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 /* Test for T and not for != NIL since the value :IN-PROGRESS
543 * is used in SUB-GC as part of the mechanism to supress
545 if (SymbolValue(GC_PENDING,thread) == T) {
546 /* GC_PENDING is cleared in SUB-GC, or if another thread
547 * is doing a gc already we will get a SIG_STOP_FOR_GC and
548 * that will clear it. */
551 check_blockables_blocked_or_lose();
554 #ifndef LISP_FEATURE_WIN32
555 /* we may be here only to do the gc stuff, if interrupts are
556 * enabled run the pending handler */
557 if (SymbolValue(INTERRUPTS_ENABLED,thread) != NIL) {
558 struct interrupt_data *data = thread->interrupt_data;
560 /* There may be no pending handler, because it was only a gc
561 * that had to be executed or because pseudo atomic triggered
562 * twice for a single interrupt. For the interested reader,
563 * that may happen if an interrupt hits after the interrupted
564 * flag is cleared but before pseudo-atomic is set and a
565 * pseudo atomic is interrupted in that interrupt. */
566 if (data->pending_handler) {
568 /* If we're here as the result of a pseudo-atomic as opposed
569 * to WITHOUT-INTERRUPTS, then INTERRUPT_PENDING is already
570 * NIL, because maybe_defer_handler sets
571 * PSEUDO_ATOMIC_INTERRUPTED only if interrupts are enabled.*/
572 SetSymbolValue(INTERRUPT_PENDING, NIL, thread);
574 /* restore the saved signal mask from the original signal (the
575 * one that interrupted us during the critical section) into the
576 * os_context for the signal we're currently in the handler for.
577 * This should ensure that when we return from the handler the
578 * blocked signals are unblocked */
579 sigcopyset(os_context_sigmask_addr(context), &data->pending_mask);
581 /* This will break on sparc linux: the deferred handler really wants
582 * to be called with a void_context */
583 run_deferred_handler(data,(void *)context);
590 * the two main signal handlers:
591 * interrupt_handle_now(..)
592 * maybe_now_maybe_later(..)
594 * to which we have added interrupt_handle_now_handler(..). Why?
595 * Well, mostly because the SPARC/Linux platform doesn't quite do
596 * signals the way we want them done. The third argument in the
597 * handler isn't filled in by the kernel properly, so we fix it up
598 * ourselves in the arch_os_get_context(..) function; however, we only
599 * want to do this when we first hit the handler, and not when
600 * interrupt_handle_now(..) is being called from some other handler
601 * (when the fixup will already have been done). -- CSR, 2002-07-23
605 interrupt_handle_now(int signal, siginfo_t *info, os_context_t *context)
607 #ifdef FOREIGN_FUNCTION_CALL_FLAG
608 boolean were_in_lisp;
610 union interrupt_handler handler;
612 check_blockables_blocked_or_lose();
614 #ifndef LISP_FEATURE_WIN32
615 if (sigismember(&deferrable_sigset,signal))
616 check_interrupts_enabled_or_lose(context);
619 #if defined(LISP_FEATURE_LINUX) || defined(RESTORE_FP_CONTROL_FROM_CONTEXT)
620 /* Under Linux on some architectures, we appear to have to restore
621 the FPU control word from the context, as after the signal is
622 delivered we appear to have a null FPU control word. */
623 os_restore_fp_control(context);
626 handler = interrupt_handlers[signal];
628 if (ARE_SAME_HANDLER(handler.c, SIG_IGN)) {
632 #ifdef FOREIGN_FUNCTION_CALL_FLAG
633 were_in_lisp = !foreign_function_call_active;
637 fake_foreign_function_call(context);
640 FSHOW_SIGNAL((stderr,
641 "/entering interrupt_handle_now(%d, info, context)\n",
644 if (ARE_SAME_HANDLER(handler.c, SIG_DFL)) {
646 /* This can happen if someone tries to ignore or default one
647 * of the signals we need for runtime support, and the runtime
648 * support decides to pass on it. */
649 lose("no handler for signal %d in interrupt_handle_now(..)\n", signal);
651 } else if (lowtag_of(handler.lisp) == FUN_POINTER_LOWTAG) {
652 /* Once we've decided what to do about contexts in a
653 * return-elsewhere world (the original context will no longer
654 * be available; should we copy it or was nobody using it anyway?)
655 * then we should convert this to return-elsewhere */
657 /* CMUCL comment said "Allocate the SAPs while the interrupts
658 * are still disabled.". I (dan, 2003.08.21) assume this is
659 * because we're not in pseudoatomic and allocation shouldn't
660 * be interrupted. In which case it's no longer an issue as
661 * all our allocation from C now goes through a PA wrapper,
662 * but still, doesn't hurt.
