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 <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 53 #include <linux/string_helpers.h> 54 #include "kstrtox.h" 55 56 static unsigned long long simple_strntoull(const char *startp, size_t max_chars, 57 char **endp, unsigned int base) 58 { 59 const char *cp; 60 unsigned long long result = 0ULL; 61 size_t prefix_chars; 62 unsigned int rv; 63 64 cp = _parse_integer_fixup_radix(startp, &base); 65 prefix_chars = cp - startp; 66 if (prefix_chars < max_chars) { 67 rv = _parse_integer_limit(cp, base, &result, max_chars - prefix_chars); 68 /* FIXME */ 69 cp += (rv & ~KSTRTOX_OVERFLOW); 70 } else { 71 /* Field too short for prefix + digit, skip over without converting */ 72 cp = startp + max_chars; 73 } 74 75 if (endp) 76 *endp = (char *)cp; 77 78 return result; 79 } 80 81 /** 82 * simple_strtoull - convert a string to an unsigned long long 83 * @cp: The start of the string 84 * @endp: A pointer to the end of the parsed string will be placed here 85 * @base: The number base to use 86 * 87 * This function has caveats. Please use kstrtoull instead. 88 */ 89 unsigned long long simple_strtoull(const char *cp, char **endp, unsigned int base) 90 { 91 return simple_strntoull(cp, INT_MAX, endp, base); 92 } 93 EXPORT_SYMBOL(simple_strtoull); 94 95 /** 96 * simple_strtoul - convert a string to an unsigned long 97 * @cp: The start of the string 98 * @endp: A pointer to the end of the parsed string will be placed here 99 * @base: The number base to use 100 * 101 * This function has caveats. Please use kstrtoul instead. 102 */ 103 unsigned long simple_strtoul(const char *cp, char **endp, unsigned int base) 104 { 105 return simple_strtoull(cp, endp, base); 106 } 107 EXPORT_SYMBOL(simple_strtoul); 108 109 /** 110 * simple_strtol - convert a string to a signed long 111 * @cp: The start of the string 112 * @endp: A pointer to the end of the parsed string will be placed here 113 * @base: The number base to use 114 * 115 * This function has caveats. Please use kstrtol instead. 116 */ 117 long simple_strtol(const char *cp, char **endp, unsigned int base) 118 { 119 if (*cp == '-') 120 return -simple_strtoul(cp + 1, endp, base); 121 122 return simple_strtoul(cp, endp, base); 123 } 124 EXPORT_SYMBOL(simple_strtol); 125 126 static long long simple_strntoll(const char *cp, size_t max_chars, char **endp, 127 unsigned int base) 128 { 129 /* 130 * simple_strntoull() safely handles receiving max_chars==0 in the 131 * case cp[0] == '-' && max_chars == 1. 132 * If max_chars == 0 we can drop through and pass it to simple_strntoull() 133 * and the content of *cp is irrelevant. 134 */ 135 if (*cp == '-' && max_chars > 0) 136 return -simple_strntoull(cp + 1, max_chars - 1, endp, base); 137 138 return simple_strntoull(cp, max_chars, endp, base); 139 } 140 141 /** 142 * simple_strtoll - convert a string to a signed long long 143 * @cp: The start of the string 144 * @endp: A pointer to the end of the parsed string will be placed here 145 * @base: The number base to use 146 * 147 * This function has caveats. Please use kstrtoll instead. 148 */ 149 long long simple_strtoll(const char *cp, char **endp, unsigned int base) 150 { 151 return simple_strntoll(cp, INT_MAX, endp, base); 152 } 153 EXPORT_SYMBOL(simple_strtoll); 154 155 static noinline_for_stack 156 int skip_atoi(const char **s) 157 { 158 int i = 0; 159 160 do { 161 i = i*10 + *((*s)++) - '0'; 162 } while (isdigit(**s)); 163 164 return i; 165 } 166 167 /* 168 * Decimal conversion is by far the most typical, and is used for 169 * /proc and /sys data. This directly impacts e.g. top performance 170 * with many processes running. We optimize it for speed by emitting 171 * two characters at a time, using a 200 byte lookup table. This 172 * roughly halves the number of multiplications compared to computing 173 * the digits one at a time. Implementation strongly inspired by the 174 * previous version, which in turn used ideas described at 175 * <http://www.cs.uiowa.edu/~jones/bcd/divide.html> (with permission 176 * from the author, Douglas W. Jones). 177 * 178 * It turns out there is precisely one 26 bit fixed-point 179 * approximation a of 64/100 for which x/100 == (x * (u64)a) >> 32 180 * holds for all x in [0, 10^8-1], namely a = 0x28f5c29. The actual 181 * range happens to be somewhat larger (x <= 1073741898), but that's 182 * irrelevant for our purpose. 183 * 184 * For dividing a number in the range [10^4, 10^6-1] by 100, we still 185 * need a 32x32->64 bit multiply, so we simply use the same constant. 186 * 187 * For dividing a number in the range [100, 10^4-1] by 100, there are 188 * several options. The simplest is (x * 0x147b) >> 19, which is valid 189 * for all x <= 43698. 190 */ 191 192 static const u16 decpair[100] = { 193 #define _(x) (__force u16) cpu_to_le16(((x % 10) | ((x / 10) << 8)) + 0x3030) 194 _( 0), _( 1), _( 2), _( 3), _( 4), _( 5), _( 6), _( 7), _( 8), _( 9), 195 _(10), _(11), _(12), _(13), _(14), _(15), _(16), _(17), _(18), _(19), 196 _(20), _(21), _(22), _(23), _(24), _(25), _(26), _(27), _(28), _(29), 197 _(30), _(31), _(32), _(33), _(34), _(35), _(36), _(37), _(38), _(39), 198 _(40), _(41), _(42), _(43), _(44), _(45), _(46), _(47), _(48), _(49), 199 _(50), _(51), _(52), _(53), _(54), _(55), _(56), _(57), _(58), _(59), 200 _(60), _(61), _(62), _(63), _(64), _(65), _(66), _(67), _(68), _(69), 201 _(70), _(71), _(72), _(73), _(74), _(75), _(76), _(77), _(78), _(79), 202 _(80), _(81), _(82), _(83), _(84), _(85), _(86), _(87), _(88), _(89), 203 _(90), _(91), _(92), _(93), _(94), _(95), _(96), _(97), _(98), _(99), 204 #undef _ 205 }; 206 207 /* 208 * This will print a single '0' even if r == 0, since we would 209 * immediately jump to out_r where two 0s would be written but only 210 * one of them accounted for in buf. This is needed by ip4_string 211 * below. All other callers pass a non-zero value of r. 212 */ 213 static noinline_for_stack 214 char *put_dec_trunc8(char *buf, unsigned r) 215 { 216 unsigned q; 217 218 /* 1 <= r < 10^8 */ 219 if (r < 100) 220 goto out_r; 221 222 /* 100 <= r < 10^8 */ 223 q = (r * (u64)0x28f5c29) >> 32; 224 *((u16 *)buf) = decpair[r - 100*q]; 225 buf += 2; 226 227 /* 1 <= q < 10^6 */ 228 if (q < 100) 229 goto out_q; 230 231 /* 100 <= q < 10^6 */ 232 r = (q * (u64)0x28f5c29) >> 32; 233 *((u16 *)buf) = decpair[q - 100*r]; 234 buf += 2; 235 236 /* 1 <= r < 10^4 */ 237 if (r < 100) 238 goto out_r; 239 240 /* 100 <= r < 10^4 */ 241 q = (r * 0x147b) >> 19; 242 *((u16 *)buf) = decpair[r - 100*q]; 243 buf += 2; 244 out_q: 245 /* 1 <= q < 100 */ 246 r = q; 247 out_r: 248 /* 1 <= r < 100 */ 249 *((u16 *)buf) = decpair[r]; 250 buf += r < 10 ? 1 : 2; 251 return buf; 252 } 253 254 #if BITS_PER_LONG == 64 && BITS_PER_LONG_LONG == 64 255 static noinline_for_stack 256 char *put_dec_full8(char *buf, unsigned r) 257 { 258 unsigned q; 259 260 /* 0 <= r < 10^8 */ 261 q = (r * (u64)0x28f5c29) >> 32; 262 *((u16 *)buf) = decpair[r - 100*q]; 263 buf += 2; 264 265 /* 0 <= q < 10^6 */ 266 r = (q * (u64)0x28f5c29) >> 32; 267 *((u16 *)buf) = decpair[q - 100*r]; 268 buf += 2; 269 270 /* 0 <= r < 10^4 */ 271 q = (r * 0x147b) >> 19; 272 *((u16 *)buf) = decpair[r - 100*q]; 273 buf += 2; 274 275 /* 0 <= q < 100 */ 276 *((u16 *)buf) = decpair[q]; 277 buf += 2; 278 return buf; 279 } 280 281 static noinline_for_stack 282 char *put_dec(char *buf, unsigned long long n) 283 { 284 if (n >= 100*1000*1000) 285 buf = put_dec_full8(buf, do_div(n, 100*1000*1000)); 286 /* 1 <= n <= 1.6e11 */ 287 if (n >= 100*1000*1000) 288 buf = put_dec_full8(buf, do_div(n, 100*1000*1000)); 289 /* 1 <= n < 1e8 */ 290 return put_dec_trunc8(buf, n); 291 } 292 293 #elif BITS_PER_LONG == 32 && BITS_PER_LONG_LONG == 64 294 295 static void 296 put_dec_full4(char *buf, unsigned r) 297 { 298 unsigned q; 299 300 /* 0 <= r < 10^4 */ 301 q = (r * 0x147b) >> 19; 302 *((u16 *)buf) = decpair[r - 100*q]; 303 buf += 2; 304 /* 0 <= q < 100 */ 305 *((u16 *)buf) = decpair[q]; 306 } 307 308 /* 309 * Call put_dec_full4 on x % 10000, return x / 10000. 310 * The approximation x/10000 == (x * 0x346DC5D7) >> 43 311 * holds for all x < 1,128,869,999. The largest value this 312 * helper will ever be asked to convert is 1,125,520,955. 313 * (second call in the put_dec code, assuming n is all-ones). 314 */ 315 static noinline_for_stack 316 unsigned put_dec_helper4(char *buf, unsigned x) 317 { 318 uint32_t q = (x * (uint64_t)0x346DC5D7) >> 43; 319 320 put_dec_full4(buf, x - q * 10000); 321 return q; 322 } 323 324 /* Based on code by Douglas W. Jones found at 325 * <http://www.cs.uiowa.edu/~jones/bcd/decimal.html#sixtyfour> 326 * (with permission from the author). 327 * Performs no 64-bit division and hence should be fast on 32-bit machines. 328 */ 329 static 330 char *put_dec(char *buf, unsigned long long n) 331 { 332 uint32_t d3, d2, d1, q, h; 333 334 if (n < 100*1000*1000) 335 return put_dec_trunc8(buf, n); 336 337 d1 = ((uint32_t)n >> 16); /* implicit "& 0xffff" */ 338 h = (n >> 32); 339 d2 = (h ) & 0xffff; 340 d3 = (h >> 16); /* implicit "& 0xffff" */ 341 342 /* n = 2^48 d3 + 2^32 d2 + 2^16 d1 + d0 343 = 281_4749_7671_0656 d3 + 42_9496_7296 d2 + 6_5536 d1 + d0 */ 344 q = 656 * d3 + 7296 * d2 + 5536 * d1 + ((uint32_t)n & 0xffff); 345 q = put_dec_helper4(buf, q); 346 347 q += 7671 * d3 + 9496 * d2 + 6 * d1; 348 q = put_dec_helper4(buf+4, q); 349 350 q += 4749 * d3 + 42 * d2; 351 q = put_dec_helper4(buf+8, q); 352 353 q += 281 * d3; 354 buf += 12; 355 if (q) 356 buf = put_dec_trunc8(buf, q); 357 else while (buf[-1] == '0') 358 --buf; 359 360 return buf; 361 } 362 363 #endif 364 365 /* 366 * Convert passed number to decimal string. 367 * Returns the length of string. On buffer overflow, returns 0. 368 * 369 * If speed is not important, use snprintf(). It's easy to read the code. 370 */ 371 int num_to_str(char *buf, int size, unsigned long long num, unsigned int width) 372 { 373 /* put_dec requires 2-byte alignment of the buffer. */ 374 char tmp[sizeof(num) * 3] __aligned(2); 375 int idx, len; 376 377 /* put_dec() may work incorrectly for num = 0 (generate "", not "0") */ 378 if (num <= 9) { 379 tmp[0] = '0' + num; 380 len = 1; 381 } else { 382 len = put_dec(tmp, num) - tmp; 383 } 384 385 if (len > size || width > size) 386 return 0; 387 388 if (width > len) { 389 width = width - len; 390 for (idx = 0; idx < width; idx++) 391 buf[idx] = ' '; 392 } else { 393 width = 0; 394 } 395 396 for (idx = 0; idx < len; ++idx) 397 buf[idx + width] = tmp[len - idx - 1]; 398 399 return len + width; 400 } 401 402 #define SIGN 1 /* unsigned/signed, must be 1 */ 403 #define LEFT 2 /* left justified */ 404 #define PLUS 4 /* show plus */ 405 #define SPACE 8 /* space if plus */ 406 #define ZEROPAD 16 /* pad with zero, must be 16 == '0' - ' ' */ 407 #define SMALL 32 /* use lowercase in hex (must be 32 == 0x20) */ 408 #define SPECIAL 64 /* prefix hex with "0x", octal with "0" */ 409 410 static_assert(ZEROPAD == ('0' - ' ')); 411 static_assert(SMALL == ' '); 412 413 enum format_type { 414 FORMAT_TYPE_NONE, /* Just a string part */ 415 FORMAT_TYPE_WIDTH, 416 FORMAT_TYPE_PRECISION, 417 FORMAT_TYPE_CHAR, 418 FORMAT_TYPE_STR, 419 FORMAT_TYPE_PTR, 420 FORMAT_TYPE_PERCENT_CHAR, 421 FORMAT_TYPE_INVALID, 422 FORMAT_TYPE_LONG_LONG, 423 FORMAT_TYPE_ULONG, 424 FORMAT_TYPE_LONG, 425 FORMAT_TYPE_UBYTE, 426 FORMAT_TYPE_BYTE, 427 FORMAT_TYPE_USHORT, 428 FORMAT_TYPE_SHORT, 429 FORMAT_TYPE_UINT, 430 FORMAT_TYPE_INT, 431 FORMAT_TYPE_SIZE_T, 432 FORMAT_TYPE_PTRDIFF 433 }; 434 435 struct printf_spec { 436 unsigned int type:8; /* format_type enum */ 437 signed int field_width:24; /* width of output field */ 438 unsigned int flags:8; /* flags to number() */ 439 unsigned int base:8; /* number base, 8, 10 or 16 only */ 440 signed int precision:16; /* # of digits/chars */ 441 } __packed; 442 static_assert(sizeof(struct printf_spec) == 8); 443 444 #define FIELD_WIDTH_MAX ((1 << 23) - 1) 445 #define PRECISION_MAX ((1 << 15) - 1) 446 447 static noinline_for_stack 448 char *number(char *buf, char *end, unsigned long long num, 449 struct printf_spec spec) 450 { 451 /* put_dec requires 2-byte alignment of the buffer. */ 452 char tmp[3 * sizeof(num)] __aligned(2); 453 char sign; 454 char locase; 455 int need_pfx = ((spec.flags & SPECIAL) && spec.base != 10); 456 int i; 457 bool is_zero = num == 0LL; 458 int field_width = spec.field_width; 459 int precision = spec.precision; 460 461 /* locase = 0 or 0x20. ORing digits or letters with 'locase' 462 * produces same digits or (maybe lowercased) letters */ 463 locase = (spec.flags & SMALL); 464 if (spec.flags & LEFT) 465 spec.flags &= ~ZEROPAD; 466 sign = 0; 467 if (spec.flags & SIGN) { 468 if ((signed long long)num < 0) { 469 sign = '-'; 470 num = -(signed long long)num; 471 field_width--; 472 } else if (spec.flags & PLUS) { 473 sign = '+'; 474 field_width--; 475 } else if (spec.flags & SPACE) { 476 sign = ' '; 477 field_width--; 478 } 479 } 480 if (need_pfx) { 481 if (spec.base == 16) 482 field_width -= 2; 483 else if (!is_zero) 484 field_width--; 485 } 486 487 /* generate full string in tmp[], in reverse order */ 488 i = 0; 489 if (num < spec.base) 490 tmp[i++] = hex_asc_upper[num] | locase; 491 else if (spec.base != 10) { /* 8 or 16 */ 492 int mask = spec.base - 1; 493 int shift = 3; 494 495 if (spec.base == 16) 496 shift = 4; 497 do { 498 tmp[i++] = (hex_asc_upper[((unsigned char)num) & mask] | locase); 499 num >>= shift; 500 } while (num); 501 } else { /* base 10 */ 502 i = put_dec(tmp, num) - tmp; 503 } 504 505 /* printing 100 using %2d gives "100", not "00" */ 506 if (i > precision) 507 precision = i; 508 /* leading space padding */ 509 field_width -= precision; 510 if (!