)); 960 } 961 962 return string(buf, end, uuid, spec); 963 } 964 965 static 966 char *netdev_feature_string(char *buf, char *end, const u8 *addr, 967 struct printf_spec spec) 968 { 969 spec.flags |= SPECIAL | SMALL | ZEROPAD; 970 if (spec.field_width == -1) 971 spec.field_width = 2 + 2 * sizeof(netdev_features_t); 972 spec.base = 16; 973 974 return number(buf, end, *(const netdev_features_t *)addr, spec); 975 } 976 977 int kptr_restrict __read_mostly; 978 979 /* 980 * Show a '%p' thing. A kernel extension is that the '%p' is followed 981 * by an extra set of alphanumeric characters that are extended format 982 * specifiers. 983 * 984 * Right now we handle: 985 * 986 * - 'F' For symbolic function descriptor pointers with offset 987 * - 'f' For simple symbolic function names without offset 988 * - 'S' For symbolic direct pointers with offset 989 * - 's' For symbolic direct pointers without offset 990 * - 'B' For backtraced symbolic direct pointers with offset 991 * - 'R' For decoded struct resource, e.g., [mem 0x0-0x1f 64bit pref] 992 * - 'r' For raw struct resource, e.g., [mem 0x0-0x1f flags 0x201] 993 * - 'M' For a 6-byte MAC address, it prints the address in the 994 * usual colon-separated hex notation 995 * - 'm' For a 6-byte MAC address, it prints the hex address without colons 996 * - 'MF' For a 6-byte MAC FDDI address, it prints the address 997 * with a dash-separated hex notation 998 * - '[mM]R' For a 6-byte MAC address, Reverse order (Bluetooth) 999 * - 'I' [46] for IPv4/IPv6 addresses printed in the usual way 1000 * IPv4 uses dot-separated decimal without leading 0's (1.2.3.4) 1001 * IPv6 uses colon separated network-order 16 bit hex with leading 0's 1002 * - 'i' [46] for 'raw' IPv4/IPv6 addresses 1003 * IPv6 omits the colons (01020304...0f) 1004 * IPv4 uses dot-separated decimal with leading 0's (010.123.045.006) 1005 * - '[Ii]4[hnbl]' IPv4 addresses in host, network, big or little endian order 1006 * - 'I6c' for IPv6 addresses printed as specified by 1007 * http://tools.ietf.org/html/rfc5952 1008 * - 'U' For a 16 byte UUID/GUID, it prints the UUID/GUID in the form 1009 * "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx" 1010 * Options for %pU are: 1011 * b big endian lower case hex (default) 1012 * B big endian UPPER case hex 1013 * l little endian lower case hex 1014 * L little endian UPPER case hex 1015 * big endian output byte order is: 1016 * [0][1][2][3]-[4][5]-[6][7]-[8][9]-[10][11][12][13][14][15] 1017 * little endian output byte order is: 1018 * [3][2][1][0]-[5][4]-[7][6]-[8][9]-[10][11][12][13][14][15] 1019 * - 'V' For a struct va_format which contains a format string * and va_list *, 1020 * call vsnprintf(->format, *->va_list). 1021 * Implements a "recursive vsnprintf". 1022 * Do not use this feature without some mechanism to verify the 1023 * correctness of the format string and va_list arguments. 1024 * - 'K' For a kernel pointer that should be hidden from unprivileged users 1025 * - 'NF' For a netdev_features_t 1026 * - 'h[CDN]' For a variable-length buffer, it prints it as a hex string with 1027 * a certain separator (' ' by default): 1028 * C colon 1029 * D dash 1030 * N no separator 1031 * The maximum supported length is 64 bytes of the input. Consider 1032 * to use print_hex_dump() for the larger input. 1033 * 1034 * Note: The difference between 'S' and 'F' is that on ia64 and ppc64 1035 * function pointers are really function descriptors, which contain a 1036 * pointer to the real address. 1037 */ 1038 static noinline_for_stack 1039 char *pointer(const char *fmt, char *buf, char *end, void *ptr, 1040 struct printf_spec spec) 1041 { 1042 int default_width = 2 * sizeof(void *) + (spec.flags & SPECIAL ? 2 : 0); 1043 1044 if (!ptr && *fmt != 'K') { 1045 /* 1046 * Print (null) with the same width as a pointer so it makes 1047 * tabular output look nice. 1048 */ 1049 if (spec.field_width == -1) 1050 spec.field_width = default_width; 1051 return string(buf, end, "(null)", spec); 1052 } 1053 1054 switch (*fmt) { 1055 case 'F': 1056 case 'f': 1057 ptr = dereference_function_descriptor(ptr); 1058 /* Fallthrough */ 1059 case 'S': 1060 case 's': 1061 case 'B': 1062 return symbol_string(buf, end, ptr, spec, *fmt); 1063 case 'R': 1064 case 'r': 1065 return resource_string(buf, end, ptr, spec, fmt); 1066 case 'h': 1067 return hex_string(buf, end, ptr, spec, fmt); 1068 case 