X-Git-Url: http://repo.macrolet.net/gitweb/?a=blobdiff_plain;f=src%2Fruntime%2Finterrupt.c;h=3c6f716ae24f7a5b3b6f253a7525e0250ee1ff66;hb=ae09f8fd7765f6cab6ad317a13e27ff22ab0c11e;hp=88126e75d5be32b7683408a8b101457045f21b4d;hpb=d1873cc3f7a09f9891bb9c05f206af1774876c0c;p=sbcl.git diff --git a/src/runtime/interrupt.c b/src/runtime/interrupt.c index 88126e7..3c6f716 100644 --- a/src/runtime/interrupt.c +++ b/src/runtime/interrupt.c @@ -63,6 +63,7 @@ #include "alloc.h" #include "dynbind.h" #include "interr.h" +#include "pseudo-atomic.h" #include "genesis/fdefn.h" #include "genesis/simple-fun.h" #include "genesis/cons.h" @@ -74,11 +75,21 @@ static void store_signal_data_for_later (struct interrupt_data *data, siginfo_t *info, os_context_t *context); +static void +fill_current_sigmask(sigset_t *sigset) +{ + /* Get the current sigmask, by blocking the empty set. */ + sigset_t empty; + sigemptyset(&empty); + thread_sigmask(SIG_BLOCK, &empty, sigset); +} + void sigaddset_deferrable(sigset_t *s) { sigaddset(s, SIGHUP); sigaddset(s, SIGINT); + sigaddset(s, SIGTERM); sigaddset(s, SIGQUIT); sigaddset(s, SIGPIPE); sigaddset(s, SIGALRM); @@ -93,43 +104,122 @@ sigaddset_deferrable(sigset_t *s) sigaddset(s, SIGVTALRM); sigaddset(s, SIGPROF); sigaddset(s, SIGWINCH); +} -#if !((defined(LISP_FEATURE_DARWIN) || defined(LISP_FEATURE_FREEBSD)) && defined(LISP_FEATURE_SB_THREAD)) - sigaddset(s, SIGUSR1); - sigaddset(s, SIGUSR2); +void +sigdelset_deferrable(sigset_t *s) +{ + sigdelset(s, SIGHUP); + sigdelset(s, SIGINT); + sigdelset(s, SIGQUIT); + sigdelset(s, SIGPIPE); + sigdelset(s, SIGALRM); + sigdelset(s, SIGURG); + sigdelset(s, SIGTSTP); + sigdelset(s, SIGCHLD); + sigdelset(s, SIGIO); +#ifndef LISP_FEATURE_HPUX + sigdelset(s, SIGXCPU); + sigdelset(s, SIGXFSZ); #endif + sigdelset(s, SIGVTALRM); + sigdelset(s, SIGPROF); + sigdelset(s, SIGWINCH); +} + +void +sigaddset_blockable(sigset_t *sigset) +{ + sigaddset_deferrable(sigset); + sigaddset_gc(sigset); +} +void +sigaddset_gc(sigset_t *sigset) +{ #ifdef LISP_FEATURE_SB_THREAD - sigaddset(s, SIG_INTERRUPT_THREAD); + sigaddset(sigset,SIG_STOP_FOR_GC); #endif } void -sigaddset_blockable(sigset_t *s) +sigdelset_gc(sigset_t *sigset) { - sigaddset_deferrable(s); #ifdef LISP_FEATURE_SB_THREAD -#ifdef SIG_RESUME_FROM_GC - sigaddset(s, SIG_RESUME_FROM_GC); -#endif - sigaddset(s, SIG_STOP_FOR_GC); + sigdelset(sigset,SIG_STOP_FOR_GC); #endif } /* initialized in interrupt_init */ sigset_t deferrable_sigset; sigset_t blockable_sigset; +sigset_t gc_sigset; #endif +boolean +deferrables_blocked_in_sigset_p(sigset_t *sigset) +{ +#if !defined(LISP_FEATURE_WIN32) + int i; + for(i = 1; i < NSIG; i++) { + if (sigismember(&deferrable_sigset, i) && sigismember(sigset, i)) + return 1; + } +#endif + return 0; +} + +void +check_deferrables_unblocked_in_sigset_or_lose(sigset_t *sigset) +{ +#if !defined(LISP_FEATURE_WIN32) + int i; + for(i = 1; i < NSIG; i++) { + if (sigismember(&deferrable_sigset, i) && sigismember(sigset, i)) + lose("deferrable signal %d blocked\n",i); + } +#endif +} + +void +check_deferrables_blocked_in_sigset_or_lose(sigset_t *sigset) +{ +#if !defined(LISP_FEATURE_WIN32) + int i; + for(i = 1; i < NSIG; i++) { + if (sigismember(&deferrable_sigset, i) && !sigismember(sigset, i)) + lose("deferrable signal %d not blocked\n",i); + } +#endif +} + +void +check_deferrables_unblocked_or_lose(void) +{ +#if !defined(LISP_FEATURE_WIN32) + sigset_t current; + fill_current_sigmask(¤t); + check_deferrables_unblocked_in_sigset_or_lose(¤t); +#endif +} + +void +check_deferrables_blocked_or_lose(void) +{ +#if !defined(LISP_FEATURE_WIN32) + sigset_t current; + fill_current_sigmask(¤t); + check_deferrables_blocked_in_sigset_or_lose(¤t); +#endif +} + void check_blockables_blocked_or_lose(void) { #if !defined(LISP_FEATURE_WIN32) - /* Get the current sigmask, by blocking the empty set. */ - sigset_t empty,current; + sigset_t current; int i; - sigemptyset(&empty); - thread_sigmask(SIG_BLOCK, &empty, ¤t); + fill_current_sigmask(¤t); for(i = 1; i < NSIG; i++) { if (sigismember(&blockable_sigset, i) && !sigismember(¤t, i)) lose("blockable signal %d not blocked\n",i); @@ -138,16 +228,24 @@ check_blockables_blocked_or_lose(void) } void -unblock_gc_signals(void) +check_gc_signals_unblocked_in_sigset_or_lose(sigset_t *sigset) { -#ifdef LISP_FEATURE_SB_THREAD - sigset_t new; - sigemptyset(&new); -#if defined(SIG_RESUME_FROM_GC) - sigaddset(&new,SIG_RESUME_FROM_GC); +#if !defined(LISP_FEATURE_WIN32) + int i; + for(i = 1; i < NSIG; i++) { + if (sigismember(&gc_sigset, i) && sigismember(sigset, i)) + lose("gc signal %d blocked\n",i); + } #endif - sigaddset(&new,SIG_STOP_FOR_GC); - thread_sigmask(SIG_UNBLOCK,&new,0); +} + +void +check_gc_signals_unblocked_or_lose(void) +{ +#if !defined(LISP_FEATURE_WIN32) + sigset_t current; + fill_current_sigmask(¤t); + check_gc_signals_unblocked_in_sigset_or_lose(¤t); #endif } @@ -161,6 +259,118 @@ check_interrupts_enabled_or_lose(os_context_t *context) lose ("in pseudo atomic section\n"); } +/* Save sigset (or the current sigmask if 0) if there is no pending + * handler, because that means that deferabbles are already blocked. + * The purpose is to avoid losing the pending gc signal if a + * deferrable interrupt async unwinds between clearing the pseudo + * atomic and trapping to GC.*/ +void +maybe_save_gc_mask_and_block_deferrables(sigset_t *sigset) +{ + struct thread *thread = arch_os_get_current_thread(); + struct interrupt_data *data = thread->interrupt_data; + sigset_t oldset; + /* Obviously, this function is called when signals may not be + * blocked. Let's make sure we are not interrupted. */ + thread_sigmask(SIG_BLOCK, &blockable_sigset, &oldset); +#ifndef LISP_FEATURE_SB_THREAD + /* With threads a SIG_STOP_FOR_GC and a normal GC may also want to + * block. */ + if (data->gc_blocked_deferrables) + lose("gc_blocked_deferrables already true\n"); +#endif + if ((!data->pending_handler) && + (!data->gc_blocked_deferrables)) { + FSHOW_SIGNAL((stderr,"/setting gc_blocked_deferrables\n")); + data->gc_blocked_deferrables = 1; + if (sigset) { + /* This is the sigmask of some context. */ + sigcopyset(&data->pending_mask, sigset); + sigaddset_deferrable(sigset); + thread_sigmask(SIG_SETMASK,&oldset,0); + return; + } else { + /* Operating on the current sigmask. Save oldset and + * unblock gc signals. In the end, this is equivalent to + * blocking the deferrables. */ + sigcopyset(&data->pending_mask, &oldset); + unblock_gc_signals(); + return; + } + } + thread_sigmask(SIG_SETMASK,&oldset,0); +} + +/* Are we leaving WITH-GCING and already running with interrupts + * enabled, without the protection of *GC-INHIBIT* T and there is gc + * (or stop for gc) pending, but we haven't trapped yet? */ +int +in_leaving_without_gcing_race_p(struct thread *thread) +{ + return ((SymbolValue(IN_WITHOUT_GCING,thread) != NIL) && + (SymbolValue(INTERRUPTS_ENABLED,thread) != NIL) && + (SymbolValue(GC_INHIBIT,thread) == NIL) && + ((SymbolValue(GC_PENDING,thread) != NIL) +#if defined(LISP_FEATURE_SB_THREAD) + || (SymbolValue(STOP_FOR_GC_PENDING,thread) != NIL) +#endif + )); +} + +/* Check our baroque invariants. */ +void +check_interrupt_context_or_lose(os_context_t *context) +{ + struct thread *thread = arch_os_get_current_thread(); + struct interrupt_data *data = thread->interrupt_data; + int interrupt_deferred_p = (data->pending_handler != 0); + int interrupt_pending = (SymbolValue(INTERRUPT_PENDING,thread) != NIL); + sigset_t *sigset = os_context_sigmask_addr(context); + /* On PPC pseudo_atomic_interrupted is cleared when coming out of + * handle_allocation_trap. */ +#if defined(LISP_FEATURE_GENCGC) && !defined(LISP_FEATURE_PPC) + int interrupts_enabled = (SymbolValue(INTERRUPTS_ENABLED,thread) != NIL); + int gc_inhibit = (SymbolValue(GC_INHIBIT,thread) != NIL); + int gc_pending = (SymbolValue(GC_PENDING,thread) == T); + int pseudo_atomic_interrupted = get_pseudo_atomic_interrupted(thread); + int in_race_p = in_leaving_without_gcing_race_p(thread); + /* In the time window between leaving the *INTERRUPTS-ENABLED* NIL + * section and trapping, a SIG_STOP_FOR_GC would see the next + * check fail, for this reason sig_stop_for_gc handler does not + * call this function. */ + if (interrupt_deferred_p) { + if (!(!interrupts_enabled || pseudo_atomic_interrupted || in_race_p)) + lose("Stray deferred interrupt.\n"); + } + if (gc_pending) + if (!(pseudo_atomic_interrupted || gc_inhibit || in_race_p)) + lose("GC_PENDING, but why?\n"); +#if defined(LISP_FEATURE_SB_THREAD) + { + int stop_for_gc_pending = + (SymbolValue(STOP_FOR_GC_PENDING,thread) != NIL); + if (stop_for_gc_pending) + if (!(pseudo_atomic_interrupted || gc_inhibit || in_race_p)) + lose("STOP_FOR_GC_PENDING, but why?\n"); + } +#endif +#endif + if (interrupt_pending && !interrupt_deferred_p) + lose("INTERRUPT_PENDING but not pending handler.\n"); + if ((data->gc_blocked_deferrables) && interrupt_pending) + lose("gc_blocked_deferrables and interrupt pending\n."); + if (data->gc_blocked_deferrables) + check_deferrables_blocked_in_sigset_or_lose(sigset); + if (interrupt_pending || interrupt_deferred_p) + check_deferrables_blocked_in_sigset_or_lose(sigset); + else { + check_deferrables_unblocked_in_sigset_or_lose(sigset); + /* If deferrables are unblocked then we are open to signals + * that run lisp code. */ + check_gc_signals_unblocked_in_sigset_or_lose(sigset); + } +} + /* When we catch an internal error, should we pass it back to Lisp to * be handled in a high-level way? (Early in cold init, the answer is * 'no', because Lisp is still too brain-dead to handle anything. @@ -173,33 +383,73 @@ static void (*interrupt_low_level_handlers[NSIG]) (int, siginfo_t*, void*); #endif union interrupt_handler interrupt_handlers[NSIG]; -/* At the toplevel repl we routinely call this function. The signal - * mask ought to be clear anyway most of the time, but may be non-zero - * if we were interrupted e.g. while waiting for a queue. */ +void +block_blockable_signals(void) +{ +#ifndef LISP_FEATURE_WIN32 + thread_sigmask(SIG_BLOCK, &blockable_sigset, 0); +#endif +} + +void +block_deferrable_signals(void) +{ +#ifndef LISP_FEATURE_WIN32 + thread_sigmask(SIG_BLOCK, &deferrable_sigset, 0); +#endif +} void -reset_signal_mask(void) +unblock_deferrable_signals_in_sigset(sigset_t *sigset) { #ifndef LISP_FEATURE_WIN32 - sigset_t new; - sigemptyset(&new); - thread_sigmask(SIG_SETMASK,&new,0); + if (interrupt_handler_pending_p()) + lose("unblock_deferrable_signals_in_sigset: losing proposition\n"); + check_gc_signals_unblocked_in_sigset_or_lose(sigset); + sigdelset_deferrable(sigset); #endif } void -block_blockable_signals(void) +unblock_deferrable_signals(void) { #ifndef LISP_FEATURE_WIN32 - thread_sigmask(SIG_BLOCK, &blockable_sigset, 