(spec.flags & (ZEROPAD | LEFT))) { 511 while (--field_width >= 0) { 512 if (buf < end) 513 *buf = ' '; 514 ++buf; 515 } 516 } 517 /* sign */ 518 if (sign) { 519 if (buf < end) 520 *buf = sign; 521 ++buf; 522 } 523 /* "0x" / "0" prefix */ 524 if (need_pfx) { 525 if (spec.base == 16 || !is_zero) { 526 if (buf < end) 527 *buf = '0'; 528 ++buf; 529 } 530 if (spec.base == 16) { 531 if (buf < end) 532 *buf = ('X' | locase); 533 ++buf; 534 } 535 } 536 /* zero or space padding */ 537 if (!(spec.flags & LEFT)) { 538 char c = ' ' + (spec.flags & ZEROPAD); 539 540 while (--field_width >= 0) { 541 if (buf < end) 542 *buf = c; 543 ++buf; 544 } 545 } 546 /* hmm even more zero padding? */ 547 while (i <= --precision) { 548 if (buf < end) 549 *buf = '0'; 550 ++buf; 551 } 552 /* actual digits of result */ 553 while (--i >= 0) { 554 if (buf < end) 555 *buf = tmp[i]; 556 ++buf; 557 } 558 /* trailing space padding */ 559 while (--field_width >= 0) { 560 if (buf < end) 561 *buf = ' '; 562 ++buf; 563 } 564 565 return buf; 566 } 567 568 static noinline_for_stack 569 char *special_hex_number(char *buf, char *end, unsigned long long num, int size) 570 { 571 struct printf_spec spec; 572 573 spec.type = FORMAT_TYPE_PTR; 574 spec.field_width = 2 + 2 * size; /* 0x + hex */ 575 spec.flags = SPECIAL | SMALL | ZEROPAD; 576 spec.base = 16; 577 spec.precision = -1; 578 579 return number(buf, end, num, spec); 580 } 581 582 static void move_right(char *buf, char *end, unsigned len, unsigned spaces) 583 { 584 size_t size; 585 if (buf >= end) /* nowhere to put anything */ 586 return; 587 size = end - buf; 588 if (size <= spaces) { 589 memset(buf, ' ', size); 590 return; 591 } 592 if (len) { 593 if (len > size - spaces) 594 len = size - spaces; 595 memmove(buf + spaces, buf, len); 596 } 597 memset(buf, ' ', spaces); 598 } 599 600 /* 601 * Handle field width padding for a string. 602 * @buf: current buffer position 603 * @n: length of string 604 * @end: end of output buffer 605 * @spec: for field width and flags 606 * Returns: new buffer position after padding. 607 */ 608 static noinline_for_stack 609 char *widen_string(char *buf, int n, char *end, struct printf_spec spec) 610 { 611 unsigned spaces; 612 613 if (likely(n >= spec.field_width)) 614 return buf; 615 /* we want to pad the sucker */ 616 spaces = spec.field_width - n; 617 if (!(spec.flags & LEFT)) { 618 move_right(buf - n, end, n, spaces); 619 return buf + spaces; 620 } 621 while (spaces--) { 622 if (buf < end) 623 *buf = ' '; 624 ++buf; 625 } 626 return buf; 627 } 628 629 /* Handle string from a well known address. */ 630 static char *string_nocheck(char *buf, char *end, const char *s, 631 struct printf_spec spec) 632 { 633 int len = 0; 634 int lim = spec.precision; 635 636 while (lim--) { 637 char c = *s++; 638 if (!c) 639 break; 640 if (buf < end) 641 *buf = c; 642 ++buf; 643 ++len; 644 } 645 return widen_string(buf, len, end, spec); 646 } 647 648 static char *err_ptr(char *buf, char *end, void *ptr, 649 struct printf_spec spec) 650 { 651 int err = PTR_ERR(ptr); 652 const char *sym = errname(err); 653 654 if (sym) 655 return string_nocheck(buf, end, sym, spec); 656 657 /* 658 * Somebody passed ERR_PTR(-1234) or some other non-existing 659 * Efoo - or perhaps CONFIG_SYMBOLIC_ERRNAME=n. Fall back to 660 * printing it as its decimal representation. 661 */ 662 spec.flags |= SIGN; 663 spec.base = 10; 664 return number(buf, end, err, spec); 665 } 666 667 /* Be careful: error messages must fit into the given buffer. */ 668 static char *error_string(char *buf, char *end, const char *s, 669 struct printf_spec spec) 670 { 671 /* 672 * Hard limit to avoid a completely insane messages. It actually 673 * works pretty well because most error messages are in 674 * the many pointer format modifiers. 675 */ 676 if (spec.precision == -1) 677 spec.precision = 2 * sizeof(void *); 678 679 return string_nocheck(buf, end, s, spec); 680 } 681 682 /* 683 * Do not call any complex external code here. Nested printk()/vsprintf() 684 * might cause infinite loops. Failures might break printk() and would 685 * be hard to debug. 686 */ 687 static const char *check_pointer_msg(const void *ptr) 688 { 689 if (!ptr) 690 return "(null)"; 691 692 if ((unsigned long)ptr < PAGE_SIZE || IS_ERR_VALUE(ptr)) 693 return "(efault)"; 694 695 return NULL; 696 } 697 698 static int check_pointer(char **buf, char *end, const void *ptr, 699 struct printf_spec spec) 700 { 701 const char *err_msg; 702 703 err_msg = check_pointer_msg(ptr); 704 if (err_msg) { 705 *buf = error_string(*buf, end, err_msg, spec); 706 return -EFAULT; 707 } 708 709 return 0; 710 } 711 712 static noinline_for_stack 713 char *string(char *buf, char *end, const char *s, 714 struct printf_spec spec) 715 { 716 if (check_pointer(&buf, end, s, spec)) 717 return buf; 718 719 return string_nocheck(buf, end, s, spec); 720 } 721 722 static char *pointer_string(char *buf, char *end, 723 const void *ptr, 724 struct printf_spec spec) 725 { 726 spec.base = 16; 727 spec.flags |= SMALL; 728 if (spec.field_width == -1) { 729 spec.field_width = 2 * sizeof(ptr); 730 spec.flags |= ZEROPAD; 731 } 732 733 return number(buf, end, (unsigned long int)ptr, spec); 734 } 735 736 /* Make pointers available for printing early in the boot sequence. */ 737 static int debug_boot_weak_hash __ro_after_init; 738 739 static int __init debug_boot_weak_hash_enable(char *str) 740 { 741 debug_boot_weak_hash = 1; 742 pr_info("debug_boot_weak_hash enabled\n"); 743 return 0; 744 } 745 early_param("debug_boot_weak_hash", debug_boot_weak_hash_enable); 746 747 static DEFINE_STATIC_KEY_TRUE(not_filled_random_ptr_key); 748 static siphash_key_t ptr_key __read_mostly; 749 750 static void enable_ptr_key_workfn(struct work_struct *work) 751 { 752 get_random_bytes(&ptr_key, sizeof(ptr_key)); 753 /* Needs to run from preemptible context */ 754 static_branch_disable(¬_filled_random_ptr_key); 755 } 756 757 static DECLARE_WORK(enable_ptr_key_work, enable_ptr_key_workfn); 758 759 static void fill_random_ptr_key(struct random_ready_callback *unused) 760 { 761 /* This may be in an interrupt handler. */ 762 queue_work(system_unbound_wq, &enable_ptr_key_work); 763 } 764 765 static struct random_ready_callback random_ready = { 766 .func = fill_random_ptr_key 767 }; 768 769 static int __init initialize_ptr_random(void) 770 { 771 int key_size = sizeof(ptr_key); 772 int ret; 773 774 /* Use hw RNG if available. */ 775 if (get_random_bytes_arch(&ptr_key, key_size) == key_size) { 776 static_branch_disable(¬_filled_random_ptr_key); 777 return 0; 778 } 779 780 ret = add_random_ready_callback(&random_ready); 781 if (!ret) { 782 return 0; 783 } else if (ret == -EALREADY) { 784 /* This is in preemptible context */ 785 enable_ptr_key_workfn(&enable_ptr_key_work); 786 return 0; 787 } 788 789 return ret; 790 } 791 early_initcall(initialize_ptr_random); 792 793 /* Maps a pointer to a 32 bit unique identifier. */ 794 static inline int __ptr_to_hashval(const void *ptr, unsigned long *hashval_out) 795 { 796 unsigned long hashval; 797 798 if (static_branch_unlikely(¬_filled_random_ptr_key)) 799 return -EAGAIN; 800 801 #ifdef CONFIG_64BIT 802 hashval = (unsigned long)siphash_1u64((u64)ptr, &ptr_key); 803 /* 804 * Mask off the first 32 bits, this makes explicit that we have 805 * modified the address (and 32 bits is plenty for a unique ID). 806 */ 807 hashval = hashval & 0xffffffff; 808 #else 809 hashval = (unsigned long)siphash_1u32((u32)ptr, &ptr_key); 810 #endif 811 *hashval_out = hashval; 812 return 0; 813 } 814 815 int ptr_to_hashval(const void *ptr, unsigned long *hashval_out) 816 { 817 return __ptr_to_hashval(ptr, hashval_out); 818 } 819 820 static char *ptr_to_id(char *buf, char *end, const void *ptr, 821 struct printf_spec spec) 822 { 823 const char *str = sizeof(ptr) == 8 ? "(____ptrval____)" : "(ptrval)"; 824 unsigned long hashval; 825 int ret; 826 827 /* 828 * Print the real pointer value for NULL and error pointers, 829 * as they are not actual addresses. 830 */ 831 if (IS_ERR_OR_NULL(ptr)) 832 return pointer_string(buf, end, ptr, spec); 833 834 /* When debugging early boot use non-cryptographically secure hash. */ 835 if (unlikely(debug_boot_weak_hash)) { 836 hashval = hash_long((unsigned long)ptr, 32); 837 return pointer_string(buf, end, (const void *)hashval, spec); 838 } 839 840 ret = __ptr_to_hashval(ptr, &hashval); 841 if (ret) { 842 spec.field_width = 2 * sizeof(ptr); 843 /* string length must be less than default_width */ 844 return error_string(buf, end, str, spec); 845 } 846 847 return pointer_string(buf, end, (const void *)hashval, spec); 848 } 849 850 int kptr_restrict __read_mostly; 851 852 static noinline_for_stack 853 char *restricted_pointer(char *buf, char *end, const void *ptr, 854 struct printf_spec spec) 855 { 856 switch (kptr_restrict) { 857 case 0: 858 /* Handle as %p, hash and do _not_ leak addresses. */ 859 return ptr_to_id(buf, end, ptr, spec); 860 case 1: { 861 const struct cred *cred; 862 863 /* 864 * kptr_restrict==1 cannot be used in IRQ context 865 * because its test for CAP_SYSLOG would be meaningless. 