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1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * linux/lib/vsprintf.c
4 *
5 * Copyright (C) 1991, 1992 Linus Torvalds
6 */
7
8 /* vsprintf.c -- Lars Wirzenius & Linus Torvalds. */
9 /*
10 * Wirzenius wrote this portably, Torvalds fucked it up :-)
11 */
12
13 /*
14 * Fri Jul 13 2001 Crutcher Dunnavant <crutcher+kernel@datastacks.com>
15 * - changed to provide snprintf and vsnprintf functions
16 * So Feb 1 16:51:32 CET 2004 Juergen Quade <quade@hsnr.de>
17 * - scnprintf and vscnprintf
18 */
19
20 #include <stdarg.h>
21 #include <linux/build_bug.h>
22 #include <linux/clk.h>
23 #include <linux/clk-provider.h>
24 #include <linux/errname.h>
25 #include <linux/module.h> /* for KSYM_SYMBOL_LEN */
26 #include <linux/types.h>
27 #include <linux/string.h>
28 #include <linux/ctype.h>
29 #include <linux/kernel.h>
30 #include <linux/kallsyms.h>
31 #include <linux/math64.h>
32 #include <linux/uaccess.h>
33 #include <linux/ioport.h>
34 #include <linux/dcache.h>
35 #include <linux/cred.h>
36 #include <linux/rtc.h>
37 #include <linux/time.h>
38 #include <linux/uuid.h>
39 #include <linux/of.h>
40 #include <net/addrconf.h>
41 #include <linux/siphash.h>
42 #include <linux/compiler.h>
43 #include <linux/property.h>
44 #ifdef CONFIG_BLOCK
45 #include <linux/blkdev.h>
46 #endif
47
48 #include "../mm/internal.h" /* For the trace_print_flags arrays */
49
50 #include <asm/page.h> /* for PAGE_SIZE */
51 #include <asm/byteorder.h> /* cpu_to_le16 */
52
53 #include <linux/string_helpers.h>
54 #include "kstrtox.h"
55
56 /**
57 * simple_strtoull - convert a string to an unsigned long long
58 * @cp: The start of the string
59 * @endp: A pointer to the end of the parsed string will be placed here
60 * @base: The number base to use
61 *
62 * This function has caveats. Please use kstrtoull instead.
63 */
64 unsigned long long simple_strtoull(const char *cp, char **endp, unsigned int base)
65 {
66 unsigned long long result;
67 unsigned int rv;
68
69 cp = _parse_integer_fixup_radix(cp, &base);
70 rv = _parse_integer(cp, base, &result);
71 /* FIXME */
72 cp += (rv & ~KSTRTOX_OVERFLOW);
73
74 if (endp)
75 *endp = (char *)cp;
76
77 return result;
78 }
79 EXPORT_SYMBOL(simple_strtoull);
80
81 /**
82 * simple_strtoul - convert a string to an unsigned long
83 * @cp: The start of the string
84 * @endp: A pointer to the end of the parsed string will be placed here
85 * @base: The number base to use
86 *
87 * This function has caveats. Please use kstrtoul instead.
88 */
89 unsigned long simple_strtoul(const char *cp, char **endp, unsigned int base)
90 {
91 return simple_strtoull(cp, endp, base);
92 }
93 EXPORT_SYMBOL(simple_strtoul);
94
95 /**
96 * simple_strtol - convert a string to a signed long
97 * @cp: The start of the string
98 * @endp: A pointer to the end of the parsed string will be placed here
99 * @base: The number base to use
100 *
101 * This function has caveats. Please use kstrtol instead.
102 */
103 long simple_strtol(const char *cp, char **endp, unsigned int base)
104 {
105 if (*cp == '-')
106 return -simple_strtoul(cp + 1, endp, base);
107
108 return simple_strtoul(cp, endp, base);
109 }
110 EXPORT_SYMBOL(simple_strtol);
111
112 /**
113 * simple_strtoll - convert a string to a signed long long
114 * @cp: The start of the string
115 * @endp: A pointer to the end of the parsed string will be placed here
116 * @base: The number base to use
117 *
118 * This function has caveats. Please use kstrtoll instead.
119 */
120 long long simple_strtoll(const char *cp, char **endp, unsigned int base)
121 {
122 if (*cp == '-')
123 return -simple_strtoull(cp + 1, endp, base);
124
125 return simple_strtoull(cp, endp, base);
126 }
127 EXPORT_SYMBOL(simple_strtoll);
128
129 static noinline_for_stack
130 int skip_atoi(const char **s)
131 {
132 int i = 0;
133
134 do {
135 i = i*10 + *((*s)++) - '0';
136 } while (isdigit(**s));
137
138 return i;
139 }
140
141 /*
142 * Decimal conversion is by far the most typical, and is used for
143 * /proc and /sys data. This directly impacts e.g. top performance
144 * with many processes running. We optimize it for speed by emitting
145 * two characters at a time, using a 200 byte lookup table. This
146 * roughly halves the number of multiplications compared to computing
147 * the digits one at a time. Implementation strongly inspired by the
148 * previous version, which in turn used ideas described at
149 * <http://www.cs.uiowa.edu/~jones/bcd/divide.html> (with permission
150 * from the author, Douglas W. Jones).
151 *
152 * It turns out there is precisely one 26 bit fixed-point
153 * approximation a of 64/100 for which x/100 == (x * (u64)a) >> 32
154 * holds for all x in [0, 10^8-1], namely a = 0x28f5c29. The actual
155 * range happens to be somewhat larger (x <= 1073741898), but that's
156 * irrelevant for our purpose.
157 *
158 * For dividing a number in the range [10^4, 10^6-1] by 100, we still
159 * need a 32x32->64 bit multiply, so we simply use the same constant.
160 *
161 * For dividing a number in the range [100, 10^4-1] by 100, there are
162 * several options. The simplest is (x * 0x147b) >> 19, which is valid
163 * for all x <= 43698.
164 */
165
166 static const u16 decpair[100] = {
167 #define _(x) (__force u16) cpu_to_le16(((x % 10) | ((x / 10) << 8)) + 0x3030)
168 _( 0), _( 1), _( 2), _( 3), _( 4), _( 5), _( 6), _( 7), _( 8), _( 9),
169 _(10), _(11), _(12), _(13), _(14), _(15), _(16), _(17), _(18), _(19),
170 _(20), _(21), _(22), _(23), _(24), _(25), _(26), _(27), _(28), _(29),
171 _(30), _(31), _(32), _(33), _(34), _(35), _(36), _(37), _(38), _(39),
172 _(40), _(41), _(42), _(43), _(44), _(45), _(46), _(47), _(48), _(49),
173 _(50), _(51), _(52), _(53), _(54), _(55), _(56), _(57), _(58), _(59),
174 _(60), _(61), _(62), _(63), _(64), _(65), _(66), _(67), _(68), _(69),
175 _(70), _(71), _(72), _(73), _(74), _(75), _(76), _(77), _(78), _(79),
176 _(80), _(81), _(82), _(83), _(84), _(85), _(86), _(87), _(88), _(89),
177 _(90), _(91), _(92), _(93), _(94), _(95), _(96), _(97), _(98), _(99),
178 #undef _
179 };
180
181 /*
182 * This will print a single '0' even if r == 0, since we would
183 * immediately jump to out_r where two 0s would be written but only
184 * one of them accounted for in buf. This is needed by ip4_string
185 * below. All other callers pass a non-zero value of r.
186 */
187 static noinline_for_stack
188 char *put_dec_trunc8(char *buf, unsigned r)
189 {
190 unsigned q;
191
192 /* 1 <= r < 10^8 */
193 if (r < 100)
194 goto out_r;
195
196 /* 100 <= r < 10^8 */
197 q = (r * (u64)0x28f5c29) >> 32;
198 *((u16 *)buf) = decpair[r - 100*q];
199 buf += 2;
200
201 /* 1 <= q < 10^6 */
202 if (q < 100)
203 goto out_q;
204
205 /* 100 <= q < 10^6 */
206 r = (q * (u64)0x28f5c29) >> 32;
207 *((u16 *)buf) = decpair[q - 100*r];
208 buf += 2;
209
210 /* 1 <= r < 10^4 */
211 if (r < 100)
212 goto out_r;
213
214 /* 100 <= r < 10^4 */
215 q = (r * 0x147b) >> 19;
216 *((u16 *)buf) = decpair[r - 100*q];
217 buf += 2;
218 out_q:
219 /* 1 <= q < 100 */
220 r = q;
221 out_r:
222 /* 1 <= r < 100 */
223 *((u16 *)buf) = decpair[r];
224 buf += r < 10 ? 1 : 2;
225 return buf;
226 }
227
228 #if BITS_PER_LONG == 64 && BITS_PER_LONG_LONG == 64
229 static noinline_for_stack
230 char *put_dec_full8(char *buf, unsigned r)
231 {
232 unsigned q;
233
234 /* 0 <= r < 10^8 */
235 q = (r * (u64)0x28f5c29) >> 32;
236 *((u16 *)buf) = decpair[r - 100*q];
237 buf += 2;
238
239 /* 0 <= q < 10^6 */
240 r = (q * (u64)0x28f5c29) >> 32;
241 *((u16 *)buf) = decpair[q - 100*r];
242 buf += 2;
243
244 /* 0 <= r < 10^4 */
245 q = (r * 0x147b) >> 19;
246 *((u16 *)buf) = decpair[r - 100*q];
247 buf += 2;
248
249 /* 0 <= q < 100 */
250 *((u16 *)buf) = decpair[q];
251 buf += 2;
252 return buf;
253 }
254
255 static noinline_for_stack
256 char *put_dec(char *buf, unsigned long long n)
257 {
258 if (n >= 100*1000*1000)
259 buf = put_dec_full8(buf, do_div(n, 100*1000*1000));
260 /* 1 <= n <= 1.6e11 */
261 if (n >= 100*1000*1000)
262 buf = put_dec_full8(buf, do_div(n, 100*1000*1000));
263 /* 1 <= n < 1e8 */
264 return put_dec_trunc8(buf, n);
265 }
266
267 #elif BITS_PER_LONG == 32 && BITS_PER_LONG_LONG == 64
268
269 static void
270 put_dec_full4(char *buf, unsigned r)
271 {
272 unsigned q;
273
274 /* 0 <= r < 10^4 */
275 q = (r * 0x147b) >> 19;
276 *((u16 *)buf) = decpair[r - 100*q];
277 buf += 2;
278 /* 0 <= q < 100 */
279 *((u16 *)buf) = decpair[q];
280 }
281
282 /*
283 * Call put_dec_full4 on x % 10000, return x / 10000.
284 * The approximation x/10000 == (x * 0x346DC5D7) >> 43
285 * holds for all x < 1,128,869,999. The largest value this
286 * helper will ever be asked to convert is 1,125,520,955.
287 * (second call in the put_dec code, assuming n is all-ones).
288 */
289 static noinline_for_stack
290 unsigned put_dec_helper4(char *buf, unsigned x)
291 {
292 uint32_t q = (x * (uint64_t)0x346DC5D7) >> 43;
293
294 put_dec_full4(buf, x - q * 10000);
295 return q;
296 }
297
298 /* Based on code by Douglas W. Jones found at
299 * <http://www.cs.uiowa.edu/~jones/bcd/decimal.html#sixtyfour>
300 * (with permission from the author).
301 * Performs no 64-bit division and hence should be fast on 32-bit machines.
302 */
303 static
304 char *put_dec(char *buf, unsigned long long n)
305 {
306 uint32_t d3, d2, d1, q, h;
307
308 if (n < 100*1000*1000)
309 return put_dec_trunc8(buf, n);
310
311 d1 = ((uint32_t)n >> 16); /* implicit "& 0xffff" */
312 h = (n >> 32);
313 d2 = (h ) & 0xffff;
314 d3 = (h >> 16); /* implicit "& 0xffff" */
315
316 /* n = 2^48 d3 + 2^32 d2 + 2^16 d1 + d0
317 = 281_4749_7671_0656 d3 + 42_9496_7296 d2 + 6_5536 d1 + d0 */
318 q = 656 * d3 + 7296 * d2 + 5536 * d1 + ((uint32_t)n & 0xffff);
319 q = put_dec_helper4(buf, q);
320
321 q += 7671 * d3 + 9496 * d2 + 6 * d1;
322 q = put_dec_helper4(buf+4, q);
323
324 q += 4749 * d3 + 42 * d2;
325 q = put_dec_helper4(buf+8, q);
326
327 q += 281 * d3;
328 buf += 12;
329 if (q)
330 buf = put_dec_trunc8(buf, q);
331 else while (buf[-1] == '0')
332 --buf;
333
334 return buf;
335 }
336
337 #endif
338
339 /*
340 * Convert passed number to decimal string.
341 * Returns the length of string. On buffer overflow, returns 0.
342 *
343 * If speed is not important, use snprintf(). It's easy to read the code.
