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 LISP_FEATURE_SB_THREAD
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 #if !defined(LISP_FEATURE_WIN32)
371 gc_signals_blocked_p(sigset_t *sigset)
373 return all_signals_blocked_p(sigset, &gc_sigset, "gc");
378 check_gc_signals_unblocked_or_lose(sigset_t *sigset)
380 #if !defined(LISP_FEATURE_WIN32)
381 if (gc_signals_blocked_p(sigset))
382 lose("gc signals blocked\n");
387 check_gc_signals_blocked_or_lose(sigset_t *sigset)
389 #if !defined(LISP_FEATURE_WIN32)
390 if (!gc_signals_blocked_p(sigset))
391 lose("gc signals unblocked\n");
396 block_deferrable_signals(sigset_t *where, sigset_t *old)
398 #ifndef LISP_FEATURE_WIN32
399 block_signals(&deferrable_sigset, where, old);
404 block_blockable_signals(sigset_t *where, sigset_t *old)
406 #ifndef LISP_FEATURE_WIN32
407 block_signals(&blockable_sigset, where, old);
412 block_gc_signals(sigset_t *where, sigset_t *old)
414 #ifndef LISP_FEATURE_WIN32
415 block_signals(&gc_sigset, where, old);
420 unblock_deferrable_signals(sigset_t *where, sigset_t *old)
422 #ifndef LISP_FEATURE_WIN32
423 if (interrupt_handler_pending_p())
424 lose("unblock_deferrable_signals: losing proposition\n");
425 check_gc_signals_unblocked_or_lose(where);
426 unblock_signals(&deferrable_sigset, where, old);
431 unblock_blockable_signals(sigset_t *where, sigset_t *old)
433 #ifndef LISP_FEATURE_WIN32
434 unblock_signals(&blockable_sigset, where, old);
439 unblock_gc_signals(sigset_t *where, sigset_t *old)
441 #ifndef LISP_FEATURE_WIN32
442 unblock_signals(&gc_sigset, where, old);
447 unblock_signals_in_context_and_maybe_warn(os_context_t *context)
449 #ifndef LISP_FEATURE_WIN32
450 sigset_t *sigset = os_context_sigmask_addr(context);
451 if (all_signals_blocked_p(sigset, &gc_sigset, "gc")) {
452 corruption_warning_and_maybe_lose(
453 "Enabling blocked gc signals to allow returning to Lisp without risking\n\
454 gc deadlocks. Since GC signals are only blocked in signal handlers when \n\
455 they are not safe to interrupt at all, this is a pretty severe occurrence.\n");
456 unblock_gc_signals(sigset, 0);
458 if (!interrupt_handler_pending_p()) {
459 unblock_deferrable_signals(sigset, 0);
466 check_interrupts_enabled_or_lose(os_context_t *context)
468 struct thread *thread=arch_os_get_current_thread();
469 if (SymbolValue(INTERRUPTS_ENABLED,thread) == NIL)
470 lose("interrupts not enabled\n");
471 if (arch_pseudo_atomic_atomic(context))
472 lose ("in pseudo atomic section\n");
475 /* Save sigset (or the current sigmask if 0) if there is no pending
476 * handler, because that means that deferabbles are already blocked.
477 * The purpose is to avoid losing the pending gc signal if a
478 * deferrable interrupt async unwinds between clearing the pseudo
479 * atomic and trapping to GC.*/
481 maybe_save_gc_mask_and_block_deferrables(sigset_t *sigset)
483 #ifndef LISP_FEATURE_WIN32
484 struct thread *thread = arch_os_get_current_thread();
485 struct interrupt_data *data = thread->interrupt_data;
487 /* Obviously, this function is called when signals may not be
488 * blocked. Let's make sure we are not interrupted. */
489 block_blockable_signals(0, &oldset);
490 #ifndef LISP_FEATURE_SB_THREAD
491 /* With threads a SIG_STOP_FOR_GC and a normal GC may also want to
493 if (data->gc_blocked_deferrables)
494 lose("gc_blocked_deferrables already true\n");
496 if ((!data->pending_handler) &&
497 (!data->gc_blocked_deferrables)) {
498 FSHOW_SIGNAL((stderr,"/setting gc_blocked_deferrables\n"));
499 data->gc_blocked_deferrables = 1;
501 /* This is the sigmask of some context. */
502 sigcopyset(&data->pending_mask, sigset);
503 sigaddset_deferrable(sigset);
504 thread_sigmask(SIG_SETMASK,&oldset,0);
507 /* Operating on the current sigmask. Save oldset and
508 * unblock gc signals. In the end, this is equivalent to
509 * blocking the deferrables. */
510 sigcopyset(&data->pending_mask, &oldset);
511 thread_sigmask(SIG_UNBLOCK, &gc_sigset, 0);
515 thread_sigmask(SIG_SETMASK,&oldset,0);
519 /* Are we leaving WITH-GCING and already running with interrupts
520 * enabled, without the protection of *GC-INHIBIT* T and there is gc
521 * (or stop for gc) pending, but we haven't trapped yet? */
523 in_leaving_without_gcing_race_p(struct thread *thread)
525 return ((SymbolValue(IN_WITHOUT_GCING,thread) != NIL) &&
526 (SymbolValue(INTERRUPTS_ENABLED,thread) != NIL) &&
527 (SymbolValue(GC_INHIBIT,thread) == NIL) &&
528 ((SymbolValue(GC_PENDING,thread) != NIL)
529 #if defined(LISP_FEATURE_SB_THREAD)
530 || (SymbolValue(STOP_FOR_GC_PENDING,thread) != NIL)
535 /* Check our baroque invariants. */
537 check_interrupt_context_or_lose(os_context_t *context)
539 #ifndef LISP_FEATURE_WIN32
540 struct thread *thread = arch_os_get_current_thread();
541 struct interrupt_data *data = thread->interrupt_data;
542 int interrupt_deferred_p = (data->pending_handler != 0);
543 int interrupt_pending = (SymbolValue(INTERRUPT_PENDING,thread) != NIL);
544 sigset_t *sigset = os_context_sigmask_addr(context);
545 /* On PPC pseudo_atomic_interrupted is cleared when coming out of
546 * handle_allocation_trap. */
547 #if defined(LISP_FEATURE_GENCGC) && !defined(LISP_FEATURE_PPC)
548 int interrupts_enabled = (SymbolValue(INTERRUPTS_ENABLED,thread) != NIL);
549 int gc_inhibit = (SymbolValue(GC_INHIBIT,thread) != NIL);
550 int gc_pending = (SymbolValue(GC_PENDING,thread) == T);
551 int pseudo_atomic_interrupted = get_pseudo_atomic_interrupted(thread);
552 int in_race_p = in_leaving_without_gcing_race_p(thread);
553 /* In the time window between leaving the *INTERRUPTS-ENABLED* NIL
554 * section and trapping, a SIG_STOP_FOR_GC would see the next
555 * check fail, for this reason sig_stop_for_gc handler does not
556 * call this function. */
557 if (interrupt_deferred_p) {
558 if (!(!interrupts_enabled || pseudo_atomic_interrupted || in_race_p))
559 lose("Stray deferred interrupt.\n");
562 if (!(pseudo_atomic_interrupted || gc_inhibit || in_race_p))
563 lose("GC_PENDING, but why?\n");
564 #if defined(LISP_FEATURE_SB_THREAD)
566 int stop_for_gc_pending =
567 (SymbolValue(STOP_FOR_GC_PENDING,thread) != NIL);
568 if (stop_for_gc_pending)
569 if (!(pseudo_atomic_interrupted || gc_inhibit || in_race_p))
570 lose("STOP_FOR_GC_PENDING, but why?\n");
571 if (pseudo_atomic_interrupted)
572 if (!(gc_pending || stop_for_gc_pending || interrupt_deferred_p))
573 lose("pseudo_atomic_interrupted, but why?\n");
576 if (pseudo_atomic_interrupted)
577 if (!(gc_pending || interrupt_deferred_p))
578 lose("pseudo_atomic_interrupted, but why?\n");
581 if (interrupt_pending && !interrupt_deferred_p)
582 lose("INTERRUPT_PENDING but not pending handler.\n");
583 if ((data->gc_blocked_deferrables) && interrupt_pending)
584 lose("gc_blocked_deferrables and interrupt pending\n.");
585 if (data->gc_blocked_deferrables)
586 check_deferrables_blocked_or_lose(sigset);
587 if (interrupt_pending || interrupt_deferred_p ||
588 data->gc_blocked_deferrables)
589 check_deferrables_blocked_or_lose(sigset);
591 check_deferrables_unblocked_or_lose(sigset);
592 /* If deferrables are unblocked then we are open to signals
593 * that run lisp code. */
594 check_gc_signals_unblocked_or_lose(sigset);
600 * utility routines used by various signal handlers
604 build_fake_control_stack_frames(struct thread *th,os_context_t *context)
606 #ifndef LISP_FEATURE_C_STACK_IS_CONTROL_STACK
610 /* Build a fake stack frame or frames */
612 current_control_frame_pointer =
613 (lispobj *)(unsigned long)
614 (*os_context_register_addr(context, reg_CSP));
615 if ((lispobj *)(unsigned long)
616 (*os_context_register_addr(context, reg_CFP))
617 == current_control_frame_pointer) {
