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 /* When we catch an internal error, should we pass it back to Lisp to
72 * be handled in a high-level way? (Early in cold init, the answer is
73 * 'no', because Lisp is still too brain-dead to handle anything.
74 * After sufficient initialization has been completed, the answer
76 boolean internal_errors_enabled = 0;
78 #ifndef LISP_FEATURE_WIN32
80 void (*interrupt_low_level_handlers[NSIG]) (int, siginfo_t*, os_context_t*);
82 union interrupt_handler interrupt_handlers[NSIG];
84 /* Under Linux on some architectures, we appear to have to restore the
85 * FPU control word from the context, as after the signal is delivered
86 * we appear to have a null FPU control word. */
87 #if defined(RESTORE_FP_CONTROL_FROM_CONTEXT)
88 #define RESTORE_FP_CONTROL_WORD(context,void_context) \
89 os_context_t *context = arch_os_get_context(&void_context); \
90 os_restore_fp_control(context);
92 #define RESTORE_FP_CONTROL_WORD(context,void_context) \
93 os_context_t *context = arch_os_get_context(&void_context);
96 /* Foreign code may want to start some threads on its own.
97 * Non-targetted, truly asynchronous signals can be delivered to
98 * basically any thread, but invoking Lisp handlers in such foregign
99 * threads is really bad, so let's resignal it.
101 * This should at least bring attention to the problem, but it cannot
102 * work for SIGSEGV and similar. It is good enough for timers, and
103 * maybe all deferrables. */
105 #ifdef LISP_FEATURE_SB_THREAD
107 add_handled_signals(sigset_t *sigset)
110 for(i = 1; i < NSIG; i++) {
111 if (!(ARE_SAME_HANDLER(interrupt_low_level_handlers[i], SIG_DFL)) ||
112 !(ARE_SAME_HANDLER(interrupt_handlers[i].c, SIG_DFL))) {
113 sigaddset(sigset, i);
118 void block_signals(sigset_t *what, sigset_t *where, sigset_t *old);
122 maybe_resignal_to_lisp_thread(int signal, os_context_t *context)
124 #ifdef LISP_FEATURE_SB_THREAD
125 if (!pthread_getspecific(lisp_thread)) {
126 if (!(sigismember(&deferrable_sigset,signal))) {
127 corruption_warning_and_maybe_lose
128 ("Received signal %d in non-lisp thread %lu, resignalling to a lisp thread.",
134 sigemptyset(&sigset);
135 add_handled_signals(&sigset);
136 block_signals(&sigset, 0, 0);
137 block_signals(&sigset, os_context_sigmask_addr(context), 0);
138 kill(getpid(), signal);
146 /* These are to be used in signal handlers. Currently all handlers are
147 * called from one of:
149 * interrupt_handle_now_handler
150 * maybe_now_maybe_later
151 * unblock_me_trampoline
152 * low_level_handle_now_handler
153 * low_level_maybe_now_maybe_later
154 * low_level_unblock_me_trampoline
156 * This gives us a single point of control (or six) over errno, fp
157 * control word, and fixing up signal context on sparc.
159 * The SPARC/Linux platform doesn't quite do signals the way we want
160 * them done. The third argument in the handler isn't filled in by the
161 * kernel properly, so we fix it up ourselves in the
162 * arch_os_get_context(..) function. -- CSR, 2002-07-23
164 #define SAVE_ERRNO(signal,context,void_context) \
166 int _saved_errno = errno; \
167 RESTORE_FP_CONTROL_WORD(context,void_context); \
168 if (!maybe_resignal_to_lisp_thread(signal, context)) \
171 #define RESTORE_ERRNO \
173 errno = _saved_errno; \
176 static void run_deferred_handler(struct interrupt_data *data,
177 os_context_t *context);
178 #ifndef LISP_FEATURE_WIN32
179 static void store_signal_data_for_later (struct interrupt_data *data,
180 void *handler, int signal,
182 os_context_t *context);
185 /* Generic signal related utilities. */
188 get_current_sigmask(sigset_t *sigset)
190 /* Get the current sigmask, by blocking the empty set. */
191 thread_sigmask(SIG_BLOCK, 0, sigset);
195 block_signals(sigset_t *what, sigset_t *where, sigset_t *old)
200 sigcopyset(old, where);
201 for(i = 1; i < NSIG; i++) {
202 if (sigismember(what, i))
206 thread_sigmask(SIG_BLOCK, what, old);
211 unblock_signals(sigset_t *what, sigset_t *where, sigset_t *old)
216 sigcopyset(old, where);
217 for(i = 1; i < NSIG; i++) {
218 if (sigismember(what, i))
222 thread_sigmask(SIG_UNBLOCK, what, old);
227 print_sigset(sigset_t *sigset)
230 for(i = 1; i < NSIG; i++) {
231 if (sigismember(sigset, i))
232 fprintf(stderr, "Signal %d masked\n", i);
236 /* Return 1 is all signals is sigset2 are masked in sigset, return 0
237 * if all re unmasked else die. Passing NULL for sigset is a shorthand
238 * for the current sigmask. */
240 all_signals_blocked_p(sigset_t *sigset, sigset_t *sigset2,
243 #if !defined(LISP_FEATURE_WIN32)
245 boolean has_blocked = 0, has_unblocked = 0;
248 get_current_sigmask(¤t);
251 for(i = 1; i < NSIG; i++) {
252 if (sigismember(sigset2, i)) {
253 if (sigismember(sigset, i))
259 if (has_blocked && has_unblocked) {
260 print_sigset(sigset);
261 lose("some %s signals blocked, some unblocked\n", name);
271 /* Deferrables, blockables, gc signals. */
274 sigaddset_deferrable(sigset_t *s)
276 sigaddset(s, SIGHUP);
277 sigaddset(s, SIGINT);
278 sigaddset(s, SIGTERM);
279 sigaddset(s, SIGQUIT);
280 sigaddset(s, SIGPIPE);
281 sigaddset(s, SIGALRM);
282 sigaddset(s, SIGURG);
283 sigaddset(s, SIGTSTP);
284 sigaddset(s, SIGCHLD);
286 #ifndef LISP_FEATURE_HPUX
287 sigaddset(s, SIGXCPU);
288 sigaddset(s, SIGXFSZ);
290 sigaddset(s, SIGVTALRM);
291 sigaddset(s, SIGPROF);
292 sigaddset(s, SIGWINCH);
296 sigaddset_blockable(sigset_t *sigset)
298 sigaddset_deferrable(sigset);
299 sigaddset_gc(sigset);
303 sigaddset_gc(sigset_t *sigset)
305 #ifdef THREADS_USING_GCSIGNAL
306 sigaddset(sigset,SIG_STOP_FOR_GC);
310 /* initialized in interrupt_init */
311 sigset_t deferrable_sigset;
312 sigset_t blockable_sigset;
317 #if !defined(LISP_FEATURE_WIN32)
319 deferrables_blocked_p(sigset_t *sigset)
321 return all_signals_blocked_p(sigset, &deferrable_sigset, "deferrable");
326 check_deferrables_unblocked_or_lose(sigset_t *sigset)
328 #if !defined(LISP_FEATURE_WIN32)
329 if (deferrables_blocked_p(sigset))
330 lose("deferrables blocked\n");
335 check_deferrables_blocked_or_lose(sigset_t *sigset)
337 #if !defined(LISP_FEATURE_WIN32)
338 if (!deferrables_blocked_p(sigset))
339 lose("deferrables unblocked\n");
343 #if !defined(LISP_FEATURE_WIN32)
345 blockables_blocked_p(sigset_t *sigset)
347 return all_signals_blocked_p(sigset, &blockable_sigset, "blockable");
352 check_blockables_unblocked_or_lose(sigset_t *sigset)
354 #if !defined(LISP_FEATURE_WIN32)
355 if (blockables_blocked_p(sigset))
356 lose("blockables blocked\n");
361 check_blockables_blocked_or_lose(sigset_t *sigset)
363 #if !defined(LISP_FEATURE_WIN32)
364 if (!blockables_blocked_p(sigset))
365 lose("blockables unblocked\n");
369 #ifndef LISP_FEATURE_SB_SAFEPOINT
370 #if !defined(LISP_FEATURE_WIN32)
372 gc_signals_blocked_p(sigset_t *sigset)
374 return all_signals_blocked_p(sigset, &gc_sigset, "gc");
379 check_gc_signals_unblocked_or_lose(sigset_t *sigset)
381 #if !defined(LISP_FEATURE_WIN32)
382 if (gc_signals_blocked_p(sigset))
383 lose("gc signals blocked\n");
388 check_gc_signals_blocked_or_lose(sigset_t *sigset)
390 #if !defined(LISP_FEATURE_WIN32)
391 if (!gc_signals_blocked_p(sigset))
392 lose("gc signals unblocked\n");
398 block_deferrable_signals(sigset_t *where, sigset_t *old)
400 #ifndef LISP_FEATURE_WIN32
401 block_signals(&deferrable_sigset, where, old);
406 block_blockable_signals(sigset_t *where, sigset_t *old)
408 #ifndef LISP_FEATURE_WIN32
409 block_signals(&blockable_sigset, where, old);
413 #ifndef LISP_FEATURE_SB_SAFEPOINT
415 block_gc_signals(sigset_t *where, sigset_t *old)
417 #ifndef LISP_FEATURE_WIN32
418 block_signals(&gc_sigset, where, old);
424 unblock_deferrable_signals(sigset_t *where, sigset_t *old)
426 #ifndef LISP_FEATURE_WIN32
427 if (interrupt_handler_pending_p())
428 lose("unblock_deferrable_signals: losing proposition\n");
429 #ifndef LISP_FEATURE_SB_SAFEPOINT
430 check_gc_signals_unblocked_or_lose(where);
432 unblock_signals(&deferrable_sigset, where, old);
437 unblock_blockable_signals(sigset_t *where, sigset_t *old)
439 #ifndef LISP_FEATURE_WIN32
440 unblock_signals(&blockable_sigset, where, old);
444 #ifndef LISP_FEATURE_SB_SAFEPOINT
446 unblock_gc_signals(sigset_t *where, sigset_t *old)
448 #ifndef LISP_FEATURE_WIN32
449 unblock_signals(&gc_sigset, where, old);
455 unblock_signals_in_context_and_maybe_warn(os_context_t *context)
457 #ifndef LISP_FEATURE_WIN32
458 sigset_t *sigset = os_context_sigmask_addr(context);
459 #ifndef LISP_FEATURE_SB_SAFEPOINT
460 if (all_signals_blocked_p(sigset, &gc_sigset, "gc")) {
461 corruption_warning_and_maybe_lose(
462 "Enabling blocked gc signals to allow returning to Lisp without risking\n\
463 gc deadlocks. Since GC signals are only blocked in signal handlers when \n\
464 they are not safe to interrupt at all, this is a pretty severe occurrence.\n");
465 unblock_gc_signals(sigset, 0);
468 if (!interrupt_handler_pending_p()) {
469 unblock_deferrable_signals(sigset, 0);
476 check_interrupts_enabled_or_lose(os_context_t *context)
478 struct thread *thread=arch_os_get_current_thread();
479 if (SymbolValue(INTERRUPTS_ENABLED,thread) == NIL)
480 lose("interrupts not enabled\n");
481 if (arch_pseudo_atomic_atomic(context))
482 lose ("in pseudo atomic section\n");
485 /* Save sigset (or the current sigmask if 0) if there is no pending
486 * handler, because that means that deferabbles are already blocked.
