projects/linux·blob v5.15 · refs

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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 <[email protected]>
15 * - changed to provide snprintf and vsnprintf functions
16 * So Feb 1 16:51:32 CET 2004 Juergen Quade <[email protected]>
17 * - scnprintf and vscnprintf
18 */
19
20#include <linux/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
56static unsigned long long simple_strntoull(const char *startp, size_t max_chars,
57 char **endp, unsigned int base)
58{
59 const char *cp;
60 unsigned long long result = 0ULL;
61 size_t prefix_chars;
62 unsigned int rv;
63
64 cp = _parse_integer_fixup_radix(startp, &base);
65 prefix_chars = cp - startp;
66 if (prefix_chars < max_chars) {
67 rv = _parse_integer_limit(cp, base, &result, max_chars - prefix_chars);
68 /* FIXME */
69 cp += (rv & ~KSTRTOX_OVERFLOW);
70 } else {
71 /* Field too short for prefix + digit, skip over without converting */
72 cp = startp + max_chars;
73 }
74
75 if (endp)
76 *endp = (char *)cp;
77
78 return result;
79}
80
81/**
82 * simple_strtoull - convert a string to an unsigned long long
83 * @cp: The start of the string
84 * @endp: A pointer to the end of the parsed string will be placed here
85 * @base: The number base to use
86 *
87 * This function has caveats. Please use kstrtoull instead.
88 */
89noinline
90unsigned long long simple_strtoull(const char *cp, char **endp, unsigned int base)
91{
92 return simple_strntoull(cp, INT_MAX, endp, base);
93}
94EXPORT_SYMBOL(simple_strtoull);
95
96/**
97 * simple_strtoul - convert a string to an unsigned long
98 * @cp: The start of the string
99 * @endp: A pointer to the end of the parsed string will be placed here
100 * @base: The number base to use
101 *
102 * This function has caveats. Please use kstrtoul instead.
103 */
104unsigned long simple_strtoul(const char *cp, char **endp, unsigned int base)
105{
106 return simple_strtoull(cp, endp, base);
107}
108EXPORT_SYMBOL(simple_strtoul);
109
110/**
111 * simple_strtol - convert a string to a signed long
112 * @cp: The start of the string
113 * @endp: A pointer to the end of the parsed string will be placed here
114 * @base: The number base to use
115 *
116 * This function has caveats. Please use kstrtol instead.
117 */
118long simple_strtol(const char *cp, char **endp, unsigned int base)
119{
120 if (*cp == '-')
121 return -simple_strtoul(cp + 1, endp, base);
122
123 return simple_strtoul(cp, endp, base);
124}
125EXPORT_SYMBOL(simple_strtol);
126
127static long long simple_strntoll(const char *cp, size_t max_chars, char **endp,
128 unsigned int base)
129{
130 /*
131 * simple_strntoull() safely handles receiving max_chars==0 in the
132 * case cp[0] == '-' && max_chars == 1.
133 * If max_chars == 0 we can drop through and pass it to simple_strntoull()
134 * and the content of *cp is irrelevant.
135 */
136 if (*cp == '-' && max_chars > 0)
137 return -simple_strntoull(cp + 1, max_chars - 1, endp, base);
138
139 return simple_strntoull(cp, max_chars, endp, base);
140}
141
142/**
143 * simple_strtoll - convert a string to a signed long long
144 * @cp: The start of the string
145 * @endp: A pointer to the end of the parsed string will be placed here
146 * @base: The number base to use
147 *
148 * This function has caveats. Please use kstrtoll instead.
149 */
150long long simple_strtoll(const char *cp, char **endp, unsigned int base)
151{
152 return simple_strntoll(cp, INT_MAX, endp, base);
153}
154EXPORT_SYMBOL(simple_strtoll);
155
156static noinline_for_stack
157int skip_atoi(const char **s)
158{
159 int i = 0;
160
161 do {
162 i = i*10 + *((*s)++) - '0';
163 } while (isdigit(**s));
164
165 return i;
166}
167
168/*
169 * Decimal conversion is by far the most typical, and is used for
170 * /proc and /sys data. This directly impacts e.g. top performance
171 * with many processes running. We optimize it for speed by emitting
172 * two characters at a time, using a 200 byte lookup table. This
173 * roughly halves the number of multiplications compared to computing
174 * the digits one at a time. Implementation strongly inspired by the
175 * previous version, which in turn used ideas described at
176 * <http://www.cs.uiowa.edu/~jones/bcd/divide.html> (with permission
177 * from the author, Douglas W. Jones).
178 *
179 * It turns out there is precisely one 26 bit fixed-point
180 * approximation a of 64/100 for which x/100 == (x * (u64)a) >> 32
181 * holds for all x in [0, 10^8-1], namely a = 0x28f5c29. The actual
182 * range happens to be somewhat larger (x <= 1073741898), but that's
183 * irrelevant for our purpose.
184 *
185 * For dividing a number in the range [10^4, 10^6-1] by 100, we still
186 * need a 32x32->64 bit multiply, so we simply use the same constant.
187 *
188 * For dividing a number in the range [100, 10^4-1] by 100, there are
189 * several options. The simplest is (x * 0x147b) >> 19, which is valid
190 * for all x <= 43698.
191 */
192
193static const u16 decpair[100] = {
194#define _(x) (__force u16) cpu_to_le16(((x % 10) | ((x / 10) << 8)) + 0x3030)
195 _( 0), _( 1), _( 2), _( 3), _( 4), _( 5), _( 6), _( 7), _( 8), _( 9),
196 _(10), _(11), _(12), _(13), _(14), _(15), _(16), _(17), _(18), _(19),
197 _(20), _(21), _(22), _(23), _(24), _(25), _(26), _(27), _(28), _(29),
198 _(30), _(31), _(32), _(33), _(34), _(35), _(36), _(37), _(38), _(39),
199 _(40), _(41), _(42), _(43), _(44), _(45), _(46), _(47), _(48), _(49),
200 _(50), _(51), _(52), _(53), _(54), _(55), _(56), _(57), _(58), _(59),
201 _(60), _(61), _(62), _(63), _(64), _(65), _(66), _(67), _(68), _(69),
202 _(70), _(71), _(72), _(73), _(74), _(75), _(76), _(77), _(78), _(79),
203 _(80), _(81), _(82), _(83), _(84), _(85), _(86), _(87), _(88), _(89),
204 _(90), _(91), _(92), _(93), _(94), _(95), _(96), _(97), _(98), _(99),
205#undef _
206};
207
208/*
209 * This will print a single '0' even if r == 0, since we would
210 * immediately jump to out_r where two 0s would be written but only
211 * one of them accounted for in buf. This is needed by ip4_string
212 * below. All other callers pass a non-zero value of r.
213*/
214static noinline_for_stack
215char *put_dec_trunc8(char *buf, unsigned r)
216{
217 unsigned q;
218
219 /* 1 <= r < 10^8 */
220 if (r < 100)
221 goto out_r;
222
223 /* 100 <= r < 10^8 */
224 q = (r * (u64)0x28f5c29) >> 32;
225 *((u16 *)buf) = decpair[r - 100*q];
226 buf += 2;
227
228 /* 1 <= q < 10^6 */
229 if (q < 100)
230 goto out_q;
231
232 /* 100 <= q < 10^6 */
233 r = (q * (u64)0x28f5c29) >> 32;
234 *((u16 *)buf) = decpair[q - 100*r];
235 buf += 2;
236
237 /* 1 <= r < 10^4 */
238 if (r < 100)
239 goto out_r;
240
241 /* 100 <= r < 10^4 */
242 q = (r * 0x147b) >> 19;
243 *((u16 *)buf) = decpair[r - 100*q];
244 buf += 2;
245out_q:
246 /* 1 <= q < 100 */
247 r = q;
248out_r:
249 /* 1 <= r < 100 */
250 *((u16 *)buf) = decpair[r];
251 buf += r < 10 ? 1 : 2;
252 return buf;
253}
254
255#if BITS_PER_LONG == 64 && BITS_PER_LONG_LONG == 64
256static noinline_for_stack
257char *put_dec_full8(char *buf, unsigned r)
258{
259 unsigned q;
260
261 /* 0 <= r < 10^8 */
262 q = (r * (u64)0x28f5c29) >> 32;
263 *((u16 *)buf) = decpair[r - 100*q];
264 buf += 2;
265
266 /* 0 <= q < 10^6 */
267 r = (q * (u64)0x28f5c29) >> 32;
268 *((u16 *)buf) = decpair[q - 100*r];
269 buf += 2;
270
271 /* 0 <= r < 10^4 */
272 q = (r * 0x147b) >> 19;
273 *((u16 *)buf) = decpair[r - 100*q];
274 buf += 2;
275
276 /* 0 <= q < 100 */
277 *((u16 *)buf) = decpair[q];
278 buf += 2;
279 return buf;
280}
281
282static noinline_for_stack
283char *put_dec(char *buf, unsigned long long n)
284{
285 if (n >= 100*1000*1000)
286 buf = put_dec_full8(buf, do_div(n, 100*1000*1000));
287 /* 1 <= n <= 1.6e11 */
288 if (n >= 100*1000*1000)
289 buf = put_dec_full8(buf, do_div(n, 100*1000*1000));
290 /* 1 <= n < 1e8 */
291 return put_dec_trunc8(buf, n);
292}
293
294#elif BITS_PER_LONG == 32 && BITS_PER_LONG_LONG == 64
295
296static void
297put_dec_full4(char *buf, unsigned r)
298{
299 unsigned q;
300
301 /* 0 <= r < 10^4 */
302 q = (r * 0x147b) >> 19;
303 *((u16 *)buf) = decpair[r - 100*q];
304 buf += 2;
305 /* 0 <= q < 100 */
306 *((u16 *)buf) = decpair[q];
307}
308
309/*
310 * Call put_dec_full4 on x % 10000, return x / 10000.
311 * The approximation x/10000 == (x * 0x346DC5D7) >> 43
312 * holds for all x < 1,128,869,999. The largest value this
313 * helper will ever be asked to convert is 1,125,520,955.
314 * (second call in the put_dec code, assuming n is all-ones).
315 */
316static noinline_for_stack
317unsigned put_dec_helper4(char *buf, unsigned x)
318{
319 uint32_t q = (x * (uint64_t)0x346DC5D7) >> 43;
320
321 put_dec_full4(buf, x - q * 10000);
322 return q;
323}
324
325/* Based on code by Douglas W. Jones found at
326 * <http://www.cs.uiowa.edu/~jones/bcd/decimal.html#sixtyfour>
327 * (with permission from the author).
328 * Performs no 64-bit division and hence should be fast on 32-bit machines.
329 */
330static
331char *put_dec(char *buf, unsigned long long n)
332{
333 uint32_t d3, d2, d1, q, h;
334
335 if (n < 100*1000*1000)
336 return put_dec_trunc8(buf, n);
337
338 d1 = ((uint32_t)n >> 16); /* implicit "& 0xffff" */
339 h = (n >> 32);
340 d2 = (h ) & 0xffff;
341 d3 = (h >> 16); /* implicit "& 0xffff" */
342
343 /* n = 2^48 d3 + 2^32 d2 + 2^16 d1 + d0
344 = 281_4749_7671_0656 d3 + 42_9496_7296 d2 + 6_5536 d1 + d0 */
345 q = 656 * d3 + 7296 * d2 + 5536 * d1 + ((uint32_t)n & 0xffff);
346 q = put_dec_helper4(buf, q);
347
348 q += 7671 * d3 + 9496 * d2 + 6 * d1;
349 q = put_dec_helper4(buf+4, q);
350
351 q += 4749 * d3 + 42 * d2;
352 q = put_dec_helper4(buf+8, q);
353
354 q += 281 * d3;
355 buf += 12;
356 if (q)
357 buf = put_dec_trunc8(buf, q);
358 else while (buf[-1] == '0')
359 --buf;
360
361 return buf;
362}
363
364#endif
365
366/*
367 * Convert passed number to decimal string.
368 * Returns the length of string. On buffer overflow, returns 0.
369 *
370 * If speed is not important, use snprintf(). It's easy to read the code.
