1 /* Copyright (C) 1991, 92, 93, 94, 95, 96, 97 Free Software Foundation, Inc.
2 This file is part of the GNU C Library.
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.
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.
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 not,
16 write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
17 Boston, MA 02111-1307, USA. */
22 #include <hurd/signal.h>
23 #include <cthreads.h> /* For `struct mutex'. */
25 #include "hurdfault.h"
26 #include "hurdmalloc.h" /* XXX */
28 const char *_hurdsig_getenv (const char *);
30 struct mutex _hurd_siglock
;
33 /* Port that receives signals and other miscellaneous messages. */
34 mach_port_t _hurd_msgport
;
36 /* Thread listening on it. */
37 thread_t _hurd_msgport_thread
;
39 /* Thread which receives task-global signals. */
40 thread_t _hurd_sigthread
;
42 /* These are set up by _hurdsig_init. */
43 unsigned long int __hurd_sigthread_stack_base
;
44 unsigned long int __hurd_sigthread_stack_end
;
45 unsigned long int *__hurd_sigthread_variables
;
47 /* Linked-list of per-thread signal state. */
48 struct hurd_sigstate
*_hurd_sigstates
;
50 /* Timeout for RPC's after interrupt_operation. */
51 mach_msg_timeout_t _hurd_interrupted_rpc_timeout
= 3000;
54 default_sigaction (struct sigaction actions
[NSIG
])
58 __sigemptyset (&actions
[0].sa_mask
);
59 actions
[0].sa_flags
= SA_RESTART
;
60 actions
[0].sa_handler
= SIG_DFL
;
62 for (signo
= 1; signo
< NSIG
; ++signo
)
63 actions
[signo
] = actions
[0];
66 struct hurd_sigstate
*
67 _hurd_thread_sigstate (thread_t thread
)
69 struct hurd_sigstate
*ss
;
70 __mutex_lock (&_hurd_siglock
);
71 for (ss
= _hurd_sigstates
; ss
!= NULL
; ss
= ss
->next
)
72 if (ss
->thread
== thread
)
76 ss
= malloc (sizeof (*ss
));
78 __libc_fatal ("hurd: Can't allocate thread sigstate\n");
80 __spin_lock_init (&ss
->lock
);
82 /* Initialize default state. */
83 __sigemptyset (&ss
->blocked
);
84 __sigemptyset (&ss
->pending
);
85 memset (&ss
->sigaltstack
, 0, sizeof (ss
->sigaltstack
));
86 ss
->preemptors
= NULL
;
88 ss
->intr_port
= MACH_PORT_NULL
;
91 /* Initialize the sigaction vector from the default signal receiving
92 thread's state, and its from the system defaults. */
93 if (thread
== _hurd_sigthread
)
94 default_sigaction (ss
->actions
);
97 struct hurd_sigstate
*s
;
98 for (s
= _hurd_sigstates
; s
!= NULL
; s
= s
->next
)
99 if (s
->thread
== _hurd_sigthread
)
103 __spin_lock (&s
->lock
);
104 memcpy (ss
->actions
, s
->actions
, sizeof (s
->actions
));
105 __spin_unlock (&s
->lock
);
108 default_sigaction (ss
->actions
);
111 ss
->next
= _hurd_sigstates
;
112 _hurd_sigstates
= ss
;
114 __mutex_unlock (&_hurd_siglock
);
118 /* Signal delivery itself is on this page. */
121 #include <hurd/crash.h>
122 #include <hurd/paths.h>
125 #include <sys/wait.h>
126 #include "thread_state.h"
127 #include <hurd/msg_server.h>
128 #include <hurd/msg_reply.h> /* For __msg_sig_post_reply. */
129 #include <hurd/interrupt.h>
133 int _hurd_core_limit
; /* XXX */
135 /* Call the crash dump server to mummify us before we die.