344 */
345 int num_to_str(char *buf, int size, unsigned long long num, unsigned int width)
346 {
347 /* put_dec requires 2-byte alignment of the buffer. */
348 char tmp[sizeof(num) * 3] __aligned(2);
349 int idx, len;
350
351 /* put_dec() may work incorrectly for num = 0 (generate "", not "0") */
352 if (num <= 9) {
353 tmp[0] = '0' + num;
354 len = 1;
355 } else {
356 len = put_dec(tmp, num) - tmp;
357 }
358
359 if (len > size || width > size)
360 return 0;
361
362 if (width > len) {
363 width = width - len;
364 for (idx = 0; idx < width; idx++)
365 buf[idx] = ' ';
366 } else {
367 width = 0;
368 }
369
370 for (idx = 0; idx < len; ++idx)
371 buf[idx + width] = tmp[len - idx - 1];
372
373 return len + width;
374 }
375
376 #define SIGN 1 /* unsigned/signed, must be 1 */
377 #define LEFT 2 /* left justified */
378 #define PLUS 4 /* show plus */
379 #define SPACE 8 /* space if plus */
380 #define ZEROPAD 16 /* pad with zero, must be 16 == '0' - ' ' */
381 #define SMALL 32 /* use lowercase in hex (must be 32 == 0x20) */
382 #define SPECIAL 64 /* prefix hex with "0x", octal with "0" */
383
384 static_assert(ZEROPAD == ('0' - ' '));
385 static_assert(SMALL == ' ');
386
387 enum format_type {
388 FORMAT_TYPE_NONE, /* Just a string part */
389 FORMAT_TYPE_WIDTH,
390 FORMAT_TYPE_PRECISION,
391 FORMAT_TYPE_CHAR,
392 FORMAT_TYPE_STR,
393 FORMAT_TYPE_PTR,
394 FORMAT_TYPE_PERCENT_CHAR,
395 FORMAT_TYPE_INVALID,
396 FORMAT_TYPE_LONG_LONG,
397 FORMAT_TYPE_ULONG,
398 FORMAT_TYPE_LONG,
399 FORMAT_TYPE_UBYTE,
400 FORMAT_TYPE_BYTE,
401 FORMAT_TYPE_USHORT,
402 FORMAT_TYPE_SHORT,
403 FORMAT_TYPE_UINT,
404 FORMAT_TYPE_INT,
405 FORMAT_TYPE_SIZE_T,
406 FORMAT_TYPE_PTRDIFF
407 };
408
409 struct printf_spec {
410 unsigned int type:8; /* format_type enum */
411 signed int field_width:24; /* width of output field */
412 unsigned int flags:8; /* flags to number() */
413 unsigned int base:8; /* number base, 8, 10 or 16 only */
414 signed int precision:16; /* # of digits/chars */
415 } __packed;
416 static_assert(sizeof(struct printf_spec) == 8);
417
418 #define FIELD_WIDTH_MAX ((1 << 23) - 1)
419 #define PRECISION_MAX ((1 << 15) - 1)
420
421 static noinline_for_stack
422 char *number(char *buf, char *end, unsigned long long num,
423 struct printf_spec spec)
424 {
425 /* put_dec requires 2-byte alignment of the buffer. */
426 char tmp[3 * sizeof(num)] __aligned(2);
427 char sign;
428 char locase;
429 int need_pfx = ((spec.flags & SPECIAL) && spec.base != 10);
430 int i;
431 bool is_zero = num == 0LL;
432 int field_width = spec.field_width;
433 int precision = spec.precision;
434
435 /* locase = 0 or 0x20. ORing digits or letters with 'locase'
436 * produces same digits or (maybe lowercased) letters */
437 locase = (spec.flags & SMALL);
438 if (spec.flags & LEFT)
439 spec.flags &= ~ZEROPAD;
440 sign = 0;
441 if (spec.flags & SIGN) {
442 if ((signed long long)num < 0) {
443 sign = '-';
444 num = -(signed long long)num;
445 field_width--;
446 } else if (spec.flags & PLUS) {
447 sign = '+';
448 field_width--;
449 } else if (spec.flags & SPACE) {
450 sign = ' ';
451 field_width--;
452 }
453 }
454 if (need_pfx) {
455 if (spec.base == 16)
456 field_width -= 2;
457 else if (!is_zero)
458 field_width--;
459 }
460
461 /* generate full string in tmp[], in reverse order */
462 i = 0;
463 if (num < spec.base)
464 tmp[i++] = hex_asc_upper[num] | locase;
465 else if (spec.base != 10) { /* 8 or 16 */
466 int mask = spec.base - 1;
467 int shift = 3;
468
469 if (spec.base == 16)
470 shift = 4;
471 do {
472 tmp[i++] = (hex_asc_upper[((unsigned char)num) & mask] | locase);
473 num >>= shift;
474 } while (num);
475 } else { /* base 10 */
476 i = put_dec(tmp, num) - tmp;
477 }
478
479 /* printing 100 using %2d gives "100", not "00" */
480 if (i > precision)
481 precision = i;
482 /* leading space padding */
483 field_width -= precision;
484 if (!(spec.flags & (ZEROPAD | LEFT))) {
485 while (--field_width >= 0) {
486 if (buf < end)
487 *buf = ' ';
488 ++buf;
489 }
490 }
491 /* sign */
492 if (sign) {
493 if (buf < end)
494 *buf = sign;
495 ++buf;
496 }
497 /* "0x" / "0" prefix */
498 if (need_pfx) {
499 if (spec.base == 16 || !is_zero) {
500 if (buf < end)
501 *buf = '0';
502 ++buf;
503 }
504 if (spec.base == 16) {
505 if (buf < end)
506 *buf = ('X' | locase);
507 ++buf;
508 }
509 }
510 /* zero or space padding */
511 if (!(spec.flags & LEFT)) {
512 char c = ' ' + (spec.flags & ZEROPAD);
513
514 while (--field_width >= 0) {
515 if (buf < end)
516 *buf = c;
517 ++buf;
518 }
519 }
520 /* hmm even more zero padding? */
521 while (i <= --precision) {
522 if (buf < end)
523 *buf = '0';
524 ++buf;
525 }
526 /* actual digits of result */
527 while (--i >= 0) {
528 if (buf < end)
529 *buf = tmp[i];
530 ++buf;
531 }
532 /* trailing space padding */
533 while (--field_width >= 0) {
534 if (buf < end)
535 *buf = ' ';
536 ++buf;
537 }
538
539 return buf;
540 }
541
542 static noinline_for_stack
543 char *special_hex_number(char *buf, char *end, unsigned long long num, int size)
544 {
545 struct printf_spec spec;
546
547 spec.type = FORMAT_TYPE_PTR;
548 spec.field_width = 2 + 2 * size; /* 0x + hex */
549 spec.flags = SPECIAL | SMALL | ZEROPAD;
550 spec.base = 16;
551 spec.precision = -1;
552
553 return number(buf, end, num, spec);
554 }
555
556 static void move_right(char *buf, char *end, unsigned len, unsigned spaces)
557 {
558 size_t size;
559 if (buf >= end) /* nowhere to put anything */
560 return;
561 size = end - buf;
562 if (size <= spaces) {
563 memset(buf, ' ', size);
564 return;
565 }
566 if (len) {
567 if (len > size - spaces)
568 len = size - spaces;
569 memmove(buf + spaces, buf, len);
570 }
571 memset(buf, ' ', spaces);
572 }
573
574 /*
575 * Handle field width padding for a string.
576 * @buf: current buffer position
577 * @n: length of string
578 * @end: end of output buffer
579 * @spec: for field width and flags
580 * Returns: new buffer position after padding.
581 */
582 static noinline_for_stack
583 char *widen_string(char *buf, int n, char *end, struct printf_spec spec)
584 {
585 unsigned spaces;
586
587 if (likely(n >= spec.field_width))
588 return buf;
589 /* we want to pad the sucker */
590 spaces = spec.field_width - n;
591 if (!(spec.flags & LEFT)) {
592 move_right(buf - n, end, n, spaces);
593 return buf + spaces;
594 }
595 while (spaces--) {
596 if (buf < end)
597 *buf = ' ';
598 ++buf;
599 }
600 return buf;
601 }
602
603 /* Handle string from a well known address. */
604 static char *string_nocheck(char *buf, char *end, const char *s,
605 struct printf_spec spec)
606 {
607 int len = 0;
608 int lim = spec.precision;
609
610 while (lim--) {
611 char c = *s++;
612 if (!c)
613 break;
614 if (buf < end)
615 *buf = c;
616 ++buf;
617 ++len;
618 }
619 return widen_string(buf, len, end, spec);
620 }
621
622 static char *err_ptr(char *buf, char *end, void *ptr,
623 struct printf_spec spec)
624 {
625 int err = PTR_ERR(ptr);
626 const char *sym = errname(err);
627
628 if (sym)
629 return string_nocheck(buf, end, sym, spec);
630
631 /*
632 * Somebody passed ERR_PTR(-1234) or some other non-existing
633 * Efoo - or perhaps CONFIG_SYMBOLIC_ERRNAME=n. Fall back to
634 * printing it as its decimal representation.
635 */
636 spec.flags |= SIGN;
637 spec.base = 10;
638 return number(buf, end, err, spec);
639 }
640
641 /* Be careful: error messages must fit into the given buffer. */
642 static char *error_string(char *buf, char *end, const char *s,
643 struct printf_spec spec)
644 {
645 /*
646 * Hard limit to avoid a completely insane messages. It actually
647 * works pretty well because most error messages are in
648 * the many pointer format modifiers.
649 */
650 if (spec.precision == -1)
651 spec.precision = 2 * sizeof(void *);
652
653 return string_nocheck(buf, end, s, spec);
654 }
655
656 /*
657 * Do not call any complex external code here. Nested printk()/vsprintf()
658 * might cause infinite loops. Failures might break printk() and would
659 * be hard to debug.
660 */
661 static const char *check_pointer_msg(const void *ptr)
662 {
663 if (!ptr)
664 return "(null)";
665
666 if ((unsigned long)ptr < PAGE_SIZE || IS_ERR_VALUE(ptr))
667 return "(efault)";
668
669 return NULL;
670 }
671
672 static int check_pointer(char **buf, char *end, const void *ptr,
673 struct printf_spec spec)
674 {
675 const char *err_msg;
676
677 err_msg = check_pointer_msg(ptr);
678 if (err_msg) {
679 *buf = error_string(*buf, end, err_msg, spec);
680 return -EFAULT;
681 }
682
683 return 0;
684 }
685
686 static noinline_for_stack
687 char *string(char *buf, char *end, const char *s,
688 struct printf_spec spec)
689 {
690 if (check_pointer(&buf, end, s, spec))
691 return buf;
692
693 return string_nocheck(buf, end, s, spec);
694 }
695
696 static char *pointer_string(char *buf, char *end,
697 const void *ptr,
698 struct printf_spec spec)
699 {
700 spec.base = 16;
701 spec.flags |= SMALL;
702 if (spec.field_width == -1) {
703 spec.field_width = 2 * sizeof(ptr);
704 spec.flags |= ZEROPAD;
705 }
706
707 return number(buf, end, (unsigned long int)ptr, spec);
708 }
709
710 /* Make pointers available for printing early in the boot sequence. */
711 static int debug_boot_weak_hash __ro_after_init;
712
713 static int __init debug_boot_weak_hash_enable(char *str)
714 {
715 debug_boot_weak_hash = 1;
716 pr_info("debug_boot_weak_hash enabled\n");
717 return 0;
718 }
719 early_param("debug_boot_weak_hash", debug_boot_weak_hash_enable);
720
721 static DEFINE_STATIC_KEY_TRUE(not_filled_random_ptr_key);
722 static siphash_key_t ptr_key __read_mostly;
723
724 static void enable_ptr_key_workfn(struct work_struct *work)
725 {
726 get_random_bytes(&ptr_key, sizeof(ptr_key));
727 /* Needs to run from preemptible context */
728 static_branch_disable(&not_filled_random_ptr_key);
729 }
730
731 static DECLARE_WORK(enable_ptr_key_work, enable_ptr_key_workfn);
732
733 static void fill_random_ptr_key(struct random_ready_callback *unused)
734 {
735 /* This may be in an interrupt handler. */
736 queue_work(system_unbound_wq, &enable_ptr_key_work);
737 }
738
739 static struct random_ready_callback random_ready = {
740 .func = fill_random_ptr_key
741 };
742
743 static int __init initialize_ptr_random(void)
744 {
745 int key_size = sizeof(ptr_key);
746 int ret;
747
748 /* Use hw RNG if available. */
749 if (get_random_bytes_arch(&ptr_key, key_size) == key_size) {
750 static_branch_disable(&not_filled_random_ptr_key);
751 return 0;
752 }
753
754 ret = add_random_ready_callback(&random_ready);
755 if (!ret) {
756 return 0;
757 } else if (ret == -EALREADY) {
758 /* This is in preemptible context */
759 enable_ptr_key_workfn(&enable_ptr_key_work);
760 return 0;
761 }
762
763 return ret;
764 }
765 early_initcall(initialize_ptr_random);
766
767 /* Maps a pointer to a 32 bit unique identifier. */
768 static inline int __ptr_to_hashval(const void *ptr, unsigned long *hashval_out)
769 {
770 unsigned long hashval;
771
772 if (static_branch_unlikely(&not_filled_random_ptr_key))
773 return -EAGAIN;
774
775 #ifdef CONFIG_64BIT
776 hashval = (unsigned long)siphash_1u64((u64)ptr, &ptr_key);
777 /*
778 * Mask off the first 32 bits, this makes explicit that we have
779 * modified the address (and 32 bits is plenty for a unique ID).
780 */
781 hashval = hashval & 0xffffffff;
782 #else
783 hashval = (unsigned long)siphash_1u32((u32)ptr, &ptr_key);
784 #endif
785 *hashval_out = hashval;
786 return 0;
787 }
788
789 int ptr_to_hashval(const void *ptr, unsigned long *hashval_out)
790 {
791 return __ptr_to_hashval(ptr, hashval_out);
792 }
793
794 static char *ptr_to_id(char *buf, char *end, const void *ptr,
795 struct printf_spec spec)
796 {
797 const char *str = sizeof(ptr) == 8 ? "(____ptrval____)" : "(ptrval)";
798 unsigned long hashval;
799 int ret;
800
801 /*
802 * Print the real pointer value for NULL and error pointers,
803 * as they are not actual addresses.
804 */
805 if (IS_ERR_OR_NULL(ptr))
806 return pointer_string(buf, end, ptr, spec);
807
808 /* When debugging early boot use non-cryptographically secure hash. */
809 if (unlikely(debug_boot_weak_hash)) {
810 hashval = hash_long((unsigned long)ptr, 32);
811 return pointer_string(buf, end, (const void *)hashval, spec);
812 }
813
814 ret = __ptr_to_hashval(ptr, &hashval);
815 if (ret) {
816 spec.field_width = 2 * sizeof(ptr);
817 /* string length must be less than default_width */
818 return error_string(buf, end, str, spec);
819 }
820
821 return pointer_string(buf, end, (const void *)hashval, spec);
822 }
823
824 int kptr_restrict __read_mostly;
825
826 static noinline_for_stack
827 char *restricted_pointer(char *buf, char *end, const void *ptr,
828 struct printf_spec spec)
829 {
830 switch (kptr_restrict) {
831 case 0:
832 /* Handle as %p, hash and do _not_ leak addresses. */
833 return ptr_to_id(buf, end, ptr, spec);
834 case 1: {
835 const struct cred *cred;
836
837 /*
838 * kptr_restrict==1 cannot be used in IRQ context
839 * because its test for CAP_SYSLOG would be meaningless.
840 */
841 if (in_irq() || in_serving_softirq() || in_nmi()) {
842 if (spec.field_width == -1)
843 spec.field_width = 2 * sizeof(ptr);
844 return error_string(buf, end, "pK-error", spec);
845 }
846
847 /*
848 * Only print the real pointer value if the current
849 * process has CAP_SYSLOG and is running with the
850 * same credentials it started with. This is because
851 * access to files is checked at open() time, but %pK
852 * checks permission at read() time. We don't want to
853 * leak pointer values if a binary opens a file using
854 * %pK and then elevates privileges before reading it.
