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 #define special_hex_spec(size) \
586 (struct printf_spec) { \
587 .field_width = 2 + 2 * (size), /* 0x + hex */ \
588 .flags = SPECIAL | SMALL | ZEROPAD, \
589 .base = 16, \
590 .precision = -1, \
591 }
592
593 static noinline_for_stack
special_hex_number(char * buf,char * end,unsigned long long num,int size)594 char *special_hex_number(char *buf, char *end, unsigned long long num, int size)
595 {
596 return number(buf, end, num, special_hex_spec(size));
597 }
598
move_right(char * buf,char * end,unsigned len,unsigned spaces)599 static void move_right(char *buf, char *end, unsigned len, unsigned spaces)
600 {
601 size_t size;
602 if (buf >= end) /* nowhere to put anything */
603 return;
604 size = end - buf;
605 if (size <= spaces) {
606 memset(buf, ' ', size);
607 return;
608 }
609 if (len) {
610 if (len > size - spaces)
611 len = size - spaces;
612 memmove(buf + spaces, buf, len);
613 }
614 memset(buf, ' ', spaces);
615 }
616
617 /*
618 * Handle field width padding for a string.
619 * @buf: current buffer position
620 * @n: length of string
621 * @end: end of output buffer
622 * @spec: for field width and flags
623 * Returns: new buffer position after padding.
624 */
625 static noinline_for_stack
widen_string(char * buf,int n,char * end,struct printf_spec spec)626 char *widen_string(char *buf, int n, char *end, struct printf_spec spec)
627 {
628 unsigned spaces;
629
630 if (likely(n >= spec.field_width))
631 return buf;
632 /* we want to pad the sucker */
633 spaces = spec.field_width - n;
634 if (!(spec.flags & LEFT)) {
635 move_right(buf - n, end, n, spaces);
636 return buf + spaces;
637 }
638 while (spaces--) {
639 if (buf < end)
640 *buf = ' ';
641 ++buf;
642 }
643 return buf;
644 }
645
646 /* Handle string from a well known address. */
string_nocheck(char * buf,char * end,const char * s,struct printf_spec spec)647 static char *string_nocheck(char *buf, char *end, const char *s,
648 struct printf_spec spec)
649 {
650 int len = 0;
651 int lim = spec.precision;
652
653 while (lim--) {
654 char c = *s++;
655 if (!c)
656 break;
657 if (buf < end)
658 *buf = c;
659 ++buf;
660 ++len;
661 }
662 return widen_string(buf, len, end, spec);
663 }
664
err_ptr(char * buf,char * end,void * ptr,struct printf_spec spec)665 static char *err_ptr(char *buf, char *end, void *ptr,
666 struct printf_spec spec)
667 {
668 int err = PTR_ERR(ptr);
669 const char *sym = errname(err);
670
671 if (sym)
672 return string_nocheck(buf, end, sym, spec);
673
674 /*
675 * Somebody passed ERR_PTR(-1234) or some other non-existing
676 * Efoo - or perhaps CONFIG_SYMBOLIC_ERRNAME=n. Fall back to
677 * printing it as its decimal representation.
678 */
679 spec.flags |= SIGN;
680 spec.base = 10;
681 return number(buf, end, err, spec);
682 }
683
684 /* Be careful: error messages must fit into the given buffer. */
error_string(char * buf,char * end,const char * s,struct printf_spec spec)685 static char *error_string(char *buf, char *end, const char *s,
686 struct printf_spec spec)
687 {
688 /*
689 * Hard limit to avoid a completely insane messages. It actually
690 * works pretty well because most error messages are in
691 * the many pointer format modifiers.
692 */
693 if (spec.precision == -1)
694 spec.precision = 2 * sizeof(void *);
695
696 return string_nocheck(buf, end, s, spec);
697 }
698
699 /*
700 * Do not call any complex external code here. Nested printk()/vsprintf()
701 * might cause infinite loops. Failures might break printk() and would
702 * be hard to debug.
703 */
check_pointer_msg(const void * ptr)704 static const char *check_pointer_msg(const void *ptr)
705 {
706 if (!ptr)
707 return "(null)";
708
709 if ((unsigned long)ptr < PAGE_SIZE || IS_ERR_VALUE(ptr))
710 return "(efault)";
711
712 return NULL;
713 }
714
check_pointer(char ** buf,char * end,const void * ptr,struct printf_spec spec)715 static int check_pointer(char **buf, char *end, const void *ptr,
716 struct printf_spec spec)
717 {
718 const char *err_msg;
719
720 err_msg = check_pointer_msg(ptr);
721 if (err_msg) {
722 *buf = error_string(*buf, end, err_msg, spec);
723 return -EFAULT;
724 }
725
726 return 0;
727 }
728
729 static noinline_for_stack
string(char * buf,char * end,const char * s,struct printf_spec spec)730 char *string(char *buf, char *end, const char *s,
731 struct printf_spec spec)
732 {
733 if (check_pointer(&buf, end, s, spec))
734 return buf;
735
736 return string_nocheck(buf, end, s, spec);
737 }
738
pointer_string(char * buf,char * end,const void * ptr,struct printf_spec spec)739 static char *pointer_string(char *buf, char *end,
740 const void *ptr,
741 struct printf_spec spec)
742 {
743 spec.base = 16;
744 spec.flags |= SMALL;
745 if (spec.field_width == -1) {
746 spec.field_width = 2 * sizeof(ptr);
747 spec.flags |= ZEROPAD;
748 }
749
750 return number(buf, end, (unsigned long int)ptr, spec);
751 }
752
753 /* Make pointers available for printing early in the boot sequence. */
754 static int debug_boot_weak_hash __ro_after_init;
755
debug_boot_weak_hash_enable(char * str)756 static int __init debug_boot_weak_hash_enable(char *str)
757 {
758 debug_boot_weak_hash = 1;
759 pr_info("debug_boot_weak_hash enabled\n");
760 return 0;
761 }
762 early_param("debug_boot_weak_hash", debug_boot_weak_hash_enable);
763
764 static bool filled_random_ptr_key __read_mostly;
765 static siphash_key_t ptr_key __read_mostly;
766
fill_ptr_key(struct notifier_block * nb,unsigned long action,void * data)767 static int fill_ptr_key(struct notifier_block *nb, unsigned long action, void *data)
768 {
769 get_random_bytes(&ptr_key, sizeof(ptr_key));
770
771 /* Pairs with smp_rmb() before reading ptr_key. */
772 smp_wmb();
773 WRITE_ONCE(filled_random_ptr_key, true);
774 return NOTIFY_DONE;
775 }
776
vsprintf_init_hashval(void)777 static int __init vsprintf_init_hashval(void)
778 {
779 static struct notifier_block fill_ptr_key_nb = { .notifier_call = fill_ptr_key };
780 execute_with_initialized_rng(&fill_ptr_key_nb);
781 return 0;
782 }
subsys_initcall(vsprintf_init_hashval)783 subsys_initcall(vsprintf_init_hashval)
784
785 /* Maps a pointer to a 32 bit unique identifier. */
786 static inline int __ptr_to_hashval(const void *ptr, unsigned long *hashval_out)
787 {
788 unsigned long hashval;
789
790 if (!READ_ONCE(filled_random_ptr_key))
791 return -EBUSY;
792
793 /* Pairs with smp_wmb() after writing ptr_key. */
794 smp_rmb();
795
796 #ifdef CONFIG_64BIT
797 hashval = (unsigned long)siphash_1u64((u64)ptr, &ptr_key);
798 /*
799 * Mask off the first 32 bits, this makes explicit that we have
800 * modified the address (and 32 bits is plenty for a unique ID).
801 */
802 hashval = hashval & 0xffffffff;
803 #else
804 hashval = (unsigned long)siphash_1u32((u32)ptr, &ptr_key);
805 #endif
806 *hashval_out = hashval;
807 return 0;
808 }
809
ptr_to_hashval(const void * ptr,unsigned long * hashval_out)810 int ptr_to_hashval(const void *ptr, unsigned long *hashval_out)
811 {
812 return __ptr_to_hashval(ptr, hashval_out);
813 }
814
ptr_to_id(char * buf,char * end,const void * ptr,struct printf_spec spec)815 static char *ptr_to_id(char *buf, char *end, const void *ptr,
816 struct printf_spec spec)
817 {
818 const char *str = sizeof(ptr) == 8 ? "(____ptrval____)" : "(ptrval)";
819 unsigned long hashval;
820 int ret;
821
822 /*
823 * Print the real pointer value for NULL and error pointers,
824 * as they are not actual addresses.
825 */
826 if (IS_ERR_OR_NULL(ptr))
827 return pointer_string(buf, end, ptr, spec);
828
829 /* When debugging early boot use non-cryptographically secure hash. */
830 if (unlikely(debug_boot_weak_hash)) {
831 hashval = hash_long((unsigned long)ptr, 32);
832 return pointer_string(buf, end, (const void *)hashval, spec);
833 }
834
835 ret = __ptr_to_hashval(ptr, &hashval);
836 if (ret) {
837 spec.field_width = 2 * sizeof(ptr);
838 /* string length must be less than default_width */
839 return error_string(buf, end, str, spec);
840 }
841
842 return pointer_string(buf, end, (const void *)hashval, spec);
843 }
844
default_pointer(char * buf,char * end,const void * ptr,struct printf_spec spec)845 static char *default_pointer(char *buf, char *end, const void *ptr,
846 struct printf_spec spec)
847 {
848 /*
849 * default is to _not_ leak addresses, so hash before printing,
850 * unless no_hash_pointers is specified on the command line.
851 */
852 if (unlikely(no_hash_pointers))
853 return pointer_string(buf, end, ptr, spec);
854
855 return ptr_to_id(buf, end, ptr, spec);
856 }
857
858 int kptr_restrict __read_mostly;
859
860 static noinline_for_stack
restricted_pointer(char * buf,char * end,const void * ptr,struct printf_spec spec)861 char *restricted_pointer(char *buf, char *end, const void *ptr,
862 struct printf_spec spec)
863 {
864 switch (kptr_restrict) {
865 case 0:
866 /* Handle as %p, hash and do _not_ leak addresses. */
867 return default_pointer(buf, end, ptr, spec);
868 case 1: {
869 const struct cred *cred;
870
871 /*
872 * kptr_restrict==1 cannot be used in IRQ context
873 * because its test for CAP_SYSLOG would be meaningless.
874 */
875 if (in_hardirq() || in_serving_softirq() || in_nmi()) {
876 if (spec.field_width == -1)
877 spec.field_width = 2 * sizeof(ptr);
878 return error_string(buf, end, "pK-error", spec);
879 }
880
881 /*
882 * Only print the real pointer value if the current
883 * process has CAP_SYSLOG and is running with the
884 * same credentials it started with. This is because
885 * access to files is checked at open() time, but %pK
886 * checks permission at read() time. We don't want to
887 * leak pointer values if a binary opens a file using
888 * %pK and then elevates privileges before reading it.
