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/*-
* SPDX-License-Identifier: BSD-2-Clause
*
* Copyright (c) 2009 Alan L. Cox <alc@cs.rice.edu>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <sys/param.h>
#include <sys/mman.h>
#include <sys/sysctl.h>
#include <errno.h>
#include <link.h>
#include "libc_private.h"
/*
* Retrieves page size information from the system. Specifically, returns the
* number of distinct page sizes that are supported by the system, if
* "pagesize" is NULL and "nelem" is 0. Otherwise, assigns up to "nelem" of
* the system-supported page sizes to consecutive elements of the array
* referenced by "pagesize", and returns the number of such page sizes that it
* assigned to the array. These page sizes are expressed in bytes.
*
* The implementation of this function does not directly or indirectly call
* malloc(3) or any other dynamic memory allocator that may itself call this
* function.
*/
int
getpagesizes(size_t pagesize[], int nelem)
{
static u_long ps[MAXPAGESIZES];
static int nops;
size_t size;
int error, i;
if (nelem < 0 || (nelem > 0 && pagesize == NULL)) {
errno = EINVAL;
return (-1);
}
/* Cache the result of the sysctl(2). */
if (nops == 0) {
error = _elf_aux_info(AT_PAGESIZES, ps, sizeof(ps));
size = sizeof(ps);
if (error != 0 || ps[0] == 0) {
if (sysctlbyname("hw.pagesizes", ps, &size, NULL, 0)
== -1)
return (-1);
}
/* Count the number of page sizes that are supported. */
nops = size / sizeof(ps[0]);
while (nops > 0 && ps[nops - 1] == 0)
nops--;
}
if (pagesize == NULL)
return (nops);
/* Return up to "nelem" page sizes from the cached result. */
if (nelem > nops)
nelem = nops;
for (i = 0; i < nelem; i++)
pagesize[i] = ps[i];
return (nelem);
}
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