371 */
372int num_to_str(char *buf, int size, unsigned long long num, unsigned int width)
373{
374 /* put_dec requires 2-byte alignment of the buffer. */
375 char tmp[sizeof(num) * 3] __aligned(2);
376 int idx, len;
377
378 /* put_dec() may work incorrectly for num = 0 (generate "", not "0") */
379 if (num <= 9) {
380 tmp[0] = '0' + num;
381 len = 1;
382 } else {
383 len = put_dec(tmp, num) - tmp;
384 }
385
386 if (len > size || width > size)
387 return 0;
388
389 if (width > len) {
390 width = width - len;
391 for (idx = 0; idx < width; idx++)
392 buf[idx] = ' ';
393 } else {
394 width = 0;
395 }
396
397 for (idx = 0; idx < len; ++idx)
398 buf[idx + width] = tmp[len - idx - 1];
399
400 return len + width;
401}
402
403#define SIGN 1 /* unsigned/signed, must be 1 */
404#define LEFT 2 /* left justified */
405#define PLUS 4 /* show plus */
406#define SPACE 8 /* space if plus */
407#define ZEROPAD 16 /* pad with zero, must be 16 == '0' - ' ' */
408#define SMALL 32 /* use lowercase in hex (must be 32 == 0x20) */
409#define SPECIAL 64 /* prefix hex with "0x", octal with "0" */
410
411static_assert(ZEROPAD == ('0' - ' '));
412static_assert(SMALL == ' ');
413
414enum format_type {
415 FORMAT_TYPE_NONE, /* Just a string part */
416 FORMAT_TYPE_WIDTH,
417 FORMAT_TYPE_PRECISION,
418 FORMAT_TYPE_CHAR,
419 FORMAT_TYPE_STR,
420 FORMAT_TYPE_PTR,
421 FORMAT_TYPE_PERCENT_CHAR,
422 FORMAT_TYPE_INVALID,
423 FORMAT_TYPE_LONG_LONG,
424 FORMAT_TYPE_ULONG,
425 FORMAT_TYPE_LONG,
426 FORMAT_TYPE_UBYTE,
427 FORMAT_TYPE_BYTE,
428 FORMAT_TYPE_USHORT,
429 FORMAT_TYPE_SHORT,
430 FORMAT_TYPE_UINT,
431 FORMAT_TYPE_INT,
432 FORMAT_TYPE_SIZE_T,
433 FORMAT_TYPE_PTRDIFF
434};
435
436struct printf_spec {
437 unsigned int type:8; /* format_type enum */
438 signed int field_width:24; /* width of output field */
439 unsigned int flags:8; /* flags to number() */
440 unsigned int base:8; /* number base, 8, 10 or 16 only */
441 signed int precision:16; /* # of digits/chars */
442} __packed;
443static_assert(sizeof(struct printf_spec) == 8);
444
445#define FIELD_WIDTH_MAX ((1 << 23) - 1)
446#define PRECISION_MAX ((1 << 15) - 1)
447
448static noinline_for_stack
449char *number(char *buf, char *end, unsigned long long num,
450 struct printf_spec spec)
451{
452 /* put_dec requires 2-byte alignment of the buffer. */
453 char tmp[3 * sizeof(num)] __aligned(2);
454 char sign;
455 char locase;
456 int need_pfx = ((spec.flags & SPECIAL) && spec.base != 10);
457 int i;
458 bool is_zero = num == 0LL;
459 int field_width = spec.field_width;
460 int precision = spec.precision;
461
462 /* locase = 0 or 0x20. ORing digits or letters with 'locase'
463 * produces same digits or (maybe lowercased) letters */
464 locase = (spec.flags & SMALL);
465 if (spec.flags & LEFT)
466 spec.flags &= ~ZEROPAD;
467 sign = 0;
468 if (spec.flags & SIGN) {
469 if ((signed long long)num < 0) {
470 sign = '-';
471 num = -(signed long long)num;
472 field_width--;
473 } else if (spec.flags & PLUS) {
474 sign = '+';
475 field_width--;
476 } else if (spec.flags & SPACE) {
477 sign = ' ';
478 field_width--;
479 }
480 }
481 if (need_pfx) {
482 if (spec.base == 16)
483 field_width -= 2;
484 else if (!is_zero)
485 field_width--;
486 }
487
488 /* generate full string in tmp[], in reverse order */
489 i = 0;
490 if (num < spec.base)
491 tmp[i++] = hex_asc_upper[num] | locase;
492 else if (spec.base != 10) { /* 8 or 16 */
493 int mask = spec.base - 1;
494 int shift = 3;
495
496 if (spec.base == 16)
497 shift = 4;
498 do {
499 tmp[i++] = (hex_asc_upper[((unsigned char)num) & mask] | locase);
500 num >>= shift;
501 } while (num);
502 } else { /* base 10 */
503 i = put_dec(tmp, num) - tmp;
504 }
505
506 /* printing 100 using %2d gives "100", not "00" */
507 if (i > precision)
508 precision = i;
509 /* leading space padding */
510 field_width -= precision;
511 if (!(spec.flags & (ZEROPAD | LEFT))) {
512 while (--field_width >= 0) {
513 if (buf < end)
514 *buf = ' ';
515 ++buf;
516 }
517 }
518 /* sign */
519 if (sign) {
520 if (buf < end)
521 *buf = sign;
522 ++buf;
523 }
524 /* "0x" / "0" prefix */
525 if (need_pfx) {
526 if (spec.base == 16 || !is_zero) {
527 if (buf < end)
528 *buf = '0';
529 ++buf;
530 }
531 if (spec.base == 16) {
532 if (buf < end)
533 *buf = ('X' | locase);
534 ++buf;
535 }
536 }
537 /* zero or space padding */
538 if (!(spec.flags & LEFT)) {
539 char c = ' ' + (spec.flags & ZEROPAD);
540
541 while (--field_width >= 0) {
542 if (buf < end)
543 *buf = c;
544 ++buf;
545 }
546 }
547 /* hmm even more zero padding? */
548 while (i <= --precision) {
549 if (buf < end)
550 *buf = '0';
551 ++buf;
552 }
553 /* actual digits of result */
554 while (--i >= 0) {
555 if (buf < end)
556 *buf = tmp[i];
557 ++buf;
558 }
559 /* trailing space padding */
560 while (--field_width >= 0) {
561 if (buf < end)
562 *buf = ' ';
563 ++buf;
564 }
565
566 return buf;
567}
568
569static noinline_for_stack
570char *special_hex_number(char *buf, char *end, unsigned long long num, int size)
571{
572 struct printf_spec spec;
573
574 spec.type = FORMAT_TYPE_PTR;
575 spec.field_width = 2 + 2 * size; /* 0x + hex */
576 spec.flags = SPECIAL | SMALL | ZEROPAD;
577 spec.base = 16;
578 spec.precision = -1;
579
580 return number(buf, end, num, spec);
581}
582
583static void move_right(char *buf, char *end, unsigned len, unsigned spaces)
584{
585 size_t size;
586 if (buf >= end) /* nowhere to put anything */
587 return;
588 size = end - buf;
589 if (size <= spaces) {
590 memset(buf, ' ', size);
591 return;
592 }
593 if (len) {
594 if (len > size - spaces)
595 len = size - spaces;
596 memmove(buf + spaces, buf, len);
597 }
598 memset(buf, ' ', spaces);
599}
600
601/*
602 * Handle field width padding for a string.
603 * @buf: current buffer position
604 * @n: length of string
605 * @end: end of output buffer
606 * @spec: for field width and flags
607 * Returns: new buffer position after padding.
608 */
609static noinline_for_stack
610char *widen_string(char *buf, int n, char *end, struct printf_spec spec)
611{
612 unsigned spaces;
613
614 if (likely(n >= spec.field_width))
615 return buf;
616 /* we want to pad the sucker */
617 spaces = spec.field_width - n;
618 if (!(spec.flags & LEFT)) {
619 move_right(buf - n, end, n, spaces);
620 return buf + spaces;
621 }
622 while (spaces--) {
623 if (buf < end)
624 *buf = ' ';
625 ++buf;
626 }
627 return buf;
628}
629
630/* Handle string from a well known address. */
631static char *string_nocheck(char *buf, char *end, const char *s,
632 struct printf_spec spec)
633{
634 int len = 0;
635 int lim = spec.precision;
636
637 while (lim--) {
638 char c = *s++;
639 if (!c)
640 break;
641 if (buf < end)
642 *buf = c;
643 ++buf;
644 ++len;
645 }
646 return widen_string(buf, len, end, spec);
647}
648
649static char *err_ptr(char *buf, char *end, void *ptr,
650 struct printf_spec spec)
651{
652 int err = PTR_ERR(ptr);
653 const char *sym = errname(err);
654
655 if (sym)
656 return string_nocheck(buf, end, sym, spec);
657
658 /*
659 * Somebody passed ERR_PTR(-1234) or some other non-existing
660 * Efoo - or perhaps CONFIG_SYMBOLIC_ERRNAME=n. Fall back to
661 * printing it as its decimal representation.
662 */
663 spec.flags |= SIGN;
664 spec.base = 10;
665 return number(buf, end, err, spec);
666}
667
668/* Be careful: error messages must fit into the given buffer. */
669static char *error_string(char *buf, char *end, const char *s,
670 struct printf_spec spec)
671{
672 /*
673 * Hard limit to avoid a completely insane messages. It actually
674 * works pretty well because most error messages are in
675 * the many pointer format modifiers.
676 */
677 if (spec.precision == -1)
678 spec.precision = 2 * sizeof(void *);
679
680 return string_nocheck(buf, end, s, spec);
681}
682
683/*
684 * Do not call any complex external code here. Nested printk()/vsprintf()
685 * might cause infinite loops. Failures might break printk() and would
686 * be hard to debug.
687 */
688static const char *check_pointer_msg(const void *ptr)
689{
690 if (!ptr)
691 return "(null)";
692
693 if ((unsigned long)ptr < PAGE_SIZE || IS_ERR_VALUE(ptr))
694 return "(efault)";
695
696 return NULL;
697}
698
699static int check_pointer(char **buf, char *end, const void *ptr,
700 struct printf_spec spec)
701{
702 const char *err_msg;
703
704 err_msg = check_pointer_msg(ptr);
705 if (err_msg) {
706 *buf = error_string(*buf, end, err_msg, spec);
707 return -EFAULT;
708 }
709
710 return 0;
711}
712
713static noinline_for_stack
714char *string(char *buf, char *end, const char *s,
715 struct printf_spec spec)
716{
717 if (check_pointer(&buf, end, s, spec))
718 return buf;
719
720 return string_nocheck(buf, end, s, spec);
721}
722
723static char *pointer_string(char *buf, char *end,
724 const void *ptr,
725 struct printf_spec spec)
726{
727 spec.base = 16;
728 spec.flags |= SMALL;
729 if (spec.field_width == -1) {
730 spec.field_width = 2 * sizeof(ptr);
731 spec.flags |= ZEROPAD;
732 }
733
734 return number(buf, end, (unsigned long int)ptr, spec);
735}
736
737/* Make pointers available for printing early in the boot sequence. */
738static int debug_boot_weak_hash __ro_after_init;
739
740static int __init debug_boot_weak_hash_enable(char *str)
741{
742 debug_boot_weak_hash = 1;
743 pr_info("debug_boot_weak_hash enabled\n");
744 return 0;
745}
746early_param("debug_boot_weak_hash", debug_boot_weak_hash_enable);
747
748static DEFINE_STATIC_KEY_TRUE(not_filled_random_ptr_key);
749static siphash_key_t ptr_key __read_mostly;
750
751static void enable_ptr_key_workfn(struct work_struct *work)
752{
753 get_random_bytes(&ptr_key, sizeof(ptr_key));
754 /* Needs to run from preemptible context */
755 static_branch_disable(&not_filled_random_ptr_key);
756}
757
758static DECLARE_WORK(enable_ptr_key_work, enable_ptr_key_workfn);
759
760static void fill_random_ptr_key(struct random_ready_callback *unused)
761{
762 /* This may be in an interrupt handler. */
763 queue_work(system_unbound_wq, &enable_ptr_key_work);
764}
765
766static struct random_ready_callback random_ready = {
767 .func = fill_random_ptr_key
768};
769
770static int __init initialize_ptr_random(void)
771{
772 int key_size = sizeof(ptr_key);
773 int ret;
774
775 /* Use hw RNG if available. */
776 if (get_random_bytes_arch(&ptr_key, key_size) == key_size) {
777 static_branch_disable(&not_filled_random_ptr_key);
778 return 0;
779 }
780
781 ret = add_random_ready_callback(&random_ready);
782 if (!ret) {
783 return 0;
784 } else if (ret == -EALREADY) {
785 /* This is in preemptible context */
786 enable_ptr_key_workfn(&enable_ptr_key_work);
787 return 0;
788 }
789
790 return ret;
791}
792early_initcall(initialize_ptr_random);
793
794/* Maps a pointer to a 32 bit unique identifier. */
795static inline int __ptr_to_hashval(const void *ptr, unsigned long *hashval_out)
796{
797 unsigned long hashval;
798
799 if (static_branch_unlikely(&not_filled_random_ptr_key))
800 return -EAGAIN;
801
802#ifdef CONFIG_64BIT
803 hashval = (unsigned long)siphash_1u64((u64)ptr, &ptr_key);
804 /*
805 * Mask off the first 32 bits, this makes explicit that we have
806 * modified the address (and 32 bits is plenty for a unique ID).
807 */
808 hashval = hashval & 0xffffffff;
809#else
810 hashval = (unsigned long)siphash_1u32((u32)ptr, &ptr_key);
811#endif
812 *hashval_out = hashval;
813 return 0;
814}
815
816int ptr_to_hashval(const void *ptr, unsigned long *hashval_out)
817{
818 return __ptr_to_hashval(ptr, hashval_out);
819}
820
821static char *ptr_to_id(char *buf, char *end, const void *ptr,
822 struct printf_spec spec)
823{
824 const char *str = sizeof(ptr) == 8 ? "(____ptrval____)" : "(ptrval)";
825 unsigned long hashval;
826 int ret;
827
828 /*
829 * Print the real pointer value for NULL and error pointers,
830 * as they are not actual addresses.
831 */
832 if (IS_ERR_OR_NULL(ptr))
833 return pointer_string(buf, end, ptr, spec);
834
835 /* When debugging early boot use non-cryptographically secure hash. */
836 if (unlikely(debug_boot_weak_hash)) {
837 hashval = hash_long((unsigned long)ptr, 32);
838 return pointer_string(buf, end, (const void *)hashval, spec);
839 }
840
841 ret = __ptr_to_hashval(ptr, &hashval);
842 if (ret) {
843 spec.field_width = 2 * sizeof(ptr);
844 /* string length must be less than default_width */
845 return error_string(buf, end, str, spec);
846 }
847
848 return pointer_string(buf, end, (const void *)hashval, spec);
849}
850
851int kptr_restrict __read_mostly;
852
853static noinline_for_stack
854char *restricted_pointer(char *buf, char *end, const void *ptr,
855 struct printf_spec spec)
856{
857 switch (kptr_restrict) {
858 case 0:
859 /* Handle as %p, hash and do _not_ leak addresses. */
860 return ptr_to_id(buf, end, ptr, spec);
861 case 1: {
862 const struct cred *cred;
863
864 /*
865 * kptr_restrict==1 cannot be used in IRQ context
866 * because its test for CAP_SYSLOG would be meaningless.
867 */
868 if (in_irq() || in_serving_softirq() || in_nmi()) {
869 if (spec.field_width == -1)
870 spec.field_width = 2 * sizeof(ptr);
871 return error_string(buf, end, "pK-error", spec);
872 }
873
874 /*
875 * Only print the real pointer value if the current
876 * process has CAP_SYSLOG and is running with the
877 * same credentials it started with. This is because
878 * access to files is checked at open() time, but %pK
879 * checks permission at read() time. We don't want to
880 * leak pointer values if a binary opens a file using
881 * %pK and then elevates privileges before reading it.
