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56 * This function is obsolete.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81 * This function is obsolete.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95 * This function is obsolete.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