487 * The purpose is to avoid losing the pending gc signal if a
488 * deferrable interrupt async unwinds between clearing the pseudo
489 * atomic and trapping to GC.*/
490 #ifndef LISP_FEATURE_SB_SAFEPOINT
492 maybe_save_gc_mask_and_block_deferrables(sigset_t *sigset)
494 #ifndef LISP_FEATURE_WIN32
495 struct thread *thread = arch_os_get_current_thread();
496 struct interrupt_data *data = thread->interrupt_data;
498 /* Obviously, this function is called when signals may not be
499 * blocked. Let's make sure we are not interrupted. */
500 block_blockable_signals(0, &oldset);
501 #ifndef LISP_FEATURE_SB_THREAD
502 /* With threads a SIG_STOP_FOR_GC and a normal GC may also want to
504 if (data->gc_blocked_deferrables)
505 lose("gc_blocked_deferrables already true\n");
507 if ((!data->pending_handler) &&
508 (!data->gc_blocked_deferrables)) {
509 FSHOW_SIGNAL((stderr,"/setting gc_blocked_deferrables\n"));
510 data->gc_blocked_deferrables = 1;
512 /* This is the sigmask of some context. */
513 sigcopyset(&data->pending_mask, sigset);
514 sigaddset_deferrable(sigset);
515 thread_sigmask(SIG_SETMASK,&oldset,0);
518 /* Operating on the current sigmask. Save oldset and
519 * unblock gc signals. In the end, this is equivalent to
520 * blocking the deferrables. */
521 sigcopyset(&data->pending_mask, &oldset);
522 thread_sigmask(SIG_UNBLOCK, &gc_sigset, 0);
526 thread_sigmask(SIG_SETMASK,&oldset,0);
531 /* Are we leaving WITH-GCING and already running with interrupts
532 * enabled, without the protection of *GC-INHIBIT* T and there is gc
533 * (or stop for gc) pending, but we haven't trapped yet? */
535 in_leaving_without_gcing_race_p(struct thread *thread)
537 return ((SymbolValue(IN_WITHOUT_GCING,thread) != NIL) &&
538 (SymbolValue(INTERRUPTS_ENABLED,thread) != NIL) &&
539 (SymbolValue(GC_INHIBIT,thread) == NIL) &&
540 ((SymbolValue(GC_PENDING,thread) != NIL)
541 #if defined(LISP_FEATURE_SB_THREAD)
542 || (SymbolValue(STOP_FOR_GC_PENDING,thread) != NIL)
547 /* Check our baroque invariants. */
549 check_interrupt_context_or_lose(os_context_t *context)
551 #ifndef LISP_FEATURE_WIN32
552 struct thread *thread = arch_os_get_current_thread();
553 struct interrupt_data *data = thread->interrupt_data;
554 int interrupt_deferred_p = (data->pending_handler != 0);
555 int interrupt_pending = (SymbolValue(INTERRUPT_PENDING,thread) != NIL);
556 sigset_t *sigset = os_context_sigmask_addr(context);
557 /* On PPC pseudo_atomic_interrupted is cleared when coming out of
558 * handle_allocation_trap. */
559 #if defined(LISP_FEATURE_GENCGC) && !defined(LISP_FEATURE_PPC)
560 int interrupts_enabled = (SymbolValue(INTERRUPTS_ENABLED,thread) != NIL);
561 int gc_inhibit = (SymbolValue(GC_INHIBIT,thread) != NIL);
562 int gc_pending = (SymbolValue(GC_PENDING,thread) == T);
563 int pseudo_atomic_interrupted = get_pseudo_atomic_interrupted(thread);
564 int in_race_p = in_leaving_without_gcing_race_p(thread);
565 /* In the time window between leaving the *INTERRUPTS-ENABLED* NIL
566 * section and trapping, a SIG_STOP_FOR_GC would see the next
567 * check fail, for this reason sig_stop_for_gc handler does not
568 * call this function. */
569 if (interrupt_deferred_p) {
570 if (!(!interrupts_enabled || pseudo_atomic_interrupted || in_race_p))
571 lose("Stray deferred interrupt.\n");
574 if (!(pseudo_atomic_interrupted || gc_inhibit || in_race_p))
575 lose("GC_PENDING, but why?\n");
576 #if defined(LISP_FEATURE_SB_THREAD)
578 int stop_for_gc_pending =
579 (SymbolValue(STOP_FOR_GC_PENDING,thread) != NIL);
580 if (stop_for_gc_pending)
581 if (!(pseudo_atomic_interrupted || gc_inhibit || in_race_p))
582 lose("STOP_FOR_GC_PENDING, but why?\n");
583 if (pseudo_atomic_interrupted)
584 if (!(gc_pending || stop_for_gc_pending || interrupt_deferred_p))
585 lose("pseudo_atomic_interrupted, but why?\n");
588 if (pseudo_atomic_interrupted)
589 if (!(gc_pending || interrupt_deferred_p))
590 lose("pseudo_atomic_interrupted, but why?\n");
593 if (interrupt_pending && !interrupt_deferred_p)
594 lose("INTERRUPT_PENDING but not pending handler.\n");
595 if ((data->gc_blocked_deferrables) && interrupt_pending)
596 lose("gc_blocked_deferrables and interrupt pending\n.");
597 if (data->gc_blocked_deferrables)
598 check_deferrables_blocked_or_lose(sigset);
599 if (interrupt_pending || interrupt_deferred_p ||
600 data->gc_blocked_deferrables)
601 check_deferrables_blocked_or_lose(sigset);
603 check_deferrables_unblocked_or_lose(sigset);
604 #ifndef LISP_FEATURE_SB_SAFEPOINT
605 /* If deferrables are unblocked then we are open to signals
606 * that run lisp code. */
607 check_gc_signals_unblocked_or_lose(sigset);
614 * utility routines used by various signal handlers
618 build_fake_control_stack_frames(struct thread *th,os_context_t *context)
620 #ifndef LISP_FEATURE_C_STACK_IS_CONTROL_STACK
624 /* Build a fake stack frame or frames */
626 access_control_frame_pointer(th) =
627 (lispobj *)(unsigned long)
628 (*os_context_register_addr(context, reg_CSP));
629 if ((lispobj *)(unsigned long)
630 (*os_context_register_addr(context, reg_CFP))
631 == access_control_frame_pointer(th)) {
632 /* There is a small window during call where the callee's
633 * frame isn't built yet. */
634 if (lowtag_of(*os_context_register_addr(context, reg_CODE))
635 == FUN_POINTER_LOWTAG) {
636 /* We have called, but not built the new frame, so
637 * build it for them. */
638 access_control_frame_pointer(th)[0] =
639 *os_context_register_addr(context, reg_OCFP);
640 access_control_frame_pointer(th)[1] =
641 *os_context_register_addr(context, reg_LRA);
642 access_control_frame_pointer(th) += 8;
643 /* Build our frame on top of it. */
644 oldcont = (lispobj)(*os_context_register_addr(context, reg_CFP));
647 /* We haven't yet called, build our frame as if the
648 * partial frame wasn't there. */
649 oldcont = (lispobj)(*os_context_register_addr(context, reg_OCFP));
652 /* We can't tell whether we are still in the caller if it had to
653 * allocate a stack frame due to stack arguments. */
654 /* This observation provoked some past CMUCL maintainer to ask
655 * "Can anything strange happen during return?" */
658 oldcont = (lispobj)(*os_context_register_addr(context, reg_CFP));
661 access_control_stack_pointer(th) = access_control_frame_pointer(th) + 8;
663 access_control_frame_pointer(th)[0] = oldcont;
664 access_control_frame_pointer(th)[1] = NIL;
665 access_control_frame_pointer(th)[2] =
666 (lispobj)(*os_context_register_addr(context, reg_CODE));
