2 * interrupt-handling magic
6 * This software is part of the SBCL system. See the README file for
9 * This software is derived from the CMU CL system, which was
10 * written at Carnegie Mellon University and released into the
11 * public domain. The software is in the public domain and is
12 * provided with absolutely no warranty. See the COPYING and CREDITS
13 * files for more information.
17 /* As far as I can tell, what's going on here is:
19 * In the case of most signals, when Lisp asks us to handle the
20 * signal, the outermost handler (the one actually passed to UNIX) is
21 * either interrupt_handle_now(..) or maybe_now_maybe_later(..).
22 * In that case, the Lisp-level handler is stored in interrupt_handlers[..]
23 * and interrupt_low_level_handlers[..] is cleared.
25 * However, some signals need special handling, e.g.
27 * o the SIGSEGV (for e.g. Linux) or SIGBUS (for e.g. FreeBSD) used by the
28 * garbage collector to detect violations of write protection,
29 * because some cases of such signals (e.g. GC-related violations of
30 * write protection) are handled at C level and never passed on to
31 * Lisp. For such signals, we still store any Lisp-level handler
32 * in interrupt_handlers[..], but for the outermost handle we use
33 * the value from interrupt_low_level_handlers[..], instead of the
34 * ordinary interrupt_handle_now(..) or interrupt_handle_later(..).
36 * o the SIGTRAP (Linux/Alpha) which Lisp code uses to handle breakpoints,
37 * pseudo-atomic sections, and some classes of error (e.g. "function
38 * not defined"). This never goes anywhere near the Lisp handlers at all.
39 * See runtime/alpha-arch.c and code/signal.lisp
41 * - WHN 20000728, dan 20010128 */
49 #include <sys/types.h>
50 #ifndef LISP_FEATURE_WIN32
58 #include "interrupt.h"
66 #include "pseudo-atomic.h"
67 #include "genesis/fdefn.h"
68 #include "genesis/simple-fun.h"
69 #include "genesis/cons.h"
71 static void run_deferred_handler(struct interrupt_data *data, void *v_context);
72 #ifndef LISP_FEATURE_WIN32
73 static void store_signal_data_for_later (struct interrupt_data *data,
74 void *handler, int signal,
76 os_context_t *context);
79 fill_current_sigmask(sigset_t *sigset)
81 /* Get the current sigmask, by blocking the empty set. */
84 thread_sigmask(SIG_BLOCK, &empty, sigset);
88 sigaddset_deferrable(sigset_t *s)
92 sigaddset(s, SIGTERM);
93 sigaddset(s, SIGQUIT);
94 sigaddset(s, SIGPIPE);
95 sigaddset(s, SIGALRM);
97 sigaddset(s, SIGTSTP);
98 sigaddset(s, SIGCHLD);
100 #ifndef LISP_FEATURE_HPUX
101 sigaddset(s, SIGXCPU);
102 sigaddset(s, SIGXFSZ);
104 sigaddset(s, SIGVTALRM);
105 sigaddset(s, SIGPROF);
106 sigaddset(s, SIGWINCH);
108 #ifdef LISP_FEATURE_SB_THREAD
109 sigaddset(s, SIG_INTERRUPT_THREAD);
114 sigaddset_blockable(sigset_t *sigset)
116 sigaddset_deferrable(sigset);
117 #ifdef LISP_FEATURE_SB_THREAD
118 sigaddset(sigset,SIG_STOP_FOR_GC);
122 /* initialized in interrupt_init */
123 sigset_t deferrable_sigset;
124 sigset_t blockable_sigset;
128 check_deferrables_unblocked_in_sigset_or_lose(sigset_t *sigset)
130 #if !defined(LISP_FEATURE_WIN32)
132 for(i = 1; i < NSIG; i++) {
133 if (sigismember(&deferrable_sigset, i) && sigismember(sigset, i))
134 lose("deferrable signal %d blocked\n",i);
140 check_deferrables_blocked_in_sigset_or_lose(sigset_t *sigset)
142 #if !defined(LISP_FEATURE_WIN32)
144 for(i = 1; i < NSIG; i++) {
145 if (sigismember(&deferrable_sigset, i) && !sigismember(sigset, i))
146 lose("deferrable signal %d not blocked\n",i);
152 check_deferrables_blocked_or_lose(void)
154 #if !defined(LISP_FEATURE_WIN32)
156 fill_current_sigmask(¤t);
157 check_deferrables_blocked_in_sigset_or_lose(¤t);
162 check_blockables_blocked_or_lose(void)
164 #if !defined(LISP_FEATURE_WIN32)
165 /* Get the current sigmask, by blocking the empty set. */
166 sigset_t empty,current;
169 thread_sigmask(SIG_BLOCK, &empty, ¤t);
170 for(i = 1; i < NSIG; i++) {
171 if (sigismember(&blockable_sigset, i) && !sigismember(¤t, i))
172 lose("blockable signal %d not blocked\n",i);
178 unblock_gc_signals(void)
180 #ifdef LISP_FEATURE_SB_THREAD
183 #if defined(SIG_RESUME_FROM_GC)
184 sigaddset(&new,SIG_RESUME_FROM_GC);
186 sigaddset(&new,SIG_STOP_FOR_GC);
187 thread_sigmask(SIG_UNBLOCK,&new,0);
192 check_interrupts_enabled_or_lose(os_context_t *context)
194 struct thread *thread=arch_os_get_current_thread();
195 if (SymbolValue(INTERRUPTS_ENABLED,thread) == NIL)
196 lose("interrupts not enabled\n");
197 if (arch_pseudo_atomic_atomic(context))
198 lose ("in pseudo atomic section\n");
201 /* Are we leaving WITH-GCING and already running with interrupts
202 * enabled, without the protection of *GC-INHIBIT* T and there is gc
203 * (or stop for gc) pending, but we haven't trapped yet? */
205 in_leaving_without_gcing_race_p(struct thread *thread)
207 return ((SymbolValue(IN_WITHOUT_GCING,thread) != NIL) &&
208 (SymbolValue(INTERRUPTS_ENABLED,thread) != NIL) &&
209 (SymbolValue(GC_INHIBIT,thread) == NIL) &&
210 ((SymbolValue(GC_PENDING,thread) != NIL)
211 #if defined(LISP_FEATURE_SB_THREAD)
212 || (SymbolValue(STOP_FOR_GC_PENDING,thread) != NIL)
217 /* Check our baroque invariants. */
219 check_interrupt_context_or_lose(os_context_t *context)
221 struct thread *thread = arch_os_get_current_thread();
222 struct interrupt_data *data = thread->interrupt_data;
223 int interrupt_deferred_p = (data->pending_handler != 0);
224 int interrupt_pending = (SymbolValue(INTERRUPT_PENDING,thread) != NIL);
225 /* On PPC pseudo_atomic_interrupted is cleared when coming out of
226 * handle_allocation_trap. */
227 #if defined(LISP_FEATURE_GENCGC) && !defined(LISP_FEATURE_PPC)
229 int interrupts_enabled = (SymbolValue(INTERRUPTS_ENABLED,thread) != NIL);
