X-Git-Url: http://repo.macrolet.net/gitweb/?a=blobdiff_plain;f=src%2Fruntime%2Finterrupt.c;h=be105e5d86a23a9689d80b8d3df2f18af1bb3dae;hb=961c6bf2eda5d492d5dbb7e275fe4e0931f7adf8;hp=5ee65ee34af6cdcad503a7ca08ea837512f4df50;hpb=bd455348d39bee562296741689882dcb97c46ba3;p=sbcl.git diff --git a/src/runtime/interrupt.c b/src/runtime/interrupt.c index 5ee65ee..be105e5 100644 --- a/src/runtime/interrupt.c +++ b/src/runtime/interrupt.c @@ -59,29 +59,223 @@ #include "globals.h" #include "lispregs.h" #include "validate.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; - -static void run_deferred_handler(struct interrupt_data *data, void *v_context); #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); -boolean interrupt_maybe_gc_int(int signal, siginfo_t *info, void *v_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); + } +} + +/* 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); @@ -89,111 +283,350 @@ sigaddset_deferrable(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); +} + +void +sigaddset_blockable(sigset_t *sigset) +{ + sigaddset_deferrable(sigset); + sigaddset_gc(sigset); +} -#if !((defined(LISP_FEATURE_DARWIN) || defined(LISP_FEATURE_FREEBSD)) && defined(LISP_FEATURE_SB_THREAD)) - sigaddset(s, SIGUSR1); - sigaddset(s, SIGUSR2); +void +sigaddset_gc(sigset_t *sigset) +{ +#ifdef THREADS_USING_GCSIGNAL + sigaddset(sigset,SIG_STOP_FOR_GC); #endif +} + +/* initialized in interrupt_init */ +sigset_t deferrable_sigset; +sigset_t blockable_sigset; +sigset_t gc_sigset; -#ifdef LISP_FEATURE_SB_THREAD - sigaddset(s, SIG_INTERRUPT_THREAD); #endif + +#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 -sigaddset_blockable(sigset_t *s) +check_deferrables_unblocked_or_lose(sigset_t *sigset) { - sigaddset_deferrable(s); -#ifdef LISP_FEATURE_SB_THREAD -#ifdef SIG_RESUME_FROM_GC - sigaddset(s, SIG_RESUME_FROM_GC); +#if !defined(LISP_FEATURE_WIN32) || defined(LISP_FEATURE_SB_THREAD) + if (deferrables_blocked_p(sigset)) + lose("deferrables blocked\n"); #endif - sigaddset(s, SIG_STOP_FOR_GC); +} + +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 } -/* initialized in interrupt_init */ -static sigset_t deferrable_sigset; -static sigset_t blockable_sigset; +#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_blocked_or_lose() +check_blockables_unblocked_or_lose(sigset_t *sigset) { -#ifndef LISP_FEATURE_WIN32 - /* Get the current sigmask, by blocking the empty set. */ - sigset_t empty,current; - int i; - sigemptyset(&empty); - thread_sigmask(SIG_BLOCK, &empty, ¤t); - for(i = 1; i < NSIG; i++) { - if (sigismember(&blockable_sigset, i) && !sigismember(¤t, i)) - lose("blockable signal %d not blocked\n",i); - } +#if !defined(LISP_FEATURE_WIN32) || defined(LISP_FEATURE_SB_THREAD) + if (blockables_blocked_p(sigset)) + lose("blockables blocked\n"); #endif } -inline static void -check_interrupts_enabled_or_lose(os_context_t *context) +void +check_blockables_blocked_or_lose(sigset_t *sigset) { - struct thread *thread=arch_os_get_current_thread(); - if (SymbolValue(INTERRUPTS_ENABLED,thread) == NIL) - lose("interrupts not enabled\n"); - if ( -#if !defined(LISP_FEATURE_X86) && !defined(LISP_FEATURE_X86_64) - (!foreign_function_call_active) && +#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 - arch_pseudo_atomic_atomic(context)) - lose ("in pseudo atomic section\n"); } -/* 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_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 -#ifndef LISP_FEATURE_WIN32 -static void (*interrupt_low_level_handlers[NSIG]) (int, siginfo_t*, void*); +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 -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 +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 -reset_signal_mask(void) +block_deferrable_signals(sigset_t *where, sigset_t *old) { -#ifndef LISP_FEATURE_WIN32 - sigset_t new; - sigemptyset(&new); - thread_sigmask(SIG_SETMASK,&new,0); +#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 -block_blockable_signals(void) +unblock_gc_signals(sigset_t *where, sigset_t *old) { #ifndef LISP_FEATURE_WIN32 - thread_sigmask(SIG_BLOCK, &blockable_sigset, 0); + 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 -block_deferrable_signals(void) +maybe_save_gc_mask_and_block_deferrables(sigset_t *sigset) { #ifndef LISP_FEATURE_WIN32 - thread_sigmask(SIG_BLOCK, &deferrable_sigset, 