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>
57 #include "interrupt.h"
66 #include "genesis/fdefn.h"
67 #include "genesis/simple-fun.h"
68 #include "genesis/cons.h"
72 void run_deferred_handler(struct interrupt_data
*data
, void *v_context
) ;
73 static void store_signal_data_for_later (struct interrupt_data
*data
,
74 void *handler
, int signal
,
76 os_context_t
*context
);
77 boolean
interrupt_maybe_gc_int(int signal
, siginfo_t
*info
, void *v_context
);
79 void sigaddset_blockable(sigset_t
*s
)
83 sigaddset(s
, SIGQUIT
);
84 sigaddset(s
, SIGPIPE
);
85 sigaddset(s
, SIGALRM
);
88 sigaddset(s
, SIGTSTP
);
89 sigaddset(s
, SIGCHLD
);
91 sigaddset(s
, SIGXCPU
);
92 sigaddset(s
, SIGXFSZ
);
93 sigaddset(s
, SIGVTALRM
);
94 sigaddset(s
, SIGPROF
);
95 sigaddset(s
, SIGWINCH
);
96 sigaddset(s
, SIGUSR1
);
97 sigaddset(s
, SIGUSR2
);
98 #ifdef LISP_FEATURE_SB_THREAD
99 sigaddset(s
, SIG_STOP_FOR_GC
);
100 sigaddset(s
, SIG_INTERRUPT_THREAD
);
104 static sigset_t blockable_sigset
;
106 inline static void check_blockables_blocked_or_lose()
108 /* Get the current sigmask, by blocking the empty set. */
109 sigset_t empty
,current
;
112 thread_sigmask(SIG_BLOCK
, &empty
, ¤t
);
113 for(i
=0;i
<NSIG
;i
++) {
114 if (sigismember(&blockable_sigset
, i
) && !sigismember(¤t
, i
))
115 lose("blockable signal %d not blocked",i
);
119 inline static void check_interrupts_enabled_or_lose(os_context_t
*context
)
121 struct thread
*thread
=arch_os_get_current_thread();
122 if (SymbolValue(INTERRUPTS_ENABLED
,thread
) == NIL
)
123 lose("interrupts not enabled");
125 #if !defined(LISP_FEATURE_X86) && !defined(LISP_FEATURE_X86_64)
126 (!foreign_function_call_active
) &&
128 arch_pseudo_atomic_atomic(context
))
129 lose ("in pseudo atomic section");
132 /* When we catch an internal error, should we pass it back to Lisp to
133 * be handled in a high-level way? (Early in cold init, the answer is
134 * 'no', because Lisp is still too brain-dead to handle anything.
135 * After sufficient initialization has been completed, the answer
137 boolean internal_errors_enabled
= 0;
139 struct interrupt_data
* global_interrupt_data
;
141 /* At the toplevel repl we routinely call this function. The signal
142 * mask ought to be clear anyway most of the time, but may be non-zero
143 * if we were interrupted e.g. while waiting for a queue. */
145 void reset_signal_mask ()
149 thread_sigmask(SIG_SETMASK
,&new,0);
152 void block_blockable_signals ()
156 sigaddset_blockable(&block
);
157 thread_sigmask(SIG_BLOCK
, &block
, 0);
162 * utility routines used by various signal handlers
166 build_fake_control_stack_frames(struct thread
*th
,os_context_t
*context
)
168 #ifndef LISP_FEATURE_C_STACK_IS_CONTROL_STACK
172 /* Build a fake stack frame or frames */
174 current_control_frame_pointer
=
175 (lispobj
*)(*os_context_register_addr(context
, reg_CSP
));
176 if ((lispobj
*)(*os_context_register_addr(context
, reg_CFP
))
177 == current_control_frame_pointer
) {
178 /* There is a small window during call where the callee's
179 * frame isn't built yet. */
180 if (lowtag_of(*os_context_register_addr(context
, reg_CODE
))
181 == FUN_POINTER_LOWTAG
) {
182 /* We have called, but not built the new frame, so
183 * build it for them. */
184 current_control_frame_pointer
[0] =
185 *os_context_register_addr(context
, reg_OCFP
);
186 current_control_frame_pointer
[1] =
187 *os_context_register_addr(context
, reg_LRA
);
188 current_control_frame_pointer
+= 8;
189 /* Build our frame on top of it. */
190 oldcont
= (lispobj
)(*os_context_register_addr(context
, reg_CFP
));
193 /* We haven't yet called, build our frame as if the
194 * partial frame wasn't there. */
195 oldcont
= (lispobj
)(*os_context_register_addr(context
, reg_OCFP
));
198 /* We can't tell whether we are still in the caller if it had to
199 * allocate a stack frame due to stack arguments. */
200 /* This observation provoked some past CMUCL maintainer to ask
201 * "Can anything strange happen during return?" */
204 oldcont
= (lispobj
)(*os_context_register_addr(context
, reg_CFP
));
207 current_control_stack_pointer
= current_control_frame_pointer
+ 8;
209 current_control_frame_pointer
[0] = oldcont
;
210 current_control_frame_pointer
[1] = NIL
;
