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>
56 #include "interrupt.h"
65 #include "genesis/fdefn.h"
66 #include "genesis/simple-fun.h"
67 #include "genesis/cons.h"
71 void run_deferred_handler(struct interrupt_data
*data
, void *v_context
) ;
72 static void store_signal_data_for_later (struct interrupt_data
*data
,
73 void *handler
, int signal
,
75 os_context_t
*context
);
76 boolean
interrupt_maybe_gc_int(int signal
, siginfo_t
*info
, void *v_context
);
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 thread_sigmask(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 thread_sigmask(SIG_SETMASK
,&new,0);
151 void block_blockable_signals ()
155 sigaddset_blockable(&block
);
156 thread_sigmask(SIG_BLOCK
, &block
, 0);
161 * utility routines used by various signal handlers
165 build_fake_control_stack_frames(struct thread
*th
,os_context_t
*context
)
167 #ifndef LISP_FEATURE_C_STACK_IS_CONTROL_STACK
171 /* Build a fake stack frame or frames */
173 current_control_frame_pointer
=
174 (lispobj
*)(*os_context_register_addr(context
, reg_CSP
));
175 if ((lispobj
*)(*os_context_register_addr(context
, reg_CFP
))
176 == current_control_frame_pointer
) {
177 /* There is a small window during call where the callee's
178 * frame isn't built yet. */
179 if (lowtag_of(*os_context_register_addr(context
, reg_CODE
))
180 == FUN_POINTER_LOWTAG
) {
181 /* We have called, but not built the new frame, so
182 * build it for them. */
183 current_control_frame_pointer
[0] =
184 *os_context_register_addr(context
, reg_OCFP
);
185 current_control_frame_pointer
[1] =
186 *os_context_register_addr(context
, reg_LRA
);
187 current_control_frame_pointer
+= 8;
188 /* Build our frame on top of it. */
189 oldcont
= (lispobj
)(*os_context_register_addr(context
, reg_CFP
));
192 /* We haven't yet called, build our frame as if the
193 * partial frame wasn't there. */
194 oldcont
= (lispobj
)(*os_context_register_addr(context
, reg_OCFP
));
197 /* We can't tell whether we are still in the caller if it had to
198 * allocate a stack frame due to stack arguments. */
199 /* This observation provoked some past CMUCL maintainer to ask
200 * "Can anything strange happen during return?" */
203 oldcont
= (lispobj
)(*os_context_register_addr(context
, reg_CFP
));
206 current_control_stack_pointer
= current_control_frame_pointer
+ 8;
208 current_control_frame_pointer
[0] = oldcont
;
209 current_control_frame_pointer
[1] = NIL
;
210 current_control_frame_pointer
[2] =
211 (lispobj
)(*os_context_register_addr(context
, reg_CODE
));
216 fake_foreign_function_call(os_context_t
*context
)
219 struct thread
*thread
=arch_os_get_current_thread();
221 /* context_index incrementing must not be interrupted */
222 check_blockables_blocked_or_lose();
224 /* Get current Lisp state from context. */
226 dynamic_space_free_pointer
=
227 (lispobj
*)(*os_context_register_addr(context
, reg_ALLOC
));
228 #if defined(LISP_FEATURE_ALPHA)
229 if ((long)dynamic_space_free_pointer
& 1) {
230 lose("dead in fake_foreign_function_call, context = %x", context
);
235 current_binding_stack_pointer
=
236 (lispobj
*)(*os_context_register_addr(context
, reg_BSP
));
239 build_fake_control_stack_frames(thread
,context
);
241 /* Do dynamic binding of the active interrupt context index
242 * and save the context in the context array. */
244 fixnum_value(SymbolValue(FREE_INTERRUPT_CONTEXT_INDEX
,thread
));
246 if (context_index
>= MAX_INTERRUPTS
) {
247 lose("maximum interrupt nesting depth (%d) exceeded", MAX_INTERRUPTS
);
250 bind_variable(FREE_INTERRUPT_CONTEXT_INDEX
,
251 make_fixnum(context_index
+ 1),thread
);
253 thread