136 Returns nonzero if a core file was written. */
138 write_corefile (int signo
, const struct hurd_signal_detail
*detail
)
141 mach_port_t coreserver
;
142 file_t file
, coredir
;
146 When we have a protocol to make the server return an error
147 for RLIMIT_FSIZE, then tell the corefile fs server the RLIMIT_CORE
148 value in place of the RLIMIT_FSIZE value. */
150 /* First get a port to the core dumping server. */
151 coreserver
= MACH_PORT_NULL
;
152 name
= _hurdsig_getenv ("CRASHSERVER");
154 coreserver
= __file_name_lookup (name
, 0, 0);
155 if (coreserver
== MACH_PORT_NULL
)
156 coreserver
= __file_name_lookup (_SERVERS_CRASH
, 0, 0);
157 if (coreserver
== MACH_PORT_NULL
)
160 /* Get a port to the directory where the new core file will reside. */
161 file
= MACH_PORT_NULL
;
162 name
= _hurdsig_getenv ("COREFILE");
165 coredir
= __file_name_split (name
, (char **) &name
);
166 if (coredir
!= MACH_PORT_NULL
)
167 /* Create the new file, but don't link it into the directory yet. */
168 __dir_mkfile (coredir
, O_WRONLY
|O_CREAT
,
169 0600 & ~_hurd_umask
, /* XXX ? */
172 /* Call the core dumping server to write the core file. */
173 err
= __crash_dump_task (coreserver
,
176 signo
, detail
->code
, detail
->error
,
177 detail
->exc
, detail
->exc_code
, detail
->exc_subcode
,
178 _hurd_ports
[INIT_PORT_CTTYID
].port
,
179 MACH_MSG_TYPE_COPY_SEND
);
180 __mach_port_deallocate (__mach_task_self (), coreserver
);
182 if (! err
&& file
!= MACH_PORT_NULL
)
183 /* The core dump into FILE succeeded, so now link it into the
185 err
= __dir_link (file
, coredir
, name
, 1);
186 __mach_port_deallocate (__mach_task_self (), file
);
187 __mach_port_deallocate (__mach_task_self (), coredir
);
188 return !err
&& file
!= MACH_PORT_NULL
;
192 /* The lowest-numbered thread state flavor value is 1,
193 so we use bit 0 in machine_thread_all_state.set to
194 record whether we have done thread_abort. */
195 #define THREAD_ABORTED 1
197 /* SS->thread is suspended. Abort the thread and get its basic state. */
199 abort_thread (struct hurd_sigstate
*ss
, struct machine_thread_all_state
*state
,
200 void (*reply
) (void))
202 if (!(state
->set
& THREAD_ABORTED
))
204 error_t err
= __thread_abort (ss
->thread
);
206 /* Clear all thread state flavor set bits, because thread_abort may
207 have changed the state. */
208 state
->set
= THREAD_ABORTED
;
214 machine_get_basic_state (ss
->thread
, state
);
217 /* Find the location of the MiG reply port cell in use by the thread whose
218 state is described by THREAD_STATE. If SIGTHREAD is nonzero, make sure
219 that this location can be set without faulting, or else return NULL. */
222 interrupted_reply_port_location (struct machine_thread_all_state
*thread_state
,
225 mach_port_t
*portloc
= (mach_port_t
*) __hurd_threadvar_location_from_sp
226 (_HURD_THREADVAR_MIG_REPLY
, (void *) thread_state
->basic
.SP
);
228 if (sigthread
&& _hurdsig_catch_memory_fault (portloc
))
229 /* Faulted trying to read the stack. */
232 /* Fault now if this pointer is bogus. */
233 *(volatile mach_port_t
*) portloc
= *portloc
;
236 _hurdsig_end_catch_fault ();
241 #include <hurd/sigpreempt.h>
242 #include "intr-msg.h"
244 /* Timeout on interrupt_operation calls. */
245 mach_msg_timeout_t _hurdsig_interrupt_timeout
= 1000;
247 /* SS->thread is suspended.
249 Abort any interruptible RPC operation the thread is doing.
251 This uses only the constant member SS->thread and the unlocked, atomically
252 set member SS->intr_port, so no locking is needed.
254 If successfully sent an interrupt_operation and therefore the thread should
255 wait for its pending RPC to return (possibly EINTR) before taking the
256 incoming signal, returns the reply port to be received on. Otherwise
257 returns MACH_PORT_NULL.
259 SIGNO is used to find the applicable SA_RESTART bit. If SIGNO is zero,
260 the RPC fails with EINTR instead of restarting (thread_cancel).
262 *STATE_CHANGE is set nonzero if STATE->basic was modified and should
263 be applied back to the thread if it might ever run again, else zero. */
266 _hurdsig_abort_rpcs (struct hurd_sigstate
*ss
, int signo
, int sigthread
,
267 struct machine_thread_all_state
*state
, int *state_change
,
268 void (*reply
) (void))
270 extern const void _hurd_intr_rpc_msg_in_trap
;
271 mach_port_t rcv_port
= MACH_PORT_NULL
;
272 mach_port_t intr_port
;
276 intr_port
= ss
->intr_port
;
277 if (intr_port
== MACH_PORT_NULL
)
278 /* No interruption needs done. */
279 return MACH_PORT_NULL
;
281 /* Abort the thread's kernel context, so any pending message send or
282 receive completes immediately or aborts. */
283 abort_thread (ss
, state
, reply
);
285 if (state
->basic
.PC
< (natural_t
) &_hurd_intr_rpc_msg_in_trap
)
287 /* The thread is about to do the RPC, but hasn't yet entered
288 mach_msg. Mutate the thread's state so it knows not to try
290 INTR_MSG_BACK_OUT (&state
->basic
);
291 MACHINE_THREAD_STATE_SET_PC (&state
->basic
,
292 &_hurd_intr_rpc_msg_in_trap
);
293 state
->basic
.SYSRETURN
= MACH_SEND_INTERRUPTED
;
296 else if (state
->basic
.PC
== (natural_t
) &_hurd_intr_rpc_msg_in_trap
&&
297 /* The thread was blocked in the system call. After thread_abort,
298 the return value register indicates what state the RPC was in
300 state
->basic
.SYSRETURN
== MACH_RCV_INTERRUPTED
)
302 /* The RPC request message was sent and the thread was waiting for
303 the reply message; now the message receive has been aborted, so
304 the mach_msg call will return MACH_RCV_INTERRUPTED. We must tell
305 the server to interrupt the pending operation. The thread must
306 wait for the reply message before running the signal handler (to
307 guarantee that the operation has finished being interrupted), so
308 our nonzero return tells the trampoline code to finish the message
309 receive operation before running the handler. */
311 mach_port_t
*reply
= interrupted_reply_port_location (state
,
313 error_t err
= __interrupt_operation (intr_port
, _hurdsig_interrupt_timeout
);
319 /* The interrupt didn't work.
