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28f540f4 RM |
1 | /* Copyright (C) 1991, 1992, 1993, 1994, 1995 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 <stdlib.h> | |
20 | #include <stdio.h> | |
21 | #include <hurd.h> | |
22 | #include <hurd/signal.h> | |
23 | #include <cthreads.h> /* For `struct mutex'. */ | |
24 | #include <string.h> | |
25 | #include "hurdfault.h" | |
26 | #include "hurdmalloc.h" /* XXX */ | |
27 | ||
28 | const char *_hurdsig_getenv (const char *); | |
29 | ||
30 | struct mutex _hurd_siglock; | |
31 | int _hurd_stopped; | |
32 | ||
33 | /* Port that receives signals and other miscellaneous messages. */ | |
34 | mach_port_t _hurd_msgport; | |
35 | ||
36 | /* Thread listening on it. */ | |
37 | thread_t _hurd_msgport_thread; | |
38 | ||
39 | /* Thread which receives task-global signals. */ | |
40 | thread_t _hurd_sigthread; | |
41 | ||
42 | /* Linked-list of per-thread signal state. */ | |
43 | struct hurd_sigstate *_hurd_sigstates; | |
54da5be3 RM |
44 | |
45 | /* Timeout for RPC's after interrupt_operation. */ | |
46 | mach_msg_timeout_t _hurd_interrupted_rpc_timeout = 3000; | |
28f540f4 RM |
47 | \f |
48 | static void | |
49 | default_sigaction (struct sigaction actions[NSIG]) | |
50 | { | |
51 | int signo; | |
52 | ||
53 | __sigemptyset (&actions[0].sa_mask); | |
54 | actions[0].sa_flags = SA_RESTART; | |
55 | actions[0].sa_handler = SIG_DFL; | |
56 | ||
57 | for (signo = 1; signo < NSIG; ++signo) | |
58 | actions[signo] = actions[0]; | |
59 | } | |
60 | ||
61 | struct hurd_sigstate * | |
62 | _hurd_thread_sigstate (thread_t thread) | |
63 | { | |
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) | |
b96bdcd7 | 68 | break; |
28f540f4 RM |
69 | if (ss == NULL) |
70 | { | |
71 | ss = malloc (sizeof (*ss)); | |
72 | if (ss == NULL) | |
73 | __libc_fatal ("hurd: Can't allocate thread sigstate\n"); | |
74 | ss->thread = thread; | |
75 | __spin_lock_init (&ss->lock); | |
76 | ||
77 | /* Initialze default state. */ | |
78 | __sigemptyset (&ss->blocked); | |
79 | __sigemptyset (&ss->pending); | |
80 | memset (&ss->sigaltstack, 0, sizeof (ss->sigaltstack)); | |
81 | ss->suspended = 0; | |
28f540f4 RM |
82 | ss->intr_port = MACH_PORT_NULL; |
83 | ss->context = NULL; | |
84 | ||
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); | |
89 | else | |
90 | { | |
91 | struct hurd_sigstate *s; | |
92 | for (s = _hurd_sigstates; s != NULL; s = s->next) | |
93 | if (s->thread == _hurd_sigthread) | |
94 | break; | |
95 | if (s) | |
96 | { | |
97 | __spin_lock (&s->lock); | |
98 | memcpy (ss->actions, s->actions, sizeof (s->actions)); | |
99 | __spin_unlock (&s->lock); | |
100 | } | |
101 | else | |
102 | default_sigaction (ss->actions); | |
103 | } | |
104 | ||
105 | ss->next = _hurd_sigstates; | |
106 | _hurd_sigstates = ss; | |
107 | } | |
108 | __mutex_unlock (&_hurd_siglock); | |
109 | return ss; | |
110 | } | |
111 | \f | |
112 | /* Signal delivery itself is on this page. */ | |
113 | ||
114 | #include <hurd/fd.h> | |
115 | #include <hurd/core.h> | |
116 | #include <hurd/paths.h> | |
117 | #include <setjmp.h> | |
118 | #include <fcntl.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. */ | |
123 | #include <assert.h> | |
124 | #include <hurd/interrupt.h> | |
125 | ||
126 | int _hurd_core_limit; /* XXX */ | |
127 | ||
128 | /* Call the core server to mummify us before we die. | |
129 | Returns nonzero if a core file was written. */ | |
130 | static int | |
131 | write_corefile (int signo, long int sigcode, int sigerror) | |
132 | { | |
133 | error_t err; | |
134 | mach_port_t coreserver; | |
135 | file_t file, coredir; | |
136 | const char *name; | |
137 | ||
138 | /* XXX RLIMIT_CORE: | |
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. */ | |
142 | ||
143 | /* First get a port to the core dumping server. */ | |
144 | coreserver = MACH_PORT_NULL; | |
145 | name = _hurdsig_getenv ("CORESERVER"); | |
146 | if (name != NULL) | |
147 | coreserver = __file_name_lookup (name, 0, 0); | |
148 | if (coreserver == MACH_PORT_NULL) | |
149 | coreserver = __file_name_lookup (_SERVERS_CORE, 0, 0); | |
150 | if (coreserver == MACH_PORT_NULL) | |
151 | return 0; | |
152 | ||
153 | /* Get a port to the directory where the new core file will reside. */ | |
154 | name = _hurdsig_getenv ("COREFILE"); | |
155 | if (name == NULL) | |
156 | name = "core"; | |
157 | coredir = __file_name_split (name, (char **) &name); | |
158 | if (coredir == MACH_PORT_NULL) | |
159 | return 0; | |
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 ? */ | |
163 | &file)) | |
164 | return 0; | |
165 | ||
166 | /* Call the core dumping server to write the core file. */ | |
167 | err = __core_dump_task (coreserver, | |
168 | __mach_task_self (), | |
169 | file, _hurdsig_getenv ("GNUTARGET"), | |
170 | signo, sigcode, sigerror); | |
171 | __mach_port_deallocate (__mach_task_self (), coreserver); | |
172 | if (! err) | |
173 | /* The core dump into FILE succeeded, so now link it into the | |
174 | directory. */ | |
175 | err = __dir_link (file, coredir, name); | |
176 | __mach_port_deallocate (__mach_task_self (), file); | |
177 | __mach_port_deallocate (__mach_task_self (), coredir); | |
178 | return !err; | |
179 | } | |
180 | ||
181 | ||
182 | /* Send a sig_post reply message if it hasn't already been sent. */ | |
183 | static inline void | |
184 | post_reply (mach_port_t *reply_port, mach_msg_type_name_t reply_port_type, | |
185 | int untraced, | |
186 | error_t result) | |
187 | { | |
