*
* - WHN 20000728, dan 20010128 */
+#include "sbcl.h"
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <signal.h>
#include <sys/types.h>
+#ifndef LISP_FEATURE_WIN32
#include <sys/wait.h>
+#endif
#include <errno.h>
-#include "sbcl.h"
#include "runtime.h"
#include "arch.h"
#include "os.h"
#include "globals.h"
#include "lispregs.h"
#include "validate.h"
-#include "monitor.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"
+/* 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
+/* 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(context,void_context) \
+ { \
+ int _saved_errno = errno; \
+ RESTORE_FP_CONTROL_WORD(context,void_context); \
+ {
+
+#define RESTORE_ERRNO \
+ } \
+ errno = _saved_errno; \
+ }
-void run_deferred_handler(struct interrupt_data *data, void *v_context) ;
+static void run_deferred_handler(struct interrupt_data *data,
+ os_context_t *context);
+#ifndef LISP_FEATURE_WIN32
static void store_signal_data_for_later (struct interrupt_data *data,
void *handler, int signal,
siginfo_t *info,
os_context_t *context);
-boolean interrupt_maybe_gc_int(int signal, siginfo_t *info, void *v_context);
-void sigaddset_deferrable(sigset_t *s)
+static void
+fill_current_sigmask(sigset_t *sigset)
+{
+ /* Get the current sigmask, by blocking the empty set. */
+ sigset_t empty;
+ sigemptyset(&empty);
+ thread_sigmask(SIG_BLOCK, &empty, sigset);
+}
+
+void
+sigaddset_deferrable(sigset_t *s)
{
sigaddset(s, SIGHUP);
sigaddset(s, SIGINT);
+ sigaddset(s, SIGTERM);
sigaddset(s, SIGQUIT);
sigaddset(s, SIGPIPE);
sigaddset(s, SIGALRM);
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);
+}
+
+void
+sigdelset_deferrable(sigset_t *s)
+{
+ sigdelset(s, SIGHUP);
+ sigdelset(s, SIGINT);
+ sigdelset(s, SIGQUIT);
+ sigdelset(s, SIGPIPE);
+ sigdelset(s, SIGALRM);
+ sigdelset(s, SIGURG);
+ sigdelset(s, SIGTSTP);
+ sigdelset(s, SIGCHLD);
+ sigdelset(s, SIGIO);
+#ifndef LISP_FEATURE_HPUX
+ sigdelset(s, SIGXCPU);
+ sigdelset(s, SIGXFSZ);
+#endif
+ sigdelset(s, SIGVTALRM);
+ sigdelset(s, SIGPROF);
+ sigdelset(s, SIGWINCH);
+}
+
+void
+sigaddset_blockable(sigset_t *sigset)
+{
+ sigaddset_deferrable(sigset);
+ sigaddset_gc(sigset);
+}
+
+void
+sigaddset_gc(sigset_t *sigset)
+{
#ifdef LISP_FEATURE_SB_THREAD
- sigaddset(s, SIG_INTERRUPT_THREAD);
+ sigaddset(sigset,SIG_STOP_FOR_GC);
#endif
}
-void sigaddset_blockable(sigset_t *s)
+void
+sigdelset_gc(sigset_t *sigset)
{
- sigaddset_deferrable(s);
#ifdef LISP_FEATURE_SB_THREAD
- sigaddset(s, SIG_STOP_FOR_GC);
+ sigdelset(sigset,SIG_STOP_FOR_GC);
#endif
}
/* initialized in interrupt_init */
-static sigset_t deferrable_sigset;
-static sigset_t blockable_sigset;
+sigset_t deferrable_sigset;
+sigset_t blockable_sigset;
+sigset_t gc_sigset;
+#endif
-inline static void check_blockables_blocked_or_lose()
+boolean
+deferrables_blocked_in_sigset_p(sigset_t *sigset)
{
- /* Get the current sigmask, by blocking the empty set. */
- sigset_t empty,current;
+#if !defined(LISP_FEATURE_WIN32)
int i;
- sigemptyset(&empty);
- thread_sigmask(SIG_BLOCK, &empty, ¤t);
- for(i=0;i<NSIG;i++) {
+ for(i = 1; i < NSIG; i++) {
+ if (sigismember(&deferrable_sigset, i) && sigismember(sigset, i))
+ return 1;
+ }
+#endif
+ return 0;
+}
+
+void
+check_deferrables_unblocked_in_sigset_or_lose(sigset_t *sigset)
+{
+#if !defined(LISP_FEATURE_WIN32)
+ int i;
+ for(i = 1; i < NSIG; i++) {
+ if (sigismember(&deferrable_sigset, i) && sigismember(sigset, i))
+ lose("deferrable signal %d blocked\n",i);
+ }
+#endif
+}
+
+void
+check_deferrables_blocked_in_sigset_or_lose(sigset_t *sigset)
+{
+#if !defined(LISP_FEATURE_WIN32)
+ int i;
+ for(i = 1; i < NSIG; i++) {
+ if (sigismember(&deferrable_sigset, i) && !sigismember(sigset, i))
+ lose("deferrable signal %d not blocked\n",i);
+ }
+#endif
+}
+
+void
