1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * linux/lib/vsprintf.c
4 *
5 * Copyright (C) 1991, 1992 Linus Torvalds
6 */
7
8 /* vsprintf.c -- Lars Wirzenius & Linus Torvalds. */
9 /*
10 * Wirzenius wrote this portably, Torvalds fucked it up :-)
11 */
12
13 /*
14 * Fri Jul 13 2001 Crutcher Dunnavant <crutcher+kernel@datastacks.com>
15 * - changed to provide snprintf and vsnprintf functions
16 * So Feb 1 16:51:32 CET 2004 Juergen Quade <quade@hsnr.de>
17 * - scnprintf and vscnprintf
18 */
19
20 #include <linux/stdarg.h>
21 #include <linux/build_bug.h>
22 #include <linux/clk.h>
23 #include <linux/clk-provider.h>
24 #include <linux/errname.h>
25 #include <linux/module.h> /* for KSYM_SYMBOL_LEN */
26 #include <linux/types.h>
27 #include <linux/string.h>
28 #include <linux/ctype.h>
29 #include <linux/kernel.h>
30 #include <linux/kallsyms.h>
31 #include <linux/math64.h>
32 #include <linux/uaccess.h>
33 #include <linux/ioport.h>
34 #include <linux/dcache.h>
35 #include <linux/cred.h>
36 #include <linux/rtc.h>
37 #include <linux/sprintf.h>
38 #include <linux/time.h>
39 #include <linux/uuid.h>
40 #include <linux/of.h>
41 #include <net/addrconf.h>
42 #include <linux/siphash.h>
43 #include <linux/compiler.h>
44 #include <linux/property.h>
45 #include <linux/notifier.h>
46 #ifdef CONFIG_BLOCK
47 #include <linux/blkdev.h>
48 #endif
49
50 #include "../mm/internal.h" /* For the trace_print_flags arrays */
51
52 #include <asm/page.h> /* for PAGE_SIZE */
53 #include <asm/byteorder.h> /* cpu_to_le16 */
54 #include <linux/unaligned.h>
55
56 #include <linux/string_helpers.h>
57 #include "kstrtox.h"
58
59 /* Disable pointer hashing if requested */
60 bool no_hash_pointers __ro_after_init;
61 EXPORT_SYMBOL_GPL(no_hash_pointers);
62
63 /*
64 * Hashed pointers policy selected by "hash_pointers=..." boot param
65 *
66 * `auto` - Hashed pointers enabled unless disabled by slub_debug_enabled=true
67 * `always` - Hashed pointers enabled unconditionally
68 * `never` - Hashed pointers disabled unconditionally
69 */
70 enum hash_pointers_policy {
71 HASH_PTR_AUTO = 0,
72 HASH_PTR_ALWAYS,
73 HASH_PTR_NEVER
74 };
75 static enum hash_pointers_policy hash_pointers_mode __initdata;
76
77 noinline
simple_strntoull(const char * startp,char ** endp,unsigned int base,size_t max_chars)78 static unsigned long long simple_strntoull(const char *startp, char **endp, unsigned int base, size_t max_chars)
79 {
80 const char *cp;
81 unsigned long long result = 0ULL;
82 size_t prefix_chars;
83 unsigned int rv;
84
85 cp = _parse_integer_fixup_radix(startp, &base);
86 prefix_chars = cp - startp;
87 if (prefix_chars < max_chars) {
88 rv = _parse_integer_limit(cp, base, &result, max_chars - prefix_chars);
89 /* FIXME */
90 cp += (rv & ~KSTRTOX_OVERFLOW);
91 } else {
92 /* Field too short for prefix + digit, skip over without converting */
93 cp = startp + max_chars;
94 }
95
96 if (endp)
97 *endp = (char *)cp;
98
99 return result;
100 }
101
102 /**
103 * simple_strtoull - convert a string to an unsigned long long
104 * @cp: The start of the string
105 * @endp: A pointer to the end of the parsed string will be placed here
106 * @base: The number base to use
107 *
108 * This function has caveats. Please use kstrtoull instead.
109 */
110 noinline
simple_strtoull(const char * cp,char ** endp,unsigned int base)111 unsigned long long simple_strtoull(const char *cp, char **endp, unsigned int base)
112 {
113 return simple_strntoull(cp, endp, base, INT_MAX);
114 }
115 EXPORT_SYMBOL(simple_strtoull);
116
117 /**
118 * simple_strtoul - convert a string to an unsigned long
119 * @cp: The start of the string
120 * @endp: A pointer to the end of the parsed string will be placed here
121 * @base: The number base to use
122 *
123 * This function has caveats. Please use kstrtoul instead.
124 */
simple_strtoul(const char * cp,char ** endp,unsigned int base)125 unsigned long simple_strtoul(const char *cp, char **endp, unsigned int base)
126 {
127 return simple_strtoull(cp, endp, base);
128 }
129 EXPORT_SYMBOL(simple_strtoul);
130
simple_strntoul(const char * cp,char ** endp,unsigned int base,size_t max_chars)131 unsigned long simple_strntoul(const char *cp, char **endp, unsigned int base,
132 size_t max_chars)
133 {
134 return simple_strntoull(cp, endp, base, max_chars);
135 }
136 EXPORT_SYMBOL(simple_strntoul);
137
138 /**
139 * simple_strtol - convert a string to a signed long
140 * @cp: The start of the string
141 * @endp: A pointer to the end of the parsed string will be placed here
142 * @base: The number base to use
143 *
144 * This function has caveats. Please use kstrtol instead.
145 */
simple_strtol(const char * cp,char ** endp,unsigned int base)146 long simple_strtol(const char *cp, char **endp, unsigned int base)
147 {
148 if (*cp == '-')
149 return -simple_strtoul(cp + 1, endp, base);
150
151 return simple_strtoul(cp, endp, base);
152 }
153 EXPORT_SYMBOL(simple_strtol);
154
155 noinline
simple_strntoll(const char * cp,char ** endp,unsigned int base,size_t max_chars)156 static long long simple_strntoll(const char *cp, char **endp, unsigned int base, size_t max_chars)
157 {
158 /*
159 * simple_strntoull() safely handles receiving max_chars==0 in the
160 * case cp[0] == '-' && max_chars == 1.
161 * If max_chars == 0 we can drop through and pass it to simple_strntoull()
162 * and the content of *cp is irrelevant.
163 */
164 if (*cp == '-' && max_chars > 0)
165 return -simple_strntoull(cp + 1, endp, base, max_chars - 1);
166
167 return simple_strntoull(cp, endp, base, max_chars);
168 }
169
170 /**
171 * simple_strtoll - convert a string to a signed long long
172 * @cp: The start of the string
173 * @endp: A pointer to the end of the parsed string will be placed here
174 * @base: The number base to use
175 *
176 * This function has caveats. Please use kstrtoll instead.
177 */
simple_strtoll(const char * cp,char ** endp,unsigned int base)178 long long simple_strtoll(const char *cp, char **endp, unsigned int base)
179 {
180 return simple_strntoll(cp, endp, base, INT_MAX);
181 }
182 EXPORT_SYMBOL(simple_strtoll);
183
skip_atoi(const char ** s)184 static inline int skip_atoi(const char **s)
185 {
186 int i = 0;
187
188 do {
189 i = i*10 + *((*s)++) - '0';
190 } while (isdigit(**s));
191
192 return i;
193 }
194
195 /*
196 * Decimal conversion is by far the most typical, and is used for
197 * /proc and /sys data. This directly impacts e.g. top performance
198 * with many processes running. We optimize it for speed by emitting
199 * two characters at a time, using a 200 byte lookup table. This
200 * roughly halves the number of multiplications compared to computing
201 * the digits one at a time. Implementation strongly inspired by the
202 * previous version, which in turn used ideas described at
203 * <http://www.cs.uiowa.edu/~jones/bcd/divide.html> (with permission
204 * from the author, Douglas W. Jones).
205 *
206 * It turns out there is precisely one 26 bit fixed-point
207 * approximation a of 64/100 for which x/100 == (x * (u64)a) >> 32
208 * holds for all x in [0, 10^8-1], namely a = 0x28f5c29. The actual
209 * range happens to be somewhat larger (x <= 1073741898), but that's
210 * irrelevant for our purpose.
211 *
212 * For dividing a number in the range [10^4, 10^6-1] by 100, we still
213 * need a 32x32->64 bit multiply, so we simply use the same constant.
214 *
215 * For dividing a number in the range [100, 10^4-1] by 100, there are
216 * several options. The simplest is (x * 0x147b) >> 19, which is valid
217 * for all x <= 43698.
218 */
219
220 static const u16 decpair[100] = {
221 #define _(x) (__force u16) cpu_to_le16(((x % 10) | ((x / 10) << 8)) + 0x3030)
222 _( 0), _( 1), _( 2), _( 3), _( 4), _( 5), _( 6), _( 7), _( 8), _( 9),
223 _(10), _(11), _(12), _(13), _(14), _(15), _(16), _(17), _(18), _(19),
224 _(20), _(21), _(22), _(23), _(24), _(25), _(26), _(27), _(28), _(29),
225 _(30), _(31), _(32), _(33), _(34), _(35), _(36), _(37), _(38), _(39),
226 _(40), _(41), _(42), _(43), _(44), _(45), _(46), _(47), _(48), _(49),
227 _(50), _(51), _(52), _(53), _(54), _(55), _(56), _(57), _(58), _(59),
228 _(60), _(61), _(62), _(63), _(64), _(65), _(66), _(67), _(68), _(69),
229 _(70), _(71), _(72), _(73), _(74), _(75), _(76), _(77), _(78), _(79),
230 _(80), _(81), _(82), _(83), _(84), _(85), _(86), _(87), _(88), _(89),
231 _(90), _(91), _(92), _(93), _(94), _(95), _(96), _(97), _(98), _(99),
232 #undef _
233 };
234
235 /*
236 * This will print a single '0' even if r == 0, since we would
237 * immediately jump to out_r where two 0s would be written but only
238 * one of them accounted for in buf. This is needed by ip4_string
239 * below. All other callers pass a non-zero value of r.
240 */
241 static noinline_for_stack
put_dec_trunc8(char * buf,unsigned r)242 char *put_dec_trunc8(char *buf, unsigned r)
243 {
244 unsigned q;
245
246 /* 1 <= r < 10^8 */
247 if (r < 100)
248 goto out_r;
249
250 /* 100 <= r < 10^8 */
251 q = (r * (u64)0x28f5c29) >> 32;
252 *((u16 *)buf) = decpair[r - 100*q];
253 buf += 2;
254
255 /* 1 <= q < 10^6 */
256 if (q < 100)
257 goto out_q;
258
259 /* 100 <= q < 10^6 */
260 r = (q * (u64)0x28f5c29) >> 32;
261 *((u16 *)buf) = decpair[q - 100*r];
262 buf += 2;
263
264 /* 1 <= r < 10^4 */
265 if (r < 100)
266 goto out_r;
267
268 /* 100 <= r < 10^4 */
269 q = (r * 0x147b) >> 19;
270 *((u16 *)buf) = decpair[r - 100*q];
271 buf += 2;
272 out_q:
273 /* 1 <= q < 100 */
274 r = q;
275 out_r:
276 /* 1 <= r < 100 */
277 *((u16 *)buf) = decpair[r];
278 buf += r < 10 ? 1 : 2;
279 return buf;
280 }
281
282 #if BITS_PER_LONG == 64 && BITS_PER_LONG_LONG == 64
283 static noinline_for_stack
put_dec_full8(char * buf,unsigned r)284 char *put_dec_full8(char *buf, unsigned r)
285 {
286 unsigned q;
287
288 /* 0 <= r < 10^8 */
289 q = (r * (u64)0x28f5c29) >> 32;
290 *((u16 *)buf) = decpair[r - 100*q];
291 buf += 2;
292
293 /* 0 <= q < 10^6 */
294 r = (q * (u64)0x28f5c29) >> 32;
295 *((u16 *)buf) = decpair[q - 100*r];
296 buf += 2;
297
298 /* 0 <= r < 10^4 */
299 q = (r * 0x147b) >> 19;
300 *((u16 *)buf) = decpair[r - 100*q];
301 buf += 2;
302
303 /* 0 <= q < 100 */
304 *((u16 *)buf) = decpair[q];
305 buf += 2;
306 return buf;
307 }
308
309 static noinline_for_stack
put_dec(char * buf,unsigned long long n)310 char *put_dec(char *buf, unsigned long long n)
311 {
312 if (n >= 100*1000*1000)
313 buf = put_dec_full8(buf, do_div(n, 100*1000*1000));
314 /* 1 <= n <= 1.6e11 */
315 if (n >= 100*1000*1000)
316 buf = put_dec_full8(buf, do_div(n, 100*1000*1000));
317 /* 1 <= n < 1e8 */
318 return put_dec_trunc8(buf, n);
319 }
320
321 #elif BITS_PER_LONG == 32 && BITS_PER_LONG_LONG == 64
322
323 static void
put_dec_full4(char * buf,unsigned r)324 put_dec_full4(char *buf, unsigned r)
325 {
326 unsigned q;
327
328 /* 0 <= r < 10^4 */
329 q = (r * 0x147b) >> 19;
330 *((u16 *)buf) = decpair[r - 100*q];
331 buf += 2;
332 /* 0 <= q < 100 */
333 *((u16 *)buf) = decpair[q];
334 }
335
336 /*
337 * Call put_dec_full4 on x % 10000, return x / 10000.
338 * The approximation x/10000 == (x * 0x346DC5D7) >> 43
339 * holds for all x < 1,128,869,999. The largest value this
340 * helper will ever be asked to convert is 1,125,520,955.
341 * (second call in the put_dec code, assuming n is all-ones).
342 */
343 static noinline_for_stack
put_dec_helper4(char * buf,unsigned x)344 unsigned put_dec_helper4(char *buf, unsigned x)
345 {
346 uint32_t q = (x * (uint64_t)0x346DC5D7) >> 43;
347
348 put_dec_full4(buf, x - q * 10000);
349 return q;
350 }
351
352 /* Based on code by Douglas W. Jones found at
353 * <http://www.cs.uiowa.edu/~jones/bcd/decimal.html#sixtyfour>
354 * (with permission from the author).
355 * Performs no 64-bit division and hence should be fast on 32-bit machines.
356 */
357 static
put_dec(char * buf,unsigned long long n)358 char *put_dec(char *buf, unsigned long long n)
359 {
360 uint32_t d3, d2, d1, q, h;
361
362 if (n < 100*1000*1000)
363 return put_dec_trunc8(buf, n);
364
365 d1 = ((uint32_t)n >> 16); /* implicit "& 0xffff" */
366 h = (n >> 32);
367 d2 = (h ) & 0xffff;
368 d3 = (h >> 16); /* implicit "& 0xffff" */
369
370 /* n = 2^48 d3 + 2^32 d2 + 2^16 d1 + d0
371 = 281_4749_7671_0656 d3 + 42_9496_7296 d2 + 6_5536 d1 + d0 */
372 q = 656 * d3 + 7296 * d2 + 5536 * d1 + ((uint32_t)n & 0xffff);
373 q = put_dec_helper4(buf, q);
374
375 q += 7671 * d3 + 9496 * d2 + 6 * d1;
376 q = put_dec_helper4(buf+4, q);
377
378 q += 4749 * d3 + 42 * d2;
379 q = put_dec_helper4(buf+8, q);
380
381 q += 281 * d3;
382 buf += 12;
383 if (q)
384 buf = put_dec_trunc8(buf, q);
385 else while (buf[-1] == '0')
386 --buf;
387
388 return buf;
389 }
390
391 #endif
392
393 /*
394 * Convert passed number to decimal string.
395 * Returns the length of string. On buffer overflow, returns 0.
396 *
397 * If speed is not important, use snprintf(). It's easy to read the code.