889 */
890 cred = current_cred();
891 if (!has_capability_noaudit(current, CAP_SYSLOG) ||
892 !uid_eq(cred->euid, cred->uid) ||
893 !gid_eq(cred->egid, cred->gid))
894 ptr = NULL;
895 break;
896 }
897 case 2:
898 default:
899 /* Always print 0's for %pK */
900 ptr = NULL;
901 break;
902 }
903
904 return pointer_string(buf, end, ptr, spec);
905 }
906
907 static noinline_for_stack
dentry_name(char * buf,char * end,const struct dentry * d,struct printf_spec spec,const char * fmt)908 char *dentry_name(char *buf, char *end, const struct dentry *d, struct printf_spec spec,
909 const char *fmt)
910 {
911 const char *array[4], *s;
912 const struct dentry *p;
913 int depth;
914 int i, n;
915
916 switch (fmt[1]) {
917 case '2': case '3': case '4':
918 depth = fmt[1] - '0';
919 break;
920 default:
921 depth = 1;
922 }
923
924 rcu_read_lock();
925 for (i = 0; i < depth; i++, d = p) {
926 if (check_pointer(&buf, end, d, spec)) {
927 rcu_read_unlock();
928 return buf;
929 }
930
931 p = READ_ONCE(d->d_parent);
932 array[i] = READ_ONCE(d->d_name.name);
933 if (p == d) {
934 if (i)
935 array[i] = "";
936 i++;
937 break;
938 }
939 }
940 s = array[--i];
941 for (n = 0; n != spec.precision; n++, buf++) {
942 char c = *s++;
943 if (!c) {
944 if (!i)
945 break;
946 c = '/';
947 s = array[--i];
948 }
949 if (buf < end)
950 *buf = c;
951 }
952 rcu_read_unlock();
953 return widen_string(buf, n, end, spec);
954 }
955
956 static noinline_for_stack
file_dentry_name(char * buf,char * end,const struct file * f,struct printf_spec spec,const char * fmt)957 char *file_dentry_name(char *buf, char *end, const struct file *f,
958 struct printf_spec spec, const char *fmt)
959 {
960 if (check_pointer(&buf, end, f, spec))
961 return buf;
962
963 return dentry_name(buf, end, f->f_path.dentry, spec, fmt);
964 }
965 #ifdef CONFIG_BLOCK
966 static noinline_for_stack
bdev_name(char * buf,char * end,struct block_device * bdev,struct printf_spec spec,const char * fmt)967 char *bdev_name(char *buf, char *end, struct block_device *bdev,
968 struct printf_spec spec, const char *fmt)
969 {
970 struct gendisk *hd;
971
972 if (check_pointer(&buf, end, bdev, spec))
973 return buf;
974
975 hd = bdev->bd_disk;
976 buf = string(buf, end, hd->disk_name, spec);
977 if (bdev_is_partition(bdev)) {
978 if (isdigit(hd->disk_name[strlen(hd->disk_name)-1])) {
979 if (buf < end)
980 *buf = 'p';
981 buf++;
982 }
983 buf = number(buf, end, bdev_partno(bdev), spec);
984 }
985 return buf;
986 }
987 #endif
988
989 static noinline_for_stack
symbol_string(char * buf,char * end,void * ptr,struct printf_spec spec,const char * fmt)990 char *symbol_string(char *buf, char *end, void *ptr,
991 struct printf_spec spec, const char *fmt)
992 {
993 unsigned long value;
994 #ifdef CONFIG_KALLSYMS
995 char sym[KSYM_SYMBOL_LEN];
996 #endif
997
998 if (fmt[1] == 'R')
999 ptr = __builtin_extract_return_addr(ptr);
1000 value = (unsigned long)ptr;
1001
1002 #ifdef CONFIG_KALLSYMS
1003 if (*fmt == 'B' && fmt[1] == 'b')
1004 sprint_backtrace_build_id(sym, value);
1005 else if (*fmt == 'B')
1006 sprint_backtrace(sym, value);
1007 else if (*fmt == 'S' && (fmt[1] == 'b' || (fmt[1] == 'R' && fmt[2] == 'b')))
1008 sprint_symbol_build_id(sym, value);
1009 else if (*fmt != 's')
1010 sprint_symbol(sym, value);
1011 else
1012 sprint_symbol_no_offset(sym, value);
1013
1014 return string_nocheck(buf, end, sym, spec);
1015 #else
1016 return special_hex_number(buf, end, value, sizeof(void *));
1017 #endif
1018 }
1019
1020 static const struct printf_spec default_str_spec = {
1021 .field_width = -1,
1022 .precision = -1,
1023 };
1024
1025 static const struct printf_spec default_flag_spec = {
1026 .base = 16,
1027 .precision = -1,
1028 .flags = SPECIAL | SMALL,
1029 };
1030
1031 static const struct printf_spec default_dec_spec = {
1032 .base = 10,
1033 .precision = -1,
1034 };
1035
1036 static const struct printf_spec default_dec02_spec = {
1037 .base = 10,
1038 .field_width = 2,
1039 .precision = -1,
1040 .flags = ZEROPAD,
1041 };
1042
1043 static const struct printf_spec default_dec04_spec = {
1044 .base = 10,
1045 .field_width = 4,
1046 .precision = -1,
1047 .flags = ZEROPAD,
1048 };
1049
1050 static noinline_for_stack
hex_range(char * buf,char * end,u64 start_val,u64 end_val,struct printf_spec spec)1051 char *hex_range(char *buf, char *end, u64 start_val, u64 end_val,
1052 struct printf_spec spec)
1053 {
1054 buf = number(buf, end, start_val, spec);
1055 if (start_val == end_val)
1056 return buf;
1057
1058 if (buf < end)
1059 *buf = '-';
1060 ++buf;
1061 return number(buf, end, end_val, spec);
1062 }
1063
1064 static noinline_for_stack
resource_string(char * buf,char * end,struct resource * res,struct printf_spec spec,const char * fmt)1065 char *resource_string(char *buf, char *end, struct resource *res,
1066 struct printf_spec spec, const char *fmt)
1067 {
1068 #ifndef IO_RSRC_PRINTK_SIZE
1069 #define IO_RSRC_PRINTK_SIZE 6
1070 #endif
1071
1072 #ifndef MEM_RSRC_PRINTK_SIZE
1073 #define MEM_RSRC_PRINTK_SIZE 10
1074 #endif
1075 static const struct printf_spec io_spec = {
1076 .base = 16,
1077 .field_width = IO_RSRC_PRINTK_SIZE,
1078 .precision = -1,
1079 .flags = SPECIAL | SMALL | ZEROPAD,
1080 };
1081 static const struct printf_spec mem_spec = {
1082 .base = 16,
1083 .field_width = MEM_RSRC_PRINTK_SIZE,
1084 .precision = -1,
1085 .flags = SPECIAL | SMALL | ZEROPAD,
1086 };
1087 static const struct printf_spec bus_spec = {
1088 .base = 16,
1089 .field_width = 2,
1090 .precision = -1,
1091 .flags = SMALL | ZEROPAD,
1092 };
1093 static const struct printf_spec str_spec = {
1094 .field_width = -1,
1095 .precision = 10,
1096 .flags = LEFT,
1097 };
1098
1099 /* 32-bit res (sizeof==4): 10 chars in dec, 10 in hex ("0x" + 8)
1100 * 64-bit res (sizeof==8): 20 chars in dec, 18 in hex ("0x" + 16) */
1101 #define RSRC_BUF_SIZE ((2 * sizeof(resource_size_t)) + 4)
1102 #define FLAG_BUF_SIZE (2 * sizeof(res->flags))
1103 #define DECODED_BUF_SIZE sizeof("[mem - 64bit pref window disabled]")
1104 #define RAW_BUF_SIZE sizeof("[mem - flags 0x]")
1105 char sym[MAX(2*RSRC_BUF_SIZE + DECODED_BUF_SIZE,
1106 2*RSRC_BUF_SIZE + FLAG_BUF_SIZE + RAW_BUF_SIZE)];
1107
1108 char *p = sym, *pend = sym + sizeof(sym);
1109 int decode = (fmt[0] == 'R') ? 1 : 0;
1110 const struct printf_spec *specp;
1111
1112 if (check_pointer(&buf, end, res, spec))
1113 return buf;
1114
1115 *p++ = '[';
1116 if (res->flags & IORESOURCE_IO) {
1117 p = string_nocheck(p, pend, "io ", str_spec);
1118 specp = &io_spec;
1119 } else if (res->flags & IORESOURCE_MEM) {
1120 p = string_nocheck(p, pend, "mem ", str_spec);
1121 specp = &mem_spec;
1122 } else if (res->flags & IORESOURCE_IRQ) {
1123 p = string_nocheck(p, pend, "irq ", str_spec);
1124 specp = &default_dec_spec;
1125 } else if (res->flags & IORESOURCE_DMA) {
1126 p = string_nocheck(p, pend, "dma ", str_spec);
1127 specp = &default_dec_spec;
1128 } else if (res->flags & IORESOURCE_BUS) {
1129 p = string_nocheck(p, pend, "bus ", str_spec);
1130 specp = &bus_spec;
1131 } else {
1132 p = string_nocheck(p, pend, "??? ", str_spec);
1133 specp = &mem_spec;
1134 decode = 0;
1135 }
1136 if (decode && res->flags & IORESOURCE_UNSET) {
1137 p = string_nocheck(p, pend, "size ", str_spec);
1138 p = number(p, pend, resource_size(res), *specp);
1139 } else {
1140 p = hex_range(p, pend, res->start, res->end, *specp);
1141 }
1142 if (decode) {
1143 if (res->flags & IORESOURCE_MEM_64)
1144 p = string_nocheck(p, pend, " 64bit", str_spec);
1145 if (res->flags & IORESOURCE_PREFETCH)
1146 p = string_nocheck(p, pend, " pref", str_spec);
1147 if (res->flags & IORESOURCE_WINDOW)
1148 p = string_nocheck(p, pend, " window", str_spec);
1149 if (res->flags & IORESOURCE_DISABLED)
1150 p = string_nocheck(p, pend, " disabled", str_spec);
1151 } else {
1152 p = string_nocheck(p, pend, " flags ", str_spec);
1153 p = number(p, pend, res->flags, default_flag_spec);
1154 }
1155 *p++ = ']';
1156 *p = '\0';
1157
1158 return string_nocheck(buf, end, sym, spec);
1159 }
1160
1161 static noinline_for_stack
range_string(char * buf,char * end,const struct range * range,struct printf_spec spec,const char * fmt)1162 char *range_string(char *buf, char *end, const struct range *range,
1163 struct printf_spec spec, const char *fmt)
1164 {
1165 char sym[sizeof("[range 0x0123456789abcdef-0x0123456789abcdef]")];
1166 char *p = sym, *pend = sym + sizeof(sym);
1167
1168 if (check_pointer(&buf, end, range, spec))
1169 return buf;
1170
1171 p = string_nocheck(p, pend, "[range ", default_str_spec);
1172 p = hex_range(p, pend, range->start, range->end, special_hex_spec(sizeof(range->start)));
1173 *p++ = ']';
1174 *p = '\0';
1175
1176 return string_nocheck(buf, end, sym, spec);
1177 }
1178
1179 static noinline_for_stack
hex_string(char * buf,char * end,u8 * addr,struct printf_spec spec,const char * fmt)1180 char *hex_string(char *buf, char *end, u8 *addr, struct printf_spec spec,
1181 const char *fmt)
1182 {
1183 int i, len = 1; /* if we pass '%ph[CDN]', field width remains
1184 negative value, fallback to the default */
1185 char separator;
1186
1187 if (spec.field_width == 0)
1188 /* nothing to print */
1189 return buf;
1190
1191 if (check_pointer(&buf, end, addr, spec))
1192 return buf;
1193
1194 switch (fmt[1]) {
1195 case 'C':
1196 separator = ':';
1197 break;
1198 case 'D':
1199 separator = '-';
1200 break;
1201 case 'N':
1202 separator = 0;
1203 break;
1204 default:
1205 separator = ' ';
1206 break;
1207 }
1208
1209 if (spec.field_width > 0)
1210 len = min_t(int, spec.field_width, 64);
1211
1212 for (i = 0; i < len; ++i) {
1213 if (buf < end)
1214 *buf = hex_asc_hi(addr[i]);
1215 ++buf;
1216 if (buf < end)
1217 *buf = hex_asc_lo(addr[i]);
1218 ++buf;
1219
1220 if (separator && i != len - 1) {
1221 if (buf < end)
1222 *buf = separator;
1223 ++buf;
1224 }
1225 }
1226
1227 return buf;
1228 }
1229
1230 static noinline_for_stack
bitmap_string(char * buf,char * end,const unsigned long * bitmap,struct printf_spec spec,const char * fmt)1231 char *bitmap_string(char *buf, char *end, const unsigned long *bitmap,
1232 struct printf_spec spec, const char *fmt)
1233 {
1234 const int CHUNKSZ = 32;
1235 int nr_bits = max_t(int, spec.field_width, 0);
1236 int i, chunksz;
1237 bool first = true;
1238
1239 if (check_pointer(&buf, end, bitmap, spec))
1240 return buf;
1241
1242 /* reused to print numbers */
1243 spec = (struct printf_spec){ .flags = SMALL | ZEROPAD, .base = 16 };
1244
1245 chunksz = nr_bits & (CHUNKSZ - 1);
1246 if (chunksz == 0)
1247 chunksz = CHUNKSZ;
1248
1249 i = ALIGN(nr_bits, CHUNKSZ) - CHUNKSZ;
1250 for (; i >= 0; i -= CHUNKSZ) {
1251 u32 chunkmask, val;
1252 int word, bit;
1253
1254 chunkmask = ((1ULL << chunksz) - 1);
1255 word = i / BITS_PER_LONG;
1256 bit = i % BITS_PER_LONG;
1257 val = (bitmap[word] >> bit) & chunkmask;
1258
1259 if (!first) {
1260 if (buf < end)
1261 *buf = ',';
1262 buf++;
1263 }
1264 first = false;
1265
1266 spec.field_width = DIV_ROUND_UP(chunksz, 4);
1267 buf = number(buf, end, val, spec);
1268
