X-Git-Url: http://repo.macrolet.net/gitweb/?a=blobdiff_plain;f=src%2Fruntime%2Finterrupt.c;h=882e2bb322e64bda821c0c90dadee262911685f5;hb=bf40ae88bc289fd765a33861cc4bc0853ed483ba;hp=fdbbb9dd7167b2d3626fe26722439c9d7a5660b3;hpb=1b56edad1bf47547bbcd3b98c809b6f933ba937e;p=sbcl.git diff --git a/src/runtime/interrupt.c b/src/runtime/interrupt.c index fdbbb9d..882e2bb 100644 --- a/src/runtime/interrupt.c +++ b/src/runtime/interrupt.c @@ -22,7 +22,7 @@ * 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. + * 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, @@ -36,117 +36,628 @@ * 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 - * + * 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" -void run_deferred_handler(struct interrupt_data *data, void *v_context) ; -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); +/* 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; -extern lispobj all_threads_lock; -extern volatile int countdown_to_gc; +#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 -/* - * This is a workaround for some slightly silly Linux/GNU Libc - * behaviour: glibc defines sigset_t to support 1024 signals, which is - * more than the kernel. This is usually not a problem, but becomes - * one when we want to save a signal mask from a ucontext, and restore - * it later into another ucontext: the ucontext is allocated on the - * stack by the kernel, so copying a libc-sized sigset_t into it will - * overflow and cause other data on the stack to be corrupted */ +/* 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); + } +} -#define REAL_SIGSET_SIZE_BYTES ((NSIG/8)) +/* 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_blockable(sigset_t *s) +void +sigaddset_deferrable(sigset_t *s) { sigaddset(s, SIGHUP); sigaddset(s, SIGINT); + sigaddset(s, SIGTERM); sigaddset(s, SIGQUIT); sigaddset(s, SIGPIPE); sigaddset(s, SIGALRM); sigaddset(s, SIGURG); - sigaddset(s, SIGFPE); 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); -#ifdef LISP_FEATURE_SB_THREAD - /* don't block STOP_FOR_GC, we need to be able to interrupt threads - * for GC purposes even when they are blocked on queues etc */ - sigaddset(s, SIG_INTERRUPT_THREAD); +} + +void +sigaddset_blockable(sigset_t *sigset) +{ + sigaddset_deferrable(sigset); + sigaddset_gc(sigset); +} + +void +sigaddset_gc(sigset_t *sigset) +{ +#ifdef THREADS_USING_GCSIGNAL + sigaddset(sigset,SIG_STOP_FOR_GC); #endif } -/* 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; +/* initialized in interrupt_init */ +sigset_t deferrable_sigset; +sigset_t blockable_sigset; +sigset_t gc_sigset; + +#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 -struct interrupt_data * global_interrupt_data; +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 */ -void +static void build_fake_control_stack_frames(struct thread *th,os_context_t *context) { -#ifndef LISP_FEATURE_X86 - +#ifndef LISP_FEATURE_C_STACK_IS_CONTROL_STACK + lispobj oldcont; /* Build a fake stack frame or frames */ - 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) { + 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) { + == 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; + 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)); } @@ -165,34 +676,52 @@ 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] = - (lispobj)(*os_context_register_addr(context, reg_CODE)); + 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 *)(*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); + (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 - current_binding_stack_pointer = - (lispobj *)(*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); @@ -200,221 +729,398 @@ fake_foreign_function_call(os_context_t *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)); - + fixnum_value(SymbolValue(FREE_INTERRUPT_CONTEXT_INDEX,thread)); + if (context_index >= MAX_INTERRUPTS) { - lose("maximum interrupt nesting depth (%d) exceeded", MAX_INTERRUPTS); + lose("maximum interrupt nesting depth (%d) exceeded\n", MAX_INTERRUPTS); } bind_variable(FREE_INTERRUPT_CONTEXT_INDEX, - make_fixnum(context_index + 1),thread); + make_fixnum(context_index + 1),thread); 