882 */
883 cred = current_cred();
884 if (!has_capability_noaudit(current, CAP_SYSLOG) ||
885 !uid_eq(cred->euid, cred->uid) ||
886 !gid_eq(cred->egid, cred->gid))
887 ptr = NULL;
888 break;
889 }
890 case 2:
891 default:
892 /* Always print 0's for %pK */
893 ptr = NULL;
894 break;
895 }
896
897 return pointer_string(buf, end, ptr, spec);
898}
899
900static noinline_for_stack
901char *dentry_name(char *buf, char *end, const struct dentry *d, struct printf_spec spec,
902 const char *fmt)
903{
904 const char *array[4], *s;
905 const struct dentry *p;
906 int depth;
907 int i, n;
908
909 switch (fmt[1]) {
910 case '2': case '3': case '4':
911 depth = fmt[1] - '0';
912 break;
913 default:
914 depth = 1;
915 }
916
917 rcu_read_lock();
918 for (i = 0; i < depth; i++, d = p) {
919 if (check_pointer(&buf, end, d, spec)) {
920 rcu_read_unlock();
921 return buf;
922 }
923
924 p = READ_ONCE(d->d_parent);
925 array[i] = READ_ONCE(d->d_name.name);
926 if (p == d) {
927 if (i)
928 array[i] = "";
929 i++;
930 break;
931 }
932 }
933 s = array[--i];
934 for (n = 0; n != spec.precision; n++, buf++) {
935 char c = *s++;
936 if (!c) {
937 if (!i)
938 break;
939 c = '/';
940 s = array[--i];
941 }
942 if (buf < end)
943 *buf = c;
944 }
945 rcu_read_unlock();
946 return widen_string(buf, n, end, spec);
947}
948
949static noinline_for_stack
950char *file_dentry_name(char *buf, char *end, const struct file *f,
951 struct printf_spec spec, const char *fmt)
952{
953 if (check_pointer(&buf, end, f, spec))
954 return buf;
955
956 return dentry_name(buf, end, f->f_path.dentry, spec, fmt);
957}
958#ifdef CONFIG_BLOCK
959static noinline_for_stack
960char *bdev_name(char *buf, char *end, struct block_device *bdev,
961 struct printf_spec spec, const char *fmt)
962{
963 struct gendisk *hd;
964
965 if (check_pointer(&buf, end, bdev, spec))
966 return buf;
967
968 hd = bdev->bd_disk;
969 buf = string(buf, end, hd->disk_name, spec);
970 if (bdev->bd_partno) {
971 if (isdigit(hd->disk_name[strlen(hd->disk_name)-1])) {
972 if (buf < end)
973 *buf = 'p';
974 buf++;
975 }
976 buf = number(buf, end, bdev->bd_partno, spec);
977 }
978 return buf;
979}
980#endif
981
982static noinline_for_stack
983char *symbol_string(char *buf, char *end, void *ptr,
984 struct printf_spec spec, const char *fmt)
985{
986 unsigned long value;
987#ifdef CONFIG_KALLSYMS
988 char sym[KSYM_SYMBOL_LEN];
989#endif
990
991 if (fmt[1] == 'R')
992 ptr = __builtin_extract_return_addr(ptr);
993 value = (unsigned long)ptr;
994
995#ifdef CONFIG_KALLSYMS
996 if (*fmt == 'B' && fmt[1] == 'b')
997 sprint_backtrace_build_id(sym, value);
998 else if (*fmt == 'B')
999 sprint_backtrace(sym, value);
1000 else if (*fmt == 'S' && (fmt[1] == 'b' || (fmt[1] == 'R' && fmt[2] == 'b')))
1001 sprint_symbol_build_id(sym, value);
1002 else if (*fmt != 's')
1003 sprint_symbol(sym, value);
1004 else
1005 sprint_symbol_no_offset(sym, value);
1006
1007 return string_nocheck(buf, end, sym, spec);
1008#else
1009 return special_hex_number(buf, end, value, sizeof(void *));
1010#endif
1011}
1012
1013static const struct printf_spec default_str_spec = {
1014 .field_width = -1,
1015 .precision = -1,
1016};
1017
1018static const struct printf_spec default_flag_spec = {
1019 .base = 16,
1020 .precision = -1,
1021 .flags = SPECIAL | SMALL,
1022};
1023
1024static const struct printf_spec default_dec_spec = {
1025 .base = 10,
1026 .precision = -1,
1027};
1028
1029static const struct printf_spec default_dec02_spec = {
1030 .base = 10,
1031 .field_width = 2,
1032 .precision = -1,
1033 .flags = ZEROPAD,
1034};
1035
1036static const struct printf_spec default_dec04_spec = {
1037 .base = 10,
1038 .field_width = 4,
1039 .precision = -1,
1040 .flags = ZEROPAD,
1041};
1042
1043static noinline_for_stack
1044char *resource_string(char *buf, char *end, struct resource *res,
1045 struct printf_spec spec, const char *fmt)
1046{
1047#ifndef IO_RSRC_PRINTK_SIZE
1048#define IO_RSRC_PRINTK_SIZE 6
1049#endif
1050
1051#ifndef MEM_RSRC_PRINTK_SIZE
1052#define MEM_RSRC_PRINTK_SIZE 10
1053#endif
1054 static const struct printf_spec io_spec = {
1055 .base = 16,
1056 .field_width = IO_RSRC_PRINTK_SIZE,
1057 .precision = -1,
1058 .flags = SPECIAL | SMALL | ZEROPAD,
1059 };
1060 static const struct printf_spec mem_spec = {
1061 .base = 16,
1062 .field_width = MEM_RSRC_PRINTK_SIZE,
1063 .precision = -1,
1064 .flags = SPECIAL | SMALL | ZEROPAD,
1065 };
1066 static const struct printf_spec bus_spec = {
1067 .base = 16,
1068 .field_width = 2,
1069 .precision = -1,
1070 .flags = SMALL | ZEROPAD,
1071 };
1072 static const struct printf_spec str_spec = {
1073 .field_width = -1,
1074 .precision = 10,
1075 .flags = LEFT,
1076 };
1077
1078 /* 32-bit res (sizeof==4): 10 chars in dec, 10 in hex ("0x" + 8)
1079 * 64-bit res (sizeof==8): 20 chars in dec, 18 in hex ("0x" + 16) */
1080#define RSRC_BUF_SIZE ((2 * sizeof(resource_size_t)) + 4)
1081#define FLAG_BUF_SIZE (2 * sizeof(res->flags))
1082#define DECODED_BUF_SIZE sizeof("[mem - 64bit pref window disabled]")
1083#define RAW_BUF_SIZE sizeof("[mem - flags 0x]")
1084 char sym[max(2*RSRC_BUF_SIZE + DECODED_BUF_SIZE,
1085 2*RSRC_BUF_SIZE + FLAG_BUF_SIZE + RAW_BUF_SIZE)];
1086
1087 char *p = sym, *pend = sym + sizeof(sym);
1088 int decode = (fmt[0] == 'R') ? 1 : 0;
1089 const struct printf_spec *specp;
1090
1091 if (check_pointer(&buf, end, res, spec))
1092 return buf;
1093
1094 *p++ = '[';
1095 if (res->flags & IORESOURCE_IO) {
1096 p = string_nocheck(p, pend, "io ", str_spec);
1097 specp = &io_spec;
1098 } else if (res->flags & IORESOURCE_MEM) {
1099 p = string_nocheck(p, pend, "mem ", str_spec);
1100 specp = &mem_spec;
1101 } else if (res->flags & IORESOURCE_IRQ) {
1102 p = string_nocheck(p, pend, "irq ", str_spec);
1103 specp = &default_dec_spec;
1104 } else if (res->flags & IORESOURCE_DMA) {
1105 p = string_nocheck(p, pend, "dma ", str_spec);
1106 specp = &default_dec_spec;
1107 } else if (res->flags & IORESOURCE_BUS) {
1108 p = string_nocheck(p, pend, "bus ", str_spec);
1109 specp = &bus_spec;
1110 } else {
1111 p = string_nocheck(p, pend, "??? ", str_spec);
1112 specp = &mem_spec;
1113 decode = 0;
1114 }
1115 if (decode && res->flags & IORESOURCE_UNSET) {
1116 p = string_nocheck(p, pend, "size ", str_spec);
1117 p = number(p, pend, resource_size(res), *specp);
1118 } else {
1119 p = number(p, pend, res->start, *specp);
1120 if (res->start != res->end) {
1121 *p++ = '-';
1122 p = number(p, pend, res->end, *specp);
1123 }
1124 }
1125 if (decode) {
1126 if (res->flags & IORESOURCE_MEM_64)
1127 p = string_nocheck(p, pend, " 64bit", str_spec);
1128 if (res->flags & IORESOURCE_PREFETCH)
1129 p = string_nocheck(p, pend, " pref", str_spec);
1130 if (res->flags & IORESOURCE_WINDOW)
1131 p = string_nocheck(p, pend, " window", str_spec);
1132 if (res->flags & IORESOURCE_DISABLED)
1133 p = string_nocheck(p, pend, " disabled", str_spec);
1134 } else {
1135 p = string_nocheck(p, pend, " flags ", str_spec);
1136 p = number(p, pend, res->flags, default_flag_spec);
1137 }
1138 *p++ = ']';
1139 *p = '\0';
1140
1141 return string_nocheck(buf, end, sym, spec);
1142}
1143
1144static noinline_for_stack
1145char *hex_string(char *buf, char *end, u8 *addr, struct printf_spec spec,
1146 const char *fmt)
1147{
1148 int i, len = 1; /* if we pass '%ph[CDN]', field width remains
1149 negative value, fallback to the default */
1150 char separator;
1151
1152 if (spec.field_width == 0)
1153 /* nothing to print */
1154 return buf;
1155
1156 if (check_pointer(&buf, end, addr, spec))
1157 return buf;
1158
1159 switch (fmt[1]) {
1160 case 'C':
1161 separator = ':';
1162 break;
1163 case 'D':
1164 separator = '-';
1165 break;
1166 case 'N':
1167 separator = 0;
1168 break;
1169 default:
1170 separator = ' ';
1171 break;
1172 }
1173
1174 if (spec.field_width > 0)
1175 len = min_t(int, spec.field_width, 64);
1176
1177 for (i = 0; i < len; ++i) {
1178 if (buf < end)
1179 *buf = hex_asc_hi(addr[i]);
1180 ++buf;
1181 if (buf < end)
1182 *buf = hex_asc_lo(addr[i]);
1183 ++buf;
1184
1185 if (separator && i != len - 1) {
1186 if (buf < end)
1187 *buf = separator;
1188 ++buf;
1189 }
1190 }
1191
1192 return buf;
1193}
1194
1195static noinline_for_stack
1196char *bitmap_string(char *buf, char *end, unsigned long *bitmap,
1197 struct printf_spec spec, const char *fmt)
1198{
1199 const int CHUNKSZ = 32;
1200 int nr_bits = max_t(int, spec.field_width, 0);
1201 int i, chunksz;
1202 bool first = true;
1203
1204 if (check_pointer(&buf, end, bitmap, spec))
1205 return buf;
1206
1207 /* reused to print numbers */
1208 spec = (struct printf_spec){ .flags = SMALL | ZEROPAD, .base = 16 };
1209
1210 chunksz = nr_bits & (CHUNKSZ - 1);
1211 if (chunksz == 0)
1212 chunksz = CHUNKSZ;
1213
1214 i = ALIGN(nr_bits, CHUNKSZ) - CHUNKSZ;
1215 for (; i >= 0; i -= CHUNKSZ) {
1216 u32 chunkmask, val;
1217 int word, bit;
1218
1219 chunkmask = ((1ULL << chunksz) - 1);
1220 word = i / BITS_PER_LONG;
1221 bit = i % BITS_PER_LONG;
1222 val = (bitmap[word] >> bit) & chunkmask;
1223
1224 if (!first) {
1225 if (buf < end)
1226 *buf = ',';
1227 buf++;
1228 }
1229 first = false;
1230
1231 spec.field_width = DIV_ROUND_UP(chunksz, 4);
1232 buf = number(buf, end, val, spec);
1233
1234 chunksz = CHUNKSZ;
1235 }
1236 return buf;
1237}
1238
1239static noinline_for_stack
1240char *bitmap_list_string(char *buf, char *end, unsigned long *bitmap,
1241 struct printf_spec spec, const char *fmt)
1242{
1243 int nr_bits = max_t(int, spec.field_width, 0);
1244 /* current bit is 'cur', most recently seen range is [rbot, rtop] */
1245 int cur, rbot, rtop;
1246 bool first = true;
1247
1248 if (check_pointer(&buf, end, bitmap, spec))
1249 return buf;
1250
1251 rbot = cur = find_first_bit(bitmap, nr_bits);
1252 while (cur < nr_bits) {
1253 rtop = cur;
1254 cur = find_next_bit(bitmap, nr_bits, cur + 1);
1255 if (cur < nr_bits && cur <= rtop + 1)
1256 continue;
1257
1258 if (!first) {
1259 if (buf < end)
1260 *buf = ',';
1261 buf++;
1262 }
1263 first = false;
1264
1265 buf = number(buf, end, rbot, default_dec_spec);
1266 if (rbot < rtop) {
1267 if (buf < end)
1268 *buf = '-';
1269 buf++;
1270
1271 buf = number(buf, end, rtop, default_dec_spec);
1272 }
1273
1274 rbot = cur;
1275 }
1276 return buf;
1277}
1278
1279static noinline_for_stack
1280char *mac_address_string(char *buf, char *end, u8 *addr,
1281 struct printf_spec spec, const char *fmt)
1282{
1283 char mac_addr[sizeof("xx:xx:xx:xx:xx:xx")];
1284 char *p = mac_addr;
1285 int i;
1286 char separator;
1287 bool reversed = false;
1288
1289 if (check_pointer(&buf, end, addr, spec))
1290 return buf;
1291
1292 switch (fmt[1]) {
1293 case 'F':
1294 separator = '-';
1295 break;
1296
1297 case 'R':
1298 reversed = true;
1299 fallthrough;
1300
1301 default:
1302 separator = ':';
1303 break;
1304 }
1305
1306 for (i = 0; i < 6; i++) {
1307 if (reversed)
1308 p = hex_byte_pack(p, addr[5 - i]);
1309 else
1310 p = hex_byte_pack(p, addr[i]);
1311
1312 if (fmt[0] == 'M' && i != 5)
1313 *p++ = separator;
1314 }
1315 *p = '\0';
1316
1317 return string_nocheck(buf, end, mac_addr, spec);
1318}
1319
1320static noinline_for_stack
1321char *ip4_string(char *p, const u8 *addr, const char *fmt)
1322{
1323 int i;
1324 bool leading_zeros = (fmt[0] == 'i');
1325 int index;
1326 int step;
1327
1328 switch (fmt[2]) {
1329 case 'h':
1330#ifdef __BIG_ENDIAN
1331 index = 0;
1332 step = 1;
1333#else
1334 index = 3;
1335 step = -1;
1336#endif
1337 break;
1338 case 'l':
1339 index = 3;
1340 step = -1;
1341 break;
1342 case 'n':
1343 case 'b':
1344 default:
1345 index = 0;
1346 step = 1;
1347 break;
1348 }
1349 for (i = 0; i < 4; i++) {
1350 char temp[4] __aligned(2); /* hold each IP quad in reverse order */
1351 int digits = put_dec_trunc8(temp, addr[index]) - temp;
1352 if (leading_zeros) {
1353 if (digits < 3)
1354 *p++ = '0';
1355 if (digits < 2)
1356 *p++ = '0';
1357 }
1358 /* reverse the digits in the quad */
1359 while (digits--)
1360 *p++ = temp[digits];
1361 if (i < 3)
1362 *p++ = '.';
1363 index += step;
1364 }
1365 *p = '\0';
1366
1367 return p;
1368}
1369
1370static noinline_for_stack
1371char *ip6_compressed_string(char *p, const char *addr)
1372{
1373 int i, j, range;
1374 unsigned char zerolength[8];
1375 int longest = 1;
1376 int colonpos = -1;
1377 u16 word;
1378 u8 hi, lo;
1379 bool needcolon = false;
1380 bool useIPv4;
1381 struct in6_addr in6;
1382
1383 memcpy(&in6, addr, sizeof(struct in6_addr));
1384
1385 useIPv4 = ipv6_addr_v4mapped(&in6) || ipv6_addr_is_isatap(&in6);
1386
1387 memset(zerolength, 0, sizeof(zerolength));
