1 /* Copyright (C) 1992-2022 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 <ldsodefs.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 char **__libc_argv;
36 int __libc_argc;
37 
38 static int *_hurd_intarray;
39 static size_t _hurd_intarraysize;
40 static mach_port_t *_hurd_portarray;
41 static size_t _hurd_portarraysize;
42 
43 error_t
_hurd_ports_use(int which,error_t (* operate)(mach_port_t))44 _hurd_ports_use (int which, error_t (*operate) (mach_port_t))
45 {
46   if (__glibc_unlikely (_hurd_ports == NULL))
47     /* This means that _hurd_init has not been called yet, which is
48        normally only the case in the bootstrap filesystem, and there
49        only in the early phases of booting.  */
50     return EGRATUITOUS;
51 
52   return HURD_PORT_USE (&_hurd_ports[which], (*operate) (port));
53 }
54 
55 DEFINE_HOOK (_hurd_subinit, (void));
56 
57 __typeof (_hurd_proc_init) _hurd_new_proc_init;	/* below */
58 
59 /* Initialize the library data structures from the
60    ints and ports passed to us by the exec server.
61 
62    PORTARRAY and INTARRAY are vm_deallocate'd.  */
63 
64 void
_hurd_init(int flags,char ** argv,mach_port_t * portarray,size_t portarraysize,int * intarray,size_t intarraysize)65 _hurd_init (int flags, char **argv,
66 	    mach_port_t *portarray, size_t portarraysize,
67 	    int *intarray, size_t intarraysize)
68 {
69   size_t i;
70 
71   _hurd_exec_flags = flags;
72 
73   _hurd_ports = malloc (portarraysize * sizeof (*_hurd_ports));
74   if (_hurd_ports == NULL)
75     __libc_fatal ("Can't allocate _hurd_ports\n");
76   _hurd_nports = portarraysize;
77 
78   /* See what ports we were passed.  */
79   for (i = 0; i < portarraysize; ++i)
80     _hurd_port_init (&_hurd_ports[i], portarray[i]);
81 
82   /* When the user asks for the bootstrap port,
83      he will get the one the exec server passed us.  */
84   __task_set_special_port (__mach_task_self (), TASK_BOOTSTRAP_PORT,
85 			   portarray[INIT_PORT_BOOTSTRAP]);
86 
87   if (intarraysize > INIT_UMASK)
88     _hurd_umask = intarray[INIT_UMASK] & 0777;
89   else
90     _hurd_umask = CMASK;
91 
92   if (intarraysize > INIT_TRACEMASK)
93     _hurdsig_traced = intarray[INIT_TRACEMASK];
94 
95   _hurd_intarray = intarray;
96   _hurd_intarraysize = intarraysize;
97   _hurd_portarray = portarray;
98   _hurd_portarraysize = portarraysize;
99 
100   if (flags & EXEC_SECURE)
101     {
102       /* XXX if secure exec, elide environment variables
103 	 which the library uses and could be security holes.
104 	 CORESERVER, COREFILE
105       */
106     }
107 
108   /* Call other things which want to do some initialization.  These are not
109      on the __libc_subinit hook because things there like to be able to
110      assume the availability of the POSIX.1 services we provide.  */
111   RUN_RELHOOK (_hurd_subinit, ());
112 }
libc_hidden_def(_hurd_init)113 libc_hidden_def (_hurd_init)
114 
115 void
116 _hurd_libc_proc_init (char **argv)
117 {
118   if (_hurd_portarray)
119     {
120       /* We will start the signal thread, so we need to initialize libpthread
121        * if linked in.  */
122       if (__pthread_initialize_minimal != NULL)
123 	__pthread_initialize_minimal ();
124 
125       /* Tell the proc server we exist, if it does.  */
126       if (_hurd_portarray[INIT_PORT_PROC] != MACH_PORT_NULL)
127 	_hurd_new_proc_init (argv, _hurd_intarray, _hurd_intarraysize);
128 
129       /* All done with init ints and ports.  */
130       __vm_deallocate (__mach_task_self (),
131 		       (vm_address_t) _hurd_intarray,
132 		       _hurd_intarraysize * sizeof (int));
133       _hurd_intarray = NULL;
134       _hurd_intarraysize = 0;
135 
136       __vm_deallocate (__mach_task_self (),
137 		       (vm_address_t) _hurd_portarray,
138 		       _hurd_portarraysize * sizeof (mach_port_t));
139       _hurd_portarray = NULL;
140       _hurd_portarraysize = 0;
141     }
142 }
143 libc_hidden_def (_hurd_libc_proc_init)
144 
145 #include <hurd/signal.h>
146 
147 /* The user can do "int _hide_arguments = 1;" to make
148    sure the arguments are never visible with `ps'.  */
149 int _hide_arguments, _hide_environment;
150 
151 /* Hook for things which should be initialized as soon as the proc
152    server is available.  */
153 DEFINE_HOOK (_hurd_proc_subinit, (void));
154 
155 /* Do startup handshaking with the proc server just installed in _hurd_ports.
