Line data Source code
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 :
22 : /**
23 : * string_get_size - get the size in the specified units
24 : * @size: The size to be converted in blocks
25 : * @blk_size: Size of the block (use 1 for size in bytes)
26 : * @units: units to use (powers of 1000 or 1024)
27 : * @buf: buffer to format to
28 : * @len: length of buffer
29 : *
30 : * This function returns a string formatted to 3 significant figures
31 : * giving the size in the required units. @buf should have room for
32 : * at least 9 bytes and will always be zero terminated.
33 : *
34 : */
35 0 : void string_get_size(u64 size, u64 blk_size, const enum string_size_units units,
36 : char *buf, int len)
37 : {
38 : static const char *const units_10[] = {
39 : "B", "kB", "MB", "GB", "TB", "PB", "EB", "ZB", "YB"
40 : };
41 : static const char *const units_2[] = {
42 : "B", "KiB", "MiB", "GiB", "TiB", "PiB", "EiB", "ZiB", "YiB"
43 : };
44 : static const char *const *const units_str[] = {
45 : [STRING_UNITS_10] = units_10,
46 : [STRING_UNITS_2] = units_2,
47 : };
48 : static const unsigned int divisor[] = {
49 : [STRING_UNITS_10] = 1000,
50 : [STRING_UNITS_2] = 1024,
51 : };
52 : static const unsigned int rounding[] = { 500, 50, 5 };
53 0 : int i = 0, j;
54 0 : u32 remainder = 0, sf_cap;
55 : char tmp[8];
56 : const char *unit;
57 :
58 0 : tmp[0] = '\0';
59 :
60 0 : if (blk_size == 0)
61 0 : size = 0;
62 0 : if (size == 0)
63 : goto out;
64 :
65 : /* This is Napier's algorithm. Reduce the original block size to
66 : *
67 : * coefficient * divisor[units]^i
68 : *
69 : * we do the reduction so both coefficients are just under 32 bits so
70 : * that multiplying them together won't overflow 64 bits and we keep
71 : * as much precision as possible in the numbers.
72 : *
73 : * Note: it's safe to throw away the remainders here because all the
74 : * precision is in the coefficients.
75 : */
76 0 : while (blk_size >> 32) {
77 0 : do_div(blk_size, divisor[units]);
78 0 : i++;
79 : }
80 :
81 0 : while (size >> 32) {
82 0 : do_div(size, divisor[units]);
83 0 : i++;
84 : }
85 :
86 : /* now perform the actual multiplication keeping i as the sum of the
87 : * two logarithms */
88 0 : size *= blk_size;
89 :
90 : /* and logarithmically reduce it until it's just under the divisor */
91 0 : while (size >= divisor[units]) {
92 0 : remainder = do_div(size, divisor[units]);
93 0 : i++;
94 : }
95 :
96 : /* work out in j how many digits of precision we need from the
97 : * remainder */
98 0 : sf_cap = size;
99 0 : for (j = 0; sf_cap*10 < 1000; j++)
100 0 : sf_cap *= 10;
101 :
102 0 : if (units == STRING_UNITS_2) {
103 : /* express the remainder as a decimal. It's currently the
104 : * numerator of a fraction whose denominator is
105 : * divisor[units], which is 1 << 10 for STRING_UNITS_2 */
106 0 : remainder *= 1000;
107 0 : remainder >>= 10;
108 : }
109 :
110 : /* add a 5 to the digit below what will be printed to ensure
111 : * an arithmetical round up and carry it through to size */
112 0 : remainder += rounding[j];
113 0 : if (remainder >= 1000) {
114 0 : remainder -= 1000;
115 0 : size += 1;
116 : }
117 :
118 0 : if (j) {
119 0 : snprintf(tmp, sizeof(tmp), ".%03u", remainder);
120 0 : tmp[j+1] = '\0';
121 : }
122 :
123 : out:
124 0 : if (i >= ARRAY_SIZE(units_2))
125 : unit = "UNK";
126 : else
127 0 : unit = units_str[units][i];