->interrupt_contexts
[context_index
] = context
;
255 /* no longer in Lisp now */
256 foreign_function_call_active
= 1;
259 /* blocks all blockable signals. If you are calling from a signal handler,
260 * the usual signal mask will be restored from the context when the handler
261 * finishes. Otherwise, be careful */
264 undo_fake_foreign_function_call(os_context_t
*context
)
266 struct thread
*thread
=arch_os_get_current_thread();
267 /* Block all blockable signals. */
268 block_blockable_signals();
270 /* going back into Lisp */
271 foreign_function_call_active
= 0;
273 /* Undo dynamic binding of FREE_INTERRUPT_CONTEXT_INDEX */
277 /* Put the dynamic space free pointer back into the context. */
278 *os_context_register_addr(context
, reg_ALLOC
) =
279 (unsigned long) dynamic_space_free_pointer
;
283 /* a handler for the signal caused by execution of a trap opcode
284 * signalling an internal error */
286 interrupt_internal_error(int signal
, siginfo_t
*info
, os_context_t
*context
,
289 lispobj context_sap
= 0;
291 check_blockables_blocked_or_lose();
292 fake_foreign_function_call(context
);
294 /* Allocate the SAP object while the interrupts are still
296 if (internal_errors_enabled
) {
297 context_sap
= alloc_sap(context
);
300 thread_sigmask(SIG_SETMASK
, os_context_sigmask_addr(context
), 0);
302 if (internal_errors_enabled
) {
303 SHOW("in interrupt_internal_error");
305 /* Display some rudimentary debugging information about the
306 * error, so that even if the Lisp error handler gets badly
307 * confused, we have a chance to determine what's going on. */
308 describe_internal_error(context
);
310 funcall2(SymbolFunction(INTERNAL_ERROR
), context_sap
,
311 continuable
? T
: NIL
);
313 describe_internal_error(context
);
314 /* There's no good way to recover from an internal error
315 * before the Lisp error handling mechanism is set up. */
316 lose("internal error too early in init, can't recover");
318 undo_fake_foreign_function_call(context
); /* blocks signals again */
320 arch_skip_instruction(context
);
325 interrupt_handle_pending(os_context_t
*context
)
327 struct thread
*thread
;
328 struct interrupt_data
*data
;
330 check_blockables_blocked_or_lose();
331 check_interrupts_enabled_or_lose(context
);
333 thread
=arch_os_get_current_thread();
334 data
=thread
->interrupt_data
;
336 /* Pseudo atomic may trigger several times for a single interrupt,
337 * and while without-interrupts should not, a false trigger by
338 * pseudo-atomic may eat a pending handler even from
339 * without-interrupts. */
340 if (data
->pending_handler
) {
342 /* If we're here as the result of a pseudo-atomic as opposed
343 * to WITHOUT-INTERRUPTS, then INTERRUPT_PENDING is already
344 * NIL, because maybe_defer_handler sets
345 * PSEUDO_ATOMIC_INTERRUPTED only if interrupts are enabled.*/
346 SetSymbolValue(INTERRUPT_PENDING
, NIL
,thread
);
348 /* restore the saved signal mask from the original signal (the
349 * one that interrupted us during the critical section) into the
350 * os_context for the signal we're currently in the handler for.
351 * This should ensure that when we return from the handler the
352 * blocked signals are unblocked */
353 sigcopyset(os_context_sigmask_addr(context
), &data
->pending_mask
);
355 sigemptyset(&data
->pending_mask
);
356 /* This will break on sparc linux: the deferred handler really wants
357 * to be called with a void_context */
358 run_deferred_handler(data
,(void *)context
);
363 * the two main signal handlers:
364 * interrupt_handle_now(..)
365 * maybe_now_maybe_later(..)
367 * to which we have added interrupt_handle_now_handler(..). Why?