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, - * the usual signal mask will be restored from the context when the 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. */ - sigset_t block; - sigemptyset(&block); - sigaddset_blockable(&block); - sigprocmask(SIG_BLOCK, &block, 0); + 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); + /* + ((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 = 0; + lispobj context_sap; fake_foreign_function_call(context); - /* Allocate the SAP object while the interrupts are still - * disabled. */ - if (internal_errors_enabled) { - context_sap = alloc_sap(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"); } - sigprocmask(SIG_SETMASK, os_context_sigmask_addr(context), 0); + /* 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 (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); +#if !defined(LISP_FEATURE_WIN32) || defined(LISP_FEATURE_SB_THREAD) + thread_sigmask(SIG_SETMASK, os_context_sigmask_addr(context), 0); #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); + +#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) { - 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")); - thread=arch_os_get_current_thread(); - data=thread->interrupt_data; - SetSymbolValue(INTERRUPT_PENDING, NIL,thread); + 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 - /* 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 */ + 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."); + } - memcpy(os_context_sigmask_addr(context), &data->pending_mask, - REAL_SIGSET_SIZE_BYTES); + 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); + } - sigemptyset(&data->pending_mask); - /* This will break on sparc linux: the deferred handler really wants - * to be called with a void_context */ - run_deferred_handler(data,(void *)context); +#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")); } -/* - * 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; - struct thread *thread=arch_os_get_current_thread(); -#ifndef LISP_FEATURE_X86 boolean were_in_lisp; -#endif union interrupt_handler handler; -#ifdef LISP_FEATURE_LINUX - /* 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 = thread->interrupt_data->interrupt_handlers[signal]; + 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; + return; } - -#ifndef LISP_FEATURE_X86 - 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); } -#ifdef QSHOW_SIGNALS - FSHOW((stderr, - "/entering interrupt_handle_now(%d, info, context)\n", - signal)); -#endif + FSHOW_SIGNAL((stderr, + "/entering interrupt_handle_now(%d, info, context)\n", + signal)); if (ARE_SAME_HANDLER(handler.c, SIG_DFL)) { - /* This can happen if someone tries to ignore or default one - * of the signals we need for runtime support, and the runtime - * support decides to pass on it. */ - lose("no handler for signal %d in interrupt_handle_now(..)", signal); + /* 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 */ + /* 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 */ - - lispobj info_sap,context_sap = alloc_sap(context); + * 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); - /* Allow signals again. */ - sigprocmask(SIG_SETMASK, os_context_sigmask_addr(context), 0); -#ifdef QSHOW_SIGNALS - SHOW("calling Lisp-level handler"); -#endif + 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); + make_fixnum(signal), + info_sap, + context_sap); } else { + /* This cannot happen in sane circumstances. */ -#ifdef QSHOW_SIGNALS - SHOW("calling C-level handler"); -#endif + FSHOW_SIGNAL((stderr,"/calling C-level handler\n")); +#if !defined(LISP_FEATURE_WIN32) || defined(LISP_FEATURE_SB_THREAD) /* Allow signals again. */ - sigprocmask(SIG_SETMASK, os_context_sigmask_addr(context), 0); - - (*handler.c)(signal, info, void_context); + thread_sigmask(SIG_SETMASK, os_context_sigmask_addr(context), 0); + (*handler.c)(signal, info, context); +#endif } -#ifndef LISP_FEATURE_X86 if (were_in_lisp) -#endif { - undo_fake_foreign_function_call(context); + undo_fake_foreign_function_call(context); /* block signals again */ } -#ifdef QSHOW_SIGNALS - FSHOW((stderr, - "/returning from interrupt_handle_now(%d, info, context)\n", - signal)); -#endif + FSHOW_SIGNAL((stderr, + "/returning