xref: /onnv-gate/usr/src/uts/intel/ia32/os/copy_subr.c (revision 0:68f95e015346)
1*0Sstevel@tonic-gate /*
2*0Sstevel@tonic-gate  * CDDL HEADER START
3*0Sstevel@tonic-gate  *
4*0Sstevel@tonic-gate  * The contents of this file are subject to the terms of the
5*0Sstevel@tonic-gate  * Common Development and Distribution License, Version 1.0 only
6*0Sstevel@tonic-gate  * (the "License").  You may not use this file except in compliance
7*0Sstevel@tonic-gate  * with the License.
8*0Sstevel@tonic-gate  *
9*0Sstevel@tonic-gate  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10*0Sstevel@tonic-gate  * or http://www.opensolaris.org/os/licensing.
11*0Sstevel@tonic-gate  * See the License for the specific language governing permissions
12*0Sstevel@tonic-gate  * and limitations under the License.
13*0Sstevel@tonic-gate  *
14*0Sstevel@tonic-gate  * When distributing Covered Code, include this CDDL HEADER in each
15*0Sstevel@tonic-gate  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16*0Sstevel@tonic-gate  * If applicable, add the following below this CDDL HEADER, with the
17*0Sstevel@tonic-gate  * fields enclosed by brackets "[]" replaced with your own identifying
18*0Sstevel@tonic-gate  * information: Portions Copyright [yyyy] [name of copyright owner]
19*0Sstevel@tonic-gate  *
20*0Sstevel@tonic-gate  * CDDL HEADER END
21*0Sstevel@tonic-gate  */
22*0Sstevel@tonic-gate /*
23*0Sstevel@tonic-gate  * Copyright 2004 Sun Microsystems, Inc.  All rights reserved.
24*0Sstevel@tonic-gate  * Use is subject to license terms.
25*0Sstevel@tonic-gate  */
26*0Sstevel@tonic-gate 
27*0Sstevel@tonic-gate #pragma ident	"%Z%%M%	%I%	%E% SMI"
28*0Sstevel@tonic-gate 
29*0Sstevel@tonic-gate /*
30*0Sstevel@tonic-gate  * Miscellaneous C routines for copying data around without
31*0Sstevel@tonic-gate  * descending into assembler.  Compilers are pretty good at
32*0Sstevel@tonic-gate  * scheduling instructions, and humans are pretty hopeless at
33*0Sstevel@tonic-gate  * writing correct assembler.
34*0Sstevel@tonic-gate  */
35*0Sstevel@tonic-gate 
36*0Sstevel@tonic-gate #include <sys/types.h>
37*0Sstevel@tonic-gate #include <sys/systm.h>
38*0Sstevel@tonic-gate #include <sys/errno.h>
39*0Sstevel@tonic-gate #include <sys/param.h>
40*0Sstevel@tonic-gate 
41*0Sstevel@tonic-gate /*
42*0Sstevel@tonic-gate  * copyinstr_noerr and copyoutstr_noerr can be implemented completely
43*0Sstevel@tonic-gate  * in C on machines with shared user and kernel context.
44*0Sstevel@tonic-gate  */
45*0Sstevel@tonic-gate static int
copystr_nofault(const char * src,char * dst,size_t maxlength,size_t * lencopied)46*0Sstevel@tonic-gate copystr_nofault(const char *src, char *dst, size_t maxlength,
47*0Sstevel@tonic-gate     size_t *lencopied)
48*0Sstevel@tonic-gate {
49*0Sstevel@tonic-gate 	int error = 0;
50*0Sstevel@tonic-gate 	size_t leftover;
51*0Sstevel@tonic-gate 
52*0Sstevel@tonic-gate 	if ((leftover = maxlength) == 0)
53*0Sstevel@tonic-gate 		error = ENAMETOOLONG;
54*0Sstevel@tonic-gate 	else
55*0Sstevel@tonic-gate 		do {
56*0Sstevel@tonic-gate 			leftover--;
57*0Sstevel@tonic-gate 			if ((*dst++ = *src++) == '\0')
58*0Sstevel@tonic-gate 				break;
59*0Sstevel@tonic-gate 			if (leftover == 0) {
60*0Sstevel@tonic-gate 				error = ENAMETOOLONG;
61*0Sstevel@tonic-gate 				break;
62*0Sstevel@tonic-gate 			}
63*0Sstevel@tonic-gate 		/*CONSTCOND*/
64*0Sstevel@tonic-gate 		} while (1);
65*0Sstevel@tonic-gate 
66*0Sstevel@tonic-gate 	if (lencopied)
67*0Sstevel@tonic-gate 		*lencopied = maxlength - leftover;
68*0Sstevel@tonic-gate 	return (error);
69*0Sstevel@tonic-gate }
70*0Sstevel@tonic-gate 
71*0Sstevel@tonic-gate 
72*0Sstevel@tonic-gate int
copyinstr_noerr(const char * uaddr,char * kaddr,size_t maxlength,size_t * lencopied)73*0Sstevel@tonic-gate copyinstr_noerr(const char *uaddr, char *kaddr, size_t maxlength,
74*0Sstevel@tonic-gate     size_t *lencopied)
75*0Sstevel@tonic-gate {
76*0Sstevel@tonic-gate 	char *ua = (char *)uaddr;
77*0Sstevel@tonic-gate 
78*0Sstevel@tonic-gate 	ASSERT((uintptr_t)kaddr > kernelbase);
79*0Sstevel@tonic-gate 
80*0Sstevel@tonic-gate 	if ((uintptr_t)ua > kernelbase) {
81*0Sstevel@tonic-gate 		/*
82*0Sstevel@tonic-gate 		 * force fault at kernelbase
83*0Sstevel@tonic-gate 		 */
84*0Sstevel@tonic-gate 		ua = (char *)kernelbase;
85*0Sstevel@tonic-gate 	}
86*0Sstevel@tonic-gate 	return (copystr_nofault(ua, kaddr, maxlength, lencopied));
87*0Sstevel@tonic-gate }
88*0Sstevel@tonic-gate 
89*0Sstevel@tonic-gate int
copyoutstr_noerr(const char * kaddr,char * uaddr,size_t maxlength,size_t * lencopied)90*0Sstevel@tonic-gate copyoutstr_noerr(const char *kaddr, char *uaddr, size_t maxlength,
91*0Sstevel@tonic-gate     size_t *lencopied)
92*0Sstevel@tonic-gate {
93*0Sstevel@tonic-gate 	char *ua = (char *)uaddr;
94*0Sstevel@tonic-gate 
95*0Sstevel@tonic-gate 	ASSERT((uintptr_t)kaddr > kernelbase);
96*0Sstevel@tonic-gate 
97*0Sstevel@tonic-gate 	if ((uintptr_t)ua > kernelbase) {
98*0Sstevel@tonic-gate 		/*
99*0Sstevel@tonic-gate 		 * force fault at kernelbase
100*0Sstevel@tonic-gate 		 */
101*0Sstevel@tonic-gate 		ua = (char *)kernelbase;
102*0Sstevel@tonic-gate 	}
103*0Sstevel@tonic-gate 	return (copystr_nofault(kaddr, ua, maxlength, lencopied));
104*0Sstevel@tonic-gate }
105