1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * linux/lib/vsprintf.c 4 * 5 * Copyright (C) 1991, 1992 Linus Torvalds 6 */ 7 8 /* vsprintf.c -- Lars Wirzenius & Linus Torvalds. */ 9 /* 10 * Wirzenius wrote this portably, Torvalds fucked it up :-) 11 */ 12 13 /* 14 * Fri Jul 13 2001 Crutcher Dunnavant <crutcher+kernel@datastacks.com> 15 * - changed to provide snprintf and vsnprintf functions 16 * So Feb 1 16:51:32 CET 2004 Juergen Quade <quade@hsnr.de> 17 * - scnprintf and vscnprintf 18 */ 19 20 #include <stdarg.h> 21 #include <linux/build_bug.h> 22 #include <linux/clk.h> 23 #include <linux/clk-provider.h> 24 #include <linux/errname.h> 25 #include <linux/module.h> /* for KSYM_SYMBOL_LEN */ 26 #include <linux/types.h> 27 #include <linux/string.h> 28 #include <linux/ctype.h> 29 #include <linux/kernel.h> 30 #include <linux/kallsyms.h> 31 #include <linux/math64.h> 32 #include <linux/uaccess.h> 33 #include <linux/ioport.h> 34 #include <linux/dcache.h> 35 #include <linux/cred.h> 36 #include <linux/rtc.h> 37 #include <linux/time.h> 38 #include <linux/uuid.h> 39 #include <linux/of.h> 40 #include <net/addrconf.h> 41 #include <linux/siphash.h> 42 #include <linux/compiler.h> 43 #include <linux/property.h> 44 #ifdef CONFIG_BLOCK 45 #include <linux/blkdev.h> 46 #endif 47 48 #include "../mm/internal.h" /* For the trace_print_flags arrays */ 49 50 #include <asm/page.h> /* for PAGE_SIZE */ 51 #include <asm/byteorder.h> /* cpu_to_le16 */ 52 53 #include <linux/string_helpers.h> 54 #include "kstrtox.h" 55 56 /** 57 * simple_strtoull - convert a string to an unsigned long long 58 * @cp: The start of the string 59 * @endp: A pointer to the end of the parsed string will be placed here 60 * @base: The number base to use 61 * 62 * This function has caveats. Please use kstrtoull instead. 63 */ 64 unsigned long long simple_strtoull(const char *cp, char **endp, unsigned int base) 65 { 66 unsigned long long result; 67 unsigned int rv; 68 69 cp = _parse_integer_fixup_radix(cp, &base); 70 rv = _parse_integer(cp, base, &result); 71 /* FIXME */ 72 cp += (rv & ~KSTRTOX_OVERFLOW); 73 74 if (endp) 75 *endp = (char *)cp; 76 77 return result; 78 } 79 EXPORT_SYMBOL(simple_strtoull); 80 81 /** 82 * simple_strtoul - convert a string to an unsigned long 83 * @cp: The start of the string 84 * @endp: A pointer to the end of the parsed string will be placed here 85 * @base: The number base to use 86 * 87 * This function has caveats. Please use kstrtoul instead. 88 */ 89 unsigned long simple_strtoul(const char *cp, char **endp, unsigned int base) 90 { 91 return simple_strtoull(cp, endp, base); 92 } 93 EXPORT_SYMBOL(simple_strtoul); 94 95 /** 96 * simple_strtol - convert a string to a signed 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 kstrtol instead. 102 */ 103 long simple_strtol(const char *cp, char **endp, unsigned int base) 104 { 105 if (*cp == '-') 106 return -simple_strtoul(cp + 1, endp, base); 107 108 return simple_strtoul(cp, endp, base); 109 } 110 EXPORT_SYMBOL(simple_strtol); 111 112 /** 113 * simple_strtoll - convert a string to a signed long long 114 * @cp: The start of the string 115 * @endp: A pointer to the end of the parsed string will be placed here 116 * @base: The number base to use 117 * 118 * This function has caveats. Please use kstrtoll instead. 119 */ 120 long long simple_strtoll(const char *cp, char **endp, unsigned int base) 121 { 122 if (*cp == '-') 123 return -simple_strtoull(cp + 1, endp, base); 124 125 return simple_strtoull(cp, endp, base); 126 } 127 EXPORT_SYMBOL(simple_strtoll); 128 129 static noinline_for_stack 130 int skip_atoi(const char **s) 131 { 132 int i = 0; 133 134 do { 135 i = i*10 + *((*s)++) - '0'; 136 } while (isdigit(**s)); 137 138 return i; 139 } 140 141 /* 142 * Decimal conversion is by far the most typical, and is used for 143 * /proc and /sys data. This directly impacts e.g. top performance 144 * with many processes running. We optimize it for speed by emitting 145 * two characters at a time, using a 200 byte lookup table. This 146 * roughly halves the number of multiplications compared to computing 147 * the digits one at a time. Implementation strongly inspired by the 148 * previous version, which in turn used ideas described at 149 * <http://www.cs.uiowa.edu/~jones/bcd/divide.html> (with permission 150 * from the author, Douglas W. Jones). 151 * 152 * It turns out there is precisely one 26 bit fixed-point 153 * approximation a of 64/100 for which x/100 == (x * (u64)a) >> 32 154 * holds for all x in [0, 10^8-1], namely a = 0x28f5c29. The actual 155 * range happens to be somewhat larger (x <= 1073741898), but that's 156 * irrelevant for our purpose. 157 * 158 * For dividing a number in the range [10^4, 10^6-1] by 100, we still 159 * need a 32x32->64 bit multiply, so we simply use the same constant. 160 * 161 * For dividing a number in the range [100, 10^4-1] by 100, there are 162 * several options. The simplest is (x * 0x147b) >> 19, which is valid 163 * for all x <= 43698. 164 */ 165 166 static const u16 decpair[100] = { 167 #define _(x) (__force u16) cpu_to_le16(((x % 10) | ((x / 10) << 8)) + 0x3030) 168 _( 0), _( 1), _( 2), _( 3), _( 4), _( 5), _( 6), _( 7), _( 8), _( 9), 169 _(10), _(11), _(12), _(13), _(14), _(15), _(16), _(17), _(18), _(19), 170 _(20), _(21), _(22), _(23), _(24), _(25), _(26), _(27), _(28), _(29), 171 _(30), _(31), _(32), _(33), _(34), _(35), _(36), _(37), _(38), _(39), 172 _(40), _(41), _(42), _(43), _(44), _(45), _(46), _(47), _(48), _(49), 173 _(50), _(51), _(52), _(53), _(54), _(55), _(56), _(57), _(58), _(59), 174 _(60), _(61), _(62), _(63), _(64), _(65), _(66), _(67), _(68), _(69), 175 _(70), _(71), _(72), _(73), _(74), _(75), _(76), _(77), _(78), _(79), 176 _(80), _(81), _(82), _(83), _(84), _(85), _(86), _(87), _(88), _(89), 177 _(90), _(91), _(92), _(93), _(94), _(95), _(96), _(97), _(98), _(99), 178 #undef _ 179 }; 180 181 /* 182 * This will print a single '0' even if r == 0, since we would 183 * immediately jump to out_r where two 0s would be written but only 184 * one of them accounted for in buf. This is needed by ip4_string 185 * below. All other callers pass a non-zero value of r. 186 */ 187 static noinline_for_stack 188 char *put_dec_trunc8(char *buf, unsigned r) 189 { 190 unsigned q; 191 192 /* 1 <= r < 10^8 */ 193 if (r < 100) 194 goto out_r; 195 196 /* 100 <= r < 10^8 */ 197 q = (r * (u64)0x28f5c29) >> 32; 198 *((u16 *)buf) = decpair[r - 100*q]; 199 buf += 2; 200 201 /* 1 <= q < 10^6 */ 202 if (q < 100) 203 goto out_q; 204 205 /* 100 <= q < 10^6 */ 206 r = (q * (u64)0x28f5c29) >> 32; 207 *((u16 *)buf) = decpair[q - 100*r]; 208 buf += 2; 209 210 /* 1 <= r < 10^4 */ 211 if (r < 100) 212 goto out_r; 213 214 /* 100 <= r < 10^4 */ 215 q = (r * 0x147b) >> 19; 216 *((u16 *)buf) = decpair[r - 100*q]; 217 buf += 2; 218 out_q: 219 /* 1 <= q < 100 */ 220 r = q; 221 out_r: 222 /* 1 <= r < 100 */ 223 *((u16 *)buf) = decpair[r]; 224 buf += r < 10 ? 1 : 2; 225 return buf; 226 } 227 228 #if BITS_PER_LONG == 64 && BITS_PER_LONG_LONG == 64 229 static noinline_for_stack 230 char *put_dec_full8(char *buf, unsigned r) 231 { 232 unsigned q; 233 234 /* 0 <= r < 10^8 */ 235 q = (r * (u64)0x28f5c29) >> 32; 236 *((u16 *)buf) = decpair[r - 100*q]; 237 buf += 2; 238 239 /* 0 <= q < 10^6 */ 240 r = (q * (u64)0x28f5c29) >> 32; 241 *((u16 *)buf) = decpair[q - 100*r]; 242 buf += 2; 243 244 /* 0 <= r < 10^4 */ 245 q = (r * 0x147b) >> 19; 246 *((u16 *)buf) = decpair[r - 100*q]; 247 buf += 2; 248 249 /* 0 <= q < 100 */ 250 *((u16 *)buf) = decpair[q]; 251 buf += 2; 252 return buf; 253 } 254 255 static noinline_for_stack 256 char *put_dec(char *buf, unsigned long long n) 257 { 258 if (n >= 100*1000*1000) 259 buf = put_dec_full8(buf, do_div(n, 100*1000*1000)); 260 /* 1 <= n <= 1.6e11 */ 261 if (n >= 100*1000*1000) 262 buf = put_dec_full8(buf, do_div(n, 100*1000*1000)); 263 /* 1 <= n < 1e8 */ 264 return put_dec_trunc8(buf, n); 265 } 266 267 #elif BITS_PER_LONG == 32 && BITS_PER_LONG_LONG == 64 268 269 static void 270 put_dec_full4(char *buf, unsigned r) 271 { 272 unsigned q; 273 274 /* 0 <= r < 10^4 */ 275 q = (r * 0x147b) >> 19; 276 *((u16 *)buf) = decpair[r - 100*q]; 277 buf += 2; 278 /* 0 <= q < 100 */ 279 *((u16 *)buf) = decpair[q]; 280 } 281 282 /* 283 * Call put_dec_full4 on x % 10000, return x / 10000. 284 * The approximation x/10000 == (x * 0x346DC5D7) >> 43 285 * holds for all x < 1,128,869,999. The largest value this 286 * helper will ever be asked to convert is 1,125,520,955. 287 * (second call in the put_dec code, assuming n is all-ones). 288 */ 289 static noinline_for_stack 290 unsigned put_dec_helper4(char *buf, unsigned x) 291 { 292 uint32_t q = (x * (uint64_t)0x346DC5D7) >> 43; 293 294 put_dec_full4(buf, x - q * 10000); 295 return q; 296 } 297 298 /* Based on code by Douglas W. Jones found at 299 * <http://www.cs.uiowa.edu/~jones/bcd/decimal.html#sixtyfour> 300 * (with permission from the author). 301 * Performs no 64-bit division and hence should be fast on 32-bit machines. 302 */ 303 static 304 char *put_dec(char *buf, unsigned long long n) 305 { 306 uint32_t d3, d2, d1, q, h; 307 308 if (n < 100*1000*1000) 309 return put_dec_trunc8(buf, n); 310 311 d1 = ((uint32_t)n >> 16); /* implicit "& 0xffff" */ 312 h = (n >> 32); 313 d2 = (h ) & 0xffff; 314 d3 = (h >> 16); /* implicit "& 0xffff" */ 315 316 /* n = 2^48 d3 + 2^32 d2 + 2^16 d1 + d0 317 = 281_4749_7671_0656 d3 + 42_9496_7296 d2 + 6_5536 d1 + d0 */ 318 q = 656 * d3 + 7296 * d2 + 5536 * d1 + ((uint32_t)n & 0xffff); 319 q = put_dec_helper4(buf, q); 320 321 q += 7671 * d3 + 9496 * d2 + 6 * d1; 322 q = put_dec_helper4(buf+4, q); 323 324 q += 4749 * d3 + 42 * d2; 325 q = put_dec_helper4(buf+8, q); 326 327 q += 281 * d3; 328 buf += 12; 329 if (q) 330 buf = put_dec_trunc8(buf, q); 331 else while (buf[-1] == '0') 332 --buf; 333 334 return buf; 335 } 336 337 #endif 338 339 /* 340 * Convert passed number to decimal string. 341 * Returns the length of string. On buffer overflow, returns 0. 342 * 343 * If speed is not important, use snprintf(). It's easy to read the code. 344 */ 345 int num_to_str(char *buf, int size, unsigned long long num, unsigned int width) 346 { 347 /* put_dec requires 2-byte alignment of the buffer. */ 348 char tmp[sizeof(num) * 3] __aligned(2); 349 int idx, len; 350 351 /* put_dec() may work incorrectly for num = 0 (generate "", not "0") */ 352 if (num <= 9) { 353 tmp[0] = '0' + num; 354 len = 1; 355 } else { 356 len = put_dec(tmp, num) - tmp; 357 } 358 359 if (len > size || width > size) 360 return 0; 361 362 if (width > len) { 363 width = width - len; 364 for (idx = 0; idx < width; idx++) 365 buf[idx] = ' '; 366 } else { 367 width = 0; 368 } 369 370 for (idx = 0; idx < len; ++idx) 371 buf[idx + width] = tmp[len - idx - 1]; 372 373 return len + width; 374 } 375 376 #define SIGN 1 /* unsigned/signed, must be 1 */ 377 #define LEFT 2 /* left justified */ 378 #define PLUS 4 /* show plus */ 379 #define SPACE 8 /* space if plus */ 380 #define ZEROPAD 16 /* pad with zero, must be 16 == '0' - ' ' */ 381 #define SMALL 32 /* use lowercase in hex (must be 32 == 0x20) */ 382 #define SPECIAL 64 /* prefix hex with "0x", octal with "0" */ 383 384 static_assert(ZEROPAD == ('0' - ' ')); 385 static_assert(SMALL == ' '); 386 387 enum format_type { 388 FORMAT_TYPE_NONE, /* Just a string part */ 389 FORMAT_TYPE_WIDTH, 390 FORMAT_TYPE_PRECISION, 391 FORMAT_TYPE_CHAR, 392 FORMAT_TYPE_STR, 393 FORMAT_TYPE_PTR, 394 FORMAT_TYPE_PERCENT_CHAR, 395 FORMAT_TYPE_INVALID, 396 FORMAT_TYPE_LONG_LONG, 397 FORMAT_TYPE_ULONG, 398 FORMAT_TYPE_LONG, 399 FORMAT_TYPE_UBYTE, 400 FORMAT_TYPE_BYTE, 401 FORMAT_TYPE_USHORT, 402 FORMAT_TYPE_SHORT, 403 FORMAT_TYPE_UINT, 404 FORMAT_TYPE_INT, 405 FORMAT_TYPE_SIZE_T, 406 FORMAT_TYPE_PTRDIFF 407 }; 408 409 struct printf_spec { 410 unsigned int type:8; /* format_type enum */ 411 signed int field_width:24; /* width of output field */ 412 unsigned int flags:8; /* flags to