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