1269 chunksz = CHUNKSZ;
1270 }
1271 return buf;
1272 }
1273
1274 static noinline_for_stack
bitmap_list_string(char * buf,char * end,const unsigned long * bitmap,struct printf_spec spec,const char * fmt)1275 char *bitmap_list_string(char *buf, char *end, const unsigned long *bitmap,
1276 struct printf_spec spec, const char *fmt)
1277 {
1278 int nr_bits = max_t(int, spec.field_width, 0);
1279 bool first = true;
1280 int rbot, rtop;
1281
1282 if (check_pointer(&buf, end, bitmap, spec))
1283 return buf;
1284
1285 for_each_set_bitrange(rbot, rtop, bitmap, nr_bits) {
1286 if (!first) {
1287 if (buf < end)
1288 *buf = ',';
1289 buf++;
1290 }
1291 first = false;
1292
1293 buf = number(buf, end, rbot, default_dec_spec);
1294 if (rtop == rbot + 1)
1295 continue;
1296
1297 if (buf < end)
1298 *buf = '-';
1299 buf = number(++buf, end, rtop - 1, default_dec_spec);
1300 }
1301 return buf;
1302 }
1303
1304 static noinline_for_stack
mac_address_string(char * buf,char * end,u8 * addr,struct printf_spec spec,const char * fmt)1305 char *mac_address_string(char *buf, char *end, u8 *addr,
1306 struct printf_spec spec, const char *fmt)
1307 {
1308 char mac_addr[sizeof("xx:xx:xx:xx:xx:xx")];
1309 char *p = mac_addr;
1310 int i;
1311 char separator;
1312 bool reversed = false;
1313
1314 if (check_pointer(&buf, end, addr, spec))
1315 return buf;
1316
1317 switch (fmt[1]) {
1318 case 'F':
1319 separator = '-';
1320 break;
1321
1322 case 'R':
1323 reversed = true;
1324 fallthrough;
1325
1326 default:
1327 separator = ':';
1328 break;
1329 }
1330
1331 for (i = 0; i < 6; i++) {
1332 if (reversed)
1333 p = hex_byte_pack(p, addr[5 - i]);
1334 else
1335 p = hex_byte_pack(p, addr[i]);
1336
1337 if (fmt[0] == 'M' && i != 5)
1338 *p++ = separator;
1339 }
1340 *p = '\0';
1341
1342 return string_nocheck(buf, end, mac_addr, spec);
1343 }
1344
1345 static noinline_for_stack
ip4_string(char * p,const u8 * addr,const char * fmt)1346 char *ip4_string(char *p, const u8 *addr, const char *fmt)
1347 {
1348 int i;
1349 bool leading_zeros = (fmt[0] == 'i');
1350 int index;
1351 int step;
1352
1353 switch (fmt[2]) {
1354 case 'h':
1355 #ifdef __BIG_ENDIAN
1356 index = 0;
1357 step = 1;
1358 #else
1359 index = 3;
1360 step = -1;
1361 #endif
1362 break;
1363 case 'l':
1364 index = 3;
1365 step = -1;
1366 break;
1367 case 'n':
1368 case 'b':
1369 default:
1370 index = 0;
1371 step = 1;
1372 break;
1373 }
1374 for (i = 0; i < 4; i++) {
1375 char temp[4] __aligned(2); /* hold each IP quad in reverse order */
1376 int digits = put_dec_trunc8(temp, addr[index]) - temp;
1377 if (leading_zeros) {
1378 if (digits < 3)
1379 *p++ = '0';
1380 if (digits < 2)
1381 *p++ = '0';
1382 }
1383 /* reverse the digits in the quad */
1384 while (digits--)
1385 *p++ = temp[digits];
1386 if (i < 3)
1387 *p++ = '.';
1388 index += step;
1389 }
1390 *p = '\0';
1391
1392 return p;
1393 }
1394
1395 static noinline_for_stack
ip6_compressed_string(char * p,const char * addr)1396 char *ip6_compressed_string(char *p, const char *addr)
1397 {
1398 int i, j, range;
1399 unsigned char zerolength[8];
1400 int longest = 1;
1401 int colonpos = -1;
1402 u16 word;
1403 u8 hi, lo;
1404 bool needcolon = false;
1405 bool useIPv4;
1406 struct in6_addr in6;
1407
1408 memcpy(&in6, addr, sizeof(struct in6_addr));
1409
1410 useIPv4 = ipv6_addr_v4mapped(&in6) || ipv6_addr_is_isatap(&in6);
1411
1412 memset(zerolength, 0, sizeof(zerolength));
1413
1414 if (useIPv4)
1415 range = 6;
1416 else
1417 range = 8;
1418
1419 /* find position of longest 0 run */
1420 for (i = 0; i < range; i++) {
1421 for (j = i; j < range; j++) {
1422 if (in6.s6_addr16[j] != 0)
1423 break;
1424 zerolength[i]++;
1425 }
1426 }
1427 for (i = 0; i < range; i++) {
1428 if (zerolength[i] > longest) {
1429 longest = zerolength[i];
1430 colonpos = i;
1431 }
1432 }
1433 if (longest == 1) /* don't compress a single 0 */
1434 colonpos = -1;
1435
1436 /* emit address */
1437 for (i = 0; i < range; i++) {
1438 if (i == colonpos) {
1439 if (needcolon || i == 0)
1440 *p++ = ':';
1441 *p++ = ':';
1442 needcolon = false;
1443 i += longest - 1;
1444 continue;
1445 }
1446 if (needcolon) {
1447 *p++ = ':';
1448 needcolon = false;
1449 }
1450 /* hex u16 without leading 0s */
1451 word = ntohs(in6.s6_addr16[i]);
1452 hi = word >> 8;
1453 lo = word & 0xff;
1454 if (hi) {
1455 if (hi > 0x0f)
1456 p = hex_byte_pack(p, hi);
1457 else
1458 *p++ = hex_asc_lo(hi);
1459 p = hex_byte_pack(p, lo);
1460 }
1461 else if (lo > 0x0f)
1462 p = hex_byte_pack(p, lo);
1463 else
1464 *p++ = hex_asc_lo(lo);
1465 needcolon = true;
1466 }
1467
1468 if (useIPv4) {
1469 if (needcolon)
1470 *p++ = ':';
1471 p = ip4_string(p, &in6.s6_addr[12], "I4");
1472 }
1473 *p = '\0';
1474
1475 return p;
1476 }
1477
1478 static noinline_for_stack
ip6_string(char * p,const char * addr,const char * fmt)1479 char *ip6_string(char *p, const char *addr, const char *fmt)
1480 {
1481 int i;
1482
1483 for (i = 0; i < 8; i++) {
1484 p = hex_byte_pack(p, *addr++);
1485 p = hex_byte_pack(p, *addr++);
1486 if (fmt[0] == 'I' && i != 7)
1487 *p++ = ':';
1488 }
1489 *p = '\0';
1490
1491 return p;
1492 }
1493
1494 static noinline_for_stack
ip6_addr_string(char * buf,char * end,const u8 * addr,struct printf_spec spec,const char * fmt)1495 char *ip6_addr_string(char *buf, char *end, const u8 *addr,
1496 struct printf_spec spec, const char *fmt)
1497 {
1498 char ip6_addr[sizeof("xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255")];
1499
1500 if (fmt[0] == 'I' && fmt[2] == 'c')
1501 ip6_compressed_string(ip6_addr, addr);
1502 else
1503 ip6_string(ip6_addr, addr, fmt);
1504
1505 return string_nocheck(buf, end, ip6_addr, spec);
1506 }
1507
1508 static noinline_for_stack
ip4_addr_string(char * buf,char * end,const u8 * addr,struct printf_spec spec,const char * fmt)1509 char *ip4_addr_string(char *buf, char *end, const u8 *addr,
1510 struct printf_spec spec, const char *fmt)
1511 {
1512 char ip4_addr[sizeof("255.255.255.255")];
1513
1514 ip4_string(ip4_addr, addr, fmt);
1515
1516 return string_nocheck(buf, end, ip4_addr, spec);
1517 }
1518
1519 static noinline_for_stack
ip6_addr_string_sa(char * buf,char * end,const struct sockaddr_in6 * sa,struct printf_spec spec,const char * fmt)1520 char *ip6_addr_string_sa(char *buf, char *end, const struct sockaddr_in6 *sa,
1521 struct printf_spec spec, const char *fmt)
1522 {
1523 bool have_p = false, have_s = false, have_f = false, have_c = false;
1524 char ip6_addr[sizeof("[xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255]") +
1525 sizeof(":12345") + sizeof("/123456789") +
1526 sizeof("%1234567890")];
1527 char *p = ip6_addr, *pend = ip6_addr + sizeof(ip6_addr);
1528 const u8 *addr = (const u8 *) &sa->sin6_addr;
1529 char fmt6[2] = { fmt[0], '6' };
1530 u8 off = 0;
1531
1532 fmt++;
1533 while (isalpha(*++fmt)) {
1534 switch (*fmt) {
1535 case 'p':
1536 have_p = true;
1537 break;
1538 case 'f':
1539 have_f = true;
1540 break;
1541 case 's':
1542 have_s = true;
1543 break;
1544 case 'c':
1545 have_c = true;
1546 break;
1547 }
1548 }
1549
1550 if (have_p || have_s || have_f) {
1551 *p = '[';
1552 off = 1;
1553 }
1554
1555 if (fmt6[0] == 'I' && have_c)
1556 p = ip6_compressed_string(ip6_addr + off, addr);
1557 else
1558 p = ip6_string(ip6_addr + off, addr, fmt6);
1559
1560 if (have_p || have_s || have_f)
1561 *p++ = ']';
1562
1563 if (have_p) {
1564 *p++ = ':';
1565 p = number(p, pend, ntohs(sa->sin6_port), spec);
1566 }
1567 if (have_f) {
1568 *p++ = '/';
1569 p = number(p, pend, ntohl(sa->sin6_flowinfo &
1570 IPV6_FLOWINFO_MASK), spec);
1571 }
1572 if (have_s) {
1573 *p++ = '%';
1574 p = number(p, pend, sa->sin6_scope_id, spec);
1575 }
1576 *p = '\0';
1577
1578 return string_nocheck(buf, end, ip6_addr, spec);
1579 }
1580
1581 static noinline_for_stack
ip4_addr_string_sa(char * buf,char * end,const struct sockaddr_in * sa,struct printf_spec spec,const char * fmt)1582 char *ip4_addr_string_sa(char *buf, char *end, const struct sockaddr_in *sa,
1583 struct printf_spec spec, const char *fmt)
1584 {
1585 bool have_p = false;
1586 char *p, ip4_addr[sizeof("255.255.255.255") + sizeof(":12345")];
1587 char *pend = ip4_addr + sizeof(ip4_addr);
1588 const u8 *addr = (const u8 *) &sa->sin_addr.s_addr;
1589 char fmt4[3] = { fmt[0], '4', 0 };
1590
1591 fmt++;
1592 while (isalpha(*++fmt)) {
1593 switch (*fmt) {
1594 case 'p':
1595 have_p = true;
1596 break;
1597 case 'h':
1598 case 'l':
1599 case 'n':
1600 case 'b':
1601 fmt4[2] = *fmt;
1602 break;
1603 }
1604 }
1605
1606 p = ip4_string(ip4_addr, addr, fmt4);
1607 if (have_p) {
1608 *p++ = ':';
1609 p = number(p, pend, ntohs(sa->sin_port), spec);
1610 }
1611 *p = '\0';
1612
1613 return string_nocheck(buf, end, ip4_addr, spec);
1614 }
1615
1616 static noinline_for_stack
ip_addr_string(char * buf,char * end,const void * ptr,struct printf_spec spec,const char * fmt)1617 char *ip_addr_string(char *buf, char *end, const void *ptr,
1618 struct printf_spec spec, const char *fmt)
1619 {
1620 char *err_fmt_msg;
1621
1622 if (check_pointer(&buf, end, ptr, spec))
1623 return buf;
1624
1625 switch (fmt[1]) {
1626 case '6':
1627 return ip6_addr_string(buf, end, ptr, spec, fmt);
1628 case '4':
1629 return ip4_addr_string(buf, end, ptr, spec, fmt);
1630 case 'S': {
1631 const union {
1632 struct sockaddr raw;
1633 struct sockaddr_in v4;
1634 struct sockaddr_in6 v6;
1635 } *sa = ptr;
1636
1637 switch (sa->raw.sa_family) {
1638 case AF_INET:
1639 return ip4_addr_string_sa(buf, end, &sa->v4, spec, fmt);
1640 case AF_INET6:
1641 return ip6_addr_string_sa(buf, end, &sa->v6, spec, fmt);
1642 default:
1643 return error_string(buf, end, "(einval)", spec);
1644 }}
1645 }
1646
1647 err_fmt_msg = fmt[0] == 'i' ? "(%pi?)" : "(%pI?)";
1648 return error_string(buf, end, err_fmt_msg, spec);
1649 }
1650
1651 static noinline_for_stack
escaped_string(char * buf,char * end,u8 * addr,struct printf_spec spec,const char * fmt)1652 char *escaped_string(char *buf, char *end, u8 *addr, struct printf_spec spec,
1653 const char *fmt)
1654 {
1655 bool found = true;
1656 int count = 1;
1657 unsigned int flags = 0;
1658 int len;
1659
1660 if (spec.field_width == 0)
1661 return buf; /* nothing to print */
1662
1663 if (check_pointer(&buf, end, addr, spec))
1664 return buf;
1665
1666 do {
1667 switch (fmt[count++]) {
1668 case 'a':
1669 flags |= ESCAPE_ANY;
1670 break;
1671 case 'c':
1672 flags |= ESCAPE_SPECIAL;
1673 break;
1674 case 'h':
1675 flags |= ESCAPE_HEX;
1676 break;
1677 case 'n':
1678 flags |= ESCAPE_NULL;
1679 break;
1680 case 'o':
1681 flags |= ESCAPE_OCTAL;
1682 break;
1683 case 'p':
1684 flags |= ESCAPE_NP;
1685 break;
1686 case 's':
1687 flags |= ESCAPE_SPACE;
1688 break;
1689 default:
1690 found = false;
1691 break;
1692 }
1693 } while (found);
1694
1695 if (!flags)
1696 flags = ESCAPE_ANY_NP;
1697
1698 len = spec.field_width < 0 ? 1 : spec.field_width;
1699
1700 /*
1701 * string_escape_mem() writes as many characters as it can to
1702 * the given buffer, and returns the total size of the output
1703 * had the buffer been big enough.
