X-Git-Url: http://repo.macrolet.net/gitweb/?a=blobdiff_plain;f=src%2Fruntime%2Finterrupt.c;h=882e2bb322e64bda821c0c90dadee262911685f5;hb=bf40ae88bc289fd765a33861cc4bc0853ed483ba;hp=159a9aeb81626dc2236399e0d692fb0f35c340ae;hpb=68fd2d2dd6f265669a8957accd8a33e62786a97e;p=sbcl.git diff --git a/src/runtime/interrupt.c b/src/runtime/interrupt.c index 159a9ae..882e2bb 100644 --- a/src/runtime/interrupt.c +++ b/src/runtime/interrupt.c @@ -13,29 +13,269 @@ * files for more information. */ + +/* As far as I can tell, what's going on here is: + * + * In the case of most signals, when Lisp asks us to handle the + * signal, the outermost handler (the one actually passed to UNIX) is + * either interrupt_handle_now(..) or maybe_now_maybe_later(..). + * In that case, the Lisp-level handler is stored in interrupt_handlers[..] + * and interrupt_low_level_handlers[..] is cleared. + * + * However, some signals need special handling, e.g. + * + * o the SIGSEGV (for e.g. Linux) or SIGBUS (for e.g. FreeBSD) used by the + * garbage collector to detect violations of write protection, + * because some cases of such signals (e.g. GC-related violations of + * write protection) are handled at C level and never passed on to + * Lisp. For such signals, we still store any Lisp-level handler + * in interrupt_handlers[..], but for the outermost handle we use + * the value from interrupt_low_level_handlers[..], instead of the + * ordinary interrupt_handle_now(..) or interrupt_handle_later(..). + * + * o the SIGTRAP (Linux/Alpha) which Lisp code uses to handle breakpoints, + * pseudo-atomic sections, and some classes of error (e.g. "function + * not defined"). This never goes anywhere near the Lisp handlers at all. + * See runtime/alpha-arch.c and code/signal.lisp + * + * - WHN 20000728, dan 20010128 */ + +#include "sbcl.h" + #include #include - +#include #include +#include +#ifndef LISP_FEATURE_WIN32 +#include +#endif +#include #include "runtime.h" #include "arch.h" -#include "sbcl.h" #include "os.h" #include "interrupt.h" #include "globals.h" #include "lispregs.h" #include "validate.h" -#include "monitor.h" +#include "interr.h" #include "gc.h" #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" + +/* 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. + * After sufficient initialization has been completed, the answer + * becomes 'yes'.) */ +boolean internal_errors_enabled = 0; + +#ifndef LISP_FEATURE_WIN32 +static +void (*interrupt_low_level_handlers[NSIG]) (int, siginfo_t*, os_context_t*); +#endif +union interrupt_handler interrupt_handlers[NSIG]; + +/* Under Linux on some architectures, we appear to have to restore the + * FPU control word from the context, as after the signal is delivered + * we appear to have a null FPU control word. */ +#if defined(RESTORE_FP_CONTROL_FROM_CONTEXT) +#define RESTORE_FP_CONTROL_WORD(context,void_context) \ + os_context_t *context = arch_os_get_context(&void_context); \ + os_restore_fp_control(context); +#else +#define RESTORE_FP_CONTROL_WORD(context,void_context) \ + os_context_t *context = arch_os_get_context(&void_context); +#endif + +/* Foreign code may want to start some threads on its own. + * Non-targetted, truly asynchronous signals can be delivered to + * basically any thread, but invoking Lisp handlers in such foregign + * threads is really bad, so let's resignal it. + * + * This should at least bring attention to the problem, but it cannot + * work for SIGSEGV and similar. It is good enough for timers, and + * maybe all deferrables. */ + +#if defined(LISP_FEATURE_SB_THREAD) && !defined(LISP_FEATURE_WIN32) +static void +add_handled_signals(sigset_t *sigset) +{ + int i; + for(i = 1; i < NSIG; i++) { + if (!(ARE_SAME_HANDLER(interrupt_low_level_handlers[i], SIG_DFL)) || + !(ARE_SAME_HANDLER(interrupt_handlers[i].c, SIG_DFL))) { + sigaddset(sigset, i); + } + } +} + +void block_signals(sigset_t *what, sigset_t *where, sigset_t *old); +#endif + +static boolean +maybe_resignal_to_lisp_thread(int signal, os_context_t *context) +{ +#if defined(LISP_FEATURE_SB_THREAD) && !defined(LISP_FEATURE_WIN32) + if (!pthread_getspecific(lisp_thread)) { + if (!(sigismember(&deferrable_sigset,signal))) { + corruption_warning_and_maybe_lose + ("Received signal %d in non-lisp thread %lu, resignalling to a lisp thread.", + signal, + pthread_self()); + } + { + sigset_t sigset; + sigemptyset(&sigset); + add_handled_signals(&sigset); + block_signals(&sigset, 0, 0); + block_signals(&sigset, os_context_sigmask_addr(context), 0); + kill(getpid(), signal); + } + return 1; + } else +#endif + return 0; +} + +/* These are to be used in signal handlers. Currently all handlers are + * called from one of: + * + * interrupt_handle_now_handler + * maybe_now_maybe_later + * unblock_me_trampoline + * low_level_handle_now_handler + * low_level_maybe_now_maybe_later + * low_level_unblock_me_trampoline + * + * This gives us a single point of control (or six) over errno, fp + * control word, and fixing up signal context on sparc. + * + * The SPARC/Linux platform doesn't quite do signals the way we want + * them done. The third argument in the handler isn't filled in by the + * kernel properly, so we fix it up ourselves in the + * arch_os_get_context(..) function. -- CSR, 2002-07-23 + */ +#define SAVE_ERRNO(signal,context,void_context) \ + { \ + int _saved_errno = errno; \ + RESTORE_FP_CONTROL_WORD(context,void_context); \ + if (!maybe_resignal_to_lisp_thread(signal, context)) \ + { + +#define RESTORE_ERRNO \ + } \ + errno = _saved_errno; \ + } + +static void run_deferred_handler(struct interrupt_data *data, + os_context_t *context); +#if !defined(LISP_FEATURE_WIN32) || defined(LISP_FEATURE_SB_THREAD) +static void store_signal_data_for_later (struct interrupt_data *data, + void *handler, int signal, + siginfo_t *info, + os_context_t *context); + + +/* Generic signal related utilities. */ + +void +get_current_sigmask(sigset_t *sigset) +{ + /* Get the current sigmask, by blocking the empty set. */ + thread_sigmask(SIG_BLOCK, 0, sigset); +} + +void +block_signals(sigset_t *what, sigset_t *where, sigset_t *old) +{ + if (where) { + int i; + if (old) + sigcopyset(old, where); + for(i = 1; i < NSIG; i++) { + if (sigismember(what, i)) + sigaddset(where, i); + } + } else { + thread_sigmask(SIG_BLOCK, what, old); + } +} + +void +unblock_signals(sigset_t *what, sigset_t *where, sigset_t *old) +{ + if (where) { + int i; + if (old) + sigcopyset(old, where); + for(i = 1; i < NSIG; i++) { + if (sigismember(what, i)) + sigdelset(where, i); + } + } else { + thread_sigmask(SIG_UNBLOCK, what, old); + } +} + +static void +print_sigset(sigset_t *sigset) +{ + int i; + for(i = 1; i < NSIG; i++) { + if (sigismember(sigset, i)) + fprintf(stderr, "Signal %d masked\n", i); + } +} -void sigaddset_blockable(sigset_t *s) +/* Return 1 is all signals is sigset2 are masked in sigset, return 0 + * if all re unmasked else die. Passing NULL for sigset is a shorthand + * for the current sigmask. */ +boolean +all_signals_blocked_p(sigset_t *sigset, sigset_t *sigset2, + const char *name) +{ +#if !defined(LISP_FEATURE_WIN32) || defined(LISP_FEATURE_SB_THREAD) + int i; + boolean has_blocked = 0, has_unblocked = 0; + sigset_t current; + if (sigset == 0) { + get_current_sigmask(¤t); + sigset = ¤t; + } + for(i = 1; i < NSIG; i++) { + if (sigismember(sigset2, i)) { + if (sigismember(sigset, i)) + has_blocked = 1; + else + has_unblocked = 1; + } + } + if (has_blocked && has_unblocked) { + print_sigset(sigset); + lose("some %s signals blocked, some unblocked\n", name); + } + if (has_blocked) + return 1; + else + return 0; +#endif +} + + +/* Deferrables, blockables, gc signals. */ + +void +sigaddset_deferrable(sigset_t *s) { sigaddset(s, SIGHUP); sigaddset(s, SIGINT); + sigaddset(s, SIGTERM); sigaddset(s, SIGQUIT); sigaddset(s, SIGPIPE); sigaddset(s, SIGALRM); @@ -43,669 +283,1875 @@ void sigaddset_blockable(sigset_t *s) sigaddset(s, SIGTSTP); sigaddset(s, SIGCHLD); sigaddset(s, SIGIO); +#ifndef LISP_FEATURE_HPUX sigaddset(s, SIGXCPU); sigaddset(s, SIGXFSZ); +#endif sigaddset(s, SIGVTALRM); sigaddset(s, SIGPROF); sigaddset(s, SIGWINCH); - sigaddset(s, SIGUSR1); - sigaddset(s, SIGUSR2); } -/* 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. - * After sufficient initialization has been completed, the answer - * becomes 'yes'.) */ -boolean internal_errors_enabled = 0; +void +sigaddset_blockable(sigset_t *sigset) +{ + sigaddset_deferrable(sigset); + sigaddset_gc(sigset); +} -os_context_t *lisp_interrupt_contexts[MAX_INTERRUPTS]; +void +sigaddset_gc(sigset_t *sigset) +{ +#ifdef THREADS_USING_GCSIGNAL + sigaddset(sigset,SIG_STOP_FOR_GC); +#endif +} -/* As far as I can tell, what's going on here is: - * - * In the case of most signals, when Lisp asks us to handle the - * signal, the outermost handler (the one actually passed to UNIX) is - * either interrupt_handle_now(..) or interrupt_handle_later(..). - * In that case, the Lisp-level handler is stored in interrupt_handlers[..] - * and interrupt_low_level_handlers[..] is cleared. - * - * However, some signals need special handling, e.g. - * - * o the SIGSEGV (for e.g. Linux) or SIGBUS (for e.g. FreeBSD) used by the - * garbage collector to detect violations of write protection, - * because some cases of such signals (e.g. GC-related violations of - * write protection) are handled at C level and never passed on to - * Lisp. For such signals, we still store any Lisp-level handler - * in interrupt_handlers[..], but for the outermost handle we use - * the value