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 sigaddset_gc(sigset);
121 sigaddset_gc(sigset_t *sigset)
123 #ifdef LISP_FEATURE_SB_THREAD
124 sigaddset(sigset,SIG_STOP_FOR_GC);
128 /* initialized in interrupt_init */
129 sigset_t deferrable_sigset;
130 sigset_t blockable_sigset;
135 check_deferrables_unblocked_in_sigset_or_lose(sigset_t *sigset)
137 #if !defined(LISP_FEATURE_WIN32)
139 for(i = 1; i < NSIG; i++) {
140 if (sigismember(&deferrable_sigset, i) && sigismember(sigset, i))
141 lose("deferrable signal %d blocked\n",i);
147 check_deferrables_blocked_in_sigset_or_lose(sigset_t *sigset)
149 #if !defined(LISP_FEATURE_WIN32)
151 for(i = 1; i < NSIG; i++) {
152 if (sigismember(&deferrable_sigset, i) && !sigismember(sigset, i))
153 lose("deferrable signal %d not blocked\n",i);
159 check_deferrables_blocked_or_lose(void)
161 #if !defined(LISP_FEATURE_WIN32)
163 fill_current_sigmask(¤t);
164 check_deferrables_blocked_in_sigset_or_lose(¤t);
169 check_blockables_blocked_or_lose(void)
171 #if !defined(LISP_FEATURE_WIN32)
174 fill_current_sigmask(¤t);
175 for(i = 1; i < NSIG; i++) {
176 if (sigismember(&blockable_sigset, i) && !sigismember(¤t, i))
177 lose("blockable signal %d not blocked\n",i);
183 check_gc_signals_unblocked_in_sigset_or_lose(sigset_t *sigset)
185 #if !defined(LISP_FEATURE_WIN32)
187 for(i = 1; i < NSIG; i++) {
188 if (sigismember(&gc_sigset, i) && sigismember(sigset, i))
189 lose("gc signal %d blocked\n",i);
195 check_gc_signals_unblocked_or_lose(void)
197 #if !defined(LISP_FEATURE_WIN32)
199 fill_current_sigmask(¤t);
200 check_gc_signals_unblocked_in_sigset_or_lose(¤t);
205 check_interrupts_enabled_or_lose(os_context_t *context)
207 struct thread *thread=arch_os_get_current_thread();
208 if (SymbolValue(INTERRUPTS_ENABLED,thread) == NIL)
209 lose("interrupts not enabled\n");
210 if (arch_pseudo_atomic_atomic(context))
211 lose ("in pseudo atomic section\n");
214 /* Are we leaving WITH-GCING and already running with interrupts
215 * enabled, without the protection of *GC-INHIBIT* T and there is gc
216 * (or stop for gc) pending, but we haven't trapped yet? */
218 in_leaving_without_gcing_race_p(struct thread *thread)
220 return ((SymbolValue(IN_WITHOUT_GCING,thread) != NIL) &&
221 (SymbolValue(INTERRUPTS_ENABLED,thread) != NIL) &&
222 (SymbolValue(GC_INHIBIT,thread) == NIL) &&
223 ((SymbolValue(GC_PENDING,thread) != NIL)
224 #if defined(LISP_FEATURE_SB_THREAD)
225 || (SymbolValue(STOP_FOR_GC_PENDING,thread) != NIL)
230 /* Check our baroque invariants. */
232 check_interrupt_context_or_lose(os_context_t *context)
234 struct thread *thread = arch_os_get_current_thread();
235 struct interrupt_data *data = thread->interrupt_data;
236 int interrupt_deferred_p = (data->pending_handler != 0);
237 int interrupt_pending = (SymbolValue(INTERRUPT_PENDING,thread) != NIL);
238 /* On PPC pseudo_atomic_interrupted is cleared when coming out of
239 * handle_allocation_trap. */
240 #if defined(LISP_FEATURE_GENCGC) && !defined(LISP_FEATURE_PPC)
242 int interrupts_enabled = (SymbolValue(INTERRUPTS_ENABLED,thread) != NIL);
243 int gc_inhibit = (SymbolValue(GC_INHIBIT,thread) != NIL);
244 int gc_pending = (SymbolValue(GC_PENDING,thread) == T);
245 int pseudo_atomic_interrupted = get_pseudo_atomic_interrupted(thread);
246 int in_race_p = in_leaving_without_gcing_race_p(thread);
248 /* In the time window between leaving the *INTERRUPTS-ENABLED* NIL
249 * section and trapping, a SIG_STOP_FOR_GC would see the next
250 * check fail, for this reason sig_stop_for_gc handler does not
251 * call this function. Plus, there may be interrupt lossage when a
252 * pseudo atomic is interrupted by a deferrable signal and gc is
255 if (interrupt_deferred_p)
256 if (!(!interrupts_enabled || pseudo_atomic_interrupted || in_race_p))
257 lose("Stray deferred interrupt.");
261 if (!(pseudo_atomic_interrupted || gc_inhibit || in_race_p))
262 lose("GC_PENDING, but why?.");
263 #if defined(LISP_FEATURE_SB_THREAD)
265 int stop_for_gc_pending =
266 (SymbolValue(STOP_FOR_GC_PENDING,thread) != NIL);
267 if (stop_for_gc_pending)
268 if (!(pseudo_atomic_interrupted || gc_inhibit || in_race_p))
269 lose("STOP_FOR_GC_PENDING, but why?.");
274 if (interrupt_pending && !interrupt_deferred_p)
275 lose("INTERRUPT_PENDING but not pending handler.");
276 if (interrupt_deferred_p)
277 check_deferrables_blocked_in_sigset_or_lose
278 (os_context_sigmask_addr(context));
280 check_deferrables_unblocked_in_sigset_or_lose
281 (os_context_sigmask_addr(context));
284 /* When we catch an internal error, should we pass it back to Lisp to
285 * be handled in a high-level way? (Early in cold init, the answer is
286 * 'no', because Lisp is still too brain-dead to handle anything.