1704 */
1705 buf += string_escape_mem(addr, len, buf, buf < end ? end - buf : 0, flags, NULL);
1706
1707 return buf;
1708 }
1709
1710 __diag_push();
1711 __diag_ignore(GCC, all, "-Wsuggest-attribute=format",
1712 "Not a valid __printf() conversion candidate.");
va_format(char * buf,char * end,struct va_format * va_fmt,struct printf_spec spec)1713 static char *va_format(char *buf, char *end, struct va_format *va_fmt,
1714 struct printf_spec spec)
1715 {
1716 va_list va;
1717
1718 if (check_pointer(&buf, end, va_fmt, spec))
1719 return buf;
1720
1721 va_copy(va, *va_fmt->va);
1722 buf += vsnprintf(buf, end > buf ? end - buf : 0, va_fmt->fmt, va);
1723 va_end(va);
1724
1725 return buf;
1726 }
1727 __diag_pop();
1728
1729 static noinline_for_stack
uuid_string(char * buf,char * end,const u8 * addr,struct printf_spec spec,const char * fmt)1730 char *uuid_string(char *buf, char *end, const u8 *addr,
1731 struct printf_spec spec, const char *fmt)
1732 {
1733 char uuid[UUID_STRING_LEN + 1];
1734 char *p = uuid;
1735 int i;
1736 const u8 *index = uuid_index;
1737 bool uc = false;
1738
1739 if (check_pointer(&buf, end, addr, spec))
1740 return buf;
1741
1742 switch (*(++fmt)) {
1743 case 'L':
1744 uc = true;
1745 fallthrough;
1746 case 'l':
1747 index = guid_index;
1748 break;
1749 case 'B':
1750 uc = true;
1751 break;
1752 }
1753
1754 for (i = 0; i < 16; i++) {
1755 if (uc)
1756 p = hex_byte_pack_upper(p, addr[index[i]]);
1757 else
1758 p = hex_byte_pack(p, addr[index[i]]);
1759 switch (i) {
1760 case 3:
1761 case 5:
1762 case 7:
1763 case 9:
1764 *p++ = '-';
1765 break;
1766 }
1767 }
1768
1769 *p = 0;
1770
1771 return string_nocheck(buf, end, uuid, spec);
1772 }
1773
1774 static noinline_for_stack
netdev_bits(char * buf,char * end,const void * addr,struct printf_spec spec,const char * fmt)1775 char *netdev_bits(char *buf, char *end, const void *addr,
1776 struct printf_spec spec, const char *fmt)
1777 {
1778 unsigned long long num;
1779 int size;
1780
1781 if (check_pointer(&buf, end, addr, spec))
1782 return buf;
1783
1784 switch (fmt[1]) {
1785 case 'F':
1786 num = *(const netdev_features_t *)addr;
1787 size = sizeof(netdev_features_t);
1788 break;
1789 default:
1790 return error_string(buf, end, "(%pN?)", spec);
1791 }
1792
1793 return special_hex_number(buf, end, num, size);
1794 }
1795
1796 static noinline_for_stack
fourcc_string(char * buf,char * end,const u32 * fourcc,struct printf_spec spec,const char * fmt)1797 char *fourcc_string(char *buf, char *end, const u32 *fourcc,
1798 struct printf_spec spec, const char *fmt)
1799 {
1800 char output[sizeof("0123 little-endian (0x01234567)")];
1801 char *p = output;
1802 unsigned int i;
1803 bool pixel_fmt = false;
1804 u32 orig, val;
1805
1806 if (fmt[1] != 'c')
1807 return error_string(buf, end, "(%p4?)", spec);
1808
1809 if (check_pointer(&buf, end, fourcc, spec))
1810 return buf;
1811
1812 orig = get_unaligned(fourcc);
1813 switch (fmt[2]) {
1814 case 'h':
1815 if (fmt[3] == 'R')
1816 orig = swab32(orig);
1817 break;
1818 case 'l':
1819 orig = (__force u32)cpu_to_le32(orig);
1820 break;
1821 case 'b':
1822 orig = (__force u32)cpu_to_be32(orig);
1823 break;
1824 case 'c':
1825 /* Pixel formats are printed LSB-first */
1826 pixel_fmt = true;
1827 break;
1828 default:
1829 return error_string(buf, end, "(%p4?)", spec);
1830 }
1831
1832 val = pixel_fmt ? swab32(orig & ~BIT(31)) : orig;
1833
1834 for (i = 0; i < sizeof(u32); i++) {
1835 unsigned char c = val >> ((3 - i) * 8);
1836
1837 /* Print non-control ASCII characters as-is, dot otherwise */
1838 *p++ = isascii(c) && isprint(c) ? c : '.';
1839 }
1840
1841 if (pixel_fmt) {
1842 *p++ = ' ';
1843 strcpy(p, orig & BIT(31) ? "big-endian" : "little-endian");
1844 p += strlen(p);
1845 }
1846
1847 *p++ = ' ';
1848 *p++ = '(';
1849 p = special_hex_number(p, output + sizeof(output) - 2, orig, sizeof(u32));
1850 *p++ = ')';
1851 *p = '\0';
1852
1853 return string(buf, end, output, spec);
1854 }
1855
1856 static noinline_for_stack
address_val(char * buf,char * end,const void * addr,struct printf_spec spec,const char * fmt)1857 char *address_val(char *buf, char *end, const void *addr,
1858 struct printf_spec spec, const char *fmt)
1859 {
1860 unsigned long long num;
1861 int size;
1862
1863 if (check_pointer(&buf, end, addr, spec))
1864 return buf;
1865
1866 switch (fmt[1]) {
1867 case 'd':
1868 num = *(const dma_addr_t *)addr;
1869 size = sizeof(dma_addr_t);
1870 break;
1871 case 'p':
1872 default:
1873 num = *(const phys_addr_t *)addr;
1874 size = sizeof(phys_addr_t);
1875 break;
1876 }
1877
1878 return special_hex_number(buf, end, num, size);
1879 }
1880
1881 static noinline_for_stack
date_str(char * buf,char * end,const struct rtc_time * tm,bool r)1882 char *date_str(char *buf, char *end, const struct rtc_time *tm, bool r)
1883 {
1884 int year = tm->tm_year + (r ? 0 : 1900);
1885 int mon = tm->tm_mon + (r ? 0 : 1);
1886
1887 buf = number(buf, end, year, default_dec04_spec);
1888 if (buf < end)
1889 *buf = '-';
1890 buf++;
1891
1892 buf = number(buf, end, mon, default_dec02_spec);
1893 if (buf < end)
1894 *buf = '-';
1895 buf++;
1896
1897 return number(buf, end, tm->tm_mday, default_dec02_spec);
1898 }
1899
1900 static noinline_for_stack
time_str(char * buf,char * end,const struct rtc_time * tm,bool r)1901 char *time_str(char *buf, char *end, const struct rtc_time *tm, bool r)
1902 {
1903 buf = number(buf, end, tm->tm_hour, default_dec02_spec);
1904 if (buf < end)
1905 *buf = ':';
1906 buf++;
1907
1908 buf = number(buf, end, tm->tm_min, default_dec02_spec);
1909 if (buf < end)
1910 *buf = ':';
1911 buf++;
1912
1913 return number(buf, end, tm->tm_sec, default_dec02_spec);
1914 }
1915
1916 static noinline_for_stack
rtc_str(char * buf,char * end,const struct rtc_time * tm,struct printf_spec spec,const char * fmt)1917 char *rtc_str(char *buf, char *end, const struct rtc_time *tm,
1918 struct printf_spec spec, const char *fmt)
1919 {
1920 bool have_t = true, have_d = true;
1921 bool raw = false, iso8601_separator = true;
1922 bool found = true;
1923 int count = 2;
1924
1925 switch (fmt[count]) {
1926 case 'd':
1927 have_t = false;
1928 count++;
1929 break;
1930 case 't':
1931 have_d = false;
1932 count++;
1933 break;
1934 }
1935
1936 do {
1937 switch (fmt[count++]) {
1938 case 'r':
1939 raw = true;
1940 break;
1941 case 's':
1942 iso8601_separator = false;
1943 break;
1944 default:
1945 found = false;
1946 break;
1947 }
1948 } while (found);
1949
1950 if (have_d)
1951 buf = date_str(buf, end, tm, raw);
1952 if (have_d && have_t) {
1953 if (buf < end)
1954 *buf = iso8601_separator ? 'T' : ' ';
1955 buf++;
1956 }
1957 if (have_t)
1958 buf = time_str(buf, end, tm, raw);
1959
1960 return buf;
1961 }
1962
1963 static noinline_for_stack
time64_str(char * buf,char * end,const time64_t time,struct printf_spec spec,const char * fmt)1964 char *time64_str(char *buf, char *end, const time64_t time,
1965 struct printf_spec spec, const char *fmt)
1966 {
1967 struct rtc_time rtc_time;
1968 struct tm tm;
1969
1970 time64_to_tm(time, 0, &tm);
1971
1972 rtc_time.tm_sec = tm.tm_sec;
1973 rtc_time.tm_min = tm.tm_min;
1974 rtc_time.tm_hour = tm.tm_hour;
1975 rtc_time.tm_mday = tm.tm_mday;
1976 rtc_time.tm_mon = tm.tm_mon;
1977 rtc_time.tm_year = tm.tm_year;
1978 rtc_time.tm_wday = tm.tm_wday;
1979 rtc_time.tm_yday = tm.tm_yday;
1980
1981 rtc_time.tm_isdst = 0;
1982
1983 return rtc_str(buf, end, &rtc_time, spec, fmt);
1984 }
1985
1986 static noinline_for_stack
timespec64_str(char * buf,char * end,const struct timespec64 * ts,struct printf_spec spec,const char * fmt)1987 char *timespec64_str(char *buf, char *end, const struct timespec64 *ts,
1988 struct printf_spec spec, const char *fmt)
1989 {
1990 static const struct printf_spec default_dec09_spec = {
1991 .base = 10,
1992 .field_width = 9,
1993 .precision = -1,
1994 .flags = ZEROPAD,
1995 };
1996
1997 if (fmt[2] == 'p')
1998 buf = number(buf, end, ts->tv_sec, default_dec_spec);
1999 else
2000 buf = time64_str(buf, end, ts->tv_sec, spec, fmt);
2001 if (buf < end)
2002 *buf = '.';
2003 buf++;
2004
2005 return number(buf, end, ts->tv_nsec, default_dec09_spec);
2006 }
2007
2008 static noinline_for_stack
time_and_date(char * buf,char * end,void * ptr,struct printf_spec spec,const char * fmt)2009 char *time_and_date(char *buf, char *end, void *ptr, struct printf_spec spec,
2010 const char *fmt)
2011 {
2012 if (check_pointer(&buf, end, ptr, spec))
2013 return buf;
2014
2015 switch (fmt[1]) {
2016 case 'R':
2017 return rtc_str(buf, end, (const struct rtc_time *)ptr, spec, fmt);
2018 case 'S':
2019 return timespec64_str(buf, end, (const struct timespec64 *)ptr, spec, fmt);
2020 case 'T':
2021 return time64_str(buf, end, *(const time64_t *)ptr, spec, fmt);
2022 default:
2023 return error_string(buf, end, "(%pt?)", spec);
2024 }
2025 }
2026
2027 static noinline_for_stack
clock(char * buf,char * end,struct clk * clk,struct printf_spec spec,const char * fmt)2028 char *clock(char *buf, char *end, struct clk *clk, struct printf_spec spec,
2029 const char *fmt)
2030 {
2031 if (!IS_ENABLED(CONFIG_HAVE_CLK))
2032 return error_string(buf, end, "(%pC?)", spec);
2033
2034 if (check_pointer(&buf, end, clk, spec))
2035 return buf;
2036
2037 #ifdef CONFIG_COMMON_CLK
2038 return string(buf, end, __clk_get_name(clk), spec);
2039 #else
2040 return ptr_to_id(buf, end, clk, spec);
2041 #endif
2042 }
2043
2044 static
format_flags(char * buf,char * end,unsigned long flags,const struct trace_print_flags * names)2045 char *format_flags(char *buf, char *end, unsigned long flags,
2046 const struct trace_print_flags *names)
2047 {
2048 unsigned long mask;
2049
2050 for ( ; flags && names->name; names++) {
2051 mask = names->mask;
2052 if ((flags & mask) != mask)
2053 continue;
2054
2055 buf = string(buf, end, names->name, default_str_spec);
2056
2057 flags &= ~mask;
2058 if (flags) {
2059 if (buf < end)
2060 *buf = '|';
2061 buf++;
2062 }
2063 }
2064
2065 if (flags)
2066 buf = number(buf, end, flags, default_flag_spec);
2067
2068 return buf;
2069 }
2070
2071 struct page_flags_fields {
2072 int width;
2073 int shift;
2074 int mask;
2075 const struct printf_spec *spec;
2076 const char *name;
2077 };
2078
2079 static const struct page_flags_fields pff[] = {
2080 {SECTIONS_WIDTH, SECTIONS_PGSHIFT, SECTIONS_MASK,
2081 &default_dec_spec, "section"},
2082 {NODES_WIDTH, NODES_PGSHIFT, NODES_MASK,
2083 &default_dec_spec, "node"},
2084 {ZONES_WIDTH, ZONES_PGSHIFT, ZONES_MASK,
2085 &default_dec_spec, "zone"},
2086 {LAST_CPUPID_WIDTH, LAST_CPUPID_PGSHIFT, LAST_CPUPID_MASK,
2087 &default_flag_spec, "lastcpupid"},
2088 {KASAN_TAG_WIDTH, KASAN_TAG_PGSHIFT, KASAN_TAG_MASK,
2089 &default_flag_spec, "kasantag"},
2090 };
2091
2092 static
format_page_flags(char * buf,char * end,unsigned long flags)2093 char *format_page_flags(char *buf, char *end, unsigned long flags)
2094 {
2095 unsigned long main_flags = flags & PAGEFLAGS_MASK;
2096 bool append = false;
2097 int i;
2098
2099 buf = number(buf, end, flags, default_flag_spec);
2100 if (buf < end)
2101 *buf = '(';
2102 buf++;
2103
2104 /* Page flags from the main area. */
2105 if (main_flags) {
2106 buf = format_flags(buf, end, main_flags, pageflag_names);
2107 append = true;
2108 }
2109
2110 /* Page flags from the fields area */
2111 for (i = 0; i < ARRAY_SIZE(pff); i++) {
2112 /* Skip undefined fields. */
2113 if (!pff[i].width)
2114 continue;
2115
2116 /* Format: Flag Name + '=' (equals sign) + Number + '|' (separator) */
2117 if (append) {
2118 if (buf < end)
2119 *buf = '|';
2120 buf++;
2121 }
2122
2123 buf = string(buf, end, pff[i].name, default_str_spec);
2124 if (buf < end)
2125 *buf = '=';
2126 buf++;
2127 buf = number(buf, end, (flags >> pff[i].shift) & pff[i].mask,
2128 *pff[i].spec);
2129
2130 append = true;
2131 }
2132 if (buf < end)
2133 *buf = ')';
2134 buf++;
2135
2136 return buf;
2137 }
2138
2139 static noinline_for_stack
flags_string(char * buf,char * end,void * flags_ptr,struct printf_spec spec,const char * fmt)2140 char *flags_string(char *buf, char *end, void *flags_ptr,
2141 struct printf_spec spec, const char *fmt)
2142 {
2143 unsigned long flags;
2144 const struct trace_print_flags *names;
2145
2146 if (check_pointer(&buf, end, flags_ptr, spec))
2147 return buf;
2148
2149 switch (fmt[1]) {
2150 case 'p':
2151 return format_page_flags(buf, end, *(unsigned long *)flags_ptr);
2152 case 'v':
2153 flags = *(unsigned long *)flags_ptr;
2154 names = vmaflag_names;
2155 break;
2156 case 'g':
2157 flags = (__force unsigned long)(*(gfp_t *)flags_ptr);
2158 names = gfpflag_names;
2159 break;
2160 default:
2161 return error_string(buf, end, "(%pG?)", spec);
2162 }
2163
2164 return format_flags(buf, end, flags, names);
2165 }
2166
2167 static noinline_for_stack
fwnode_full_name_string(struct fwnode_handle * fwnode,char * buf,char * end)2168 char *fwnode_full_name_string(struct fwnode_handle *fwnode, char *buf,
2169 char *end)
2170 {
2171 int depth;
2172
2173 /* Loop starting from the root node to the current node. */
2174 for (depth = fwnode_count_parents(fwnode); depth >= 0; depth--) {
2175 /*
2176 * Only get a reference for other nodes (i.e. parent nodes).
2177 * fwnode refcount may be 0 here.
2178 */
2179 struct fwnode_handle *__fwnode = depth ?
