xref: /freebsd-13.1/lib/libc/stdlib/reallocarray.c (revision 450dfafb)
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 <[email protected]>
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/cdefs.h>
19*450dfafbSBaptiste Daroussin __FBSDID("$FreeBSD$");
20*450dfafbSBaptiste Daroussin 
21*450dfafbSBaptiste Daroussin #include <sys/types.h>
22*450dfafbSBaptiste Daroussin #include <errno.h>
23*450dfafbSBaptiste Daroussin #include <stdint.h>
24*450dfafbSBaptiste Daroussin #include <stdlib.h>
25*450dfafbSBaptiste Daroussin 
26*450dfafbSBaptiste Daroussin /*
27*450dfafbSBaptiste Daroussin  * This is sqrt(SIZE_MAX+1), as s1*s2 <= SIZE_MAX
28*450dfafbSBaptiste Daroussin  * if both s1 < MUL_NO_OVERFLOW and s2 < MUL_NO_OVERFLOW
29*450dfafbSBaptiste Daroussin  */
30*450dfafbSBaptiste Daroussin #define MUL_NO_OVERFLOW	((size_t)1 << (sizeof(size_t) * 4))
31*450dfafbSBaptiste Daroussin 
32*450dfafbSBaptiste Daroussin void *
reallocarray(void * optr,size_t nmemb,size_t size)33*450dfafbSBaptiste Daroussin reallocarray(void *optr, size_t nmemb, size_t size)
34*450dfafbSBaptiste Daroussin {
35*450dfafbSBaptiste Daroussin 
36*450dfafbSBaptiste Daroussin 	if ((nmemb >= MUL_NO_OVERFLOW || size >= MUL_NO_OVERFLOW) &&
37*450dfafbSBaptiste Daroussin 	    nmemb > 0 && SIZE_MAX / nmemb < size) {
38*450dfafbSBaptiste Daroussin 		errno = ENOMEM;
39*450dfafbSBaptiste Daroussin 		return (NULL);
40*450dfafbSBaptiste Daroussin 	}
41*450dfafbSBaptiste Daroussin 	return (realloc(optr, size * nmemb));
42*450dfafbSBaptiste Daroussin }
43