670 /* Stores the context for gc to scavange and builds fake stack
673 fake_foreign_function_call(os_context_t *context)
676 struct thread *thread=arch_os_get_current_thread();
678 /* context_index incrementing must not be interrupted */
679 check_blockables_blocked_or_lose(0);
681 /* Get current Lisp state from context. */
683 #ifdef LISP_FEATURE_SB_THREAD
684 thread->pseudo_atomic_bits =
686 dynamic_space_free_pointer =
687 (lispobj *)(unsigned long)
689 (*os_context_register_addr(context, reg_ALLOC));
690 /* fprintf(stderr,"dynamic_space_free_pointer: %p\n", */
691 /* dynamic_space_free_pointer); */
692 #if defined(LISP_FEATURE_ALPHA) || defined(LISP_FEATURE_MIPS)
693 if ((long)dynamic_space_free_pointer & 1) {
694 lose("dead in fake_foreign_function_call, context = %x\n", context);
697 /* why doesnt PPC and SPARC do something like this: */
698 #if defined(LISP_FEATURE_HPPA)
699 if ((long)dynamic_space_free_pointer & 4) {
700 lose("dead in fake_foreign_function_call, context = %x, d_s_f_p = %x\n", context, dynamic_space_free_pointer);
705 set_binding_stack_pointer(thread,
706 *os_context_register_addr(context, reg_BSP));
709 build_fake_control_stack_frames(thread,context);
711 /* Do dynamic binding of the active interrupt context index
712 * and save the context in the context array. */
714 fixnum_value(SymbolValue(FREE_INTERRUPT_CONTEXT_INDEX,thread));
716 if (context_index >= MAX_INTERRUPTS) {
717 lose("maximum interrupt nesting depth (%d) exceeded\n", MAX_INTERRUPTS);
720 bind_variable(FREE_INTERRUPT_CONTEXT_INDEX,
721 make_fixnum(context_index + 1),thread);
723 thread->interrupt_contexts[context_index] = context;
725 #if !defined(LISP_FEATURE_X86) && !defined(LISP_FEATURE_X86_64)
726 /* x86oid targets don't maintain the foreign function call flag at
727 * all, so leave them to believe that they are never in foreign
729 foreign_function_call_active_p(thread) = 1;
733 /* blocks all blockable signals. If you are calling from a signal handler,
734 * the usual signal mask will be restored from the context when the handler
735 * finishes. Otherwise, be careful */
737 undo_fake_foreign_function_call(os_context_t *context)
739 struct thread *thread=arch_os_get_current_thread();
740 /* Block all blockable signals. */
741 block_blockable_signals(0, 0);
743 foreign_function_call_active_p(thread) = 0;
745 /* Undo dynamic binding of FREE_INTERRUPT_CONTEXT_INDEX */
748 #if defined(reg_ALLOC) && !defined(LISP_FEATURE_SB_THREAD)
749 /* Put the dynamic space free pointer back into the context. */
750 *os_context_register_addr(context, reg_ALLOC) =
751 (unsigned long) dynamic_space_free_pointer
752 | (*os_context_register_addr(context, reg_ALLOC)
755 ((unsigned long)(*os_context_register_addr(context, reg_ALLOC))
757 | ((unsigned long) dynamic_space_free_pointer & LOWTAG_MASK);
760 #if defined(reg_ALLOC) && defined(LISP_FEATURE_SB_THREAD)
761 /* Put the pseudo-atomic bits and dynamic space free pointer back
762 * into the context (p-a-bits for p-a, and dynamic space free
763 * pointer for ROOM). */
764 *os_context_register_addr(context, reg_ALLOC) =
765 (unsigned long) dynamic_space_free_pointer
766 | (thread->pseudo_atomic_bits & LOWTAG_MASK);
767 /* And clear them so we don't get bit later by call-in/call-out
768 * not updating them. */
769 thread->pseudo_atomic_bits = 0;
773 /* a handler for the signal caused by execution of a trap opcode
774 * signalling an internal error */
776 interrupt_internal_error(os_context_t *context, boolean continuable)
780 fake_foreign_function_call(context);
782 if (!internal_errors_enabled) {
783 describe_internal_error(context);
784 /* There's no good way to recover from an internal error
785 * before the Lisp error handling mechanism is set up. */
786 lose("internal error too early in init, can't recover\n");
789 /* Allocate the SAP object while the interrupts are still
791 #ifndef LISP_FEATURE_SB_SAFEPOINT
792 unblock_gc_signals(0, 0);
794 context_sap = alloc_sap(context);
796 #ifndef LISP_FEATURE_WIN32
797 thread_sigmask(SIG_SETMASK, os_context_sigmask_addr(context), 0);
800 #if defined(LISP_FEATURE_LINUX) && defined(LISP_FEATURE_MIPS)
801 /* Workaround for blocked SIGTRAP. */
804 sigemptyset(&newset);
805 sigaddset(&newset, SIGTRAP);
806 thread_sigmask(SIG_UNBLOCK, &newset, 0);
810 SHOW("in interrupt_internal_error");
812 /* Display some rudimentary debugging information about the
813 * error, so that even if the Lisp error handler gets badly
814 * confused, we have a chance to determine what's going on. */
815 describe_internal_error(context);
817 funcall2(StaticSymbolFunction(INTERNAL_ERROR), context_sap,
818 continuable ? T : NIL);
820 undo_fake_foreign_function_call(context); /* blocks signals again */
822 arch_skip_instruction(context);
826 interrupt_handler_pending_p(void)
828 struct thread *thread = arch_os_get_current_thread();
829 struct interrupt_data *data = thread->interrupt_data;
830 return (data->pending_handler != 0);
834 interrupt_handle_pending(os_context_t *context)
836 /* There are three ways we can get here. First, if an interrupt
837 * occurs within pseudo-atomic, it will be deferred, and we'll
838 * trap to here at the end of the pseudo-atomic block. Second, if
839 * the GC (in alloc()) decides that a GC is required, it will set
840 * *GC-PENDING* and pseudo-atomic-interrupted if not *GC-INHIBIT*,
841 * and alloc() is always called from within pseudo-atomic, and
842 * thus we end up here again. Third, when calling GC-ON or at the
843 * end of a WITHOUT-GCING, MAYBE-HANDLE-PENDING-GC will trap to
844 * here if there is a pending GC. Fourth, ahem, at the end of
845 * WITHOUT-INTERRUPTS (bar complications with nesting). */
847 /* Win32 only needs to handle the GC cases (for now?) */
849 struct thread *thread = arch_os_get_current_thread();
850 struct interrupt_data *data = thread->interrupt_data;
852 if (arch_pseudo_atomic_atomic(context)) {
853 lose("Handling pending interrupt in pseudo atomic.");
856 FSHOW_SIGNAL((stderr, "/entering interrupt_handle_pending\n"));
858 check_blockables_blocked_or_lose(0);
859 #ifndef LISP_FEATURE_SB_SAFEPOINT
861 * (On safepoint builds, there is no gc_blocked_deferrables nor
864 /* If GC/SIG_STOP_FOR_GC struck during PA and there was no pending
865 * handler, then the pending mask was saved and
866 * gc_blocked_deferrables set. Hence, there can be no pending
867 * handler and it's safe to restore the pending mask.