398 */
num_to_str(char * buf,int size,unsigned long long num,unsigned int width)399 int num_to_str(char *buf, int size, unsigned long long num, unsigned int width)
400 {
401 /* put_dec requires 2-byte alignment of the buffer. */
402 char tmp[sizeof(num) * 3] __aligned(2);
403 int idx, len;
404
405 /* put_dec() may work incorrectly for num = 0 (generate "", not "0") */
406 if (num <= 9) {
407 tmp[0] = '0' + num;
408 len = 1;
409 } else {
410 len = put_dec(tmp, num) - tmp;
411 }
412
413 if (len > size || width > size)
414 return 0;
415
416 if (width > len) {
417 width = width - len;
418 for (idx = 0; idx < width; idx++)
419 buf[idx] = ' ';
420 } else {
421 width = 0;
422 }
423
424 for (idx = 0; idx < len; ++idx)
425 buf[idx + width] = tmp[len - idx - 1];
426
427 return len + width;
428 }
429
430 #define SIGN 1 /* unsigned/signed */
431 #define LEFT 2 /* left justified */
432 #define PLUS 4 /* show plus */
433 #define SPACE 8 /* space if plus */
434 #define ZEROPAD 16 /* pad with zero, must be 16 == '0' - ' ' */
435 #define SMALL 32 /* use lowercase in hex (must be 32 == 0x20) */
436 #define SPECIAL 64 /* prefix hex with "0x", octal with "0" */
437
438 static_assert(ZEROPAD == ('0' - ' '));
439 static_assert(SMALL == ('a' ^ 'A'));
440
441 enum format_state {
442 FORMAT_STATE_NONE, /* Just a string part */
443 FORMAT_STATE_NUM,
444 FORMAT_STATE_WIDTH,
445 FORMAT_STATE_PRECISION,
446 FORMAT_STATE_CHAR,
447 FORMAT_STATE_STR,
448 FORMAT_STATE_PTR,
449 FORMAT_STATE_PERCENT_CHAR,
450 FORMAT_STATE_INVALID,
451 };
452
453 struct printf_spec {
454 unsigned char flags; /* flags to number() */
455 unsigned char base; /* number base, 8, 10 or 16 only */
456 short precision; /* # of digits/chars */
457 int field_width; /* width of output field */
458 } __packed;
459 static_assert(sizeof(struct printf_spec) == 8);
460
461 #define FIELD_WIDTH_MAX ((1 << 23) - 1)
462 #define PRECISION_MAX ((1 << 15) - 1)
463
464 static noinline_for_stack
number(char * buf,char * end,unsigned long long num,struct printf_spec spec)465 char *number(char *buf, char *end, unsigned long long num,
466 struct printf_spec spec)
467 {
468 /* put_dec requires 2-byte alignment of the buffer. */
469 char tmp[3 * sizeof(num)] __aligned(2);
470 char sign;
471 char locase;
472 int need_pfx = ((spec.flags & SPECIAL) && spec.base != 10);
473 int i;
474 bool is_zero = num == 0LL;
475 int field_width = spec.field_width;
476 int precision = spec.precision;
477
478 /* locase = 0 or 0x20. ORing digits or letters with 'locase'
479 * produces same digits or (maybe lowercased) letters */
480 locase = (spec.flags & SMALL);
481 if (spec.flags & LEFT)
482 spec.flags &= ~ZEROPAD;
483 sign = 0;
484 if (spec.flags & SIGN) {
485 if ((signed long long)num < 0) {
486 sign = '-';
487 num = -(signed long long)num;
488 field_width--;
489 } else if (spec.flags & PLUS) {
490 sign = '+';
491 field_width--;
492 } else if (spec.flags & SPACE) {
493 sign = ' ';
494 field_width--;
495 }
496 }
497 if (need_pfx) {
498 if (spec.base == 16)
499 field_width -= 2;
500 else if (!is_zero)
501 field_width--;
502 }
503
504 /* generate full string in tmp[], in reverse order */
505 i = 0;
506 if (num < spec.base)
507 tmp[i++] = hex_asc_upper[num] | locase;
508 else if (spec.base != 10) { /* 8 or 16 */
509 int mask = spec.base - 1;
510 int shift = 3;
511
512 if (spec.base == 16)
513 shift = 4;
514 do {
515 tmp[i++] = (hex_asc_upper[((unsigned char)num) & mask] | locase);
516 num >>= shift;
517 } while (num);
518 } else { /* base 10 */
519 i = put_dec(tmp, num) - tmp;
520 }
521
522 /* printing 100 using %2d gives "100", not "00" */
523 if (i > precision)
524 precision = i;
525 /* leading space padding */
526 field_width -= precision;
527 if (!(spec.flags & (ZEROPAD | LEFT))) {
528 while (--field_width >= 0) {
529 if (buf < end)
530 *buf = ' ';
531 ++buf;
532 }
533 }
534 /* sign */
535 if (sign) {
536 if (buf < end)
537 *buf = sign;
538 ++buf;
539 }
540 /* "0x" / "0" prefix */
541 if (need_pfx) {
542 if (spec.base == 16 || !is_zero) {
543 if (buf < end)
544 *buf = '0';
545 ++buf;
546 }
547 if (spec.base == 16) {
548 if (buf < end)
549 *buf = ('X' | locase);
550 ++buf;
551 }
552 }
553 /* zero or space padding */
554 if (!(spec.flags & LEFT)) {
555 char c = ' ' + (spec.flags & ZEROPAD);
556
557 while (--field_width >= 0) {
558 if (buf < end)
559 *buf = c;
560 ++buf;
561 }
562 }
563 /* hmm even more zero padding? */
564 while (i <= --precision) {
565 if (buf < end)
566 *buf = '0';
567 ++buf;
568 }
569 /* actual digits of result */
570 while (--i >= 0) {
571 if (buf < end)
572 *buf = tmp[i];
573 ++buf;
574 }
575 /* trailing space padding */
576 while (--field_width >= 0) {
577 if (buf < end)
578 *buf = ' ';
579 ++buf;
580 }
581
582 return buf;
583 }
584
585 static noinline_for_stack
special_hex_number(char * buf,char * end,unsigned long long num,int size)586 char *special_hex_number(char *buf, char *end, unsigned long long num, int size)
587 {
588 struct printf_spec spec;
589
590 spec.field_width = 2 + 2 * size; /* 0x + hex */
591 spec.flags = SPECIAL | SMALL | ZEROPAD;
592 spec.base = 16;
593 spec.precision = -1;
594
595 return number(buf, end, num, spec);
596 }
597
move_right(char * buf,char * end,unsigned len,unsigned spaces)598 static void move_right(char *buf, char *end, unsigned len, unsigned spaces)
599 {
600 size_t size;
601 if (buf >= end) /* nowhere to put anything */
602 return;
603 size = end - buf;
604 if (size <= spaces) {
605 memset(buf, ' ', size);
606 return;
607 }
608 if (len) {
609 if (len > size - spaces)
610 len = size - spaces;
611 memmove(buf + spaces, buf, len);
612 }
613 memset(buf, ' ', spaces);
614 }
615
616 /*
617 * Handle field width padding for a string.
618 * @buf: current buffer position
619 * @n: length of string
620 * @end: end of output buffer
621 * @spec: for field width and flags
622 * Returns: new buffer position after padding.
623 */
624 static noinline_for_stack
widen_string(char * buf,int n,char * end,struct printf_spec spec)625 char *widen_string(char *buf, int n, char *end, struct printf_spec spec)
626 {
627 unsigned spaces;
628
629 if (likely(n >= spec.field_width))
630 return buf;
631 /* we want to pad the sucker */
632 spaces = spec.field_width - n;
633 if (!(spec.flags & LEFT)) {
634 move_right(buf - n, end, n, spaces);
635 return buf + spaces;
636 }
637 while (spaces--) {
638 if (buf < end)
639 *buf = ' ';
640 ++buf;
641 }
642 return buf;
643 }
644
645 /* Handle string from a well known address. */
string_nocheck(char * buf,char * end,const char * s,struct printf_spec spec)646 static char *string_nocheck(char *buf, char *end, const char *s,
647 struct printf_spec spec)
648 {
649 int len = 0;
650 int lim = spec.precision;
651
652 while (lim--) {
653 char c = *s++;
654 if (!c)
655 break;
656 if (buf < end)
657 *buf = c;
658 ++buf;
659 ++len;
660 }
661 return widen_string(buf, len, end, spec);
662 }
663
err_ptr(char * buf,char * end,void * ptr,struct printf_spec spec)664 static char *err_ptr(char *buf, char *end, void *ptr,
665 struct printf_spec spec)
666 {
667 int err = PTR_ERR(ptr);
668 const char *sym = errname(err);
669
670 if (sym)
671 return string_nocheck(buf, end, sym, spec);
672
673 /*
674 * Somebody passed ERR_PTR(-1234) or some other non-existing
675 * Efoo - or perhaps CONFIG_SYMBOLIC_ERRNAME=n. Fall back to
676 * printing it as its decimal representation.
677 */
678 spec.flags |= SIGN;
679 spec.base = 10;
680 return number(buf, end, err, spec);
681 }
682
683 /* Be careful: error messages must fit into the given buffer. */
error_string(char * buf,char * end,const char * s,struct printf_spec spec)684 static char *error_string(char *buf, char *end, const char *s,
685 struct printf_spec spec)
686 {
687 /*
688 * Hard limit to avoid a completely insane messages. It actually
689 * works pretty well because most error messages are in
690 * the many pointer format modifiers.
691 */
692 if (spec.precision == -1)
693 spec.precision = 2 * sizeof(void *);
694
695 return string_nocheck(buf, end, s, spec);
696 }
697
698 /*
699 * Do not call any complex external code here. Nested printk()/vsprintf()
700 * might cause infinite loops. Failures might break printk() and would
701 * be hard to debug.
702 */
check_pointer_msg(const void * ptr)703 static const char *check_pointer_msg(const void *ptr)
704 {
705 if (!ptr)
706 return "(null)";
707
708 if ((unsigned long)ptr < PAGE_SIZE || IS_ERR_VALUE(ptr))
709 return "(efault)";
710
711 return NULL;
712 }
713
check_pointer(char ** buf,char * end,const void * ptr,struct printf_spec spec)714 static int check_pointer(char **buf, char *end, const void *ptr,
715 struct printf_spec spec)
716 {
717 const char *err_msg;
718
719 err_msg = check_pointer_msg(ptr);
720 if (err_msg) {
721 *buf = error_string(*buf, end, err_msg, spec);
722 return -EFAULT;
723 }
724
725 return 0;
726 }
727
728 static noinline_for_stack
string(char * buf,char * end,const char * s,struct printf_spec spec)729 char *string(char *buf, char *end, const char *s,
730 struct printf_spec spec)
731 {
732 if (check_pointer(&buf, end, s, spec))
733 return buf;
734
735 return string_nocheck(buf, end, s, spec);
736 }
737
pointer_string(char * buf,char * end,const void * ptr,struct printf_spec spec)738 static char *pointer_string(char *buf, char *end,
739 const void *ptr,
740 struct printf_spec spec)
741 {
742 spec.base = 16;
743 spec.flags |= SMALL;
744 if (spec.field_width == -1) {
745 spec.field_width = 2 * sizeof(ptr);
746 spec.flags |= ZEROPAD;
747 }
748
749 return number(buf, end, (unsigned long int)ptr, spec);
750 }
751
752 /* Make pointers available for printing early in the boot sequence. */
753 static int debug_boot_weak_hash __ro_after_init;
754
debug_boot_weak_hash_enable(char * str)755 static int __init debug_boot_weak_hash_enable(char *str)
756 {
757 debug_boot_weak_hash = 1;
758 pr_info("debug_boot_weak_hash enabled\n");
759 return 0;
760 }
761 early_param("debug_boot_weak_hash", debug_boot_weak_hash_enable);
762
763 static bool filled_random_ptr_key __read_mostly;
764 static siphash_key_t ptr_key __read_mostly;
765
fill_ptr_key(struct notifier_block * nb,unsigned long action,void * data)766 static int fill_ptr_key(struct notifier_block *nb, unsigned long action, void *data)
767 {
768 get_random_bytes(&ptr_key, sizeof(ptr_key));
769
770 /* Pairs with smp_rmb() before reading ptr_key. */
771 smp_wmb();
772 WRITE_ONCE(filled_random_ptr_key, true);
773 return NOTIFY_DONE;
774 }
775
vsprintf_init_hashval(void)776 static int __init vsprintf_init_hashval(void)
777 {
778 static struct notifier_block fill_ptr_key_nb = { .notifier_call = fill_ptr_key };
779 execute_with_initialized_rng(&fill_ptr_key_nb);
780 return 0;
781 }
subsys_initcall(vsprintf_init_hashval)782 subsys_initcall(vsprintf_init_hashval)
783
784 /* Maps a pointer to a 32 bit unique identifier. */
785 static inline int __ptr_to_hashval(const void *ptr, unsigned long *hashval_out)
786 {
787 unsigned long hashval;
788
789 if (!READ_ONCE(filled_random_ptr_key))
790 return -EBUSY;
791
792 /* Pairs with smp_wmb() after writing ptr_key. */
793 smp_rmb();
794
795 #ifdef CONFIG_64BIT
796 hashval = (unsigned long)siphash_1u64((u64)ptr, &ptr_key);
797 /*
798 * Mask off the first 32 bits, this makes explicit that we have
799 * modified the address (and 32 bits is plenty for a unique ID).
800 */
801 hashval = hashval & 0xffffffff;
802 #else
803 hashval = (unsigned long)siphash_1u32((u32)ptr, &ptr_key);
804 #endif
805 *hashval_out = hashval;
806 return 0;
807 }
808
ptr_to_hashval(const void * ptr,unsigned long * hashval_out)809 int ptr_to_hashval(const void *ptr, unsigned long *hashval_out)
810 {
811 return __ptr_to_hashval(ptr, hashval_out);
812 }
813
ptr_to_id(char * buf,char * end,const void * ptr,struct printf_spec spec)814 static char *ptr_to_id(char *buf, char *end, const void *ptr,
815 struct printf_spec spec)
816 {
817 const char *str = sizeof(ptr) == 8 ? "(____ptrval____)" : "(ptrval)";
818 unsigned long hashval;
819 int ret;
820
821 /*
822 * Print the real pointer value for NULL and error pointers,
823 * as they are not actual addresses.
824 */
825 if (IS_ERR_OR_NULL(ptr))
826 return pointer_string(buf, end, ptr, spec);
827
828 /* When debugging early boot use non-cryptographically secure hash. */
829 if (unlikely(debug_boot_weak_hash)) {
830 hashval = hash_long((unsigned long)ptr, 32);
831 return pointer_string(buf, end, (const void *)hashval, spec);
832 }
833
834 ret = __ptr_to_hashval(ptr, &hashval);
835 if (ret) {
836 spec.field_width = 2 * sizeof(ptr);
837 /* string length must be less than default_width */
838 return error_string(buf, end, str, spec);
839 }
840
841 return pointer_string(buf, end, (const void *)hashval, spec);
842 }
843
default_pointer(char * buf,char * end,const void * ptr,struct printf_spec spec)844 static char *default_pointer(char *buf, char *end, const void *ptr,
845 struct printf_spec spec)
846 {
847 /*
848 * default is to _not_ leak addresses, so hash before printing,
849 * unless no_hash_pointers is specified on the command line.
850 */
851 if (unlikely(no_hash_pointers))
852 return pointer_string(buf, end, ptr, spec);
853
854 return ptr_to_id(buf, end, ptr, spec);
855 }
856
857 int kptr_restrict __read_mostly;
858
859 static noinline_for_stack
restricted_pointer(char * buf,char * end,const void * ptr,struct printf_spec spec)860 char *restricted_pointer(char *buf, char *end, const void *ptr,
861 struct printf_spec spec)
862 {
863 switch (kptr_restrict) {
864 case 0:
865 /* Handle as %p, hash and do _not_ leak addresses. */
866 return default_pointer(buf, end, ptr, spec);
867 case 1: {
868 const struct cred *cred;
869
870 /*
871 * kptr_restrict==1 cannot be used in IRQ context
872 * because its test for CAP_SYSLOG would be meaningless.
873 */
874 if (in_hardirq() || in_serving_softirq() || in_nmi()) {
875 if (spec.field_width == -1)
876 spec.field_width = 2 * sizeof(ptr);
877 return error_string(buf, end, "pK-error", spec);
878 }
879
880 /*
881 * Only print the real pointer value if the current
882 * process has CAP_SYSLOG and is running with the
883 * same credentials it started with. This is because
884 * access to files is checked at open() time, but %pK
885 * checks permission at read() time. We don't want to
886 * leak pointer values if a binary opens a file using
887 * %pK and then elevates privileges before reading it.
