* files for more information.
*/
+
+/* As far as I can tell, what's going on here is:
+ *
+ * In the case of most signals, when Lisp asks us to handle the
+ * signal, the outermost handler (the one actually passed to UNIX) is
+ * either interrupt_handle_now(..) or maybe_now_maybe_later(..).
+ * In that case, the Lisp-level handler is stored in interrupt_handlers[..]
+ * and interrupt_low_level_handlers[..] is cleared.
+ *
+ * However, some signals need special handling, e.g.
+ *
+ * o the SIGSEGV (for e.g. Linux) or SIGBUS (for e.g. FreeBSD) used by the
+ * garbage collector to detect violations of write protection,
+ * because some cases of such signals (e.g. GC-related violations of
+ * write protection) are handled at C level and never passed on to
+ * Lisp. For such signals, we still store any Lisp-level handler
+ * in interrupt_handlers[..], but for the outermost handle we use
+ * the value from interrupt_low_level_handlers[..], instead of the
+ * ordinary interrupt_handle_now(..) or interrupt_handle_later(..).
+ *
+ * o the SIGTRAP (Linux/Alpha) which Lisp code uses to handle breakpoints,
+ * pseudo-atomic sections, and some classes of error (e.g. "function
+ * not defined"). This never goes anywhere near the Lisp handlers at all.
+ * See runtime/alpha-arch.c and code/signal.lisp
+ *
+ * - WHN 20000728, dan 20010128 */
+
+#include "sbcl.h"
+
#include <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 "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 sigaddset_blockable(sigset_t *s)
+/* When we catch an internal error, should we pass it back to Lisp to
+ * be handled in a high-level way? (Early in cold init, the answer is
+ * 'no', because Lisp is still too brain-dead to handle anything.
+ * After sufficient initialization has been completed, the answer
+ * becomes 'yes'.) */
+boolean internal_errors_enabled = 0;
+
+#ifndef LISP_FEATURE_WIN32
+static
+void (*interrupt_low_level_handlers[NSIG]) (int, siginfo_t*, os_context_t*);
+#endif
+union interrupt_handler interrupt_handlers[NSIG];
+
+/* Under Linux on some architectures, we appear to have to restore the
+ * FPU control word from the context, as after the signal is delivered
+ * we appear to have a null FPU control word. */
+#if defined(RESTORE_FP_CONTROL_FROM_CONTEXT)
+#define RESTORE_FP_CONTROL_WORD(context,void_context) \
+ os_context_t *context = arch_os_get_context(&void_context); \
+ os_restore_fp_control(context);
+#else
+#define RESTORE_FP_CONTROL_WORD(context,void_context) \
+ os_context_t *context = arch_os_get_context(&void_context);
+#endif
+
+/* Foreign code may want to start some threads on its own.
+ * Non-targetted, truly asynchronous signals can be delivered to
+ * basically any thread, but invoking Lisp handlers in such foregign
+ * threads is really bad, so let's resignal it.
+ *
+ * This should at least bring attention to the problem, but it cannot
+ * work for SIGSEGV and similar. It is good enough for timers, and
+ * maybe all deferrables. */
+
+#ifdef LISP_FEATURE_SB_THREAD
+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)
+{
+#ifdef LISP_FEATURE_SB_THREAD
+ 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);
+#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);
+\f
+
+/* Generic signal related utilities. */
+
+void
+get_current_sigmask(sigset_t *sigset)
+{
+ /* Get the current sigmask, by blocking the empty set. */
+ thread_sigmask(SIG_BLOCK, 0, sigset);
+}
+
+void
+block_signals(sigset_t *what, sigset_t *where, sigset_t *old)
+{
+ if (where) {
+ int i;
+ if (old)
+ sigcopyset(old, where);
+ for(i = 1; i < NSIG; i++) {
+ if (sigismember(what, i))
+ sigaddset(where, i);
+ }
+ } else {
+ thread_sigmask(SIG_BLOCK, what, old);
+ }
+}
+
+void
+unblock_signals(sigset_t *what, sigset_t *where, sigset_t *old)
+{
+ if (where) {
+ int i;
+ if (old)
+ sigcopyset(old, where);
+ for(i = 1; i < NSIG; i++) {
+ if (sigismember(what, i))
+ sigdelset(where, i);
+ }
+ } else {
+ thread_sigmask(SIG_UNBLOCK, what, old);
+ }
+}
+
+static void
+print_sigset(sigset_t *sigset)
+{
+ int i;
+ for(i = 1; i < NSIG; i++) {
+ if (sigismember(sigset, i))
+ fprintf(stderr, "Signal %d masked\n", i);
+ }
+}
+
+/* Return 1 is all signals is sigset2 are masked in sigset, return 0
+ * if all re unmasked else die. Passing NULL for sigset is a shorthand
+ * for the current sigmask. */
+boolean
+all_signals_blocked_p(sigset_t *sigset, sigset_t *sigset2,
+ const char *name)
+{
+#if !defined(LISP_FEATURE_WIN32)
+ 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
+}
+\f
+
+/* Deferrables, blockables, gc signals. */
+
+void
+sigaddset_deferrable(sigset_t *s)
{
sigaddset(s, SIGHUP);
sigaddset(s, SIGINT);
+ sigaddset(s, SIGTERM);
sigaddset(s, SIGQUIT);
sigaddset(s, SIGPIPE);
sigaddset(s, SIGALRM);
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);
}
-/* When we catch an internal error, should we pass it back to Lisp to
- * be handled in a high-level way? (Early in cold init, the answer is
- * 'no', because Lisp is still too brain-dead to handle anything.
- * After sufficient initialization has been completed, the answer
- * becomes 'yes'.) */
-boolean internal_errors_enabled = 0;
+void
+sigaddset_blockable(sigset_t *sigset)
+{
+ sigaddset_deferrable(sigset);
+ sigaddset_gc(sigset);
+}
-os_context_t *lisp_interrupt_contexts[MAX_INTERRUPTS];
+void
+sigaddset_gc(sigset_t *sigset)
+{
+#ifdef LISP_FEATURE_SB_THREAD
+ sigaddset(sigset,SIG_STOP_FOR_GC);
+#endif
+}
-/* As far as I can tell, what's going on here is:
- *
- * In the case of most signals, when Lisp asks us to handle the
- * signal, the outermost handler (the one actually passed to UNIX) is
- * either interrupt_handle_now(..) or interrupt_handle_later(..).