0); + if (interrupt_handler_pending_p()) + lose("unblock_deferrable_signals: losing proposition\n"); + check_gc_signals_unblocked_or_lose(); + thread_sigmask(SIG_UNBLOCK, &deferrable_sigset, 0); #endif } void -block_deferrable_signals(void) +unblock_gc_signals(void) +{ +#if defined(LISP_FEATURE_SB_THREAD) && !defined(LISP_FEATURE_WIN32) + thread_sigmask(SIG_UNBLOCK,&gc_sigset,0); +#endif +} + +void +unblock_signals_in_context_and_maybe_warn(os_context_t *context) { #ifndef LISP_FEATURE_WIN32 - thread_sigmask(SIG_BLOCK, &deferrable_sigset, 0); + int i, oops=0; + sigset_t *sigset=os_context_sigmask_addr(context); + for(i = 1; i < NSIG; i++) { + if (sigismember(&gc_sigset, i) && sigismember(sigset, i)) { + if (!oops) { + fprintf(stderr, +"Enabling blocked gc signals to allow returning to Lisp without risking\n\ +gc deadlocks. Since GC signals are only blocked in signal handlers when \n\ +they are not safe to interrupt at all, this is a pretty severe occurrence.\n"); + } + oops=1; + } + } + sigdelset_gc(sigset); + if (!interrupt_handler_pending_p()) { + unblock_deferrable_signals_in_sigset(sigset); + } #endif } @@ -367,12 +617,23 @@ interrupt_internal_error(os_context_t *context, boolean continuable) /* Allocate the SAP object while the interrupts are still * disabled. */ + unblock_gc_signals(); context_sap = alloc_sap(context); #ifndef LISP_FEATURE_WIN32 thread_sigmask(SIG_SETMASK, os_context_sigmask_addr(context), 0); #endif +#if defined(LISP_FEATURE_LINUX) && defined(LISP_FEATURE_MIPS) + /* Workaround for blocked SIGTRAP. */ + { + sigset_t newset; + sigemptyset(&newset); + sigaddset(&newset, SIGTRAP); + thread_sigmask(SIG_UNBLOCK, &newset, 0); + } +#endif + SHOW("in interrupt_internal_error"); #ifdef QSHOW /* Display some rudimentary debugging information about the @@ -388,6 +649,14 @@ interrupt_internal_error(os_context_t *context, boolean continuable) arch_skip_instruction(context); } +boolean +interrupt_handler_pending_p(void) +{ + struct thread *thread = arch_os_get_current_thread(); + struct interrupt_data *data = thread->interrupt_data; + return (data->pending_handler != 0); +} + void interrupt_handle_pending(os_context_t *context) { @@ -404,78 +673,134 @@ interrupt_handle_pending(os_context_t *context) /* Win32 only needs to handle the GC cases (for now?) */ - struct thread *thread; + struct thread *thread = arch_os_get_current_thread(); + struct interrupt_data *data = thread->interrupt_data; - /* Punt if in PA section, marking it as interrupted. This can - * happenat least if we pick up a GC request while in a - * WITHOUT-GCING with an outer PA -- it is not immediately clear - * to me that this should/could ever happen, but better safe then - * sorry. --NS 2007-05-15 */ if (arch_pseudo_atomic_atomic(context)) { - arch_set_pseudo_atomic_interrupted(context); - return; + lose("Handling pending interrupt in pseduo atomic."); } - thread = arch_os_get_current_thread(); - FSHOW_SIGNAL((stderr, "/entering interrupt_handle_pending\n")); check_blockables_blocked_or_lose(); - /* 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); + /* If GC/SIG_STOP_FOR_GC struck during PA and there was no pending + * handler, then the pending mask was saved and + * gc_blocked_deferrables set. Hence, there can be no pending + * handler and it's safe to restore the pending mask. + * + * Note, that if gc_blocked_deferrables is false we may still have + * to GC. In this case, we are coming out of a WITHOUT-GCING or a + * pseudo atomic was interrupt be a deferrable first. */ + if (data->gc_blocked_deferrables) { + if (data->pending_handler) + lose("GC blocked deferrables but still got a pending handler."); + if (SymbolValue(GC_INHIBIT,thread)!