1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * linux/lib/vsprintf.c 4 * 5 * Copyright (C) 1991, 1992 Linus Torvalds 6 */ 7 8 /* vsprintf.c -- Lars Wirzenius & Linus Torvalds. */ 9 /* 10 * Wirzenius wrote this portably, Torvalds fucked it up :-) 11 */ 12 13 /* 14 * Fri Jul 13 2001 Crutcher Dunnavant <crutcher+kernel@datastacks.com> 15 * - changed to provide snprintf and vsnprintf functions 16 * So Feb 1 16:51:32 CET 2004 Juergen Quade <quade@hsnr.de> 17 * - scnprintf and vscnprintf 18 */ 19 20 #include <linux/stdarg.h> 21 #include <linux/build_bug.h> 22 #include <linux/clk.h> 23 #include <linux/clk-provider.h> 24 #include <linux/errname.h> 25 #include <linux/module.h> /* for KSYM_SYMBOL_LEN */ 26 #include <linux/types.h> 27 #include <linux/string.h> 28 #include <linux/ctype.h> 29 #include <linux/kernel.h> 30 #include <linux/kallsyms.h> 31 #include <linux/math64.h> 32 #include <linux/uaccess.h> 33 #include <linux/ioport.h> 34 #include <linux/dcache.h> 35 #include <linux/cred.h> 36 #include <linux/rtc.h> 37 #include <linux/time.h> 38 #include <linux/uuid.h> 39 #include <linux/of.h> 40 #include <net/addrconf.h> 41 #include <linux/siphash.h> 42 #include <linux/compiler.h> 43 #include <linux/property.h> 44 #ifdef CONFIG_BLOCK 45 #include <linux/blkdev.h> 46 #endif 47 48 #include "../mm/internal.h" /* For the trace_print_flags arrays */ 49 50 #include <asm/page.h> /* for PAGE_SIZE */ 51 #include <asm/byteorder.h> /* cpu_to_le16 */ 52 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 noinline 90 unsigned long long simple_strtoull(const char *cp, char **endp, unsigned int base) 91 { 92 return simple_strntoull(cp, INT_MAX, endp, base); 93 } 94 EXPORT_SYMBOL(simple_strtoull); 95 96 /** 97 * simple_strtoul - convert a string to an unsigned long 98 * @cp: The start of the string 99 * @endp: A pointer to the end of the parsed string will be placed here 100 * @base: The number base to use 101 * 102 * This function has caveats. Please use kstrtoul instead. 103 */ 104 unsigned long simple_strtoul(const char *cp, char **endp, unsigned int base) 105 { 106 return simple_strtoull(cp, endp, base); 107 } 108 EXPORT_SYMBOL(simple_strtoul); 109 110 /** 111 * simple_strtol - convert a string to a signed long 112 * @cp: The start of the string 113 * @endp: A pointer to the end of the parsed string will be placed here 114 * @base: The number base to use 115 * 116 * This function has caveats. Please use kstrtol instead. 117 */ 118 long simple_strtol(const char *cp, char **endp, unsigned int base) 119 { 120 if (*cp == '-') 121 return -simple_strtoul(cp + 1, endp, base); 122 123 return simple_strtoul(cp, endp, base); 124 } 125 EXPORT_SYMBOL(simple_strtol); 126 127 static long long simple_strntoll(const char *cp, size_t max_chars, char **endp, 128 unsigned int base) 129 { 130 /* 131 * simple_strntoull() safely handles receiving max_chars==0 in the 132 * case cp[0] == '-' && max_chars == 1. 133 * If max_chars == 0 we can drop through and pass it to simple_strntoull() 134 * and the content of *cp is irrelevant. 135 */ 136 if (*cp == '-' && max_chars > 0) 137 return -simple_strntoull(cp + 1, max_chars - 1, endp, base); 138 139 return simple_strntoull(cp, max_chars, endp, base); 140 } 141 142 /** 143 * simple_strtoll - convert a string to a signed long long 144 * @cp: The start of the string 145 * @endp: A pointer to the end of the parsed string will be placed here 146 * @base: The number base to use 147 * 148 * This function has caveats. Please use kstrtoll instead. 149 */ 150 long long simple_strtoll(const char *cp, char **endp, unsigned int base) 151 { 152 return simple_strntoll(cp, INT_MAX, endp, base); 153 } 154 EXPORT_SYMBOL(simple_strtoll); 155 156 static noinline_for_stack 157 int skip_atoi(const char **s) 158 { 159 int i = 0; 160 161 do { 162 i = i*10 + *((*s)++) - '0'; 163 } while (isdigit(**s)); 164 165 return i; 166 } 167 168 /* 169 * Decimal conversion is by far the most typical, and is used for 170 * /proc and /sys data. This directly impacts e.g. top performance 171 * with many processes running. We optimize it for speed by emitting 172 * two characters at a time, using a 200 byte lookup table. This 173 * roughly halves the number of multiplications compared to computing 174 * the digits one at a time. Implementation strongly inspired by the 175 * previous version, which in turn used ideas described at 176 * <http://www.cs.uiowa.edu/~jones/bcd/divide.html> (with permission 177 * from the author, Douglas W. Jones). 178 * 179 * It turns out there is precisely one 26 bit fixed-point 180 * approximation a of 64/100 for which x/100 == (x * (u64)a) >> 32 181 * holds for all x in [0, 10^8-1], namely a = 0x28f5c29. The actual 182 * range happens to be somewhat larger (x <= 1073741898), but that's 183 * irrelevant for our purpose. 184 * 185 * For dividing a number in the range [10^4, 10^6-1] by 100, we still 186 * need a 32x32->64 bit multiply, so we simply use the same constant. 187 * 188 * For dividing a number in the range [100, 10^4-1] by 100, there are 189 * several options. The simplest is (x * 0x147b) >> 19, which is valid 190 * for all x <= 43698. 191 */ 192 193 static const u16 decpair[100] = { 194 #define _(x) (__force u16) cpu_to_le16(((x % 10) | ((x / 10) << 8)) + 0x3030) 195 _( 0), _( 1), _( 2), _( 3), _( 4), _( 5), _( 6), _( 7), _( 8), _( 9), 196 _(10), _(11), _(12), _(13), _(14), _(15), _(16), _(17), _(18), _(19), 197 _(20), _(21), _(22), _(23), _(24), _(25), _(26), _(27), _(28), _(29), 198 _(30), _(31), _(32), _(33), _(34), _(35), _(36), _(37), _(38), _(39), 199 _(40), _(41), _(42), _(43), _(44), _(45), _(46), _(47), _(48), _(49), 200 _(50), _(51), _(52), _(53), _(54), _(55), _(56), _(57), _(58), _(59), 201 _(60), _(61), _(62), _(63), _(64), _(65), _(66), _(67), _(68), _(69), 202 _(70), _(71), _(72), _(73), _(74), _(75), _(76), _(77), _(78), _(79), 203 _(80), _(81), _(82), _(83), _(84), _(85), _(86), _(87), _(88), _(89), 204 _(90), _(91), _(92), _(93), _(94), _(95), _(96), _(97), _(98), _(99), 205 #undef _ 206 }; 207 208 /* 209 * This will print a single '0' even if r == 0, since we would 210 * immediately jump to out_r where two 0s would be written but only 211 * one of them accounted for in buf. This is needed by ip4_string 212 * below. All other callers pass a non-zero value of r. 213 */ 214 static noinline_for_stack 215 char *put_dec_trunc8(char *buf, unsigned r) 216 { 217 unsigned q; 218 219 /* 1 <= r < 10^8 */ 220 if (r < 100) 221 goto out_r; 222 223 /* 100 <= r < 10^8 */ 224 q = (r * (u64)0x28f5c29) >> 32; 225 *((u16 *)buf) = decpair[r - 100*q]; 226 buf += 2; 227 228 /* 1 <= q < 10^6 */ 229 if (q < 100) 230 goto out_q; 231 232 /* 100 <= q < 10^6 */ 233 r = (q * (u64)0x28f5c29) >> 32; 234 *((u16 *)buf) = decpair[q - 100*r]; 235 buf += 2; 236 237 /* 1 <= r < 10^4 */ 238 if (r < 100) 239 goto out_r; 240 241 /* 100 <= r < 10^4 */ 242 q = (r * 0x147b) >> 19; 243 *((u16 *)buf) = decpair[r - 100*q]; 244 buf += 2; 245 out_q: 246 /* 1 <= q < 100 */ 247 r = q; 248 out_r: 249 /* 1 <= r < 100 */ 250 *((u16 *)buf) = decpair[r]; 251 buf += r < 10 ? 1 : 2; 252 return buf; 253 } 254 255 #if BITS_PER_LONG == 64 && BITS_PER_LONG_LONG == 64 256 static noinline_for_stack 257 char *put_dec_full8(char *buf, unsigned r) 258 { 259 unsigned q; 260 261 /* 0 <= r < 10^8 */ 262 q = (r * (u64)0x28f5c29) >> 32; 263 *((u16 *)buf) = decpair[r - 100*q]; 264 buf += 2; 265 266 /* 0 <= q < 10^6 */ 267 r = (q * (u64)0x28f5c29) >> 32; 268 *((u16 *)buf) = decpair[q - 100*r]; 269 buf += 2; 270 271 /* 0 <= r < 10^4 */ 272 q = (r * 0x147b) >> 19; 273 *((u16 *)buf) = decpair[r - 100*q]; 274 buf += 2; 275 276 /* 0 <= q < 100 */ 277 *((u16 *)buf) = decpair[q]; 278 buf += 2; 279 return buf; 280 } 281 282 static noinline_for_stack 283 char *put_dec(char *buf, unsigned long long n) 284 { 285 if (n >= 100*1000*1000) 286 buf = put_dec_full8(buf, do_div(n, 100*1000*1000)); 287 /* 1 <= n <= 1.6e11 */ 288 if (n >= 100*1000*1000) 289 buf = put_dec_full8(buf, do_div(n, 100*1000*1000)); 290 /* 1 <= n < 1e8 */ 291 return put_dec_trunc8(buf, n); 292 } 293 294 #elif BITS_PER_LONG == 32 && BITS_PER_LONG_LONG == 64 295 296 static void 297 put_dec_full4(char *buf, unsigned r) 298 { 299 unsigned q; 300 301 /* 0 <= r < 10^4 */ 302 q = (r * 0x147b) >> 19; 303 *((u16 *)buf) = decpair[r - 100*q]; 304 buf += 2; 305 /* 0 <= q < 100 */ 306 *((u16 *)buf) = decpair[q]; 307 } 308 309 /* 310 * Call put_dec_full4 on x % 10000, return x / 10000. 311 * The approximation x/10000 == (x * 0x346DC5D7) >> 43 312 * holds for all x < 1,128,869,999. The largest value this 313 * helper will ever be asked to convert is 1,125,520,955. 314 * (second call in the put_dec code, assuming n is all-ones). 315 */ 316 static noinline_for_stack 317 unsigned put_dec_helper4(char *buf, unsigned x) 318 { 319 uint32_t q = (x * (uint64_t)0x346DC5D7) >> 43; 320 321 put_dec_full4(buf, x - q * 10000); 322 return q; 323 } 324 325 /* Based on code by Douglas W. Jones found at 326 * <http://www.cs.uiowa.edu/~jones/bcd/decimal.html#sixtyfour> 327 * (with permission from the author). 328 * Performs no 64-bit division and hence should be fast on 32-bit machines. 329 */ 330 static 331 char *put_dec(char *buf, unsigned long long n) 332 { 333 uint32_t d3, d2, d1, q, h; 334 335 if (n < 100*1000*1000) 336 return put_dec_trunc8(buf, n); 337 338 d1 = ((uint32_t)n >> 16); /* implicit "& 0xffff" */ 339 h = (n >> 32); 340 d2 = (h ) & 0xffff; 341 d3 = (h >> 16); /* implicit "& 0xffff" */ 342 343 /* n = 2^48 d3 + 2^32 d2 + 2^16 d1 + d0 344 = 281_4749_7671_0656 d3 + 42_9496_7296 d2 + 6_5536 d1 + d0 */ 345 q = 656 * d3 + 7296 * d2 + 5536 * d1 + ((uint32_t)n & 0xffff); 346 q = put_dec_helper4(buf, q); 347 348 q += 7671 * d3 + 9496 * d2 + 6 * d1; 349 q = put_dec_helper4(buf+4, q); 350 351 q += 4749 * d3 + 42 * d2; 352 q = put_dec_helper4(buf+8, q); 353 354 q += 281 * d3; 355 buf += 12; 356 if (q) 357 buf = put_dec_trunc8(buf, q); 358 else while (buf[-1] == '0') 359 --buf; 360 361 return buf; 362 } 363 364 #endif 365 366 /* 367 * Convert passed number to decimal string. 368 * Returns the length of string. On buffer overflow, returns 0. 369 * 370 * If speed is not important, use snprintf(). It's easy to read the code. 371 */ 372 int num_to_str(char *buf, int size, unsigned long long num, unsigned int width) 373 { 374 /* put_dec requires 2-byte alignment of the buffer. */ 375 char tmp[sizeof(num) * 3] __aligned(2); 376 int idx, len; 377 378 /* put_dec() may work incorrectly for num = 0 (generate "", not "0") */ 379 if (num <= 9) { 380 tmp[0] = '0' + num; 381 len = 1; 382 } else { 383 len = put_dec(tmp, num) - tmp; 384 } 385 386 if (len > size || width > size) 387 return 0; 388 389 if (width > len) { 390 width = width - len; 391 for (idx = 0; idx < width; idx++) 392 buf[idx] = ' '; 393 } else { 394 width = 0; 395 } 396 397 for (idx = 0; idx < len; ++idx) 398 buf[idx + width] = tmp[len - idx - 1]; 399 400 return len + width; 401 } 402 403 #define SIGN 1 /* unsigned/signed, must be 1 */ 404 #define LEFT 2 /* left justified */ 405 #define PLUS 4 /* show plus */ 406 #define SPACE 8 /* space if plus */ 407 #define ZEROPAD 16 /* pad with zero, must be 16 == '0' - ' ' */ 408 #define SMALL 32 /* use lowercase in hex (must be 32 == 0x20) */ 409 #define SPECIAL 64 /* prefix hex with "0x", octal with "0" */ 410 411 static_assert(ZEROPAD == ('0' - ' ')); 412 static_assert(SMALL == ' '); 413 414 enum format_type { 415 FORMAT_TYPE_NONE, /* Just a string part */ 416 FORMAT_TYPE_WIDTH, 417 FORMAT_TYPE_PRECISION, 418 FORMAT_TYPE_CHAR, 419 FORMAT_TYPE_STR, 420 FORMAT_TYPE_PTR, 421 FORMAT_TYPE_PERCENT_CHAR, 422 FORMAT_TYPE_INVALID, 423 FORMAT_TYPE_LONG_LONG, 424 FORMAT_TYPE_ULONG, 425 FORMAT_TYPE_LONG, 426 FORMAT_TYPE_UBYTE, 427 FORMAT_TYPE_BYTE, 428 FORMAT_TYPE_USHORT, 429 FORMAT_TYPE_SHORT, 430 FORMAT_TYPE_UINT, 431 FORMAT_TYPE_INT, 432 FORMAT_TYPE_SIZE_T, 433 FORMAT_TYPE_PTRDIFF 434 }; 435 436 struct printf_spec { 437 unsigned int type:8; /* format_type enum */ 438 signed int field_width:24; /* width of output field */ 439 unsigned int flags:8; /* flags to number() */ 440 unsigned int base:8; /* number base, 8, 10 or 16 only */ 441 signed int precision:16; /* # of digits/chars */ 442 } __packed; 443 static_assert(sizeof(struct printf_spec) == 8); 444 445 #define FIELD_WIDTH_MAX ((1 << 23) - 1) 446 #define PRECISION_MAX ((1 << 15) - 1) 447 448 static noinline_for_stack 449 char *number(char *buf, char *end, unsigned long long num, 450 struct printf_spec spec) 451 { 452 /* put_dec requires 2-byte alignment of the buffer. */ 453 char tmp[3 * sizeof(num)] __aligned(2); 454 char sign; 455 char locase; 456 int need_pfx = ((spec.flags & SPECIAL) && spec.base != 10); 457 int i; 458 bool is_zero = num == 0LL; 459 int field_width = spec.field_width; 460 int precision = spec.precision; 461 462 /* locase = 0 or 0x20. ORing digits or letters with 'locase' 463 * produces same digits or (maybe lowercased) letters */ 464 locase = (spec.flags & SMALL); 465 if (spec.flags & LEFT) 466 spec.flags &= ~ZEROPAD; 467 sign = 0; 468 if (spec.flags & SIGN) { 469 if ((signed long long)num < 0) { 470 sign = '-'; 471 num = -(signed long long)num; 472 field_width--; 473 } else if (spec.flags & PLUS) { 474 sign = '+'; 475 field_width--; 476 } else if (spec.flags & SPACE) { 477 sign = ' '; 478 field_width--; 479 } 480 } 481 if (need_pfx) { 482 if (spec.base == 16) 483 field_width -= 2; 484 else if (!is_zero) 485 field_width--; 486 } 487 488 /* generate full string in tmp[], in reverse order */ 489 i = 0; 490 if (num < spec.base) 491 tmp[i++] = hex_asc_upper[num] | locase; 492 else if (spec.base != 10) { /* 8 or 16 */ 493 int mask = spec.base - 1; 494 int shift = 3; 495 496 if (spec.base == 16) 497 shift = 4; 498 do { 499 tmp[i++] = (hex_asc_upper[((unsigned char)num) & mask] | locase); 500 num >>= shift; 501 } while (num); 502 } else { /* base 10 */ 503 i = put_dec(tmp, num) - tmp; 504 } 505 506 /* printing 100 using %2d gives "100", not "00" */ 507 if (i > precision) 508 precision = i; 509 /* leading space padding */ 510 field_width -= precision; 511 if (!