1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * linux/lib/vsprintf.c 4 * 5 * Copyright (C) 1991, 1992 Linus Torvalds 6 */ 7 8 /* vsprintf.c -- Lars Wirzenius & Linus Torvalds. */ 9 /* 10 * Wirzenius wrote this portably, Torvalds fucked it up :-) 11 */ 12 13 /* 14 * Fri Jul 13 2001 Crutcher Dunnavant <crutcher+kernel@datastacks.com> 15 * - changed to provide snprintf and vsnprintf functions 16 * So Feb 1 16:51:32 CET 2004 Juergen Quade <quade@hsnr.de> 17 * - scnprintf and vscnprintf 18 */ 19 20 #include <linux/stdarg.h> 21 #include <linux/build_bug.h> 22 #include <linux/clk.h> 23 #include <linux/clk-provider.h> 24 #include <linux/errname.h> 25 #include <linux/module.h> /* for KSYM_SYMBOL_LEN */ 26 #include <linux/types.h> 27 #include <linux/string.h> 28 #include <linux/ctype.h> 29 #include <linux/kernel.h> 30 #include <linux/kallsyms.h> 31 #include <linux/math64.h> 32 #include <linux/uaccess.h> 33 #include <linux/ioport.h> 34 #include <linux/dcache.h> 35 #include <linux/cred.h> 36 #include <linux/rtc.h> 37 #include <linux/time.h> 38 #include <linux/uuid.h> 39 #include <linux/of.h> 40 #include <net/addrconf.h> 41 #include <linux/siphash.h> 42 #include <linux/compiler.h> 43 #include <linux/property.h> 44 #ifdef CONFIG_BLOCK 45 #include <linux/blkdev.h> 46 #endif 47 48 #include "../mm/internal.h" /* For the trace_print_flags arrays */ 49 50 #include <asm/page.h> /* for PAGE_SIZE */ 51 #include <asm/byteorder.h> /* cpu_to_le16 */ 52 #include <asm/unaligned.h> 53 54 #include <linux/string_helpers.h> 55 #include "kstrtox.h" 56 57 /* Disable pointer hashing if requested */ 58 bool no_hash_pointers __ro_after_init; 59 EXPORT_SYMBOL_GPL(no_hash_pointers); 60 61 static noinline unsigned long long simple_strntoull(const char *startp, size_t max_chars, char **endp, unsigned int base) 62 { 63 const char *cp; 64 unsigned long long result = 0ULL; 65 size_t prefix_chars; 66 unsigned int rv; 67 68 cp = _parse_integer_fixup_radix(startp, &base); 69 prefix_chars = cp - startp; 70 if (prefix_chars < max_chars) { 71 rv = _parse_integer_limit(cp, base, &result, max_chars - prefix_chars); 72 /* FIXME */ 73 cp += (rv & ~KSTRTOX_OVERFLOW); 74 } else { 75 /* Field too short for prefix + digit, skip over without converting */ 76 cp = startp + max_chars; 77 } 78 79 if (endp) 80 *endp = (char *)cp; 81 82 return result; 83 } 84 85 /** 86 * simple_strtoull - convert a string to an unsigned long long 87 * @cp: The start of the string 88 * @endp: A pointer to the end of the parsed string will be placed here 89 * @base: The number base to use 90 * 91 * This function has caveats. Please use kstrtoull instead. 92 */ 93 noinline 94 unsigned long long simple_strtoull(const char *cp, char **endp, unsigned int base) 95 { 96 return simple_strntoull(cp, INT_MAX, endp, base); 97 } 98 EXPORT_SYMBOL(simple_strtoull); 99 100 /** 101 * simple_strtoul - convert a string to an unsigned long 102 * @cp: The start of the string 103 * @endp: A pointer to the end of the parsed string will be placed here 104 * @base: The number base to use 105 * 106 * This function has caveats. Please use kstrtoul instead. 107 */ 108 unsigned long simple_strtoul(const char *cp, char **endp, unsigned int base) 109 { 110 return simple_strtoull(cp, endp, base); 111 } 112 EXPORT_SYMBOL(simple_strtoul); 113 114 /** 115 * simple_strtol - convert a string to a signed long 116 * @cp: The start of the string 117 * @endp: A pointer to the end of the parsed string will be placed here 118 * @base: The number base to use 119 * 120 * This function has caveats. Please use kstrtol instead. 121 */ 122 long simple_strtol(const char *cp, char **endp, unsigned int base) 123 { 124 if (*cp == '-') 125 return -simple_strtoul(cp + 1, endp, base); 126 127 return simple_strtoul(cp, endp, base); 128 } 129 EXPORT_SYMBOL(simple_strtol); 130 131 static long long simple_strntoll(const char *cp, size_t max_chars, char **endp, 132 unsigned int base) 133 { 134 /* 135 * simple_strntoull() safely handles receiving max_chars==0 in the 136 * case cp[0] == '-' && max_chars == 1. 137 * If max_chars == 0 we can drop through and pass it to simple_strntoull() 138 * and the content of *cp is irrelevant. 139 */ 140 if (*cp == '-' && max_chars > 0) 141 return -simple_strntoull(cp + 1, max_chars - 1, endp, base); 142 143 return simple_strntoull(cp, max_chars, endp, base); 144 } 145 146 /** 147 * simple_strtoll - convert a string to a signed long long 148 * @cp: The start of the string 149 * @endp: A pointer to the end of the parsed string will be placed here 150 * @base: The number base to use 151 * 152 * This function has caveats. Please use kstrtoll instead. 153 */ 154 long long simple_strtoll(const char *cp, char **endp, unsigned int base) 155 { 156 return simple_strntoll(cp, INT_MAX, endp, base); 157 } 158 EXPORT_SYMBOL(simple_strtoll); 159 160 static noinline_for_stack 161 int skip_atoi(const char **s) 162 { 163 int i = 0; 164 165 do { 166 i = i*10 + *((*s)++) - '0'; 167 } while (isdigit(**s)); 168 169 return i; 170 } 171 172 /* 173 * Decimal conversion is by far the most typical, and is used for 174 * /proc and /sys data. This directly impacts e.g. top performance 175 * with many processes running. We optimize it for speed by emitting 176 * two characters at a time, using a 200 byte lookup table. This 177 * roughly halves the number of multiplications compared to computing 178 * the digits one at a time. Implementation strongly inspired by the 179 * previous version, which in turn used ideas described at 180 * <http://www.cs.uiowa.edu/~jones/bcd/divide.html> (with permission 181 * from the author, Douglas W. Jones). 182 * 183 * It turns out there is precisely one 26 bit fixed-point 184 * approximation a of 64/100 for which x/100 == (x * (u64)a) >> 32 185 * holds for all x in [0, 10^8-1], namely a = 0x28f5c29. The actual 186 * range happens to be somewhat larger (x <= 1073741898), but that's 187 * irrelevant for our purpose. 188 * 189 * For dividing a number in the range [10^4, 10^6-1] by 100, we still 190 * need a 32x32->64 bit multiply, so we simply use the same constant. 191 * 192 * For dividing a number in the range [100, 10^4-1] by 100, there are 193 * several options. The simplest is (x * 0x147b) >> 19, which is valid 194 * for all x <= 43698. 195 */ 196 197 static const u16 decpair[100] = { 198 #define _(x) (__force u16) cpu_to_le16(((x % 10) | ((x / 10) << 8)) + 0x3030) 199 _( 0), _( 1), _( 2), _( 3), _( 4), _( 5), _( 6), _( 7), _( 8), _( 9), 200 _(10), _(11), _(12), _(13), _(14), _(15), _(16), _(17), _(18), _(19), 201 _(20), _(21), _(22), _(23), _(24), _(25), _(26), _(27), _(28), _(29), 202 _(30), _(31), _(32), _(33), _(34), _(35), _(36), _(37), _(38), _(39), 203 _(40), _(41), _(42), _(43), _(44), _(45), _(46), _(47), _(48), _(49), 204 _(50), _(51), _(52), _(53), _(54), _(55), _(56), _(57), _(58), _(59), 205 _(60), _(61), _(62), _(63), _(64), _(65), _(66), _(67), _(68), _(69), 206 _(70), _(71), _(72), _(73), _(74), _(75), _(76), _(77), _(78), _(79), 207 _(80), _(81), _(82), _(83), _(84), _(85), _(86), _(87), _(88), _(89), 208 _(90), _(91), _(92), _(93), _(94), _(95), _(96), _(97), _(98), _(99), 209 #undef _ 210 }; 211 212 /* 213 * This will print a single '0' even if r == 0, since we would 214 * immediately jump to out_r where two 0s would be written but only 215 * one of them accounted for in buf. This is needed by ip4_string 216 * below. All other callers pass a non-zero value of r. 217 */ 218 static noinline_for_stack 219 char *put_dec_trunc8(char *buf, unsigned r) 220 { 221 unsigned q; 222 223 /* 1 <= r < 10^8 */ 224 if (r < 100) 225 goto out_r; 226 227 /* 100 <= r < 10^8 */ 228 q = (r * (u64)0x28f5c29) >> 32; 229 *((u16 *)buf) = decpair[r - 100*q]; 230 buf += 2; 231 232 /* 1 <= q < 10^6 */ 233 if (q < 100) 234 goto out_q; 235 236 /* 100 <= q < 10^6 */ 237 r = (q * (u64)0x28f5c29) >> 32; 238 *((u16 *)buf) = decpair[q - 100*r]; 239 buf += 2; 240 241 /* 1 <= r < 10^4 */ 242 if (r < 100) 243 goto out_r; 244 245 /* 100 <= r < 10^4 */ 246 q = (r * 0x147b) >> 19; 247 *((u16 *)buf) = decpair[r - 100*q]; 248 buf += 2; 249 out_q: 250 /* 1 <= q < 100 */ 251 r = q; 252 out_r: 253 /* 1 <= r < 100 */ 254 *((u16 *)buf) = decpair[r]; 255 buf += r < 10 ? 1 : 2; 256 return buf; 257 } 258 259 #if BITS_PER_LONG == 64 && BITS_PER_LONG_LONG == 64 260 static noinline_for_stack 261 char *put_dec_full8(char *buf, unsigned r) 262 { 263 unsigned q; 264 265 /* 0 <= r < 10^8 */ 266 q = (r * (u64)0x28f5c29) >> 32; 267 *((u16 *)buf) = decpair[r - 100*q]; 268 buf += 2; 269 270 /* 0 <= q < 10^6 */ 271 r = (q * (u64)0x28f5c29) >> 32; 272 *((u16 *)buf) = decpair[q - 100*r]; 273 buf += 2; 274 275 /* 0 <= r < 10^4 */ 276 q = (r * 0x147b) >> 19; 277 *((u16 *)buf) = decpair[r - 100*q]; 278 buf += 2; 279 280 /* 0 <= q < 100 */ 281 *((u16 *)buf) = decpair[q]; 282 buf += 2; 283 return buf; 284 } 285 286 static noinline_for_stack 287 char *put_dec(char *buf, unsigned long long n) 288 { 289 if (n >= 100*1000*1000) 290 buf = put_dec_full8(buf, do_div(n, 100*1000*1000)); 291 /* 1 <= n <= 1.6e11 */ 292 if (n >= 100*1000*1000) 293 buf = put_dec_full8(buf, do_div(n, 100*1000*1000)); 294 /* 1 <= n < 1e8 */ 295 return put_dec_trunc8(buf, n); 296 } 297 298 #elif BITS_PER_LONG == 32 && BITS_PER_LONG_LONG == 64 299 300 static void 301 put_dec_full4(char *buf, unsigned r) 302 { 303 unsigned q; 304 305 /* 0 <= r < 10^4 */ 306 q = (r * 0x147b) >> 19; 307 *((u16 *)buf) = decpair[r - 100*q]; 308 buf += 2; 309 /* 0 <= q < 100 */ 310 *((u16 *)buf) = decpair[q]; 311 } 312 313 /* 314 * Call put_dec_full4 on x % 10000, return x / 10000. 315 * The approximation x/10000 == (x * 0x346DC5D7) >> 43 316 * holds for all x < 1,128,869,999. The largest value this 317 * helper will ever be asked to convert is 1,125,520,955. 318 * (second call in the put_dec code, assuming n is all-ones). 319 */ 320 static noinline_for_stack 321 unsigned put_dec_helper4(char *buf, unsigned x) 322 { 323 uint32_t q = (x * (uint64_t)0x346DC5D7) >> 43; 324 325 put_dec_full4(buf, x - q * 10000); 326 return q; 327 } 328 329 /* Based on code by Douglas W. Jones found at 330 * <http://www.cs.uiowa.edu/~jones/bcd/decimal.html#sixtyfour> 331 * (with permission from the author). 332 * Performs no 64-bit division and hence should be fast on 32-bit machines. 333 */ 334 static 335 char *put_dec(char *buf, unsigned long long n) 336 { 337 uint32_t d3, d2, d1, q, h; 338 339 if (n < 100*1000*1000) 340 return put_dec_trunc8(buf, n); 341 342 d1 = ((uint32_t)n >> 16); /* implicit "& 0xffff" */ 343 h = (n >> 32); 344 d2 = (h ) & 0xffff; 345 d3 = (h >> 16); /* implicit "& 0xffff" */ 346 347 /* n = 2^48 d3 + 2^32 d2 + 2^16 d1 + d0 348 = 281_4749_7671_0656 d3 + 42_9496_7296 d2 + 6_5536 d1 + d0 */ 349 q = 656 * d3 + 7296 * d2 + 5536 * d1 + ((uint32_t)n & 0xffff); 350 q = put_dec_helper4(buf, q); 351 352 q += 7671 * d3 + 9496 * d2 + 6 * d1; 353 q = put_dec_helper4(buf+4, q); 354 355 q += 4749 * d3 + 42 * d2; 356 q = put_dec_helper4(buf+8, q); 357 358 q += 281 * d3; 359 buf += 12; 360 if (q) 361 buf = put_dec_trunc8(buf, q); 362 else while (buf[-1] == '0') 363 --buf; 364 365 return buf; 366 } 367 368 #endif 369 370 /* 371 * Convert passed number to decimal string. 372 * Returns the length of string. On buffer overflow, returns 0. 