287 * After sufficient initialization has been completed, the answer
289 boolean internal_errors_enabled = 0;
291 #ifndef LISP_FEATURE_WIN32
292 static void (*interrupt_low_level_handlers[NSIG]) (int, siginfo_t*, void*);
294 union interrupt_handler interrupt_handlers[NSIG];
297 block_blockable_signals(void)
299 #ifndef LISP_FEATURE_WIN32
300 thread_sigmask(SIG_BLOCK, &blockable_sigset, 0);
305 block_deferrable_signals(void)
307 #ifndef LISP_FEATURE_WIN32
308 thread_sigmask(SIG_BLOCK, &deferrable_sigset, 0);
313 unblock_deferrable_signals(void)
315 #ifndef LISP_FEATURE_WIN32
316 thread_sigmask(SIG_UNBLOCK, &deferrable_sigset, 0);
321 unblock_gc_signals(void)
323 #if defined(LISP_FEATURE_SB_THREAD) && !defined(LISP_FEATURE_WIN32)
324 thread_sigmask(SIG_UNBLOCK,&gc_sigset,0);
330 * utility routines used by various signal handlers
334 build_fake_control_stack_frames(struct thread *th,os_context_t *context)
336 #ifndef LISP_FEATURE_C_STACK_IS_CONTROL_STACK
340 /* Build a fake stack frame or frames */
342 current_control_frame_pointer =
343 (lispobj *)(unsigned long)
344 (*os_context_register_addr(context, reg_CSP));
345 if ((lispobj *)(unsigned long)
346 (*os_context_register_addr(context, reg_CFP))
347 == current_control_frame_pointer) {
348 /* There is a small window during call where the callee's
349 * frame isn't built yet. */
350 if (lowtag_of(*os_context_register_addr(context, reg_CODE))
351 == FUN_POINTER_LOWTAG) {
352 /* We have called, but not built the new frame, so
353 * build it for them. */
354 current_control_frame_pointer[0] =
355 *os_context_register_addr(context, reg_OCFP);
356 current_control_frame_pointer[1] =
357 *os_context_register_addr(context, reg_LRA);
358 current_control_frame_pointer += 8;
359 /* Build our frame on top of it. */
360 oldcont = (lispobj)(*os_context_register_addr(context, reg_CFP));
363 /* We haven't yet called, build our frame as if the
364 * partial frame wasn't there. */
365 oldcont = (lispobj)(*os_context_register_addr(context, reg_OCFP));
368 /* We can't tell whether we are still in the caller if it had to
369 * allocate a stack frame due to stack arguments. */
370 /* This observation provoked some past CMUCL maintainer to ask
371 * "Can anything strange happen during return?" */
374 oldcont = (lispobj)(*os_context_register_addr(context, reg_CFP));
377 current_control_stack_pointer = current_control_frame_pointer + 8;
379 current_control_frame_pointer[0] = oldcont;
380 current_control_frame_pointer[1] = NIL;
381 current_control_frame_pointer[2] =
382 (lispobj)(*os_context_register_addr(context, reg_CODE));
386 /* Stores the context for gc to scavange and builds fake stack
389 fake_foreign_function_call(os_context_t *context)
392 struct thread *thread=arch_os_get_current_thread();
394 /* context_index incrementing must not be interrupted */
395 check_blockables_blocked_or_lose();
397 /* Get current Lisp state from context. */
399 dynamic_space_free_pointer =
400 (lispobj *)(unsigned long)
401 (*os_context_register_addr(context, reg_ALLOC));
402 /* fprintf(stderr,"dynamic_space_free_pointer: %p\n", */
403 /* dynamic_space_free_pointer); */
404 #if defined(LISP_FEATURE_ALPHA) || defined(LISP_FEATURE_MIPS)
405 if ((long)dynamic_space_free_pointer & 1) {
406 lose("dead in fake_foreign_function_call, context = %x\n", context);
409 /* why doesnt PPC and SPARC do something like this: */
410 #if defined(LISP_FEATURE_HPPA)
411 if ((long)dynamic_space_free_pointer & 4) {
412 lose("dead in fake_foreign_function_call, context = %x, d_s_f_p = %x\n", context, dynamic_space_free_pointer);
417 current_binding_stack_pointer =
418 (lispobj *)(unsigned long)
419 (*os_context_register_addr(context, reg_BSP));
422 build_fake_control_stack_frames(thread,context);
424 /* Do dynamic binding of the active interrupt context index
425 * and save the context in the context array. */
427 fixnum_value(SymbolValue(FREE_INTERRUPT_CONTEXT_INDEX,thread));
429 if (context_index >= MAX_INTERRUPTS) {
430 lose("maximum interrupt nesting depth (%d) exceeded\n", MAX_INTERRUPTS);
433 bind_variable(FREE_INTERRUPT_CONTEXT_INDEX,
434 make_fixnum(context_index + 1),thread);
436 thread->interrupt_contexts[context_index] = context;
438 #ifdef FOREIGN_FUNCTION_CALL_FLAG
439 foreign_function_call_active = 1;
443 /* blocks all blockable signals. If you are calling from a signal handler,
444 * the usual signal mask will be restored from the context when the handler
445 * finishes. Otherwise, be careful */
447 undo_fake_foreign_function_call(os_context_t *context)
449 struct thread *thread=arch_os_get_current_thread();
450 /* Block all blockable signals. */
451 block_blockable_signals();
453 #ifdef FOREIGN_FUNCTION_CALL_FLAG
454 foreign_function_call_active = 0;
457 /* Undo dynamic binding of FREE_INTERRUPT_CONTEXT_INDEX */
461 /* Put the dynamic space free pointer back into the context. */
462 *os_context_register_addr(context, reg_ALLOC) =
463 (unsigned long) dynamic_space_free_pointer
464 | (*os_context_register_addr(context, reg_ALLOC)
467 ((unsigned long)(*os_context_register_addr(context, reg_ALLOC))
469 | ((unsigned long) dynamic_space_free_pointer & LOWTAG_MASK);
474 /* a handler for the signal caused by execution of a trap opcode
475 * signalling an internal error */
477 interrupt_internal_error(os_context_t *context, boolean continuable)
481 fake_foreign_function_call(context);
483 if (!internal_errors_enabled) {
484 describe_internal_error(context);
485 /* There's no good way to recover from an internal error
486 * before the Lisp error handling mechanism is set up. */
487 lose("internal error too early in init, can't recover\n");
490 /* Allocate the SAP object while the interrupts are still
492 context_sap = alloc_sap(context);
494 #ifndef LISP_FEATURE_WIN32
495 thread_sigmask(SIG_SETMASK, os_context_sigmask_addr(context), 0);
498 #if defined(LISP_FEATURE_LINUX) && defined(LISP_FEATURE_MIPS)
499 /* Workaround for blocked SIGTRAP. */
502 sigemptyset(&newset);
503 sigaddset(&newset, SIGTRAP);
504 thread_sigmask(SIG_UNBLOCK, &newset, 0);
508 SHOW("in interrupt_internal_error");
510 /* Display some rudimentary debugging information about the