(spec.flags & (ZEROPAD | LEFT))) { 512 while (--field_width >= 0) { 513 if (buf < end) 514 *buf = ' '; 515 ++buf; 516 } 517 } 518 /* sign */ 519 if (sign) { 520 if (buf < end) 521 *buf = sign; 522 ++buf; 523 } 524 /* "0x" / "0" prefix */ 525 if (need_pfx) { 526 if (spec.base == 16 || !is_zero) { 527 if (buf < end) 528 *buf = '0'; 529 ++buf; 530 } 531 if (spec.base == 16) { 532 if (buf < end) 533 *buf = ('X' | locase); 534 ++buf; 535 } 536 } 537 /* zero or space padding */ 538 if (!(spec.flags & LEFT)) { 539 char c = ' ' + (spec.flags & ZEROPAD); 540 541 while (--field_width >= 0) { 542 if (buf < end) 543 *buf = c; 544 ++buf; 545 } 546 } 547 /* hmm even more zero padding? */ 548 while (i <= --precision) { 549 if (buf < end) 550 *buf = '0'; 551 ++buf; 552 } 553 /* actual digits of result */ 554 while (--i >= 0) { 555 if (buf < end) 556 *buf = tmp[i]; 557 ++buf; 558 } 559 /* trailing space padding */ 560 while (--field_width >= 0) { 561 if (buf < end) 562 *buf = ' '; 563 ++buf; 564 } 565 566 return buf; 567 } 568 569 static noinline_for_stack 570 char *special_hex_number(char *buf, char *end, unsigned long long num, int size) 571 { 572 struct printf_spec spec; 573 574 spec.type = FORMAT_TYPE_PTR; 575 spec.field_width = 2 + 2 * size; /* 0x + hex */ 576 spec.flags = SPECIAL | SMALL | ZEROPAD; 577 spec.base = 16; 578 spec.precision = -1; 579 580 return number(buf, end, num, spec); 581 } 582 583 static void move_right(char *buf, char *end, unsigned len, unsigned spaces) 584 { 585 size_t size; 586 if (buf >= end) /* nowhere to put anything */ 587 return; 588 size = end - buf; 589 if (size <= spaces) { 590 memset(buf, ' ', size); 591 return; 592 } 593 if (len) { 594 if (len > size - spaces) 595 len = size - spaces; 596 memmove(buf + spaces, buf, len); 597 } 598 memset(buf, ' ', spaces); 599 } 600 601 /* 602 * Handle field width padding for a string. 603 * @buf: current buffer position 604 * @n: length of string 605 * @end: end of output buffer 606 * @spec: for field width and flags 607 * Returns: new buffer position after padding. 608 */ 609 static noinline_for_stack 610 char *widen_string(char *buf, int n, char *end, struct printf_spec spec) 611 { 612 unsigned spaces; 613 614 if (likely(n >= spec.field_width)) 615 return buf; 616 /* we want to pad the sucker */ 617 spaces = spec.field_width - n; 618 if (!(spec.flags & LEFT)) { 619 move_right(buf - n, end, n, spaces); 620 return buf + spaces; 621 } 622 while (spaces--) { 623 if (buf < end) 624 *buf = ' '; 625 ++buf; 626 } 627 return buf; 628 } 629 630 /* Handle string from a well known address. */ 631 static char *string_nocheck(char *buf, char *end, const char *s, 632 struct printf_spec spec) 633 { 634 int len = 0; 635 int lim = spec.precision; 636 637 while (lim--) { 638 char c = *s++; 639 if (!c) 640 break; 641 if (buf < end) 642 *buf = c; 643 ++buf; 644 ++len; 645 } 646 return widen_string(buf, len, end, spec); 647 } 648 649 static char *err_ptr(char *buf, char *end, void *ptr, 650 struct printf_spec spec) 651 { 652 int err = PTR_ERR(ptr); 653 const char *sym = errname(err); 654 655 if (sym) 656 return string_nocheck(buf, end, sym, spec); 657 658 /* 659 * Somebody passed ERR_PTR(-1234) or some other non-existing 660 * Efoo - or perhaps CONFIG_SYMBOLIC_ERRNAME=n. Fall back to 661 * printing it as its decimal representation. 662 */ 663 spec.flags |= SIGN; 664 spec.base = 10; 665 return number(buf, end, err, spec); 666 } 667 668 /* Be careful: error messages must fit into the given buffer. */ 669 static char *error_string(char *buf, char *end, const char *s, 670 struct printf_spec spec) 671 { 672 /* 673 * Hard limit to avoid a completely insane messages. It actually 674 * works pretty well because most error messages are in 675 * the many pointer format modifiers. 676 */ 677 if (spec.precision == -1) 678 spec.precision = 2 * sizeof(void *); 679 680 return string_nocheck(buf, end, s, spec); 681 } 682 683 /* 684 * Do not call any complex external code here. Nested printk()/vsprintf() 685 * might cause infinite loops. Failures might break printk() and would 686 * be hard to debug. 687 */ 688 static const char *check_pointer_msg(const void *ptr) 689 { 690 if (!ptr) 691 return "(null)"; 692 693 if ((unsigned long)ptr < PAGE_SIZE || IS_ERR_VALUE(ptr)) 694 return "(efault)"; 695 696 return NULL; 697 } 698 699 static int check_pointer(char **buf, char *end, const void *ptr, 700 struct printf_spec spec) 701 { 702 const char *err_msg; 703 704 err_msg = check_pointer_msg(ptr); 705 if (err_msg) { 706 *buf = error_string(*buf, end, err_msg, spec); 707 return -EFAULT; 708 } 709 710 return 0; 711 } 712 713 static noinline_for_stack 714 char *string(char *buf, char *end, const char *s, 715 struct printf_spec spec) 716 { 717 if (check_pointer(&buf, end, s, spec)) 718 return buf; 719 720 return string_nocheck(buf, end, s, spec); 721 } 722 723 static char *pointer_string(char *buf, char *end, 724 const void *ptr, 725 struct printf_spec spec) 726 { 727 spec.base = 16; 728 spec.flags |= SMALL; 729 if (spec.field_width == -1) { 730 spec.field_width = 2 * sizeof(ptr); 731 spec.flags |= ZEROPAD; 732 } 733 734 return number(buf, end, (unsigned long int)ptr, spec); 735 } 736 737 /* Make pointers available for printing early in the boot sequence. */ 738 static int debug_boot_weak_hash __ro_after_init; 739 740 static int __init debug_boot_weak_hash_enable(char *str) 741 { 742 debug_boot_weak_hash = 1; 743 pr_info("debug_boot_weak_hash enabled\n"); 744 return 0; 745 } 746 early_param("debug_boot_weak_hash", debug_boot_weak_hash_enable); 747 748 static DEFINE_STATIC_KEY_TRUE(not_filled_random_ptr_key); 749 static siphash_key_t ptr_key __read_mostly; 750 751 static void enable_ptr_key_workfn(struct work_struct *work) 752 { 753 get_random_bytes(&ptr_key, sizeof(ptr_key)); 754 /* Needs to run from preemptible context */ 755 static_branch_disable(¬_filled_random_ptr_key); 756 } 757 758 static DECLARE_WORK(enable_ptr_key_work, enable_ptr_key_workfn); 759 760 static void fill_random_ptr_key(struct random_ready_callback *unused) 761 { 762 /* This may be in an interrupt handler. */ 763 queue_work(system_unbound_wq, &enable_ptr_key_work); 764 } 765 766 static struct random_ready_callback random_ready = { 767 .func = fill_random_ptr_key 768 }; 769 770 static int __init initialize_ptr_random(void) 771 { 772 int key_size = sizeof(ptr_key); 773 int ret; 774 775 /* Use hw RNG if available. */ 776 if (get_random_bytes_arch(&ptr_key, key_size) == key_size) { 777 static_branch_disable(¬_filled_random_ptr_key); 778 return 0; 779 } 780 781 ret = add_random_ready_callback(&random_ready); 782 if (!ret) { 783 return 0; 784 } else if (ret == -EALREADY) { 785 /* This is in preemptible context */ 786 enable_ptr_key_workfn(&enable_ptr_key_work); 787 return 0; 788 } 789 790 return ret; 791 } 792 early_initcall(initialize_ptr_random); 793 794 /* Maps a pointer to a 32 bit unique identifier. */ 795 static inline int __ptr_to_hashval(const void *ptr, unsigned long *hashval_out) 796 { 797 unsigned long hashval; 798 799 if (static_branch_unlikely(¬_filled_random_ptr_key)) 800 return -EAGAIN; 801 802 #ifdef CONFIG_64BIT 803 hashval = (unsigned long)siphash_1u64((u64)ptr, &ptr_key); 804 /* 805 * Mask off the first 32 bits, this makes explicit that we have 806 * modified the address (and 32 bits is plenty for a unique ID). 807 */ 808 hashval = hashval & 0xffffffff; 809 #else 810 hashval = (unsigned long)siphash_1u32((u32)ptr, &ptr_key); 811 #endif 812 *hashval_out = hashval; 813 return 0; 814 } 815 816 int ptr_to_hashval(const void *ptr, unsigned long *hashval_out) 817 { 818 return __ptr_to_hashval(ptr, hashval_out); 819 } 820 821 static char *ptr_to_id(char *buf, char *end, const void *ptr, 822 struct printf_spec spec) 823 { 824 const char *str = sizeof(ptr) == 8 ? "(____ptrval____)" : "(ptrval)"; 825 unsigned long hashval; 826 int ret; 827 828 /* 829 * Print the real pointer value for NULL and error pointers, 830 * as they are not actual addresses. 831 */ 832 if (IS_ERR_OR_NULL(ptr)) 833 return pointer_string(buf, end, ptr, spec); 834 835 /* When debugging early boot use non-cryptographically secure hash. */ 836 if (unlikely(debug_boot_weak_hash)) { 837 hashval = hash_long((unsigned long)ptr, 32); 838 return pointer_string(buf, end, (const void *)hashval, spec); 839 } 840 841 ret = __ptr_to_hashval(ptr, &hashval); 842 if (ret) { 843 spec.field_width = 2 * sizeof(ptr); 844 /* string length must be less than default_width */ 845 return error_string(buf, end, str, spec); 846 } 847 848 return pointer_string(buf, end, (const void *)hashval, spec); 849 } 850 851 int kptr_restrict __read_mostly; 852 853 static noinline_for_stack 854 char *restricted_pointer(char *buf, char *end, const void *ptr, 855 struct printf_spec spec) 856 { 857 switch (kptr_restrict) { 858 case 0: 859 /* Handle as %p, hash and do _not_ leak addresses. */ 860 return ptr_to_id(buf, end, ptr, spec); 861 case 1: { 862 const struct cred *cred; 863 864 /* 865 * kptr_restrict==1 cannot be used in IRQ context 866 * because its test for CAP_SYSLOG would be meaningless. 