373 * 374 * If speed is not important, use snprintf(). It's easy to read the code. 375 */ 376 int num_to_str(char *buf, int size, unsigned long long num, unsigned int width) 377 { 378 /* put_dec requires 2-byte alignment of the buffer. */ 379 char tmp[sizeof(num) * 3] __aligned(2); 380 int idx, len; 381 382 /* put_dec() may work incorrectly for num = 0 (generate "", not "0") */ 383 if (num <= 9) { 384 tmp[0] = '0' + num; 385 len = 1; 386 } else { 387 len = put_dec(tmp, num) - tmp; 388 } 389 390 if (len > size || width > size) 391 return 0; 392 393 if (width > len) { 394 width = width - len; 395 for (idx = 0; idx < width; idx++) 396 buf[idx] = ' '; 397 } else { 398 width = 0; 399 } 400 401 for (idx = 0; idx < len; ++idx) 402 buf[idx + width] = tmp[len - idx - 1]; 403 404 return len + width; 405 } 406 407 #define SIGN 1 /* unsigned/signed, must be 1 */ 408 #define LEFT 2 /* left justified */ 409 #define PLUS 4 /* show plus */ 410 #define SPACE 8 /* space if plus */ 411 #define ZEROPAD 16 /* pad with zero, must be 16 == '0' - ' ' */ 412 #define SMALL 32 /* use lowercase in hex (must be 32 == 0x20) */ 413 #define SPECIAL 64 /* prefix hex with "0x", octal with "0" */ 414 415 static_assert(SIGN == 1); 416 static_assert(ZEROPAD == ('0' - ' ')); 417 static_assert(SMALL == ('a' ^ 'A')); 418 419 enum format_type { 420 FORMAT_TYPE_NONE, /* Just a string part */ 421 FORMAT_TYPE_WIDTH, 422 FORMAT_TYPE_PRECISION, 423 FORMAT_TYPE_CHAR, 424 FORMAT_TYPE_STR, 425 FORMAT_TYPE_PTR, 426 FORMAT_TYPE_PERCENT_CHAR, 427 FORMAT_TYPE_INVALID, 428 FORMAT_TYPE_LONG_LONG, 429 FORMAT_TYPE_ULONG, 430 FORMAT_TYPE_LONG, 431 FORMAT_TYPE_UBYTE, 432 FORMAT_TYPE_BYTE, 433 FORMAT_TYPE_USHORT, 434 FORMAT_TYPE_SHORT, 435 FORMAT_TYPE_UINT, 436 FORMAT_TYPE_INT, 437 FORMAT_TYPE_SIZE_T, 438 FORMAT_TYPE_PTRDIFF 439 }; 440 441 struct printf_spec { 442 unsigned int type:8; /* format_type enum */ 443 signed int field_width:24; /* width of output field */ 444 unsigned int flags:8; /* flags to number() */ 445 unsigned int base:8; /* number base, 8, 10 or 16 only */ 446 signed int precision:16; /* # of digits/chars */ 447 } __packed; 448 static_assert(sizeof(struct printf_spec) == 8); 449 450 #define FIELD_WIDTH_MAX ((1 << 23) - 1) 451 #define PRECISION_MAX ((1 << 15) - 1) 452 453 static noinline_for_stack 454 char *number(char *buf, char *end, unsigned long long num, 455 struct printf_spec spec) 456 { 457 /* put_dec requires 2-byte alignment of the buffer. */ 458 char tmp[3 * sizeof(num)] __aligned(2); 459 char sign; 460 char locase; 461 int need_pfx = ((spec.flags & SPECIAL) && spec.base != 10); 462 int i; 463 bool is_zero = num == 0LL; 464 int field_width = spec.field_width; 465 int precision = spec.precision; 466 467 /* locase = 0 or 0x20. ORing digits or letters with 'locase' 468 * produces same digits or (maybe lowercased) letters */ 469 locase = (spec.flags & SMALL); 470 if (spec.flags & LEFT) 471 spec.flags &= ~ZEROPAD; 472 sign = 0; 473 if (spec.flags & SIGN) { 474 if ((signed long long)num < 0) { 475 sign = '-'; 476 num = -(signed long long)num; 477 field_width--; 478 } else if (spec.flags & PLUS) { 479 sign = '+'; 480 field_width--; 481 } else if (spec.flags & SPACE) { 482 sign = ' '; 483 field_width--; 484 } 485 } 486 if (need_pfx) { 487 if (spec.base == 16) 488 field_width -= 2; 489 else if (!is_zero) 490 field_width--; 491 } 492 493 /* generate full string in tmp[], in reverse order */ 494 i = 0; 495 if (num < spec.base) 496 tmp[i++] = hex_asc_upper[num] | locase; 497 else if (spec.base != 10) { /* 8 or 16 */ 498 int mask = spec.base - 1; 499 int shift = 3; 500 501 if (spec.base == 16) 502 shift = 4; 503 do { 504 tmp[i++] = (hex_asc_upper[((unsigned char)num) & mask] | locase); 505 num >>= shift; 506 } while (num); 507 } else { /* base 10 */ 508 i = put_dec(tmp, num) - tmp; 509 } 510 511 /* printing 100 using %2d gives "100", not "00" */ 512 if (i > precision) 513 precision = i; 514 /* leading space padding */ 515 field_width -= precision; 516 if (!(spec.flags & (ZEROPAD | LEFT))) { 517 while (--field_width >= 0) { 518 if (buf < end) 519 *buf = ' '; 520 ++buf; 521 } 522 } 523 /* sign */ 524 if (sign) { 525 if (buf < end) 526 *buf = sign; 527 ++buf; 528 } 529 /* "0x" / "0" prefix */ 530 if (need_pfx) { 531 if (spec.base == 16 || !is_zero) { 532 if (buf < end) 533 *buf = '0'; 534 ++buf; 535 } 536 if (spec.base == 16) { 537 if (buf < end) 538 *buf = ('X' | locase); 539 ++buf; 540 } 541 } 542 /* zero or space padding */ 543 if (!(spec.flags & LEFT)) { 544 char c = ' ' + (spec.flags & ZEROPAD); 545 546 while (--field_width >= 0) { 547 if (buf < end) 548 *buf = c; 549 ++buf; 550 } 551 } 552 /* hmm even more zero padding? */ 553 while (i <= --precision) { 554 if (buf < end) 555 *buf = '0'; 556 ++buf; 557 } 558 /* actual digits of result */ 559 while (--i >= 0) { 560 if (buf < end) 561 *buf = tmp[i]; 562 ++buf; 563 } 564 /* trailing space padding */ 565 while (--field_width >= 0) { 566 if (buf < end) 567 *buf = ' '; 568 ++buf; 569 } 570 571 return buf; 572 } 573 574 static noinline_for_stack 575 char *special_hex_number(char *buf, char *end, unsigned long long num, int size) 576 { 577 struct printf_spec spec; 578 579 spec.type = FORMAT_TYPE_PTR; 580 spec.field_width = 2 + 2 * size; /* 0x + hex */ 581 spec.flags = SPECIAL | SMALL | ZEROPAD; 582 spec.base = 16; 583 spec.precision = -1; 584 585 return number(buf, end, num, spec); 586 } 587 588 static void move_right(char *buf, char *end, unsigned len, unsigned spaces) 589 { 590 size_t size; 591 if (buf >= end) /* nowhere to put anything */ 592 return; 593 size = end - buf; 594 if (size <= spaces) { 595 memset(buf, ' ', size); 596 return; 597 } 598 if (len) { 599 if (len > size - spaces) 600 len = size - spaces; 601 memmove(buf + spaces, buf, len); 602 } 603 memset(buf, ' ', spaces); 604 } 605 606 /* 607 * Handle field width padding for a string. 608 * @buf: current buffer position 609 * @n: length of string 610 * @end: end of output buffer 611 * @spec: for field width and flags 612 * Returns: new buffer position after padding. 613 */ 614 static noinline_for_stack 615 char *widen_string(char *buf, int n, char *end, struct printf_spec spec) 616 { 617 unsigned spaces; 618 619 if (likely(n >= spec.field_width)) 620 return buf; 621 /* we want to pad the sucker */ 622 spaces = spec.field_width - n; 623 if (!(spec.flags & LEFT)) { 624 move_right(buf - n, end, n, spaces); 625 return buf + spaces; 626 } 627 while (spaces--) { 628 if (buf < end) 629 *buf = ' '; 630 ++buf; 631 } 632 return buf; 633 } 634 635 /* Handle string from a well known address. */ 636 static char *string_nocheck(char *buf, char *end, const char *s, 637 struct printf_spec spec) 638 { 639 int len = 0; 640 int lim = spec.precision; 641 642 while (lim--) { 643 char c = *s++; 644 if (!c) 645 break; 646 if (buf < end) 647 *buf = c; 648 ++buf; 649 ++len; 650 } 651 return widen_string(buf, len, end, spec); 652 } 653 654 static char *err_ptr(char *buf, char *end, void *ptr, 655 struct printf_spec spec) 656 { 657 int err = PTR_ERR(ptr); 658 const char *sym = errname(err); 659 660 if (sym) 661 return string_nocheck(buf, end, sym, spec); 662 663 /* 664 * Somebody passed ERR_PTR(-1234) or some other non-existing 665 * Efoo - or perhaps CONFIG_SYMBOLIC_ERRNAME=n. Fall back to 666 * printing it as its decimal representation. 667 */ 668 spec.flags |= SIGN; 669 spec.base = 10; 670 return number(buf, end, err, spec); 671 } 672 673 /* Be careful: error messages must fit into the given buffer. */ 674 static char *error_string(char *buf, char *end, const char *s, 675 struct printf_spec spec) 676 { 677 /* 678 * Hard limit to avoid a completely insane messages. It actually 679 * works pretty well because most error messages are in 680 * the many pointer format modifiers. 681 */ 682 if (spec.precision == -1) 683 spec.precision = 2 * sizeof(void *); 684 685 return string_nocheck(buf, end, s, spec); 686 } 687 688 /* 689 * Do not call any complex external code here. Nested printk()/vsprintf() 690 * might cause infinite loops. Failures might break printk() and would 691 * be hard to debug. 692 */ 693 static const char *check_pointer_msg(const void *ptr) 694 { 695 if (!ptr) 696 return "(null)"; 697 698 if ((unsigned long)ptr < PAGE_SIZE || IS_ERR_VALUE(ptr)) 699 return "(efault)"; 700 701 return NULL; 702 } 703 704 static int check_pointer(char **buf, char *end, const void *ptr, 705 struct printf_spec spec) 706 { 707 const char *err_msg; 708 709 err_msg = check_pointer_msg(ptr); 710 if (err_msg) { 711 *buf = error_string(*buf, end, err_msg, spec); 712 return -EFAULT; 713 } 714 715 return 0; 716 } 717 718 static noinline_for_stack 719 char *string(char *buf, char *end, const char *s, 720 struct printf_spec spec) 721 { 722 if (check_pointer(&buf, end, s, spec)) 723 return buf; 724 725 return string_nocheck(buf, end, s, spec); 726 } 727 728 static char *pointer_string(char *buf, char *end, 729 const void *ptr, 730 struct printf_spec spec) 731 { 732 spec.base = 16; 733 spec.flags |= SMALL; 734 if (spec.field_width == -1) { 735 spec.field_width = 2 * sizeof(ptr); 736 spec.flags |= ZEROPAD; 737 } 738 739 return number(buf, end, (unsigned long int)ptr, spec); 740 } 741 742 /* Make pointers available for printing early in the boot sequence. */ 743 static int debug_boot_weak_hash __ro_after_init; 744 745 static int __init debug_boot_weak_hash_enable(char *str) 746 { 747 debug_boot_weak_hash = 1; 748 pr_info("debug_boot_weak_hash enabled\n"); 749 return 0; 750 } 751 early_param("debug_boot_weak_hash", debug_boot_weak_hash_enable); 752 753 static DEFINE_STATIC_KEY_FALSE(filled_random_ptr_key); 754 755 static void enable_ptr_key_workfn(struct work_struct *work) 756 { 757 static_branch_enable(&filled_random_ptr_key); 758 } 759 760 /* Maps a pointer to a 32 bit unique identifier. */ 761 static inline int __ptr_to_hashval(const void *ptr, unsigned long *hashval_out) 762 { 763 static siphash_key_t ptr_key __read_mostly; 764 unsigned long hashval; 765 766 if (!static_branch_likely(&filled_random_ptr_key)) { 767 static bool filled = false; 768 static DEFINE_SPINLOCK(filling); 769 static DECLARE_WORK(enable_ptr_key_work, enable_ptr_key_workfn); 770 unsigned long flags; 771 772 if (!system_unbound_wq || !rng_is_initialized() || 773 !spin_trylock_irqsave(&filling, flags)) 774 return -EAGAIN; 775 776 if (!filled) { 777 get_random_bytes(&ptr_key, sizeof(ptr_key)); 778 queue_work(system_unbound_wq, &enable_ptr_key_work); 779 filled = true; 780 } 781 spin_unlock_irqrestore(&filling, flags); 782 } 783 784 785 #ifdef CONFIG_64BIT 786 hashval = (unsigned long)siphash_1u64((u64)ptr, &ptr_key); 787 /* 788 * Mask off the first 32 bits, this makes explicit that we have 789 * modified the address (and 32 bits is plenty for a unique ID). 790 */ 791 hashval = hashval & 0xffffffff; 792 #else 793 hashval = (unsigned long)siphash_1u32((u32)ptr, &ptr_key); 794 #endif 795 *hashval_out = hashval; 796 return 0; 797 } 798 799 int ptr_to_hashval(const void *ptr, unsigned long *hashval_out) 800 { 801 return __ptr_to_hashval(ptr, hashval_out); 802 } 803 804 static char *ptr_to_id(char *buf, char *end, const void *ptr, 805 struct printf_spec spec) 806 { 807 const char *str = sizeof(ptr) == 8 ? "(____ptrval____)" : "(ptrval)"; 808 unsigned long hashval; 809 int ret; 810 811 /* 812 * Print the real pointer value for NULL and error pointers, 813 * as they are not actual addresses. 814 */ 815 if (IS_ERR_OR_NULL(ptr)) 816 return pointer_string(buf, end, ptr, spec); 817 818 /* When debugging early boot use non-cryptographically secure hash. */ 819 if (unlikely(debug_boot_weak_hash)) { 820 hashval = hash_long((unsigned long)ptr, 32); 821 return pointer_string(buf, end, (const void *)hashval, spec); 822 } 823 824 ret = __ptr_to_hashval(ptr, &hashval); 825 if (ret) { 826 spec.field_width = 2 * sizeof(ptr); 827 /* string length must be less than default_width */ 828 return error_string(buf, end, str, spec); 829 } 830 831 return pointer_string(buf, end, (const void *)hashval, spec); 832 } 833 834 static char *default_pointer(char *buf, char *end, const void *ptr, 835 struct printf_spec spec) 836 { 837 /* 838 * default is to _not_ leak addresses, so hash before printing, 839 * unless no_hash_pointers is specified on the command line. 840 */ 841 if (unlikely(no_hash_pointers)) 842 return pointer_string(buf, end, ptr, spec); 843 844 return ptr_to_id(buf, end, ptr, spec); 845 } 846 847 int kptr_restrict __read_mostly; 848 849 static noinline_for_stack 850 char *restricted_pointer(char *buf, char *end, const void *ptr, 851 struct printf_spec spec) 852 { 853 switch (kptr_restrict) { 854 case 0: 855 /* Handle as %p, hash and do _not_ leak addresses. */ 856 return default_pointer(buf, end, ptr, spec); 857 case 1: { 858 const struct cred *cred; 859 860 /* 861 * kptr_restrict==1 cannot be used in IRQ context 862 * because its test for CAP_SYSLOG would be meaningless. 