664 * Yeah, but non-gencgc platforms don't really wrap allocation
665 * in PA. MG - 2005-08-29 */
667 lispobj info_sap,context_sap = alloc_sap(context);
668 info_sap = alloc_sap(info);
669 /* Leave deferrable signals blocked, the handler itself will
670 * allow signals again when it sees fit. */
671 #ifdef LISP_FEATURE_SB_THREAD
674 sigemptyset(&unblock);
675 sigaddset(&unblock, SIG_STOP_FOR_GC);
676 #ifdef SIG_RESUME_FROM_GC
677 sigaddset(&unblock, SIG_RESUME_FROM_GC);
679 thread_sigmask(SIG_UNBLOCK, &unblock, 0);
683 FSHOW_SIGNAL((stderr,"/calling Lisp-level handler\n"));
685 funcall3(handler.lisp,
691 FSHOW_SIGNAL((stderr,"/calling C-level handler\n"));
693 #ifndef LISP_FEATURE_WIN32
694 /* Allow signals again. */
695 thread_sigmask(SIG_SETMASK, os_context_sigmask_addr(context), 0);
697 (*handler.c)(signal, info, context);
700 #ifdef FOREIGN_FUNCTION_CALL_FLAG
704 undo_fake_foreign_function_call(context); /* block signals again */
707 FSHOW_SIGNAL((stderr,
708 "/returning from interrupt_handle_now(%d, info, context)\n",
712 /* This is called at the end of a critical section if the indications
713 * are that some signal was deferred during the section. Note that as
714 * far as C or the kernel is concerned we dealt with the signal
715 * already; we're just doing the Lisp-level processing now that we
718 run_deferred_handler(struct interrupt_data *data, void *v_context)
720 /* The pending_handler may enable interrupts and then another
721 * interrupt may hit, overwrite interrupt_data, so reset the
722 * pending handler before calling it. Trust the handler to finish
723 * with the siginfo before enabling interrupts. */
724 void (*pending_handler) (int, siginfo_t*, void*)=data->pending_handler;
726 data->pending_handler=0;
727 (*pending_handler)(data->pending_signal,&(data->pending_info), v_context);
730 #ifndef LISP_FEATURE_WIN32
732 maybe_defer_handler(void *handler, struct interrupt_data *data,
733 int signal, siginfo_t *info, os_context_t *context)
735 struct thread *thread=arch_os_get_current_thread();
737 check_blockables_blocked_or_lose();
739 if (SymbolValue(INTERRUPT_PENDING,thread) != NIL)
740 lose("interrupt already pending\n");
741 check_interrupt_context_or_lose(context);
742 /* If interrupts are disabled then INTERRUPT_PENDING is set and
743 * not PSEDUO_ATOMIC_INTERRUPTED. This is important for a pseudo
744 * atomic section inside a WITHOUT-INTERRUPTS.
746 * Also, if in_leaving_without_gcing_race_p then
747 * interrupt_handle_pending is going to be called soon, so
748 * stashing the signal away is safe.
750 if ((SymbolValue(INTERRUPTS_ENABLED,thread) == NIL) ||
751 in_leaving_without_gcing_race_p(thread)) {
752 store_signal_data_for_later(data,handler,signal,info,context);
753 SetSymbolValue(INTERRUPT_PENDING, T,thread);
754 FSHOW_SIGNAL((stderr,
755 "/maybe_defer_handler(%x,%d): deferred\n",
756 (unsigned int)handler,signal));
757 check_interrupt_context_or_lose(context);
760 /* a slightly confusing test. arch_pseudo_atomic_atomic() doesn't
761 * actually use its argument for anything on x86, so this branch
762 * may succeed even when context is null (gencgc alloc()) */
763 if (arch_pseudo_atomic_atomic(context)) {
764 store_signal_data_for_later(data,handler,signal,info,context);
765 arch_set_pseudo_atomic_interrupted(context);
766 FSHOW_SIGNAL((stderr,
767 "/maybe_defer_handler(%x,%d): deferred(PA)\n",
768 (unsigned int)handler,signal));
769 check_interrupt_context_or_lose(context);
772 FSHOW_SIGNAL((stderr,
773 "/maybe_defer_handler(%x,%d): not deferred\n",
774 (unsigned int)handler,signal));
779 store_signal_data_for_later (struct interrupt_data *data, void *handler,
781 siginfo_t *info, os_context_t *context)
783 if (data->pending_handler)
784 lose("tried to overwrite pending interrupt handler %x with %x\n",
785 data->pending_handler, handler);
787 lose("tried to defer null interrupt handler\n");
788 data->pending_handler = handler;
789 data->pending_signal = signal;
791 memcpy(&(data->pending_info), info, sizeof(siginfo_t));
