xref: /netbsd-src/lib/libc/stdlib/reallocarr.c (revision f1354ae7ef5fcca5cce5ed58e31717e689c00d2a)
1 /* $NetBSD: reallocarr.c,v 1.2 2015/07/16 00:03:59 kamil Exp $ */
2 
3 /*-
4  * Copyright (c) 2015 Joerg Sonnenberger <joerg@NetBSD.org>.
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  *
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in
15  *    the documentation and/or other materials provided with the
16  *    distribution.
17  *
18  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
19  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
20  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
21  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
22  * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
23  * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
24  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
25  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
26  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
27  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
28  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  */
31 
32 #include <sys/cdefs.h>
33 __RCSID("$NetBSD: reallocarr.c,v 1.2 2015/07/16 00:03:59 kamil Exp $");
34 
35 #include "namespace.h"
36 #include <errno.h>
37 /* Old POSIX has SIZE_MAX in limits.h */
38 #include <limits.h>
39 #include <stdint.h>
40 #include <stdlib.h>
41 #include <string.h>
42 
43 __CTASSERT(65535 < SIZE_MAX / 65535);
44 
45 #ifdef _LIBC
46 #ifdef __weak_alias
47 __weak_alias(reallocarr, _reallocarr)
48 #endif
49 #endif
50 
51 int
52 reallocarr(void *ptr, size_t num, size_t size)
53 {
54 	int saved_errno, result;
55 	void *optr;
56 	void *nptr;
57 
58 	saved_errno = errno;
59 	memcpy(&optr, ptr, sizeof(ptr));
60 	if (num == 0 || size == 0) {
61 		free(optr);
62 		nptr = NULL;
63 		memcpy(ptr, &nptr, sizeof(ptr));
64 		errno = saved_errno;
65 		return 0;
66 	}
67 	if ((num >= 65535 || size >= 65535) && num > SIZE_MAX / size)
68 		return EOVERFLOW;
69 	nptr = realloc(optr, num * size);
70 	if (nptr == NULL) {
71 		result = errno;
72 	} else {
73 		result = 0;
74 		memcpy(ptr, &nptr, sizeof(ptr));
75 	}
76 	errno = saved_errno;
77 	return result;
78 }
79