number() */ 413 unsigned int base:8; /* number base, 8, 10 or 16 only */ 414 signed int precision:16; /* # of digits/chars */ 415 } __packed; 416 static_assert(sizeof(struct printf_spec) == 8); 417 418 #define FIELD_WIDTH_MAX ((1 << 23) - 1) 419 #define PRECISION_MAX ((1 << 15) - 1) 420 421 static noinline_for_stack 422 char *number(char *buf, char *end, unsigned long long num, 423 struct printf_spec spec) 424 { 425 /* put_dec requires 2-byte alignment of the buffer. */ 426 char tmp[3 * sizeof(num)] __aligned(2); 427 char sign; 428 char locase; 429 int need_pfx = ((spec.flags & SPECIAL) && spec.base != 10); 430 int i; 431 bool is_zero = num == 0LL; 432 int field_width = spec.field_width; 433 int precision = spec.precision; 434 435 /* locase = 0 or 0x20. ORing digits or letters with 'locase' 436 * produces same digits or (maybe lowercased) letters */ 437 locase = (spec.flags & SMALL); 438 if (spec.flags & LEFT) 439 spec.flags &= ~ZEROPAD; 440 sign = 0; 441 if (spec.flags & SIGN) { 442 if ((signed long long)num < 0) { 443 sign = '-'; 444 num = -(signed long long)num; 445 field_width--; 446 } else if (spec.flags & PLUS) { 447 sign = '+'; 448 field_width--; 449 } else if (spec.flags & SPACE) { 450 sign = ' '; 451 field_width--; 452 } 453 } 454 if (need_pfx) { 455 if (spec.base == 16) 456 field_width -= 2; 457 else if (!is_zero) 458 field_width--; 459 } 460 461 /* generate full string in tmp[], in reverse order */ 462 i = 0; 463 if (num < spec.base) 464 tmp[i++] = hex_asc_upper[num] | locase; 465 else if (spec.base != 10) { /* 8 or 16 */ 466 int mask = spec.base - 1; 467 int shift = 3; 468 469 if (spec.base == 16) 470 shift = 4; 471 do { 472 tmp[i++] = (hex_asc_upper[((unsigned char)num) & mask] | locase); 473 num >>= shift; 474 } while (num); 475 } else { /* base 10 */ 476 i = put_dec(tmp, num) - tmp; 477 } 478 479 /* printing 100 using %2d gives "100", not "00" */ 480 if (i > precision) 481 precision = i; 482 /* leading space padding */ 483 field_width -= precision; 484 if (!(spec.flags & (ZEROPAD | LEFT))) { 485 while (--field_width >= 0) { 486 if (buf < end) 487 *buf = ' '; 488 ++buf; 489 } 490 } 491 /* sign */ 492 if (sign) { 493 if (buf < end) 494 *buf = sign; 495 ++buf; 496 } 497 /* "0x" / "0" prefix */ 498 if (need_pfx) { 499 if (spec.base == 16 || !is_zero) { 500 if (buf < end) 501 *buf = '0'; 502 ++buf; 503 } 504 if (spec.base == 16) { 505 if (buf < end) 506 *buf = ('X' | locase); 507 ++buf; 508 } 509 } 510 /* zero or space padding */ 511 if (!(spec.flags & LEFT)) { 512 char c = ' ' + (spec.flags & ZEROPAD); 513 514 while (--field_width >= 0) { 515 if (buf < end) 516 *buf = c; 517 ++buf; 518 } 519 } 520 /* hmm even more zero padding? */ 521 while (i <= --precision) { 522 if (buf < end) 523 *buf = '0'; 524 ++buf; 525 } 526 /* actual digits of result */ 527 while (--i >= 0) { 528 if (buf < end) 529 *buf = tmp[i]; 530 ++buf; 531 } 532 /* trailing space padding */ 533 while (--field_width >= 0) { 534 if (buf < end) 535 *buf = ' '; 536 ++buf; 537 } 538 539 return buf; 540 } 541 542 static noinline_for_stack 543 char *special_hex_number(char *buf, char *end, unsigned long long num, int size) 544 { 545 struct printf_spec spec; 546 547 spec.type = FORMAT_TYPE_PTR; 548 spec.field_width = 2 + 2 * size; /* 0x + hex */ 549 spec.flags = SPECIAL | SMALL | ZEROPAD; 550 spec.base = 16; 551 spec.precision = -1; 552 553 return number(buf, end, num, spec); 554 } 555 556 static void move_right(char *buf, char *end, unsigned len, unsigned spaces) 557 { 558 size_t size; 559 if (buf >= end) /* nowhere to put anything */ 560 return; 561 size = end - buf; 562 if (size <= spaces) { 563 memset(buf, ' ', size); 564 return; 565 } 566 if (len) { 567 if (len > size - spaces) 568 len = size - spaces; 569 memmove(buf + spaces, buf, len); 570 } 571 memset(buf, ' ', spaces); 572 } 573 574 /* 575 * Handle field width padding for a string. 576 * @buf: current buffer position 577 * @n: length of string 578 * @end: end of output buffer 579 * @spec: for field width and flags 580 * Returns: new buffer position after padding. 581 */ 582 static noinline_for_stack 583 char *widen_string(char *buf, int n, char *end, struct printf_spec spec) 584 { 585 unsigned spaces; 586 587 if (likely(n >= spec.field_width)) 588 return buf; 589 /* we want to pad the sucker */ 590 spaces = spec.field_width - n; 591 if (!(spec.flags & LEFT)) { 592 move_right(buf - n, end, n, spaces); 593 return buf + spaces; 594 } 595 while (spaces--) { 596 if (buf < end) 597 *buf = ' '; 598 ++buf; 599 } 600 return buf; 601 } 602 603 /* Handle string from a well known address. */ 604 static char *string_nocheck(char *buf, char *end, const char *s, 605 struct printf_spec spec) 606 { 607 int len = 0; 608 int lim = spec.precision; 609 610 while (lim--) { 611 char c = *s++; 612 if (!c) 613 break; 614 if (buf < end) 615 *buf = c; 616 ++buf; 617 ++len; 618 } 619 return widen_string(buf, len, end, spec); 620 } 621 622 static char *err_ptr(char *buf, char *end, void *ptr, 623 struct printf_spec spec) 624 { 625 int err = PTR_ERR(ptr); 626 const char *sym = errname(err); 627 628 if (sym) 629 return string_nocheck(buf, end, sym, spec); 630 631 /* 632 * Somebody passed ERR_PTR(-1234) or some other non-existing 633 * Efoo - or perhaps CONFIG_SYMBOLIC_ERRNAME=n. Fall back to 634 * printing it as its decimal representation. 635 */ 636 spec.flags |= SIGN; 637 spec.base = 10; 638 return number(buf, end, err, spec); 639 } 640 641 /* Be careful: error messages must fit into the given buffer. */ 642 static char *error_string(char *buf, char *end, const char *s, 643 struct printf_spec spec) 644 { 645 /* 646 * Hard limit to avoid a completely insane messages. It actually 647 * works pretty well because most error messages are in 648 * the many pointer format modifiers. 649 */ 650 if (spec.precision == -1) 651 spec.precision = 2 * sizeof(void *); 652 653 return string_nocheck(buf, end, s, spec); 654 } 655 656 /* 657 * Do not call any complex external code here. Nested printk()/vsprintf() 658 * might cause infinite loops. Failures might break printk() and would 659 * be hard to debug. 660 */ 661 static const char *check_pointer_msg(const void *ptr) 662 { 663 if (!ptr) 664 return "(null)"; 665 666 if ((unsigned long)ptr < PAGE_SIZE || IS_ERR_VALUE(ptr)) 667 return "(efault)"; 668 669 return NULL; 670 } 671 672 static int check_pointer(char **buf, char *end, const void *ptr, 673 struct printf_spec spec) 674 { 675 const char *err_msg; 676 677 err_msg = check_pointer_msg(ptr); 678 if (err_msg) { 679 *buf = error_string(*buf, end, err_msg, spec); 680 return -EFAULT; 681 } 682 683 return 0; 684 } 685 686 static noinline_for_stack 687 char *string(char *buf, char *end, const char *s, 688 struct printf_spec spec) 689 { 690 if (check_pointer(&buf, end, s, spec)) 691 return buf; 692 693 return string_nocheck(buf, end, s, spec); 694 } 695 696 static char *pointer_string(char *buf, char *end, 697 const void *ptr, 698 struct printf_spec spec) 699 { 700 spec.base = 16; 701 spec.flags |= SMALL; 702 if (spec.field_width == -1) { 703 spec.field_width = 2 * sizeof(ptr); 704 spec.flags |= ZEROPAD; 705 } 706 707 return number(buf, end, (unsigned long int)ptr, spec); 708 } 709 710 /* Make pointers available for printing early in the boot sequence. */ 711 static int debug_boot_weak_hash __ro_after_init; 712 713 static int __init debug_boot_weak_hash_enable(char *str) 714 { 715 debug_boot_weak_hash = 1; 716 pr_info("debug_boot_weak_hash enabled\n"); 717 return 0; 718 } 719 early_param("debug_boot_weak_hash", debug_boot_weak_hash_enable); 720 721 static DEFINE_STATIC_KEY_TRUE(not_filled_random_ptr_key); 722 static siphash_key_t ptr_key __read_mostly; 723 724 static void enable_ptr_key_workfn(struct work_struct *work) 725 { 726 get_random_bytes(&ptr_key, sizeof(ptr_key)); 727 /* Needs to run from preemptible context */ 728 static_branch_disable(¬_filled_random_ptr_key); 729 } 730 731 static DECLARE_WORK(enable_ptr_key_work, enable_ptr_key_workfn); 732 733 static void fill_random_ptr_key(struct random_ready_callback *unused) 734 { 735 /* This may be in an interrupt handler. */ 736 queue_work(system_unbound_wq, &enable_ptr_key_work); 737 } 738 739 static struct random_ready_callback random_ready = { 740 .func = fill_random_ptr_key 741 }; 742 743 static int __init initialize_ptr_random(void) 744 { 745 int key_size = sizeof(ptr_key); 746 int ret; 747 748 /* Use hw RNG if available. */ 749 if (get_random_bytes_arch(&ptr_key, key_size) == key_size) { 750 static_branch_disable(¬_filled_random_ptr_key); 751 return 0; 752 } 753 754 ret = add_random_ready_callback(&random_ready); 755 if (!ret) { 756 return 0; 757 } else if (ret == -EALREADY) { 758 /* This is in preemptible context */ 759 enable_ptr_key_workfn(&enable_ptr_key_work); 760 return 0; 761 } 762 763 return ret; 764 } 765 early_initcall(initialize_ptr_random); 766 767 /* Maps a pointer to a 32 bit unique identifier. */ 768 static inline int __ptr_to_hashval(const void *ptr, unsigned long *hashval_out) 769 { 770 unsigned long hashval; 771 772 if (static_branch_unlikely(¬_filled_random_ptr_key)) 773 return -EAGAIN; 774 775 #ifdef CONFIG_64BIT 776 hashval = (unsigned long)siphash_1u64((u64)ptr, &ptr_key); 777 /* 778 * Mask off the first 32 bits, this makes explicit that we have 779 * modified the address (and 32 bits is plenty for a unique ID). 780 */ 781 hashval = hashval & 0xffffffff; 782 #else 783 hashval = (unsigned long)siphash_1u32((u32)ptr, &ptr_key); 784 #endif 785 *hashval_out = hashval; 786 return 0; 787 } 788 789 int ptr_to_hashval(const void *ptr, unsigned long *hashval_out) 790 { 791 return __ptr_to_hashval(ptr, hashval_out); 792 } 793 794 static char *ptr_to_id(char *buf, char *end, const void *ptr, 795 struct printf_spec spec) 796 { 797 const char *str = sizeof(ptr) == 8 ? "(____ptrval____)" : "(ptrval)"; 798 unsigned long hashval; 799 int ret; 800 801 /* 802 * Print the real pointer value for NULL and error pointers, 803 * as they are not actual addresses. 804 */ 805 if (IS_ERR_OR_NULL(ptr)) 806 return pointer_string(buf, end, ptr, spec); 807 808 /* When debugging early boot use non-cryptographically secure hash. */ 809 if (unlikely(debug_boot_weak_hash)) { 810 hashval = hash_long((unsigned long)ptr, 32); 811 return pointer_string(buf, end, (const void *)hashval, spec); 812 } 813 814 ret = __ptr_to_hashval(ptr, &hashval); 815 if (ret) { 816 spec.field_width = 2 * sizeof(ptr); 817 /* string length must be less than default_width */ 818 return error_string(buf, end, str, spec); 819 } 820 821 return pointer_string(buf, end, (const void *)hashval, spec); 822 } 823 824 int kptr_restrict __read_mostly; 825 826 static noinline_for_stack 827 char *restricted_pointer(char *buf, char *end, const void *ptr, 828 struct printf_spec spec) 829 { 830 switch (kptr_restrict) { 831 case 0: 832 /* Handle as %p, hash and do _not_ leak addresses. */ 833 return ptr_to_id(buf, end, ptr, spec); 834 case 1: { 835 const struct cred *cred; 836 837 /* 838 * kptr_restrict==1 cannot be used in IRQ context 839 * because its test for CAP_SYSLOG would be meaningless. 