'M': /* Colon separated: 00:01:02:03:04:05 */ 1069 case 'm': /* Contiguous: 000102030405 */ 1070 /* [mM]F (FDDI) */ 1071 /* [mM]R (Reverse order; Bluetooth) */ 1072 return mac_address_string(buf, end, ptr, spec, fmt); 1073 case 'I': /* Formatted IP supported 1074 * 4: 1.2.3.4 1075 * 6: 0001:0203:...:0708 1076 * 6c: 1::708 or 1::1.2.3.4 1077 */ 1078 case 'i': /* Contiguous: 1079 * 4: 001.002.003.004 1080 * 6: 000102...0f 1081 */ 1082 switch (fmt[1]) { 1083 case '6': 1084 return ip6_addr_string(buf, end, ptr, spec, fmt); 1085 case '4': 1086 return ip4_addr_string(buf, end, ptr, spec, fmt); 1087 } 1088 break; 1089 case 'U': 1090 return uuid_string(buf, end, ptr, spec, fmt); 1091 case 'V': 1092 { 1093 va_list va; 1094 1095 va_copy(va, *((struct va_format *)ptr)->va); 1096 buf += vsnprintf(buf, end > buf ? end - buf : 0, 1097 ((struct va_format *)ptr)->fmt, va); 1098 va_end(va); 1099 return buf; 1100 } 1101 case 'K': 1102 /* 1103 * %pK cannot be used in IRQ context because its test 1104 * for CAP_SYSLOG would be meaningless. 1105 */ 1106 if (kptr_restrict && (in_irq() || in_serving_softirq() || 1107 in_nmi())) { 1108 if (spec.field_width == -1) 1109 spec.field_width = default_width; 1110 return string(buf, end, "pK-error", spec); 1111 } 1112 if (!((kptr_restrict == 0) || 1113 (kptr_restrict == 1 && 1114 has_capability_noaudit(current, CAP_SYSLOG)))) 1115 ptr = NULL; 1116 break; 1117 case 'N': 1118 switch (fmt[1]) { 1119 case 'F': 1120 return netdev_feature_string(buf, end, ptr, spec); 1121 } 1122 break; 1123 } 1124 spec.flags |= SMALL; 1125 if (spec.field_width == -1) { 1126 spec.field_width = default_width; 1127 spec.flags |= ZEROPAD; 1128 } 1129 spec.base = 16; 1130 1131 return number(buf, end, (unsigned long) ptr, spec); 1132 } 1133 1134 /* 1135 * Helper function to decode printf style format. 1136 * Each call decode a token from the format and return the 1137 * number of characters read (or likely the delta where it wants 1138 * to go on the next call). 1139 * The decoded token is returned through the parameters 1140 * 1141 * 'h', 'l', or 'L' for integer fields 1142 * 'z' support added 23/7/1999 S.H. 1143 * 'z' changed to 'Z' --davidm 1/25/99 1144 * 't' added for ptrdiff_t 1145 * 1146 * @fmt: the format string 1147 * @type of the token returned 1148 * @flags: various flags such as +, -, # tokens.. 1149 * @field_width: overwritten width 1150 * @base: base of the number (octal, hex, ...) 1151 * @precision: precision of a number 1152 * @qualifier: qualifier of a number (long, size_t, ...) 1153 */ 1154 static noinline_for_stack 1155 int format_decode(const char *fmt, struct printf_spec *spec) 1156 { 1157 const char *start = fmt; 1158 1159 /* we finished early by reading the field width */ 1160 if (spec->type == FORMAT_TYPE_WIDTH) { 1161 if (spec->field_width < 0) { 1162 spec->field_width = -spec->field_width; 1163 spec->flags |= LEFT; 1164 } 1165 spec->type = FORMAT_TYPE_NONE; 1166 goto precision; 1167 } 1168 1169 /* we finished early by reading the precision */ 1170 if (spec->type == FORMAT_TYPE_PRECISION) { 1171 if (spec->precision < 0) 1172 spec->precision = 0; 1173 1174 spec->type = FORMAT_TYPE_NONE; 1175 goto qualifier; 1176 } 1177 1178 /* By default */ 1179 spec->type = FORMAT_TYPE_NONE; 1180 1181 for (; *fmt ; ++fmt) { 1182 if (*fmt == '%') 1183 break; 1184 } 1185 1186 /* Return the current non-format string */ 1187 if (fmt != start || !*fmt) 1188 return fmt - start; 1189 1190 /* Process flags */ 1191 spec->flags = 0; 1192 1193 while (1) { /* this also skips first '%' */ 1194 bool found = true; 1195 1196 ++fmt; 1197 1198 switch (*fmt) { 1199 case '-': spec->flags |= LEFT; break; 1200 case '+': spec->flags |= PLUS; break; 1201 case ' ': spec->flags |= SPACE; break; 1202 case '#': spec->flags |= SPECIAL; break; 1203 case '0': spec->flags |= ZEROPAD; break; 1204 default: found = false; 1205 } 1206 1207 if (!found) 1208 break; 1209 } 1210 1211 /* get field width */ 1212 spec->field_width = -1; 1213 1214 if (isdigit(*fmt)) 1215 spec->field_width = skip_atoi(&fmt); 1216 else if (*fmt == '*') { 1217 /* it's the next argument */ 1218 spec->type = FORMAT_TYPE_WIDTH; 1219 return ++fmt - start; 1220 } 1221 1222 precision: 1223 /* get the precision */ 1224 spec->precision = -1; 1225 if (*fmt == '.') { 1226 ++fmt; 1227 if (isdigit(*fmt)) { 1228 spec->precision = skip_atoi(&fmt); 1229 if (spec->precision < 0) 