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