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 "genesis/fdefn.h"
67 #include "genesis/simple-fun.h"
68 #include "genesis/cons.h"
72 static void run_deferred_handler(struct interrupt_data *data, void *v_context);
73 #ifndef LISP_FEATURE_WIN32
74 static void store_signal_data_for_later (struct interrupt_data *data,
75 void *handler, int signal,
77 os_context_t *context);
78 boolean interrupt_maybe_gc_int(int signal, siginfo_t *info, void *v_context);
81 sigaddset_deferrable(sigset_t *s)
85 sigaddset(s, SIGQUIT);
86 sigaddset(s, SIGPIPE);
87 sigaddset(s, SIGALRM);
89 sigaddset(s, SIGTSTP);
90 sigaddset(s, SIGCHLD);
92 sigaddset(s, SIGXCPU);
93 sigaddset(s, SIGXFSZ);
94 sigaddset(s, SIGVTALRM);
95 sigaddset(s, SIGPROF);
96 sigaddset(s, SIGWINCH);
98 #if !((defined(LISP_FEATURE_DARWIN) || defined(LISP_FEATURE_FREEBSD)) && defined(LISP_FEATURE_SB_THREAD))
99 sigaddset(s, SIGUSR1);
100 sigaddset(s, SIGUSR2);
103 #ifdef LISP_FEATURE_SB_THREAD
104 sigaddset(s, SIG_INTERRUPT_THREAD);
109 sigaddset_blockable(sigset_t *s)
111 sigaddset_deferrable(s);
112 #ifdef LISP_FEATURE_SB_THREAD
113 #ifdef SIG_RESUME_FROM_GC
114 sigaddset(s, SIG_RESUME_FROM_GC);
116 sigaddset(s, SIG_STOP_FOR_GC);
120 /* initialized in interrupt_init */
121 static sigset_t deferrable_sigset;
122 static sigset_t blockable_sigset;
126 check_blockables_blocked_or_lose(void)
128 #if !defined(LISP_FEATURE_WIN32)
129 /* Get the current sigmask, by blocking the empty set. */
130 sigset_t empty,current;
133 thread_sigmask(SIG_BLOCK, &empty, ¤t);
134 for(i = 1; i < NSIG; i++) {
135 if (sigismember(&blockable_sigset, i) && !sigismember(¤t, i))
136 lose("blockable signal %d not blocked\n",i);
142 check_gc_signals_unblocked_or_lose(void)
144 #ifdef LISP_FEATURE_SB_THREAD
145 # if !defined(LISP_FEATURE_WIN32)
146 /* Get the current sigmask, by blocking the empty set. */
147 sigset_t empty,current;
149 thread_sigmask(SIG_BLOCK, &empty, ¤t);
150 if (sigismember(¤t, SIG_STOP_FOR_GC))
151 lose("SIG_STOP_FOR_GC blocked in thread %p at a bad place\n",
152 arch_os_get_current_thread());
153 # if defined(SIG_RESUME_FROM_GC)
154 if (sigismember(¤t, SIG_RESUME_FROM_GC))
155 lose("SIG_RESUME_FROM_GC blocked in thread %p at a bad place\n",
156 arch_os_get_current_thread());
163 unblock_gc_signals(void)
165 #ifdef LISP_FEATURE_SB_THREAD
168 #if defined(SIG_RESUME_FROM_GC)
169 sigaddset(&new,SIG_RESUME_FROM_GC);
171 sigaddset(&new,SIG_STOP_FOR_GC);
172 thread_sigmask(SIG_UNBLOCK,&new,0);
177 check_interrupts_enabled_or_lose(os_context_t *context)
179 struct thread *thread=arch_os_get_current_thread();
180 if (SymbolValue(INTERRUPTS_ENABLED,thread) == NIL)
181 lose("interrupts not enabled\n");
183 #if !defined(LISP_FEATURE_X86) && !defined(LISP_FEATURE_X86_64)
184 (!foreign_function_call_active) &&
186 arch_pseudo_atomic_atomic(context))
187 lose ("in pseudo atomic section\n");
190 /* When we catch an internal error, should we pass it back to Lisp to
191 * be handled in a high-level way? (Early in cold init, the answer is
192 * 'no', because Lisp is still too brain-dead to handle anything.
193 * After sufficient initialization has been completed, the answer
195 boolean internal_errors_enabled = 0;
197 #ifndef LISP_FEATURE_WIN32
198 static void (*interrupt_low_level_handlers[NSIG]) (int, siginfo_t*, void*);
200 union interrupt_handler interrupt_handlers[NSIG];
202 /* At the toplevel repl we routinely call this function. The signal
203 * mask ought to be clear anyway most of the time, but may be non-zero
204 * if we were interrupted e.g. while waiting for a queue. */
207 reset_signal_mask(void)
209 #ifndef LISP_FEATURE_WIN32
212 thread_sigmask(SIG_SETMASK,&new,0);
217 block_blockable_signals(void)
219 #ifndef LISP_FEATURE_WIN32
220 thread_sigmask(SIG_BLOCK, &blockable_sigset, 0);
225 block_deferrable_signals(void)
227 #ifndef LISP_FEATURE_WIN32
228 thread_sigmask(SIG_BLOCK, &deferrable_sigset, 0);
234 * utility routines used by various signal handlers
238 build_fake_control_stack_frames(struct thread *th,os_context_t *context)
240 #ifndef LISP_FEATURE_C_STACK_IS_CONTROL_STACK
244 /* Build a fake stack frame or frames */
246 current_control_frame_pointer =
247 (lispobj *)(unsigned long)
248 (*os_context_register_addr(context, reg_CSP));
249 if ((lispobj *)(unsigned long)
250 (*os_context_register_addr(context, reg_CFP))
251 == current_control_frame_pointer) {
252 /* There is a small window during call where the callee's
253 * frame isn't built yet. */
254 if (lowtag_of(*os_context_register_addr(context, reg_CODE))
255 == FUN_POINTER_LOWTAG) {
256 /* We have called, but not built the new frame, so
257 * build it for them. */
258 current_control_frame_pointer[0] =
259 *os_context_register_addr(context, reg_OCFP);
260 current_control_frame_pointer[1] =
261 *os_context_register_addr(context, reg_LRA);
262 current_control_frame_pointer += 8;
263 /* Build our frame on top of it. */
264 oldcont = (lispobj)(*os_context_register_addr(context, reg_CFP));
267 /* We haven't yet called, build our frame as if the
268 * partial frame wasn't there. */
269 oldcont = (lispobj)(*os_context_register_addr(context, reg_OCFP));
272 /* We can't tell whether we are still in the caller if it had to
273 * allocate a stack frame due to stack arguments. */
274 /* This observation provoked some past CMUCL maintainer to ask
275 * "Can anything strange happen during return?" */
278 oldcont = (lispobj)(*os_context_register_addr(context, reg_CFP));
281 current_control_stack_pointer = current_control_frame_pointer + 8;
283 current_control_frame_pointer[0] = oldcont;
284 current_control_frame_pointer[1] = NIL;
285 current_control_frame_pointer[2] =
286 (lispobj)(*os_context_register_addr(context, reg_CODE));
290 /* Stores the context for gc to scavange and builds fake stack