231 int gc_inhibit = (SymbolValue(GC_INHIBIT,thread) != NIL);
232 int gc_pending = (SymbolValue(GC_PENDING,thread) == T);
233 int pseudo_atomic_interrupted = get_pseudo_atomic_interrupted(thread);
234 int in_race_p = in_leaving_without_gcing_race_p(thread);
235 /* In the time window between leaving the *INTERRUPTS-ENABLED* NIL
236 * section and trapping, a SIG_STOP_FOR_GC would see the next
237 * check fail, for this reason sig_stop_for_gc handler does not
238 * call this function. Plus, there may be interrupt lossage when a
239 * pseudo atomic is interrupted by a deferrable signal and gc is
242 if (interrupt_deferred_p)
243 if (!(!interrupts_enabled || pseudo_atomic_interrupted || in_race_p))
244 lose("Stray deferred interrupt.");
248 if (!(pseudo_atomic_interrupted || gc_inhibit || in_race_p))
249 lose("GC_PENDING, but why?.");
250 #if defined(LISP_FEATURE_SB_THREAD)
252 int stop_for_gc_pending =
253 (SymbolValue(STOP_FOR_GC_PENDING,thread) != NIL);
254 if (stop_for_gc_pending)
255 if (!(pseudo_atomic_interrupted || gc_inhibit || in_race_p))
256 lose("STOP_FOR_GC_PENDING, but why?.");
261 if (interrupt_pending && !interrupt_deferred_p)
262 lose("INTERRUPT_PENDING but not pending handler.");
263 if (interrupt_deferred_p)
264 check_deferrables_blocked_in_sigset_or_lose
265 (os_context_sigmask_addr(context));
267 check_deferrables_unblocked_in_sigset_or_lose
268 (os_context_sigmask_addr(context));
271 /* When we catch an internal error, should we pass it back to Lisp to
272 * be handled in a high-level way? (Early in cold init, the answer is
273 * 'no', because Lisp is still too brain-dead to handle anything.
274 * After sufficient initialization has been completed, the answer
276 boolean internal_errors_enabled = 0;
278 #ifndef LISP_FEATURE_WIN32
279 static void (*interrupt_low_level_handlers[NSIG]) (int, siginfo_t*, void*);
281 union interrupt_handler interrupt_handlers[NSIG];
284 block_blockable_signals(void)
286 #ifndef LISP_FEATURE_WIN32
287 thread_sigmask(SIG_BLOCK, &blockable_sigset, 0);
292 block_deferrable_signals(void)
294 #ifndef LISP_FEATURE_WIN32
295 thread_sigmask(SIG_BLOCK, &deferrable_sigset, 0);
300 unblock_deferrable_signals(void)
302 #ifndef LISP_FEATURE_WIN32
303 thread_sigmask(SIG_UNBLOCK, &deferrable_sigset, 0);
309 * utility routines used by various signal handlers
313 build_fake_control_stack_frames(struct thread *th,os_context_t *context)
315 #ifndef LISP_FEATURE_C_STACK_IS_CONTROL_STACK
319 /* Build a fake stack frame or frames */
321 current_control_frame_pointer =
322 (lispobj *)(unsigned long)
323 (*os_context_register_addr(context, reg_CSP));
324 if ((lispobj *)(unsigned long)
325 (*os_context_register_addr(context, reg_CFP))
326 == current_control_frame_pointer) {
327 /* There is a small window during call where the callee's
328 * frame isn't built yet. */
329 if (lowtag_of(*os_context_register_addr(context, reg_CODE))
330 == FUN_POINTER_LOWTAG) {
331 /* We have called, but not built the new frame, so
332 * build it for them. */
333 current_control_frame_pointer[0] =
334 *os_context_register_addr(context, reg_OCFP);
335 current_control_frame_pointer[1] =
336 *os_context_register_addr(context, reg_LRA);
337 current_control_frame_pointer += 8;
338 /* Build our frame on top of it. */
339 oldcont = (lispobj)(*os_context_register_addr(context, reg_CFP));
342 /* We haven't yet called, build our frame as if the
343 * partial frame wasn't there. */
344 oldcont = (lispobj)(*os_context_register_addr(context, reg_OCFP));
347 /* We can't tell whether we are still in the caller if it had to
348 * allocate a stack frame due to stack arguments. */
349 /* This observation provoked some past CMUCL maintainer to ask
350 * "Can anything strange happen during return?" */
353 oldcont = (lispobj)(*os_context_register_addr(context, reg_CFP));
356 current_control_stack_pointer = current_control_frame_pointer + 8;
358 current_control_frame_pointer[0] = oldcont;
359 current_control_frame_pointer[1] = NIL;
360 current_control_frame_pointer[2] =
361 (lispobj)(*os_context_register_addr(context, reg_CODE));
365 /* Stores the context for gc to scavange and builds fake stack
368 fake_foreign_function_call(os_context_t *context)
371 struct thread *thread=arch_os_get_current_thread();
373 /* context_index incrementing must not be interrupted */
374 check_blockables_blocked_or_lose();
376 /* Get current Lisp state from context. */
378 dynamic_space_free_pointer =
379 (lispobj *)(unsigned long)
380 (*os_context_register_addr(context, reg_ALLOC));
381 /* fprintf(stderr,"dynamic_space_free_pointer: %p\n", */
382 /* dynamic_space_free_pointer); */
383 #if defined(LISP_FEATURE_ALPHA) || defined(LISP_FEATURE_MIPS)
384 if ((long)dynamic_space_free_pointer & 1) {
385 lose("dead in fake_foreign_function_call, context = %x\n", context);
388 /* why doesnt PPC and SPARC do something like this: */
389 #if defined(LISP_FEATURE_HPPA)
390 if ((long)dynamic_space_free_pointer & 4) {
391 lose("dead in fake_foreign_function_call, context = %x, d_s_f_p = %x\n", context, dynamic_space_free_pointer);
396 current_binding_stack_pointer =
397 (lispobj *)(unsigned long)
398 (*os_context_register_addr(context, reg_BSP));
401 build_fake_control_stack_frames(thread,context);
403 /* Do dynamic binding of the active interrupt context index
404 * and save the context in the context array. */
406 fixnum_value(SymbolValue(FREE_INTERRUPT_CONTEXT_INDEX,thread));
408 if (context_index >= MAX_INTERRUPTS) {
409 lose("maximum interrupt nesting depth (%d) exceeded\n", MAX_INTERRUPTS);
412 bind_variable(FREE_INTERRUPT_CONTEXT_INDEX,
413 make_fixnum(context_index + 1),thread);
415 thread->interrupt_contexts[context_index] = context;
417 #ifdef FOREIGN_FUNCTION_CALL_FLAG