855 */
856 cred = current_cred();
857 if (!has_capability_noaudit(current, CAP_SYSLOG) ||
858 !uid_eq(cred->euid, cred->uid) ||
859 !gid_eq(cred->egid, cred->gid))
860 ptr = NULL;
861 break;
862 }
863 case 2:
864 default:
865 /* Always print 0's for %pK */
866 ptr = NULL;
867 break;
868 }
869
870 return pointer_string(buf, end, ptr, spec);
871 }
872
873 static noinline_for_stack
874 char *dentry_name(char *buf, char *end, const struct dentry *d, struct printf_spec spec,
875 const char *fmt)
876 {
877 const char *array[4], *s;
878 const struct dentry *p;
879 int depth;
880 int i, n;
881
882 switch (fmt[1]) {
883 case '2': case '3': case '4':
884 depth = fmt[1] - '0';
885 break;
886 default:
887 depth = 1;
888 }
889
890 rcu_read_lock();
891 for (i = 0; i < depth; i++, d = p) {
892 if (check_pointer(&buf, end, d, spec)) {
893 rcu_read_unlock();
894 return buf;
895 }
896
897 p = READ_ONCE(d->d_parent);
898 array[i] = READ_ONCE(d->d_name.name);
899 if (p == d) {
900 if (i)
901 array[i] = "";
902 i++;
903 break;
904 }
905 }
906 s = array[--i];
907 for (n = 0; n != spec.precision; n++, buf++) {
908 char c = *s++;
909 if (!c) {
910 if (!i)
911 break;
912 c = '/';
913 s = array[--i];
914 }
915 if (buf < end)
916 *buf = c;
917 }
918 rcu_read_unlock();
919 return widen_string(buf, n, end, spec);
920 }
921
922 static noinline_for_stack
923 char *file_dentry_name(char *buf, char *end, const struct file *f,
924 struct printf_spec spec, const char *fmt)
925 {
926 if (check_pointer(&buf, end, f, spec))
927 return buf;
928
929 return dentry_name(buf, end, f->f_path.dentry, spec, fmt);
930 }
931 #ifdef CONFIG_BLOCK
932 static noinline_for_stack
933 char *bdev_name(char *buf, char *end, struct block_device *bdev,
934 struct printf_spec spec, const char *fmt)
935 {
936 struct gendisk *hd;
937
938 if (check_pointer(&buf, end, bdev, spec))
939 return buf;
940
941 hd = bdev->bd_disk;
942 buf = string(buf, end, hd->disk_name, spec);
943 if (bdev->bd_partno) {
944 if (isdigit(hd->disk_name[strlen(hd->disk_name)-1])) {
945 if (buf < end)
946 *buf = 'p';
947 buf++;
948 }
949 buf = number(buf, end, bdev->bd_partno, spec);
950 }
951 return buf;
952 }
953 #endif
954
955 static noinline_for_stack
956 char *symbol_string(char *buf, char *end, void *ptr,
957 struct printf_spec spec, const char *fmt)
958 {
959 unsigned long value;
960 #ifdef CONFIG_KALLSYMS
961 char sym[KSYM_SYMBOL_LEN];
962 #endif
963
964 if (fmt[1] == 'R')
965 ptr = __builtin_extract_return_addr(ptr);
966 value = (unsigned long)ptr;
967
968 #ifdef CONFIG_KALLSYMS
969 if (*fmt == 'B')
970 sprint_backtrace(sym, value);
971 else if (*fmt != 's')
972 sprint_symbol(sym, value);
973 else
974 sprint_symbol_no_offset(sym, value);
975
976 return string_nocheck(buf, end, sym, spec);
977 #else
978 return special_hex_number(buf, end, value, sizeof(void *));
979 #endif
980 }
981
982 static const struct printf_spec default_str_spec = {
983 .field_width = -1,
984 .precision = -1,
985 };
986
987 static const struct printf_spec default_flag_spec = {
988 .base = 16,
989 .precision = -1,
990 .flags = SPECIAL | SMALL,
991 };
992
993 static const struct printf_spec default_dec_spec = {
994 .base = 10,
995 .precision = -1,
996 };
997
998 static const struct printf_spec default_dec02_spec = {
999 .base = 10,
1000 .field_width = 2,
1001 .precision = -1,
1002 .flags = ZEROPAD,
1003 };
1004
1005 static const struct printf_spec default_dec04_spec = {
1006 .base = 10,
1007 .field_width = 4,
1008 .precision = -1,
1009 .flags = ZEROPAD,
1010 };
1011
1012 static noinline_for_stack
1013 char *resource_string(char *buf, char *end, struct resource *res,
1014 struct printf_spec spec, const char *fmt)
1015 {
1016 #ifndef IO_RSRC_PRINTK_SIZE
1017 #define IO_RSRC_PRINTK_SIZE 6
1018 #endif
1019
1020 #ifndef MEM_RSRC_PRINTK_SIZE
1021 #define MEM_RSRC_PRINTK_SIZE 10
1022 #endif
1023 static const struct printf_spec io_spec = {
1024 .base = 16,
1025 .field_width = IO_RSRC_PRINTK_SIZE,
1026 .precision = -1,
1027 .flags = SPECIAL | SMALL | ZEROPAD,
1028 };
1029 static const struct printf_spec mem_spec = {
1030 .base = 16,
1031 .field_width = MEM_RSRC_PRINTK_SIZE,
1032 .precision = -1,
1033 .flags = SPECIAL | SMALL | ZEROPAD,
1034 };
1035 static const struct printf_spec bus_spec = {
1036 .base = 16,
1037 .field_width = 2,
1038 .precision = -1,
1039 .flags = SMALL | ZEROPAD,
1040 };
1041 static const struct printf_spec str_spec = {
1042 .field_width = -1,
1043 .precision = 10,
1044 .flags = LEFT,
1045 };
1046
1047 /* 32-bit res (sizeof==4): 10 chars in dec, 10 in hex ("0x" + 8)
1048 * 64-bit res (sizeof==8): 20 chars in dec, 18 in hex ("0x" + 16) */
1049 #define RSRC_BUF_SIZE ((2 * sizeof(resource_size_t)) + 4)
1050 #define FLAG_BUF_SIZE (2 * sizeof(res->flags))
1051 #define DECODED_BUF_SIZE sizeof("[mem - 64bit pref window disabled]")
1052 #define RAW_BUF_SIZE sizeof("[mem - flags 0x]")
1053 char sym[max(2*RSRC_BUF_SIZE + DECODED_BUF_SIZE,
1054 2*RSRC_BUF_SIZE + FLAG_BUF_SIZE + RAW_BUF_SIZE)];
1055
1056 char *p = sym, *pend = sym + sizeof(sym);
1057 int decode = (fmt[0] == 'R') ? 1 : 0;
1058 const struct printf_spec *specp;
1059
1060 if (check_pointer(&buf, end, res, spec))
1061 return buf;
1062
1063 *p++ = '[';
1064 if (res->flags & IORESOURCE_IO) {
1065 p = string_nocheck(p, pend, "io ", str_spec);
1066 specp = &io_spec;
1067 } else if (res->flags & IORESOURCE_MEM) {
1068 p = string_nocheck(p, pend, "mem ", str_spec);
1069 specp = &mem_spec;
1070 } else if (res->flags & IORESOURCE_IRQ) {
1071 p = string_nocheck(p, pend, "irq ", str_spec);
1072 specp = &default_dec_spec;
1073 } else if (res->flags & IORESOURCE_DMA) {
1074 p = string_nocheck(p, pend, "dma ", str_spec);
1075 specp = &default_dec_spec;
1076 } else if (res->flags & IORESOURCE_BUS) {
1077 p = string_nocheck(p, pend, "bus ", str_spec);
1078 specp = &bus_spec;
1079 } else {
1080 p = string_nocheck(p, pend, "??? ", str_spec);
1081 specp = &mem_spec;
1082 decode = 0;
1083 }
1084 if (decode && res->flags & IORESOURCE_UNSET) {
1085 p = string_nocheck(p, pend, "size ", str_spec);
1086 p = number(p, pend, resource_size(res), *specp);
1087 } else {
1088 p = number(p, pend, res->start, *specp);
1089 if (res->start != res->end) {
1090 *p++ = '-';
1091 p = number(p, pend, res->end, *specp);
1092 }
1093 }
1094 if (decode) {
1095 if (res->flags & IORESOURCE_MEM_64)
1096 p = string_nocheck(p, pend, " 64bit", str_spec);
1097 if (res->flags & IORESOURCE_PREFETCH)
1098 p = string_nocheck(p, pend, " pref", str_spec);
1099 if (res->flags & IORESOURCE_WINDOW)
1100 p = string_nocheck(p, pend, " window", str_spec);
1101 if (res->flags & IORESOURCE_DISABLED)
1102 p = string_nocheck(p, pend, " disabled", str_spec);
1103 } else {
1104 p = string_nocheck(p, pend, " flags ", str_spec);
1105 p = number(p, pend, res->flags, default_flag_spec);
1106 }
1107 *p++ = ']';
1108 *p = '\0';
1109
1110 return string_nocheck(buf, end, sym, spec);
1111 }
1112
1113 static noinline_for_stack
1114 char *hex_string(char *buf, char *end, u8 *addr, struct printf_spec spec,
1115 const char *fmt)
1116 {
1117 int i, len = 1; /* if we pass '%ph[CDN]', field width remains
1118 negative value, fallback to the default */
1119 char separator;
1120
1121 if (spec.field_width == 0)
1122 /* nothing to print */
1123 return buf;
1124
1125 if (check_pointer(&buf, end, addr, spec))
1126 return buf;
1127
1128 switch (fmt[1]) {
1129 case 'C':
1130 separator = ':';
1131 break;
1132 case 'D':
1133 separator = '-';
1134 break;
1135 case 'N':
1136 separator = 0;
1137 break;
1138 default:
1139 separator = ' ';
1140 break;
1141 }
1142
1143 if (spec.field_width > 0)
1144 len = min_t(int, spec.field_width, 64);
1145
1146 for (i = 0; i < len; ++i) {
1147 if (buf < end)
1148 *buf = hex_asc_hi(addr[i]);
1149 ++buf;
1150 if (buf < end)
1151 *buf = hex_asc_lo(addr[i]);
1152 ++buf;
1153
1154 if (separator && i != len - 1) {
1155 if (buf < end)
1156 *buf = separator;
1157 ++buf;
1158 }
1159 }
1160
1161 return buf;
1162 }
1163
1164 static noinline_for_stack
1165 char *bitmap_string(char *buf, char *end, unsigned long *bitmap,
1166 struct printf_spec spec, const char *fmt)
1167 {
1168 const int CHUNKSZ = 32;
1169 int nr_bits = max_t(int, spec.field_width, 0);
1170 int i, chunksz;
1171 bool first = true;
1172
1173 if (check_pointer(&buf, end, bitmap, spec))
1174 return buf;
1175
1176 /* reused to print numbers */
1177 spec = (struct printf_spec){ .flags = SMALL | ZEROPAD, .base = 16 };
1178
1179 chunksz = nr_bits & (CHUNKSZ - 1);
1180 if (chunksz == 0)
1181 chunksz = CHUNKSZ;
1182
1183 i = ALIGN(nr_bits, CHUNKSZ) - CHUNKSZ;
1184 for (; i >= 0; i -= CHUNKSZ) {
1185 u32 chunkmask, val;
1186 int word, bit;
1187
1188 chunkmask = ((1ULL << chunksz) - 1);
1189 word = i / BITS_PER_LONG;
1190 bit = i % BITS_PER_LONG;
1191 val = (bitmap[word] >> bit) & chunkmask;
1192
1193 if (!first) {
1194 if (buf < end)
1195 *buf = ',';
1196 buf++;
1197 }
1198 first = false;
1199
1200 spec.field_width = DIV_ROUND_UP(chunksz, 4);
1201 buf = number(buf, end, val, spec);
1202
1203 chunksz = CHUNKSZ;
1204 }
1205 return buf;
1206 }
1207
1208 static noinline_for_stack
1209 char *bitmap_list_string(char *buf, char *end, unsigned long *bitmap,
1210 struct printf_spec spec, const char *fmt)
1211 {
1212 int nr_bits = max_t(int, spec.field_width, 0);
1213 /* current bit is 'cur', most recently seen range is [rbot, rtop] */
1214 int cur, rbot, rtop;
1215 bool first = true;
1216
1217 if (check_pointer(&buf, end, bitmap, spec))
1218 return buf;
1219
1220 rbot = cur = find_first_bit(bitmap, nr_bits);
1221 while (cur < nr_bits) {
1222 rtop = cur;
1223 cur = find_next_bit(bitmap, nr_bits, cur + 1);
1224 if (cur < nr_bits && cur <= rtop + 1)
1225 continue;
1226
1227 if (!first) {
1228 if (buf < end)
1229 *buf = ',';
1230 buf++;
1231 }
1232 first = false;
1233
1234 buf = number(buf, end, rbot, default_dec_spec);
1235 if (rbot < rtop) {
1236 if (buf < end)
1237 *buf = '-';
1238 buf++;
1239
1240 buf = number(buf, end, rtop, default_dec_spec);
1241 }
1242
1243 rbot = cur;
1244 }
1245 return buf;
1246 }
1247
1248 static noinline_for_stack
1249 char *mac_address_string(char *buf, char *end, u8 *addr,
1250 struct printf_spec spec, const char *fmt)
1251 {
1252 char mac_addr[sizeof("xx:xx:xx:xx:xx:xx")];
1253 char *p = mac_addr;
1254 int i;
1255 char separator;
1256 bool reversed = false;
1257
1258 if (check_pointer(&buf, end, addr, spec))
1259 return buf;
1260
1261 switch (fmt[1]) {
1262 case 'F':
1263 separator = '-';
1264 break;
1265
1266 case 'R':
1267 reversed = true;
1268 fallthrough;
1269
1270 default:
1271 separator = ':';
1272 break;
1273 }
1274
1275 for (i = 0; i < 6; i++) {
1276 if (reversed)
1277 p = hex_byte_pack(p, addr[5 - i]);
1278 else
1279 p = hex_byte_pack(p, addr[i]);
1280
1281 if (fmt[0] == 'M' && i != 5)
1282 *p++ = separator;
1283 }
1284 *p = '\0';
1285
1286 return string_nocheck(buf, end, mac_addr, spec);
1287 }
1288
1289 static noinline_for_stack
1290 char *ip4_string(char *p, const u8 *addr, const char *fmt)
1291 {
1292 int i;
1293 bool leading_zeros = (fmt[0] == 'i');
1294 int index;
1295 int step;
1296
1297 switch (fmt[2]) {
1298 case 'h':
1299 #ifdef __BIG_ENDIAN
1300 index = 0;
1301 step = 1;
1302 #else
1303 index = 3;
1304 step = -1;
1305 #endif
1306 break;
1307 case 'l':
1308 index = 3;
1309 step = -1;
1310 break;
1311 case 'n':
1312 case 'b':
1313 default:
1314 index = 0;
1315 step = 1;
1316 break;
1317 }
1318 for (i = 0; i < 4; i++) {
1319 char temp[4] __aligned(2); /* hold each IP quad in reverse order */
1320 int digits = put_dec_trunc8(temp, addr[index]) - temp;
1321 if (leading_zeros) {
1322 if (digits < 3)
1323 *p++ = '0';
1324 if (digits < 2)
1325 *p++ = '0';
1326 }
1327 /* reverse the digits in the quad */
1328 while (digits--)
1329 *p++ = temp[digits];
1330 if (i < 3)
1331 *p++ = '.';
1332 index += step;
1333 }
1334 *p = '\0';
1335
1336 return p;
1337 }
1338
1339 static noinline_for_stack
1340 char *ip6_compressed_string(char *p, const char *addr)
1341 {
1342 int i, j, range;
1343 unsigned char zerolength[8];
1344 int longest = 1;
1345 int colonpos = -1;
1346 u16 word;
1347 u8 hi, lo;
1348 bool needcolon = false;
1349 bool useIPv4;
1350 struct in6_addr in6;
1351
1352 memcpy(&in6, addr, sizeof(struct in6_addr));
1353
1354 useIPv4 = ipv6_addr_v4mapped(&in6) || ipv6_addr_is_isatap(&in6);
1355
1356 memset(zerolength, 0, sizeof(zerolength));
1357