618 /* There is a small window during call where the callee's
619 * frame isn't built yet. */
620 if (lowtag_of(*os_context_register_addr(context, reg_CODE))
621 == FUN_POINTER_LOWTAG) {
622 /* We have called, but not built the new frame, so
623 * build it for them. */
624 current_control_frame_pointer[0] =
625 *os_context_register_addr(context, reg_OCFP);
626 current_control_frame_pointer[1] =
627 *os_context_register_addr(context, reg_LRA);
628 current_control_frame_pointer += 8;
629 /* Build our frame on top of it. */
630 oldcont = (lispobj)(*os_context_register_addr(context, reg_CFP));
633 /* We haven't yet called, build our frame as if the
634 * partial frame wasn't there. */
635 oldcont = (lispobj)(*os_context_register_addr(context, reg_OCFP));
638 /* We can't tell whether we are still in the caller if it had to
639 * allocate a stack frame due to stack arguments. */
640 /* This observation provoked some past CMUCL maintainer to ask
641 * "Can anything strange happen during return?" */
644 oldcont = (lispobj)(*os_context_register_addr(context, reg_CFP));
647 current_control_stack_pointer = current_control_frame_pointer + 8;
649 current_control_frame_pointer[0] = oldcont;
650 current_control_frame_pointer[1] = NIL;
651 current_control_frame_pointer[2] =
652 (lispobj)(*os_context_register_addr(context, reg_CODE));
656 /* Stores the context for gc to scavange and builds fake stack
659 fake_foreign_function_call(os_context_t *context)
662 struct thread *thread=arch_os_get_current_thread();
664 /* context_index incrementing must not be interrupted */
665 check_blockables_blocked_or_lose(0);
667 /* Get current Lisp state from context. */
669 #ifdef LISP_FEATURE_SB_THREAD
670 thread->pseudo_atomic_bits =
672 dynamic_space_free_pointer =
673 (lispobj *)(unsigned long)
675 (*os_context_register_addr(context, reg_ALLOC));
676 /* fprintf(stderr,"dynamic_space_free_pointer: %p\n", */
677 /* dynamic_space_free_pointer); */
678 #if defined(LISP_FEATURE_ALPHA) || defined(LISP_FEATURE_MIPS)
679 if ((long)dynamic_space_free_pointer & 1) {
680 lose("dead in fake_foreign_function_call, context = %x\n", context);
683 /* why doesnt PPC and SPARC do something like this: */
684 #if defined(LISP_FEATURE_HPPA)
685 if ((long)dynamic_space_free_pointer & 4) {
686 lose("dead in fake_foreign_function_call, context = %x, d_s_f_p = %x\n", context, dynamic_space_free_pointer);
691 current_binding_stack_pointer =
692 (lispobj *)(unsigned long)
693 (*os_context_register_addr(context, reg_BSP));
696 build_fake_control_stack_frames(thread,context);
698 /* Do dynamic binding of the active interrupt context index
699 * and save the context in the context array. */
701 fixnum_value(SymbolValue(FREE_INTERRUPT_CONTEXT_INDEX,thread));
703 if (context_index >= MAX_INTERRUPTS) {
704 lose("maximum interrupt nesting depth (%d) exceeded\n", MAX_INTERRUPTS);
707 bind_variable(FREE_INTERRUPT_CONTEXT_INDEX,
708 make_fixnum(context_index + 1),thread);
710 thread->interrupt_contexts[context_index] = context;
712 #if !defined(LISP_FEATURE_X86) && !defined(LISP_FEATURE_X86_64)
713 /* x86oid targets don't maintain the foreign function call flag at
714 * all, so leave them to believe that they are never in foreign
716 foreign_function_call_active_p(thread) = 1;
720 /* blocks all blockable signals. If you are calling from a signal handler,
721 * the usual signal mask will be restored from the context when the handler
722 * finishes. Otherwise, be careful */
724 undo_fake_foreign_function_call(os_context_t *context)
726 struct thread *thread=arch_os_get_current_thread();
727 /* Block all blockable signals. */
728 block_blockable_signals(0, 0);
730 foreign_function_call_active_p(thread) = 0;
732 /* Undo dynamic binding of FREE_INTERRUPT_CONTEXT_INDEX */
735 #if defined(reg_ALLOC) && !defined(LISP_FEATURE_SB_THREAD)
736 /* Put the dynamic space free pointer back into the context. */
737 *os_context_register_addr(context, reg_ALLOC) =
738 (unsigned long) dynamic_space_free_pointer
739 | (*os_context_register_addr(context, reg_ALLOC)
742 ((unsigned long)(*os_context_register_addr(context, reg_ALLOC))
744 | ((unsigned long) dynamic_space_free_pointer & LOWTAG_MASK);
747 #if defined(reg_ALLOC) && defined(LISP_FEATURE_SB_THREAD)
748 /* Put the pseudo-atomic bits and dynamic space free pointer back
749 * into the context (p-a-bits for p-a, and dynamic space free
750 * pointer for ROOM). */
751 *os_context_register_addr(context, reg_ALLOC) =
752 (unsigned long) dynamic_space_free_pointer
753 | (thread->pseudo_atomic_bits & LOWTAG_MASK);
754 /* And clear them so we don't get bit later by call-in/call-out
755 * not updating them. */
756 thread->pseudo_atomic_bits = 0;
760 /* a handler for the signal caused by execution of a trap opcode
761 * signalling an internal error */
763 interrupt_internal_error(os_context_t *context, boolean continuable)
767 fake_foreign_function_call(context);
769 if (!internal_errors_enabled) {
770 describe_internal_error(context);
771 /* There's no good way to recover from an internal error
772 * before the Lisp error handling mechanism is set up. */
773 lose("internal error too early in init, can't recover\n");
776 /* Allocate the SAP object while the interrupts are still
778 unblock_gc_signals(0, 0);
779 context_sap = alloc_sap(context);
781 #ifndef LISP_FEATURE_WIN32
782 thread_sigmask(SIG_SETMASK, os_context_sigmask_addr(context), 0);
785 #if defined(LISP_FEATURE_LINUX) && defined(LISP_FEATURE_MIPS)
786 /* Workaround for blocked SIGTRAP. */
789 sigemptyset(&newset);
790 sigaddset(&newset, SIGTRAP);
791 thread_sigmask(SIG_UNBLOCK, &newset, 0);
795 SHOW("in interrupt_internal_error");
797 /* Display some rudimentary debugging information about the
798 * error, so that even if the Lisp error handler gets badly
799 * confused, we have a chance to determine what's going on. */
800 describe_internal_error(context);
802 funcall2(StaticSymbolFunction(INTERNAL_ERROR), context_sap,
803 continuable ? T : NIL);
805 undo_fake_foreign_function_call(context); /* blocks signals again */
807 arch_skip_instruction(context);
811 interrupt_handler_pending_p(void)
813 struct thread *thread = arch_os_get_current_thread();
814 struct interrupt_data *data = thread->interrupt_data;
815 return (data->pending_handler != 0);
819 interrupt_handle_pending(os_context_t *context)
821 /* There are three ways we can get here. First, if an interrupt
822 * occurs within pseudo-atomic, it will be deferred, and we'll
823 * trap to here at the end of the pseudo-atomic block. Second, if
824 * the GC (in alloc()) decides that a GC is required, it will set
825 * *GC-PENDING* and pseudo-atomic-interrupted if not *GC-INHIBIT*,
826 * and alloc() is always called from within pseudo-atomic, and
827 * thus we end up here again. Third, when calling GC-ON or at the
828 * end of a WITHOUT-GCING, MAYBE-HANDLE-PENDING-GC will trap to
829 * here if there is a pending GC. Fourth, ahem, at the end of
830 * WITHOUT-INTERRUPTS (bar complications with nesting). */
832 /* Win32 only needs to handle the GC cases (for now?) */
834 struct thread *thread = arch_os_get_current_thread();
835 struct interrupt_data *data = thread->interrupt_data;
837 if (arch_pseudo_atomic_atomic(context)) {
838 lose("Handling pending interrupt in pseudo atomic.");
841 FSHOW_SIGNAL((stderr, "/entering interrupt_handle_pending\n"));
843 check_blockables_blocked_or_lose(0);
845 /* If GC/SIG_STOP_FOR_GC struck during PA and there was no pending
846 * handler, then the pending mask was saved and
847 * gc_blocked_deferrables set. Hence, there can be no pending
848 * handler and it's safe to restore the pending mask.
