1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * linux/lib/vsprintf.c 4 * 5 * Copyright (C) 1991, 1992 Linus Torvalds 6 */ 7 8 /* vsprintf.c -- Lars Wirzenius & Linus Torvalds. */ 9 /* 10 * Wirzenius wrote this portably, Torvalds fucked it up :-) 11 */ 12 13 /* 14 * Fri Jul 13 2001 Crutcher Dunnavant <crutcher+kernel@datastacks.com> 15 * - changed to provide snprintf and vsnprintf functions 16 * So Feb 1 16:51:32 CET 2004 Juergen Quade <quade@hsnr.de> 17 * - scnprintf and vscnprintf 18 */ 19 20 #include <stdarg.h> 21 #include <linux/build_bug.h> 22 #include <linux/clk.h> 23 #include <linux/clk-provider.h> 24 #include <linux/errname.h> 25 #include <linux/module.h> /* for KSYM_SYMBOL_LEN */ 26 #include <linux/types.h> 27 #include <linux/string.h> 28 #include <linux/ctype.h> 29 #include <linux/kernel.h> 30 #include <linux/kallsyms.h> 31 #include <linux/math64.h> 32 #include <linux/uaccess.h> 33 #include <linux/ioport.h> 34 #include <linux/dcache.h> 35 #include <linux/cred.h> 36 #include <linux/rtc.h> 37 #include <linux/uuid.h> 38 #include <linux/of.h> 39 #include <net/addrconf.h> 40 #include <linux/siphash.h> 41 #include <linux/compiler.h> 42 #include <linux/property.h> 43 #ifdef CONFIG_BLOCK 44 #include <linux/blkdev.h> 45 #endif 46 47 #include "../mm/internal.h" /* For the trace_print_flags arrays */ 48 49 #include <asm/page.h> /* for PAGE_SIZE */ 50 #include <asm/byteorder.h> /* cpu_to_le16 */ 51 52 #include <linux/string_helpers.h> 53 #include "kstrtox.h" 54 55 /** 56 * simple_strtoull - convert a string to an unsigned long long 57 * @cp: The start of the string 58 * @endp: A pointer to the end of the parsed string will be placed here 59 * @base: The number base to use 60 * 61 * This function is obsolete. Please use kstrtoull instead. 62 */ 63 unsigned long long simple_strtoull(const char *cp, char **endp, unsigned int base) 64 { 65 unsigned long long result; 66 unsigned int rv; 67 68 cp = _parse_integer_fixup_radix(cp, &base); 69 rv = _parse_integer(cp, base, &result); 70 /* FIXME */ 71 cp += (rv & ~KSTRTOX_OVERFLOW); 72 73 if (endp) 74 *endp = (char *)cp; 75 76 return result; 77 } 78 EXPORT_SYMBOL(simple_strtoull); 79 80 /** 81 * simple_strtoul - convert a string to an unsigned long 82 * @cp: The start of the string 83 * @endp: A pointer to the end of the parsed string will be placed here 84 * @base: The number base to use 85 * 86 * This function is obsolete. Please use kstrtoul instead. 87 */ 88 unsigned long simple_strtoul(const char *cp, char **endp, unsigned int base) 89 { 90 return simple_strtoull(cp, endp, base); 91 } 92 EXPORT_SYMBOL(simple_strtoul); 93 94 /** 95 * simple_strtol - convert a string to a signed long 96 * @cp: The start of the string 97 * @endp: A pointer to the end of the parsed string will be placed here 98 * @base: The number base to use 99 * 100 * This function is obsolete. Please use kstrtol instead. 101 */ 102 long simple_strtol(const char *cp, char **endp, unsigned int base) 103 { 104 if (*cp == '-') 105 return -simple_strtoul(cp + 1, endp, base); 106 107 return simple_strtoul(cp, endp, base); 108 } 109 EXPORT_SYMBOL(simple_strtol); 110 111 /** 112 * simple_strtoll - convert a string to a signed long long 113 * @cp: The start of the string 114 * @endp: A pointer to the end of the parsed string will be placed here 115 * @base: The number base to use 116 * 117 * This function is obsolete. Please use kstrtoll instead. 118 */ 119 long long simple_strtoll(const char *cp, char **endp, unsigned int base) 120 { 121 if (*cp == '-') 122 return -simple_strtoull(cp + 1, endp, base); 123 124 return simple_strtoull(cp, endp, base); 125 } 126 EXPORT_SYMBOL(simple_strtoll); 127 128 static noinline_for_stack 129 int skip_atoi(const char **s) 130 { 131 int i = 0; 132 133 do { 134 i = i*10 + *((*s)++) - '0'; 135 } while (isdigit(**s)); 136 137 return i; 138 } 139 140 /* 141 * Decimal conversion is by far the most typical, and is used for 142 * /proc and /sys data. This directly impacts e.g. top performance 143 * with many processes running. We optimize it for speed by emitting 144 * two characters at a time, using a 200 byte lookup table. This 145 * roughly halves the number of multiplications compared to computing 146 * the digits one at a time. Implementation strongly inspired by the 147 * previous version, which in turn used ideas described at 148 * <http://www.cs.uiowa.edu/~jones/bcd/divide.html> (with permission 149 * from the author, Douglas W. Jones). 150 * 151 * It turns out there is precisely one 26 bit fixed-point 152 * approximation a of 64/100 for which x/100 == (x * (u64)a) >> 32 153 * holds for all x in [0, 10^8-1], namely a = 0x28f5c29. The actual 154 * range happens to be somewhat larger (x <= 1073741898), but that's 155 * irrelevant for our purpose. 156 * 157 * For dividing a number in the range [10^4, 10^6-1] by 100, we still 158 * need a 32x32->64 bit multiply, so we simply use the same constant. 159 * 160 * For dividing a number in the range [100, 10^4-1] by 100, there are 161 * several options. The simplest is (x * 0x147b) >> 19, which is valid 162 * for all x <= 43698. 163 */ 164 165 static const u16 decpair[100] = { 166 #define _(x) (__force u16) cpu_to_le16(((x % 10) | ((x / 10) << 8)) + 0x3030) 167 _( 0), _( 1), _( 2), _( 3), _( 4), _( 5), _( 6), _( 7), _( 8), _( 9), 168 _(10), _(11), _(12), _(13), _(14), _(15), _(16), _(17), _(18), _(19), 169 _(20), _(21), _(22), _(23), _(24), _(25), _(26), _(27), _(28), _(29), 170 _(30), _(31), _(32), _(33), _(34), _(35), _(36), _(37), _(38), _(39), 171 _(40), _(41), _(42), _(43), _(44), _(45), _(46), _(47), _(48), _(49), 172 _(50), _(51), _(52), _(53), _(54), _(55), _(56), _(57), _(58), _(59), 173 _(60), _(61), _(62), _(63), _(64), _(65), _(66), _(67), _(68), _(69), 174 _(70), _(71), _(72), _(73), _(74), _(75), _(76), _(77), _(78), _(79), 175 _(80), _(81), _(82), _(83), _(84), _(85), _(86), _(87), _(88), _(89), 176 _(90), _(91), _(92), _(93), _(94), _(95), _(96), _(97), _(98), _(99), 177 #undef _ 178 }; 179 180 /* 181 * This will print a single '0' even if r == 0, since we would 182 * immediately jump to out_r where two 0s would be written but only 183 * one of them accounted for in buf. This is needed by ip4_string 184 * below. All other callers pass a non-zero value of r. 185 */ 186 static noinline_for_stack 187 char *put_dec_trunc8(char *buf, unsigned r) 188 { 189 unsigned q; 190 191 /* 1 <= r < 10^8 */ 192 if (r < 100) 193 goto out_r; 194 195 /* 100 <= r < 10^8 */ 196 q = (r * (u64)0x28f5c29) >> 32; 197 *((u16 *)buf) = decpair[r - 100*q]; 198 buf += 2; 199 200 /* 1 <= q < 10^6 */ 201 if (q < 100) 202 goto out_q; 203 204 /* 100 <= q < 10^6 */ 205 r = (q * (u64)0x28f5c29) >> 32; 206 *((u16 *)buf) = decpair[q - 100*r]; 207 buf += 2; 208 209 /* 1 <= r < 10^4 */ 210 if (r < 100) 211 goto out_r; 212 213 /* 100 <= r < 10^4 */ 214 q = (r * 0x147b) >> 19; 215 *((u16 *)buf) = decpair[r - 100*q]; 216 buf += 2; 217 out_q: 218 /* 1 <= q < 100 */ 219 r = q; 220 out_r: 221 /* 1 <= r < 100 */ 222 *((u16 *)buf) = decpair[r]; 223 buf += r < 10 ? 1 : 2; 224 return buf; 225 } 226 227 #if BITS_PER_LONG == 64 && BITS_PER_LONG_LONG == 64 228 static noinline_for_stack 229 char *put_dec_full8(char *buf, unsigned r) 230 { 231 unsigned q; 232 233 /* 0 <= r < 10^8 */ 234 q = (r * (u64)0x28f5c29) >> 32; 235 *((u16 *)buf) = decpair[r - 100*q]; 236 buf += 2; 237 238 /* 0 <= q < 10^6 */ 239 r = (q * (u64)0x28f5c29) >> 32; 240 *((u16 *)buf) = decpair[q - 100*r]; 241 buf += 2; 242 243 /* 0 <= r < 10^4 */ 244 q = (r * 0x147b) >> 19; 245 *((u16 *)buf) = decpair[r - 100*q]; 246 buf += 2; 247 248 /* 0 <= q < 100 */ 249 *((u16 *)buf) = decpair[q]; 250 buf += 2; 251 return buf; 252 } 253 254 static noinline_for_stack 255 char *put_dec(char *buf, unsigned long long n) 256 { 257 if (n >= 100*1000*1000) 258 buf = put_dec_full8(buf, do_div(n, 100*1000*1000)); 259 /* 1 <= n <= 1.6e11 */ 260 if (n >= 100*1000*1000) 261 buf = put_dec_full8(buf, do_div(n, 100*1000*1000)); 262 /* 1 <= n < 1e8 */ 263 return put_dec_trunc8(buf, n); 264 } 265 266 #elif BITS_PER_LONG == 32 && BITS_PER_LONG_LONG == 64 267 268 static void 269 put_dec_full4(char *buf, unsigned r) 270 { 271 unsigned q; 272 273 /* 0 <= r < 10^4 */ 274 q = (r * 0x147b) >> 19; 275 *((u16 *)buf) = decpair[r - 100*q]; 276 buf += 2; 277 /* 0 <= q < 100 */ 278 *((u16 *)buf) = decpair[q]; 279 } 280 281 /* 282 * Call put_dec_full4 on x % 10000, return x / 10000. 283 * The approximation x/10000 == (x * 0x346DC5D7) >> 43 284 * holds for all x < 1,128,869,999. The largest value this 285 * helper will ever be asked to convert is 1,125,520,955. 286 * (second call in the put_dec code, assuming n is all-ones). 287 */ 288 static noinline_for_stack 289 unsigned put_dec_helper4(char *buf, unsigned x) 290 { 291 uint32_t q = (x * (uint64_t)0x346DC5D7) >> 43; 292 293 put_dec_full4(buf, x - q * 10000); 294 return q; 295 } 296 297 /* Based on code by Douglas W. Jones found at 298 * <http://www.cs.uiowa.edu/~jones/bcd/decimal.html#sixtyfour> 299 * (with permission from the author). 300 * Performs no 64-bit division and hence should be fast on 32-bit machines. 301 */ 302 static 303 char *put_dec(char *buf, unsigned long long n) 304 { 305 uint32_t d3, d2, d1, q, h; 306 307 if (n < 100*1000*1000) 308 return put_dec_trunc8(buf, n); 309 310 d1 = ((uint32_t)n >> 16); /* implicit "& 0xffff" */ 311 h = (n >> 32); 312 d2 = (h ) & 0xffff; 313 d3 = (h >> 16); /* implicit "& 0xffff" */ 314 315 /* n = 2^48 d3 + 2^32 d2 + 2^16 d1 + d0 316 = 281_4749_7671_0656 d3 + 42_9496_7296 d2 + 6_5536 d1 + d0 */ 317 q = 656 * d3 + 7296 * d2 + 5536 * d1 + ((uint32_t)n & 0xffff); 318 q = put_dec_helper4(buf, q); 319 320 q += 7671 * d3 + 9496 * d2 + 6 * d1; 321 q = put_dec_helper4(buf+4, q); 322 323 q += 4749 * d3 + 42 * d2; 324 q = put_dec_helper4(buf+8, q); 325 326 q += 281 * d3; 327 buf += 12; 328 if (q) 329 buf = put_dec_trunc8(buf, q); 330 else while (buf[-1] == '0') 331 --buf; 332 333 return buf; 334 } 335 336 #endif 337 338 /* 339 * Convert passed number to decimal string. 340 * Returns the length of string. On buffer overflow, returns 0. 