1 /* Copyright (C) 1991, 1992, 1993, 1994, 1995 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
16 not, write to the Free Software Foundation, Inc., 675 Mass Ave,
17 Cambridge, MA 02139, 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 /* Linked-list of per-thread signal state. */
43 struct hurd_sigstate *_hurd_sigstates;
45 /* Timeout for RPC's after interrupt_operation. */
46 mach_msg_timeout_t _hurd_interrupted_rpc_timeout = 3000;
49 default_sigaction (struct sigaction actions[NSIG])
53 __sigemptyset (&actions[0].sa_mask);
54 actions[0].sa_flags = SA_RESTART;
55 actions[0].sa_handler = SIG_DFL;
57 for (signo = 1; signo < NSIG; ++signo)
58 actions[signo] = actions[0];
61 struct hurd_sigstate *
62 _hurd_thread_sigstate (thread_t thread)
64 struct hurd_sigstate *ss;
65 __mutex_lock (&_hurd_siglock);
66 for (ss = _hurd_sigstates; ss != NULL; ss = ss->next)
67 if (ss->thread == thread)
71 ss = malloc (sizeof (*ss));
73 __libc_fatal ("hurd: Can't allocate thread sigstate\n");
75 __spin_lock_init (&ss->lock);
77 /* Initialze default state. */
78 __sigemptyset (&ss->blocked);
79 __sigemptyset (&ss->pending);
80 memset (&ss->sigaltstack, 0, sizeof (ss->sigaltstack));
82 ss->intr_port = MACH_PORT_NULL;
85 /* Initialize the sigaction vector from the default signal receiving
86 thread's state, and its from the system defaults. */
87 if (thread == _hurd_sigthread)
88 default_sigaction (ss->actions);
91 struct hurd_sigstate *s;
92 for (s = _hurd_sigstates; s != NULL; s = s->next)
93 if (s->thread == _hurd_sigthread)
97 __spin_lock (&s->lock);
98 memcpy (ss->actions, s->actions, sizeof (s->actions));
99 __spin_unlock (&s->lock);
102 default_sigaction (ss->actions);
105 ss->next = _hurd_sigstates;
106 _hurd_sigstates = ss;
108 __mutex_unlock (&_hurd_siglock);
112 /* Signal delivery itself is on this page. */
115 #include <hurd/crash.h>
116 #include <hurd/paths.h>
119 #include <sys/wait.h>
120 #include "thread_state.h"
121 #include <hurd/msg_server.h>
122 #include <hurd/msg_reply.h> /* For __msg_sig_post_reply. */
124 #include <hurd/interrupt.h>
126 int _hurd_core_limit; /* XXX */
128 /* Call the crash dump server to mummify us before we die.
129 Returns nonzero if a core file was written. */
131 write_corefile (int signo, long int sigcode, int sigerror)
134 mach_port_t coreserver;
135 file_t file, coredir;
139 When we have a protocol to make the server return an error
140 for RLIMIT_FSIZE, then tell the corefile fs server the RLIMIT_CORE
141 value in place of the RLIMIT_FSIZE value. */
143 /* First get a port to the core dumping server. */
144 coreserver = MACH_PORT_NULL;
145 name = _hurdsig_getenv ("CRASHSERVER");
147 coreserver = __file_name_lookup (name, 0, 0);
148 if (coreserver == MACH_PORT_NULL)
149 coreserver = __file_name_lookup (_SERVERS_CRASH, 0, 0);
150 if (coreserver == MACH_PORT_NULL)
153 /* Get a port to the directory where the new core file will reside. */
154 name = _hurdsig_getenv ("COREFILE");
157 coredir = __file_name_split (name, (char **) &name);
158 if (coredir == MACH_PORT_NULL)
160 /* Create the new file, but don't link it into the directory yet. */
161 if (err = __dir_mkfile (coredir, O_WRONLY|O_CREAT,
162 0600 & ~_hurd_umask, /* XXX ? */
166 /* Call the core dumping server to write the core file. */
167 err = __crash_dump_task (coreserver,
169 file, _hurdsig_getenv ("GNUTARGET"),
170 signo, sigcode, sigerror);
171 __mach_port_deallocate (__mach_task_self (), coreserver);
173 /* The core dump into FILE succeeded, so now link it into the
175 err = __dir_link (file, coredir, name);
176 __mach_port_deallocate (__mach_task_self (), file);
177 __mach_port_deallocate (__mach_task_self (), coredir);
182 /* The lowest-numbered thread state flavor value is 1,
183 so we use bit 0 in machine_thread_all_state.set to
184 record whether we have done thread_abort. */
185 #define THREAD_ABORTED 1