1388
1389 if (useIPv4)
1390 range = 6;
1391 else
1392 range = 8;
1393
1394 /* find position of longest 0 run */
1395 for (i = 0; i < range; i++) {
1396 for (j = i; j < range; j++) {
1397 if (in6.s6_addr16[j] != 0)
1398 break;
1399 zerolength[i]++;
1400 }
1401 }
1402 for (i = 0; i < range; i++) {
1403 if (zerolength[i] > longest) {
1404 longest = zerolength[i];
1405 colonpos = i;
1406 }
1407 }
1408 if (longest == 1) /* don't compress a single 0 */
1409 colonpos = -1;
1410
1411 /* emit address */
1412 for (i = 0; i < range; i++) {
1413 if (i == colonpos) {
1414 if (needcolon || i == 0)
1415 *p++ = ':';
1416 *p++ = ':';
1417 needcolon = false;
1418 i += longest - 1;
1419 continue;
1420 }
1421 if (needcolon) {
1422 *p++ = ':';
1423 needcolon = false;
1424 }
1425 /* hex u16 without leading 0s */
1426 word = ntohs(in6.s6_addr16[i]);
1427 hi = word >> 8;
1428 lo = word & 0xff;
1429 if (hi) {
1430 if (hi > 0x0f)
1431 p = hex_byte_pack(p, hi);
1432 else
1433 *p++ = hex_asc_lo(hi);
1434 p = hex_byte_pack(p, lo);
1435 }
1436 else if (lo > 0x0f)
1437 p = hex_byte_pack(p, lo);
1438 else
1439 *p++ = hex_asc_lo(lo);
1440 needcolon = true;
1441 }
1442
1443 if (useIPv4) {
1444 if (needcolon)
1445 *p++ = ':';
1446 p = ip4_string(p, &in6.s6_addr[12], "I4");
1447 }
1448 *p = '\0';
1449
1450 return p;
1451}
1452
1453static noinline_for_stack
1454char *ip6_string(char *p, const char *addr, const char *fmt)
1455{
1456 int i;
1457
1458 for (i = 0; i < 8; i++) {
1459 p = hex_byte_pack(p, *addr++);
1460 p = hex_byte_pack(p, *addr++);
1461 if (fmt[0] == 'I' && i != 7)
1462 *p++ = ':';
1463 }
1464 *p = '\0';
1465
1466 return p;
1467}
1468
1469static noinline_for_stack
1470char *ip6_addr_string(char *buf, char *end, const u8 *addr,
1471 struct printf_spec spec, const char *fmt)
1472{
1473 char ip6_addr[sizeof("xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255")];
1474
1475 if (fmt[0] == 'I' && fmt[2] == 'c')
1476 ip6_compressed_string(ip6_addr, addr);
1477 else
1478 ip6_string(ip6_addr, addr, fmt);
1479
1480 return string_nocheck(buf, end, ip6_addr, spec);
1481}
1482
1483static noinline_for_stack
1484char *ip4_addr_string(char *buf, char *end, const u8 *addr,
1485 struct printf_spec spec, const char *fmt)
1486{
1487 char ip4_addr[sizeof("255.255.255.255")];
1488
1489 ip4_string(ip4_addr, addr, fmt);
1490
1491 return string_nocheck(buf, end, ip4_addr, spec);
1492}
1493
1494static noinline_for_stack
1495char *ip6_addr_string_sa(char *buf, char *end, const struct sockaddr_in6 *sa,
1496 struct printf_spec spec, const char *fmt)
1497{
1498 bool have_p = false, have_s = false, have_f = false, have_c = false;
1499 char ip6_addr[sizeof("[xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255]") +
1500 sizeof(":12345") + sizeof("/123456789") +
1501 sizeof("%1234567890")];
1502 char *p = ip6_addr, *pend = ip6_addr + sizeof(ip6_addr);
1503 const u8 *addr = (const u8 *) &sa->sin6_addr;
1504 char fmt6[2] = { fmt[0], '6' };
1505 u8 off = 0;
1506
1507 fmt++;
1508 while (isalpha(*++fmt)) {
1509 switch (*fmt) {
1510 case 'p':
1511 have_p = true;
1512 break;
1513 case 'f':
1514 have_f = true;
1515 break;
1516 case 's':
1517 have_s = true;
1518 break;
1519 case 'c':
1520 have_c = true;
1521 break;
1522 }
1523 }
1524
1525 if (have_p || have_s || have_f) {
1526 *p = '[';
1527 off = 1;
1528 }
1529
1530 if (fmt6[0] == 'I' && have_c)
1531 p = ip6_compressed_string(ip6_addr + off, addr);
1532 else
1533 p = ip6_string(ip6_addr + off, addr, fmt6);
1534
1535 if (have_p || have_s || have_f)
1536 *p++ = ']';
1537
1538 if (have_p) {
1539 *p++ = ':';
1540 p = number(p, pend, ntohs(sa->sin6_port), spec);
1541 }
1542 if (have_f) {
1543 *p++ = '/';
1544 p = number(p, pend, ntohl(sa->sin6_flowinfo &
1545 IPV6_FLOWINFO_MASK), spec);
1546 }
1547 if (have_s) {
1548 *p++ = '%';
1549 p = number(p, pend, sa->sin6_scope_id, spec);
1550 }
1551 *p = '\0';
1552
1553 return string_nocheck(buf, end, ip6_addr, spec);
1554}
1555
1556static noinline_for_stack
1557char *ip4_addr_string_sa(char *buf, char *end, const struct sockaddr_in *sa,
1558 struct printf_spec spec, const char *fmt)
1559{
1560 bool have_p = false;
1561 char *p, ip4_addr[sizeof("255.255.255.255") + sizeof(":12345")];
1562 char *pend = ip4_addr + sizeof(ip4_addr);
1563 const u8 *addr = (const u8 *) &sa->sin_addr.s_addr;
1564 char fmt4[3] = { fmt[0], '4', 0 };
1565
1566 fmt++;
1567 while (isalpha(*++fmt)) {
1568 switch (*fmt) {
1569 case 'p':
1570 have_p = true;
1571 break;
1572 case 'h':
1573 case 'l':
1574 case 'n':
1575 case 'b':
1576 fmt4[2] = *fmt;
1577 break;
1578 }
1579 }
1580
1581 p = ip4_string(ip4_addr, addr, fmt4);
1582 if (have_p) {
1583 *p++ = ':';
1584 p = number(p, pend, ntohs(sa->sin_port), spec);
1585 }
1586 *p = '\0';
1587
1588 return string_nocheck(buf, end, ip4_addr, spec);
1589}
1590
1591static noinline_for_stack
1592char *ip_addr_string(char *buf, char *end, const void *ptr,
1593 struct printf_spec spec, const char *fmt)
1594{
1595 char *err_fmt_msg;
1596
1597 if (check_pointer(&buf, end, ptr, spec))
1598 return buf;
1599
1600 switch (fmt[1]) {
1601 case '6':
1602 return ip6_addr_string(buf, end, ptr, spec, fmt);
1603 case '4':
1604 return ip4_addr_string(buf, end, ptr, spec, fmt);
1605 case 'S': {
1606 const union {
1607 struct sockaddr raw;
1608 struct sockaddr_in v4;
1609 struct sockaddr_in6 v6;
1610 } *sa = ptr;
1611
1612 switch (sa->raw.sa_family) {
1613 case AF_INET:
1614 return ip4_addr_string_sa(buf, end, &sa->v4, spec, fmt);
1615 case AF_INET6:
1616 return ip6_addr_string_sa(buf, end, &sa->v6, spec, fmt);
1617 default:
1618 return error_string(buf, end, "(einval)", spec);
1619 }}
1620 }
1621
1622 err_fmt_msg = fmt[0] == 'i' ? "(%pi?)" : "(%pI?)";
1623 return error_string(buf, end, err_fmt_msg, spec);
1624}
1625
1626static noinline_for_stack
1627char *escaped_string(char *buf, char *end, u8 *addr, struct printf_spec spec,
1628 const char *fmt)
1629{
1630 bool found = true;
1631 int count = 1;
1632 unsigned int flags = 0;
1633 int len;
1634
1635 if (spec.field_width == 0)
1636 return buf; /* nothing to print */
1637
1638 if (check_pointer(&buf, end, addr, spec))
1639 return buf;
1640
1641 do {
1642 switch (fmt[count++]) {
1643 case 'a':
1644 flags |= ESCAPE_ANY;
1645 break;
1646 case 'c':
1647 flags |= ESCAPE_SPECIAL;
1648 break;
1649 case 'h':
1650 flags |= ESCAPE_HEX;
1651 break;
1652 case 'n':
1653 flags |= ESCAPE_NULL;
1654 break;
1655 case 'o':
1656 flags |= ESCAPE_OCTAL;
1657 break;
1658 case 'p':
1659 flags |= ESCAPE_NP;
1660 break;
1661 case 's':
1662 flags |= ESCAPE_SPACE;
1663 break;
1664 default:
1665 found = false;
1666 break;
1667 }
1668 } while (found);
1669
1670 if (!flags)
1671 flags = ESCAPE_ANY_NP;
1672
1673 len = spec.field_width < 0 ? 1 : spec.field_width;
1674
1675 /*
1676 * string_escape_mem() writes as many characters as it can to
1677 * the given buffer, and returns the total size of the output
1678 * had the buffer been big enough.
1679 */
1680 buf += string_escape_mem(addr, len, buf, buf < end ? end - buf : 0, flags, NULL);
1681
1682 return buf;
1683}
1684
1685static char *va_format(char *buf, char *end, struct va_format *va_fmt,
1686 struct printf_spec spec, const char *fmt)
1687{
1688 va_list va;
1689
1690 if (check_pointer(&buf, end, va_fmt, spec))
1691 return buf;
1692
1693 va_copy(va, *va_fmt->va);
1694 buf += vsnprintf(buf, end > buf ? end - buf : 0, va_fmt->fmt, va);
1695 va_end(va);
1696
1697 return buf;
1698}
1699
1700static noinline_for_stack
1701char *uuid_string(char *buf, char *end, const u8 *addr,
1702 struct printf_spec spec, const char *fmt)
1703{
1704 char uuid[UUID_STRING_LEN + 1];
1705 char *p = uuid;
1706 int i;
1707 const u8 *index = uuid_index;
1708 bool uc = false;
1709
1710 if (check_pointer(&buf, end, addr, spec))
1711 return buf;
1712
1713 switch (*(++fmt)) {
1714 case 'L':
1715 uc = true;
1716 fallthrough;
1717 case 'l':
1718 index = guid_index;
1719 break;
1720 case 'B':
1721 uc = true;
1722 break;
1723 }
1724
1725 for (i = 0; i < 16; i++) {
1726 if (uc)
1727 p = hex_byte_pack_upper(p, addr[index[i]]);
1728 else
1729 p = hex_byte_pack(p, addr[index[i]]);
1730 switch (i) {
1731 case 3:
1732 case 5:
1733 case 7:
1734 case 9:
1735 *p++ = '-';
1736 break;
1737 }
1738 }
1739
1740 *p = 0;
1741
1742 return string_nocheck(buf, end, uuid, spec);
1743}
1744
1745static noinline_for_stack
1746char *netdev_bits(char *buf, char *end, const void *addr,
1747 struct printf_spec spec, const char *fmt)
1748{
1749 unsigned long long num;
1750 int size;
1751
1752 if (check_pointer(&buf, end, addr, spec))
1753 return buf;
1754
1755 switch (fmt[1]) {
1756 case 'F':
1757 num = *(const netdev_features_t *)addr;
1758 size = sizeof(netdev_features_t);
1759 break;
1760 default:
1761 return error_string(buf, end, "(%pN?)", spec);
1762 }
1763
1764 return special_hex_number(buf, end, num, size);
1765}
1766
1767static noinline_for_stack
1768char *fourcc_string(char *buf, char *end, const u32 *fourcc,
1769 struct printf_spec spec, const char *fmt)
1770{
1771 char output[sizeof("0123 little-endian (0x01234567)")];
1772 char *p = output;
1773 unsigned int i;
1774 u32 val;
1775
1776 if (fmt[1] != 'c' || fmt[2] != 'c')
1777 return error_string(buf, end, "(%p4?)", spec);
1778
1779 if (check_pointer(&buf, end, fourcc, spec))
1780 return buf;
1781
1782 val = *fourcc & ~BIT(31);
1783
1784 for (i = 0; i < sizeof(*fourcc); i++) {
1785 unsigned char c = val >> (i * 8);
1786
1787 /* Print non-control ASCII characters as-is, dot otherwise */
1788 *p++ = isascii(c) && isprint(c) ? c : '.';
1789 }
1790
1791 strcpy(p, *fourcc & BIT(31) ? " big-endian" : " little-endian");
1792 p += strlen(p);
1793
1794 *p++ = ' ';
1795 *p++ = '(';
1796 p = special_hex_number(p, output + sizeof(output) - 2, *fourcc, sizeof(u32));
1797 *p++ = ')';
1798 *p = '\0';
1799
1800 return string(buf, end, output, spec);
1801}
1802
1803static noinline_for_stack
1804char *address_val(char *buf, char *end, const void *addr,
1805 struct printf_spec spec, const char *fmt)
1806{
1807 unsigned long long num;
1808 int size;
1809
1810 if (check_pointer(&buf, end, addr, spec))
1811 return buf;
1812
1813 switch (fmt[1]) {
1814 case 'd':
1815 num = *(const dma_addr_t *)addr;
1816 size = sizeof(dma_addr_t);
1817 break;
1818 case 'p':
1819 default:
1820 num = *(const phys_addr_t *)addr;
1821 size = sizeof(phys_addr_t);
1822 break;
1823 }
1824
1825 return special_hex_number(buf, end, num, size);
1826}
1827
1828static noinline_for_stack
1829char *date_str(char *buf, char *end, const struct rtc_time *tm, bool r)
1830{
1831 int year = tm->tm_year + (r ? 0 : 1900);
1832 int mon = tm->tm_mon + (r ? 0 : 1);
1833
1834 buf = number(buf, end, year, default_dec04_spec);
1835 if (buf < end)
1836 *buf = '-';
1837 buf++;
1838
1839 buf = number(buf, end, mon, default_dec02_spec);
1840 if (buf < end)
1841 *buf = '-';
1842 buf++;
1843
1844 return number(buf, end, tm->tm_mday, default_dec02_spec);
1845}
1846
1847static noinline_for_stack
1848char *time_str(char *buf, char *end, const struct rtc_time *tm, bool r)
1849{
1850 buf = number(buf, end, tm->tm_hour, default_dec02_spec);
1851 if (buf < end)
1852 *buf = ':';
1853 buf++;
1854
1855 buf = number(buf, end, tm->tm_min, default_dec02_spec);
1856 if (buf < end)
1857 *buf = ':';
1858 buf++;
1859
1860 return number(buf, end, tm->tm_sec, default_dec02_spec);
1861}
1862
1863static noinline_for_stack
1864char *rtc_str(char *buf, char *end, const struct rtc_time *tm,
1865 struct printf_spec spec, const char *fmt)
1866{
1867 bool have_t = true, have_d = true;
1868 bool raw = false, iso8601_separator = true;
1869 bool found = true;
1870 int count = 2;
1871
1872 if (check_pointer(&buf, end, tm, spec))
1873 return buf;
1874
1875 switch (fmt[count]) {
1876 case 'd':
1877 have_t = false;
1878 count++;
1879 break;
1880 case 't':
1881 have_d = false;
1882 count++;
1883 break;
1884 }
1885
1886 do {
1887 switch (fmt[count++]) {
1888 case 'r':
1889 raw = true;
1890 break;
1891 case 's':
1892 iso8601_separator = false;
1893 break;
1894 default:
1895 found = false;
1896 break;
1897 }
1898 } while (found);
1899
1900 if (have_d)
1901 buf = date_str(buf, end, tm, raw);
1902 if (have_d && have_t) {
1903 if (buf < end)
1904 *buf = iso8601_separator ? 'T' : ' ';
1905 buf++;
1906 }
1907 if (have_t)
1908 buf = time_str(buf, end, tm, raw);
1909
1910 return buf;
1911}
1912
1913static noinline_for_stack
1914char *time64_str(char *buf, char *end, const time64_t time,
1915 struct printf_spec spec, const char *fmt)
1916{
