2 * interrupt-handling magic
6 * This software is part of the SBCL system. See the README file for
9 * This software is derived from the CMU CL system, which was
10 * written at Carnegie Mellon University and released into the
11 * public domain. The software is in the public domain and is
12 * provided with absolutely no warranty. See the COPYING and CREDITS
13 * files for more information.
17 /* As far as I can tell, what's going on here is:
19 * In the case of most signals, when Lisp asks us to handle the
20 * signal, the outermost handler (the one actually passed to UNIX) is
21 * either interrupt_handle_now(..) or maybe_now_maybe_later(..).
22 * In that case, the Lisp-level handler is stored in interrupt_handlers[..]
23 * and interrupt_low_level_handlers[..] is cleared.
25 * However, some signals need special handling, e.g.
27 * o the SIGSEGV (for e.g. Linux) or SIGBUS (for e.g. FreeBSD) used by the
28 * garbage collector to detect violations of write protection,
29 * because some cases of such signals (e.g. GC-related violations of
30 * write protection) are handled at C level and never passed on to
31 * Lisp. For such signals, we still store any Lisp-level handler
32 * in interrupt_handlers[..], but for the outermost handle we use
33 * the value from interrupt_low_level_handlers[..], instead of the
34 * ordinary interrupt_handle_now(..) or interrupt_handle_later(..).
36 * o the SIGTRAP (Linux/Alpha) which Lisp code uses to handle breakpoints,
37 * pseudo-atomic sections, and some classes of error (e.g. "function
38 * not defined"). This never goes anywhere near the Lisp handlers at all.
39 * See runtime/alpha-arch.c and code/signal.lisp
41 * - WHN 20000728, dan 20010128 */
49 #include <sys/types.h>
50 #ifndef LISP_FEATURE_WIN32
58 #include "interrupt.h"
66 #include "genesis/fdefn.h"
67 #include "genesis/simple-fun.h"
68 #include "genesis/cons.h"
70 static void run_deferred_handler(struct interrupt_data *data, void *v_context);
71 #ifndef LISP_FEATURE_WIN32
72 static void store_signal_data_for_later (struct interrupt_data *data,
73 void *handler, int signal,
75 os_context_t *context);
76 boolean interrupt_maybe_gc_int(int signal, siginfo_t *info, void *v_context);
79 sigaddset_deferrable(sigset_t *s)
83 sigaddset(s, SIGQUIT);
84 sigaddset(s, SIGPIPE);
85 sigaddset(s, SIGALRM);
87 sigaddset(s, SIGTSTP);
88 sigaddset(s, SIGCHLD);
90 sigaddset(s, SIGXCPU);
91 sigaddset(s, SIGXFSZ);
92 sigaddset(s, SIGVTALRM);
93 sigaddset(s, SIGPROF);
94 sigaddset(s, SIGWINCH);
96 #if !((defined(LISP_FEATURE_DARWIN) || defined(LISP_FEATURE_FREEBSD)) && defined(LISP_FEATURE_SB_THREAD))
97 sigaddset(s, SIGUSR1);
98 sigaddset(s, SIGUSR2);
101 #ifdef LISP_FEATURE_SB_THREAD
102 sigaddset(s, SIG_INTERRUPT_THREAD);
107 sigaddset_blockable(sigset_t *s)
109 sigaddset_deferrable(s);
110 #ifdef LISP_FEATURE_SB_THREAD
111 #ifdef SIG_RESUME_FROM_GC
112 sigaddset(s, SIG_RESUME_FROM_GC);
114 sigaddset(s, SIG_STOP_FOR_GC);
118 /* initialized in interrupt_init */
119 static sigset_t deferrable_sigset;
120 static sigset_t blockable_sigset;
124 check_blockables_blocked_or_lose(void)
126 #if !defined(LISP_FEATURE_WIN32)
127 /* Get the current sigmask, by blocking the empty set. */
128 sigset_t empty,current;
131 thread_sigmask(SIG_BLOCK, &empty, ¤t);
132 for(i = 1; i < NSIG; i++) {
133 if (sigismember(&blockable_sigset, i) && !sigismember(¤t, i))
134 lose("blockable signal %d not blocked\n",i);
140 check_gc_signals_unblocked_or_lose(void)
142 #ifdef LISP_FEATURE_SB_THREAD
143 # if !defined(LISP_FEATURE_WIN32)
144 /* Get the current sigmask, by blocking the empty set. */
145 sigset_t empty,current;
147 thread_sigmask(SIG_BLOCK, &empty, ¤t);
148 if (sigismember(¤t, SIG_STOP_FOR_GC))
149 lose("SIG_STOP_FOR_GC blocked in thread %p at a bad place\n",
150 arch_os_get_current_thread());
151 # if defined(SIG_RESUME_FROM_GC)
152 if (sigismember(¤t, SIG_RESUME_FROM_GC))
153 lose("SIG_RESUME_FROM_GC blocked in thread %p at a bad place\n",
154 arch_os_get_current_thread());
161 unblock_gc_signals(void)
163 #ifdef LISP_FEATURE_SB_THREAD
166 #if defined(SIG_RESUME_FROM_GC)
167 sigaddset(&new,SIG_RESUME_FROM_GC);
169 sigaddset(&new,SIG_STOP_FOR_GC);
170 thread_sigmask(SIG_UNBLOCK,&new,0);
175 check_interrupts_enabled_or_lose(os_context_t *context)
177 struct thread *thread=arch_os_get_current_thread();
178 if (SymbolValue(INTERRUPTS_ENABLED,thread) == NIL)
179 lose("interrupts not enabled\n");
181 #if !defined(LISP_FEATURE_X86) && !defined(LISP_FEATURE_X86_64)
182 (!foreign_function_call_active) &&
184 arch_pseudo_atomic_atomic(context))
185 lose ("in pseudo atomic section\n");
188 /* When we catch an internal error, should we pass it back to Lisp to
189 * be handled in a high-level way? (Early in cold init, the answer is
190 * 'no', because Lisp is still too brain-dead to handle anything.