128 :
129 0 : snprintf(buf, len, "%u%s %s", (u32)size,
130 : tmp, unit);
131 0 : }
132 : EXPORT_SYMBOL(string_get_size);
133 :
134 0 : static bool unescape_space(char **src, char **dst)
135 : {
136 0 : char *p = *dst, *q = *src;
137 :
138 0 : switch (*q) {
139 : case 'n':
140 0 : *p = '\n';
141 0 : break;
142 : case 'r':
143 0 : *p = '\r';
144 0 : break;
145 : case 't':
146 0 : *p = '\t';
147 0 : break;
148 : case 'v':
149 0 : *p = '\v';
150 0 : break;
151 : case 'f':
152 0 : *p = '\f';
153 0 : break;
154 : default:
155 : return false;
156 : }
157 0 : *dst += 1;
158 0 : *src += 1;
159 0 : return true;
160 : }
161 :
162 0 : static bool unescape_octal(char **src, char **dst)
163 : {
164 0 : char *p = *dst, *q = *src;
165 : u8 num;
166 :
167 0 : if (isodigit(*q) == 0)
168 : return false;
169 :
170 0 : num = (*q++) & 7;
171 0 : while (num < 32 && isodigit(*q) && (q - *src < 3)) {
172 0 : num <<= 3;
173 0 : num += (*q++) & 7;
174 : }
175 0 : *p = num;
176 0 : *dst += 1;
177 0 : *src = q;
178 0 : return true;
179 : }
180 :
181 0 : static bool unescape_hex(char **src, char **dst)
182 : {
183 0 : char *p = *dst, *q = *src;
184 : int digit;
185 : u8 num;
186 :
187 0 : if (*q++ != 'x')
188 : return false;
189 :
190 0 : num = digit = hex_to_bin(*q++);
191 0 : if (digit < 0)
192 : return false;
193 :
194 0 : digit = hex_to_bin(*q);
195 0 : if (digit >= 0) {
196 0 : q++;
197 0 : num = (num << 4) | digit;
198 : }
199 0 : *p = num;
200 0 : *dst += 1;
201 0 : *src = q;
202 0 : return true;
203 : }
204 :
205 0 : static bool unescape_special(char **src, char **dst)
206 : {
207 0 : char *p = *dst, *q = *src;
208 :
209 0 : switch (*q) {
210 : case '\"':
211 0 : *p = '\"';
212 0 : break;
213 : case '\\':
214 0 : *p = '\\';
215 0 : break;
216 : case 'a':
217 0 : *p = '\a';
218 0 : break;
219 : case 'e':
220 0 : *p = '\e';
221 0 : break;
222 : default:
223 : return false;
224 : }
225 0 : *dst += 1;
226 0 : *src += 1;
227 0 : return true;
228 : }
229 :
230 : /**
231 : * string_unescape - unquote characters in the given string
232 : * @src: source buffer (escaped)
233 : * @dst: destination buffer (unescaped)
234 : * @size: size of the destination buffer (0 to unlimit)
235 : * @flags: combination of the flags.
236 : *
237 : * Description:
238 : * The function unquotes characters in the given string.
239 : *
240 : * Because the size of the output will be the same as or less than the size of
241 : * the input, the transformation may be performed in place.
242 : *
243 : * Caller must provide valid source and destination pointers. Be aware that
244 : * destination buffer will always be NULL-terminated. Source string must be
245 : * NULL-terminated as well. The supported flags are::
246 : *
247 : * UNESCAPE_SPACE:
248 : * '\f' - form feed
249 : * '\n' - new line
250 : * '\r' - carriage return
251 : * '\t' - horizontal tab
252 : * '\v' - vertical tab
253 : * UNESCAPE_OCTAL:
254 : * '\NNN' - byte with octal value NNN (1 to 3 digits)
255 : * UNESCAPE_HEX:
256 : * '\xHH' - byte with hexadecimal value HH (1 to 2 digits)
257 : * UNESCAPE_SPECIAL:
258 : * '\"' - double quote
259 : * '\\' - backslash
260 : * '\a' - alert (BEL)
261 : * '\e' - escape
262 : * UNESCAPE_ANY:
263 : * all previous together
264 : *
265 : * Return:
266 : * The amount of the characters processed to the destination buffer excluding
267 : * trailing '\0' is returned.