- * In that case, the Lisp-level handler is stored in interrupt_handlers[..]
- * and interrupt_low_level_handlers[..] is cleared.
- *
- * However, some signals need special handling, e.g.
- *
- * o the SIGSEGV (for e.g. Linux) or SIGBUS (for e.g. FreeBSD) used by the
- * garbage collector to detect violations of write protection,
- * because some cases of such signals (e.g. GC-related violations of
- * write protection) are handled at C level and never passed on to
- * Lisp. For such signals, we still store any Lisp-level handler
- * in interrupt_handlers[..], but for the outermost handle we use
- * the value from interrupt_low_level_handlers[..], instead of the
- * ordinary interrupt_handle_now(..) or interrupt_handle_later(..).
- *
- * o the SIGTRAP (Linux/Alpha) which Lisp code uses to handle breakpoints,
- * pseudo-atomic sections, and some classes of error (e.g. "function
- * not defined"). This never goes anywhere near the Lisp handlers at all.
- * See runtime/alpha-arch.c and code/signal.lisp
- *
- * - WHN 20000728, dan 20010128 */
+/* initialized in interrupt_init */
+sigset_t deferrable_sigset;
+sigset_t blockable_sigset;
+sigset_t gc_sigset;
+#endif
-void (*interrupt_low_level_handlers[NSIG]) (int, siginfo_t*, void*) = {0};
-union interrupt_handler interrupt_handlers[NSIG];
+#if !defined(LISP_FEATURE_WIN32)
+boolean
+deferrables_blocked_p(sigset_t *sigset)
+{
+ return all_signals_blocked_p(sigset, &deferrable_sigset, "deferrable");
+}
+#endif
-/* signal number, siginfo_t, and old mask information for pending signal
- *
- * pending_signal=0 when there is no pending signal. */
-static int pending_signal = 0;
-static siginfo_t pending_info;
-static sigset_t pending_mask;
+void
+check_deferrables_unblocked_or_lose(sigset_t *sigset)
+{
+#if !defined(LISP_FEATURE_WIN32)
+ if (deferrables_blocked_p(sigset))
+ lose("deferrables blocked\n");
+#endif
+}
+
+void
+check_deferrables_blocked_or_lose(sigset_t *sigset)
+{
+#if !defined(LISP_FEATURE_WIN32)
+ if (!deferrables_blocked_p(sigset))
+ lose("deferrables unblocked\n");
+#endif
+}
+
+#if !defined(LISP_FEATURE_WIN32)
+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)
+ if (blockables_blocked_p(sigset))
+ lose("blockables blocked\n");
+#endif
+}
+
+void
+check_blockables_blocked_or_lose(sigset_t *sigset)
+{
+#if !defined(LISP_FEATURE_WIN32)
+ if (!blockables_blocked_p(sigset))
+ lose("blockables unblocked\n");
+#endif
+}
+
+#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
+}
+
+void
+block_deferrable_signals(sigset_t *where, sigset_t *old)
+{
+#ifndef LISP_FEATURE_WIN32
+ block_signals(&deferrable_sigset, where, old);
+#endif
+}
+
+void
+block_blockable_signals(sigset_t *where, sigset_t *old)
+{
+#ifndef LISP_FEATURE_WIN32
+ block_signals(&blockable_sigset, where, old);
+#endif
+}
+
+void
+block_gc_signals(sigset_t *where, sigset_t *old)
+{
+#ifndef LISP_FEATURE_WIN32
+ block_signals(&gc_sigset, where, old);
+#endif
+}
+
+void
+unblock_deferrable_signals(sigset_t *where, sigset_t *old)
+{
+#ifndef LISP_FEATURE_WIN32
+ if (interrupt_handler_pending_p())
+ lose("unblock_deferrable_signals: losing proposition\n");
+ check_gc_signals_unblocked_or_lose(where);
+ unblock_signals(&deferrable_sigset, where, old);
+#endif
+}
+
+void
+unblock_blockable_signals(sigset_t *where, sigset_t *old)
+{
+#ifndef LISP_FEATURE_WIN32
+ unblock_signals(&blockable_sigset, where, old);
+#endif
+}
+
+void
+unblock_gc_signals(sigset_t *where, sigset_t *old)
+{
+#ifndef LISP_FEATURE_WIN32
+ unblock_signals(&gc_sigset, where, old);
+#endif
+}
+
+void
+unblock_signals_in_context_and_maybe_warn(os_context_t *context)
+{
+#ifndef LISP_FEATURE_WIN32
+ sigset_t *sigset = os_context_sigmask_addr(context);
+ 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);
+ }
+ if (!interrupt_handler_pending_p()) {
+ unblock_deferrable_signals(sigset, 0);
+ }
+#endif
+}
+\f
+
+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");
+}
-static boolean maybe_gc_pending = 0;
+/* 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. */
+ 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
+}
+
+/* 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");
+ 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);
+ /* If deferrables are unblocked then we are open to signals
+ * that run lisp code. */
+ check_gc_signals_unblocked_or_lose(sigset);
+ }
+#endif
+}
\f
/*
* utility routines used by various signal handlers
*/
-void
-build_fake_control_stack_frames(os_context_t *context)
+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) {
+ (lispobj *)(unsigned long)
+ (*os_context_register_addr(context, reg_CSP));
+ if ((lispobj *)(unsigned long)
+ (*os_context_register_addr(context, reg_CFP))
+ == current_control_frame_pointer) {
/* There is a small window during call where the callee's
* frame isn't built yet. */
if (lowtag_of(*os_context_register_addr(context, reg_CODE))
- == FUN_POINTER_LOWTAG) {
+ == 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);
+ *os_context_register_addr(context, reg_OCFP);
current_control_frame_pointer[1] =
- *os_context_register_addr(context, reg_LRA);
+ *os_context_register_addr(context, reg_LRA);
current_control_frame_pointer += 8;
/* Build our frame on top of it. */
oldcont = (lispobj)(*os_context_register_addr(context, reg_CFP));
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));
+ (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
dynamic_space_free_pointer =
- (lispobj *)(*os_context_register_addr(context, reg_ALLOC));
-#ifdef alpha
+ (lispobj *)(unsigned long)
+ (*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 ((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