293 fake_foreign_function_call(os_context_t *context)
296 struct thread *thread=arch_os_get_current_thread();
298 /* context_index incrementing must not be interrupted */
299 check_blockables_blocked_or_lose();
301 /* Get current Lisp state from context. */
303 dynamic_space_free_pointer =
304 (lispobj *)(unsigned long)
305 (*os_context_register_addr(context, reg_ALLOC));
306 /* fprintf(stderr,"dynamic_space_free_pointer: %p\n", dynamic_space_free_pointer); */
307 #if defined(LISP_FEATURE_ALPHA)
308 if ((long)dynamic_space_free_pointer & 1) {
309 lose("dead in fake_foreign_function_call, context = %x\n", context);
314 current_binding_stack_pointer =
315 (lispobj *)(unsigned long)
316 (*os_context_register_addr(context, reg_BSP));
319 build_fake_control_stack_frames(thread,context);
321 /* Do dynamic binding of the active interrupt context index
322 * and save the context in the context array. */
324 fixnum_value(SymbolValue(FREE_INTERRUPT_CONTEXT_INDEX,thread));
326 if (context_index >= MAX_INTERRUPTS) {
327 lose("maximum interrupt nesting depth (%d) exceeded\n", MAX_INTERRUPTS);
330 bind_variable(FREE_INTERRUPT_CONTEXT_INDEX,
331 make_fixnum(context_index + 1),thread);
333 thread->interrupt_contexts[context_index] = context;
335 /* no longer in Lisp now */
336 foreign_function_call_active = 1;
339 /* blocks all blockable signals. If you are calling from a signal handler,
340 * the usual signal mask will be restored from the context when the handler
341 * finishes. Otherwise, be careful */
343 undo_fake_foreign_function_call(os_context_t *context)
345 struct thread *thread=arch_os_get_current_thread();
346 /* Block all blockable signals. */
347 block_blockable_signals();
349 /* going back into Lisp */
350 foreign_function_call_active = 0;
352 /* Undo dynamic binding of FREE_INTERRUPT_CONTEXT_INDEX */
356 /* Put the dynamic space free pointer back into the context. */
357 *os_context_register_addr(context, reg_ALLOC) =
358 (unsigned long) dynamic_space_free_pointer
359 | (*os_context_register_addr(context, reg_ALLOC)
362 ((unsigned long)(*os_context_register_addr(context, reg_ALLOC)) & ~LOWTAG_MASK)
363 | ((unsigned long) dynamic_space_free_pointer & LOWTAG_MASK);
368 /* a handler for the signal caused by execution of a trap opcode
369 * signalling an internal error */
371 interrupt_internal_error(int signal, siginfo_t *info, os_context_t *context,
376 fake_foreign_function_call(context);
378 if (!internal_errors_enabled) {
379 describe_internal_error(context);
380 /* There's no good way to recover from an internal error
381 * before the Lisp error handling mechanism is set up. */
382 lose("internal error too early in init, can't recover\n");
385 /* Allocate the SAP object while the interrupts are still
387 context_sap = alloc_sap(context);
389 #ifndef LISP_FEATURE_WIN32
390 thread_sigmask(SIG_SETMASK, os_context_sigmask_addr(context), 0);
393 SHOW("in interrupt_internal_error");
395 /* Display some rudimentary debugging information about the
396 * error, so that even if the Lisp error handler gets badly
397 * confused, we have a chance to determine what's going on. */
398 describe_internal_error(context);
400 funcall2(SymbolFunction(INTERNAL_ERROR), context_sap,
401 continuable ? T : NIL);
403 undo_fake_foreign_function_call(context); /* blocks signals again */
405 arch_skip_instruction(context);
409 interrupt_handle_pending(os_context_t *context)
411 struct thread *thread;
412 struct interrupt_data *data;
414 FSHOW_SIGNAL((stderr, "/entering interrupt_handle_pending\n"));
416 check_blockables_blocked_or_lose();
417 thread=arch_os_get_current_thread();
418 data=thread->interrupt_data;
420 /* If pseudo_atomic_interrupted is set then the interrupt is going
421 * to be handled now, ergo it's safe to clear it. */
422 arch_clear_pseudo_atomic_interrupted(context);
424 if (SymbolValue(GC_INHIBIT,thread)==NIL) {
425 #ifdef LISP_FEATURE_SB_THREAD
426 if (SymbolValue(STOP_FOR_GC_PENDING,thread) != NIL) {
427 /* another thread has already initiated a gc, this attempt
428 * might as well be cancelled */
429 SetSymbolValue(GC_PENDING,NIL,thread);
430 SetSymbolValue(STOP_FOR_GC_PENDING,NIL,thread);
431 sig_stop_for_gc_handler(SIG_STOP_FOR_GC,NULL,context);
434 if (SymbolValue(GC_PENDING,thread) != NIL) {
435 /* GC_PENDING is cleared in SUB-GC, or if another thread
436 * is doing a gc already we will get a SIG_STOP_FOR_GC and
437 * that will clear it. */
438 interrupt_maybe_gc_int(0,NULL,context);
440 check_blockables_blocked_or_lose();
443 /* we may be here only to do the gc stuff, if interrupts are
444 * enabled run the pending handler */
445 if (!((SymbolValue(INTERRUPTS_ENABLED,thread) == NIL) ||
447 #if !defined(LISP_FEATURE_X86) && !defined(LISP_FEATURE_X86_64)
448 (!foreign_function_call_active) &&
450 arch_pseudo_atomic_atomic(context)))) {
452 /* There may be no pending handler, because it was only a gc
453 * that had to be executed or because pseudo atomic triggered
454 * twice for a single interrupt. For the interested reader,
455 * that may happen if an interrupt hits after the interrupted
456 * flag is cleared but before pseduo-atomic is set and a
457 * pseudo atomic is interrupted in that interrupt. */
458 if (data->pending_handler) {
460 /* If we're here as the result of a pseudo-atomic as opposed
461 * to WITHOUT-INTERRUPTS, then INTERRUPT_PENDING is already
462 * NIL, because maybe_defer_handler sets
463 * PSEUDO_ATOMIC_INTERRUPTED only if interrupts are enabled.*/
464 SetSymbolValue(INTERRUPT_PENDING, NIL,thread);
466 #ifndef LISP_FEATURE_WIN32
467 /* restore the saved signal mask from the original signal (the
468 * one that interrupted us during the critical section) into the
469 * os_context for the signal we're currently in the handler for.
