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 <[email protected]> 15 * - changed to provide snprintf and vsnprintf functions 16 * So Feb 1 16:51:32 CET 2004 Juergen Quade <[email protected]> 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 static unsigned long long simple_strntoull(const char *startp, size_t max_chars, 57 char **endp, unsigned int base) 58 { 59 const char *cp; 60 unsigned long long result = 0ULL; 61 size_t prefix_chars; 62 unsigned int rv; 63 64 cp = _parse_integer_fixup_radix(startp, &base); 65 prefix_chars = cp - startp; 66 if (prefix_chars < max_chars) { 67 rv = _parse_integer_limit(cp, base, &result, max_chars - prefix_chars); 68 /* FIXME */ 69 cp += (rv & ~KSTRTOX_OVERFLOW); 70 } else { 71 /* Field too short for prefix + digit, skip over without converting */ 72 cp = startp + max_chars; 73 } 74 75 if (endp) 76 *endp = (char *)cp; 77 78 return result; 79 } 80 81 /** 82 * simple_strtoull - convert a string to an unsigned long long 83 * @cp: The start of the string 84 * @endp: A pointer to the end of the parsed string will be placed here 85 * @base: The number base to use 86 * 87 * This function has caveats. Please use kstrtoull instead. 88 */ 89 unsigned long long simple_strtoull(const char *cp, char **endp, unsigned int base) 90 { 91 return simple_strntoull(cp, INT_MAX, endp, base); 92 } 93 EXPORT_SYMBOL(simple_strtoull); 94 95 /** 96 * simple_strtoul - convert a string to an unsigned long 97 * @cp: The start of the string 98 * @endp: A pointer to the end of the parsed string will be placed here 99 * @base: The number base to use 100 * 101 * This function has caveats. Please use kstrtoul instead. 102 */ 103 unsigned long simple_strtoul(const char *cp, char **endp, unsigned int base) 104 { 105 return simple_strtoull(cp, endp, base); 106 } 107 EXPORT_SYMBOL(simple_strtoul); 108 109 /** 110 * simple_strtol - convert a string to a signed long 111 * @cp: The start of the string 112 * @endp: A pointer to the end of the parsed string will be placed here 113 * @base: The number base to use 114 * 115 * This function has caveats. Please use kstrtol instead. 116 */ 117 long simple_strtol(const char *cp, char **endp, unsigned int base) 118 { 119 if (*cp == '-') 120 return -simple_strtoul(cp + 1, endp, base); 121 122 return simple_strtoul(cp, endp, base); 123 } 124 EXPORT_SYMBOL(simple_strtol); 125 126 static long long simple_strntoll(const char *cp, size_t max_chars, char **endp, 127 unsigned int base) 128 { 129 /* 130 * simple_strntoull() safely handles receiving max_chars==0 in the 131 * case cp[0] == '-' && max_chars == 1. 132 * If max_chars == 0 we can drop through and pass it to simple_strntoull() 133 * and the content of *cp is irrelevant. 134 */ 135 if (*cp == '-' && max_chars > 0) 136 return -simple_strntoull(cp + 1, max_chars - 1, endp, base); 137 138 return simple_strntoull(cp, max_chars, endp, base); 139 } 140 141 /** 142 * simple_strtoll - convert a string to a signed long long 143 * @cp: The start of the string 144 * @endp: A pointer to the end of the parsed string will be placed here 145 * @base: The number base to use 146 * 147 * This function has caveats. Please use kstrtoll instead. 148 */ 149 long long simple_strtoll(const char *cp, char **endp, unsigned int base) 150 { 151 return simple_strntoll(cp, INT_MAX, endp, base); 152 } 153 EXPORT_SYMBOL(simple_strtoll); 154 155 static noinline_for_stack 156 int skip_atoi(const char **s) 157 { 158 int i = 0; 159 160 do { 161 i = i*10 + *((*s)++) - '0'; 162 } while (isdigit(**s)); 163 164 return i; 165 } 166 167 /* 168 * Decimal conversion is by far the most typical, and is used for 169 * /proc and /sys data. This directly impacts e.g. top performance 170 * with many processes running. We optimize it for speed by emitting 171 * two characters at a time, using a 200 byte lookup table. This 172 * roughly halves the number of multiplications compared to computing 173 * the digits one at a time. Implementation strongly inspired by the 174 * previous version, which in turn used ideas described at 175 * <http://www.cs.uiowa.edu/~jones/bcd/divide.html> (with permission 176 * from the author, Douglas W. Jones). 177 * 178 * It turns out there is precisely one 26 bit fixed-point 179 * approximation a of 64/100 for which x/100 == (x * (u64)a) >> 32 180 * holds for all x in [0, 10^8-1], namely a = 0x28f5c29. The actual 181 * range happens to be somewhat larger (x <= 1073741898), but that's 182 * irrelevant for our purpose. 183 * 184 * For dividing a number in the range [10^4, 10^6-1] by 100, we still 185 * need a 32x32->64 bit multiply, so we simply use the same constant. 186 * 187 * For dividing a number in the range [100, 10^4-1] by 100, there are 188 * several options. The simplest is (x * 0x147b) >> 19, which is valid 189 * for all x <= 43698. 190 */ 191 192 static const u16 decpair[100] = { 193 #define _(x) (__force u16) cpu_to_le16(((x % 10) | ((x / 10) << 8)) + 0x3030) 194 _( 0), _( 1), _( 2), _( 3), _( 4), _( 5), _( 6), _( 7), _( 8), _( 9), 195 _(10), _(11), _(12), _(13), _(14), _(15), _(16), _(17), _(18), _(19), 196 _(20), _(21), _(22), _(23), _(24), _(25), _(26), _(27), _(28), _(29), 197 _(30), _(31), _(32), _(33), _(34), _(35), _(36), _(37), _(38), _(39), 198 _(40), _(41), _(42), _(43), _(44), _(45), _(46), _(47), _(48), _(49), 199 _(50), _(51), _(52), _(53), _(54), _(55), _(56), _(57), _(58), _(59), 200 _(60), _(61), _(62), _(63), _(64), _(65), _(66), _(67), _(68), _(69), 201 _(70), _(71), _(72), _(73), _(74), _(75), _(76), _(77), _(78), _(79), 202 _(80), _(81), _(82), _(83), _(84), _(85), _(86), _(87), _(88), _(89), 203 _(90), _(91), _(92), _(93), _(94), _(95), _(96), _(97), _(98), _(99), 204 #undef _ 205 }; 206 207 /* 208 * This will print a single '0' even if r == 0, since we would 209 * immediately jump to out_r where two 0s would be written but only 210 * one of them accounted for in buf. This is needed by ip4_string 211 * below. All other callers pass a non-zero value of r. 212 */ 213 static noinline_for_stack 214 char *put_dec_trunc8(char *buf, unsigned r) 215 { 216 unsigned q; 217 218 /* 1 <= r < 10^8 */ 219 if (r < 100) 220 goto out_r; 221 222 /* 100 <= r < 10^8 */ 223 q = (r * (u64)0x28f5c29) >> 32; 224 *((u16 *)buf) = decpair[r - 100*q]; 225 buf += 2; 226 227 /* 1 <= q < 10^6 */ 228 if (q < 100) 229 goto out_q; 230 231 /* 100 <= q < 10^6 */ 232 r = (q * (u64)0x28f5c29) >> 32; 233 *((u16 *)buf) = decpair[q - 100*r]; 234 buf += 2; 235 236 /* 1 <= r < 10^4 */ 237 if (r < 100) 238 goto out_r; 239 240 /* 100 <= r < 10^4 */ 241 q = (r * 0x147b) >> 19; 242 *((u16 *)buf) = decpair[r - 100*q]; 243 buf += 2; 244 out_q: 245 /* 1 <= q < 100 */ 246 r = q; 247 out_r: 248 /* 1 <= r < 100 */ 249 *((u16 *)buf) = decpair[r]; 250 buf += r < 10 ? 1 : 2; 251 return buf; 252 } 253 254 #if BITS_PER_LONG == 64 && BITS_PER_LONG_LONG == 64 255 static noinline_for_stack 256 char *put_dec_full8(char *buf, unsigned r) 257 { 258 unsigned q; 259 260 /* 0 <= r < 10^8 */ 261 q = (r * (u64)0x28f5c29) >> 32; 262 *((u16 *)buf) = decpair[r - 100*q]; 263 buf += 2; 264 265 /* 0 <= q < 10^6 */ 266 r = (q * (u64)0x28f5c29) >> 32; 267 *((u16 *)buf) = decpair[q - 100*r]; 268 buf += 2; 269 270 /* 0 <= r < 10^4 */ 271 q = (r * 0x147b) >> 19; 272 *((u16 *)buf) = decpair[r - 100*q]; 273 buf += 2; 274 275 /* 0 <= q < 100 */ 276 *((u16 *)buf) = decpair[q]; 277 buf += 2; 278 return buf; 279 } 280 281 static noinline_for_stack 282 char *put_dec(char *buf, unsigned long long n) 283 { 284 if (n >= 100*1000*1000) 285 buf = put_dec_full8(buf, do_div(n, 100*1000*1000)); 286 /* 1 <= n <= 1.6e11 */ 287 if (n >= 100*1000*1000) 288 buf = put_dec_full8(buf, do_div(n, 100*1000*1000)); 289 /* 1 <= n < 1e8 */ 290 return put_dec_trunc8(buf, n); 291 } 292 293 #elif BITS_PER_LONG == 32 && BITS_PER_LONG_LONG == 64 294 295 static void 296 put_dec_full4(char *buf, unsigned r) 297 { 298 unsigned q; 299 300 /* 0 <= r < 10^4 */ 301 q = (r * 0x147b) >> 19; 302 *((u16 *)buf) = decpair[r - 100*q]; 303 buf += 2; 304 /* 0 <= q < 100 */ 305 *((u16 *)buf) = decpair[q]; 306 } 307 308 /* 309 * Call put_dec_full4 on x % 10000, return x / 10000. 310 * The approximation x/10000 == (x * 0x346DC5D7) >> 43 311 * holds for all x < 1,128,869,999. The largest value this 312 * helper will ever be asked to convert is 1,125,520,955. 313 * (second call in the put_dec code, assuming n is all-ones). 314 */ 315 static noinline_for_stack 316 unsigned put_dec_helper4(char *buf, unsigned x) 317 { 318 uint32_t q = (x * (uint64_t)0x346DC5D7) >> 43; 319 320 put_dec_full4(buf, x - q * 10000); 321 return q; 322 } 323 324 /* Based on code by Douglas W. Jones found at 325 * <http://www.cs.uiowa.edu/~jones/bcd/decimal.html#sixtyfour> 326 * (with permission from the author). 327 * Performs no 64-bit division and hence should be fast on 32-bit machines. 328 */ 329 static 330 char *put_dec(char *buf, unsigned long long n) 331 { 332 uint32_t d3, d2, d1, q, h; 333 334 if (n < 100*1000*1000) 335 return put_dec_trunc8(buf, n); 336 337 d1 = ((uint32_t)n >> 16); /* implicit "& 0xffff" */ 338 h = (n >> 32); 339 d2 = (h ) & 0xffff; 340 d3 = (h >> 16); /* implicit "& 0xffff" */ 341 342 /* n = 2^48 d3 + 2^32 d2 + 2^16 d1 + d0 343 = 281_4749_7671_0656 d3 + 42_9496_7296 d2 + 6_5536 d1 + d0 */ 344 q = 656 * d3 + 7296 * d2 + 5536 * d1 + ((uint32_t)n & 0xffff); 345 q = put_dec_helper4(buf, q); 346 347 q += 7671 * d3 + 9496 * d2 + 6 * d1; 348 q = put_dec_helper4(buf+4, q); 349 350 q += 4749 * d3 + 42 * d2; 351 q = put_dec_helper4(buf+8, q); 352 353 q += 281 * d3; 354 buf += 12; 355 if (q) 356 buf = put_dec_trunc8(buf, q); 357 else while (buf[-1] == '0') 358 --buf; 359 360 return buf; 361 } 362 363 #endif 364 365 /* 366 * Convert passed number to decimal string. 367 * Returns the length of string. On buffer overflow, returns 0. 368 * 369 * If speed is not important, use snprintf(). It's easy to read the code. 370 */ 371 int num_to_str(char *buf, int size, unsigned long long num, unsigned int width) 372 { 373 /* put_dec requires 2-byte alignment of the buffer. */ 374 char tmp[sizeof(num) * 3] __aligned(2); 375 int idx, len; 376 377 /* put_dec() may work incorrectly for num = 0 (generate "", not "0") */ 378 if (num <= 9) { 379 tmp[0] = '0' + num; 380 len = 1; 381 } else { 382 len = put_dec(tmp, num) - tmp; 383 } 384 385 if (len > size || width > size) 386 return 0; 387 388 if (width > len) { 389 width = width - len; 390 for (idx = 0; idx < width; idx++) 391 buf[idx] = ' '; 392 } else { 393 width = 0; 394 } 395 396 for (idx = 0; idx < len; ++idx) 397 buf[idx + width] = tmp[len - idx - 1]; 398 399 return len + width; 400 } 401 402 #define SIGN 1 /* unsigned/signed, must be 1 */ 403 #define LEFT 2 /* left justified */ 404 #define PLUS 4 /* show plus */ 405 #define SPACE 8 /* space if plus */ 406 #define ZEROPAD 16 /* pad with zero, must be 16 == '0' - ' ' */ 407 #define SMALL 32 /* use lowercase in hex (must be 32 == 0x20) */ 408 #define SPECIAL 64 /* prefix hex with "0x", octal with "0" */ 409 410 static_assert(ZEROPAD == ('0' - ' ')); 411 static_assert(SMALL == ' '); 412 413 enum format_type { 414 FORMAT_TYPE_NONE, /* Just a string part */ 415 FORMAT_TYPE_WIDTH, 416 FORMAT_TYPE_PRECISION, 417 FORMAT_TYPE_CHAR, 418 FORMAT_TYPE_STR, 419 FORMAT_TYPE_PTR, 420 FORMAT_TYPE_PERCENT_CHAR, 421 FORMAT_TYPE_INVALID, 422 FORMAT_TYPE_LONG_LONG, 423 FORMAT_TYPE_ULONG, 424 FORMAT_TYPE_LONG, 425 FORMAT_TYPE_UBYTE, 426 FORMAT_TYPE_BYTE, 427 FORMAT_TYPE_USHORT, 428 FORMAT_TYPE_SHORT, 429 FORMAT_TYPE_UINT, 430 FORMAT_TYPE_INT, 431 FORMAT_TYPE_SIZE_T, 432 FORMAT_TYPE_PTRDIFF 433 }; 434 435 struct printf_spec { 436 unsigned int type:8; /* format_type enum */ 437 signed int field_width:24; /* width of output field */ 438 unsigned int flags:8; /* flags to number() */ 439 unsigned int base:8; /* number base, 8, 10 or 16 only */ 440 signed int precision:16; /* # of digits/chars */ 441 } __packed; 442 static_assert(sizeof(struct printf_spec) == 8); 443 444 #define FIELD_WIDTH_MAX ((1 << 23) - 1) 445 #define PRECISION_MAX ((1 << 15) - 1) 446 447 static noinline_for_stack 448 char *number(char *buf, char *end, unsigned long long num, 449 struct printf_spec spec) 450 { 451 /* put_dec requires 2-byte alignment of the buffer. */ 452 char tmp[3 * sizeof(num)] __aligned(2); 453 char sign; 454 char locase; 455 int need_pfx = ((spec.flags & SPECIAL) && spec.base != 10); 456 int i; 457 bool is_zero = num == 0LL; 458 int field_width = spec.field_width; 459 int precision = spec.precision; 460 461 /* locase = 0 or 0x20. ORing digits or letters with 'locase' 462 * produces same digits or (maybe lowercased) letters */ 463 locase = (spec.flags & SMALL); 464 if (spec.flags & LEFT) 465 spec.flags &= ~ZEROPAD; 466 sign = 0; 467 if (spec.flags & SIGN) { 468 if ((signed long long)num < 0) { 469 sign = '-'; 470 num = -(signed long long)num; 471 field_width--; 472 } else if (spec.flags & PLUS) { 473 sign = '+'; 474 field_width--; 475 } else if (spec.flags & SPACE) { 476 sign = ' '; 477 field_width--; 478 } 479 } 480 if (need_pfx) { 481 if (spec.base == 16) 482 field_width -= 2; 483 else if (!is_zero) 484 field_width--; 485 } 486 487 /* generate full string in tmp[], in reverse order */ 488 i = 0; 489 if (num < spec.base) 490 tmp[i++] = hex_asc_upper[num] | locase; 491 else if (spec.base != 10) { /* 8 or 16 */ 492 int mask = spec.base - 1; 493 int shift = 3; 494 495 if (spec.base == 16) 496 shift = 4; 497 do { 498 tmp[i++] = (hex_asc_upper[((unsigned char)num) & mask] | locase); 499 num >>= shift; 500 } while (num); 501 } else { /* base 10 */ 502 i = put_dec(tmp, num) - tmp; 503 } 504 505 /* printing 100 using %2d gives "100", not "00" */ 506 if (i > precision) 507 precision = i; 508 /* leading space padding */ 509 field_width -= precision; 510 if (!