#ifdef reg_BSP
current_binding_stack_pointer =
- (lispobj *)(*os_context_register_addr(context, reg_BSP));
+ (lispobj *)(unsigned long)
+ (*os_context_register_addr(context, reg_BSP));
#endif
- build_fake_control_stack_frames(context);
+ build_fake_control_stack_frames(thread,context);
/* Do dynamic binding of the active interrupt context index
* and save the context in the context array. */
- context_index = SymbolValue(FREE_INTERRUPT_CONTEXT_INDEX)>>2;
- /* FIXME: Ick! Why use abstract "make_fixnum" in some places if
- * you're going to convert from fixnum by bare >>2 in other
- * places? Use fixnum_value(..) here, and look for other places
- * which do bare >> and << for fixnum_value and make_fixnum. */
+ context_index =
+ 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));
+ make_fixnum(context_index + 1),thread);
- lisp_interrupt_contexts[context_index] = context;
+ 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)
{
+ 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 */
+#ifdef FOREIGN_FUNCTION_CALL_FLAG
foreign_function_call_active = 0;
+#endif
- /* Undo dynamic binding. */
- /* ### Do I really need to unbind_to_here()? */
- /* FIXME: Is this to undo the binding of
- * FREE_INTERRUPT_CONTEXT_INDEX? If so, we should say so. And
- * perhaps yes, unbind_to_here() really would be clearer and less
- * fragile.. */
- /* dan (2001.08.10) thinks the above supposition is probably correct */
- unbind();
+ /* 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);
+ if (!internal_errors_enabled) {
+ describe_internal_error(context);
+ /* There's no good way to recover from an internal error
+ * before the Lisp error handling mechanism is set up. */
+ lose("internal error too early in init, can't recover\n");
+ }
+
/* Allocate the SAP object while the interrupts are still
* disabled. */
- if (internal_errors_enabled) {
- context_sap = alloc_sap(context);
- }
+ unblock_gc_signals(0, 0);
+ context_sap = alloc_sap(context);
- sigprocmask(SIG_SETMASK, os_context_sigmask_addr(context), 0);
+#ifndef LISP_FEATURE_WIN32
+ thread_sigmask(SIG_SETMASK, os_context_sigmask_addr(context), 0);
+#endif
- if (internal_errors_enabled) {
- SHOW("in interrupt_internal_error");
+#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
- /* 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);
+ /* Display some rudimentary debugging information about the
+ * error, so that even if the Lisp error handler gets badly
+ * confused, we have a chance to determine what's going on. */
+ describe_internal_error(context);
#endif
- funcall2(SymbolFunction(INTERNAL_ERROR), context_sap,
- continuable ? T : NIL);
- } else {
- describe_internal_error(context);
- /* There's no good way to recover from an internal error
- * before the Lisp error handling mechanism is set up. */
- lose("internal error too early in init, can't recover");
- }
- undo_fake_foreign_function_call(context);
- if (continuable) {
- arch_skip_instruction(context);
- }
+ funcall2(StaticSymbolFunction(INTERNAL_ERROR), context_sap,
+ continuable ? T : NIL);
+
+ undo_fake_foreign_function_call(context); /* blocks signals again */
+ if (continuable)
+ arch_skip_instruction(context);
}
-/* This function handles pending interrupts. Note that in C/kernel
- * terms we dealt with the signal already; we just haven't decided
- * whether to call a Lisp handler or do a GC or something like that.
- * If it helps, you can think of pending_{signal,mask,info} as a
- * one-element queue of signals that we have acknowledged but not
- * processed */
+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)
{
-#ifndef __i386__
- boolean were_in_lisp = !foreign_function_call_active;
-#endif
+ /* 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 pseudo atomic.");
+ }
- SetSymbolValue(INTERRUPT_PENDING, NIL);
+ FSHOW_SIGNAL((stderr, "/entering interrupt_handle_pending\n"));
- if (maybe_gc_pending) {
- maybe_gc_pending = 0;
-#ifndef __i386__
- if (were_in_lisp)
+ check_blockables_blocked_or_lose(0);
+
+ /* 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
- {
- fake_foreign_function_call(context);
- }
- funcall0(SymbolFunction(MAYBE_GC));
-#ifndef __i386__
- if (were_in_lisp)
+ data->gc_blocked_deferrables = 0;
+ }
+
+ if (SymbolValue(GC_INHIBIT,thread)==NIL) {
+ void *original_pending_handler = data->pending_handler;
+
+#ifdef LISP_FEATURE_SB_THREAD
+ if (SymbolValue(STOP_FOR_GC_PENDING,thread) != NIL) {
+ /* STOP_FOR_GC_PENDING and GC_PENDING are cleared by
+ * the signal handler if it actually stops us. */
+ arch_clear_pseudo_atomic_interrupted(context);
+ sig_stop_for_gc_handler(SIG_STOP_FOR_GC,NULL,context);
+ } else
#endif
- {
- undo_fake_foreign_function_call(context);
+ /* Test for T and not for != NIL since the value :IN-PROGRESS
+ * is used in SUB-GC as part of the mechanism to supress
+ * recursive gcs.*/
+ if (SymbolValue(GC_PENDING,thread) == T) {
+
+ /* Two reasons for doing this. First, if there is a
+ * pending handler we don't want to run. Second, we are
+ * going to clear pseudo atomic interrupted to avoid
+ * spurious trapping on every allocation in SUB_GC and
+ * having a pending handler with interrupts enabled and
+ * without pseudo atomic interrupted breaks an
+ * invariant. */
+ if (data->pending_handler) {
+ bind_variable(ALLOW_WITH_INTERRUPTS, NIL, thread);
+ bind_variable(INTERRUPTS_ENABLED, NIL, thread);
+ }
+
+ arch_clear_pseudo_atomic_interrupted(context);
+
+ /* GC_PENDING is cleared in SUB-GC, or if another thread
+ * is doing a gc already we will get a SIG_STOP_FOR_GC and
+ * that will clear it.
