1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Helpers for formatting and printing strings
4 *
5 * Copyright 31 August 2008 James Bottomley
6 * Copyright (C) 2013, Intel Corporation
7 */
8#include <linux/bug.h>
9#include <linux/kernel.h>
10#include <linux/math64.h>
11#include <linux/export.h>
12#include <linux/ctype.h>
13#include <linux/device.h>
14#include <linux/errno.h>
15#include <linux/fs.h>
16#include <linux/limits.h>
17#include <linux/mm.h>
18#include <linux/slab.h>
19#include <linux/string.h>
20#include <linux/string_helpers.h>
21#include <kunit/test.h>
22#include <kunit/test-bug.h>
23
24/**
25 * string_get_size - get the size in the specified units
26 * @size: The size to be converted in blocks
27 * @blk_size: Size of the block (use 1 for size in bytes)
28 * @units: Units to use (powers of 1000 or 1024), whether to include space separator
29 * @buf: buffer to format to
30 * @len: length of buffer
31 *
32 * This function returns a string formatted to 3 significant figures
33 * giving the size in the required units. @buf should have room for
34 * at least 9 bytes and will always be zero terminated.
35 *
36 * Return value: number of characters of output that would have been written
37 * (which may be greater than len, if output was truncated).
38 */
39int string_get_size(u64 size, u64 blk_size, const enum string_size_units units,
40 char *buf, int len)
41{
42 enum string_size_units units_base = units & STRING_UNITS_MASK;
43 static const char *const units_10[] = {
44 "", "k", "M", "G", "T", "P", "E", "Z", "Y",
45 };
46 static const char *const units_2[] = {
47 "", "Ki", "Mi", "Gi", "Ti", "Pi", "Ei", "Zi", "Yi",
48 };
49 static const char *const *const units_str[] = {
50 [STRING_UNITS_10] = units_10,
51 [STRING_UNITS_2] = units_2,
52 };
53 static const unsigned int divisor[] = {
54 [STRING_UNITS_10] = 1000,
55 [STRING_UNITS_2] = 1024,
56 };
57 static const unsigned int rounding[] = { 500, 50, 5 };
58 int i = 0, j;
59 u32 remainder = 0, sf_cap;
60 char tmp[12];
61 const char *unit;
62
63 tmp[0] = '\0';
64
65 if (blk_size == 0)
66 size = 0;
67 if (size == 0)
68 goto out;
69
70 /* This is Napier's algorithm. Reduce the original block size to
71 *
72 * coefficient * divisor[units_base]^i
73 *
74 * we do the reduction so both coefficients are just under 32 bits so
75 * that multiplying them together won't overflow 64 bits and we keep
76 * as much precision as possible in the numbers.
77 *
78 * Note: it's safe to throw away the remainders here because all the
79 * precision is in the coefficients.
80 */
81 while (blk_size >> 32) {
82 do_div(blk_size, divisor[units_base]);
83 i++;
84 }
85
86 while (size >> 32) {
87 do_div(size, divisor[units_base]);
88 i++;
89 }
90
91 /* now perform the actual multiplication keeping i as the sum of the
92 * two logarithms */
93 size *= blk_size;
94
95 /* and logarithmically reduce it until it's just under the divisor */
96 while (size >= divisor[units_base]) {
97 remainder = do_div(size, divisor[units_base]);
98 i++;
99 }
100
101 /* work out in j how many digits of precision we need from the
102 * remainder */
103 sf_cap = size;
104 for (j = 0; sf_cap*10 < 1000; j++)
105 sf_cap *= 10;
106
107 if (units_base == STRING_UNITS_2) {
108 /* express the remainder as a decimal. It's currently the
109 * numerator of a fraction whose denominator is
110 * divisor[units_base], which is 1 << 10 for STRING_UNITS_2 */
111 remainder *= 1000;
112 remainder >>= 10;
113 }
114
115 /* add a 5 to the digit below what will be printed to ensure
116 * an arithmetical round up and carry it through to size */
117 remainder += rounding[j];
