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/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License, Version 1.0 only
* (the "License"). You may not use this file except in compliance
* with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or http://www.opensolaris.org/os/licensing.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/*
* Copyright 2004 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms.
*/
/*
* Miscellaneous C routines for copying data around without
* descending into assembler. Compilers are pretty good at
* scheduling instructions, and humans are pretty hopeless at
* writing correct assembler.
*/
#include <sys/types.h>
#include <sys/systm.h>
#include <sys/errno.h>
#include <sys/param.h>
/*
* copyinstr_noerr and copyoutstr_noerr can be implemented completely
* in C on machines with shared user and kernel context.
*/
static int
copystr_nofault(const char *src, char *dst, size_t maxlength,
size_t *lencopied)
{
int error = 0;
size_t leftover;
if ((leftover = maxlength) == 0)
error = ENAMETOOLONG;
else
do {
leftover--;
if ((*dst++ = *src++) == '\0')
break;
if (leftover == 0) {
error = ENAMETOOLONG;
break;
}
/*CONSTCOND*/
} while (1);
if (lencopied)
*lencopied = maxlength - leftover;
return (error);
}
int
copyinstr_noerr(const char *uaddr, char *kaddr, size_t maxlength,
size_t *lencopied)
{
char *ua = (char *)uaddr;
ASSERT((uintptr_t)kaddr > kernelbase);
if ((uintptr_t)ua > kernelbase) {
/*
* force fault at kernelbase
*/
ua = (char *)kernelbase;
}
return (copystr_nofault(ua, kaddr, maxlength, lencopied));
}
int
copyoutstr_noerr(const char *kaddr, char *uaddr, size_t maxlength,
size_t *lencopied)
{
char *ua = (char *)uaddr;
ASSERT((uintptr_t)kaddr > kernelbase);
if ((uintptr_t)ua > kernelbase) {
/*
* force fault at kernelbase
*/
ua = (char *)kernelbase;
}
return (copystr_nofault(kaddr, ua, maxlength, lencopied));
}
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