2180 fwnode_get_nth_parent(fwnode, depth) : fwnode;
2181
2182 buf = string(buf, end, fwnode_get_name_prefix(__fwnode),
2183 default_str_spec);
2184 buf = string(buf, end, fwnode_get_name(__fwnode),
2185 default_str_spec);
2186
2187 if (depth)
2188 fwnode_handle_put(__fwnode);
2189 }
2190
2191 return buf;
2192 }
2193
2194 static noinline_for_stack
device_node_string(char * buf,char * end,struct device_node * dn,struct printf_spec spec,const char * fmt)2195 char *device_node_string(char *buf, char *end, struct device_node *dn,
2196 struct printf_spec spec, const char *fmt)
2197 {
2198 char tbuf[sizeof("xxxx") + 1];
2199 const char *p;
2200 int ret;
2201 char *buf_start = buf;
2202 struct property *prop;
2203 bool has_mult, pass;
2204
2205 struct printf_spec str_spec = spec;
2206 str_spec.field_width = -1;
2207
2208 if (fmt[0] != 'F')
2209 return error_string(buf, end, "(%pO?)", spec);
2210
2211 if (!IS_ENABLED(CONFIG_OF))
2212 return error_string(buf, end, "(%pOF?)", spec);
2213
2214 if (check_pointer(&buf, end, dn, spec))
2215 return buf;
2216
2217 /* simple case without anything any more format specifiers */
2218 fmt++;
2219 if (fmt[0] == '\0' || strcspn(fmt,"fnpPFcC") > 0)
2220 fmt = "f";
2221
2222 for (pass = false; strspn(fmt,"fnpPFcC"); fmt++, pass = true) {
2223 int precision;
2224 if (pass) {
2225 if (buf < end)
2226 *buf = ':';
2227 buf++;
2228 }
2229
2230 switch (*fmt) {
2231 case 'f': /* full_name */
2232 buf = fwnode_full_name_string(of_fwnode_handle(dn), buf,
2233 end);
2234 break;
2235 case 'n': /* name */
2236 p = fwnode_get_name(of_fwnode_handle(dn));
2237 precision = str_spec.precision;
2238 str_spec.precision = strchrnul(p, '@') - p;
2239 buf = string(buf, end, p, str_spec);
2240 str_spec.precision = precision;
2241 break;
2242 case 'p': /* phandle */
2243 buf = number(buf, end, (unsigned int)dn->phandle, default_dec_spec);
2244 break;
2245 case 'P': /* path-spec */
2246 p = fwnode_get_name(of_fwnode_handle(dn));
2247 if (!p[1])
2248 p = "/";
2249 buf = string(buf, end, p, str_spec);
2250 break;
2251 case 'F': /* flags */
2252 tbuf[0] = of_node_check_flag(dn, OF_DYNAMIC) ? 'D' : '-';
2253 tbuf[1] = of_node_check_flag(dn, OF_DETACHED) ? 'd' : '-';
2254 tbuf[2] = of_node_check_flag(dn, OF_POPULATED) ? 'P' : '-';
2255 tbuf[3] = of_node_check_flag(dn, OF_POPULATED_BUS) ? 'B' : '-';
2256 tbuf[4] = 0;
2257 buf = string_nocheck(buf, end, tbuf, str_spec);
2258 break;
2259 case 'c': /* major compatible string */
2260 ret = of_property_read_string(dn, "compatible", &p);
2261 if (!ret)
2262 buf = string(buf, end, p, str_spec);
2263 break;
2264 case 'C': /* full compatible string */
2265 has_mult = false;
2266 of_property_for_each_string(dn, "compatible", prop, p) {
2267 if (has_mult)
2268 buf = string_nocheck(buf, end, ",", str_spec);
2269 buf = string_nocheck(buf, end, "\"", str_spec);
2270 buf = string(buf, end, p, str_spec);
2271 buf = string_nocheck(buf, end, "\"", str_spec);
2272
2273 has_mult = true;
2274 }
2275 break;
2276 default:
2277 break;
2278 }
2279 }
2280
2281 return widen_string(buf, buf - buf_start, end, spec);
2282 }
2283
2284 static noinline_for_stack
fwnode_string(char * buf,char * end,struct fwnode_handle * fwnode,struct printf_spec spec,const char * fmt)2285 char *fwnode_string(char *buf, char *end, struct fwnode_handle *fwnode,
2286 struct printf_spec spec, const char *fmt)
2287 {
2288 struct printf_spec str_spec = spec;
2289 char *buf_start = buf;
2290
2291 str_spec.field_width = -1;
2292
2293 if (*fmt != 'w')
2294 return error_string(buf, end, "(%pf?)", spec);
2295
2296 if (check_pointer(&buf, end, fwnode, spec))
2297 return buf;
2298
2299 fmt++;
2300
2301 switch (*fmt) {
2302 case 'P': /* name */
2303 buf = string(buf, end, fwnode_get_name(fwnode), str_spec);
2304 break;
2305 case 'f': /* full_name */
2306 default:
2307 buf = fwnode_full_name_string(fwnode, buf, end);
2308 break;
2309 }
2310
2311 return widen_string(buf, buf - buf_start, end, spec);
2312 }
2313
2314 static noinline_for_stack
resource_or_range(const char * fmt,char * buf,char * end,void * ptr,struct printf_spec spec)2315 char *resource_or_range(const char *fmt, char *buf, char *end, void *ptr,
2316 struct printf_spec spec)
2317 {
2318 if (*fmt == 'r' && fmt[1] == 'a')
2319 return range_string(buf, end, ptr, spec, fmt);
2320 return resource_string(buf, end, ptr, spec, fmt);
2321 }
2322
hash_pointers_finalize(bool slub_debug)2323 void __init hash_pointers_finalize(bool slub_debug)
2324 {
2325 switch (hash_pointers_mode) {
2326 case HASH_PTR_ALWAYS:
2327 no_hash_pointers = false;
2328 break;
2329 case HASH_PTR_NEVER:
2330 no_hash_pointers = true;
2331 break;
2332 case HASH_PTR_AUTO:
2333 default:
2334 no_hash_pointers = slub_debug;
2335 break;
2336 }
2337
2338 if (!no_hash_pointers)
2339 return;
2340
2341 pr_warn("**********************************************************\n");
2342 pr_warn("** NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE **\n");
2343 pr_warn("** **\n");
2344 pr_warn("** This system shows unhashed kernel memory addresses **\n");
2345 pr_warn("** via the console, logs, and other interfaces. This **\n");
2346 pr_warn("** might reduce the security of your system. **\n");
2347 pr_warn("** **\n");
2348 pr_warn("** If you see this message and you are not debugging **\n");
2349 pr_warn("** the kernel, report this immediately to your system **\n");
2350 pr_warn("** administrator! **\n");
2351 pr_warn("** **\n");
2352 pr_warn("** Use hash_pointers=always to force this mode off **\n");
2353 pr_warn("** **\n");
2354 pr_warn("** NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE **\n");
2355 pr_warn("**********************************************************\n");
2356 }
2357
hash_pointers_mode_parse(char * str)2358 static int __init hash_pointers_mode_parse(char *str)
2359 {
2360 if (!str) {
2361 pr_warn("Hash pointers mode empty; falling back to auto.\n");
2362 hash_pointers_mode = HASH_PTR_AUTO;
2363 } else if (strncmp(str, "auto", 4) == 0) {
2364 pr_info("Hash pointers mode set to auto.\n");
2365 hash_pointers_mode = HASH_PTR_AUTO;
2366 } else if (strncmp(str, "never", 5) == 0) {
2367 pr_info("Hash pointers mode set to never.\n");
2368 hash_pointers_mode = HASH_PTR_NEVER;
2369 } else if (strncmp(str, "always", 6) == 0) {
2370 pr_info("Hash pointers mode set to always.\n");
2371 hash_pointers_mode = HASH_PTR_ALWAYS;
2372 } else {
2373 pr_warn("Unknown hash_pointers mode '%s' specified; assuming auto.\n", str);
2374 hash_pointers_mode = HASH_PTR_AUTO;
2375 }
2376
2377 return 0;
2378 }
2379 early_param("hash_pointers", hash_pointers_mode_parse);
2380
no_hash_pointers_enable(char * str)2381 static int __init no_hash_pointers_enable(char *str)
2382 {
2383 return hash_pointers_mode_parse("never");
2384 }
2385 early_param("no_hash_pointers", no_hash_pointers_enable);
2386
2387 /*
2388 * Show a '%p' thing. A kernel extension is that the '%p' is followed
2389 * by an extra set of alphanumeric characters that are extended format
2390 * specifiers.
2391 *
2392 * Please update scripts/checkpatch.pl when adding/removing conversion
2393 * characters. (Search for "check for vsprintf extension").
2394 *
2395 * Right now we handle:
2396 *
2397 * - 'S' For symbolic direct pointers (or function descriptors) with offset
2398 * - 's' For symbolic direct pointers (or function descriptors) without offset
2399 * - '[Ss]R' as above with __builtin_extract_return_addr() translation
2400 * - 'S[R]b' as above with module build ID (for use in backtraces)
2401 * - '[Ff]' %pf and %pF were obsoleted and later removed in favor of
2402 * %ps and %pS. Be careful when re-using these specifiers.
2403 * - 'B' For backtraced symbolic direct pointers with offset
2404 * - 'Bb' as above with module build ID (for use in backtraces)
2405 * - 'R' For decoded struct resource, e.g., [mem 0x0-0x1f 64bit pref]
2406 * - 'r' For raw struct resource, e.g., [mem 0x0-0x1f flags 0x201]
2407 * - 'ra' For struct ranges, e.g., [range 0x0000000000000000 - 0x00000000000000ff]
2408 * - 'b[l]' For a bitmap, the number of bits is determined by the field
2409 * width which must be explicitly specified either as part of the
2410 * format string '%32b[l]' or through '%*b[l]', [l] selects
2411 * range-list format instead of hex format
2412 * - 'M' For a 6-byte MAC address, it prints the address in the
2413 * usual colon-separated hex notation
2414 * - 'm' For a 6-byte MAC address, it prints the hex address without colons
2415 * - 'MF' For a 6-byte MAC FDDI address, it prints the address
2416 * with a dash-separated hex notation
2417 * - '[mM]R' For a 6-byte MAC address, Reverse order (Bluetooth)
2418 * - 'I' [46] for IPv4/IPv6 addresses printed in the usual way
2419 * IPv4 uses dot-separated decimal without leading 0's (1.2.3.4)
2420 * IPv6 uses colon separated network-order 16 bit hex with leading 0's
2421 * [S][pfs]
2422 * Generic IPv4/IPv6 address (struct sockaddr *) that falls back to
2423 * [4] or [6] and is able to print port [p], flowinfo [f], scope [s]
2424 * - 'i' [46] for 'raw' IPv4/IPv6 addresses
2425 * IPv6 omits the colons (01020304...0f)
2426 * IPv4 uses dot-separated decimal with leading 0's (010.123.045.006)
2427 * [S][pfs]
2428 * Generic IPv4/IPv6 address (struct sockaddr *) that falls back to
2429 * [4] or [6] and is able to print port [p], flowinfo [f], scope [s]
2430 * - '[Ii][4S][hnbl]' IPv4 addresses in host, network, big or little endian order
2431 * - 'I[6S]c' for IPv6 addresses printed as specified by
2432 * https://tools.ietf.org/html/rfc5952
2433 * - 'E[achnops]' For an escaped buffer, where rules are defined by combination
2434 * of the following flags (see string_escape_mem() for the
2435 * details):
2436 * a - ESCAPE_ANY
2437 * c - ESCAPE_SPECIAL
2438 * h - ESCAPE_HEX
2439 * n - ESCAPE_NULL
2440 * o - ESCAPE_OCTAL
2441 * p - ESCAPE_NP
2442 * s - ESCAPE_SPACE
2443 * By default ESCAPE_ANY_NP is used.
2444 * - 'U' For a 16 byte UUID/GUID, it prints the UUID/GUID in the form
2445 * "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx"
2446 * Options for %pU are:
2447 * b big endian lower case hex (default)
2448 * B big endian UPPER case hex
2449 * l little endian lower case hex
2450 * L little endian UPPER case hex
2451 * big endian output byte order is:
2452 * [0][1][2][3]-[4][5]-[6][7]-[8][9]-[10][11][12][13][14][15]
2453 * little endian output byte order is:
2454 * [3][2][1][0]-[5][4]-[7][6]-[8][9]-[10][11][12][13][14][15]
2455 * - 'V' For a struct va_format which contains a format string * and va_list *,
2456 * call vsnprintf(->format, *->va_list).
2457 * Implements a "recursive vsnprintf".
2458 * Do not use this feature without some mechanism to verify the
2459 * correctness of the format string and va_list arguments.
2460 * - 'K' For a kernel pointer that should be hidden from unprivileged users.
2461 * Use only for procfs, sysfs and similar files, not printk(); please
2462 * read the documentation (path below) first.
2463 * - 'NF' For a netdev_features_t
2464 * - '4cc' V4L2 or DRM FourCC code, with endianness and raw numerical value.
2465 * - '4c[h[R]lb]' For generic FourCC code with raw numerical value. Both are
2466 * displayed in the big-endian format. This is the opposite of V4L2 or
2467 * DRM FourCCs.
2468 * The additional specifiers define what endianness is used to load
2469 * the stored bytes. The data might be interpreted using the host,
2470 * reversed host byte order, little-endian, or big-endian.
2471 * - 'h[CDN]' For a variable-length buffer, it prints it as a hex string with
2472 * a certain separator (' ' by default):
2473 * C colon
2474 * D dash
2475 * N no separator
2476 * The maximum supported length is 64 bytes of the input. Consider
2477 * to use print_hex_dump() for the larger input.
