1 /*
2 * Copyright (c) 2008 Otto Moerbeek <otto@drijf.net>
3 *
4 * Permission to use, copy, modify, and distribute this software for any
5 * purpose with or without fee is hereby granted, provided that the above
6 * copyright notice and this permission notice appear in all copies.
7 *
8 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
9 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
10 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
11 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
12 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
13 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
14 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
15 */
16
17 #include <sys/types.h>
18 #include <errno.h>
19 #include <stdint.h>
20 #include <stdlib.h>
21
22 /*
23 * This is sqrt(SIZE_MAX+1), as s1*s2 <= SIZE_MAX
24 * if both s1 < MUL_NO_OVERFLOW and s2 < MUL_NO_OVERFLOW
25 */
26 #define MUL_NO_OVERFLOW ((size_t)1 << (sizeof (size_t) * 4))
27
28 void *
reallocarray(void * ptr,size_t nelem,size_t elsize)29 reallocarray(void *ptr, size_t nelem, size_t elsize)
30 {
31 if ((nelem >= MUL_NO_OVERFLOW || elsize >= MUL_NO_OVERFLOW) &&
32 nelem > 0 && SIZE_MAX / nelem < elsize) {
33 errno = ENOMEM;
34 return (NULL);
35 }
36 return (realloc(ptr, elsize * nelem));
37 }
38