1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * linux/lib/vsprintf.c
4 *
5 * Copyright (C) 1991, 1992 Linus Torvalds
6 */
7
8 /* vsprintf.c -- Lars Wirzenius & Linus Torvalds. */
9 /*
10 * Wirzenius wrote this portably, Torvalds fucked it up :-)
11 */
12
13 /*
14 * Fri Jul 13 2001 Crutcher Dunnavant <crutcher+kernel@datastacks.com>
15 * - changed to provide snprintf and vsnprintf functions
16 * So Feb 1 16:51:32 CET 2004 Juergen Quade <quade@hsnr.de>
17 * - scnprintf and vscnprintf
18 */
19
20 #include <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/sprintf.h>
38 #include <linux/time.h>
39 #include <linux/uuid.h>
40 #include <linux/of.h>
41 #include <net/addrconf.h>
42 #include <linux/siphash.h>
43 #include <linux/compiler.h>
44 #include <linux/property.h>
45 #include <linux/notifier.h>
46 #ifdef CONFIG_BLOCK
47 #include <linux/blkdev.h>
48 #endif
49
50 #include "../mm/internal.h" /* For the trace_print_flags arrays */
51
52 #include <asm/page.h> /* for PAGE_SIZE */
53 #include <asm/byteorder.h> /* cpu_to_le16 */
54 #include <asm/unaligned.h>
55
56 #include <linux/string_helpers.h>
57 #include "kstrtox.h"
58
59 /* Disable pointer hashing if requested */
60 bool no_hash_pointers __ro_after_init;
61 EXPORT_SYMBOL_GPL(no_hash_pointers);
62
simple_strntoull(const char * startp,size_t max_chars,char ** endp,unsigned int base)63 static noinline unsigned long long simple_strntoull(const char *startp, size_t max_chars, char **endp, unsigned int base)
64 {
65 const char *cp;
66 unsigned long long result = 0ULL;
67 size_t prefix_chars;
68 unsigned int rv;
69
70 cp = _parse_integer_fixup_radix(startp, &base);
71 prefix_chars = cp - startp;
72 if (prefix_chars < max_chars) {
73 rv = _parse_integer_limit(cp, base, &result, max_chars - prefix_chars);
74 /* FIXME */
75 cp += (rv & ~KSTRTOX_OVERFLOW);
76 } else {
77 /* Field too short for prefix + digit, skip over without converting */
78 cp = startp + max_chars;
79 }
80
81 if (endp)
82 *endp = (char *)cp;
83
84 return result;
85 }
86
87 /**
88 * simple_strtoull - convert a string to an unsigned long long
89 * @cp: The start of the string
90 * @endp: A pointer to the end of the parsed string will be placed here
91 * @base: The number base to use
92 *
93 * This function has caveats. Please use kstrtoull instead.
94 */
95 noinline
simple_strtoull(const char * cp,char ** endp,unsigned int base)96 unsigned long long simple_strtoull(const char *cp, char **endp, unsigned int base)
97 {
98 return simple_strntoull(cp, INT_MAX, endp, base);
99 }
100 EXPORT_SYMBOL(simple_strtoull);
101
102 /**
103 * simple_strtoul - convert a string to an unsigned long
104 * @cp: The start of the string
105 * @endp: A pointer to the end of the parsed string will be placed here
106 * @base: The number base to use
107 *
108 * This function has caveats. Please use kstrtoul instead.
109 */
simple_strtoul(const char * cp,char ** endp,unsigned int base)110 unsigned long simple_strtoul(const char *cp, char **endp, unsigned int base)
111 {
112 return simple_strtoull(cp, endp, base);
113 }
114 EXPORT_SYMBOL(simple_strtoul);
115
116 /**
117 * simple_strtol - convert a string to a signed long
118 * @cp: The start of the string
119 * @endp: A pointer to the end of the parsed string will be placed here
120 * @base: The number base to use
121 *
122 * This function has caveats. Please use kstrtol instead.
123 */
simple_strtol(const char * cp,char ** endp,unsigned int base)124 long simple_strtol(const char *cp, char **endp, unsigned int base)
125 {
126 if (*cp == '-')
127 return -simple_strtoul(cp + 1, endp, base);
128
129 return simple_strtoul(cp, endp, base);
130 }
131 EXPORT_SYMBOL(simple_strtol);
132
simple_strntoll(const char * cp,size_t max_chars,char ** endp,unsigned int base)133 static long long simple_strntoll(const char *cp, size_t max_chars, char **endp,
134 unsigned int base)
135 {
136 /*
137 * simple_strntoull() safely handles receiving max_chars==0 in the
138 * case cp[0] == '-' && max_chars == 1.
139 * If max_chars == 0 we can drop through and pass it to simple_strntoull()
140 * and the content of *cp is irrelevant.
141 */
142 if (*cp == '-' && max_chars > 0)
143 return -simple_strntoull(cp + 1, max_chars - 1, endp, base);
144
145 return simple_strntoull(cp, max_chars, endp, base);
146 }
147
148 /**
149 * simple_strtoll - convert a string to a signed long long
150 * @cp: The start of the string
151 * @endp: A pointer to the end of the parsed string will be placed here
152 * @base: The number base to use
153 *
154 * This function has caveats. Please use kstrtoll instead.
155 */
simple_strtoll(const char * cp,char ** endp,unsigned int base)156 long long simple_strtoll(const char *cp, char **endp, unsigned int base)
157 {
158 return simple_strntoll(cp, INT_MAX, endp, base);
159 }
160 EXPORT_SYMBOL(simple_strtoll);
161
162 static noinline_for_stack
skip_atoi(const char ** s)163 int skip_atoi(const char **s)
164 {
165 int i = 0;
166
167 do {
168 i = i*10 + *((*s)++) - '0';
169 } while (isdigit(**s));
170
171 return i;
172 }
173
174 /*
175 * Decimal conversion is by far the most typical, and is used for
176 * /proc and /sys data. This directly impacts e.g. top performance
177 * with many processes running. We optimize it for speed by emitting
178 * two characters at a time, using a 200 byte lookup table. This
179 * roughly halves the number of multiplications compared to computing
180 * the digits one at a time. Implementation strongly inspired by the
181 * previous version, which in turn used ideas described at
182 * <http://www.cs.uiowa.edu/~jones/bcd/divide.html> (with permission
183 * from the author, Douglas W. Jones).
184 *
185 * It turns out there is precisely one 26 bit fixed-point
186 * approximation a of 64/100 for which x/100 == (x * (u64)a) >> 32
187 * holds for all x in [0, 10^8-1], namely a = 0x28f5c29. The actual
188 * range happens to be somewhat larger (x <= 1073741898), but that's
189 * irrelevant for our purpose.
190 *
191 * For dividing a number in the range [10^4, 10^6-1] by 100, we still
192 * need a 32x32->64 bit multiply, so we simply use the same constant.
193 *
194 * For dividing a number in the range [100, 10^4-1] by 100, there are
195 * several options. The simplest is (x * 0x147b) >> 19, which is valid
196 * for all x <= 43698.
197 */
198
199 static const u16 decpair[100] = {
200 #define _(x) (__force u16) cpu_to_le16(((x % 10) | ((x / 10) << 8)) + 0x3030)
201 _( 0), _( 1), _( 2), _( 3), _( 4), _( 5), _( 6), _( 7), _( 8), _( 9),
202 _(10), _(11), _(12), _(13), _(14), _(15), _(16), _(17), _(18), _(19),
203 _(20), _(21), _(22), _(23), _(24), _(25), _(26), _(27), _(28), _(29),
204 _(30), _(31), _(32), _(33), _(34), _(35), _(36), _(37), _(38), _(39),
205 _(40), _(41), _(42), _(43), _(44), _(45), _(46), _(47), _(48), _(49),
206 _(50), _(51), _(52), _(53), _(54), _(55), _(56), _(57), _(58), _(59),
207 _(60), _(61), _(62), _(63), _(64), _(65), _(66), _(67), _(68), _(69),
208 _(70), _(71), _(72), _(73), _(74), _(75), _(76), _(77), _(78), _(79),
209 _(80), _(81), _(82), _(83), _(84), _(85), _(86), _(87), _(88), _(89),
210 _(90), _(91), _(92), _(93), _(94), _(95), _(96), _(97), _(98), _(99),
211 #undef _
212 };
213
214 /*
215 * This will print a single '0' even if r == 0, since we would
216 * immediately jump to out_r where two 0s would be written but only
217 * one of them accounted for in buf. This is needed by ip4_string
218 * below. All other callers pass a non-zero value of r.
219 */
220 static noinline_for_stack
put_dec_trunc8(char * buf,unsigned r)221 char *put_dec_trunc8(char *buf, unsigned r)
222 {
223 unsigned q;
224
225 /* 1 <= r < 10^8 */
226 if (r < 100)
227 goto out_r;
228
229 /* 100 <= r < 10^8 */
230 q = (r * (u64)0x28f5c29) >> 32;
231 *((u16 *)buf) = decpair[r - 100*q];
232 buf += 2;
233
234 /* 1 <= q < 10^6 */
235 if (q < 100)
236 goto out_q;
237
238 /* 100 <= q < 10^6 */
239 r = (q * (u64)0x28f5c29) >> 32;
240 *((u16 *)buf) = decpair[q - 100*r];
241 buf += 2;
242
243 /* 1 <= r < 10^4 */
244 if (r < 100)
245 goto out_r;
246
247 /* 100 <= r < 10^4 */
248 q = (r * 0x147b) >> 19;
249 *((u16 *)buf) = decpair[r - 100*q];
250 buf += 2;
251 out_q:
252 /* 1 <= q < 100 */
253 r = q;
254 out_r:
255 /* 1 <= r < 100 */
256 *((u16 *)buf) = decpair[r];
257 buf += r < 10 ? 1 : 2;
258 return buf;
259 }
260
261 #if BITS_PER_LONG == 64 && BITS_PER_LONG_LONG == 64
262 static noinline_for_stack
put_dec_full8(char * buf,unsigned r)263 char *put_dec_full8(char *buf, unsigned r)
264 {
265 unsigned q;
266
267 /* 0 <= r < 10^8 */
268 q = (r * (u64)0x28f5c29) >> 32;
269 *((u16 *)buf) = decpair[r - 100*q];
270 buf += 2;
271
272 /* 0 <= q < 10^6 */
273 r = (q * (u64)0x28f5c29) >> 32;
274 *((u16 *)buf) = decpair[q - 100*r];
275 buf += 2;
276
277 /* 0 <= r < 10^4 */
278 q = (r * 0x147b) >> 19;
279 *((u16 *)buf) = decpair[r - 100*q];
280 buf += 2;
281
282 /* 0 <= q < 100 */
283 *((u16 *)buf) = decpair[q];
284 buf += 2;
285 return buf;
286 }
287
288 static noinline_for_stack
put_dec(char * buf,unsigned long long n)289 char *put_dec(char *buf, unsigned long long n)
290 {
291 if (n >= 100*1000*1000)
292 buf = put_dec_full8(buf, do_div(n, 100*1000*1000));
293 /* 1 <= n <= 1.6e11 */
294 if (n >= 100*1000*1000)
295 buf = put_dec_full8(buf, do_div(n, 100*1000*1000));
296 /* 1 <= n < 1e8 */
297 return put_dec_trunc8(buf, n);
298 }
299
300 #elif BITS_PER_LONG == 32 && BITS_PER_LONG_LONG == 64
301
302 static void
put_dec_full4(char * buf,unsigned r)303 put_dec_full4(char *buf, unsigned r)
304 {
305 unsigned q;
306
307 /* 0 <= r < 10^4 */
308 q = (r * 0x147b) >> 19;
309 *((u16 *)buf) = decpair[r - 100*q];
310 buf += 2;
311 /* 0 <= q < 100 */
312 *((u16 *)buf) = decpair[q];
313 }
314
315 /*
316 * Call put_dec_full4 on x % 10000, return x / 10000.
317 * The approximation x/10000 == (x * 0x346DC5D7) >> 43
318 * holds for all x < 1,128,869,999. The largest value this
319 * helper will ever be asked to convert is 1,125,520,955.
320 * (second call in the put_dec code, assuming n is all-ones).
321 */
322 static noinline_for_stack
put_dec_helper4(char * buf,unsigned x)323 unsigned put_dec_helper4(char *buf, unsigned x)
324 {
325 uint32_t q = (x * (uint64_t)0x346DC5D7) >> 43;
326
327 put_dec_full4(buf, x - q * 10000);
328 return q;
329 }
330
331 /* Based on code by Douglas W. Jones found at
332 * <http://www.cs.uiowa.edu/~jones/bcd/decimal.html#sixtyfour>
333 * (with permission from the author).
334 * Performs no 64-bit division and hence should be fast on 32-bit machines.
335 */
336 static
put_dec(char * buf,unsigned long long n)337 char *put_dec(char *buf, unsigned long long n)
338 {
339 uint32_t d3, d2, d1, q, h;
340
341 if (n < 100*1000*1000)
342 return put_dec_trunc8(buf, n);
343
344 d1 = ((uint32_t)n >> 16); /* implicit "& 0xffff" */
345 h = (n >> 32);
346 d2 = (h ) & 0xffff;
347 d3 = (h >> 16); /* implicit "& 0xffff" */
348
349 /* n = 2^48 d3 + 2^32 d2 + 2^16 d1 + d0
350 = 281_4749_7671_0656 d3 + 42_9496_7296 d2 + 6_5536 d1 + d0 */
351 q = 656 * d3 + 7296 * d2 + 5536 * d1 + ((uint32_t)n & 0xffff);
352 q = put_dec_helper4(buf, q);
353
354 q += 7671 * d3 + 9496 * d2 + 6 * d1;
355 q = put_dec_helper4(buf+4, q);
356
357 q += 4749 * d3 + 42 * d2;
358 q = put_dec_helper4(buf+8, q);
359
360 q += 281 * d3;
361 buf += 12;
362 if (q)
363 buf = put_dec_trunc8(buf, q);
364 else while (buf[-1] == '0')
365 --buf;
366
367 return buf;
368 }
369
370 #endif
371
372 /*
373 * Convert passed number to decimal string.
374 * Returns the length of string. On buffer overflow, returns 0.
375 *
376 * If speed is not important, use snprintf(). It's easy to read the code.
