1 /* $NetBSD: aligned_alloc.c,v 1.3 2024/08/18 18:47:20 riastradh Exp $ */ 2 3 /*- 4 * Copyright (C) 2015 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to The NetBSD Foundation 8 * by Niclas Rosenvik. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice(s), this list of conditions and the following disclaimer as 15 * the first lines of this file unmodified other than the possible 16 * addition of one or more copyright notices. 17 * 2. Redistributions in binary form must reproduce the above copyright 18 * notice(s), this list of conditions and the following disclaimer in 19 * the documentation and/or other materials provided with the 20 * distribution. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDER(S) ``AS IS'' AND ANY 23 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 25 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER(S) BE 26 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 27 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 28 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR 29 * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, 30 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE 31 * OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, 32 * EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 33 */ 34 35 #include <sys/cdefs.h> 36 __RCSID("$NetBSD: aligned_alloc.c,v 1.3 2024/08/18 18:47:20 riastradh Exp $"); 37 38 #include <errno.h> 39 #include <stdlib.h> 40 41 void * 42 aligned_alloc(size_t alignment, size_t size) 43 { 44 void *memptr; 45 int err; 46 47 /* 48 * Check that alignment is a power of 2. 49 */ 50 if (alignment == 0 || ((alignment - 1) & alignment) != 0) { 51 errno = EINVAL; 52 return NULL; 53 } 54 55 /* 56 * Adjust alignment to satisfy posix_memalign, 57 * larger alignments satisfy smaller alignments. 58 */ 59 while (alignment < sizeof(void *)) { 60 alignment <<= 1; 61 } 62 63 err = posix_memalign(&memptr, alignment, size); 64 if (err) { 65 errno = err; 66 return NULL; 67 } 68 69 return memptr; 70 } 71