869 * Note, that if gc_blocked_deferrables is false we may still have
870 * to GC. In this case, we are coming out of a WITHOUT-GCING or a
871 * pseudo atomic was interrupt be a deferrable first. */
872 if (data->gc_blocked_deferrables) {
873 if (data->pending_handler)
874 lose("GC blocked deferrables but still got a pending handler.");
875 if (SymbolValue(GC_INHIBIT,thread)!=NIL)
876 lose("GC blocked deferrables while GC is inhibited.");
877 /* Restore the saved signal mask from the original signal (the
878 * one that interrupted us during the critical section) into
879 * the os_context for the signal we're currently in the
880 * handler for. This should ensure that when we return from
881 * the handler the blocked signals are unblocked. */
882 #ifndef LISP_FEATURE_WIN32
883 sigcopyset(os_context_sigmask_addr(context), &data->pending_mask);
885 data->gc_blocked_deferrables = 0;
889 if (SymbolValue(GC_INHIBIT,thread)==NIL) {
890 void *original_pending_handler = data->pending_handler;
892 #ifdef LISP_FEATURE_SB_SAFEPOINT
893 /* handles the STOP_FOR_GC_PENDING case */
894 thread_pitstop(context);
895 #elif defined(LISP_FEATURE_SB_THREAD)
896 if (SymbolValue(STOP_FOR_GC_PENDING,thread) != NIL) {
897 /* STOP_FOR_GC_PENDING and GC_PENDING are cleared by
898 * the signal handler if it actually stops us. */
899 arch_clear_pseudo_atomic_interrupted(context);
900 sig_stop_for_gc_handler(SIG_STOP_FOR_GC,NULL,context);
903 /* Test for T and not for != NIL since the value :IN-PROGRESS
904 * is used in SUB-GC as part of the mechanism to supress
906 if (SymbolValue(GC_PENDING,thread) == T) {
908 /* Two reasons for doing this. First, if there is a
909 * pending handler we don't want to run. Second, we are
910 * going to clear pseudo atomic interrupted to avoid
911 * spurious trapping on every allocation in SUB_GC and
912 * having a pending handler with interrupts enabled and
913 * without pseudo atomic interrupted breaks an
915 if (data->pending_handler) {
916 bind_variable(ALLOW_WITH_INTERRUPTS, NIL, thread);
917 bind_variable(INTERRUPTS_ENABLED, NIL, thread);
920 arch_clear_pseudo_atomic_interrupted(context);
922 /* GC_PENDING is cleared in SUB-GC, or if another thread
923 * is doing a gc already we will get a SIG_STOP_FOR_GC and
924 * that will clear it.
926 * If there is a pending handler or gc was triggerred in a
927 * signal handler then maybe_gc won't run POST_GC and will
928 * return normally. */
929 if (!maybe_gc(context))
930 lose("GC not inhibited but maybe_gc did not GC.");
932 if (data->pending_handler) {
936 } else if (SymbolValue(GC_PENDING,thread) != NIL) {
937 /* It's not NIL or T so GC_PENDING is :IN-PROGRESS. If
938 * GC-PENDING is not NIL then we cannot trap on pseudo
939 * atomic due to GC (see if(GC_PENDING) logic in
940 * cheneygc.c an gengcgc.c), plus there is a outer
941 * WITHOUT-INTERRUPTS SUB_GC, so how did we end up
943 lose("Trapping to run pending handler while GC in progress.");
946 check_blockables_blocked_or_lose(0);
948 /* No GC shall be lost. If SUB_GC triggers another GC then
949 * that should be handled on the spot. */
950 if (SymbolValue(GC_PENDING,thread) != NIL)
951 lose("GC_PENDING after doing gc.");
952 #ifdef THREADS_USING_GCSIGNAL
953 if (SymbolValue(STOP_FOR_GC_PENDING,thread) != NIL)
954 lose("STOP_FOR_GC_PENDING after doing gc.");
956 /* Check two things. First, that gc does not clobber a handler
957 * that's already pending. Second, that there is no interrupt
958 * lossage: if original_pending_handler was NULL then even if
959 * an interrupt arrived during GC (POST-GC, really) it was
961 if (original_pending_handler != data->pending_handler)
962 lose("pending handler changed in gc: %x -> %d.",
963 original_pending_handler, data->pending_handler);
966 #ifndef LISP_FEATURE_WIN32
967 /* There may be no pending handler, because it was only a gc that
968 * had to be executed or because Lisp is a bit too eager to call
969 * DO-PENDING-INTERRUPT. */
970 if ((SymbolValue(INTERRUPTS_ENABLED,thread) != NIL) &&
971 (data->pending_handler)) {
972 /* No matter how we ended up here, clear both
973 * INTERRUPT_PENDING and pseudo atomic interrupted. It's safe
974 * because we checked above that there is no GC pending. */
975 SetSymbolValue(INTERRUPT_PENDING, NIL, thread);
976 arch_clear_pseudo_atomic_interrupted(context);
977 /* Restore the sigmask in the context. */
978 sigcopyset(os_context_sigmask_addr(context), &data->pending_mask);
979 run_deferred_handler(data, context);
982 #ifdef LISP_FEATURE_GENCGC
983 if (get_pseudo_atomic_interrupted(thread))
984 lose("pseudo_atomic_interrupted after interrupt_handle_pending\n");
986 /* It is possible that the end of this function was reached
987 * without never actually doing anything, the tests in Lisp for
988 * when to call receive-pending-interrupt are not exact. */
989 FSHOW_SIGNAL((stderr, "/exiting interrupt_handle_pending\n"));
994 interrupt_handle_now(int signal, siginfo_t *info, os_context_t *context)
996 boolean were_in_lisp;
997 union interrupt_handler handler;
999 check_blockables_blocked_or_lose(0);
1001 #ifndef LISP_FEATURE_WIN32
1002 if (sigismember(&deferrable_sigset,signal))
1003 check_interrupts_enabled_or_lose(context);
1006 handler = interrupt_handlers[signal];
1008 if (ARE_SAME_HANDLER(handler.c, SIG_IGN)) {
1012 were_in_lisp = !foreign_function_call_active_p(arch_os_get_current_thread());
1015 fake_foreign_function_call(context);
1018 FSHOW_SIGNAL((stderr,
1019 "/entering interrupt_handle_now(%d, info, context)\n",
1022 if (ARE_SAME_HANDLER(handler.c, SIG_DFL)) {
1024 /* This can happen if someone tries to ignore or default one
1025 * of the signals we need for runtime support, and the runtime
1026 * support decides to pass on it. */
1027 lose("no handler for signal %d in interrupt_handle_now(..)\n", signal);
1029 } else if (lowtag_of(handler.lisp) == FUN_POINTER_LOWTAG) {
1030 /* Once we've decided what to do about contexts in a
1031 * return-elsewhere world (the original context will no longer
1032 * be available; should we copy it or was nobody using it anyway?)
1033 * then we should convert this to return-elsewhere */
1035 /* CMUCL comment said "Allocate the SAPs while the interrupts
1036 * are still disabled.". I (dan, 2003.08.21) assume this is
1037 * because we're not in pseudoatomic and allocation shouldn't
1038 * be interrupted. In which case it's no longer an issue as
1039 * all our allocation from C now goes through a PA wrapper,
1040 * but still, doesn't hurt.
1042 * Yeah, but non-gencgc platforms don't really wrap allocation
1043 * in PA. MG - 2005-08-29 */
1045 lispobj info_sap, context_sap;
1046 /* Leave deferrable signals blocked, the handler itself will
1047 * allow signals again when it sees fit. */
1048 #ifndef LISP_FEATURE_SB_SAFEPOINT
1049 unblock_gc_signals(0, 0);
1051 context_sap = alloc_sap(context);
1052 info_sap = alloc_sap(info);
1054 FSHOW_SIGNAL((stderr,"/calling Lisp-level handler\n"));
1056 #ifdef LISP_FEATURE_SB_SAFEPOINT
1057 WITH_GC_AT_SAFEPOINTS_ONLY()
1059 funcall3(handler.lisp,
1060 make_fixnum(signal),
1064 /* This cannot happen in sane circumstances. */
1066 FSHOW_SIGNAL((stderr,"/calling C-level handler\n"));
1068 #ifndef LISP_FEATURE_WIN32
1069 /* Allow signals again. */
1070 thread_sigmask(SIG_SETMASK, os_context_sigmask_addr(context), 0);
1072 (*handler.c)(signal, info, context);
1077 undo_fake_foreign_function_call(context); /* block signals again */
1080 FSHOW_SIGNAL((stderr,
1081 "/returning from interrupt_handle_now(%d, info, context)\n",
1085 /* This is called at the end of a critical section if the indications
1086 * are that some signal was deferred during the section. Note that as
1087 * far as C or the kernel is concerned we dealt with the signal
1088 * already; we're just doing the Lisp-level processing now that we
1091 run_deferred_handler(struct interrupt_data *data, os_context_t *context)
1093 /* The pending_handler may enable interrupts and then another
1094 * interrupt may hit, overwrite interrupt_data, so reset the
1095 * pending handler before calling it. Trust the handler to finish
1096 * with the siginfo before enabling interrupts. */
1097 void (*pending_handler) (int, siginfo_t*, os_context_t*) =
1098 data->pending_handler;
1100 data->pending_handler=0;
1101 FSHOW_SIGNAL((stderr, "/running deferred handler %p\n", pending_handler));
1102 (*pending_handler)(data->pending_signal,&(data->pending_info), context);
1105 #ifndef LISP_FEATURE_WIN32
1107 maybe_defer_handler(void *handler, struct interrupt_data *data,
1108 int signal, siginfo_t *info, os_context_t *context)
1110 struct thread *thread=arch_os_get_current_thread();
1112 check_blockables_blocked_or_lose(0);
1114 if (SymbolValue(INTERRUPT_PENDING,thread) != NIL)
1115 lose("interrupt already pending\n");
1116 if (thread->interrupt_data->pending_handler)
1117 lose("there is a pending handler already (PA)\n");
1118 if (data->gc_blocked_deferrables)
1119 lose("maybe_defer_handler: gc_blocked_deferrables true\n");
1120 check_interrupt_context_or_lose(context);
1121 /* If interrupts are disabled then INTERRUPT_PENDING is set and
1122 * not PSEDUO_ATOMIC_INTERRUPTED. This is important for a pseudo
1123 * atomic section inside a WITHOUT-INTERRUPTS.