368 * Well, mostly because the SPARC/Linux platform doesn't quite do
369 * signals the way we want them done. The third argument in the
370 * handler isn't filled in by the kernel properly, so we fix it up
371 * ourselves in the arch_os_get_context(..) function; however, we only
372 * want to do this when we first hit the handler, and not when
373 * interrupt_handle_now(..) is being called from some other handler
374 * (when the fixup will already have been done). -- CSR, 2002-07-23
378 interrupt_handle_now(int signal
, siginfo_t
*info
, void *void_context
)
380 os_context_t
*context
= (os_context_t
*)void_context
;
381 struct thread
*thread
=arch_os_get_current_thread();
382 #if !defined(LISP_FEATURE_X86) && !defined(LISP_FEATURE_X86_64)
383 boolean were_in_lisp
;
385 union interrupt_handler handler
;
386 check_blockables_blocked_or_lose();
387 check_interrupts_enabled_or_lose(context
);
389 #ifdef LISP_FEATURE_LINUX
390 /* Under Linux on some architectures, we appear to have to restore
391 the FPU control word from the context, as after the signal is
392 delivered we appear to have a null FPU control word. */
393 os_restore_fp_control(context
);
395 handler
= thread
->interrupt_data
->interrupt_handlers
[signal
];
397 if (ARE_SAME_HANDLER(handler
.c
, SIG_IGN
)) {
401 #if !defined(LISP_FEATURE_X86) && !defined(LISP_FEATURE_X86_64)
402 were_in_lisp
= !foreign_function_call_active
;
406 fake_foreign_function_call(context
);
411 "/entering interrupt_handle_now(%d, info, context)\n",
415 if (ARE_SAME_HANDLER(handler
.c
, SIG_DFL
)) {
417 /* This can happen if someone tries to ignore or default one
418 * of the signals we need for runtime support, and the runtime
419 * support decides to pass on it. */
420 lose("no handler for signal %d in interrupt_handle_now(..)", signal
);
422 } else if (lowtag_of(handler
.lisp
) == FUN_POINTER_LOWTAG
) {
423 /* Once we've decided what to do about contexts in a
424 * return-elsewhere world (the original context will no longer
425 * be available; should we copy it or was nobody using it anyway?)
426 * then we should convert this to return-elsewhere */
428 /* CMUCL comment said "Allocate the SAPs while the interrupts
429 * are still disabled.". I (dan, 2003.08.21) assume this is
430 * because we're not in pseudoatomic and allocation shouldn't
431 * be interrupted. In which case it's no longer an issue as
432 * all our allocation from C now goes through a PA wrapper,
433 * but still, doesn't hurt */
435 lispobj info_sap
,context_sap
= alloc_sap(context
);
436 info_sap
= alloc_sap(info
);
437 /* Allow signals again. */
438 thread_sigmask(SIG_SETMASK
, os_context_sigmask_addr(context
), 0);
441 SHOW("calling Lisp-level handler");
444 funcall3(handler
.lisp
,
451 SHOW("calling C-level handler");
454 /* Allow signals again. */
455 thread_sigmask(SIG_SETMASK
, os_context_sigmask_addr(context
), 0);
457 (*handler
.c
)(signal
, info
, void_context
);
460 #if !defined(LISP_FEATURE_X86) && !defined(LISP_FEATURE_X86_64)
464 undo_fake_foreign_function_call(context
); /* block signals again */
469 "/returning from interrupt_handle_now(%d, info, context)\n",
474 /* This is called at the end of a critical section if the indications
475 * are that some signal was deferred during the section. Note that as
476 * far as C or the kernel is concerned we dealt with the signal
477 * already; we're just doing the Lisp-level processing now that we
481 run_deferred_handler(struct interrupt_data
*data
, void *v_context
) {
482 /* The pending_handler may enable interrupts (see
483 * interrupt_maybe_gc_int) and then another interrupt may hit,
484 * overwrite interrupt_data, so reset the pending handler before
485 * calling it. Trust the handler to finish with the siginfo before
486 * enabling interrupts. */
487 void (*pending_handler
) (int, siginfo_t
*, void*)=data
->pending_handler
;
488 data
->pending_handler
=0;
489 (*pending_handler
)(data
->pending_signal
,&(data
->pending_info
), v_context
);
493 maybe_defer_handler(void *handler
, struct interrupt_data
*data
,
494 int signal
, siginfo_t
*info
, os_context_t
*context
)
496 struct thread
*thread
=arch_os_get_current_thread();
498 check_blockables_blocked_or_lose();
500 if (SymbolValue(INTERRUPT_PENDING
,thread
) != NIL
)
501 lose("interrupt already pending");
502 /* If interrupts are disabled then INTERRUPT_PENDING is set and
503 * not PSEDUO_ATOMIC_INTERRUPTED. This is important for a pseudo
504 * atomic section inside a without-interrupts.