268 : */
269 0 : int string_unescape(char *src, char *dst, size_t size, unsigned int flags)
270 : {
271 0 : char *out = dst;
272 :
273 0 : while (*src && --size) {
274 0 : if (src[0] == '\\' && src[1] != '\0' && size > 1) {
275 0 : src++;
276 0 : size--;
277 :
278 0 : if (flags & UNESCAPE_SPACE &&
279 0 : unescape_space(&src, &out))
280 0 : continue;
281 :
282 0 : if (flags & UNESCAPE_OCTAL &&
283 0 : unescape_octal(&src, &out))
284 0 : continue;
285 :
286 0 : if (flags & UNESCAPE_HEX &&
287 0 : unescape_hex(&src, &out))
288 0 : continue;
289 :
290 0 : if (flags & UNESCAPE_SPECIAL &&
291 0 : unescape_special(&src, &out))
292 0 : continue;
293 :
294 0 : *out++ = '\\';
295 : }
296 0 : *out++ = *src++;
297 : }
298 0 : *out = '\0';
299 :
300 0 : return out - dst;
301 : }
302 : EXPORT_SYMBOL(string_unescape);
303 :
304 : static bool escape_passthrough(unsigned char c, char **dst, char *end)
305 : {
306 0 : char *out = *dst;
307 :
308 0 : if (out < end)
309 0 : *out = c;
310 0 : *dst = out + 1;
311 : return true;
312 : }
313 :
314 0 : static bool escape_space(unsigned char c, char **dst, char *end)
315 : {
316 0 : char *out = *dst;
317 : unsigned char to;
318 :
319 0 : switch (c) {
320 : case '\n':
321 : to = 'n';
322 : break;
323 : case '\r':
324 0 : to = 'r';
325 0 : break;
326 : case '\t':
327 0 : to = 't';
328 0 : break;
329 : case '\v':
330 0 : to = 'v';
331 0 : break;
332 : case '\f':
333 0 : to = 'f';
334 0 : break;
335 : default:
336 : return false;
337 : }
338 :
339 0 : if (out < end)
340 0 : *out = '\\';
341 0 : ++out;
342 0 : if (out < end)
343 0 : *out = to;
344 0 : ++out;
345 :
346 0 : *dst = out;
347 0 : return true;
348 : }
349 :
350 : static bool escape_special(unsigned char c, char **dst, char *end)
351 : {
352 0 : char *out = *dst;
353 : unsigned char to;
354 :
355 0 : switch (c) {
356 : case '\\':
357 : to = '\\';
358 : break;
359 : case '\a':
360 0 : to = 'a';
361 : break;
362 : case '\e':
363 0 : to = 'e';
364 : break;
365 : case '"':
366 0 : to = '"';
367 : break;
368 : default:
369 : return false;
370 : }
371 :
372 0 : if (out < end)
373 0 : *out = '\\';
374 0 : ++out;
375 0 : if (out < end)
376 0 : *out = to;
377 0 : ++out;
378 :
379 0 : *dst = out;
380 : return true;
381 : }
382 :
383 : static bool escape_null(unsigned char c, char **dst, char *end)
384 : {
385 0 : char *out = *dst;
386 :
387 0 : if (c)
388 : return false;
389 :
390 0 : if (out < end)
391 0 : *out = '\\';
392 0 : ++out;
393 0 : if (out < end)
394 0 : *out = '0';
395 0 : ++out;
396 :
397 0 : *dst = out;
398 : return true;
399 : }
400 :
401 0 : static bool escape_octal(unsigned char c, char **dst, char *end)
402 : {
403 0 : char *out = *dst;
404 :
405 0 : if (out < end)
406 0 : *out = '\\';
407 0 : ++out;
408 0 : if (out < end)
409 0 : *out = ((c >> 6) & 0x07) + '0';
410 0 : ++out;
411 0 : if (out < end)
412 0 : *out = ((c >> 3) & 0x07) + '0';
413 0 : ++out;
414 0 : if (out < end)
415 0 : *out = ((c >> 0) & 0x07) + '0';
416 0 : ++out;
417 :
418 0 : *dst = out;
419 0 : return true;
420 : }
421 :
422 : static bool escape_hex(unsigned char c, char **dst, char *end)
423 : {
424 0 : char *out = *dst;
425 :
426 0 : if (out < end)
427 0 : *out = '\\';
428 0 : ++out;
429 0 : if (out < end)
430 0 : *out = 'x';
431 0 : ++out;
432 0 : if (out < end)
433 0 : *out = hex_asc_hi(c);
434 0 : ++out;
435 0 : if (out < end)
436 0 : *out = hex_asc_lo(c);
437 0 : ++out;
438 :
439 0 : *dst = out;
440 : return true;
441 : }
442 :
443 : /**
444 : * string_escape_mem - quote characters in the given memory buffer
445 : * @src: source buffer (unescaped)
446 : * @isz: source buffer size
447 : * @dst: destination buffer (escaped)
448 : * @osz: destination buffer size
449 : * @flags: combination of the flags
450 : * @only: NULL-terminated string containing characters used to limit
451 : * the selected escape class. If characters are included in @only
452 : * that would not normally be escaped by the classes selected
453 : * in @flags, they will be copied to @dst unescaped.