866 */ 867 if (in_irq() || in_serving_softirq() || in_nmi()) { 868 if (spec.field_width == -1) 869 spec.field_width = 2 * sizeof(ptr); 870 return error_string(buf, end, "pK-error", spec); 871 } 872 873 /* 874 * Only print the real pointer value if the current 875 * process has CAP_SYSLOG and is running with the 876 * same credentials it started with. This is because 877 * access to files is checked at open() time, but %pK 878 * checks permission at read() time. We don't want to 879 * leak pointer values if a binary opens a file using 880 * %pK and then elevates privileges before reading it. 881 */ 882 cred = current_cred(); 883 if (!has_capability_noaudit(current, CAP_SYSLOG) || 884 !uid_eq(cred->euid, cred->uid) || 885 !gid_eq(cred->egid, cred->gid)) 886 ptr = NULL; 887 break; 888 } 889 case 2: 890 default: 891 /* Always print 0's for %pK */ 892 ptr = NULL; 893 break; 894 } 895 896 return pointer_string(buf, end, ptr, spec); 897 } 898 899 static noinline_for_stack 900 char *dentry_name(char *buf, char *end, const struct dentry *d, struct printf_spec spec, 901 const char *fmt) 902 { 903 const char *array[4], *s; 904 const struct dentry *p; 905 int depth; 906 int i, n; 907 908 switch (fmt[1]) { 909 case '2': case '3': case '4': 910 depth = fmt[1] - '0'; 911 break; 912 default: 913 depth = 1; 914 } 915 916 rcu_read_lock(); 917 for (i = 0; i < depth; i++, d = p) { 918 if (check_pointer(&buf, end, d, spec)) { 919 rcu_read_unlock(); 920 return buf; 921 } 922 923 p = READ_ONCE(d->d_parent); 924 array[i] = READ_ONCE(d->d_name.name); 925 if (p == d) { 926 if (i) 927 array[i] = ""; 928 i++; 929 break; 930 } 931 } 932 s = array[--i]; 933 for (n = 0; n != spec.precision; n++, buf++) { 934 char c = *s++; 935 if (!c) { 936 if (!i) 937 break; 938 c = '/'; 939 s = array[--i]; 940 } 941 if (buf < end) 942 *buf = c; 943 } 944 rcu_read_unlock(); 945 return widen_string(buf, n, end, spec); 946 } 947 948 static noinline_for_stack 949 char *file_dentry_name(char *buf, char *end, const struct file *f, 950 struct printf_spec spec, const char *fmt) 951 { 952 if (check_pointer(&buf, end, f, spec)) 953 return buf; 954 955 return dentry_name(buf, end, f->f_path.dentry, spec, fmt); 956 } 957 #ifdef CONFIG_BLOCK 958 static noinline_for_stack 959 char *bdev_name(char *buf, char *end, struct block_device *bdev, 960 struct printf_spec spec, const char *fmt) 961 { 962 struct gendisk *hd; 963 964 if (check_pointer(&buf, end, bdev, spec)) 965 return buf; 966 967 hd = bdev->bd_disk; 968 buf = string(buf, end, hd->disk_name, spec); 969 if (bdev->bd_partno) { 970 if (isdigit(hd->disk_name[strlen(hd->disk_name)-1])) { 971 if (buf < end) 972 *buf = 'p'; 973 buf++; 974 } 975 buf = number(buf, end, bdev->bd_partno, spec); 976 } 977 return buf; 978 } 979 #endif 980 981 static noinline_for_stack 982 char *symbol_string(char *buf, char *end, void *ptr, 983 struct printf_spec spec, const char *fmt) 984 { 985 unsigned long value; 986 #ifdef CONFIG_KALLSYMS 987 char sym[KSYM_SYMBOL_LEN]; 988 #endif 989 990 if (fmt[1] == 'R') 991 ptr = __builtin_extract_return_addr(ptr); 992 value = (unsigned long)ptr; 993 994 #ifdef CONFIG_KALLSYMS 995 if (*fmt == 'B') 996 sprint_backtrace(sym, value); 997 else if (*fmt != 's') 998 sprint_symbol(sym, value); 999 else 1000 sprint_symbol_no_offset(sym, value); 1001 1002 return string_nocheck(buf, end, sym, spec); 1003 #else 1004 return special_hex_number(buf, end, value, sizeof(void *)); 1005 #endif 1006 } 1007 1008 static const struct printf_spec default_str_spec = { 1009 .field_width = -1, 1010 .precision = -1, 1011 }; 1012 1013 static const struct printf_spec default_flag_spec = { 1014 .base = 16, 1015 .precision = -1, 1016 .flags = SPECIAL | SMALL, 1017 }; 1018 1019 static const struct printf_spec default_dec_spec = { 1020 .base = 10, 1021 .precision = -1, 1022 }; 1023 1024 static const struct printf_spec default_dec02_spec = { 1025 .base = 10, 1026 .field_width = 2, 1027 .precision = -1, 1028 .flags = ZEROPAD, 1029 }; 1030 1031 static const struct printf_spec default_dec04_spec = { 1032 .base = 10, 1033 .field_width = 4, 1034 .precision = -1, 1035 .flags = ZEROPAD, 1036 }; 1037 1038 static noinline_for_stack 1039 char *resource_string(char *buf, char *end, struct resource *res, 1040 struct printf_spec spec, const char *fmt) 1041 { 1042 #ifndef IO_RSRC_PRINTK_SIZE 1043 #define IO_RSRC_PRINTK_SIZE 6 1044 #endif 1045 1046 #ifndef MEM_RSRC_PRINTK_SIZE 1047 #define MEM_RSRC_PRINTK_SIZE 10 1048 #endif 1049 static const struct printf_spec io_spec = { 1050 .base = 16, 1051 .field_width = IO_RSRC_PRINTK_SIZE, 1052 .precision = -1, 1053 .flags = SPECIAL | SMALL | ZEROPAD, 1054 }; 1055 static const struct printf_spec mem_spec = { 1056 .base = 16, 1057 .field_width = MEM_RSRC_PRINTK_SIZE, 1058 .precision = -1, 1059 .flags = SPECIAL | SMALL | ZEROPAD, 1060 }; 1061 static const struct printf_spec bus_spec = { 1062 .base = 16, 1063 .field_width = 2, 1064 .precision = -1, 1065 .flags = SMALL | ZEROPAD, 1066 }; 1067 static const struct printf_spec str_spec = { 1068 .field_width = -1, 1069 .precision = 10, 1070 .flags = LEFT, 1071 }; 1072 1073 /* 32-bit res (sizeof==4): 10 chars in dec, 10 in hex ("0x" + 8) 1074 * 64-bit res (sizeof==8): 20 chars in dec, 18 in hex ("0x" + 16) */ 1075 #define RSRC_BUF_SIZE ((2 * sizeof(resource_size_t)) + 4) 1076 #define FLAG_BUF_SIZE (2 * sizeof(res->flags)) 1077 #define DECODED_BUF_SIZE sizeof("[mem - 64bit pref window disabled]") 1078 #define RAW_BUF_SIZE sizeof("[mem - flags 0x]") 1079 char sym[max(2*RSRC_BUF_SIZE + DECODED_BUF_SIZE, 1080 2*RSRC_BUF_SIZE + FLAG_BUF_SIZE + RAW_BUF_SIZE)]; 1081 1082 char *p = sym, *pend = sym + sizeof(sym); 1083 int decode = (fmt[0] == 'R') ? 1 : 0; 1084 const struct printf_spec *specp; 1085 1086 if (check_pointer(&buf, end, res, spec)) 1087 return buf; 1088 1089 *p++ = '['; 1090 if (res->flags & IORESOURCE_IO) { 1091 p = string_nocheck(p, pend, "io ", str_spec); 1092 specp = &io_spec; 1093 } else if (res->flags & IORESOURCE_MEM) { 1094 p = string_nocheck(p, pend, "mem ", str_spec); 1095 specp = &mem_spec; 1096 } else if (res->flags & IORESOURCE_IRQ) { 1097 p = string_nocheck(p, pend, "irq ", str_spec); 1098 specp = &default_dec_spec; 1099 } else if (res->flags & IORESOURCE_DMA) { 1100 p = string_nocheck(p, pend, "dma ", str_spec); 1101 specp = &default_dec_spec; 1102 } else if (res->flags & IORESOURCE_BUS) { 1103 p = string_nocheck(p, pend, "bus ", str_spec); 1104 specp = &bus_spec; 1105 } else { 1106 p = string_nocheck(p, pend, "??? ", str_spec); 1107 specp = &mem_spec; 1108 decode = 0; 1109 } 1110 if (decode && res->flags & IORESOURCE_UNSET) { 1111 p = string_nocheck(p, pend, "size ", str_spec); 1112 p = number(p, pend, resource_size(res), *specp); 1113 } else { 1114 p = number(p, pend, res->start, *specp); 1115 if (res->start != res->end) { 1116 *p++ = '-'; 1117 p = number(p, pend, res->end, *specp); 1118 } 1119 } 1120 if (decode) { 1121 if (res->flags & IORESOURCE_MEM_64) 1122 p = string_nocheck(p, pend, " 64bit", str_spec); 1123 if (res->flags & IORESOURCE_PREFETCH) 1124 p = string_nocheck(p, pend, " pref", str_spec); 1125 if (res->flags & IORESOURCE_WINDOW) 1126 p = string_nocheck(p, pend, " window", str_spec); 1127 if (res->flags & IORESOURCE_DISABLED) 1128 p = string_nocheck(p, pend, " disabled", str_spec); 1129 } else { 1130 p = string_nocheck(p, pend, " flags ", str_spec); 1131 p = number(p, pend, res->flags, default_flag_spec); 1132 } 1133 *p++ = ']'; 1134 *p = '\0'; 1135 1136 return string_nocheck(buf, end, sym, spec); 1137 } 1138 1139 static noinline_for_stack 1140 char *hex_string(char *buf, char *end, u8 *addr, struct printf_spec spec, 1141 const char *fmt) 1142 { 1143 int i, len = 1; /* if we pass '%ph[CDN]', field width remains 1144 negative value, fallback to the default */ 1145 char separator; 1146 1147 if (spec.field_width == 0) 1148 /* nothing to print */ 1149 return buf; 1150 1151 if (check_pointer(&buf, end, addr, spec)) 1152 return buf; 1153 1154 switch (fmt[1]) { 1155 case 'C': 1156 separator = ':'; 1157 break; 1158 case 'D': 1159 separator = '-'; 1160 break; 1161 case 'N': 1162 separator = 0; 1163 break; 1164 default: 1165 separator = ' '; 1166 break; 1167 } 1168 1169 if (spec.field_width > 0) 1170 len = min_t(int, spec.field_width, 64); 1171 1172 for (i = 0; i < len; ++i) { 1173 if (buf < end) 1174 *buf = hex_asc_hi(addr[i]); 1175 ++buf; 1176 if (buf < end) 1177 *buf = hex_asc_lo(addr[i]); 1178 ++buf; 1179 1180 if (separator && i != len - 1) { 1181 if (buf < end) 1182 *buf = separator; 1183 ++buf; 1184 } 1185 } 1186 1187 return buf; 1188 } 1189 1190 static noinline_for_stack 1191 char *bitmap_string(char *buf, char *end, unsigned long *bitmap, 1192 struct printf_spec spec, const char *fmt) 1193 { 1194 const int CHUNKSZ = 32; 1195 int nr_bits = max_t(int, spec.field_width, 0); 1196 int i, chunksz; 1197 bool first = true; 1198 1199 if (check_pointer(&buf, end, bitmap, spec)) 1200 return buf; 1201 1202 /* reused to print numbers */ 1203 spec = (struct printf_spec){ .flags = SMALL | ZEROPAD, .base = 16 }; 1204 1205 chunksz = nr_bits & (CHUNKSZ - 1); 1206 if (chunksz == 0) 1207 chunksz = CHUNKSZ; 1208 1209 i = ALIGN(nr_bits, CHUNKSZ) - CHUNKSZ; 1210 for (; i >= 0; i -= CHUNKSZ) { 1211 u32 chunkmask, val; 1212 int word, bit; 1213 1214 chunkmask = ((1ULL << chunksz) - 1); 1215 word = i / BITS_PER_LONG; 1216 bit = i % BITS_PER_LONG; 1217 val = (bitmap[word] >> bit) & chunkmask; 1218 1219 if (!first) { 1220 if (buf < end) 1221 *buf = ','; 1222 buf++; 1223 } 1224 first = false; 1225 1226 spec.field_width = DIV_ROUND_UP(chunksz, 4); 1227 buf = number(buf, end, val, spec); 1228 1229 chunksz = CHUNKSZ; 1230 } 1231 return buf; 1232 } 1233 1234 static noinline_for_stack 1235 char *bitmap_list_string(char *buf, char *end, unsigned long *bitmap, 1236 struct printf_spec spec, const char *fmt) 1237 { 1238 int nr_bits = max_t(int, spec.field_width, 0); 1239 /* current bit is 'cur', most recently seen range is [rbot, rtop] */ 1240 int cur, rbot, rtop; 1241 bool first = true; 1242 1243 if (check_pointer(&buf, end, bitmap, spec)) 1244 return buf; 1245 1246 rbot = cur = find_first_bit(bitmap, nr_bits); 1247 while (cur < nr_bits) { 1248 rtop = cur; 1249 cur = find_next_bit(bitmap, nr_bits, cur + 1); 1250 if (cur < nr_bits && cur <= rtop + 1) 1251 continue; 1252 1253 if (!first) { 1254 if (buf < end) 1255 *buf = ','; 1256 buf++; 1257 } 1258 first = false; 1259 1260 buf = number(buf, end, rbot, default_dec_spec); 1261 if (rbot < rtop) { 1262 if (buf < end) 1263 *buf = '-'; 1264 buf++; 1265 1266 buf = number(buf, end, rtop, default_dec_spec); 1267 } 1268 1269 rbot = cur; 1270 } 1271 return buf; 1272 } 1273 1274 static noinline_for_stack 1275 char *mac_address_string(char *buf, char *end, u8 *addr, 1276 struct printf_spec spec, const char *fmt) 1277 { 1278 char mac_addr[sizeof("xx:xx:xx:xx:xx:xx")]; 1279 char *p = mac_addr; 1280 int i; 1281 char separator; 1282 bool reversed = false; 1283 1284 if (check_pointer(&buf, end, addr, spec)) 1285 return buf; 1286 1287 switch (fmt[1]) { 1288 case 'F': 1289 separator = '-'; 1290 break; 1291 1292 case 'R': 1293 reversed = true; 1294 fallthrough; 1295 1296 default: 1297 separator = ':'; 1298 break; 1299 } 1300 1301 for (i = 0; i < 6; i++) { 1302 if (reversed) 1303 p = hex_byte_pack(p, addr[5 - i]); 1304 else 1305 p = hex_byte_pack(p, addr[i]); 1306 1307 if (fmt[0] == 'M' && i != 5) 1308 *p++ = separator; 1309 } 1310 *p = '\0'; 1311 1312 return string_nocheck(buf, end, mac_addr, spec); 1313 } 1314 1315 static noinline_for_stack 1316 char *ip4_string(char *p, const u8 *addr, const char *fmt) 1317 { 1318 int i; 1319 bool leading_zeros = (fmt[0] == 'i'); 1320 int index; 1321 int step; 1322 1323 switch (fmt[2]) { 1324 case 'h': 1325 #ifdef __BIG_ENDIAN 1326 index = 0; 1327 step = 1; 1328 #else 1329 index = 3; 1330 step = -1; 1331 #endif 1332 break; 1333 case 'l': 1334 index = 3; 1335 step = -1; 1336 break; 1337 case 'n': 1338 case 'b': 1339 default: 1340 index = 0; 1341 step = 1; 1342 break; 1343 } 1344 for (i = 0; i < 4; i++) { 1345 char temp[4] __aligned(2); /* hold each IP quad in reverse order */ 1346 int digits = put_dec_trunc8(temp, addr[index]) - temp; 1347 if (leading_zeros) { 1348 if (digits < 3) 1349 *p++ = '0'; 1350 if (digits < 2) 1351 *p++ = '0'; 1352 } 1353 /* reverse the digits in the quad */ 1354 while (digits--) 1355 *p++ = temp[digits]; 1356 if (i < 3) 1357 *p++ = '.'; 1358 index += step; 1359 } 1360 *p = '\0'; 1361 1362 return p; 1363 } 1364 1365 static noinline_for_stack 1366 char *ip6_compressed_string(char *p, const char *addr) 1367 { 1368 int i, j, range; 1369 unsigned char zerolength[8]; 1370 int longest = 1; 1371 int colonpos = -1; 1372 u16 word; 1373 u8 hi, lo; 1374 bool needcolon = false; 1375 bool useIPv4; 1376 struct in6_addr in6; 1377 1378 memcpy(&in6, addr, sizeof(struct in6_addr)); 1379 1380 useIPv4 = ipv6_addr_v4mapped(&in6) || ipv6_addr_is_isatap(&in6); 1381 1382 memset(zerolength, 0, sizeof(zerolength)); 1383 1384 if (useIPv4) 1385 range = 6; 1386 else 1387 range = 8; 1388 1389 /* find position of longest 0 run */ 1390 for (i = 0; i < range; i++) { 1391 for (j = i; j < range; j++) { 1392 if (in6.s6_addr16[j] != 0) 1393 break; 1394 zerolength[i]++; 1395 } 1396 } 1397 for (i = 0; i < range; i++) { 1398 if (zerolength[i] > longest) { 1399 longest = zerolength[i]; 1400 colonpos = i; 1401 } 1402 } 1403 if (longest == 1) /* don't compress a single 0 */ 1404 colonpos = -1; 1405 1406 /* emit address */ 1407 for (i = 0; i < range; i++) { 1408 if (i == colonpos) { 1409 if (needcolon || i == 0) 1410 *p++ = ':'; 1411 *p++ = ':'; 1412 needcolon = false; 1413 i += longest - 1; 1414 continue; 1415 } 1416 if (needcolon) { 1417 *p++ = ':'; 1418 needcolon = false; 1419 } 1420 /* hex u16 without leading 0s */ 1421 word = ntohs(in6.s6_addr16[i]); 1422 hi = word >> 8; 1423 lo = word & 0xff; 1424 if (hi) { 1425 if (hi > 0x0f) 1426 p = hex_byte_pack(p, hi); 1427 else 1428 *p++ = hex_asc_lo(hi); 1429 p = hex_byte_pack(p, lo); 1430 } 1431 else if (lo > 0x0f) 1432 p = hex_byte_pack(p, lo); 1433 else 1434 *p++ = hex_asc_lo(lo); 1435 needcolon = true; 1436 } 1437 1438 if (useIPv4) { 1439 if (needcolon) 1440 *p++ = ':'; 1441 p = ip4_string(p, &in6.s6_addr[12], "I4"); 1442 } 1443 *p = '\0'; 1444 1445 return p; 1446 } 1447 1448 static noinline_for_stack 1449 char *ip6_string(char *p, const char *addr, const char *fmt) 1450 { 1451 int i; 1452 1453 for (i = 0; i < 8; i++) { 1454 p = hex_byte_pack(p, *addr++); 1455 p = hex_byte_pack(p, *addr++); 1456 if (fmt[0] == 'I' && i != 7) 1457 *p++ = ':'; 1458 } 1459 *p = '\0'; 1460 1461 return p; 1462 } 1463 1464 static noinline_for_stack 1465 char *ip6_addr_string(char *buf, char *end, const u8 *addr, 1466 struct printf_spec spec, const char *fmt) 1467 { 1468 char ip6_addr[sizeof("xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255")]; 1469 1470 if (fmt[0] == 'I' && fmt[2] == 'c') 1471 ip6_compressed_string(ip6_addr, addr); 1472 else 1473 ip6_string(ip6_addr, addr, fmt); 1474 1475 return string_nocheck(buf, end, ip6_addr, spec); 1476 } 1477 1478 static noinline_for_stack 1479 char *ip4_addr_string(char *buf, char *end, const u8 *addr, 1480 struct printf_spec spec, const char *fmt) 1481 { 1482 char ip4_addr[sizeof("255.255.255.255")]; 1483 1484 ip4_string(ip4_addr, addr, fmt); 1485 1486 return string_nocheck(buf, end, ip4_addr, spec); 1487 } 1488 1489 static noinline_for_stack 1490 char *ip6_addr_string_sa(char *buf, char *end, const struct sockaddr_in6 *sa, 1491 struct printf_spec spec, const char *fmt) 1492 { 1493 bool have_p = false, have_s = false, have_f = false, have_c = false; 1494 char ip6_addr[sizeof("[xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255]") + 1495 sizeof(":12345") + sizeof("/123456789") + 1496 sizeof("%1234567890")]; 1497 char *p = ip6_addr, *pend = ip6_addr + sizeof(ip6_addr); 1498 const u8 *addr = (const u8 *) &sa->sin6_addr; 1499 char fmt6[2] = { fmt[0], '6' }; 1500 u8 off = 0; 1501 1502 fmt++; 1503 while (isalpha(*++fmt)) { 1504 switch (*fmt) { 1505 case 'p': 1506 have_p = true; 1507 break; 1508 case 'f': 1509 have_f = true; 1510 break; 1511 case 's': 1512 have_s = true; 1513 break; 1514 case 'c': 1515 have_c = true; 1516 break; 1517 } 1518 } 1519 1520 if (have_p || have_s || have_f) { 1521 *p = '['; 1522 off = 1; 1523 } 1524 1525 if (fmt6[0] == 'I' && have_c) 1526 p = ip6_compressed_string(ip6_addr + off, addr); 1527 else 1528 p = ip6_string(ip6_addr + off, addr, fmt6); 1529 1530 if (have_p || have_s || have_f) 1531 *p++ = ']'; 1532 1533 if (have_p) { 1534 *p++ = ':'; 1535 p = number(p, pend, ntohs(sa->sin6_port), spec); 1536 } 1537 if (have_f) { 1538 *p++ = '/'; 1539 p = number(p, pend, ntohl(sa->sin6_flowinfo & 1540 IPV6_FLOWINFO_MASK), spec); 1541 } 1542 if (have_s) { 1543 *p++ = '%'; 1544 p = number(p, pend, sa->sin6_scope_id, spec); 1545 } 1546 *p = '\0'; 1547 1548 return string_nocheck(buf, end, ip6_addr, spec); 1549 } 1550 1551 static noinline_for_stack 1552 char *ip4_addr_string_sa(char *buf, char *end, const struct sockaddr_in *sa, 1553 struct printf_spec spec, const char *fmt) 1554 { 1555 bool have_p = false; 1556 char *p, ip4_addr[sizeof("255.255.255.255") + sizeof(":12345")]; 1557 char *pend = ip4_addr + sizeof(ip4_addr); 1558 const u8 *addr = (const u8 *) &sa->sin_addr.s_addr; 1559 char fmt4[3] = { fmt[0], '4', 0 }; 1560 1561 fmt++; 1562 while (isalpha(*++fmt)) { 1563 switch (*fmt) { 1564 case 'p': 1565 have_p = true; 1566 break; 1567 case 'h': 1568 case 'l': 1569 case 'n': 1570 case 'b': 1571 fmt4[2] = *fmt; 1572 break; 1573 } 1574 } 1575 1576 p = ip4_string(ip4_addr, addr, fmt4); 1577 if (have_p) { 1578 *p++ = ':'; 1579 p = number(p, pend, ntohs(sa->sin_port), spec); 1580 } 1581 *p = '\0'; 1582 1583 return string_nocheck(buf, end, ip4_addr, spec); 1584 } 1585 1586 static noinline_for_stack 1587 char *ip_addr_string(char *buf, char *end, const void *ptr, 1588 struct printf_spec spec, const char *fmt) 1589 { 1590 char *err_fmt_msg; 1591 1592 if (check_pointer(&buf, end, ptr, spec)) 1593 return buf; 1594 1595 switch (fmt[1]) { 1596 case '6': 1597 return ip6_addr_string(buf, end, ptr, spec, fmt); 1598 case '4': 1599 return ip4_addr_string(buf, end, ptr, spec, fmt); 1600 case 'S': { 1601 const union { 1602 struct sockaddr raw; 1603 struct sockaddr_in v4; 1604 struct sockaddr_in6 v6; 1605 } *sa = ptr; 1606 1607 switch (sa->raw.sa_family) { 1608 case AF_INET: 1609 return ip4_addr_string_sa(buf, end, &sa->v4, spec, fmt); 1610 case AF_INET6: 1611 return ip6_addr_string_sa(buf, end, &sa->v6, spec, fmt); 1612 default: 1613 return error_string(buf, end, "(einval)", spec); 1614 }} 1615 } 1616 1617 err_fmt_msg = fmt[0] == 'i' ? "(%pi?)" : "(%pI?)"; 1618 return error_string(buf, end, err_fmt_msg, spec); 1619 } 1620 1621 static noinline_for_stack 1622 char *escaped_string(char *buf, char *end, u8 *addr, struct printf_spec spec, 1623 const char *fmt) 1624 { 1625 bool found = true; 1626 int count = 1; 1627 unsigned int flags = 0; 1628 int len; 1629 1630 if (spec.field_width == 0) 1631 return buf; /* nothing to print */ 1632 1633 if (check_pointer(&buf, end, addr, spec)) 1634 return buf; 1635 1636 do { 1637 switch (fmt[count++]) { 1638 case 'a': 1639 flags |= ESCAPE_ANY; 1640 break; 1641 case 'c': 1642 flags |= ESCAPE_SPECIAL; 1643 break; 1644 case 'h': 1645 flags |= ESCAPE_HEX; 1646 break; 1647 case 'n': 1648 flags |= ESCAPE_NULL; 1649 break; 1650 case 'o': 1651 flags |= ESCAPE_OCTAL; 1652 break; 1653 case 'p': 1654 flags |= ESCAPE_NP; 1655 break; 1656 case 's': 1657 flags |= ESCAPE_SPACE; 1658 break; 1659 default: 1660 found = false; 1661 break; 1662 } 1663 } while (found); 1664 1665 if (!flags) 1666 flags = ESCAPE_ANY_NP; 1667 1668 len = spec.field_width < 0 ? 1 : spec.field_width; 1669 1670 /* 1671 * string_escape_mem() writes as many characters as it can to 1672 * the given buffer, and returns the total size of the output 1673 * had the buffer been big enough. 1674 */ 1675 buf += string_escape_mem(addr, len, buf, buf < end ? end - buf : 0, flags, NULL); 1676 1677 return buf; 1678 } 1679 1680 static char *va_format(char *buf, char *end, struct va_format *va_fmt, 1681 struct printf_spec spec, const char *fmt) 1682 { 1683 va_list va; 1684 1685 if (check_pointer(&buf, end, va_fmt, spec)) 1686 return buf; 1687 1688 va_copy(va, *va_fmt->va); 1689 buf += vsnprintf(buf, end > buf ? end - buf : 0, va_fmt->fmt, va); 1690 va_end(va); 1691 1692 return buf; 1693 } 1694 1695 static noinline_for_stack 1696 char *uuid_string(char *buf, char *end, const u8 *addr, 1697 struct printf_spec spec, const char *fmt) 1698 { 1699 char uuid[UUID_STRING_LEN + 1]; 1700 char *p = uuid; 1701 int i; 1702 const u8 *index = uuid_index; 1703 bool uc = false; 1704 1705 if (check_pointer(&buf, end, addr, spec)) 1706 return buf; 1707 1708 switch (*(++fmt)) { 1709 case 'L': 1710 uc = true; 1711 fallthrough; 1712 case 'l': 1713 index = guid_index; 1714 break; 1715 case 'B': 1716 uc = true; 1717 break; 1718 } 1719 1720 for (i = 0; i < 16; i++) { 1721 if (uc) 1722 p = hex_byte_pack_upper(p, addr[index[i]]); 1723 else 1724 p = hex_byte_pack(p, addr[index[i]]); 1725 switch (i) { 1726 case 3: 1727 case 5: 1728 case 7: 1729 case 9: 1730 *p++ = '-'; 1731 break; 1732 } 1733 } 1734 1735 *p = 0; 1736 1737 return string_nocheck(buf, end, uuid, spec); 1738 } 1739 1740 static noinline_for_stack 1741 char *netdev_bits(char *buf, char *end, const void *addr, 1742 struct printf_spec spec, const char *fmt) 1743 { 1744 unsigned long long num; 1745 int size; 1746 1747 if (check_pointer(&buf, end, addr, spec)) 1748 return buf; 1749 1750 switch (fmt[1]) { 1751 case 'F': 1752 num = *(const netdev_features_t *)addr; 1753 size = sizeof(netdev_features_t); 1754 break; 1755 default: 1756 return error_string(buf, end, "(%pN?)", spec); 1757 } 1758 1759 return special_hex_number(buf, end, num, size); 1760 } 1761 1762 static noinline_for_stack 1763 char *fourcc_string(char *buf, char *end, const u32 *fourcc, 1764 struct printf_spec spec, const char *fmt) 1765 { 1766 char output[sizeof("0123 little-endian (0x01234567)")]; 1767 char *p = output; 1768 unsigned int i; 1769 u32 val; 1770 1771 if (fmt[1] != 'c' || fmt[2] != 'c') 1772 return error_string(buf, end, "(%p4?)", spec); 1773 1774 if (check_pointer(&buf, end, fourcc, spec)) 1775 return buf; 1776 1777 val = *fourcc & ~BIT(31); 1778 1779 for (i = 0; i < sizeof(*fourcc); i++) { 1780 unsigned char c = val >> (i * 8); 1781 1782 /* Print non-control ASCII characters as-is, dot otherwise */ 1783 *p++ = isascii(c) && isprint(c) ? c : '.'; 1784 } 1785 1786 strcpy(p, *fourcc & BIT(31) ? " big-endian" : " little-endian"); 1787 p += strlen(p); 1788 1789 *p++ = ' '; 1790 *p++ = '('; 1791 p = special_hex_number(p, output + sizeof(output) - 2, *fourcc, sizeof(u32)); 1792 *p++ = ')'; 1793 *p = '\0'; 1794 1795 return string(buf, end, output, spec); 1796 } 1797 1798 static noinline_for_stack 1799 char *address_val(char *buf, char *end, const void *addr, 1800 struct printf_spec spec, const char *fmt) 1801 { 1802 unsigned long long num; 1803 int size; 1804 1805 if (check_pointer(&buf, end, addr, spec)) 1806 return buf; 1807 1808 switch (fmt[1]) { 1809 case 'd': 1810 num = *(const dma_addr_t *)addr; 1811 size = sizeof(dma_addr_t); 1812 break; 1813 case 'p': 1814 default: 1815 num = *(const phys_addr_t *)addr; 1816 size = sizeof(phys_addr_t); 1817 break; 1818 } 1819 1820 return special_hex_number(buf, end, num, size); 1821 } 1822 1823 static noinline_for_stack 1824 char *date_str(char *buf, char *end, const struct rtc_time *tm, bool r) 1825 { 1826 int year = tm->tm_year + (r ? 0 : 1900); 1827 int mon = tm->tm_mon + (r ? 0 : 1); 1828 1829 buf = number(buf, end, year, default_dec04_spec); 1830 if (buf < end) 1831 *buf = '-'; 1832 buf++; 1833 1834 buf = number(buf, end, mon, default_dec02_spec); 1835 if (buf < end) 1836 *buf = '-'; 1837 buf++; 1838 1839 return number(buf, end, tm->tm_mday, default_dec02_spec); 1840 } 1841 1842 static noinline_for_stack 1843 char *time_str(char *buf, char *end, const struct rtc_time *tm, bool r) 1844 { 1845 buf = number(buf, end, tm->tm_hour, default_dec02_spec); 1846 if (buf < end) 1847 *buf = ':'; 1848 buf++; 1849 1850 buf = number(buf, end, tm->tm_min, default_dec02_spec); 1851 if (buf < end) 1852 *buf = ':'; 1853 buf++; 1854 1855 return number(buf, end, tm->tm_sec, default_dec02_spec); 1856 } 1857 1858 static noinline_for_stack 1859 char *rtc_str(char *buf, char *end, const struct rtc_time *tm, 1860 struct printf_spec spec, const char *fmt) 1861 { 1862 bool have_t = true, have_d = true; 1863 bool raw = false, iso8601_separator = true; 1864 bool found = true; 1865 int count = 2; 1866 1867 if (check_pointer(&buf, end, tm, spec)) 1868 return buf; 1869 1870 switch (fmt[count]) { 1871 case 'd': 1872 have_t = false; 1873 count++; 1874 break; 1875 case 't': 1876 have_d = false; 1877 count++; 1878 break; 1879 } 1880 1881 do { 1882 switch (fmt[count++]) { 1883 case 'r': 1884 raw = true; 1885 break; 1886 case 's': 1887 iso8601_separator = false; 1888 break; 1889 default: 1890 found = false; 1891 break; 1892 } 1893 } while (found); 1894 1895 if (have_d) 1896 buf = date_str(buf, end, tm, raw); 1897 if (have_d && have_t) { 1898 if (buf < end) 1899 *buf = iso8601_separator ? 