418 foreign_function_call_active = 1;
422 /* blocks all blockable signals. If you are calling from a signal handler,
423 * the usual signal mask will be restored from the context when the handler
424 * finishes. Otherwise, be careful */
426 undo_fake_foreign_function_call(os_context_t *context)
428 struct thread *thread=arch_os_get_current_thread();
429 /* Block all blockable signals. */
430 block_blockable_signals();
432 #ifdef FOREIGN_FUNCTION_CALL_FLAG
433 foreign_function_call_active = 0;
436 /* Undo dynamic binding of FREE_INTERRUPT_CONTEXT_INDEX */
440 /* Put the dynamic space free pointer back into the context. */
441 *os_context_register_addr(context, reg_ALLOC) =
442 (unsigned long) dynamic_space_free_pointer
443 | (*os_context_register_addr(context, reg_ALLOC)
446 ((unsigned long)(*os_context_register_addr(context, reg_ALLOC))
448 | ((unsigned long) dynamic_space_free_pointer & LOWTAG_MASK);
453 /* a handler for the signal caused by execution of a trap opcode
454 * signalling an internal error */
456 interrupt_internal_error(os_context_t *context, boolean continuable)
460 fake_foreign_function_call(context);
462 if (!internal_errors_enabled) {
463 describe_internal_error(context);
464 /* There's no good way to recover from an internal error
465 * before the Lisp error handling mechanism is set up. */
466 lose("internal error too early in init, can't recover\n");
469 /* Allocate the SAP object while the interrupts are still
471 context_sap = alloc_sap(context);
473 #ifndef LISP_FEATURE_WIN32
474 thread_sigmask(SIG_SETMASK, os_context_sigmask_addr(context), 0);
477 #if defined(LISP_FEATURE_LINUX) && defined(LISP_FEATURE_MIPS)
478 /* Workaround for blocked SIGTRAP. */
481 sigemptyset(&newset);
482 sigaddset(&newset, SIGTRAP);
483 thread_sigmask(SIG_UNBLOCK, &newset, 0);
487 SHOW("in interrupt_internal_error");
489 /* Display some rudimentary debugging information about the
490 * error, so that even if the Lisp error handler gets badly
491 * confused, we have a chance to determine what's going on. */
492 describe_internal_error(context);
494 funcall2(StaticSymbolFunction(INTERNAL_ERROR), context_sap,
495 continuable ? T : NIL);
497 undo_fake_foreign_function_call(context); /* blocks signals again */
499 arch_skip_instruction(context);
503 interrupt_handle_pending(os_context_t *context)
505 /* There are three ways we can get here. First, if an interrupt
506 * occurs within pseudo-atomic, it will be deferred, and we'll
507 * trap to here at the end of the pseudo-atomic block. Second, if
508 * the GC (in alloc()) decides that a GC is required, it will set
509 * *GC-PENDING* and pseudo-atomic-interrupted if not *GC-INHIBIT*,
510 * and alloc() is always called from within pseudo-atomic, and
511 * thus we end up here again. Third, when calling GC-ON or at the
512 * end of a WITHOUT-GCING, MAYBE-HANDLE-PENDING-GC will trap to
513 * here if there is a pending GC. Fourth, ahem, at the end of
514 * WITHOUT-INTERRUPTS (bar complications with nesting). */
516 /* Win32 only needs to handle the GC cases (for now?) */
518 struct thread *thread;
520 if (arch_pseudo_atomic_atomic(context)) {
521 lose("Handling pending interrupt in pseduo atomic.");
524 thread = arch_os_get_current_thread();
526 FSHOW_SIGNAL((stderr, "/entering interrupt_handle_pending\n"));
528 check_blockables_blocked_or_lose();
530 /* If pseudo_atomic_interrupted is set then the interrupt is going
531 * to be handled now, ergo it's safe to clear it. */
532 arch_clear_pseudo_atomic_interrupted(context);
534 if (SymbolValue(GC_INHIBIT,thread)==NIL) {
535 #ifdef LISP_FEATURE_SB_THREAD
536 if (SymbolValue(STOP_FOR_GC_PENDING,thread) != NIL) {
537 /* STOP_FOR_GC_PENDING and GC_PENDING are cleared by
538 * the signal handler if it actually stops us. */
539 sig_stop_for_gc_handler(SIG_STOP_FOR_GC,NULL,context);
542 if (SymbolValue(GC_PENDING,thread) != NIL) {
543 /* GC_PENDING is cleared in SUB-GC, or if another thread
544 * is doing a gc already we will get a SIG_STOP_FOR_GC and
545 * that will clear it. */
548 check_blockables_blocked_or_lose();
551 #ifndef LISP_FEATURE_WIN32
552 /* we may be here only to do the gc stuff, if interrupts are
553 * enabled run the pending handler */
554 if (SymbolValue(INTERRUPTS_ENABLED,thread) != NIL) {
555 struct interrupt_data *data = thread->interrupt_data;
557 /* There may be no pending handler, because it was only a gc
558 * that had to be executed or because pseudo atomic triggered
559 * twice for a single interrupt. For the interested reader,
560 * that may happen if an interrupt hits after the interrupted
561 * flag is cleared but before pseudo-atomic is set and a
562 * pseudo atomic is interrupted in that interrupt. */
563 if (data->pending_handler) {
565 /* If we're here as the result of a pseudo-atomic as opposed
566 * to WITHOUT-INTERRUPTS, then INTERRUPT_PENDING is already
567 * NIL, because maybe_defer_handler sets
568 * PSEUDO_ATOMIC_INTERRUPTED only if interrupts are enabled.*/
569 SetSymbolValue(INTERRUPT_PENDING, NIL, thread);
571 /* restore the saved signal mask from the original signal (the
572 * one that interrupted us during the critical section) into the
573 * os_context for the signal we're currently in the handler for.
574 * This should ensure that when we return from the handler the
575 * blocked signals are unblocked */
576 sigcopyset(os_context_sigmask_addr(context), &data->pending_mask);
578 /* This will break on sparc linux: the deferred handler really wants
579 * to be called with a void_context */
580 run_deferred_handler(data,(void *)context);
587 * the two main signal handlers:
588 * interrupt_handle_now(..)
589 * maybe_now_maybe_later(..)
591 * to which we have added interrupt_handle_now_handler(..). Why?