320 Destroy the receive right the thread is blocked on. */
321 __mach_port_destroy (__mach_task_self (), *reply
);
322 *reply
= MACH_PORT_NULL
;
325 /* The system call return value register now contains
326 MACH_RCV_INTERRUPTED; when mach_msg resumes, it will retry the
327 call. Since we have just destroyed the receive right, the
328 retry will fail with MACH_RCV_INVALID_NAME. Instead, just
329 change the return value here to EINTR so mach_msg will not
330 retry and the EINTR error code will propagate up. */
331 state
->basic
.SYSRETURN
= EINTR
;
337 /* All threads whose RPCs were interrupted by the interrupt_operation
338 call above will retry their RPCs unless we clear SS->intr_port.
339 So we clear it for the thread taking a signal when SA_RESTART is
340 clear, so that its call returns EINTR. */
341 if (! signo
|| !(ss
->actions
[signo
].sa_flags
& SA_RESTART
))
342 ss
->intr_port
= MACH_PORT_NULL
;
349 /* Abort the RPCs being run by all threads but this one;
350 all other threads should be suspended. If LIVE is nonzero, those
351 threads may run again, so they should be adjusted as necessary to be
352 happy when resumed. STATE is clobbered as a scratch area; its initial
353 contents are ignored, and its contents on return are not useful. */
356 abort_all_rpcs (int signo
, struct machine_thread_all_state
*state
, int live
)
358 /* We can just loop over the sigstates. Any thread doing something
359 interruptible must have one. We needn't bother locking because all
360 other threads are stopped. */
362 struct hurd_sigstate
*ss
;
364 mach_port_t
*reply_ports
;
366 /* First loop over the sigstates to count them.
367 We need to know how big a vector we will need for REPLY_PORTS. */
369 for (ss
= _hurd_sigstates
; ss
!= NULL
; ss
= ss
->next
)
372 reply_ports
= alloca (nthreads
* sizeof *reply_ports
);
375 for (ss
= _hurd_sigstates
; ss
!= NULL
; ss
= ss
->next
, ++nthreads
)
376 if (ss
->thread
== _hurd_msgport_thread
)
377 reply_ports
[nthreads
] = MACH_PORT_NULL
;
381 state
->set
= 0; /* Reset scratch area. */
383 /* Abort any operation in progress with interrupt_operation.
384 Record the reply port the thread is waiting on.
385 We will wait for all the replies below. */
386 reply_ports
[nthreads
] = _hurdsig_abort_rpcs (ss
, signo
, 1,
387 state
, &state_changed
,
391 if (reply_ports
[nthreads
] != MACH_PORT_NULL
)
393 /* We will wait for the reply to this RPC below, so the
394 thread must issue a new RPC rather than waiting for the
395 reply to the one it sent. */
396 state
->basic
.SYSRETURN
= EINTR
;
400 /* Aborting the RPC needed to change this thread's state,
401 and it might ever run again. So write back its state. */
402 __thread_set_state (ss
->thread
, MACHINE_THREAD_STATE_FLAVOR
,
403 (natural_t
*) &state
->basic
,
404 MACHINE_THREAD_STATE_COUNT
);
408 /* Wait for replies from all the successfully interrupted RPCs. */
409 while (nthreads
-- > 0)
410 if (reply_ports
[nthreads
] != MACH_PORT_NULL
)
413 mach_msg_header_t head
;
414 err
= __mach_msg (&head
, MACH_RCV_MSG
|MACH_RCV_TIMEOUT
, 0, sizeof head
,
415 reply_ports
[nthreads
],
416 _hurd_interrupted_rpc_timeout
, MACH_PORT_NULL
);
419 case MACH_RCV_TIMED_OUT
:
420 case MACH_RCV_TOO_LARGE
:
429 struct hurd_signal_preemptor
*_hurdsig_preemptors
= 0;
430 sigset_t _hurdsig_preempted_set
;
432 /* XXX temporary to deal with spelling fix */
433 weak_alias (_hurdsig_preemptors
, _hurdsig_preempters
)
435 /* Mask of stop signals. */
436 #define STOPSIGS (sigmask (SIGTTIN) | sigmask (SIGTTOU) | \
437 sigmask (SIGSTOP) | sigmask (SIGTSTP))
439 /* Deliver a signal. SS is not locked. */
441 _hurd_internal_post_signal (struct hurd_sigstate
*ss
,
442 int signo
, struct hurd_signal_detail
*detail
,
443 mach_port_t reply_port
,
444 mach_msg_type_name_t reply_port_type
,
448 struct machine_thread_all_state thread_state
;
449 enum { stop
, ignore
, core
, term
, handle
} act
;
450 struct hurd_signal_preemptor
*pe
;
451 sighandler_t handler
;
455 /* Reply to this sig_post message. */
456 __typeof (__msg_sig_post_reply
) *reply_rpc
457 = (untraced
? __msg_sig_post_untraced_reply
: __msg_sig_post_reply
);
461 if (reply_port
== MACH_PORT_NULL
)
463 err
= (*reply_rpc