+check_deferrables_unblocked_or_lose(void)
+{
+#if !defined(LISP_FEATURE_WIN32)
+ sigset_t current;
+ fill_current_sigmask(¤t);
+ check_deferrables_unblocked_in_sigset_or_lose(¤t);
+#endif
+}
+
+void
+check_deferrables_blocked_or_lose(void)
+{
+#if !defined(LISP_FEATURE_WIN32)
+ sigset_t current;
+ fill_current_sigmask(¤t);
+ check_deferrables_blocked_in_sigset_or_lose(¤t);
+#endif
+}
+
+void
+check_blockables_blocked_or_lose(void)
+{
+#if !defined(LISP_FEATURE_WIN32)
+ sigset_t current;
+ int i;
+ fill_current_sigmask(¤t);
+ for(i = 1; i < NSIG; i++) {
if (sigismember(&blockable_sigset, i) && !sigismember(¤t, i))
- lose("blockable signal %d not blocked",i);
+ lose("blockable signal %d not blocked\n",i);
}
+#endif
+}
+
+void
+check_gc_signals_unblocked_in_sigset_or_lose(sigset_t *sigset)
+{
+#if !defined(LISP_FEATURE_WIN32)
+ int i;
+ for(i = 1; i < NSIG; i++) {
+ if (sigismember(&gc_sigset, i) && sigismember(sigset, i))
+ lose("gc signal %d blocked\n",i);
+ }
+#endif
}
-inline static void check_interrupts_enabled_or_lose(os_context_t *context)
+void
+check_gc_signals_unblocked_or_lose(void)
+{
+#if !defined(LISP_FEATURE_WIN32)
+ sigset_t current;
+ fill_current_sigmask(¤t);
+ check_gc_signals_unblocked_in_sigset_or_lose(¤t);
+#endif
+}
+
+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");
- if (
-#if !defined(LISP_FEATURE_X86) && !defined(LISP_FEATURE_X86_64)
- (!foreign_function_call_active) &&
+ 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.*/
+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. */
+ thread_sigmask(SIG_BLOCK, &blockable_sigset, &oldset);
+#ifndef LISP_FEATURE_SB_THREAD
+ /* With threads a SIG_STOP_FOR_GC and a normal GC may also want to
+ * block. */
+ if (data->gc_blocked_deferrables)
+ lose("gc_blocked_deferrables already true\n");
+#endif
+ if ((!data->pending_handler) &&
+ (!data->gc_blocked_deferrables)) {
+ FSHOW_SIGNAL((stderr,"/setting gc_blocked_deferrables\n"));
+ data->gc_blocked_deferrables = 1;
+ if (sigset) {
+ /* This is the sigmask of some context. */
+ sigcopyset(&data->pending_mask, sigset);
+ sigaddset_deferrable(sigset);
+ thread_sigmask(SIG_SETMASK,&oldset,0);
+ return;
+ } else {
+ /* Operating on the current sigmask. Save oldset and
+ * unblock gc signals. In the end, this is equivalent to
+ * blocking the deferrables. */
+ sigcopyset(&data->pending_mask, &oldset);
+ unblock_gc_signals();
+ return;
+ }
+ }
+ thread_sigmask(SIG_SETMASK,&oldset,0);
+#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)
+{
+#ifndef LISP_FEATURE_WIN32
+ struct thread *thread = arch_os_get_current_thread();
+ struct interrupt_data *data = thread->interrupt_data;
+ int interrupt_deferred_p = (data->pending_handler != 0);
+ int interrupt_pending = (SymbolValue(INTERRUPT_PENDING,thread) != NIL);
+ sigset_t *sigset = os_context_sigmask_addr(context);
+ /* On PPC pseudo_atomic_interrupted is cleared when coming out of
+ * handle_allocation_trap. */
+#if defined(LISP_FEATURE_GENCGC) && !defined(LISP_FEATURE_PPC)
+ int interrupts_enabled = (SymbolValue(INTERRUPTS_ENABLED,thread) != NIL);
+ int gc_inhibit = (SymbolValue(GC_INHIBIT,thread) != NIL);
+ int gc_pending = (SymbolValue(GC_PENDING,thread) == T);
+ int pseudo_atomic_interrupted = get_pseudo_atomic_interrupted(thread);
+ int in_race_p = in_leaving_without_gcing_race_p(thread);
+ /* In the time window between leaving the *INTERRUPTS-ENABLED* NIL
+ * section and trapping, a SIG_STOP_FOR_GC would see the next
+ * check fail, for this reason sig_stop_for_gc handler does not
+ * call this function. */
+ if (interrupt_deferred_p) {
+ if (!(!interrupts_enabled || pseudo_atomic_interrupted || in_race_p))
+ lose("Stray deferred interrupt.\n");
+ }
+ if (gc_pending)
+ if (!(pseudo_atomic_interrupted || gc_inhibit || in_race_p))