592 * Well, mostly because the SPARC/Linux platform doesn't quite do
593 * signals the way we want them done. The third argument in the
594 * handler isn't filled in by the kernel properly, so we fix it up
595 * ourselves in the arch_os_get_context(..) function; however, we only
596 * want to do this when we first hit the handler, and not when
597 * interrupt_handle_now(..) is being called from some other handler
598 * (when the fixup will already have been done). -- CSR, 2002-07-23
602 interrupt_handle_now(int signal, siginfo_t *info, os_context_t *context)
604 #ifdef FOREIGN_FUNCTION_CALL_FLAG
605 boolean were_in_lisp;
607 union interrupt_handler handler;
609 check_blockables_blocked_or_lose();
611 #ifndef LISP_FEATURE_WIN32
612 if (sigismember(&deferrable_sigset,signal))
613 check_interrupts_enabled_or_lose(context);
616 #if defined(LISP_FEATURE_LINUX) || defined(RESTORE_FP_CONTROL_FROM_CONTEXT)
617 /* Under Linux on some architectures, we appear to have to restore
618 the FPU control word from the context, as after the signal is
619 delivered we appear to have a null FPU control word. */
620 os_restore_fp_control(context);
623 handler = interrupt_handlers[signal];
625 if (ARE_SAME_HANDLER(handler.c, SIG_IGN)) {
629 #ifdef FOREIGN_FUNCTION_CALL_FLAG
630 were_in_lisp = !foreign_function_call_active;
634 fake_foreign_function_call(context);
637 FSHOW_SIGNAL((stderr,
638 "/entering interrupt_handle_now(%d, info, context)\n",
641 if (ARE_SAME_HANDLER(handler.c, SIG_DFL)) {
643 /* This can happen if someone tries to ignore or default one
644 * of the signals we need for runtime support, and the runtime
645 * support decides to pass on it. */
646 lose("no handler for signal %d in interrupt_handle_now(..)\n", signal);
648 } else if (lowtag_of(handler.lisp) == FUN_POINTER_LOWTAG) {
649 /* Once we've decided what to do about contexts in a
650 * return-elsewhere world (the original context will no longer
651 * be available; should we copy it or was nobody using it anyway?)
652 * then we should convert this to return-elsewhere */
654 /* CMUCL comment said "Allocate the SAPs while the interrupts
655 * are still disabled.". I (dan, 2003.08.21) assume this is
656 * because we're not in pseudoatomic and allocation shouldn't
657 * be interrupted. In which case it's no longer an issue as
658 * all our allocation from C now goes through a PA wrapper,
659 * but still, doesn't hurt.
661 * Yeah, but non-gencgc platforms don't really wrap allocation
662 * in PA. MG - 2005-08-29 */
664 lispobj info_sap,context_sap = alloc_sap(context);
665 info_sap = alloc_sap(info);
666 /* Leave deferrable signals blocked, the handler itself will
667 * allow signals again when it sees fit. */
668 #ifdef LISP_FEATURE_SB_THREAD
671 sigemptyset(&unblock);
672 sigaddset(&unblock, SIG_STOP_FOR_GC);
673 #ifdef SIG_RESUME_FROM_GC
674 sigaddset(&unblock, SIG_RESUME_FROM_GC);
676 thread_sigmask(SIG_UNBLOCK, &unblock, 0);
680 FSHOW_SIGNAL((stderr,"/calling Lisp-level handler\n"));
682 funcall3(handler.lisp,
688 FSHOW_SIGNAL((stderr,"/calling C-level handler\n"));
690 #ifndef LISP_FEATURE_WIN32
691 /* Allow signals again. */
692 thread_sigmask(SIG_SETMASK, os_context_sigmask_addr(context), 0);
694 (*handler.c)(signal, info, context);
697 #ifdef FOREIGN_FUNCTION_CALL_FLAG
701 undo_fake_foreign_function_call(context); /* block signals again */
704 FSHOW_SIGNAL((stderr,
705 "/returning from interrupt_handle_now(%d, info, context)\n",
709 /* This is called at the end of a critical section if the indications
710 * are that some signal was deferred during the section. Note that as
711 * far as C or the kernel is concerned we dealt with the signal
712 * already; we're just doing the Lisp-level processing now that we
715 run_deferred_handler(struct interrupt_data *data, void *v_context)
717 /* The pending_handler may enable interrupts and then another
718 * interrupt may hit, overwrite interrupt_data, so reset the
719 * pending handler before calling it. Trust the handler to finish
720 * with the siginfo before enabling interrupts. */
721 void (*pending_handler) (int, siginfo_t*, void*)=data->pending_handler;
723 data->pending_handler=0;
724 (*pending_handler)(data->pending_signal,&(data->pending_info), v_context);
727 #ifndef LISP_FEATURE_WIN32
729 maybe_defer_handler(void *handler, struct interrupt_data *data,
730 int signal, siginfo_t *info, os_context_t *context)
732 struct thread *thread=arch_os_get_current_thread();
734 check_blockables_blocked_or_lose();
736 if (SymbolValue(INTERRUPT_PENDING,thread) != NIL)
737 lose("interrupt already pending\n");
738 check_interrupt_context_or_lose(context);
739 /* If interrupts are disabled then INTERRUPT_PENDING is set and
740 * not PSEDUO_ATOMIC_INTERRUPTED. This is important for a pseudo
741 * atomic section inside a WITHOUT-INTERRUPTS.
743 * Also, if in_leaving_without_gcing_race_p then
744 * interrupt_handle_pending is going to be called soon, so
745 * stashing the signal away is safe.
