hurd/hurdinit.c

   1 /* Copyright (C) 1992, 1993, 1994, 1995, 1996 Free Software Foundation, Inc.
   2 This file is part of the GNU C Library.
   3
   4 The GNU C Library is free software; you can redistribute it and/or
   5 modify it under the terms of the GNU Library General Public License as
   6 published by the Free Software Foundation; either version 2 of the
   7 License, or (at your option) any later version.
   8
   9 The GNU C Library is distributed in the hope that it will be useful,
  10 but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12 Library General Public License for more details.
  13
  14 You should have received a copy of the GNU Library General Public
  15 License along with the GNU C Library; see the file COPYING.LIB.  If
  16 not, write to the Free Software Foundation, Inc., 675 Mass Ave,
  17 Cambridge, MA 02139, USA.  */
  18
  19 #include <sys/stat.h>
  20 #include <stdlib.h>
  21 #include <stdio.h>
  22 #include <unistd.h>
  23 #include <hurd.h>
  24 #include <hurd/port.h>
  25 #include "set-hooks.h"
  26 #include "hurdmalloc.h"         /* XXX */
  27
  28
  29 int _hurd_exec_flags;
  30 struct hurd_port *_hurd_ports;
  31 unsigned int _hurd_nports;
  32 mode_t _hurd_umask;
  33 sigset_t _hurdsig_traced;
  34
  35 error_t
  36 _hurd_ports_use (int which, error_t (*operate) (mach_port_t))
  37 {
  38   return HURD_PORT_USE (&_hurd_ports[which], (*operate) (port));
  39 }
  40
  41 void _hurd_proc_init (char **argv);
  42
  43 DEFINE_HOOK (_hurd_subinit, (void));
  44
  45 /* Initialize the library data structures from the
  46    ints and ports passed to us by the exec server.
  47
  48    PORTARRAY and INTARRAY are vm_deallocate'd.  */
  49
  50 void
  51 _hurd_init (int flags, char **argv,
  52             mach_port_t *portarray, size_t portarraysize,
  53             int *intarray, size_t intarraysize)
  54 {
  55   size_t i;
  56
  57   _hurd_exec_flags = flags;
  58
  59   _hurd_ports = malloc (portarraysize * sizeof (*_hurd_ports));
  60   if (_hurd_ports == NULL)
  61     __libc_fatal ("Can't allocate _hurd_ports\n");
  62   _hurd_nports = portarraysize;
  63
  64   /* See what ports we were passed.  */
  65   for (i = 0; i < portarraysize; ++i)
  66     _hurd_port_init (&_hurd_ports[i], portarray[i]);
  67
  68   /* When the user asks for the bootstrap port,
  69      he will get the one the exec server passed us.  */
  70   __task_set_special_port (__mach_task_self (), TASK_BOOTSTRAP_PORT,
  71                            portarray[INIT_PORT_BOOTSTRAP]);
  72
  73   if (intarraysize > INIT_UMASK)
  74     _hurd_umask = intarray[INIT_UMASK] & 0777;
  75   else
  76     _hurd_umask = CMASK;
  77
  78   if (intarraysize > INIT_TRACEMASK)
  79     _hurdsig_traced = intarray[INIT_TRACEMASK];
  80
  81   /* Tell the proc server we exist, if it does.  */
  82   if (portarray[INIT_PORT_PROC] != MACH_PORT_NULL)
  83     _hurd_proc_init (argv);
  84
  85   /* All done with init ints and ports.  */
  86   __vm_deallocate (__mach_task_self (),
  87                    (vm_address_t) intarray,
  88                    intarraysize * sizeof (int));
  89   __vm_deallocate (__mach_task_self (),
  90                    (vm_address_t) portarray,
  91                    portarraysize * sizeof (mach_port_t));
  92
  93   if (flags & EXEC_SECURE)
  94     /* XXX if secure exec, elide environment variables
  95        which the library uses and could be security holes.
  96        CORESERVER, COREFILE
  97        */ ;
  98
  99   /* Call other things which want to do some initialization.  These are not
 100      on the __libc_subinit hook because things there like to be able to
 101      assume the availability of the POSIX.1 services we provide.  */
 102   RUN_HOOK (_hurd_subinit, ());
 103 }
 104 \f
 105 #include <hurd/signal.h>
 106
 107 /* The user can do "int _hide_arguments = 1;" to make
 108    sure the arguments are never visible with `ps'.  */
 109 int _hide_arguments, _hide_environment;
 110
 111 /* Hook for things which should be initialized as soon as the proc
 112    server is available.  */
 113 DEFINE_HOOK (_hurd_proc_subinit, (void));
 114
 115 /* Do startup handshaking with the proc server just installed in _hurd_ports.