793 FSHOW_SIGNAL((stderr, "/store_signal_data_for_later: signal: %d\n",
797 /* the signal mask in the context (from before we were
798 * interrupted) is copied to be restored when
799 * run_deferred_handler happens. Then the usually-blocked
800 * signals are added to the mask in the context so that we are
801 * running with blocked signals when the handler returns */
802 sigcopyset(&(data->pending_mask),os_context_sigmask_addr(context));
803 sigaddset_deferrable(os_context_sigmask_addr(context));
808 maybe_now_maybe_later(int signal, siginfo_t *info, void *void_context)
810 os_context_t *context = arch_os_get_context(&void_context);
811 struct thread *thread = arch_os_get_current_thread();
812 struct interrupt_data *data = thread->interrupt_data;
814 #if defined(LISP_FEATURE_LINUX) || defined(RESTORE_FP_CONTROL_FROM_CONTEXT)
815 os_restore_fp_control(context);
818 if(!maybe_defer_handler(interrupt_handle_now,data,signal,info,context))
819 interrupt_handle_now(signal, info, context);
823 low_level_interrupt_handle_now(int signal, siginfo_t *info,
824 os_context_t *context)
826 /* No FP control fixage needed, caller has done that. */
827 check_blockables_blocked_or_lose();
828 check_interrupts_enabled_or_lose(context);
829 (*interrupt_low_level_handlers[signal])(signal, info, context);
830 /* No Darwin context fixage needed, caller does that. */
834 low_level_maybe_now_maybe_later(int signal, siginfo_t *info, void *void_context)
836 os_context_t *context = arch_os_get_context(&void_context);
837 struct thread *thread = arch_os_get_current_thread();
838 struct interrupt_data *data = thread->interrupt_data;
840 #if defined(LISP_FEATURE_LINUX) || defined(RESTORE_FP_CONTROL_FROM_CONTEXT)
841 os_restore_fp_control(context);
844 if(!maybe_defer_handler(low_level_interrupt_handle_now,data,
845 signal,info,context))
846 low_level_interrupt_handle_now(signal, info, context);
850 #ifdef LISP_FEATURE_SB_THREAD
853 sig_stop_for_gc_handler(int signal, siginfo_t *info, void *void_context)
855 os_context_t *context = arch_os_get_context(&void_context);
857 struct thread *thread=arch_os_get_current_thread();
860 /* Test for GC_INHIBIT _first_, else we'd trap on every single
861 * pseudo atomic until gc is finally allowed. */
862 if (SymbolValue(GC_INHIBIT,thread) != NIL) {
863 SetSymbolValue(STOP_FOR_GC_PENDING,T,thread);
864 FSHOW_SIGNAL((stderr, "sig_stop_for_gc deferred (*GC-INHIBIT*)\n"));
866 } else if (arch_pseudo_atomic_atomic(context)) {
867 SetSymbolValue(STOP_FOR_GC_PENDING,T,thread);
868 arch_set_pseudo_atomic_interrupted(context);
869 FSHOW_SIGNAL((stderr,"sig_stop_for_gc deferred (PA)\n"));
873 /* Not PA and GC not inhibited -- we can stop now. */
875 /* need the context stored so it can have registers scavenged */
876 fake_foreign_function_call(context);
878 /* Block everything. */
880 thread_sigmask(SIG_BLOCK,&ss,0);
882 /* Not pending anymore. */
883 SetSymbolValue(GC_PENDING,NIL,thread);
884 SetSymbolValue(STOP_FOR_GC_PENDING,NIL,thread);
886 if(thread_state(thread)!=STATE_RUNNING) {
887 lose("sig_stop_for_gc_handler: wrong thread state: %ld\n",
888 fixnum_value(thread->state));
891 set_thread_state(thread,STATE_SUSPENDED);
892 FSHOW_SIGNAL((stderr,"suspended\n"));
894 wait_for_thread_state_change(thread, STATE_SUSPENDED);
895 FSHOW_SIGNAL((stderr,"resumed\n"));
897 if(thread_state(thread)!=STATE_RUNNING) {
898 lose("sig_stop_for_gc_handler: wrong thread state on wakeup: %ld\n",
899 fixnum_value(thread_state(thread)));
902 undo_fake_foreign_function_call(context);
908 interrupt_handle_now_handler(int signal, siginfo_t *info, void *void_context)
910 os_context_t *context = arch_os_get_context(&void_context);
911 #if defined(LISP_FEATURE_LINUX) || defined(RESTORE_FP_CONTROL_FROM_CONTEXT)
912 os_restore_fp_control(context);
913 #ifndef LISP_FEATURE_WIN32
914 if ((signal == SIGILL) || (signal == SIGBUS)
915 #ifndef LISP_FEATURE_LINUX
916 || (signal == SIGEMT)
919 corruption_warning_and_maybe_lose("Signal %d recieved", signal);
922 interrupt_handle_now(signal, info, context);
