bsd/dev/i386/sel_inline.h

   1 /*
   2  * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_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. Please obtain a copy of the License at
  10  * http://www.opensource.apple.com/apsl/ and read it before using this
  11  * file.
  12  *
  13  * The Original Code and all software distributed under the License are
  14  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  15  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  16  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  17  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  18  * Please see the License for the specific language governing rights and
  19  * limitations under the License.
  20  *
  21  * @APPLE_LICENSE_HEADER_END@
  22  */
  23 /*
  24  * Copyright (c) 1992 NeXT Computer, Inc.
  25  *
  26  * Selector value conversion/validation.
  27  *
  28  * HISTORY
  29  *
  30  * 19 June 1992 ? at NeXT
  31  *      Created.
  32  */
  33
  34
  35 static inline
  36 unsigned int
  37 sel_to_selector(
  38     sel_t               sel
  39 )
  40 {
  41     union {
  42         sel_t           sel;
  43         unsigned short  selector;
  44     } tconv;
  45
  46     tconv.sel = sel;
  47
  48     return (tconv.selector);
  49 }
  50
  51 static inline
  52 sel_t
  53 selector_to_sel(
  54     unsigned int        selector
  55 )
  56 {
  57     union {
  58         unsigned short  selector;
  59         sel_t           sel;
  60     } tconv;
  61
  62     tconv.selector = selector;
  63
  64     return (tconv.sel);
  65 }
  66
  67 #if 0
  68 static inline
  69 boolean_t
  70 valid_user_data_selector(
  71     unsigned int        selector
  72 )
  73 {
  74     sel_t               sel = selector_to_sel(selector);
  75
  76     if (selector == 0)
  77         return (TRUE);
  78
  79     if (sel.ti == SEL_LDT)
  80         return (TRUE);
  81     else if (sel.index < GDTSZ) {
  82         data_desc_t     *desc = (data_desc_t *)sel_to_gdt_entry(sel);
  83
  84         if (desc->dpl == USER_PRIV)
  85             return (TRUE);
  86     }
  87
  88     return (FALSE);
  89 }
  90
  91 static inline
  92 boolean_t
  93 valid_user_code_selector(
  94     unsigned int        selector
  95 )
  96 {
  97     sel_t               sel = selector_to_sel(selector);
  98
  99     if (selector == 0)
 100         return (FALSE);
 101
 102     if (sel.ti == SEL_LDT) {
 103         if (sel.rpl == USER_PRIV)
 104             return (TRUE);
 105     }
 106     else if (sel.index < GDTSZ && sel.rpl == USER_PRIV) {
 107         code_desc_t     *desc = (code_desc_t *)sel_to_gdt_entry(sel);
 108
 109         if (desc->dpl == USER_PRIV)
 110             return (TRUE);
 111     }
 112
 113     return (FALSE);
 114 }
 115
 116 static inline
 117 boolean_t
 118 valid_user_stack_selector(
 119     unsigned int        selector
 120 )
 121 {
 122     sel_t               sel = selector_to_sel(selector);
 123
 124     if (selector == 0)
 125         return (FALSE);
 126
 127     if (sel.ti == SEL_LDT) {
 128         if (sel.rpl == USER_PRIV)
 129             return (TRUE);
 130     }
 131     else if (sel.index < GDTSZ && sel.rpl == USER_PRIV) {
 132         data_desc_t     *desc = (data_desc_t *)sel_to_gdt_entry(sel);
 133
 134         if (desc->dpl == USER_PRIV)
 135             return (TRUE);
 136     }
 137
 138     return (FALSE);
 139 }
 140 #endif