840 */ 841 if (in_irq() || in_serving_softirq() || in_nmi()) { 842 if (spec.field_width == -1) 843 spec.field_width = 2 * sizeof(ptr); 844 return error_string(buf, end, "pK-error", spec); 845 } 846 847 /* 848 * Only print the real pointer value if the current 849 * process has CAP_SYSLOG and is running with the 850 * same credentials it started with. This is because 851 * access to files is checked at open() time, but %pK 852 * checks permission at read() time. We don't want to 853 * leak pointer values if a binary opens a file using 854 * %pK and then elevates privileges before reading it. 855 */ 856 cred = current_cred(); 857 if (!has_capability_noaudit(current, CAP_SYSLOG) || 858 !uid_eq(cred->euid, cred->uid) || 859 !gid_eq(cred->egid, cred->gid)) 860 ptr = NULL; 861 break; 862 } 863 case 2: 864 default: 865 /* Always print 0's for %pK */ 866 ptr = NULL; 867 break; 868 } 869 870 return pointer_string(buf, end, ptr, spec); 871 } 872 873 static noinline_for_stack 874 char *dentry_name(char *buf, char *end, const struct dentry *d, struct printf_spec spec, 875 const char *fmt) 876 { 877 const char *array[4], *s; 878 const struct dentry *p; 879 int depth; 880 int i, n; 881 882 switch (fmt[1]) { 883 case '2': case '3': case '4': 884 depth = fmt[1] - '0'; 885 break; 886 default: 887 depth = 1; 888 } 889 890 rcu_read_lock(); 891 for (i = 0; i < depth; i++, d = p) { 892 if (check_pointer(&buf, end, d, spec)) { 893 rcu_read_unlock(); 894 return buf; 895 } 896 897 p = READ_ONCE(d->d_parent); 898 array[i] = READ_ONCE(d->d_name.name); 899 if (p == d) { 900 if (i) 901 array[i] = ""; 902 i++; 903 break; 904 } 905 } 906 s = array[--i]; 907 for (n = 0; n != spec.precision; n++, buf++) { 908 char c = *s++; 909 if (!c) { 910 if (!i) 911 break; 912 c = '/'; 913 s = array[--i]; 914 } 915 if (buf < end) 916 *buf = c; 917 } 918 rcu_read_unlock(); 919 return widen_string(buf, n, end, spec); 920 } 921 922 static noinline_for_stack 923 char *file_dentry_name(char *buf, char *end, const struct file *f, 924 struct printf_spec spec, const char *fmt) 925 { 926 if (check_pointer(&buf, end, f, spec)) 927 return buf; 928 929 return dentry_name(buf, end, f->f_path.dentry, spec, fmt); 930 } 931 #ifdef CONFIG_BLOCK 932 static noinline_for_stack 933 char *bdev_name(char *buf, char *end, struct block_device *bdev, 934 struct printf_spec spec, const char *fmt) 935 { 936 struct gendisk *hd; 937 938 if (check_pointer(&buf, end, bdev, spec)) 939 return buf; 940 941 hd = bdev->bd_disk; 942 buf = string(buf, end, hd->disk_name, spec); 943 if (bdev->bd_partno) { 944 if (isdigit(hd->disk_name[strlen(hd->disk_name)-1])) { 945 if (buf < end) 946 *buf = 'p'; 947 buf++; 948 } 949 buf = number(buf, end, bdev->bd_partno, spec); 950 } 951 return buf; 952 } 953 #endif 954 955 static noinline_for_stack 956 char *symbol_string(char *buf, char *end, void *ptr, 957 struct printf_spec spec, const char *fmt) 958 { 959 unsigned long value; 960 #ifdef CONFIG_KALLSYMS 961 char sym[KSYM_SYMBOL_LEN]; 962 #endif 963 964 if (fmt[1] == 'R') 965 ptr = __builtin_extract_return_addr(ptr); 966 value = (unsigned long)ptr; 967 968 #ifdef CONFIG_KALLSYMS 969 if (*fmt == 'B') 970 sprint_backtrace(sym, value); 971 else if (*fmt != 's') 972 sprint_symbol(sym, value); 973 else 974 sprint_symbol_no_offset(sym, value); 975 976 return string_nocheck(buf, end, sym, spec); 977 #else 978 return special_hex_number(buf, end, value, sizeof(void *)); 979 #endif 980 } 981 982 static const struct printf_spec default_str_spec = { 983 .field_width = -1, 984 .precision = -1, 985 }; 986 987 static const struct printf_spec default_flag_spec = { 988 .base = 16, 989 .precision = -1, 990 .flags = SPECIAL | SMALL, 991 }; 992 993 static const struct printf_spec default_dec_spec = { 994 .base = 10, 995 .precision = -1, 996 }; 997 998 static const struct printf_spec default_dec02_spec = { 999 .base = 10, 1000 .field_width = 2, 1001 .precision = -1, 1002 .flags = ZEROPAD, 1003 }; 1004 1005 static const struct printf_spec default_dec04_spec = { 1006 .base = 10, 1007 .field_width = 4, 1008 .precision = -1, 1009 .flags = ZEROPAD, 1010 }; 1011 1012 static noinline_for_stack 1013 char *resource_string(char *buf, char *end, struct resource *res, 1014 struct printf_spec spec, const char *fmt) 1015 { 1016 #ifndef IO_RSRC_PRINTK_SIZE 1017 #define IO_RSRC_PRINTK_SIZE 6 1018 #endif 1019 1020 #ifndef MEM_RSRC_PRINTK_SIZE 1021 #define MEM_RSRC_PRINTK_SIZE 10 1022 #endif 1023 static const struct printf_spec io_spec = { 1024 .base = 16, 1025 .field_width = IO_RSRC_PRINTK_SIZE, 1026 .precision = -1, 1027 .flags = SPECIAL | SMALL | ZEROPAD, 1028 }; 1029 static const struct printf_spec mem_spec = { 1030 .base = 16, 1031 .field_width = MEM_RSRC_PRINTK_SIZE, 1032 .precision = -1, 1033 .flags = SPECIAL | SMALL | ZEROPAD, 1034 }; 1035 static const struct printf_spec bus_spec = { 1036 .base = 16, 1037 .field_width = 2, 1038 .precision = -1, 1039 .flags = SMALL | ZEROPAD, 1040 }; 1041 static const struct printf_spec str_spec = { 1042 .field_width = -1, 1043 .precision = 10, 1044 .flags = LEFT, 1045 }; 1046 1047 /* 32-bit res (sizeof==4): 10 chars in dec, 10 in hex ("0x" + 8) 1048 * 64-bit res (sizeof==8): 20 chars in dec, 18 in hex ("0x" + 16) */ 1049 #define RSRC_BUF_SIZE ((2 * sizeof(resource_size_t)) + 4) 1050 #define FLAG_BUF_SIZE (2 * sizeof(res->flags)) 1051 #define DECODED_BUF_SIZE sizeof("[mem - 64bit pref window disabled]") 1052 #define RAW_BUF_SIZE sizeof("[mem - flags 0x]") 1053 char sym[max(2*RSRC_BUF_SIZE + DECODED_BUF_SIZE, 1054 2*RSRC_BUF_SIZE + FLAG_BUF_SIZE + RAW_BUF_SIZE)]; 1055 1056 char *p = sym, *pend = sym + sizeof(sym); 1057 int decode = (fmt[0] == 'R') ? 1 : 0; 1058 const struct printf_spec *specp; 1059 1060 if (check_pointer(&buf, end, res, spec)) 1061 return buf; 1062 1063 *p++ = '['; 1064 if (res->flags & IORESOURCE_IO) { 1065 p = string_nocheck(p, pend, "io ", str_spec); 1066 specp = &io_spec; 1067 } else if (res->flags & IORESOURCE_MEM) { 1068 p = string_nocheck(p, pend, "mem ", str_spec); 1069 specp = &mem_spec; 1070 } else if (res->flags & IORESOURCE_IRQ) { 1071 p = string_nocheck(p, pend, "irq ", str_spec); 1072 specp = &default_dec_spec; 1073 } else if (res->flags & IORESOURCE_DMA) { 1074 p = string_nocheck(p, pend, "dma ", str_spec); 1075 specp = &default_dec_spec; 1076 } else if (res->flags & IORESOURCE_BUS) { 1077 p = string_nocheck(p, pend, "bus ", str_spec); 1078 specp = &bus_spec; 1079 } else { 1080 p = string_nocheck(p, pend, "??? ", str_spec); 1081 specp = &mem_spec; 1082 decode = 0; 1083 } 1084 if (decode && res->flags & IORESOURCE_UNSET) { 1085 p = string_nocheck(p, pend, "size ", str_spec); 1086 p = number(p, pend, resource_size(res), *specp); 1087 } else { 1088 p = number(p, pend, res->start, *specp); 1089 if (res->start != res->end) { 1090 *p++ = '-'; 1091 p = number(p, pend, res->end, *specp); 1092 } 1093 } 1094 if (decode) { 1095 if (res->flags & IORESOURCE_MEM_64) 1096 p = string_nocheck(p, pend, " 64bit", str_spec); 1097 if (res->flags & IORESOURCE_PREFETCH) 1098 p = string_nocheck(p, pend, " pref", str_spec); 1099 if (res->flags & IORESOURCE_WINDOW) 1100 p = string_nocheck(p, pend, " window", str_spec); 1101 if (res->flags & IORESOURCE_DISABLED) 1102 p = string_nocheck(p, pend, " disabled", str_spec); 1103 } else { 1104 p = string_nocheck(p, pend, " flags ", str_spec); 1105 p = number(p, pend, res->flags, default_flag_spec); 1106 } 1107 *p++ = ']'; 1108 *p = '\0'; 1109 1110 return string_nocheck(buf, end, sym, spec); 1111 } 1112 1113 static noinline_for_stack 1114 char *hex_string(char *buf, char *end, u8 *addr, struct printf_spec spec, 1115 const char *fmt) 1116 { 1117 int i, len = 1; /* if we pass '%ph[CDN]', field width remains 1118 negative value, fallback to the default */ 1119 char separator; 1120 1121 if (spec.field_width == 0) 1122 /* nothing to print */ 1123 return buf; 1124 1125 if (check_pointer(&buf, end, addr, spec)) 1126 return buf; 1127 1128 switch (fmt[1]) { 1129 case 'C': 1130 separator = ':'; 1131 break; 1132 case 'D': 1133 separator = '-'; 1134 break; 1135 case 'N': 1136 separator = 0; 1137 break; 1138 default: 1139 separator = ' '; 1140 break; 1141 } 1142 1143 if (spec.field_width > 0) 1144 len = min_t(int, spec.field_width, 64); 1145 1146 for (i = 0; i < len; ++i) { 1147 if (buf < end) 1148 *buf = hex_asc_hi(addr[i]); 1149 ++buf; 1150 if (buf < end) 1151 *buf = hex_asc_lo(addr[i]); 1152 ++buf; 1153 1154 if (separator && i != len - 1) { 1155 if (buf < end) 1156 *buf = separator; 1157 ++buf; 1158 } 1159 } 1160 1161 return buf; 1162 } 1163 1164 static noinline_for_stack 1165 char *bitmap_string(char *buf, char *end, unsigned long *bitmap, 1166 struct printf_spec spec, const char *fmt) 1167 { 1168 const int CHUNKSZ = 32; 1169 int nr_bits = max_t(int, spec.field_width, 0); 1170 int i, chunksz; 1171 bool first = true; 1172 1173 if (check_pointer(&buf, end, bitmap, spec)) 1174 return buf; 1175 1176 /* reused to print numbers */ 1177 spec = (struct printf_spec){ .flags = SMALL | ZEROPAD, .base = 16 }; 1178 1179 chunksz = nr_bits & (CHUNKSZ - 1); 1180 if (chunksz == 0) 1181 chunksz = CHUNKSZ; 1182 1183 i = ALIGN(nr_bits, CHUNKSZ) - CHUNKSZ; 1184 for (; i >= 0; i -= CHUNKSZ) { 1185 u32 chunkmask, val; 1186 int word, bit; 1187 1188 chunkmask = ((1ULL << chunksz) - 1); 1189 word = i / BITS_PER_LONG; 1190 bit = i % BITS_PER_LONG; 1191 val = (bitmap[word] >> bit) & chunkmask; 1192 1193 if (!first) { 1194 if (buf < end) 1195 *buf = ','; 1196 buf++; 1197 } 1198 first = false; 1199 1200 spec.field_width = DIV_ROUND_UP(chunksz, 4); 1201 buf = number(buf, end, val, spec); 1202 1203 chunksz = CHUNKSZ; 1204 } 1205 return buf; 1206 } 1207 1208 static noinline_for_stack 1209 char *bitmap_list_string(char *buf, char *end, unsigned long *bitmap, 1210 struct printf_spec spec, const char *fmt) 1211 { 1212 int nr_bits = max_t(int, spec.field_width, 0); 1213 /* current bit is 'cur', most recently seen range is [rbot, rtop] */ 1214 int cur, rbot, rtop; 1215 bool first = true; 1216 1217 if (check_pointer(&buf, end, bitmap, spec)) 1218 return buf; 1219 1220 rbot = cur = find_first_bit(bitmap, nr_bits); 1221 while (cur < nr_bits) { 1222 rtop = cur; 1223 cur = find_next_bit(bitmap, nr_bits, cur + 1); 1224 if (cur < nr_bits && cur <= rtop + 1) 1225 continue; 1226 1227 if (!first) { 1228 if (buf < end) 1229 *buf = ','; 1230 buf++; 1231 } 1232 first = false; 1233 1234 buf = number(buf, end, rbot, default_dec_spec); 1235 if (rbot < rtop) { 1236 if (buf < end) 1237 *buf = '-'; 1238 buf++; 1239 1240 buf = number(buf, end, rtop, default_dec_spec); 1241 } 1242 1243 rbot = cur; 1244 } 1245 return buf; 1246 } 1247 1248 static noinline_for_stack 1249 char *mac_address_string(char *buf, char *end, u8 *addr, 1250 struct printf_spec spec, const char *fmt) 1251 { 1252 char mac_addr[sizeof("xx:xx:xx:xx:xx:xx")]; 1253 char *p = mac_addr; 1254 int i; 1255 char separator; 1256 bool reversed = false; 1257 1258 if (check_pointer(&buf, end, addr, spec)) 1259 return buf; 1260 1261 switch (fmt[1]) { 1262 case 'F': 1263 separator = '-'; 1264 break; 1265 1266 case 'R': 1267 reversed = true; 1268 fallthrough; 1269 1270 default: 1271 separator = ':'; 1272 break; 1273 } 1274 1275 for (i = 0; i < 6; i++) { 1276 if (reversed) 1277 p = hex_byte_pack(p, addr[5 - i]); 1278 else 1279 p = hex_byte_pack(p, addr[i]); 1280 1281 if (fmt[0] == 'M' && i != 5) 1282 *p++ = separator; 1283 } 1284 *p = '\0'; 1285 1286 return string_nocheck(buf, end, mac_addr, spec); 1287 } 1288 1289 static noinline_for_stack 1290 char *ip4_string(char *p, const u8 *addr, const char *fmt) 1291 { 1292 int i; 1293 bool leading_zeros = (fmt[0] == 'i'); 1294 int index; 1295 int step; 1296 1297 switch (fmt[2]) { 1298 case 'h': 1299 #ifdef __BIG_ENDIAN 1300 index = 0; 1301 step = 1; 1302 #else 1303 index = 3; 1304 step = -1; 1305 #endif 1306 break; 1307 case 'l': 1308 index = 3; 1309 step = -1; 1310 break; 1311 case 'n': 1312 case 'b': 1313 default: 1314 index = 0; 1315 step = 1; 1316 break; 1317 } 1318 for (i = 0; i < 4; i++) { 1319 char temp[4] __aligned(2); /* hold each IP quad in reverse order */ 1320 int digits = put_dec_trunc8(temp, addr[index]) - temp; 1321 if (leading_zeros) { 1322 if (digits < 3) 1323 *p++ = '0'; 1324 if (digits < 2) 1325 *p++ = '0'; 1326 } 1327 /* reverse the digits in the quad */ 1328 while (digits--) 1329 *p++ = temp[digits]; 1330 if (i < 3) 1331 *p++ = '.'; 1332 index += step; 1333 } 1334 *p = '\0'; 1335 1336 return p; 1337 } 1338 1339 static noinline_for_stack 1340 char *ip6_compressed_string(char *p, const char *addr) 1341 { 1342 int i, j, range; 1343 unsigned char zerolength[8]; 1344 int longest = 1; 1345 int colonpos = -1; 1346 u16 word; 1347 u8 hi, lo; 1348 bool needcolon = false; 1349 bool