187 /* SS->thread is suspended. Abort the thread and get its basic state. */
189 abort_thread (struct hurd_sigstate *ss, struct machine_thread_all_state *state,
190 void (*reply) (void))
192 if (!(state->set & THREAD_ABORTED))
194 error_t err = __thread_abort (ss->thread);
196 /* Clear all thread state flavor set bits, because thread_abort may
197 have changed the state. */
198 state->set = THREAD_ABORTED;
204 machine_get_basic_state (ss->thread, state);
207 /* Find the location of the MiG reply port cell in use by the thread whose
208 state is described by THREAD_STATE. If SIGTHREAD is nonzero, make sure
209 that this location can be set without faulting, or else return NULL. */
212 interrupted_reply_port_location (struct machine_thread_all_state *thread_state,
215 mach_port_t *portloc = (mach_port_t *) __hurd_threadvar_location_from_sp
216 (_HURD_THREADVAR_MIG_REPLY, (void *) thread_state->basic.SP);
218 if (sigthread && _hurdsig_catch_fault (SIGSEGV))
220 assert (_hurdsig_fault_sigcode == (long int) portloc);
221 /* Faulted trying to read the stack. */
225 /* Fault now if this pointer is bogus. */
226 *(volatile mach_port_t *) portloc = *portloc;
229 _hurdsig_end_catch_fault ();
234 #include "intr-msg.h"
236 /* SS->thread is suspended.
238 Abort any interruptible RPC operation the thread is doing.
240 This uses only the constant member SS->thread and the unlocked, atomically
241 set member SS->intr_port, so no locking is needed.
243 If successfully sent an interrupt_operation and therefore the thread should
244 wait for its pending RPC to return (possibly EINTR) before taking the
245 incoming signal, returns the reply port to be received on. Otherwise
246 returns MACH_PORT_NULL.
248 SIGNO is used to find the applicable SA_RESTART bit. If SIGNO is zero,
249 the RPC fails with EINTR instead of restarting (thread_cancel).
251 *STATE_CHANGE is set nonzero if STATE->basic was modified and should
252 be applied back to the thread if it might ever run again, else zero. */
255 _hurdsig_abort_rpcs (struct hurd_sigstate *ss, int signo, int sigthread,
256 struct machine_thread_all_state *state, int *state_change,
257 void (*reply) (void))
259 extern const void _hurd_intr_rpc_msg_in_trap;
260 mach_port_t rcv_port = MACH_PORT_NULL;
261 mach_port_t intr_port;
265 intr_port = ss->intr_port;
266 if (intr_port == MACH_PORT_NULL)
267 /* No interruption needs done. */
268 return MACH_PORT_NULL;
270 /* Abort the thread's kernel context, so any pending message send or
271 receive completes immediately or aborts. */
272 abort_thread (ss, state, reply);
274 if (state->basic.PC < (natural_t) &_hurd_intr_rpc_msg_in_trap)
276 /* The thread is about to do the RPC, but hasn't yet entered
277 mach_msg. Mutate the thread's state so it knows not to try
279 INTR_MSG_BACK_OUT (&state->basic);
280 MACHINE_THREAD_STATE_SET_PC (&state->basic,
281 &_hurd_intr_rpc_msg_in_trap);
282 state->basic.SYSRETURN = MACH_SEND_INTERRUPTED;
285 else if (state->basic.PC == (natural_t) &_hurd_intr_rpc_msg_in_trap &&
286 /* The thread was blocked in the system call. After thread_abort,
287 the return value register indicates what state the RPC was in
289 state->basic.SYSRETURN == MACH_RCV_INTERRUPTED)
291 /* The RPC request message was sent and the thread was waiting for
292 the reply message; now the message receive has been aborted, so
293 the mach_msg call will return MACH_RCV_INTERRUPTED. We must tell
294 the server to interrupt the pending operation. The thread must
295 wait for the reply message before running the signal handler (to
296 guarantee that the operation has finished being interrupted), so
297 our nonzero return tells the trampoline code to finish the message
298 receive operation before running the handler. */
300 mach_port_t *reply = interrupted_reply_port_location (state,
302 error_t err = __interrupt_operation (intr_port);
308 /* The interrupt didn't work.