511 * error, so that even if the Lisp error handler gets badly
512 * confused, we have a chance to determine what's going on. */
513 describe_internal_error(context);
515 funcall2(StaticSymbolFunction(INTERNAL_ERROR), context_sap,
516 continuable ? T : NIL);
518 undo_fake_foreign_function_call(context); /* blocks signals again */
520 arch_skip_instruction(context);
524 interrupt_handler_pending_p(void)
526 struct thread *thread = arch_os_get_current_thread();
527 struct interrupt_data *data = thread->interrupt_data;
528 return (data->pending_handler != 0);
532 interrupt_handle_pending(os_context_t *context)
534 /* There are three ways we can get here. First, if an interrupt
535 * occurs within pseudo-atomic, it will be deferred, and we'll
536 * trap to here at the end of the pseudo-atomic block. Second, if
537 * the GC (in alloc()) decides that a GC is required, it will set
538 * *GC-PENDING* and pseudo-atomic-interrupted if not *GC-INHIBIT*,
539 * and alloc() is always called from within pseudo-atomic, and
540 * thus we end up here again. Third, when calling GC-ON or at the
541 * end of a WITHOUT-GCING, MAYBE-HANDLE-PENDING-GC will trap to
542 * here if there is a pending GC. Fourth, ahem, at the end of
543 * WITHOUT-INTERRUPTS (bar complications with nesting). */
545 /* Win32 only needs to handle the GC cases (for now?) */
547 struct thread *thread;
549 if (arch_pseudo_atomic_atomic(context)) {
550 lose("Handling pending interrupt in pseduo atomic.");
553 thread = arch_os_get_current_thread();
555 FSHOW_SIGNAL((stderr, "/entering interrupt_handle_pending\n"));
557 check_blockables_blocked_or_lose();
559 /* If pseudo_atomic_interrupted is set then the interrupt is going
560 * to be handled now, ergo it's safe to clear it. */
561 arch_clear_pseudo_atomic_interrupted(context);
563 if (SymbolValue(GC_INHIBIT,thread)==NIL) {
564 #ifdef LISP_FEATURE_SB_THREAD
565 if (SymbolValue(STOP_FOR_GC_PENDING,thread) != NIL) {
566 /* STOP_FOR_GC_PENDING and GC_PENDING are cleared by
567 * the signal handler if it actually stops us. */
568 sig_stop_for_gc_handler(SIG_STOP_FOR_GC,NULL,context);
571 /* Test for T and not for != NIL since the value :IN-PROGRESS
572 * is used in SUB-GC as part of the mechanism to supress
574 if (SymbolValue(GC_PENDING,thread) == T) {
575 /* GC_PENDING is cleared in SUB-GC, or if another thread
576 * is doing a gc already we will get a SIG_STOP_FOR_GC and
577 * that will clear it. */
580 check_blockables_blocked_or_lose();
583 #ifndef LISP_FEATURE_WIN32
584 /* we may be here only to do the gc stuff, if interrupts are
585 * enabled run the pending handler */
586 if (SymbolValue(INTERRUPTS_ENABLED,thread) != NIL) {
587 struct interrupt_data *data = thread->interrupt_data;
589 /* There may be no pending handler, because it was only a gc
590 * that had to be executed or because pseudo atomic triggered
591 * twice for a single interrupt. For the interested reader,
592 * that may happen if an interrupt hits after the interrupted
593 * flag is cleared but before pseudo-atomic is set and a
594 * pseudo atomic is interrupted in that interrupt. */
595 if (data->pending_handler) {
597 /* If we're here as the result of a pseudo-atomic as opposed
598 * to WITHOUT-INTERRUPTS, then INTERRUPT_PENDING is already
599 * NIL, because maybe_defer_handler sets
600 * PSEUDO_ATOMIC_INTERRUPTED only if interrupts are enabled.*/
601 SetSymbolValue(INTERRUPT_PENDING, NIL, thread);
603 /* restore the saved signal mask from the original signal (the
604 * one that interrupted us during the critical section) into the
605 * os_context for the signal we're currently in the handler for.
606 * This should ensure that when we return from the handler the
607 * blocked signals are unblocked */
608 sigcopyset(os_context_sigmask_addr(context), &data->pending_mask);
610 /* This will break on sparc linux: the deferred handler really wants
611 * to be called with a void_context */
612 run_deferred_handler(data,(void *)context);
619 * the two main signal handlers:
620 * interrupt_handle_now(..)
621 * maybe_now_maybe_later(..)
623 * to which we have added interrupt_handle_now_handler(..). Why?
624 * Well, mostly because the SPARC/Linux platform doesn't quite do
625 * signals the way we want them done. The third argument in the
626 * handler isn't filled in by the kernel properly, so we fix it up
627 * ourselves in the arch_os_get_context(..) function; however, we only
628 * want to do this when we first hit the handler, and not when
629 * interrupt_handle_now(..) is being called from some other handler
630 * (when the fixup will already have been done). -- CSR, 2002-07-23
634 interrupt_handle_now(int signal, siginfo_t *info, os_context_t *context)
636 #ifdef FOREIGN_FUNCTION_CALL_FLAG
637 boolean were_in_lisp;
639 union interrupt_handler handler;
641 check_blockables_blocked_or_lose();
643 #ifndef LISP_FEATURE_WIN32
644 if (sigismember(&deferrable_sigset,signal))
645 check_interrupts_enabled_or_lose(context);
648 #if defined(LISP_FEATURE_LINUX) || defined(RESTORE_FP_CONTROL_FROM_CONTEXT)
649 /* Under Linux on some architectures, we appear to have to restore
650 the FPU control word from the context, as after the signal is
651 delivered we appear to have a null FPU control word. */
652 os_restore_fp_control(context);
655 handler = interrupt_handlers[signal];
657 if (ARE_SAME_HANDLER(handler.c, SIG_IGN)) {
661 #ifdef FOREIGN_FUNCTION_CALL_FLAG
662 were_in_lisp = !foreign_function_call_active;
666 fake_foreign_function_call(context);
669 FSHOW_SIGNAL((stderr,
670 "/entering interrupt_handle_now(%d, info, context)\n",
673 if (ARE_SAME_HANDLER(handler.c, SIG_DFL)) {
675 /* This can happen if someone tries to ignore or default one
676 * of the signals we need for runtime support, and the runtime
677 * support decides to pass on it. */
678 lose("no handler for signal %d in interrupt_handle_now(..)\n", signal);
680 } else if (lowtag_of(handler.lisp) == FUN_POINTER_LOWTAG) {
681 /* Once we've decided what to do about contexts in a
682 * return-elsewhere world (the original context will no longer
683 * be available; should we copy it or was nobody using it anyway?)