0); + 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 @@ -208,23 +641,23 @@ build_fake_control_stack_frames(struct thread *th,os_context_t *context) /* Build a fake stack frame or frames */ - current_control_frame_pointer = - (lispobj *)(unsigned long) + access_control_frame_pointer(th) = + (lispobj *)(uword_t) (*os_context_register_addr(context, reg_CSP)); - if ((lispobj *)(unsigned long) + if ((lispobj *)(uword_t) (*os_context_register_addr(context, reg_CFP)) - == current_control_frame_pointer) { + == 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. */ - current_control_frame_pointer[0] = + access_control_frame_pointer(th)[0] = *os_context_register_addr(context, reg_OCFP); - current_control_frame_pointer[1] = + access_control_frame_pointer(th)[1] = *os_context_register_addr(context, reg_LRA); - current_control_frame_pointer += 8; + access_control_frame_pointer(th) += 8; /* Build our frame on top of it. */ oldcont = (lispobj)(*os_context_register_addr(context, reg_CFP)); } @@ -243,11 +676,11 @@ build_fake_control_stack_frames(struct thread *th,os_context_t *context) oldcont = (lispobj)(*os_context_register_addr(context, reg_CFP)); } - current_control_stack_pointer = current_control_frame_pointer + 8; + access_control_stack_pointer(th) = access_control_frame_pointer(th) + 8; - current_control_frame_pointer[0] = oldcont; - current_control_frame_pointer[1] = NIL; - current_control_frame_pointer[2] = + 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 } @@ -261,24 +694,34 @@ fake_foreign_function_call(os_context_t *context) struct thread *thread=arch_os_get_current_thread(); /* context_index incrementing must not be interrupted */ - check_blockables_blocked_or_lose(); + 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 *)(unsigned long) + (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) - if ((long)dynamic_space_free_pointer & 1) { +/* 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 - current_binding_stack_pointer = - (lispobj *)(unsigned long) - (*os_context_register_addr(context, reg_BSP)); + set_binding_stack_pointer(thread, + *os_context_register_addr(context, reg_BSP)); #endif build_fake_control_stack_frames(thread,context); @@ -297,8 +740,12 @@ fake_foreign_function_call(os_context_t *context) thread->interrupt_contexts[context_index] = context; - /* no longer in Lisp now */ - foreign_function_call_active = 1; +#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, @@ -309,32 +756,42 @@ undo_fake_foreign_function_call(os_context_t *context) { struct thread *thread=arch_os_get_current_thread(); /* Block all blockable signals. */ - block_blockable_signals(); + block_blockable_signals(0, 0); - /* going back into Lisp */ - foreign_function_call_active = 0; + foreign_function_call_active_p(thread) = 0; /* Undo dynamic binding of FREE_INTERRUPT_CONTEXT_INDEX */ unbind(thread); -#ifdef reg_ALLOC +#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) = - (unsigned long) dynamic_space_free_pointer + (uword_t) dynamic_space_free_pointer | (*os_context_register_addr(context, reg_ALLOC) & LOWTAG_MASK); /* - ((unsigned long)(*os_context_register_addr(context, reg_ALLOC)) & ~LOWTAG_MASK) - | ((unsigned long) dynamic_space_free_pointer & 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(int signal, siginfo_t *info, os_context_t *context, - boolean continuable) +interrupt_internal_error(os_context_t *context, boolean continuable) { lispobj context_sap; @@ -349,20 +806,33 @@ interrupt_internal_error(int signal, siginfo_t *info, os_context_t *context, /* 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); -#ifndef LISP_FEATURE_WIN32 +#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"); -#ifdef QSHOW +#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(SymbolFunction(INTERNAL_ERROR), context_sap, + funcall2(StaticSymbolFunction(INTERNAL_ERROR), context_sap, continuable ? T : NIL); undo_fake_foreign_function_call(context); /* blocks signals again */ @@ -370,131 +840,218 @@ interrupt_internal_error(int signal, siginfo_t *info, os_context_t *context, 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) { - struct thread *thread; - struct interrupt_data *data; + /* 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(); - thread=arch_os_get_current_thread(); - data=thread->interrupt_data; - - /* 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); + 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) { -#ifdef LISP_FEATURE_SB_THREAD + 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) { - /* another thread has already initiated a gc, this attempt - * might as well be cancelled */ - SetSymbolValue(GC_PENDING,NIL,thread); - SetSymbolValue(STOP_FOR_GC_PENDING,NIL,thread); + /* 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. */ - interrupt_maybe_gc_int(0,NULL,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(); - } - /* we may be here only to do the gc stuff, if interrupts are - * enabled run the pending handler */ - if (!