747 if ((SymbolValue(INTERRUPTS_ENABLED,thread) == NIL) ||
748 in_leaving_without_gcing_race_p(thread)) {
749 store_signal_data_for_later(data,handler,signal,info,context);
750 SetSymbolValue(INTERRUPT_PENDING, T,thread);
751 FSHOW_SIGNAL((stderr,
752 "/maybe_defer_handler(%x,%d): deferred\n",
753 (unsigned int)handler,signal));
754 check_interrupt_context_or_lose(context);
757 /* a slightly confusing test. arch_pseudo_atomic_atomic() doesn't
758 * actually use its argument for anything on x86, so this branch
759 * may succeed even when context is null (gencgc alloc()) */
760 if (arch_pseudo_atomic_atomic(context)) {
761 store_signal_data_for_later(data,handler,signal,info,context);
762 arch_set_pseudo_atomic_interrupted(context);
763 FSHOW_SIGNAL((stderr,
764 "/maybe_defer_handler(%x,%d): deferred(PA)\n",
765 (unsigned int)handler,signal));
766 check_interrupt_context_or_lose(context);
769 FSHOW_SIGNAL((stderr,
770 "/maybe_defer_handler(%x,%d): not deferred\n",
771 (unsigned int)handler,signal));
776 store_signal_data_for_later (struct interrupt_data *data, void *handler,
778 siginfo_t *info, os_context_t *context)
780 if (data->pending_handler)
781 lose("tried to overwrite pending interrupt handler %x with %x\n",
782 data->pending_handler, handler);
784 lose("tried to defer null interrupt handler\n");
785 data->pending_handler = handler;
786 data->pending_signal = signal;
788 memcpy(&(data->pending_info), info, sizeof(siginfo_t));
790 FSHOW_SIGNAL((stderr, "/store_signal_data_for_later: signal: %d\n",
794 /* the signal mask in the context (from before we were
795 * interrupted) is copied to be restored when
796 * run_deferred_handler happens. Then the usually-blocked
797 * signals are added to the mask in the context so that we are
798 * running with blocked signals when the handler returns */
799 sigcopyset(&(data->pending_mask),os_context_sigmask_addr(context));
800 sigaddset_deferrable(os_context_sigmask_addr(context));
805 maybe_now_maybe_later(int signal, siginfo_t *info, void *void_context)
807 os_context_t *context = arch_os_get_context(&void_context);
808 struct thread *thread = arch_os_get_current_thread();
809 struct interrupt_data *data = thread->interrupt_data;
811 #if defined(LISP_FEATURE_LINUX) || defined(RESTORE_FP_CONTROL_FROM_CONTEXT)
812 os_restore_fp_control(context);
815 if(!maybe_defer_handler(interrupt_handle_now,data,signal,info,context))
816 interrupt_handle_now(signal, info, context);
820 low_level_interrupt_handle_now(int signal, siginfo_t *info,
821 os_context_t *context)
823 /* No FP control fixage needed, caller has done that. */
824 check_blockables_blocked_or_lose();
825 check_interrupts_enabled_or_lose(context);
826 (*interrupt_low_level_handlers[signal])(signal, info, context);
827 /* No Darwin context fixage needed, caller does that. */
831 low_level_maybe_now_maybe_later(int signal, siginfo_t *info, void *void_context)
833 os_context_t *context = arch_os_get_context(&void_context);
834 struct thread *thread = arch_os_get_current_thread();
835 struct interrupt_data *data = thread->interrupt_data;
837 #if defined(LISP_FEATURE_LINUX) || defined(RESTORE_FP_CONTROL_FROM_CONTEXT)
838 os_restore_fp_control(context);
841 if(!maybe_defer_handler(low_level_interrupt_handle_now,data,
842 signal,info,context))
843 low_level_interrupt_handle_now(signal, info, context);
847 #ifdef LISP_FEATURE_SB_THREAD
850 sig_stop_for_gc_handler(int signal, siginfo_t *info, void *void_context)
852 os_context_t *context = arch_os_get_context(&void_context);
854 struct thread *thread=arch_os_get_current_thread();
857 /* Test for GC_INHIBIT _first_, else we'd trap on every single
858 * pseudo atomic until gc is finally allowed. */
859 if (SymbolValue(GC_INHIBIT,thread) != NIL) {
860 SetSymbolValue(STOP_FOR_GC_PENDING,T,thread);
861 FSHOW_SIGNAL((stderr, "sig_stop_for_gc deferred (*GC-INHIBIT*)\n"));
863 } else if (arch_pseudo_atomic_atomic(context)) {
864 SetSymbolValue(STOP_FOR_GC_PENDING,T,thread);
865 arch_set_pseudo_atomic_interrupted(context);
866 FSHOW_SIGNAL((stderr,"sig_stop_for_gc deferred (PA)\n"));
870 /* Not PA and GC not inhibited -- we can stop now. */
872 /* need the context stored so it can have registers scavenged */
873 fake_foreign_function_call(context);
875 /* Block everything. */
877 thread_sigmask(SIG_BLOCK,&ss,0);
879 /* Not pending anymore. */
880 SetSymbolValue(GC_PENDING,NIL,thread);
881 SetSymbolValue(STOP_FOR_GC_PENDING,NIL,thread);
883 if(thread_state(thread)!=STATE_RUNNING) {
884 lose("sig_stop_for_gc_handler: wrong thread state: %ld\n",
885 fixnum_value(thread->state));
888 set_thread_state(thread,STATE_SUSPENDED);
889 FSHOW_SIGNAL((stderr,"suspended\n"));
891 wait_for_thread_state_change(thread, STATE_SUSPENDED);
892 FSHOW_SIGNAL((stderr,"resumed\n"));
894 if(thread_state(thread)!=STATE_RUNNING) {
895 lose("sig_stop_for_gc_handler: wrong thread state on wakeup: %ld\n",
896 fixnum_value(thread_state(thread)));
899 undo_fake_foreign_function_call(context);
905 interrupt_handle_now_handler(int signal, siginfo_t *info, void *void_context)
907 os_context_t *context = arch_os_get_context(&void_context);
908 #if defined(LISP_FEATURE_LINUX) || defined(RESTORE_FP_CONTROL_FROM_CONTEXT)
909 os_restore_fp_control(context);
910 #ifndef LISP_FEATURE_WIN32
911 if ((signal == SIGILL) || (signal == SIGBUS)
912 #ifndef LISP_FEATURE_LINUX
913 || (signal == SIGEMT)
916 corruption_warning_and_maybe_lose("Signal %d recieved", signal);
919 interrupt_handle_now(signal, info, context);
922 /* manipulate the signal context and stack such that when the handler
923 * returns, it will call function instead of whatever it was doing
927 #if (defined(LISP_FEATURE_X86) || defined(LISP_FEATURE_X86_64))
928 extern int *context_eflags_addr(os_context_t *context);
931 extern lispobj call_into_lisp(lispobj fun, lispobj *args, int nargs);
932 extern void post_signal_tramp(void);
933 extern void call_into_lisp_tramp(void);
935 arrange_return_to_lisp_function(os_context_t *context, lispobj function)
937 #if !(defined(LISP_FEATURE_X86) || defined(LISP_FEATURE_X86_64))
938 void * fun=native_pointer(function);
939 void *code = &(((struct simple_fun *) fun)->code);
942 /* Build a stack frame showing `interrupted' so that the
943 * user's backtrace makes (as much) sense (as usual) */
945 /* FIXME: what about restoring fp state? */
946 /* FIXME: what about restoring errno? */
947 #ifdef LISP_FEATURE_X86
948 /* Suppose the existence of some function that saved all
949 * registers, called call_into_lisp, then restored GP registers and
950 * returned. It would look something like this:
958 pushl {address of function to call}
959 call 0x8058db0 <call_into_lisp>
966 * What we do here is set up the stack that call_into_lisp would
967 * expect to see if it had been called by this code, and frob the