867 */ 868 if (in_irq() || in_serving_softirq() || in_nmi()) { 869 if (spec.field_width == -1) 870 spec.field_width = 2 * sizeof(ptr); 871 return error_string(buf, end, "pK-error", spec); 872 } 873 874 /* 875 * Only print the real pointer value if the current 876 * process has CAP_SYSLOG and is running with the 877 * same credentials it started with. This is because 878 * access to files is checked at open() time, but %pK 879 * checks permission at read() time. We don't want to 880 * leak pointer values if a binary opens a file using 881 * %pK and then elevates privileges before reading it. 882 */ 883 cred = current_cred(); 884 if (!has_capability_noaudit(current, CAP_SYSLOG) || 885 !uid_eq(cred->euid, cred->uid) || 886 !gid_eq(cred->egid, cred->gid)) 887 ptr = NULL; 888 break; 889 } 890 case 2: 891 default: 892 /* Always print 0's for %pK */ 893 ptr = NULL; 894 break; 895 } 896 897 return pointer_string(buf, end, ptr, spec); 898 } 899 900 static noinline_for_stack 901 char *dentry_name(char *buf, char *end, const struct dentry *d, struct printf_spec spec, 902 const char *fmt) 903 { 904 const char *array[4], *s; 905 const struct dentry *p; 906 int depth; 907 int i, n; 908 909 switch (fmt[1]) { 910 case '2': case '3': case '4': 911 depth = fmt[1] - '0'; 912 break; 913 default: 914 depth = 1; 915 } 916 917 rcu_read_lock(); 918 for (i = 0; i < depth; i++, d = p) { 919 if (check_pointer(&buf, end, d, spec)) { 920 rcu_read_unlock(); 921 return buf; 922 } 923 924 p = READ_ONCE(d->d_parent); 925 array[i] = READ_ONCE(d->d_name.name); 926 if (p == d) { 927 if (i) 928 array[i] = ""; 929 i++; 930 break; 931 } 932 } 933 s = array[--i]; 934 for (n = 0; n != spec.precision; n++, buf++) { 935 char c = *s++; 936 if (!c) { 937 if (!i) 938 break; 939 c = '/'; 940 s = array[--i]; 941 } 942 if (buf < end) 943 *buf = c; 944 } 945 rcu_read_unlock(); 946 return widen_string(buf, n, end, spec); 947 } 948 949 static noinline_for_stack 950 char *file_dentry_name(char *buf, char *end, const struct file *f, 951 struct printf_spec spec, const char *fmt) 952 { 953 if (check_pointer(&buf, end, f, spec)) 954 return buf; 955 956 return dentry_name(buf, end, f->f_path.dentry, spec, fmt); 957 } 958 #ifdef CONFIG_BLOCK 959 static noinline_for_stack 960 char *bdev_name(char *buf, char *end, struct block_device *bdev, 961 struct printf_spec spec, const char *fmt) 962 { 963 struct gendisk *hd; 964 965 if (check_pointer(&buf, end, bdev, spec)) 966 return buf; 967 968 hd = bdev->bd_disk; 969 buf = string(buf, end, hd->disk_name, spec); 970 if (bdev->bd_partno) { 971 if (isdigit(hd->disk_name[strlen(hd->disk_name)-1])) { 972 if (buf < end) 973 *buf = 'p'; 974 buf++; 975 } 976 buf = number(buf, end, bdev->bd_partno, spec); 977 } 978 return buf; 979 } 980 #endif 981 982 static noinline_for_stack 983 char *symbol_string(char *buf, char *end, void *ptr, 984 struct printf_spec spec, const char *fmt) 985 { 986 unsigned long value; 987 #ifdef CONFIG_KALLSYMS 988 char sym[KSYM_SYMBOL_LEN]; 989 #endif 990 991 if (fmt[1] == 'R') 992 ptr = __builtin_extract_return_addr(ptr); 993 value = (unsigned long)ptr; 994 995 #ifdef CONFIG_KALLSYMS 996 if (*fmt == 'B' && fmt[1] == 'b') 997 sprint_backtrace_build_id(sym, value); 998 else if (*fmt == 'B') 999 sprint_backtrace(sym, value); 1000 else if (*fmt == 'S' && (fmt[1] == 'b' || (fmt[1] == 'R' && fmt[2] == 'b'))) 1001 sprint_symbol_build_id(sym, value); 1002 else if (*fmt != 's') 1003 sprint_symbol(sym, value); 1004 else 1005 sprint_symbol_no_offset(sym, value); 1006 1007 return string_nocheck(buf, end, sym, spec); 1008 #else 1009 return special_hex_number(buf, end, value, sizeof(void *)); 1010 #endif 1011 } 1012 1013 static const struct printf_spec default_str_spec = { 1014 .field_width = -1, 1015 .precision = -1, 1016 }; 1017 1018 static const struct printf_spec default_flag_spec = { 1019 .base = 16, 1020 .precision = -1, 1021 .flags = SPECIAL | SMALL, 1022 }; 1023 1024 static const struct printf_spec default_dec_spec = { 1025 .base = 10, 1026 .precision = -1, 1027 }; 1028 1029 static const struct printf_spec default_dec02_spec = { 1030 .base = 10, 1031 .field_width = 2, 1032 .precision = -1, 1033 .flags = ZEROPAD, 1034 }; 1035 1036 static const struct printf_spec default_dec04_spec = { 1037 .base = 10, 1038 .field_width = 4, 1039 .precision = -1, 1040 .flags = ZEROPAD, 1041 }; 1042 1043 static noinline_for_stack 1044 char *resource_string(char *buf, char *end, struct resource *res, 1045 struct printf_spec spec, const char *fmt) 1046 { 1047 #ifndef IO_RSRC_PRINTK_SIZE 1048 #define IO_RSRC_PRINTK_SIZE 6 1049 #endif 1050 1051 #ifndef MEM_RSRC_PRINTK_SIZE 1052 #define MEM_RSRC_PRINTK_SIZE 10 1053 #endif 1054 static const struct printf_spec io_spec = { 1055 .base = 16, 1056 .field_width = IO_RSRC_PRINTK_SIZE, 1057 .precision = -1, 1058 .flags = SPECIAL | SMALL | ZEROPAD, 1059 }; 1060 static const struct printf_spec mem_spec = { 1061 .base = 16, 1062 .field_width = MEM_RSRC_PRINTK_SIZE, 1063 .precision = -1, 1064 .flags = SPECIAL | SMALL | ZEROPAD, 1065 }; 1066 static const struct printf_spec bus_spec = { 1067 .base = 16, 1068 .field_width = 2, 1069 .precision = -1, 1070 .flags = SMALL | ZEROPAD, 1071 }; 1072 static const struct printf_spec str_spec = { 1073 .field_width = -1, 1074 .precision = 10, 1075 .flags = LEFT, 1076 }; 1077 1078 /* 32-bit res (sizeof==4): 10 chars in dec, 10 in hex ("0x" + 8) 1079 * 64-bit res (sizeof==8): 20 chars in dec, 18 in hex ("0x" + 16) */ 1080 #define RSRC_BUF_SIZE ((2 * sizeof(resource_size_t)) + 4) 1081 #define FLAG_BUF_SIZE (2 * sizeof(res->flags)) 1082 #define DECODED_BUF_SIZE sizeof("[mem - 64bit pref window disabled]") 1083 #define RAW_BUF_SIZE sizeof("[mem - flags 0x]") 1084 char sym[max(2*RSRC_BUF_SIZE + DECODED_BUF_SIZE, 1085 2*RSRC_BUF_SIZE + FLAG_BUF_SIZE + RAW_BUF_SIZE)]; 1086 1087 char *p = sym, *pend = sym + sizeof(sym); 1088 int decode = (fmt[0] == 'R') ? 1 : 0; 1089 const struct printf_spec *specp; 1090 1091 if (check_pointer(&buf, end, res, spec)) 1092 return buf; 1093 1094 *p++ = '['; 1095 if (res->flags & IORESOURCE_IO) { 1096 p = string_nocheck(p, pend, "io ", str_spec); 1097 specp = &io_spec; 1098 } else if (res->flags & IORESOURCE_MEM) { 1099 p = string_nocheck(p, pend, "mem ", str_spec); 1100 specp = &mem_spec; 1101 } else if (res->flags & IORESOURCE_IRQ) { 1102 p = string_nocheck(p, pend, "irq ", str_spec); 1103 specp = &default_dec_spec; 1104 } else if (res->flags & IORESOURCE_DMA) { 1105 p = string_nocheck(p, pend, "dma ", str_spec); 1106 specp = &default_dec_spec; 1107 } else if (res->flags & IORESOURCE_BUS) { 1108 p = string_nocheck(p, pend, "bus ", str_spec); 1109 specp = &bus_spec; 1110 } else { 1111 p = string_nocheck(p, pend, "??? ", str_spec); 1112 specp = &mem_spec; 1113 decode = 0; 1114 } 1115 if (decode && res->flags & IORESOURCE_UNSET) { 1116 p = string_nocheck(p, pend, "size ", str_spec); 1117 p = number(p, pend, resource_size(res), *specp); 1118 } else { 1119 p = number(p, pend, res->start, *specp); 1120 if (res->start != res->end) { 1121 *p++ = '-'; 1122 p = number(p, pend, res->end, *specp); 1123 } 1124 } 1125 if (decode) { 1126 if (res->flags & IORESOURCE_MEM_64) 1127 p = string_nocheck(p, pend, " 64bit", str_spec); 1128 if (res->flags & IORESOURCE_PREFETCH) 1129 p = string_nocheck(p, pend, " pref", str_spec); 1130 if (res->flags & IORESOURCE_WINDOW) 1131 p = string_nocheck(p, pend, " window", str_spec); 1132 if (res->flags & IORESOURCE_DISABLED) 1133 p = string_nocheck(p, pend, " disabled", str_spec); 1134 } else { 1135 p = string_nocheck(p, pend, " flags ", str_spec); 1136 p = number(p, pend, res->flags, default_flag_spec); 1137 } 1138 *p++ = ']'; 1139 *p = '\0'; 1140 1141 return string_nocheck(buf, end, sym, spec); 1142 } 1143 1144 static noinline_for_stack 1145 char *hex_string(char *buf, char *end, u8 *addr, struct printf_spec spec, 1146 const char *fmt) 1147 { 1148 int i, len = 1; /* if we pass '%ph[CDN]', field width remains 1149 negative value, fallback to the default */ 1150 char separator; 1151 1152 if (spec.field_width == 0) 1153 /* nothing to print */ 1154 return buf; 1155 1156 if (check_pointer(&buf, end, addr, spec)) 1157 return buf; 1158 1159 switch (fmt[1]) { 1160 case 'C': 1161 separator = ':'; 1162 break; 1163 case 'D': 1164 separator = '-'; 1165 break; 1166 case 'N': 1167 separator = 0; 1168 break; 1169 default: 1170 separator = ' '; 1171 break; 1172 } 1173 1174 if (spec.field_width > 0) 1175 len = min_t(int, spec.field_width, 64); 1176 1177 for (i = 0; i < len; ++i) { 1178 if (buf < end) 1179 *buf = hex_asc_hi(addr[i]); 1180 ++buf; 1181 if (buf < end) 1182 *buf = hex_asc_lo(addr[i]); 1183 ++buf; 1184 1185 if (separator && i != len - 1) { 1186 if (buf < end) 1187 *buf = separator; 1188 ++buf; 1189 } 1190 } 1191 1192 return buf; 1193 } 1194 1195 static noinline_for_stack 1196 char *bitmap_string(char *buf, char *end, unsigned long *bitmap, 1197 struct printf_spec spec, const char *fmt) 1198 { 1199 const int CHUNKSZ = 32; 1200 int nr_bits = max_t(int, spec.field_width, 0); 1201 int i, chunksz; 1202 bool first = true; 1203 1204 if (check_pointer(&buf, end, bitmap, spec)) 1205 return buf; 1206 1207 /* reused to print numbers */ 1208 spec = (struct printf_spec){ .flags = SMALL | ZEROPAD, .base = 16 }; 1209 1210 chunksz = nr_bits & (CHUNKSZ - 1); 1211 if (chunksz == 0) 1212 chunksz = CHUNKSZ; 1213 1214 i = ALIGN(nr_bits, CHUNKSZ) - CHUNKSZ; 1215 for (; i >= 0; i -= CHUNKSZ) { 1216 u32 chunkmask, val; 1217 int word, bit; 1218 1219 chunkmask = ((1ULL << chunksz) - 1); 1220 word = i / BITS_PER_LONG; 1221 bit = i % BITS_PER_LONG; 1222 val = (bitmap[word] >> bit) & chunkmask; 1223 1224 if (!first) { 1225 if (buf < end) 1226 *buf = ','; 1227 buf++; 1228 } 1229 first = false; 1230 1231 spec.field_width = DIV_ROUND_UP(chunksz, 4); 1232 buf = number(buf, end, val, spec); 1233 1234 chunksz = CHUNKSZ; 1235 } 1236 return buf; 1237 } 1238 1239 static noinline_for_stack 1240 char *bitmap_list_string(char *buf, char *end, unsigned long *bitmap, 1241 struct printf_spec spec, const char *fmt) 1242 { 1243 int nr_bits = max_t(int, spec.field_width, 0); 1244 /* current bit is 'cur', most recently seen range is [rbot, rtop] */ 1245 int cur, rbot, rtop; 1246 bool first = true; 1247 1248 if (check_pointer(&buf, end, bitmap, spec)) 1249 return buf; 1250 1251 rbot = cur = find_first_bit(bitmap, nr_bits); 1252 while (cur < nr_bits) { 1253 rtop = cur; 1254 cur = find_next_bit(bitmap, nr_bits, cur + 1); 1255 if (cur < nr_bits && cur <= rtop + 1) 1256 continue; 1257 1258 if (!first) { 1259 if (buf < end) 1260 *buf = ','; 1261 buf++; 1262 } 1263 first = false; 1264 1265 buf = number(buf, end, rbot, default_dec_spec); 1266 if (rbot < rtop) { 1267 if (buf < end) 1268 *buf = '-'; 1269 buf++; 1270 1271 buf = number(buf, end, rtop, default_dec_spec); 1272 } 1273 1274 rbot = cur; 1275 } 1276 return buf; 1277 } 1278 1279 static noinline_for_stack 1280 char *mac_address_string(char *buf, char *end, u8 *addr, 1281 struct printf_spec spec, const char *fmt) 1282 { 1283 char mac_addr[sizeof("xx:xx:xx:xx:xx:xx")]; 1284 char *p = mac_addr; 1285 int i; 1286 char separator; 1287 bool reversed = false; 1288 1289 if (check_pointer(&buf, end, addr, spec)) 1290 return buf; 1291 1292 switch (fmt[1]) { 1293 case 'F': 1294 separator = '-'; 1295 break; 1296 1297 case 'R': 1298 reversed = true; 1299 fallthrough; 1300 1301 default: 1302 separator = ':'; 1303 break; 1304 } 1305 1306 for (i = 0; i < 6; i++) { 1307 if (reversed) 1308 p = hex_byte_pack(p, addr[5 - i]); 1309 else 1310 p = hex_byte_pack(p, addr[i]); 1311 1312 if (fmt[0] == 'M' && i != 5) 1313 *p++ = separator; 1314 } 1315 *p = '\0'; 1316 1317 return string_nocheck(buf, end, mac_addr, spec); 1318 } 1319 1320 static noinline_for_stack 1321 char *ip4_string(char *p, const u8 *addr, const char *fmt) 1322 { 1323 int i; 1324 bool leading_zeros = (fmt[0] == 'i'); 1325 int index; 1326 int step; 1327 1328 switch (fmt[2]) { 1329 case 'h': 1330 #ifdef __BIG_ENDIAN 1331 index = 0; 1332 step = 1; 1333 #else 1334 index = 3; 1335 step = -1; 1336 #endif 1337 break; 1338 case 'l': 1339 index = 3; 1340 step = -1; 1341 break; 1342 case 'n': 1343 case 'b': 1344 default: 1345 index = 0; 1346 step = 1; 1347 break; 1348 } 1349 for (i = 0; i < 4; i++) { 1350 char temp[4] __aligned(2); /* hold each IP quad in reverse order */ 1351 int digits = put_dec_trunc8(temp, addr[index]) - temp; 1352 if (leading_zeros) { 1353 if (digits < 3) 1354 *p++ = '0'; 1355 if (digits < 2) 1356 *p++ = '0'; 1357 } 1358 /* reverse the digits in the quad */ 1359 while (digits--) 1360 *p++ = temp[digits]; 1361 if (i < 3) 1362 *p++ = '.'; 1363 index += step; 1364 } 1365 *p = '\0'; 1366 1367 return p; 1368 } 1369 1370 static noinline_for_stack 1371 char *ip6_compressed_string(char *p, const char *addr) 1372 { 1373 int i, j, range; 1374 unsigned char zerolength[8]; 1375 int longest = 1; 1376 int colonpos = -1; 1377 u16 word; 1378 u8 hi, lo; 1379 bool needcolon = false; 1380 bool useIPv4; 1381 struct in6_addr in6; 1382 1383 memcpy(&in6, addr, sizeof(struct in6_addr)); 1384 1385 useIPv4 = ipv6_addr_v4mapped(&in6) || ipv6_addr_is_isatap(&in6); 1386 1387 memset(zerolength, 0, sizeof(zerolength)); 1388 1389 if (useIPv4) 1390 range = 6; 1391 else 1392 range = 8; 1393 1394 /* find position of longest 0 run */ 1395 for (i = 0; i < range; i++) { 1396 for (j = i; j < range; j++) { 1397 if (in6.s6_addr16[j] != 0) 1398 break; 1399 zerolength[i]++; 1400 } 1401 } 1402 for (i = 0; i < range; i++) { 1403 if (zerolength[i] > longest) { 1404 longest = zerolength[i]; 1405 colonpos = i; 1406 } 1407 } 1408 if (longest == 1) /* don't compress a single 0 */ 1409 colonpos = -1; 1410 1411 /* emit address */ 1412 for (i = 0; i < range; i++) { 1413 if (i == colonpos) { 1414 if (needcolon || i == 0) 1415 *p++ = ':'; 1416 *p++ = ':'; 1417 needcolon = false; 1418 i += longest - 1; 1419 continue; 1420 } 1421 if (needcolon) { 1422 *p++ = ':'; 1423 needcolon = false; 1424 } 1425 /* hex u16 without leading 0s */ 1426 word = ntohs(in6.s6_addr16[i]); 1427 hi = word >> 8; 1428 lo = word & 0xff; 1429 if (hi) { 1430 if (hi > 0x0f) 1431 p = hex_byte_pack(p, hi); 1432 else 1433 *p++ = hex_asc_lo(hi); 1434 p = hex_byte_pack(p, lo); 1435 } 1436 else if (lo > 0x0f) 1437 p = hex_byte_pack(p, lo); 1438 else 1439 *p++ = hex_asc_lo(lo); 1440 needcolon = true; 1441 } 1442 1443 if (useIPv4) { 1444 if (needcolon) 1445 *p++ = ':'; 1446 p = ip4_string(p, &in6.s6_addr[12], "I4"); 1447 } 1448 *p = '\0'; 1449 1450 return p; 1451 } 1452 1453 static noinline_for_stack 1454 char *ip6_string(char *p, const char *addr, const char *fmt) 1455 { 1456 int i; 1457 1458 for (i = 0; i < 8; i++) { 1459 p = hex_byte_pack(p, *addr++); 1460 p = hex_byte_pack(p, *addr++); 1461 if (fmt[0] == 'I' && i != 7) 1462 *p++ = ':'; 1463 } 1464 *p = '\0'; 1465 1466 return p; 1467 } 1468 1469 static noinline_for_stack 1470 char *ip6_addr_string(char *buf, char *end, const u8 *addr, 1471 struct printf_spec spec, const char *fmt) 1472 { 1473 char ip6_addr[sizeof("xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255")]; 1474 1475 if (fmt[0] == 'I' && fmt[2] == 'c') 1476 ip6_compressed_string(ip6_addr, addr); 1477 else 1478 ip6_string(ip6_addr, addr, fmt); 1479 1480 return string_nocheck(buf, end, ip6_addr, spec); 1481 } 1482 1483 static noinline_for_stack 1484 char *ip4_addr_string(char *buf, char *end, const u8 *addr, 1485 struct printf_spec spec, const char *fmt) 1486 { 1487 char ip4_addr[sizeof("255.255.255.255")]; 1488 1489 ip4_string(ip4_addr, addr, fmt); 1490 1491 return string_nocheck(buf, end, ip4_addr, spec); 1492 } 1493 1494 static noinline_for_stack 1495 char *ip6_addr_string_sa(char *buf, char *end, const struct sockaddr_in6 *sa, 1496 struct printf_spec spec, const char *fmt) 1497 { 1498 bool have_p = false, have_s = false, have_f = false, have_c = false; 1499 char ip6_addr[sizeof("[xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255]") + 1500 sizeof(":12345") + sizeof("/123456789") + 1501 sizeof("%1234567890")]; 1502 char *p = ip6_addr, *pend = ip6_addr + sizeof(ip6_addr); 1503 const u8 *addr = (const u8 *) &sa->sin6_addr; 1504 char fmt6[2] = { fmt[0], '6' }; 1505 u8 off = 0; 1506 1507 fmt++; 1508 while (isalpha(*++fmt)) { 1509 switch (*fmt) { 1510 case 'p': 1511 have_p = true; 1512 break; 1513 case 'f': 1514 have_f = true; 1515 break; 1516 case 's': 1517 have_s = true; 1518 break; 1519 case 'c': 1520 have_c = true; 1521 break; 1522 } 1523 } 1524 1525 if (have_p || have_s || have_f) { 1526 *p = '['; 1527 off = 1; 1528 } 1529 1530 if (fmt6[0] == 'I' && have_c) 1531 p = ip6_compressed_string(ip6_addr + off, addr); 1532 else 1533 p = ip6_string(ip6_addr + off, addr, fmt6); 1534 1535 if (have_p || have_s || have_f) 1536 *p++ = ']'; 1537 1538 if (have_p) { 1539 *p++ = ':'; 1540 p = number(p, pend, ntohs(sa->sin6_port), spec); 1541 } 1542 if (have_f) { 1543 *p++ = '/'; 1544 p = number(p, pend, ntohl(sa->sin6_flowinfo & 1545 IPV6_FLOWINFO_MASK), spec); 1546 } 1547 if (have_s) { 1548 *p++ = '%'; 1549 p = number(p, pend, sa->sin6_scope_id, spec); 1550 } 1551 *p = '\0'; 1552 1553 return string_nocheck(buf, end, ip6_addr, spec); 1554 } 1555 1556 static noinline_for_stack 1557 char *ip4_addr_string_sa(char *buf, char *end, const struct sockaddr_in *sa, 1558 struct printf_spec spec, const char *fmt) 1559 { 1560 bool have_p = false; 1561 char *p, ip4_addr[sizeof("255.255.255.255") + sizeof(":12345")]; 1562 char *pend = ip4_addr + sizeof(ip4_addr); 1563 const u8 *addr = (const u8 *) &sa->sin_addr.s_addr; 1564 char fmt4[3] = { fmt[0], '4', 0 }; 1565 1566 fmt++; 1567 while (isalpha(*++fmt)) { 1568 switch (*fmt) { 1569 case 'p': 1570 have_p = true; 1571 break; 1572 case 'h': 1573 case 'l': 1574 case 'n': 1575 case 'b': 1576 fmt4[2] = *fmt; 1577 break; 1578 } 1579 } 1580 1581 p = ip4_string(ip4_addr, addr, fmt4); 1582 if (have_p) { 1583 *p++ = ':'; 1584 p = number(p, pend, ntohs(sa->sin_port), spec); 1585 } 1586 *p = '\0'; 1587 1588 return string_nocheck(buf, end, ip4_addr, spec); 1589 } 1590 1591 static noinline_for_stack 1592 char *ip_addr_string(char *buf, char *end, const void *ptr, 1593 struct printf_spec spec, const char *fmt) 1594 { 1595 char *err_fmt_msg; 1596 1597 if (check_pointer(&buf, end, ptr, spec)) 1598 return buf; 1599 1600 switch (fmt[1]) { 1601 case '6': 1602 return ip6_addr_string(buf, end, ptr, spec, fmt); 1603 case '4': 1604 return ip4_addr_string(buf, end, ptr, spec, fmt); 1605 case 'S': { 1606 const union { 1607 struct sockaddr raw; 1608 struct sockaddr_in v4; 1609 struct sockaddr_in6 v6; 1610 } *sa = ptr; 1611 1612 switch (sa->raw.sa_family) { 1613 case AF_INET: 1614 return ip4_addr_string_sa(buf, end, &sa->v4, spec, fmt); 1615 case AF_INET6: 1616 return ip6_addr_string_sa(buf, end, &sa->v6, spec, fmt); 1617 default: 1618 return error_string(buf, end, "(einval)", spec); 1619 }} 1620 } 1621 1622 err_fmt_msg = fmt[0] == 'i' ? "(%pi?)" : "(%pI?)"; 1623 return error_string(buf, end, err_fmt_msg, spec); 1624 } 1625 1626 static noinline_for_stack 1627 char *escaped_string(char *buf, char *end, u8 *addr, struct printf_spec spec, 1628 const char *fmt) 1629 { 1630 bool found = true; 1631 int count = 1; 1632 unsigned int flags = 0; 1633 int len; 1634 1635 if (spec.field_width == 0) 1636 return buf; /* nothing to print */ 1637 1638 if (check_pointer(&buf, end, addr, spec)) 1639 return buf; 1640 1641 do { 1642 switch (fmt[count++]) { 1643 case 'a': 1644 flags |= ESCAPE_ANY; 1645 break; 1646 case 'c': 1647 flags |= ESCAPE_SPECIAL; 1648 break; 1649 case 'h': 1650 flags |= ESCAPE_HEX; 1651 break; 1652 case 'n': 1653 flags |= ESCAPE_NULL; 1654 break; 1655 case 'o': 1656 flags |= ESCAPE_OCTAL; 1657 break; 1658 case 'p': 1659 flags |= ESCAPE_NP; 1660 break; 1661 case 's': 1662 flags |= ESCAPE_SPACE; 1663 break; 1664 default: 1665 found = false; 1666 break; 1667 } 1668 } while (found); 1669 1670 if (!flags) 1671 flags = ESCAPE_ANY_NP; 1672 1673 len = spec.field_width < 0 ? 1 : spec.field_width; 1674 1675 /* 1676 * string_escape_mem() writes as many characters as it can to 1677 * the given buffer, and returns the total size of the output 1678 * had the buffer been big enough. 1679 */ 1680 buf += string_escape_mem(addr, len, buf, buf < end ? end - buf : 0, flags, NULL); 1681 1682 return buf; 1683 } 1684 1685 static char *va_format(char *buf, char *end, struct va_format *va_fmt, 1686 struct printf_spec spec, const char *fmt) 1687 { 1688 va_list va; 1689 1690 if (check_pointer(&buf, end, va_fmt, spec)) 1691 return buf; 1692 1693 va_copy(va, *va_fmt->va); 1694 buf += vsnprintf(buf, end > buf ? end - buf : 0, va_fmt->fmt, va); 1695 va_end(va); 1696 1697 return buf; 1698 } 1699 1700 static noinline_for_stack 1701 char *uuid_string(char *buf, char *end, const u8 *addr, 1702 struct printf_spec spec, const char *fmt) 1703 { 1704 char uuid[UUID_STRING_LEN + 1]; 1705 char *p = uuid; 1706 int i; 1707 const u8 *index = uuid_index; 1708 bool uc = false; 1709 1710 if (check_pointer(&buf, end, addr, spec)) 1711 return buf; 1712 1713 switch (*(++fmt)) { 1714 case 'L': 1715 uc = true; 1716 fallthrough; 1717 case 'l': 1718 index = guid_index; 1719 break; 1720 case 'B': 1721 uc = true; 1722 break; 1723 } 1724 1725 for (i = 0; i < 16; i++) { 1726 if (uc) 1727 p = hex_byte_pack_upper(p, addr[index[i]]); 1728 else 1729 p = hex_byte_pack(p, addr[index[i]]); 1730 switch (i) { 1731 case 3: 1732 case 5: 1733 case 7: 1734 case 9: 1735 *p++ = '-'; 1736 break; 1737 } 1738 } 1739 1740 *p = 0; 1741 1742 return string_nocheck(buf, end, uuid, spec); 1743 } 1744 1745 static noinline_for_stack 1746 char *netdev_bits(char *buf, char *end, const void *addr, 1747 struct printf_spec spec, const char *fmt) 1748 { 1749 unsigned long long num; 1750 int size; 1751 1752 if (check_pointer(&buf, end, addr, spec)) 1753 return buf; 1754 1755 switch (fmt[1]) { 1756 case 'F': 1757 num = *(const netdev_features_t *)addr; 1758 size = sizeof(netdev_features_t); 1759 break; 1760 default: 1761 return error_string(buf, end, "(%pN?)", spec); 1762 } 1763 1764 return special_hex_number(buf, end, num, size); 1765 } 1766 1767 static noinline_for_stack 1768 char *fourcc_string(char *buf, char *end, const u32 *fourcc, 1769 struct printf_spec spec, const char *fmt) 1770 { 1771 char output[sizeof("0123 little-endian (0x01234567)")]; 1772 char *p = output; 1773 unsigned int i; 1774 u32 val; 1775 1776 if (fmt[1] != 'c' || fmt[2] != 'c') 1777 return error_string(buf, end, "(%p4?)", spec); 1778 1779 if (check_pointer(&buf, end, fourcc, spec)) 1780 return buf; 1781 1782 val = *fourcc & ~BIT(31); 1783 1784 for (i = 0; i < sizeof(*fourcc); i++) { 1785 unsigned char c = val >> (i * 8); 1786 1787 /* Print non-control ASCII characters as-is, dot otherwise */ 1788 *p++ = isascii(c) && isprint(c) ? c : '.'; 1789 } 1790 1791 strcpy(p, *fourcc & BIT(31) ? " big-endian" : " little-endian"); 1792 p += strlen(p); 1793 1794 *p++ = ' '; 1795 *p++ = '('; 1796 p = special_hex_number(p, output + sizeof(output) - 2, *fourcc, sizeof(u32)); 1797 *p++ = ')'; 1798 *p = '\0'; 1799 1800 return string(buf, end, output, spec); 1801 } 1802 1803 static noinline_for_stack 1804 char *address_val(char *buf, char *end, const void *addr, 1805 struct printf_spec spec, const char *fmt) 1806 { 1807 unsigned long long num; 1808 int size; 1809 1810 if (check_pointer(&buf, end, addr, spec)) 1811 return buf; 1812 1813 switch (fmt[1]) { 1814 case 'd': 1815 num = *(const dma_addr_t *)addr; 1816 size = sizeof(dma_addr_t); 1817 break; 1818 case 'p': 1819 default: 1820 num = *(const phys_addr_t *)addr; 1821 size = sizeof(phys_addr_t); 1822 break; 1823 } 1824 1825 return special_hex_number(buf, end, num, size); 1826 } 1827 1828 static noinline_for_stack 1829 char *date_str(char *buf, char *end, const struct rtc_time *tm, bool r) 1830 { 1831 int year = tm->tm_year + (r ? 0 : 1900); 1832 int mon = tm->tm_mon + (r ? 0 : 1); 1833 1834 buf = number(buf, end, year, default_dec04_spec); 1835 if (buf < end) 1836 *buf = '-'; 1837 buf++; 1838 1839 buf = number(buf, end, mon, default_dec02_spec); 1840 if (buf < end) 1841 *buf = '-'; 1842 buf++; 1843 1844 return number(buf, end, tm->tm_mday, default_dec02_spec); 1845 } 1846 1847 static noinline_for_stack 1848 char *time_str(char *buf, char *end, const struct rtc_time *tm, bool r) 1849 { 1850 buf = number(buf, end, tm->tm_hour, default_dec02_spec); 1851 if (buf < end) 1852 *buf = ':'; 1853 buf++; 1854 1855 buf = number(buf, end, tm->tm_min, default_dec02_spec); 1856 if (buf < end) 1857 *buf = ':'; 1858 buf++; 1859 1860 return number(buf, end, tm->tm_sec, default_dec02_spec); 1861 } 1862 1863 static noinline_for_stack 1864 char *rtc_str(char *buf, char *end, const struct rtc_time *tm, 1865 struct printf_spec spec, const char *fmt) 1866 { 1867 bool have_t = true, have_d = true; 1868 bool raw = false, iso8601_separator = true; 1869 bool found = true; 1870 int count = 2; 1871 1872 if (check_pointer(&buf, end, tm, spec)) 1873 return buf; 1874 1875 switch (fmt[count]) { 1876 case 'd': 1877 have_t = false; 1878 count++; 1879 break; 1880 case 't': 1881 have_d = false; 1882 count++; 1883 break; 1884 } 1885 1886 do { 1887 switch (fmt[count++]) { 1888 case 'r': 1889 raw = true; 1890 break; 1891 case 's': 1892 iso8601_separator = false; 1893 break; 1894 default: 1895 found = false; 1896 break; 1897 } 1898 } while (found); 1899 1900 if (have_d) 1901 buf = date_str(buf, end, tm, raw); 1902 if (have_d && have_t) { 1903 if (buf < end) 1904 *buf = iso8601_separator ? 