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 *fourcc_string(char *buf, char *end, const u32 *fourcc, 1738 struct printf_spec spec, const char *fmt) 1739 { 1740 char output[sizeof("0123 little-endian (0x01234567)")]; 1741 char *p = output; 1742 unsigned int i; 1743 u32 val; 1744 1745 if (fmt[1] != 'c' || fmt[2] != 'c') 1746 return error_string(buf, end, "(%p4?)", spec); 1747 1748 if (check_pointer(&buf, end, fourcc, spec)) 1749 return buf; 1750 1751 val = *fourcc & ~BIT(31); 1752 1753 for (i = 0; i < sizeof(*fourcc); i++) { 1754 unsigned char c = val >> (i * 8); 1755 1756 /* Print non-control ASCII characters as-is, dot otherwise */ 1757 *p++ = isascii(c) && isprint(c) ? c : '.'; 1758 } 1759 1760 strcpy(p, *fourcc & BIT(31) ? " big-endian" : " little-endian"); 1761 p += strlen(p); 1762 1763 *p++ = ' '; 1764 *p++ = '('; 1765 p = special_hex_number(p, output + sizeof(output) - 2, *fourcc, sizeof(u32)); 1766 *p++ = ')'; 1767 *p = '\0'; 1768 1769 return string(buf, end, output, spec); 1770 } 1771 1772 static noinline_for_stack 1773 char *address_val(char *buf, char *end, const void *addr, 1774 struct printf_spec spec, const char *fmt) 1775 { 1776 unsigned long long num; 1777 int size; 1778 1779 if (check_pointer(&buf, end, addr, spec)) 1780 return buf; 1781 1782 switch (fmt[1]) { 1783 case 'd': 1784 num = *(const dma_addr_t *)addr; 1785 size = sizeof(dma_addr_t); 1786 break; 1787 case 'p': 1788 default: 1789 num = *(const phys_addr_t *)addr; 1790 size = sizeof(phys_addr_t); 1791 break; 1792 } 1793 1794 return special_hex_number(buf, end, num, size); 1795 } 1796 1797 static noinline_for_stack 1798 char *date_str(char *buf, char *end, const struct rtc_time *tm, bool r) 1799 { 1800 int year = tm->tm_year + (r ? 0 : 1900); 1801 int mon = tm->tm_mon + (r ? 0 : 1); 1802 1803 buf = number(buf, end, year, default_dec04_spec); 1804 if (buf < end) 1805 *buf = '-'; 1806 buf++; 1807 1808 buf = number(buf, end, mon, default_dec02_spec); 1809 if (buf < end) 1810 *buf = '-'; 1811 buf++; 1812 1813 return number(buf, end, tm->tm_mday, default_dec02_spec); 1814 } 1815 1816 static noinline_for_stack 1817 char *time_str(char *buf, char *end, const struct rtc_time *tm, bool r) 1818 { 1819 buf = number(buf, end, tm->tm_hour, default_dec02_spec); 1820 if (buf < end) 1821 *buf = ':'; 1822 buf++; 1823 1824 buf = number(buf, end, tm->tm_min, default_dec02_spec); 1825 if (buf < end) 1826 *buf = ':'; 1827 buf++; 1828 1829 return number(buf, end, tm->tm_sec, default_dec02_spec); 1830 } 1831 1832 static noinline_for_stack 1833 char *rtc_str(char *buf, char *end, const struct rtc_time *tm, 1834 struct printf_spec spec, const char *fmt) 1835 { 1836 bool have_t = true, have_d = true; 1837 bool raw = false; 1838 int count = 2; 1839 1840 if (check_pointer(&buf, end, tm, spec)) 1841 return buf; 1842 1843 switch (fmt[count]) { 1844 case 'd': 1845 have_t = false; 1846 count++; 1847 break; 1848 case 't': 1849 have_d = false; 1850 count++; 1851 break; 1852 } 1853 1854 raw = fmt[count] == 'r'; 1855 1856 if (have_d) 1857 buf = date_str(buf, end, tm, raw); 1858 if (have_d && have_t) { 1859 /* Respect ISO 8601 */ 1860 if (buf < end) 1861 *buf = 'T'; 1862 buf++; 1863 } 1864 if (have_t) 1865 buf = time_str(buf, end, tm, raw); 1866 1867 return buf; 1868 } 1869 1870 static noinline_for_stack 1871 char *time64_str(char *buf, char *end, const time64_t time, 1872 struct printf_spec spec, const char *fmt) 1873 { 1874 struct rtc_time rtc_time; 1875 struct tm tm; 1876 1877 time64_to_tm(time, 0, &tm); 1878 1879 rtc_time.tm_sec = tm.tm_sec; 1880 rtc_time.tm_min = tm.tm_min; 1881 rtc_time.tm_hour = tm.tm_hour; 1882 rtc_time.tm_mday = tm.tm_mday; 1883 rtc_time.tm_mon = tm.tm_mon; 1884 rtc_time.tm_year = tm.tm_year; 1885 rtc_time.tm_wday = tm.tm_wday; 1886 rtc_time.tm_yday = tm.tm_yday; 1887 1888 rtc_time.tm_isdst = 0; 1889 1890 return rtc_str(buf, end, &rtc_time, spec, fmt); 1891 } 1892 1893 static noinline_for_stack 1894 char *time_and_date(char *buf, char *end, void *ptr, struct printf_spec spec, 1895 const char *fmt) 1896 { 1897 switch (fmt[1]) { 1898 case 'R': 1899 return rtc_str(buf, end, (const struct rtc_time *)ptr, spec, fmt); 1900 case 'T': 1901 return time64_str(buf, end, *(const time64_t *)ptr, spec, fmt); 1902 default: 1903 return error_string(buf, end, "(%pt?)", spec); 1904 } 1905 } 1906 1907 static noinline_for_stack 1908 char *clock(char *buf, char *end, struct clk *clk, struct printf_spec spec, 1909 const char *fmt) 1910 { 1911 if (!IS_ENABLED(CONFIG_HAVE_CLK)) 1912 return error_string(buf, end, "(%pC?)", spec); 1913 1914 if (check_pointer(&buf, end, clk, spec)) 1915 return buf; 1916 1917 switch (fmt[1]) { 1918 case 'n': 1919 default: 1920 #ifdef CONFIG_COMMON_CLK 1921 return string(buf, end, __clk_get_name(clk), spec); 1922 #else 1923 return ptr_to_id(buf, end, clk, spec); 1924 #endif 1925 } 1926 } 1927 1928 static 1929 char *format_flags(char *buf, char *end, unsigned long flags, 1930 const struct trace_print_flags *names) 1931 { 1932 unsigned long mask; 1933 1934 for ( ; flags && names->name; names++) { 1935 mask = names->mask; 1936 if ((flags & mask) != mask) 1937 continue; 1938 1939 buf = string(buf, end, names->name, default_str_spec); 1940 1941 flags &= ~mask; 1942 if (flags) { 1943 if (buf < end) 1944 *buf = '|'; 1945 buf++; 1946 } 1947 } 1948 1949 if (flags) 1950 buf = number(buf, end, flags, default_flag_spec); 1951 1952 return buf; 1953 } 1954 1955 struct page_flags_fields { 1956 int width; 1957 int shift; 1958 int mask; 1959 const struct printf_spec *spec; 1960 const char *name; 1961 }; 1962 1963 static const struct page_flags_fields pff[] = { 1964 {SECTIONS_WIDTH, SECTIONS_PGSHIFT, SECTIONS_MASK, 1965 &default_dec_spec, "section"}, 1966 {NODES_WIDTH, NODES_PGSHIFT, NODES_MASK, 1967 &default_dec_spec, "node"}, 1968 {ZONES_WIDTH, ZONES_PGSHIFT, ZONES_MASK, 1969 &default_dec_spec, "zone"}, 1970 {LAST_CPUPID_WIDTH, LAST_CPUPID_PGSHIFT, LAST_CPUPID_MASK, 1971 &default_flag_spec, "lastcpupid"}, 1972 {KASAN_TAG_WIDTH, KASAN_TAG_PGSHIFT, KASAN_TAG_MASK, 1973 &default_flag_spec, "kasantag"}, 1974 }; 1975 1976 static 1977 char *format_page_flags(char *buf, char *end, unsigned long flags) 1978 { 1979 unsigned long main_flags = flags & (BIT(NR_PAGEFLAGS) - 1); 1980 bool append = false; 1981 int i; 1982 1983 /* Page flags from the main area. */ 1984 if (main_flags) { 1985 buf = format_flags(buf, end, main_flags, pageflag_names); 1986 append = true; 1987 } 1988 1989 /* Page flags from the fields area */ 1990 for (i = 0; i < ARRAY_SIZE(pff); i++) { 1991 /* Skip undefined fields. */ 1992 if (!pff[i].width) 1993 continue; 1994 1995 /* Format: Flag Name + '=' (equals sign) + Number + '|' (separator) */ 1996 if (append) { 1997 if (buf < end) 1998 *buf = '|'; 1999 buf++; 2000 } 2001 2002 buf = string(buf, end, pff[i].name, default_str_spec); 2003 if (buf < end) 2004 *buf = '='; 2005 buf++; 2006 buf = number(buf, end, (flags >> pff[i].shift) & pff[i].mask, 2007 *pff[i].spec); 2008 2009 append = true; 2010 } 2011 2012 return buf; 2013 } 2014 2015 static noinline_for_stack 2016 char *flags_string(char *buf, char *end, void *flags_ptr, 2017 struct printf_spec spec, const char *fmt) 2018 { 2019 unsigned long flags; 2020 const struct trace_print_flags *names; 2021 2022 if (check_pointer(&buf, end, flags_ptr, spec)) 2023 return buf; 2024 2025 switch (fmt[1]) { 2026 case 'p': 2027 return format_page_flags(buf, end, *(unsigned long *)flags_ptr); 2028 case 'v': 2029 flags = *(unsigned long *)flags_ptr; 2030 names = vmaflag_names; 2031 break; 2032 case 'g': 2033 flags = (__force unsigned long)(*(gfp_t *)flags_ptr); 2034 names = gfpflag_names; 2035 break; 2036 default: 2037 return error_string(buf, end, "(%pG?)", spec); 2038 } 2039 2040 return format_flags(buf, end, flags, names); 2041 } 2042 2043 static noinline_for_stack 2044 char *fwnode_full_name_string(struct fwnode_handle *fwnode, char *buf, 2045 char *end) 2046 { 2047 int depth; 2048 2049 /* Loop starting from the root node to the current node. */ 2050 for (depth = fwnode_count_parents(fwnode); depth >= 0; depth--) { 2051 struct fwnode_handle *__fwnode = 2052 fwnode_get_nth_parent(fwnode, depth); 2053 2054 buf = string(buf, end, fwnode_get_name_prefix(__fwnode), 2055 default_str_spec); 2056 buf = string(buf, end, fwnode_get_name(__fwnode), 2057 default_str_spec); 2058 2059 fwnode_handle_put(__fwnode); 2060 } 2061 2062 return buf; 2063 } 2064 2065 static noinline_for_stack 2066 char *device_node_string(char *buf, char *end, struct device_node *dn, 2067 struct printf_spec spec, const char *fmt) 2068 { 2069 char tbuf[sizeof("xxxx") + 1]; 2070 const char *p; 2071 int ret; 2072 char *buf_start = buf; 2073 struct property *prop; 2074 bool has_mult, pass; 2075 2076 struct printf_spec str_spec = spec; 2077 str_spec.field_width = -1; 2078 2079 if (fmt[0] != 'F') 2080 return error_string(buf, end, "(%pO?)", spec); 2081 2082 if (!IS_ENABLED(CONFIG_OF)) 2083 return error_string(buf, end, "(%pOF?)", spec); 2084 2085 if (check_pointer(&buf, end, dn, spec)) 2086 return buf; 2087 2088 /* simple case without anything any more format specifiers */ 2089 fmt++; 2090 if (fmt[0] == '\0' || strcspn(fmt,"fnpPFcC") > 0) 2091 fmt = "f"; 2092 2093 for (pass = false; strspn(fmt,"fnpPFcC"); fmt++, pass = true) { 2094 int precision; 2095 if (pass) { 2096 if (buf < end) 2097 *buf = ':'; 2098 buf++; 2099 } 2100 2101 switch (*fmt) { 2102 case 'f': /* full_name */ 2103 buf = fwnode_full_name_string(of_fwnode_handle(dn), buf, 2104 end); 2105 break; 2106 case 'n': /* name */ 2107 p = fwnode_get_name(of_fwnode_handle(dn)); 2108 precision = str_spec.precision; 2109 str_spec.precision = strchrnul(p, '@') - p; 2110 buf = string(buf, end, p, str_spec); 2111 str_spec.precision = precision; 2112 break; 2113 case 'p': /* phandle */ 2114 buf = number(buf, end, (unsigned int)dn->phandle, default_dec_spec); 2115 break; 2116 case 'P': /* path-spec */ 2117 p = fwnode_get_name(of_fwnode_handle(dn)); 2118 if (!p[1]) 2119 p = "/"; 2120 buf = string(buf, end, p, str_spec); 2121 break; 2122 case 'F': /* flags */ 2123 tbuf[0] = of_node_check_flag(dn, OF_DYNAMIC) ? 'D' : '-'; 2124 tbuf[1] = of_node_check_flag(dn, OF_DETACHED) ? 'd' : '-'; 2125 tbuf[2] = of_node_check_flag(dn, OF_POPULATED) ? 'P' : '-'; 2126 tbuf[3] = of_node_check_flag(dn, OF_POPULATED_BUS) ? 'B' : '-'; 2127 tbuf[4] = 0; 2128 buf = string_nocheck(buf, end, tbuf, str_spec); 2129 break; 2130 case 'c': /* major compatible string */ 2131 ret = of_property_read_string(dn, "compatible", &p); 2132 if (!ret) 2133 buf = string(buf, end, p, str_spec); 2134 break; 2135 case 'C': /* full compatible string */ 2136 has_mult = false; 2137 of_property_for_each_string(dn, "compatible", prop, p) { 2138 if (has_mult) 2139 buf = string_nocheck(buf, end, ",", str_spec); 2140 buf = string_nocheck(buf, end, "\"", str_spec); 2141 buf = string(buf, end, p, str_spec); 2142 buf = string_nocheck(buf, end, "\"", str_spec); 2143 2144 has_mult = true; 2145 } 2146 break; 2147 default: 2148 break; 2149 } 2150 } 2151 2152 return widen_string(buf, buf - buf_start, end, spec); 2153 } 2154 2155 static noinline_for_stack 2156 char *fwnode_string(char *buf, char *end, struct fwnode_handle *fwnode, 2157 struct printf_spec spec, const char *fmt) 2158 { 2159 struct printf_spec str_spec = spec; 2160 char *buf_start = buf; 2161 2162 str_spec.field_width = -1; 2163 2164 if (*fmt != 'w') 2165 return error_string(buf, end, "(%pf?)", spec); 2166 2167 if (check_pointer(&buf, end, fwnode, spec)) 2168 return buf; 2169 2170 fmt++; 2171 2172 switch (*fmt) { 2173 case 'P': /* name */ 2174 buf = string(buf, end, fwnode_get_name(fwnode), str_spec); 2175 break; 2176 case 'f': /* full_name */ 2177 default: 2178 buf = fwnode_full_name_string(fwnode, buf, end); 2179 break; 2180 } 2181 2182 return widen_string(buf, buf - buf_start, end, spec); 2183 } 2184 2185 /* Disable pointer hashing if requested */ 2186 bool no_hash_pointers __ro_after_init; 2187 EXPORT_SYMBOL_GPL(no_hash_pointers); 2188 2189 static int __init no_hash_pointers_enable(char *str) 2190 { 2191 if (no_hash_pointers) 2192 return 0; 2193 2194 no_hash_pointers = true; 2195 2196 pr_warn("**********************************************************\n"); 2197 pr_warn("** NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE **\n"); 2198 pr_warn("** **\n"); 2199 pr_warn("** This system shows unhashed kernel memory addresses **\n"); 2200 pr_warn("** via the console, logs, and other interfaces. This **\n"); 2201 pr_warn("** might reduce the security of your system. **\n"); 2202 pr_warn("** **\n"); 2203 pr_warn("** If you see this message and you are not debugging **\n"); 2204 pr_warn("** the kernel, report this immediately to your system **\n"); 2205 pr_warn("** administrator! **\n"); 2206 pr_warn("** **\n"); 2207 pr_warn("** NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE **\n"); 2208 pr_warn("**********************************************************\n"); 2209 2210 return 0; 2211 } 2212 early_param("no_hash_pointers", no_hash_pointers_enable); 2213 2214 /* 2215 * Show a '%p' thing. A kernel extension is that the '%p' is followed 2216 * by an extra set of alphanumeric characters that are extended format 2217 * specifiers. 2218 * 2219 * Please update scripts/checkpatch.pl when adding/removing conversion 2220 * characters. (Search for "check for vsprintf extension"). 