506 if (SymbolValue(INTERRUPTS_ENABLED
,thread
) == NIL
) {
507 store_signal_data_for_later(data
,handler
,signal
,info
,context
);
508 SetSymbolValue(INTERRUPT_PENDING
, T
,thread
);
511 "/maybe_defer_handler(%x,%d),thread=%ld: deferred\n",
512 (unsigned int)handler
,signal
,thread
->os_thread
));
516 /* a slightly confusing test. arch_pseudo_atomic_atomic() doesn't
517 * actually use its argument for anything on x86, so this branch
518 * may succeed even when context is null (gencgc alloc()) */
520 #if !defined(LISP_FEATURE_X86) && !defined(LISP_FEATURE_X86_64)
521 (!foreign_function_call_active
) &&
523 arch_pseudo_atomic_atomic(context
)) {
524 store_signal_data_for_later(data
,handler
,signal
,info
,context
);
525 arch_set_pseudo_atomic_interrupted(context
);
528 "/maybe_defer_handler(%x,%d),thread=%ld: deferred(PA)\n",
529 (unsigned int)handler
,signal
,thread
->os_thread
));
535 "/maybe_defer_handler(%x,%d),thread=%ld: not deferred\n",
536 (unsigned int)handler
,signal
,thread
->os_thread
));
542 store_signal_data_for_later (struct interrupt_data
*data
, void *handler
,
544 siginfo_t
*info
, os_context_t
*context
)
546 if (data
->pending_handler
)
547 lose("tried to overwrite pending interrupt handler %x with %x\n",
548 data
->pending_handler
, handler
);
550 lose("tried to defer null interrupt handler\n");
551 data
->pending_handler
= handler
;
552 data
->pending_signal
= signal
;
554 memcpy(&(data
->pending_info
), info
, sizeof(siginfo_t
));
556 /* the signal mask in the context (from before we were
557 * interrupted) is copied to be restored when
558 * run_deferred_handler happens. Then the usually-blocked
559 * signals are added to the mask in the context so that we are
560 * running with blocked signals when the handler returns */
561 sigcopyset(&(data
->pending_mask
),os_context_sigmask_addr(context
));
562 sigaddset_blockable(os_context_sigmask_addr(context
));
567 maybe_now_maybe_later(int signal
, siginfo_t
*info
, void *void_context
)
569 os_context_t
*context
= arch_os_get_context(&void_context
);
570 struct thread
*thread
=arch_os_get_current_thread();
571 struct interrupt_data
*data
=thread
->interrupt_data
;
572 #ifdef LISP_FEATURE_LINUX
573 os_restore_fp_control(context
);
575 if(maybe_defer_handler(interrupt_handle_now
,data
,
576 signal
,info
,context
))
578 interrupt_handle_now(signal
, info
, context
);
579 #ifdef LISP_FEATURE_DARWIN
580 /* Work around G5 bug */
581 DARWIN_FIX_CONTEXT(context
);
586 low_level_interrupt_handle_now(int signal
, siginfo_t
*info
, void *void_context
)
588 os_context_t
*context
= (os_context_t
*)void_context
;
589 struct thread
*thread
=arch_os_get_current_thread();
591 #ifdef LISP_FEATURE_LINUX
592 os_restore_fp_control(context
);
594 check_blockables_blocked_or_lose();
595 check_interrupts_enabled_or_lose(context
);
596 (*thread
->interrupt_data
->interrupt_low_level_handlers
[signal
])
597 (signal
, info
, void_context
);
598 #ifdef LISP_FEATURE_DARWIN
599 /* Work around G5 bug */
600 DARWIN_FIX_CONTEXT(context
);
605 low_level_maybe_now_maybe_later(int signal
, siginfo_t
*info
, void *void_context
)
607 os_context_t
*context
= arch_os_get_context(&void_context
);
608 struct thread
*thread
=arch_os_get_current_thread();
609 struct interrupt_data
*data
=thread
->interrupt_data
;
610 #ifdef LISP_FEATURE_LINUX
611 os_restore_fp_control(context
);
613 if(maybe_defer_handler(low_level_interrupt_handle_now
,data
,
614 signal
,info
,context
))
616 low_level_interrupt_handle_now(signal
, info
, context
);
617 #ifdef LISP_FEATURE_DARWIN
618 /* Work around G5 bug */
619 DARWIN_FIX_CONTEXT(context
);
623 #ifdef LISP_FEATURE_SB_THREAD
625 sig_stop_for_gc_handler(int signal
, siginfo_t
*info
, void *void_context
)
627 os_context_t
*context
= arch_os_get_context(&void_context
);
628 struct thread
*thread
=arch_os_get_current_thread();
632 /* need the context stored so it can have registers scavenged */
633 fake_foreign_function_call(context
);
636 for(i
=1;i
<NSIG
;i
++) sigaddset(&ss
,i
); /* Block everything. */
637 thread_sigmask(SIG_BLOCK
,&ss
,0);
639 /* The GC can't tell if a thread is a zombie, so this would be a
640 * good time to let the kernel reap any of our children in that
641 * awful state, to stop them from being waited for indefinitely.
