X-Git-Url: http://repo.macrolet.net/gitweb/?a=blobdiff_plain;f=src%2Fruntime%2Finterrupt.c;h=6a5205337553a916b33e090ed1e11592205136a4;hb=7fb597b585fc715537ea644f7d84440eca217ca1;hp=1fa25473344b3c8bb2bb36ab5a76c1f408193b1a;hpb=c2144640eeb8875228a121c76cc778e2af661064;p=sbcl.git diff --git a/src/runtime/interrupt.c b/src/runtime/interrupt.c index 1fa2547..6a52053 100644 --- a/src/runtime/interrupt.c +++ b/src/runtime/interrupt.c @@ -40,16 +40,18 @@ * * - WHN 20000728, dan 20010128 */ +#include "sbcl.h" #include #include #include #include #include +#ifndef LISP_FEATURE_WIN32 #include +#endif #include -#include "sbcl.h" #include "runtime.h" #include "arch.h" #include "os.h" @@ -68,14 +70,16 @@ -void run_deferred_handler(struct interrupt_data *data, void *v_context) ; +static void run_deferred_handler(struct interrupt_data *data, void *v_context); +#ifndef LISP_FEATURE_WIN32 static void store_signal_data_for_later (struct interrupt_data *data, void *handler, int signal, siginfo_t *info, os_context_t *context); boolean interrupt_maybe_gc_int(int signal, siginfo_t *info, void *v_context); -void sigaddset_blockable(sigset_t *s) +void +sigaddset_deferrable(sigset_t *s) { sigaddset(s, SIGHUP); sigaddset(s, SIGINT); @@ -83,7 +87,6 @@ void sigaddset_blockable(sigset_t *s) sigaddset(s, SIGPIPE); sigaddset(s, SIGALRM); sigaddset(s, SIGURG); - sigaddset(s, SIGFPE); sigaddset(s, SIGTSTP); sigaddset(s, SIGCHLD); sigaddset(s, SIGIO); @@ -95,37 +98,52 @@ void sigaddset_blockable(sigset_t *s) sigaddset(s, SIGUSR1); sigaddset(s, SIGUSR2); #ifdef LISP_FEATURE_SB_THREAD - sigaddset(s, SIG_STOP_FOR_GC); sigaddset(s, SIG_INTERRUPT_THREAD); #endif } +void +sigaddset_blockable(sigset_t *s) +{ + sigaddset_deferrable(s); +#ifdef LISP_FEATURE_SB_THREAD + sigaddset(s, SIG_STOP_FOR_GC); +#endif +} + +/* initialized in interrupt_init */ +static sigset_t deferrable_sigset; static sigset_t blockable_sigset; +#endif -inline static void check_blockables_blocked_or_lose() +void +check_blockables_blocked_or_lose() { +#ifndef LISP_FEATURE_WIN32 /* Get the current sigmask, by blocking the empty set. */ sigset_t empty,current; int i; sigemptyset(&empty); thread_sigmask(SIG_BLOCK, &empty, ¤t); - for(i=0;i= MAX_INTERRUPTS) { - lose("maximum interrupt nesting depth (%d) exceeded", MAX_INTERRUPTS); + lose("maximum interrupt nesting depth (%d) exceeded\n", MAX_INTERRUPTS); } bind_variable(FREE_INTERRUPT_CONTEXT_INDEX, @@ -259,7 +289,6 @@ fake_foreign_function_call(os_context_t *context) /* blocks all blockable signals. If you are calling from a signal handler, * the usual signal mask will be restored from the context when the handler * finishes. Otherwise, be careful */ - void undo_fake_foreign_function_call(os_context_t *context) { @@ -286,39 +315,38 @@ void interrupt_internal_error(int signal, siginfo_t *info, os_context_t *context, boolean continuable) { - lispobj context_sap = 0; + lispobj context_sap; - check_blockables_blocked_or_lose(); fake_foreign_function_call(context); + if (!internal_errors_enabled) { + describe_internal_error(context); + /* There's no good way to recover from an internal error + * before the Lisp error handling mechanism is set up. */ + lose("internal error too early in init, can't recover\n"); + } + /* Allocate the SAP object while the interrupts are still * disabled. */ - if (internal_errors_enabled) { - context_sap = alloc_sap(context); - } + context_sap = alloc_sap(context); +#ifndef LISP_FEATURE_WIN32 thread_sigmask(SIG_SETMASK, os_context_sigmask_addr(context), 0); +#endif - if (internal_errors_enabled) { - SHOW("in interrupt_internal_error"); + SHOW("in interrupt_internal_error"); #ifdef QSHOW - /* Display some rudimentary debugging information about the - * error, so that even if the Lisp error handler gets badly - * confused, we have a chance to determine what's going on. */ - describe_internal_error(context); + /* Display some rudimentary debugging information about the + * error, so that even if the Lisp error handler gets badly + * confused, we have a chance to determine what's going on. */ + describe_internal_error(context); #endif - funcall2(SymbolFunction(INTERNAL_ERROR), context_sap, - continuable ? T : NIL); - } else { - describe_internal_error(context); - /* There's no good way to recover from an internal error - * before the Lisp error handling mechanism is set up. */ - lose("internal error too early in init, can't recover"); - } + funcall2(SymbolFunction(INTERNAL_ERROR), context_sap, + continuable ? T : NIL); + undo_fake_foreign_function_call(context); /* blocks signals again */ - if (continuable) { + if (continuable) arch_skip_instruction(context); - } } void @@ -328,34 +356,72 @@ interrupt_handle_pending(os_context_t *context) struct interrupt_data *data; check_blockables_blocked_or_lose(); - check_interrupts_enabled_or_lose(context); thread=arch_os_get_current_thread(); data=thread->interrupt_data; - /* Pseudo atomic may trigger several times for a single interrupt, - * and while without-interrupts should not, a false trigger by - * pseudo-atomic may eat a pending handler even from - * without-interrupts. */ - if (data->pending_handler) { - - /* If we're here as the result of a pseudo-atomic as opposed - * to WITHOUT-INTERRUPTS, then INTERRUPT_PENDING is already - * NIL, because maybe_defer_handler sets - * PSEUDO_ATOMIC_INTERRUPTED only if interrupts are enabled.*/ - SetSymbolValue(INTERRUPT_PENDING, NIL,thread); - - /* restore the saved signal mask from the original signal (the - * one that interrupted us during the critical section) into the - * os_context for the signal we're currently in the handler for. - * This should ensure that when we return from the handler the - * blocked signals are unblocked */ - sigcopyset(os_context_sigmask_addr(context), &data->pending_mask); - - sigemptyset(&data->pending_mask); - /* This will break on sparc linux: the deferred handler really wants - * to be called with a void_context */ - run_deferred_handler(data,(void *)context); +#if defined(LISP_FEATURE_X86) || defined(LISP_FEATURE_X86_64) + /* If pseudo_atomic_interrupted is set then the interrupt is going + * to be handled now, ergo it's safe to clear it. */ + arch_clear_pseudo_atomic_interrupted(context); +#endif + + if (SymbolValue(GC_INHIBIT,thread)==NIL) { +#ifdef LISP_FEATURE_SB_THREAD + if (SymbolValue(STOP_FOR_GC_PENDING,thread) != NIL) { + /* another thread has already initiated a gc, this attempt + * might as well be cancelled */ + SetSymbolValue(GC_PENDING,NIL,thread); + SetSymbolValue(STOP_FOR_GC_PENDING,NIL,thread); + sig_stop_for_gc_handler(SIG_STOP_FOR_GC,NULL,context); + } else +#endif + if (SymbolValue(GC_PENDING,thread) != NIL) { + /* GC_PENDING is cleared in SUB-GC, or if another thread + * is doing a gc already we will get a SIG_STOP_FOR_GC and + * that will clear it. */ + interrupt_maybe_gc_int(0,NULL,context); + } + check_blockables_blocked_or_lose(); + } + + /* we may be here only to do the gc stuff, if interrupts are + * enabled run the pending handler */ + if (!((SymbolValue(INTERRUPTS_ENABLED,thread) == NIL) || + ( +#if !defined(LISP_FEATURE_X86) && !defined(LISP_FEATURE_X86_64) + (!foreign_function_call_active) && +#endif + arch_pseudo_atomic_atomic(context)))) { + + /* There may be no pending handler, because it was only a gc + * that had to be executed or because pseudo atomic triggered + * twice for a single interrupt. For the interested reader, + * that may happen if an interrupt hits after the interrupted + * flag is cleared but before pseduo-atomic is set and a + * pseudo atomic is interrupted in that interrupt. */ + if (data->pending_handler) { + + /* If we're here as the result of a pseudo-atomic as opposed + * to WITHOUT-INTERRUPTS, then INTERRUPT_PENDING is already + * NIL, because maybe_defer_handler sets + * PSEUDO_ATOMIC_INTERRUPTED only if interrupts are enabled.