191 * After sufficient initialization has been completed, the answer
193 boolean internal_errors_enabled = 0;
195 #ifndef LISP_FEATURE_WIN32
196 static void (*interrupt_low_level_handlers[NSIG]) (int, siginfo_t*, void*);
198 union interrupt_handler interrupt_handlers[NSIG];
200 /* At the toplevel repl we routinely call this function. The signal
201 * mask ought to be clear anyway most of the time, but may be non-zero
202 * if we were interrupted e.g. while waiting for a queue. */
205 reset_signal_mask(void)
207 #ifndef LISP_FEATURE_WIN32
210 thread_sigmask(SIG_SETMASK,&new,0);
215 block_blockable_signals(void)
217 #ifndef LISP_FEATURE_WIN32
218 thread_sigmask(SIG_BLOCK, &blockable_sigset, 0);
223 block_deferrable_signals(void)
225 #ifndef LISP_FEATURE_WIN32
226 thread_sigmask(SIG_BLOCK, &deferrable_sigset, 0);
232 * utility routines used by various signal handlers
236 build_fake_control_stack_frames(struct thread *th,os_context_t *context)
238 #ifndef LISP_FEATURE_C_STACK_IS_CONTROL_STACK
242 /* Build a fake stack frame or frames */
244 current_control_frame_pointer =
245 (lispobj *)(unsigned long)
246 (*os_context_register_addr(context, reg_CSP));
247 if ((lispobj *)(unsigned long)
248 (*os_context_register_addr(context, reg_CFP))
249 == current_control_frame_pointer) {
250 /* There is a small window during call where the callee's
251 * frame isn't built yet. */
252 if (lowtag_of(*os_context_register_addr(context, reg_CODE))
253 == FUN_POINTER_LOWTAG) {
254 /* We have called, but not built the new frame, so
255 * build it for them. */
256 current_control_frame_pointer[0] =
257 *os_context_register_addr(context, reg_OCFP);
258 current_control_frame_pointer[1] =
259 *os_context_register_addr(context, reg_LRA);
260 current_control_frame_pointer += 8;
261 /* Build our frame on top of it. */
262 oldcont = (lispobj)(*os_context_register_addr(context, reg_CFP));
265 /* We haven't yet called, build our frame as if the
266 * partial frame wasn't there. */
267 oldcont = (lispobj)(*os_context_register_addr(context, reg_OCFP));
270 /* We can't tell whether we are still in the caller if it had to
271 * allocate a stack frame due to stack arguments. */
272 /* This observation provoked some past CMUCL maintainer to ask
273 * "Can anything strange happen during return?" */
276 oldcont = (lispobj)(*os_context_register_addr(context, reg_CFP));
279 current_control_stack_pointer = current_control_frame_pointer + 8;
281 current_control_frame_pointer[0] = oldcont;
282 current_control_frame_pointer[1] = NIL;
283 current_control_frame_pointer[2] =
284 (lispobj)(*os_context_register_addr(context, reg_CODE));
288 /* Stores the context for gc to scavange and builds fake stack
291 fake_foreign_function_call(os_context_t *context)
294 struct thread *thread=arch_os_get_current_thread();
296 /* context_index incrementing must not be interrupted */
297 check_blockables_blocked_or_lose();
299 /* Get current Lisp state from context. */
301 dynamic_space_free_pointer =
302 (lispobj *)(unsigned long)
303 (*os_context_register_addr(context, reg_ALLOC));
304 /* fprintf(stderr,"dynamic_space_free_pointer: %p\n", dynamic_space_free_pointer); */
305 #if defined(LISP_FEATURE_ALPHA)
306 if ((long)dynamic_space_free_pointer & 1) {
307 lose("dead in fake_foreign_function_call, context = %x\n", context);
312 current_binding_stack_pointer =
313 (lispobj *)(unsigned long)
314 (*os_context_register_addr(context, reg_BSP));
317 build_fake_control_stack_frames(thread,context);
319 /* Do dynamic binding of the active interrupt context index
320 * and save the context in the context array. */
322 fixnum_value(SymbolValue(FREE_INTERRUPT_CONTEXT_INDEX,thread));
324 if (context_index >= MAX_INTERRUPTS) {
325 lose("maximum interrupt nesting depth (%d) exceeded\n", MAX_INTERRUPTS);
328 bind_variable(FREE_INTERRUPT_CONTEXT_INDEX,
329 make_fixnum(context_index + 1),thread);
331 thread->interrupt_contexts[context_index] = context;
333 /* no longer in Lisp now */
334 foreign_function_call_active = 1;
337 /* blocks all blockable signals. If you are calling from a signal handler,
338 * the usual signal mask will be restored from the context when the handler
339 * finishes. Otherwise, be careful */
341 undo_fake_foreign_function_call(os_context_t *context)
343 struct thread *thread=arch_os_get_current_thread();
344 /* Block all blockable signals. */
345 block_blockable_signals();
347 /* going back into Lisp */
348 foreign_function_call_active = 0;
350 /* Undo dynamic binding of FREE_INTERRUPT_CONTEXT_INDEX */
354 /* Put the dynamic space free pointer back into the context. */
355 *os_context_register_addr(context, reg_ALLOC) =
356 (unsigned long) dynamic_space_free_pointer
357 | (*os_context_register_addr(context, reg_ALLOC)
360 ((unsigned long)(*os_context_register_addr(context, reg_ALLOC)) & ~LOWTAG_MASK)
361 | ((unsigned long) dynamic_space_free_pointer & LOWTAG_MASK);
366 /* a handler for the signal caused by execution of a trap opcode
367 * signalling an internal error */
369 interrupt_internal_error(os_context_t *context, boolean continuable)
373 fake_foreign_function_call(context);
375 if (!internal_errors_enabled) {
376 describe_internal_error(context);
377 /* There's no good way to recover from an internal error
378 * before the Lisp error handling mechanism is set up. */
379 lose("internal error too early in init, can't recover\n");
382 /* Allocate the SAP object while the interrupts are still
384 context_sap = alloc_sap(context);
386 #ifndef LISP_FEATURE_WIN32
387 thread_sigmask(SIG_SETMASK, os_context_sigmask_addr(context), 0);
390 SHOW("in interrupt_internal_error");
392 /* Display some rudimentary debugging information about the
393 * error, so that even if the Lisp error handler gets badly
394 * confused, we have a chance to determine what's going on. */
395 describe_internal_error(context);
397 funcall2(SymbolFunction(INTERNAL_ERROR), context_sap,
398 continuable ? T : NIL);
400 undo_fake_foreign_function_call(context); /* blocks signals again */
402 arch_skip_instruction(context);
406 interrupt_handle_pending(os_context_t *context)
408 struct thread *thread;
409 struct interrupt_data *data;
411 FSHOW_SIGNAL((stderr, "/entering interrupt_handle_pending\n"));
413 check_blockables_blocked_or_lose();
414 thread=arch_os_get_current_thread();
415 data=thread->interrupt_data;
417 /* If pseudo_atomic_interrupted is set then the interrupt is going
418 * to be handled now, ergo it's safe to clear it. */
419 arch_clear_pseudo_atomic_interrupted(context);
421 if (SymbolValue(GC_INHIBIT,thread)==NIL) {
422 #ifdef LISP_FEATURE_SB_THREAD
423 if (SymbolValue(STOP_FOR_GC_PENDING,thread) != NIL) {
424 /* another thread has already initiated a gc, this attempt
425 * might as well be cancelled */
426 SetSymbolValue(GC_PENDING,NIL,thread);
427 SetSymbolValue(STOP_FOR_GC_PENDING,NIL,thread);
428 sig_stop_for_gc_handler(SIG_STOP_FOR_GC,NULL,context);
431 if (SymbolValue(GC_PENDING,thread) != NIL) {
432 /* GC_PENDING is cleared in SUB-GC, or if another thread
433 * is doing a gc already we will get a SIG_STOP_FOR_GC and
434 * that will clear it. */
435 interrupt_maybe_gc_int(0,NULL,context);
437 check_blockables_blocked_or_lose();
440 /* we may be here only to do the gc stuff, if interrupts are
441 * enabled run the pending handler */
442 if (!((SymbolValue(INTERRUPTS_ENABLED,thread) == NIL) ||
444 #if !defined(LISP_FEATURE_X86) && !defined(LISP_FEATURE_X86_64)
445 (!foreign_function_call_active) &&
447 arch_pseudo_atomic_atomic(context)))) {
449 /* There may be no pending handler, because it was only a gc
450 * that had to be executed or because pseudo atomic triggered
451 * twice for a single interrupt. For the interested reader,
452 * that may happen if an interrupt hits after the interrupted
453 * flag is cleared but before pseduo-atomic is set and a
454 * pseudo atomic is interrupted in that interrupt. */
455 if (data->pending_handler) {
457 /* If we're here as the result of a pseudo-atomic as opposed
458 * to WITHOUT-INTERRUPTS, then INTERRUPT_PENDING is already
459 * NIL, because maybe_defer_handler sets
460 * PSEUDO_ATOMIC_INTERRUPTED only if interrupts are enabled.*/
461 SetSymbolValue(INTERRUPT_PENDING, NIL,thread);
463 #ifndef LISP_FEATURE_WIN32
464 /* restore the saved signal mask from the original signal (the
465 * one that interrupted us during the critical section) into the
466 * os_context for the signal we're currently in the handler for.