+ lose("GC_PENDING, but why?\n");
+#if defined(LISP_FEATURE_SB_THREAD)
+ {
+ int stop_for_gc_pending =
+ (SymbolValue(STOP_FOR_GC_PENDING,thread) != NIL);
+ if (stop_for_gc_pending)
+ if (!(pseudo_atomic_interrupted || gc_inhibit || in_race_p))
+ lose("STOP_FOR_GC_PENDING, but why?\n");
+ }
+#endif
+#endif
+ if (interrupt_pending && !interrupt_deferred_p)
+ lose("INTERRUPT_PENDING but not pending handler.\n");
+ if ((data->gc_blocked_deferrables) && interrupt_pending)
+ lose("gc_blocked_deferrables and interrupt pending\n.");
+ if (data->gc_blocked_deferrables)
+ check_deferrables_blocked_in_sigset_or_lose(sigset);
+ if (interrupt_pending || interrupt_deferred_p)
+ check_deferrables_blocked_in_sigset_or_lose(sigset);
+ else {
+ check_deferrables_unblocked_in_sigset_or_lose(sigset);
+ /* If deferrables are unblocked then we are open to signals
+ * that run lisp code. */
+ check_gc_signals_unblocked_in_sigset_or_lose(sigset);
+ }
#endif
- arch_pseudo_atomic_atomic(context))
- lose ("in pseudo atomic section");
}
/* When we catch an internal error, should we pass it back to Lisp to
* becomes 'yes'.) */
boolean internal_errors_enabled = 0;
-static void (*interrupt_low_level_handlers[NSIG]) (int, siginfo_t*, void*);
+#ifndef LISP_FEATURE_WIN32
+static
+void (*interrupt_low_level_handlers[NSIG]) (int, siginfo_t*, os_context_t*);
+#endif
union interrupt_handler interrupt_handlers[NSIG];
-/* At the toplevel repl we routinely call this function. The signal
- * mask ought to be clear anyway most of the time, but may be non-zero
- * if we were interrupted e.g. while waiting for a queue. */
+void
+block_blockable_signals(void)
+{
+#ifndef LISP_FEATURE_WIN32
+ thread_sigmask(SIG_BLOCK, &blockable_sigset, 0);
+#endif
+}
-void reset_signal_mask(void)
+void
+block_deferrable_signals(void)
{
- sigset_t new;
- sigemptyset(&new);
- thread_sigmask(SIG_SETMASK,&new,0);
+#ifndef LISP_FEATURE_WIN32
+ thread_sigmask(SIG_BLOCK, &deferrable_sigset, 0);
+#endif
}
-void block_blockable_signals(void)
+void
+unblock_deferrable_signals_in_sigset(sigset_t *sigset)
{
- sigset_t block;
- sigcopyset(&block, &blockable_sigset);
- thread_sigmask(SIG_BLOCK, &block, 0);
+#ifndef LISP_FEATURE_WIN32
+ if (interrupt_handler_pending_p())
+ lose("unblock_deferrable_signals_in_sigset: losing proposition\n");
+ check_gc_signals_unblocked_in_sigset_or_lose(sigset);
+ sigdelset_deferrable(sigset);
+#endif
+}
+
+void
+unblock_deferrable_signals(void)
+{
+#ifndef LISP_FEATURE_WIN32
+ if (interrupt_handler_pending_p())
+ lose("unblock_deferrable_signals: losing proposition\n");
+ check_gc_signals_unblocked_or_lose();
+ thread_sigmask(SIG_UNBLOCK, &deferrable_sigset, 0);
+#endif
+}
+
+void
+unblock_gc_signals(void)
+{
+#if defined(LISP_FEATURE_SB_THREAD) && !defined(LISP_FEATURE_WIN32)
+ thread_sigmask(SIG_UNBLOCK,&gc_sigset,0);
+#endif
+}
+
+void
+unblock_signals_in_context_and_maybe_warn(os_context_t *context)
+{
+#ifndef LISP_FEATURE_WIN32
+ int i, oops=0;
+ sigset_t *sigset=os_context_sigmask_addr(context);
+ for(i = 1; i < NSIG; i++) {
+ if (sigismember(&gc_sigset, i) && sigismember(sigset, i)) {
+ if (!oops) {
+ fprintf(stderr,
+"Enabling blocked gc signals to allow returning to Lisp without risking\n\
+gc deadlocks. Since GC signals are only blocked in signal handlers when \n\
+they are not safe to interrupt at all, this is a pretty severe occurrence.\n");
+ }
+ oops=1;
+ }
+ }
+ sigdelset_gc(sigset);
+ if (!interrupt_handler_pending_p()) {
+ unblock_deferrable_signals_in_sigset(sigset);
+ }
+#endif
}
\f
#endif
}
+/* Stores the context for gc to scavange and builds fake stack
+ * frames. */
void
fake_foreign_function_call(os_context_t *context)
{
dynamic_space_free_pointer =
(lispobj *)(unsigned long)
