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Merge branch 'next-integrity' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorri...
[thirdparty/kernel/stable.git] / lib / vsprintf.c
1 /*
2 * linux/lib/vsprintf.c
3 *
4 * Copyright (C) 1991, 1992 Linus Torvalds
5 */
6
7 /* vsprintf.c -- Lars Wirzenius & Linus Torvalds. */
8 /*
9 * Wirzenius wrote this portably, Torvalds fucked it up :-)
10 */
11
12 /*
13 * Fri Jul 13 2001 Crutcher Dunnavant <crutcher+kernel@datastacks.com>
14 * - changed to provide snprintf and vsnprintf functions
15 * So Feb 1 16:51:32 CET 2004 Juergen Quade <quade@hsnr.de>
16 * - scnprintf and vscnprintf
17 */
18
19 #include <stdarg.h>
20 #include <linux/build_bug.h>
21 #include <linux/clk.h>
22 #include <linux/clk-provider.h>
23 #include <linux/module.h> /* for KSYM_SYMBOL_LEN */
24 #include <linux/types.h>
25 #include <linux/string.h>
26 #include <linux/ctype.h>
27 #include <linux/kernel.h>
28 #include <linux/kallsyms.h>
29 #include <linux/math64.h>
30 #include <linux/uaccess.h>
31 #include <linux/ioport.h>
32 #include <linux/dcache.h>
33 #include <linux/cred.h>
34 #include <linux/rtc.h>
35 #include <linux/uuid.h>
36 #include <linux/of.h>
37 #include <net/addrconf.h>
38 #include <linux/siphash.h>
39 #include <linux/compiler.h>
40 #ifdef CONFIG_BLOCK
41 #include <linux/blkdev.h>
42 #endif
43
44 #include "../mm/internal.h" /* For the trace_print_flags arrays */
45
46 #include <asm/page.h> /* for PAGE_SIZE */
47 #include <asm/byteorder.h> /* cpu_to_le16 */
48
49 #include <linux/string_helpers.h>
50 #include "kstrtox.h"
51
52 /**
53 * simple_strtoull - convert a string to an unsigned long long
54 * @cp: The start of the string
55 * @endp: A pointer to the end of the parsed string will be placed here
56 * @base: The number base to use
57 *
58 * This function is obsolete. Please use kstrtoull instead.
59 */
60 unsigned long long simple_strtoull(const char *cp, char **endp, unsigned int base)
61 {
62 unsigned long long result;
63 unsigned int rv;
64
65 cp = _parse_integer_fixup_radix(cp, &base);
66 rv = _parse_integer(cp, base, &result);
67 /* FIXME */
68 cp += (rv & ~KSTRTOX_OVERFLOW);
69
70 if (endp)
71 *endp = (char *)cp;
72
73 return result;
74 }
75 EXPORT_SYMBOL(simple_strtoull);
76
77 /**
78 * simple_strtoul - convert a string to an unsigned long
79 * @cp: The start of the string
80 * @endp: A pointer to the end of the parsed string will be placed here
81 * @base: The number base to use
82 *
83 * This function is obsolete. Please use kstrtoul instead.
84 */
85 unsigned long simple_strtoul(const char *cp, char **endp, unsigned int base)
86 {
87 return simple_strtoull(cp, endp, base);
88 }
89 EXPORT_SYMBOL(simple_strtoul);
90
91 /**
92 * simple_strtol - convert a string to a signed long
93 * @cp: The start of the string
94 * @endp: A pointer to the end of the parsed string will be placed here
95 * @base: The number base to use
96 *
97 * This function is obsolete. Please use kstrtol instead.
98 */
99 long simple_strtol(const char *cp, char **endp, unsigned int base)
100 {
101 if (*cp == '-')
102 return -simple_strtoul(cp + 1, endp, base);
103
104 return simple_strtoul(cp, endp, base);
105 }
106 EXPORT_SYMBOL(simple_strtol);
107
108 /**
109 * simple_strtoll - convert a string to a signed long long
110 * @cp: The start of the string
111 * @endp: A pointer to the end of the parsed string will be placed here
112 * @base: The number base to use
113 *
114 * This function is obsolete. Please use kstrtoll instead.
115 */
116 long long simple_strtoll(const char *cp, char **endp, unsigned int base)
117 {
118 if (*cp == '-')
119 return -simple_strtoull(cp + 1, endp, base);
120
121 return simple_strtoull(cp, endp, base);
122 }
123 EXPORT_SYMBOL(simple_strtoll);
124
125 static noinline_for_stack
126 int skip_atoi(const char **s)
127 {
128 int i = 0;
129
130 do {
131 i = i*10 + *((*s)++) - '0';
132 } while (isdigit(**s));
133
134 return i;
135 }
136
137 /*
138 * Decimal conversion is by far the most typical, and is used for
139 * /proc and /sys data. This directly impacts e.g. top performance
140 * with many processes running. We optimize it for speed by emitting
141 * two characters at a time, using a 200 byte lookup table. This
142 * roughly halves the number of multiplications compared to computing
143 * the digits one at a time. Implementation strongly inspired by the
144 * previous version, which in turn used ideas described at
145 * <http://www.cs.uiowa.edu/~jones/bcd/divide.html> (with permission
146 * from the author, Douglas W. Jones).
147 *
148 * It turns out there is precisely one 26 bit fixed-point
149 * approximation a of 64/100 for which x/100 == (x * (u64)a) >> 32
150 * holds for all x in [0, 10^8-1], namely a = 0x28f5c29. The actual
151 * range happens to be somewhat larger (x <= 1073741898), but that's
152 * irrelevant for our purpose.
153 *
154 * For dividing a number in the range [10^4, 10^6-1] by 100, we still
155 * need a 32x32->64 bit multiply, so we simply use the same constant.
156 *
157 * For dividing a number in the range [100, 10^4-1] by 100, there are
158 * several options. The simplest is (x * 0x147b) >> 19, which is valid
159 * for all x <= 43698.
160 */
161
162 static const u16 decpair[100] = {
163 #define _(x) (__force u16) cpu_to_le16(((x % 10) | ((x / 10) << 8)) + 0x3030)
164 _( 0), _( 1), _( 2), _( 3), _( 4), _( 5), _( 6), _( 7), _( 8), _( 9),
165 _(10), _(11), _(12), _(13), _(14), _(15), _(16), _(17), _(18), _(19),
166 _(20), _(21), _(22), _(23), _(24), _(25), _(26), _(27), _(28), _(29),
167 _(30), _(31), _(32), _(33), _(34), _(35), _(36), _(37), _(38), _(39),
168 _(40), _(41), _(42), _(43), _(44), _(45), _(46), _(47), _(48), _(49),
169 _(50), _(51), _(52), _(53), _(54), _(55), _(56), _(57), _(58), _(59),
170 _(60), _(61), _(62), _(63), _(64), _(65), _(66), _(67), _(68), _(69),
171 _(70), _(71), _(72), _(73), _(74), _(75), _(76), _(77), _(78), _(79),
172 _(80), _(81), _(82), _(83), _(84), _(85), _(86), _(87), _(88), _(89),
173 _(90), _(91), _(92), _(93), _(94), _(95), _(96), _(97), _(98), _(99),
174 #undef _
175 };
176
177 /*
178 * This will print a single '0' even if r == 0, since we would
179 * immediately jump to out_r where two 0s would be written but only
180 * one of them accounted for in buf. This is needed by ip4_string
181 * below. All other callers pass a non-zero value of r.
182 */
183 static noinline_for_stack
184 char *put_dec_trunc8(char *buf, unsigned r)
185 {
186 unsigned q;
187
188 /* 1 <= r < 10^8 */
189 if (r < 100)
190 goto out_r;
191
192 /* 100 <= r < 10^8 */
193 q = (r * (u64)0x28f5c29) >> 32;
194 *((u16 *)buf) = decpair[r - 100*q];
195 buf += 2;
196
197 /* 1 <= q < 10^6 */
198 if (q < 100)
199 goto out_q;
200
201 /* 100 <= q < 10^6 */
202 r = (q * (u64)0x28f5c29) >> 32;
203 *((u16 *)buf) = decpair[q - 100*r];
204 buf += 2;
205
206 /* 1 <= r < 10^4 */
207 if (r < 100)
208 goto out_r;
209
210 /* 100 <= r < 10^4 */
211 q = (r * 0x147b) >> 19;
212 *((u16 *)buf) = decpair[r - 100*q];
213 buf += 2;
214 out_q:
215 /* 1 <= q < 100 */
216 r = q;
217 out_r:
218 /* 1 <= r < 100 */
219 *((u16 *)buf) = decpair[r];
220 buf += r < 10 ? 1 : 2;
221 return buf;
222 }
223
224 #if BITS_PER_LONG == 64 && BITS_PER_LONG_LONG == 64
225 static noinline_for_stack
226 char *put_dec_full8(char *buf, unsigned r)
227 {
228 unsigned q;
229
230 /* 0 <= r < 10^8 */
231 q = (r * (u64)0x28f5c29) >> 32;
232 *((u16 *)buf) = decpair[r - 100*q];
233 buf += 2;
234
235 /* 0 <= q < 10^6 */
236 r = (q * (u64)0x28f5c29) >> 32;
237 *((u16 *)buf) = decpair[q - 100*r];
238 buf += 2;
239
240 /* 0 <= r < 10^4 */
241 q = (r * 0x147b) >> 19;
242 *((u16 *)buf) = decpair[r - 100*q];
243 buf += 2;
244
245 /* 0 <= q < 100 */
246 *((u16 *)buf) = decpair[q];
247 buf += 2;
248 return buf;
249 }
250
251 static noinline_for_stack
252 char *put_dec(char *buf, unsigned long long n)
253 {
254 if (n >= 100*1000*1000)
255 buf = put_dec_full8(buf, do_div(n, 100*1000*1000));
256 /* 1 <= n <= 1.6e11 */
257 if (n >= 100*1000*1000)
258 buf = put_dec_full8(buf, do_div(n, 100*1000*1000));
259 /* 1 <= n < 1e8 */
260 return put_dec_trunc8(buf, n);
261 }
262
263 #elif BITS_PER_LONG == 32 && BITS_PER_LONG_LONG == 64
264
265 static void
266 put_dec_full4(char *buf, unsigned r)
267 {
268 unsigned q;
269
270 /* 0 <= r < 10^4 */
271 q = (r * 0x147b) >> 19;
272 *((u16 *)buf) = decpair[r - 100*q];
273 buf += 2;
274 /* 0 <= q < 100 */
275 *((u16 *)buf) = decpair[q];
276 }
277
278 /*
279 * Call put_dec_full4 on x % 10000, return x / 10000.
280 * The approximation x/10000 == (x * 0x346DC5D7) >> 43
281 * holds for all x < 1,128,869,999. The largest value this
282 * helper will ever be asked to convert is 1,125,520,955.
283 * (second call in the put_dec code, assuming n is all-ones).
284 */
285 static noinline_for_stack
286 unsigned put_dec_helper4(char *buf, unsigned x)
287 {
288 uint32_t q = (x * (uint64_t)0x346DC5D7) >> 43;
289
290 put_dec_full4(buf, x - q * 10000);
291 return q;
292 }
293
294 /* Based on code by Douglas W. Jones found at
295 * <http://www.cs.uiowa.edu/~jones/bcd/decimal.html#sixtyfour>
296 * (with permission from the author).
297 * Performs no 64-bit division and hence should be fast on 32-bit machines.
298 */
299 static
300 char *put_dec(char *buf, unsigned long long n)
301 {
302 uint32_t d3, d2, d1, q, h;
303
304 if (n < 100*1000*1000)
305 return put_dec_trunc8(buf, n);
306
307 d1 = ((uint32_t)n >> 16); /* implicit "& 0xffff" */
308 h = (n >> 32);
309 d2 = (h ) & 0xffff;
310 d3 = (h >> 16); /* implicit "& 0xffff" */
311
312 /* n = 2^48 d3 + 2^32 d2 + 2^16 d1 + d0
313 = 281_4749_7671_0656 d3 + 42_9496_7296 d2 + 6_5536 d1 + d0 */
314 q = 656 * d3 + 7296 * d2 + 5536 * d1 + ((uint32_t)n & 0xffff);
315 q = put_dec_helper4(buf, q);
316
317 q += 7671 * d3 + 9496 * d2 + 6 * d1;
318 q = put_dec_helper4(buf+4, q);
319
320 q += 4749 * d3 + 42 * d2;
321 q = put_dec_helper4(buf+8, q);
322
323 q += 281 * d3;
324 buf += 12;
325 if (q)
326 buf = put_dec_trunc8(buf, q);
327 else while (buf[-1] == '0')
328 --buf;
329
330 return buf;
331 }
332
333 #endif
334
335 /*
336 * Convert passed number to decimal string.
337 * Returns the length of string. On buffer overflow, returns 0.
338 *
339 * If speed is not important, use snprintf(). It's easy to read the code.