118 if (remainder >= 1000) {
119 remainder -= 1000;
120 size += 1;
121 }
122
123 if (j) {
124 snprintf(buf: tmp, size: sizeof(tmp), fmt: ".%03u", remainder);
125 tmp[j+1] = '\0';
126 }
127
128 out:
129 if (i >= ARRAY_SIZE(units_2))
130 unit = "UNK";
131 else
132 unit = units_str[units_base][i];
133
134 return snprintf(buf, size: len, fmt: "%u%s%s%s%s", (u32)size, tmp,
135 (units & STRING_UNITS_NO_SPACE) ? "" : " ",
136 unit,
137 (units & STRING_UNITS_NO_BYTES) ? "" : "B");
138}
139EXPORT_SYMBOL(string_get_size);
140
141int parse_int_array(const char *buf, size_t count, int **array)
142{
143 int *ints, nints;
144
145 get_options(str: buf, nints: 0, ints: &nints);
146 if (!nints)
147 return -ENOENT;
148
149 ints = kcalloc(nints + 1, sizeof(*ints), GFP_KERNEL);
150 if (!ints)
151 return -ENOMEM;
152
153 get_options(str: buf, nints: nints + 1, ints);
154 *array = ints;
155
156 return 0;
157}
158EXPORT_SYMBOL(parse_int_array);
159
160/**
161 * parse_int_array_user - Split string into a sequence of integers
162 * @from: The user space buffer to read from
163 * @count: The maximum number of bytes to read
164 * @array: Returned pointer to sequence of integers
165 *
166 * On success @array is allocated and initialized with a sequence of
167 * integers extracted from the @from plus an additional element that
168 * begins the sequence and specifies the integers count.
169 *
170 * Caller takes responsibility for freeing @array when it is no longer
171 * needed.
172 */
173int parse_int_array_user(const char __user *from, size_t count, int **array)
174{
175 char *buf;
176 int ret;
177
178 buf = memdup_user_nul(from, count);
179 if (IS_ERR(ptr: buf))
180 return PTR_ERR(ptr: buf);
181
182 ret = parse_int_array(buf, count, array);
183 kfree(objp: buf);
184 return ret;
185}
186EXPORT_SYMBOL(parse_int_array_user);
187
188static bool unescape_space(char **src, char **dst)
189{
190 char *p = *dst, *q = *src;
191
192 switch (*q) {
193 case 'n':
194 *p = '\n';
195 break;
196 case 'r':
197 *p = '\r';
198 break;
199 case 't':
200 *p = '\t';
201 break;
202 case 'v':
203 *p = '\v';
204 break;
205 case 'f':
206 *p = '\f';
207 break;
208 default:
209 return false;
210 }
211 *dst += 1;
212 *src += 1;
213 return true;
214}
215
216static bool unescape_octal(char **src, char **dst)
217{
218 char *p = *dst, *q = *src;
219 u8 num;
220
221 if (isodigit(c: *q) == 0)
222 return false;
223
224 num = (*q++) & 7;
225 while (num < 32 && isodigit(c: *q) && (q - *src < 3)) {
226 num <<= 3;
227 num += (*q++) & 7;
228 }
229 *p = num;
230 *dst += 1;
231 *src = q;
232 return true;
233}
234
235static bool unescape_hex(char **src, char **dst)
236{
237 char *p = *dst, *q = *src;
238 int digit;
239 u8 num;
240
241 if (*q++ != 'x')
242 return false;
243
244 num = digit = hex_to_bin(ch: *q++);
245 if (digit < 0)
246 return false;
247
248 digit = hex_to_bin(ch: *q);
249 if (digit >= 0) {
250 q++;
251 num = (num << 4) | digit;
252 }
253 *p = num;
254 *dst += 1;
255 *src = q;
256 return true;
257}
258
259static bool unescape_special(char **src, char **dst)
260{
261 char *p = *dst, *q = *src;
262
263 switch (*q) {
264 case '\"':
265 *p = '\"';
266 break;
267 case '\\':
268 *p = '\\';
269 break;
270 case 'a':
271 *p = '\a';
272 break;
273 case 'e':
274 *p = '\e';
275 break;
276 default:
277 return false;
278 }
279 *dst += 1;
280 *src += 1;
281 return true;
282}
283
284/**
285 * string_unescape - unquote characters in the given string
286 * @src: source buffer (escaped)
287 * @dst: destination buffer (unescaped)
288 * @size: size of the destination buffer (0 to unlimit)
289 * @flags: combination of the flags.