(*os_context_register_addr(context, reg_ALLOC));
-#if defined(LISP_FEATURE_ALPHA)
+/* fprintf(stderr,"dynamic_space_free_pointer: %p\n", */
+/* dynamic_space_free_pointer); */
+#if defined(LISP_FEATURE_ALPHA) || defined(LISP_FEATURE_MIPS)
if ((long)dynamic_space_free_pointer & 1) {
- lose("dead in fake_foreign_function_call, context = %x", context);
+ 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 ((long)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
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,
thread->interrupt_contexts[context_index] = context;
- /* no longer in Lisp now */
+#ifdef FOREIGN_FUNCTION_CALL_FLAG
foreign_function_call_active = 1;
+#endif
}
/* blocks all blockable signals. If you are calling from a signal handler,
* the usual signal mask will be restored from the context when the handler
* finishes. Otherwise, be careful */
-
void
undo_fake_foreign_function_call(os_context_t *context)
{
/* Block all blockable signals. */
block_blockable_signals();
- /* going back into Lisp */
+#ifdef FOREIGN_FUNCTION_CALL_FLAG
foreign_function_call_active = 0;
+#endif
/* Undo dynamic binding of FREE_INTERRUPT_CONTEXT_INDEX */
unbind(thread);
#ifdef reg_ALLOC
/* Put the dynamic space free pointer back into the context. */
*os_context_register_addr(context, reg_ALLOC) =
- (unsigned long) dynamic_space_free_pointer;
+ (unsigned long) 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);
+ */
#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);
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");
+ lose("internal error too early in init, can't recover\n");
}
/* Allocate the SAP object while the interrupts are still
* disabled. */
+ unblock_gc_signals();
context_sap = alloc_sap(context);
+#ifndef LISP_FEATURE_WIN32
thread_sigmask(SIG_SETMASK, os_context_sigmask_addr(context), 0);
+#endif
+
+#if defined(LISP_FEATURE_LINUX) && defined(LISP_FEATURE_MIPS)
+ /* Workaround for blocked SIGTRAP. */
+ {
+ sigset_t newset;
+ sigemptyset(&newset);
+ sigaddset(&newset, SIGTRAP);
+ thread_sigmask(SIG_UNBLOCK, &newset, 0);
+ }
+#endif
SHOW("in interrupt_internal_error");
#ifdef QSHOW
* 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 */
- if (continuable) {
+ 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). */
+
+ /* Win32 only needs to handle the GC cases (for now?) */
+
+ 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 pseduo 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 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;
+ }
if (SymbolValue(GC_INHIBIT,thread)==NIL) {
+ void *original_pending_handler = data->pending_handler;
+
#ifdef LISP_FEATURE_SB_THREAD
if (SymbolValue(STOP_FOR_GC_PENDING,thread) != NIL) {
- /* 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();
+
+ /* No GC shall be lost. If SUB_GC triggers another GC then
+ * that should be handled on the spot. */
+ if (SymbolValue(GC_PENDING,thread) != NIL)
+ lose("GC_PENDING after doing gc.");
+#ifdef LISP_FEATURE_SB_THREAD
+ if (SymbolValue(STOP_FOR_GC_PENDING,thread) != NIL)
+ lose("STOP_FOR_GC_PENDING after doing gc.");
+#endif
+ /* Check two things. First, that gc does not clobber a handler
+ * that's already pending. Second, that there is no interrupt
+ * lossage: if original_pending_handler was NULL then even if
+ * an interrupt arrived during GC (POST-GC, really) it was
+ * handled. */
+ if (original_pending_handler != data->pending_handler)
+ lose("pending handler changed in gc: %x -> %d.",
+ original_pending_handler, data->pending_handler);
}
- /* 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);
-
- /* restore the saved signal mask from the original signal (the
- * one that interrupted us during the critical section) into the
- * os_context for the signal we're currently in the handler for.