309 Destroy the receive right the thread is blocked on. */
310 __mach_port_destroy (__mach_task_self (), *reply);
311 *reply = MACH_PORT_NULL;
314 /* The system call return value register now contains
315 MACH_RCV_INTERRUPTED; when mach_msg resumes, it will retry the
316 call. Since we have just destroyed the receive right, the
317 retry will fail with MACH_RCV_INVALID_NAME. Instead, just
318 change the return value here to EINTR so mach_msg will not
319 retry and the EINTR error code will propagate up. */
320 state->basic.SYSRETURN = EINTR;
326 /* All threads whose RPCs were interrupted by the interrupt_operation
327 call above will retry their RPCs unless we clear SS->intr_port.
328 So we clear it for the thread taking a signal when SA_RESTART is
329 clear, so that its call returns EINTR. */
330 if (! signo || !(ss->actions[signo].sa_flags & SA_RESTART))
331 ss->intr_port = MACH_PORT_NULL;
338 /* Abort the RPCs being run by all threads but this one;
339 all other threads should be suspended. If LIVE is nonzero, those
340 threads may run again, so they should be adjusted as necessary to be
341 happy when resumed. STATE is clobbered as a scratch area; its initial
342 contents are ignored, and its contents on return are not useful. */
345 abort_all_rpcs (int signo, struct machine_thread_all_state *state, int live)
347 /* We can just loop over the sigstates. Any thread doing something
348 interruptible must have one. We needn't bother locking because all
349 other threads are stopped. */
351 struct hurd_sigstate *ss;
353 mach_port_t *reply_ports;
355 /* First loop over the sigstates to count them.
356 We need to know how big a vector we will need for REPLY_PORTS. */
358 for (ss = _hurd_sigstates; ss != NULL; ss = ss->next)
361 reply_ports = alloca (nthreads * sizeof *reply_ports);
364 for (ss = _hurd_sigstates; ss != NULL; ss = ss->next)
365 if (ss->thread == _hurd_msgport_thread)
366 reply_ports[nthreads++] = MACH_PORT_NULL;
370 state->set = 0; /* Reset scratch area. */
372 /* Abort any operation in progress with interrupt_operation.
373 Record the reply port the thread is waiting on.
374 We will wait for all the replies below. */
375 reply_ports[nthreads++] = _hurdsig_abort_rpcs (ss, signo, 1,
376 state, &state_changed,
378 if (state_changed && live)
379 /* Aborting the RPC needed to change this thread's state,
380 and it might ever run again. So write back its state. */
381 __thread_set_state (ss->thread, MACHINE_THREAD_STATE_FLAVOR,
382 (natural_t *) &state->basic,
383 MACHINE_THREAD_STATE_COUNT);
386 /* Wait for replies from all the successfully interrupted RPCs. */
387 while (nthreads-- > 0)
388 if (reply_ports[nthreads] != MACH_PORT_NULL)
391 mach_msg_header_t head;
392 err = __mach_msg (&head, MACH_RCV_MSG|MACH_RCV_TIMEOUT, 0, sizeof head,
393 reply_ports[nthreads],
394 _hurd_interrupted_rpc_timeout, MACH_PORT_NULL);
397 case MACH_RCV_TIMED_OUT:
398 case MACH_RCV_TOO_LARGE:
408 struct hurd_signal_preempt *_hurd_signal_preempt[NSIG];
409 struct mutex _hurd_signal_preempt_lock;
