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 */
48 #include <sys/types.h>
55 #include "interrupt.h"
64 #include "genesis/fdefn.h"
65 #include "genesis/simple-fun.h"
69 void run_deferred_handler(struct interrupt_data *data, void *v_context) ;
70 static void store_signal_data_for_later (struct interrupt_data *data,
71 void *handler, int signal,
73 os_context_t *context);
74 boolean interrupt_maybe_gc_int(int signal, siginfo_t *info, void *v_context);
76 extern volatile lispobj all_threads_lock;
78 void sigaddset_blockable(sigset_t *s)
82 sigaddset(s, SIGQUIT);
83 sigaddset(s, SIGPIPE);
84 sigaddset(s, SIGALRM);
87 sigaddset(s, SIGTSTP);
88 sigaddset(s, SIGCHLD);
90 sigaddset(s, SIGXCPU);
91 sigaddset(s, SIGXFSZ);
92 sigaddset(s, SIGVTALRM);
93 sigaddset(s, SIGPROF);
94 sigaddset(s, SIGWINCH);
95 sigaddset(s, SIGUSR1);
96 sigaddset(s, SIGUSR2);
97 #ifdef LISP_FEATURE_SB_THREAD
98 sigaddset(s, SIG_STOP_FOR_GC);
99 sigaddset(s, SIG_INTERRUPT_THREAD);
103 static sigset_t blockable_sigset;
105 inline static void check_blockables_blocked_or_lose()
107 /* Get the current sigmask, by blocking the empty set. */
108 sigset_t empty,current;
111 sigprocmask(SIG_BLOCK, &empty, ¤t);
112 for(i=0;i<NSIG;i++) {
113 if (sigismember(&blockable_sigset, i) && !sigismember(¤t, i))
114 lose("blockable signal %d not blocked",i);
118 inline static void check_interrupts_enabled_or_lose(os_context_t *context)
120 struct thread *thread=arch_os_get_current_thread();
121 if (SymbolValue(INTERRUPTS_ENABLED,thread) == NIL)
122 lose("interrupts not enabled");
124 #if !defined(LISP_FEATURE_X86) && !defined(LISP_FEATURE_X86_64)
125 (!foreign_function_call_active) &&
127 arch_pseudo_atomic_atomic(context))
128 lose ("in pseudo atomic section");
131 /* When we catch an internal error, should we pass it back to Lisp to
132 * be handled in a high-level way? (Early in cold init, the answer is
133 * 'no', because Lisp is still too brain-dead to handle anything.
134 * After sufficient initialization has been completed, the answer
136 boolean internal_errors_enabled = 0;
138 struct interrupt_data * global_interrupt_data;
140 /* At the toplevel repl we routinely call this function. The signal
141 * mask ought to be clear anyway most of the time, but may be non-zero
142 * if we were interrupted e.g. while waiting for a queue. */
144 void reset_signal_mask ()
148 sigprocmask(SIG_SETMASK,&new,0);
155 * utility routines used by various signal handlers
159 build_fake_control_stack_frames(struct thread *th,os_context_t *context)
161 #ifndef LISP_FEATURE_C_STACK_IS_CONTROL_STACK
165 /* Build a fake stack frame or frames */
167 current_control_frame_pointer =
168 (lispobj *)(*os_context_register_addr(context, reg_CSP));
169 if ((lispobj *)(*os_context_register_addr(context, reg_CFP))
170 == current_control_frame_pointer) {
171 /* There is a small window during call where the callee's
172 * frame isn't built yet. */
173 if (lowtag_of(*os_context_register_addr(context, reg_CODE))
174 == FUN_POINTER_LOWTAG) {
175 /* We have called, but not built the new frame, so
176 * build it for them. */
177 current_control_frame_pointer[0] =
178 *os_context_register_addr(context, reg_OCFP);
179 current_control_frame_pointer[1] =
180 *os_context_register_addr(context, reg_LRA);
181 current_control_frame_pointer += 8;
182 /* Build our frame on top of it. */
183 oldcont = (lispobj)(*os_context_register_addr(context, reg_CFP));
186 /* We haven't yet called, build our frame as if the
187 * partial frame wasn't there. */
188 oldcont = (lispobj)(*os_context_register_addr(context, reg_OCFP));
191 /* We can't tell whether we are still in the caller if it had to
192 * allocate a stack frame due to stack arguments. */
193 /* This observation provoked some past CMUCL maintainer to ask
194 * "Can anything strange happen during return?" */
197 oldcont = (lispobj)(*os_context_register_addr(context, reg_CFP));
200 current_control_stack_pointer = current_control_frame_pointer + 8;
202 current_control_frame_pointer[0] = oldcont;
203 current_control_frame_pointer[1] = NIL;
204 current_control_frame_pointer[2] =
205 (lispobj)(*os_context_register_addr(context, reg_CODE));