*/ + SetSymbolValue(INTERRUPT_PENDING, NIL,thread); + +#ifndef LISP_FEATURE_WIN32 + /* restore the saved signal mask from the original signal (the + * one that interrupted us during the critical section) into the + * os_context for the signal we're currently in the handler for. + * This should ensure that when we return from the handler the + * blocked signals are unblocked */ + sigcopyset(os_context_sigmask_addr(context), &data->pending_mask); + + sigemptyset(&data->pending_mask); +#endif + /* This will break on sparc linux: the deferred handler really wants + * to be called with a void_context */ + run_deferred_handler(data,(void *)context); + } } } @@ -378,13 +444,15 @@ void interrupt_handle_now(int signal, siginfo_t *info, void *void_context) { os_context_t *context = (os_context_t*)void_context; - struct thread *thread=arch_os_get_current_thread(); #if !defined(LISP_FEATURE_X86) && !defined(LISP_FEATURE_X86_64) boolean were_in_lisp; #endif union interrupt_handler handler; check_blockables_blocked_or_lose(); - check_interrupts_enabled_or_lose(context); +#ifndef LISP_FEATURE_WIN32 + if (sigismember(&deferrable_sigset,signal)) + check_interrupts_enabled_or_lose(context); +#endif #ifdef LISP_FEATURE_LINUX /* Under Linux on some architectures, we appear to have to restore @@ -392,7 +460,7 @@ interrupt_handle_now(int signal, siginfo_t *info, void *void_context) delivered we appear to have a null FPU control word. */ os_restore_fp_control(context); #endif - handler = thread->interrupt_data->interrupt_handlers[signal]; + handler = interrupt_handlers[signal]; if (ARE_SAME_HANDLER(handler.c, SIG_IGN)) { return; @@ -406,18 +474,16 @@ interrupt_handle_now(int signal, siginfo_t *info, void *void_context) fake_foreign_function_call(context); } -#ifdef QSHOW_SIGNALS - FSHOW((stderr, - "/entering interrupt_handle_now(%d, info, context)\n", - signal)); -#endif + FSHOW_SIGNAL((stderr, + "/entering interrupt_handle_now(%d, info, context)\n", + signal)); if (ARE_SAME_HANDLER(handler.c, SIG_DFL)) { /* This can happen if someone tries to ignore or default one * of the signals we need for runtime support, and the runtime * support decides to pass on it. */ - lose("no handler for signal %d in interrupt_handle_now(..)", signal); + lose("no handler for signal %d in interrupt_handle_now(..)\n", signal); } else if (lowtag_of(handler.lisp) == FUN_POINTER_LOWTAG) { /* Once we've decided what to do about contexts in a @@ -430,29 +496,38 @@ interrupt_handle_now(int signal, siginfo_t *info, void *void_context) * because we're not in pseudoatomic and allocation shouldn't * be interrupted. In which case it's no longer an issue as * all our allocation from C now goes through a PA wrapper, - * but still, doesn't hurt */ + * but still, doesn't hurt. + * + * Yeah, but non-gencgc platforms don't really wrap allocation + * in PA. MG - 2005-08-29 */ lispobj info_sap,context_sap = alloc_sap(context); info_sap = alloc_sap(info); - /* Allow signals again. */ - thread_sigmask(SIG_SETMASK, os_context_sigmask_addr(context), 0); - -#ifdef QSHOW_SIGNALS - SHOW("calling Lisp-level handler"); + /* Leave deferrable signals blocked, the handler itself will + * allow signals again when it sees fit. */ +#ifdef LISP_FEATURE_SB_THREAD + { + sigset_t unblock; + sigemptyset(&unblock); + sigaddset(&unblock, SIG_STOP_FOR_GC); + thread_sigmask(SIG_UNBLOCK, &unblock, 0); + } #endif + FSHOW_SIGNAL((stderr,"/calling Lisp-level handler\n")); + funcall3(handler.lisp, make_fixnum(signal), info_sap, context_sap); } else { -#ifdef QSHOW_SIGNALS - SHOW("calling C-level handler"); -#endif + FSHOW_SIGNAL((stderr,"/calling C-level handler\n")); +#ifndef LISP_FEATURE_WIN32 /* Allow signals again. */ thread_sigmask(SIG_SETMASK, os_context_sigmask_addr(context), 0); +#endif (*handler.c)(signal, info, void_context); } @@ -464,11 +539,9 @@ interrupt_handle_now(int signal, siginfo_t *info, void *void_context) undo_fake_foreign_function_call(context); /* block signals again */ } -#ifdef QSHOW_SIGNALS - FSHOW((stderr, - "/returning from interrupt_handle_now(%d, info, context)\n", - signal)); -#endif + FSHOW_SIGNAL((stderr, + "/returning from interrupt_handle_now(%d, info, context)\n", + signal)); } /* This is called at the end of a critical section if the indications @@ -476,19 +549,18 @@ interrupt_handle_now(int signal, siginfo_t *info, void *void_context) * far as C or the kernel is concerned we dealt with the signal * already; we're just doing the Lisp-level processing now that we * put off then */ - -void +static void run_deferred_handler(struct interrupt_data *data, void *v_context) { - /* The pending_handler may enable interrupts (see - * interrupt_maybe_gc_int) and then another interrupt may hit, - * overwrite interrupt_data, so reset the pending handler before - * calling it. Trust the handler to finish with the siginfo before - * enabling interrupts. */ + /* The pending_handler may enable interrupts and then another + * interrupt may hit, overwrite interrupt_data, so reset the + * pending handler before calling it. Trust the handler to finish + * with the siginfo before enabling interrupts. */ void (*pending_handler) (int, siginfo_t*, void*)=data->pending_handler; data->pending_handler=0; (*pending_handler)(data->pending_signal,&(data->pending_info), v_context); } +#ifndef LISP_FEATURE_WIN32 boolean maybe_defer_handler(void *handler, struct interrupt_data *data, int signal, siginfo_t *info, os_context_t *context) @@ -498,19 +570,18 @@ maybe_defer_handler(void *handler, struct interrupt_data *data, check_blockables_blocked_or_lose(); if (SymbolValue(INTERRUPT_PENDING,thread) != NIL) - lose("interrupt already pending"); + lose("interrupt already pending\n"); /* If interrupts are disabled then INTERRUPT_PENDING is set and * not PSEDUO_ATOMIC_INTERRUPTED. This is important for a pseudo - * atomic section inside a without-interrupts. + * atomic section inside a WITHOUT-INTERRUPTS. */ if (SymbolValue(INTERRUPTS_ENABLED,thread) == NIL) { store_signal_data_for_later(data,handler,signal,info,context); SetSymbolValue(INTERRUPT_PENDING, T,thread); -#ifdef QSHOW_SIGNALS - FSHOW((stderr, - "/maybe_defer_handler(%x,%d),thread=%ld: deferred\n", - (unsigned int)handler,signal,thread->os_thread)); -#endif + FSHOW_SIGNAL((stderr, + "/maybe_defer_handler(%x,%d),thread=%lu: deferred\n", + (unsigned int)handler,signal, + (unsigned long)thread->os_thread)); return 1; } /* a slightly confusing test. arch_pseudo_atomic_atomic() doesn't @@ -518,23 +589,27 @@ maybe_defer_handler(void *handler, struct interrupt_data *data, * may succeed even when context is null (gencgc alloc()) */ if ( #if !defined(LISP_FEATURE_X86) && !defined(LISP_FEATURE_X86_64) + /* FIXME: this foreign_function_call_active test is dubious at + * best. If a foreign call is made in a pseudo atomic section + * (?) or more likely a pseudo atomic section is in a foreign + * call then an interrupt is executed immediately. Maybe it + * has to do with C code not maintaining pseudo atomic + * properly. MG - 2005-08-10 */ (!foreign_function_call_active) && #endif arch_pseudo_atomic_atomic(context)) { store_signal_data_for_later(data,handler,signal,info,context); arch_set_pseudo_atomic_interrupted(context); -#ifdef QSHOW_SIGNALS - FSHOW((stderr, - "/maybe_defer_handler(%x,%d),thread=%ld: deferred(PA)\n", - (unsigned int)handler,signal,thread->os_thread)); -#endif + FSHOW_SIGNAL((stderr, + "/maybe_defer_handler(%x,%d),thread=%lu: deferred(PA)\n", + (unsigned int)handler,signal, + (unsigned long)thread->os_thread)); return 1; } -#ifdef QSHOW_SIGNALS - FSHOW((stderr, - "/maybe_defer_handler(%x,%d),thread=%ld: not deferred\n", - (unsigned int)handler,signal,thread->os_thread)); -#endif + FSHOW_SIGNAL((stderr, + "/maybe_defer_handler(%x,%d),thread=%lu: not deferred\n", + (unsigned int)handler,signal, + (unsigned long)thread->os_thread)); return 0; } @@ -559,7 +634,7 @@ store_signal_data_for_later (struct interrupt_data *data, void *handler, * signals are added to the mask in the context so that we are * running with blocked signals when the handler returns */ sigcopyset(&(data->pending_mask),os_context_sigmask_addr(context)); - sigaddset_blockable(os_context_sigmask_addr(context)); + sigaddset_deferrable(os_context_sigmask_addr(context)); } } @@ -572,8 +647,7 @@ maybe_now_maybe_later(int signal, siginfo_t *info, void *void_context) #ifdef LISP_FEATURE_LINUX os_restore_fp_control(context); #endif - if(maybe_defer_handler(interrupt_handle_now,data, - signal,info,context)) + if(maybe_defer_handler(interrupt_handle_now,data,signal,info,context)) return; interrupt_handle_now(signal, info, context); #ifdef LISP_FEATURE_DARWIN @@ -586,15 +660,13 @@ static void low_level_interrupt_handle_now(int signal, siginfo_t *info, void *void_context) { os_context_t *context = (os_context_t*)void_context; - struct thread *thread=arch_os_get_current_thread(); #ifdef LISP_FEATURE_LINUX os_restore_fp_control(context); #endif check_blockables_blocked_or_lose(); check_interrupts_enabled_or_lose(context); - (*thread->interrupt_data->interrupt_low_level_handlers[signal]) - (signal, info, void_context); + interrupt_low_level_handlers[signal](signal, info, void_context); #ifdef LISP_FEATURE_DARWIN /* Work around G5 bug */ DARWIN_FIX_CONTEXT(context); @@ -619,42 +691,50 @@ low_level_maybe_now_maybe_later(int signal, siginfo_t *info, void *void_context) DARWIN_FIX_CONTEXT(context); #endif } +#endif #ifdef LISP_FEATURE_SB_THREAD + void sig_stop_for_gc_handler(int signal, siginfo_t *info, void *void_context) { os_context_t *context = arch_os_get_context(&void_context); struct thread *thread=arch_os_get_current_thread(); sigset_t ss; - int i; - /* need the context stored so it can have registers scavenged */ - fake_foreign_function_call(context); + if ((arch_pseudo_atomic_atomic(context) || + SymbolValue(GC_INHIBIT,thread) != NIL)) { + SetSymbolValue(STOP_FOR_GC_PENDING,T,thread); + if (SymbolValue(GC_INHIBIT,thread) == NIL) + arch_set_pseudo_atomic_interrupted(context); + FSHOW_SIGNAL((stderr,"thread=%lu sig_stop_for_gc deferred\n", + thread->os_thread)); + } else { + /* need the context stored so it can have registers scavenged */ + fake_foreign_function_call(context); - sigemptyset(&ss); - for(i=1;istate!=STATE_RUNNING) { - lose("sig_stop_for_gc_handler: wrong thread state: %ld\n", - fixnum_value(thread->state)); - } - thread->state=STATE_SUSPENDED; + sigfillset(&ss); /* Block everything. */ + thread_sigmask(SIG_BLOCK,&ss,0); - sigemptyset(&ss); sigaddset(&ss,SIG_STOP_FOR_GC); - sigwaitinfo(&ss,0); - if(thread->state!=STATE_SUSPENDED) { - lose("sig_stop_for_gc_handler: wrong thread state on wakeup: %ld\n", - fixnum_value(thread->state)); - } - thread->state=STATE_RUNNING; + if(thread->state!=STATE_RUNNING) { + lose("sig_stop_for_gc_handler: wrong thread state: %ld\n", + fixnum_value(thread->state)); + } + thread->state=STATE_SUSPENDED; + FSHOW_SIGNAL((stderr,"thread=%lu suspended\n",thread->os_thread)); + + sigemptyset(&ss); sigaddset(&ss,SIG_STOP_FOR_GC); + /* It is possible to get SIGCONT (and probably other + * non-blockable signals) here. */ + while (sigwaitinfo(&ss,0) != SIG_STOP_FOR_GC); + FSHOW_SIGNAL((stderr,"thread=%lu resumed\n",thread->os_thread)); + if(thread->state!=STATE_RUNNING) { + lose("sig_stop_for_gc_handler: wrong thread state on wakeup: %ld\n", + fixnum_value(thread->state)); + } - undo_fake_foreign_function_call(context); + undo_fake_foreign_function_call(context); + } } #endif @@ -693,12 +773,13 @@ gc_trigger_hit(int signal, siginfo_t *info, os_context_t *context) */ #if (defined(LISP_FEATURE_X86) || defined(LISP_FEATURE_X86_64)) -int *context_eflags_addr(os_context_t *context); +extern int *context_eflags_addr(os_context_t *context); #endif extern lispobj call_into_lisp(lispobj fun, lispobj *args, int nargs); extern void post_signal_tramp(void); -void arrange_return_to_lisp_function(os_context_t *context, lispobj function) +void +arrange_return_to_lisp_function(os_context_t *context, lispobj function) { #if !(defined(LISP_FEATURE_X86) || defined(LISP_FEATURE_X86_64)) void * fun=native_pointer(function); @@ -814,11 +895,12 @@ void arrange_return_to_lisp_function(os_context_t *context, lispobj function) #else /* this much of the calling convention is common to all non-x86 ports */ - *os_context_pc_addr(context) = (os_context_register_t)code; + *os_context_pc_addr(context) = (os_context_register_t)(unsigned long)code; *os_context_register_addr(context,reg_NARGS) = 0; - *os_context_register_addr(context,reg_LIP) = (os_context_register_t)code; + *os_context_register_addr(context,reg_LIP) = + (os_context_register_t)(unsigned long)code; *os_context_register_addr(context,reg_CFP) = - (os_context_register_t)current_control_frame_pointer; + (os_context_register_t)(unsigned long)current_control_frame_pointer; #endif #ifdef ARCH_HAS_NPC_REGISTER *os_context_npc_addr(context) = @@ -831,26 +913,16 @@ void arrange_return_to_lisp_function(os_context_t *context, lispobj function) } #ifdef LISP_FEATURE_SB_THREAD -void