(spec.flags & (ZEROPAD | LEFT))) { 511 while (--field_width >= 0) { 512 if (buf < end) 513 *buf = ' '; 514 ++buf; 515 } 516 } 517 /* sign */ 518 if (sign) { 519 if (buf < end) 520 *buf = sign; 521 ++buf; 522 } 523 /* "0x" / "0" prefix */ 524 if (need_pfx) { 525 if (spec.base == 16 || !is_zero) { 526 if (buf < end) 527 *buf = '0'; 528 ++buf; 529 } 530 if (spec.base == 16) { 531 if (buf < end) 532 *buf = ('X' | locase); 533 ++buf; 534 } 535 } 536 /* zero or space padding */ 537 if (!(spec.flags & LEFT)) { 538 char c = ' ' + (spec.flags & ZEROPAD); 539 540 while (--field_width >= 0) { 541 if (buf < end) 542 *buf = c; 543 ++buf; 544 } 545 } 546 /* hmm even more zero padding? */ 547 while (i <= --precision) { 548 if (buf < end) 549 *buf = '0'; 550 ++buf; 551 } 552 /* actual digits of result */ 553 while (--i >= 0) { 554 if (buf < end) 555 *buf = tmp[i]; 556 ++buf; 557 } 558 /* trailing space padding */ 559 while (--field_width >= 0) { 560 if (buf < end) 561 *buf = ' '; 562 ++buf; 563 } 564 565 return buf; 566 } 567 568 static noinline_for_stack 569 char *special_hex_number(char *buf, char *end, unsigned long long num, int size) 570 { 571 struct printf_spec spec; 572 573 spec.type = FORMAT_TYPE_PTR; 574 spec.field_width = 2 + 2 * size; /* 0x + hex */ 575 spec.flags = SPECIAL | SMALL | ZEROPAD; 576 spec.base = 16; 577 spec.precision = -1; 578 579 return number(buf, end, num, spec); 580 } 581 582 static void move_right(char *buf, char *end, unsigned len, unsigned spaces) 583 { 584 size_t size; 585 if (buf >= end) /* nowhere to put anything */ 586 return; 587 size = end - buf; 588 if (size <= spaces) { 589 memset(buf, ' ', size); 590 return; 591 } 592 if (len) { 593 if (len > size - spaces) 594 len = size - spaces; 595 memmove(buf + spaces, buf, len); 596 } 597 memset(buf, ' ', spaces); 598 } 599 600 /* 601 * Handle field width padding for a string. 602 * @buf: current buffer position 603 * @n: length of string 604 * @end: end of output buffer 605 * @spec: for field width and flags 606 * Returns: new buffer position after padding. 607 */ 608 static noinline_for_stack 609 char *widen_string(char *buf, int n, char *end, struct printf_spec spec) 610 { 611 unsigned spaces; 612 613 if (likely(n >= spec.field_width)) 614 return buf; 615 /* we want to pad the sucker */ 616 spaces = spec.field_width - n; 617 if (!(spec.flags & LEFT)) { 618 move_right(buf - n, end, n, spaces); 619 return buf + spaces; 620 } 621 while (spaces--) { 622 if (buf < end) 623 *buf = ' '; 624 ++buf; 625 } 626 return buf; 627 } 628 629 /* Handle string from a well known address. */ 630 static char *string_nocheck(char *buf, char *end, const char *s, 631 struct printf_spec spec) 632 { 633 int len = 0; 634 int lim = spec.precision; 635 636 while (lim--) { 637 char c = *s++; 638 if (!c) 639 break; 640 if (buf < end) 641 *buf = c; 642 ++buf; 643 ++len; 644 } 645 return widen_string(buf, len, end, spec); 646 } 647 648 static char *err_ptr(char *buf, char *end, void *ptr, 649 struct printf_spec spec) 650 { 651 int err = PTR_ERR(ptr); 652 const char *sym = errname(err); 653 654 if (sym) 655 return string_nocheck(buf, end, sym, spec); 656 657 /* 658 * Somebody passed ERR_PTR(-1234) or some other non-existing 659 * Efoo - or perhaps CONFIG_SYMBOLIC_ERRNAME=n. Fall back to 660 * printing it as its decimal representation. 661 */ 662 spec.flags |= SIGN; 663 spec.base = 10; 664 return number(buf, end, err, spec); 665 } 666 667 /* Be careful: error messages must fit into the given buffer. */ 668 static char *error_string(char *buf, char *end, const char *s, 669 struct printf_spec spec) 670 { 671 /* 672 * Hard limit to avoid a completely insane messages. It actually 673 * works pretty well because most error messages are in 674 * the many pointer format modifiers. 675 */ 676 if (spec.precision == -1) 677 spec.precision = 2 * sizeof(void *); 678 679 return string_nocheck(buf, end, s, spec); 680 } 681 682 /* 683 * Do not call any complex external code here. Nested printk()/vsprintf() 684 * might cause infinite loops. Failures might break printk() and would 685 * be hard to debug. 686 */ 687 static const char *check_pointer_msg(const void *ptr) 688 { 689 if (!ptr) 690 return "(null)"; 691 692 if ((unsigned long)ptr < PAGE_SIZE || IS_ERR_VALUE(ptr)) 693 return "(efault)"; 694 695 return NULL; 696 } 697 698 static int check_pointer(char **buf, char *end, const void *ptr, 699 struct printf_spec spec) 700 { 701 const char *err_msg; 702 703 err_msg = check_pointer_msg(ptr); 704 if (err_msg) { 705 *buf = error_string(*buf, end, err_msg, spec); 706 return -EFAULT; 707 } 708 709 return 0; 710 } 711 712 static noinline_for_stack 713 char *string(char *buf, char *end, const char *s, 714 struct printf_spec spec) 715 { 716 if (check_pointer(&buf, end, s, spec)) 717 return buf; 718 719 return string_nocheck(buf, end, s, spec); 720 } 721 722 static char *pointer_string(char *buf, char *end, 723 const void *ptr, 724 struct printf_spec spec) 725 { 726 spec.base = 16; 727 spec.flags |= SMALL; 728 if (spec.field_width == -1) { 729 spec.field_width = 2 * sizeof(ptr); 730 spec.flags |= ZEROPAD; 731 } 732 733 return number(buf, end, (unsigned long int)ptr, spec); 734 } 735 736 /* Make pointers available for printing early in the boot sequence. */ 737 static int debug_boot_weak_hash __ro_after_init; 738 739 static int __init debug_boot_weak_hash_enable(char *str) 740 { 741 debug_boot_weak_hash = 1; 742 pr_info("debug_boot_weak_hash enabled\n"); 743 return 0; 744 } 745 early_param("debug_boot_weak_hash", debug_boot_weak_hash_enable); 746 747 static DEFINE_STATIC_KEY_TRUE(not_filled_random_ptr_key); 748 static siphash_key_t ptr_key __read_mostly; 749 750 static void enable_ptr_key_workfn(struct work_struct *work) 751 { 752 get_random_bytes(&ptr_key, sizeof(ptr_key)); 753 /* Needs to run from preemptible context */ 754 static_branch_disable(¬_filled_random_ptr_key); 755 } 756 757 static DECLARE_WORK(enable_ptr_key_work, enable_ptr_key_workfn); 758 759 static void fill_random_ptr_key(struct random_ready_callback *unused) 760 { 761 /* This may be in an interrupt handler. */ 762 queue_work(system_unbound_wq, &enable_ptr_key_work); 763 } 764 765 static struct random_ready_callback random_ready = { 766 .func = fill_random_ptr_key 767 }; 768 769 static int __init initialize_ptr_random(void) 770 { 771 int key_size = sizeof(ptr_key); 772 int ret; 773 774 /* Use hw RNG if available. */ 775 if (get_random_bytes_arch(&ptr_key, key_size) == key_size) { 776 static_branch_disable(¬_filled_random_ptr_key); 777 return 0; 778 } 779 780 ret = add_random_ready_callback(&random_ready); 781 if (!ret) { 782 return 0; 783 } else if (ret == -EALREADY) { 784 /* This is in preemptible context */ 785 enable_ptr_key_workfn(&enable_ptr_key_work); 786 return 0; 787 } 788 789 return ret; 790 } 791 early_initcall(initialize_ptr_random); 792 793 /* Maps a pointer to a 32 bit unique identifier. */ 794 static inline int __ptr_to_hashval(const void *ptr, unsigned long *hashval_out) 795 { 796 unsigned long hashval; 797 798 if (static_branch_unlikely(¬_filled_random_ptr_key)) 799 return -EAGAIN; 800 801 #ifdef CONFIG_64BIT 802 hashval = (unsigned long)siphash_1u64((u64)ptr, &ptr_key); 803 /* 804 * Mask off the first 32 bits, this makes explicit that we have 805 * modified the address (and 32 bits is plenty for a unique ID). 806 */ 807 hashval = hashval & 0xffffffff; 808 #else 809 hashval = (unsigned long)siphash_1u32((u32)ptr, &ptr_key); 810 #endif 811 *hashval_out = hashval; 812 return 0; 813 } 814 815 int ptr_to_hashval(const void *ptr, unsigned long *hashval_out) 816 { 817 return __ptr_to_hashval(ptr, hashval_out); 818 } 819 820 static char *ptr_to_id(char *buf, char *end, const void *ptr, 821 struct printf_spec spec) 822 { 823 const char *str = sizeof(ptr) == 8 ? "(____ptrval____)" : "(ptrval)"; 824 unsigned long hashval; 825 int ret; 826 827 /* 828 * Print the real pointer value for NULL and error pointers, 829 * as they are not actual addresses. 830 */ 831 if (IS_ERR_OR_NULL(ptr)) 832 return pointer_string(buf, end, ptr, spec); 833 834 /* When debugging early boot use non-cryptographically secure hash. */ 835 if (unlikely(debug_boot_weak_hash)) { 836 hashval = hash_long((unsigned long)ptr, 32); 837 return pointer_string(buf, end, (const void *)hashval, spec); 838 } 839 840 ret = __ptr_to_hashval(ptr, &hashval); 841 if (ret) { 842 spec.field_width = 2 * sizeof(ptr); 843 /* string length must be less than default_width */ 844 return error_string(buf, end, str, spec); 845 } 846 847 return pointer_string(buf, end, (const void *)hashval, spec); 848 } 849 850 int kptr_restrict __read_mostly; 851 852 static noinline_for_stack 853 char *restricted_pointer(char *buf, char *end, const void *ptr, 854 struct printf_spec spec) 855 { 856 switch (kptr_restrict) { 857 case 0: 858 /* Handle as %p, hash and do _not_ leak addresses. */ 859 return ptr_to_id(buf, end, ptr, spec); 860 case 1: { 861 const struct cred *cred; 862 863 /* 864 * kptr_restrict==1 cannot be used in IRQ context 865 * because its test for CAP_SYSLOG would be meaningless. 