'T' : ' '; 1905 buf++; 1906 } 1907 if (have_t) 1908 buf = time_str(buf, end, tm, raw); 1909 1910 return buf; 1911 } 1912 1913 static noinline_for_stack 1914 char *time64_str(char *buf, char *end, const time64_t time, 1915 struct printf_spec spec, const char *fmt) 1916 { 1917 struct rtc_time rtc_time; 1918 struct tm tm; 1919 1920 time64_to_tm(time, 0, &tm); 1921 1922 rtc_time.tm_sec = tm.tm_sec; 1923 rtc_time.tm_min = tm.tm_min; 1924 rtc_time.tm_hour = tm.tm_hour; 1925 rtc_time.tm_mday = tm.tm_mday; 1926 rtc_time.tm_mon = tm.tm_mon; 1927 rtc_time.tm_year = tm.tm_year; 1928 rtc_time.tm_wday = tm.tm_wday; 1929 rtc_time.tm_yday = tm.tm_yday; 1930 1931 rtc_time.tm_isdst = 0; 1932 1933 return rtc_str(buf, end, &rtc_time, spec, fmt); 1934 } 1935 1936 static noinline_for_stack 1937 char *time_and_date(char *buf, char *end, void *ptr, struct printf_spec spec, 1938 const char *fmt) 1939 { 1940 switch (fmt[1]) { 1941 case 'R': 1942 return rtc_str(buf, end, (const struct rtc_time *)ptr, spec, fmt); 1943 case 'T': 1944 return time64_str(buf, end, *(const time64_t *)ptr, spec, fmt); 1945 default: 1946 return error_string(buf, end, "(%pt?)", spec); 1947 } 1948 } 1949 1950 static noinline_for_stack 1951 char *clock(char *buf, char *end, struct clk *clk, struct printf_spec spec, 1952 const char *fmt) 1953 { 1954 if (!IS_ENABLED(CONFIG_HAVE_CLK)) 1955 return error_string(buf, end, "(%pC?)", spec); 1956 1957 if (check_pointer(&buf, end, clk, spec)) 1958 return buf; 1959 1960 switch (fmt[1]) { 1961 case 'n': 1962 default: 1963 #ifdef CONFIG_COMMON_CLK 1964 return string(buf, end, __clk_get_name(clk), spec); 1965 #else 1966 return ptr_to_id(buf, end, clk, spec); 1967 #endif 1968 } 1969 } 1970 1971 static 1972 char *format_flags(char *buf, char *end, unsigned long flags, 1973 const struct trace_print_flags *names) 1974 { 1975 unsigned long mask; 1976 1977 for ( ; flags && names->name; names++) { 1978 mask = names->mask; 1979 if ((flags & mask) != mask) 1980 continue; 1981 1982 buf = string(buf, end, names->name, default_str_spec); 1983 1984 flags &= ~mask; 1985 if (flags) { 1986 if (buf < end) 1987 *buf = '|'; 1988 buf++; 1989 } 1990 } 1991 1992 if (flags) 1993 buf = number(buf, end, flags, default_flag_spec); 1994 1995 return buf; 1996 } 1997 1998 struct page_flags_fields { 1999 int width; 2000 int shift; 2001 int mask; 2002 const struct printf_spec *spec; 2003 const char *name; 2004 }; 2005 2006 static const struct page_flags_fields pff[] = { 2007 {SECTIONS_WIDTH, SECTIONS_PGSHIFT, SECTIONS_MASK, 2008 &default_dec_spec, "section"}, 2009 {NODES_WIDTH, NODES_PGSHIFT, NODES_MASK, 2010 &default_dec_spec, "node"}, 2011 {ZONES_WIDTH, ZONES_PGSHIFT, ZONES_MASK, 2012 &default_dec_spec, "zone"}, 2013 {LAST_CPUPID_WIDTH, LAST_CPUPID_PGSHIFT, LAST_CPUPID_MASK, 2014 &default_flag_spec, "lastcpupid"}, 2015 {KASAN_TAG_WIDTH, KASAN_TAG_PGSHIFT, KASAN_TAG_MASK, 2016 &default_flag_spec, "kasantag"}, 2017 }; 2018 2019 static 2020 char *format_page_flags(char *buf, char *end, unsigned long flags) 2021 { 2022 unsigned long main_flags = flags & PAGEFLAGS_MASK; 2023 bool append = false; 2024 int i; 2025 2026 /* Page flags from the main area. */ 2027 if (main_flags) { 2028 buf = format_flags(buf, end, main_flags, pageflag_names); 2029 append = true; 2030 } 2031 2032 /* Page flags from the fields area */ 2033 for (i = 0; i < ARRAY_SIZE(pff); i++) { 2034 /* Skip undefined fields. */ 2035 if (!pff[i].width) 2036 continue; 2037 2038 /* Format: Flag Name + '=' (equals sign) + Number + '|' (separator) */ 2039 if (append) { 2040 if (buf < end) 2041 *buf = '|'; 2042 buf++; 2043 } 2044 2045 buf = string(buf, end, pff[i].name, default_str_spec); 2046 if (buf < end) 2047 *buf = '='; 2048 buf++; 2049 buf = number(buf, end, (flags >> pff[i].shift) & pff[i].mask, 2050 *pff[i].spec); 2051 2052 append = true; 2053 } 2054 2055 return buf; 2056 } 2057 2058 static noinline_for_stack 2059 char *flags_string(char *buf, char *end, void *flags_ptr, 2060 struct printf_spec spec, const char *fmt) 2061 { 2062 unsigned long flags; 2063 const struct trace_print_flags *names; 2064 2065 if (check_pointer(&buf, end, flags_ptr, spec)) 2066 return buf; 2067 2068 switch (fmt[1]) { 2069 case 'p': 2070 return format_page_flags(buf, end, *(unsigned long *)flags_ptr); 2071 case 'v': 2072 flags = *(unsigned long *)flags_ptr; 2073 names = vmaflag_names; 2074 break; 2075 case 'g': 2076 flags = (__force unsigned long)(*(gfp_t *)flags_ptr); 2077 names = gfpflag_names; 2078 break; 2079 default: 2080 return error_string(buf, end, "(%pG?)", spec); 2081 } 2082 2083 return format_flags(buf, end, flags, names); 2084 } 2085 2086 static noinline_for_stack 2087 char *fwnode_full_name_string(struct fwnode_handle *fwnode, char *buf, 2088 char *end) 2089 { 2090 int depth; 2091 2092 /* Loop starting from the root node to the current node. */ 2093 for (depth = fwnode_count_parents(fwnode); depth >= 0; depth--) { 2094 struct fwnode_handle *__fwnode = 2095 fwnode_get_nth_parent(fwnode, depth); 2096 2097 buf = string(buf, end, fwnode_get_name_prefix(__fwnode), 2098 default_str_spec); 2099 buf = string(buf, end, fwnode_get_name(__fwnode), 2100 default_str_spec); 2101 2102 fwnode_handle_put(__fwnode); 2103 } 2104 2105 return buf; 2106 } 2107 2108 static noinline_for_stack 2109 char *device_node_string(char *buf, char *end, struct device_node *dn, 2110 struct printf_spec spec, const char *fmt) 2111 { 2112 char tbuf[sizeof("xxxx") + 1]; 2113 const char *p; 2114 int ret; 2115 char *buf_start = buf; 2116 struct property *prop; 2117 bool has_mult, pass; 2118 2119 struct printf_spec str_spec = spec; 2120 str_spec.field_width = -1; 2121 2122 if (fmt[0] != 'F') 2123 return error_string(buf, end, "(%pO?)", spec); 2124 2125 if (!IS_ENABLED(CONFIG_OF)) 2126 return error_string(buf, end, "(%pOF?)", spec); 2127 2128 if (check_pointer(&buf, end, dn, spec)) 2129 return buf; 2130 2131 /* simple case without anything any more format specifiers */ 2132 fmt++; 2133 if (fmt[0] == '\0' || strcspn(fmt,"fnpPFcC") > 0) 2134 fmt = "f"; 2135 2136 for (pass = false; strspn(fmt,"fnpPFcC"); fmt++, pass = true) { 2137 int precision; 2138 if (pass) { 2139 if (buf < end) 2140 *buf = ':'; 2141 buf++; 2142 } 2143 2144 switch (*fmt) { 2145 case 'f': /* full_name */ 2146 buf = fwnode_full_name_string(of_fwnode_handle(dn), buf, 2147 end); 2148 break; 2149 case 'n': /* name */ 2150 p = fwnode_get_name(of_fwnode_handle(dn)); 2151 precision = str_spec.precision; 2152 str_spec.precision = strchrnul(p, '@') - p; 2153 buf = string(buf, end, p, str_spec); 2154 str_spec.precision = precision; 2155 break; 2156 case 'p': /* phandle */ 2157 buf = number(buf, end, (unsigned int)dn->phandle, default_dec_spec); 2158 break; 2159 case 'P': /* path-spec */ 2160 p = fwnode_get_name(of_fwnode_handle(dn)); 2161 if (!p[1]) 2162 p = "/"; 2163 buf = string(buf, end, p, str_spec); 2164 break; 2165 case 'F': /* flags */ 2166 tbuf[0] = of_node_check_flag(dn, OF_DYNAMIC) ? 'D' : '-'; 2167 tbuf[1] = of_node_check_flag(dn, OF_DETACHED) ? 'd' : '-'; 2168 tbuf[2] = of_node_check_flag(dn, OF_POPULATED) ? 'P' : '-'; 2169 tbuf[3] = of_node_check_flag(dn, OF_POPULATED_BUS) ? 'B' : '-'; 2170 tbuf[4] = 0; 2171 buf = string_nocheck(buf, end, tbuf, str_spec); 2172 break; 2173 case 'c': /* major compatible string */ 2174 ret = of_property_read_string(dn, "compatible", &p); 2175 if (!ret) 2176 buf = string(buf, end, p, str_spec); 2177 break; 2178 case 'C': /* full compatible string */ 2179 has_mult = false; 2180 of_property_for_each_string(dn, "compatible", prop, p) { 2181 if (has_mult) 2182 buf = string_nocheck(buf, end, ",", str_spec); 2183 buf = string_nocheck(buf, end, "\"", str_spec); 2184 buf = string(buf, end, p, str_spec); 2185 buf = string_nocheck(buf, end, "\"", str_spec); 2186 2187 has_mult = true; 2188 } 2189 break; 2190 default: 2191 break; 2192 } 2193 } 2194 2195 return widen_string(buf, buf - buf_start, end, spec); 2196 } 2197 2198 static noinline_for_stack 2199 char *fwnode_string(char *buf, char *end, struct fwnode_handle *fwnode, 2200 struct printf_spec spec, const char *fmt) 2201 { 2202 struct printf_spec str_spec = spec; 2203 char *buf_start = buf; 2204 2205 str_spec.field_width = -1; 2206 2207 if (*fmt != 'w') 2208 return error_string(buf, end, "(%pf?)", spec); 2209 2210 if (check_pointer(&buf, end, fwnode, spec)) 2211 return buf; 2212 2213 fmt++; 2214 2215 switch (*fmt) { 2216 case 'P': /* name */ 2217 buf = string(buf, end, fwnode_get_name(fwnode), str_spec); 2218 break; 2219 case 'f': /* full_name */ 2220 default: 2221 buf = fwnode_full_name_string(fwnode, buf, end); 2222 break; 2223 } 2224 2225 return widen_string(buf, buf - buf_start, end, spec); 2226 } 2227 2228 /* Disable pointer hashing if requested */ 2229 bool no_hash_pointers __ro_after_init; 2230 EXPORT_SYMBOL_GPL(no_hash_pointers); 2231 2232 int __init no_hash_pointers_enable(char *str) 2233 { 2234 if (no_hash_pointers) 2235 return 0; 2236 2237 no_hash_pointers = true; 2238 2239 pr_warn("**********************************************************\n"); 2240 pr_warn("** NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE **\n"); 2241 pr_warn("** **\n"); 2242 pr_warn("** This system shows unhashed kernel memory addresses **\n"); 2243 pr_warn("** via the console, logs, and other interfaces. This **\n"); 2244 pr_warn("** might reduce the security of your system. **\n"); 2245 pr_warn("** **\n"); 2246 pr_warn("** If you see this message and you are not debugging **\n"); 2247 pr_warn("** the kernel, report this immediately to your system **\n"); 2248 pr_warn("** administrator! **\n"); 2249 pr_warn("** **\n"); 2250 pr_warn("** NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE **\n"); 2251 pr_warn("**********************************************************\n"); 2252 2253 return 0; 2254 } 2255 early_param("no_hash_pointers", no_hash_pointers_enable); 2256 2257 /* 2258 * Show a '%p' thing. A kernel extension is that the '%p' is followed 2259 * by an extra set of alphanumeric characters that are extended format 2260 * specifiers. 2261 * 2262 * Please update scripts/checkpatch.pl when adding/removing conversion 2263 * characters. (Search for "check for vsprintf extension"). 2264 * 2265 * Right now we handle: 2266 * 2267 * - 'S' For symbolic direct pointers (or function descriptors) with offset 2268 * - 's' For symbolic direct pointers (or function descriptors) without offset 2269 * - '[Ss]R' as above with __builtin_extract_return_addr() translation 2270 * - 'S[R]b' as above with module build ID (for use in backtraces) 2271 * - '[Ff]' %pf and %pF were obsoleted and later removed in favor of 2272 * %ps and %pS. Be careful when re-using these specifiers. 2273 * - 'B' For backtraced symbolic direct pointers with offset 2274 * - 'Bb' as above with module build ID (for use in backtraces) 2275 * - 'R' For decoded struct resource, e.g., [mem 0x0-0x1f 64bit pref] 2276 * - 'r' For raw struct resource, e.g., [mem 0x0-0x1f flags 0x201] 2277 * - 'b[l]' For a bitmap, the number of bits is determined by the field 2278 * width which must be explicitly specified either as part of the 2279 * format string '%32b[l]' or through '%*b[l]', [l] selects 2280 * range-list format instead of hex format 2281 * - 'M' For a 6-byte MAC address, it prints the address in the 2282 * usual colon-separated hex notation 2283 * - 'm' For a 6-byte MAC address, it prints the hex address without colons 2284 * - 'MF' For a 6-byte MAC FDDI address, it prints the address 2285 * with a dash-separated hex notation 2286 * - '[mM]R' For a 6-byte MAC address, Reverse order (Bluetooth) 2287 * - 'I' [46] for IPv4/IPv6 addresses printed in the usual way 2288 * IPv4 uses dot-separated decimal without leading 0's (1.2.3.4) 2289 * IPv6 uses colon separated network-order 16 bit hex with leading 0's 2290 * [S][pfs] 2291 * Generic IPv4/IPv6 address (struct sockaddr *) that falls back to 2292 * [4] or [6] and is able to print port [p], flowinfo [f], scope [s] 2293 * - 'i' [46] for 'raw' IPv4/IPv6 addresses 2294 * IPv6 omits the colons (01020304...0f) 2295 * IPv4 uses dot-separated decimal with leading 0's (010.123.045.006) 2296 * [S][pfs] 2297 * Generic IPv4/IPv6 address (struct sockaddr *) that falls back to 2298 * [4] or [6] and is able to print port [p], flowinfo [f], scope [s] 2299 * - '[Ii][4S][hnbl]' IPv4 addresses in host, network, big or little endian order 2300 * - 'I[6S]c' for IPv6 addresses printed as specified by 2301 * https://tools.ietf.org/html/rfc5952 2302 * - 'E[achnops]' For an escaped buffer, where rules are defined by combination 2303 * of the following flags (see string_escape_mem() for the 2304 * details): 2305 * a - ESCAPE_ANY 2306 * c - ESCAPE_SPECIAL 2307 * h - ESCAPE_HEX 2308 * n - ESCAPE_NULL 2309 * o - ESCAPE_OCTAL 2310 * p - ESCAPE_NP 2311 * s - ESCAPE_SPACE 2312 * By default ESCAPE_ANY_NP is used. 2313 * - 'U' For a 16 byte UUID/GUID, it prints the UUID/GUID in the form 2314 * "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx" 2315 * Options for %pU are: 2316 * b big endian lower case hex (default) 2317 * B big endian UPPER case hex 2318 * l little endian lower case hex 2319 * L little endian UPPER case hex 2320 * big endian output byte order is: 2321 * [0][1][2][3]-[4][5]-[6][7]-[8][9]-[10][11][12][13][14][15] 2322 * little endian output byte order is: 2323 * [3][2][1][0]-[5][4]-[7][6]-[8][9]-[10][11][12][13][14][15] 2324 * - 'V' For a struct va_format which contains a format string * and va_list *, 2325 * call vsnprintf(->format, *->va_list). 