1125 * Also, if in_leaving_without_gcing_race_p then
1126 * interrupt_handle_pending is going to be called soon, so
1127 * stashing the signal away is safe.
1129 if ((SymbolValue(INTERRUPTS_ENABLED,thread) == NIL) ||
1130 in_leaving_without_gcing_race_p(thread)) {
1131 FSHOW_SIGNAL((stderr,
1132 "/maybe_defer_handler(%x,%d): deferred (RACE=%d)\n",
1133 (unsigned int)handler,signal,
1134 in_leaving_without_gcing_race_p(thread)));
1135 store_signal_data_for_later(data,handler,signal,info,context);
1136 SetSymbolValue(INTERRUPT_PENDING, T,thread);
1137 check_interrupt_context_or_lose(context);
1140 /* a slightly confusing test. arch_pseudo_atomic_atomic() doesn't
1141 * actually use its argument for anything on x86, so this branch
1142 * may succeed even when context is null (gencgc alloc()) */
1143 if (arch_pseudo_atomic_atomic(context)) {
1144 FSHOW_SIGNAL((stderr,
1145 "/maybe_defer_handler(%x,%d): deferred(PA)\n",
1146 (unsigned int)handler,signal));
1147 store_signal_data_for_later(data,handler,signal,info,context);
1148 arch_set_pseudo_atomic_interrupted(context);
1149 check_interrupt_context_or_lose(context);
1152 FSHOW_SIGNAL((stderr,
1153 "/maybe_defer_handler(%x,%d): not deferred\n",
1154 (unsigned int)handler,signal));
1159 store_signal_data_for_later (struct interrupt_data *data, void *handler,
1161 siginfo_t *info, os_context_t *context)
1163 if (data->pending_handler)
1164 lose("tried to overwrite pending interrupt handler %x with %x\n",
1165 data->pending_handler, handler);
1167 lose("tried to defer null interrupt handler\n");
1168 data->pending_handler = handler;
1169 data->pending_signal = signal;
1171 memcpy(&(data->pending_info), info, sizeof(siginfo_t));
1173 FSHOW_SIGNAL((stderr, "/store_signal_data_for_later: signal: %d\n",
1177 lose("Null context");
1179 /* the signal mask in the context (from before we were
1180 * interrupted) is copied to be restored when run_deferred_handler
1181 * happens. Then the usually-blocked signals are added to the mask
1182 * in the context so that we are running with blocked signals when
1183 * the handler returns */
1184 sigcopyset(&(data->pending_mask),os_context_sigmask_addr(context));
1185 sigaddset_deferrable(os_context_sigmask_addr(context));
1189 maybe_now_maybe_later(int signal, siginfo_t *info, void *void_context)
1191 SAVE_ERRNO(signal,context,void_context);
1192 struct thread *thread = arch_os_get_current_thread();
1193 struct interrupt_data *data = thread->interrupt_data;
1194 if(!maybe_defer_handler(interrupt_handle_now,data,signal,info,context))
1195 interrupt_handle_now(signal, info, context);
1200 low_level_interrupt_handle_now(int signal, siginfo_t *info,
1201 os_context_t *context)
1203 /* No FP control fixage needed, caller has done that. */
1204 check_blockables_blocked_or_lose(0);
1205 check_interrupts_enabled_or_lose(context);
1206 (*interrupt_low_level_handlers[signal])(signal, info, context);
1207 /* No Darwin context fixage needed, caller does that. */
1211 low_level_maybe_now_maybe_later(int signal, siginfo_t *info, void *void_context)
1213 SAVE_ERRNO(signal,context,void_context);
1214 struct thread *thread = arch_os_get_current_thread();
1215 struct interrupt_data *data = thread->interrupt_data;
1217 if(!maybe_defer_handler(low_level_interrupt_handle_now,data,
1218 signal,info,context))
1219 low_level_interrupt_handle_now(signal, info, context);
1224 #ifdef THREADS_USING_GCSIGNAL
1226 /* This function must not cons, because that may trigger a GC. */
1228 sig_stop_for_gc_handler(int signal, siginfo_t *info, os_context_t *context)
1230 struct thread *thread=arch_os_get_current_thread();
1231 boolean was_in_lisp;
1233 /* Test for GC_INHIBIT _first_, else we'd trap on every single
1234 * pseudo atomic until gc is finally allowed. */
1235 if (SymbolValue(GC_INHIBIT,thread) != NIL) {
1236 FSHOW_SIGNAL((stderr, "sig_stop_for_gc deferred (*GC-INHIBIT*)\n"));
1237 SetSymbolValue(STOP_FOR_GC_PENDING,T,thread);
1239 } else if (arch_pseudo_atomic_atomic(context)) {
1240 FSHOW_SIGNAL((stderr,"sig_stop_for_gc deferred (PA)\n"));
1241 SetSymbolValue(STOP_FOR_GC_PENDING,T,thread);
1242 arch_set_pseudo_atomic_interrupted(context);
1243 maybe_save_gc_mask_and_block_deferrables
1244 (os_context_sigmask_addr(context));
1248 FSHOW_SIGNAL((stderr, "/sig_stop_for_gc_handler\n"));
1250 /* Not PA and GC not inhibited -- we can stop now. */
1252 was_in_lisp = !foreign_function_call_active_p(arch_os_get_current_thread());
1255 /* need the context stored so it can have registers scavenged */
1256 fake_foreign_function_call(context);
1259 /* Not pending anymore. */
1260 SetSymbolValue(GC_PENDING,NIL,thread);
1261 SetSymbolValue(STOP_FOR_GC_PENDING,NIL,thread);
1263 /* Consider this: in a PA section GC is requested: GC_PENDING,
1264 * pseudo_atomic_interrupted and gc_blocked_deferrables are set,
1265 * deferrables are blocked then pseudo_atomic_atomic is cleared,
1266 * but a SIG_STOP_FOR_GC arrives before trapping to
1267 * interrupt_handle_pending. Here, GC_PENDING is cleared but
1268 * pseudo_atomic_interrupted is not and we go on running with
1269 * pseudo_atomic_interrupted but without a pending interrupt or
1270 * GC. GC_BLOCKED_DEFERRABLES is also left at 1. So let's tidy it
1272 if (thread->interrupt_data->gc_blocked_deferrables) {
1273 FSHOW_SIGNAL((stderr,"cleaning up after gc_blocked_deferrables\n"));
1274 clear_pseudo_atomic_interrupted(thread);
1275 sigcopyset(os_context_sigmask_addr(context),
1276 &thread->interrupt_data->pending_mask);
1277 thread->interrupt_data->gc_blocked_deferrables = 0;
1280 if(thread_state(thread)!=STATE_RUNNING) {
1281 lose("sig_stop_for_gc_handler: wrong thread state: %ld\n",
1282 fixnum_value(thread->state));
1285 set_thread_state(thread,STATE_STOPPED);
1286 FSHOW_SIGNAL((stderr,"suspended\n"));
1288 /* While waiting for gc to finish occupy ourselves with zeroing
1289 * the unused portion of the control stack to reduce conservatism.