) (reply_port
, reply_port_type
, 0);
464 reply_port
= MACH_PORT_NULL
;
465 if (err
!= MACH_SEND_INVALID_DEST
) /* Ignore dead reply port. */
469 /* Mark the signal as pending. */
470 void mark_pending (void)
472 __sigaddset (&ss
->pending
, signo
);
473 /* Save the details to be given to the handler when SIGNO is
475 ss
->pending_data
[signo
] = *detail
;
478 /* Suspend the process with SIGNO. */
481 /* Stop all other threads and mark ourselves stopped. */
484 /* Hold the siglock while stopping other threads to be
485 sure it is not held by another thread afterwards. */
486 __mutex_lock (&_hurd_siglock
);
487 __proc_dostop (port
, _hurd_msgport_thread
);
488 __mutex_unlock (&_hurd_siglock
);
489 abort_all_rpcs (signo
, &thread_state
, 1);
491 __proc_mark_stop (port
, signo
, detail
->code
);
495 /* Resume the process after a suspension. */
498 /* Resume the process from being stopped. */
500 mach_msg_type_number_t nthreads
, i
;
506 /* Tell the proc server we are continuing. */
507 __USEPORT (PROC
, __proc_mark_cont (port
));
508 /* Fetch ports to all our threads and resume them. */
509 err
= __task_threads (__mach_task_self (), &threads
, &nthreads
);
511 for (i
= 0; i
< nthreads
; ++i
)
513 if (threads
[i
] != _hurd_msgport_thread
&&
514 (act
!= handle
|| threads
[i
] != ss
->thread
))
516 err
= __thread_resume (threads
[i
]);
519 err
= __mach_port_deallocate (__mach_task_self (),
523 __vm_deallocate (__mach_task_self (),
524 (vm_address_t
) threads
,
525 nthreads
* sizeof *threads
);
528 /* The thread that will run the handler is already suspended. */
535 /* This is PTRACE_CONTINUE. */
538 /* This call is just to check for pending signals. */
539 __spin_lock (&ss
->lock
);
540 goto check_pending_signals
;
545 thread_state
.set
= 0; /* We know nothing. */
547 __spin_lock (&ss
->lock
);
549 /* Check for a preempted signal. Preempted signals can arrive during
550 critical sections. */
553 for (pe
= ss
->preemptors
; pe
&& handler
== SIG_ERR
; pe
= pe
->next
)
554 if (HURD_PREEMPT_SIGNAL_P (pe
, signo
, detail
->code
))
555 handler
= (*pe
->preemptor
) (pe
, ss
, &signo
, detail
);
557 if (handler
== SIG_ERR
&& (__sigmask (signo
) & _hurdsig_preempted_set
))
559 __mutex_lock (&_hurd_siglock
);
560 for (pe
= _hurdsig_preemptors
; pe
&& handler
== SIG_ERR
; pe
= pe
->next
)
561 if (HURD_PREEMPT_SIGNAL_P (pe
, signo
, detail
->code
))
562 handler
= (*pe
->preemptor
) (pe
, ss
, &signo
, detail
);
563 __mutex_unlock (&_hurd_siglock
);
568 if (handler
== SIG_IGN
)
569 /* Ignore the signal altogether. */
571 if (handler
!= SIG_ERR
)
572 /* Run the preemption-provided handler. */
576 /* No preemption. Do normal handling. */
578 if (!untraced
&& __sigismember (&_hurdsig_traced
, signo
))
580 /* We are being traced. Stop to tell the debugger of the signal. */
582 /* Already stopped. Mark the signal as pending;
583 when resumed, we will notice it and stop again. */
587 __spin_unlock (&ss
->lock
);
592 handler
= ss
->actions
[signo
].sa_handler
;
594 if (handler
== SIG_DFL
)
595 /* Figure out the default action for this signal. */
599 /* A sig_post msg with SIGNO==0 is sent to
600 tell us to check for pending signals. */
632 if (_hurd_pgrp
== _hurd_pid
)
634 /* We are the process group leader. Since there is no
635 user-specified handler for SIGINFO, we use a default one
636 which prints something interesting. We use the normal
637 handler mechanism instead of just doing it here to avoid
638 the signal thread faulting or blocking in this
639 potentially hairy operation. */
641 handler
= _hurd_siginfo_handler
;
651 else if (handler
== SIG_IGN
)
656 if (__sigmask (signo
) & STOPSIGS
)
657 /* Stop signals clear a pending SIGCONT even if they
658 are handled or ignored (but not if preempted). */
659 ss
->pending
&= ~sigmask (SIGCONT
);
662 if (signo
== SIGCONT
)
663 /* Even if handled or ignored (but not preempted), SIGCONT clears
664 stop signals and resumes the process. */
665 ss
->pending
&= ~STOPSIGS
;
667 if (_hurd_stopped
&& act
!= stop
&& (untraced
|| signo
== SIGCONT
))
672 if (_hurd_orphaned
&& act
== stop
&&
673 (__sigmask (signo
) & (__sigmask (SIGTTIN
) | __sigmask (SIGTTOU
) |
674 __sigmask (SIGTSTP
))))