- * This should ensure that when we return from the handler the
- * blocked signals are unblocked */
- sigcopyset(os_context_sigmask_addr(context), &data->pending_mask);
-
- sigemptyset(&data->pending_mask);
- /* This will break on sparc linux: the deferred handler really wants
- * to be called with a void_context */
- run_deferred_handler(data,(void *)context);
- }
+#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);
}
+ /* It is possible that the end of this function was reached
+ * without never actually doing anything, the tests in Lisp for
+ * when to call receive-pending-interrupt are not exact. */
+ FSHOW_SIGNAL((stderr, "/exiting interrupt_handle_pending\n"));
+#endif
}
\f
-/*
- * 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)
+#ifdef FOREIGN_FUNCTION_CALL_FLAG
boolean were_in_lisp;
#endif
union interrupt_handler handler;
+
check_blockables_blocked_or_lose();
+
+#ifndef LISP_FEATURE_WIN32
if (sigismember(&deferrable_sigset,signal))
check_interrupts_enabled_or_lose(context);
-
-#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 = interrupt_handlers[signal];
if (ARE_SAME_HANDLER(handler.c, SIG_IGN)) {
return;
}
-#if !defined(LISP_FEATURE_X86) && !defined(LISP_FEATURE_X86_64)
+#ifdef FOREIGN_FUNCTION_CALL_FLAG
were_in_lisp = !foreign_function_call_active;
if (were_in_lisp)
#endif
/* This can happen if someone tries to ignore or default one
* of the signals we need for runtime support, and the runtime
* support decides to pass on it. */
- lose("no handler for signal %d in interrupt_handle_now(..)", signal);
+ lose("no handler for signal %d in interrupt_handle_now(..)\n", signal);
} else if (lowtag_of(handler.lisp) == FUN_POINTER_LOWTAG) {
/* Once we've decided what to do about contexts in a
* all our allocation from C now goes through a PA wrapper,
* but still, doesn't hurt.
*
- * Yeah, but non-gencgc platforms that don't really wrap
- * allocation in PA. MG - 2005-08-29 */
-
- lispobj info_sap,context_sap = alloc_sap(context);
+ * 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. */
+ unblock_gc_signals();
+ context_sap = alloc_sap(context);
info_sap = alloc_sap(info);
- /* Allow signals again. */
- thread_sigmask(SIG_SETMASK, os_context_sigmask_addr(context), 0);
FSHOW_SIGNAL((stderr,"/calling Lisp-level handler\n"));
info_sap,
context_sap);
} else {
+ /* This cannot happen in sane circumstances. */
FSHOW_SIGNAL((stderr,"/calling C-level handler\n"));
+#ifndef LISP_FEATURE_WIN32
/* Allow signals again. */
thread_sigmask(SIG_SETMASK, os_context_sigmask_addr(context), 0);
-
- (*handler.c)(signal, info, void_context);
+#endif
+ (*handler.c)(signal, info, context);
}
-#if !defined(LISP_FEATURE_X86) && !defined(LISP_FEATURE_X86_64)
+#ifdef FOREIGN_FUNCTION_CALL_FLAG
if (were_in_lisp)
#endif
{
* 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) {
+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*, 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
boolean
maybe_defer_handler(void *handler, struct interrupt_data *data,
int signal, siginfo_t *info, os_context_t *context)
check_blockables_blocked_or_lose();
if (SymbolValue(INTERRUPT_PENDING,thread) != NIL)
- lose("interrupt already pending");
+ lose("interrupt already pending\n");
+ if (thread->interrupt_data->pending_handler)
+ lose("there is a pending handler already (PA)\n");
+ if (data->gc_blocked_deferrables)
+ lose("maybe_defer_handler: gc_blocked_deferrables true\n");
+ check_interrupt_context_or_lose(context);
/* If interrupts are disabled then INTERRUPT_PENDING is set and
* not PSEDUO_ATOMIC_INTERRUPTED. This is important for a pseudo
* atomic section inside a WITHOUT-INTERRUPTS.
+ *
+ * Also, if in_leaving_without_gcing_race_p then
+ * interrupt_handle_pending is going to be called soon, so
+ * stashing the signal away is safe.
*/
- if (SymbolValue(INTERRUPTS_ENABLED,thread) == NIL) {
+ if ((SymbolValue(INTERRUPTS_ENABLED,thread) == NIL) ||
+ in_leaving_without_gcing_race_p(thread)) {
store_signal_data_for_later(data,handler,signal,info,context);
SetSymbolValue(INTERRUPT_PENDING, T,thread);
FSHOW_SIGNAL((stderr,
- "/maybe_defer_handler(%x,%d),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)));
+ 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)) {
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));
+ "/maybe_defer_handler(%x,%d): deferred(PA)\n",
+ (unsigned int)handler,signal));
+ 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;
}
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 */
- sigcopyset(&(data->pending_mask),os_context_sigmask_addr(context));
- sigaddset_deferrable(os_context_sigmask_addr(context));
- }
+
+ 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);
-#ifdef LISP_FEATURE_DARWIN
- /* Work around G5 bug */
- DARWIN_FIX_CONTEXT(context);
-#endif
+ SAVE_ERRNO(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;
-
-#ifdef LISP_FEATURE_LINUX
- os_restore_fp_control(context);
-#endif
+ /* No FP control fixage needed, caller has done that. */
check_blockables_blocked_or_lose();
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=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(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(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
+/* 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;
- int i;
- 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) {
SetSymbolValue(STOP_FOR_GC_PENDING,T,thread);
- if (SymbolValue(GC_INHIBIT,thread) == NIL)
- arch_set_pseudo_atomic_interrupted(context);
- FSHOW_SIGNAL((stderr,"thread=%lu sig_stop_for_gc deferred\n",
- thread->os_thread));
- } else {
- /* need the context stored so it can have registers scavenged */
- fake_foreign_function_call(context);
+ FSHOW_SIGNAL((stderr, "sig_stop_for_gc deferred (*GC-INHIBIT*)\n"));
+ return;
+ } else if (arch_pseudo_atomic_atomic(context)) {
+ 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));
+ FSHOW_SIGNAL((stderr,"sig_stop_for_gc deferred (PA)\n"));
+ return;
+ }
- sigfillset(&ss); /* Block everything. */
- thread_sigmask(SIG_BLOCK,&ss,0);
+ FSHOW_SIGNAL((stderr, "/sig_stop_for_gc_handler\n"));
- /* The GC can't tell if a thread is a zombie, so this would be a
- * good time to let the kernel reap any of our children in that
- * awful state, to stop them from being waited for indefinitely.