210 fake_foreign_function_call(os_context_t *context)
213 struct thread *thread=arch_os_get_current_thread();
215 /* context_index incrementing must not be interrupted */
216 check_blockables_blocked_or_lose();
218 /* Get current Lisp state from context. */
220 dynamic_space_free_pointer =
221 (lispobj *)(*os_context_register_addr(context, reg_ALLOC));
222 #if defined(LISP_FEATURE_ALPHA)
223 if ((long)dynamic_space_free_pointer & 1) {
224 lose("dead in fake_foreign_function_call, context = %x", context);
229 current_binding_stack_pointer =
230 (lispobj *)(*os_context_register_addr(context, reg_BSP));
233 build_fake_control_stack_frames(thread,context);
235 /* Do dynamic binding of the active interrupt context index
236 * and save the context in the context array. */
238 fixnum_value(SymbolValue(FREE_INTERRUPT_CONTEXT_INDEX,thread));
240 if (context_index >= MAX_INTERRUPTS) {
241 lose("maximum interrupt nesting depth (%d) exceeded", MAX_INTERRUPTS);
244 bind_variable(FREE_INTERRUPT_CONTEXT_INDEX,
245 make_fixnum(context_index + 1),thread);
247 thread->interrupt_contexts[context_index] = context;
249 /* no longer in Lisp now */
250 foreign_function_call_active = 1;
253 /* blocks all blockable signals. If you are calling from a signal handler,
254 * the usual signal mask will be restored from the context when the handler
255 * finishes. Otherwise, be careful */
258 undo_fake_foreign_function_call(os_context_t *context)
260 struct thread *thread=arch_os_get_current_thread();
261 /* Block all blockable signals. */
264 sigaddset_blockable(&block);
265 sigprocmask(SIG_BLOCK, &block, 0);
267 /* going back into Lisp */
268 foreign_function_call_active = 0;
270 /* Undo dynamic binding of FREE_INTERRUPT_CONTEXT_INDEX */
274 /* Put the dynamic space free pointer back into the context. */
275 *os_context_register_addr(context, reg_ALLOC) =
276 (unsigned long) dynamic_space_free_pointer;
280 /* a handler for the signal caused by execution of a trap opcode
281 * signalling an internal error */
283 interrupt_internal_error(int signal, siginfo_t *info, os_context_t *context,
286 lispobj context_sap = 0;
288 check_blockables_blocked_or_lose();
289 fake_foreign_function_call(context);
291 /* Allocate the SAP object while the interrupts are still
293 if (internal_errors_enabled) {
294 context_sap = alloc_sap(context);
297 sigprocmask(SIG_SETMASK, os_context_sigmask_addr(context), 0);
299 if (internal_errors_enabled) {
300 SHOW("in interrupt_internal_error");
302 /* Display some rudimentary debugging information about the
303 * error, so that even if the Lisp error handler gets badly
304 * confused, we have a chance to determine what's going on. */
305 describe_internal_error(context);
307 funcall2(SymbolFunction(INTERNAL_ERROR), context_sap,
308 continuable ? T : NIL);
310 describe_internal_error(context);
311 /* There's no good way to recover from an internal error
312 * before the Lisp error handling mechanism is set up. */
313 lose("internal error too early in init, can't recover");
315 undo_fake_foreign_function_call(context); /* blocks signals again */
317 arch_skip_instruction(context);
322 interrupt_handle_pending(os_context_t *context)
324 struct thread *thread;
325 struct interrupt_data *data;
327 check_blockables_blocked_or_lose();
328 check_interrupts_enabled_or_lose(context);
330 thread=arch_os_get_current_thread();
331 data=thread->interrupt_data;
333 /* Pseudo atomic may trigger several times for a single interrupt,
334 * and while without-interrupts should not, a false trigger by
335 * pseudo-atomic may eat a pending handler even from
336 * without-interrupts. */
337 if (data->pending_handler) {
339 /* If we're here as the result of a pseudo-atomic as opposed
340 * to WITHOUT-INTERRUPTS, then INTERRUPT_PENDING is already
341 * NIL, because maybe_defer_handler sets
342 * PSEUDO_ATOMIC_INTERRUPTED only if interrupts are enabled.*/
343 SetSymbolValue(INTERRUPT_PENDING, NIL,thread);
345 /* restore the saved signal mask from the original signal (the
346 * one that interrupted us during the critical section) into the
347 * os_context for the signal we're currently in the handler for.