1290 * On hypothetic platforms with threads and exact gc it is
1291 * actually a must. */
1292 scrub_control_stack();
1294 wait_for_thread_state_change(thread, STATE_STOPPED);
1295 FSHOW_SIGNAL((stderr,"resumed\n"));
1297 if(thread_state(thread)!=STATE_RUNNING) {
1298 lose("sig_stop_for_gc_handler: wrong thread state on wakeup: %ld\n",
1299 fixnum_value(thread_state(thread)));
1303 undo_fake_foreign_function_call(context);
1310 interrupt_handle_now_handler(int signal, siginfo_t *info, void *void_context)
1312 SAVE_ERRNO(signal,context,void_context);
1313 #ifndef LISP_FEATURE_WIN32
1314 if ((signal == SIGILL) || (signal == SIGBUS)
1315 #ifndef LISP_FEATURE_LINUX
1316 || (signal == SIGEMT)
1319 corruption_warning_and_maybe_lose("Signal %d received", signal);
1321 interrupt_handle_now(signal, info, context);
1325 /* manipulate the signal context and stack such that when the handler
1326 * returns, it will call function instead of whatever it was doing
1330 #if (defined(LISP_FEATURE_X86) || defined(LISP_FEATURE_X86_64))
1331 extern int *context_eflags_addr(os_context_t *context);
1334 extern lispobj call_into_lisp(lispobj fun, lispobj *args, int nargs);
1335 extern void post_signal_tramp(void);
1336 extern void call_into_lisp_tramp(void);
1339 arrange_return_to_c_function(os_context_t *context,
1340 call_into_lisp_lookalike funptr,
1343 #if !(defined(LISP_FEATURE_WIN32) || defined(LISP_FEATURE_SB_SAFEPOINT))
1344 check_gc_signals_unblocked_or_lose
1345 (os_context_sigmask_addr(context));
1347 #if !(defined(LISP_FEATURE_X86) || defined(LISP_FEATURE_X86_64))
1348 void * fun=native_pointer(function);
1349 void *code = &(((struct simple_fun *) fun)->code);
1352 /* Build a stack frame showing `interrupted' so that the
1353 * user's backtrace makes (as much) sense (as usual) */
1355 /* fp state is saved and restored by call_into_lisp */
1356 /* FIXME: errno is not restored, but since current uses of this
1357 * function only call Lisp code that signals an error, it's not
1358 * much of a problem. In other words, running out of the control
1359 * stack between a syscall and (GET-ERRNO) may clobber errno if
1360 * something fails during signalling or in the handler. But I
1361 * can't see what can go wrong as long as there is no CONTINUE
1362 * like restart on them. */
1363 #ifdef LISP_FEATURE_X86
1364 /* Suppose the existence of some function that saved all
1365 * registers, called call_into_lisp, then restored GP registers and
1366 * returned. It would look something like this:
1374 pushl {address of function to call}
1375 call 0x8058db0 <call_into_lisp>
1382 * What we do here is set up the stack that call_into_lisp would
1383 * expect to see if it had been called by this code, and frob the
1384 * signal context so that signal return goes directly to call_into_lisp,
1385 * and when that function (and the lisp function it invoked) returns,
1386 * it returns to the second half of this imaginary function which
1387 * restores all registers and returns to C
1389 * For this to work, the latter part of the imaginary function
1390 * must obviously exist in reality. That would be post_signal_tramp
1393 u32 *sp=(u32 *)*os_context_register_addr(context,reg_ESP);
1395 #if defined(LISP_FEATURE_DARWIN)
1396 u32 *register_save_area = (u32 *)os_validate(0, 0x40);
1398 FSHOW_SIGNAL((stderr, "/arrange_return_to_lisp_function: preparing to go to function %x, sp: %x\n", function, sp));
1399 FSHOW_SIGNAL((stderr, "/arrange_return_to_lisp_function: context: %x, &context %x\n", context, &context));
1401 /* 1. os_validate (malloc/mmap) register_save_block
1402 * 2. copy register state into register_save_block
1403 * 3. put a pointer to register_save_block in a register in the context
1404 * 4. set the context's EIP to point to a trampoline which:
1405 * a. builds the fake stack frame from the block
1406 * b. frees the block
1407 * c. calls the function
1410 *register_save_area = *os_context_pc_addr(context);
1411 *(register_save_area + 1) = function;
1412 *(register_save_area + 2) = *os_context_register_addr(context,reg_EDI);
1413 *(register_save_area + 3) = *os_context_register_addr(context,reg_ESI);
1414 *(register_save_area + 4) = *os_context_register_addr(context,reg_EDX);
1415 *(register_save_area + 5) = *os_context_register_addr(context,reg_ECX);
1416 *(register_save_area + 6) = *os_context_register_addr(context,reg_EBX);
1417 *(register_save_area + 7) = *os_context_register_addr(context,reg_EAX);
1418 *(register_save_area + 8) = *context_eflags_addr(context);
1420 *os_context_pc_addr(context) =
1421 (os_context_register_t) funptr;
1422 *os_context_register_addr(context,reg_ECX) =
1423 (os_context_register_t) register_save_area;
1426 /* return address for call_into_lisp: */
1427 *(sp-15) = (u32)post_signal_tramp;
1428 *(sp-14) = function; /* args for call_into_lisp : function*/
1429 *(sp-13) = 0; /* arg array */
1430 *(sp-12) = 0; /* no. args */
1431 /* this order matches that used in POPAD */
1432 *(sp-11)=*os_context_register_addr(context,reg_EDI);
1433 *(sp-10)=*os_context_register_addr(context,reg_ESI);
1435 *(sp-9)=*os_context_register_addr(context,reg_ESP)-8;
1436 /* POPAD ignores the value of ESP: */
1438 *(sp-7)=*os_context_register_addr(context,reg_EBX);
1440 *(sp-6)=*os_context_register_addr(context,reg_EDX);
1441 *(sp-5)=*os_context_register_addr(context,reg_ECX);
1442 *(sp-4)=*os_context_register_addr(context,reg_EAX);
1443 *(sp-3)=*context_eflags_addr(context);
1444 *(sp-2)=*os_context_register_addr(context,reg_EBP);
1445 *(sp-1)=*os_context_pc_addr(context);
1449 #elif defined(LISP_FEATURE_X86_64)
1450 u64 *sp=(u64 *)*os_context_register_addr(context,reg_RSP);
1452 /* return address for call_into_lisp: */
1453 *(sp-18) = (u64)post_signal_tramp;
1455 *(sp-17)=*os_context_register_addr(context,reg_R15);
1456 *(sp-16)=*os_context_register_addr(context,reg_R14);
1457 *(sp-15)=*os_context_register_addr(context,reg_R13);
1458 *(sp-14)=*os_context_register_addr(context,reg_R12);
1459 *(sp-13)=*os_context_register_addr(context,reg_R11);
1460 *(sp-12)=*os_context_register_addr(context,reg_R10);
1461 *(sp-11)=*os_context_register_addr(context,reg_R9);
1462 *(sp-10)=*os_context_register_addr(context,reg_R8);
1463 *(sp-9)=*os_context_register_addr(context,reg_RDI);
1464 *(sp-8)=*os_context_register_addr(context,reg_RSI);
1465 /* skip RBP and RSP */
1466 *(sp-7)=*os_context_register_addr(context,reg_RBX);
1467 *(sp-6)=*os_context_register_addr(context,reg_RDX);
1468 *(sp-5)=*os_context_register_addr(context,reg_RCX);
1469 *(sp-4)=*os_context_register_addr(context,reg_RAX);
1470 *(sp-3)=*context_eflags_addr(context);
1471 *(sp-2)=*os_context_register_addr(context,reg_RBP);
1472 *(sp-1)=*os_context_pc_addr(context);
1474 *os_context_register_addr(context,reg_RDI) =
1475 (os_context_register_t)function; /* function */
1476 *os_context_register_addr(context,reg_RSI) = 0; /* arg. array */
1477 *os_context_register_addr(context,reg_RDX) = 0; /* no. args */
1479 struct thread *th=arch_os_get_current_thread();
1480 build_fake_control_stack_frames(th,context);
1483 #ifdef LISP_FEATURE_X86
1485 #if !defined(LISP_FEATURE_DARWIN)
1486 *os_context_pc_addr(context) = (os_context_register_t)funptr;
1487 *os_context_register_addr(context,reg_ECX) = 0;
1488 *os_context_register_addr(context,reg_EBP) = (os_context_register_t)(sp-2);
1490 *os_context_register_addr(context,reg_UESP) =
1491 (os_context_register_t)(sp-15);
1493 *os_context_register_addr(context,reg_ESP) = (os_context_register_t)(sp-15);
1494 #endif /* __NETBSD__ */
1495 #endif /* LISP_FEATURE_DARWIN */
1497 #elif defined(LISP_FEATURE_X86_64)
1498 *os_context_pc_addr(context) = (os_context_register_t)funptr;
1499 *os_context_register_addr(context,reg_RCX) = 0;
1500 *os_context_register_addr(context,reg_RBP) = (os_context_register_t)(sp-2);
1501 *os_context_register_addr(context,reg_RSP) = (os_context_register_t)(sp-18);
1503 /* this much of the calling convention is common to all
1505 *os_context_pc_addr(context) = (os_context_register_t)(unsigned long)code;
1506 *os_context_register_addr(context,reg_NARGS) = 0;
1507 *os_context_register_addr(context,reg_LIP) =
1508 (os_context_register_t)(unsigned long)code;
1509 *os_context_register_addr(context,reg_CFP) =
1510 (os_context_register_t)(unsigned long)access_control_frame_pointer(th);
1512 #ifdef ARCH_HAS_NPC_REGISTER
1513 *os_context_npc_addr(context) =
1514 4 + *os_context_pc_addr(context);
1516 #ifdef LISP_FEATURE_SPARC
1517 *os_context_register_addr(context,reg_CODE) =
1518 (os_context_register_t)(fun + FUN_POINTER_LOWTAG);
1520 FSHOW((stderr, "/arranged return to Lisp function (0x%lx)\n",
1525 arrange_return_to_lisp_function(os_context_t *context, lispobj function)
1527 #if defined(LISP_FEATURE_DARWIN)
1528 arrange_return_to_c_function(context, call_into_lisp_tramp, function);
1530 arrange_return_to_c_function(context, call_into_lisp, function);
1534 /* KLUDGE: Theoretically the approach we use for undefined alien
1535 * variables should work for functions as well, but on PPC/Darwin
1536 * we get bus error at bogus addresses instead, hence this workaround,
1537 * that has the added benefit of automatically discriminating between
1538 * functions and variables.