888 */
889 cred = current_cred();
890 if (!has_capability_noaudit(current, CAP_SYSLOG) ||
891 !uid_eq(cred->euid, cred->uid) ||
892 !gid_eq(cred->egid, cred->gid))
893 ptr = NULL;
894 break;
895 }
896 case 2:
897 default:
898 /* Always print 0's for %pK */
899 ptr = NULL;
900 break;
901 }
902
903 return pointer_string(buf, end, ptr, spec);
904 }
905
906 static noinline_for_stack
dentry_name(char * buf,char * end,const struct dentry * d,struct printf_spec spec,const char * fmt)907 char *dentry_name(char *buf, char *end, const struct dentry *d, struct printf_spec spec,
908 const char *fmt)
909 {
910 const char *array[4], *s;
911 const struct dentry *p;
912 int depth;
913 int i, n;
914
915 switch (fmt[1]) {
916 case '2': case '3': case '4':
917 depth = fmt[1] - '0';
918 break;
919 default:
920 depth = 1;
921 }
922
923 rcu_read_lock();
924 for (i = 0; i < depth; i++, d = p) {
925 if (check_pointer(&buf, end, d, spec)) {
926 rcu_read_unlock();
927 return buf;
928 }
929
930 p = READ_ONCE(d->d_parent);
931 array[i] = READ_ONCE(d->d_name.name);
932 if (p == d) {
933 if (i)
934 array[i] = "";
935 i++;
936 break;
937 }
938 }
939 s = array[--i];
940 for (n = 0; n != spec.precision; n++, buf++) {
941 char c = *s++;
942 if (!c) {
943 if (!i)
944 break;
945 c = '/';
946 s = array[--i];
947 }
948 if (buf < end)
949 *buf = c;
950 }
951 rcu_read_unlock();
952 return widen_string(buf, n, end, spec);
953 }
954
955 static noinline_for_stack
file_dentry_name(char * buf,char * end,const struct file * f,struct printf_spec spec,const char * fmt)956 char *file_dentry_name(char *buf, char *end, const struct file *f,
957 struct printf_spec spec, const char *fmt)
958 {
959 if (check_pointer(&buf, end, f, spec))
960 return buf;
961
962 return dentry_name(buf, end, f->f_path.dentry, spec, fmt);
963 }
964 #ifdef CONFIG_BLOCK
965 static noinline_for_stack
bdev_name(char * buf,char * end,struct block_device * bdev,struct printf_spec spec,const char * fmt)966 char *bdev_name(char *buf, char *end, struct block_device *bdev,
967 struct printf_spec spec, const char *fmt)
968 {
969 struct gendisk *hd;
970
971 if (check_pointer(&buf, end, bdev, spec))
972 return buf;
973
974 hd = bdev->bd_disk;
975 buf = string(buf, end, hd->disk_name, spec);
976 if (bdev_is_partition(bdev)) {
977 if (isdigit(hd->disk_name[strlen(hd->disk_name)-1])) {
978 if (buf < end)
979 *buf = 'p';
980 buf++;
981 }
982 buf = number(buf, end, bdev_partno(bdev), spec);
983 }
984 return buf;
985 }
986 #endif
987
988 static noinline_for_stack
symbol_string(char * buf,char * end,void * ptr,struct printf_spec spec,const char * fmt)989 char *symbol_string(char *buf, char *end, void *ptr,
990 struct printf_spec spec, const char *fmt)
991 {
992 unsigned long value;
993 #ifdef CONFIG_KALLSYMS
994 char sym[KSYM_SYMBOL_LEN];
995 #endif
996
997 if (fmt[1] == 'R')
998 ptr = __builtin_extract_return_addr(ptr);
999 value = (unsigned long)ptr;
1000
1001 #ifdef CONFIG_KALLSYMS
1002 if (*fmt == 'B' && fmt[1] == 'b')
1003 sprint_backtrace_build_id(sym, value);
1004 else if (*fmt == 'B')
1005 sprint_backtrace(sym, value);
1006 else if (*fmt == 'S' && (fmt[1] == 'b' || (fmt[1] == 'R' && fmt[2] == 'b')))
1007 sprint_symbol_build_id(sym, value);
1008 else if (*fmt != 's')
1009 sprint_symbol(sym, value);
1010 else
1011 sprint_symbol_no_offset(sym, value);
1012
1013 return string_nocheck(buf, end, sym, spec);
1014 #else
1015 return special_hex_number(buf, end, value, sizeof(void *));
1016 #endif
1017 }
1018
1019 static const struct printf_spec default_str_spec = {
1020 .field_width = -1,
1021 .precision = -1,
1022 };
1023
1024 static const struct printf_spec default_flag_spec = {
1025 .base = 16,
1026 .precision = -1,
1027 .flags = SPECIAL | SMALL,
1028 };
1029
1030 static const struct printf_spec default_dec_spec = {
1031 .base = 10,
1032 .precision = -1,
1033 };
1034
1035 static const struct printf_spec default_dec02_spec = {
1036 .base = 10,
1037 .field_width = 2,
1038 .precision = -1,
1039 .flags = ZEROPAD,
1040 };
1041
1042 static const struct printf_spec default_dec04_spec = {
1043 .base = 10,
1044 .field_width = 4,
1045 .precision = -1,
1046 .flags = ZEROPAD,
1047 };
1048
1049 static noinline_for_stack
hex_range(char * buf,char * end,u64 start_val,u64 end_val,struct printf_spec spec)1050 char *hex_range(char *buf, char *end, u64 start_val, u64 end_val,
1051 struct printf_spec spec)
1052 {
1053 buf = number(buf, end, start_val, spec);
1054 if (start_val == end_val)
1055 return buf;
1056
1057 if (buf < end)
1058 *buf = '-';
1059 ++buf;
1060 return number(buf, end, end_val, spec);
1061 }
1062
1063 static noinline_for_stack
resource_string(char * buf,char * end,struct resource * res,struct printf_spec spec,const char * fmt)1064 char *resource_string(char *buf, char *end, struct resource *res,
1065 struct printf_spec spec, const char *fmt)
1066 {
1067 #ifndef IO_RSRC_PRINTK_SIZE
1068 #define IO_RSRC_PRINTK_SIZE 6
1069 #endif
1070
1071 #ifndef MEM_RSRC_PRINTK_SIZE
1072 #define MEM_RSRC_PRINTK_SIZE 10
1073 #endif
1074 static const struct printf_spec io_spec = {
1075 .base = 16,
1076 .field_width = IO_RSRC_PRINTK_SIZE,
1077 .precision = -1,
1078 .flags = SPECIAL | SMALL | ZEROPAD,
1079 };
1080 static const struct printf_spec mem_spec = {
1081 .base = 16,
1082 .field_width = MEM_RSRC_PRINTK_SIZE,
1083 .precision = -1,
1084 .flags = SPECIAL | SMALL | ZEROPAD,
1085 };
1086 static const struct printf_spec bus_spec = {
1087 .base = 16,
1088 .field_width = 2,
1089 .precision = -1,
1090 .flags = SMALL | ZEROPAD,
1091 };
1092 static const struct printf_spec str_spec = {
1093 .field_width = -1,
1094 .precision = 10,
1095 .flags = LEFT,
1096 };
1097
1098 /* 32-bit res (sizeof==4): 10 chars in dec, 10 in hex ("0x" + 8)
1099 * 64-bit res (sizeof==8): 20 chars in dec, 18 in hex ("0x" + 16) */
1100 #define RSRC_BUF_SIZE ((2 * sizeof(resource_size_t)) + 4)
1101 #define FLAG_BUF_SIZE (2 * sizeof(res->flags))
1102 #define DECODED_BUF_SIZE sizeof("[mem - 64bit pref window disabled]")
1103 #define RAW_BUF_SIZE sizeof("[mem - flags 0x]")
1104 char sym[MAX(2*RSRC_BUF_SIZE + DECODED_BUF_SIZE,
1105 2*RSRC_BUF_SIZE + FLAG_BUF_SIZE + RAW_BUF_SIZE)];
1106
1107 char *p = sym, *pend = sym + sizeof(sym);
1108 int decode = (fmt[0] == 'R') ? 1 : 0;
1109 const struct printf_spec *specp;
1110
1111 if (check_pointer(&buf, end, res, spec))
1112 return buf;
1113
1114 *p++ = '[';
1115 if (res->flags & IORESOURCE_IO) {
1116 p = string_nocheck(p, pend, "io ", str_spec);
1117 specp = &io_spec;
1118 } else if (res->flags & IORESOURCE_MEM) {
1119 p = string_nocheck(p, pend, "mem ", str_spec);
1120 specp = &mem_spec;
1121 } else if (res->flags & IORESOURCE_IRQ) {
1122 p = string_nocheck(p, pend, "irq ", str_spec);
1123 specp = &default_dec_spec;
1124 } else if (res->flags & IORESOURCE_DMA) {
1125 p = string_nocheck(p, pend, "dma ", str_spec);
1126 specp = &default_dec_spec;
1127 } else if (res->flags & IORESOURCE_BUS) {
1128 p = string_nocheck(p, pend, "bus ", str_spec);
1129 specp = &bus_spec;
1130 } else {
1131 p = string_nocheck(p, pend, "??? ", str_spec);
1132 specp = &mem_spec;
1133 decode = 0;
1134 }
1135 if (decode && res->flags & IORESOURCE_UNSET) {
1136 p = string_nocheck(p, pend, "size ", str_spec);
1137 p = number(p, pend, resource_size(res), *specp);
1138 } else {
1139 p = hex_range(p, pend, res->start, res->end, *specp);
1140 }
1141 if (decode) {
1142 if (res->flags & IORESOURCE_MEM_64)
1143 p = string_nocheck(p, pend, " 64bit", str_spec);
1144 if (res->flags & IORESOURCE_PREFETCH)
1145 p = string_nocheck(p, pend, " pref", str_spec);
1146 if (res->flags & IORESOURCE_WINDOW)
1147 p = string_nocheck(p, pend, " window", str_spec);
1148 if (res->flags & IORESOURCE_DISABLED)
1149 p = string_nocheck(p, pend, " disabled", str_spec);
1150 } else {
1151 p = string_nocheck(p, pend, " flags ", str_spec);
1152 p = number(p, pend, res->flags, default_flag_spec);
1153 }
1154 *p++ = ']';
1155 *p = '\0';
1156
1157 return string_nocheck(buf, end, sym, spec);
1158 }
1159
1160 static noinline_for_stack
range_string(char * buf,char * end,const struct range * range,struct printf_spec spec,const char * fmt)1161 char *range_string(char *buf, char *end, const struct range *range,
1162 struct printf_spec spec, const char *fmt)
1163 {
1164 char sym[sizeof("[range 0x0123456789abcdef-0x0123456789abcdef]")];
1165 char *p = sym, *pend = sym + sizeof(sym);
1166
1167 struct printf_spec range_spec = {
1168 .field_width = 2 + 2 * sizeof(range->start), /* 0x + 2 * 8 */
1169 .flags = SPECIAL | SMALL | ZEROPAD,
1170 .base = 16,
1171 .precision = -1,
1172 };
1173
1174 if (check_pointer(&buf, end, range, spec))
1175 return buf;
1176
1177 p = string_nocheck(p, pend, "[range ", default_str_spec);
1178 p = hex_range(p, pend, range->start, range->end, range_spec);
1179 *p++ = ']';
1180 *p = '\0';
1181
1182 return string_nocheck(buf, end, sym, spec);
1183 }
1184
1185 static noinline_for_stack
hex_string(char * buf,char * end,u8 * addr,struct printf_spec spec,const char * fmt)1186 char *hex_string(char *buf, char *end, u8 *addr, struct printf_spec spec,
1187 const char *fmt)
1188 {
1189 int i, len = 1; /* if we pass '%ph[CDN]', field width remains
1190 negative value, fallback to the default */
1191 char separator;
1192
1193 if (spec.field_width == 0)
1194 /* nothing to print */
1195 return buf;
1196
1197 if (check_pointer(&buf, end, addr, spec))
1198 return buf;
1199
1200 switch (fmt[1]) {
1201 case 'C':
1202 separator = ':';
1203 break;
1204 case 'D':
1205 separator = '-';
1206 break;
1207 case 'N':
1208 separator = 0;
1209 break;
1210 default:
1211 separator = ' ';
1212 break;
1213 }
1214
1215 if (spec.field_width > 0)
1216 len = min_t(int, spec.field_width, 64);
1217
1218 for (i = 0; i < len; ++i) {
1219 if (buf < end)
1220 *buf = hex_asc_hi(addr[i]);
1221 ++buf;
1222 if (buf < end)
1223 *buf = hex_asc_lo(addr[i]);
1224 ++buf;
1225
1226 if (separator && i != len - 1) {
1227 if (buf < end)
1228 *buf = separator;
1229 ++buf;
1230 }
1231 }
1232
1233 return buf;
1234 }
1235
1236 static noinline_for_stack
bitmap_string(char * buf,char * end,const unsigned long * bitmap,struct printf_spec spec,const char * fmt)1237 char *bitmap_string(char *buf, char *end, const unsigned long *bitmap,
1238 struct printf_spec spec, const char *fmt)
1239 {
1240 const int CHUNKSZ = 32;
1241 int nr_bits = max_t(int, spec.field_width, 0);
1242 int i, chunksz;
1243 bool first = true;
1244
1245 if (check_pointer(&buf, end, bitmap, spec))
1246 return buf;
1247
1248 /* reused to print numbers */
1249 spec = (struct printf_spec){ .flags = SMALL | ZEROPAD, .base = 16 };
1250
1251 chunksz = nr_bits & (CHUNKSZ - 1);
1252 if (chunksz == 0)
1253 chunksz = CHUNKSZ;
1254
1255 i = ALIGN(nr_bits, CHUNKSZ) - CHUNKSZ;
1256 for (; i >= 0; i -= CHUNKSZ) {
1257 u32 chunkmask, val;
1258 int word, bit;
1259
1260 chunkmask = ((1ULL << chunksz) - 1);
1261 word = i / BITS_PER_LONG;
1262 bit = i % BITS_PER_LONG;
1263 val = (bitmap[word] >> bit) & chunkmask;
1264
1265 if (!first) {
1266 if (buf < end)
1267 *buf = ',';
1268 buf++;
1269 }
1270 first = false;
1271
1272 spec.field_width = DIV_ROUND_UP(chunksz, 4);
1273 buf = number(buf, end, val, spec);
1274
1275 chunksz = CHUNKSZ;
1276 }
1277 return buf;
1278 }
1279
1280 static noinline_for_stack
bitmap_list_string(char * buf,char * end,const unsigned long * bitmap,struct printf_spec spec,const char * fmt)1281 char *bitmap_list_string(char *buf, char *end, const unsigned long *bitmap,
1282 struct printf_spec spec, const char *fmt)
1283 {
1284 int nr_bits = max_t(int, spec.field_width, 0);
1285 bool first = true;
1286 int rbot, rtop;
1287
1288 if (check_pointer(&buf, end, bitmap, spec))
1289 return buf;
1290
1291 for_each_set_bitrange(rbot, rtop, bitmap, nr_bits) {
1292 if (!first) {
1293 if (buf < end)
1294 *buf = ',';
1295 buf++;
1296 }
1297 first = false;
1298
1299 buf = number(buf, end, rbot, default_dec_spec);
1300 if (rtop == rbot + 1)
1301 continue;
1302
1303 if (buf < end)
1304 *buf = '-';
1305 buf = number(++buf, end, rtop - 1, default_dec_spec);
1306 }
1307 return buf;
1308 }
1309
1310 static noinline_for_stack
mac_address_string(char * buf,char * end,u8 * addr,struct printf_spec spec,const char * fmt)1311 char *mac_address_string(char *buf, char *end, u8 *addr,
1312 struct printf_spec spec, const char *fmt)
1313 {
1314 char mac_addr[sizeof("xx:xx:xx:xx:xx:xx")];
1315 char *p = mac_addr;
1316 int i;
1317 char separator;
1318 bool reversed = false;
1319
1320 if (check_pointer(&buf, end, addr, spec))
1321 return buf;
1322
1323 switch (fmt[1]) {
1324 case 'F':
1325 separator = '-';
1326 break;
1327
1328 case 'R':
1329 reversed = true;
1330 fallthrough;
1331
1332 default:
1333 separator = ':';
1334 break;
1335 }
1336
1337 for (i = 0; i < 6; i++) {
1338 if (reversed)
1339 p = hex_byte_pack(p, addr[5 - i]);
1340 else
1341 p = hex_byte_pack(p, addr[i]);
1342
1343 if (fmt[0] == 'M' && i != 5)
1344 *p++ = separator;
1345 }
1346 *p = '\0';
1347
1348 return string_nocheck(buf, end, mac_addr, spec);
1349 }
1350
1351 static noinline_for_stack
ip4_string(char * p,const u8 * addr,const char * fmt)1352 char *ip4_string(char *p, const u8 *addr, const char *fmt)
1353 {
1354 int i;
1355 bool leading_zeros = (fmt[0] == 'i');
1356 int index;
1357 int step;
1358
1359 switch (fmt[2]) {
1360 case 'h':
1361 #ifdef __BIG_ENDIAN
1362 index = 0;
1363 step = 1;
1364 #else
1365 index = 3;
1366 step = -1;
1367 #endif
1368 break;
1369 case 'l':
1370 index = 3;
1371 step = -1;
1372 break;
1373 case 'n':
1374 case 'b':
1375 default:
1376 index = 0;
1377 step = 1;
1378 break;
1379 }
1380 for (i = 0; i < 4; i++) {
1381 char temp[4] __aligned(2); /* hold each IP quad in reverse order */
1382 int digits = put_dec_trunc8(temp, addr[index]) - temp;
1383 if (leading_zeros) {
1384 if (digits < 3)
1385 *p++ = '0';
1386 if (digits < 2)
1387 *p++ = '0';
1388 }
1389 /* reverse the digits in the quad */