from interrupt_low_level_handlers[..], instead of the - * ordinary interrupt_handle_now(..) or interrupt_handle_later(..). - * - * o the SIGTRAP (Linux/Alpha) which Lisp code uses to handle breakpoints, - * pseudo-atomic sections, and some classes of error (e.g. "function - * not defined"). This never goes anywhere near the Lisp handlers at all. - * See runtime/alpha-arch.c and code/signal.lisp - * - * - WHN 20000728, dan 20010128 */ +/* initialized in interrupt_init */ +sigset_t deferrable_sigset; +sigset_t blockable_sigset; +sigset_t gc_sigset; +#endif -void (*interrupt_low_level_handlers[NSIG]) (int, siginfo_t*, void*) = {0}; -union interrupt_handler interrupt_handlers[NSIG]; +#if !defined(LISP_FEATURE_WIN32) || defined(LISP_FEATURE_SB_THREAD) +boolean +deferrables_blocked_p(sigset_t *sigset) +{ + return all_signals_blocked_p(sigset, &deferrable_sigset, "deferrable"); +} +#endif + +void +check_deferrables_unblocked_or_lose(sigset_t *sigset) +{ +#if !defined(LISP_FEATURE_WIN32) || defined(LISP_FEATURE_SB_THREAD) + if (deferrables_blocked_p(sigset)) + lose("deferrables blocked\n"); +#endif +} + +void +check_deferrables_blocked_or_lose(sigset_t *sigset) +{ +#if !defined(LISP_FEATURE_WIN32) || defined(LISP_FEATURE_SB_THREAD) + if (!deferrables_blocked_p(sigset)) + lose("deferrables unblocked\n"); +#endif +} + +#if !defined(LISP_FEATURE_WIN32) || defined(LISP_FEATURE_SB_THREAD) +boolean +blockables_blocked_p(sigset_t *sigset) +{ + return all_signals_blocked_p(sigset, &blockable_sigset, "blockable"); +} +#endif + +void +check_blockables_unblocked_or_lose(sigset_t *sigset) +{ +#if !defined(LISP_FEATURE_WIN32) || defined(LISP_FEATURE_SB_THREAD) + if (blockables_blocked_p(sigset)) + lose("blockables blocked\n"); +#endif +} + +void +check_blockables_blocked_or_lose(sigset_t *sigset) +{ +#if !defined(LISP_FEATURE_WIN32) + /* On Windows, there are no actual signals, but since the win32 port + * tracks the sigmask and checks it explicitly, some functions are + * still required to keep the mask set up properly. (After all, the + * goal of the sigmask emulation is to not have to change all the + * call sites in the first place.) + * + * However, this does not hold for all signals equally: While + * deferrables matter ("is interrupt-thread okay?"), it is not worth + * having to set up blockables properly (which include the + * non-existing GC signals). + * + * Yet, as the original comment explains it: + * Adjusting FREE-INTERRUPT-CONTEXT-INDEX* and other aspecs of + * fake_foreign_function_call machinery are sometimes useful here[...]. + * + * So we merely skip this assertion. + * -- DFL, trying to expand on a comment by AK. + */ + if (!blockables_blocked_p(sigset)) + lose("blockables unblocked\n"); +#endif +} + +#ifndef LISP_FEATURE_SB_SAFEPOINT +#if !defined(LISP_FEATURE_WIN32) +boolean +gc_signals_blocked_p(sigset_t *sigset) +{ + return all_signals_blocked_p(sigset, &gc_sigset, "gc"); +} +#endif + +void +check_gc_signals_unblocked_or_lose(sigset_t *sigset) +{ +#if !defined(LISP_FEATURE_WIN32) + if (gc_signals_blocked_p(sigset)) + lose("gc signals blocked\n"); +#endif +} + +void +check_gc_signals_blocked_or_lose(sigset_t *sigset) +{ +#if !defined(LISP_FEATURE_WIN32) + if (!gc_signals_blocked_p(sigset)) + lose("gc signals unblocked\n"); +#endif +} +#endif + +void +block_deferrable_signals(sigset_t *where, sigset_t *old) +{ +#if !defined(LISP_FEATURE_WIN32) || defined(LISP_FEATURE_SB_THREAD) + block_signals(&deferrable_sigset, where, old); +#endif +} + +void +block_blockable_signals(sigset_t *where, sigset_t *old) +{ +#if !defined(LISP_FEATURE_WIN32) || defined(LISP_FEATURE_SB_THREAD) + block_signals(&blockable_sigset, where, old); +#endif +} + +#ifndef LISP_FEATURE_SB_SAFEPOINT +void +block_gc_signals(sigset_t *where, sigset_t *old) +{ +#if !defined(LISP_FEATURE_WIN32) || defined(LISP_FEATURE_SB_THREAD) + block_signals(&gc_sigset, where, old); +#endif +} +#endif + +void +unblock_deferrable_signals(sigset_t *where, sigset_t *old) +{ +#if !defined(LISP_FEATURE_WIN32) || defined(LISP_FEATURE_SB_THREAD) + if (interrupt_handler_pending_p()) + lose("unblock_deferrable_signals: losing proposition\n"); +#ifndef LISP_FEATURE_SB_SAFEPOINT + check_gc_signals_unblocked_or_lose(where); +#endif + unblock_signals(&deferrable_sigset, where, old); +#endif +} + +void +unblock_blockable_signals(sigset_t *where, sigset_t *old) +{ +#if !defined(LISP_FEATURE_WIN32) || defined(LISP_FEATURE_SB_THREAD) + unblock_signals(&blockable_sigset, where, old); +#endif +} + +#ifndef LISP_FEATURE_SB_SAFEPOINT +void +unblock_gc_signals(sigset_t *where, sigset_t *old) +{ +#ifndef LISP_FEATURE_WIN32 + unblock_signals(&gc_sigset, where, old); +#endif +} +#endif + +void +unblock_signals_in_context_and_maybe_warn(os_context_t *context) +{ +#if !defined(LISP_FEATURE_WIN32) || defined(LISP_FEATURE_SB_THREAD) + sigset_t *sigset = os_context_sigmask_addr(context); +#ifndef LISP_FEATURE_SB_SAFEPOINT + if (all_signals_blocked_p(sigset, &gc_sigset, "gc")) { + corruption_warning_and_maybe_lose( +"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"); + unblock_gc_signals(sigset, 0); + } +#endif + if (!interrupt_handler_pending_p()) { + unblock_deferrable_signals(sigset, 0); + } +#endif +} + + +inline static void +check_interrupts_enabled_or_lose(os_context_t *context) +{ + struct thread *thread=arch_os_get_current_thread(); + if (SymbolValue(INTERRUPTS_ENABLED,thread) == NIL) + lose("interrupts not enabled\n"); + if (arch_pseudo_atomic_atomic(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.*/ +#ifndef LISP_FEATURE_SB_SAFEPOINT +void +maybe_save_gc_mask_and_block_deferrables(sigset_t *sigset) +{ +#ifndef LISP_FEATURE_WIN32 + 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. */ + block_blockable_signals(0, &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); + thread_sigmask(SIG_UNBLOCK, &gc_sigset, 0); + return; + } + } + thread_sigmask(SIG_SETMASK,&oldset,0); +#endif +} +#endif + +/* 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) +{ +#if !defined(LISP_FEATURE_WIN32) || defined(LISP_FEATURE_SB_THREAD) + 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(GENCGC_IS_PRECISE) + 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"); + if (pseudo_atomic_interrupted) + if (!(gc_pending || stop_for_gc_pending || interrupt_deferred_p)) + lose("pseudo_atomic_interrupted, but why?\n"); + } +#else + if (pseudo_atomic_interrupted) + if (!(gc_pending || interrupt_deferred_p)) + lose("pseudo_atomic_interrupted, 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_or_lose(sigset); + if (interrupt_pending || interrupt_deferred_p || + data->gc_blocked_deferrables) + check_deferrables_blocked_or_lose(sigset); + else { + check_deferrables_unblocked_or_lose(sigset); +#ifndef LISP_FEATURE_SB_SAFEPOINT + /* If deferrables are unblocked then we are open to signals + * that run lisp code. */ + check_gc_signals_unblocked_or_lose(sigset); +#endif + } +#endif +} + +/* + * utility routines used by various signal handlers + */ + +static void +build_fake_control_stack_frames(struct thread *th,os_context_t *context) +{ +#ifndef LISP_FEATURE_C_STACK_IS_CONTROL_STACK + + lispobj oldcont; + + /* Build a fake stack frame or frames */ + + access_control_frame_pointer(th) = + (lispobj *)(uword_t) + (*os_context_register_addr(context, reg_CSP)); + if ((lispobj *)(uword_t) + (*os_context_register_addr(context, reg_CFP)) + == access_control_frame_pointer(th)) { + /* There is a small window during call where the callee's + * frame isn't built yet. */ + if (lowtag_of(*os_context_register_addr(context, reg_CODE)) + == FUN_POINTER_LOWTAG) { + /* We have called, but not built the new frame, so + * build it for them. */ + access_control_frame_pointer(th)[0] = + *os_context_register_addr(context, reg_OCFP); + access_control_frame_pointer(th)[1] = + *os_context_register_addr(context, reg_LRA); + access_control_frame_pointer(th) += 8; + /* Build our frame on top of it. */ + oldcont = (lispobj)(*os_context_register_addr(context, reg_CFP)); + } + else { + /* We haven't yet called, build our frame as if the + * partial frame wasn't there. */ + oldcont = (lispobj)(*os_context_register_addr(context, reg_OCFP)); + } + } + /* We can't tell whether we are still in the caller if it had to + * allocate a stack frame due to stack arguments. */ + /* This observation provoked some past CMUCL maintainer to ask + * "Can anything strange happen during return?" */ + else { + /* normal case */ + oldcont = (lispobj)(*os_context_register_addr(context, reg_CFP)); + } + + access_control_stack_pointer(th) = access_control_frame_pointer(th) + 8; + + access_control_frame_pointer(th)[0] = oldcont; + access_control_frame_pointer(th)[1] = NIL; + access_control_frame_pointer(th)[2] = + (lispobj)(*os_context_register_addr(context, reg_CODE)); +#endif +} + +/* Stores the context for gc to scavange and builds fake stack + * frames. */ +void +fake_foreign_function_call(os_context_t *context) +{ + int context_index; + struct thread *thread=arch_os_get_current_thread(); + + /* context_index incrementing must not be interrupted */ + check_blockables_blocked_or_lose(0); + + /* Get current Lisp state from context. */ +#ifdef reg_ALLOC +#ifdef LISP_FEATURE_SB_THREAD + thread->pseudo_atomic_bits = +#else + dynamic_space_free_pointer = + (lispobj *)(uword_t) +#endif + (*os_context_register_addr(context, reg_ALLOC)); +/* fprintf(stderr,"dynamic_space_free_pointer: %p\n", */ +/* dynamic_space_free_pointer); */ +#if defined(LISP_FEATURE_ALPHA) || defined(LISP_FEATURE_MIPS) + if ((sword_t)dynamic_space_free_pointer & 1) { + lose("dead in fake_foreign_function_call, context = %x\n", context); + } +#endif +/* why doesnt PPC and SPARC do something like this: */ +#if defined(LISP_FEATURE_HPPA) + if ((sword_t)dynamic_space_free_pointer & 4) { + lose("dead in fake_foreign_function_call, context = %x, d_s_f_p = %x\n", context, dynamic_space_free_pointer); + } +#endif +#endif +#ifdef reg_BSP + set_binding_stack_pointer(thread, + *os_context_register_addr(context, reg_BSP)); +#endif + + build_fake_control_stack_frames(thread,context); + + /* Do dynamic binding of the active interrupt context index + * and save the context in the context array. */ + context_index = + fixnum_value(SymbolValue(FREE_INTERRUPT_CONTEXT_INDEX,thread)); + + if (context_index >= MAX_INTERRUPTS) { + lose("maximum interrupt nesting depth (%d) exceeded\n", MAX_INTERRUPTS); + } + + bind_variable(FREE_INTERRUPT_CONTEXT_INDEX, + make_fixnum(context_index + 1),thread); + + thread->interrupt_contexts[context_index] = context; + +#if !defined(LISP_FEATURE_X86) && !defined(LISP_FEATURE_X86_64) + /* x86oid targets don't maintain the foreign function call flag at + * all, so leave them to believe that they are never in foreign + * code. */ + foreign_function_call_active_p(thread) = 1; +#endif +} + +/* 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) +{ + struct thread *thread=arch_os_get_current_thread(); + /* Block all blockable signals. */ + block_blockable_signals(0, 0); + + foreign_function_call_active_p(thread) = 0; + + /* Undo dynamic binding of FREE_INTERRUPT_CONTEXT_INDEX */ + unbind(thread); + +#if defined(reg_ALLOC) && !defined(LISP_FEATURE_SB_THREAD) + /* Put the dynamic space free pointer back into the context. */ + *os_context_register_addr(context, reg_ALLOC) = + (uword_t) dynamic_space_free_pointer + | (*os_context_register_addr(context, reg_ALLOC) + & LOWTAG_MASK); + /* + ((uword_t)(*os_context_register_addr(context, reg_ALLOC)) + & ~LOWTAG_MASK) + | ((uword_t) dynamic_space_free_pointer & LOWTAG_MASK); + */ +#endif +#if defined(reg_ALLOC) && defined(LISP_FEATURE_SB_THREAD) + /* Put the pseudo-atomic bits and dynamic space free pointer back + * into the context (p-a-bits for p-a, and dynamic space free + * pointer for ROOM). */ + *os_context_register_addr(context, reg_ALLOC) = + (uword_t) dynamic_space_free_pointer + | (thread->pseudo_atomic_bits & LOWTAG_MASK); + /* And clear them so we don't get bit later by call-in/call-out + * not updating them. */ + thread->pseudo_atomic_bits = 0; +#endif +} + +/* a handler for the signal caused by execution of a trap opcode + * signalling an internal error */ +void +interrupt_internal_error(os_context_t *context, boolean continuable) +{ + lispobj context_sap; + + 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. */ +#ifndef LISP_FEATURE_SB_SAFEPOINT + unblock_gc_signals(0, 0); +#endif + context_sap = alloc_sap(context); + +#if !defined(LISP_FEATURE_WIN32) || defined(LISP_FEATURE_SB_THREAD) + 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"); +#if QSHOW == 2 + /* 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(StaticSymbolFunction(INTERNAL_ERROR), context_sap, + continuable ? T : NIL); + + undo_fake_foreign_function_call(context); /* blocks signals again */ + if (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) +{ + /* There are three ways we can get here. First, if an interrupt + * occurs within pseudo-atomic, it will be deferred, and we'll + * trap to here at the end of the pseudo-atomic block. Second, if + * the GC (in alloc()) decides that a GC is required, it will set + * *GC-PENDING* and pseudo-atomic-interrupted if not *GC-INHIBIT*, + * and alloc() is always called from within pseudo-atomic, and + * thus we end up here again. Third, when calling GC-ON or at the + * end of a WITHOUT-GCING, MAYBE-HANDLE-PENDING-GC will trap to + * here if there is a pending GC. Fourth, ahem, at the end of + * WITHOUT-INTERRUPTS (bar complications with nesting). + * + * A fourth way happens with safepoints: In addition to a stop for + * GC that is pending, there are thruptions. Both mechanisms are + * mostly signal-free, yet also of an asynchronous nature, so it makes + * sense to let interrupt_handle_pending take care of running them: + * It gets run precisely at those places where it is safe to process + * pending asynchronous tasks. */ + + struct thread *thread = arch_os_get_current_thread(); + struct interrupt_data *data = thread->interrupt_data; + + if (arch_pseudo_atomic_atomic(context)) { + lose("Handling pending interrupt in pseudo atomic."); + } + + FSHOW_SIGNAL((stderr, "/entering interrupt_handle_pending\n")); + + check_blockables_blocked_or_lose(0); +#ifndef LISP_FEATURE_SB_SAFEPOINT + /* + * (On safepoint builds, there is no gc_blocked_deferrables nor + * SIG_STOP_FOR_GC.) + */ + /* 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. */ +#ifndef LISP_FEATURE_WIN32 + sigcopyset(os_context_sigmask_addr(context), &data->pending_mask); +#endif + data->gc_blocked_deferrables = 0; + } +#endif + + if (SymbolValue(GC_INHIBIT,thread)==NIL) { + void *original_pending_handler = data->pending_handler; + +#ifdef LISP_FEATURE_SB_SAFEPOINT + /* handles the STOP_FOR_GC_PENDING case, plus THRUPTIONS */ + if (SymbolValue(STOP_FOR_GC_PENDING,thread) != NIL +# ifdef LISP_FEATURE_SB_THRUPTION + || (SymbolValue(THRUPTION_PENDING,thread) != NIL + && SymbolValue(INTERRUPTS_ENABLED, thread) != NIL) +# endif + ) + /* We ought to take this chance to do a pitstop now. */ + thread_in_lisp_raised(context); +#elif defined(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 + /* 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. + * + * 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(0); + + /* 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 THREADS_USING_GCSIGNAL + 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 -> %x.", + original_pending_handler, data->pending_handler); + } + +#ifndef LISP_FEATURE_WIN32 + /* 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); + run_deferred_handler(data, context); + } +#ifdef LISP_FEATURE_SB_THRUPTION + if (SymbolValue(THRUPTION_PENDING,thread)==T) + /* Special case for the following situation: There is a + * thruption pending, but a signal had been deferred. The + * pitstop at the top of this function could only take care + * of GC, and skipped the thruption, so we need to try again + * now that INTERRUPT_PENDING and the sigmask have been + * reset. */ + while (check_pending_thruptions(context)) + ; +#endif +#endif +#ifdef LISP_FEATURE_GENCGC + if (get_pseudo_atomic_interrupted(thread)) + lose("pseudo_atomic_interrupted after interrupt_handle_pending\n"); +#endif + /* 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")); +} + + +void +interrupt_handle_now(int signal, siginfo_t *info, os_context_t *context) +{ + boolean were_in_lisp; + union interrupt_handler handler; + + check_blockables_blocked_or_lose(0); + +#if !defined(LISP_FEATURE_WIN32) || defined(LISP_FEATURE_SB_THREAD) + if (sigismember(&deferrable_sigset,signal)) + check_interrupts_enabled_or_lose(context); +#endif + + handler = interrupt_handlers[signal]; + + if (ARE_SAME_HANDLER(handler.c, SIG_IGN)) { + return; + } + + were_in_lisp = !foreign_function_call_active_p(arch_os_get_current_thread()); + if (were_in_lisp) + { + fake_foreign_function_call(context); + } + + 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(..)\n", signal); + + } else if (lowtag_of(handler.lisp) == FUN_POINTER_LOWTAG) { + /* Once we've decided what to do about contexts in a + * return-elsewhere world (the original context will no longer + * be available; should we copy it or was nobody using it anyway?) + * then we should convert this to return-elsewhere */ + + /* CMUCL comment said "Allocate the SAPs while the interrupts + * are still disabled.". I (dan, 2003.08.21) assume this is + * 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. + * + * Yeah, but non-gencgc platforms don't really wrap allocation + * in PA. MG - 2005-08-29 */ + + lispobj info_sap, context_sap; + /* Leave deferrable signals blocked, the handler itself will + * allow signals again when it sees fit. */ +#ifndef LISP_FEATURE_SB_SAFEPOINT + unblock_gc_signals(0, 0); +#endif + context_sap = alloc_sap(context); + info_sap = alloc_sap(info); + + FSHOW_SIGNAL((stderr,"/calling Lisp-level handler\n")); + +#ifdef LISP_FEATURE_SB_SAFEPOINT + WITH_GC_AT_SAFEPOINTS_ONLY() +#endif + funcall3(handler.lisp, + make_fixnum(signal), + info_sap, + context_sap); + } else { + /* This cannot happen in sane circumstances. */ + + FSHOW_SIGNAL((stderr,"/calling C-level handler\n")); + +#if !defined(LISP_FEATURE_WIN32) || defined(LISP_FEATURE_SB_THREAD) + /* Allow signals again. */ + thread_sigmask(SIG_SETMASK, os_context_sigmask_addr(context), 0); + (*handler.c)(signal, info, context); +#endif + } + + if (were_in_lisp) + { + undo_fake_foreign_function_call(context); /* block signals again */ + } + + 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 + * are that some signal was deferred during the section. Note that as + * 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 */ +static void +run_deferred_handler(struct interrupt_data *data, os_context_t *context) +{ + /* 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*, os_context_t*) = + 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), context); +} + +#ifndef LISP_FEATURE_WIN32 +boolean +maybe_defer_handler(void *handler, struct interrupt_data *data, + int signal, siginfo_t *info, os_context_t *context) +{ + struct thread *thread=arch_os_get_current_thread(); + + check_blockables_blocked_or_lose(0); + + 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) || + in_leaving_without_gcing_race_p(thread)) { + FSHOW_SIGNAL((stderr, + "/maybe_defer_handler(%x,%d): deferred (RACE=%d)\n", + (unsigned int)handler,signal, + in_leaving_without_gcing_race_p(thread))); + store_signal_data_for_later(data,handler,signal,info,context); + SetSymbolValue(INTERRUPT_PENDING, T,thread); + check_interrupt_context_or_lose(context); + return 1; + } + /* a slightly confusing test. arch_pseudo_atomic_atomic() doesn't + * actually use its argument for anything on x86, so this branch + * may succeed even when context is null (gencgc alloc()) */ + if (arch_pseudo_atomic_atomic(context)) { + FSHOW_SIGNAL((stderr, + "/maybe_defer_handler(%x,%d): deferred(PA)\n", + (unsigned int)handler,signal)); + store_signal_data_for_later(data,handler,signal,info,context); + arch_set_pseudo_atomic_interrupted(context); + check_interrupt_context_or_lose(context); + return 1; + } + FSHOW_SIGNAL((stderr, + "/maybe_defer_handler(%x,%d): not deferred\n", + (unsigned int)handler,signal)); + return 0; +} + +static void +store_signal_data_for_later (struct interrupt_data *data, void *handler, + int signal, + siginfo_t *info, os_context_t *context) +{ + if (data->pending_handler) + lose("tried to overwrite pending interrupt handler %x with %x\n", + data->pending_handler, handler); + if (!handler) + lose("tried to defer null interrupt handler\n"); + data->pending_handler = handler; + data->pending_signal = signal; + if(info) + memcpy(&(data->pending_info), info, sizeof(siginfo_t)); + + FSHOW_SIGNAL((stderr, "/store_signal_data_for_later: signal: %d\n", + signal)); + + 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 +maybe_now_maybe_later(int signal, siginfo_t *info, void *void_context) +{ + SAVE_ERRNO(signal,context,void_context); + struct thread *thread = arch_os_get_current_thread(); + struct interrupt_data *data = thread->interrupt_data; + if(!maybe_defer_handler(interrupt_handle_now,data,signal,info,context)) + interrupt_handle_now(signal, info, context); + RESTORE_ERRNO; +} + +static void +low_level_interrupt_handle_now(int signal, siginfo_t *info, + os_context_t *context) +{ + /* No FP control fixage needed, caller has done that. */ + check_blockables_blocked_or_lose(0); + check_interrupts_enabled_or_lose(context); + (*interrupt_low_level_handlers[signal])(signal, info, context); + /* No Darwin context fixage needed, caller does that. */ +} -/* signal number, siginfo_t, and old mask information for pending signal - * - * pending_signal=0 when there is no pending signal. */ -static int pending_signal = 0; -static siginfo_t pending_info; -static sigset_t pending_mask; +static void +low_level_maybe_now_maybe_later(int signal, siginfo_t *info, void *void_context) +{ + SAVE_ERRNO(signal,context,void_context); + struct thread *thread = arch_os_get_current_thread(); + struct interrupt_data *data = thread->interrupt_data; + + if(!maybe_defer_handler(low_level_interrupt_handle_now,data, + signal,info,context)) + low_level_interrupt_handle_now(signal, info, context); + RESTORE_ERRNO; +} +#endif -static boolean maybe_gc_pending = 0; - -/* - * utility routines used by various signal handlers - */ +#ifdef THREADS_USING_GCSIGNAL +/* This function must not cons, because that may trigger a GC. */ void -fake_foreign_function_call(os_context_t *context) +sig_stop_for_gc_handler(int signal, siginfo_t *info, os_context_t *context) { - int context_index; -#ifndef __i386__ - lispobj oldcont; -#endif + struct thread *thread=arch_os_get_current_thread(); + boolean was_in_lisp; + + /* 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) { + FSHOW_SIGNAL((stderr, "sig_stop_for_gc deferred (*GC-INHIBIT*)\n")); + SetSymbolValue(STOP_FOR_GC_PENDING,T,thread); + return; + } else if (arch_pseudo_atomic_atomic(context)) { + FSHOW_SIGNAL((stderr,"sig_stop_for_gc deferred (PA)\n")); + SetSymbolValue(STOP_FOR_GC_PENDING,T,thread); + arch_set_pseudo_atomic_interrupted(context); + maybe_save_gc_mask_and_block_deferrables + (os_context_sigmask_addr(context)); + return; + } - /* Get current Lisp state from context. */ -#ifdef reg_ALLOC - dynamic_space_free_pointer = - (lispobj *)(*os_context_register_addr(context, reg_ALLOC)); -#ifdef alpha - if ((long)dynamic_space_free_pointer & 1) { - lose("dead in fake_foreign_function_call, context = %x", context); + FSHOW_SIGNAL((stderr, "/sig_stop_for_gc_handler\n")); + + /* Not PA and GC not inhibited -- we can stop now. */ + + was_in_lisp = !foreign_function_call_active_p(arch_os_get_current_thread()); + + if (was_in_lisp) { + /* need the context stored so it can have registers scavenged */ + fake_foreign_function_call(context); } -#endif -#endif -#ifdef reg_BSP - current_binding_stack_pointer = - (lispobj *)(*os_context_register_addr(context, reg_BSP)); -#endif -#ifndef __i386__ - /* Build a fake stack frame. */ - current_control_frame_pointer = - (lispobj *)(*os_context_register_addr(context, reg_CSP)); - if ((lispobj *)(*os_context_register_addr(context, reg_CFP)) - == current_control_frame_pointer) { - /* There is a small window during call where the callee's - * frame isn't built yet. */ - if (lowtag_of(*os_context_register_addr(context, reg_CODE)) - == FUN_POINTER_LOWTAG) { - /* We have called, but not built the new frame, so - * build it for them. */ - current_control_frame_pointer[0] = - *os_context_register_addr(context, reg_OCFP); - current_control_frame_pointer[1] = - *os_context_register_addr(context, reg_LRA); - current_control_frame_pointer += 8; - /* Build our frame on top of it. */ - oldcont = (lispobj)(*os_context_register_addr(context, reg_CFP)); - } - else { - /* We haven't yet called, build our frame as if the - * partial frame wasn't there. */ - oldcont = (lispobj)(*os_context_register_addr(context, reg_OCFP)); - } + /* Not pending anymore. */ + SetSymbolValue(GC_PENDING,NIL,thread); + SetSymbolValue(STOP_FOR_GC_PENDING,NIL,thread); + + /* Consider this: in a PA section GC is requested: GC_PENDING, + * pseudo_atomic_interrupted and gc_blocked_deferrables are set, + * deferrables are blocked then pseudo_atomic_atomic is cleared, + * but a SIG_STOP_FOR_GC arrives before trapping to + * interrupt_handle_pending. Here, GC_PENDING is cleared but + * pseudo_atomic_interrupted is not and we go on running with + * pseudo_atomic_interrupted but without a pending interrupt or + * GC. GC_BLOCKED_DEFERRABLES is also left at 1. So let's tidy it + * up. */ + if (thread->interrupt_data->gc_blocked_deferrables) { + FSHOW_SIGNAL((stderr,"cleaning up after gc_blocked_deferrables\n")); + clear_pseudo_atomic_interrupted(thread); + sigcopyset(os_context_sigmask_addr(context), + &thread->interrupt_data->pending_mask); + thread->interrupt_data->gc_blocked_deferrables = 0; } - /* ### We can't tell whether we are still in the caller if it had - * to reg_ALLOCate the stack frame due to stack arguments. */ - /* ### Can anything strange happen during return? */ - else { - /* normal case */ - oldcont = (lispobj)(*os_context_register_addr(context, reg_CFP)); + + if(thread_state(thread)!=STATE_RUNNING) { + lose("sig_stop_for_gc_handler: wrong thread state: %ld\n", + fixnum_value(thread->state)); } - current_control_stack_pointer = current_control_frame_pointer + 8; + set_thread_state(thread,STATE_STOPPED); + FSHOW_SIGNAL((stderr,"suspended\n")); - current_control_frame_pointer[0] = oldcont; - current_control_frame_pointer[1] = NIL; - current_control_frame_pointer[2] = - (lispobj)(*os_context_register_addr(context, reg_CODE)); -#endif + /* While waiting for gc to finish occupy ourselves with zeroing + * the unused portion of the control stack to reduce conservatism. + * On hypothetic platforms with threads and exact gc it is + * actually a must. */ + scrub_control_stack(); - /* Do dynamic binding of the active interrupt context index - * and save the context in the context array. */ - context_index = SymbolValue(FREE_INTERRUPT_CONTEXT_INDEX)>>2; - /* FIXME: Ick! Why use abstract "make_fixnum" in some places if - * you're going to convert from fixnum by bare >>2 in other - * places? Use fixnum_value(..) here, and look for other places - * which do bare >> and << for fixnum_value and make_fixnum. */ + wait_for_thread_state_change(thread, STATE_STOPPED); + FSHOW_SIGNAL((stderr,"resumed\n")); - if (context_index >= MAX_INTERRUPTS) { - lose("maximum interrupt nesting depth (%d) exceeded", - MAX_INTERRUPTS); + if(thread_state(thread)!