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