useIPv4; 1350 struct in6_addr in6; 1351 1352 memcpy(&in6, addr, sizeof(struct in6_addr)); 1353 1354 useIPv4 = ipv6_addr_v4mapped(&in6) || ipv6_addr_is_isatap(&in6); 1355 1356 memset(zerolength, 0, sizeof(zerolength)); 1357 1358 if (useIPv4) 1359 range = 6; 1360 else 1361 range = 8; 1362 1363 /* find position of longest 0 run */ 1364 for (i = 0; i < range; i++) { 1365 for (j = i; j < range; j++) { 1366 if (in6.s6_addr16[j] != 0) 1367 break; 1368 zerolength[i]++; 1369 } 1370 } 1371 for (i = 0; i < range; i++) { 1372 if (zerolength[i] > longest) { 1373 longest = zerolength[i]; 1374 colonpos = i; 1375 } 1376 } 1377 if (longest == 1) /* don't compress a single 0 */ 1378 colonpos = -1; 1379 1380 /* emit address */ 1381 for (i = 0; i < range; i++) { 1382 if (i == colonpos) { 1383 if (needcolon || i == 0) 1384 *p++ = ':'; 1385 *p++ = ':'; 1386 needcolon = false; 1387 i += longest - 1; 1388 continue; 1389 } 1390 if (needcolon) { 1391 *p++ = ':'; 1392 needcolon = false; 1393 } 1394 /* hex u16 without leading 0s */ 1395 word = ntohs(in6.s6_addr16[i]); 1396 hi = word >> 8; 1397 lo = word & 0xff; 1398 if (hi) { 1399 if (hi > 0x0f) 1400 p = hex_byte_pack(p, hi); 1401 else 1402 *p++ = hex_asc_lo(hi); 1403 p = hex_byte_pack(p, lo); 1404 } 1405 else if (lo > 0x0f) 1406 p = hex_byte_pack(p, lo); 1407 else 1408 *p++ = hex_asc_lo(lo); 1409 needcolon = true; 1410 } 1411 1412 if (useIPv4) { 1413 if (needcolon) 1414 *p++ = ':'; 1415 p = ip4_string(p, &in6.s6_addr[12], "I4"); 1416 } 1417 *p = '\0'; 1418 1419 return p; 1420 } 1421 1422 static noinline_for_stack 1423 char *ip6_string(char *p, const char *addr, const char *fmt) 1424 { 1425 int i; 1426 1427 for (i = 0; i < 8; i++) { 1428 p = hex_byte_pack(p, *addr++); 1429 p = hex_byte_pack(p, *addr++); 1430 if (fmt[0] == 'I' && i != 7) 1431 *p++ = ':'; 1432 } 1433 *p = '\0'; 1434 1435 return p; 1436 } 1437 1438 static noinline_for_stack 1439 char *ip6_addr_string(char *buf, char *end, const u8 *addr, 1440 struct printf_spec spec, const char *fmt) 1441 { 1442 char ip6_addr[sizeof("xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255")]; 1443 1444 if (fmt[0] == 'I' && fmt[2] == 'c') 1445 ip6_compressed_string(ip6_addr, addr); 1446 else 1447 ip6_string(ip6_addr, addr, fmt); 1448 1449 return string_nocheck(buf, end, ip6_addr, spec); 1450 } 1451 1452 static noinline_for_stack 1453 char *ip4_addr_string(char *buf, char *end, const u8 *addr, 1454 struct printf_spec spec, const char *fmt) 1455 { 1456 char ip4_addr[sizeof("255.255.255.255")]; 1457 1458 ip4_string(ip4_addr, addr, fmt); 1459 1460 return string_nocheck(buf, end, ip4_addr, spec); 1461 } 1462 1463 static noinline_for_stack 1464 char *ip6_addr_string_sa(char *buf, char *end, const struct sockaddr_in6 *sa, 1465 struct printf_spec spec, const char *fmt) 1466 { 1467 bool have_p = false, have_s = false, have_f = false, have_c = false; 1468 char ip6_addr[sizeof("[xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255]") + 1469 sizeof(":12345") + sizeof("/123456789") + 1470 sizeof("%1234567890")]; 1471 char *p = ip6_addr, *pend = ip6_addr + sizeof(ip6_addr); 1472 const u8 *addr = (const u8 *) &sa->sin6_addr; 1473 char fmt6[2] = { fmt[0], '6' }; 1474 u8 off = 0; 1475 1476 fmt++; 1477 while (isalpha(*++fmt)) { 1478 switch (*fmt) { 1479 case 'p': 1480 have_p = true; 1481 break; 1482 case 'f': 1483 have_f = true; 1484 break; 1485 case 's': 1486 have_s = true; 1487 break; 1488 case 'c': 1489 have_c = true; 1490 break; 1491 } 1492 } 1493 1494 if (have_p || have_s || have_f) { 1495 *p = '['; 1496 off = 1; 1497 } 1498 1499 if (fmt6[0] == 'I' && have_c) 1500 p = ip6_compressed_string(ip6_addr + off, addr); 1501 else 1502 p = ip6_string(ip6_addr + off, addr, fmt6); 1503 1504 if (have_p || have_s || have_f) 1505 *p++ = ']'; 1506 1507 if (have_p) { 1508 *p++ = ':'; 1509 p = number(p, pend, ntohs(sa->sin6_port), spec); 1510 } 1511 if (have_f) { 1512 *p++ = '/'; 1513 p = number(p, pend, ntohl(sa->sin6_flowinfo & 1514 IPV6_FLOWINFO_MASK), spec); 1515 } 1516 if (have_s) { 1517 *p++ = '%'; 1518 p = number(p, pend, sa->sin6_scope_id, spec); 1519 } 1520 *p = '\0'; 1521 1522 return string_nocheck(buf, end, ip6_addr, spec); 1523 } 1524 1525 static noinline_for_stack 1526 char *ip4_addr_string_sa(char *buf, char *end, const struct sockaddr_in *sa, 1527 struct printf_spec spec, const char *fmt) 1528 { 1529 bool have_p = false; 1530 char *p, ip4_addr[sizeof("255.255.255.255") + sizeof(":12345")]; 1531 char *pend = ip4_addr + sizeof(ip4_addr); 1532 const u8 *addr = (const u8 *) &sa->sin_addr.s_addr; 1533 char fmt4[3] = { fmt[0], '4', 0 }; 1534 1535 fmt++; 1536 while (isalpha(*++fmt)) { 1537 switch (*fmt) { 1538 case 'p': 1539 have_p = true; 1540 break; 1541 case 'h': 1542 case 'l': 1543 case 'n': 1544 case 'b': 1545 fmt4[2] = *fmt; 1546 break; 1547 } 1548 } 1549 1550 p = ip4_string(ip4_addr, addr, fmt4); 1551 if (have_p) { 1552 *p++ = ':'; 1553 p = number(p, pend, ntohs(sa->sin_port), spec); 1554 } 1555 *p = '\0'; 1556 1557 return string_nocheck(buf, end, ip4_addr, spec); 1558 } 1559 1560 static noinline_for_stack 1561 char *ip_addr_string(char *buf, char *end, const void *ptr, 1562 struct printf_spec spec, const char *fmt) 1563 { 1564 char *err_fmt_msg; 1565 1566 if (check_pointer(&buf, end, ptr, spec)) 1567 return buf; 1568 1569 switch (fmt[1]) { 1570 case '6': 1571 return ip6_addr_string(buf, end, ptr, spec, fmt); 1572 case '4': 1573 return ip4_addr_string(buf, end, ptr, spec, fmt); 1574 case 'S': { 1575 const union { 1576 struct sockaddr raw; 1577 struct sockaddr_in v4; 1578 struct sockaddr_in6 v6; 1579 } *sa = ptr; 1580 1581 switch (sa->raw.sa_family) { 1582 case AF_INET: 1583 return ip4_addr_string_sa(buf, end, &sa->v4, spec, fmt); 1584 case AF_INET6: 1585 return ip6_addr_string_sa(buf, end, &sa->v6, spec, fmt); 1586 default: 1587 return error_string(buf, end, "(einval)", spec); 1588 }} 1589 } 1590 1591 err_fmt_msg = fmt[0] == 'i' ? "(%pi?)" : "(%pI?)"; 1592 return error_string(buf, end, err_fmt_msg, spec); 1593 } 1594 1595 static noinline_for_stack 1596 char *escaped_string(char *buf, char *end, u8 *addr, struct printf_spec spec, 1597 const char *fmt) 1598 { 1599 bool found = true; 1600 int count = 1; 1601 unsigned int flags = 0; 1602 int len; 1603 1604 if (spec.field_width == 0) 1605 return buf; /* nothing to print */ 1606 1607 if (check_pointer(&buf, end, addr, spec)) 1608 return buf; 1609 1610 do { 1611 switch (fmt[count++]) { 1612 case 'a': 1613 flags |= ESCAPE_ANY; 1614 break; 1615 case 'c': 1616 flags |= ESCAPE_SPECIAL; 1617 break; 1618 case 'h': 1619 flags |= ESCAPE_HEX; 1620 break; 1621 case 'n': 1622 flags |= ESCAPE_NULL; 1623 break; 1624 case 'o': 1625 flags |= ESCAPE_OCTAL; 1626 break; 1627 case 'p': 1628 flags |= ESCAPE_NP; 1629 break; 1630 case 's': 1631 flags |= ESCAPE_SPACE; 1632 break; 1633 default: 1634 found = false; 1635 break; 1636 } 1637 } while (found); 1638 1639 if (!flags) 1640 flags = ESCAPE_ANY_NP; 1641 1642 len = spec.field_width < 0 ? 1 : spec.field_width; 1643 1644 /* 1645 * string_escape_mem() writes as many characters as it can to 1646 * the given buffer, and returns the total size of the output 1647 * had the buffer been big enough. 1648 */ 1649 buf += string_escape_mem(addr, len, buf, buf < end ? end - buf : 0, flags, NULL); 1650 1651 return buf; 1652 } 1653 1654 static char *va_format(char *buf, char *end, struct va_format *va_fmt, 1655 struct printf_spec spec, const char *fmt) 1656 { 1657 va_list va; 1658 1659 if (check_pointer(&buf, end, va_fmt, spec)) 1660 return buf; 1661 1662 va_copy(va, *va_fmt->va); 1663 buf += vsnprintf(buf, end > buf ? end - buf : 0, va_fmt->fmt, va); 1664 va_end(va); 1665 1666 return buf; 1667 } 1668 1669 static noinline_for_stack 1670 char *uuid_string(char *buf, char *end, const u8 *addr, 1671 struct printf_spec spec, const char *fmt) 1672 { 1673 char uuid[UUID_STRING_LEN + 1]; 1674 char *p = uuid; 1675 int i; 1676 const u8 *index = uuid_index; 1677 bool uc = false; 1678 1679 if (check_pointer(&buf, end, addr, spec)) 1680 return buf; 1681 1682 switch (*(++fmt)) { 1683 case 'L': 1684 uc = true; 1685 fallthrough; 1686 case 'l': 1687 index = guid_index; 1688 break; 1689 case 'B': 1690 uc = true; 1691 break; 1692 } 1693 1694 for (i = 0; i < 16; i++) { 1695 if (uc) 1696 p = hex_byte_pack_upper(p, addr[index[i]]); 1697 else 1698 p = hex_byte_pack(p, addr[index[i]]); 1699 switch (i) { 1700 case 3: 1701 case 5: 1702 case 7: 1703 case 9: 1704 *p++ = '-'; 1705 break; 1706 } 1707 } 1708 1709 *p = 0; 1710 1711 return string_nocheck(buf, end, uuid, spec); 1712 } 1713 1714 static noinline_for_stack 1715 char *netdev_bits(char *buf, char *end, const void *addr, 1716 struct printf_spec spec, const char *fmt) 1717 { 1718 unsigned long long num; 1719 int size; 1720 1721 if (check_pointer(&buf, end, addr, spec)) 1722 return buf; 1723 1724 switch (fmt[1]) { 1725 case 'F': 1726 num = *(const netdev_features_t *)addr; 1727 size = sizeof(netdev_features_t); 1728 break; 1729 default: 1730 return error_string(buf, end, "(%pN?)", spec); 1731 } 1732 1733 return special_hex_number(buf, end, num, size); 1734 } 1735 1736 static noinline_for_stack 1737 char *address_val(char *buf, char *end, const void *addr, 1738 struct printf_spec spec, const char *fmt) 1739 { 1740 unsigned long long num; 1741 int size; 1742 1743 if (check_pointer(&buf, end, addr, spec)) 1744 return buf; 1745 1746 switch (fmt[1]) { 1747 case 'd': 1748 num = *(const dma_addr_t *)addr; 1749 size = sizeof(dma_addr_t); 1750 break; 1751 case 'p': 1752 default: 1753 num = *(const phys_addr_t *)addr; 1754 size = sizeof(phys_addr_t); 1755 break; 1756 } 1757 1758 return special_hex_number(buf, end, num, size); 1759 } 1760 1761 static noinline_for_stack 1762 char *date_str(char *buf, char *end, const struct rtc_time *tm, bool r) 1763 { 1764 int year = tm->tm_year + (r ? 0 : 1900); 1765 int mon = tm->tm_mon + (r ? 0 : 1); 1766 1767 buf = number(buf, end, year, default_dec04_spec); 1768 if (buf < end) 1769 *buf = '-'; 1770 buf++; 1771 1772 buf = number(buf, end, mon, default_dec02_spec); 1773 if (buf < end) 1774 *buf = '-'; 1775 buf++; 1776 1777 return number(buf, end, tm->tm_mday, default_dec02_spec); 1778 } 1779 1780 static noinline_for_stack 1781 char *time_str(char *buf, char *end, const struct rtc_time *tm, bool r) 1782 { 1783 buf = number(buf, end, tm->tm_hour, default_dec02_spec); 1784 if (buf < end) 1785 *buf = ':'; 1786 buf++; 1787 1788 buf = number(buf, end, tm->tm_min, default_dec02_spec); 1789 if (buf < end) 1790 *buf = ':'; 1791 buf++; 1792 1793 return number(buf, end, tm->tm_sec, default_dec02_spec); 1794 } 1795 1796 static noinline_for_stack 1797 char *rtc_str(char *buf, char *end, const struct rtc_time *tm, 1798 struct printf_spec spec, const char *fmt) 1799 { 1800 bool have_t = true, have_d = true; 1801 bool raw = false; 1802 int count = 2; 1803 1804 if (check_pointer(&buf, end, tm, spec)) 1805 return buf; 1806 1807 switch (fmt[count]) { 1808 case 'd': 1809 have_t = false; 1810 count++; 1811 break; 1812 case 't': 1813 have_d = false; 1814 count++; 1815 break; 1816 } 1817 1818 raw = fmt[count] == 'r'; 1819 1820 if (have_d) 1821 buf = date_str(buf, end, tm, raw); 1822 if (have_d && have_t) { 1823 /* Respect ISO 8601 */ 1824 if (buf < end) 1825 *buf = 'T'; 1826 buf++; 1827 } 1828 if (have_t) 1829 buf = time_str(buf, end, tm, raw); 1830 1831 return buf; 1832 } 1833 1834 static noinline_for_stack 1835 char *time64_str(char *buf, char *end, const time64_t time, 1836 struct printf_spec spec, const char *fmt) 1837 { 1838 struct rtc_time rtc_time; 1839 struct tm tm; 1840 1841 time64_to_tm(time, 0, &tm); 1842 1843 rtc_time.tm_sec = tm.tm_sec; 1844 rtc_time.tm_min = tm.tm_min; 1845 rtc_time.tm_hour = tm.tm_hour; 1846 rtc_time.tm_mday = tm.tm_mday; 1847 rtc_time.tm_mon = tm.tm_mon; 1848 rtc_time.tm_year = tm.tm_year; 1849 rtc_time.tm_wday = tm.tm_wday; 1850 rtc_time.tm_yday = tm.tm_yday; 1851 1852 rtc_time.tm_isdst = 