((SymbolValue(INTERRUPTS_ENABLED,thread) == NIL) || - ( -#if !defined(LISP_FEATURE_X86) && !defined(LISP_FEATURE_X86_64) - (!foreign_function_call_active) && -#endif - arch_pseudo_atomic_atomic(context)))) { - - /* There may be no pending handler, because it was only a gc - * that had to be executed or because pseudo atomic triggered - * twice for a single interrupt. For the interested reader, - * that may happen if an interrupt hits after the interrupted - * flag is cleared but before pseduo-atomic is set and a - * pseudo atomic is interrupted in that interrupt. */ - if (data->pending_handler) { - - /* If we're here as the result of a pseudo-atomic as opposed - * to WITHOUT-INTERRUPTS, then INTERRUPT_PENDING is already - * NIL, because maybe_defer_handler sets - * PSEUDO_ATOMIC_INTERRUPTED only if interrupts are enabled.*/ - SetSymbolValue(INTERRUPT_PENDING, NIL,thread); + 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 - /* restore the saved signal mask from the original signal (the - * one that interrupted us during the critical section) into the - * os_context for the signal we're currently in the handler for. - * This should ensure that when we return from the handler the - * blocked signals are unblocked */ - sigcopyset(os_context_sigmask_addr(context), &data->pending_mask); - - sigemptyset(&data->pending_mask); -#endif - /* This will break on sparc linux: the deferred handler really wants - * to be called with a void_context */ - run_deferred_handler(data,(void *)context); - } + /* 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")); } -/* - * the two main signal handlers: - * interrupt_handle_now(..) - * maybe_now_maybe_later(..) - * - * to which we have added interrupt_handle_now_handler(..). Why? - * Well, mostly because 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; however, we only - * want to do this when we first hit the handler, and not when - * interrupt_handle_now(..) is being called from some other handler - * (when the fixup will already have been done). -- CSR, 2002-07-23 - */ void -interrupt_handle_now(int signal, siginfo_t *info, void *void_context) +interrupt_handle_now(int signal, siginfo_t *info, os_context_t *context) { - os_context_t *context = (os_context_t*)void_context; -#if !defined(LISP_FEATURE_X86) && !defined(LISP_FEATURE_X86_64) boolean were_in_lisp; -#endif union interrupt_handler handler; - check_blockables_blocked_or_lose(); - + check_blockables_blocked_or_lose(0); -#ifndef LISP_FEATURE_WIN32 +#if !defined(LISP_FEATURE_WIN32) || defined(LISP_FEATURE_SB_THREAD) if (sigismember(&deferrable_sigset,signal)) check_interrupts_enabled_or_lose(context); #endif -#if defined(LISP_FEATURE_LINUX) || defined(RESTORE_FP_CONTROL_FROM_CONTEXT) - /* 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. */ - os_restore_fp_control(context); -#endif - - handler = interrupt_handlers[signal]; if (ARE_SAME_HANDLER(handler.c, SIG_IGN)) { return; } -#if !defined(LISP_FEATURE_X86) && !defined(LISP_FEATURE_X86_64) - were_in_lisp = !foreign_function_call_active; + were_in_lisp = !foreign_function_call_active_p(arch_os_get_current_thread()); if (were_in_lisp) -#endif { fake_foreign_function_call(context); } @@ -526,43 +1083,39 @@ interrupt_handle_now(int signal, siginfo_t *info, void *void_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); - /* 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); - } + lispobj info_sap, context_sap; + +#ifndef LISP_FEATURE_SB_SAFEPOINT + /* Leave deferrable signals blocked, the handler itself will + * allow signals again when it sees fit. */ + unblock_gc_signals(0, 0); +#else + WITH_GC_AT_SAFEPOINTS_ONLY() #endif + { // the block is needed for