1230 spec->precision = 0; 1231 } else if (*fmt == '*') { 1232 /* it's the next argument */ 1233 spec->type = FORMAT_TYPE_PRECISION; 1234 return ++fmt - start; 1235 } 1236 } 1237 1238 qualifier: 1239 /* get the conversion qualifier */ 1240 spec->qualifier = -1; 1241 if (*fmt == 'h' || _tolower(*fmt) == 'l' || 1242 _tolower(*fmt) == 'z' || *fmt == 't') { 1243 spec->qualifier = *fmt++; 1244 if (unlikely(spec->qualifier == *fmt)) { 1245 if (spec->qualifier == 'l') { 1246 spec->qualifier = 'L'; 1247 ++fmt; 1248 } else if (spec->qualifier == 'h') { 1249 spec->qualifier = 'H'; 1250 ++fmt; 1251 } 1252 } 1253 } 1254 1255 /* default base */ 1256 spec->base = 10; 1257 switch (*fmt) { 1258 case 'c': 1259 spec->type = FORMAT_TYPE_CHAR; 1260 return ++fmt - start; 1261 1262 case 's': 1263 spec->type = FORMAT_TYPE_STR; 1264 return ++fmt - start; 1265 1266 case 'p': 1267 spec->type = FORMAT_TYPE_PTR; 1268 return fmt - start; 1269 /* skip alnum */ 1270 1271 case 'n': 1272 spec->type = FORMAT_TYPE_NRCHARS; 1273 return ++fmt - start; 1274 1275 case '%': 1276 spec->type = FORMAT_TYPE_PERCENT_CHAR; 1277 return ++fmt - start; 1278 1279 /* integer number formats - set up the flags and "break" */ 1280 case 'o': 1281 spec->base = 8; 1282 break; 1283 1284 case 'x': 1285 spec->flags |= SMALL; 1286 1287 case 'X': 1288 spec->base = 16; 1289 break; 1290 1291 case 'd': 1292 case 'i': 1293 spec->flags |= SIGN; 1294 case 'u': 1295 break; 1296 1297 default: 1298 spec->type = FORMAT_TYPE_INVALID; 1299 return fmt - start; 1300 } 1301 1302 if (spec->qualifier == 'L') 1303 spec->type = FORMAT_TYPE_LONG_LONG; 1304 else if (spec->qualifier == 'l') { 1305 if (spec->flags & SIGN) 1306 spec->type = FORMAT_TYPE_LONG; 1307 else 1308 spec->type = FORMAT_TYPE_ULONG; 1309 } else if (_tolower(spec->qualifier) == 'z') { 1310 spec->type = FORMAT_TYPE_SIZE_T; 1311 } else if (spec->qualifier == 't') { 1312 spec->type = FORMAT_TYPE_PTRDIFF; 1313 } else if (spec->qualifier == 'H') { 1314 if (spec->flags & SIGN) 1315 spec->type = FORMAT_TYPE_BYTE; 1316 else 1317 spec->type = FORMAT_TYPE_UBYTE; 1318 } else if (spec->qualifier == 'h') { 1319 if (spec->flags & SIGN) 1320 spec->type = FORMAT_TYPE_SHORT; 1321 else 1322 spec->type = FORMAT_TYPE_USHORT; 1323 } else { 1324 if (spec->flags & SIGN) 1325 spec->type = FORMAT_TYPE_INT; 1326 else 1327 spec->type = FORMAT_TYPE_UINT; 1328 } 1329 1330 return ++fmt - start; 1331 } 1332 1333 /** 1334 * vsnprintf - Format a string and place it in a buffer 1335 * @buf: The buffer to place the result into 1336 * @size: The size of the buffer, including the trailing null space 1337 * @fmt: The format string to use 1338 * @args: Arguments for the format string 1339 * 1340 * This function follows C99 vsnprintf, but has some extensions: 1341 * %pS output the name of a text symbol with offset 1342 * %ps output the name of a text symbol without offset 1343 * %pF output the name of a function pointer with its offset 1344 * %pf output the name of a function pointer without its offset 1345 * %pB output the name of a backtrace symbol with its offset 1346 * %pR output the address range in a struct resource with decoded flags 1347 * %pr output the address range in a struct resource with raw flags 1348 * %pM output a 6-byte MAC address with colons 1349 * %pMR output a 6-byte MAC address with colons in reversed order 1350 * %pMF output a 6-byte MAC address with dashes 1351 * %pm output a 6-byte MAC address without colons 1352 * %pmR output a 6-byte MAC address without colons in reversed order 1353 * %pI4 print an IPv4 address without leading zeros 1354 * %pi4 print an IPv4 address with leading zeros 1355 * %pI6 print an IPv6 address with colons 1356 * %pi6 print an IPv6 address without colons 1357 * %pI6c print an IPv6 address as specified by RFC 5952 1358 * %pU[bBlL] print a UUID/GUID in big or little endian using lower or upper 1359 * case. 1360 * %*ph[CDN] a variable-length hex string with a separator (supports up to 64 1361 * bytes of the input) 1362 * %n is ignored 1363 * 1364 * ** Please update Documentation/printk-formats.txt when making changes ** 1365 * 1366 * The return value is the number of characters which would 1367 * be generated for the given input, excluding the trailing 1368 * '\0', as per ISO C99. If you want to have the exact 1369 * number of characters written into @buf as return value 1370 * (not including the trailing '\0'), use vscnprintf(). If the 1371 * return is greater than or equal to @size, the resulting 1372 * string is truncated. 