* files for more information.
*/
-#include <stdio.h>
+/* 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 <stdio.h>
+#include <stdlib.h>
+#include <string.h>
#include <signal.h>
-#ifdef mach /* KLUDGE: #ifdef on lowercase symbols? Ick. -- WHN 19990904 */
-#ifdef mips
-#include <mips/cpu.h>
-#endif
-#endif
+#include <sys/types.h>
+#include <sys/wait.h>
+#include "sbcl.h"
#include "runtime.h"
#include "arch.h"
-#include "sbcl.h"
#include "os.h"
#include "interrupt.h"
#include "globals.h"
#include "alloc.h"
#include "dynbind.h"
#include "interr.h"
+#include "genesis/fdefn.h"
+#include "genesis/simple-fun.h"
+
+
+
+void run_deferred_handler(struct interrupt_data *data, void *v_context) ;
+static void store_signal_data_for_later (struct interrupt_data *data,
+ void *handler, int signal,
+ siginfo_t *info,
+ os_context_t *context);
+boolean interrupt_maybe_gc_int(int signal, siginfo_t *info, void *v_context);
+
+extern volatile lispobj all_threads_lock;
+
+/*
+ * This is a workaround for some slightly silly Linux/GNU Libc
+ * behaviour: glibc defines sigset_t to support 1024 signals, which is
+ * more than the kernel. This is usually not a problem, but becomes
+ * one when we want to save a signal mask from a ucontext, and restore
+ * it later into another ucontext: the ucontext is allocated on the
+ * stack by the kernel, so copying a libc-sized sigset_t into it will
+ * overflow and cause other data on the stack to be corrupted */
+
+#define REAL_SIGSET_SIZE_BYTES ((NSIG/8))
void sigaddset_blockable(sigset_t *s)
{
sigaddset(s, SIGPIPE);
sigaddset(s, SIGALRM);
sigaddset(s, SIGURG);
+ sigaddset(s, SIGFPE);
sigaddset(s, SIGTSTP);
sigaddset(s, SIGCHLD);
sigaddset(s, SIGIO);
sigaddset(s, SIGWINCH);
sigaddset(s, SIGUSR1);
sigaddset(s, SIGUSR2);
+#ifdef LISP_FEATURE_SB_THREAD
+ sigaddset(s, SIG_STOP_FOR_GC);
+ sigaddset(s, SIG_INTERRUPT_THREAD);
+#endif
}
/* When we catch an internal error, should we pass it back to Lisp to
* becomes 'yes'.) */
boolean internal_errors_enabled = 0;
-os_context_t *lisp_interrupt_contexts[MAX_INTERRUPTS];
+struct interrupt_data * global_interrupt_data;
-/* 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 */
+/* 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 reset_signal_mask ()
+{
+ sigset_t new;
+ sigemptyset(&new);
+ sigprocmask(SIG_SETMASK,&new,0);
+}
-void (*interrupt_low_level_handlers[NSIG]) (int, siginfo_t*, void*) = {0};
-union interrupt_handler interrupt_handlers[NSIG];
-/* signal number, siginfo_t, and old mask information for pending signal
- *
- * pending_signal=0 when there is no pending signal. */
-static int pending_signal = 0;
-static siginfo_t pending_info;
-static sigset_t pending_mask;
-static boolean maybe_gc_pending = 0;
\f
/*
* utility routines used by various signal handlers
*/
-void
-fake_foreign_function_call(os_context_t *context)
+void
+build_fake_control_stack_frames(struct thread *th,os_context_t *context)
{
- int context_index;
-#ifndef __i386__
+#ifndef LISP_FEATURE_C_STACK_IS_CONTROL_STACK
+
lispobj oldcont;
-#endif
- /* Get current Lisp state from context. */
-#ifdef reg_ALLOC
- dynamic_space_free_pointer =
- (lispobj *)(*os_context_register_addr(context, reg_ALLOC));
-#ifdef alpha
- if ((long)dynamic_space_free_pointer & 1) {
- lose("dead in fake_foreign_function_call, context = %x", context);
- }
-#endif
-#endif
-#ifdef reg_BSP
- current_binding_stack_pointer =