348 * This should ensure that when we return from the handler the
349 * blocked signals are unblocked */
350 sigcopyset(os_context_sigmask_addr(context), &data->pending_mask);
352 sigemptyset(&data->pending_mask);
353 /* This will break on sparc linux: the deferred handler really wants
354 * to be called with a void_context */
355 run_deferred_handler(data,(void *)context);
360 * the two main signal handlers:
361 * interrupt_handle_now(..)
362 * maybe_now_maybe_later(..)
364 * to which we have added interrupt_handle_now_handler(..). Why?
365 * Well, mostly because the SPARC/Linux platform doesn't quite do
366 * signals the way we want them done. The third argument in the
367 * handler isn't filled in by the kernel properly, so we fix it up
368 * ourselves in the arch_os_get_context(..) function; however, we only
369 * want to do this when we first hit the handler, and not when
370 * interrupt_handle_now(..) is being called from some other handler
371 * (when the fixup will already have been done). -- CSR, 2002-07-23
375 interrupt_handle_now(int signal, siginfo_t *info, void *void_context)
377 os_context_t *context = (os_context_t*)void_context;
378 struct thread *thread=arch_os_get_current_thread();
379 #if !defined(LISP_FEATURE_X86) && !defined(LISP_FEATURE_X86_64)
380 boolean were_in_lisp;
382 union interrupt_handler handler;
383 check_blockables_blocked_or_lose();
384 check_interrupts_enabled_or_lose(context);
386 #ifdef LISP_FEATURE_LINUX
387 /* Under Linux on some architectures, we appear to have to restore
388 the FPU control word from the context, as after the signal is
389 delivered we appear to have a null FPU control word. */
390 os_restore_fp_control(context);
392 handler = thread->interrupt_data->interrupt_handlers[signal];
394 if (ARE_SAME_HANDLER(handler.c, SIG_IGN)) {
398 #if !defined(LISP_FEATURE_X86) && !defined(LISP_FEATURE_X86_64)
399 were_in_lisp = !foreign_function_call_active;
403 fake_foreign_function_call(context);
408 "/entering interrupt_handle_now(%d, info, context)\n",
412 if (ARE_SAME_HANDLER(handler.c, SIG_DFL)) {
414 /* This can happen if someone tries to ignore or default one
415 * of the signals we need for runtime support, and the runtime
416 * support decides to pass on it. */
417 lose("no handler for signal %d in interrupt_handle_now(..)", signal);
419 } else if (lowtag_of(handler.lisp) == FUN_POINTER_LOWTAG) {
420 /* Once we've decided what to do about contexts in a
421 * return-elsewhere world (the original context will no longer
422 * be available; should we copy it or was nobody using it anyway?)