1358 if (useIPv4)
1359 range = 6;
1360 else
1361 range = 8;
1362
1363 /* find position of longest 0 run */
1364 for (i = 0; i < range; i++) {
1365 for (j = i; j < range; j++) {
1366 if (in6.s6_addr16[j] != 0)
1367 break;
1368 zerolength[i]++;
1369 }
1370 }
1371 for (i = 0; i < range; i++) {
1372 if (zerolength[i] > longest) {
1373 longest = zerolength[i];
1374 colonpos = i;
1375 }
1376 }
1377 if (longest == 1) /* don't compress a single 0 */
1378 colonpos = -1;
1379
1380 /* emit address */
1381 for (i = 0; i < range; i++) {
1382 if (i == colonpos) {
1383 if (needcolon || i == 0)
1384 *p++ = ':';
1385 *p++ = ':';
1386 needcolon = false;
1387 i += longest - 1;
1388 continue;
1389 }
1390 if (needcolon) {
1391 *p++ = ':';
1392 needcolon = false;
1393 }
1394 /* hex u16 without leading 0s */
1395 word = ntohs(in6.s6_addr16[i]);
1396 hi = word >> 8;
1397 lo = word & 0xff;
1398 if (hi) {
1399 if (hi > 0x0f)
1400 p = hex_byte_pack(p, hi);
1401 else
1402 *p++ = hex_asc_lo(hi);
1403 p = hex_byte_pack(p, lo);
1404 }
1405 else if (lo > 0x0f)
1406 p = hex_byte_pack(p, lo);
1407 else
1408 *p++ = hex_asc_lo(lo);
1409 needcolon = true;
1410 }
1411
1412 if (useIPv4) {
1413 if (needcolon)
1414 *p++ = ':';
1415 p = ip4_string(p, &in6.s6_addr[12], "I4");
1416 }
1417 *p = '\0';
1418
1419 return p;
1420 }
1421
1422 static noinline_for_stack
1423 char *ip6_string(char *p, const char *addr, const char *fmt)
1424 {
1425 int i;
1426
1427 for (i = 0; i < 8; i++) {
1428 p = hex_byte_pack(p, *addr++);
1429 p = hex_byte_pack(p, *addr++);
1430 if (fmt[0] == 'I' && i != 7)
1431 *p++ = ':';
1432 }
1433 *p = '\0';
1434
1435 return p;
1436 }
1437
1438 static noinline_for_stack
1439 char *ip6_addr_string(char *buf, char *end, const u8 *addr,
1440 struct printf_spec spec, const char *fmt)
1441 {
1442 char ip6_addr[sizeof("xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255")];
1443
1444 if (fmt[0] == 'I' && fmt[2] == 'c')
1445 ip6_compressed_string(ip6_addr, addr);
1446 else
1447 ip6_string(ip6_addr, addr, fmt);
1448
1449 return string_nocheck(buf, end, ip6_addr, spec);
1450 }
1451
1452 static noinline_for_stack
1453 char *ip4_addr_string(char *buf, char *end, const u8 *addr,
1454 struct printf_spec spec, const char *fmt)
1455 {
1456 char ip4_addr[sizeof("255.255.255.255")];
1457
1458 ip4_string(ip4_addr, addr, fmt);
1459
1460 return string_nocheck(buf, end, ip4_addr, spec);
1461 }
1462
1463 static noinline_for_stack
1464 char *ip6_addr_string_sa(char *buf, char *end, const struct sockaddr_in6 *sa,
1465 struct printf_spec spec, const char *fmt)
1466 {
1467 bool have_p = false, have_s = false, have_f = false, have_c = false;
1468 char ip6_addr[sizeof("[xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255]") +
1469 sizeof(":12345") + sizeof("/123456789") +
1470 sizeof("%1234567890")];
1471 char *p = ip6_addr, *pend = ip6_addr + sizeof(ip6_addr);
1472 const u8 *addr = (const u8 *) &sa->sin6_addr;
1473 char fmt6[2] = { fmt[0], '6' };
1474 u8 off = 0;
1475
1476 fmt++;
1477 while (isalpha(*++fmt)) {
1478 switch (*fmt) {
1479 case 'p':
1480 have_p = true;
1481 break;
1482 case 'f':
1483 have_f = true;
1484 break;
1485 case 's':
1486 have_s = true;
1487 break;
1488 case 'c':
1489 have_c = true;
1490 break;
1491 }
1492 }
1493
1494 if (have_p || have_s || have_f) {
1495 *p = '[';
1496 off = 1;
1497 }
1498
1499 if (fmt6[0] == 'I' && have_c)
1500 p = ip6_compressed_string(ip6_addr + off, addr);
1501 else
1502 p = ip6_string(ip6_addr + off, addr, fmt6);
1503
1504 if (have_p || have_s || have_f)
1505 *p++ = ']';
1506
1507 if (have_p) {
1508 *p++ = ':';
1509 p = number(p, pend, ntohs(sa->sin6_port), spec);
1510 }
1511 if (have_f) {
1512 *p++ = '/';
1513 p = number(p, pend, ntohl(sa->sin6_flowinfo &
1514 IPV6_FLOWINFO_MASK), spec);
1515 }
1516 if (have_s) {
1517 *p++ = '%';
1518 p = number(p, pend, sa->sin6_scope_id, spec);
1519 }
1520 *p = '\0';
1521
1522 return string_nocheck(buf, end, ip6_addr, spec);
1523 }
1524
1525 static noinline_for_stack
1526 char *ip4_addr_string_sa(char *buf, char *end, const struct sockaddr_in *sa,
1527 struct printf_spec spec, const char *fmt)
1528 {
1529 bool have_p = false;
1530 char *p, ip4_addr[sizeof("255.255.255.255") + sizeof(":12345")];
1531 char *pend = ip4_addr + sizeof(ip4_addr);
1532 const u8 *addr = (const u8 *) &sa->sin_addr.s_addr;
1533 char fmt4[3] = { fmt[0], '4', 0 };
1534
1535 fmt++;
1536 while (isalpha(*++fmt)) {
1537 switch (*fmt) {
1538 case 'p':
1539 have_p = true;
1540 break;
1541 case 'h':
1542 case 'l':
1543 case 'n':
1544 case 'b':
1545 fmt4[2] = *fmt;
1546 break;
1547 }
1548 }
1549
1550 p = ip4_string(ip4_addr, addr, fmt4);
1551 if (have_p) {
1552 *p++ = ':';
1553 p = number(p, pend, ntohs(sa->sin_port), spec);
1554 }
1555 *p = '\0';
1556
1557 return string_nocheck(buf, end, ip4_addr, spec);
1558 }
1559
1560 static noinline_for_stack
1561 char *ip_addr_string(char *buf, char *end, const void *ptr,
1562 struct printf_spec spec, const char *fmt)
1563 {
1564 char *err_fmt_msg;
1565
1566 if (check_pointer(&buf, end, ptr, spec))
1567 return buf;
1568
1569 switch (fmt[1]) {
1570 case '6':
1571 return ip6_addr_string(buf, end, ptr, spec, fmt);
1572 case '4':
1573 return ip4_addr_string(buf, end, ptr, spec, fmt);
1574 case 'S': {
1575 const union {
1576 struct sockaddr raw;
1577 struct sockaddr_in v4;
1578 struct sockaddr_in6 v6;
1579 } *sa = ptr;
1580
1581 switch (sa->raw.sa_family) {
1582 case AF_INET:
1583 return ip4_addr_string_sa(buf, end, &sa->v4, spec, fmt);
1584 case AF_INET6:
1585 return ip6_addr_string_sa(buf, end, &sa->v6, spec, fmt);
1586 default:
1587 return error_string(buf, end, "(einval)", spec);
1588 }}
1589 }
1590
1591 err_fmt_msg = fmt[0] == 'i' ? "(%pi?)" : "(%pI?)";
1592 return error_string(buf, end, err_fmt_msg, spec);
1593 }
1594
1595 static noinline_for_stack
1596 char *escaped_string(char *buf, char *end, u8 *addr, struct printf_spec spec,
1597 const char *fmt)
1598 {
1599 bool found = true;
1600 int count = 1;
1601 unsigned int flags = 0;
1602 int len;
1603
1604 if (spec.field_width == 0)
1605 return buf; /* nothing to print */
1606
1607 if (check_pointer(&buf, end, addr, spec))
1608 return buf;
1609
1610 do {
1611 switch (fmt[count++]) {
1612 case 'a':
1613 flags |= ESCAPE_ANY;
1614 break;
1615 case 'c':
1616 flags |= ESCAPE_SPECIAL;
1617 break;
1618 case 'h':
1619 flags |= ESCAPE_HEX;
1620 break;
1621 case 'n':
1622 flags |= ESCAPE_NULL;
1623 break;
1624 case 'o':
1625 flags |= ESCAPE_OCTAL;
1626 break;
1627 case 'p':
1628 flags |= ESCAPE_NP;
1629 break;
1630 case 's':
1631 flags |= ESCAPE_SPACE;
1632 break;
1633 default:
1634 found = false;
1635 break;
1636 }
1637 } while (found);
1638
1639 if (!flags)
1640 flags = ESCAPE_ANY_NP;
1641
1642 len = spec.field_width < 0 ? 1 : spec.field_width;
1643
1644 /*
1645 * string_escape_mem() writes as many characters as it can to
1646 * the given buffer, and returns the total size of the output
1647 * had the buffer been big enough.
1648 */
1649 buf += string_escape_mem(addr, len, buf, buf < end ? end - buf : 0, flags, NULL);
1650
1651 return buf;
1652 }
1653
1654 static char *va_format(char *buf, char *end, struct va_format *va_fmt,
1655 struct printf_spec spec, const char *fmt)
1656 {
1657 va_list va;
1658
1659 if (check_pointer(&buf, end, va_fmt, spec))
1660 return buf;
1661
1662 va_copy(va, *va_fmt->va);
1663 buf += vsnprintf(buf, end > buf ? end - buf : 0, va_fmt->fmt, va);
1664 va_end(va);
1665
1666 return buf;
1667 }
1668
1669 static noinline_for_stack
1670 char *uuid_string(char *buf, char *end, const u8 *addr,
1671 struct printf_spec spec, const char *fmt)
1672 {
1673 char uuid[UUID_STRING_LEN + 1];
1674 char *p = uuid;
1675 int i;
1676 const u8 *index = uuid_index;
1677 bool uc = false;
1678
1679 if (check_pointer(&buf, end, addr, spec))
1680 return buf;
1681
1682 switch (*(++fmt)) {
1683 case 'L':
1684 uc = true;
1685 fallthrough;
1686 case 'l':
1687 index = guid_index;
1688 break;
1689 case 'B':
1690 uc = true;
1691 break;
1692 }
1693
1694 for (i = 0; i < 16; i++) {
1695 if (uc)
1696 p = hex_byte_pack_upper(p, addr[index[i]]);
1697 else
1698 p = hex_byte_pack(p, addr[index[i]]);
1699 switch (i) {
1700 case 3:
1701 case 5:
1702 case 7:
1703 case 9:
1704 *p++ = '-';
1705 break;
1706 }
1707 }
1708
1709 *p = 0;
1710
1711 return string_nocheck(buf, end, uuid, spec);
1712 }
1713
1714 static noinline_for_stack
1715 char *netdev_bits(char *buf, char *end, const void *addr,
1716 struct printf_spec spec, const char *fmt)
1717 {
1718 unsigned long long num;
1719 int size;
1720
1721 if (check_pointer(&buf, end, addr, spec))
1722 return buf;
1723
1724 switch (fmt[1]) {
1725 case 'F':
1726 num = *(const netdev_features_t *)addr;
1727 size = sizeof(netdev_features_t);
1728 break;
1729 default:
1730 return error_string(buf, end, "(%pN?)", spec);
1731 }
1732
1733 return special_hex_number(buf, end, num, size);
1734 }
1735
1736 static noinline_for_stack
1737 char *fourcc_string(char *buf, char *end, const u32 *fourcc,
1738 struct printf_spec spec, const char *fmt)
1739 {
1740 char output[sizeof("0123 little-endian (0x01234567)")];
1741 char *p = output;
1742 unsigned int i;
1743 u32 val;
1744
1745 if (fmt[1] != 'c' || fmt[2] != 'c')
1746 return error_string(buf, end, "(%p4?)", spec);
1747
1748 if (check_pointer(&buf, end, fourcc, spec))
1749 return buf;
1750
1751 val = *fourcc & ~BIT(31);
1752
1753 for (i = 0; i < sizeof(*fourcc); i++) {
1754 unsigned char c = val >> (i * 8);
1755
1756 /* Print non-control ASCII characters as-is, dot otherwise */
1757 *p++ = isascii(c) && isprint(c) ? c : '.';
1758 }
1759
1760 strcpy(p, *fourcc & BIT(31) ? " big-endian" : " little-endian");
1761 p += strlen(p);
1762
1763 *p++ = ' ';
1764 *p++ = '(';
1765 p = special_hex_number(p, output + sizeof(output) - 2, *fourcc, sizeof(u32));
1766 *p++ = ')';
1767 *p = '\0';
1768
1769 return string(buf, end, output, spec);
1770 }
1771
1772 static noinline_for_stack
1773 char *address_val(char *buf, char *end, const void *addr,
1774 struct printf_spec spec, const char *fmt)
1775 {
1776 unsigned long long num;
1777 int size;
1778
1779 if (check_pointer(&buf, end, addr, spec))
1780 return buf;
1781
1782 switch (fmt[1]) {
1783 case 'd':
1784 num = *(const dma_addr_t *)addr;
1785 size = sizeof(dma_addr_t);
1786 break;
1787 case 'p':
1788 default:
1789 num = *(const phys_addr_t *)addr;
1790 size = sizeof(phys_addr_t);
1791 break;
1792 }
1793
1794 return special_hex_number(buf, end, num, size);
1795 }
1796
1797 static noinline_for_stack
1798 char *date_str(char *buf, char *end, const struct rtc_time *tm, bool r)
1799 {
1800 int year = tm->tm_year + (r ? 0 : 1900);
1801 int mon = tm->tm_mon + (r ? 0 : 1);
1802
1803 buf = number(buf, end, year, default_dec04_spec);
1804 if (buf < end)
1805 *buf = '-';
1806 buf++;
1807
1808 buf = number(buf, end, mon, default_dec02_spec);
1809 if (buf < end)
1810 *buf = '-';
1811 buf++;
1812
1813 return number(buf, end, tm->tm_mday, default_dec02_spec);
1814 }
1815
1816 static noinline_for_stack
1817 char *time_str(char *buf, char *end, const struct rtc_time *tm, bool r)
1818 {
1819 buf = number(buf, end, tm->tm_hour, default_dec02_spec);
1820 if (buf < end)
1821 *buf = ':';
1822 buf++;
1823
1824 buf = number(buf, end, tm->tm_min, default_dec02_spec);
1825 if (buf < end)
1826 *buf = ':';
1827 buf++;
1828
1829 return number(buf, end, tm->tm_sec, default_dec02_spec);
1830 }
1831
1832 static noinline_for_stack
1833 char *rtc_str(char *buf, char *end, const struct rtc_time *tm,
1834 struct printf_spec spec, const char *fmt)
1835 {
1836 bool have_t = true, have_d = true;
1837 bool raw = false;
1838 int count = 2;
1839
1840 if (check_pointer(&buf, end, tm, spec))
1841 return buf;
1842
1843 switch (fmt[count]) {
1844 case 'd':
1845 have_t = false;
1846 count++;
1847 break;
1848 case 't':
1849 have_d = false;
1850 count++;
1851 break;
1852 }
1853
1854 raw = fmt[count] == 'r';
1855
1856 if (have_d)
1857 buf = date_str(buf, end, tm, raw);
1858 if (have_d && have_t) {
1859 /* Respect ISO 8601 */
1860 if (buf < end)
1861 *buf = 'T';
1862 buf++;
1863 }
1864 if (have_t)
1865 buf = time_str(buf, end, tm, raw);
1866
1867 return buf;
1868 }
1869
1870 static noinline_for_stack
1871 char *time64_str(char *buf, char *end, const time64_t time,
1872 struct printf_spec spec, const char *fmt)
1873 {
1874 struct rtc_time rtc_time;
1875 struct tm tm;
1876
