osfmk/i386/mp_desc.h

   1 /*
   2  * Copyright (c) 2000-2009 Apple 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  * @OSF_COPYRIGHT@
  30  */
  31 /*
  32  * Mach Operating System
  33  * Copyright (c) 1991,1990 Carnegie Mellon University
  34  * All Rights Reserved.
  35  *
  36  * Permission to use, copy, modify and distribute this software and its
  37  * documentation is hereby granted, provided that both the copyright
  38  * notice and this permission notice appear in all copies of the
  39  * software, derivative works or modified versions, and any portions
  40  * thereof, and that both notices appear in supporting documentation.
  41  *
  42  * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
  43  * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
  44  * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
  45  *
  46  * Carnegie Mellon requests users of this software to return to
  47  *
  48  *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
  49  *  School of Computer Science
  50  *  Carnegie Mellon University
  51  *  Pittsburgh PA 15213-3890
  52  *
  53  * any improvements or extensions that they make and grant Carnegie Mellon
  54  * the rights to redistribute these changes.
  55  */
  56
  57 /*
  58  */
  59
  60 #ifndef _I386_MP_DESC_H_
  61 #define _I386_MP_DESC_H_
  62
  63 #include <mach_kdb.h>
  64 #include <sys/cdefs.h>
  65
  66 __BEGIN_DECLS
  67
  68 /*
  69  * Multiprocessor i386/i486 systems use a separate copy of the
  70  * GDT, IDT, LDT, and kernel TSS per processor.  The first three
  71  * are separate to avoid lock contention: the i386 uses locked
  72  * memory cycles to access the descriptor tables.  The TSS is
  73  * separate since each processor needs its own kernel stack,
  74  * and since using a TSS marks it busy.
  75  */
  76
  77 #include <i386/seg.h>
  78 #include <i386/tss.h>
  79
  80 /*
  81  * The descriptor tables are together in a structure
  82  * allocated one per processor (except for the boot processor).
  83  * Note that dbtss could be conditionalized on MACH_KDB, but
  84  * doing so increases misconfiguration risk.
  85  */
  86 typedef struct cpu_desc_table {
  87         struct fake_descriptor  idt[IDTSZ] __attribute__ ((aligned (16)));
  88         struct fake_descriptor  gdt[GDTSZ] __attribute__ ((aligned (16)));
  89         struct i386_tss         ktss       __attribute__ ((aligned (16)));
  90         struct i386_tss         dbtss      __attribute__ ((aligned (16)));
  91         struct sysenter_stack   sstk;
  92 } cpu_desc_table_t;
  93
  94 typedef struct cpu_desc_table64 {
  95         struct fake_descriptor64 idt[IDTSZ]      __attribute__ ((aligned (16)));
  96         struct fake_descriptor  gdt[GDTSZ]       __attribute__ ((aligned (16)));
  97         struct x86_64_tss       ktss             __attribute__ ((aligned (16)));
  98         struct sysenter_stack   sstk             __attribute__ ((aligned (16)));
  99         uint8_t                 dfstk[PAGE_SIZE] __attribute__ ((aligned (16)));
 100 } cpu_desc_table64_t;
 101
 102 #define current_gdt()   (current_cpu_datap()->cpu_desc_index.cdi_gdt.ptr)
 103 #define current_idt()   (current_cpu_datap()->cpu_desc_index.cdi_idt.ptr)
 104 #define current_ldt()   (current_cpu_datap()->cpu_desc_index.cdi_ldt)
 105 #define current_ktss()  (current_cpu_datap()->cpu_desc_index.cdi_ktss)
 106 #define current_dbtss() (current_cpu_datap()->cpu_desc_index.cdi_dbtss)
 107 #define current_sstk()  (current_cpu_datap()->cpu_desc_index.cdi_sstk)
 108
 109 #define current_ktss64() ((struct x86_64_tss *) current_ktss())
 110 #define current_sstk64() ((addr64_t *) current_sstk())
 111
 112 #define gdt_desc_p(sel) \
 113         (&((struct real_descriptor *)current_gdt())[sel_idx(sel)])
 114 #define ldt_desc_p(sel) \
 115         (&((struct real_descriptor *)current_ldt())[sel_idx(sel)])
 116
 117 extern void     cpu_mode_init(cpu_data_t *cdp);
 118
 119 extern void     cpu_desc_init(cpu_data_t *cdp);
 120 extern void     cpu_desc_init64(cpu_data_t *cdp);
 121 extern void     cpu_desc_load(cpu_data_t *cdp);
 122 extern void     cpu_desc_load64(cpu_data_t *cdp);
 123
 124 static inline boolean_t
 125 valid_user_data_selector(uint16_t selector)
 126 {
 127     sel_t       sel = selector_to_sel(selector);
 128
 129     if (selector == 0)
 130         return (TRUE);
 131
 132     if (sel.ti == SEL_LDT)
 133         return (TRUE);
 134     else if (sel.index < GDTSZ) {
 135         if ((gdt_desc_p(selector)->access & ACC_PL_U) == ACC_PL_U)
 136             return (TRUE);
 137     }
 138
 139     return (FALSE);
 140 }
 141
 142 static inline boolean_t
 143 valid_user_code_selector(uint16_t selector)
 144 {
 145     sel_t       sel = selector_to_sel(selector);
 146
 147     if (selector == 0)
 148         return (FALSE);
 149
 150     if (sel.ti == SEL_LDT) {
 151         if (sel.rpl == USER_PRIV)
 152             return (TRUE);
 153     }
 154     else if (sel.index < GDTSZ && sel.rpl == USER_PRIV) {
 155         if ((gdt_desc_p(selector)->access & ACC_PL_U) == ACC_PL_U)
 156             return (TRUE);
 157     }
 158
 159     return (FALSE);
 160 }
 161
 162 static inline boolean_t
 163 valid_user_stack_selector(uint16_t selector)
 164 {
 165     sel_t       sel = selector_to_sel(selector);
 166
 167     if (selector == 0)
 168         return (FALSE);
 169
 170     if (sel.ti == SEL_LDT) {
 171         if (sel.rpl == USER_PRIV)
 172             return (TRUE);
 173     }
 174     else if (sel.index < GDTSZ && sel.rpl == USER_PRIV) {
 175         if ((gdt_desc_p(selector)->access & ACC_PL_U) == ACC_PL_U)
 176             return (TRUE);
 177     }
 178
 179     return (FALSE);
 180 }
 181
 182 extern boolean_t
 183 valid_user_segment_selectors(uint16_t cs,
 184                              uint16_t ss,
 185                              uint16_t ds,
 186                              uint16_t es,
 187                              uint16_t fs,
 188                              uint16_t gs);
 189
 190 __END_DECLS
 191
 192 #endif  /* _X86_64_MP_DESC_H_ */