2326 * Implements a "recursive vsnprintf". 2327 * Do not use this feature without some mechanism to verify the 2328 * correctness of the format string and va_list arguments. 2329 * - 'K' For a kernel pointer that should be hidden from unprivileged users. 2330 * Use only for procfs, sysfs and similar files, not printk(); please 2331 * read the documentation (path below) first. 2332 * - 'NF' For a netdev_features_t 2333 * - '4cc' V4L2 or DRM FourCC code, with endianness and raw numerical value. 2334 * - 'h[CDN]' For a variable-length buffer, it prints it as a hex string with 2335 * a certain separator (' ' by default): 2336 * C colon 2337 * D dash 2338 * N no separator 2339 * The maximum supported length is 64 bytes of the input. Consider 2340 * to use print_hex_dump() for the larger input. 2341 * - 'a[pd]' For address types [p] phys_addr_t, [d] dma_addr_t and derivatives 2342 * (default assumed to be phys_addr_t, passed by reference) 2343 * - 'd[234]' For a dentry name (optionally 2-4 last components) 2344 * - 'D[234]' Same as 'd' but for a struct file 2345 * - 'g' For block_device name (gendisk + partition number) 2346 * - 't[RT][dt][r][s]' For time and date as represented by: 2347 * R struct rtc_time 2348 * T time64_t 2349 * - 'C' For a clock, it prints the name (Common Clock Framework) or address 2350 * (legacy clock framework) of the clock 2351 * - 'Cn' For a clock, it prints the name (Common Clock Framework) or address 2352 * (legacy clock framework) of the clock 2353 * - 'G' For flags to be printed as a collection of symbolic strings that would 2354 * construct the specific value. Supported flags given by option: 2355 * p page flags (see struct page) given as pointer to unsigned long 2356 * g gfp flags (GFP_* and __GFP_*) given as pointer to gfp_t 2357 * v vma flags (VM_*) given as pointer to unsigned long 2358 * - 'OF[fnpPcCF]' For a device tree object 2359 * Without any optional arguments prints the full_name 2360 * f device node full_name 2361 * n device node name 2362 * p device node phandle 2363 * P device node path spec (name + @unit) 2364 * F device node flags 2365 * c major compatible string 2366 * C full compatible string 2367 * - 'fw[fP]' For a firmware node (struct fwnode_handle) pointer 2368 * Without an option prints the full name of the node 2369 * f full name 2370 * P node name, including a possible unit address 2371 * - 'x' For printing the address unmodified. Equivalent to "%lx". 2372 * Please read the documentation (path below) before using! 2373 * - '[ku]s' For a BPF/tracing related format specifier, e.g. used out of 2374 * bpf_trace_printk() where [ku] prefix specifies either kernel (k) 2375 * or user (u) memory to probe, and: 2376 * s a string, equivalent to "%s" on direct vsnprintf() use 2377 * 2378 * ** When making changes please also update: 2379 * Documentation/core-api/printk-formats.rst 2380 * 2381 * Note: The default behaviour (unadorned %p) is to hash the address, 2382 * rendering it useful as a unique identifier. 2383 */ 2384 static noinline_for_stack 2385 char *pointer(const char *fmt, char *buf, char *end, void *ptr, 2386 struct printf_spec spec) 2387 { 2388 switch (*fmt) { 2389 case 'S': 2390 case 's': 2391 ptr = dereference_symbol_descriptor(ptr); 2392 fallthrough; 2393 case 'B': 2394 return symbol_string(buf, end, ptr, spec, fmt); 2395 case 'R': 2396 case 'r': 2397 return resource_string(buf, end, ptr, spec, fmt); 2398 case 'h': 2399 return hex_string(buf, end, ptr, spec, fmt); 2400 case 'b': 2401 switch (fmt[1]) { 2402 case 'l': 2403 return bitmap_list_string(buf, end, ptr, spec, fmt); 2404 default: 2405 return bitmap_string(buf, end, ptr, spec, fmt); 2406 } 2407 case 'M': /* Colon separated: 00:01:02:03:04:05 */ 2408 case 'm': /* Contiguous: 000102030405 */ 2409 /* [mM]F (FDDI) */ 2410 /* [mM]R (Reverse order; Bluetooth) */ 2411 return mac_address_string(buf, end, ptr, spec, fmt); 2412 case 'I': /* Formatted IP supported 2413 * 4: 1.2.3.4 2414 * 6: 0001:0203:...:0708 2415 * 6c: 1::708 or 1::1.2.3.4 2416 */ 2417 case 'i': /* Contiguous: 2418 * 4: 001.002.003.004 2419 * 6: 000102...0f 2420 */ 2421 return ip_addr_string(buf, end, ptr, spec, fmt); 2422 case 'E': 2423 return escaped_string(buf, end, ptr, spec, fmt); 2424 case 'U': 2425 return uuid_string(buf, end, ptr, spec, fmt); 2426 case 'V': 2427 return va_format(buf, end, ptr, spec, fmt); 2428 case 'K': 2429 return restricted_pointer(buf, end, ptr, spec); 2430 case 'N': 2431 return netdev_bits(buf, end, ptr, spec, fmt); 2432 case '4': 2433 return fourcc_string(buf, end, ptr, spec, fmt); 2434 case 'a': 2435 return address_val(buf, end, ptr, spec, fmt); 2436 case 'd': 2437 return dentry_name(buf, end, ptr, spec, fmt); 2438 case 't': 2439 return time_and_date(buf, end, ptr, spec, fmt); 2440 case 'C': 2441 return clock(buf, end, ptr, spec, fmt); 2442 case 'D': 2443 return file_dentry_name(buf, end, ptr, spec, fmt); 2444 #ifdef CONFIG_BLOCK 2445 case 'g': 2446 return bdev_name(buf, end, ptr, spec, fmt); 2447 #endif 2448 2449 case 'G': 2450 return flags_string(buf, end, ptr, spec, fmt); 2451 case 'O': 2452 return device_node_string(buf, end, ptr, spec, fmt + 1); 2453 case 'f': 2454 return fwnode_string(buf, end, ptr, spec, fmt + 1); 2455 case 'x': 2456 return pointer_string(buf, end, ptr, spec); 2457 case 'e': 2458 /* %pe with a non-ERR_PTR gets treated as plain %p */ 2459 if (!IS_ERR(ptr)) 2460 break; 2461 return err_ptr(buf, end, ptr, spec); 2462 case 'u': 2463 case 'k': 2464 switch (fmt[1]) { 2465 case 's': 2466 return string(buf, end, ptr, spec); 2467 default: 2468 return error_string(buf, end, "(einval)", spec); 2469 } 2470 } 2471 2472 /* 2473 * default is to _not_ leak addresses, so hash before printing, 2474 * unless no_hash_pointers is specified on the command line. 2475 */ 2476 if (unlikely(no_hash_pointers)) 2477 return pointer_string(buf, end, ptr, spec); 2478 else 2479 return ptr_to_id(buf, end, ptr, spec); 2480 } 2481 2482 /* 2483 * Helper function to decode printf style format. 2484 * Each call decode a token from the format and return the 2485 * number of characters read (or likely the delta where it wants 2486 * to go on the next call). 2487 * The decoded token is returned through the parameters 2488 * 2489 * 'h', 'l', or 'L' for integer fields 2490 * 'z' support added 23/7/1999 S.H. 2491 * 'z' changed to 'Z' --davidm 1/25/99 2492 * 'Z' changed to 'z' --adobriyan 2017-01-25 2493 * 't' added for ptrdiff_t 2494 * 2495 * @fmt: the format string 2496 * @type of the token returned 2497 * @flags: various flags such as +, -, # tokens.. 2498 * @field_width: overwritten width 2499 * @base: base of the number (octal, hex, ...) 2500 * @precision: precision of a number 2501 * @qualifier: qualifier of a number (long, size_t, ...) 2502 */ 2503 static noinline_for_stack 2504 int format_decode(const char *fmt, struct printf_spec *spec) 2505 { 2506 const char *start = fmt; 2507 char qualifier; 2508 2509 /* we finished early by reading the field width */ 2510 if (spec->type == FORMAT_TYPE_WIDTH) { 2511 if (spec->field_width < 0) { 2512 spec->field_width = -spec->field_width; 2513 spec->flags |= LEFT; 2514 } 2515 spec->type = FORMAT_TYPE_NONE; 2516 goto precision; 2517 } 2518 2519 /* we finished early by reading the precision */ 2520 if (spec->type == FORMAT_TYPE_PRECISION) { 2521 if (spec->precision < 0) 2522 spec->precision = 0; 2523 2524 spec->type = FORMAT_TYPE_NONE; 2525 goto qualifier; 2526 } 2527 2528 /* By default */ 2529 spec->type = FORMAT_TYPE_NONE; 2530 2531 for (; *fmt ; ++fmt) { 2532 if (*fmt == '%') 2533 break; 2534 } 2535 2536 /* Return the current non-format string */ 2537 if (fmt != start || !*fmt) 2538 return fmt - start; 2539 2540 /* Process flags */ 2541 spec->flags = 0; 2542 2543 while (1) { /* this also skips first '%' */ 2544 bool found = true; 2545 2546 ++fmt; 2547 2548 switch (*fmt) { 2549 case '-': spec->flags |= LEFT; break; 2550 case '+': spec->flags |= PLUS; break; 2551 case ' ': spec->flags |= SPACE; break; 2552 case '#': spec->flags |= SPECIAL; break; 2553 case '0': spec->flags |= ZEROPAD; break; 2554 default: found = false; 2555 } 2556 2557 if (!found) 2558 break; 2559 } 2560 2561 /* get field width */ 2562 spec->field_width = -1; 2563 2564 if (isdigit(*fmt)) 2565 spec->field_width = skip_atoi(&fmt); 2566 else if (*fmt == '*') { 2567 /* it's the next argument */ 2568 spec->type = FORMAT_TYPE_WIDTH; 2569 return ++fmt - start; 2570 } 2571 2572 precision: 2573 /* get the precision */ 2574 spec->precision = -1; 2575 if (*fmt == '.') { 2576 ++fmt; 2577 if (isdigit(*fmt)) { 2578 spec->precision = skip_atoi(&fmt); 2579 if (spec->precision < 0) 2580 spec->precision = 0; 2581 } else if (*fmt == '*') { 2582 /* it's the next argument */ 2583 spec->type = FORMAT_TYPE_PRECISION; 2584 return ++fmt - start; 2585 } 2586 } 2587 2588 qualifier: 2589 /* get the conversion qualifier */ 2590 qualifier = 0; 2591 if (*fmt == 'h' || _tolower(*fmt) == 'l' || 2592 *fmt == 'z' || *fmt == 't') { 2593 qualifier = *fmt++; 2594 if (unlikely(qualifier == *fmt)) { 2595 if (qualifier == 'l') { 2596 qualifier = 'L'; 2597 ++fmt; 2598 } else if (qualifier == 'h') { 2599 qualifier = 'H'; 2600 ++fmt; 2601 } 2602 } 2603 } 2604 2605 /* default base */ 2606 spec->base = 10; 2607 switch (*fmt) { 2608 case 'c': 2609 spec->type = FORMAT_TYPE_CHAR; 2610 return ++fmt - start; 2611 2612 case 's': 2613 spec->type = FORMAT_TYPE_STR; 2614 return ++fmt - start; 2615 2616 case 'p': 2617 spec->type = FORMAT_TYPE_PTR; 2618 return ++fmt - start; 2619 2620 case '%': 2621 spec->type = FORMAT_TYPE_PERCENT_CHAR; 2622 return ++fmt - start; 2623 2624 /* integer number formats - set up the flags and "break" */ 2625 case 'o': 2626 spec->base = 8; 2627 break; 2628 2629 case 'x': 2630 spec->flags |= SMALL; 2631 fallthrough; 2632 2633 case 'X': 2634 spec->base = 16; 2635 break; 2636 2637 case 'd': 2638 case 'i': 2639 spec->flags |= SIGN; 2640 break; 2641 case 'u': 2642 break; 2643 2644 case 'n': 2645 /* 2646 * Since %n poses a greater security risk than 2647 * utility, treat it as any other invalid or 2648 * unsupported format specifier. 2649 */ 2650 fallthrough; 2651 2652 default: 2653 WARN_ONCE(1, "Please remove unsupported %%%c in format string\n", *fmt); 2654 spec->type = FORMAT_TYPE_INVALID; 2655 return fmt - start; 2656 } 2657 2658 if (qualifier == 'L') 2659 spec->type = FORMAT_TYPE_LONG_LONG; 2660 else if (qualifier == 'l') { 2661 BUILD_BUG_ON(FORMAT_TYPE_ULONG + SIGN != FORMAT_TYPE_LONG); 2662 spec->type = FORMAT_TYPE_ULONG + (spec->flags & SIGN); 2663 } else if (qualifier == 'z') { 2664 spec->type = FORMAT_TYPE_SIZE_T; 2665 } else if (qualifier == 't') { 2666 spec->type = FORMAT_TYPE_PTRDIFF; 2667 } else if (qualifier == 'H') { 2668 BUILD_BUG_ON(FORMAT_TYPE_UBYTE + SIGN != FORMAT_TYPE_BYTE); 2669 spec->type = FORMAT_TYPE_UBYTE + (spec->flags & SIGN); 2670 } else if (qualifier == 'h') { 2671 BUILD_BUG_ON(FORMAT_TYPE_USHORT + SIGN != FORMAT_TYPE_SHORT); 2672 spec->type = FORMAT_TYPE_USHORT + (spec->flags & SIGN); 2673 } else { 2674 BUILD_BUG_ON(FORMAT_TYPE_UINT + SIGN != FORMAT_TYPE_INT); 2675 spec->type = FORMAT_TYPE_UINT + (spec->flags & SIGN); 2676 } 2677 2678 return ++fmt - start; 2679 } 2680 2681 static void 2682 set_field_width(struct printf_spec *spec, int width) 2683 { 2684 spec->field_width = width; 2685 if (WARN_ONCE(spec->field_width != width, "field width %d too large", width)) { 2686 spec->field_width = clamp(width, -FIELD_WIDTH_MAX, FIELD_WIDTH_MAX); 2687 } 2688 } 2689 2690 static void 2691 set_precision(struct printf_spec *spec, int prec) 2692 { 2693 spec->precision = prec; 2694 if (WARN_ONCE(spec->precision != prec, "precision %d too large", prec)) { 2695 spec->precision = clamp(prec, 0, PRECISION_MAX); 2696 } 2697 } 2698 2699 /** 2700 * vsnprintf - Format a string and place it in a buffer 2701 * @buf: The buffer to place the result into 2702 * @size: The size of the buffer, including the trailing null space 2703 * @fmt: The format string to use 2704 * @args: Arguments for the format string 2705 * 2706 * This function generally follows C99 vsnprintf, but has some 2707 * extensions and a few limitations: 2708 * 2709 * - ``%n`` is unsupported 2710 * - ``%p*`` is handled by pointer() 2711 * 2712 * See pointer() or Documentation/core-api/printk-formats.rst for more 2713 * extensive description. 