1877 time64_to_tm(time, 0, &tm);
1878
1879 rtc_time.tm_sec = tm.tm_sec;
1880 rtc_time.tm_min = tm.tm_min;
1881 rtc_time.tm_hour = tm.tm_hour;
1882 rtc_time.tm_mday = tm.tm_mday;
1883 rtc_time.tm_mon = tm.tm_mon;
1884 rtc_time.tm_year = tm.tm_year;
1885 rtc_time.tm_wday = tm.tm_wday;
1886 rtc_time.tm_yday = tm.tm_yday;
1887
1888 rtc_time.tm_isdst = 0;
1889
1890 return rtc_str(buf, end, &rtc_time, spec, fmt);
1891 }
1892
1893 static noinline_for_stack
1894 char *time_and_date(char *buf, char *end, void *ptr, struct printf_spec spec,
1895 const char *fmt)
1896 {
1897 switch (fmt[1]) {
1898 case 'R':
1899 return rtc_str(buf, end, (const struct rtc_time *)ptr, spec, fmt);
1900 case 'T':
1901 return time64_str(buf, end, *(const time64_t *)ptr, spec, fmt);
1902 default:
1903 return error_string(buf, end, "(%pt?)", spec);
1904 }
1905 }
1906
1907 static noinline_for_stack
1908 char *clock(char *buf, char *end, struct clk *clk, struct printf_spec spec,
1909 const char *fmt)
1910 {
1911 if (!IS_ENABLED(CONFIG_HAVE_CLK))
1912 return error_string(buf, end, "(%pC?)", spec);
1913
1914 if (check_pointer(&buf, end, clk, spec))
1915 return buf;
1916
1917 switch (fmt[1]) {
1918 case 'n':
1919 default:
1920 #ifdef CONFIG_COMMON_CLK
1921 return string(buf, end, __clk_get_name(clk), spec);
1922 #else
1923 return ptr_to_id(buf, end, clk, spec);
1924 #endif
1925 }
1926 }
1927
1928 static
1929 char *format_flags(char *buf, char *end, unsigned long flags,
1930 const struct trace_print_flags *names)
1931 {
1932 unsigned long mask;
1933
1934 for ( ; flags && names->name; names++) {
1935 mask = names->mask;
1936 if ((flags & mask) != mask)
1937 continue;
1938
1939 buf = string(buf, end, names->name, default_str_spec);
1940
1941 flags &= ~mask;
1942 if (flags) {
1943 if (buf < end)
1944 *buf = '|';
1945 buf++;
1946 }
1947 }
1948
1949 if (flags)
1950 buf = number(buf, end, flags, default_flag_spec);
1951
1952 return buf;
1953 }
1954
1955 struct page_flags_fields {
1956 int width;
1957 int shift;
1958 int mask;
1959 const struct printf_spec *spec;
1960 const char *name;
1961 };
1962
1963 static const struct page_flags_fields pff[] = {
1964 {SECTIONS_WIDTH, SECTIONS_PGSHIFT, SECTIONS_MASK,
1965 &default_dec_spec, "section"},
1966 {NODES_WIDTH, NODES_PGSHIFT, NODES_MASK,
1967 &default_dec_spec, "node"},
1968 {ZONES_WIDTH, ZONES_PGSHIFT, ZONES_MASK,
1969 &default_dec_spec, "zone"},
1970 {LAST_CPUPID_WIDTH, LAST_CPUPID_PGSHIFT, LAST_CPUPID_MASK,
1971 &default_flag_spec, "lastcpupid"},
1972 {KASAN_TAG_WIDTH, KASAN_TAG_PGSHIFT, KASAN_TAG_MASK,
1973 &default_flag_spec, "kasantag"},
1974 };
1975
1976 static
1977 char *format_page_flags(char *buf, char *end, unsigned long flags)
1978 {
1979 unsigned long main_flags = flags & (BIT(NR_PAGEFLAGS) - 1);
1980 bool append = false;
1981 int i;
1982
1983 /* Page flags from the main area. */
1984 if (main_flags) {
1985 buf = format_flags(buf, end, main_flags, pageflag_names);
1986 append = true;
1987 }
1988
1989 /* Page flags from the fields area */
1990 for (i = 0; i < ARRAY_SIZE(pff); i++) {
1991 /* Skip undefined fields. */
1992 if (!pff[i].width)
1993 continue;
1994
1995 /* Format: Flag Name + '=' (equals sign) + Number + '|' (separator) */
1996 if (append) {
1997 if (buf < end)
1998 *buf = '|';
1999 buf++;
2000 }
2001
2002 buf = string(buf, end, pff[i].name, default_str_spec);
2003 if (buf < end)
2004 *buf = '=';
2005 buf++;
2006 buf = number(buf, end, (flags >> pff[i].shift) & pff[i].mask,
2007 *pff[i].spec);
2008
2009 append = true;
2010 }
2011
2012 return buf;
2013 }
2014
2015 static noinline_for_stack
2016 char *flags_string(char *buf, char *end, void *flags_ptr,
2017 struct printf_spec spec, const char *fmt)
2018 {
2019 unsigned long flags;
2020 const struct trace_print_flags *names;
2021
2022 if (check_pointer(&buf, end, flags_ptr, spec))
2023 return buf;
2024
2025 switch (fmt[1]) {
2026 case 'p':
2027 return format_page_flags(buf, end, *(unsigned long *)flags_ptr);
2028 case 'v':
2029 flags = *(unsigned long *)flags_ptr;
2030 names = vmaflag_names;
2031 break;
2032 case 'g':
2033 flags = (__force unsigned long)(*(gfp_t *)flags_ptr);
2034 names = gfpflag_names;
2035 break;
2036 default:
2037 return error_string(buf, end, "(%pG?)", spec);
2038 }
2039
2040 return format_flags(buf, end, flags, names);
2041 }
2042
2043 static noinline_for_stack
2044 char *fwnode_full_name_string(struct fwnode_handle *fwnode, char *buf,
2045 char *end)
2046 {
2047 int depth;
2048
2049 /* Loop starting from the root node to the current node. */
2050 for (depth = fwnode_count_parents(fwnode); depth >= 0; depth--) {
2051 struct fwnode_handle *__fwnode =
2052 fwnode_get_nth_parent(fwnode, depth);
2053
2054 buf = string(buf, end, fwnode_get_name_prefix(__fwnode),
2055 default_str_spec);
2056 buf = string(buf, end, fwnode_get_name(__fwnode),
2057 default_str_spec);
2058
2059 fwnode_handle_put(__fwnode);
2060 }
2061
2062 return buf;
2063 }
2064
2065 static noinline_for_stack
2066 char *device_node_string(char *buf, char *end, struct device_node *dn,
2067 struct printf_spec spec, const char *fmt)
2068 {
2069 char tbuf[sizeof("xxxx") + 1];
2070 const char *p;
2071 int ret;
2072 char *buf_start = buf;
2073 struct property *prop;
2074 bool has_mult, pass;
2075
2076 struct printf_spec str_spec = spec;
2077 str_spec.field_width = -1;
2078
2079 if (fmt[0] != 'F')
2080 return error_string(buf, end, "(%pO?)", spec);
2081
2082 if (!IS_ENABLED(CONFIG_OF))
2083 return error_string(buf, end, "(%pOF?)", spec);
2084
2085 if (check_pointer(&buf, end, dn, spec))
2086 return buf;
2087
2088 /* simple case without anything any more format specifiers */
2089 fmt++;
2090 if (fmt[0] == '\0' || strcspn(fmt,"fnpPFcC") > 0)
2091 fmt = "f";
2092
2093 for (pass = false; strspn(fmt,"fnpPFcC"); fmt++, pass = true) {
2094 int precision;
2095 if (pass) {
2096 if (buf < end)
2097 *buf = ':';
2098 buf++;
2099 }
2100
2101 switch (*fmt) {
2102 case 'f': /* full_name */
2103 buf = fwnode_full_name_string(of_fwnode_handle(dn), buf,
2104 end);
2105 break;
2106 case 'n': /* name */
2107 p = fwnode_get_name(of_fwnode_handle(dn));
2108 precision = str_spec.precision;
2109 str_spec.precision = strchrnul(p, '@') - p;
2110 buf = string(buf, end, p, str_spec);
2111 str_spec.precision = precision;
2112 break;
2113 case 'p': /* phandle */
2114 buf = number(buf, end, (unsigned int)dn->phandle, default_dec_spec);
2115 break;
2116 case 'P': /* path-spec */
2117 p = fwnode_get_name(of_fwnode_handle(dn));
2118 if (!p[1])
2119 p = "/";
2120 buf = string(buf, end, p, str_spec);
2121 break;
2122 case 'F': /* flags */
2123 tbuf[0] = of_node_check_flag(dn, OF_DYNAMIC) ? 'D' : '-';
2124 tbuf[1] = of_node_check_flag(dn, OF_DETACHED) ? 'd' : '-';
2125 tbuf[2] = of_node_check_flag(dn, OF_POPULATED) ? 'P' : '-';
2126 tbuf[3] = of_node_check_flag(dn, OF_POPULATED_BUS) ? 'B' : '-';
2127 tbuf[4] = 0;
2128 buf = string_nocheck(buf, end, tbuf, str_spec);
2129 break;
2130 case 'c': /* major compatible string */
2131 ret = of_property_read_string(dn, "compatible", &p);
2132 if (!ret)
2133 buf = string(buf, end, p, str_spec);
2134 break;
2135 case 'C': /* full compatible string */
2136 has_mult = false;
2137 of_property_for_each_string(dn, "compatible", prop, p) {
2138 if (has_mult)
2139 buf = string_nocheck(buf, end, ",", str_spec);
2140 buf = string_nocheck(buf, end, "\"", str_spec);
2141 buf = string(buf, end, p, str_spec);
2142 buf = string_nocheck(buf, end, "\"", str_spec);
2143
2144 has_mult = true;
2145 }
2146 break;
2147 default:
2148 break;
2149 }
2150 }
2151
2152 return widen_string(buf, buf - buf_start, end, spec);
2153 }
2154
2155 static noinline_for_stack
2156 char *fwnode_string(char *buf, char *end, struct fwnode_handle *fwnode,
2157 struct printf_spec spec, const char *fmt)
2158 {
2159 struct printf_spec str_spec = spec;
2160 char *buf_start = buf;
2161
2162 str_spec.field_width = -1;
2163
2164 if (*fmt != 'w')
2165 return error_string(buf, end, "(%pf?)", spec);
2166
2167 if (check_pointer(&buf, end, fwnode, spec))
2168 return buf;
2169
2170 fmt++;
2171
2172 switch (*fmt) {
2173 case 'P': /* name */
2174 buf = string(buf, end, fwnode_get_name(fwnode), str_spec);
2175 break;
2176 case 'f': /* full_name */
2177 default:
2178 buf = fwnode_full_name_string(fwnode, buf, end);
2179 break;
2180 }
2181
2182 return widen_string(buf, buf - buf_start, end, spec);
2183 }
2184
2185 /* Disable pointer hashing if requested */
2186 bool no_hash_pointers __ro_after_init;
2187 EXPORT_SYMBOL_GPL(no_hash_pointers);
2188
2189 int __init no_hash_pointers_enable(char *str)
2190 {
2191 if (no_hash_pointers)
2192 return 0;
2193
2194 no_hash_pointers = true;
2195
2196 pr_warn("**********************************************************\n");
2197 pr_warn("** NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE **\n");
2198 pr_warn("** **\n");
2199 pr_warn("** This system shows unhashed kernel memory addresses **\n");
2200 pr_warn("** via the console, logs, and other interfaces. This **\n");
2201 pr_warn("** might reduce the security of your system. **\n");
2202 pr_warn("** **\n");
2203 pr_warn("** If you see this message and you are not debugging **\n");
2204 pr_warn("** the kernel, report this immediately to your system **\n");
2205 pr_warn("** administrator! **\n");
2206 pr_warn("** **\n");
2207 pr_warn("** NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE **\n");
2208 pr_warn("**********************************************************\n");
2209
2210 return 0;
2211 }
2212 early_param("no_hash_pointers", no_hash_pointers_enable);
2213
2214 /*
2215 * Show a '%p' thing. A kernel extension is that the '%p' is followed
2216 * by an extra set of alphanumeric characters that are extended format
2217 * specifiers.
2218 *
2219 * Please update scripts/checkpatch.pl when adding/removing conversion
2220 * characters. (Search for "check for vsprintf extension").
2221 *
2222 * Right now we handle:
2223 *
2224 * - 'S' For symbolic direct pointers (or function descriptors) with offset
2225 * - 's' For symbolic direct pointers (or function descriptors) without offset
2226 * - '[Ss]R' as above with __builtin_extract_return_addr() translation
2227 * - '[Ff]' %pf and %pF were obsoleted and later removed in favor of
2228 * %ps and %pS. Be careful when re-using these specifiers.
2229 * - 'B' For backtraced symbolic direct pointers with offset
2230 * - 'R' For decoded struct resource, e.g., [mem 0x0-0x1f 64bit pref]
2231 * - 'r' For raw struct resource, e.g., [mem 0x0-0x1f flags 0x201]
2232 * - 'b[l]' For a bitmap, the number of bits is determined by the field
2233 * width which must be explicitly specified either as part of the
2234 * format string '%32b[l]' or through '%*b[l]', [l] selects
2235 * range-list format instead of hex format
2236 * - 'M' For a 6-byte MAC address, it prints the address in the
2237 * usual colon-separated hex notation
2238 * - 'm' For a 6-byte MAC address, it prints the hex address without colons
2239 * - 'MF' For a 6-byte MAC FDDI address, it prints the address
2240 * with a dash-separated hex notation
2241 * - '[mM]R' For a 6-byte MAC address, Reverse order (Bluetooth)
2242 * - 'I' [46] for IPv4/IPv6 addresses printed in the usual way
2243 * IPv4 uses dot-separated decimal without leading 0's (1.2.3.4)
2244 * IPv6 uses colon separated network-order 16 bit hex with leading 0's
2245 * [S][pfs]
2246 * Generic IPv4/IPv6 address (struct sockaddr *) that falls back to
2247 * [4] or [6] and is able to print port [p], flowinfo [f], scope [s]
2248 * - 'i' [46] for 'raw' IPv4/IPv6 addresses
2249 * IPv6 omits the colons (01020304...0f)
2250 * IPv4 uses dot-separated decimal with leading 0's (010.123.045.006)
2251 * [S][pfs]
2252 * Generic IPv4/IPv6 address (struct sockaddr *) that falls back to
2253 * [4] or [6] and is able to print port [p], flowinfo [f], scope [s]
2254 * - '[Ii][4S][hnbl]' IPv4 addresses in host, network, big or little endian order
2255 * - 'I[6S]c' for IPv6 addresses printed as specified by
2256 * https://tools.ietf.org/html/rfc5952
2257 * - 'E[achnops]' For an escaped buffer, where rules are defined by combination
2258 * of the following flags (see string_escape_mem() for the
2259 * details):
2260 * a - ESCAPE_ANY
2261 * c - ESCAPE_SPECIAL
2262 * h - ESCAPE_HEX
2263 * n - ESCAPE_NULL
2264 * o - ESCAPE_OCTAL
2265 * p - ESCAPE_NP
2266 * s - ESCAPE_SPACE
2267 * By default ESCAPE_ANY_NP is used.