925 /* manipulate the signal context and stack such that when the handler
926 * returns, it will call function instead of whatever it was doing
930 #if (defined(LISP_FEATURE_X86) || defined(LISP_FEATURE_X86_64))
931 extern int *context_eflags_addr(os_context_t *context);
934 extern lispobj call_into_lisp(lispobj fun, lispobj *args, int nargs);
935 extern void post_signal_tramp(void);
936 extern void call_into_lisp_tramp(void);
938 arrange_return_to_lisp_function(os_context_t *context, lispobj function)
940 #if !(defined(LISP_FEATURE_X86) || defined(LISP_FEATURE_X86_64))
941 void * fun=native_pointer(function);
942 void *code = &(((struct simple_fun *) fun)->code);
945 /* Build a stack frame showing `interrupted' so that the
946 * user's backtrace makes (as much) sense (as usual) */
948 /* FIXME: what about restoring fp state? */
949 /* FIXME: what about restoring errno? */
950 #ifdef LISP_FEATURE_X86
951 /* Suppose the existence of some function that saved all
952 * registers, called call_into_lisp, then restored GP registers and
953 * returned. It would look something like this:
961 pushl {address of function to call}
962 call 0x8058db0 <call_into_lisp>
969 * What we do here is set up the stack that call_into_lisp would
970 * expect to see if it had been called by this code, and frob the
971 * signal context so that signal return goes directly to call_into_lisp,
972 * and when that function (and the lisp function it invoked) returns,
973 * it returns to the second half of this imaginary function which
974 * restores all registers and returns to C
976 * For this to work, the latter part of the imaginary function
977 * must obviously exist in reality. That would be post_signal_tramp
980 u32 *sp=(u32 *)*os_context_register_addr(context,reg_ESP);
982 #if defined(LISP_FEATURE_DARWIN)
983 u32 *register_save_area = (u32 *)os_validate(0, 0x40);
985 FSHOW_SIGNAL((stderr, "/arrange_return_to_lisp_function: preparing to go to function %x, sp: %x\n", function, sp));
986 FSHOW_SIGNAL((stderr, "/arrange_return_to_lisp_function: context: %x, &context %x\n", context, &context));
988 /* 1. os_validate (malloc/mmap) register_save_block
989 * 2. copy register state into register_save_block
990 * 3. put a pointer to register_save_block in a register in the context
991 * 4. set the context's EIP to point to a trampoline which:
992 * a. builds the fake stack frame from the block
994 * c. calls the function
997 *register_save_area = *os_context_pc_addr(context);
998 *(register_save_area + 1) = function;
999 *(register_save_area + 2) = *os_context_register_addr(context,reg_EDI);
1000 *(register_save_area + 3) = *os_context_register_addr(context,reg_ESI);
1001 *(register_save_area + 4) = *os_context_register_addr(context,reg_EDX);
1002 *(register_save_area + 5) = *os_context_register_addr(context,reg_ECX);
1003 *(register_save_area + 6) = *os_context_register_addr(context,reg_EBX);
1004 *(register_save_area + 7) = *os_context_register_addr(context,reg_EAX);
1005 *(register_save_area + 8) = *context_eflags_addr(context);
1007 *os_context_pc_addr(context) =
1008 (os_context_register_t) call_into_lisp_tramp;
1009 *os_context_register_addr(context,reg_ECX) =
1010 (os_context_register_t) register_save_area;
1013 /* return address for call_into_lisp: */
1014 *(sp-15) = (u32)post_signal_tramp;
1015 *(sp-14) = function; /* args for call_into_lisp : function*/
1016 *(sp-13) = 0; /* arg array */
1017 *(sp-12) = 0; /* no. args */
1018 /* this order matches that used in POPAD */
1019 *(sp-11)=*os_context_register_addr(context,reg_EDI);
1020 *(sp-10)=*os_context_register_addr(context,reg_ESI);
1022 *(sp-9)=*os_context_register_addr(context,reg_ESP)-8;
1023 /* POPAD ignores the value of ESP: */
1025 *(sp-7)=*os_context_register_addr(context,reg_EBX);
1027 *(sp-6)=*os_context_register_addr(context,reg_EDX);
1028 *(sp-5)=*os_context_register_addr(context,reg_ECX);
1029 *(sp-4)=*os_context_register_addr(context,reg_EAX);
1030 *(sp-3)=*context_eflags_addr(context);
1031 *(sp-2)=*os_context_register_addr(context,reg_EBP);
1032 *(sp-1)=*os_context_pc_addr(context);