467 * This should ensure that when we return from the handler the
468 * blocked signals are unblocked */
469 sigcopyset(os_context_sigmask_addr(context), &data->pending_mask);
471 sigemptyset(&data->pending_mask);
473 /* This will break on sparc linux: the deferred handler really wants
474 * to be called with a void_context */
475 run_deferred_handler(data,(void *)context);
481 * the two main signal handlers:
482 * interrupt_handle_now(..)
483 * maybe_now_maybe_later(..)
485 * to which we have added interrupt_handle_now_handler(..). Why?
486 * Well, mostly because the SPARC/Linux platform doesn't quite do
487 * signals the way we want them done. The third argument in the
488 * handler isn't filled in by the kernel properly, so we fix it up
489 * ourselves in the arch_os_get_context(..) function; however, we only
490 * want to do this when we first hit the handler, and not when
491 * interrupt_handle_now(..) is being called from some other handler
492 * (when the fixup will already have been done). -- CSR, 2002-07-23
496 interrupt_handle_now(int signal, siginfo_t *info, void *void_context)
498 os_context_t *context = (os_context_t*)void_context;
499 #if !defined(LISP_FEATURE_X86) && !defined(LISP_FEATURE_X86_64)
500 boolean were_in_lisp;
502 union interrupt_handler handler;
504 check_blockables_blocked_or_lose();
507 #ifndef LISP_FEATURE_WIN32
508 if (sigismember(&deferrable_sigset,signal))
509 check_interrupts_enabled_or_lose(context);
512 #if defined(LISP_FEATURE_LINUX) || defined(RESTORE_FP_CONTROL_FROM_CONTEXT)
513 /* Under Linux on some architectures, we appear to have to restore
514 the FPU control word from the context, as after the signal is
515 delivered we appear to have a null FPU control word. */
516 os_restore_fp_control(context);
520 handler = interrupt_handlers[signal];
522 if (ARE_SAME_HANDLER(handler.c, SIG_IGN)) {
526 #if !defined(LISP_FEATURE_X86) && !defined(LISP_FEATURE_X86_64)
527 were_in_lisp = !foreign_function_call_active;
531 fake_foreign_function_call(context);
534 FSHOW_SIGNAL((stderr,
535 "/entering interrupt_handle_now(%d, info, context)\n",
538 if (ARE_SAME_HANDLER(handler.c, SIG_DFL)) {
540 /* This can happen if someone tries to ignore or default one
541 * of the signals we need for runtime support, and the runtime
542 * support decides to pass on it. */
543 lose("no handler for signal %d in interrupt_handle_now(..)\n", signal);
545 } else if (lowtag_of(handler.lisp) == FUN_POINTER_LOWTAG) {
546 /* Once we've decided what to do about contexts in a
547 * return-elsewhere world (the original context will no longer
548 * be available; should we copy it or was nobody using it anyway?)
549 * then we should convert this to return-elsewhere */
551 /* CMUCL comment said "Allocate the SAPs while the interrupts
552 * are still disabled.". I (dan, 2003.08.21) assume this is
553 * because we're not in pseudoatomic and allocation shouldn't
554 * be interrupted. In which case it's no longer an issue as
555 * all our allocation from C now goes through a PA wrapper,
556 * but still, doesn't hurt.
558 * Yeah, but non-gencgc platforms don't really wrap allocation
559 * in PA. MG - 2005-08-29 */
561 lispobj info_sap,context_sap = alloc_sap(context);
562 info_sap = alloc_sap(info);
563 /* Leave deferrable signals blocked, the handler itself will
564 * allow signals again when it sees fit. */
565 #ifdef LISP_FEATURE_SB_THREAD
568 sigemptyset(&unblock);
569 sigaddset(&unblock, SIG_STOP_FOR_GC);
570 #ifdef SIG_RESUME_FROM_GC
571 sigaddset(&unblock, SIG_RESUME_FROM_GC);
573 thread_sigmask(SIG_UNBLOCK, &unblock, 0);
577 FSHOW_SIGNAL((stderr,"/calling Lisp-level handler\n"));
579 funcall3(handler.lisp,
585 FSHOW_SIGNAL((stderr,"/calling C-level handler\n"));
587 #ifndef LISP_FEATURE_WIN32
588 /* Allow signals again. */
589 thread_sigmask(SIG_SETMASK, os_context_sigmask_addr(context), 0);
592 (*handler.c)(signal, info, void_context);
595 #if !defined(LISP_FEATURE_X86) && !defined(LISP_FEATURE_X86_64)
599 undo_fake_foreign_function_call(context); /* block signals again */
602 FSHOW_SIGNAL((stderr,
603 "/returning from interrupt_handle_now(%d, info, context)\n",
607 /* This is called at the end of a critical section if the indications
608 * are that some signal was deferred during the section. Note that as
609 * far as C or the kernel is concerned we dealt with the signal
610 * already; we're just doing the Lisp-level processing now that we
613 run_deferred_handler(struct interrupt_data *data, void *v_context) {
614 /* The pending_handler may enable interrupts and then another
615 * interrupt may hit, overwrite interrupt_data, so reset the
616 * pending handler before calling it. Trust the handler to finish
617 * with the siginfo before enabling interrupts. */
618 void (*pending_handler) (int, siginfo_t*, void*)=data->pending_handler;
620 data->pending_handler=0;
621 (*pending_handler)(data->pending_signal,&(data->pending_info), v_context);
624 #ifndef LISP_FEATURE_WIN32
626 maybe_defer_handler(void *handler, struct interrupt_data *data,
627 int signal, siginfo_t *info, os_context_t *context)
629 struct thread *thread=arch_os_get_current_thread();
631 check_blockables_blocked_or_lose();
633 if (SymbolValue(INTERRUPT_PENDING,thread) != NIL)
634 lose("interrupt already pending\n");
635 /* If interrupts are disabled then INTERRUPT_PENDING is set and
636 * not PSEDUO_ATOMIC_INTERRUPTED. This is important for a pseudo
637 * atomic section inside a WITHOUT-INTERRUPTS.