340 */
341 int num_to_str(char *buf, int size, unsigned long long num, unsigned int width)
342 {
343 /* put_dec requires 2-byte alignment of the buffer. */
344 char tmp[sizeof(num) * 3] __aligned(2);
345 int idx, len;
346
347 /* put_dec() may work incorrectly for num = 0 (generate "", not "0") */
348 if (num <= 9) {
349 tmp[0] = '0' + num;
350 len = 1;
351 } else {
352 len = put_dec(tmp, num) - tmp;
353 }
354
355 if (len > size || width > size)
356 return 0;
357
358 if (width > len) {
359 width = width - len;
360 for (idx = 0; idx < width; idx++)
361 buf[idx] = ' ';
362 } else {
363 width = 0;
364 }
365
366 for (idx = 0; idx < len; ++idx)
367 buf[idx + width] = tmp[len - idx - 1];
368
369 return len + width;
370 }
371
372 #define SIGN 1 /* unsigned/signed, must be 1 */
373 #define LEFT 2 /* left justified */
374 #define PLUS 4 /* show plus */
375 #define SPACE 8 /* space if plus */
376 #define ZEROPAD 16 /* pad with zero, must be 16 == '0' - ' ' */
377 #define SMALL 32 /* use lowercase in hex (must be 32 == 0x20) */
378 #define SPECIAL 64 /* prefix hex with "0x", octal with "0" */
379
380 enum format_type {
381 FORMAT_TYPE_NONE, /* Just a string part */
382 FORMAT_TYPE_WIDTH,
383 FORMAT_TYPE_PRECISION,
384 FORMAT_TYPE_CHAR,
385 FORMAT_TYPE_STR,
386 FORMAT_TYPE_PTR,
387 FORMAT_TYPE_PERCENT_CHAR,
388 FORMAT_TYPE_INVALID,
389 FORMAT_TYPE_LONG_LONG,
390 FORMAT_TYPE_ULONG,
391 FORMAT_TYPE_LONG,
392 FORMAT_TYPE_UBYTE,
393 FORMAT_TYPE_BYTE,
394 FORMAT_TYPE_USHORT,
395 FORMAT_TYPE_SHORT,
396 FORMAT_TYPE_UINT,
397 FORMAT_TYPE_INT,
398 FORMAT_TYPE_SIZE_T,
399 FORMAT_TYPE_PTRDIFF
400 };
401
402 struct printf_spec {
403 unsigned int type:8; /* format_type enum */
404 signed int field_width:24; /* width of output field */
405 unsigned int flags:8; /* flags to number() */
406 unsigned int base:8; /* number base, 8, 10 or 16 only */
407 signed int precision:16; /* # of digits/chars */
408 } __packed;
409 static_assert(sizeof(struct printf_spec) == 8);
410
411 #define FIELD_WIDTH_MAX ((1 << 23) - 1)
412 #define PRECISION_MAX ((1 << 15) - 1)
413
414 static noinline_for_stack
415 char *number(char *buf, char *end, unsigned long long num,
416 struct printf_spec spec)
417 {
418 /* put_dec requires 2-byte alignment of the buffer. */
419 char tmp[3 * sizeof(num)] __aligned(2);
420 char sign;
421 char locase;
422 int need_pfx = ((spec.flags & SPECIAL) && spec.base != 10);
423 int i;
424 bool is_zero = num == 0LL;
425 int field_width = spec.field_width;
426 int precision = spec.precision;
427
428 /* locase = 0 or 0x20. ORing digits or letters with 'locase'
429 * produces same digits or (maybe lowercased) letters */
430 locase = (spec.flags & SMALL);
431 if (spec.flags & LEFT)
432 spec.flags &= ~ZEROPAD;
433 sign = 0;
434 if (spec.flags & SIGN) {
435 if ((signed long long)num < 0) {
436 sign = '-';
437 num = -(signed long long)num;
438 field_width--;
439 } else if (spec.flags & PLUS) {
440 sign = '+';
441 field_width--;
442 } else if (spec.flags & SPACE) {
443 sign = ' ';
444 field_width--;
445 }
446 }
447 if (need_pfx) {
448 if (spec.base == 16)
449 field_width -= 2;
450 else if (!is_zero)
451 field_width--;
452 }
453
454 /* generate full string in tmp[], in reverse order */
455 i = 0;
456 if (num < spec.base)
457 tmp[i++] = hex_asc_upper[num] | locase;
458 else if (spec.base != 10) { /* 8 or 16 */
459 int mask = spec.base - 1;
460 int shift = 3;
461
462 if (spec.base == 16)
463 shift = 4;
464 do {
465 tmp[i++] = (hex_asc_upper[((unsigned char)num) & mask] | locase);
466 num >>= shift;
467 } while (num);
468 } else { /* base 10 */
469 i = put_dec(tmp, num) - tmp;
470 }
471
472 /* printing 100 using %2d gives "100", not "00" */
473 if (i > precision)
474 precision = i;
475 /* leading space padding */
476 field_width -= precision;
477 if (!(spec.flags & (ZEROPAD | LEFT))) {
478 while (--field_width >= 0) {
479 if (buf < end)
480 *buf = ' ';
481 ++buf;
482 }
483 }
484 /* sign */
485 if (sign) {
486 if (buf < end)
487 *buf = sign;
488 ++buf;
489 }
490 /* "0x" / "0" prefix */
491 if (need_pfx) {
492 if (spec.base == 16 || !is_zero) {
493 if (buf < end)
494 *buf = '0';
495 ++buf;
496 }
497 if (spec.base == 16) {
498 if (buf < end)
499 *buf = ('X' | locase);
500 ++buf;
501 }
502 }
503 /* zero or space padding */
504 if (!(spec.flags & LEFT)) {
505 char c = ' ' + (spec.flags & ZEROPAD);
506 BUILD_BUG_ON(' ' + ZEROPAD != '0');
507 while (--field_width >= 0) {
508 if (buf < end)
509 *buf = c;
510 ++buf;
511 }
512 }
513 /* hmm even more zero padding? */
514 while (i <= --precision) {
515 if (buf < end)
516 *buf = '0';
517 ++buf;
518 }
519 /* actual digits of result */
520 while (--i >= 0) {
521 if (buf < end)
522 *buf = tmp[i];
523 ++buf;
524 }
525 /* trailing space padding */
526 while (--field_width >= 0) {
527 if (buf < end)
528 *buf = ' ';
529 ++buf;
530 }
531
532 return buf;
533 }
534
535 static noinline_for_stack
536 char *special_hex_number(char *buf, char *end, unsigned long long num, int size)
537 {
538 struct printf_spec spec;
539
540 spec.type = FORMAT_TYPE_PTR;
541 spec.field_width = 2 + 2 * size; /* 0x + hex */
542 spec.flags = SPECIAL | SMALL | ZEROPAD;
543 spec.base = 16;
544 spec.precision = -1;
545
546 return number(buf, end, num, spec);
547 }
548
549 static void move_right(char *buf, char *end, unsigned len, unsigned spaces)
550 {
551 size_t size;
552 if (buf >= end) /* nowhere to put anything */
553 return;
554 size = end - buf;
555 if (size <= spaces) {
556 memset(buf, ' ', size);
557 return;
558 }
559 if (len) {
560 if (len > size - spaces)
561 len = size - spaces;
562 memmove(buf + spaces, buf, len);
563 }
564 memset(buf, ' ', spaces);
565 }
566
567 /*
568 * Handle field width padding for a string.
569 * @buf: current buffer position
570 * @n: length of string
571 * @end: end of output buffer
572 * @spec: for field width and flags
573 * Returns: new buffer position after padding.
574 */
575 static noinline_for_stack
576 char *widen_string(char *buf, int n, char *end, struct printf_spec spec)
577 {
578 unsigned spaces;
579
580 if (likely(n >= spec.field_width))
581 return buf;
582 /* we want to pad the sucker */
583 spaces = spec.field_width - n;
584 if (!(spec.flags & LEFT)) {
585 move_right(buf - n, end, n, spaces);
586 return buf + spaces;
587 }
588 while (spaces--) {
589 if (buf < end)
590 *buf = ' ';
591 ++buf;
592 }
593 return buf;
594 }
595
596 static noinline_for_stack
597 char *string(char *buf, char *end, const char *s, struct printf_spec spec)
598 {
599 int len = 0;
600 size_t lim = spec.precision;
601
602 if ((unsigned long)s < PAGE_SIZE)
603 s = "(null)";
604
605 while (lim--) {
606 char c = *s++;
607 if (!c)
608 break;
609 if (buf < end)
610 *buf = c;
611 ++buf;
612 ++len;
613 }
614 return widen_string(buf, len, end, spec);
615 }
616
617 static noinline_for_stack
618 char *pointer_string(char *buf, char *end, const void *ptr,
619 struct printf_spec spec)
620 {
621 spec.base = 16;
622 spec.flags |= SMALL;
623 if (spec.field_width == -1) {
624 spec.field_width = 2 * sizeof(ptr);
625 spec.flags |= ZEROPAD;
626 }
627
628 return number(buf, end, (unsigned long int)ptr, spec);
629 }
630
631 /* Make pointers available for printing early in the boot sequence. */
632 static int debug_boot_weak_hash __ro_after_init;
633
634 static int __init debug_boot_weak_hash_enable(char *str)
635 {
636 debug_boot_weak_hash = 1;
637 pr_info("debug_boot_weak_hash enabled\n");
638 return 0;
639 }
640 early_param("debug_boot_weak_hash", debug_boot_weak_hash_enable);
641
642 static DEFINE_STATIC_KEY_TRUE(not_filled_random_ptr_key);
643 static siphash_key_t ptr_key __read_mostly;
644
645 static void enable_ptr_key_workfn(struct work_struct *work)
646 {
647 get_random_bytes(&ptr_key, sizeof(ptr_key));
648 /* Needs to run from preemptible context */
649 static_branch_disable(&not_filled_random_ptr_key);
650 }
651
652 static DECLARE_WORK(enable_ptr_key_work, enable_ptr_key_workfn);
653
654 static void fill_random_ptr_key(struct random_ready_callback *unused)
655 {
656 /* This may be in an interrupt handler. */
657 queue_work(system_unbound_wq, &enable_ptr_key_work);
658 }
659
660 static struct random_ready_callback random_ready = {
661 .func = fill_random_ptr_key
662 };
663
664 static int __init initialize_ptr_random(void)
665 {
666 int key_size = sizeof(ptr_key);
667 int ret;
668
669 /* Use hw RNG if available. */
670 if (get_random_bytes_arch(&ptr_key, key_size) == key_size) {
671 static_branch_disable(&not_filled_random_ptr_key);
672 return 0;
673 }
674
675 ret = add_random_ready_callback(&random_ready);
676 if (!ret) {
677 return 0;
678 } else if (ret == -EALREADY) {
679 /* This is in preemptible context */
680 enable_ptr_key_workfn(&enable_ptr_key_work);
681 return 0;
682 }
683
684 return ret;
685 }
686 early_initcall(initialize_ptr_random);
687
688 /* Maps a pointer to a 32 bit unique identifier. */
689 static char *ptr_to_id(char *buf, char *end, const void *ptr,
690 struct printf_spec spec)
691 {
692 const char *str = sizeof(ptr) == 8 ? "(____ptrval____)" : "(ptrval)";
693 unsigned long hashval;
694
695 /* When debugging early boot use non-cryptographically secure hash. */
696 if (unlikely(debug_boot_weak_hash)) {
697 hashval = hash_long((unsigned long)ptr, 32);
698 return pointer_string(buf, end, (const void *)hashval, spec);
699 }
700
701 if (static_branch_unlikely(&not_filled_random_ptr_key)) {
702 spec.field_width = 2 * sizeof(ptr);
703 /* string length must be less than default_width */
704 return string(buf, end, str, spec);
705 }
706
707 #ifdef CONFIG_64BIT
708 hashval = (unsigned long)siphash_1u64((u64)ptr, &ptr_key);
709 /*
710 * Mask off the first 32 bits, this makes explicit that we have
711 * modified the address (and 32 bits is plenty for a unique ID).