1036 #elif defined(LISP_FEATURE_X86_64)
1037 u64 *sp=(u64 *)*os_context_register_addr(context,reg_RSP);
1039 /* return address for call_into_lisp: */
1040 *(sp-18) = (u64)post_signal_tramp;
1042 *(sp-17)=*os_context_register_addr(context,reg_R15);
1043 *(sp-16)=*os_context_register_addr(context,reg_R14);
1044 *(sp-15)=*os_context_register_addr(context,reg_R13);
1045 *(sp-14)=*os_context_register_addr(context,reg_R12);
1046 *(sp-13)=*os_context_register_addr(context,reg_R11);
1047 *(sp-12)=*os_context_register_addr(context,reg_R10);
1048 *(sp-11)=*os_context_register_addr(context,reg_R9);
1049 *(sp-10)=*os_context_register_addr(context,reg_R8);
1050 *(sp-9)=*os_context_register_addr(context,reg_RDI);
1051 *(sp-8)=*os_context_register_addr(context,reg_RSI);
1052 /* skip RBP and RSP */
1053 *(sp-7)=*os_context_register_addr(context,reg_RBX);
1054 *(sp-6)=*os_context_register_addr(context,reg_RDX);
1055 *(sp-5)=*os_context_register_addr(context,reg_RCX);
1056 *(sp-4)=*os_context_register_addr(context,reg_RAX);
1057 *(sp-3)=*context_eflags_addr(context);
1058 *(sp-2)=*os_context_register_addr(context,reg_RBP);
1059 *(sp-1)=*os_context_pc_addr(context);
1061 *os_context_register_addr(context,reg_RDI) =
1062 (os_context_register_t)function; /* function */
1063 *os_context_register_addr(context,reg_RSI) = 0; /* arg. array */
1064 *os_context_register_addr(context,reg_RDX) = 0; /* no. args */
1066 struct thread *th=arch_os_get_current_thread();
1067 build_fake_control_stack_frames(th,context);
1070 #ifdef LISP_FEATURE_X86
1072 #if !defined(LISP_FEATURE_DARWIN)
1073 *os_context_pc_addr(context) = (os_context_register_t)call_into_lisp;
1074 *os_context_register_addr(context,reg_ECX) = 0;
1075 *os_context_register_addr(context,reg_EBP) = (os_context_register_t)(sp-2);
1077 *os_context_register_addr(context,reg_UESP) =
1078 (os_context_register_t)(sp-15);
1080 *os_context_register_addr(context,reg_ESP) = (os_context_register_t)(sp-15);
1081 #endif /* __NETBSD__ */
1082 #endif /* LISP_FEATURE_DARWIN */
1084 #elif defined(LISP_FEATURE_X86_64)
1085 *os_context_pc_addr(context) = (os_context_register_t)call_into_lisp;
1086 *os_context_register_addr(context,reg_RCX) = 0;
1087 *os_context_register_addr(context,reg_RBP) = (os_context_register_t)(sp-2);
1088 *os_context_register_addr(context,reg_RSP) = (os_context_register_t)(sp-18);
1090 /* this much of the calling convention is common to all
1092 *os_context_pc_addr(context) = (os_context_register_t)(unsigned long)code;
1093 *os_context_register_addr(context,reg_NARGS) = 0;
1094 *os_context_register_addr(context,reg_LIP) =
1095 (os_context_register_t)(unsigned long)code;
1096 *os_context_register_addr(context,reg_CFP) =
1097 (os_context_register_t)(unsigned long)current_control_frame_pointer;
1099 #ifdef ARCH_HAS_NPC_REGISTER
1100 *os_context_npc_addr(context) =
1101 4 + *os_context_pc_addr(context);
1103 #ifdef LISP_FEATURE_SPARC
1104 *os_context_register_addr(context,reg_CODE) =
1105 (os_context_register_t)(fun + FUN_POINTER_LOWTAG);
1107 FSHOW((stderr, "/arranged return to Lisp function (0x%lx)\n",
1111 #ifdef LISP_FEATURE_SB_THREAD
1113 /* FIXME: this function can go away when all lisp handlers are invoked
1114 * via arrange_return_to_lisp_function. */
1116 interrupt_thread_handler(int num, siginfo_t *info, void *v_context)
1118 os_context_t *context = (os_context_t*)arch_os_get_context(&v_context);
1120 FSHOW_SIGNAL((stderr,"/interrupt_thread_handler\n"));
1121 check_blockables_blocked_or_lose();
1123 /* let the handler enable interrupts again when it sees fit */
1124 sigaddset_deferrable(os_context_sigmask_addr(context));
1125 arrange_return_to_lisp_function(context,
1126 StaticSymbolFunction(RUN_INTERRUPTION));
1131 /* KLUDGE: Theoretically the approach we use for undefined alien
1132 * variables should work for functions as well, but on PPC/Darwin
1133 * we get bus error at bogus addresses instead, hence this workaround,
1134 * that has the added benefit of automatically discriminating between
1135 * functions and variables.
