[apple/libc.git] / sys / munmap.c

/*
 * Copyright (c) 2004 Apple Computer, Inc. All rights reserved.
 *
 * @APPLE_LICENSE_HEADER_START@
 * 
 * This file contains Original Code and/or Modifications of Original Code
 * as defined in and that are subject to the Apple Public Source License
 * Version 2.0 (the 'License'). You may not use this file except in
 * compliance with the License. Please obtain a copy of the License at
 * http://www.opensource.apple.com/apsl/ and read it before using this
 * file.
 * 
 * The Original Code and all software distributed under the License are
 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
 * Please see the License for the specific language governing rights and
 * limitations under the License.
 * 
 * @APPLE_LICENSE_HEADER_END@
 */
#include <unistd.h>
#include <sys/types.h>
#include <sys/mman.h>

/*
 * Stub function to account for the differences in standard compliance
 * while maintaining binary backward compatibility.
 *
 * This is only the legacy behavior.
 */
extern int __munmap(void *, size_t);

int
munmap(void *addr, size_t len)
{
	int	page_mask;
	size_t	offset;

	if (len == 0) {
		/*
		 * Standard compliance now requires the system to return EINVAL
		 * for munmap(addr, 0).  Return success now to maintain
		 * backwards compatibility.
		 */
		return 0;
	}
	/*
	 * Page-align "addr" since the system now requires it
	 * for standards compliance.
	 * Update "len" to reflect the adjustment and still cover the same area.
	 */
	page_mask = getpagesize() - 1;
	offset = ((uintptr_t) addr) & page_mask;
	addr = (void *) (((uintptr_t) addr) & ~page_mask);
	len += offset;
	return __munmap(addr, len);
}
Commit	Line	Data
3d9156a7 A	1	/*
	2	* Copyright (c) 2004 Apple Computer, Inc. All rights reserved.
	3	*
	4	* @APPLE_LICENSE_HEADER_START@
	5	*
	6	* This file contains Original Code and/or Modifications of Original Code
	7	* as defined in and that are subject to the Apple Public Source License
	8	* Version 2.0 (the 'License'). You may not use this file except in
	9	* compliance with the License. Please obtain a copy of the License at
	10	* http://www.opensource.apple.com/apsl/ and read it before using this
	11	* file.
	12	*
	13	* The Original Code and all software distributed under the License are
	14	* distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
	15	* EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
	16	* INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
	17	* FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
	18	* Please see the License for the specific language governing rights and
	19	* limitations under the License.
	20	*
	21	* @APPLE_LICENSE_HEADER_END@
	22	*/
	23	#include <unistd.h>
	24	#include <sys/types.h>
	25	#include <sys/mman.h>
3d9156a7 A	26
	27	/*
	28	* Stub function to account for the differences in standard compliance
	29	* while maintaining binary backward compatibility.
224c7076 A	30	*
224c7076 A	31	* This is only the legacy behavior.
3d9156a7	32	*/
224c7076 A	33	extern int __munmap(void *, size_t);
224c7076 A	34
3d9156a7 A	35	int
	36	munmap(void *addr, size_t len)
	37	{
3d9156a7 A	38	int page_mask;
3d9156a7 A	39	size_t offset;
3d9156a7 A	40
	41	if (len == 0) {
	42	/*
	43	* Standard compliance now requires the system to return EINVAL
	44	* for munmap(addr, 0). Return success now to maintain
	45	* backwards compatibility.
	46	*/
	47	return 0;
	48	}
	49	/*
	50	* Page-align "addr" since the system now requires it
	51	* for standards compliance.
	52	* Update "len" to reflect the adjustment and still cover the same area.
	53	*/
	54	page_mask = getpagesize() - 1;
	55	offset = ((uintptr_t) addr) & page_mask;
	56	addr = (void *) (((uintptr_t) addr) & ~page_mask);
	57	len += offset;
224c7076	58	return __munmap(addr, len);
3d9156a7	59	}