642 * Userland reaping is done later when GC is finished */
643 if(thread
->state
!=STATE_RUNNING
) {
644 lose("sig_stop_for_gc_handler: wrong thread state: %ld\n",
645 fixnum_value(thread
->state
));
647 thread
->state
=STATE_SUSPENDED
;
649 sigemptyset(&ss
); sigaddset(&ss
,SIG_STOP_FOR_GC
);
651 if(thread
->state
!=STATE_SUSPENDED
) {
652 lose("sig_stop_for_gc_handler: wrong thread state on wakeup: %ld\n",
653 fixnum_value(thread
->state
));
655 thread
->state
=STATE_RUNNING
;
657 undo_fake_foreign_function_call(context
);
662 interrupt_handle_now_handler(int signal
, siginfo_t
*info
, void *void_context
)
664 os_context_t
*context
= arch_os_get_context(&void_context
);
665 interrupt_handle_now(signal
, info
, context
);
666 #ifdef LISP_FEATURE_DARWIN
667 DARWIN_FIX_CONTEXT(context
);
672 * stuff to detect and handle hitting the GC trigger
675 #ifndef LISP_FEATURE_GENCGC
676 /* since GENCGC has its own way to record trigger */
678 gc_trigger_hit(int signal
, siginfo_t
*info
, os_context_t
*context
)
680 if (current_auto_gc_trigger
== NULL
)
683 void *badaddr
=arch_get_bad_addr(signal
,info
,context
);
684 return (badaddr
>= (void *)current_auto_gc_trigger
&&
685 badaddr
<((void *)current_dynamic_space
+ DYNAMIC_SPACE_SIZE
));
690 /* manipulate the signal context and stack such that when the handler
691 * returns, it will call function instead of whatever it was doing
695 #if (defined(LISP_FEATURE_X86) || defined(LISP_FEATURE_X86_64))
696 int *context_eflags_addr(os_context_t
*context
);
699 extern lispobj
call_into_lisp(lispobj fun
, lispobj
*args
, int nargs
);
700 extern void post_signal_tramp(void);
701 void arrange_return_to_lisp_function(os_context_t
*context
, lispobj function
)
703 #if !(defined(LISP_FEATURE_X86) || defined(LISP_FEATURE_X86_64))
704 void * fun
=native_pointer(function
);
705 void *code
= &(((struct simple_fun
*) fun
)->code
);
708 /* Build a stack frame showing `interrupted' so that the
709 * user's backtrace makes (as much) sense (as usual) */
711 /* FIXME: what about restoring fp state? */
712 /* FIXME: what about restoring errno? */
713 #ifdef LISP_FEATURE_X86
714 /* Suppose the existence of some function that saved all
715 * registers, called call_into_lisp, then restored GP registers and
716 * returned. It would look something like this:
724 pushl {address of function to call}
725 call 0x8058db0 <call_into_lisp>
732 * What we do here is set up the stack that call_into_lisp would
733 * expect to see if it had been called by this code, and frob the
734 * signal context so that signal return goes directly to call_into_lisp,
735 * and when that function (and the lisp function it invoked) returns,
736 * it returns to the second half of this imaginary function which
737 * restores all registers and returns to C
739 * For this to work, the latter part of the imaginary function
740 * must obviously exist in reality. That would be post_signal_tramp
743 u32
*sp
=(u32
*)*os_context_register_addr(context
,reg_ESP
);
745 *(sp
-15) = post_signal_tramp
; /* return address for call_into_lisp */
746 *(sp
-14) = function
; /* args for call_into_lisp : function*/
747 *(sp
-13) = 0; /* arg array */
748 *(sp
-12) = 0; /* no. args */
749 /* this order matches that used in POPAD */
750 *(sp
-11)=*os_context_register_addr(context
,reg_EDI
);
751 *(sp
-10)=*os_context_register_addr(context
,reg_ESI
);
753 *(sp
-9)=*os_context_register_addr(context
,reg_ESP
)-8;
754 /* POPAD ignores the value of ESP: */
756 *(sp
-7)=*os_context_register_addr(context
,reg_EBX
);
758 *(sp
-6)=*os_context_register_addr(context
,reg_EDX
);
759 *(sp
-5)=*os_context_register_addr(context
,reg_ECX
);
760 *(sp
-4)=*os_context_register_addr(context
,reg_EAX
);
761 *(sp
-3)=*context_eflags_addr(context
);
762 *(sp
-2)=*os_context_register_addr(context
,reg_EBP
);
763 *(sp
-1)=*os_context_pc_addr(context
);
765 #elif defined(LISP_FEATURE_X86_64)
766 u64
*sp
=(u64
*)*os_context_register_addr(context
,reg_RSP
);