+ *
+ * If there is a pending handler or gc was triggerred in a
+ * signal handler then maybe_gc won't run POST_GC and will
+ * return normally. */
+ if (!maybe_gc(context))
+ lose("GC not inhibited but maybe_gc did not GC.");
+
+ if (data->pending_handler) {
+ unbind(thread);
+ unbind(thread);
+ }
+ } else if (SymbolValue(GC_PENDING,thread) != NIL) {
+ /* It's not NIL or T so GC_PENDING is :IN-PROGRESS. If
+ * GC-PENDING is not NIL then we cannot trap on pseudo
+ * atomic due to GC (see if(GC_PENDING) logic in
+ * cheneygc.c an gengcgc.c), plus there is a outer
+ * WITHOUT-INTERRUPTS SUB_GC, so how did we end up
+ * here? */
+ lose("Trapping to run pending handler while GC in progress.");
}
+
+ check_blockables_blocked_or_lose(0);
+
+ /* No GC shall be lost. If SUB_GC triggers another GC then
+ * that should be handled on the spot. */
+ if (SymbolValue(GC_PENDING,thread) != NIL)
+ lose("GC_PENDING after doing gc.");
+#ifdef 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);
}
- /* FIXME: This isn't very clear. It would be good to reverse
- * engineer it and rewrite the code more clearly, or write a clear
- * explanation of what's going on in the comments, or both.
- *
- * WHN's question 1a: How come we unconditionally copy from
- * pending_mask into the context, and then test whether
- * pending_signal is set?
- *
- * WHN's question 1b: If pending_signal wasn't set, how could
- * pending_mask be valid?
- *
- * Dan Barlow's reply (sbcl-devel 2001-03-13): And the answer is -
- * or appears to be - because interrupt_maybe_gc set it that way
- * (look in the #ifndef __i386__ bit). We can't GC during a
- * pseudo-atomic, so we set maybe_gc_pending=1 and
- * arch_set_pseudo_atomic_interrupted(..) When we come out of
- * pseudo_atomic we're marked as interrupted, so we call
- * interrupt_handle_pending, which does the GC using the pending
- * context (it needs a context so that it has registers to use as
- * GC roots) then notices there's no actual interrupt handler to
- * call, so doesn't. That's the second question [1b] answered,
- * anyway. Why we still need to copy the pending_mask into the
- * context given that we're now done with the context anyway, I
- * couldn't say. */
-#if 0
- memcpy(os_context_sigmask_addr(context), &pending_mask,
- 4 /* sizeof(sigset_t) */ );
-#endif
- sigemptyset(&pending_mask);
- if (pending_signal) {
- int signal = pending_signal;
- siginfo_t info;
- memcpy(&info, &pending_info, sizeof(siginfo_t));
- pending_signal = 0;
- interrupt_handle_now(signal, &info, context);
+#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);
}
+#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"));
}
\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;
-#ifndef __i386__
+#ifdef FOREIGN_FUNCTION_CALL_FLAG
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
+ check_blockables_blocked_or_lose(0);
+
+#ifndef LISP_FEATURE_WIN32
+ 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 __i386__
+
+#ifdef FOREIGN_FUNCTION_CALL_FLAG
were_in_lisp = !foreign_function_call_active;
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) {
-
- /* Allocate the SAPs while the interrupts are still disabled.
- * (FIXME: Why? This is the way it was done in CMU CL, and it
- * even had the comment noting that this is the way it was
- * done, but no motivation..) */
- lispobj info_sap,context_sap = alloc_sap(context);
+ /* Once we've decided what to do about contexts in a
+ * return-elsewhere world (the original context will no longer
+ * be available; should we copy it or was nobody using it anyway?)
+ * then we should convert this to return-elsewhere */
+
+ /* CMUCL comment said "Allocate the SAPs while the interrupts
+ * are still disabled.". I (dan, 2003.08.21) assume this is
+ * because we're not in pseudoatomic and allocation shouldn't
+ * be interrupted. In which case it's no longer an issue as
+ * all our allocation from C now goes through a PA wrapper,
+ * but still, doesn't hurt.
+ *
+ * Yeah, but non-gencgc platforms don't really wrap allocation
+ * in PA. MG - 2005-08-29 */
+
+ lispobj info_sap, context_sap;
+ /* Leave deferrable signals blocked, the handler itself will
+ * allow signals again when it sees fit. */
+ unblock_gc_signals(0, 0);
+ 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"));
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"));
+#ifndef LISP_FEATURE_WIN32
/* 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);
+#endif
+ (*handler.c)(signal, info, context);
}
-#ifndef __i386__
+#ifdef FOREIGN_FUNCTION_CALL_FLAG
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
+ * are that some signal was deferred during the section. Note that as
+ * far as C or the kernel is concerned we dealt with the signal
+ * already; we're just doing the Lisp-level processing now that we
+ * put off then */
static void
-maybe_now_maybe_later(int signal, siginfo_t *info, void *void_context)
+run_deferred_handler(struct interrupt_data *data, os_context_t *context)
{
- os_context_t *context = arch_os_get_context(&void_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);
+}
-#ifdef LISP_FEATURE_LINUX
- os_restore_fp_control(context);
-#endif
-
- /* see comments at top of code/signal.lisp for what's going on here
- * with INTERRUPTS_ENABLED/INTERRUPT_HANDLE_NOW
+#ifndef LISP_FEATURE_WIN32
+boolean
+maybe_defer_handler(void *handler, struct interrupt_data *data,
+ int signal, siginfo_t *info, os_context_t *context)
+{
+ struct thread *thread=arch_os_get_current_thread();
+
+ check_blockables_blocked_or_lose(0);
+
+ if (SymbolValue(INTERRUPT_PENDING,thread) != NIL)
+ lose("interrupt already pending\n");
+ if (thread->interrupt_data->pending_handler)
+ lose("there is a pending handler already (PA)\n");
+ if (data->gc_blocked_deferrables)
+ lose("maybe_defer_handler: gc_blocked_deferrables true\n");
+ check_interrupt_context_or_lose(context);
+ /* If interrupts are disabled then INTERRUPT_PENDING is set and
+ * not PSEDUO_ATOMIC_INTERRUPTED. This is important for a pseudo
+ * atomic section inside a WITHOUT-INTERRUPTS.
+ *
+ * Also, if in_leaving_without_gcing_race_p then
+ * interrupt_handle_pending is going to be called soon, so
+ * stashing the signal away is safe.