1373 * 1374 * If you're not already dealing with a va_list consider using snprintf(). 1375 */ 1376 int vsnprintf(char *buf, size_t size, const char *fmt, va_list args) 1377 { 1378 unsigned long long num; 1379 char *str, *end; 1380 struct printf_spec spec = {0}; 1381 1382 /* Reject out-of-range values early. Large positive sizes are 1383 used for unknown buffer sizes. */ 1384 if (WARN_ON_ONCE((int) size < 0)) 1385 return 0; 1386 1387 str = buf; 1388 end = buf + size; 1389 1390 /* Make sure end is always >= buf */ 1391 if (end < buf) { 1392 end = ((void *)-1); 1393 size = end - buf; 1394 } 1395 1396 while (*fmt) { 1397 const char *old_fmt = fmt; 1398 int read = format_decode(fmt, &spec); 1399 1400 fmt += read; 1401 1402 switch (spec.type) { 1403 case FORMAT_TYPE_NONE: { 1404 int copy = read; 1405 if (str < end) { 1406 if (copy > end - str) 1407 copy = end - str; 1408 memcpy(str, old_fmt, copy); 1409 } 1410 str += read; 1411 break; 1412 } 1413 1414 case FORMAT_TYPE_WIDTH: 1415 spec.field_width = va_arg(args, int); 1416 break; 1417 1418 case FORMAT_TYPE_PRECISION: 1419 spec.precision = va_arg(args, int); 1420 break; 1421 1422 case FORMAT_TYPE_CHAR: { 1423 char c; 1424 1425 if (!(spec.flags & LEFT)) { 1426 while (--spec.field_width > 0) { 1427 if (str < end) 1428 *str = ' '; 1429 ++str; 1430 1431 } 1432 } 1433 c = (unsigned char) va_arg(args, int); 1434 if (str < end) 1435 *str = c; 1436 ++str; 1437 while (--spec.field_width > 0) { 1438 if (str < end) 1439 *str = ' '; 1440 ++str; 1441 } 1442 break; 1443 } 1444 1445 case FORMAT_TYPE_STR: 1446 str = string(str, end, va_arg(args, char *), spec); 1447 break; 1448 1449 case FORMAT_TYPE_PTR: 1450 str = pointer(fmt+1, str, end, va_arg(args, void *), 1451 spec); 1452 while (isalnum(*fmt)) 1453 fmt++; 1454 break; 1455 1456 case FORMAT_TYPE_PERCENT_CHAR: 1457 if (str < end) 1458 *str = '%'; 1459 ++str; 1460 break; 1461 1462 case FORMAT_TYPE_INVALID: 1463 if (str < end) 1464 *str = '%'; 1465 ++str; 1466 break; 1467 1468 case FORMAT_TYPE_NRCHARS: { 1469 u8 qualifier = spec.qualifier; 1470 1471 if (qualifier == 'l') { 1472 long *ip = va_arg(args, long *); 1473 *ip = (str - buf); 1474 } else if (_tolower(qualifier) == 'z') { 1475 size_t *ip = va_arg(args, size_t *); 1476 *ip = (str - buf); 1477 } else { 1478 int *ip = va_arg(args, int *); 1479 *ip = (str - buf); 1480 } 1481 break; 1482 } 1483 1484 default: 1485 switch (spec.type) { 1486 case FORMAT_TYPE_LONG_LONG: 1487 num = va_arg(args, long long); 1488 break; 1489 case FORMAT_TYPE_ULONG: 1490 num = va_arg(args, unsigned long); 1491 break; 1492 case FORMAT_TYPE_LONG: 1493 num = va_arg(args, long); 1494 break; 1495 case FORMAT_TYPE_SIZE_T: 1496 if (spec.flags & SIGN) 1497 num = va_arg(args, ssize_t); 1498 else 1499 num = va_arg(args, size_t); 1500 break; 1501 case FORMAT_TYPE_PTRDIFF: 1502 num = va_arg(args, ptrdiff_t); 1503 break; 1504 case FORMAT_TYPE_UBYTE: 1505 num = (unsigned char) va_arg(args, int); 1506 break; 1507 case FORMAT_TYPE_BYTE: 1508 num = (signed char) va_arg(args, int); 1509 break; 1510 case FORMAT_TYPE_USHORT: 1511 num = (unsigned short) va_arg(args, int); 1512 break; 1513 case FORMAT_TYPE_SHORT: 1514 num = (short) va_arg(args, int); 1515 break; 1516 case FORMAT_TYPE_INT: 1517 num = (int) va_arg(args, int); 1518 break; 1519 default: 1520 num = va_arg(args, unsigned int); 1521 } 1522 1523 str = number(str, end, num, spec); 1524 } 1525 } 1526 1527 if (size > 0) { 1528 if (str < end) 1529 *str = '\0'; 1530 else 1531 end[-1] = '\0'; 1532 } 1533 1534 /* the trailing null byte doesn't count towards the total */ 1535 return str-buf; 1536 1537 } 1538 EXPORT_SYMBOL(vsnprintf); 1539 1540 /** 1541 * vscnprintf - Format a string and place it in a buffer 1542 * @buf: The buffer to place the result into 1543 * @size: The size of the buffer, including the trailing null space 1544 * @fmt: The format string to use 1545 * @args: Arguments for the format string 1546 * 1547 * The return value is the number of characters which have been written into 1548 * the @buf not including the trailing '\0'. If @size is == 0 the function 1549 * returns 0. 1550 * 1551 * If you're not already dealing with a va_list consider using scnprintf(). 1552 * 1553 * See the vsnprintf() documentation for format string extensions over C99. 