767 *(sp
-20) = post_signal_tramp
; /* return address for call_into_lisp */
769 *(sp
-19)=*os_context_register_addr(context
,reg_R15
);
770 *(sp
-18)=*os_context_register_addr(context
,reg_R14
);
771 *(sp
-17)=*os_context_register_addr(context
,reg_R13
);
772 *(sp
-16)=*os_context_register_addr(context
,reg_R12
);
773 *(sp
-15)=*os_context_register_addr(context
,reg_R11
);
774 *(sp
-14)=*os_context_register_addr(context
,reg_R10
);
775 *(sp
-13)=*os_context_register_addr(context
,reg_R9
);
776 *(sp
-12)=*os_context_register_addr(context
,reg_R8
);
777 *(sp
-11)=*os_context_register_addr(context
,reg_RDI
);
778 *(sp
-10)=*os_context_register_addr(context
,reg_RSI
);
779 *(sp
-9)=*os_context_register_addr(context
,reg_RSP
)-16;
781 *(sp
-7)=*os_context_register_addr(context
,reg_RBX
);
782 *(sp
-6)=*os_context_register_addr(context
,reg_RDX
);
783 *(sp
-5)=*os_context_register_addr(context
,reg_RCX
);
784 *(sp
-4)=*os_context_register_addr(context
,reg_RAX
);
785 *(sp
-3)=*context_eflags_addr(context
);
786 *(sp
-2)=*os_context_register_addr(context
,reg_RBP
);
787 *(sp
-1)=*os_context_pc_addr(context
);
789 *os_context_register_addr(context
,reg_RDI
) = function
; /* function */
790 *os_context_register_addr(context
,reg_RSI
) = 0; /* arg. array */
791 *os_context_register_addr(context
,reg_RDX
) = 0; /* no. args */
793 struct thread
*th
=arch_os_get_current_thread();
794 build_fake_control_stack_frames(th
,context
);
797 #ifdef LISP_FEATURE_X86
798 *os_context_pc_addr(context
) = call_into_lisp
;
799 *os_context_register_addr(context
,reg_ECX
) = 0;
800 *os_context_register_addr(context
,reg_EBP
) = sp
-2;
802 *os_context_register_addr(context
,reg_UESP
) = sp
-15;
804 *os_context_register_addr(context
,reg_ESP
) = sp
-15;
806 #elif defined(LISP_FEATURE_X86_64)
807 *os_context_pc_addr(context
) = call_into_lisp
;
808 *os_context_register_addr(context
,reg_RCX
) = 0;
809 *os_context_register_addr(context
,reg_RBP
) = sp
-2;
810 *os_context_register_addr(context
,reg_RSP
) = sp
-20;
812 /* this much of the calling convention is common to all
814 *os_context_pc_addr(context
) = code
;
815 *os_context_register_addr(context
,reg_NARGS
) = 0;
816 *os_context_register_addr(context
,reg_LIP
) = code
;
817 *os_context_register_addr(context
,reg_CFP
) =
818 current_control_frame_pointer
;
820 #ifdef ARCH_HAS_NPC_REGISTER
821 *os_context_npc_addr(context
) =
822 4 + *os_context_pc_addr(context
);
824 #ifdef LISP_FEATURE_SPARC
825 *os_context_register_addr(context
,reg_CODE
) =
826 fun
+ FUN_POINTER_LOWTAG
;
830 #ifdef LISP_FEATURE_SB_THREAD
831 void interrupt_thread_handler(int num
, siginfo_t
*info
, void *v_context
)
833 os_context_t
*context
= (os_context_t
*)arch_os_get_context(&v_context
);
834 /* The order of interrupt execution is peculiar. If thread A
835 * interrupts thread B with I1, I2 and B for some reason recieves
836 * I1 when FUN2 is already on the list, then it is FUN2 that gets
837 * to run first. But when FUN2 is run SIG_INTERRUPT_THREAD is
838 * enabled again and I2 hits pretty soon in FUN2 and run
839 * FUN1. This is of course just one scenario, and the order of
840 * thread interrupt execution is undefined. */
841 struct thread
*th
=arch_os_get_current_thread();
843 if (th
->state
!= STATE_RUNNING
)
844 lose("interrupt_thread_handler: thread %ld in wrong state: %d\n",
845 th
->os_thread
,fixnum_value(th
->state
));
846 get_spinlock(&th
->interrupt_fun_lock
,(long)th
);
847 c
=((struct cons
*)native_pointer(th
->interrupt_fun
));
848 arrange_return_to_lisp_function(context
,c
->car
);
849 th
->interrupt_fun
=(lispobj
*)(c
->cdr
);
850 release_spinlock(&th
->interrupt_fun_lock
);
855 /* KLUDGE: Theoretically the approach we use for undefined alien
856 * variables should work for functions as well, but on PPC/Darwin
857 * we get bus error at bogus addresses instead, hence this workaround,
858 * that has the added benefit of automatically discriminating between
859 * functions and variables.