1390 while (digits--)
1391 *p++ = temp[digits];
1392 if (i < 3)
1393 *p++ = '.';
1394 index += step;
1395 }
1396 *p = '\0';
1397
1398 return p;
1399 }
1400
1401 static noinline_for_stack
ip6_compressed_string(char * p,const char * addr)1402 char *ip6_compressed_string(char *p, const char *addr)
1403 {
1404 int i, j, range;
1405 unsigned char zerolength[8];
1406 int longest = 1;
1407 int colonpos = -1;
1408 u16 word;
1409 u8 hi, lo;
1410 bool needcolon = false;
1411 bool useIPv4;
1412 struct in6_addr in6;
1413
1414 memcpy(&in6, addr, sizeof(struct in6_addr));
1415
1416 useIPv4 = ipv6_addr_v4mapped(&in6) || ipv6_addr_is_isatap(&in6);
1417
1418 memset(zerolength, 0, sizeof(zerolength));
1419
1420 if (useIPv4)
1421 range = 6;
1422 else
1423 range = 8;
1424
1425 /* find position of longest 0 run */
1426 for (i = 0; i < range; i++) {
1427 for (j = i; j < range; j++) {
1428 if (in6.s6_addr16[j] != 0)
1429 break;
1430 zerolength[i]++;
1431 }
1432 }
1433 for (i = 0; i < range; i++) {
1434 if (zerolength[i] > longest) {
1435 longest = zerolength[i];
1436 colonpos = i;
1437 }
1438 }
1439 if (longest == 1) /* don't compress a single 0 */
1440 colonpos = -1;
1441
1442 /* emit address */
1443 for (i = 0; i < range; i++) {
1444 if (i == colonpos) {
1445 if (needcolon || i == 0)
1446 *p++ = ':';
1447 *p++ = ':';
1448 needcolon = false;
1449 i += longest - 1;
1450 continue;
1451 }
1452 if (needcolon) {
1453 *p++ = ':';
1454 needcolon = false;
1455 }
1456 /* hex u16 without leading 0s */
1457 word = ntohs(in6.s6_addr16[i]);
1458 hi = word >> 8;
1459 lo = word & 0xff;
1460 if (hi) {
1461 if (hi > 0x0f)
1462 p = hex_byte_pack(p, hi);
1463 else
1464 *p++ = hex_asc_lo(hi);
1465 p = hex_byte_pack(p, lo);
1466 }
1467 else if (lo > 0x0f)
1468 p = hex_byte_pack(p, lo);
1469 else
1470 *p++ = hex_asc_lo(lo);
1471 needcolon = true;
1472 }
1473
1474 if (useIPv4) {
1475 if (needcolon)
1476 *p++ = ':';
1477 p = ip4_string(p, &in6.s6_addr[12], "I4");
1478 }
1479 *p = '\0';
1480
1481 return p;
1482 }
1483
1484 static noinline_for_stack
ip6_string(char * p,const char * addr,const char * fmt)1485 char *ip6_string(char *p, const char *addr, const char *fmt)
1486 {
1487 int i;
1488
1489 for (i = 0; i < 8; i++) {
1490 p = hex_byte_pack(p, *addr++);
1491 p = hex_byte_pack(p, *addr++);
1492 if (fmt[0] == 'I' && i != 7)
1493 *p++ = ':';
1494 }
1495 *p = '\0';
1496
1497 return p;
1498 }
1499
1500 static noinline_for_stack
ip6_addr_string(char * buf,char * end,const u8 * addr,struct printf_spec spec,const char * fmt)1501 char *ip6_addr_string(char *buf, char *end, const u8 *addr,
1502 struct printf_spec spec, const char *fmt)
1503 {
1504 char ip6_addr[sizeof("xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255")];
1505
1506 if (fmt[0] == 'I' && fmt[2] == 'c')
1507 ip6_compressed_string(ip6_addr, addr);
1508 else
1509 ip6_string(ip6_addr, addr, fmt);
1510
1511 return string_nocheck(buf, end, ip6_addr, spec);
1512 }
1513
1514 static noinline_for_stack
ip4_addr_string(char * buf,char * end,const u8 * addr,struct printf_spec spec,const char * fmt)1515 char *ip4_addr_string(char *buf, char *end, const u8 *addr,
1516 struct printf_spec spec, const char *fmt)
1517 {
1518 char ip4_addr[sizeof("255.255.255.255")];
1519
1520 ip4_string(ip4_addr, addr, fmt);
1521
1522 return string_nocheck(buf, end, ip4_addr, spec);
1523 }
1524
1525 static noinline_for_stack
ip6_addr_string_sa(char * buf,char * end,const struct sockaddr_in6 * sa,struct printf_spec spec,const char * fmt)1526 char *ip6_addr_string_sa(char *buf, char *end, const struct sockaddr_in6 *sa,
1527 struct printf_spec spec, const char *fmt)
1528 {
1529 bool have_p = false, have_s = false, have_f = false, have_c = false;
1530 char ip6_addr[sizeof("[xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255]") +
1531 sizeof(":12345") + sizeof("/123456789") +
1532 sizeof("%1234567890")];
1533 char *p = ip6_addr, *pend = ip6_addr + sizeof(ip6_addr);
1534 const u8 *addr = (const u8 *) &sa->sin6_addr;
1535 char fmt6[2] = { fmt[0], '6' };
1536 u8 off = 0;
1537
1538 fmt++;
1539 while (isalpha(*++fmt)) {
1540 switch (*fmt) {
1541 case 'p':
1542 have_p = true;
1543 break;
1544 case 'f':
1545 have_f = true;
1546 break;
1547 case 's':
1548 have_s = true;
1549 break;
1550 case 'c':
1551 have_c = true;
1552 break;
1553 }
1554 }
1555
1556 if (have_p || have_s || have_f) {
1557 *p = '[';
1558 off = 1;
1559 }
1560
1561 if (fmt6[0] == 'I' && have_c)
1562 p = ip6_compressed_string(ip6_addr + off, addr);
1563 else
1564 p = ip6_string(ip6_addr + off, addr, fmt6);
1565
1566 if (have_p || have_s || have_f)
1567 *p++ = ']';
1568
1569 if (have_p) {
1570 *p++ = ':';
1571 p = number(p, pend, ntohs(sa->sin6_port), spec);
1572 }
1573 if (have_f) {
1574 *p++ = '/';
1575 p = number(p, pend, ntohl(sa->sin6_flowinfo &
1576 IPV6_FLOWINFO_MASK), spec);
1577 }
1578 if (have_s) {
1579 *p++ = '%';
1580 p = number(p, pend, sa->sin6_scope_id, spec);
1581 }
1582 *p = '\0';
1583
1584 return string_nocheck(buf, end, ip6_addr, spec);
1585 }
1586
1587 static noinline_for_stack
ip4_addr_string_sa(char * buf,char * end,const struct sockaddr_in * sa,struct printf_spec spec,const char * fmt)1588 char *ip4_addr_string_sa(char *buf, char *end, const struct sockaddr_in *sa,
1589 struct printf_spec spec, const char *fmt)
1590 {
1591 bool have_p = false;
1592 char *p, ip4_addr[sizeof("255.255.255.255") + sizeof(":12345")];
1593 char *pend = ip4_addr + sizeof(ip4_addr);
1594 const u8 *addr = (const u8 *) &sa->sin_addr.s_addr;
1595 char fmt4[3] = { fmt[0], '4', 0 };
1596
1597 fmt++;
1598 while (isalpha(*++fmt)) {
1599 switch (*fmt) {
1600 case 'p':
1601 have_p = true;
1602 break;
1603 case 'h':
1604 case 'l':
1605 case 'n':
1606 case 'b':
1607 fmt4[2] = *fmt;
1608 break;
1609 }
1610 }
1611
1612 p = ip4_string(ip4_addr, addr, fmt4);
1613 if (have_p) {
1614 *p++ = ':';
1615 p = number(p, pend, ntohs(sa->sin_port), spec);
1616 }
1617 *p = '\0';
1618
1619 return string_nocheck(buf, end, ip4_addr, spec);
1620 }
1621
1622 static noinline_for_stack
ip_addr_string(char * buf,char * end,const void * ptr,struct printf_spec spec,const char * fmt)1623 char *ip_addr_string(char *buf, char *end, const void *ptr,
1624 struct printf_spec spec, const char *fmt)
1625 {
1626 char *err_fmt_msg;
1627
1628 if (check_pointer(&buf, end, ptr, spec))
1629 return buf;
1630
1631 switch (fmt[1]) {
1632 case '6':
1633 return ip6_addr_string(buf, end, ptr, spec, fmt);
1634 case '4':
1635 return ip4_addr_string(buf, end, ptr, spec, fmt);
1636 case 'S': {
1637 const union {
1638 struct sockaddr raw;
1639 struct sockaddr_in v4;
1640 struct sockaddr_in6 v6;
1641 } *sa = ptr;
1642
1643 switch (sa->raw.sa_family) {
1644 case AF_INET:
1645 return ip4_addr_string_sa(buf, end, &sa->v4, spec, fmt);
1646 case AF_INET6:
1647 return ip6_addr_string_sa(buf, end, &sa->v6, spec, fmt);
1648 default:
1649 return error_string(buf, end, "(einval)", spec);
1650 }}
1651 }
1652
1653 err_fmt_msg = fmt[0] == 'i' ? "(%pi?)" : "(%pI?)";
1654 return error_string(buf, end, err_fmt_msg, spec);
1655 }
1656
1657 static noinline_for_stack
escaped_string(char * buf,char * end,u8 * addr,struct printf_spec spec,const char * fmt)1658 char *escaped_string(char *buf, char *end, u8 *addr, struct printf_spec spec,
1659 const char *fmt)
1660 {
1661 bool found = true;
1662 int count = 1;
1663 unsigned int flags = 0;
1664 int len;
1665
1666 if (spec.field_width == 0)
1667 return buf; /* nothing to print */
1668
1669 if (check_pointer(&buf, end, addr, spec))
1670 return buf;
1671
1672 do {
1673 switch (fmt[count++]) {
1674 case 'a':
1675 flags |= ESCAPE_ANY;
1676 break;
1677 case 'c':
1678 flags |= ESCAPE_SPECIAL;
1679 break;
1680 case 'h':
1681 flags |= ESCAPE_HEX;
1682 break;
1683 case 'n':
1684 flags |= ESCAPE_NULL;
1685 break;
1686 case 'o':
1687 flags |= ESCAPE_OCTAL;
1688 break;
1689 case 'p':
1690 flags |= ESCAPE_NP;
1691 break;
1692 case 's':
1693 flags |= ESCAPE_SPACE;
1694 break;
1695 default:
1696 found = false;
1697 break;
1698 }
1699 } while (found);
1700
1701 if (!flags)
1702 flags = ESCAPE_ANY_NP;
1703
1704 len = spec.field_width < 0 ? 1 : spec.field_width;
1705
1706 /*
1707 * string_escape_mem() writes as many characters as it can to
1708 * the given buffer, and returns the total size of the output
1709 * had the buffer been big enough.
1710 */
1711 buf += string_escape_mem(addr, len, buf, buf < end ? end - buf : 0, flags, NULL);
1712
1713 return buf;
1714 }
1715
1716 __diag_push();
1717 __diag_ignore(GCC, all, "-Wsuggest-attribute=format",
1718 "Not a valid __printf() conversion candidate.");
va_format(char * buf,char * end,struct va_format * va_fmt,struct printf_spec spec)1719 static char *va_format(char *buf, char *end, struct va_format *va_fmt,
1720 struct printf_spec spec)
1721 {
1722 va_list va;
1723
1724 if (check_pointer(&buf, end, va_fmt, spec))
1725 return buf;
1726
1727 va_copy(va, *va_fmt->va);
1728 buf += vsnprintf(buf, end > buf ? end - buf : 0, va_fmt->fmt, va);
1729 va_end(va);
1730
1731 return buf;
1732 }
1733 __diag_pop();
1734
1735 static noinline_for_stack
uuid_string(char * buf,char * end,const u8 * addr,struct printf_spec spec,const char * fmt)1736 char *uuid_string(char *buf, char *end, const u8 *addr,
1737 struct printf_spec spec, const char *fmt)
1738 {
1739 char uuid[UUID_STRING_LEN + 1];
1740 char *p = uuid;
1741 int i;
1742 const u8 *index = uuid_index;
1743 bool uc = false;
1744
1745 if (check_pointer(&buf, end, addr, spec))
1746 return buf;
1747
1748 switch (*(++fmt)) {
1749 case 'L':
1750 uc = true;
1751 fallthrough;
1752 case 'l':
1753 index = guid_index;
1754 break;
1755 case 'B':
1756 uc = true;
1757 break;
1758 }
1759
1760 for (i = 0; i < 16; i++) {
1761 if (uc)
1762 p = hex_byte_pack_upper(p, addr[index[i]]);
1763 else
1764 p = hex_byte_pack(p, addr[index[i]]);
1765 switch (i) {
1766 case 3:
1767 case 5:
1768 case 7:
1769 case 9:
1770 *p++ = '-';
1771 break;
1772 }
1773 }
1774
1775 *p = 0;
1776
1777 return string_nocheck(buf, end, uuid, spec);
1778 }
1779
1780 static noinline_for_stack
netdev_bits(char * buf,char * end,const void * addr,struct printf_spec spec,const char * fmt)1781 char *netdev_bits(char *buf, char *end, const void *addr,
1782 struct printf_spec spec, const char *fmt)
1783 {
1784 unsigned long long num;
1785 int size;
1786
1787 if (check_pointer(&buf, end, addr, spec))
1788 return buf;
1789
1790 switch (fmt[1]) {
1791 case 'F':
1792 num = *(const netdev_features_t *)addr;
1793 size = sizeof(netdev_features_t);
1794 break;
1795 default:
1796 return error_string(buf, end, "(%pN?)", spec);
1797 }
1798
1799 return special_hex_number(buf, end, num, size);
1800 }
1801
1802 static noinline_for_stack
fourcc_string(char * buf,char * end,const u32 * fourcc,struct printf_spec spec,const char * fmt)1803 char *fourcc_string(char *buf, char *end, const u32 *fourcc,
1804 struct printf_spec spec, const char *fmt)
1805 {
1806 char output[sizeof("0123 little-endian (0x01234567)")];
1807 char *p = output;
1808 unsigned int i;
1809 bool pixel_fmt = false;
1810 u32 orig, val;
1811
1812 if (fmt[1] != 'c')
1813 return error_string(buf, end, "(%p4?)", spec);
1814
1815 if (check_pointer(&buf, end, fourcc, spec))
1816 return buf;
1817
1818 orig = get_unaligned(fourcc);
1819 switch (fmt[2]) {
1820 case 'h':
1821 if (fmt[3] == 'R')
1822 orig = swab32(orig);
1823 break;
1824 case 'l':
1825 orig = (__force u32)cpu_to_le32(orig);
1826 break;
1827 case 'b':
1828 orig = (__force u32)cpu_to_be32(orig);
1829 break;
1830 case 'c':
1831 /* Pixel formats are printed LSB-first */
1832 pixel_fmt = true;
1833 break;
1834 default:
1835 return error_string(buf, end, "(%p4?)", spec);
1836 }
1837
1838 val = pixel_fmt ? swab32(orig & ~BIT(31)) : orig;
1839
1840 for (i = 0; i < sizeof(u32); i++) {
1841 unsigned char c = val >> ((3 - i) * 8);
1842
1843 /* Print non-control ASCII characters as-is, dot otherwise */
1844 *p++ = isascii(c) && isprint(c) ? c : '.';
1845 }
1846
1847 if (pixel_fmt) {
1848 *p++ = ' ';
1849 strcpy(p, orig & BIT(31) ? "big-endian" : "little-endian");
1850 p += strlen(p);
1851 }
1852
1853 *p++ = ' ';
1854 *p++ = '(';
1855 p = special_hex_number(p, output + sizeof(output) - 2, orig, sizeof(u32));
1856 *p++ = ')';
1857 *p = '\0';
1858
1859 return string(buf, end, output, spec);
1860 }
1861
1862 static noinline_for_stack
address_val(char * buf,char * end,const void * addr,struct printf_spec spec,const char * fmt)1863 char *address_val(char *buf, char *end, const void *addr,
1864 struct printf_spec spec, const char *fmt)
1865 {
1866 unsigned long long num;
1867 int size;
1868
1869 if (check_pointer(&buf, end, addr, spec))
1870 return buf;
1871
1872 switch (fmt[1]) {
1873 case 'd':
1874 num = *(const dma_addr_t *)addr;
1875 size = sizeof(dma_addr_t);
1876 break;
1877 case 'p':
1878 default:
1879 num = *(const phys_addr_t *)addr;
1880 size = sizeof(phys_addr_t);
1881 break;
1882 }
1883
1884 return special_hex_number(buf, end, num, size);
1885 }
1886
1887 static noinline_for_stack
date_str(char * buf,char * end,const struct rtc_time * tm,bool r)1888 char *date_str(char *buf, char *end, const struct rtc_time *tm, bool r)
1889 {
1890 int year = tm->tm_year + (r ? 0 : 1900);
1891 int mon = tm->tm_mon + (r ? 0 : 1);
1892
1893 buf = number(buf, end, year, default_dec04_spec);
1894 if (buf < end)
1895 *buf = '-';
1896 buf++;
1897
1898 buf = number(buf, end, mon, default_dec02_spec);
1899 if (buf < end)
1900 *buf = '-';
1901 buf++;
1902
1903 return number(buf, end, tm->tm_mday, default_dec02_spec);
1904 }
1905
1906 static noinline_for_stack
time_str(char * buf,char * end,const struct rtc_time * tm,bool r)1907 char *time_str(char *buf, char *end, const struct rtc_time *tm, bool r)
1908 {
1909 buf = number(buf, end, tm->tm_hour, default_dec02_spec);
1910 if (buf < end)
1911 *buf = ':';
1912 buf++;
1913
1914 buf = number(buf, end, tm->tm_min, default_dec02_spec);