423 * then we should convert this to return-elsewhere */
425 /* CMUCL comment said "Allocate the SAPs while the interrupts
426 * are still disabled.". I (dan, 2003.08.21) assume this is
427 * because we're not in pseudoatomic and allocation shouldn't
428 * be interrupted. In which case it's no longer an issue as
429 * all our allocation from C now goes through a PA wrapper,
430 * but still, doesn't hurt */
432 lispobj info_sap,context_sap = alloc_sap(context);
433 info_sap = alloc_sap(info);
434 /* Allow signals again. */
435 sigprocmask(SIG_SETMASK, os_context_sigmask_addr(context), 0);
438 SHOW("calling Lisp-level handler");
441 funcall3(handler.lisp,
448 SHOW("calling C-level handler");
451 /* Allow signals again. */
452 sigprocmask(SIG_SETMASK, os_context_sigmask_addr(context), 0);
454 (*handler.c)(signal, info, void_context);
457 #if !defined(LISP_FEATURE_X86) && !defined(LISP_FEATURE_X86_64)
461 undo_fake_foreign_function_call(context); /* block signals again */
466 "/returning from interrupt_handle_now(%d, info, context)\n",
471 /* This is called at the end of a critical section if the indications
472 * are that some signal was deferred during the section. Note that as
473 * far as C or the kernel is concerned we dealt with the signal
474 * already; we're just doing the Lisp-level processing now that we
478 run_deferred_handler(struct interrupt_data *data, void *v_context) {
479 /* The pending_handler may enable interrupts (see
480 * interrupt_maybe_gc_int) and then another interrupt may hit,
481 * overwrite interrupt_data, so reset the pending handler before
482 * calling it. Trust the handler to finish with the siginfo before
483 * enabling interrupts. */
484 void (*pending_handler) (int, siginfo_t*, void*)=data->pending_handler;
485 data->pending_handler=0;
486 (*pending_handler)(data->pending_signal,&(data->pending_info), v_context);
490 maybe_defer_handler(void *handler, struct interrupt_data *data,
491 int signal, siginfo_t *info, os_context_t *context)
493 struct thread *thread=arch_os_get_current_thread();
495 check_blockables_blocked_or_lose();
497 if (SymbolValue(INTERRUPT_PENDING,thread) != NIL)
498 lose("interrupt already pending");
499 /* If interrupts are disabled then INTERRUPT_PENDING is set and
500 * not PSEDUO_ATOMIC_INTERRUPTED. This is important for a pseudo
501 * atomic section inside a without-interrupts.
503 if (SymbolValue(INTERRUPTS_ENABLED,thread) == NIL) {
504 store_signal_data_for_later(data,handler,signal,info,context);
505 SetSymbolValue(INTERRUPT_PENDING, T,thread);
508 "/maybe_defer_handler(%x,%d),thread=%d: deferred\n",
509 (unsigned int)handler,signal,thread->pid));
513 /* a slightly confusing test. arch_pseudo_atomic_atomic() doesn't
514 * actually use its argument for anything on x86, so this branch
515 * may succeed even when context is null (gencgc alloc()) */
517 #if !defined(LISP_FEATURE_X86) && !defined(LISP_FEATURE_X86_64)
518 (!foreign_function_call_active) &&
520 arch_pseudo_atomic_atomic(context)) {
521 store_signal_data_for_later(data,handler,signal,info,context);
522 arch_set_pseudo_atomic_interrupted(context);
525 "/maybe_defer_handler(%x,%d),thread=%d: deferred(PA)\n",
526 (unsigned int)handler,signal,thread->pid));
532 "/maybe_defer_handler(%x,%d),thread=%d: not deferred\n",
533 (unsigned int)handler,signal,thread->pid));
539 store_signal_data_for_later (struct interrupt_data *data, void *handler,
541 siginfo_t *info, os_context_t *context)
543 if (data->pending_handler)
544 lose("tried to overwrite pending interrupt handler %x with %x\n",
545 data->pending_handler, handler);
547 lose("tried to defer null interrupt handler\n");
548 data->pending_handler = handler;
549 data->pending_signal = signal;
551 memcpy(&(data->pending_info), info, sizeof(siginfo_t));
553 /* the signal mask in the context (from before we were
554 * interrupted) is copied to be restored when
555 * run_deferred_handler happens. Then the usually-blocked
556 * signals are added to the mask in the context so that we are
557 * running with blocked signals when the handler returns */
558 sigcopyset(&(data->pending_mask),os_context_sigmask_addr(context));
559 sigaddset_blockable(os_context_sigmask_addr(context));
564 maybe_now_maybe_later(int signal, siginfo_t *info, void *void_context)
566 os_context_t *context = arch_os_get_context(&void_context);
567 struct thread *thread=arch_os_get_current_thread();
568 struct interrupt_data *data=thread->interrupt_data;
569 #ifdef LISP_FEATURE_LINUX