411 /* Mask of stop signals. */
412 #define STOPSIGS (sigmask (SIGTTIN) | sigmask (SIGTTOU) | \
413 sigmask (SIGSTOP) | sigmask (SIGTSTP))
415 /* Deliver a signal. SS is not locked. */
417 _hurd_internal_post_signal (struct hurd_sigstate *ss,
418 int signo, long int sigcode, int sigerror,
419 mach_port_t reply_port,
420 mach_msg_type_name_t reply_port_type,
424 struct machine_thread_all_state thread_state;
425 enum { stop, ignore, core, term, handle } act;
426 sighandler_t handler;
427 struct hurd_signal_preempt *pe;
428 sighandler_t (*preempt) (thread_t, int, long int, int) = NULL;
432 /* Reply to this sig_post message. */
433 __typeof (__msg_sig_post_reply) *reply_rpc
434 = (untraced ? __msg_sig_post_untraced_reply : __msg_sig_post_reply);
438 if (reply_port == MACH_PORT_NULL)
440 err = (*reply_rpc) (reply_port, reply_port_type, 0);
441 reply_port = MACH_PORT_NULL;
442 if (err != MACH_SEND_INVALID_DEST) /* Ignore dead reply port. */
446 /* Mark the signal as pending. */
447 void mark_pending (void)
449 __sigaddset (&ss->pending, signo);
450 /* Save the code to be given to the handler when SIGNO is
452 ss->pending_data[signo].code = sigcode;
453 ss->pending_data[signo].error = sigerror;
456 /* Suspend the process with SIGNO. */
459 /* Stop all other threads and mark ourselves stopped. */
462 /* Hold the siglock while stopping other threads to be
463 sure it is not held by another thread afterwards. */
464 __mutex_lock (&_hurd_siglock);
465 __proc_dostop (port, _hurd_msgport_thread);
466 __mutex_unlock (&_hurd_siglock);
467 abort_all_rpcs (signo, &thread_state, 1);
469 __proc_mark_stop (port, signo);
473 /* Resume the process after a suspension. */
476 /* Resume the process from being stopped. */
478 mach_msg_type_number_t nthreads, i;
484 /* Tell the proc server we are continuing. */
485 __USEPORT (PROC, __proc_mark_cont (port));
486 /* Fetch ports to all our threads and resume them. */
487 err = __task_threads (__mach_task_self (), &threads, &nthreads);
489 for (i = 0; i < nthreads; ++i)
491 if (threads[i] != _hurd_msgport_thread &&
492 (act != handle || threads[i] != ss->thread))
494 err = __thread_resume (threads[i]);
497 err = __mach_port_deallocate (__mach_task_self (),
501 __vm_deallocate (__mach_task_self (),
502 (vm_address_t) threads,
503 nthreads * sizeof *threads);
505 /* The thread that will run the handler is already suspended. */
512 /* This is PTRACE_CONTINUE. */
515 /* This call is just to check for pending signals. */
516 __spin_lock (&ss->lock);
517 goto check_pending_signals;
522 thread_state.set = 0; /* We know nothing. */
524 /* Check for a preempted signal. Preempted signals
525 can arrive during critical sections. */
526 __mutex_lock (&_hurd_signal_preempt_lock);
527 for (pe = _hurd_signal_preempt[signo]; pe != NULL; pe = pe->next)
528 if (pe->handler && sigcode >= pe->first && sigcode <= pe->last)
530 preempt = pe->handler;
533 __mutex_unlock (&_hurd_signal_preempt_lock);
537 /* Let the preempting handler examine the thread.