1541 undefined_alien_function(void)
1543 funcall0(StaticSymbolFunction(UNDEFINED_ALIEN_FUNCTION_ERROR));
1546 void lower_thread_control_stack_guard_page(struct thread *th)
1548 protect_control_stack_guard_page(0, th);
1549 protect_control_stack_return_guard_page(1, th);
1550 th->control_stack_guard_page_protected = NIL;
1551 fprintf(stderr, "INFO: Control stack guard page unprotected\n");
1554 void reset_thread_control_stack_guard_page(struct thread *th)
1556 memset(CONTROL_STACK_GUARD_PAGE(th), 0, os_vm_page_size);
1557 protect_control_stack_guard_page(1, th);
1558 protect_control_stack_return_guard_page(0, th);
1559 th->control_stack_guard_page_protected = T;
1560 fprintf(stderr, "INFO: Control stack guard page reprotected\n");
1563 /* Called from the REPL, too. */
1564 void reset_control_stack_guard_page(void)
1566 struct thread *th=arch_os_get_current_thread();
1567 if (th->control_stack_guard_page_protected == NIL) {
1568 reset_thread_control_stack_guard_page(th);
1572 void lower_control_stack_guard_page(void)
1574 lower_thread_control_stack_guard_page(arch_os_get_current_thread());
1578 handle_guard_page_triggered(os_context_t *context,os_vm_address_t addr)
1580 struct thread *th=arch_os_get_current_thread();
1582 if(addr >= CONTROL_STACK_HARD_GUARD_PAGE(th) &&
1583 addr < CONTROL_STACK_HARD_GUARD_PAGE(th) + os_vm_page_size) {
1584 lose("Control stack exhausted");
1586 else if(addr >= CONTROL_STACK_GUARD_PAGE(th) &&
1587 addr < CONTROL_STACK_GUARD_PAGE(th) + os_vm_page_size) {
1588 /* We hit the end of the control stack: disable guard page
1589 * protection so the error handler has some headroom, protect the
1590 * previous page so that we can catch returns from the guard page
1591 * and restore it. */
1592 if (th->control_stack_guard_page_protected == NIL)
1593 lose("control_stack_guard_page_protected NIL");
1594 lower_control_stack_guard_page();
1595 #ifdef LISP_FEATURE_C_STACK_IS_CONTROL_STACK
1596 /* For the unfortunate case, when the control stack is
1597 * exhausted in a signal handler. */
1598 unblock_signals_in_context_and_maybe_warn(context);
1600 arrange_return_to_lisp_function
1601 (context, StaticSymbolFunction(CONTROL_STACK_EXHAUSTED_ERROR));
1604 else if(addr >= CONTROL_STACK_RETURN_GUARD_PAGE(th) &&
1605 addr < CONTROL_STACK_RETURN_GUARD_PAGE(th) + os_vm_page_size) {
1606 /* We're returning from the guard page: reprotect it, and
1607 * unprotect this one. This works even if we somehow missed
1608 * the return-guard-page, and hit it on our way to new
1609 * exhaustion instead. */
1610 if (th->control_stack_guard_page_protected != NIL)
1611 lose("control_stack_guard_page_protected not NIL");
1612 reset_control_stack_guard_page();
1615 else if(addr >= BINDING_STACK_HARD_GUARD_PAGE(th) &&
1616 addr < BINDING_STACK_HARD_GUARD_PAGE(th) + os_vm_page_size) {
1617 lose("Binding stack exhausted");
1619 else if(addr >= BINDING_STACK_GUARD_PAGE(th) &&
1620 addr < BINDING_STACK_GUARD_PAGE(th) + os_vm_page_size) {
1621 protect_binding_stack_guard_page(0, NULL);
1622 protect_binding_stack_return_guard_page(1, NULL);
1623 fprintf(stderr, "INFO: Binding stack guard page unprotected\n");
1625 /* For the unfortunate case, when the binding stack is
1626 * exhausted in a signal handler. */
1627 unblock_signals_in_context_and_maybe_warn(context);
1628 arrange_return_to_lisp_function
1629 (context, StaticSymbolFunction(BINDING_STACK_EXHAUSTED_ERROR));
1632 else if(addr >= BINDING_STACK_RETURN_GUARD_PAGE(th) &&
1633 addr < BINDING_STACK_RETURN_GUARD_PAGE(th) + os_vm_page_size) {
1634 protect_binding_stack_guard_page(1, NULL);
1635 protect_binding_stack_return_guard_page(0, NULL);
1636 fprintf(stderr, "INFO: Binding stack guard page reprotected\n");
1639 else if(addr >= ALIEN_STACK_HARD_GUARD_PAGE(th) &&
1640 addr < ALIEN_STACK_HARD_GUARD_PAGE(th) + os_vm_page_size) {
1641 lose("Alien stack exhausted");
1643 else if(addr >= ALIEN_STACK_GUARD_PAGE(th) &&
1644 addr < ALIEN_STACK_GUARD_PAGE(th) + os_vm_page_size) {
1645 protect_alien_stack_guard_page(0, NULL);
1646 protect_alien_stack_return_guard_page(1, NULL);
1647 fprintf(stderr, "INFO: Alien stack guard page unprotected\n");
1649 /* For the unfortunate case, when the alien stack is
1650 * exhausted in a signal handler. */
1651 unblock_signals_in_context_and_maybe_warn(context);
1652 arrange_return_to_lisp_function
1653 (context, StaticSymbolFunction(ALIEN_STACK_EXHAUSTED_ERROR));
1656 else if(addr >= ALIEN_STACK_RETURN_GUARD_PAGE(th) &&
1657 addr < ALIEN_STACK_RETURN_GUARD_PAGE(th) + os_vm_page_size) {
1658 protect_alien_stack_guard_page(1, NULL);
1659 protect_alien_stack_return_guard_page(0, NULL);
1660 fprintf(stderr, "INFO: Alien stack guard page reprotected\n");
1663 else if (addr >= undefined_alien_address &&
1664 addr < undefined_alien_address + os_vm_page_size) {
1665 arrange_return_to_lisp_function
1666 (context, StaticSymbolFunction(UNDEFINED_ALIEN_VARIABLE_ERROR));
1673 * noise to install handlers
1676 #ifndef LISP_FEATURE_WIN32
1677 /* In Linux 2.4 synchronous signals (sigtrap & co) can be delivered if
1678 * they are blocked, in Linux 2.6 the default handler is invoked
1679 * instead that usually coredumps. One might hastily think that adding
1680 * SA_NODEFER helps, but until ~2.6.13 if SA_NODEFER is specified then
1681 * the whole sa_mask is ignored and instead of not adding the signal
1682 * in question to the mask. That means if it's not blockable the
1683 * signal must be unblocked at the beginning of signal handlers.
1685 * It turns out that NetBSD's SA_NODEFER doesn't DTRT in a different
1686 * way: if SA_NODEFER is set and the signal is in sa_mask, the signal
1687 * will be unblocked in the sigmask during the signal handler. -- RMK
1690 static volatile int sigaction_nodefer_works = -1;
1692 #define SA_NODEFER_TEST_BLOCK_SIGNAL SIGABRT
1693 #define SA_NODEFER_TEST_KILL_SIGNAL SIGUSR1
1696 sigaction_nodefer_test_handler(int signal, siginfo_t *info, void *void_context)
1700 get_current_sigmask(¤t);
1701 /* There should be exactly two blocked signals: the two we added
1702 * to sa_mask when setting up the handler. NetBSD doesn't block
1703 * the signal we're handling when SA_NODEFER is set; Linux before
1704 * 2.6.13 or so also doesn't block the other signal when
1705 * SA_NODEFER is set. */
1706 for(i = 1; i < NSIG; i++)
1707 if (sigismember(¤t, i) !=
1708 (((i == SA_NODEFER_TEST_BLOCK_SIGNAL) || (i == signal)) ? 1 : 0)) {
1709 FSHOW_SIGNAL((stderr, "SA_NODEFER doesn't work, signal %d\n", i));
1710 sigaction_nodefer_works = 0;
1712 if (sigaction_nodefer_works == -1)
1713 sigaction_nodefer_works = 1;
1717 see_if_sigaction_nodefer_works(void)
1719 struct sigaction sa, old_sa;
1721 sa.sa_flags = SA_SIGINFO | SA_NODEFER;
1722 sa.sa_sigaction = sigaction_nodefer_test_handler;
1723 sigemptyset(&sa.sa_mask);
1724 sigaddset(&sa.sa_mask, SA_NODEFER_TEST_BLOCK_SIGNAL);
1725 sigaddset(&sa.sa_mask, SA_NODEFER_TEST_KILL_SIGNAL);
1726 sigaction(SA_NODEFER_TEST_KILL_SIGNAL, &sa, &old_sa);
1727 /* Make sure no signals are blocked. */
1730 sigemptyset(&empty);
1731 thread_sigmask(SIG_SETMASK, &empty, 0);
1733 kill(getpid(), SA_NODEFER_TEST_KILL_SIGNAL);
1734 while (sigaction_nodefer_works == -1);
1735 sigaction(SA_NODEFER_TEST_KILL_SIGNAL, &old_sa, NULL);
1738 #undef SA_NODEFER_TEST_BLOCK_SIGNAL
1739 #undef SA_NODEFER_TEST_KILL_SIGNAL
1742 unblock_me_trampoline(int signal, siginfo_t *info, void *void_context)