'T' : ' '; 1900 buf++; 1901 } 1902 if (have_t) 1903 buf = time_str(buf, end, tm, raw); 1904 1905 return buf; 1906 } 1907 1908 static noinline_for_stack 1909 char *time64_str(char *buf, char *end, const time64_t time, 1910 struct printf_spec spec, const char *fmt) 1911 { 1912 struct rtc_time rtc_time; 1913 struct tm tm; 1914 1915 time64_to_tm(time, 0, &tm); 1916 1917 rtc_time.tm_sec = tm.tm_sec; 1918 rtc_time.tm_min = tm.tm_min; 1919 rtc_time.tm_hour = tm.tm_hour; 1920 rtc_time.tm_mday = tm.tm_mday; 1921 rtc_time.tm_mon = tm.tm_mon; 1922 rtc_time.tm_year = tm.tm_year; 1923 rtc_time.tm_wday = tm.tm_wday; 1924 rtc_time.tm_yday = tm.tm_yday; 1925 1926 rtc_time.tm_isdst = 0; 1927 1928 return rtc_str(buf, end, &rtc_time, spec, fmt); 1929 } 1930 1931 static noinline_for_stack 1932 char *time_and_date(char *buf, char *end, void *ptr, struct printf_spec spec, 1933 const char *fmt) 1934 { 1935 switch (fmt[1]) { 1936 case 'R': 1937 return rtc_str(buf, end, (const struct rtc_time *)ptr, spec, fmt); 1938 case 'T': 1939 return time64_str(buf, end, *(const time64_t *)ptr, spec, fmt); 1940 default: 1941 return error_string(buf, end, "(%pt?)", spec); 1942 } 1943 } 1944 1945 static noinline_for_stack 1946 char *clock(char *buf, char *end, struct clk *clk, struct printf_spec spec, 1947 const char *fmt) 1948 { 1949 if (!IS_ENABLED(CONFIG_HAVE_CLK)) 1950 return error_string(buf, end, "(%pC?)", spec); 1951 1952 if (check_pointer(&buf, end, clk, spec)) 1953 return buf; 1954 1955 switch (fmt[1]) { 1956 case 'n': 1957 default: 1958 #ifdef CONFIG_COMMON_CLK 1959 return string(buf, end, __clk_get_name(clk), spec); 1960 #else 1961 return ptr_to_id(buf, end, clk, spec); 1962 #endif 1963 } 1964 } 1965 1966 static 1967 char *format_flags(char *buf, char *end, unsigned long flags, 1968 const struct trace_print_flags *names) 1969 { 1970 unsigned long mask; 1971 1972 for ( ; flags && names->name; names++) { 1973 mask = names->mask; 1974 if ((flags & mask) != mask) 1975 continue; 1976 1977 buf = string(buf, end, names->name, default_str_spec); 1978 1979 flags &= ~mask; 1980 if (flags) { 1981 if (buf < end) 1982 *buf = '|'; 1983 buf++; 1984 } 1985 } 1986 1987 if (flags) 1988 buf = number(buf, end, flags, default_flag_spec); 1989 1990 return buf; 1991 } 1992 1993 struct page_flags_fields { 1994 int width; 1995 int shift; 1996 int mask; 1997 const struct printf_spec *spec; 1998 const char *name; 1999 }; 2000 2001 static const struct page_flags_fields pff[] = { 2002 {SECTIONS_WIDTH, SECTIONS_PGSHIFT, SECTIONS_MASK, 2003 &default_dec_spec, "section"}, 2004 {NODES_WIDTH, NODES_PGSHIFT, NODES_MASK, 2005 &default_dec_spec, "node"}, 2006 {ZONES_WIDTH, ZONES_PGSHIFT, ZONES_MASK, 2007 &default_dec_spec, "zone"}, 2008 {LAST_CPUPID_WIDTH, LAST_CPUPID_PGSHIFT, LAST_CPUPID_MASK, 2009 &default_flag_spec, "lastcpupid"}, 2010 {KASAN_TAG_WIDTH, KASAN_TAG_PGSHIFT, KASAN_TAG_MASK, 2011 &default_flag_spec, "kasantag"}, 2012 }; 2013 2014 static 2015 char *format_page_flags(char *buf, char *end, unsigned long flags) 2016 { 2017 unsigned long main_flags = flags & (BIT(NR_PAGEFLAGS) - 1); 2018 bool append = false; 2019 int i; 2020 2021 /* Page flags from the main area. */ 2022 if (main_flags) { 2023 buf = format_flags(buf, end, main_flags, pageflag_names); 2024 append = true; 2025 } 2026 2027 /* Page flags from the fields area */ 2028 for (i = 0; i < ARRAY_SIZE(pff); i++) { 2029 /* Skip undefined fields. */ 2030 if (!pff[i].width) 2031 continue; 2032 2033 /* Format: Flag Name + '=' (equals sign) + Number + '|' (separator) */ 2034 if (append) { 2035 if (buf < end) 2036 *buf = '|'; 2037 buf++; 2038 } 2039 2040 buf = string(buf, end, pff[i].name, default_str_spec); 2041 if (buf < end) 2042 *buf = '='; 2043 buf++; 2044 buf = number(buf, end, (flags >> pff[i].shift) & pff[i].mask, 2045 *pff[i].spec); 2046 2047 append = true; 2048 } 2049 2050 return buf; 2051 } 2052 2053 static noinline_for_stack 2054 char *flags_string(char *buf, char *end, void *flags_ptr, 2055 struct printf_spec spec, const char *fmt) 2056 { 2057 unsigned long flags; 2058 const struct trace_print_flags *names; 2059 2060 if (check_pointer(&buf, end, flags_ptr, spec)) 2061 return buf; 2062 2063 switch (fmt[1]) { 2064 case 'p': 2065 return format_page_flags(buf, end, *(unsigned long *)flags_ptr); 2066 case 'v': 2067 flags = *(unsigned long *)flags_ptr; 2068 names = vmaflag_names; 2069 break; 2070 case 'g': 2071 flags = (__force unsigned long)(*(gfp_t *)flags_ptr); 2072 names = gfpflag_names; 2073 break; 2074 default: 2075 return error_string(buf, end, "(%pG?)", spec); 2076 } 2077 2078 return format_flags(buf, end, flags, names); 2079 } 2080 2081 static noinline_for_stack 2082 char *fwnode_full_name_string(struct fwnode_handle *fwnode, char *buf, 2083 char *end) 2084 { 2085 int depth; 2086 2087 /* Loop starting from the root node to the current node. */ 2088 for (depth = fwnode_count_parents(fwnode); depth >= 0; depth--) { 2089 struct fwnode_handle *__fwnode = 2090 fwnode_get_nth_parent(fwnode, depth); 2091 2092 buf = string(buf, end, fwnode_get_name_prefix(__fwnode), 2093 default_str_spec); 2094 buf = string(buf, end, fwnode_get_name(__fwnode), 2095 default_str_spec); 2096 2097 fwnode_handle_put(__fwnode); 2098 } 2099 2100 return buf; 2101 } 2102 2103 static noinline_for_stack 2104 char *device_node_string(char *buf, char *end, struct device_node *dn, 2105 struct printf_spec spec, const char *fmt) 2106 { 2107 char tbuf[sizeof("xxxx") + 1]; 2108 const char *p; 2109 int ret; 2110 char *buf_start = buf; 2111 struct property *prop; 2112 bool has_mult, pass; 2113 2114 struct printf_spec str_spec = spec; 2115 str_spec.field_width = -1; 2116 2117 if (fmt[0] != 'F') 2118 return error_string(buf, end, "(%pO?)", spec); 2119 2120 if (!IS_ENABLED(CONFIG_OF)) 2121 return error_string(buf, end, "(%pOF?)", spec); 2122 2123 if (check_pointer(&buf, end, dn, spec)) 2124 return buf; 2125 2126 /* simple case without anything any more format specifiers */ 2127 fmt++; 2128 if (fmt[0] == '\0' || strcspn(fmt,"fnpPFcC") > 0) 2129 fmt = "f"; 2130 2131 for (pass = false; strspn(fmt,"fnpPFcC"); fmt++, pass = true) { 2132 int precision; 2133 if (pass) { 2134 if (buf < end) 2135 *buf = ':'; 2136 buf++; 2137 } 2138 2139 switch (*fmt) { 2140 case 'f': /* full_name */ 2141 buf = fwnode_full_name_string(of_fwnode_handle(dn), buf, 2142 end); 2143 break; 2144 case 'n': /* name */ 2145 p = fwnode_get_name(of_fwnode_handle(dn)); 2146 precision = str_spec.precision; 2147 str_spec.precision = strchrnul(p, '@') - p; 2148 buf = string(buf, end, p, str_spec); 2149 str_spec.precision = precision; 2150 break; 2151 case 'p': /* phandle */ 2152 buf = number(buf, end, (unsigned int)dn->phandle, default_dec_spec); 2153 break; 2154 case 'P': /* path-spec */ 2155 p = fwnode_get_name(of_fwnode_handle(dn)); 2156 if (!p[1]) 2157 p = "/"; 2158 buf = string(buf, end, p, str_spec); 2159 break; 2160 case 'F': /* flags */ 2161 tbuf[0] = of_node_check_flag(dn, OF_DYNAMIC) ? 'D' : '-'; 2162 tbuf[1] = of_node_check_flag(dn, OF_DETACHED) ? 'd' : '-'; 2163 tbuf[2] = of_node_check_flag(dn, OF_POPULATED) ? 'P' : '-'; 2164 tbuf[3] = of_node_check_flag(dn, OF_POPULATED_BUS) ? 'B' : '-'; 2165 tbuf[4] = 0; 2166 buf = string_nocheck(buf, end, tbuf, str_spec); 2167 break; 2168 case 'c': /* major compatible string */ 2169 ret = of_property_read_string(dn, "compatible", &p); 2170 if (!ret) 2171 buf = string(buf, end, p, str_spec); 2172 break; 2173 case 'C': /* full compatible string */ 2174 has_mult = false; 2175 of_property_for_each_string(dn, "compatible", prop, p) { 2176 if (has_mult) 2177 buf = string_nocheck(buf, end, ",", str_spec); 2178 buf = string_nocheck(buf, end, "\"", str_spec); 2179 buf = string(buf, end, p, str_spec); 2180 buf = string_nocheck(buf, end, "\"", str_spec); 2181 2182 has_mult = true; 2183 } 2184 break; 2185 default: 2186 break; 2187 } 2188 } 2189 2190 return widen_string(buf, buf - buf_start, end, spec); 2191 } 2192 2193 static noinline_for_stack 2194 char *fwnode_string(char *buf, char *end, struct fwnode_handle *fwnode, 2195 struct printf_spec spec, const char *fmt) 2196 { 2197 struct printf_spec str_spec = spec; 2198 char *buf_start = buf; 2199 2200 str_spec.field_width = -1; 2201 2202 if (*fmt != 'w') 2203 return error_string(buf, end, "(%pf?)", spec); 2204 2205 if (check_pointer(&buf, end, fwnode, spec)) 2206 return buf; 2207 2208 fmt++; 2209 2210 switch (*fmt) { 2211 case 'P': /* name */ 2212 buf = string(buf, end, fwnode_get_name(fwnode), str_spec); 2213 break; 2214 case 'f': /* full_name */ 2215 default: 2216 buf = fwnode_full_name_string(fwnode, buf, end); 2217 break; 2218 } 2219 2220 return widen_string(buf, buf - buf_start, end, spec); 2221 } 2222 2223 /* Disable pointer hashing if requested */ 2224 bool no_hash_pointers __ro_after_init; 2225 EXPORT_SYMBOL_GPL(no_hash_pointers); 2226 2227 int __init no_hash_pointers_enable(char *str) 2228 { 2229 if (no_hash_pointers) 2230 return 0; 2231 2232 no_hash_pointers = true; 2233 2234 pr_warn("**********************************************************\n"); 2235 pr_warn("** NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE **\n"); 2236 pr_warn("** **\n"); 2237 pr_warn("** This system shows unhashed kernel memory addresses **\n"); 2238 pr_warn("** via the console, logs, and other interfaces. This **\n"); 2239 pr_warn("** might reduce the security of your system. **\n"); 2240 pr_warn("** **\n"); 2241 pr_warn("** If you see this message and you are not debugging **\n"); 2242 pr_warn("** the kernel, report this immediately to your system **\n"); 2243 pr_warn("** administrator! **\n"); 2244 pr_warn("** **\n"); 2245 pr_warn("** NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE **\n"); 2246 pr_warn("**********************************************************\n"); 2247 2248 return 0; 2249 } 2250 early_param("no_hash_pointers", no_hash_pointers_enable); 2251 2252 /* 2253 * Show a '%p' thing. A kernel extension is that the '%p' is followed 2254 * by an extra set of alphanumeric characters that are extended format 2255 * specifiers. 2256 * 2257 * Please update scripts/checkpatch.pl when adding/removing conversion 2258 * characters. (Search for "check for vsprintf extension"). 2259 * 2260 * Right now we handle: 2261 * 2262 * - 'S' For symbolic direct pointers (or function descriptors) with offset 2263 * - 's' For symbolic direct pointers (or function descriptors) without offset 2264 * - '[Ss]R' as above with __builtin_extract_return_addr() translation 2265 * - '[Ff]' %pf and %pF were obsoleted and later removed in favor of 2266 * %ps and %pS. Be careful when re-using these specifiers. 2267 * - 'B' For backtraced symbolic direct pointers with offset 2268 * - 'R' For decoded struct resource, e.g., [mem 0x0-0x1f 64bit pref] 2269 * - 'r' For raw struct resource, e.g., [mem 0x0-0x1f flags 0x201] 2270 * - 'b[l]' For a bitmap, the number of bits is determined by the field 2271 * width which must be explicitly specified either as part of the 2272 * format string '%32b[l]' or through '%*b[l]', [l] selects 2273 * range-list format instead of hex format 2274 * - 'M' For a 6-byte MAC address, it prints the address in the 2275 * usual colon-separated hex notation 2276 * - 'm' For a 6-byte MAC address, it prints the hex address without colons 2277 * - 'MF' For a 6-byte MAC FDDI address, it prints the address 2278 * with a dash-separated hex notation 2279 * - '[mM]R' For a 6-byte MAC address, Reverse order (Bluetooth) 2280 * - 'I' [46] for IPv4/IPv6 addresses printed in the usual way 2281 * IPv4 uses dot-separated decimal without leading 0's (1.2.3.4) 2282 * IPv6 uses colon separated network-order 16 bit hex with leading 0's 2283 * [S][pfs] 2284 * Generic IPv4/IPv6 address (struct sockaddr *) that falls back to 2285 * [4] or [6] and is able to print port [p], flowinfo [f], scope [s] 2286 * - 'i' [46] for 'raw' IPv4/IPv6 addresses 2287 * IPv6 omits the colons (01020304...0f) 2288 * IPv4 uses dot-separated decimal with leading 0's (010.123.045.006) 2289 * [S][pfs] 2290 * Generic IPv4/IPv6 address (struct sockaddr *) that falls back to 2291 * [4] or [6] and is able to print port [p], flowinfo [f], scope [s] 2292 * - '[Ii][4S][hnbl]' IPv4 addresses in host, network, big or little endian order 2293 * - 'I[6S]c' for IPv6 addresses printed as specified by 2294 * https://tools.ietf.org/html/rfc5952 2295 * - 'E[achnops]' For an escaped buffer, where rules are defined by combination 2296 * of the following flags (see string_escape_mem() for the 2297 * details): 2298 * a - ESCAPE_ANY 2299 * c - ESCAPE_SPECIAL 2300 * h - ESCAPE_HEX 2301 * n - ESCAPE_NULL 2302 * o - ESCAPE_OCTAL 2303 * p - ESCAPE_NP 2304 * s - ESCAPE_SPACE 2305 * By default ESCAPE_ANY_NP is used. 2306 * - 'U' For a 16 byte UUID/GUID, it prints the UUID/GUID in the form 2307 * "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx" 2308 * Options for %pU are: 2309 * b big endian lower case hex (default) 2310 * B big endian UPPER case hex 2311 * l little endian lower case hex 2312 * L little endian UPPER case hex 2313 * big endian output byte order is: 2314 * [0][1][2][3]-[4][5]-[6][7]-[8][9]-[10][11][12][13][14][15] 2315 * little endian output byte order is: 2316 * [3][2][1][0]-[5][4]-[7][6]-[8][9]-[10][11][12][13][14][15] 2317 * - 'V' For a struct va_format which contains a format string * and va_list *, 2318 * call vsnprintf(->format, *->va_list). 