341 * 342 * If speed is not important, use snprintf(). It's easy to read the code. 343 */ 344 int num_to_str(char *buf, int size, unsigned long long num, unsigned int width) 345 { 346 /* put_dec requires 2-byte alignment of the buffer. */ 347 char tmp[sizeof(num) * 3] __aligned(2); 348 int idx, len; 349 350 /* put_dec() may work incorrectly for num = 0 (generate "", not "0") */ 351 if (num <= 9) { 352 tmp[0] = '0' + num; 353 len = 1; 354 } else { 355 len = put_dec(tmp, num) - tmp; 356 } 357 358 if (len > size || width > size) 359 return 0; 360 361 if (width > len) { 362 width = width - len; 363 for (idx = 0; idx < width; idx++) 364 buf[idx] = ' '; 365 } else { 366 width = 0; 367 } 368 369 for (idx = 0; idx < len; ++idx) 370 buf[idx + width] = tmp[len - idx - 1]; 371 372 return len + width; 373 } 374 375 #define SIGN 1 /* unsigned/signed, must be 1 */ 376 #define LEFT 2 /* left justified */ 377 #define PLUS 4 /* show plus */ 378 #define SPACE 8 /* space if plus */ 379 #define ZEROPAD 16 /* pad with zero, must be 16 == '0' - ' ' */ 380 #define SMALL 32 /* use lowercase in hex (must be 32 == 0x20) */ 381 #define SPECIAL 64 /* prefix hex with "0x", octal with "0" */ 382 383 enum format_type { 384 FORMAT_TYPE_NONE, /* Just a string part */ 385 FORMAT_TYPE_WIDTH, 386 FORMAT_TYPE_PRECISION, 387 FORMAT_TYPE_CHAR, 388 FORMAT_TYPE_STR, 389 FORMAT_TYPE_PTR, 390 FORMAT_TYPE_PERCENT_CHAR, 391 FORMAT_TYPE_INVALID, 392 FORMAT_TYPE_LONG_LONG, 393 FORMAT_TYPE_ULONG, 394 FORMAT_TYPE_LONG, 395 FORMAT_TYPE_UBYTE, 396 FORMAT_TYPE_BYTE, 397 FORMAT_TYPE_USHORT, 398 FORMAT_TYPE_SHORT, 399 FORMAT_TYPE_UINT, 400 FORMAT_TYPE_INT, 401 FORMAT_TYPE_SIZE_T, 402 FORMAT_TYPE_PTRDIFF 403 }; 404 405 struct printf_spec { 406 unsigned int type:8; /* format_type enum */ 407 signed int field_width:24; /* width of output field */ 408 unsigned int flags:8; /* flags to number() */ 409 unsigned int base:8; /* number base, 8, 10 or 16 only */ 410 signed int precision:16; /* # of digits/chars */ 411 } __packed; 412 static_assert(sizeof(struct printf_spec) == 8); 413 414 #define FIELD_WIDTH_MAX ((1 << 23) - 1) 415 #define PRECISION_MAX ((1 << 15) - 1) 416 417 static noinline_for_stack 418 char *number(char *buf, char *end, unsigned long long num, 419 struct printf_spec spec) 420 { 421 /* put_dec requires 2-byte alignment of the buffer. */ 422 char tmp[3 * sizeof(num)] __aligned(2); 423 char sign; 424 char locase; 425 int need_pfx = ((spec.flags & SPECIAL) && spec.base != 10); 426 int i; 427 bool is_zero = num == 0LL; 428 int field_width = spec.field_width; 429 int precision = spec.precision; 430 431 /* locase = 0 or 0x20. ORing digits or letters with 'locase' 432 * produces same digits or (maybe lowercased) letters */ 433 locase = (spec.flags & SMALL); 434 if (spec.flags & LEFT) 435 spec.flags &= ~ZEROPAD; 436 sign = 0; 437 if (spec.flags & SIGN) { 438 if ((signed long long)num < 0) { 439 sign = '-'; 440 num = -(signed long long)num; 441 field_width--; 442 } else if (spec.flags & PLUS) { 443 sign = '+'; 444 field_width--; 445 } else if (spec.flags & SPACE) { 446 sign = ' '; 447 field_width--; 448 } 449 } 450 if (need_pfx) { 451 if (spec.base == 16) 452 field_width -= 2; 453 else if (!is_zero) 454 field_width--; 455 } 456 457 /* generate full string in tmp[], in reverse order */ 458 i = 0; 459 if (num < spec.base) 460 tmp[i++] = hex_asc_upper[num] | locase; 461 else if (spec.base != 10) { /* 8 or 16 */ 462 int mask = spec.base - 1; 463 int shift = 3; 464 465 if (spec.base == 16) 466 shift = 4; 467 do { 468 tmp[i++] = (hex_asc_upper[((unsigned char)num) & mask] | locase); 469 num >>= shift; 470 } while (num); 471 } else { /* base 10 */ 472 i = put_dec(tmp, num) - tmp; 473 } 474 475 /* printing 100 using %2d gives "100", not "00" */ 476 if (i > precision) 477 precision = i; 478 /* leading space padding */ 479 field_width -= precision; 480 if (!(spec.flags & (ZEROPAD | LEFT))) { 481 while (--field_width >= 0) { 482 if (buf < end) 483 *buf = ' '; 484 ++buf; 485 } 486 } 487 /* sign */ 488 if (sign) { 489 if (buf < end) 490 *buf = sign; 491 ++buf; 492 } 493 /* "0x" / "0" prefix */ 494 if (need_pfx) { 495 if (spec.base == 16 || !is_zero) { 496 if (buf < end) 497 *buf = '0'; 498 ++buf; 499 } 500 if (spec.base == 16) { 501 if (buf < end) 502 *buf = ('X' | locase); 503 ++buf; 504 } 505 } 506 /* zero or space padding */ 507 if (!(spec.flags & LEFT)) { 508 char c = ' ' + (spec.flags & ZEROPAD); 509 BUILD_BUG_ON(' ' + ZEROPAD != '0'); 510 while (--field_width >= 0) { 511 if (buf < end) 512 *buf = c; 513 ++buf; 514 } 515 } 516 /* hmm even more zero padding? */ 517 while (i <= --precision) { 518 if (buf < end) 519 *buf = '0'; 520 ++buf; 521 } 522 /* actual digits of result */ 523 while (--i >= 0) { 524 if (buf < end) 525 *buf = tmp[i]; 526 ++buf; 527 } 528 /* trailing space padding */ 529 while (--field_width >= 0) { 530 if (buf < end) 531 *buf = ' '; 532 ++buf; 533 } 534 535 return buf; 536 } 537 538 static noinline_for_stack 539 char *special_hex_number(char *buf, char *end, unsigned long long num, int size) 540 { 541 struct printf_spec spec; 542 543 spec.type = FORMAT_TYPE_PTR; 544 spec.field_width = 2 + 2 * size; /* 0x + hex */ 545 spec.flags = SPECIAL | SMALL | ZEROPAD; 546 spec.base = 16; 547 spec.precision = -1; 548 549 return number(buf, end, num, spec); 550 } 551 552 static void move_right(char *buf, char *end, unsigned len, unsigned spaces) 553 { 554 size_t size; 555 if (buf >= end) /* nowhere to put anything */ 556 return; 557 size = end - buf; 558 if (size <= spaces) { 559 memset(buf, ' ', size); 560 return; 561 } 562 if (len) { 563 if (len > size - spaces) 564 len = size - spaces; 565 memmove(buf + spaces, buf, len); 566 } 567 memset(buf, ' ', spaces); 568 } 569 570 /* 571 * Handle field width padding for a string. 572 * @buf: current buffer position 573 * @n: length of string 574 * @end: end of output buffer 575 * @spec: for field width and flags 576 * Returns: new buffer position after padding. 577 */ 578 static noinline_for_stack 579 char *widen_string(char *buf, int n, char *end, struct printf_spec spec) 580 { 581 unsigned spaces; 582 583 if (likely(n >= spec.field_width)) 584 return buf; 585 /* we want to pad the sucker */ 586 spaces = spec.field_width - n; 587 if (!(spec.flags & LEFT)) { 588 move_right(buf - n, end, n, spaces); 589 return buf + spaces; 590 } 591 while (spaces--) { 592 if (buf < end) 593 *buf = ' '; 594 ++buf; 595 } 596 return buf; 597 } 598 599 /* Handle string from a well known address. */ 600 static char *string_nocheck(char *buf, char *end, const char *s, 601 struct printf_spec spec) 602 { 603 int len = 0; 604 int lim = spec.precision; 605 606 while (lim--) { 607 char c = *s++; 608 if (!c) 609 break; 610 if (buf < end) 611 *buf = c; 612 ++buf; 613 ++len; 614 } 615 return widen_string(buf, len, end, spec); 616 } 617 618 static char *err_ptr(char *buf, char *end, void *ptr, 619 struct printf_spec spec) 620 { 621 int err = PTR_ERR(ptr); 622 const char *sym = errname(err); 623 624 if (sym) 625 return string_nocheck(buf, end, sym, spec); 626 627 /* 628 * Somebody passed ERR_PTR(-1234) or some other non-existing 629 * Efoo - or perhaps CONFIG_SYMBOLIC_ERRNAME=n. Fall back to 630 * printing it as its decimal representation. 631 */ 632 spec.flags |= SIGN; 633 spec.base = 10; 634 return number(buf, end, err, spec); 635 } 636 637 /* Be careful: error messages must fit into the given buffer. */ 638 static char *error_string(char *buf, char *end, const char *s, 639 struct printf_spec spec) 640 { 641 /* 642 * Hard limit to avoid a completely insane messages. It actually 643 * works pretty well because most error messages are in 644 * the many pointer format modifiers. 645 */ 646 if (spec.precision == -1) 647 spec.precision = 2 * sizeof(void *); 648 649 return string_nocheck(buf, end, s, spec); 650 } 651 652 /* 653 * Do not call any complex external code here. Nested printk()/vsprintf() 654 * might cause infinite loops. Failures might break printk() and would 655 * be hard to debug. 656 */ 657 static const char *check_pointer_msg(const void *ptr) 658 { 659 if (!ptr) 660 return "(null)"; 661 662 if ((unsigned long)ptr < PAGE_SIZE || IS_ERR_VALUE(ptr)) 663 return "(efault)"; 664 665 return NULL; 666 } 667 668 static int check_pointer(char **buf, char *end, const void *ptr, 669 struct printf_spec spec) 670 { 671 const char *err_msg; 672 673 err_msg = check_pointer_msg(ptr); 674 if (err_msg) { 675 *buf = error_string(*buf, end, err_msg, spec); 676 return -EFAULT; 677 } 678 679 return 0; 680 } 681 682 static noinline_for_stack 683 char *string(char *buf, char *end, const char *s, 684 struct printf_spec spec) 685 { 686 if (check_pointer(&buf, end, s, spec)) 687 return buf; 688 689 return string_nocheck(buf, end, s, spec); 690 } 691 692 static char *pointer_string(char *buf, char *end, 693 const void *ptr, 694 struct printf_spec spec) 695 { 696 spec.base = 16; 697 spec.flags |= SMALL; 698 if (spec.field_width == -1) { 699 spec.field_width = 2 * sizeof(ptr); 700 spec.flags |= ZEROPAD; 701 } 702 703 return number(buf, end, (unsigned long int)ptr, spec); 704 } 705 706 /* Make pointers available for printing early in the boot sequence. */ 707 static int debug_boot_weak_hash __ro_after_init; 708 709 static int __init debug_boot_weak_hash_enable(char *str) 710 { 711 debug_boot_weak_hash = 1; 712 pr_info("debug_boot_weak_hash enabled\n"); 713 return 0; 714 } 715 early_param("debug_boot_weak_hash", debug_boot_weak_hash_enable); 716 717 static DEFINE_STATIC_KEY_TRUE(not_filled_random_ptr_key); 718 static siphash_key_t ptr_key __read_mostly; 719 720 static void enable_ptr_key_workfn(struct work_struct *work) 721 { 722 get_random_bytes(&ptr_key, sizeof(ptr_key)); 723 /* Needs to run from preemptible context */ 724 static_branch_disable(¬_filled_random_ptr_key); 725 } 726 727 static DECLARE_WORK(enable_ptr_key_work, enable_ptr_key_workfn); 728 729 static void fill_random_ptr_key(struct random_ready_callback *unused) 730 { 731 /* This may be in an interrupt handler. */ 732 queue_work(system_unbound_wq, &enable_ptr_key_work); 733 } 734 735 static struct random_ready_callback random_ready = { 736 .func = fill_random_ptr_key 737 }; 738 739 static int __init initialize_ptr_random(void) 740 { 741 int key_size = sizeof(ptr_key); 742 int ret; 743 744 /* Use hw RNG if available. */ 745 if (get_random_bytes_arch(&ptr_key, key_size) == key_size) { 746 static_branch_disable(¬_filled_random_ptr_key); 747 return 0; 748 } 749 750 ret = add_random_ready_callback(&random_ready); 751 if (!ret) { 752 return 0; 753 } else if (ret == -EALREADY) { 754 /* This is in preemptible context */ 755 enable_ptr_key_workfn(&enable_ptr_key_work); 756 return 0; 757 } 758 759 return ret; 760 } 761 early_initcall(initialize_ptr_random); 762 763 /* Maps a pointer to a 32 bit unique identifier. */ 764 static inline int __ptr_to_hashval(const void *ptr, unsigned long *hashval_out) 765 { 766 unsigned long hashval; 767 768 if (static_branch_unlikely(¬_filled_random_ptr_key)) 769 return -EAGAIN; 770 771 #ifdef CONFIG_64BIT 772 hashval = (unsigned long)siphash_1u64((u64)ptr, &ptr_key); 773 /* 774 * Mask off the first 32 bits, this makes explicit that we have 775 * modified the address (and 32 bits is plenty for a unique ID). 776 */ 777 hashval = hashval & 0xffffffff; 778 #else 779 hashval = (unsigned long)siphash_1u32((u32)ptr, &ptr_key); 780 #endif 781 *hashval_out = hashval; 782 return 0; 783 } 784 785 int ptr_to_hashval(const void *ptr, unsigned long *hashval_out) 786 { 787 return __ptr_to_hashval(ptr, hashval_out); 788 } 789 790 static char *ptr_to_id(char *buf, char *end, const void *ptr, 791 struct printf_spec spec) 792 { 793 const char *str = sizeof(ptr) == 8 ? "(____ptrval____)" : "(ptrval)"; 794 unsigned long hashval; 795 int ret; 796 797 /* When debugging early boot use non-cryptographically secure hash. */ 798 if (unlikely(debug_boot_weak_hash)) { 799 hashval = hash_long((unsigned long)ptr, 32); 800 return pointer_string(buf, end, (const void *)hashval, spec); 801 } 802 803 ret = __ptr_to_hashval(ptr, &hashval); 804 if (ret) { 805 spec.field_width = 2 * sizeof(ptr); 806 /* string length must be less than default_width */ 807 return error_string(buf, end, str, spec); 808 } 809 810 return pointer_string(buf, end, (const void *)hashval, spec); 811 } 812 813 int kptr_restrict __read_mostly; 814 815 static noinline_for_stack 816 char *restricted_pointer(char *buf, char *end, const void *ptr, 817 struct printf_spec spec) 818 { 819 switch (kptr_restrict) { 820 case 0: 821 /* Handle as %p, hash and do _not_ leak addresses. */ 822 return ptr_to_id(buf, end, ptr, spec); 823 case 1: { 824 const struct cred *cred; 825 826 /* 827 * kptr_restrict==1 cannot be used in IRQ context 828 * because its test for CAP_SYSLOG would be meaningless. 