850 * Note, that if gc_blocked_deferrables is false we may still have
851 * to GC. In this case, we are coming out of a WITHOUT-GCING or a
852 * pseudo atomic was interrupt be a deferrable first. */
853 if (data->gc_blocked_deferrables) {
854 if (data->pending_handler)
855 lose("GC blocked deferrables but still got a pending handler.");
856 if (SymbolValue(GC_INHIBIT,thread)!=NIL)
857 lose("GC blocked deferrables while GC is inhibited.");
858 /* Restore the saved signal mask from the original signal (the
859 * one that interrupted us during the critical section) into
860 * the os_context for the signal we're currently in the
861 * handler for. This should ensure that when we return from
862 * the handler the blocked signals are unblocked. */
863 #ifndef LISP_FEATURE_WIN32
864 sigcopyset(os_context_sigmask_addr(context), &data->pending_mask);
866 data->gc_blocked_deferrables = 0;
869 if (SymbolValue(GC_INHIBIT,thread)==NIL) {
870 void *original_pending_handler = data->pending_handler;
872 #ifdef LISP_FEATURE_SB_THREAD
873 if (SymbolValue(STOP_FOR_GC_PENDING,thread) != NIL) {
874 /* STOP_FOR_GC_PENDING and GC_PENDING are cleared by
875 * the signal handler if it actually stops us. */
876 arch_clear_pseudo_atomic_interrupted(context);
877 sig_stop_for_gc_handler(SIG_STOP_FOR_GC,NULL,context);
880 /* Test for T and not for != NIL since the value :IN-PROGRESS
881 * is used in SUB-GC as part of the mechanism to supress
883 if (SymbolValue(GC_PENDING,thread) == T) {
885 /* Two reasons for doing this. First, if there is a
886 * pending handler we don't want to run. Second, we are
887 * going to clear pseudo atomic interrupted to avoid
888 * spurious trapping on every allocation in SUB_GC and
889 * having a pending handler with interrupts enabled and
890 * without pseudo atomic interrupted breaks an
892 if (data->pending_handler) {
893 bind_variable(ALLOW_WITH_INTERRUPTS, NIL, thread);
894 bind_variable(INTERRUPTS_ENABLED, NIL, thread);
897 arch_clear_pseudo_atomic_interrupted(context);
899 /* GC_PENDING is cleared in SUB-GC, or if another thread
900 * is doing a gc already we will get a SIG_STOP_FOR_GC and
901 * that will clear it.
903 * If there is a pending handler or gc was triggerred in a
904 * signal handler then maybe_gc won't run POST_GC and will
905 * return normally. */
906 if (!maybe_gc(context))
907 lose("GC not inhibited but maybe_gc did not GC.");
909 if (data->pending_handler) {
913 } else if (SymbolValue(GC_PENDING,thread) != NIL) {
914 /* It's not NIL or T so GC_PENDING is :IN-PROGRESS. If
915 * GC-PENDING is not NIL then we cannot trap on pseudo
916 * atomic due to GC (see if(GC_PENDING) logic in
917 * cheneygc.c an gengcgc.c), plus there is a outer
918 * WITHOUT-INTERRUPTS SUB_GC, so how did we end up
920 lose("Trapping to run pending handler while GC in progress.");
923 check_blockables_blocked_or_lose(0);
925 /* No GC shall be lost. If SUB_GC triggers another GC then
926 * that should be handled on the spot. */
927 if (SymbolValue(GC_PENDING,thread) != NIL)
928 lose("GC_PENDING after doing gc.");
929 #ifdef LISP_FEATURE_SB_THREAD
930 if (SymbolValue(STOP_FOR_GC_PENDING,thread) != NIL)
931 lose("STOP_FOR_GC_PENDING after doing gc.");
933 /* Check two things. First, that gc does not clobber a handler
934 * that's already pending. Second, that there is no interrupt
935 * lossage: if original_pending_handler was NULL then even if
936 * an interrupt arrived during GC (POST-GC, really) it was
938 if (original_pending_handler != data->pending_handler)
939 lose("pending handler changed in gc: %x -> %d.",
940 original_pending_handler, data->pending_handler);
943 #ifndef LISP_FEATURE_WIN32
944 /* There may be no pending handler, because it was only a gc that
945 * had to be executed or because Lisp is a bit too eager to call
946 * DO-PENDING-INTERRUPT. */
947 if ((SymbolValue(INTERRUPTS_ENABLED,thread) != NIL) &&
948 (data->pending_handler)) {
949 /* No matter how we ended up here, clear both
950 * INTERRUPT_PENDING and pseudo atomic interrupted. It's safe
951 * because we checked above that there is no GC pending. */
952 SetSymbolValue(INTERRUPT_PENDING, NIL, thread);
953 arch_clear_pseudo_atomic_interrupted(context);
954 /* Restore the sigmask in the context. */
955 sigcopyset(os_context_sigmask_addr(context), &data->pending_mask);
956 run_deferred_handler(data, context);
959 #ifdef LISP_FEATURE_GENCGC
960 if (get_pseudo_atomic_interrupted(thread))
961 lose("pseudo_atomic_interrupted after interrupt_handle_pending\n");
963 /* It is possible that the end of this function was reached
964 * without never actually doing anything, the tests in Lisp for
965 * when to call receive-pending-interrupt are not exact. */
966 FSHOW_SIGNAL((stderr, "/exiting interrupt_handle_pending\n"));
971 interrupt_handle_now(int signal, siginfo_t *info, os_context_t *context)
973 boolean were_in_lisp;
974 union interrupt_handler handler;
976 check_blockables_blocked_or_lose(0);
978 #ifndef LISP_FEATURE_WIN32
979 if (sigismember(&deferrable_sigset,signal))
980 check_interrupts_enabled_or_lose(context);
983 handler = interrupt_handlers[signal];
985 if (ARE_SAME_HANDLER(handler.c, SIG_IGN)) {
989 were_in_lisp = !foreign_function_call_active_p(arch_os_get_current_thread());
992 fake_foreign_function_call(context);
995 FSHOW_SIGNAL((stderr,
996 "/entering interrupt_handle_now(%d, info, context)\n",
999 if (ARE_SAME_HANDLER(handler.c, SIG_DFL)) {
1001 /* This can happen if someone tries to ignore or default one
1002 * of the signals we need for runtime support, and the runtime
1003 * support decides to pass on it. */
1004 lose("no handler for signal %d in interrupt_handle_now(..)\n", signal);
1006 } else if (lowtag_of(handler.lisp) == FUN_POINTER_LOWTAG) {
1007 /* Once we've decided what to do about contexts in a
1008 * return-elsewhere world (the original context will no longer
1009 * be available; should we copy it or was nobody using it anyway?)
