glibc/hurd/hurdinit.c

/* Copyright (C) 1992, 1993, 1994, 1995, 1996 Free Software Foundation, Inc.
This file is part of the GNU C Library.

The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Library General Public License as
published by the Free Software Foundation; either version 2 of the
License, or (at your option) any later version.

The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
Library General Public License for more details.

You should have received a copy of the GNU Library General Public
License along with the GNU C Library; see the file COPYING.LIB.  If
not, write to the Free Software Foundation, Inc., 675 Mass Ave,
Cambridge, MA 02139, USA.  */

#include <sys/stat.h>
#include <stdlib.h>
#include <stdio.h>
#include <unistd.h>
#include <hurd.h>
#include <hurd/port.h>
#include "set-hooks.h"
#include "hurdmalloc.h"		/* XXX */


int _hurd_exec_flags;
struct hurd_port *_hurd_ports;
unsigned int _hurd_nports;
mode_t _hurd_umask;
sigset_t _hurdsig_traced;

error_t
_hurd_ports_use (int which, error_t (*operate) (mach_port_t))
{
  return HURD_PORT_USE (&_hurd_ports[which], (*operate) (port));
}

void _hurd_proc_init (char **argv);

DEFINE_HOOK (_hurd_subinit, (void));

/* Initialize the library data structures from the
   ints and ports passed to us by the exec server.

   PORTARRAY and INTARRAY are vm_deallocate'd.  */

void
_hurd_init (int flags, char **argv,
	    mach_port_t *portarray, size_t portarraysize,
	    int *intarray, size_t intarraysize)
{
  size_t i;

  _hurd_exec_flags = flags;

  _hurd_ports = malloc (portarraysize * sizeof (*_hurd_ports));
  if (_hurd_ports == NULL)
    __libc_fatal ("Can't allocate _hurd_ports\n");
  _hurd_nports = portarraysize;

  /* See what ports we were passed.  */
  for (i = 0; i < portarraysize; ++i)
    _hurd_port_init (&_hurd_ports[i], portarray[i]);

  /* When the user asks for the bootstrap port,
     he will get the one the exec server passed us.  */
  __task_set_special_port (__mach_task_self (), TASK_BOOTSTRAP_PORT,
			   portarray[INIT_PORT_BOOTSTRAP]);

  if (intarraysize > INIT_UMASK)
    _hurd_umask = intarray[INIT_UMASK] & 0777;
  else
    _hurd_umask = CMASK;

  if (intarraysize > INIT_TRACEMASK)
    _hurdsig_traced = intarray[INIT_TRACEMASK];

  /* Tell the proc server we exist, if it does.  */
  if (portarray[INIT_PORT_PROC] != MACH_PORT_NULL)
    _hurd_proc_init (argv);

  /* All done with init ints and ports.  */
  __vm_deallocate (__mach_task_self (),
		   (vm_address_t) intarray,
		   intarraysize * sizeof (int));
  __vm_deallocate (__mach_task_self (),
		   (vm_address_t) portarray,
		   portarraysize * sizeof (mach_port_t));

  if (flags & EXEC_SECURE)
    /* XXX if secure exec, elide environment variables
       which the library uses and could be security holes.
       CORESERVER, COREFILE
       */ ;

  /* Call other things which want to do some initialization.  These are not
     on the __libc_subinit hook because things there like to be able to
     assume the availability of the POSIX.1 services we provide.  */
  RUN_HOOK (_hurd_subinit, ());
}

#include <hurd/signal.h>

/* The user can do "int _hide_arguments = 1;" to make
   sure the arguments are never visible with `ps'.  */
int _hide_arguments, _hide_environment;

/* Hook for things which should be initialized as soon as the proc
   server is available.  */
DEFINE_HOOK (_hurd_proc_subinit, (void));

/* Do startup handshaking with the proc server just installed in _hurd_ports.
   Call _hurdsig_init to set up signal processing.  */

void
_hurd_proc_init (char **argv)
{
  mach_port_t oldmsg;
  struct hurd_userlink ulink;
  process_t procserver;