211 current_control_frame_pointer
[2] =
212 (lispobj
)(*os_context_register_addr(context
, reg_CODE
));
217 fake_foreign_function_call(os_context_t
*context
)
220 struct thread
*thread
=arch_os_get_current_thread();
222 /* context_index incrementing must not be interrupted */
223 check_blockables_blocked_or_lose();
225 /* Get current Lisp state from context. */
227 dynamic_space_free_pointer
=
228 (lispobj
*)(*os_context_register_addr(context
, reg_ALLOC
));
229 #if defined(LISP_FEATURE_ALPHA)
230 if ((long)dynamic_space_free_pointer
& 1) {
231 lose("dead in fake_foreign_function_call, context = %x", context
);
236 current_binding_stack_pointer
=
237 (lispobj
*)(*os_context_register_addr(context
, reg_BSP
));
240 build_fake_control_stack_frames(thread
,context
);
242 /* Do dynamic binding of the active interrupt context index
243 * and save the context in the context array. */
245 fixnum_value(SymbolValue(FREE_INTERRUPT_CONTEXT_INDEX
,thread
));
247 if (context_index
>= MAX_INTERRUPTS
) {
248 lose("maximum interrupt nesting depth (%d) exceeded", MAX_INTERRUPTS
);
251 bind_variable(FREE_INTERRUPT_CONTEXT_INDEX
,
252 make_fixnum(context_index
+ 1),thread
);
254 thread
->interrupt_contexts
[context_index
] = context
;
256 /* no longer in Lisp now */
257 foreign_function_call_active
= 1;
260 /* blocks all blockable signals. If you are calling from a signal handler,
261 * the usual signal mask will be restored from the context when the handler
262 * finishes. Otherwise, be careful */
265 undo_fake_foreign_function_call(os_context_t
*context
)
267 struct thread
*thread
=arch_os_get_current_thread();
268 /* Block all blockable signals. */
269 block_blockable_signals();
271 /* going back into Lisp */
272 foreign_function_call_active
= 0;
274 /* Undo dynamic binding of FREE_INTERRUPT_CONTEXT_INDEX */
278 /* Put the dynamic space free pointer back into the context. */
279 *os_context_register_addr(context
, reg_ALLOC
) =
280 (unsigned long) dynamic_space_free_pointer
;
284 /* a handler for the signal caused by execution of a trap opcode
285 * signalling an internal error */
287 interrupt_internal_error(int signal
, siginfo_t
*info
, os_context_t
*context
,
290 lispobj context_sap
= 0;
292 check_blockables_blocked_or_lose();
293 fake_foreign_function_call(context
);
295 /* Allocate the SAP object while the interrupts are still
297 if (internal_errors_enabled
) {
298 context_sap
= alloc_sap(context
);
301 thread_sigmask(SIG_SETMASK
, os_context_sigmask_addr(context
), 0);
303 if (internal_errors_enabled
) {
304 SHOW("in interrupt_internal_error");
306 /* Display some rudimentary debugging information about the
307 * error, so that even if the Lisp error handler gets badly
308 * confused, we have a chance to determine what's going on. */
309 describe_internal_error(context
);
311 funcall2(SymbolFunction(INTERNAL_ERROR
), context_sap
,
312 continuable
? T
: NIL
);
314 describe_internal_error(context
);
315 /* There's no good way to recover from an internal error
316 * before the Lisp error handling mechanism is set up. */
317 lose("internal error too early in init, can't recover");
319 undo_fake_foreign_function_call(context
); /* blocks signals again */
321 arch_skip_instruction(context
);
326 interrupt_handle_pending(os_context_t
*context
)
328 struct thread
*thread
;
329 struct interrupt_data
*data
;
331 check_blockables_blocked_or_lose();
332 check_interrupts_enabled_or_lose(context
);
334 thread
=arch_os_get_current_thread();
335 data
=thread
->interrupt_data
;
337 /* Pseudo atomic may trigger several times for a single interrupt,
338 * and while without-interrupts should not, a false trigger by
339 * pseudo-atomic may eat a pending handler even from
340 * without-interrupts. */
341 if (data
->pending_handler
) {
343 /* If we're here as the result of a pseudo-atomic as opposed
344 * to WITHOUT-INTERRUPTS, then INTERRUPT_PENDING is already
345 * NIL, because maybe_defer_handler sets
346 * PSEUDO_ATOMIC_INTERRUPTED only if interrupts are enabled.*/
347 SetSymbolValue(INTERRUPT_PENDING
, NIL
,thread
);
349 /* restore the saved signal mask from the original signal (the
350 * one that interrupted us during the critical section) into the
351 * os_context for the signal we're currently in the handler for.