*/
- if (SymbolValue(INTERRUPTS_ENABLED) == NIL) {
-
- /* FIXME: This code is exactly the same as the code in the
- * other leg of the if(..), and should be factored out into
- * a shared function. */
- pending_signal = signal;
- memcpy(&pending_info, info, sizeof(siginfo_t));
- memcpy(&pending_mask,
- os_context_sigmask_addr(context),
- sizeof(sigset_t));
- sigaddset_blockable(os_context_sigmask_addr(context));
- SetSymbolValue(INTERRUPT_PENDING, T);
-
- } else if (
-#ifndef __i386__
- (!foreign_function_call_active) &&
-#endif
- arch_pseudo_atomic_atomic(context)) {
-
- /* FIXME: It would probably be good to replace these bare
- * memcpy(..) calls with calls to cpy_siginfo_t and
- * cpy_sigset_t, so that we only have to get the sizeof
- * expressions right in one place, and after that static type
- * checking takes over. */
- pending_signal = signal;
- memcpy(&pending_info, info, sizeof(siginfo_t));
- memcpy(&pending_mask,
- os_context_sigmask_addr(context),
- sizeof(sigset_t));
- sigaddset_blockable(os_context_sigmask_addr(context));
-
- arch_set_pseudo_atomic_interrupted(context);
+ if ((SymbolValue(INTERRUPTS_ENABLED,thread) == NIL) ||
+ in_leaving_without_gcing_race_p(thread)) {
+ FSHOW_SIGNAL((stderr,
+ "/maybe_defer_handler(%x,%d): deferred (RACE=%d)\n",
+ (unsigned int)handler,signal,
+ in_leaving_without_gcing_race_p(thread)));
+ store_signal_data_for_later(data,handler,signal,info,context);
+ SetSymbolValue(INTERRUPT_PENDING, T,thread);
+ check_interrupt_context_or_lose(context);
+ return 1;
+ }
+ /* a slightly confusing test. arch_pseudo_atomic_atomic() doesn't
+ * actually use its argument for anything on x86, so this branch
+ * may succeed even when context is null (gencgc alloc()) */
+ if (arch_pseudo_atomic_atomic(context)) {
+ FSHOW_SIGNAL((stderr,
+ "/maybe_defer_handler(%x,%d): deferred(PA)\n",
+ (unsigned int)handler,signal));
+ store_signal_data_for_later(data,handler,signal,info,context);
+ arch_set_pseudo_atomic_interrupted(context);
+ check_interrupt_context_or_lose(context);
+ return 1;
+ }
+ FSHOW_SIGNAL((stderr,
+ "/maybe_defer_handler(%x,%d): not deferred\n",
+ (unsigned int)handler,signal));
+ return 0;
+}
- } else {
+static void
+store_signal_data_for_later (struct interrupt_data *data, void *handler,
+ int signal,
+ siginfo_t *info, os_context_t *context)
+{
+ if (data->pending_handler)
+ lose("tried to overwrite pending interrupt handler %x with %x\n",
+ data->pending_handler, handler);
+ if (!handler)
+ lose("tried to defer null interrupt handler\n");
+ data->pending_handler = handler;
+ data->pending_signal = signal;
+ if(info)
+ memcpy(&(data->pending_info), info, sizeof(siginfo_t));
+
+ FSHOW_SIGNAL((stderr, "/store_signal_data_for_later: signal: %d\n",
+ signal));
+
+ if(!context)
+ lose("Null context");
+
+ /* the signal mask in the context (from before we were
+ * interrupted) is copied to be restored when run_deferred_handler
+ * happens. Then the usually-blocked signals are added to the mask
+ * in the context so that we are running with blocked signals when
+ * the handler returns */
+ sigcopyset(&(data->pending_mask),os_context_sigmask_addr(context));
+ sigaddset_deferrable(os_context_sigmask_addr(context));
+}
+
+static void
+maybe_now_maybe_later(int signal, siginfo_t *info, void *void_context)
+{
+ SAVE_ERRNO(signal,context,void_context);
+ struct thread *thread = arch_os_get_current_thread();
+ struct interrupt_data *data = thread->interrupt_data;
+ if(!maybe_defer_handler(interrupt_handle_now,data,signal,info,context))
interrupt_handle_now(signal, info, context);
+ RESTORE_ERRNO;
+}
+
+static void
+low_level_interrupt_handle_now(int signal, siginfo_t *info,
+ os_context_t *context)
+{
+ /* No FP control fixage needed, caller has done that. */
+ check_blockables_blocked_or_lose(0);
+ check_interrupts_enabled_or_lose(context);
+ (*interrupt_low_level_handlers[signal])(signal, info, context);
+ /* No Darwin context fixage needed, caller does that. */
+}
+
+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 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, os_context_t *context)
+{
+ struct thread *thread=arch_os_get_current_thread();
+
+ /* 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. */
+
+ /* need the context stored so it can have registers scavenged */
+ fake_foreign_function_call(context);
+
+ /* Not pending anymore. */
+ SetSymbolValue(GC_PENDING,NIL,thread);
+ SetSymbolValue(STOP_FOR_GC_PENDING,NIL,thread);
+
+ /* Consider this: in a PA section GC is requested: GC_PENDING,
+ * pseudo_atomic_interrupted and gc_blocked_deferrables are set,
+ * deferrables are blocked then pseudo_atomic_atomic is cleared,
+ * but a SIG_STOP_FOR_GC arrives before trapping to
+ * interrupt_handle_pending. Here, GC_PENDING is cleared but
+ * pseudo_atomic_interrupted is not and we go on running with
+ * pseudo_atomic_interrupted but without a pending interrupt or
+ * GC. GC_BLOCKED_DEFERRABLES is also left at 1. So let's tidy it
+ * up. */
+ if (thread->interrupt_data->gc_blocked_deferrables) {
+ FSHOW_SIGNAL((stderr,"cleaning up after gc_blocked_deferrables\n"));
+ clear_pseudo_atomic_interrupted(thread);
+ sigcopyset(os_context_sigmask_addr(context),
+ &thread->interrupt_data->pending_mask);
+ thread->interrupt_data->gc_blocked_deferrables = 0;
+ }
+
+ if(thread_state(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"));
+
+ /* 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_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);