  /* Initialize the signal code; Mach exceptions will become signals.  */
  _hurdsig_init ();

  /* The signal thread is now prepared to receive messages.
     It is safe to give the port to the proc server.  */

  procserver = _hurd_port_get (&_hurd_ports[INIT_PORT_PROC], &ulink);

  /* Give the proc server our message port.  */
  __proc_setmsgport (procserver, _hurd_msgport, &oldmsg);
  if (oldmsg != MACH_PORT_NULL)
    /* Deallocate the old msg port we replaced.  */
    __mach_port_deallocate (__mach_task_self (), oldmsg);

  /* Tell the proc server where our args and environment are.  */
  __proc_set_arg_locations (procserver,
			    _hide_arguments ? 0 : (vm_address_t) argv,
			    _hide_environment ? 0 : (vm_address_t) __environ);

  _hurd_port_free (&_hurd_ports[INIT_PORT_PROC], &ulink, procserver);

  /* Initialize proc server-assisted fault recovery for the signal thread.  */
  _hurdsig_fault_init ();

  /* Call other things which want to do some initialization.  These are not
     on the _hurd_subinit hook because things there assume that things done
     here, like _hurd_pid, are already initialized.  */
  RUN_HOOK (_hurd_proc_subinit, ());

  if (_hurdsig_traced)
    /* This process is "traced", meaning it should stop on signals or exec.
       We are all set up now to handle signals.  Stop ourselves, to inform
       our parent (presumably a debugger) that the exec has completed.  */
    __msg_sig_post (_hurd_msgport, SIGTRAP, 0, __mach_task_self ());
}

/* Called when we get a message telling us to change our proc server port.  */

error_t
_hurd_setproc (process_t procserver)
{
  error_t err;
  mach_port_t oldmsg;

  /* Give the proc server our message port.  */
  if (err = __proc_setmsgport (procserver, _hurd_msgport, &oldmsg))
    return err;
  if (oldmsg != MACH_PORT_NULL)
    /* Deallocate the old msg port we replaced.  */
    __mach_port_deallocate (__mach_task_self (), oldmsg);

  /* Tell the proc server where our args and environment are.  */
  if (err = __proc_set_arg_locations (procserver,
				      /* We don't know the ARGV location.  */
				      (vm_address_t) 0,
				      _hide_environment ? 0 :
				      (vm_address_t) __environ))
    return err;

  /* Those calls worked, so the port looks good.  */
  _hurd_port_set (&_hurd_ports[INIT_PORT_PROC], procserver);

  {
    pid_t oldpgrp = _hurd_pgrp;

    /* Call these functions again so they can fetch the
       new information from the new proc server.  */
    RUN_HOOK (_hurd_proc_subinit, ());

    if (_hurd_pgrp != oldpgrp)
      {
	/* Run things that want notification of a pgrp change.  */
	DECLARE_HOOK (_hurd_pgrp_changed_hook, (pid_t));
	RUN_HOOK (_hurd_pgrp_changed_hook, (_hurd_pgrp));
      }
  }

  return 0;
}

/* Map the page at address zero with no access allowed, so
   dereferencing NULL will fault and no "anywhere" allocations
   (e.g. the out of line memory containing the argument strings)
   can be assigned address zero, which C says is not a valid pointer.

   When dynamically linked, this should be done by the dynamic linker
   before we run, but failing is harmless and we ignore the error.  */

static void map0 (void) __attribute__ ((unused));
text_set_element (_hurd_preinit_hook, map0);

static void
map0 (void)
{
  vm_address_t addr = 0;
  __vm_map (__mach_task_self (),
	    &addr, __vm_page_size, 0, 0, MACH_PORT_NULL, 0, 1,
	    VM_PROT_NONE, VM_PROT_NONE, VM_INHERIT_COPY);
}