b96bdcd7 | 188 | error_t err; |
28f540f4 RM |
189 | if (reply_port == NULL || *reply_port == MACH_PORT_NULL) |
190 | return; | |
b96bdcd7 | 191 | err = (untraced ? __msg_sig_post_untraced_reply : __msg_sig_post_reply) |
28f540f4 RM |
192 | (*reply_port, reply_port_type, result); |
193 | *reply_port = MACH_PORT_NULL; | |
b96bdcd7 RM |
194 | if (err != MACH_SEND_INVALID_DEST) /* Ignore dead reply port. */ |
195 | assert_perror (err); | |
28f540f4 RM |
196 | } |
197 | ||
198 | ||
199 | /* The lowest-numbered thread state flavor value is 1, | |
200 | so we use bit 0 in machine_thread_all_state.set to | |
201 | record whether we have done thread_abort. */ | |
202 | #define THREAD_ABORTED 1 | |
203 | ||
204 | /* SS->thread is suspended. Abort the thread and get its basic state. If | |
205 | REPLY_PORT is not NULL, send a reply on *REPLY_PORT after aborting the | |
206 | thread. */ | |
207 | static void | |
208 | abort_thread (struct hurd_sigstate *ss, struct machine_thread_all_state *state, | |
209 | mach_port_t *reply_port, mach_msg_type_name_t reply_port_type, | |
210 | int untraced) | |
211 | { | |
212 | if (!(state->set & THREAD_ABORTED)) | |
213 | { | |
b96bdcd7 RM |
214 | error_t err = __thread_abort (ss->thread); |
215 | assert_perror (err); | |
28f540f4 RM |
216 | /* Clear all thread state flavor set bits, because thread_abort may |
217 | have changed the state. */ | |
218 | state->set = THREAD_ABORTED; | |
219 | } | |
220 | ||
221 | if (reply_port) | |
222 | post_reply (reply_port, reply_port_type, untraced, 0); | |
223 | ||
224 | machine_get_basic_state (ss->thread, state); | |
225 | } | |
226 | ||
227 | /* Find the location of the MiG reply port cell in use by the thread whose | |
54da5be3 RM |
228 | state is described by THREAD_STATE. If SIGTHREAD is nonzero, make sure |
229 | that this location can be set without faulting, or else return NULL. */ | |
28f540f4 RM |
230 | |
231 | static mach_port_t * | |
54da5be3 RM |
232 | interrupted_reply_port_location (struct machine_thread_all_state *thread_state, |
233 | int sigthread) | |
28f540f4 RM |
234 | { |
235 | mach_port_t *portloc = (mach_port_t *) __hurd_threadvar_location_from_sp | |
236 | (_HURD_THREADVAR_MIG_REPLY, (void *) thread_state->basic.SP); | |
237 | ||
54da5be3 | 238 | if (sigthread && _hurdsig_catch_fault (SIGSEGV)) |
28f540f4 RM |
239 | { |
240 | assert (_hurdsig_fault_sigcode == (long int) portloc); | |
241 | /* Faulted trying to read the stack. */ | |
242 | return NULL; | |
243 | } | |
244 | ||
245 | /* Fault now if this pointer is bogus. */ | |
246 | *(volatile mach_port_t *) portloc = *portloc; | |
247 | ||
54da5be3 RM |
248 | if (sigthread) |
249 | _hurdsig_end_catch_fault (); | |
28f540f4 RM |
250 | |
251 | return portloc; | |
252 | } | |
253 | ||
254 | ||
255 | /* SS->thread is suspended. | |
256 | ||
257 | Abort any interruptible RPC operation the thread is doing. | |
258 | ||
259 | This uses only the constant member SS->thread and the unlocked, atomically | |
260 | set member SS->intr_port, so no locking is needed. | |
261 | ||
262 | If successfully sent an interrupt_operation and therefore the thread should | |
263 | wait for its pending RPC to return (possibly EINTR) before taking the | |
264 | incoming signal, returns the reply port to be received on. Otherwise | |
265 | returns MACH_PORT_NULL. | |
266 | ||
267 | *STATE_CHANGE is set nonzero if STATE->basic was modified and should | |
268 | be applied back to the thread if it might ever run again, else zero. */ | |
269 | ||
270 | static mach_port_t | |
54da5be3 RM |
271 | _hurdsig_abort_rpcs (struct hurd_sigstate *ss, int signo, int sigthread, |
272 | struct machine_thread_all_state *state, int *state_change, | |
273 | mach_port_t *reply_port, | |
274 | mach_msg_type_name_t reply_port_type, | |
275 | int untraced) | |
28f540f4 | 276 | { |
54da5be3 RM |
277 | extern const void _hurd_intr_rpc_msg_do_trap, _hurd_intr_rpc_msg_in_trap; |
278 | mach_port_t rcv_port = MACH_PORT_NULL; | |
28f540f4 RM |
279 | mach_port_t intr_port; |
280 | ||
281 | *state_change = 0; | |
282 | ||
283 | intr_port = ss->intr_port; | |
284 | if (intr_port == MACH_PORT_NULL) | |
285 | /* No interruption needs done. */ | |
286 | return MACH_PORT_NULL; | |
287 | ||
288 | /* Abort the thread's kernel context, so any pending message send or | |
289 | receive completes immediately or aborts. */ | |
290 | abort_thread (ss, state, reply_port, reply_port_type, untraced); | |
291 | ||
54da5be3 | 292 | if (state->basic.PC < (natural_t) &_hurd_intr_rpc_msg_in_trap) |
28f540f4 | 293 | { |
54da5be3 RM |
294 | /* The thread is about to do the RPC, but hasn't yet entered |
295 | mach_msg. Mutate the thread's state so it knows not to try | |
296 | the RPC. */ | |
297 | MACHINE_THREAD_STATE_SET_PC (&state->basic, | |
298 | &_hurd_intr_rpc_msg_in_trap); | |
299 | state->basic.SYSRETURN = MACH_SEND_INTERRUPTED; | |
300 | *state_change = 1; | |
28f540f4 | 301 | } |
54da5be3 RM |
302 | else if (state->basic.PC == (natural_t) &_hurd_intr_rpc_msg_in_trap && |
303 | /* The thread was blocked in the system call. After thread_abort, | |
304 | the return value register indicates what state the RPC was in | |
305 | when interrupted. */ | |
306 | state->basic.SYSRETURN == MACH_RCV_INTERRUPTED) | |
307 | { | |
308 | /* The RPC request message was sent and the thread was waiting for | |
309 | the reply message; now the message receive has been aborted, so | |
310 | the mach_msg call will return MACH_RCV_INTERRUPTED. We must tell | |