639 if (SymbolValue(INTERRUPTS_ENABLED,thread) == NIL) {
640 store_signal_data_for_later(data,handler,signal,info,context);
641 SetSymbolValue(INTERRUPT_PENDING, T,thread);
642 FSHOW_SIGNAL((stderr,
643 "/maybe_defer_handler(%x,%d),thread=%lu: deferred\n",
644 (unsigned int)handler,signal,
645 (unsigned long)thread->os_thread));
648 /* a slightly confusing test. arch_pseudo_atomic_atomic() doesn't
649 * actually use its argument for anything on x86, so this branch
650 * may succeed even when context is null (gencgc alloc()) */
652 #if !defined(LISP_FEATURE_X86) && !defined(LISP_FEATURE_X86_64)
653 /* FIXME: this foreign_function_call_active test is dubious at
654 * best. If a foreign call is made in a pseudo atomic section
655 * (?) or more likely a pseudo atomic section is in a foreign
656 * call then an interrupt is executed immediately. Maybe it
657 * has to do with C code not maintaining pseudo atomic
658 * properly. MG - 2005-08-10 */
659 (!foreign_function_call_active) &&
661 arch_pseudo_atomic_atomic(context)) {
662 store_signal_data_for_later(data,handler,signal,info,context);
663 arch_set_pseudo_atomic_interrupted(context);
664 FSHOW_SIGNAL((stderr,
665 "/maybe_defer_handler(%x,%d),thread=%lu: deferred(PA)\n",
666 (unsigned int)handler,signal,
667 (unsigned long)thread->os_thread));
670 FSHOW_SIGNAL((stderr,
671 "/maybe_defer_handler(%x,%d),thread=%lu: not deferred\n",
672 (unsigned int)handler,signal,
673 (unsigned long)thread->os_thread));
678 store_signal_data_for_later (struct interrupt_data *data, void *handler,
680 siginfo_t *info, os_context_t *context)
682 if (data->pending_handler)
683 lose("tried to overwrite pending interrupt handler %x with %x\n",
684 data->pending_handler, handler);
686 lose("tried to defer null interrupt handler\n");
687 data->pending_handler = handler;
688 data->pending_signal = signal;
690 memcpy(&(data->pending_info), info, sizeof(siginfo_t));
692 FSHOW_SIGNAL((stderr, "/store_signal_data_for_later: signal: %d\n", signal));
695 /* the signal mask in the context (from before we were
696 * interrupted) is copied to be restored when
697 * run_deferred_handler happens. Then the usually-blocked
698 * signals are added to the mask in the context so that we are
699 * running with blocked signals when the handler returns */
700 sigcopyset(&(data->pending_mask),os_context_sigmask_addr(context));
701 sigaddset_deferrable(os_context_sigmask_addr(context));
706 maybe_now_maybe_later(int signal, siginfo_t *info, void *void_context)
708 os_context_t *context = arch_os_get_context(&void_context);
710 struct thread *thread;
711 struct interrupt_data *data;
713 thread=arch_os_get_current_thread();
714 data=thread->interrupt_data;
716 #if defined(LISP_FEATURE_LINUX) || defined(RESTORE_FP_CONTROL_FROM_CONTEXT)
717 os_restore_fp_control(context);
720 if(maybe_defer_handler(interrupt_handle_now,data,signal,info,context))
722 interrupt_handle_now(signal, info, context);
723 #ifdef LISP_FEATURE_DARWIN
724 /* Work around G5 bug */
725 DARWIN_FIX_CONTEXT(context);
730 low_level_interrupt_handle_now(int signal, siginfo_t *info, void *void_context)
732 os_context_t *context = (os_context_t*)void_context;
734 #if defined(LISP_FEATURE_LINUX) || defined(RESTORE_FP_CONTROL_FROM_CONTEXT)
735 os_restore_fp_control(context);
738 check_blockables_blocked_or_lose();
739 check_interrupts_enabled_or_lose(context);
740 interrupt_low_level_handlers[signal](signal, info, void_context);
741 #ifdef LISP_FEATURE_DARWIN
742 /* Work around G5 bug */
743 DARWIN_FIX_CONTEXT(context);
748 low_level_maybe_now_maybe_later(int signal, siginfo_t *info, void *void_context)
750 os_context_t *context = arch_os_get_context(&void_context);
751 struct thread *thread;
752 struct interrupt_data *data;
754 thread=arch_os_get_current_thread();
755 data=thread->interrupt_data;
757 #if defined(LISP_FEATURE_LINUX) || defined(RESTORE_FP_CONTROL_FROM_CONTEXT)
758 os_restore_fp_control(context);
761 if(maybe_defer_handler(low_level_interrupt_handle_now,data,
762 signal,info,context))
764 low_level_interrupt_handle_now(signal, info, context);
765 #ifdef LISP_FEATURE_DARWIN
766 /* Work around G5 bug */
767 DARWIN_FIX_CONTEXT(context);
772 #ifdef LISP_FEATURE_SB_THREAD
775 sig_stop_for_gc_handler(int signal, siginfo_t *info, void *void_context)
777 os_context_t *context = arch_os_get_context(&void_context);
779 struct thread *thread=arch_os_get_current_thread();
782 if ((arch_pseudo_atomic_atomic(context) ||
783 SymbolValue(GC_INHIBIT,thread) != NIL)) {
784 SetSymbolValue(STOP_FOR_GC_PENDING,T,thread);
785 if (SymbolValue(GC_INHIBIT,thread) == NIL)
786 arch_set_pseudo_atomic_interrupted(context);
787 FSHOW_SIGNAL((stderr,"thread=%lu sig_stop_for_gc deferred\n",
790 /* need the context stored so it can have registers scavenged */
791 fake_foreign_function_call(context);
793 sigfillset(&ss); /* Block everything. */
794 thread_sigmask(SIG_BLOCK,&ss,0);
796 if(thread->state!=STATE_RUNNING) {
797 lose("sig_stop_for_gc_handler: wrong thread state: %ld\n",
798 fixnum_value(thread->state));
800 thread->state=STATE_SUSPENDED;
801 FSHOW_SIGNAL((stderr,"thread=%lu suspended\n",thread->os_thread));
803 #if defined(SIG_RESUME_FROM_GC)
804 sigemptyset(&ss); sigaddset(&ss,SIG_RESUME_FROM_GC);
806 sigemptyset(&ss); sigaddset(&ss,SIG_STOP_FOR_GC);
809 /* It is possible to get SIGCONT (and probably other
810 * non-blockable signals) here. */
811 #ifdef SIG_RESUME_FROM_GC
814 do { sigwait(&ss, &sigret); }
815 while (sigret != SIG_RESUME_FROM_GC);
818 while (sigwaitinfo(&ss,0) != SIG_STOP_FOR_GC);
821 FSHOW_SIGNAL((stderr,"thread=%lu resumed\n",thread->os_thread));
822 if(thread->state!=STATE_RUNNING) {
823 lose("sig_stop_for_gc_handler: wrong thread state on wakeup: %ld\n",
824 fixnum_value(thread->state));
827 undo_fake_foreign_function_call(context);
833 interrupt_handle_now_handler(int signal, siginfo_t *info, void *void_context)