WITH_GC_AT_SAFEPOINTS_ONLY() to work + context_sap = alloc_sap(context); + info_sap = alloc_sap(info); - FSHOW_SIGNAL((stderr,"/calling Lisp-level handler\n")); + FSHOW_SIGNAL((stderr,"/calling Lisp-level handler\n")); - funcall3(handler.lisp, - make_fixnum(signal), - info_sap, - context_sap); + 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")); -#ifndef LISP_FEATURE_WIN32 +#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 - - (*handler.c)(signal, info, void_context); } -#if !defined(LISP_FEATURE_X86) && !defined(LISP_FEATURE_X86_64) if (were_in_lisp) -#endif { undo_fake_foreign_function_call(context); /* block signals again */ } @@ -578,15 +1131,18 @@ interrupt_handle_now(int signal, siginfo_t *info, void *void_context) * already; we're just doing the Lisp-level processing now that we * put off then */ static void -run_deferred_handler(struct interrupt_data *data, void *v_context) { +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*, void*)=data->pending_handler; + void (*pending_handler) (int, siginfo_t*, os_context_t*) = + data->pending_handler; data->pending_handler=0; - (*pending_handler)(data->pending_signal,&(data->pending_info), v_context); + FSHOW_SIGNAL((stderr, "/running deferred handler %p\n", pending_handler)); + (*pending_handler)(data->pending_signal,&(data->pending_info), context); } #ifndef LISP_FEATURE_WIN32 @@ -596,49 +1152,49 @@ maybe_defer_handler(void *handler, struct interrupt_data *data, { struct thread *thread=arch_os_get_current_thread(); - check_blockables_blocked_or_lose(); + 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) { - store_signal_data_for_later(data,handler,signal,info,context); - SetSymbolValue(INTERRUPT_PENDING, T,thread); + if ((SymbolValue(INTERRUPTS_ENABLED,thread) == NIL) || + in_leaving_without_gcing_race_p(thread)) { FSHOW_SIGNAL((stderr, - "/maybe_defer_handler(%x,%d),thread=%lu: deferred\n", + "/maybe_defer_handler(%x,%d): deferred (RACE=%d)\n", (unsigned int)handler,signal, - (unsigned long)thread->os_thread)); + 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 + /* 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 ( -#if !defined(LISP_FEATURE_X86) && !defined(LISP_FEATURE_X86_64) - /* FIXME: this foreign_function_call_active test is dubious at - * best. If a foreign call is made in a pseudo atomic section - * (?) or more likely a pseudo atomic section is in a foreign - * call then an interrupt is executed immediately. Maybe it - * has to do with C code not maintaining pseudo atomic - * properly. MG - 2005-08-10 */ - (!foreign_function_call_active) && -#endif - arch_pseudo_atomic_atomic(context)) { + 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); - FSHOW_SIGNAL((stderr, - "/maybe_defer_handler(%x,%d),thread=%lu: deferred(PA)\n", - (unsigned int)handler,signal, - (unsigned long)thread->os_thread)); + check_interrupt_context_or_lose(context); return 1; } FSHOW_SIGNAL((stderr, - "/maybe_defer_handler(%x,%d),thread=%lu: not deferred\n", - (unsigned int)handler,signal, - (unsigned long)thread->os_thread)); + "/maybe_defer_handler(%x,%d): not deferred\n", + (unsigned int)handler,signal)); return 0; } @@ -657,174 +1213,157 @@ store_signal_data_for_later (struct interrupt_data *data, void *handler, if(info) memcpy(&(data->pending_info), info, sizeof(siginfo_t)); - FSHOW_SIGNAL((stderr, "/store_signal_data_for_later: signal: %d\n", signal)); + 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 maybe_now_maybe_later(int signal, siginfo_t *info, void *void_context) { - os_context_t *context = arch_os_get_context(&void_context); - - struct thread *thread; - struct interrupt_data *data; - - thread=arch_os_get_current_thread(); - data=thread->interrupt_data; - -#if defined(LISP_FEATURE_LINUX) || defined(RESTORE_FP_CONTROL_FROM_CONTEXT) - os_restore_fp_control(context); -#endif - - if(maybe_defer_handler(interrupt_handle_now,data,signal,info,context)) - return; - interrupt_handle_now(signal, info, context); -#ifdef LISP_FEATURE_DARWIN - /* Work around G5 bug */ - DARWIN_FIX_CONTEXT(context); -#endif + 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, void *void_context) +low_level_interrupt_handle_now(int signal, siginfo_t *info, + os_context_t *context) { - os_context_t *context = (os_context_t*)void_context; - -#if defined(LISP_FEATURE_LINUX) || defined(RESTORE_FP_CONTROL_FROM_CONTEXT) - os_restore_fp_control(context); -#endif - - check_blockables_blocked_or_lose(); + /* 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, void_context); -#ifdef LISP_FEATURE_DARWIN - /* Work around G5 bug */ - DARWIN_FIX_CONTEXT(context); -#endif + (*interrupt_low_level_handlers[signal])(signal, info, context); + /* No Darwin context fixage needed, caller does that. */ } static void low_level_maybe_now_maybe_later(int signal, siginfo_t *info, void *void_context) { - os_context_t *context = arch_os_get_context(&void_context); - struct thread *thread; - struct interrupt_data *data; - - thread=arch_os_get_current_thread(); - data=thread->interrupt_data; - -#if defined(LISP_FEATURE_LINUX) || defined(RESTORE_FP_CONTROL_FROM_CONTEXT) - os_restore_fp_control(context); -#endif - - if(maybe_defer_handler(low_level_interrupt_handle_now,data, - signal,info,context)) - return; - low_level_interrupt_handle_now(signal, info, context); -#ifdef LISP_FEATURE_DARWIN - /* Work around G5 bug */ - DARWIN_FIX_CONTEXT(context); -#endif + 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 -#ifdef LISP_FEATURE_SB_THREAD +#ifdef THREADS_USING_GCSIGNAL +/* 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) +sig_stop_for_gc_handler(int signal, siginfo_t *info, os_context_t *context) { - os_context_t *context = arch_os_get_context(&void_context); - struct thread *thread=arch_os_get_current_thread(); - sigset_t ss; + boolean was_in_lisp; - if ((arch_pseudo_atomic_atomic(context) || - SymbolValue(GC_INHIBIT,thread) != NIL)) { + /* 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); - if (SymbolValue(GC_INHIBIT,thread) == NIL) - arch_set_pseudo_atomic_interrupted(context); - FSHOW_SIGNAL((stderr,"thread=%lu sig_stop_for_gc deferred\n", - thread->os_thread)); - } else { + 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; + } + + 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); + } - sigfillset(&ss); /* Block everything. */ - thread_sigmask(SIG_BLOCK,&ss,0); + /* 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; + } - if(thread->state!=STATE_RUNNING) { - lose("sig_stop_for_gc_handler: wrong thread state: %ld\n", - fixnum_value(thread->state)); - } - thread->state=STATE_SUSPENDED; - FSHOW_SIGNAL((stderr,"thread=%lu suspended\n",thread->os_thread)); + if(thread_state(thread)!=STATE_RUNNING) { + lose("sig_stop_for_gc_handler: wrong thread state: %ld\n", + fixnum_value(thread->state)); + } -#if defined(SIG_RESUME_FROM_GC) - sigemptyset(&ss); sigaddset(&ss,SIG_RESUME_FROM_GC); -#else - sigemptyset(&ss); sigaddset(&ss,SIG_STOP_FOR_GC); -#endif + set_thread_state(thread,STATE_STOPPED); + FSHOW_SIGNAL((stderr,"suspended\n")); - /* 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 + /* 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(); - FSHOW_SIGNAL((stderr,"thread=%lu resumed\n",thread->os_thread)); - if(thread->state!=STATE_RUNNING) { - lose("sig_stop_for_gc_handler: wrong thread state on wakeup: %ld\n", - fixnum_value(thread->state)); - } + wait_for_thread_state_change(thread, STATE_STOPPED); + FSHOW_SIGNAL((stderr,"resumed\n")); + + if(thread_state(thread)!=STATE_RUNNING) { + lose("sig_stop_for_gc_handler: wrong thread state on wakeup: %ld\n", + fixnum_value(thread_state(thread))); + } + if (was_in_lisp) { undo_fake_foreign_function_call(context); } } + #endif void interrupt_handle_now_handler(int signal, siginfo_t *info, void *void_context) { - os_context_t *context = arch_os_get_context(&void_context); - interrupt_handle_now(signal, info, context); -#ifdef LISP_FEATURE_DARWIN - DARWIN_FIX_CONTEXT(context); + SAVE_ERRNO(signal,context,void_context); +#ifndef LISP_FEATURE_WIN32 + if ((signal == SIGILL) || (signal == SIGBUS) +#ifndef LISP_FEATURE_LINUX + || (signal == SIGEMT) #endif -} - -/* - * stuff to detect and handle hitting the GC trigger - */ - -#ifndef LISP_FEATURE_GENCGC -/* since GENCGC has its own way to record trigger */ -static boolean -gc_trigger_hit(int signal, siginfo_t *info, os_context_t *context) -{ - if (current_auto_gc_trigger == NULL) - return 0; - else{ - void *badaddr=arch_get_bad_addr(signal,info,context); - return (badaddr >= (void *)current_auto_gc_trigger && - badaddr <((void *)current_dynamic_space + dynamic_space_size)); - } -} + ) + corruption_warning_and_maybe_lose("Signal %d received", signal); #endif + interrupt_handle_now(signal, info, context); + RESTORE_ERRNO; +} /* manipulate the signal context and stack such that when the handler * returns, it will call function instead of whatever it was doing @@ -838,9 +1377,16 @@ extern int *context_eflags_addr(os_context_t *context); 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 -arrange_return_to_lisp_function(os_context_t *context, lispobj function) +arrange_return_to_c_function(os_context_t *context, + call_into_lisp_lookalike funptr, + lispobj function) { +#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); @@ -849,8 +1395,14 @@ arrange_return_to_lisp_function(os_context_t *context, lispobj function) /* Build a stack frame showing `interrupted' so that the * user's backtrace makes (as much) sense (as usual) */ - /* FIXME: what about restoring fp state? */ - /* FIXME: what about restoring errno? */ + /* 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 @@ -908,8 +1460,10 @@ arrange_return_to_lisp_function(os_context_t *context, lispobj function) *(register_save_area + 7) = *os_context_register_addr(context,reg_EAX); *(register_save_area + 8) = *context_eflags_addr(context); - *os_context_pc_addr(context) = call_into_lisp_tramp; - *os_context_register_addr(context,reg_ECX) = register_save_area; + *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: */ @@ -937,6 +1491,7 @@ arrange_return_to_lisp_function(os_context_t *context, lispobj function) #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; @@ -971,7 +1526,7 @@ arrange_return_to_lisp_function(os_context_t *context, lispobj function) #ifdef LISP_FEATURE_X86 #if !defined(LISP_FEATURE_DARWIN) - *os_context_pc_addr(context) = (os_context_register_t)call_into_lisp; + *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__ @@ -983,7 +1538,7 @@ arrange_return_to_lisp_function(os_context_t *context, lispobj function) #endif /* LISP_FEATURE_DARWIN */ #elif defined(LISP_FEATURE_X86_64) - *os_context_pc_addr(context) = (os_context_register_t)call_into_lisp; + *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); @@ -995,7 +1550,7 @@ arrange_return_to_lisp_function(os_context_t *context, lispobj function) *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)current_control_frame_pointer; + (os_context_register_t)(unsigned long)access_control_frame_pointer(th); #endif #ifdef ARCH_HAS_NPC_REGISTER *os_context_npc_addr(context) = @@ -1005,24 +1560,22 @@ arrange_return_to_lisp_function(os_context_t *context, lispobj function) *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)); } -#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) +arrange_return_to_lisp_function(os_context_t *context, lispobj function) { - os_context_t *context = (os_context_t*)arch_os_get_context(&v_context); - - /* let the handler enable interrupts again when it sees fit */ - sigaddset_deferrable(os_context_sigmask_addr(context)); - arrange_return_to_lisp_function(context, SymbolFunction(RUN_INTERRUPTION)); -} - +#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 +} +// x86-64 has an undefined_alien_function tramp in x86-64-assem.S +#ifndef LISP_FEATURE_X86_64 /* 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, @@ -1030,8 +1583,41 @@ interrupt_thread_handler(int num, siginfo_t *info, void *v_context) * functions and variables. */ void -undefined_alien_function() { - funcall0(SymbolFunction(UNDEFINED_ALIEN_FUNCTION_ERROR)); +undefined_alien_function(void) +{ + funcall0(StaticSymbolFunction(UNDEFINED_ALIEN_FUN_ERROR)); +} +#endif + +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"); +} + +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); + } +} + +void lower_control_stack_guard_page(void) +{ + lower_thread_control_stack_guard_page(arch_os_get_current_thread()); } boolean @@ -1039,19 +1625,26 @@ handle_guard_page_triggered(os_context_t *context,os_vm_address_t addr) { struct thread *th=arch_os_get_current_thread(); - /* note the os_context hackery here. When the signal handler returns, - * it won't go back to what it was doing ... */ - if(addr >= CONTROL_STACK_GUARD_PAGE(th) && - addr < CONTROL_STACK_GUARD_PAGE(th) + os_vm_page_size) { + 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. */ - protect_control_stack_guard_page(0); - protect_control_stack_return_guard_page(1); - + 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 