from interrupt_handle_now(%d, info, context)\n", + signal)); } /* This is called at the end of a critical section if the indications @@ -422,382 +1128,1030 @@ interrupt_handle_now(int signal, siginfo_t *info, void *void_context) * far as C or the kernel is concerned we dealt with the signal * already; we're just doing the Lisp-level processing now that we * put off then */ - -void -run_deferred_handler(struct interrupt_data *data, void *v_context) { - (*(data->pending_handler)) - (data->pending_signal,&(data->pending_info), v_context); +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) + int signal, siginfo_t *info, os_context_t *context) { struct thread *thread=arch_os_get_current_thread(); - if (SymbolValue(INTERRUPTS_ENABLED,thread) == NIL) { - store_signal_data_for_later(data,handler,signal,info,context); + + 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); - return 1; - } - /* a slightly confusing test. arch_pseudo_atomic_atomic() doesn't + 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 ( -#ifndef LISP_FEATURE_X86 - (!foreign_function_call_active) && -#endif - arch_pseudo_atomic_atomic(context)) { - store_signal_data_for_later(data,handler,signal,info,context); - arch_set_pseudo_atomic_interrupted(context); - return 1; + 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) + 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)); - 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 */ - sigemptyset(&(data->pending_mask)); - memcpy(&(data->pending_mask), - os_context_sigmask_addr(context), - REAL_SIGSET_SIZE_BYTES); - sigaddset_blockable(os_context_sigmask_addr(context)); - } else { - /* this is also called from gencgc alloc(), in which case - * there has been no signal and is therefore no context. */ - sigset_t new; - sigemptyset(&new); - sigaddset_blockable(&new); - sigprocmask(SIG_BLOCK,&new,&(data->pending_mask)); - } -} + 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) { - os_context_t *context = arch_os_get_context(&void_context); - struct thread *thread=arch_os_get_current_thread(); - struct interrupt_data *data=thread->interrupt_data; -#ifdef LISP_FEATURE_LINUX - os_restore_fp_control(context); -#endif - if(maybe_defer_handler(interrupt_handle_now,data, - signal,info,context)) - return; - interrupt_handle_now(signal, info, 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. */ +} + +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 + +#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(); - struct interrupt_data *data=thread->interrupt_data; - sigset_t block; + 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; + } + + 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); + } - if(maybe_defer_handler(sig_stop_for_gc_handler,data, - signal,info,context)){ - return; + /* 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; } - sigemptyset(&block); - sigaddset_blockable(&block); - sigprocmask(SIG_BLOCK, &block, 0); - /* need the context stored so it can have registers scavenged */ - fake_foreign_function_call(context); + if(thread_state(thread)!=STATE_RUNNING) { + lose("sig_stop_for_gc_handler: wrong thread state: %ld\n", + fixnum_value(thread->state)); + } + + set_thread_state(thread,STATE_STOPPED); + FSHOW_SIGNAL((stderr,"suspended\n")); + + /* 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(); + + wait_for_thread_state_change(thread, STATE_STOPPED); + FSHOW_SIGNAL((stderr,"resumed\n")); - get_spinlock(&all_threads_lock,thread->pid); - countdown_to_gc--; - release_spinlock(&all_threads_lock); - kill(getpid(),SIGSTOP); + if(thread_state(thread)!