2714 * 2715 * **Please update the documentation in both places when making changes** 2716 * 2717 * The return value is the number of characters which would 2718 * be generated for the given input, excluding the trailing 2719 * '\0', as per ISO C99. If you want to have the exact 2720 * number of characters written into @buf as return value 2721 * (not including the trailing '\0'), use vscnprintf(). If the 2722 * return is greater than or equal to @size, the resulting 2723 * string is truncated. 2724 * 2725 * If you're not already dealing with a va_list consider using snprintf(). 2726 */ 2727 int vsnprintf(char *buf, size_t size, const char *fmt, va_list args) 2728 { 2729 unsigned long long num; 2730 char *str, *end; 2731 struct printf_spec spec = {0}; 2732 2733 /* Reject out-of-range values early. Large positive sizes are 2734 used for unknown buffer sizes. */ 2735 if (WARN_ON_ONCE(size > INT_MAX)) 2736 return 0; 2737 2738 str = buf; 2739 end = buf + size; 2740 2741 /* Make sure end is always >= buf */ 2742 if (end < buf) { 2743 end = ((void *)-1); 2744 size = end - buf; 2745 } 2746 2747 while (*fmt) { 2748 const char *old_fmt = fmt; 2749 int read = format_decode(fmt, &spec); 2750 2751 fmt += read; 2752 2753 switch (spec.type) { 2754 case FORMAT_TYPE_NONE: { 2755 int copy = read; 2756 if (str < end) { 2757 if (copy > end - str) 2758 copy = end - str; 2759 memcpy(str, old_fmt, copy); 2760 } 2761 str += read; 2762 break; 2763 } 2764 2765 case FORMAT_TYPE_WIDTH: 2766 set_field_width(&spec, va_arg(args, int)); 2767 break; 2768 2769 case FORMAT_TYPE_PRECISION: 2770 set_precision(&spec, va_arg(args, int)); 2771 break; 2772 2773 case FORMAT_TYPE_CHAR: { 2774 char c; 2775 2776 if (!(spec.flags & LEFT)) { 2777 while (--spec.field_width > 0) { 2778 if (str < end) 2779 *str = ' '; 2780 ++str; 2781 2782 } 2783 } 2784 c = (unsigned char) va_arg(args, int); 2785 if (str < end) 2786 *str = c; 2787 ++str; 2788 while (--spec.field_width > 0) { 2789 if (str < end) 2790 *str = ' '; 2791 ++str; 2792 } 2793 break; 2794 } 2795 2796 case FORMAT_TYPE_STR: 2797 str = string(str, end, va_arg(args, char *), spec); 2798 break; 2799 2800 case FORMAT_TYPE_PTR: 2801 str = pointer(fmt, str, end, va_arg(args, void *), 2802 spec); 2803 while (isalnum(*fmt)) 2804 fmt++; 2805 break; 2806 2807 case FORMAT_TYPE_PERCENT_CHAR: 2808 if (str < end) 2809 *str = '%'; 2810 ++str; 2811 break; 2812 2813 case FORMAT_TYPE_INVALID: 2814 /* 2815 * Presumably the arguments passed gcc's type 2816 * checking, but there is no safe or sane way 2817 * for us to continue parsing the format and 2818 * fetching from the va_list; the remaining 2819 * specifiers and arguments would be out of 2820 * sync. 2821 */ 2822 goto out; 2823 2824 default: 2825 switch (spec.type) { 2826 case FORMAT_TYPE_LONG_LONG: 2827 num = va_arg(args, long long); 2828 break; 2829 case FORMAT_TYPE_ULONG: 2830 num = va_arg(args, unsigned long); 2831 break; 2832 case FORMAT_TYPE_LONG: 2833 num = va_arg(args, long); 2834 break; 2835 case FORMAT_TYPE_SIZE_T: 2836 if (spec.flags & SIGN) 2837 num = va_arg(args, ssize_t); 2838 else 2839 num = va_arg(args, size_t); 2840 break; 2841 case FORMAT_TYPE_PTRDIFF: 2842 num = va_arg(args, ptrdiff_t); 2843 break; 2844 case FORMAT_TYPE_UBYTE: 2845 num = (unsigned char) va_arg(args, int); 2846 break; 2847 case FORMAT_TYPE_BYTE: 2848 num = (signed char) va_arg(args, int); 2849 break; 2850 case FORMAT_TYPE_USHORT: 2851 num = (unsigned short) va_arg(args, int); 2852 break; 2853 case FORMAT_TYPE_SHORT: 2854 num = (short) va_arg(args, int); 2855 break; 2856 case FORMAT_TYPE_INT: 2857 num = (int) va_arg(args, int); 2858 break; 2859 default: 2860 num = va_arg(args, unsigned int); 2861 } 2862 2863 str = number(str, end, num, spec); 2864 } 2865 } 2866 2867 out: 2868 if (size > 0) { 2869 if (str < end) 2870 *str = '\0'; 2871 else 2872 end[-1] = '\0'; 2873 } 2874 2875 /* the trailing null byte doesn't count towards the total */ 2876 return str-buf; 2877 2878 } 2879 EXPORT_SYMBOL(vsnprintf); 2880 2881 /** 2882 * vscnprintf - Format a string and place it in a buffer 2883 * @buf: The buffer to place the result into 2884 * @size: The size of the buffer, including the trailing null space 2885 * @fmt: The format string to use 2886 * @args: Arguments for the format string 2887 * 2888 * The return value is the number of characters which have been written into 2889 * the @buf not including the trailing '\0'. If @size is == 0 the function 2890 * returns 0. 2891 * 2892 * If you're not already dealing with a va_list consider using scnprintf(). 2893 * 2894 * See the vsnprintf() documentation for format string extensions over C99. 2895 */ 2896 int vscnprintf(char *buf, size_t size, const char *fmt, va_list args) 2897 { 2898 int i; 2899 2900 i = vsnprintf(buf, size, fmt, args); 2901 2902 if (likely(i < size)) 2903 return i; 2904 if (size != 0) 2905 return size - 1; 2906 return 0; 2907 } 2908 EXPORT_SYMBOL(vscnprintf); 2909 2910 /** 2911 * snprintf - Format a string and place it in a buffer 2912 * @buf: The buffer to place the result into 2913 * @size: The size of the buffer, including the trailing null space 2914 * @fmt: The format string to use 2915 * @...: Arguments for the format string 2916 * 2917 * The return value is the number of characters which would be 2918 * generated for the given input, excluding the trailing null, 2919 * as per ISO C99. If the return is greater than or equal to 2920 * @size, the resulting string is truncated. 2921 * 2922 * See the vsnprintf() documentation for format string extensions over C99. 2923 */ 2924 int snprintf(char *buf, size_t size, const char *fmt, ...) 2925 { 2926 va_list args; 2927 int i; 2928 2929 va_start(args, fmt); 2930 i = vsnprintf(buf, size, fmt, args); 2931 va_end(args); 2932 2933 return i; 2934 } 2935 EXPORT_SYMBOL(snprintf); 2936 2937 /** 2938 * scnprintf - Format a string and place it in a buffer 2939 * @buf: The buffer to place the result into 2940 * @size: The size of the buffer, including the trailing null space 2941 * @fmt: The format string to use 2942 * @...: Arguments for the format string 2943 * 2944 * The return value is the number of characters written into @buf not including 2945 * the trailing '\0'. If @size is == 0 the function returns 0. 2946 */ 2947 2948 int scnprintf(char *buf, size_t size, const char *fmt, ...) 2949 { 2950 va_list args; 2951 int i; 2952 2953 va_start(args, fmt); 2954 i = vscnprintf(buf, size, fmt, args); 2955 va_end(args); 2956 2957 return i; 2958 } 2959 EXPORT_SYMBOL(scnprintf); 2960 2961 /** 2962 * vsprintf - Format a string and place it in a buffer 2963 * @buf: The buffer to place the result into 2964 * @fmt: The format string to use 2965 * @args: Arguments for the format string 2966 * 2967 * The function returns the number of characters written 2968 * into @buf. Use vsnprintf() or vscnprintf() in order to avoid 2969 * buffer overflows. 2970 * 2971 * If you're not already dealing with a va_list consider using sprintf(). 2972 * 2973 * See the vsnprintf() documentation for format string extensions over C99. 2974 */ 2975 int vsprintf(char *buf, const char *fmt, va_list args) 2976 { 2977 return vsnprintf(buf, INT_MAX, fmt, args); 2978 } 2979 EXPORT_SYMBOL(vsprintf); 2980 2981 /** 2982 * sprintf - Format a string and place it in a buffer 2983 * @buf: The buffer to place the result into 2984 * @fmt: The format string to use 2985 * @...: Arguments for the format string 2986 * 2987 * The function returns the number of characters written 2988 * into @buf. Use snprintf() or scnprintf() in order to avoid 2989 * buffer overflows. 2990 * 2991 * See the vsnprintf() documentation for format string extensions over C99. 2992 */ 2993 int sprintf(char *buf, const char *fmt, ...) 2994 { 2995 va_list args; 2996 int i; 2997 2998 va_start(args, fmt); 2999 i = vsnprintf(buf, INT_MAX, fmt, args); 3000 va_end(args); 3001 3002 return i; 3003 } 3004 EXPORT_SYMBOL(sprintf); 3005 3006 #ifdef CONFIG_BINARY_PRINTF 3007 /* 3008 * bprintf service: 3009 * vbin_printf() - VA arguments to binary data 3010 * bstr_printf() - Binary data to text string 3011 */ 3012 3013 /** 3014 * vbin_printf - Parse a format string and place args' binary value in a buffer 3015 * @bin_buf: The buffer to place args' binary value 3016 * @size: The size of the buffer(by words(32bits), not characters) 3017 * @fmt: The format string to use 3018 * @args: Arguments for the format string 3019 * 3020 * The format follows C99 vsnprintf, except %n is ignored, and its argument 3021 * is skipped. 3022 * 3023 * The return value is the number of words(32bits) which would be generated for 3024 * the given input. 3025 * 3026 * NOTE: 3027 * If the return value is greater than @size, the resulting bin_buf is NOT 3028 * valid for bstr_printf(). 3029 */ 3030 int vbin_printf(u32 *bin_buf, size_t size, const char *fmt, va_list args) 3031 { 3032 struct printf_spec spec = {0}; 3033 char *str, *end; 3034 int width; 3035 3036 str = (char *)bin_buf; 3037 end = (char *)(bin_buf + size); 3038 3039 #define save_arg(type) \ 3040 ({ \ 3041 unsigned long long value; \ 3042 if (sizeof(type) == 8) { \ 3043 unsigned long long val8; \ 3044 str = PTR_ALIGN(str, sizeof(u32)); \ 3045 val8 = va_arg(args, unsigned long long); \ 3046 if (str + sizeof(type) <= end) { \ 3047 *(u32 *)str = *(u32 *)&val8; \ 3048 *(u32 *)(str + 4) = *((u32 *)&val8 + 1); \ 3049 } \ 3050 value = val8; \ 3051 } else { \ 3052 unsigned int val4; \ 3053 str = PTR_ALIGN(str, sizeof(type)); \ 3054 val4 = va_arg(args, int); \ 3055 if (str + sizeof(type) <= end) \ 3056 *(typeof(type) *)str = (type)(long)val4; \ 3057 value = (unsigned long long)val4; \ 3058 } \ 3059 str += sizeof(type); \ 3060 value; \ 3061 }) 3062 3063 while (*fmt) { 3064 int read = format_decode(fmt, &spec); 3065 3066 fmt += read; 3067 3068 switch (spec.type) { 3069 case FORMAT_TYPE_NONE: 3070 case FORMAT_TYPE_PERCENT_CHAR: 3071 break; 3072 case FORMAT_TYPE_INVALID: 3073 goto out; 3074 3075 case FORMAT_TYPE_WIDTH: 3076 case FORMAT_TYPE_PRECISION: 3077 width = (int)save_arg(int); 3078 /* Pointers may require the width */ 3079 if (*fmt == 'p') 3080 set_field_width(&spec, width); 3081 break; 3082 3083 case FORMAT_TYPE_CHAR: 3084 save_arg(char); 3085 break; 3086 3087 case FORMAT_TYPE_STR: { 3088 const char *save_str = va_arg(args, char *); 3089 const char *err_msg; 3090 size_t len; 3091 3092 err_msg = check_pointer_msg(save_str); 3093 if (err_msg) 3094 save_str = err_msg; 3095 3096 len = strlen(save_str) + 1; 3097 if (str + len < end) 3098 memcpy(str, save_str, len); 3099 str += len; 3100 break; 3101 } 3102 3103 case FORMAT_TYPE_PTR: 3104 /* Dereferenced pointers must be done now */ 3105 switch (*fmt) { 3106 /* Dereference of functions is still OK */ 3107 case 'S': 3108 case 's': 3109 case 'x': 3110 case 'K': 3111 case 'e': 3112 save_arg(void *); 3113 break; 3114 default: 3115 if (!isalnum(*fmt)) { 3116 save_arg(void *); 3117 break; 3118 } 3119 str = pointer(fmt, str, end, va_arg(args, void *), 3120 spec); 3121 if (str + 1 < end) 3122 *str++ = '\0'; 3123 else 3124 end[-1] = '\0'; /* Must be nul terminated */ 3125 } 3126 /* skip all alphanumeric pointer suffixes */ 3127 while (isalnum(*fmt)) 3128 fmt++; 3129 break; 3130 3131 default: 3132 switch (spec.type) { 3133 3134 case FORMAT_TYPE_LONG_LONG: 3135 save_arg(long long); 3136 break; 3137 case FORMAT_TYPE_ULONG: 3138 case FORMAT_TYPE_LONG: 3139 save_arg(unsigned long); 3140 break; 3141 case FORMAT_TYPE_SIZE_T: 3142 save_arg(size_t); 3143 break; 3144 case FORMAT_TYPE_PTRDIFF: 3145 save_arg(ptrdiff_t); 3146 break; 3147 case FORMAT_TYPE_UBYTE: 3148 case FORMAT_TYPE_BYTE: 3149 save_arg(char); 3150 break; 3151 case FORMAT_TYPE_USHORT: 3152 case FORMAT_TYPE_SHORT: 3153 save_arg(short); 3154 break; 3155 default: 3156 save_arg(int); 3157 } 3158 } 3159 } 3160 3161 out: 3162 return (u32 *)(PTR_ALIGN(str, sizeof(u32))) - bin_buf; 3163 #undef save_arg 3164 } 3165 EXPORT_SYMBOL_GPL(vbin_printf); 3166 3167 /** 3168 * bstr_printf - Format a string from binary arguments and place it in a buffer 3169 * @buf: The buffer to place the result into 3170 * @size: The size of the buffer, including the trailing null space 3171 * @fmt: The format string to use 3172 * @bin_buf: Binary arguments for the format string 3173 * 3174 * This function like C99 vsnprintf, but the difference is that vsnprintf gets 3175 * arguments from stack, and bstr_printf gets arguments from @bin_buf which is 3176 * a binary buffer that generated by vbin_printf. 