1917 struct rtc_time rtc_time;
1918 struct tm tm;
1919
1920 time64_to_tm(time, 0, &tm);
1921
1922 rtc_time.tm_sec = tm.tm_sec;
1923 rtc_time.tm_min = tm.tm_min;
1924 rtc_time.tm_hour = tm.tm_hour;
1925 rtc_time.tm_mday = tm.tm_mday;
1926 rtc_time.tm_mon = tm.tm_mon;
1927 rtc_time.tm_year = tm.tm_year;
1928 rtc_time.tm_wday = tm.tm_wday;
1929 rtc_time.tm_yday = tm.tm_yday;
1930
1931 rtc_time.tm_isdst = 0;
1932
1933 return rtc_str(buf, end, &rtc_time, spec, fmt);
1934}
1935
1936static noinline_for_stack
1937char *time_and_date(char *buf, char *end, void *ptr, struct printf_spec spec,
1938 const char *fmt)
1939{
1940 switch (fmt[1]) {
1941 case 'R':
1942 return rtc_str(buf, end, (const struct rtc_time *)ptr, spec, fmt);
1943 case 'T':
1944 return time64_str(buf, end, *(const time64_t *)ptr, spec, fmt);
1945 default:
1946 return error_string(buf, end, "(%pt?)", spec);
1947 }
1948}
1949
1950static noinline_for_stack
1951char *clock(char *buf, char *end, struct clk *clk, struct printf_spec spec,
1952 const char *fmt)
1953{
1954 if (!IS_ENABLED(CONFIG_HAVE_CLK))
1955 return error_string(buf, end, "(%pC?)", spec);
1956
1957 if (check_pointer(&buf, end, clk, spec))
1958 return buf;
1959
1960 switch (fmt[1]) {
1961 case 'n':
1962 default:
1963#ifdef CONFIG_COMMON_CLK
1964 return string(buf, end, __clk_get_name(clk), spec);
1965#else
1966 return ptr_to_id(buf, end, clk, spec);
1967#endif
1968 }
1969}
1970
1971static
1972char *format_flags(char *buf, char *end, unsigned long flags,
1973 const struct trace_print_flags *names)
1974{
1975 unsigned long mask;
1976
1977 for ( ; flags && names->name; names++) {
1978 mask = names->mask;
1979 if ((flags & mask) != mask)
1980 continue;
1981
1982 buf = string(buf, end, names->name, default_str_spec);
1983
1984 flags &= ~mask;
1985 if (flags) {
1986 if (buf < end)
1987 *buf = '|';
1988 buf++;
1989 }
1990 }
1991
1992 if (flags)
1993 buf = number(buf, end, flags, default_flag_spec);
1994
1995 return buf;
1996}
1997
1998struct page_flags_fields {
1999 int width;
2000 int shift;
2001 int mask;
2002 const struct printf_spec *spec;
2003 const char *name;
2004};
2005
2006static const struct page_flags_fields pff[] = {
2007 {SECTIONS_WIDTH, SECTIONS_PGSHIFT, SECTIONS_MASK,
2008 &default_dec_spec, "section"},
2009 {NODES_WIDTH, NODES_PGSHIFT, NODES_MASK,
2010 &default_dec_spec, "node"},
2011 {ZONES_WIDTH, ZONES_PGSHIFT, ZONES_MASK,
2012 &default_dec_spec, "zone"},
2013 {LAST_CPUPID_WIDTH, LAST_CPUPID_PGSHIFT, LAST_CPUPID_MASK,
2014 &default_flag_spec, "lastcpupid"},
2015 {KASAN_TAG_WIDTH, KASAN_TAG_PGSHIFT, KASAN_TAG_MASK,
2016 &default_flag_spec, "kasantag"},
2017};
2018
2019static
2020char *format_page_flags(char *buf, char *end, unsigned long flags)
2021{
2022 unsigned long main_flags = flags & PAGEFLAGS_MASK;
2023 bool append = false;
2024 int i;
2025
2026 /* Page flags from the main area. */
2027 if (main_flags) {
2028 buf = format_flags(buf, end, main_flags, pageflag_names);
2029 append = true;
2030 }
2031
2032 /* Page flags from the fields area */
2033 for (i = 0; i < ARRAY_SIZE(pff); i++) {
2034 /* Skip undefined fields. */
2035 if (!pff[i].width)
2036 continue;
2037
2038 /* Format: Flag Name + '=' (equals sign) + Number + '|' (separator) */
2039 if (append) {
2040 if (buf < end)
2041 *buf = '|';
2042 buf++;
2043 }
2044
2045 buf = string(buf, end, pff[i].name, default_str_spec);
2046 if (buf < end)
2047 *buf = '=';
2048 buf++;
2049 buf = number(buf, end, (flags >> pff[i].shift) & pff[i].mask,
2050 *pff[i].spec);
2051
2052 append = true;
2053 }
2054
2055 return buf;
2056}
2057
2058static noinline_for_stack
2059char *flags_string(char *buf, char *end, void *flags_ptr,
2060 struct printf_spec spec, const char *fmt)
2061{
2062 unsigned long flags;
2063 const struct trace_print_flags *names;
2064
2065 if (check_pointer(&buf, end, flags_ptr, spec))
2066 return buf;
2067
2068 switch (fmt[1]) {
2069 case 'p':
2070 return format_page_flags(buf, end, *(unsigned long *)flags_ptr);
2071 case 'v':
2072 flags = *(unsigned long *)flags_ptr;
2073 names = vmaflag_names;
2074 break;
2075 case 'g':
2076 flags = (__force unsigned long)(*(gfp_t *)flags_ptr);
2077 names = gfpflag_names;
2078 break;
2079 default:
2080 return error_string(buf, end, "(%pG?)", spec);
2081 }
2082
2083 return format_flags(buf, end, flags, names);
2084}
2085
2086static noinline_for_stack
2087char *fwnode_full_name_string(struct fwnode_handle *fwnode, char *buf,
2088 char *end)
2089{
2090 int depth;
2091
2092 /* Loop starting from the root node to the current node. */
2093 for (depth = fwnode_count_parents(fwnode); depth >= 0; depth--) {
2094 struct fwnode_handle *__fwnode =
2095 fwnode_get_nth_parent(fwnode, depth);
2096
2097 buf = string(buf, end, fwnode_get_name_prefix(__fwnode),
2098 default_str_spec);
2099 buf = string(buf, end, fwnode_get_name(__fwnode),
2100 default_str_spec);
2101
2102 fwnode_handle_put(__fwnode);
2103 }
2104
2105 return buf;
2106}
2107
2108static noinline_for_stack
2109char *device_node_string(char *buf, char *end, struct device_node *dn,
2110 struct printf_spec spec, const char *fmt)
2111{
2112 char tbuf[sizeof("xxxx") + 1];
2113 const char *p;
2114 int ret;
2115 char *buf_start = buf;
2116 struct property *prop;
2117 bool has_mult, pass;
2118
2119 struct printf_spec str_spec = spec;
2120 str_spec.field_width = -1;
2121
2122 if (fmt[0] != 'F')
2123 return error_string(buf, end, "(%pO?)", spec);
2124
2125 if (!IS_ENABLED(CONFIG_OF))
2126 return error_string(buf, end, "(%pOF?)", spec);
2127
2128 if (check_pointer(&buf, end, dn, spec))
2129 return buf;
2130
2131 /* simple case without anything any more format specifiers */
2132 fmt++;
2133 if (fmt[0] == '\0' || strcspn(fmt,"fnpPFcC") > 0)
2134 fmt = "f";
2135
2136 for (pass = false; strspn(fmt,"fnpPFcC"); fmt++, pass = true) {
2137 int precision;
2138 if (pass) {
2139 if (buf < end)
2140 *buf = ':';
2141 buf++;
2142 }
2143
2144 switch (*fmt) {
2145 case 'f': /* full_name */
2146 buf = fwnode_full_name_string(of_fwnode_handle(dn), buf,
2147 end);
2148 break;
2149 case 'n': /* name */
2150 p = fwnode_get_name(of_fwnode_handle(dn));
2151 precision = str_spec.precision;
2152 str_spec.precision = strchrnul(p, '@') - p;
2153 buf = string(buf, end, p, str_spec);
2154 str_spec.precision = precision;
2155 break;
2156 case 'p': /* phandle */
2157 buf = number(buf, end, (unsigned int)dn->phandle, default_dec_spec);
2158 break;
2159 case 'P': /* path-spec */
2160 p = fwnode_get_name(of_fwnode_handle(dn));
2161 if (!p[1])
2162 p = "/";
2163 buf = string(buf, end, p, str_spec);
2164 break;
2165 case 'F': /* flags */
2166 tbuf[0] = of_node_check_flag(dn, OF_DYNAMIC) ? 'D' : '-';
2167 tbuf[1] = of_node_check_flag(dn, OF_DETACHED) ? 'd' : '-';
2168 tbuf[2] = of_node_check_flag(dn, OF_POPULATED) ? 'P' : '-';
2169 tbuf[3] = of_node_check_flag(dn, OF_POPULATED_BUS) ? 'B' : '-';
2170 tbuf[4] = 0;
2171 buf = string_nocheck(buf, end, tbuf, str_spec);
2172 break;
2173 case 'c': /* major compatible string */
2174 ret = of_property_read_string(dn, "compatible", &p);
2175 if (!ret)
2176 buf = string(buf, end, p, str_spec);
2177 break;
2178 case 'C': /* full compatible string */
2179 has_mult = false;
2180 of_property_for_each_string(dn, "compatible", prop, p) {
2181 if (has_mult)
2182 buf = string_nocheck(buf, end, ",", str_spec);
2183 buf = string_nocheck(buf, end, "\"", str_spec);
2184 buf = string(buf, end, p, str_spec);
2185 buf = string_nocheck(buf, end, "\"", str_spec);
2186
2187 has_mult = true;
2188 }
2189 break;
2190 default:
2191 break;
2192 }
2193 }
2194
2195 return widen_string(buf, buf - buf_start, end, spec);
2196}
2197
2198static noinline_for_stack
2199char *fwnode_string(char *buf, char *end, struct fwnode_handle *fwnode,
2200 struct printf_spec spec, const char *fmt)
2201{
2202 struct printf_spec str_spec = spec;
2203 char *buf_start = buf;
2204
2205 str_spec.field_width = -1;
2206
2207 if (*fmt != 'w')
2208 return error_string(buf, end, "(%pf?)", spec);
2209
2210 if (check_pointer(&buf, end, fwnode, spec))
2211 return buf;
2212
2213 fmt++;
2214
2215 switch (*fmt) {
2216 case 'P': /* name */
2217 buf = string(buf, end, fwnode_get_name(fwnode), str_spec);
2218 break;
2219 case 'f': /* full_name */
2220 default:
2221 buf = fwnode_full_name_string(fwnode, buf, end);
2222 break;
2223 }
2224
2225 return widen_string(buf, buf - buf_start, end, spec);
2226}
2227
2228/* Disable pointer hashing if requested */
2229bool no_hash_pointers __ro_after_init;
2230EXPORT_SYMBOL_GPL(no_hash_pointers);
2231
2232int __init no_hash_pointers_enable(char *str)
2233{
2234 if (no_hash_pointers)
2235 return 0;
2236
2237 no_hash_pointers = true;
2238
2239 pr_warn("**********************************************************\n");
2240 pr_warn("** NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE **\n");
2241 pr_warn("** **\n");
2242 pr_warn("** This system shows unhashed kernel memory addresses **\n");
2243 pr_warn("** via the console, logs, and other interfaces. This **\n");
2244 pr_warn("** might reduce the security of your system. **\n");
2245 pr_warn("** **\n");
2246 pr_warn("** If you see this message and you are not debugging **\n");
2247 pr_warn("** the kernel, report this immediately to your system **\n");
2248 pr_warn("** administrator! **\n");
2249 pr_warn("** **\n");
2250 pr_warn("** NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE **\n");
2251 pr_warn("**********************************************************\n");
2252
2253 return 0;
2254}
2255early_param("no_hash_pointers", no_hash_pointers_enable);
2256
2257/*
2258 * Show a '%p' thing. A kernel extension is that the '%p' is followed
2259 * by an extra set of alphanumeric characters that are extended format
2260 * specifiers.
2261 *
2262 * Please update scripts/checkpatch.pl when adding/removing conversion
2263 * characters. (Search for "check for vsprintf extension").
2264 *
2265 * Right now we handle:
2266 *
2267 * - 'S' For symbolic direct pointers (or function descriptors) with offset
2268 * - 's' For symbolic direct pointers (or function descriptors) without offset
2269 * - '[Ss]R' as above with __builtin_extract_return_addr() translation
2270 * - 'S[R]b' as above with module build ID (for use in backtraces)
2271 * - '[Ff]' %pf and %pF were obsoleted and later removed in favor of
2272 * %ps and %pS. Be careful when re-using these specifiers.
2273 * - 'B' For backtraced symbolic direct pointers with offset
2274 * - 'Bb' as above with module build ID (for use in backtraces)
2275 * - 'R' For decoded struct resource, e.g., [mem 0x0-0x1f 64bit pref]
2276 * - 'r' For raw struct resource, e.g., [mem 0x0-0x1f flags 0x201]
2277 * - 'b[l]' For a bitmap, the number of bits is determined by the field
2278 * width which must be explicitly specified either as part of the
2279 * format string '%32b[l]' or through '%*b[l]', [l] selects
2280 * range-list format instead of hex format
2281 * - 'M' For a 6-byte MAC address, it prints the address in the
2282 * usual colon-separated hex notation
2283 * - 'm' For a 6-byte MAC address, it prints the hex address without colons
2284 * - 'MF' For a 6-byte MAC FDDI address, it prints the address
2285 * with a dash-separated hex notation
2286 * - '[mM]R' For a 6-byte MAC address, Reverse order (Bluetooth)
2287 * - 'I' [46] for IPv4/IPv6 addresses printed in the usual way
2288 * IPv4 uses dot-separated decimal without leading 0's (1.2.3.4)
2289 * IPv6 uses colon separated network-order 16 bit hex with leading 0's
2290 * [S][pfs]
2291 * Generic IPv4/IPv6 address (struct sockaddr *) that falls back to
2292 * [4] or [6] and is able to print port [p], flowinfo [f], scope [s]
2293 * - 'i' [46] for 'raw' IPv4/IPv6 addresses
2294 * IPv6 omits the colons (01020304...0f)
2295 * IPv4 uses dot-separated decimal with leading 0's (010.123.045.006)
2296 * [S][pfs]
2297 * Generic IPv4/IPv6 address (struct sockaddr *) that falls back to
2298 * [4] or [6] and is able to print port [p], flowinfo [f], scope [s]
2299 * - '[Ii][4S][hnbl]' IPv4 addresses in host, network, big or little endian order
2300 * - 'I[6S]c' for IPv6 addresses printed as specified by
2301 * https://tools.ietf.org/html/rfc5952
2302 * - 'E[achnops]' For an escaped buffer, where rules are defined by combination
2303 * of the following flags (see string_escape_mem() for the
2304 * details):
2305 * a - ESCAPE_ANY
2306 * c - ESCAPE_SPECIAL
2307 * h - ESCAPE_HEX
2308 * n - ESCAPE_NULL
2309 * o - ESCAPE_OCTAL
2310 * p - ESCAPE_NP
2311 * s - ESCAPE_SPACE
2312 * By default ESCAPE_ANY_NP is used.