2221 * 2222 * Right now we handle: 2223 * 2224 * - 'S' For symbolic direct pointers (or function descriptors) with offset 2225 * - 's' For symbolic direct pointers (or function descriptors) without offset 2226 * - '[Ss]R' as above with __builtin_extract_return_addr() translation 2227 * - '[Ff]' %pf and %pF were obsoleted and later removed in favor of 2228 * %ps and %pS. Be careful when re-using these specifiers. 2229 * - 'B' For backtraced symbolic direct pointers with offset 2230 * - 'R' For decoded struct resource, e.g., [mem 0x0-0x1f 64bit pref] 2231 * - 'r' For raw struct resource, e.g., [mem 0x0-0x1f flags 0x201] 2232 * - 'b[l]' For a bitmap, the number of bits is determined by the field 2233 * width which must be explicitly specified either as part of the 2234 * format string '%32b[l]' or through '%*b[l]', [l] selects 2235 * range-list format instead of hex format 2236 * - 'M' For a 6-byte MAC address, it prints the address in the 2237 * usual colon-separated hex notation 2238 * - 'm' For a 6-byte MAC address, it prints the hex address without colons 2239 * - 'MF' For a 6-byte MAC FDDI address, it prints the address 2240 * with a dash-separated hex notation 2241 * - '[mM]R' For a 6-byte MAC address, Reverse order (Bluetooth) 2242 * - 'I' [46] for IPv4/IPv6 addresses printed in the usual way 2243 * IPv4 uses dot-separated decimal without leading 0's (1.2.3.4) 2244 * IPv6 uses colon separated network-order 16 bit hex with leading 0's 2245 * [S][pfs] 2246 * Generic IPv4/IPv6 address (struct sockaddr *) that falls back to 2247 * [4] or [6] and is able to print port [p], flowinfo [f], scope [s] 2248 * - 'i' [46] for 'raw' IPv4/IPv6 addresses 2249 * IPv6 omits the colons (01020304...0f) 2250 * IPv4 uses dot-separated decimal with leading 0's (010.123.045.006) 2251 * [S][pfs] 2252 * Generic IPv4/IPv6 address (struct sockaddr *) that falls back to 2253 * [4] or [6] and is able to print port [p], flowinfo [f], scope [s] 2254 * - '[Ii][4S][hnbl]' IPv4 addresses in host, network, big or little endian order 2255 * - 'I[6S]c' for IPv6 addresses printed as specified by 2256 * https://tools.ietf.org/html/rfc5952 2257 * - 'E[achnops]' For an escaped buffer, where rules are defined by combination 2258 * of the following flags (see string_escape_mem() for the 2259 * details): 2260 * a - ESCAPE_ANY 2261 * c - ESCAPE_SPECIAL 2262 * h - ESCAPE_HEX 2263 * n - ESCAPE_NULL 2264 * o - ESCAPE_OCTAL 2265 * p - ESCAPE_NP 2266 * s - ESCAPE_SPACE 2267 * By default ESCAPE_ANY_NP is used. 2268 * - 'U' For a 16 byte UUID/GUID, it prints the UUID/GUID in the form 2269 * "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx" 2270 * Options for %pU are: 2271 * b big endian lower case hex (default) 2272 * B big endian UPPER case hex 2273 * l little endian lower case hex 2274 * L little endian UPPER case hex 2275 * big endian output byte order is: 2276 * [0][1][2][3]-[4][5]-[6][7]-[8][9]-[10][11][12][13][14][15] 2277 * little endian output byte order is: 2278 * [3][2][1][0]-[5][4]-[7][6]-[8][9]-[10][11][12][13][14][15] 2279 * - 'V' For a struct va_format which contains a format string * and va_list *, 2280 * call vsnprintf(->format, *->va_list). 2281 * Implements a "recursive vsnprintf". 2282 * Do not use this feature without some mechanism to verify the 2283 * correctness of the format string and va_list arguments. 2284 * - 'K' For a kernel pointer that should be hidden from unprivileged users. 2285 * Use only for procfs, sysfs and similar files, not printk(); please 2286 * read the documentation (path below) first. 2287 * - 'NF' For a netdev_features_t 2288 * - '4cc' V4L2 or DRM FourCC code, with endianness and raw numerical value. 2289 * - 'h[CDN]' For a variable-length buffer, it prints it as a hex string with 2290 * a certain separator (' ' by default): 2291 * C colon 2292 * D dash 2293 * N no separator 2294 * The maximum supported length is 64 bytes of the input. Consider 2295 * to use print_hex_dump() for the larger input. 2296 * - 'a[pd]' For address types [p] phys_addr_t, [d] dma_addr_t and derivatives 2297 * (default assumed to be phys_addr_t, passed by reference) 2298 * - 'd[234]' For a dentry name (optionally 2-4 last components) 2299 * - 'D[234]' Same as 'd' but for a struct file 2300 * - 'g' For block_device name (gendisk + partition number) 2301 * - 't[RT][dt][r]' For time and date as represented by: 2302 * R struct rtc_time 2303 * T time64_t 2304 * - 'C' For a clock, it prints the name (Common Clock Framework) or address 2305 * (legacy clock framework) of the clock 2306 * - 'Cn' For a clock, it prints the name (Common Clock Framework) or address 2307 * (legacy clock framework) of the clock 2308 * - 'G' For flags to be printed as a collection of symbolic strings that would 2309 * construct the specific value. Supported flags given by option: 2310 * p page flags (see struct page) given as pointer to unsigned long 2311 * g gfp flags (GFP_* and __GFP_*) given as pointer to gfp_t 2312 * v vma flags (VM_*) given as pointer to unsigned long 2313 * - 'OF[fnpPcCF]' For a device tree object 2314 * Without any optional arguments prints the full_name 2315 * f device node full_name 2316 * n device node name 2317 * p device node phandle 2318 * P device node path spec (name + @unit) 2319 * F device node flags 2320 * c major compatible string 2321 * C full compatible string 2322 * - 'fw[fP]' For a firmware node (struct fwnode_handle) pointer 2323 * Without an option prints the full name of the node 2324 * f full name 2325 * P node name, including a possible unit address 2326 * - 'x' For printing the address unmodified. Equivalent to "%lx". 2327 * Please read the documentation (path below) before using! 2328 * - '[ku]s' For a BPF/tracing related format specifier, e.g. used out of 2329 * bpf_trace_printk() where [ku] prefix specifies either kernel (k) 2330 * or user (u) memory to probe, and: 2331 * s a string, equivalent to "%s" on direct vsnprintf() use 2332 * 2333 * ** When making changes please also update: 2334 * Documentation/core-api/printk-formats.rst 2335 * 2336 * Note: The default behaviour (unadorned %p) is to hash the address, 2337 * rendering it useful as a unique identifier. 