2478 * - 'a[pd]' For address types [p] phys_addr_t, [d] dma_addr_t and derivatives
2479 * (default assumed to be phys_addr_t, passed by reference)
2480 * - 'd[234]' For a dentry name (optionally 2-4 last components)
2481 * - 'D[234]' Same as 'd' but for a struct file
2482 * - 'g' For block_device name (gendisk + partition number)
2483 * - 't[RST][dt][r][s]' For time and date as represented by:
2484 * R struct rtc_time
2485 * S struct timespec64
2486 * T time64_t
2487 * - 'tSp' For time represented by struct timespec64 printed as <seconds>.<nanoseconds>
2488 * - 'C' For a clock, it prints the name (Common Clock Framework) or address
2489 * (legacy clock framework) of the clock
2490 * - 'G' For flags to be printed as a collection of symbolic strings that would
2491 * construct the specific value. Supported flags given by option:
2492 * p page flags (see struct page) given as pointer to unsigned long
2493 * g gfp flags (GFP_* and __GFP_*) given as pointer to gfp_t
2494 * v vma flags (VM_*) given as pointer to unsigned long
2495 * - 'OF[fnpPcCF]' For a device tree object
2496 * Without any optional arguments prints the full_name
2497 * f device node full_name
2498 * n device node name
2499 * p device node phandle
2500 * P device node path spec (name + @unit)
2501 * F device node flags
2502 * c major compatible string
2503 * C full compatible string
2504 * - 'fw[fP]' For a firmware node (struct fwnode_handle) pointer
2505 * Without an option prints the full name of the node
2506 * f full name
2507 * P node name, including a possible unit address
2508 * - 'x' For printing the address unmodified. Equivalent to "%lx".
2509 * Please read the documentation (path below) before using!
2510 * - '[ku]s' For a BPF/tracing related format specifier, e.g. used out of
2511 * bpf_trace_printk() where [ku] prefix specifies either kernel (k)
2512 * or user (u) memory to probe, and:
2513 * s a string, equivalent to "%s" on direct vsnprintf() use
2514 *
2515 * ** When making changes please also update:
2516 * Documentation/core-api/printk-formats.rst
2517 *
2518 * Note: The default behaviour (unadorned %p) is to hash the address,
2519 * rendering it useful as a unique identifier.
2520 *
2521 * There is also a '%pA' format specifier, but it is only intended to be used
2522 * from Rust code to format core::fmt::Arguments. Do *not* use it from C.
2523 * See rust/kernel/print.rs for details.
2524 */
2525 static noinline_for_stack
pointer(const char * fmt,char * buf,char * end,void * ptr,struct printf_spec spec)2526 char *pointer(const char *fmt, char *buf, char *end, void *ptr,
2527 struct printf_spec spec)
2528 {
2529 switch (*fmt) {
2530 case 'S':
2531 case 's':
2532 ptr = dereference_symbol_descriptor(ptr);
2533 fallthrough;
2534 case 'B':
2535 return symbol_string(buf, end, ptr, spec, fmt);
2536 case 'R':
2537 case 'r':
2538 return resource_or_range(fmt, buf, end, ptr, spec);
2539 case 'h':
2540 return hex_string(buf, end, ptr, spec, fmt);
2541 case 'b':
2542 switch (fmt[1]) {
2543 case 'l':
2544 return bitmap_list_string(buf, end, ptr, spec, fmt);
2545 default:
2546 return bitmap_string(buf, end, ptr, spec, fmt);
2547 }
2548 case 'M': /* Colon separated: 00:01:02:03:04:05 */
2549 case 'm': /* Contiguous: 000102030405 */
2550 /* [mM]F (FDDI) */
2551 /* [mM]R (Reverse order; Bluetooth) */
2552 return mac_address_string(buf, end, ptr, spec, fmt);
2553 case 'I': /* Formatted IP supported
2554 * 4: 1.2.3.4
2555 * 6: 0001:0203:...:0708
2556 * 6c: 1::708 or 1::1.2.3.4
2557 */
2558 case 'i': /* Contiguous:
2559 * 4: 001.002.003.004
2560 * 6: 000102...0f
2561 */
2562 return ip_addr_string(buf, end, ptr, spec, fmt);
2563 case 'E':
2564 return escaped_string(buf, end, ptr, spec, fmt);
2565 case 'U':
2566 return uuid_string(buf, end, ptr, spec, fmt);
2567 case 'V':
2568 return va_format(buf, end, ptr, spec);
2569 case 'K':
2570 return restricted_pointer(buf, end, ptr, spec);
2571 case 'N':
2572 return netdev_bits(buf, end, ptr, spec, fmt);
2573 case '4':
2574 return fourcc_string(buf, end, ptr, spec, fmt);
2575 case 'a':
2576 return address_val(buf, end, ptr, spec, fmt);
2577 case 'd':
2578 return dentry_name(buf, end, ptr, spec, fmt);
2579 case 't':
2580 return time_and_date(buf, end, ptr, spec, fmt);
2581 case 'C':
2582 return clock(buf, end, ptr, spec, fmt);
2583 case 'D':
2584 return file_dentry_name(buf, end, ptr, spec, fmt);
2585 #ifdef CONFIG_BLOCK
2586 case 'g':
2587 return bdev_name(buf, end, ptr, spec, fmt);
2588 #endif
2589
2590 case 'G':
2591 return flags_string(buf, end, ptr, spec, fmt);
2592 case 'O':
2593 return device_node_string(buf, end, ptr, spec, fmt + 1);
2594 case 'f':
2595 return fwnode_string(buf, end, ptr, spec, fmt + 1);
2596 case 'A':
2597 if (!IS_ENABLED(CONFIG_RUST)) {
2598 WARN_ONCE(1, "Please remove %%pA from non-Rust code\n");
2599 return error_string(buf, end, "(%pA?)", spec);
2600 }
2601 return rust_fmt_argument(buf, end, ptr);
2602 case 'x':
2603 return pointer_string(buf, end, ptr, spec);
2604 case 'e':
2605 /* %pe with a non-ERR_PTR gets treated as plain %p */
2606 if (!IS_ERR(ptr))
2607 return default_pointer(buf, end, ptr, spec);
2608 return err_ptr(buf, end, ptr, spec);
2609 case 'u':
2610 case 'k':
2611 switch (fmt[1]) {
2612 case 's':
2613 return string(buf, end, ptr, spec);
2614 default:
2615 return error_string(buf, end, "(einval)", spec);
2616 }
2617 default:
2618 return default_pointer(buf, end, ptr, spec);
2619 }
2620 }
2621
2622 struct fmt {
2623 const char *str;
2624 unsigned char state; // enum format_state
2625 unsigned char size; // size of numbers
2626 };
2627
2628 #define SPEC_CHAR(x, flag) [(x)-32] = flag
spec_flag(unsigned char c)2629 static unsigned char spec_flag(unsigned char c)
2630 {
2631 static const unsigned char spec_flag_array[] = {
2632 SPEC_CHAR(' ', SPACE),
2633 SPEC_CHAR('#', SPECIAL),
2634 SPEC_CHAR('+', PLUS),
2635 SPEC_CHAR('-', LEFT),
2636 SPEC_CHAR('0', ZEROPAD),
2637 };
2638 c -= 32;
2639 return (c < sizeof(spec_flag_array)) ? spec_flag_array[c] : 0;
2640 }
2641
2642 /*
2643 * Helper function to decode printf style format.
2644 * Each call decode a token from the format and return the
2645 * number of characters read (or likely the delta where it wants
2646 * to go on the next call).
2647 * The decoded token is returned through the parameters
2648 *
2649 * 'h', 'l', or 'L' for integer fields
2650 * 'z' support added 23/7/1999 S.H.
2651 * 'z' changed to 'Z' --davidm 1/25/99
2652 * 'Z' changed to 'z' --adobriyan 2017-01-25
2653 * 't' added for ptrdiff_t
2654 *
2655 * @fmt: the format string
2656 * @type of the token returned
2657 * @flags: various flags such as +, -, # tokens..
2658 * @field_width: overwritten width
2659 * @base: base of the number (octal, hex, ...)
2660 * @precision: precision of a number
2661 * @qualifier: qualifier of a number (long, size_t, ...)
2662 */
2663 static noinline_for_stack
format_decode(struct fmt fmt,struct printf_spec * spec)2664 struct fmt format_decode(struct fmt fmt, struct printf_spec *spec)
2665 {
2666 const char *start = fmt.str;
2667 char flag;
2668
2669 /* we finished early by reading the field width */
2670 if (unlikely(fmt.state == FORMAT_STATE_WIDTH)) {
2671 if (spec->field_width < 0) {
2672 spec->field_width = -spec->field_width;
2673 spec->flags |= LEFT;
2674 }
2675 fmt.state = FORMAT_STATE_NONE;
2676 goto precision;
2677 }
2678
2679 /* we finished early by reading the precision */
2680 if (unlikely(fmt.state == FORMAT_STATE_PRECISION)) {
2681 if (spec->precision < 0)
2682 spec->precision = 0;
2683
2684 fmt.state = FORMAT_STATE_NONE;
2685 goto qualifier;
2686 }
2687
2688 /* By default */
2689 fmt.state = FORMAT_STATE_NONE;
2690
2691 for (; *fmt.str ; fmt.str++) {
2692 if (*fmt.str == '%')
2693 break;
2694 }
2695
2696 /* Return the current non-format string */
2697 if (fmt.str != start || !*fmt.str)
2698 return fmt;
2699
2700 /* Process flags. This also skips the first '%' */
2701 spec->flags = 0;
2702 do {
2703 /* this also skips first '%' */
2704 flag = spec_flag(*++fmt.str);
2705 spec->flags |= flag;
2706 } while (flag);
2707
2708 /* get field width */
2709 spec->field_width = -1;
2710
2711 if (isdigit(*fmt.str))
2712 spec->field_width = skip_atoi(&fmt.str);
2713 else if (unlikely(*fmt.str == '*')) {
2714 /* it's the next argument */
2715 fmt.state = FORMAT_STATE_WIDTH;
2716 fmt.str++;
2717 return fmt;
2718 }
2719
2720 precision:
2721 /* get the precision */
2722 spec->precision = -1;
2723 if (unlikely(*fmt.str == '.')) {
2724 fmt.str++;
2725 if (isdigit(*fmt.str)) {
2726 spec->precision = skip_atoi(&fmt.str);
2727 if (spec->precision < 0)
2728 spec->precision = 0;
2729 } else if (*fmt.str == '*') {
2730 /* it's the next argument */
2731 fmt.state = FORMAT_STATE_PRECISION;
2732 fmt.str++;
2733 return fmt;
2734 }
2735 }
2736
2737 qualifier:
2738 /* Set up default numeric format */
2739 spec->base = 10;
2740 fmt.state = FORMAT_STATE_NUM;
2741 fmt.size = sizeof(int);
2742 static const struct format_state {
2743 unsigned char state;
2744 unsigned char size;
2745 unsigned char flags_or_double_size;
2746 unsigned char base;
2747 } lookup_state[256] = {
2748 // Length
2749 ['l'] = { 0, sizeof(long), sizeof(long long) },
2750 ['L'] = { 0, sizeof(long long) },
2751 ['h'] = { 0, sizeof(short), sizeof(char) },
2752 ['H'] = { 0, sizeof(char) }, // Questionable historical
2753 ['z'] = { 0, sizeof(size_t) },
2754 ['t'] = { 0, sizeof(ptrdiff_t) },
2755
2756 // Non-numeric formats
2757 ['c'] = { FORMAT_STATE_CHAR },
2758 ['s'] = { FORMAT_STATE_STR },
2759 ['p'] = { FORMAT_STATE_PTR },
2760 ['%'] = { FORMAT_STATE_PERCENT_CHAR },
2761
2762 // Numerics
2763 ['o'] = { FORMAT_STATE_NUM, 0, 0, 8 },
2764 ['x'] = { FORMAT_STATE_NUM, 0, SMALL, 16 },
2765 ['X'] = { FORMAT_STATE_NUM, 0, 0, 16 },
2766 ['d'] = { FORMAT_STATE_NUM, 0, SIGN, 10 },
2767 ['i'] = { FORMAT_STATE_NUM, 0, SIGN, 10 },
2768 ['u'] = { FORMAT_STATE_NUM, 0, 0, 10, },
2769
2770 /*
2771 * Since %n poses a greater security risk than
2772 * utility, treat it as any other invalid or
2773 * unsupported format specifier.
2774 */
2775 };
2776
2777 const struct format_state *p = lookup_state + (u8)*fmt.str;
2778 if (p->size) {
2779 fmt.size = p->size;
2780 if (p->flags_or_double_size && fmt.str[0] == fmt.str[1]) {
2781 fmt.size = p->flags_or_double_size;
2782 fmt.str++;
2783 }
2784 fmt.str++;
2785 p = lookup_state + *fmt.str;
2786 }
2787 if (p->state) {
2788 if (p->base)
2789 spec->base = p->base;
2790 spec->flags |= p->flags_or_double_size;
2791 fmt.state = p->state;
2792 fmt.str++;
2793 return fmt;
2794 }
2795
2796 WARN_ONCE(1, "Please remove unsupported %%%c in format string\n", *fmt.str);
2797 fmt.state = FORMAT_STATE_INVALID;
2798 return fmt;
2799 }
2800
2801 static void
set_field_width(struct printf_spec * spec,int width)2802 set_field_width(struct printf_spec *spec, int width)
2803 {
2804 spec->field_width = width;
2805 if (WARN_ONCE(spec->field_width != width, "field width %d too large", width)) {
2806 spec->field_width = clamp(width, -FIELD_WIDTH_MAX, FIELD_WIDTH_MAX);
2807 }
2808 }
2809
2810 static void
set_precision(struct printf_spec * spec,int prec)2811 set_precision(struct printf_spec *spec, int prec)
2812 {
2813 spec->precision = prec;
2814 if (WARN_ONCE(spec->precision != prec, "precision %d too large", prec)) {
2815 spec->precision = clamp(prec, 0, PRECISION_MAX);
2816 }
2817 }
2818
2819 /*
2820 * Turn a 1/2/4-byte value into a 64-bit one for printing: truncate
2821 * as necessary and deal with signedness.
2822 *
2823 * 'size' is the size of the value in bytes.
