xref: /freebsd-src/lib/libc/stdlib/reallocarray.c (revision 559a218c9b257775fb249b67945fe4a05b7a6b9f)
1*450dfafbSBaptiste Daroussin /*	$OpenBSD: reallocarray.c,v 1.2 2014/12/08 03:45:00 bcook Exp $	*/
2*450dfafbSBaptiste Daroussin /*
3*450dfafbSBaptiste Daroussin  * Copyright (c) 2008 Otto Moerbeek <otto@drijf.net>
4*450dfafbSBaptiste Daroussin  *
5*450dfafbSBaptiste Daroussin  * Permission to use, copy, modify, and distribute this software for any
6*450dfafbSBaptiste Daroussin  * purpose with or without fee is hereby granted, provided that the above
7*450dfafbSBaptiste Daroussin  * copyright notice and this permission notice appear in all copies.
8*450dfafbSBaptiste Daroussin  *
9*450dfafbSBaptiste Daroussin  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
10*450dfafbSBaptiste Daroussin  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
11*450dfafbSBaptiste Daroussin  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
12*450dfafbSBaptiste Daroussin  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
13*450dfafbSBaptiste Daroussin  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
14*450dfafbSBaptiste Daroussin  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
15*450dfafbSBaptiste Daroussin  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
16*450dfafbSBaptiste Daroussin  */
17*450dfafbSBaptiste Daroussin 
18*450dfafbSBaptiste Daroussin #include <sys/types.h>
19*450dfafbSBaptiste Daroussin #include <errno.h>
20*450dfafbSBaptiste Daroussin #include <stdint.h>
21*450dfafbSBaptiste Daroussin #include <stdlib.h>
22*450dfafbSBaptiste Daroussin 
23*450dfafbSBaptiste Daroussin /*
24*450dfafbSBaptiste Daroussin  * This is sqrt(SIZE_MAX+1), as s1*s2 <= SIZE_MAX
25*450dfafbSBaptiste Daroussin  * if both s1 < MUL_NO_OVERFLOW and s2 < MUL_NO_OVERFLOW
26*450dfafbSBaptiste Daroussin  */
27*450dfafbSBaptiste Daroussin #define MUL_NO_OVERFLOW	((size_t)1 << (sizeof(size_t) * 4))
28*450dfafbSBaptiste Daroussin 
29*450dfafbSBaptiste Daroussin void *
reallocarray(void * optr,size_t nmemb,size_t size)30*450dfafbSBaptiste Daroussin reallocarray(void *optr, size_t nmemb, size_t size)
31*450dfafbSBaptiste Daroussin {
32*450dfafbSBaptiste Daroussin 
33*450dfafbSBaptiste Daroussin 	if ((nmemb >= MUL_NO_OVERFLOW || size >= MUL_NO_OVERFLOW) &&
34*450dfafbSBaptiste Daroussin 	    nmemb > 0 && SIZE_MAX / nmemb < size) {
35*450dfafbSBaptiste Daroussin 		errno = ENOMEM;
36*450dfafbSBaptiste Daroussin 		return (NULL);
37*450dfafbSBaptiste Daroussin 	}
38*450dfafbSBaptiste Daroussin 	return (realloc(optr, size * nmemb));
39*450dfafbSBaptiste Daroussin }
40