1915 if (buf < end)
1916 *buf = ':';
1917 buf++;
1918
1919 return number(buf, end, tm->tm_sec, default_dec02_spec);
1920 }
1921
1922 static noinline_for_stack
rtc_str(char * buf,char * end,const struct rtc_time * tm,struct printf_spec spec,const char * fmt)1923 char *rtc_str(char *buf, char *end, const struct rtc_time *tm,
1924 struct printf_spec spec, const char *fmt)
1925 {
1926 bool have_t = true, have_d = true;
1927 bool raw = false, iso8601_separator = true;
1928 bool found = true;
1929 int count = 2;
1930
1931 if (check_pointer(&buf, end, tm, spec))
1932 return buf;
1933
1934 switch (fmt[count]) {
1935 case 'd':
1936 have_t = false;
1937 count++;
1938 break;
1939 case 't':
1940 have_d = false;
1941 count++;
1942 break;
1943 }
1944
1945 do {
1946 switch (fmt[count++]) {
1947 case 'r':
1948 raw = true;
1949 break;
1950 case 's':
1951 iso8601_separator = false;
1952 break;
1953 default:
1954 found = false;
1955 break;
1956 }
1957 } while (found);
1958
1959 if (have_d)
1960 buf = date_str(buf, end, tm, raw);
1961 if (have_d && have_t) {
1962 if (buf < end)
1963 *buf = iso8601_separator ? 'T' : ' ';
1964 buf++;
1965 }
1966 if (have_t)
1967 buf = time_str(buf, end, tm, raw);
1968
1969 return buf;
1970 }
1971
1972 static noinline_for_stack
time64_str(char * buf,char * end,const time64_t time,struct printf_spec spec,const char * fmt)1973 char *time64_str(char *buf, char *end, const time64_t time,
1974 struct printf_spec spec, const char *fmt)
1975 {
1976 struct rtc_time rtc_time;
1977 struct tm tm;
1978
1979 time64_to_tm(time, 0, &tm);
1980
1981 rtc_time.tm_sec = tm.tm_sec;
1982 rtc_time.tm_min = tm.tm_min;
1983 rtc_time.tm_hour = tm.tm_hour;
1984 rtc_time.tm_mday = tm.tm_mday;
1985 rtc_time.tm_mon = tm.tm_mon;
1986 rtc_time.tm_year = tm.tm_year;
1987 rtc_time.tm_wday = tm.tm_wday;
1988 rtc_time.tm_yday = tm.tm_yday;
1989
1990 rtc_time.tm_isdst = 0;
1991
1992 return rtc_str(buf, end, &rtc_time, spec, fmt);
1993 }
1994
1995 static noinline_for_stack
time_and_date(char * buf,char * end,void * ptr,struct printf_spec spec,const char * fmt)1996 char *time_and_date(char *buf, char *end, void *ptr, struct printf_spec spec,
1997 const char *fmt)
1998 {
1999 switch (fmt[1]) {
2000 case 'R':
2001 return rtc_str(buf, end, (const struct rtc_time *)ptr, spec, fmt);
2002 case 'T':
2003 return time64_str(buf, end, *(const time64_t *)ptr, spec, fmt);
2004 default:
2005 return error_string(buf, end, "(%pt?)", spec);
2006 }
2007 }
2008
2009 static noinline_for_stack
clock(char * buf,char * end,struct clk * clk,struct printf_spec spec,const char * fmt)2010 char *clock(char *buf, char *end, struct clk *clk, struct printf_spec spec,
2011 const char *fmt)
2012 {
2013 if (!IS_ENABLED(CONFIG_HAVE_CLK))
2014 return error_string(buf, end, "(%pC?)", spec);
2015
2016 if (check_pointer(&buf, end, clk, spec))
2017 return buf;
2018
2019 #ifdef CONFIG_COMMON_CLK
2020 return string(buf, end, __clk_get_name(clk), spec);
2021 #else
2022 return ptr_to_id(buf, end, clk, spec);
2023 #endif
2024 }
2025
2026 static
format_flags(char * buf,char * end,unsigned long flags,const struct trace_print_flags * names)2027 char *format_flags(char *buf, char *end, unsigned long flags,
2028 const struct trace_print_flags *names)
2029 {
2030 unsigned long mask;
2031
2032 for ( ; flags && names->name; names++) {
2033 mask = names->mask;
2034 if ((flags & mask) != mask)
2035 continue;
2036
2037 buf = string(buf, end, names->name, default_str_spec);
2038
2039 flags &= ~mask;
2040 if (flags) {
2041 if (buf < end)
2042 *buf = '|';
2043 buf++;
2044 }
2045 }
2046
2047 if (flags)
2048 buf = number(buf, end, flags, default_flag_spec);
2049
2050 return buf;
2051 }
2052
2053 struct page_flags_fields {
2054 int width;
2055 int shift;
2056 int mask;
2057 const struct printf_spec *spec;
2058 const char *name;
2059 };
2060
2061 static const struct page_flags_fields pff[] = {
2062 {SECTIONS_WIDTH, SECTIONS_PGSHIFT, SECTIONS_MASK,
2063 &default_dec_spec, "section"},
2064 {NODES_WIDTH, NODES_PGSHIFT, NODES_MASK,
2065 &default_dec_spec, "node"},
2066 {ZONES_WIDTH, ZONES_PGSHIFT, ZONES_MASK,
2067 &default_dec_spec, "zone"},
2068 {LAST_CPUPID_WIDTH, LAST_CPUPID_PGSHIFT, LAST_CPUPID_MASK,
2069 &default_flag_spec, "lastcpupid"},
2070 {KASAN_TAG_WIDTH, KASAN_TAG_PGSHIFT, KASAN_TAG_MASK,
2071 &default_flag_spec, "kasantag"},
2072 };
2073
2074 static
format_page_flags(char * buf,char * end,unsigned long flags)2075 char *format_page_flags(char *buf, char *end, unsigned long flags)
2076 {
2077 unsigned long main_flags = flags & PAGEFLAGS_MASK;
2078 bool append = false;
2079 int i;
2080
2081 buf = number(buf, end, flags, default_flag_spec);
2082 if (buf < end)
2083 *buf = '(';
2084 buf++;
2085
2086 /* Page flags from the main area. */
2087 if (main_flags) {
2088 buf = format_flags(buf, end, main_flags, pageflag_names);
2089 append = true;
2090 }
2091
2092 /* Page flags from the fields area */
2093 for (i = 0; i < ARRAY_SIZE(pff); i++) {
2094 /* Skip undefined fields. */
2095 if (!pff[i].width)
2096 continue;
2097
2098 /* Format: Flag Name + '=' (equals sign) + Number + '|' (separator) */
2099 if (append) {
2100 if (buf < end)
2101 *buf = '|';
2102 buf++;
2103 }
2104
2105 buf = string(buf, end, pff[i].name, default_str_spec);
2106 if (buf < end)
2107 *buf = '=';
2108 buf++;
2109 buf = number(buf, end, (flags >> pff[i].shift) & pff[i].mask,
2110 *pff[i].spec);
2111
2112 append = true;
2113 }
2114 if (buf < end)
2115 *buf = ')';
2116 buf++;
2117
2118 return buf;
2119 }
2120
2121 static noinline_for_stack
flags_string(char * buf,char * end,void * flags_ptr,struct printf_spec spec,const char * fmt)2122 char *flags_string(char *buf, char *end, void *flags_ptr,
2123 struct printf_spec spec, const char *fmt)
2124 {
2125 unsigned long flags;
2126 const struct trace_print_flags *names;
2127
2128 if (check_pointer(&buf, end, flags_ptr, spec))
2129 return buf;
2130
2131 switch (fmt[1]) {
2132 case 'p':
2133 return format_page_flags(buf, end, *(unsigned long *)flags_ptr);
2134 case 'v':
2135 flags = *(unsigned long *)flags_ptr;
2136 names = vmaflag_names;
2137 break;
2138 case 'g':
2139 flags = (__force unsigned long)(*(gfp_t *)flags_ptr);
2140 names = gfpflag_names;
2141 break;
2142 default:
2143 return error_string(buf, end, "(%pG?)", spec);
2144 }
2145
2146 return format_flags(buf, end, flags, names);
2147 }
2148
2149 static noinline_for_stack
fwnode_full_name_string(struct fwnode_handle * fwnode,char * buf,char * end)2150 char *fwnode_full_name_string(struct fwnode_handle *fwnode, char *buf,
2151 char *end)
2152 {
2153 int depth;
2154
2155 /* Loop starting from the root node to the current node. */
2156 for (depth = fwnode_count_parents(fwnode); depth >= 0; depth--) {
2157 /*
2158 * Only get a reference for other nodes (i.e. parent nodes).
2159 * fwnode refcount may be 0 here.
2160 */
2161 struct fwnode_handle *__fwnode = depth ?
2162 fwnode_get_nth_parent(fwnode, depth) : fwnode;
2163
2164 buf = string(buf, end, fwnode_get_name_prefix(__fwnode),
2165 default_str_spec);
2166 buf = string(buf, end, fwnode_get_name(__fwnode),
2167 default_str_spec);
2168
2169 if (depth)
2170 fwnode_handle_put(__fwnode);
2171 }
2172
2173 return buf;
2174 }
2175
2176 static noinline_for_stack
device_node_string(char * buf,char * end,struct device_node * dn,struct printf_spec spec,const char * fmt)2177 char *device_node_string(char *buf, char *end, struct device_node *dn,
2178 struct printf_spec spec, const char *fmt)
2179 {
2180 char tbuf[sizeof("xxxx") + 1];
2181 const char *p;
2182 int ret;
2183 char *buf_start = buf;
2184 struct property *prop;
2185 bool has_mult, pass;
2186
2187 struct printf_spec str_spec = spec;
2188 str_spec.field_width = -1;
2189
2190 if (fmt[0] != 'F')
2191 return error_string(buf, end, "(%pO?)", spec);
2192
2193 if (!IS_ENABLED(CONFIG_OF))
2194 return error_string(buf, end, "(%pOF?)", spec);
2195
2196 if (check_pointer(&buf, end, dn, spec))
2197 return buf;
2198
2199 /* simple case without anything any more format specifiers */
2200 fmt++;
2201 if (fmt[0] == '\0' || strcspn(fmt,"fnpPFcC") > 0)
2202 fmt = "f";
2203
2204 for (pass = false; strspn(fmt,"fnpPFcC"); fmt++, pass = true) {
2205 int precision;
2206 if (pass) {
2207 if (buf < end)
2208 *buf = ':';
2209 buf++;
2210 }
2211
2212 switch (*fmt) {
2213 case 'f': /* full_name */
2214 buf = fwnode_full_name_string(of_fwnode_handle(dn), buf,
2215 end);
2216 break;
2217 case 'n': /* name */
2218 p = fwnode_get_name(of_fwnode_handle(dn));
2219 precision = str_spec.precision;
2220 str_spec.precision = strchrnul(p, '@') - p;
2221 buf = string(buf, end, p, str_spec);
2222 str_spec.precision = precision;
2223 break;
2224 case 'p': /* phandle */
2225 buf = number(buf, end, (unsigned int)dn->phandle, default_dec_spec);
2226 break;
2227 case 'P': /* path-spec */
2228 p = fwnode_get_name(of_fwnode_handle(dn));
2229 if (!p[1])
2230 p = "/";
2231 buf = string(buf, end, p, str_spec);
2232 break;
2233 case 'F': /* flags */
2234 tbuf[0] = of_node_check_flag(dn, OF_DYNAMIC) ? 'D' : '-';
2235 tbuf[1] = of_node_check_flag(dn, OF_DETACHED) ? 'd' : '-';
2236 tbuf[2] = of_node_check_flag(dn, OF_POPULATED) ? 'P' : '-';
2237 tbuf[3] = of_node_check_flag(dn, OF_POPULATED_BUS) ? 'B' : '-';
2238 tbuf[4] = 0;
2239 buf = string_nocheck(buf, end, tbuf, str_spec);
2240 break;
2241 case 'c': /* major compatible string */
2242 ret = of_property_read_string(dn, "compatible", &p);
2243 if (!ret)
2244 buf = string(buf, end, p, str_spec);
2245 break;
2246 case 'C': /* full compatible string */
2247 has_mult = false;
2248 of_property_for_each_string(dn, "compatible", prop, p) {
2249 if (has_mult)
2250 buf = string_nocheck(buf, end, ",", str_spec);
2251 buf = string_nocheck(buf, end, "\"", str_spec);
2252 buf = string(buf, end, p, str_spec);
2253 buf = string_nocheck(buf, end, "\"", str_spec);
2254
2255 has_mult = true;
2256 }
2257 break;
2258 default:
2259 break;
2260 }
2261 }
2262
2263 return widen_string(buf, buf - buf_start, end, spec);
2264 }
2265
2266 static noinline_for_stack
fwnode_string(char * buf,char * end,struct fwnode_handle * fwnode,struct printf_spec spec,const char * fmt)2267 char *fwnode_string(char *buf, char *end, struct fwnode_handle *fwnode,
2268 struct printf_spec spec, const char *fmt)
2269 {
2270 struct printf_spec str_spec = spec;
2271 char *buf_start = buf;
2272
2273 str_spec.field_width = -1;
2274
2275 if (*fmt != 'w')
2276 return error_string(buf, end, "(%pf?)", spec);
2277
2278 if (check_pointer(&buf, end, fwnode, spec))
2279 return buf;
2280
2281 fmt++;
2282
2283 switch (*fmt) {
2284 case 'P': /* name */
2285 buf = string(buf, end, fwnode_get_name(fwnode), str_spec);
2286 break;
2287 case 'f': /* full_name */
2288 default:
2289 buf = fwnode_full_name_string(fwnode, buf, end);
2290 break;
2291 }
2292
2293 return widen_string(buf, buf - buf_start, end, spec);
2294 }
2295
2296 static noinline_for_stack
resource_or_range(const char * fmt,char * buf,char * end,void * ptr,struct printf_spec spec)2297 char *resource_or_range(const char *fmt, char *buf, char *end, void *ptr,
2298 struct printf_spec spec)
2299 {
2300 if (*fmt == 'r' && fmt[1] == 'a')
2301 return range_string(buf, end, ptr, spec, fmt);
2302 return resource_string(buf, end, ptr, spec, fmt);
2303 }
2304
hash_pointers_finalize(bool slub_debug)2305 void __init hash_pointers_finalize(bool slub_debug)
2306 {
2307 switch (hash_pointers_mode) {
2308 case HASH_PTR_ALWAYS:
2309 no_hash_pointers = false;
2310 break;
2311 case HASH_PTR_NEVER:
2312 no_hash_pointers = true;
2313 break;
2314 case HASH_PTR_AUTO:
2315 default:
2316 no_hash_pointers = slub_debug;
2317 break;
2318 }
2319
2320 if (!no_hash_pointers)
2321 return;
2322
2323 pr_warn("**********************************************************\n");
2324 pr_warn("** NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE **\n");
2325 pr_warn("** **\n");
2326 pr_warn("** This system shows unhashed kernel memory addresses **\n");
2327 pr_warn("** via the console, logs, and other interfaces. This **\n");
2328 pr_warn("** might reduce the security of your system. **\n");
2329 pr_warn("** **\n");
2330 pr_warn("** If you see this message and you are not debugging **\n");
2331 pr_warn("** the kernel, report this immediately to your system **\n");
2332 pr_warn("** administrator! **\n");
2333 pr_warn("** **\n");
2334 pr_warn("** Use hash_pointers=always to force this mode off **\n");
2335 pr_warn("** **\n");
2336 pr_warn("** NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE **\n");
2337 pr_warn("**********************************************************\n");
2338 }
2339
hash_pointers_mode_parse(char * str)2340 static int __init hash_pointers_mode_parse(char *str)
2341 {
2342 if (!str) {
2343 pr_warn("Hash pointers mode empty; falling back to auto.\n");
2344 hash_pointers_mode = HASH_PTR_AUTO;
2345 } else if (strncmp(str, "auto", 4) == 0) {
2346 pr_info("Hash pointers mode set to auto.\n");
2347 hash_pointers_mode = HASH_PTR_AUTO;
2348 } else if (strncmp(str, "never", 5) == 0) {
2349 pr_info("Hash pointers mode set to never.\n");
2350 hash_pointers_mode = HASH_PTR_NEVER;
2351 } else if (strncmp(str, "always", 6) == 0) {
2352 pr_info("Hash pointers mode set to always.\n");
2353 hash_pointers_mode = HASH_PTR_ALWAYS;
2354 } else {
2355 pr_warn("Unknown hash_pointers mode '%s' specified; assuming auto.\n", str);
2356 hash_pointers_mode = HASH_PTR_AUTO;
2357 }
2358
2359 return 0;
2360 }
2361 early_param("hash_pointers", hash_pointers_mode_parse);
2362
no_hash_pointers_enable(char * str)2363 static int __init no_hash_pointers_enable(char *str)
2364 {
2365 return hash_pointers_mode_parse("never");
2366 }
2367 early_param("no_hash_pointers", no_hash_pointers_enable);
2368
2369 /*
2370 * Show a '%p' thing. A kernel extension is that the '%p' is followed
2371 * by an extra set of alphanumeric characters that are extended format
2372 * specifiers.