352 * This should ensure that when we return from the handler the
353 * blocked signals are unblocked */
354 sigcopyset(os_context_sigmask_addr(context
), &data
->pending_mask
);
356 sigemptyset(&data
->pending_mask
);
357 /* This will break on sparc linux: the deferred handler really wants
358 * to be called with a void_context */
359 run_deferred_handler(data
,(void *)context
);
364 * the two main signal handlers:
365 * interrupt_handle_now(..)
366 * maybe_now_maybe_later(..)
368 * to which we have added interrupt_handle_now_handler(..). Why?
369 * Well, mostly because the SPARC/Linux platform doesn't quite do
370 * signals the way we want them done. The third argument in the
371 * handler isn't filled in by the kernel properly, so we fix it up
372 * ourselves in the arch_os_get_context(..) function; however, we only
373 * want to do this when we first hit the handler, and not when
374 * interrupt_handle_now(..) is being called from some other handler
375 * (when the fixup will already have been done). -- CSR, 2002-07-23
379 interrupt_handle_now(int signal
, siginfo_t
*info
, void *void_context
)
381 os_context_t
*context
= (os_context_t
*)void_context
;
382 struct thread
*thread
=arch_os_get_current_thread();
383 #if !defined(LISP_FEATURE_X86) && !defined(LISP_FEATURE_X86_64)
384 boolean were_in_lisp
;
386 union interrupt_handler handler
;
387 check_blockables_blocked_or_lose();
388 check_interrupts_enabled_or_lose(context
);
390 #ifdef LISP_FEATURE_LINUX
391 /* Under Linux on some architectures, we appear to have to restore
392 the FPU control word from the context, as after the signal is
393 delivered we appear to have a null FPU control word. */
394 os_restore_fp_control(context
);
396 handler
= thread
->interrupt_data
->interrupt_handlers
[signal
];
398 if (ARE_SAME_HANDLER(handler
.c
, SIG_IGN
)) {
402 #if !defined(LISP_FEATURE_X86) && !defined(LISP_FEATURE_X86_64)
403 were_in_lisp
= !foreign_function_call_active
;
407 fake_foreign_function_call(context
);
412 "/entering interrupt_handle_now(%d, info, context)\n",
416 if (ARE_SAME_HANDLER(handler
.c
, SIG_DFL
)) {
418 /* This can happen if someone tries to ignore or default one
419 * of the signals we need for runtime support, and the runtime
420 * support decides to pass on it. */
421 lose("no handler for signal %d in interrupt_handle_now(..)", signal
);
423 } else if (lowtag_of(handler
.lisp
) == FUN_POINTER_LOWTAG
) {
424 /* Once we've decided what to do about contexts in a
425 * return-elsewhere world (the original context will no longer
426 * be available; should we copy it or was nobody using it anyway?)
427 * then we should convert this to return-elsewhere */
429 /* CMUCL comment said "Allocate the SAPs while the interrupts
430 * are still disabled.". I (dan, 2003.08.21) assume this is
431 * because we're not in pseudoatomic and allocation shouldn't
432 * be interrupted. In which case it's no longer an issue as
433 * all our allocation from C now goes through a PA wrapper,
434 * but still, doesn't hurt */
436 lispobj info_sap
,context_sap
= alloc_sap(context
);
437 info_sap
= alloc_sap(info
);
438 /* Allow signals again. */
439 thread_sigmask(SIG_SETMASK
, os_context_sigmask_addr(context
), 0);
442 SHOW("calling Lisp-level handler");
445 funcall3(handler
.lisp
,
452 SHOW("calling C-level handler");
455 /* Allow signals again. */
456 thread_sigmask(SIG_SETMASK
, os_context_sigmask_addr(context
), 0);
458 (*handler
.c
)(signal
, info
, void_context
);
461 #if !defined(LISP_FEATURE_X86) && !defined(LISP_FEATURE_X86_64)
465 undo_fake_foreign_function_call(context
); /* block signals again */
470 "/returning from interrupt_handle_now(%d, info, context)\n",
475 /* This is called at the end of a critical section if the indications
476 * are that some signal was deferred during the section. Note that as
477 * far as C or the kernel is concerned we dealt with the signal
478 * already; we're just doing the Lisp-level processing now that we
482 run_deferred_handler(struct interrupt_data
*data
, void *v_context
) {
483 /* The pending_handler may enable interrupts (see
484 * interrupt_maybe_gc_int) and then another interrupt may hit,
485 * overwrite interrupt_data, so reset the pending handler before
486 * calling it. Trust the handler to finish with the siginfo before
487 * enabling interrupts. */
488 void (*pending_handler
) (int, siginfo_t
*, void*)=data
->pending_handler
;
489 data
->pending_handler
=0;
490 (*pending_handler
)(data
->pending_signal
,&(data
->pending_info
), v_context
);
494 maybe_defer_handler(void *handler
, struct interrupt_data
*data
,
495 int signal
, siginfo_t
*info
, os_context_t
*context
)
497 struct thread
*thread
=arch_os_get_current_thread();
499 check_blockables_blocked_or_lose();
501 if (SymbolValue(INTERRUPT_PENDING
,thread
) != NIL
)
502 lose("interrupt already pending");
503 /* If interrupts are disabled then INTERRUPT_PENDING is set and
504 * not PSEDUO_ATOMIC_INTERRUPTED. This is important for a pseudo
505 * atomic section inside a without-interrupts.