968 * signal context so that signal return goes directly to call_into_lisp,
969 * and when that function (and the lisp function it invoked) returns,
970 * it returns to the second half of this imaginary function which
971 * restores all registers and returns to C
973 * For this to work, the latter part of the imaginary function
974 * must obviously exist in reality. That would be post_signal_tramp
977 u32 *sp=(u32 *)*os_context_register_addr(context,reg_ESP);
979 #if defined(LISP_FEATURE_DARWIN)
980 u32 *register_save_area = (u32 *)os_validate(0, 0x40);
982 FSHOW_SIGNAL((stderr, "/arrange_return_to_lisp_function: preparing to go to function %x, sp: %x\n", function, sp));
983 FSHOW_SIGNAL((stderr, "/arrange_return_to_lisp_function: context: %x, &context %x\n", context, &context));
985 /* 1. os_validate (malloc/mmap) register_save_block
986 * 2. copy register state into register_save_block
987 * 3. put a pointer to register_save_block in a register in the context
988 * 4. set the context's EIP to point to a trampoline which:
989 * a. builds the fake stack frame from the block
991 * c. calls the function
994 *register_save_area = *os_context_pc_addr(context);
995 *(register_save_area + 1) = function;
996 *(register_save_area + 2) = *os_context_register_addr(context,reg_EDI);
997 *(register_save_area + 3) = *os_context_register_addr(context,reg_ESI);
998 *(register_save_area + 4) = *os_context_register_addr(context,reg_EDX);
999 *(register_save_area + 5) = *os_context_register_addr(context,reg_ECX);
1000 *(register_save_area + 6) = *os_context_register_addr(context,reg_EBX);
1001 *(register_save_area + 7) = *os_context_register_addr(context,reg_EAX);
1002 *(register_save_area + 8) = *context_eflags_addr(context);
1004 *os_context_pc_addr(context) =
1005 (os_context_register_t) call_into_lisp_tramp;
1006 *os_context_register_addr(context,reg_ECX) =
1007 (os_context_register_t) register_save_area;
1010 /* return address for call_into_lisp: */
1011 *(sp-15) = (u32)post_signal_tramp;
1012 *(sp-14) = function; /* args for call_into_lisp : function*/
1013 *(sp-13) = 0; /* arg array */
1014 *(sp-12) = 0; /* no. args */
1015 /* this order matches that used in POPAD */
1016 *(sp-11)=*os_context_register_addr(context,reg_EDI);
1017 *(sp-10)=*os_context_register_addr(context,reg_ESI);
1019 *(sp-9)=*os_context_register_addr(context,reg_ESP)-8;
1020 /* POPAD ignores the value of ESP: */
1022 *(sp-7)=*os_context_register_addr(context,reg_EBX);
1024 *(sp-6)=*os_context_register_addr(context,reg_EDX);
1025 *(sp-5)=*os_context_register_addr(context,reg_ECX);
1026 *(sp-4)=*os_context_register_addr(context,reg_EAX);
1027 *(sp-3)=*context_eflags_addr(context);
1028 *(sp-2)=*os_context_register_addr(context,reg_EBP);
1029 *(sp-1)=*os_context_pc_addr(context);
1033 #elif defined(LISP_FEATURE_X86_64)
1034 u64 *sp=(u64 *)*os_context_register_addr(context,reg_RSP);
1036 /* return address for call_into_lisp: */
1037 *(sp-18) = (u64)post_signal_tramp;
1039 *(sp-17)=*os_context_register_addr(context,reg_R15);
1040 *(sp-16)=*os_context_register_addr(context,reg_R14);
1041 *(sp-15)=*os_context_register_addr(context,reg_R13);
1042 *(sp-14)=*os_context_register_addr(context,reg_R12);
1043 *(sp-13)=*os_context_register_addr(context,reg_R11);
1044 *(sp-12)=*os_context_register_addr(context,reg_R10);
1045 *(sp-11)=*os_context_register_addr(context,reg_R9);
1046 *(sp-10)=*os_context_register_addr(context,reg_R8);
1047 *(sp-9)=*os_context_register_addr(context,reg_RDI);
1048 *(sp-8)=*os_context_register_addr(context,reg_RSI);
1049 /* skip RBP and RSP */
1050 *(sp-7)=*os_context_register_addr(context,reg_RBX);
1051 *(sp-6)=*os_context_register_addr(context,reg_RDX);
1052 *(sp-5)=*os_context_register_addr(context,reg_RCX);
1053 *(sp-4)=*os_context_register_addr(context,reg_RAX);
1054 *(sp-3)=*context_eflags_addr(context);
1055 *(sp-2)=*os_context_register_addr(context,reg_RBP);
1056 *(sp-1)=*os_context_pc_addr(context);
1058 *os_context_register_addr(context,reg_RDI) =
1059 (os_context_register_t)function; /* function */
1060 *os_context_register_addr(context,reg_RSI) = 0; /* arg. array */
1061 *os_context_register_addr(context,reg_RDX) = 0; /* no. args */
1063 struct thread *th=arch_os_get_current_thread();
1064 build_fake_control_stack_frames(th,context);
1067 #ifdef LISP_FEATURE_X86
1069 #if !defined(LISP_FEATURE_DARWIN)
1070 *os_context_pc_addr(context) = (os_context_register_t)call_into_lisp;
1071 *os_context_register_addr(context,reg_ECX) = 0;
1072 *os_context_register_addr(context,reg_EBP) = (os_context_register_t)(sp-2);
1074 *os_context_register_addr(context,reg_UESP) =
1075 (os_context_register_t)(sp-15);
1077 *os_context_register_addr(context,reg_ESP) = (os_context_register_t)(sp-15);
1078 #endif /* __NETBSD__ */
1079 #endif /* LISP_FEATURE_DARWIN */
1081 #elif defined(LISP_FEATURE_X86_64)
1082 *os_context_pc_addr(context) = (os_context_register_t)call_into_lisp;
1083 *os_context_register_addr(context,reg_RCX) = 0;
1084 *os_context_register_addr(context,reg_RBP) = (os_context_register_t)(sp-2);
1085 *os_context_register_addr(context,reg_RSP) = (os_context_register_t)(sp-18);
1087 /* this much of the calling convention is common to all
1089 *os_context_pc_addr(context) = (os_context_register_t)(unsigned long)code;
1090 *os_context_register_addr(context,reg_NARGS) = 0;
1091 *os_context_register_addr(context,reg_LIP) =
1092 (os_context_register_t)(unsigned long)code;
1093 *os_context_register_addr(context,reg_CFP) =
1094 (os_context_register_t)(unsigned long)current_control_frame_pointer;
1096 #ifdef ARCH_HAS_NPC_REGISTER
1097 *os_context_npc_addr(context) =
1098 4 + *os_context_pc_addr(context);
1100 #ifdef LISP_FEATURE_SPARC
1101 *os_context_register_addr(context,reg_CODE) =
1102 (os_context_register_t)(fun + FUN_POINTER_LOWTAG);
1104 FSHOW((stderr, "/arranged return to Lisp function (0x%lx)\n",
1108 #ifdef LISP_FEATURE_SB_THREAD
1110 /* FIXME: this function can go away when all lisp handlers are invoked
1111 * via arrange_return_to_lisp_function. */
1113 interrupt_thread_handler(int num, siginfo_t *info, void *v_context)
1115 os_context_t *context = (os_context_t*)arch_os_get_context(&v_context);
1117 FSHOW_SIGNAL((stderr,"/interrupt_thread_handler\n"));
1118 check_blockables_blocked_or_lose();
1120 /* let the handler enable interrupts again when it sees fit */
1121 sigaddset_deferrable(os_context_sigmask_addr(context));
1122 arrange_return_to_lisp_function(context,
1123 StaticSymbolFunction(RUN_INTERRUPTION));
1128 /* KLUDGE: Theoretically the approach we use for undefined alien
1129 * variables should work for functions as well, but on PPC/Darwin
1130 * we get bus error at bogus addresses instead, hence this workaround,
1131 * that has the added benefit of automatically discriminating between
1132 * functions and variables.