861 void undefined_alien_function() {
862 funcall0(SymbolFunction(UNDEFINED_ALIEN_FUNCTION_ERROR
));
865 boolean
handle_guard_page_triggered(os_context_t
*context
,void *addr
){
866 struct thread
*th
=arch_os_get_current_thread();
868 /* note the os_context hackery here. When the signal handler returns,
869 * it won't go back to what it was doing ... */
870 if(addr
>= CONTROL_STACK_GUARD_PAGE(th
) &&
871 addr
< CONTROL_STACK_GUARD_PAGE(th
) + os_vm_page_size
) {
872 /* We hit the end of the control stack: disable guard page
873 * protection so the error handler has some headroom, protect the
874 * previous page so that we can catch returns from the guard page
876 protect_control_stack_guard_page(th
,0);
877 protect_control_stack_return_guard_page(th
,1);
879 arrange_return_to_lisp_function
880 (context
, SymbolFunction(CONTROL_STACK_EXHAUSTED_ERROR
));
883 else if(addr
>= CONTROL_STACK_RETURN_GUARD_PAGE(th
) &&
884 addr
< CONTROL_STACK_RETURN_GUARD_PAGE(th
) + os_vm_page_size
) {
885 /* We're returning from the guard page: reprotect it, and
886 * unprotect this one. This works even if we somehow missed
887 * the return-guard-page, and hit it on our way to new
888 * exhaustion instead. */
889 protect_control_stack_guard_page(th
,1);
890 protect_control_stack_return_guard_page(th
,0);
893 else if (addr
>= undefined_alien_address
&&
894 addr
< undefined_alien_address
+ os_vm_page_size
) {
895 arrange_return_to_lisp_function
896 (context
, SymbolFunction(UNDEFINED_ALIEN_VARIABLE_ERROR
));
902 #ifndef LISP_FEATURE_GENCGC
903 /* This function gets called from the SIGSEGV (for e.g. Linux, NetBSD, &
904 * OpenBSD) or SIGBUS (for e.g. FreeBSD) handler. Here we check
905 * whether the signal was due to treading on the mprotect()ed zone -
906 * and if so, arrange for a GC to happen. */
907 extern unsigned long bytes_consed_between_gcs
; /* gc-common.c */
910 interrupt_maybe_gc(int signal
, siginfo_t
*info
, void *void_context
)
912 os_context_t
*context
=(os_context_t
*) void_context
;
913 struct thread
*th
=arch_os_get_current_thread();
914 struct interrupt_data
*data
=
915 th
? th
->interrupt_data
: global_interrupt_data
;
917 if(!data
->pending_handler
&& !foreign_function_call_active
&&
918 gc_trigger_hit(signal
, info
, context
)){
919 clear_auto_gc_trigger();
920 if(!maybe_defer_handler(interrupt_maybe_gc_int
,
921 data
,signal
,info
,void_context
))
922 interrupt_maybe_gc_int(signal
,info
,void_context
);
930 /* this is also used by gencgc, in alloc() */
932 interrupt_maybe_gc_int(int signal
, siginfo_t
*info
, void *void_context
)
934 os_context_t
*context
=(os_context_t
*) void_context
;
936 check_blockables_blocked_or_lose();
937 fake_foreign_function_call(context
);
939 /* SUB-GC may return without GCing if *GC-INHIBIT* is set, in
940 * which case we will be running with no gc trigger barrier
941 * thing for a while. But it shouldn't be long until the end
944 * FIXME: It would be good to protect the end of dynamic space
945 * and signal a storage condition from there.