1744 SAVE_ERRNO(signal,context,void_context);
1747 sigemptyset(&unblock);
1748 sigaddset(&unblock, signal);
1749 thread_sigmask(SIG_UNBLOCK, &unblock, 0);
1750 interrupt_handle_now(signal, info, context);
1755 low_level_unblock_me_trampoline(int signal, siginfo_t *info, void *void_context)
1757 SAVE_ERRNO(signal,context,void_context);
1760 sigemptyset(&unblock);
1761 sigaddset(&unblock, signal);
1762 thread_sigmask(SIG_UNBLOCK, &unblock, 0);
1763 (*interrupt_low_level_handlers[signal])(signal, info, context);
1768 low_level_handle_now_handler(int signal, siginfo_t *info, void *void_context)
1770 SAVE_ERRNO(signal,context,void_context);
1771 (*interrupt_low_level_handlers[signal])(signal, info, context);
1776 undoably_install_low_level_interrupt_handler (int signal,
1777 interrupt_handler_t handler)
1779 struct sigaction sa;
1781 if (0 > signal || signal >= NSIG) {
1782 lose("bad signal number %d\n", signal);
1785 if (ARE_SAME_HANDLER(handler, SIG_DFL))
1786 sa.sa_sigaction = (void (*)(int, siginfo_t*, void*))handler;
1787 else if (sigismember(&deferrable_sigset,signal))
1788 sa.sa_sigaction = low_level_maybe_now_maybe_later;
1789 else if (!sigaction_nodefer_works &&
1790 !sigismember(&blockable_sigset, signal))
1791 sa.sa_sigaction = low_level_unblock_me_trampoline;
1793 sa.sa_sigaction = low_level_handle_now_handler;
1795 sigcopyset(&sa.sa_mask, &blockable_sigset);
1796 sa.sa_flags = SA_SIGINFO | SA_RESTART
1797 | (sigaction_nodefer_works ? SA_NODEFER : 0);
1798 #ifdef LISP_FEATURE_C_STACK_IS_CONTROL_STACK
1799 if(signal==SIG_MEMORY_FAULT) {
1800 sa.sa_flags |= SA_ONSTACK;
1801 # ifdef LISP_FEATURE_SB_SAFEPOINT
1802 sigaddset(&sa.sa_mask, SIGRTMIN);
1803 sigaddset(&sa.sa_mask, SIGRTMIN+1);
1808 sigaction(signal, &sa, NULL);
1809 interrupt_low_level_handlers[signal] =
1810 (ARE_SAME_HANDLER(handler, SIG_DFL) ? 0 : handler);
1814 /* This is called from Lisp. */
1816 install_handler(int signal, void handler(int, siginfo_t*, os_context_t*))
1818 #ifndef LISP_FEATURE_WIN32
1819 struct sigaction sa;
1821 union interrupt_handler oldhandler;
1823 FSHOW((stderr, "/entering POSIX install_handler(%d, ..)\n", signal));
1825 block_blockable_signals(0, &old);
1827 FSHOW((stderr, "/interrupt_low_level_handlers[signal]=%x\n",
1828 (unsigned int)interrupt_low_level_handlers[signal]));
1829 if (interrupt_low_level_handlers[signal]==0) {
1830 if (ARE_SAME_HANDLER(handler, SIG_DFL) ||
1831 ARE_SAME_HANDLER(handler, SIG_IGN))
1832 sa.sa_sigaction = (void (*)(int, siginfo_t*, void*))handler;
1833 else if (sigismember(&deferrable_sigset, signal))
1834 sa.sa_sigaction = maybe_now_maybe_later;
1835 else if (!sigaction_nodefer_works &&
1836 !sigismember(&blockable_sigset, signal))
1837 sa.sa_sigaction = unblock_me_trampoline;
1839 sa.sa_sigaction = interrupt_handle_now_handler;
1841 sigcopyset(&sa.sa_mask, &blockable_sigset);
1842 sa.sa_flags = SA_SIGINFO | SA_RESTART |
1843 (sigaction_nodefer_works ? SA_NODEFER : 0);
1844 sigaction(signal, &sa, NULL);
1847 oldhandler = interrupt_handlers[signal];
1848 interrupt_handlers[signal].c = handler;
1850 thread_sigmask(SIG_SETMASK, &old, 0);
1852 FSHOW((stderr, "/leaving POSIX install_handler(%d, ..)\n", signal));
1854 return (unsigned long)oldhandler.lisp;
1856 /* Probably-wrong Win32 hack */
1861 /* This must not go through lisp as it's allowed anytime, even when on
1864 sigabrt_handler(int signal, siginfo_t *info, os_context_t *context)
1866 lose("SIGABRT received.\n");
1870 interrupt_init(void)
1872 #ifndef LISP_FEATURE_WIN32
1874 SHOW("entering interrupt_init()");
1875 see_if_sigaction_nodefer_works();
1876 sigemptyset(&deferrable_sigset);
1877 sigemptyset(&blockable_sigset);
1878 sigemptyset(&gc_sigset);
1879 sigaddset_deferrable(&deferrable_sigset);
1880 sigaddset_blockable(&blockable_sigset);
1881 sigaddset_gc(&gc_sigset);
1883 /* Set up high level handler information. */
1884 for (i = 0; i < NSIG; i++) {
1885 interrupt_handlers[i].c =
1886 /* (The cast here blasts away the distinction between
1887 * SA_SIGACTION-style three-argument handlers and
1888 * signal(..)-style one-argument handlers, which is OK
1889 * because it works to call the 1-argument form where the
1890 * 3-argument form is expected.) */
1891 (void (*)(int, siginfo_t*, os_context_t*))SIG_DFL;
1893 undoably_install_low_level_interrupt_handler(SIGABRT, sigabrt_handler);
1894 SHOW("returning from interrupt_init()");
1898 #ifndef LISP_FEATURE_WIN32
1900 siginfo_code(siginfo_t *info)
1902 return info->si_code;
1904 os_vm_address_t current_memory_fault_address;
1907 lisp_memory_fault_error(os_context_t *context, os_vm_address_t addr)
1909 /* FIXME: This is lossy: if we get another memory fault (eg. from
1910 * another thread) before lisp has read this, we lose the information.
1911 * However, since this is mostly informative, we'll live with that for
1912 * now -- some address is better then no address in this case.
1914 current_memory_fault_address = addr;
1915 /* To allow debugging memory faults in signal handlers and such. */
1916 corruption_warning_and_maybe_lose("Memory fault at %x (pc=%p, sp=%p)",
1918 *os_context_pc_addr(context),
1919 #ifdef ARCH_HAS_STACK_POINTER
1920 *os_context_sp_addr(context)
1925 unblock_signals_in_context_and_maybe_warn(context);
1926 #ifdef LISP_FEATURE_C_STACK_IS_CONTROL_STACK
1927 arrange_return_to_lisp_function(context,
1928 StaticSymbolFunction(MEMORY_FAULT_ERROR));
1930 funcall0(StaticSymbolFunction(MEMORY_FAULT_ERROR));
1936 unhandled_trap_error(os_context_t *context)
1938 lispobj context_sap;
1939 fake_foreign_function_call(context);
1940 #ifndef LISP_FEATURE_SB_SAFEPOINT
1941 unblock_gc_signals(0, 0);
1943 context_sap = alloc_sap(context);
1944 #ifndef LISP_FEATURE_WIN32
1945 thread_sigmask(SIG_SETMASK, os_context_sigmask_addr(context), 0);
1947 funcall1(StaticSymbolFunction(UNHANDLED_TRAP_ERROR), context_sap);
1948 lose("UNHANDLED-TRAP-ERROR fell through");
1951 /* Common logic for trapping instructions. How we actually handle each
1952 * case is highly architecture dependent, but the overall shape is
1955 handle_trap(os_context_t *context, int trap)
1958 case trap_PendingInterrupt:
1959 FSHOW((stderr, "/<trap pending interrupt>\n"));
1960 arch_skip_instruction(context);
1961 interrupt_handle_pending(context);
1965 FSHOW((stderr, "/<trap error/cerror %d>\n", trap));
1966 interrupt_internal_error(context, trap==trap_Cerror);
1968 case trap_Breakpoint:
1969 arch_handle_breakpoint(context);
1971 case trap_FunEndBreakpoint:
1972 arch_handle_fun_end_breakpoint(context);
1974 #ifdef trap_AfterBreakpoint
1975 case trap_AfterBreakpoint:
1976 arch_handle_after_breakpoint(context);
1979 #ifdef trap_SingleStepAround
1980 case trap_SingleStepAround:
1981 case trap_SingleStepBefore:
1982 arch_handle_single_step_trap(context, trap);
1985 #ifdef LISP_FEATURE_SB_SAFEPOINT
1986 case trap_GlobalSafepoint:
1987 fake_foreign_function_call(context);
1988 thread_in_lisp_raised(context);
1989 undo_fake_foreign_function_call(context);
1990 arch_skip_instruction(context);
1992 case trap_CspSafepoint:
1993 fake_foreign_function_call(context);
1994 thread_in_safety_transition(context);
1995 undo_fake_foreign_function_call(context);
1996 arch_skip_instruction(context);
2000 fake_foreign_function_call(context);
2001 lose("%%PRIMITIVE HALT called; the party is over.\n");
2003 unhandled_trap_error(context);