863 */ 864 if (in_irq() || in_serving_softirq() || in_nmi()) { 865 if (spec.field_width == -1) 866 spec.field_width = 2 * sizeof(ptr); 867 return error_string(buf, end, "pK-error", spec); 868 } 869 870 /* 871 * Only print the real pointer value if the current 872 * process has CAP_SYSLOG and is running with the 873 * same credentials it started with. This is because 874 * access to files is checked at open() time, but %pK 875 * checks permission at read() time. We don't want to 876 * leak pointer values if a binary opens a file using 877 * %pK and then elevates privileges before reading it. 878 */ 879 cred = current_cred(); 880 if (!has_capability_noaudit(current, CAP_SYSLOG) || 881 !uid_eq(cred->euid, cred->uid) || 882 !gid_eq(cred->egid, cred->gid)) 883 ptr = NULL; 884 break; 885 } 886 case 2: 887 default: 888 /* Always print 0's for %pK */ 889 ptr = NULL; 890 break; 891 } 892 893 return pointer_string(buf, end, ptr, spec); 894 } 895 896 static noinline_for_stack 897 char *dentry_name(char *buf, char *end, const struct dentry *d, struct printf_spec spec, 898 const char *fmt) 899 { 900 const char *array[4], *s; 901 const struct dentry *p; 902 int depth; 903 int i, n; 904 905 switch (fmt[1]) { 906 case '2': case '3': case '4': 907 depth = fmt[1] - '0'; 908 break; 909 default: 910 depth = 1; 911 } 912 913 rcu_read_lock(); 914 for (i = 0; i < depth; i++, d = p) { 915 if (check_pointer(&buf, end, d, spec)) { 916 rcu_read_unlock(); 917 return buf; 918 } 919 920 p = READ_ONCE(d->d_parent); 921 array[i] = READ_ONCE(d->d_name.name); 922 if (p == d) { 923 if (i) 924 array[i] = ""; 925 i++; 926 break; 927 } 928 } 929 s = array[--i]; 930 for (n = 0; n != spec.precision; n++, buf++) { 931 char c = *s++; 932 if (!c) { 933 if (!i) 934 break; 935 c = '/'; 936 s = array[--i]; 937 } 938 if (buf < end) 939 *buf = c; 940 } 941 rcu_read_unlock(); 942 return widen_string(buf, n, end, spec); 943 } 944 945 static noinline_for_stack 946 char *file_dentry_name(char *buf, char *end, const struct file *f, 947 struct printf_spec spec, const char *fmt) 948 { 949 if (check_pointer(&buf, end, f, spec)) 950 return buf; 951 952 return dentry_name(buf, end, f->f_path.dentry, spec, fmt); 953 } 954 #ifdef CONFIG_BLOCK 955 static noinline_for_stack 956 char *bdev_name(char *buf, char *end, struct block_device *bdev, 957 struct printf_spec spec, const char *fmt) 958 { 959 struct gendisk *hd; 960 961 if (check_pointer(&buf, end, bdev, spec)) 962 return buf; 963 964 hd = bdev->bd_disk; 965 buf = string(buf, end, hd->disk_name, spec); 966 if (bdev->bd_partno) { 967 if (isdigit(hd->disk_name[strlen(hd->disk_name)-1])) { 968 if (buf < end) 969 *buf = 'p'; 970 buf++; 971 } 972 buf = number(buf, end, bdev->bd_partno, spec); 973 } 974 return buf; 975 } 976 #endif 977 978 static noinline_for_stack 979 char *symbol_string(char *buf, char *end, void *ptr, 980 struct printf_spec spec, const char *fmt) 981 { 982 unsigned long value; 983 #ifdef CONFIG_KALLSYMS 984 char sym[KSYM_SYMBOL_LEN]; 985 #endif 986 987 if (fmt[1] == 'R') 988 ptr = __builtin_extract_return_addr(ptr); 989 value = (unsigned long)ptr; 990 991 #ifdef CONFIG_KALLSYMS 992 if (*fmt == 'B' && fmt[1] == 'b') 993 sprint_backtrace_build_id(sym, value); 994 else if (*fmt == 'B') 995 sprint_backtrace(sym, value); 996 else if (*fmt == 'S' && (fmt[1] == 'b' || (fmt[1] == 'R' && fmt[2] == 'b'))) 997 sprint_symbol_build_id(sym, value); 998 else if (*fmt != 's') 999 sprint_symbol(sym, value); 1000 else 1001 sprint_symbol_no_offset(sym, value); 1002 1003 return string_nocheck(buf, end, sym, spec); 1004 #else 1005 return special_hex_number(buf, end, value, sizeof(void *)); 1006 #endif 1007 } 1008 1009 static const struct printf_spec default_str_spec = { 1010 .field_width = -1, 1011 .precision = -1, 1012 }; 1013 1014 static const struct printf_spec default_flag_spec = { 1015 .base = 16, 1016 .precision = -1, 1017 .flags = SPECIAL | SMALL, 1018 }; 1019 1020 static const struct printf_spec default_dec_spec = { 1021 .base = 10, 1022 .precision = -1, 1023 }; 1024 1025 static const struct printf_spec default_dec02_spec = { 1026 .base = 10, 1027 .field_width = 2, 1028 .precision = -1, 1029 .flags = ZEROPAD, 1030 }; 1031 1032 static const struct printf_spec default_dec04_spec = { 1033 .base = 10, 1034 .field_width = 4, 1035 .precision = -1, 1036 .flags = ZEROPAD, 1037 }; 1038 1039 static noinline_for_stack 1040 char *resource_string(char *buf, char *end, struct resource *res, 1041 struct printf_spec spec, const char *fmt) 1042 { 1043 #ifndef IO_RSRC_PRINTK_SIZE 1044 #define IO_RSRC_PRINTK_SIZE 6 1045 #endif 1046 1047 #ifndef MEM_RSRC_PRINTK_SIZE 1048 #define MEM_RSRC_PRINTK_SIZE 10 1049 #endif 1050 static const struct printf_spec io_spec = { 1051 .base = 16, 1052 .field_width = IO_RSRC_PRINTK_SIZE, 1053 .precision = -1, 1054 .flags = SPECIAL | SMALL | ZEROPAD, 1055 }; 1056 static const struct printf_spec mem_spec = { 1057 .base = 16, 1058 .field_width = MEM_RSRC_PRINTK_SIZE, 1059 .precision = -1, 1060 .flags = SPECIAL | SMALL | ZEROPAD, 1061 }; 1062 static const struct printf_spec bus_spec = { 1063 .base = 16, 1064 .field_width = 2, 1065 .precision = -1, 1066 .flags = SMALL | ZEROPAD, 1067 }; 1068 static const struct printf_spec str_spec = { 1069 .field_width = -1, 1070 .precision = 10, 1071 .flags = LEFT, 1072 }; 1073 1074 /* 32-bit res (sizeof==4): 10 chars in dec, 10 in hex ("0x" + 8) 1075 * 64-bit res (sizeof==8): 20 chars in dec, 18 in hex ("0x" + 16) */ 1076 #define RSRC_BUF_SIZE ((2 * sizeof(resource_size_t)) + 4) 1077 #define FLAG_BUF_SIZE (2 * sizeof(res->flags)) 1078 #define DECODED_BUF_SIZE sizeof("[mem - 64bit pref window disabled]") 1079 #define RAW_BUF_SIZE sizeof("[mem - flags 0x]") 1080 char sym[max(2*RSRC_BUF_SIZE + DECODED_BUF_SIZE, 1081 2*RSRC_BUF_SIZE + FLAG_BUF_SIZE + RAW_BUF_SIZE)]; 1082 1083 char *p = sym, *pend = sym + sizeof(sym); 1084 int decode = (fmt[0] == 'R') ? 1 : 0; 1085 const struct printf_spec *specp; 1086 1087 if (check_pointer(&buf, end, res, spec)) 1088 return buf; 1089 1090 *p++ = '['; 1091 if (res->flags & IORESOURCE_IO) { 1092 p = string_nocheck(p, pend, "io ", str_spec); 1093 specp = &io_spec; 1094 } else if (res->flags & IORESOURCE_MEM) { 1095 p = string_nocheck(p, pend, "mem ", str_spec); 1096 specp = &mem_spec; 1097 } else if (res->flags & IORESOURCE_IRQ) { 1098 p = string_nocheck(p, pend, "irq ", str_spec); 1099 specp = &default_dec_spec; 1100 } else if (res->flags & IORESOURCE_DMA) { 1101 p = string_nocheck(p, pend, "dma ", str_spec); 1102 specp = &default_dec_spec; 1103 } else if (res->flags & IORESOURCE_BUS) { 1104 p = string_nocheck(p, pend, "bus ", str_spec); 1105 specp = &bus_spec; 1106 } else { 1107 p = string_nocheck(p, pend, "??? ", str_spec); 1108 specp = &mem_spec; 1109 decode = 0; 1110 } 1111 if (decode && res->flags & IORESOURCE_UNSET) { 1112 p = string_nocheck(p, pend, "size ", str_spec); 1113 p = number(p, pend, resource_size(res), *specp); 1114 } else { 1115 p = number(p, pend, res->start, *specp); 1116 if (res->start != res->end) { 1117 *p++ = '-'; 1118 p = number(p, pend, res->end, *specp); 1119 } 1120 } 1121 if (decode) { 1122 if (res->flags & IORESOURCE_MEM_64) 1123 p = string_nocheck(p, pend, " 64bit", str_spec); 1124 if (res->flags & IORESOURCE_PREFETCH) 1125 p = string_nocheck(p, pend, " pref", str_spec); 1126 if (res->flags & IORESOURCE_WINDOW) 1127 p = string_nocheck(p, pend, " window", str_spec); 1128 if (res->flags & IORESOURCE_DISABLED) 1129 p = string_nocheck(p, pend, " disabled", str_spec); 1130 } else { 1131 p = string_nocheck(p, pend, " flags ", str_spec); 1132 p = number(p, pend, res->flags, default_flag_spec); 1133 } 1134 *p++ = ']'; 1135 *p = '\0'; 1136 1137 return string_nocheck(buf, end, sym, spec); 1138 } 1139 1140 static noinline_for_stack 1141 char *hex_string(char *buf, char *end, u8 *addr, struct printf_spec spec, 1142 const char *fmt) 1143 { 1144 int i, len = 1; /* if we pass '%ph[CDN]', field width remains 1145 negative value, fallback to the default */ 1146 char separator; 1147 1148 if (spec.field_width == 0) 1149 /* nothing to print */ 1150 return buf; 1151 1152 if (check_pointer(&buf, end, addr, spec)) 1153 return buf; 1154 1155 switch (fmt[1]) { 1156 case 'C': 1157 separator = ':'; 1158 break; 1159 case 'D': 1160 separator = '-'; 1161 break; 1162 case 'N': 1163 separator = 0; 1164 break; 1165 default: 1166 separator = ' '; 1167 break; 1168 } 1169 1170 if (spec.field_width > 0) 1171 len = min_t(int, spec.field_width, 64); 1172 1173 for (i = 0; i < len; ++i) { 1174 if (buf < end) 1175 *buf = hex_asc_hi(addr[i]); 1176 ++buf; 1177 if (buf < end) 1178 *buf = hex_asc_lo(addr[i]); 1179 ++buf; 1180 1181 if (separator && i != len - 1) { 1182 if (buf < end) 1183 *buf = separator; 1184 ++buf; 1185 } 1186 } 1187 1188 return buf; 1189 } 1190 1191 static noinline_for_stack 1192 char *bitmap_string(char *buf, char *end, unsigned long *bitmap, 1193 struct printf_spec spec, const char *fmt) 1194 { 1195 const int CHUNKSZ = 32; 1196 int nr_bits = max_t(int, spec.field_width, 0); 1197 int i, chunksz; 1198 bool first = true; 1199 1200 if (check_pointer(&buf, end, bitmap, spec)) 1201 return buf; 1202 1203 /* reused to print numbers */ 1204 spec = (struct printf_spec){ .flags = SMALL | ZEROPAD, .base = 16 }; 1205 1206 chunksz = nr_bits & (CHUNKSZ - 1); 1207 if (chunksz == 0) 1208 chunksz = CHUNKSZ; 1209 1210 i = ALIGN(nr_bits, CHUNKSZ) - CHUNKSZ; 1211 for (; i >= 0; i -= CHUNKSZ) { 1212 u32 chunkmask, val; 1213 int word, bit; 1214 1215 chunkmask = ((1ULL << chunksz) - 1); 1216 word = i / BITS_PER_LONG; 1217 bit = i % BITS_PER_LONG; 1218 val = (bitmap[word] >> bit) & chunkmask; 1219 1220 if (!first) { 1221 if (buf < end) 1222 *buf = ','; 1223 buf++; 1224 } 1225 first = false; 1226 1227 spec.field_width = DIV_ROUND_UP(chunksz, 4); 1228 buf = number(buf, end, val, spec); 1229 1230 chunksz = CHUNKSZ; 1231 } 1232 return buf; 1233 } 1234 1235 static noinline_for_stack 1236 char *bitmap_list_string(char *buf, char *end, unsigned long *bitmap, 1237 struct printf_spec spec, const char *fmt) 1238 { 1239 int nr_bits = max_t(int, spec.field_width, 0); 1240 bool first = true; 1241 int rbot, rtop; 1242 1243 if (check_pointer(&buf, end, bitmap, spec)) 1244 return buf; 1245 1246 for_each_set_bitrange(rbot, rtop, bitmap, nr_bits) { 1247 if (!first) { 1248 if (buf < end) 1249 *buf = ','; 1250 buf++; 1251 } 1252 first = false; 1253 1254 buf = number(buf, end, rbot, default_dec_spec); 1255 if (rtop == rbot + 1) 1256 continue; 1257 1258 if (buf < end) 1259 *buf = '-'; 1260 buf = number(++buf, end, rtop - 1, default_dec_spec); 1261 } 1262 return buf; 1263 } 1264 1265 static noinline_for_stack 1266 char *mac_address_string(char *buf, char *end, u8 *addr, 1267 struct printf_spec spec, const char *fmt) 1268 { 1269 char mac_addr[sizeof("xx:xx:xx:xx:xx:xx")]; 1270 char *p = mac_addr; 1271 int i; 1272 char separator; 1273 bool reversed = false; 1274 1275 if (check_pointer(&buf, end, addr, spec)) 1276 return buf; 1277 1278 switch (fmt[1]) { 1279 case 'F': 1280 separator = '-'; 1281 break; 1282 1283 case 'R': 1284 reversed = true; 1285 fallthrough; 1286 1287 default: 1288 separator = ':'; 1289 break; 1290 } 1291 1292 for (i = 0; i < 6; i++) { 1293 if (reversed) 1294 p = hex_byte_pack(p, addr[5 - i]); 1295 else 1296 p = hex_byte_pack(p, addr[i]); 1297 1298 if (fmt[0] == 'M' && i != 5) 1299 *p++ = separator; 1300 } 1301 *p = '\0'; 1302 1303 return string_nocheck(buf, end, mac_addr, spec); 1304 } 1305 1306 static noinline_for_stack 1307 char *ip4_string(char *p, const u8 *addr, const char *fmt) 1308 { 1309 int i; 1310 bool leading_zeros = (fmt[0] == 'i'); 1311 int index; 1312 int step; 1313 1314 switch (fmt[2]) { 1315 case 'h': 1316 #ifdef __BIG_ENDIAN 1317 index = 0; 1318 step = 1; 1319 #else 1320 index = 3; 1321 step = -1; 1322 #endif 1323 break; 1324 case 'l': 1325 index = 3; 1326 step = -1; 1327 break; 1328 case 'n': 1329 case 'b': 1330 default: 1331 index = 0; 1332 step = 1; 1333 break; 1334 } 1335 for (i = 0; i < 4; i++) { 1336 char temp[4] __aligned(2); /* hold each IP quad in reverse order */ 1337 int digits = put_dec_trunc8(temp, addr[index]) - temp; 1338 if (leading_zeros) { 1339 if (digits < 3) 1340 *p++ = '0'; 1341 if (digits < 2) 1342 *p++ = '0'; 1343 } 1344 /* reverse the digits in the quad */ 1345 while (digits--) 1346 *p++ = temp[digits]; 1347 if (i < 3) 1348 *p++ = '.'; 1349 index += step; 1350 } 1351 *p = '\0'; 1352 1353 return p; 1354 } 1355 1356 static noinline_for_stack 1357 char *ip6_compressed_string(char *p, const char *addr) 1358 { 1359 int i, j, range; 1360 unsigned char zerolength[8]; 1361 int longest = 1; 1362 int colonpos = -1; 1363 u16 word; 1364 u8 hi, lo; 1365 bool needcolon = false; 1366 bool useIPv4; 1367 struct in6_addr in6; 1368 1369 memcpy(&in6, addr, sizeof(struct in6_addr)); 1370 1371 useIPv4 = ipv6_addr_v4mapped(&in6) || ipv6_addr_is_isatap(&in6); 1372 1373 memset(zerolength, 0, sizeof(zerolength)); 1374 1375 if (useIPv4) 1376 range = 6; 1377 else 1378 range = 8; 1379 1380 /* find position of longest 0 run */ 1381 for (i = 0; i < range; i++) { 1382 for (j = i; j < range; j++) { 1383 if (in6.s6_addr16[j] != 0) 1384 break; 1385 zerolength[i]++; 1386 } 1387 } 1388 for (i = 0; i < range; i++) { 1389 if (zerolength[i] > longest) { 1390 longest = zerolength[i]; 1391 colonpos = i; 1392 } 1393 } 1394 if (longest == 1) /* don't compress a single 0 */ 1395 colonpos = -1; 1396 1397 /* emit address */ 1398 for (i = 0; i < range; i++) { 1399 if (i == colonpos) { 1400 if (needcolon || i == 0) 1401 *p++ = ':'; 1402 *p++ = ':'; 1403 needcolon = false; 1404 i += longest - 1; 1405 continue; 1406 } 1407 if (needcolon) { 1408 *p++ = ':'; 1409 needcolon = false; 1410 } 1411 /* hex u16 without leading 0s */ 1412 word = ntohs(in6.s6_addr16[i]); 1413 hi = word >> 8; 1414 lo = word & 0xff; 1415 if (hi) { 1416 if (hi > 0x0f) 1417 p = hex_byte_pack(p, hi); 1418 else 1419 *p++ = hex_asc_lo(hi); 1420 p = hex_byte_pack(p, lo); 1421 } 1422 else if (lo > 0x0f) 1423 p = hex_byte_pack(p, lo); 1424 else 1425 *p++ = hex_asc_lo(lo); 1426 needcolon = true; 1427 } 1428 1429 if (useIPv4) { 1430 if (needcolon) 1431 *p++ = ':'; 1432 p = ip4_string(p, &in6.s6_addr[12], "I4"); 1433 } 1434 *p = '\0'; 1435 1436 return p; 1437 } 1438 1439 static noinline_for_stack 1440 char *ip6_string(char *p, const char *addr, const char *fmt) 1441 { 1442 int i; 1443 1444 for (i = 0; i < 8; i++) { 1445 p = hex_byte_pack(p, *addr++); 1446 p = hex_byte_pack(p, *addr++); 1447 if (fmt[0] == 'I' && i != 7) 1448 *p++ = ':'; 1449 } 1450 *p = '\0'; 1451 1452 return p; 1453 } 1454 1455 static noinline_for_stack 1456 char *ip6_addr_string(char *buf, char *end, const u8 *addr, 1457 struct printf_spec spec, const char *fmt) 1458 { 1459 char ip6_addr[sizeof("xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255")]; 1460 1461 if (fmt[0] == 'I' && fmt[2] == 'c') 1462 ip6_compressed_string(ip6_addr, addr); 1463 else 1464 ip6_string(ip6_addr, addr, fmt); 1465 1466 return string_nocheck(buf, end, ip6_addr, spec); 1467 } 1468 1469 static noinline_for_stack 1470 char *ip4_addr_string(char *buf, char *end, const u8 *addr, 1471 struct printf_spec spec, const char *fmt) 1472 { 1473 char ip4_addr[sizeof("255.255.255.255")]; 1474 1475 ip4_string(ip4_addr, addr, fmt); 1476 1477 return string_nocheck(buf, end, ip4_addr, spec); 1478 } 1479 1480 static noinline_for_stack 1481 char *ip6_addr_string_sa(char *buf, char *end, const struct sockaddr_in6 *sa, 1482 struct printf_spec spec, const char *fmt) 1483 { 1484 bool have_p = false, have_s = false, have_f = false, have_c = false; 1485 char ip6_addr[sizeof("[xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255]") + 1486 sizeof(":12345") + sizeof("/123456789") + 1487 sizeof("%1234567890")]; 1488 char *p = ip6_addr, *pend = ip6_addr + sizeof(ip6_addr); 1489 const u8 *addr = (const u8 *) &sa->sin6_addr; 1490 char fmt6[2] = { fmt[0], '6' }; 1491 u8 off = 0; 1492 1493 fmt++; 1494 while (isalpha(*++fmt)) { 1495 switch (*fmt) { 1496 case 'p': 1497 have_p = true; 1498 break; 1499 case 'f': 1500 have_f = true; 1501 break; 1502 case 's': 1503 have_s = true; 1504 break; 1505 case 'c': 1506 have_c = true; 1507 break; 1508 } 1509 } 1510 1511 if (have_p || have_s || have_f) { 1512 *p = '['; 1513 off = 1; 1514 } 1515 1516 if (fmt6[0] == 'I' && have_c) 1517 p = ip6_compressed_string(ip6_addr + off, addr); 1518 else 1519 p = ip6_string(ip6_addr + off, addr, fmt6); 1520 1521 if (have_p || have_s || have_f) 1522 *p++ = ']'; 1523 1524 if (have_p) { 1525 *p++ = ':'; 1526 p = number(p, pend, ntohs(sa->sin6_port), spec); 1527 } 1528 if (have_f) { 1529 *p++ = '/'; 1530 p = number(p, pend, ntohl(sa->sin6_flowinfo & 1531 IPV6_FLOWINFO_MASK), spec); 1532 } 1533 if (have_s) { 1534 *p++ = '%'; 1535 p = number(p, pend, sa->sin6_scope_id, spec); 1536 } 1537 *p = '\0'; 1538 1539 return string_nocheck(buf, end, ip6_addr, spec); 1540 } 1541 1542 static noinline_for_stack 1543 char *ip4_addr_string_sa(char *buf, char *end, const struct sockaddr_in *sa, 1544 struct printf_spec spec, const char *fmt) 1545 { 1546 bool have_p = false; 1547 char *p, ip4_addr[sizeof("255.255.255.255") + sizeof(":12345")]; 1548 char *pend = ip4_addr + sizeof(ip4_addr); 1549 const u8 *addr = (const u8 *) &sa->sin_addr.s_addr; 1550 char fmt4[3] = { fmt[0], '4', 0 }; 1551 1552 fmt++; 1553 while (isalpha(*++fmt)) { 1554 switch (*fmt) { 1555 case 'p': 1556 have_p = true; 1557 break; 1558 case 'h': 1559 case 'l': 1560 case 'n': 1561 case 'b': 1562 fmt4[2] = *fmt; 1563 break; 1564 } 1565 } 1566 1567 p = ip4_string(ip4_addr, addr, fmt4); 1568 if (have_p) { 1569 *p++ = ':'; 1570 p = number(p, pend, ntohs(sa->sin_port), spec); 1571 } 1572 *p = '\0'; 1573 1574 return string_nocheck(buf, end, ip4_addr, spec); 1575 } 1576 1577 static noinline_for_stack 1578 char *ip_addr_string(char *buf, char *end, const void *ptr, 1579 struct printf_spec spec, const char *fmt) 1580 { 1581 char *err_fmt_msg; 1582 1583 if (check_pointer(&buf, end, ptr, spec)) 1584 return buf; 1585 1586 switch (fmt[1]) { 1587 case '6': 1588 return ip6_addr_string(buf, end, ptr, spec, fmt); 1589 case '4': 1590 return ip4_addr_string(buf, end, ptr, spec, fmt); 1591 case 'S': { 1592 const union { 1593 struct sockaddr raw; 1594 struct sockaddr_in v4; 1595 struct sockaddr_in6 v6; 1596 } *sa = ptr; 1597 1598 switch (sa->raw.sa_family) { 1599 case AF_INET: 1600 return ip4_addr_string_sa(buf, end, &sa->v4, spec, fmt); 1601 case AF_INET6: 1602 return ip6_addr_string_sa(buf, end, &sa->v6, spec, fmt); 1603 default: 1604 return error_string(buf, end, "(einval)", spec); 1605 }} 1606 } 1607 1608 err_fmt_msg = fmt[0] == 'i' ? "(%pi?)" : "(%pI?)"; 1609 return error_string(buf, end, err_fmt_msg, spec); 1610 } 1611 1612 static noinline_for_stack 1613 char *escaped_string(char *buf, char *end, u8 *addr, struct printf_spec spec, 1614 const char *fmt) 1615 { 1616 bool found = true; 1617 int count = 1; 1618 unsigned int flags = 0; 1619 int len; 1620 1621 if (spec.field_width == 0) 1622 return buf; /* nothing to print */ 1623 1624 if (check_pointer(&buf, end, addr, spec)) 1625 return buf; 1626 1627 do { 1628 switch (fmt[count++]) { 1629 case 'a': 1630 flags |= ESCAPE_ANY; 1631 break; 1632 case 'c': 1633 flags |= ESCAPE_SPECIAL; 1634 break; 1635 case 'h': 1636 flags |= ESCAPE_HEX; 1637 break; 1638 case 'n': 1639 flags |= ESCAPE_NULL; 1640 break; 1641 case 'o': 1642 flags |= ESCAPE_OCTAL; 1643 break; 1644 case 'p': 1645 flags |= ESCAPE_NP; 1646 break; 1647 case 's': 1648 flags |= ESCAPE_SPACE; 1649 break; 1650 default: 1651 found = false; 1652 break; 1653 } 1654 } while (found); 1655 1656 if (!flags) 1657 flags = ESCAPE_ANY_NP; 1658 1659 len = spec.field_width < 0 ? 1 : spec.field_width; 1660 1661 /* 1662 * string_escape_mem() writes as many characters as it can to 1663 * the given buffer, and returns the total size of the output 1664 * had the buffer been big enough. 1665 */ 1666 buf += string_escape_mem(addr, len, buf, buf < end ? end - buf : 0, flags, NULL); 1667 1668 return buf; 1669 } 1670 1671 static char *va_format(char *buf, char *end, struct va_format *va_fmt, 1672 struct printf_spec spec, const char *fmt) 1673 { 1674 va_list va; 1675 1676 if (check_pointer(&buf, end, va_fmt, spec)) 1677 return buf; 1678 1679 va_copy(va, *va_fmt->va); 1680 buf += vsnprintf(buf, end > buf ? end - buf : 0, va_fmt->fmt, va); 1681 va_end(va); 1682 1683 return buf; 1684 } 1685 1686 static noinline_for_stack 1687 char *uuid_string(char *buf, char *end, const u8 *addr, 1688 struct printf_spec spec, const char *fmt) 1689 { 1690 char uuid[UUID_STRING_LEN + 1]; 1691 char *p = uuid; 1692 int i; 1693 const u8 *index = uuid_index; 1694 bool uc = false; 1695 1696 if (check_pointer(&buf, end, addr, spec)) 1697 return buf; 1698 1699 switch (*(++fmt)) { 1700 case 'L': 1701 uc = true; 1702 fallthrough; 1703 case 'l': 1704 index = guid_index; 1705 break; 1706 case 'B': 1707 uc = true; 1708 break; 1709 } 1710 1711 for (i = 0; i < 16; i++) { 1712 if (uc) 1713 p = hex_byte_pack_upper(p, addr[index[i]]); 1714 else 1715 p = hex_byte_pack(p, addr[index[i]]); 1716 switch (i) { 1717 case 3: 1718 case 5: 1719 case 7: 1720 case 9: 1721 *p++ = '-'; 1722 break; 1723 } 1724 } 1725 1726 *p = 0; 1727 1728 return string_nocheck(buf, end, uuid, spec); 1729 } 1730 1731 static noinline_for_stack 1732 char *netdev_bits(char *buf, char *end, const void *addr, 1733 struct printf_spec spec, const char *fmt) 1734 { 1735 unsigned long long num; 1736 int size; 1737 1738 if (check_pointer(&buf, end, addr, spec)) 1739 return buf; 1740 1741 switch (fmt[1]) { 1742 case 'F': 1743 num = *(const netdev_features_t *)addr; 1744 size = sizeof(netdev_features_t); 1745 break; 1746 default: 1747 return error_string(buf, end, "(%pN?)", spec); 1748 } 1749 1750 return special_hex_number(buf, end, num, size); 1751 } 1752 1753 static noinline_for_stack 1754 char *fourcc_string(char *buf, char *end, const u32 *fourcc, 1755 struct printf_spec spec, const char *fmt) 1756 { 1757 char output[sizeof("0123 little-endian (0x01234567)")]; 1758 char *p = output; 1759 unsigned int i; 1760 u32 orig, val; 1761 1762 if (fmt[1] != 'c' || fmt[2] != 'c') 1763 return error_string(buf, end, "(%p4?)", spec); 1764 1765 if (check_pointer(&buf, end, fourcc, spec)) 1766 return buf; 1767 1768 orig = get_unaligned(fourcc); 1769 val = orig & ~BIT(31); 1770 1771 for (i = 0; i < sizeof(u32); i++) { 1772 unsigned char c = val >> (i * 8); 1773 1774 /* Print non-control ASCII characters as-is, dot otherwise */ 1775 *p++ = isascii(c) && isprint(c) ? c : '.'; 1776 } 1777 1778 *p++ = ' '; 1779 strcpy(p, orig & BIT(31) ? "big-endian" : "little-endian"); 1780 p += strlen(p); 1781 1782 *p++ = ' '; 1783 *p++ = '('; 1784 p = special_hex_number(p, output + sizeof(output) - 2, orig, sizeof(u32)); 1785 *p++ = ')'; 1786 *p = '\0'; 1787 1788 return string(buf, end, output, spec); 1789 } 1790 1791 static noinline_for_stack 1792 char *address_val(char *buf, char *end, const void *addr, 1793 struct printf_spec spec, const char *fmt) 1794 { 1795 unsigned long long num; 1796 int size; 1797 1798 if (check_pointer(&buf, end, addr, spec)) 1799 return buf; 1800 1801 switch (fmt[1]) { 1802 case 'd': 1803 num = *(const dma_addr_t *)addr; 1804 size = sizeof(dma_addr_t); 1805 break; 1806 case 'p': 1807 default: 1808 num = *(const phys_addr_t *)addr; 1809 size = sizeof(phys_addr_t); 1810 break; 1811 } 1812 1813 return special_hex_number(buf, end, num, size); 1814 } 1815 1816 static noinline_for_stack 1817 char *date_str(char *buf, char *end, const struct rtc_time *tm, bool r) 1818 { 1819 int year = tm->tm_year + (r ? 0 : 1900); 1820 int mon = tm->tm_mon + (r ? 0 : 1); 1821 1822 buf = number(buf, end, year, default_dec04_spec); 1823 if (buf < end) 1824 *buf = '-'; 1825 buf++; 1826 1827 buf = number(buf, end, mon, default_dec02_spec); 1828 if (buf < end) 1829 *buf = '-'; 1830 buf++; 1831 1832 return number(buf, end, tm->tm_mday, default_dec02_spec); 1833 } 1834 1835 static noinline_for_stack 1836 char *time_str(char *buf, char *end, const struct rtc_time *tm, bool r) 1837 { 1838 buf = number(buf, end, tm->tm_hour, default_dec02_spec); 1839 if (buf < end) 1840 *buf = ':'; 1841 buf++; 1842 1843 buf = number(buf, end, tm->tm_min, default_dec02_spec); 1844 if (buf < end) 1845 *buf = ':'; 1846 buf++; 1847 1848 return number(buf, end, tm->tm_sec, default_dec02_spec); 1849 } 1850 1851 static noinline_for_stack 1852 char *rtc_str(char *buf, char *end, const struct rtc_time *tm, 1853 struct printf_spec spec, const char *fmt) 1854 { 1855 bool have_t = true, have_d = true; 1856 bool raw = false, iso8601_separator = true; 1857 bool found = true; 1858 int count = 2; 1859 1860 if (check_pointer(&buf, end, tm, spec)) 1861 return buf; 1862 1863 switch (fmt[count]) { 1864 case 'd': 1865 have_t = false; 1866 count++; 1867 break; 1868 case 't': 1869 have_d = false; 1870 count++; 1871 break; 1872 } 1873 1874 do { 1875 switch (fmt[count++]) { 1876 case 'r': 1877 raw = true; 1878 break; 1879 case 's': 1880 iso8601_separator = false; 1881 break; 1882 default: 1883 found = false; 1884 break; 1885 } 1886 } while (found); 1887 1888 if (have_d) 1889 buf = date_str(buf, end, tm, raw); 1890 if (have_d && have_t) { 1891 if (buf < end) 1892 *buf = iso8601_separator ? 