}
-\f
+
+#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
+/* manipulate the signal context and stack such that when the handler
+ * returns, it will call function instead of whatever it was doing
+ * previously
*/
-#ifndef 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
-
-/* and similarly for the control stack guard page */
-
-boolean handle_control_stack_guard_triggered(os_context_t *context,void *addr)
-{
- /* note the os_context hackery here. When the signal handler returns,
- * it won't go back to what it was doing ... */
- if(addr>=CONTROL_STACK_GUARD_PAGE &&
- addr<(CONTROL_STACK_GUARD_PAGE+os_vm_page_size)) {
- void *function;
- /* we hit the end of the control stack. disable protection
- * temporarily so the error handler has some headroom */
- protect_control_stack_guard_page(0);
-
- function=
- &(((struct simple_fun *)
- native_pointer(SymbolFunction(CONTROL_STACK_EXHAUSTED_ERROR)))
- ->code);
-
- /* Build a stack frame showing `interrupted' so that the
- * user's backtrace makes (as much) sense (as usual) */
- build_fake_control_stack_frames(context);
- /* signal handler will "return" to this error-causing function */
- *os_context_pc_addr(context) = function;
-#ifndef LISP_FEATURE_X86
- /* this much of the calling convention is common to all
- non-x86 ports */
- *os_context_register_addr(context,reg_NARGS) = 0;
- *os_context_register_addr(context,reg_LIP) = function;
- *os_context_register_addr(context,reg_CFP) =
- current_control_frame_pointer;
+#if (defined(LISP_FEATURE_X86) || defined(LISP_FEATURE_X86_64))
+extern int *context_eflags_addr(os_context_t *context);
+#endif
+
+extern lispobj call_into_lisp(lispobj fun, lispobj *args, int nargs);
+extern void post_signal_tramp(void);
+extern void call_into_lisp_tramp(void);
+void
+arrange_return_to_lisp_function(os_context_t *context, lispobj function)
+{
+#ifndef LISP_FEATURE_WIN32
+ check_gc_signals_unblocked_or_lose
+ (os_context_sigmask_addr(context));
+#endif
+#if !(defined(LISP_FEATURE_X86) || defined(LISP_FEATURE_X86_64))
+ void * fun=native_pointer(function);
+ void *code = &(((struct simple_fun *) fun)->code);
+#endif
+
+ /* Build a stack frame showing `interrupted' so that the
+ * user's backtrace makes (as much) sense (as usual) */
+
+ /* fp state is saved and restored by call_into_lisp */
+ /* FIXME: errno is not restored, but since current uses of this
+ * function only call Lisp code that signals an error, it's not
+ * much of a problem. In other words, running out of the control
+ * stack between a syscall and (GET-ERRNO) may clobber errno if
+ * something fails during signalling or in the handler. But I
+ * can't see what can go wrong as long as there is no CONTINUE
+ * like restart on them. */
+#ifdef LISP_FEATURE_X86
+ /* Suppose the existence of some function that saved all
+ * registers, called call_into_lisp, then restored GP registers and
+ * returned. It would look something like this:
+
+ push ebp
+ mov ebp esp
+ pushfl
+ pushal
+ push $0
+ push $0
+ pushl {address of function to call}
+ call 0x8058db0 <call_into_lisp>
+ 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);
+
+#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-13) = 0; /* arg array */
+ *(sp-12) = 0; /* no. args */
+ /* this order matches that used in POPAD */
+ *(sp-11)=*os_context_register_addr(context,reg_EDI);
+ *(sp-10)=*os_context_register_addr(context,reg_ESI);
+
+ *(sp-9)=*os_context_register_addr(context,reg_ESP)-8;
+ /* POPAD ignores the value of ESP: */
+ *(sp-8)=0;
+ *(sp-7)=*os_context_register_addr(context,reg_EBX);
+
+ *(sp-6)=*os_context_register_addr(context,reg_EDX);
+ *(sp-5)=*os_context_register_addr(context,reg_ECX);
+ *(sp-4)=*os_context_register_addr(context,reg_EAX);
+ *(sp-3)=*context_eflags_addr(context);
+ *(sp-2)=*os_context_register_addr(context,reg_EBP);
+ *(sp-1)=*os_context_pc_addr(context);
+
+#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
+
+#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);
+#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)call_into_lisp;
+ *os_context_register_addr(context,reg_RCX) = 0;
+ *os_context_register_addr(context,reg_RBP) = (os_context_register_t)(sp-2);
+ *os_context_register_addr(context,reg_RSP) = (os_context_register_t)(sp-18);
+#else
+ /* this much of the calling convention is common to all
+ non-x86 ports */
+ *os_context_pc_addr(context) = (os_context_register_t)(unsigned long)code;
+ *os_context_register_addr(context,reg_NARGS) = 0;
+ *os_context_register_addr(context,reg_LIP) =
+ (os_context_register_t)(unsigned long)code;
+ *os_context_register_addr(context,reg_CFP) =
+ (os_context_register_t)(unsigned long)current_control_frame_pointer;
#endif
#ifdef ARCH_HAS_NPC_REGISTER
- *os_context_npc_addr(context) =
- 4 + *os_context_pc_addr(context);
+ *os_context_npc_addr(context) =
+ 4 + *os_context_pc_addr(context);
#endif
#ifdef LISP_FEATURE_SPARC
- /* Bletch. This is a feature of the SPARC calling convention,
- which sadly I'm not going to go into in large detail here,
- as I don't know it well enough. Suffice to say that if the
- line
+ *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));
+}
- (INST MOVE CODE-TN FUNCTION)
+/* 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));
+}
- in compiler/sparc/call.lisp is changed, then this bit can
- probably go away. -- CSR, 2002-07-24 */
- *os_context_register_addr(context,reg_CODE) =
- function - SIMPLE_FUN_CODE_OFFSET;
-#endif
- return 1;
+void lower_thread_control_stack_guard_page(struct thread *th)