290 *
291 * Description:
292 * The function unquotes characters in the given string.
293 *
294 * Because the size of the output will be the same as or less than the size of
295 * the input, the transformation may be performed in place.
296 *
297 * Caller must provide valid source and destination pointers. Be aware that
298 * destination buffer will always be NULL-terminated. Source string must be
299 * NULL-terminated as well. The supported flags are::
300 *
301 * UNESCAPE_SPACE:
302 * '\f' - form feed
303 * '\n' - new line
304 * '\r' - carriage return
305 * '\t' - horizontal tab
306 * '\v' - vertical tab
307 * UNESCAPE_OCTAL:
308 * '\NNN' - byte with octal value NNN (1 to 3 digits)
309 * UNESCAPE_HEX:
310 * '\xHH' - byte with hexadecimal value HH (1 to 2 digits)
311 * UNESCAPE_SPECIAL:
312 * '\"' - double quote
313 * '\\' - backslash
314 * '\a' - alert (BEL)
315 * '\e' - escape
316 * UNESCAPE_ANY:
317 * all previous together
318 *
319 * Return:
320 * The amount of the characters processed to the destination buffer excluding
321 * trailing '\0' is returned.
322 */
323int string_unescape(char *src, char *dst, size_t size, unsigned int flags)
324{
325 char *out = dst;
326
327 if (!size)
328 size = SIZE_MAX;
329
330 while (*src && --size) {
331 if (src[0] == '\\' && src[1] != '\0' && size > 1) {
332 src++;
333 size--;
334
335 if (flags & UNESCAPE_SPACE &&
336 unescape_space(src: &src, dst: &out))
337 continue;
338
339 if (flags & UNESCAPE_OCTAL &&
340 unescape_octal(src: &src, dst: &out))
341 continue;
342
343 if (flags & UNESCAPE_HEX &&
344 unescape_hex(src: &src, dst: &out))
345 continue;
346
347 if (flags & UNESCAPE_SPECIAL &&
348 unescape_special(src: &src, dst: &out))
349 continue;
350
351 *out++ = '\\';
352 }
353 *out++ = *src++;
354 }
355 *out = '\0';
356
357 return out - dst;
358}
359EXPORT_SYMBOL(string_unescape);
360
361static bool escape_passthrough(unsigned char c, char **dst, char *end)
362{
363 char *out = *dst;
364
365 if (out < end)
366 *out = c;
367 *dst = out + 1;
368 return true;
369}
370
371static bool escape_space(unsigned char c, char **dst, char *end)
372{
373 char *out = *dst;
374 unsigned char to;
375
376 switch (c) {
377 case '\n':
378 to = 'n';
379 break;
380 case '\r':
381 to = 'r';
382 break;
383 case '\t':
384 to = 't';
385 break;
386 case '\v':
387 to = 'v';
388 break;
389 case '\f':
390 to = 'f';
391 break;
392 default:
393 return false;
394 }
395
396 if (out < end)
397 *out = '\\';
398 ++out;
399 if (out < end)
400 *out = to;
401 ++out;
402
403 *dst = out;
404 return true;
405}
406
407static bool escape_special(unsigned char c, char **dst, char *end)
408{
409 char *out = *dst;
410 unsigned char to;
411
412 switch (c) {
413 case '\\':
414 to = '\\';
415 break;
416 case '\a':
417 to = 'a';
418 break;
419 case '\e':
420 to = 'e';
421 break;
422 case '"':
423 to = '"';
424 break;
425 default:
426 return false;
427 }
428
429 if (out < end)
430 *out = '\\';
431 ++out;
432 if (out < end)
433 *out = to;
434 ++out;
435
436 *dst = out;
437 return true;
438}
439
440static bool escape_null(unsigned char c, char **dst, char *end)
441{
442 char *out = *dst;
443
444 if (c)
445 return false;
446
447 if (out < end)
448 *out = '\\';
449 ++out;
450 if (out < end)
451 *out = '0';
452 ++out;
453
454 *dst = out;
455 return true;
456}
457
458static bool escape_octal(unsigned char c, char **dst, char *end)
459{
460 char *out = *dst;
461