2338 */ 2339 static noinline_for_stack 2340 char *pointer(const char *fmt, char *buf, char *end, void *ptr, 2341 struct printf_spec spec) 2342 { 2343 switch (*fmt) { 2344 case 'S': 2345 case 's': 2346 ptr = dereference_symbol_descriptor(ptr); 2347 fallthrough; 2348 case 'B': 2349 return symbol_string(buf, end, ptr, spec, fmt); 2350 case 'R': 2351 case 'r': 2352 return resource_string(buf, end, ptr, spec, fmt); 2353 case 'h': 2354 return hex_string(buf, end, ptr, spec, fmt); 2355 case 'b': 2356 switch (fmt[1]) { 2357 case 'l': 2358 return bitmap_list_string(buf, end, ptr, spec, fmt); 2359 default: 2360 return bitmap_string(buf, end, ptr, spec, fmt); 2361 } 2362 case 'M': /* Colon separated: 00:01:02:03:04:05 */ 2363 case 'm': /* Contiguous: 000102030405 */ 2364 /* [mM]F (FDDI) */ 2365 /* [mM]R (Reverse order; Bluetooth) */ 2366 return mac_address_string(buf, end, ptr, spec, fmt); 2367 case 'I': /* Formatted IP supported 2368 * 4: 1.2.3.4 2369 * 6: 0001:0203:...:0708 2370 * 6c: 1::708 or 1::1.2.3.4 2371 */ 2372 case 'i': /* Contiguous: 2373 * 4: 001.002.003.004 2374 * 6: 000102...0f 2375 */ 2376 return ip_addr_string(buf, end, ptr, spec, fmt); 2377 case 'E': 2378 return escaped_string(buf, end, ptr, spec, fmt); 2379 case 'U': 2380 return uuid_string(buf, end, ptr, spec, fmt); 2381 case 'V': 2382 return va_format(buf, end, ptr, spec, fmt); 2383 case 'K': 2384 return restricted_pointer(buf, end, ptr, spec); 2385 case 'N': 2386 return netdev_bits(buf, end, ptr, spec, fmt); 2387 case '4': 2388 return fourcc_string(buf, end, ptr, spec, fmt); 2389 case 'a': 2390 return address_val(buf, end, ptr, spec, fmt); 2391 case 'd': 2392 return dentry_name(buf, end, ptr, spec, fmt); 2393 case 't': 2394 return time_and_date(buf, end, ptr, spec, fmt); 2395 case 'C': 2396 return clock(buf, end, ptr, spec, fmt); 2397 case 'D': 2398 return file_dentry_name(buf, end, ptr, spec, fmt); 2399 #ifdef CONFIG_BLOCK 2400 case 'g': 2401 return bdev_name(buf, end, ptr, spec, fmt); 2402 #endif 2403 2404 case 'G': 2405 return flags_string(buf, end, ptr, spec, fmt); 2406 case 'O': 2407 return device_node_string(buf, end, ptr, spec, fmt + 1); 2408 case 'f': 2409 return fwnode_string(buf, end, ptr, spec, fmt + 1); 2410 case 'x': 2411 return pointer_string(buf, end, ptr, spec); 2412 case 'e': 2413 /* %pe with a non-ERR_PTR gets treated as plain %p */ 2414 if (!IS_ERR(ptr)) 2415 break; 2416 return err_ptr(buf, end, ptr, spec); 2417 case 'u': 2418 case 'k': 2419 switch (fmt[1]) { 2420 case 's': 2421 return string(buf, end, ptr, spec); 2422 default: 2423 return error_string(buf, end, "(einval)", spec); 2424 } 2425 } 2426 2427 /* 2428 * default is to _not_ leak addresses, so hash before printing, 2429 * unless no_hash_pointers is specified on the command line. 2430 */ 2431 if (unlikely(no_hash_pointers)) 2432 return pointer_string(buf, end, ptr, spec); 2433 else 2434 return ptr_to_id(buf, end, ptr, spec); 2435 } 2436 2437 /* 2438 * Helper function to decode printf style format. 2439 * Each call decode a token from the format and return the 2440 * number of characters read (or likely the delta where it wants 2441 * to go on the next call). 2442 * The decoded token is returned through the parameters 2443 * 2444 * 'h', 'l', or 'L' for integer fields 2445 * 'z' support added 23/7/1999 S.H. 2446 * 'z' changed to 'Z' --davidm 1/25/99 2447 * 'Z' changed to 'z' --adobriyan 2017-01-25 2448 * 't' added for ptrdiff_t 2449 * 2450 * @fmt: the format string 2451 * @type of the token returned 2452 * @flags: various flags such as +, -, # tokens.. 2453 * @field_width: overwritten width 2454 * @base: base of the number (octal, hex, ...) 2455 * @precision: precision of a number 2456 * @qualifier: qualifier of a number (long, size_t, ...) 2457 */ 2458 static noinline_for_stack 2459 int format_decode(const char *fmt, struct printf_spec *spec) 2460 { 2461 const char *start = fmt; 2462 char qualifier; 2463 2464 /* we finished early by reading the field width */ 2465 if (spec->type == FORMAT_TYPE_WIDTH) { 2466 if (spec->field_width < 0) { 2467 spec->field_width = -spec->field_width; 2468 spec->flags |= LEFT; 2469 } 2470 spec->type = FORMAT_TYPE_NONE; 2471 goto precision; 2472 } 2473 2474 /* we finished early by reading the precision */ 2475 if (spec->type == FORMAT_TYPE_PRECISION) { 2476 if (spec->precision < 0) 2477 spec->precision = 0; 2478 2479 spec->type = FORMAT_TYPE_NONE; 2480 goto qualifier; 2481 } 2482 2483 /* By default */ 2484 spec->type = FORMAT_TYPE_NONE; 2485 2486 for (; *fmt ; ++fmt) { 2487 if (*fmt == '%') 2488 break; 2489 } 2490 2491 /* Return the current non-format string */ 2492 if (fmt != start || !*fmt) 2493 return fmt - start; 2494 2495 /* Process flags */ 2496 spec->flags = 0; 2497 2498 while (1) { /* this also skips first '%' */ 2499 bool found = true; 2500 2501 ++fmt; 2502 2503 switch (*fmt) { 2504 case '-': spec->flags |= LEFT; break; 2505 case '+': spec->flags |= PLUS; break; 2506 case ' ': spec->flags |= SPACE; break; 2507 case '#': spec->flags |= SPECIAL; break; 2508 case '0': spec->flags |= ZEROPAD; break; 2509 default: found = false; 2510 } 2511 2512 if (!found) 2513 break; 2514 } 2515 2516 /* get field width */ 2517 spec->field_width = -1; 2518 2519 if (isdigit(*fmt)) 2520 spec->field_width = skip_atoi(&fmt); 2521 else if (*fmt == '*') { 2522 /* it's the next argument */ 2523 spec->type = FORMAT_TYPE_WIDTH; 2524 return ++fmt - start; 2525 } 2526 2527 precision: 2528 /* get the precision */ 2529 spec->precision = -1; 2530 if (*fmt == '.') { 2531 ++fmt; 2532 if (isdigit(*fmt)) { 2533 spec->precision = skip_atoi(&fmt); 2534 if (spec->precision < 0) 2535 spec->precision = 0; 2536 } else if (*fmt == '*') { 2537 /* it's the next argument */ 2538 spec->type = FORMAT_TYPE_PRECISION; 2539 return ++fmt - start; 2540 } 2541 } 2542 2543 qualifier: 2544 /* get the conversion qualifier */ 2545 qualifier = 0; 2546 if (*fmt == 'h' || _tolower(*fmt) == 'l' || 2547 *fmt == 'z' || *fmt == 't') { 2548 qualifier = *fmt++; 2549 if (unlikely(qualifier == *fmt)) { 2550 if (qualifier == 'l') { 2551 qualifier = 'L'; 2552 ++fmt; 2553 } else if (qualifier == 'h') { 2554 qualifier = 'H'; 2555 ++fmt; 2556 } 2557 } 2558 } 2559 2560 /* default base */ 2561 spec->base = 10; 2562 switch (*fmt) { 2563 case 'c': 2564 spec->type = FORMAT_TYPE_CHAR; 2565 return ++fmt - start; 2566 2567 case 's': 2568 spec->type = FORMAT_TYPE_STR; 2569 return ++fmt - start; 2570 2571 case 'p': 2572 spec->type = FORMAT_TYPE_PTR; 2573 return ++fmt - start; 2574 2575 case '%': 2576 spec->type = FORMAT_TYPE_PERCENT_CHAR; 2577 return ++fmt - start; 2578 2579 /* integer number formats - set up the flags and "break" */ 2580 case 'o': 2581 spec->base = 8; 2582 break; 2583 2584 case 'x': 2585 spec->flags |= SMALL; 2586 fallthrough; 2587 2588 case 'X': 2589 spec->base = 16; 2590 break; 2591 2592 case 'd': 2593 case 'i': 2594 spec->flags |= SIGN; 2595 break; 2596 case 'u': 2597 break; 2598 2599 case 'n': 2600 /* 2601 * Since %n poses a greater security risk than 2602 * utility, treat it as any other invalid or 2603 * unsupported format specifier. 