+{
+ protect_control_stack_guard_page(0, th);
+ protect_control_stack_return_guard_page(1, th);
+ th->control_stack_guard_page_protected = NIL;
+ fprintf(stderr, "INFO: Control stack guard page unprotected\n");
+}
+
+void reset_thread_control_stack_guard_page(struct thread *th)
+{
+ memset(CONTROL_STACK_GUARD_PAGE(th), 0, os_vm_page_size);
+ protect_control_stack_guard_page(1, th);
+ protect_control_stack_return_guard_page(0, th);
+ th->control_stack_guard_page_protected = T;
+ fprintf(stderr, "INFO: Control stack guard page reprotected\n");
+}
+
+/* Called from the REPL, too. */
+void reset_control_stack_guard_page(void)
+{
+ struct thread *th=arch_os_get_current_thread();
+ if (th->control_stack_guard_page_protected == NIL) {
+ reset_thread_control_stack_guard_page(th);
}
- else return 0;
}
-#ifndef __i386__
-/* This function gets called from the SIGSEGV (for e.g. Linux or
- * OpenBSD) or SIGBUS (for e.g. FreeBSD) handler. Here we check
- * whether the signal was due to treading on the mprotect()ed zone -
- * and if so, arrange for a GC to happen. */
+void lower_control_stack_guard_page(void)
+{
+ lower_thread_control_stack_guard_page(arch_os_get_current_thread());
+}
+
boolean
-interrupt_maybe_gc(int signal, siginfo_t *info, void *void_context)
-{
- os_context_t *context=(os_context_t *) void_context;
-
- if (!foreign_function_call_active
-#ifndef GENCGC /* since GENCGC has its own way to record trigger */
- && gc_trigger_hit(signal, info, context)
-#endif
- ) {
-#ifndef GENCGC /* since GENCGC has its own way to record trigger */
- clear_auto_gc_trigger();
-#endif
-
- if (arch_pseudo_atomic_atomic(context)) {
- /* don't GC during an atomic operation. Instead, copy the
- * signal mask somewhere safe. interrupt_handle_pending
- * will detect pending_signal==0 and know to do a GC with the
- * signal context instead of calling a Lisp-level handler */
- maybe_gc_pending = 1;
- if (pending_signal == 0) {
- /* FIXME: This copy-pending_mask-then-sigaddset_blockable
- * idiom occurs over and over. It should be factored out
- * into a function with a descriptive name. */
- memcpy(&pending_mask,
- os_context_sigmask_addr(context),
- sizeof(sigset_t));
- sigaddset_blockable(os_context_sigmask_addr(context));
- }
- arch_set_pseudo_atomic_interrupted(context);
- }
- else {
- lispobj *old_free_space=current_dynamic_space;
- fake_foreign_function_call(context);
- funcall0(SymbolFunction(MAYBE_GC));
- undo_fake_foreign_function_call(context);
- if(current_dynamic_space==old_free_space)
- /* MAYBE-GC (as the name suggest) might not. If it
- * doesn't, it won't reset the GC trigger either, so we
- * have to do it ourselves. Put it near the end of
- * dynamic space so we're not running into it continually
- */
- set_auto_gc_trigger(DYNAMIC_SPACE_SIZE
- -(u32)os_vm_page_size);
- }
- return 1;
- } else {
- return 0;
+handle_guard_page_triggered(os_context_t *context,os_vm_address_t addr)
+{
+ struct thread *th=arch_os_get_current_thread();
+
+ if(addr >= CONTROL_STACK_HARD_GUARD_PAGE(th) &&
+ addr < CONTROL_STACK_HARD_GUARD_PAGE(th) + os_vm_page_size) {
+ lose("Control stack exhausted");
}
-}
+ else if(addr >= CONTROL_STACK_GUARD_PAGE(th) &&
+ addr < CONTROL_STACK_GUARD_PAGE(th) + os_vm_page_size) {
+ /* We hit the end of the control stack: disable guard page
+ * protection so the error handler has some headroom, protect the
+ * previous page so that we can catch returns from the guard page
+ * and restore it. */
+ if (th->control_stack_guard_page_protected == NIL)
+ lose("control_stack_guard_page_protected NIL");
+ lower_control_stack_guard_page();
+#ifdef LISP_FEATURE_C_STACK_IS_CONTROL_STACK
+ /* For the unfortunate case, when the control stack is
+ * exhausted in a signal handler. */
+ unblock_signals_in_context_and_maybe_warn(context);
#endif
+ 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;
+}
\f
/*
* noise to install handlers
*/
-/*
- * what low-level signal handlers looked like before
- * undoably_install_low_level_interrupt_handler() got involved
+#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
*/
-struct low_level_signal_handler_state {
- int was_modified;
- void (*handler)(int, siginfo_t*, void*);
-} old_low_level_signal_handler_states[NSIG];
+static volatile int sigaction_nodefer_works = -1;
-void
-uninstall_low_level_interrupt_handlers_atexit(void)
+#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)
{
- int signal;
- for (signal = 0; signal < NSIG; ++signal) {
- struct low_level_signal_handler_state
- *old_low_level_signal_handler_state =
- old_low_level_signal_handler_states + signal;
- if (old_low_level_signal_handler_state->was_modified) {
- struct sigaction sa;
- sa.sa_sigaction = old_low_level_signal_handler_state->handler;
- sigemptyset(&sa.sa_mask);
- sa.sa_flags = SA_SIGINFO | SA_RESTART;
- sigaction(signal, &sa, NULL);
- }
+ 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;
+}
+
+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
+
+static void
+unblock_me_trampoline(int signal, siginfo_t *info, void *void_context)
+{
+ SAVE_ERRNO(signal,context,void_context);
+ sigset_t unblock;
+
+ sigemptyset(&unblock);
+ sigaddset(&unblock, signal);
+ thread_sigmask(SIG_UNBLOCK, &unblock, 0);
+ interrupt_handle_now(signal, info, context);
+ RESTORE_ERRNO;
+}
+
+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;
}
-/* Undoably install a special low-level handler for signal; or if
- * handler is SIG_DFL, remove any special handling for signal.