507 if (SymbolValue(INTERRUPTS_ENABLED
,thread
) == NIL
) {
508 store_signal_data_for_later(data
,handler
,signal
,info
,context
);
509 SetSymbolValue(INTERRUPT_PENDING
, T
,thread
);
512 "/maybe_defer_handler(%x,%d),thread=%ld: deferred\n",
513 (unsigned int)handler
,signal
,thread
->os_thread
));
517 /* a slightly confusing test. arch_pseudo_atomic_atomic() doesn't
518 * actually use its argument for anything on x86, so this branch
519 * may succeed even when context is null (gencgc alloc()) */
521 #if !defined(LISP_FEATURE_X86) && !defined(LISP_FEATURE_X86_64)
522 (!foreign_function_call_active
) &&
524 arch_pseudo_atomic_atomic(context
)) {
525 store_signal_data_for_later(data
,handler
,signal
,info
,context
);
526 arch_set_pseudo_atomic_interrupted(context
);
529 "/maybe_defer_handler(%x,%d),thread=%ld: deferred(PA)\n",
530 (unsigned int)handler
,signal
,thread
->os_thread
));
536 "/maybe_defer_handler(%x,%d),thread=%ld: not deferred\n",
537 (unsigned int)handler
,signal
,thread
->os_thread
));
543 store_signal_data_for_later (struct interrupt_data
*data
, void *handler
,
545 siginfo_t
*info
, os_context_t
*context
)
547 if (data
->pending_handler
)
548 lose("tried to overwrite pending interrupt handler %x with %x\n",
549 data
->pending_handler
, handler
);
551 lose("tried to defer null interrupt handler\n");
552 data
->pending_handler
= handler
;
553 data
->pending_signal
= signal
;
555 memcpy(&(data
->pending_info
), info
, sizeof(siginfo_t
));
557 /* the signal mask in the context (from before we were
558 * interrupted) is copied to be restored when
559 * run_deferred_handler happens. Then the usually-blocked
560 * signals are added to the mask in the context so that we are
561 * running with blocked signals when the handler returns */
562 sigcopyset(&(data
->pending_mask
),os_context_sigmask_addr(context
));
563 sigaddset_blockable(os_context_sigmask_addr(context
));
568 maybe_now_maybe_later(int signal
, siginfo_t
*info
, void *void_context
)
570 os_context_t
*context
= arch_os_get_context(&void_context
);
571 struct thread
*thread
=arch_os_get_current_thread();
572 struct interrupt_data
*data
=thread
->interrupt_data
;
573 #ifdef LISP_FEATURE_LINUX
574 os_restore_fp_control(context
);
576 if(maybe_defer_handler(interrupt_handle_now
,data
,
577 signal
,info
,context
))
579 interrupt_handle_now(signal
, info
, context
);
580 #ifdef LISP_FEATURE_DARWIN
581 /* Work around G5 bug */
582 DARWIN_FIX_CONTEXT(context
);
587 low_level_interrupt_handle_now(int signal
, siginfo_t
*info
, void *void_context
)
589 os_context_t
*context
= (os_context_t
*)void_context
;
590 struct thread
*thread
=arch_os_get_current_thread();
592 #ifdef LISP_FEATURE_LINUX
593 os_restore_fp_control(context
);
595 check_blockables_blocked_or_lose();
596 check_interrupts_enabled_or_lose(context
);
597 (*thread
->interrupt_data
->interrupt_low_level_handlers
[signal
])
598 (signal
, info
, void_context
);
599 #ifdef LISP_FEATURE_DARWIN
600 /* Work around G5 bug */
601 DARWIN_FIX_CONTEXT(context
);
606 low_level_maybe_now_maybe_later(int signal
, siginfo_t
*info
, void *void_context
)
608 os_context_t
*context
= arch_os_get_context(&void_context
);
609 struct thread
*thread
=arch_os_get_current_thread();
610 struct interrupt_data
*data
=thread
->interrupt_data
;
611 #ifdef LISP_FEATURE_LINUX
612 os_restore_fp_control(context
);
614 if(maybe_defer_handler(low_level_interrupt_handle_now
,data
,
615 signal
,info
,context
))
617 low_level_interrupt_handle_now(signal
, info
, context
);
618 #ifdef LISP_FEATURE_DARWIN
619 /* Work around G5 bug */
620 DARWIN_FIX_CONTEXT(context
);
624 #ifdef LISP_FEATURE_SB_THREAD
626 sig_stop_for_gc_handler(int signal
, siginfo_t
*info
, void *void_context
)
628 os_context_t
*context
= arch_os_get_context(&void_context
);
629 struct thread
*thread
=arch_os_get_current_thread();
633 /* need the context stored so it can have registers scavenged */
634 fake_foreign_function_call(context
);
637 for(i
=1;i
<NSIG
;i
++) sigaddset(&ss
,i
); /* Block everything. */
638 thread_sigmask(SIG_BLOCK
,&ss
,0);
640 /* The GC can't tell if a thread is a zombie, so this would be a
641 * good time to let the kernel reap any of our children in that
642 * awful state, to stop them from being waited for indefinitely.