470 * This should ensure that when we return from the handler the
471 * blocked signals are unblocked */
472 sigcopyset(os_context_sigmask_addr(context), &data->pending_mask);
474 sigemptyset(&data->pending_mask);
476 /* This will break on sparc linux: the deferred handler really wants
477 * to be called with a void_context */
478 run_deferred_handler(data,(void *)context);
484 * the two main signal handlers:
485 * interrupt_handle_now(..)
486 * maybe_now_maybe_later(..)
488 * to which we have added interrupt_handle_now_handler(..). Why?
489 * Well, mostly because the SPARC/Linux platform doesn't quite do
490 * signals the way we want them done. The third argument in the
491 * handler isn't filled in by the kernel properly, so we fix it up
492 * ourselves in the arch_os_get_context(..) function; however, we only
493 * want to do this when we first hit the handler, and not when
494 * interrupt_handle_now(..) is being called from some other handler
495 * (when the fixup will already have been done). -- CSR, 2002-07-23
499 interrupt_handle_now(int signal, siginfo_t *info, void *void_context)
501 os_context_t *context = (os_context_t*)void_context;
502 #if !defined(LISP_FEATURE_X86) && !defined(LISP_FEATURE_X86_64)
503 boolean were_in_lisp;
505 union interrupt_handler handler;
507 check_blockables_blocked_or_lose();
510 #ifndef LISP_FEATURE_WIN32
511 if (sigismember(&deferrable_sigset,signal))
512 check_interrupts_enabled_or_lose(context);
515 #if defined(LISP_FEATURE_LINUX) || defined(RESTORE_FP_CONTROL_FROM_CONTEXT)
516 /* Under Linux on some architectures, we appear to have to restore
517 the FPU control word from the context, as after the signal is
518 delivered we appear to have a null FPU control word. */
519 os_restore_fp_control(context);
523 handler = interrupt_handlers[signal];
525 if (ARE_SAME_HANDLER(handler.c, SIG_IGN)) {
529 #if !defined(LISP_FEATURE_X86) && !defined(LISP_FEATURE_X86_64)
530 were_in_lisp = !foreign_function_call_active;
534 fake_foreign_function_call(context);
537 FSHOW_SIGNAL((stderr,
538 "/entering interrupt_handle_now(%d, info, context)\n",
541 if (ARE_SAME_HANDLER(handler.c, SIG_DFL)) {
543 /* This can happen if someone tries to ignore or default one
544 * of the signals we need for runtime support, and the runtime
545 * support decides to pass on it. */
546 lose("no handler for signal %d in interrupt_handle_now(..)\n", signal);
548 } else if (lowtag_of(handler.lisp) == FUN_POINTER_LOWTAG) {
549 /* Once we've decided what to do about contexts in a
550 * return-elsewhere world (the original context will no longer
551 * be available; should we copy it or was nobody using it anyway?)
552 * then we should convert this to return-elsewhere */
554 /* CMUCL comment said "Allocate the SAPs while the interrupts
555 * are still disabled.". I (dan, 2003.08.21) assume this is
556 * because we're not in pseudoatomic and allocation shouldn't
557 * be interrupted. In which case it's no longer an issue as
558 * all our allocation from C now goes through a PA wrapper,
559 * but still, doesn't hurt.
561 * Yeah, but non-gencgc platforms don't really wrap allocation
562 * in PA. MG - 2005-08-29 */
564 lispobj info_sap,context_sap = alloc_sap(context);
565 info_sap = alloc_sap(info);
566 /* Leave deferrable signals blocked, the handler itself will
567 * allow signals again when it sees fit. */
568 #ifdef LISP_FEATURE_SB_THREAD
571 sigemptyset(&unblock);
572 sigaddset(&unblock, SIG_STOP_FOR_GC);
573 #ifdef SIG_RESUME_FROM_GC
574 sigaddset(&unblock, SIG_RESUME_FROM_GC);
576 thread_sigmask(SIG_UNBLOCK, &unblock, 0);
580 FSHOW_SIGNAL((stderr,"/calling Lisp-level handler\n"));
582 funcall3(handler.lisp,
588 FSHOW_SIGNAL((stderr,"/calling C-level handler\n"));
590 #ifndef LISP_FEATURE_WIN32
591 /* Allow signals again. */
592 thread_sigmask(SIG_SETMASK, os_context_sigmask_addr(context), 0);
595 (*handler.c)(signal, info, void_context);
598 #if !defined(LISP_FEATURE_X86) && !defined(LISP_FEATURE_X86_64)
602 undo_fake_foreign_function_call(context); /* block signals again */
605 FSHOW_SIGNAL((stderr,
606 "/returning from interrupt_handle_now(%d, info, context)\n",
610 /* This is called at the end of a critical section if the indications
611 * are that some signal was deferred during the section. Note that as
612 * far as C or the kernel is concerned we dealt with the signal
613 * already; we're just doing the Lisp-level processing now that we
616 run_deferred_handler(struct interrupt_data *data, void *v_context) {
617 /* The pending_handler may enable interrupts and then another
618 * interrupt may hit, overwrite interrupt_data, so reset the
619 * pending handler before calling it. Trust the handler to finish
620 * with the siginfo before enabling interrupts. */
621 void (*pending_handler) (int, siginfo_t*, void*)=data->pending_handler;
623 data->pending_handler=0;
624 (*pending_handler)(data->pending_signal,&(data->pending_info), v_context);
627 #ifndef LISP_FEATURE_WIN32
629 maybe_defer_handler(void *handler, struct interrupt_data *data,
630 int signal, siginfo_t *info, os_context_t *context)
632 struct thread *thread=arch_os_get_current_thread();
634 check_blockables_blocked_or_lose();
636 if (SymbolValue(INTERRUPT_PENDING,thread) != NIL)
637 lose("interrupt already pending\n");
638 /* If interrupts are disabled then INTERRUPT_PENDING is set and
639 * not PSEDUO_ATOMIC_INTERRUPTED. This is important for a pseudo
640 * atomic section inside a WITHOUT-INTERRUPTS.