1010 * then we should convert this to return-elsewhere */
1012 /* CMUCL comment said "Allocate the SAPs while the interrupts
1013 * are still disabled.". I (dan, 2003.08.21) assume this is
1014 * because we're not in pseudoatomic and allocation shouldn't
1015 * be interrupted. In which case it's no longer an issue as
1016 * all our allocation from C now goes through a PA wrapper,
1017 * but still, doesn't hurt.
1019 * Yeah, but non-gencgc platforms don't really wrap allocation
1020 * in PA. MG - 2005-08-29 */
1022 lispobj info_sap, context_sap;
1023 /* Leave deferrable signals blocked, the handler itself will
1024 * allow signals again when it sees fit. */
1025 unblock_gc_signals(0, 0);
1026 context_sap = alloc_sap(context);
1027 info_sap = alloc_sap(info);
1029 FSHOW_SIGNAL((stderr,"/calling Lisp-level handler\n"));
1031 funcall3(handler.lisp,
1032 make_fixnum(signal),
1036 /* This cannot happen in sane circumstances. */
1038 FSHOW_SIGNAL((stderr,"/calling C-level handler\n"));
1040 #ifndef LISP_FEATURE_WIN32
1041 /* Allow signals again. */
1042 thread_sigmask(SIG_SETMASK, os_context_sigmask_addr(context), 0);
1044 (*handler.c)(signal, info, context);
1049 undo_fake_foreign_function_call(context); /* block signals again */
1052 FSHOW_SIGNAL((stderr,
1053 "/returning from interrupt_handle_now(%d, info, context)\n",
1057 /* This is called at the end of a critical section if the indications
1058 * are that some signal was deferred during the section. Note that as
1059 * far as C or the kernel is concerned we dealt with the signal
1060 * already; we're just doing the Lisp-level processing now that we
1063 run_deferred_handler(struct interrupt_data *data, os_context_t *context)
1065 /* The pending_handler may enable interrupts and then another
1066 * interrupt may hit, overwrite interrupt_data, so reset the
1067 * pending handler before calling it. Trust the handler to finish
1068 * with the siginfo before enabling interrupts. */
1069 void (*pending_handler) (int, siginfo_t*, os_context_t*) =
1070 data->pending_handler;
1072 data->pending_handler=0;
1073 FSHOW_SIGNAL((stderr, "/running deferred handler %p\n", pending_handler));
1074 (*pending_handler)(data->pending_signal,&(data->pending_info), context);
1077 #ifndef LISP_FEATURE_WIN32
1079 maybe_defer_handler(void *handler, struct interrupt_data *data,
1080 int signal, siginfo_t *info, os_context_t *context)
1082 struct thread *thread=arch_os_get_current_thread();
1084 check_blockables_blocked_or_lose(0);
1086 if (SymbolValue(INTERRUPT_PENDING,thread) != NIL)
1087 lose("interrupt already pending\n");
1088 if (thread->interrupt_data->pending_handler)
1089 lose("there is a pending handler already (PA)\n");
1090 if (data->gc_blocked_deferrables)
1091 lose("maybe_defer_handler: gc_blocked_deferrables true\n");
1092 check_interrupt_context_or_lose(context);
1093 /* If interrupts are disabled then INTERRUPT_PENDING is set and
1094 * not PSEDUO_ATOMIC_INTERRUPTED. This is important for a pseudo
1095 * atomic section inside a WITHOUT-INTERRUPTS.
1097 * Also, if in_leaving_without_gcing_race_p then
1098 * interrupt_handle_pending is going to be called soon, so
1099 * stashing the signal away is safe.
1101 if ((SymbolValue(INTERRUPTS_ENABLED,thread) == NIL) ||
1102 in_leaving_without_gcing_race_p(thread)) {
1103 FSHOW_SIGNAL((stderr,
1104 "/maybe_defer_handler(%x,%d): deferred (RACE=%d)\n",
1105 (unsigned int)handler,signal,
1106 in_leaving_without_gcing_race_p(thread)));
1107 store_signal_data_for_later(data,handler,signal,info,context);
1108 SetSymbolValue(INTERRUPT_PENDING, T,thread);
1109 check_interrupt_context_or_lose(context);
1112 /* a slightly confusing test. arch_pseudo_atomic_atomic() doesn't
1113 * actually use its argument for anything on x86, so this branch
1114 * may succeed even when context is null (gencgc alloc()) */
1115 if (arch_pseudo_atomic_atomic(context)) {
1116 FSHOW_SIGNAL((stderr,
1117 "/maybe_defer_handler(%x,%d): deferred(PA)\n",
1118 (unsigned int)handler,signal));
1119 store_signal_data_for_later(data,handler,signal,info,context);
1120 arch_set_pseudo_atomic_interrupted(context);
1121 check_interrupt_context_or_lose(context);
1124 FSHOW_SIGNAL((stderr,
1125 "/maybe_defer_handler(%x,%d): not deferred\n",
1126 (unsigned int)handler,signal));
1131 store_signal_data_for_later (struct interrupt_data *data, void *handler,
1133 siginfo_t *info, os_context_t *context)
1135 if (data->pending_handler)
1136 lose("tried to overwrite pending interrupt handler %x with %x\n",
1137 data->pending_handler, handler);
1139 lose("tried to defer null interrupt handler\n");
1140 data->pending_handler = handler;
1141 data->pending_signal = signal;
1143 memcpy(&(data->pending_info), info, sizeof(siginfo_t));
1145 FSHOW_SIGNAL((stderr, "/store_signal_data_for_later: signal: %d\n",
1149 lose("Null context");
1151 /* the signal mask in the context (from before we were
1152 * interrupted) is copied to be restored when run_deferred_handler
1153 * happens. Then the usually-blocked signals are added to the mask
1154 * in the context so that we are running with blocked signals when
1155 * the handler returns */
1156 sigcopyset(&(data->pending_mask),os_context_sigmask_addr(context));
1157 sigaddset_deferrable(os_context_sigmask_addr(context));
1161 maybe_now_maybe_later(int signal, siginfo_t *info, void *void_context)
1163 SAVE_ERRNO(signal,context,void_context);
1164 struct thread *thread = arch_os_get_current_thread();
1165 struct interrupt_data *data = thread->interrupt_data;
1166 if(!maybe_defer_handler(interrupt_handle_now,data,signal,info,context))
1167 interrupt_handle_now(signal, info, context);
1172 low_level_interrupt_handle_now(int signal, siginfo_t *info,
1173 os_context_t *context)
1175 /* No FP control fixage needed, caller has done that. */
1176 check_blockables_blocked_or_lose(0);
1177 check_interrupts_enabled_or_lose(context);
1178 (*interrupt_low_level_handlers[signal])(signal, info, context);