835 os_context_t *context = arch_os_get_context(&void_context);
836 interrupt_handle_now(signal, info, context);
837 #ifdef LISP_FEATURE_DARWIN
838 DARWIN_FIX_CONTEXT(context);
843 * stuff to detect and handle hitting the GC trigger
846 #ifndef LISP_FEATURE_GENCGC
847 /* since GENCGC has its own way to record trigger */
849 gc_trigger_hit(int signal, siginfo_t *info, os_context_t *context)
851 if (current_auto_gc_trigger == NULL)
854 void *badaddr=arch_get_bad_addr(signal,info,context);
855 return (badaddr >= (void *)current_auto_gc_trigger &&
856 badaddr <((void *)current_dynamic_space + dynamic_space_size));
861 /* manipulate the signal context and stack such that when the handler
862 * returns, it will call function instead of whatever it was doing
866 #if (defined(LISP_FEATURE_X86) || defined(LISP_FEATURE_X86_64))
867 extern int *context_eflags_addr(os_context_t *context);
870 extern lispobj call_into_lisp(lispobj fun, lispobj *args, int nargs);
871 extern void post_signal_tramp(void);
872 extern void call_into_lisp_tramp(void);
874 arrange_return_to_lisp_function(os_context_t *context, lispobj function)
876 #if !(defined(LISP_FEATURE_X86) || defined(LISP_FEATURE_X86_64))
877 void * fun=native_pointer(function);
878 void *code = &(((struct simple_fun *) fun)->code);
881 /* Build a stack frame showing `interrupted' so that the
882 * user's backtrace makes (as much) sense (as usual) */
884 /* FIXME: what about restoring fp state? */
885 /* FIXME: what about restoring errno? */
886 #ifdef LISP_FEATURE_X86
887 /* Suppose the existence of some function that saved all
888 * registers, called call_into_lisp, then restored GP registers and
889 * returned. It would look something like this:
897 pushl {address of function to call}
898 call 0x8058db0 <call_into_lisp>
905 * What we do here is set up the stack that call_into_lisp would
906 * expect to see if it had been called by this code, and frob the
907 * signal context so that signal return goes directly to call_into_lisp,
908 * and when that function (and the lisp function it invoked) returns,
909 * it returns to the second half of this imaginary function which
910 * restores all registers and returns to C
912 * For this to work, the latter part of the imaginary function
913 * must obviously exist in reality. That would be post_signal_tramp
916 u32 *sp=(u32 *)*os_context_register_addr(context,reg_ESP);
918 #if defined(LISP_FEATURE_DARWIN)
919 u32 *register_save_area = (u32 *)os_validate(0, 0x40);
921 FSHOW_SIGNAL((stderr, "/arrange_return_to_lisp_function: preparing to go to function %x, sp: %x\n", function, sp));
922 FSHOW_SIGNAL((stderr, "/arrange_return_to_lisp_function: context: %x, &context %x\n", context, &context));
924 /* 1. os_validate (malloc/mmap) register_save_block
925 * 2. copy register state into register_save_block
926 * 3. put a pointer to register_save_block in a register in the context
927 * 4. set the context's EIP to point to a trampoline which:
928 * a. builds the fake stack frame from the block
930 * c. calls the function
933 *register_save_area = *os_context_pc_addr(context);
934 *(register_save_area + 1) = function;
935 *(register_save_area + 2) = *os_context_register_addr(context,reg_EDI);
936 *(register_save_area + 3) = *os_context_register_addr(context,reg_ESI);
937 *(register_save_area + 4) = *os_context_register_addr(context,reg_EDX);
938 *(register_save_area + 5) = *os_context_register_addr(context,reg_ECX);
939 *(register_save_area + 6) = *os_context_register_addr(context,reg_EBX);
940 *(register_save_area + 7) = *os_context_register_addr(context,reg_EAX);
941 *(register_save_area + 8) = *context_eflags_addr(context);
943 *os_context_pc_addr(context) = call_into_lisp_tramp;
944 *os_context_register_addr(context,reg_ECX) = register_save_area;
947 /* return address for call_into_lisp: */
948 *(sp-15) = (u32)post_signal_tramp;
949 *(sp-14) = function; /* args for call_into_lisp : function*/
950 *(sp-13) = 0; /* arg array */
951 *(sp-12) = 0; /* no. args */
952 /* this order matches that used in POPAD */
953 *(sp-11)=*os_context_register_addr(context,reg_EDI);
954 *(sp-10)=*os_context_register_addr(context,reg_ESI);
956 *(sp-9)=*os_context_register_addr(context,reg_ESP)-8;
957 /* POPAD ignores the value of ESP: */
959 *(sp-7)=*os_context_register_addr(context,reg_EBX);
961 *(sp-6)=*os_context_register_addr(context,reg_EDX);
962 *(sp-5)=*os_context_register_addr(context,reg_ECX);
963 *(sp-4)=*os_context_register_addr(context,reg_EAX);
964 *(sp-3)=*context_eflags_addr(context);
965 *(sp-2)=*os_context_register_addr(context,reg_EBP);
966 *(sp-1)=*os_context_pc_addr(context);
970 #elif defined(LISP_FEATURE_X86_64)
971 u64 *sp=(u64 *)*os_context_register_addr(context,reg_RSP);
973 /* return address for call_into_lisp: */
974 *(sp-18) = (u64)post_signal_tramp;
976 *(sp-17)=*os_context_register_addr(context,reg_R15);
977 *(sp-16)=*os_context_register_addr(context,reg_R14);
978 *(sp-15)=*os_context_register_addr(context,reg_R13);
979 *(sp-14)=*os_context_register_addr(context,reg_R12);
980 *(sp-13)=*os_context_register_addr(context,reg_R11);
981 *(sp-12)=*os_context_register_addr(context,reg_R10);
982 *(sp-11)=*os_context_register_addr(context,reg_R9);
983 *(sp-10)=*os_context_register_addr(context,reg_R8);
984 *(sp-9)=*os_context_register_addr(context,reg_RDI);
985 *(sp-8)=*os_context_register_addr(context,reg_RSI);
986 /* skip RBP and RSP */
987 *(sp-7)=*os_context_register_addr(context,reg_RBX);
988 *(sp-6)=*os_context_register_addr(context,reg_RDX);
989 *(sp-5)=*os_context_register_addr(context,reg_RCX);
990 *(sp-4)=*os_context_register_addr(context,reg_RAX);
991 *(sp-3)=*context_eflags_addr(context);
992 *(sp-2)=*os_context_register_addr(context,reg_RBP);
993 *(sp-1)=*os_context_pc_addr(context);
995 *os_context_register_addr(context,reg_RDI) =
996 (os_context_register_t)function; /* function */
997 *os_context_register_addr(context,reg_RSI) = 0; /* arg. array */