'T' : ' '; 1893 buf++; 1894 } 1895 if (have_t) 1896 buf = time_str(buf, end, tm, raw); 1897 1898 return buf; 1899 } 1900 1901 static noinline_for_stack 1902 char *time64_str(char *buf, char *end, const time64_t time, 1903 struct printf_spec spec, const char *fmt) 1904 { 1905 struct rtc_time rtc_time; 1906 struct tm tm; 1907 1908 time64_to_tm(time, 0, &tm); 1909 1910 rtc_time.tm_sec = tm.tm_sec; 1911 rtc_time.tm_min = tm.tm_min; 1912 rtc_time.tm_hour = tm.tm_hour; 1913 rtc_time.tm_mday = tm.tm_mday; 1914 rtc_time.tm_mon = tm.tm_mon; 1915 rtc_time.tm_year = tm.tm_year; 1916 rtc_time.tm_wday = tm.tm_wday; 1917 rtc_time.tm_yday = tm.tm_yday; 1918 1919 rtc_time.tm_isdst = 0; 1920 1921 return rtc_str(buf, end, &rtc_time, spec, fmt); 1922 } 1923 1924 static noinline_for_stack 1925 char *time_and_date(char *buf, char *end, void *ptr, struct printf_spec spec, 1926 const char *fmt) 1927 { 1928 switch (fmt[1]) { 1929 case 'R': 1930 return rtc_str(buf, end, (const struct rtc_time *)ptr, spec, fmt); 1931 case 'T': 1932 return time64_str(buf, end, *(const time64_t *)ptr, spec, fmt); 1933 default: 1934 return error_string(buf, end, "(%pt?)", spec); 1935 } 1936 } 1937 1938 static noinline_for_stack 1939 char *clock(char *buf, char *end, struct clk *clk, struct printf_spec spec, 1940 const char *fmt) 1941 { 1942 if (!IS_ENABLED(CONFIG_HAVE_CLK)) 1943 return error_string(buf, end, "(%pC?)", spec); 1944 1945 if (check_pointer(&buf, end, clk, spec)) 1946 return buf; 1947 1948 switch (fmt[1]) { 1949 case 'n': 1950 default: 1951 #ifdef CONFIG_COMMON_CLK 1952 return string(buf, end, __clk_get_name(clk), spec); 1953 #else 1954 return ptr_to_id(buf, end, clk, spec); 1955 #endif 1956 } 1957 } 1958 1959 static 1960 char *format_flags(char *buf, char *end, unsigned long flags, 1961 const struct trace_print_flags *names) 1962 { 1963 unsigned long mask; 1964 1965 for ( ; flags && names->name; names++) { 1966 mask = names->mask; 1967 if ((flags & mask) != mask) 1968 continue; 1969 1970 buf = string(buf, end, names->name, default_str_spec); 1971 1972 flags &= ~mask; 1973 if (flags) { 1974 if (buf < end) 1975 *buf = '|'; 1976 buf++; 1977 } 1978 } 1979 1980 if (flags) 1981 buf = number(buf, end, flags, default_flag_spec); 1982 1983 return buf; 1984 } 1985 1986 struct page_flags_fields { 1987 int width; 1988 int shift; 1989 int mask; 1990 const struct printf_spec *spec; 1991 const char *name; 1992 }; 1993 1994 static const struct page_flags_fields pff[] = { 1995 {SECTIONS_WIDTH, SECTIONS_PGSHIFT, SECTIONS_MASK, 1996 &default_dec_spec, "section"}, 1997 {NODES_WIDTH, NODES_PGSHIFT, NODES_MASK, 1998 &default_dec_spec, "node"}, 1999 {ZONES_WIDTH, ZONES_PGSHIFT, ZONES_MASK, 2000 &default_dec_spec, "zone"}, 2001 {LAST_CPUPID_WIDTH, LAST_CPUPID_PGSHIFT, LAST_CPUPID_MASK, 2002 &default_flag_spec, "lastcpupid"}, 2003 {KASAN_TAG_WIDTH, KASAN_TAG_PGSHIFT, KASAN_TAG_MASK, 2004 &default_flag_spec, "kasantag"}, 2005 }; 2006 2007 static 2008 char *format_page_flags(char *buf, char *end, unsigned long flags) 2009 { 2010 unsigned long main_flags = flags & PAGEFLAGS_MASK; 2011 bool append = false; 2012 int i; 2013 2014 buf = number(buf, end, flags, default_flag_spec); 2015 if (buf < end) 2016 *buf = '('; 2017 buf++; 2018 2019 /* Page flags from the main area. */ 2020 if (main_flags) { 2021 buf = format_flags(buf, end, main_flags, pageflag_names); 2022 append = true; 2023 } 2024 2025 /* Page flags from the fields area */ 2026 for (i = 0; i < ARRAY_SIZE(pff); i++) { 2027 /* Skip undefined fields. */ 2028 if (!pff[i].width) 2029 continue; 2030 2031 /* Format: Flag Name + '=' (equals sign) + Number + '|' (separator) */ 2032 if (append) { 2033 if (buf < end) 2034 *buf = '|'; 2035 buf++; 2036 } 2037 2038 buf = string(buf, end, pff[i].name, default_str_spec); 2039 if (buf < end) 2040 *buf = '='; 2041 buf++; 2042 buf = number(buf, end, (flags >> pff[i].shift) & pff[i].mask, 2043 *pff[i].spec); 2044 2045 append = true; 2046 } 2047 if (buf < end) 2048 *buf = ')'; 2049 buf++; 2050 2051 return buf; 2052 } 2053 2054 static noinline_for_stack 2055 char *flags_string(char *buf, char *end, void *flags_ptr, 2056 struct printf_spec spec, const char *fmt) 2057 { 2058 unsigned long flags; 2059 const struct trace_print_flags *names; 2060 2061 if (check_pointer(&buf, end, flags_ptr, spec)) 2062 return buf; 2063 2064 switch (fmt[1]) { 2065 case 'p': 2066 return format_page_flags(buf, end, *(unsigned long *)flags_ptr); 2067 case 'v': 2068 flags = *(unsigned long *)flags_ptr; 2069 names = vmaflag_names; 2070 break; 2071 case 'g': 2072 flags = (__force unsigned long)(*(gfp_t *)flags_ptr); 2073 names = gfpflag_names; 2074 break; 2075 default: 2076 return error_string(buf, end, "(%pG?)", spec); 2077 } 2078 2079 return format_flags(buf, end, flags, names); 2080 } 2081 2082 static noinline_for_stack 2083 char *fwnode_full_name_string(struct fwnode_handle *fwnode, char *buf, 2084 char *end) 2085 { 2086 int depth; 2087 2088 /* Loop starting from the root node to the current node. */ 2089 for (depth = fwnode_count_parents(fwnode); depth >= 0; depth--) { 2090 struct fwnode_handle *__fwnode = 2091 fwnode_get_nth_parent(fwnode, depth); 2092 2093 buf = string(buf, end, fwnode_get_name_prefix(__fwnode), 2094 default_str_spec); 2095 buf = string(buf, end, fwnode_get_name(__fwnode), 2096 default_str_spec); 2097 2098 fwnode_handle_put(__fwnode); 2099 } 2100 2101 return buf; 2102 } 2103 2104 static noinline_for_stack 2105 char *device_node_string(char *buf, char *end, struct device_node *dn, 2106 struct printf_spec spec, const char *fmt) 2107 { 2108 char tbuf[sizeof("xxxx") + 1]; 2109 const char *p; 2110 int ret; 2111 char *buf_start = buf; 2112 struct property *prop; 2113 bool has_mult, pass; 2114 2115 struct printf_spec str_spec = spec; 2116 str_spec.field_width = -1; 2117 2118 if (fmt[0] != 'F') 2119 return error_string(buf, end, "(%pO?)", spec); 2120 2121 if (!IS_ENABLED(CONFIG_OF)) 2122 return error_string(buf, end, "(%pOF?)", spec); 2123 2124 if (check_pointer(&buf, end, dn, spec)) 2125 return buf; 2126 2127 /* simple case without anything any more format specifiers */ 2128 fmt++; 2129 if (fmt[0] == '\0' || strcspn(fmt,"fnpPFcC") > 0) 2130 fmt = "f"; 2131 2132 for (pass = false; strspn(fmt,"fnpPFcC"); fmt++, pass = true) { 2133 int precision; 2134 if (pass) { 2135 if (buf < end) 2136 *buf = ':'; 2137 buf++; 2138 } 2139 2140 switch (*fmt) { 2141 case 'f': /* full_name */ 2142 buf = fwnode_full_name_string(of_fwnode_handle(dn), buf, 2143 end); 2144 break; 2145 case 'n': /* name */ 2146 p = fwnode_get_name(of_fwnode_handle(dn)); 2147 precision = str_spec.precision; 2148 str_spec.precision = strchrnul(p, '@') - p; 2149 buf = string(buf, end, p, str_spec); 2150 str_spec.precision = precision; 2151 break; 2152 case 'p': /* phandle */ 2153 buf = number(buf, end, (unsigned int)dn->phandle, default_dec_spec); 2154 break; 2155 case 'P': /* path-spec */ 2156 p = fwnode_get_name(of_fwnode_handle(dn)); 2157 if (!p[1]) 2158 p = "/"; 2159 buf = string(buf, end, p, str_spec); 2160 break; 2161 case 'F': /* flags */ 2162 tbuf[0] = of_node_check_flag(dn, OF_DYNAMIC) ? 'D' : '-'; 2163 tbuf[1] = of_node_check_flag(dn, OF_DETACHED) ? 'd' : '-'; 2164 tbuf[2] = of_node_check_flag(dn, OF_POPULATED) ? 'P' : '-'; 2165 tbuf[3] = of_node_check_flag(dn, OF_POPULATED_BUS) ? 'B' : '-'; 2166 tbuf[4] = 0; 2167 buf = string_nocheck(buf, end, tbuf, str_spec); 2168 break; 2169 case 'c': /* major compatible string */ 2170 ret = of_property_read_string(dn, "compatible", &p); 2171 if (!ret) 2172 buf = string(buf, end, p, str_spec); 2173 break; 2174 case 'C': /* full compatible string */ 2175 has_mult = false; 2176 of_property_for_each_string(dn, "compatible", prop, p) { 2177 if (has_mult) 2178 buf = string_nocheck(buf, end, ",", str_spec); 2179 buf = string_nocheck(buf, end, "\"", str_spec); 2180 buf = string(buf, end, p, str_spec); 2181 buf = string_nocheck(buf, end, "\"", str_spec); 2182 2183 has_mult = true; 2184 } 2185 break; 2186 default: 2187 break; 2188 } 2189 } 2190 2191 return widen_string(buf, buf - buf_start, end, spec); 2192 } 2193 2194 static noinline_for_stack 2195 char *fwnode_string(char *buf, char *end, struct fwnode_handle *fwnode, 2196 struct printf_spec spec, const char *fmt) 2197 { 2198 struct printf_spec str_spec = spec; 2199 char *buf_start = buf; 2200 2201 str_spec.field_width = -1; 2202 2203 if (*fmt != 'w') 2204 return error_string(buf, end, "(%pf?)", spec); 2205 2206 if (check_pointer(&buf, end, fwnode, spec)) 2207 return buf; 2208 2209 fmt++; 2210 2211 switch (*fmt) { 2212 case 'P': /* name */ 2213 buf = string(buf, end, fwnode_get_name(fwnode), str_spec); 2214 break; 2215 case 'f': /* full_name */ 2216 default: 2217 buf = fwnode_full_name_string(fwnode, buf, end); 2218 break; 2219 } 2220 2221 return widen_string(buf, buf - buf_start, end, spec); 2222 } 2223 2224 int __init no_hash_pointers_enable(char *str) 2225 { 2226 if (no_hash_pointers) 2227 return 0; 2228 2229 no_hash_pointers = true; 2230 2231 pr_warn("**********************************************************\n"); 2232 pr_warn("** NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE **\n"); 2233 pr_warn("** **\n"); 2234 pr_warn("** This system shows unhashed kernel memory addresses **\n"); 2235 pr_warn("** via the console, logs, and other interfaces. This **\n"); 2236 pr_warn("** might reduce the security of your system. **\n"); 2237 pr_warn("** **\n"); 2238 pr_warn("** If you see this message and you are not debugging **\n"); 2239 pr_warn("** the kernel, report this immediately to your system **\n"); 2240 pr_warn("** administrator! **\n"); 2241 pr_warn("** **\n"); 2242 pr_warn("** NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE **\n"); 2243 pr_warn("**********************************************************\n"); 2244 2245 return 0; 2246 } 2247 early_param("no_hash_pointers", no_hash_pointers_enable); 2248 2249 /* 2250 * Show a '%p' thing. A kernel extension is that the '%p' is followed 2251 * by an extra set of alphanumeric characters that are extended format 2252 * specifiers. 2253 * 2254 * Please update scripts/checkpatch.pl when adding/removing conversion 2255 * characters. (Search for "check for vsprintf extension"). 2256 * 2257 * Right now we handle: 2258 * 2259 * - 'S' For symbolic direct pointers (or function descriptors) with offset 2260 * - 's' For symbolic direct pointers (or function descriptors) without offset 2261 * - '[Ss]R' as above with __builtin_extract_return_addr() translation 2262 * - 'S[R]b' as above with module build ID (for use in backtraces) 2263 * - '[Ff]' %pf and %pF were obsoleted and later removed in favor of 2264 * %ps and %pS. Be careful when re-using these specifiers. 2265 * - 'B' For backtraced symbolic direct pointers with offset 2266 * - 'Bb' as above with module build ID (for use in backtraces) 2267 * - 'R' For decoded struct resource, e.g., [mem 0x0-0x1f 64bit pref] 2268 * - 'r' For raw struct resource, e.g., [mem 0x0-0x1f flags 0x201] 2269 * - 'b[l]' For a bitmap, the number of bits is determined by the field 2270 * width which must be explicitly specified either as part of the 2271 * format string '%32b[l]' or through '%*b[l]', [l] selects 2272 * range-list format instead of hex format 2273 * - 'M' For a 6-byte MAC address, it prints the address in the 2274 * usual colon-separated hex notation 2275 * - 'm' For a 6-byte MAC address, it prints the hex address without colons 2276 * - 'MF' For a 6-byte MAC FDDI address, it prints the address 2277 * with a dash-separated hex notation 2278 * - '[mM]R' For a 6-byte MAC address, Reverse order (Bluetooth) 2279 * - 'I' [46] for IPv4/IPv6 addresses printed in the usual way 2280 * IPv4 uses dot-separated decimal without leading 0's (1.2.3.4) 2281 * IPv6 uses colon separated network-order 16 bit hex with leading 0's 2282 * [S][pfs] 2283 * Generic IPv4/IPv6 address (struct sockaddr *) that falls back to 2284 * [4] or [6] and is able to print port [p], flowinfo [f], scope [s] 2285 * - 'i' [46] for 'raw' IPv4/IPv6 addresses 2286 * IPv6 omits the colons (01020304...0f) 2287 * IPv4 uses dot-separated decimal with leading 0's (010.123.045.006) 2288 * [S][pfs] 2289 * Generic IPv4/IPv6 address (struct sockaddr *) that falls back to 2290 * [4] or [6] and is able to print port [p], flowinfo [f], scope [s] 2291 * - '[Ii][4S][hnbl]' IPv4 addresses in host, network, big or little endian order 2292 * - 'I[6S]c' for IPv6 addresses printed as specified by 2293 * https://tools.ietf.org/html/rfc5952 2294 * - 'E[achnops]' For an escaped buffer, where rules are defined by combination 2295 * of the following flags (see string_escape_mem() for the 2296 * details): 2297 * a - ESCAPE_ANY 2298 * c - ESCAPE_SPECIAL 2299 * h - ESCAPE_HEX 2300 * n - ESCAPE_NULL 2301 * o - ESCAPE_OCTAL 2302 * p - ESCAPE_NP 2303 * s - ESCAPE_SPACE 2304 * By default ESCAPE_ANY_NP is used. 2305 * - 'U' For a 16 byte UUID/GUID, it prints the UUID/GUID in the form 2306 * "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx" 2307 * Options for %pU are: 2308 * b big endian lower case hex (default) 2309 * B big endian UPPER case hex 2310 * l little endian lower case hex 2311 * L little endian UPPER case hex 2312 * big endian output byte order is: 2313 * [0][1][2][3]-[4][5]-[6][7]-[8][9]-[10][11][12][13][14][15] 2314 * little endian output byte order is: 2315 * [3][2][1][0]-[5][4]-[7][6]-[8][9]-[10][11][12][13][14][15] 2316 * - 'V' For a struct va_format which contains a format string * and va_list *, 2317 * call vsnprintf(->format, *->va_list). 