- (lispobj *)(*os_context_register_addr(context, reg_BSP));
-#endif
+ /* Build a fake stack frame or frames */
-#ifndef __i386__
- /* Build a fake stack frame. */
current_control_frame_pointer =
(lispobj *)(*os_context_register_addr(context, reg_CSP));
if ((lispobj *)(*os_context_register_addr(context, reg_CFP))
== current_control_frame_pointer) {
/* There is a small window during call where the callee's
* frame isn't built yet. */
- if (LowtagOf(*os_context_register_addr(context, reg_CODE))
- == type_FunctionPointer) {
+ if (lowtag_of(*os_context_register_addr(context, reg_CODE))
+ == FUN_POINTER_LOWTAG) {
/* We have called, but not built the new frame, so
* build it for them. */
current_control_frame_pointer[0] =
oldcont = (lispobj)(*os_context_register_addr(context, reg_OCFP));
}
}
- /* ### We can't tell whether we are still in the caller if it had
- * to reg_ALLOCate the stack frame due to stack arguments. */
- /* ### Can anything strange happen during return? */
+ /* We can't tell whether we are still in the caller if it had to
+ * allocate a stack frame due to stack arguments. */
+ /* This observation provoked some past CMUCL maintainer to ask
+ * "Can anything strange happen during return?" */
else {
/* normal case */
oldcont = (lispobj)(*os_context_register_addr(context, reg_CFP));
current_control_frame_pointer[2] =
(lispobj)(*os_context_register_addr(context, reg_CODE));
#endif
+}
+
+void
+fake_foreign_function_call(os_context_t *context)
+{
+ int context_index;
+ struct thread *thread=arch_os_get_current_thread();
+
+ /* Get current Lisp state from context. */
+#ifdef reg_ALLOC
+ dynamic_space_free_pointer =
+ (lispobj *)(*os_context_register_addr(context, reg_ALLOC));
+#if defined(LISP_FEATURE_ALPHA)
+ if ((long)dynamic_space_free_pointer & 1) {
+ lose("dead in fake_foreign_function_call, context = %x", context);
+ }
+#endif
+#endif
+#ifdef reg_BSP
+ current_binding_stack_pointer =
+ (lispobj *)(*os_context_register_addr(context, reg_BSP));
+#endif
+
+ build_fake_control_stack_frames(thread,context);
/* Do dynamic binding of the active interrupt context index
* and save the context in the context array. */
- context_index = 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", 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 */
foreign_function_call_active = 1;
}
+/* 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);
/* going back into Lisp */
foreign_function_call_active = 0;
- /* Undo dynamic binding. */
- /* ### Do I really need to unbind_to_here()? */
- /* FIXME: Is this to undo the binding of
- * FREE_INTERRUPT_CONTEXT_INDEX? If so, we should say so. And
- * perhaps yes, unbind_to_here() really would be clearer and less
- * fragile.. */
- unbind();
+ /* Undo dynamic binding of FREE_INTERRUPT_CONTEXT_INDEX */
+ unbind(thread);
#ifdef reg_ALLOC
/* Put the dynamic space free pointer back into the context. */
if (internal_errors_enabled) {
SHOW("in interrupt_internal_error");
-#if QSHOW
+#ifdef 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. */
* 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);
+ 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 */
-
void
interrupt_handle_pending(os_context_t *context)
{
-#ifndef __i386__
- boolean were_in_lisp = !foreign_function_call_active;
-#endif
-
- SetSymbolValue(INTERRUPT_PENDING, NIL);
-
- if (maybe_gc_pending) {
- maybe_gc_pending = 0;
-#ifndef __i386__
- if (were_in_lisp)
-#endif
- {