1179 /* No Darwin context fixage needed, caller does that. */
1183 low_level_maybe_now_maybe_later(int signal, siginfo_t *info, void *void_context)
1185 SAVE_ERRNO(signal,context,void_context);
1186 struct thread *thread = arch_os_get_current_thread();
1187 struct interrupt_data *data = thread->interrupt_data;
1189 if(!maybe_defer_handler(low_level_interrupt_handle_now,data,
1190 signal,info,context))
1191 low_level_interrupt_handle_now(signal, info, context);
1196 #ifdef LISP_FEATURE_SB_THREAD
1198 /* This function must not cons, because that may trigger a GC. */
1200 sig_stop_for_gc_handler(int signal, siginfo_t *info, os_context_t *context)
1202 struct thread *thread=arch_os_get_current_thread();
1203 boolean was_in_lisp;
1205 /* Test for GC_INHIBIT _first_, else we'd trap on every single
1206 * pseudo atomic until gc is finally allowed. */
1207 if (SymbolValue(GC_INHIBIT,thread) != NIL) {
1208 FSHOW_SIGNAL((stderr, "sig_stop_for_gc deferred (*GC-INHIBIT*)\n"));
1209 SetSymbolValue(STOP_FOR_GC_PENDING,T,thread);
1211 } else if (arch_pseudo_atomic_atomic(context)) {
1212 FSHOW_SIGNAL((stderr,"sig_stop_for_gc deferred (PA)\n"));
1213 SetSymbolValue(STOP_FOR_GC_PENDING,T,thread);
1214 arch_set_pseudo_atomic_interrupted(context);
1215 maybe_save_gc_mask_and_block_deferrables
1216 (os_context_sigmask_addr(context));
1220 FSHOW_SIGNAL((stderr, "/sig_stop_for_gc_handler\n"));
1222 /* Not PA and GC not inhibited -- we can stop now. */
1224 was_in_lisp = !foreign_function_call_active_p(arch_os_get_current_thread());
1227 /* need the context stored so it can have registers scavenged */
1228 fake_foreign_function_call(context);
1231 /* Not pending anymore. */
1232 SetSymbolValue(GC_PENDING,NIL,thread);
1233 SetSymbolValue(STOP_FOR_GC_PENDING,NIL,thread);
1235 /* Consider this: in a PA section GC is requested: GC_PENDING,
1236 * pseudo_atomic_interrupted and gc_blocked_deferrables are set,
1237 * deferrables are blocked then pseudo_atomic_atomic is cleared,
1238 * but a SIG_STOP_FOR_GC arrives before trapping to
1239 * interrupt_handle_pending. Here, GC_PENDING is cleared but
1240 * pseudo_atomic_interrupted is not and we go on running with
1241 * pseudo_atomic_interrupted but without a pending interrupt or
1242 * GC. GC_BLOCKED_DEFERRABLES is also left at 1. So let's tidy it
1244 if (thread->interrupt_data->gc_blocked_deferrables) {
1245 FSHOW_SIGNAL((stderr,"cleaning up after gc_blocked_deferrables\n"));
1246 clear_pseudo_atomic_interrupted(thread);
1247 sigcopyset(os_context_sigmask_addr(context),
1248 &thread->interrupt_data->pending_mask);
1249 thread->interrupt_data->gc_blocked_deferrables = 0;
1252 if(thread_state(thread)!=STATE_RUNNING) {
1253 lose("sig_stop_for_gc_handler: wrong thread state: %ld\n",
1254 fixnum_value(thread->state));
1257 set_thread_state(thread,STATE_SUSPENDED);
1258 FSHOW_SIGNAL((stderr,"suspended\n"));
1260 /* While waiting for gc to finish occupy ourselves with zeroing
1261 * the unused portion of the control stack to reduce conservatism.
1262 * On hypothetic platforms with threads and exact gc it is
1263 * actually a must. */
1264 scrub_control_stack();
1266 wait_for_thread_state_change(thread, STATE_SUSPENDED);
1267 FSHOW_SIGNAL((stderr,"resumed\n"));
1269 if(thread_state(thread)!=STATE_RUNNING) {
1270 lose("sig_stop_for_gc_handler: wrong thread state on wakeup: %ld\n",
1271 fixnum_value(thread_state(thread)));
1275 undo_fake_foreign_function_call(context);
1282 interrupt_handle_now_handler(int signal, siginfo_t *info, void *void_context)
1284 SAVE_ERRNO(signal,context,void_context);
1285 #ifndef LISP_FEATURE_WIN32
1286 if ((signal == SIGILL) || (signal == SIGBUS)
1287 #ifndef LISP_FEATURE_LINUX
1288 || (signal == SIGEMT)
1291 corruption_warning_and_maybe_lose("Signal %d received", signal);
1293 interrupt_handle_now(signal, info, context);
1297 /* manipulate the signal context and stack such that when the handler
1298 * returns, it will call function instead of whatever it was doing
1302 #if (defined(LISP_FEATURE_X86) || defined(LISP_FEATURE_X86_64))
1303 extern int *context_eflags_addr(os_context_t *context);
1306 extern lispobj call_into_lisp(lispobj fun, lispobj *args, int nargs);
1307 extern void post_signal_tramp(void);
1308 extern void call_into_lisp_tramp(void);
1310 arrange_return_to_lisp_function(os_context_t *context, lispobj function)
1312 #ifndef LISP_FEATURE_WIN32
1313 check_gc_signals_unblocked_or_lose
1314 (os_context_sigmask_addr(context));
1316 #if !(defined(LISP_FEATURE_X86) || defined(LISP_FEATURE_X86_64))
1317 void * fun=native_pointer(function);
1318 void *code = &(((struct simple_fun *) fun)->code);
1321 /* Build a stack frame showing `interrupted' so that the
1322 * user's backtrace makes (as much) sense (as usual) */
1324 /* fp state is saved and restored by call_into_lisp */
1325 /* FIXME: errno is not restored, but since current uses of this
1326 * function only call Lisp code that signals an error, it's not
1327 * much of a problem. In other words, running out of the control
1328 * stack between a syscall and (GET-ERRNO) may clobber errno if
1329 * something fails during signalling or in the handler. But I
1330 * can't see what can go wrong as long as there is no CONTINUE
1331 * like restart on them. */
1332 #ifdef LISP_FEATURE_X86
1333 /* Suppose the existence of some function that saved all
1334 * registers, called call_into_lisp, then restored GP registers and
1335 * returned. It would look something like this:
1343 pushl {address of function to call}
1344 call 0x8058db0 <call_into_lisp>
1351 * What we do here is set up the stack that call_into_lisp would
1352 * expect to see if it had been called by this code, and frob the
1353 * signal context so that signal return goes directly to call_into_lisp,
1354 * and when that function (and the lisp function it invoked) returns,
1355 * it returns to the second half of this imaginary function which
1356 * restores all registers and returns to C