454 : *
455 : * Description:
456 : * The process of escaping byte buffer includes several parts. They are applied
457 : * in the following sequence.
458 : *
459 : * 1. The character is not matched to the one from @only string and thus
460 : * must go as-is to the output.
461 : * 2. The character is matched to the printable and ASCII classes, if asked,
462 : * and in case of match it passes through to the output.
463 : * 3. The character is matched to the printable or ASCII class, if asked,
464 : * and in case of match it passes through to the output.
465 : * 4. The character is checked if it falls into the class given by @flags.
466 : * %ESCAPE_OCTAL and %ESCAPE_HEX are going last since they cover any
467 : * character. Note that they actually can't go together, otherwise
468 : * %ESCAPE_HEX will be ignored.
469 : *
470 : * Caller must provide valid source and destination pointers. Be aware that
471 : * destination buffer will not be NULL-terminated, thus caller have to append
472 : * it if needs. The supported flags are::
473 : *
474 : * %ESCAPE_SPACE: (special white space, not space itself)
475 : * '\f' - form feed
476 : * '\n' - new line
477 : * '\r' - carriage return
478 : * '\t' - horizontal tab
479 : * '\v' - vertical tab
480 : * %ESCAPE_SPECIAL:
481 : * '\"' - double quote
482 : * '\\' - backslash
483 : * '\a' - alert (BEL)
484 : * '\e' - escape
485 : * %ESCAPE_NULL:
486 : * '\0' - null
487 : * %ESCAPE_OCTAL:
488 : * '\NNN' - byte with octal value NNN (3 digits)
489 : * %ESCAPE_ANY:
490 : * all previous together
491 : * %ESCAPE_NP:
492 : * escape only non-printable characters, checked by isprint()
493 : * %ESCAPE_ANY_NP:
494 : * all previous together
495 : * %ESCAPE_HEX:
496 : * '\xHH' - byte with hexadecimal value HH (2 digits)
497 : * %ESCAPE_NA:
498 : * escape only non-ascii characters, checked by isascii()
499 : * %ESCAPE_NAP:
500 : * escape only non-printable or non-ascii characters
501 : * %ESCAPE_APPEND:
502 : * append characters from @only to be escaped by the given classes
503 : *
504 : * %ESCAPE_APPEND would help to pass additional characters to the escaped, when
505 : * one of %ESCAPE_NP, %ESCAPE_NA, or %ESCAPE_NAP is provided.
506 : *
507 : * One notable caveat, the %ESCAPE_NAP, %ESCAPE_NP and %ESCAPE_NA have the
508 : * higher priority than the rest of the flags (%ESCAPE_NAP is the highest).
509 : * It doesn't make much sense to use either of them without %ESCAPE_OCTAL
510 : * or %ESCAPE_HEX, because they cover most of the other character classes.
511 : * %ESCAPE_NAP can utilize %ESCAPE_SPACE or %ESCAPE_SPECIAL in addition to
512 : * the above.
513 : *
514 : * Return:
515 : * The total size of the escaped output that would be generated for
516 : * the given input and flags. To check whether the output was
517 : * truncated, compare the return value to osz. There is room left in
518 : * dst for a '\0' terminator if and only if ret < osz.
