osfmk/i386/mp_desc.h

   1 /*
   2  * Copyright (c) 2000-2005 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * The contents of this file constitute Original Code as defined in and
   7  * are subject to the Apple Public Source License Version 1.1 (the
   8  * "License").  You may not use this file except in compliance with the
   9  * License.  Please obtain a copy of the License at
  10  * http://www.apple.com/publicsource and read it before using this file.
  11  *
  12  * This Original Code and all software distributed under the License are
  13  * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  14  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  15  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  16  * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
  17  * License for the specific language governing rights and limitations
  18  * under the License.
  19  *
  20  * @APPLE_LICENSE_HEADER_END@
  21  */
  22 /*
  23  * @OSF_COPYRIGHT@
  24  */
  25 /*
  26  * Mach Operating System
  27  * Copyright (c) 1991,1990 Carnegie Mellon University
  28  * All Rights Reserved.
  29  *
  30  * Permission to use, copy, modify and distribute this software and its
  31  * documentation is hereby granted, provided that both the copyright
  32  * notice and this permission notice appear in all copies of the
  33  * software, derivative works or modified versions, and any portions
  34  * thereof, and that both notices appear in supporting documentation.
  35  *
  36  * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
  37  * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
  38  * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
  39  *
  40  * Carnegie Mellon requests users of this software to return to
  41  *
  42  *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
  43  *  School of Computer Science
  44  *  Carnegie Mellon University
  45  *  Pittsburgh PA 15213-3890
  46  *
  47  * any improvements or extensions that they make and grant Carnegie Mellon
  48  * the rights to redistribute these changes.
  49  */
  50
  51 /*
  52  */
  53
  54 #ifndef _I386_MP_DESC_H_
  55 #define _I386_MP_DESC_H_
  56
  57 #include <mach_kdb.h>
  58 #include <sys/cdefs.h>
  59
  60 __BEGIN_DECLS
  61
  62 /*
  63  * Multiprocessor i386/i486 systems use a separate copy of the
  64  * GDT, IDT, LDT, and kernel TSS per processor.  The first three
  65  * are separate to avoid lock contention: the i386 uses locked
  66  * memory cycles to access the descriptor tables.  The TSS is
  67  * separate since each processor needs its own kernel stack,
  68  * and since using a TSS marks it busy.
  69  */
  70
  71 #include <i386/seg.h>
  72 #include <i386/tss.h>
  73
  74 /*
  75  * The descriptor tables are together in a structure
  76  * allocated one per processor (except for the boot processor).
  77  * Note that dbtss could be conditionalized on MACH_KDB, but
  78  * doing so increases misconfiguration risk.
  79  */
  80 typedef struct cpu_desc_table {
  81         struct fake_descriptor  idt[IDTSZ] __attribute__ ((aligned (16)));
  82         struct fake_descriptor  gdt[GDTSZ] __attribute__ ((aligned (16)));
  83         struct i386_tss         ktss       __attribute__ ((aligned (16)));
  84         struct i386_tss         dbtss      __attribute__ ((aligned (16)));
  85         struct sysenter_stack   sstk;
  86 } cpu_desc_table_t;
  87
  88 typedef struct cpu_desc_table64 {
  89         struct fake_descriptor64 idt[IDTSZ]      __attribute__ ((aligned (16)));
  90         struct fake_descriptor  gdt[GDTSZ]       __attribute__ ((aligned (16)));
  91         struct x86_64_tss       ktss             __attribute__ ((aligned (16)));
  92         struct sysenter_stack   sstk             __attribute__ ((aligned (16)));
  93         uint8_t                 dfstk[PAGE_SIZE] __attribute__ ((aligned (16)));
  94 } cpu_desc_table64_t;
  95
  96 #define current_gdt()   (current_cpu_datap()->cpu_desc_index.cdi_gdt)
  97 #define current_idt()   (current_cpu_datap()->cpu_desc_index.cdi_idt)
  98 #define current_ldt()   (current_cpu_datap()->cpu_desc_index.cdi_ldt)
  99 #define current_ktss()  (current_cpu_datap()->cpu_desc_index.cdi_ktss)
 100 #define current_dbtss() (current_cpu_datap()->cpu_desc_index.cdi_dbtss)
 101 #define current_sstk()  (current_cpu_datap()->cpu_desc_index.cdi_sstk)
 102
 103 #define current_ktss64() ((struct x86_64_tss *) current_ktss())
 104 #define current_sstk64() ((addr64_t *) current_sstk())
 105
 106 #define gdt_desc_p(sel) \
 107         ((struct real_descriptor *)&current_gdt()[sel_idx(sel)])
 108 #define ldt_desc_p(sel) \
 109         ((struct real_descriptor *)&current_ldt()[sel_idx(sel)])
 110
 111 extern void     cpu_desc_init(
 112                         cpu_data_t      *cdp,
 113                         boolean_t       is_boot_cpu);
 114 extern void     cpu_desc_init64(
 115                         cpu_data_t      *cdp,
 116                         boolean_t       is_boot_cpu);
 117 extern void     cpu_desc_load64(
 118                         cpu_data_t      *cdp);
 119 extern void     fast_syscall_init(void);
 120 extern void     fast_syscall_init64(void);
 121
 122 static inline boolean_t
 123 valid_user_data_selector(uint16_t selector)
 124 {
 125     sel_t       sel = selector_to_sel(selector);
 126
 127     if (selector == 0)
 128         return (TRUE);
 129
 130     if (sel.ti == SEL_LDT)
 131         return (TRUE);
 132     else if (sel.index < GDTSZ) {
 133         if ((gdt_desc_p(selector)->access & ACC_PL_U) == ACC_PL_U)
 134             return (TRUE);
 135     }
 136
 137     return (FALSE);
 138 }
 139
 140 static inline boolean_t
 141 valid_user_code_selector(uint16_t selector)
 142 {
 143     sel_t       sel = selector_to_sel(selector);
 144
 145     if (selector == 0)
 146         return (FALSE);
 147
 148     if (sel.ti == SEL_LDT) {
 149         if (sel.rpl == USER_PRIV)
 150             return (TRUE);
 151     }
 152     else if (sel.index < GDTSZ && sel.rpl == USER_PRIV) {
 153         if ((gdt_desc_p(selector)->access & ACC_PL_U) == ACC_PL_U)
 154             return (TRUE);
 155     }
 156
 157     return (FALSE);
 158 }
 159
 160 static inline boolean_t
 161 valid_user_stack_selector(uint16_t selector)
 162 {
 163     sel_t       sel = selector_to_sel(selector);
 164
 165     if (selector == 0)
 166         return (FALSE);
 167
 168     if (sel.ti == SEL_LDT) {
 169         if (sel.rpl == USER_PRIV)
 170             return (TRUE);
 171     }
 172     else if (sel.index < GDTSZ && sel.rpl == USER_PRIV) {
 173         if ((gdt_desc_p(selector)->access & ACC_PL_U) == ACC_PL_U)
 174             return (TRUE);
 175     }
 176
 177     return (FALSE);
 178 }
 179
 180 extern boolean_t
 181 valid_user_segment_selectors(uint16_t cs,
 182                              uint16_t ss,
 183                              uint16_t ds,
 184                              uint16_t es,
 185                              uint16_t fs,
 186                              uint16_t gs);
 187
 188 __END_DECLS
 189
 190 #endif  /* _I386_MP_DESC_H_ */