866 */ 867 if (in_irq() || in_serving_softirq() || in_nmi()) { 868 if (spec.field_width == -1) 869 spec.field_width = 2 * sizeof(ptr); 870 return error_string(buf, end, "pK-error", spec); 871 } 872 873 /* 874 * Only print the real pointer value if the current 875 * process has CAP_SYSLOG and is running with the 876 * same credentials it started with. This is because 877 * access to files is checked at open() time, but %pK 878 * checks permission at read() time. We don't want to 879 * leak pointer values if a binary opens a file using 880 * %pK and then elevates privileges before reading it. 881 */ 882 cred = current_cred(); 883 if (!has_capability_noaudit(current, CAP_SYSLOG) || 884 !uid_eq(cred->euid, cred->uid) || 885 !gid_eq(cred->egid, cred->gid)) 886 ptr = NULL; 887 break; 888 } 889 case 2: 890 default: 891 /* Always print 0's for %pK */ 892 ptr = NULL; 893 break; 894 } 895 896 return pointer_string(buf, end, ptr, spec); 897 } 898 899 static noinline_for_stack 900 char *dentry_name(char *buf, char *end, const struct dentry *d, struct printf_spec spec, 901 const char *fmt) 902 { 903 const char *array[4], *s; 904 const struct dentry *p; 905 int depth; 906 int i, n; 907 908 switch (fmt[1]) { 909 case '2': case '3': case '4': 910 depth = fmt[1] - '0'; 911 break; 912 default: 913 depth = 1; 914 } 915 916 rcu_read_lock(); 917 for (i = 0; i < depth; i++, d = p) { 918 if (check_pointer(&buf, end, d, spec)) { 919 rcu_read_unlock(); 920 return buf; 921 } 922 923 p = READ_ONCE(d->d_parent); 924 array[i] = READ_ONCE(d->d_name.name); 925 if (p == d) { 926 if (i) 927 array[i] = ""; 928 i++; 929 break; 930 } 931 } 932 s = array[--i]; 933 for (n = 0; n != spec.precision; n++, buf++) { 934 char c = *s++; 935 if (!c) { 936 if (!i) 937 break; 938 c = '/'; 939 s = array[--i]; 940 } 941 if (buf < end) 942 *buf = c; 943 } 944 rcu_read_unlock(); 945 return widen_string(buf, n, end, spec); 946 } 947 948 static noinline_for_stack 949 char *file_dentry_name(char *buf, char *end, const struct file *f, 950 struct printf_spec spec, const char *fmt) 951 { 952 if (check_pointer(&buf, end, f, spec)) 953 return buf; 954 955 return dentry_name(buf, end, f->f_path.dentry, spec, fmt); 956 } 957 #ifdef CONFIG_BLOCK 958 static noinline_for_stack 959 char *bdev_name(char *buf, char *end, struct block_device *bdev, 960 struct printf_spec spec, const char *fmt) 961 { 962 struct gendisk *hd; 963 964 if (check_pointer(&buf, end, bdev, spec)) 965 return buf; 966 967 hd = bdev->bd_disk; 968 buf = string(buf, end, hd->disk_name, spec); 969 if (bdev->bd_partno) { 970 if (isdigit(hd->disk_name[strlen(hd->disk_name)-1])) { 971 if (buf < end) 972 *buf = 'p'; 973 buf++; 974 } 975 buf = number(buf, end, bdev->bd_partno, spec); 976 } 977 return buf; 978 } 979 #endif 980 981 static noinline_for_stack 982 char *symbol_string(char *buf, char *end, void *ptr, 983 struct printf_spec spec, const char *fmt) 984 { 985 unsigned long value; 986 #ifdef CONFIG_KALLSYMS 987 char sym[KSYM_SYMBOL_LEN]; 988 #endif 989 990 if (fmt[1] == 'R') 991 ptr = __builtin_extract_return_addr(ptr); 992 value = (unsigned long)ptr; 993 994 #ifdef CONFIG_KALLSYMS 995 if (*fmt == 'B') 996 sprint_backtrace(sym, value); 997 else if (*fmt != 's') 998 sprint_symbol(sym, value); 999 else 1000 sprint_symbol_no_offset(sym, value); 1001 1002 return string_nocheck(buf, end, sym, spec); 1003 #else 1004 return special_hex_number(buf, end, value, sizeof(void *)); 1005 #endif 1006 } 1007 1008 static const struct printf_spec default_str_spec = { 1009 .field_width = -1, 1010 .precision = -1, 1011 }; 1012 1013 static const struct printf_spec default_flag_spec = { 1014 .base = 16, 1015 .precision = -1, 1016 .flags = SPECIAL | SMALL, 1017 }; 1018 1019 static const struct printf_spec default_dec_spec = { 1020 .base = 10, 1021 .precision = -1, 1022 }; 1023 1024 static const struct printf_spec default_dec02_spec = { 1025 .base = 10, 1026 .field_width = 2, 1027 .precision = -1, 1028 .flags = ZEROPAD, 1029 }; 1030 1031 static const struct printf_spec default_dec04_spec = { 1032 .base = 10, 1033 .field_width = 4, 1034 .precision = -1, 1035 .flags = ZEROPAD, 1036 }; 1037 1038 static noinline_for_stack 1039 char *resource_string(char *buf, char *end, struct resource *res, 1040 struct printf_spec spec, const char *fmt) 1041 { 1042 #ifndef IO_RSRC_PRINTK_SIZE 1043 #define IO_RSRC_PRINTK_SIZE 6 1044 #endif 1045 1046 #ifndef MEM_RSRC_PRINTK_SIZE 1047 #define MEM_RSRC_PRINTK_SIZE 10 1048 #endif 1049 static const struct printf_spec io_spec = { 1050 .base = 16, 1051 .field_width = IO_RSRC_PRINTK_SIZE, 1052 .precision = -1, 1053 .flags = SPECIAL | SMALL | ZEROPAD, 1054 }; 1055 static const struct printf_spec mem_spec = { 1056 .base = 16, 1057 .field_width = MEM_RSRC_PRINTK_SIZE, 1058 .precision = -1, 1059 .flags = SPECIAL | SMALL | ZEROPAD, 1060 }; 1061 static const struct printf_spec bus_spec = { 1062 .base = 16, 1063 .field_width = 2, 1064 .precision = -1, 1065 .flags = SMALL | ZEROPAD, 1066 }; 1067 static const struct printf_spec str_spec = { 1068 .field_width = -1, 1069 .precision = 10, 1070 .flags = LEFT, 1071 }; 1072 1073 /* 32-bit res (sizeof==4): 10 chars in dec, 10 in hex ("0x" + 8) 1074 * 64-bit res (sizeof==8): 20 chars in dec, 18 in hex ("0x" + 16) */ 1075 #define RSRC_BUF_SIZE ((2 * sizeof(resource_size_t)) + 4) 1076 #define FLAG_BUF_SIZE (2 * sizeof(res->flags)) 1077 #define DECODED_BUF_SIZE sizeof("[mem - 64bit pref window disabled]") 1078 #define RAW_BUF_SIZE sizeof("[mem - flags 0x]") 1079 char sym[max(2*RSRC_BUF_SIZE + DECODED_BUF_SIZE, 1080 2*RSRC_BUF_SIZE + FLAG_BUF_SIZE + RAW_BUF_SIZE)]; 1081 1082 char *p = sym, *pend = sym + sizeof(sym); 1083 int decode = (fmt[0] == 'R') ? 1 : 0; 1084 const struct printf_spec *specp; 1085 1086 if (check_pointer(&buf, end, res, spec)) 1087 return buf; 1088 1089 *p++ = '['; 1090 if (res->flags & IORESOURCE_IO) { 1091 p = string_nocheck(p, pend, "io ", str_spec); 1092 specp = &io_spec; 1093 } else if (res->flags & IORESOURCE_MEM) { 1094 p = string_nocheck(p, pend, "mem ", str_spec); 1095 specp = &mem_spec; 1096 } else if (res->flags & IORESOURCE_IRQ) { 1097 p = string_nocheck(p, pend, "irq ", str_spec); 1098 specp = &default_dec_spec; 1099 } else if (res->flags & IORESOURCE_DMA) { 1100 p = string_nocheck(p, pend, "dma ", str_spec); 1101 specp = &default_dec_spec; 1102 } else if (res->flags & IORESOURCE_BUS) { 1103 p = string_nocheck(p, pend, "bus ", str_spec); 1104 specp = &bus_spec; 1105 } else { 1106 p = string_nocheck(p, pend, "??? ", str_spec); 1107 specp = &mem_spec; 1108 decode = 0; 1109 } 1110 if (decode && res->flags & IORESOURCE_UNSET) { 1111 p = string_nocheck(p, pend, "size ", str_spec); 1112 p = number(p, pend, resource_size(res), *specp); 1113 } else { 1114 p = number(p, pend, res->start, *specp); 1115 if (res->start != res->end) { 1116 *p++ = '-'; 1117 p = number(p, pend, res->end, *specp); 1118 } 1119 } 1120 if (decode) { 1121 if (res->flags & IORESOURCE_MEM_64) 1122 p = string_nocheck(p, pend, " 64bit", str_spec); 1123 if (res->flags & IORESOURCE_PREFETCH) 1124 p = string_nocheck(p, pend, " pref", str_spec); 1125 if (res->flags & IORESOURCE_WINDOW) 1126 p = string_nocheck(p, pend, " window", str_spec); 1127 if (res->flags & IORESOURCE_DISABLED) 1128 p = string_nocheck(p, pend, " disabled", str_spec); 1129 } else { 1130 p = string_nocheck(p, pend, " flags ", str_spec); 1131 p = number(p, pend, res->flags, default_flag_spec); 1132 } 1133 *p++ = ']'; 1134 *p = '\0'; 1135 1136 return string_nocheck(buf, end, sym, spec); 1137 } 1138 1139 static noinline_for_stack 1140 char *hex_string(char *buf, char *end, u8 *addr, struct printf_spec spec, 1141 const char *fmt) 1142 { 1143 int i, len = 1; /* if we pass '%ph[CDN]', field width remains 1144 negative value, fallback to the default */ 1145 char separator; 1146 1147 if (spec.field_width == 0) 1148 /* nothing to print */ 1149 return buf; 1150 1151 if (check_pointer(&buf, end, addr, spec)) 1152 return buf; 1153 1154 switch (fmt[1]) { 1155 case 'C': 1156 separator = ':'; 1157 break; 1158 case 'D': 1159 separator = '-'; 1160 break; 1161 case 'N': 1162 separator = 0; 1163 break; 1164 default: 1165 separator = ' '; 1166 break; 1167 } 1168 1169 if (spec.field_width > 0) 1170 len = min_t(int, spec.field_width, 64); 1171 1172 for (i = 0; i < len; ++i) { 1173 if (buf < end) 1174 *buf = hex_asc_hi(addr[i]); 1175 ++buf; 1176 if (buf < end) 1177 *buf = hex_asc_lo(addr[i]); 1178 ++buf; 1179 1180 if (separator && i != len - 1) { 1181 if (buf < end) 1182 *buf = separator; 1183 ++buf; 1184 } 1185 } 1186 1187 return buf; 1188 } 1189 1190 static noinline_for_stack 1191 char *bitmap_string(char *buf, char *end, unsigned long *bitmap, 1192 struct printf_spec spec, const char *fmt) 1193 { 1194 const int CHUNKSZ = 32; 1195 int nr_bits = max_t(int, spec.field_width, 0); 1196 int i, chunksz; 1197 bool first = true; 1198 1199 if (check_pointer(&buf, end, bitmap, spec)) 1200 return buf; 1201 1202 /* reused to print numbers */ 1203 spec = (struct printf_spec){ .flags = SMALL | ZEROPAD, .base = 16 }; 1204 1205 chunksz = nr_bits & (CHUNKSZ - 1); 1206 if (chunksz == 0) 1207 chunksz = CHUNKSZ; 1208 1209 i = ALIGN(nr_bits, CHUNKSZ) - CHUNKSZ; 1210 for (; i >= 0; i -= CHUNKSZ) { 1211 u32 chunkmask, val; 1212 int word, bit; 1213 1214 chunkmask = ((1ULL << chunksz) - 1); 1215 word = i / BITS_PER_LONG; 1216 bit = i % BITS_PER_LONG; 1217 val = (bitmap[word] >> bit) & chunkmask; 1218 1219 if (!first) { 1220 if (buf < end) 1221 *buf = ','; 1222 buf++; 1223 } 1224 first = false; 1225 1226 spec.field_width = DIV_ROUND_UP(chunksz, 4); 1227 buf = number(buf, end, val, spec); 1228 1229 chunksz = CHUNKSZ; 1230 } 1231 return buf; 1232 } 1233 1234 static noinline_for_stack 1235 char *bitmap_list_string(char *buf, char *end, unsigned long *bitmap, 1236 struct printf_spec spec, const char *fmt) 1237 { 1238 int nr_bits = max_t(int, spec.field_width, 0); 1239 /* current bit is 'cur', most recently seen range is [rbot, rtop] */ 1240 int cur, rbot, rtop; 1241 bool first = true; 1242 1243 if (check_pointer(&buf, end, bitmap, spec)) 1244 return buf; 1245 1246 rbot = cur = find_first_bit(bitmap, nr_bits); 1247 while (cur < nr_bits) { 1248 rtop = cur; 1249 cur = find_next_bit(bitmap, nr_bits, cur + 1); 1250 if (cur < nr_bits && cur <= rtop + 1) 1251 continue; 1252 1253 if (!first) { 1254 if (buf < end) 1255 *buf = ','; 1256 buf++; 1257 } 1258 first = false; 1259 1260 buf = number(buf, end, rbot, default_dec_spec); 1261 if (rbot < rtop) { 1262 if (buf < end) 1263 *buf = '-'; 1264 buf++; 1265 1266 buf = number(buf, end, rtop, default_dec_spec); 1267 } 1268 1269 rbot = cur; 1270 } 1271 return buf; 1272 } 1273 1274 static noinline_for_stack 1275 char *mac_address_string(char *buf, char *end, u8 *addr, 1276 struct printf_spec spec, const char *fmt) 1277 { 1278 char mac_addr[sizeof("xx:xx:xx:xx:xx:xx")]; 1279 char *p = mac_addr; 1280 int i; 1281 char separator; 1282 bool reversed = false; 1283 1284 if (check_pointer(&buf, end, addr, spec)) 1285 return buf; 1286 1287 switch (fmt[1]) { 1288 case 'F': 1289 separator = '-'; 1290 break; 1291 1292 case 'R': 1293 reversed = true; 1294 fallthrough; 1295 1296 default: 1297 separator = ':'; 1298 break; 1299 } 1300 1301 for (i = 0; i < 6; i++) { 1302 if (reversed) 1303 p = hex_byte_pack(p, addr[5 - i]); 1304 else 1305 p = hex_byte_pack(p, addr[i]); 1306 1307 if (fmt[0] == 'M' && i != 5) 1308 *p++ = separator; 1309 } 1310 *p = '\0'; 1311 1312 return string_nocheck(buf, end, mac_addr, spec); 1313 } 1314 1315 static noinline_for_stack 1316 char *ip4_string(char *p, const u8 *addr, const char *fmt) 1317 { 1318 int i; 1319 bool leading_zeros = (fmt[0] == 'i'); 1320 int index; 1321 int step; 1322 1323 switch (fmt[2]) { 1324 case 'h': 1325 #ifdef __BIG_ENDIAN 1326 index = 0; 1327 step = 1; 1328 #else 1329 index = 3; 1330 step = -1; 1331 #endif 1332 break; 1333 case 'l': 1334 index = 3; 1335 step = -1; 1336 break; 1337 case 'n': 1338 case 'b': 1339 default: 1340 index = 0; 1341 step = 1; 1342 break; 1343 } 1344 for (i = 0; i < 4; i++) { 1345 char temp[4] __aligned(2); /* hold each IP quad in reverse order */ 1346 int digits = put_dec_trunc8(temp, addr[index]) - temp; 1347 if (leading_zeros) { 1348 if (digits < 3) 1349 *p++ = '0'; 1350 if (digits < 2) 1351 *p++ = '0'; 1352 } 1353 /* reverse the digits in the quad */ 1354 while (digits--) 1355 *p++ = temp[digits]; 1356 if (i < 3) 1357 *p++ = '.'; 1358 index += step; 1359 } 1360 *p = '\0'; 1361 1362 return p; 1363 } 1364 1365 static noinline_for_stack 1366 char *ip6_compressed_string(char *p, const char *addr) 1367 { 1368 int i, j, range; 1369 unsigned char zerolength[8]; 1370 int longest = 1; 1371 int colonpos = -1; 1372 u16 word; 1373 u8 hi, lo; 1374 bool needcolon = false; 1375 bool useIPv4; 1376 struct in6_addr in6; 1377 1378 memcpy(&in6, addr, sizeof(struct in6_addr)); 1379 1380 useIPv4 = ipv6_addr_v4mapped(&in6) || ipv6_addr_is_isatap(&in6); 1381 1382 memset(zerolength, 0, sizeof(zerolength)); 1383 1384 if (useIPv4) 1385 range = 6; 1386 else 1387 range = 8; 1388 1389 /* find position of longest 0 run */ 1390 for (i = 0; i < range; i++) { 1391 for (j = i; j < range; j++) { 1392 if (in6.s6_addr16[j] != 0) 1393 break; 1394 zerolength[i]++; 1395 } 1396 } 1397 for (i = 0; i < range; i++) { 1398 if (zerolength[i] > longest) { 1399 longest = zerolength[i]; 1400 colonpos = i; 1401 } 1402 } 1403 if (longest == 1) /* don't compress