=STATE_RUNNING) { + lose("sig_stop_for_gc_handler: wrong thread state on wakeup: %ld\n", + fixnum_value(thread_state(thread))); } - bind_variable(FREE_INTERRUPT_CONTEXT_INDEX, - make_fixnum(context_index + 1)); - - lisp_interrupt_contexts[context_index] = context; - - /* no longer in Lisp now */ - foreign_function_call_active = 1; + if (was_in_lisp) { + undo_fake_foreign_function_call(context); + } } +#endif + void -undo_fake_foreign_function_call(os_context_t *context) +interrupt_handle_now_handler(int signal, siginfo_t *info, void *void_context) { - /* Block all blockable signals. */ - sigset_t block; - sigemptyset(&block); - sigaddset_blockable(&block); - sigprocmask(SIG_BLOCK, &block, 0); - - /* going back into Lisp */ - foreign_function_call_active = 0; - - /* Undo dynamic binding. */ - /* ### Do I really need to unbind_to_here()? */ - /* FIXME: Is this to undo the binding of - * FREE_INTERRUPT_CONTEXT_INDEX? If so, we should say so. And - * perhaps yes, unbind_to_here() really would be clearer and less - * fragile.. */ - /* dan (2001.08.10) thinks the above supposition is probably correct */ - unbind(); - -#ifdef reg_ALLOC - /* Put the dynamic space free pointer back into the context. */ - *os_context_register_addr(context, reg_ALLOC) = - (unsigned long) dynamic_space_free_pointer; + SAVE_ERRNO(signal,context,void_context); +#ifndef LISP_FEATURE_WIN32 + if ((signal == SIGILL) || (signal == SIGBUS) +#ifndef LISP_FEATURE_LINUX + || (signal == SIGEMT) #endif + ) + corruption_warning_and_maybe_lose("Signal %d received", signal); +#endif + interrupt_handle_now(signal, info, context); + RESTORE_ERRNO; } -/* a handler for the signal caused by execution of a trap opcode - * signalling an internal error */ +/* manipulate the signal context and stack such that when the handler + * returns, it will call function instead of whatever it was doing + * previously + */ + +#if (defined(LISP_FEATURE_X86) || defined(LISP_FEATURE_X86_64)) +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); +extern void call_into_lisp_tramp(void); + void -interrupt_internal_error(int signal, siginfo_t *info, os_context_t *context, - boolean continuable) +arrange_return_to_c_function(os_context_t *context, + call_into_lisp_lookalike funptr, + lispobj function) { - lispobj context_sap = 0; +#if !(defined(LISP_FEATURE_WIN32) || defined(LISP_FEATURE_SB_SAFEPOINT)) + check_gc_signals_unblocked_or_lose + (os_context_sigmask_addr(context)); +#endif +#if !(defined(LISP_FEATURE_X86) || defined(LISP_FEATURE_X86_64)) + void * fun=native_pointer(function); + void *code = &(((struct simple_fun *) fun)->code); +#endif - fake_foreign_function_call(context); + /* Build a stack frame showing `interrupted' so that the + * user's backtrace makes (as much) sense (as usual) */ + + /* fp state is saved and restored by call_into_lisp */ + /* FIXME: errno is not restored, but since current uses of this + * function only call Lisp code that signals an error, it's not + * much of a problem. In other words, running out of the control + * stack between a syscall and (GET-ERRNO) may clobber errno if + * something fails during signalling or in the handler. But I + * can't see what can go wrong as long as there is no CONTINUE + * like restart on them. */ +#ifdef LISP_FEATURE_X86 + /* Suppose the existence of some function that saved all + * registers, called call_into_lisp, then restored GP registers and + * returned. It would look something like this: + + push ebp + mov ebp esp + pushfl + pushal + push $0 + push $0 + pushl {address of function to call} + call 0x8058db0 + addl $12,%esp + popal + popfl + leave + ret + + * What we do here is set up the stack that call_into_lisp would + * expect to see if it had been called by this code, and frob the + * signal context so that signal return goes directly to call_into_lisp, + * and when that function (and the lisp function it invoked) returns, + * it returns to the second half of this imaginary function which + * restores all registers and returns to C + + * For this to work, the latter part of the imaginary function + * must obviously exist in reality. That would be post_signal_tramp + */ - /* Allocate the SAP object while the interrupts are still - * disabled. */ - if (internal_errors_enabled) { - context_sap = alloc_sap(context); - } + u32 *sp=(u32 *)*os_context_register_addr(context,reg_ESP); - sigprocmask(SIG_SETMASK, os_context_sigmask_addr(context), 0); +#if defined(LISP_FEATURE_DARWIN) + u32 *register_save_area = (u32 *)os_validate(0, 0x40); - if (internal_errors_enabled) { - SHOW("in interrupt_internal_error"); -#if 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); -#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"); - } - undo_fake_foreign_function_call(context); - if (continuable) { - arch_skip_instruction(context); - } -} + FSHOW_SIGNAL((stderr, "/arrange_return_to_lisp_function: preparing to go to function %x, sp: %x\n", function, sp)); + FSHOW_SIGNAL((stderr, "/arrange_return_to_lisp_function: context: %x, &context %x\n", context, &context)); -/* This function handles pending interrupts. Note that in C/kernel - * terms we dealt with the signal already; we just haven't decided - * whether to call a Lisp handler or do a GC or something like that. - * If it helps, you can think of pending_{signal,mask,info} as a - * one-element queue of signals that we have acknowledged but not - * processed */ + /* 1. os_validate (malloc/mmap) register_save_block + * 2. copy register state into register_save_block + * 3. put a pointer to register_save_block in a register in the context + * 4. set the context's EIP to point to a trampoline which: + * a. builds the fake stack frame from the block + * b. frees the block + * c. calls the function + */ + + *register_save_area = *os_context_pc_addr(context); + *(register_save_area + 1) = function; + *(register_save_area + 2) = *os_context_register_addr(context,reg_EDI); + *(register_save_area + 3) = *os_context_register_addr(context,reg_ESI); + *(register_save_area + 4) = *os_context_register_addr(context,reg_EDX); + *(register_save_area + 5) = *os_context_register_addr(context,reg_ECX); + *(register_save_area + 6) = *os_context_register_addr(context,reg_EBX); + *(register_save_area + 7) = *os_context_register_addr(context,reg_EAX); + *(register_save_area + 8) = *context_eflags_addr(context); + + *os_context_pc_addr(context) = + (os_context_register_t) funptr; + *os_context_register_addr(context,reg_ECX) = + (os_context_register_t) register_save_area; +#else + + /* return address for call_into_lisp: */ + *(sp-15) = (u32)post_signal_tramp; + *(sp-14) = function; /* args for call_into_lisp : function*/ + *(sp-13) = 0; /* arg array */ + *(sp-12) = 0; /* no. args */ + /* this order matches that used in POPAD */ + *(sp-11)=*os_context_register_addr(context,reg_EDI); + *(sp-10)=*os_context_register_addr(context,reg_ESI); + + *(sp-9)=*os_context_register_addr(context,reg_ESP)-8; + /* POPAD ignores the value of ESP: */ + *(sp-8)=0; + *(sp-7)=*os_context_register_addr(context,reg_EBX); + + *(sp-6)=*os_context_register_addr(context,reg_EDX); + *(sp-5)=*os_context_register_addr(context,reg_ECX); + *(sp-4)=*os_context_register_addr(context,reg_EAX); + *(sp-3)=*context_eflags_addr(context); + *(sp-2)=*os_context_register_addr(context,reg_EBP); + *(sp-1)=*os_context_pc_addr(context); -void -interrupt_handle_pending(os_context_t *context) -{ -#ifndef __i386__ - boolean were_in_lisp = !foreign_function_call_active; #endif - SetSymbolValue(INTERRUPT_PENDING, NIL); +#elif defined(LISP_FEATURE_X86_64) + u64 *sp=(u64 *)*os_context_register_addr(context,reg_RSP); + + /* return address for call_into_lisp: */ + *(sp-18) = (u64)post_signal_tramp; + + *(sp-17)=*os_context_register_addr(context,reg_R15); + *(sp-16)=*os_context_register_addr(context,reg_R14); + *(sp-15)=*os_context_register_addr(context,reg_R13); + *(sp-14)=*os_context_register_addr(context,reg_R12); + *(sp-13)=*os_context_register_addr(context,reg_R11); + *(sp-12)=*os_context_register_addr(context,reg_R10); + *(sp-11)=*os_context_register_addr(context,reg_R9); + *(sp-10)=*os_context_register_addr(context,reg_R8); + *(sp-9)=*os_context_register_addr(context,reg_RDI); + *(sp-8)=*os_context_register_addr(context,reg_RSI); + /* skip RBP and RSP */ + *(sp-7)=*os_context_register_addr(context,reg_RBX); + *(sp-6)=*os_context_register_addr(context,reg_RDX); + *(sp-5)=*os_context_register_addr(context,reg_RCX); + *(sp-4)=*os_context_register_addr(context,reg_RAX); + *(sp-3)=*context_eflags_addr(context); + *(sp-2)=*os_context_register_addr(context,reg_RBP); + *(sp-1)=*os_context_pc_addr(context); + + *os_context_register_addr(context,reg_RDI) = + (os_context_register_t)function; /* function */ + *os_context_register_addr(context,reg_RSI) = 0; /* arg. array */ + *os_context_register_addr(context,reg_RDX) = 0; /* no. args */ +#else + struct thread *th=arch_os_get_current_thread(); + build_fake_control_stack_frames(th,context); +#endif - if (maybe_gc_pending) { - maybe_gc_pending = 0; -#ifndef __i386__ - if (were_in_lisp) +#ifdef LISP_FEATURE_X86 + +#if !defined(LISP_FEATURE_DARWIN) + *os_context_pc_addr(context) = (os_context_register_t)funptr; + *os_context_register_addr(context,reg_ECX) = 0; + *os_context_register_addr(context,reg_EBP) = (os_context_register_t)(sp-2); +#ifdef __NetBSD__ + *os_context_register_addr(context,reg_UESP) = + (os_context_register_t)(sp-15); +#else + *os_context_register_addr(context,reg_ESP) = (os_context_register_t)(sp-15); +#endif /* __NETBSD__ */ +#endif /* LISP_FEATURE_DARWIN */ + +#elif defined(LISP_FEATURE_X86_64) + *os_context_pc_addr(context) = (os_context_register_t)funptr; + *os_context_register_addr(context,reg_RCX) = 0; + *os_context_register_addr(context,reg_RBP) = (os_context_register_t)(sp-2); + *os_context_register_addr(context,reg_RSP) = (os_context_register_t)(sp-18); +#else + /* this much of the calling convention is common to all + non-x86 ports */ + *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)(unsigned long)code; + *os_context_register_addr(context,reg_CFP) = + (os_context_register_t)(unsigned long)access_control_frame_pointer(th); #endif - { - fake_foreign_function_call(context); - } - funcall0(SymbolFunction(MAYBE_GC)); -#ifndef __i386__ - if (were_in_lisp) +#ifdef ARCH_HAS_NPC_REGISTER + *os_context_npc_addr(context) = + 4 + *os_context_pc_addr(context); #endif - { - undo_fake_foreign_function_call(context); - } - fprintf(stderr,"interrupt-handle-pending: back from MAYBE_GC\n"); - } - - /* FIXME: This isn't very clear. It would be good to reverse - * engineer it and rewrite the code more clearly, or write a clear - * explanation of what's going on in the comments, or both. - * - * WHN's question 1a: How come we unconditionally copy from - * pending_mask into the context, and then test whether - * pending_signal is set? - * - * WHN's question 1b: If pending_signal wasn't set, how could - * pending_mask be valid? - * - * Dan Barlow's reply (sbcl-devel 2001-03-13): And the answer is - - * or appears to be - because interrupt_maybe_gc set it that way - * (look in the #ifndef __i386__ bit). We can't GC during a - * pseudo-atomic, so we set maybe_gc_pending=1 and - * arch_set_pseudo_atomic_interrupted(..) When we come out of - * pseudo_atomic we're marked as interrupted, so we call - * interrupt_handle_pending, which does the GC using the pending - * context (it needs a context so that it has registers to use as - * GC roots) then notices there's no actual interrupt handler to - * call, so doesn't. That's the second question [1b] answered, - * anyway. Why we still need to copy the pending_mask into the - * context given that we're now done with the context anyway, I - * couldn't say. */ -#if 0 - memcpy(os_context_sigmask_addr(context), &pending_mask, - 4 /* sizeof(sigset_t) */ ); -#endif - sigemptyset(&pending_mask); - if (pending_signal) { - int signal = pending_signal; - siginfo_t info; - memcpy(&info, &pending_info, sizeof(siginfo_t)); - pending_signal = 0; - interrupt_handle_now(signal, &info, context); - } +#ifdef LISP_FEATURE_SPARC + *os_context_register_addr(context,reg_CODE) = + (os_context_register_t)(fun + FUN_POINTER_LOWTAG); +#endif + FSHOW((stderr, "/arranged return to Lisp function (0x%lx)\n", + (long)function)); } - -/* - * the two main signal handlers: - * interrupt_handle_now(..) - * maybe_now_maybe_later(..) - */ void -interrupt_handle_now(int signal, siginfo_t *info, void *void_context) +arrange_return_to_lisp_function(os_context_t *context, lispobj function) { - os_context_t *context = (os_context_t*)void_context; -#ifndef __i386__ - boolean were_in_lisp; +#if defined(LISP_FEATURE_DARWIN) && defined(LISP_FEATURE_X86) + arrange_return_to_c_function(context, call_into_lisp_tramp, function); +#else + arrange_return_to_c_function(context, call_into_lisp, function); #endif - union interrupt_handler handler; +} - /* FIXME: The CMU CL we forked off of had this Linux-only - * operation here. Newer CMU CLs (e.g. 18c) have hairier - * Linux/i386-only logic here. SBCL seems to be more reliable - * without anything here. However, if we start supporting code - * which sets the rounding mode, then we may want to do something - * special to force the rounding mode back to some standard value - * here, so that ISRs can have a standard environment. (OTOH, if - * rounding modes are under user control, then perhaps we should - * leave this up to the user.) - * - * In the absence of a test case to show that this is really a - * problem, we just suppress this code completely (just like the - * parallel code in maybe_now_maybe_later). - * #ifdef __linux__ - * SET_FPU_CONTROL_WORD(context->__fpregs_mem.cw); - * #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, + * that has the added benefit of automatically discriminating between + * functions and variables. + */ +void +undefined_alien_function(void) +{ + funcall0(StaticSymbolFunction(UNDEFINED_ALIEN_FUNCTION_ERROR)); +} - handler = interrupt_handlers[signal]; +void lower_thread_control_stack_guard_page(struct thread *th) +{ + protect_control_stack_guard_page(0, th); + protect_control_stack_return_guard_page(1, th); + th->control_stack_guard_page_protected = NIL; + fprintf(stderr, "INFO: Control stack guard page unprotected\n"); +} - if (ARE_SAME_HANDLER(handler.c, SIG_IGN)) { - return; +void reset_thread_control_stack_guard_page(struct thread *th) +{ + memset(CONTROL_STACK_GUARD_PAGE(th), 0, os_vm_page_size); + protect_control_stack_guard_page(1, th); + protect_control_stack_return_guard_page(0, th); + th->control_stack_guard_page_protected = T; + fprintf(stderr, "INFO: Control stack guard page reprotected\n"); +} + +/* Called from the REPL, too. */ +void reset_control_stack_guard_page(void) +{ + struct thread *th=arch_os_get_current_thread(); + if (th->control_stack_guard_page_protected == NIL) { + reset_thread_control_stack_guard_page(th); } - -#ifndef __i386__ - were_in_lisp = !foreign_function_call_active; - if (were_in_lisp) +} + +void lower_control_stack_guard_page(void) +{ + lower_thread_control_stack_guard_page(arch_os_get_current_thread()); +} + +boolean +handle_guard_page_triggered(os_context_t *context,os_vm_address_t addr) +{ + struct thread *th=arch_os_get_current_thread(); + + if(addr >= CONTROL_STACK_HARD_GUARD_PAGE(th) && + addr < CONTROL_STACK_HARD_GUARD_PAGE(th) + os_vm_page_size) { + lose("Control stack exhausted"); + } + else if(addr >= CONTROL_STACK_GUARD_PAGE(th) && + addr < CONTROL_STACK_GUARD_PAGE(th) + os_vm_page_size) { + /* We hit the end of the control stack: disable guard page + * 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. */ + if (th->control_stack_guard_page_protected == NIL) + lose("control_stack_guard_page_protected NIL"); + lower_control_stack_guard_page(); +#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 - { - fake_foreign_function_call(context); + arrange_return_to_lisp_function + (context, StaticSymbolFunction(CONTROL_STACK_EXHAUSTED_ERROR)); + return 1; + } + else if(addr >= CONTROL_STACK_RETURN_GUARD_PAGE(th) && + addr < CONTROL_STACK_RETURN_GUARD_PAGE(th) + os_vm_page_size) { + /* We're returning from the guard page: reprotect it, and + * unprotect this one. This works even if we somehow missed + * the return-guard-page, and hit it on our way to new + * exhaustion instead. */ + if (th->control_stack_guard_page_protected != NIL) + lose("control_stack_guard_page_protected not NIL"); + reset_control_stack_guard_page(); + return 1; + } + else if(addr >= BINDING_STACK_HARD_GUARD_PAGE(th) && + addr < BINDING_STACK_HARD_GUARD_PAGE(th) + os_vm_page_size) { + lose("Binding stack exhausted"); + } + else if(addr >= BINDING_STACK_GUARD_PAGE(th) && + addr < BINDING_STACK_GUARD_PAGE(th) + os_vm_page_size) { + protect_binding_stack_guard_page(0, NULL); + protect_binding_stack_return_guard_page(1, NULL); + fprintf(stderr, "INFO: Binding stack guard page unprotected\n"); + + /* For the unfortunate case, when the binding stack is + * exhausted in a signal handler. */ + unblock_signals_in_context_and_maybe_warn(context); + arrange_return_to_lisp_function + (context, StaticSymbolFunction(BINDING_STACK_EXHAUSTED_ERROR)); + return 1; + } + else if(addr >= BINDING_STACK_RETURN_GUARD_PAGE(th) && + addr < BINDING_STACK_RETURN_GUARD_PAGE(th) + os_vm_page_size) { + protect_binding_stack_guard_page(1, NULL); + protect_binding_stack_return_guard_page(0, NULL); + fprintf(stderr, "INFO: Binding stack guard page reprotected\n"); + return 1; + } + else if(addr >= ALIEN_STACK_HARD_GUARD_PAGE(th) && + addr < ALIEN_STACK_HARD_GUARD_PAGE(th) + os_vm_page_size) { + lose("Alien stack exhausted"); } + else if(addr >= ALIEN_STACK_GUARD_PAGE(th) && + addr < ALIEN_STACK_GUARD_PAGE(th) + os_vm_page_size) { + protect_alien_stack_guard_page(0, NULL); + protect_alien_stack_return_guard_page(1, NULL); + fprintf(stderr, "INFO: Alien stack guard page unprotected\n"); + + /* For the unfortunate case, when the alien stack is + * exhausted in a signal handler. */ + unblock_signals_in_context_and_maybe_warn(context); + arrange_return_to_lisp_function + (context, StaticSymbolFunction(ALIEN_STACK_EXHAUSTED_ERROR)); + return 1; + } + else if(addr >= ALIEN_STACK_RETURN_GUARD_PAGE(th) && + addr < ALIEN_STACK_RETURN_GUARD_PAGE(th) + os_vm_page_size) { + protect_alien_stack_guard_page(1, NULL); + protect_alien_stack_return_guard_page(0, NULL); + fprintf(stderr, "INFO: Alien stack guard page reprotected\n"); + return 1; + } + else if (addr >= undefined_alien_address && + addr < undefined_alien_address + os_vm_page_size) { + arrange_return_to_lisp_function + (context, StaticSymbolFunction(UNDEFINED_ALIEN_VARIABLE_ERROR)); + return 1; + } + else return 0; +} + +/* + * noise to install handlers + */ -#ifdef QSHOW_SIGNALS - FSHOW((stderr, - "/entering interrupt_handle_now(%d, info, context)\n", - signal)); -#endif +#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. + * + * It turns out that NetBSD's SA_NODEFER doesn't DTRT in a different + * way: if SA_NODEFER is set and the signal is in sa_mask, the signal + * will be unblocked in the sigmask during the signal handler. -- RMK + * X-mas day, 2005 + */ +static volatile int sigaction_nodefer_works = -1; - if (ARE_SAME_HANDLER(handler.c, SIG_DFL)) { +#define SA_NODEFER_TEST_BLOCK_SIGNAL SIGABRT +#define SA_NODEFER_TEST_KILL_SIGNAL SIGUSR1 - /* 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); +static void +sigaction_nodefer_test_handler(int signal, siginfo_t *info, void *void_context) +{ + sigset_t current; + int i; + get_current_sigmask(¤t); + /* There should be exactly two blocked signals: the two we added + * to sa_mask when setting up the handler. NetBSD doesn't block + * the signal we're handling when SA_NODEFER is set; Linux before + * 2.6.13 or so also doesn't block the other signal when + * SA_NODEFER is set. */ + for(i = 1; i < NSIG; i++) + if (sigismember(¤t, i) != + (((i == SA_NODEFER_TEST_BLOCK_SIGNAL) || (i == signal)) ? 