2268 * - 'U' For a 16 byte UUID/GUID, it prints the UUID/GUID in the form
2269 * "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx"
2270 * Options for %pU are:
2271 * b big endian lower case hex (default)
2272 * B big endian UPPER case hex
2273 * l little endian lower case hex
2274 * L little endian UPPER case hex
2275 * big endian output byte order is:
2276 * [0][1][2][3]-[4][5]-[6][7]-[8][9]-[10][11][12][13][14][15]
2277 * little endian output byte order is:
2278 * [3][2][1][0]-[5][4]-[7][6]-[8][9]-[10][11][12][13][14][15]
2279 * - 'V' For a struct va_format which contains a format string * and va_list *,
2280 * call vsnprintf(->format, *->va_list).
2281 * Implements a "recursive vsnprintf".
2282 * Do not use this feature without some mechanism to verify the
2283 * correctness of the format string and va_list arguments.
2284 * - 'K' For a kernel pointer that should be hidden from unprivileged users.
2285 * Use only for procfs, sysfs and similar files, not printk(); please
2286 * read the documentation (path below) first.
2287 * - 'NF' For a netdev_features_t
2288 * - '4cc' V4L2 or DRM FourCC code, with endianness and raw numerical value.
2289 * - 'h[CDN]' For a variable-length buffer, it prints it as a hex string with
2290 * a certain separator (' ' by default):
2291 * C colon
2292 * D dash
2293 * N no separator
2294 * The maximum supported length is 64 bytes of the input. Consider
2295 * to use print_hex_dump() for the larger input.
2296 * - 'a[pd]' For address types [p] phys_addr_t, [d] dma_addr_t and derivatives
2297 * (default assumed to be phys_addr_t, passed by reference)
2298 * - 'd[234]' For a dentry name (optionally 2-4 last components)
2299 * - 'D[234]' Same as 'd' but for a struct file
2300 * - 'g' For block_device name (gendisk + partition number)
2301 * - 't[RT][dt][r]' For time and date as represented by:
2302 * R struct rtc_time
2303 * T time64_t
2304 * - 'C' For a clock, it prints the name (Common Clock Framework) or address
2305 * (legacy clock framework) of the clock
2306 * - 'Cn' For a clock, it prints the name (Common Clock Framework) or address
2307 * (legacy clock framework) of the clock
2308 * - 'G' For flags to be printed as a collection of symbolic strings that would
2309 * construct the specific value. Supported flags given by option:
2310 * p page flags (see struct page) given as pointer to unsigned long
2311 * g gfp flags (GFP_* and __GFP_*) given as pointer to gfp_t
2312 * v vma flags (VM_*) given as pointer to unsigned long
2313 * - 'OF[fnpPcCF]' For a device tree object
2314 * Without any optional arguments prints the full_name
2315 * f device node full_name
2316 * n device node name
2317 * p device node phandle
2318 * P device node path spec (name + @unit)
2319 * F device node flags
2320 * c major compatible string
2321 * C full compatible string
2322 * - 'fw[fP]' For a firmware node (struct fwnode_handle) pointer
2323 * Without an option prints the full name of the node
2324 * f full name
2325 * P node name, including a possible unit address
2326 * - 'x' For printing the address unmodified. Equivalent to "%lx".
2327 * Please read the documentation (path below) before using!
2328 * - '[ku]s' For a BPF/tracing related format specifier, e.g. used out of
2329 * bpf_trace_printk() where [ku] prefix specifies either kernel (k)
2330 * or user (u) memory to probe, and:
2331 * s a string, equivalent to "%s" on direct vsnprintf() use
2332 *
2333 * ** When making changes please also update:
2334 * Documentation/core-api/printk-formats.rst
2335 *
2336 * Note: The default behaviour (unadorned %p) is to hash the address,
2337 * rendering it useful as a unique identifier.
2338 */
2339 static noinline_for_stack
2340 char *pointer(const char *fmt, char *buf, char *end, void *ptr,
2341 struct printf_spec spec)
2342 {
2343 switch (*fmt) {
2344 case 'S':
2345 case 's':
2346 ptr = dereference_symbol_descriptor(ptr);
2347 fallthrough;
2348 case 'B':
2349 return symbol_string(buf, end, ptr, spec, fmt);
2350 case 'R':
2351 case 'r':
2352 return resource_string(buf, end, ptr, spec, fmt);
2353 case 'h':
2354 return hex_string(buf, end, ptr, spec, fmt);
2355 case 'b':
2356 switch (fmt[1]) {
2357 case 'l':
2358 return bitmap_list_string(buf, end, ptr, spec, fmt);
2359 default:
2360 return bitmap_string(buf, end, ptr, spec, fmt);
2361 }
2362 case 'M': /* Colon separated: 00:01:02:03:04:05 */
2363 case 'm': /* Contiguous: 000102030405 */
2364 /* [mM]F (FDDI) */
2365 /* [mM]R (Reverse order; Bluetooth) */
2366 return mac_address_string(buf, end, ptr, spec, fmt);
2367 case 'I': /* Formatted IP supported
2368 * 4: 1.2.3.4
2369 * 6: 0001:0203:...:0708
2370 * 6c: 1::708 or 1::1.2.3.4
2371 */
2372 case 'i': /* Contiguous:
2373 * 4: 001.002.003.004
2374 * 6: 000102...0f
2375 */
2376 return ip_addr_string(buf, end, ptr, spec, fmt);
2377 case 'E':
2378 return escaped_string(buf, end, ptr, spec, fmt);
2379 case 'U':
2380 return uuid_string(buf, end, ptr, spec, fmt);
2381 case 'V':
2382 return va_format(buf, end, ptr, spec, fmt);
2383 case 'K':
2384 return restricted_pointer(buf, end, ptr, spec);
2385 case 'N':
2386 return netdev_bits(buf, end, ptr, spec, fmt);
2387 case '4':
2388 return fourcc_string(buf, end, ptr, spec, fmt);
2389 case 'a':
2390 return address_val(buf, end, ptr, spec, fmt);
2391 case 'd':
2392 return dentry_name(buf, end, ptr, spec, fmt);
2393 case 't':
2394 return time_and_date(buf, end, ptr, spec, fmt);
2395 case 'C':
2396 return clock(buf, end, ptr, spec, fmt);
2397 case 'D':
2398 return file_dentry_name(buf, end, ptr, spec, fmt);
2399 #ifdef CONFIG_BLOCK
2400 case 'g':
2401 return bdev_name(buf, end, ptr, spec, fmt);
2402 #endif
2403
2404 case 'G':
2405 return flags_string(buf, end, ptr, spec, fmt);
2406 case 'O':
2407 return device_node_string(buf, end, ptr, spec, fmt + 1);
2408 case 'f':
2409 return fwnode_string(buf, end, ptr, spec, fmt + 1);
2410 case 'x':
2411 return pointer_string(buf, end, ptr, spec);
2412 case 'e':
2413 /* %pe with a non-ERR_PTR gets treated as plain %p */
2414 if (!IS_ERR(ptr))
2415 break;
2416 return err_ptr(buf, end, ptr, spec);
2417 case 'u':
2418 case 'k':
2419 switch (fmt[1]) {
2420 case 's':
2421 return string(buf, end, ptr, spec);
2422 default:
2423 return error_string(buf, end, "(einval)", spec);
2424 }
2425 }
2426
2427 /*
2428 * default is to _not_ leak addresses, so hash before printing,
2429 * unless no_hash_pointers is specified on the command line.
2430 */
2431 if (unlikely(no_hash_pointers))
2432 return pointer_string(buf, end, ptr, spec);
2433 else
2434 return ptr_to_id(buf, end, ptr, spec);
2435 }
2436
2437 /*
2438 * Helper function to decode printf style format.
2439 * Each call decode a token from the format and return the
2440 * number of characters read (or likely the delta where it wants
2441 * to go on the next call).
2442 * The decoded token is returned through the parameters
2443 *
2444 * 'h', 'l', or 'L' for integer fields
2445 * 'z' support added 23/7/1999 S.H.
2446 * 'z' changed to 'Z' --davidm 1/25/99
2447 * 'Z' changed to 'z' --adobriyan 2017-01-25
2448 * 't' added for ptrdiff_t
2449 *
2450 * @fmt: the format string
2451 * @type of the token returned
2452 * @flags: various flags such as +, -, # tokens..
2453 * @field_width: overwritten width
2454 * @base: base of the number (octal, hex, ...)
2455 * @precision: precision of a number
2456 * @qualifier: qualifier of a number (long, size_t, ...)
2457 */
2458 static noinline_for_stack
2459 int format_decode(const char *fmt, struct printf_spec *spec)
2460 {
2461 const char *start = fmt;
2462 char qualifier;
2463
2464 /* we finished early by reading the field width */
2465 if (spec->type == FORMAT_TYPE_WIDTH) {
2466 if (spec->field_width < 0) {
2467 spec->field_width = -spec->field_width;
2468 spec->flags |= LEFT;
2469 }
2470 spec->type = FORMAT_TYPE_NONE;
2471 goto precision;
2472 }
2473
2474 /* we finished early by reading the precision */
2475 if (spec->type == FORMAT_TYPE_PRECISION) {
2476 if (spec->precision < 0)
2477 spec->precision = 0;
2478
2479 spec->type = FORMAT_TYPE_NONE;
2480 goto qualifier;
2481 }
2482
2483 /* By default */
2484 spec->type = FORMAT_TYPE_NONE;
2485
2486 for (; *fmt ; ++fmt) {
2487 if (*fmt == '%')
2488 break;
2489 }
2490
2491 /* Return the current non-format string */
2492 if (fmt != start || !*fmt)
2493 return fmt - start;
2494
2495 /* Process flags */
2496 spec->flags = 0;
2497
2498 while (1) { /* this also skips first '%' */
2499 bool found = true;
2500
2501 ++fmt;
2502
2503 switch (*fmt) {
2504 case '-': spec->flags |= LEFT; break;
2505 case '+': spec->flags |= PLUS; break;
2506 case ' ': spec->flags |= SPACE; break;
2507 case '#': spec->flags |= SPECIAL; break;
2508 case '0': spec->flags |= ZEROPAD; break;
2509 default: found = false;
2510 }
2511
2512 if (!found)
2513 break;
2514 }
2515
2516 /* get field width */
2517 spec->field_width = -1;
2518
2519 if (isdigit(*fmt))
2520 spec->field_width = skip_atoi(&fmt);
2521 else if (*fmt == '*') {
2522 /* it's the next argument */
2523 spec->type = FORMAT_TYPE_WIDTH;
2524 return ++fmt - start;
2525 }
2526
2527 precision:
2528 /* get the precision */
2529 spec->precision = -1;
2530 if (*fmt == '.') {
2531 ++fmt;
2532 if (isdigit(*fmt)) {
2533 spec->precision = skip_atoi(&fmt);
2534 if (spec->precision < 0)
2535 spec->precision = 0;
2536 } else if (*fmt == '*') {
2537 /* it's the next argument */
2538 spec->type = FORMAT_TYPE_PRECISION;
2539 return ++fmt - start;
2540 }
2541 }
2542
2543 qualifier:
2544 /* get the conversion qualifier */
2545 qualifier = 0;
2546 if (*fmt == 'h' || _tolower(*fmt) == 'l' ||
2547 *fmt == 'z' || *fmt == 't') {
2548 qualifier = *fmt++;
2549 if (unlikely(qualifier == *fmt)) {
2550 if (qualifier == 'l') {
2551 qualifier = 'L';
2552 ++fmt;
2553 } else if (qualifier == 'h') {
2554 qualifier = 'H';
2555 ++fmt;
2556 }
2557 }
2558 }
2559
2560 /* default base */
2561 spec->base = 10;
2562 switch (*fmt) {
2563 case 'c':
2564 spec->type = FORMAT_TYPE_CHAR;
2565 return ++fmt - start;
2566
2567 case 's':
2568 spec->type = FORMAT_TYPE_STR;
2569 return ++fmt - start;
2570
2571 case 'p':
2572 spec->type = FORMAT_TYPE_PTR;
2573 return ++fmt - start;
2574
2575 case '%':
2576 spec->type = FORMAT_TYPE_PERCENT_CHAR;
2577 return ++fmt - start;
2578
2579 /* integer number formats - set up the flags and "break" */
2580 case 'o':
2581 spec->base = 8;
2582 break;
2583
2584 case 'x':
2585 spec->flags |= SMALL;
2586 fallthrough;
2587
2588 case 'X':
2589 spec->base = 16;
2590 break;
2591
2592 case 'd':
2593 case 'i':
2594 spec->flags |= SIGN;
2595 break;
2596 case 'u':
2597 break;
2598
2599 case 'n':
2600 /*
2601 * Since %n poses a greater security risk than
2602 * utility, treat it as any other invalid or
2603 * unsupported format specifier.
2604 */
2605 fallthrough;
2606
2607 default:
2608 WARN_ONCE(1, "Please remove unsupported %%%c in format string\n", *fmt);
2609 spec->type = FORMAT_TYPE_INVALID;
2610 return fmt - start;
2611 }
2612
2613 if (qualifier == 'L')
2614 spec->type = FORMAT_TYPE_LONG_LONG;
2615 else if (qualifier == 'l') {
2616 BUILD_BUG_ON(FORMAT_TYPE_ULONG + SIGN != FORMAT_TYPE_LONG);
2617 spec->type = FORMAT_TYPE_ULONG + (spec->flags & SIGN);
2618 } else if (qualifier == 'z') {
2619 spec->type = FORMAT_TYPE_SIZE_T;
2620 } else if (qualifier == 't') {
2621 spec->type = FORMAT_TYPE_PTRDIFF;
2622 } else if (qualifier == 'H') {
2623 BUILD_BUG_ON(FORMAT_TYPE_UBYTE + SIGN != FORMAT_TYPE_BYTE);
2624 spec->type = FORMAT_TYPE_UBYTE + (spec->flags & SIGN);
2625 } else if (qualifier == 'h') {
2626 BUILD_BUG_ON(FORMAT_TYPE_USHORT + SIGN != FORMAT_TYPE_SHORT);
2627 spec->type = FORMAT_TYPE_USHORT + (spec->flags & SIGN);
2628 } else {
2629 BUILD_BUG_ON(FORMAT_TYPE_UINT + SIGN != FORMAT_TYPE_INT);
2630 spec->type = FORMAT_TYPE_UINT + (spec->flags & SIGN);
2631 }
2632
2633 return ++fmt - start;
2634 }
2635
2636 static void
2637 set_field_width(struct printf_spec *spec, int width)
2638 {
2639 spec->field_width = width;
2640 if (WARN_ONCE(spec->field_width != width, "field width %d too large", width)) {
2641 spec->field_width = clamp(width, -FIELD_WIDTH_MAX, FIELD_WIDTH_MAX);
2642 }
2643 }
2644
2645 static void
2646 set_precision(struct printf_spec *spec, int prec)
2647 {
2648 spec->precision = prec;
2649 if (WARN_ONCE(spec->precision != prec, "precision %d too large", prec)) {
2650 spec->precision = clamp(prec, 0, PRECISION_MAX);
2651 }
2652 }
2653
2654 /**
2655 * vsnprintf - Format a string and place it in a buffer
2656 * @buf: The buffer to place the result into
2657 * @size: The size of the buffer, including the trailing null space
2658 * @fmt: The format string to use
2659 * @args: Arguments for the format string
2660 *
2661 * This function generally follows C99 vsnprintf, but has some
2662 * extensions and a few limitations:
2663 *
2664 * - ``%n`` is unsupported
2665 * - ``%p*`` is handled by pointer()
2666 *
2667 * See pointer() or Documentation/core-api/printk-formats.rst for more
2668 * extensive description.