684 * then we should convert this to return-elsewhere */
686 /* CMUCL comment said "Allocate the SAPs while the interrupts
687 * are still disabled.". I (dan, 2003.08.21) assume this is
688 * because we're not in pseudoatomic and allocation shouldn't
689 * be interrupted. In which case it's no longer an issue as
690 * all our allocation from C now goes through a PA wrapper,
691 * but still, doesn't hurt.
693 * Yeah, but non-gencgc platforms don't really wrap allocation
694 * in PA. MG - 2005-08-29 */
696 lispobj info_sap,context_sap = alloc_sap(context);
697 info_sap = alloc_sap(info);
698 /* Leave deferrable signals blocked, the handler itself will
699 * allow signals again when it sees fit. */
700 #ifdef LISP_FEATURE_SB_THREAD
703 sigemptyset(&unblock);
704 sigaddset(&unblock, SIG_STOP_FOR_GC);
705 #ifdef SIG_RESUME_FROM_GC
706 sigaddset(&unblock, SIG_RESUME_FROM_GC);
708 thread_sigmask(SIG_UNBLOCK, &unblock, 0);
712 FSHOW_SIGNAL((stderr,"/calling Lisp-level handler\n"));
714 funcall3(handler.lisp,
720 FSHOW_SIGNAL((stderr,"/calling C-level handler\n"));
722 #ifndef LISP_FEATURE_WIN32
723 /* Allow signals again. */
724 thread_sigmask(SIG_SETMASK, os_context_sigmask_addr(context), 0);
726 (*handler.c)(signal, info, context);
729 #ifdef FOREIGN_FUNCTION_CALL_FLAG
733 undo_fake_foreign_function_call(context); /* block signals again */
736 FSHOW_SIGNAL((stderr,
737 "/returning from interrupt_handle_now(%d, info, context)\n",
741 /* This is called at the end of a critical section if the indications
742 * are that some signal was deferred during the section. Note that as
743 * far as C or the kernel is concerned we dealt with the signal
744 * already; we're just doing the Lisp-level processing now that we
747 run_deferred_handler(struct interrupt_data *data, void *v_context)
749 /* The pending_handler may enable interrupts and then another
750 * interrupt may hit, overwrite interrupt_data, so reset the
751 * pending handler before calling it. Trust the handler to finish
752 * with the siginfo before enabling interrupts. */
753 void (*pending_handler) (int, siginfo_t*, void*)=data->pending_handler;
755 data->pending_handler=0;
756 (*pending_handler)(data->pending_signal,&(data->pending_info), v_context);
759 #ifndef LISP_FEATURE_WIN32
761 maybe_defer_handler(void *handler, struct interrupt_data *data,
762 int signal, siginfo_t *info, os_context_t *context)
764 struct thread *thread=arch_os_get_current_thread();
766 check_blockables_blocked_or_lose();
768 if (SymbolValue(INTERRUPT_PENDING,thread) != NIL)
769 lose("interrupt already pending\n");
770 check_interrupt_context_or_lose(context);
771 /* If interrupts are disabled then INTERRUPT_PENDING is set and
772 * not PSEDUO_ATOMIC_INTERRUPTED. This is important for a pseudo
773 * atomic section inside a WITHOUT-INTERRUPTS.
775 * Also, if in_leaving_without_gcing_race_p then
776 * interrupt_handle_pending is going to be called soon, so
777 * stashing the signal away is safe.
779 if ((SymbolValue(INTERRUPTS_ENABLED,thread) == NIL) ||
780 in_leaving_without_gcing_race_p(thread)) {
781 store_signal_data_for_later(data,handler,signal,info,context);
782 SetSymbolValue(INTERRUPT_PENDING, T,thread);
783 FSHOW_SIGNAL((stderr,
784 "/maybe_defer_handler(%x,%d): deferred\n",
785 (unsigned int)handler,signal));
786 check_interrupt_context_or_lose(context);
789 /* a slightly confusing test. arch_pseudo_atomic_atomic() doesn't
790 * actually use its argument for anything on x86, so this branch
791 * may succeed even when context is null (gencgc alloc()) */
792 if (arch_pseudo_atomic_atomic(context)) {
793 store_signal_data_for_later(data,handler,signal,info,context);
794 arch_set_pseudo_atomic_interrupted(context);
795 FSHOW_SIGNAL((stderr,
796 "/maybe_defer_handler(%x,%d): deferred(PA)\n",
797 (unsigned int)handler,signal));
798 check_interrupt_context_or_lose(context);
801 FSHOW_SIGNAL((stderr,
802 "/maybe_defer_handler(%x,%d): not deferred\n",
803 (unsigned int)handler,signal));
808 store_signal_data_for_later (struct interrupt_data *data, void *handler,
810 siginfo_t *info, os_context_t *context)
812 if (data->pending_handler)
813 lose("tried to overwrite pending interrupt handler %x with %x\n",
814 data->pending_handler, handler);
816 lose("tried to defer null interrupt handler\n");
817 data->pending_handler = handler;
818 data->pending_signal = signal;
820 memcpy(&(data->pending_info), info, sizeof(siginfo_t));
822 FSHOW_SIGNAL((stderr, "/store_signal_data_for_later: signal: %d\n",
826 /* the signal mask in the context (from before we were
827 * interrupted) is copied to be restored when
828 * run_deferred_handler happens. Then the usually-blocked
829 * signals are added to the mask in the context so that we are
830 * running with blocked signals when the handler returns */
831 sigcopyset(&(data->pending_mask),os_context_sigmask_addr(context));
832 sigaddset_deferrable(os_context_sigmask_addr(context));
837 maybe_now_maybe_later(int signal, siginfo_t *info, void *void_context)
839 os_context_t *context = arch_os_get_context(&void_context);
840 struct thread *thread = arch_os_get_current_thread();
841 struct interrupt_data *data = thread->interrupt_data;
843 #if defined(LISP_FEATURE_LINUX) || defined(RESTORE_FP_CONTROL_FROM_CONTEXT)
844 os_restore_fp_control(context);
847 if(!maybe_defer_handler(interrupt_handle_now,data,signal,info,context))
848 interrupt_handle_now(signal, info, context);
852 low_level_interrupt_handle_now(int signal, siginfo_t *info,
853 os_context_t *context)
855 /* No FP control fixage needed, caller has done that. */