- * Userland reaping is done later when GC is finished */
- if(thread->state!=STATE_RUNNING) {
- lose("sig_stop_for_gc_handler: wrong thread state: %ld\n",
- fixnum_value(thread->state));
- }
- thread->state=STATE_SUSPENDED;
- FSHOW_SIGNAL((stderr,"thread=%lu suspended\n",thread->os_thread));
-
- sigemptyset(&ss); sigaddset(&ss,SIG_STOP_FOR_GC);
- sigwaitinfo(&ss,0);
- 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));
- }
+ /* Not PA and GC not inhibited -- we can stop now. */
- undo_fake_foreign_function_call(context);
+ /* need the context stored so it can have registers scavenged */
+ fake_foreign_function_call(context);
+
+ /* Block everything. */
+ sigfillset(&ss);
+ thread_sigmask(SIG_BLOCK,&ss,0);
+
+ /* Not pending anymore. */
+ SetSymbolValue(GC_PENDING,NIL,thread);
+ SetSymbolValue(STOP_FOR_GC_PENDING,NIL,thread);
+
+ 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_SUSPENDED);
+ FSHOW_SIGNAL((stderr,"suspended\n"));
+
+ wait_for_thread_state_change(thread, STATE_SUSPENDED);
+ 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)));
+ }
+
+ 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(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 recieved", 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
*/
#if (defined(LISP_FEATURE_X86) || defined(LISP_FEATURE_X86_64))
-int *context_eflags_addr(os_context_t *context);
+extern int *context_eflags_addr(os_context_t *context);
#endif
extern lispobj call_into_lisp(lispobj fun, lispobj *args, int nargs);
extern void post_signal_tramp(void);
-void arrange_return_to_lisp_function(os_context_t *context, lispobj function)
+extern void call_into_lisp_tramp(void);
+void
+arrange_return_to_lisp_function(os_context_t *context, lispobj function)
{
+#ifndef LISP_FEATURE_WIN32
+ check_gc_signals_unblocked_in_sigset_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);
/* 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
u32 *sp=(u32 *)*os_context_register_addr(context,reg_ESP);
+#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) call_into_lisp_tramp;
+ *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-2)=*os_context_register_addr(context,reg_EBP);
*(sp-1)=*os_context_pc_addr(context);
+#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;
#endif
#ifdef LISP_FEATURE_X86
+
+#if !defined(LISP_FEATURE_DARWIN)
*os_context_pc_addr(context) = (os_context_register_t)call_into_lisp;
*os_context_register_addr(context,reg_ECX) = 0;
*os_context_register_addr(context,reg_EBP) = (os_context_register_t)(sp-2);
(os_context_register_t)(sp-15);
#else
*os_context_register_addr(context,reg_ESP) = (os_context_register_t)(sp-15);
-#endif
+#endif /* __NETBSD__ */
+#endif /* LISP_FEATURE_DARWIN */
+
#elif defined(LISP_FEATURE_X86_64)
*os_context_pc_addr(context) = (os_context_register_t)call_into_lisp;
*os_context_register_addr(context,reg_RCX) = 0;
*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 interrupt_thread_handler(int num, siginfo_t *info, void *v_context)
-{
- os_context_t *context = (os_context_t*)arch_os_get_context(&v_context);
- /* The order of interrupt execution is peculiar. If thread A
- * interrupts thread B with I1, I2 and B for some reason receives
- * I1 when FUN2 is already on the list, then it is FUN2 that gets
- * to run first. But when FUN2 is run SIG_INTERRUPT_THREAD is
- * enabled again and I2 hits pretty soon in FUN2 and run
- * FUN1. This is of course just one scenario, and the order of
- * thread interrupt execution is undefined. */
- struct thread *th=arch_os_get_current_thread();
- struct cons *c;
- lispobj function;
- if (th->state != STATE_RUNNING)
- lose("interrupt_thread_handler: thread %lu in wrong state: %d\n",
- th->os_thread,fixnum_value(th->state));
- get_spinlock(&th->interrupt_fun_lock,(long)th);
- c=((struct cons *)native_pointer(th->interrupt_fun));
- function=c->car;
- th->interrupt_fun=c->cdr;
- release_spinlock(&th->interrupt_fun_lock);
- if (function==NIL)
- lose("interrupt_thread_handler: NIL function\n");