1138 undefined_alien_function(void)
1140 funcall0(StaticSymbolFunction(UNDEFINED_ALIEN_FUNCTION_ERROR));
1144 handle_guard_page_triggered(os_context_t *context,os_vm_address_t addr)
1146 struct thread *th=arch_os_get_current_thread();
1148 /* note the os_context hackery here. When the signal handler returns,
1149 * it won't go back to what it was doing ... */
1150 if(addr >= CONTROL_STACK_GUARD_PAGE(th) &&
1151 addr < CONTROL_STACK_GUARD_PAGE(th) + os_vm_page_size) {
1152 /* We hit the end of the control stack: disable guard page
1153 * protection so the error handler has some headroom, protect the
1154 * previous page so that we can catch returns from the guard page
1155 * and restore it. */
1156 corruption_warning_and_maybe_lose("Control stack exhausted");
1157 protect_control_stack_guard_page(0);
1158 protect_control_stack_return_guard_page(1);
1160 arrange_return_to_lisp_function
1161 (context, StaticSymbolFunction(CONTROL_STACK_EXHAUSTED_ERROR));
1164 else if(addr >= CONTROL_STACK_RETURN_GUARD_PAGE(th) &&
1165 addr < CONTROL_STACK_RETURN_GUARD_PAGE(th) + os_vm_page_size) {
1166 /* We're returning from the guard page: reprotect it, and
1167 * unprotect this one. This works even if we somehow missed
1168 * the return-guard-page, and hit it on our way to new
1169 * exhaustion instead. */
1170 protect_control_stack_guard_page(1);
1171 protect_control_stack_return_guard_page(0);
1174 else if (addr >= undefined_alien_address &&
1175 addr < undefined_alien_address + os_vm_page_size) {
1176 arrange_return_to_lisp_function
1177 (context, StaticSymbolFunction(UNDEFINED_ALIEN_VARIABLE_ERROR));
1184 * noise to install handlers
1187 #ifndef LISP_FEATURE_WIN32
1188 /* In Linux 2.4 synchronous signals (sigtrap & co) can be delivered if
1189 * they are blocked, in Linux 2.6 the default handler is invoked
1190 * instead that usually coredumps. One might hastily think that adding
1191 * SA_NODEFER helps, but until ~2.6.13 if SA_NODEFER is specified then
1192 * the whole sa_mask is ignored and instead of not adding the signal
1193 * in question to the mask. That means if it's not blockable the
1194 * signal must be unblocked at the beginning of signal handlers.
1196 * It turns out that NetBSD's SA_NODEFER doesn't DTRT in a different
1197 * way: if SA_NODEFER is set and the signal is in sa_mask, the signal
1198 * will be unblocked in the sigmask during the signal handler. -- RMK
1201 static volatile int sigaction_nodefer_works = -1;
1203 #define SA_NODEFER_TEST_BLOCK_SIGNAL SIGABRT
1204 #define SA_NODEFER_TEST_KILL_SIGNAL SIGUSR1
1207 sigaction_nodefer_test_handler(int signal, siginfo_t *info, void *void_context)
1209 sigset_t empty, current;
1211 sigemptyset(&empty);
1212 thread_sigmask(SIG_BLOCK, &empty, ¤t);
1213 /* There should be exactly two blocked signals: the two we added
1214 * to sa_mask when setting up the handler. NetBSD doesn't block
1215 * the signal we're handling when SA_NODEFER is set; Linux before
1216 * 2.6.13 or so also doesn't block the other signal when
1217 * SA_NODEFER is set. */
1218 for(i = 1; i < NSIG; i++)
1219 if (sigismember(¤t, i) !=
1220 (((i == SA_NODEFER_TEST_BLOCK_SIGNAL) || (i == signal)) ? 1 : 0)) {
1221 FSHOW_SIGNAL((stderr, "SA_NODEFER doesn't work, signal %d\n", i));
1222 sigaction_nodefer_works = 0;
1224 if (sigaction_nodefer_works == -1)
1225 sigaction_nodefer_works = 1;
1229 see_if_sigaction_nodefer_works(void)
1231 struct sigaction sa, old_sa;
1233 sa.sa_flags = SA_SIGINFO | SA_NODEFER;
1234 sa.sa_sigaction = sigaction_nodefer_test_handler;