712 */
713 hashval = hashval & 0xffffffff;
714 #else
715 hashval = (unsigned long)siphash_1u32((u32)ptr, &ptr_key);
716 #endif
717 return pointer_string(buf, end, (const void *)hashval, spec);
718 }
719
720 static noinline_for_stack
721 char *dentry_name(char *buf, char *end, const struct dentry *d, struct printf_spec spec,
722 const char *fmt)
723 {
724 const char *array[4], *s;
725 const struct dentry *p;
726 int depth;
727 int i, n;
728
729 switch (fmt[1]) {
730 case '2': case '3': case '4':
731 depth = fmt[1] - '0';
732 break;
733 default:
734 depth = 1;
735 }
736
737 rcu_read_lock();
738 for (i = 0; i < depth; i++, d = p) {
739 p = READ_ONCE(d->d_parent);
740 array[i] = READ_ONCE(d->d_name.name);
741 if (p == d) {
742 if (i)
743 array[i] = "";
744 i++;
745 break;
746 }
747 }
748 s = array[--i];
749 for (n = 0; n != spec.precision; n++, buf++) {
750 char c = *s++;
751 if (!c) {
752 if (!i)
753 break;
754 c = '/';
755 s = array[--i];
756 }
757 if (buf < end)
758 *buf = c;
759 }
760 rcu_read_unlock();
761 return widen_string(buf, n, end, spec);
762 }
763
764 #ifdef CONFIG_BLOCK
765 static noinline_for_stack
766 char *bdev_name(char *buf, char *end, struct block_device *bdev,
767 struct printf_spec spec, const char *fmt)
768 {
769 struct gendisk *hd = bdev->bd_disk;
770
771 buf = string(buf, end, hd->disk_name, spec);
772 if (bdev->bd_part->partno) {
773 if (isdigit(hd->disk_name[strlen(hd->disk_name)-1])) {
774 if (buf < end)
775 *buf = 'p';
776 buf++;
777 }
778 buf = number(buf, end, bdev->bd_part->partno, spec);
779 }
780 return buf;
781 }
782 #endif
783
784 static noinline_for_stack
785 char *symbol_string(char *buf, char *end, void *ptr,
786 struct printf_spec spec, const char *fmt)
787 {
788 unsigned long value;
789 #ifdef CONFIG_KALLSYMS
790 char sym[KSYM_SYMBOL_LEN];
791 #endif
792
793 if (fmt[1] == 'R')
794 ptr = __builtin_extract_return_addr(ptr);
795 value = (unsigned long)ptr;
796
797 #ifdef CONFIG_KALLSYMS
798 if (*fmt == 'B')
799 sprint_backtrace(sym, value);
800 else if (*fmt != 'f' && *fmt != 's')
801 sprint_symbol(sym, value);
802 else
803 sprint_symbol_no_offset(sym, value);
804
805 return string(buf, end, sym, spec);
806 #else
807 return special_hex_number(buf, end, value, sizeof(void *));
808 #endif
809 }
810
811 static const struct printf_spec default_str_spec = {
812 .field_width = -1,
813 .precision = -1,
814 };
815
816 static const struct printf_spec default_flag_spec = {
817 .base = 16,
818 .precision = -1,
819 .flags = SPECIAL | SMALL,
820 };
821
822 static const struct printf_spec default_dec_spec = {
823 .base = 10,
824 .precision = -1,
825 };
826
827 static const struct printf_spec default_dec02_spec = {
828 .base = 10,
829 .field_width = 2,
830 .precision = -1,
831 .flags = ZEROPAD,
832 };
833
834 static const struct printf_spec default_dec04_spec = {
835 .base = 10,
836 .field_width = 4,
837 .precision = -1,
838 .flags = ZEROPAD,
839 };
840
841 static noinline_for_stack
842 char *resource_string(char *buf, char *end, struct resource *res,
843 struct printf_spec spec, const char *fmt)
844 {
845 #ifndef IO_RSRC_PRINTK_SIZE
846 #define IO_RSRC_PRINTK_SIZE 6
847 #endif
848
849 #ifndef MEM_RSRC_PRINTK_SIZE
850 #define MEM_RSRC_PRINTK_SIZE 10
851 #endif
852 static const struct printf_spec io_spec = {
853 .base = 16,
854 .field_width = IO_RSRC_PRINTK_SIZE,
855 .precision = -1,
856 .flags = SPECIAL | SMALL | ZEROPAD,
857 };
858 static const struct printf_spec mem_spec = {
859 .base = 16,
860 .field_width = MEM_RSRC_PRINTK_SIZE,
861 .precision = -1,
862 .flags = SPECIAL | SMALL | ZEROPAD,
863 };
864 static const struct printf_spec bus_spec = {
865 .base = 16,
866 .field_width = 2,
867 .precision = -1,
868 .flags = SMALL | ZEROPAD,
869 };
870 static const struct printf_spec str_spec = {
871 .field_width = -1,
872 .precision = 10,
873 .flags = LEFT,
874 };
875
876 /* 32-bit res (sizeof==4): 10 chars in dec, 10 in hex ("0x" + 8)
877 * 64-bit res (sizeof==8): 20 chars in dec, 18 in hex ("0x" + 16) */
878 #define RSRC_BUF_SIZE ((2 * sizeof(resource_size_t)) + 4)
879 #define FLAG_BUF_SIZE (2 * sizeof(res->flags))
880 #define DECODED_BUF_SIZE sizeof("[mem - 64bit pref window disabled]")
881 #define RAW_BUF_SIZE sizeof("[mem - flags 0x]")
882 char sym[max(2*RSRC_BUF_SIZE + DECODED_BUF_SIZE,
883 2*RSRC_BUF_SIZE + FLAG_BUF_SIZE + RAW_BUF_SIZE)];
884
885 char *p = sym, *pend = sym + sizeof(sym);
886 int decode = (fmt[0] == 'R') ? 1 : 0;
887 const struct printf_spec *specp;
888
889 *p++ = '[';
890 if (res->flags & IORESOURCE_IO) {
891 p = string(p, pend, "io ", str_spec);
892 specp = &io_spec;
893 } else if (res->flags & IORESOURCE_MEM) {
894 p = string(p, pend, "mem ", str_spec);
895 specp = &mem_spec;
896 } else if (res->flags & IORESOURCE_IRQ) {
897 p = string(p, pend, "irq ", str_spec);
898 specp = &default_dec_spec;
899 } else if (res->flags & IORESOURCE_DMA) {
900 p = string(p, pend, "dma ", str_spec);
901 specp = &default_dec_spec;
902 } else if (res->flags & IORESOURCE_BUS) {
903 p = string(p, pend, "bus ", str_spec);
904 specp = &bus_spec;
905 } else {
906 p = string(p, pend, "??? ", str_spec);
907 specp = &mem_spec;
908 decode = 0;
909 }
910 if (decode && res->flags & IORESOURCE_UNSET) {
911 p = string(p, pend, "size ", str_spec);
912 p = number(p, pend, resource_size(res), *specp);
913 } else {
914 p = number(p, pend, res->start, *specp);
915 if (res->start != res->end) {
916 *p++ = '-';
917 p = number(p, pend, res->end, *specp);
918 }
919 }
920 if (decode) {
921 if (res->flags & IORESOURCE_MEM_64)
922 p = string(p, pend, " 64bit", str_spec);
923 if (res->flags & IORESOURCE_PREFETCH)
924 p = string(p, pend, " pref", str_spec);
925 if (res->flags & IORESOURCE_WINDOW)
926 p = string(p, pend, " window", str_spec);
927 if (res->flags & IORESOURCE_DISABLED)
928 p = string(p, pend, " disabled", str_spec);
929 } else {
930 p = string(p, pend, " flags ", str_spec);
931 p = number(p, pend, res->flags, default_flag_spec);
932 }
933 *p++ = ']';
934 *p = '\0';
935
936 return string(buf, end, sym, spec);
937 }
938
939 static noinline_for_stack
940 char *hex_string(char *buf, char *end, u8 *addr, struct printf_spec spec,
941 const char *fmt)
942 {
943 int i, len = 1; /* if we pass '%ph[CDN]', field width remains
944 negative value, fallback to the default */
945 char separator;
946
947 if (spec.field_width == 0)
948 /* nothing to print */
949 return buf;
950
951 if (ZERO_OR_NULL_PTR(addr))
952 /* NULL pointer */
953 return string(buf, end, NULL, spec);
954
955 switch (fmt[1]) {
956 case 'C':
957 separator = ':';
958 break;
959 case 'D':
960 separator = '-';
961 break;
962 case 'N':
963 separator = 0;
964 break;
965 default:
966 separator = ' ';
967 break;
968 }
969
970 if (spec.field_width > 0)
971 len = min_t(int, spec.field_width, 64);
972
973 for (i = 0; i < len; ++i) {
974 if (buf < end)
975 *buf = hex_asc_hi(addr[i]);
976 ++buf;
977 if (buf < end)
978 *buf = hex_asc_lo(addr[i]);
979 ++buf;
980
981 if (separator && i != len - 1) {
982 if (buf < end)
983 *buf = separator;
984 ++buf;
985 }
986 }
987
988 return buf;
989 }
990
991 static noinline_for_stack
992 char *bitmap_string(char *buf, char *end, unsigned long *bitmap,
993 struct printf_spec spec, const char *fmt)
994 {
995 const int CHUNKSZ = 32;
996 int nr_bits = max_t(int, spec.field_width, 0);
997 int i, chunksz;
998 bool first = true;
999
1000 /* reused to print numbers */
1001 spec = (struct printf_spec){ .flags = SMALL | ZEROPAD, .base = 16 };
1002
1003 chunksz = nr_bits & (CHUNKSZ - 1);
1004 if (chunksz == 0)
1005 chunksz = CHUNKSZ;
1006
1007 i = ALIGN(nr_bits, CHUNKSZ) - CHUNKSZ;
1008 for (; i >= 0; i -= CHUNKSZ) {
1009 u32 chunkmask, val;
1010 int word, bit;
1011
1012 chunkmask = ((1ULL << chunksz) - 1);
1013 word = i / BITS_PER_LONG;
1014 bit = i % BITS_PER_LONG;
1015 val = (bitmap[word] >> bit) & chunkmask;
1016
1017 if (!first) {
1018 if (buf < end)
1019 *buf = ',';
1020 buf++;
1021 }
1022 first = false;
1023
1024 spec.field_width = DIV_ROUND_UP(chunksz, 4);
1025 buf = number(buf, end, val, spec);
1026
1027 chunksz = CHUNKSZ;
1028 }
1029 return buf;
1030 }
1031
1032 static noinline_for_stack
1033 char *bitmap_list_string(char *buf, char *end, unsigned long *bitmap,
1034 struct printf_spec spec, const char *fmt)
1035 {
1036 int nr_bits = max_t(int, spec.field_width, 0);
1037 /* current bit is 'cur', most recently seen range is [rbot, rtop] */
1038 int cur, rbot, rtop;
1039 bool first = true;
1040
1041 rbot = cur = find_first_bit(bitmap, nr_bits);
1042 while (cur < nr_bits) {
1043 rtop = cur;
1044 cur = find_next_bit(bitmap, nr_bits, cur + 1);
1045 if (cur < nr_bits && cur <= rtop + 1)
1046 continue;
1047
1048 if (!first) {
1049 if (buf < end)
1050 *buf = ',';
1051 buf++;
1052 }
1053 first = false;
1054
1055 buf = number(buf, end, rbot, default_dec_spec);
1056 if (rbot < rtop) {
1057 if (buf < end)
1058 *buf = '-';
1059 buf++;
1060
1061 buf = number(buf, end, rtop, default_dec_spec);
1062 }
1063
1064 rbot = cur;
1065 }
1066 return buf;
1067 }
1068
1069 static noinline_for_stack
1070 char *mac_address_string(char *buf, char *end, u8 *addr,
1071 struct printf_spec spec, const char *fmt)
1072 {
1073 char mac_addr[sizeof("xx:xx:xx:xx:xx:xx")];
1074 char *p = mac_addr;
1075 int i;
1076 char separator;
1077 bool reversed = false;
1078
1079 switch (fmt[1]) {
1080 case 'F':
1081 separator = '-';
1082 break;
1083
1084 case 'R':
1085 reversed = true;
1086 /* fall through */
1087
1088 default:
1089 separator = ':';
1090 break;
1091 }
1092
1093 for (i = 0; i < 6; i++) {
1094 if (reversed)
1095 p = hex_byte_pack(p, addr[5 - i]);
1096 else
1097 p = hex_byte_pack(p, addr[i]);
1098
1099 if (fmt[0] == 'M' && i != 5)
1100 *p++ = separator;
1101 }
1102 *p = '\0';
1103
1104 return string(buf, end, mac_addr, spec);
1105 }
1106
1107 static noinline_for_stack
1108 char *ip4_string(char *p, const u8 *addr, const char *fmt)
1109 {
1110 int i;
1111 bool leading_zeros = (fmt[0] == 'i');
1112 int index;
1113 int step;
1114
1115 switch (fmt[2]) {
1116 case 'h':
1117 #ifdef __BIG_ENDIAN
1118 index = 0;
1119 step = 1;
1120 #else
1121 index = 3;
1122 step = -1;
1123 #endif
1124 break;
1125 case 'l':
1126 index = 3;
1127 step = -1;
1128 break;
1129 case 'n':
1130 case 'b':
1131 default:
1132 index = 0;
1133 step = 1;
1134 break;
1135 }
1136 for (i = 0; i < 4; i++) {
1137 char temp[4] __aligned(2); /* hold each IP quad in reverse order */
1138 int digits = put_dec_trunc8(temp, addr[index]) - temp;
1139 if (leading_zeros) {
1140 if (digits < 3)
1141 *p++ = '0';
1142 if (digits < 2)
1143 *p++ = '0';
1144 }
1145 /* reverse the digits in the quad */
1146 while (digits--)
1147 *p++ = temp[digits];
1148 if (i < 3)
1149 *p++ = '.';
1150 index += step;
1151 }
1152 *p = '\0';
1153
1154 return p;
1155 }
1156
1157 static noinline_for_stack
1158 char *ip6_compressed_string(char *p, const char *addr)
1159 {
1160 int i, j, range;
1161 unsigned char zerolength[8];
1162 int longest = 1;
1163 int colonpos = -1;
1164 u16 word;
1165 u8 hi, lo;
1166 bool needcolon = false;
1167 bool useIPv4;
1168 struct in6_addr in6;
1169
1170 memcpy(&in6, addr, sizeof(struct in6_addr));
1171
1172 useIPv4 = ipv6_addr_v4mapped(&in6) || ipv6_addr_is_isatap(&in6);
1173
1174 memset(zerolength, 0, sizeof(zerolength));