- fake_foreign_function_call(context);
- }
- funcall0(SymbolFunction(MAYBE_GC));
-#ifndef __i386__
- if (were_in_lisp)
-#endif
- {
- undo_fake_foreign_function_call(context);
- }
- }
-
- /* 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. */
- memcpy(os_context_sigmask_addr(context), &pending_mask, sizeof(sigset_t));
- 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);
- }
+ struct thread *thread;
+ struct interrupt_data *data;
+
+ thread=arch_os_get_current_thread();
+ data=thread->interrupt_data;
+ /* FIXME I'm not altogether sure this is appropriate if we're
+ * here as the result of a pseudo-atomic */
+ 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 */
+
+ memcpy(os_context_sigmask_addr(context), &data->pending_mask,
+ REAL_SIGSET_SIZE_BYTES);
+
+ 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);
}
\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)
{
os_context_t *context = (os_context_t*)void_context;
-#ifndef __i386__
+ struct thread *thread=arch_os_get_current_thread();
+#if !defined(LISP_FEATURE_X86) && !defined(LISP_FEATURE_X86_64)
boolean were_in_lisp;
#endif
union interrupt_handler handler;
- /* FIXME: The CMU CL we forked off of had this Linux-only
- * operation here. Newer CMU CLs (e.g. 18c) have hairier
- * Linux/i386-only logic here. SBCL seems to be more reliable
- * without anything here. However, if we start supporting code
- * which sets the rounding mode, then we may want to do something
- * special to force the rounding mode back to some standard value
- * here, so that ISRs can have a standard environment. (OTOH, if
- * rounding modes are under user control, then perhaps we should
- * leave this up to the user.)
- *
- * In the absence of a test case to show that this is really a
- * problem, we just suppress this code completely (just like the
- * parallel code in maybe_now_maybe_later).
- * #ifdef __linux__
- * SET_FPU_CONTROL_WORD(context->__fpregs_mem.cw);
- * #endif */
-
- handler = interrupt_handlers[signal];
+#ifdef LISP_FEATURE_LINUX
+ /* Under Linux on some architectures, we appear to have to restore
+ the FPU control word from the context, as after the signal is
+ delivered we appear to have a null FPU control word. */
+ os_restore_fp_control(context);
+#endif
+ handler = thread->interrupt_data->interrupt_handlers[signal];
if (ARE_SAME_HANDLER(handler.c, SIG_IGN)) {
return;
}
-
-#ifndef __i386__
+
+#if !defined(LISP_FEATURE_X86) && !defined(LISP_FEATURE_X86_64)
were_in_lisp = !foreign_function_call_active;
if (were_in_lisp)
#endif
* support decides to pass on it. */
lose("no handler for signal %d in interrupt_handle_now(..)", signal);
- } else if (LowtagOf(handler.lisp) == type_FunctionPointer) {
+ } else if (lowtag_of(handler.lisp) == FUN_POINTER_LOWTAG) {
+ /* Once we've decided what to do about contexts in a
+ * return-elsewhere world (the original context will no longer
+ * be available; should we copy it or was nobody using it anyway?)
+ * then we should convert this to return-elsewhere */
+
+ /* CMUCL comment said "Allocate the SAPs while the interrupts
+ * are still disabled.". I (dan, 2003.08.21) assume this is
+ * because we're not in pseudoatomic and allocation shouldn't
+ * be interrupted. In which case it's no longer an issue as
+ * all our allocation from C now goes through a PA wrapper,
+ * but still, doesn't hurt */
- /* Allocate the SAPs while the interrupts are still disabled.