- arrange_return_to_lisp_function(context,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() {
- funcall0(SymbolFunction(UNDEFINED_ALIEN_FUNCTION_ERROR));
+void
+undefined_alien_function(void)
+{
+ funcall0(StaticSymbolFunction(UNDEFINED_ALIEN_FUNCTION_ERROR));
}
-boolean handle_guard_page_triggered(os_context_t *context,os_vm_address_t addr)
+boolean
+handle_guard_page_triggered(os_context_t *context,os_vm_address_t addr)
{
struct thread *th=arch_os_get_current_thread();
* protection so the error handler has some headroom, protect the
* previous page so that we can catch returns from the guard page
* and restore it. */
- protect_control_stack_guard_page(th,0);
- protect_control_stack_return_guard_page(th,1);
+ corruption_warning_and_maybe_lose("Control stack exhausted");
+ protect_control_stack_guard_page(0, NULL);
+ protect_control_stack_return_guard_page(1, NULL);
+#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) &&
* unprotect this one. This works even if we somehow missed
* the return-guard-page, and hit it on our way to new
* exhaustion instead. */
- protect_control_stack_guard_page(th,1);
- protect_control_stack_return_guard_page(th,0);
+ fprintf(stderr, "INFO: Control stack guard page reprotected\n");
+ protect_control_stack_guard_page(1, NULL);
+ protect_control_stack_return_guard_page(0, NULL);
+ return 1;
+ }
+ else if(addr >= BINDING_STACK_GUARD_PAGE(th) &&
+ addr < BINDING_STACK_GUARD_PAGE(th) + os_vm_page_size) {
+ corruption_warning_and_maybe_lose("Binding stack exhausted");
+ protect_binding_stack_guard_page(0, NULL);
+ protect_binding_stack_return_guard_page(1, NULL);
+
+ /* 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) {
+ fprintf(stderr, "INFO: Binding stack guard page reprotected\n");
+ protect_binding_stack_guard_page(1, NULL);
+ protect_binding_stack_return_guard_page(0, NULL);
+ return 1;
+ }
+ else if(addr >= ALIEN_STACK_GUARD_PAGE(th) &&
+ addr < ALIEN_STACK_GUARD_PAGE(th) + os_vm_page_size) {
+ corruption_warning_and_maybe_lose("Alien stack exhausted");
+ protect_alien_stack_guard_page(0, NULL);
+ protect_alien_stack_return_guard_page(1, NULL);
+
+ /* 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) {
+ fprintf(stderr, "INFO: Alien stack guard page reprotected\n");
+ protect_alien_stack_guard_page(1, NULL);
+ protect_alien_stack_return_guard_page(0, NULL);
return 1;
}
else if (addr >= undefined_alien_address &&
addr < undefined_alien_address + os_vm_page_size) {
arrange_return_to_lisp_function
- (context, SymbolFunction(UNDEFINED_ALIEN_VARIABLE_ERROR));
+ (context, StaticSymbolFunction(UNDEFINED_ALIEN_VARIABLE_ERROR));
return 1;
}
else return 0;
}
+\f
+/*
+ * noise to install handlers
+ */
-#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 */
+#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;
-boolean
-interrupt_maybe_gc(int signal, siginfo_t *info, void *void_context)
+#define SA_NODEFER_TEST_BLOCK_SIGNAL SIGABRT
+#define SA_NODEFER_TEST_KILL_SIGNAL SIGUSR1
+
+static void
+sigaction_nodefer_test_handler(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);
- }
+ sigset_t empty, current;
+ int i;
+ sigemptyset(&empty);
+ thread_sigmask(SIG_BLOCK, &empty, ¤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;
}
- return 1;
- }
- return 0;
+ if (sigaction_nodefer_works == -1)
+ sigaction_nodefer_works = 1;
}
-#endif
-
-/* this is also used by gencgc, in alloc() */
-boolean
-interrupt_maybe_gc_int(int signal, siginfo_t *info, void *void_context)
+static void
+see_if_sigaction_nodefer_works(void)
{
- os_context_t *context=(os_context_t *) void_context;
- struct thread *thread=arch_os_get_current_thread();
+ 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);
+}
- fake_foreign_function_call(context);
+#undef SA_NODEFER_TEST_BLOCK_SIGNAL
+#undef SA_NODEFER_TEST_KILL_SIGNAL
- /* 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.
- */
+static void
+unblock_me_trampoline(int signal, siginfo_t *info, void *void_context)
+{
+ SAVE_ERRNO(context,void_context);
+ sigset_t unblock;
- /* 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.