462 if (out < end)
463 *out = '\\';
464 ++out;
465 if (out < end)
466 *out = ((c >> 6) & 0x07) + '0';
467 ++out;
468 if (out < end)
469 *out = ((c >> 3) & 0x07) + '0';
470 ++out;
471 if (out < end)
472 *out = ((c >> 0) & 0x07) + '0';
473 ++out;
474
475 *dst = out;
476 return true;
477}
478
479static bool escape_hex(unsigned char c, char **dst, char *end)
480{
481 char *out = *dst;
482
483 if (out < end)
484 *out = '\\';
485 ++out;
486 if (out < end)
487 *out = 'x';
488 ++out;
489 if (out < end)
490 *out = hex_asc_hi(c);
491 ++out;
492 if (out < end)
493 *out = hex_asc_lo(c);
494 ++out;
495
496 *dst = out;
497 return true;
498}
499
500/**
501 * string_escape_mem - quote characters in the given memory buffer
502 * @src: source buffer (unescaped)
503 * @isz: source buffer size
504 * @dst: destination buffer (escaped)
505 * @osz: destination buffer size
506 * @flags: combination of the flags
507 * @only: NULL-terminated string containing characters used to limit
508 * the selected escape class. If characters are included in @only
509 * that would not normally be escaped by the classes selected
510 * in @flags, they will be copied to @dst unescaped.
511 *
512 * Description:
513 * The process of escaping byte buffer includes several parts. They are applied
514 * in the following sequence.
515 *
516 * 1. The character is not matched to the one from @only string and thus
517 * must go as-is to the output.
518 * 2. The character is matched to the printable and ASCII classes, if asked,
519 * and in case of match it passes through to the output.
520 * 3. The character is matched to the printable or ASCII class, if asked,
521 * and in case of match it passes through to the output.
522 * 4. The character is checked if it falls into the class given by @flags.
523 * %ESCAPE_OCTAL and %ESCAPE_HEX are going last since they cover any
524 * character. Note that they actually can't go together, otherwise
525 * %ESCAPE_HEX will be ignored.
526 *
527 * Caller must provide valid source and destination pointers. Be aware that
528 * destination buffer will not be NULL-terminated, thus caller have to append
529 * it if needs. The supported flags are::
530 *
531 * %ESCAPE_SPACE: (special white space, not space itself)
532 * '\f' - form feed
533 * '\n' - new line
534 * '\r' - carriage return
535 * '\t' - horizontal tab
536 * '\v' - vertical tab
537 * %ESCAPE_SPECIAL:
538 * '\"' - double quote
539 * '\\' - backslash
540 * '\a' - alert (BEL)
541 * '\e' - escape
542 * %ESCAPE_NULL:
543 * '\0' - null
544 * %ESCAPE_OCTAL:
545 * '\NNN' - byte with octal value NNN (3 digits)
546 * %ESCAPE_ANY:
547 * all previous together
548 * %ESCAPE_NP:
549 * escape only non-printable characters, checked by isprint()
550 * %ESCAPE_ANY_NP:
551 * all previous together
552 * %ESCAPE_HEX:
553 * '\xHH' - byte with hexadecimal value HH (2 digits)
554 * %ESCAPE_NA:
555 * escape only non-ascii characters, checked by isascii()
556 * %ESCAPE_NAP:
557 * escape only non-printable or non-ascii characters
558 * %ESCAPE_APPEND:
559 * append characters from @only to be escaped by the given classes
560 *
561 * %ESCAPE_APPEND would help to pass additional characters to the escaped, when
562 * one of %ESCAPE_NP, %ESCAPE_NA, or %ESCAPE_NAP is provided.
563 *
564 * One notable caveat, the %ESCAPE_NAP, %ESCAPE_NP and %ESCAPE_NA have the
565 * higher priority than the rest of the flags (%ESCAPE_NAP is the highest).