311 | the server to interrupt the pending operation. The thread must | |
312 | wait for the reply message before running the signal handler (to | |
313 | guarantee that the operation has finished being interrupted), so | |
314 | our nonzero return tells the trampoline code to finish the message | |
315 | receive operation before running the handler. */ | |
316 | ||
317 | mach_port_t *reply = interrupted_reply_port_location (state, | |
318 | sigthread); | |
319 | error_t err = __interrupt_operation (intr_port); | |
320 | ||
321 | if (err) | |
322 | { | |
323 | if (reply) | |
324 | { | |
325 | /* The interrupt didn't work. | |
326 | Destroy the receive right the thread is blocked on. */ | |
327 | __mach_port_destroy (__mach_task_self (), *reply); | |
328 | *reply = MACH_PORT_NULL; | |
329 | } | |
28f540f4 | 330 | |
54da5be3 RM |
331 | /* The system call return value register now contains |
332 | MACH_RCV_INTERRUPTED; when mach_msg resumes, it will retry the | |
333 | call. Since we have just destroyed the receive right, the | |
334 | retry will fail with MACH_RCV_INVALID_NAME. Instead, just | |
335 | change the return value here to EINTR so mach_msg will not | |
336 | retry and the EINTR error code will propagate up. */ | |
337 | state->basic.SYSRETURN = EINTR; | |
338 | *state_change = 1; | |
339 | } | |
340 | else if (reply) | |
341 | rcv_port = *reply; | |
342 | ||
343 | /* All threads whose RPCs were interrupted by the interrupt_operation | |
344 | call above will retry their RPCs unless we clear SS->intr_port. | |
345 | So we clear it for the thread taking a signal when SA_RESTART is | |
346 | clear, so that its call returns EINTR. */ | |
347 | if (! signo || !(ss->actions[signo].sa_flags & SA_RESTART)) | |
348 | ss->intr_port = MACH_PORT_NULL; | |
349 | } | |
28f540f4 | 350 | |
54da5be3 | 351 | return rcv_port; |
28f540f4 RM |
352 | } |
353 | ||
54da5be3 | 354 | |
28f540f4 RM |
355 | /* Abort the RPCs being run by all threads but this one; |
356 | all other threads should be suspended. If LIVE is nonzero, those | |
357 | threads may run again, so they should be adjusted as necessary to be | |
358 | happy when resumed. STATE is clobbered as a scratch area; its initial | |
359 | contents are ignored, and its contents on return are not useful. */ | |
360 | ||
361 | static void | |
362 | abort_all_rpcs (int signo, struct machine_thread_all_state *state, int live) | |
363 | { | |
364 | /* We can just loop over the sigstates. Any thread doing something | |
365 | interruptible must have one. We needn't bother locking because all | |
366 | other threads are stopped. */ | |
367 | ||
368 | struct hurd_sigstate *ss; | |
369 | size_t nthreads; | |
370 | mach_port_t *reply_ports; | |
371 | ||
372 | /* First loop over the sigstates to count them. | |
373 | We need to know how big a vector we will need for REPLY_PORTS. */ | |
374 | nthreads = 0; | |
375 | for (ss = _hurd_sigstates; ss != NULL; ss = ss->next) | |
376 | ++nthreads; | |
377 | ||
378 | reply_ports = alloca (nthreads * sizeof *reply_ports); | |
379 | ||
380 | nthreads = 0; | |
381 | for (ss = _hurd_sigstates; ss != NULL; ss = ss->next) | |
382 | if (ss->thread == _hurd_msgport_thread) | |
383 | reply_ports[nthreads++] = MACH_PORT_NULL; | |
384 | else | |
385 | { | |
386 | int state_changed; | |
387 | state->set = 0; /* Reset scratch area. */ | |
388 | ||
389 | /* Abort any operation in progress with interrupt_operation. | |
390 | Record the reply port the thread is waiting on. | |
391 | We will wait for all the replies below. */ | |
54da5be3 RM |
392 | reply_ports[nthreads++] = _hurdsig_abort_rpcs (ss, signo, 1, |
393 | state, &state_changed, | |
394 | NULL, 0, 0); | |
28f540f4 RM |
395 | if (state_changed && live) |
396 | /* Aborting the RPC needed to change this thread's state, | |
397 | and it might ever run again. So write back its state. */ | |
398 | __thread_set_state (ss->thread, MACHINE_THREAD_STATE_FLAVOR, | |
399 | (natural_t *) &state->basic, | |
400 | MACHINE_THREAD_STATE_COUNT); | |
401 | } | |
402 | ||
403 | /* Wait for replies from all the successfully interrupted RPCs. */ | |
404 | while (nthreads-- > 0) | |
405 | if (reply_ports[nthreads] != MACH_PORT_NULL) | |
406 | { | |
407 | error_t err; | |
408 | mach_msg_header_t head; | |
54da5be3 | 409 | err = __mach_msg (&head, MACH_RCV_MSG|MACH_RCV_TIMEOUT, 0, sizeof head, |
28f540f4 | 410 | reply_ports[nthreads], |
54da5be3 RM |
411 | _hurd_interrupted_rpc_timeout, MACH_PORT_NULL); |
412 | switch (err) | |
413 | { | |
414 | case MACH_RCV_TIMED_OUT: | |
415 | case MACH_RCV_TOO_LARGE: | |
416 | break; | |
417 | ||
418 | default: | |
419 | assert_perror (err); | |
420 | } | |
28f540f4 RM |
421 | } |
422 | } | |
423 | ||
424 | ||
425 | struct hurd_signal_preempt *_hurd_signal_preempt[NSIG]; | |
426 | struct mutex _hurd_signal_preempt_lock; | |
427 | ||
428 | /* Mask of stop signals. */ | |
429 | #define STOPSIGS (sigmask (SIGTTIN) | sigmask (SIGTTOU) | \ | |
430 | sigmask (SIGSTOP) | sigmask (SIGTSTP)) | |
431 | ||
432 | /* Deliver a signal. SS is not locked. */ | |
433 | void | |
434 | _hurd_internal_post_signal (struct hurd_sigstate *ss, | |
435 | int signo, long int sigcode, int sigerror, | |
436 | mach_port_t reply_port, | |
437 | mach_msg_type_name_t reply_port_type, | |
438 | int untraced) | |
439 | { | |
b96bdcd7 | 440 | error_t err; |
28f540f4 RM |
441 | struct machine_thread_all_state thread_state; |
442 | enum { stop, ignore, core, term, handle } act; | |
443 | sighandler_t handler; | |