377 */
num_to_str(char * buf,int size,unsigned long long num,unsigned int width)378 int num_to_str(char *buf, int size, unsigned long long num, unsigned int width)
379 {
380 /* put_dec requires 2-byte alignment of the buffer. */
381 char tmp[sizeof(num) * 3] __aligned(2);
382 int idx, len;
383
384 /* put_dec() may work incorrectly for num = 0 (generate "", not "0") */
385 if (num <= 9) {
386 tmp[0] = '0' + num;
387 len = 1;
388 } else {
389 len = put_dec(tmp, num) - tmp;
390 }
391
392 if (len > size || width > size)
393 return 0;
394
395 if (width > len) {
396 width = width - len;
397 for (idx = 0; idx < width; idx++)
398 buf[idx] = ' ';
399 } else {
400 width = 0;
401 }
402
403 for (idx = 0; idx < len; ++idx)
404 buf[idx + width] = tmp[len - idx - 1];
405
406 return len + width;
407 }
408
409 #define SIGN 1 /* unsigned/signed, must be 1 */
410 #define LEFT 2 /* left justified */
411 #define PLUS 4 /* show plus */
412 #define SPACE 8 /* space if plus */
413 #define ZEROPAD 16 /* pad with zero, must be 16 == '0' - ' ' */
414 #define SMALL 32 /* use lowercase in hex (must be 32 == 0x20) */
415 #define SPECIAL 64 /* prefix hex with "0x", octal with "0" */
416
417 static_assert(SIGN == 1);
418 static_assert(ZEROPAD == ('0' - ' '));
419 static_assert(SMALL == ('a' ^ 'A'));
420
421 enum format_type {
422 FORMAT_TYPE_NONE, /* Just a string part */
423 FORMAT_TYPE_WIDTH,
424 FORMAT_TYPE_PRECISION,
425 FORMAT_TYPE_CHAR,
426 FORMAT_TYPE_STR,
427 FORMAT_TYPE_PTR,
428 FORMAT_TYPE_PERCENT_CHAR,
429 FORMAT_TYPE_INVALID,
430 FORMAT_TYPE_LONG_LONG,
431 FORMAT_TYPE_ULONG,
432 FORMAT_TYPE_LONG,
433 FORMAT_TYPE_UBYTE,
434 FORMAT_TYPE_BYTE,
435 FORMAT_TYPE_USHORT,
436 FORMAT_TYPE_SHORT,
437 FORMAT_TYPE_UINT,
438 FORMAT_TYPE_INT,
439 FORMAT_TYPE_SIZE_T,
440 FORMAT_TYPE_PTRDIFF
441 };
442
443 struct printf_spec {
444 unsigned int type:8; /* format_type enum */
445 signed int field_width:24; /* width of output field */
446 unsigned int flags:8; /* flags to number() */
447 unsigned int base:8; /* number base, 8, 10 or 16 only */
448 signed int precision:16; /* # of digits/chars */
449 } __packed;
450 static_assert(sizeof(struct printf_spec) == 8);
451
452 #define FIELD_WIDTH_MAX ((1 << 23) - 1)
453 #define PRECISION_MAX ((1 << 15) - 1)
454
455 static noinline_for_stack
number(char * buf,char * end,unsigned long long num,struct printf_spec spec)456 char *number(char *buf, char *end, unsigned long long num,
457 struct printf_spec spec)
458 {
459 /* put_dec requires 2-byte alignment of the buffer. */
460 char tmp[3 * sizeof(num)] __aligned(2);
461 char sign;
462 char locase;
463 int need_pfx = ((spec.flags & SPECIAL) && spec.base != 10);
464 int i;
465 bool is_zero = num == 0LL;
466 int field_width = spec.field_width;
467 int precision = spec.precision;
468
469 /* locase = 0 or 0x20. ORing digits or letters with 'locase'
470 * produces same digits or (maybe lowercased) letters */
471 locase = (spec.flags & SMALL);
472 if (spec.flags & LEFT)
473 spec.flags &= ~ZEROPAD;
474 sign = 0;
475 if (spec.flags & SIGN) {
476 if ((signed long long)num < 0) {
477 sign = '-';
478 num = -(signed long long)num;
479 field_width--;
480 } else if (spec.flags & PLUS) {
481 sign = '+';
482 field_width--;
483 } else if (spec.flags & SPACE) {
484 sign = ' ';
485 field_width--;
486 }
487 }
488 if (need_pfx) {
489 if (spec.base == 16)
490 field_width -= 2;
491 else if (!is_zero)
492 field_width--;
493 }
494
495 /* generate full string in tmp[], in reverse order */
496 i = 0;
497 if (num < spec.base)
498 tmp[i++] = hex_asc_upper[num] | locase;
499 else if (spec.base != 10) { /* 8 or 16 */
500 int mask = spec.base - 1;
501 int shift = 3;
502
503 if (spec.base == 16)
504 shift = 4;
505 do {
506 tmp[i++] = (hex_asc_upper[((unsigned char)num) & mask] | locase);
507 num >>= shift;
508 } while (num);
509 } else { /* base 10 */
510 i = put_dec(tmp, num) - tmp;
511 }
512
513 /* printing 100 using %2d gives "100", not "00" */
514 if (i > precision)
515 precision = i;
516 /* leading space padding */
517 field_width -= precision;
518 if (!(spec.flags & (ZEROPAD | LEFT))) {
519 while (--field_width >= 0) {
520 if (buf < end)
521 *buf = ' ';
522 ++buf;
523 }
524 }
525 /* sign */
526 if (sign) {
527 if (buf < end)
528 *buf = sign;
529 ++buf;
530 }
531 /* "0x" / "0" prefix */
532 if (need_pfx) {
533 if (spec.base == 16 || !is_zero) {
534 if (buf < end)
535 *buf = '0';
536 ++buf;
537 }
538 if (spec.base == 16) {
539 if (buf < end)
540 *buf = ('X' | locase);
541 ++buf;
542 }
543 }
544 /* zero or space padding */
545 if (!(spec.flags & LEFT)) {
546 char c = ' ' + (spec.flags & ZEROPAD);
547
548 while (--field_width >= 0) {
549 if (buf < end)
550 *buf = c;
551 ++buf;
552 }
553 }
554 /* hmm even more zero padding? */
555 while (i <= --precision) {
556 if (buf < end)
557 *buf = '0';
558 ++buf;
559 }
560 /* actual digits of result */
561 while (--i >= 0) {
562 if (buf < end)
563 *buf = tmp[i];
564 ++buf;
565 }
566 /* trailing space padding */
567 while (--field_width >= 0) {
568 if (buf < end)
569 *buf = ' ';
570 ++buf;
571 }
572
573 return buf;
574 }
575
576 static noinline_for_stack
special_hex_number(char * buf,char * end,unsigned long long num,int size)577 char *special_hex_number(char *buf, char *end, unsigned long long num, int size)
578 {
579 struct printf_spec spec;
580
581 spec.type = FORMAT_TYPE_PTR;
582 spec.field_width = 2 + 2 * size; /* 0x + hex */
583 spec.flags = SPECIAL | SMALL | ZEROPAD;
584 spec.base = 16;
585 spec.precision = -1;
586
587 return number(buf, end, num, spec);
588 }
589
move_right(char * buf,char * end,unsigned len,unsigned spaces)590 static void move_right(char *buf, char *end, unsigned len, unsigned spaces)
591 {
592 size_t size;
593 if (buf >= end) /* nowhere to put anything */
594 return;
595 size = end - buf;
596 if (size <= spaces) {
597 memset(buf, ' ', size);
598 return;
599 }
600 if (len) {
601 if (len > size - spaces)
602 len = size - spaces;
603 memmove(buf + spaces, buf, len);
604 }
605 memset(buf, ' ', spaces);
606 }
607
608 /*
609 * Handle field width padding for a string.
610 * @buf: current buffer position
611 * @n: length of string
612 * @end: end of output buffer
613 * @spec: for field width and flags
614 * Returns: new buffer position after padding.
615 */
616 static noinline_for_stack
widen_string(char * buf,int n,char * end,struct printf_spec spec)617 char *widen_string(char *buf, int n, char *end, struct printf_spec spec)
618 {
619 unsigned spaces;
620
621 if (likely(n >= spec.field_width))
622 return buf;
623 /* we want to pad the sucker */
624 spaces = spec.field_width - n;
625 if (!(spec.flags & LEFT)) {
626 move_right(buf - n, end, n, spaces);
627 return buf + spaces;
628 }
629 while (spaces--) {
630 if (buf < end)
631 *buf = ' ';
632 ++buf;
633 }
634 return buf;
635 }
636
637 /* Handle string from a well known address. */
string_nocheck(char * buf,char * end,const char * s,struct printf_spec spec)638 static char *string_nocheck(char *buf, char *end, const char *s,
639 struct printf_spec spec)
640 {
641 int len = 0;
642 int lim = spec.precision;
643
644 while (lim--) {
645 char c = *s++;
646 if (!c)
647 break;
648 if (buf < end)
649 *buf = c;
650 ++buf;
651 ++len;
652 }
653 return widen_string(buf, len, end, spec);
654 }
655
err_ptr(char * buf,char * end,void * ptr,struct printf_spec spec)656 static char *err_ptr(char *buf, char *end, void *ptr,
657 struct printf_spec spec)
658 {
659 int err = PTR_ERR(ptr);
660 const char *sym = errname(err);
661
662 if (sym)
663 return string_nocheck(buf, end, sym, spec);
664
665 /*
666 * Somebody passed ERR_PTR(-1234) or some other non-existing
667 * Efoo - or perhaps CONFIG_SYMBOLIC_ERRNAME=n. Fall back to
668 * printing it as its decimal representation.
669 */
670 spec.flags |= SIGN;
671 spec.base = 10;
672 return number(buf, end, err, spec);
673 }
674
675 /* Be careful: error messages must fit into the given buffer. */
error_string(char * buf,char * end,const char * s,struct printf_spec spec)676 static char *error_string(char *buf, char *end, const char *s,
677 struct printf_spec spec)
678 {
679 /*
680 * Hard limit to avoid a completely insane messages. It actually
681 * works pretty well because most error messages are in
682 * the many pointer format modifiers.
683 */
684 if (spec.precision == -1)
685 spec.precision = 2 * sizeof(void *);
686
687 return string_nocheck(buf, end, s, spec);
688 }
689
690 /*
691 * Do not call any complex external code here. Nested printk()/vsprintf()
692 * might cause infinite loops. Failures might break printk() and would
693 * be hard to debug.
694 */
check_pointer_msg(const void * ptr)695 static const char *check_pointer_msg(const void *ptr)
696 {
697 if (!ptr)
698 return "(null)";
699
700 if ((unsigned long)ptr < PAGE_SIZE || IS_ERR_VALUE(ptr))
701 return "(efault)";
702
703 return NULL;
704 }
705
check_pointer(char ** buf,char * end,const void * ptr,struct printf_spec spec)706 static int check_pointer(char **buf, char *end, const void *ptr,
707 struct printf_spec spec)
708 {
709 const char *err_msg;
710
711 err_msg = check_pointer_msg(ptr);
712 if (err_msg) {
713 *buf = error_string(*buf, end, err_msg, spec);
714 return -EFAULT;
715 }
716
717 return 0;
718 }
719
720 static noinline_for_stack
string(char * buf,char * end,const char * s,struct printf_spec spec)721 char *string(char *buf, char *end, const char *s,
722 struct printf_spec spec)
723 {
724 if (check_pointer(&buf, end, s, spec))
725 return buf;
726
727 return string_nocheck(buf, end, s, spec);
728 }
729
pointer_string(char * buf,char * end,const void * ptr,struct printf_spec spec)730 static char *pointer_string(char *buf, char *end,
731 const void *ptr,
732 struct printf_spec spec)
733 {
734 spec.base = 16;
735 spec.flags |= SMALL;
736 if (spec.field_width == -1) {
737 spec.field_width = 2 * sizeof(ptr);
738 spec.flags |= ZEROPAD;
739 }
740
741 return number(buf, end, (unsigned long int)ptr, spec);
742 }
743
744 /* Make pointers available for printing early in the boot sequence. */
745 static int debug_boot_weak_hash __ro_after_init;
746
debug_boot_weak_hash_enable(char * str)747 static int __init debug_boot_weak_hash_enable(char *str)
748 {
749 debug_boot_weak_hash = 1;
750 pr_info("debug_boot_weak_hash enabled\n");
751 return 0;
752 }
753 early_param("debug_boot_weak_hash", debug_boot_weak_hash_enable);
754
755 static bool filled_random_ptr_key __read_mostly;
756 static siphash_key_t ptr_key __read_mostly;
757
fill_ptr_key(struct notifier_block * nb,unsigned long action,void * data)758 static int fill_ptr_key(struct notifier_block *nb, unsigned long action, void *data)
759 {
760 get_random_bytes(&ptr_key, sizeof(ptr_key));
761
762 /* Pairs with smp_rmb() before reading ptr_key. */
763 smp_wmb();
764 WRITE_ONCE(filled_random_ptr_key, true);
765 return NOTIFY_DONE;
766 }
767
vsprintf_init_hashval(void)768 static int __init vsprintf_init_hashval(void)
769 {
770 static struct notifier_block fill_ptr_key_nb = { .notifier_call = fill_ptr_key };
771 execute_with_initialized_rng(&fill_ptr_key_nb);
772 return 0;
773 }
subsys_initcall(vsprintf_init_hashval)774 subsys_initcall(vsprintf_init_hashval)
775
776 /* Maps a pointer to a 32 bit unique identifier. */
777 static inline int __ptr_to_hashval(const void *ptr, unsigned long *hashval_out)
778 {
779 unsigned long hashval;
780
781 if (!READ_ONCE(filled_random_ptr_key))
782 return -EBUSY;
783
784 /* Pairs with smp_wmb() after writing ptr_key. */
785 smp_rmb();
786
787 #ifdef CONFIG_64BIT
788 hashval = (unsigned long)siphash_1u64((u64)ptr, &ptr_key);
789 /*
790 * Mask off the first 32 bits, this makes explicit that we have
791 * modified the address (and 32 bits is plenty for a unique ID).
792 */
793 hashval = hashval & 0xffffffff;
794 #else
795 hashval = (unsigned long)siphash_1u32((u32)ptr, &ptr_key);
796 #endif
797 *hashval_out = hashval;
798 return 0;
799 }
800
ptr_to_hashval(const void * ptr,unsigned long * hashval_out)801 int ptr_to_hashval(const void *ptr, unsigned long *hashval_out)
802 {
803 return __ptr_to_hashval(ptr, hashval_out);
804 }
805
ptr_to_id(char * buf,char * end,const void * ptr,struct printf_spec spec)806 static char *ptr_to_id(char *buf, char *end, const void *ptr,
807 struct printf_spec spec)
808 {
809 const char *str = sizeof(ptr) == 8 ? "(____ptrval____)" : "(ptrval)";
810 unsigned long hashval;
811 int ret;
812
813 /*
814 * Print the real pointer value for NULL and error pointers,
815 * as they are not actual addresses.
816 */
817 if (IS_ERR_OR_NULL(ptr))
818 return pointer_string(buf, end, ptr, spec);
819
820 /* When debugging early boot use non-cryptographically secure hash. */
821 if (unlikely(debug_boot_weak_hash)) {
822 hashval = hash_long((unsigned long)ptr, 32);
823 return pointer_string(buf, end, (const void *)hashval, spec);
824 }
825
826 ret = __ptr_to_hashval(ptr, &hashval);
827 if (ret) {
828 spec.field_width = 2 * sizeof(ptr);
829 /* string length must be less than default_width */
830 return error_string(buf, end, str, spec);
831 }
832
833 return pointer_string(buf, end, (const void *)hashval, spec);
834 }
835
default_pointer(char * buf,char * end,const void * ptr,struct printf_spec spec)836 static char *default_pointer(char *buf, char *end, const void *ptr,
837 struct printf_spec spec)
838 {
839 /*
840 * default is to _not_ leak addresses, so hash before printing,
841 * unless no_hash_pointers is specified on the command line.
842 */
843 if (unlikely(no_hash_pointers))
844 return pointer_string(buf, end, ptr, spec);
845
846 return ptr_to_id(buf, end, ptr, spec);
847 }
848
849 int kptr_restrict __read_mostly;
850
851 static noinline_for_stack
restricted_pointer(char * buf,char * end,const void * ptr,struct printf_spec spec)852 char *restricted_pointer(char *buf, char *end, const void *ptr,
853 struct printf_spec spec)
854 {
855 switch (kptr_restrict) {
856 case 0:
857 /* Handle as %p, hash and do _not_ leak addresses. */
858 return default_pointer(buf, end, ptr, spec);
859 case 1: {
860 const struct cred *cred;
861
862 /*
863 * kptr_restrict==1 cannot be used in IRQ context
864 * because its test for CAP_SYSLOG would be meaningless.
865 */
866 if (in_hardirq() || in_serving_softirq() || in_nmi()) {
867 if (spec.field_width == -1)
868 spec.field_width = 2 * sizeof(ptr);
869 return error_string(buf, end, "pK-error", spec);
870 }
871
872 /*
873 * Only print the real pointer value if the current
874 * process has CAP_SYSLOG and is running with the
875 * same credentials it started with. This is because
876 * access to files is checked at open() time, but %pK
877 * checks permission at read() time. We don't want to
878 * leak pointer values if a binary opens a file using
879 * %pK and then elevates privileges before reading it.
