lib/vsprintf.c

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  59  * This function is obsolete.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

DEFINITIONS