1175
1176 if (useIPv4)
1177 range = 6;
1178 else
1179 range = 8;
1180
1181 /* find position of longest 0 run */
1182 for (i = 0; i < range; i++) {
1183 for (j = i; j < range; j++) {
1184 if (in6.s6_addr16[j] != 0)
1185 break;
1186 zerolength[i]++;
1187 }
1188 }
1189 for (i = 0; i < range; i++) {
1190 if (zerolength[i] > longest) {
1191 longest = zerolength[i];
1192 colonpos = i;
1193 }
1194 }
1195 if (longest == 1) /* don't compress a single 0 */
1196 colonpos = -1;
1197
1198 /* emit address */
1199 for (i = 0; i < range; i++) {
1200 if (i == colonpos) {
1201 if (needcolon || i == 0)
1202 *p++ = ':';
1203 *p++ = ':';
1204 needcolon = false;
1205 i += longest - 1;
1206 continue;
1207 }
1208 if (needcolon) {
1209 *p++ = ':';
1210 needcolon = false;
1211 }
1212 /* hex u16 without leading 0s */
1213 word = ntohs(in6.s6_addr16[i]);
1214 hi = word >> 8;
1215 lo = word & 0xff;
1216 if (hi) {
1217 if (hi > 0x0f)
1218 p = hex_byte_pack(p, hi);
1219 else
1220 *p++ = hex_asc_lo(hi);
1221 p = hex_byte_pack(p, lo);
1222 }
1223 else if (lo > 0x0f)
1224 p = hex_byte_pack(p, lo);
1225 else
1226 *p++ = hex_asc_lo(lo);
1227 needcolon = true;
1228 }
1229
1230 if (useIPv4) {
1231 if (needcolon)
1232 *p++ = ':';
1233 p = ip4_string(p, &in6.s6_addr[12], "I4");
1234 }
1235 *p = '\0';
1236
1237 return p;
1238 }
1239
1240 static noinline_for_stack
1241 char *ip6_string(char *p, const char *addr, const char *fmt)
1242 {
1243 int i;
1244
1245 for (i = 0; i < 8; i++) {
1246 p = hex_byte_pack(p, *addr++);
1247 p = hex_byte_pack(p, *addr++);
1248 if (fmt[0] == 'I' && i != 7)
1249 *p++ = ':';
1250 }
1251 *p = '\0';
1252
1253 return p;
1254 }
1255
1256 static noinline_for_stack
1257 char *ip6_addr_string(char *buf, char *end, const u8 *addr,
1258 struct printf_spec spec, const char *fmt)
1259 {
1260 char ip6_addr[sizeof("xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255")];
1261
1262 if (fmt[0] == 'I' && fmt[2] == 'c')
1263 ip6_compressed_string(ip6_addr, addr);
1264 else
1265 ip6_string(ip6_addr, addr, fmt);
1266
1267 return string(buf, end, ip6_addr, spec);
1268 }
1269
1270 static noinline_for_stack
1271 char *ip4_addr_string(char *buf, char *end, const u8 *addr,
1272 struct printf_spec spec, const char *fmt)
1273 {
1274 char ip4_addr[sizeof("255.255.255.255")];
1275
1276 ip4_string(ip4_addr, addr, fmt);
1277
1278 return string(buf, end, ip4_addr, spec);
1279 }
1280
1281 static noinline_for_stack
1282 char *ip6_addr_string_sa(char *buf, char *end, const struct sockaddr_in6 *sa,
1283 struct printf_spec spec, const char *fmt)
1284 {
1285 bool have_p = false, have_s = false, have_f = false, have_c = false;
1286 char ip6_addr[sizeof("[xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255]") +
1287 sizeof(":12345") + sizeof("/123456789") +
1288 sizeof("%1234567890")];
1289 char *p = ip6_addr, *pend = ip6_addr + sizeof(ip6_addr);
1290 const u8 *addr = (const u8 *) &sa->sin6_addr;
1291 char fmt6[2] = { fmt[0], '6' };
1292 u8 off = 0;
1293
1294 fmt++;
1295 while (isalpha(*++fmt)) {
1296 switch (*fmt) {
1297 case 'p':
1298 have_p = true;
1299 break;
1300 case 'f':
1301 have_f = true;
1302 break;
1303 case 's':
1304 have_s = true;
1305 break;
1306 case 'c':
1307 have_c = true;
1308 break;
1309 }
1310 }
1311
1312 if (have_p || have_s || have_f) {
1313 *p = '[';
1314 off = 1;
1315 }
1316
1317 if (fmt6[0] == 'I' && have_c)
1318 p = ip6_compressed_string(ip6_addr + off, addr);
1319 else
1320 p = ip6_string(ip6_addr + off, addr, fmt6);
1321
1322 if (have_p || have_s || have_f)
1323 *p++ = ']';
1324
1325 if (have_p) {
1326 *p++ = ':';
1327 p = number(p, pend, ntohs(sa->sin6_port), spec);
1328 }
1329 if (have_f) {
1330 *p++ = '/';
1331 p = number(p, pend, ntohl(sa->sin6_flowinfo &
1332 IPV6_FLOWINFO_MASK), spec);
1333 }
1334 if (have_s) {
1335 *p++ = '%';
1336 p = number(p, pend, sa->sin6_scope_id, spec);
1337 }
1338 *p = '\0';
1339
1340 return string(buf, end, ip6_addr, spec);
1341 }
1342
1343 static noinline_for_stack
1344 char *ip4_addr_string_sa(char *buf, char *end, const struct sockaddr_in *sa,
1345 struct printf_spec spec, const char *fmt)
1346 {
1347 bool have_p = false;
1348 char *p, ip4_addr[sizeof("255.255.255.255") + sizeof(":12345")];
1349 char *pend = ip4_addr + sizeof(ip4_addr);
1350 const u8 *addr = (const u8 *) &sa->sin_addr.s_addr;
1351 char fmt4[3] = { fmt[0], '4', 0 };
1352
1353 fmt++;
1354 while (isalpha(*++fmt)) {
1355 switch (*fmt) {
1356 case 'p':
1357 have_p = true;
1358 break;
1359 case 'h':
1360 case 'l':
1361 case 'n':
1362 case 'b':
1363 fmt4[2] = *fmt;
1364 break;
1365 }
1366 }
1367
1368 p = ip4_string(ip4_addr, addr, fmt4);
1369 if (have_p) {
1370 *p++ = ':';
1371 p = number(p, pend, ntohs(sa->sin_port), spec);
1372 }
1373 *p = '\0';
1374
1375 return string(buf, end, ip4_addr, spec);
1376 }
1377
1378 static noinline_for_stack
1379 char *escaped_string(char *buf, char *end, u8 *addr, struct printf_spec spec,
1380 const char *fmt)
1381 {
1382 bool found = true;
1383 int count = 1;
1384 unsigned int flags = 0;
1385 int len;
1386
1387 if (spec.field_width == 0)
1388 return buf; /* nothing to print */
1389
1390 if (ZERO_OR_NULL_PTR(addr))
1391 return string(buf, end, NULL, spec); /* NULL pointer */
1392
1393
1394 do {
1395 switch (fmt[count++]) {
1396 case 'a':
1397 flags |= ESCAPE_ANY;
1398 break;
1399 case 'c':
1400 flags |= ESCAPE_SPECIAL;
1401 break;
1402 case 'h':
1403 flags |= ESCAPE_HEX;
1404 break;
1405 case 'n':
1406 flags |= ESCAPE_NULL;
1407 break;
1408 case 'o':
1409 flags |= ESCAPE_OCTAL;
1410 break;
1411 case 'p':
1412 flags |= ESCAPE_NP;
1413 break;
1414 case 's':
1415 flags |= ESCAPE_SPACE;
1416 break;
1417 default:
1418 found = false;
1419 break;
1420 }
1421 } while (found);
1422
1423 if (!flags)
1424 flags = ESCAPE_ANY_NP;
1425
1426 len = spec.field_width < 0 ? 1 : spec.field_width;
1427
1428 /*
1429 * string_escape_mem() writes as many characters as it can to
1430 * the given buffer, and returns the total size of the output
1431 * had the buffer been big enough.
1432 */
1433 buf += string_escape_mem(addr, len, buf, buf < end ? end - buf : 0, flags, NULL);
1434
1435 return buf;
1436 }
1437
1438 static noinline_for_stack
1439 char *uuid_string(char *buf, char *end, const u8 *addr,
1440 struct printf_spec spec, const char *fmt)
1441 {
1442 char uuid[UUID_STRING_LEN + 1];
1443 char *p = uuid;
1444 int i;
1445 const u8 *index = uuid_index;
1446 bool uc = false;
1447
1448 switch (*(++fmt)) {
1449 case 'L':
1450 uc = true; /* fall-through */
1451 case 'l':
1452 index = guid_index;
1453 break;
1454 case 'B':
1455 uc = true;
1456 break;
1457 }
1458
1459 for (i = 0; i < 16; i++) {
1460 if (uc)
1461 p = hex_byte_pack_upper(p, addr[index[i]]);
1462 else
1463 p = hex_byte_pack(p, addr[index[i]]);
1464 switch (i) {
1465 case 3:
1466 case 5:
1467 case 7:
1468 case 9:
1469 *p++ = '-';
1470 break;
1471 }
1472 }
1473
1474 *p = 0;
1475
1476 return string(buf, end, uuid, spec);
1477 }
1478
1479 int kptr_restrict __read_mostly;
1480
1481 static noinline_for_stack
1482 char *restricted_pointer(char *buf, char *end, const void *ptr,
1483 struct printf_spec spec)
1484 {
1485 switch (kptr_restrict) {
1486 case 0:
1487 /* Always print %pK values */
1488 break;
1489 case 1: {
1490 const struct cred *cred;
1491
1492 /*
1493 * kptr_restrict==1 cannot be used in IRQ context
1494 * because its test for CAP_SYSLOG would be meaningless.
1495 */
1496 if (in_irq() || in_serving_softirq() || in_nmi()) {
1497 if (spec.field_width == -1)
1498 spec.field_width = 2 * sizeof(ptr);
1499 return string(buf, end, "pK-error", spec);
1500 }
1501
1502 /*
1503 * Only print the real pointer value if the current
1504 * process has CAP_SYSLOG and is running with the
1505 * same credentials it started with. This is because
1506 * access to files is checked at open() time, but %pK
1507 * checks permission at read() time. We don't want to
1508 * leak pointer values if a binary opens a file using
1509 * %pK and then elevates privileges before reading it.
1510 */
1511 cred = current_cred();
1512 if (!has_capability_noaudit(current, CAP_SYSLOG) ||
1513 !uid_eq(cred->euid, cred->uid) ||
1514 !gid_eq(cred->egid, cred->gid))
1515 ptr = NULL;
1516 break;
1517 }
1518 case 2:
1519 default:
1520 /* Always print 0's for %pK */
1521 ptr = NULL;
1522 break;
1523 }
1524
1525 return pointer_string(buf, end, ptr, spec);
1526 }
1527
1528 static noinline_for_stack
1529 char *netdev_bits(char *buf, char *end, const void *addr,
1530 struct printf_spec spec, const char *fmt)
1531 {
1532 unsigned long long num;
1533 int size;
1534
1535 switch (fmt[1]) {
1536 case 'F':
1537 num = *(const netdev_features_t *)addr;
1538 size = sizeof(netdev_features_t);
1539 break;
1540 default:
1541 return ptr_to_id(buf, end, addr, spec);
1542 }
1543
1544 return special_hex_number(buf, end, num, size);
1545 }
1546
1547 static noinline_for_stack
1548 char *address_val(char *buf, char *end, const void *addr, const char *fmt)
1549 {
1550 unsigned long long num;
1551 int size;
1552
1553 switch (fmt[1]) {
1554 case 'd':
1555 num = *(const dma_addr_t *)addr;
1556 size = sizeof(dma_addr_t);
1557 break;
1558 case 'p':
1559 default:
1560 num = *(const phys_addr_t *)addr;
1561 size = sizeof(phys_addr_t);
1562 break;
1563 }
1564
1565 return special_hex_number(buf, end, num, size);
1566 }
1567
1568 static noinline_for_stack
1569 char *date_str(char *buf, char *end, const struct rtc_time *tm, bool r)
1570 {
1571 int year = tm->tm_year + (r ? 0 : 1900);
1572 int mon = tm->tm_mon + (r ? 0 : 1);
1573
1574 buf = number(buf, end, year, default_dec04_spec);
1575 if (buf < end)
1576 *buf = '-';
1577 buf++;
1578
1579 buf = number(buf, end, mon, default_dec02_spec);
1580 if (buf < end)
1581 *buf = '-';
1582 buf++;
1583
1584 return number(buf, end, tm->tm_mday, default_dec02_spec);
1585 }
1586
1587 static noinline_for_stack
1588 char *time_str(char *buf, char *end, const struct rtc_time *tm, bool r)
1589 {
1590 buf = number(buf, end, tm->tm_hour, default_dec02_spec);
1591 if (buf < end)
1592 *buf = ':';
1593 buf++;
1594
1595 buf = number(buf, end, tm->tm_min, default_dec02_spec);
1596 if (buf < end)
1597 *buf = ':';
1598 buf++;
1599
1600 return number(buf, end, tm->tm_sec, default_dec02_spec);
1601 }
1602
1603 static noinline_for_stack
1604 char *rtc_str(char *buf, char *end, const struct rtc_time *tm, const char *fmt)
1605 {
1606 bool have_t = true, have_d = true;
1607 bool raw = false;
1608 int count = 2;
1609
1610 switch (fmt[count]) {
1611 case 'd':
1612 have_t = false;
1613 count++;
1614 break;
1615 case 't':
1616 have_d = false;
1617 count++;
1618 break;
1619 }
1620
1621 raw = fmt[count] == 'r';
1622
1623 if (have_d)
1624 buf = date_str(buf, end, tm, raw);
1625 if (have_d && have_t) {
1626 /* Respect ISO 8601 */
1627 if (buf < end)
1628 *buf = 'T';
1629 buf++;
1630 }
1631 if (have_t)
1632 buf = time_str(buf, end, tm, raw);
1633
1634 return buf;
1635 }
1636
1637 static noinline_for_stack
1638 char *time_and_date(char *buf, char *end, void *ptr, struct printf_spec spec,
1639 const char *fmt)
1640 {
1641 switch (fmt[1]) {
1642 case 'R':
1643 return rtc_str(buf, end, (const struct rtc_time *)ptr, fmt);
1644 default:
1645 return ptr_to_id(buf, end, ptr, spec);
1646 }
1647 }
1648
1649 static noinline_for_stack