642 if (SymbolValue(INTERRUPTS_ENABLED,thread) == NIL) {
643 store_signal_data_for_later(data,handler,signal,info,context);
644 SetSymbolValue(INTERRUPT_PENDING, T,thread);
645 FSHOW_SIGNAL((stderr,
646 "/maybe_defer_handler(%x,%d),thread=%lu: deferred\n",
647 (unsigned int)handler,signal,
648 (unsigned long)thread->os_thread));
651 /* a slightly confusing test. arch_pseudo_atomic_atomic() doesn't
652 * actually use its argument for anything on x86, so this branch
653 * may succeed even when context is null (gencgc alloc()) */
655 #if !defined(LISP_FEATURE_X86) && !defined(LISP_FEATURE_X86_64)
656 /* FIXME: this foreign_function_call_active test is dubious at
657 * best. If a foreign call is made in a pseudo atomic section
658 * (?) or more likely a pseudo atomic section is in a foreign
659 * call then an interrupt is executed immediately. Maybe it
660 * has to do with C code not maintaining pseudo atomic
661 * properly. MG - 2005-08-10 */
662 (!foreign_function_call_active) &&
664 arch_pseudo_atomic_atomic(context)) {
665 store_signal_data_for_later(data,handler,signal,info,context);
666 arch_set_pseudo_atomic_interrupted(context);
667 FSHOW_SIGNAL((stderr,
668 "/maybe_defer_handler(%x,%d),thread=%lu: deferred(PA)\n",
669 (unsigned int)handler,signal,
670 (unsigned long)thread->os_thread));
673 FSHOW_SIGNAL((stderr,
674 "/maybe_defer_handler(%x,%d),thread=%lu: not deferred\n",
675 (unsigned int)handler,signal,
676 (unsigned long)thread->os_thread));
681 store_signal_data_for_later (struct interrupt_data *data, void *handler,
683 siginfo_t *info, os_context_t *context)
685 if (data->pending_handler)
686 lose("tried to overwrite pending interrupt handler %x with %x\n",
687 data->pending_handler, handler);
689 lose("tried to defer null interrupt handler\n");
690 data->pending_handler = handler;
691 data->pending_signal = signal;
693 memcpy(&(data->pending_info), info, sizeof(siginfo_t));
695 FSHOW_SIGNAL((stderr, "/store_signal_data_for_later: signal: %d\n", signal));
698 /* the signal mask in the context (from before we were
699 * interrupted) is copied to be restored when
700 * run_deferred_handler happens. Then the usually-blocked
701 * signals are added to the mask in the context so that we are
702 * running with blocked signals when the handler returns */
703 sigcopyset(&(data->pending_mask),os_context_sigmask_addr(context));
704 sigaddset_deferrable(os_context_sigmask_addr(context));
709 maybe_now_maybe_later(int signal, siginfo_t *info, void *void_context)
711 os_context_t *context = arch_os_get_context(&void_context);
713 struct thread *thread;
714 struct interrupt_data *data;
716 thread=arch_os_get_current_thread();
717 data=thread->interrupt_data;
719 #if defined(LISP_FEATURE_LINUX) || defined(RESTORE_FP_CONTROL_FROM_CONTEXT)
720 os_restore_fp_control(context);
723 if(maybe_defer_handler(interrupt_handle_now,data,signal,info,context))
725 interrupt_handle_now(signal, info, context);
726 #ifdef LISP_FEATURE_DARWIN
727 /* Work around G5 bug */
728 DARWIN_FIX_CONTEXT(context);
733 low_level_interrupt_handle_now(int signal, siginfo_t *info, void *void_context)
735 os_context_t *context = (os_context_t*)void_context;
737 #if defined(LISP_FEATURE_LINUX) || defined(RESTORE_FP_CONTROL_FROM_CONTEXT)
738 os_restore_fp_control(context);
741 check_blockables_blocked_or_lose();
742 check_interrupts_enabled_or_lose(context);
743 interrupt_low_level_handlers[signal](signal, info, void_context);
744 #ifdef LISP_FEATURE_DARWIN
745 /* Work around G5 bug */
746 DARWIN_FIX_CONTEXT(context);
751 low_level_maybe_now_maybe_later(int signal, siginfo_t *info, void *void_context)
753 os_context_t *context = arch_os_get_context(&void_context);
754 struct thread *thread;
755 struct interrupt_data *data;
757 thread=arch_os_get_current_thread();
758 data=thread->interrupt_data;
760 #if defined(LISP_FEATURE_LINUX) || defined(RESTORE_FP_CONTROL_FROM_CONTEXT)
761 os_restore_fp_control(context);
764 if(maybe_defer_handler(low_level_interrupt_handle_now,data,
765 signal,info,context))
767 low_level_interrupt_handle_now(signal, info, context);
768 #ifdef LISP_FEATURE_DARWIN
769 /* Work around G5 bug */
770 DARWIN_FIX_CONTEXT(context);
775 #ifdef LISP_FEATURE_SB_THREAD
778 sig_stop_for_gc_handler(int signal, siginfo_t *info, void *void_context)
780 os_context_t *context = arch_os_get_context(&void_context);
782 struct thread *thread=arch_os_get_current_thread();
785 if ((arch_pseudo_atomic_atomic(context) ||
786 SymbolValue(GC_INHIBIT,thread) != NIL)) {
787 SetSymbolValue(STOP_FOR_GC_PENDING,T,thread);
788 if (SymbolValue(GC_INHIBIT,thread) == NIL)
789 arch_set_pseudo_atomic_interrupted(context);
790 FSHOW_SIGNAL((stderr,"thread=%lu sig_stop_for_gc deferred\n",
793 /* need the context stored so it can have registers scavenged */