a single 0 */ 1404 colonpos = -1; 1405 1406 /* emit address */ 1407 for (i = 0; i < range; i++) { 1408 if (i == colonpos) { 1409 if (needcolon || i == 0) 1410 *p++ = ':'; 1411 *p++ = ':'; 1412 needcolon = false; 1413 i += longest - 1; 1414 continue; 1415 } 1416 if (needcolon) { 1417 *p++ = ':'; 1418 needcolon = false; 1419 } 1420 /* hex u16 without leading 0s */ 1421 word = ntohs(in6.s6_addr16[i]); 1422 hi = word >> 8; 1423 lo = word & 0xff; 1424 if (hi) { 1425 if (hi > 0x0f) 1426 p = hex_byte_pack(p, hi); 1427 else 1428 *p++ = hex_asc_lo(hi); 1429 p = hex_byte_pack(p, lo); 1430 } 1431 else if (lo > 0x0f) 1432 p = hex_byte_pack(p, lo); 1433 else 1434 *p++ = hex_asc_lo(lo); 1435 needcolon = true; 1436 } 1437 1438 if (useIPv4) { 1439 if (needcolon) 1440 *p++ = ':'; 1441 p = ip4_string(p, &in6.s6_addr[12], "I4"); 1442 } 1443 *p = '\0'; 1444 1445 return p; 1446 } 1447 1448 static noinline_for_stack 1449 char *ip6_string(char *p, const char *addr, const char *fmt) 1450 { 1451 int i; 1452 1453 for (i = 0; i < 8; i++) { 1454 p = hex_byte_pack(p, *addr++); 1455 p = hex_byte_pack(p, *addr++); 1456 if (fmt[0] == 'I' && i != 7) 1457 *p++ = ':'; 1458 } 1459 *p = '\0'; 1460 1461 return p; 1462 } 1463 1464 static noinline_for_stack 1465 char *ip6_addr_string(char *buf, char *end, const u8 *addr, 1466 struct printf_spec spec, const char *fmt) 1467 { 1468 char ip6_addr[sizeof("xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255")]; 1469 1470 if (fmt[0] == 'I' && fmt[2] == 'c') 1471 ip6_compressed_string(ip6_addr, addr); 1472 else 1473 ip6_string(ip6_addr, addr, fmt); 1474 1475 return string_nocheck(buf, end, ip6_addr, spec); 1476 } 1477 1478 static noinline_for_stack 1479 char *ip4_addr_string(char *buf, char *end, const u8 *addr, 1480 struct printf_spec spec, const char *fmt) 1481 { 1482 char ip4_addr[sizeof("255.255.255.255")]; 1483 1484 ip4_string(ip4_addr, addr, fmt); 1485 1486 return string_nocheck(buf, end, ip4_addr, spec); 1487 } 1488 1489 static noinline_for_stack 1490 char *ip6_addr_string_sa(char *buf, char *end, const struct sockaddr_in6 *sa, 1491 struct printf_spec spec, const char *fmt) 1492 { 1493 bool have_p = false, have_s = false, have_f = false, have_c = false; 1494 char ip6_addr[sizeof("[xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255]") + 1495 sizeof(":12345") + sizeof("/123456789") + 1496 sizeof("%1234567890")]; 1497 char *p = ip6_addr, *pend = ip6_addr + sizeof(ip6_addr); 1498 const u8 *addr = (const u8 *) &sa->sin6_addr; 1499 char fmt6[2] = { fmt[0], '6' }; 1500 u8 off = 0; 1501 1502 fmt++; 1503 while (isalpha(*++fmt)) { 1504 switch (*fmt) { 1505 case 'p': 1506 have_p = true; 1507 break; 1508 case 'f': 1509 have_f = true; 1510 break; 1511 case 's': 1512 have_s = true; 1513 break; 1514 case 'c': 1515 have_c = true; 1516 break; 1517 } 1518 } 1519 1520 if (have_p || have_s || have_f) { 1521 *p = '['; 1522 off = 1; 1523 } 1524 1525 if (fmt6[0] == 'I' && have_c) 1526 p = ip6_compressed_string(ip6_addr + off, addr); 1527 else 1528 p = ip6_string(ip6_addr + off, addr, fmt6); 1529 1530 if (have_p || have_s || have_f) 1531 *p++ = ']'; 1532 1533 if (have_p) { 1534 *p++ = ':'; 1535 p = number(p, pend, ntohs(sa->sin6_port), spec); 1536 } 1537 if (have_f) { 1538 *p++ = '/'; 1539 p = number(p, pend, ntohl(sa->sin6_flowinfo & 1540 IPV6_FLOWINFO_MASK), spec); 1541 } 1542 if (have_s) { 1543 *p++ = '%'; 1544 p = number(p, pend, sa->sin6_scope_id, spec); 1545 } 1546 *p = '\0'; 1547 1548 return string_nocheck(buf, end, ip6_addr, spec); 1549 } 1550 1551 static noinline_for_stack 1552 char *ip4_addr_string_sa(char *buf, char *end, const struct sockaddr_in *sa, 1553 struct printf_spec spec, const char *fmt) 1554 { 1555 bool have_p = false; 1556 char *p, ip4_addr[sizeof("255.255.255.255") + sizeof(":12345")]; 1557 char *pend = ip4_addr + sizeof(ip4_addr); 1558 const u8 *addr = (const u8 *) &sa->sin_addr.s_addr; 1559 char fmt4[3] = { fmt[0], '4', 0 }; 1560 1561 fmt++; 1562 while (isalpha(*++fmt)) { 1563 switch (*fmt) { 1564 case 'p': 1565 have_p = true; 1566 break; 1567 case 'h': 1568 case 'l': 1569 case 'n': 1570 case 'b': 1571 fmt4[2] = *fmt; 1572 break; 1573 } 1574 } 1575 1576 p = ip4_string(ip4_addr, addr, fmt4); 1577 if (have_p) { 1578 *p++ = ':'; 1579 p = number(p, pend, ntohs(sa->sin_port), spec); 1580 } 1581 *p = '\0'; 1582 1583 return string_nocheck(buf, end, ip4_addr, spec); 1584 } 1585 1586 static noinline_for_stack 1587 char *ip_addr_string(char *buf, char *end, const void *ptr, 1588 struct printf_spec spec, const char *fmt) 1589 { 1590 char *err_fmt_msg; 1591 1592 if (check_pointer(&buf, end, ptr, spec)) 1593 return buf; 1594 1595 switch (fmt[1]) { 1596 case '6': 1597 return ip6_addr_string(buf, end, ptr, spec, fmt); 1598 case '4': 1599 return ip4_addr_string(buf, end, ptr, spec, fmt); 1600 case 'S': { 1601 const union { 1602 struct sockaddr raw; 1603 struct sockaddr_in v4; 1604 struct sockaddr_in6 v6; 1605 } *sa = ptr; 1606 1607 switch (sa->raw.sa_family) { 1608 case AF_INET: 1609 return ip4_addr_string_sa(buf, end, &sa->v4, spec, fmt); 1610 case AF_INET6: 1611 return ip6_addr_string_sa(buf, end, &sa->v6, spec, fmt); 1612 default: 1613 return error_string(buf, end, "(einval)", spec); 1614 }} 1615 } 1616 1617 err_fmt_msg = fmt[0] == 'i' ? "(%pi?)" : "(%pI?)"; 1618 return error_string(buf, end, err_fmt_msg, spec); 1619 } 1620 1621 static noinline_for_stack 1622 char *escaped_string(char *buf, char *end, u8 *addr, struct printf_spec spec, 1623 const char *fmt) 1624 { 1625 bool found = true; 1626 int count = 1; 1627 unsigned int flags = 0; 1628 int len; 1629 1630 if (spec.field_width == 0) 1631 return buf; /* nothing to print */ 1632 1633 if (check_pointer(&buf, end, addr, spec)) 1634 return buf; 1635 1636 do { 1637 switch (fmt[count++]) { 1638 case 'a': 1639 flags |= ESCAPE_ANY; 1640 break; 1641 case 'c': 1642 flags |= ESCAPE_SPECIAL; 1643 break; 1644 case 'h': 1645 flags |= ESCAPE_HEX; 1646 break; 1647 case 'n': 1648 flags |= ESCAPE_NULL; 1649 break; 1650 case 'o': 1651 flags |= ESCAPE_OCTAL; 1652 break; 1653 case 'p': 1654 flags |= ESCAPE_NP; 1655 break; 1656 case 's': 1657 flags |= ESCAPE_SPACE; 1658 break; 1659 default: 1660 found = false; 1661 break; 1662 } 1663 } while (found); 1664 1665 if (!flags) 1666 flags = ESCAPE_ANY_NP; 1667 1668 len = spec.field_width < 0 ? 1 : spec.field_width; 1669 1670 /* 1671 * string_escape_mem() writes as many characters as it can to 1672 * the given buffer, and returns the total size of the output 1673 * had the buffer been big enough. 1674 */ 1675 buf += string_escape_mem(addr, len, buf, buf < end ? end - buf : 0, flags, NULL); 1676 1677 return buf; 1678 } 1679 1680 static char *va_format(char *buf, char *end, struct va_format *va_fmt, 1681 struct printf_spec spec, const char *fmt) 1682 { 1683 va_list va; 1684 1685 if (check_pointer(&buf, end, va_fmt, spec)) 1686 return buf; 1687 1688 va_copy(va, *va_fmt->va); 1689 buf += vsnprintf(buf, end > buf ? end - buf : 0, va_fmt->fmt, va); 1690 va_end(va); 1691 1692 return buf; 1693 } 1694 1695 static noinline_for_stack 1696 char *uuid_string(char *buf, char *end, const u8 *addr, 1697 struct printf_spec spec, const char *fmt) 1698 { 1699 char uuid[UUID_STRING_LEN + 1]; 1700 char *p = uuid; 1701 int i; 1702 const u8 *index = uuid_index; 1703 bool uc = false; 1704 1705 if (check_pointer(&buf, end, addr, spec)) 1706 return buf; 1707 1708 switch (*(++fmt)) { 1709 case 'L': 1710 uc = true; 1711 fallthrough; 1712 case 'l': 1713 index = guid_index; 1714 break; 1715 case 'B': 1716 uc = true; 1717 break; 1718 } 1719 1720 for (i = 0; i < 16; i++) { 1721 if (uc) 1722 p = hex_byte_pack_upper(p, addr[index[i]]); 1723 else 1724 p = hex_byte_pack(p, addr[index[i]]); 1725 switch (i) { 1726 case 3: 1727 case 5: 1728 case 7: 1729 case 9: 1730 *p++ = '-'; 1731 break; 1732 } 1733 } 1734 1735 *p = 0; 1736 1737 return string_nocheck(buf, end, uuid, spec); 1738 } 1739 1740 static noinline_for_stack 1741 char *netdev_bits(char *buf, char *end, const void *addr, 1742 struct printf_spec spec, const char *fmt) 1743 { 1744 unsigned long long num; 1745 int size; 1746 1747 if (check_pointer(&buf, end, addr, spec)) 1748 return buf; 1749 1750 switch (fmt[1]) { 1751 case 'F': 1752 num = *(const netdev_features_t *)addr; 1753 size = sizeof(netdev_features_t); 1754 break; 1755 default: 1756 return error_string(buf, end, "(%pN?)", spec); 1757 } 1758 1759 return special_hex_number(buf, end, num, size); 1760 } 1761 1762 static noinline_for_stack 1763 char *address_val(char *buf, char *end, const void *addr, 1764 struct printf_spec spec, const char *fmt) 1765 { 1766 unsigned long long num; 1767 int size; 1768 1769 if (check_pointer(&buf, end, addr, spec)) 1770 return buf; 1771 1772 switch (fmt[1]) { 1773 case 'd': 1774 num = *(const dma_addr_t *)addr; 1775 size = sizeof(dma_addr_t); 1776 break; 1777 case 'p': 1778 default: 1779 num = *(const phys_addr_t *)addr; 1780 size = sizeof(phys_addr_t); 1781 break; 1782 } 1783 1784 return special_hex_number(buf, end, num, size); 1785 } 1786 1787 static noinline_for_stack 1788 char *date_str(char *buf, char *end, const struct rtc_time *tm, bool r) 1789 { 1790 int year = tm->tm_year + (r ? 0 : 1900); 1791 int mon = tm->tm_mon + (r ? 0 : 1); 1792 1793 buf = number(buf, end, year, default_dec04_spec); 1794 if (buf < end) 1795 *buf = '-'; 1796 buf++; 1797 1798 buf = number(buf, end, mon, default_dec02_spec); 1799 if (buf < end) 1800 *buf = '-'; 1801 buf++; 1802 1803 return number(buf, end, tm->tm_mday, default_dec02_spec); 1804 } 1805 1806 static noinline_for_stack 1807 char *time_str(char *buf, char *end, const struct rtc_time *tm, bool r) 1808 { 1809 buf = number(buf, end, tm->tm_hour, default_dec02_spec); 1810 if (buf < end) 1811 *buf = ':'; 1812 buf++; 1813 1814 buf = number(buf, end, tm->tm_min, default_dec02_spec); 1815 if (buf < end) 1816 *buf = ':'; 1817 buf++; 1818 1819 return number(buf, end, tm->tm_sec, default_dec02_spec); 1820 } 1821 1822 static noinline_for_stack 1823 char *rtc_str(char *buf, char *end, const struct rtc_time *tm, 1824 struct printf_spec spec, const char *fmt) 1825 { 1826 bool have_t = true, have_d = true; 1827 bool raw = false; 1828 int count = 2; 1829 1830 if (check_pointer(&buf, end, tm, spec)) 1831 return buf; 1832 1833 switch (fmt[count]) { 1834 case 'd': 1835 have_t = false; 1836 count++; 1837 break; 1838 case 't': 1839 have_d = false; 1840 count++; 1841 break; 1842 } 1843 1844 raw = fmt[count] == 'r'; 1845 1846 if (have_d) 1847 buf = date_str(buf, end, tm, raw); 1848 if (have_d && have_t) { 1849 /* Respect ISO 8601 */ 1850 if (buf < end) 1851 *buf = 'T'; 1852 buf++; 1853 } 1854 if (have_t) 1855 buf = time_str(buf, end, tm, raw); 1856 1857 return buf; 1858 } 1859 1860 static noinline_for_stack 1861 char *time64_str(char *buf, char *end, const time64_t time, 1862 struct printf_spec spec, const char *fmt) 1863 { 1864 struct rtc_time rtc_time; 1865 struct tm tm; 1866 1867 time64_to_tm(time, 0, &tm); 1868 1869 rtc_time.tm_sec = tm.tm_sec; 1870 rtc_time.tm_min = tm.tm_min; 1871 rtc_time.tm_hour = tm.tm_hour; 1872 rtc_time.tm_mday = tm.tm_mday; 1873 rtc_time.tm_mon = tm.tm_mon; 1874 rtc_time.tm_year = tm.tm_year; 1875 rtc_time.tm_wday = tm.tm_wday; 1876 rtc_time.tm_yday = tm.tm_yday; 1877 1878 rtc_time.tm_isdst = 0; 1879 1880 return rtc_str(buf, end, &rtc_time, spec, fmt); 1881 } 1882 1883 static noinline_for_stack 1884 char *time_and_date(char *buf, char *end, void *ptr, struct printf_spec spec, 1885 const char *fmt) 1886 { 1887 switch (fmt[1]) { 1888 case 'R': 1889 return rtc_str(buf, end, (const struct rtc_time *)ptr, spec, fmt); 1890 case 'T': 1891 return time64_str(buf, end, *(const time64_t *)ptr, spec, fmt); 1892 default: 1893 return error_string(buf, end, "(%pt?)", spec); 1894 } 1895 } 1896 1897 static noinline_for_stack 1898 char *clock(char *buf, char *end, struct clk *clk, struct printf_spec spec, 1899 const char *fmt) 1900 { 1901 if (!IS_ENABLED(CONFIG_HAVE_CLK)) 1902 return error_string(buf, end, "(%pC?)", spec); 1903 1904 if (check_pointer(&buf, end, clk, spec)) 1905 return buf; 1906 1907 switch (fmt[1]) { 