880 */
881 cred = current_cred();
882 if (!has_capability_noaudit(current, CAP_SYSLOG) ||
883 !uid_eq(cred->euid, cred->uid) ||
884 !gid_eq(cred->egid, cred->gid))
885 ptr = NULL;
886 break;
887 }
888 case 2:
889 default:
890 /* Always print 0's for %pK */
891 ptr = NULL;
892 break;
893 }
894
895 return pointer_string(buf, end, ptr, spec);
896 }
897
898 static noinline_for_stack
dentry_name(char * buf,char * end,const struct dentry * d,struct printf_spec spec,const char * fmt)899 char *dentry_name(char *buf, char *end, const struct dentry *d, struct printf_spec spec,
900 const char *fmt)
901 {
902 const char *array[4], *s;
903 const struct dentry *p;
904 int depth;
905 int i, n;
906
907 switch (fmt[1]) {
908 case '2': case '3': case '4':
909 depth = fmt[1] - '0';
910 break;
911 default:
912 depth = 1;
913 }
914
915 rcu_read_lock();
916 for (i = 0; i < depth; i++, d = p) {
917 if (check_pointer(&buf, end, d, spec)) {
918 rcu_read_unlock();
919 return buf;
920 }
921
922 p = READ_ONCE(d->d_parent);
923 array[i] = READ_ONCE(d->d_name.name);
924 if (p == d) {
925 if (i)
926 array[i] = "";
927 i++;
928 break;
929 }
930 }
931 s = array[--i];
932 for (n = 0; n != spec.precision; n++, buf++) {
933 char c = *s++;
934 if (!c) {
935 if (!i)
936 break;
937 c = '/';
938 s = array[--i];
939 }
940 if (buf < end)
941 *buf = c;
942 }
943 rcu_read_unlock();
944 return widen_string(buf, n, end, spec);
945 }
946
947 static noinline_for_stack
file_dentry_name(char * buf,char * end,const struct file * f,struct printf_spec spec,const char * fmt)948 char *file_dentry_name(char *buf, char *end, const struct file *f,
949 struct printf_spec spec, const char *fmt)
950 {
951 if (check_pointer(&buf, end, f, spec))
952 return buf;
953
954 return dentry_name(buf, end, f->f_path.dentry, spec, fmt);
955 }
956 #ifdef CONFIG_BLOCK
957 static noinline_for_stack
bdev_name(char * buf,char * end,struct block_device * bdev,struct printf_spec spec,const char * fmt)958 char *bdev_name(char *buf, char *end, struct block_device *bdev,
959 struct printf_spec spec, const char *fmt)
960 {
961 struct gendisk *hd;
962
963 if (check_pointer(&buf, end, bdev, spec))
964 return buf;
965
966 hd = bdev->bd_disk;
967 buf = string(buf, end, hd->disk_name, spec);
968 if (bdev->bd_partno) {
969 if (isdigit(hd->disk_name[strlen(hd->disk_name)-1])) {
970 if (buf < end)
971 *buf = 'p';
972 buf++;
973 }
974 buf = number(buf, end, bdev->bd_partno, spec);
975 }
976 return buf;
977 }
978 #endif
979
980 static noinline_for_stack
symbol_string(char * buf,char * end,void * ptr,struct printf_spec spec,const char * fmt)981 char *symbol_string(char *buf, char *end, void *ptr,
982 struct printf_spec spec, const char *fmt)
983 {
984 unsigned long value;
985 #ifdef CONFIG_KALLSYMS
986 char sym[KSYM_SYMBOL_LEN];
987 #endif
988
989 if (fmt[1] == 'R')
990 ptr = __builtin_extract_return_addr(ptr);
991 value = (unsigned long)ptr;
992
993 #ifdef CONFIG_KALLSYMS
994 if (*fmt == 'B' && fmt[1] == 'b')
995 sprint_backtrace_build_id(sym, value);
996 else if (*fmt == 'B')
997 sprint_backtrace(sym, value);
998 else if (*fmt == 'S' && (fmt[1] == 'b' || (fmt[1] == 'R' && fmt[2] == 'b')))
999 sprint_symbol_build_id(sym, value);
1000 else if (*fmt != 's')
1001 sprint_symbol(sym, value);
1002 else
1003 sprint_symbol_no_offset(sym, value);
1004
1005 return string_nocheck(buf, end, sym, spec);
1006 #else
1007 return special_hex_number(buf, end, value, sizeof(void *));
1008 #endif
1009 }
1010
1011 static const struct printf_spec default_str_spec = {
1012 .field_width = -1,
1013 .precision = -1,
1014 };
1015
1016 static const struct printf_spec default_flag_spec = {
1017 .base = 16,
1018 .precision = -1,
1019 .flags = SPECIAL | SMALL,
1020 };
1021
1022 static const struct printf_spec default_dec_spec = {
1023 .base = 10,
1024 .precision = -1,
1025 };
1026
1027 static const struct printf_spec default_dec02_spec = {
1028 .base = 10,
1029 .field_width = 2,
1030 .precision = -1,
1031 .flags = ZEROPAD,
1032 };
1033
1034 static const struct printf_spec default_dec04_spec = {
1035 .base = 10,
1036 .field_width = 4,
1037 .precision = -1,
1038 .flags = ZEROPAD,
1039 };
1040
1041 static noinline_for_stack
resource_string(char * buf,char * end,struct resource * res,struct printf_spec spec,const char * fmt)1042 char *resource_string(char *buf, char *end, struct resource *res,
1043 struct printf_spec spec, const char *fmt)
1044 {
1045 #ifndef IO_RSRC_PRINTK_SIZE
1046 #define IO_RSRC_PRINTK_SIZE 6
1047 #endif
1048
1049 #ifndef MEM_RSRC_PRINTK_SIZE
1050 #define MEM_RSRC_PRINTK_SIZE 10
1051 #endif
1052 static const struct printf_spec io_spec = {
1053 .base = 16,
1054 .field_width = IO_RSRC_PRINTK_SIZE,
1055 .precision = -1,
1056 .flags = SPECIAL | SMALL | ZEROPAD,
1057 };
1058 static const struct printf_spec mem_spec = {
1059 .base = 16,
1060 .field_width = MEM_RSRC_PRINTK_SIZE,
1061 .precision = -1,
1062 .flags = SPECIAL | SMALL | ZEROPAD,
1063 };
1064 static const struct printf_spec bus_spec = {
1065 .base = 16,
1066 .field_width = 2,
1067 .precision = -1,
1068 .flags = SMALL | ZEROPAD,
1069 };
1070 static const struct printf_spec str_spec = {
1071 .field_width = -1,
1072 .precision = 10,
1073 .flags = LEFT,
1074 };
1075
1076 /* 32-bit res (sizeof==4): 10 chars in dec, 10 in hex ("0x" + 8)
1077 * 64-bit res (sizeof==8): 20 chars in dec, 18 in hex ("0x" + 16) */
1078 #define RSRC_BUF_SIZE ((2 * sizeof(resource_size_t)) + 4)
1079 #define FLAG_BUF_SIZE (2 * sizeof(res->flags))
1080 #define DECODED_BUF_SIZE sizeof("[mem - 64bit pref window disabled]")
1081 #define RAW_BUF_SIZE sizeof("[mem - flags 0x]")
1082 char sym[max(2*RSRC_BUF_SIZE + DECODED_BUF_SIZE,
1083 2*RSRC_BUF_SIZE + FLAG_BUF_SIZE + RAW_BUF_SIZE)];
1084
1085 char *p = sym, *pend = sym + sizeof(sym);
1086 int decode = (fmt[0] == 'R') ? 1 : 0;
1087 const struct printf_spec *specp;
1088
1089 if (check_pointer(&buf, end, res, spec))
1090 return buf;
1091
1092 *p++ = '[';
1093 if (res->flags & IORESOURCE_IO) {
1094 p = string_nocheck(p, pend, "io ", str_spec);
1095 specp = &io_spec;
1096 } else if (res->flags & IORESOURCE_MEM) {
1097 p = string_nocheck(p, pend, "mem ", str_spec);
1098 specp = &mem_spec;
1099 } else if (res->flags & IORESOURCE_IRQ) {
1100 p = string_nocheck(p, pend, "irq ", str_spec);
1101 specp = &default_dec_spec;
1102 } else if (res->flags & IORESOURCE_DMA) {
1103 p = string_nocheck(p, pend, "dma ", str_spec);
1104 specp = &default_dec_spec;
1105 } else if (res->flags & IORESOURCE_BUS) {
1106 p = string_nocheck(p, pend, "bus ", str_spec);
1107 specp = &bus_spec;
1108 } else {
1109 p = string_nocheck(p, pend, "??? ", str_spec);
1110 specp = &mem_spec;
1111 decode = 0;
1112 }
1113 if (decode && res->flags & IORESOURCE_UNSET) {
1114 p = string_nocheck(p, pend, "size ", str_spec);
1115 p = number(p, pend, resource_size(res), *specp);
1116 } else {
1117 p = number(p, pend, res->start, *specp);
1118 if (res->start != res->end) {
1119 *p++ = '-';
1120 p = number(p, pend, res->end, *specp);
1121 }
1122 }
1123 if (decode) {
1124 if (res->flags & IORESOURCE_MEM_64)
1125 p = string_nocheck(p, pend, " 64bit", str_spec);
1126 if (res->flags & IORESOURCE_PREFETCH)
1127 p = string_nocheck(p, pend, " pref", str_spec);
1128 if (res->flags & IORESOURCE_WINDOW)
1129 p = string_nocheck(p, pend, " window", str_spec);
1130 if (res->flags & IORESOURCE_DISABLED)
1131 p = string_nocheck(p, pend, " disabled", str_spec);
1132 } else {
1133 p = string_nocheck(p, pend, " flags ", str_spec);
1134 p = number(p, pend, res->flags, default_flag_spec);
1135 }
1136 *p++ = ']';
1137 *p = '\0';
1138
1139 return string_nocheck(buf, end, sym, spec);
1140 }
1141
1142 static noinline_for_stack
hex_string(char * buf,char * end,u8 * addr,struct printf_spec spec,const char * fmt)1143 char *hex_string(char *buf, char *end, u8 *addr, struct printf_spec spec,
1144 const char *fmt)
1145 {
1146 int i, len = 1; /* if we pass '%ph[CDN]', field width remains
1147 negative value, fallback to the default */
1148 char separator;
1149
1150 if (spec.field_width == 0)
1151 /* nothing to print */
1152 return buf;
1153
1154 if (check_pointer(&buf, end, addr, spec))
1155 return buf;
1156
1157 switch (fmt[1]) {
1158 case 'C':
1159 separator = ':';
1160 break;
1161 case 'D':
1162 separator = '-';
1163 break;
1164 case 'N':
1165 separator = 0;
1166 break;
1167 default:
1168 separator = ' ';
1169 break;
1170 }
1171
1172 if (spec.field_width > 0)
1173 len = min_t(int, spec.field_width, 64);
1174
1175 for (i = 0; i < len; ++i) {
1176 if (buf < end)
1177 *buf = hex_asc_hi(addr[i]);
1178 ++buf;
1179 if (buf < end)
1180 *buf = hex_asc_lo(addr[i]);
1181 ++buf;
1182
1183 if (separator && i != len - 1) {
1184 if (buf < end)
1185 *buf = separator;
1186 ++buf;
1187 }
1188 }
1189
1190 return buf;
1191 }
1192
1193 static noinline_for_stack
bitmap_string(char * buf,char * end,const unsigned long * bitmap,struct printf_spec spec,const char * fmt)1194 char *bitmap_string(char *buf, char *end, const unsigned long *bitmap,
1195 struct printf_spec spec, const char *fmt)
1196 {
1197 const int CHUNKSZ = 32;
1198 int nr_bits = max_t(int, spec.field_width, 0);
1199 int i, chunksz;
1200 bool first = true;
1201
1202 if (check_pointer(&buf, end, bitmap, spec))
1203 return buf;
1204
1205 /* reused to print numbers */
1206 spec = (struct printf_spec){ .flags = SMALL | ZEROPAD, .base = 16 };
1207
1208 chunksz = nr_bits & (CHUNKSZ - 1);
1209 if (chunksz == 0)
1210 chunksz = CHUNKSZ;
1211
1212 i = ALIGN(nr_bits, CHUNKSZ) - CHUNKSZ;
1213 for (; i >= 0; i -= CHUNKSZ) {
1214 u32 chunkmask, val;
1215 int word, bit;
1216
1217 chunkmask = ((1ULL << chunksz) - 1);
1218 word = i / BITS_PER_LONG;
1219 bit = i % BITS_PER_LONG;
1220 val = (bitmap[word] >> bit) & chunkmask;
1221
1222 if (!first) {
1223 if (buf < end)
1224 *buf = ',';
1225 buf++;
1226 }
1227 first = false;
1228
1229 spec.field_width = DIV_ROUND_UP(chunksz, 4);
1230 buf = number(buf, end, val, spec);
1231
1232 chunksz = CHUNKSZ;
1233 }
1234 return buf;
1235 }
1236
1237 static noinline_for_stack
bitmap_list_string(char * buf,char * end,const unsigned long * bitmap,struct printf_spec spec,const char * fmt)1238 char *bitmap_list_string(char *buf, char *end, const unsigned long *bitmap,
1239 struct printf_spec spec, const char *fmt)
1240 {
1241 int nr_bits = max_t(int, spec.field_width, 0);
1242 bool first = true;
1243 int rbot, rtop;
1244
1245 if (check_pointer(&buf, end, bitmap, spec))
1246 return buf;
1247
1248 for_each_set_bitrange(rbot, rtop, bitmap, nr_bits) {
1249 if (!first) {
1250 if (buf < end)
1251 *buf = ',';
1252 buf++;
1253 }
1254 first = false;
1255
1256 buf = number(buf, end, rbot, default_dec_spec);
1257 if (rtop == rbot + 1)
1258 continue;
1259
1260 if (buf < end)
1261 *buf = '-';
1262 buf = number(++buf, end, rtop - 1, default_dec_spec);
1263 }
1264 return buf;
1265 }
1266
1267 static noinline_for_stack
mac_address_string(char * buf,char * end,u8 * addr,struct printf_spec spec,const char * fmt)1268 char *mac_address_string(char *buf, char *end, u8 *addr,
1269 struct printf_spec spec, const char *fmt)
1270 {
1271 char mac_addr[sizeof("xx:xx:xx:xx:xx:xx")];
1272 char *p = mac_addr;
1273 int i;
1274 char separator;
1275 bool reversed = false;
1276
1277 if (check_pointer(&buf, end, addr, spec))
1278 return buf;
1279
1280 switch (fmt[1]) {
1281 case 'F':
1282 separator = '-';
1283 break;
1284
1285 case 'R':
1286 reversed = true;
1287 fallthrough;
1288
1289 default:
1290 separator = ':';
1291 break;
1292 }
1293
1294 for (i = 0; i < 6; i++) {
1295 if (reversed)
1296 p = hex_byte_pack(p, addr[5 - i]);
1297 else
1298 p = hex_byte_pack(p, addr[i]);
1299
1300 if (fmt[0] == 'M' && i != 5)
1301 *p++ = separator;
1302 }
1303 *p = '\0';
1304
1305 return string_nocheck(buf, end, mac_addr, spec);
1306 }
1307
1308 static noinline_for_stack
ip4_string(char * p,const u8 * addr,const char * fmt)1309 char *ip4_string(char *p, const u8 *addr, const char *fmt)
1310 {
1311 int i;
1312 bool leading_zeros = (fmt[0] == 'i');
1313 int index;
1314 int step;
1315
1316 switch (fmt[2]) {
1317 case 'h':
1318 #ifdef __BIG_ENDIAN
1319 index = 0;
1320 step = 1;
1321 #else
1322 index = 3;
1323 step = -1;
1324 #endif
1325 break;
1326 case 'l':
1327 index = 3;
1328 step = -1;
1329 break;
1330 case 'n':
1331 case 'b':
1332 default:
1333 index = 0;
1334 step = 1;
1335 break;
1336 }
1337 for (i = 0; i < 4; i++) {
1338 char temp[4] __aligned(2); /* hold each IP quad in reverse order */
1339 int digits = put_dec_trunc8(temp, addr[index]) - temp;
1340 if (leading_zeros) {
1341 if (digits < 3)
1342 *p++ = '0';
1343 if (digits < 2)
1344 *p++ = '0';
1345 }
1346 /* reverse the digits in the quad */
1347 while (digits--)
1348 *p++ = temp[digits];
1349 if (i < 3)
1350 *p++ = '.';
1351 index += step;
1352 }
1353 *p = '\0';
1354
1355 return p;
1356 }
1357
1358 static noinline_for_stack
ip6_compressed_string(char * p,const char * addr)1359 char *ip6_compressed_string(char *p, const char *addr)
1360 {
1361 int i, j, range;
1362 unsigned char zerolength[8];
1363 int longest = 1;
1364 int colonpos = -1;
1365 u16 word;
1366 u8 hi, lo;
1367 bool needcolon = false;