538 If it returns SIG_DFL, we run the normal handler;
539 otherwise we use the handler it returns. */
540 handler = (*preempt) (ss->thread, signo, sigcode, sigerror);
544 if (handler != SIG_DFL)
545 /* Run the preemption-provided handler. */
549 /* No preemption. Do normal handling. */
551 __spin_lock (&ss->lock);
553 if (!untraced && (_hurd_exec_flags & EXEC_TRACED))
555 /* We are being traced. Stop to tell the debugger of the signal. */
557 /* Already stopped. Mark the signal as pending;
558 when resumed, we will notice it and stop again. */
562 __spin_unlock (&ss->lock);
567 handler = ss->actions[signo].sa_handler;
569 if (handler == SIG_DFL)
570 /* Figure out the default action for this signal. */
574 /* A sig_post msg with SIGNO==0 is sent to
575 tell us to check for pending signals. */
607 if (_hurd_pgrp == _hurd_pid)
609 /* We are the process group leader. Since there is no
610 user-specified handler for SIGINFO, we use a default one
611 which prints something interesting. We use the normal
612 handler mechanism instead of just doing it here to avoid
613 the signal thread faulting or blocking in this
614 potentially hairy operation. */
616 handler = _hurd_siginfo_handler;
626 else if (handler == SIG_IGN)
631 if (__sigmask (signo) & STOPSIGS)
632 /* Stop signals clear a pending SIGCONT even if they
633 are handled or ignored (but not if preempted). */
634 ss->pending &= ~sigmask (SIGCONT);
637 if (signo == SIGCONT)
638 /* Even if handled or ignored (but not preempted), SIGCONT clears
639 stop signals and resumes the process. */
640 ss->pending &= ~STOPSIGS;
642 if (_hurd_stopped && act != stop && (untraced || signo == SIGCONT))
647 if (_hurd_orphaned && act == stop &&
648 (__sigmask (signo) & (__sigmask (SIGTTIN) | __sigmask (SIGTTOU) |
649 __sigmask (SIGTSTP))))
651 /* If we would ordinarily stop for a job control signal, but we are
652 orphaned so noone would ever notice and continue us again, we just
653 quietly die, alone and in the dark. */
659 /* Handle receipt of a blocked signal, or any signal while stopped. */
660 if (__sigismember (&ss->blocked, signo) ||
661 (signo != SIGKILL && _hurd_stopped))
667 /* Perform the chosen action for the signal. */
673 /* We are already stopped, but receiving an untraced stop
674 signal. Instead of resuming and suspending again, just
675 notify the proc server of the new stop signal. */
676 error_t err = __USEPORT (PROC, __proc_mark_stop (port, signo));
680 /* Suspend the process. */
685 /* Nobody cares about this signal. */
689 /* We got a fault setting up the stack frame for the handler.
690 Nothing to do but die; BSD gets SIGILL in this case. */
691 sigcode = signo; /* XXX ? */
696 case term: /* Time to die. */
697 case core: /* And leave a rotting corpse. */
698 /* Have the proc server stop all other threads in our task. */
699 err = __USEPORT (PROC, __proc_dostop (port, _hurd_msgport_thread));
701 /* No more user instructions will be executed.
702 The signal can now be considered delivered. */
704 /* Abort all server operations now in progress. */
705 abort_all_rpcs (signo, &thread_state, 0);
708 int status = W_EXITCODE (0, signo);
709 /* Do a core dump if desired. Only set the wait status bit saying we
710 in fact dumped core if the operation was actually successful. */
711 if (act == core && write_corefile (signo, sigcode, sigerror))
713 /* Tell proc how we died and then stick the saber in the gut. */
719 /* Call a handler for this signal. */
721 struct sigcontext *scp, ocontext;
722 int wait_for_reply, state_changed;
724 /* Stop the thread and abort its pending RPC operations. */
727 err = __thread_suspend (ss->thread);
731 /* Abort the thread's kernel context, so any pending message send
732 or receive completes immediately or aborts. If an interruptible
733 RPC is in progress, abort_rpcs will do this. But we must always
734 do it before fetching the thread's state, because
735 thread_get_state is never kosher before thread_abort. */
736 abort_thread (ss, &thread_state, NULL);
740 /* We have a previous sigcontext that sigreturn was about
741 to restore when another signal arrived. */
745 if (_hurdsig_catch_fault (SIGSEGV))
747 assert (_hurdsig_fault_sigcode >= (long int) ss->context &&
748 _hurdsig_fault_sigcode < (long int) (ss->context + 1));
749 /* We faulted reading the thread's stack. Forget that