794 fake_foreign_function_call(context);
796 sigfillset(&ss); /* Block everything. */
797 thread_sigmask(SIG_BLOCK,&ss,0);
799 if(thread->state!=STATE_RUNNING) {
800 lose("sig_stop_for_gc_handler: wrong thread state: %ld\n",
801 fixnum_value(thread->state));
803 thread->state=STATE_SUSPENDED;
804 FSHOW_SIGNAL((stderr,"thread=%lu suspended\n",thread->os_thread));
806 #if defined(SIG_RESUME_FROM_GC)
807 sigemptyset(&ss); sigaddset(&ss,SIG_RESUME_FROM_GC);
809 sigemptyset(&ss); sigaddset(&ss,SIG_STOP_FOR_GC);
812 /* It is possible to get SIGCONT (and probably other
813 * non-blockable signals) here. */
814 #ifdef SIG_RESUME_FROM_GC
817 do { sigwait(&ss, &sigret); }
818 while (sigret != SIG_RESUME_FROM_GC);
821 while (sigwaitinfo(&ss,0) != SIG_STOP_FOR_GC);
824 FSHOW_SIGNAL((stderr,"thread=%lu resumed\n",thread->os_thread));
825 if(thread->state!=STATE_RUNNING) {
826 lose("sig_stop_for_gc_handler: wrong thread state on wakeup: %ld\n",
827 fixnum_value(thread->state));
830 undo_fake_foreign_function_call(context);
836 interrupt_handle_now_handler(int signal, siginfo_t *info, void *void_context)
838 os_context_t *context = arch_os_get_context(&void_context);
839 interrupt_handle_now(signal, info, context);
840 #ifdef LISP_FEATURE_DARWIN
841 DARWIN_FIX_CONTEXT(context);
846 * stuff to detect and handle hitting the GC trigger
849 #ifndef LISP_FEATURE_GENCGC
850 /* since GENCGC has its own way to record trigger */
852 gc_trigger_hit(int signal, siginfo_t *info, os_context_t *context)
854 if (current_auto_gc_trigger == NULL)
857 void *badaddr=arch_get_bad_addr(signal,info,context);
858 return (badaddr >= (void *)current_auto_gc_trigger &&
859 badaddr <((void *)current_dynamic_space + dynamic_space_size));
864 /* manipulate the signal context and stack such that when the handler
865 * returns, it will call function instead of whatever it was doing
869 #if (defined(LISP_FEATURE_X86) || defined(LISP_FEATURE_X86_64))
870 extern int *context_eflags_addr(os_context_t *context);
873 extern lispobj call_into_lisp(lispobj fun, lispobj *args, int nargs);
874 extern void post_signal_tramp(void);
875 extern void call_into_lisp_tramp(void);
877 arrange_return_to_lisp_function(os_context_t *context, lispobj function)
879 #if !(defined(LISP_FEATURE_X86) || defined(LISP_FEATURE_X86_64))
880 void * fun=native_pointer(function);
881 void *code = &(((struct simple_fun *) fun)->code);
884 /* Build a stack frame showing `interrupted' so that the
885 * user's backtrace makes (as much) sense (as usual) */
887 /* FIXME: what about restoring fp state? */
888 /* FIXME: what about restoring errno? */
889 #ifdef LISP_FEATURE_X86
890 /* Suppose the existence of some function that saved all
891 * registers, called call_into_lisp, then restored GP registers and
892 * returned. It would look something like this:
900 pushl {address of function to call}
901 call 0x8058db0 <call_into_lisp>
908 * What we do here is set up the stack that call_into_lisp would
909 * expect to see if it had been called by this code, and frob the
910 * signal context so that signal return goes directly to call_into_lisp,
911 * and when that function (and the lisp function it invoked) returns,
912 * it returns to the second half of this imaginary function which
913 * restores all registers and returns to C
915 * For this to work, the latter part of the imaginary function
916 * must obviously exist in reality. That would be post_signal_tramp
919 u32 *sp=(u32 *)*os_context_register_addr(context,reg_ESP);
921 #if defined(LISP_FEATURE_DARWIN)
922 u32 *register_save_area = (u32 *)os_validate(0, 0x40);
924 FSHOW_SIGNAL((stderr, "/arrange_return_to_lisp_function: preparing to go to function %x, sp: %x\n", function, sp));
925 FSHOW_SIGNAL((stderr, "/arrange_return_to_lisp_function: context: %x, &context %x\n", context, &context));
927 /* 1. os_validate (malloc/mmap) register_save_block
928 * 2. copy register state into register_save_block
929 * 3. put a pointer to register_save_block in a register in the context
930 * 4. set the context's EIP to point to a trampoline which:
931 * a. builds the fake stack frame from the block
933 * c. calls the function
936 *register_save_area = *os_context_pc_addr(context);
937 *(register_save_area + 1) = function;
938 *(register_save_area + 2) = *os_context_register_addr(context,reg_EDI);
939 *(register_save_area + 3) = *os_context_register_addr(context,reg_ESI);
940 *(register_save_area + 4) = *os_context_register_addr(context,reg_EDX);
941 *(register_save_area + 5) = *os_context_register_addr(context,reg_ECX);
942 *(register_save_area + 6) = *os_context_register_addr(context,reg_EBX);
943 *(register_save_area + 7) = *os_context_register_addr(context,reg_EAX);
944 *(register_save_area + 8) = *context_eflags_addr(context);