=NIL) + lose("GC blocked deferrables while GC is inhibited."); + /* 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); + data->gc_blocked_deferrables = 0; + } if (SymbolValue(GC_INHIBIT,thread)==NIL) { + void *original_pending_handler = data->pending_handler; + #ifdef LISP_FEATURE_SB_THREAD if (SymbolValue(STOP_FOR_GC_PENDING,thread) != NIL) { /* STOP_FOR_GC_PENDING and GC_PENDING are cleared by * the signal handler if it actually stops us. */ + arch_clear_pseudo_atomic_interrupted(context); sig_stop_for_gc_handler(SIG_STOP_FOR_GC,NULL,context); } else #endif - if (SymbolValue(GC_PENDING,thread) != NIL) { + /* Test for T and not for != NIL since the value :IN-PROGRESS + * is used in SUB-GC as part of the mechanism to supress + * recursive gcs.*/ + if (SymbolValue(GC_PENDING,thread) == T) { + + /* Two reasons for doing this. First, if there is a + * pending handler we don't want to run. Second, we are + * going to clear pseudo atomic interrupted to avoid + * spurious trapping on every allocation in SUB_GC and + * having a pending handler with interrupts enabled and + * without pseudo atomic interrupted breaks an + * invariant. */ + if (data->pending_handler) { + bind_variable(ALLOW_WITH_INTERRUPTS, NIL, thread); + bind_variable(INTERRUPTS_ENABLED, NIL, thread); + } + + arch_clear_pseudo_atomic_interrupted(context); + /* 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. */ - maybe_gc(context); + * that will clear it. + * + * If there is a pending handler or gc was triggerred in a + * signal handler then maybe_gc won't run POST_GC and will + * return normally. */ + if (!maybe_gc(context)) + lose("GC not inhibited but maybe_gc did not GC."); + + if (data->pending_handler) { + unbind(thread); + unbind(thread); + } + } else if (SymbolValue(GC_PENDING,thread) != NIL) { + /* It's not NIL or T so GC_PENDING is :IN-PROGRESS. If + * GC-PENDING is not NIL then we cannot trap on pseudo + * atomic due to GC (see if(GC_PENDING) logic in + * cheneygc.c an gengcgc.c), plus there is a outer + * WITHOUT-INTERRUPTS SUB_GC, so how did we end up + * here? */ + lose("Trapping to run pending handler while GC in progress."); } + check_blockables_blocked_or_lose(); + + /* No GC shall be lost. If SUB_GC triggers another GC then + * that should be handled on the spot. */ + if (SymbolValue(GC_PENDING,thread) != NIL) + lose("GC_PENDING after doing gc."); +#ifdef LISP_FEATURE_SB_THREAD + if (SymbolValue(STOP_FOR_GC_PENDING,thread) != NIL) + lose("STOP_FOR_GC_PENDING after doing gc."); +#endif + /* Check two things. First, that gc does not clobber a handler + * that's already pending. Second, that there is no interrupt + * lossage: if original_pending_handler was NULL then even if + * an interrupt arrived during GC (POST-GC, really) it was + * handled. */ + if (original_pending_handler != data->pending_handler) + lose("pending handler changed in gc: %x -> %d.", + original_pending_handler, data->pending_handler); } #ifndef LISP_FEATURE_WIN32 - /* we may be here only to do the gc stuff, if interrupts are - * enabled run the pending handler */ - if (SymbolValue(INTERRUPTS_ENABLED,thread) != NIL) { - struct interrupt_data *data = thread->interrupt_data; - - /* 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 pseudo-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); - - /* 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); - } + /* There may be no pending handler, because it was only a gc that + * had to be executed or because