444 | struct hurd_signal_preempt *pe; | |
445 | sighandler_t (*preempt) (thread_t, int, long int, int) = NULL; | |
446 | sigset_t pending; | |
447 | int ss_suspended; | |
448 | ||
449 | /* Reply to this sig_post message. */ | |
450 | inline void reply (void) | |
451 | { | |
452 | post_reply (&reply_port, reply_port_type, untraced, 0); | |
453 | } | |
454 | ||
455 | /* Mark the signal as pending. */ | |
456 | void mark_pending (void) | |
457 | { | |
458 | __sigaddset (&ss->pending, signo); | |
459 | /* Save the code to be given to the handler when SIGNO is | |
460 | unblocked. */ | |
461 | ss->pending_data[signo].code = sigcode; | |
462 | ss->pending_data[signo].error = sigerror; | |
463 | } | |
464 | ||
465 | /* Suspend the process with SIGNO. */ | |
466 | void suspend (void) | |
467 | { | |
468 | /* Stop all other threads and mark ourselves stopped. */ | |
469 | __USEPORT (PROC, | |
470 | ({ | |
471 | /* Hold the siglock while stopping other threads to be | |
472 | sure it is not held by another thread afterwards. */ | |
473 | __mutex_lock (&_hurd_siglock); | |
474 | __proc_dostop (port, _hurd_msgport_thread); | |
475 | __mutex_unlock (&_hurd_siglock); | |
476 | abort_all_rpcs (signo, &thread_state, 1); | |
477 | __proc_mark_stop (port, signo); | |
478 | })); | |
479 | _hurd_stopped = 1; | |
480 | } | |
481 | ||
482 | post_signal: | |
483 | ||
484 | thread_state.set = 0; /* We know nothing. */ | |
485 | ||
486 | /* Check for a preempted signal. Preempted signals | |
487 | can arrive during critical sections. */ | |
488 | __mutex_lock (&_hurd_signal_preempt_lock); | |
489 | for (pe = _hurd_signal_preempt[signo]; pe != NULL; pe = pe->next) | |
0677a80c | 490 | if (pe->handler && sigcode >= pe->first && sigcode <= pe->last) |
28f540f4 RM |
491 | { |
492 | preempt = pe->handler; | |
493 | break; | |
494 | } | |
495 | __mutex_unlock (&_hurd_signal_preempt_lock); | |
496 | ||
497 | handler = SIG_DFL; | |
498 | if (preempt) | |
499 | /* Let the preempting handler examine the thread. | |
500 | If it returns SIG_DFL, we run the normal handler; | |
501 | otherwise we use the handler it returns. */ | |
502 | handler = (*preempt) (ss->thread, signo, sigcode, sigerror); | |
503 | ||
504 | ss_suspended = 0; | |
505 | ||
506 | if (handler != SIG_DFL) | |
507 | /* Run the preemption-provided handler. */ | |
508 | act = handle; | |
509 | else | |
510 | { | |
511 | /* No preemption. Do normal handling. */ | |
512 | ||
513 | __spin_lock (&ss->lock); | |
514 | ||
515 | handler = ss->actions[signo].sa_handler; | |
516 | ||
517 | if (!untraced && (_hurd_exec_flags & EXEC_TRACED)) | |
518 | { | |
519 | /* We are being traced. Stop to tell the debugger of the signal. */ | |
520 | if (_hurd_stopped) | |
521 | /* Already stopped. Mark the signal as pending; | |
522 | when resumed, we will notice it and stop again. */ | |
523 | mark_pending (); | |
524 | else | |
525 | suspend (); | |
526 | __spin_unlock (&ss->lock); | |
527 | reply (); | |
528 | return; | |
529 | } | |
530 | ||
531 | if (handler == SIG_DFL) | |
532 | /* Figure out the default action for this signal. */ | |
533 | switch (signo) | |
534 | { | |
535 | case 0: | |
536 | /* A sig_post msg with SIGNO==0 is sent to | |
537 | tell us to check for pending signals. */ | |
538 | act = ignore; | |
539 | break; | |
540 | ||
541 | case SIGTTIN: | |
542 | case SIGTTOU: | |
543 | case SIGSTOP: | |
544 | case SIGTSTP: | |
545 | act = stop; | |
546 | break; | |
547 | ||
548 | case SIGCONT: | |
549 | case SIGIO: | |
550 | case SIGURG: | |
551 | case SIGCHLD: | |
552 | case SIGWINCH: | |
553 | act = ignore; | |
554 | break; | |
555 | ||
556 | case SIGQUIT: | |
557 | case SIGILL: | |
558 | case SIGTRAP: | |
559 | case SIGIOT: | |
560 | case SIGEMT: | |
561 | case SIGFPE: | |
562 | case SIGBUS: | |
563 | case SIGSEGV: | |
564 | case SIGSYS: | |
565 | act = core; | |
566 | break; | |
567 | ||
568 | case SIGINFO: | |
569 | if (_hurd_pgrp == _hurd_pid) | |
570 | { | |
571 | /* We are the process group leader. Since there is no | |
572 | user-specified handler for SIGINFO, we use a default one | |
573 | which prints something interesting. We use the normal | |
574 | handler mechanism instead of just doing it here to avoid | |
575 | the signal thread faulting or blocking in this | |
576 | potentially hairy operation. */ | |
577 | act = handle; | |
578 | handler = _hurd_siginfo_handler; | |
579 | } | |
580 | else | |
581 | act = ignore; | |
582 | break; | |
583 | ||
584 | default: | |
585 | act = term; | |
586 | break; | |
587 | } | |
588 | else if (handler == SIG_IGN) | |
589 | act = ignore; | |
590 | else | |
591 | act = handle; | |
592 | ||
593 | if (__sigmask (signo) & STOPSIGS) | |
594 | /* Stop signals clear a pending SIGCONT even if they | |
595 | are handled or ignored (but not if preempted). */ | |
596 | ss->pending &= ~sigmask (SIGCONT); | |
597 | else | |
598 | { | |
599 | if (signo == SIGCONT) | |
600 | /* Even if handled or ignored (but not preempted), SIGCONT clears | |
601 | stop signals and resumes the process. */ | |
602 | ss->pending &= ~STOPSIGS; | |
603 | ||
604 | if (_hurd_stopped && act != stop && (untraced || signo == SIGCONT)) | |
605 | { | |
606 | /* Resume the process from being stopped. */ | |
607 | thread_t *threads; | |
608 | mach_msg_type_number_t nthreads, i; | |
609 | error_t err; | |
610 | /* Tell the proc server we are continuing. */ | |
611 | __USEPORT (PROC, __proc_mark_cont (port)); | |
612 | /* Fetch ports to all our threads and resume them. */ | |