1368 bool useIPv4;
1369 struct in6_addr in6;
1370
1371 memcpy(&in6, addr, sizeof(struct in6_addr));
1372
1373 useIPv4 = ipv6_addr_v4mapped(&in6) || ipv6_addr_is_isatap(&in6);
1374
1375 memset(zerolength, 0, sizeof(zerolength));
1376
1377 if (useIPv4)
1378 range = 6;
1379 else
1380 range = 8;
1381
1382 /* find position of longest 0 run */
1383 for (i = 0; i < range; i++) {
1384 for (j = i; j < range; j++) {
1385 if (in6.s6_addr16[j] != 0)
1386 break;
1387 zerolength[i]++;
1388 }
1389 }
1390 for (i = 0; i < range; i++) {
1391 if (zerolength[i] > longest) {
1392 longest = zerolength[i];
1393 colonpos = i;
1394 }
1395 }
1396 if (longest == 1) /* don't compress a single 0 */
1397 colonpos = -1;
1398
1399 /* emit address */
1400 for (i = 0; i < range; i++) {
1401 if (i == colonpos) {
1402 if (needcolon || i == 0)
1403 *p++ = ':';
1404 *p++ = ':';
1405 needcolon = false;
1406 i += longest - 1;
1407 continue;
1408 }
1409 if (needcolon) {
1410 *p++ = ':';
1411 needcolon = false;
1412 }
1413 /* hex u16 without leading 0s */
1414 word = ntohs(in6.s6_addr16[i]);
1415 hi = word >> 8;
1416 lo = word & 0xff;
1417 if (hi) {
1418 if (hi > 0x0f)
1419 p = hex_byte_pack(p, hi);
1420 else
1421 *p++ = hex_asc_lo(hi);
1422 p = hex_byte_pack(p, lo);
1423 }
1424 else if (lo > 0x0f)
1425 p = hex_byte_pack(p, lo);
1426 else
1427 *p++ = hex_asc_lo(lo);
1428 needcolon = true;
1429 }
1430
1431 if (useIPv4) {
1432 if (needcolon)
1433 *p++ = ':';
1434 p = ip4_string(p, &in6.s6_addr[12], "I4");
1435 }
1436 *p = '\0';
1437
1438 return p;
1439 }
1440
1441 static noinline_for_stack
ip6_string(char * p,const char * addr,const char * fmt)1442 char *ip6_string(char *p, const char *addr, const char *fmt)
1443 {
1444 int i;
1445
1446 for (i = 0; i < 8; i++) {
1447 p = hex_byte_pack(p, *addr++);
1448 p = hex_byte_pack(p, *addr++);
1449 if (fmt[0] == 'I' && i != 7)
1450 *p++ = ':';
1451 }
1452 *p = '\0';
1453
1454 return p;
1455 }
1456
1457 static noinline_for_stack
ip6_addr_string(char * buf,char * end,const u8 * addr,struct printf_spec spec,const char * fmt)1458 char *ip6_addr_string(char *buf, char *end, const u8 *addr,
1459 struct printf_spec spec, const char *fmt)
1460 {
1461 char ip6_addr[sizeof("xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255")];
1462
1463 if (fmt[0] == 'I' && fmt[2] == 'c')
1464 ip6_compressed_string(ip6_addr, addr);
1465 else
1466 ip6_string(ip6_addr, addr, fmt);
1467
1468 return string_nocheck(buf, end, ip6_addr, spec);
1469 }
1470
1471 static noinline_for_stack
ip4_addr_string(char * buf,char * end,const u8 * addr,struct printf_spec spec,const char * fmt)1472 char *ip4_addr_string(char *buf, char *end, const u8 *addr,
1473 struct printf_spec spec, const char *fmt)
1474 {
1475 char ip4_addr[sizeof("255.255.255.255")];
1476
1477 ip4_string(ip4_addr, addr, fmt);
1478
1479 return string_nocheck(buf, end, ip4_addr, spec);
1480 }
1481
1482 static noinline_for_stack
ip6_addr_string_sa(char * buf,char * end,const struct sockaddr_in6 * sa,struct printf_spec spec,const char * fmt)1483 char *ip6_addr_string_sa(char *buf, char *end, const struct sockaddr_in6 *sa,
1484 struct printf_spec spec, const char *fmt)
1485 {
1486 bool have_p = false, have_s = false, have_f = false, have_c = false;
1487 char ip6_addr[sizeof("[xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255]") +
1488 sizeof(":12345") + sizeof("/123456789") +
1489 sizeof("%1234567890")];
1490 char *p = ip6_addr, *pend = ip6_addr + sizeof(ip6_addr);
1491 const u8 *addr = (const u8 *) &sa->sin6_addr;
1492 char fmt6[2] = { fmt[0], '6' };
1493 u8 off = 0;
1494
1495 fmt++;
1496 while (isalpha(*++fmt)) {
1497 switch (*fmt) {
1498 case 'p':
1499 have_p = true;
1500 break;
1501 case 'f':
1502 have_f = true;
1503 break;
1504 case 's':
1505 have_s = true;
1506 break;
1507 case 'c':
1508 have_c = true;
1509 break;
1510 }
1511 }
1512
1513 if (have_p || have_s || have_f) {
1514 *p = '[';
1515 off = 1;
1516 }
1517
1518 if (fmt6[0] == 'I' && have_c)
1519 p = ip6_compressed_string(ip6_addr + off, addr);
1520 else
1521 p = ip6_string(ip6_addr + off, addr, fmt6);
1522
1523 if (have_p || have_s || have_f)
1524 *p++ = ']';
1525
1526 if (have_p) {
1527 *p++ = ':';
1528 p = number(p, pend, ntohs(sa->sin6_port), spec);
1529 }
1530 if (have_f) {
1531 *p++ = '/';
1532 p = number(p, pend, ntohl(sa->sin6_flowinfo &
1533 IPV6_FLOWINFO_MASK), spec);
1534 }
1535 if (have_s) {
1536 *p++ = '%';
1537 p = number(p, pend, sa->sin6_scope_id, spec);
1538 }
1539 *p = '\0';
1540
1541 return string_nocheck(buf, end, ip6_addr, spec);
1542 }
1543
1544 static noinline_for_stack
ip4_addr_string_sa(char * buf,char * end,const struct sockaddr_in * sa,struct printf_spec spec,const char * fmt)1545 char *ip4_addr_string_sa(char *buf, char *end, const struct sockaddr_in *sa,
1546 struct printf_spec spec, const char *fmt)
1547 {
1548 bool have_p = false;
1549 char *p, ip4_addr[sizeof("255.255.255.255") + sizeof(":12345")];
1550 char *pend = ip4_addr + sizeof(ip4_addr);
1551 const u8 *addr = (const u8 *) &sa->sin_addr.s_addr;
1552 char fmt4[3] = { fmt[0], '4', 0 };
1553
1554 fmt++;
1555 while (isalpha(*++fmt)) {
1556 switch (*fmt) {
1557 case 'p':
1558 have_p = true;
1559 break;
1560 case 'h':
1561 case 'l':
1562 case 'n':
1563 case 'b':
1564 fmt4[2] = *fmt;
1565 break;
1566 }
1567 }
1568
1569 p = ip4_string(ip4_addr, addr, fmt4);
1570 if (have_p) {
1571 *p++ = ':';
1572 p = number(p, pend, ntohs(sa->sin_port), spec);
1573 }
1574 *p = '\0';
1575
1576 return string_nocheck(buf, end, ip4_addr, spec);
1577 }
1578
1579 static noinline_for_stack
ip_addr_string(char * buf,char * end,const void * ptr,struct printf_spec spec,const char * fmt)1580 char *ip_addr_string(char *buf, char *end, const void *ptr,
1581 struct printf_spec spec, const char *fmt)
1582 {
1583 char *err_fmt_msg;
1584
1585 if (check_pointer(&buf, end, ptr, spec))
1586 return buf;
1587
1588 switch (fmt[1]) {
1589 case '6':
1590 return ip6_addr_string(buf, end, ptr, spec, fmt);
1591 case '4':
1592 return ip4_addr_string(buf, end, ptr, spec, fmt);
1593 case 'S': {
1594 const union {
1595 struct sockaddr raw;
1596 struct sockaddr_in v4;
1597 struct sockaddr_in6 v6;
1598 } *sa = ptr;
1599
1600 switch (sa->raw.sa_family) {
1601 case AF_INET:
1602 return ip4_addr_string_sa(buf, end, &sa->v4, spec, fmt);
1603 case AF_INET6:
1604 return ip6_addr_string_sa(buf, end, &sa->v6, spec, fmt);
1605 default:
1606 return error_string(buf, end, "(einval)", spec);
1607 }}
1608 }
1609
1610 err_fmt_msg = fmt[0] == 'i' ? "(%pi?)" : "(%pI?)";
1611 return error_string(buf, end, err_fmt_msg, spec);
1612 }
1613
1614 static noinline_for_stack
escaped_string(char * buf,char * end,u8 * addr,struct printf_spec spec,const char * fmt)1615 char *escaped_string(char *buf, char *end, u8 *addr, struct printf_spec spec,
1616 const char *fmt)
1617 {
1618 bool found = true;
1619 int count = 1;
1620 unsigned int flags = 0;
1621 int len;
1622
1623 if (spec.field_width == 0)
1624 return buf; /* nothing to print */
1625
1626 if (check_pointer(&buf, end, addr, spec))
1627 return buf;
1628
1629 do {
1630 switch (fmt[count++]) {
1631 case 'a':
1632 flags |= ESCAPE_ANY;
1633 break;
1634 case 'c':
1635 flags |= ESCAPE_SPECIAL;
1636 break;
1637 case 'h':
1638 flags |= ESCAPE_HEX;
1639 break;
1640 case 'n':
1641 flags |= ESCAPE_NULL;
1642 break;
1643 case 'o':
1644 flags |= ESCAPE_OCTAL;
1645 break;
1646 case 'p':
1647 flags |= ESCAPE_NP;
1648 break;
1649 case 's':
1650 flags |= ESCAPE_SPACE;
1651 break;
1652 default:
1653 found = false;
1654 break;
1655 }
1656 } while (found);
1657
1658 if (!flags)
1659 flags = ESCAPE_ANY_NP;
1660
1661 len = spec.field_width < 0 ? 1 : spec.field_width;
1662
1663 /*
1664 * string_escape_mem() writes as many characters as it can to
1665 * the given buffer, and returns the total size of the output
1666 * had the buffer been big enough.
1667 */
1668 buf += string_escape_mem(addr, len, buf, buf < end ? end - buf : 0, flags, NULL);
1669
1670 return buf;
1671 }
1672
va_format(char * buf,char * end,struct va_format * va_fmt,struct printf_spec spec,const char * fmt)1673 static char *va_format(char *buf, char *end, struct va_format *va_fmt,
1674 struct printf_spec spec, const char *fmt)
1675 {
1676 va_list va;
1677
1678 if (check_pointer(&buf, end, va_fmt, spec))
1679 return buf;
1680
1681 va_copy(va, *va_fmt->va);
1682 buf += vsnprintf(buf, end > buf ? end - buf : 0, va_fmt->fmt, va);
1683 va_end(va);
1684
1685 return buf;
1686 }
1687
1688 static noinline_for_stack
uuid_string(char * buf,char * end,const u8 * addr,struct printf_spec spec,const char * fmt)1689 char *uuid_string(char *buf, char *end, const u8 *addr,
1690 struct printf_spec spec, const char *fmt)
1691 {
1692 char uuid[UUID_STRING_LEN + 1];
1693 char *p = uuid;
1694 int i;
1695 const u8 *index = uuid_index;
1696 bool uc = false;
1697
1698 if (check_pointer(&buf, end, addr, spec))
1699 return buf;
1700
1701 switch (*(++fmt)) {
1702 case 'L':
1703 uc = true;
1704 fallthrough;
1705 case 'l':
1706 index = guid_index;
1707 break;
1708 case 'B':
1709 uc = true;
1710 break;
1711 }
1712
1713 for (i = 0; i < 16; i++) {
1714 if (uc)
1715 p = hex_byte_pack_upper(p, addr[index[i]]);
1716 else
1717 p = hex_byte_pack(p, addr[index[i]]);
1718 switch (i) {
1719 case 3:
1720 case 5:
1721 case 7:
1722 case 9:
1723 *p++ = '-';
1724 break;
1725 }
1726 }
1727
1728 *p = 0;
1729
1730 return string_nocheck(buf, end, uuid, spec);
1731 }
1732
1733 static noinline_for_stack
netdev_bits(char * buf,char * end,const void * addr,struct printf_spec spec,const char * fmt)1734 char *netdev_bits(char *buf, char *end, const void *addr,
1735 struct printf_spec spec, const char *fmt)
1736 {
1737 unsigned long long num;
1738 int size;
1739
1740 if (check_pointer(&buf, end, addr, spec))
1741 return buf;
1742
1743 switch (fmt[1]) {
1744 case 'F':
1745 num = *(const netdev_features_t *)addr;
1746 size = sizeof(netdev_features_t);
1747 break;
1748 default:
1749 return error_string(buf, end, "(%pN?)", spec);
1750 }
1751
1752 return special_hex_number(buf, end, num, size);
1753 }
1754
1755 static noinline_for_stack
fourcc_string(char * buf,char * end,const u32 * fourcc,struct printf_spec spec,const char * fmt)1756 char *fourcc_string(char *buf, char *end, const u32 *fourcc,
1757 struct printf_spec spec, const char *fmt)
1758 {
1759 char output[sizeof("0123 little-endian (0x01234567)")];
1760 char *p = output;
1761 unsigned int i;
1762 u32 orig, val;
1763
1764 if (fmt[1] != 'c' || fmt[2] != 'c')
1765 return error_string(buf, end, "(%p4?)", spec);
1766
1767 if (check_pointer(&buf, end, fourcc, spec))
1768 return buf;
1769
1770 orig = get_unaligned(fourcc);
1771 val = orig & ~BIT(31);
1772
1773 for (i = 0; i < sizeof(u32); i++) {
1774 unsigned char c = val >> (i * 8);
1775
1776 /* Print non-control ASCII characters as-is, dot otherwise */
1777 *p++ = isascii(c) && isprint(c) ? c : '.';
1778 }
1779
1780 *p++ = ' ';
1781 strcpy(p, orig & BIT(31) ? "big-endian" : "little-endian");
1782 p += strlen(p);
1783
1784 *p++ = ' ';
1785 *p++ = '(';
1786 p = special_hex_number(p, output + sizeof(output) - 2, orig, sizeof(u32));
1787 *p++ = ')';
1788 *p = '\0';
1789
1790 return string(buf, end, output, spec);
1791 }
1792
1793 static noinline_for_stack
address_val(char * buf,char * end,const void * addr,struct printf_spec spec,const char * fmt)1794 char *address_val(char *buf, char *end, const void *addr,
1795 struct printf_spec spec, const char *fmt)
1796 {
1797 unsigned long long num;
1798 int size;
1799
1800 if (check_pointer(&buf, end, addr, spec))
1801 return buf;
1802
1803 switch (fmt[1]) {
1804 case 'd':
1805 num = *(const dma_addr_t *)addr;
1806 size = sizeof(dma_addr_t);
1807 break;
1808 case 'p':
1809 default:
1810 num = *(const phys_addr_t *)addr;
1811 size = sizeof(phys_addr_t);
1812 break;
1813 }
1814
1815 return special_hex_number(buf, end, num, size);
1816 }
1817
1818 static noinline_for_stack
date_str(char * buf,char * end,const struct rtc_time * tm,bool r)1819 char *date_str(char *buf, char *end, const struct rtc_time *tm, bool r)
1820 {
1821 int year = tm->tm_year + (r ? 0 : 1900);
1822 int mon = tm->tm_mon + (r ? 0 : 1);
1823
1824 buf = number(buf, end, year, default_dec04_spec);
1825 if (buf < end)
1826 *buf = '-';
1827 buf++;
1828
1829 buf = number(buf, end, mon, default_dec02_spec);
1830 if (buf < end)
1831 *buf = '-';
1832 buf++;
1833
1834 return number(buf, end, tm->tm_mday, default_dec02_spec);
1835 }
1836
1837 static noinline_for_stack
time_str(char * buf,char * end,const struct rtc_time * tm,bool r)1838 char *time_str(char *buf, char *end, const struct rtc_time *tm, bool r)
1839 {
1840 buf = number(buf, end, tm->tm_hour, default_dec02_spec);
1841 if (buf < end)
1842 *buf = ':';
1843 buf++;
1844
1845 buf = number(buf, end, tm->tm_min, default_dec02_spec);
1846 if (buf < end)
1847 *buf = ':';
1848 buf++;
1849
1850 return number(buf, end, tm->tm_sec, default_dec02_spec);
1851 }
1852
1853 static noinline_for_stack
rtc_str(char * buf,char * end,const struct rtc_time * tm,struct printf_spec spec,const char * fmt)1854 char *rtc_str(char *buf, char *end, const struct rtc_time *tm,