948 /* restore the signal mask from the interrupted context before
949 * calling into Lisp */
951 thread_sigmask(SIG_SETMASK
, os_context_sigmask_addr(context
), 0);
953 funcall0(SymbolFunction(SUB_GC
));
955 undo_fake_foreign_function_call(context
);
961 * noise to install handlers
965 undoably_install_low_level_interrupt_handler (int signal
,
971 struct thread
*th
=arch_os_get_current_thread();
972 struct interrupt_data
*data
=
973 th
? th
->interrupt_data
: global_interrupt_data
;
975 if (0 > signal
|| signal
>= NSIG
) {
976 lose("bad signal number %d", signal
);
979 if (sigismember(&blockable_sigset
,signal
))
980 sa
.sa_sigaction
= low_level_maybe_now_maybe_later
;
982 sa
.sa_sigaction
= handler
;
984 sigemptyset(&sa
.sa_mask
);
985 sigaddset_blockable(&sa
.sa_mask
);
986 sa
.sa_flags
= SA_SIGINFO
| SA_RESTART
;
987 #ifdef LISP_FEATURE_C_STACK_IS_CONTROL_STACK
988 if((signal
==SIG_MEMORY_FAULT
)
989 #ifdef SIG_INTERRUPT_THREAD
990 || (signal
==SIG_INTERRUPT_THREAD
)
993 sa
.sa_flags
|= SA_ONSTACK
;
996 sigaction(signal
, &sa
, NULL
);
997 data
->interrupt_low_level_handlers
[signal
] =
998 (ARE_SAME_HANDLER(handler
, SIG_DFL
) ? 0 : handler
);
1001 /* This is called from Lisp. */
1003 install_handler(int signal
, void handler(int, siginfo_t
*, void*))
1005 struct sigaction sa
;
1007 union interrupt_handler oldhandler
;
1008 struct thread
*th
=arch_os_get_current_thread();
1009 struct interrupt_data
*data
=
1010 th
? th
->interrupt_data
: global_interrupt_data
;
1012 FSHOW((stderr
, "/entering POSIX install_handler(%d, ..)\n", signal
));
1015 sigaddset(&new, signal
);
1016 thread_sigmask(SIG_BLOCK
, &new, &old
);
1019 sigaddset_blockable(&new);
1021 FSHOW((stderr
, "/data->interrupt_low_level_handlers[signal]=%x\n",
1022 (unsigned int)data
->interrupt_low_level_handlers
[signal
]));
1023 if (data
->interrupt_low_level_handlers
[signal
]==0) {
1024 if (ARE_SAME_HANDLER(handler
, SIG_DFL
) ||
1025 ARE_SAME_HANDLER(handler
, SIG_IGN
)) {
1026 sa
.sa_sigaction
= handler
;
1027 } else if (sigismember(&new, signal
)) {
1028 sa
.sa_sigaction
= maybe_now_maybe_later
;
1030 sa
.sa_sigaction
= interrupt_handle_now_handler
;
1033 sigemptyset(&sa
.sa_mask
);
1034 sigaddset_blockable(&sa
.sa_mask
);
1035 sa
.sa_flags
= SA_SIGINFO
| SA_RESTART
;
1036 sigaction(signal
, &sa
, NULL
);
1039 oldhandler
= data
->interrupt_handlers
[signal
];
1040 data
->interrupt_handlers
[signal
].c
= handler
;
1042 thread_sigmask(SIG_SETMASK
, &old
, 0);
1044 FSHOW((stderr
, "/leaving POSIX install_handler(%d, ..)\n", signal
));
1046 return (unsigned long)oldhandler
.lisp
;
1053 SHOW("entering interrupt_init()");
1054 sigemptyset(&blockable_sigset
);
1055 sigaddset_blockable(&blockable_sigset
);
1057 global_interrupt_data
=calloc(sizeof(struct interrupt_data
), 1);
1059 /* Set up high level handler information. */
1060 for (i
= 0; i
< NSIG
; i
++) {
1061 global_interrupt_data
->interrupt_handlers
[i
].c
=
1062 /* (The cast here blasts away the distinction between
1063 * SA_SIGACTION-style three-argument handlers and
1064 * signal(..)-style one-argument handlers, which is OK
1065 * because it works to call the 1-argument form where the
1066 * 3-argument form is expected.) */
1067 (void (*)(int, siginfo_t
*, void*))SIG_DFL
;
1070 SHOW("returning from interrupt_init()");