829 */ 830 if (in_irq() || in_serving_softirq() || in_nmi()) { 831 if (spec.field_width == -1) 832 spec.field_width = 2 * sizeof(ptr); 833 return error_string(buf, end, "pK-error", spec); 834 } 835 836 /* 837 * Only print the real pointer value if the current 838 * process has CAP_SYSLOG and is running with the 839 * same credentials it started with. This is because 840 * access to files is checked at open() time, but %pK 841 * checks permission at read() time. We don't want to 842 * leak pointer values if a binary opens a file using 843 * %pK and then elevates privileges before reading it. 844 */ 845 cred = current_cred(); 846 if (!has_capability_noaudit(current, CAP_SYSLOG) || 847 !uid_eq(cred->euid, cred->uid) || 848 !gid_eq(cred->egid, cred->gid)) 849 ptr = NULL; 850 break; 851 } 852 case 2: 853 default: 854 /* Always print 0's for %pK */ 855 ptr = NULL; 856 break; 857 } 858 859 return pointer_string(buf, end, ptr, spec); 860 } 861 862 static noinline_for_stack 863 char *dentry_name(char *buf, char *end, const struct dentry *d, struct printf_spec spec, 864 const char *fmt) 865 { 866 const char *array[4], *s; 867 const struct dentry *p; 868 int depth; 869 int i, n; 870 871 switch (fmt[1]) { 872 case '2': case '3': case '4': 873 depth = fmt[1] - '0'; 874 break; 875 default: 876 depth = 1; 877 } 878 879 rcu_read_lock(); 880 for (i = 0; i < depth; i++, d = p) { 881 if (check_pointer(&buf, end, d, spec)) { 882 rcu_read_unlock(); 883 return buf; 884 } 885 886 p = READ_ONCE(d->d_parent); 887 array[i] = READ_ONCE(d->d_name.name); 888 if (p == d) { 889 if (i) 890 array[i] = ""; 891 i++; 892 break; 893 } 894 } 895 s = array[--i]; 896 for (n = 0; n != spec.precision; n++, buf++) { 897 char c = *s++; 898 if (!c) { 899 if (!i) 900 break; 901 c = '/'; 902 s = array[--i]; 903 } 904 if (buf < end) 905 *buf = c; 906 } 907 rcu_read_unlock(); 908 return widen_string(buf, n, end, spec); 909 } 910 911 static noinline_for_stack 912 char *file_dentry_name(char *buf, char *end, const struct file *f, 913 struct printf_spec spec, const char *fmt) 914 { 915 if (check_pointer(&buf, end, f, spec)) 916 return buf; 917 918 return dentry_name(buf, end, f->f_path.dentry, spec, fmt); 919 } 920 #ifdef CONFIG_BLOCK 921 static noinline_for_stack 922 char *bdev_name(char *buf, char *end, struct block_device *bdev, 923 struct printf_spec spec, const char *fmt) 924 { 925 struct gendisk *hd; 926 927 if (check_pointer(&buf, end, bdev, spec)) 928 return buf; 929 930 hd = bdev->bd_disk; 931 buf = string(buf, end, hd->disk_name, spec); 932 if (bdev->bd_part->partno) { 933 if (isdigit(hd->disk_name[strlen(hd->disk_name)-1])) { 934 if (buf < end) 935 *buf = 'p'; 936 buf++; 937 } 938 buf = number(buf, end, bdev->bd_part->partno, spec); 939 } 940 return buf; 941 } 942 #endif 943 944 static noinline_for_stack 945 char *symbol_string(char *buf, char *end, void *ptr, 946 struct printf_spec spec, const char *fmt) 947 { 948 unsigned long value; 949 #ifdef CONFIG_KALLSYMS 950 char sym[KSYM_SYMBOL_LEN]; 951 #endif 952 953 if (fmt[1] == 'R') 954 ptr = __builtin_extract_return_addr(ptr); 955 value = (unsigned long)ptr; 956 957 #ifdef CONFIG_KALLSYMS 958 if (*fmt == 'B') 959 sprint_backtrace(sym, value); 960 else if (*fmt != 's') 961 sprint_symbol(sym, value); 962 else 963 sprint_symbol_no_offset(sym, value); 964 965 return string_nocheck(buf, end, sym, spec); 966 #else 967 return special_hex_number(buf, end, value, sizeof(void *)); 968 #endif 969 } 970 971 static const struct printf_spec default_str_spec = { 972 .field_width = -1, 973 .precision = -1, 974 }; 975 976 static const struct printf_spec default_flag_spec = { 977 .base = 16, 978 .precision = -1, 979 .flags = SPECIAL | SMALL, 980 }; 981 982 static const struct printf_spec default_dec_spec = { 983 .base = 10, 984 .precision = -1, 985 }; 986 987 static const struct printf_spec default_dec02_spec = { 988 .base = 10, 989 .field_width = 2, 990 .precision = -1, 991 .flags = ZEROPAD, 992 }; 993 994 static const struct printf_spec default_dec04_spec = { 995 .base = 10, 996 .field_width = 4, 997 .precision = -1, 998 .flags = ZEROPAD, 999 }; 1000 1001 static noinline_for_stack 1002 char *resource_string(char *buf, char *end, struct resource *res, 1003 struct printf_spec spec, const char *fmt) 1004 { 1005 #ifndef IO_RSRC_PRINTK_SIZE 1006 #define IO_RSRC_PRINTK_SIZE 6 1007 #endif 1008 1009 #ifndef MEM_RSRC_PRINTK_SIZE 1010 #define MEM_RSRC_PRINTK_SIZE 10 1011 #endif 1012 static const struct printf_spec io_spec = { 1013 .base = 16, 1014 .field_width = IO_RSRC_PRINTK_SIZE, 1015 .precision = -1, 1016 .flags = SPECIAL | SMALL | ZEROPAD, 1017 }; 1018 static const struct printf_spec mem_spec = { 1019 .base = 16, 1020 .field_width = MEM_RSRC_PRINTK_SIZE, 1021 .precision = -1, 1022 .flags = SPECIAL | SMALL | ZEROPAD, 1023 }; 1024 static const struct printf_spec bus_spec = { 1025 .base = 16, 1026 .field_width = 2, 1027 .precision = -1, 1028 .flags = SMALL | ZEROPAD, 1029 }; 1030 static const struct printf_spec str_spec = { 1031 .field_width = -1, 1032 .precision = 10, 1033 .flags = LEFT, 1034 }; 1035 1036 /* 32-bit res (sizeof==4): 10 chars in dec, 10 in hex ("0x" + 8) 1037 * 64-bit res (sizeof==8): 20 chars in dec, 18 in hex ("0x" + 16) */ 1038 #define RSRC_BUF_SIZE ((2 * sizeof(resource_size_t)) + 4) 1039 #define FLAG_BUF_SIZE (2 * sizeof(res->flags)) 1040 #define DECODED_BUF_SIZE sizeof("[mem - 64bit pref window disabled]") 1041 #define RAW_BUF_SIZE sizeof("[mem - flags 0x]") 1042 char sym[max(2*RSRC_BUF_SIZE + DECODED_BUF_SIZE, 1043 2*RSRC_BUF_SIZE + FLAG_BUF_SIZE + RAW_BUF_SIZE)]; 1044 1045 char *p = sym, *pend = sym + sizeof(sym); 1046 int decode = (fmt[0] == 'R') ? 1 : 0; 1047 const struct printf_spec *specp; 1048 1049 if (check_pointer(&buf, end, res, spec)) 1050 return buf; 1051 1052 *p++ = '['; 1053 if (res->flags & IORESOURCE_IO) { 1054 p = string_nocheck(p, pend, "io ", str_spec); 1055 specp = &io_spec; 1056 } else if (res->flags & IORESOURCE_MEM) { 1057 p = string_nocheck(p, pend, "mem ", str_spec); 1058 specp = &mem_spec; 1059 } else if (res->flags & IORESOURCE_IRQ) { 1060 p = string_nocheck(p, pend, "irq ", str_spec); 1061 specp = &default_dec_spec; 1062 } else if (res->flags & IORESOURCE_DMA) { 1063 p = string_nocheck(p, pend, "dma ", str_spec); 1064 specp = &default_dec_spec; 1065 } else if (res->flags & IORESOURCE_BUS) { 1066 p = string_nocheck(p, pend, "bus ", str_spec); 1067 specp = &bus_spec; 1068 } else { 1069 p = string_nocheck(p, pend, "??? ", str_spec); 1070 specp = &mem_spec; 1071 decode = 0; 1072 } 1073 if (decode && res->flags & IORESOURCE_UNSET) { 1074 p = string_nocheck(p, pend, "size ", str_spec); 1075 p = number(p, pend, resource_size(res), *specp); 1076 } else { 1077 p = number(p, pend, res->start, *specp); 1078 if (res->start != res->end) { 1079 *p++ = '-'; 1080 p = number(p, pend, res->end, *specp); 1081 } 1082 } 1083 if (decode) { 1084 if (res->flags & IORESOURCE_MEM_64) 1085 p = string_nocheck(p, pend, " 64bit", str_spec); 1086 if (res->flags & IORESOURCE_PREFETCH) 1087 p = string_nocheck(p, pend, " pref", str_spec); 1088 if (res->flags & IORESOURCE_WINDOW) 1089 p = string_nocheck(p, pend, " window", str_spec); 1090 if (res->flags & IORESOURCE_DISABLED) 1091 p = string_nocheck(p, pend, " disabled", str_spec); 1092 } else { 1093 p = string_nocheck(p, pend, " flags ", str_spec); 1094 p = number(p, pend, res->flags, default_flag_spec); 1095 } 1096 *p++ = ']'; 1097 *p = '\0'; 1098 1099 return string_nocheck(buf, end, sym, spec); 1100 } 1101 1102 static noinline_for_stack 1103 char *hex_string(char *buf, char *end, u8 *addr, struct printf_spec spec, 1104 const char *fmt) 1105 { 1106 int i, len = 1; /* if we pass '%ph[CDN]', field width remains 1107 negative value, fallback to the default */ 1108 char separator; 1109 1110 if (spec.field_width == 0) 1111 /* nothing to print */ 1112 return buf; 1113 1114 if (check_pointer(&buf, end, addr, spec)) 1115 return buf; 1116 1117 switch (fmt[1]) { 1118 case 'C': 1119 separator = ':'; 1120 break; 1121 case 'D': 1122 separator = '-'; 1123 break; 1124 case 'N': 1125 separator = 0; 1126 break; 1127 default: 1128 separator = ' '; 1129 break; 1130 } 1131 1132 if (spec.field_width > 0) 1133 len = min_t(int, spec.field_width, 64); 1134 1135 for (i = 0; i < len; ++i) { 1136 if (buf < end) 1137 *buf = hex_asc_hi(addr[i]); 1138 ++buf; 1139 if (buf < end) 1140 *buf = hex_asc_lo(addr[i]); 1141 ++buf; 1142 1143 if (separator && i != len - 1) { 1144 if (buf < end) 1145 *buf = separator; 1146 ++buf; 1147 } 1148 } 1149 1150 return buf; 1151 } 1152 1153 static noinline_for_stack 1154 char *bitmap_string(char *buf, char *end, unsigned long *bitmap, 1155 struct printf_spec spec, const char *fmt) 1156 { 1157 const int CHUNKSZ = 32; 1158 int nr_bits = max_t(int, spec.field_width, 0); 1159 int i, chunksz; 1160 bool first = true; 1161 1162 if (check_pointer(&buf, end, bitmap, spec)) 1163 return buf; 1164 1165 /* reused to print numbers */ 1166 spec = (struct printf_spec){ .flags = SMALL | ZEROPAD, .base = 16 }; 1167 1168 chunksz = nr_bits & (CHUNKSZ - 1); 1169 if (chunksz == 0) 1170 chunksz = CHUNKSZ; 1171 1172 i = ALIGN(nr_bits, CHUNKSZ) - CHUNKSZ; 1173 for (; i >= 0; i -= CHUNKSZ) { 1174 u32 chunkmask, val; 1175 int word, bit; 1176 1177 chunkmask = ((1ULL << chunksz) - 1); 1178 word = i / BITS_PER_LONG; 1179 bit = i % BITS_PER_LONG; 1180 val = (bitmap[word] >> bit) & chunkmask; 1181 1182 if (!first) { 1183 if (buf < end) 1184 *buf = ','; 1185 buf++; 1186 } 1187 first = false; 1188 1189 spec.field_width = DIV_ROUND_UP(chunksz, 4); 1190 buf = number(buf, end, val, spec); 1191 1192 chunksz = CHUNKSZ; 1193 } 1194 return buf; 1195 } 1196 1197 static noinline_for_stack 1198 char *bitmap_list_string(char *buf, char *end, unsigned long *bitmap, 1199 struct printf_spec spec, const char *fmt) 1200 { 1201 int nr_bits = max_t(int, spec.field_width, 0); 1202 /* current bit is 'cur', most recently seen range is [rbot, rtop] */ 1203 int cur, rbot, rtop; 1204 bool first = true; 1205 1206 if (check_pointer(&buf, end, bitmap, spec)) 1207 return buf; 1208 1209 rbot = cur = find_first_bit(bitmap, nr_bits); 1210 while (cur < nr_bits) { 1211 rtop = cur; 1212 cur = find_next_bit(bitmap, nr_bits, cur + 1); 1213 if (cur < nr_bits && cur <= rtop + 1) 1214 continue; 1215 1216 if (!first) { 1217 if (buf < end) 1218 *buf = ','; 1219 buf++; 1220 } 1221 first = false; 1222 1223 buf = number(buf, end, rbot, default_dec_spec); 1224 if (rbot < rtop) { 1225 if (buf < end) 1226 *buf = '-'; 1227 buf++; 1228 1229 buf = number(buf, end, rtop, default_dec_spec); 1230 } 1231 1232 rbot = cur; 1233 } 1234 return buf; 1235 } 1236 1237 static noinline_for_stack 1238 char *mac_address_string(char *buf, char *end, u8 *addr, 1239 struct printf_spec spec, const char *fmt) 1240 { 1241 char mac_addr[sizeof("xx:xx:xx:xx:xx:xx")]; 1242 char *p = mac_addr; 1243 int i; 1244 char separator; 1245 bool reversed = false; 1246 1247 if (check_pointer(&buf, end, addr, spec)) 1248 return buf; 1249 1250 switch (fmt[1]) { 1251 case 'F': 1252 separator = '-'; 1253 break; 1254 1255 case 'R': 1256 reversed = true; 1257 /* fall through */ 1258 1259 default: 1260 separator = ':'; 1261 break; 1262 } 1263 1264 for (i = 0; i < 6; i++) { 1265 if (reversed) 1266 p = hex_byte_pack(p, addr[5 - i]); 1267 else 1268 p = hex_byte_pack(p, addr[i]); 1269 1270 if (fmt[0] == 'M' && i != 5) 1271 *p++ = separator; 1272 } 1273 *p = '\0'; 1274 1275 return string_nocheck(buf, end, mac_addr, spec); 1276 } 1277 1278 static noinline_for_stack 1279 char *ip4_string(char *p, const u8 *addr, const char *fmt) 1280 { 1281 int i; 1282 bool leading_zeros = (fmt[0] == 'i'); 1283 int index; 1284 int step; 1285 1286 switch (fmt[2]) { 1287 case 'h': 1288 #ifdef __BIG_ENDIAN 1289 index = 0; 1290 step = 1; 1291 #else 1292 index = 3; 1293 step = -1; 1294 #endif 1295 break; 1296 case 'l': 1297 index = 3; 1298 step = -1; 1299 break; 1300 case 'n': 1301 case 