1 2dfdd11a 2022-10-13 op /*	$OpenBSD: reallocarray.c,v 1.3 2015/09/13 08:31:47 guenther Exp $	*/
 2 2dfdd11a 2022-10-13 op /*
 3 2dfdd11a 2022-10-13 op  * Copyright (c) 2008 Otto Moerbeek <otto@drijf.net>
 4 2dfdd11a 2022-10-13 op  *
 5 2dfdd11a 2022-10-13 op  * Permission to use, copy, modify, and distribute this software for any
 6 2dfdd11a 2022-10-13 op  * purpose with or without fee is hereby granted, provided that the above
 7 2dfdd11a 2022-10-13 op  * copyright notice and this permission notice appear in all copies.
 8 2dfdd11a 2022-10-13 op  *
 9 2dfdd11a 2022-10-13 op  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
10 2dfdd11a 2022-10-13 op  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
11 2dfdd11a 2022-10-13 op  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
12 2dfdd11a 2022-10-13 op  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
13 2dfdd11a 2022-10-13 op  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
14 2dfdd11a 2022-10-13 op  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
15 2dfdd11a 2022-10-13 op  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
16 2dfdd11a 2022-10-13 op  */
17 2dfdd11a 2022-10-13 op 
18 2dfdd11a 2022-10-13 op #include "compat.h"
19 2dfdd11a 2022-10-13 op 
20 2dfdd11a 2022-10-13 op #include <sys/types.h>
21 2dfdd11a 2022-10-13 op #include <errno.h>
22 2dfdd11a 2022-10-13 op #include <stdint.h>
23 2dfdd11a 2022-10-13 op #include <stdlib.h>
24 2dfdd11a 2022-10-13 op 
25 2dfdd11a 2022-10-13 op /*
26 2dfdd11a 2022-10-13 op  * This is sqrt(SIZE_MAX+1), as s1*s2 <= SIZE_MAX
27 2dfdd11a 2022-10-13 op  * if both s1 < MUL_NO_OVERFLOW and s2 < MUL_NO_OVERFLOW
28 2dfdd11a 2022-10-13 op  */
29 2dfdd11a 2022-10-13 op #define MUL_NO_OVERFLOW	((size_t)1 << (sizeof(size_t) * 4))
30 2dfdd11a 2022-10-13 op 
31 2dfdd11a 2022-10-13 op void *
32 2dfdd11a 2022-10-13 op reallocarray(void *optr, size_t nmemb, size_t size)
33 2dfdd11a 2022-10-13 op {
34 2dfdd11a 2022-10-13 op 	if ((nmemb >= MUL_NO_OVERFLOW || size >= MUL_NO_OVERFLOW) &&
35 2dfdd11a 2022-10-13 op 	    nmemb > 0 && SIZE_MAX / nmemb < size) {
36 2dfdd11a 2022-10-13 op 		errno = ENOMEM;
37 2dfdd11a 2022-10-13 op 		return NULL;
38 2dfdd11a 2022-10-13 op 	}
39 2dfdd11a 2022-10-13 op 	return realloc(optr, size * nmemb);
40 2dfdd11a 2022-10-13 op }