hurd/hurdinit.c

   1 /* Copyright (C) 1992-2020 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 Lesser General Public
   6    License as published by the Free Software Foundation; either
   7    version 2.1 of the 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    Lesser General Public License for more details.
  13
  14    You should have received a copy of the GNU Lesser General Public
  15    License along with the GNU C Library; if not, see
  16    <https://www.gnu.org/licenses/>.  */
  17
  18 #include <sys/stat.h>
  19 #include <stdlib.h>
  20 #include <stdio.h>
  21 #include <unistd.h>
  22 #include <hurd.h>
  23 #include <hurd/port.h>
  24 #include "set-hooks.h"
  25 #include "hurdmalloc.h"         /* XXX */
  26
  27
  28 int _hurd_exec_flags;
  29 struct hurd_port *_hurd_ports;
  30 unsigned int _hurd_nports;
  31 mode_t _hurd_umask;
  32 sigset_t _hurdsig_traced;
  33
  34 char **__libc_argv;
  35 int __libc_argc;
  36
  37
  38 error_t
  39 _hurd_ports_use (int which, error_t (*operate) (mach_port_t))
  40 {
  41   if (__glibc_unlikely (_hurd_ports == NULL))
  42     /* This means that _hurd_init has not been called yet, which is
  43        normally only the case in the bootstrap filesystem, and there
  44        only in the early phases of booting.  */
  45     return EGRATUITOUS;
  46
  47   return HURD_PORT_USE (&_hurd_ports[which], (*operate) (port));
  48 }
  49
  50 DEFINE_HOOK (_hurd_subinit, (void));
  51
  52 __typeof (_hurd_proc_init) _hurd_new_proc_init; /* below */
  53
  54 /* Initialize the library data structures from the
  55    ints and ports passed to us by the exec server.
  56
  57    PORTARRAY and INTARRAY are vm_deallocate'd.  */
  58
  59 void
  60 _hurd_init (int flags, char **argv,
  61             mach_port_t *portarray, size_t portarraysize,
  62             int *intarray, size_t intarraysize)
  63 {
  64   size_t i;
  65
  66   _hurd_exec_flags = flags;
  67
  68   _hurd_ports = malloc (portarraysize * sizeof (*_hurd_ports));
  69   if (_hurd_ports == NULL)
  70     __libc_fatal ("Can't allocate _hurd_ports\n");
  71   _hurd_nports = portarraysize;
  72
  73   /* See what ports we were passed.  */
  74   for (i = 0; i < portarraysize; ++i)
  75     _hurd_port_init (&_hurd_ports[i], portarray[i]);
  76
  77   /* When the user asks for the bootstrap port,
  78      he will get the one the exec server passed us.  */
  79   __task_set_special_port (__mach_task_self (), TASK_BOOTSTRAP_PORT,
  80                            portarray[INIT_PORT_BOOTSTRAP]);
  81
  82   if (intarraysize > INIT_UMASK)
  83     _hurd_umask = intarray[INIT_UMASK] & 0777;
  84   else
  85     _hurd_umask = CMASK;
  86
  87   if (intarraysize > INIT_TRACEMASK)
  88     _hurdsig_traced = intarray[INIT_TRACEMASK];
  89
  90   /* Tell the proc server we exist, if it does.  */
  91   if (portarray[INIT_PORT_PROC] != MACH_PORT_NULL)
  92     _hurd_new_proc_init (argv, intarray, intarraysize);
  93
  94   /* All done with init ints and ports.  */
  95   __vm_deallocate (__mach_task_self (),
  96                    (vm_address_t) intarray,
  97                    intarraysize * sizeof (int));
  98   __vm_deallocate (__mach_task_self (),
  99                    (vm_address_t) portarray,
 100                    portarraysize * sizeof (mach_port_t));
 101
 102   if (flags & EXEC_SECURE)
 103     {
 104       /* XXX if secure exec, elide environment variables
 105          which the library uses and could be security holes.
 106          CORESERVER, COREFILE
 107       */
 108     }
 109
 110   /* Call other things which want to do some initialization.  These are not
 111      on the __libc_subinit hook because things there like to be able to
 112      assume the availability of the POSIX.1 services we provide.  */
 113   RUN_HOOK (_hurd_subinit, ());
 114 }
 115 libc_hidden_def (_hurd_init)
 116 \f
 117 #include <hurd/signal.h>
 118
 119 /* The user can do "int _hide_arguments = 1;" to make
 120    sure the arguments are never visible with `ps'.  */
 121 int _hide_arguments, _hide_environment;
 122
 123 /* Hook for things which should be initialized as soon as the proc
 124    server is available.  */
 125 DEFINE_HOOK (_hurd_proc_subinit, (void));
 126
 127 /* Do startup handshaking with the proc server just installed in _hurd_ports.