1554 */ 1555 int vscnprintf(char *buf, size_t size, const char *fmt, va_list args) 1556 { 1557 int i; 1558 1559 i = vsnprintf(buf, size, fmt, args); 1560 1561 if (likely(i < size)) 1562 return i; 1563 if (size != 0) 1564 return size - 1; 1565 return 0; 1566 } 1567 EXPORT_SYMBOL(vscnprintf); 1568 1569 /** 1570 * snprintf - Format a string and place it in a buffer 1571 * @buf: The buffer to place the result into 1572 * @size: The size of the buffer, including the trailing null space 1573 * @fmt: The format string to use 1574 * @...: Arguments for the format string 1575 * 1576 * The return value is the number of characters which would be 1577 * generated for the given input, excluding the trailing null, 1578 * as per ISO C99. If the return is greater than or equal to 1579 * @size, the resulting string is truncated. 1580 * 1581 * See the vsnprintf() documentation for format string extensions over C99. 1582 */ 1583 int snprintf(char *buf, size_t size, const char *fmt, ...) 1584 { 1585 va_list args; 1586 int i; 1587 1588 va_start(args, fmt); 1589 i = vsnprintf(buf, size, fmt, args); 1590 va_end(args); 1591 1592 return i; 1593 } 1594 EXPORT_SYMBOL(snprintf); 1595 1596 /** 1597 * scnprintf - Format a string and place it in a buffer 1598 * @buf: The buffer to place the result into 1599 * @size: The size of the buffer, including the trailing null space 1600 * @fmt: The format string to use 1601 * @...: Arguments for the format string 1602 * 1603 * The return value is the number of characters written into @buf not including 1604 * the trailing '\0'. If @size is == 0 the function returns 0. 1605 */ 1606 1607 int scnprintf(char *buf, size_t size, const char *fmt, ...) 1608 { 1609 va_list args; 1610 int i; 1611 1612 va_start(args, fmt); 1613 i = vscnprintf(buf, size, fmt, args); 1614 va_end(args); 1615 1616 return i; 1617 } 1618 EXPORT_SYMBOL(scnprintf); 1619 1620 /** 1621 * vsprintf - Format a string and place it in a buffer 1622 * @buf: The buffer to place the result into 1623 * @fmt: The format string to use 1624 * @args: Arguments for the format string 1625 * 1626 * The function returns the number of characters written 1627 * into @buf. Use vsnprintf() or vscnprintf() in order to avoid 1628 * buffer overflows. 1629 * 1630 * If you're not already dealing with a va_list consider using sprintf(). 1631 * 1632 * See the vsnprintf() documentation for format string extensions over C99. 1633 */ 1634 int vsprintf(char *buf, const char *fmt, va_list args) 1635 { 1636 return vsnprintf(buf, INT_MAX, fmt, args); 1637 } 1638 EXPORT_SYMBOL(vsprintf); 1639 1640 /** 1641 * sprintf - Format a string and place it in a buffer 1642 * @buf: The buffer to place the result into 1643 * @fmt: The format string to use 1644 * @...: Arguments for the format string 1645 * 1646 * The function returns the number of characters written 1647 * into @buf. Use snprintf() or scnprintf() in order to avoid 1648 * buffer overflows. 1649 * 1650 * See the vsnprintf() documentation for format string extensions over C99. 1651 */ 1652 int sprintf(char *buf, const char *fmt, ...) 1653 { 1654 va_list args; 1655 int i; 1656 1657 va_start(args, fmt); 1658 i = vsnprintf(buf, INT_MAX, fmt, args); 1659 va_end(args); 1660 1661 return i; 1662 } 1663 EXPORT_SYMBOL(sprintf); 1664 1665 #ifdef CONFIG_BINARY_PRINTF 1666 /* 1667 * bprintf service: 1668 * vbin_printf() - VA arguments to binary data 1669 * bstr_printf() - Binary data to text string 1670 */ 1671 1672 /** 1673 * vbin_printf - Parse a format string and place args' binary value in a buffer 1674 * @bin_buf: The buffer to place args' binary value 1675 * @size: The size of the buffer(by words(32bits), not characters) 1676 * @fmt: The format string to use 1677 * @args: Arguments for the format string 1678 * 1679 * The format follows C99 vsnprintf, except %n is ignored, and its argument 1680 * is skiped. 1681 * 1682 * The return value is the number of words(32bits) which would be generated for 1683 * the given input. 1684 * 1685 * NOTE: 1686 * If the return value is greater than @size, the resulting bin_buf is NOT 1687 * valid for bstr_printf(). 