0; 1853 1854 return rtc_str(buf, end, &rtc_time, spec, fmt); 1855 } 1856 1857 static noinline_for_stack 1858 char *time_and_date(char *buf, char *end, void *ptr, struct printf_spec spec, 1859 const char *fmt) 1860 { 1861 switch (fmt[1]) { 1862 case 'R': 1863 return rtc_str(buf, end, (const struct rtc_time *)ptr, spec, fmt); 1864 case 'T': 1865 return time64_str(buf, end, *(const time64_t *)ptr, spec, fmt); 1866 default: 1867 return error_string(buf, end, "(%pt?)", spec); 1868 } 1869 } 1870 1871 static noinline_for_stack 1872 char *clock(char *buf, char *end, struct clk *clk, struct printf_spec spec, 1873 const char *fmt) 1874 { 1875 if (!IS_ENABLED(CONFIG_HAVE_CLK)) 1876 return error_string(buf, end, "(%pC?)", spec); 1877 1878 if (check_pointer(&buf, end, clk, spec)) 1879 return buf; 1880 1881 switch (fmt[1]) { 1882 case 'n': 1883 default: 1884 #ifdef CONFIG_COMMON_CLK 1885 return string(buf, end, __clk_get_name(clk), spec); 1886 #else 1887 return ptr_to_id(buf, end, clk, spec); 1888 #endif 1889 } 1890 } 1891 1892 static 1893 char *format_flags(char *buf, char *end, unsigned long flags, 1894 const struct trace_print_flags *names) 1895 { 1896 unsigned long mask; 1897 1898 for ( ; flags && names->name; names++) { 1899 mask = names->mask; 1900 if ((flags & mask) != mask) 1901 continue; 1902 1903 buf = string(buf, end, names->name, default_str_spec); 1904 1905 flags &= ~mask; 1906 if (flags) { 1907 if (buf < end) 1908 *buf = '|'; 1909 buf++; 1910 } 1911 } 1912 1913 if (flags) 1914 buf = number(buf, end, flags, default_flag_spec); 1915 1916 return buf; 1917 } 1918 1919 static noinline_for_stack 1920 char *flags_string(char *buf, char *end, void *flags_ptr, 1921 struct printf_spec spec, const char *fmt) 1922 { 1923 unsigned long flags; 1924 const struct trace_print_flags *names; 1925 1926 if (check_pointer(&buf, end, flags_ptr, spec)) 1927 return buf; 1928 1929 switch (fmt[1]) { 1930 case 'p': 1931 flags = *(unsigned long *)flags_ptr; 1932 /* Remove zone id */ 1933 flags &= (1UL << NR_PAGEFLAGS) - 1; 1934 names = pageflag_names; 1935 break; 1936 case 'v': 1937 flags = *(unsigned long *)flags_ptr; 1938 names = vmaflag_names; 1939 break; 1940 case 'g': 1941 flags = (__force unsigned long)(*(gfp_t *)flags_ptr); 1942 names = gfpflag_names; 1943 break; 1944 default: 1945 return error_string(buf, end, "(%pG?)", spec); 1946 } 1947 1948 return format_flags(buf, end, flags, names); 1949 } 1950 1951 static noinline_for_stack 1952 char *fwnode_full_name_string(struct fwnode_handle *fwnode, char *buf, 1953 char *end) 1954 { 1955 int depth; 1956 1957 /* Loop starting from the root node to the current node. */ 1958 for (depth = fwnode_count_parents(fwnode); depth >= 0; depth--) { 1959 struct fwnode_handle *__fwnode = 1960 fwnode_get_nth_parent(fwnode, depth); 1961 1962 buf = string(buf, end, fwnode_get_name_prefix(__fwnode), 1963 default_str_spec); 1964 buf = string(buf, end, fwnode_get_name(__fwnode), 1965 default_str_spec); 1966 1967 fwnode_handle_put(__fwnode); 1968 } 1969 1970 return buf; 1971 } 1972 1973 static noinline_for_stack 1974 char *device_node_string(char *buf, char *end, struct device_node *dn, 1975 struct printf_spec spec, const char *fmt) 1976 { 1977 char tbuf[sizeof("xxxx") + 1]; 1978 const char *p; 1979 int ret; 1980 char *buf_start = buf; 1981 struct property *prop; 1982 bool has_mult, pass; 1983 1984 struct printf_spec str_spec = spec; 1985 str_spec.field_width = -1; 1986 1987 if (fmt[0] != 'F') 1988 return error_string(buf, end, "(%pO?)", spec); 1989 1990 if (!IS_ENABLED(CONFIG_OF)) 1991 return error_string(buf, end, "(%pOF?)", spec); 1992 1993 if (check_pointer(&buf, end, dn, spec)) 1994 return buf; 1995 1996 /* simple case without anything any more format specifiers */ 1997 fmt++; 1998 if (fmt[0] == '\0' || strcspn(fmt,"fnpPFcC") > 0) 1999 fmt = "f"; 2000 2001 for (pass = false; strspn(fmt,"fnpPFcC"); fmt++, pass = true) { 2002 int precision; 2003 if (pass) { 2004 if (buf < end) 2005 *buf = ':'; 2006 buf++; 2007 } 2008 2009 switch (*fmt) { 2010 case 'f': /* full_name */ 2011 buf = fwnode_full_name_string(of_fwnode_handle(dn), buf, 2012 end); 2013 break; 2014 case 'n': /* name */ 2015 p = fwnode_get_name(of_fwnode_handle(dn)); 2016 precision = str_spec.precision; 2017 str_spec.precision = strchrnul(p, '@') - p; 2018 buf = string(buf, end, p, str_spec); 2019 str_spec.precision = precision; 2020 break; 2021 case 'p': /* phandle */ 2022 buf = number(buf, end, (unsigned int)dn->phandle, default_dec_spec); 2023 break; 2024 case 'P': /* path-spec */ 2025 p = fwnode_get_name(of_fwnode_handle(dn)); 2026 if (!p[1]) 2027 p = "/"; 2028 buf = string(buf, end, p, str_spec); 2029 break; 2030 case 'F': /* flags */ 2031 tbuf[0] = of_node_check_flag(dn, OF_DYNAMIC) ? 'D' : '-'; 2032 tbuf[1] = of_node_check_flag(dn, OF_DETACHED) ? 'd' : '-'; 2033 tbuf[2] = of_node_check_flag(dn, OF_POPULATED) ? 'P' : '-'; 2034 tbuf[3] = of_node_check_flag(dn, OF_POPULATED_BUS) ? 'B' : '-'; 2035 tbuf[4] = 0; 2036 buf = string_nocheck(buf, end, tbuf, str_spec); 2037 break; 2038 case 'c': /* major compatible string */ 2039 ret = of_property_read_string(dn, "compatible", &p); 2040 if (!ret) 2041 buf = string(buf, end, p, str_spec); 2042 break; 2043 case 'C': /* full compatible string */ 2044 has_mult = false; 2045 of_property_for_each_string(dn, "compatible", prop, p) { 2046 if (has_mult) 2047 buf = string_nocheck(buf, end, ",", str_spec); 2048 buf = string_nocheck(buf, end, "\"", str_spec); 2049 buf = string(buf, end, p, str_spec); 2050 buf = string_nocheck(buf, end, "\"", str_spec); 2051 2052 has_mult = true; 2053 } 2054 break; 2055 default: 2056 break; 2057 } 2058 } 2059 2060 return widen_string(buf, buf - buf_start, end, spec); 2061 } 2062 2063 static noinline_for_stack 2064 char *fwnode_string(char *buf, char *end, struct fwnode_handle *fwnode, 2065 struct printf_spec spec, const char *fmt) 2066 { 2067 struct printf_spec str_spec = spec; 2068 char *buf_start = buf; 2069 2070 str_spec.field_width = -1; 2071 2072 if (*fmt != 'w') 2073 return error_string(buf, end, "(%pf?)", spec); 2074 2075 if (check_pointer(&buf, end, fwnode, spec)) 2076 return buf; 2077 2078 fmt++; 2079 2080 switch (*fmt) { 2081 case 'P': /* name */ 2082 buf = string(buf, end, fwnode_get_name(fwnode), str_spec); 2083 break; 2084 case 'f': /* full_name */ 2085 default: 2086 buf = fwnode_full_name_string(fwnode, buf, end); 2087 break; 2088 } 2089 2090 return widen_string(buf, buf - buf_start, end, spec); 2091 } 2092 2093 /* Disable pointer hashing if requested */ 2094 bool no_hash_pointers __ro_after_init; 2095 EXPORT_SYMBOL_GPL(no_hash_pointers); 2096 2097 static int __init no_hash_pointers_enable(char *str) 2098 { 2099 no_hash_pointers = true; 2100 2101 pr_warn("**********************************************************\n"); 2102 pr_warn("** NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE **\n"); 2103 pr_warn("** **\n"); 2104 pr_warn("** This system shows unhashed kernel memory addresses **\n"); 2105 pr_warn("** via the console, logs, and other interfaces. This **\n"); 2106 pr_warn("** might reduce the security of your system. **\n"); 2107 pr_warn("** **\n"); 2108 pr_warn("** If you see this message and you are not debugging **\n"); 2109 pr_warn("** the kernel, report this immediately to your system **\n"); 2110 pr_warn("** administrator! **\n"); 2111 pr_warn("** **\n"); 2112 pr_warn("** NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE **\n"); 2113 pr_warn("**********************************************************\n"); 2114 2115 return 0; 2116 } 2117 early_param("no_hash_pointers", no_hash_pointers_enable); 2118 2119 /* 2120 * Show a '%p' thing. A kernel extension is that the '%p' is followed 2121 * by an extra set of alphanumeric characters that are extended format 2122 * specifiers. 2123 * 2124 * Please update scripts/checkpatch.pl when adding/removing conversion 2125 * characters. (Search for "check for vsprintf extension"). 2126 * 2127 * Right now we handle: 2128 * 2129 * - 'S' For symbolic direct pointers (or function descriptors) with offset 2130 * - 's' For symbolic direct pointers (or function descriptors) without offset 2131 * - '[Ss]R' as above with __builtin_extract_return_addr() translation 2132 * - '[Ff]' %pf and %pF were obsoleted and later removed in favor of 2133 * %ps and %pS. Be careful when re-using these specifiers. 2134 * - 'B' For backtraced symbolic direct pointers with offset 2135 * - 'R' For decoded struct resource, e.g., [mem 0x0-0x1f 64bit pref] 2136 * - 'r' For raw struct resource, e.g., [mem 0x0-0x1f flags 0x201] 2137 * - 'b[l]' For a bitmap, the number of bits is determined by the field 2138 * width which must be explicitly specified either as part of the 2139 * format string '%32b[l]' or through '%*b[l]', [l] selects 2140 * range-list format instead of hex format 2141 * - 'M' For a 6-byte MAC address, it prints the address in the 2142 * usual colon-separated hex notation 2143 * - 'm' For a 6-byte MAC address, it prints the hex address without colons 2144 * - 'MF' For a 6-byte MAC FDDI address, it prints the address 2145 * with a dash-separated hex notation 2146 * - '[mM]R' For a 6-byte MAC address, Reverse order (Bluetooth) 2147 * - 'I' [46] for IPv4/IPv6 addresses printed in the usual way 2148 * IPv4 uses dot-separated decimal without leading 0's (1.2.3.4) 2149 * IPv6 uses colon separated network-order 16 bit hex with leading 0's 2150 * [S][pfs] 2151 * Generic IPv4/IPv6 address (struct sockaddr *) that falls back to 2152 * [4] or [6] and is able to print port [p], flowinfo [f], scope [s] 2153 * - 'i' [46] for 'raw' IPv4/IPv6 addresses 2154 * IPv6 omits the colons (01020304...0f) 2155 * IPv4 uses dot-separated decimal with leading 0's (010.123.045.006) 2156 * [S][pfs] 2157 * Generic IPv4/IPv6 address (struct sockaddr *) that falls back to 2158 * [4] or [6] and is able to print port [p], flowinfo [f], scope [s] 2159 * - '[Ii][4S][hnbl]' IPv4 addresses in host, network, big or little endian order 2160 * - 'I[6S]c' for IPv6 addresses printed as specified by 2161 * https://tools.ietf.org/html/rfc5952 2162 * - 'E[achnops]' For an escaped buffer, where rules are defined by combination 2163 * of the following flags (see string_escape_mem() for the 2164 * details): 2165 * a - ESCAPE_ANY 2166 * c - ESCAPE_SPECIAL 2167 * h - ESCAPE_HEX 2168 * n - ESCAPE_NULL 2169 * o - ESCAPE_OCTAL 2170 * p - ESCAPE_NP 2171 * s - ESCAPE_SPACE 2172 * By default ESCAPE_ANY_NP is used. 2173 * - 'U' For a 16 byte UUID/GUID, it prints the UUID/GUID in the form 2174 * "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx" 2175 * Options for %pU are: 2176 * b big endian lower case hex (default) 2177 * B big endian UPPER case hex 2178 * l little endian lower case hex 2179 * L little endian UPPER case hex 2180 * big endian output byte order is: 2181 * [0][1][2][3]-[4][5]-[6][7]-[8][9]-[10][11][12][13][14][15] 2182 * little endian output byte order is: 2183 * [3][2][1][0]-[5][4]-[7][6]-[8][9]-[10][11][12][13][14][15] 2184 * - 'V' For a struct va_format which contains a format string * and va_list *, 2185 * call vsnprintf(->format, *->va_list). 2186 * Implements a "recursive vsnprintf". 2187 * Do not use this feature without some mechanism to verify the 2188 * correctness of the format string and va_list arguments. 2189 * - 'K' For a kernel pointer that should be hidden from unprivileged users 2190 * - 'NF' For a netdev_features_t 2191 * - 'h[CDN]' For a variable-length buffer, it prints it as a hex string with 2192 * a certain separator (' ' by default): 2193 * C colon 2194 * D dash 2195 * N no separator 2196 * The maximum supported length is 64 bytes of the input. Consider 2197 * to use print_hex_dump() for the larger input. 