2319 * Implements a "recursive vsnprintf". 2320 * Do not use this feature without some mechanism to verify the 2321 * correctness of the format string and va_list arguments. 2322 * - 'K' For a kernel pointer that should be hidden from unprivileged users. 2323 * Use only for procfs, sysfs and similar files, not printk(); please 2324 * read the documentation (path below) first. 2325 * - 'NF' For a netdev_features_t 2326 * - '4cc' V4L2 or DRM FourCC code, with endianness and raw numerical value. 2327 * - 'h[CDN]' For a variable-length buffer, it prints it as a hex string with 2328 * a certain separator (' ' by default): 2329 * C colon 2330 * D dash 2331 * N no separator 2332 * The maximum supported length is 64 bytes of the input. Consider 2333 * to use print_hex_dump() for the larger input. 2334 * - 'a[pd]' For address types [p] phys_addr_t, [d] dma_addr_t and derivatives 2335 * (default assumed to be phys_addr_t, passed by reference) 2336 * - 'd[234]' For a dentry name (optionally 2-4 last components) 2337 * - 'D[234]' Same as 'd' but for a struct file 2338 * - 'g' For block_device name (gendisk + partition number) 2339 * - 't[RT][dt][r][s]' For time and date as represented by: 2340 * R struct rtc_time 2341 * T time64_t 2342 * - 'C' For a clock, it prints the name (Common Clock Framework) or address 2343 * (legacy clock framework) of the clock 2344 * - 'Cn' For a clock, it prints the name (Common Clock Framework) or address 2345 * (legacy clock framework) of the clock 2346 * - 'G' For flags to be printed as a collection of symbolic strings that would 2347 * construct the specific value. Supported flags given by option: 2348 * p page flags (see struct page) given as pointer to unsigned long 2349 * g gfp flags (GFP_* and __GFP_*) given as pointer to gfp_t 2350 * v vma flags (VM_*) given as pointer to unsigned long 2351 * - 'OF[fnpPcCF]' For a device tree object 2352 * Without any optional arguments prints the full_name 2353 * f device node full_name 2354 * n device node name 2355 * p device node phandle 2356 * P device node path spec (name + @unit) 2357 * F device node flags 2358 * c major compatible string 2359 * C full compatible string 2360 * - 'fw[fP]' For a firmware node (struct fwnode_handle) pointer 2361 * Without an option prints the full name of the node 2362 * f full name 2363 * P node name, including a possible unit address 2364 * - 'x' For printing the address unmodified. Equivalent to "%lx". 2365 * Please read the documentation (path below) before using! 2366 * - '[ku]s' For a BPF/tracing related format specifier, e.g. used out of 2367 * bpf_trace_printk() where [ku] prefix specifies either kernel (k) 2368 * or user (u) memory to probe, and: 2369 * s a string, equivalent to "%s" on direct vsnprintf() use 2370 * 2371 * ** When making changes please also update: 2372 * Documentation/core-api/printk-formats.rst 2373 * 2374 * Note: The default behaviour (unadorned %p) is to hash the address, 2375 * rendering it useful as a unique identifier. 2376 */ 2377 static noinline_for_stack 2378 char *pointer(const char *fmt, char *buf, char *end, void *ptr, 2379 struct printf_spec spec) 2380 { 2381 switch (*fmt) { 2382 case 'S': 2383 case 's': 2384 ptr = dereference_symbol_descriptor(ptr); 2385 fallthrough; 2386 case 'B': 2387 return symbol_string(buf, end, ptr, spec, fmt); 2388 case 'R': 2389 case 'r': 2390 return resource_string(buf, end, ptr, spec, fmt); 2391 case 'h': 2392 return hex_string(buf, end, ptr, spec, fmt); 2393 case 'b': 2394 switch (fmt[1]) { 2395 case 'l': 2396 return bitmap_list_string(buf, end, ptr, spec, fmt); 2397 default: 2398 return bitmap_string(buf, end, ptr, spec, fmt); 2399 } 2400 case 'M': /* Colon separated: 00:01:02:03:04:05 */ 2401 case 'm': /* Contiguous: 000102030405 */ 2402 /* [mM]F (FDDI) */ 2403 /* [mM]R (Reverse order; Bluetooth) */ 2404 return mac_address_string(buf, end, ptr, spec, fmt); 2405 case 'I': /* Formatted IP supported 2406 * 4: 1.2.3.4 2407 * 6: 0001:0203:...:0708 2408 * 6c: 1::708 or 1::1.2.3.4 2409 */ 2410 case 'i': /* Contiguous: 2411 * 4: 001.002.003.004 2412 * 6: 000102...0f 2413 */ 2414 return ip_addr_string(buf, end, ptr, spec, fmt); 2415 case 'E': 2416 return escaped_string(buf, end, ptr, spec, fmt); 2417 case 'U': 2418 return uuid_string(buf, end, ptr, spec, fmt); 2419 case 'V': 2420 return va_format(buf, end, ptr, spec, fmt); 2421 case 'K': 2422 return restricted_pointer(buf, end, ptr, spec); 2423 case 'N': 2424 return netdev_bits(buf, end, ptr, spec, fmt); 2425 case '4': 2426 return fourcc_string(buf, end, ptr, spec, fmt); 2427 case 'a': 2428 return address_val(buf, end, ptr, spec, fmt); 2429 case 'd': 2430 return dentry_name(buf, end, ptr, spec, fmt); 2431 case 't': 2432 return time_and_date(buf, end, ptr, spec, fmt); 2433 case 'C': 2434 return clock(buf, end, ptr, spec, fmt); 2435 case 'D': 2436 return file_dentry_name(buf, end, ptr, spec, fmt); 2437 #ifdef CONFIG_BLOCK 2438 case 'g': 2439 return bdev_name(buf, end, ptr, spec, fmt); 2440 #endif 2441 2442 case 'G': 2443 return flags_string(buf, end, ptr, spec, fmt); 2444 case 'O': 2445 return device_node_string(buf, end, ptr, spec, fmt + 1); 2446 case 'f': 2447 return fwnode_string(buf, end, ptr, spec, fmt + 1); 2448 case 'x': 2449 return pointer_string(buf, end, ptr, spec); 2450 case 'e': 2451 /* %pe with a non-ERR_PTR gets treated as plain %p */ 2452 if (!IS_ERR(ptr)) 2453 break; 2454 return err_ptr(buf, end, ptr, spec); 2455 case 'u': 2456 case 'k': 2457 switch (fmt[1]) { 2458 case 's': 2459 return string(buf, end, ptr, spec); 2460 default: 2461 return error_string(buf, end, "(einval)", spec); 2462 } 2463 } 2464 2465 /* 2466 * default is to _not_ leak addresses, so hash before printing, 2467 * unless no_hash_pointers is specified on the command line. 2468 */ 2469 if (unlikely(no_hash_pointers)) 2470 return pointer_string(buf, end, ptr, spec); 2471 else 2472 return ptr_to_id(buf, end, ptr, spec); 2473 } 2474 2475 /* 2476 * Helper function to decode printf style format. 2477 * Each call decode a token from the format and return the 2478 * number of characters read (or likely the delta where it wants 2479 * to go on the next call). 2480 * The decoded token is returned through the parameters 2481 * 2482 * 'h', 'l', or 'L' for integer fields 2483 * 'z' support added 23/7/1999 S.H. 2484 * 'z' changed to 'Z' --davidm 1/25/99 2485 * 'Z' changed to 'z' --adobriyan 2017-01-25 2486 * 't' added for ptrdiff_t 2487 * 2488 * @fmt: the format string 2489 * @type of the token returned 2490 * @flags: various flags such as +, -, # tokens.. 2491 * @field_width: overwritten width 2492 * @base: base of the number (octal, hex, ...) 2493 * @precision: precision of a number 2494 * @qualifier: qualifier of a number (long, size_t, ...) 2495 */ 2496 static noinline_for_stack 2497 int format_decode(const char *fmt, struct printf_spec *spec) 2498 { 2499 const char *start = fmt; 2500 char qualifier; 2501 2502 /* we finished early by reading the field width */ 2503 if (spec->type == FORMAT_TYPE_WIDTH) { 2504 if (spec->field_width < 0) { 2505 spec->field_width = -spec->field_width; 2506 spec->flags |= LEFT; 2507 } 2508 spec->type = FORMAT_TYPE_NONE; 2509 goto precision; 2510 } 2511 2512 /* we finished early by reading the precision */ 2513 if (spec->type == FORMAT_TYPE_PRECISION) { 2514 if (spec->precision < 0) 2515 spec->precision = 0; 2516 2517 spec->type = FORMAT_TYPE_NONE; 2518 goto qualifier; 2519 } 2520 2521 /* By default */ 2522 spec->type = FORMAT_TYPE_NONE; 2523 2524 for (; *fmt ; ++fmt) { 2525 if (*fmt == '%') 2526 break; 2527 } 2528 2529 /* Return the current non-format string */ 2530 if (fmt != start || !*fmt) 2531 return fmt - start; 2532 2533 /* Process flags */ 2534 spec->flags = 0; 2535 2536 while (1) { /* this also skips first '%' */ 2537 bool found = true; 2538 2539 ++fmt; 2540 2541 switch (*fmt) { 2542 case '-': spec->flags |= LEFT; break; 2543 case '+': spec->flags |= PLUS; break; 2544 case ' ': spec->flags |= SPACE; break; 2545 case '#': spec->flags |= SPECIAL; break; 2546 case '0': spec->flags |= ZEROPAD; break; 2547 default: found = false; 2548 } 2549 2550 if (!found) 2551 break; 2552 } 2553 2554 /* get field width */ 2555 spec->field_width = -1; 2556 2557 if (isdigit(*fmt)) 2558 spec->field_width = skip_atoi(&fmt); 2559 else if (*fmt == '*') { 2560 /* it's the next argument */ 2561 spec->type = FORMAT_TYPE_WIDTH; 2562 return ++fmt - start; 2563 } 2564 2565 precision: 2566 /* get the precision */ 2567 spec->precision = -1; 2568 if (*fmt == '.') { 2569 ++fmt; 2570 if (isdigit(*fmt)) { 2571 spec->precision = skip_atoi(&fmt); 2572 if (spec->precision < 0) 2573 spec->precision = 0; 2574 } else if (*fmt == '*') { 2575 /* it's the next argument */ 2576 spec->type = FORMAT_TYPE_PRECISION; 2577 return ++fmt - start; 2578 } 2579 } 2580 2581 qualifier: 2582 /* get the conversion qualifier */ 2583 qualifier = 0; 2584 if (*fmt == 'h' || _tolower(*fmt) == 'l' || 2585 *fmt == 'z' || *fmt == 't') { 2586 qualifier = *fmt++; 2587 if (unlikely(qualifier == *fmt)) { 2588 if (qualifier == 'l') { 2589 qualifier = 'L'; 2590 ++fmt; 2591 } else if (qualifier == 'h') { 2592 qualifier = 'H'; 2593 ++fmt; 2594 } 2595 } 2596 } 2597 2598 /* default base */ 2599 spec->base = 10; 2600 switch (*fmt) { 2601 case 'c': 2602 spec->type = FORMAT_TYPE_CHAR; 2603 return ++fmt - start; 2604 2605 case 's': 2606 spec->type = FORMAT_TYPE_STR; 2607 return ++fmt - start; 2608 2609 case 'p': 2610 spec->type = FORMAT_TYPE_PTR; 2611 return ++fmt - start; 2612 2613 case '%': 2614 spec->type = FORMAT_TYPE_PERCENT_CHAR; 2615 return ++fmt - start; 2616 2617 /* integer number formats - set up the flags and "break" */ 2618 case 'o': 2619 spec->base = 8; 2620 break; 2621 2622 case 'x': 2623 spec->flags |= SMALL; 2624 fallthrough; 2625 2626 case 'X': 2627 spec->base = 16; 2628 break; 2629 2630 case 'd': 2631 case 'i': 2632 spec->flags |= SIGN; 2633 break; 2634 case 'u': 2635 break; 2636 2637 case 'n': 2638 /* 2639 * Since %n poses a greater security risk than 2640 * utility, treat it as any other invalid or 2641 * unsupported format specifier. 2642 */ 2643 fallthrough; 2644 2645 default: 2646 WARN_ONCE(1, "Please remove unsupported %%%c in format string\n", *fmt); 2647 spec->type = FORMAT_TYPE_INVALID; 2648 return fmt - start; 2649 } 2650 2651 if (qualifier == 'L') 2652 spec->type = FORMAT_TYPE_LONG_LONG; 2653 else if (qualifier == 'l') { 2654 BUILD_BUG_ON(FORMAT_TYPE_ULONG + SIGN != FORMAT_TYPE_LONG); 2655 spec->type = FORMAT_TYPE_ULONG + (spec->flags & SIGN); 2656 } else if (qualifier == 'z') { 2657 spec->type = FORMAT_TYPE_SIZE_T; 2658 } else if (qualifier == 't') { 2659 spec->type = FORMAT_TYPE_PTRDIFF; 2660 } else if (qualifier == 'H') { 2661 BUILD_BUG_ON(FORMAT_TYPE_UBYTE + SIGN != FORMAT_TYPE_BYTE); 2662 spec->type = FORMAT_TYPE_UBYTE + (spec->flags & SIGN); 2663 } else if (qualifier == 'h') { 2664 BUILD_BUG_ON(FORMAT_TYPE_USHORT + SIGN != FORMAT_TYPE_SHORT); 2665 spec->type = FORMAT_TYPE_USHORT + (spec->flags & SIGN); 2666 } else { 2667 BUILD_BUG_ON(FORMAT_TYPE_UINT + SIGN != FORMAT_TYPE_INT); 2668 spec->type = FORMAT_TYPE_UINT + (spec->flags & SIGN); 2669 } 2670 2671 return ++fmt - start; 2672 } 2673 2674 static void 2675 set_field_width(struct printf_spec *spec, int width) 2676 { 2677 spec->field_width = width; 2678 if (WARN_ONCE(spec->field_width != width, "field width %d too large", width)) { 2679 spec->field_width = clamp(width, -FIELD_WIDTH_MAX, FIELD_WIDTH_MAX); 2680 } 2681 } 2682 2683 static void 2684 set_precision(struct printf_spec *spec, int prec) 2685 { 2686 spec->precision = prec; 2687 if (WARN_ONCE(spec->precision != prec, "precision %d too large", prec)) { 2688 spec->precision = clamp(prec, 0, PRECISION_MAX); 2689 } 2690 } 2691 2692 /** 2693 * vsnprintf - Format a string and place it in a buffer 2694 * @buf: The buffer to place the result into 2695 * @size: The size of the buffer, including the trailing null space 2696 * @fmt: The format string to use 2697 * @args: Arguments for the format string 2698 * 2699 * This function generally follows C99 vsnprintf, but has some 2700 * extensions and a few limitations: 2701 * 2702 * - ``%n`` is unsupported 2703 * - ``%p*`` is handled by pointer() 2704 * 2705 * See pointer() or Documentation/core-api/printk-formats.rst for more 2706 * extensive description. 