519 : */
520 0 : int string_escape_mem(const char *src, size_t isz, char *dst, size_t osz,
521 : unsigned int flags, const char *only)
522 : {
523 0 : char *p = dst;
524 0 : char *end = p + osz;
525 0 : bool is_dict = only && *only;
526 0 : bool is_append = flags & ESCAPE_APPEND;
527 :
528 0 : while (isz--) {
529 0 : unsigned char c = *src++;
530 0 : bool in_dict = is_dict && strchr(only, c);
531 :
532 : /*
533 : * Apply rules in the following sequence:
534 : * - the @only string is supplied and does not contain a
535 : * character under question
536 : * - the character is printable and ASCII, when @flags has
537 : * %ESCAPE_NAP bit set
538 : * - the character is printable, when @flags has
539 : * %ESCAPE_NP bit set
540 : * - the character is ASCII, when @flags has
541 : * %ESCAPE_NA bit set
542 : * - the character doesn't fall into a class of symbols
543 : * defined by given @flags
544 : * In these cases we just pass through a character to the
545 : * output buffer.
546 : *
547 : * When %ESCAPE_APPEND is passed, the characters from @only
548 : * have been excluded from the %ESCAPE_NAP, %ESCAPE_NP, and
549 : * %ESCAPE_NA cases.
550 : */
551 0 : if (!(is_append || in_dict) && is_dict &&
552 0 : escape_passthrough(c, &p, end))
553 0 : continue;
554 :
555 0 : if (!(is_append && in_dict) && isascii(c) && isprint(c) &&
556 0 : flags & ESCAPE_NAP && escape_passthrough(c, &p, end))
557 0 : continue;
558 :
559 0 : if (!(is_append && in_dict) && isprint(c) &&
560 0 : flags & ESCAPE_NP && escape_passthrough(c, &p, end))
561 0 : continue;
562 :
563 0 : if (!(is_append && in_dict) && isascii(c) &&
564 0 : flags & ESCAPE_NA && escape_passthrough(c, &p, end))
565 0 : continue;
566 :
567 0 : if (flags & ESCAPE_SPACE && escape_space(c, &p, end))
568 0 : continue;
569 :
570 0 : if (flags & ESCAPE_SPECIAL && escape_special(c, &p, end))
571 0 : continue;
572 :
573 0 : if (flags & ESCAPE_NULL && escape_null(c, &p, end))
574 0 : continue;
575 :
576 : /* ESCAPE_OCTAL and ESCAPE_HEX always go last */
577 0 : if (flags & ESCAPE_OCTAL && escape_octal(c, &p, end))
578 0 : continue;
579 :
580 0 : if (flags & ESCAPE_HEX && escape_hex(c, &p, end))
581 0 : continue;
582 :
583 : escape_passthrough(c, &p, end);
584 : }
585 :
586 0 : return p - dst;
587 : }
588 : EXPORT_SYMBOL(string_escape_mem);
589 :
590 : /*
591 : * Return an allocated string that has been escaped of special characters
592 : * and double quotes, making it safe to log in quotes.
593 : */
594 0 : char *kstrdup_quotable(const char *src, gfp_t gfp)
595 : {
596 : size_t slen, dlen;
597 : char *dst;
598 0 : const int flags = ESCAPE_HEX;
599 0 : const char esc[] = "\f\n\r\t\v\a\e\\\"";
600 :
601 0 : if (!src)
602 : return NULL;
603 0 : slen = strlen(src);
604 :
605 0 : dlen = string_escape_mem(src, slen, NULL, 0, flags, esc);
606 0 : dst = kmalloc(dlen + 1, gfp);
607 0 : if (!dst)
608 : return NULL;
609 :
610 0 : WARN_ON(string_escape_mem(src, slen, dst, dlen, flags, esc) != dlen);
611 0 : dst[dlen] = '\0';
612 :
613 0 : return dst;
614 : }
615 : EXPORT_SYMBOL_GPL(kstrdup_quotable);
616 :
617 : /*
618 : * Returns allocated NULL-terminated string containing process
619 : * command line, with inter-argument NULLs replaced with spaces,
620 : * and other special characters escaped.
