1 babf5d5a 2021-05-11 martijn /*	$OpenBSD: reallocarray.c,v 1.1 2014/05/08 21:43:49 deraadt Exp $	*/
 2 babf5d5a 2021-05-11 martijn /*
 3 babf5d5a 2021-05-11 martijn  * Copyright (c) 2008 Otto Moerbeek <otto@drijf.net>
 4 babf5d5a 2021-05-11 martijn  *
 5 babf5d5a 2021-05-11 martijn  * Permission to use, copy, modify, and distribute this software for any
 6 babf5d5a 2021-05-11 martijn  * purpose with or without fee is hereby granted, provided that the above
 7 babf5d5a 2021-05-11 martijn  * copyright notice and this permission notice appear in all copies.
 8 babf5d5a 2021-05-11 martijn  *
 9 babf5d5a 2021-05-11 martijn  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
10 babf5d5a 2021-05-11 martijn  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
11 babf5d5a 2021-05-11 martijn  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
12 babf5d5a 2021-05-11 martijn  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
13 babf5d5a 2021-05-11 martijn  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
14 babf5d5a 2021-05-11 martijn  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
15 babf5d5a 2021-05-11 martijn  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
16 babf5d5a 2021-05-11 martijn  */
17 babf5d5a 2021-05-11 martijn 
18 babf5d5a 2021-05-11 martijn /* OPENBSD ORIGINAL: lib/libc/stdlib/reallocarray.c */
19 babf5d5a 2021-05-11 martijn 
20 babf5d5a 2021-05-11 martijn #include "openbsd-compat.h"
21 babf5d5a 2021-05-11 martijn 
22 babf5d5a 2021-05-11 martijn #include <sys/types.h>
23 babf5d5a 2021-05-11 martijn #include <errno.h>
24 babf5d5a 2021-05-11 martijn #include <stdint.h>
25 babf5d5a 2021-05-11 martijn #include <stdlib.h>
26 babf5d5a 2021-05-11 martijn 
27 babf5d5a 2021-05-11 martijn /*
28 babf5d5a 2021-05-11 martijn  * This is sqrt(SIZE_MAX+1), as s1*s2 <= SIZE_MAX
29 babf5d5a 2021-05-11 martijn  * if both s1 < MUL_NO_OVERFLOW and s2 < MUL_NO_OVERFLOW
30 babf5d5a 2021-05-11 martijn  */
31 babf5d5a 2021-05-11 martijn #define MUL_NO_OVERFLOW	(1UL << (sizeof(size_t) * 4))
32 babf5d5a 2021-05-11 martijn 
33 babf5d5a 2021-05-11 martijn void *
34 babf5d5a 2021-05-11 martijn reallocarray(void *optr, size_t nmemb, size_t size)
35 babf5d5a 2021-05-11 martijn {
36 babf5d5a 2021-05-11 martijn 	if ((nmemb >= MUL_NO_OVERFLOW || size >= MUL_NO_OVERFLOW) &&
37 babf5d5a 2021-05-11 martijn 	    nmemb > 0 && SIZE_MAX / nmemb < size) {
38 babf5d5a 2021-05-11 martijn 		errno = ENOMEM;
39 babf5d5a 2021-05-11 martijn 		return NULL;
40 babf5d5a 2021-05-11 martijn 	}
41 babf5d5a 2021-05-11 martijn 	return realloc(optr, size * nmemb);
42 babf5d5a 2021-05-11 martijn }