1855 struct printf_spec spec, const char *fmt)
1856 {
1857 bool have_t = true, have_d = true;
1858 bool raw = false, iso8601_separator = true;
1859 bool found = true;
1860 int count = 2;
1861
1862 if (check_pointer(&buf, end, tm, spec))
1863 return buf;
1864
1865 switch (fmt[count]) {
1866 case 'd':
1867 have_t = false;
1868 count++;
1869 break;
1870 case 't':
1871 have_d = false;
1872 count++;
1873 break;
1874 }
1875
1876 do {
1877 switch (fmt[count++]) {
1878 case 'r':
1879 raw = true;
1880 break;
1881 case 's':
1882 iso8601_separator = false;
1883 break;
1884 default:
1885 found = false;
1886 break;
1887 }
1888 } while (found);
1889
1890 if (have_d)
1891 buf = date_str(buf, end, tm, raw);
1892 if (have_d && have_t) {
1893 if (buf < end)
1894 *buf = iso8601_separator ? 'T' : ' ';
1895 buf++;
1896 }
1897 if (have_t)
1898 buf = time_str(buf, end, tm, raw);
1899
1900 return buf;
1901 }
1902
1903 static noinline_for_stack
time64_str(char * buf,char * end,const time64_t time,struct printf_spec spec,const char * fmt)1904 char *time64_str(char *buf, char *end, const time64_t time,
1905 struct printf_spec spec, const char *fmt)
1906 {
1907 struct rtc_time rtc_time;
1908 struct tm tm;
1909
1910 time64_to_tm(time, 0, &tm);
1911
1912 rtc_time.tm_sec = tm.tm_sec;
1913 rtc_time.tm_min = tm.tm_min;
1914 rtc_time.tm_hour = tm.tm_hour;
1915 rtc_time.tm_mday = tm.tm_mday;
1916 rtc_time.tm_mon = tm.tm_mon;
1917 rtc_time.tm_year = tm.tm_year;
1918 rtc_time.tm_wday = tm.tm_wday;
1919 rtc_time.tm_yday = tm.tm_yday;
1920
1921 rtc_time.tm_isdst = 0;
1922
1923 return rtc_str(buf, end, &rtc_time, spec, fmt);
1924 }
1925
1926 static noinline_for_stack
time_and_date(char * buf,char * end,void * ptr,struct printf_spec spec,const char * fmt)1927 char *time_and_date(char *buf, char *end, void *ptr, struct printf_spec spec,
1928 const char *fmt)
1929 {
1930 switch (fmt[1]) {
1931 case 'R':
1932 return rtc_str(buf, end, (const struct rtc_time *)ptr, spec, fmt);
1933 case 'T':
1934 return time64_str(buf, end, *(const time64_t *)ptr, spec, fmt);
1935 default:
1936 return error_string(buf, end, "(%pt?)", spec);
1937 }
1938 }
1939
1940 static noinline_for_stack
clock(char * buf,char * end,struct clk * clk,struct printf_spec spec,const char * fmt)1941 char *clock(char *buf, char *end, struct clk *clk, struct printf_spec spec,
1942 const char *fmt)
1943 {
1944 if (!IS_ENABLED(CONFIG_HAVE_CLK))
1945 return error_string(buf, end, "(%pC?)", spec);
1946
1947 if (check_pointer(&buf, end, clk, spec))
1948 return buf;
1949
1950 switch (fmt[1]) {
1951 case 'n':
1952 default:
1953 #ifdef CONFIG_COMMON_CLK
1954 return string(buf, end, __clk_get_name(clk), spec);
1955 #else
1956 return ptr_to_id(buf, end, clk, spec);
1957 #endif
1958 }
1959 }
1960
1961 static
format_flags(char * buf,char * end,unsigned long flags,const struct trace_print_flags * names)1962 char *format_flags(char *buf, char *end, unsigned long flags,
1963 const struct trace_print_flags *names)
1964 {
1965 unsigned long mask;
1966
1967 for ( ; flags && names->name; names++) {
1968 mask = names->mask;
1969 if ((flags & mask) != mask)
1970 continue;
1971
1972 buf = string(buf, end, names->name, default_str_spec);
1973
1974 flags &= ~mask;
1975 if (flags) {
1976 if (buf < end)
1977 *buf = '|';
1978 buf++;
1979 }
1980 }
1981
1982 if (flags)
1983 buf = number(buf, end, flags, default_flag_spec);
1984
1985 return buf;
1986 }
1987
1988 struct page_flags_fields {
1989 int width;
1990 int shift;
1991 int mask;
1992 const struct printf_spec *spec;
1993 const char *name;
1994 };
1995
1996 static const struct page_flags_fields pff[] = {
1997 {SECTIONS_WIDTH, SECTIONS_PGSHIFT, SECTIONS_MASK,
1998 &default_dec_spec, "section"},
1999 {NODES_WIDTH, NODES_PGSHIFT, NODES_MASK,
2000 &default_dec_spec, "node"},
2001 {ZONES_WIDTH, ZONES_PGSHIFT, ZONES_MASK,
2002 &default_dec_spec, "zone"},
2003 {LAST_CPUPID_WIDTH, LAST_CPUPID_PGSHIFT, LAST_CPUPID_MASK,
2004 &default_flag_spec, "lastcpupid"},
2005 {KASAN_TAG_WIDTH, KASAN_TAG_PGSHIFT, KASAN_TAG_MASK,
2006 &default_flag_spec, "kasantag"},
2007 };
2008
2009 static
format_page_flags(char * buf,char * end,unsigned long flags)2010 char *format_page_flags(char *buf, char *end, unsigned long flags)
2011 {
2012 unsigned long main_flags = flags & PAGEFLAGS_MASK;
2013 bool append = false;
2014 int i;
2015
2016 buf = number(buf, end, flags, default_flag_spec);
2017 if (buf < end)
2018 *buf = '(';
2019 buf++;
2020
2021 /* Page flags from the main area. */
2022 if (main_flags) {
2023 buf = format_flags(buf, end, main_flags, pageflag_names);
2024 append = true;
2025 }
2026
2027 /* Page flags from the fields area */
2028 for (i = 0; i < ARRAY_SIZE(pff); i++) {
2029 /* Skip undefined fields. */
2030 if (!pff[i].width)
2031 continue;
2032
2033 /* Format: Flag Name + '=' (equals sign) + Number + '|' (separator) */
2034 if (append) {
2035 if (buf < end)
2036 *buf = '|';
2037 buf++;
2038 }
2039
2040 buf = string(buf, end, pff[i].name, default_str_spec);
2041 if (buf < end)
2042 *buf = '=';
2043 buf++;
2044 buf = number(buf, end, (flags >> pff[i].shift) & pff[i].mask,
2045 *pff[i].spec);
2046
2047 append = true;
2048 }
2049 if (buf < end)
2050 *buf = ')';
2051 buf++;
2052
2053 return buf;
2054 }
2055
2056 static
format_page_type(char * buf,char * end,unsigned int page_type)2057 char *format_page_type(char *buf, char *end, unsigned int page_type)
2058 {
2059 buf = number(buf, end, page_type, default_flag_spec);
2060
2061 if (buf < end)
2062 *buf = '(';
2063 buf++;
2064
2065 if (page_type_has_type(page_type))
2066 buf = format_flags(buf, end, ~page_type, pagetype_names);
2067
2068 if (buf < end)
2069 *buf = ')';
2070 buf++;
2071
2072 return buf;
2073 }
2074
2075 static noinline_for_stack
flags_string(char * buf,char * end,void * flags_ptr,struct printf_spec spec,const char * fmt)2076 char *flags_string(char *buf, char *end, void *flags_ptr,
2077 struct printf_spec spec, const char *fmt)
2078 {
2079 unsigned long flags;
2080 const struct trace_print_flags *names;
2081
2082 if (check_pointer(&buf, end, flags_ptr, spec))
2083 return buf;
2084
2085 switch (fmt[1]) {
2086 case 'p':
2087 return format_page_flags(buf, end, *(unsigned long *)flags_ptr);
2088 case 't':
2089 return format_page_type(buf, end, *(unsigned int *)flags_ptr);
2090 case 'v':
2091 flags = *(unsigned long *)flags_ptr;
2092 names = vmaflag_names;
2093 break;
2094 case 'g':
2095 flags = (__force unsigned long)(*(gfp_t *)flags_ptr);
2096 names = gfpflag_names;
2097 break;
2098 default:
2099 return error_string(buf, end, "(%pG?)", spec);
2100 }
2101
2102 return format_flags(buf, end, flags, names);
2103 }
2104
2105 static noinline_for_stack
fwnode_full_name_string(struct fwnode_handle * fwnode,char * buf,char * end)2106 char *fwnode_full_name_string(struct fwnode_handle *fwnode, char *buf,
2107 char *end)
2108 {
2109 int depth;
2110
2111 /* Loop starting from the root node to the current node. */
2112 for (depth = fwnode_count_parents(fwnode); depth >= 0; depth--) {
2113 /*
2114 * Only get a reference for other nodes (i.e. parent nodes).
2115 * fwnode refcount may be 0 here.
2116 */
2117 struct fwnode_handle *__fwnode = depth ?
2118 fwnode_get_nth_parent(fwnode, depth) : fwnode;
2119
2120 buf = string(buf, end, fwnode_get_name_prefix(__fwnode),
2121 default_str_spec);
2122 buf = string(buf, end, fwnode_get_name(__fwnode),
2123 default_str_spec);
2124
2125 if (depth)
2126 fwnode_handle_put(__fwnode);
2127 }
2128
2129 return buf;
2130 }
2131
2132 static noinline_for_stack
device_node_string(char * buf,char * end,struct device_node * dn,struct printf_spec spec,const char * fmt)2133 char *device_node_string(char *buf, char *end, struct device_node *dn,
2134 struct printf_spec spec, const char *fmt)
2135 {
2136 char tbuf[sizeof("xxxx") + 1];
2137 const char *p;
2138 int ret;
2139 char *buf_start = buf;
2140 struct property *prop;
2141 bool has_mult, pass;
2142
2143 struct printf_spec str_spec = spec;
2144 str_spec.field_width = -1;
2145
2146 if (fmt[0] != 'F')
2147 return error_string(buf, end, "(%pO?)", spec);
2148
2149 if (!IS_ENABLED(CONFIG_OF))
2150 return error_string(buf, end, "(%pOF?)", spec);
2151
2152 if (check_pointer(&buf, end, dn, spec))
2153 return buf;
2154
2155 /* simple case without anything any more format specifiers */
2156 fmt++;
2157 if (fmt[0] == '\0' || strcspn(fmt,"fnpPFcC") > 0)
2158 fmt = "f";
2159
2160 for (pass = false; strspn(fmt,"fnpPFcC"); fmt++, pass = true) {
2161 int precision;
2162 if (pass) {
2163 if (buf < end)
2164 *buf = ':';
2165 buf++;
2166 }
2167
2168 switch (*fmt) {
2169 case 'f': /* full_name */
2170 buf = fwnode_full_name_string(of_fwnode_handle(dn), buf,
2171 end);
2172 break;
2173 case 'n': /* name */
2174 p = fwnode_get_name(of_fwnode_handle(dn));
2175 precision = str_spec.precision;
2176 str_spec.precision = strchrnul(p, '@') - p;
2177 buf = string(buf, end, p, str_spec);
2178 str_spec.precision = precision;
2179 break;
2180 case 'p': /* phandle */
2181 buf = number(buf, end, (unsigned int)dn->phandle, default_dec_spec);
2182 break;
2183 case 'P': /* path-spec */
2184 p = fwnode_get_name(of_fwnode_handle(dn));
2185 if (!p[1])
2186 p = "/";
2187 buf = string(buf, end, p, str_spec);
2188 break;
2189 case 'F': /* flags */
2190 tbuf[0] = of_node_check_flag(dn, OF_DYNAMIC) ? 'D' : '-';
2191 tbuf[1] = of_node_check_flag(dn, OF_DETACHED) ? 'd' : '-';
2192 tbuf[2] = of_node_check_flag(dn, OF_POPULATED) ? 'P' : '-';
2193 tbuf[3] = of_node_check_flag(dn, OF_POPULATED_BUS) ? 'B' : '-';
2194 tbuf[4] = 0;
2195 buf = string_nocheck(buf, end, tbuf, str_spec);
2196 break;
2197 case 'c': /* major compatible string */
2198 ret = of_property_read_string(dn, "compatible", &p);
2199 if (!ret)
2200 buf = string(buf, end, p, str_spec);
2201 break;
2202 case 'C': /* full compatible string */
2203 has_mult = false;
2204 of_property_for_each_string(dn, "compatible", prop, p) {
2205 if (has_mult)
2206 buf = string_nocheck(buf, end, ",", str_spec);
2207 buf = string_nocheck(buf, end, "\"", str_spec);
2208 buf = string(buf, end, p, str_spec);
2209 buf = string_nocheck(buf, end, "\"", str_spec);
2210
2211 has_mult = true;
2212 }
2213 break;
2214 default:
2215 break;
2216 }
2217 }
2218
2219 return widen_string(buf, buf - buf_start, end, spec);
2220 }
2221
2222 static noinline_for_stack
fwnode_string(char * buf,char * end,struct fwnode_handle * fwnode,struct printf_spec spec,const char * fmt)2223 char *fwnode_string(char *buf, char *end, struct fwnode_handle *fwnode,
2224 struct printf_spec spec, const char *fmt)
2225 {
2226 struct printf_spec str_spec = spec;
2227 char *buf_start = buf;
2228
2229 str_spec.field_width = -1;
2230
2231 if (*fmt != 'w')
2232 return error_string(buf, end, "(%pf?)", spec);
2233
2234 if (check_pointer(&buf, end, fwnode, spec))
2235 return buf;
2236
2237 fmt++;
2238
2239 switch (*fmt) {
2240 case 'P': /* name */
2241 buf = string(buf, end, fwnode_get_name(fwnode), str_spec);
2242 break;
2243 case 'f': /* full_name */
2244 default:
2245 buf = fwnode_full_name_string(fwnode, buf, end);
2246 break;
2247 }
2248
2249 return widen_string(buf, buf - buf_start, end, spec);
2250 }
2251
no_hash_pointers_enable(char * str)2252 int __init no_hash_pointers_enable(char *str)
2253 {
2254 if (no_hash_pointers)
2255 return 0;
2256
2257 no_hash_pointers = true;
2258
2259 pr_warn("**********************************************************\n");
2260 pr_warn("** NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE **\n");
2261 pr_warn("** **\n");
2262 pr_warn("** This system shows unhashed kernel memory addresses **\n");
2263 pr_warn("** via the console, logs, and other interfaces. This **\n");
2264 pr_warn("** might reduce the security of your system. **\n");
2265 pr_warn("** **\n");
2266 pr_warn("** If you see this message and you are not debugging **\n");
2267 pr_warn("** the kernel, report this immediately to your system **\n");
2268 pr_warn("** administrator! **\n");
2269 pr_warn("** **\n");
2270 pr_warn("** NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE **\n");
2271 pr_warn("**********************************************************\n");
2272
2273 return 0;
2274 }
2275 early_param("no_hash_pointers", no_hash_pointers_enable);
2276
2277 /* Used for Rust formatting ('%pA'). */
2278 char *rust_fmt_argument(char *buf, char *end, void *ptr);
2279
2280 /*
2281 * Show a '%p' thing. A kernel extension is that the '%p' is followed
2282 * by an extra set of alphanumeric characters that are extended format
2283 * specifiers.
2284 *
2285 * Please update scripts/checkpatch.pl when adding/removing conversion
2286 * characters. (Search for "check for vsprintf extension").
2287 *
2288 * Right now we handle:
2289 *
2290 * - 'S' For symbolic direct pointers (or function descriptors) with offset
2291 * - 's' For symbolic direct pointers (or function descriptors) without offset
2292 * - '[Ss]R' as above with __builtin_extract_return_addr() translation
2293 * - 'S[R]b' as above with module build ID (for use in backtraces)
2294 * - '[Ff]' %pf and %pF were obsoleted and later removed in favor of
2295 * %ps and %pS. Be careful when re-using these specifiers.
