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Darren Tucker642652d2014-12-10 01:32:23 +11001/* $OpenBSD: reallocarray.c,v 1.1 2014/05/08 21:43:49 deraadt Exp $ */
2/*
3 * Copyright (c) 2008 Otto Moerbeek <otto@drijf.net>
4 *
5 * Permission to use, copy, modify, and distribute this software for any
6 * purpose with or without fee is hereby granted, provided that the above
7 * copyright notice and this permission notice appear in all copies.
8 *
9 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
10 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
11 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
12 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
13 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
14 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
15 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
16 */
17
18/* OPENBSD ORIGINAL: lib/libc/stdlib/reallocarray.c */
19
20#include "includes.h"
21#ifndef HAVE_REALLOCARRAY
22
23#include <sys/types.h>
24#include <errno.h>
25#include <stdint.h>
26#include <stdlib.h>
27
28/*
29 * This is sqrt(SIZE_MAX+1), as s1*s2 <= SIZE_MAX
30 * if both s1 < MUL_NO_OVERFLOW and s2 < MUL_NO_OVERFLOW
31 */
32#define MUL_NO_OVERFLOW (1UL << (sizeof(size_t) * 4))
33
34void *
35reallocarray(void *optr, size_t nmemb, size_t size)
36{
37 if ((nmemb >= MUL_NO_OVERFLOW || size >= MUL_NO_OVERFLOW) &&
38 nmemb > 0 && SIZE_MAX / nmemb < size) {
39 errno = ENOMEM;
40 return NULL;
41 }
42 return realloc(optr, size * nmemb);
43}
44#endif /* HAVE_REALLOCARRAY */