613 | err = __task_threads (__mach_task_self (), &threads, &nthreads); | |
614 | assert_perror (err); | |
615 | for (i = 0; i < nthreads; ++i) | |
616 | { | |
617 | if (threads[i] != _hurd_msgport_thread && | |
618 | (act != handle || threads[i] != ss->thread)) | |
b96bdcd7 RM |
619 | { |
620 | err = __thread_resume (threads[i]); | |
621 | assert_perror (err); | |
622 | } | |
623 | err = __mach_port_deallocate (__mach_task_self (), | |
624 | threads[i]); | |
625 | assert_perror (err); | |
28f540f4 RM |
626 | } |
627 | __vm_deallocate (__mach_task_self (), | |
628 | (vm_address_t) threads, | |
629 | nthreads * sizeof *threads); | |
630 | _hurd_stopped = 0; | |
631 | /* The thread that will run the handler is already suspended. */ | |
632 | ss_suspended = 1; | |
633 | } | |
634 | } | |
635 | } | |
636 | ||
637 | if (_hurd_orphaned && act == stop && | |
638 | (__sigmask (signo) & (__sigmask (SIGTTIN) | __sigmask (SIGTTOU) | | |
639 | __sigmask (SIGTSTP)))) | |
640 | { | |
641 | /* If we would ordinarily stop for a job control signal, but we are | |
642 | orphaned so noone would ever notice and continue us again, we just | |
643 | quietly die, alone and in the dark. */ | |
644 | sigcode = signo; | |
645 | signo = SIGKILL; | |
646 | act = term; | |
647 | } | |
648 | ||
649 | /* Handle receipt of a blocked signal, or any signal while stopped. | |
650 | It matters that we test ACT first here, because we must never pass | |
651 | SIGNO==0 to __sigismember. */ | |
652 | if ((act != ignore && __sigismember (&ss->blocked, signo)) || | |
653 | (signo != SIGKILL && _hurd_stopped)) | |
654 | { | |
655 | mark_pending (); | |
656 | act = ignore; | |
657 | } | |
658 | ||
659 | /* Perform the chosen action for the signal. */ | |
660 | switch (act) | |
661 | { | |
662 | case stop: | |
663 | if (_hurd_stopped) | |
b96bdcd7 RM |
664 | { |
665 | /* We are already stopped, but receiving an untraced stop | |
666 | signal. Instead of resuming and suspending again, just | |
667 | notify the proc server of the new stop signal. */ | |
668 | error_t err = __USEPORT (PROC, __proc_mark_stop (port, signo)); | |
669 | assert_perror (err); | |
670 | } | |
28f540f4 RM |
671 | else |
672 | /* Suspend the process. */ | |
673 | suspend (); | |
674 | break; | |
675 | ||
676 | case ignore: | |
677 | /* Nobody cares about this signal. */ | |
678 | break; | |
679 | ||
421f82e5 RM |
680 | sigbomb: |
681 | /* We got a fault setting up the stack frame for the handler. | |
682 | Nothing to do but die; BSD gets SIGILL in this case. */ | |
683 | sigcode = signo; /* XXX ? */ | |
684 | signo = SIGILL; | |
685 | act = core; | |
686 | /* FALLTHROUGH */ | |
687 | ||
28f540f4 RM |
688 | case term: /* Time to die. */ |
689 | case core: /* And leave a rotting corpse. */ | |
28f540f4 | 690 | /* Have the proc server stop all other threads in our task. */ |
b96bdcd7 RM |
691 | err = __USEPORT (PROC, __proc_dostop (port, _hurd_msgport_thread)); |
692 | assert_perror (err); | |
28f540f4 RM |
693 | /* No more user instructions will be executed. |
694 | The signal can now be considered delivered. */ | |
695 | reply (); | |
696 | /* Abort all server operations now in progress. */ | |
697 | abort_all_rpcs (signo, &thread_state, 0); | |
698 | ||
699 | { | |
700 | int status = W_EXITCODE (0, signo); | |
701 | /* Do a core dump if desired. Only set the wait status bit saying we | |
702 | in fact dumped core if the operation was actually successful. */ | |
703 | if (act == core && write_corefile (signo, sigcode, sigerror)) | |
704 | status |= WCOREFLAG; | |
705 | /* Tell proc how we died and then stick the saber in the gut. */ | |
706 | _hurd_exit (status); | |
707 | /* NOTREACHED */ | |
708 | } | |
709 | ||
710 | case handle: | |
711 | /* Call a handler for this signal. */ | |
712 | { | |
421f82e5 | 713 | struct sigcontext *scp, ocontext; |
28f540f4 RM |
714 | int wait_for_reply, state_changed; |
715 | ||
716 | /* Stop the thread and abort its pending RPC operations. */ | |
717 | if (! ss_suspended) | |
b96bdcd7 RM |
718 | { |
719 | err = __thread_suspend (ss->thread); | |
720 | assert_perror (err); | |
721 | } | |
28f540f4 RM |
722 | |
723 | /* Abort the thread's kernel context, so any pending message send | |
724 | or receive completes immediately or aborts. If an interruptible | |
725 | RPC is in progress, abort_rpcs will do this. But we must always | |
726 | do it before fetching the thread's state, because | |
727 | thread_get_state is never kosher before thread_abort. */ | |
728 | abort_thread (ss, &thread_state, NULL, 0, 0); | |
729 | ||
421f82e5 RM |
730 | if (ss->context) |
731 | { | |
732 | /* We have a previous sigcontext that sigreturn was about | |
733 | to restore when another signal arrived. */ | |
734 | ||
735 | mach_port_t *loc; | |
28f540f4 | 736 | |
421f82e5 RM |
737 | if (_hurdsig_catch_fault (SIGSEGV)) |
738 | { | |
739 | assert (_hurdsig_fault_sigcode >= (long int) ss->context && | |
740 | _hurdsig_fault_sigcode < (long int) (ss->context + 1)); | |
741 | /* We faulted reading the thread's stack. Forget that | |
742 | context and pretend it wasn't there. It almost | |
743 | certainly crash if this handler returns, but that's it's | |
744 | problem. */ | |
745 | ss->context = NULL; | |
746 | } | |
747 | else | |
748 | { | |
749 | /* Copy the context from the thread's stack before | |
750 | we start diddling the stack to set up the handler. */ | |
751 | ocontext = *ss->context; | |
752 | ss->context = &ocontext; | |
753 | } | |