2824 */
convert_num_spec(unsigned int val,int size,struct printf_spec spec)2825 static unsigned long long convert_num_spec(unsigned int val, int size, struct printf_spec spec)
2826 {
2827 unsigned int shift = 32 - size*8;
2828
2829 val <<= shift;
2830 if (!(spec.flags & SIGN))
2831 return val >> shift;
2832 return (int)val >> shift;
2833 }
2834
2835 /**
2836 * vsnprintf - Format a string and place it in a buffer
2837 * @buf: The buffer to place the result into
2838 * @size: The size of the buffer, including the trailing null space
2839 * @fmt_str: The format string to use
2840 * @args: Arguments for the format string
2841 *
2842 * This function generally follows C99 vsnprintf, but has some
2843 * extensions and a few limitations:
2844 *
2845 * - ``%n`` is unsupported
2846 * - ``%p*`` is handled by pointer()
2847 *
2848 * See pointer() or Documentation/core-api/printk-formats.rst for more
2849 * extensive description.
2850 *
2851 * **Please update the documentation in both places when making changes**
2852 *
2853 * The return value is the number of characters which would
2854 * be generated for the given input, excluding the trailing
2855 * '\0', as per ISO C99. If you want to have the exact
2856 * number of characters written into @buf as return value
2857 * (not including the trailing '\0'), use vscnprintf(). If the
2858 * return is greater than or equal to @size, the resulting
2859 * string is truncated.
2860 *
2861 * If you're not already dealing with a va_list consider using snprintf().
2862 */
vsnprintf(char * buf,size_t size,const char * fmt_str,va_list args)2863 int vsnprintf(char *buf, size_t size, const char *fmt_str, va_list args)
2864 {
2865 char *str, *end;
2866 struct printf_spec spec = {0};
2867 struct fmt fmt = {
2868 .str = fmt_str,
2869 .state = FORMAT_STATE_NONE,
2870 };
2871
2872 /* Reject out-of-range values early. Large positive sizes are
2873 used for unknown buffer sizes. */
2874 if (WARN_ON_ONCE(size > INT_MAX))
2875 return 0;
2876
2877 str = buf;
2878 end = buf + size;
2879
2880 /* Make sure end is always >= buf */
2881 if (end < buf) {
2882 end = ((void *)-1);
2883 size = end - buf;
2884 }
2885
2886 while (*fmt.str) {
2887 const char *old_fmt = fmt.str;
2888
2889 fmt = format_decode(fmt, &spec);
2890
2891 switch (fmt.state) {
2892 case FORMAT_STATE_NONE: {
2893 int read = fmt.str - old_fmt;
2894 if (str < end) {
2895 int copy = read;
2896 if (copy > end - str)
2897 copy = end - str;
2898 memcpy(str, old_fmt, copy);
2899 }
2900 str += read;
2901 continue;
2902 }
2903
2904 case FORMAT_STATE_NUM: {
2905 unsigned long long num;
2906
2907 if (fmt.size > sizeof(int))
2908 num = va_arg(args, long long);
2909 else
2910 num = convert_num_spec(va_arg(args, int), fmt.size, spec);
2911 str = number(str, end, num, spec);
2912 continue;
2913 }
2914
2915 case FORMAT_STATE_WIDTH:
2916 set_field_width(&spec, va_arg(args, int));
2917 continue;
2918
2919 case FORMAT_STATE_PRECISION:
2920 set_precision(&spec, va_arg(args, int));
2921 continue;
2922
2923 case FORMAT_STATE_CHAR: {
2924 char c;
2925
2926 if (!(spec.flags & LEFT)) {
2927 while (--spec.field_width > 0) {
2928 if (str < end)
2929 *str = ' ';
2930 ++str;
2931
2932 }
2933 }
2934 c = (unsigned char) va_arg(args, int);
2935 if (str < end)
2936 *str = c;
2937 ++str;
2938 while (--spec.field_width > 0) {
2939 if (str < end)
2940 *str = ' ';
2941 ++str;
2942 }
2943 continue;
2944 }
2945
2946 case FORMAT_STATE_STR:
2947 str = string(str, end, va_arg(args, char *), spec);
2948 continue;
2949
2950 case FORMAT_STATE_PTR:
2951 str = pointer(fmt.str, str, end, va_arg(args, void *),
2952 spec);
2953 while (isalnum(*fmt.str))
2954 fmt.str++;
2955 continue;
2956
2957 case FORMAT_STATE_PERCENT_CHAR:
2958 if (str < end)
2959 *str = '%';
2960 ++str;
2961 continue;
2962
2963 default:
2964 /*
2965 * Presumably the arguments passed gcc's type
2966 * checking, but there is no safe or sane way
2967 * for us to continue parsing the format and
2968 * fetching from the va_list; the remaining
2969 * specifiers and arguments would be out of
2970 * sync.
2971 */
2972 goto out;
2973 }
2974 }
2975
2976 out:
2977 if (size > 0) {
2978 if (str < end)
2979 *str = '\0';
2980 else
2981 end[-1] = '\0';
2982 }
2983
2984 /* the trailing null byte doesn't count towards the total */
2985 return str-buf;
2986
2987 }
2988 EXPORT_SYMBOL(vsnprintf);
2989
2990 /**
2991 * vscnprintf - Format a string and place it in a buffer
2992 * @buf: The buffer to place the result into
2993 * @size: The size of the buffer, including the trailing null space
2994 * @fmt: The format string to use
2995 * @args: Arguments for the format string
2996 *
2997 * The return value is the number of characters which have been written into
2998 * the @buf not including the trailing '\0'. If @size is == 0 the function
2999 * returns 0.
3000 *
3001 * If you're not already dealing with a va_list consider using scnprintf().
3002 *
3003 * See the vsnprintf() documentation for format string extensions over C99.
3004 */
vscnprintf(char * buf,size_t size,const char * fmt,va_list args)3005 int vscnprintf(char *buf, size_t size, const char *fmt, va_list args)
3006 {
3007 int i;
3008
3009 if (unlikely(!size))
3010 return 0;
3011
3012 i = vsnprintf(buf, size, fmt, args);
3013
3014 if (likely(i < size))
3015 return i;
3016
3017 return size - 1;
3018 }
3019 EXPORT_SYMBOL(vscnprintf);
3020
3021 /**
3022 * snprintf - Format a string and place it in a buffer
3023 * @buf: The buffer to place the result into
3024 * @size: The size of the buffer, including the trailing null space
3025 * @fmt: The format string to use
3026 * @...: Arguments for the format string
3027 *
3028 * The return value is the number of characters which would be
3029 * generated for the given input, excluding the trailing null,
3030 * as per ISO C99. If the return is greater than or equal to
3031 * @size, the resulting string is truncated.
3032 *
3033 * See the vsnprintf() documentation for format string extensions over C99.
3034 */
snprintf(char * buf,size_t size,const char * fmt,...)3035 int snprintf(char *buf, size_t size, const char *fmt, ...)
3036 {
3037 va_list args;
3038 int i;
3039
3040 va_start(args, fmt);
3041 i = vsnprintf(buf, size, fmt, args);
3042 va_end(args);
3043
3044 return i;
3045 }
3046 EXPORT_SYMBOL(snprintf);
3047
3048 /**
3049 * scnprintf - Format a string and place it in a buffer
3050 * @buf: The buffer to place the result into
3051 * @size: The size of the buffer, including the trailing null space
3052 * @fmt: The format string to use
3053 * @...: Arguments for the format string
3054 *
3055 * The return value is the number of characters written into @buf not including
3056 * the trailing '\0'. If @size is == 0 the function returns 0.
3057 */
3058
scnprintf(char * buf,size_t size,const char * fmt,...)3059 int scnprintf(char *buf, size_t size, const char *fmt, ...)
3060 {
3061 va_list args;
3062 int i;
3063
3064 va_start(args, fmt);
3065 i = vscnprintf(buf, size, fmt, args);
3066 va_end(args);
3067
3068 return i;
3069 }
3070 EXPORT_SYMBOL(scnprintf);
3071
3072 /**
3073 * vsprintf - Format a string and place it in a buffer
3074 * @buf: The buffer to place the result into
3075 * @fmt: The format string to use
3076 * @args: Arguments for the format string
3077 *
3078 * The return value is the number of characters written into @buf not including
3079 * the trailing '\0'. Use vsnprintf() or vscnprintf() in order to avoid
3080 * buffer overflows.
3081 *
3082 * If you're not already dealing with a va_list consider using sprintf().
3083 *
3084 * See the vsnprintf() documentation for format string extensions over C99.
3085 */
vsprintf(char * buf,const char * fmt,va_list args)3086 int vsprintf(char *buf, const char *fmt, va_list args)
3087 {
3088 return vsnprintf(buf, INT_MAX, fmt, args);
3089 }
3090 EXPORT_SYMBOL(vsprintf);
3091
3092 /**
3093 * sprintf - Format a string and place it in a buffer
3094 * @buf: The buffer to place the result into
3095 * @fmt: The format string to use
3096 * @...: Arguments for the format string
3097 *
3098 * The return value is the number of characters written into @buf not including
3099 * the trailing '\0'. Use snprintf() or scnprintf() in order to avoid
3100 * buffer overflows.
3101 *
3102 * See the vsnprintf() documentation for format string extensions over C99.
3103 */
sprintf(char * buf,const char * fmt,...)3104 int sprintf(char *buf, const char *fmt, ...)
3105 {
3106 va_list args;
3107 int i;
3108
3109 va_start(args, fmt);
3110 i = vsnprintf(buf, INT_MAX, fmt, args);
3111 va_end(args);
3112
3113 return i;
3114 }
3115 EXPORT_SYMBOL(sprintf);
3116
3117 #ifdef CONFIG_BINARY_PRINTF
3118 /*
3119 * bprintf service:
3120 * vbin_printf() - VA arguments to binary data
3121 * bstr_printf() - Binary data to text string
3122 */
3123
3124 /**
3125 * vbin_printf - Parse a format string and place args' binary value in a buffer
3126 * @bin_buf: The buffer to place args' binary value
3127 * @size: The size of the buffer(by words(32bits), not characters)
3128 * @fmt_str: The format string to use
3129 * @args: Arguments for the format string
3130 *
3131 * The format follows C99 vsnprintf, except %n is ignored, and its argument
3132 * is skipped.
3133 *
3134 * The return value is the number of words(32bits) which would be generated for
3135 * the given input.
3136 *
3137 * NOTE:
3138 * If the return value is greater than @size, the resulting bin_buf is NOT
3139 * valid for bstr_printf().
3140 */
vbin_printf(u32 * bin_buf,size_t size,const char * fmt_str,va_list args)3141 int vbin_printf(u32 *bin_buf, size_t size, const char *fmt_str, va_list args)
3142 {
3143 struct fmt fmt = {
3144 .str = fmt_str,
3145 .state = FORMAT_STATE_NONE,
3146 };
3147 struct printf_spec spec = {0};
3148 char *str, *end;
3149 int width;
3150
3151 str = (char *)bin_buf;
3152 end = (char *)(bin_buf + size);
3153
3154 #define save_arg(type) \
3155 ({ \
3156 unsigned long long value; \
3157 if (sizeof(type) == 8) { \
3158 unsigned long long val8; \
3159 str = PTR_ALIGN(str, sizeof(u32)); \
3160 val8 = va_arg(args, unsigned long long); \
3161 if (str + sizeof(type) <= end) { \
3162 *(u32 *)str = *(u32 *)&val8; \
3163 *(u32 *)(str + 4) = *((u32 *)&val8 + 1); \
3164 } \
3165 value = val8; \
3166 } else { \
3167 unsigned int val4; \
3168 str = PTR_ALIGN(str, sizeof(type)); \
3169 val4 = va_arg(args, int); \
3170 if (str + sizeof(type) <= end) \
3171 *(typeof(type) *)str = (type)(long)val4; \
3172 value = (unsigned long long)val4; \
3173 } \
3174 str += sizeof(type); \
3175 value; \
3176 })
3177
3178 while (*fmt.str) {
3179 fmt = format_decode(fmt, &spec);
3180
3181 switch (fmt.state) {
3182 case FORMAT_STATE_NONE:
3183 case FORMAT_STATE_PERCENT_CHAR:
3184 break;
3185 case FORMAT_STATE_INVALID:
3186 goto out;
3187
3188 case FORMAT_STATE_WIDTH:
3189 case FORMAT_STATE_PRECISION:
3190 width = (int)save_arg(int);
3191 /* Pointers may require the width */
3192 if (*fmt.str == 'p')
3193 set_field_width(&spec, width);
3194 break;
3195
3196 case FORMAT_STATE_CHAR:
3197 save_arg(char);
3198 break;
3199
3200 case FORMAT_STATE_STR: {
3201 const char *save_str = va_arg(args, char *);
3202 const char *err_msg;
3203 size_t len;
3204
3205 err_msg = check_pointer_msg(save_str);
3206 if (err_msg)
3207 save_str = err_msg;
3208
3209 len = strlen(save_str) + 1;
3210 if (str + len < end)
3211 memcpy(str, save_str, len);
3212 str += len;
3213 break;
3214 }
3215
3216 case FORMAT_STATE_PTR:
3217 /* Dereferenced pointers must be done now */
3218 switch (*fmt.str) {
3219 /* Dereference of functions is still OK */
3220 case 'S':
3221 case 's':
3222 case 'x':
3223 case 'K':
3224 case 'e':
3225 save_arg(void *);
3226 break;
3227 default:
3228 if (!isalnum(*fmt.str)) {
3229 save_arg(void *);
3230 break;
3231 }
3232 str = pointer(fmt.str, str, end, va_arg(args, void *),
3233 spec);
3234 if (str + 1 < end)
3235 *str++ = '\0';
3236 else
3237 end[-1] = '\0'; /* Must be nul terminated */
3238 }
3239 /* skip all alphanumeric pointer suffixes */
3240 while (isalnum(*fmt.str))
3241 fmt.str++;
3242 break;
3243
3244 case FORMAT_STATE_NUM:
3245 if (fmt.size > sizeof(int)) {
3246 save_arg(long long);
3247 } else {
3248 save_arg(int);
3249 }
3250 }
3251 }
3252
3253 out:
3254 return (u32 *)(PTR_ALIGN(str, sizeof(u32))) - bin_buf;
3255 #undef save_arg
3256 }
3257 EXPORT_SYMBOL_GPL(vbin_printf);
3258
3259 /**
3260 * bstr_printf - Format a string from binary arguments and place it in a buffer
3261 * @buf: The buffer to place the result into
3262 * @size: The size of the buffer, including the trailing null space
3263 * @fmt_str: The format string to use
3264 * @bin_buf: Binary arguments for the format string
3265 *
3266 * This function like C99 vsnprintf, but the difference is that vsnprintf gets
3267 * arguments from stack, and bstr_printf gets arguments from @bin_buf which is
3268 * a binary buffer that generated by vbin_printf.