2296 * - 'B' For backtraced symbolic direct pointers with offset
2297 * - 'Bb' as above with module build ID (for use in backtraces)
2298 * - 'R' For decoded struct resource, e.g., [mem 0x0-0x1f 64bit pref]
2299 * - 'r' For raw struct resource, e.g., [mem 0x0-0x1f flags 0x201]
2300 * - 'b[l]' For a bitmap, the number of bits is determined by the field
2301 * width which must be explicitly specified either as part of the
2302 * format string '%32b[l]' or through '%*b[l]', [l] selects
2303 * range-list format instead of hex format
2304 * - 'M' For a 6-byte MAC address, it prints the address in the
2305 * usual colon-separated hex notation
2306 * - 'm' For a 6-byte MAC address, it prints the hex address without colons
2307 * - 'MF' For a 6-byte MAC FDDI address, it prints the address
2308 * with a dash-separated hex notation
2309 * - '[mM]R' For a 6-byte MAC address, Reverse order (Bluetooth)
2310 * - 'I' [46] for IPv4/IPv6 addresses printed in the usual way
2311 * IPv4 uses dot-separated decimal without leading 0's (1.2.3.4)
2312 * IPv6 uses colon separated network-order 16 bit hex with leading 0's
2313 * [S][pfs]
2314 * Generic IPv4/IPv6 address (struct sockaddr *) that falls back to
2315 * [4] or [6] and is able to print port [p], flowinfo [f], scope [s]
2316 * - 'i' [46] for 'raw' IPv4/IPv6 addresses
2317 * IPv6 omits the colons (01020304...0f)
2318 * IPv4 uses dot-separated decimal with leading 0's (010.123.045.006)
2319 * [S][pfs]
2320 * Generic IPv4/IPv6 address (struct sockaddr *) that falls back to
2321 * [4] or [6] and is able to print port [p], flowinfo [f], scope [s]
2322 * - '[Ii][4S][hnbl]' IPv4 addresses in host, network, big or little endian order
2323 * - 'I[6S]c' for IPv6 addresses printed as specified by
2324 * https://tools.ietf.org/html/rfc5952
2325 * - 'E[achnops]' For an escaped buffer, where rules are defined by combination
2326 * of the following flags (see string_escape_mem() for the
2327 * details):
2328 * a - ESCAPE_ANY
2329 * c - ESCAPE_SPECIAL
2330 * h - ESCAPE_HEX
2331 * n - ESCAPE_NULL
2332 * o - ESCAPE_OCTAL
2333 * p - ESCAPE_NP
2334 * s - ESCAPE_SPACE
2335 * By default ESCAPE_ANY_NP is used.
2336 * - 'U' For a 16 byte UUID/GUID, it prints the UUID/GUID in the form
2337 * "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx"
2338 * Options for %pU are:
2339 * b big endian lower case hex (default)
2340 * B big endian UPPER case hex
2341 * l little endian lower case hex
2342 * L little endian UPPER case hex
2343 * big endian output byte order is:
2344 * [0][1][2][3]-[4][5]-[6][7]-[8][9]-[10][11][12][13][14][15]
2345 * little endian output byte order is:
2346 * [3][2][1][0]-[5][4]-[7][6]-[8][9]-[10][11][12][13][14][15]
2347 * - 'V' For a struct va_format which contains a format string * and va_list *,
2348 * call vsnprintf(->format, *->va_list).
2349 * Implements a "recursive vsnprintf".
2350 * Do not use this feature without some mechanism to verify the
2351 * correctness of the format string and va_list arguments.
2352 * - 'K' For a kernel pointer that should be hidden from unprivileged users.
2353 * Use only for procfs, sysfs and similar files, not printk(); please
2354 * read the documentation (path below) first.
2355 * - 'NF' For a netdev_features_t
2356 * - '4cc' V4L2 or DRM FourCC code, with endianness and raw numerical value.
2357 * - 'h[CDN]' For a variable-length buffer, it prints it as a hex string with
2358 * a certain separator (' ' by default):
2359 * C colon
2360 * D dash
2361 * N no separator
2362 * The maximum supported length is 64 bytes of the input. Consider
2363 * to use print_hex_dump() for the larger input.
2364 * - 'a[pd]' For address types [p] phys_addr_t, [d] dma_addr_t and derivatives
2365 * (default assumed to be phys_addr_t, passed by reference)
2366 * - 'd[234]' For a dentry name (optionally 2-4 last components)
2367 * - 'D[234]' Same as 'd' but for a struct file
2368 * - 'g' For block_device name (gendisk + partition number)
2369 * - 't[RT][dt][r][s]' For time and date as represented by:
2370 * R struct rtc_time
2371 * T time64_t
2372 * - 'C' For a clock, it prints the name (Common Clock Framework) or address
2373 * (legacy clock framework) of the clock
2374 * - 'Cn' For a clock, it prints the name (Common Clock Framework) or address
2375 * (legacy clock framework) of the clock
2376 * - 'G' For flags to be printed as a collection of symbolic strings that would
2377 * construct the specific value. Supported flags given by option:
2378 * p page flags (see struct page) given as pointer to unsigned long
2379 * g gfp flags (GFP_* and __GFP_*) given as pointer to gfp_t
2380 * v vma flags (VM_*) given as pointer to unsigned long
2381 * - 'OF[fnpPcCF]' For a device tree object
2382 * Without any optional arguments prints the full_name
2383 * f device node full_name
2384 * n device node name
2385 * p device node phandle
2386 * P device node path spec (name + @unit)
2387 * F device node flags
2388 * c major compatible string
2389 * C full compatible string
2390 * - 'fw[fP]' For a firmware node (struct fwnode_handle) pointer
2391 * Without an option prints the full name of the node
2392 * f full name
2393 * P node name, including a possible unit address
2394 * - 'x' For printing the address unmodified. Equivalent to "%lx".
2395 * Please read the documentation (path below) before using!
2396 * - '[ku]s' For a BPF/tracing related format specifier, e.g. used out of
2397 * bpf_trace_printk() where [ku] prefix specifies either kernel (k)
2398 * or user (u) memory to probe, and:
2399 * s a string, equivalent to "%s" on direct vsnprintf() use
2400 *
2401 * ** When making changes please also update:
2402 * Documentation/core-api/printk-formats.rst
2403 *
2404 * Note: The default behaviour (unadorned %p) is to hash the address,
2405 * rendering it useful as a unique identifier.
2406 *
2407 * There is also a '%pA' format specifier, but it is only intended to be used
2408 * from Rust code to format core::fmt::Arguments. Do *not* use it from C.
2409 * See rust/kernel/print.rs for details.
2410 */
2411 static noinline_for_stack
pointer(const char * fmt,char * buf,char * end,void * ptr,struct printf_spec spec)2412 char *pointer(const char *fmt, char *buf, char *end, void *ptr,
2413 struct printf_spec spec)
2414 {
2415 switch (*fmt) {
2416 case 'S':
2417 case 's':
2418 ptr = dereference_symbol_descriptor(ptr);
2419 fallthrough;
2420 case 'B':
2421 return symbol_string(buf, end, ptr, spec, fmt);
2422 case 'R':
2423 case 'r':
2424 return resource_string(buf, end, ptr, spec, fmt);
2425 case 'h':
2426 return hex_string(buf, end, ptr, spec, fmt);
2427 case 'b':
2428 switch (fmt[1]) {
2429 case 'l':
2430 return bitmap_list_string(buf, end, ptr, spec, fmt);
2431 default:
2432 return bitmap_string(buf, end, ptr, spec, fmt);
2433 }
2434 case 'M': /* Colon separated: 00:01:02:03:04:05 */
2435 case 'm': /* Contiguous: 000102030405 */
2436 /* [mM]F (FDDI) */
2437 /* [mM]R (Reverse order; Bluetooth) */
2438 return mac_address_string(buf, end, ptr, spec, fmt);
2439 case 'I': /* Formatted IP supported
2440 * 4: 1.2.3.4
2441 * 6: 0001:0203:...:0708
2442 * 6c: 1::708 or 1::1.2.3.4
2443 */
2444 case 'i': /* Contiguous:
2445 * 4: 001.002.003.004
2446 * 6: 000102...0f
2447 */
2448 return ip_addr_string(buf, end, ptr, spec, fmt);
2449 case 'E':
2450 return escaped_string(buf, end, ptr, spec, fmt);
2451 case 'U':
2452 return uuid_string(buf, end, ptr, spec, fmt);
2453 case 'V':
2454 return va_format(buf, end, ptr, spec, fmt);
2455 case 'K':
2456 return restricted_pointer(buf, end, ptr, spec);
2457 case 'N':
2458 return netdev_bits(buf, end, ptr, spec, fmt);
2459 case '4':
2460 return fourcc_string(buf, end, ptr, spec, fmt);
2461 case 'a':
2462 return address_val(buf, end, ptr, spec, fmt);
2463 case 'd':
2464 return dentry_name(buf, end, ptr, spec, fmt);
2465 case 't':
2466 return time_and_date(buf, end, ptr, spec, fmt);
2467 case 'C':
2468 return clock(buf, end, ptr, spec, fmt);
2469 case 'D':
2470 return file_dentry_name(buf, end, ptr, spec, fmt);
2471 #ifdef CONFIG_BLOCK
2472 case 'g':
2473 return bdev_name(buf, end, ptr, spec, fmt);
2474 #endif
2475
2476 case 'G':
2477 return flags_string(buf, end, ptr, spec, fmt);
2478 case 'O':
2479 return device_node_string(buf, end, ptr, spec, fmt + 1);
2480 case 'f':
2481 return fwnode_string(buf, end, ptr, spec, fmt + 1);
2482 case 'A':
2483 if (!IS_ENABLED(CONFIG_RUST)) {
2484 WARN_ONCE(1, "Please remove %%pA from non-Rust code\n");
2485 return error_string(buf, end, "(%pA?)", spec);
2486 }
2487 return rust_fmt_argument(buf, end, ptr);
2488 case 'x':
2489 return pointer_string(buf, end, ptr, spec);
2490 case 'e':
2491 /* %pe with a non-ERR_PTR gets treated as plain %p */
2492 if (!IS_ERR(ptr))
2493 return default_pointer(buf, end, ptr, spec);
2494 return err_ptr(buf, end, ptr, spec);
2495 case 'u':
2496 case 'k':
2497 switch (fmt[1]) {
2498 case 's':
2499 return string(buf, end, ptr, spec);
2500 default:
2501 return error_string(buf, end, "(einval)", spec);
2502 }
2503 default:
2504 return default_pointer(buf, end, ptr, spec);
2505 }
2506 }
2507
2508 /*
2509 * Helper function to decode printf style format.
2510 * Each call decode a token from the format and return the
2511 * number of characters read (or likely the delta where it wants
2512 * to go on the next call).
2513 * The decoded token is returned through the parameters
2514 *
2515 * 'h', 'l', or 'L' for integer fields
2516 * 'z' support added 23/7/1999 S.H.
2517 * 'z' changed to 'Z' --davidm 1/25/99
2518 * 'Z' changed to 'z' --adobriyan 2017-01-25
2519 * 't' added for ptrdiff_t
2520 *
2521 * @fmt: the format string
2522 * @type of the token returned
2523 * @flags: various flags such as +, -, # tokens..
2524 * @field_width: overwritten width
2525 * @base: base of the number (octal, hex, ...)
2526 * @precision: precision of a number
2527 * @qualifier: qualifier of a number (long, size_t, ...)
2528 */
2529 static noinline_for_stack
format_decode(const char * fmt,struct printf_spec * spec)2530 int format_decode(const char *fmt, struct printf_spec *spec)
2531 {
2532 const char *start = fmt;
2533 char qualifier;
2534
2535 /* we finished early by reading the field width */
2536 if (spec->type == FORMAT_TYPE_WIDTH) {
2537 if (spec->field_width < 0) {
2538 spec->field_width = -spec->field_width;
2539 spec->flags |= LEFT;
2540 }
2541 spec->type = FORMAT_TYPE_NONE;
2542 goto precision;
2543 }
2544
2545 /* we finished early by reading the precision */
2546 if (spec->type == FORMAT_TYPE_PRECISION) {
2547 if (spec->precision < 0)
2548 spec->precision = 0;
2549
2550 spec->type = FORMAT_TYPE_NONE;
2551 goto qualifier;
2552 }
2553
2554 /* By default */
2555 spec->type = FORMAT_TYPE_NONE;
2556
2557 for (; *fmt ; ++fmt) {
2558 if (*fmt == '%')
2559 break;
2560 }
2561
2562 /* Return the current non-format string */
2563 if (fmt != start || !*fmt)
2564 return fmt - start;
2565
2566 /* Process flags */
2567 spec->flags = 0;
2568
2569 while (1) { /* this also skips first '%' */
2570 bool found = true;
2571
2572 ++fmt;
2573
2574 switch (*fmt) {
2575 case '-': spec->flags |= LEFT; break;
2576 case '+': spec->flags |= PLUS; break;
2577 case ' ': spec->flags |= SPACE; break;
2578 case '#': spec->flags |= SPECIAL; break;
2579 case '0': spec->flags |= ZEROPAD; break;
2580 default: found = false;
2581 }
2582
2583 if (!found)
2584 break;
2585 }
2586
2587 /* get field width */
2588 spec->field_width = -1;
2589
2590 if (isdigit(*fmt))
2591 spec->field_width = skip_atoi(&fmt);
2592 else if (*fmt == '*') {
2593 /* it's the next argument */
2594 spec->type = FORMAT_TYPE_WIDTH;
2595 return ++fmt - start;
2596 }
2597
2598 precision:
2599 /* get the precision */
2600 spec->precision = -1;
2601 if (*fmt == '.') {
2602 ++fmt;
2603 if (isdigit(*fmt)) {
2604 spec->precision = skip_atoi(&fmt);
2605 if (spec->precision < 0)
2606 spec->precision = 0;
2607 } else if (*fmt == '*') {
2608 /* it's the next argument */
2609 spec->type = FORMAT_TYPE_PRECISION;
2610 return ++fmt - start;
2611 }
2612 }
2613
2614 qualifier:
2615 /* get the conversion qualifier */
2616 qualifier = 0;
2617 if (*fmt == 'h' || _tolower(*fmt) == 'l' ||
2618 *fmt == 'z' || *fmt == 't') {
2619 qualifier = *fmt++;
2620 if (unlikely(qualifier == *fmt)) {
2621 if (qualifier == 'l') {
2622 qualifier = 'L';
2623 ++fmt;
2624 } else if (qualifier == 'h') {
2625 qualifier = 'H';
2626 ++fmt;
2627 }
2628 }
2629 }
2630
2631 /* default base */
2632 spec->base = 10;
2633 switch (*fmt) {
2634 case 'c':
2635 spec->type = FORMAT_TYPE_CHAR;
2636 return ++fmt - start;
2637
2638 case 's':
2639 spec->type = FORMAT_TYPE_STR;
2640 return ++fmt - start;
2641
2642 case 'p':
2643 spec->type = FORMAT_TYPE_PTR;
2644 return ++fmt - start;
2645
2646 case '%':
2647 spec->type = FORMAT_TYPE_PERCENT_CHAR;
2648 return ++fmt - start;
2649
2650 /* integer number formats - set up the flags and "break" */
2651 case 'o':
2652 spec->base = 8;
2653 break;
2654
2655 case 'x':
2656 spec->flags |= SMALL;
2657 fallthrough;
2658
2659 case 'X':
2660 spec->base = 16;
2661 break;
2662
2663 case 'd':
2664 case 'i':
2665 spec->flags |= SIGN;
2666 break;
2667 case 'u':
2668 break;
2669
2670 case 'n':
2671 /*
2672 * Since %n poses a greater security risk than
2673 * utility, treat it as any other invalid or
2674 * unsupported format specifier.