566 * It doesn't make much sense to use either of them without %ESCAPE_OCTAL
567 * or %ESCAPE_HEX, because they cover most of the other character classes.
568 * %ESCAPE_NAP can utilize %ESCAPE_SPACE or %ESCAPE_SPECIAL in addition to
569 * the above.
570 *
571 * Return:
572 * The total size of the escaped output that would be generated for
573 * the given input and flags. To check whether the output was
574 * truncated, compare the return value to osz. There is room left in
575 * dst for a '\0' terminator if and only if ret < osz.
576 */
577int string_escape_mem(const char *src, size_t isz, char *dst, size_t osz,
578 unsigned int flags, const char *only)
579{
580 char *p = dst;
581 char *end = p + osz;
582 bool is_dict = only && *only;
583 bool is_append = flags & ESCAPE_APPEND;
584
585 while (isz--) {
586 unsigned char c = *src++;
587 bool in_dict = is_dict && strchr(only, c);
588
589 /*
590 * Apply rules in the following sequence:
591 * - the @only string is supplied and does not contain a
592 * character under question
593 * - the character is printable and ASCII, when @flags has
594 * %ESCAPE_NAP bit set
595 * - the character is printable, when @flags has
596 * %ESCAPE_NP bit set
597 * - the character is ASCII, when @flags has
598 * %ESCAPE_NA bit set
599 * - the character doesn't fall into a class of symbols
600 * defined by given @flags
601 * In these cases we just pass through a character to the
602 * output buffer.
603 *
604 * When %ESCAPE_APPEND is passed, the characters from @only
605 * have been excluded from the %ESCAPE_NAP, %ESCAPE_NP, and
606 * %ESCAPE_NA cases.
607 */
608 if (!(is_append || in_dict) && is_dict &&
609 escape_passthrough(c, dst: &p, end))
610 continue;
611
612 if (!(is_append && in_dict) && isascii(c) && isprint(c) &&
613 flags & ESCAPE_NAP && escape_passthrough(c, dst: &p, end))
614 continue;
615
616 if (!(is_append && in_dict) && isprint(c) &&
617 flags & ESCAPE_NP && escape_passthrough(c, dst: &p, end))
618 continue;
619
620 if (!(is_append && in_dict) && isascii(c) &&
621 flags & ESCAPE_NA && escape_passthrough(c, dst: &p, end))
622 continue;
623
624 if (flags & ESCAPE_SPACE && escape_space(c, dst: &p, end))
625 continue;
626
627 if (flags & ESCAPE_SPECIAL && escape_special(c, dst: &p, end))
628 continue;
629
630 if (flags & ESCAPE_NULL && escape_null(c, dst: &p, end))
631 continue;
632
633 /* ESCAPE_OCTAL and ESCAPE_HEX always go last */
634 if (flags & ESCAPE_OCTAL && escape_octal(c, dst: &p, end))
635 continue;
636
637 if (flags & ESCAPE_HEX && escape_hex(c, dst: &p, end))
638 continue;
639
640 escape_passthrough(c, dst: &p, end);
641 }
642
643 return p - dst;
644}
645EXPORT_SYMBOL(string_escape_mem);
646
647/*
648 * Return an allocated string that has been escaped of special characters
649 * and double quotes, making it safe to log in quotes.
650 */
651char *kstrdup_quotable(const char *src, gfp_t gfp)
652{
653 size_t slen, dlen;
654 char *dst;
655 const int flags = ESCAPE_HEX;
656 const char esc[] = "\f\n\r\t\v\a\e\\\"";
657
658 if (!src)
659 return NULL;
660 slen = strlen(src);
661
662 dlen = string_escape_mem(src, slen, NULL, 0, flags, esc);
663 dst = kmalloc(dlen + 1, gfp);
664 if (!dst)
665 return NULL;
666
667 WARN_ON(string_escape_mem(src, slen, dst, dlen, flags, esc) != dlen);
668 dst[dlen] = '\0';
669
670 return dst;
671}
672EXPORT_SYMBOL_GPL(kstrdup_quotable);
673
674/*
675 * Returns allocated NULL-terminated string containing process
676 * command line, with inter-argument NULLs replaced with spaces,
677 * and other special characters escaped.
