bsd/dev/i386/sel_inline.h

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