570 os_restore_fp_control(context);
572 if(maybe_defer_handler(interrupt_handle_now,data,
573 signal,info,context))
575 interrupt_handle_now(signal, info, context);
576 #ifdef LISP_FEATURE_DARWIN
577 /* Work around G5 bug */
578 DARWIN_FIX_CONTEXT(context);
583 low_level_interrupt_handle_now(int signal, siginfo_t *info, void *void_context)
585 os_context_t *context = (os_context_t*)void_context;
586 struct thread *thread=arch_os_get_current_thread();
588 #ifdef LISP_FEATURE_LINUX
589 os_restore_fp_control(context);
591 check_blockables_blocked_or_lose();
592 check_interrupts_enabled_or_lose(context);
593 (*thread->interrupt_data->interrupt_low_level_handlers[signal])
594 (signal, info, void_context);
595 #ifdef LISP_FEATURE_DARWIN
596 /* Work around G5 bug */
597 DARWIN_FIX_CONTEXT(context);
602 low_level_maybe_now_maybe_later(int signal, siginfo_t *info, void *void_context)
604 os_context_t *context = arch_os_get_context(&void_context);
605 struct thread *thread=arch_os_get_current_thread();
606 struct interrupt_data *data=thread->interrupt_data;
607 #ifdef LISP_FEATURE_LINUX
608 os_restore_fp_control(context);
610 if(maybe_defer_handler(low_level_interrupt_handle_now,data,
611 signal,info,context))
613 low_level_interrupt_handle_now(signal, info, context);
614 #ifdef LISP_FEATURE_DARWIN
615 /* Work around G5 bug */
616 DARWIN_FIX_CONTEXT(context);
620 #ifdef LISP_FEATURE_SB_THREAD
622 sig_stop_for_gc_handler(int signal, siginfo_t *info, void *void_context)
624 os_context_t *context = arch_os_get_context(&void_context);
625 struct thread *thread=arch_os_get_current_thread();
629 /* need the context stored so it can have registers scavenged */
630 fake_foreign_function_call(context);
633 for(i=1;i<NSIG;i++) sigaddset(&ss,i); /* Block everything. */
634 sigprocmask(SIG_BLOCK,&ss,0);
636 /* The GC can't tell if a thread is a zombie, so this would be a
637 * good time to let the kernel reap any of our children in that
638 * awful state, to stop them from being waited for indefinitely.
639 * Userland reaping is done later when GC is finished */
641 if(thread->state!=STATE_STOPPING) {
642 lose("sig_stop_for_gc_handler: wrong thread state: %ld\n",
643 fixnum_value(thread->state));
645 thread->state=STATE_STOPPED;
647 sigemptyset(&ss); sigaddset(&ss,SIG_STOP_FOR_GC);
649 if(thread->state!=STATE_STOPPED) {
650 lose("sig_stop_for_gc_handler: wrong thread state on wakeup: %ld\n",
651 fixnum_value(thread->state));
653 thread->state=STATE_RUNNING;
655 undo_fake_foreign_function_call(context);
660 interrupt_handle_now_handler(int signal, siginfo_t *info, void *void_context)
662 os_context_t *context = arch_os_get_context(&void_context);
663 interrupt_handle_now(signal, info, context);
664 #ifdef LISP_FEATURE_DARWIN
665 DARWIN_FIX_CONTEXT(context);
670 * stuff to detect and handle hitting the GC trigger
673 #ifndef LISP_FEATURE_GENCGC
674 /* since GENCGC has its own way to record trigger */
676 gc_trigger_hit(int signal, siginfo_t *info, os_context_t *context)
678 if (current_auto_gc_trigger == NULL)
681 void *badaddr=arch_get_bad_addr(signal,info,context);
682 return (badaddr >= (void *)current_auto_gc_trigger &&
683 badaddr <((void *)current_dynamic_space + DYNAMIC_SPACE_SIZE));
688 /* manipulate the signal context and stack such that when the handler
689 * returns, it will call function instead of whatever it was doing
693 #if (defined(LISP_FEATURE_X86) || defined(LISP_FEATURE_X86_64))
694 int *context_eflags_addr(os_context_t *context);
697 extern lispobj call_into_lisp(lispobj fun, lispobj *args, int nargs);
698 extern void post_signal_tramp(void);
699 void arrange_return_to_lisp_function(os_context_t *context, lispobj function)
701 #if !(defined(LISP_FEATURE_X86) || defined(LISP_FEATURE_X86_64))
702 void * fun=native_pointer(function);
703 void *code = &(((struct simple_fun *) fun)->code);
706 /* Build a stack frame showing `interrupted' so that the
707 * user's backtrace makes (as much) sense (as usual) */
709 /* FIXME: what about restoring fp state? */
710 #ifdef LISP_FEATURE_X86
711 /* Suppose the existence of some function that saved all
712 * registers, called call_into_lisp, then restored GP registers and
713 * returned. It would look something like this:
720 pushl {address of function to call}
721 call 0x8058db0 <call_into_lisp>
727 * What we do here is set up the stack that call_into_lisp would
728 * expect to see if it had been called by this code, and frob the
729 * signal context so that signal return goes directly to call_into_lisp,