1908 case 'n': 1909 default: 1910 #ifdef CONFIG_COMMON_CLK 1911 return string(buf, end, __clk_get_name(clk), spec); 1912 #else 1913 return ptr_to_id(buf, end, clk, spec); 1914 #endif 1915 } 1916 } 1917 1918 static 1919 char *format_flags(char *buf, char *end, unsigned long flags, 1920 const struct trace_print_flags *names) 1921 { 1922 unsigned long mask; 1923 1924 for ( ; flags && names->name; names++) { 1925 mask = names->mask; 1926 if ((flags & mask) != mask) 1927 continue; 1928 1929 buf = string(buf, end, names->name, default_str_spec); 1930 1931 flags &= ~mask; 1932 if (flags) { 1933 if (buf < end) 1934 *buf = '|'; 1935 buf++; 1936 } 1937 } 1938 1939 if (flags) 1940 buf = number(buf, end, flags, default_flag_spec); 1941 1942 return buf; 1943 } 1944 1945 struct page_flags_fields { 1946 int width; 1947 int shift; 1948 int mask; 1949 const struct printf_spec *spec; 1950 const char *name; 1951 }; 1952 1953 static const struct page_flags_fields pff[] = { 1954 {SECTIONS_WIDTH, SECTIONS_PGSHIFT, SECTIONS_MASK, 1955 &default_dec_spec, "section"}, 1956 {NODES_WIDTH, NODES_PGSHIFT, NODES_MASK, 1957 &default_dec_spec, "node"}, 1958 {ZONES_WIDTH, ZONES_PGSHIFT, ZONES_MASK, 1959 &default_dec_spec, "zone"}, 1960 {LAST_CPUPID_WIDTH, LAST_CPUPID_PGSHIFT, LAST_CPUPID_MASK, 1961 &default_flag_spec, "lastcpupid"}, 1962 {KASAN_TAG_WIDTH, KASAN_TAG_PGSHIFT, KASAN_TAG_MASK, 1963 &default_flag_spec, "kasantag"}, 1964 }; 1965 1966 static 1967 char *format_page_flags(char *buf, char *end, unsigned long flags) 1968 { 1969 unsigned long main_flags = flags & (BIT(NR_PAGEFLAGS) - 1); 1970 bool append = false; 1971 int i; 1972 1973 /* Page flags from the main area. */ 1974 if (main_flags) { 1975 buf = format_flags(buf, end, main_flags, pageflag_names); 1976 append = true; 1977 } 1978 1979 /* Page flags from the fields area */ 1980 for (i = 0; i < ARRAY_SIZE(pff); i++) { 1981 /* Skip undefined fields. */ 1982 if (!pff[i].width) 1983 continue; 1984 1985 /* Format: Flag Name + '=' (equals sign) + Number + '|' (separator) */ 1986 if (append) { 1987 if (buf < end) 1988 *buf = '|'; 1989 buf++; 1990 } 1991 1992 buf = string(buf, end, pff[i].name, default_str_spec); 1993 if (buf < end) 1994 *buf = '='; 1995 buf++; 1996 buf = number(buf, end, (flags >> pff[i].shift) & pff[i].mask, 1997 *pff[i].spec); 1998 1999 append = true; 2000 } 2001 2002 return buf; 2003 } 2004 2005 static noinline_for_stack 2006 char *flags_string(char *buf, char *end, void *flags_ptr, 2007 struct printf_spec spec, const char *fmt) 2008 { 2009 unsigned long flags; 2010 const struct trace_print_flags *names; 2011 2012 if (check_pointer(&buf, end, flags_ptr, spec)) 2013 return buf; 2014 2015 switch (fmt[1]) { 2016 case 'p': 2017 return format_page_flags(buf, end, *(unsigned long *)flags_ptr); 2018 case 'v': 2019 flags = *(unsigned long *)flags_ptr; 2020 names = vmaflag_names; 2021 break; 2022 case 'g': 2023 flags = (__force unsigned long)(*(gfp_t *)flags_ptr); 2024 names = gfpflag_names; 2025 break; 2026 default: 2027 return error_string(buf, end, "(%pG?)", spec); 2028 } 2029 2030 return format_flags(buf, end, flags, names); 2031 } 2032 2033 static noinline_for_stack 2034 char *fwnode_full_name_string(struct fwnode_handle *fwnode, char *buf, 2035 char *end) 2036 { 2037 int depth; 2038 2039 /* Loop starting from the root node to the current node. */ 2040 for (depth = fwnode_count_parents(fwnode); depth >= 0; depth--) { 2041 struct fwnode_handle *__fwnode = 2042 fwnode_get_nth_parent(fwnode, depth); 2043 2044 buf = string(buf, end, fwnode_get_name_prefix(__fwnode), 2045 default_str_spec); 2046 buf = string(buf, end, fwnode_get_name(__fwnode), 2047 default_str_spec); 2048 2049 fwnode_handle_put(__fwnode); 2050 } 2051 2052 return buf; 2053 } 2054 2055 static noinline_for_stack 2056 char *device_node_string(char *buf, char *end, struct device_node *dn, 2057 struct printf_spec spec, const char *fmt) 2058 { 2059 char tbuf[sizeof("xxxx") + 1]; 2060 const char *p; 2061 int ret; 2062 char *buf_start = buf; 2063 struct property *prop; 2064 bool has_mult, pass; 2065 2066 struct printf_spec str_spec = spec; 2067 str_spec.field_width = -1; 2068 2069 if (fmt[0] != 'F') 2070 return error_string(buf, end, "(%pO?)", spec); 2071 2072 if (!IS_ENABLED(CONFIG_OF)) 2073 return error_string(buf, end, "(%pOF?)", spec); 2074 2075 if (check_pointer(&buf, end, dn, spec)) 2076 return buf; 2077 2078 /* simple case without anything any more format specifiers */ 2079 fmt++; 2080 if (fmt[0] == '\0' || strcspn(fmt,"fnpPFcC") > 0) 2081 fmt = "f"; 2082 2083 for (pass = false; strspn(fmt,"fnpPFcC"); fmt++, pass = true) { 2084 int precision; 2085 if (pass) { 2086 if (buf < end) 2087 *buf = ':'; 2088 buf++; 2089 } 2090 2091 switch (*fmt) { 2092 case 'f': /* full_name */ 2093 buf = fwnode_full_name_string(of_fwnode_handle(dn), buf, 2094 end); 2095 break; 2096 case 'n': /* name */ 2097 p = fwnode_get_name(of_fwnode_handle(dn)); 2098 precision = str_spec.precision; 2099 str_spec.precision = strchrnul(p, '@') - p; 2100 buf = string(buf, end, p, str_spec); 2101 str_spec.precision = precision; 2102 break; 2103 case 'p': /* phandle */ 2104 buf = number(buf, end, (unsigned int)dn->phandle, default_dec_spec); 2105 break; 2106 case 'P': /* path-spec */ 2107 p = fwnode_get_name(of_fwnode_handle(dn)); 2108 if (!p[1]) 2109 p = "/"; 2110 buf = string(buf, end, p, str_spec); 2111 break; 2112 case 'F': /* flags */ 2113 tbuf[0] = of_node_check_flag(dn, OF_DYNAMIC) ? 'D' : '-'; 2114 tbuf[1] = of_node_check_flag(dn, OF_DETACHED) ? 'd' : '-'; 2115 tbuf[2] = of_node_check_flag(dn, OF_POPULATED) ? 'P' : '-'; 2116 tbuf[3] = of_node_check_flag(dn, OF_POPULATED_BUS) ? 'B' : '-'; 2117 tbuf[4] = 0; 2118 buf = string_nocheck(buf, end, tbuf, str_spec); 2119 break; 2120 case 'c': /* major compatible string */ 2121 ret = of_property_read_string(dn, "compatible", &p); 2122 if (!ret) 2123 buf = string(buf, end, p, str_spec); 2124 break; 2125 case 'C': /* full compatible string */ 2126 has_mult = false; 2127 of_property_for_each_string(dn, "compatible", prop, p) { 2128 if (has_mult) 2129 buf = string_nocheck(buf, end, ",", str_spec); 2130 buf = string_nocheck(buf, end, "\"", str_spec); 2131 buf = string(buf, end, p, str_spec); 2132 buf = string_nocheck(buf, end, "\"", str_spec); 2133 2134 has_mult = true; 2135 } 2136 break; 2137 default: 2138 break; 2139 } 2140 } 2141 2142 return widen_string(buf, buf - buf_start, end, spec); 2143 } 2144 2145 static noinline_for_stack 2146 char *fwnode_string(char *buf, char *end, struct fwnode_handle *fwnode, 2147 struct printf_spec spec, const char *fmt) 2148 { 2149 struct printf_spec str_spec = spec; 2150 char *buf_start = buf; 2151 2152 str_spec.field_width = -1; 2153 2154 if (*fmt != 'w') 2155 return error_string(buf, end, "(%pf?)", spec); 2156 2157 if (check_pointer(&buf, end, fwnode, spec)) 2158 return buf; 2159 2160 fmt++; 2161 2162 switch (*fmt) { 2163 case 'P': /* name */ 2164 buf = string(buf, end, fwnode_get_name(fwnode), str_spec); 2165 break; 2166 case 'f': /* full_name */ 2167 default: 2168 buf = fwnode_full_name_string(fwnode, buf, end); 2169 break; 2170 } 2171 2172 return widen_string(buf, buf - buf_start, end, spec); 2173 } 2174 2175 /* Disable pointer hashing if requested */ 2176 bool no_hash_pointers __ro_after_init; 2177 EXPORT_SYMBOL_GPL(no_hash_pointers); 2178 2179 static int __init no_hash_pointers_enable(char *str) 2180 { 2181 if (no_hash_pointers) 2182 return 0; 2183 2184 no_hash_pointers = true; 2185 2186 pr_warn("**********************************************************\n"); 2187 pr_warn("** NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE **\n"); 2188 pr_warn("** **\n"); 2189 pr_warn("** This system shows unhashed kernel memory addresses **\n"); 2190 pr_warn("** via the console, logs, and other interfaces. This **\n"); 2191 pr_warn("** might reduce the security of your system. **\n"); 2192 pr_warn("** **\n"); 2193 pr_warn("** If you see this message and you are not debugging **\n"); 2194 pr_warn("** the kernel, report this immediately to your system **\n"); 2195 pr_warn("** administrator! **\n"); 2196 pr_warn("** **\n"); 2197 pr_warn("** NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE **\n"); 2198 pr_warn("**********************************************************\n"); 2199 2200 return 0; 2201 } 2202 early_param("no_hash_pointers", no_hash_pointers_enable); 2203 2204 /* 2205 * Show a '%p' thing. A kernel extension is that the '%p' is followed 2206 * by an extra set of alphanumeric characters that are extended format 2207 * specifiers. 2208 * 2209 * Please update scripts/checkpatch.pl when adding/removing conversion 2210 * characters. (Search for "check for vsprintf extension"). 2211 * 2212 * Right now we handle: 2213 * 2214 * - 'S' For symbolic direct pointers (or function descriptors) with offset 2215 * - 's' For symbolic direct pointers (or function descriptors) without offset 2216 * - '[Ss]R' as above with __builtin_extract_return_addr() translation 2217 * - '[Ff]' %pf and %pF were obsoleted and later removed in favor of 2218 * %ps and %pS. Be careful when re-using these specifiers. 2219 * - 'B' For backtraced symbolic direct pointers with offset 2220 * - 'R' For decoded struct resource, e.g., [mem 0x0-0x1f 64bit pref] 2221 * - 'r' For raw struct resource, e.g., [mem 0x0-0x1f flags 0x201] 2222 * - 'b[l]' For a bitmap, the number of bits is determined by the field 2223 * width which must be explicitly specified either as part of the 2224 * format string '%32b[l]' or through '%*b[l]', [l] selects 2225 * range-list format instead of hex format 2226 * - 'M' For a 6-byte MAC address, it prints the address in the 2227 * usual colon-separated hex notation 2228 * - 'm' For a 6-byte MAC address, it prints the hex address without colons 2229 * - 'MF' For a 6-byte MAC FDDI address, it prints the address 2230 * with a dash-separated hex notation 2231 * - '[mM]R' For a 6-byte MAC address, Reverse order (Bluetooth) 2232 * - 'I' [46] for IPv4/IPv6 addresses printed in the usual way 2233 * IPv4 uses dot-separated decimal without leading 0's (1.2.3.4) 2234 * IPv6 uses colon separated network-order 16 bit hex with leading 0's 2235 * [S][pfs] 2236 * Generic IPv4/IPv6 address (struct sockaddr *) that falls back to 2237 * [4] or [6] and is able to print port [p], flowinfo [f], scope [s] 2238 * - 'i' [46] for 'raw' IPv4/IPv6 addresses 2239 * IPv6 omits the colons (01020304...0f) 2240 * IPv4 uses dot-separated decimal with leading 0's (010.123.045.006) 2241 * [S][pfs] 2242 * Generic IPv4/IPv6 address (struct sockaddr *) that falls back to 2243 * [4] or [6] and is able to print port [p], flowinfo [f], scope [s] 2244 * - '[Ii][4S][hnbl]' IPv4 addresses in host, network, big or little endian order 2245 * - 'I[6S]c' for IPv6 addresses printed as specified by 2246 * https://tools.ietf.org/html/rfc5952 2247 * - 'E[achnops]' For an escaped buffer, where rules are defined by combination 2248 * of the following flags (see string_escape_mem() for the 2249 * details): 2250 * a - ESCAPE_ANY 2251 * c - ESCAPE_SPECIAL 2252 * h - ESCAPE_HEX 2253 * n - ESCAPE_NULL 2254 * o - ESCAPE_OCTAL 2255 * p - ESCAPE_NP 2256 * s - ESCAPE_SPACE 2257 * By default ESCAPE_ANY_NP is used. 2258 * - 'U' For a 16 byte UUID/GUID, it prints the UUID/GUID in the form 2259 * "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx" 2260 * Options for %pU are: 2261 * b big endian lower case hex (default) 2262 * B big endian UPPER case hex 2263 * l little endian lower case hex 2264 * L little endian UPPER case hex 2265 * big endian output byte order is: 2266 * [0][1][2][3]-[4][5]-[6][7]-[8][9]-[10][11][12][13][14][15] 2267 * little endian output byte order is: 2268 * [3][2][1][0]-[5][4]-[7][6]-[8][9]-[10][11][12][13][14][15] 2269 * - 'V' For a struct va_format which contains a format string * and va_list *, 2270 * call vsnprintf(->format, *->va_list). 2271 * Implements a "recursive vsnprintf". 2272 * Do not use this feature without some mechanism to verify the 2273 * correctness of the format string and va_list arguments. 