750 context and pretend it wasn't there. It almost
751 certainly crash if this handler returns, but that's it's
757 /* Copy the context from the thread's stack before
758 we start diddling the stack to set up the handler. */
759 ocontext = *ss->context;
760 ss->context = &ocontext;
762 _hurdsig_end_catch_fault ();
764 if (! machine_get_basic_state (ss->thread, &thread_state))
766 loc = interrupted_reply_port_location (&thread_state, 1);
767 if (loc && *loc != MACH_PORT_NULL)
768 /* This is the reply port for the context which called
769 sigreturn. Since we are abandoning that context entirely
770 and restoring SS->context instead, destroy this port. */
771 __mach_port_destroy (__mach_task_self (), *loc);
773 /* The thread was in sigreturn, not in any interruptible RPC. */
776 assert (! ss->critical_section);
781 = (_hurdsig_abort_rpcs (ss, signo, 1,
782 &thread_state, &state_changed,
786 if (ss->critical_section)
788 /* The thread is in a critical section. Mark the signal as
789 pending. When it finishes the critical section, it will
790 check for pending signals. */
792 assert (! state_changed);
793 __thread_resume (ss->thread);
798 /* Call the machine-dependent function to set the thread up
799 to run the signal handler, and preserve its old context. */
800 scp = _hurd_setup_sighandler (ss, handler,
802 wait_for_reply, &thread_state);
806 /* Set the machine-independent parts of the signal context. */
809 /* Fetch the thread variable for the MiG reply port,
810 and set it to MACH_PORT_NULL. */
811 mach_port_t *loc = interrupted_reply_port_location (&thread_state,
815 scp->sc_reply_port = *loc;
816 *loc = MACH_PORT_NULL;
819 scp->sc_reply_port = MACH_PORT_NULL;
821 /* Save the intr_port in use by the interrupted code,
822 and clear the cell before running the trampoline. */
823 scp->sc_intr_port = ss->intr_port;
824 ss->intr_port = MACH_PORT_NULL;
828 /* After the handler runs we will restore to the state in
829 SS->context, not the state of the thread now. So restore
830 that context's reply port and intr port. */
832 scp->sc_reply_port = ss->context->sc_reply_port;
833 scp->sc_intr_port = ss->context->sc_intr_port;
839 /* Backdoor extra argument to signal handler. */
840 scp->sc_error = sigerror;
842 /* Block SIGNO and requested signals while running the handler. */
843 scp->sc_mask = ss->blocked;
844 ss->blocked |= __sigmask (signo) | ss->actions[signo].sa_mask;
846 /* Start the thread running the handler (or possibly waiting for an
847 RPC reply before running the handler). */
848 err = __thread_set_state (ss->thread, MACHINE_THREAD_STATE_FLAVOR,
849 (natural_t *) &thread_state.basic,
850 MACHINE_THREAD_STATE_COUNT);
852 err = __thread_resume (ss->thread);
854 thread_state.set = 0; /* Everything we know is now wrong. */
859 /* The signal has either been ignored or is now being handled. We can
860 consider it delivered and reply to the killer. */
863 /* We get here unless the signal was fatal. We still hold SS->lock.
864 Check for pending signals, and loop to post them. */
866 /* Return nonzero if SS has any signals pending we should worry about.
867 We don't worry about any pending signals if we are stopped, nor if
868 SS is in a critical section. We are guaranteed to get a sig_post
869 message before any of them become deliverable: either the SIGCONT
870 signal, or a sig_post with SIGNO==0 as an explicit poll when the
871 thread finishes its critical section. */
872 inline int signals_pending (void)
874 if (_hurd_stopped || ss->critical_section)
876 return pending = ss->pending & ~ss->blocked;
879 check_pending_signals:
882 if (signals_pending ())
885 for (signo = 1; signo < NSIG; ++signo)
886 if (__sigismember (&pending, signo))
888 __sigdelset (&ss->pending, signo);
889 sigcode = ss->pending_data[signo].code;
890 sigerror = ss->pending_data[signo].error;
891 __spin_unlock (&ss->lock);
896 /* No pending signals left undelivered for this thread.
897 If we were sent signal 0, we need to check for pending
898 signals for all threads. */
901 __spin_unlock (&ss->lock);
902 __mutex_lock (&_hurd_siglock);
903 for (ss = _hurd_sigstates; ss != NULL; ss = ss->next)
905 __spin_lock (&ss->lock);
906 if (signals_pending ())
908 __spin_unlock (&ss->lock);
910 __mutex_unlock (&_hurd_siglock);
914 /* No more signals pending; SS->lock is still locked.