156    Call _hurdsig_init to set up signal processing.  */
157 
158 void
_hurd_new_proc_init(char ** argv,const int * intarray,size_t intarraysize)159 _hurd_new_proc_init (char **argv,
160 		     const int *intarray, size_t intarraysize)
161 {
162   mach_port_t oldmsg;
163   struct hurd_userlink ulink;
164   process_t procserver;
165 
166   /* Initialize the signal code; Mach exceptions will become signals.  */
167   _hurdsig_init (intarray, intarraysize);
168 
169   /* The signal thread is now prepared to receive messages.
170      It is safe to give the port to the proc server.  */
171 
172   procserver = _hurd_port_get (&_hurd_ports[INIT_PORT_PROC], &ulink);
173 
174   /* Give the proc server our message port.  */
175   __proc_setmsgport (procserver, _hurd_msgport, &oldmsg);
176   if (oldmsg != MACH_PORT_NULL)
177     /* Deallocate the old msg port we replaced.  */
178     __mach_port_deallocate (__mach_task_self (), oldmsg);
179 
180   /* Tell the proc server where our args and environment are.  */
181   __proc_set_arg_locations (procserver,
182 			    _hide_arguments ? 0 : (vm_address_t) argv,
183 			    _hide_environment ? 0 : (vm_address_t) __environ);
184 
185   _hurd_port_free (&_hurd_ports[INIT_PORT_PROC], &ulink, procserver);
186 
187   /* Initialize proc server-assisted fault recovery for the signal thread.  */
188   _hurdsig_fault_init ();
189 
190   /* Call other things which want to do some initialization.  These are not
191      on the _hurd_subinit hook because things there assume that things done
192      here, like _hurd_pid, are already initialized.  */
193   RUN_RELHOOK (_hurd_proc_subinit, ());
194 
195   /* XXX This code should probably be removed entirely at some point.  This
196      conditional should make it reasonably usable with old gdb's for a
197      while.  Eventually it probably makes most sense for the exec server to
198      mask out EXEC_SIGTRAP so the debugged program is closer to not being
199      able to tell it's being debugged.  */
200   if (!__sigisemptyset (&_hurdsig_traced)
201 #ifdef EXEC_SIGTRAP
202       && !(_hurd_exec_flags & EXEC_SIGTRAP)
203 #endif
204       )
205     /* This process is "traced", meaning it should stop on signals or exec.
206        We are all set up now to handle signals.  Stop ourselves, to inform
207        our parent (presumably a debugger) that the exec has completed.  */
208     __msg_sig_post (_hurd_msgport, SIGTRAP, TRAP_TRACE, __mach_task_self ());
209 }
210 
211 #include <shlib-compat.h>
212 versioned_symbol (libc, _hurd_new_proc_init, _hurd_proc_init, GLIBC_2_1);
213 
214 /* Called when we get a message telling us to change our proc server port.  */
215 
216 error_t
_hurd_setproc(process_t procserver)217 _hurd_setproc (process_t procserver)
218 {
219   error_t err;
220   mach_port_t oldmsg;
221 
222   /* Give the proc server our message port.  */
223   if (err = __proc_setmsgport (procserver, _hurd_msgport, &oldmsg))
224     return err;
225   if (oldmsg != MACH_PORT_NULL)
226     /* Deallocate the old msg port we replaced.  */
227     __mach_port_deallocate (__mach_task_self (), oldmsg);
228 
229   /* Tell the proc server where our args and environment are.  */
230   if (err = __proc_set_arg_locations (procserver,
231 				      _hide_arguments ? 0
232 				      : (vm_address_t) __libc_argv,
233 				      _hide_environment ? 0
234 				      : (vm_address_t) __environ))
235     return err;
236 
237   /* Those calls worked, so the port looks good.  */
238   _hurd_port_set (&_hurd_ports[INIT_PORT_PROC], procserver);
239 
240   {
241     pid_t oldpgrp = _hurd_pgrp;
242 
243     /* Call these functions again so they can fetch the
244        new information from the new proc server.  */
245     RUN_RELHOOK (_hurd_proc_subinit, ());
246 
247     if (_hurd_pgrp != oldpgrp)
248       {
249 	/* Run things that want notification of a pgrp change.  */
250 	DECLARE_HOOK (_hurd_pgrp_changed_hook, (pid_t));
251 	RUN_HOOK (_hurd_pgrp_changed_hook, (_hurd_pgrp));
252       }
253   }
254 
255   return 0;
256 }
257