643 * Userland reaping is done later when GC is finished */
644 if(thread
->state
!=STATE_RUNNING
) {
645 lose("sig_stop_for_gc_handler: wrong thread state: %ld\n",
646 fixnum_value(thread
->state
));
648 thread
->state
=STATE_SUSPENDED
;
650 sigemptyset(&ss
); sigaddset(&ss
,SIG_STOP_FOR_GC
);
652 if(thread
->state
!=STATE_SUSPENDED
) {
653 lose("sig_stop_for_gc_handler: wrong thread state on wakeup: %ld\n",
654 fixnum_value(thread
->state
));
656 thread
->state
=STATE_RUNNING
;
658 undo_fake_foreign_function_call(context
);
663 interrupt_handle_now_handler(int signal
, siginfo_t
*info
, void *void_context
)
665 os_context_t
*context
= arch_os_get_context(&void_context
);
666 interrupt_handle_now(signal
, info
, context
);
667 #ifdef LISP_FEATURE_DARWIN
668 DARWIN_FIX_CONTEXT(context
);
673 * stuff to detect and handle hitting the GC trigger
676 #ifndef LISP_FEATURE_GENCGC
677 /* since GENCGC has its own way to record trigger */
679 gc_trigger_hit(int signal
, siginfo_t
*info
, os_context_t
*context
)
681 if (current_auto_gc_trigger
== NULL
)
684 void *badaddr
=arch_get_bad_addr(signal
,info
,context
);
685 return (badaddr
>= (void *)current_auto_gc_trigger
&&
686 badaddr
<((void *)current_dynamic_space
+ DYNAMIC_SPACE_SIZE
));
691 /* manipulate the signal context and stack such that when the handler
692 * returns, it will call function instead of whatever it was doing
696 #if (defined(LISP_FEATURE_X86) || defined(LISP_FEATURE_X86_64))
697 int *context_eflags_addr(os_context_t
*context
);
700 extern lispobj
call_into_lisp(lispobj fun
, lispobj
*args
, int nargs
);
701 extern void post_signal_tramp(void);
702 void arrange_return_to_lisp_function(os_context_t
*context
, lispobj function
)
704 #if !(defined(LISP_FEATURE_X86) || defined(LISP_FEATURE_X86_64))
705 void * fun
=native_pointer(function
);
706 void *code
= &(((struct simple_fun
*) fun
)->code
);
709 /* Build a stack frame showing `interrupted' so that the
710 * user's backtrace makes (as much) sense (as usual) */
712 /* FIXME: what about restoring fp state? */
713 /* FIXME: what about restoring errno? */
714 #ifdef LISP_FEATURE_X86
715 /* Suppose the existence of some function that saved all
716 * registers, called call_into_lisp, then restored GP registers and
717 * returned. It would look something like this:
725 pushl {address of function to call}
726 call 0x8058db0 <call_into_lisp>
733 * What we do here is set up the stack that call_into_lisp would
734 * expect to see if it had been called by this code, and frob the
735 * signal context so that signal return goes directly to call_into_lisp,
736 * and when that function (and the lisp function it invoked) returns,
737 * it returns to the second half of this imaginary function which
738 * restores all registers and returns to C
740 * For this to work, the latter part of the imaginary function
741 * must obviously exist in reality. That would be post_signal_tramp
744 uint32_t *sp
=(uint32_t *)*os_context_register_addr(context
,reg_ESP
);
746 /* return address for call_into_lisp: */
747 *(sp
-15) = (uint32_t)post_signal_tramp
;
748 *(sp
-14) = function
; /* args for call_into_lisp : function*/
749 *(sp
-13) = 0; /* arg array */
750 *(sp
-12) = 0; /* no. args */
751 /* this order matches that used in POPAD */
752 *(sp
-11)=*os_context_register_addr(context
,reg_EDI
);
753 *(sp
-10)=*os_context_register_addr(context
,reg_ESI
);
755 *(sp
-9)=*os_context_register_addr(context
,reg_ESP
)-8;
756 /* POPAD ignores the value of ESP: */
758 *(sp
-7)=*os_context_register_addr(context
,reg_EBX
);
760 *(sp
-6)=*os_context_register_addr(context
,reg_EDX
);
761 *(sp
-5)=*os_context_register_addr(context
,reg_ECX
);
762 *(sp
-4)=*os_context_register_addr(context
,reg_EAX
);
763 *(sp