arrange_return_to_lisp_function - (context, SymbolFunction(CONTROL_STACK_EXHAUSTED_ERROR)); + (context, StaticSymbolFunction(CONTROL_STACK_EXHAUSTED_ERROR)); return 1; } else if(addr >= CONTROL_STACK_RETURN_GUARD_PAGE(th) && @@ -1060,112 +1653,67 @@ handle_guard_page_triggered(os_context_t *context,os_vm_address_t addr) * unprotect this one. This works even if we somehow missed * the return-guard-page, and hit it on our way to new * exhaustion instead. */ - protect_control_stack_guard_page(1); - protect_control_stack_return_guard_page(0); + 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 >= undefined_alien_address && - addr < undefined_alien_address + os_vm_page_size) { + 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, SymbolFunction(UNDEFINED_ALIEN_VARIABLE_ERROR)); + (context, StaticSymbolFunction(BINDING_STACK_EXHAUSTED_ERROR)); return 1; } - else return 0; -} - -#ifndef LISP_FEATURE_GENCGC -/* This function gets called from the SIGSEGV (for e.g. Linux, NetBSD, & - * 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. */ -extern unsigned long bytes_consed_between_gcs; /* gc-common.c */ - -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 && gc_trigger_hit(signal, info, context)){ - struct thread *thread=arch_os_get_current_thread(); - clear_auto_gc_trigger(); - /* Don't flood the system with interrupts if the need to gc is - * already noted. This can happen for example when SUB-GC - * allocates or after a gc triggered in a WITHOUT-GCING. */ - if (SymbolValue(GC_PENDING,thread) == NIL) { - if (SymbolValue(GC_INHIBIT,thread) == NIL) { - if (arch_pseudo_atomic_atomic(context)) { - /* set things up so that GC happens when we finish - * the PA section */ - SetSymbolValue(GC_PENDING,T,thread); - arch_set_pseudo_atomic_interrupted(context); - } else { - interrupt_maybe_gc_int(signal,info,void_context); - } - } else { - SetSymbolValue(GC_PENDING,T,thread); - } - } + 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; } - return 0; -} - -#endif - -/* this is also used by gencgc, in alloc() */ -boolean -interrupt_maybe_gc_int(int signal, siginfo_t *info, void *void_context) -{ - os_context_t *context=(os_context_t *) void_context; -#ifndef LISP_FEATURE_WIN32 - struct thread *thread=arch_os_get_current_thread(); -#endif - - fake_foreign_function_call(context); - - /* SUB-GC may return without GCing if *GC-INHIBIT* is set, in - * which case we will be running with no gc trigger barrier - * thing for a while. But it shouldn't be long until the end - * of WITHOUT-GCING. - * - * FIXME: It would be good to protect the end of dynamic space - * and signal a storage condition from there. - */ - - /* Restore the signal mask from the interrupted context before - * calling into Lisp if interrupts are enabled. Why not always? - * - * Suppose there is a WITHOUT-INTERRUPTS block far, far out. If an - * interrupt hits while in SUB-GC, it is deferred and the - * os_context_sigmask of that interrupt is set to block further - * deferrable interrupts (until the first one is - * handled). Unfortunately, that context refers to this place and - * when we return from here the signals will not be blocked. - * - * A kludgy alternative is to propagate the sigmask change to the - * outer context. - */ -#ifndef LISP_FEATURE_WIN32 - if(SymbolValue(INTERRUPTS_ENABLED,thread)!=NIL) - thread_sigmask(SIG_SETMASK, os_context_sigmask_addr(context), 0); -#ifdef LISP_FEATURE_SB_THREAD - else { - sigset_t new; - sigemptyset(&new); -#if defined(SIG_RESUME_FROM_GC) - sigaddset(&new,SIG_RESUME_FROM_GC); -#endif - sigaddset(&new,SIG_STOP_FOR_GC); - thread_sigmask(SIG_UNBLOCK,&new,0); + else if(addr >= ALIEN_STACK_HARD_GUARD_PAGE(th) && + addr < ALIEN_STACK_HARD_GUARD_PAGE(th) + os_vm_page_size) { + lose("Alien stack exhausted"); } -#endif -#endif - funcall0(SymbolFunction(SUB_GC)); - - undo_fake_foreign_function_call(context); - return 1; + 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 @@ -1193,10 +1741,9 @@ static volatile int sigaction_nodefer_works = -1; static void sigaction_nodefer_test_handler(int signal, siginfo_t *info, void *void_context) { - sigset_t empty, current; + sigset_t current; int i; - sigemptyset(&empty); - thread_sigmask(SIG_BLOCK, &empty, ¤t); + 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 @@ -1213,7 +1760,7 @@ sigaction_nodefer_test_handler(int