998 *os_context_register_addr(context,reg_RDX) = 0; /* no. args */
1000 struct thread *th=arch_os_get_current_thread();
1001 build_fake_control_stack_frames(th,context);
1004 #ifdef LISP_FEATURE_X86
1006 #if !defined(LISP_FEATURE_DARWIN)
1007 *os_context_pc_addr(context) = (os_context_register_t)call_into_lisp;
1008 *os_context_register_addr(context,reg_ECX) = 0;
1009 *os_context_register_addr(context,reg_EBP) = (os_context_register_t)(sp-2);
1011 *os_context_register_addr(context,reg_UESP) =
1012 (os_context_register_t)(sp-15);
1014 *os_context_register_addr(context,reg_ESP) = (os_context_register_t)(sp-15);
1015 #endif /* __NETBSD__ */
1016 #endif /* LISP_FEATURE_DARWIN */
1018 #elif defined(LISP_FEATURE_X86_64)
1019 *os_context_pc_addr(context) = (os_context_register_t)call_into_lisp;
1020 *os_context_register_addr(context,reg_RCX) = 0;
1021 *os_context_register_addr(context,reg_RBP) = (os_context_register_t)(sp-2);
1022 *os_context_register_addr(context,reg_RSP) = (os_context_register_t)(sp-18);
1024 /* this much of the calling convention is common to all
1026 *os_context_pc_addr(context) = (os_context_register_t)(unsigned long)code;
1027 *os_context_register_addr(context,reg_NARGS) = 0;
1028 *os_context_register_addr(context,reg_LIP) =
1029 (os_context_register_t)(unsigned long)code;
1030 *os_context_register_addr(context,reg_CFP) =
1031 (os_context_register_t)(unsigned long)current_control_frame_pointer;
1033 #ifdef ARCH_HAS_NPC_REGISTER
1034 *os_context_npc_addr(context) =
1035 4 + *os_context_pc_addr(context);
1037 #ifdef LISP_FEATURE_SPARC
1038 *os_context_register_addr(context,reg_CODE) =
1039 (os_context_register_t)(fun + FUN_POINTER_LOWTAG);
1043 #ifdef LISP_FEATURE_SB_THREAD
1045 /* FIXME: this function can go away when all lisp handlers are invoked
1046 * via arrange_return_to_lisp_function. */
1048 interrupt_thread_handler(int num, siginfo_t *info, void *v_context)
1050 os_context_t *context = (os_context_t*)arch_os_get_context(&v_context);
1052 /* let the handler enable interrupts again when it sees fit */
1053 sigaddset_deferrable(os_context_sigmask_addr(context));
1054 arrange_return_to_lisp_function(context, SymbolFunction(RUN_INTERRUPTION));
1059 /* KLUDGE: Theoretically the approach we use for undefined alien
1060 * variables should work for functions as well, but on PPC/Darwin
1061 * we get bus error at bogus addresses instead, hence this workaround,
1062 * that has the added benefit of automatically discriminating between
1063 * functions and variables.
1066 undefined_alien_function() {
1067 funcall0(SymbolFunction(UNDEFINED_ALIEN_FUNCTION_ERROR));
1071 handle_guard_page_triggered(os_context_t *context,os_vm_address_t addr)
1073 struct thread *th=arch_os_get_current_thread();
1075 /* note the os_context hackery here. When the signal handler returns,
1076 * it won't go back to what it was doing ... */
1077 if(addr >= CONTROL_STACK_GUARD_PAGE(th) &&
1078 addr < CONTROL_STACK_GUARD_PAGE(th) + os_vm_page_size) {
1079 /* We hit the end of the control stack: disable guard page
1080 * protection so the error handler has some headroom, protect the
1081 * previous page so that we can catch returns from the guard page
1082 * and restore it. */
1083 protect_control_stack_guard_page(0);
1084 protect_control_stack_return_guard_page(1);
1086 arrange_return_to_lisp_function
1087 (context, SymbolFunction(CONTROL_STACK_EXHAUSTED_ERROR));
1090 else if(addr >= CONTROL_STACK_RETURN_GUARD_PAGE(th) &&
1091 addr < CONTROL_STACK_RETURN_GUARD_PAGE(th) + os_vm_page_size) {
1092 /* We're returning from the guard page: reprotect it, and
1093 * unprotect this one. This works even if we somehow missed
1094 * the return-guard-page, and hit it on our way to new
1095 * exhaustion instead. */
1096 protect_control_stack_guard_page(1);
1097 protect_control_stack_return_guard_page(0);
1100 else if (addr >= undefined_alien_address &&
1101 addr < undefined_alien_address + os_vm_page_size) {
1102 arrange_return_to_lisp_function
1103 (context, SymbolFunction(UNDEFINED_ALIEN_VARIABLE_ERROR));
1109 #ifndef LISP_FEATURE_GENCGC
1110 /* This function gets called from the SIGSEGV (for e.g. Linux, NetBSD, &
1111 * OpenBSD) or SIGBUS (for e.g. FreeBSD) handler. Here we check
1112 * whether the signal was due to treading on the mprotect()ed zone -
1113 * and if so, arrange for a GC to happen. */
1114 extern unsigned long bytes_consed_between_gcs; /* gc-common.c */
1117 interrupt_maybe_gc(int signal, siginfo_t *info, void *void_context)
1119 os_context_t *context=(os_context_t *) void_context;
1121 if(!foreign_function_call_active && gc_trigger_hit(signal, info, context)){
1122 struct thread *thread=arch_os_get_current_thread();
1123 clear_auto_gc_trigger();
1124 /* Don't flood the system with interrupts if the need to gc is
1125 * already noted. This can happen for example when SUB-GC
1126 * allocates or after a gc triggered in a WITHOUT-GCING. */
1127 if (SymbolValue(GC_PENDING,thread) == NIL) {
1128 if (SymbolValue(GC_INHIBIT,thread) == NIL) {
1129 if (arch_pseudo_atomic_atomic(context)) {
1130 /* set things up so that GC happens when we finish
1132 SetSymbolValue(GC_PENDING,T,thread);
1133 arch_set_pseudo_atomic_interrupted(context);
1135 interrupt_maybe_gc_int(signal,info,void_context);
1138 SetSymbolValue(GC_PENDING,T,thread);
1148 /* this is also used by gencgc, in alloc() */
1150 interrupt_maybe_gc_int(int signal, siginfo_t *info, void *void_context)
1152 os_context_t *context=(os_context_t *) void_context;
1153 #ifndef LISP_FEATURE_WIN32
1154 struct thread *thread=arch_os_get_current_thread();
1157 fake_foreign_function_call(context);
1159 /* SUB-GC may return without GCing if *GC-INHIBIT* is set, in
1160 * which case we will be running with no gc trigger barrier
1161 * thing for a while. But it shouldn't be long until the end
1164 * FIXME: It would be good to protect the end of dynamic space
1165 * and signal a storage condition from there.