'b': 1302 default: 1303 index = 0; 1304 step = 1; 1305 break; 1306 } 1307 for (i = 0; i < 4; i++) { 1308 char temp[4] __aligned(2); /* hold each IP quad in reverse order */ 1309 int digits = put_dec_trunc8(temp, addr[index]) - temp; 1310 if (leading_zeros) { 1311 if (digits < 3) 1312 *p++ = '0'; 1313 if (digits < 2) 1314 *p++ = '0'; 1315 } 1316 /* reverse the digits in the quad */ 1317 while (digits--) 1318 *p++ = temp[digits]; 1319 if (i < 3) 1320 *p++ = '.'; 1321 index += step; 1322 } 1323 *p = '\0'; 1324 1325 return p; 1326 } 1327 1328 static noinline_for_stack 1329 char *ip6_compressed_string(char *p, const char *addr) 1330 { 1331 int i, j, range; 1332 unsigned char zerolength[8]; 1333 int longest = 1; 1334 int colonpos = -1; 1335 u16 word; 1336 u8 hi, lo; 1337 bool needcolon = false; 1338 bool useIPv4; 1339 struct in6_addr in6; 1340 1341 memcpy(&in6, addr, sizeof(struct in6_addr)); 1342 1343 useIPv4 = ipv6_addr_v4mapped(&in6) || ipv6_addr_is_isatap(&in6); 1344 1345 memset(zerolength, 0, sizeof(zerolength)); 1346 1347 if (useIPv4) 1348 range = 6; 1349 else 1350 range = 8; 1351 1352 /* find position of longest 0 run */ 1353 for (i = 0; i < range; i++) { 1354 for (j = i; j < range; j++) { 1355 if (in6.s6_addr16[j] != 0) 1356 break; 1357 zerolength[i]++; 1358 } 1359 } 1360 for (i = 0; i < range; i++) { 1361 if (zerolength[i] > longest) { 1362 longest = zerolength[i]; 1363 colonpos = i; 1364 } 1365 } 1366 if (longest == 1) /* don't compress a single 0 */ 1367 colonpos = -1; 1368 1369 /* emit address */ 1370 for (i = 0; i < range; i++) { 1371 if (i == colonpos) { 1372 if (needcolon || i == 0) 1373 *p++ = ':'; 1374 *p++ = ':'; 1375 needcolon = false; 1376 i += longest - 1; 1377 continue; 1378 } 1379 if (needcolon) { 1380 *p++ = ':'; 1381 needcolon = false; 1382 } 1383 /* hex u16 without leading 0s */ 1384 word = ntohs(in6.s6_addr16[i]); 1385 hi = word >> 8; 1386 lo = word & 0xff; 1387 if (hi) { 1388 if (hi > 0x0f) 1389 p = hex_byte_pack(p, hi); 1390 else 1391 *p++ = hex_asc_lo(hi); 1392 p = hex_byte_pack(p, lo); 1393 } 1394 else if (lo > 0x0f) 1395 p = hex_byte_pack(p, lo); 1396 else 1397 *p++ = hex_asc_lo(lo); 1398 needcolon = true; 1399 } 1400 1401 if (useIPv4) { 1402 if (needcolon) 1403 *p++ = ':'; 1404 p = ip4_string(p, &in6.s6_addr[12], "I4"); 1405 } 1406 *p = '\0'; 1407 1408 return p; 1409 } 1410 1411 static noinline_for_stack 1412 char *ip6_string(char *p, const char *addr, const char *fmt) 1413 { 1414 int i; 1415 1416 for (i = 0; i < 8; i++) { 1417 p = hex_byte_pack(p, *addr++); 1418 p = hex_byte_pack(p, *addr++); 1419 if (fmt[0] == 'I' && i != 7) 1420 *p++ = ':'; 1421 } 1422 *p = '\0'; 1423 1424 return p; 1425 } 1426 1427 static noinline_for_stack 1428 char *ip6_addr_string(char *buf, char *end, const u8 *addr, 1429 struct printf_spec spec, const char *fmt) 1430 { 1431 char ip6_addr[sizeof("xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255")]; 1432 1433 if (fmt[0] == 'I' && fmt[2] == 'c') 1434 ip6_compressed_string(ip6_addr, addr); 1435 else 1436 ip6_string(ip6_addr, addr, fmt); 1437 1438 return string_nocheck(buf, end, ip6_addr, spec); 1439 } 1440 1441 static noinline_for_stack 1442 char *ip4_addr_string(char *buf, char *end, const u8 *addr, 1443 struct printf_spec spec, const char *fmt) 1444 { 1445 char ip4_addr[sizeof("255.255.255.255")]; 1446 1447 ip4_string(ip4_addr, addr, fmt); 1448 1449 return string_nocheck(buf, end, ip4_addr, spec); 1450 } 1451 1452 static noinline_for_stack 1453 char *ip6_addr_string_sa(char *buf, char *end, const struct sockaddr_in6 *sa, 1454 struct printf_spec spec, const char *fmt) 1455 { 1456 bool have_p = false, have_s = false, have_f = false, have_c = false; 1457 char ip6_addr[sizeof("[xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255]") + 1458 sizeof(":12345") + sizeof("/123456789") + 1459 sizeof("%1234567890")]; 1460 char *p = ip6_addr, *pend = ip6_addr + sizeof(ip6_addr); 1461 const u8 *addr = (const u8 *) &sa->sin6_addr; 1462 char fmt6[2] = { fmt[0], '6' }; 1463 u8 off = 0; 1464 1465 fmt++; 1466 while (isalpha(*++fmt)) { 1467 switch (*fmt) { 1468 case 'p': 1469 have_p = true; 1470 break; 1471 case 'f': 1472 have_f = true; 1473 break; 1474 case 's': 1475 have_s = true; 1476 break; 1477 case 'c': 1478 have_c = true; 1479 break; 1480 } 1481 } 1482 1483 if (have_p || have_s || have_f) { 1484 *p = '['; 1485 off = 1; 1486 } 1487 1488 if (fmt6[0] == 'I' && have_c) 1489 p = ip6_compressed_string(ip6_addr + off, addr); 1490 else 1491 p = ip6_string(ip6_addr + off, addr, fmt6); 1492 1493 if (have_p || have_s || have_f) 1494 *p++ = ']'; 1495 1496 if (have_p) { 1497 *p++ = ':'; 1498 p = number(p, pend, ntohs(sa->sin6_port), spec); 1499 } 1500 if (have_f) { 1501 *p++ = '/'; 1502 p = number(p, pend, ntohl(sa->sin6_flowinfo & 1503 IPV6_FLOWINFO_MASK), spec); 1504 } 1505 if (have_s) { 1506 *p++ = '%'; 1507 p = number(p, pend, sa->sin6_scope_id, spec); 1508 } 1509 *p = '\0'; 1510 1511 return string_nocheck(buf, end, ip6_addr, spec); 1512 } 1513 1514 static noinline_for_stack 1515 char *ip4_addr_string_sa(char *buf, char *end, const struct sockaddr_in *sa, 1516 struct printf_spec spec, const char *fmt) 1517 { 1518 bool have_p = false; 1519 char *p, ip4_addr[sizeof("255.255.255.255") + sizeof(":12345")]; 1520 char *pend = ip4_addr + sizeof(ip4_addr); 1521 const u8 *addr = (const u8 *) &sa->sin_addr.s_addr; 1522 char fmt4[3] = { fmt[0], '4', 0 }; 1523 1524 fmt++; 1525 while (isalpha(*++fmt)) { 1526 switch (*fmt) { 1527 case 'p': 1528 have_p = true; 1529 break; 1530 case 'h': 1531 case 'l': 1532 case 'n': 1533 case 'b': 1534 fmt4[2] = *fmt; 1535 break; 1536 } 1537 } 1538 1539 p = ip4_string(ip4_addr, addr, fmt4); 1540 if (have_p) { 1541 *p++ = ':'; 1542 p = number(p, pend, ntohs(sa->sin_port), spec); 1543 } 1544 *p = '\0'; 1545 1546 return string_nocheck(buf, end, ip4_addr, spec); 1547 } 1548 1549 static noinline_for_stack 1550 char *ip_addr_string(char *buf, char *end, const void *ptr, 1551 struct printf_spec spec, const char *fmt) 1552 { 1553 char *err_fmt_msg; 1554 1555 if (check_pointer(&buf, end, ptr, spec)) 1556 return buf; 1557 1558 switch (fmt[1]) { 1559 case '6': 1560 return ip6_addr_string(buf, end, ptr, spec, fmt); 1561 case '4': 1562 return ip4_addr_string(buf, end, ptr, spec, fmt); 1563 case 'S': { 1564 const union { 1565 struct sockaddr raw; 1566 struct sockaddr_in v4; 1567 struct sockaddr_in6 v6; 1568 } *sa = ptr; 1569 1570 switch (sa->raw.sa_family) { 1571 case AF_INET: 1572 return ip4_addr_string_sa(buf, end, &sa->v4, spec, fmt); 1573 case AF_INET6: 1574 return ip6_addr_string_sa(buf, end, &sa->v6, spec, fmt); 1575 default: 1576 return error_string(buf, end, "(einval)", spec); 1577 }} 1578 } 1579 1580 err_fmt_msg = fmt[0] == 'i' ? "(%pi?)" : "(%pI?)"; 1581 return error_string(buf, end, err_fmt_msg, spec); 1582 } 1583 1584 static noinline_for_stack 1585 char *escaped_string(char *buf, char *end, u8 *addr, struct printf_spec spec, 1586 const char *fmt) 1587 { 1588 bool found = true; 1589 int count = 1; 1590 unsigned int flags = 0; 1591 int len; 1592 1593 if (spec.field_width == 0) 1594 return buf; /* nothing to print */ 1595 1596 if (check_pointer(&buf, end, addr, spec)) 1597 return buf; 1598 1599 do { 1600 switch (fmt[count++]) { 1601 case 'a': 1602 flags |= ESCAPE_ANY; 1603 break; 1604 case 'c': 1605 flags |= ESCAPE_SPECIAL; 1606 break; 1607 case 'h': 1608 flags |= ESCAPE_HEX; 1609 break; 1610 case 'n': 1611 flags |= ESCAPE_NULL; 1612 break; 1613 case 'o': 1614 flags |= ESCAPE_OCTAL; 1615 break; 1616 case 'p': 1617 flags |= ESCAPE_NP; 1618 break; 1619 case 's': 1620 flags |= ESCAPE_SPACE; 1621 break; 1622 default: 1623 found = false; 1624 break; 1625 } 1626 } while (found); 1627 1628 if (!flags) 1629 flags = ESCAPE_ANY_NP; 1630 1631 len = spec.field_width < 0 ? 1 : spec.field_width; 1632 1633 /* 1634 * string_escape_mem() writes as many characters as it can to 1635 * the given buffer, and returns the total size of the output 1636 * had the buffer been big enough. 1637 */ 1638 buf += string_escape_mem(addr, len, buf, buf < end ? end - buf : 0, flags, NULL); 1639 1640 return buf; 1641 } 1642 1643 static char *va_format(char *buf, char *end, struct va_format *va_fmt, 1644 struct printf_spec spec, const char *fmt) 1645 { 1646 va_list va; 1647 1648 if (check_pointer(&buf, end, va_fmt, spec)) 1649 return buf; 1650 1651 va_copy(va, *va_fmt->va); 1652 buf += vsnprintf(buf, end > buf ? end - buf : 0, va_fmt->fmt, va); 1653 va_end(va); 1654 1655 return buf; 1656 } 1657 1658 static noinline_for_stack 1659 char *uuid_string(char *buf, char *end, const u8 *addr, 1660 struct printf_spec spec, const char *fmt) 1661 { 1662 char uuid[UUID_STRING_LEN + 1]; 1663 char *p = uuid; 1664 int i; 1665 const u8 *index = uuid_index; 1666 bool uc = false; 1667 1668 if (check_pointer(&buf, end, addr, spec)) 1669 return buf; 1670 1671 switch (*(++fmt)) { 1672 case 'L': 1673 uc = true; /* fall-through */ 1674 case 'l': 1675 index = guid_index; 1676 break; 1677 case 'B': 1678 uc = true; 1679 break; 1680 } 1681 1682 for (i = 0; i < 16; i++) { 1683 if (uc) 1684 p = hex_byte_pack_upper(p, addr[index[i]]); 1685 else 1686 p = hex_byte_pack(p, addr[index[i]]); 1687 switch (i) { 1688 case 3: 1689 case 5: 1690 case 7: 1691 case 9: 1692 *p++ = '-'; 1693 break; 1694 } 1695 } 1696 1697 *p = 0; 1698 1699 return string_nocheck(buf, end, uuid, spec); 1700 } 1701 1702 static noinline_for_stack 1703 char *netdev_bits(char *buf, char *end, const void *addr, 1704 struct printf_spec spec, const char *fmt) 1705 { 1706 unsigned long long num; 1707 int size; 1708 1709 if (check_pointer(&buf, end, addr, spec)) 1710 return buf; 1711 1712 switch (fmt[1]) { 1713 case 'F': 1714 num = *(const netdev_features_t *)addr; 1715 size = sizeof(netdev_features_t); 1716 break; 1717 default: 1718 return error_string(buf, end, "(%pN?)", spec); 1719 } 1720 1721 return special_hex_number(buf, end, num, size); 1722 } 1723 1724 static noinline_for_stack 1725 char *address_val(char *buf, char *end, const void *addr, 1726 struct printf_spec spec, const char *fmt) 1727 { 1728 unsigned long long num; 1729 int size; 1730 1731 if (check_pointer(&buf, end, addr, spec)) 1732 return buf; 1733 1734 switch (fmt[1]) { 1735 case 'd': 1736 num = *(const dma_addr_t *)addr; 1737 size = sizeof(dma_addr_t); 1738 break; 1739 case 'p': 1740 default: 1741 num = *(const phys_addr_t *)addr; 1742 size = sizeof(phys_addr_t); 1743 break; 1744 } 1745 1746 return special_hex_number(buf, end, num, size); 1747 } 1748 1749 static noinline_for_stack 1750 char *date_str(char *buf, char *end, const struct rtc_time *tm, bool r) 1751 { 1752 int year = tm->tm_year + (r ? 0 : 1900); 1753 int mon = tm->tm_mon + (r ? 