2318 * Implements a "recursive vsnprintf". 2319 * Do not use this feature without some mechanism to verify the 2320 * correctness of the format string and va_list arguments. 2321 * - 'K' For a kernel pointer that should be hidden from unprivileged users. 2322 * Use only for procfs, sysfs and similar files, not printk(); please 2323 * read the documentation (path below) first. 2324 * - 'NF' For a netdev_features_t 2325 * - '4cc' V4L2 or DRM FourCC code, with endianness and raw numerical value. 2326 * - 'h[CDN]' For a variable-length buffer, it prints it as a hex string with 2327 * a certain separator (' ' by default): 2328 * C colon 2329 * D dash 2330 * N no separator 2331 * The maximum supported length is 64 bytes of the input. Consider 2332 * to use print_hex_dump() for the larger input. 2333 * - 'a[pd]' For address types [p] phys_addr_t, [d] dma_addr_t and derivatives 2334 * (default assumed to be phys_addr_t, passed by reference) 2335 * - 'd[234]' For a dentry name (optionally 2-4 last components) 2336 * - 'D[234]' Same as 'd' but for a struct file 2337 * - 'g' For block_device name (gendisk + partition number) 2338 * - 't[RT][dt][r][s]' For time and date as represented by: 2339 * R struct rtc_time 2340 * T time64_t 2341 * - 'C' For a clock, it prints the name (Common Clock Framework) or address 2342 * (legacy clock framework) of the clock 2343 * - 'Cn' For a clock, it prints the name (Common Clock Framework) or address 2344 * (legacy clock framework) of the clock 2345 * - 'G' For flags to be printed as a collection of symbolic strings that would 2346 * construct the specific value. Supported flags given by option: 2347 * p page flags (see struct page) given as pointer to unsigned long 2348 * g gfp flags (GFP_* and __GFP_*) given as pointer to gfp_t 2349 * v vma flags (VM_*) given as pointer to unsigned long 2350 * - 'OF[fnpPcCF]' For a device tree object 2351 * Without any optional arguments prints the full_name 2352 * f device node full_name 2353 * n device node name 2354 * p device node phandle 2355 * P device node path spec (name + @unit) 2356 * F device node flags 2357 * c major compatible string 2358 * C full compatible string 2359 * - 'fw[fP]' For a firmware node (struct fwnode_handle) pointer 2360 * Without an option prints the full name of the node 2361 * f full name 2362 * P node name, including a possible unit address 2363 * - 'x' For printing the address unmodified. Equivalent to "%lx". 2364 * Please read the documentation (path below) before using! 2365 * - '[ku]s' For a BPF/tracing related format specifier, e.g. used out of 2366 * bpf_trace_printk() where [ku] prefix specifies either kernel (k) 2367 * or user (u) memory to probe, and: 2368 * s a string, equivalent to "%s" on direct vsnprintf() use 2369 * 2370 * ** When making changes please also update: 2371 * Documentation/core-api/printk-formats.rst 2372 * 2373 * Note: The default behaviour (unadorned %p) is to hash the address, 2374 * rendering it useful as a unique identifier. 2375 */ 2376 static noinline_for_stack 2377 char *pointer(const char *fmt, char *buf, char *end, void *ptr, 2378 struct printf_spec spec) 2379 { 2380 switch (*fmt) { 2381 case 'S': 2382 case 's': 2383 ptr = dereference_symbol_descriptor(ptr); 2384 fallthrough; 2385 case 'B': 2386 return symbol_string(buf, end, ptr, spec, fmt); 2387 case 'R': 2388 case 'r': 2389 return resource_string(buf, end, ptr, spec, fmt); 2390 case 'h': 2391 return hex_string(buf, end, ptr, spec, fmt); 2392 case 'b': 2393 switch (fmt[1]) { 2394 case 'l': 2395 return bitmap_list_string(buf, end, ptr, spec, fmt); 2396 default: 2397 return bitmap_string(buf, end, ptr, spec, fmt); 2398 } 2399 case 'M': /* Colon separated: 00:01:02:03:04:05 */ 2400 case 'm': /* Contiguous: 000102030405 */ 2401 /* [mM]F (FDDI) */ 2402 /* [mM]R (Reverse order; Bluetooth) */ 2403 return mac_address_string(buf, end, ptr, spec, fmt); 2404 case 'I': /* Formatted IP supported 2405 * 4: 1.2.3.4 2406 * 6: 0001:0203:...:0708 2407 * 6c: 1::708 or 1::1.2.3.4 2408 */ 2409 case 'i': /* Contiguous: 2410 * 4: 001.002.003.004 2411 * 6: 000102...0f 2412 */ 2413 return ip_addr_string(buf, end, ptr, spec, fmt); 2414 case 'E': 2415 return escaped_string(buf, end, ptr, spec, fmt); 2416 case 'U': 2417 return uuid_string(buf, end, ptr, spec, fmt); 2418 case 'V': 2419 return va_format(buf, end, ptr, spec, fmt); 2420 case 'K': 2421 return restricted_pointer(buf, end, ptr, spec); 2422 case 'N': 2423 return netdev_bits(buf, end, ptr, spec, fmt); 2424 case '4': 2425 return fourcc_string(buf, end, ptr, spec, fmt); 2426 case 'a': 2427 return address_val(buf, end, ptr, spec, fmt); 2428 case 'd': 2429 return dentry_name(buf, end, ptr, spec, fmt); 2430 case 't': 2431 return time_and_date(buf, end, ptr, spec, fmt); 2432 case 'C': 2433 return clock(buf, end, ptr, spec, fmt); 2434 case 'D': 2435 return file_dentry_name(buf, end, ptr, spec, fmt); 2436 #ifdef CONFIG_BLOCK 2437 case 'g': 2438 return bdev_name(buf, end, ptr, spec, fmt); 2439 #endif 2440 2441 case 'G': 2442 return flags_string(buf, end, ptr, spec, fmt); 2443 case 'O': 2444 return device_node_string(buf, end, ptr, spec, fmt + 1); 2445 case 'f': 2446 return fwnode_string(buf, end, ptr, spec, fmt + 1); 2447 case 'x': 2448 return pointer_string(buf, end, ptr, spec); 2449 case 'e': 2450 /* %pe with a non-ERR_PTR gets treated as plain %p */ 2451 if (!IS_ERR(ptr)) 2452 return default_pointer(buf, end, ptr, spec); 2453 return err_ptr(buf, end, ptr, spec); 2454 case 'u': 2455 case 'k': 2456 switch (fmt[1]) { 2457 case 's': 2458 return string(buf, end, ptr, spec); 2459 default: 2460 return error_string(buf, end, "(einval)", spec); 2461 } 2462 default: 2463 return default_pointer(buf, end, ptr, spec); 2464 } 2465 } 2466 2467 /* 2468 * Helper function to decode printf style format. 2469 * Each call decode a token from the format and return the 2470 * number of characters read (or likely the delta where it wants 2471 * to go on the next call). 2472 * The decoded token is returned through the parameters 2473 * 2474 * 'h', 'l', or 'L' for integer fields 2475 * 'z' support added 23/7/1999 S.H. 2476 * 'z' changed to 'Z' --davidm 1/25/99 2477 * 'Z' changed to 'z' --adobriyan 2017-01-25 2478 * 't' added for ptrdiff_t 2479 * 2480 * @fmt: the format string 2481 * @type of the token returned 2482 * @flags: various flags such as +, -, # tokens.. 2483 * @field_width: overwritten width 2484 * @base: base of the number (octal, hex, ...) 2485 * @precision: precision of a number 2486 * @qualifier: qualifier of a number (long, size_t, ...) 2487 */ 2488 static noinline_for_stack 2489 int format_decode(const char *fmt, struct printf_spec *spec) 2490 { 2491 const char *start = fmt; 2492 char qualifier; 2493 2494 /* we finished early by reading the field width */ 2495 if (spec->type == FORMAT_TYPE_WIDTH) { 2496 if (spec->field_width < 0) { 2497 spec->field_width = -spec->field_width; 2498 spec->flags |= LEFT; 2499 } 2500 spec->type = FORMAT_TYPE_NONE; 2501 goto precision; 2502 } 2503 2504 /* we finished early by reading the precision */ 2505 if (spec->type == FORMAT_TYPE_PRECISION) { 2506 if (spec->precision < 0) 2507 spec->precision = 0; 2508 2509 spec->type = FORMAT_TYPE_NONE; 2510 goto qualifier; 2511 } 2512 2513 /* By default */ 2514 spec->type = FORMAT_TYPE_NONE; 2515 2516 for (; *fmt ; ++fmt) { 2517 if (*fmt == '%') 2518 break; 2519 } 2520 2521 /* Return the current non-format string */ 2522 if (fmt != start || !*fmt) 2523 return fmt - start; 2524 2525 /* Process flags */ 2526 spec->flags = 0; 2527 2528 while (1) { /* this also skips first '%' */ 2529 bool found = true; 2530 2531 ++fmt; 2532 2533 switch (*fmt) { 2534 case '-': spec->flags |= LEFT; break; 2535 case '+': spec->flags |= PLUS; break; 2536 case ' ': spec->flags |= SPACE; break; 2537 case '#': spec->flags |= SPECIAL; break; 2538 case '0': spec->flags |= ZEROPAD; break; 2539 default: found = false; 2540 } 2541 2542 if (!found) 2543 break; 2544 } 2545 2546 /* get field width */ 2547 spec->field_width = -1; 2548 2549 if (isdigit(*fmt)) 2550 spec->field_width = skip_atoi(&fmt); 2551 else if (*fmt == '*') { 2552 /* it's the next argument */ 2553 spec->type = FORMAT_TYPE_WIDTH; 2554 return ++fmt - start; 2555 } 2556 2557 precision: 2558 /* get the precision */ 2559 spec->precision = -1; 2560 if (*fmt == '.') { 2561 ++fmt; 2562 if (isdigit(*fmt)) { 2563 spec->precision = skip_atoi(&fmt); 2564 if (spec->precision < 0) 2565 spec->precision = 0; 2566 } else if (*fmt == '*') { 2567 /* it's the next argument */ 2568 spec->type = FORMAT_TYPE_PRECISION; 2569 return ++fmt - start; 2570 } 2571 } 2572 2573 qualifier: 2574 /* get the conversion qualifier */ 2575 qualifier = 0; 2576 if (*fmt == 'h' || _tolower(*fmt) == 'l' || 2577 *fmt == 'z' || *fmt == 't') { 2578 qualifier = *fmt++; 2579 if (unlikely(qualifier == *fmt)) { 2580 if (qualifier == 'l') { 2581 qualifier = 'L'; 2582 ++fmt; 2583 } else if (qualifier == 'h') { 2584 qualifier = 'H'; 2585 ++fmt; 2586 } 2587 } 2588 } 2589 2590 /* default base */ 2591 spec->base = 10; 2592 switch (*fmt) { 2593 case 'c': 2594 spec->type = FORMAT_TYPE_CHAR; 2595 return ++fmt - start; 2596 2597 case 's': 2598 spec->type = FORMAT_TYPE_STR; 2599 return ++fmt - start; 2600 2601 case 'p': 2602 spec->type = FORMAT_TYPE_PTR; 2603 return ++fmt - start; 2604 2605 case '%': 2606 spec->type = FORMAT_TYPE_PERCENT_CHAR; 2607 return ++fmt - start; 2608 2609 /* integer number formats - set up the flags and "break" */ 2610 case 'o': 2611 spec->base = 8; 2612 break; 2613 2614 case 'x': 2615 spec->flags |= SMALL; 2616 fallthrough; 2617 2618 case 'X': 2619 spec->base = 16; 2620 break; 2621 2622 case 'd': 2623 case 'i': 2624 spec->flags |= SIGN; 2625 break; 2626 case 'u': 2627 break; 2628 2629 case 'n': 2630 /* 2631 * Since %n poses a greater security risk than 2632 * utility, treat it as any other invalid or 2633 * unsupported format specifier. 2634 */ 2635 fallthrough; 2636 2637 default: 2638 WARN_ONCE(1, "Please remove unsupported %%%c in format string\n", *fmt); 2639 spec->type = FORMAT_TYPE_INVALID; 2640 return fmt - start; 2641 } 2642 2643 if (qualifier == 'L') 2644 spec->type = FORMAT_TYPE_LONG_LONG; 2645 else if (qualifier == 'l') { 2646 BUILD_BUG_ON(FORMAT_TYPE_ULONG + SIGN != FORMAT_TYPE_LONG); 2647 spec->type = FORMAT_TYPE_ULONG + (spec->flags & SIGN); 2648 } else if (qualifier == 'z') { 2649 spec->type = FORMAT_TYPE_SIZE_T; 2650 } else if (qualifier == 't') { 2651 spec->type = FORMAT_TYPE_PTRDIFF; 2652 } else if (qualifier == 'H') { 2653 BUILD_BUG_ON(FORMAT_TYPE_UBYTE + SIGN != FORMAT_TYPE_BYTE); 2654 spec->type = FORMAT_TYPE_UBYTE + (spec->flags & SIGN); 2655 } else if (qualifier == 'h') { 2656 BUILD_BUG_ON(FORMAT_TYPE_USHORT + SIGN != FORMAT_TYPE_SHORT); 2657 spec->type = FORMAT_TYPE_USHORT + (spec->flags & SIGN); 2658 } else { 2659 BUILD_BUG_ON(FORMAT_TYPE_UINT + SIGN != FORMAT_TYPE_INT); 2660 spec->type = FORMAT_TYPE_UINT + (spec->flags & SIGN); 2661 } 2662 2663 return ++fmt - start; 2664 } 2665 2666 static void 2667 set_field_width(struct printf_spec *spec, int width) 2668 { 2669 spec->field_width = width; 2670 if (WARN_ONCE(spec->field_width != width, "field width %d too large", width)) { 2671 spec->field_width = clamp(width, -FIELD_WIDTH_MAX, FIELD_WIDTH_MAX); 2672 } 2673 } 2674 2675 static void 2676 set_precision(struct printf_spec *spec, int prec) 2677 { 2678 spec->precision = prec; 2679 if (WARN_ONCE(spec->precision != prec, "precision %d too large", prec)) { 2680 spec->precision = clamp(prec, 0, PRECISION_MAX); 2681 } 2682 } 2683 2684 /** 2685 * vsnprintf - Format a string and place it in a buffer 2686 * @buf: The buffer to place the result into 2687 * @size: The size of the buffer, including the trailing null space 2688 * @fmt: The format string to use 2689 * @args: Arguments for the format string 2690 * 2691 * This function generally follows C99 vsnprintf, but has some 2692 * extensions and a few limitations: 2693 * 2694 * - ``%n`` is unsupported 2695 * - ``%p*`` is handled by pointer() 2696 * 2697 * See pointer() or Documentation/core-api/printk-formats.rst for more 2698 * extensive description. 