=STATE_RUNNING) { + lose("sig_stop_for_gc_handler: wrong thread state on wakeup: %ld\n", + fixnum_value(thread_state(thread))); + } - undo_fake_foreign_function_call(context); + 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); + 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; } -/* - * 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)); - } -} -#endif - /* 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); -void arrange_return_to_lisp_function(os_context_t *context, lispobj function) +extern void call_into_lisp_tramp(void); + +void +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); - char *code = &(((struct simple_fun *) fun)->code); - + void *code = &(((struct simple_fun *) fun)->code); +#endif + /* 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. We shortcut this: fake the stack that call_into_lisp - * would see, then arrange to have it called directly. post_signal_tramp - * is the second half of this function + * 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 */ + u32 *sp=(u32 *)*os_context_register_addr(context,reg_ESP); - *(sp-14) = post_signal_tramp; /* return address for call_into_lisp */ - *(sp-13) = function; /* args for call_into_lisp : function*/ - *(sp-12) = 0; /* arg array */ - *(sp-11) = 0; /* no. args */ +#if defined(LISP_FEATURE_DARWIN) + u32 *register_save_area = (u32 *)os_validate(0, 0x40); + + 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)); + + /* 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-10)=*os_context_register_addr(context,reg_EDI); - *(sp-9)=*os_context_register_addr(context,reg_ESI); - /* this gets overwritten again before it's used, anyway */ - *(sp-8)=*os_context_register_addr(context,reg_EBP); - *(sp-7)=0 ; /* POPAD doesn't set ESP, but expects a gap for it anyway */ - *(sp-6)=*os_context_register_addr(context,reg_EBX); - - *(sp-5)=*os_context_register_addr(context,reg_EDX); - *(sp-4)=*os_context_register_addr(context,reg_ECX); - *(sp-3)=*os_context_register_addr(context,reg_EAX); + *(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); -#else +#endif + +#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 #ifdef LISP_FEATURE_X86 - *os_context_pc_addr(context) = call_into_lisp; - *os_context_register_addr(context,reg_ECX) = 0; - *os_context_register_addr(context,reg_EBP) = sp-2; - *os_context_register_addr(context,reg_ESP) = sp-14; + +#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) = code; - *os_context_register_addr(context,reg_NARGS) = 0; - *os_context_register_addr(context,reg_LIP) = code; - *os_context_register_addr(context,reg_CFP) = - current_control_frame_pointer; + *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 #ifdef ARCH_HAS_NPC_REGISTER *os_context_npc_addr(context) = - 4 + *os_context_pc_addr(context); + 4 + *os_context_pc_addr(context); #endif #ifdef LISP_FEATURE_SPARC - *os_context_register_addr(context,reg_CODE) = - fun + FUN_POINTER_LOWTAG; + *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 -void handle_rt_signal(int num, siginfo_t *info, void *v_context) +void +arrange_return_to_lisp_function(os_context_t *context, lispobj function) +{ +#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 +} + +/* 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)); +} + +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) { - os_context_t *context = (os_context_t*)arch_os_get_context(&v_context); struct thread *th=arch_os_get_current_thread(); - struct interrupt_data *data= - th ? th->interrupt_data : global_interrupt_data; - if(maybe_defer_handler(handle_rt_signal,data,num,info,context)){ - return ; + if (th->control_stack_guard_page_protected == NIL) { + reset_thread_control_stack_guard_page(th); } - arrange_return_to_lisp_function(context,info->si_value.sival_int); } -#endif -boolean handle_control_stack_guard_triggered(os_context_t *context,void *addr){ +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(); - /* note the os_context hackery here. When the signal handler returns, - * it won't go back to what it was doing ... */ - if(addr>=(void *)CONTROL_STACK_GUARD_PAGE(th) && - addr<(void *)(CONTROL_STACK_GUARD_PAGE(th)+os_vm_page_size)) { - /* we hit the end of the control stack. disable protection - * temporarily so the error handler has some headroom */ - protect_control_stack_guard_page(th->pid,0L); - - arrange_return_to_lisp_function - (context, SymbolFunction(CONTROL_STACK_EXHAUSTED_ERROR)); - return 1; + + 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 + 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 + */ + +#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; -#ifndef LISP_FEATURE_GENCGC -/* 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. */ -extern unsigned long bytes_consed_between_gcs; /* gc-common.c */ +#define