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; +} - } else if (lowtag_of(handler.lisp) == FUN_POINTER_LOWTAG) { +static void +see_if_sigaction_nodefer_works(void) +{ + struct sigaction sa, old_sa; - /* Allocate the SAPs while the interrupts are still disabled. - * (FIXME: Why? This is the way it was done in CMU CL, and it - * even had the comment noting that this is the way it was - * done, but no motivation..) */ - lispobj info_sap,context_sap = alloc_sap(context); - info_sap = alloc_sap(info); - /* Allow signals again. */ - sigprocmask(SIG_SETMASK, os_context_sigmask_addr(context), 0); + sa.sa_flags = SA_SIGINFO | SA_NODEFER; + sa.sa_sigaction = sigaction_nodefer_test_handler; + sigemptyset(&sa.sa_mask); + sigaddset(&sa.sa_mask, SA_NODEFER_TEST_BLOCK_SIGNAL); + sigaddset(&sa.sa_mask, SA_NODEFER_TEST_KILL_SIGNAL); + sigaction(SA_NODEFER_TEST_KILL_SIGNAL, &sa, &old_sa); + /* Make sure no signals are blocked. */ + { + sigset_t empty; + sigemptyset(&empty); + thread_sigmask(SIG_SETMASK, &empty, 0); + } + kill(getpid(), SA_NODEFER_TEST_KILL_SIGNAL); + while (sigaction_nodefer_works == -1); + sigaction(SA_NODEFER_TEST_KILL_SIGNAL, &old_sa, NULL); +} -#ifdef QSHOW_SIGNALS - SHOW("calling Lisp-level handler"); -#endif +#undef SA_NODEFER_TEST_BLOCK_SIGNAL +#undef SA_NODEFER_TEST_KILL_SIGNAL - funcall3(handler.lisp, - make_fixnum(signal), - info_sap, - context_sap); - } else { +#if defined(LISP_FEATURE_SB_SAFEPOINT_STRICTLY) && !defined(LISP_FEATURE_WIN32) -#ifdef QSHOW_SIGNALS - SHOW("calling C-level handler"); +static void * +signal_thread_trampoline(void *pthread_arg) +{ + int signo = (int) pthread_arg; + os_context_t fake_context; + siginfo_t fake_info; +#ifdef LISP_FEATURE_PPC + mcontext_t uc_regs; #endif - /* Allow signals again. */ - sigprocmask(SIG_SETMASK, os_context_sigmask_addr(context), 0); - - (*handler.c)(signal, info, void_context); - } - -#ifndef __i386__ - if (were_in_lisp) + memset(&fake_info, 0, sizeof(fake_info)); + memset(&fake_context, 0, sizeof(fake_context)); +#ifdef LISP_FEATURE_PPC + memset(&uc_regs, 0, sizeof(uc_regs)); + fake_context.uc_mcontext.uc_regs = &uc_regs; #endif - { - undo_fake_foreign_function_call(context); - } -#ifdef QSHOW_SIGNALS - FSHOW((stderr, - "/returning from interrupt_handle_now(%d, info, context)\n", - signal)); + *os_context_pc_addr(&fake_context) = &signal_thread_trampoline; +#ifdef ARCH_HAS_STACK_POINTER /* aka x86(-64) */ + *os_context_sp_addr(&fake_context) = __builtin_frame_address(0); #endif + + signal_handler_callback(interrupt_handlers[signo].lisp, + signo, &fake_info, &fake_context); + return 0; } static void -maybe_now_maybe_later(int signal, siginfo_t *info, void *void_context) +sigprof_handler_trampoline(int signal, siginfo_t *info, void *void_context) { - os_context_t *context = (os_context_t*)void_context; + SAVE_ERRNO(signal,context,void_context); + struct thread *self = arch_os_get_current_thread(); - /* FIXME: See Debian cmucl 2.4.17, and mail from DTC on the CMU CL - * mailing list 23 Oct 1999, for changes in FPU handling at - * interrupt time which should be ported into SBCL. Also see the - * analogous logic at the head of interrupt_handle_now for - * more related FIXME stuff. - * - * For now, we just suppress this code completely. - * #ifdef __linux__ - * SET_FPU_CONTROL_WORD(context->__fpregs_mem.cw); - * #endif */ + /* alloc() is not re-entrant and still uses pseudo atomic (even though + * inline allocation does not). In this case, give up. */ + if (get_pseudo_atomic_atomic(self)) + goto cleanup; - /* see comments at top of code/signal.lisp for what's going on here - * with INTERRUPTS_ENABLED/INTERRUPT_HANDLE_NOW - */ - if (SymbolValue(INTERRUPTS_ENABLED) == NIL) { - - /* FIXME: This code is exactly the same as the code in the - * other leg of the if(..), and should be factored out into - * a shared function. */ - pending_signal = signal; - memcpy(&pending_info, info, sizeof(siginfo_t)); - memcpy(&pending_mask, - os_context_sigmask_addr(context), - sizeof(sigset_t)); - sigaddset_blockable(os_context_sigmask_addr(context)); - SetSymbolValue(INTERRUPT_PENDING, T); - - } else if ( -#ifndef __i386__ - (!foreign_function_call_active) && -#endif - arch_pseudo_atomic_atomic(context)) { - - /* FIXME: It would probably be good to replace these bare - * memcpy(..) calls with calls to cpy_siginfo_t and - * cpy_sigset_t, so that we only have to get the sizeof - * expressions right in one place, and after that static type - * checking takes over. */ - pending_signal = signal; - memcpy(&pending_info, info, sizeof(siginfo_t)); - memcpy(&pending_mask, - os_context_sigmask_addr(context), - sizeof(sigset_t)); - sigaddset_blockable(os_context_sigmask_addr(context)); - - arch_set_pseudo_atomic_interrupted(context); + struct alloc_region tmp = self->alloc_region; + self->alloc_region = self->sprof_alloc_region; + self->sprof_alloc_region = tmp; - } else { - interrupt_handle_now(signal, info, context); - } + interrupt_handle_now_handler(signal, info, void_context); + + /* And we're back. We know that the SIGPROF handler never unwinds + * non-locally, and can simply swap things back: */ + + tmp = self->alloc_region; + self->alloc_region = self->sprof_alloc_region; + self->sprof_alloc_region = tmp; + +cleanup: + ; /* Dear C compiler, it's OK to have a label here. */ + RESTORE_ERRNO; } - -/* - * stuff to detect and handle hitting the GC trigger - */ -#ifndef INTERNAL_GC_TRIGGER -static boolean -gc_trigger_hit(int signal, siginfo_t *info, os_context_t *context) +static void +spawn_signal_thread_handler(int signal, siginfo_t *info, void *void_context) { - if (current_auto_gc_trigger == NULL) - return 0; - else{ - lispobj *badaddr=(lispobj *)arch_get_bad_addr(signal, - info, - context); + SAVE_ERRNO(signal,context,void_context); - return (badaddr >= current_auto_gc_trigger && - badaddr < current_dynamic_space + DYNAMIC_SPACE_SIZE); - } + pthread_attr_t attr; + pthread_t th; + + if (pthread_attr_init(&attr)) + goto lost; + if (pthread_attr_setstacksize(&attr, thread_control_stack_size)) + goto lost; + if (pthread_create(&th, &attr, &signal_thread_trampoline, (void*) signal)) + goto lost; + if (pthread_attr_destroy(&attr)) + goto lost; + + RESTORE_ERRNO; + return; + +lost: + lose("spawn_signal_thread_handler"); } #endif -#ifndef __i386__ -/* This function gets called from the SIGSEGV (for e.g. Linux or - * OpenBSD) or SIGBUS (for e.g. FreeBSD) handler. Here we check - * whether the signal was due to treading on the mprotect()ed zone - - * and if so, arrange for a GC to happen. */ -boolean -interrupt_maybe_gc(int signal, siginfo_t *info, void *void_context) -{ - os_context_t *context=(os_context_t *) void_context; - - if (!foreign_function_call_active -#ifndef INTERNAL_GC_TRIGGER - && gc_trigger_hit(signal, info, context) -#endif - ) { -#ifndef INTERNAL_GC_TRIGGER - clear_auto_gc_trigger(); -#endif - - if (arch_pseudo_atomic_atomic(context)) { - /* don't GC during an atomic operation. Instead, copy the - * signal mask somewhere safe. interrupt_handle_pending - * will detect pending_signal==0 and know to do a GC with the - * signal context instead of calling a Lisp-level handler */ - maybe_gc_pending = 1; - if (pending_signal == 0) { - /* FIXME: This copy-pending_mask-then-sigaddset_blockable - * idiom occurs over and over. It should be factored out - * into a function with a descriptive name. */ - memcpy(&pending_mask, - os_context_sigmask_addr(context), - sizeof(sigset_t)); - sigaddset_blockable(os_context_sigmask_addr(context)); - } - arch_set_pseudo_atomic_interrupted(context); - } - else { - fake_foreign_function_call(context); - funcall0(SymbolFunction(MAYBE_GC)); - undo_fake_foreign_function_call(context); - } - - return 1; - } else { - return 0; - } +static void +unblock_me_trampoline(int signal, siginfo_t *info, void *void_context) +{ + SAVE_ERRNO(signal,context,void_context); + sigset_t unblock; + + sigemptyset(&unblock); + sigaddset(&unblock, signal); + thread_sigmask(SIG_UNBLOCK, &unblock, 0); + interrupt_handle_now(signal, info, context); + RESTORE_ERRNO; } -#endif - -/* - * noise to install handlers - */ -/* - * what low-level signal handlers looked like before - * undoably_install_low_level_interrupt_handler() got involved - */ -struct low_level_signal_handler_state { - int was_modified; - void (*handler)(int, siginfo_t*, void*); -} old_low_level_signal_handler_states[NSIG]; +static void +low_level_unblock_me_trampoline(int signal, siginfo_t *info, void *void_context) +{ + SAVE_ERRNO(signal,context,void_context); + sigset_t unblock; + + sigemptyset(&unblock); + sigaddset(&unblock, signal); + thread_sigmask(SIG_UNBLOCK, &unblock, 0); + (*interrupt_low_level_handlers[signal])(signal, info, context); + RESTORE_ERRNO; +} -void -uninstall_low_level_interrupt_handlers_atexit(void) +static void +low_level_handle_now_handler(int signal, siginfo_t *info, void *void_context) { - int signal; - for (signal = 0; signal < NSIG; ++signal) { - struct low_level_signal_handler_state - *old_low_level_signal_handler_state = - old_low_level_signal_handler_states + signal; - if (old_low_level_signal_handler_state->was_modified) { - struct sigaction sa; - sa.sa_sigaction = old_low_level_signal_handler_state->handler; - sigemptyset(&sa.sa_mask); - sa.sa_flags = SA_SIGINFO | SA_RESTART; - sigaction(signal, &sa, NULL); - } - } + SAVE_ERRNO(signal,context,void_context); + (*interrupt_low_level_handlers[signal])(signal, info, context); + RESTORE_ERRNO; } -/* Undoably