- * (FIXME: Why? This is the way it was done in CMU CL, and it
- * even had the comment noting that this is the way it was
- * done, but no motivation..) */
lispobj info_sap,context_sap = alloc_sap(context);
info_sap = alloc_sap(info);
/* Allow signals again. */
(*handler.c)(signal, info, void_context);
}
-#ifndef __i386__
+#if !defined(LISP_FEATURE_X86) && !defined(LISP_FEATURE_X86_64)
if (were_in_lisp)
#endif
{
- undo_fake_foreign_function_call(context);
+ undo_fake_foreign_function_call(context); /* block signals again */
}
#ifdef QSHOW_SIGNALS
#endif
}
-static void
-maybe_now_maybe_later(int signal, siginfo_t *info, void *void_context)
-{
- os_context_t *context = (os_context_t*)void_context;
+/* 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 */
- /* FIXME: See Debian cmucl 2.4.17, and mail from DTC on the CMU CL
- * mailing list 23 Oct 1999, for changes in FPU handling at
- * interrupt time which should be ported into SBCL. Also see the
- * analogous logic at the head of interrupt_handle_now for
- * more related FIXME stuff.
- *
- * For now, we just suppress this code completely.
- * #ifdef __linux__
- * SET_FPU_CONTROL_WORD(context->__fpregs_mem.cw);
- * #endif */
-
- /* see comments at top of code/signal.lisp for what's going on here
- * with INTERRUPTS_ENABLED/INTERRUPT_HANDLE_NOW
- */
- if (SymbolValue(INTERRUPTS_ENABLED) == NIL) {
-
- /* FIXME: This code is exactly the same as the code in the
- * other leg of the if(..), and should be factored out into
- * a shared function. */
- pending_signal = signal;
- memcpy(&pending_info, info, sizeof(siginfo_t));
- memcpy(&pending_mask,
- os_context_sigmask_addr(context),
- sizeof(sigset_t));
- sigaddset_blockable(os_context_sigmask_addr(context));
- SetSymbolValue(INTERRUPT_PENDING, T);
+void
+run_deferred_handler(struct interrupt_data *data, void *v_context) {
+ (*(data->pending_handler))
+ (data->pending_signal,&(data->pending_info), v_context);
+ data->pending_handler=0;
+}
- } else if (
-#ifndef __i386__
- (!foreign_function_call_active) &&
+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();
+ if (SymbolValue(INTERRUPTS_ENABLED,thread) == NIL) {
+ store_signal_data_for_later(data,handler,signal,info,context);
+ SetSymbolValue(INTERRUPT_PENDING, T,thread);
+ return 1;
+ }
+ /* a slightly confusing test. arch_pseudo_atomic_atomic() doesn't
+ * 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)
+ (!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,
+ arch_pseudo_atomic_atomic(context)) {
+ store_signal_data_for_later(data,handler,signal,info,context);
+ arch_set_pseudo_atomic_interrupted(context);
+ return 1;
+ }
+ return 0;
+}
+static void
+store_signal_data_for_later (struct interrupt_data *data, void *handler,
+ int signal,
+ siginfo_t *info, os_context_t *context)
+{
+ data->pending_handler = handler;
+ data->pending_signal = signal;
+ if(info)
+ memcpy(&(data->pending_info), info, sizeof(siginfo_t));
+ if(context) {
+ /* the signal mask in the context (from before we were
+ * interrupted) is copied to be restored when
+ * run_deferred_handler happens. Then the usually-blocked
+ * signals are added to the mask in the context so that we are
+ * running with blocked signals when the handler returns */
+ sigemptyset(&(data->pending_mask));
+ memcpy(&(data->pending_mask),
os_context_sigmask_addr(context),
- sizeof(sigset_t));
+ REAL_SIGSET_SIZE_BYTES);
sigaddset_blockable(os_context_sigmask_addr(context));