-3)=*context_eflags_addr(context
);
764 *(sp
-2)=*os_context_register_addr(context
,reg_EBP
);
765 *(sp
-1)=*os_context_pc_addr(context
);
767 #elif defined(LISP_FEATURE_X86_64)
768 uint64_t *sp
=(uint64_t *)*os_context_register_addr(context
,reg_RSP
);
769 /* return address for call_into_lisp: */
770 *(sp
-18) = (uint64_t)post_signal_tramp
;
772 *(sp
-17)=*os_context_register_addr(context
,reg_R15
);
773 *(sp
-16)=*os_context_register_addr(context
,reg_R14
);
774 *(sp
-15)=*os_context_register_addr(context
,reg_R13
);
775 *(sp
-14)=*os_context_register_addr(context
,reg_R12
);
776 *(sp
-13)=*os_context_register_addr(context
,reg_R11
);
777 *(sp
-12)=*os_context_register_addr(context
,reg_R10
);
778 *(sp
-11)=*os_context_register_addr(context
,reg_R9
);
779 *(sp
-10)=*os_context_register_addr(context
,reg_R8
);
780 *(sp
-9)=*os_context_register_addr(context
,reg_RDI
);
781 *(sp
-8)=*os_context_register_addr(context
,reg_RSI
);
782 /* skip RBP and RSP */
783 *(sp
-7)=*os_context_register_addr(context
,reg_RBX
);
784 *(sp
-6)=*os_context_register_addr(context
,reg_RDX
);
785 *(sp
-5)=*os_context_register_addr(context
,reg_RCX
);
786 *(sp
-4)=*os_context_register_addr(context
,reg_RAX
);
787 *(sp
-3)=*context_eflags_addr(context
);
788 *(sp
-2)=*os_context_register_addr(context
,reg_RBP
);
789 *(sp
-1)=*os_context_pc_addr(context
);
791 *os_context_register_addr(context
,reg_RDI
) =
792 (os_context_register_t
)function
; /* function */
793 *os_context_register_addr(context
,reg_RSI
) = 0; /* arg. array */
794 *os_context_register_addr(context
,reg_RDX
) = 0; /* no. args */
796 struct thread
*th
=arch_os_get_current_thread();
797 build_fake_control_stack_frames(th
,context
);
800 #ifdef LISP_FEATURE_X86
801 *os_context_pc_addr(context
) = (os_context_register_t
)call_into_lisp
;
802 *os_context_register_addr(context
,reg_ECX
) = 0;
803 *os_context_register_addr(context
,reg_EBP
) = (os_context_register_t
)(sp
-2);
805 *os_context_register_addr(context
,reg_UESP
) =
806 (os_context_register_t
)(sp
-15);
808 *os_context_register_addr(context
,reg_ESP
) = (os_context_register_t
)(sp
-15);
810 #elif defined(LISP_FEATURE_X86_64)
811 *os_context_pc_addr(context
) = (os_context_register_t
)call_into_lisp
;
812 *os_context_register_addr(context
,reg_RCX
) = 0;
813 *os_context_register_addr(context
,reg_RBP
) = (os_context_register_t
)(sp
-2);
814 *os_context_register_addr(context
,reg_RSP
) = (os_context_register_t
)(sp
-18);
816 /* this much of the calling convention is common to all
818 *os_context_pc_addr(context
) = (os_context_register_t
)code
;
819 *os_context_register_addr(context
,reg_NARGS
) = 0;
820 *os_context_register_addr(context
,reg_LIP
) = (os_context_register_t
)code
;
821 *os_context_register_addr(context
,reg_CFP
) =
822 (os_context_register_t
)current_control_frame_pointer
;
824 #ifdef ARCH_HAS_NPC_REGISTER
825 *os_context_npc_addr(context
) =
826 4 + *os_context_pc_addr(context
);
828 #ifdef LISP_FEATURE_SPARC
829 *os_context_register_addr(context
,reg_CODE
) =
830 (os_context_register_t
)(fun
+ FUN_POINTER_LOWTAG
);
834 #ifdef LISP_FEATURE_SB_THREAD
835 void interrupt_thread_handler(int num
, siginfo_t
*info
, void *v_context
)
837 os_context_t
*context
= (os_context_t
*)arch_os_get_context(&v_context
);
838 /* The order of interrupt execution is peculiar. If thread A
839 * interrupts thread B with I1, I2 and B for some reason recieves
840 * I1 when FUN2 is already on the list, then it is FUN2 that gets
841 * to run first. But when FUN2 is run SIG_INTERRUPT_THREAD is
842 * enabled again and I2 hits pretty soon in FUN2 and run
843 * FUN1. This is of course just one scenario, and the order of
844 * thread interrupt execution is undefined. */
845 struct thread
*th
=arch_os_get_current_thread();