754 | _hurdsig_end_catch_fault (); | |
755 | ||
756 | if (! machine_get_basic_state (ss->thread, &thread_state)) | |
757 | goto sigbomb; | |
54da5be3 | 758 | loc = interrupted_reply_port_location (&thread_state, 1); |
421f82e5 RM |
759 | if (loc && *loc != MACH_PORT_NULL) |
760 | /* This is the reply port for the context which called | |
761 | sigreturn. Since we are abandoning that context entirely | |
762 | and restoring SS->context instead, destroy this port. */ | |
763 | __mach_port_destroy (__mach_task_self (), *loc); | |
764 | ||
765 | /* The thread was in sigreturn, not in any interruptible RPC. */ | |
766 | wait_for_reply = 0; | |
767 | ||
768 | assert (! ss->critical_section); | |
769 | } | |
770 | else | |
28f540f4 | 771 | { |
54da5be3 RM |
772 | wait_for_reply |
773 | = (_hurdsig_abort_rpcs (ss, signo, 1, | |
774 | &thread_state, &state_changed, | |
775 | &reply_port, reply_port_type, untraced) | |
776 | != MACH_PORT_NULL); | |
421f82e5 RM |
777 | |
778 | if (ss->critical_section) | |
779 | { | |
780 | /* The thread is in a critical section. Mark the signal as | |
781 | pending. When it finishes the critical section, it will | |
782 | check for pending signals. */ | |
783 | mark_pending (); | |
784 | assert (! state_changed); | |
785 | __thread_resume (ss->thread); | |
786 | break; | |
787 | } | |
28f540f4 RM |
788 | } |
789 | ||
790 | /* Call the machine-dependent function to set the thread up | |
791 | to run the signal handler, and preserve its old context. */ | |
792 | scp = _hurd_setup_sighandler (ss, handler, | |
793 | signo, sigcode, | |
794 | wait_for_reply, &thread_state); | |
795 | if (scp == NULL) | |
421f82e5 | 796 | goto sigbomb; |
28f540f4 RM |
797 | |
798 | /* Set the machine-independent parts of the signal context. */ | |
799 | ||
28f540f4 RM |
800 | { |
801 | /* Fetch the thread variable for the MiG reply port, | |
802 | and set it to MACH_PORT_NULL. */ | |
54da5be3 RM |
803 | mach_port_t *loc = interrupted_reply_port_location (&thread_state, |
804 | 1); | |
28f540f4 RM |
805 | if (loc) |
806 | { | |
807 | scp->sc_reply_port = *loc; | |
808 | *loc = MACH_PORT_NULL; | |
809 | } | |
810 | else | |
811 | scp->sc_reply_port = MACH_PORT_NULL; | |
421f82e5 RM |
812 | |
813 | /* Save the intr_port in use by the interrupted code, | |
814 | and clear the cell before running the trampoline. */ | |
815 | scp->sc_intr_port = ss->intr_port; | |
816 | ss->intr_port = MACH_PORT_NULL; | |
817 | ||
818 | if (ss->context) | |
819 | { | |
820 | /* After the handler runs we will restore to the state in | |
821 | SS->context, not the state of the thread now. So restore | |
822 | that context's reply port and intr port. */ | |
823 | ||
824 | scp->sc_reply_port = ss->context->sc_reply_port; | |
825 | scp->sc_intr_port = ss->context->sc_intr_port; | |
826 | ||
827 | ss->context = NULL; | |
828 | } | |
28f540f4 RM |
829 | } |
830 | ||
421f82e5 RM |
831 | /* Backdoor extra argument to signal handler. */ |
832 | scp->sc_error = sigerror; | |
833 | ||
28f540f4 RM |
834 | /* Block SIGNO and requested signals while running the handler. */ |
835 | scp->sc_mask = ss->blocked; | |
836 | ss->blocked |= __sigmask (signo) | ss->actions[signo].sa_mask; | |
837 | ||
28f540f4 RM |
838 | /* Start the thread running the handler (or possibly waiting for an |
839 | RPC reply before running the handler). */ | |
b96bdcd7 RM |
840 | err = __thread_set_state (ss->thread, MACHINE_THREAD_STATE_FLAVOR, |
841 | (natural_t *) &thread_state.basic, | |
842 | MACHINE_THREAD_STATE_COUNT); | |
843 | assert_perror (err); | |
844 | err = __thread_resume (ss->thread); | |
845 | assert_perror (err); | |
28f540f4 RM |
846 | thread_state.set = 0; /* Everything we know is now wrong. */ |
847 | break; | |
848 | } | |
849 | } | |
850 | ||
851 | /* The signal has either been ignored or is now being handled. We can | |
852 | consider it delivered and reply to the killer. The exception is | |
853 | signal 0, which can be sent by a user thread to make us check for | |
854 | pending signals. In that case we want to deliver the pending signals | |
855 | before replying. */ | |
856 | if (signo != 0) | |
857 | reply (); | |
858 | ||
859 | /* We get here unless the signal was fatal. We still hold SS->lock. | |
860 | Check for pending signals, and loop to post them. */ | |
7cc645ed RM |
861 | { |
862 | /* Return nonzero if SS has any signals pending we should worry about. | |
863 | We don't worry about any pending signals if we are stopped, nor if | |
864 | SS is in a critical section. We are guaranteed to get a sig_post | |
865 | message before any of them become deliverable: either the SIGCONT | |
866 | signal, or a sig_post with SIGNO==0 as an explicit poll when the | |
867 | thread finishes its critical section. */ | |
868 | inline int signals_pending (void) | |
869 | { | |
870 | if (_hurd_stopped || ss->critical_section) | |
871 | return 0; | |
872 | return pending = ss->pending & ~ss->blocked; | |
873 | } | |
874 | ||
875 | if (signals_pending ()) | |
876 | { | |
877 | pending: | |
878 | for (signo = 1; signo < NSIG; ++signo) | |
879 | if (__sigismember (&pending, signo)) | |
880 | { | |
881 | __sigdelset (&ss->pending, signo); | |
882 | sigcode = ss->pending_data[signo].code; | |
883 | sigerror = ss->pending_data[signo].error; | |
884 | __spin_unlock (&ss->lock); | |
885 | goto post_signal; | |
886 | } | |
887 | } | |
888 | ||
889 | /* No pending signals left undelivered for this thread. | |
890 | If we were sent signal 0, we need to check for pending | |