1358 * For this to work, the latter part of the imaginary function
1359 * must obviously exist in reality. That would be post_signal_tramp
1362 u32 *sp=(u32 *)*os_context_register_addr(context,reg_ESP);
1364 #if defined(LISP_FEATURE_DARWIN)
1365 u32 *register_save_area = (u32 *)os_validate(0, 0x40);
1367 FSHOW_SIGNAL((stderr, "/arrange_return_to_lisp_function: preparing to go to function %x, sp: %x\n", function, sp));
1368 FSHOW_SIGNAL((stderr, "/arrange_return_to_lisp_function: context: %x, &context %x\n", context, &context));
1370 /* 1. os_validate (malloc/mmap) register_save_block
1371 * 2. copy register state into register_save_block
1372 * 3. put a pointer to register_save_block in a register in the context
1373 * 4. set the context's EIP to point to a trampoline which:
1374 * a. builds the fake stack frame from the block
1375 * b. frees the block
1376 * c. calls the function
1379 *register_save_area = *os_context_pc_addr(context);
1380 *(register_save_area + 1) = function;
1381 *(register_save_area + 2) = *os_context_register_addr(context,reg_EDI);
1382 *(register_save_area + 3) = *os_context_register_addr(context,reg_ESI);
1383 *(register_save_area + 4) = *os_context_register_addr(context,reg_EDX);
1384 *(register_save_area + 5) = *os_context_register_addr(context,reg_ECX);
1385 *(register_save_area + 6) = *os_context_register_addr(context,reg_EBX);
1386 *(register_save_area + 7) = *os_context_register_addr(context,reg_EAX);
1387 *(register_save_area + 8) = *context_eflags_addr(context);
1389 *os_context_pc_addr(context) =
1390 (os_context_register_t) call_into_lisp_tramp;
1391 *os_context_register_addr(context,reg_ECX) =
1392 (os_context_register_t) register_save_area;
1395 /* return address for call_into_lisp: */
1396 *(sp-15) = (u32)post_signal_tramp;
1397 *(sp-14) = function; /* args for call_into_lisp : function*/
1398 *(sp-13) = 0; /* arg array */
1399 *(sp-12) = 0; /* no. args */
1400 /* this order matches that used in POPAD */
1401 *(sp-11)=*os_context_register_addr(context,reg_EDI);
1402 *(sp-10)=*os_context_register_addr(context,reg_ESI);
1404 *(sp-9)=*os_context_register_addr(context,reg_ESP)-8;
1405 /* POPAD ignores the value of ESP: */
1407 *(sp-7)=*os_context_register_addr(context,reg_EBX);
1409 *(sp-6)=*os_context_register_addr(context,reg_EDX);
1410 *(sp-5)=*os_context_register_addr(context,reg_ECX);
1411 *(sp-4)=*os_context_register_addr(context,reg_EAX);
1412 *(sp-3)=*context_eflags_addr(context);
1413 *(sp-2)=*os_context_register_addr(context,reg_EBP);
1414 *(sp-1)=*os_context_pc_addr(context);
1418 #elif defined(LISP_FEATURE_X86_64)
1419 u64 *sp=(u64 *)*os_context_register_addr(context,reg_RSP);
1421 /* return address for call_into_lisp: */
1422 *(sp-18) = (u64)post_signal_tramp;
1424 *(sp-17)=*os_context_register_addr(context,reg_R15);
1425 *(sp-16)=*os_context_register_addr(context,reg_R14);
1426 *(sp-15)=*os_context_register_addr(context,reg_R13);
1427 *(sp-14)=*os_context_register_addr(context,reg_R12);
1428 *(sp-13)=*os_context_register_addr(context,reg_R11);
1429 *(sp-12)=*os_context_register_addr(context,reg_R10);
1430 *(sp-11)=*os_context_register_addr(context,reg_R9);
1431 *(sp-10)=*os_context_register_addr(context,reg_R8);
1432 *(sp-9)=*os_context_register_addr(context,reg_RDI);
1433 *(sp-8)=*os_context_register_addr(context,reg_RSI);
1434 /* skip RBP and RSP */
1435 *(sp-7)=*os_context_register_addr(context,reg_RBX);
1436 *(sp-6)=*os_context_register_addr(context,reg_RDX);
1437 *(sp-5)=*os_context_register_addr(context,reg_RCX);
1438 *(sp-4)=*os_context_register_addr(context,reg_RAX);
1439 *(sp-3)=*context_eflags_addr(context);
1440 *(sp-2)=*os_context_register_addr(context,reg_RBP);
1441 *(sp-1)=*os_context_pc_addr(context);
1443 *os_context_register_addr(context,reg_RDI) =
1444 (os_context_register_t)function; /* function */
1445 *os_context_register_addr(context,reg_RSI) = 0; /* arg. array */
1446 *os_context_register_addr(context,reg_RDX) = 0; /* no. args */
1448 struct thread *th=arch_os_get_current_thread();
1449 build_fake_control_stack_frames(th,context);
1452 #ifdef LISP_FEATURE_X86
1454 #if !defined(LISP_FEATURE_DARWIN)
1455 *os_context_pc_addr(context) = (os_context_register_t)call_into_lisp;
1456 *os_context_register_addr(context,reg_ECX) = 0;
1457 *os_context_register_addr(context,reg_EBP) = (os_context_register_t)(sp-2);
1459 *os_context_register_addr(context,reg_UESP) =
1460 (os_context_register_t)(sp-15);
1462 *os_context_register_addr(context,reg_ESP) = (os_context_register_t)(sp-15);
1463 #endif /* __NETBSD__ */
1464 #endif /* LISP_FEATURE_DARWIN */
1466 #elif defined(LISP_FEATURE_X86_64)
1467 *os_context_pc_addr(context) = (os_context_register_t)call_into_lisp;
1468 *os_context_register_addr(context,reg_RCX) = 0;
1469 *os_context_register_addr(context,reg_RBP) = (os_context_register_t)(sp-2);
1470 *os_context_register_addr(context,reg_RSP) = (os_context_register_t)(sp-18);
1472 /* this much of the calling convention is common to all
1474 *os_context_pc_addr(context) = (os_context_register_t)(unsigned long)code;
1475 *os_context_register_addr(context,reg_NARGS) = 0;
1476 *os_context_register_addr(context,reg_LIP) =
1477 (os_context_register_t)(unsigned long)code;
1478 *os_context_register_addr(context,reg_CFP) =
1479 (os_context_register_t)(unsigned long)current_control_frame_pointer;
1481 #ifdef ARCH_HAS_NPC_REGISTER
1482 *os_context_npc_addr(context) =
1483 4 + *os_context_pc_addr(context);
1485 #ifdef LISP_FEATURE_SPARC
1486 *os_context_register_addr(context,reg_CODE) =
1487 (os_context_register_t)(fun + FUN_POINTER_LOWTAG);
1489 FSHOW((stderr, "/arranged return to Lisp function (0x%lx)\n",
1493 /* KLUDGE: Theoretically the approach we use for undefined alien
1494 * variables should work for functions as well, but on PPC/Darwin
1495 * we get bus error at bogus addresses instead, hence this workaround,
1496 * that has the added benefit of automatically discriminating between
1497 * functions and variables.
