mach/mach_init.c

   1 /*
   2  * Copyright (c) 1999 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  * Mach Operating System
  24  * Copyright (c) 1991,1990,1989,1988,1987 Carnegie Mellon University
  25  * All Rights Reserved.
  26  *
  27  * Permission to use, copy, modify and distribute this software and its
  28  * documentation is hereby granted, provided that both the copyright
  29  * notice and this permission notice appear in all copies of the
  30  * software, derivative works or modified versions, and any portions
  31  * thereof, and that both notices appear in supporting documentation.
  32  *
  33  * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
  34  * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
  35  * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
  36  *
  37  * Carnegie Mellon requests users of this software to return to
  38  *
  39  *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
  40  *  School of Computer Science
  41  *  Carnegie Mellon University
  42  *  Pittsburgh PA 15213-3890
  43  *
  44  * any improvements or extensions that they make and grant Carnegie Mellon
  45  * the rights to redistribute these changes.
  46  */
  47
  48 #include <mach/mach.h>
  49 #include <mach/boolean.h>
  50 #include <mach/machine/ndr_def.h>
  51 #include <mach/mach_traps.h>
  52 #include <mach/mach_host.h>
  53 #include <mach/mach_init.h>
  54 #include "externs.h"
  55
  56 mach_port_t     mach_task_self_ = MACH_PORT_NULL;
  57 mach_port_t     mach_host_self_ = MACH_PORT_NULL;
  58
  59 __private_extern__ kern_return_t _host_mach_msg_trap_return_;
  60
  61 vm_size_t       vm_page_size;
  62
  63 /*
  64  * Forward internal declarations for automatic mach_init during
  65  * fork() implementation.
  66  */
  67 /* fork() calls through atfork_child_routine */
  68 void (*_atfork_child_routine)(void);
  69
  70 static void mach_atfork_child_routine(void);
  71 static boolean_t first = TRUE;
  72 static void (*previous_atfork_child_routine)(void);
  73 extern int mach_init(void);
  74 extern void _pthread_set_self(void *);
  75 extern void cthread_set_self(void *);
  76
  77
  78 static void mach_atfork_child_routine(void)
  79 {
  80         /*
  81          * If an (*_atfork_child_routine)() was registered when
  82          * mach_init was first called, then call that routine
  83          * prior to performing our re-initialization. This ensures
  84          * that the post-fork handlers are called in exactly the
  85          * same order as the crt0 (exec) handlers. Any library
  86          * that makes use of the _atfork_child_routine must follow
  87          * the same technique.
  88          */
  89         if (previous_atfork_child_routine) {
  90                 (*previous_atfork_child_routine)();
  91         }
  92         mach_init();
  93 }
  94
  95 mach_port_t
  96 mach_host_self()
  97 {
  98         return(host_self_trap());
  99 }
 100
 101 int mach_init_doit(int forkchild)
 102 {
 103         mach_msg_type_number_t host_info_size;
 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 #ifdef HOST_MACH_MSG_TRAP
 141         host_info_size = 0;
 142         _host_mach_msg_trap_return_ = host_info(host,
 143                                            HOST_MACH_MSG_TRAP,
 144                                            0,
 145                                            &host_info_size);
 146 #endif
 147
 148         (void)host_page_size(host, &vm_page_size);
 149
 150         mach_port_deallocate(mach_task_self_, host);
 151
 152         mach_init_ports();
 153
 154 #if WE_REALLY_NEED_THIS_GDB_HACK
 155         /*
 156          * Check to see if GDB wants us to stop
 157          */
 158         {
 159           task_user_data_data_t user_data;
 160           mach_msg_type_number_t        user_data_count = TASK_USER_DATA_COUNT;
 161
 162         user_data.user_data = 0;
 163         (void)task_info(mach_task_self_, TASK_USER_DATA,
 164                 (task_info_t)&user_data, &user_data_count);
 165 #define MACH_GDB_RUN_MAGIC_NUMBER 1
 166 #ifdef  MACH_GDB_RUN_MAGIC_NUMBER
 167           /* This magic number is set in mach-aware gdb
 168            *  for RUN command to allow us to suspend user's
 169            *  executable (linked with this libmach!)
 170            *  with the code below.
 171         * This hack should disappear when gdb improves.
 172         */
 173         if ((int)user_data.user_data == MACH_GDB_RUN_MAGIC_NUMBER) {
 174             kern_return_t ret;
 175             user_data.user_data = 0;
 176
 177             ret = task_suspend (mach_task_self_);
 178             if (ret != KERN_SUCCESS) {
 179                 while(1) (void)task_terminate(mach_task_self_);
 180             }
 181         }
 182 #undef MACH_GDB_RUN_MAGIC_NUMBER
 183 #endif /* MACH_GDB_RUN_MAGIC_NUMBER */
 184         }
 185 #endif /* WE_REALLY_NEED_THIS_GDB_HACK */
 186
 187         /*
 188          * Reserve page 0 so that the program doesn't get it as
 189          * the result of a vm_allocate() or whatever.
 190          */
 191         {
 192                 vm_offset_t zero_page_start;
 193
 194                 zero_page_start = 0;
 195                 (void)vm_map(mach_task_self_, &zero_page_start, vm_page_size,
 196                              0, FALSE, MEMORY_OBJECT_NULL, 0, TRUE,
 197                              VM_PROT_NONE, VM_PROT_NONE, VM_INHERIT_COPY);
 198                 /* ignore result, we don't care if it failed */
 199         }
 200         return(0);
 201 }
 202
 203 int mach_init(void)
 204 {
 205         return(mach_init_doit(0));
 206 }
 207
 208 int     (*mach_init_routine)(void) = mach_init;
 209 int fork_mach_init()
 210 {
 211         /* called only from child */
 212         return(mach_init_doit(1));
 213 }
 214
 215 #undef  mach_task_self
 216
 217 mach_port_t
 218 mach_task_self()
 219 {
 220         return(task_self_trap());
 221 }
 222
 223 mach_port_t
 224 mach_thread_self()
 225 {
 226         return(thread_self_trap());
 227 }