946 *os_context_pc_addr(context) = call_into_lisp_tramp;
947 *os_context_register_addr(context,reg_ECX) = register_save_area;
950 /* return address for call_into_lisp: */
951 *(sp-15) = (u32)post_signal_tramp;
952 *(sp-14) = function; /* args for call_into_lisp : function*/
953 *(sp-13) = 0; /* arg array */
954 *(sp-12) = 0; /* no. args */
955 /* this order matches that used in POPAD */
956 *(sp-11)=*os_context_register_addr(context,reg_EDI);
957 *(sp-10)=*os_context_register_addr(context,reg_ESI);
959 *(sp-9)=*os_context_register_addr(context,reg_ESP)-8;
960 /* POPAD ignores the value of ESP: */
962 *(sp-7)=*os_context_register_addr(context,reg_EBX);
964 *(sp-6)=*os_context_register_addr(context,reg_EDX);
965 *(sp-5)=*os_context_register_addr(context,reg_ECX);
966 *(sp-4)=*os_context_register_addr(context,reg_EAX);
967 *(sp-3)=*context_eflags_addr(context);
968 *(sp-2)=*os_context_register_addr(context,reg_EBP);
969 *(sp-1)=*os_context_pc_addr(context);
973 #elif defined(LISP_FEATURE_X86_64)
974 u64 *sp=(u64 *)*os_context_register_addr(context,reg_RSP);
976 /* return address for call_into_lisp: */
977 *(sp-18) = (u64)post_signal_tramp;
979 *(sp-17)=*os_context_register_addr(context,reg_R15);
980 *(sp-16)=*os_context_register_addr(context,reg_R14);
981 *(sp-15)=*os_context_register_addr(context,reg_R13);
982 *(sp-14)=*os_context_register_addr(context,reg_R12);
983 *(sp-13)=*os_context_register_addr(context,reg_R11);
984 *(sp-12)=*os_context_register_addr(context,reg_R10);
985 *(sp-11)=*os_context_register_addr(context,reg_R9);
986 *(sp-10)=*os_context_register_addr(context,reg_R8);
987 *(sp-9)=*os_context_register_addr(context,reg_RDI);
988 *(sp-8)=*os_context_register_addr(context,reg_RSI);
989 /* skip RBP and RSP */
990 *(sp-7)=*os_context_register_addr(context,reg_RBX);
991 *(sp-6)=*os_context_register_addr(context,reg_RDX);
992 *(sp-5)=*os_context_register_addr(context,reg_RCX);
993 *(sp-4)=*os_context_register_addr(context,reg_RAX);
994 *(sp-3)=*context_eflags_addr(context);
995 *(sp-2)=*os_context_register_addr(context,reg_RBP);
996 *(sp-1)=*os_context_pc_addr(context);
998 *os_context_register_addr(context,reg_RDI) =
999 (os_context_register_t)function; /* function */
1000 *os_context_register_addr(context,reg_RSI) = 0; /* arg. array */
1001 *os_context_register_addr(context,reg_RDX) = 0; /* no. args */
1003 struct thread *th=arch_os_get_current_thread();
1004 build_fake_control_stack_frames(th,context);
1007 #ifdef LISP_FEATURE_X86
1009 #if !defined(LISP_FEATURE_DARWIN)
1010 *os_context_pc_addr(context) = (os_context_register_t)call_into_lisp;
1011 *os_context_register_addr(context,reg_ECX) = 0;
1012 *os_context_register_addr(context,reg_EBP) = (os_context_register_t)(sp-2);
1014 *os_context_register_addr(context,reg_UESP) =
1015 (os_context_register_t)(sp-15);
1017 *os_context_register_addr(context,reg_ESP) = (os_context_register_t)(sp-15);
1018 #endif /* __NETBSD__ */
1019 #endif /* LISP_FEATURE_DARWIN */
1021 #elif defined(LISP_FEATURE_X86_64)
1022 *os_context_pc_addr(context) = (os_context_register_t)call_into_lisp;
1023 *os_context_register_addr(context,reg_RCX) = 0;
1024 *os_context_register_addr(context,reg_RBP) = (os_context_register_t)(sp-2);
1025 *os_context_register_addr(context,reg_RSP) = (os_context_register_t)(sp-18);
1027 /* this much of the calling convention is common to all
1029 *os_context_pc_addr(context) = (os_context_register_t)(unsigned long)code;
1030 *os_context_register_addr(context,reg_NARGS) = 0;
1031 *os_context_register_addr(context,reg_LIP) =
1032 (os_context_register_t)(unsigned long)code;
1033 *os_context_register_addr(context,reg_CFP) =
1034 (os_context_register_t)(unsigned long)current_control_frame_pointer;
1036 #ifdef ARCH_HAS_NPC_REGISTER
1037 *os_context_npc_addr(context) =
1038 4 + *os_context_pc_addr(context);
1040 #ifdef LISP_FEATURE_SPARC
1041 *os_context_register_addr(context,reg_CODE) =
1042 (os_context_register_t)(fun + FUN_POINTER_LOWTAG);
1046 #ifdef LISP_FEATURE_SB_THREAD
1048 /* FIXME: this function can go away when all lisp handlers are invoked
1049 * via arrange_return_to_lisp_function. */
1051 interrupt_thread_handler(int num, siginfo_t *info, void *v_context)
1053 os_context_t *context = (os_context_t*)arch_os_get_context(&v_context);
1055 /* let the handler enable interrupts again when it sees fit */
1056 sigaddset_deferrable(os_context_sigmask_addr(context));
1057 arrange_return_to_lisp_function(context, SymbolFunction(RUN_INTERRUPTION));
1062 /* KLUDGE: Theoretically the approach we use for undefined alien
1063 * variables should work for functions as well, but on PPC/Darwin
1064 * we get bus error at bogus addresses instead, hence this workaround,
1065 * that has the added benefit of automatically discriminating between
1066 * functions and variables.