2604 */ 2605 fallthrough; 2606 2607 default: 2608 WARN_ONCE(1, "Please remove unsupported %%%c in format string\n", *fmt); 2609 spec->type = FORMAT_TYPE_INVALID; 2610 return fmt - start; 2611 } 2612 2613 if (qualifier == 'L') 2614 spec->type = FORMAT_TYPE_LONG_LONG; 2615 else if (qualifier == 'l') { 2616 BUILD_BUG_ON(FORMAT_TYPE_ULONG + SIGN != FORMAT_TYPE_LONG); 2617 spec->type = FORMAT_TYPE_ULONG + (spec->flags & SIGN); 2618 } else if (qualifier == 'z') { 2619 spec->type = FORMAT_TYPE_SIZE_T; 2620 } else if (qualifier == 't') { 2621 spec->type = FORMAT_TYPE_PTRDIFF; 2622 } else if (qualifier == 'H') { 2623 BUILD_BUG_ON(FORMAT_TYPE_UBYTE + SIGN != FORMAT_TYPE_BYTE); 2624 spec->type = FORMAT_TYPE_UBYTE + (spec->flags & SIGN); 2625 } else if (qualifier == 'h') { 2626 BUILD_BUG_ON(FORMAT_TYPE_USHORT + SIGN != FORMAT_TYPE_SHORT); 2627 spec->type = FORMAT_TYPE_USHORT + (spec->flags & SIGN); 2628 } else { 2629 BUILD_BUG_ON(FORMAT_TYPE_UINT + SIGN != FORMAT_TYPE_INT); 2630 spec->type = FORMAT_TYPE_UINT + (spec->flags & SIGN); 2631 } 2632 2633 return ++fmt - start; 2634 } 2635 2636 static void 2637 set_field_width(struct printf_spec *spec, int width) 2638 { 2639 spec->field_width = width; 2640 if (WARN_ONCE(spec->field_width != width, "field width %d too large", width)) { 2641 spec->field_width = clamp(width, -FIELD_WIDTH_MAX, FIELD_WIDTH_MAX); 2642 } 2643 } 2644 2645 static void 2646 set_precision(struct printf_spec *spec, int prec) 2647 { 2648 spec->precision = prec; 2649 if (WARN_ONCE(spec->precision != prec, "precision %d too large", prec)) { 2650 spec->precision = clamp(prec, 0, PRECISION_MAX); 2651 } 2652 } 2653 2654 /** 2655 * vsnprintf - Format a string and place it in a buffer 2656 * @buf: The buffer to place the result into 2657 * @size: The size of the buffer, including the trailing null space 2658 * @fmt: The format string to use 2659 * @args: Arguments for the format string 2660 * 2661 * This function generally follows C99 vsnprintf, but has some 2662 * extensions and a few limitations: 2663 * 2664 * - ``%n`` is unsupported 2665 * - ``%p*`` is handled by pointer() 2666 * 2667 * See pointer() or Documentation/core-api/printk-formats.rst for more 2668 * extensive description. 2669 * 2670 * **Please update the documentation in both places when making changes** 2671 * 2672 * The return value is the number of characters which would 2673 * be generated for the given input, excluding the trailing 2674 * '\0', as per ISO C99. If you want to have the exact 2675 * number of characters written into @buf as return value 2676 * (not including the trailing '\0'), use vscnprintf(). If the 2677 * return is greater than or equal to @size, the resulting 2678 * string is truncated. 2679 * 2680 * If you're not already dealing with a va_list consider using snprintf(). 2681 */ 2682 int vsnprintf(char *buf, size_t size, const char *fmt, va_list args) 2683 { 2684 unsigned long long num; 2685 char *str, *end; 2686 struct printf_spec spec = {0}; 2687 2688 /* Reject out-of-range values early. Large positive sizes are 2689 used for unknown buffer sizes. */ 2690 if (WARN_ON_ONCE(size > INT_MAX)) 2691 return 0; 2692 2693 str = buf; 2694 end = buf + size; 2695 2696 /* Make sure end is always >= buf */ 2697 if (end < buf) { 2698 end = ((void *)-1); 2699 size = end - buf; 2700 } 2701 2702 while (*fmt) { 2703 const char *old_fmt = fmt; 2704 int read = format_decode(fmt, &spec); 2705 2706 fmt += read; 2707 2708 switch (spec.type) { 2709 case FORMAT_TYPE_NONE: { 2710 int copy = read; 2711 if (str < end) { 2712 if (copy > end - str) 2713 copy = end - str; 2714 memcpy(str, old_fmt, copy); 2715 } 2716 str += read; 2717 break; 2718 } 2719 2720 case FORMAT_TYPE_WIDTH: 2721 set_field_width(&spec, va_arg(args, int)); 2722 break; 2723 2724 case FORMAT_TYPE_PRECISION: 2725 set_precision(&spec, va_arg(args, int)); 2726 break; 2727 2728 case FORMAT_TYPE_CHAR: { 2729 char c; 2730 2731 if (!(spec.flags & LEFT)) { 2732 while (--spec.field_width > 0) { 2733 if (str < end) 2734 *str = ' '; 2735 ++str; 2736 2737 } 2738 } 2739 c = (unsigned char) va_arg(args, int); 2740 if (str < end) 2741 *str = c; 2742 ++str; 2743 while (--spec.field_width > 0) { 2744 if (str < end) 2745 *str = ' '; 2746 ++str; 2747 } 2748 break; 2749 } 2750 2751 case FORMAT_TYPE_STR: 2752 str = string(str, end, va_arg(args, char *), spec); 2753 break; 2754 2755 case FORMAT_TYPE_PTR: 2756 str = pointer(fmt, str, end, va_arg(args, void *), 2757 spec); 2758 while (isalnum(*fmt)) 2759 fmt++; 2760 break; 2761 2762 case FORMAT_TYPE_PERCENT_CHAR: 2763 if (str < end) 2764 *str = '%'; 2765 ++str; 2766 break; 2767 2768 case FORMAT_TYPE_INVALID: 2769 /* 2770 * Presumably the arguments passed gcc's type 2771 * checking, but there is no safe or sane way 2772 * for us to continue parsing the format and 2773 * fetching from the va_list; the remaining 2774 * specifiers and arguments would be out of 2775 * sync. 2776 */ 2777 goto out; 2778 2779 default: 2780 switch (spec.type) { 2781 case FORMAT_TYPE_LONG_LONG: 2782 num = va_arg(args, long long); 2783 break; 2784 case FORMAT_TYPE_ULONG: 2785 num = va_arg(args, unsigned long); 2786 break; 2787 case FORMAT_TYPE_LONG: 2788 num = va_arg(args, long); 2789 break; 2790 case FORMAT_TYPE_SIZE_T: 2791 if (spec.flags & SIGN) 2792 num = va_arg(args, ssize_t); 2793 else 2794 num = va_arg(args, size_t); 2795 break; 2796 case FORMAT_TYPE_PTRDIFF: 2797 num = va_arg(args, ptrdiff_t); 2798 break; 2799 case FORMAT_TYPE_UBYTE: 2800 num = (unsigned char) va_arg(args, int); 2801 break; 2802 case FORMAT_TYPE_BYTE: 2803 num = (signed char) va_arg(args, int); 2804 break; 2805 case FORMAT_TYPE_USHORT: 2806 num = (unsigned short) va_arg(args, int); 2807 break; 2808 case FORMAT_TYPE_SHORT: 2809 num = (short) va_arg(args, int); 2810 break; 2811 case FORMAT_TYPE_INT: 2812 num = (int) va_arg(args, int); 2813 break; 2814 default: 2815 num = va_arg(args, unsigned int); 2816 } 2817 2818 str = number(str, end, num, spec); 2819 } 2820 } 2821 2822 out: 2823 if (size > 0) { 2824 if (str < end) 2825 *str = '\0'; 2826 else 2827 end[-1] = '\0'; 2828 } 2829 2830 /* the trailing null byte doesn't count towards the total */ 2831 return str-buf; 2832 2833 } 2834 EXPORT_SYMBOL(vsnprintf); 2835 2836 /** 2837 * vscnprintf - Format a string and place it in a buffer 2838 * @buf: The buffer to place the result into 2839 * @size: The size of the buffer, including the trailing null space 2840 * @fmt: The format string to use 2841 * @args: Arguments for the format string 2842 * 2843 * The return value is the number of characters which have been written into 2844 * the @buf not including the trailing '\0'. If @size is == 0 the function 2845 * returns 0. 2846 * 2847 * If you're not already dealing with a va_list consider using scnprintf(). 