 128    Call _hurdsig_init to set up signal processing.  */
 129
 130 void
 131 _hurd_new_proc_init (char **argv,
 132                      const int *intarray, size_t intarraysize)
 133 {
 134   mach_port_t oldmsg;
 135   struct hurd_userlink ulink;
 136   process_t procserver;
 137
 138   /* Initialize the signal code; Mach exceptions will become signals.  */
 139   _hurdsig_init (intarray, intarraysize);
 140
 141   /* The signal thread is now prepared to receive messages.
 142      It is safe to give the port to the proc server.  */
 143
 144   procserver = _hurd_port_get (&_hurd_ports[INIT_PORT_PROC], &ulink);
 145
 146   /* Give the proc server our message port.  */
 147   __proc_setmsgport (procserver, _hurd_msgport, &oldmsg);
 148   if (oldmsg != MACH_PORT_NULL)
 149     /* Deallocate the old msg port we replaced.  */
 150     __mach_port_deallocate (__mach_task_self (), oldmsg);
 151
 152   /* Tell the proc server where our args and environment are.  */
 153   __proc_set_arg_locations (procserver,
 154                             _hide_arguments ? 0 : (vm_address_t) argv,
 155                             _hide_environment ? 0 : (vm_address_t) __environ);
 156
 157   _hurd_port_free (&_hurd_ports[INIT_PORT_PROC], &ulink, procserver);
 158
 159   /* Initialize proc server-assisted fault recovery for the signal thread.  */
 160   _hurdsig_fault_init ();
 161
 162   /* Call other things which want to do some initialization.  These are not
 163      on the _hurd_subinit hook because things there assume that things done
 164      here, like _hurd_pid, are already initialized.  */
 165   RUN_HOOK (_hurd_proc_subinit, ());
 166
 167   /* XXX This code should probably be removed entirely at some point.  This
 168      conditional should make it reasonably usable with old gdb's for a
 169      while.  Eventually it probably makes most sense for the exec server to
 170      mask out EXEC_SIGTRAP so the debugged program is closer to not being
 171      able to tell it's being debugged.  */
 172   if (!__sigisemptyset (&_hurdsig_traced)
 173 #ifdef EXEC_SIGTRAP
 174       && !(_hurd_exec_flags & EXEC_SIGTRAP)
 175 #endif
 176       )
 177     /* This process is "traced", meaning it should stop on signals or exec.
 178        We are all set up now to handle signals.  Stop ourselves, to inform
 179        our parent (presumably a debugger) that the exec has completed.  */
 180     __msg_sig_post (_hurd_msgport, SIGTRAP, 0, __mach_task_self ());
 181 }
 182
 183 #include <shlib-compat.h>
 184 versioned_symbol (libc, _hurd_new_proc_init, _hurd_proc_init, GLIBC_2_1);
 185 \f
 186 /* Called when we get a message telling us to change our proc server port.  */
 187
 188 error_t
 189 _hurd_setproc (process_t procserver)
 190 {
 191   error_t err;
 192   mach_port_t oldmsg;
 193
 194   /* Give the proc server our message port.  */
 195   if (err = __proc_setmsgport (procserver, _hurd_msgport, &oldmsg))
 196     return err;
 197   if (oldmsg != MACH_PORT_NULL)
 198     /* Deallocate the old msg port we replaced.  */
 199     __mach_port_deallocate (__mach_task_self (), oldmsg);
 200
 201   /* Tell the proc server where our args and environment are.  */
 202   if (err = __proc_set_arg_locations (procserver,
 203                                       _hide_arguments ? 0
 204                                       : (vm_address_t) __libc_argv,
 205                                       _hide_environment ? 0
 206                                       : (vm_address_t) __environ))
 207     return err;
 208
 209   /* Those calls worked, so the port looks good.  */
 210   _hurd_port_set (&_hurd_ports[INIT_PORT_PROC], procserver);
 211
 212   {
 213     pid_t oldpgrp = _hurd_pgrp;
 214
 215     /* Call these functions again so they can fetch the
 216        new information from the new proc server.  */
 217     RUN_HOOK (_hurd_proc_subinit, ());
 218
 219     if (_hurd_pgrp != oldpgrp)
 220       {
 221         /* Run things that want notification of a pgrp change.  */
 222         DECLARE_HOOK (_hurd_pgrp_changed_hook, (pid_t));
 223         RUN_HOOK (_hurd_pgrp_changed_hook, (_hurd_pgrp));
 224       }
 225   }
 226
 227   return 0;
 228 }