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