847 if (th
->state
!= STATE_RUNNING
)
848 lose("interrupt_thread_handler: thread %ld in wrong state: %d\n",
849 th
->os_thread
,fixnum_value(th
->state
));
850 get_spinlock(&th
->interrupt_fun_lock
,(long)th
);
851 c
=((struct cons
*)native_pointer(th
->interrupt_fun
));
852 arrange_return_to_lisp_function(context
,c
->car
);
853 th
->interrupt_fun
=c
->cdr
;
854 release_spinlock(&th
->interrupt_fun_lock
);
859 /* KLUDGE: Theoretically the approach we use for undefined alien
860 * variables should work for functions as well, but on PPC/Darwin
861 * we get bus error at bogus addresses instead, hence this workaround,
862 * that has the added benefit of automatically discriminating between
863 * functions and variables.
865 void undefined_alien_function() {
866 funcall0(SymbolFunction(UNDEFINED_ALIEN_FUNCTION_ERROR
));
869 boolean
handle_guard_page_triggered(os_context_t
*context
,os_vm_address_t addr
)
871 struct thread
*th
=arch_os_get_current_thread();
873 /* note the os_context hackery here. When the signal handler returns,
874 * it won't go back to what it was doing ... */
875 if(addr
>= CONTROL_STACK_GUARD_PAGE(th
) &&
876 addr
< CONTROL_STACK_GUARD_PAGE(th
) + os_vm_page_size
) {
877 /* We hit the end of the control stack: disable guard page
878 * protection so the error handler has some headroom, protect the
879 * previous page so that we can catch returns from the guard page
881 protect_control_stack_guard_page(th
,0);
882 protect_control_stack_return_guard_page(th
,1);
884 arrange_return_to_lisp_function
885 (context
, SymbolFunction(CONTROL_STACK_EXHAUSTED_ERROR
));
888 else if(addr
>= CONTROL_STACK_RETURN_GUARD_PAGE(th
) &&
889 addr
< CONTROL_STACK_RETURN_GUARD_PAGE(th
) + os_vm_page_size
) {
890 /* We're returning from the guard page: reprotect it, and
891 * unprotect this one. This works even if we somehow missed
892 * the return-guard-page, and hit it on our way to new
893 * exhaustion instead. */
894 protect_control_stack_guard_page(th
,1);
895 protect_control_stack_return_guard_page(th
,0);
898 else if (addr
>= undefined_alien_address
&&
899 addr
< undefined_alien_address
+ os_vm_page_size
) {
900 arrange_return_to_lisp_function
901 (context
, SymbolFunction(UNDEFINED_ALIEN_VARIABLE_ERROR
));
907 #ifndef LISP_FEATURE_GENCGC
908 /* This function gets called from the SIGSEGV (for e.g. Linux, NetBSD, &
909 * OpenBSD) or SIGBUS (for e.g. FreeBSD) handler. Here we check
910 * whether the signal was due to treading on the mprotect()ed zone -
911 * and if so, arrange for a GC to happen. */
912 extern unsigned long bytes_consed_between_gcs
; /* gc-common.c */
915 interrupt_maybe_gc(int signal
, siginfo_t
*info
, void *void_context
)
917 os_context_t
*context
=(os_context_t
*) void_context
;
918 struct thread
*th
=arch_os_get_current_thread();
919 struct interrupt_data
*data
=
920 th
? th
->interrupt_data
: global_interrupt_data
;
922 if(!data
->pending_handler
&& !foreign_function_call_active
&&
923 gc_trigger_hit(signal
, info
, context
)){
924 clear_auto_gc_trigger();
925 if(!maybe_defer_handler(interrupt_maybe_gc_int
,
926 data
,signal
,info
,void_context
))
927 interrupt_maybe_gc_int(signal
,info
,void_context
);
935 /* this is also used by gencgc, in alloc() */
937 interrupt_maybe_gc_int(int signal
, siginfo_t
*info
, void *void_context
)
939 os_context_t
*context
=(os_context_t
*) void_context
;
941 check_blockables_blocked_or_lose();
942 fake_foreign_function_call(context
);
944 /* SUB-GC may return without GCing if *GC-INHIBIT* is set, in
945 * which case we will be running with no gc trigger barrier
946 * thing for a while. But it shouldn't be long until the end
949 * FIXME: It would be good to protect the end of dynamic space
950 * and signal a storage condition from there.