3177 * 3178 * The format follows C99 vsnprintf, but has some extensions: 3179 * see vsnprintf comment for details. 3180 * 3181 * The return value is the number of characters which would 3182 * be generated for the given input, excluding the trailing 3183 * '\0', as per ISO C99. If you want to have the exact 3184 * number of characters written into @buf as return value 3185 * (not including the trailing '\0'), use vscnprintf(). If the 3186 * return is greater than or equal to @size, the resulting 3187 * string is truncated. 3188 */ 3189 int bstr_printf(char *buf, size_t size, const char *fmt, const u32 *bin_buf) 3190 { 3191 struct printf_spec spec = {0}; 3192 char *str, *end; 3193 const char *args = (const char *)bin_buf; 3194 3195 if (WARN_ON_ONCE(size > INT_MAX)) 3196 return 0; 3197 3198 str = buf; 3199 end = buf + size; 3200 3201 #define get_arg(type) \ 3202 ({ \ 3203 typeof(type) value; \ 3204 if (sizeof(type) == 8) { \ 3205 args = PTR_ALIGN(args, sizeof(u32)); \ 3206 *(u32 *)&value = *(u32 *)args; \ 3207 *((u32 *)&value + 1) = *(u32 *)(args + 4); \ 3208 } else { \ 3209 args = PTR_ALIGN(args, sizeof(type)); \ 3210 value = *(typeof(type) *)args; \ 3211 } \ 3212 args += sizeof(type); \ 3213 value; \ 3214 }) 3215 3216 /* Make sure end is always >= buf */ 3217 if (end < buf) { 3218 end = ((void *)-1); 3219 size = end - buf; 3220 } 3221 3222 while (*fmt) { 3223 const char *old_fmt = fmt; 3224 int read = format_decode(fmt, &spec); 3225 3226 fmt += read; 3227 3228 switch (spec.type) { 3229 case FORMAT_TYPE_NONE: { 3230 int copy = read; 3231 if (str < end) { 3232 if (copy > end - str) 3233 copy = end - str; 3234 memcpy(str, old_fmt, copy); 3235 } 3236 str += read; 3237 break; 3238 } 3239 3240 case FORMAT_TYPE_WIDTH: 3241 set_field_width(&spec, get_arg(int)); 3242 break; 3243 3244 case FORMAT_TYPE_PRECISION: 3245 set_precision(&spec, get_arg(int)); 3246 break; 3247 3248 case FORMAT_TYPE_CHAR: { 3249 char c; 3250 3251 if (!(spec.flags & LEFT)) { 3252 while (--spec.field_width > 0) { 3253 if (str < end) 3254 *str = ' '; 3255 ++str; 3256 } 3257 } 3258 c = (unsigned char) get_arg(char); 3259 if (str < end) 3260 *str = c; 3261 ++str; 3262 while (--spec.field_width > 0) { 3263 if (str < end) 3264 *str = ' '; 3265 ++str; 3266 } 3267 break; 3268 } 3269 3270 case FORMAT_TYPE_STR: { 3271 const char *str_arg = args; 3272 args += strlen(str_arg) + 1; 3273 str = string(str, end, (char *)str_arg, spec); 3274 break; 3275 } 3276 3277 case FORMAT_TYPE_PTR: { 3278 bool process = false; 3279 int copy, len; 3280 /* Non function dereferences were already done */ 3281 switch (*fmt) { 3282 case 'S': 3283 case 's': 3284 case 'x': 3285 case 'K': 3286 case 'e': 3287 process = true; 3288 break; 3289 default: 3290 if (!isalnum(*fmt)) { 3291 process = true; 3292 break; 3293 } 3294 /* Pointer dereference was already processed */ 3295 if (str < end) { 3296 len = copy = strlen(args); 3297 if (copy > end - str) 3298 copy = end - str; 3299 memcpy(str, args, copy); 3300 str += len; 3301 args += len + 1; 3302 } 3303 } 3304 if (process) 3305 str = pointer(fmt, str, end, get_arg(void *), spec); 3306 3307 while (isalnum(*fmt)) 3308 fmt++; 3309 break; 3310 } 3311 3312 case FORMAT_TYPE_PERCENT_CHAR: 3313 if (str < end) 3314 *str = '%'; 3315 ++str; 3316 break; 3317 3318 case FORMAT_TYPE_INVALID: 3319 goto out; 3320 3321 default: { 3322 unsigned long long num; 3323 3324 switch (spec.type) { 3325 3326 case FORMAT_TYPE_LONG_LONG: 3327 num = get_arg(long long); 3328 break; 3329 case FORMAT_TYPE_ULONG: 3330 case FORMAT_TYPE_LONG: 3331 num = get_arg(unsigned long); 3332 break; 3333 case FORMAT_TYPE_SIZE_T: 3334 num = get_arg(size_t); 3335 break; 3336 case FORMAT_TYPE_PTRDIFF: 3337 num = get_arg(ptrdiff_t); 3338 break; 3339 case FORMAT_TYPE_UBYTE: 3340 num = get_arg(unsigned char); 3341 break; 3342 case FORMAT_TYPE_BYTE: 3343 num = get_arg(signed char); 3344 break; 3345 case FORMAT_TYPE_USHORT: 3346 num = get_arg(unsigned short); 3347 break; 3348 case FORMAT_TYPE_SHORT: 3349 num = get_arg(short); 3350 break; 3351 case FORMAT_TYPE_UINT: 3352 num = get_arg(unsigned int); 3353 break; 3354 default: 3355 num = get_arg(int); 3356 } 3357 3358 str = number(str, end, num, spec); 3359 } /* default: */ 3360 } /* switch(spec.type) */ 3361 } /* while(*fmt) */ 3362 3363 out: 3364 if (size > 0) { 3365 if (str < end) 3366 *str = '\0'; 3367 else 3368 end[-1] = '\0'; 3369 } 3370 3371 #undef get_arg 3372 3373 /* the trailing null byte doesn't count towards the total */ 3374 return str - buf; 3375 } 3376 EXPORT_SYMBOL_GPL(bstr_printf); 3377 3378 /** 3379 * bprintf - Parse a format string and place args' binary value in a buffer 3380 * @bin_buf: The buffer to place args' binary value 3381 * @size: The size of the buffer(by words(32bits), not characters) 3382 * @fmt: The format string to use 3383 * @...: Arguments for the format string 3384 * 3385 * The function returns the number of words(u32) written 3386 * into @bin_buf. 3387 */ 3388 int bprintf(u32 *bin_buf, size_t size, const char *fmt, ...) 3389 { 3390 va_list args; 3391 int ret; 3392 3393 va_start(args, fmt); 3394 ret = vbin_printf(bin_buf, size, fmt, args); 3395 va_end(args); 3396 3397 return ret; 3398 } 3399 EXPORT_SYMBOL_GPL(bprintf); 3400 3401 #endif /* CONFIG_BINARY_PRINTF */ 3402 3403 /** 3404 * vsscanf - Unformat a buffer into a list of arguments 3405 * @buf: input buffer 3406 * @fmt: format of buffer 3407 * @args: arguments 3408 */ 3409 int vsscanf(const char *buf, const char *fmt, va_list args) 3410 { 3411 const char *str = buf; 3412 char *next; 3413 char digit; 3414 int num = 0; 3415 u8 qualifier; 3416 unsigned int base; 3417 union { 3418 long long s; 3419 unsigned long long u; 3420 } val; 3421 s16 field_width; 3422 bool is_sign; 3423 3424 while (*fmt) { 3425 /* skip any white space in format */ 3426 /* white space in format matches any amount of 3427 * white space, including none, in the input. 3428 */ 3429 if (isspace(*fmt)) { 3430 fmt = skip_spaces(++fmt); 3431 str = skip_spaces(str); 3432 } 3433 3434 /* anything that is not a conversion must match exactly */ 3435 if (*fmt != '%' && *fmt) { 3436 if (*fmt++ != *str++) 3437 break; 3438 continue; 3439 } 3440 3441 if (!*fmt) 3442 break; 3443 ++fmt; 3444 3445 /* skip this conversion. 3446 * advance both strings to next white space 3447 */ 3448 if (*fmt == '*') { 3449 if (!*str) 3450 break; 3451 while (!isspace(*fmt) && *fmt != '%' && *fmt) { 3452 /* '%*[' not yet supported, invalid format */ 3453 if (*fmt == '[') 3454 return num; 3455 fmt++; 3456 } 3457 while (!isspace(*str) && *str) 3458 str++; 3459 continue; 3460 } 3461 3462 /* get field width */ 3463 field_width = -1; 3464 if (isdigit(*fmt)) { 3465 field_width = skip_atoi(&fmt); 3466 if (field_width <= 0) 3467 break; 3468 } 3469 3470 /* get conversion qualifier */ 3471 qualifier = -1; 3472 if (*fmt == 'h' || _tolower(*fmt) == 'l' || 3473 *fmt == 'z') { 3474 qualifier = *fmt++; 3475 if (unlikely(qualifier == *fmt)) { 3476 if (qualifier == 'h') { 3477 qualifier = 'H'; 3478 fmt++; 3479 } else if (qualifier == 'l') { 3480 qualifier = 'L'; 3481 fmt++; 3482 } 3483 } 3484 } 3485 3486 if (!*fmt) 3487 break; 3488 3489 if (*fmt == 'n') { 3490 /* return number of characters read so far */ 3491 *va_arg(args, int *) = str - buf; 3492 ++fmt; 3493 continue; 3494 } 3495 3496 if (!*str) 3497 break; 3498 3499 base = 10; 3500 is_sign = false; 3501 3502 switch (*fmt++) { 3503 case 'c': 3504 { 3505 char *s = (char *)va_arg(args, char*); 3506 if (field_width == -1) 3507 field_width = 1; 3508 do { 3509 *s++ = *str++; 3510 } while (--field_width > 0 && *str); 3511 num++; 3512 } 3513 continue; 3514 case 's': 3515 { 3516 char *s = (char *)va_arg(args, char *); 3517 if (field_width == -1) 3518 field_width = SHRT_MAX; 3519 /* first, skip leading white space in buffer */ 3520 str = skip_spaces(str); 3521 3522 /* now copy until next white space */ 3523 while (*str && !isspace(*str) && field_width--) 3524 *s++ = *str++; 3525 *s = '\0'; 3526 num++; 3527 } 3528 continue; 3529 /* 3530 * Warning: This implementation of the '[' conversion specifier 3531 * deviates from its glibc counterpart in the following ways: 3532 * (1) It does NOT support ranges i.e. '-' is NOT a special 3533 * character 3534 * (2) It cannot match the closing bracket ']' itself 3535 * (3) A field width is required 3536 * (4) '%*[' (discard matching input) is currently not supported 3537 * 3538 * Example usage: 3539 * ret = sscanf("00:0a:95","%2[^:]:%2[^:]:%2[^:]", 3540 * buf1, buf2, buf3); 3541 * if (ret < 3) 3542 * // etc.. 3543 */ 3544 case '[': 3545 { 3546 char *s = (char *)va_arg(args, char *); 3547 DECLARE_BITMAP(set, 256) = {0}; 3548 unsigned int len = 0; 3549 bool negate = (*fmt == '^'); 3550 3551 /* field width is required */ 3552 if (field_width == -1) 3553 return num; 3554 3555 if (negate) 3556 ++fmt; 3557 3558 for ( ; *fmt && *fmt != ']'; ++fmt, ++len) 3559 set_bit((u8)*fmt, set); 3560 3561 /* no ']' or no character set found */ 3562 if (!*fmt || !len) 3563 return num; 3564 ++fmt; 3565 3566 if (negate) { 3567 bitmap_complement(set, set, 256); 3568 /* exclude null '\0' byte */ 3569 clear_bit(0, set); 3570 } 3571 3572 /* match must be non-empty */ 3573 if (!test_bit((u8)*str, set)) 3574 return num; 3575 3576 while (test_bit((u8)*str, set) && field_width--) 3577 *s++ = *str++; 3578 *s = '\0'; 3579 ++num; 3580 } 3581 continue; 3582 case 'o': 3583 base = 8; 3584 break; 3585 case 'x': 3586 case 'X': 3587 base = 16; 3588 break; 3589 case 'i': 3590 base = 0; 3591 fallthrough; 3592 case 'd': 3593 is_sign = true; 3594 fallthrough; 3595 case 'u': 3596 break; 3597 case '%': 3598 /* looking for '%' in str */ 3599 if (*str++ != '%') 3600 return num; 3601 continue; 3602 default: 3603 /* invalid format; stop here */ 3604 return num; 3605 } 3606 3607 /* have some sort of integer conversion. 3608 * first, skip white space in buffer. 3609 */ 3610 str = skip_spaces(str); 3611 3612 digit = *str; 3613 if (is_sign && digit == '-') { 3614 if (field_width == 1) 3615 break; 3616 3617 digit = *(str + 1); 3618 } 3619 3620 if (!digit 3621 || (base == 16 && !isxdigit(digit)) 3622 || (base == 10 && !isdigit(digit)) 3623 || (base == 8 && (!isdigit(digit) || digit > '7')) 3624 || (base == 0 && !isdigit(digit))) 3625 break; 3626 3627 if (is_sign) 3628 val.s = simple_strntoll(str, 3629 field_width >= 0 ? field_width : INT_MAX, 3630 &next, base); 3631 else 3632 val.u = simple_strntoull(str, 3633 field_width >= 0 ? field_width : INT_MAX, 3634 &next, base); 3635 3636 switch (qualifier) { 3637 case 'H': /* that's 'hh' in format */ 3638 if (is_sign) 3639 *va_arg(args, signed char *) = val.s; 3640 else 3641 *va_arg(args, unsigned char *) = val.u; 3642 break; 3643 case 'h': 3644 if (is_sign) 3645 *va_arg(args, short *) = val.s; 3646 else 3647 *va_arg(args, unsigned short *) = val.u; 3648 break; 3649 case 'l': 3650 if (is_sign) 3651 *va_arg(args, long *) = val.s; 3652 else 3653 *va_arg(args, unsigned long *) = val.u; 3654 break; 3655 case 'L': 3656 if (is_sign) 3657 *va_arg(args, long long *) = val.s; 3658 else 3659 *va_arg(args, unsigned long long *) = val.u; 3660 break; 3661 case 'z': 3662 *va_arg(args, size_t *) = val.u; 3663 break; 3664 default: 3665 if (is_sign) 3666 *va_arg(args, int *) = val.s; 3667 else 3668 *va_arg(args, unsigned int *) = val.u; 3669 break; 3670 } 3671 num++; 3672 3673 if (!next) 3674 break; 3675 str = next; 3676 } 3677 3678 return num; 3679 } 3680 EXPORT_SYMBOL(vsscanf); 3681 3682 /** 3683 * sscanf - Unformat a buffer into a list of arguments 3684 * @buf: input buffer 3685 * @fmt: formatting of buffer 3686 * @...: resulting arguments 3687 */ 3688 int sscanf(const char *buf, const char *fmt, ...) 3689 { 3690 va_list args; 3691 int i; 3692 3693 va_start(args, fmt); 3694 i = vsscanf(buf, fmt, args); 3695 va_end(args); 3696 3697 return i; 3698 } 3699 EXPORT_SYMBOL(sscanf); 3700