915 Wake up any sigsuspend call that is blocking SS->thread. */
916 if (ss->suspended != MACH_PORT_NULL)
918 /* There is a sigsuspend waiting. Tell it to wake up. */
920 mach_msg_header_t msg;
921 err = __mach_port_insert_right (__mach_task_self (),
922 ss->suspended, ss->suspended,
923 MACH_MSG_TYPE_MAKE_SEND);
925 msg.msgh_bits = MACH_MSGH_BITS (MACH_MSG_TYPE_MOVE_SEND, 0);
926 msg.msgh_remote_port = ss->suspended;
927 msg.msgh_local_port = MACH_PORT_NULL;
928 /* These values do not matter. */
929 msg.msgh_id = 8675309; /* Jenny, Jenny. */
930 msg.msgh_seqno = 17; /* Random. */
931 ss->suspended = MACH_PORT_NULL;
932 err = __mach_msg (&msg, MACH_SEND_MSG, sizeof msg, 0,
933 MACH_PORT_NULL, MACH_MSG_TIMEOUT_NONE,
937 __spin_unlock (&ss->lock);
941 /* All pending signals delivered to all threads.
942 Now we can send the reply message even for signal 0. */
946 /* Decide whether REFPORT enables the sender to send us a SIGNO signal.
947 Returns zero if so, otherwise the error code to return to the sender. */
950 signal_allowed (int signo, mach_port_t refport)
952 if (signo < 0 || signo >= NSIG)
955 if (refport == __mach_task_self ())
956 /* Can send any signal. */
959 /* Avoid needing to check for this below. */
960 if (refport == MACH_PORT_NULL)
972 /* Job control signals can be sent by the controlling terminal. */
973 if (__USEPORT (CTTYID, port == refport))
979 /* A continue signal can be sent by anyone in the session. */
980 mach_port_t sessport;
981 if (! __USEPORT (PROC, __proc_getsidport (port, &sessport)))
983 __mach_port_deallocate (__mach_task_self (), sessport);
984 if (refport == sessport)
993 /* Any io object a file descriptor refers to might send us
994 one of these signals using its async ID port for REFPORT.
996 This is pretty wide open; it is not unlikely that some random
997 process can at least open for reading something we have open,
998 get its async ID port, and send us a spurious SIGIO or SIGURG
999 signal. But BSD is actually wider open than that!--you can set
1000 the owner of an io object to any process or process group
1001 whatsoever and send them gratuitous signals.
1003 Someday we could implement some reasonable scheme for
1004 authorizing SIGIO and SIGURG signals properly. */
1007 __mutex_lock (&_hurd_dtable_lock);
1008 for (d = 0; (unsigned int) d < (unsigned int) _hurd_dtablesize; ++d)
1010 struct hurd_userlink ulink;
1012 mach_port_t asyncid;
1013 if (_hurd_dtable[d] == NULL)
1015 port = _hurd_port_get (&_hurd_dtable[d]->port, &ulink);
1016 if (! __io_get_icky_async_id (port, &asyncid))
1018 if (refport == asyncid)
1019 /* Break out of the loop on the next iteration. */
1021 __mach_port_deallocate (__mach_task_self (), asyncid);
1023 _hurd_port_free (&_hurd_dtable[d]->port, &ulink, port);
1025 /* If we found a lucky winner, we've set D to -1 in the loop. */
1031 /* If this signal is legit, we have done `goto win' by now.