+ } else {
+ /* this is also called from gencgc alloc(), in which case
+ * there has been no signal and is therefore no context. */
+ sigset_t new;
+ sigemptyset(&new);
+ sigaddset_blockable(&new);
+ sigprocmask(SIG_BLOCK,&new,&(data->pending_mask));
+ }
+}
- arch_set_pseudo_atomic_interrupted(context);
- } else {
- interrupt_handle_now(signal, info, 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
+}
+
+#ifdef LISP_FEATURE_SB_THREAD
+void
+sig_stop_for_gc_handler(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;
+ sigset_t ss;
+ int i;
+
+ if(maybe_defer_handler(sig_stop_for_gc_handler,data,
+ signal,info,context)) {
+ return;
}
+ /* need the context stored so it can have registers scavenged */
+ fake_foreign_function_call(context);
+
+ sigemptyset(&ss);
+ for(i=1;i<NSIG;i++) sigaddset(&ss,i); /* Block everything. */
+ sigprocmask(SIG_BLOCK,&ss,0);
+
+ /* 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 */
+ mark_dead_threads();
+
+ thread->state=STATE_STOPPED;
+
+ sigemptyset(&ss); sigaddset(&ss,SIG_STOP_FOR_GC);
+ sigwaitinfo(&ss,0);
+
+ 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);
+ interrupt_handle_now(signal, info, context);
+#ifdef LISP_FEATURE_DARWIN
+ DARWIN_FIX_CONTEXT(context);
+#endif
+}
+
/*
* stuff to detect and handle hitting the GC trigger
*/
-#ifndef INTERNAL_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{
- lispobj *badaddr=(lispobj *)arch_get_bad_addr(signal,
- info,
- context);
+ void *badaddr=arch_get_bad_addr(signal,info,context);
+ return (badaddr >= (void *)current_auto_gc_trigger &&
+ badaddr <((void *)current_dynamic_space + DYNAMIC_SPACE_SIZE));
+ }
+}
+#endif
+
+/* manipulate the signal context and stack such that when the handler
+ * returns, it will call function instead of whatever it was doing
+ * previously
+ */
+
+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)
+{
+#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) */
+#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
+ pushad
+ push $0
+ push $0
+ pushl {address of function to call}
+ call 0x8058db0 <call_into_lisp>
+ addl $12,%esp
+ popa
+ leave
+ ret
+
+ * What we do here is set up the stack that call_into_lisp would
+ * expect to see if it had been called by this code, and frob the
+ * signal context so that signal return goes directly to call_into_lisp,
+ * and when that function (and the lisp function it invoked) returns,
+ * it returns to the second half of this imaginary function which
+ * restores all registers and returns to C
+
+ * For this to work, the latter part of the imaginary function
+ * must obviously exist in reality. That would be post_signal_tramp
+ */
+
+ u32 *sp=(u32 *)*os_context_register_addr(context,reg_ESP);
+
+ *(sp-14) = post_signal_tramp; /* return address for call_into_lisp */
+ *(sp-13) = function; /* args for call_into_lisp : function*/
+ *(sp-12) = 0; /* arg array */
+ *(sp-11) = 0; /* no. args */
+ /* this order matches that used in POPAD */
+ *(sp-10)=*os_context_register_addr(context,reg_EDI);
+ *(sp-9)=*os_context_register_addr(context,reg_ESI);
+
+ *(sp-8)=*os_context_register_addr(context,reg_ESP)-8;
+ *(sp-7)=0;
+ *(sp-6)=*os_context_register_addr(context,reg_EBX);
+
+ *(sp-5)=*os_context_register_addr(context,reg_EDX);
+ *(sp-4)=*os_context_register_addr(context,reg_ECX);
+ *(sp-3)=*os_context_register_addr(context,reg_EAX);
+ *(sp-2)=*os_context_register_addr(context,reg_EBP);