856 check_blockables_blocked_or_lose();
857 check_interrupts_enabled_or_lose(context);
858 (*interrupt_low_level_handlers[signal])(signal, info, context);
859 /* No Darwin context fixage needed, caller does that. */
863 low_level_maybe_now_maybe_later(int signal, siginfo_t *info, void *void_context)
865 os_context_t *context = arch_os_get_context(&void_context);
866 struct thread *thread = arch_os_get_current_thread();
867 struct interrupt_data *data = thread->interrupt_data;
869 #if defined(LISP_FEATURE_LINUX) || defined(RESTORE_FP_CONTROL_FROM_CONTEXT)
870 os_restore_fp_control(context);
873 if(!maybe_defer_handler(low_level_interrupt_handle_now,data,
874 signal,info,context))
875 low_level_interrupt_handle_now(signal, info, context);
879 #ifdef LISP_FEATURE_SB_THREAD
882 sig_stop_for_gc_handler(int signal, siginfo_t *info, void *void_context)
884 os_context_t *context = arch_os_get_context(&void_context);
886 struct thread *thread=arch_os_get_current_thread();
889 /* Test for GC_INHIBIT _first_, else we'd trap on every single
890 * pseudo atomic until gc is finally allowed. */
891 if (SymbolValue(GC_INHIBIT,thread) != NIL) {
892 SetSymbolValue(STOP_FOR_GC_PENDING,T,thread);
893 FSHOW_SIGNAL((stderr, "sig_stop_for_gc deferred (*GC-INHIBIT*)\n"));
895 } else if (arch_pseudo_atomic_atomic(context)) {
896 SetSymbolValue(STOP_FOR_GC_PENDING,T,thread);
897 arch_set_pseudo_atomic_interrupted(context);
898 FSHOW_SIGNAL((stderr,"sig_stop_for_gc deferred (PA)\n"));
902 /* Not PA and GC not inhibited -- we can stop now. */
904 /* need the context stored so it can have registers scavenged */
905 fake_foreign_function_call(context);
907 /* Block everything. */
909 thread_sigmask(SIG_BLOCK,&ss,0);
911 /* Not pending anymore. */
912 SetSymbolValue(GC_PENDING,NIL,thread);
913 SetSymbolValue(STOP_FOR_GC_PENDING,NIL,thread);
915 if(thread_state(thread)!=STATE_RUNNING) {
916 lose("sig_stop_for_gc_handler: wrong thread state: %ld\n",
917 fixnum_value(thread->state));
920 set_thread_state(thread,STATE_SUSPENDED);
921 FSHOW_SIGNAL((stderr,"suspended\n"));
923 wait_for_thread_state_change(thread, STATE_SUSPENDED);
924 FSHOW_SIGNAL((stderr,"resumed\n"));
926 if(thread_state(thread)!=STATE_RUNNING) {
927 lose("sig_stop_for_gc_handler: wrong thread state on wakeup: %ld\n",
928 fixnum_value(thread_state(thread)));
931 undo_fake_foreign_function_call(context);
937 interrupt_handle_now_handler(int signal, siginfo_t *info, void *void_context)
939 os_context_t *context = arch_os_get_context(&void_context);
940 #if defined(LISP_FEATURE_LINUX) || defined(RESTORE_FP_CONTROL_FROM_CONTEXT)
941 os_restore_fp_control(context);
942 #ifndef LISP_FEATURE_WIN32
943 if ((signal == SIGILL) || (signal == SIGBUS)
944 #ifndef LISP_FEATURE_LINUX
945 || (signal == SIGEMT)
948 corruption_warning_and_maybe_lose("Signal %d recieved", signal);
951 interrupt_handle_now(signal, info, context);
954 /* manipulate the signal context and stack such that when the handler
955 * returns, it will call function instead of whatever it was doing
959 #if (defined(LISP_FEATURE_X86) || defined(LISP_FEATURE_X86_64))
960 extern int *context_eflags_addr(os_context_t *context);
963 extern lispobj call_into_lisp(lispobj fun, lispobj *args, int nargs);
964 extern void post_signal_tramp(void);
965 extern void call_into_lisp_tramp(void);
967 arrange_return_to_lisp_function(os_context_t *context, lispobj function)
969 #if !(defined(LISP_FEATURE_X86) || defined(LISP_FEATURE_X86_64))
970 void * fun=native_pointer(function);
971 void *code = &(((struct simple_fun *) fun)->code);
974 /* Build a stack frame showing `interrupted' so that the
975 * user's backtrace makes (as much) sense (as usual) */
977 /* FIXME: what about restoring fp state? */
978 /* FIXME: what about restoring errno? */
979 #ifdef LISP_FEATURE_X86
980 /* Suppose the existence of some function that saved all
981 * registers, called call_into_lisp, then restored GP registers and
982 * returned. It would look something like this:
990 pushl {address of function to call}
991 call 0x8058db0 <call_into_lisp>
998 * What we do here is set up the stack that call_into_lisp would
999 * expect to see if it had been called by this code, and frob the
1000 * signal context so that signal return goes directly to call_into_lisp,
1001 * and when that function (and the lisp function it invoked) returns,
1002 * it returns to the second half of this imaginary function which
1003 * restores all registers and returns to C
1005 * For this to work, the latter part of the imaginary function
1006 * must obviously exist in reality. That would be post_signal_tramp
1009 u32 *sp=(u32 *)*os_context_register_addr(context,reg_ESP);
1011 #if defined(LISP_FEATURE_DARWIN)
1012 u32 *register_save_area = (u32 *)os_validate(0, 0x40);
1014 FSHOW_SIGNAL((stderr, "/arrange_return_to_lisp_function: preparing to go to function %x, sp: %x\n", function, sp));
1015 FSHOW_SIGNAL((stderr, "/arrange_return_to_lisp_function: context: %x, &context %x\n", context, &context));
1017 /* 1. os_validate (malloc/mmap) register_save_block
1018 * 2. copy register state into register_save_block
1019 * 3. put a pointer to register_save_block in a register in the context
1020 * 4. set the context's EIP to point to a trampoline which:
1021 * a. builds the fake stack frame from the block
1022 * b. frees the block
1023 * c. calls the function
1026 *register_save_area = *os_context_pc_addr(context);
1027 *(register_save_area + 1) = function;
1028 *(register_save_area + 2) = *os_context_register_addr(context,reg_EDI);