2707 * 2708 * **Please update the documentation in both places when making changes** 2709 * 2710 * The return value is the number of characters which would 2711 * be generated for the given input, excluding the trailing 2712 * '\0', as per ISO C99. If you want to have the exact 2713 * number of characters written into @buf as return value 2714 * (not including the trailing '\0'), use vscnprintf(). If the 2715 * return is greater than or equal to @size, the resulting 2716 * string is truncated. 2717 * 2718 * If you're not already dealing with a va_list consider using snprintf(). 2719 */ 2720 int vsnprintf(char *buf, size_t size, const char *fmt, va_list args) 2721 { 2722 unsigned long long num; 2723 char *str, *end; 2724 struct printf_spec spec = {0}; 2725 2726 /* Reject out-of-range values early. Large positive sizes are 2727 used for unknown buffer sizes. */ 2728 if (WARN_ON_ONCE(size > INT_MAX)) 2729 return 0; 2730 2731 str = buf; 2732 end = buf + size; 2733 2734 /* Make sure end is always >= buf */ 2735 if (end < buf) { 2736 end = ((void *)-1); 2737 size = end - buf; 2738 } 2739 2740 while (*fmt) { 2741 const char *old_fmt = fmt; 2742 int read = format_decode(fmt, &spec); 2743 2744 fmt += read; 2745 2746 switch (spec.type) { 2747 case FORMAT_TYPE_NONE: { 2748 int copy = read; 2749 if (str < end) { 2750 if (copy > end - str) 2751 copy = end - str; 2752 memcpy(str, old_fmt, copy); 2753 } 2754 str += read; 2755 break; 2756 } 2757 2758 case FORMAT_TYPE_WIDTH: 2759 set_field_width(&spec, va_arg(args, int)); 2760 break; 2761 2762 case FORMAT_TYPE_PRECISION: 2763 set_precision(&spec, va_arg(args, int)); 2764 break; 2765 2766 case FORMAT_TYPE_CHAR: { 2767 char c; 2768 2769 if (!(spec.flags & LEFT)) { 2770 while (--spec.field_width > 0) { 2771 if (str < end) 2772 *str = ' '; 2773 ++str; 2774 2775 } 2776 } 2777 c = (unsigned char) va_arg(args, int); 2778 if (str < end) 2779 *str = c; 2780 ++str; 2781 while (--spec.field_width > 0) { 2782 if (str < end) 2783 *str = ' '; 2784 ++str; 2785 } 2786 break; 2787 } 2788 2789 case FORMAT_TYPE_STR: 2790 str = string(str, end, va_arg(args, char *), spec); 2791 break; 2792 2793 case FORMAT_TYPE_PTR: 2794 str = pointer(fmt, str, end, va_arg(args, void *), 2795 spec); 2796 while (isalnum(*fmt)) 2797 fmt++; 2798 break; 2799 2800 case FORMAT_TYPE_PERCENT_CHAR: 2801 if (str < end) 2802 *str = '%'; 2803 ++str; 2804 break; 2805 2806 case FORMAT_TYPE_INVALID: 2807 /* 2808 * Presumably the arguments passed gcc's type 2809 * checking, but there is no safe or sane way 2810 * for us to continue parsing the format and 2811 * fetching from the va_list; the remaining 2812 * specifiers and arguments would be out of 2813 * sync. 2814 */ 2815 goto out; 2816 2817 default: 2818 switch (spec.type) { 2819 case FORMAT_TYPE_LONG_LONG: 2820 num = va_arg(args, long long); 2821 break; 2822 case FORMAT_TYPE_ULONG: 2823 num = va_arg(args, unsigned long); 2824 break; 2825 case FORMAT_TYPE_LONG: 2826 num = va_arg(args, long); 2827 break; 2828 case FORMAT_TYPE_SIZE_T: 2829 if (spec.flags & SIGN) 2830 num = va_arg(args, ssize_t); 2831 else 2832 num = va_arg(args, size_t); 2833 break; 2834 case FORMAT_TYPE_PTRDIFF: 2835 num = va_arg(args, ptrdiff_t); 2836 break; 2837 case FORMAT_TYPE_UBYTE: 2838 num = (unsigned char) va_arg(args, int); 2839 break; 2840 case FORMAT_TYPE_BYTE: 2841 num = (signed char) va_arg(args, int); 2842 break; 2843 case FORMAT_TYPE_USHORT: 2844 num = (unsigned short) va_arg(args, int); 2845 break; 2846 case FORMAT_TYPE_SHORT: 2847 num = (short) va_arg(args, int); 2848 break; 2849 case FORMAT_TYPE_INT: 2850 num = (int) va_arg(args, int); 2851 break; 2852 default: 2853 num = va_arg(args, unsigned int); 2854 } 2855 2856 str = number(str, end, num, spec); 2857 } 2858 } 2859 2860 out: 2861 if (size > 0) { 2862 if (str < end) 2863 *str = '\0'; 2864 else 2865 end[-1] = '\0'; 2866 } 2867 2868 /* the trailing null byte doesn't count towards the total */ 2869 return str-buf; 2870 2871 } 2872 EXPORT_SYMBOL(vsnprintf); 2873 2874 /** 2875 * vscnprintf - Format a string and place it in a buffer 2876 * @buf: The buffer to place the result into 2877 * @size: The size of the buffer, including the trailing null space 2878 * @fmt: The format string to use 2879 * @args: Arguments for the format string 2880 * 2881 * The return value is the number of characters which have been written into 2882 * the @buf not including the trailing '\0'. If @size is == 0 the function 2883 * returns 0. 2884 * 2885 * If you're not already dealing with a va_list consider using scnprintf(). 2886 * 2887 * See the vsnprintf() documentation for format string extensions over C99. 2888 */ 2889 int vscnprintf(char *buf, size_t size, const char *fmt, va_list args) 2890 { 2891 int i; 2892 2893 i = vsnprintf(buf, size, fmt, args); 2894 2895 if (likely(i < size)) 2896 return i; 2897 if (size != 0) 2898 return size - 1; 2899 return 0; 2900 } 2901 EXPORT_SYMBOL(vscnprintf); 2902 2903 /** 2904 * snprintf - Format a string and place it in a buffer 2905 * @buf: The buffer to place the result into 2906 * @size: The size of the buffer, including the trailing null space 2907 * @fmt: The format string to use 2908 * @...: Arguments for the format string 2909 * 2910 * The return value is the number of characters which would be 2911 * generated for the given input, excluding the trailing null, 2912 * as per ISO C99. If the return is greater than or equal to 2913 * @size, the resulting string is truncated. 2914 * 2915 * See the vsnprintf() documentation for format string extensions over C99. 2916 */ 2917 int snprintf(char *buf, size_t size, const char *fmt, ...) 2918 { 2919 va_list args; 2920 int i; 2921 2922 va_start(args, fmt); 2923 i = vsnprintf(buf, size, fmt, args); 2924 va_end(args); 2925 2926 return i; 2927 } 2928 EXPORT_SYMBOL(snprintf); 2929 2930 /** 2931 * scnprintf - Format a string and place it in a buffer 2932 * @buf: The buffer to place the result into 2933 * @size: The size of the buffer, including the trailing null space 2934 * @fmt: The format string to use 2935 * @...: Arguments for the format string 2936 * 2937 * The return value is the number of characters written into @buf not including 2938 * the trailing '\0'. If @size is == 0 the function returns 0. 2939 */ 2940 2941 int scnprintf(char *buf, size_t size, const char *fmt, ...) 2942 { 2943 va_list args; 2944 int i; 2945 2946 va_start(args, fmt); 2947 i = vscnprintf(buf, size, fmt, args); 2948 va_end(args); 2949 2950 return i; 2951 } 2952 EXPORT_SYMBOL(scnprintf); 2953 2954 /** 2955 * vsprintf - Format a string and place it in a buffer 2956 * @buf: The buffer to place the result into 2957 * @fmt: The format string to use 2958 * @args: Arguments for the format string 2959 * 2960 * The function returns the number of characters written 2961 * into @buf. Use vsnprintf() or vscnprintf() in order to avoid 2962 * buffer overflows. 2963 * 2964 * If you're not already dealing with a va_list consider using sprintf(). 2965 * 2966 * See the vsnprintf() documentation for format string extensions over C99. 2967 */ 2968 int vsprintf(char *buf, const char *fmt, va_list args) 2969 { 2970 return vsnprintf(buf, INT_MAX, fmt, args); 2971 } 2972 EXPORT_SYMBOL(vsprintf); 2973 2974 /** 2975 * sprintf - Format a string and place it in a buffer 2976 * @buf: The buffer to place the result into 2977 * @fmt: The format string to use 2978 * @...: Arguments for the format string 2979 * 2980 * The function returns the number of characters written 2981 * into @buf. Use snprintf() or scnprintf() in order to avoid 2982 * buffer overflows. 2983 * 2984 * See the vsnprintf() documentation for format string extensions over C99. 2985 */ 2986 int sprintf(char *buf, const char *fmt, ...) 2987 { 2988 va_list args; 2989 int i; 2990 2991 va_start(args, fmt); 2992 i = vsnprintf(buf, INT_MAX, fmt, args); 2993 va_end(args); 2994 2995 return i; 2996 } 2997 EXPORT_SYMBOL(sprintf); 2998 2999 #ifdef CONFIG_BINARY_PRINTF 3000 /* 3001 * bprintf service: 3002 * vbin_printf() - VA arguments to binary data 3003 * bstr_printf() - Binary data to text string 3004 */ 3005 3006 /** 3007 * vbin_printf - Parse a format string and place args' binary value in a buffer 3008 * @bin_buf: The buffer to place args' binary value 3009 * @size: The size of the buffer(by words(32bits), not characters) 3010 * @fmt: The format string to use 3011 * @args: Arguments for the format string 3012 * 3013 * The format follows C99 vsnprintf, except %n is ignored, and its argument 3014 * is skipped. 3015 * 3016 * The return value is the number of words(32bits) which would be generated for 3017 * the given input. 3018 * 3019 * NOTE: 3020 * If the return value is greater than @size, the resulting bin_buf is NOT 3021 * valid for bstr_printf(). 3022 */ 3023 int vbin_printf(u32 *bin_buf, size_t size, const char *fmt, va_list args) 3024 { 3025 struct printf_spec spec = {0}; 3026 char *str, *end; 3027 int width; 3028 3029 str = (char *)bin_buf; 3030 end = (char *)(bin_buf + size); 3031 3032 #define save_arg(type) \ 3033 ({ \ 3034 unsigned long long value; \ 3035 if (sizeof(type) == 8) { \ 3036 unsigned long long val8; \ 3037 str = PTR_ALIGN(str, sizeof(u32)); \ 3038 val8 = va_arg(args, unsigned long long); \ 3039 if (str + sizeof(type) <= end) { \ 3040 *(u32 *)str = *(u32 *)&val8; \ 3041 *(u32 *)(str + 4) = *((u32 *)&val8 + 1); \ 3042 } \ 3043 value = val8; \ 3044 } else { \ 3045 unsigned int val4; \ 3046 str = PTR_ALIGN(str, sizeof(type)); \ 3047 val4 = va_arg(args, int); \ 3048 if (str + sizeof(type) <= end) \ 3049 *(typeof(type) *)str = (type)(long)val4; \ 3050 value = (unsigned long long)val4; \ 3051 } \ 3052 str += sizeof(type); \ 3053 value; \ 3054 }) 3055 3056 while (*fmt) { 3057 int read = format_decode(fmt, &spec); 3058 3059 fmt += read; 3060 3061 switch (spec.type) { 3062 case FORMAT_TYPE_NONE: 3063 case FORMAT_TYPE_PERCENT_CHAR: 3064 break; 3065 case FORMAT_TYPE_INVALID: 3066 goto out; 3067 3068 case FORMAT_TYPE_WIDTH: 3069 case FORMAT_TYPE_PRECISION: 3070 width = (int)save_arg(int); 3071 /* Pointers may require the width */ 3072 if (*fmt == 'p') 3073 set_field_width(&spec, width); 3074 break; 3075 3076 case FORMAT_TYPE_CHAR: 3077 save_arg(char); 3078 break; 3079 3080 case FORMAT_TYPE_STR: { 3081 const char *save_str = va_arg(args, char *); 3082 const char *err_msg; 3083 size_t len; 3084 3085 err_msg = check_pointer_msg(save_str); 3086 if (err_msg) 3087 save_str = err_msg; 3088 3089 len = strlen(save_str) + 1; 3090 if (str + len < end) 3091 memcpy(str, save_str, len); 3092 str += len; 3093 break; 3094 } 3095 3096 case FORMAT_TYPE_PTR: 3097 /* Dereferenced pointers must be done now */ 3098 switch (*fmt) { 3099 /* Dereference of functions is still OK */ 3100 case 'S': 3101 case 's': 3102 case 'x': 3103 case 'K': 3104 case 'e': 3105 save_arg(void *); 3106 break; 3107 default: 3108 if (!isalnum(*fmt)) { 3109 save_arg(void *); 3110 break; 3111 } 3112 str = pointer(fmt, str, end, va_arg(args, void *), 3113 spec); 3114 if (str + 1 < end) 3115 *str++ = '\0'; 3116 else 3117 end[-1] = '\0'; /* Must be nul terminated */ 3118 } 3119 /* skip all alphanumeric pointer suffixes */ 3120 while (isalnum(*fmt)) 3121 fmt++; 3122 break; 3123 3124 default: 3125 switch (spec.type) { 3126 3127 case FORMAT_TYPE_LONG_LONG: 3128 save_arg(long long); 3129 break; 3130 case FORMAT_TYPE_ULONG: 3131 case FORMAT_TYPE_LONG: 3132 save_arg(unsigned long); 3133 break; 3134 case FORMAT_TYPE_SIZE_T: 3135 save_arg(size_t); 3136 break; 3137 case FORMAT_TYPE_PTRDIFF: 3138 save_arg(ptrdiff_t); 3139 break; 3140 case FORMAT_TYPE_UBYTE: 3141 case FORMAT_TYPE_BYTE: 3142 save_arg(char); 3143 break; 3144 case FORMAT_TYPE_USHORT: 3145 case FORMAT_TYPE_SHORT: 3146 save_arg(short); 3147 break; 3148 default: 3149 save_arg(int); 3150 } 3151 } 3152 } 3153 3154 out: 3155 return (u32 *)(PTR_ALIGN(str, sizeof(u32))) - bin_buf; 3156 #undef save_arg 3157 } 3158 EXPORT_SYMBOL_GPL(vbin_printf); 3159 3160 /** 3161 * bstr_printf - Format a string from binary arguments and place it in a buffer 3162 * @buf: The buffer to place the result into 3163 * @size: The size of the buffer, including the trailing null space 3164 * @fmt: The format string to use 3165 * @bin_buf: Binary arguments for the format string 3166 * 3167 * This function like C99 vsnprintf, but the difference is that vsnprintf gets 3168 * arguments from stack, and bstr_printf gets arguments from @bin_buf which is 3169 * a binary buffer that generated by vbin_printf. 