2313 * - 'U' For a 16 byte UUID/GUID, it prints the UUID/GUID in the form
2314 * "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx"
2315 * Options for %pU are:
2316 * b big endian lower case hex (default)
2317 * B big endian UPPER case hex
2318 * l little endian lower case hex
2319 * L little endian UPPER case hex
2320 * big endian output byte order is:
2321 * [0][1][2][3]-[4][5]-[6][7]-[8][9]-[10][11][12][13][14][15]
2322 * little endian output byte order is:
2323 * [3][2][1][0]-[5][4]-[7][6]-[8][9]-[10][11][12][13][14][15]
2324 * - 'V' For a struct va_format which contains a format string * and va_list *,
2325 * call vsnprintf(->format, *->va_list).
2326 * Implements a "recursive vsnprintf".
2327 * Do not use this feature without some mechanism to verify the
2328 * correctness of the format string and va_list arguments.
2329 * - 'K' For a kernel pointer that should be hidden from unprivileged users.
2330 * Use only for procfs, sysfs and similar files, not printk(); please
2331 * read the documentation (path below) first.
2332 * - 'NF' For a netdev_features_t
2333 * - '4cc' V4L2 or DRM FourCC code, with endianness and raw numerical value.
2334 * - 'h[CDN]' For a variable-length buffer, it prints it as a hex string with
2335 * a certain separator (' ' by default):
2336 * C colon
2337 * D dash
2338 * N no separator
2339 * The maximum supported length is 64 bytes of the input. Consider
2340 * to use print_hex_dump() for the larger input.
2341 * - 'a[pd]' For address types [p] phys_addr_t, [d] dma_addr_t and derivatives
2342 * (default assumed to be phys_addr_t, passed by reference)
2343 * - 'd[234]' For a dentry name (optionally 2-4 last components)
2344 * - 'D[234]' Same as 'd' but for a struct file
2345 * - 'g' For block_device name (gendisk + partition number)
2346 * - 't[RT][dt][r][s]' For time and date as represented by:
2347 * R struct rtc_time
2348 * T time64_t
2349 * - 'C' For a clock, it prints the name (Common Clock Framework) or address
2350 * (legacy clock framework) of the clock
2351 * - 'Cn' For a clock, it prints the name (Common Clock Framework) or address
2352 * (legacy clock framework) of the clock
2353 * - 'G' For flags to be printed as a collection of symbolic strings that would
2354 * construct the specific value. Supported flags given by option:
2355 * p page flags (see struct page) given as pointer to unsigned long
2356 * g gfp flags (GFP_* and __GFP_*) given as pointer to gfp_t
2357 * v vma flags (VM_*) given as pointer to unsigned long
2358 * - 'OF[fnpPcCF]' For a device tree object
2359 * Without any optional arguments prints the full_name
2360 * f device node full_name
2361 * n device node name
2362 * p device node phandle
2363 * P device node path spec (name + @unit)
2364 * F device node flags
2365 * c major compatible string
2366 * C full compatible string
2367 * - 'fw[fP]' For a firmware node (struct fwnode_handle) pointer
2368 * Without an option prints the full name of the node
2369 * f full name
2370 * P node name, including a possible unit address
2371 * - 'x' For printing the address unmodified. Equivalent to "%lx".
2372 * Please read the documentation (path below) before using!
2373 * - '[ku]s' For a BPF/tracing related format specifier, e.g. used out of
2374 * bpf_trace_printk() where [ku] prefix specifies either kernel (k)
2375 * or user (u) memory to probe, and:
2376 * s a string, equivalent to "%s" on direct vsnprintf() use
2377 *
2378 * ** When making changes please also update:
2379 * Documentation/core-api/printk-formats.rst
2380 *
2381 * Note: The default behaviour (unadorned %p) is to hash the address,
2382 * rendering it useful as a unique identifier.
2383 */
2384static noinline_for_stack
2385char *pointer(const char *fmt, char *buf, char *end, void *ptr,
2386 struct printf_spec spec)
2387{
2388 switch (*fmt) {
2389 case 'S':
2390 case 's':
2391 ptr = dereference_symbol_descriptor(ptr);
2392 fallthrough;
2393 case 'B':
2394 return symbol_string(buf, end, ptr, spec, fmt);
2395 case 'R':
2396 case 'r':
2397 return resource_string(buf, end, ptr, spec, fmt);
2398 case 'h':
2399 return hex_string(buf, end, ptr, spec, fmt);
2400 case 'b':
2401 switch (fmt[1]) {
2402 case 'l':
2403 return bitmap_list_string(buf, end, ptr, spec, fmt);
2404 default:
2405 return bitmap_string(buf, end, ptr, spec, fmt);
2406 }
2407 case 'M': /* Colon separated: 00:01:02:03:04:05 */
2408 case 'm': /* Contiguous: 000102030405 */
2409 /* [mM]F (FDDI) */
2410 /* [mM]R (Reverse order; Bluetooth) */
2411 return mac_address_string(buf, end, ptr, spec, fmt);
2412 case 'I': /* Formatted IP supported
2413 * 4: 1.2.3.4
2414 * 6: 0001:0203:...:0708
2415 * 6c: 1::708 or 1::1.2.3.4
2416 */
2417 case 'i': /* Contiguous:
2418 * 4: 001.002.003.004
2419 * 6: 000102...0f
2420 */
2421 return ip_addr_string(buf, end, ptr, spec, fmt);
2422 case 'E':
2423 return escaped_string(buf, end, ptr, spec, fmt);
2424 case 'U':
2425 return uuid_string(buf, end, ptr, spec, fmt);
2426 case 'V':
2427 return va_format(buf, end, ptr, spec, fmt);
2428 case 'K':
2429 return restricted_pointer(buf, end, ptr, spec);
2430 case 'N':
2431 return netdev_bits(buf, end, ptr, spec, fmt);
2432 case '4':
2433 return fourcc_string(buf, end, ptr, spec, fmt);
2434 case 'a':
2435 return address_val(buf, end, ptr, spec, fmt);
2436 case 'd':
2437 return dentry_name(buf, end, ptr, spec, fmt);
2438 case 't':
2439 return time_and_date(buf, end, ptr, spec, fmt);
2440 case 'C':
2441 return clock(buf, end, ptr, spec, fmt);
2442 case 'D':
2443 return file_dentry_name(buf, end, ptr, spec, fmt);
2444#ifdef CONFIG_BLOCK
2445 case 'g':
2446 return bdev_name(buf, end, ptr, spec, fmt);
2447#endif
2448
2449 case 'G':
2450 return flags_string(buf, end, ptr, spec, fmt);
2451 case 'O':
2452 return device_node_string(buf, end, ptr, spec, fmt + 1);
2453 case 'f':
2454 return fwnode_string(buf, end, ptr, spec, fmt + 1);
2455 case 'x':
2456 return pointer_string(buf, end, ptr, spec);
2457 case 'e':
2458 /* %pe with a non-ERR_PTR gets treated as plain %p */
2459 if (!IS_ERR(ptr))
2460 break;
2461 return err_ptr(buf, end, ptr, spec);
2462 case 'u':
2463 case 'k':
2464 switch (fmt[1]) {
2465 case 's':
2466 return string(buf, end, ptr, spec);
2467 default:
2468 return error_string(buf, end, "(einval)", spec);
2469 }
2470 }
2471
2472 /*
2473 * default is to _not_ leak addresses, so hash before printing,
2474 * unless no_hash_pointers is specified on the command line.
2475 */
2476 if (unlikely(no_hash_pointers))
2477 return pointer_string(buf, end, ptr, spec);
2478 else
2479 return ptr_to_id(buf, end, ptr, spec);
2480}
2481
2482/*
2483 * Helper function to decode printf style format.
2484 * Each call decode a token from the format and return the
2485 * number of characters read (or likely the delta where it wants
2486 * to go on the next call).
2487 * The decoded token is returned through the parameters
2488 *
2489 * 'h', 'l', or 'L' for integer fields
2490 * 'z' support added 23/7/1999 S.H.
2491 * 'z' changed to 'Z' --davidm 1/25/99
2492 * 'Z' changed to 'z' --adobriyan 2017-01-25
2493 * 't' added for ptrdiff_t
2494 *
2495 * @fmt: the format string
2496 * @type of the token returned
2497 * @flags: various flags such as +, -, # tokens..
2498 * @field_width: overwritten width
2499 * @base: base of the number (octal, hex, ...)
2500 * @precision: precision of a number
2501 * @qualifier: qualifier of a number (long, size_t, ...)
2502 */
2503static noinline_for_stack
2504int format_decode(const char *fmt, struct printf_spec *spec)
2505{
2506 const char *start = fmt;
2507 char qualifier;
2508
2509 /* we finished early by reading the field width */
2510 if (spec->type == FORMAT_TYPE_WIDTH) {
2511 if (spec->field_width < 0) {
2512 spec->field_width = -spec->field_width;
2513 spec->flags |= LEFT;
2514 }
2515 spec->type = FORMAT_TYPE_NONE;
2516 goto precision;
2517 }
2518
2519 /* we finished early by reading the precision */
2520 if (spec->type == FORMAT_TYPE_PRECISION) {
2521 if (spec->precision < 0)
2522 spec->precision = 0;
2523
2524 spec->type = FORMAT_TYPE_NONE;
2525 goto qualifier;
2526 }
2527
2528 /* By default */
2529 spec->type = FORMAT_TYPE_NONE;
2530
2531 for (; *fmt ; ++fmt) {
2532 if (*fmt == '%')
2533 break;
2534 }
2535
2536 /* Return the current non-format string */
2537 if (fmt != start || !*fmt)
2538 return fmt - start;
2539
2540 /* Process flags */
2541 spec->flags = 0;
2542
2543 while (1) { /* this also skips first '%' */
2544 bool found = true;
2545
2546 ++fmt;
2547
2548 switch (*fmt) {
2549 case '-': spec->flags |= LEFT; break;
2550 case '+': spec->flags |= PLUS; break;
2551 case ' ': spec->flags |= SPACE; break;
2552 case '#': spec->flags |= SPECIAL; break;
2553 case '0': spec->flags |= ZEROPAD; break;
2554 default: found = false;
2555 }
2556
2557 if (!found)
2558 break;
2559 }
2560
2561 /* get field width */
2562 spec->field_width = -1;
2563
2564 if (isdigit(*fmt))
2565 spec->field_width = skip_atoi(&fmt);
2566 else if (*fmt == '*') {
2567 /* it's the next argument */
2568 spec->type = FORMAT_TYPE_WIDTH;
2569 return ++fmt - start;
2570 }
2571
2572precision:
2573 /* get the precision */
2574 spec->precision = -1;
2575 if (*fmt == '.') {
2576 ++fmt;
2577 if (isdigit(*fmt)) {
2578 spec->precision = skip_atoi(&fmt);
2579 if (spec->precision < 0)
2580 spec->precision = 0;
2581 } else if (*fmt == '*') {
2582 /* it's the next argument */
2583 spec->type = FORMAT_TYPE_PRECISION;
2584 return ++fmt - start;
2585 }
2586 }
2587
2588qualifier:
2589 /* get the conversion qualifier */
2590 qualifier = 0;
2591 if (*fmt == 'h' || _tolower(*fmt) == 'l' ||
2592 *fmt == 'z' || *fmt == 't') {
2593 qualifier = *fmt++;
2594 if (unlikely(qualifier == *fmt)) {
2595 if (qualifier == 'l') {
2596 qualifier = 'L';
2597 ++fmt;
2598 } else if (qualifier == 'h') {
2599 qualifier = 'H';
2600 ++fmt;
2601 }
2602 }
2603 }
2604
2605 /* default base */
2606 spec->base = 10;
2607 switch (*fmt) {
2608 case 'c':
2609 spec->type = FORMAT_TYPE_CHAR;
2610 return ++fmt - start;
2611
2612 case 's':
2613 spec->type = FORMAT_TYPE_STR;
2614 return ++fmt - start;
2615
2616 case 'p':
2617 spec->type = FORMAT_TYPE_PTR;
2618 return ++fmt - start;
2619
2620 case '%':
2621 spec->type = FORMAT_TYPE_PERCENT_CHAR;
2622 return ++fmt - start;
2623
2624 /* integer number formats - set up the flags and "break" */
2625 case 'o':
2626 spec->base = 8;
2627 break;
2628
2629 case 'x':
2630 spec->flags |= SMALL;
2631 fallthrough;
2632
2633 case 'X':
2634 spec->base = 16;
2635 break;
2636
2637 case 'd':
2638 case 'i':
2639 spec->flags |= SIGN;
2640 break;
2641 case 'u':
2642 break;
2643
2644 case 'n':
2645 /*
2646 * Since %n poses a greater security risk than
2647 * utility, treat it as any other invalid or
2648 * unsupported format specifier.
2649 */
2650 fallthrough;
2651
2652 default:
2653 WARN_ONCE(1, "Please remove unsupported %%%c in format string\n", *fmt);
2654 spec->type = FORMAT_TYPE_INVALID;
2655 return fmt - start;
2656 }
2657
2658 if (qualifier == 'L')
2659 spec->type = FORMAT_TYPE_LONG_LONG;
2660 else if (qualifier == 'l') {
2661 BUILD_BUG_ON(FORMAT_TYPE_ULONG + SIGN != FORMAT_TYPE_LONG);
2662 spec->type = FORMAT_TYPE_ULONG + (spec->flags & SIGN);
2663 } else if (qualifier == 'z') {
2664 spec->type = FORMAT_TYPE_SIZE_T;
2665 } else if (qualifier == 't') {
2666 spec->type = FORMAT_TYPE_PTRDIFF;
2667 } else if (qualifier == 'H') {
2668 BUILD_BUG_ON(FORMAT_TYPE_UBYTE + SIGN != FORMAT_TYPE_BYTE);
2669 spec->type = FORMAT_TYPE_UBYTE + (spec->flags & SIGN);
2670 } else if (qualifier == 'h') {
2671 BUILD_BUG_ON(FORMAT_TYPE_USHORT + SIGN != FORMAT_TYPE_SHORT);
2672 spec->type = FORMAT_TYPE_USHORT + (spec->flags & SIGN);
2673 } else {
2674 BUILD_BUG_ON(FORMAT_TYPE_UINT + SIGN != FORMAT_TYPE_INT);
2675 spec->type = FORMAT_TYPE_UINT + (spec->flags & SIGN);
2676 }
2677
2678 return ++fmt - start;
2679}
2680
2681static void
2682set_field_width(struct printf_spec *spec, int width)
2683{
2684 spec->field_width = width;
2685 if (WARN_ONCE(spec->field_width != width, "field width %d too large", width)) {
2686 spec->field_width = clamp(width, -FIELD_WIDTH_MAX, FIELD_WIDTH_MAX);
2687 }
2688}
2689
2690static void
2691set_precision(struct printf_spec *spec, int prec)
2692{
2693 spec->precision = prec;
2694 if (WARN_ONCE(spec->precision != prec, "precision %d too large", prec)) {
2695 spec->precision = clamp(prec, 0, PRECISION_MAX);
2696 }
2697}
2698
2699/**
2700 * vsnprintf - Format a string and place it in a buffer
2701 * @buf: The buffer to place the result into
2702 * @size: The size of the buffer, including the trailing null space
2703 * @fmt: The format string to use
2704 * @args: Arguments for the format string
2705 *
2706 * This function generally follows C99 vsnprintf, but has some
2707 * extensions and a few limitations:
2708 *
2709 * - ``%n`` is unsupported
2710 * - ``%p*`` is handled by pointer()
2711 *
2712 * See pointer() or Documentation/core-api/printk-formats.rst for more
2713 * extensive description.