891 | signals for all threads. */ | |
892 | if (signo == 0) | |
893 | { | |
894 | __spin_unlock (&ss->lock); | |
895 | __mutex_lock (&_hurd_siglock); | |
896 | for (ss = _hurd_sigstates; ss != NULL; ss = ss->next) | |
28f540f4 | 897 | { |
7cc645ed RM |
898 | __spin_lock (&ss->lock); |
899 | if (signals_pending ()) | |
900 | goto pending; | |
28f540f4 | 901 | __spin_unlock (&ss->lock); |
28f540f4 | 902 | } |
7cc645ed RM |
903 | __mutex_unlock (&_hurd_siglock); |
904 | } | |
905 | else | |
906 | { | |
907 | /* No more signals pending; SS->lock is still locked. | |
908 | Wake up any sigsuspend call that is blocking SS->thread. */ | |
909 | if (ss->suspended != MACH_PORT_NULL) | |
910 | { | |
911 | /* There is a sigsuspend waiting. Tell it to wake up. */ | |
912 | error_t err; | |
913 | mach_msg_header_t msg; | |
914 | err = __mach_port_insert_right (__mach_task_self (), | |
915 | ss->suspended, ss->suspended, | |
916 | MACH_MSG_TYPE_MAKE_SEND); | |
917 | assert_perror (err); | |
918 | msg.msgh_bits = MACH_MSGH_BITS (MACH_MSG_TYPE_MOVE_SEND, 0); | |
919 | msg.msgh_remote_port = ss->suspended; | |
920 | msg.msgh_local_port = MACH_PORT_NULL; | |
921 | /* These values do not matter. */ | |
922 | msg.msgh_id = 8675309; /* Jenny, Jenny. */ | |
923 | msg.msgh_seqno = 17; /* Random. */ | |
924 | ss->suspended = MACH_PORT_NULL; | |
925 | err = __mach_msg (&msg, MACH_SEND_MSG, sizeof msg, 0, | |
926 | MACH_PORT_NULL, MACH_MSG_TIMEOUT_NONE, | |
927 | MACH_PORT_NULL); | |
928 | assert_perror (err); | |
929 | } | |
930 | __spin_unlock (&ss->lock); | |
931 | } | |
932 | } | |
28f540f4 RM |
933 | |
934 | /* All pending signals delivered to all threads. | |
935 | Now we can send the reply message even for signal 0. */ | |
936 | reply (); | |
937 | } | |
938 | \f | |
939 | /* Decide whether REFPORT enables the sender to send us a SIGNO signal. | |
940 | Returns zero if so, otherwise the error code to return to the sender. */ | |
941 | ||
942 | static error_t | |
943 | signal_allowed (int signo, mach_port_t refport) | |
944 | { | |
945 | if (signo < 0 || signo >= NSIG) | |
946 | return EINVAL; | |
947 | ||
948 | if (refport == __mach_task_self ()) | |
949 | /* Can send any signal. */ | |
950 | goto win; | |
951 | ||
952 | /* Avoid needing to check for this below. */ | |
953 | if (refport == MACH_PORT_NULL) | |
954 | return EPERM; | |
955 | ||
956 | switch (signo) | |
957 | { | |
958 | case SIGINT: | |
959 | case SIGQUIT: | |
960 | case SIGTSTP: | |
961 | case SIGHUP: | |
962 | case SIGINFO: | |
963 | case SIGTTIN: | |
964 | case SIGTTOU: | |
965 | /* Job control signals can be sent by the controlling terminal. */ | |
966 | if (__USEPORT (CTTYID, port == refport)) | |
967 | goto win; | |
968 | break; | |
969 | ||
970 | case SIGCONT: | |
971 | { | |
972 | /* A continue signal can be sent by anyone in the session. */ | |
973 | mach_port_t sessport; | |
974 | if (! __USEPORT (PROC, __proc_getsidport (port, &sessport))) | |
975 | { | |
976 | __mach_port_deallocate (__mach_task_self (), sessport); | |
977 | if (refport == sessport) | |
978 | goto win; | |
979 | } | |
980 | } | |
981 | break; | |
982 | ||
983 | case SIGIO: | |
984 | case SIGURG: | |
985 | { | |
986 | /* Any io object a file descriptor refers to might send us | |
987 | one of these signals using its async ID port for REFPORT. | |
988 | ||
989 | This is pretty wide open; it is not unlikely that some random | |
990 | process can at least open for reading something we have open, | |
991 | get its async ID port, and send us a spurious SIGIO or SIGURG | |
992 | signal. But BSD is actually wider open than that!--you can set | |
993 | the owner of an io object to any process or process group | |
994 | whatsoever and send them gratuitous signals. | |
995 | ||
996 | Someday we could implement some reasonable scheme for | |
997 | authorizing SIGIO and SIGURG signals properly. */ | |
998 | ||
999 | int d; | |
1000 | __mutex_lock (&_hurd_dtable_lock); | |
1001 | for (d = 0; (unsigned int) d < (unsigned int) _hurd_dtablesize; ++d) | |
1002 | { | |
1003 | struct hurd_userlink ulink; | |
1004 | io_t port; | |
1005 | mach_port_t asyncid; | |
1006 | if (_hurd_dtable[d] == NULL) | |
1007 | continue; | |
1008 | port = _hurd_port_get (&_hurd_dtable[d]->port, &ulink); | |
1009 | if (! __io_get_icky_async_id (port, &asyncid)) | |
1010 | { | |
1011 | if (refport == asyncid) | |
1012 | /* Break out of the loop on the next iteration. */ | |
1013 | d = -1; | |
1014 | __mach_port_deallocate (__mach_task_self (), asyncid); | |
1015 | } | |
1016 | _hurd_port_free (&_hurd_dtable[d]->port, &ulink, port); | |
1017 | } | |
1018 | /* If we found a lucky winner, we've set D to -1 in the loop. */ | |
1019 | if (d < 0) | |
1020 | goto win; | |
1021 | } | |
1022 | } | |
1023 | ||
1024 | /* If this signal is legit, we have done `goto win' by now. | |
1025 | When we return the error, mig deallocates REFPORT. */ | |
1026 | return EPERM; | |
1027 | ||
1028 | win: | |
1029 | /* Deallocate the REFPORT send right; we are done with it. */ | |
1030 | __mach_port_deallocate (__mach_task_self (), refport); | |
1031 | ||
1032 | return 0; | |
1033 | } | |
1034 | ||
1035 | /* Implement the sig_post RPC from <hurd/msg.defs>; | |
1036 | sent when someone wants us to get a signal. */ | |
1037 | kern_return_t | |
1038 | _S_msg_sig_post (mach_port_t me, | |
1039 | mach_port_t reply_port, mach_msg_type_name_t reply_port_type, | |
1040 | int signo, | |
1041 | mach_port_t refport) | |
1042 | { | |
1043 | error_t err; | |