621 : */
622 0 : char *kstrdup_quotable_cmdline(struct task_struct *task, gfp_t gfp)
623 : {
624 : char *buffer, *quoted;
625 : int i, res;
626 :
627 0 : buffer = kmalloc(PAGE_SIZE, GFP_KERNEL);
628 0 : if (!buffer)
629 : return NULL;
630 :
631 0 : res = get_cmdline(task, buffer, PAGE_SIZE - 1);
632 0 : buffer[res] = '\0';
633 :
634 : /* Collapse trailing NULLs, leave res pointing to last non-NULL. */
635 0 : while (--res >= 0 && buffer[res] == '\0')
636 : ;
637 :
638 : /* Replace inter-argument NULLs. */
639 0 : for (i = 0; i <= res; i++)
640 0 : if (buffer[i] == '\0')
641 0 : buffer[i] = ' ';
642 :
643 : /* Make sure result is printable. */
644 0 : quoted = kstrdup_quotable(buffer, gfp);
645 0 : kfree(buffer);
646 0 : return quoted;
647 : }
648 : EXPORT_SYMBOL_GPL(kstrdup_quotable_cmdline);
649 :
650 : /*
651 : * Returns allocated NULL-terminated string containing pathname,
652 : * with special characters escaped, able to be safely logged. If
653 : * there is an error, the leading character will be "<".
654 : */
655 0 : char *kstrdup_quotable_file(struct file *file, gfp_t gfp)
656 : {
657 : char *temp, *pathname;
658 :
659 0 : if (!file)
660 0 : return kstrdup("<unknown>", gfp);
661 :
662 : /* We add 11 spaces for ' (deleted)' to be appended */
663 0 : temp = kmalloc(PATH_MAX + 11, GFP_KERNEL);
664 0 : if (!temp)
665 0 : return kstrdup("<no_memory>", gfp);
666 :
667 0 : pathname = file_path(file, temp, PATH_MAX + 11);
668 0 : if (IS_ERR(pathname))
669 0 : pathname = kstrdup("<too_long>", gfp);
670 : else
671 0 : pathname = kstrdup_quotable(pathname, gfp);
672 :
673 0 : kfree(temp);
674 0 : return pathname;
675 : }
676 : EXPORT_SYMBOL_GPL(kstrdup_quotable_file);
677 :
678 : /**
679 : * kasprintf_strarray - allocate and fill array of sequential strings
680 : * @gfp: flags for the slab allocator
681 : * @prefix: prefix to be used
682 : * @n: amount of lines to be allocated and filled
683 : *
684 : * Allocates and fills @n strings using pattern "%s-%zu", where prefix
685 : * is provided by caller. The caller is responsible to free them with
686 : * kfree_strarray() after use.
687 : *
688 : * Returns array of strings or NULL when memory can't be allocated.
689 : */
690 0 : char **kasprintf_strarray(gfp_t gfp, const char *prefix, size_t n)
691 : {
692 : char **names;
693 : size_t i;
694 :
695 0 : names = kcalloc(n + 1, sizeof(char *), gfp);
696 0 : if (!names)
697 : return NULL;
698 :
699 0 : for (i = 0; i < n; i++) {
700 0 : names[i] = kasprintf(gfp, "%s-%zu", prefix, i);
701 0 : if (!names[i]) {
702 0 : kfree_strarray(names, i);
703 0 : return NULL;
704 : }
705 : }
706 :
707 : return names;
708 : }
709 : EXPORT_SYMBOL_GPL(kasprintf_strarray);
710 :
711 : /**
712 : * kfree_strarray - free a number of dynamically allocated strings contained
713 : * in an array and the array itself
714 : *
715 : * @array: Dynamically allocated array of strings to free.
716 : * @n: Number of strings (starting from the beginning of the array) to free.
717 : *
718 : * Passing a non-NULL @array and @n == 0 as well as NULL @array are valid
719 : * use-cases. If @array is NULL, the function does nothing.
