mach.subproj/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 kern_return_t   _host_semaphore_traps_return_ = KERN_SUCCESS;
  59
  60 vm_size_t       vm_page_size;
  61
  62 /*
  63  * Forward internal declarations for automatic mach_init during
  64  * fork() implementation.
  65  */
  66 /* fork() calls through atfork_child_routine */
  67 void (*_atfork_child_routine)(void);
  68
  69 static void mach_atfork_child_routine(void);
  70 static boolean_t first = TRUE;
  71 static void (*previous_atfork_child_routine)(void);
  72 extern int mach_init(void);
  73 extern void _pthread_set_self(void *);
  74 extern void cthread_set_self(void *);
  75
  76
  77 static void mach_atfork_child_routine(void)
  78 {
  79         /*
  80          * If an (*_atfork_child_routine)() was registered when
  81          * mach_init was first called, then call that routine
  82          * prior to performing our re-initialization. This ensures
  83          * that the post-fork handlers are called in exactly the
  84          * same order as the crt0 (exec) handlers. Any library
  85          * that makes use of the _atfork_child_routine must follow
  86          * the same technique.
  87          */
  88         if (previous_atfork_child_routine) {
  89                 (*previous_atfork_child_routine)();
  90         }
  91         mach_init();
  92 }
  93
  94 mach_port_t
  95 mach_host_self()
  96 {
  97         return(host_self_trap());
  98 }
  99
 100 int mach_init_doit(int forkchild)
 101 {
 102         mach_msg_type_number_t host_info_size = 0;
 103
 104         /*
 105          *      Get the important ports into the cached values,
 106          *      as required by "mach_init.h".
 107          */
 108
 109         mach_task_self_ = task_self_trap();
 110         mach_host_self_ = host_self_trap();
 111
 112
 113         if (!forkchild) {
 114                 /*
 115                  * Set up the post-fork child handler in the libc stub
 116                  * to invoke this routine if this process forks. Save the
 117                  * previous value in order that we can call that handler
 118                  * prior to performing our postfork work.
 119                  */
 120
 121                 first = FALSE;
 122                 previous_atfork_child_routine = _atfork_child_routine;
 123                 _atfork_child_routine = mach_atfork_child_routine;
 124                 _pthread_set_self(0);
 125                 cthread_set_self(0);
 126         }
 127
 128         /*
 129          *      Initialize the single mig reply port
 130          */
 131
 132         mig_init(0);
 133
 134         /*
 135          *      Cache some other valuable system constants
 136          */
 137         _host_semaphore_traps_return_ = host_info(mach_host_self_,
 138                                            HOST_SEMAPHORE_TRAPS,
 139                                            0,
 140                                            &host_info_size);
 141
 142         (void)host_page_size(mach_host_self_, &vm_page_size);
 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 }