2848 * 2849 * See the vsnprintf() documentation for format string extensions over C99. 2850 */ 2851 int vscnprintf(char *buf, size_t size, const char *fmt, va_list args) 2852 { 2853 int i; 2854 2855 i = vsnprintf(buf, size, fmt, args); 2856 2857 if (likely(i < size)) 2858 return i; 2859 if (size != 0) 2860 return size - 1; 2861 return 0; 2862 } 2863 EXPORT_SYMBOL(vscnprintf); 2864 2865 /** 2866 * snprintf - Format a string and place it in a buffer 2867 * @buf: The buffer to place the result into 2868 * @size: The size of the buffer, including the trailing null space 2869 * @fmt: The format string to use 2870 * @...: Arguments for the format string 2871 * 2872 * The return value is the number of characters which would be 2873 * generated for the given input, excluding the trailing null, 2874 * as per ISO C99. If the return is greater than or equal to 2875 * @size, the resulting string is truncated. 2876 * 2877 * See the vsnprintf() documentation for format string extensions over C99. 2878 */ 2879 int snprintf(char *buf, size_t size, const char *fmt, ...) 2880 { 2881 va_list args; 2882 int i; 2883 2884 va_start(args, fmt); 2885 i = vsnprintf(buf, size, fmt, args); 2886 va_end(args); 2887 2888 return i; 2889 } 2890 EXPORT_SYMBOL(snprintf); 2891 2892 /** 2893 * scnprintf - Format a string and place it in a buffer 2894 * @buf: The buffer to place the result into 2895 * @size: The size of the buffer, including the trailing null space 2896 * @fmt: The format string to use 2897 * @...: Arguments for the format string 2898 * 2899 * The return value is the number of characters written into @buf not including 2900 * the trailing '\0'. If @size is == 0 the function returns 0. 2901 */ 2902 2903 int scnprintf(char *buf, size_t size, const char *fmt, ...) 2904 { 2905 va_list args; 2906 int i; 2907 2908 va_start(args, fmt); 2909 i = vscnprintf(buf, size, fmt, args); 2910 va_end(args); 2911 2912 return i; 2913 } 2914 EXPORT_SYMBOL(scnprintf); 2915 2916 /** 2917 * vsprintf - Format a string and place it in a buffer 2918 * @buf: The buffer to place the result into 2919 * @fmt: The format string to use 2920 * @args: Arguments for the format string 2921 * 2922 * The function returns the number of characters written 2923 * into @buf. Use vsnprintf() or vscnprintf() in order to avoid 2924 * buffer overflows. 2925 * 2926 * If you're not already dealing with a va_list consider using sprintf(). 2927 * 2928 * See the vsnprintf() documentation for format string extensions over C99. 2929 */ 2930 int vsprintf(char *buf, const char *fmt, va_list args) 2931 { 2932 return vsnprintf(buf, INT_MAX, fmt, args); 2933 } 2934 EXPORT_SYMBOL(vsprintf); 2935 2936 /** 2937 * sprintf - Format a string and place it in a buffer 2938 * @buf: The buffer to place the result into 2939 * @fmt: The format string to use 2940 * @...: Arguments for the format string 2941 * 2942 * The function returns the number of characters written 2943 * into @buf. Use snprintf() or scnprintf() in order to avoid 2944 * buffer overflows. 2945 * 2946 * See the vsnprintf() documentation for format string extensions over C99. 2947 */ 2948 int sprintf(char *buf, const char *fmt, ...) 2949 { 2950 va_list args; 2951 int i; 2952 2953 va_start(args, fmt); 2954 i = vsnprintf(buf, INT_MAX, fmt, args); 2955 va_end(args); 2956 2957 return i; 2958 } 2959 EXPORT_SYMBOL(sprintf); 2960 2961 #ifdef CONFIG_BINARY_PRINTF 2962 /* 2963 * bprintf service: 2964 * vbin_printf() - VA arguments to binary data 2965 * bstr_printf() - Binary data to text string 2966 */ 2967 2968 /** 2969 * vbin_printf - Parse a format string and place args' binary value in a buffer 2970 * @bin_buf: The buffer to place args' binary value 2971 * @size: The size of the buffer(by words(32bits), not characters) 2972 * @fmt: The format string to use 2973 * @args: Arguments for the format string 2974 * 2975 * The format follows C99 vsnprintf, except %n is ignored, and its argument 2976 * is skipped. 2977 * 2978 * The return value is the number of words(32bits) which would be generated for 2979 * the given input. 2980 * 2981 * NOTE: 2982 * If the return value is greater than @size, the resulting bin_buf is NOT 2983 * valid for bstr_printf(). 2984 */ 2985 int vbin_printf(u32 *bin_buf, size_t size, const char *fmt, va_list args) 2986 { 2987 struct printf_spec spec = {0}; 2988 char *str, *end; 2989 int width; 2990 2991 str = (char *)bin_buf; 2992 end = (char *)(bin_buf + size); 2993 2994 #define save_arg(type) \ 2995 ({ \ 2996 unsigned long long value; \ 2997 if (sizeof(type) == 8) { \ 2998 unsigned long long val8; \ 2999 str = PTR_ALIGN(str, sizeof(u32)); \ 3000 val8 = va_arg(args, unsigned long long); \ 3001 if (str + sizeof(type) <= end) { \ 3002 *(u32 *)str = *(u32 *)&val8; \ 3003 *(u32 *)(str + 4) = *((u32 *)&val8 + 1); \ 3004 } \ 3005 value = val8; \ 3006 } else { \ 3007 unsigned int val4; \ 3008 str = PTR_ALIGN(str, sizeof(type)); \ 3009 val4 = va_arg(args, int); \ 3010 if (str + sizeof(type) <= end) \ 3011 *(typeof(type) *)str = (type)(long)val4; \ 3012 value = (unsigned long long)val4; \ 3013 } \ 3014 str += sizeof(type); \ 3015 value; \ 3016 }) 3017 3018 while (*fmt) { 3019 int read = format_decode(fmt, &spec); 3020 3021 fmt += read; 3022 3023 switch (spec.type) { 3024 case FORMAT_TYPE_NONE: 3025 case FORMAT_TYPE_PERCENT_CHAR: 3026 break; 3027 case FORMAT_TYPE_INVALID: 3028 goto out; 3029 3030 case FORMAT_TYPE_WIDTH: 3031 case FORMAT_TYPE_PRECISION: 3032 width = (int)save_arg(int); 3033 /* Pointers may require the width */ 3034 if (*fmt == 'p') 3035 set_field_width(&spec, width); 3036 break; 3037 3038 case FORMAT_TYPE_CHAR: 3039 save_arg(char); 3040 break; 3041 3042 case FORMAT_TYPE_STR: { 3043 const char *save_str = va_arg(args, char *); 3044 const char *err_msg; 3045 size_t len; 3046 3047 err_msg = check_pointer_msg(save_str); 3048 if (err_msg) 3049 save_str = err_msg; 3050 3051 len = strlen(save_str) + 1; 3052 if (str + len < end) 3053 memcpy(str, save_str, len); 3054 str += len; 3055 break; 3056 } 3057 3058 case FORMAT_TYPE_PTR: 3059 /* Dereferenced pointers must be done now */ 3060 switch (*fmt) { 3061 /* Dereference of functions is still OK */ 3062 case 'S': 3063 case 's': 3064 case 'x': 3065 case 'K': 3066 case 'e': 3067 save_arg(void *); 3068 break; 3069 default: 3070 if (!isalnum(*fmt)) { 3071 save_arg(void *); 3072 break; 3073 } 3074 str = pointer(fmt, str, end, va_arg(args, void *), 3075 spec); 3076 if (str + 1 < end) 3077 *str++ = '\0'; 3078 else 3079 end[-1] = '\0'; /* Must be nul terminated */ 3080 } 3081 /* skip all alphanumeric pointer suffixes */ 3082 while (isalnum(*fmt)) 3083 fmt++; 3084 break; 3085 3086 default: 