1/*
2 * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
3 *
4 * @APPLE_OSREFERENCE_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. The rights granted to you under the License
10 * may not be used to create, or enable the creation or redistribution of,
11 * unlawful or unlicensed copies of an Apple operating system, or to
12 * circumvent, violate, or enable the circumvention or violation of, any
13 * terms of an Apple operating system software license agreement.
14 *
15 * Please obtain a copy of the License at
16 * http://www.opensource.apple.com/apsl/ and read it before using this file.
17 *
18 * The Original Code and all software distributed under the License are
19 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
20 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
21 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
22 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
23 * Please see the License for the specific language governing rights and
24 * limitations under the License.
25 *
26 * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
27 */
28/*
29 * Copyright (c) 1992 NeXT Computer, Inc.
30 *
31 * Selector value conversion/validation.
32 *
33 * HISTORY
34 *
35 * 19 June 1992 ? at NeXT
36 *	Created.
37 */
38
39
40static inline
41unsigned int
42sel_to_selector(
43    sel_t		sel
44)
45{
46    union {
47	sel_t		sel;
48	unsigned short	selector;
49    } tconv;
50
51    tconv.sel = sel;
52
53    return (tconv.selector);
54}
55
56static inline
57sel_t
58selector_to_sel(
59    unsigned int	selector
60)
61{
62    union {
63	unsigned short	selector;
64	sel_t		sel;
65    } tconv;
66
67    tconv.selector = selector;
68
69    return (tconv.sel);
70}
71
72#if 0
73static inline
74boolean_t
75valid_user_data_selector(
76    unsigned int	selector
77)
78{
79    sel_t		sel = selector_to_sel(selector);
80
81    if (selector == 0)
82    	return (TRUE);
83
84    if (sel.ti == SEL_LDT)
85	return (TRUE);
86    else if (sel.index < GDTSZ) {
87	data_desc_t	*desc = (data_desc_t *)sel_to_gdt_entry(sel);
88
89	if (desc->dpl == USER_PRIV)
90	    return (TRUE);
91    }
92
93    return (FALSE);
94}
95
96static inline
97boolean_t
98valid_user_code_selector(
99    unsigned int	selector
100)
101{
102    sel_t		sel = selector_to_sel(selector);
103
104    if (selector == 0)
105    	return (FALSE);
106
107    if (sel.ti == SEL_LDT) {
108	if (sel.rpl == USER_PRIV)
109	    return (TRUE);
110    }
111    else if (sel.index < GDTSZ && sel.rpl == USER_PRIV) {
112    	code_desc_t	*desc = (code_desc_t *)sel_to_gdt_entry(sel);
113
114	if (desc->dpl == USER_PRIV)
115	    return (TRUE);
116    }
117
118    return (FALSE);
119}
120
121static inline
122boolean_t
123valid_user_stack_selector(
124    unsigned int	selector
125)
126{
127    sel_t		sel = selector_to_sel(selector);
128
129    if (selector == 0)
130    	return (FALSE);
131
132    if (sel.ti == SEL_LDT) {
133	if (sel.rpl == USER_PRIV)
134	    return (TRUE);
135    }
136    else if (sel.index < GDTSZ && sel.rpl == USER_PRIV) {
137	data_desc_t	*desc = (data_desc_t *)sel_to_gdt_entry(sel);
138
139	if (desc->dpl == USER_PRIV)
140	    return (TRUE);
141    }
142
143    return (FALSE);
144}
145#endif
146