- */
- 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;
- sigaddset(&new,SIG_STOP_FOR_GC);
- thread_sigmask(SIG_UNBLOCK,&new,0);
- }
-#endif
- funcall0(SymbolFunction(SUB_GC));
+ sigemptyset(&unblock);
+ sigaddset(&unblock, signal);
+ thread_sigmask(SIG_UNBLOCK, &unblock, 0);
+ interrupt_handle_now(signal, info, context);
+ RESTORE_ERRNO;
+}
- undo_fake_foreign_function_call(context);
- return 1;
+static void
+low_level_unblock_me_trampoline(int signal, siginfo_t *info, void *void_context)
+{
+ SAVE_ERRNO(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;
}
-\f
-/*
- * noise to install handlers
- */
+static void
+low_level_handle_now_handler(int signal, siginfo_t *info, void *void_context)
+{
+ SAVE_ERRNO(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;
if (0 > signal || signal >= NSIG) {
- lose("bad signal number %d", signal);
+ lose("bad signal number %d\n", signal);
}
- if (sigismember(&deferrable_sigset,signal))
+ 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 = handler;
+ sa.sa_sigaction = low_level_handle_now_handler;
sigcopyset(&sa.sa_mask, &blockable_sigset);
- sa.sa_flags = SA_SIGINFO | SA_RESTART;
+ sa.sa_flags = SA_SIGINFO | SA_RESTART
+ | (sigaction_nodefer_works ? SA_NODEFER : 0);
#ifdef LISP_FEATURE_C_STACK_IS_CONTROL_STACK
- if((signal==SIG_MEMORY_FAULT)
-#ifdef SIG_INTERRUPT_THREAD
- || (signal==SIG_INTERRUPT_THREAD)
-#endif
- )
+ if((signal==SIG_MEMORY_FAULT))
sa.sa_flags |= SA_ONSTACK;
#endif
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*))
+install_handler(int signal, void handler(int, siginfo_t*, os_context_t*))
{
+#ifndef LISP_FEATURE_WIN32
struct sigaction sa;
sigset_t old, new;
union interrupt_handler oldhandler;
(unsigned int)interrupt_low_level_handlers[signal]));
if (interrupt_low_level_handlers[signal]==0) {
if (ARE_SAME_HANDLER(handler, SIG_DFL) ||
- ARE_SAME_HANDLER(handler, SIG_IGN)) {
- sa.sa_sigaction = handler;
- } else if (sigismember(&deferrable_sigset, signal)) {
+ ARE_SAME_HANDLER(handler, SIG_IGN))
+ sa.sa_sigaction = (void (*)(int, siginfo_t*, void*))handler;
+ else if (sigismember(&deferrable_sigset, signal))
sa.sa_sigaction = maybe_now_maybe_later;
- } else {
+ else if (!sigaction_nodefer_works &&
+ !sigismember(&blockable_sigset, signal))
+ sa.sa_sigaction = unblock_me_trampoline;
+ else
sa.sa_sigaction = interrupt_handle_now_handler;
- }
sigcopyset(&sa.sa_mask, &blockable_sigset);
- sa.sa_flags = SA_SIGINFO | SA_RESTART;
+ sa.sa_flags = SA_SIGINFO | SA_RESTART |
+ (sigaction_nodefer_works ? SA_NODEFER : 0);
sigaction(signal, &sa, NULL);
}
FSHOW((stderr, "/leaving POSIX install_handler(%d, ..)\n", signal));
return (unsigned long)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)
{
+ lose("SIGABRT received.\n");
+}
+
+void
+interrupt_init(void)
+{
+#ifndef LISP_FEATURE_WIN32
int i;
SHOW("entering interrupt_init()");
+ see_if_sigaction_nodefer_works();
sigemptyset(&deferrable_sigset);
sigemptyset(&blockable_sigset);
+ sigemptyset(&gc_sigset);
sigaddset_deferrable(&deferrable_sigset);
sigaddset_blockable(&blockable_sigset);
+ sigaddset_gc(&gc_sigset);
/* Set up high level handler information. */
for (i = 0; i < NSIG; i++) {
* 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;
}
-
+ undoably_install_low_level_interrupt_handler(SIGABRT, sigabrt_handler);
SHOW("returning from interrupt_init()");
+#endif
+}
+
+#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", addr);
+ 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);
+ unblock_gc_signals();
+ context_sap = alloc_sap(context);
+#ifndef LISP_FEATURE_WIN32
+ 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) {
+ case trap_PendingInterrupt:
+ FSHOW((stderr, "/<trap pending interrupt>\n"));
+ arch_skip_instruction(context);
+ interrupt_handle_pending(context);
+ break;
+ case trap_Error:
+ case trap_Cerror:
+ FSHOW((stderr, "/<trap error/cerror %d>\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
+ case trap_Halt:
+ fake_foreign_function_call(context);
+ lose("%%PRIMITIVE HALT called; the party is over.\n");
+ default:
+ unhandled_trap_error(context);
+ }
}