1029 *(register_save_area + 3) = *os_context_register_addr(context,reg_ESI);
1030 *(register_save_area + 4) = *os_context_register_addr(context,reg_EDX);
1031 *(register_save_area + 5) = *os_context_register_addr(context,reg_ECX);
1032 *(register_save_area + 6) = *os_context_register_addr(context,reg_EBX);
1033 *(register_save_area + 7) = *os_context_register_addr(context,reg_EAX);
1034 *(register_save_area + 8) = *context_eflags_addr(context);
1036 *os_context_pc_addr(context) =
1037 (os_context_register_t) call_into_lisp_tramp;
1038 *os_context_register_addr(context,reg_ECX) =
1039 (os_context_register_t) register_save_area;
1042 /* return address for call_into_lisp: */
1043 *(sp-15) = (u32)post_signal_tramp;
1044 *(sp-14) = function; /* args for call_into_lisp : function*/
1045 *(sp-13) = 0; /* arg array */
1046 *(sp-12) = 0; /* no. args */
1047 /* this order matches that used in POPAD */
1048 *(sp-11)=*os_context_register_addr(context,reg_EDI);
1049 *(sp-10)=*os_context_register_addr(context,reg_ESI);
1051 *(sp-9)=*os_context_register_addr(context,reg_ESP)-8;
1052 /* POPAD ignores the value of ESP: */
1054 *(sp-7)=*os_context_register_addr(context,reg_EBX);
1056 *(sp-6)=*os_context_register_addr(context,reg_EDX);
1057 *(sp-5)=*os_context_register_addr(context,reg_ECX);
1058 *(sp-4)=*os_context_register_addr(context,reg_EAX);
1059 *(sp-3)=*context_eflags_addr(context);
1060 *(sp-2)=*os_context_register_addr(context,reg_EBP);
1061 *(sp-1)=*os_context_pc_addr(context);
1065 #elif defined(LISP_FEATURE_X86_64)
1066 u64 *sp=(u64 *)*os_context_register_addr(context,reg_RSP);
1068 /* return address for call_into_lisp: */
1069 *(sp-18) = (u64)post_signal_tramp;
1071 *(sp-17)=*os_context_register_addr(context,reg_R15);
1072 *(sp-16)=*os_context_register_addr(context,reg_R14);
1073 *(sp-15)=*os_context_register_addr(context,reg_R13);
1074 *(sp-14)=*os_context_register_addr(context,reg_R12);
1075 *(sp-13)=*os_context_register_addr(context,reg_R11);
1076 *(sp-12)=*os_context_register_addr(context,reg_R10);
1077 *(sp-11)=*os_context_register_addr(context,reg_R9);
1078 *(sp-10)=*os_context_register_addr(context,reg_R8);
1079 *(sp-9)=*os_context_register_addr(context,reg_RDI);
1080 *(sp-8)=*os_context_register_addr(context,reg_RSI);
1081 /* skip RBP and RSP */
1082 *(sp-7)=*os_context_register_addr(context,reg_RBX);
1083 *(sp-6)=*os_context_register_addr(context,reg_RDX);
1084 *(sp-5)=*os_context_register_addr(context,reg_RCX);
1085 *(sp-4)=*os_context_register_addr(context,reg_RAX);
1086 *(sp-3)=*context_eflags_addr(context);
1087 *(sp-2)=*os_context_register_addr(context,reg_RBP);
1088 *(sp-1)=*os_context_pc_addr(context);
1090 *os_context_register_addr(context,reg_RDI) =
1091 (os_context_register_t)function; /* function */
1092 *os_context_register_addr(context,reg_RSI) = 0; /* arg. array */
1093 *os_context_register_addr(context,reg_RDX) = 0; /* no. args */
1095 struct thread *th=arch_os_get_current_thread();
1096 build_fake_control_stack_frames(th,context);
1099 #ifdef LISP_FEATURE_X86
1101 #if !defined(LISP_FEATURE_DARWIN)
1102 *os_context_pc_addr(context) = (os_context_register_t)call_into_lisp;
1103 *os_context_register_addr(context,reg_ECX) = 0;
1104 *os_context_register_addr(context,reg_EBP) = (os_context_register_t)(sp-2);
1106 *os_context_register_addr(context,reg_UESP) =
1107 (os_context_register_t)(sp-15);
1109 *os_context_register_addr(context,reg_ESP) = (os_context_register_t)(sp-15);
1110 #endif /* __NETBSD__ */
1111 #endif /* LISP_FEATURE_DARWIN */
1113 #elif defined(LISP_FEATURE_X86_64)
1114 *os_context_pc_addr(context) = (os_context_register_t)call_into_lisp;
1115 *os_context_register_addr(context,reg_RCX) = 0;
1116 *os_context_register_addr(context,reg_RBP) = (os_context_register_t)(sp-2);
1117 *os_context_register_addr(context,reg_RSP) = (os_context_register_t)(sp-18);
1119 /* this much of the calling convention is common to all
1121 *os_context_pc_addr(context) = (os_context_register_t)(unsigned long)code;
1122 *os_context_register_addr(context,reg_NARGS) = 0;
1123 *os_context_register_addr(context,reg_LIP) =
1124 (os_context_register_t)(unsigned long)code;
1125 *os_context_register_addr(context,reg_CFP) =
1126 (os_context_register_t)(unsigned long)current_control_frame_pointer;
1128 #ifdef ARCH_HAS_NPC_REGISTER
1129 *os_context_npc_addr(context) =
1130 4 + *os_context_pc_addr(context);
1132 #ifdef LISP_FEATURE_SPARC
1133 *os_context_register_addr(context,reg_CODE) =
1134 (os_context_register_t)(fun + FUN_POINTER_LOWTAG);
1136 FSHOW((stderr, "/arranged return to Lisp function (0x%lx)\n",
1140 #ifdef LISP_FEATURE_SB_THREAD
1142 /* FIXME: this function can go away when all lisp handlers are invoked
1143 * via arrange_return_to_lisp_function. */
1145 interrupt_thread_handler(int num, siginfo_t *info, void *v_context)
1147 os_context_t *context = (os_context_t*)arch_os_get_context(&v_context);
1149 FSHOW_SIGNAL((stderr,"/interrupt_thread_handler\n"));
1150 check_blockables_blocked_or_lose();
1152 /* let the handler enable interrupts again when it sees fit */
1153 sigaddset_deferrable(os_context_sigmask_addr(context));
1154 arrange_return_to_lisp_function(context,
1155 StaticSymbolFunction(RUN_INTERRUPTION));
1160 /* KLUDGE: Theoretically the approach we use for undefined alien
1161 * variables should work for functions as well, but on PPC/Darwin
1162 * we get bus error at bogus addresses instead, hence this workaround,
1163 * that has the added benefit of automatically discriminating between
1164 * functions and variables.