720 : */
721 0 : void kfree_strarray(char **array, size_t n)
722 : {
723 : unsigned int i;
724 :
725 0 : if (!array)
726 : return;
727 :
728 0 : for (i = 0; i < n; i++)
729 0 : kfree(array[i]);
730 0 : kfree(array);
731 : }
732 : EXPORT_SYMBOL_GPL(kfree_strarray);
733 :
734 : struct strarray {
735 : char **array;
736 : size_t n;
737 : };
738 :
739 0 : static void devm_kfree_strarray(struct device *dev, void *res)
740 : {
741 0 : struct strarray *array = res;
742 :
743 0 : kfree_strarray(array->array, array->n);
744 0 : }
745 :
746 0 : char **devm_kasprintf_strarray(struct device *dev, const char *prefix, size_t n)
747 : {
748 : struct strarray *ptr;
749 :
750 0 : ptr = devres_alloc(devm_kfree_strarray, sizeof(*ptr), GFP_KERNEL);
751 0 : if (!ptr)
752 : return ERR_PTR(-ENOMEM);
753 :
754 0 : ptr->array = kasprintf_strarray(GFP_KERNEL, prefix, n);
755 0 : if (!ptr->array) {
756 0 : devres_free(ptr);
757 0 : return ERR_PTR(-ENOMEM);
758 : }
759 :
760 : return ptr->array;
761 : }
762 : EXPORT_SYMBOL_GPL(devm_kasprintf_strarray);
763 :
764 : /**
765 : * strscpy_pad() - Copy a C-string into a sized buffer
766 : * @dest: Where to copy the string to
767 : * @src: Where to copy the string from
768 : * @count: Size of destination buffer
769 : *
770 : * Copy the string, or as much of it as fits, into the dest buffer. The
771 : * behavior is undefined if the string buffers overlap. The destination
772 : * buffer is always %NUL terminated, unless it's zero-sized.
773 : *
774 : * If the source string is shorter than the destination buffer, zeros
775 : * the tail of the destination buffer.
776 : *
777 : * For full explanation of why you may want to consider using the
778 : * 'strscpy' functions please see the function docstring for strscpy().
779 : *
780 : * Returns:
781 : * * The number of characters copied (not including the trailing %NUL)
782 : * * -E2BIG if count is 0 or @src was truncated.
783 : */
784 106 : ssize_t strscpy_pad(char *dest, const char *src, size_t count)
785 : {
786 : ssize_t written;
787 :
788 106 : written = strscpy(dest, src, count);
789 106 : if (written < 0 || written == count - 1)
790 : return written;
791 :
792 13 : memset(dest + written + 1, 0, count - written - 1);
793 :
794 13 : return written;
795 : }
796 : EXPORT_SYMBOL(strscpy_pad);
797 :
798 : /**
799 : * skip_spaces - Removes leading whitespace from @str.
800 : * @str: The string to be stripped.
801 : *
802 : * Returns a pointer to the first non-whitespace character in @str.
803 : */
804 50 : char *skip_spaces(const char *str)
805 : {
806 100 : while (isspace(*str))
807 0 : ++str;
808 50 : return (char *)str;
809 : }
810 : EXPORT_SYMBOL(skip_spaces);
811 :
812 : /**
813 : * strim - Removes leading and trailing whitespace from @s.
814 : * @s: The string to be stripped.
815 : *
816 : * Note that the first trailing whitespace is replaced with a %NUL-terminator
817 : * in the given string @s. Returns a pointer to the first non-whitespace
818 : * character in @s.
819 : */
820 0 : char *strim(char *s)
821 : {
822 : size_t size;
823 : char *end;
824 :
825 0 : size = strlen(s);
826 0 : if (!size)
827 : return s;
828 :
829 0 : end = s + size - 1;
830 0 : while (end >= s && isspace(*end))
831 0 : end--;
832 0 : *(end + 1) = '\0';
833 :
834 : return skip_spaces(s);
835 : }
836 : EXPORT_SYMBOL(strim);
837 :
838 : /**
839 : * sysfs_streq - return true if strings are equal, modulo trailing newline
840 : * @s1: one string
841 : * @s2: another string
842 : *
843 : * This routine returns true iff two strings are equal, treating both
844 : * NUL and newline-then-NUL as equivalent string terminations. It's
845 : * geared for use with sysfs input strings, which generally terminate
846 : * with newlines but are compared against values without newlines.
847 : */
848 0 : bool sysfs_streq(const char *s1, const char *s2)
849 : {
850 0 : while (*s1 && *s1 == *s2) {
851 0 : s1++;
852 0 : s2++;
853 : }
854 :
855 0 : if (*s1 == *s2)
856 : return true;
857 0 : if (!*s1 && *s2 == '\n' && !s2[1])
858 : return true;
859 0 : if (*s1 == '\n' && !s1[1] && !*s2)
860 : return true;
861 0 : return false;
862 : }
863 : EXPORT_SYMBOL(sysfs_streq);
864 :
865 : /**
866 : * match_string - matches given string in an array
867 : * @array: array of strings
868 : * @n: number of strings in the array or -1 for NULL terminated arrays
869 : * @string: string to match with
870 : *
871 : * This routine will look for a string in an array of strings up to the
872 : * n-th element in the array or until the first NULL element.