2274 * - 'K' For a kernel pointer that should be hidden from unprivileged users. 2275 * Use only for procfs, sysfs and similar files, not printk(); please 2276 * read the documentation (path below) first. 2277 * - 'NF' For a netdev_features_t 2278 * - 'h[CDN]' For a variable-length buffer, it prints it as a hex string with 2279 * a certain separator (' ' by default): 2280 * C colon 2281 * D dash 2282 * N no separator 2283 * The maximum supported length is 64 bytes of the input. Consider 2284 * to use print_hex_dump() for the larger input. 2285 * - 'a[pd]' For address types [p] phys_addr_t, [d] dma_addr_t and derivatives 2286 * (default assumed to be phys_addr_t, passed by reference) 2287 * - 'd[234]' For a dentry name (optionally 2-4 last components) 2288 * - 'D[234]' Same as 'd' but for a struct file 2289 * - 'g' For block_device name (gendisk + partition number) 2290 * - 't[RT][dt][r]' For time and date as represented by: 2291 * R struct rtc_time 2292 * T time64_t 2293 * - 'C' For a clock, it prints the name (Common Clock Framework) or address 2294 * (legacy clock framework) of the clock 2295 * - 'Cn' For a clock, it prints the name (Common Clock Framework) or address 2296 * (legacy clock framework) of the clock 2297 * - 'G' For flags to be printed as a collection of symbolic strings that would 2298 * construct the specific value. Supported flags given by option: 2299 * p page flags (see struct page) given as pointer to unsigned long 2300 * g gfp flags (GFP_* and __GFP_*) given as pointer to gfp_t 2301 * v vma flags (VM_*) given as pointer to unsigned long 2302 * - 'OF[fnpPcCF]' For a device tree object 2303 * Without any optional arguments prints the full_name 2304 * f device node full_name 2305 * n device node name 2306 * p device node phandle 2307 * P device node path spec (name + @unit) 2308 * F device node flags 2309 * c major compatible string 2310 * C full compatible string 2311 * - 'fw[fP]' For a firmware node (struct fwnode_handle) pointer 2312 * Without an option prints the full name of the node 2313 * f full name 2314 * P node name, including a possible unit address 2315 * - 'x' For printing the address unmodified. Equivalent to "%lx". 2316 * Please read the documentation (path below) before using! 2317 * - '[ku]s' For a BPF/tracing related format specifier, e.g. used out of 2318 * bpf_trace_printk() where [ku] prefix specifies either kernel (k) 2319 * or user (u) memory to probe, and: 2320 * s a string, equivalent to "%s" on direct vsnprintf() use 2321 * 2322 * ** When making changes please also update: 2323 * Documentation/core-api/printk-formats.rst 2324 * 2325 * Note: The default behaviour (unadorned %p) is to hash the address, 2326 * rendering it useful as a unique identifier. 2327 */ 2328 static noinline_for_stack 2329 char *pointer(const char *fmt, char *buf, char *end, void *ptr, 2330 struct printf_spec spec) 2331 { 2332 switch (*fmt) { 2333 case 'S': 2334 case 's': 2335 ptr = dereference_symbol_descriptor(ptr); 2336 fallthrough; 2337 case 'B': 2338 return symbol_string(buf, end, ptr, spec, fmt); 2339 case 'R': 2340 case 'r': 2341 return resource_string(buf, end, ptr, spec, fmt); 2342 case 'h': 2343 return hex_string(buf, end, ptr, spec, fmt); 2344 case 'b': 2345 switch (fmt[1]) { 2346 case 'l': 2347 return bitmap_list_string(buf, end, ptr, spec, fmt); 2348 default: 2349 return bitmap_string(buf, end, ptr, spec, fmt); 2350 } 2351 case 'M': /* Colon separated: 00:01:02:03:04:05 */ 2352 case 'm': /* Contiguous: 000102030405 */ 2353 /* [mM]F (FDDI) */ 2354 /* [mM]R (Reverse order; Bluetooth) */ 2355 return mac_address_string(buf, end, ptr, spec, fmt); 2356 case 'I': /* Formatted IP supported 2357 * 4: 1.2.3.4 2358 * 6: 0001:0203:...:0708 2359 * 6c: 1::708 or 1::1.2.3.4 2360 */ 2361 case 'i': /* Contiguous: 2362 * 4: 001.002.003.004 2363 * 6: 000102...0f 2364 */ 2365 return ip_addr_string(buf, end, ptr, spec, fmt); 2366 case 'E': 2367 return escaped_string(buf, end, ptr, spec, fmt); 2368 case 'U': 2369 return uuid_string(buf, end, ptr, spec, fmt); 2370 case 'V': 2371 return va_format(buf, end, ptr, spec, fmt); 2372 case 'K': 2373 return restricted_pointer(buf, end, ptr, spec); 2374 case 'N': 2375 return netdev_bits(buf, end, ptr, spec, fmt); 2376 case 'a': 2377 return address_val(buf, end, ptr, spec, fmt); 2378 case 'd': 2379 return dentry_name(buf, end, ptr, spec, fmt); 2380 case 't': 2381 return time_and_date(buf, end, ptr, spec, fmt); 2382 case 'C': 2383 return clock(buf, end, ptr, spec, fmt); 2384 case 'D': 2385 return file_dentry_name(buf, end, ptr, spec, fmt); 2386 #ifdef CONFIG_BLOCK 2387 case 'g': 2388 return bdev_name(buf, end, ptr, spec, fmt); 2389 #endif 2390 2391 case 'G': 2392 return flags_string(buf, end, ptr, spec, fmt); 2393 case 'O': 2394 return device_node_string(buf, end, ptr, spec, fmt + 1); 2395 case 'f': 2396 return fwnode_string(buf, end, ptr, spec, fmt + 1); 2397 case 'x': 2398 return pointer_string(buf, end, ptr, spec); 2399 case 'e': 2400 /* %pe with a non-ERR_PTR gets treated as plain %p */ 2401 if (!IS_ERR(ptr)) 2402 break; 2403 return err_ptr(buf, end, ptr, spec); 2404 case 'u': 2405 case 'k': 2406 switch (fmt[1]) { 2407 case 's': 2408 return string(buf, end, ptr, spec); 2409 default: 2410 return error_string(buf, end, "(einval)", spec); 2411 } 2412 } 2413 2414 /* 2415 * default is to _not_ leak addresses, so hash before printing, 2416 * unless no_hash_pointers is specified on the command line. 2417 */ 2418 if (unlikely(no_hash_pointers)) 2419 return pointer_string(buf, end, ptr, spec); 2420 else 2421 return ptr_to_id(buf, end, ptr, spec); 2422 } 2423 2424 /* 2425 * Helper function to decode printf style format. 2426 * Each call decode a token from the format and return the 2427 * number of characters read (or likely the delta where it wants 2428 * to go on the next call). 2429 * The decoded token is returned through the parameters 2430 * 2431 * 'h', 'l', or 'L' for integer fields 2432 * 'z' support added 23/7/1999 S.H. 2433 * 'z' changed to 'Z' --davidm 1/25/99 2434 * 'Z' changed to 'z' --adobriyan 2017-01-25 2435 * 't' added for ptrdiff_t 2436 * 2437 * @fmt: the format string 2438 * @type of the token returned 2439 * @flags: various flags such as +, -, # tokens.. 2440 * @field_width: overwritten width 2441 * @base: base of the number (octal, hex, ...) 2442 * @precision: precision of a number 2443 * @qualifier: qualifier of a number (long, size_t, ...) 2444 */ 2445 static noinline_for_stack 2446 int format_decode(const char *fmt, struct printf_spec *spec) 2447 { 2448 const char *start = fmt; 2449 char qualifier; 2450 2451 /* we finished early by reading the field width */ 2452 if (spec->type == FORMAT_TYPE_WIDTH) { 2453 if (spec->field_width < 0) { 2454 spec->field_width = -spec->field_width; 2455 spec->flags |= LEFT; 2456 } 2457 spec->type = FORMAT_TYPE_NONE; 2458 goto precision; 2459 } 2460 2461 /* we finished early by reading the precision */ 2462 if (spec->type == FORMAT_TYPE_PRECISION) { 2463 if (spec->precision < 0) 2464 spec->precision = 0; 2465 2466 spec->type = FORMAT_TYPE_NONE; 2467 goto qualifier; 2468 } 2469 2470 /* By default */ 2471 spec->type = FORMAT_TYPE_NONE; 2472 2473 for (; *fmt ; ++fmt) { 2474 if (*fmt == '%') 2475 break; 2476 } 2477 2478 /* Return the current non-format string */ 2479 if (fmt != start || !*fmt) 2480 return fmt - start; 2481 2482 /* Process flags */ 2483 spec->flags = 0; 2484 2485 while (1) { /* this also skips first '%' */ 2486 bool found = true; 2487 2488 ++fmt; 2489 2490 switch (*fmt) { 2491 case '-': spec->flags |= LEFT; break; 2492 case '+': spec->flags |= PLUS; break; 2493 case ' ': spec->flags |= SPACE; break; 2494 case '#': spec->flags |= SPECIAL; break; 2495 case '0': spec->flags |= ZEROPAD; break; 2496 default: found = false; 2497 } 2498 2499 if (!found) 2500 break; 2501 } 2502 2503 /* get field width */ 2504 spec->field_width = -1; 2505 2506 if (isdigit(*fmt)) 2507 spec->field_width = skip_atoi(&fmt); 2508 else if (*fmt == '*') { 2509 /* it's the next argument */ 2510 spec->type = FORMAT_TYPE_WIDTH; 2511 return ++fmt - start; 2512 } 2513 2514 precision: 2515 /* get the precision */ 2516 spec->precision = -1; 2517 if (*fmt == '.') { 2518 ++fmt; 2519 if (isdigit(*fmt)) { 2520 spec->precision = skip_atoi(&fmt); 2521 if (spec->precision < 0) 2522 spec->precision = 0; 2523 } else if (*fmt == '*') { 2524 /* it's the next argument */ 2525 spec->type = FORMAT_TYPE_PRECISION; 2526 return ++fmt - start; 2527 } 2528 } 2529 2530 qualifier: 2531 /* get the conversion qualifier */ 2532 qualifier = 0; 2533 if (*fmt == 'h' || _tolower(*fmt) == 'l' || 2534 *fmt == 'z' || *fmt == 't') { 2535 qualifier = *fmt++; 2536 if (unlikely(qualifier == *fmt)) { 2537 if (qualifier == 'l') { 2538 qualifier = 'L'; 2539 ++fmt; 2540 } else if (qualifier == 'h') { 2541 qualifier = 'H'; 2542 ++fmt; 2543 } 2544 } 2545 } 2546 2547 /* default base */ 2548 spec->base = 10; 2549 switch (*fmt) { 2550 case 'c': 2551 spec->type = FORMAT_TYPE_CHAR; 2552 return ++fmt - start; 2553 2554 case 's': 2555 spec->type = FORMAT_TYPE_STR; 2556 return ++fmt - start; 2557 2558 case 'p': 2559 spec->type = FORMAT_TYPE_PTR; 2560 return ++fmt - start; 2561 2562 case '%': 2563 spec->type = FORMAT_TYPE_PERCENT_CHAR; 2564 return ++fmt - start; 2565 2566 /* integer number formats - set up the flags and "break" */ 2567 case 'o': 2568 spec->base = 8; 2569 break; 2570 2571 case 'x': 2572 spec->flags |= SMALL; 2573 fallthrough; 2574 2575 case 'X': 2576 spec->base = 16; 2577 break; 2578 2579 case 'd': 2580 case 'i': 2581 spec->flags |= SIGN; 2582 break; 2583 case 'u': 2584 break; 2585 2586 case 'n': 2587 /* 2588 * Since %n poses a greater security risk than 2589 * utility, treat it as any other invalid or 2590 * unsupported format specifier. 2591 */ 2592 fallthrough; 2593 2594 default: 2595 WARN_ONCE(1, "Please remove unsupported %%%c in format string\n", *fmt); 2596 spec->type = FORMAT_TYPE_INVALID; 2597 return fmt - start; 2598 } 2599 2600 if (qualifier == 'L') 2601 spec->type = FORMAT_TYPE_LONG_LONG; 2602 else if (qualifier == 'l') { 2603 BUILD_BUG_ON(FORMAT_TYPE_ULONG + SIGN != FORMAT_TYPE_LONG); 2604 spec->type = FORMAT_TYPE_ULONG + (spec->flags & SIGN); 2605 } else if (qualifier == 'z') { 2606 spec->type = FORMAT_TYPE_SIZE_T; 2607 } else if (qualifier == 't') { 2608 spec->type = FORMAT_TYPE_PTRDIFF; 2609 } else if (qualifier == 'H') { 2610 BUILD_BUG_ON(FORMAT_TYPE_UBYTE + SIGN != FORMAT_TYPE_BYTE); 2611 spec->type = FORMAT_TYPE_UBYTE + (spec->flags & SIGN); 2612 } else if (qualifier == 'h') { 2613 BUILD_BUG_ON(FORMAT_TYPE_USHORT + SIGN != FORMAT_TYPE_SHORT); 2614 spec->type = FORMAT_TYPE_USHORT + (spec->flags & SIGN); 2615 } else { 2616 BUILD_BUG_ON(FORMAT_TYPE_UINT + SIGN != FORMAT_TYPE_INT); 2617 spec->type = FORMAT_TYPE_UINT + (spec->flags & SIGN); 2618 } 2619 2620 return ++fmt - start; 2621 } 2622 2623 static void 2624 set_field_width(struct printf_spec *spec, int width) 2625 { 2626 spec->field_width = width; 2627 if (WARN_ONCE(spec->field_width != width, "field width %d too large", width)) { 2628 spec->field_width = clamp(width, -FIELD_WIDTH_MAX, FIELD_WIDTH_MAX); 2629 } 2630 } 2631 2632 static void 2633 set_precision(struct printf_spec *spec, int prec) 2634 { 2635 spec->precision = prec; 2636 if (WARN_ONCE(spec->precision != prec, "precision %d too large", prec)) { 2637 spec->precision = clamp(prec, 0, PRECISION_MAX); 2638 } 2639 } 2640 2641 /** 2642 * vsnprintf - Format a string and place it in a buffer 2643 * @buf: The buffer to place the result into 2644 * @size: The size of the buffer, including the trailing null space 2645 * @fmt: The format string to use 2646 * @args: Arguments for the format string 2647 * 2648 * This function generally follows C99 vsnprintf, but has some 2649 * extensions and a few limitations: 2650 * 2651 * - ``%n`` is unsupported 2652 * - ``%p*`` is handled by pointer() 2653 * 2654 * See pointer() or Documentation/core-api/printk-formats.rst for more 2655 * extensive description. 