2373 *
2374 * Please update scripts/checkpatch.pl when adding/removing conversion
2375 * characters. (Search for "check for vsprintf extension").
2376 *
2377 * Right now we handle:
2378 *
2379 * - 'S' For symbolic direct pointers (or function descriptors) with offset
2380 * - 's' For symbolic direct pointers (or function descriptors) without offset
2381 * - '[Ss]R' as above with __builtin_extract_return_addr() translation
2382 * - 'S[R]b' as above with module build ID (for use in backtraces)
2383 * - '[Ff]' %pf and %pF were obsoleted and later removed in favor of
2384 * %ps and %pS. Be careful when re-using these specifiers.
2385 * - 'B' For backtraced symbolic direct pointers with offset
2386 * - 'Bb' as above with module build ID (for use in backtraces)
2387 * - 'R' For decoded struct resource, e.g., [mem 0x0-0x1f 64bit pref]
2388 * - 'r' For raw struct resource, e.g., [mem 0x0-0x1f flags 0x201]
2389 * - 'ra' For struct ranges, e.g., [range 0x0000000000000000 - 0x00000000000000ff]
2390 * - 'b[l]' For a bitmap, the number of bits is determined by the field
2391 * width which must be explicitly specified either as part of the
2392 * format string '%32b[l]' or through '%*b[l]', [l] selects
2393 * range-list format instead of hex format
2394 * - 'M' For a 6-byte MAC address, it prints the address in the
2395 * usual colon-separated hex notation
2396 * - 'm' For a 6-byte MAC address, it prints the hex address without colons
2397 * - 'MF' For a 6-byte MAC FDDI address, it prints the address
2398 * with a dash-separated hex notation
2399 * - '[mM]R' For a 6-byte MAC address, Reverse order (Bluetooth)
2400 * - 'I' [46] for IPv4/IPv6 addresses printed in the usual way
2401 * IPv4 uses dot-separated decimal without leading 0's (1.2.3.4)
2402 * IPv6 uses colon separated network-order 16 bit hex with leading 0's
2403 * [S][pfs]
2404 * Generic IPv4/IPv6 address (struct sockaddr *) that falls back to
2405 * [4] or [6] and is able to print port [p], flowinfo [f], scope [s]
2406 * - 'i' [46] for 'raw' IPv4/IPv6 addresses
2407 * IPv6 omits the colons (01020304...0f)
2408 * IPv4 uses dot-separated decimal with leading 0's (010.123.045.006)
2409 * [S][pfs]
2410 * Generic IPv4/IPv6 address (struct sockaddr *) that falls back to
2411 * [4] or [6] and is able to print port [p], flowinfo [f], scope [s]
2412 * - '[Ii][4S][hnbl]' IPv4 addresses in host, network, big or little endian order
2413 * - 'I[6S]c' for IPv6 addresses printed as specified by
2414 * https://tools.ietf.org/html/rfc5952
2415 * - 'E[achnops]' For an escaped buffer, where rules are defined by combination
2416 * of the following flags (see string_escape_mem() for the
2417 * details):
2418 * a - ESCAPE_ANY
2419 * c - ESCAPE_SPECIAL
2420 * h - ESCAPE_HEX
2421 * n - ESCAPE_NULL
2422 * o - ESCAPE_OCTAL
2423 * p - ESCAPE_NP
2424 * s - ESCAPE_SPACE
2425 * By default ESCAPE_ANY_NP is used.
2426 * - 'U' For a 16 byte UUID/GUID, it prints the UUID/GUID in the form
2427 * "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx"
2428 * Options for %pU are:
2429 * b big endian lower case hex (default)
2430 * B big endian UPPER case hex
2431 * l little endian lower case hex
2432 * L little endian UPPER case hex
2433 * big endian output byte order is:
2434 * [0][1][2][3]-[4][5]-[6][7]-[8][9]-[10][11][12][13][14][15]
2435 * little endian output byte order is:
2436 * [3][2][1][0]-[5][4]-[7][6]-[8][9]-[10][11][12][13][14][15]
2437 * - 'V' For a struct va_format which contains a format string * and va_list *,
2438 * call vsnprintf(->format, *->va_list).
2439 * Implements a "recursive vsnprintf".
2440 * Do not use this feature without some mechanism to verify the
2441 * correctness of the format string and va_list arguments.
2442 * - 'K' For a kernel pointer that should be hidden from unprivileged users.
2443 * Use only for procfs, sysfs and similar files, not printk(); please
2444 * read the documentation (path below) first.
2445 * - 'NF' For a netdev_features_t
2446 * - '4cc' V4L2 or DRM FourCC code, with endianness and raw numerical value.
2447 * - '4c[h[R]lb]' For generic FourCC code with raw numerical value. Both are
2448 * displayed in the big-endian format. This is the opposite of V4L2 or
2449 * DRM FourCCs.
2450 * The additional specifiers define what endianness is used to load
2451 * the stored bytes. The data might be interpreted using the host,
2452 * reversed host byte order, little-endian, or big-endian.
2453 * - 'h[CDN]' For a variable-length buffer, it prints it as a hex string with
2454 * a certain separator (' ' by default):
2455 * C colon
2456 * D dash
2457 * N no separator
2458 * The maximum supported length is 64 bytes of the input. Consider
2459 * to use print_hex_dump() for the larger input.
2460 * - 'a[pd]' For address types [p] phys_addr_t, [d] dma_addr_t and derivatives
2461 * (default assumed to be phys_addr_t, passed by reference)
2462 * - 'd[234]' For a dentry name (optionally 2-4 last components)
2463 * - 'D[234]' Same as 'd' but for a struct file
2464 * - 'g' For block_device name (gendisk + partition number)
2465 * - 't[RT][dt][r][s]' For time and date as represented by:
2466 * R struct rtc_time
2467 * T time64_t
2468 * - 'C' For a clock, it prints the name (Common Clock Framework) or address
2469 * (legacy clock framework) of the clock
2470 * - 'G' For flags to be printed as a collection of symbolic strings that would
2471 * construct the specific value. Supported flags given by option:
2472 * p page flags (see struct page) given as pointer to unsigned long
2473 * g gfp flags (GFP_* and __GFP_*) given as pointer to gfp_t
2474 * v vma flags (VM_*) given as pointer to unsigned long
2475 * - 'OF[fnpPcCF]' For a device tree object
2476 * Without any optional arguments prints the full_name
2477 * f device node full_name
2478 * n device node name
2479 * p device node phandle
2480 * P device node path spec (name + @unit)
2481 * F device node flags
2482 * c major compatible string
2483 * C full compatible string
2484 * - 'fw[fP]' For a firmware node (struct fwnode_handle) pointer
2485 * Without an option prints the full name of the node
2486 * f full name
2487 * P node name, including a possible unit address
2488 * - 'x' For printing the address unmodified. Equivalent to "%lx".
2489 * Please read the documentation (path below) before using!
2490 * - '[ku]s' For a BPF/tracing related format specifier, e.g. used out of
2491 * bpf_trace_printk() where [ku] prefix specifies either kernel (k)
2492 * or user (u) memory to probe, and:
2493 * s a string, equivalent to "%s" on direct vsnprintf() use
2494 *
2495 * ** When making changes please also update:
2496 * Documentation/core-api/printk-formats.rst
2497 *
2498 * Note: The default behaviour (unadorned %p) is to hash the address,
2499 * rendering it useful as a unique identifier.
2500 *
2501 * There is also a '%pA' format specifier, but it is only intended to be used
2502 * from Rust code to format core::fmt::Arguments. Do *not* use it from C.
2503 * See rust/kernel/print.rs for details.
2504 */
2505 static noinline_for_stack
pointer(const char * fmt,char * buf,char * end,void * ptr,struct printf_spec spec)2506 char *pointer(const char *fmt, char *buf, char *end, void *ptr,
2507 struct printf_spec spec)
2508 {
2509 switch (*fmt) {
2510 case 'S':
2511 case 's':
2512 ptr = dereference_symbol_descriptor(ptr);
2513 fallthrough;
2514 case 'B':
2515 return symbol_string(buf, end, ptr, spec, fmt);
2516 case 'R':
2517 case 'r':
2518 return resource_or_range(fmt, buf, end, ptr, spec);
2519 case 'h':
2520 return hex_string(buf, end, ptr, spec, fmt);
2521 case 'b':
2522 switch (fmt[1]) {
2523 case 'l':
2524 return bitmap_list_string(buf, end, ptr, spec, fmt);
2525 default:
2526 return bitmap_string(buf, end, ptr, spec, fmt);
2527 }
2528 case 'M': /* Colon separated: 00:01:02:03:04:05 */
2529 case 'm': /* Contiguous: 000102030405 */
2530 /* [mM]F (FDDI) */
2531 /* [mM]R (Reverse order; Bluetooth) */
2532 return mac_address_string(buf, end, ptr, spec, fmt);
2533 case 'I': /* Formatted IP supported
2534 * 4: 1.2.3.4
2535 * 6: 0001:0203:...:0708
2536 * 6c: 1::708 or 1::1.2.3.4
2537 */
2538 case 'i': /* Contiguous:
2539 * 4: 001.002.003.004
2540 * 6: 000102...0f
2541 */
2542 return ip_addr_string(buf, end, ptr, spec, fmt);
2543 case 'E':
2544 return escaped_string(buf, end, ptr, spec, fmt);
2545 case 'U':
2546 return uuid_string(buf, end, ptr, spec, fmt);
2547 case 'V':
2548 return va_format(buf, end, ptr, spec);
2549 case 'K':
2550 return restricted_pointer(buf, end, ptr, spec);
2551 case 'N':
2552 return netdev_bits(buf, end, ptr, spec, fmt);
2553 case '4':
2554 return fourcc_string(buf, end, ptr, spec, fmt);
2555 case 'a':
2556 return address_val(buf, end, ptr, spec, fmt);
2557 case 'd':
2558 return dentry_name(buf, end, ptr, spec, fmt);
2559 case 't':
2560 return time_and_date(buf, end, ptr, spec, fmt);
2561 case 'C':
2562 return clock(buf, end, ptr, spec, fmt);
2563 case 'D':
2564 return file_dentry_name(buf, end, ptr, spec, fmt);
2565 #ifdef CONFIG_BLOCK
2566 case 'g':
2567 return bdev_name(buf, end, ptr, spec, fmt);
2568 #endif
2569
2570 case 'G':
2571 return flags_string(buf, end, ptr, spec, fmt);
2572 case 'O':
2573 return device_node_string(buf, end, ptr, spec, fmt + 1);
2574 case 'f':
2575 return fwnode_string(buf, end, ptr, spec, fmt + 1);
2576 case 'A':
2577 if (!IS_ENABLED(CONFIG_RUST)) {
2578 WARN_ONCE(1, "Please remove %%pA from non-Rust code\n");
2579 return error_string(buf, end, "(%pA?)", spec);
2580 }
2581 return rust_fmt_argument(buf, end, ptr);
2582 case 'x':
2583 return pointer_string(buf, end, ptr, spec);
2584 case 'e':
2585 /* %pe with a non-ERR_PTR gets treated as plain %p */
2586 if (!IS_ERR(ptr))
2587 return default_pointer(buf, end, ptr, spec);
2588 return err_ptr(buf, end, ptr, spec);
2589 case 'u':
2590 case 'k':
2591 switch (fmt[1]) {
2592 case 's':
2593 return string(buf, end, ptr, spec);
2594 default:
2595 return error_string(buf, end, "(einval)", spec);
2596 }
2597 default:
2598 return default_pointer(buf, end, ptr, spec);
2599 }
2600 }
2601
2602 struct fmt {
2603 const char *str;
2604 unsigned char state; // enum format_state
2605 unsigned char size; // size of numbers
2606 };
2607
2608 #define SPEC_CHAR(x, flag) [(x)-32] = flag
spec_flag(unsigned char c)2609 static unsigned char spec_flag(unsigned char c)
2610 {
2611 static const unsigned char spec_flag_array[] = {
2612 SPEC_CHAR(' ', SPACE),
2613 SPEC_CHAR('#', SPECIAL),
2614 SPEC_CHAR('+', PLUS),
2615 SPEC_CHAR('-', LEFT),
2616 SPEC_CHAR('0', ZEROPAD),
2617 };
2618 c -= 32;
2619 return (c < sizeof(spec_flag_array)) ? spec_flag_array[c] : 0;
2620 }
2621
2622 /*
2623 * Helper function to decode printf style format.
2624 * Each call decode a token from the format and return the
2625 * number of characters read (or likely the delta where it wants
2626 * to go on the next call).
2627 * The decoded token is returned through the parameters
2628 *
2629 * 'h', 'l', or 'L' for integer fields
2630 * 'z' support added 23/7/1999 S.H.
2631 * 'z' changed to 'Z' --davidm 1/25/99
2632 * 'Z' changed to 'z' --adobriyan 2017-01-25
2633 * 't' added for ptrdiff_t
2634 *
2635 * @fmt: the format string
2636 * @type of the token returned
2637 * @flags: various flags such as +, -, # tokens..
2638 * @field_width: overwritten width
2639 * @base: base of the number (octal, hex, ...)
2640 * @precision: precision of a number
2641 * @qualifier: qualifier of a number (long, size_t, ...)
