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
  66 /*
  67  * Forward internal declarations for automatic mach_init during
  68  * fork() implementation.
  69  */
  70 /* fork() calls through atfork_child_routine */
  71 void (*_atfork_child_routine)(void);
  72
  73 static void mach_atfork_child_routine(void);
  74 static boolean_t first = TRUE;
  75 static void (*previous_atfork_child_routine)(void);
  76 extern int mach_init(void);
  77 extern void _pthread_set_self(void *);
  78 extern void cthread_set_self(void *);
  79
  80
  81 static void mach_atfork_child_routine(void)
  82 {
  83         /*
  84          * If an (*_atfork_child_routine)() was registered when
  85          * mach_init was first called, then call that routine
  86          * prior to performing our re-initialization. This ensures
  87          * that the post-fork handlers are called in exactly the
  88          * same order as the crt0 (exec) handlers. Any library
  89          * that makes use of the _atfork_child_routine must follow
  90          * the same technique.
  91          */
  92         if (previous_atfork_child_routine) {
  93                 (*previous_atfork_child_routine)();
  94         }
  95         mach_init();
  96 }
  97
  98 mach_port_t
  99 mach_host_self()
 100 {
 101         return(host_self_trap());
 102 }
 103
 104 int mach_init_doit(int forkchild)
 105 {
 106         host_t host;
 107
 108         /*
 109          *      Get the important ports into the cached values,
 110          *      as required by "mach_init.h".
 111          */
 112
 113         mach_task_self_ = task_self_trap();
 114         host = host_self_trap();
 115
 116
 117         if (!forkchild) {
 118                 /*
 119                  * Set up the post-fork child handler in the libc stub
 120                  * to invoke this routine if this process forks. Save the
 121                  * previous value in order that we can call that handler
 122                  * prior to performing our postfork work.
 123                  */
 124
 125                 first = FALSE;
 126                 previous_atfork_child_routine = _atfork_child_routine;
 127                 _atfork_child_routine = mach_atfork_child_routine;
 128                 _pthread_set_self(0);
 129                 cthread_set_self(0);
 130         }
 131
 132         /*
 133          *      Initialize the single mig reply port
 134          */
 135
 136         mig_init(0);
 137
 138         /*
 139          *      Cache some other valuable system constants
 140          */
 141
 142         (void)host_page_size(host, &vm_page_size);
 143
 144         mach_port_deallocate(mach_task_self_, host);
 145
 146         mach_init_ports();
 147
 148 #if WE_REALLY_NEED_THIS_GDB_HACK
 149         /*
 150          * Check to see if GDB wants us to stop
 151          */
 152         {
 153           task_user_data_data_t user_data;
 154           mach_msg_type_number_t        user_data_count = TASK_USER_DATA_COUNT;
 155
 156         user_data.user_data = 0;
 157         (void)task_info(mach_task_self_, TASK_USER_DATA,
 158                 (task_info_t)&user_data, &user_data_count);
 159 #define MACH_GDB_RUN_MAGIC_NUMBER 1
 160 #ifdef  MACH_GDB_RUN_MAGIC_NUMBER
 161           /* This magic number is set in mach-aware gdb
 162            *  for RUN command to allow us to suspend user's
 163            *  executable (linked with this libmach!)
 164            *  with the code below.
 165         * This hack should disappear when gdb improves.
 166         */
 167         if ((int)user_data.user_data == MACH_GDB_RUN_MAGIC_NUMBER) {
 168             kern_return_t ret;
 169             user_data.user_data = 0;
 170
 171             ret = task_suspend (mach_task_self_);
 172             if (ret != KERN_SUCCESS) {
 173                 while(1) (void)task_terminate(mach_task_self_);
 174             }
 175         }
 176 #undef MACH_GDB_RUN_MAGIC_NUMBER
 177 #endif /* MACH_GDB_RUN_MAGIC_NUMBER */
 178         }
 179 #endif /* WE_REALLY_NEED_THIS_GDB_HACK */
 180
 181         /*
 182          * Reserve page 0 so that the program doesn't get it as
 183          * the result of a vm_allocate() or whatever.
 184          */
 185         {
 186                 vm_offset_t zero_page_start;
 187
 188                 zero_page_start = 0;
 189                 (void)vm_map(mach_task_self_, &zero_page_start, vm_page_size,
 190                              0, FALSE, MEMORY_OBJECT_NULL, 0, TRUE,
 191                              VM_PROT_NONE, VM_PROT_NONE, VM_INHERIT_COPY);
 192                 /* ignore result, we don't care if it failed */
 193         }
 194         return(0);
 195 }
 196
 197 int mach_init(void)
 198 {
 199         return(mach_init_doit(0));
 200 }
 201
 202 int     (*mach_init_routine)(void) = mach_init;
 203 int fork_mach_init()
 204 {
 205         /* called only from child */
 206         return(mach_init_doit(1));
 207 }
 208
 209 #undef  mach_task_self
 210
 211 mach_port_t
 212 mach_task_self()
 213 {
 214         return(task_self_trap());
 215 }
 216
 217 mach_port_t
 218 mach_thread_self()
 219 {
 220         return(thread_self_trap());
 221 }