676 /* If we would ordinarily stop for a job control signal, but we are
677 orphaned so noone would ever notice and continue us again, we just
678 quietly die, alone and in the dark. */
679 detail
->code
= signo
;
684 /* Handle receipt of a blocked signal, or any signal while stopped. */
685 if (act
!= ignore
&& /* Signals ignored now are forgotten now. */
686 __sigismember (&ss
->blocked
, signo
) ||
687 (signo
!= SIGKILL
&& _hurd_stopped
))
693 /* Perform the chosen action for the signal. */
699 /* We are already stopped, but receiving an untraced stop
700 signal. Instead of resuming and suspending again, just
701 notify the proc server of the new stop signal. */
702 error_t err
= __USEPORT (PROC
, __proc_mark_stop
703 (port
, signo
, detail
->code
));
707 /* Suspend the process. */
712 /* Nobody cares about this signal. If there was a call to resume
713 above in SIGCONT processing and we've left a thread suspended,
714 now's the time to set it going. */
717 err
= __thread_resume (ss
->thread
);
724 /* We got a fault setting up the stack frame for the handler.
725 Nothing to do but die; BSD gets SIGILL in this case. */
726 detail
->code
= signo
; /* XXX ? */
731 case term
: /* Time to die. */
732 case core
: /* And leave a rotting corpse. */
733 /* Have the proc server stop all other threads in our task. */
734 err
= __USEPORT (PROC
, __proc_dostop (port
, _hurd_msgport_thread
));
736 /* No more user instructions will be executed.
737 The signal can now be considered delivered. */
739 /* Abort all server operations now in progress. */
740 abort_all_rpcs (signo
, &thread_state
, 0);
743 int status
= W_EXITCODE (0, signo
);
744 /* Do a core dump if desired. Only set the wait status bit saying we
745 in fact dumped core if the operation was actually successful. */
746 if (act
== core
&& write_corefile (signo
, detail
))
748 /* Tell proc how we died and then stick the saber in the gut. */
754 /* Call a handler for this signal. */
756 struct sigcontext
*scp
, ocontext
;
757 int wait_for_reply
, state_changed
;
759 /* Stop the thread and abort its pending RPC operations. */
762 err
= __thread_suspend (ss
->thread
);
766 /* Abort the thread's kernel context, so any pending message send
767 or receive completes immediately or aborts. If an interruptible
768 RPC is in progress, abort_rpcs will do this. But we must always
769 do it before fetching the thread's state, because
770 thread_get_state is never kosher before thread_abort. */
771 abort_thread (ss
, &thread_state
, NULL
);
775 /* We have a previous sigcontext that sigreturn was about
776 to restore when another signal arrived. */
780 if (_hurdsig_catch_memory_fault (ss
->context
))
782 /* We faulted reading the thread's stack. Forget that
783 context and pretend it wasn't there. It almost
784 certainly crash if this handler returns, but that's it's
790 /* Copy the context from the thread's stack before
791 we start diddling the stack to set up the handler. */
792 ocontext
= *ss
->context
;
793 ss
->context
= &ocontext
;
795 _hurdsig_end_catch_fault ();
797 if (! machine_get_basic_state (ss
->thread
, &thread_state
))
799 loc
= interrupted_reply_port_location (&thread_state
, 1);
800 if (loc
&& *loc
!= MACH_PORT_NULL
)
801 /* This is the reply port for the context which called
802 sigreturn. Since we are abandoning that context entirely
803 and restoring SS->context instead, destroy this port. */
804 __mach_port_destroy (__mach_task_self (), *loc
);
806 /* The thread was in sigreturn, not in any interruptible RPC. */
809 assert (! __spin_lock_locked (&ss
->critical_section_lock
));
813 int crit
= __spin_lock_locked (&ss
->critical_section_lock
);
816 = (_hurdsig_abort_rpcs (ss
,
817 /* In a critical section, any RPC
818 should be cancelled instead of
819 restarted, regardless of
820 SA_RESTART, so the the entire
821 "atomic" operation can be aborted
824 &thread_state
, &state_changed
,
830 /* The thread is in a critical section. Mark the signal as
831 pending. When it finishes the critical section, it will
832 check for pending signals. */
835 /* Some cases of interrupting an RPC must change the
836 thread state to back out the call. Normally this