678 */
679char *kstrdup_quotable_cmdline(struct task_struct *task, gfp_t gfp)
680{
681 char *buffer, *quoted;
682 int i, res;
683
684 buffer = kmalloc(PAGE_SIZE, GFP_KERNEL);
685 if (!buffer)
686 return NULL;
687
688 res = get_cmdline(task, buffer, PAGE_SIZE - 1);
689 buffer[res] = '\0';
690
691 /* Collapse trailing NULLs, leave res pointing to last non-NULL. */
692 while (--res >= 0 && buffer[res] == '\0')
693 ;
694
695 /* Replace inter-argument NULLs. */
696 for (i = 0; i <= res; i++)
697 if (buffer[i] == '\0')
698 buffer[i] = ' ';
699
700 /* Make sure result is printable. */
701 quoted = kstrdup_quotable(buffer, gfp);
702 kfree(objp: buffer);
703 return quoted;
704}
705EXPORT_SYMBOL_GPL(kstrdup_quotable_cmdline);
706
707/*
708 * Returns allocated NULL-terminated string containing pathname,
709 * with special characters escaped, able to be safely logged. If
710 * there is an error, the leading character will be "<".
711 */
712char *kstrdup_quotable_file(struct file *file, gfp_t gfp)
713{
714 char *temp, *pathname;
715
716 if (!file)
717 return kstrdup(s: "<unknown>", gfp);
718
719 /* We add 11 spaces for ' (deleted)' to be appended */
720 temp = kmalloc(PATH_MAX + 11, GFP_KERNEL);
721 if (!temp)
722 return kstrdup(s: "<no_memory>", gfp);
723
724 pathname = file_path(file, temp, PATH_MAX + 11);
725 if (IS_ERR(ptr: pathname))
726 pathname = kstrdup(s: "<too_long>", gfp);
727 else
728 pathname = kstrdup_quotable(pathname, gfp);
729
730 kfree(objp: temp);
731 return pathname;
732}
733EXPORT_SYMBOL_GPL(kstrdup_quotable_file);
734
735/*
736 * Returns duplicate string in which the @old characters are replaced by @new.
737 */
738char *kstrdup_and_replace(const char *src, char old, char new, gfp_t gfp)
739{
740 char *dst;
741
742 dst = kstrdup(s: src, gfp);
743 if (!dst)
744 return NULL;
745
746 return strreplace(str: dst, old, new);
747}
748EXPORT_SYMBOL_GPL(kstrdup_and_replace);
749
750/**
751 * kasprintf_strarray - allocate and fill array of sequential strings
752 * @gfp: flags for the slab allocator
753 * @prefix: prefix to be used
754 * @n: amount of lines to be allocated and filled
755 *
756 * Allocates and fills @n strings using pattern "%s-%zu", where prefix
757 * is provided by caller. The caller is responsible to free them with
758 * kfree_strarray() after use.
759 *
760 * Returns array of strings or NULL when memory can't be allocated.
761 */
762char **kasprintf_strarray(gfp_t gfp, const char *prefix, size_t n)
763{
764 char **names;
765 size_t i;
766
767 names = kcalloc(n + 1, sizeof(char *), gfp);
768 if (!names)
769 return NULL;
770
771 for (i = 0; i < n; i++) {
772 names[i] = kasprintf(gfp, fmt: "%s-%zu", prefix, i);
773 if (!names[i]) {
774 kfree_strarray(array: names, n: i);
775 return NULL;
776 }
777 }
778
779 return names;
780}
781EXPORT_SYMBOL_GPL(kasprintf_strarray);
782
783/**
784 * kfree_strarray - free a number of dynamically allocated strings contained
785 * in an array and the array itself
786 *
787 * @array: Dynamically allocated array of strings to free.
788 * @n: Number of strings (starting from the beginning of the array) to free.
789 *
790 * Passing a non-NULL @array and @n == 0 as well as NULL @array are valid
791 * use-cases. If @array is NULL, the function does nothing.