2656 * 2657 * **Please update the documentation in both places when making changes** 2658 * 2659 * The return value is the number of characters which would 2660 * be generated for the given input, excluding the trailing 2661 * '\0', as per ISO C99. If you want to have the exact 2662 * number of characters written into @buf as return value 2663 * (not including the trailing '\0'), use vscnprintf(). If the 2664 * return is greater than or equal to @size, the resulting 2665 * string is truncated. 2666 * 2667 * If you're not already dealing with a va_list consider using snprintf(). 2668 */ 2669 int vsnprintf(char *buf, size_t size, const char *fmt, va_list args) 2670 { 2671 unsigned long long num; 2672 char *str, *end; 2673 struct printf_spec spec = {0}; 2674 2675 /* Reject out-of-range values early. Large positive sizes are 2676 used for unknown buffer sizes. */ 2677 if (WARN_ON_ONCE(size > INT_MAX)) 2678 return 0; 2679 2680 str = buf; 2681 end = buf + size; 2682 2683 /* Make sure end is always >= buf */ 2684 if (end < buf) { 2685 end = ((void *)-1); 2686 size = end - buf; 2687 } 2688 2689 while (*fmt) { 2690 const char *old_fmt = fmt; 2691 int read = format_decode(fmt, &spec); 2692 2693 fmt += read; 2694 2695 switch (spec.type) { 2696 case FORMAT_TYPE_NONE: { 2697 int copy = read; 2698 if (str < end) { 2699 if (copy > end - str) 2700 copy = end - str; 2701 memcpy(str, old_fmt, copy); 2702 } 2703 str += read; 2704 break; 2705 } 2706 2707 case FORMAT_TYPE_WIDTH: 2708 set_field_width(&spec, va_arg(args, int)); 2709 break; 2710 2711 case FORMAT_TYPE_PRECISION: 2712 set_precision(&spec, va_arg(args, int)); 2713 break; 2714 2715 case FORMAT_TYPE_CHAR: { 2716 char c; 2717 2718 if (!(spec.flags & LEFT)) { 2719 while (--spec.field_width > 0) { 2720 if (str < end) 2721 *str = ' '; 2722 ++str; 2723 2724 } 2725 } 2726 c = (unsigned char) va_arg(args, int); 2727 if (str < end) 2728 *str = c; 2729 ++str; 2730 while (--spec.field_width > 0) { 2731 if (str < end) 2732 *str = ' '; 2733 ++str; 2734 } 2735 break; 2736 } 2737 2738 case FORMAT_TYPE_STR: 2739 str = string(str, end, va_arg(args, char *), spec); 2740 break; 2741 2742 case FORMAT_TYPE_PTR: 2743 str = pointer(fmt, str, end, va_arg(args, void *), 2744 spec); 2745 while (isalnum(*fmt)) 2746 fmt++; 2747 break; 2748 2749 case FORMAT_TYPE_PERCENT_CHAR: 2750 if (str < end) 2751 *str = '%'; 2752 ++str; 2753 break; 2754 2755 case FORMAT_TYPE_INVALID: 2756 /* 2757 * Presumably the arguments passed gcc's type 2758 * checking, but there is no safe or sane way 2759 * for us to continue parsing the format and 2760 * fetching from the va_list; the remaining 2761 * specifiers and arguments would be out of 2762 * sync. 2763 */ 2764 goto out; 2765 2766 default: 2767 switch (spec.type) { 2768 case FORMAT_TYPE_LONG_LONG: 2769 num = va_arg(args, long long); 2770 break; 2771 case FORMAT_TYPE_ULONG: 2772 num = va_arg(args, unsigned long); 2773 break; 2774 case FORMAT_TYPE_LONG: 2775 num = va_arg(args, long); 2776 break; 2777 case FORMAT_TYPE_SIZE_T: 2778 if (spec.flags & SIGN) 2779 num = va_arg(args, ssize_t); 2780 else 2781 num = va_arg(args, size_t); 2782 break; 2783 case FORMAT_TYPE_PTRDIFF: 2784 num = va_arg(args, ptrdiff_t); 2785 break; 2786 case FORMAT_TYPE_UBYTE: 2787 num = (unsigned char) va_arg(args, int); 2788 break; 2789 case FORMAT_TYPE_BYTE: 2790 num = (signed char) va_arg(args, int); 2791 break; 2792 case FORMAT_TYPE_USHORT: 2793 num = (unsigned short) va_arg(args, int); 2794 break; 2795 case FORMAT_TYPE_SHORT: 2796 num = (short) va_arg(args, int); 2797 break; 2798 case FORMAT_TYPE_INT: 2799 num = (int) va_arg(args, int); 2800 break; 2801 default: 2802 num = va_arg(args, unsigned int); 2803 } 2804 2805 str = number(str, end, num, spec); 2806 } 2807 } 2808 2809 out: 2810 if (size > 0) { 2811 if (str < end) 2812 *str = '\0'; 2813 else 2814 end[-1] = '\0'; 2815 } 2816 2817 /* the trailing null byte doesn't count towards the total */ 2818 return str-buf; 2819 2820 } 2821 EXPORT_SYMBOL(vsnprintf); 2822 2823 /** 2824 * vscnprintf - Format a string and place it in a buffer 2825 * @buf: The buffer to place the result into 2826 * @size: The size of the buffer, including the trailing null space 2827 * @fmt: The format string to use 2828 * @args: Arguments for the format string 2829 * 2830 * The return value is the number of characters which have been written into 2831 * the @buf not including the trailing '\0'. If @size is == 0 the function 2832 * returns 0. 2833 * 2834 * If you're not already dealing with a va_list consider using scnprintf(). 2835 * 2836 * See the vsnprintf() documentation for format string extensions over C99. 2837 */ 2838 int vscnprintf(char *buf, size_t size, const char *fmt, va_list args) 2839 { 2840 int i; 2841 2842 i = vsnprintf(buf, size, fmt, args); 2843 2844 if (likely(i < size)) 2845 return i; 2846 if (size != 0) 2847 return size - 1; 2848 return 0; 2849 } 2850 EXPORT_SYMBOL(vscnprintf); 2851 2852 /** 2853 * snprintf - Format a string and place it in a buffer 2854 * @buf: The buffer to place the result into 2855 * @size: The size of the buffer, including the trailing null space 2856 * @fmt: The format string to use 2857 * @...: Arguments for the format string 2858 * 2859 * The return value is the number of characters which would be 2860 * generated for the given input, excluding the trailing null, 2861 * as per ISO C99. If the return is greater than or equal to 2862 * @size, the resulting string is truncated. 2863 * 2864 * See the vsnprintf() documentation for format string extensions over C99. 2865 */ 2866 int snprintf(char *buf, size_t size, const char *fmt, ...) 2867 { 2868 va_list args; 2869 int i; 2870 2871 va_start(args, fmt); 2872 i = vsnprintf(buf, size, fmt, args); 2873 va_end(args); 2874 2875 return i; 2876 } 2877 EXPORT_SYMBOL(snprintf); 2878 2879 /** 2880 * scnprintf - Format a string and place it in a buffer 2881 * @buf: The buffer to place the result into 2882 * @size: The size of the buffer, including the trailing null space 2883 * @fmt: The format string to use 2884 * @...: Arguments for the format string 2885 * 2886 * The return value is the number of characters written into @buf not including 2887 * the trailing '\0'. If @size is == 0 the function returns 0. 2888 */ 2889 2890 int scnprintf(char *buf, size_t size, const char *fmt, ...) 2891 { 2892 va_list args; 2893 int i; 2894 2895 va_start(args, fmt); 2896 i = vscnprintf(buf, size, fmt, args); 2897 va_end(args); 2898 2899 return i; 2900 } 2901 EXPORT_SYMBOL(scnprintf); 2902 2903 /** 2904 * vsprintf - Format a string and place it in a buffer 2905 * @buf: The buffer to place the result into 2906 * @fmt: The format string to use 2907 * @args: Arguments for the format string 2908 * 2909 * The function returns the number of characters written 2910 * into @buf. Use vsnprintf() or vscnprintf() in order to avoid 2911 * buffer overflows. 2912 * 2913 * If you're not already dealing with a va_list consider using sprintf(). 2914 * 2915 * See the vsnprintf() documentation for format string extensions over C99. 2916 */ 2917 int vsprintf(char *buf, const char *fmt, va_list args) 2918 { 2919 return vsnprintf(buf, INT_MAX, fmt, args); 2920 } 2921 EXPORT_SYMBOL(vsprintf); 2922 2923 /** 2924 * sprintf - Format a string and place it in a buffer 2925 * @buf: The buffer to place the result into 2926 * @fmt: The format string to use 2927 * @...: Arguments for the format string 2928 * 2929 * The function returns the number of characters written 2930 * into @buf. Use snprintf() or scnprintf() in order to avoid 2931 * buffer overflows. 2932 * 2933 * See the vsnprintf() documentation for format string extensions over C99. 2934 */ 2935 int sprintf(char *buf, const char *fmt, ...) 2936 { 2937 va_list args; 2938 int i; 2939 2940 va_start(args, fmt); 2941 i = vsnprintf(buf, INT_MAX, fmt, args); 2942 va_end(args); 2943 2944 return i; 2945 } 2946 EXPORT_SYMBOL(sprintf); 2947 2948 #ifdef CONFIG_BINARY_PRINTF 2949 /* 2950 * bprintf service: 2951 * vbin_printf() - VA arguments to binary data 2952 * bstr_printf() - Binary data to text string 2953 */ 2954 2955 /** 2956 * vbin_printf - Parse a format string and place args' binary value in a buffer 2957 * @bin_buf: The buffer to place args' binary value 2958 * @size: The size of the buffer(by words(32bits), not characters) 2959 * @fmt: The format string to use 2960 * @args: Arguments for the format string 2961 * 2962 * The format follows C99 vsnprintf, except %n is ignored, and its argument 2963 * is skipped. 2964 * 2965 * The return value is the number of words(32bits) which would be generated for 2966 * the given input. 2967 * 2968 * NOTE: 2969 * If the return value is greater than @size, the resulting bin_buf is NOT 2970 * valid for bstr_printf(). 2971 */ 2972 int vbin_printf(u32 *bin_buf, size_t size, const char *fmt, va_list args) 2973 { 2974 struct printf_spec spec = {0}; 2975 char *str, *end; 2976 int width; 2977 2978 str = (char *)bin_buf; 2979 end = (char *)(bin_buf + size); 2980 2981 #define save_arg(type) \ 2982 ({ \ 2983 unsigned long long value; \ 2984 if (sizeof(type) == 8) { \ 2985 unsigned long long val8; \ 2986 str = PTR_ALIGN(str, sizeof(u32)); \ 2987 val8 = va_arg(args, unsigned long long); \ 2988 if (str + sizeof(type) <= end) { \ 2989 *(u32 *)str = *(u32 *)&val8; \ 2990 *(u32 *)(str + 4) = *((u32 *)&val8 + 1); \ 2991 } \ 2992 value = val8; \ 2993 } else { \ 2994 unsigned int val4; \ 2995 str = PTR_ALIGN(str, sizeof(type)); \ 2996 val4 = va_arg(args, int); \ 2997 if (str + sizeof(type) <= end) \ 2998 *(typeof(type) *)str = (type)(long)val4; \ 2999 value = (unsigned long long)val4; \ 3000 } \ 3001 str += sizeof(type); \ 3002 value; \ 3003 }) 3004 3005 while (*fmt) { 3006 int read = format_decode(fmt, &spec); 3007 3008 fmt += read; 3009 3010 switch (spec.type) { 3011 case FORMAT_TYPE_NONE: 3012 case FORMAT_TYPE_PERCENT_CHAR: 3013 break; 3014 case FORMAT_TYPE_INVALID: 3015 goto out; 3016 3017 case FORMAT_TYPE_WIDTH: 3018 case FORMAT_TYPE_PRECISION: 3019 width = (int)save_arg(int); 3020 /* Pointers may require the width */ 3021 if (*fmt == 'p') 3022 set_field_width(&spec, width); 3023 break; 3024 3025 case FORMAT_TYPE_CHAR: 3026 save_arg(char); 3027 break; 3028 3029 case FORMAT_TYPE_STR: { 3030 const char *save_str = va_arg(args, char *); 3031 const char *err_msg; 3032 size_t len; 3033 3034 err_msg = check_pointer_msg(save_str); 3035 if (err_msg) 3036 save_str = err_msg; 3037 3038 len = strlen(save_str) + 1; 3039 if (str + len < end) 3040 memcpy(str, save_str, len); 3041 str += len; 3042 break; 3043 } 3044 3045 case FORMAT_TYPE_PTR: 3046 /* Dereferenced pointers must be done now */ 3047 switch (*fmt) { 3048 /* Dereference of functions is still OK */ 3049 case 'S': 3050 case 's': 3051 case 'x': 3052 case 'K': 3053 case 'e': 3054 save_arg(void *); 3055 break; 3056 default: 3057 if (!isalnum(*fmt)) { 3058 save_arg(void *); 3059 break; 3060 } 3061 str = pointer(fmt, str, end, va_arg(args, void *), 3062 spec); 3063 if (str + 1 < end) 3064 *str++ = '\0'; 3065 else 3066 end[-1] = '\0'; /* Must be nul terminated */ 3067 } 3068 /* skip all alphanumeric pointer suffixes */ 3069 while (isalnum(*fmt)) 3070 fmt++; 3071 break; 3072 3073 default: 3074 switch (spec.type) { 3075 3076 case FORMAT_TYPE_LONG_LONG: 3077 save_arg(long long); 3078 break; 3079 case FORMAT_TYPE_ULONG: 3080 case FORMAT_TYPE_LONG: 3081 save_arg(unsigned long); 3082 break; 3083 case FORMAT_TYPE_SIZE_T: 3084 save_arg(size_t); 3085 break; 3086 case FORMAT_TYPE_PTRDIFF: 3087 save_arg(ptrdiff_t); 3088 break; 3089 case FORMAT_TYPE_UBYTE: 3090 case FORMAT_TYPE_BYTE: 3091 save_arg(char); 3092 break; 3093 case FORMAT_TYPE_USHORT: 3094 case FORMAT_TYPE_SHORT: 3095 save_arg(short); 3096 break; 3097 default: 3098 save_arg(int); 3099 } 3100 } 3101 } 3102 3103 out: 3104 return (u32 *)(PTR_ALIGN(str, sizeof(u32))) - bin_buf; 3105 #undef save_arg 3106 } 3107 EXPORT_SYMBOL_GPL(vbin_printf); 3108 3109 /** 3110 * bstr_printf - Format a string from binary arguments and place it in a buffer 3111 * @buf: The buffer to place the result into 3112 * @size: The size of the buffer, including the trailing null space 3113 * @fmt: The format string to use 3114 * @bin_buf: Binary arguments for the format string 3115 * 3116 * This function like C99 vsnprintf, but the difference is that vsnprintf gets 3117 * arguments from stack, and bstr_printf gets arguments from @bin_buf which is 3118 * a binary buffer that generated by vbin_printf. 