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pointer to the end of the parsed string will be placed here 54 * @base: The number base to use 55 * 56 * This function is obsolete.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pointer to the end of the parsed string will be placed here 79 * @base: The number base to use 80 * 81 * This function is obsolete.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