+ *(sp-1)=*os_context_pc_addr(context);
+
+#elif defined(LISP_FEATURE_X86_64)
+ u64 *sp=(u64 *)*os_context_register_addr(context,reg_RSP);
+ *(sp-19) = post_signal_tramp; /* return address for call_into_lisp */
+
+ *(sp-18)=*os_context_register_addr(context,reg_R15);
+ *(sp-17)=*os_context_register_addr(context,reg_R14);
+ *(sp-16)=*os_context_register_addr(context,reg_R13);
+ *(sp-15)=*os_context_register_addr(context,reg_R12);
+ *(sp-14)=*os_context_register_addr(context,reg_R11);
+ *(sp-13)=*os_context_register_addr(context,reg_R10);
+ *(sp-12)=*os_context_register_addr(context,reg_R9);
+ *(sp-11)=*os_context_register_addr(context,reg_R8);
+ *(sp-10)=*os_context_register_addr(context,reg_RDI);
+ *(sp-9)=*os_context_register_addr(context,reg_RSI);
+ *(sp-8)=*os_context_register_addr(context,reg_RSP)-16;
+ *(sp-7)=0;
+ *(sp-6)=*os_context_register_addr(context,reg_RBX);
+ *(sp-5)=*os_context_register_addr(context,reg_RDX);
+ *(sp-4)=*os_context_register_addr(context,reg_RCX);
+ *(sp-3)=*os_context_register_addr(context,reg_RAX);
+ *(sp-2)=*os_context_register_addr(context,reg_RBP);
+ *(sp-1)=*os_context_pc_addr(context);
+
+ *os_context_register_addr(context,reg_RDI) = 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
- return (badaddr >= current_auto_gc_trigger &&
- badaddr < current_dynamic_space + DYNAMIC_SPACE_SIZE);
+#ifdef LISP_FEATURE_X86
+ *os_context_pc_addr(context) = call_into_lisp;
+ *os_context_register_addr(context,reg_ECX) = 0;
+ *os_context_register_addr(context,reg_EBP) = sp-2;
+#ifdef __NetBSD__
+ *os_context_register_addr(context,reg_UESP) = sp-14;
+#else
+ *os_context_register_addr(context,reg_ESP) = sp-14;
+#endif
+#elif defined(LISP_FEATURE_X86_64)
+ *os_context_pc_addr(context) = call_into_lisp;
+ *os_context_register_addr(context,reg_RCX) = 0;
+ *os_context_register_addr(context,reg_RBP) = sp-2;
+ *os_context_register_addr(context,reg_RSP) = sp-19;
+#else
+ /* this much of the calling convention is common to all
+ non-x86 ports */
+ *os_context_pc_addr(context) = code;
+ *os_context_register_addr(context,reg_NARGS) = 0;
+ *os_context_register_addr(context,reg_LIP) = code;
+ *os_context_register_addr(context,reg_CFP) =
+ current_control_frame_pointer;
+#endif
+#ifdef ARCH_HAS_NPC_REGISTER
+ *os_context_npc_addr(context) =
+ 4 + *os_context_pc_addr(context);
+#endif
+#ifdef LISP_FEATURE_SPARC
+ *os_context_register_addr(context,reg_CODE) =
+ fun + FUN_POINTER_LOWTAG;
+#endif
+}
+
+#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);
+ struct thread *th=arch_os_get_current_thread();
+ struct interrupt_data *data=
+ th ? th->interrupt_data : global_interrupt_data;
+ if(maybe_defer_handler(interrupt_thread_handler,data,num,info,context)){
+ return ;
}
+ arrange_return_to_lisp_function(context,info->si_value.sival_int);
}
+
+void thread_exit_handler(int num, siginfo_t *info, void *v_context)
+{ /* called when a child thread exits */
+ mark_dead_threads();
+}
+
#endif
-#ifndef __i386__
-/* This function gets called from the SIGSEGV (for e.g. Linux or
+/* 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));
+}
+
+boolean handle_guard_page_triggered(os_context_t *context,void *addr){
+ struct thread *th=arch_os_get_current_thread();
+
+ /* note the os_context hackery here. When the signal handler returns,
+ * it won't go back to what it was doing ... */
+ if(addr >= CONTROL_STACK_GUARD_PAGE(th) &&