2699 * 2700 * **Please update the documentation in both places when making changes** 2701 * 2702 * The return value is the number of characters which would 2703 * be generated for the given input, excluding the trailing 2704 * '\0', as per ISO C99. If you want to have the exact 2705 * number of characters written into @buf as return value 2706 * (not including the trailing '\0'), use vscnprintf(). If the 2707 * return is greater than or equal to @size, the resulting 2708 * string is truncated. 2709 * 2710 * If you're not already dealing with a va_list consider using snprintf(). 2711 */ 2712 int vsnprintf(char *buf, size_t size, const char *fmt, va_list args) 2713 { 2714 unsigned long long num; 2715 char *str, *end; 2716 struct printf_spec spec = {0}; 2717 2718 /* Reject out-of-range values early. Large positive sizes are 2719 used for unknown buffer sizes. */ 2720 if (WARN_ON_ONCE(size > INT_MAX)) 2721 return 0; 2722 2723 str = buf; 2724 end = buf + size; 2725 2726 /* Make sure end is always >= buf */ 2727 if (end < buf) { 2728 end = ((void *)-1); 2729 size = end - buf; 2730 } 2731 2732 while (*fmt) { 2733 const char *old_fmt = fmt; 2734 int read = format_decode(fmt, &spec); 2735 2736 fmt += read; 2737 2738 switch (spec.type) { 2739 case FORMAT_TYPE_NONE: { 2740 int copy = read; 2741 if (str < end) { 2742 if (copy > end - str) 2743 copy = end - str; 2744 memcpy(str, old_fmt, copy); 2745 } 2746 str += read; 2747 break; 2748 } 2749 2750 case FORMAT_TYPE_WIDTH: 2751 set_field_width(&spec, va_arg(args, int)); 2752 break; 2753 2754 case FORMAT_TYPE_PRECISION: 2755 set_precision(&spec, va_arg(args, int)); 2756 break; 2757 2758 case FORMAT_TYPE_CHAR: { 2759 char c; 2760 2761 if (!(spec.flags & LEFT)) { 2762 while (--spec.field_width > 0) { 2763 if (str < end) 2764 *str = ' '; 2765 ++str; 2766 2767 } 2768 } 2769 c = (unsigned char) va_arg(args, int); 2770 if (str < end) 2771 *str = c; 2772 ++str; 2773 while (--spec.field_width > 0) { 2774 if (str < end) 2775 *str = ' '; 2776 ++str; 2777 } 2778 break; 2779 } 2780 2781 case FORMAT_TYPE_STR: 2782 str = string(str, end, va_arg(args, char *), spec); 2783 break; 2784 2785 case FORMAT_TYPE_PTR: 2786 str = pointer(fmt, str, end, va_arg(args, void *), 2787 spec); 2788 while (isalnum(*fmt)) 2789 fmt++; 2790 break; 2791 2792 case FORMAT_TYPE_PERCENT_CHAR: 2793 if (str < end) 2794 *str = '%'; 2795 ++str; 2796 break; 2797 2798 case FORMAT_TYPE_INVALID: 2799 /* 2800 * Presumably the arguments passed gcc's type 2801 * checking, but there is no safe or sane way 2802 * for us to continue parsing the format and 2803 * fetching from the va_list; the remaining 2804 * specifiers and arguments would be out of 2805 * sync. 2806 */ 2807 goto out; 2808 2809 default: 2810 switch (spec.type) { 2811 case FORMAT_TYPE_LONG_LONG: 2812 num = va_arg(args, long long); 2813 break; 2814 case FORMAT_TYPE_ULONG: 2815 num = va_arg(args, unsigned long); 2816 break; 2817 case FORMAT_TYPE_LONG: 2818 num = va_arg(args, long); 2819 break; 2820 case FORMAT_TYPE_SIZE_T: 2821 if (spec.flags & SIGN) 2822 num = va_arg(args, ssize_t); 2823 else 2824 num = va_arg(args, size_t); 2825 break; 2826 case FORMAT_TYPE_PTRDIFF: 2827 num = va_arg(args, ptrdiff_t); 2828 break; 2829 case FORMAT_TYPE_UBYTE: 2830 num = (unsigned char) va_arg(args, int); 2831 break; 2832 case FORMAT_TYPE_BYTE: 2833 num = (signed char) va_arg(args, int); 2834 break; 2835 case FORMAT_TYPE_USHORT: 2836 num = (unsigned short) va_arg(args, int); 2837 break; 2838 case FORMAT_TYPE_SHORT: 2839 num = (short) va_arg(args, int); 2840 break; 2841 case FORMAT_TYPE_INT: 2842 num = (int) va_arg(args, int); 2843 break; 2844 default: 2845 num = va_arg(args, unsigned int); 2846 } 2847 2848 str = number(str, end, num, spec); 2849 } 2850 } 2851 2852 out: 2853 if (size > 0) { 2854 if (str < end) 2855 *str = '\0'; 2856 else 2857 end[-1] = '\0'; 2858 } 2859 2860 /* the trailing null byte doesn't count towards the total */ 2861 return str-buf; 2862 2863 } 2864 EXPORT_SYMBOL(vsnprintf); 2865 2866 /** 2867 * vscnprintf - Format a string and place it in a buffer 2868 * @buf: The buffer to place the result into 2869 * @size: The size of the buffer, including the trailing null space 2870 * @fmt: The format string to use 2871 * @args: Arguments for the format string 2872 * 2873 * The return value is the number of characters which have been written into 2874 * the @buf not including the trailing '\0'. If @size is == 0 the function 2875 * returns 0. 2876 * 2877 * If you're not already dealing with a va_list consider using scnprintf(). 2878 * 2879 * See the vsnprintf() documentation for format string extensions over C99. 2880 */ 2881 int vscnprintf(char *buf, size_t size, const char *fmt, va_list args) 2882 { 2883 int i; 2884 2885 if (unlikely(!size)) 2886 return 0; 2887 2888 i = vsnprintf(buf, size, fmt, args); 2889 2890 if (likely(i < size)) 2891 return i; 2892 2893 return size - 1; 2894 } 2895 EXPORT_SYMBOL(vscnprintf); 2896 2897 /** 2898 * snprintf - Format a string and place it in a buffer 2899 * @buf: The buffer to place the result into 2900 * @size: The size of the buffer, including the trailing null space 2901 * @fmt: The format string to use 2902 * @...: Arguments for the format string 2903 * 2904 * The return value is the number of characters which would be 2905 * generated for the given input, excluding the trailing null, 2906 * as per ISO C99. If the return is greater than or equal to 2907 * @size, the resulting string is truncated. 2908 * 2909 * See the vsnprintf() documentation for format string extensions over C99. 2910 */ 2911 int snprintf(char *buf, size_t size, const char *fmt, ...) 2912 { 2913 va_list args; 2914 int i; 2915 2916 va_start(args, fmt); 2917 i = vsnprintf(buf, size, fmt, args); 2918 va_end(args); 2919 2920 return i; 2921 } 2922 EXPORT_SYMBOL(snprintf); 2923 2924 /** 2925 * scnprintf - Format a string and place it in a buffer 2926 * @buf: The buffer to place the result into 2927 * @size: The size of the buffer, including the trailing null space 2928 * @fmt: The format string to use 2929 * @...: Arguments for the format string 2930 * 2931 * The return value is the number of characters written into @buf not including 2932 * the trailing '\0'. If @size is == 0 the function returns 0. 2933 */ 2934 2935 int scnprintf(char *buf, size_t size, const char *fmt, ...) 2936 { 2937 va_list args; 2938 int i; 2939 2940 va_start(args, fmt); 2941 i = vscnprintf(buf, size, fmt, args); 2942 va_end(args); 2943 2944 return i; 2945 } 2946 EXPORT_SYMBOL(scnprintf); 2947 2948 /** 2949 * vsprintf - Format a string and place it in a buffer 2950 * @buf: The buffer to place the result into 2951 * @fmt: The format string to use 2952 * @args: Arguments for the format string 2953 * 2954 * The function returns the number of characters written 2955 * into @buf. Use vsnprintf() or vscnprintf() in order to avoid 2956 * buffer overflows. 2957 * 2958 * If you're not already dealing with a va_list consider using sprintf(). 2959 * 2960 * See the vsnprintf() documentation for format string extensions over C99. 2961 */ 2962 int vsprintf(char *buf, const char *fmt, va_list args) 2963 { 2964 return vsnprintf(buf, INT_MAX, fmt, args); 2965 } 2966 EXPORT_SYMBOL(vsprintf); 2967 2968 /** 2969 * sprintf - Format a string and place it in a buffer 2970 * @buf: The buffer to place the result into 2971 * @fmt: The format string to use 2972 * @...: Arguments for the format string 2973 * 2974 * The function returns the number of characters written 2975 * into @buf. Use snprintf() or scnprintf() in order to avoid 2976 * buffer overflows. 2977 * 2978 * See the vsnprintf() documentation for format string extensions over C99. 2979 */ 2980 int sprintf(char *buf, const char *fmt, ...) 2981 { 2982 va_list args; 2983 int i; 2984 2985 va_start(args, fmt); 2986 i = vsnprintf(buf, INT_MAX, fmt, args); 2987 va_end(args); 2988 2989 return i; 2990 } 2991 EXPORT_SYMBOL(sprintf); 2992 2993 #ifdef CONFIG_BINARY_PRINTF 2994 /* 2995 * bprintf service: 2996 * vbin_printf() - VA arguments to binary data 2997 * bstr_printf() - Binary data to text string 2998 */ 2999 3000 /** 3001 * vbin_printf - Parse a format string and place args' binary value in a buffer 3002 * @bin_buf: The buffer to place args' binary value 3003 * @size: The size of the buffer(by words(32bits), not characters) 3004 * @fmt: The format string to use 3005 * @args: Arguments for the format string 3006 * 3007 * The format follows C99 vsnprintf, except %n is ignored, and its argument 3008 * is skipped. 3009 * 3010 * The return value is the number of words(32bits) which would be generated for 3011 * the given input. 3012 * 3013 * NOTE: 3014 * If the return value is greater than @size, the resulting bin_buf is NOT 3015 * valid for bstr_printf(). 3016 */ 3017 int vbin_printf(u32 *bin_buf, size_t size, const char *fmt, va_list args) 3018 { 3019 struct printf_spec spec = {0}; 3020 char *str, *end; 3021 int width; 3022 3023 str = (char *)bin_buf; 3024 end = (char *)(bin_buf + size); 3025 3026 #define save_arg(type) \ 3027 ({ \ 3028 unsigned long long value; \ 3029 if (sizeof(type) == 8) { \ 3030 unsigned long long val8; \ 3031 str = PTR_ALIGN(str, sizeof(u32)); \ 3032 val8 = va_arg(args, unsigned long long); \ 3033 if (str + sizeof(type) <= end) { \ 3034 *(u32 *)str = *(u32 *)&val8; \ 3035 *(u32 *)(str + 4) = *((u32 *)&val8 + 1); \ 3036 } \ 3037 value = val8; \ 3038 } else { \ 3039 unsigned int val4; \ 3040 str = PTR_ALIGN(str, sizeof(type)); \ 3041 val4 = va_arg(args, int); \ 3042 if (str + sizeof(type) <= end) \ 3043 *(typeof(type) *)str = (type)(long)val4; \ 3044 value = (unsigned long long)val4; \ 3045 } \ 3046 str += sizeof(type); \ 3047 value; \ 3048 }) 3049 3050 while (*fmt) { 3051 int read = format_decode(fmt, &spec); 3052 3053 fmt += read; 3054 3055 switch (spec.type) { 3056 case FORMAT_TYPE_NONE: 3057 case FORMAT_TYPE_PERCENT_CHAR: 3058 break; 3059 case FORMAT_TYPE_INVALID: 3060 goto out; 3061 3062 case FORMAT_TYPE_WIDTH: 3063 case FORMAT_TYPE_PRECISION: 3064 width = (int)save_arg(int); 3065 /* Pointers may require the width */ 3066 if (*fmt == 'p') 3067 set_field_width(&spec, width); 3068 break; 3069 3070 case FORMAT_TYPE_CHAR: 3071 save_arg(char); 3072 break; 3073 3074 case FORMAT_TYPE_STR: { 3075 const char *save_str = va_arg(args, char *); 3076 const char *err_msg; 3077 size_t len; 3078 3079 err_msg = check_pointer_msg(save_str); 3080 if (err_msg) 3081 save_str = err_msg; 3082 3083 len = strlen(save_str) + 1; 3084 if (str + len < end) 3085 memcpy(str, save_str, len); 3086 str += len; 3087 break; 3088 } 3089 3090 case FORMAT_TYPE_PTR: 3091 /* Dereferenced pointers must be done now */ 3092 switch (*fmt) { 3093 /* Dereference of functions is still OK */ 3094 case 'S': 3095 case 's': 3096 case 'x': 3097 case 'K': 3098 case 'e': 3099 save_arg(void *); 3100 break; 3101 default: 3102 if (!isalnum(*fmt)) { 3103 save_arg(void *); 3104 break; 3105 } 3106 str = pointer(fmt, str, end, va_arg(args, void *), 3107 spec); 3108 if (str + 1 < end) 3109 *str++ = '\0'; 3110 else 3111 end[-1] = '\0'; /* Must be nul terminated */ 3112 } 3113 /* skip all alphanumeric pointer suffixes */ 3114 while (isalnum(*fmt)) 3115 fmt++; 3116 break; 3117 3118 default: 3119 switch (spec.type) { 3120 3121 case FORMAT_TYPE_LONG_LONG: 3122 save_arg(long long); 3123 break; 3124 case FORMAT_TYPE_ULONG: 3125 case FORMAT_TYPE_LONG: 3126 save_arg(unsigned long); 3127 break; 3128 case FORMAT_TYPE_SIZE_T: 3129 save_arg(size_t); 3130 break; 3131 case FORMAT_TYPE_PTRDIFF: 3132 save_arg(ptrdiff_t); 3133 break; 3134 case FORMAT_TYPE_UBYTE: 3135 case FORMAT_TYPE_BYTE: 3136 save_arg(char); 3137 break; 3138 case FORMAT_TYPE_USHORT: 3139 case FORMAT_TYPE_SHORT: 3140 save_arg(short); 3141 break; 3142 default: 3143 save_arg(int); 3144 } 3145 } 3146 } 3147 3148 out: 3149 return (u32 *)(PTR_ALIGN(str, sizeof(u32))) - bin_buf; 3150 #undef save_arg 3151 } 3152 EXPORT_SYMBOL_GPL(vbin_printf); 3153 3154 /** 3155 * bstr_printf - Format a string from binary arguments and place it in a buffer 3156 * @buf: The buffer to place the result into 3157 * @size: The size of the buffer, including the trailing null space 3158 * @fmt: The format string to use 3159 * @bin_buf: Binary arguments for the format string 3160 * 3161 * This function like C99 vsnprintf, but the difference is that vsnprintf gets 3162 * arguments from stack, and bstr_printf gets arguments from @bin_buf which is 3163 * a binary buffer that generated by vbin_printf. 