2675 */
2676 fallthrough;
2677
2678 default:
2679 WARN_ONCE(1, "Please remove unsupported %%%c in format string\n", *fmt);
2680 spec->type = FORMAT_TYPE_INVALID;
2681 return fmt - start;
2682 }
2683
2684 if (qualifier == 'L')
2685 spec->type = FORMAT_TYPE_LONG_LONG;
2686 else if (qualifier == 'l') {
2687 BUILD_BUG_ON(FORMAT_TYPE_ULONG + SIGN != FORMAT_TYPE_LONG);
2688 spec->type = FORMAT_TYPE_ULONG + (spec->flags & SIGN);
2689 } else if (qualifier == 'z') {
2690 spec->type = FORMAT_TYPE_SIZE_T;
2691 } else if (qualifier == 't') {
2692 spec->type = FORMAT_TYPE_PTRDIFF;
2693 } else if (qualifier == 'H') {
2694 BUILD_BUG_ON(FORMAT_TYPE_UBYTE + SIGN != FORMAT_TYPE_BYTE);
2695 spec->type = FORMAT_TYPE_UBYTE + (spec->flags & SIGN);
2696 } else if (qualifier == 'h') {
2697 BUILD_BUG_ON(FORMAT_TYPE_USHORT + SIGN != FORMAT_TYPE_SHORT);
2698 spec->type = FORMAT_TYPE_USHORT + (spec->flags & SIGN);
2699 } else {
2700 BUILD_BUG_ON(FORMAT_TYPE_UINT + SIGN != FORMAT_TYPE_INT);
2701 spec->type = FORMAT_TYPE_UINT + (spec->flags & SIGN);
2702 }
2703
2704 return ++fmt - start;
2705 }
2706
2707 static void
set_field_width(struct printf_spec * spec,int width)2708 set_field_width(struct printf_spec *spec, int width)
2709 {
2710 spec->field_width = width;
2711 if (WARN_ONCE(spec->field_width != width, "field width %d too large", width)) {
2712 spec->field_width = clamp(width, -FIELD_WIDTH_MAX, FIELD_WIDTH_MAX);
2713 }
2714 }
2715
2716 static void
set_precision(struct printf_spec * spec,int prec)2717 set_precision(struct printf_spec *spec, int prec)
2718 {
2719 spec->precision = prec;
2720 if (WARN_ONCE(spec->precision != prec, "precision %d too large", prec)) {
2721 spec->precision = clamp(prec, 0, PRECISION_MAX);
2722 }
2723 }
2724
2725 /**
2726 * vsnprintf - Format a string and place it in a buffer
2727 * @buf: The buffer to place the result into
2728 * @size: The size of the buffer, including the trailing null space
2729 * @fmt: The format string to use
2730 * @args: Arguments for the format string
2731 *
2732 * This function generally follows C99 vsnprintf, but has some
2733 * extensions and a few limitations:
2734 *
2735 * - ``%n`` is unsupported
2736 * - ``%p*`` is handled by pointer()
2737 *
2738 * See pointer() or Documentation/core-api/printk-formats.rst for more
2739 * extensive description.
2740 *
2741 * **Please update the documentation in both places when making changes**
2742 *
2743 * The return value is the number of characters which would
2744 * be generated for the given input, excluding the trailing
2745 * '\0', as per ISO C99. If you want to have the exact
2746 * number of characters written into @buf as return value
2747 * (not including the trailing '\0'), use vscnprintf(). If the
2748 * return is greater than or equal to @size, the resulting
2749 * string is truncated.
2750 *
2751 * If you're not already dealing with a va_list consider using snprintf().
2752 */
vsnprintf(char * buf,size_t size,const char * fmt,va_list args)2753 int vsnprintf(char *buf, size_t size, const char *fmt, va_list args)
2754 {
2755 unsigned long long num;
2756 char *str, *end;
2757 struct printf_spec spec = {0};
2758
2759 /* Reject out-of-range values early. Large positive sizes are
2760 used for unknown buffer sizes. */
2761 if (WARN_ON_ONCE(size > INT_MAX))
2762 return 0;
2763
2764 str = buf;
2765 end = buf + size;
2766
2767 /* Make sure end is always >= buf */
2768 if (end < buf) {
2769 end = ((void *)-1);
2770 size = end - buf;
2771 }
2772
2773 while (*fmt) {
2774 const char *old_fmt = fmt;
2775 int read = format_decode(fmt, &spec);
2776
2777 fmt += read;
2778
2779 switch (spec.type) {
2780 case FORMAT_TYPE_NONE: {
2781 int copy = read;
2782 if (str < end) {
2783 if (copy > end - str)
2784 copy = end - str;
2785 memcpy(str, old_fmt, copy);
2786 }
2787 str += read;
2788 break;
2789 }
2790
2791 case FORMAT_TYPE_WIDTH:
2792 set_field_width(&spec, va_arg(args, int));
2793 break;
2794
2795 case FORMAT_TYPE_PRECISION:
2796 set_precision(&spec, va_arg(args, int));
2797 break;
2798
2799 case FORMAT_TYPE_CHAR: {
2800 char c;
2801
2802 if (!(spec.flags & LEFT)) {
2803 while (--spec.field_width > 0) {
2804 if (str < end)
2805 *str = ' ';
2806 ++str;
2807
2808 }
2809 }
2810 c = (unsigned char) va_arg(args, int);
2811 if (str < end)
2812 *str = c;
2813 ++str;
2814 while (--spec.field_width > 0) {
2815 if (str < end)
2816 *str = ' ';
2817 ++str;
2818 }
2819 break;
2820 }
2821
2822 case FORMAT_TYPE_STR:
2823 str = string(str, end, va_arg(args, char *), spec);
2824 break;
2825
2826 case FORMAT_TYPE_PTR:
2827 str = pointer(fmt, str, end, va_arg(args, void *),
2828 spec);
2829 while (isalnum(*fmt))
2830 fmt++;
2831 break;
2832
2833 case FORMAT_TYPE_PERCENT_CHAR:
2834 if (str < end)
2835 *str = '%';
2836 ++str;
2837 break;
2838
2839 case FORMAT_TYPE_INVALID:
2840 /*
2841 * Presumably the arguments passed gcc's type
2842 * checking, but there is no safe or sane way
2843 * for us to continue parsing the format and
2844 * fetching from the va_list; the remaining
2845 * specifiers and arguments would be out of
2846 * sync.
2847 */
2848 goto out;
2849
2850 default:
2851 switch (spec.type) {
2852 case FORMAT_TYPE_LONG_LONG:
2853 num = va_arg(args, long long);
2854 break;
2855 case FORMAT_TYPE_ULONG:
2856 num = va_arg(args, unsigned long);
2857 break;
2858 case FORMAT_TYPE_LONG:
2859 num = va_arg(args, long);
2860 break;
2861 case FORMAT_TYPE_SIZE_T:
2862 if (spec.flags & SIGN)
2863 num = va_arg(args, ssize_t);
2864 else
2865 num = va_arg(args, size_t);
2866 break;
2867 case FORMAT_TYPE_PTRDIFF:
2868 num = va_arg(args, ptrdiff_t);
2869 break;
2870 case FORMAT_TYPE_UBYTE:
2871 num = (unsigned char) va_arg(args, int);
2872 break;
2873 case FORMAT_TYPE_BYTE:
2874 num = (signed char) va_arg(args, int);
2875 break;
2876 case FORMAT_TYPE_USHORT:
2877 num = (unsigned short) va_arg(args, int);
2878 break;
2879 case FORMAT_TYPE_SHORT:
2880 num = (short) va_arg(args, int);
2881 break;
2882 case FORMAT_TYPE_INT:
2883 num = (int) va_arg(args, int);
2884 break;
2885 default:
2886 num = va_arg(args, unsigned int);
2887 }
2888
2889 str = number(str, end, num, spec);
2890 }
2891 }
2892
2893 out:
2894 if (size > 0) {
2895 if (str < end)
2896 *str = '\0';
2897 else
2898 end[-1] = '\0';
2899 }
2900
2901 /* the trailing null byte doesn't count towards the total */
2902 return str-buf;
2903
2904 }
2905 EXPORT_SYMBOL(vsnprintf);
2906
2907 /**
2908 * vscnprintf - Format a string and place it in a buffer
2909 * @buf: The buffer to place the result into
2910 * @size: The size of the buffer, including the trailing null space
2911 * @fmt: The format string to use
2912 * @args: Arguments for the format string
2913 *
2914 * The return value is the number of characters which have been written into
2915 * the @buf not including the trailing '\0'. If @size is == 0 the function
2916 * returns 0.
2917 *
2918 * If you're not already dealing with a va_list consider using scnprintf().
2919 *
2920 * See the vsnprintf() documentation for format string extensions over C99.
2921 */
vscnprintf(char * buf,size_t size,const char * fmt,va_list args)2922 int vscnprintf(char *buf, size_t size, const char *fmt, va_list args)
2923 {
2924 int i;
2925
2926 if (unlikely(!size))
2927 return 0;
2928
2929 i = vsnprintf(buf, size, fmt, args);
2930
2931 if (likely(i < size))
2932 return i;
2933
2934 return size - 1;
2935 }
2936 EXPORT_SYMBOL(vscnprintf);
2937
2938 /**
2939 * snprintf - Format a string and place it in a buffer
2940 * @buf: The buffer to place the result into
2941 * @size: The size of the buffer, including the trailing null space
2942 * @fmt: The format string to use
2943 * @...: Arguments for the format string
2944 *
2945 * The return value is the number of characters which would be
2946 * generated for the given input, excluding the trailing null,
2947 * as per ISO C99. If the return is greater than or equal to
2948 * @size, the resulting string is truncated.
2949 *
2950 * See the vsnprintf() documentation for format string extensions over C99.
2951 */
snprintf(char * buf,size_t size,const char * fmt,...)2952 int snprintf(char *buf, size_t size, const char *fmt, ...)
2953 {
2954 va_list args;
2955 int i;
2956
2957 va_start(args, fmt);
2958 i = vsnprintf(buf, size, fmt, args);
2959 va_end(args);
2960
2961 return i;
2962 }
2963 EXPORT_SYMBOL(snprintf);
2964
2965 /**
2966 * scnprintf - Format a string and place it in a buffer
2967 * @buf: The buffer to place the result into
2968 * @size: The size of the buffer, including the trailing null space
2969 * @fmt: The format string to use
2970 * @...: Arguments for the format string
2971 *
2972 * The return value is the number of characters written into @buf not including
2973 * the trailing '\0'. If @size is == 0 the function returns 0.
2974 */
2975
scnprintf(char * buf,size_t size,const char * fmt,...)2976 int scnprintf(char *buf, size_t size, const char *fmt, ...)
2977 {
2978 va_list args;
2979 int i;
2980
2981 va_start(args, fmt);
2982 i = vscnprintf(buf, size, fmt, args);
2983 va_end(args);
2984
2985 return i;
2986 }
2987 EXPORT_SYMBOL(scnprintf);
2988
2989 /**
2990 * vsprintf - Format a string and place it in a buffer
2991 * @buf: The buffer to place the result into
2992 * @fmt: The format string to use
2993 * @args: Arguments for the format string
2994 *
2995 * The function returns the number of characters written
2996 * into @buf. Use vsnprintf() or vscnprintf() in order to avoid
2997 * buffer overflows.
2998 *
2999 * If you're not already dealing with a va_list consider using sprintf().
3000 *
3001 * See the vsnprintf() documentation for format string extensions over C99.
3002 */
vsprintf(char * buf,const char * fmt,va_list args)3003 int vsprintf(char *buf, const char *fmt, va_list args)
3004 {
3005 return vsnprintf(buf, INT_MAX, fmt, args);
3006 }
3007 EXPORT_SYMBOL(vsprintf);
3008
3009 /**
3010 * sprintf - Format a string and place it in a buffer
3011 * @buf: The buffer to place the result into
3012 * @fmt: The format string to use
3013 * @...: Arguments for the format string
3014 *
3015 * The function returns the number of characters written
3016 * into @buf. Use snprintf() or scnprintf() in order to avoid
3017 * buffer overflows.
3018 *
3019 * See the vsnprintf() documentation for format string extensions over C99.
3020 */
sprintf(char * buf,const char * fmt,...)3021 int sprintf(char *buf, const char *fmt, ...)
3022 {
3023 va_list args;
3024 int i;
3025
3026 va_start(args, fmt);
3027 i = vsnprintf(buf, INT_MAX, fmt, args);
3028 va_end(args);
3029
3030 return i;
3031 }
3032 EXPORT_SYMBOL(sprintf);
3033
3034 #ifdef CONFIG_BINARY_PRINTF
3035 /*
3036 * bprintf service:
3037 * vbin_printf() - VA arguments to binary data
3038 * bstr_printf() - Binary data to text string
3039 */
3040
3041 /**
3042 * vbin_printf - Parse a format string and place args' binary value in a buffer
3043 * @bin_buf: The buffer to place args' binary value
3044 * @size: The size of the buffer(by words(32bits), not characters)
3045 * @fmt: The format string to use
3046 * @args: Arguments for the format string
3047 *
3048 * The format follows C99 vsnprintf, except %n is ignored, and its argument
3049 * is skipped.
3050 *
3051 * The return value is the number of words(32bits) which would be generated for
3052 * the given input.
3053 *
3054 * NOTE:
3055 * If the return value is greater than @size, the resulting bin_buf is NOT
3056 * valid for bstr_printf().
3057 */
vbin_printf(u32 * bin_buf,size_t size,const char * fmt,va_list args)3058 int vbin_printf(u32 *bin_buf, size_t size, const char *fmt, va_list args)
3059 {
3060 struct printf_spec spec = {0};
3061 char *str, *end;
3062 int width;
3063
3064 str = (char *)bin_buf;
3065 end = (char *)(bin_buf + size);
3066
3067 #define save_arg(type) \
3068 ({ \
3069 unsigned long long value; \
3070 if (sizeof(type) == 8) { \
3071 unsigned long long val8; \
3072 str = PTR_ALIGN(str, sizeof(u32)); \
3073 val8 = va_arg(args, unsigned long long); \
3074 if (str + sizeof(type) <= end) { \
3075 *(u32 *)str = *(u32 *)&val8; \
3076 *(u32 *)(str + 4) = *((u32 *)&val8 + 1); \
3077 } \
3078 value = val8; \
3079 } else { \
3080 unsigned int val4; \
3081 str = PTR_ALIGN(str, sizeof(type)); \
3082 val4 = va_arg(args, int); \
3083 if (str + sizeof(type) <= end) \
3084 *(typeof(type) *)str = (type)(long)val4; \
3085 value = (unsigned long long)val4; \
3086 } \
3087 str += sizeof(type); \
3088 value; \
3089 })
3090
3091 while (*fmt) {
3092 int read = format_decode(fmt, &spec);
3093
3094 fmt += read;
3095
3096 switch (spec.type) {
3097 case FORMAT_TYPE_NONE:
3098 case FORMAT_TYPE_PERCENT_CHAR:
3099 break;
3100 case FORMAT_TYPE_INVALID:
3101 goto out;
3102
3103 case FORMAT_TYPE_WIDTH:
3104 case FORMAT_TYPE_PRECISION:
3105 width = (int)save_arg(int);
3106 /* Pointers may require the width */
3107 if (*fmt == 'p')
3108 set_field_width(&spec, width);
3109 break;
3110
3111 case FORMAT_TYPE_CHAR:
3112 save_arg(char);
3113 break;
3114
3115 case FORMAT_TYPE_STR: {
3116 const char *save_str = va_arg(args, char *);
3117 const char *err_msg;
3118 size_t len;
3119
3120 err_msg = check_pointer_msg(save_str);
3121 if (err_msg)
3122 save_str = err_msg;
3123
3124 len = strlen(save_str) + 1;
3125 if (str + len < end)
3126 memcpy(str, save_str, len);
3127 str += len;
3128 break;
3129 }
3130
3131 case FORMAT_TYPE_PTR:
3132 /* Dereferenced pointers must be done now */
3133 switch (*fmt) {
3134 /* Dereference of functions is still OK */
3135 case 'S':
3136 case 's':
3137 case 'x':
3138 case 'K':
3139 case 'e':
3140 save_arg(void *);
3141 break;
3142 default:
3143 if (!isalnum(*fmt)) {
3144 save_arg(void *);
3145 break;
3146 }
3147 str = pointer(fmt, str, end, va_arg(args, void *),
3148 spec);
3149 if (str + 1 < end)
3150 *str++ = '\0';
3151 else
3152 end[-1] = '\0'; /* Must be nul terminated */
3153 }
3154 /* skip all alphanumeric pointer suffixes */
3155 while (isalnum(*fmt))
3156 fmt++;
3157 break;
3158
3159 default:
3160 switch (spec.type) {
3161
3162 case FORMAT_TYPE_LONG_LONG:
3163 save_arg(long long);
3164 break;
3165 case FORMAT_TYPE_ULONG:
3166 case FORMAT_TYPE_LONG:
3167 save_arg(unsigned long);
3168 break;
3169 case FORMAT_TYPE_SIZE_T:
3170 save_arg(size_t);
3171 break;
3172 case FORMAT_TYPE_PTRDIFF:
3173 save_arg(ptrdiff_t);
3174 break;
3175 case FORMAT_TYPE_UBYTE:
3176 case FORMAT_TYPE_BYTE:
3177 save_arg(char);
3178 break;
3179 case FORMAT_TYPE_USHORT:
3180 case FORMAT_TYPE_SHORT:
3181 save_arg(short);
3182 break;
3183 default:
3184 save_arg(int);
3185 }
3186 }
3187 }
3188
3189 out:
3190 return (u32 *)(PTR_ALIGN(str, sizeof(u32))) - bin_buf;
3191 #undef save_arg
3192 }
3193 EXPORT_SYMBOL_GPL(vbin_printf);
3194
3195 /**
3196 * bstr_printf - Format a string from binary arguments and place it in a buffer
3197 * @buf: The buffer to place the result into
3198 * @size: The size of the buffer, including the trailing null space
3199 * @fmt: The format string to use
3200 * @bin_buf: Binary arguments for the format string
3201 *
3202 * This function like C99 vsnprintf, but the difference is that vsnprintf gets
3203 * arguments from stack, and bstr_printf gets arguments from @bin_buf which is
3204 * a binary buffer that generated by vbin_printf.