SA_NODEFER_TEST_BLOCK_SIGNAL SIGABRT +#define SA_NODEFER_TEST_KILL_SIGNAL SIGUSR1 -boolean -interrupt_maybe_gc(int signal, siginfo_t *info, void *void_context) +static void +sigaction_nodefer_test_handler(int signal, siginfo_t *info, void *void_context) { - os_context_t *context=(os_context_t *) void_context; - struct thread *th=arch_os_get_current_thread(); - struct interrupt_data *data= - th ? th->interrupt_data : global_interrupt_data; + 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; +} - if(!foreign_function_call_active && gc_trigger_hit(signal, info, context)){ - clear_auto_gc_trigger(); - if(!maybe_defer_handler - (interrupt_maybe_gc_int,data,signal,info,void_context)) - interrupt_maybe_gc_int(signal,info,void_context); - return 1; +static void +see_if_sigaction_nodefer_works(void) +{ + struct sigaction sa, old_sa; + + sa.sa_flags = SA_SIGINFO | SA_NODEFER; + sa.sa_sigaction = sigaction_nodefer_test_handler; + sigemptyset(&sa.sa_mask); + sigaddset(&sa.sa_mask, 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); +} + +#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 -/* this is also used by from gencgc.c alloc() */ -boolean -interrupt_maybe_gc_int(int signal, siginfo_t *info, void *void_context) +static void +unblock_me_trampoline(int signal, siginfo_t *info, void *void_context) { - os_context_t *context=(os_context_t *) void_context; - 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. */ - funcall0(SymbolFunction(SUB_GC)); - undo_fake_foreign_function_call(context); - return 1; + 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; } - -/* - * noise to install handlers - */ +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; +} + +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; - struct thread *th=arch_os_get_current_thread(); - struct interrupt_data *data= - th ? th->interrupt_data : global_interrupt_data; if (0 > signal || signal >= NSIG) { - lose("bad signal number %d", signal); + lose("bad signal number %d\n", signal); } - sa.sa_sigaction = handler; - sigemptyset(&sa.sa_mask); - sigaddset_blockable(&sa.sa_mask); - sa.sa_flags = SA_SIGINFO | SA_RESTART; -#ifdef LISP_FEATURE_C_STACK_IS_CONTROL_STACK - if((signal==SIG_MEMORY_FAULT) -#ifdef SIG_INTERRUPT_THREAD - || (signal==SIG_INTERRUPT_THREAD) + 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 - ) - sa.sa_flags|= SA_ONSTACK; + + 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); - data->interrupt_low_level_handlers[signal] = - (ARE_SAME_HANDLER(handler, SIG_DFL) ? 0 : handler); + interrupt_low_level_handlers[signal] = + (ARE_SAME_HANDLER(handler, SIG_DFL) ? 0 : handler); } +#endif /* This is called from Lisp. */ -unsigned long -install_handler(int signal, void handler(int, siginfo_t*, void*)) +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; - struct thread *th=arch_os_get_current_thread(); - struct interrupt_data *data= - th ? th->interrupt_data : global_interrupt_data; FSHOW((stderr, "/entering POSIX install_handler(%d, ..)\n", signal)); - sigemptyset(&new); - sigaddset(&new, signal); - sigprocmask(SIG_BLOCK, &new, &old); - - sigemptyset(&new); - sigaddset_blockable(&new); - - FSHOW((stderr, "/interrupt_low_level_handlers[signal]=%d\n", - interrupt_low_level_handlers[signal])); - if (data->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_handler; - } - - sigemptyset(&sa.sa_mask); - sigaddset_blockable(&sa.sa_mask); - sa.sa_flags = SA_SIGINFO | SA_RESTART; - sigaction(signal, &sa, NULL); + 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 = (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 = data->interrupt_handlers[signal]; - data->interrupt_handlers[signal].c = handler; + 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() +interrupt_init(void) { +#if !defined(LISP_FEATURE_WIN32) || defined(LISP_FEATURE_SB_THREAD) int i; SHOW("entering interrupt_init()"); - global_interrupt_data=calloc(sizeof(struct interrupt_data), 1); +#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++) { - global_interrupt_data->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; + 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*, 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); + } +}