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 #include "lint.h"
  28 
  29 #include <sys/sysmacros.h>
  30 
  31 #include <stdlib.h>
  32 #include <errno.h>
  33 
  34 /*
  35  * SUSv3 - aligned memory allocation
  36  *
  37  * From the SUSv3 specification:
  38  *    The value of alignment shall be a power
  39  *    of two multiple of sizeof (void *).
  40  * This is enforced below.
  41  *
  42  * From the SUSv3 specification:
  43  *    If the size of the space requested is 0, the behavior
  44  *    is implementation-defined; the value returned in memptr
  45  *    shall be either a null pointer or a unique pointer.
  46  * We choose always to return a null pointer in this case.
  47  * (Not all implementations of memalign() behave this way.)
  48  */
  49 int
  50 posix_memalign(void **memptr, size_t alignment, size_t size)
  51 {
  52         void *ptr = NULL;
  53 
  54         if ((alignment == 0) || !ISP2(alignment) ||
  55             (alignment & (sizeof (void *) - 1)) != 0) {
  56                 return (EINVAL);
  57         } else if (size == 0) {
  58                 *memptr = NULL;
  59                 return (0);
  60         } else {
  61                 if ((ptr = memalign(alignment, size)) == NULL) {
  62                         return (ENOMEM);
  63                 } else {
  64                         *memptr = ptr;
  65                         return (0);
  66                 }
  67         }
  68 }