730 * and when that function (and the lisp function it invoked) returns,
731 * it returns to the second half of this imaginary function which
732 * restores all registers and returns to C
734 * For this to work, the latter part of the imaginary function
735 * must obviously exist in reality. That would be post_signal_tramp
738 u32 *sp=(u32 *)*os_context_register_addr(context,reg_ESP);
740 *(sp-15) = post_signal_tramp; /* return address for call_into_lisp */
741 *(sp-14) = function; /* args for call_into_lisp : function*/
742 *(sp-13) = 0; /* arg array */
743 *(sp-12) = 0; /* no. args */
744 /* this order matches that used in POPAD */
745 *(sp-11)=*os_context_register_addr(context,reg_EDI);
746 *(sp-10)=*os_context_register_addr(context,reg_ESI);
748 *(sp-9)=*os_context_register_addr(context,reg_ESP)-8;
749 /* POPAD ignores the value of ESP: */
751 *(sp-7)=*os_context_register_addr(context,reg_EBX);
753 *(sp-6)=*os_context_register_addr(context,reg_EDX);
754 *(sp-5)=*os_context_register_addr(context,reg_ECX);
755 *(sp-4)=*os_context_register_addr(context,reg_EAX);
756 *(sp-3)=*context_eflags_addr(context);
757 *(sp-2)=*os_context_register_addr(context,reg_EBP);
758 *(sp-1)=*os_context_pc_addr(context);
760 #elif defined(LISP_FEATURE_X86_64)
761 u64 *sp=(u64 *)*os_context_register_addr(context,reg_RSP);
762 *(sp-20) = post_signal_tramp; /* return address for call_into_lisp */
764 *(sp-19)=*os_context_register_addr(context,reg_R15);
765 *(sp-18)=*os_context_register_addr(context,reg_R14);
766 *(sp-17)=*os_context_register_addr(context,reg_R13);
767 *(sp-16)=*os_context_register_addr(context,reg_R12);
768 *(sp-15)=*os_context_register_addr(context,reg_R11);
769 *(sp-14)=*os_context_register_addr(context,reg_R10);
770 *(sp-13)=*os_context_register_addr(context,reg_R9);
771 *(sp-12)=*os_context_register_addr(context,reg_R8);
772 *(sp-11)=*os_context_register_addr(context,reg_RDI);
773 *(sp-10)=*os_context_register_addr(context,reg_RSI);
774 *(sp-9)=*os_context_register_addr(context,reg_RSP)-16;
776 *(sp-7)=*os_context_register_addr(context,reg_RBX);
777 *(sp-6)=*os_context_register_addr(context,reg_RDX);
778 *(sp-5)=*os_context_register_addr(context,reg_RCX);
779 *(sp-4)=*os_context_register_addr(context,reg_RAX);
780 *(sp-3)=*context_eflags_addr(context);
781 *(sp-2)=*os_context_register_addr(context,reg_RBP);
782 *(sp-1)=*os_context_pc_addr(context);
784 *os_context_register_addr(context,reg_RDI) = function; /* function */
785 *os_context_register_addr(context,reg_RSI) = 0; /* arg. array */
786 *os_context_register_addr(context,reg_RDX) = 0; /* no. args */
788 struct thread *th=arch_os_get_current_thread();
789 build_fake_control_stack_frames(th,context);
792 #ifdef LISP_FEATURE_X86
793 *os_context_pc_addr(context) = call_into_lisp;
794 *os_context_register_addr(context,reg_ECX) = 0;
795 *os_context_register_addr(context,reg_EBP) = sp-2;
797 *os_context_register_addr(context,reg_UESP) = sp-15;
799 *os_context_register_addr(context,reg_ESP) = sp-15;
801 #elif defined(LISP_FEATURE_X86_64)
802 *os_context_pc_addr(context) = call_into_lisp;
803 *os_context_register_addr(context,reg_RCX) = 0;
804 *os_context_register_addr(context,reg_RBP) = sp-2;
805 *os_context_register_addr(context,reg_RSP) = sp-20;
807 /* this much of the calling convention is common to all
809 *os_context_pc_addr(context) = code;
810 *os_context_register_addr(context,reg_NARGS) = 0;
811 *os_context_register_addr(context,reg_LIP) = code;
812 *os_context_register_addr(context,reg_CFP) =
813 current_control_frame_pointer;
815 #ifdef ARCH_HAS_NPC_REGISTER
816 *os_context_npc_addr(context) =
817 4 + *os_context_pc_addr(context);
819 #ifdef LISP_FEATURE_SPARC
820 *os_context_register_addr(context,reg_CODE) =
821 fun + FUN_POINTER_LOWTAG;
825 #ifdef LISP_FEATURE_SB_THREAD
826 void interrupt_thread_handler(int num, siginfo_t *info, void *v_context)
828 os_context_t *context = (os_context_t*)arch_os_get_context(&v_context);
829 arrange_return_to_lisp_function(context,info->si_value.sival_int);
832 void thread_exit_handler(int num, siginfo_t *info, void *v_context)
833 { /* called when a child thread exits */
839 /* KLUDGE: Theoretically the approach we use for undefined alien
840 * variables should work for functions as well, but on PPC/Darwin
841 * we get bus error at bogus addresses instead, hence this workaround,
842 * that has the added benefit of automatically discriminating between
843 * functions and variables.