1500 undefined_alien_function(void)
1502 funcall0(StaticSymbolFunction(UNDEFINED_ALIEN_FUNCTION_ERROR));
1505 void lower_thread_control_stack_guard_page(struct thread *th)
1507 protect_control_stack_guard_page(0, th);
1508 protect_control_stack_return_guard_page(1, th);
1509 th->control_stack_guard_page_protected = NIL;
1510 fprintf(stderr, "INFO: Control stack guard page unprotected\n");
1513 void reset_thread_control_stack_guard_page(struct thread *th)
1515 memset(CONTROL_STACK_GUARD_PAGE(th), 0, os_vm_page_size);
1516 protect_control_stack_guard_page(1, th);
1517 protect_control_stack_return_guard_page(0, th);
1518 th->control_stack_guard_page_protected = T;
1519 fprintf(stderr, "INFO: Control stack guard page reprotected\n");
1522 /* Called from the REPL, too. */
1523 void reset_control_stack_guard_page(void)
1525 struct thread *th=arch_os_get_current_thread();
1526 if (th->control_stack_guard_page_protected == NIL) {
1527 reset_thread_control_stack_guard_page(th);
1531 void lower_control_stack_guard_page(void)
1533 lower_thread_control_stack_guard_page(arch_os_get_current_thread());
1537 handle_guard_page_triggered(os_context_t *context,os_vm_address_t addr)
1539 struct thread *th=arch_os_get_current_thread();
1541 if(addr >= CONTROL_STACK_HARD_GUARD_PAGE(th) &&
1542 addr < CONTROL_STACK_HARD_GUARD_PAGE(th) + os_vm_page_size) {
1543 lose("Control stack exhausted");
1545 else if(addr >= CONTROL_STACK_GUARD_PAGE(th) &&
1546 addr < CONTROL_STACK_GUARD_PAGE(th) + os_vm_page_size) {
1547 /* We hit the end of the control stack: disable guard page
1548 * protection so the error handler has some headroom, protect the
1549 * previous page so that we can catch returns from the guard page
1550 * and restore it. */
1551 if (th->control_stack_guard_page_protected == NIL)
1552 lose("control_stack_guard_page_protected NIL");
1553 lower_control_stack_guard_page();
1554 #ifdef LISP_FEATURE_C_STACK_IS_CONTROL_STACK
1555 /* For the unfortunate case, when the control stack is
1556 * exhausted in a signal handler. */
1557 unblock_signals_in_context_and_maybe_warn(context);
1559 arrange_return_to_lisp_function
1560 (context, StaticSymbolFunction(CONTROL_STACK_EXHAUSTED_ERROR));
1563 else if(addr >= CONTROL_STACK_RETURN_GUARD_PAGE(th) &&
1564 addr < CONTROL_STACK_RETURN_GUARD_PAGE(th) + os_vm_page_size) {
1565 /* We're returning from the guard page: reprotect it, and
1566 * unprotect this one. This works even if we somehow missed
1567 * the return-guard-page, and hit it on our way to new
1568 * exhaustion instead. */
1569 if (th->control_stack_guard_page_protected != NIL)
1570 lose("control_stack_guard_page_protected not NIL");
1571 reset_control_stack_guard_page();
1574 else if(addr >= BINDING_STACK_HARD_GUARD_PAGE(th) &&
1575 addr < BINDING_STACK_HARD_GUARD_PAGE(th) + os_vm_page_size) {
1576 lose("Binding stack exhausted");
1578 else if(addr >= BINDING_STACK_GUARD_PAGE(th) &&
1579 addr < BINDING_STACK_GUARD_PAGE(th) + os_vm_page_size) {
1580 protect_binding_stack_guard_page(0, NULL);
1581 protect_binding_stack_return_guard_page(1, NULL);
1582 fprintf(stderr, "INFO: Binding stack guard page unprotected\n");
1584 /* For the unfortunate case, when the binding stack is
1585 * exhausted in a signal handler. */
1586 unblock_signals_in_context_and_maybe_warn(context);
1587 arrange_return_to_lisp_function
1588 (context, StaticSymbolFunction(BINDING_STACK_EXHAUSTED_ERROR));
1591 else if(addr >= BINDING_STACK_RETURN_GUARD_PAGE(th) &&
1592 addr < BINDING_STACK_RETURN_GUARD_PAGE(th) + os_vm_page_size) {
1593 protect_binding_stack_guard_page(1, NULL);
1594 protect_binding_stack_return_guard_page(0, NULL);
1595 fprintf(stderr, "INFO: Binding stack guard page reprotected\n");
1598 else if(addr >= ALIEN_STACK_HARD_GUARD_PAGE(th) &&
1599 addr < ALIEN_STACK_HARD_GUARD_PAGE(th) + os_vm_page_size) {
1600 lose("Alien stack exhausted");
1602 else if(addr >= ALIEN_STACK_GUARD_PAGE(th) &&
1603 addr < ALIEN_STACK_GUARD_PAGE(th) + os_vm_page_size) {
1604 protect_alien_stack_guard_page(0, NULL);
1605 protect_alien_stack_return_guard_page(1, NULL);
1606 fprintf(stderr, "INFO: Alien stack guard page unprotected\n");
1608 /* For the unfortunate case, when the alien stack is
1609 * exhausted in a signal handler. */
1610 unblock_signals_in_context_and_maybe_warn(context);
1611 arrange_return_to_lisp_function
1612 (context, StaticSymbolFunction(ALIEN_STACK_EXHAUSTED_ERROR));
1615 else if(addr >= ALIEN_STACK_RETURN_GUARD_PAGE(th) &&
1616 addr < ALIEN_STACK_RETURN_GUARD_PAGE(th) + os_vm_page_size) {
1617 protect_alien_stack_guard_page(1, NULL);
1618 protect_alien_stack_return_guard_page(0, NULL);
1619 fprintf(stderr, "INFO: Alien stack guard page reprotected\n");
1622 else if (addr >= undefined_alien_address &&
1623 addr < undefined_alien_address + os_vm_page_size) {
1624 arrange_return_to_lisp_function
1625 (context, StaticSymbolFunction(UNDEFINED_ALIEN_VARIABLE_ERROR));
1632 * noise to install handlers
1635 #ifndef LISP_FEATURE_WIN32
1636 /* In Linux 2.4 synchronous signals (sigtrap & co) can be delivered if
1637 * they are blocked, in Linux 2.6 the default handler is invoked
1638 * instead that usually coredumps. One might hastily think that adding
1639 * SA_NODEFER helps, but until ~2.6.13 if SA_NODEFER is specified then
1640 * the whole sa_mask is ignored and instead of not adding the signal
1641 * in question to the mask. That means if it's not blockable the
1642 * signal must be unblocked at the beginning of signal handlers.
1644 * It turns out that NetBSD's SA_NODEFER doesn't DTRT in a different
1645 * way: if SA_NODEFER is set and the signal is in sa_mask, the signal
1646 * will be unblocked in the sigmask during the signal handler. -- RMK
1649 static volatile int sigaction_nodefer_works = -1;
1651 #define SA_NODEFER_TEST_BLOCK_SIGNAL SIGABRT
1652 #define SA_NODEFER_TEST_KILL_SIGNAL SIGUSR1
1655 sigaction_nodefer_test_handler(int signal, siginfo_t *info, void *void_context)
1659 get_current_sigmask(¤t);
1660 /* There should be exactly two blocked signals: the two we added
1661 * to sa_mask when setting up the handler. NetBSD doesn't block
1662 * the signal we're handling when SA_NODEFER is set; Linux before
1663 * 2.6.13 or so also doesn't block the other signal when
1664 * SA_NODEFER is set. */
1665 for(i = 1; i < NSIG; i++)
1666 if (sigismember(¤t, i) !=
1667 (((i == SA_NODEFER_TEST_BLOCK_SIGNAL) || (i == signal)) ? 1 : 0)) {
1668 FSHOW_SIGNAL((stderr, "SA_NODEFER doesn't work, signal %d\n", i));
1669 sigaction_nodefer_works = 0;
1671 if (sigaction_nodefer_works == -1)
1672 sigaction_nodefer_works = 1;
1676 see_if_sigaction_nodefer_works(void)
1678 struct sigaction sa, old_sa;
1680 sa.sa_flags = SA_SIGINFO | SA_NODEFER;
1681 sa.sa_sigaction = sigaction_nodefer_test_handler;
1682 sigemptyset(&sa.sa_mask);
1683 sigaddset(&sa.sa_mask, SA_NODEFER_TEST_BLOCK_SIGNAL);
1684 sigaddset(&sa.sa_mask, SA_NODEFER_TEST_KILL_SIGNAL);
1685 sigaction(SA_NODEFER_TEST_KILL_SIGNAL, &sa, &old_sa);
1686 /* Make sure no signals are blocked. */