1650 char *clock(char *buf, char *end, struct clk *clk, struct printf_spec spec,
1651 const char *fmt)
1652 {
1653 if (!IS_ENABLED(CONFIG_HAVE_CLK) || !clk)
1654 return string(buf, end, NULL, spec);
1655
1656 switch (fmt[1]) {
1657 case 'n':
1658 default:
1659 #ifdef CONFIG_COMMON_CLK
1660 return string(buf, end, __clk_get_name(clk), spec);
1661 #else
1662 return ptr_to_id(buf, end, clk, spec);
1663 #endif
1664 }
1665 }
1666
1667 static
1668 char *format_flags(char *buf, char *end, unsigned long flags,
1669 const struct trace_print_flags *names)
1670 {
1671 unsigned long mask;
1672
1673 for ( ; flags && names->name; names++) {
1674 mask = names->mask;
1675 if ((flags & mask) != mask)
1676 continue;
1677
1678 buf = string(buf, end, names->name, default_str_spec);
1679
1680 flags &= ~mask;
1681 if (flags) {
1682 if (buf < end)
1683 *buf = '|';
1684 buf++;
1685 }
1686 }
1687
1688 if (flags)
1689 buf = number(buf, end, flags, default_flag_spec);
1690
1691 return buf;
1692 }
1693
1694 static noinline_for_stack
1695 char *flags_string(char *buf, char *end, void *flags_ptr, const char *fmt)
1696 {
1697 unsigned long flags;
1698 const struct trace_print_flags *names;
1699
1700 switch (fmt[1]) {
1701 case 'p':
1702 flags = *(unsigned long *)flags_ptr;
1703 /* Remove zone id */
1704 flags &= (1UL << NR_PAGEFLAGS) - 1;
1705 names = pageflag_names;
1706 break;
1707 case 'v':
1708 flags = *(unsigned long *)flags_ptr;
1709 names = vmaflag_names;
1710 break;
1711 case 'g':
1712 flags = *(gfp_t *)flags_ptr;
1713 names = gfpflag_names;
1714 break;
1715 default:
1716 WARN_ONCE(1, "Unsupported flags modifier: %c\n", fmt[1]);
1717 return buf;
1718 }
1719
1720 return format_flags(buf, end, flags, names);
1721 }
1722
1723 static const char *device_node_name_for_depth(const struct device_node *np, int depth)
1724 {
1725 for ( ; np && depth; depth--)
1726 np = np->parent;
1727
1728 return kbasename(np->full_name);
1729 }
1730
1731 static noinline_for_stack
1732 char *device_node_gen_full_name(const struct device_node *np, char *buf, char *end)
1733 {
1734 int depth;
1735 const struct device_node *parent = np->parent;
1736
1737 /* special case for root node */
1738 if (!parent)
1739 return string(buf, end, "/", default_str_spec);
1740
1741 for (depth = 0; parent->parent; depth++)
1742 parent = parent->parent;
1743
1744 for ( ; depth >= 0; depth--) {
1745 buf = string(buf, end, "/", default_str_spec);
1746 buf = string(buf, end, device_node_name_for_depth(np, depth),
1747 default_str_spec);
1748 }
1749 return buf;
1750 }
1751
1752 static noinline_for_stack
1753 char *device_node_string(char *buf, char *end, struct device_node *dn,
1754 struct printf_spec spec, const char *fmt)
1755 {
1756 char tbuf[sizeof("xxxx") + 1];
1757 const char *p;
1758 int ret;
1759 char *buf_start = buf;
1760 struct property *prop;
1761 bool has_mult, pass;
1762 static const struct printf_spec num_spec = {
1763 .flags = SMALL,
1764 .field_width = -1,
1765 .precision = -1,
1766 .base = 10,
1767 };
1768
1769 struct printf_spec str_spec = spec;
1770 str_spec.field_width = -1;
1771
1772 if (!IS_ENABLED(CONFIG_OF))
1773 return string(buf, end, "(!OF)", spec);
1774
1775 if ((unsigned long)dn < PAGE_SIZE)
1776 return string(buf, end, "(null)", spec);
1777
1778 /* simple case without anything any more format specifiers */
1779 fmt++;
1780 if (fmt[0] == '\0' || strcspn(fmt,"fnpPFcC") > 0)
1781 fmt = "f";
1782
1783 for (pass = false; strspn(fmt,"fnpPFcC"); fmt++, pass = true) {
1784 int precision;
1785 if (pass) {
1786 if (buf < end)
1787 *buf = ':';
1788 buf++;
1789 }
1790
1791 switch (*fmt) {
1792 case 'f': /* full_name */
1793 buf = device_node_gen_full_name(dn, buf, end);
1794 break;
1795 case 'n': /* name */
1796 p = kbasename(of_node_full_name(dn));
1797 precision = str_spec.precision;
1798 str_spec.precision = strchrnul(p, '@') - p;
1799 buf = string(buf, end, p, str_spec);
1800 str_spec.precision = precision;
1801 break;
1802 case 'p': /* phandle */
1803 buf = number(buf, end, (unsigned int)dn->phandle, num_spec);
1804 break;
1805 case 'P': /* path-spec */
1806 p = kbasename(of_node_full_name(dn));
1807 if (!p[1])
1808 p = "/";
1809 buf = string(buf, end, p, str_spec);
1810 break;
1811 case 'F': /* flags */
1812 tbuf[0] = of_node_check_flag(dn, OF_DYNAMIC) ? 'D' : '-';
1813 tbuf[1] = of_node_check_flag(dn, OF_DETACHED) ? 'd' : '-';
1814 tbuf[2] = of_node_check_flag(dn, OF_POPULATED) ? 'P' : '-';
1815 tbuf[3] = of_node_check_flag(dn, OF_POPULATED_BUS) ? 'B' : '-';
1816 tbuf[4] = 0;
1817 buf = string(buf, end, tbuf, str_spec);
1818 break;
1819 case 'c': /* major compatible string */
1820 ret = of_property_read_string(dn, "compatible", &p);
1821 if (!ret)
1822 buf = string(buf, end, p, str_spec);
1823 break;
1824 case 'C': /* full compatible string */
1825 has_mult = false;
1826 of_property_for_each_string(dn, "compatible", prop, p) {
1827 if (has_mult)
1828 buf = string(buf, end, ",", str_spec);
1829 buf = string(buf, end, "\"", str_spec);
1830 buf = string(buf, end, p, str_spec);
1831 buf = string(buf, end, "\"", str_spec);
1832
1833 has_mult = true;
1834 }
1835 break;
1836 default:
1837 break;
1838 }
1839 }
1840
1841 return widen_string(buf, buf - buf_start, end, spec);
1842 }
1843
1844 /*
1845 * Show a '%p' thing. A kernel extension is that the '%p' is followed
1846 * by an extra set of alphanumeric characters that are extended format
1847 * specifiers.
1848 *
1849 * Please update scripts/checkpatch.pl when adding/removing conversion
1850 * characters. (Search for "check for vsprintf extension").
1851 *
1852 * Right now we handle:
1853 *
1854 * - 'S' For symbolic direct pointers (or function descriptors) with offset
1855 * - 's' For symbolic direct pointers (or function descriptors) without offset
1856 * - 'F' Same as 'S'
1857 * - 'f' Same as 's'
1858 * - '[FfSs]R' as above with __builtin_extract_return_addr() translation
1859 * - 'B' For backtraced symbolic direct pointers with offset
1860 * - 'R' For decoded struct resource, e.g., [mem 0x0-0x1f 64bit pref]
1861 * - 'r' For raw struct resource, e.g., [mem 0x0-0x1f flags 0x201]
1862 * - 'b[l]' For a bitmap, the number of bits is determined by the field
1863 * width which must be explicitly specified either as part of the
1864 * format string '%32b[l]' or through '%*b[l]', [l] selects
1865 * range-list format instead of hex format
1866 * - 'M' For a 6-byte MAC address, it prints the address in the
1867 * usual colon-separated hex notation
1868 * - 'm' For a 6-byte MAC address, it prints the hex address without colons
1869 * - 'MF' For a 6-byte MAC FDDI address, it prints the address
1870 * with a dash-separated hex notation
1871 * - '[mM]R' For a 6-byte MAC address, Reverse order (Bluetooth)
1872 * - 'I' [46] for IPv4/IPv6 addresses printed in the usual way
1873 * IPv4 uses dot-separated decimal without leading 0's (1.2.3.4)
1874 * IPv6 uses colon separated network-order 16 bit hex with leading 0's
1875 * [S][pfs]
1876 * Generic IPv4/IPv6 address (struct sockaddr *) that falls back to
1877 * [4] or [6] and is able to print port [p], flowinfo [f], scope [s]
1878 * - 'i' [46] for 'raw' IPv4/IPv6 addresses
1879 * IPv6 omits the colons (01020304...0f)
1880 * IPv4 uses dot-separated decimal with leading 0's (010.123.045.006)
1881 * [S][pfs]
1882 * Generic IPv4/IPv6 address (struct sockaddr *) that falls back to
1883 * [4] or [6] and is able to print port [p], flowinfo [f], scope [s]
1884 * - '[Ii][4S][hnbl]' IPv4 addresses in host, network, big or little endian order
1885 * - 'I[6S]c' for IPv6 addresses printed as specified by
1886 * http://tools.ietf.org/html/rfc5952
1887 * - 'E[achnops]' For an escaped buffer, where rules are defined by combination
1888 * of the following flags (see string_escape_mem() for the
1889 * details):
1890 * a - ESCAPE_ANY
1891 * c - ESCAPE_SPECIAL
1892 * h - ESCAPE_HEX
1893 * n - ESCAPE_NULL
1894 * o - ESCAPE_OCTAL
1895 * p - ESCAPE_NP
1896 * s - ESCAPE_SPACE
1897 * By default ESCAPE_ANY_NP is used.
1898 * - 'U' For a 16 byte UUID/GUID, it prints the UUID/GUID in the form
1899 * "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx"
1900 * Options for %pU are:
1901 * b big endian lower case hex (default)
1902 * B big endian UPPER case hex
1903 * l little endian lower case hex
1904 * L little endian UPPER case hex
1905 * big endian output byte order is:
1906 * [0][1][2][3]-[4][5]-[6][7]-[8][9]-[10][11][12][13][14][15]
1907 * little endian output byte order is:
1908 * [3][2][1][0]-[5][4]-[7][6]-[8][9]-[10][11][12][13][14][15]
1909 * - 'V' For a struct va_format which contains a format string * and va_list *,
1910 * call vsnprintf(->format, *->va_list).
1911 * Implements a "recursive vsnprintf".
1912 * Do not use this feature without some mechanism to verify the
1913 * correctness of the format string and va_list arguments.
1914 * - 'K' For a kernel pointer that should be hidden from unprivileged users
1915 * - 'NF' For a netdev_features_t
1916 * - 'h[CDN]' For a variable-length buffer, it prints it as a hex string with
1917 * a certain separator (' ' by default):
1918 * C colon
1919 * D dash
1920 * N no separator
1921 * The maximum supported length is 64 bytes of the input. Consider
1922 * to use print_hex_dump() for the larger input.
1923 * - 'a[pd]' For address types [p] phys_addr_t, [d] dma_addr_t and derivatives
1924 * (default assumed to be phys_addr_t, passed by reference)
1925 * - 'd[234]' For a dentry name (optionally 2-4 last components)
1926 * - 'D[234]' Same as 'd' but for a struct file
1927 * - 'g' For block_device name (gendisk + partition number)
1928 * - 't[R][dt][r]' For time and date as represented:
1929 * R struct rtc_time
1930 * - 'C' For a clock, it prints the name (Common Clock Framework) or address
1931 * (legacy clock framework) of the clock
1932 * - 'Cn' For a clock, it prints the name (Common Clock Framework) or address
1933 * (legacy clock framework) of the clock
1934 * - 'G' For flags to be printed as a collection of symbolic strings that would
1935 * construct the specific value. Supported flags given by option:
1936 * p page flags (see struct page) given as pointer to unsigned long
1937 * g gfp flags (GFP_* and __GFP_*) given as pointer to gfp_t
1938 * v vma flags (VM_*) given as pointer to unsigned long
1939 * - 'OF[fnpPcCF]' For a device tree object
1940 * Without any optional arguments prints the full_name
1941 * f device node full_name
1942 * n device node name
1943 * p device node phandle
1944 * P device node path spec (name + @unit)
1945 * F device node flags
1946 * c major compatible string
1947 * C full compatible string
1948 * - 'x' For printing the address. Equivalent to "%lx".
1949 *
1950 * ** When making changes please also update:
1951 * Documentation/core-api/printk-formats.rst
1952 *
1953 * Note: The default behaviour (unadorned %p) is to hash the address,
1954 * rendering it useful as a unique identifier.
1955 */
1956 static noinline_for_stack
1957 char *pointer(const char *fmt, char *buf, char *end, void *ptr,
1958 struct printf_spec spec)
1959 {
1960 const int default_width = 2 * sizeof(void *);
1961
1962 if (!ptr && *fmt != 'K' && *fmt != 'x') {
1963 /*
1964 * Print (null) with the same width as a pointer so it makes
1965 * tabular output look nice.