873 : *
874 : * Historically the value of -1 for @n, was used to search in arrays that
875 : * are NULL terminated. However, the function does not make a distinction
876 : * when finishing the search: either @n elements have been compared OR
877 : * the first NULL element was found.
878 : *
879 : * Return:
880 : * index of a @string in the @array if matches, or %-EINVAL otherwise.
881 : */
882 0 : int match_string(const char * const *array, size_t n, const char *string)
883 : {
884 : int index;
885 : const char *item;
886 :
887 0 : for (index = 0; index < n; index++) {
888 0 : item = array[index];
889 0 : if (!item)
890 : break;
891 0 : if (!strcmp(item, string))
892 : return index;
893 : }
894 :
895 : return -EINVAL;
896 : }
897 : EXPORT_SYMBOL(match_string);
898 :
899 : /**
900 : * __sysfs_match_string - matches given string in an array
901 : * @array: array of strings
902 : * @n: number of strings in the array or -1 for NULL terminated arrays
903 : * @str: string to match with
904 : *
905 : * Returns index of @str in the @array or -EINVAL, just like match_string().
906 : * Uses sysfs_streq instead of strcmp for matching.
907 : *
908 : * This routine will look for a string in an array of strings up to the
909 : * n-th element in the array or until the first NULL element.
910 : *
911 : * Historically the value of -1 for @n, was used to search in arrays that
912 : * are NULL terminated. However, the function does not make a distinction
913 : * when finishing the search: either @n elements have been compared OR
914 : * the first NULL element was found.
915 : */
916 0 : int __sysfs_match_string(const char * const *array, size_t n, const char *str)
917 : {
918 : const char *item;
919 : int index;
920 :
921 0 : for (index = 0; index < n; index++) {
922 0 : item = array[index];
923 0 : if (!item)
924 : break;
925 0 : if (sysfs_streq(item, str))
926 : return index;
927 : }
928 :
929 : return -EINVAL;
930 : }
931 : EXPORT_SYMBOL(__sysfs_match_string);
932 :
933 : /**
934 : * strreplace - Replace all occurrences of character in string.
935 : * @s: The string to operate on.
936 : * @old: The character being replaced.
937 : * @new: The character @old is replaced with.
938 : *
939 : * Returns pointer to the nul byte at the end of @s.
940 : */
941 0 : char *strreplace(char *s, char old, char new)
942 : {
943 0 : for (; *s; ++s)
944 0 : if (*s == old)
945 0 : *s = new;
946 0 : return s;
947 : }
948 : EXPORT_SYMBOL(strreplace);
949 :
950 : /**
951 : * memcpy_and_pad - Copy one buffer to another with padding
952 : * @dest: Where to copy to
953 : * @dest_len: The destination buffer size
954 : * @src: Where to copy from
955 : * @count: The number of bytes to copy
956 : * @pad: Character to use for padding if space is left in destination.
957 : */
958 0 : void memcpy_and_pad(void *dest, size_t dest_len, const void *src, size_t count,
959 : int pad)
960 : {
961 0 : if (dest_len > count) {
962 0 : memcpy(dest, src, count);
963 0 : memset(dest + count, pad, dest_len - count);
964 : } else {
965 0 : memcpy(dest, src, dest_len);
966 : }
967 0 : }
968 : EXPORT_SYMBOL(memcpy_and_pad);
969 :
970 : #ifdef CONFIG_FORTIFY_SOURCE
971 : /* These are placeholders for fortify compile-time warnings. */
972 : void __read_overflow2_field(size_t avail, size_t wanted) { }
973 : EXPORT_SYMBOL(__read_overflow2_field);
974 : void __write_overflow_field(size_t avail, size_t wanted) { }
975 : EXPORT_SYMBOL(__write_overflow_field);
976 :
977 : void fortify_panic(const char *name)
978 : {
979 : pr_emerg("detected buffer overflow in %s\n", name);
980 : BUG();
981 : }
982 : EXPORT_SYMBOL(fortify_panic);
983 : #endif /* CONFIG_FORTIFY_SOURCE */
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