2714 *
2715 * **Please update the documentation in both places when making changes**
2716 *
2717 * The return value is the number of characters which would
2718 * be generated for the given input, excluding the trailing
2719 * '\0', as per ISO C99. If you want to have the exact
2720 * number of characters written into @buf as return value
2721 * (not including the trailing '\0'), use vscnprintf(). If the
2722 * return is greater than or equal to @size, the resulting
2723 * string is truncated.
2724 *
2725 * If you're not already dealing with a va_list consider using snprintf().
2726 */
2727int vsnprintf(char *buf, size_t size, const char *fmt, va_list args)
2728{
2729 unsigned long long num;
2730 char *str, *end;
2731 struct printf_spec spec = {0};
2732
2733 /* Reject out-of-range values early. Large positive sizes are
2734 used for unknown buffer sizes. */
2735 if (WARN_ON_ONCE(size > INT_MAX))
2736 return 0;
2737
2738 str = buf;
2739 end = buf + size;
2740
2741 /* Make sure end is always >= buf */
2742 if (end < buf) {
2743 end = ((void *)-1);
2744 size = end - buf;
2745 }
2746
2747 while (*fmt) {
2748 const char *old_fmt = fmt;
2749 int read = format_decode(fmt, &spec);
2750
2751 fmt += read;
2752
2753 switch (spec.type) {
2754 case FORMAT_TYPE_NONE: {
2755 int copy = read;
2756 if (str < end) {
2757 if (copy > end - str)
2758 copy = end - str;
2759 memcpy(str, old_fmt, copy);
2760 }
2761 str += read;
2762 break;
2763 }
2764
2765 case FORMAT_TYPE_WIDTH:
2766 set_field_width(&spec, va_arg(args, int));
2767 break;
2768
2769 case FORMAT_TYPE_PRECISION:
2770 set_precision(&spec, va_arg(args, int));
2771 break;
2772
2773 case FORMAT_TYPE_CHAR: {
2774 char c;
2775
2776 if (!(spec.flags & LEFT)) {
2777 while (--spec.field_width > 0) {
2778 if (str < end)
2779 *str = ' ';
2780 ++str;
2781
2782 }
2783 }
2784 c = (unsigned char) va_arg(args, int);
2785 if (str < end)
2786 *str = c;
2787 ++str;
2788 while (--spec.field_width > 0) {
2789 if (str < end)
2790 *str = ' ';
2791 ++str;
2792 }
2793 break;
2794 }
2795
2796 case FORMAT_TYPE_STR:
2797 str = string(str, end, va_arg(args, char *), spec);
2798 break;
2799
2800 case FORMAT_TYPE_PTR:
2801 str = pointer(fmt, str, end, va_arg(args, void *),
2802 spec);
2803 while (isalnum(*fmt))
2804 fmt++;
2805 break;
2806
2807 case FORMAT_TYPE_PERCENT_CHAR:
2808 if (str < end)
2809 *str = '%';
2810 ++str;
2811 break;
2812
2813 case FORMAT_TYPE_INVALID:
2814 /*
2815 * Presumably the arguments passed gcc's type
2816 * checking, but there is no safe or sane way
2817 * for us to continue parsing the format and
2818 * fetching from the va_list; the remaining
2819 * specifiers and arguments would be out of
2820 * sync.
2821 */
2822 goto out;
2823
2824 default:
2825 switch (spec.type) {
2826 case FORMAT_TYPE_LONG_LONG:
2827 num = va_arg(args, long long);
2828 break;
2829 case FORMAT_TYPE_ULONG:
2830 num = va_arg(args, unsigned long);
2831 break;
2832 case FORMAT_TYPE_LONG:
2833 num = va_arg(args, long);
2834 break;
2835 case FORMAT_TYPE_SIZE_T:
2836 if (spec.flags & SIGN)
2837 num = va_arg(args, ssize_t);
2838 else
2839 num = va_arg(args, size_t);
2840 break;
2841 case FORMAT_TYPE_PTRDIFF:
2842 num = va_arg(args, ptrdiff_t);
2843 break;
2844 case FORMAT_TYPE_UBYTE:
2845 num = (unsigned char) va_arg(args, int);
2846 break;
2847 case FORMAT_TYPE_BYTE:
2848 num = (signed char) va_arg(args, int);
2849 break;
2850 case FORMAT_TYPE_USHORT:
2851 num = (unsigned short) va_arg(args, int);
2852 break;
2853 case FORMAT_TYPE_SHORT:
2854 num = (short) va_arg(args, int);
2855 break;
2856 case FORMAT_TYPE_INT:
2857 num = (int) va_arg(args, int);
2858 break;
2859 default:
2860 num = va_arg(args, unsigned int);
2861 }
2862
2863 str = number(str, end, num, spec);
2864 }
2865 }
2866
2867out:
2868 if (size > 0) {
2869 if (str < end)
2870 *str = '\0';
2871 else
2872 end[-1] = '\0';
2873 }
2874
2875 /* the trailing null byte doesn't count towards the total */
2876 return str-buf;
2877
2878}
2879EXPORT_SYMBOL(vsnprintf);
2880
2881/**
2882 * vscnprintf - Format a string and place it in a buffer
2883 * @buf: The buffer to place the result into
2884 * @size: The size of the buffer, including the trailing null space
2885 * @fmt: The format string to use
2886 * @args: Arguments for the format string
2887 *
2888 * The return value is the number of characters which have been written into
2889 * the @buf not including the trailing '\0'. If @size is == 0 the function
2890 * returns 0.
2891 *
2892 * If you're not already dealing with a va_list consider using scnprintf().
2893 *
2894 * See the vsnprintf() documentation for format string extensions over C99.
2895 */
2896int vscnprintf(char *buf, size_t size, const char *fmt, va_list args)
2897{
2898 int i;
2899
2900 i = vsnprintf(buf, size, fmt, args);
2901
2902 if (likely(i < size))
2903 return i;
2904 if (size != 0)
2905 return size - 1;
2906 return 0;
2907}
2908EXPORT_SYMBOL(vscnprintf);
2909
2910/**
2911 * snprintf - Format a string and place it in a buffer
2912 * @buf: The buffer to place the result into
2913 * @size: The size of the buffer, including the trailing null space
2914 * @fmt: The format string to use
2915 * @...: Arguments for the format string
2916 *
2917 * The return value is the number of characters which would be
2918 * generated for the given input, excluding the trailing null,
2919 * as per ISO C99. If the return is greater than or equal to
2920 * @size, the resulting string is truncated.
2921 *
2922 * See the vsnprintf() documentation for format string extensions over C99.
2923 */
2924int snprintf(char *buf, size_t size, const char *fmt, ...)
2925{
2926 va_list args;
2927 int i;
2928
2929 va_start(args, fmt);
2930 i = vsnprintf(buf, size, fmt, args);
2931 va_end(args);
2932
2933 return i;
2934}
2935EXPORT_SYMBOL(snprintf);
2936
2937/**
2938 * scnprintf - Format a string and place it in a buffer
2939 * @buf: The buffer to place the result into
2940 * @size: The size of the buffer, including the trailing null space
2941 * @fmt: The format string to use
2942 * @...: Arguments for the format string
2943 *
2944 * The return value is the number of characters written into @buf not including
2945 * the trailing '\0'. If @size is == 0 the function returns 0.
2946 */
2947
2948int scnprintf(char *buf, size_t size, const char *fmt, ...)
2949{
2950 va_list args;
2951 int i;
2952
2953 va_start(args, fmt);
2954 i = vscnprintf(buf, size, fmt, args);
2955 va_end(args);
2956
2957 return i;
2958}
2959EXPORT_SYMBOL(scnprintf);
2960
2961/**
2962 * vsprintf - Format a string and place it in a buffer
2963 * @buf: The buffer to place the result into
2964 * @fmt: The format string to use
2965 * @args: Arguments for the format string
2966 *
2967 * The function returns the number of characters written
2968 * into @buf. Use vsnprintf() or vscnprintf() in order to avoid
2969 * buffer overflows.
2970 *
2971 * If you're not already dealing with a va_list consider using sprintf().
2972 *
2973 * See the vsnprintf() documentation for format string extensions over C99.
2974 */
2975int vsprintf(char *buf, const char *fmt, va_list args)
2976{
2977 return vsnprintf(buf, INT_MAX, fmt, args);
2978}
2979EXPORT_SYMBOL(vsprintf);
2980
2981/**
2982 * sprintf - Format a string and place it in a buffer
2983 * @buf: The buffer to place the result into
2984 * @fmt: The format string to use
2985 * @...: Arguments for the format string
2986 *
2987 * The function returns the number of characters written
2988 * into @buf. Use snprintf() or scnprintf() in order to avoid
2989 * buffer overflows.
2990 *
2991 * See the vsnprintf() documentation for format string extensions over C99.
2992 */
2993int sprintf(char *buf, const char *fmt, ...)
2994{
2995 va_list args;
2996 int i;
2997
2998 va_start(args, fmt);
2999 i = vsnprintf(buf, INT_MAX, fmt, args);
3000 va_end(args);
3001
3002 return i;
3003}
3004EXPORT_SYMBOL(sprintf);
3005
3006#ifdef CONFIG_BINARY_PRINTF
3007/*
3008 * bprintf service:
3009 * vbin_printf() - VA arguments to binary data
3010 * bstr_printf() - Binary data to text string
3011 */
3012
3013/**
3014 * vbin_printf - Parse a format string and place args' binary value in a buffer
3015 * @bin_buf: The buffer to place args' binary value
3016 * @size: The size of the buffer(by words(32bits), not characters)
3017 * @fmt: The format string to use
3018 * @args: Arguments for the format string
3019 *
3020 * The format follows C99 vsnprintf, except %n is ignored, and its argument
3021 * is skipped.
3022 *
3023 * The return value is the number of words(32bits) which would be generated for
3024 * the given input.
3025 *
3026 * NOTE:
3027 * If the return value is greater than @size, the resulting bin_buf is NOT
3028 * valid for bstr_printf().
3029 */
3030int vbin_printf(u32 *bin_buf, size_t size, const char *fmt, va_list args)
3031{
3032 struct printf_spec spec = {0};
3033 char *str, *end;
3034 int width;
3035
3036 str = (char *)bin_buf;
3037 end = (char *)(bin_buf + size);
3038
3039#define save_arg(type) \
3040({ \
3041 unsigned long long value; \
3042 if (sizeof(type) == 8) { \
3043 unsigned long long val8; \
3044 str = PTR_ALIGN(str, sizeof(u32)); \
3045 val8 = va_arg(args, unsigned long long); \
3046 if (str + sizeof(type) <= end) { \
3047 *(u32 *)str = *(u32 *)&val8; \
3048 *(u32 *)(str + 4) = *((u32 *)&val8 + 1); \
3049 } \
3050 value = val8; \
3051 } else { \
3052 unsigned int val4; \
3053 str = PTR_ALIGN(str, sizeof(type)); \
3054 val4 = va_arg(args, int); \
3055 if (str + sizeof(type) <= end) \
3056 *(typeof(type) *)str = (type)(long)val4; \
3057 value = (unsigned long long)val4; \
3058 } \
3059 str += sizeof(type); \
3060 value; \
3061})
3062
3063 while (*fmt) {
3064 int read = format_decode(fmt, &spec);
3065
3066 fmt += read;
3067
3068 switch (spec.type) {
3069 case FORMAT_TYPE_NONE:
3070 case FORMAT_TYPE_PERCENT_CHAR:
3071 break;
3072 case FORMAT_TYPE_INVALID:
3073 goto out;
3074
3075 case FORMAT_TYPE_WIDTH:
3076 case FORMAT_TYPE_PRECISION:
3077 width = (int)save_arg(int);
3078 /* Pointers may require the width */
3079 if (*fmt == 'p')
3080 set_field_width(&spec, width);
3081 break;
3082
3083 case FORMAT_TYPE_CHAR:
3084 save_arg(char);
3085 break;
3086
3087 case FORMAT_TYPE_STR: {
3088 const char *save_str = va_arg(args, char *);
3089 const char *err_msg;
3090 size_t len;
3091
3092 err_msg = check_pointer_msg(save_str);
3093 if (err_msg)
3094 save_str = err_msg;
3095
3096 len = strlen(save_str) + 1;
3097 if (str + len < end)
3098 memcpy(str, save_str, len);
3099 str += len;
3100 break;
3101 }
3102
3103 case FORMAT_TYPE_PTR:
3104 /* Dereferenced pointers must be done now */
3105 switch (*fmt) {
3106 /* Dereference of functions is still OK */
3107 case 'S':
3108 case 's':
3109 case 'x':
3110 case 'K':
3111 case 'e':
3112 save_arg(void *);
3113 break;
3114 default:
3115 if (!isalnum(*fmt)) {
3116 save_arg(void *);
3117 break;
3118 }
3119 str = pointer(fmt, str, end, va_arg(args, void *),
3120 spec);
3121 if (str + 1 < end)
3122 *str++ = '\0';
3123 else
3124 end[-1] = '\0'; /* Must be nul terminated */
3125 }
3126 /* skip all alphanumeric pointer suffixes */
3127 while (isalnum(*fmt))
3128 fmt++;
3129 break;
3130
3131 default:
3132 switch (spec.type) {
3133
3134 case FORMAT_TYPE_LONG_LONG:
3135 save_arg(long long);
3136 break;
3137 case FORMAT_TYPE_ULONG:
3138 case FORMAT_TYPE_LONG:
3139 save_arg(unsigned long);
3140 break;
3141 case FORMAT_TYPE_SIZE_T:
3142 save_arg(size_t);
3143 break;
3144 case FORMAT_TYPE_PTRDIFF:
3145 save_arg(ptrdiff_t);
3146 break;
3147 case FORMAT_TYPE_UBYTE:
3148 case FORMAT_TYPE_BYTE:
3149 save_arg(char);
3150 break;
3151 case FORMAT_TYPE_USHORT:
3152 case FORMAT_TYPE_SHORT:
3153 save_arg(short);
3154 break;
3155 default:
3156 save_arg(int);
3157 }
3158 }
3159 }
3160
3161out:
3162 return (u32 *)(PTR_ALIGN(str, sizeof(u32))) - bin_buf;
3163#undef save_arg
3164}
3165EXPORT_SYMBOL_GPL(vbin_printf);
3166
3167/**
3168 * bstr_printf - Format a string from binary arguments and place it in a buffer
3169 * @buf: The buffer to place the result into
3170 * @size: The size of the buffer, including the trailing null space
3171 * @fmt: The format string to use
3172 * @bin_buf: Binary arguments for the format string
3173 *
3174 * This function like C99 vsnprintf, but the difference is that vsnprintf gets
3175 * arguments from stack, and bstr_printf gets arguments from @bin_buf which is
3176 * a binary buffer that generated by vbin_printf.