1069 undefined_alien_function() {
1070 funcall0(SymbolFunction(UNDEFINED_ALIEN_FUNCTION_ERROR));
1074 handle_guard_page_triggered(os_context_t *context,os_vm_address_t addr)
1076 struct thread *th=arch_os_get_current_thread();
1078 /* note the os_context hackery here. When the signal handler returns,
1079 * it won't go back to what it was doing ... */
1080 if(addr >= CONTROL_STACK_GUARD_PAGE(th) &&
1081 addr < CONTROL_STACK_GUARD_PAGE(th) + os_vm_page_size) {
1082 /* We hit the end of the control stack: disable guard page
1083 * protection so the error handler has some headroom, protect the
1084 * previous page so that we can catch returns from the guard page
1085 * and restore it. */
1086 protect_control_stack_guard_page(0);
1087 protect_control_stack_return_guard_page(1);
1089 arrange_return_to_lisp_function
1090 (context, SymbolFunction(CONTROL_STACK_EXHAUSTED_ERROR));
1093 else if(addr >= CONTROL_STACK_RETURN_GUARD_PAGE(th) &&
1094 addr < CONTROL_STACK_RETURN_GUARD_PAGE(th) + os_vm_page_size) {
1095 /* We're returning from the guard page: reprotect it, and
1096 * unprotect this one. This works even if we somehow missed
1097 * the return-guard-page, and hit it on our way to new
1098 * exhaustion instead. */
1099 protect_control_stack_guard_page(1);
1100 protect_control_stack_return_guard_page(0);
1103 else if (addr >= undefined_alien_address &&
1104 addr < undefined_alien_address + os_vm_page_size) {
1105 arrange_return_to_lisp_function
1106 (context, SymbolFunction(UNDEFINED_ALIEN_VARIABLE_ERROR));
1112 #ifndef LISP_FEATURE_GENCGC
1113 /* This function gets called from the SIGSEGV (for e.g. Linux, NetBSD, &
1114 * OpenBSD) or SIGBUS (for e.g. FreeBSD) handler. Here we check
1115 * whether the signal was due to treading on the mprotect()ed zone -
1116 * and if so, arrange for a GC to happen. */
1117 extern unsigned long bytes_consed_between_gcs; /* gc-common.c */
1120 interrupt_maybe_gc(int signal, siginfo_t *info, void *void_context)
1122 os_context_t *context=(os_context_t *) void_context;
1124 if(!foreign_function_call_active && gc_trigger_hit(signal, info, context)){
1125 struct thread *thread=arch_os_get_current_thread();
1126 clear_auto_gc_trigger();
1127 /* Don't flood the system with interrupts if the need to gc is
1128 * already noted. This can happen for example when SUB-GC
1129 * allocates or after a gc triggered in a WITHOUT-GCING. */
1130 if (SymbolValue(GC_PENDING,thread) == NIL) {
1131 if (SymbolValue(GC_INHIBIT,thread) == NIL) {
1132 if (arch_pseudo_atomic_atomic(context)) {
1133 /* set things up so that GC happens when we finish
1135 SetSymbolValue(GC_PENDING,T,thread);
1136 arch_set_pseudo_atomic_interrupted(context);
1138 interrupt_maybe_gc_int(signal,info,void_context);
1141 SetSymbolValue(GC_PENDING,T,thread);
1151 /* this is also used by gencgc, in alloc() */
1153 interrupt_maybe_gc_int(int signal, siginfo_t *info, void *void_context)
1155 os_context_t *context=(os_context_t *) void_context;
1156 #ifndef LISP_FEATURE_WIN32
1157 struct thread *thread=arch_os_get_current_thread();
1160 fake_foreign_function_call(context);
1162 /* SUB-GC may return without GCing if *GC-INHIBIT* is set, in
1163 * which case we will be running with no gc trigger barrier
1164 * thing for a while. But it shouldn't be long until the end
1167 * FIXME: It would be good to protect the end of dynamic space
1168 * and signal a storage condition from there.
1171 /* Restore the signal mask from the interrupted context before
1172 * calling into Lisp if interrupts are enabled. Why not always?
1174 * Suppose there is a WITHOUT-INTERRUPTS block far, far out. If an
1175 * interrupt hits while in SUB-GC, it is deferred and the
1176 * os_context_sigmask of that interrupt is set to block further
1177 * deferrable interrupts (until the first one is
1178 * handled). Unfortunately, that context refers to this place and
1179 * when we return from here the signals will not be blocked.
1181 * A kludgy alternative is to propagate the sigmask change to the
1184 #ifndef LISP_FEATURE_WIN32
1185 if(SymbolValue(INTERRUPTS_ENABLED,thread)!=NIL) {
1186 thread_sigmask(SIG_SETMASK, os_context_sigmask_addr(context), 0);
1187 check_gc_signals_unblocked_or_lose();
1190 unblock_gc_signals();
1192 funcall0(SymbolFunction(SUB_GC));
1193 undo_fake_foreign_function_call(context);
1199 * noise to install handlers
1202 #ifndef LISP_FEATURE_WIN32
1203 /* In Linux 2.4 synchronous signals (sigtrap & co) can be delivered if
1204 * they are blocked, in Linux 2.6 the default handler is invoked
1205 * instead that usually coredumps. One might hastily think that adding
1206 * SA_NODEFER helps, but until ~2.6.13 if SA_NODEFER is specified then
1207 * the whole sa_mask is ignored and instead of not adding the signal
1208 * in question to the mask. That means if it's not blockable the
1209 * signal must be unblocked at the beginning of signal handlers.
1211 * It turns out that NetBSD's SA_NODEFER doesn't DTRT in a different
1212 * way: if SA_NODEFER is set and the signal is in sa_mask, the signal
1213 * will be unblocked in the sigmask during the signal handler. -- RMK
1216 static volatile int sigaction_nodefer_works = -1;
1218 #define SA_NODEFER_TEST_BLOCK_SIGNAL SIGABRT
1219 #define SA_NODEFER_TEST_KILL_SIGNAL SIGUSR1
1222 sigaction_nodefer_test_handler(int signal, siginfo_t *info, void *void_context)
1224 sigset_t empty, current;
1226 sigemptyset(&empty);
1227 thread_sigmask(SIG_BLOCK, &empty, ¤t);
1228 /* There should be exactly two blocked signals: the two we added
1229 * to sa_mask when setting up the handler. NetBSD doesn't block
1230 * the signal we're handling when SA_NODEFER is set; Linux before
1231 * 2.6.13 or so also doesn't block the other signal when
1232 * SA_NODEFER is set. */