1688 */ 1689 int vbin_printf(u32 *bin_buf, size_t size, const char *fmt, va_list args) 1690 { 1691 struct printf_spec spec = {0}; 1692 char *str, *end; 1693 1694 str = (char *)bin_buf; 1695 end = (char *)(bin_buf + size); 1696 1697 #define save_arg(type) \ 1698 do { \ 1699 if (sizeof(type) == 8) { \ 1700 unsigned long long value; \ 1701 str = PTR_ALIGN(str, sizeof(u32)); \ 1702 value = va_arg(args, unsigned long long); \ 1703 if (str + sizeof(type) <= end) { \ 1704 *(u32 *)str = *(u32 *)&value; \ 1705 *(u32 *)(str + 4) = *((u32 *)&value + 1); \ 1706 } \ 1707 } else { \ 1708 unsigned long value; \ 1709 str = PTR_ALIGN(str, sizeof(type)); \ 1710 value = va_arg(args, int); \ 1711 if (str + sizeof(type) <= end) \ 1712 *(typeof(type) *)str = (type)value; \ 1713 } \ 1714 str += sizeof(type); \ 1715 } while (0) 1716 1717 while (*fmt) { 1718 int read = format_decode(fmt, &spec); 1719 1720 fmt += read; 1721 1722 switch (spec.type) { 1723 case FORMAT_TYPE_NONE: 1724 case FORMAT_TYPE_INVALID: 1725 case FORMAT_TYPE_PERCENT_CHAR: 1726 break; 1727 1728 case FORMAT_TYPE_WIDTH: 1729 case FORMAT_TYPE_PRECISION: 1730 save_arg(int); 1731 break; 1732 1733 case FORMAT_TYPE_CHAR: 1734 save_arg(char); 1735 break; 1736 1737 case FORMAT_TYPE_STR: { 1738 const char *save_str = va_arg(args, char *); 1739 size_t len; 1740 1741 if ((unsigned long)save_str > (unsigned long)-PAGE_SIZE 1742 || (unsigned long)save_str < PAGE_SIZE) 1743 save_str = "(null)"; 1744 len = strlen(save_str) + 1; 1745 if (str + len < end) 1746 memcpy(str, save_str, len); 1747 str += len; 1748 break; 1749 } 1750 1751 case FORMAT_TYPE_PTR: 1752 save_arg(void *); 1753 /* skip all alphanumeric pointer suffixes */ 1754 while (isalnum(*fmt)) 1755 fmt++; 1756 break; 1757 1758 case FORMAT_TYPE_NRCHARS: { 1759 /* skip %n 's argument */ 1760 u8 qualifier = spec.qualifier; 1761 void *skip_arg; 1762 if (qualifier == 'l') 1763 skip_arg = va_arg(args, long *); 1764 else if (_tolower(qualifier) == 'z') 1765 skip_arg = va_arg(args, size_t *); 1766 else 1767 skip_arg = va_arg(args, int *); 1768 break; 1769 } 1770 1771 default: 1772 switch (spec.type) { 1773 1774 case FORMAT_TYPE_LONG_LONG: 1775 save_arg(long long); 1776 break; 1777 case FORMAT_TYPE_ULONG: 1778 case FORMAT_TYPE_LONG: 1779 save_arg(unsigned long); 1780 break; 1781 case FORMAT_TYPE_SIZE_T: 1782 save_arg(size_t); 1783 break; 1784 case FORMAT_TYPE_PTRDIFF: 1785 save_arg(ptrdiff_t); 1786 break; 1787 case FORMAT_TYPE_UBYTE: 1788 case FORMAT_TYPE_BYTE: 1789 save_arg(char); 1790 break; 1791 case FORMAT_TYPE_USHORT: 1792 case FORMAT_TYPE_SHORT: 1793 save_arg(short); 1794 break; 1795 default: 1796 save_arg(int); 1797 } 1798 } 1799 } 1800 1801 return (u32 *)(PTR_ALIGN(str, sizeof(u32))) - bin_buf; 1802 #undef save_arg 1803 } 1804 EXPORT_SYMBOL_GPL(vbin_printf); 1805 1806 /** 1807 * bstr_printf - Format a string from binary arguments and place it in a buffer 1808 * @buf: The buffer to place the result into 1809 * @size: The size of the buffer, including the trailing null space 1810 * @fmt: The format string to use 1811 * @bin_buf: Binary arguments for the format string 1812 * 1813 * This function like C99 vsnprintf, but the difference is that vsnprintf gets 1814 * arguments from stack, and bstr_printf gets arguments from @bin_buf which is 1815 * a binary buffer that generated by vbin_printf. 1816 * 1817 * The format follows C99 vsnprintf, but has some extensions: 1818 * see vsnprintf comment for details. 1819 * 1820 * The return value is the number of characters which would 1821 * be generated for the given input, excluding the trailing 1822 * '\0', as per ISO C99. If you want to have the exact 1823 * number of characters written into @buf as return value 1824 * (not including the trailing '\0'), use vscnprintf(). If the 1825 * return is greater than or equal to @size, the resulting 1826 * string is truncated. 1827 */ 1828 int bstr_printf(char *buf, size_t size, const char *fmt, const u32 *bin_buf) 1829 { 1830 struct printf_spec spec = {0}; 1831 char *str, *end; 1832 const char *args = (const char *)bin_buf; 1833 1834 if (WARN_ON_ONCE((int) size < 0)) 1835 return 0; 1836 1837 str = buf; 1838 end = buf + size; 1839 1840 #define get_arg(type) \ 1841 ({ \ 1842 typeof(type) value; \ 1843 if (sizeof(type) == 8) { \ 1844 args = PTR_ALIGN(args, sizeof(u32)); \ 1845 *(u32 *)&value = *(u32 *)args; \ 1846 *((u32 *)&value + 1) = *(u32 *)(args + 4); \ 1847 } else { \ 1848 args = PTR_ALIGN(args, sizeof(type)); \ 1849 value = *(typeof(type) *)args; \ 1850 } \ 1851 args += sizeof(type); \ 1852 value; \ 1853 }) 1854 1855 /* Make sure end is always >= buf */ 1856 if (end < buf) { 1857 end = ((void *)-1); 1858 size = end - buf; 1859 } 1860 1861 while (*fmt) { 1862 const char *old_fmt = fmt; 1863 int read = format_decode(fmt, &spec); 1864 1865 fmt += read; 1866 1867 switch (spec.type) { 1868 case FORMAT_TYPE_NONE: { 1869 int copy = read; 1870 if (str < end) { 1871 if (copy > end - str) 1872 copy = end - str; 1873 memcpy(str, old_fmt, copy); 1874 } 1875 str += read; 1876 break; 1877 } 1878 1879 case FORMAT_TYPE_WIDTH: 1880 spec.field_width = get_arg(int); 1881 break; 1882 1883 case FORMAT_TYPE_PRECISION: 1884 spec.precision = get_arg(int); 1885 break; 1886 1887 case FORMAT_TYPE_CHAR: { 1888 char c; 1889 1890 if (!