0 : 1); 1754 1755 buf = number(buf, end, year, default_dec04_spec); 1756 if (buf < end) 1757 *buf = '-'; 1758 buf++; 1759 1760 buf = number(buf, end, mon, default_dec02_spec); 1761 if (buf < end) 1762 *buf = '-'; 1763 buf++; 1764 1765 return number(buf, end, tm->tm_mday, default_dec02_spec); 1766 } 1767 1768 static noinline_for_stack 1769 char *time_str(char *buf, char *end, const struct rtc_time *tm, bool r) 1770 { 1771 buf = number(buf, end, tm->tm_hour, default_dec02_spec); 1772 if (buf < end) 1773 *buf = ':'; 1774 buf++; 1775 1776 buf = number(buf, end, tm->tm_min, default_dec02_spec); 1777 if (buf < end) 1778 *buf = ':'; 1779 buf++; 1780 1781 return number(buf, end, tm->tm_sec, default_dec02_spec); 1782 } 1783 1784 static noinline_for_stack 1785 char *rtc_str(char *buf, char *end, const struct rtc_time *tm, 1786 struct printf_spec spec, const char *fmt) 1787 { 1788 bool have_t = true, have_d = true; 1789 bool raw = false; 1790 int count = 2; 1791 1792 if (check_pointer(&buf, end, tm, spec)) 1793 return buf; 1794 1795 switch (fmt[count]) { 1796 case 'd': 1797 have_t = false; 1798 count++; 1799 break; 1800 case 't': 1801 have_d = false; 1802 count++; 1803 break; 1804 } 1805 1806 raw = fmt[count] == 'r'; 1807 1808 if (have_d) 1809 buf = date_str(buf, end, tm, raw); 1810 if (have_d && have_t) { 1811 /* Respect ISO 8601 */ 1812 if (buf < end) 1813 *buf = 'T'; 1814 buf++; 1815 } 1816 if (have_t) 1817 buf = time_str(buf, end, tm, raw); 1818 1819 return buf; 1820 } 1821 1822 static noinline_for_stack 1823 char *time_and_date(char *buf, char *end, void *ptr, struct printf_spec spec, 1824 const char *fmt) 1825 { 1826 switch (fmt[1]) { 1827 case 'R': 1828 return rtc_str(buf, end, (const struct rtc_time *)ptr, spec, fmt); 1829 default: 1830 return error_string(buf, end, "(%ptR?)", spec); 1831 } 1832 } 1833 1834 static noinline_for_stack 1835 char *clock(char *buf, char *end, struct clk *clk, struct printf_spec spec, 1836 const char *fmt) 1837 { 1838 if (!IS_ENABLED(CONFIG_HAVE_CLK)) 1839 return error_string(buf, end, "(%pC?)", spec); 1840 1841 if (check_pointer(&buf, end, clk, spec)) 1842 return buf; 1843 1844 switch (fmt[1]) { 1845 case 'n': 1846 default: 1847 #ifdef CONFIG_COMMON_CLK 1848 return string(buf, end, __clk_get_name(clk), spec); 1849 #else 1850 return ptr_to_id(buf, end, clk, spec); 1851 #endif 1852 } 1853 } 1854 1855 static 1856 char *format_flags(char *buf, char *end, unsigned long flags, 1857 const struct trace_print_flags *names) 1858 { 1859 unsigned long mask; 1860 1861 for ( ; flags && names->name; names++) { 1862 mask = names->mask; 1863 if ((flags & mask) != mask) 1864 continue; 1865 1866 buf = string(buf, end, names->name, default_str_spec); 1867 1868 flags &= ~mask; 1869 if (flags) { 1870 if (buf < end) 1871 *buf = '|'; 1872 buf++; 1873 } 1874 } 1875 1876 if (flags) 1877 buf = number(buf, end, flags, default_flag_spec); 1878 1879 return buf; 1880 } 1881 1882 static noinline_for_stack 1883 char *flags_string(char *buf, char *end, void *flags_ptr, 1884 struct printf_spec spec, const char *fmt) 1885 { 1886 unsigned long flags; 1887 const struct trace_print_flags *names; 1888 1889 if (check_pointer(&buf, end, flags_ptr, spec)) 1890 return buf; 1891 1892 switch (fmt[1]) { 1893 case 'p': 1894 flags = *(unsigned long *)flags_ptr; 1895 /* Remove zone id */ 1896 flags &= (1UL << NR_PAGEFLAGS) - 1; 1897 names = pageflag_names; 1898 break; 1899 case 'v': 1900 flags = *(unsigned long *)flags_ptr; 1901 names = vmaflag_names; 1902 break; 1903 case 'g': 1904 flags = *(gfp_t *)flags_ptr; 1905 names = gfpflag_names; 1906 break; 1907 default: 1908 return error_string(buf, end, "(%pG?)", spec); 1909 } 1910 1911 return format_flags(buf, end, flags, names); 1912 } 1913 1914 static noinline_for_stack 1915 char *fwnode_full_name_string(struct fwnode_handle *fwnode, char *buf, 1916 char *end) 1917 { 1918 int depth; 1919 1920 /* Loop starting from the root node to the current node. */ 1921 for (depth = fwnode_count_parents(fwnode); depth >= 0; depth--) { 1922 struct fwnode_handle *__fwnode = 1923 fwnode_get_nth_parent(fwnode, depth); 1924 1925 buf = string(buf, end, fwnode_get_name_prefix(__fwnode), 1926 default_str_spec); 1927 buf = string(buf, end, fwnode_get_name(__fwnode), 1928 default_str_spec); 1929 1930 fwnode_handle_put(__fwnode); 1931 } 1932 1933 return buf; 1934 } 1935 1936 static noinline_for_stack 1937 char *device_node_string(char *buf, char *end, struct device_node *dn, 1938 struct printf_spec spec, const char *fmt) 1939 { 1940 char tbuf[sizeof("xxxx") + 1]; 1941 const char *p; 1942 int ret; 1943 char *buf_start = buf; 1944 struct property *prop; 1945 bool has_mult, pass; 1946 static const struct printf_spec num_spec = { 1947 .flags = SMALL, 1948 .field_width = -1, 1949 .precision = -1, 1950 .base = 10, 1951 }; 1952 1953 struct printf_spec str_spec = spec; 1954 str_spec.field_width = -1; 1955 1956 if (fmt[0] != 'F') 1957 return error_string(buf, end, "(%pO?)", spec); 1958 1959 if (!IS_ENABLED(CONFIG_OF)) 1960 return error_string(buf, end, "(%pOF?)", spec); 1961 1962 if (check_pointer(&buf, end, dn, spec)) 1963 return buf; 1964 1965 /* simple case without anything any more format specifiers */ 1966 fmt++; 1967 if (fmt[0] == '\0' || strcspn(fmt,"fnpPFcC") > 0) 1968 fmt = "f"; 1969 1970 for (pass = false; strspn(fmt,"fnpPFcC"); fmt++, pass = true) { 1971 int precision; 1972 if (pass) { 1973 if (buf < end) 1974 *buf = ':'; 1975 buf++; 1976 } 1977 1978 switch (*fmt) { 1979 case 'f': /* full_name */ 1980 buf = fwnode_full_name_string(of_fwnode_handle(dn), buf, 1981 end); 1982 break; 1983 case 'n': /* name */ 1984 p = fwnode_get_name(of_fwnode_handle(dn)); 1985 precision = str_spec.precision; 1986 str_spec.precision = strchrnul(p, '@') - p; 1987 buf = string(buf, end, p, str_spec); 1988 str_spec.precision = precision; 1989 break; 1990 case 'p': /* phandle */ 1991 buf = number(buf, end, (unsigned int)dn->phandle, num_spec); 1992 break; 1993 case 'P': /* path-spec */ 1994 p = fwnode_get_name(of_fwnode_handle(dn)); 1995 if (!p[1]) 1996 p = "/"; 1997 buf = string(buf, end, p, str_spec); 1998 break; 1999 case 'F': /* flags */ 2000 tbuf[0] = of_node_check_flag(dn, OF_DYNAMIC) ? 'D' : '-'; 2001 tbuf[1] = of_node_check_flag(dn, OF_DETACHED) ? 'd' : '-'; 2002 tbuf[2] = of_node_check_flag(dn, OF_POPULATED) ? 'P' : '-'; 2003 tbuf[3] = of_node_check_flag(dn, OF_POPULATED_BUS) ? 'B' : '-'; 2004 tbuf[4] = 0; 2005 buf = string_nocheck(buf, end, tbuf, str_spec); 2006 break; 2007 case 'c': /* major compatible string */ 2008 ret = of_property_read_string(dn, "compatible", &p); 2009 if (!ret) 2010 buf = string(buf, end, p, str_spec); 2011 break; 2012 case 'C': /* full compatible string */ 2013 has_mult = false; 2014 of_property_for_each_string(dn, "compatible", prop, p) { 2015 if (has_mult) 2016 buf = string_nocheck(buf, end, ",", str_spec); 2017 buf = string_nocheck(buf, end, "\"", str_spec); 2018 buf = string(buf, end, p, str_spec); 2019 buf = string_nocheck(buf, end, "\"", str_spec); 2020 2021 has_mult = true; 2022 } 2023 break; 2024 default: 2025 break; 2026 } 2027 } 2028 2029 return widen_string(buf, buf - buf_start, end, spec); 2030 } 2031 2032 static noinline_for_stack 2033 char *fwnode_string(char *buf, char *end, struct fwnode_handle *fwnode, 2034 struct printf_spec spec, const char *fmt) 2035 { 2036 struct printf_spec str_spec = spec; 2037 char *buf_start = buf; 2038 2039 str_spec.field_width = -1; 2040 2041 if (*fmt != 'w') 2042 return error_string(buf, end, "(%pf?)", spec); 2043 2044 if (check_pointer(&buf, end, fwnode, spec)) 2045 return buf; 2046 2047 fmt++; 2048 2049 switch (*fmt) { 2050 case 'P': /* name */ 2051 buf = string(buf, end, fwnode_get_name(fwnode), str_spec); 2052 break; 2053 case 'f': /* full_name */ 2054 default: 2055 buf = fwnode_full_name_string(fwnode, buf, end); 2056 break; 2057 } 2058 2059 return widen_string(buf, buf - buf_start, end, spec); 2060 } 2061 2062 /* 2063 * Show a '%p' thing. A kernel extension is that the '%p' is followed 2064 * by an extra set of alphanumeric characters that are extended format 2065 * specifiers. 2066 * 2067 * Please update scripts/checkpatch.pl when adding/removing conversion 2068 * characters. (Search for "check for vsprintf extension"). 2069 * 2070 * Right now we handle: 2071 * 2072 * - 'S' For symbolic direct pointers (or function descriptors) with offset 2073 * - 's' For symbolic direct pointers (or function descriptors) without offset 2074 * - '[Ss]R' as above with __builtin_extract_return_addr() translation 2075 * - '[Ff]' %pf and %pF were obsoleted and later removed in favor of 2076 * %ps and %pS. Be careful when re-using these specifiers. 2077 * - 'B' For backtraced symbolic direct pointers with offset 2078 * - 'R' For decoded struct resource, e.g., [mem 0x0-0x1f 64bit pref] 2079 * - 'r' For raw struct resource, e.g., [mem 0x0-0x1f flags 0x201] 2080 * - 'b[l]' For a bitmap, the number of bits is determined by the field 2081 * width which must be explicitly specified either as part of the 2082 * format string '%32b[l]' or through '%*b[l]', [l] selects 2083 * range-list format instead of hex format 2084 * - 'M' For a 6-byte MAC address, it prints the address in the 2085 * usual colon-separated hex notation 2086 * - 'm' For a 6-byte MAC address, it prints the hex address without colons 2087 * - 'MF' For a 6-byte MAC FDDI address, it prints the address 2088 * with a dash-separated hex notation 2089 * - '[mM]R' For a 6-byte MAC address, Reverse order (Bluetooth) 2090 * - 'I' [46] for IPv4/IPv6 addresses printed in the usual way 2091 * IPv4 uses dot-separated decimal without leading 0's (1.2.3.4) 2092 * IPv6 uses colon separated network-order 16 bit hex with leading 0's 2093 * [S][pfs] 2094 * Generic IPv4/IPv6 address (struct sockaddr *) that falls back to 2095 * [4] or [6] and is able to print port [p], flowinfo [f], scope [s] 2096 * - 'i' [46] for 'raw' IPv4/IPv6 addresses 2097 * IPv6 omits the colons (01020304...0f) 2098 * IPv4 uses dot-separated decimal with leading 0's (010.123.045.006) 2099 * [S][pfs] 2100 * Generic IPv4/IPv6 address (struct sockaddr *) that falls back to 2101 * [4] or [6] and is able to print port [p], flowinfo [f], scope [s] 2102 * - '[Ii][4S][hnbl]' IPv4 addresses in host, network, big or little endian order 2103 * - 'I[6S]c' for IPv6 addresses printed as specified by 2104 * http://tools.ietf.org/html/rfc5952 2105 * - 'E[achnops]' For an escaped buffer, where rules are defined by combination 2106 * of the following flags (see string_escape_mem() for the 2107 * details): 2108 * a - ESCAPE_ANY 2109 * c - ESCAPE_SPECIAL 2110 * h - ESCAPE_HEX 2111 * n - ESCAPE_NULL 2112 * o - ESCAPE_OCTAL 2113 * p - ESCAPE_NP 2114 * s - ESCAPE_SPACE 2115 * By default ESCAPE_ANY_NP is used. 2116 * - 'U' For a 16 byte UUID/GUID, it prints the UUID/GUID in the form 2117 * "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx" 2118 * Options for %pU are: 2119 * b big endian lower case hex (default) 2120 * B big endian UPPER case hex 2121 * l little endian lower case hex 2122 * L little endian UPPER case hex 2123 * big endian output byte order is: 2124 * [0][1][2][3]-[4][5]-[6][7]-[8][9]-[10][11][12][13][14][15] 2125 * little endian output byte order is: 2126 * [3][2][1][0]-[5][4]-[7][6]-[8][9]-[10][11][12][13][14][15] 2127 * - 'V' For a struct va_format which contains a format string * and va_list *, 2128 * call vsnprintf(->format, *->va_list). 2129 * Implements a "recursive vsnprintf". 2130 * Do not use this feature without some mechanism to verify the 2131 * correctness of the format string and va_list arguments. 2132 * - 'K' For a kernel pointer that should be hidden from unprivileged users 2133 * - 'NF' For a netdev_features_t 2134 * - 'h[CDN]' For a variable-length buffer, it prints it as a hex string with 2135 * a certain separator (' ' by default): 2136 * C colon 2137 * D dash 2138 * N no separator 2139 * The maximum supported length is 64 bytes of the input. Consider 2140 * to use print_hex_dump() for the larger input. 