1233 for(i = 1; i < NSIG; i++)
1234 if (sigismember(¤t, i) !=
1235 (((i == SA_NODEFER_TEST_BLOCK_SIGNAL) || (i == signal)) ? 1 : 0)) {
1236 FSHOW_SIGNAL((stderr, "SA_NODEFER doesn't work, signal %d\n", i));
1237 sigaction_nodefer_works = 0;
1239 if (sigaction_nodefer_works == -1)
1240 sigaction_nodefer_works = 1;
1244 see_if_sigaction_nodefer_works()
1246 struct sigaction sa, old_sa;
1248 sa.sa_flags = SA_SIGINFO | SA_NODEFER;
1249 sa.sa_sigaction = sigaction_nodefer_test_handler;
1250 sigemptyset(&sa.sa_mask);
1251 sigaddset(&sa.sa_mask, SA_NODEFER_TEST_BLOCK_SIGNAL);
1252 sigaddset(&sa.sa_mask, SA_NODEFER_TEST_KILL_SIGNAL);
1253 sigaction(SA_NODEFER_TEST_KILL_SIGNAL, &sa, &old_sa);
1254 /* Make sure no signals are blocked. */
1257 sigemptyset(&empty);
1258 thread_sigmask(SIG_SETMASK, &empty, 0);
1260 kill(getpid(), SA_NODEFER_TEST_KILL_SIGNAL);
1261 while (sigaction_nodefer_works == -1);
1262 sigaction(SA_NODEFER_TEST_KILL_SIGNAL, &old_sa, NULL);
1265 #undef SA_NODEFER_TEST_BLOCK_SIGNAL
1266 #undef SA_NODEFER_TEST_KILL_SIGNAL
1269 unblock_me_trampoline(int signal, siginfo_t *info, void *void_context)
1273 sigemptyset(&unblock);
1274 sigaddset(&unblock, signal);
1275 thread_sigmask(SIG_UNBLOCK, &unblock, 0);
1276 interrupt_handle_now_handler(signal, info, void_context);
1280 low_level_unblock_me_trampoline(int signal, siginfo_t *info, void *void_context)
1284 sigemptyset(&unblock);
1285 sigaddset(&unblock, signal);
1286 thread_sigmask(SIG_UNBLOCK, &unblock, 0);
1287 (*interrupt_low_level_handlers[signal])(signal, info, void_context);
1291 undoably_install_low_level_interrupt_handler (int signal,
1296 struct sigaction sa;
1298 if (0 > signal || signal >= NSIG) {
1299 lose("bad signal number %d\n", signal);
1302 if (ARE_SAME_HANDLER(handler, SIG_DFL))
1303 sa.sa_sigaction = handler;
1304 else if (sigismember(&deferrable_sigset,signal))
1305 sa.sa_sigaction = low_level_maybe_now_maybe_later;
1306 /* The use of a trampoline appears to break the
1307 arch_os_get_context() workaround for SPARC/Linux. For now,
1308 don't use the trampoline (and so be vulnerable to the problems
1309 that SA_NODEFER is meant to solve. */
1310 #if !(defined(LISP_FEATURE_SPARC) && defined(LISP_FEATURE_LINUX))
1311 else if (!sigaction_nodefer_works &&
1312 !sigismember(&blockable_sigset, signal))
1313 sa.sa_sigaction = low_level_unblock_me_trampoline;
1316 sa.sa_sigaction = handler;
1318 sigcopyset(&sa.sa_mask, &blockable_sigset);
1319 sa.sa_flags = SA_SIGINFO | SA_RESTART
1320 | (sigaction_nodefer_works ? SA_NODEFER : 0);
1321 #ifdef LISP_FEATURE_C_STACK_IS_CONTROL_STACK
1322 if((signal==SIG_MEMORY_FAULT)
1323 #ifdef SIG_MEMORY_FAULT2
1324 || (signal==SIG_MEMORY_FAULT2)
1326 #ifdef SIG_INTERRUPT_THREAD
1327 || (signal==SIG_INTERRUPT_THREAD)
1330 sa.sa_flags |= SA_ONSTACK;
1333 sigaction(signal, &sa, NULL);
1334 interrupt_low_level_handlers[signal] =
1335 (ARE_SAME_HANDLER(handler, SIG_DFL) ? 0 : handler);
1339 /* This is called from Lisp. */
1341 install_handler(int signal, void handler(int, siginfo_t*, void*))
1343 #ifndef LISP_FEATURE_WIN32
1344 struct sigaction sa;
1346 union interrupt_handler oldhandler;
1348 FSHOW((stderr, "/entering POSIX install_handler(%d, ..)\n", signal));
1351 sigaddset(&new, signal);
1352 thread_sigmask(SIG_BLOCK, &new, &old);
1354 FSHOW((stderr, "/interrupt_low_level_handlers[signal]=%x\n",
1355 (unsigned int)interrupt_low_level_handlers[signal]));
1356 if (interrupt_low_level_handlers[signal]==0) {
1357 if (ARE_SAME_HANDLER(handler, SIG_DFL) ||
1358 ARE_SAME_HANDLER(handler, SIG_IGN))
1359 sa.sa_sigaction = handler;
1360 else if (sigismember(&deferrable_sigset, signal))
1361 sa.sa_sigaction = maybe_now_maybe_later;
1362 else if (!sigaction_nodefer_works &&
1363 !sigismember(&blockable_sigset, signal))
1364 sa.sa_sigaction = unblock_me_trampoline;
1366 sa.sa_sigaction = interrupt_handle_now_handler;
1368 sigcopyset(&sa.sa_mask, &blockable_sigset);
1369 sa.sa_flags = SA_SIGINFO | SA_RESTART |
1370 (sigaction_nodefer_works ? SA_NODEFER : 0);
1371 sigaction(signal, &sa, NULL);
1374 oldhandler = interrupt_handlers[signal];
1375 interrupt_handlers[signal].c = handler;
1377 thread_sigmask(SIG_SETMASK, &old, 0);
1379 FSHOW((stderr, "/leaving POSIX install_handler(%d, ..)\n", signal));
1381 return (unsigned long)oldhandler.lisp;
1383 /* Probably-wrong Win32 hack */
1391 #ifndef LISP_FEATURE_WIN32
1393 SHOW("entering interrupt_init()");
1394 see_if_sigaction_nodefer_works();
1395 sigemptyset(&deferrable_sigset);
1396 sigemptyset(&blockable_sigset);
1397 sigaddset_deferrable(&deferrable_sigset);
1398 sigaddset_blockable(&blockable_sigset);
1400 /* Set up high level handler information. */
1401 for (i = 0; i < NSIG; i++) {
1402 interrupt_handlers[i].c =
1403 /* (The cast here blasts away the distinction between
1404 * SA_SIGACTION-style three-argument handlers and
1405 * signal(..)-style one-argument handlers, which is OK
1406 * because it works to call the 1-argument form where the
1407 * 3-argument form is expected.) */
1408 (void (*)(int, siginfo_t*, void*))SIG_DFL;
1411 SHOW("returning from interrupt_init()");
1415 #ifndef LISP_FEATURE_WIN32
1417 siginfo_code(siginfo_t *info)
1419 return info->si_code;
1421 os_vm_address_t current_memory_fault_address;
1424 lisp_memory_fault_error(os_context_t *context, os_vm_address_t addr)
1426 /* FIXME: This is lossy: if we get another memory fault (eg. from
1427 * another thread) before lisp has read this, we the information.
1428 * However, since this is mostly informative, we'll live with that for
1429 * now -- some address is better then no address in this case.
1431 current_memory_fault_address = addr;
1432 arrange_return_to_lisp_function(context, SymbolFunction(MEMORY_FAULT_ERROR));