bsd/dev/i386/sel_inline.h

   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
  40 static inline
  41 unsigned int
  42 sel_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
  56 static inline
  57 sel_t
  58 selector_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
  73 static inline
  74 boolean_t
  75 valid_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
  96 static inline
  97 boolean_t
  98 valid_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
 121 static inline
 122 boolean_t
 123 valid_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