2141 * - 'a[pd]' For address types [p] phys_addr_t, [d] dma_addr_t and derivatives 2142 * (default assumed to be phys_addr_t, passed by reference) 2143 * - 'd[234]' For a dentry name (optionally 2-4 last components) 2144 * - 'D[234]' Same as 'd' but for a struct file 2145 * - 'g' For block_device name (gendisk + partition number) 2146 * - 't[R][dt][r]' For time and date as represented: 2147 * R struct rtc_time 2148 * - 'C' For a clock, it prints the name (Common Clock Framework) or address 2149 * (legacy clock framework) of the clock 2150 * - 'Cn' For a clock, it prints the name (Common Clock Framework) or address 2151 * (legacy clock framework) of the clock 2152 * - 'G' For flags to be printed as a collection of symbolic strings that would 2153 * construct the specific value. Supported flags given by option: 2154 * p page flags (see struct page) given as pointer to unsigned long 2155 * g gfp flags (GFP_* and __GFP_*) given as pointer to gfp_t 2156 * v vma flags (VM_*) given as pointer to unsigned long 2157 * - 'OF[fnpPcCF]' For a device tree object 2158 * Without any optional arguments prints the full_name 2159 * f device node full_name 2160 * n device node name 2161 * p device node phandle 2162 * P device node path spec (name + @unit) 2163 * F device node flags 2164 * c major compatible string 2165 * C full compatible string 2166 * - 'fw[fP]' For a firmware node (struct fwnode_handle) pointer 2167 * Without an option prints the full name of the node 2168 * f full name 2169 * P node name, including a possible unit address 2170 * - 'x' For printing the address. Equivalent to "%lx". 2171 * 2172 * ** When making changes please also update: 2173 * Documentation/core-api/printk-formats.rst 2174 * 2175 * Note: The default behaviour (unadorned %p) is to hash the address, 2176 * rendering it useful as a unique identifier. 2177 */ 2178 static noinline_for_stack 2179 char *pointer(const char *fmt, char *buf, char *end, void *ptr, 2180 struct printf_spec spec) 2181 { 2182 switch (*fmt) { 2183 case 'S': 2184 case 's': 2185 ptr = dereference_symbol_descriptor(ptr); 2186 /* Fallthrough */ 2187 case 'B': 2188 return symbol_string(buf, end, ptr, spec, fmt); 2189 case 'R': 2190 case 'r': 2191 return resource_string(buf, end, ptr, spec, fmt); 2192 case 'h': 2193 return hex_string(buf, end, ptr, spec, fmt); 2194 case 'b': 2195 switch (fmt[1]) { 2196 case 'l': 2197 return bitmap_list_string(buf, end, ptr, spec, fmt); 2198 default: 2199 return bitmap_string(buf, end, ptr, spec, fmt); 2200 } 2201 case 'M': /* Colon separated: 00:01:02:03:04:05 */ 2202 case 'm': /* Contiguous: 000102030405 */ 2203 /* [mM]F (FDDI) */ 2204 /* [mM]R (Reverse order; Bluetooth) */ 2205 return mac_address_string(buf, end, ptr, spec, fmt); 2206 case 'I': /* Formatted IP supported 2207 * 4: 1.2.3.4 2208 * 6: 0001:0203:...:0708 2209 * 6c: 1::708 or 1::1.2.3.4 2210 */ 2211 case 'i': /* Contiguous: 2212 * 4: 001.002.003.004 2213 * 6: 000102...0f 2214 */ 2215 return ip_addr_string(buf, end, ptr, spec, fmt); 2216 case 'E': 2217 return escaped_string(buf, end, ptr, spec, fmt); 2218 case 'U': 2219 return uuid_string(buf, end, ptr, spec, fmt); 2220 case 'V': 2221 return va_format(buf, end, ptr, spec, fmt); 2222 case 'K': 2223 return restricted_pointer(buf, end, ptr, spec); 2224 case 'N': 2225 return netdev_bits(buf, end, ptr, spec, fmt); 2226 case 'a': 2227 return address_val(buf, end, ptr, spec, fmt); 2228 case 'd': 2229 return dentry_name(buf, end, ptr, spec, fmt); 2230 case 't': 2231 return time_and_date(buf, end, ptr, spec, fmt); 2232 case 'C': 2233 return clock(buf, end, ptr, spec, fmt); 2234 case 'D': 2235 return file_dentry_name(buf, end, ptr, spec, fmt); 2236 #ifdef CONFIG_BLOCK 2237 case 'g': 2238 return bdev_name(buf, end, ptr, spec, fmt); 2239 #endif 2240 2241 case 'G': 2242 return flags_string(buf, end, ptr, spec, fmt); 2243 case 'O': 2244 return device_node_string(buf, end, ptr, spec, fmt + 1); 2245 case 'f': 2246 return fwnode_string(buf, end, ptr, spec, fmt + 1); 2247 case 'x': 2248 return pointer_string(buf, end, ptr, spec); 2249 case 'e': 2250 /* %pe with a non-ERR_PTR gets treated as plain %p */ 2251 if (!IS_ERR(ptr)) 2252 break; 2253 return err_ptr(buf, end, ptr, spec); 2254 } 2255 2256 /* default is to _not_ leak addresses, hash before printing */ 2257 return ptr_to_id(buf, end, ptr, spec); 2258 } 2259 2260 /* 2261 * Helper function to decode printf style format. 2262 * Each call decode a token from the format and return the 2263 * number of characters read (or likely the delta where it wants 2264 * to go on the next call). 2265 * The decoded token is returned through the parameters 2266 * 2267 * 'h', 'l', or 'L' for integer fields 2268 * 'z' support added 23/7/1999 S.H. 2269 * 'z' changed to 'Z' --davidm 1/25/99 2270 * 'Z' changed to 'z' --adobriyan 2017-01-25 2271 * 't' added for ptrdiff_t 2272 * 2273 * @fmt: the format string 2274 * @type of the token returned 2275 * @flags: various flags such as +, -, # tokens.. 2276 * @field_width: overwritten width 2277 * @base: base of the number (octal, hex, ...) 2278 * @precision: precision of a number 2279 * @qualifier: qualifier of a number (long, size_t, ...) 2280 */ 2281 static noinline_for_stack 2282 int format_decode(const char *fmt, struct printf_spec *spec) 2283 { 2284 const char *start = fmt; 2285 char qualifier; 2286 2287 /* we finished early by reading the field width */ 2288 if (spec->type == FORMAT_TYPE_WIDTH) { 2289 if (spec->field_width < 0) { 2290 spec->field_width = -spec->field_width; 2291 spec->flags |= LEFT; 2292 } 2293 spec->type = FORMAT_TYPE_NONE; 2294 goto precision; 2295 } 2296 2297 /* we finished early by reading the precision */ 2298 if (spec->type == FORMAT_TYPE_PRECISION) { 2299 if (spec->precision < 0) 2300 spec->precision = 0; 2301 2302 spec->type = FORMAT_TYPE_NONE; 2303 goto qualifier; 2304 } 2305 2306 /* By default */ 2307 spec->type = FORMAT_TYPE_NONE; 2308 2309 for (; *fmt ; ++fmt) { 2310 if (*fmt == '%') 2311 break; 2312 } 2313 2314 /* Return the current non-format string */ 2315 if (fmt != start || !*fmt) 2316 return fmt - start; 2317 2318 /* Process flags */ 2319 spec->flags = 0; 2320 2321 while (1) { /* this also skips first '%' */ 2322 bool found = true; 2323 2324 ++fmt; 2325 2326 switch (*fmt) { 2327 case '-': spec->flags |= LEFT; break; 2328 case '+': spec->flags |= PLUS; break; 2329 case ' ': spec->flags |= SPACE; break; 2330 case '#': spec->flags |= SPECIAL; break; 2331 case '0': spec->flags |= ZEROPAD; break; 2332 default: found = false; 2333 } 2334 2335 if (!found) 2336 break; 2337 } 2338 2339 /* get field width */ 2340 spec->field_width = -1; 2341 2342 if (isdigit(*fmt)) 2343 spec->field_width = skip_atoi(&fmt); 2344 else if (*fmt == '*') { 2345 /* it's the next argument */ 2346 spec->type = FORMAT_TYPE_WIDTH; 2347 return ++fmt - start; 2348 } 2349 2350 precision: 2351 /* get the precision */ 2352 spec->precision = -1; 2353 if (*fmt == '.') { 2354 ++fmt; 2355 if (isdigit(*fmt)) { 2356 spec->precision = skip_atoi(&fmt); 2357 if (spec->precision < 0) 2358 spec->precision = 0; 2359 } else if (*fmt == '*') { 2360 /* it's the next argument */ 2361 spec->type = FORMAT_TYPE_PRECISION; 2362 return ++fmt - start; 2363 } 2364 } 2365 2366 qualifier: 2367 /* get the conversion qualifier */ 2368 qualifier = 0; 2369 if (*fmt == 'h' || _tolower(*fmt) == 'l' || 2370 *fmt == 'z' || *fmt == 't') { 2371 qualifier = *fmt++; 2372 if (unlikely(qualifier == *fmt)) { 2373 if (qualifier == 'l') { 2374 qualifier = 'L'; 2375 ++fmt; 2376 } else if (qualifier == 'h') { 2377 qualifier = 'H'; 2378 ++fmt; 2379 } 2380 } 2381 } 2382 2383 /* default base */ 2384 spec->base = 10; 2385 switch (*fmt) { 2386 case 'c': 2387 spec->type = FORMAT_TYPE_CHAR; 2388 return ++fmt - start; 2389 2390 case 's': 2391 spec->type = FORMAT_TYPE_STR; 2392 return ++fmt - start; 2393 2394 case 'p': 2395 spec->type = FORMAT_TYPE_PTR; 2396 return ++fmt - start; 2397 2398 case '%': 2399 spec->type = FORMAT_TYPE_PERCENT_CHAR; 2400 return ++fmt - start; 2401 2402 /* integer number formats - set up the flags and "break" */ 2403 case 'o': 2404 spec->base = 8; 2405 break; 2406 2407 case 'x': 2408 spec->flags |= SMALL; 2409 /* fall through */ 2410 2411 case 'X': 2412 spec->base = 16; 2413 break; 2414 2415 case 'd': 2416 case 'i': 2417 spec->flags |= SIGN; 2418 case 'u': 2419 break; 2420 2421 case 'n': 2422 /* 2423 * Since %n poses a greater security risk than 2424 * utility, treat it as any other invalid or 2425 * unsupported format specifier. 2426 */ 2427 /* Fall-through */ 2428 2429 default: 2430 WARN_ONCE(1, "Please remove unsupported %%%c in format string\n", *fmt); 2431 spec->type = FORMAT_TYPE_INVALID; 2432 return fmt - start; 2433 } 2434 2435 if (qualifier == 'L') 2436 spec->type = FORMAT_TYPE_LONG_LONG; 2437 else if (qualifier == 'l') { 2438 BUILD_BUG_ON(FORMAT_TYPE_ULONG + SIGN != FORMAT_TYPE_LONG); 2439 spec->type = FORMAT_TYPE_ULONG + (spec->flags & SIGN); 2440 } else if (qualifier == 'z') { 2441 spec->type = FORMAT_TYPE_SIZE_T; 2442 } else if (qualifier == 't') { 2443 spec->type = FORMAT_TYPE_PTRDIFF; 2444 } else if (qualifier == 'H') { 2445 BUILD_BUG_ON(FORMAT_TYPE_UBYTE + SIGN != FORMAT_TYPE_BYTE); 2446 spec->type = FORMAT_TYPE_UBYTE + (spec->flags & SIGN); 2447 } else if (qualifier == 'h') { 2448 BUILD_BUG_ON(FORMAT_TYPE_USHORT + SIGN != FORMAT_TYPE_SHORT); 2449 spec->type = FORMAT_TYPE_USHORT + (spec->flags & SIGN); 2450 } else { 2451 BUILD_BUG_ON(FORMAT_TYPE_UINT + SIGN != FORMAT_TYPE_INT); 2452 spec->type = FORMAT_TYPE_UINT + (spec->flags & SIGN); 2453 } 2454 2455 return ++fmt - start; 2456 } 2457 2458 static void 2459 set_field_width(struct printf_spec *spec, int width) 2460 { 2461 spec->field_width = width; 2462 if (WARN_ONCE(spec->field_width != width, "field width %d too large", width)) { 2463 spec->field_width = clamp(width, -FIELD_WIDTH_MAX, FIELD_WIDTH_MAX); 2464 } 2465 } 2466 2467 static void 2468 set_precision(struct printf_spec *spec, int prec) 2469 { 2470 spec->precision = prec; 2471 if (WARN_ONCE(spec->precision != prec, "precision %d too large", prec)) { 2472 spec->precision = clamp(prec, 0, PRECISION_MAX); 2473 } 2474 } 2475 2476 /** 2477 * vsnprintf - Format a string and place it in a buffer 2478 * @buf: The buffer to place the result into 2479 * @size: The size of the buffer, including the trailing null space 2480 * @fmt: The format string to use 2481 * @args: Arguments for the format string 2482 * 2483 * This function generally follows C99 vsnprintf, but has some 2484 * extensions and a few limitations: 2485 * 2486 * - ``%n`` is unsupported 2487 * - ``%p*`` is handled by pointer() 2488 * 2489 * See pointer() or Documentation/core-api/printk-formats.rst for more 2490 * extensive description. 2491 * 2492 * **Please update the documentation in both places when making changes** 2493 * 2494 * The return value is the number of characters which would 2495 * be generated for the given input, excluding the trailing 2496 * '\0', as per ISO C99. If you want to have the exact 2497 * number of characters written into @buf as return value 2498 * (not including the trailing '\0'), use vscnprintf(). If the 2499 * return is greater than or equal to @size, the resulting 2500 * string is truncated. 2501 * 2502 * If you're not already dealing with a va_list consider using snprintf(). 2503 */ 2504 int vsnprintf(char *buf, size_t size, const char *fmt, va_list args) 2505 { 2506 unsigned long long num; 2507 char *str, *end; 2508 struct printf_spec spec = {0}; 2509 2510 /* Reject out-of-range values early. Large positive sizes are 2511 used for unknown buffer sizes. */ 2512 if (WARN_ON_ONCE(size > INT_MAX)) 2513 return 0; 2514 2515 str = buf; 2516 end = buf + size; 2517 2518 /* Make sure end is always >= buf */ 2519 if (end < buf) { 2520 end = ((void *)-1); 2521 size = end - buf; 2522 } 2523 2524 while (*fmt) { 2525 const char *old_fmt = fmt; 2526 int read = format_decode(fmt, &spec); 2527 2528 fmt += read; 2529 2530 switch (spec.type) { 2531 case FORMAT_TYPE_NONE: { 2532 int copy = read; 2533 if (str < end) { 2534 if (copy > end - str) 2535 copy = end - str; 2536 memcpy(str, old_fmt, copy); 2537 } 2538 str += read; 2539 break; 2540 } 2541 2542 case FORMAT_TYPE_WIDTH: 2543 set_field_width(&spec, va_arg(args, int)); 2544 break; 2545 2546 case FORMAT_TYPE_PRECISION: 2547 set_precision(&spec, va_arg(args, int)); 2548 break; 2549 2550 case FORMAT_TYPE_CHAR: { 2551 char c; 2552 2553 if (!