792 */
793void kfree_strarray(char **array, size_t n)
794{
795 unsigned int i;
796
797 if (!array)
798 return;
799
800 for (i = 0; i < n; i++)
801 kfree(objp: array[i]);
802 kfree(objp: array);
803}
804EXPORT_SYMBOL_GPL(kfree_strarray);
805
806struct strarray {
807 char **array;
808 size_t n;
809};
810
811static void devm_kfree_strarray(struct device *dev, void *res)
812{
813 struct strarray *array = res;
814
815 kfree_strarray(array->array, array->n);
816}
817
818char **devm_kasprintf_strarray(struct device *dev, const char *prefix, size_t n)
819{
820 struct strarray *ptr;
821
822 ptr = devres_alloc(devm_kfree_strarray, sizeof(*ptr), GFP_KERNEL);
823 if (!ptr)
824 return ERR_PTR(error: -ENOMEM);
825
826 ptr->array = kasprintf_strarray(GFP_KERNEL, prefix, n);
827 if (!ptr->array) {
828 devres_free(res: ptr);
829 return ERR_PTR(error: -ENOMEM);
830 }
831
832 ptr->n = n;
833 devres_add(dev, res: ptr);
834
835 return ptr->array;
836}
837EXPORT_SYMBOL_GPL(devm_kasprintf_strarray);
838
839/**
840 * skip_spaces - Removes leading whitespace from @str.
841 * @str: The string to be stripped.
842 *
843 * Returns a pointer to the first non-whitespace character in @str.
844 */
845char *skip_spaces(const char *str)
846{
847 while (isspace(*str))
848 ++str;
849 return (char *)str;
850}
851EXPORT_SYMBOL(skip_spaces);
852
853/**
854 * strim - Removes leading and trailing whitespace from @s.
855 * @s: The string to be stripped.
856 *
857 * Note that the first trailing whitespace is replaced with a %NUL-terminator
858 * in the given string @s. Returns a pointer to the first non-whitespace
859 * character in @s.
860 */
861char *strim(char *s)
862{
863 size_t size;
864 char *end;
865
866 size = strlen(s);
867 if (!size)
868 return s;
869
870 end = s + size - 1;
871 while (end >= s && isspace(*end))
872 end--;
873 *(end + 1) = '\0';
874
875 return skip_spaces(s);
876}
877EXPORT_SYMBOL(strim);
878
879/**
880 * sysfs_streq - return true if strings are equal, modulo trailing newline
881 * @s1: one string
882 * @s2: another string
883 *
884 * This routine returns true iff two strings are equal, treating both
885 * NUL and newline-then-NUL as equivalent string terminations. It's
886 * geared for use with sysfs input strings, which generally terminate
887 * with newlines but are compared against values without newlines.
888 */
889bool sysfs_streq(const char *s1, const char *s2)
890{
891 while (*s1 && *s1 == *s2) {
892 s1++;
893 s2++;
894 }
895
896 if (*s1 == *s2)
897 return true;
898 if (!*s1 && *s2 == '\n' && !s2[1])
899 return true;
900 if (*s1 == '\n' && !s1[1] && !*s2)
901 return true;
902 return false;
903}
904EXPORT_SYMBOL(sysfs_streq);
905
906/**
907 * match_string - matches given string in an array
908 * @array: array of strings
909 * @n: number of strings in the array or -1 for NULL terminated arrays
910 * @string: string to match with
911 *
912 * This routine will look for a string in an array of strings up to the
913 * n-th element in the array or until the first NULL element.
914 *
915 * Historically the value of -1 for @n, was used to search in arrays that
916 * are NULL terminated. However, the function does not make a distinction
917 * when finishing the search: either @n elements have been compared OR
918 * the first NULL element was found.
919 *
920 * Return:
921 * index of a @string in the @array if matches, or %-EINVAL otherwise.