2669 *
2670 * **Please update the documentation in both places when making changes**
2671 *
2672 * The return value is the number of characters which would
2673 * be generated for the given input, excluding the trailing
2674 * '\0', as per ISO C99. If you want to have the exact
2675 * number of characters written into @buf as return value
2676 * (not including the trailing '\0'), use vscnprintf(). If the
2677 * return is greater than or equal to @size, the resulting
2678 * string is truncated.
2679 *
2680 * If you're not already dealing with a va_list consider using snprintf().
2681 */
2682 int vsnprintf(char *buf, size_t size, const char *fmt, va_list args)
2683 {
2684 unsigned long long num;
2685 char *str, *end;
2686 struct printf_spec spec = {0};
2687
2688 /* Reject out-of-range values early. Large positive sizes are
2689 used for unknown buffer sizes. */
2690 if (WARN_ON_ONCE(size > INT_MAX))
2691 return 0;
2692
2693 str = buf;
2694 end = buf + size;
2695
2696 /* Make sure end is always >= buf */
2697 if (end < buf) {
2698 end = ((void *)-1);
2699 size = end - buf;
2700 }
2701
2702 while (*fmt) {
2703 const char *old_fmt = fmt;
2704 int read = format_decode(fmt, &spec);
2705
2706 fmt += read;
2707
2708 switch (spec.type) {
2709 case FORMAT_TYPE_NONE: {
2710 int copy = read;
2711 if (str < end) {
2712 if (copy > end - str)
2713 copy = end - str;
2714 memcpy(str, old_fmt, copy);
2715 }
2716 str += read;
2717 break;
2718 }
2719
2720 case FORMAT_TYPE_WIDTH:
2721 set_field_width(&spec, va_arg(args, int));
2722 break;
2723
2724 case FORMAT_TYPE_PRECISION:
2725 set_precision(&spec, va_arg(args, int));
2726 break;
2727
2728 case FORMAT_TYPE_CHAR: {
2729 char c;
2730
2731 if (!(spec.flags & LEFT)) {
2732 while (--spec.field_width > 0) {
2733 if (str < end)
2734 *str = ' ';
2735 ++str;
2736
2737 }
2738 }
2739 c = (unsigned char) va_arg(args, int);
2740 if (str < end)
2741 *str = c;
2742 ++str;
2743 while (--spec.field_width > 0) {
2744 if (str < end)
2745 *str = ' ';
2746 ++str;
2747 }
2748 break;
2749 }
2750
2751 case FORMAT_TYPE_STR:
2752 str = string(str, end, va_arg(args, char *), spec);
2753 break;
2754
2755 case FORMAT_TYPE_PTR:
2756 str = pointer(fmt, str, end, va_arg(args, void *),
2757 spec);
2758 while (isalnum(*fmt))
2759 fmt++;
2760 break;
2761
2762 case FORMAT_TYPE_PERCENT_CHAR:
2763 if (str < end)
2764 *str = '%';
2765 ++str;
2766 break;
2767
2768 case FORMAT_TYPE_INVALID:
2769 /*
2770 * Presumably the arguments passed gcc's type
2771 * checking, but there is no safe or sane way
2772 * for us to continue parsing the format and
2773 * fetching from the va_list; the remaining
2774 * specifiers and arguments would be out of
2775 * sync.
2776 */
2777 goto out;
2778
2779 default:
2780 switch (spec.type) {
2781 case FORMAT_TYPE_LONG_LONG:
2782 num = va_arg(args, long long);
2783 break;
2784 case FORMAT_TYPE_ULONG:
2785 num = va_arg(args, unsigned long);
2786 break;
2787 case FORMAT_TYPE_LONG:
2788 num = va_arg(args, long);
2789 break;
2790 case FORMAT_TYPE_SIZE_T:
2791 if (spec.flags & SIGN)
2792 num = va_arg(args, ssize_t);
2793 else
2794 num = va_arg(args, size_t);
2795 break;
2796 case FORMAT_TYPE_PTRDIFF:
2797 num = va_arg(args, ptrdiff_t);
2798 break;
2799 case FORMAT_TYPE_UBYTE:
2800 num = (unsigned char) va_arg(args, int);
2801 break;
2802 case FORMAT_TYPE_BYTE:
2803 num = (signed char) va_arg(args, int);
2804 break;
2805 case FORMAT_TYPE_USHORT:
2806 num = (unsigned short) va_arg(args, int);
2807 break;
2808 case FORMAT_TYPE_SHORT:
2809 num = (short) va_arg(args, int);
2810 break;
2811 case FORMAT_TYPE_INT:
2812 num = (int) va_arg(args, int);
2813 break;
2814 default:
2815 num = va_arg(args, unsigned int);
2816 }
2817
2818 str = number(str, end, num, spec);
2819 }
2820 }
2821
2822 out:
2823 if (size > 0) {
2824 if (str < end)
2825 *str = '\0';
2826 else
2827 end[-1] = '\0';
2828 }
2829
2830 /* the trailing null byte doesn't count towards the total */
2831 return str-buf;
2832
2833 }
2834 EXPORT_SYMBOL(vsnprintf);
2835
2836 /**
2837 * vscnprintf - Format a string and place it in a buffer
2838 * @buf: The buffer to place the result into
2839 * @size: The size of the buffer, including the trailing null space
2840 * @fmt: The format string to use
2841 * @args: Arguments for the format string
2842 *
2843 * The return value is the number of characters which have been written into
2844 * the @buf not including the trailing '\0'. If @size is == 0 the function
2845 * returns 0.
2846 *
2847 * If you're not already dealing with a va_list consider using scnprintf().
2848 *
2849 * See the vsnprintf() documentation for format string extensions over C99.
2850 */
2851 int vscnprintf(char *buf, size_t size, const char *fmt, va_list args)
2852 {
2853 int i;
2854
2855 i = vsnprintf(buf, size, fmt, args);
2856
2857 if (likely(i < size))
2858 return i;
2859 if (size != 0)
2860 return size - 1;
2861 return 0;
2862 }
2863 EXPORT_SYMBOL(vscnprintf);
2864
2865 /**
2866 * snprintf - Format a string and place it in a buffer
2867 * @buf: The buffer to place the result into
2868 * @size: The size of the buffer, including the trailing null space
2869 * @fmt: The format string to use
2870 * @...: Arguments for the format string
2871 *
2872 * The return value is the number of characters which would be
2873 * generated for the given input, excluding the trailing null,
2874 * as per ISO C99. If the return is greater than or equal to
2875 * @size, the resulting string is truncated.
2876 *
2877 * See the vsnprintf() documentation for format string extensions over C99.
2878 */
2879 int snprintf(char *buf, size_t size, const char *fmt, ...)
2880 {
2881 va_list args;
2882 int i;
2883
2884 va_start(args, fmt);
2885 i = vsnprintf(buf, size, fmt, args);
2886 va_end(args);
2887
2888 return i;
2889 }
2890 EXPORT_SYMBOL(snprintf);
2891
2892 /**
2893 * scnprintf - Format a string and place it in a buffer
2894 * @buf: The buffer to place the result into
2895 * @size: The size of the buffer, including the trailing null space
2896 * @fmt: The format string to use
2897 * @...: Arguments for the format string
2898 *
2899 * The return value is the number of characters written into @buf not including
2900 * the trailing '\0'. If @size is == 0 the function returns 0.
2901 */
2902
2903 int scnprintf(char *buf, size_t size, const char *fmt, ...)
2904 {
2905 va_list args;
2906 int i;
2907
2908 va_start(args, fmt);
2909 i = vscnprintf(buf, size, fmt, args);
2910 va_end(args);
2911
2912 return i;
2913 }
2914 EXPORT_SYMBOL(scnprintf);
2915
2916 /**
2917 * vsprintf - Format a string and place it in a buffer
2918 * @buf: The buffer to place the result into
2919 * @fmt: The format string to use
2920 * @args: Arguments for the format string
2921 *
2922 * The function returns the number of characters written
2923 * into @buf. Use vsnprintf() or vscnprintf() in order to avoid
2924 * buffer overflows.
2925 *
2926 * If you're not already dealing with a va_list consider using sprintf().
2927 *
2928 * See the vsnprintf() documentation for format string extensions over C99.
2929 */
2930 int vsprintf(char *buf, const char *fmt, va_list args)
2931 {
2932 return vsnprintf(buf, INT_MAX, fmt, args);
2933 }
2934 EXPORT_SYMBOL(vsprintf);
2935
2936 /**
2937 * sprintf - Format a string and place it in a buffer
2938 * @buf: The buffer to place the result into
2939 * @fmt: The format string to use
2940 * @...: Arguments for the format string
2941 *
2942 * The function returns the number of characters written
2943 * into @buf. Use snprintf() or scnprintf() in order to avoid
2944 * buffer overflows.
2945 *
2946 * See the vsnprintf() documentation for format string extensions over C99.
2947 */
2948 int sprintf(char *buf, const char *fmt, ...)
2949 {
2950 va_list args;
2951 int i;
2952
2953 va_start(args, fmt);
2954 i = vsnprintf(buf, INT_MAX, fmt, args);
2955 va_end(args);
2956
2957 return i;
2958 }
2959 EXPORT_SYMBOL(sprintf);
2960
2961 #ifdef CONFIG_BINARY_PRINTF
2962 /*
2963 * bprintf service:
2964 * vbin_printf() - VA arguments to binary data
2965 * bstr_printf() - Binary data to text string
2966 */
2967
2968 /**
2969 * vbin_printf - Parse a format string and place args' binary value in a buffer
2970 * @bin_buf: The buffer to place args' binary value
2971 * @size: The size of the buffer(by words(32bits), not characters)
2972 * @fmt: The format string to use
2973 * @args: Arguments for the format string
2974 *
2975 * The format follows C99 vsnprintf, except %n is ignored, and its argument
2976 * is skipped.
2977 *
2978 * The return value is the number of words(32bits) which would be generated for
2979 * the given input.
2980 *
2981 * NOTE:
2982 * If the return value is greater than @size, the resulting bin_buf is NOT
2983 * valid for bstr_printf().
2984 */
2985 int vbin_printf(u32 *bin_buf, size_t size, const char *fmt, va_list args)
2986 {
2987 struct printf_spec spec = {0};
2988 char *str, *end;
2989 int width;
2990
2991 str = (char *)bin_buf;
2992 end = (char *)(bin_buf + size);
2993
2994 #define save_arg(type) \
2995 ({ \
2996 unsigned long long value; \
2997 if (sizeof(type) == 8) { \
2998 unsigned long long val8; \
2999 str = PTR_ALIGN(str, sizeof(u32)); \
3000 val8 = va_arg(args, unsigned long long); \
3001 if (str + sizeof(type) <= end) { \
3002 *(u32 *)str = *(u32 *)&val8; \
3003 *(u32 *)(str + 4) = *((u32 *)&val8 + 1); \
3004 } \
3005 value = val8; \
3006 } else { \
3007 unsigned int val4; \
3008 str = PTR_ALIGN(str, sizeof(type)); \
3009 val4 = va_arg(args, int); \
3010 if (str + sizeof(type) <= end) \
3011 *(typeof(type) *)str = (type)(long)val4; \
3012 value = (unsigned long long)val4; \
3013 } \
3014 str += sizeof(type); \
3015 value; \
3016 })
3017
3018 while (*fmt) {
3019 int read = format_decode(fmt, &spec);
3020
3021 fmt += read;
3022
3023 switch (spec.type) {
3024 case FORMAT_TYPE_NONE:
3025 case FORMAT_TYPE_PERCENT_CHAR:
3026 break;
3027 case FORMAT_TYPE_INVALID:
3028 goto out;
3029
3030 case FORMAT_TYPE_WIDTH:
3031 case FORMAT_TYPE_PRECISION:
3032 width = (int)save_arg(int);
3033 /* Pointers may require the width */
3034 if (*fmt == 'p')
3035 set_field_width(&spec, width);
3036 break;
3037
3038 case FORMAT_TYPE_CHAR:
3039 save_arg(char);
3040 break;
3041
3042 case FORMAT_TYPE_STR: {
3043 const char *save_str = va_arg(args, char *);
3044 const char *err_msg;
3045 size_t len;
3046
3047 err_msg = check_pointer_msg(save_str);
3048 if (err_msg)
3049 save_str = err_msg;
3050
3051 len = strlen(save_str) + 1;
3052 if (str + len < end)
3053 memcpy(str, save_str, len);
3054 str += len;
3055 break;
3056 }
3057
3058 case FORMAT_TYPE_PTR:
3059 /* Dereferenced pointers must be done now */
3060 switch (*fmt) {
3061 /* Dereference of functions is still OK */
3062 case 'S':
3063 case 's':
3064 case 'x':
3065 case 'K':
3066 case 'e':
3067 save_arg(void *);
3068 break;
3069 default:
3070 if (!isalnum(*fmt)) {
3071 save_arg(void *);
3072 break;
3073 }
3074 str = pointer(fmt, str, end, va_arg(args, void *),
3075 spec);
3076 if (str + 1 < end)
3077 *str++ = '\0';
3078 else
3079 end[-1] = '\0'; /* Must be nul terminated */
3080 }
3081 /* skip all alphanumeric pointer suffixes */
3082 while (isalnum(*fmt))
3083 fmt++;
3084 break;
3085
3086 default:
3087 switch (spec.type) {
3088
3089 case FORMAT_TYPE_LONG_LONG:
3090 save_arg(long long);
3091 break;
3092 case FORMAT_TYPE_ULONG:
3093 case FORMAT_TYPE_LONG:
3094 save_arg(unsigned long);
3095 break;
3096 case FORMAT_TYPE_SIZE_T:
3097 save_arg(size_t);
3098 break;
3099 case FORMAT_TYPE_PTRDIFF:
3100 save_arg(ptrdiff_t);
3101 break;
3102 case FORMAT_TYPE_UBYTE:
3103 case FORMAT_TYPE_BYTE:
3104 save_arg(char);
3105 break;
3106 case FORMAT_TYPE_USHORT:
3107 case FORMAT_TYPE_SHORT:
3108 save_arg(short);
3109 break;
3110 default:
3111 save_arg(int);
3112 }
3113 }
3114 }
3115
3116 out:
3117 return (u32 *)(PTR_ALIGN(str, sizeof(u32))) - bin_buf;
3118 #undef save_arg
3119 }
3120 EXPORT_SYMBOL_GPL(vbin_printf);
3121
3122 /**
3123 * bstr_printf - Format a string from binary arguments and place it in a buffer
3124 * @buf: The buffer to place the result into
3125 * @size: The size of the buffer, including the trailing null space
3126 * @fmt: The format string to use
3127 * @bin_buf: Binary arguments for the format string
3128 *
3129 * This function like C99 vsnprintf, but the difference is that vsnprintf gets
3130 * arguments from stack, and bstr_printf gets arguments from @bin_buf which is
3131 * a binary buffer that generated by vbin_printf.
