xnu-2050.7.9.tar.gz

[apple/xnu.git] / libsyscall / mach / mach_init.c

/*
 * Copyright (c) 1999-2010 Apple Inc. All rights reserved.
 *
 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
 * 
 * This file contains Original Code and/or Modifications of Original Code
 * as defined in and that are subject to the Apple Public Source License
 * Version 2.0 (the 'License'). You may not use this file except in
 * compliance with the License. The rights granted to you under the License
 * may not be used to create, or enable the creation or redistribution of,
 * unlawful or unlicensed copies of an Apple operating system, or to
 * circumvent, violate, or enable the circumvention or violation of, any
 * terms of an Apple operating system software license agreement.
 * 
 * Please obtain a copy of the License at
 * http://www.opensource.apple.com/apsl/ and read it before using this file.
 * 
 * The Original Code and all software distributed under the License are
 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
 * Please see the License for the specific language governing rights and
 * limitations under the License.
 * 
 * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
 */
/* 
 * Mach Operating System
 * Copyright (c) 1991,1990,1989,1988,1987 Carnegie Mellon University
 * All Rights Reserved.
 * 
 * Permission to use, copy, modify and distribute this software and its
 * documentation is hereby granted, provided that both the copyright
 * notice and this permission notice appear in all copies of the
 * software, derivative works or modified versions, and any portions
 * thereof, and that both notices appear in supporting documentation.
 * 
 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
 * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
 * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
 * 
 * Carnegie Mellon requests users of this software to return to
 * 
 *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
 *  School of Computer Science
 *  Carnegie Mellon University
 *  Pittsburgh PA 15213-3890
 * 
 * any improvements or extensions that they make and grant Carnegie Mellon
 * the rights to redistribute these changes.
 */

#include <mach/mach.h>
#include <mach/boolean.h>
#include <mach/machine/ndr_def.h>
#include <mach/mach_traps.h>
#include <mach/mach_host.h>
#include <mach/mach_init.h>
#include <mach/vm_param.h>
#include <stdbool.h>
#include "externs.h"
#include "mig_reply_port.h"

mach_port_t	mach_task_self_ = MACH_PORT_NULL;
#ifdef __i386__
mach_port_t	mach_host_self_ = MACH_PORT_NULL;
#endif

vm_size_t vm_page_size	= PAGE_SIZE;
vm_size_t vm_page_mask	= PAGE_MASK;
int vm_page_shift		= PAGE_SHIFT;

int mach_init(void);
int _mach_fork_child(void);

static int mach_init_doit(bool forkchild);

extern void _pthread_set_self(void *);
extern void cthread_set_self(void *);

kern_return_t
host_page_size(__unused host_t host, vm_size_t *out_page_size)
{
	*out_page_size = PAGE_SIZE;
	return KERN_SUCCESS;
}

/* 
 * mach_init() must be called explicitly in static executables (including dyld).
 * called by libSystem_initializer() in dynamic executables
 */
int
mach_init(void)
{
	static bool mach_init_inited = false;

	if (mach_init_inited) {
		return 0;
	}
	mach_init_inited = true;
	
	return mach_init_doit(false);
}

// called by libSystem_atfork_child()
int
_mach_fork_child(void)
{
	return mach_init_doit(true);
}

int
mach_init_doit(bool forkchild)
{
	/*
	 *	Get the important ports into the cached values,
	 *	as required by "mach_init.h".
	 */
	mach_task_self_ = task_self_trap();
	
	/*
	 *	Initialize the single mig reply port
	 */

	_pthread_set_self(0);
	_mig_init(0);

#if WE_REALLY_NEED_THIS_GDB_HACK
	/*
	 * Check to see if GDB wants us to stop
	 */
	{
	task_user_data_data_t	user_data;
	mach_msg_type_number_t	user_data_count = TASK_USER_DATA_COUNT;
	  
	user_data.user_data = 0;
	(void)task_info(mach_task_self_, TASK_USER_DATA,
		(task_info_t)&user_data, &user_data_count);
#define MACH_GDB_RUN_MAGIC_NUMBER 1
#ifdef	MACH_GDB_RUN_MAGIC_NUMBER	
	/* This magic number is set in mach-aware gdb 
	 *  for RUN command to allow us to suspend user's
	 *  executable (linked with this libmach!) 
	 *  with the code below.
	 * This hack should disappear when gdb improves.
	 */
	if ((int)user_data.user_data == MACH_GDB_RUN_MAGIC_NUMBER) {
	    kern_return_t ret;
	    user_data.user_data = 0;
	    
	    ret = task_suspend(mach_task_self_);
	    if (ret != KERN_SUCCESS) {
			while (1) {
				(void)task_terminate(mach_task_self_);
			}
	    }
	}
#undef MACH_GDB_RUN_MAGIC_NUMBER  
#endif /* MACH_GDB_RUN_MAGIC_NUMBER */
	}
#endif /* WE_REALLY_NEED_THIS_GDB_HACK */

	return 0;
}