1235 sigemptyset(&sa.sa_mask);
1236 sigaddset(&sa.sa_mask, SA_NODEFER_TEST_BLOCK_SIGNAL);
1237 sigaddset(&sa.sa_mask, SA_NODEFER_TEST_KILL_SIGNAL);
1238 sigaction(SA_NODEFER_TEST_KILL_SIGNAL, &sa, &old_sa);
1239 /* Make sure no signals are blocked. */
1242 sigemptyset(&empty);
1243 thread_sigmask(SIG_SETMASK, &empty, 0);
1245 kill(getpid(), SA_NODEFER_TEST_KILL_SIGNAL);
1246 while (sigaction_nodefer_works == -1);
1247 sigaction(SA_NODEFER_TEST_KILL_SIGNAL, &old_sa, NULL);
1250 #undef SA_NODEFER_TEST_BLOCK_SIGNAL
1251 #undef SA_NODEFER_TEST_KILL_SIGNAL
1254 unblock_me_trampoline(int signal, siginfo_t *info, void *void_context)
1258 sigemptyset(&unblock);
1259 sigaddset(&unblock, signal);
1260 thread_sigmask(SIG_UNBLOCK, &unblock, 0);
1261 interrupt_handle_now_handler(signal, info, void_context);
1265 low_level_unblock_me_trampoline(int signal, siginfo_t *info, void *void_context)
1269 sigemptyset(&unblock);
1270 sigaddset(&unblock, signal);
1271 thread_sigmask(SIG_UNBLOCK, &unblock, 0);
1272 (*interrupt_low_level_handlers[signal])(signal, info, void_context);
1276 undoably_install_low_level_interrupt_handler (int signal,
1277 interrupt_handler_t handler)
1279 struct sigaction sa;
1281 if (0 > signal || signal >= NSIG) {
1282 lose("bad signal number %d\n", signal);
1285 if (ARE_SAME_HANDLER(handler, SIG_DFL))
1286 sa.sa_sigaction = handler;
1287 else if (sigismember(&deferrable_sigset,signal))
1288 sa.sa_sigaction = low_level_maybe_now_maybe_later;
1289 /* The use of a trampoline appears to break the
1290 arch_os_get_context() workaround for SPARC/Linux. For now,
1291 don't use the trampoline (and so be vulnerable to the problems
1292 that SA_NODEFER is meant to solve. */
1293 #if !(defined(LISP_FEATURE_SPARC) && defined(LISP_FEATURE_LINUX))
1294 else if (!sigaction_nodefer_works &&
1295 !sigismember(&blockable_sigset, signal))
1296 sa.sa_sigaction = low_level_unblock_me_trampoline;
1299 sa.sa_sigaction = handler;
1301 sigcopyset(&sa.sa_mask, &blockable_sigset);
1302 sa.sa_flags = SA_SIGINFO | SA_RESTART
1303 | (sigaction_nodefer_works ? SA_NODEFER : 0);
1304 #ifdef LISP_FEATURE_C_STACK_IS_CONTROL_STACK
1305 if((signal==SIG_MEMORY_FAULT)
1306 #ifdef SIG_INTERRUPT_THREAD
1307 || (signal==SIG_INTERRUPT_THREAD)
1310 sa.sa_flags |= SA_ONSTACK;
1313 sigaction(signal, &sa, NULL);
1314 interrupt_low_level_handlers[signal] =
1315 (ARE_SAME_HANDLER(handler, SIG_DFL) ? 0 : handler);
1319 /* This is called from Lisp. */
1321 install_handler(int signal, void handler(int, siginfo_t*, void*))
1323 #ifndef LISP_FEATURE_WIN32
1324 struct sigaction sa;
1326 union interrupt_handler oldhandler;
1328 FSHOW((stderr, "/entering POSIX install_handler(%d, ..)\n", signal));
1331 sigaddset(&new, signal);
1332 thread_sigmask(SIG_BLOCK, &new, &old);
1334 FSHOW((stderr, "/interrupt_low_level_handlers[signal]=%x\n",
1335 (unsigned int)interrupt_low_level_handlers[signal]));
1336 if (interrupt_low_level_handlers[signal]==0) {
1337 if (ARE_SAME_HANDLER(handler, SIG_DFL) ||
1338 ARE_SAME_HANDLER(handler, SIG_IGN))
1339 sa.sa_sigaction = handler;
1340 else if (sigismember(&deferrable_sigset, signal))
1341 sa.sa_sigaction = maybe_now_maybe_later;
1342 else if (!sigaction_nodefer_works &&
1343 !sigismember(&blockable_sigset, signal))
1344 sa.sa_sigaction = unblock_me_trampoline;
1346 sa.sa_sigaction = interrupt_handle_now_handler;
1348 sigcopyset(&sa.sa_mask, &blockable_sigset);
1349 sa.sa_flags = SA_SIGINFO | SA_RESTART |
1350 (sigaction_nodefer_works ? SA_NODEFER : 0);