1168 /* Restore the signal mask from the interrupted context before
1169 * calling into Lisp if interrupts are enabled. Why not always?
1171 * Suppose there is a WITHOUT-INTERRUPTS block far, far out. If an
1172 * interrupt hits while in SUB-GC, it is deferred and the
1173 * os_context_sigmask of that interrupt is set to block further
1174 * deferrable interrupts (until the first one is
1175 * handled). Unfortunately, that context refers to this place and
1176 * when we return from here the signals will not be blocked.
1178 * A kludgy alternative is to propagate the sigmask change to the
1181 #ifndef LISP_FEATURE_WIN32
1182 if(SymbolValue(INTERRUPTS_ENABLED,thread)!=NIL) {
1183 thread_sigmask(SIG_SETMASK, os_context_sigmask_addr(context), 0);
1184 check_gc_signals_unblocked_or_lose();
1187 unblock_gc_signals();
1189 funcall0(SymbolFunction(SUB_GC));
1190 undo_fake_foreign_function_call(context);
1196 * noise to install handlers
1199 #ifndef LISP_FEATURE_WIN32
1200 /* In Linux 2.4 synchronous signals (sigtrap & co) can be delivered if
1201 * they are blocked, in Linux 2.6 the default handler is invoked
1202 * instead that usually coredumps. One might hastily think that adding
1203 * SA_NODEFER helps, but until ~2.6.13 if SA_NODEFER is specified then
1204 * the whole sa_mask is ignored and instead of not adding the signal
1205 * in question to the mask. That means if it's not blockable the
1206 * signal must be unblocked at the beginning of signal handlers.
1208 * It turns out that NetBSD's SA_NODEFER doesn't DTRT in a different
1209 * way: if SA_NODEFER is set and the signal is in sa_mask, the signal
1210 * will be unblocked in the sigmask during the signal handler. -- RMK
1213 static volatile int sigaction_nodefer_works = -1;
1215 #define SA_NODEFER_TEST_BLOCK_SIGNAL SIGABRT
1216 #define SA_NODEFER_TEST_KILL_SIGNAL SIGUSR1
1219 sigaction_nodefer_test_handler(int signal, siginfo_t *info, void *void_context)
1221 sigset_t empty, current;
1223 sigemptyset(&empty);
1224 thread_sigmask(SIG_BLOCK, &empty, ¤t);
1225 /* There should be exactly two blocked signals: the two we added
1226 * to sa_mask when setting up the handler. NetBSD doesn't block
1227 * the signal we're handling when SA_NODEFER is set; Linux before
1228 * 2.6.13 or so also doesn't block the other signal when
1229 * SA_NODEFER is set. */
1230 for(i = 1; i < NSIG; i++)
1231 if (sigismember(¤t, i) !=
1232 (((i == SA_NODEFER_TEST_BLOCK_SIGNAL) || (i == signal)) ? 1 : 0)) {
1233 FSHOW_SIGNAL((stderr, "SA_NODEFER doesn't work, signal %d\n", i));
1234 sigaction_nodefer_works = 0;
1236 if (sigaction_nodefer_works == -1)
1237 sigaction_nodefer_works = 1;
1241 see_if_sigaction_nodefer_works()
1243 struct sigaction sa, old_sa;
1245 sa.sa_flags = SA_SIGINFO | SA_NODEFER;
1246 sa.sa_sigaction = sigaction_nodefer_test_handler;
1247 sigemptyset(&sa.sa_mask);
1248 sigaddset(&sa.sa_mask, SA_NODEFER_TEST_BLOCK_SIGNAL);
1249 sigaddset(&sa.sa_mask, SA_NODEFER_TEST_KILL_SIGNAL);
1250 sigaction(SA_NODEFER_TEST_KILL_SIGNAL, &sa, &old_sa);
1251 /* Make sure no signals are blocked. */
1254 sigemptyset(&empty);
1255 thread_sigmask(SIG_SETMASK, &empty, 0);
1257 kill(getpid(), SA_NODEFER_TEST_KILL_SIGNAL);
1258 while (sigaction_nodefer_works == -1);
1259 sigaction(SA_NODEFER_TEST_KILL_SIGNAL, &old_sa, NULL);
1262 #undef SA_NODEFER_TEST_BLOCK_SIGNAL
1263 #undef SA_NODEFER_TEST_KILL_SIGNAL
1266 unblock_me_trampoline(int signal, siginfo_t *info, void *void_context)
1270 sigemptyset(&unblock);
1271 sigaddset(&unblock, signal);
1272 thread_sigmask(SIG_UNBLOCK, &unblock, 0);
1273 interrupt_handle_now_handler(signal, info, void_context);
1277 low_level_unblock_me_trampoline(int signal, siginfo_t *info, void *void_context)
1281 sigemptyset(&unblock);
1282 sigaddset(&unblock, signal);
1283 thread_sigmask(SIG_UNBLOCK, &unblock, 0);
1284 (*interrupt_low_level_handlers[signal])(signal, info, void_context);
1288 undoably_install_low_level_interrupt_handler (int signal,
1293 struct sigaction sa;
1295 if (0 > signal || signal >= NSIG) {
1296 lose("bad signal number %d\n", signal);
1299 if (ARE_SAME_HANDLER(handler, SIG_DFL))
1300 sa.sa_sigaction = handler;
1301 else if (sigismember(&deferrable_sigset,signal))
1302 sa.sa_sigaction = low_level_maybe_now_maybe_later;
1303 /* The use of a trampoline appears to break the
1304 arch_os_get_context() workaround for SPARC/Linux. For now,
1305 don't use the trampoline (and so be vulnerable to the problems
1306 that SA_NODEFER is meant to solve. */
1307 #if !(defined(LISP_FEATURE_SPARC) && defined(LISP_FEATURE_LINUX))