1966 */
1967 if (spec.field_width == -1)
1968 spec.field_width = default_width;
1969 return string(buf, end, "(null)", spec);
1970 }
1971
1972 switch (*fmt) {
1973 case 'F':
1974 case 'f':
1975 case 'S':
1976 case 's':
1977 ptr = dereference_symbol_descriptor(ptr);
1978 /* Fallthrough */
1979 case 'B':
1980 return symbol_string(buf, end, ptr, spec, fmt);
1981 case 'R':
1982 case 'r':
1983 return resource_string(buf, end, ptr, spec, fmt);
1984 case 'h':
1985 return hex_string(buf, end, ptr, spec, fmt);
1986 case 'b':
1987 switch (fmt[1]) {
1988 case 'l':
1989 return bitmap_list_string(buf, end, ptr, spec, fmt);
1990 default:
1991 return bitmap_string(buf, end, ptr, spec, fmt);
1992 }
1993 case 'M': /* Colon separated: 00:01:02:03:04:05 */
1994 case 'm': /* Contiguous: 000102030405 */
1995 /* [mM]F (FDDI) */
1996 /* [mM]R (Reverse order; Bluetooth) */
1997 return mac_address_string(buf, end, ptr, spec, fmt);
1998 case 'I': /* Formatted IP supported
1999 * 4: 1.2.3.4
2000 * 6: 0001:0203:...:0708
2001 * 6c: 1::708 or 1::1.2.3.4
2002 */
2003 case 'i': /* Contiguous:
2004 * 4: 001.002.003.004
2005 * 6: 000102...0f
2006 */
2007 switch (fmt[1]) {
2008 case '6':
2009 return ip6_addr_string(buf, end, ptr, spec, fmt);
2010 case '4':
2011 return ip4_addr_string(buf, end, ptr, spec, fmt);
2012 case 'S': {
2013 const union {
2014 struct sockaddr raw;
2015 struct sockaddr_in v4;
2016 struct sockaddr_in6 v6;
2017 } *sa = ptr;
2018
2019 switch (sa->raw.sa_family) {
2020 case AF_INET:
2021 return ip4_addr_string_sa(buf, end, &sa->v4, spec, fmt);
2022 case AF_INET6:
2023 return ip6_addr_string_sa(buf, end, &sa->v6, spec, fmt);
2024 default:
2025 return string(buf, end, "(invalid address)", spec);
2026 }}
2027 }
2028 break;
2029 case 'E':
2030 return escaped_string(buf, end, ptr, spec, fmt);
2031 case 'U':
2032 return uuid_string(buf, end, ptr, spec, fmt);
2033 case 'V':
2034 {
2035 va_list va;
2036
2037 va_copy(va, *((struct va_format *)ptr)->va);
2038 buf += vsnprintf(buf, end > buf ? end - buf : 0,
2039 ((struct va_format *)ptr)->fmt, va);
2040 va_end(va);
2041 return buf;
2042 }
2043 case 'K':
2044 if (!kptr_restrict)
2045 break;
2046 return restricted_pointer(buf, end, ptr, spec);
2047 case 'N':
2048 return netdev_bits(buf, end, ptr, spec, fmt);
2049 case 'a':
2050 return address_val(buf, end, ptr, fmt);
2051 case 'd':
2052 return dentry_name(buf, end, ptr, spec, fmt);
2053 case 't':
2054 return time_and_date(buf, end, ptr, spec, fmt);
2055 case 'C':
2056 return clock(buf, end, ptr, spec, fmt);
2057 case 'D':
2058 return dentry_name(buf, end,
2059 ((const struct file *)ptr)->f_path.dentry,
2060 spec, fmt);
2061 #ifdef CONFIG_BLOCK
2062 case 'g':
2063 return bdev_name(buf, end, ptr, spec, fmt);
2064 #endif
2065
2066 case 'G':
2067 return flags_string(buf, end, ptr, fmt);
2068 case 'O':
2069 switch (fmt[1]) {
2070 case 'F':
2071 return device_node_string(buf, end, ptr, spec, fmt + 1);
2072 }
2073 break;
2074 case 'x':
2075 return pointer_string(buf, end, ptr, spec);
2076 }
2077
2078 /* default is to _not_ leak addresses, hash before printing */
2079 return ptr_to_id(buf, end, ptr, spec);
2080 }
2081
2082 /*
2083 * Helper function to decode printf style format.
2084 * Each call decode a token from the format and return the
2085 * number of characters read (or likely the delta where it wants
2086 * to go on the next call).
2087 * The decoded token is returned through the parameters
2088 *
2089 * 'h', 'l', or 'L' for integer fields
2090 * 'z' support added 23/7/1999 S.H.
2091 * 'z' changed to 'Z' --davidm 1/25/99
2092 * 'Z' changed to 'z' --adobriyan 2017-01-25
2093 * 't' added for ptrdiff_t
2094 *
2095 * @fmt: the format string
2096 * @type of the token returned
2097 * @flags: various flags such as +, -, # tokens..
2098 * @field_width: overwritten width
2099 * @base: base of the number (octal, hex, ...)
2100 * @precision: precision of a number
2101 * @qualifier: qualifier of a number (long, size_t, ...)
2102 */
2103 static noinline_for_stack
2104 int format_decode(const char *fmt, struct printf_spec *spec)
2105 {
2106 const char *start = fmt;
2107 char qualifier;
2108
2109 /* we finished early by reading the field width */
2110 if (spec->type == FORMAT_TYPE_WIDTH) {
2111 if (spec->field_width < 0) {
2112 spec->field_width = -spec->field_width;
2113 spec->flags |= LEFT;
2114 }
2115 spec->type = FORMAT_TYPE_NONE;
2116 goto precision;
2117 }
2118
2119 /* we finished early by reading the precision */
2120 if (spec->type == FORMAT_TYPE_PRECISION) {
2121 if (spec->precision < 0)
2122 spec->precision = 0;
2123
2124 spec->type = FORMAT_TYPE_NONE;
2125 goto qualifier;
2126 }
2127
2128 /* By default */
2129 spec->type = FORMAT_TYPE_NONE;
2130
2131 for (; *fmt ; ++fmt) {
2132 if (*fmt == '%')
2133 break;
2134 }
2135
2136 /* Return the current non-format string */
2137 if (fmt != start || !*fmt)
2138 return fmt - start;
2139
2140 /* Process flags */
2141 spec->flags = 0;
2142
2143 while (1) { /* this also skips first '%' */
2144 bool found = true;
2145
2146 ++fmt;
2147
2148 switch (*fmt) {
2149 case '-': spec->flags |= LEFT; break;
2150 case '+': spec->flags |= PLUS; break;
2151 case ' ': spec->flags |= SPACE; break;
2152 case '#': spec->flags |= SPECIAL; break;
2153 case '0': spec->flags |= ZEROPAD; break;
2154 default: found = false;
2155 }
2156
2157 if (!found)
2158 break;
2159 }
2160
2161 /* get field width */
2162 spec->field_width = -1;
2163
2164 if (isdigit(*fmt))
2165 spec->field_width = skip_atoi(&fmt);
2166 else if (*fmt == '*') {
2167 /* it's the next argument */
2168 spec->type = FORMAT_TYPE_WIDTH;
2169 return ++fmt - start;
2170 }
2171
2172 precision:
2173 /* get the precision */
2174 spec->precision = -1;
2175 if (*fmt == '.') {
2176 ++fmt;
2177 if (isdigit(*fmt)) {
2178 spec->precision = skip_atoi(&fmt);
2179 if (spec->precision < 0)
2180 spec->precision = 0;
2181 } else if (*fmt == '*') {
2182 /* it's the next argument */
2183 spec->type = FORMAT_TYPE_PRECISION;
2184 return ++fmt - start;
2185 }
2186 }
2187
2188 qualifier:
2189 /* get the conversion qualifier */
2190 qualifier = 0;
2191 if (*fmt == 'h' || _tolower(*fmt) == 'l' ||
2192 *fmt == 'z' || *fmt == 't') {
2193 qualifier = *fmt++;
2194 if (unlikely(qualifier == *fmt)) {
2195 if (qualifier == 'l') {
2196 qualifier = 'L';
2197 ++fmt;
2198 } else if (qualifier == 'h') {
2199 qualifier = 'H';
2200 ++fmt;
2201 }
2202 }
2203 }
2204
2205 /* default base */
2206 spec->base = 10;
2207 switch (*fmt) {
2208 case 'c':
2209 spec->type = FORMAT_TYPE_CHAR;
2210 return ++fmt - start;
2211
2212 case 's':
2213 spec->type = FORMAT_TYPE_STR;
2214 return ++fmt - start;
2215
2216 case 'p':
2217 spec->type = FORMAT_TYPE_PTR;
2218 return ++fmt - start;
2219
2220 case '%':
2221 spec->type = FORMAT_TYPE_PERCENT_CHAR;
2222 return ++fmt - start;
2223
2224 /* integer number formats - set up the flags and "break" */
2225 case 'o':
2226 spec->base = 8;
2227 break;
2228
2229 case 'x':
2230 spec->flags |= SMALL;
2231 /* fall through */
2232
2233 case 'X':
2234 spec->base = 16;
2235 break;
2236
2237 case 'd':
2238 case 'i':
2239 spec->flags |= SIGN;
2240 case 'u':
2241 break;
2242
2243 case 'n':
2244 /*
2245 * Since %n poses a greater security risk than
2246 * utility, treat it as any other invalid or
2247 * unsupported format specifier.
2248 */
2249 /* Fall-through */
2250
2251 default:
2252 WARN_ONCE(1, "Please remove unsupported %%%c in format string\n", *fmt);
2253 spec->type = FORMAT_TYPE_INVALID;
2254 return fmt - start;
2255 }
2256
2257 if (qualifier == 'L')
2258 spec->type = FORMAT_TYPE_LONG_LONG;
2259 else if (qualifier == 'l') {
2260 BUILD_BUG_ON(FORMAT_TYPE_ULONG + SIGN != FORMAT_TYPE_LONG);
2261 spec->type = FORMAT_TYPE_ULONG + (spec->flags & SIGN);
2262 } else if (qualifier == 'z') {
2263 spec->type = FORMAT_TYPE_SIZE_T;
2264 } else if (qualifier == 't') {
2265 spec->type = FORMAT_TYPE_PTRDIFF;
2266 } else if (qualifier == 'H') {
2267 BUILD_BUG_ON(FORMAT_TYPE_UBYTE + SIGN != FORMAT_TYPE_BYTE);
2268 spec->type = FORMAT_TYPE_UBYTE + (spec->flags & SIGN);
2269 } else if (qualifier == 'h') {
2270 BUILD_BUG_ON(FORMAT_TYPE_USHORT + SIGN != FORMAT_TYPE_SHORT);
2271 spec->type = FORMAT_TYPE_USHORT + (spec->flags & SIGN);
2272 } else {
2273 BUILD_BUG_ON(FORMAT_TYPE_UINT + SIGN != FORMAT_TYPE_INT);
2274 spec->type = FORMAT_TYPE_UINT + (spec->flags & SIGN);
2275 }
2276
2277 return ++fmt - start;
2278 }
2279
2280 static void
2281 set_field_width(struct printf_spec *spec, int width)
2282 {
2283 spec->field_width = width;
2284 if (WARN_ONCE(spec->field_width != width, "field width %d too large", width)) {
2285 spec->field_width = clamp(width, -FIELD_WIDTH_MAX, FIELD_WIDTH_MAX);
2286 }
2287 }
2288
2289 static void
2290 set_precision(struct printf_spec *spec, int prec)
2291 {
2292 spec->precision = prec;
2293 if (WARN_ONCE(spec->precision != prec, "precision %d too large", prec)) {
2294 spec->precision = clamp(prec, 0, PRECISION_MAX);
2295 }
2296 }
2297
2298 /**
2299 * vsnprintf - Format a string and place it in a buffer
2300 * @buf: The buffer to place the result into
2301 * @size: The size of the buffer, including the trailing null space
2302 * @fmt: The format string to use
2303 * @args: Arguments for the format string
2304 *
2305 * This function generally follows C99 vsnprintf, but has some
2306 * extensions and a few limitations:
2307 *
2308 * - ``%n`` is unsupported
2309 * - ``%p*`` is handled by pointer()
2310 *
2311 * See pointer() or Documentation/core-api/printk-formats.rst for more
2312 * extensive description.
2313 *
2314 * **Please update the documentation in both places when making changes**
2315 *
2316 * The return value is the number of characters which would
2317 * be generated for the given input, excluding the trailing
2318 * '\0', as per ISO C99. If you want to have the exact
2319 * number of characters written into @buf as return value
2320 * (not including the trailing '\0'), use vscnprintf(). If the
2321 * return is greater than or equal to @size, the resulting
2322 * string is truncated.
2323 *
2324 * If you're not already dealing with a va_list consider using snprintf().
2325 */
2326 int vsnprintf(char *buf, size_t size, const char *fmt, va_list args)
2327 {
2328 unsigned long long num;
2329 char *str, *end;
2330 struct printf_spec spec = {0};
2331
2332 /* Reject out-of-range values early. Large positive sizes are
2333 used for unknown buffer sizes. */
2334 if (WARN_ON_ONCE(size > INT_MAX))
2335 return 0;
2336
2337 str = buf;
2338 end = buf + size;
2339
2340 /* Make sure end is always >= buf */
2341 if (end < buf) {
2342 end = ((void *)-1);
2343 size = end - buf;
2344 }
2345
2346 while (*fmt) {
2347 const char *old_fmt = fmt;
2348 int read = format_decode(fmt, &spec);
2349
2350 fmt += read;
2351
2352 switch (spec.type) {
2353 case FORMAT_TYPE_NONE: {
2354 int copy = read;
2355 if (str < end) {
2356 if (copy > end - str)
2357 copy = end - str;
2358 memcpy(str, old_fmt, copy);
2359 }
2360 str += read;
2361 break;
2362 }
2363
2364 case FORMAT_TYPE_WIDTH:
2365 set_field_width(&spec, va_arg(args, int));
2366 break;
2367
2368 case FORMAT_TYPE_PRECISION:
2369 set_precision(&spec, va_arg(args, int));
2370 break;
2371
2372 case FORMAT_TYPE_CHAR: {
2373 char c;
2374
2375 if (!(spec.flags & LEFT)) {
2376 while (--spec.field_width > 0) {
2377 if (str < end)
2378 *str = ' ';
2379 ++str;
2380
2381 }
2382 }
2383 c = (unsigned char) va_arg(args, int);
2384 if (str < end)
2385 *str = c;
2386 ++str;
2387 while (--spec.field_width > 0) {
2388 if (str < end)
2389 *str = ' ';
2390 ++str;
2391 }
2392 break;
2393 }
2394
2395 case FORMAT_TYPE_STR:
2396 str = string(str, end, va_arg(args, char *), spec);
2397 break;
2398
2399 case FORMAT_TYPE_PTR:
2400 str = pointer(fmt, str, end, va_arg(args, void *),
2401 spec);
2402 while (isalnum(*fmt))
2403 fmt++;
2404 break;
2405
2406 case FORMAT_TYPE_PERCENT_CHAR:
2407 if (str < end)
2408 *str = '%';
2409 ++str;
2410 break;
2411
2412 case FORMAT_TYPE_INVALID:
2413 /*
2414 * Presumably the arguments passed gcc's type
2415 * checking, but there is no safe or sane way
2416 * for us to continue parsing the format and
2417 * fetching from the va_list; the remaining
2418 * specifiers and arguments would be out of
2419 * sync.