2642 */
2643 static noinline_for_stack
format_decode(struct fmt fmt,struct printf_spec * spec)2644 struct fmt format_decode(struct fmt fmt, struct printf_spec *spec)
2645 {
2646 const char *start = fmt.str;
2647 char flag;
2648
2649 /* we finished early by reading the field width */
2650 if (unlikely(fmt.state == FORMAT_STATE_WIDTH)) {
2651 if (spec->field_width < 0) {
2652 spec->field_width = -spec->field_width;
2653 spec->flags |= LEFT;
2654 }
2655 fmt.state = FORMAT_STATE_NONE;
2656 goto precision;
2657 }
2658
2659 /* we finished early by reading the precision */
2660 if (unlikely(fmt.state == FORMAT_STATE_PRECISION)) {
2661 if (spec->precision < 0)
2662 spec->precision = 0;
2663
2664 fmt.state = FORMAT_STATE_NONE;
2665 goto qualifier;
2666 }
2667
2668 /* By default */
2669 fmt.state = FORMAT_STATE_NONE;
2670
2671 for (; *fmt.str ; fmt.str++) {
2672 if (*fmt.str == '%')
2673 break;
2674 }
2675
2676 /* Return the current non-format string */
2677 if (fmt.str != start || !*fmt.str)
2678 return fmt;
2679
2680 /* Process flags. This also skips the first '%' */
2681 spec->flags = 0;
2682 do {
2683 /* this also skips first '%' */
2684 flag = spec_flag(*++fmt.str);
2685 spec->flags |= flag;
2686 } while (flag);
2687
2688 /* get field width */
2689 spec->field_width = -1;
2690
2691 if (isdigit(*fmt.str))
2692 spec->field_width = skip_atoi(&fmt.str);
2693 else if (unlikely(*fmt.str == '*')) {
2694 /* it's the next argument */
2695 fmt.state = FORMAT_STATE_WIDTH;
2696 fmt.str++;
2697 return fmt;
2698 }
2699
2700 precision:
2701 /* get the precision */
2702 spec->precision = -1;
2703 if (unlikely(*fmt.str == '.')) {
2704 fmt.str++;
2705 if (isdigit(*fmt.str)) {
2706 spec->precision = skip_atoi(&fmt.str);
2707 if (spec->precision < 0)
2708 spec->precision = 0;
2709 } else if (*fmt.str == '*') {
2710 /* it's the next argument */
2711 fmt.state = FORMAT_STATE_PRECISION;
2712 fmt.str++;
2713 return fmt;
2714 }
2715 }
2716
2717 qualifier:
2718 /* Set up default numeric format */
2719 spec->base = 10;
2720 fmt.state = FORMAT_STATE_NUM;
2721 fmt.size = sizeof(int);
2722 static const struct format_state {
2723 unsigned char state;
2724 unsigned char size;
2725 unsigned char flags_or_double_size;
2726 unsigned char base;
2727 } lookup_state[256] = {
2728 // Length
2729 ['l'] = { 0, sizeof(long), sizeof(long long) },
2730 ['L'] = { 0, sizeof(long long) },
2731 ['h'] = { 0, sizeof(short), sizeof(char) },
2732 ['H'] = { 0, sizeof(char) }, // Questionable historical
2733 ['z'] = { 0, sizeof(size_t) },
2734 ['t'] = { 0, sizeof(ptrdiff_t) },
2735
2736 // Non-numeric formats
2737 ['c'] = { FORMAT_STATE_CHAR },
2738 ['s'] = { FORMAT_STATE_STR },
2739 ['p'] = { FORMAT_STATE_PTR },
2740 ['%'] = { FORMAT_STATE_PERCENT_CHAR },
2741
2742 // Numerics
2743 ['o'] = { FORMAT_STATE_NUM, 0, 0, 8 },
2744 ['x'] = { FORMAT_STATE_NUM, 0, SMALL, 16 },
2745 ['X'] = { FORMAT_STATE_NUM, 0, 0, 16 },
2746 ['d'] = { FORMAT_STATE_NUM, 0, SIGN, 10 },
2747 ['i'] = { FORMAT_STATE_NUM, 0, SIGN, 10 },
2748 ['u'] = { FORMAT_STATE_NUM, 0, 0, 10, },
2749
2750 /*
2751 * Since %n poses a greater security risk than
2752 * utility, treat it as any other invalid or
2753 * unsupported format specifier.
2754 */
2755 };
2756
2757 const struct format_state *p = lookup_state + (u8)*fmt.str;
2758 if (p->size) {
2759 fmt.size = p->size;
2760 if (p->flags_or_double_size && fmt.str[0] == fmt.str[1]) {
2761 fmt.size = p->flags_or_double_size;
2762 fmt.str++;
2763 }
2764 fmt.str++;
2765 p = lookup_state + *fmt.str;
2766 }
2767 if (p->state) {
2768 if (p->base)
2769 spec->base = p->base;
2770 spec->flags |= p->flags_or_double_size;
2771 fmt.state = p->state;
2772 fmt.str++;
2773 return fmt;
2774 }
2775
2776 WARN_ONCE(1, "Please remove unsupported %%%c in format string\n", *fmt.str);
2777 fmt.state = FORMAT_STATE_INVALID;
2778 return fmt;
2779 }
2780
2781 static void
set_field_width(struct printf_spec * spec,int width)2782 set_field_width(struct printf_spec *spec, int width)
2783 {
2784 spec->field_width = width;
2785 if (WARN_ONCE(spec->field_width != width, "field width %d too large", width)) {
2786 spec->field_width = clamp(width, -FIELD_WIDTH_MAX, FIELD_WIDTH_MAX);
2787 }
2788 }
2789
2790 static void
set_precision(struct printf_spec * spec,int prec)2791 set_precision(struct printf_spec *spec, int prec)
2792 {
2793 spec->precision = prec;
2794 if (WARN_ONCE(spec->precision != prec, "precision %d too large", prec)) {
2795 spec->precision = clamp(prec, 0, PRECISION_MAX);
2796 }
2797 }
2798
2799 /*
2800 * Turn a 1/2/4-byte value into a 64-bit one for printing: truncate
2801 * as necessary and deal with signedness.
2802 *
2803 * 'size' is the size of the value in bytes.
2804 */
convert_num_spec(unsigned int val,int size,struct printf_spec spec)2805 static unsigned long long convert_num_spec(unsigned int val, int size, struct printf_spec spec)
2806 {
2807 unsigned int shift = 32 - size*8;
2808
2809 val <<= shift;
2810 if (!(spec.flags & SIGN))
2811 return val >> shift;
2812 return (int)val >> shift;
2813 }
2814
2815 /**
2816 * vsnprintf - Format a string and place it in a buffer
2817 * @buf: The buffer to place the result into
2818 * @size: The size of the buffer, including the trailing null space
2819 * @fmt_str: The format string to use
2820 * @args: Arguments for the format string
2821 *
2822 * This function generally follows C99 vsnprintf, but has some
2823 * extensions and a few limitations:
2824 *
2825 * - ``%n`` is unsupported
2826 * - ``%p*`` is handled by pointer()
2827 *
2828 * See pointer() or Documentation/core-api/printk-formats.rst for more
2829 * extensive description.
2830 *
2831 * **Please update the documentation in both places when making changes**
2832 *
2833 * The return value is the number of characters which would
2834 * be generated for the given input, excluding the trailing
2835 * '\0', as per ISO C99. If you want to have the exact
2836 * number of characters written into @buf as return value
2837 * (not including the trailing '\0'), use vscnprintf(). If the
2838 * return is greater than or equal to @size, the resulting
2839 * string is truncated.
2840 *
2841 * If you're not already dealing with a va_list consider using snprintf().
2842 */
vsnprintf(char * buf,size_t size,const char * fmt_str,va_list args)2843 int vsnprintf(char *buf, size_t size, const char *fmt_str, va_list args)
2844 {
2845 char *str, *end;
2846 struct printf_spec spec = {0};
2847 struct fmt fmt = {
2848 .str = fmt_str,
2849 .state = FORMAT_STATE_NONE,
2850 };
2851
2852 /* Reject out-of-range values early. Large positive sizes are
2853 used for unknown buffer sizes. */
2854 if (WARN_ON_ONCE(size > INT_MAX))
2855 return 0;
2856
2857 str = buf;
2858 end = buf + size;
2859
2860 /* Make sure end is always >= buf */
2861 if (end < buf) {
2862 end = ((void *)-1);
2863 size = end - buf;
2864 }
2865
2866 while (*fmt.str) {
2867 const char *old_fmt = fmt.str;
2868
2869 fmt = format_decode(fmt, &spec);
2870
2871 switch (fmt.state) {
2872 case FORMAT_STATE_NONE: {
2873 int read = fmt.str - old_fmt;
2874 if (str < end) {
2875 int copy = read;
2876 if (copy > end - str)
2877 copy = end - str;
2878 memcpy(str, old_fmt, copy);
2879 }
2880 str += read;
2881 continue;
2882 }
2883
2884 case FORMAT_STATE_NUM: {
2885 unsigned long long num;
2886 if (fmt.size <= sizeof(int))
2887 num = convert_num_spec(va_arg(args, int), fmt.size, spec);
2888 else
2889 num = va_arg(args, long long);
2890 str = number(str, end, num, spec);
2891 continue;
2892 }
2893
2894 case FORMAT_STATE_WIDTH:
2895 set_field_width(&spec, va_arg(args, int));
2896 continue;
2897
2898 case FORMAT_STATE_PRECISION:
2899 set_precision(&spec, va_arg(args, int));
2900 continue;
2901
2902 case FORMAT_STATE_CHAR: {
2903 char c;
2904
2905 if (!(spec.flags & LEFT)) {
2906 while (--spec.field_width > 0) {
2907 if (str < end)
2908 *str = ' ';
2909 ++str;
2910
2911 }
2912 }
2913 c = (unsigned char) va_arg(args, int);
2914 if (str < end)
2915 *str = c;
2916 ++str;
2917 while (--spec.field_width > 0) {
2918 if (str < end)
2919 *str = ' ';
2920 ++str;
2921 }
2922 continue;
2923 }
2924
2925 case FORMAT_STATE_STR:
2926 str = string(str, end, va_arg(args, char *), spec);
2927 continue;
2928
2929 case FORMAT_STATE_PTR:
2930 str = pointer(fmt.str, str, end, va_arg(args, void *),
2931 spec);
2932 while (isalnum(*fmt.str))
2933 fmt.str++;
2934 continue;
2935
2936 case FORMAT_STATE_PERCENT_CHAR:
2937 if (str < end)
2938 *str = '%';
2939 ++str;
2940 continue;
2941
2942 default:
2943 /*
2944 * Presumably the arguments passed gcc's type
2945 * checking, but there is no safe or sane way
2946 * for us to continue parsing the format and
2947 * fetching from the va_list; the remaining
2948 * specifiers and arguments would be out of
2949 * sync.
2950 */
2951 goto out;
2952 }
2953 }
2954
2955 out:
2956 if (size > 0) {
2957 if (str < end)
2958 *str = '\0';
2959 else
2960 end[-1] = '\0';
2961 }
2962
2963 /* the trailing null byte doesn't count towards the total */
2964 return str-buf;
2965
2966 }
2967 EXPORT_SYMBOL(vsnprintf);
2968
2969 /**
2970 * vscnprintf - Format a string and place it in a buffer
2971 * @buf: The buffer to place the result into
2972 * @size: The size of the buffer, including the trailing null space
2973 * @fmt: The format string to use
2974 * @args: Arguments for the format string
2975 *
2976 * The return value is the number of characters which have been written into
2977 * the @buf not including the trailing '\0'. If @size is == 0 the function
2978 * returns 0.
2979 *
2980 * If you're not already dealing with a va_list consider using scnprintf().
2981 *
2982 * See the vsnprintf() documentation for format string extensions over C99.
2983 */
vscnprintf(char * buf,size_t size,const char * fmt,va_list args)2984 int vscnprintf(char *buf, size_t size, const char *fmt, va_list args)
2985 {
2986 int i;
2987
2988 if (unlikely(!size))
2989 return 0;
2990
2991 i = vsnprintf(buf, size, fmt, args);
2992
2993 if (likely(i < size))
2994 return i;
2995
2996 return size - 1;
2997 }
2998 EXPORT_SYMBOL(vscnprintf);
2999
3000 /**
3001 * snprintf - Format a string and place it in a buffer
3002 * @buf: The buffer to place the result into
3003 * @size: The size of the buffer, including the trailing null space
3004 * @fmt: The format string to use
3005 * @...: Arguments for the format string
3006 *
3007 * The return value is the number of characters which would be
3008 * generated for the given input, excluding the trailing null,
3009 * as per ISO C99. If the return is greater than or equal to
3010 * @size, the resulting string is truncated.
3011 *
3012 * See the vsnprintf() documentation for format string extensions over C99.
3013 */
snprintf(char * buf,size_t size,const char * fmt,...)3014 int snprintf(char *buf, size_t size, const char *fmt, ...)
3015 {
3016 va_list args;
3017 int i;
3018
3019 va_start(args, fmt);
3020 i = vsnprintf(buf, size, fmt, args);
3021 va_end(args);
3022
3023 return i;
3024 }
3025 EXPORT_SYMBOL(snprintf);
3026
3027 /**
3028 * scnprintf - Format a string and place it in a buffer
3029 * @buf: The buffer to place the result into
3030 * @size: The size of the buffer, including the trailing null space
3031 * @fmt: The format string to use
3032 * @...: Arguments for the format string
3033 *
3034 * The return value is the number of characters written into @buf not including
3035 * the trailing '\0'. If @size is == 0 the function returns 0.
3036 */
3037
scnprintf(char * buf,size_t size,const char * fmt,...)3038 int scnprintf(char *buf, size_t size, const char *fmt, ...)
3039 {
3040 va_list args;
3041 int i;
3042
3043 va_start(args, fmt);
3044 i = vscnprintf(buf, size, fmt, args);
3045 va_end(args);
3046
3047 return i;
3048 }
3049 EXPORT_SYMBOL(scnprintf);
3050
3051 /**
3052 * vsprintf - Format a string and place it in a buffer
3053 * @buf: The buffer to place the result into
3054 * @fmt: The format string to use
3055 * @args: Arguments for the format string
3056 *
3057 * The function returns the number of characters written
3058 * into @buf. Use vsnprintf() or vscnprintf() in order to avoid
3059 * buffer overflows.
3060 *
3061 * If you're not already dealing with a va_list consider using sprintf().
3062 *
3063 * See the vsnprintf() documentation for format string extensions over C99.
3064 */
vsprintf(char * buf,const char * fmt,va_list args)3065 int vsprintf(char *buf, const char *fmt, va_list args)
3066 {
3067 return vsnprintf(buf, INT_MAX, fmt, args);
3068 }
3069 EXPORT_SYMBOL(vsprintf);
3070
3071 /**
3072 * sprintf - Format a string and place it in a buffer
3073 * @buf: The buffer to place the result into
3074 * @fmt: The format string to use
3075 * @...: Arguments for the format string
3076 *
3077 * The function returns the number of characters written
3078 * into @buf. Use snprintf() or scnprintf() in order to avoid
3079 * buffer overflows.
3080 *
3081 * See the vsnprintf() documentation for format string extensions over C99.
3082 */
sprintf(char * buf,const char * fmt,...)3083 int sprintf(char *buf, const char *fmt, ...)
3084 {
3085 va_list args;
3086 int i;
3087
3088 va_start(args, fmt);
3089 i = vsnprintf(buf, INT_MAX, fmt, args);
3090 va_end(args);
3091
3092 return i;
3093 }
3094 EXPORT_SYMBOL(sprintf);
3095
3096 #ifdef CONFIG_BINARY_PRINTF
3097 /*
3098 * bprintf service:
3099 * vbin_printf() - VA arguments to binary data
3100 * bstr_printf() - Binary data to text string
3101 */
3102
3103 /**
3104 * vbin_printf - Parse a format string and place args' binary value in a buffer
3105 * @bin_buf: The buffer to place args' binary value
3106 * @size: The size of the buffer(by words(32bits), not characters)
3107 * @fmt_str: The format string to use
3108 * @args: Arguments for the format string
3109 *
3110 * The format follows C99 vsnprintf, except %n is ignored, and its argument
3111 * is skipped.
3112 *
3113 * The return value is the number of words(32bits) which would be generated for
3114 * the given input.
3115 *
3116 * NOTE:
3117 * If the return value is greater than @size, the resulting bin_buf is NOT
3118 * valid for bstr_printf().