845 void undefined_alien_function() {
846 funcall0(SymbolFunction(UNDEFINED_ALIEN_FUNCTION_ERROR));
849 boolean handle_guard_page_triggered(os_context_t *context,void *addr){
850 struct thread *th=arch_os_get_current_thread();
852 /* note the os_context hackery here. When the signal handler returns,
853 * it won't go back to what it was doing ... */
854 if(addr >= CONTROL_STACK_GUARD_PAGE(th) &&
855 addr < CONTROL_STACK_GUARD_PAGE(th) + os_vm_page_size) {
856 /* We hit the end of the control stack: disable guard page
857 * protection so the error handler has some headroom, protect the
858 * previous page so that we can catch returns from the guard page
860 protect_control_stack_guard_page(th->pid,0);
861 protect_control_stack_return_guard_page(th->pid,1);
863 arrange_return_to_lisp_function
864 (context, SymbolFunction(CONTROL_STACK_EXHAUSTED_ERROR));
867 else if(addr >= CONTROL_STACK_RETURN_GUARD_PAGE(th) &&
868 addr < CONTROL_STACK_RETURN_GUARD_PAGE(th) + os_vm_page_size) {
869 /* We're returning from the guard page: reprotect it, and
870 * unprotect this one. This works even if we somehow missed
871 * the return-guard-page, and hit it on our way to new
872 * exhaustion instead. */
873 protect_control_stack_guard_page(th->pid,1);
874 protect_control_stack_return_guard_page(th->pid,0);
877 else if (addr >= undefined_alien_address &&
878 addr < undefined_alien_address + os_vm_page_size) {
879 arrange_return_to_lisp_function
880 (context, SymbolFunction(UNDEFINED_ALIEN_VARIABLE_ERROR));
886 #ifndef LISP_FEATURE_GENCGC
887 /* This function gets called from the SIGSEGV (for e.g. Linux, NetBSD, &
888 * OpenBSD) or SIGBUS (for e.g. FreeBSD) handler. Here we check
889 * whether the signal was due to treading on the mprotect()ed zone -
890 * and if so, arrange for a GC to happen. */
891 extern unsigned long bytes_consed_between_gcs; /* gc-common.c */
894 interrupt_maybe_gc(int signal, siginfo_t *info, void *void_context)
896 os_context_t *context=(os_context_t *) void_context;
897 struct thread *th=arch_os_get_current_thread();
898 struct interrupt_data *data=
899 th ? th->interrupt_data : global_interrupt_data;
901 if(!data->pending_handler && !foreign_function_call_active &&
902 gc_trigger_hit(signal, info, context)){
903 clear_auto_gc_trigger();
904 if(!maybe_defer_handler(interrupt_maybe_gc_int,
905 data,signal,info,void_context))
906 interrupt_maybe_gc_int(signal,info,void_context);
914 /* this is also used by gencgc, in alloc() */
916 interrupt_maybe_gc_int(int signal, siginfo_t *info, void *void_context)
918 os_context_t *context=(os_context_t *) void_context;
920 check_blockables_blocked_or_lose();
921 fake_foreign_function_call(context);
923 /* SUB-GC may return without GCing if *GC-INHIBIT* is set, in
924 * which case we will be running with no gc trigger barrier
925 * thing for a while. But it shouldn't be long until the end
928 * FIXME: It would be good to protect the end of dynamic space
929 * and signal a storage condition from there.