3269 *
3270 * The format follows C99 vsnprintf, but has some extensions:
3271 * see vsnprintf comment for details.
3272 *
3273 * The return value is the number of characters which would
3274 * be generated for the given input, excluding the trailing
3275 * '\0', as per ISO C99. If you want to have the exact
3276 * number of characters written into @buf as return value
3277 * (not including the trailing '\0'), use vscnprintf(). If the
3278 * return is greater than or equal to @size, the resulting
3279 * string is truncated.
3280 */
bstr_printf(char * buf,size_t size,const char * fmt_str,const u32 * bin_buf)3281 int bstr_printf(char *buf, size_t size, const char *fmt_str, const u32 *bin_buf)
3282 {
3283 struct fmt fmt = {
3284 .str = fmt_str,
3285 .state = FORMAT_STATE_NONE,
3286 };
3287 struct printf_spec spec = {0};
3288 char *str, *end;
3289 const char *args = (const char *)bin_buf;
3290
3291 if (WARN_ON_ONCE(size > INT_MAX))
3292 return 0;
3293
3294 str = buf;
3295 end = buf + size;
3296
3297 #define get_arg(type) \
3298 ({ \
3299 typeof(type) value; \
3300 if (sizeof(type) == 8) { \
3301 args = PTR_ALIGN(args, sizeof(u32)); \
3302 *(u32 *)&value = *(u32 *)args; \
3303 *((u32 *)&value + 1) = *(u32 *)(args + 4); \
3304 } else { \
3305 args = PTR_ALIGN(args, sizeof(type)); \
3306 value = *(typeof(type) *)args; \
3307 } \
3308 args += sizeof(type); \
3309 value; \
3310 })
3311
3312 /* Make sure end is always >= buf */
3313 if (end < buf) {
3314 end = ((void *)-1);
3315 size = end - buf;
3316 }
3317
3318 while (*fmt.str) {
3319 const char *old_fmt = fmt.str;
3320 unsigned long long num;
3321
3322 fmt = format_decode(fmt, &spec);
3323 switch (fmt.state) {
3324 case FORMAT_STATE_NONE: {
3325 int read = fmt.str - old_fmt;
3326 if (str < end) {
3327 int copy = read;
3328 if (copy > end - str)
3329 copy = end - str;
3330 memcpy(str, old_fmt, copy);
3331 }
3332 str += read;
3333 continue;
3334 }
3335
3336 case FORMAT_STATE_WIDTH:
3337 set_field_width(&spec, get_arg(int));
3338 continue;
3339
3340 case FORMAT_STATE_PRECISION:
3341 set_precision(&spec, get_arg(int));
3342 continue;
3343
3344 case FORMAT_STATE_CHAR: {
3345 char c;
3346
3347 if (!(spec.flags & LEFT)) {
3348 while (--spec.field_width > 0) {
3349 if (str < end)
3350 *str = ' ';
3351 ++str;
3352 }
3353 }
3354 c = (unsigned char) get_arg(char);
3355 if (str < end)
3356 *str = c;
3357 ++str;
3358 while (--spec.field_width > 0) {
3359 if (str < end)
3360 *str = ' ';
3361 ++str;
3362 }
3363 continue;
3364 }
3365
3366 case FORMAT_STATE_STR: {
3367 const char *str_arg = args;
3368 args += strlen(str_arg) + 1;
3369 str = string(str, end, (char *)str_arg, spec);
3370 continue;
3371 }
3372
3373 case FORMAT_STATE_PTR: {
3374 bool process = false;
3375 int copy, len;
3376 /* Non function dereferences were already done */
3377 switch (*fmt.str) {
3378 case 'S':
3379 case 's':
3380 case 'x':
3381 case 'K':
3382 case 'e':
3383 process = true;
3384 break;
3385 default:
3386 if (!isalnum(*fmt.str)) {
3387 process = true;
3388 break;
3389 }
3390 /* Pointer dereference was already processed */
3391 if (str < end) {
3392 len = copy = strlen(args);
3393 if (copy > end - str)
3394 copy = end - str;
3395 memcpy(str, args, copy);
3396 str += len;
3397 args += len + 1;
3398 }
3399 }
3400 if (process)
3401 str = pointer(fmt.str, str, end, get_arg(void *), spec);
3402
3403 while (isalnum(*fmt.str))
3404 fmt.str++;
3405 continue;
3406 }
3407
3408 case FORMAT_STATE_PERCENT_CHAR:
3409 if (str < end)
3410 *str = '%';
3411 ++str;
3412 continue;
3413
3414 case FORMAT_STATE_INVALID:
3415 goto out;
3416
3417 case FORMAT_STATE_NUM:
3418 if (fmt.size > sizeof(int))
3419 num = get_arg(long long);
3420 else
3421 num = convert_num_spec(get_arg(int), fmt.size, spec);
3422 str = number(str, end, num, spec);
3423 continue;
3424 }
3425 } /* while(*fmt.str) */
3426
3427 out:
3428 if (size > 0) {
3429 if (str < end)
3430 *str = '\0';
3431 else
3432 end[-1] = '\0';
3433 }
3434
3435 #undef get_arg
3436
3437 /* the trailing null byte doesn't count towards the total */
3438 return str - buf;
3439 }
3440 EXPORT_SYMBOL_GPL(bstr_printf);
3441
3442 #endif /* CONFIG_BINARY_PRINTF */
3443
3444 /**
3445 * vsscanf - Unformat a buffer into a list of arguments
3446 * @buf: input buffer
3447 * @fmt: format of buffer
3448 * @args: arguments
3449 */
vsscanf(const char * buf,const char * fmt,va_list args)3450 int vsscanf(const char *buf, const char *fmt, va_list args)
3451 {
3452 const char *str = buf;
3453 char *next;
3454 char digit;
3455 int num = 0;
3456 u8 qualifier;
3457 unsigned int base;
3458 union {
3459 long long s;
3460 unsigned long long u;
3461 } val;
3462 s16 field_width;
3463 bool is_sign;
3464
3465 while (*fmt) {
3466 /* skip any white space in format */
3467 /* white space in format matches any amount of
3468 * white space, including none, in the input.
3469 */
3470 if (isspace(*fmt)) {
3471 fmt = skip_spaces(++fmt);
3472 str = skip_spaces(str);
3473 }
3474
3475 /* anything that is not a conversion must match exactly */
3476 if (*fmt != '%' && *fmt) {
3477 if (*fmt++ != *str++)
3478 break;
3479 continue;
3480 }
3481
3482 if (!*fmt)
3483 break;
3484 ++fmt;
3485
3486 /* skip this conversion.
3487 * advance both strings to next white space
3488 */
3489 if (*fmt == '*') {
3490 if (!*str)
3491 break;
3492 while (!isspace(*fmt) && *fmt != '%' && *fmt) {
3493 /* '%*[' not yet supported, invalid format */
3494 if (*fmt == '[')
3495 return num;
3496 fmt++;
3497 }
3498 while (!isspace(*str) && *str)
3499 str++;
3500 continue;
3501 }
3502
3503 /* get field width */
3504 field_width = -1;
3505 if (isdigit(*fmt)) {
3506 field_width = skip_atoi(&fmt);
3507 if (field_width <= 0)
3508 break;
3509 }
3510
3511 /* get conversion qualifier */
3512 qualifier = -1;
3513 if (*fmt == 'h' || _tolower(*fmt) == 'l' ||
3514 *fmt == 'z') {
3515 qualifier = *fmt++;
3516 if (unlikely(qualifier == *fmt)) {
3517 if (qualifier == 'h') {
3518 qualifier = 'H';
3519 fmt++;
3520 } else if (qualifier == 'l') {
3521 qualifier = 'L';
3522 fmt++;
3523 }
3524 }
3525 }
3526
3527 if (!*fmt)
3528 break;
3529
3530 if (*fmt == 'n') {
3531 /* return number of characters read so far */
3532 *va_arg(args, int *) = str - buf;
3533 ++fmt;
3534 continue;
3535 }
3536
3537 if (!*str)
3538 break;
3539
3540 base = 10;
3541 is_sign = false;
3542
3543 switch (*fmt++) {
3544 case 'c':
3545 {
3546 char *s = (char *)va_arg(args, char*);
3547 if (field_width == -1)
3548 field_width = 1;
3549 do {
3550 *s++ = *str++;
3551 } while (--field_width > 0 && *str);
3552 num++;
3553 }
3554 continue;
3555 case 's':
3556 {
3557 char *s = (char *)va_arg(args, char *);
3558 if (field_width == -1)
3559 field_width = SHRT_MAX;
3560 /* first, skip leading white space in buffer */
3561 str = skip_spaces(str);
3562
3563 /* now copy until next white space */
3564 while (*str && !isspace(*str) && field_width--)
3565 *s++ = *str++;
3566 *s = '\0';
3567 num++;
3568 }
3569 continue;
3570 /*
3571 * Warning: This implementation of the '[' conversion specifier
3572 * deviates from its glibc counterpart in the following ways:
3573 * (1) It does NOT support ranges i.e. '-' is NOT a special
3574 * character
3575 * (2) It cannot match the closing bracket ']' itself
3576 * (3) A field width is required
3577 * (4) '%*[' (discard matching input) is currently not supported
3578 *
3579 * Example usage:
3580 * ret = sscanf("00:0a:95","%2[^:]:%2[^:]:%2[^:]",
3581 * buf1, buf2, buf3);
3582 * if (ret < 3)
3583 * // etc..
3584 */
3585 case '[':
3586 {
3587 char *s = (char *)va_arg(args, char *);
3588 DECLARE_BITMAP(set, 256) = {0};
3589 unsigned int len = 0;
3590 bool negate = (*fmt == '^');
3591
3592 /* field width is required */
3593 if (field_width == -1)
3594 return num;
3595
3596 if (negate)
3597 ++fmt;
3598
3599 for ( ; *fmt && *fmt != ']'; ++fmt, ++len)
3600 __set_bit((u8)*fmt, set);
3601
3602 /* no ']' or no character set found */
3603 if (!*fmt || !len)
3604 return num;
3605 ++fmt;
3606
3607 if (negate) {
3608 bitmap_complement(set, set, 256);
3609 /* exclude null '\0' byte */
3610 __clear_bit(0, set);
3611 }
3612
3613 /* match must be non-empty */
3614 if (!test_bit((u8)*str, set))
3615 return num;
3616
3617 while (test_bit((u8)*str, set) && field_width--)
3618 *s++ = *str++;
3619 *s = '\0';
3620 ++num;
3621 }
3622 continue;
3623 case 'o':
3624 base = 8;
3625 break;
3626 case 'x':
3627 case 'X':
3628 base = 16;
3629 break;
3630 case 'i':
3631 base = 0;
3632 fallthrough;
3633 case 'd':
3634 is_sign = true;
3635 fallthrough;
3636 case 'u':
3637 break;
3638 case '%':
3639 /* looking for '%' in str */
3640 if (*str++ != '%')
3641 return num;
3642 continue;
3643 default:
3644 /* invalid format; stop here */
3645 return num;
3646 }
3647
3648 /* have some sort of integer conversion.
3649 * first, skip white space in buffer.
3650 */
3651 str = skip_spaces(str);
3652
3653 digit = *str;
3654 if (is_sign && digit == '-') {
3655 if (field_width == 1)
3656 break;
3657
3658 digit = *(str + 1);
3659 }
3660
3661 if (!digit
3662 || (base == 16 && !isxdigit(digit))
3663 || (base == 10 && !isdigit(digit))
3664 || (base == 8 && !isodigit(digit))
3665 || (base == 0 && !isdigit(digit)))
3666 break;
3667
3668 if (is_sign)
3669 val.s = simple_strntoll(str, &next, base,
3670 field_width >= 0 ? field_width : INT_MAX);
3671 else
3672 val.u = simple_strntoull(str, &next, base,
3673 field_width >= 0 ? field_width : INT_MAX);
3674
3675 switch (qualifier) {
3676 case 'H': /* that's 'hh' in format */
3677 if (is_sign)
3678 *va_arg(args, signed char *) = val.s;
3679 else
3680 *va_arg(args, unsigned char *) = val.u;
3681 break;
3682 case 'h':
3683 if (is_sign)
3684 *va_arg(args, short *) = val.s;
3685 else
3686 *va_arg(args, unsigned short *) = val.u;
3687 break;
3688 case 'l':
3689 if (is_sign)
3690 *va_arg(args, long *) = val.s;
3691 else
3692 *va_arg(args, unsigned long *) = val.u;
3693 break;
3694 case 'L':
3695 if (is_sign)
3696 *va_arg(args, long long *) = val.s;
3697 else
3698 *va_arg(args, unsigned long long *) = val.u;
3699 break;
3700 case 'z':
3701 *va_arg(args, size_t *) = val.u;
3702 break;
3703 default:
3704 if (is_sign)
3705 *va_arg(args, int *) = val.s;
3706 else
3707 *va_arg(args, unsigned int *) = val.u;
3708 break;
3709 }
3710 num++;
3711
3712 if (!next)
3713 break;
3714 str = next;
3715 }
3716
3717 return num;
3718 }
3719 EXPORT_SYMBOL(vsscanf);
3720
3721 /**
3722 * sscanf - Unformat a buffer into a list of arguments
3723 * @buf: input buffer
3724 * @fmt: formatting of buffer
3725 * @...: resulting arguments
3726 */
sscanf(const char * buf,const char * fmt,...)3727 int sscanf(const char *buf, const char *fmt, ...)
3728 {
3729 va_list args;
3730 int i;
3731
3732 va_start(args, fmt);
3733 i = vsscanf(buf, fmt, args);
3734 va_end(args);
3735
3736 return i;
3737 }
3738 EXPORT_SYMBOL(sscanf);
3739