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 vm_size_t       vm_page_mask;
  64 int             vm_page_shift;
  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 static boolean_t mach_init_inited = FALSE;
  77 extern int mach_init(void);
  78 extern void _pthread_set_self(void *);
  79 extern void cthread_set_self(void *);
  80 extern void other_libc_init(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_inited = FALSE;
  98         mach_init();
  99 }
 100
 101 mach_port_t
 102 mach_host_self()
 103 {
 104         return(host_self_trap());
 105 }
 106
 107 int mach_init_doit(int forkchild)
 108 {
 109         host_t host;
 110
 111         /*
 112          *      Get the important ports into the cached values,
 113          *      as required by "mach_init.h".
 114          */
 115
 116         mach_task_self_ = task_self_trap();
 117         host = host_self_trap();
 118
 119
 120         if (!forkchild) {
 121                 /*
 122                  * Set up the post-fork child handler in the libc stub
 123                  * to invoke this routine if this process forks. Save the
 124                  * previous value in order that we can call that handler
 125                  * prior to performing our postfork work.
 126                  */
 127
 128                 first = FALSE;
 129                 previous_atfork_child_routine = _atfork_child_routine;
 130                 _atfork_child_routine = mach_atfork_child_routine;
 131                 _pthread_set_self(0);
 132                 cthread_set_self(0);
 133         }
 134
 135         /*
 136          *      Initialize the single mig reply port
 137          */
 138
 139         mig_init(0);
 140
 141         /*
 142          *      Cache some other valuable system constants
 143          */
 144
 145 #if defined(__ppc64__) /* NGK hack for now */
 146         vm_page_size = 4096;
 147 #else
 148         (void)host_page_size(host, &vm_page_size);
 149 #endif
 150         vm_page_mask = vm_page_size - 1;
 151         if (vm_page_size == 0) {
 152                 /* guard against unlikely craziness */
 153                 vm_page_shift = 0;
 154         } else {
 155                 /*
 156                  * Unfortunately there's no kernel interface to get the
 157                  * vm_page_shift, but it's easy enough to calculate.
 158                  */
 159                 for (vm_page_shift = 0;
 160                      (vm_page_size & (1 << vm_page_shift)) == 0;
 161                      vm_page_shift++)
 162                         continue;
 163         }
 164
 165         mach_port_deallocate(mach_task_self_, host);
 166
 167         mach_init_ports();
 168
 169 #if WE_REALLY_NEED_THIS_GDB_HACK
 170         /*
 171          * Check to see if GDB wants us to stop
 172          */
 173         {
 174           task_user_data_data_t user_data;
 175           mach_msg_type_number_t        user_data_count = TASK_USER_DATA_COUNT;
 176
 177         user_data.user_data = 0;
 178         (void)task_info(mach_task_self_, TASK_USER_DATA,
 179                 (task_info_t)&user_data, &user_data_count);
 180 #define MACH_GDB_RUN_MAGIC_NUMBER 1
 181 #ifdef  MACH_GDB_RUN_MAGIC_NUMBER
 182           /* This magic number is set in mach-aware gdb
 183            *  for RUN command to allow us to suspend user's
 184            *  executable (linked with this libmach!)
 185            *  with the code below.
 186         * This hack should disappear when gdb improves.
 187         */
 188         if ((int)user_data.user_data == MACH_GDB_RUN_MAGIC_NUMBER) {
 189             kern_return_t ret;
 190             user_data.user_data = 0;
 191
 192             ret = task_suspend (mach_task_self_);
 193             if (ret != KERN_SUCCESS) {
 194                 while(1) (void)task_terminate(mach_task_self_);
 195             }
 196         }
 197 #undef MACH_GDB_RUN_MAGIC_NUMBER
 198 #endif /* MACH_GDB_RUN_MAGIC_NUMBER */
 199         }
 200 #endif /* WE_REALLY_NEED_THIS_GDB_HACK */
 201
 202         /*
 203          * Reserve page 0 so that the program doesn't get it as
 204          * the result of a vm_allocate() or whatever.
 205          */
 206         {
 207                 vm_offset_t zero_page_start;
 208
 209                 zero_page_start = 0;
 210                 (void)vm_map(mach_task_self_, &zero_page_start, vm_page_size,
 211                              0, FALSE, MEMORY_OBJECT_NULL, 0, TRUE,
 212                              VM_PROT_NONE, VM_PROT_NONE, VM_INHERIT_COPY);
 213                 /* ignore result, we don't care if it failed */
 214         }
 215
 216         return(0);
 217 }
 218
 219 #ifdef __DYNAMIC__
 220 /* libc_initializer is the dyld initializer for libc (3760827) */
 221 static void libc_initializer() __attribute__((constructor));
 222 static void
 223 libc_initializer()
 224 {
 225         mach_init();
 226 }
 227 #endif /* __DYNAMIC__ */
 228
 229 /* mach_init may get called from the initializer and from crt.c, but only
 230  * call mach_init_doit() once */
 231 int mach_init(void)
 232 {
 233         int ret;
 234
 235         if (mach_init_inited)
 236                 return(0);
 237         mach_init_inited = TRUE;
 238         ret = mach_init_doit(0);
 239
 240         /* Do other Libc initialization */
 241         other_libc_init();
 242
 243         return ret;
 244 }
 245
 246 int     (*mach_init_routine)(void) = mach_init;
 247 int fork_mach_init()
 248 {
 249         /* called only from child */
 250         return(mach_init_doit(1));
 251 }
 252
 253 #undef  mach_task_self
 254
 255 mach_port_t
 256 mach_task_self()
 257 {
 258         return(task_self_trap());
 259 }
 260
 261 mach_port_t
 262 mach_thread_self()
 263 {
 264         return(thread_self_trap());
 265 }