1032 When we return the error, mig deallocates REFPORT. */
1036 /* Deallocate the REFPORT send right; we are done with it. */
1037 __mach_port_deallocate (__mach_task_self (), refport);
1042 /* Implement the sig_post RPC from <hurd/msg.defs>;
1043 sent when someone wants us to get a signal. */
1045 _S_msg_sig_post (mach_port_t me,
1046 mach_port_t reply_port, mach_msg_type_name_t reply_port_type,
1048 mach_port_t refport)
1052 if (err = signal_allowed (signo, refport))
1055 /* Post the signal to the designated signal-receiving thread. This will
1056 reply when the signal can be considered delivered. */
1057 _hurd_internal_post_signal (_hurd_thread_sigstate (_hurd_sigthread),
1058 signo, 0, 0, reply_port, reply_port_type,
1059 0); /* Stop if traced. */
1061 return MIG_NO_REPLY; /* Already replied. */
1064 /* Implement the sig_post_untraced RPC from <hurd/msg.defs>;
1065 sent when the debugger wants us to really get a signal
1066 even if we are traced. */
1068 _S_msg_sig_post_untraced (mach_port_t me,
1069 mach_port_t reply_port,
1070 mach_msg_type_name_t reply_port_type,
1072 mach_port_t refport)
1076 if (err = signal_allowed (signo, refport))
1079 /* Post the signal to the designated signal-receiving thread. This will
1080 reply when the signal can be considered delivered. */
1081 _hurd_internal_post_signal (_hurd_thread_sigstate (_hurd_sigthread),
1082 signo, 0, 0, reply_port, reply_port_type,
1083 1); /* Untraced flag. */
1085 return MIG_NO_REPLY; /* Already replied. */
1088 extern void __mig_init (void *);
1090 #include <mach/task_special_ports.h>
1092 /* Initialize the message port and _hurd_sigthread and start the signal
1096 _hurdsig_init (void)
1099 vm_size_t stacksize;
1101 __mutex_init (&_hurd_siglock);
1103 err = __mach_port_allocate (__mach_task_self (),
1104 MACH_PORT_RIGHT_RECEIVE,
1106 assert_perror (err);
1108 /* Make a send right to the signal port. */
1109 err = __mach_port_insert_right (__mach_task_self (),
1112 MACH_MSG_TYPE_MAKE_SEND);
1113 assert_perror (err);
1115 /* Set the default thread to receive task-global signals
1116 to this one, the main (first) user thread. */
1117 _hurd_sigthread = __mach_thread_self ();
1119 /* Start the signal thread listening on the message port. */
1121 err = __thread_create (__mach_task_self (), &_hurd_msgport_thread);
1122 assert_perror (err);
1124 stacksize = __vm_page_size * 4; /* Small stack for signal thread. */
1125 err = __mach_setup_thread (__mach_task_self (), _hurd_msgport_thread,
1126 _hurd_msgport_receive,
1127 (vm_address_t *) &__hurd_sigthread_stack_base,
1129 assert_perror (err);
1131 __hurd_sigthread_stack_end = __hurd_sigthread_stack_base + stacksize;
1132 __hurd_sigthread_variables =
1133 malloc (__hurd_threadvar_max * sizeof (unsigned long int));
1134 if (__hurd_sigthread_variables == NULL)
1135 __libc_fatal ("hurd: Can't allocate thread variables for signal thread\n");
1137 /* Reinitialize the MiG support routines so they will use a per-thread
1138 variable for the cached reply port. */
1139 __mig_init ((void *) __hurd_sigthread_stack_base);
1141 err = __thread_resume (_hurd_msgport_thread);
1142 assert_perror (err);
1144 /* Receive exceptions on the signal port. */
1145 __task_set_special_port (__mach_task_self (),
1146 TASK_EXCEPTION_PORT, _hurd_msgport);
1149 /* Reauthenticate with the proc server. */
1152 reauth_proc (mach_port_t new)
1154 mach_port_t ref, ignore;
1156 ref = __mach_reply_port ();
1157 if (! HURD_PORT_USE (&_hurd_ports[INIT_PORT_PROC],
1158 __proc_reauthenticate (port, ref,
1159 MACH_MSG_TYPE_MAKE_SEND) ||
1160 __auth_user_authenticate (new, port, ref,
1161 MACH_MSG_TYPE_MAKE_SEND,
1163 && ignore != MACH_PORT_NULL)
1164 __mach_port_deallocate (__mach_task_self (), ignore);
1165 __mach_port_destroy (__mach_task_self (), ref);
1167 (void) &reauth_proc; /* Silence compiler warning. */
1169 text_set_element (_hurd_reauth_hook, reauth_proc);
1171 /* Like `getenv', but safe for the signal thread to run.
1172 If the environment is trashed, this will just return NULL. */
1175 _hurdsig_getenv (const char *variable)
1177 if (_hurdsig_catch_fault (SIGSEGV))
1178 /* We bombed in getenv. */
1182 const char *value = getenv (variable);
1183 /* Fault now if VALUE is a bogus string. */
1184 (void) strlen (value);
1185 _hurdsig_end_catch_fault ();