(spec.flags & LEFT)) { 1891 while (--spec.field_width > 0) { 1892 if (str < end) 1893 *str = ' '; 1894 ++str; 1895 } 1896 } 1897 c = (unsigned char) get_arg(char); 1898 if (str < end) 1899 *str = c; 1900 ++str; 1901 while (--spec.field_width > 0) { 1902 if (str < end) 1903 *str = ' '; 1904 ++str; 1905 } 1906 break; 1907 } 1908 1909 case FORMAT_TYPE_STR: { 1910 const char *str_arg = args; 1911 args += strlen(str_arg) + 1; 1912 str = string(str, end, (char *)str_arg, spec); 1913 break; 1914 } 1915 1916 case FORMAT_TYPE_PTR: 1917 str = pointer(fmt+1, str, end, get_arg(void *), spec); 1918 while (isalnum(*fmt)) 1919 fmt++; 1920 break; 1921 1922 case FORMAT_TYPE_PERCENT_CHAR: 1923 case FORMAT_TYPE_INVALID: 1924 if (str < end) 1925 *str = '%'; 1926 ++str; 1927 break; 1928 1929 case FORMAT_TYPE_NRCHARS: 1930 /* skip */ 1931 break; 1932 1933 default: { 1934 unsigned long long num; 1935 1936 switch (spec.type) { 1937 1938 case FORMAT_TYPE_LONG_LONG: 1939 num = get_arg(long long); 1940 break; 1941 case FORMAT_TYPE_ULONG: 1942 case FORMAT_TYPE_LONG: 1943 num = get_arg(unsigned long); 1944 break; 1945 case FORMAT_TYPE_SIZE_T: 1946 num = get_arg(size_t); 1947 break; 1948 case FORMAT_TYPE_PTRDIFF: 1949 num = get_arg(ptrdiff_t); 1950 break; 1951 case FORMAT_TYPE_UBYTE: 1952 num = get_arg(unsigned char); 1953 break; 1954 case FORMAT_TYPE_BYTE: 1955 num = get_arg(signed char); 1956 break; 1957 case FORMAT_TYPE_USHORT: 1958 num = get_arg(unsigned short); 1959 break; 1960 case FORMAT_TYPE_SHORT: 1961 num = get_arg(short); 1962 break; 1963 case FORMAT_TYPE_UINT: 1964 num = get_arg(unsigned int); 1965 break; 1966 default: 1967 num = get_arg(int); 1968 } 1969 1970 str = number(str, end, num, spec); 1971 } /* default: */ 1972 } /* switch(spec.type) */ 1973 } /* while(*fmt) */ 1974 1975 if (size > 0) { 1976 if (str < end) 1977 *str = '\0'; 1978 else 1979 end[-1] = '\0'; 1980 } 1981 1982 #undef get_arg 1983 1984 /* the trailing null byte doesn't count towards the total */ 1985 return str - buf; 1986 } 1987 EXPORT_SYMBOL_GPL(bstr_printf); 1988 1989 /** 1990 * bprintf - Parse a format string and place args' binary value in a buffer 1991 * @bin_buf: The buffer to place args' binary value 1992 * @size: The size of the buffer(by words(32bits), not characters) 1993 * @fmt: The format string to use 1994 * @...: Arguments for the format string 1995 * 1996 * The function returns the number of words(u32) written 1997 * into @bin_buf. 1998 */ 1999 int bprintf(u32 *bin_buf, size_t size, const char *fmt, ...) 2000 { 2001 va_list args; 2002 int ret; 2003 2004 va_start(args, fmt); 2005 ret = vbin_printf(bin_buf, size, fmt, args); 2006 va_end(args); 2007 2008 return ret; 2009 } 2010 EXPORT_SYMBOL_GPL(bprintf); 2011 2012 #endif /* CONFIG_BINARY_PRINTF */ 2013 2014 /** 2015 * vsscanf - Unformat a buffer into a list of arguments 2016 * @buf: input buffer 2017 * @fmt: format of buffer 2018 * @args: arguments 2019 */ 2020 int vsscanf(const char *buf, const char *fmt, va_list args) 2021 { 2022 const char *str = buf; 2023 char *next; 2024 char digit; 2025 int num = 0; 2026 u8 qualifier; 2027 unsigned int base; 2028 union { 2029 long long s; 2030 unsigned long long u; 2031 } val; 2032 s16 field_width; 2033 bool is_sign; 2034 2035 while (*fmt) { 2036 /* skip any white space in format */ 2037 /* white space in format matchs any amount of 2038 * white space, including none, in the input. 2039 */ 2040 if (isspace(*fmt)) { 2041 fmt = skip_spaces(++fmt); 2042 str = skip_spaces(str); 2043 } 2044 2045 /* anything that is not a conversion must match exactly */ 2046 if (*fmt != '%' && *fmt) { 2047 if (*fmt++ != *str++) 2048 break; 2049 continue; 2050 } 2051 2052 if (!*fmt) 2053 break; 2054 ++fmt; 2055 2056 /* skip this conversion. 