mach/mach_init.c

   1 /*
   2  * Copyright (c) 1999 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_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. Please obtain a copy of the License at
  10  * http://www.opensource.apple.com/apsl/ and read it before using this
  11  * file.
  12  *
  13  * The Original Code and all software distributed under the License are
  14  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  15  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  16  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  17  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  18  * Please see the License for the specific language governing rights and
  19  * limitations under the License.
  20  *
  21  * @APPLE_LICENSE_HEADER_END@
  22  */
  23 /*
  24  * Mach Operating System
  25  * Copyright (c) 1991,1990,1989,1988,1987 Carnegie Mellon University
  26  * All Rights Reserved.
  27  *
  28  * Permission to use, copy, modify and distribute this software and its
  29  * documentation is hereby granted, provided that both the copyright
  30  * notice and this permission notice appear in all copies of the
  31  * software, derivative works or modified versions, and any portions
  32  * thereof, and that both notices appear in supporting documentation.
  33  *
  34  * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
  35  * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
  36  * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
  37  *
  38  * Carnegie Mellon requests users of this software to return to
  39  *
  40  *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
  41  *  School of Computer Science
  42  *  Carnegie Mellon University
  43  *  Pittsburgh PA 15213-3890
  44  *
  45  * any improvements or extensions that they make and grant Carnegie Mellon
  46  * the rights to redistribute these changes.
  47  */
  48
  49 #include <mach/mach.h>
  50 #include <mach/boolean.h>
  51 #include <mach/machine/ndr_def.h>
  52 #include <mach/mach_traps.h>
  53 #include <mach/mach_host.h>
  54 #include <mach/mach_init.h>
  55 #include "externs.h"
  56
  57 mach_port_t     mach_task_self_ = MACH_PORT_NULL;
  58 mach_port_t     mach_host_self_ = MACH_PORT_NULL;
  59
  60 __private_extern__ kern_return_t _host_mach_msg_trap_return_;
  61
  62 vm_size_t       vm_page_size;
  63
  64 /*
  65  * Forward internal declarations for automatic mach_init during
  66  * fork() implementation.
  67  */
  68 /* fork() calls through atfork_child_routine */
  69 void (*_atfork_child_routine)(void);
  70
  71 static void mach_atfork_child_routine(void);
  72 static boolean_t first = TRUE;
  73 static void (*previous_atfork_child_routine)(void);
  74 extern int mach_init(void);
  75 extern void _pthread_set_self(void *);
  76 extern void cthread_set_self(void *);
  77
  78
  79 static void mach_atfork_child_routine(void)
  80 {
  81         /*
  82          * If an (*_atfork_child_routine)() was registered when
  83          * mach_init was first called, then call that routine
  84          * prior to performing our re-initialization. This ensures
  85          * that the post-fork handlers are called in exactly the
  86          * same order as the crt0 (exec) handlers. Any library
  87          * that makes use of the _atfork_child_routine must follow
  88          * the same technique.
  89          */
  90         if (previous_atfork_child_routine) {
  91                 (*previous_atfork_child_routine)();
  92         }
  93         mach_init();
  94 }
  95
  96 mach_port_t
  97 mach_host_self()
  98 {
  99         return(host_self_trap());
 100 }
 101
 102 int mach_init_doit(int forkchild)
 103 {
 104         host_t host;
 105
 106         /*
 107          *      Get the important ports into the cached values,
 108          *      as required by "mach_init.h".
 109          */
 110
 111         mach_task_self_ = task_self_trap();
 112         host = host_self_trap();
 113
 114
 115         if (!forkchild) {
 116                 /*
 117                  * Set up the post-fork child handler in the libc stub
 118                  * to invoke this routine if this process forks. Save the
 119                  * previous value in order that we can call that handler
 120                  * prior to performing our postfork work.
 121                  */
 122
 123                 first = FALSE;
 124                 previous_atfork_child_routine = _atfork_child_routine;
 125                 _atfork_child_routine = mach_atfork_child_routine;
 126                 _pthread_set_self(0);
 127                 cthread_set_self(0);
 128         }
 129
 130         /*
 131          *      Initialize the single mig reply port
 132          */
 133
 134         mig_init(0);
 135
 136         /*
 137          *      Cache some other valuable system constants
 138          */
 139
 140         (void)host_page_size(host, &vm_page_size);
 141
 142         mach_port_deallocate(mach_task_self_, host);
 143
 144         mach_init_ports();
 145
 146 #if WE_REALLY_NEED_THIS_GDB_HACK
 147         /*
 148          * Check to see if GDB wants us to stop
 149          */
 150         {
 151           task_user_data_data_t user_data;
 152           mach_msg_type_number_t        user_data_count = TASK_USER_DATA_COUNT;
 153
 154         user_data.user_data = 0;
 155         (void)task_info(mach_task_self_, TASK_USER_DATA,
 156                 (task_info_t)&user_data, &user_data_count);
 157 #define MACH_GDB_RUN_MAGIC_NUMBER 1
 158 #ifdef  MACH_GDB_RUN_MAGIC_NUMBER
 159           /* This magic number is set in mach-aware gdb
 160            *  for RUN command to allow us to suspend user's
 161            *  executable (linked with this libmach!)
 162            *  with the code below.
 163         * This hack should disappear when gdb improves.
 164         */
 165         if ((int)user_data.user_data == MACH_GDB_RUN_MAGIC_NUMBER) {
 166             kern_return_t ret;
 167             user_data.user_data = 0;
 168
 169             ret = task_suspend (mach_task_self_);
 170             if (ret != KERN_SUCCESS) {
 171                 while(1) (void)task_terminate(mach_task_self_);
 172             }
 173         }
 174 #undef MACH_GDB_RUN_MAGIC_NUMBER
 175 #endif /* MACH_GDB_RUN_MAGIC_NUMBER */
 176         }
 177 #endif /* WE_REALLY_NEED_THIS_GDB_HACK */
 178
 179         /*
 180          * Reserve page 0 so that the program doesn't get it as
 181          * the result of a vm_allocate() or whatever.
 182          */
 183         {
 184                 vm_offset_t zero_page_start;
 185
 186                 zero_page_start = 0;
 187                 (void)vm_map(mach_task_self_, &zero_page_start, vm_page_size,
 188                              0, FALSE, MEMORY_OBJECT_NULL, 0, TRUE,
 189                              VM_PROT_NONE, VM_PROT_NONE, VM_INHERIT_COPY);
 190                 /* ignore result, we don't care if it failed */
 191         }
 192         return(0);
 193 }
 194
 195 int mach_init(void)
 196 {
 197         return(mach_init_doit(0));
 198 }
 199
 200 int     (*mach_init_routine)(void) = mach_init;
 201 int fork_mach_init()
 202 {
 203         /* called only from child */
 204         return(mach_init_doit(1));
 205 }
 206
 207 #undef  mach_task_self
 208
 209 mach_port_t
 210 mach_task_self()
 211 {
 212         return(task_self_trap());
 213 }
 214
 215 mach_port_t
 216 mach_thread_self()
 217 {
 218         return(thread_self_trap());
 219 }