2198 * - 'a[pd]' For address types [p] phys_addr_t, [d] dma_addr_t and derivatives 2199 * (default assumed to be phys_addr_t, passed by reference) 2200 * - 'd[234]' For a dentry name (optionally 2-4 last components) 2201 * - 'D[234]' Same as 'd' but for a struct file 2202 * - 'g' For block_device name (gendisk + partition number) 2203 * - 't[RT][dt][r]' For time and date as represented by: 2204 * R struct rtc_time 2205 * T time64_t 2206 * - 'C' For a clock, it prints the name (Common Clock Framework) or address 2207 * (legacy clock framework) of the clock 2208 * - 'Cn' For a clock, it prints the name (Common Clock Framework) or address 2209 * (legacy clock framework) of the clock 2210 * - 'G' For flags to be printed as a collection of symbolic strings that would 2211 * construct the specific value. Supported flags given by option: 2212 * p page flags (see struct page) given as pointer to unsigned long 2213 * g gfp flags (GFP_* and __GFP_*) given as pointer to gfp_t 2214 * v vma flags (VM_*) given as pointer to unsigned long 2215 * - 'OF[fnpPcCF]' For a device tree object 2216 * Without any optional arguments prints the full_name 2217 * f device node full_name 2218 * n device node name 2219 * p device node phandle 2220 * P device node path spec (name + @unit) 2221 * F device node flags 2222 * c major compatible string 2223 * C full compatible string 2224 * - 'fw[fP]' For a firmware node (struct fwnode_handle) pointer 2225 * Without an option prints the full name of the node 2226 * f full name 2227 * P node name, including a possible unit address 2228 * - 'x' For printing the address. Equivalent to "%lx". 2229 * - '[ku]s' For a BPF/tracing related format specifier, e.g. used out of 2230 * bpf_trace_printk() where [ku] prefix specifies either kernel (k) 2231 * or user (u) memory to probe, and: 2232 * s a string, equivalent to "%s" on direct vsnprintf() use 2233 * 2234 * ** When making changes please also update: 2235 * Documentation/core-api/printk-formats.rst 2236 * 2237 * Note: The default behaviour (unadorned %p) is to hash the address, 2238 * rendering it useful as a unique identifier. 2239 */ 2240 static noinline_for_stack 2241 char *pointer(const char *fmt, char *buf, char *end, void *ptr, 2242 struct printf_spec spec) 2243 { 2244 switch (*fmt) { 2245 case 'S': 2246 case 's': 2247 ptr = dereference_symbol_descriptor(ptr); 2248 fallthrough; 2249 case 'B': 2250 return symbol_string(buf, end, ptr, spec, fmt); 2251 case 'R': 2252 case 'r': 2253 return resource_string(buf, end, ptr, spec, fmt); 2254 case 'h': 2255 return hex_string(buf, end, ptr, spec, fmt); 2256 case 'b': 2257 switch (fmt[1]) { 2258 case 'l': 2259 return bitmap_list_string(buf, end, ptr, spec, fmt); 2260 default: 2261 return bitmap_string(buf, end, ptr, spec, fmt); 2262 } 2263 case 'M': /* Colon separated: 00:01:02:03:04:05 */ 2264 case 'm': /* Contiguous: 000102030405 */ 2265 /* [mM]F (FDDI) */ 2266 /* [mM]R (Reverse order; Bluetooth) */ 2267 return mac_address_string(buf, end, ptr, spec, fmt); 2268 case 'I': /* Formatted IP supported 2269 * 4: 1.2.3.4 2270 * 6: 0001:0203:...:0708 2271 * 6c: 1::708 or 1::1.2.3.4 2272 */ 2273 case 'i': /* Contiguous: 2274 * 4: 001.002.003.004 2275 * 6: 000102...0f 2276 */ 2277 return ip_addr_string(buf, end, ptr, spec, fmt); 2278 case 'E': 2279 return escaped_string(buf, end, ptr, spec, fmt); 2280 case 'U': 2281 return uuid_string(buf, end, ptr, spec, fmt); 2282 case 'V': 2283 return va_format(buf, end, ptr, spec, fmt); 2284 case 'K': 2285 return restricted_pointer(buf, end, ptr, spec); 2286 case 'N': 2287 return netdev_bits(buf, end, ptr, spec, fmt); 2288 case 'a': 2289 return address_val(buf, end, ptr, spec, fmt); 2290 case 'd': 2291 return dentry_name(buf, end, ptr, spec, fmt); 2292 case 't': 2293 return time_and_date(buf, end, ptr, spec, fmt); 2294 case 'C': 2295 return clock(buf, end, ptr, spec, fmt); 2296 case 'D': 2297 return file_dentry_name(buf, end, ptr, spec, fmt); 2298 #ifdef CONFIG_BLOCK 2299 case 'g': 2300 return bdev_name(buf, end, ptr, spec, fmt); 2301 #endif 2302 2303 case 'G': 2304 return flags_string(buf, end, ptr, spec, fmt); 2305 case 'O': 2306 return device_node_string(buf, end, ptr, spec, fmt + 1); 2307 case 'f': 2308 return fwnode_string(buf, end, ptr, spec, fmt + 1); 2309 case 'x': 2310 return pointer_string(buf, end, ptr, spec); 2311 case 'e': 2312 /* %pe with a non-ERR_PTR gets treated as plain %p */ 2313 if (!IS_ERR(ptr)) 2314 break; 2315 return err_ptr(buf, end, ptr, spec); 2316 case 'u': 2317 case 'k': 2318 switch (fmt[1]) { 2319 case 's': 2320 return string(buf, end, ptr, spec); 2321 default: 2322 return error_string(buf, end, "(einval)", spec); 2323 } 2324 } 2325 2326 /* 2327 * default is to _not_ leak addresses, so hash before printing, 2328 * unless no_hash_pointers is specified on the command line. 2329 */ 2330 if (unlikely(no_hash_pointers)) 2331 return pointer_string(buf, end, ptr, spec); 2332 else 2333 return ptr_to_id(buf, end, ptr, spec); 2334 } 2335 2336 /* 2337 * Helper function to decode printf style format. 2338 * Each call decode a token from the format and return the 2339 * number of characters read (or likely the delta where it wants 2340 * to go on the next call). 2341 * The decoded token is returned through the parameters 2342 * 2343 * 'h', 'l', or 'L' for integer fields 2344 * 'z' support added 23/7/1999 S.H. 2345 * 'z' changed to 'Z' --davidm 1/25/99 2346 * 'Z' changed to 'z' --adobriyan 2017-01-25 2347 * 't' added for ptrdiff_t 2348 * 2349 * @fmt: the format string 2350 * @type of the token returned 2351 * @flags: various flags such as +, -, # tokens.. 2352 * @field_width: overwritten width 2353 * @base: base of the number (octal, hex, ...) 2354 * @precision: precision of a number 2355 * @qualifier: qualifier of a number (long, size_t, ...) 2356 */ 2357 static noinline_for_stack 2358 int format_decode(const char *fmt, struct printf_spec *spec) 2359 { 2360 const char *start = fmt; 2361 char qualifier; 2362 2363 /* we finished early by reading the field width */ 2364 if (spec->type == FORMAT_TYPE_WIDTH) { 2365 if (spec->field_width < 0) { 2366 spec->field_width = -spec->field_width; 2367 spec->flags |= LEFT; 2368 } 2369 spec->type = FORMAT_TYPE_NONE; 2370 goto precision; 2371 } 2372 2373 /* we finished early by reading the precision */ 2374 if (spec->type == FORMAT_TYPE_PRECISION) { 2375 if (spec->precision < 0) 2376 spec->precision = 0; 2377 2378 spec->type = FORMAT_TYPE_NONE; 2379 goto qualifier; 2380 } 2381 2382 /* By default */ 2383 spec->type = FORMAT_TYPE_NONE; 2384 2385 for (; *fmt ; ++fmt) { 2386 if (*fmt == '%') 2387 break; 2388 } 2389 2390 /* Return the current non-format string */ 2391 if (fmt != start || !*fmt) 2392 return fmt - start; 2393 2394 /* Process flags */ 2395 spec->flags = 0; 2396 2397 while (1) { /* this also skips first '%' */ 2398 bool found = true; 2399 2400 ++fmt; 2401 2402 switch (*fmt) { 2403 case '-': spec->flags |= LEFT; break; 2404 case '+': spec->flags |= PLUS; break; 2405 case ' ': spec->flags |= SPACE; break; 2406 case '#': spec->flags |= SPECIAL; break; 2407 case '0': spec->flags |= ZEROPAD; break; 2408 default: found = false; 2409 } 2410 2411 if (!found) 2412 break; 2413 } 2414 2415 /* get field width */ 2416 spec->field_width = -1; 2417 2418 if (isdigit(*fmt)) 2419 spec->field_width = skip_atoi(&fmt); 2420 else if (*fmt == '*') { 2421 /* it's the next argument */ 2422 spec->type = FORMAT_TYPE_WIDTH; 2423 return ++fmt - start; 2424 } 2425 2426 precision: 2427 /* get the precision */ 2428 spec->precision = -1; 2429 if (*fmt == '.') { 2430 ++fmt; 2431 if (isdigit(*fmt)) { 2432 spec->precision = skip_atoi(&fmt); 2433 if (spec->precision < 0) 2434 spec->precision = 0; 2435 } else if (*fmt == '*') { 2436 /* it's the next argument */ 2437 spec->type = FORMAT_TYPE_PRECISION; 2438 return ++fmt - start; 2439 } 2440 } 2441 2442 qualifier: 2443 /* get the conversion qualifier */ 2444 qualifier = 0; 2445 if (*fmt == 'h' || _tolower(*fmt) == 'l' || 2446 *fmt == 'z' || *fmt == 't') { 2447 qualifier = *fmt++; 2448 if (unlikely(qualifier == *fmt)) { 2449 if (qualifier == 'l') { 2450 qualifier = 'L'; 2451 ++fmt; 2452 } else if (qualifier == 'h') { 2453 qualifier = 'H'; 2454 ++fmt; 2455 } 2456 } 2457 } 2458 2459 /* default base */ 2460 spec->base = 10; 2461 switch (*fmt) { 2462 case 'c': 2463 spec->type = FORMAT_TYPE_CHAR; 2464 return ++fmt - start; 2465 2466 case 's': 2467 spec->type = FORMAT_TYPE_STR; 2468 return ++fmt - start; 2469 2470 case 'p': 2471 spec->type = FORMAT_TYPE_PTR; 2472 return ++fmt - start; 2473 2474 case '%': 2475 spec->type = FORMAT_TYPE_PERCENT_CHAR; 2476 return ++fmt - start; 2477 2478 /* integer number formats - set up the flags and "break" */ 2479 case 'o': 2480 spec->base = 8; 2481 break; 2482 2483 case 'x': 2484 spec->flags |= SMALL; 2485 fallthrough; 2486 2487 case 'X': 2488 spec->base = 16; 2489 break; 2490 2491 case 'd': 2492 case 'i': 2493 spec->flags |= SIGN; 2494 break; 2495 case 'u': 2496 break; 2497 2498 case 'n': 2499 /* 2500 * Since %n poses a greater security risk than 2501 * utility, treat it as any other invalid or 2502 * unsupported format specifier. 2503 */ 2504 fallthrough; 2505 2506 default: 2507 WARN_ONCE(1, "Please remove unsupported %%%c in format string\n", *fmt); 2508 spec->type = FORMAT_TYPE_INVALID; 2509 return fmt - start; 2510 } 2511 2512 if (qualifier == 'L') 2513 spec->type = FORMAT_TYPE_LONG_LONG; 2514 else if (qualifier == 'l') { 2515 BUILD_BUG_ON(FORMAT_TYPE_ULONG + SIGN != FORMAT_TYPE_LONG); 2516 spec->type = FORMAT_TYPE_ULONG + (spec->flags & SIGN); 2517 } else if (qualifier == 'z') { 2518 spec->type = FORMAT_TYPE_SIZE_T; 2519 } else if (qualifier == 't') { 2520 spec->type = FORMAT_TYPE_PTRDIFF; 2521 } else if (qualifier == 'H') { 2522 BUILD_BUG_ON(FORMAT_TYPE_UBYTE + SIGN != FORMAT_TYPE_BYTE); 2523 spec->type = FORMAT_TYPE_UBYTE + (spec->flags & SIGN); 2524 } else if (qualifier == 'h') { 2525 BUILD_BUG_ON(FORMAT_TYPE_USHORT + SIGN != FORMAT_TYPE_SHORT); 2526 spec->type = FORMAT_TYPE_USHORT + (spec->flags & SIGN); 2527 } else { 2528 BUILD_BUG_ON(FORMAT_TYPE_UINT + SIGN != FORMAT_TYPE_INT); 2529 spec->type = FORMAT_TYPE_UINT + (spec->flags & SIGN); 2530 } 2531 2532 return ++fmt - start; 2533 } 2534 2535 static void 2536 set_field_width(struct printf_spec *spec, int width) 2537 { 2538 spec->field_width = width; 2539 if (WARN_ONCE(spec->field_width != width, "field width %d too large", width)) { 2540 spec->field_width = clamp(width, -FIELD_WIDTH_MAX, FIELD_WIDTH_MAX); 2541 } 2542 } 2543 2544 static void 2545 set_precision(struct printf_spec *spec, int prec) 2546 { 2547 spec->precision = prec; 2548 if (WARN_ONCE(spec->precision != prec, "precision %d too large", prec)) { 2549 spec->precision = clamp(prec, 0, PRECISION_MAX); 2550 } 2551 } 2552 2553 /** 2554 * vsnprintf - Format a string and place it in a buffer 2555 * @buf: The buffer to place the result into 2556 * @size: The size of the buffer, including the trailing null space 2557 * @fmt: The format string to use 2558 * @args: Arguments for the format string 2559 * 2560 * This function generally follows C99 vsnprintf, but has some 2561 * extensions and a few limitations: 2562 * 2563 * - ``%n`` is unsupported 2564 * - ``%p*`` is handled by pointer() 2565 * 2566 * See pointer() or Documentation/core-api/printk-formats.rst for more 2567 * extensive description. 2568 * 2569 * **Please update the documentation in both places when making changes** 2570 * 2571 * The return value is the number of characters which would 2572 * be generated for the given input, excluding the trailing 2573 * '\0', as per ISO C99. If you want to have the exact 2574 * number of characters written into @buf as return value 2575 * (not including the trailing '\0'), use vscnprintf(). If the 2576 * return is greater than or equal to @size, the resulting 2577 * string is truncated. 2578 * 2579 * If you're not already dealing with a va_list consider using snprintf(). 