922 */
923int match_string(const char * const *array, size_t n, const char *string)
924{
925 int index;
926 const char *item;
927
928 for (index = 0; index < n; index++) {
929 item = array[index];
930 if (!item)
931 break;
932 if (!strcmp(item, string))
933 return index;
934 }
935
936 return -EINVAL;
937}
938EXPORT_SYMBOL(match_string);
939
940/**
941 * __sysfs_match_string - matches given string in an array
942 * @array: array of strings
943 * @n: number of strings in the array or -1 for NULL terminated arrays
944 * @str: string to match with
945 *
946 * Returns index of @str in the @array or -EINVAL, just like match_string().
947 * Uses sysfs_streq instead of strcmp for matching.
948 *
949 * This routine will look for a string in an array of strings up to the
950 * n-th element in the array or until the first NULL element.
951 *
952 * Historically the value of -1 for @n, was used to search in arrays that
953 * are NULL terminated. However, the function does not make a distinction
954 * when finishing the search: either @n elements have been compared OR
955 * the first NULL element was found.
956 */
957int __sysfs_match_string(const char * const *array, size_t n, const char *str)
958{
959 const char *item;
960 int index;
961
962 for (index = 0; index < n; index++) {
963 item = array[index];
964 if (!item)
965 break;
966 if (sysfs_streq(item, str))
967 return index;
968 }
969
970 return -EINVAL;
971}
972EXPORT_SYMBOL(__sysfs_match_string);
973
974/**
975 * strreplace - Replace all occurrences of character in string.
976 * @str: The string to operate on.
977 * @old: The character being replaced.
978 * @new: The character @old is replaced with.
979 *
980 * Replaces the each @old character with a @new one in the given string @str.
981 *
982 * Return: pointer to the string @str itself.
983 */
984char *strreplace(char *str, char old, char new)
985{
986 char *s = str;
987
988 for (; *s; ++s)
989 if (*s == old)
990 *s = new;
991 return str;
992}
993EXPORT_SYMBOL(strreplace);
994
995/**
996 * memcpy_and_pad - Copy one buffer to another with padding
997 * @dest: Where to copy to
998 * @dest_len: The destination buffer size
999 * @src: Where to copy from
1000 * @count: The number of bytes to copy
1001 * @pad: Character to use for padding if space is left in destination.
1002 */
1003void memcpy_and_pad(void *dest, size_t dest_len, const void *src, size_t count,
1004 int pad)
1005{
1006 if (dest_len > count) {
1007 memcpy(to: dest, from: src, len: count);
1008 memset(s: dest + count, c: pad, n: dest_len - count);
1009 } else {
1010 memcpy(to: dest, from: src, len: dest_len);
1011 }
1012}
1013EXPORT_SYMBOL(memcpy_and_pad);
1014
1015#ifdef CONFIG_FORTIFY_SOURCE
1016/* These are placeholders for fortify compile-time warnings. */
1017void __read_overflow2_field(size_t avail, size_t wanted) { }
1018EXPORT_SYMBOL(__read_overflow2_field);
1019void __write_overflow_field(size_t avail, size_t wanted) { }
1020EXPORT_SYMBOL(__write_overflow_field);
1021
1022static const char * const fortify_func_name[] = {
1023#define MAKE_FORTIFY_FUNC_NAME(func) [MAKE_FORTIFY_FUNC(func)] = #func
1024 EACH_FORTIFY_FUNC(MAKE_FORTIFY_FUNC_NAME)
1025#undef MAKE_FORTIFY_FUNC_NAME
1026};
1027
1028void __fortify_report(const u8 reason, const size_t avail, const size_t size)
1029{
1030 const u8 func = FORTIFY_REASON_FUNC(reason);
1031 const bool write = FORTIFY_REASON_DIR(reason);
1032 const char *name;
1033
1034 name = fortify_func_name[umin(func, FORTIFY_FUNC_UNKNOWN)];
1035 WARN(1, "%s: detected buffer overflow: %zu byte %s of buffer size %zu\n",
1036 name, size, str_read_write(!write), avail);
1037}
1038EXPORT_SYMBOL(__fortify_report);
1039
1040void __fortify_panic(const u8 reason, const size_t avail, const size_t size)
1041{
1042 __fortify_report(reason, avail, size);
1043 BUG();
1044}
1045EXPORT_SYMBOL(__fortify_panic);
1046#endif /* CONFIG_FORTIFY_SOURCE */
1047