- *
- * The "undoably" aspect is because we also arrange with atexit() for
- * the handler to be restored to its old value. This is for tidiness:
- * it shouldn't matter much ordinarily, but it does remove a window
- * where e.g. memory fault signals (SIGSEGV or SIGBUS, which in
- * ordinary operation of SBCL are sent to the generational garbage
- * collector, then possibly onward to Lisp code) or SIGINT (which is
- * ordinarily passed to Lisp code) could otherwise be handled
- * bizarrely/brokenly because the Lisp code would try to deal with
- * them using machinery (like stream output buffers) which has already
- * been dismantled. */
void
undoably_install_low_level_interrupt_handler (int signal,
- void handler(int,
- siginfo_t*,
- void*))
+ interrupt_handler_t handler)
{
struct sigaction sa;
- struct low_level_signal_handler_state *old_low_level_signal_handler_state =
- old_low_level_signal_handler_states + signal;
if (0 > signal || signal >= NSIG) {
- lose("bad signal number %d", signal);
+ lose("bad signal number %d\n", signal);
}
- sa.sa_sigaction = handler;
- sigemptyset(&sa.sa_mask);
- sigaddset_blockable(&sa.sa_mask);
- sa.sa_flags = SA_SIGINFO | SA_RESTART;
+ 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;
+
+ 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
- /* Signal handlers are run on the control stack, so if it is exhausted
- * we had better use an alternate stack for whatever signal tells us
- * we've exhausted it */
- if(signal==SIG_MEMORY_FAULT) {
- stack_t sigstack;
- sigstack.ss_sp=(void *) ALTERNATE_SIGNAL_STACK_START;
- sigstack.ss_flags=0;
- sigstack.ss_size = SIGSTKSZ;
- sigaltstack(&sigstack,0);
- sa.sa_flags|=SA_ONSTACK;
- }
-#endif
-
- /* In the case of interrupt handlers which are modified more than
- * once, we only save the original unmodified copy. */
- if (!old_low_level_signal_handler_state->was_modified) {
- struct sigaction *old_handler =
- (struct sigaction*) &old_low_level_signal_handler_state->handler;
- old_low_level_signal_handler_state->was_modified = 1;
- sigaction(signal, &sa, old_handler);
- } else {
- sigaction(signal, &sa, NULL);
- }
+ if((signal==SIG_MEMORY_FAULT))
+ sa.sa_flags |= SA_ONSTACK;
+#endif
+ sigaction(signal, &sa, NULL);
interrupt_low_level_handlers[signal] =
- (ARE_SAME_HANDLER(handler, SIG_DFL) ? 0 : handler);
+ (ARE_SAME_HANDLER(handler, SIG_DFL) ? 0 : handler);
}
+#endif
/* This is called from Lisp. */
unsigned long
-install_handler(int signal, void handler(int, siginfo_t*, void*))
+install_handler(int signal, void handler(int, siginfo_t*, os_context_t*))
{
+#ifndef LISP_FEATURE_WIN32
struct sigaction sa;
- sigset_t old, new;
+ sigset_t old;
union interrupt_handler oldhandler;
FSHOW((stderr, "/entering POSIX install_handler(%d, ..)\n", signal));
- sigemptyset(&new);
- sigaddset(&new, signal);
- sigprocmask(SIG_BLOCK, &new, &old);
+ block_blockable_signals(0, &old);
- sigemptyset(&new);
- sigaddset_blockable(&new);
-
- FSHOW((stderr, "/interrupt_low_level_handlers[signal]=%d\n",
- interrupt_low_level_handlers[signal]));
+ FSHOW((stderr, "/interrupt_low_level_handlers[signal]=%x\n",
+ (unsigned int)interrupt_low_level_handlers[signal]));
if (interrupt_low_level_handlers[signal]==0) {
- if (ARE_SAME_HANDLER(handler, SIG_DFL) ||
- ARE_SAME_HANDLER(handler, SIG_IGN)) {
- sa.sa_sigaction = handler;
- } else if (sigismember(&new, signal)) {
- sa.sa_sigaction = maybe_now_maybe_later;
- } else {
- sa.sa_sigaction = interrupt_handle_now_handler;
- }
-
- sigemptyset(&sa.sa_mask);
- sigaddset_blockable(&sa.sa_mask);
- sa.sa_flags = SA_SIGINFO | SA_RESTART;
-
- sigaction(signal, &sa, NULL);
+ if (ARE_SAME_HANDLER(handler, SIG_DFL) ||
+ ARE_SAME_HANDLER(handler, SIG_IGN))
+ sa.sa_sigaction = (void (*)(int, siginfo_t*, void*))handler;
+ else if (sigismember(&deferrable_sigset, signal))
+ sa.sa_sigaction = maybe_now_maybe_later;
+ else if (!sigaction_nodefer_works &&
+ !sigismember(&blockable_sigset, signal))
+ sa.sa_sigaction = unblock_me_trampoline;
+ else
+ sa.sa_sigaction = interrupt_handle_now_handler;
+
+ sigcopyset(&sa.sa_mask, &blockable_sigset);
+ sa.sa_flags = SA_SIGINFO | SA_RESTART |
+ (sigaction_nodefer_works ? SA_NODEFER : 0);
+ sigaction(signal, &sa, NULL);
}
oldhandler = interrupt_handlers[signal];
interrupt_handlers[signal].c = handler;
- sigprocmask(SIG_SETMASK, &old, 0);
+ thread_sigmask(SIG_SETMASK, &old, 0);
FSHOW((stderr, "/leaving POSIX install_handler(%d, ..)\n", signal));
return (unsigned long)oldhandler.lisp;
+#else
+ /* Probably-wrong Win32 hack */
+ return 0;
+#endif
+}
+
+/* This must not go through lisp as it's allowed anytime, even when on
+ * the altstack. */
+void
+sigabrt_handler(int signal, siginfo_t *info, os_context_t *context)
+{
+ lose("SIGABRT received.\n");
}
void
interrupt_init(void)
{
+#ifndef LISP_FEATURE_WIN32
int i;
-
SHOW("entering interrupt_init()");
-
- /* Set up for recovery from any installed low-level handlers. */
- atexit(&uninstall_low_level_interrupt_handlers_atexit);
+ 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++) {
interrupt_handlers[i].c =
- /* (The cast here blasts away the distinction between
- * SA_SIGACTION-style three-argument handlers and
- * signal(..)-style one-argument handlers, which is OK
- * because it works to call the 1-argument form where the
- * 3-argument form is expected.) */
- (void (*)(int, siginfo_t*, void*))SIG_DFL;
+ /* (The cast here blasts away the distinction between
+ * SA_SIGACTION-style three-argument handlers and
+ * signal(..)-style one-argument handlers, which is OK
+ * because it works to call the 1-argument form where the
+ * 3-argument form is expected.) */
+ (void (*)(int, siginfo_t*, os_context_t*))SIG_DFL;
}
-
+ undoably_install_low_level_interrupt_handler(SIGABRT, sigabrt_handler);
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 (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);
+ unblock_gc_signals(0, 0);
+ 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);
+ }
}