3087 switch (spec.type) { 3088 3089 case FORMAT_TYPE_LONG_LONG: 3090 save_arg(long long); 3091 break; 3092 case FORMAT_TYPE_ULONG: 3093 case FORMAT_TYPE_LONG: 3094 save_arg(unsigned long); 3095 break; 3096 case FORMAT_TYPE_SIZE_T: 3097 save_arg(size_t); 3098 break; 3099 case FORMAT_TYPE_PTRDIFF: 3100 save_arg(ptrdiff_t); 3101 break; 3102 case FORMAT_TYPE_UBYTE: 3103 case FORMAT_TYPE_BYTE: 3104 save_arg(char); 3105 break; 3106 case FORMAT_TYPE_USHORT: 3107 case FORMAT_TYPE_SHORT: 3108 save_arg(short); 3109 break; 3110 default: 3111 save_arg(int); 3112 } 3113 } 3114 } 3115 3116 out: 3117 return (u32 *)(PTR_ALIGN(str, sizeof(u32))) - bin_buf; 3118 #undef save_arg 3119 } 3120 EXPORT_SYMBOL_GPL(vbin_printf); 3121 3122 /** 3123 * bstr_printf - Format a string from binary arguments and place it in a buffer 3124 * @buf: The buffer to place the result into 3125 * @size: The size of the buffer, including the trailing null space 3126 * @fmt: The format string to use 3127 * @bin_buf: Binary arguments for the format string 3128 * 3129 * This function like C99 vsnprintf, but the difference is that vsnprintf gets 3130 * arguments from stack, and bstr_printf gets arguments from @bin_buf which is 3131 * a binary buffer that generated by vbin_printf. 3132 * 3133 * The format follows C99 vsnprintf, but has some extensions: 3134 * see vsnprintf comment for details. 3135 * 3136 * The return value is the number of characters which would 3137 * be generated for the given input, excluding the trailing 3138 * '\0', as per ISO C99. If you want to have the exact 3139 * number of characters written into @buf as return value 3140 * (not including the trailing '\0'), use vscnprintf(). If the 3141 * return is greater than or equal to @size, the resulting 3142 * string is truncated. 3143 */ 3144 int bstr_printf(char *buf, size_t size, const char *fmt, const u32 *bin_buf) 3145 { 3146 struct printf_spec spec = {0}; 3147 char *str, *end; 3148 const char *args = (const char *)bin_buf; 3149 3150 if (WARN_ON_ONCE(size > INT_MAX)) 3151 return 0; 3152 3153 str = buf; 3154 end = buf + size; 3155 3156 #define get_arg(type) \ 3157 ({ \ 3158 typeof(type) value; \ 3159 if (sizeof(type) == 8) { \ 3160 args = PTR_ALIGN(args, sizeof(u32)); \ 3161 *(u32 *)&value = *(u32 *)args; \ 3162 *((u32 *)&value + 1) = *(u32 *)(args + 4); \ 3163 } else { \ 3164 args = PTR_ALIGN(args, sizeof(type)); \ 3165 value = *(typeof(type) *)args; \ 3166 } \ 3167 args += sizeof(type); \ 3168 value; \ 3169 }) 3170 3171 /* Make sure end is always >= buf */ 3172 if (end < buf) { 3173 end = ((void *)-1); 3174 size = end - buf; 3175 } 3176 3177 while (*fmt) { 3178 const char *old_fmt = fmt; 3179 int read = format_decode(fmt, &spec); 3180 3181 fmt += read; 3182 3183 switch (spec.type) { 3184 case FORMAT_TYPE_NONE: { 3185 int copy = read; 3186 if (str < end) { 3187 if (copy > end - str) 3188 copy = end - str; 3189 memcpy(str, old_fmt, copy); 3190 } 3191 str += read; 3192 break; 3193 } 3194 3195 case FORMAT_TYPE_WIDTH: 3196 set_field_width(&spec, get_arg(int)); 3197 break; 3198 3199 case FORMAT_TYPE_PRECISION: 3200 set_precision(&spec, get_arg(int)); 3201 break; 3202 3203 case FORMAT_TYPE_CHAR: { 3204 char c; 3205 3206 if (!(spec.flags & LEFT)) { 3207 while (--spec.field_width > 0) { 3208 if (str < end) 3209 *str = ' '; 3210 ++str; 3211 } 3212 } 3213 c = (unsigned char) get_arg(char); 3214 if (str < end) 3215 *str = c; 3216 ++str; 3217 while (--spec.field_width > 0) { 3218 if (str < end) 3219 *str = ' '; 3220 ++str; 3221 } 3222 break; 3223 } 3224 3225 case FORMAT_TYPE_STR: { 3226 const char *str_arg = args; 3227 args += strlen(str_arg) + 1; 3228 str = string(str, end, (char *)str_arg, spec); 3229 break; 3230 } 3231 3232 case FORMAT_TYPE_PTR: { 3233 bool process = false; 3234 int copy, len; 3235 /* Non function dereferences were already done */ 3236 switch (*fmt) { 3237 case 'S': 3238 case 's': 3239 case 'x': 3240 case 'K': 3241 case 'e': 3242 process = true; 3243 break; 3244 default: 3245 if (!isalnum(*fmt)) { 3246 process = true; 3247 break; 3248 } 3249 /* Pointer dereference was already processed */ 3250 if (str < end) { 3251 len = copy = strlen(args); 3252 if (copy > end - str) 3253 copy = end - str; 3254 memcpy(str, args, copy); 3255 str += len; 3256 args += len + 1; 3257 } 3258 } 3259 if (process) 3260 str = pointer(fmt, str, end, get_arg(void *), spec); 3261 3262 while (isalnum(*fmt)) 3263 fmt++; 3264 break; 3265 } 3266 3267 case FORMAT_TYPE_PERCENT_CHAR: 3268 if (str < end) 3269 *str = '%'; 3270 ++str; 3271 break; 3272 3273 case FORMAT_TYPE_INVALID: 3274 goto out; 3275 3276 default: { 3277 unsigned long long num; 3278 3279 switch (spec.type) { 3280 3281 case FORMAT_TYPE_LONG_LONG: 3282 num = get_arg(long long); 3283 break; 3284 case FORMAT_TYPE_ULONG: 3285 case FORMAT_TYPE_LONG: 3286 num = get_arg(unsigned long); 3287 break; 3288 case FORMAT_TYPE_SIZE_T: 3289 num = get_arg(size_t); 3290 break; 3291 case FORMAT_TYPE_PTRDIFF: 3292 num = get_arg(ptrdiff_t); 3293 break; 3294 case FORMAT_TYPE_UBYTE: 3295 num = get_arg(unsigned char); 3296 break; 3297 case FORMAT_TYPE_BYTE: 3298 num = get_arg(signed char); 3299 break; 3300 case FORMAT_TYPE_USHORT: 3301 num = get_arg(unsigned short); 3302 break; 3303 case FORMAT_TYPE_SHORT: 3304 num = get_arg(short); 3305 break; 3306 case FORMAT_TYPE_UINT: 3307 num = get_arg(unsigned int); 3308 break; 3309 default: 3310 num = get_arg(int); 3311 } 3312 3313 str = number(str, end, num, spec); 3314 } /* default: */ 3315 } /* switch(spec.type) */ 3316 } /* while(*fmt) */ 3317 3318 out: 3319 if (size > 0) { 3320 if (str < end) 3321 *str = '\0'; 3322 else 3323 end[-1] = '\0'; 3324 } 3325 3326 #undef get_arg 3327 3328 /* the trailing null byte doesn't count towards the total */ 3329 return str - buf; 3330 } 3331 EXPORT_SYMBOL_GPL(bstr_printf); 3332 3333 /** 3334 * bprintf - Parse a format string and place args' binary value in a buffer 3335 * @bin_buf: The buffer to place args' binary value 3336 * @size: The size of the buffer(by words(32bits), not characters) 3337 * @fmt: The format string to use 3338 * @...: Arguments for the format string 3339 * 3340 * The function returns the number of words(u32) written 3341 * into @bin_buf. 3342 */ 3343 int bprintf(u32 *bin_buf, size_t size, const char *fmt, ...) 