Lisp is a bit too eager to call + * DO-PENDING-INTERRUPT. */ + if ((SymbolValue(INTERRUPTS_ENABLED,thread) != NIL) && + (data->pending_handler)) { + /* No matter how we ended up here, clear both + * INTERRUPT_PENDING and pseudo atomic interrupted. It's safe + * because we checked above that there is no GC pending. */ + SetSymbolValue(INTERRUPT_PENDING, NIL, thread); + arch_clear_pseudo_atomic_interrupted(context); + /* Restore the sigmask in the context. */ + sigcopyset(os_context_sigmask_addr(context), &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); } + /* It is possible that the end of this function was reached + * without never actually doing anything, the tests in Lisp for + * when to call receive-pending-interrupt are not exact. */ + FSHOW_SIGNAL((stderr, "/exiting interrupt_handle_pending\n")); #endif } @@ -557,21 +882,12 @@ interrupt_handle_now(int signal, siginfo_t *info, os_context_t *context) * 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); + lispobj info_sap, context_sap; /* 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); -#ifdef SIG_RESUME_FROM_GC - sigaddset(&unblock, SIG_RESUME_FROM_GC); -#endif - thread_sigmask(SIG_UNBLOCK, &unblock, 0); - } -#endif + unblock_gc_signals(); + context_sap = alloc_sap(context); + info_sap = alloc_sap(info); FSHOW_SIGNAL((stderr,"/calling Lisp-level handler\n")); @@ -580,6 +896,7 @@ interrupt_handle_now(int signal, siginfo_t *info, os_context_t *context) info_sap, context_sap); } else { + /* This cannot happen in sane circumstances. */ FSHOW_SIGNAL((stderr,"/calling C-level handler\n")); @@ -617,6 +934,7 @@ run_deferred_handler(struct interrupt_data *data, void *v_context) void (*pending_handler) (int, siginfo_t*, void*)=data->pending_handler; data->pending_handler=0; + FSHOW_SIGNAL((stderr, "/running deferred handler %p\n", pending_handler)); (*pending_handler)(data->pending_signal,&(data->pending_info), v_context); } @@ -631,16 +949,28 @@ maybe_defer_handler(void *handler, struct interrupt_data *data, if (SymbolValue(INTERRUPT_PENDING,thread) != NIL) lose("interrupt already pending\n"); + if (thread->interrupt_data->pending_handler) + lose("there is a pending handler already (PA)\n"); + if (data->gc_blocked_deferrables) + lose("maybe_defer_handler: gc_blocked_deferrables true\n"); + check_interrupt_context_or_lose(context); /* 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. + * + * Also, if in_leaving_without_gcing_race_p then + * interrupt_handle_pending is going to be called soon, so + * stashing the signal away is safe. */ - if (SymbolValue(INTERRUPTS_ENABLED,thread) == NIL) { + if ((SymbolValue(INTERRUPTS_ENABLED,thread) == NIL) || + in_leaving_without_gcing_race_p(thread)) { store_signal_data_for_later(data,handler,signal,info,context); SetSymbolValue(INTERRUPT_PENDING, T,thread); FSHOW_SIGNAL((stderr, - "/maybe_defer_handler(%x,%d): deferred\n", - (unsigned int)handler,signal)); + "/maybe_defer_handler(%x,%d): deferred (RACE=%d)\n", + (unsigned int)handler,signal, + in_leaving_without_gcing_race_p(thread))); + check_interrupt_context_or_lose(context); return 1; } /* a slightly confusing test. arch_pseudo_atomic_atomic() doesn't @@ -652,6 +982,7 @@ maybe_defer_handler(void *handler, struct interrupt_data *data, FSHOW_SIGNAL((stderr, "/maybe_defer_handler(%x,%d): deferred(PA)\n", (unsigned int)handler,signal)); + check_interrupt_context_or_lose(context); return 1; } FSHOW_SIGNAL((stderr, @@ -678,15 +1009,16 @@ store_signal_data_for_later (struct interrupt_data *data, void *handler, FSHOW_SIGNAL((stderr, "/store_signal_data_for_later: signal: %d\n", signal)); - if(context) { - /* the signal mask in the context (from before we were - * interrupted) is copied to be restored when - * run_deferred_handler happens. Then the usually-blocked - * 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_deferrable(os_context_sigmask_addr(context)); - } + if(!context) + lose("Null context"); + + /* the signal mask in the context (from before we were + * interrupted) is copied to be restored when run_deferred_handler + * happens. Then the usually-blocked 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_deferrable(os_context_sigmask_addr(context)); } static void @@ -734,6 +1066,7 @@ low_level_maybe_now_maybe_later(int signal, siginfo_t *info, void *void_context) #ifdef LISP_FEATURE_SB_THREAD +/* This function must not cons, because that may trigger a GC. */ void sig_stop_for_gc_handler(int signal, siginfo_t *info, void *void_context) { @@ -742,18 +1075,23 @@ sig_stop_for_gc_handler(int signal, siginfo_t *info, void *void_context) struct thread *thread=arch_os_get_current_thread(); sigset_t ss; - if (arch_pseudo_atomic_atomic(context)) { + /* Test for GC_INHIBIT _first_, else we'd trap on every single + * pseudo atomic until gc is finally allowed. */ + if (SymbolValue(GC_INHIBIT,thread) != NIL) { SetSymbolValue(STOP_FOR_GC_PENDING,T,thread); - arch_set_pseudo_atomic_interrupted(context); - FSHOW_SIGNAL((stderr, "sig_stop_for_gc deferred (PA)\n")); + FSHOW_SIGNAL((stderr, "sig_stop_for_gc deferred (*GC-INHIBIT*)\n")); return; - } - else if (SymbolValue(GC_INHIBIT,thread) != NIL) { + } else if (arch_pseudo_atomic_atomic(context)) { SetSymbolValue(STOP_FOR_GC_PENDING,T,thread); - FSHOW_SIGNAL((stderr, "sig_stop_for_gc deferred (*GC-INHIBIT*)\n")); + arch_set_pseudo_atomic_interrupted(context); + maybe_save_gc_mask_and_block_deferrables + (os_context_sigmask_addr(context)); + FSHOW_SIGNAL((stderr,"sig_stop_for_gc deferred (PA)\n")); return; } + FSHOW_SIGNAL((stderr, "/sig_stop_for_gc_handler\n")); + /* Not PA and GC not inhibited -- we can stop now. */ /* need the context stored so it can have registers scavenged */ @@ -767,41 +1105,25 @@ sig_stop_for_gc_handler(int signal, siginfo_t *info, void *void_context) SetSymbolValue(GC_PENDING,NIL,thread); SetSymbolValue(STOP_FOR_GC_PENDING,NIL,thread); - if(thread->state!=STATE_RUNNING) { + if(thread_state(thread)!=STATE_RUNNING) { lose("sig_stop_for_gc_handler: wrong thread state: %ld\n", fixnum_value(thread->state)); } - thread->state=STATE_SUSPENDED; + set_thread_state(thread,STATE_SUSPENDED); FSHOW_SIGNAL((stderr,"suspended\n")); - sigemptyset(&ss); -#if defined(SIG_RESUME_FROM_GC) - sigaddset(&ss,SIG_RESUME_FROM_GC); -#else - sigaddset(&ss,SIG_STOP_FOR_GC); -#endif - - /* It is possible to get SIGCONT (and probably other non-blockable - * signals) here. */ -#ifdef SIG_RESUME_FROM_GC - { - int sigret; - do { sigwait(&ss, &sigret); } - while (sigret != SIG_RESUME_FROM_GC); - } -#else - while (sigwaitinfo(&ss,0) != SIG_STOP_FOR_GC); -#endif - + wait_for_thread_state_change(thread, STATE_SUSPENDED); FSHOW_SIGNAL((stderr,"resumed\n")); - if(thread->state!=STATE_RUNNING) { + + if(thread_state(thread)!=STATE_RUNNING) { lose("sig_stop_for_gc_handler: wrong thread state on wakeup: %ld\n", - fixnum_value(thread->state)); + fixnum_value(thread_state(thread))); } undo_fake_foreign_function_call(context); } + #endif void @@ -837,6 +1159,8 @@ extern void call_into_lisp_tramp(void); void arrange_return_to_lisp_function(os_context_t *context, lispobj function) { + check_gc_signals_unblocked_in_sigset_or_lose + (os_context_sigmask_addr(context)); #if !