(spec.flags & LEFT)) { 2554 while (--spec.field_width > 0) { 2555 if (str < end) 2556 *str = ' '; 2557 ++str; 2558 2559 } 2560 } 2561 c = (unsigned char) va_arg(args, int); 2562 if (str < end) 2563 *str = c; 2564 ++str; 2565 while (--spec.field_width > 0) { 2566 if (str < end) 2567 *str = ' '; 2568 ++str; 2569 } 2570 break; 2571 } 2572 2573 case FORMAT_TYPE_STR: 2574 str = string(str, end, va_arg(args, char *), spec); 2575 break; 2576 2577 case FORMAT_TYPE_PTR: 2578 str = pointer(fmt, str, end, va_arg(args, void *), 2579 spec); 2580 while (isalnum(*fmt)) 2581 fmt++; 2582 break; 2583 2584 case FORMAT_TYPE_PERCENT_CHAR: 2585 if (str < end) 2586 *str = '%'; 2587 ++str; 2588 break; 2589 2590 case FORMAT_TYPE_INVALID: 2591 /* 2592 * Presumably the arguments passed gcc's type 2593 * checking, but there is no safe or sane way 2594 * for us to continue parsing the format and 2595 * fetching from the va_list; the remaining 2596 * specifiers and arguments would be out of 2597 * sync. 2598 */ 2599 goto out; 2600 2601 default: 2602 switch (spec.type) { 2603 case FORMAT_TYPE_LONG_LONG: 2604 num = va_arg(args, long long); 2605 break; 2606 case FORMAT_TYPE_ULONG: 2607 num = va_arg(args, unsigned long); 2608 break; 2609 case FORMAT_TYPE_LONG: 2610 num = va_arg(args, long); 2611 break; 2612 case FORMAT_TYPE_SIZE_T: 2613 if (spec.flags & SIGN) 2614 num = va_arg(args, ssize_t); 2615 else 2616 num = va_arg(args, size_t); 2617 break; 2618 case FORMAT_TYPE_PTRDIFF: 2619 num = va_arg(args, ptrdiff_t); 2620 break; 2621 case FORMAT_TYPE_UBYTE: 2622 num = (unsigned char) va_arg(args, int); 2623 break; 2624 case FORMAT_TYPE_BYTE: 2625 num = (signed char) va_arg(args, int); 2626 break; 2627 case FORMAT_TYPE_USHORT: 2628 num = (unsigned short) va_arg(args, int); 2629 break; 2630 case FORMAT_TYPE_SHORT: 2631 num = (short) va_arg(args, int); 2632 break; 2633 case FORMAT_TYPE_INT: 2634 num = (int) va_arg(args, int); 2635 break; 2636 default: 2637 num = va_arg(args, unsigned int); 2638 } 2639 2640 str = number(str, end, num, spec); 2641 } 2642 } 2643 2644 out: 2645 if (size > 0) { 2646 if (str < end) 2647 *str = '\0'; 2648 else 2649 end[-1] = '\0'; 2650 } 2651 2652 /* the trailing null byte doesn't count towards the total */ 2653 return str-buf; 2654 2655 } 2656 EXPORT_SYMBOL(vsnprintf); 2657 2658 /** 2659 * vscnprintf - Format a string and place it in a buffer 2660 * @buf: The buffer to place the result into 2661 * @size: The size of the buffer, including the trailing null space 2662 * @fmt: The format string to use 2663 * @args: Arguments for the format string 2664 * 2665 * The return value is the number of characters which have been written into 2666 * the @buf not including the trailing '\0'. If @size is == 0 the function 2667 * returns 0. 2668 * 2669 * If you're not already dealing with a va_list consider using scnprintf(). 2670 * 2671 * See the vsnprintf() documentation for format string extensions over C99. 2672 */ 2673 int vscnprintf(char *buf, size_t size, const char *fmt, va_list args) 2674 { 2675 int i; 2676 2677 i = vsnprintf(buf, size, fmt, args); 2678 2679 if (likely(i < size)) 2680 return i; 2681 if (size != 0) 2682 return size - 1; 2683 return 0; 2684 } 2685 EXPORT_SYMBOL(vscnprintf); 2686 2687 /** 2688 * snprintf - Format a string and place it in a buffer 2689 * @buf: The buffer to place the result into 2690 * @size: The size of the buffer, including the trailing null space 2691 * @fmt: The format string to use 2692 * @...: Arguments for the format string 2693 * 2694 * The return value is the number of characters which would be 2695 * generated for the given input, excluding the trailing null, 2696 * as per ISO C99. If the return is greater than or equal to 2697 * @size, the resulting string is truncated. 2698 * 2699 * See the vsnprintf() documentation for format string extensions over C99. 2700 */ 2701 int snprintf(char *buf, size_t size, const char *fmt, ...) 2702 { 2703 va_list args; 2704 int i; 2705 2706 va_start(args, fmt); 2707 i = vsnprintf(buf, size, fmt, args); 2708 va_end(args); 2709 2710 return i; 2711 } 2712 EXPORT_SYMBOL(snprintf); 2713 2714 /** 2715 * scnprintf - Format a string and place it in a buffer 2716 * @buf: The buffer to place the result into 2717 * @size: The size of the buffer, including the trailing null space 2718 * @fmt: The format string to use 2719 * @...: Arguments for the format string 2720 * 2721 * The return value is the number of characters written into @buf not including 2722 * the trailing '\0'. If @size is == 0 the function returns 0. 2723 */ 2724 2725 int scnprintf(char *buf, size_t size, const char *fmt, ...) 2726 { 2727 va_list args; 2728 int i; 2729 2730 va_start(args, fmt); 2731 i = vscnprintf(buf, size, fmt, args); 2732 va_end(args); 2733 2734 return i; 2735 } 2736 EXPORT_SYMBOL(scnprintf); 2737 2738 /** 2739 * vsprintf - Format a string and place it in a buffer 2740 * @buf: The buffer to place the result into 2741 * @fmt: The format string to use 2742 * @args: Arguments for the format string 2743 * 2744 * The function returns the number of characters written 2745 * into @buf. Use vsnprintf() or vscnprintf() in order to avoid 2746 * buffer overflows. 2747 * 2748 * If you're not already dealing with a va_list consider using sprintf(). 2749 * 2750 * See the vsnprintf() documentation for format string extensions over C99. 2751 */ 2752 int vsprintf(char *buf, const char *fmt, va_list args) 2753 { 2754 return vsnprintf(buf, INT_MAX, fmt, args); 2755 } 2756 EXPORT_SYMBOL(vsprintf); 2757 2758 /** 2759 * sprintf - Format a string and place it in a buffer 2760 * @buf: The buffer to place the result into 2761 * @fmt: The format string to use 2762 * @...: Arguments for the format string 2763 * 2764 * The function returns the number of characters written 2765 * into @buf. Use snprintf() or scnprintf() in order to avoid 2766 * buffer overflows. 2767 * 2768 * See the vsnprintf() documentation for format string extensions over C99. 2769 */ 2770 int sprintf(char *buf, const char *fmt, ...) 2771 { 2772 va_list args; 2773 int i; 2774 2775 va_start(args, fmt); 2776 i = vsnprintf(buf, INT_MAX, fmt, args); 2777 va_end(args); 2778 2779 return i; 2780 } 2781 EXPORT_SYMBOL(sprintf); 2782 2783 #ifdef CONFIG_BINARY_PRINTF 2784 /* 2785 * bprintf service: 2786 * vbin_printf() - VA arguments to binary data 2787 * bstr_printf() - Binary data to text string 2788 */ 2789 2790 /** 2791 * vbin_printf - Parse a format string and place args' binary value in a buffer 2792 * @bin_buf: The buffer to place args' binary value 2793 * @size: The size of the buffer(by words(32bits), not characters) 2794 * @fmt: The format string to use 2795 * @args: Arguments for the format string 2796 * 2797 * The format follows C99 vsnprintf, except %n is ignored, and its argument 2798 * is skipped. 2799 * 2800 * The return value is the number of words(32bits) which would be generated for 2801 * the given input. 2802 * 2803 * NOTE: 2804 * If the return value is greater than @size, the resulting bin_buf is NOT 2805 * valid for bstr_printf(). 2806 */ 2807 int vbin_printf(u32 *bin_buf, size_t size, const char *fmt, va_list args) 2808 { 2809 struct printf_spec spec = {0}; 2810 char *str, *end; 2811 int width; 2812 2813 str = (char *)bin_buf; 2814 end = (char *)(bin_buf + size); 2815 2816 #define save_arg(type) \ 2817 ({ \ 2818 unsigned long long value; \ 2819 if (sizeof(type) == 8) { \ 2820 unsigned long long val8; \ 2821 str = PTR_ALIGN(str, sizeof(u32)); \ 2822 val8 = va_arg(args, unsigned long long); \ 2823 if (str + sizeof(type) <= end) { \ 2824 *(u32 *)str = *(u32 *)&val8; \ 2825 *(u32 *)(str + 4) = *((u32 *)&val8 + 1); \ 2826 } \ 2827 value = val8; \ 2828 } else { \ 2829 unsigned int val4; \ 2830 str = PTR_ALIGN(str, sizeof(type)); \ 2831 val4 = va_arg(args, int); \ 2832 if (str + sizeof(type) <= end) \ 2833 *(typeof(type) *)str = (type)(long)val4; \ 2834 value = (unsigned long long)val4; \ 2835 } \ 2836 str += sizeof(type); \ 2837 value; \ 2838 }) 2839 2840 while (*fmt) { 2841 int read = format_decode(fmt, &spec); 2842 2843 fmt += read; 2844 2845 switch (spec.type) { 2846 case FORMAT_TYPE_NONE: 2847 case FORMAT_TYPE_PERCENT_CHAR: 2848 break; 2849 case FORMAT_TYPE_INVALID: 2850 goto out; 2851 2852 case FORMAT_TYPE_WIDTH: 2853 case FORMAT_TYPE_PRECISION: 2854 width = (int)save_arg(int); 2855 /* Pointers may require the width */ 2856 if (*fmt == 'p') 2857 set_field_width(&spec, width); 2858 break; 2859 2860 case FORMAT_TYPE_CHAR: 2861 save_arg(char); 2862 break; 2863 2864 case FORMAT_TYPE_STR: { 2865 const char *save_str = va_arg(args, char *); 2866 const char *err_msg; 2867 size_t len; 2868 2869 err_msg = check_pointer_msg(save_str); 2870 if (err_msg) 2871 save_str = err_msg; 2872 2873 len = strlen(save_str) + 1; 2874 if (str + len < end) 2875 memcpy(str, save_str, len); 2876 str += len; 2877 break; 2878 } 2879 2880 case FORMAT_TYPE_PTR: 2881 /* Dereferenced pointers must be done now */ 2882 switch (*fmt) { 2883 /* Dereference of functions is still OK */ 2884 case 'S': 2885 case 's': 2886 case 'x': 2887 case 'K': 2888 case 'e': 2889 save_arg(void *); 2890 break; 2891 default: 2892 if (!isalnum(*fmt)) { 2893 save_arg(void *); 2894 break; 2895 } 2896 str = pointer(fmt, str, end, va_arg(args, void *), 2897 spec); 2898 if (str + 1 < end) 2899 *str++ = '\0'; 2900 else 2901 end[-1] = '\0'; /* Must be nul terminated */ 2902 } 2903 /* skip all alphanumeric pointer suffixes */ 2904 while (isalnum(*fmt)) 2905 fmt++; 2906 break; 2907 2908 default: 2909 switch (spec.type) { 2910 2911 case FORMAT_TYPE_LONG_LONG: 2912 save_arg(long long); 2913 break; 2914 case FORMAT_TYPE_ULONG: 2915 case FORMAT_TYPE_LONG: 2916 save_arg(unsigned long); 2917 break; 2918 case FORMAT_TYPE_SIZE_T: 2919 save_arg(size_t); 2920 break; 2921 case FORMAT_TYPE_PTRDIFF: 2922 save_arg(ptrdiff_t); 2923 break; 2924 case FORMAT_TYPE_UBYTE: 2925 case FORMAT_TYPE_BYTE: 2926 save_arg(char); 2927 break; 2928 case FORMAT_TYPE_USHORT: 2929 case FORMAT_TYPE_SHORT: 2930 save_arg(short); 2931 break; 2932 default: 2933 save_arg(int); 2934 } 2935 } 2936 } 2937 2938 out: 2939 return (u32 *)(PTR_ALIGN(str, sizeof(u32))) - bin_buf; 2940 #undef save_arg 2941 } 2942 EXPORT_SYMBOL_GPL(vbin_printf); 2943 2944 /** 2945 * bstr_printf - Format a string from binary arguments and place it in a buffer 2946 * @buf: The buffer to place the result into 2947 * @size: The size of the buffer, including the trailing null space 2948 * @fmt: The format string to use 2949 * @bin_buf: Binary arguments for the format string 2950 * 2951 * This function like C99 vsnprintf, but the difference is that vsnprintf gets 2952 * arguments from stack, and bstr_printf gets arguments from @bin_buf which is 2953 * a binary buffer that generated by vbin_printf. 2954 * 2955 * The format follows C99 vsnprintf, but has some extensions: 2956 * see vsnprintf comment for details. 2957 * 2958 * The return value is the number of characters which would 2959 * be generated for the given input, excluding the trailing 2960 * '\0', as per ISO C99. If you want to have the exact 2961 * number of characters written into @buf as return value 2962 * (not including the trailing '\0'), use vscnprintf(). If the 2963 * return is greater than or equal to @size, the resulting 2964 * string is truncated. 