1167 undefined_alien_function(void)
1169 funcall0(StaticSymbolFunction(UNDEFINED_ALIEN_FUNCTION_ERROR));
1173 handle_guard_page_triggered(os_context_t *context,os_vm_address_t addr)
1175 struct thread *th=arch_os_get_current_thread();
1177 /* note the os_context hackery here. When the signal handler returns,
1178 * it won't go back to what it was doing ... */
1179 if(addr >= CONTROL_STACK_GUARD_PAGE(th) &&
1180 addr < CONTROL_STACK_GUARD_PAGE(th) + os_vm_page_size) {
1181 /* We hit the end of the control stack: disable guard page
1182 * protection so the error handler has some headroom, protect the
1183 * previous page so that we can catch returns from the guard page
1184 * and restore it. */
1185 corruption_warning_and_maybe_lose("Control stack exhausted");
1186 protect_control_stack_guard_page(0);
1187 protect_control_stack_return_guard_page(1);
1189 arrange_return_to_lisp_function
1190 (context, StaticSymbolFunction(CONTROL_STACK_EXHAUSTED_ERROR));
1193 else if(addr >= CONTROL_STACK_RETURN_GUARD_PAGE(th) &&
1194 addr < CONTROL_STACK_RETURN_GUARD_PAGE(th) + os_vm_page_size) {
1195 /* We're returning from the guard page: reprotect it, and
1196 * unprotect this one. This works even if we somehow missed
1197 * the return-guard-page, and hit it on our way to new
1198 * exhaustion instead. */
1199 protect_control_stack_guard_page(1);
1200 protect_control_stack_return_guard_page(0);
1203 else if (addr >= undefined_alien_address &&
1204 addr < undefined_alien_address + os_vm_page_size) {
1205 arrange_return_to_lisp_function
1206 (context, StaticSymbolFunction(UNDEFINED_ALIEN_VARIABLE_ERROR));
1213 * noise to install handlers
1216 #ifndef LISP_FEATURE_WIN32
1217 /* In Linux 2.4 synchronous signals (sigtrap & co) can be delivered if
1218 * they are blocked, in Linux 2.6 the default handler is invoked
1219 * instead that usually coredumps. One might hastily think that adding
1220 * SA_NODEFER helps, but until ~2.6.13 if SA_NODEFER is specified then
1221 * the whole sa_mask is ignored and instead of not adding the signal
1222 * in question to the mask. That means if it's not blockable the
1223 * signal must be unblocked at the beginning of signal handlers.
1225 * It turns out that NetBSD's SA_NODEFER doesn't DTRT in a different
1226 * way: if SA_NODEFER is set and the signal is in sa_mask, the signal
1227 * will be unblocked in the sigmask during the signal handler. -- RMK
1230 static volatile int sigaction_nodefer_works = -1;
1232 #define SA_NODEFER_TEST_BLOCK_SIGNAL SIGABRT
1233 #define SA_NODEFER_TEST_KILL_SIGNAL SIGUSR1
1236 sigaction_nodefer_test_handler(int signal, siginfo_t *info, void *void_context)
1238 sigset_t empty, current;
1240 sigemptyset(&empty);
1241 thread_sigmask(SIG_BLOCK, &empty, ¤t);
1242 /* There should be exactly two blocked signals: the two we added
1243 * to sa_mask when setting up the handler. NetBSD doesn't block
1244 * the signal we're handling when SA_NODEFER is set; Linux before
1245 * 2.6.13 or so also doesn't block the other signal when
1246 * SA_NODEFER is set. */
1247 for(i = 1; i < NSIG; i++)
1248 if (sigismember(¤t, i) !=
1249 (((i == SA_NODEFER_TEST_BLOCK_SIGNAL) || (i == signal)) ? 1 : 0)) {
1250 FSHOW_SIGNAL((stderr, "SA_NODEFER doesn't work, signal %d\n", i));
1251 sigaction_nodefer_works = 0;
1253 if (sigaction_nodefer_works == -1)
1254 sigaction_nodefer_works = 1;
1258 see_if_sigaction_nodefer_works(void)
1260 struct sigaction sa, old_sa;
1262 sa.sa_flags = SA_SIGINFO | SA_NODEFER;
1263 sa.sa_sigaction = sigaction_nodefer_test_handler;
1264 sigemptyset(&sa.sa_mask);
1265 sigaddset(&sa.sa_mask, SA_NODEFER_TEST_BLOCK_SIGNAL);
1266 sigaddset(&sa.sa_mask, SA_NODEFER_TEST_KILL_SIGNAL);
1267 sigaction(SA_NODEFER_TEST_KILL_SIGNAL, &sa, &old_sa);
1268 /* Make sure no signals are blocked. */
1271 sigemptyset(&empty);
1272 thread_sigmask(SIG_SETMASK, &empty, 0);
1274 kill(getpid(), SA_NODEFER_TEST_KILL_SIGNAL);
1275 while (sigaction_nodefer_works == -1);
1276 sigaction(SA_NODEFER_TEST_KILL_SIGNAL, &old_sa, NULL);
1279 #undef SA_NODEFER_TEST_BLOCK_SIGNAL
1280 #undef SA_NODEFER_TEST_KILL_SIGNAL
1283 unblock_me_trampoline(int signal, siginfo_t *info, void *void_context)
1287 sigemptyset(&unblock);
1288 sigaddset(&unblock, signal);
1289 thread_sigmask(SIG_UNBLOCK, &unblock, 0);
1290 interrupt_handle_now_handler(signal, info, void_context);
1294 low_level_unblock_me_trampoline(int signal, siginfo_t *info, void *void_context)
1298 sigemptyset(&unblock);
1299 sigaddset(&unblock, signal);
1300 thread_sigmask(SIG_UNBLOCK, &unblock, 0);
1301 (*interrupt_low_level_handlers[signal])(signal, info, void_context);
1305 undoably_install_low_level_interrupt_handler (int signal,
1306 interrupt_handler_t handler)
1308 struct sigaction sa;
1310 if (0 > signal || signal >= NSIG) {
1311 lose("bad signal number %d\n", signal);
1314 if (ARE_SAME_HANDLER(handler, SIG_DFL))
1315 sa.sa_sigaction = handler;
1316 else if (sigismember(&deferrable_sigset,signal))
1317 sa.sa_sigaction = low_level_maybe_now_maybe_later;
1318 /* The use of a trampoline appears to break the
1319 arch_os_get_context() workaround for SPARC/Linux. For now,
1320 don't use the trampoline (and so be vulnerable to the problems
1321 that SA_NODEFER is meant to solve. */
1322 #if !(defined(LISP_FEATURE_SPARC) && defined(LISP_FEATURE_LINUX))
