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  * Copyright (c) 1999-2003 Apple Computer, Inc.  All Rights Reserved.
   7  *
   8  * This file contains Original Code and/or Modifications of Original Code
   9  * as defined in and that are subject to the Apple Public Source License
  10  * Version 2.0 (the 'License'). You may not use this file except in
  11  * compliance with the License. Please obtain a copy of the License at
  12  * http://www.opensource.apple.com/apsl/ and read it before using this
  13  * file.
  14  *
  15  * The Original Code and all software distributed under the License are
  16  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  17  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  18  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  19  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  20  * Please see the License for the specific language governing rights and
  21  * limitations under the License.
  22  *
  23  * @APPLE_LICENSE_HEADER_END@
  24  */
  25 /*
  26  * Copyright (c) 1992 NeXT Computer, Inc.
  27  *
  28  * Selector value conversion/validation.
  29  *
  30  * HISTORY
  31  *
  32  * 19 June 1992 ? at NeXT
  33  *      Created.
  34  */
  35
  36
  37 static inline
  38 unsigned int
  39 sel_to_selector(
  40     sel_t               sel
  41 )
  42 {
  43     union {
  44         sel_t           sel;
  45         unsigned short  selector;
  46     } tconv;
  47
  48     tconv.sel = sel;
  49
  50     return (tconv.selector);
  51 }
  52
  53 static inline
  54 sel_t
  55 selector_to_sel(
  56     unsigned int        selector
  57 )
  58 {
  59     union {
  60         unsigned short  selector;
  61         sel_t           sel;
  62     } tconv;
  63
  64     tconv.selector = selector;
  65
  66     return (tconv.sel);
  67 }
  68
  69 #if 0
  70 static inline
  71 boolean_t
  72 valid_user_data_selector(
  73     unsigned int        selector
  74 )
  75 {
  76     sel_t               sel = selector_to_sel(selector);
  77
  78     if (selector == 0)
  79         return (TRUE);
  80
  81     if (sel.ti == SEL_LDT)
  82         return (TRUE);
  83     else if (sel.index < GDTSZ) {
  84         data_desc_t     *desc = (data_desc_t *)sel_to_gdt_entry(sel);
  85
  86         if (desc->dpl == USER_PRIV)
  87             return (TRUE);
  88     }
  89
  90     return (FALSE);
  91 }
  92
  93 static inline
  94 boolean_t
  95 valid_user_code_selector(
  96     unsigned int        selector
  97 )
  98 {
  99     sel_t               sel = selector_to_sel(selector);
 100
 101     if (selector == 0)
 102         return (FALSE);
 103
 104     if (sel.ti == SEL_LDT) {
 105         if (sel.rpl == USER_PRIV)
 106             return (TRUE);
 107     }
 108     else if (sel.index < GDTSZ && sel.rpl == USER_PRIV) {
 109         code_desc_t     *desc = (code_desc_t *)sel_to_gdt_entry(sel);
 110
 111         if (desc->dpl == USER_PRIV)
 112             return (TRUE);
 113     }
 114
 115     return (FALSE);
 116 }
 117
 118 static inline
 119 boolean_t
 120 valid_user_stack_selector(
 121     unsigned int        selector
 122 )
 123 {
 124     sel_t               sel = selector_to_sel(selector);
 125
 126     if (selector == 0)
 127         return (FALSE);
 128
 129     if (sel.ti == SEL_LDT) {
 130         if (sel.rpl == USER_PRIV)
 131             return (TRUE);
 132     }
 133     else if (sel.index < GDTSZ && sel.rpl == USER_PRIV) {
 134         data_desc_t     *desc = (data_desc_t *)sel_to_gdt_entry(sel);
 135
 136         if (desc->dpl == USER_PRIV)
 137             return (TRUE);
 138     }
 139
 140     return (FALSE);
 141 }
 142 #endif