837 change is rolled into the warping to the handler and
838 sigreturn, but we are not running the handler now
839 because the thread is in a critical section. Instead,
840 mutate the thread right away for the RPC interruption
841 and resume it; the RPC will return early so the
842 critical section can end soon. */
843 __thread_set_state (ss
->thread
, MACHINE_THREAD_STATE_FLAVOR
,
844 (natural_t
*) &thread_state
.basic
,
845 MACHINE_THREAD_STATE_COUNT
);
847 ss
->intr_port
= MACH_PORT_NULL
;
848 __thread_resume (ss
->thread
);
853 /* Call the machine-dependent function to set the thread up
854 to run the signal handler, and preserve its old context. */
855 scp
= _hurd_setup_sighandler (ss
, handler
, signo
, detail
,
856 wait_for_reply
, &thread_state
);
860 /* Set the machine-independent parts of the signal context. */
863 /* Fetch the thread variable for the MiG reply port,
864 and set it to MACH_PORT_NULL. */
865 mach_port_t
*loc
= interrupted_reply_port_location (&thread_state
,
869 scp
->sc_reply_port
= *loc
;
870 *loc
= MACH_PORT_NULL
;
873 scp
->sc_reply_port
= MACH_PORT_NULL
;
875 /* Save the intr_port in use by the interrupted code,
876 and clear the cell before running the trampoline. */
877 scp
->sc_intr_port
= ss
->intr_port
;
878 ss
->intr_port
= MACH_PORT_NULL
;
882 /* After the handler runs we will restore to the state in
883 SS->context, not the state of the thread now. So restore
884 that context's reply port and intr port. */
886 scp
->sc_reply_port
= ss
->context
->sc_reply_port
;
887 scp
->sc_intr_port
= ss
->context
->sc_intr_port
;
893 /* Backdoor extra argument to signal handler. */
894 scp
->sc_error
= detail
->error
;
896 /* Block SIGNO and requested signals while running the handler. */
897 scp
->sc_mask
= ss
->blocked
;
898 ss
->blocked
|= __sigmask (signo
) | ss
->actions
[signo
].sa_mask
;
900 /* Start the thread running the handler (or possibly waiting for an
901 RPC reply before running the handler). */
902 err
= __thread_set_state (ss
->thread
, MACHINE_THREAD_STATE_FLAVOR
,
903 (natural_t
*) &thread_state
.basic
,
904 MACHINE_THREAD_STATE_COUNT
);
906 err
= __thread_resume (ss
->thread
);
908 thread_state
.set
= 0; /* Everything we know is now wrong. */
913 /* The signal has either been ignored or is now being handled. We can
914 consider it delivered and reply to the killer. */
917 /* We get here unless the signal was fatal. We still hold SS->lock.
918 Check for pending signals, and loop to post them. */
920 /* Return nonzero if SS has any signals pending we should worry about.
921 We don't worry about any pending signals if we are stopped, nor if
922 SS is in a critical section. We are guaranteed to get a sig_post
923 message before any of them become deliverable: either the SIGCONT
924 signal, or a sig_post with SIGNO==0 as an explicit poll when the
925 thread finishes its critical section. */
926 inline int signals_pending (void)
928 if (_hurd_stopped
|| __spin_lock_locked (&ss
->critical_section_lock
))
930 return pending
= ss
->pending
& ~ss
->blocked
;
933 check_pending_signals
:
936 if (signals_pending ())
938 for (signo
= 1; signo
< NSIG
; ++signo
)
939 if (__sigismember (&pending
, signo
))
942 __sigdelset (&ss
->pending
, signo
);
943 *detail
= ss
->pending_data
[signo
];
944 __spin_unlock (&ss
->lock
);
949 /* No pending signals left undelivered for this thread.
950 If we were sent signal 0, we need to check for pending
951 signals for all threads. */
954 __spin_unlock (&ss
->lock
);
955 __mutex_lock (&_hurd_siglock
);
956 for (ss
= _hurd_sigstates
; ss
!= NULL
; ss
= ss
->next
)
958 __spin_lock (&ss
->lock
);
959 for (signo
= 1; signo
< NSIG
; ++signo
)
960 if (__sigismember (&ss
->pending
, signo
)
961 && (!__sigismember (&ss
->blocked
, signo
)
962 /* We "deliver" immediately pending blocked signals whose
963 action might be to ignore, so that if ignored they are
964 dropped right away. */
965 || ss
->actions
[signo
].sa_handler
== SIG_IGN
966 || ss
->actions
[signo
].sa_handler
== SIG_DFL
))
968 mutex_unlock (&_hurd_siglock
);
969 goto deliver_pending
;
971 __spin_unlock (&ss
->lock
);
973 __mutex_unlock (&_hurd_siglock
);
977 /* No more signals pending; SS->lock is still locked.