+ addr < CONTROL_STACK_GUARD_PAGE(th) + os_vm_page_size) {
+ /* We hit the end of the control stack: disable guard page
+ * protection so the error handler has some headroom, protect the
+ * previous page so that we can catch returns from the guard page
+ * and restore it. */
+ protect_control_stack_guard_page(th->pid,0);
+ protect_control_stack_return_guard_page(th->pid,1);
+
+ arrange_return_to_lisp_function
+ (context, SymbolFunction(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. */
+ protect_control_stack_guard_page(th->pid,1);
+ protect_control_stack_return_guard_page(th->pid,0);
+ 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));
+ return 1;
+ }
+ else return 0;
+}
+
+#ifndef LISP_FEATURE_GENCGC
+/* This function gets called from the SIGSEGV (for e.g. Linux, NetBSD, &
* OpenBSD) or SIGBUS (for e.g. FreeBSD) handler. Here we check
* whether the signal was due to treading on the mprotect()ed zone -
* and if so, arrange for a GC to happen. */
+extern unsigned long bytes_consed_between_gcs; /* gc-common.c */
+
boolean
interrupt_maybe_gc(int signal, siginfo_t *info, void *void_context)
{
os_context_t *context=(os_context_t *) void_context;
+ struct thread *th=arch_os_get_current_thread();
+ struct interrupt_data *data=
+ th ? th->interrupt_data : global_interrupt_data;
- if (!foreign_function_call_active
-#ifndef INTERNAL_GC_TRIGGER
- && gc_trigger_hit(signal, info, context)
-#endif
- ) {
-#ifndef INTERNAL_GC_TRIGGER
+ if(!foreign_function_call_active && gc_trigger_hit(signal, info, context)){
clear_auto_gc_trigger();
-#endif
-
- if (arch_pseudo_atomic_atomic(context)) {
- /* don't GC during an atomic operation. Instead, copy the
- * signal mask somewhere safe. interrupt_handle_pending
- * will detect pending_signal==0 and know to do a GC with the
- * signal context instead of calling a Lisp-level handler */
- maybe_gc_pending = 1;
- if (pending_signal == 0) {
- /* FIXME: This copy-pending_mask-then-sigaddset_blockable
- * idiom occurs over and over. It should be factored out
- * into a function with a descriptive name. */
- memcpy(&pending_mask,
- os_context_sigmask_addr(context),
- sizeof(sigset_t));
- sigaddset_blockable(os_context_sigmask_addr(context));
- }
- arch_set_pseudo_atomic_interrupted(context);
- }
- else {
- fake_foreign_function_call(context);
- funcall0(SymbolFunction(MAYBE_GC));
- undo_fake_foreign_function_call(context);
- }
-
+ if(!maybe_defer_handler
+ (interrupt_maybe_gc_int,data,signal,info,void_context))
+ interrupt_maybe_gc_int(signal,info,void_context);
return 1;
- } else {
- return 0;
}
+ return 0;
}
+
#endif
+
+/* this is also used by gencgc, in alloc() */
+boolean
+interrupt_maybe_gc_int(int signal, siginfo_t *info, void *void_context)
+{
+ sigset_t new;
+ os_context_t *context=(os_context_t *) void_context;
+ fake_foreign_function_call(context);
+ /* SUB-GC may return without GCing if *GC-INHIBIT* is set, in
+ * which case we will be running with no gc trigger barrier
+ * thing for a while. But it shouldn't be long until the end
+ * of WITHOUT-GCING. */
+
+ sigemptyset(&new);
+ sigaddset_blockable(&new);
+ /* enable signals before calling into Lisp */
+ sigprocmask(SIG_UNBLOCK,&new,0);
+ funcall0(SymbolFunction(SUB_GC));
+ undo_fake_foreign_function_call(context);
+ return 1;
+}
+
\f
/*
* noise to install handlers
*/
-/*
- * what low-level signal handlers looked like before
- * undoably_install_low_level_interrupt_handler() got involved