interrupt_thread_handler(int num, siginfo_t *info, void *v_context) + +/* FIXME: this function can go away when all lisp handlers are invoked + * via arrange_return_to_lisp_function. */ +void +interrupt_thread_handler(int num, siginfo_t *info, void *v_context) { os_context_t *context = (os_context_t*)arch_os_get_context(&v_context); - /* The order of interrupt execution is peculiar. If thread A - * interrupts thread B with I1, I2 and B for some reason recieves - * I1 when FUN2 is already on the list, then it is FUN2 that gets - * to run first. But when FUN2 is run SIG_INTERRUPT_THREAD is - * enabled again and I2 hits pretty soon in FUN2 and run - * FUN1. This is of course just one scenario, and the order of - * thread interrupt execution is undefined. */ - struct thread *th=arch_os_get_current_thread(); - struct cons *c; - if (th->state != STATE_RUNNING) - lose("interrupt_thread_handler: thread %ld in wrong state: %d\n", - th->os_thread,fixnum_value(th->state)); - get_spinlock(&th->interrupt_fun_lock,(long)th); - c=((struct cons *)native_pointer(th->interrupt_fun)); - arrange_return_to_lisp_function(context,c->car); - th->interrupt_fun=c->cdr; - release_spinlock(&th->interrupt_fun_lock); + /* let the handler enable interrupts again when it sees fit */ + sigaddset_deferrable(os_context_sigmask_addr(context)); + arrange_return_to_lisp_function(context, SymbolFunction(RUN_INTERRUPTION)); } #endif @@ -861,11 +933,13 @@ void interrupt_thread_handler(int num, siginfo_t *info, void *v_context) * that has the added benefit of automatically discriminating between * functions and variables. */ -void undefined_alien_function() { +void +undefined_alien_function() { funcall0(SymbolFunction(UNDEFINED_ALIEN_FUNCTION_ERROR)); } -boolean handle_guard_page_triggered(os_context_t *context,os_vm_address_t addr) +boolean +handle_guard_page_triggered(os_context_t *context,os_vm_address_t addr) { struct thread *th=arch_os_get_current_thread(); @@ -877,8 +951,8 @@ boolean handle_guard_page_triggered(os_context_t *context,os_vm_address_t addr) * protection so the error handler has some headroom, protect the * previous page so that we can catch returns from the guard page * and restore it. */ - protect_control_stack_guard_page(th,0); - protect_control_stack_return_guard_page(th,1); + protect_control_stack_guard_page(0); + protect_control_stack_return_guard_page(1); arrange_return_to_lisp_function (context, SymbolFunction(CONTROL_STACK_EXHAUSTED_ERROR)); @@ -890,8 +964,8 @@ boolean handle_guard_page_triggered(os_context_t *context,os_vm_address_t addr) * unprotect this one. This works even if we somehow missed * the return-guard-page, and hit it on our way to new * exhaustion instead. */ - protect_control_stack_guard_page(th,1); - protect_control_stack_return_guard_page(th,0); + protect_control_stack_guard_page(1); + protect_control_stack_return_guard_page(0); return 1; } else if (addr >= undefined_alien_address && @@ -914,16 +988,27 @@ boolean interrupt_maybe_gc(int signal, siginfo_t *info, void *void_context) { os_context_t *context=(os_context_t *) void_context; - struct thread *th=arch_os_get_current_thread(); - struct interrupt_data *data= - th ? th->interrupt_data : global_interrupt_data; - if(!data->pending_handler && !foreign_function_call_active && - gc_trigger_hit(signal, info, context)){ + if(!foreign_function_call_active && gc_trigger_hit(signal, info, context)){ + struct thread *thread=arch_os_get_current_thread(); clear_auto_gc_trigger(); - if(!maybe_defer_handler(interrupt_maybe_gc_int, - data,signal,info,void_context)) - interrupt_maybe_gc_int(signal,info,void_context); + /* Don't flood the system with interrupts if the need to gc is + * already noted. This can happen for example when SUB-GC + * allocates or after a gc triggered in a WITHOUT-GCING. */ + if (SymbolValue(GC_PENDING,thread) == NIL) { + if (SymbolValue(GC_INHIBIT,thread) == NIL) { + if (arch_pseudo_atomic_atomic(context)) { + /* set things up so that GC happens when we finish + * the PA section */ + SetSymbolValue(GC_PENDING,T,thread); + arch_set_pseudo_atomic_interrupted(context); + } else { + interrupt_maybe_gc_int(signal,info,void_context); + } + } else { + SetSymbolValue(GC_PENDING,T,thread); + } + } return 1; } return 0; @@ -936,8 +1021,10 @@ boolean interrupt_maybe_gc_int(int signal, siginfo_t *info, void *void_context) { os_context_t *context=(os_context_t *) void_context; +#ifndef LISP_FEATURE_WIN32 + struct thread *thread=arch_os_get_current_thread(); +#endif - check_blockables_blocked_or_lose(); fake_foreign_function_call(context); /* SUB-GC may return without GCing if *GC-INHIBIT* is set, in @@ -949,11 +1036,31 @@ interrupt_maybe_gc_int(int signal, siginfo_t *info, void *void_context) * and signal a storage condition from there. */ - /* restore the signal mask from the interrupted context before - * calling into Lisp */ - if (context) + /* Restore the signal mask from the interrupted context before + * calling into Lisp if interrupts are enabled. Why not always? + * + * Suppose there is a WITHOUT-INTERRUPTS block far, far out. If an + * interrupt hits while in SUB-GC, it is deferred and the + * os_context_sigmask of that interrupt is set to block further + * deferrable interrupts (until the first one is + * handled). Unfortunately, that context refers to this place and + * when we return from here the signals will not be blocked. + * + * A kludgy alternative is to propagate the sigmask change to the + * outer context. + */ +#ifndef LISP_FEATURE_WIN32 + if(SymbolValue(INTERRUPTS_ENABLED,thread)!=NIL) thread_sigmask(SIG_SETMASK, os_context_sigmask_addr(context), 0); - +#ifdef LISP_FEATURE_SB_THREAD + else { + sigset_t new; + sigemptyset(&new); + sigaddset(&new,SIG_STOP_FOR_GC); + thread_sigmask(SIG_UNBLOCK,&new,0); + } +#endif +#endif funcall0(SymbolFunction(SUB_GC)); undo_fake_foreign_function_call(context); @@ -965,6 +1072,74 @@ interrupt_maybe_gc_int(int signal, siginfo_t *info, void *void_context) * noise to install handlers */ +#ifndef LISP_FEATURE_WIN32 +/* In Linux 2.4 synchronous signals (sigtrap & co) can be delivered if + * they are blocked, in Linux 2.6 the default handler is invoked + * instead that usually coredumps. One might hastily think that adding + * SA_NODEFER helps, but until ~2.6.13 if SA_NODEFER is specified then + * the whole sa_mask is ignored and instead of not adding the signal + * in question to the mask. That means if it's not blockable the + * signal must be unblocked at the beginning of signal handlers. + */ +static volatile int sigaction_nodefer_works = -1; + +static void +sigaction_nodefer_test_handler(int signal, siginfo_t *info, void *void_context) +{ + sigset_t empty, current; + int i; + sigemptyset(&empty); + sigprocmask(SIG_BLOCK, &empty, ¤t); + for(i = 1; i < NSIG; i++) + if (sigismember(¤t, i) != ((i == SIGABRT) ? 1 : 0)) { + FSHOW_SIGNAL((stderr, "SA_NODEFER doesn't work, signal %d\n", i)); + sigaction_nodefer_works = 0; + } + if (sigaction_nodefer_works == -1) + sigaction_nodefer_works = 1; +} + +static void +see_if_sigaction_nodefer_works() +{ + struct sigaction sa, old_sa; + + sa.sa_flags = SA_SIGINFO | SA_NODEFER; + sa.sa_sigaction = sigaction_nodefer_test_handler; + sigemptyset(&sa.sa_mask); + sigaddset(&sa.sa_mask, SIGABRT); + sigaction(SIGUSR1, &sa, &old_sa); + /* Make sure no signals are blocked. */ + { + sigset_t empty; + sigemptyset(&empty); + sigprocmask(SIG_SETMASK, &empty, 0); + } + kill(getpid(), SIGUSR1); + while (sigaction_nodefer_works == -1); + sigaction(SIGUSR1, &old_sa, NULL); +} + +static void +unblock_me_trampoline(int signal, siginfo_t *info, void *void_context) +{ + sigset_t unblock; + sigemptyset(&unblock); + sigaddset(&unblock, signal); + thread_sigmask(SIG_UNBLOCK, &unblock, 0); + interrupt_handle_now_handler(signal, info, void_context); +} + +static void +low_level_unblock_me_trampoline(int signal, siginfo_t *info, void *void_context) +{ + sigset_t unblock; + sigemptyset(&unblock); + sigaddset(&unblock, signal); + thread_sigmask(SIG_UNBLOCK, &unblock, 0); + (*interrupt_low_level_handlers[signal])(signal, info, void_context); +} + void undoably_install_low_level_interrupt_handler (int signal, void handler(int, @@ -972,46 +1147,50 @@ undoably_install_low_level_interrupt_handler (int signal, void*)) { struct sigaction sa; - struct thread *th=arch_os_get_current_thread(); - struct interrupt_data *data= - th ? th->interrupt_data : global_interrupt_data; if (0 > signal || signal >= NSIG) { - lose("bad signal number %d", signal); + lose("bad signal number %d\n", signal); } - if (sigismember(&blockable_sigset,signal)) + if (ARE_SAME_HANDLER(handler, SIG_DFL)) + sa.sa_sigaction = handler; + else if (sigismember(&deferrable_sigset,signal)) sa.sa_sigaction = low_level_maybe_now_maybe_later; + else if (!sigaction_nodefer_works && + !sigismember(&blockable_sigset, signal)) + sa.sa_sigaction = low_level_unblock_me_trampoline; else sa.sa_sigaction = handler; - sigemptyset(&sa.sa_mask); - sigaddset_blockable(&sa.sa_mask); - sa.sa_flags = SA_SIGINFO | SA_RESTART; + sigcopyset(&sa.sa_mask, &blockable_sigset); + sa.sa_flags = SA_SIGINFO | SA_RESTART | + (sigaction_nodefer_works ? SA_NODEFER : 0); #ifdef LISP_FEATURE_C_STACK_IS_CONTROL_STACK if((signal==SIG_MEMORY_FAULT) +#ifdef SIG_MEMORY_FAULT2 + || (signal==SIG_MEMORY_FAULT2) +#endif #ifdef SIG_INTERRUPT_THREAD || (signal==SIG_INTERRUPT_THREAD) #endif ) - sa.sa_flags|= SA_ONSTACK; + sa.sa_flags |= SA_ONSTACK; #endif sigaction(signal, &sa, NULL); - data->interrupt_low_level_handlers[signal] = + interrupt_low_level_handlers[signal] = (ARE_SAME_HANDLER(handler, SIG_DFL) ? 0 : handler); } +#endif /* This is called from Lisp. */ unsigned long install_handler(int signal, void handler(int, siginfo_t*, void*)) { +#ifndef LISP_FEATURE_WIN32 struct sigaction sa; sigset_t old, new; union interrupt_handler oldhandler; - struct thread *th=arch_os_get_current_thread(); - struct interrupt_data *data= - th ? th->interrupt_data : global_interrupt_data; FSHOW((stderr, "/entering POSIX install_handler(%d, ..)\n", signal)); @@ -1019,50 +1198,55 @@ install_handler(int signal, void handler(int, siginfo_t*, void*)) sigaddset(&new, signal); thread_sigmask(SIG_BLOCK, &new, &old); - sigemptyset(&new); - sigaddset_blockable(&new); - - FSHOW((stderr, "/data->interrupt_low_level_handlers[signal]=%x\n", - (unsigned int)data->interrupt_low_level_handlers[signal])); - if (data->interrupt_low_level_handlers[signal]==0) { + FSHOW((stderr, "/interrupt_low_level_handlers[signal]=%x\n", + (unsigned int)interrupt_low_level_handlers[signal])); + if (interrupt_low_level_handlers[signal]==0) { if (ARE_SAME_HANDLER(handler, SIG_DFL) || - ARE_SAME_HANDLER(handler, SIG_IGN)) { + ARE_SAME_HANDLER(handler, SIG_IGN)) sa.sa_sigaction = handler; - } else if (sigismember(&new, signal)) { + else if (sigismember(&deferrable_sigset, signal)) sa.sa_sigaction = maybe_now_maybe_later; - } else { + else if (!sigaction_nodefer_works && + !sigismember(&blockable_sigset, signal)) + sa.sa_sigaction = unblock_me_trampoline; + else sa.sa_sigaction = interrupt_handle_now_handler; - } - sigemptyset(&sa.sa_mask); - sigaddset_blockable(&sa.sa_mask); - sa.sa_flags = SA_SIGINFO | SA_RESTART; + sigcopyset(&sa.sa_mask, &blockable_sigset); + sa.sa_flags = SA_SIGINFO | SA_RESTART | + (sigaction_nodefer_works ? SA_NODEFER : 0); sigaction(signal, &sa, NULL); } - oldhandler = data->interrupt_handlers[signal]; - data->interrupt_handlers[signal].c = handler; + oldhandler = interrupt_handlers[signal]; + interrupt_handlers[signal].c = handler; thread_sigmask(SIG_SETMASK, &old, 0); FSHOW((stderr, "/leaving POSIX install_handler(%d, ..)\n", signal)); return (unsigned long)oldhandler.lisp; +#else + /* Probably-wrong Win32 hack */ + return 0; +#endif } void interrupt_init() { +#ifndef LISP_FEATURE_WIN32 int i; SHOW("entering interrupt_init()"); + see_if_sigaction_nodefer_works(); + sigemptyset(&deferrable_sigset); sigemptyset(&blockable_sigset); + sigaddset_deferrable(&deferrable_sigset); sigaddset_blockable(&blockable_sigset); - global_interrupt_data=calloc(sizeof(struct interrupt_data), 1); - /* Set up high level handler information. */ for (i = 0; i < NSIG; i++) { - global_interrupt_data->interrupt_handlers[i].c = + interrupt_handlers[i].c = /* (The cast here blasts away the distinction between * SA_SIGACTION-style three-argument handlers and * signal(..)-style one-argument handlers, which is OK @@ -1072,4 +1256,5 @@ interrupt_init() } SHOW("returning from interrupt_init()"); +#endif }