1135 undefined_alien_function(void)
1137 funcall0(StaticSymbolFunction(UNDEFINED_ALIEN_FUNCTION_ERROR));
1141 handle_guard_page_triggered(os_context_t *context,os_vm_address_t addr)
1143 struct thread *th=arch_os_get_current_thread();
1145 /* note the os_context hackery here. When the signal handler returns,
1146 * it won't go back to what it was doing ... */
1147 if(addr >= CONTROL_STACK_GUARD_PAGE(th) &&
1148 addr < CONTROL_STACK_GUARD_PAGE(th) + os_vm_page_size) {
1149 /* We hit the end of the control stack: disable guard page
1150 * protection so the error handler has some headroom, protect the
1151 * previous page so that we can catch returns from the guard page
1152 * and restore it. */
1153 corruption_warning_and_maybe_lose("Control stack exhausted");
1154 protect_control_stack_guard_page(0);
1155 protect_control_stack_return_guard_page(1);
1157 arrange_return_to_lisp_function
1158 (context, StaticSymbolFunction(CONTROL_STACK_EXHAUSTED_ERROR));
1161 else if(addr >= CONTROL_STACK_RETURN_GUARD_PAGE(th) &&
1162 addr < CONTROL_STACK_RETURN_GUARD_PAGE(th) + os_vm_page_size) {
1163 /* We're returning from the guard page: reprotect it, and
1164 * unprotect this one. This works even if we somehow missed
1165 * the return-guard-page, and hit it on our way to new
1166 * exhaustion instead. */
1167 protect_control_stack_guard_page(1);
1168 protect_control_stack_return_guard_page(0);
1171 else if (addr >= undefined_alien_address &&
1172 addr < undefined_alien_address + os_vm_page_size) {
1173 arrange_return_to_lisp_function
1174 (context, StaticSymbolFunction(UNDEFINED_ALIEN_VARIABLE_ERROR));
1181 * noise to install handlers
1184 #ifndef LISP_FEATURE_WIN32
1185 /* In Linux 2.4 synchronous signals (sigtrap & co) can be delivered if
1186 * they are blocked, in Linux 2.6 the default handler is invoked
1187 * instead that usually coredumps. One might hastily think that adding
1188 * SA_NODEFER helps, but until ~2.6.13 if SA_NODEFER is specified then
1189 * the whole sa_mask is ignored and instead of not adding the signal
1190 * in question to the mask. That means if it's not blockable the
1191 * signal must be unblocked at the beginning of signal handlers.
1193 * It turns out that NetBSD's SA_NODEFER doesn't DTRT in a different
1194 * way: if SA_NODEFER is set and the signal is in sa_mask, the signal
1195 * will be unblocked in the sigmask during the signal handler. -- RMK
1198 static volatile int sigaction_nodefer_works = -1;
1200 #define SA_NODEFER_TEST_BLOCK_SIGNAL SIGABRT
1201 #define SA_NODEFER_TEST_KILL_SIGNAL SIGUSR1
1204 sigaction_nodefer_test_handler(int signal, siginfo_t *info, void *void_context)
1206 sigset_t empty, current;
1208 sigemptyset(&empty);
1209 thread_sigmask(SIG_BLOCK, &empty, ¤t);
1210 /* There should be exactly two blocked signals: the two we added
1211 * to sa_mask when setting up the handler. NetBSD doesn't block
1212 * the signal we're handling when SA_NODEFER is set; Linux before
1213 * 2.6.13 or so also doesn't block the other signal when
1214 * SA_NODEFER is set. */
1215 for(i = 1; i < NSIG; i++)
1216 if (sigismember(¤t, i) !=
1217 (((i == SA_NODEFER_TEST_BLOCK_SIGNAL) || (i == signal)) ? 1 : 0)) {
1218 FSHOW_SIGNAL((stderr, "SA_NODEFER doesn't work, signal %d\n", i));
1219 sigaction_nodefer_works = 0;
1221 if (sigaction_nodefer_works == -1)
1222 sigaction_nodefer_works = 1;
1226 see_if_sigaction_nodefer_works(void)
1228 struct sigaction sa, old_sa;
1230 sa.sa_flags = SA_SIGINFO | SA_NODEFER;
1231 sa.sa_sigaction = sigaction_nodefer_test_handler;
1232 sigemptyset(&sa.sa_mask);
1233 sigaddset(&sa.sa_mask, SA_NODEFER_TEST_BLOCK_SIGNAL);
1234 sigaddset(&sa.sa_mask, SA_NODEFER_TEST_KILL_SIGNAL);
1235 sigaction(SA_NODEFER_TEST_KILL_SIGNAL, &sa, &old_sa);
1236 /* Make sure no signals are blocked. */
1239 sigemptyset(&empty);
1240 thread_sigmask(SIG_SETMASK, &empty, 0);
1242 kill(getpid(), SA_NODEFER_TEST_KILL_SIGNAL);
1243 while (sigaction_nodefer_works == -1);
1244 sigaction(SA_NODEFER_TEST_KILL_SIGNAL, &old_sa, NULL);
1247 #undef SA_NODEFER_TEST_BLOCK_SIGNAL
1248 #undef SA_NODEFER_TEST_KILL_SIGNAL
1251 unblock_me_trampoline(int signal, siginfo_t *info, void *void_context)
1255 sigemptyset(&unblock);
1256 sigaddset(&unblock, signal);
1257 thread_sigmask(SIG_UNBLOCK, &unblock, 0);
1258 interrupt_handle_now_handler(signal, info, void_context);
1262 low_level_unblock_me_trampoline(int signal, siginfo_t *info, void *void_context)
1266 sigemptyset(&unblock);
1267 sigaddset(&unblock, signal);
1268 thread_sigmask(SIG_UNBLOCK, &unblock, 0);
1269 (*interrupt_low_level_handlers[signal])(signal, info, void_context);
1273 undoably_install_low_level_interrupt_handler (int signal,
1274 interrupt_handler_t handler)
1276 struct sigaction sa;
1278 if (0 > signal || signal >= NSIG) {
1279 lose("bad signal number %d\n", signal);
1282 if (ARE_SAME_HANDLER(handler, SIG_DFL))
1283 sa.sa_sigaction = handler;
1284 else if (sigismember(&deferrable_sigset,signal))
1285 sa.sa_sigaction = low_level_maybe_now_maybe_later;
1286 /* The use of a trampoline appears to break the
1287 arch_os_get_context() workaround for SPARC/Linux. For now,
1288 don't use the trampoline (and so be vulnerable to the problems
1289 that SA_NODEFER is meant to solve. */
1290 #if !(defined(LISP_FEATURE_SPARC) && defined(LISP_FEATURE_LINUX))