2057 * advance both strings to next white space 2058 */ 2059 if (*fmt == '*') { 2060 if (!*str) 2061 break; 2062 while (!isspace(*fmt) && *fmt != '%' && *fmt) 2063 fmt++; 2064 while (!isspace(*str) && *str) 2065 str++; 2066 continue; 2067 } 2068 2069 /* get field width */ 2070 field_width = -1; 2071 if (isdigit(*fmt)) { 2072 field_width = skip_atoi(&fmt); 2073 if (field_width <= 0) 2074 break; 2075 } 2076 2077 /* get conversion qualifier */ 2078 qualifier = -1; 2079 if (*fmt == 'h' || _tolower(*fmt) == 'l' || 2080 _tolower(*fmt) == 'z') { 2081 qualifier = *fmt++; 2082 if (unlikely(qualifier == *fmt)) { 2083 if (qualifier == 'h') { 2084 qualifier = 'H'; 2085 fmt++; 2086 } else if (qualifier == 'l') { 2087 qualifier = 'L'; 2088 fmt++; 2089 } 2090 } 2091 } 2092 2093 if (!*fmt) 2094 break; 2095 2096 if (*fmt == 'n') { 2097 /* return number of characters read so far */ 2098 *va_arg(args, int *) = str - buf; 2099 ++fmt; 2100 continue; 2101 } 2102 2103 if (!*str) 2104 break; 2105 2106 base = 10; 2107 is_sign = 0; 2108 2109 switch (*fmt++) { 2110 case 'c': 2111 { 2112 char *s = (char *)va_arg(args, char*); 2113 if (field_width == -1) 2114 field_width = 1; 2115 do { 2116 *s++ = *str++; 2117 } while (--field_width > 0 && *str); 2118 num++; 2119 } 2120 continue; 2121 case 's': 2122 { 2123 char *s = (char *)va_arg(args, char *); 2124 if (field_width == -1) 2125 field_width = SHRT_MAX; 2126 /* first, skip leading white space in buffer */ 2127 str = skip_spaces(str); 2128 2129 /* now copy until next white space */ 2130 while (*str && !isspace(*str) && field_width--) 2131 *s++ = *str++; 2132 *s = '\0'; 2133 num++; 2134 } 2135 continue; 2136 case 'o': 2137 base = 8; 2138 break; 2139 case 'x': 2140 case 'X': 2141 base = 16; 2142 break; 2143 case 'i': 2144 base = 0; 2145 case 'd': 2146 is_sign = 1; 2147 case 'u': 2148 break; 2149 case '%': 2150 /* looking for '%' in str */ 2151 if (*str++ != '%') 2152 return num; 2153 continue; 2154 default: 2155 /* invalid format; stop here */ 2156 return num; 2157 } 2158 2159 /* have some sort of integer conversion. 2160 * first, skip white space in buffer. 2161 */ 2162 str = skip_spaces(str); 2163 2164 digit = *str; 2165 if (is_sign && digit == '-') 2166 digit = *(str + 1); 2167 2168 if (!digit 2169 || (base == 16 && !isxdigit(digit)) 2170 || (base == 10 && !isdigit(digit)) 2171 || (base == 8 && (!isdigit(digit) || digit > '7')) 2172 || (base == 0 && !isdigit(digit))) 2173 break; 2174 2175 if (is_sign) 2176 val.s = qualifier != 'L' ? 2177 simple_strtol(str, &next, base) : 2178 simple_strtoll(str, &next, base); 2179 else 2180 val.u = qualifier != 'L' ? 2181 simple_strtoul(str, &next, base) : 2182 simple_strtoull(str, &next, base); 2183 2184 if (field_width > 0 && next - str > field_width) { 2185 if (base == 0) 2186 _parse_integer_fixup_radix(str, &base); 2187 while (next - str > field_width) { 2188 if (is_sign) 2189 val.s = div_s64(val.s, base); 2190 else 2191 val.u = div_u64(val.u, base); 2192 --next; 2193 } 2194 } 2195 2196 switch (qualifier) { 2197 case 'H': /* that's 'hh' in format */ 2198 if (is_sign) 2199 *va_arg(args, signed char *) = val.s; 2200 else 2201 *va_arg(args, unsigned char *) = val.u; 2202 break; 2203 case 'h': 2204 if (is_sign) 2205 *va_arg(args, short *) = val.s; 2206 else 2207 *va_arg(args, unsigned short *) = val.u; 2208 break; 2209 case 'l': 2210 if (is_sign) 2211 *va_arg(args, long *) = val.s; 2212 else 2213 *va_arg(args, unsigned long *) = val.u; 2214 break; 2215 case 'L': 2216 if (is_sign) 2217 *va_arg(args, long long *) = val.s; 2218 else 2219 *va_arg(args, unsigned long long *) = val.u; 2220 break; 2221 case 'Z': 2222 case 'z': 2223 *va_arg(args, size_t *) = val.u; 2224 break; 2225 default: 2226 if (is_sign) 2227 *va_arg(args, int *) = val.s; 2228 else 2229 *va_arg(args, unsigned int *) = val.u; 2230 break; 2231 } 2232 num++; 2233 2234 if (!next) 2235 break; 2236 str = next; 2237 } 2238 2239 return num; 2240 } 2241 EXPORT_SYMBOL(vsscanf); 2242 2243 /** 2244 * sscanf - Unformat a buffer into a list of arguments 2245 * @buf: input buffer 2246 * @fmt: formatting of buffer 2247 * @...: resulting arguments 2248 */ 2249 int sscanf(const char *buf, const char *fmt, ...) 2250 { 2251 va_list args; 2252 int i; 2253 2254 va_start(args, fmt); 2255 i = vsscanf(buf, fmt, args); 2256 va_end(args); 2257 2258 return i; 2259 } 2260 EXPORT_SYMBOL(sscanf); 2261