953 /* restore the signal mask from the interrupted context before
954 * calling into Lisp */
956 thread_sigmask(SIG_SETMASK
, os_context_sigmask_addr(context
), 0);
958 funcall0(SymbolFunction(SUB_GC
));
960 undo_fake_foreign_function_call(context
);
966 * noise to install handlers
970 undoably_install_low_level_interrupt_handler (int signal
,
976 struct thread
*th
=arch_os_get_current_thread();
977 struct interrupt_data
*data
=
978 th
? th
->interrupt_data
: global_interrupt_data
;
980 if (0 > signal
|| signal
>= NSIG
) {
981 lose("bad signal number %d", signal
);
984 if (sigismember(&blockable_sigset
,signal
))
985 sa
.sa_sigaction
= low_level_maybe_now_maybe_later
;
987 sa
.sa_sigaction
= handler
;
989 sigemptyset(&sa
.sa_mask
);
990 sigaddset_blockable(&sa
.sa_mask
);
991 sa
.sa_flags
= SA_SIGINFO
| SA_RESTART
;
992 #ifdef LISP_FEATURE_C_STACK_IS_CONTROL_STACK
993 if((signal
==SIG_MEMORY_FAULT
)
994 #ifdef SIG_INTERRUPT_THREAD
995 || (signal
==SIG_INTERRUPT_THREAD
)
998 sa
.sa_flags
|= SA_ONSTACK
;
1001 sigaction(signal
, &sa
, NULL
);
1002 data
->interrupt_low_level_handlers
[signal
] =
1003 (ARE_SAME_HANDLER(handler
, SIG_DFL
) ? 0 : handler
);
1006 /* This is called from Lisp. */
1008 install_handler(int signal
, void handler(int, siginfo_t
*, void*))
1010 struct sigaction sa
;
1012 union interrupt_handler oldhandler
;
1013 struct thread
*th
=arch_os_get_current_thread();
1014 struct interrupt_data
*data
=
1015 th
? th
->interrupt_data
: global_interrupt_data
;
1017 FSHOW((stderr
, "/entering POSIX install_handler(%d, ..)\n", signal
));
1020 sigaddset(&new, signal
);
1021 thread_sigmask(SIG_BLOCK
, &new, &old
);
1024 sigaddset_blockable(&new);
1026 FSHOW((stderr
, "/data->interrupt_low_level_handlers[signal]=%x\n",
1027 (unsigned int)data
->interrupt_low_level_handlers
[signal
]));
1028 if (data
->interrupt_low_level_handlers
[signal
]==0) {
1029 if (ARE_SAME_HANDLER(handler
, SIG_DFL
) ||
1030 ARE_SAME_HANDLER(handler
, SIG_IGN
)) {
1031 sa
.sa_sigaction
= handler
;
1032 } else if (sigismember(&new, signal
)) {
1033 sa
.sa_sigaction
= maybe_now_maybe_later
;
1035 sa
.sa_sigaction
= interrupt_handle_now_handler
;
1038 sigemptyset(&sa
.sa_mask
);
1039 sigaddset_blockable(&sa
.sa_mask
);
1040 sa
.sa_flags
= SA_SIGINFO
| SA_RESTART
;
1041 sigaction(signal
, &sa
, NULL
);
1044 oldhandler
= data
->interrupt_handlers
[signal
];
1045 data
->interrupt_handlers
[signal
].c
= handler
;
1047 thread_sigmask(SIG_SETMASK
, &old
, 0);
1049 FSHOW((stderr
, "/leaving POSIX install_handler(%d, ..)\n", signal
));
1051 return (unsigned long)oldhandler
.lisp
;
1058 SHOW("entering interrupt_init()");
1059 sigemptyset(&blockable_sigset
);
1060 sigaddset_blockable(&blockable_sigset
);
1062 global_interrupt_data
=calloc(sizeof(struct interrupt_data
), 1);
1064 /* Set up high level handler information. */
1065 for (i
= 0; i
< NSIG
; i
++) {
1066 global_interrupt_data
->interrupt_handlers
[i
].c
=
1067 /* (The cast here blasts away the distinction between
1068 * SA_SIGACTION-style three-argument handlers and
1069 * signal(..)-style one-argument handlers, which is OK
1070 * because it works to call the 1-argument form where the
1071 * 3-argument form is expected.) */
1072 (void (*)(int, siginfo_t
*, void*))SIG_DFL
;
1075 SHOW("returning from interrupt_init()");