install a special low-level handler for signal; or if - * handler is SIG_DFL, remove any special handling for signal. - * - * The "undoably" aspect is because we also arrange with atexit() for - * the handler to be restored to its old value. This is for tidiness: - * it shouldn't matter much ordinarily, but it does remove a window - * where e.g. memory fault signals (SIGSEGV or SIGBUS, which in - * ordinary operation of SBCL are sent to the generational garbage - * collector, then possibly onward to Lisp code) or SIGINT (which is - * ordinarily passed to Lisp code) could otherwise be handled - * bizarrely/brokenly because the Lisp code would try to deal with - * them using machinery (like stream output buffers) which has already - * been dismantled. */ void undoably_install_low_level_interrupt_handler (int signal, - void handler(int, - siginfo_t*, - void*)) + interrupt_handler_t handler) { struct sigaction sa; - struct low_level_signal_handler_state *old_low_level_signal_handler_state = - old_low_level_signal_handler_states + signal; if (0 > signal || signal >= NSIG) { - lose("bad signal number %d", signal); + lose("bad signal number %d\n", signal); } - sa.sa_sigaction = handler; - sigemptyset(&sa.sa_mask); - sigaddset_blockable(&sa.sa_mask); - sa.sa_flags = SA_SIGINFO | SA_RESTART; - - /* In the case of interrupt handlers which are modified more than - * once, we only save the original unmodified copy. */ - if (!old_low_level_signal_handler_state->was_modified) { - struct sigaction *old_handler = - (struct sigaction*) &old_low_level_signal_handler_state->handler; - old_low_level_signal_handler_state->was_modified = 1; - sigaction(signal, &sa, old_handler); - } else { - sigaction(signal, &sa, NULL); + if (ARE_SAME_HANDLER(handler, SIG_DFL)) + sa.sa_sigaction = (void (*)(int, siginfo_t*, void*))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 = low_level_handle_now_handler; + +#ifdef LISP_FEATURE_SB_THRUPTION + /* It's in `deferrable_sigset' so that we block&unblock it properly, + * but we don't actually want to defer it. And if we put it only + * into blockable_sigset, we'd have to special-case it around thread + * creation at least. */ + if (signal == SIGPIPE) + sa.sa_sigaction = low_level_handle_now_handler; +#endif + + 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) { + sa.sa_flags |= SA_ONSTACK; +# ifdef LISP_FEATURE_SB_SAFEPOINT + sigaddset(&sa.sa_mask, SIGRTMIN); + sigaddset(&sa.sa_mask, SIGRTMIN+1); +# endif } +#endif + sigaction(signal, &sa, NULL); interrupt_low_level_handlers[signal] = - (ARE_SAME_HANDLER(handler, SIG_DFL) ? 0 : handler); + (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*)) +uword_t +install_handler(int signal, void handler(int, siginfo_t*, os_context_t*), + int synchronous) { +#ifndef LISP_FEATURE_WIN32 struct sigaction sa; - sigset_t old, new; + sigset_t old; union interrupt_handler oldhandler; FSHOW((stderr, "/entering POSIX install_handler(%d, ..)\n", signal)); - sigemptyset(&new); - sigaddset(&new, signal); - sigprocmask(SIG_BLOCK, &new, &old); - - sigemptyset(&new); - sigaddset_blockable(&new); + block_blockable_signals(0, &old); - FSHOW((stderr, "/interrupt_low_level_handlers[signal]=%d\n", - interrupt_low_level_handlers[signal])); + 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)) { - sa.sa_sigaction = handler; - } else if (sigismember(&new, signal)) { - sa.sa_sigaction = maybe_now_maybe_later; - } else { - sa.sa_sigaction = interrupt_handle_now; - } - - sigemptyset(&sa.sa_mask); - sigaddset_blockable(&sa.sa_mask); - sa.sa_flags = SA_SIGINFO | SA_RESTART; - - sigaction(signal, &sa, NULL); + if (ARE_SAME_HANDLER(handler, SIG_DFL) || + ARE_SAME_HANDLER(handler, SIG_IGN)) + sa.sa_sigaction = (void (*)(int, siginfo_t*, void*))handler; +#ifdef LISP_FEATURE_SB_SAFEPOINT_STRICTLY + else if (signal == SIGPROF) + sa.sa_sigaction = sigprof_handler_trampoline; + else if (!synchronous) + sa.sa_sigaction = spawn_signal_thread_handler; +#endif + else if (sigismember(&deferrable_sigset, signal)) + sa.sa_sigaction = maybe_now_maybe_later; + else if (!sigaction_nodefer_works && + !sigismember(&blockable_sigset, signal)) + sa.sa_sigaction = unblock_me_trampoline; + else + sa.sa_sigaction = interrupt_handle_now_handler; + + sigcopyset(&sa.sa_mask, &blockable_sigset); + sa.sa_flags = SA_SIGINFO | SA_RESTART | + (sigaction_nodefer_works ? SA_NODEFER : 0); + sigaction(signal, &sa, NULL); } oldhandler = interrupt_handlers[signal]; interrupt_handlers[signal].c = handler; - sigprocmask(SIG_SETMASK, &old, 0); + thread_sigmask(SIG_SETMASK, &old, 0); FSHOW((stderr, "/leaving POSIX install_handler(%d, ..)\n", signal)); - return (unsigned long)oldhandler.lisp; + return (uword_t)oldhandler.lisp; +#else + /* Probably-wrong Win32 hack */ + return 0; +#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, os_context_t *context) +{ + lose("SIGABRT received.\n"); } void interrupt_init(void) { +#if !defined(LISP_FEATURE_WIN32) || defined(LISP_FEATURE_SB_THREAD) int i; - SHOW("entering interrupt_init()"); +#ifndef LISP_FEATURE_WIN32 + see_if_sigaction_nodefer_works(); +#endif + sigemptyset(&deferrable_sigset); + sigemptyset(&blockable_sigset); + sigemptyset(&gc_sigset); + sigaddset_deferrable(&deferrable_sigset); + sigaddset_blockable(&blockable_sigset); + sigaddset_gc(&gc_sigset); +#endif - /* Set up for recovery from any installed low-level handlers. */ - atexit(&uninstall_low_level_interrupt_handlers_atexit); - +#ifndef LISP_FEATURE_WIN32 /* Set up high level handler information. */ for (i = 0; i < NSIG; i++) { 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 - * because it works to call the 1-argument form where the - * 3-argument form is expected.) */ - (void (*)(int, siginfo_t*, void*))SIG_DFL; + /* (The cast here blasts away the distinction between + * SA_SIGACTION-style three-argument handlers and + * signal(..)-style one-argument handlers, which is OK + * because it works to call the 1-argument form where the + * 3-argument form is expected.) */ + (void (*)(int, siginfo_t*, os_context_t*))SIG_DFL; } - + undoably_install_low_level_interrupt_handler(SIGABRT, sigabrt_handler); +#endif SHOW("returning from interrupt_init()"); } + +#ifndef LISP_FEATURE_WIN32 +int +siginfo_code(siginfo_t *info) +{ + return info->si_code; +} +os_vm_address_t current_memory_fault_address; + +void +lisp_memory_fault_error(os_context_t *context, os_vm_address_t addr) +{ + /* FIXME: This is lossy: if we get another memory fault (eg. from + * another thread) before lisp has read this, we lose the information. + * However, since this is mostly informative, we'll live with that for + * now -- some address is better then no address in this case. + */ + current_memory_fault_address = addr; + /* To allow debugging memory faults in signal handlers and such. */ + corruption_warning_and_maybe_lose("Memory fault at %x (pc=%p, sp=%p)", + addr, + *os_context_pc_addr(context), +#ifdef ARCH_HAS_STACK_POINTER + *os_context_sp_addr(context) +#else + 0 +#endif + ); + unblock_signals_in_context_and_maybe_warn(context); +#ifdef LISP_FEATURE_C_STACK_IS_CONTROL_STACK + arrange_return_to_lisp_function(context, + StaticSymbolFunction(MEMORY_FAULT_ERROR)); +#else + funcall0(StaticSymbolFunction(MEMORY_FAULT_ERROR)); +#endif +} +#endif + +static void +unhandled_trap_error(os_context_t *context) +{ + lispobj context_sap; + fake_foreign_function_call(context); +#ifndef LISP_FEATURE_SB_SAFEPOINT + unblock_gc_signals(0, 0); +#endif + context_sap = alloc_sap(context); +#if !defined(LISP_FEATURE_WIN32) || defined(LISP_FEATURE_SB_THREAD) + thread_sigmask(SIG_SETMASK, os_context_sigmask_addr(context), 0); +#endif + funcall1(StaticSymbolFunction(UNHANDLED_TRAP_ERROR), context_sap); + lose("UNHANDLED-TRAP-ERROR fell through"); +} + +/* Common logic for trapping instructions. How we actually handle each + * case is highly architecture dependent, but the overall shape is + * this. */ +void +handle_trap(os_context_t *context, int trap) +{ + switch(trap) { +#if !(defined(LISP_FEATURE_WIN32) && defined(LISP_FEATURE_SB_THREAD)) + case trap_PendingInterrupt: + FSHOW((stderr, "/\n")); + arch_skip_instruction(context); + interrupt_handle_pending(context); + break; +#endif + case trap_Error: + case trap_Cerror: + FSHOW((stderr, "/\n", trap)); + interrupt_internal_error(context, trap==trap_Cerror); + break; + case trap_Breakpoint: + arch_handle_breakpoint(context); + break; + case trap_FunEndBreakpoint: + arch_handle_fun_end_breakpoint(context); + break; +#ifdef trap_AfterBreakpoint + case trap_AfterBreakpoint: + arch_handle_after_breakpoint(context); + break; +#endif +#ifdef trap_SingleStepAround + case trap_SingleStepAround: + case trap_SingleStepBefore: + arch_handle_single_step_trap(context, trap); + break; +#endif +#ifdef trap_GlobalSafepoint + case trap_GlobalSafepoint: + fake_foreign_function_call(context); + thread_in_lisp_raised(context); + undo_fake_foreign_function_call(context); + arch_skip_instruction(context); + break; + case trap_CspSafepoint: + fake_foreign_function_call(context); + thread_in_safety_transition(context); + undo_fake_foreign_function_call(context); + arch_skip_instruction(context); + break; +#endif +#if defined(LISP_FEATURE_SPARC) && defined(LISP_FEATURE_GENCGC) + case trap_Allocation: + arch_handle_allocation_trap(context); + arch_skip_instruction(context); + break; +#endif + case trap_Halt: + fake_foreign_function_call(context); + lose("%%PRIMITIVE HALT called; the party is over.\n"); + default: + unhandled_trap_error(context); + } +}