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1 8951cb19 2022-07-01 op /*
2 8951cb19 2022-07-01 op * Copyright (c) 2008, 2017 Otto Moerbeek <otto@drijf.net>
3 8951cb19 2022-07-01 op *
4 8951cb19 2022-07-01 op * Permission to use, copy, modify, and distribute this software for any
5 8951cb19 2022-07-01 op * purpose with or without fee is hereby granted, provided that the above
6 8951cb19 2022-07-01 op * copyright notice and this permission notice appear in all copies.
7 8951cb19 2022-07-01 op *
8 8951cb19 2022-07-01 op * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
9 8951cb19 2022-07-01 op * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
10 8951cb19 2022-07-01 op * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
11 8951cb19 2022-07-01 op * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
12 8951cb19 2022-07-01 op * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
13 8951cb19 2022-07-01 op * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
14 8951cb19 2022-07-01 op * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
15 8951cb19 2022-07-01 op */
16 8951cb19 2022-07-01 op
17 8951cb19 2022-07-01 op /* OPENBSD ORIGINAL: lib/libc/stdlib/recallocarray.c */
18 8951cb19 2022-07-01 op
19 f164f2f4 2022-07-01 op #include "config.h"
20 f164f2f4 2022-07-01 op
21 8951cb19 2022-07-01 op #include <errno.h>
22 8951cb19 2022-07-01 op #include <stdlib.h>
23 8951cb19 2022-07-01 op #include <stdint.h>
24 8951cb19 2022-07-01 op #include <string.h>
25 8951cb19 2022-07-01 op #include <unistd.h>
26 8951cb19 2022-07-01 op
27 8951cb19 2022-07-01 op /*
28 8951cb19 2022-07-01 op * This is sqrt(SIZE_MAX+1), as s1*s2 <= SIZE_MAX
29 8951cb19 2022-07-01 op * if both s1 < MUL_NO_OVERFLOW and s2 < MUL_NO_OVERFLOW
30 8951cb19 2022-07-01 op */
31 8951cb19 2022-07-01 op #define MUL_NO_OVERFLOW ((size_t)1 << (sizeof(size_t) * 4))
32 8951cb19 2022-07-01 op
33 8951cb19 2022-07-01 op void *
34 8951cb19 2022-07-01 op recallocarray(void *ptr, size_t oldnmemb, size_t newnmemb, size_t size)
35 8951cb19 2022-07-01 op {
36 8951cb19 2022-07-01 op size_t oldsize, newsize;
37 8951cb19 2022-07-01 op void *newptr;
38 8951cb19 2022-07-01 op
39 8951cb19 2022-07-01 op if (ptr == NULL)
40 8951cb19 2022-07-01 op return calloc(newnmemb, size);
41 8951cb19 2022-07-01 op
42 8951cb19 2022-07-01 op if ((newnmemb >= MUL_NO_OVERFLOW || size >= MUL_NO_OVERFLOW) &&
43 8951cb19 2022-07-01 op newnmemb > 0 && SIZE_MAX / newnmemb < size) {
44 8951cb19 2022-07-01 op errno = ENOMEM;
45 8951cb19 2022-07-01 op return NULL;
46 8951cb19 2022-07-01 op }
47 8951cb19 2022-07-01 op newsize = newnmemb * size;
48 8951cb19 2022-07-01 op
49 8951cb19 2022-07-01 op if ((oldnmemb >= MUL_NO_OVERFLOW || size >= MUL_NO_OVERFLOW) &&
50 8951cb19 2022-07-01 op oldnmemb > 0 && SIZE_MAX / oldnmemb < size) {
51 8951cb19 2022-07-01 op errno = EINVAL;
52 8951cb19 2022-07-01 op return NULL;
53 8951cb19 2022-07-01 op }
54 8951cb19 2022-07-01 op oldsize = oldnmemb * size;
55 8951cb19 2022-07-01 op
56 8951cb19 2022-07-01 op /*
57 8951cb19 2022-07-01 op * Don't bother too much if we're shrinking just a bit,
58 8951cb19 2022-07-01 op * we do not shrink for series of small steps, oh well.
59 8951cb19 2022-07-01 op */
60 8951cb19 2022-07-01 op if (newsize <= oldsize) {
61 8951cb19 2022-07-01 op size_t d = oldsize - newsize;
62 8951cb19 2022-07-01 op
63 8951cb19 2022-07-01 op if (d < oldsize / 2 && d < (size_t)getpagesize()) {
64 8951cb19 2022-07-01 op memset((char *)ptr + newsize, 0, d);
65 8951cb19 2022-07-01 op return ptr;
66 8951cb19 2022-07-01 op }
67 8951cb19 2022-07-01 op }
68 8951cb19 2022-07-01 op
69 8951cb19 2022-07-01 op newptr = malloc(newsize);
70 8951cb19 2022-07-01 op if (newptr == NULL)
71 8951cb19 2022-07-01 op return NULL;
72 8951cb19 2022-07-01 op
73 8951cb19 2022-07-01 op if (newsize > oldsize) {
74 8951cb19 2022-07-01 op memcpy(newptr, ptr, oldsize);
75 8951cb19 2022-07-01 op memset((char *)newptr + oldsize, 0, newsize - oldsize);
76 8951cb19 2022-07-01 op } else
77 8951cb19 2022-07-01 op memcpy(newptr, ptr, newsize);
78 8951cb19 2022-07-01 op
79 8951cb19 2022-07-01 op explicit_bzero(ptr, oldsize);
80 8951cb19 2022-07-01 op free(ptr);
81 8951cb19 2022-07-01 op
82 8951cb19 2022-07-01 op return newptr;
83 8951cb19 2022-07-01 op }