3344 { 3345 va_list args; 3346 int ret; 3347 3348 va_start(args, fmt); 3349 ret = vbin_printf(bin_buf, size, fmt, args); 3350 va_end(args); 3351 3352 return ret; 3353 } 3354 EXPORT_SYMBOL_GPL(bprintf); 3355 3356 #endif /* CONFIG_BINARY_PRINTF */ 3357 3358 /** 3359 * vsscanf - Unformat a buffer into a list of arguments 3360 * @buf: input buffer 3361 * @fmt: format of buffer 3362 * @args: arguments 3363 */ 3364 int vsscanf(const char *buf, const char *fmt, va_list args) 3365 { 3366 const char *str = buf; 3367 char *next; 3368 char digit; 3369 int num = 0; 3370 u8 qualifier; 3371 unsigned int base; 3372 union { 3373 long long s; 3374 unsigned long long u; 3375 } val; 3376 s16 field_width; 3377 bool is_sign; 3378 3379 while (*fmt) { 3380 /* skip any white space in format */ 3381 /* white space in format matchs any amount of 3382 * white space, including none, in the input. 3383 */ 3384 if (isspace(*fmt)) { 3385 fmt = skip_spaces(++fmt); 3386 str = skip_spaces(str); 3387 } 3388 3389 /* anything that is not a conversion must match exactly */ 3390 if (*fmt != '%' && *fmt) { 3391 if (*fmt++ != *str++) 3392 break; 3393 continue; 3394 } 3395 3396 if (!*fmt) 3397 break; 3398 ++fmt; 3399 3400 /* skip this conversion. 3401 * advance both strings to next white space 3402 */ 3403 if (*fmt == '*') { 3404 if (!*str) 3405 break; 3406 while (!isspace(*fmt) && *fmt != '%' && *fmt) { 3407 /* '%*[' not yet supported, invalid format */ 3408 if (*fmt == '[') 3409 return num; 3410 fmt++; 3411 } 3412 while (!isspace(*str) && *str) 3413 str++; 3414 continue; 3415 } 3416 3417 /* get field width */ 3418 field_width = -1; 3419 if (isdigit(*fmt)) { 3420 field_width = skip_atoi(&fmt); 3421 if (field_width <= 0) 3422 break; 3423 } 3424 3425 /* get conversion qualifier */ 3426 qualifier = -1; 3427 if (*fmt == 'h' || _tolower(*fmt) == 'l' || 3428 *fmt == 'z') { 3429 qualifier = *fmt++; 3430 if (unlikely(qualifier == *fmt)) { 3431 if (qualifier == 'h') { 3432 qualifier = 'H'; 3433 fmt++; 3434 } else if (qualifier == 'l') { 3435 qualifier = 'L'; 3436 fmt++; 3437 } 3438 } 3439 } 3440 3441 if (!*fmt) 3442 break; 3443 3444 if (*fmt == 'n') { 3445 /* return number of characters read so far */ 3446 *va_arg(args, int *) = str - buf; 3447 ++fmt; 3448 continue; 3449 } 3450 3451 if (!*str) 3452 break; 3453 3454 base = 10; 3455 is_sign = false; 3456 3457 switch (*fmt++) { 3458 case 'c': 3459 { 3460 char *s = (char *)va_arg(args, char*); 3461 if (field_width == -1) 3462 field_width = 1; 3463 do { 3464 *s++ = *str++; 3465 } while (--field_width > 0 && *str); 3466 num++; 3467 } 3468 continue; 3469 case 's': 3470 { 3471 char *s = (char *)va_arg(args, char *); 3472 if (field_width == -1) 3473 field_width = SHRT_MAX; 3474 /* first, skip leading white space in buffer */ 3475 str = skip_spaces(str); 3476 3477 /* now copy until next white space */ 3478 while (*str && !isspace(*str) && field_width--) 3479 *s++ = *str++; 3480 *s = '\0'; 3481 num++; 3482 } 3483 continue; 3484 /* 3485 * Warning: This implementation of the '[' conversion specifier 3486 * deviates from its glibc counterpart in the following ways: 3487 * (1) It does NOT support ranges i.e. '-' is NOT a special 3488 * character 3489 * (2) It cannot match the closing bracket ']' itself 3490 * (3) A field width is required 3491 * (4) '%*[' (discard matching input) is currently not supported 3492 * 3493 * Example usage: 3494 * ret = sscanf("00:0a:95","%2[^:]:%2[^:]:%2[^:]", 3495 * buf1, buf2, buf3); 3496 * if (ret < 3) 3497 * // etc.. 3498 */ 3499 case '[': 3500 { 3501 char *s = (char *)va_arg(args, char *); 3502 DECLARE_BITMAP(set, 256) = {0}; 3503 unsigned int len = 0; 3504 bool negate = (*fmt == '^'); 3505 3506 /* field width is required */ 3507 if (field_width == -1) 3508 return num; 3509 3510 if (negate) 3511 ++fmt; 3512 3513 for ( ; *fmt && *fmt != ']'; ++fmt, ++len) 3514 set_bit((u8)*fmt, set); 3515 3516 /* no ']' or no character set found */ 3517 if (!*fmt || !len) 3518 return num; 3519 ++fmt; 3520 3521 if (negate) { 3522 bitmap_complement(set, set, 256); 3523 /* exclude null '\0' byte */ 3524 clear_bit(0, set); 3525 } 3526 3527 /* match must be non-empty */ 3528 if (!test_bit((u8)*str, set)) 3529 return num; 3530 3531 while (test_bit((u8)*str, set) && field_width--) 3532 *s++ = *str++; 3533 *s = '\0'; 3534 ++num; 3535 } 3536 continue; 3537 case 'o': 3538 base = 8; 3539 break; 3540 case 'x': 3541 case 'X': 3542 base = 16; 3543 break; 3544 case 'i': 3545 base = 0; 3546 fallthrough; 3547 case 'd': 3548 is_sign = true; 3549 fallthrough; 3550 case 'u': 3551 break; 3552 case '%': 3553 /* looking for '%' in str */ 3554 if (*str++ != '%') 3555 return num; 3556 continue; 3557 default: 3558 /* invalid format; stop here */ 3559 return num; 3560 } 3561 3562 /* have some sort of integer conversion. 3563 * first, skip white space in buffer. 3564 */ 3565 str = skip_spaces(str); 3566 3567 digit = *str; 3568 if (is_sign && digit == '-') 3569 digit = *(str + 1); 3570 3571 if (!digit 3572 || (base == 16 && !isxdigit(digit)) 3573 || (base == 10 && !isdigit(digit)) 3574 || (base == 8 && (!isdigit(digit) || digit > '7')) 3575 || (base == 0 && !isdigit(digit))) 3576 break; 3577 3578 if (is_sign) 3579 val.s = qualifier != 'L' ? 3580 simple_strtol(str, &next, base) : 3581 simple_strtoll(str, &next, base); 3582 else 3583 val.u = qualifier != 'L' ? 3584 simple_strtoul(str, &next, base) : 3585 simple_strtoull(str, &next, base); 3586 3587 if (field_width > 0 && next - str > field_width) { 3588 if (base == 0) 3589 _parse_integer_fixup_radix(str, &base); 3590 while (next - str > field_width) { 3591 if (is_sign) 3592 val.s = div_s64(val.s, base); 3593 else 3594 val.u = div_u64(val.u, base); 3595 --next; 3596 } 3597 } 3598 3599 switch (qualifier) { 3600 case 'H': /* that's 'hh' in format */ 3601 if (is_sign) 3602 *va_arg(args, signed char *) = val.s; 3603 else 3604 *va_arg(args, unsigned char *) = val.u; 3605 break; 3606 case 'h': 3607 if (is_sign) 3608 *va_arg(args, short *) = val.s; 3609 else 3610 *va_arg(args, unsigned short *) = val.u; 3611 break; 3612 case 'l': 3613 if (is_sign) 3614 *va_arg(args, long *) = val.s; 3615 else 3616 *va_arg(args, unsigned long *) = val.u; 3617 break; 3618 case 'L': 3619 if (is_sign) 3620 *va_arg(args, long long *) = val.s; 3621 else 3622 *va_arg(args, unsigned long long *) = val.u; 3623 break; 3624 case 'z': 3625 *va_arg(args, size_t *) = val.u; 3626 break; 3627 default: 3628 if (is_sign) 3629 *va_arg(args, int *) = val.s; 3630 else 3631 *va_arg(args, unsigned int *) = val.u; 3632 break; 3633 } 3634 num++; 3635 3636 if (!next) 3637 break; 3638 str = next; 3639 } 3640 3641 return num; 3642 } 3643 EXPORT_SYMBOL(vsscanf); 3644 3645 /** 3646 * sscanf - Unformat a buffer into a list of arguments 3647 * @buf: input buffer 3648 * @fmt: formatting of buffer 3649 * @...: resulting arguments 3650 */ 3651 int sscanf(const char *buf, const char *fmt, ...) 3652 { 3653 va_list args; 3654 int i; 3655 3656 va_start(args, fmt); 3657 i = vsscanf(buf, fmt, args); 3658 va_end(args); 3659 3660 return i; 3661 } 3662 EXPORT_SYMBOL(sscanf); 3663