- */
-struct low_level_signal_handler_state {
- int was_modified;
- void (*handler)(int, siginfo_t*, void*);
-} old_low_level_signal_handler_states[NSIG];
-
-void
-uninstall_low_level_interrupt_handlers_atexit(void)
-{
- 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);
- }
- }
-}
-
-/* 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,
void*))
{
struct sigaction sa;
- struct low_level_signal_handler_state *old_low_level_signal_handler_state =
- old_low_level_signal_handler_states + signal;
+ struct thread *th=arch_os_get_current_thread();
+ struct interrupt_data *data=
+ th ? th->interrupt_data : global_interrupt_data;
if (0 > signal || signal >= NSIG) {
lose("bad signal number %d", signal);
sigemptyset(&sa.sa_mask);
sigaddset_blockable(&sa.sa_mask);
sa.sa_flags = SA_SIGINFO | SA_RESTART;
-
- /* In the case of interrupt handlers which are modified
- * more than once, we only save the original unmodified
- * copy. */
- if (!old_low_level_signal_handler_state->was_modified) {
- old_low_level_signal_handler_state->was_modified = 1;
- sigaction(signal, &sa, &old_low_level_signal_handler_state->handler);
- } else {
- sigaction(signal, &sa, NULL);
- }
-
- interrupt_low_level_handlers[signal] =
- (ARE_SAME_HANDLER(handler,SIG_DFL) ? 0 : handler);
+#ifdef LISP_FEATURE_C_STACK_IS_CONTROL_STACK
+ if((signal==SIG_MEMORY_FAULT)
+#ifdef SIG_INTERRUPT_THREAD
+ || (signal==SIG_INTERRUPT_THREAD)
+#endif
+ )
+ sa.sa_flags|= SA_ONSTACK;
+#endif
+
+ sigaction(signal, &sa, NULL);
+ data->interrupt_low_level_handlers[signal] =
+ (ARE_SAME_HANDLER(handler, SIG_DFL) ? 0 : handler);
}
/* This is called from Lisp. */
struct sigaction sa;
sigset_t old, new;
union interrupt_handler oldhandler;
+ struct thread *th=arch_os_get_current_thread();
+ struct interrupt_data *data=
+ th ? th->interrupt_data : global_interrupt_data;
FSHOW((stderr, "/entering POSIX install_handler(%d, ..)\n", signal));
sigemptyset(&new);
sigaddset_blockable(&new);
- FSHOW((stderr, "/interrupt_low_level_handlers[signal]=%d\n",
- interrupt_low_level_handlers[signal]));
- if (interrupt_low_level_handlers[signal]==0) {
+ FSHOW((stderr, "/data->interrupt_low_level_handlers[signal]=%d\n",
+ data->interrupt_low_level_handlers[signal]));
+ if (data->interrupt_low_level_handlers[signal]==0) {
if (ARE_SAME_HANDLER(handler, SIG_DFL) ||
ARE_SAME_HANDLER(handler, SIG_IGN)) {
sa.sa_sigaction = handler;
} else if (sigismember(&new, signal)) {
sa.sa_sigaction = maybe_now_maybe_later;
} else {
- sa.sa_sigaction = interrupt_handle_now;
+ 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);
}
- oldhandler = interrupt_handlers[signal];
- interrupt_handlers[signal].c = handler;
+ oldhandler = data->interrupt_handlers[signal];
+ data->interrupt_handlers[signal].c = handler;
sigprocmask(SIG_SETMASK, &old, 0);
}
void
-interrupt_init(void)
+interrupt_init()
{
int i;
-
SHOW("entering interrupt_init()");
-
- /* Set up for recovery from any installed low-level handlers. */
- atexit(&uninstall_low_level_interrupt_handlers_atexit);
+ global_interrupt_data=calloc(sizeof(struct interrupt_data), 1);
/* Set up high level handler information. */
for (i = 0; i < NSIG; i++) {
- interrupt_handlers[i].c =
+ global_interrupt_data->interrupt_handlers[i].c =
/* (The cast here blasts away the distinction between
* SA_SIGACTION-style three-argument handlers and
* signal(..)-style one-argument handlers, which is OK
projects / sbcl.git / blobdiff