2580 */ 2581 int vsnprintf(char *buf, size_t size, const char *fmt, va_list args) 2582 { 2583 unsigned long long num; 2584 char *str, *end; 2585 struct printf_spec spec = {0}; 2586 2587 /* Reject out-of-range values early. Large positive sizes are 2588 used for unknown buffer sizes. */ 2589 if (WARN_ON_ONCE(size > INT_MAX)) 2590 return 0; 2591 2592 str = buf; 2593 end = buf + size; 2594 2595 /* Make sure end is always >= buf */ 2596 if (end < buf) { 2597 end = ((void *)-1); 2598 size = end - buf; 2599 } 2600 2601 while (*fmt) { 2602 const char *old_fmt = fmt; 2603 int read = format_decode(fmt, &spec); 2604 2605 fmt += read; 2606 2607 switch (spec.type) { 2608 case FORMAT_TYPE_NONE: { 2609 int copy = read; 2610 if (str < end) { 2611 if (copy > end - str) 2612 copy = end - str; 2613 memcpy(str, old_fmt, copy); 2614 } 2615 str += read; 2616 break; 2617 } 2618 2619 case FORMAT_TYPE_WIDTH: 2620 set_field_width(&spec, va_arg(args, int)); 2621 break; 2622 2623 case FORMAT_TYPE_PRECISION: 2624 set_precision(&spec, va_arg(args, int)); 2625 break; 2626 2627 case FORMAT_TYPE_CHAR: { 2628 char c; 2629 2630 if (!(spec.flags & LEFT)) { 2631 while (--spec.field_width > 0) { 2632 if (str < end) 2633 *str = ' '; 2634 ++str; 2635 2636 } 2637 } 2638 c = (unsigned char) va_arg(args, int); 2639 if (str < end) 2640 *str = c; 2641 ++str; 2642 while (--spec.field_width > 0) { 2643 if (str < end) 2644 *str = ' '; 2645 ++str; 2646 } 2647 break; 2648 } 2649 2650 case FORMAT_TYPE_STR: 2651 str = string(str, end, va_arg(args, char *), spec); 2652 break; 2653 2654 case FORMAT_TYPE_PTR: 2655 str = pointer(fmt, str, end, va_arg(args, void *), 2656 spec); 2657 while (isalnum(*fmt)) 2658 fmt++; 2659 break; 2660 2661 case FORMAT_TYPE_PERCENT_CHAR: 2662 if (str < end) 2663 *str = '%'; 2664 ++str; 2665 break; 2666 2667 case FORMAT_TYPE_INVALID: 2668 /* 2669 * Presumably the arguments passed gcc's type 2670 * checking, but there is no safe or sane way 2671 * for us to continue parsing the format and 2672 * fetching from the va_list; the remaining 2673 * specifiers and arguments would be out of 2674 * sync. 2675 */ 2676 goto out; 2677 2678 default: 2679 switch (spec.type) { 2680 case FORMAT_TYPE_LONG_LONG: 2681 num = va_arg(args, long long); 2682 break; 2683 case FORMAT_TYPE_ULONG: 2684 num = va_arg(args, unsigned long); 2685 break; 2686 case FORMAT_TYPE_LONG: 2687 num = va_arg(args, long); 2688 break; 2689 case FORMAT_TYPE_SIZE_T: 2690 if (spec.flags & SIGN) 2691 num = va_arg(args, ssize_t); 2692 else 2693 num = va_arg(args, size_t); 2694 break; 2695 case FORMAT_TYPE_PTRDIFF: 2696 num = va_arg(args, ptrdiff_t); 2697 break; 2698 case FORMAT_TYPE_UBYTE: 2699 num = (unsigned char) va_arg(args, int); 2700 break; 2701 case FORMAT_TYPE_BYTE: 2702 num = (signed char) va_arg(args, int); 2703 break; 2704 case FORMAT_TYPE_USHORT: 2705 num = (unsigned short) va_arg(args, int); 2706 break; 2707 case FORMAT_TYPE_SHORT: 2708 num = (short) va_arg(args, int); 2709 break; 2710 case FORMAT_TYPE_INT: 2711 num = (int) va_arg(args, int); 2712 break; 2713 default: 2714 num = va_arg(args, unsigned int); 2715 } 2716 2717 str = number(str, end, num, spec); 2718 } 2719 } 2720 2721 out: 2722 if (size > 0) { 2723 if (str < end) 2724 *str = '\0'; 2725 else 2726 end[-1] = '\0'; 2727 } 2728 2729 /* the trailing null byte doesn't count towards the total */ 2730 return str-buf; 2731 2732 } 2733 EXPORT_SYMBOL(vsnprintf); 2734 2735 /** 2736 * vscnprintf - Format a string and place it in a buffer 2737 * @buf: The buffer to place the result into 2738 * @size: The size of the buffer, including the trailing null space 2739 * @fmt: The format string to use 2740 * @args: Arguments for the format string 2741 * 2742 * The return value is the number of characters which have been written into 2743 * the @buf not including the trailing '\0'. If @size is == 0 the function 2744 * returns 0. 2745 * 2746 * If you're not already dealing with a va_list consider using scnprintf(). 2747 * 2748 * See the vsnprintf() documentation for format string extensions over C99. 2749 */ 2750 int vscnprintf(char *buf, size_t size, const char *fmt, va_list args) 2751 { 2752 int i; 2753 2754 i = vsnprintf(buf, size, fmt, args); 2755 2756 if (likely(i < size)) 2757 return i; 2758 if (size != 0) 2759 return size - 1; 2760 return 0; 2761 } 2762 EXPORT_SYMBOL(vscnprintf); 2763 2764 /** 2765 * snprintf - Format a string and place it in a buffer 2766 * @buf: The buffer to place the result into 2767 * @size: The size of the buffer, including the trailing null space 2768 * @fmt: The format string to use 2769 * @...: Arguments for the format string 2770 * 2771 * The return value is the number of characters which would be 2772 * generated for the given input, excluding the trailing null, 2773 * as per ISO C99. If the return is greater than or equal to 2774 * @size, the resulting string is truncated. 2775 * 2776 * See the vsnprintf() documentation for format string extensions over C99. 2777 */ 2778 int snprintf(char *buf, size_t size, const char *fmt, ...) 2779 { 2780 va_list args; 2781 int i; 2782 2783 va_start(args, fmt); 2784 i = vsnprintf(buf, size, fmt, args); 2785 va_end(args); 2786 2787 return i; 2788 } 2789 EXPORT_SYMBOL(snprintf); 2790 2791 /** 2792 * scnprintf - Format a string and place it in a buffer 2793 * @buf: The buffer to place the result into 2794 * @size: The size of the buffer, including the trailing null space 2795 * @fmt: The format string to use 2796 * @...: Arguments for the format string 2797 * 2798 * The return value is the number of characters written into @buf not including 2799 * the trailing '\0'. If @size is == 0 the function returns 0. 2800 */ 2801 2802 int scnprintf(char *buf, size_t size, const char *fmt, ...) 2803 { 2804 va_list args; 2805 int i; 2806 2807 va_start(args, fmt); 2808 i = vscnprintf(buf, size, fmt, args); 2809 va_end(args); 2810 2811 return i; 2812 } 2813 EXPORT_SYMBOL(scnprintf); 2814 2815 /** 2816 * vsprintf - Format a string and place it in a buffer 2817 * @buf: The buffer to place the result into 2818 * @fmt: The format string to use 2819 * @args: Arguments for the format string 2820 * 2821 * The function returns the number of characters written 2822 * into @buf. Use vsnprintf() or vscnprintf() in order to avoid 2823 * buffer overflows. 2824 * 2825 * If you're not already dealing with a va_list consider using sprintf(). 2826 * 2827 * See the vsnprintf() documentation for format string extensions over C99. 2828 */ 2829 int vsprintf(char *buf, const char *fmt, va_list args) 2830 { 2831 return vsnprintf(buf, INT_MAX, fmt, args); 2832 } 2833 EXPORT_SYMBOL(vsprintf); 2834 2835 /** 2836 * sprintf - Format a string and place it in a buffer 2837 * @buf: The buffer to place the result into 2838 * @fmt: The format string to use 2839 * @...: Arguments for the format string 2840 * 2841 * The function returns the number of characters written 2842 * into @buf. Use snprintf() or scnprintf() in order to avoid 2843 * buffer overflows. 2844 * 2845 * See the vsnprintf() documentation for format string extensions over C99. 2846 */ 2847 int sprintf(char *buf, const char *fmt, ...) 2848 { 2849 va_list args; 2850 int i; 2851 2852 va_start(args, fmt); 2853 i = vsnprintf(buf, INT_MAX, fmt, args); 2854 va_end(args); 2855 2856 return i; 2857 } 2858 EXPORT_SYMBOL(sprintf); 2859 2860 #ifdef CONFIG_BINARY_PRINTF 2861 /* 2862 * bprintf service: 2863 * vbin_printf() - VA arguments to binary data 2864 * bstr_printf() - Binary data to text string 2865 */ 2866 2867 /** 2868 * vbin_printf - Parse a format string and place args' binary value in a buffer 2869 * @bin_buf: The buffer to place args' binary value 2870 * @size: The size of the buffer(by words(32bits), not characters) 2871 * @fmt: The format string to use 2872 * @args: Arguments for the format string 2873 * 2874 * The format follows C99 vsnprintf, except %n is ignored, and its argument 2875 * is skipped. 2876 * 2877 * The return value is the number of words(32bits) which would be generated for 2878 * the given input. 2879 * 2880 * NOTE: 2881 * If the return value is greater than @size, the resulting bin_buf is NOT 2882 * valid for bstr_printf(). 2883 */ 2884 int vbin_printf(u32 *bin_buf, size_t size, const char *fmt, va_list args) 2885 { 2886 struct printf_spec spec = {0}; 2887 char *str, *end; 2888 int width; 2889 2890 str = (char *)bin_buf; 2891 end = (char *)(bin_buf + size); 2892 2893 #define save_arg(type) \ 2894 ({ \ 2895 unsigned long long value; \ 2896 if (sizeof(type) == 8) { \ 2897 unsigned long long val8; \ 2898 str = PTR_ALIGN(str, sizeof(u32)); \ 2899 val8 = va_arg(args, unsigned long long); \ 2900 if (str + sizeof(type) <= end) { \ 2901 *(u32 *)str = *(u32 *)&val8; \ 2902 *(u32 *)(str + 4) = *((u32 *)&val8 + 1); \ 2903 } \ 2904 value = val8; \ 2905 } else { \ 2906 unsigned int val4; \ 2907 str = PTR_ALIGN(str, sizeof(type)); \ 2908 val4 = va_arg(args, int); \ 2909 if (str + sizeof(type) <= end) \ 2910 *(typeof(type) *)str = (type)(long)val4; \ 2911 value = (unsigned long long)val4; \ 2912 } \ 2913 str += sizeof(type); \ 2914 value; \ 2915 }) 2916 2917 while (*fmt) { 2918 int read = format_decode(fmt, &spec); 2919 2920 fmt += read; 2921 2922 switch (spec.type) { 2923 case FORMAT_TYPE_NONE: 2924 case FORMAT_TYPE_PERCENT_CHAR: 2925 break; 2926 case FORMAT_TYPE_INVALID: 2927 goto out; 2928 2929 case FORMAT_TYPE_WIDTH: 2930 case FORMAT_TYPE_PRECISION: 2931 width = (int)save_arg(int); 2932 /* Pointers may require the width */ 2933 if (*fmt == 'p') 2934 set_field_width(&spec, width); 2935 break; 2936 2937 case FORMAT_TYPE_CHAR: 2938 save_arg(char); 2939 break; 2940 2941 case FORMAT_TYPE_STR: { 2942 const char *save_str = va_arg(args, char *); 2943 const char *err_msg; 2944 size_t len; 2945 2946 err_msg = check_pointer_msg(save_str); 2947 if (err_msg) 2948 save_str = err_msg; 2949 2950 len = strlen(save_str) + 1; 2951 if (str + len < end) 2952 memcpy(str, save_str, len); 2953 str += len; 2954 break; 2955 } 2956 2957 case FORMAT_TYPE_PTR: 2958 /* Dereferenced pointers must be done now */ 2959 switch (*fmt) { 2960 /* Dereference of functions is still OK */ 2961 case 'S': 2962 case 's': 2963 case 'x': 2964 case 'K': 2965 case 'e': 2966 save_arg(void *); 2967 break; 2968 default: 2969 if (!isalnum(*fmt)) { 2970 save_arg(void *); 2971 break; 2972 } 2973 str = pointer(fmt, str, end, va_arg(args, void *), 2974 spec); 2975 if (str + 1 < end) 2976 *str++ = '\0'; 2977 else 2978 end[-1] = '\0'; /* Must be nul terminated */ 2979 } 2980 /* skip all alphanumeric pointer suffixes */ 2981 while (isalnum(*fmt)) 2982 fmt++; 2983 break; 2984 2985 default: 2986 switch (spec.type) { 2987 2988 case FORMAT_TYPE_LONG_LONG: 2989 save_arg(long long); 2990 break; 2991 case FORMAT_TYPE_ULONG: 2992 case FORMAT_TYPE_LONG: 2993 save_arg(unsigned long); 2994 break; 2995 case FORMAT_TYPE_SIZE_T: 2996 save_arg(size_t); 2997 break; 2998 case FORMAT_TYPE_PTRDIFF: 2999 save_arg(ptrdiff_t); 3000 break; 3001 case FORMAT_TYPE_UBYTE: 3002 case FORMAT_TYPE_BYTE: 3003 save_arg(char); 3004 break; 3005 case FORMAT_TYPE_USHORT: 3006 case FORMAT_TYPE_SHORT: 3007 save_arg(short); 3008 break; 3009 default: 3010 save_arg(int); 3011 } 3012 } 3013 } 3014 3015 out: 3016 return (u32 *)(PTR_ALIGN(str, sizeof(u32))) - bin_buf; 3017 #undef save_arg 3018 } 3019 EXPORT_SYMBOL_GPL(vbin_printf); 3020 3021 /** 3022 * bstr_printf - Format a string from binary arguments and place it in a buffer 3023 * @buf: The buffer to place the result into 3024 * @size: The size of the buffer, including the trailing null space 3025 * @fmt: The format string to use 3026 * @bin_buf: Binary arguments for the format string 3027 * 3028 * This function like C99 vsnprintf, but the difference is that vsnprintf gets 3029 * arguments from stack, and bstr_printf gets arguments from @bin_buf which is 3030 * a binary buffer that generated by vbin_printf. 3031 * 3032 * The format follows C99 vsnprintf, but has some extensions: 3033 * see vsnprintf comment for details. 