3177 *
3178 * The format follows C99 vsnprintf, but has some extensions:
3179 * see vsnprintf comment for details.
3180 *
3181 * The return value is the number of characters which would
3182 * be generated for the given input, excluding the trailing
3183 * '\0', as per ISO C99. If you want to have the exact
3184 * number of characters written into @buf as return value
3185 * (not including the trailing '\0'), use vscnprintf(). If the
3186 * return is greater than or equal to @size, the resulting
3187 * string is truncated.
3188 */
3189int bstr_printf(char *buf, size_t size, const char *fmt, const u32 *bin_buf)
3190{
3191 struct printf_spec spec = {0};
3192 char *str, *end;
3193 const char *args = (const char *)bin_buf;
3194
3195 if (WARN_ON_ONCE(size > INT_MAX))
3196 return 0;
3197
3198 str = buf;
3199 end = buf + size;
3200
3201#define get_arg(type) \
3202({ \
3203 typeof(type) value; \
3204 if (sizeof(type) == 8) { \
3205 args = PTR_ALIGN(args, sizeof(u32)); \
3206 *(u32 *)&value = *(u32 *)args; \
3207 *((u32 *)&value + 1) = *(u32 *)(args + 4); \
3208 } else { \
3209 args = PTR_ALIGN(args, sizeof(type)); \
3210 value = *(typeof(type) *)args; \
3211 } \
3212 args += sizeof(type); \
3213 value; \
3214})
3215
3216 /* Make sure end is always >= buf */
3217 if (end < buf) {
3218 end = ((void *)-1);
3219 size = end - buf;
3220 }
3221
3222 while (*fmt) {
3223 const char *old_fmt = fmt;
3224 int read = format_decode(fmt, &spec);
3225
3226 fmt += read;
3227
3228 switch (spec.type) {
3229 case FORMAT_TYPE_NONE: {
3230 int copy = read;
3231 if (str < end) {
3232 if (copy > end - str)
3233 copy = end - str;
3234 memcpy(str, old_fmt, copy);
3235 }
3236 str += read;
3237 break;
3238 }
3239
3240 case FORMAT_TYPE_WIDTH:
3241 set_field_width(&spec, get_arg(int));
3242 break;
3243
3244 case FORMAT_TYPE_PRECISION:
3245 set_precision(&spec, get_arg(int));
3246 break;
3247
3248 case FORMAT_TYPE_CHAR: {
3249 char c;
3250
3251 if (!(spec.flags & LEFT)) {
3252 while (--spec.field_width > 0) {
3253 if (str < end)
3254 *str = ' ';
3255 ++str;
3256 }
3257 }
3258 c = (unsigned char) get_arg(char);
3259 if (str < end)
3260 *str = c;
3261 ++str;
3262 while (--spec.field_width > 0) {
3263 if (str < end)
3264 *str = ' ';
3265 ++str;
3266 }
3267 break;
3268 }
3269
3270 case FORMAT_TYPE_STR: {
3271 const char *str_arg = args;
3272 args += strlen(str_arg) + 1;
3273 str = string(str, end, (char *)str_arg, spec);
3274 break;
3275 }
3276
3277 case FORMAT_TYPE_PTR: {
3278 bool process = false;
3279 int copy, len;
3280 /* Non function dereferences were already done */
3281 switch (*fmt) {
3282 case 'S':
3283 case 's':
3284 case 'x':
3285 case 'K':
3286 case 'e':
3287 process = true;
3288 break;
3289 default:
3290 if (!isalnum(*fmt)) {
3291 process = true;
3292 break;
3293 }
3294 /* Pointer dereference was already processed */
3295 if (str < end) {
3296 len = copy = strlen(args);
3297 if (copy > end - str)
3298 copy = end - str;
3299 memcpy(str, args, copy);
3300 str += len;
3301 args += len + 1;
3302 }
3303 }
3304 if (process)
3305 str = pointer(fmt, str, end, get_arg(void *), spec);
3306
3307 while (isalnum(*fmt))
3308 fmt++;
3309 break;
3310 }
3311
3312 case FORMAT_TYPE_PERCENT_CHAR:
3313 if (str < end)
3314 *str = '%';
3315 ++str;
3316 break;
3317
3318 case FORMAT_TYPE_INVALID:
3319 goto out;
3320
3321 default: {
3322 unsigned long long num;
3323
3324 switch (spec.type) {
3325
3326 case FORMAT_TYPE_LONG_LONG:
3327 num = get_arg(long long);
3328 break;
3329 case FORMAT_TYPE_ULONG:
3330 case FORMAT_TYPE_LONG:
3331 num = get_arg(unsigned long);
3332 break;
3333 case FORMAT_TYPE_SIZE_T:
3334 num = get_arg(size_t);
3335 break;
3336 case FORMAT_TYPE_PTRDIFF:
3337 num = get_arg(ptrdiff_t);
3338 break;
3339 case FORMAT_TYPE_UBYTE:
3340 num = get_arg(unsigned char);
3341 break;
3342 case FORMAT_TYPE_BYTE:
3343 num = get_arg(signed char);
3344 break;
3345 case FORMAT_TYPE_USHORT:
3346 num = get_arg(unsigned short);
3347 break;
3348 case FORMAT_TYPE_SHORT:
3349 num = get_arg(short);
3350 break;
3351 case FORMAT_TYPE_UINT:
3352 num = get_arg(unsigned int);
3353 break;
3354 default:
3355 num = get_arg(int);
3356 }
3357
3358 str = number(str, end, num, spec);
3359 } /* default: */
3360 } /* switch(spec.type) */
3361 } /* while(*fmt) */
3362
3363out:
3364 if (size > 0) {
3365 if (str < end)
3366 *str = '\0';
3367 else
3368 end[-1] = '\0';
3369 }
3370
3371#undef get_arg
3372
3373 /* the trailing null byte doesn't count towards the total */
3374 return str - buf;
3375}
3376EXPORT_SYMBOL_GPL(bstr_printf);
3377
3378/**
3379 * bprintf - Parse a format string and place args' binary value in a buffer
3380 * @bin_buf: The buffer to place args' binary value
3381 * @size: The size of the buffer(by words(32bits), not characters)
3382 * @fmt: The format string to use
3383 * @...: Arguments for the format string
3384 *
3385 * The function returns the number of words(u32) written
3386 * into @bin_buf.
3387 */
3388int bprintf(u32 *bin_buf, size_t size, const char *fmt, ...)
3389{
3390 va_list args;
3391 int ret;
3392
3393 va_start(args, fmt);
3394 ret = vbin_printf(bin_buf, size, fmt, args);
3395 va_end(args);
3396
3397 return ret;
3398}
3399EXPORT_SYMBOL_GPL(bprintf);
3400
3401#endif /* CONFIG_BINARY_PRINTF */
3402
3403/**
3404 * vsscanf - Unformat a buffer into a list of arguments
3405 * @buf: input buffer
3406 * @fmt: format of buffer
3407 * @args: arguments
3408 */
3409int vsscanf(const char *buf, const char *fmt, va_list args)
3410{
3411 const char *str = buf;
3412 char *next;
3413 char digit;
3414 int num = 0;
3415 u8 qualifier;
3416 unsigned int base;
3417 union {
3418 long long s;
3419 unsigned long long u;
3420 } val;
3421 s16 field_width;
3422 bool is_sign;
3423
3424 while (*fmt) {
3425 /* skip any white space in format */
3426 /* white space in format matches any amount of
3427 * white space, including none, in the input.
3428 */
3429 if (isspace(*fmt)) {
3430 fmt = skip_spaces(++fmt);
3431 str = skip_spaces(str);
3432 }
3433
3434 /* anything that is not a conversion must match exactly */
3435 if (*fmt != '%' && *fmt) {
3436 if (*fmt++ != *str++)
3437 break;
3438 continue;
3439 }
3440
3441 if (!*fmt)
3442 break;
3443 ++fmt;
3444
3445 /* skip this conversion.
3446 * advance both strings to next white space
3447 */
3448 if (*fmt == '*') {
3449 if (!*str)
3450 break;
3451 while (!isspace(*fmt) && *fmt != '%' && *fmt) {
3452 /* '%*[' not yet supported, invalid format */
3453 if (*fmt == '[')
3454 return num;
3455 fmt++;
3456 }
3457 while (!isspace(*str) && *str)
3458 str++;
3459 continue;
3460 }
3461
3462 /* get field width */
3463 field_width = -1;
3464 if (isdigit(*fmt)) {
3465 field_width = skip_atoi(&fmt);
3466 if (field_width <= 0)
3467 break;
3468 }
3469
3470 /* get conversion qualifier */
3471 qualifier = -1;
3472 if (*fmt == 'h' || _tolower(*fmt) == 'l' ||
3473 *fmt == 'z') {
3474 qualifier = *fmt++;
3475 if (unlikely(qualifier == *fmt)) {
3476 if (qualifier == 'h') {
3477 qualifier = 'H';
3478 fmt++;
3479 } else if (qualifier == 'l') {
3480 qualifier = 'L';
3481 fmt++;
3482 }
3483 }
3484 }
3485
3486 if (!*fmt)
3487 break;
3488
3489 if (*fmt == 'n') {
3490 /* return number of characters read so far */
3491 *va_arg(args, int *) = str - buf;
3492 ++fmt;
3493 continue;
3494 }
3495
3496 if (!*str)
3497 break;
3498
3499 base = 10;
3500 is_sign = false;
3501
3502 switch (*fmt++) {
3503 case 'c':
3504 {
3505 char *s = (char *)va_arg(args, char*);
3506 if (field_width == -1)
3507 field_width = 1;
3508 do {
3509 *s++ = *str++;
3510 } while (--field_width > 0 && *str);
3511 num++;
3512 }
3513 continue;
3514 case 's':
3515 {
3516 char *s = (char *)va_arg(args, char *);
3517 if (field_width == -1)
3518 field_width = SHRT_MAX;
3519 /* first, skip leading white space in buffer */
3520 str = skip_spaces(str);
3521
3522 /* now copy until next white space */
3523 while (*str && !isspace(*str) && field_width--)
3524 *s++ = *str++;
3525 *s = '\0';
3526 num++;
3527 }
3528 continue;
3529 /*
3530 * Warning: This implementation of the '[' conversion specifier
3531 * deviates from its glibc counterpart in the following ways:
3532 * (1) It does NOT support ranges i.e. '-' is NOT a special
3533 * character
3534 * (2) It cannot match the closing bracket ']' itself
3535 * (3) A field width is required
3536 * (4) '%*[' (discard matching input) is currently not supported
3537 *
3538 * Example usage:
3539 * ret = sscanf("00:0a:95","%2[^:]:%2[^:]:%2[^:]",
3540 * buf1, buf2, buf3);
3541 * if (ret < 3)
3542 * // etc..
3543 */
3544 case '[':
3545 {
3546 char *s = (char *)va_arg(args, char *);
3547 DECLARE_BITMAP(set, 256) = {0};
3548 unsigned int len = 0;
3549 bool negate = (*fmt == '^');
3550
3551 /* field width is required */
3552 if (field_width == -1)
3553 return num;
3554
3555 if (negate)
3556 ++fmt;
3557
3558 for ( ; *fmt && *fmt != ']'; ++fmt, ++len)
3559 set_bit((u8)*fmt, set);
3560
3561 /* no ']' or no character set found */
3562 if (!*fmt || !len)
3563 return num;
3564 ++fmt;
3565
3566 if (negate) {
3567 bitmap_complement(set, set, 256);
3568 /* exclude null '\0' byte */
3569 clear_bit(0, set);
3570 }
3571
3572 /* match must be non-empty */
3573 if (!test_bit((u8)*str, set))
3574 return num;
3575
3576 while (test_bit((u8)*str, set) && field_width--)
3577 *s++ = *str++;
3578 *s = '\0';
3579 ++num;
3580 }
3581 continue;
3582 case 'o':
3583 base = 8;
3584 break;
3585 case 'x':
3586 case 'X':
3587 base = 16;
3588 break;
3589 case 'i':
3590 base = 0;
3591 fallthrough;
3592 case 'd':
3593 is_sign = true;
3594 fallthrough;
3595 case 'u':
3596 break;
3597 case '%':
3598 /* looking for '%' in str */
3599 if (*str++ != '%')
3600 return num;
3601 continue;
3602 default:
3603 /* invalid format; stop here */
3604 return num;
3605 }
3606
3607 /* have some sort of integer conversion.
3608 * first, skip white space in buffer.
3609 */
3610 str = skip_spaces(str);
3611
3612 digit = *str;
3613 if (is_sign && digit == '-') {
3614 if (field_width == 1)
3615 break;
3616
3617 digit = *(str + 1);
3618 }
3619
3620 if (!digit
3621 || (base == 16 && !isxdigit(digit))
3622 || (base == 10 && !isdigit(digit))
3623 || (base == 8 && (!isdigit(digit) || digit > '7'))
3624 || (base == 0 && !isdigit(digit)))
3625 break;
3626
3627 if (is_sign)
3628 val.s = simple_strntoll(str,
3629 field_width >= 0 ? field_width : INT_MAX,
3630 &next, base);
3631 else
3632 val.u = simple_strntoull(str,
3633 field_width >= 0 ? field_width : INT_MAX,
3634 &next, base);
3635
3636 switch (qualifier) {
3637 case 'H': /* that's 'hh' in format */
3638 if (is_sign)
3639 *va_arg(args, signed char *) = val.s;
3640 else
3641 *va_arg(args, unsigned char *) = val.u;
3642 break;
3643 case 'h':
3644 if (is_sign)
3645 *va_arg(args, short *) = val.s;
3646 else
3647 *va_arg(args, unsigned short *) = val.u;
3648 break;
3649 case 'l':
3650 if (is_sign)
3651 *va_arg(args, long *) = val.s;
3652 else
3653 *va_arg(args, unsigned long *) = val.u;
3654 break;
3655 case 'L':
3656 if (is_sign)
3657 *va_arg(args, long long *) = val.s;
3658 else
3659 *va_arg(args, unsigned long long *) = val.u;
3660 break;
3661 case 'z':
3662 *va_arg(args, size_t *) = val.u;
3663 break;
3664 default:
3665 if (is_sign)
3666 *va_arg(args, int *) = val.s;
3667 else
3668 *va_arg(args, unsigned int *) = val.u;
3669 break;
3670 }
3671 num++;
3672
3673 if (!next)
3674 break;
3675 str = next;
3676 }
3677
3678 return num;
3679}
3680EXPORT_SYMBOL(vsscanf);
3681
3682/**
3683 * sscanf - Unformat a buffer into a list of arguments
3684 * @buf: input buffer
3685 * @fmt: formatting of buffer
3686 * @...: resulting arguments
3687 */
3688int sscanf(const char *buf, const char *fmt, ...)
3689{
3690 va_list args;
3691 int i;
3692
3693 va_start(args, fmt);
3694 i = vsscanf(buf, fmt, args);
3695 va_end(args);
3696
3697 return i;
3698}
3699EXPORT_SYMBOL(sscanf);