3170 * 3171 * The format follows C99 vsnprintf, but has some extensions: 3172 * see vsnprintf comment for details. 3173 * 3174 * The return value is the number of characters which would 3175 * be generated for the given input, excluding the trailing 3176 * '\0', as per ISO C99. If you want to have the exact 3177 * number of characters written into @buf as return value 3178 * (not including the trailing '\0'), use vscnprintf(). If the 3179 * return is greater than or equal to @size, the resulting 3180 * string is truncated. 3181 */ 3182 int bstr_printf(char *buf, size_t size, const char *fmt, const u32 *bin_buf) 3183 { 3184 struct printf_spec spec = {0}; 3185 char *str, *end; 3186 const char *args = (const char *)bin_buf; 3187 3188 if (WARN_ON_ONCE(size > INT_MAX)) 3189 return 0; 3190 3191 str = buf; 3192 end = buf + size; 3193 3194 #define get_arg(type) \ 3195 ({ \ 3196 typeof(type) value; \ 3197 if (sizeof(type) == 8) { \ 3198 args = PTR_ALIGN(args, sizeof(u32)); \ 3199 *(u32 *)&value = *(u32 *)args; \ 3200 *((u32 *)&value + 1) = *(u32 *)(args + 4); \ 3201 } else { \ 3202 args = PTR_ALIGN(args, sizeof(type)); \ 3203 value = *(typeof(type) *)args; \ 3204 } \ 3205 args += sizeof(type); \ 3206 value; \ 3207 }) 3208 3209 /* Make sure end is always >= buf */ 3210 if (end < buf) { 3211 end = ((void *)-1); 3212 size = end - buf; 3213 } 3214 3215 while (*fmt) { 3216 const char *old_fmt = fmt; 3217 int read = format_decode(fmt, &spec); 3218 3219 fmt += read; 3220 3221 switch (spec.type) { 3222 case FORMAT_TYPE_NONE: { 3223 int copy = read; 3224 if (str < end) { 3225 if (copy > end - str) 3226 copy = end - str; 3227 memcpy(str, old_fmt, copy); 3228 } 3229 str += read; 3230 break; 3231 } 3232 3233 case FORMAT_TYPE_WIDTH: 3234 set_field_width(&spec, get_arg(int)); 3235 break; 3236 3237 case FORMAT_TYPE_PRECISION: 3238 set_precision(&spec, get_arg(int)); 3239 break; 3240 3241 case FORMAT_TYPE_CHAR: { 3242 char c; 3243 3244 if (!(spec.flags & LEFT)) { 3245 while (--spec.field_width > 0) { 3246 if (str < end) 3247 *str = ' '; 3248 ++str; 3249 } 3250 } 3251 c = (unsigned char) get_arg(char); 3252 if (str < end) 3253 *str = c; 3254 ++str; 3255 while (--spec.field_width > 0) { 3256 if (str < end) 3257 *str = ' '; 3258 ++str; 3259 } 3260 break; 3261 } 3262 3263 case FORMAT_TYPE_STR: { 3264 const char *str_arg = args; 3265 args += strlen(str_arg) + 1; 3266 str = string(str, end, (char *)str_arg, spec); 3267 break; 3268 } 3269 3270 case FORMAT_TYPE_PTR: { 3271 bool process = false; 3272 int copy, len; 3273 /* Non function dereferences were already done */ 3274 switch (*fmt) { 3275 case 'S': 3276 case 's': 3277 case 'x': 3278 case 'K': 3279 case 'e': 3280 process = true; 3281 break; 3282 default: 3283 if (!isalnum(*fmt)) { 3284 process = true; 3285 break; 3286 } 3287 /* Pointer dereference was already processed */ 3288 if (str < end) { 3289 len = copy = strlen(args); 3290 if (copy > end - str) 3291 copy = end - str; 3292 memcpy(str, args, copy); 3293 str += len; 3294 args += len + 1; 3295 } 3296 } 3297 if (process) 3298 str = pointer(fmt, str, end, get_arg(void *), spec); 3299 3300 while (isalnum(*fmt)) 3301 fmt++; 3302 break; 3303 } 3304 3305 case FORMAT_TYPE_PERCENT_CHAR: 3306 if (str < end) 3307 *str = '%'; 3308 ++str; 3309 break; 3310 3311 case FORMAT_TYPE_INVALID: 3312 goto out; 3313 3314 default: { 3315 unsigned long long num; 3316 3317 switch (spec.type) { 3318 3319 case FORMAT_TYPE_LONG_LONG: 3320 num = get_arg(long long); 3321 break; 3322 case FORMAT_TYPE_ULONG: 3323 case FORMAT_TYPE_LONG: 3324 num = get_arg(unsigned long); 3325 break; 3326 case FORMAT_TYPE_SIZE_T: 3327 num = get_arg(size_t); 3328 break; 3329 case FORMAT_TYPE_PTRDIFF: 3330 num = get_arg(ptrdiff_t); 3331 break; 3332 case FORMAT_TYPE_UBYTE: 3333 num = get_arg(unsigned char); 3334 break; 3335 case FORMAT_TYPE_BYTE: 3336 num = get_arg(signed char); 3337 break; 3338 case FORMAT_TYPE_USHORT: 3339 num = get_arg(unsigned short); 3340 break; 3341 case FORMAT_TYPE_SHORT: 3342 num = get_arg(short); 3343 break; 3344 case FORMAT_TYPE_UINT: 3345 num = get_arg(unsigned int); 3346 break; 3347 default: 3348 num = get_arg(int); 3349 } 3350 3351 str = number(str, end, num, spec); 3352 } /* default: */ 3353 } /* switch(spec.type) */ 3354 } /* while(*fmt) */ 3355 3356 out: 3357 if (size > 0) { 3358 if (str < end) 3359 *str = '\0'; 3360 else 3361 end[-1] = '\0'; 3362 } 3363 3364 #undef get_arg 3365 3366 /* the trailing null byte doesn't count towards the total */ 3367 return str - buf; 3368 } 3369 EXPORT_SYMBOL_GPL(bstr_printf); 3370 3371 /** 3372 * bprintf - Parse a format string and place args' binary value in a buffer 3373 * @bin_buf: The buffer to place args' binary value 3374 * @size: The size of the buffer(by words(32bits), not characters) 3375 * @fmt: The format string to use 3376 * @...: Arguments for the format string 3377 * 3378 * The function returns the number of words(u32) written 3379 * into @bin_buf. 3380 */ 3381 int bprintf(u32 *bin_buf, size_t size, const char *fmt, ...) 3382 { 3383 va_list args; 3384 int ret; 3385 3386 va_start(args, fmt); 3387 ret = vbin_printf(bin_buf, size, fmt, args); 3388 va_end(args); 3389 3390 return ret; 3391 } 3392 EXPORT_SYMBOL_GPL(bprintf); 3393 3394 #endif /* CONFIG_BINARY_PRINTF */ 3395 3396 /** 3397 * vsscanf - Unformat a buffer into a list of arguments 3398 * @buf: input buffer 3399 * @fmt: format of buffer 3400 * @args: arguments 3401 */ 3402 int vsscanf(const char *buf, const char *fmt, va_list args) 3403 { 3404 const char *str = buf; 3405 char *next; 3406 char digit; 3407 int num = 0; 3408 u8 qualifier; 3409 unsigned int base; 3410 union { 3411 long long s; 3412 unsigned long long u; 3413 } val; 3414 s16 field_width; 3415 bool is_sign; 3416 3417 while (*fmt) { 3418 /* skip any white space in format */ 3419 /* white space in format matchs any amount of 3420 * white space, including none, in the input. 3421 */ 3422 if (isspace(*fmt)) { 3423 fmt = skip_spaces(++fmt); 3424 str = skip_spaces(str); 3425 } 3426 3427 /* anything that is not a conversion must match exactly */ 3428 if (*fmt != '%' && *fmt) { 3429 if (*fmt++ != *str++) 3430 break; 3431 continue; 3432 } 3433 3434 if (!*fmt) 3435 break; 3436 ++fmt; 3437 3438 /* skip this conversion. 3439 * advance both strings to next white space 3440 */ 3441 if (*fmt == '*') { 3442 if (!*str) 3443 break; 3444 while (!isspace(*fmt) && *fmt != '%' && *fmt) { 3445 /* '%*[' not yet supported, invalid format */ 3446 if (*fmt == '[') 3447 return num; 3448 fmt++; 3449 } 3450 while (!isspace(*str) && *str) 3451 str++; 3452 continue; 3453 } 3454 3455 /* get field width */ 3456 field_width = -1; 3457 if (isdigit(*fmt)) { 3458 field_width = skip_atoi(&fmt); 3459 if (field_width <= 0) 3460 break; 3461 } 3462 3463 /* get conversion qualifier */ 3464 qualifier = -1; 3465 if (*fmt == 'h' || _tolower(*fmt) == 'l' || 3466 *fmt == 'z') { 3467 qualifier = *fmt++; 3468 if (unlikely(qualifier == *fmt)) { 3469 if (qualifier == 'h') { 3470 qualifier = 'H'; 3471 fmt++; 3472 } else if (qualifier == 'l') { 3473 qualifier = 'L'; 3474 fmt++; 3475 } 3476 } 3477 } 3478 3479 if (!*fmt) 3480 break; 3481 3482 if (*fmt == 'n') { 3483 /* return number of characters read so far */ 3484 *va_arg(args, int *) = str - buf; 3485 ++fmt; 3486 continue; 3487 } 3488 3489 if (!*str) 3490 break; 3491 3492 base = 10; 3493 is_sign = false; 3494 3495 switch (*fmt++) { 3496 case 'c': 3497 { 3498 char *s = (char *)va_arg(args, char*); 3499 if (field_width == -1) 3500 field_width = 1; 3501 do { 3502 *s++ = *str++; 3503 } while (--field_width > 0 && *str); 3504 num++; 3505 } 3506 continue; 3507 case 's': 3508 { 3509 char *s = (char *)va_arg(args, char *); 3510 if (field_width == -1) 3511 field_width = SHRT_MAX; 3512 /* first, skip leading white space in buffer */ 3513 str = skip_spaces(str); 3514 3515 /* now copy until next white space */ 3516 while (*str && !isspace(*str) && field_width--) 3517 *s++ = *str++; 3518 *s = '\0'; 3519 num++; 3520 } 3521 continue; 3522 /* 3523 * Warning: This implementation of the '[' conversion specifier 3524 * deviates from its glibc counterpart in the following ways: 3525 * (1) It does NOT support ranges i.e. '-' is NOT a special 3526 * character 3527 * (2) It cannot match the closing bracket ']' itself 3528 * (3) A field width is required 3529 * (4) '%*[' (discard matching input) is currently not supported 3530 * 3531 * Example usage: 3532 * ret = sscanf("00:0a:95","%2[^:]:%2[^:]:%2[^:]", 3533 * buf1, buf2, buf3); 3534 * if (ret < 3) 3535 * // etc.. 3536 */ 3537 case '[': 3538 { 3539 char *s = (char *)va_arg(args, char *); 3540 DECLARE_BITMAP(set, 256) = {0}; 3541 unsigned int len = 0; 3542 bool negate = (*fmt == '^'); 3543 3544 /* field width is required */ 3545 if (field_width == -1) 3546 return num; 3547 3548 if (negate) 3549 ++fmt; 3550 3551 for ( ; *fmt && *fmt != ']'; ++fmt, ++len) 3552 set_bit((u8)*fmt, set); 3553 3554 /* no ']' or no character set found */ 3555 if (!*fmt || !len) 3556 return num; 3557 ++fmt; 3558 3559 if (negate) { 3560 bitmap_complement(set, set, 256); 3561 /* exclude null '\0' byte */ 3562 clear_bit(0, set); 3563 } 3564 3565 /* match must be non-empty */ 3566 if (!test_bit((u8)*str, set)) 3567 return num; 3568 3569 while (test_bit((u8)*str, set) && field_width--) 3570 *s++ = *str++; 3571 *s = '\0'; 3572 ++num; 3573 } 3574 continue; 3575 case 'o': 3576 base = 8; 3577 break; 3578 case 'x': 3579 case 'X': 3580 base = 16; 3581 break; 3582 case 'i': 3583 base = 0; 3584 fallthrough; 3585 case 'd': 3586 is_sign = true; 3587 fallthrough; 3588 case 'u': 3589 break; 3590 case '%': 3591 /* looking for '%' in str */ 3592 if (*str++ != '%') 3593 return num; 3594 continue; 3595 default: 3596 /* invalid format; stop here */ 3597 return num; 3598 } 3599 3600 /* have some sort of integer conversion. 3601 * first, skip white space in buffer. 3602 */ 3603 str = skip_spaces(str); 3604 3605 digit = *str; 3606 if (is_sign && digit == '-') { 3607 if (field_width == 1) 3608 break; 3609 3610 digit = *(str + 1); 3611 } 3612 3613 if (!digit 3614 || (base == 16 && !isxdigit(digit)) 3615 || (base == 10 && !isdigit(digit)) 3616 || (base == 8 && (!isdigit(digit) || digit > '7')) 3617 || (base == 0 && !isdigit(digit))) 3618 break; 3619 3620 if (is_sign) 3621 val.s = simple_strntoll(str, 3622 field_width >= 0 ? field_width : INT_MAX, 3623 &next, base); 3624 else 3625 val.u = simple_strntoull(str, 3626 field_width >= 0 ? field_width : INT_MAX, 3627 &next, base); 3628 3629 switch (qualifier) { 3630 case 'H': /* that's 'hh' in format */ 3631 if (is_sign) 3632 *va_arg(args, signed char *) = val.s; 3633 else 3634 *va_arg(args, unsigned char *) = val.u; 3635 break; 3636 case 'h': 3637 if (is_sign) 3638 *va_arg(args, short *) = val.s; 3639 else 3640 *va_arg(args, unsigned short *) = val.u; 3641 break; 3642 case 'l': 3643 if (is_sign) 3644 *va_arg(args, long *) = val.s; 3645 else 3646 *va_arg(args, unsigned long *) = val.u; 3647 break; 3648 case 'L': 3649 if (is_sign) 3650 *va_arg(args, long long *) = val.s; 3651 else 3652 *va_arg(args, unsigned long long *) = val.u; 3653 break; 3654 case 'z': 3655 *va_arg(args, size_t *) = val.u; 3656 break; 3657 default: 3658 if (is_sign) 3659 *va_arg(args, int *) = val.s; 3660 else 3661 *va_arg(args, unsigned int *) = val.u; 3662 break; 3663 } 3664 num++; 3665 3666 if (!next) 3667 break; 3668 str = next; 3669 } 3670 3671 return num; 3672 } 3673 EXPORT_SYMBOL(vsscanf); 3674 3675 /** 3676 * sscanf - Unformat a buffer into a list of arguments 3677 * @buf: input buffer 3678 * @fmt: formatting of buffer 3679 * @...: resulting arguments 3680 */ 3681 int sscanf(const char *buf, const char *fmt, ...) 3682 { 3683 va_list args; 3684 int i; 3685 3686 va_start(args, fmt); 3687 i = vsscanf(buf, fmt, args); 3688 va_end(args); 3689 3690 return i; 3691 } 3692 EXPORT_SYMBOL(sscanf); 3693