2965 */ 2966 int bstr_printf(char *buf, size_t size, const char *fmt, const u32 *bin_buf) 2967 { 2968 struct printf_spec spec = {0}; 2969 char *str, *end; 2970 const char *args = (const char *)bin_buf; 2971 2972 if (WARN_ON_ONCE(size > INT_MAX)) 2973 return 0; 2974 2975 str = buf; 2976 end = buf + size; 2977 2978 #define get_arg(type) \ 2979 ({ \ 2980 typeof(type) value; \ 2981 if (sizeof(type) == 8) { \ 2982 args = PTR_ALIGN(args, sizeof(u32)); \ 2983 *(u32 *)&value = *(u32 *)args; \ 2984 *((u32 *)&value + 1) = *(u32 *)(args + 4); \ 2985 } else { \ 2986 args = PTR_ALIGN(args, sizeof(type)); \ 2987 value = *(typeof(type) *)args; \ 2988 } \ 2989 args += sizeof(type); \ 2990 value; \ 2991 }) 2992 2993 /* Make sure end is always >= buf */ 2994 if (end < buf) { 2995 end = ((void *)-1); 2996 size = end - buf; 2997 } 2998 2999 while (*fmt) { 3000 const char *old_fmt = fmt; 3001 int read = format_decode(fmt, &spec); 3002 3003 fmt += read; 3004 3005 switch (spec.type) { 3006 case FORMAT_TYPE_NONE: { 3007 int copy = read; 3008 if (str < end) { 3009 if (copy > end - str) 3010 copy = end - str; 3011 memcpy(str, old_fmt, copy); 3012 } 3013 str += read; 3014 break; 3015 } 3016 3017 case FORMAT_TYPE_WIDTH: 3018 set_field_width(&spec, get_arg(int)); 3019 break; 3020 3021 case FORMAT_TYPE_PRECISION: 3022 set_precision(&spec, get_arg(int)); 3023 break; 3024 3025 case FORMAT_TYPE_CHAR: { 3026 char c; 3027 3028 if (!(spec.flags & LEFT)) { 3029 while (--spec.field_width > 0) { 3030 if (str < end) 3031 *str = ' '; 3032 ++str; 3033 } 3034 } 3035 c = (unsigned char) get_arg(char); 3036 if (str < end) 3037 *str = c; 3038 ++str; 3039 while (--spec.field_width > 0) { 3040 if (str < end) 3041 *str = ' '; 3042 ++str; 3043 } 3044 break; 3045 } 3046 3047 case FORMAT_TYPE_STR: { 3048 const char *str_arg = args; 3049 args += strlen(str_arg) + 1; 3050 str = string(str, end, (char *)str_arg, spec); 3051 break; 3052 } 3053 3054 case FORMAT_TYPE_PTR: { 3055 bool process = false; 3056 int copy, len; 3057 /* Non function dereferences were already done */ 3058 switch (*fmt) { 3059 case 'S': 3060 case 's': 3061 case 'F': 3062 case 'f': 3063 case 'x': 3064 case 'K': 3065 case 'e': 3066 process = true; 3067 break; 3068 default: 3069 if (!isalnum(*fmt)) { 3070 process = true; 3071 break; 3072 } 3073 /* Pointer dereference was already processed */ 3074 if (str < end) { 3075 len = copy = strlen(args); 3076 if (copy > end - str) 3077 copy = end - str; 3078 memcpy(str, args, copy); 3079 str += len; 3080 args += len + 1; 3081 } 3082 } 3083 if (process) 3084 str = pointer(fmt, str, end, get_arg(void *), spec); 3085 3086 while (isalnum(*fmt)) 3087 fmt++; 3088 break; 3089 } 3090 3091 case FORMAT_TYPE_PERCENT_CHAR: 3092 if (str < end) 3093 *str = '%'; 3094 ++str; 3095 break; 3096 3097 case FORMAT_TYPE_INVALID: 3098 goto out; 3099 3100 default: { 3101 unsigned long long num; 3102 3103 switch (spec.type) { 3104 3105 case FORMAT_TYPE_LONG_LONG: 3106 num = get_arg(long long); 3107 break; 3108 case FORMAT_TYPE_ULONG: 3109 case FORMAT_TYPE_LONG: 3110 num = get_arg(unsigned long); 3111 break; 3112 case FORMAT_TYPE_SIZE_T: 3113 num = get_arg(size_t); 3114 break; 3115 case FORMAT_TYPE_PTRDIFF: 3116 num = get_arg(ptrdiff_t); 3117 break; 3118 case FORMAT_TYPE_UBYTE: 3119 num = get_arg(unsigned char); 3120 break; 3121 case FORMAT_TYPE_BYTE: 3122 num = get_arg(signed char); 3123 break; 3124 case FORMAT_TYPE_USHORT: 3125 num = get_arg(unsigned short); 3126 break; 3127 case FORMAT_TYPE_SHORT: 3128 num = get_arg(short); 3129 break; 3130 case FORMAT_TYPE_UINT: 3131 num = get_arg(unsigned int); 3132 break; 3133 default: 3134 num = get_arg(int); 3135 } 3136 3137 str = number(str, end, num, spec); 3138 } /* default: */ 3139 } /* switch(spec.type) */ 3140 } /* while(*fmt) */ 3141 3142 out: 3143 if (size > 0) { 3144 if (str < end) 3145 *str = '\0'; 3146 else 3147 end[-1] = '\0'; 3148 } 3149 3150 #undef get_arg 3151 3152 /* the trailing null byte doesn't count towards the total */ 3153 return str - buf; 3154 } 3155 EXPORT_SYMBOL_GPL(bstr_printf); 3156 3157 /** 3158 * bprintf - Parse a format string and place args' binary value in a buffer 3159 * @bin_buf: The buffer to place args' binary value 3160 * @size: The size of the buffer(by words(32bits), not characters) 3161 * @fmt: The format string to use 3162 * @...: Arguments for the format string 3163 * 3164 * The function returns the number of words(u32) written 3165 * into @bin_buf. 3166 */ 3167 int bprintf(u32 *bin_buf, size_t size, const char *fmt, ...) 3168 { 3169 va_list args; 3170 int ret; 3171 3172 va_start(args, fmt); 3173 ret = vbin_printf(bin_buf, size, fmt, args); 3174 va_end(args); 3175 3176 return ret; 3177 } 3178 EXPORT_SYMBOL_GPL(bprintf); 3179 3180 #endif /* CONFIG_BINARY_PRINTF */ 3181 3182 /** 3183 * vsscanf - Unformat a buffer into a list of arguments 3184 * @buf: input buffer 3185 * @fmt: format of buffer 3186 * @args: arguments 3187 */ 3188 int vsscanf(const char *buf, const char *fmt, va_list args) 3189 { 3190 const char *str = buf; 3191 char *next; 3192 char digit; 3193 int num = 0; 3194 u8 qualifier; 3195 unsigned int base; 3196 union { 3197 long long s; 3198 unsigned long long u; 3199 } val; 3200 s16 field_width; 3201 bool is_sign; 3202 3203 while (*fmt) { 3204 /* skip any white space in format */ 3205 /* white space in format matchs any amount of 3206 * white space, including none, in the input. 3207 */ 3208 if (isspace(*fmt)) { 3209 fmt = skip_spaces(++fmt); 3210 str = skip_spaces(str); 3211 } 3212 3213 /* anything that is not a conversion must match exactly */ 3214 if (*fmt != '%' && *fmt) { 3215 if (*fmt++ != *str++) 3216 break; 3217 continue; 3218 } 3219 3220 if (!*fmt) 3221 break; 3222 ++fmt; 3223 3224 /* skip this conversion. 3225 * advance both strings to next white space 3226 */ 3227 if (*fmt == '*') { 3228 if (!*str) 3229 break; 3230 while (!isspace(*fmt) && *fmt != '%' && *fmt) { 3231 /* '%*[' not yet supported, invalid format */ 3232 if (*fmt == '[') 3233 return num; 3234 fmt++; 3235 } 3236 while (!isspace(*str) && *str) 3237 str++; 3238 continue; 3239 } 3240 3241 /* get field width */ 3242 field_width = -1; 3243 if (isdigit(*fmt)) { 3244 field_width = skip_atoi(&fmt); 3245 if (field_width <= 0) 3246 break; 3247 } 3248 3249 /* get conversion qualifier */ 3250 qualifier = -1; 3251 if (*fmt == 'h' || _tolower(*fmt) == 'l' || 3252 *fmt == 'z') { 3253 qualifier = *fmt++; 3254 if (unlikely(qualifier == *fmt)) { 3255 if (qualifier == 'h') { 3256 qualifier = 'H'; 3257 fmt++; 3258 } else if (qualifier == 'l') { 3259 qualifier = 'L'; 3260 fmt++; 3261 } 3262 } 3263 } 3264 3265 if (!*fmt) 3266 break; 3267 3268 if (*fmt == 'n') { 3269 /* return number of characters read so far */ 3270 *va_arg(args, int *) = str - buf; 3271 ++fmt; 3272 continue; 3273 } 3274 3275 if (!*str) 3276 break; 3277 3278 base = 10; 3279 is_sign = false; 3280 3281 switch (*fmt++) { 3282 case 'c': 3283 { 3284 char *s = (char *)va_arg(args, char*); 3285 if (field_width == -1) 3286 field_width = 1; 3287 do { 3288 *s++ = *str++; 3289 } while (--field_width > 0 && *str); 3290 num++; 3291 } 3292 continue; 3293 case 's': 3294 { 3295 char *s = (char *)va_arg(args, char *); 3296 if (field_width == -1) 3297 field_width = SHRT_MAX; 3298 /* first, skip leading white space in buffer */ 3299 str = skip_spaces(str); 3300 3301 /* now copy until next white space */ 3302 while (*str && !isspace(*str) && field_width--) 3303 *s++ = *str++; 3304 *s = '\0'; 3305 num++; 3306 } 3307 continue; 3308 /* 3309 * Warning: This implementation of the '[' conversion specifier 3310 * deviates from its glibc counterpart in the following ways: 3311 * (1) It does NOT support ranges i.e. '-' is NOT a special 3312 * character 3313 * (2) It cannot match the closing bracket ']' itself 3314 * (3) A field width is required 3315 * (4) '%*[' (discard matching input) is currently not supported 3316 * 3317 * Example usage: 3318 * ret = sscanf("00:0a:95","%2[^:]:%2[^:]:%2[^:]", 3319 * buf1, buf2, buf3); 3320 * if (ret < 3) 3321 * // etc.. 3322 */ 3323 case '[': 3324 { 3325 char *s = (char *)va_arg(args, char *); 3326 DECLARE_BITMAP(set, 256) = {0}; 3327 unsigned int len = 0; 3328 bool negate = (*fmt == '^'); 3329 3330 /* field width is required */ 3331 if (field_width == -1) 3332 return num; 3333 3334 if (negate) 3335 ++fmt; 3336 3337 for ( ; *fmt && *fmt != ']'; ++fmt, ++len) 3338 set_bit((u8)*fmt, set); 3339 3340 /* no ']' or no character set found */ 3341 if (!*fmt || !len) 3342 return num; 3343 ++fmt; 3344 3345 if (negate) { 3346 bitmap_complement(set, set, 256); 3347 /* exclude null '\0' byte */ 3348 clear_bit(0, set); 3349 } 3350 3351 /* match must be non-empty */ 3352 if (!test_bit((u8)*str, set)) 3353 return num; 3354 3355 while (test_bit((u8)*str, set) && field_width--) 3356 *s++ = *str++; 3357 *s = '\0'; 3358 ++num; 3359 } 3360 continue; 3361 case 'o': 3362 base = 8; 3363 break; 3364 case 'x': 3365 case 'X': 3366 base = 16; 3367 break; 3368 case 'i': 3369 base = 0; 3370 /* fall through */ 3371 case 'd': 3372 is_sign = true; 3373 /* fall through */ 3374 case 'u': 3375 break; 3376 case '%': 3377 /* looking for '%' in str */ 3378 if (*str++ != '%') 3379 return num; 3380 continue; 3381 default: 3382 /* invalid format; stop here */ 3383 return num; 3384 } 3385 3386 /* have some sort of integer conversion. 3387 * first, skip white space in buffer. 3388 */ 3389 str = skip_spaces(str); 3390 3391 digit = *str; 3392 if (is_sign && digit == '-') 3393 digit = *(str + 1); 3394 3395 if (!digit 3396 || (base == 16 && !isxdigit(digit)) 3397 || (base == 10 && !isdigit(digit)) 3398 || (base == 8 && (!isdigit(digit) || digit > '7')) 3399 || (base == 0 && !isdigit(digit))) 3400 break; 3401 3402 if (is_sign) 3403 val.s = qualifier != 'L' ? 3404 simple_strtol(str, &next, base) : 3405 simple_strtoll(str, &next, base); 3406 else 3407 val.u = qualifier != 'L' ? 3408 simple_strtoul(str, &next, base) : 3409 simple_strtoull(str, &next, base); 3410 3411 if (field_width > 0 && next - str > field_width) { 3412 if (base == 0) 3413 _parse_integer_fixup_radix(str, &base); 3414 while (next - str > field_width) { 3415 if (is_sign) 3416 val.s = div_s64(val.s, base); 3417 else 3418 val.u = div_u64(val.u, base); 3419 --next; 3420 } 3421 } 3422 3423 switch (qualifier) { 3424 case 'H': /* that's 'hh' in format */ 3425 if (is_sign) 3426 *va_arg(args, signed char *) = val.s; 3427 else 3428 *va_arg(args, unsigned char *) = val.u; 3429 break; 3430 case 'h': 3431 if (is_sign) 3432 *va_arg(args, short *) = val.s; 3433 else 3434 *va_arg(args, unsigned short *) = val.u; 3435 break; 3436 case 'l': 3437 if (is_sign) 3438 *va_arg(args, long *) = val.s; 3439 else 3440 *va_arg(args, unsigned long *) = val.u; 3441 break; 3442 case 'L': 3443 if (is_sign) 3444 *va_arg(args, long long *) = val.s; 3445 else 3446 *va_arg(args, unsigned long long *) = val.u; 3447 break; 3448 case 'z': 3449 *va_arg(args, size_t *) = val.u; 3450 break; 3451 default: 3452 if (is_sign) 3453 *va_arg(args, int *) = val.s; 3454 else 3455 *va_arg(args, unsigned int *) = val.u; 3456 break; 3457 } 3458 num++; 3459 3460 if (!next) 3461 break; 3462 str = next; 3463 } 3464 3465 return num; 3466 } 3467 EXPORT_SYMBOL(vsscanf); 3468 3469 /** 3470 * sscanf - Unformat a buffer into a list of arguments 3471 * @buf: input buffer 3472 * @fmt: formatting of buffer 3473 * @...: resulting arguments 3474 */ 3475 int sscanf(const char *buf, const char *fmt, ...) 3476 { 3477 va_list args; 3478 int i; 3479 3480 va_start(args, fmt); 3481 i = vsscanf(buf, fmt, args); 3482 va_end(args); 3483 3484 return i; 3485 } 3486 EXPORT_SYMBOL(sscanf); 3487