1044 | ||
1045 | if (err = signal_allowed (signo, refport)) | |
1046 | return err; | |
1047 | ||
1048 | /* Post the signal to the designated signal-receiving thread. This will | |
1049 | reply when the signal can be considered delivered. */ | |
1050 | _hurd_internal_post_signal (_hurd_thread_sigstate (_hurd_sigthread), | |
1051 | signo, 0, 0, reply_port, reply_port_type, | |
1052 | 0); /* Stop if traced. */ | |
1053 | ||
1054 | return MIG_NO_REPLY; /* Already replied. */ | |
1055 | } | |
1056 | ||
1057 | /* Implement the sig_post_untraced RPC from <hurd/msg.defs>; | |
1058 | sent when the debugger wants us to really get a signal | |
1059 | even if we are traced. */ | |
1060 | kern_return_t | |
1061 | _S_msg_sig_post_untraced (mach_port_t me, | |
1062 | mach_port_t reply_port, | |
1063 | mach_msg_type_name_t reply_port_type, | |
1064 | int signo, | |
1065 | mach_port_t refport) | |
1066 | { | |
1067 | error_t err; | |
1068 | ||
1069 | if (err = signal_allowed (signo, refport)) | |
1070 | return err; | |
1071 | ||
1072 | /* Post the signal to the designated signal-receiving thread. This will | |
1073 | reply when the signal can be considered delivered. */ | |
1074 | _hurd_internal_post_signal (_hurd_thread_sigstate (_hurd_sigthread), | |
1075 | signo, 0, 0, reply_port, reply_port_type, | |
1076 | 1); /* Untraced flag. */ | |
1077 | ||
1078 | return MIG_NO_REPLY; /* Already replied. */ | |
1079 | } | |
1080 | \f | |
1081 | extern void __mig_init (void *); | |
1082 | ||
1083 | #include <mach/task_special_ports.h> | |
1084 | ||
1085 | /* Initialize the message port and _hurd_sigthread and start the signal | |
1086 | thread. */ | |
1087 | ||
1088 | void | |
1089 | _hurdsig_init (void) | |
1090 | { | |
1091 | error_t err; | |
1092 | vm_size_t stacksize; | |
1093 | ||
1094 | __mutex_init (&_hurd_siglock); | |
1095 | ||
1096 | if (err = __mach_port_allocate (__mach_task_self (), | |
1097 | MACH_PORT_RIGHT_RECEIVE, | |
1098 | &_hurd_msgport)) | |
1099 | __libc_fatal ("hurd: Can't create message port receive right\n"); | |
1100 | ||
1101 | /* Make a send right to the signal port. */ | |
1102 | if (err = __mach_port_insert_right (__mach_task_self (), | |
1103 | _hurd_msgport, | |
1104 | _hurd_msgport, | |
1105 | MACH_MSG_TYPE_MAKE_SEND)) | |
1106 | __libc_fatal ("hurd: Can't create send right to message port\n"); | |
1107 | ||
1108 | /* Set the default thread to receive task-global signals | |
1109 | to this one, the main (first) user thread. */ | |
1110 | _hurd_sigthread = __mach_thread_self (); | |
1111 | ||
1112 | /* Start the signal thread listening on the message port. */ | |
1113 | ||
1114 | if (err = __thread_create (__mach_task_self (), &_hurd_msgport_thread)) | |
1115 | __libc_fatal ("hurd: Can't create signal thread\n"); | |
1116 | ||
1117 | stacksize = __vm_page_size * 4; /* Small stack for signal thread. */ | |
1118 | if (err = __mach_setup_thread (__mach_task_self (), _hurd_msgport_thread, | |
1119 | _hurd_msgport_receive, | |
1120 | (vm_address_t *) &__hurd_sigthread_stack_base, | |
1121 | &stacksize)) | |
1122 | __libc_fatal ("hurd: Can't setup signal thread\n"); | |
1123 | ||
1124 | __hurd_sigthread_stack_end = __hurd_sigthread_stack_base + stacksize; | |
1125 | __hurd_sigthread_variables = | |
1126 | malloc (__hurd_threadvar_max * sizeof (unsigned long int)); | |
1127 | if (__hurd_sigthread_variables == NULL) | |
1128 | __libc_fatal ("hurd: Can't allocate thread variables for signal thread\n"); | |
1129 | ||
1130 | /* Reinitialize the MiG support routines so they will use a per-thread | |
1131 | variable for the cached reply port. */ | |
1132 | __mig_init ((void *) __hurd_sigthread_stack_base); | |
1133 | ||
1134 | if (err = __thread_resume (_hurd_msgport_thread)) | |
1135 | __libc_fatal ("hurd: Can't resume signal thread\n"); | |
1136 | ||
1137 | #if 0 /* Don't confuse poor gdb. */ | |
1138 | /* Receive exceptions on the signal port. */ | |
1139 | __task_set_special_port (__mach_task_self (), | |
1140 | TASK_EXCEPTION_PORT, _hurd_msgport); | |
1141 | #endif | |
1142 | } | |
1143 | \f /* XXXX */ | |
1144 | /* Reauthenticate with the proc server. */ | |
1145 | ||
1146 | static void | |
1147 | reauth_proc (mach_port_t new) | |
1148 | { | |
1149 | mach_port_t ref, ignore; | |
1150 | ||
1151 | ref = __mach_reply_port (); | |
1152 | if (! HURD_PORT_USE (&_hurd_ports[INIT_PORT_PROC], | |
1153 | __proc_reauthenticate (port, ref, | |
1154 | MACH_MSG_TYPE_MAKE_SEND) || | |
1155 | __auth_user_authenticate (new, port, ref, | |
1156 | MACH_MSG_TYPE_MAKE_SEND, | |
1157 | &ignore)) | |
1158 | && ignore != MACH_PORT_NULL) | |
1159 | __mach_port_deallocate (__mach_task_self (), ignore); | |
1160 | __mach_port_destroy (__mach_task_self (), ref); | |
1161 | ||
1162 | (void) &reauth_proc; /* Silence compiler warning. */ | |
1163 | } | |
1164 | text_set_element (_hurd_reauth_hook, reauth_proc); | |
1165 | \f | |
1166 | /* Like `getenv', but safe for the signal thread to run. | |
1167 | If the environment is trashed, this will just return NULL. */ | |
1168 | ||
1169 | const char * | |
1170 | _hurdsig_getenv (const char *variable) | |
1171 | { | |
1172 | if (_hurdsig_catch_fault (SIGSEGV)) | |
1173 | /* We bombed in getenv. */ | |
1174 | return NULL; | |
1175 | else | |
1176 | { | |
1177 | const char *value = getenv (variable); | |
1178 | /* Fault now if VALUE is a bogus string. */ | |
1179 | (void) strlen (value); | |
1180 | _hurdsig_end_catch_fault (); | |
1181 | return value; | |
1182 | } | |
1183 | } |