3034 * 3035 * The return value is the number of characters which would 3036 * be generated for the given input, excluding the trailing 3037 * '\0', as per ISO C99. If you want to have the exact 3038 * number of characters written into @buf as return value 3039 * (not including the trailing '\0'), use vscnprintf(). If the 3040 * return is greater than or equal to @size, the resulting 3041 * string is truncated. 3042 */ 3043 int bstr_printf(char *buf, size_t size, const char *fmt, const u32 *bin_buf) 3044 { 3045 struct printf_spec spec = {0}; 3046 char *str, *end; 3047 const char *args = (const char *)bin_buf; 3048 3049 if (WARN_ON_ONCE(size > INT_MAX)) 3050 return 0; 3051 3052 str = buf; 3053 end = buf + size; 3054 3055 #define get_arg(type) \ 3056 ({ \ 3057 typeof(type) value; \ 3058 if (sizeof(type) == 8) { \ 3059 args = PTR_ALIGN(args, sizeof(u32)); \ 3060 *(u32 *)&value = *(u32 *)args; \ 3061 *((u32 *)&value + 1) = *(u32 *)(args + 4); \ 3062 } else { \ 3063 args = PTR_ALIGN(args, sizeof(type)); \ 3064 value = *(typeof(type) *)args; \ 3065 } \ 3066 args += sizeof(type); \ 3067 value; \ 3068 }) 3069 3070 /* Make sure end is always >= buf */ 3071 if (end < buf) { 3072 end = ((void *)-1); 3073 size = end - buf; 3074 } 3075 3076 while (*fmt) { 3077 const char *old_fmt = fmt; 3078 int read = format_decode(fmt, &spec); 3079 3080 fmt += read; 3081 3082 switch (spec.type) { 3083 case FORMAT_TYPE_NONE: { 3084 int copy = read; 3085 if (str < end) { 3086 if (copy > end - str) 3087 copy = end - str; 3088 memcpy(str, old_fmt, copy); 3089 } 3090 str += read; 3091 break; 3092 } 3093 3094 case FORMAT_TYPE_WIDTH: 3095 set_field_width(&spec, get_arg(int)); 3096 break; 3097 3098 case FORMAT_TYPE_PRECISION: 3099 set_precision(&spec, get_arg(int)); 3100 break; 3101 3102 case FORMAT_TYPE_CHAR: { 3103 char c; 3104 3105 if (!(spec.flags & LEFT)) { 3106 while (--spec.field_width > 0) { 3107 if (str < end) 3108 *str = ' '; 3109 ++str; 3110 } 3111 } 3112 c = (unsigned char) get_arg(char); 3113 if (str < end) 3114 *str = c; 3115 ++str; 3116 while (--spec.field_width > 0) { 3117 if (str < end) 3118 *str = ' '; 3119 ++str; 3120 } 3121 break; 3122 } 3123 3124 case FORMAT_TYPE_STR: { 3125 const char *str_arg = args; 3126 args += strlen(str_arg) + 1; 3127 str = string(str, end, (char *)str_arg, spec); 3128 break; 3129 } 3130 3131 case FORMAT_TYPE_PTR: { 3132 bool process = false; 3133 int copy, len; 3134 /* Non function dereferences were already done */ 3135 switch (*fmt) { 3136 case 'S': 3137 case 's': 3138 case 'F': 3139 case 'f': 3140 case 'x': 3141 case 'K': 3142 case 'e': 3143 process = true; 3144 break; 3145 default: 3146 if (!isalnum(*fmt)) { 3147 process = true; 3148 break; 3149 } 3150 /* Pointer dereference was already processed */ 3151 if (str < end) { 3152 len = copy = strlen(args); 3153 if (copy > end - str) 3154 copy = end - str; 3155 memcpy(str, args, copy); 3156 str += len; 3157 args += len + 1; 3158 } 3159 } 3160 if (process) 3161 str = pointer(fmt, str, end, get_arg(void *), spec); 3162 3163 while (isalnum(*fmt)) 3164 fmt++; 3165 break; 3166 } 3167 3168 case FORMAT_TYPE_PERCENT_CHAR: 3169 if (str < end) 3170 *str = '%'; 3171 ++str; 3172 break; 3173 3174 case FORMAT_TYPE_INVALID: 3175 goto out; 3176 3177 default: { 3178 unsigned long long num; 3179 3180 switch (spec.type) { 3181 3182 case FORMAT_TYPE_LONG_LONG: 3183 num = get_arg(long long); 3184 break; 3185 case FORMAT_TYPE_ULONG: 3186 case FORMAT_TYPE_LONG: 3187 num = get_arg(unsigned long); 3188 break; 3189 case FORMAT_TYPE_SIZE_T: 3190 num = get_arg(size_t); 3191 break; 3192 case FORMAT_TYPE_PTRDIFF: 3193 num = get_arg(ptrdiff_t); 3194 break; 3195 case FORMAT_TYPE_UBYTE: 3196 num = get_arg(unsigned char); 3197 break; 3198 case FORMAT_TYPE_BYTE: 3199 num = get_arg(signed char); 3200 break; 3201 case FORMAT_TYPE_USHORT: 3202 num = get_arg(unsigned short); 3203 break; 3204 case FORMAT_TYPE_SHORT: 3205 num = get_arg(short); 3206 break; 3207 case FORMAT_TYPE_UINT: 3208 num = get_arg(unsigned int); 3209 break; 3210 default: 3211 num = get_arg(int); 3212 } 3213 3214 str = number(str, end, num, spec); 3215 } /* default: */ 3216 } /* switch(spec.type) */ 3217 } /* while(*fmt) */ 3218 3219 out: 3220 if (size > 0) { 3221 if (str < end) 3222 *str = '\0'; 3223 else 3224 end[-1] = '\0'; 3225 } 3226 3227 #undef get_arg 3228 3229 /* the trailing null byte doesn't count towards the total */ 3230 return str - buf; 3231 } 3232 EXPORT_SYMBOL_GPL(bstr_printf); 3233 3234 /** 3235 * bprintf - Parse a format string and place args' binary value in a buffer 3236 * @bin_buf: The buffer to place args' binary value 3237 * @size: The size of the buffer(by words(32bits), not characters) 3238 * @fmt: The format string to use 3239 * @...: Arguments for the format string 3240 * 3241 * The function returns the number of words(u32) written 3242 * into @bin_buf. 3243 */ 3244 int bprintf(u32 *bin_buf, size_t size, const char *fmt, ...) 3245 { 3246 va_list args; 3247 int ret; 3248 3249 va_start(args, fmt); 3250 ret = vbin_printf(bin_buf, size, fmt, args); 3251 va_end(args); 3252 3253 return ret; 3254 } 3255 EXPORT_SYMBOL_GPL(bprintf); 3256 3257 #endif /* CONFIG_BINARY_PRINTF */ 3258 3259 /** 3260 * vsscanf - Unformat a buffer into a list of arguments 3261 * @buf: input buffer 3262 * @fmt: format of buffer 3263 * @args: arguments 3264 */ 3265 int vsscanf(const char *buf, const char *fmt, va_list args) 3266 { 3267 const char *str = buf; 3268 char *next; 3269 char digit; 3270 int num = 0; 3271 u8 qualifier; 3272 unsigned int base; 3273 union { 3274 long long s; 3275 unsigned long long u; 3276 } val; 3277 s16 field_width; 3278 bool is_sign; 3279 3280 while (*fmt) { 3281 /* skip any white space in format */ 3282 /* white space in format matchs any amount of 3283 * white space, including none, in the input. 3284 */ 3285 if (isspace(*fmt)) { 3286 fmt = skip_spaces(++fmt); 3287 str = skip_spaces(str); 3288 } 3289 3290 /* anything that is not a conversion must match exactly */ 3291 if (*fmt != '%' && *fmt) { 3292 if (*fmt++ != *str++) 3293 break; 3294 continue; 3295 } 3296 3297 if (!*fmt) 3298 break; 3299 ++fmt; 3300 3301 /* skip this conversion. 3302 * advance both strings to next white space 3303 */ 3304 if (*fmt == '*') { 3305 if (!*str) 3306 break; 3307 while (!isspace(*fmt) && *fmt != '%' && *fmt) { 3308 /* '%*[' not yet supported, invalid format */ 3309 if (*fmt == '[') 3310 return num; 3311 fmt++; 3312 } 3313 while (!isspace(*str) && *str) 3314 str++; 3315 continue; 3316 } 3317 3318 /* get field width */ 3319 field_width = -1; 3320 if (isdigit(*fmt)) { 3321 field_width = skip_atoi(&fmt); 3322 if (field_width <= 0) 3323 break; 3324 } 3325 3326 /* get conversion qualifier */ 3327 qualifier = -1; 3328 if (*fmt == 'h' || _tolower(*fmt) == 'l' || 3329 *fmt == 'z') { 3330 qualifier = *fmt++; 3331 if (unlikely(qualifier == *fmt)) { 3332 if (qualifier == 'h') { 3333 qualifier = 'H'; 3334 fmt++; 3335 } else if (qualifier == 'l') { 3336 qualifier = 'L'; 3337 fmt++; 3338 } 3339 } 3340 } 3341 3342 if (!*fmt) 3343 break; 3344 3345 if (*fmt == 'n') { 3346 /* return number of characters read so far */ 3347 *va_arg(args, int *) = str - buf; 3348 ++fmt; 3349 continue; 3350 } 3351 3352 if (!*str) 3353 break; 3354 3355 base = 10; 3356 is_sign = false; 3357 3358 switch (*fmt++) { 3359 case 'c': 3360 { 3361 char *s = (char *)va_arg(args, char*); 3362 if (field_width == -1) 3363 field_width = 1; 3364 do { 3365 *s++ = *str++; 3366 } while (--field_width > 0 && *str); 3367 num++; 3368 } 3369 continue; 3370 case 's': 3371 { 3372 char *s = (char *)va_arg(args, char *); 3373 if (field_width == -1) 3374 field_width = SHRT_MAX; 3375 /* first, skip leading white space in buffer */ 3376 str = skip_spaces(str); 3377 3378 /* now copy until next white space */ 3379 while (*str && !isspace(*str) && field_width--) 3380 *s++ = *str++; 3381 *s = '\0'; 3382 num++; 3383 } 3384 continue; 3385 /* 3386 * Warning: This implementation of the '[' conversion specifier 3387 * deviates from its glibc counterpart in the following ways: 3388 * (1) It does NOT support ranges i.e. '-' is NOT a special 3389 * character 3390 * (2) It cannot match the closing bracket ']' itself 3391 * (3) A field width is required 3392 * (4) '%*[' (discard matching input) is currently not supported 3393 * 3394 * Example usage: 3395 * ret = sscanf("00:0a:95","%2[^:]:%2[^:]:%2[^:]", 3396 * buf1, buf2, buf3); 3397 * if (ret < 3) 3398 * // etc.. 3399 */ 3400 case '[': 3401 { 3402 char *s = (char *)va_arg(args, char *); 3403 DECLARE_BITMAP(set, 256) = {0}; 3404 unsigned int len = 0; 3405 bool negate = (*fmt == '^'); 3406 3407 /* field width is required */ 3408 if (field_width == -1) 3409 return num; 3410 3411 if (negate) 3412 ++fmt; 3413 3414 for ( ; *fmt && *fmt != ']'; ++fmt, ++len) 3415 set_bit((u8)*fmt, set); 3416 3417 /* no ']' or no character set found */ 3418 if (!*fmt || !len) 3419 return num; 3420 ++fmt; 3421 3422 if (negate) { 3423 bitmap_complement(set, set, 256); 3424 /* exclude null '\0' byte */ 3425 clear_bit(0, set); 3426 } 3427 3428 /* match must be non-empty */ 3429 if (!test_bit((u8)*str, set)) 3430 return num; 3431 3432 while (test_bit((u8)*str, set) && field_width--) 3433 *s++ = *str++; 3434 *s = '\0'; 3435 ++num; 3436 } 3437 continue; 3438 case 'o': 3439 base = 8; 3440 break; 3441 case 'x': 3442 case 'X': 3443 base = 16; 3444 break; 3445 case 'i': 3446 base = 0; 3447 fallthrough; 3448 case 'd': 3449 is_sign = true; 3450 fallthrough; 3451 case 'u': 3452 break; 3453 case '%': 3454 /* looking for '%' in str */ 3455 if (*str++ != '%') 3456 return num; 3457 continue; 3458 default: 3459 /* invalid format; stop here */ 3460 return num; 3461 } 3462 3463 /* have some sort of integer conversion. 3464 * first, skip white space in buffer. 3465 */ 3466 str = skip_spaces(str); 3467 3468 digit = *str; 3469 if (is_sign && digit == '-') 3470 digit = *(str + 1); 3471 3472 if (!digit 3473 || (base == 16 && !isxdigit(digit)) 3474 || (base == 10 && !isdigit(digit)) 3475 || (base == 8 && (!isdigit(digit) || digit > '7')) 3476 || (base == 0 && !isdigit(digit))) 3477 break; 3478 3479 if (is_sign) 3480 val.s = qualifier != 'L' ? 3481 simple_strtol(str, &next, base) : 3482 simple_strtoll(str, &next, base); 3483 else 3484 val.u = qualifier != 'L' ? 3485 simple_strtoul(str, &next, base) : 3486 simple_strtoull(str, &next, base); 3487 3488 if (field_width > 0 && next - str > field_width) { 3489 if (base == 0) 3490 _parse_integer_fixup_radix(str, &base); 3491 while (next - str > field_width) { 3492 if (is_sign) 3493 val.s = div_s64(val.s, base); 3494 else 3495 val.u = div_u64(val.u, base); 3496 --next; 3497 } 3498 } 3499 3500 switch (qualifier) { 3501 case 'H': /* that's 'hh' in format */ 3502 if (is_sign) 3503 *va_arg(args, signed char *) = val.s; 3504 else 3505 *va_arg(args, unsigned char *) = val.u; 3506 break; 3507 case 'h': 3508 if (is_sign) 3509 *va_arg(args, short *) = val.s; 3510 else 3511 *va_arg(args, unsigned short *) = val.u; 3512 break; 3513 case 'l': 3514 if (is_sign) 3515 *va_arg(args, long *) = val.s; 3516 else 3517 *va_arg(args, unsigned long *) = val.u; 3518 break; 3519 case 'L': 3520 if (is_sign) 3521 *va_arg(args, long long *) = val.s; 3522 else 3523 *va_arg(args, unsigned long long *) = val.u; 3524 break; 3525 case 'z': 3526 *va_arg(args, size_t *) = val.u; 3527 break; 3528 default: 3529 if (is_sign) 3530 *va_arg(args, int *) = val.s; 3531 else 3532 *va_arg(args, unsigned int *) = val.u; 3533 break; 3534 } 3535 num++; 3536 3537 if (!next) 3538 break; 3539 str = next; 3540 } 3541 3542 return num; 3543 } 3544 EXPORT_SYMBOL(vsscanf); 3545 3546 /** 3547 * sscanf - Unformat a buffer into a list of arguments 3548 * @buf: input buffer 3549 * @fmt: formatting of buffer 3550 * @...: resulting arguments 3551 */ 3552 int sscanf(const char *buf, const char *fmt, ...) 3553 { 3554 va_list args; 3555 int i; 3556 3557 va_start(args, fmt); 3558 i = vsscanf(buf, fmt, args); 3559 va_end(args); 3560 3561 return i; 3562 } 3563 EXPORT_SYMBOL(sscanf); 3564