1323 else if (!sigaction_nodefer_works &&
1324 !sigismember(&blockable_sigset, signal))
1325 sa.sa_sigaction = low_level_unblock_me_trampoline;
1328 sa.sa_sigaction = handler;
1330 sigcopyset(&sa.sa_mask, &blockable_sigset);
1331 sa.sa_flags = SA_SIGINFO | SA_RESTART
1332 | (sigaction_nodefer_works ? SA_NODEFER : 0);
1333 #ifdef LISP_FEATURE_C_STACK_IS_CONTROL_STACK
1334 if((signal==SIG_MEMORY_FAULT)
1335 #ifdef SIG_INTERRUPT_THREAD
1336 || (signal==SIG_INTERRUPT_THREAD)
1339 sa.sa_flags |= SA_ONSTACK;
1342 sigaction(signal, &sa, NULL);
1343 interrupt_low_level_handlers[signal] =
1344 (ARE_SAME_HANDLER(handler, SIG_DFL) ? 0 : handler);
1348 /* This is called from Lisp. */
1350 install_handler(int signal, void handler(int, siginfo_t*, void*))
1352 #ifndef LISP_FEATURE_WIN32
1353 struct sigaction sa;
1355 union interrupt_handler oldhandler;
1357 FSHOW((stderr, "/entering POSIX install_handler(%d, ..)\n", signal));
1360 sigaddset(&new, signal);
1361 thread_sigmask(SIG_BLOCK, &new, &old);
1363 FSHOW((stderr, "/interrupt_low_level_handlers[signal]=%x\n",
1364 (unsigned int)interrupt_low_level_handlers[signal]));
1365 if (interrupt_low_level_handlers[signal]==0) {
1366 if (ARE_SAME_HANDLER(handler, SIG_DFL) ||
1367 ARE_SAME_HANDLER(handler, SIG_IGN))
1368 sa.sa_sigaction = handler;
1369 else if (sigismember(&deferrable_sigset, signal))
1370 sa.sa_sigaction = maybe_now_maybe_later;
1371 else if (!sigaction_nodefer_works &&
1372 !sigismember(&blockable_sigset, signal))
1373 sa.sa_sigaction = unblock_me_trampoline;
1375 sa.sa_sigaction = interrupt_handle_now_handler;
1377 sigcopyset(&sa.sa_mask, &blockable_sigset);
1378 sa.sa_flags = SA_SIGINFO | SA_RESTART |
1379 (sigaction_nodefer_works ? SA_NODEFER : 0);
1380 sigaction(signal, &sa, NULL);
1383 oldhandler = interrupt_handlers[signal];
1384 interrupt_handlers[signal].c = handler;
1386 thread_sigmask(SIG_SETMASK, &old, 0);
1388 FSHOW((stderr, "/leaving POSIX install_handler(%d, ..)\n", signal));
1390 return (unsigned long)oldhandler.lisp;
1392 /* Probably-wrong Win32 hack */
1397 /* This must not go through lisp as it's allowed anytime, even when on
1400 sigabrt_handler(int signal, siginfo_t *info, void *void_context)
1402 lose("SIGABRT received.\n");
1406 interrupt_init(void)
1408 #ifndef LISP_FEATURE_WIN32
1410 SHOW("entering interrupt_init()");
1411 see_if_sigaction_nodefer_works();
1412 sigemptyset(&deferrable_sigset);
1413 sigemptyset(&blockable_sigset);
1414 sigemptyset(&gc_sigset);
1415 sigaddset_deferrable(&deferrable_sigset);
1416 sigaddset_blockable(&blockable_sigset);
1417 sigaddset_gc(&gc_sigset);
1419 /* Set up high level handler information. */
1420 for (i = 0; i < NSIG; i++) {
1421 interrupt_handlers[i].c =
1422 /* (The cast here blasts away the distinction between
1423 * SA_SIGACTION-style three-argument handlers and
1424 * signal(..)-style one-argument handlers, which is OK
1425 * because it works to call the 1-argument form where the
1426 * 3-argument form is expected.) */
1427 (void (*)(int, siginfo_t*, void*))SIG_DFL;
1429 undoably_install_low_level_interrupt_handler(SIGABRT, sigabrt_handler);
1430 SHOW("returning from interrupt_init()");
1434 #ifndef LISP_FEATURE_WIN32
1436 siginfo_code(siginfo_t *info)
1438 return info->si_code;
1440 os_vm_address_t current_memory_fault_address;
1443 lisp_memory_fault_error(os_context_t *context, os_vm_address_t addr)
1445 /* FIXME: This is lossy: if we get another memory fault (eg. from
1446 * another thread) before lisp has read this, we lose the information.
1447 * However, since this is mostly informative, we'll live with that for
1448 * now -- some address is better then no address in this case.
1450 current_memory_fault_address = addr;
1451 /* To allow debugging memory faults in signal handlers and such. */
1452 corruption_warning_and_maybe_lose("Memory fault");
1453 arrange_return_to_lisp_function(context,
1454 StaticSymbolFunction(MEMORY_FAULT_ERROR));
1459 unhandled_trap_error(os_context_t *context)
1461 lispobj context_sap;
1462 fake_foreign_function_call(context);
1463 context_sap = alloc_sap(context);
1464 #ifndef LISP_FEATURE_WIN32
1465 thread_sigmask(SIG_SETMASK, os_context_sigmask_addr(context), 0);
1467 funcall1(StaticSymbolFunction(UNHANDLED_TRAP_ERROR), context_sap);
1468 lose("UNHANDLED-TRAP-ERROR fell through");
1471 /* Common logic for trapping instructions. How we actually handle each
1472 * case is highly architecture dependent, but the overall shape is
1475 handle_trap(os_context_t *context, int trap)
1478 case trap_PendingInterrupt:
1479 FSHOW((stderr, "/<trap pending interrupt>\n"));
1480 arch_skip_instruction(context);
1481 interrupt_handle_pending(context);
1485 FSHOW((stderr, "/<trap error/cerror %d>\n", trap));
1486 interrupt_internal_error(context, trap==trap_Cerror);
1488 case trap_Breakpoint:
1489 arch_handle_breakpoint(context);
1491 case trap_FunEndBreakpoint:
1492 arch_handle_fun_end_breakpoint(context);
1494 #ifdef trap_AfterBreakpoint
1495 case trap_AfterBreakpoint:
1496 arch_handle_after_breakpoint(context);
1499 #ifdef trap_SingleStepAround
1500 case trap_SingleStepAround:
1501 case trap_SingleStepBefore:
1502 arch_handle_single_step_trap(context, trap);
1506 fake_foreign_function_call(context);
1507 lose("%%PRIMITIVE HALT called; the party is over.\n");
1509 unhandled_trap_error(context);