3119 */
vbin_printf(u32 * bin_buf,size_t size,const char * fmt_str,va_list args)3120 int vbin_printf(u32 *bin_buf, size_t size, const char *fmt_str, va_list args)
3121 {
3122 struct fmt fmt = {
3123 .str = fmt_str,
3124 .state = FORMAT_STATE_NONE,
3125 };
3126 struct printf_spec spec = {0};
3127 char *str, *end;
3128 int width;
3129
3130 str = (char *)bin_buf;
3131 end = (char *)(bin_buf + size);
3132
3133 #define save_arg(type) \
3134 ({ \
3135 unsigned long long value; \
3136 if (sizeof(type) == 8) { \
3137 unsigned long long val8; \
3138 str = PTR_ALIGN(str, sizeof(u32)); \
3139 val8 = va_arg(args, unsigned long long); \
3140 if (str + sizeof(type) <= end) { \
3141 *(u32 *)str = *(u32 *)&val8; \
3142 *(u32 *)(str + 4) = *((u32 *)&val8 + 1); \
3143 } \
3144 value = val8; \
3145 } else { \
3146 unsigned int val4; \
3147 str = PTR_ALIGN(str, sizeof(type)); \
3148 val4 = va_arg(args, int); \
3149 if (str + sizeof(type) <= end) \
3150 *(typeof(type) *)str = (type)(long)val4; \
3151 value = (unsigned long long)val4; \
3152 } \
3153 str += sizeof(type); \
3154 value; \
3155 })
3156
3157 while (*fmt.str) {
3158 fmt = format_decode(fmt, &spec);
3159
3160 switch (fmt.state) {
3161 case FORMAT_STATE_NONE:
3162 case FORMAT_STATE_PERCENT_CHAR:
3163 break;
3164 case FORMAT_STATE_INVALID:
3165 goto out;
3166
3167 case FORMAT_STATE_WIDTH:
3168 case FORMAT_STATE_PRECISION:
3169 width = (int)save_arg(int);
3170 /* Pointers may require the width */
3171 if (*fmt.str == 'p')
3172 set_field_width(&spec, width);
3173 break;
3174
3175 case FORMAT_STATE_CHAR:
3176 save_arg(char);
3177 break;
3178
3179 case FORMAT_STATE_STR: {
3180 const char *save_str = va_arg(args, char *);
3181 const char *err_msg;
3182 size_t len;
3183
3184 err_msg = check_pointer_msg(save_str);
3185 if (err_msg)
3186 save_str = err_msg;
3187
3188 len = strlen(save_str) + 1;
3189 if (str + len < end)
3190 memcpy(str, save_str, len);
3191 str += len;
3192 break;
3193 }
3194
3195 case FORMAT_STATE_PTR:
3196 /* Dereferenced pointers must be done now */
3197 switch (*fmt.str) {
3198 /* Dereference of functions is still OK */
3199 case 'S':
3200 case 's':
3201 case 'x':
3202 case 'K':
3203 case 'e':
3204 save_arg(void *);
3205 break;
3206 default:
3207 if (!isalnum(*fmt.str)) {
3208 save_arg(void *);
3209 break;
3210 }
3211 str = pointer(fmt.str, str, end, va_arg(args, void *),
3212 spec);
3213 if (str + 1 < end)
3214 *str++ = '\0';
3215 else
3216 end[-1] = '\0'; /* Must be nul terminated */
3217 }
3218 /* skip all alphanumeric pointer suffixes */
3219 while (isalnum(*fmt.str))
3220 fmt.str++;
3221 break;
3222
3223 case FORMAT_STATE_NUM:
3224 if (fmt.size > sizeof(int)) {
3225 save_arg(long long);
3226 } else {
3227 save_arg(int);
3228 }
3229 }
3230 }
3231
3232 out:
3233 return (u32 *)(PTR_ALIGN(str, sizeof(u32))) - bin_buf;
3234 #undef save_arg
3235 }
3236 EXPORT_SYMBOL_GPL(vbin_printf);
3237
3238 /**
3239 * bstr_printf - Format a string from binary arguments and place it in a buffer
3240 * @buf: The buffer to place the result into
3241 * @size: The size of the buffer, including the trailing null space
3242 * @fmt_str: The format string to use
3243 * @bin_buf: Binary arguments for the format string
3244 *
3245 * This function like C99 vsnprintf, but the difference is that vsnprintf gets
3246 * arguments from stack, and bstr_printf gets arguments from @bin_buf which is
3247 * a binary buffer that generated by vbin_printf.
3248 *
3249 * The format follows C99 vsnprintf, but has some extensions:
3250 * see vsnprintf comment for details.
3251 *
3252 * The return value is the number of characters which would
3253 * be generated for the given input, excluding the trailing
3254 * '\0', as per ISO C99. If you want to have the exact
3255 * number of characters written into @buf as return value
3256 * (not including the trailing '\0'), use vscnprintf(). If the
3257 * return is greater than or equal to @size, the resulting
3258 * string is truncated.
3259 */
bstr_printf(char * buf,size_t size,const char * fmt_str,const u32 * bin_buf)3260 int bstr_printf(char *buf, size_t size, const char *fmt_str, const u32 *bin_buf)
3261 {
3262 struct fmt fmt = {
3263 .str = fmt_str,
3264 .state = FORMAT_STATE_NONE,
3265 };
3266 struct printf_spec spec = {0};
3267 char *str, *end;
3268 const char *args = (const char *)bin_buf;
3269
3270 if (WARN_ON_ONCE(size > INT_MAX))
3271 return 0;
3272
3273 str = buf;
3274 end = buf + size;
3275
3276 #define get_arg(type) \
3277 ({ \
3278 typeof(type) value; \
3279 if (sizeof(type) == 8) { \
3280 args = PTR_ALIGN(args, sizeof(u32)); \
3281 *(u32 *)&value = *(u32 *)args; \
3282 *((u32 *)&value + 1) = *(u32 *)(args + 4); \
3283 } else { \
3284 args = PTR_ALIGN(args, sizeof(type)); \
3285 value = *(typeof(type) *)args; \
3286 } \
3287 args += sizeof(type); \
3288 value; \
3289 })
3290
3291 /* Make sure end is always >= buf */
3292 if (end < buf) {
3293 end = ((void *)-1);
3294 size = end - buf;
3295 }
3296
3297 while (*fmt.str) {
3298 const char *old_fmt = fmt.str;
3299 unsigned long long num;
3300
3301 fmt = format_decode(fmt, &spec);
3302 switch (fmt.state) {
3303 case FORMAT_STATE_NONE: {
3304 int read = fmt.str - old_fmt;
3305 if (str < end) {
3306 int copy = read;
3307 if (copy > end - str)
3308 copy = end - str;
3309 memcpy(str, old_fmt, copy);
3310 }
3311 str += read;
3312 continue;
3313 }
3314
3315 case FORMAT_STATE_WIDTH:
3316 set_field_width(&spec, get_arg(int));
3317 continue;
3318
3319 case FORMAT_STATE_PRECISION:
3320 set_precision(&spec, get_arg(int));
3321 continue;
3322
3323 case FORMAT_STATE_CHAR: {
3324 char c;
3325
3326 if (!(spec.flags & LEFT)) {
3327 while (--spec.field_width > 0) {
3328 if (str < end)
3329 *str = ' ';
3330 ++str;
3331 }
3332 }
3333 c = (unsigned char) get_arg(char);
3334 if (str < end)
3335 *str = c;
3336 ++str;
3337 while (--spec.field_width > 0) {
3338 if (str < end)
3339 *str = ' ';
3340 ++str;
3341 }
3342 continue;
3343 }
3344
3345 case FORMAT_STATE_STR: {
3346 const char *str_arg = args;
3347 args += strlen(str_arg) + 1;
3348 str = string(str, end, (char *)str_arg, spec);
3349 continue;
3350 }
3351
3352 case FORMAT_STATE_PTR: {
3353 bool process = false;
3354 int copy, len;
3355 /* Non function dereferences were already done */
3356 switch (*fmt.str) {
3357 case 'S':
3358 case 's':
3359 case 'x':
3360 case 'K':
3361 case 'e':
3362 process = true;
3363 break;
3364 default:
3365 if (!isalnum(*fmt.str)) {
3366 process = true;
3367 break;
3368 }
3369 /* Pointer dereference was already processed */
3370 if (str < end) {
3371 len = copy = strlen(args);
3372 if (copy > end - str)
3373 copy = end - str;
3374 memcpy(str, args, copy);
3375 str += len;
3376 args += len + 1;
3377 }
3378 }
3379 if (process)
3380 str = pointer(fmt.str, str, end, get_arg(void *), spec);
3381
3382 while (isalnum(*fmt.str))
3383 fmt.str++;
3384 continue;
3385 }
3386
3387 case FORMAT_STATE_PERCENT_CHAR:
3388 if (str < end)
3389 *str = '%';
3390 ++str;
3391 continue;
3392
3393 case FORMAT_STATE_INVALID:
3394 goto out;
3395
3396 case FORMAT_STATE_NUM:
3397 if (fmt.size > sizeof(int)) {
3398 num = get_arg(long long);
3399 } else {
3400 num = convert_num_spec(get_arg(int), fmt.size, spec);
3401 }
3402 str = number(str, end, num, spec);
3403 continue;
3404 }
3405 } /* while(*fmt.str) */
3406
3407 out:
3408 if (size > 0) {
3409 if (str < end)
3410 *str = '\0';
3411 else
3412 end[-1] = '\0';
3413 }
3414
3415 #undef get_arg
3416
3417 /* the trailing null byte doesn't count towards the total */
3418 return str - buf;
3419 }
3420 EXPORT_SYMBOL_GPL(bstr_printf);
3421
3422 #endif /* CONFIG_BINARY_PRINTF */
3423
3424 /**
3425 * vsscanf - Unformat a buffer into a list of arguments
3426 * @buf: input buffer
3427 * @fmt: format of buffer
3428 * @args: arguments
3429 */
vsscanf(const char * buf,const char * fmt,va_list args)3430 int vsscanf(const char *buf, const char *fmt, va_list args)
3431 {
3432 const char *str = buf;
3433 char *next;
3434 char digit;
3435 int num = 0;
3436 u8 qualifier;
3437 unsigned int base;
3438 union {
3439 long long s;
3440 unsigned long long u;
3441 } val;
3442 s16 field_width;
3443 bool is_sign;
3444
3445 while (*fmt) {
3446 /* skip any white space in format */
3447 /* white space in format matches any amount of
3448 * white space, including none, in the input.
3449 */
3450 if (isspace(*fmt)) {
3451 fmt = skip_spaces(++fmt);
3452 str = skip_spaces(str);
3453 }
3454
3455 /* anything that is not a conversion must match exactly */
3456 if (*fmt != '%' && *fmt) {
3457 if (*fmt++ != *str++)
3458 break;
3459 continue;
3460 }
3461
3462 if (!*fmt)
3463 break;
3464 ++fmt;
3465
3466 /* skip this conversion.
3467 * advance both strings to next white space
3468 */
3469 if (*fmt == '*') {
3470 if (!*str)
3471 break;
3472 while (!isspace(*fmt) && *fmt != '%' && *fmt) {
3473 /* '%*[' not yet supported, invalid format */
3474 if (*fmt == '[')
3475 return num;
3476 fmt++;
3477 }
3478 while (!isspace(*str) && *str)
3479 str++;
3480 continue;
3481 }
3482
3483 /* get field width */
3484 field_width = -1;
3485 if (isdigit(*fmt)) {
3486 field_width = skip_atoi(&fmt);
3487 if (field_width <= 0)
3488 break;
3489 }
3490
3491 /* get conversion qualifier */
3492 qualifier = -1;
3493 if (*fmt == 'h' || _tolower(*fmt) == 'l' ||
3494 *fmt == 'z') {
3495 qualifier = *fmt++;
3496 if (unlikely(qualifier == *fmt)) {
3497 if (qualifier == 'h') {
3498 qualifier = 'H';
3499 fmt++;
3500 } else if (qualifier == 'l') {
3501 qualifier = 'L';
3502 fmt++;
3503 }
3504 }
3505 }
3506
3507 if (!*fmt)
3508 break;
3509
3510 if (*fmt == 'n') {
3511 /* return number of characters read so far */
3512 *va_arg(args, int *) = str - buf;
3513 ++fmt;
3514 continue;
3515 }
3516
3517 if (!*str)
3518 break;
3519
3520 base = 10;
3521 is_sign = false;
3522
3523 switch (*fmt++) {
3524 case 'c':
3525 {
3526 char *s = (char *)va_arg(args, char*);
3527 if (field_width == -1)
3528 field_width = 1;
3529 do {
3530 *s++ = *str++;
3531 } while (--field_width > 0 && *str);
3532 num++;
3533 }
3534 continue;
3535 case 's':
3536 {
3537 char *s = (char *)va_arg(args, char *);
3538 if (field_width == -1)
3539 field_width = SHRT_MAX;
3540 /* first, skip leading white space in buffer */
3541 str = skip_spaces(str);
3542
3543 /* now copy until next white space */
3544 while (*str && !isspace(*str) && field_width--)
3545 *s++ = *str++;
3546 *s = '\0';
3547 num++;
3548 }
3549 continue;
3550 /*
3551 * Warning: This implementation of the '[' conversion specifier
3552 * deviates from its glibc counterpart in the following ways:
3553 * (1) It does NOT support ranges i.e. '-' is NOT a special
3554 * character
3555 * (2) It cannot match the closing bracket ']' itself
3556 * (3) A field width is required
3557 * (4) '%*[' (discard matching input) is currently not supported
3558 *
3559 * Example usage:
3560 * ret = sscanf("00:0a:95","%2[^:]:%2[^:]:%2[^:]",
3561 * buf1, buf2, buf3);
3562 * if (ret < 3)
3563 * // etc..
3564 */
3565 case '[':
3566 {
3567 char *s = (char *)va_arg(args, char *);
3568 DECLARE_BITMAP(set, 256) = {0};
3569 unsigned int len = 0;
3570 bool negate = (*fmt == '^');
3571
3572 /* field width is required */
3573 if (field_width == -1)
3574 return num;
3575
3576 if (negate)
3577 ++fmt;
3578
3579 for ( ; *fmt && *fmt != ']'; ++fmt, ++len)
3580 __set_bit((u8)*fmt, set);
3581
3582 /* no ']' or no character set found */
3583 if (!*fmt || !len)
3584 return num;
3585 ++fmt;
3586
3587 if (negate) {
3588 bitmap_complement(set, set, 256);
3589 /* exclude null '\0' byte */
3590 __clear_bit(0, set);
3591 }
3592
3593 /* match must be non-empty */
3594 if (!test_bit((u8)*str, set))
3595 return num;
3596
3597 while (test_bit((u8)*str, set) && field_width--)
3598 *s++ = *str++;
3599 *s = '\0';
3600 ++num;
3601 }
3602 continue;
3603 case 'o':
3604 base = 8;
3605 break;
3606 case 'x':
3607 case 'X':
3608 base = 16;
3609 break;
3610 case 'i':
3611 base = 0;
3612 fallthrough;
3613 case 'd':
3614 is_sign = true;
3615 fallthrough;
3616 case 'u':
3617 break;
3618 case '%':
3619 /* looking for '%' in str */
3620 if (*str++ != '%')
3621 return num;
3622 continue;
3623 default:
3624 /* invalid format; stop here */
3625 return num;
3626 }
3627
3628 /* have some sort of integer conversion.
3629 * first, skip white space in buffer.
3630 */
3631 str = skip_spaces(str);
3632
3633 digit = *str;
3634 if (is_sign && digit == '-') {
3635 if (field_width == 1)
3636 break;
3637
3638 digit = *(str + 1);
3639 }
3640
3641 if (!digit
3642 || (base == 16 && !isxdigit(digit))
3643 || (base == 10 && !isdigit(digit))
3644 || (base == 8 && !isodigit(digit))
3645 || (base == 0 && !isdigit(digit)))
3646 break;
3647
3648 if (is_sign)
3649 val.s = simple_strntoll(str, &next, base,
3650 field_width >= 0 ? field_width : INT_MAX);
3651 else
3652 val.u = simple_strntoull(str, &next, base,
3653 field_width >= 0 ? field_width : INT_MAX);
3654
3655 switch (qualifier) {
3656 case 'H': /* that's 'hh' in format */
3657 if (is_sign)
3658 *va_arg(args, signed char *) = val.s;
3659 else
3660 *va_arg(args, unsigned char *) = val.u;
3661 break;
3662 case 'h':
3663 if (is_sign)
3664 *va_arg(args, short *) = val.s;
3665 else
3666 *va_arg(args, unsigned short *) = val.u;
3667 break;
3668 case 'l':
3669 if (is_sign)
3670 *va_arg(args, long *) = val.s;
3671 else
3672 *va_arg(args, unsigned long *) = val.u;
3673 break;
3674 case 'L':
3675 if (is_sign)
3676 *va_arg(args, long long *) = val.s;
3677 else
3678 *va_arg(args, unsigned long long *) = val.u;
3679 break;
3680 case 'z':
3681 *va_arg(args, size_t *) = val.u;
3682 break;
3683 default:
3684 if (is_sign)
3685 *va_arg(args, int *) = val.s;
3686 else
3687 *va_arg(args, unsigned int *) = val.u;
3688 break;
3689 }
3690 num++;
3691
3692 if (!next)
3693 break;
3694 str = next;
3695 }
3696
3697 return num;
3698 }
3699 EXPORT_SYMBOL(vsscanf);
3700
3701 /**
3702 * sscanf - Unformat a buffer into a list of arguments
3703 * @buf: input buffer
3704 * @fmt: formatting of buffer
3705 * @...: resulting arguments
3706 */
sscanf(const char * buf,const char * fmt,...)3707 int sscanf(const char *buf, const char *fmt, ...)
3708 {
3709 va_list args;
3710 int i;
3711
3712 va_start(args, fmt);
3713 i = vsscanf(buf, fmt, args);
3714 va_end(args);
3715
3716 return i;
3717 }
3718 EXPORT_SYMBOL(sscanf);
3719