signal, siginfo_t *info, void *void_context) } static void -see_if_sigaction_nodefer_works() +see_if_sigaction_nodefer_works(void) { struct sigaction sa, old_sa; @@ -1237,33 +1784,126 @@ see_if_sigaction_nodefer_works() #undef SA_NODEFER_TEST_BLOCK_SIGNAL #undef SA_NODEFER_TEST_KILL_SIGNAL +#if defined(LISP_FEATURE_SB_SAFEPOINT_STRICTLY) && !defined(LISP_FEATURE_WIN32) + +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 + + 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 + + *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 +sigprof_handler_trampoline(int signal, siginfo_t *info, void *void_context) +{ + SAVE_ERRNO(signal,context,void_context); + struct thread *self = arch_os_get_current_thread(); + + /* 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; + + struct alloc_region tmp = self->alloc_region; + self->alloc_region = self->sprof_alloc_region; + self->sprof_alloc_region = tmp; + + 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; +} + +static void +spawn_signal_thread_handler(int signal, siginfo_t *info, void *void_context) +{ + SAVE_ERRNO(signal,context,void_context); + + 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 + 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_handler(signal, info, void_context); + interrupt_handle_now(signal, info, context); + RESTORE_ERRNO; } 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, void_context); + (*interrupt_low_level_handlers[signal])(signal, info, context); + RESTORE_ERRNO; +} + +static void +low_level_handle_now_handler(int signal, siginfo_t *info, void *void_context) +{ + SAVE_ERRNO(signal,context,void_context); + (*interrupt_low_level_handlers[signal])(signal, info, context); + RESTORE_ERRNO; } void undoably_install_low_level_interrupt_handler (int signal, - void handler(int, - siginfo_t*, - void*)) + interrupt_handler_t handler) { struct sigaction sa; @@ -1272,34 +1912,35 @@ undoably_install_low_level_interrupt_handler (int signal, } if (ARE_SAME_HANDLER(handler, SIG_DFL)) - sa.sa_sigaction = handler; + sa.sa_sigaction = (void (*)(int, siginfo_t*, void*))handler; else if (sigismember(&deferrable_sigset,signal)) sa.sa_sigaction = low_level_maybe_now_maybe_later; - /* The use of a trampoline appears to break the - arch_os_get_context() workaround for SPARC/Linux. For now, - don't use the trampoline (and so be vulnerable to the problems - that SA_NODEFER is meant to solve. */ -#if !(defined(LISP_FEATURE_SPARC) && defined(LISP_FEATURE_LINUX)) else if (!sigaction_nodefer_works && !sigismember(&blockable_sigset, signal)) sa.sa_sigaction = low_level_unblock_me_trampoline; -#endif else - sa.sa_sigaction = handler; + 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) -#ifdef SIG_MEMORY_FAULT2 - || (signal==SIG_MEMORY_FAULT2) -#endif -#ifdef SIG_INTERRUPT_THREAD - || (signal==SIG_INTERRUPT_THREAD) -#endif - ) + 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); @@ -1309,26 +1950,31 @@ undoably_install_low_level_interrupt_handler (int signal, #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); - thread_sigmask(SIG_BLOCK, &new, &old); + block_blockable_signals(0, &old); 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; + 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 && @@ -1350,25 +1996,39 @@ install_handler(int signal, void handler(int, siginfo_t*, void*)) 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 -interrupt_init() +sigabrt_handler(int signal, siginfo_t *info, os_context_t *context) { -#ifndef LISP_FEATURE_WIN32 + 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 +#ifndef LISP_FEATURE_WIN32 /* Set up high level handler information. */ for (i = 0; i < NSIG; i++) { interrupt_handlers[i].c = @@ -1377,11 +2037,11 @@ interrupt_init() * 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; + (void (*)(int, siginfo_t*, os_context_t*))SIG_DFL; } - - SHOW("returning from interrupt_init()"); + undoably_install_low_level_interrupt_handler(SIGABRT, sigabrt_handler); #endif + SHOW("returning from interrupt_init()"); } #ifndef LISP_FEATURE_WIN32 @@ -1396,11 +2056,107 @@ 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 the information. + * 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; - arrange_return_to_lisp_function(context, SymbolFunction(MEMORY_FAULT_ERROR)); + /* 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); + } +}