mach/mach_init.c

   1 /*
   2  * Copyright (c) 1999 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  * Mach Operating System
  27  * Copyright (c) 1991,1990,1989,1988,1987 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 #include <mach/mach.h>
  52 #include <mach/boolean.h>
  53 #include <mach/machine/ndr_def.h>
  54 #include <mach/mach_traps.h>
  55 #include <mach/mach_host.h>
  56 #include <mach/mach_init.h>
  57 #include "externs.h"
  58
  59 mach_port_t     mach_task_self_ = MACH_PORT_NULL;
  60 mach_port_t     mach_host_self_ = MACH_PORT_NULL;
  61
  62 __private_extern__ kern_return_t _host_mach_msg_trap_return_;
  63
  64 vm_size_t       vm_page_size;
  65 vm_size_t       vm_page_mask;
  66 int             vm_page_shift;
  67
  68 /*
  69  * Forward internal declarations for automatic mach_init during
  70  * fork() implementation.
  71  */
  72 /* fork() calls through atfork_child_routine */
  73 void (*_atfork_child_routine)(void);
  74
  75 static void mach_atfork_child_routine(void);
  76 static boolean_t first = TRUE;
  77 static void (*previous_atfork_child_routine)(void);
  78 extern int mach_init(void);
  79 extern void _pthread_set_self(void *);
  80 extern void cthread_set_self(void *);
  81
  82
  83 static void mach_atfork_child_routine(void)
  84 {
  85         /*
  86          * If an (*_atfork_child_routine)() was registered when
  87          * mach_init was first called, then call that routine
  88          * prior to performing our re-initialization. This ensures
  89          * that the post-fork handlers are called in exactly the
  90          * same order as the crt0 (exec) handlers. Any library
  91          * that makes use of the _atfork_child_routine must follow
  92          * the same technique.
  93          */
  94         if (previous_atfork_child_routine) {
  95                 (*previous_atfork_child_routine)();
  96         }
  97         mach_init();
  98 }
  99
 100 mach_port_t
 101 mach_host_self()
 102 {
 103         return(host_self_trap());
 104 }
 105
 106 int mach_init_doit(int forkchild)
 107 {
 108         host_t host;
 109
 110         /*
 111          *      Get the important ports into the cached values,
 112          *      as required by "mach_init.h".
 113          */
 114
 115         mach_task_self_ = task_self_trap();
 116         host = host_self_trap();
 117
 118
 119         if (!forkchild) {
 120                 /*
 121                  * Set up the post-fork child handler in the libc stub
 122                  * to invoke this routine if this process forks. Save the
 123                  * previous value in order that we can call that handler
 124                  * prior to performing our postfork work.
 125                  */
 126
 127                 first = FALSE;
 128                 previous_atfork_child_routine = _atfork_child_routine;
 129                 _atfork_child_routine = mach_atfork_child_routine;
 130                 _pthread_set_self(0);
 131                 cthread_set_self(0);
 132         }
 133
 134         /*
 135          *      Initialize the single mig reply port
 136          */
 137
 138         mig_init(0);
 139
 140         /*
 141          *      Cache some other valuable system constants
 142          */
 143
 144 #if defined(__ppc64__) /* NGK hack for now */
 145         vm_page_size = 4096;
 146 #else
 147         (void)host_page_size(host, &vm_page_size);
 148 #endif
 149         vm_page_mask = vm_page_size - 1;
 150         if (vm_page_size == 0) {
 151                 /* guard against unlikely craziness */
 152                 vm_page_shift = 0;
 153         } else {
 154                 /*
 155                  * Unfortunately there's no kernel interface to get the
 156                  * vm_page_shift, but it's easy enough to calculate.
 157                  */
 158                 for (vm_page_shift = 0;
 159                      (vm_page_size & (1 << vm_page_shift)) == 0;
 160                      vm_page_shift++)
 161                         continue;
 162         }
 163
 164         mach_port_deallocate(mach_task_self_, host);
 165
 166         mach_init_ports();
 167
 168 #if WE_REALLY_NEED_THIS_GDB_HACK
 169         /*
 170          * Check to see if GDB wants us to stop
 171          */
 172         {
 173           task_user_data_data_t user_data;
 174           mach_msg_type_number_t        user_data_count = TASK_USER_DATA_COUNT;
 175
 176         user_data.user_data = 0;
 177         (void)task_info(mach_task_self_, TASK_USER_DATA,
 178                 (task_info_t)&user_data, &user_data_count);
 179 #define MACH_GDB_RUN_MAGIC_NUMBER 1
 180 #ifdef  MACH_GDB_RUN_MAGIC_NUMBER
 181           /* This magic number is set in mach-aware gdb
 182            *  for RUN command to allow us to suspend user's
 183            *  executable (linked with this libmach!)
 184            *  with the code below.
 185         * This hack should disappear when gdb improves.
 186         */
 187         if ((int)user_data.user_data == MACH_GDB_RUN_MAGIC_NUMBER) {
 188             kern_return_t ret;
 189             user_data.user_data = 0;
 190
 191             ret = task_suspend (mach_task_self_);
 192             if (ret != KERN_SUCCESS) {
 193                 while(1) (void)task_terminate(mach_task_self_);
 194             }
 195         }
 196 #undef MACH_GDB_RUN_MAGIC_NUMBER
 197 #endif /* MACH_GDB_RUN_MAGIC_NUMBER */
 198         }
 199 #endif /* WE_REALLY_NEED_THIS_GDB_HACK */
 200
 201         /*
 202          * Reserve page 0 so that the program doesn't get it as
 203          * the result of a vm_allocate() or whatever.
 204          */
 205         {
 206                 vm_offset_t zero_page_start;
 207
 208                 zero_page_start = 0;
 209                 (void)vm_map(mach_task_self_, &zero_page_start, vm_page_size,
 210                              0, FALSE, MEMORY_OBJECT_NULL, 0, TRUE,
 211                              VM_PROT_NONE, VM_PROT_NONE, VM_INHERIT_COPY);
 212                 /* ignore result, we don't care if it failed */
 213         }
 214         return(0);
 215 }
 216
 217 int mach_init(void)
 218 {
 219         return(mach_init_doit(0));
 220 }
 221
 222 int     (*mach_init_routine)(void) = mach_init;
 223 int fork_mach_init()
 224 {
 225         /* called only from child */
 226         return(mach_init_doit(1));
 227 }
 228
 229 #undef  mach_task_self
 230
 231 mach_port_t
 232 mach_task_self()
 233 {
 234         return(task_self_trap());
 235 }
 236
 237 mach_port_t
 238 mach_thread_self()
 239 {
 240         return(thread_self_trap());
 241 }