978 Wake up any sigsuspend call that is blocking SS->thread. */
979 if (ss
->suspended
!= MACH_PORT_NULL
)
981 /* There is a sigsuspend waiting. Tell it to wake up. */
983 mach_msg_header_t msg
;
984 err
= __mach_port_insert_right (__mach_task_self (),
985 ss
->suspended
, ss
->suspended
,
986 MACH_MSG_TYPE_MAKE_SEND
);
988 msg
.msgh_bits
= MACH_MSGH_BITS (MACH_MSG_TYPE_MOVE_SEND
, 0);
989 msg
.msgh_remote_port
= ss
->suspended
;
990 msg
.msgh_local_port
= MACH_PORT_NULL
;
991 /* These values do not matter. */
992 msg
.msgh_id
= 8675309; /* Jenny, Jenny. */
993 msg
.msgh_seqno
= 17; /* Random. */
994 ss
->suspended
= MACH_PORT_NULL
;
995 err
= __mach_msg (&msg
, MACH_SEND_MSG
, sizeof msg
, 0,
996 MACH_PORT_NULL
, MACH_MSG_TIMEOUT_NONE
,
1000 __spin_unlock (&ss
->lock
);
1004 /* All pending signals delivered to all threads.
1005 Now we can send the reply message even for signal 0. */
1009 /* Decide whether REFPORT enables the sender to send us a SIGNO signal.
1010 Returns zero if so, otherwise the error code to return to the sender. */
1013 signal_allowed (int signo
, mach_port_t refport
)
1015 if (signo
< 0 || signo
>= NSIG
)
1018 if (refport
== __mach_task_self ())
1019 /* Can send any signal. */
1022 /* Avoid needing to check for this below. */
1023 if (refport
== MACH_PORT_NULL
)
1036 /* Job control signals can be sent by the controlling terminal. */
1037 if (__USEPORT (CTTYID
, port
== refport
))
1043 /* A continue signal can be sent by anyone in the session. */
1044 mach_port_t sessport
;
1045 if (! __USEPORT (PROC
, __proc_getsidport (port
, &sessport
)))
1047 __mach_port_deallocate (__mach_task_self (), sessport
);
1048 if (refport
== sessport
)
1057 /* Any io object a file descriptor refers to might send us
1058 one of these signals using its async ID port for REFPORT.
1060 This is pretty wide open; it is not unlikely that some random
1061 process can at least open for reading something we have open,
1062 get its async ID port, and send us a spurious SIGIO or SIGURG
1063 signal. But BSD is actually wider open than that!--you can set
1064 the owner of an io object to any process or process group
1065 whatsoever and send them gratuitous signals.
1067 Someday we could implement some reasonable scheme for
1068 authorizing SIGIO and SIGURG signals properly. */
1071 int lucky
= 0; /* True if we find a match for REFPORT. */
1072 __mutex_lock (&_hurd_dtable_lock
);
1073 for (d
= 0; !lucky
&& (unsigned) d
< (unsigned) _hurd_dtablesize
; ++d
)
1075 struct hurd_userlink ulink
;
1077 mach_port_t asyncid
;
1078 if (_hurd_dtable
[d
] == NULL
)
1080 port
= _hurd_port_get (&_hurd_dtable
[d
]->port
, &ulink
);
1081 if (! __io_get_icky_async_id (port
, &asyncid
))
1083 if (refport
== asyncid
)
1084 /* Break out of the loop on the next iteration. */
1086 __mach_port_deallocate (__mach_task_self (), asyncid
);
1088 _hurd_port_free (&_hurd_dtable
[d
]->port
, &ulink
, port
);
1090 /* If we found a lucky winner, we've set D to -1 in the loop. */
1096 /* If this signal is legit, we have done `goto win' by now.