3119 * 3120 * The format follows C99 vsnprintf, but has some extensions: 3121 * see vsnprintf comment for details. 3122 * 3123 * The return value is the number of characters which would 3124 * be generated for the given input, excluding the trailing 3125 * '\0', as per ISO C99. If you want to have the exact 3126 * number of characters written into @buf as return value 3127 * (not including the trailing '\0'), use vscnprintf(). If the 3128 * return is greater than or equal to @size, the resulting 3129 * string is truncated. 3130 */ 3131 int bstr_printf(char *buf, size_t size, const char *fmt, const u32 *bin_buf) 3132 { 3133 struct printf_spec spec = {0}; 3134 char *str, *end; 3135 const char *args = (const char *)bin_buf; 3136 3137 if (WARN_ON_ONCE(size > INT_MAX)) 3138 return 0; 3139 3140 str = buf; 3141 end = buf + size; 3142 3143 #define get_arg(type) \ 3144 ({ \ 3145 typeof(type) value; \ 3146 if (sizeof(type) == 8) { \ 3147 args = PTR_ALIGN(args, sizeof(u32)); \ 3148 *(u32 *)&value = *(u32 *)args; \ 3149 *((u32 *)&value + 1) = *(u32 *)(args + 4); \ 3150 } else { \ 3151 args = PTR_ALIGN(args, sizeof(type)); \ 3152 value = *(typeof(type) *)args; \ 3153 } \ 3154 args += sizeof(type); \ 3155 value; \ 3156 }) 3157 3158 /* Make sure end is always >= buf */ 3159 if (end < buf) { 3160 end = ((void *)-1); 3161 size = end - buf; 3162 } 3163 3164 while (*fmt) { 3165 const char *old_fmt = fmt; 3166 int read = format_decode(fmt, &spec); 3167 3168 fmt += read; 3169 3170 switch (spec.type) { 3171 case FORMAT_TYPE_NONE: { 3172 int copy = read; 3173 if (str < end) { 3174 if (copy > end - str) 3175 copy = end - str; 3176 memcpy(str, old_fmt, copy); 3177 } 3178 str += read; 3179 break; 3180 } 3181 3182 case FORMAT_TYPE_WIDTH: 3183 set_field_width(&spec, get_arg(int)); 3184 break; 3185 3186 case FORMAT_TYPE_PRECISION: 3187 set_precision(&spec, get_arg(int)); 3188 break; 3189 3190 case FORMAT_TYPE_CHAR: { 3191 char c; 3192 3193 if (!(spec.flags & LEFT)) { 3194 while (--spec.field_width > 0) { 3195 if (str < end) 3196 *str = ' '; 3197 ++str; 3198 } 3199 } 3200 c = (unsigned char) get_arg(char); 3201 if (str < end) 3202 *str = c; 3203 ++str; 3204 while (--spec.field_width > 0) { 3205 if (str < end) 3206 *str = ' '; 3207 ++str; 3208 } 3209 break; 3210 } 3211 3212 case FORMAT_TYPE_STR: { 3213 const char *str_arg = args; 3214 args += strlen(str_arg) + 1; 3215 str = string(str, end, (char *)str_arg, spec); 3216 break; 3217 } 3218 3219 case FORMAT_TYPE_PTR: { 3220 bool process = false; 3221 int copy, len; 3222 /* Non function dereferences were already done */ 3223 switch (*fmt) { 3224 case 'S': 3225 case 's': 3226 case 'x': 3227 case 'K': 3228 case 'e': 3229 process = true; 3230 break; 3231 default: 3232 if (!isalnum(*fmt)) { 3233 process = true; 3234 break; 3235 } 3236 /* Pointer dereference was already processed */ 3237 if (str < end) { 3238 len = copy = strlen(args); 3239 if (copy > end - str) 3240 copy = end - str; 3241 memcpy(str, args, copy); 3242 str += len; 3243 args += len + 1; 3244 } 3245 } 3246 if (process) 3247 str = pointer(fmt, str, end, get_arg(void *), spec); 3248 3249 while (isalnum(*fmt)) 3250 fmt++; 3251 break; 3252 } 3253 3254 case FORMAT_TYPE_PERCENT_CHAR: 3255 if (str < end) 3256 *str = '%'; 3257 ++str; 3258 break; 3259 3260 case FORMAT_TYPE_INVALID: 3261 goto out; 3262 3263 default: { 3264 unsigned long long num; 3265 3266 switch (spec.type) { 3267 3268 case FORMAT_TYPE_LONG_LONG: 3269 num = get_arg(long long); 3270 break; 3271 case FORMAT_TYPE_ULONG: 3272 case FORMAT_TYPE_LONG: 3273 num = get_arg(unsigned long); 3274 break; 3275 case FORMAT_TYPE_SIZE_T: 3276 num = get_arg(size_t); 3277 break; 3278 case FORMAT_TYPE_PTRDIFF: 3279 num = get_arg(ptrdiff_t); 3280 break; 3281 case FORMAT_TYPE_UBYTE: 3282 num = get_arg(unsigned char); 3283 break; 3284 case FORMAT_TYPE_BYTE: 3285 num = get_arg(signed char); 3286 break; 3287 case FORMAT_TYPE_USHORT: 3288 num = get_arg(unsigned short); 3289 break; 3290 case FORMAT_TYPE_SHORT: 3291 num = get_arg(short); 3292 break; 3293 case FORMAT_TYPE_UINT: 3294 num = get_arg(unsigned int); 3295 break; 3296 default: 3297 num = get_arg(int); 3298 } 3299 3300 str = number(str, end, num, spec); 3301 } /* default: */ 3302 } /* switch(spec.type) */ 3303 } /* while(*fmt) */ 3304 3305 out: 3306 if (size > 0) { 3307 if (str < end) 3308 *str = '\0'; 3309 else 3310 end[-1] = '\0'; 3311 } 3312 3313 #undef get_arg 3314 3315 /* the trailing null byte doesn't count towards the total */ 3316 return str - buf; 3317 } 3318 EXPORT_SYMBOL_GPL(bstr_printf); 3319 3320 /** 3321 * bprintf - Parse a format string and place args' binary value in a buffer 3322 * @bin_buf: The buffer to place args' binary value 3323 * @size: The size of the buffer(by words(32bits), not characters) 3324 * @fmt: The format string to use 3325 * @...: Arguments for the format string 3326 * 3327 * The function returns the number of words(u32) written 3328 * into @bin_buf. 3329 */ 3330 int bprintf(u32 *bin_buf, size_t size, const char *fmt, ...) 3331 { 3332 va_list args; 3333 int ret; 3334 3335 va_start(args, fmt); 3336 ret = vbin_printf(bin_buf, size, fmt, args); 3337 va_end(args); 3338 3339 return ret; 3340 } 3341 EXPORT_SYMBOL_GPL(bprintf); 3342 3343 #endif /* CONFIG_BINARY_PRINTF */ 3344 3345 /** 3346 * vsscanf - Unformat a buffer into a list of arguments 3347 * @buf: input buffer 3348 * @fmt: format of buffer 3349 * @args: arguments 3350 */ 3351 int vsscanf(const char *buf, const char *fmt, va_list args) 3352 { 3353 const char *str = buf; 3354 char *next; 3355 char digit; 3356 int num = 0; 3357 u8 qualifier; 3358 unsigned int base; 3359 union { 3360 long long s; 3361 unsigned long long u; 3362 } val; 3363 s16 field_width; 3364 bool is_sign; 3365 3366 while (*fmt) { 3367 /* skip any white space in format */ 3368 /* white space in format matchs any amount of 3369 * white space, including none, in the input. 3370 */ 3371 if (isspace(*fmt)) { 3372 fmt = skip_spaces(++fmt); 3373 str = skip_spaces(str); 3374 } 3375 3376 /* anything that is not a conversion must match exactly */ 3377 if (*fmt != '%' && *fmt) { 3378 if (*fmt++ != *str++) 3379 break; 3380 continue; 3381 } 3382 3383 if (!*fmt) 3384 break; 3385 ++fmt; 3386 3387 /* skip this conversion. 3388 * advance both strings to next white space 3389 */ 3390 if (*fmt == '*') { 3391 if (!*str) 3392 break; 3393 while (!isspace(*fmt) && *fmt != '%' && *fmt) { 3394 /* '%*[' not yet supported, invalid format */ 3395 if (*fmt == '[') 3396 return num; 3397 fmt++; 3398 } 3399 while (!isspace(*str) && *str) 3400 str++; 3401 continue; 3402 } 3403 3404 /* get field width */ 3405 field_width = -1; 3406 if (isdigit(*fmt)) { 3407 field_width = skip_atoi(&fmt); 3408 if (field_width <= 0) 3409 break; 3410 } 3411 3412 /* get conversion qualifier */ 3413 qualifier = -1; 3414 if (*fmt == 'h' || _tolower(*fmt) == 'l' || 3415 *fmt == 'z') { 3416 qualifier = *fmt++; 3417 if (unlikely(qualifier == *fmt)) { 3418 if (qualifier == 'h') { 3419 qualifier = 'H'; 3420 fmt++; 3421 } else if (qualifier == 'l') { 3422 qualifier = 'L'; 3423 fmt++; 3424 } 3425 } 3426 } 3427 3428 if (!*fmt) 3429 break; 3430 3431 if (*fmt == 'n') { 3432 /* return number of characters read so far */ 3433 *va_arg(args, int *) = str - buf; 3434 ++fmt; 3435 continue; 3436 } 3437 3438 if (!*str) 3439 break; 3440 3441 base = 10; 3442 is_sign = false; 3443 3444 switch (*fmt++) { 3445 case 'c': 3446 { 3447 char *s = (char *)va_arg(args, char*); 3448 if (field_width == -1) 3449 field_width = 1; 3450 do { 3451 *s++ = *str++; 3452 } while (--field_width > 0 && *str); 3453 num++; 3454 } 3455 continue; 3456 case 's': 3457 { 3458 char *s = (char *)va_arg(args, char *); 3459 if (field_width == -1) 3460 field_width = SHRT_MAX; 3461 /* first, skip leading white space in buffer */ 3462 str = skip_spaces(str); 3463 3464 /* now copy until next white space */ 3465 while (*str && !isspace(*str) && field_width--) 3466 *s++ = *str++; 3467 *s = '\0'; 3468 num++; 3469 } 3470 continue; 3471 /* 3472 * Warning: This implementation of the '[' conversion specifier 3473 * deviates from its glibc counterpart in the following ways: 3474 * (1) It does NOT support ranges i.e. '-' is NOT a special 3475 * character 3476 * (2) It cannot match the closing bracket ']' itself 3477 * (3) A field width is required 3478 * (4) '%*[' (discard matching input) is currently not supported 3479 * 3480 * Example usage: 3481 * ret = sscanf("00:0a:95","%2[^:]:%2[^:]:%2[^:]", 3482 * buf1, buf2, buf3); 3483 * if (ret < 3) 3484 * // etc.. 3485 */ 3486 case '[': 3487 { 3488 char *s = (char *)va_arg(args, char *); 3489 DECLARE_BITMAP(set, 256) = {0}; 3490 unsigned int len = 0; 3491 bool negate = (*fmt == '^'); 3492 3493 /* field width is required */ 3494 if (field_width == -1) 3495 return num; 3496 3497 if (negate) 3498 ++fmt; 3499 3500 for ( ; *fmt && *fmt != ']'; ++fmt, ++len) 3501 set_bit((u8)*fmt, set); 3502 3503 /* no ']' or no character set found */ 3504 if (!*fmt || !len) 3505 return num; 3506 ++fmt; 3507 3508 if (negate) { 3509 bitmap_complement(set, set, 256); 3510 /* exclude null '\0' byte */ 3511 clear_bit(0, set); 3512 } 3513 3514 /* match must be non-empty */ 3515 if (!test_bit((u8)*str, set)) 3516 return num; 3517 3518 while (test_bit((u8)*str, set) && field_width--) 3519 *s++ = *str++; 3520 *s = '\0'; 3521 ++num; 3522 } 3523 continue; 3524 case 'o': 3525 base = 8; 3526 break; 3527 case 'x': 3528 case 'X': 3529 base = 16; 3530 break; 3531 case 'i': 3532 base = 0; 3533 fallthrough; 3534 case 'd': 3535 is_sign = true; 3536 fallthrough; 3537 case 'u': 3538 break; 3539 case '%': 3540 /* looking for '%' in str */ 3541 if (*str++ != '%') 3542 return num; 3543 continue; 3544 default: 3545 /* invalid format; stop here */ 3546 return num; 3547 } 3548 3549 /* have some sort of integer conversion. 3550 * first, skip white space in buffer. 3551 */ 3552 str = skip_spaces(str); 3553 3554 digit = *str; 3555 if (is_sign && digit == '-') { 3556 if (field_width == 1) 3557 break; 3558 3559 digit = *(str + 1); 3560 } 3561 3562 if (!digit 3563 || (base == 16 && !isxdigit(digit)) 3564 || (base == 10 && !isdigit(digit)) 3565 || (base == 8 && (!isdigit(digit) || digit > '7')) 3566 || (base == 0 && !isdigit(digit))) 3567 break; 3568 3569 if (is_sign) 3570 val.s = simple_strntoll(str, 3571 field_width >= 0 ? field_width : INT_MAX, 3572 &next, base); 3573 else 3574 val.u = simple_strntoull(str, 3575 field_width >= 0 ? field_width : INT_MAX, 3576 &next, base); 3577 3578 switch (qualifier) { 3579 case 'H': /* that's 'hh' in format */ 3580 if (is_sign) 3581 *va_arg(args, signed char *) = val.s; 3582 else 3583 *va_arg(args, unsigned char *) = val.u; 3584 break; 3585 case 'h': 3586 if (is_sign) 3587 *va_arg(args, short *) = val.s; 3588 else 3589 *va_arg(args, unsigned short *) = val.u; 3590 break; 3591 case 'l': 3592 if (is_sign) 3593 *va_arg(args, long *) = val.s; 3594 else 3595 *va_arg(args, unsigned long *) = val.u; 3596 break; 3597 case 'L': 3598 if (is_sign) 3599 *va_arg(args, long long *) = val.s; 3600 else 3601 *va_arg(args, unsigned long long *) = val.u; 3602 break; 3603 case 'z': 3604 *va_arg(args, size_t *) = val.u; 3605 break; 3606 default: 3607 if (is_sign) 3608 *va_arg(args, int *) = val.s; 3609 else 3610 *va_arg(args, unsigned int *) = val.u; 3611 break; 3612 } 3613 num++; 3614 3615 if (!next) 3616 break; 3617 str = next; 3618 } 3619 3620 return num; 3621 } 3622 EXPORT_SYMBOL(vsscanf); 3623 3624 /** 3625 * sscanf - Unformat a buffer into a list of arguments 3626 * @buf: input buffer 3627 * @fmt: formatting of buffer 3628 * @...: resulting arguments 3629 */ 3630 int sscanf(const char *buf, const char *fmt, ...) 3631 { 3632 va_list args; 3633 int i; 3634 3635 va_start(args, fmt); 3636 i = vsscanf(buf, fmt, args); 3637 va_end(args); 3638 3639 return i; 3640 } 3641 EXPORT_SYMBOL(sscanf); 3642