932 /* restore the signal mask from the interrupted context before
933 * calling into Lisp */
935 sigprocmask(SIG_SETMASK, os_context_sigmask_addr(context), 0);
937 funcall0(SymbolFunction(SUB_GC));
939 undo_fake_foreign_function_call(context);
945 * noise to install handlers
949 undoably_install_low_level_interrupt_handler (int signal,
955 struct thread *th=arch_os_get_current_thread();
956 struct interrupt_data *data=
957 th ? th->interrupt_data : global_interrupt_data;
959 if (0 > signal || signal >= NSIG) {
960 lose("bad signal number %d", signal);
963 if (sigismember(&blockable_sigset,signal))
964 sa.sa_sigaction = low_level_maybe_now_maybe_later;
966 sa.sa_sigaction = handler;
968 sigemptyset(&sa.sa_mask);
969 sigaddset_blockable(&sa.sa_mask);
970 sa.sa_flags = SA_SIGINFO | SA_RESTART;
971 #ifdef LISP_FEATURE_C_STACK_IS_CONTROL_STACK
972 if((signal==SIG_MEMORY_FAULT)
973 #ifdef SIG_INTERRUPT_THREAD
974 || (signal==SIG_INTERRUPT_THREAD)
977 sa.sa_flags|= SA_ONSTACK;
980 sigaction(signal, &sa, NULL);
981 data->interrupt_low_level_handlers[signal] =
982 (ARE_SAME_HANDLER(handler, SIG_DFL) ? 0 : handler);
985 /* This is called from Lisp. */
987 install_handler(int signal, void handler(int, siginfo_t*, void*))
991 union interrupt_handler oldhandler;
992 struct thread *th=arch_os_get_current_thread();
993 struct interrupt_data *data=
994 th ? th->interrupt_data : global_interrupt_data;
996 FSHOW((stderr, "/entering POSIX install_handler(%d, ..)\n", signal));
999 sigaddset(&new, signal);
1000 sigprocmask(SIG_BLOCK, &new, &old);
1003 sigaddset_blockable(&new);
1005 FSHOW((stderr, "/data->interrupt_low_level_handlers[signal]=%x\n",
1006 (unsigned int)data->interrupt_low_level_handlers[signal]));
1007 if (data->interrupt_low_level_handlers[signal]==0) {
1008 if (ARE_SAME_HANDLER(handler, SIG_DFL) ||
1009 ARE_SAME_HANDLER(handler, SIG_IGN)) {
1010 sa.sa_sigaction = handler;
1011 } else if (sigismember(&new, signal)) {
1012 sa.sa_sigaction = maybe_now_maybe_later;
1014 sa.sa_sigaction = interrupt_handle_now_handler;
1017 sigemptyset(&sa.sa_mask);
1018 sigaddset_blockable(&sa.sa_mask);
1019 sa.sa_flags = SA_SIGINFO | SA_RESTART;
1020 sigaction(signal, &sa, NULL);
1023 oldhandler = data->interrupt_handlers[signal];
1024 data->interrupt_handlers[signal].c = handler;
1026 sigprocmask(SIG_SETMASK, &old, 0);
1028 FSHOW((stderr, "/leaving POSIX install_handler(%d, ..)\n", signal));
1030 return (unsigned long)oldhandler.lisp;
1037 SHOW("entering interrupt_init()");
1038 sigemptyset(&blockable_sigset);
1039 sigaddset_blockable(&blockable_sigset);
1041 global_interrupt_data=calloc(sizeof(struct interrupt_data), 1);
1043 /* Set up high level handler information. */
1044 for (i = 0; i < NSIG; i++) {
1045 global_interrupt_data->interrupt_handlers[i].c =
1046 /* (The cast here blasts away the distinction between
1047 * SA_SIGACTION-style three-argument handlers and
1048 * signal(..)-style one-argument handlers, which is OK
1049 * because it works to call the 1-argument form where the
1050 * 3-argument form is expected.) */
1051 (void (*)(int, siginfo_t*, void*))SIG_DFL;
1054 SHOW("returning from interrupt_init()");