3132 *
3133 * The format follows C99 vsnprintf, but has some extensions:
3134 * see vsnprintf comment for details.
3135 *
3136 * The return value is the number of characters which would
3137 * be generated for the given input, excluding the trailing
3138 * '\0', as per ISO C99. If you want to have the exact
3139 * number of characters written into @buf as return value
3140 * (not including the trailing '\0'), use vscnprintf(). If the
3141 * return is greater than or equal to @size, the resulting
3142 * string is truncated.
3143 */
3144 int bstr_printf(char *buf, size_t size, const char *fmt, const u32 *bin_buf)
3145 {
3146 struct printf_spec spec = {0};
3147 char *str, *end;
3148 const char *args = (const char *)bin_buf;
3149
3150 if (WARN_ON_ONCE(size > INT_MAX))
3151 return 0;
3152
3153 str = buf;
3154 end = buf + size;
3155
3156 #define get_arg(type) \
3157 ({ \
3158 typeof(type) value; \
3159 if (sizeof(type) == 8) { \
3160 args = PTR_ALIGN(args, sizeof(u32)); \
3161 *(u32 *)&value = *(u32 *)args; \
3162 *((u32 *)&value + 1) = *(u32 *)(args + 4); \
3163 } else { \
3164 args = PTR_ALIGN(args, sizeof(type)); \
3165 value = *(typeof(type) *)args; \
3166 } \
3167 args += sizeof(type); \
3168 value; \
3169 })
3170
3171 /* Make sure end is always >= buf */
3172 if (end < buf) {
3173 end = ((void *)-1);
3174 size = end - buf;
3175 }
3176
3177 while (*fmt) {
3178 const char *old_fmt = fmt;
3179 int read = format_decode(fmt, &spec);
3180
3181 fmt += read;
3182
3183 switch (spec.type) {
3184 case FORMAT_TYPE_NONE: {
3185 int copy = read;
3186 if (str < end) {
3187 if (copy > end - str)
3188 copy = end - str;
3189 memcpy(str, old_fmt, copy);
3190 }
3191 str += read;
3192 break;
3193 }
3194
3195 case FORMAT_TYPE_WIDTH:
3196 set_field_width(&spec, get_arg(int));
3197 break;
3198
3199 case FORMAT_TYPE_PRECISION:
3200 set_precision(&spec, get_arg(int));
3201 break;
3202
3203 case FORMAT_TYPE_CHAR: {
3204 char c;
3205
3206 if (!(spec.flags & LEFT)) {
3207 while (--spec.field_width > 0) {
3208 if (str < end)
3209 *str = ' ';
3210 ++str;
3211 }
3212 }
3213 c = (unsigned char) get_arg(char);
3214 if (str < end)
3215 *str = c;
3216 ++str;
3217 while (--spec.field_width > 0) {
3218 if (str < end)
3219 *str = ' ';
3220 ++str;
3221 }
3222 break;
3223 }
3224
3225 case FORMAT_TYPE_STR: {
3226 const char *str_arg = args;
3227 args += strlen(str_arg) + 1;
3228 str = string(str, end, (char *)str_arg, spec);
3229 break;
3230 }
3231
3232 case FORMAT_TYPE_PTR: {
3233 bool process = false;
3234 int copy, len;
3235 /* Non function dereferences were already done */
3236 switch (*fmt) {
3237 case 'S':
3238 case 's':
3239 case 'x':
3240 case 'K':
3241 case 'e':
3242 process = true;
3243 break;
3244 default:
3245 if (!isalnum(*fmt)) {
3246 process = true;
3247 break;
3248 }
3249 /* Pointer dereference was already processed */
3250 if (str < end) {
3251 len = copy = strlen(args);
3252 if (copy > end - str)
3253 copy = end - str;
3254 memcpy(str, args, copy);
3255 str += len;
3256 args += len + 1;
3257 }
3258 }
3259 if (process)
3260 str = pointer(fmt, str, end, get_arg(void *), spec);
3261
3262 while (isalnum(*fmt))
3263 fmt++;
3264 break;
3265 }
3266
3267 case FORMAT_TYPE_PERCENT_CHAR:
3268 if (str < end)
3269 *str = '%';
3270 ++str;
3271 break;
3272
3273 case FORMAT_TYPE_INVALID:
3274 goto out;
3275
3276 default: {
3277 unsigned long long num;
3278
3279 switch (spec.type) {
3280
3281 case FORMAT_TYPE_LONG_LONG:
3282 num = get_arg(long long);
3283 break;
3284 case FORMAT_TYPE_ULONG:
3285 case FORMAT_TYPE_LONG:
3286 num = get_arg(unsigned long);
3287 break;
3288 case FORMAT_TYPE_SIZE_T:
3289 num = get_arg(size_t);
3290 break;
3291 case FORMAT_TYPE_PTRDIFF:
3292 num = get_arg(ptrdiff_t);
3293 break;
3294 case FORMAT_TYPE_UBYTE:
3295 num = get_arg(unsigned char);
3296 break;
3297 case FORMAT_TYPE_BYTE:
3298 num = get_arg(signed char);
3299 break;
3300 case FORMAT_TYPE_USHORT:
3301 num = get_arg(unsigned short);
3302 break;
3303 case FORMAT_TYPE_SHORT:
3304 num = get_arg(short);
3305 break;
3306 case FORMAT_TYPE_UINT:
3307 num = get_arg(unsigned int);
3308 break;
3309 default:
3310 num = get_arg(int);
3311 }
3312
3313 str = number(str, end, num, spec);
3314 } /* default: */
3315 } /* switch(spec.type) */
3316 } /* while(*fmt) */
3317
3318 out:
3319 if (size > 0) {
3320 if (str < end)
3321 *str = '\0';
3322 else
3323 end[-1] = '\0';
3324 }
3325
3326 #undef get_arg
3327
3328 /* the trailing null byte doesn't count towards the total */
3329 return str - buf;
3330 }
3331 EXPORT_SYMBOL_GPL(bstr_printf);
3332
3333 /**
3334 * bprintf - Parse a format string and place args' binary value in a buffer
3335 * @bin_buf: The buffer to place args' binary value
3336 * @size: The size of the buffer(by words(32bits), not characters)
3337 * @fmt: The format string to use
3338 * @...: Arguments for the format string
3339 *
3340 * The function returns the number of words(u32) written
3341 * into @bin_buf.
3342 */
3343 int bprintf(u32 *bin_buf, size_t size, const char *fmt, ...)
3344 {
3345 va_list args;
3346 int ret;
3347
3348 va_start(args, fmt);
3349 ret = vbin_printf(bin_buf, size, fmt, args);
3350 va_end(args);
3351
3352 return ret;
3353 }
3354 EXPORT_SYMBOL_GPL(bprintf);
3355
3356 #endif /* CONFIG_BINARY_PRINTF */
3357
3358 /**
3359 * vsscanf - Unformat a buffer into a list of arguments
3360 * @buf: input buffer
3361 * @fmt: format of buffer
3362 * @args: arguments
3363 */
3364 int vsscanf(const char *buf, const char *fmt, va_list args)
3365 {
3366 const char *str = buf;
3367 char *next;
3368 char digit;
3369 int num = 0;
3370 u8 qualifier;
3371 unsigned int base;
3372 union {
3373 long long s;
3374 unsigned long long u;
3375 } val;
3376 s16 field_width;
3377 bool is_sign;
3378
3379 while (*fmt) {
3380 /* skip any white space in format */
3381 /* white space in format matchs any amount of
3382 * white space, including none, in the input.
3383 */
3384 if (isspace(*fmt)) {
3385 fmt = skip_spaces(++fmt);
3386 str = skip_spaces(str);
3387 }
3388
3389 /* anything that is not a conversion must match exactly */
3390 if (*fmt != '%' && *fmt) {
3391 if (*fmt++ != *str++)
3392 break;
3393 continue;
3394 }
3395
3396 if (!*fmt)
3397 break;
3398 ++fmt;
3399
3400 /* skip this conversion.
3401 * advance both strings to next white space
3402 */
3403 if (*fmt == '*') {
3404 if (!*str)
3405 break;
3406 while (!isspace(*fmt) && *fmt != '%' && *fmt) {
3407 /* '%*[' not yet supported, invalid format */
3408 if (*fmt == '[')
3409 return num;
3410 fmt++;
3411 }
3412 while (!isspace(*str) && *str)
3413 str++;
3414 continue;
3415 }
3416
3417 /* get field width */
3418 field_width = -1;
3419 if (isdigit(*fmt)) {
3420 field_width = skip_atoi(&fmt);
3421 if (field_width <= 0)
3422 break;
3423 }
3424
3425 /* get conversion qualifier */
3426 qualifier = -1;
3427 if (*fmt == 'h' || _tolower(*fmt) == 'l' ||
3428 *fmt == 'z') {
3429 qualifier = *fmt++;
3430 if (unlikely(qualifier == *fmt)) {
3431 if (qualifier == 'h') {
3432 qualifier = 'H';
3433 fmt++;
3434 } else if (qualifier == 'l') {
3435 qualifier = 'L';
3436 fmt++;
3437 }
3438 }
3439 }
3440
3441 if (!*fmt)
3442 break;
3443
3444 if (*fmt == 'n') {
3445 /* return number of characters read so far */
3446 *va_arg(args, int *) = str - buf;
3447 ++fmt;
3448 continue;
3449 }
3450
3451 if (!*str)
3452 break;
3453
3454 base = 10;
3455 is_sign = false;
3456
3457 switch (*fmt++) {
3458 case 'c':
3459 {
3460 char *s = (char *)va_arg(args, char*);
3461 if (field_width == -1)
3462 field_width = 1;
3463 do {
3464 *s++ = *str++;
3465 } while (--field_width > 0 && *str);
3466 num++;
3467 }
3468 continue;
3469 case 's':
3470 {
3471 char *s = (char *)va_arg(args, char *);
3472 if (field_width == -1)
3473 field_width = SHRT_MAX;
3474 /* first, skip leading white space in buffer */
3475 str = skip_spaces(str);
3476
3477 /* now copy until next white space */
3478 while (*str && !isspace(*str) && field_width--)
3479 *s++ = *str++;
3480 *s = '\0';
3481 num++;
3482 }
3483 continue;
3484 /*
3485 * Warning: This implementation of the '[' conversion specifier
3486 * deviates from its glibc counterpart in the following ways:
3487 * (1) It does NOT support ranges i.e. '-' is NOT a special
3488 * character
3489 * (2) It cannot match the closing bracket ']' itself
3490 * (3) A field width is required
3491 * (4) '%*[' (discard matching input) is currently not supported
3492 *
3493 * Example usage:
3494 * ret = sscanf("00:0a:95","%2[^:]:%2[^:]:%2[^:]",
3495 * buf1, buf2, buf3);
3496 * if (ret < 3)
3497 * // etc..
3498 */
3499 case '[':
3500 {
3501 char *s = (char *)va_arg(args, char *);
3502 DECLARE_BITMAP(set, 256) = {0};
3503 unsigned int len = 0;
3504 bool negate = (*fmt == '^');
3505
3506 /* field width is required */
3507 if (field_width == -1)
3508 return num;
3509
3510 if (negate)
3511 ++fmt;
3512
3513 for ( ; *fmt && *fmt != ']'; ++fmt, ++len)
3514 set_bit((u8)*fmt, set);
3515
3516 /* no ']' or no character set found */
3517 if (!*fmt || !len)
3518 return num;
3519 ++fmt;
3520
3521 if (negate) {
3522 bitmap_complement(set, set, 256);
3523 /* exclude null '\0' byte */
3524 clear_bit(0, set);
3525 }
3526
3527 /* match must be non-empty */
3528 if (!test_bit((u8)*str, set))
3529 return num;
3530
3531 while (test_bit((u8)*str, set) && field_width--)
3532 *s++ = *str++;
3533 *s = '\0';
3534 ++num;
3535 }
3536 continue;
3537 case 'o':
3538 base = 8;
3539 break;
3540 case 'x':
3541 case 'X':
3542 base = 16;
3543 break;
3544 case 'i':
3545 base = 0;
3546 fallthrough;
3547 case 'd':
3548 is_sign = true;
3549 fallthrough;
3550 case 'u':
3551 break;
3552 case '%':
3553 /* looking for '%' in str */
3554 if (*str++ != '%')
3555 return num;
3556 continue;
3557 default:
3558 /* invalid format; stop here */
3559 return num;
3560 }
3561
3562 /* have some sort of integer conversion.
3563 * first, skip white space in buffer.
3564 */
3565 str = skip_spaces(str);
3566
3567 digit = *str;
3568 if (is_sign && digit == '-')
3569 digit = *(str + 1);
3570
3571 if (!digit
3572 || (base == 16 && !isxdigit(digit))
3573 || (base == 10 && !isdigit(digit))
3574 || (base == 8 && (!isdigit(digit) || digit > '7'))
3575 || (base == 0 && !isdigit(digit)))
3576 break;
3577
3578 if (is_sign)
3579 val.s = qualifier != 'L' ?
3580 simple_strtol(str, &next, base) :
3581 simple_strtoll(str, &next, base);
3582 else
3583 val.u = qualifier != 'L' ?
3584 simple_strtoul(str, &next, base) :
3585 simple_strtoull(str, &next, base);
3586
3587 if (field_width > 0 && next - str > field_width) {
3588 if (base == 0)
3589 _parse_integer_fixup_radix(str, &base);
3590 while (next - str > field_width) {
3591 if (is_sign)
3592 val.s = div_s64(val.s, base);
3593 else
3594 val.u = div_u64(val.u, base);
3595 --next;
3596 }
3597 }
3598
3599 switch (qualifier) {
3600 case 'H': /* that's 'hh' in format */
3601 if (is_sign)
3602 *va_arg(args, signed char *) = val.s;
3603 else
3604 *va_arg(args, unsigned char *) = val.u;
3605 break;
3606 case 'h':
3607 if (is_sign)
3608 *va_arg(args, short *) = val.s;
3609 else
3610 *va_arg(args, unsigned short *) = val.u;
3611 break;
3612 case 'l':
3613 if (is_sign)
3614 *va_arg(args, long *) = val.s;
3615 else
3616 *va_arg(args, unsigned long *) = val.u;
3617 break;
3618 case 'L':
3619 if (is_sign)
3620 *va_arg(args, long long *) = val.s;
3621 else
3622 *va_arg(args, unsigned long long *) = val.u;
3623 break;
3624 case 'z':
3625 *va_arg(args, size_t *) = val.u;
3626 break;
3627 default:
3628 if (is_sign)
3629 *va_arg(args, int *) = val.s;
3630 else
3631 *va_arg(args, unsigned int *) = val.u;
3632 break;
3633 }
3634 num++;
3635
3636 if (!next)
3637 break;
3638 str = next;
3639 }
3640
3641 return num;
3642 }
3643 EXPORT_SYMBOL(vsscanf);
3644
3645 /**
3646 * sscanf - Unformat a buffer into a list of arguments
3647 * @buf: input buffer
3648 * @fmt: formatting of buffer
3649 * @...: resulting arguments
3650 */
3651 int sscanf(const char *buf, const char *fmt, ...)
3652 {
3653 va_list args;
3654 int i;
3655
3656 va_start(args, fmt);
3657 i = vsscanf(buf, fmt, args);
3658 va_end(args);
3659
3660 return i;
3661 }
3662 EXPORT_SYMBOL(sscanf);
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