xref: /illumos-gate/usr/src/lib/libc/port/gen/posix_memalign.c (revision 07a48826732249fcd3aa8dd53c8389595e9f1fbc)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 
22 /*
23  * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 #pragma ident	"%Z%%M%	%I%	%E% SMI"
28 
29 #include "lint.h"
30 #include <stdlib.h>
31 #include <errno.h>
32 
33 /*
34  * SUSv3 - aligned memory allocation
35  *
36  * From the SUSv3 specification:
37  *    The value of alignment shall be a power
38  *    of two multiple of sizeof (void *).
39  * This is enforced below.
40  *
41  * From the SUSv3 specification:
42  *    If the size of the space requested is 0, the behavior
43  *    is implementation-defined; the value returned in memptr
44  *    shall be either a null pointer or a unique pointer.
45  * We choose always to return a null pointer in this case.
46  * (Not all implementations of memalign() behave this way.)
47  */
48 int
49 posix_memalign(void **memptr, size_t alignment, size_t size)
50 {
51 	void *ptr = NULL;
52 	int error = 0;
53 
54 	if (alignment == 0 ||
55 	    (alignment & (sizeof (void *) - 1)) != 0 ||
56 	    (alignment & (alignment - 1)) != 0)
57 		error = EINVAL;
58 	else if (size != 0 &&
59 	    (ptr = memalign(alignment, size)) == NULL)
60 		error = ENOMEM;
61 
62 	*memptr = ptr;
63 	return (error);
64 }
65