1689 sigemptyset(&empty);
1690 thread_sigmask(SIG_SETMASK, &empty, 0);
1692 kill(getpid(), SA_NODEFER_TEST_KILL_SIGNAL);
1693 while (sigaction_nodefer_works == -1);
1694 sigaction(SA_NODEFER_TEST_KILL_SIGNAL, &old_sa, NULL);
1697 #undef SA_NODEFER_TEST_BLOCK_SIGNAL
1698 #undef SA_NODEFER_TEST_KILL_SIGNAL
1701 unblock_me_trampoline(int signal, siginfo_t *info, void *void_context)
1703 SAVE_ERRNO(signal,context,void_context);
1706 sigemptyset(&unblock);
1707 sigaddset(&unblock, signal);
1708 thread_sigmask(SIG_UNBLOCK, &unblock, 0);
1709 interrupt_handle_now(signal, info, context);
1714 low_level_unblock_me_trampoline(int signal, siginfo_t *info, void *void_context)
1716 SAVE_ERRNO(signal,context,void_context);
1719 sigemptyset(&unblock);
1720 sigaddset(&unblock, signal);
1721 thread_sigmask(SIG_UNBLOCK, &unblock, 0);
1722 (*interrupt_low_level_handlers[signal])(signal, info, context);
1727 low_level_handle_now_handler(int signal, siginfo_t *info, void *void_context)
1729 SAVE_ERRNO(signal,context,void_context);
1730 (*interrupt_low_level_handlers[signal])(signal, info, context);
1735 undoably_install_low_level_interrupt_handler (int signal,
1736 interrupt_handler_t handler)
1738 struct sigaction sa;
1740 if (0 > signal || signal >= NSIG) {
1741 lose("bad signal number %d\n", signal);
1744 if (ARE_SAME_HANDLER(handler, SIG_DFL))
1745 sa.sa_sigaction = (void (*)(int, siginfo_t*, void*))handler;
1746 else if (sigismember(&deferrable_sigset,signal))
1747 sa.sa_sigaction = low_level_maybe_now_maybe_later;
1748 else if (!sigaction_nodefer_works &&
1749 !sigismember(&blockable_sigset, signal))
1750 sa.sa_sigaction = low_level_unblock_me_trampoline;
1752 sa.sa_sigaction = low_level_handle_now_handler;
1754 sigcopyset(&sa.sa_mask, &blockable_sigset);
1755 sa.sa_flags = SA_SIGINFO | SA_RESTART
1756 | (sigaction_nodefer_works ? SA_NODEFER : 0);
1757 #ifdef LISP_FEATURE_C_STACK_IS_CONTROL_STACK
1758 if((signal==SIG_MEMORY_FAULT))
1759 sa.sa_flags |= SA_ONSTACK;
1762 sigaction(signal, &sa, NULL);
1763 interrupt_low_level_handlers[signal] =
1764 (ARE_SAME_HANDLER(handler, SIG_DFL) ? 0 : handler);
1768 /* This is called from Lisp. */
1770 install_handler(int signal, void handler(int, siginfo_t*, os_context_t*))
1772 #ifndef LISP_FEATURE_WIN32
1773 struct sigaction sa;
1775 union interrupt_handler oldhandler;
1777 FSHOW((stderr, "/entering POSIX install_handler(%d, ..)\n", signal));
1779 block_blockable_signals(0, &old);
1781 FSHOW((stderr, "/interrupt_low_level_handlers[signal]=%x\n",
1782 (unsigned int)interrupt_low_level_handlers[signal]));
1783 if (interrupt_low_level_handlers[signal]==0) {
1784 if (ARE_SAME_HANDLER(handler, SIG_DFL) ||
1785 ARE_SAME_HANDLER(handler, SIG_IGN))
1786 sa.sa_sigaction = (void (*)(int, siginfo_t*, void*))handler;
1787 else if (sigismember(&deferrable_sigset, signal))
1788 sa.sa_sigaction = maybe_now_maybe_later;
1789 else if (!sigaction_nodefer_works &&
1790 !sigismember(&blockable_sigset, signal))
1791 sa.sa_sigaction = unblock_me_trampoline;
1793 sa.sa_sigaction = interrupt_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 sigaction(signal, &sa, NULL);
1801 oldhandler = interrupt_handlers[signal];
1802 interrupt_handlers[signal].c = handler;
1804 thread_sigmask(SIG_SETMASK, &old, 0);
1806 FSHOW((stderr, "/leaving POSIX install_handler(%d, ..)\n", signal));
1808 return (unsigned long)oldhandler.lisp;
1810 /* Probably-wrong Win32 hack */
1815 /* This must not go through lisp as it's allowed anytime, even when on
1818 sigabrt_handler(int signal, siginfo_t *info, os_context_t *context)
1820 lose("SIGABRT received.\n");
1824 interrupt_init(void)
1826 #ifndef LISP_FEATURE_WIN32
1828 SHOW("entering interrupt_init()");
1829 see_if_sigaction_nodefer_works();
1830 sigemptyset(&deferrable_sigset);
1831 sigemptyset(&blockable_sigset);
1832 sigemptyset(&gc_sigset);
1833 sigaddset_deferrable(&deferrable_sigset);
1834 sigaddset_blockable(&blockable_sigset);
1835 sigaddset_gc(&gc_sigset);
1837 /* Set up high level handler information. */
1838 for (i = 0; i < NSIG; i++) {
1839 interrupt_handlers[i].c =
1840 /* (The cast here blasts away the distinction between
1841 * SA_SIGACTION-style three-argument handlers and
1842 * signal(..)-style one-argument handlers, which is OK
1843 * because it works to call the 1-argument form where the
1844 * 3-argument form is expected.) */
1845 (void (*)(int, siginfo_t*, os_context_t*))SIG_DFL;
1847 undoably_install_low_level_interrupt_handler(SIGABRT, sigabrt_handler);
1848 SHOW("returning from interrupt_init()");
1852 #ifndef LISP_FEATURE_WIN32
1854 siginfo_code(siginfo_t *info)
1856 return info->si_code;
1858 os_vm_address_t current_memory_fault_address;
1861 lisp_memory_fault_error(os_context_t *context, os_vm_address_t addr)
1863 /* FIXME: This is lossy: if we get another memory fault (eg. from
1864 * another thread) before lisp has read this, we lose the information.
1865 * However, since this is mostly informative, we'll live with that for
1866 * now -- some address is better then no address in this case.
1868 current_memory_fault_address = addr;
1869 /* To allow debugging memory faults in signal handlers and such. */
1870 corruption_warning_and_maybe_lose("Memory fault at %x (pc=%p, sp=%p)",
1872 *os_context_pc_addr(context),
1873 #ifdef ARCH_HAS_STACK_POINTER
1874 *os_context_sp_addr(context)
1879 unblock_signals_in_context_and_maybe_warn(context);
1880 #ifdef LISP_FEATURE_C_STACK_IS_CONTROL_STACK
1881 arrange_return_to_lisp_function(context,
1882 StaticSymbolFunction(MEMORY_FAULT_ERROR));
1884 funcall0(StaticSymbolFunction(MEMORY_FAULT_ERROR));
1890 unhandled_trap_error(os_context_t *context)
1892 lispobj context_sap;
1893 fake_foreign_function_call(context);
1894 unblock_gc_signals(0, 0);
1895 context_sap = alloc_sap(context);
1896 #ifndef LISP_FEATURE_WIN32
1897 thread_sigmask(SIG_SETMASK, os_context_sigmask_addr(context), 0);
1899 funcall1(StaticSymbolFunction(UNHANDLED_TRAP_ERROR), context_sap);
1900 lose("UNHANDLED-TRAP-ERROR fell through");
1903 /* Common logic for trapping instructions. How we actually handle each
1904 * case is highly architecture dependent, but the overall shape is
1907 handle_trap(os_context_t *context, int trap)
1910 case trap_PendingInterrupt:
1911 FSHOW((stderr, "/<trap pending interrupt>\n"));
1912 arch_skip_instruction(context);
1913 interrupt_handle_pending(context);
1917 FSHOW((stderr, "/<trap error/cerror %d>\n", trap));
1918 interrupt_internal_error(context, trap==trap_Cerror);
1920 case trap_Breakpoint:
1921 arch_handle_breakpoint(context);
1923 case trap_FunEndBreakpoint:
1924 arch_handle_fun_end_breakpoint(context);
1926 #ifdef trap_AfterBreakpoint
1927 case trap_AfterBreakpoint:
1928 arch_handle_after_breakpoint(context);
1931 #ifdef trap_SingleStepAround
1932 case trap_SingleStepAround:
1933 case trap_SingleStepBefore:
1934 arch_handle_single_step_trap(context, trap);
1938 fake_foreign_function_call(context);
1939 lose("%%PRIMITIVE HALT called; the party is over.\n");
1941 unhandled_trap_error(context);