2420 */
2421 goto out;
2422
2423 default:
2424 switch (spec.type) {
2425 case FORMAT_TYPE_LONG_LONG:
2426 num = va_arg(args, long long);
2427 break;
2428 case FORMAT_TYPE_ULONG:
2429 num = va_arg(args, unsigned long);
2430 break;
2431 case FORMAT_TYPE_LONG:
2432 num = va_arg(args, long);
2433 break;
2434 case FORMAT_TYPE_SIZE_T:
2435 if (spec.flags & SIGN)
2436 num = va_arg(args, ssize_t);
2437 else
2438 num = va_arg(args, size_t);
2439 break;
2440 case FORMAT_TYPE_PTRDIFF:
2441 num = va_arg(args, ptrdiff_t);
2442 break;
2443 case FORMAT_TYPE_UBYTE:
2444 num = (unsigned char) va_arg(args, int);
2445 break;
2446 case FORMAT_TYPE_BYTE:
2447 num = (signed char) va_arg(args, int);
2448 break;
2449 case FORMAT_TYPE_USHORT:
2450 num = (unsigned short) va_arg(args, int);
2451 break;
2452 case FORMAT_TYPE_SHORT:
2453 num = (short) va_arg(args, int);
2454 break;
2455 case FORMAT_TYPE_INT:
2456 num = (int) va_arg(args, int);
2457 break;
2458 default:
2459 num = va_arg(args, unsigned int);
2460 }
2461
2462 str = number(str, end, num, spec);
2463 }
2464 }
2465
2466 out:
2467 if (size > 0) {
2468 if (str < end)
2469 *str = '\0';
2470 else
2471 end[-1] = '\0';
2472 }
2473
2474 /* the trailing null byte doesn't count towards the total */
2475 return str-buf;
2476
2477 }
2478 EXPORT_SYMBOL(vsnprintf);
2479
2480 /**
2481 * vscnprintf - Format a string and place it in a buffer
2482 * @buf: The buffer to place the result into
2483 * @size: The size of the buffer, including the trailing null space
2484 * @fmt: The format string to use
2485 * @args: Arguments for the format string
2486 *
2487 * The return value is the number of characters which have been written into
2488 * the @buf not including the trailing '\0'. If @size is == 0 the function
2489 * returns 0.
2490 *
2491 * If you're not already dealing with a va_list consider using scnprintf().
2492 *
2493 * See the vsnprintf() documentation for format string extensions over C99.
2494 */
2495 int vscnprintf(char *buf, size_t size, const char *fmt, va_list args)
2496 {
2497 int i;
2498
2499 i = vsnprintf(buf, size, fmt, args);
2500
2501 if (likely(i < size))
2502 return i;
2503 if (size != 0)
2504 return size - 1;
2505 return 0;
2506 }
2507 EXPORT_SYMBOL(vscnprintf);
2508
2509 /**
2510 * snprintf - Format a string and place it in a buffer
2511 * @buf: The buffer to place the result into
2512 * @size: The size of the buffer, including the trailing null space
2513 * @fmt: The format string to use
2514 * @...: Arguments for the format string
2515 *
2516 * The return value is the number of characters which would be
2517 * generated for the given input, excluding the trailing null,
2518 * as per ISO C99. If the return is greater than or equal to
2519 * @size, the resulting string is truncated.
2520 *
2521 * See the vsnprintf() documentation for format string extensions over C99.
2522 */
2523 int snprintf(char *buf, size_t size, const char *fmt, ...)
2524 {
2525 va_list args;
2526 int i;
2527
2528 va_start(args, fmt);
2529 i = vsnprintf(buf, size, fmt, args);
2530 va_end(args);
2531
2532 return i;
2533 }
2534 EXPORT_SYMBOL(snprintf);
2535
2536 /**
2537 * scnprintf - Format a string and place it in a buffer
2538 * @buf: The buffer to place the result into
2539 * @size: The size of the buffer, including the trailing null space
2540 * @fmt: The format string to use
2541 * @...: Arguments for the format string
2542 *
2543 * The return value is the number of characters written into @buf not including
2544 * the trailing '\0'. If @size is == 0 the function returns 0.
2545 */
2546
2547 int scnprintf(char *buf, size_t size, const char *fmt, ...)
2548 {
2549 va_list args;
2550 int i;
2551
2552 va_start(args, fmt);
2553 i = vscnprintf(buf, size, fmt, args);
2554 va_end(args);
2555
2556 return i;
2557 }
2558 EXPORT_SYMBOL(scnprintf);
2559
2560 /**
2561 * vsprintf - Format a string and place it in a buffer
2562 * @buf: The buffer to place the result into
2563 * @fmt: The format string to use
2564 * @args: Arguments for the format string
2565 *
2566 * The function returns the number of characters written
2567 * into @buf. Use vsnprintf() or vscnprintf() in order to avoid
2568 * buffer overflows.
2569 *
2570 * If you're not already dealing with a va_list consider using sprintf().
2571 *
2572 * See the vsnprintf() documentation for format string extensions over C99.
2573 */
2574 int vsprintf(char *buf, const char *fmt, va_list args)
2575 {
2576 return vsnprintf(buf, INT_MAX, fmt, args);
2577 }
2578 EXPORT_SYMBOL(vsprintf);
2579
2580 /**
2581 * sprintf - Format a string and place it in a buffer
2582 * @buf: The buffer to place the result into
2583 * @fmt: The format string to use
2584 * @...: Arguments for the format string
2585 *
2586 * The function returns the number of characters written
2587 * into @buf. Use snprintf() or scnprintf() in order to avoid
2588 * buffer overflows.
2589 *
2590 * See the vsnprintf() documentation for format string extensions over C99.
2591 */
2592 int sprintf(char *buf, const char *fmt, ...)
2593 {
2594 va_list args;
2595 int i;
2596
2597 va_start(args, fmt);
2598 i = vsnprintf(buf, INT_MAX, fmt, args);
2599 va_end(args);
2600
2601 return i;
2602 }
2603 EXPORT_SYMBOL(sprintf);
2604
2605 #ifdef CONFIG_BINARY_PRINTF
2606 /*
2607 * bprintf service:
2608 * vbin_printf() - VA arguments to binary data
2609 * bstr_printf() - Binary data to text string
2610 */
2611
2612 /**
2613 * vbin_printf - Parse a format string and place args' binary value in a buffer
2614 * @bin_buf: The buffer to place args' binary value
2615 * @size: The size of the buffer(by words(32bits), not characters)
2616 * @fmt: The format string to use
2617 * @args: Arguments for the format string
2618 *
2619 * The format follows C99 vsnprintf, except %n is ignored, and its argument
2620 * is skipped.
2621 *
2622 * The return value is the number of words(32bits) which would be generated for
2623 * the given input.
2624 *
2625 * NOTE:
2626 * If the return value is greater than @size, the resulting bin_buf is NOT
2627 * valid for bstr_printf().
2628 */
2629 int vbin_printf(u32 *bin_buf, size_t size, const char *fmt, va_list args)
2630 {
2631 struct printf_spec spec = {0};
2632 char *str, *end;
2633 int width;
2634
2635 str = (char *)bin_buf;
2636 end = (char *)(bin_buf + size);
2637
2638 #define save_arg(type) \
2639 ({ \
2640 unsigned long long value; \
2641 if (sizeof(type) == 8) { \
2642 unsigned long long val8; \
2643 str = PTR_ALIGN(str, sizeof(u32)); \
2644 val8 = va_arg(args, unsigned long long); \
2645 if (str + sizeof(type) <= end) { \
2646 *(u32 *)str = *(u32 *)&val8; \
2647 *(u32 *)(str + 4) = *((u32 *)&val8 + 1); \
2648 } \
2649 value = val8; \
2650 } else { \
2651 unsigned int val4; \
2652 str = PTR_ALIGN(str, sizeof(type)); \
2653 val4 = va_arg(args, int); \
2654 if (str + sizeof(type) <= end) \
2655 *(typeof(type) *)str = (type)(long)val4; \
2656 value = (unsigned long long)val4; \
2657 } \
2658 str += sizeof(type); \
2659 value; \
2660 })
2661
2662 while (*fmt) {
2663 int read = format_decode(fmt, &spec);
2664
2665 fmt += read;
2666
2667 switch (spec.type) {
2668 case FORMAT_TYPE_NONE:
2669 case FORMAT_TYPE_PERCENT_CHAR:
2670 break;
2671 case FORMAT_TYPE_INVALID:
2672 goto out;
2673
2674 case FORMAT_TYPE_WIDTH:
2675 case FORMAT_TYPE_PRECISION:
2676 width = (int)save_arg(int);
2677 /* Pointers may require the width */
2678 if (*fmt == 'p')
2679 set_field_width(&spec, width);
2680 break;
2681
2682 case FORMAT_TYPE_CHAR:
2683 save_arg(char);
2684 break;
2685
2686 case FORMAT_TYPE_STR: {
2687 const char *save_str = va_arg(args, char *);
2688 size_t len;
2689
2690 if ((unsigned long)save_str > (unsigned long)-PAGE_SIZE
2691 || (unsigned long)save_str < PAGE_SIZE)
2692 save_str = "(null)";
2693 len = strlen(save_str) + 1;
2694 if (str + len < end)
2695 memcpy(str, save_str, len);
2696 str += len;
2697 break;
2698 }
2699
2700 case FORMAT_TYPE_PTR:
2701 /* Dereferenced pointers must be done now */
2702 switch (*fmt) {
2703 /* Dereference of functions is still OK */
2704 case 'S':
2705 case 's':
2706 case 'F':
2707 case 'f':
2708 case 'x':
2709 case 'K':
2710 save_arg(void *);
2711 break;
2712 default:
2713 if (!isalnum(*fmt)) {
2714 save_arg(void *);
2715 break;
2716 }
2717 str = pointer(fmt, str, end, va_arg(args, void *),
2718 spec);
2719 if (str + 1 < end)
2720 *str++ = '\0';
2721 else
2722 end[-1] = '\0'; /* Must be nul terminated */
2723 }
2724 /* skip all alphanumeric pointer suffixes */
2725 while (isalnum(*fmt))
2726 fmt++;
2727 break;
2728
2729 default:
2730 switch (spec.type) {
2731
2732 case FORMAT_TYPE_LONG_LONG:
2733 save_arg(long long);
2734 break;
2735 case FORMAT_TYPE_ULONG:
2736 case FORMAT_TYPE_LONG:
2737 save_arg(unsigned long);
2738 break;
2739 case FORMAT_TYPE_SIZE_T:
2740 save_arg(size_t);
2741 break;
2742 case FORMAT_TYPE_PTRDIFF:
2743 save_arg(ptrdiff_t);
2744 break;
2745 case FORMAT_TYPE_UBYTE:
2746 case FORMAT_TYPE_BYTE:
2747 save_arg(char);
2748 break;
2749 case FORMAT_TYPE_USHORT:
2750 case FORMAT_TYPE_SHORT:
2751 save_arg(short);
2752 break;
2753 default:
2754 save_arg(int);
2755 }
2756 }
2757 }
2758
2759 out:
2760 return (u32 *)(PTR_ALIGN(str, sizeof(u32))) - bin_buf;
2761 #undef save_arg
2762 }
2763 EXPORT_SYMBOL_GPL(vbin_printf);
2764
2765 /**
2766 * bstr_printf - Format a string from binary arguments and place it in a buffer
2767 * @buf: The buffer to place the result into
2768 * @size: The size of the buffer, including the trailing null space
2769 * @fmt: The format string to use
2770 * @bin_buf: Binary arguments for the format string
2771 *
2772 * This function like C99 vsnprintf, but the difference is that vsnprintf gets
2773 * arguments from stack, and bstr_printf gets arguments from @bin_buf which is
2774 * a binary buffer that generated by vbin_printf.
2775 *
2776 * The format follows C99 vsnprintf, but has some extensions:
2777 * see vsnprintf comment for details.
2778 *
2779 * The return value is the number of characters which would
2780 * be generated for the given input, excluding the trailing
2781 * '\0', as per ISO C99. If you want to have the exact
2782 * number of characters written into @buf as return value
2783 * (not including the trailing '\0'), use vscnprintf(). If the
2784 * return is greater than or equal to @size, the resulting
2785 * string is truncated.