1308 else if (!sigaction_nodefer_works &&
1309 !sigismember(&blockable_sigset, signal))
1310 sa.sa_sigaction = low_level_unblock_me_trampoline;
1313 sa.sa_sigaction = handler;
1315 sigcopyset(&sa.sa_mask, &blockable_sigset);
1316 sa.sa_flags = SA_SIGINFO | SA_RESTART
1317 | (sigaction_nodefer_works ? SA_NODEFER : 0);
1318 #ifdef LISP_FEATURE_C_STACK_IS_CONTROL_STACK
1319 if((signal==SIG_MEMORY_FAULT)
1320 #ifdef SIG_MEMORY_FAULT2
1321 || (signal==SIG_MEMORY_FAULT2)
1323 #ifdef SIG_INTERRUPT_THREAD
1324 || (signal==SIG_INTERRUPT_THREAD)
1327 sa.sa_flags |= SA_ONSTACK;
1330 sigaction(signal, &sa, NULL);
1331 interrupt_low_level_handlers[signal] =
1332 (ARE_SAME_HANDLER(handler, SIG_DFL) ? 0 : handler);
1336 /* This is called from Lisp. */
1338 install_handler(int signal, void handler(int, siginfo_t*, void*))
1340 #ifndef LISP_FEATURE_WIN32
1341 struct sigaction sa;
1343 union interrupt_handler oldhandler;
1345 FSHOW((stderr, "/entering POSIX install_handler(%d, ..)\n", signal));
1348 sigaddset(&new, signal);
1349 thread_sigmask(SIG_BLOCK, &new, &old);
1351 FSHOW((stderr, "/interrupt_low_level_handlers[signal]=%x\n",
1352 (unsigned int)interrupt_low_level_handlers[signal]));
1353 if (interrupt_low_level_handlers[signal]==0) {
1354 if (ARE_SAME_HANDLER(handler, SIG_DFL) ||
1355 ARE_SAME_HANDLER(handler, SIG_IGN))
1356 sa.sa_sigaction = handler;
1357 else if (sigismember(&deferrable_sigset, signal))
1358 sa.sa_sigaction = maybe_now_maybe_later;
1359 else if (!sigaction_nodefer_works &&
1360 !sigismember(&blockable_sigset, signal))
1361 sa.sa_sigaction = unblock_me_trampoline;
1363 sa.sa_sigaction = interrupt_handle_now_handler;
1365 sigcopyset(&sa.sa_mask, &blockable_sigset);
1366 sa.sa_flags = SA_SIGINFO | SA_RESTART |
1367 (sigaction_nodefer_works ? SA_NODEFER : 0);
1368 sigaction(signal, &sa, NULL);
1371 oldhandler = interrupt_handlers[signal];
1372 interrupt_handlers[signal].c = handler;
1374 thread_sigmask(SIG_SETMASK, &old, 0);
1376 FSHOW((stderr, "/leaving POSIX install_handler(%d, ..)\n", signal));
1378 return (unsigned long)oldhandler.lisp;
1380 /* Probably-wrong Win32 hack */
1388 #ifndef LISP_FEATURE_WIN32
1390 SHOW("entering interrupt_init()");
1391 see_if_sigaction_nodefer_works();
1392 sigemptyset(&deferrable_sigset);
1393 sigemptyset(&blockable_sigset);
1394 sigaddset_deferrable(&deferrable_sigset);
1395 sigaddset_blockable(&blockable_sigset);
1397 /* Set up high level handler information. */
1398 for (i = 0; i < NSIG; i++) {
1399 interrupt_handlers[i].c =
1400 /* (The cast here blasts away the distinction between
1401 * SA_SIGACTION-style three-argument handlers and
1402 * signal(..)-style one-argument handlers, which is OK
1403 * because it works to call the 1-argument form where the
1404 * 3-argument form is expected.) */
1405 (void (*)(int, siginfo_t*, void*))SIG_DFL;
1408 SHOW("returning from interrupt_init()");
1412 #ifndef LISP_FEATURE_WIN32
1414 siginfo_code(siginfo_t *info)
1416 return info->si_code;
1418 os_vm_address_t current_memory_fault_address;
1421 lisp_memory_fault_error(os_context_t *context, os_vm_address_t addr)
1423 /* FIXME: This is lossy: if we get another memory fault (eg. from
1424 * another thread) before lisp has read this, we the information.
1425 * However, since this is mostly informative, we'll live with that for
1426 * now -- some address is better then no address in this case.
1428 current_memory_fault_address = addr;
1429 arrange_return_to_lisp_function(context, SymbolFunction(MEMORY_FAULT_ERROR));
1433 /* Common logic far trapping instructions. How we actually handle each
1434 * case is highly architecture dependant, but the overall shape is
1437 maybe_handle_trap(os_context_t *context, int trap)
1440 case trap_PendingInterrupt:
1441 FSHOW((stderr, "/<trap pending interrupt>\n"));
1442 arch_skip_instruction(context);
1443 interrupt_handle_pending(context);
1447 FSHOW((stderr, "/<trap error/cerror %d>\n", trap));
1448 interrupt_internal_error(context, trap==trap_Cerror);
1450 case trap_Breakpoint:
1451 arch_handle_breakpoint(context);
1453 case trap_FunEndBreakpoint:
1454 arch_handle_fun_end_breakpoint(context);
1456 #ifdef trap_AfterBreakpoint
1457 case trap_AfterBreakpoint:
1458 arch_handle_after_breakpoint(context);
1461 #ifdef trap_SingleStepAround
1462 case trap_SingleStepAround:
1463 case trap_SingleStepBefore:
1464 arch_handle_single_step_trap(context, trap);
1468 fake_foreign_function_call(context);
1469 lose("%%PRIMITIVE HALT called; the party is over.\n");
1471 FSHOW((stderr,"/[C--trap default %d %d %x]\n",
1472 signal, trap, context));