1351 sigaction(signal, &sa, NULL);
1354 oldhandler = interrupt_handlers[signal];
1355 interrupt_handlers[signal].c = handler;
1357 thread_sigmask(SIG_SETMASK, &old, 0);
1359 FSHOW((stderr, "/leaving POSIX install_handler(%d, ..)\n", signal));
1361 return (unsigned long)oldhandler.lisp;
1363 /* Probably-wrong Win32 hack */
1368 /* This must not go through lisp as it's allowed anytime, even when on
1371 sigabrt_handler(int signal, siginfo_t *info, void *void_context)
1373 lose("SIGABRT received.\n");
1377 interrupt_init(void)
1379 #ifndef LISP_FEATURE_WIN32
1381 SHOW("entering interrupt_init()");
1382 see_if_sigaction_nodefer_works();
1383 sigemptyset(&deferrable_sigset);
1384 sigemptyset(&blockable_sigset);
1385 sigaddset_deferrable(&deferrable_sigset);
1386 sigaddset_blockable(&blockable_sigset);
1388 /* Set up high level handler information. */
1389 for (i = 0; i < NSIG; i++) {
1390 interrupt_handlers[i].c =
1391 /* (The cast here blasts away the distinction between
1392 * SA_SIGACTION-style three-argument handlers and
1393 * signal(..)-style one-argument handlers, which is OK
1394 * because it works to call the 1-argument form where the
1395 * 3-argument form is expected.) */
1396 (void (*)(int, siginfo_t*, void*))SIG_DFL;
1398 undoably_install_low_level_interrupt_handler(SIGABRT, sigabrt_handler);
1399 SHOW("returning from interrupt_init()");
1403 #ifndef LISP_FEATURE_WIN32
1405 siginfo_code(siginfo_t *info)
1407 return info->si_code;
1409 os_vm_address_t current_memory_fault_address;
1412 lisp_memory_fault_error(os_context_t *context, os_vm_address_t addr)
1414 /* FIXME: This is lossy: if we get another memory fault (eg. from
1415 * another thread) before lisp has read this, we lose the information.
1416 * However, since this is mostly informative, we'll live with that for
1417 * now -- some address is better then no address in this case.
1419 current_memory_fault_address = addr;
1420 /* To allow debugging memory faults in signal handlers and such. */
1421 corruption_warning_and_maybe_lose("Memory fault");
1422 arrange_return_to_lisp_function(context,
1423 StaticSymbolFunction(MEMORY_FAULT_ERROR));
1428 unhandled_trap_error(os_context_t *context)
1430 lispobj context_sap;
1431 fake_foreign_function_call(context);
1432 context_sap = alloc_sap(context);
1433 #ifndef LISP_FEATURE_WIN32
1434 thread_sigmask(SIG_SETMASK, os_context_sigmask_addr(context), 0);
1436 funcall1(StaticSymbolFunction(UNHANDLED_TRAP_ERROR), context_sap);
1437 lose("UNHANDLED-TRAP-ERROR fell through");
1440 /* Common logic for trapping instructions. How we actually handle each
1441 * case is highly architecture dependent, but the overall shape is
1444 handle_trap(os_context_t *context, int trap)
1447 case trap_PendingInterrupt:
1448 FSHOW((stderr, "/<trap pending interrupt>\n"));
1449 arch_skip_instruction(context);
1450 interrupt_handle_pending(context);
1454 FSHOW((stderr, "/<trap error/cerror %d>\n", trap));
1455 interrupt_internal_error(context, trap==trap_Cerror);
1457 case trap_Breakpoint:
1458 arch_handle_breakpoint(context);
1460 case trap_FunEndBreakpoint:
1461 arch_handle_fun_end_breakpoint(context);
1463 #ifdef trap_AfterBreakpoint
1464 case trap_AfterBreakpoint:
1465 arch_handle_after_breakpoint(context);
1468 #ifdef trap_SingleStepAround
1469 case trap_SingleStepAround:
1470 case trap_SingleStepBefore:
1471 arch_handle_single_step_trap(context, trap);
1475 fake_foreign_function_call(context);
1476 lose("%%PRIMITIVE HALT called; the party is over.\n");
1478 unhandled_trap_error(context);