3164 * 3165 * The format follows C99 vsnprintf, but has some extensions: 3166 * see vsnprintf comment for details. 3167 * 3168 * The return value is the number of characters which would 3169 * be generated for the given input, excluding the trailing 3170 * '\0', as per ISO C99. If you want to have the exact 3171 * number of characters written into @buf as return value 3172 * (not including the trailing '\0'), use vscnprintf(). If the 3173 * return is greater than or equal to @size, the resulting 3174 * string is truncated. 3175 */ 3176 int bstr_printf(char *buf, size_t size, const char *fmt, const u32 *bin_buf) 3177 { 3178 struct printf_spec spec = {0}; 3179 char *str, *end; 3180 const char *args = (const char *)bin_buf; 3181 3182 if (WARN_ON_ONCE(size > INT_MAX)) 3183 return 0; 3184 3185 str = buf; 3186 end = buf + size; 3187 3188 #define get_arg(type) \ 3189 ({ \ 3190 typeof(type) value; \ 3191 if (sizeof(type) == 8) { \ 3192 args = PTR_ALIGN(args, sizeof(u32)); \ 3193 *(u32 *)&value = *(u32 *)args; \ 3194 *((u32 *)&value + 1) = *(u32 *)(args + 4); \ 3195 } else { \ 3196 args = PTR_ALIGN(args, sizeof(type)); \ 3197 value = *(typeof(type) *)args; \ 3198 } \ 3199 args += sizeof(type); \ 3200 value; \ 3201 }) 3202 3203 /* Make sure end is always >= buf */ 3204 if (end < buf) { 3205 end = ((void *)-1); 3206 size = end - buf; 3207 } 3208 3209 while (*fmt) { 3210 const char *old_fmt = fmt; 3211 int read = format_decode(fmt, &spec); 3212 3213 fmt += read; 3214 3215 switch (spec.type) { 3216 case FORMAT_TYPE_NONE: { 3217 int copy = read; 3218 if (str < end) { 3219 if (copy > end - str) 3220 copy = end - str; 3221 memcpy(str, old_fmt, copy); 3222 } 3223 str += read; 3224 break; 3225 } 3226 3227 case FORMAT_TYPE_WIDTH: 3228 set_field_width(&spec, get_arg(int)); 3229 break; 3230 3231 case FORMAT_TYPE_PRECISION: 3232 set_precision(&spec, get_arg(int)); 3233 break; 3234 3235 case FORMAT_TYPE_CHAR: { 3236 char c; 3237 3238 if (!(spec.flags & LEFT)) { 3239 while (--spec.field_width > 0) { 3240 if (str < end) 3241 *str = ' '; 3242 ++str; 3243 } 3244 } 3245 c = (unsigned char) get_arg(char); 3246 if (str < end) 3247 *str = c; 3248 ++str; 3249 while (--spec.field_width > 0) { 3250 if (str < end) 3251 *str = ' '; 3252 ++str; 3253 } 3254 break; 3255 } 3256 3257 case FORMAT_TYPE_STR: { 3258 const char *str_arg = args; 3259 args += strlen(str_arg) + 1; 3260 str = string(str, end, (char *)str_arg, spec); 3261 break; 3262 } 3263 3264 case FORMAT_TYPE_PTR: { 3265 bool process = false; 3266 int copy, len; 3267 /* Non function dereferences were already done */ 3268 switch (*fmt) { 3269 case 'S': 3270 case 's': 3271 case 'x': 3272 case 'K': 3273 case 'e': 3274 process = true; 3275 break; 3276 default: 3277 if (!isalnum(*fmt)) { 3278 process = true; 3279 break; 3280 } 3281 /* Pointer dereference was already processed */ 3282 if (str < end) { 3283 len = copy = strlen(args); 3284 if (copy > end - str) 3285 copy = end - str; 3286 memcpy(str, args, copy); 3287 str += len; 3288 args += len + 1; 3289 } 3290 } 3291 if (process) 3292 str = pointer(fmt, str, end, get_arg(void *), spec); 3293 3294 while (isalnum(*fmt)) 3295 fmt++; 3296 break; 3297 } 3298 3299 case FORMAT_TYPE_PERCENT_CHAR: 3300 if (str < end) 3301 *str = '%'; 3302 ++str; 3303 break; 3304 3305 case FORMAT_TYPE_INVALID: 3306 goto out; 3307 3308 default: { 3309 unsigned long long num; 3310 3311 switch (spec.type) { 3312 3313 case FORMAT_TYPE_LONG_LONG: 3314 num = get_arg(long long); 3315 break; 3316 case FORMAT_TYPE_ULONG: 3317 case FORMAT_TYPE_LONG: 3318 num = get_arg(unsigned long); 3319 break; 3320 case FORMAT_TYPE_SIZE_T: 3321 num = get_arg(size_t); 3322 break; 3323 case FORMAT_TYPE_PTRDIFF: 3324 num = get_arg(ptrdiff_t); 3325 break; 3326 case FORMAT_TYPE_UBYTE: 3327 num = get_arg(unsigned char); 3328 break; 3329 case FORMAT_TYPE_BYTE: 3330 num = get_arg(signed char); 3331 break; 3332 case FORMAT_TYPE_USHORT: 3333 num = get_arg(unsigned short); 3334 break; 3335 case FORMAT_TYPE_SHORT: 3336 num = get_arg(short); 3337 break; 3338 case FORMAT_TYPE_UINT: 3339 num = get_arg(unsigned int); 3340 break; 3341 default: 3342 num = get_arg(int); 3343 } 3344 3345 str = number(str, end, num, spec); 3346 } /* default: */ 3347 } /* switch(spec.type) */ 3348 } /* while(*fmt) */ 3349 3350 out: 3351 if (size > 0) { 3352 if (str < end) 3353 *str = '\0'; 3354 else 3355 end[-1] = '\0'; 3356 } 3357 3358 #undef get_arg 3359 3360 /* the trailing null byte doesn't count towards the total */ 3361 return str - buf; 3362 } 3363 EXPORT_SYMBOL_GPL(bstr_printf); 3364 3365 /** 3366 * bprintf - Parse a format string and place args' binary value in a buffer 3367 * @bin_buf: The buffer to place args' binary value 3368 * @size: The size of the buffer(by words(32bits), not characters) 3369 * @fmt: The format string to use 3370 * @...: Arguments for the format string 3371 * 3372 * The function returns the number of words(u32) written 3373 * into @bin_buf. 3374 */ 3375 int bprintf(u32 *bin_buf, size_t size, const char *fmt, ...) 3376 { 3377 va_list args; 3378 int ret; 3379 3380 va_start(args, fmt); 3381 ret = vbin_printf(bin_buf, size, fmt, args); 3382 va_end(args); 3383 3384 return ret; 3385 } 3386 EXPORT_SYMBOL_GPL(bprintf); 3387 3388 #endif /* CONFIG_BINARY_PRINTF */ 3389 3390 /** 3391 * vsscanf - Unformat a buffer into a list of arguments 3392 * @buf: input buffer 3393 * @fmt: format of buffer 3394 * @args: arguments 3395 */ 3396 int vsscanf(const char *buf, const char *fmt, va_list args) 3397 { 3398 const char *str = buf; 3399 char *next; 3400 char digit; 3401 int num = 0; 3402 u8 qualifier; 3403 unsigned int base; 3404 union { 3405 long long s; 3406 unsigned long long u; 3407 } val; 3408 s16 field_width; 3409 bool is_sign; 3410 3411 while (*fmt) { 3412 /* skip any white space in format */ 3413 /* white space in format matches any amount of 3414 * white space, including none, in the input. 3415 */ 3416 if (isspace(*fmt)) { 3417 fmt = skip_spaces(++fmt); 3418 str = skip_spaces(str); 3419 } 3420 3421 /* anything that is not a conversion must match exactly */ 3422 if (*fmt != '%' && *fmt) { 3423 if (*fmt++ != *str++) 3424 break; 3425 continue; 3426 } 3427 3428 if (!*fmt) 3429 break; 3430 ++fmt; 3431 3432 /* skip this conversion. 3433 * advance both strings to next white space 3434 */ 3435 if (*fmt == '*') { 3436 if (!*str) 3437 break; 3438 while (!isspace(*fmt) && *fmt != '%' && *fmt) { 3439 /* '%*[' not yet supported, invalid format */ 3440 if (*fmt == '[') 3441 return num; 3442 fmt++; 3443 } 3444 while (!isspace(*str) && *str) 3445 str++; 3446 continue; 3447 } 3448 3449 /* get field width */ 3450 field_width = -1; 3451 if (isdigit(*fmt)) { 3452 field_width = skip_atoi(&fmt); 3453 if (field_width <= 0) 3454 break; 3455 } 3456 3457 /* get conversion qualifier */ 3458 qualifier = -1; 3459 if (*fmt == 'h' || _tolower(*fmt) == 'l' || 3460 *fmt == 'z') { 3461 qualifier = *fmt++; 3462 if (unlikely(qualifier == *fmt)) { 3463 if (qualifier == 'h') { 3464 qualifier = 'H'; 3465 fmt++; 3466 } else if (qualifier == 'l') { 3467 qualifier = 'L'; 3468 fmt++; 3469 } 3470 } 3471 } 3472 3473 if (!*fmt) 3474 break; 3475 3476 if (*fmt == 'n') { 3477 /* return number of characters read so far */ 3478 *va_arg(args, int *) = str - buf; 3479 ++fmt; 3480 continue; 3481 } 3482 3483 if (!*str) 3484 break; 3485 3486 base = 10; 3487 is_sign = false; 3488 3489 switch (*fmt++) { 3490 case 'c': 3491 { 3492 char *s = (char *)va_arg(args, char*); 3493 if (field_width == -1) 3494 field_width = 1; 3495 do { 3496 *s++ = *str++; 3497 } while (--field_width > 0 && *str); 3498 num++; 3499 } 3500 continue; 3501 case 's': 3502 { 3503 char *s = (char *)va_arg(args, char *); 3504 if (field_width == -1) 3505 field_width = SHRT_MAX; 3506 /* first, skip leading white space in buffer */ 3507 str = skip_spaces(str); 3508 3509 /* now copy until next white space */ 3510 while (*str && !isspace(*str) && field_width--) 3511 *s++ = *str++; 3512 *s = '\0'; 3513 num++; 3514 } 3515 continue; 3516 /* 3517 * Warning: This implementation of the '[' conversion specifier 3518 * deviates from its glibc counterpart in the following ways: 3519 * (1) It does NOT support ranges i.e. '-' is NOT a special 3520 * character 3521 * (2) It cannot match the closing bracket ']' itself 3522 * (3) A field width is required 3523 * (4) '%*[' (discard matching input) is currently not supported 3524 * 3525 * Example usage: 3526 * ret = sscanf("00:0a:95","%2[^:]:%2[^:]:%2[^:]", 3527 * buf1, buf2, buf3); 3528 * if (ret < 3) 3529 * // etc.. 3530 */ 3531 case '[': 3532 { 3533 char *s = (char *)va_arg(args, char *); 3534 DECLARE_BITMAP(set, 256) = {0}; 3535 unsigned int len = 0; 3536 bool negate = (*fmt == '^'); 3537 3538 /* field width is required */ 3539 if (field_width == -1) 3540 return num; 3541 3542 if (negate) 3543 ++fmt; 3544 3545 for ( ; *fmt && *fmt != ']'; ++fmt, ++len) 3546 __set_bit((u8)*fmt, set); 3547 3548 /* no ']' or no character set found */ 3549 if (!*fmt || !len) 3550 return num; 3551 ++fmt; 3552 3553 if (negate) { 3554 bitmap_complement(set, set, 256); 3555 /* exclude null '\0' byte */ 3556 __clear_bit(0, set); 3557 } 3558 3559 /* match must be non-empty */ 3560 if (!test_bit((u8)*str, set)) 3561 return num; 3562 3563 while (test_bit((u8)*str, set) && field_width--) 3564 *s++ = *str++; 3565 *s = '\0'; 3566 ++num; 3567 } 3568 continue; 3569 case 'o': 3570 base = 8; 3571 break; 3572 case 'x': 3573 case 'X': 3574 base = 16; 3575 break; 3576 case 'i': 3577 base = 0; 3578 fallthrough; 3579 case 'd': 3580 is_sign = true; 3581 fallthrough; 3582 case 'u': 3583 break; 3584 case '%': 3585 /* looking for '%' in str */ 3586 if (*str++ != '%') 3587 return num; 3588 continue; 3589 default: 3590 /* invalid format; stop here */ 3591 return num; 3592 } 3593 3594 /* have some sort of integer conversion. 3595 * first, skip white space in buffer. 3596 */ 3597 str = skip_spaces(str); 3598 3599 digit = *str; 3600 if (is_sign && digit == '-') { 3601 if (field_width == 1) 3602 break; 3603 3604 digit = *(str + 1); 3605 } 3606 3607 if (!digit 3608 || (base == 16 && !isxdigit(digit)) 3609 || (base == 10 && !isdigit(digit)) 3610 || (base == 8 && (!isdigit(digit) || digit > '7')) 3611 || (base == 0 && !isdigit(digit))) 3612 break; 3613 3614 if (is_sign) 3615 val.s = simple_strntoll(str, 3616 field_width >= 0 ? field_width : INT_MAX, 3617 &next, base); 3618 else 3619 val.u = simple_strntoull(str, 3620 field_width >= 0 ? field_width : INT_MAX, 3621 &next, base); 3622 3623 switch (qualifier) { 3624 case 'H': /* that's 'hh' in format */ 3625 if (is_sign) 3626 *va_arg(args, signed char *) = val.s; 3627 else 3628 *va_arg(args, unsigned char *) = val.u; 3629 break; 3630 case 'h': 3631 if (is_sign) 3632 *va_arg(args, short *) = val.s; 3633 else 3634 *va_arg(args, unsigned short *) = val.u; 3635 break; 3636 case 'l': 3637 if (is_sign) 3638 *va_arg(args, long *) = val.s; 3639 else 3640 *va_arg(args, unsigned long *) = val.u; 3641 break; 3642 case 'L': 3643 if (is_sign) 3644 *va_arg(args, long long *) = val.s; 3645 else 3646 *va_arg(args, unsigned long long *) = val.u; 3647 break; 3648 case 'z': 3649 *va_arg(args, size_t *) = val.u; 3650 break; 3651 default: 3652 if (is_sign) 3653 *va_arg(args, int *) = val.s; 3654 else 3655 *va_arg(args, unsigned int *) = val.u; 3656 break; 3657 } 3658 num++; 3659 3660 if (!next) 3661 break; 3662 str = next; 3663 } 3664 3665 return num; 3666 } 3667 EXPORT_SYMBOL(vsscanf); 3668 3669 /** 3670 * sscanf - Unformat a buffer into a list of arguments 3671 * @buf: input buffer 3672 * @fmt: formatting of buffer 3673 * @...: resulting arguments 3674 */ 3675 int sscanf(const char *buf, const char *fmt, ...) 3676 { 3677 va_list args; 3678 int i; 3679 3680 va_start(args, fmt); 3681 i = vsscanf(buf, fmt, args); 3682 va_end(args); 3683 3684 return i; 3685 } 3686 EXPORT_SYMBOL(sscanf); 3687