3205 *
3206 * The format follows C99 vsnprintf, but has some extensions:
3207 * see vsnprintf comment for details.
3208 *
3209 * The return value is the number of characters which would
3210 * be generated for the given input, excluding the trailing
3211 * '\0', as per ISO C99. If you want to have the exact
3212 * number of characters written into @buf as return value
3213 * (not including the trailing '\0'), use vscnprintf(). If the
3214 * return is greater than or equal to @size, the resulting
3215 * string is truncated.
3216 */
bstr_printf(char * buf,size_t size,const char * fmt,const u32 * bin_buf)3217 int bstr_printf(char *buf, size_t size, const char *fmt, const u32 *bin_buf)
3218 {
3219 struct printf_spec spec = {0};
3220 char *str, *end;
3221 const char *args = (const char *)bin_buf;
3222
3223 if (WARN_ON_ONCE(size > INT_MAX))
3224 return 0;
3225
3226 str = buf;
3227 end = buf + size;
3228
3229 #define get_arg(type) \
3230 ({ \
3231 typeof(type) value; \
3232 if (sizeof(type) == 8) { \
3233 args = PTR_ALIGN(args, sizeof(u32)); \
3234 *(u32 *)&value = *(u32 *)args; \
3235 *((u32 *)&value + 1) = *(u32 *)(args + 4); \
3236 } else { \
3237 args = PTR_ALIGN(args, sizeof(type)); \
3238 value = *(typeof(type) *)args; \
3239 } \
3240 args += sizeof(type); \
3241 value; \
3242 })
3243
3244 /* Make sure end is always >= buf */
3245 if (end < buf) {
3246 end = ((void *)-1);
3247 size = end - buf;
3248 }
3249
3250 while (*fmt) {
3251 const char *old_fmt = fmt;
3252 int read = format_decode(fmt, &spec);
3253
3254 fmt += read;
3255
3256 switch (spec.type) {
3257 case FORMAT_TYPE_NONE: {
3258 int copy = read;
3259 if (str < end) {
3260 if (copy > end - str)
3261 copy = end - str;
3262 memcpy(str, old_fmt, copy);
3263 }
3264 str += read;
3265 break;
3266 }
3267
3268 case FORMAT_TYPE_WIDTH:
3269 set_field_width(&spec, get_arg(int));
3270 break;
3271
3272 case FORMAT_TYPE_PRECISION:
3273 set_precision(&spec, get_arg(int));
3274 break;
3275
3276 case FORMAT_TYPE_CHAR: {
3277 char c;
3278
3279 if (!(spec.flags & LEFT)) {
3280 while (--spec.field_width > 0) {
3281 if (str < end)
3282 *str = ' ';
3283 ++str;
3284 }
3285 }
3286 c = (unsigned char) get_arg(char);
3287 if (str < end)
3288 *str = c;
3289 ++str;
3290 while (--spec.field_width > 0) {
3291 if (str < end)
3292 *str = ' ';
3293 ++str;
3294 }
3295 break;
3296 }
3297
3298 case FORMAT_TYPE_STR: {
3299 const char *str_arg = args;
3300 args += strlen(str_arg) + 1;
3301 str = string(str, end, (char *)str_arg, spec);
3302 break;
3303 }
3304
3305 case FORMAT_TYPE_PTR: {
3306 bool process = false;
3307 int copy, len;
3308 /* Non function dereferences were already done */
3309 switch (*fmt) {
3310 case 'S':
3311 case 's':
3312 case 'x':
3313 case 'K':
3314 case 'e':
3315 process = true;
3316 break;
3317 default:
3318 if (!isalnum(*fmt)) {
3319 process = true;
3320 break;
3321 }
3322 /* Pointer dereference was already processed */
3323 if (str < end) {
3324 len = copy = strlen(args);
3325 if (copy > end - str)
3326 copy = end - str;
3327 memcpy(str, args, copy);
3328 str += len;
3329 args += len + 1;
3330 }
3331 }
3332 if (process)
3333 str = pointer(fmt, str, end, get_arg(void *), spec);
3334
3335 while (isalnum(*fmt))
3336 fmt++;
3337 break;
3338 }
3339
3340 case FORMAT_TYPE_PERCENT_CHAR:
3341 if (str < end)
3342 *str = '%';
3343 ++str;
3344 break;
3345
3346 case FORMAT_TYPE_INVALID:
3347 goto out;
3348
3349 default: {
3350 unsigned long long num;
3351
3352 switch (spec.type) {
3353
3354 case FORMAT_TYPE_LONG_LONG:
3355 num = get_arg(long long);
3356 break;
3357 case FORMAT_TYPE_ULONG:
3358 case FORMAT_TYPE_LONG:
3359 num = get_arg(unsigned long);
3360 break;
3361 case FORMAT_TYPE_SIZE_T:
3362 num = get_arg(size_t);
3363 break;
3364 case FORMAT_TYPE_PTRDIFF:
3365 num = get_arg(ptrdiff_t);
3366 break;
3367 case FORMAT_TYPE_UBYTE:
3368 num = get_arg(unsigned char);
3369 break;
3370 case FORMAT_TYPE_BYTE:
3371 num = get_arg(signed char);
3372 break;
3373 case FORMAT_TYPE_USHORT:
3374 num = get_arg(unsigned short);
3375 break;
3376 case FORMAT_TYPE_SHORT:
3377 num = get_arg(short);
3378 break;
3379 case FORMAT_TYPE_UINT:
3380 num = get_arg(unsigned int);
3381 break;
3382 default:
3383 num = get_arg(int);
3384 }
3385
3386 str = number(str, end, num, spec);
3387 } /* default: */
3388 } /* switch(spec.type) */
3389 } /* while(*fmt) */
3390
3391 out:
3392 if (size > 0) {
3393 if (str < end)
3394 *str = '\0';
3395 else
3396 end[-1] = '\0';
3397 }
3398
3399 #undef get_arg
3400
3401 /* the trailing null byte doesn't count towards the total */
3402 return str - buf;
3403 }
3404 EXPORT_SYMBOL_GPL(bstr_printf);
3405
3406 /**
3407 * bprintf - Parse a format string and place args' binary value in a buffer
3408 * @bin_buf: The buffer to place args' binary value
3409 * @size: The size of the buffer(by words(32bits), not characters)
3410 * @fmt: The format string to use
3411 * @...: Arguments for the format string
3412 *
3413 * The function returns the number of words(u32) written
3414 * into @bin_buf.
3415 */
bprintf(u32 * bin_buf,size_t size,const char * fmt,...)3416 int bprintf(u32 *bin_buf, size_t size, const char *fmt, ...)
3417 {
3418 va_list args;
3419 int ret;
3420
3421 va_start(args, fmt);
3422 ret = vbin_printf(bin_buf, size, fmt, args);
3423 va_end(args);
3424
3425 return ret;
3426 }
3427 EXPORT_SYMBOL_GPL(bprintf);
3428
3429 #endif /* CONFIG_BINARY_PRINTF */
3430
3431 /**
3432 * vsscanf - Unformat a buffer into a list of arguments
3433 * @buf: input buffer
3434 * @fmt: format of buffer
3435 * @args: arguments
3436 */
vsscanf(const char * buf,const char * fmt,va_list args)3437 int vsscanf(const char *buf, const char *fmt, va_list args)
3438 {
3439 const char *str = buf;
3440 char *next;
3441 char digit;
3442 int num = 0;
3443 u8 qualifier;
3444 unsigned int base;
3445 union {
3446 long long s;
3447 unsigned long long u;
3448 } val;
3449 s16 field_width;
3450 bool is_sign;
3451
3452 while (*fmt) {
3453 /* skip any white space in format */
3454 /* white space in format matches any amount of
3455 * white space, including none, in the input.
3456 */
3457 if (isspace(*fmt)) {
3458 fmt = skip_spaces(++fmt);
3459 str = skip_spaces(str);
3460 }
3461
3462 /* anything that is not a conversion must match exactly */
3463 if (*fmt != '%' && *fmt) {
3464 if (*fmt++ != *str++)
3465 break;
3466 continue;
3467 }
3468
3469 if (!*fmt)
3470 break;
3471 ++fmt;
3472
3473 /* skip this conversion.
3474 * advance both strings to next white space
3475 */
3476 if (*fmt == '*') {
3477 if (!*str)
3478 break;
3479 while (!isspace(*fmt) && *fmt != '%' && *fmt) {
3480 /* '%*[' not yet supported, invalid format */
3481 if (*fmt == '[')
3482 return num;
3483 fmt++;
3484 }
3485 while (!isspace(*str) && *str)
3486 str++;
3487 continue;
3488 }
3489
3490 /* get field width */
3491 field_width = -1;
3492 if (isdigit(*fmt)) {
3493 field_width = skip_atoi(&fmt);
3494 if (field_width <= 0)
3495 break;
3496 }
3497
3498 /* get conversion qualifier */
3499 qualifier = -1;
3500 if (*fmt == 'h' || _tolower(*fmt) == 'l' ||
3501 *fmt == 'z') {
3502 qualifier = *fmt++;
3503 if (unlikely(qualifier == *fmt)) {
3504 if (qualifier == 'h') {
3505 qualifier = 'H';
3506 fmt++;
3507 } else if (qualifier == 'l') {
3508 qualifier = 'L';
3509 fmt++;
3510 }
3511 }
3512 }
3513
3514 if (!*fmt)
3515 break;
3516
3517 if (*fmt == 'n') {
3518 /* return number of characters read so far */
3519 *va_arg(args, int *) = str - buf;
3520 ++fmt;
3521 continue;
3522 }
3523
3524 if (!*str)
3525 break;
3526
3527 base = 10;
3528 is_sign = false;
3529
3530 switch (*fmt++) {
3531 case 'c':
3532 {
3533 char *s = (char *)va_arg(args, char*);
3534 if (field_width == -1)
3535 field_width = 1;
3536 do {
3537 *s++ = *str++;
3538 } while (--field_width > 0 && *str);
3539 num++;
3540 }
3541 continue;
3542 case 's':
3543 {
3544 char *s = (char *)va_arg(args, char *);
3545 if (field_width == -1)
3546 field_width = SHRT_MAX;
3547 /* first, skip leading white space in buffer */
3548 str = skip_spaces(str);
3549
3550 /* now copy until next white space */
3551 while (*str && !isspace(*str) && field_width--)
3552 *s++ = *str++;
3553 *s = '\0';
3554 num++;
3555 }
3556 continue;
3557 /*
3558 * Warning: This implementation of the '[' conversion specifier
3559 * deviates from its glibc counterpart in the following ways:
3560 * (1) It does NOT support ranges i.e. '-' is NOT a special
3561 * character
3562 * (2) It cannot match the closing bracket ']' itself
3563 * (3) A field width is required
3564 * (4) '%*[' (discard matching input) is currently not supported
3565 *
3566 * Example usage:
3567 * ret = sscanf("00:0a:95","%2[^:]:%2[^:]:%2[^:]",
3568 * buf1, buf2, buf3);
3569 * if (ret < 3)
3570 * // etc..
3571 */
3572 case '[':
3573 {
3574 char *s = (char *)va_arg(args, char *);
3575 DECLARE_BITMAP(set, 256) = {0};
3576 unsigned int len = 0;
3577 bool negate = (*fmt == '^');
3578
3579 /* field width is required */
3580 if (field_width == -1)
3581 return num;
3582
3583 if (negate)
3584 ++fmt;
3585
3586 for ( ; *fmt && *fmt != ']'; ++fmt, ++len)
3587 __set_bit((u8)*fmt, set);
3588
3589 /* no ']' or no character set found */
3590 if (!*fmt || !len)
3591 return num;
3592 ++fmt;
3593
3594 if (negate) {
3595 bitmap_complement(set, set, 256);
3596 /* exclude null '\0' byte */
3597 __clear_bit(0, set);
3598 }
3599
3600 /* match must be non-empty */
3601 if (!test_bit((u8)*str, set))
3602 return num;
3603
3604 while (test_bit((u8)*str, set) && field_width--)
3605 *s++ = *str++;
3606 *s = '\0';
3607 ++num;
3608 }
3609 continue;
3610 case 'o':
3611 base = 8;
3612 break;
3613 case 'x':
3614 case 'X':
3615 base = 16;
3616 break;
3617 case 'i':
3618 base = 0;
3619 fallthrough;
3620 case 'd':
3621 is_sign = true;
3622 fallthrough;
3623 case 'u':
3624 break;
3625 case '%':
3626 /* looking for '%' in str */
3627 if (*str++ != '%')
3628 return num;
3629 continue;
3630 default:
3631 /* invalid format; stop here */
3632 return num;
3633 }
3634
3635 /* have some sort of integer conversion.
3636 * first, skip white space in buffer.
3637 */
3638 str = skip_spaces(str);
3639
3640 digit = *str;
3641 if (is_sign && digit == '-') {
3642 if (field_width == 1)
3643 break;
3644
3645 digit = *(str + 1);
3646 }
3647
3648 if (!digit
3649 || (base == 16 && !isxdigit(digit))
3650 || (base == 10 && !isdigit(digit))
3651 || (base == 8 && !isodigit(digit))
3652 || (base == 0 && !isdigit(digit)))
3653 break;
3654
3655 if (is_sign)
3656 val.s = simple_strntoll(str,
3657 field_width >= 0 ? field_width : INT_MAX,
3658 &next, base);
3659 else
3660 val.u = simple_strntoull(str,
3661 field_width >= 0 ? field_width : INT_MAX,
3662 &next, base);
3663
3664 switch (qualifier) {
3665 case 'H': /* that's 'hh' in format */
3666 if (is_sign)
3667 *va_arg(args, signed char *) = val.s;
3668 else
3669 *va_arg(args, unsigned char *) = val.u;
3670 break;
3671 case 'h':
3672 if (is_sign)
3673 *va_arg(args, short *) = val.s;
3674 else
3675 *va_arg(args, unsigned short *) = val.u;
3676 break;
3677 case 'l':
3678 if (is_sign)
3679 *va_arg(args, long *) = val.s;
3680 else
3681 *va_arg(args, unsigned long *) = val.u;
3682 break;
3683 case 'L':
3684 if (is_sign)
3685 *va_arg(args, long long *) = val.s;
3686 else
3687 *va_arg(args, unsigned long long *) = val.u;
3688 break;
3689 case 'z':
3690 *va_arg(args, size_t *) = val.u;
3691 break;
3692 default:
3693 if (is_sign)
3694 *va_arg(args, int *) = val.s;
3695 else
3696 *va_arg(args, unsigned int *) = val.u;
3697 break;
3698 }
3699 num++;
3700
3701 if (!next)
3702 break;
3703 str = next;
3704 }
3705
3706 return num;
3707 }
3708 EXPORT_SYMBOL(vsscanf);
3709
3710 /**
3711 * sscanf - Unformat a buffer into a list of arguments
3712 * @buf: input buffer
3713 * @fmt: formatting of buffer
3714 * @...: resulting arguments
3715 */
sscanf(const char * buf,const char * fmt,...)3716 int sscanf(const char *buf, const char *fmt, ...)
3717 {
3718 va_list args;
3719 int i;
3720
3721 va_start(args, fmt);
3722 i = vsscanf(buf, fmt, args);
3723 va_end(args);
3724
3725 return i;
3726 }
3727 EXPORT_SYMBOL(sscanf);
3728