 116    Call _hurdsig_init to set up signal processing.  */
 117
 118 void
 119 _hurd_proc_init (char **argv)
 120 {
 121   mach_port_t oldmsg;
 122   struct hurd_userlink ulink;
 123   process_t procserver;
 124
 125   /* Initialize the signal code; Mach exceptions will become signals.  */
 126   _hurdsig_init ();
 127
 128   /* The signal thread is now prepared to receive messages.
 129      It is safe to give the port to the proc server.  */
 130
 131   procserver = _hurd_port_get (&_hurd_ports[INIT_PORT_PROC], &ulink);
 132
 133   /* Give the proc server our message port.  */
 134   __proc_setmsgport (procserver, _hurd_msgport, &oldmsg);
 135   if (oldmsg != MACH_PORT_NULL)
 136     /* Deallocate the old msg port we replaced.  */
 137     __mach_port_deallocate (__mach_task_self (), oldmsg);
 138
 139   /* Tell the proc server where our args and environment are.  */
 140   __proc_set_arg_locations (procserver,
 141                             _hide_arguments ? 0 : (vm_address_t) argv,
 142                             _hide_environment ? 0 : (vm_address_t) __environ);
 143
 144   _hurd_port_free (&_hurd_ports[INIT_PORT_PROC], &ulink, procserver);
 145
 146   /* Initialize proc server-assisted fault recovery for the signal thread.  */
 147   _hurdsig_fault_init ();
 148
 149   /* Call other things which want to do some initialization.  These are not
 150      on the _hurd_subinit hook because things there assume that things done
 151      here, like _hurd_pid, are already initialized.  */
 152   RUN_HOOK (_hurd_proc_subinit, ());
 153
 154   if (_hurdsig_traced)
 155     /* This process is "traced", meaning it should stop on signals or exec.
 156        We are all set up now to handle signals.  Stop ourselves, to inform
 157        our parent (presumably a debugger) that the exec has completed.  */
 158     __msg_sig_post (_hurd_msgport, SIGTRAP, 0, __mach_task_self ());
 159 }
 160 \f
 161 /* Called when we get a message telling us to change our proc server port.  */
 162
 163 error_t
 164 _hurd_setproc (process_t procserver)
 165 {
 166   error_t err;
 167   mach_port_t oldmsg;
 168   extern char **__libc_argv;
 169
 170   /* Give the proc server our message port.  */
 171   if (err = __proc_setmsgport (procserver, _hurd_msgport, &oldmsg))
 172     return err;
 173   if (oldmsg != MACH_PORT_NULL)
 174     /* Deallocate the old msg port we replaced.  */
 175     __mach_port_deallocate (__mach_task_self (), oldmsg);
 176
 177   /* Tell the proc server where our args and environment are.  */
 178   if (err = __proc_set_arg_locations (procserver,
 179                                       _hide_arguments ? 0 :
 180                                       (vm_address_t) __libc_argv,
 181                                       _hide_environment ? 0 :
 182                                       (vm_address_t) __environ))
 183     return err;
 184
 185   /* Those calls worked, so the port looks good.  */
 186   _hurd_port_set (&_hurd_ports[INIT_PORT_PROC], procserver);
 187
 188   {
 189     pid_t oldpgrp = _hurd_pgrp;
 190
 191     /* Call these functions again so they can fetch the
 192        new information from the new proc server.  */
 193     RUN_HOOK (_hurd_proc_subinit, ());
 194
 195     if (_hurd_pgrp != oldpgrp)
 196       {
 197         /* Run things that want notification of a pgrp change.  */
 198         DECLARE_HOOK (_hurd_pgrp_changed_hook, (pid_t));
 199         RUN_HOOK (_hurd_pgrp_changed_hook, (_hurd_pgrp));
 200       }
 201   }
 202
 203   return 0;
 204 }
 205 \f
 206 /* Map the page at address zero with no access allowed, so
 207    dereferencing NULL will fault and no "anywhere" allocations
 208    (e.g. the out of line memory containing the argument strings)
 209    can be assigned address zero, which C says is not a valid pointer.
 210
 211    When dynamically linked, this should be done by the dynamic linker
 212    before we run, but failing is harmless and we ignore the error.  */
 213
 214 static void map0 (void) __attribute__ ((unused));
 215 text_set_element (_hurd_preinit_hook, map0);
 216
 217 static void
 218 map0 (void)
 219 {
 220   vm_address_t addr = 0;
 221   __vm_map (__mach_task_self (),
 222             &addr, __vm_page_size, 0, 0, MACH_PORT_NULL, 0, 1,
 223             VM_PROT_NONE, VM_PROT_NONE, VM_INHERIT_COPY);
 224 }