(defined(LISP_FEATURE_X86) || defined(LISP_FEATURE_X86_64)) void * fun=native_pointer(function); void *code = &(((struct simple_fun *) fun)->code); @@ -1008,26 +1332,6 @@ arrange_return_to_lisp_function(os_context_t *context, lispobj function) (long)function)); } -#ifdef LISP_FEATURE_SB_THREAD - -/* 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); - - FSHOW_SIGNAL((stderr,"/interrupt_thread_handler\n")); - check_blockables_blocked_or_lose(); - - /* let the handler enable interrupts again when it sees fit */ - sigaddset_deferrable(os_context_sigmask_addr(context)); - arrange_return_to_lisp_function(context, - StaticSymbolFunction(RUN_INTERRUPTION)); -} - -#endif - /* KLUDGE: Theoretically the approach we use for undefined alien * variables should work for functions as well, but on PPC/Darwin * we get bus error at bogus addresses instead, hence this workaround, @@ -1057,6 +1361,11 @@ handle_guard_page_triggered(os_context_t *context,os_vm_address_t addr) protect_control_stack_guard_page(0); protect_control_stack_return_guard_page(1); +#ifdef LISP_FEATURE_C_STACK_IS_CONTROL_STACK + /* For the unfortunate case, when the control stack is + * exhausted in a signal handler. */ + unblock_signals_in_context_and_maybe_warn(context); +#endif arrange_return_to_lisp_function (context, StaticSymbolFunction(CONTROL_STACK_EXHAUSTED_ERROR)); return 1; @@ -1067,6 +1376,7 @@ 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. */ + fprintf(stderr, "INFO: Control stack guard page reprotected\n"); protect_control_stack_guard_page(1); protect_control_stack_return_guard_page(0); return 1; @@ -1202,11 +1512,7 @@ undoably_install_low_level_interrupt_handler (int signal, 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_INTERRUPT_THREAD - || (signal==SIG_INTERRUPT_THREAD) -#endif - ) + if((signal==SIG_MEMORY_FAULT)) sa.sa_flags |= SA_ONSTACK; #endif @@ -1265,6 +1571,14 @@ install_handler(int signal, void handler(int, siginfo_t*, void*)) #endif } +/* This must not go through lisp as it's allowed anytime, even when on + * the altstack. */ +void +sigabrt_handler(int signal, siginfo_t *info, void *void_context) +{ + lose("SIGABRT received.\n"); +} + void interrupt_init(void) { @@ -1274,8 +1588,10 @@ interrupt_init(void) see_if_sigaction_nodefer_works(); sigemptyset(&deferrable_sigset); sigemptyset(&blockable_sigset); + sigemptyset(&gc_sigset); sigaddset_deferrable(&deferrable_sigset); sigaddset_blockable(&blockable_sigset); + sigaddset_gc(&gc_sigset); /* Set up high level handler information. */ for (i = 0; i < NSIG; i++) { @@ -1287,7 +1603,7 @@ interrupt_init(void) * 3-argument form is expected.) */ (void (*)(int, siginfo_t*, void*))SIG_DFL; } - + undoably_install_low_level_interrupt_handler(SIGABRT, sigabrt_handler); SHOW("returning from interrupt_init()"); #endif } @@ -1311,6 +1627,7 @@ lisp_memory_fault_error(os_context_t *context, os_vm_address_t addr) current_memory_fault_address = addr; /* To allow debugging memory faults in signal handlers and such. */ corruption_warning_and_maybe_lose("Memory fault"); + unblock_signals_in_context_and_maybe_warn(context); arrange_return_to_lisp_function(context, StaticSymbolFunction(MEMORY_FAULT_ERROR)); } @@ -1321,6 +1638,7 @@ unhandled_trap_error(os_context_t *context) { lispobj context_sap; fake_foreign_function_call(context); + unblock_gc_signals(); context_sap = alloc_sap(context); #ifndef LISP_FEATURE_WIN32 thread_sigmask(SIG_SETMASK, os_context_sigmask_addr(context), 0); @@ -1370,4 +1688,3 @@ handle_trap(os_context_t *context, int trap) unhandled_trap_error(context); } } -