1097 When we return the error, mig deallocates REFPORT. */
1101 /* Deallocate the REFPORT send right; we are done with it. */
1102 __mach_port_deallocate (__mach_task_self (), refport
);
1107 /* Implement the sig_post RPC from <hurd/msg.defs>;
1108 sent when someone wants us to get a signal. */
1110 _S_msg_sig_post (mach_port_t me
,
1111 mach_port_t reply_port
, mach_msg_type_name_t reply_port_type
,
1112 int signo
, natural_t sigcode
,
1113 mach_port_t refport
)
1116 struct hurd_signal_detail d
;
1118 if (err
= signal_allowed (signo
, refport
))
1124 /* Post the signal to the designated signal-receiving thread. This will
1125 reply when the signal can be considered delivered. */
1126 _hurd_internal_post_signal (_hurd_thread_sigstate (_hurd_sigthread
),
1127 signo
, &d
, reply_port
, reply_port_type
,
1128 0); /* Stop if traced. */
1130 return MIG_NO_REPLY
; /* Already replied. */
1133 /* Implement the sig_post_untraced RPC from <hurd/msg.defs>;
1134 sent when the debugger wants us to really get a signal
1135 even if we are traced. */
1137 _S_msg_sig_post_untraced (mach_port_t me
,
1138 mach_port_t reply_port
,
1139 mach_msg_type_name_t reply_port_type
,
1140 int signo
, natural_t sigcode
,
1141 mach_port_t refport
)
1144 struct hurd_signal_detail d
;
1146 if (err
= signal_allowed (signo
, refport
))
1152 /* Post the signal to the designated signal-receiving thread. This will
1153 reply when the signal can be considered delivered. */
1154 _hurd_internal_post_signal (_hurd_thread_sigstate (_hurd_sigthread
),
1155 signo
, &d
, reply_port
, reply_port_type
,
1156 1); /* Untraced flag. */
1158 return MIG_NO_REPLY
; /* Already replied. */
1161 extern void __mig_init (void *);
1163 #include <mach/task_special_ports.h>
1165 /* Initialize the message port and _hurd_sigthread and start the signal
1169 _hurdsig_init (void)
1172 vm_size_t stacksize
;
1174 __mutex_init (&_hurd_siglock
);
1176 err
= __mach_port_allocate (__mach_task_self (),
1177 MACH_PORT_RIGHT_RECEIVE
,
1179 assert_perror (err
);
1181 /* Make a send right to the signal port. */
1182 err
= __mach_port_insert_right (__mach_task_self (),
1185 MACH_MSG_TYPE_MAKE_SEND
);
1186 assert_perror (err
);
1188 /* Set the default thread to receive task-global signals
1189 to this one, the main (first) user thread. */
1190 _hurd_sigthread
= __mach_thread_self ();
1192 /* Start the signal thread listening on the message port. */
1194 err
= __thread_create (__mach_task_self (), &_hurd_msgport_thread
);
1195 assert_perror (err
);
1197 stacksize
= __vm_page_size
* 4; /* Small stack for signal thread. */
1198 err
= __mach_setup_thread (__mach_task_self (), _hurd_msgport_thread
,
1199 _hurd_msgport_receive
,
1200 (vm_address_t
*) &__hurd_sigthread_stack_base
,
1202 assert_perror (err
);
1204 __hurd_sigthread_stack_end
= __hurd_sigthread_stack_base
+ stacksize
;
1205 __hurd_sigthread_variables
=
1206 malloc (__hurd_threadvar_max
* sizeof (unsigned long int));
1207 if (__hurd_sigthread_variables
== NULL
)
1208 __libc_fatal ("hurd: Can't allocate thread variables for signal thread\n");
1210 /* Reinitialize the MiG support routines so they will use a per-thread
1211 variable for the cached reply port. */
1212 __mig_init ((void *) __hurd_sigthread_stack_base
);
1214 err
= __thread_resume (_hurd_msgport_thread
);
1215 assert_perror (err
);
1217 /* Receive exceptions on the signal port. */
1218 __task_set_special_port (__mach_task_self (),
1219 TASK_EXCEPTION_PORT
, _hurd_msgport
);
1222 /* Reauthenticate with the proc server. */
1225 reauth_proc (mach_port_t
new)
1227 mach_port_t ref
, ignore
;
1229 ref
= __mach_reply_port ();
1230 if (! HURD_PORT_USE (&_hurd_ports
[INIT_PORT_PROC
],
1231 __proc_reauthenticate (port
, ref
,
1232 MACH_MSG_TYPE_MAKE_SEND
) ||
1233 __auth_user_authenticate (new, ref
,
1234 MACH_MSG_TYPE_MAKE_SEND
,
1236 && ignore
!= MACH_PORT_NULL
)
1237 __mach_port_deallocate (__mach_task_self (), ignore
);
1238 __mach_port_destroy (__mach_task_self (), ref
);
1240 (void) &reauth_proc
; /* Silence compiler warning. */
1242 text_set_element (_hurd_reauth_hook
, reauth_proc
);
1244 /* Like `getenv', but safe for the signal thread to run.
1245 If the environment is trashed, this will just return NULL. */
1248 _hurdsig_getenv (const char *variable
)
1250 if (_hurdsig_catch_memory_fault (__environ
))
1251 /* We bombed in getenv. */
1255 const size_t len
= strlen (variable
);
1257 char *volatile *ep
= __environ
;
1260 const char *p
= *ep
;
1261 _hurdsig_fault_preemptor
.first
= (long int) p
;
1262 _hurdsig_fault_preemptor
.last
= VM_MAX_ADDRESS
;
1263 if (! strncmp (p
, variable
, len
) && p
[len
] == '=')
1268 valuelen
= strlen (p
);
1269 _hurdsig_fault_preemptor
.last
= (long int) (p
+ valuelen
);
1270 value
= malloc (++valuelen
);
1272 memcpy (value
, p
, valuelen
);
1275 _hurdsig_fault_preemptor
.first
= (long int) ++ep
;
1276 _hurdsig_fault_preemptor
.last
= (long int) (ep
+ 1);
1278 _hurdsig_end_catch_fault ();