1291 else if (!sigaction_nodefer_works &&
1292 !sigismember(&blockable_sigset, signal))
1293 sa.sa_sigaction = low_level_unblock_me_trampoline;
1296 sa.sa_sigaction = handler;
1298 sigcopyset(&sa.sa_mask, &blockable_sigset);
1299 sa.sa_flags = SA_SIGINFO | SA_RESTART
1300 | (sigaction_nodefer_works ? SA_NODEFER : 0);
1301 #ifdef LISP_FEATURE_C_STACK_IS_CONTROL_STACK
1302 if((signal==SIG_MEMORY_FAULT)
1303 #ifdef SIG_INTERRUPT_THREAD
1304 || (signal==SIG_INTERRUPT_THREAD)
1307 sa.sa_flags |= SA_ONSTACK;
1310 sigaction(signal, &sa, NULL);
1311 interrupt_low_level_handlers[signal] =
1312 (ARE_SAME_HANDLER(handler, SIG_DFL) ? 0 : handler);
1316 /* This is called from Lisp. */
1318 install_handler(int signal, void handler(int, siginfo_t*, void*))
1320 #ifndef LISP_FEATURE_WIN32
1321 struct sigaction sa;
1323 union interrupt_handler oldhandler;
1325 FSHOW((stderr, "/entering POSIX install_handler(%d, ..)\n", signal));
1328 sigaddset(&new, signal);
1329 thread_sigmask(SIG_BLOCK, &new, &old);
1331 FSHOW((stderr, "/interrupt_low_level_handlers[signal]=%x\n",
1332 (unsigned int)interrupt_low_level_handlers[signal]));
1333 if (interrupt_low_level_handlers[signal]==0) {
1334 if (ARE_SAME_HANDLER(handler, SIG_DFL) ||
1335 ARE_SAME_HANDLER(handler, SIG_IGN))
1336 sa.sa_sigaction = handler;
1337 else if (sigismember(&deferrable_sigset, signal))
1338 sa.sa_sigaction = maybe_now_maybe_later;
1339 else if (!sigaction_nodefer_works &&
1340 !sigismember(&blockable_sigset, signal))
1341 sa.sa_sigaction = unblock_me_trampoline;
1343 sa.sa_sigaction = interrupt_handle_now_handler;
1345 sigcopyset(&sa.sa_mask, &blockable_sigset);
1346 sa.sa_flags = SA_SIGINFO | SA_RESTART |
1347 (sigaction_nodefer_works ? SA_NODEFER : 0);
1348 sigaction(signal, &sa, NULL);
1351 oldhandler = interrupt_handlers[signal];
1352 interrupt_handlers[signal].c = handler;
1354 thread_sigmask(SIG_SETMASK, &old, 0);
1356 FSHOW((stderr, "/leaving POSIX install_handler(%d, ..)\n", signal));
1358 return (unsigned long)oldhandler.lisp;
1360 /* Probably-wrong Win32 hack */
1365 /* This must not go through lisp as it's allowed anytime, even when on
1368 sigabrt_handler(int signal, siginfo_t *info, void *void_context)
1370 lose("SIGABRT received.\n");
1374 interrupt_init(void)
1376 #ifndef LISP_FEATURE_WIN32
1378 SHOW("entering interrupt_init()");
1379 see_if_sigaction_nodefer_works();
1380 sigemptyset(&deferrable_sigset);
1381 sigemptyset(&blockable_sigset);
1382 sigaddset_deferrable(&deferrable_sigset);
1383 sigaddset_blockable(&blockable_sigset);
1385 /* Set up high level handler information. */
1386 for (i = 0; i < NSIG; i++) {
1387 interrupt_handlers[i].c =
1388 /* (The cast here blasts away the distinction between
1389 * SA_SIGACTION-style three-argument handlers and
1390 * signal(..)-style one-argument handlers, which is OK
1391 * because it works to call the 1-argument form where the
1392 * 3-argument form is expected.) */
1393 (void (*)(int, siginfo_t*, void*))SIG_DFL;
1395 undoably_install_low_level_interrupt_handler(SIGABRT, sigabrt_handler);
1396 SHOW("returning from interrupt_init()");
1400 #ifndef LISP_FEATURE_WIN32
1402 siginfo_code(siginfo_t *info)
1404 return info->si_code;
1406 os_vm_address_t current_memory_fault_address;
1409 lisp_memory_fault_error(os_context_t *context, os_vm_address_t addr)
1411 /* FIXME: This is lossy: if we get another memory fault (eg. from
1412 * another thread) before lisp has read this, we lose the information.
1413 * However, since this is mostly informative, we'll live with that for
1414 * now -- some address is better then no address in this case.
1416 current_memory_fault_address = addr;
1417 /* To allow debugging memory faults in signal handlers and such. */
1418 corruption_warning_and_maybe_lose("Memory fault");
1419 arrange_return_to_lisp_function(context,
1420 StaticSymbolFunction(MEMORY_FAULT_ERROR));
1425 unhandled_trap_error(os_context_t *context)
1427 lispobj context_sap;
1428 fake_foreign_function_call(context);
1429 context_sap = alloc_sap(context);
1430 #ifndef LISP_FEATURE_WIN32
1431 thread_sigmask(SIG_SETMASK, os_context_sigmask_addr(context), 0);
1433 funcall1(StaticSymbolFunction(UNHANDLED_TRAP_ERROR), context_sap);
1434 lose("UNHANDLED-TRAP-ERROR fell through");
1437 /* Common logic for trapping instructions. How we actually handle each
1438 * case is highly architecture dependent, but the overall shape is
1441 handle_trap(os_context_t *context, int trap)
1444 case trap_PendingInterrupt:
1445 FSHOW((stderr, "/<trap pending interrupt>\n"));
1446 arch_skip_instruction(context);
1447 interrupt_handle_pending(context);
1451 FSHOW((stderr, "/<trap error/cerror %d>\n", trap));
1452 interrupt_internal_error(context, trap==trap_Cerror);
1454 case trap_Breakpoint:
1455 arch_handle_breakpoint(context);
1457 case trap_FunEndBreakpoint:
1458 arch_handle_fun_end_breakpoint(context);
1460 #ifdef trap_AfterBreakpoint
1461 case trap_AfterBreakpoint:
1462 arch_handle_after_breakpoint(context);
1465 #ifdef trap_SingleStepAround
1466 case trap_SingleStepAround:
1467 case trap_SingleStepBefore:
1468 arch_handle_single_step_trap(context, trap);
1472 fake_foreign_function_call(context);
1473 lose("%%PRIMITIVE HALT called; the party is over.\n");
1475 unhandled_trap_error(context);