2 5c342d05 2021-01-21 op * Copyright (c) 2008, 2017 Otto Moerbeek <otto@drijf.net>
4 5c342d05 2021-01-21 op * Permission to use, copy, modify, and distribute this software for any
5 5c342d05 2021-01-21 op * purpose with or without fee is hereby granted, provided that the above
6 5c342d05 2021-01-21 op * copyright notice and this permission notice appear in all copies.
8 5c342d05 2021-01-21 op * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
9 5c342d05 2021-01-21 op * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
10 5c342d05 2021-01-21 op * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
11 5c342d05 2021-01-21 op * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
12 5c342d05 2021-01-21 op * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
13 5c342d05 2021-01-21 op * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
14 5c342d05 2021-01-21 op * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
17 76898714 2021-02-12 op #include "../config.h"
19 5c342d05 2021-01-21 op #include <errno.h>
20 5c342d05 2021-01-21 op #include <stdlib.h>
21 5c342d05 2021-01-21 op #include <stdint.h>
22 5c342d05 2021-01-21 op #include <string.h>
23 5c342d05 2021-01-21 op #include <unistd.h>
26 5c342d05 2021-01-21 op * This is sqrt(SIZE_MAX+1), as s1*s2 <= SIZE_MAX
27 5c342d05 2021-01-21 op * if both s1 < MUL_NO_OVERFLOW and s2 < MUL_NO_OVERFLOW
29 5c342d05 2021-01-21 op #define MUL_NO_OVERFLOW ((size_t)1 << (sizeof(size_t) * 4))
32 5c342d05 2021-01-21 op * Even though specified in POSIX, the PAGESIZE and PAGE_SIZE
33 5c342d05 2021-01-21 op * macros have very poor portability. Since we only use this
34 5c342d05 2021-01-21 op * to avoid free() overhead for small shrinking, simply pick
35 5c342d05 2021-01-21 op * an arbitrary number.
37 5c342d05 2021-01-21 op #define getpagesize() (1UL << 12)
40 5c342d05 2021-01-21 op recallocarray(void *ptr, size_t oldnmemb, size_t newnmemb, size_t size)
42 5c342d05 2021-01-21 op size_t oldsize, newsize;
45 5c342d05 2021-01-21 op if (ptr == NULL)
46 5c342d05 2021-01-21 op return calloc(newnmemb, size);
48 5c342d05 2021-01-21 op if ((newnmemb >= MUL_NO_OVERFLOW || size >= MUL_NO_OVERFLOW) &&
49 5c342d05 2021-01-21 op newnmemb > 0 && SIZE_MAX / newnmemb < size) {
50 5c342d05 2021-01-21 op errno = ENOMEM;
53 5c342d05 2021-01-21 op newsize = newnmemb * size;
55 5c342d05 2021-01-21 op if ((oldnmemb >= MUL_NO_OVERFLOW || size >= MUL_NO_OVERFLOW) &&
56 5c342d05 2021-01-21 op oldnmemb > 0 && SIZE_MAX / oldnmemb < size) {
57 5c342d05 2021-01-21 op errno = EINVAL;
60 5c342d05 2021-01-21 op oldsize = oldnmemb * size;
63 5c342d05 2021-01-21 op * Don't bother too much if we're shrinking just a bit,
64 5c342d05 2021-01-21 op * we do not shrink for series of small steps, oh well.
66 5c342d05 2021-01-21 op if (newsize <= oldsize) {
67 5c342d05 2021-01-21 op size_t d = oldsize - newsize;
69 5c342d05 2021-01-21 op if (d < oldsize / 2 && d < getpagesize()) {
70 5c342d05 2021-01-21 op memset((char *)ptr + newsize, 0, d);
75 5c342d05 2021-01-21 op newptr = malloc(newsize);
76 5c342d05 2021-01-21 op if (newptr == NULL)
79 5c342d05 2021-01-21 op if (newsize > oldsize) {
80 5c342d05 2021-01-21 op memcpy(newptr, ptr, oldsize);
81 5c342d05 2021-01-21 op memset((char *)newptr + oldsize, 0, newsize - oldsize);
83 5c342d05 2021-01-21 op memcpy(newptr, ptr, newsize);
85 5c342d05 2021-01-21 op explicit_bzero(ptr, oldsize);
88 5c342d05 2021-01-21 op return newptr;