2786 */
2787 int bstr_printf(char *buf, size_t size, const char *fmt, const u32 *bin_buf)
2788 {
2789 struct printf_spec spec = {0};
2790 char *str, *end;
2791 const char *args = (const char *)bin_buf;
2792
2793 if (WARN_ON_ONCE(size > INT_MAX))
2794 return 0;
2795
2796 str = buf;
2797 end = buf + size;
2798
2799 #define get_arg(type) \
2800 ({ \
2801 typeof(type) value; \
2802 if (sizeof(type) == 8) { \
2803 args = PTR_ALIGN(args, sizeof(u32)); \
2804 *(u32 *)&value = *(u32 *)args; \
2805 *((u32 *)&value + 1) = *(u32 *)(args + 4); \
2806 } else { \
2807 args = PTR_ALIGN(args, sizeof(type)); \
2808 value = *(typeof(type) *)args; \
2809 } \
2810 args += sizeof(type); \
2811 value; \
2812 })
2813
2814 /* Make sure end is always >= buf */
2815 if (end < buf) {
2816 end = ((void *)-1);
2817 size = end - buf;
2818 }
2819
2820 while (*fmt) {
2821 const char *old_fmt = fmt;
2822 int read = format_decode(fmt, &spec);
2823
2824 fmt += read;
2825
2826 switch (spec.type) {
2827 case FORMAT_TYPE_NONE: {
2828 int copy = read;
2829 if (str < end) {
2830 if (copy > end - str)
2831 copy = end - str;
2832 memcpy(str, old_fmt, copy);
2833 }
2834 str += read;
2835 break;
2836 }
2837
2838 case FORMAT_TYPE_WIDTH:
2839 set_field_width(&spec, get_arg(int));
2840 break;
2841
2842 case FORMAT_TYPE_PRECISION:
2843 set_precision(&spec, get_arg(int));
2844 break;
2845
2846 case FORMAT_TYPE_CHAR: {
2847 char c;
2848
2849 if (!(spec.flags & LEFT)) {
2850 while (--spec.field_width > 0) {
2851 if (str < end)
2852 *str = ' ';
2853 ++str;
2854 }
2855 }
2856 c = (unsigned char) get_arg(char);
2857 if (str < end)
2858 *str = c;
2859 ++str;
2860 while (--spec.field_width > 0) {
2861 if (str < end)
2862 *str = ' ';
2863 ++str;
2864 }
2865 break;
2866 }
2867
2868 case FORMAT_TYPE_STR: {
2869 const char *str_arg = args;
2870 args += strlen(str_arg) + 1;
2871 str = string(str, end, (char *)str_arg, spec);
2872 break;
2873 }
2874
2875 case FORMAT_TYPE_PTR: {
2876 bool process = false;
2877 int copy, len;
2878 /* Non function dereferences were already done */
2879 switch (*fmt) {
2880 case 'S':
2881 case 's':
2882 case 'F':
2883 case 'f':
2884 case 'x':
2885 case 'K':
2886 process = true;
2887 break;
2888 default:
2889 if (!isalnum(*fmt)) {
2890 process = true;
2891 break;
2892 }
2893 /* Pointer dereference was already processed */
2894 if (str < end) {
2895 len = copy = strlen(args);
2896 if (copy > end - str)
2897 copy = end - str;
2898 memcpy(str, args, copy);
2899 str += len;
2900 args += len + 1;
2901 }
2902 }
2903 if (process)
2904 str = pointer(fmt, str, end, get_arg(void *), spec);
2905
2906 while (isalnum(*fmt))
2907 fmt++;
2908 break;
2909 }
2910
2911 case FORMAT_TYPE_PERCENT_CHAR:
2912 if (str < end)
2913 *str = '%';
2914 ++str;
2915 break;
2916
2917 case FORMAT_TYPE_INVALID:
2918 goto out;
2919
2920 default: {
2921 unsigned long long num;
2922
2923 switch (spec.type) {
2924
2925 case FORMAT_TYPE_LONG_LONG:
2926 num = get_arg(long long);
2927 break;
2928 case FORMAT_TYPE_ULONG:
2929 case FORMAT_TYPE_LONG:
2930 num = get_arg(unsigned long);
2931 break;
2932 case FORMAT_TYPE_SIZE_T:
2933 num = get_arg(size_t);
2934 break;
2935 case FORMAT_TYPE_PTRDIFF:
2936 num = get_arg(ptrdiff_t);
2937 break;
2938 case FORMAT_TYPE_UBYTE:
2939 num = get_arg(unsigned char);
2940 break;
2941 case FORMAT_TYPE_BYTE:
2942 num = get_arg(signed char);
2943 break;
2944 case FORMAT_TYPE_USHORT:
2945 num = get_arg(unsigned short);
2946 break;
2947 case FORMAT_TYPE_SHORT:
2948 num = get_arg(short);
2949 break;
2950 case FORMAT_TYPE_UINT:
2951 num = get_arg(unsigned int);
2952 break;
2953 default:
2954 num = get_arg(int);
2955 }
2956
2957 str = number(str, end, num, spec);
2958 } /* default: */
2959 } /* switch(spec.type) */
2960 } /* while(*fmt) */
2961
2962 out:
2963 if (size > 0) {
2964 if (str < end)
2965 *str = '\0';
2966 else
2967 end[-1] = '\0';
2968 }
2969
2970 #undef get_arg
2971
2972 /* the trailing null byte doesn't count towards the total */
2973 return str - buf;
2974 }
2975 EXPORT_SYMBOL_GPL(bstr_printf);
2976
2977 /**
2978 * bprintf - Parse a format string and place args' binary value in a buffer
2979 * @bin_buf: The buffer to place args' binary value
2980 * @size: The size of the buffer(by words(32bits), not characters)
2981 * @fmt: The format string to use
2982 * @...: Arguments for the format string
2983 *
2984 * The function returns the number of words(u32) written
2985 * into @bin_buf.
2986 */
2987 int bprintf(u32 *bin_buf, size_t size, const char *fmt, ...)
2988 {
2989 va_list args;
2990 int ret;
2991
2992 va_start(args, fmt);
2993 ret = vbin_printf(bin_buf, size, fmt, args);
2994 va_end(args);
2995
2996 return ret;
2997 }
2998 EXPORT_SYMBOL_GPL(bprintf);
2999
3000 #endif /* CONFIG_BINARY_PRINTF */
3001
3002 /**
3003 * vsscanf - Unformat a buffer into a list of arguments
3004 * @buf: input buffer
3005 * @fmt: format of buffer
3006 * @args: arguments
3007 */
3008 int vsscanf(const char *buf, const char *fmt, va_list args)
3009 {
3010 const char *str = buf;
3011 char *next;
3012 char digit;
3013 int num = 0;
3014 u8 qualifier;
3015 unsigned int base;
3016 union {
3017 long long s;
3018 unsigned long long u;
3019 } val;
3020 s16 field_width;
3021 bool is_sign;
3022
3023 while (*fmt) {
3024 /* skip any white space in format */
3025 /* white space in format matchs any amount of
3026 * white space, including none, in the input.
3027 */
3028 if (isspace(*fmt)) {
3029 fmt = skip_spaces(++fmt);
3030 str = skip_spaces(str);
3031 }
3032
3033 /* anything that is not a conversion must match exactly */
3034 if (*fmt != '%' && *fmt) {
3035 if (*fmt++ != *str++)
3036 break;
3037 continue;
3038 }
3039
3040 if (!*fmt)
3041 break;
3042 ++fmt;
3043
3044 /* skip this conversion.
3045 * advance both strings to next white space
3046 */
3047 if (*fmt == '*') {
3048 if (!*str)
3049 break;
3050 while (!isspace(*fmt) && *fmt != '%' && *fmt) {
3051 /* '%*[' not yet supported, invalid format */
3052 if (*fmt == '[')
3053 return num;
3054 fmt++;
3055 }
3056 while (!isspace(*str) && *str)
3057 str++;
3058 continue;
3059 }
3060
3061 /* get field width */
3062 field_width = -1;
3063 if (isdigit(*fmt)) {
3064 field_width = skip_atoi(&fmt);
3065 if (field_width <= 0)
3066 break;
3067 }
3068
3069 /* get conversion qualifier */
3070 qualifier = -1;
3071 if (*fmt == 'h' || _tolower(*fmt) == 'l' ||
3072 *fmt == 'z') {
3073 qualifier = *fmt++;
3074 if (unlikely(qualifier == *fmt)) {
3075 if (qualifier == 'h') {
3076 qualifier = 'H';
3077 fmt++;
3078 } else if (qualifier == 'l') {
3079 qualifier = 'L';
3080 fmt++;
3081 }
3082 }
3083 }
3084
3085 if (!*fmt)
3086 break;
3087
3088 if (*fmt == 'n') {
3089 /* return number of characters read so far */
3090 *va_arg(args, int *) = str - buf;
3091 ++fmt;
3092 continue;
3093 }
3094
3095 if (!*str)
3096 break;
3097
3098 base = 10;
3099 is_sign = false;
3100
3101 switch (*fmt++) {
3102 case 'c':
3103 {
3104 char *s = (char *)va_arg(args, char*);
3105 if (field_width == -1)
3106 field_width = 1;
3107 do {
3108 *s++ = *str++;
3109 } while (--field_width > 0 && *str);
3110 num++;
3111 }
3112 continue;
3113 case 's':
3114 {
3115 char *s = (char *)va_arg(args, char *);
3116 if (field_width == -1)
3117 field_width = SHRT_MAX;
3118 /* first, skip leading white space in buffer */
3119 str = skip_spaces(str);
3120
3121 /* now copy until next white space */
3122 while (*str && !isspace(*str) && field_width--)
3123 *s++ = *str++;
3124 *s = '\0';
3125 num++;
3126 }
3127 continue;
3128 /*
3129 * Warning: This implementation of the '[' conversion specifier
3130 * deviates from its glibc counterpart in the following ways:
3131 * (1) It does NOT support ranges i.e. '-' is NOT a special
3132 * character
3133 * (2) It cannot match the closing bracket ']' itself
3134 * (3) A field width is required
3135 * (4) '%*[' (discard matching input) is currently not supported
3136 *
3137 * Example usage:
3138 * ret = sscanf("00:0a:95","%2[^:]:%2[^:]:%2[^:]",
3139 * buf1, buf2, buf3);
3140 * if (ret < 3)
3141 * // etc..
3142 */
3143 case '[':
3144 {
3145 char *s = (char *)va_arg(args, char *);
3146 DECLARE_BITMAP(set, 256) = {0};
3147 unsigned int len = 0;
3148 bool negate = (*fmt == '^');
3149
3150 /* field width is required */
3151 if (field_width == -1)
3152 return num;
3153
3154 if (negate)
3155 ++fmt;
3156
3157 for ( ; *fmt && *fmt != ']'; ++fmt, ++len)
3158 set_bit((u8)*fmt, set);
3159
3160 /* no ']' or no character set found */
3161 if (!*fmt || !len)
3162 return num;
3163 ++fmt;
3164
3165 if (negate) {
3166 bitmap_complement(set, set, 256);
3167 /* exclude null '\0' byte */
3168 clear_bit(0, set);
3169 }
3170
3171 /* match must be non-empty */
3172 if (!test_bit((u8)*str, set))
3173 return num;
3174
3175 while (test_bit((u8)*str, set) && field_width--)
3176 *s++ = *str++;
3177 *s = '\0';
3178 ++num;
3179 }
3180 continue;
3181 case 'o':
3182 base = 8;
3183 break;
3184 case 'x':
3185 case 'X':
3186 base = 16;
3187 break;
3188 case 'i':
3189 base = 0;
3190 /* fall through */
3191 case 'd':
3192 is_sign = true;
3193 /* fall through */
3194 case 'u':
3195 break;
3196 case '%':
3197 /* looking for '%' in str */
3198 if (*str++ != '%')
3199 return num;
3200 continue;
3201 default:
3202 /* invalid format; stop here */
3203 return num;
3204 }
3205
3206 /* have some sort of integer conversion.
3207 * first, skip white space in buffer.
3208 */
3209 str = skip_spaces(str);
3210
3211 digit = *str;
3212 if (is_sign && digit == '-')
3213 digit = *(str + 1);
3214
3215 if (!digit
3216 || (base == 16 && !isxdigit(digit))
3217 || (base == 10 && !isdigit(digit))
3218 || (base == 8 && (!isdigit(digit) || digit > '7'))
3219 || (base == 0 && !isdigit(digit)))
3220 break;
3221
3222 if (is_sign)
3223 val.s = qualifier != 'L' ?
3224 simple_strtol(str, &next, base) :
3225 simple_strtoll(str, &next, base);
3226 else
3227 val.u = qualifier != 'L' ?
3228 simple_strtoul(str, &next, base) :
3229 simple_strtoull(str, &next, base);
3230
3231 if (field_width > 0 && next - str > field_width) {
3232 if (base == 0)
3233 _parse_integer_fixup_radix(str, &base);
3234 while (next - str > field_width) {
3235 if (is_sign)
3236 val.s = div_s64(val.s, base);
3237 else
3238 val.u = div_u64(val.u, base);
3239 --next;
3240 }
3241 }
3242
3243 switch (qualifier) {
3244 case 'H': /* that's 'hh' in format */
3245 if (is_sign)
3246 *va_arg(args, signed char *) = val.s;
3247 else
3248 *va_arg(args, unsigned char *) = val.u;
3249 break;
3250 case 'h':
3251 if (is_sign)
3252 *va_arg(args, short *) = val.s;
3253 else
3254 *va_arg(args, unsigned short *) = val.u;
3255 break;
3256 case 'l':
3257 if (is_sign)
3258 *va_arg(args, long *) = val.s;
3259 else
3260 *va_arg(args, unsigned long *) = val.u;
3261 break;
3262 case 'L':
3263 if (is_sign)
3264 *va_arg(args, long long *) = val.s;
3265 else
3266 *va_arg(args, unsigned long long *) = val.u;
3267 break;
3268 case 'z':
3269 *va_arg(args, size_t *) = val.u;
3270 break;
3271 default:
3272 if (is_sign)
3273 *va_arg(args, int *) = val.s;
3274 else
3275 *va_arg(args, unsigned int *) = val.u;
3276 break;
3277 }
3278 num++;
3279
3280 if (!next)
3281 break;
3282 str = next;
3283 }
3284
3285 return num;
3286 }
3287 EXPORT_SYMBOL(vsscanf);
3288
3289 /**
3290 * sscanf - Unformat a buffer into a list of arguments
3291 * @buf: input buffer
3292 * @fmt: formatting of buffer
3293 * @...: resulting arguments
3294 */
3295 int sscanf(const char *buf, const char *fmt, ...)
3296 {
3297 va_list args;
3298 int i;
3299
3300 va_start(args, fmt);
3301 i = vsscanf(buf, fmt, args);
3302 va_end(args);
3303
3304 return i;
3305 }
3306 EXPORT_SYMBOL(sscanf);
Mirror https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git